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Diffstat (limited to 'gcc/ada/gnat_rm.texi')
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1 files changed, 17065 insertions, 11904 deletions
diff --git a/gcc/ada/gnat_rm.texi b/gcc/ada/gnat_rm.texi index b78bc51..bcf9b3c 100644 --- a/gcc/ada/gnat_rm.texi +++ b/gcc/ada/gnat_rm.texi @@ -1,751 +1,887 @@ \input texinfo @c -*-texinfo-*- - @c %**start of header - -@c oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo -@c o -@c GNAT DOCUMENTATION o -@c o -@c G N A T _ RM o -@c o -@c GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com). o -@c o -@c oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo - @setfilename gnat_rm.info +@documentencoding UTF-8 +@ifinfo +@*Generated by Sphinx 1.2.2.@* +@end ifinfo +@settitle GNAT Reference Manual +@defindex ge +@paragraphindent 0 +@exampleindent 4 +@finalout +@dircategory +@direntry +* gnat_rm: (gnat_rm.info). gnat_rm +@end direntry -@copying -Copyright @copyright{} 1995-2012, Free Software Foundation, Inc. - -Permission is granted to copy, distribute and/or modify this document -under the terms of the GNU Free Documentation License, Version 1.3 or -any later version published by the Free Software Foundation; with no -Invariant Sections, with the Front-Cover Texts being ``GNAT Reference -Manual'', and with no Back-Cover Texts. A copy of the license is -included in the section entitled ``GNU Free Documentation License''. -@end copying - -@set EDITION GNAT +@definfoenclose strong,`,' +@definfoenclose emph,`,' +@c %**end of header -@settitle GNAT Reference Manual +@copying +@quotation +GNAT Reference Manual , February 20, 2015 -@setchapternewpage odd -@syncodeindex fn cp +AdaCore -@include gcc-common.texi +Copyright @copyright{} 2008-2015, Free Software Foundation +@end quotation -@dircategory GNU Ada tools -@direntry -* GNAT Reference Manual: (gnat_rm). Reference Manual for GNU Ada tools. -@end direntry +@end copying @titlepage @title GNAT Reference Manual -@subtitle GNAT, The GNU Ada Development Environment -@versionsubtitle -@author AdaCore -@page -@vskip 0pt plus 1filll - @insertcopying - @end titlepage +@contents + +@c %** start of user preamble + +@c %** end of user preamble @ifnottex -@node Top, About This Guide, (dir), (dir) +@node Top @top GNAT Reference Manual +@insertcopying +@end ifnottex -@noindent -GNAT Reference Manual +@c %**start of body +@anchor{gnat_rm doc}@anchor{0} +@emph{GNAT, The GNU Ada Development Environment} -@noindent -GNAT, The GNU Ada Development Environment@* -GCC version @value{version-GCC}@* -@noindent +@include gcc-common.texi +GCC version @value{version-GCC}@* AdaCore +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with no +Invariant Sections, with the Front-Cover Texts being "GNAT Reference +Manual", and with no Back-Cover Texts. A copy of the license is +included in the section entitled @ref{1,,GNU Free Documentation License}. + @menu -* About This Guide:: -* Implementation Defined Pragmas:: -* Implementation Defined Aspects:: -* Implementation Defined Attributes:: -* Standard and Implementation Defined Restrictions:: -* Implementation Advice:: -* Implementation Defined Characteristics:: -* Intrinsic Subprograms:: -* Representation Clauses and Pragmas:: -* Standard Library Routines:: -* The Implementation of Standard I/O:: -* The GNAT Library:: -* Interfacing to Other Languages:: -* Specialized Needs Annexes:: -* Implementation of Specific Ada Features:: -* Implementation of Ada 2012 Features:: -* Obsolescent Features:: -* GNU Free Documentation License:: -* Index:Concept Index. +* About This Guide:: +* Implementation Defined Pragmas:: +* Implementation Defined Aspects:: +* Implementation Defined Attributes:: +* Standard and Implementation Defined Restrictions:: +* Implementation Advice:: +* Implementation Defined Characteristics:: +* Intrinsic Subprograms:: +* Representation Clauses and Pragmas:: +* Standard Library Routines:: +* The Implementation of Standard I/O:: +* The GNAT Library:: +* Interfacing to Other Languages:: +* Specialized Needs Annexes:: +* Implementation of Specific Ada Features:: +* Implementation of Ada 2012 Features:: +* Obsolescent Features:: +* Compatibility and Porting Guide:: +* GNU Free Documentation License:: +* Index:: @detailmenu --- The Detailed Node Listing --- About This Guide -* What This Reference Manual Contains:: -* Related Information:: +* What This Reference Manual Contains:: +* Conventions:: +* Related Information:: Implementation Defined Pragmas -* Pragma Abort_Defer:: -* Pragma Abstract_State:: -* Pragma Ada_83:: -* Pragma Ada_95:: -* Pragma Ada_05:: -* Pragma Ada_2005:: -* Pragma Ada_12:: -* Pragma Ada_2012:: -* Pragma Allow_Integer_Address:: -* Pragma Annotate:: -* Pragma Assert:: -* Pragma Assert_And_Cut:: -* Pragma Assertion_Policy:: -* Pragma Assume:: -* Pragma Assume_No_Invalid_Values:: -* Pragma AST_Entry:: -* Pragma Async_Readers:: -* Pragma Async_Writers:: -* Pragma Attribute_Definition:: -* Pragma C_Pass_By_Copy:: -* Pragma Check:: -* Pragma Check_Float_Overflow:: -* Pragma Check_Name:: -* Pragma Check_Policy:: -* Pragma CIL_Constructor:: -* Pragma Comment:: -* Pragma Common_Object:: -* Pragma Compile_Time_Error:: -* Pragma Compile_Time_Warning:: -* Pragma Compiler_Unit:: -* Pragma Compiler_Unit_Warning:: -* Pragma Complete_Representation:: -* Pragma Complex_Representation:: -* Pragma Component_Alignment:: -* Pragma Contract_Cases:: -* Pragma Convention_Identifier:: -* Pragma CPP_Class:: -* Pragma CPP_Constructor:: -* Pragma CPP_Virtual:: -* Pragma CPP_Vtable:: -* Pragma CPU:: -* Pragma Debug:: -* Pragma Debug_Policy:: -* Pragma Default_Scalar_Storage_Order:: -* Pragma Default_Storage_Pool:: -* Pragma Depends:: -* Pragma Detect_Blocking:: -* Pragma Disable_Atomic_Synchronization:: -* Pragma Dispatching_Domain:: -* Pragma Effective_Reads:: -* Pragma Effective_Writes:: -* Pragma Elaboration_Checks:: -* Pragma Eliminate:: -* Pragma Enable_Atomic_Synchronization:: -* Pragma Export_Exception:: -* Pragma Export_Function:: -* Pragma Export_Object:: -* Pragma Export_Procedure:: -* Pragma Export_Value:: -* Pragma Export_Valued_Procedure:: -* Pragma Extend_System:: -* Pragma Extensions_Allowed:: -* Pragma External:: -* Pragma External_Name_Casing:: -* Pragma Fast_Math:: -* Pragma Favor_Top_Level:: -* Pragma Finalize_Storage_Only:: -* Pragma Float_Representation:: -* Pragma Global:: -* Pragma Ident:: -* Pragma Implementation_Defined:: -* Pragma Implemented:: -* Pragma Implicit_Packing:: -* Pragma Import_Exception:: -* Pragma Import_Function:: -* Pragma Import_Object:: -* Pragma Import_Procedure:: -* Pragma Import_Valued_Procedure:: -* Pragma Independent:: -* Pragma Independent_Components:: -* Pragma Initial_Condition:: -* Pragma Initialize_Scalars:: -* Pragma Initializes:: -* Pragma Inline_Always:: -* Pragma Inline_Generic:: -* Pragma Interface:: -* Pragma Interface_Name:: -* Pragma Interrupt_Handler:: -* Pragma Interrupt_State:: -* Pragma Invariant:: -* Pragma Java_Constructor:: -* Pragma Java_Interface:: -* Pragma Keep_Names:: -* Pragma License:: -* Pragma Link_With:: -* Pragma Linker_Alias:: -* Pragma Linker_Constructor:: -* Pragma Linker_Destructor:: -* Pragma Linker_Section:: -* Pragma Lock_Free:: -* Pragma Long_Float:: -* Pragma Loop_Invariant:: -* Pragma Loop_Optimize:: -* Pragma Loop_Variant:: -* Pragma Machine_Attribute:: -* Pragma Main:: -* Pragma Main_Storage:: -* Pragma No_Body:: -* Pragma No_Elaboration_Code_All:: -* Pragma No_Inline:: -* Pragma No_Return:: -* Pragma No_Run_Time:: -* Pragma No_Strict_Aliasing :: -* Pragma No_Tagged_Streams:: -* Pragma Normalize_Scalars:: -* Pragma Obsolescent:: -* Pragma Optimize_Alignment:: -* Pragma Ordered:: -* Pragma Overflow_Mode:: -* Pragma Overriding_Renamings:: -* Pragma Partition_Elaboration_Policy:: -* Pragma Part_Of:: -* Pragma Passive:: -* Pragma Persistent_BSS:: -* Pragma Polling:: -* Pragma Post:: -* Pragma Postcondition:: -* Pragma Post_Class:: -* Pragma Pre:: -* Pragma Precondition:: -* Pragma Predicate:: -* Pragma Preelaborable_Initialization:: -* Pragma Prefix_Exception_Messages:: -* Pragma Pre_Class:: -* Pragma Priority_Specific_Dispatching:: -* Pragma Profile:: -* Pragma Profile_Warnings:: -* Pragma Propagate_Exceptions:: -* Pragma Provide_Shift_Operators:: -* Pragma Psect_Object:: -* Pragma Pure_Function:: -* Pragma Rational:: -* Pragma Ravenscar:: -* Pragma Refined_Depends:: -* Pragma Refined_Global:: -* Pragma Refined_Post:: -* Pragma Refined_State:: -* Pragma Relative_Deadline:: -* Pragma Remote_Access_Type:: -* Pragma Restricted_Run_Time:: -* Pragma Restriction_Warnings:: -* Pragma Reviewable:: -* Pragma Share_Generic:: -* Pragma Shared:: -* Pragma Short_Circuit_And_Or:: -* Pragma Short_Descriptors:: -* Pragma Simple_Storage_Pool_Type:: -* Pragma Source_File_Name:: -* Pragma Source_File_Name_Project:: -* Pragma Source_Reference:: -* Pragma SPARK_Mode:: -* Pragma Static_Elaboration_Desired:: -* Pragma Stream_Convert:: -* Pragma Style_Checks:: -* Pragma Subtitle:: -* Pragma Suppress:: -* Pragma Suppress_All:: -* Pragma Suppress_Debug_Info:: -* Pragma Suppress_Exception_Locations:: -* Pragma Suppress_Initialization:: -* Pragma Task_Name:: -* Pragma Task_Storage:: -* Pragma Test_Case:: -* Pragma Thread_Local_Storage:: -* Pragma Time_Slice:: -* Pragma Title:: -* Pragma Type_Invariant:: -* Pragma Type_Invariant_Class:: -* Pragma Unchecked_Union:: -* Pragma Unevaluated_Use_Of_Old:: -* Pragma Unimplemented_Unit:: -* Pragma Universal_Aliasing :: -* Pragma Universal_Data:: -* Pragma Unmodified:: -* Pragma Unreferenced:: -* Pragma Unreferenced_Objects:: -* Pragma Unreserve_All_Interrupts:: -* Pragma Unsuppress:: -* Pragma Use_VADS_Size:: -* Pragma Validity_Checks:: -* Pragma Volatile:: -* Pragma Warning_As_Error:: -* Pragma Warnings:: -* Pragma Weak_External:: -* Pragma Wide_Character_Encoding:: +* Pragma Abort_Defer:: +* Pragma Abstract_State:: +* Pragma Ada_83:: +* Pragma Ada_95:: +* Pragma Ada_05:: +* Pragma Ada_2005:: +* Pragma Ada_12:: +* Pragma Ada_2012:: +* Pragma Allow_Integer_Address:: +* Pragma Annotate:: +* Pragma Assert:: +* Pragma Assert_And_Cut:: +* Pragma Assertion_Policy:: +* Pragma Assume:: +* Pragma Assume_No_Invalid_Values:: +* Pragma Async_Readers:: +* Pragma Async_Writers:: +* Pragma Attribute_Definition:: +* Pragma C_Pass_By_Copy:: +* Pragma Check:: +* Pragma Check_Float_Overflow:: +* Pragma Check_Name:: +* Pragma Check_Policy:: +* Pragma CIL_Constructor:: +* Pragma Comment:: +* Pragma Common_Object:: +* Pragma Compile_Time_Error:: +* Pragma Compile_Time_Warning:: +* Pragma Compiler_Unit:: +* Pragma Compiler_Unit_Warning:: +* Pragma Complete_Representation:: +* Pragma Complex_Representation:: +* Pragma Component_Alignment:: +* Pragma Contract_Cases:: +* Pragma Convention_Identifier:: +* Pragma CPP_Class:: +* Pragma CPP_Constructor:: +* Pragma CPP_Virtual:: +* Pragma CPP_Vtable:: +* Pragma CPU:: +* Pragma Debug:: +* Pragma Debug_Policy:: +* Pragma Default_Scalar_Storage_Order:: +* Pragma Default_Storage_Pool:: +* Pragma Depends:: +* Pragma Detect_Blocking:: +* Pragma Disable_Atomic_Synchronization:: +* Pragma Dispatching_Domain:: +* Pragma Effective_Reads:: +* Pragma Effective_Writes:: +* Pragma Elaboration_Checks:: +* Pragma Eliminate:: +* Pragma Enable_Atomic_Synchronization:: +* Pragma Export_Function:: +* Pragma Export_Object:: +* Pragma Export_Procedure:: +* Pragma Export_Value:: +* Pragma Export_Valued_Procedure:: +* Pragma Extend_System:: +* Pragma Extensions_Allowed:: +* Pragma External:: +* Pragma External_Name_Casing:: +* Pragma Fast_Math:: +* Pragma Favor_Top_Level:: +* Pragma Finalize_Storage_Only:: +* Pragma Float_Representation:: +* Pragma Global:: +* Pragma Ident:: +* Pragma Implementation_Defined:: +* Pragma Implemented:: +* Pragma Implicit_Packing:: +* Pragma Import_Function:: +* Pragma Import_Object:: +* Pragma Import_Procedure:: +* Pragma Import_Valued_Procedure:: +* Pragma Independent:: +* Pragma Independent_Components:: +* Pragma Initial_Condition:: +* Pragma Initialize_Scalars:: +* Pragma Initializes:: +* Pragma Inline_Always:: +* Pragma Inline_Generic:: +* Pragma Interface:: +* Pragma Interface_Name:: +* Pragma Interrupt_Handler:: +* Pragma Interrupt_State:: +* Pragma Invariant:: +* Pragma Java_Constructor:: +* Pragma Java_Interface:: +* Pragma Keep_Names:: +* Pragma License:: +* Pragma Link_With:: +* Pragma Linker_Alias:: +* Pragma Linker_Constructor:: +* Pragma Linker_Destructor:: +* Pragma Linker_Section:: +* Pragma Lock_Free:: +* Pragma Loop_Invariant:: +* Pragma Loop_Optimize:: +* Pragma Loop_Variant:: +* Pragma Machine_Attribute:: +* Pragma Main:: +* Pragma Main_Storage:: +* Pragma No_Body:: +* Pragma No_Elaboration_Code_All:: +* Pragma No_Inline:: +* Pragma No_Return:: +* Pragma No_Run_Time:: +* Pragma No_Strict_Aliasing:: +* Pragma No_Tagged_Streams:: +* Pragma Normalize_Scalars:: +* Pragma Obsolescent:: +* Pragma Optimize_Alignment:: +* Pragma Ordered:: +* Pragma Overflow_Mode:: +* Pragma Overriding_Renamings:: +* Pragma Partition_Elaboration_Policy:: +* Pragma Part_Of:: +* Pragma Passive:: +* Pragma Persistent_BSS:: +* Pragma Polling:: +* Pragma Post:: +* Pragma Postcondition:: +* Pragma Post_Class:: +* Pragma Pre:: +* Pragma Precondition:: +* Pragma Predicate:: +* Pragma Preelaborable_Initialization:: +* Pragma Prefix_Exception_Messages:: +* Pragma Pre_Class:: +* Pragma Priority_Specific_Dispatching:: +* Pragma Profile:: +* Pragma Profile_Warnings:: +* Pragma Propagate_Exceptions:: +* Pragma Provide_Shift_Operators:: +* Pragma Psect_Object:: +* Pragma Pure_Function:: +* Pragma Rational:: +* Pragma Ravenscar:: +* Pragma Refined_Depends:: +* Pragma Refined_Global:: +* Pragma Refined_Post:: +* Pragma Refined_State:: +* Pragma Relative_Deadline:: +* Pragma Remote_Access_Type:: +* Pragma Restricted_Run_Time:: +* Pragma Restriction_Warnings:: +* Pragma Reviewable:: +* Pragma Share_Generic:: +* Pragma Shared:: +* Pragma Short_Circuit_And_Or:: +* Pragma Short_Descriptors:: +* Pragma Simple_Storage_Pool_Type:: +* Pragma Source_File_Name:: +* Pragma Source_File_Name_Project:: +* Pragma Source_Reference:: +* Pragma SPARK_Mode:: +* Pragma Static_Elaboration_Desired:: +* Pragma Stream_Convert:: +* Pragma Style_Checks:: +* Pragma Subtitle:: +* Pragma Suppress:: +* Pragma Suppress_All:: +* Pragma Suppress_Debug_Info:: +* Pragma Suppress_Exception_Locations:: +* Pragma Suppress_Initialization:: +* Pragma Task_Name:: +* Pragma Task_Storage:: +* Pragma Test_Case:: +* Pragma Thread_Local_Storage:: +* Pragma Time_Slice:: +* Pragma Title:: +* Pragma Type_Invariant:: +* Pragma Type_Invariant_Class:: +* Pragma Unchecked_Union:: +* Pragma Unevaluated_Use_Of_Old:: +* Pragma Unimplemented_Unit:: +* Pragma Universal_Aliasing:: +* Pragma Universal_Data:: +* Pragma Unmodified:: +* Pragma Unreferenced:: +* Pragma Unreferenced_Objects:: +* Pragma Unreserve_All_Interrupts:: +* Pragma Unsuppress:: +* Pragma Use_VADS_Size:: +* Pragma Validity_Checks:: +* Pragma Volatile:: +* Pragma Warning_As_Error:: +* Pragma Warnings:: +* Pragma Weak_External:: +* Pragma Wide_Character_Encoding:: Implementation Defined Aspects -* Aspect Abstract_State:: -* Aspect Annotate:: -* Aspect Async_Readers:: -* Aspect Async_Writers:: -* Aspect Contract_Cases:: -* Aspect Depends:: -* Aspect Dimension:: -* Aspect Dimension_System:: -* Aspect Effective_Reads:: -* Aspect Effective_Writes:: -* Aspect Favor_Top_Level:: -* Aspect Global:: -* Aspect Initial_Condition:: -* Aspect Initializes:: -* Aspect Inline_Always:: -* Aspect Invariant:: -* Aspect Invariant'Class:: -* Aspect Iterable:: -* Aspect Linker_Section:: -* Aspect No_Elaboration_Code_All:: -* Aspect No_Tagged_Streams:: -* Aspect Object_Size:: -* Aspect Obsolescent:: -* Aspect Part_Of:: -* Aspect Persistent_BSS:: -* Aspect Predicate:: -* Aspect Pure_Function:: -* Aspect Refined_Depends:: -* Aspect Refined_Global:: -* Aspect Refined_Post:: -* Aspect Refined_State:: -* Aspect Remote_Access_Type:: -* Aspect Scalar_Storage_Order:: -* Aspect Shared:: -* Aspect Simple_Storage_Pool:: -* Aspect Simple_Storage_Pool_Type:: -* Aspect SPARK_Mode:: -* Aspect Suppress_Debug_Info:: -* Aspect Suppress_Initialization:: -* Aspect Test_Case:: -* Aspect Thread_Local_Storage:: -* Aspect Universal_Aliasing:: -* Aspect Universal_Data:: -* Aspect Unmodified:: -* Aspect Unreferenced:: -* Aspect Unreferenced_Objects:: -* Aspect Value_Size:: -* Aspect Warnings:: +* Aspect Abstract_State:: +* Annotate:: +* Aspect Async_Readers:: +* Aspect Async_Writers:: +* Aspect Contract_Cases:: +* Aspect Depends:: +* Aspect Dimension:: +* Aspect Dimension_System:: +* Aspect Effective_Reads:: +* Aspect Effective_Writes:: +* Aspect Favor_Top_Level:: +* Aspect Global:: +* Aspect Initial_Condition:: +* Aspect Initializes:: +* Aspect Inline_Always:: +* Aspect Invariant:: +* Aspect Invariant'Class:: +* Aspect Iterable:: +* Aspect Linker_Section:: +* Aspect Lock_Free:: +* Aspect No_Elaboration_Code_All:: +* Aspect No_Tagged_Streams:: +* Aspect Object_Size:: +* Aspect Obsolescent:: +* Aspect Part_Of:: +* Aspect Persistent_BSS:: +* Aspect Predicate:: +* Aspect Pure_Function:: +* Aspect Refined_Depends:: +* Aspect Refined_Global:: +* Aspect Refined_Post:: +* Aspect Refined_State:: +* Aspect Remote_Access_Type:: +* Aspect Scalar_Storage_Order:: +* Aspect Shared:: +* Aspect Simple_Storage_Pool:: +* Aspect Simple_Storage_Pool_Type:: +* Aspect SPARK_Mode:: +* Aspect Suppress_Debug_Info:: +* Aspect Suppress_Initialization:: +* Aspect Test_Case:: +* Aspect Thread_Local_Storage:: +* Aspect Universal_Aliasing:: +* Aspect Universal_Data:: +* Aspect Unmodified:: +* Aspect Unreferenced:: +* Aspect Unreferenced_Objects:: +* Aspect Value_Size:: +* Aspect Warnings:: Implementation Defined Attributes -* Attribute Abort_Signal:: -* Attribute Address_Size:: -* Attribute Asm_Input:: -* Attribute Asm_Output:: -* Attribute AST_Entry:: -* Attribute Atomic_Always_Lock_Free:: -* Attribute Bit:: -* Attribute Bit_Position:: -* Attribute Code_Address:: -* Attribute Compiler_Version:: -* Attribute Constrained:: -* Attribute Default_Bit_Order:: -* Attribute Default_Scalar_Storage_Order:: -* Attribute Descriptor_Size:: -* Attribute Elaborated:: -* Attribute Elab_Body:: -* Attribute Elab_Spec:: -* Attribute Elab_Subp_Body:: -* Attribute Emax:: -* Attribute Enabled:: -* Attribute Enum_Rep:: -* Attribute Enum_Val:: -* Attribute Epsilon:: -* Attribute Fast_Math:: -* Attribute Fixed_Value:: -* Attribute From_Any:: -* Attribute Has_Access_Values:: -* Attribute Has_Discriminants:: -* Attribute Img:: -* Attribute Integer_Value:: -* Attribute Invalid_Value:: -* Attribute Iterable:: -* Attribute Large:: -* Attribute Library_Level:: -* Attribute Lock_Free:: -* Attribute Loop_Entry:: -* Attribute Machine_Size:: -* Attribute Mantissa:: -* Attribute Maximum_Alignment:: -* Attribute Mechanism_Code:: -* Attribute Null_Parameter:: -* Attribute Object_Size:: -* Attribute Old:: -* Attribute Passed_By_Reference:: -* Attribute Pool_Address:: -* Attribute Range_Length:: -* Attribute Ref:: -* Attribute Restriction_Set:: -* Attribute Result:: -* Attribute Safe_Emax:: -* Attribute Safe_Large:: -* Attribute Safe_Small:: -* Attribute Scalar_Storage_Order:: -* Attribute Simple_Storage_Pool:: -* Attribute Small:: -* Attribute Storage_Unit:: -* Attribute Stub_Type:: -* Attribute System_Allocator_Alignment:: -* Attribute Target_Name:: -* Attribute To_Address:: -* Attribute To_Any:: -* Attribute Type_Class:: -* Attribute Type_Key:: -* Attribute TypeCode:: -* Attribute UET_Address:: -* Attribute Unconstrained_Array:: -* Attribute Universal_Literal_String:: -* Attribute Unrestricted_Access:: -* Attribute Update:: -* Attribute VADS_Size:: -* Attribute Valid_Scalars:: -* Attribute Value_Size:: -* Attribute Wchar_T_Size:: -* Attribute Word_Size:: +* Attribute Abort_Signal:: +* Attribute Address_Size:: +* Attribute Asm_Input:: +* Attribute Asm_Output:: +* Attribute Atomic_Always_Lock_Free:: +* Attribute Bit:: +* Attribute Bit_Position:: +* Attribute Code_Address:: +* Attribute Compiler_Version:: +* Attribute Constrained:: +* Attribute Default_Bit_Order:: +* Attribute Default_Scalar_Storage_Order:: +* Attribute Descriptor_Size:: +* Attribute Elaborated:: +* Attribute Elab_Body:: +* Attribute Elab_Spec:: +* Attribute Elab_Subp_Body:: +* Attribute Emax:: +* Attribute Enabled:: +* Attribute Enum_Rep:: +* Attribute Enum_Val:: +* Attribute Epsilon:: +* Attribute Fast_Math:: +* Attribute Fixed_Value:: +* Attribute From_Any:: +* Attribute Has_Access_Values:: +* Attribute Has_Discriminants:: +* Attribute Img:: +* Attribute Integer_Value:: +* Attribute Invalid_Value:: +* Attribute Iterable:: +* Attribute Large:: +* Attribute Library_Level:: +* Attribute Lock_Free:: +* Attribute Loop_Entry:: +* Attribute Machine_Size:: +* Attribute Mantissa:: +* Attribute Maximum_Alignment:: +* Attribute Mechanism_Code:: +* Attribute Null_Parameter:: +* Attribute Object_Size:: +* Attribute Old:: +* Attribute Passed_By_Reference:: +* Attribute Pool_Address:: +* Attribute Range_Length:: +* Attribute Ref:: +* Attribute Restriction_Set:: +* Attribute Result:: +* Attribute Safe_Emax:: +* Attribute Safe_Large:: +* Attribute Safe_Small:: +* Attribute Scalar_Storage_Order:: +* Attribute Simple_Storage_Pool:: +* Attribute Small:: +* Attribute Storage_Unit:: +* Attribute Stub_Type:: +* Attribute System_Allocator_Alignment:: +* Attribute Target_Name:: +* Attribute To_Address:: +* Attribute To_Any:: +* Attribute Type_Class:: +* Attribute Type_Key:: +* Attribute TypeCode:: +* Attribute UET_Address:: +* Attribute Unconstrained_Array:: +* Attribute Universal_Literal_String:: +* Attribute Unrestricted_Access:: +* Attribute Update:: +* Attribute Valid_Scalars:: +* Attribute VADS_Size:: +* Attribute Value_Size:: +* Attribute Wchar_T_Size:: +* Attribute Word_Size:: Standard and Implementation Defined Restrictions -* Partition-Wide Restrictions:: -* Program Unit Level Restrictions:: +* Partition-Wide Restrictions:: +* Program Unit Level Restrictions:: Partition-Wide Restrictions -* Immediate_Reclamation:: -* Max_Asynchronous_Select_Nesting:: -* Max_Entry_Queue_Length:: -* Max_Protected_Entries:: -* Max_Select_Alternatives:: -* Max_Storage_At_Blocking:: -* Max_Task_Entries:: -* Max_Tasks:: -* No_Abort_Statements:: -* No_Access_Parameter_Allocators:: -* No_Access_Subprograms:: -* No_Allocators:: -* No_Anonymous_Allocators:: -* No_Calendar:: -* No_Coextensions:: -* No_Default_Initialization:: -* No_Delay:: -* No_Dependence:: -* No_Direct_Boolean_Operators:: -* No_Dispatch:: -* No_Dispatching_Calls:: -* No_Dynamic_Attachment:: -* No_Dynamic_Priorities:: -* No_Entry_Calls_In_Elaboration_Code:: -* No_Enumeration_Maps:: -* No_Exception_Handlers:: -* No_Exception_Propagation:: -* No_Exception_Registration:: -* No_Exceptions:: -* No_Finalization:: -* No_Fixed_Point:: -* No_Floating_Point:: -* No_Implicit_Conditionals:: -* No_Implicit_Dynamic_Code:: -* No_Implicit_Heap_Allocations:: -* No_Implicit_Loops:: -* No_Initialize_Scalars:: -* No_IO:: -* No_Local_Allocators:: -* No_Local_Protected_Objects:: -* No_Local_Timing_Events:: -* No_Long_Long_Integers:: -* No_Multiple_Elaboration:: -* No_Nested_Finalization:: -* No_Protected_Type_Allocators:: -* No_Protected_Types:: -* No_Recursion:: -* No_Reentrancy:: -* No_Relative_Delay:: -* No_Requeue_Statements:: -* No_Secondary_Stack:: -* No_Select_Statements:: -* No_Specific_Termination_Handlers:: -* No_Specification_of_Aspect:: -* No_Standard_Allocators_After_Elaboration:: -* No_Standard_Storage_Pools:: -* No_Stream_Optimizations:: -* No_Streams:: -* No_Task_Allocators:: -* No_Task_Attributes_Package:: -* No_Task_Hierarchy:: -* No_Task_Termination:: -* No_Tasking:: -* No_Terminate_Alternatives:: -* No_Unchecked_Access:: -* Simple_Barriers:: -* Static_Priorities:: -* Static_Storage_Size:: +* Immediate_Reclamation:: +* Max_Asynchronous_Select_Nesting:: +* Max_Entry_Queue_Length:: +* Max_Protected_Entries:: +* Max_Select_Alternatives:: +* Max_Storage_At_Blocking:: +* Max_Task_Entries:: +* Max_Tasks:: +* No_Abort_Statements:: +* No_Access_Parameter_Allocators:: +* No_Access_Subprograms:: +* No_Allocators:: +* No_Anonymous_Allocators:: +* No_Calendar:: +* No_Coextensions:: +* No_Default_Initialization:: +* No_Delay:: +* No_Dependence:: +* No_Direct_Boolean_Operators:: +* No_Dispatch:: +* No_Dispatching_Calls:: +* No_Dynamic_Attachment:: +* No_Dynamic_Priorities:: +* No_Entry_Calls_In_Elaboration_Code:: +* No_Enumeration_Maps:: +* No_Exception_Handlers:: +* No_Exception_Propagation:: +* No_Exception_Registration:: +* No_Exceptions:: +* No_Finalization:: +* No_Fixed_Point:: +* No_Floating_Point:: +* No_Implicit_Conditionals:: +* No_Implicit_Dynamic_Code:: +* No_Implicit_Heap_Allocations:: +* No_Implicit_Loops:: +* No_Initialize_Scalars:: +* No_IO:: +* No_Local_Allocators:: +* No_Local_Protected_Objects:: +* No_Local_Timing_Events:: +* No_Long_Long_Integers:: +* No_Multiple_Elaboration:: +* No_Nested_Finalization:: +* No_Protected_Type_Allocators:: +* No_Protected_Types:: +* No_Recursion:: +* No_Reentrancy:: +* No_Relative_Delay:: +* No_Requeue_Statements:: +* No_Secondary_Stack:: +* No_Select_Statements:: +* No_Specific_Termination_Handlers:: +* No_Specification_of_Aspect:: +* No_Standard_Allocators_After_Elaboration:: +* No_Standard_Storage_Pools:: +* No_Stream_Optimizations:: +* No_Streams:: +* No_Task_Allocators:: +* No_Task_Attributes_Package:: +* No_Task_Hierarchy:: +* No_Task_Termination:: +* No_Tasking:: +* No_Terminate_Alternatives:: +* No_Unchecked_Access:: +* No_Use_Of_Entity:: +* Simple_Barriers:: +* Static_Priorities:: +* Static_Storage_Size:: Program Unit Level Restrictions -* No_Elaboration_Code:: -* No_Entry_Queue:: -* No_Implementation_Aspect_Specifications:: -* No_Implementation_Attributes:: -* No_Implementation_Identifiers:: -* No_Implementation_Pragmas:: -* No_Implementation_Restrictions:: -* No_Implementation_Units:: -* No_Implicit_Aliasing:: -* No_Obsolescent_Features:: -* No_Wide_Characters:: -* SPARK_05:: +* No_Elaboration_Code:: +* No_Entry_Queue:: +* No_Implementation_Aspect_Specifications:: +* No_Implementation_Attributes:: +* No_Implementation_Identifiers:: +* No_Implementation_Pragmas:: +* No_Implementation_Restrictions:: +* No_Implementation_Units:: +* No_Implicit_Aliasing:: +* No_Obsolescent_Features:: +* No_Wide_Characters:: +* SPARK_05:: + +Implementation Advice + +* RM 1.1.3(20); Error Detection: RM 1 1 3 20 Error Detection. +* RM 1.1.3(31); Child Units: RM 1 1 3 31 Child Units. +* RM 1.1.5(12); Bounded Errors: RM 1 1 5 12 Bounded Errors. +* RM 2.8(16); Pragmas: RM 2 8 16 Pragmas. +* RM 2.8(17-19); Pragmas: RM 2 8 17-19 Pragmas. +* RM 3.5.2(5); Alternative Character Sets: RM 3 5 2 5 Alternative Character Sets. +* RM 3.5.4(28); Integer Types: RM 3 5 4 28 Integer Types. +* RM 3.5.4(29); Integer Types: RM 3 5 4 29 Integer Types. +* RM 3.5.5(8); Enumeration Values: RM 3 5 5 8 Enumeration Values. +* RM 3.5.7(17); Float Types: RM 3 5 7 17 Float Types. +* RM 3.6.2(11); Multidimensional Arrays: RM 3 6 2 11 Multidimensional Arrays. +* RM 9.6(30-31); Duration'Small: RM 9 6 30-31 Duration'Small. +* RM 10.2.1(12); Consistent Representation: RM 10 2 1 12 Consistent Representation. +* RM 11.4.1(19); Exception Information: RM 11 4 1 19 Exception Information. +* RM 11.5(28); Suppression of Checks: RM 11 5 28 Suppression of Checks. +* RM 13.1 (21-24); Representation Clauses: RM 13 1 21-24 Representation Clauses. +* RM 13.2(6-8); Packed Types: RM 13 2 6-8 Packed Types. +* RM 13.3(14-19); Address Clauses: RM 13 3 14-19 Address Clauses. +* RM 13.3(29-35); Alignment Clauses: RM 13 3 29-35 Alignment Clauses. +* RM 13.3(42-43); Size Clauses: RM 13 3 42-43 Size Clauses. +* RM 13.3(50-56); Size Clauses: RM 13 3 50-56 Size Clauses. +* RM 13.3(71-73); Component Size Clauses: RM 13 3 71-73 Component Size Clauses. +* RM 13.4(9-10); Enumeration Representation Clauses: RM 13 4 9-10 Enumeration Representation Clauses. +* RM 13.5.1(17-22); Record Representation Clauses: RM 13 5 1 17-22 Record Representation Clauses. +* RM 13.5.2(5); Storage Place Attributes: RM 13 5 2 5 Storage Place Attributes. +* RM 13.5.3(7-8); Bit Ordering: RM 13 5 3 7-8 Bit Ordering. +* RM 13.7(37); Address as Private: RM 13 7 37 Address as Private. +* RM 13.7.1(16); Address Operations: RM 13 7 1 16 Address Operations. +* RM 13.9(14-17); Unchecked Conversion: RM 13 9 14-17 Unchecked Conversion. +* RM 13.11(23-25); Implicit Heap Usage: RM 13 11 23-25 Implicit Heap Usage. +* RM 13.11.2(17); Unchecked Deallocation: RM 13 11 2 17 Unchecked Deallocation. +* RM 13.13.2(17); Stream Oriented Attributes: RM 13 13 2 17 Stream Oriented Attributes. +* RM A.1(52); Names of Predefined Numeric Types: RM A 1 52 Names of Predefined Numeric Types. +* RM A.3.2(49); Ada.Characters.Handling: RM A 3 2 49 Ada Characters Handling. +* RM A.4.4(106); Bounded-Length String Handling: RM A 4 4 106 Bounded-Length String Handling. +* RM A.5.2(46-47); Random Number Generation: RM A 5 2 46-47 Random Number Generation. +* RM A.10.7(23); Get_Immediate: RM A 10 7 23 Get_Immediate. +* RM B.1(39-41); Pragma Export: RM B 1 39-41 Pragma Export. +* RM B.2(12-13); Package Interfaces: RM B 2 12-13 Package Interfaces. +* RM B.3(63-71); Interfacing with C: RM B 3 63-71 Interfacing with C. +* RM B.4(95-98); Interfacing with COBOL: RM B 4 95-98 Interfacing with COBOL. +* RM B.5(22-26); Interfacing with Fortran: RM B 5 22-26 Interfacing with Fortran. +* RM C.1(3-5); Access to Machine Operations: RM C 1 3-5 Access to Machine Operations. +* RM C.1(10-16); Access to Machine Operations: RM C 1 10-16 Access to Machine Operations. +* RM C.3(28); Interrupt Support: RM C 3 28 Interrupt Support. +* RM C.3.1(20-21); Protected Procedure Handlers: RM C 3 1 20-21 Protected Procedure Handlers. +* RM C.3.2(25); Package Interrupts: RM C 3 2 25 Package Interrupts. +* RM C.4(14); Pre-elaboration Requirements: RM C 4 14 Pre-elaboration Requirements. +* RM C.5(8); Pragma Discard_Names: RM C 5 8 Pragma Discard_Names. +* RM C.7.2(30); The Package Task_Attributes: RM C 7 2 30 The Package Task_Attributes. +* RM D.3(17); Locking Policies: RM D 3 17 Locking Policies. +* RM D.4(16); Entry Queuing Policies: RM D 4 16 Entry Queuing Policies. +* RM D.6(9-10); Preemptive Abort: RM D 6 9-10 Preemptive Abort. +* RM D.7(21); Tasking Restrictions: RM D 7 21 Tasking Restrictions. +* RM D.8(47-49); Monotonic Time: RM D 8 47-49 Monotonic Time. +* RM E.5(28-29); Partition Communication Subsystem: RM E 5 28-29 Partition Communication Subsystem. +* RM F(7); COBOL Support: RM F 7 COBOL Support. +* RM F.1(2); Decimal Radix Support: RM F 1 2 Decimal Radix Support. +* RM G; Numerics: RM G Numerics. +* RM G.1.1(56-58); Complex Types: RM G 1 1 56-58 Complex Types. +* RM G.1.2(49); Complex Elementary Functions: RM G 1 2 49 Complex Elementary Functions. +* RM G.2.4(19); Accuracy Requirements: RM G 2 4 19 Accuracy Requirements. +* RM G.2.6(15); Complex Arithmetic Accuracy: RM G 2 6 15 Complex Arithmetic Accuracy. +* RM H.6(15/2); Pragma Partition_Elaboration_Policy: RM H 6 15/2 Pragma Partition_Elaboration_Policy. + +Intrinsic Subprograms + +* Intrinsic Operators:: +* Compilation_Date:: +* Compilation_Time:: +* Enclosing_Entity:: +* Exception_Information:: +* Exception_Message:: +* Exception_Name:: +* File:: +* Line:: +* Shifts and Rotates:: +* Source_Location:: + +Representation Clauses and Pragmas + +* Alignment Clauses:: +* Size Clauses:: +* Storage_Size Clauses:: +* Size of Variant Record Objects:: +* Biased Representation:: +* Value_Size and Object_Size Clauses:: +* Component_Size Clauses:: +* Bit_Order Clauses:: +* Effect of Bit_Order on Byte Ordering:: +* Pragma Pack for Arrays:: +* Pragma Pack for Records:: +* Record Representation Clauses:: +* Handling of Records with Holes:: +* Enumeration Clauses:: +* Address Clauses:: +* Use of Address Clauses for Memory-Mapped I/O:: +* Effect of Convention on Representation:: +* Conventions and Anonymous Access Types:: +* Determining the Representations chosen by GNAT:: The Implementation of Standard I/O -* Standard I/O Packages:: -* FORM Strings:: -* Direct_IO:: -* Sequential_IO:: -* Text_IO:: -* Wide_Text_IO:: -* Wide_Wide_Text_IO:: -* Stream_IO:: -* Text Translation:: -* Shared Files:: -* Filenames encoding:: -* File content encoding:: -* Open Modes:: -* Operations on C Streams:: -* Interfacing to C Streams:: - -The GNAT Library - -* Ada.Characters.Latin_9 (a-chlat9.ads):: -* Ada.Characters.Wide_Latin_1 (a-cwila1.ads):: -* Ada.Characters.Wide_Latin_9 (a-cwila9.ads):: -* Ada.Characters.Wide_Wide_Latin_1 (a-chzla1.ads):: -* Ada.Characters.Wide_Wide_Latin_9 (a-chzla9.ads):: -* Ada.Containers.Formal_Doubly_Linked_Lists (a-cfdlli.ads):: -* Ada.Containers.Formal_Hashed_Maps (a-cfhama.ads):: -* Ada.Containers.Formal_Hashed_Sets (a-cfhase.ads):: -* Ada.Containers.Formal_Ordered_Maps (a-cforma.ads):: -* Ada.Containers.Formal_Ordered_Sets (a-cforse.ads):: -* Ada.Containers.Formal_Vectors (a-cofove.ads):: -* Ada.Containers.Formal_Indefinite_Vectors (a-cfinve.ads):: -* Ada.Containers.Bounded_Holders (a-coboho.ads):: -* Ada.Command_Line.Environment (a-colien.ads):: -* Ada.Command_Line.Remove (a-colire.ads):: -* Ada.Command_Line.Response_File (a-clrefi.ads):: -* Ada.Direct_IO.C_Streams (a-diocst.ads):: -* Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads):: -* Ada.Exceptions.Last_Chance_Handler (a-elchha.ads):: -* Ada.Exceptions.Traceback (a-exctra.ads):: -* Ada.Sequential_IO.C_Streams (a-siocst.ads):: -* Ada.Streams.Stream_IO.C_Streams (a-ssicst.ads):: -* Ada.Strings.Unbounded.Text_IO (a-suteio.ads):: -* Ada.Strings.Wide_Unbounded.Wide_Text_IO (a-swuwti.ads):: -* Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO (a-szuzti.ads):: -* Ada.Text_IO.C_Streams (a-tiocst.ads):: -* Ada.Text_IO.Reset_Standard_Files (a-tirsfi.ads):: -* Ada.Wide_Characters.Unicode (a-wichun.ads):: -* Ada.Wide_Text_IO.C_Streams (a-wtcstr.ads):: -* Ada.Wide_Text_IO.Reset_Standard_Files (a-wrstfi.ads):: -* Ada.Wide_Wide_Characters.Unicode (a-zchuni.ads):: -* Ada.Wide_Wide_Text_IO.C_Streams (a-ztcstr.ads):: -* Ada.Wide_Wide_Text_IO.Reset_Standard_Files (a-zrstfi.ads):: -* GNAT.Altivec (g-altive.ads):: -* GNAT.Altivec.Conversions (g-altcon.ads):: -* GNAT.Altivec.Vector_Operations (g-alveop.ads):: -* GNAT.Altivec.Vector_Types (g-alvety.ads):: -* GNAT.Altivec.Vector_Views (g-alvevi.ads):: -* GNAT.Array_Split (g-arrspl.ads):: -* GNAT.AWK (g-awk.ads):: -* GNAT.Bounded_Buffers (g-boubuf.ads):: -* GNAT.Bounded_Mailboxes (g-boumai.ads):: -* GNAT.Bubble_Sort (g-bubsor.ads):: -* GNAT.Bubble_Sort_A (g-busora.ads):: -* GNAT.Bubble_Sort_G (g-busorg.ads):: -* GNAT.Byte_Order_Mark (g-byorma.ads):: -* GNAT.Byte_Swapping (g-bytswa.ads):: -* GNAT.Calendar (g-calend.ads):: -* GNAT.Calendar.Time_IO (g-catiio.ads):: -* GNAT.Case_Util (g-casuti.ads):: -* GNAT.CGI (g-cgi.ads):: -* GNAT.CGI.Cookie (g-cgicoo.ads):: -* GNAT.CGI.Debug (g-cgideb.ads):: -* GNAT.Command_Line (g-comlin.ads):: -* GNAT.Compiler_Version (g-comver.ads):: -* GNAT.Ctrl_C (g-ctrl_c.ads):: -* GNAT.CRC32 (g-crc32.ads):: -* GNAT.Current_Exception (g-curexc.ads):: -* GNAT.Debug_Pools (g-debpoo.ads):: -* GNAT.Debug_Utilities (g-debuti.ads):: -* GNAT.Decode_String (g-decstr.ads):: -* GNAT.Decode_UTF8_String (g-deutst.ads):: -* GNAT.Directory_Operations (g-dirope.ads):: -* GNAT.Directory_Operations.Iteration (g-diopit.ads):: -* GNAT.Dynamic_HTables (g-dynhta.ads):: -* GNAT.Dynamic_Tables (g-dyntab.ads):: -* GNAT.Encode_String (g-encstr.ads):: -* GNAT.Encode_UTF8_String (g-enutst.ads):: -* GNAT.Exception_Actions (g-excact.ads):: -* GNAT.Exception_Traces (g-exctra.ads):: -* GNAT.Exceptions (g-except.ads):: -* GNAT.Expect (g-expect.ads):: -* GNAT.Expect.TTY (g-exptty.ads):: -* GNAT.Float_Control (g-flocon.ads):: -* GNAT.Formatted_String (g-forstr.ads):: -* GNAT.Heap_Sort (g-heasor.ads):: -* GNAT.Heap_Sort_A (g-hesora.ads):: -* GNAT.Heap_Sort_G (g-hesorg.ads):: -* GNAT.HTable (g-htable.ads):: -* GNAT.IO (g-io.ads):: -* GNAT.IO_Aux (g-io_aux.ads):: -* GNAT.Lock_Files (g-locfil.ads):: -* GNAT.MBBS_Discrete_Random (g-mbdira.ads):: -* GNAT.MBBS_Float_Random (g-mbflra.ads):: -* GNAT.MD5 (g-md5.ads):: -* GNAT.Memory_Dump (g-memdum.ads):: -* GNAT.Most_Recent_Exception (g-moreex.ads):: -* GNAT.OS_Lib (g-os_lib.ads):: -* GNAT.Perfect_Hash_Generators (g-pehage.ads):: -* GNAT.Random_Numbers (g-rannum.ads):: -* GNAT.Regexp (g-regexp.ads):: -* GNAT.Registry (g-regist.ads):: -* GNAT.Regpat (g-regpat.ads):: -* GNAT.Rewrite_Data (g-rewdat.ads):: -* GNAT.Secondary_Stack_Info (g-sestin.ads):: -* GNAT.Semaphores (g-semaph.ads):: -* GNAT.Serial_Communications (g-sercom.ads):: -* GNAT.SHA1 (g-sha1.ads):: -* GNAT.SHA224 (g-sha224.ads):: -* GNAT.SHA256 (g-sha256.ads):: -* GNAT.SHA384 (g-sha384.ads):: -* GNAT.SHA512 (g-sha512.ads):: -* GNAT.Signals (g-signal.ads):: -* GNAT.Sockets (g-socket.ads):: -* GNAT.Source_Info (g-souinf.ads):: -* GNAT.Spelling_Checker (g-speche.ads):: -* GNAT.Spelling_Checker_Generic (g-spchge.ads):: -* GNAT.Spitbol.Patterns (g-spipat.ads):: -* GNAT.Spitbol (g-spitbo.ads):: -* GNAT.Spitbol.Table_Boolean (g-sptabo.ads):: -* GNAT.Spitbol.Table_Integer (g-sptain.ads):: -* GNAT.Spitbol.Table_VString (g-sptavs.ads):: -* GNAT.SSE (g-sse.ads):: -* GNAT.SSE.Vector_Types (g-ssvety.ads):: -* GNAT.Strings (g-string.ads):: -* GNAT.String_Split (g-strspl.ads):: -* GNAT.Table (g-table.ads):: -* GNAT.Task_Lock (g-tasloc.ads):: -* GNAT.Threads (g-thread.ads):: -* GNAT.Time_Stamp (g-timsta.ads):: -* GNAT.Traceback (g-traceb.ads):: -* GNAT.Traceback.Symbolic (g-trasym.ads):: -* GNAT.UTF_32 (g-utf_32.ads):: -* GNAT.UTF_32_Spelling_Checker (g-u3spch.ads):: -* GNAT.Wide_Spelling_Checker (g-wispch.ads):: -* GNAT.Wide_String_Split (g-wistsp.ads):: -* GNAT.Wide_Wide_Spelling_Checker (g-zspche.ads):: -* GNAT.Wide_Wide_String_Split (g-zistsp.ads):: -* Interfaces.C.Extensions (i-cexten.ads):: -* Interfaces.C.Streams (i-cstrea.ads):: -* Interfaces.Packed_Decimal (i-pacdec.ads):: -* Interfaces.VxWorks (i-vxwork.ads):: -* Interfaces.VxWorks.IO (i-vxwoio.ads):: -* System.Address_Image (s-addima.ads):: -* System.Assertions (s-assert.ads):: -* System.Atomic_Counters (s-atocou.ads):: -* System.Memory (s-memory.ads):: -* System.Multiprocessors (s-multip.ads):: -* System.Multiprocessors.Dispatching_Domains (s-mudido.ads):: -* System.Partition_Interface (s-parint.ads):: -* System.Pool_Global (s-pooglo.ads):: -* System.Pool_Local (s-pooloc.ads):: -* System.Restrictions (s-restri.ads):: -* System.Rident (s-rident.ads):: -* System.Strings.Stream_Ops (s-ststop.ads):: -* System.Unsigned_Types (s-unstyp.ads):: -* System.Wch_Cnv (s-wchcnv.ads):: -* System.Wch_Con (s-wchcon.ads):: +* Standard I/O Packages:: +* FORM Strings:: +* Direct_IO:: +* Sequential_IO:: +* Text_IO:: +* Wide_Text_IO:: +* Wide_Wide_Text_IO:: +* Stream_IO:: +* Text Translation:: +* Shared Files:: +* Filenames encoding:: +* File content encoding:: +* Open Modes:: +* Operations on C Streams:: +* Interfacing to C Streams:: Text_IO -* Text_IO Stream Pointer Positioning:: -* Text_IO Reading and Writing Non-Regular Files:: -* Get_Immediate:: -* Treating Text_IO Files as Streams:: -* Text_IO Extensions:: -* Text_IO Facilities for Unbounded Strings:: +* Stream Pointer Positioning:: +* Reading and Writing Non-Regular Files:: +* Get_Immediate:: +* Treating Text_IO Files as Streams:: +* Text_IO Extensions:: +* Text_IO Facilities for Unbounded Strings:: Wide_Text_IO -* Wide_Text_IO Stream Pointer Positioning:: -* Wide_Text_IO Reading and Writing Non-Regular Files:: +* Stream Pointer Positioning: Stream Pointer Positioning<2>. +* Reading and Writing Non-Regular Files: Reading and Writing Non-Regular Files<2>. Wide_Wide_Text_IO -* Wide_Wide_Text_IO Stream Pointer Positioning:: -* Wide_Wide_Text_IO Reading and Writing Non-Regular Files:: +* Stream Pointer Positioning: Stream Pointer Positioning<3>. +* Reading and Writing Non-Regular Files: Reading and Writing Non-Regular Files<3>. -Interfacing to Other Languages +The GNAT Library -* Interfacing to C:: -* Interfacing to C++:: -* Interfacing to COBOL:: -* Interfacing to Fortran:: -* Interfacing to non-GNAT Ada code:: +* Ada.Characters.Latin_9 (a-chlat9.ads): Ada Characters Latin_9 a-chlat9 ads. +* Ada.Characters.Wide_Latin_1 (a-cwila1.ads): Ada Characters Wide_Latin_1 a-cwila1 ads. +* Ada.Characters.Wide_Latin_9 (a-cwila1.ads): Ada Characters Wide_Latin_9 a-cwila1 ads. +* Ada.Characters.Wide_Wide_Latin_1 (a-chzla1.ads): Ada Characters Wide_Wide_Latin_1 a-chzla1 ads. +* Ada.Characters.Wide_Wide_Latin_9 (a-chzla9.ads): Ada Characters Wide_Wide_Latin_9 a-chzla9 ads. +* Ada.Containers.Formal_Doubly_Linked_Lists (a-cfdlli.ads): Ada Containers Formal_Doubly_Linked_Lists a-cfdlli ads. +* Ada.Containers.Formal_Hashed_Maps (a-cfhama.ads): Ada Containers Formal_Hashed_Maps a-cfhama ads. +* Ada.Containers.Formal_Hashed_Sets (a-cfhase.ads): Ada Containers Formal_Hashed_Sets a-cfhase ads. +* Ada.Containers.Formal_Ordered_Maps (a-cforma.ads): Ada Containers Formal_Ordered_Maps a-cforma ads. +* Ada.Containers.Formal_Ordered_Sets (a-cforse.ads): Ada Containers Formal_Ordered_Sets a-cforse ads. +* Ada.Containers.Formal_Vectors (a-cofove.ads): Ada Containers Formal_Vectors a-cofove ads. +* Ada.Containers.Formal_Indefinite_Vectors (a-cfinve.ads): Ada Containers Formal_Indefinite_Vectors a-cfinve ads. +* Ada.Containers.Bounded_Holders (a-coboho.ads): Ada Containers Bounded_Holders a-coboho ads. +* Ada.Command_Line.Environment (a-colien.ads): Ada Command_Line Environment a-colien ads. +* Ada.Command_Line.Remove (a-colire.ads): Ada Command_Line Remove a-colire ads. +* Ada.Command_Line.Response_File (a-clrefi.ads): Ada Command_Line Response_File a-clrefi ads. +* Ada.Direct_IO.C_Streams (a-diocst.ads): Ada Direct_IO C_Streams a-diocst ads. +* Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads): Ada Exceptions Is_Null_Occurrence a-einuoc ads. +* Ada.Exceptions.Last_Chance_Handler (a-elchha.ads): Ada Exceptions Last_Chance_Handler a-elchha ads. +* Ada.Exceptions.Traceback (a-exctra.ads): Ada Exceptions Traceback a-exctra ads. +* Ada.Sequential_IO.C_Streams (a-siocst.ads): Ada Sequential_IO C_Streams a-siocst ads. +* Ada.Streams.Stream_IO.C_Streams (a-ssicst.ads): Ada Streams Stream_IO C_Streams a-ssicst ads. +* Ada.Strings.Unbounded.Text_IO (a-suteio.ads): Ada Strings Unbounded Text_IO a-suteio ads. +* Ada.Strings.Wide_Unbounded.Wide_Text_IO (a-swuwti.ads): Ada Strings Wide_Unbounded Wide_Text_IO a-swuwti ads. +* Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO (a-szuzti.ads): Ada Strings Wide_Wide_Unbounded Wide_Wide_Text_IO a-szuzti ads. +* Ada.Text_IO.C_Streams (a-tiocst.ads): Ada Text_IO C_Streams a-tiocst ads. +* Ada.Text_IO.Reset_Standard_Files (a-tirsfi.ads): Ada Text_IO Reset_Standard_Files a-tirsfi ads. +* Ada.Wide_Characters.Unicode (a-wichun.ads): Ada Wide_Characters Unicode a-wichun ads. +* Ada.Wide_Text_IO.C_Streams (a-wtcstr.ads): Ada Wide_Text_IO C_Streams a-wtcstr ads. +* Ada.Wide_Text_IO.Reset_Standard_Files (a-wrstfi.ads): Ada Wide_Text_IO Reset_Standard_Files a-wrstfi ads. +* Ada.Wide_Wide_Characters.Unicode (a-zchuni.ads): Ada Wide_Wide_Characters Unicode a-zchuni ads. +* Ada.Wide_Wide_Text_IO.C_Streams (a-ztcstr.ads): Ada Wide_Wide_Text_IO C_Streams a-ztcstr ads. +* Ada.Wide_Wide_Text_IO.Reset_Standard_Files (a-zrstfi.ads): Ada Wide_Wide_Text_IO Reset_Standard_Files a-zrstfi ads. +* GNAT.Altivec (g-altive.ads): GNAT Altivec g-altive ads. +* GNAT.Altivec.Conversions (g-altcon.ads): GNAT Altivec Conversions g-altcon ads. +* GNAT.Altivec.Vector_Operations (g-alveop.ads): GNAT Altivec Vector_Operations g-alveop ads. +* GNAT.Altivec.Vector_Types (g-alvety.ads): GNAT Altivec Vector_Types g-alvety ads. +* GNAT.Altivec.Vector_Views (g-alvevi.ads): GNAT Altivec Vector_Views g-alvevi ads. +* GNAT.Array_Split (g-arrspl.ads): GNAT Array_Split g-arrspl ads. +* GNAT.AWK (g-awk.ads): GNAT AWK g-awk ads. +* GNAT.Bounded_Buffers (g-boubuf.ads): GNAT Bounded_Buffers g-boubuf ads. +* GNAT.Bounded_Mailboxes (g-boumai.ads): GNAT Bounded_Mailboxes g-boumai ads. +* GNAT.Bubble_Sort (g-bubsor.ads): GNAT Bubble_Sort g-bubsor ads. +* GNAT.Bubble_Sort_A (g-busora.ads): GNAT Bubble_Sort_A g-busora ads. +* GNAT.Bubble_Sort_G (g-busorg.ads): GNAT Bubble_Sort_G g-busorg ads. +* GNAT.Byte_Order_Mark (g-byorma.ads): GNAT Byte_Order_Mark g-byorma ads. +* GNAT.Byte_Swapping (g-bytswa.ads): GNAT Byte_Swapping g-bytswa ads. +* GNAT.Calendar (g-calend.ads): GNAT Calendar g-calend ads. +* GNAT.Calendar.Time_IO (g-catiio.ads): GNAT Calendar Time_IO g-catiio ads. +* GNAT.CRC32 (g-crc32.ads): GNAT CRC32 g-crc32 ads. +* GNAT.Case_Util (g-casuti.ads): GNAT Case_Util g-casuti ads. +* GNAT.CGI (g-cgi.ads): GNAT CGI g-cgi ads. +* GNAT.CGI.Cookie (g-cgicoo.ads): GNAT CGI Cookie g-cgicoo ads. +* GNAT.CGI.Debug (g-cgideb.ads): GNAT CGI Debug g-cgideb ads. +* GNAT.Command_Line (g-comlin.ads): GNAT Command_Line g-comlin ads. +* GNAT.Compiler_Version (g-comver.ads): GNAT Compiler_Version g-comver ads. +* GNAT.Ctrl_C (g-ctrl_c.ads): GNAT Ctrl_C g-ctrl_c ads. +* GNAT.Current_Exception (g-curexc.ads): GNAT Current_Exception g-curexc ads. +* GNAT.Debug_Pools (g-debpoo.ads): GNAT Debug_Pools g-debpoo ads. +* GNAT.Debug_Utilities (g-debuti.ads): GNAT Debug_Utilities g-debuti ads. +* GNAT.Decode_String (g-decstr.ads): GNAT Decode_String g-decstr ads. +* GNAT.Decode_UTF8_String (g-deutst.ads): GNAT Decode_UTF8_String g-deutst ads. +* GNAT.Directory_Operations (g-dirope.ads): GNAT Directory_Operations g-dirope ads. +* GNAT.Directory_Operations.Iteration (g-diopit.ads): GNAT Directory_Operations Iteration g-diopit ads. +* GNAT.Dynamic_HTables (g-dynhta.ads): GNAT Dynamic_HTables g-dynhta ads. +* GNAT.Dynamic_Tables (g-dyntab.ads): GNAT Dynamic_Tables g-dyntab ads. +* GNAT.Encode_String (g-encstr.ads): GNAT Encode_String g-encstr ads. +* GNAT.Encode_UTF8_String (g-enutst.ads): GNAT Encode_UTF8_String g-enutst ads. +* GNAT.Exception_Actions (g-excact.ads): GNAT Exception_Actions g-excact ads. +* GNAT.Exception_Traces (g-exctra.ads): GNAT Exception_Traces g-exctra ads. +* GNAT.Exceptions (g-expect.ads): GNAT Exceptions g-expect ads. +* GNAT.Expect (g-expect.ads): GNAT Expect g-expect ads. +* GNAT.Expect.TTY (g-exptty.ads): GNAT Expect TTY g-exptty ads. +* GNAT.Float_Control (g-flocon.ads): GNAT Float_Control g-flocon ads. +* GNAT.Formatted_String (g-forstr.ads): GNAT Formatted_String g-forstr ads. +* GNAT.Heap_Sort (g-heasor.ads): GNAT Heap_Sort g-heasor ads. +* GNAT.Heap_Sort_A (g-hesora.ads): GNAT Heap_Sort_A g-hesora ads. +* GNAT.Heap_Sort_G (g-hesorg.ads): GNAT Heap_Sort_G g-hesorg ads. +* GNAT.HTable (g-htable.ads): GNAT HTable g-htable ads. +* GNAT.IO (g-io.ads): GNAT IO g-io ads. +* GNAT.IO_Aux (g-io_aux.ads): GNAT IO_Aux g-io_aux ads. +* GNAT.Lock_Files (g-locfil.ads): GNAT Lock_Files g-locfil ads. +* GNAT.MBBS_Discrete_Random (g-mbdira.ads): GNAT MBBS_Discrete_Random g-mbdira ads. +* GNAT.MBBS_Float_Random (g-mbflra.ads): GNAT MBBS_Float_Random g-mbflra ads. +* GNAT.MD5 (g-md5.ads): GNAT MD5 g-md5 ads. +* GNAT.Memory_Dump (g-memdum.ads): GNAT Memory_Dump g-memdum ads. +* GNAT.Most_Recent_Exception (g-moreex.ads): GNAT Most_Recent_Exception g-moreex ads. +* GNAT.OS_Lib (g-os_lib.ads): GNAT OS_Lib g-os_lib ads. +* GNAT.Perfect_Hash_Generators (g-pehage.ads): GNAT Perfect_Hash_Generators g-pehage ads. +* GNAT.Random_Numbers (g-rannum.ads): GNAT Random_Numbers g-rannum ads. +* GNAT.Regexp (g-regexp.ads): GNAT Regexp g-regexp ads. +* GNAT.Registry (g-regist.ads): GNAT Registry g-regist ads. +* GNAT.Regpat (g-regpat.ads): GNAT Regpat g-regpat ads. +* GNAT.Rewrite_Data (g-rewdat.ads): GNAT Rewrite_Data g-rewdat ads. +* GNAT.Secondary_Stack_Info (g-sestin.ads): GNAT Secondary_Stack_Info g-sestin ads. +* GNAT.Semaphores (g-semaph.ads): GNAT Semaphores g-semaph ads. +* GNAT.Serial_Communications (g-sercom.ads): GNAT Serial_Communications g-sercom ads. +* GNAT.SHA1 (g-sha1.ads): GNAT SHA1 g-sha1 ads. +* GNAT.SHA224 (g-sha224.ads): GNAT SHA224 g-sha224 ads. +* GNAT.SHA256 (g-sha256.ads): GNAT SHA256 g-sha256 ads. +* GNAT.SHA384 (g-sha384.ads): GNAT SHA384 g-sha384 ads. +* GNAT.SHA512 (g-sha512.ads): GNAT SHA512 g-sha512 ads. +* GNAT.Signals (g-signal.ads): GNAT Signals g-signal ads. +* GNAT.Sockets (g-socket.ads): GNAT Sockets g-socket ads. +* GNAT.Source_Info (g-souinf.ads): GNAT Source_Info g-souinf ads. +* GNAT.Spelling_Checker (g-speche.ads): GNAT Spelling_Checker g-speche ads. +* GNAT.Spelling_Checker_Generic (g-spchge.ads): GNAT Spelling_Checker_Generic g-spchge ads. +* GNAT.Spitbol.Patterns (g-spipat.ads): GNAT Spitbol Patterns g-spipat ads. +* GNAT.Spitbol (g-spitbo.ads): GNAT Spitbol g-spitbo ads. +* GNAT.Spitbol.Table_Boolean (g-sptabo.ads): GNAT Spitbol Table_Boolean g-sptabo ads. +* GNAT.Spitbol.Table_Integer (g-sptain.ads): GNAT Spitbol Table_Integer g-sptain ads. +* GNAT.Spitbol.Table_VString (g-sptavs.ads): GNAT Spitbol Table_VString g-sptavs ads. +* GNAT.SSE (g-sse.ads): GNAT SSE g-sse ads. +* GNAT.SSE.Vector_Types (g-ssvety.ads): GNAT SSE Vector_Types g-ssvety ads. +* GNAT.Strings (g-string.ads): GNAT Strings g-string ads. +* GNAT.String_Split (g-strspl.ads): GNAT String_Split g-strspl ads. +* GNAT.Table (g-table.ads): GNAT Table g-table ads. +* GNAT.Task_Lock (g-tasloc.ads): GNAT Task_Lock g-tasloc ads. +* GNAT.Time_Stamp (g-timsta.ads): GNAT Time_Stamp g-timsta ads. +* GNAT.Threads (g-thread.ads): GNAT Threads g-thread ads. +* GNAT.Traceback (g-traceb.ads): GNAT Traceback g-traceb ads. +* GNAT.Traceback.Symbolic (g-trasym.ads): GNAT Traceback Symbolic g-trasym ads. +* GNAT.UTF_32 (g-table.ads): GNAT UTF_32 g-table ads. +* GNAT.Wide_Spelling_Checker (g-u3spch.ads): GNAT Wide_Spelling_Checker g-u3spch ads. +* GNAT.Wide_Spelling_Checker (g-wispch.ads): GNAT Wide_Spelling_Checker g-wispch ads. +* GNAT.Wide_String_Split (g-wistsp.ads): GNAT Wide_String_Split g-wistsp ads. +* GNAT.Wide_Wide_Spelling_Checker (g-zspche.ads): GNAT Wide_Wide_Spelling_Checker g-zspche ads. +* GNAT.Wide_Wide_String_Split (g-zistsp.ads): GNAT Wide_Wide_String_Split g-zistsp ads. +* Interfaces.C.Extensions (i-cexten.ads): Interfaces C Extensions i-cexten ads. +* Interfaces.C.Streams (i-cstrea.ads): Interfaces C Streams i-cstrea ads. +* Interfaces.Packed_Decimal (i-pacdec.ads): Interfaces Packed_Decimal i-pacdec ads. +* Interfaces.VxWorks (i-vxwork.ads): Interfaces VxWorks i-vxwork ads. +* Interfaces.VxWorks.IO (i-vxwoio.ads): Interfaces VxWorks IO i-vxwoio ads. +* System.Address_Image (s-addima.ads): System Address_Image s-addima ads. +* System.Assertions (s-assert.ads): System Assertions s-assert ads. +* System.Atomic_Counters (s-atocou.ads): System Atomic_Counters s-atocou ads. +* System.Memory (s-memory.ads): System Memory s-memory ads. +* System.Multiprocessors (s-multip.ads): System Multiprocessors s-multip ads. +* System.Multiprocessors.Dispatching_Domains (s-mudido.ads): System Multiprocessors Dispatching_Domains s-mudido ads. +* System.Partition_Interface (s-parint.ads): System Partition_Interface s-parint ads. +* System.Pool_Global (s-pooglo.ads): System Pool_Global s-pooglo ads. +* System.Pool_Local (s-pooloc.ads): System Pool_Local s-pooloc ads. +* System.Restrictions (s-restri.ads): System Restrictions s-restri ads. +* System.Rident (s-rident.ads): System Rident s-rident ads. +* System.Strings.Stream_Ops (s-ststop.ads): System Strings Stream_Ops s-ststop ads. +* System.Unsigned_Types (s-unstyp.ads): System Unsigned_Types s-unstyp ads. +* System.Wch_Cnv (s-wchcnv.ads): System Wch_Cnv s-wchcnv ads. +* System.Wch_Con (s-wchcon.ads): System Wch_Con s-wchcon ads. -Specialized Needs Annexes +Interfacing to Other Languages + +* Interfacing to C:: +* Interfacing to C++:: +* Interfacing to COBOL:: +* Interfacing to Fortran:: +* Interfacing to non-GNAT Ada code:: Implementation of Specific Ada Features -* Machine Code Insertions:: -* GNAT Implementation of Tasking:: -* GNAT Implementation of Shared Passive Packages:: -* Code Generation for Array Aggregates:: -* The Size of Discriminated Records with Default Discriminants:: -* Strict Conformance to the Ada Reference Manual:: -Implementation of Ada 2012 Features +* Machine Code Insertions:: +* GNAT Implementation of Tasking:: +* GNAT Implementation of Shared Passive Packages:: +* Code Generation for Array Aggregates:: +* The Size of Discriminated Records with Default Discriminants:: +* Strict Conformance to the Ada Reference Manual:: + +GNAT Implementation of Tasking + +* Mapping Ada Tasks onto the Underlying Kernel Threads:: +* Ensuring Compliance with the Real-Time Annex:: + +Code Generation for Array Aggregates + +* Static constant aggregates with static bounds:: +* Constant aggregates with unconstrained nominal types:: +* Aggregates with static bounds:: +* Aggregates with non-static bounds:: +* Aggregates in assignment statements:: Obsolescent Features -GNU Free Documentation License +* pragma No_Run_Time:: +* pragma Ravenscar:: +* pragma Restricted_Run_Time:: +* pragma Task_Info:: +* package System.Task_Info (s-tasinf.ads): package System Task_Info s-tasinf ads. + +Compatibility and Porting Guide + +* Writing Portable Fixed-Point Declarations:: +* Compatibility with Ada 83:: +* Compatibility between Ada 95 and Ada 2005:: +* Implementation-dependent characteristics:: +* Compatibility with Other Ada Systems:: +* Representation Clauses:: +* Compatibility with HP Ada 83:: + +Compatibility with Ada 83 + +* Legal Ada 83 programs that are illegal in Ada 95:: +* More deterministic semantics:: +* Changed semantics:: +* Other language compatibility issues:: + +Implementation-dependent characteristics + +* Implementation-defined pragmas:: +* Implementation-defined attributes:: +* Libraries:: +* Elaboration order:: +* Target-specific aspects:: -Index @end detailmenu @end menu -@end ifnottex +@node About This Guide,Implementation Defined Pragmas,Top,Top +@anchor{gnat_rm/about_this_guide about-this-guide}@anchor{2}@anchor{gnat_rm/about_this_guide doc}@anchor{3}@anchor{gnat_rm/about_this_guide gnat-reference-manual}@anchor{4}@anchor{gnat_rm/about_this_guide id1}@anchor{5} +@chapter About This Guide + -@node About This Guide -@unnumbered About This Guide -@noindent This manual contains useful information in writing programs using the -@value{EDITION} compiler. It includes information on implementation dependent -characteristics of @value{EDITION}, including all the information required by +GNAT compiler. It includes information on implementation dependent +characteristics of GNAT, including all the information required by Annex M of the Ada language standard. -@value{EDITION} implements Ada 95, Ada 2005 and Ada 2012, and it may also be +GNAT implements Ada 95, Ada 2005 and Ada 2012, and it may also be invoked in Ada 83 compatibility mode. -By default, @value{EDITION} assumes Ada 2012, +By default, GNAT assumes Ada 2012, but you can override with a compiler switch to explicitly specify the language version. -(Please refer to @ref{Compiling Different Versions of Ada,,, gnat_ugn, -@value{EDITION} User's Guide}, for details on these switches.) -Throughout this manual, references to ``Ada'' without a year suffix +(Please refer to the @emph{GNAT User's Guide} for details on these switches.) +Throughout this manual, references to 'Ada' without a year suffix apply to all the Ada versions of the language. Ada is designed to be highly portable. @@ -754,208 +890,225 @@ different compilers on different platforms. However, since Ada is designed to be used in a wide variety of applications, it also contains a number of system dependent features to be used in interfacing to the external world. -@cindex Implementation-dependent features -@cindex Portability +.. index:: Implementation-dependent features + +@geindex Portability Note: Any program that makes use of implementation-dependent features may be non-portable. You should follow good programming practice and isolate and clearly document any sections of your program that make use of these features in a non-portable manner. -@ifset PROEDITION -For ease of exposition, ``@value{EDITION}'' will be referred to simply as -``GNAT'' in the remainder of this document. -@end ifset - @menu -* What This Reference Manual Contains:: -* Conventions:: -* Related Information:: +* What This Reference Manual Contains:: +* Conventions:: +* Related Information:: + @end menu -@node What This Reference Manual Contains -@unnumberedsec What This Reference Manual Contains +@node What This Reference Manual Contains,Conventions,,About This Guide +@anchor{gnat_rm/about_this_guide what-this-reference-manual-contains}@anchor{6} +@section What This Reference Manual Contains + -@noindent This reference manual contains the following chapters: -@itemize @bullet -@item -@ref{Implementation Defined Pragmas}, lists GNAT implementation-dependent + +@itemize * + +@item +@ref{7,,Implementation Defined Pragmas}, lists GNAT implementation-dependent pragmas, which can be used to extend and enhance the functionality of the compiler. -@item -@ref{Implementation Defined Attributes}, lists GNAT +@item +@ref{8,,Implementation Defined Attributes}, lists GNAT implementation-dependent attributes, which can be used to extend and enhance the functionality of the compiler. -@item -@ref{Standard and Implementation Defined Restrictions}, lists GNAT +@item +@ref{9,,Standard and Implementation Defined Restrictions}, lists GNAT implementation-dependent restrictions, which can be used to extend and enhance the functionality of the compiler. -@item -@ref{Implementation Advice}, provides information on generally +@item +@ref{a,,Implementation Advice}, provides information on generally desirable behavior which are not requirements that all compilers must follow since it cannot be provided on all systems, or which may be undesirable on some systems. -@item -@ref{Implementation Defined Characteristics}, provides a guide to +@item +@ref{b,,Implementation Defined Characteristics}, provides a guide to minimizing implementation dependent features. -@item -@ref{Intrinsic Subprograms}, describes the intrinsic subprograms +@item +@ref{c,,Intrinsic Subprograms}, describes the intrinsic subprograms implemented by GNAT, and how they can be imported into user application programs. -@item -@ref{Representation Clauses and Pragmas}, describes in detail the +@item +@ref{d,,Representation Clauses and Pragmas}, describes in detail the way that GNAT represents data, and in particular the exact set of representation clauses and pragmas that is accepted. -@item -@ref{Standard Library Routines}, provides a listing of packages and a +@item +@ref{e,,Standard Library Routines}, provides a listing of packages and a brief description of the functionality that is provided by Ada's -extensive set of standard library routines as implemented by GNAT@. +extensive set of standard library routines as implemented by GNAT. -@item -@ref{The Implementation of Standard I/O}, details how the GNAT +@item +@ref{f,,The Implementation of Standard I/O}, details how the GNAT implementation of the input-output facilities. -@item -@ref{The GNAT Library}, is a catalog of packages that complement +@item +@ref{10,,The GNAT Library}, is a catalog of packages that complement the Ada predefined library. -@item -@ref{Interfacing to Other Languages}, describes how programs +@item +@ref{11,,Interfacing to Other Languages}, describes how programs written in Ada using GNAT can be interfaced to other programming languages. -@ref{Specialized Needs Annexes}, describes the GNAT implementation of all +@item +@ref{12,,Specialized Needs Annexes}, describes the GNAT implementation of all of the specialized needs annexes. -@item -@ref{Implementation of Specific Ada Features}, discusses issues related +@item +@ref{13,,Implementation of Specific Ada Features}, discusses issues related to GNAT's implementation of machine code insertions, tasking, and several other features. -@item -@ref{Implementation of Ada 2012 Features}, describes the status of the +@item +@ref{14,,Implementation of Ada 2012 Features}, describes the status of the GNAT implementation of the Ada 2012 language standard. -@item -@ref{Obsolescent Features} documents implementation dependent features, +@item +@ref{15,,Obsolescent Features} documents implementation dependent features, including pragmas and attributes, which are considered obsolescent, since there are other preferred ways of achieving the same results. These obsolescent forms are retained for backwards compatibility. +@item +@ref{16,,Compatibility and Porting Guide} presents some guidelines for +developing portable Ada code, describes the compatibility issues that +may arise between GNAT and other Ada compilation systems (including those +for Ada 83), and shows how GNAT can expedite porting applications +developed in other Ada environments. + +@item +@ref{1,,GNU Free Documentation License} contains the license for this document. @end itemize -@cindex Ada 95 Language Reference Manual -@cindex Ada 2005 Language Reference Manual -@noindent +@geindex Ada 95 Language Reference Manual + +@geindex Ada 2005 Language Reference Manual + This reference manual assumes a basic familiarity with the Ada 95 language, as -described in the International Standard ANSI/ISO/IEC-8652:1995, -January 1995. +described in the +@cite{International Standard ANSI/ISO/IEC-8652:1995}. It does not require knowledge of the new features introduced by Ada 2005, -(officially known as ISO/IEC 8652:1995 with Technical Corrigendum 1 -and Amendment 1). +(officially known as @cite{ISO/IEC 8652:1995 with Technical Corrigendum 1 and Amendment 1}). Both reference manuals are included in the GNAT documentation package. -@node Conventions -@unnumberedsec Conventions -@cindex Conventions, typographical -@cindex Typographical conventions +@node Conventions,Related Information,What This Reference Manual Contains,About This Guide +@anchor{gnat_rm/about_this_guide conventions}@anchor{17} +@section Conventions + + +@geindex Conventions +@geindex typographical + +@geindex Typographical conventions -@noindent Following are examples of the typographical and graphic conventions used in this guide: -@itemize @bullet -@item -@code{Functions}, @code{utility program names}, @code{standard names}, -and @code{classes}. -@item -@code{Option flags} +@itemize * -@item -@file{File names}, @samp{button names}, and @samp{field names}. +@item +@cite{Functions}, @cite{utility program names}, @cite{standard names}, +and @cite{classes}. -@item -@code{Variables}, @env{environment variables}, and @var{metasyntactic -variables}. +@item +@cite{Option flags} -@item -@emph{Emphasis}. +@item +@code{File names} -@item +@item +@cite{Variables} + +@item +@emph{Emphasis} + +@item [optional information or parameters] -@item +@item Examples are described by text -@smallexample + +@example and then shown this way. -@end smallexample +@end example + +@item +Commands that are entered by the user are shown as preceded by a prompt string +comprising the @code{$} character followed by a space. @end itemize -@noindent -Commands that are entered by the user are preceded in this manual by the -characters @samp{$ } (dollar sign followed by space). If your system uses this -sequence as a prompt, then the commands will appear exactly as you see them -in the manual. If your system uses some other prompt, then the command will -appear with the @samp{$} replaced by whatever prompt character you are using. +@node Related Information,,Conventions,About This Guide +@anchor{gnat_rm/about_this_guide related-information}@anchor{18} +@section Related Information + -@node Related Information -@unnumberedsec Related Information -@noindent See the following documents for further information on GNAT: -@itemize @bullet -@item -@xref{Top, @value{EDITION} User's Guide, About This Guide, gnat_ugn, -@value{EDITION} User's Guide}, which provides information on how to use the -GNAT compiler system. -@item -@cite{Ada 95 Reference Manual}, which contains all reference -material for the Ada 95 programming language. +@itemize * -@item +@item +@cite{GNAT User's Guide for Native Platforms}, +which provides information on how to use the +GNAT development environment. + +@item +@cite{Ada 95 Reference Manual}, the Ada 95 programming language standard. + +@item @cite{Ada 95 Annotated Reference Manual}, which is an annotated version of the Ada 95 standard. The annotations describe detailed aspects of the design decision, and in particular contain useful sections on Ada 83 compatibility. -@item -@cite{Ada 2005 Reference Manual}, which contains all reference -material for the Ada 2005 programming language. +@item +@cite{Ada 2005 Reference Manual}, the Ada 2005 programming language standard. -@item +@item @cite{Ada 2005 Annotated Reference Manual}, which is an annotated version of the Ada 2005 standard. The annotations describe -detailed aspects of the design decision, and in particular contain useful -sections on Ada 83 and Ada 95 compatibility. +detailed aspects of the design decision. -@item -@cite{DEC Ada, Technical Overview and Comparison on DIGITAL Platforms}, +@item +@cite{Ada 2012 Reference Manual}, the Ada 2012 programming language standard. + +@item +@cite{DEC Ada@comma{} Technical Overview and Comparison on DIGITAL Platforms}, which contains specific information on compatibility between GNAT and DEC Ada 83 systems. -@item -@cite{DEC Ada, Language Reference Manual, part number AA-PYZAB-TK} which +@item +@cite{DEC Ada@comma{} Language Reference Manual}, part number AA-PYZAB-TK, which describes in detail the pragmas and attributes provided by the DEC Ada 83 compiler system. - @end itemize -@node Implementation Defined Pragmas +@node Implementation Defined Pragmas,Implementation Defined Aspects,About This Guide,Top +@anchor{gnat_rm/implementation_defined_pragmas implementation-defined-pragmas}@anchor{7}@anchor{gnat_rm/implementation_defined_pragmas doc}@anchor{19}@anchor{gnat_rm/implementation_defined_pragmas id1}@anchor{1a} @chapter Implementation Defined Pragmas -@noindent + Ada defines a set of pragmas that can be used to supply additional information to the compiler. These language defined pragmas are implemented in GNAT and work as described in the Ada Reference Manual. @@ -972,237 +1125,238 @@ platforms). Therefore if portability to other compilers is an important consideration, the use of these pragmas should be minimized. @menu -* Pragma Abort_Defer:: -* Pragma Abstract_State:: -* Pragma Ada_83:: -* Pragma Ada_95:: -* Pragma Ada_05:: -* Pragma Ada_2005:: -* Pragma Ada_12:: -* Pragma Ada_2012:: -* Pragma Allow_Integer_Address:: -* Pragma Annotate:: -* Pragma Assert:: -* Pragma Assert_And_Cut:: -* Pragma Assertion_Policy:: -* Pragma Assume:: -* Pragma Assume_No_Invalid_Values:: -* Pragma AST_Entry:: -* Pragma Async_Readers:: -* Pragma Async_Writers:: -* Pragma Attribute_Definition:: -* Pragma C_Pass_By_Copy:: -* Pragma Check:: -* Pragma Check_Float_Overflow:: -* Pragma Check_Name:: -* Pragma Check_Policy:: -* Pragma CIL_Constructor:: -* Pragma Comment:: -* Pragma Common_Object:: -* Pragma Compile_Time_Error:: -* Pragma Compile_Time_Warning:: -* Pragma Compiler_Unit:: -* Pragma Compiler_Unit_Warning:: -* Pragma Complete_Representation:: -* Pragma Complex_Representation:: -* Pragma Component_Alignment:: -* Pragma Contract_Cases:: -* Pragma Convention_Identifier:: -* Pragma CPP_Class:: -* Pragma CPP_Constructor:: -* Pragma CPP_Virtual:: -* Pragma CPP_Vtable:: -* Pragma CPU:: -* Pragma Debug:: -* Pragma Debug_Policy:: -* Pragma Default_Scalar_Storage_Order:: -* Pragma Default_Storage_Pool:: -* Pragma Depends:: -* Pragma Detect_Blocking:: -* Pragma Disable_Atomic_Synchronization:: -* Pragma Dispatching_Domain:: -* Pragma Effective_Reads:: -* Pragma Effective_Writes:: -* Pragma Elaboration_Checks:: -* Pragma Eliminate:: -* Pragma Enable_Atomic_Synchronization:: -* Pragma Export_Exception:: -* Pragma Export_Function:: -* Pragma Export_Object:: -* Pragma Export_Procedure:: -* Pragma Export_Value:: -* Pragma Export_Valued_Procedure:: -* Pragma Extend_System:: -* Pragma Extensions_Allowed:: -* Pragma External:: -* Pragma External_Name_Casing:: -* Pragma Fast_Math:: -* Pragma Favor_Top_Level:: -* Pragma Finalize_Storage_Only:: -* Pragma Float_Representation:: -* Pragma Global:: -* Pragma Ident:: -* Pragma Implementation_Defined:: -* Pragma Implemented:: -* Pragma Implicit_Packing:: -* Pragma Import_Exception:: -* Pragma Import_Function:: -* Pragma Import_Object:: -* Pragma Import_Procedure:: -* Pragma Import_Valued_Procedure:: -* Pragma Independent:: -* Pragma Independent_Components:: -* Pragma Initial_Condition:: -* Pragma Initialize_Scalars:: -* Pragma Initializes:: -* Pragma Inline_Always:: -* Pragma Inline_Generic:: -* Pragma Interface:: -* Pragma Interface_Name:: -* Pragma Interrupt_Handler:: -* Pragma Interrupt_State:: -* Pragma Invariant:: -* Pragma Java_Constructor:: -* Pragma Java_Interface:: -* Pragma Keep_Names:: -* Pragma License:: -* Pragma Link_With:: -* Pragma Linker_Alias:: -* Pragma Linker_Constructor:: -* Pragma Linker_Destructor:: -* Pragma Linker_Section:: -* Pragma Lock_Free:: -* Pragma Long_Float:: -* Pragma Loop_Invariant:: -* Pragma Loop_Optimize:: -* Pragma Loop_Variant:: -* Pragma Machine_Attribute:: -* Pragma Main:: -* Pragma Main_Storage:: -* Pragma No_Body:: -* Pragma No_Elaboration_Code_All:: -* Pragma No_Inline:: -* Pragma No_Return:: -* Pragma No_Run_Time:: -* Pragma No_Strict_Aliasing:: -* Pragma No_Tagged_Streams:: -* Pragma Normalize_Scalars:: -* Pragma Obsolescent:: -* Pragma Optimize_Alignment:: -* Pragma Ordered:: -* Pragma Overflow_Mode:: -* Pragma Overriding_Renamings:: -* Pragma Partition_Elaboration_Policy:: -* Pragma Part_Of:: -* Pragma Passive:: -* Pragma Persistent_BSS:: -* Pragma Polling:: -* Pragma Post:: -* Pragma Postcondition:: -* Pragma Post_Class:: -* Pragma Pre:: -* Pragma Precondition:: -* Pragma Predicate:: -* Pragma Preelaborable_Initialization:: -* Pragma Prefix_Exception_Messages:: -* Pragma Pre_Class:: -* Pragma Priority_Specific_Dispatching:: -* Pragma Profile:: -* Pragma Profile_Warnings:: -* Pragma Propagate_Exceptions:: -* Pragma Provide_Shift_Operators:: -* Pragma Psect_Object:: -* Pragma Pure_Function:: -* Pragma Rational:: -* Pragma Ravenscar:: -* Pragma Refined_Depends:: -* Pragma Refined_Global:: -* Pragma Refined_Post:: -* Pragma Refined_State:: -* Pragma Relative_Deadline:: -* Pragma Remote_Access_Type:: -* Pragma Restricted_Run_Time:: -* Pragma Restriction_Warnings:: -* Pragma Reviewable:: -* Pragma Share_Generic:: -* Pragma Shared:: -* Pragma Short_Circuit_And_Or:: -* Pragma Short_Descriptors:: -* Pragma Simple_Storage_Pool_Type:: -* Pragma Source_File_Name:: -* Pragma Source_File_Name_Project:: -* Pragma Source_Reference:: -* Pragma SPARK_Mode:: -* Pragma Static_Elaboration_Desired:: -* Pragma Stream_Convert:: -* Pragma Style_Checks:: -* Pragma Subtitle:: -* Pragma Suppress:: -* Pragma Suppress_All:: -* Pragma Suppress_Debug_Info:: -* Pragma Suppress_Exception_Locations:: -* Pragma Suppress_Initialization:: -* Pragma Task_Name:: -* Pragma Task_Storage:: -* Pragma Test_Case:: -* Pragma Thread_Local_Storage:: -* Pragma Time_Slice:: -* Pragma Title:: -* Pragma Type_Invariant:: -* Pragma Type_Invariant_Class:: -* Pragma Unchecked_Union:: -* Pragma Unevaluated_Use_Of_Old:: -* Pragma Unimplemented_Unit:: -* Pragma Universal_Aliasing :: -* Pragma Universal_Data:: -* Pragma Unmodified:: -* Pragma Unreferenced:: -* Pragma Unreferenced_Objects:: -* Pragma Unreserve_All_Interrupts:: -* Pragma Unsuppress:: -* Pragma Use_VADS_Size:: -* Pragma Validity_Checks:: -* Pragma Volatile:: -* Pragma Warning_As_Error:: -* Pragma Warnings:: -* Pragma Weak_External:: -* Pragma Wide_Character_Encoding:: +* Pragma Abort_Defer:: +* Pragma Abstract_State:: +* Pragma Ada_83:: +* Pragma Ada_95:: +* Pragma Ada_05:: +* Pragma Ada_2005:: +* Pragma Ada_12:: +* Pragma Ada_2012:: +* Pragma Allow_Integer_Address:: +* Pragma Annotate:: +* Pragma Assert:: +* Pragma Assert_And_Cut:: +* Pragma Assertion_Policy:: +* Pragma Assume:: +* Pragma Assume_No_Invalid_Values:: +* Pragma Async_Readers:: +* Pragma Async_Writers:: +* Pragma Attribute_Definition:: +* Pragma C_Pass_By_Copy:: +* Pragma Check:: +* Pragma Check_Float_Overflow:: +* Pragma Check_Name:: +* Pragma Check_Policy:: +* Pragma CIL_Constructor:: +* Pragma Comment:: +* Pragma Common_Object:: +* Pragma Compile_Time_Error:: +* Pragma Compile_Time_Warning:: +* Pragma Compiler_Unit:: +* Pragma Compiler_Unit_Warning:: +* Pragma Complete_Representation:: +* Pragma Complex_Representation:: +* Pragma Component_Alignment:: +* Pragma Contract_Cases:: +* Pragma Convention_Identifier:: +* Pragma CPP_Class:: +* Pragma CPP_Constructor:: +* Pragma CPP_Virtual:: +* Pragma CPP_Vtable:: +* Pragma CPU:: +* Pragma Debug:: +* Pragma Debug_Policy:: +* Pragma Default_Scalar_Storage_Order:: +* Pragma Default_Storage_Pool:: +* Pragma Depends:: +* Pragma Detect_Blocking:: +* Pragma Disable_Atomic_Synchronization:: +* Pragma Dispatching_Domain:: +* Pragma Effective_Reads:: +* Pragma Effective_Writes:: +* Pragma Elaboration_Checks:: +* Pragma Eliminate:: +* Pragma Enable_Atomic_Synchronization:: +* Pragma Export_Function:: +* Pragma Export_Object:: +* Pragma Export_Procedure:: +* Pragma Export_Value:: +* Pragma Export_Valued_Procedure:: +* Pragma Extend_System:: +* Pragma Extensions_Allowed:: +* Pragma External:: +* Pragma External_Name_Casing:: +* Pragma Fast_Math:: +* Pragma Favor_Top_Level:: +* Pragma Finalize_Storage_Only:: +* Pragma Float_Representation:: +* Pragma Global:: +* Pragma Ident:: +* Pragma Implementation_Defined:: +* Pragma Implemented:: +* Pragma Implicit_Packing:: +* Pragma Import_Function:: +* Pragma Import_Object:: +* Pragma Import_Procedure:: +* Pragma Import_Valued_Procedure:: +* Pragma Independent:: +* Pragma Independent_Components:: +* Pragma Initial_Condition:: +* Pragma Initialize_Scalars:: +* Pragma Initializes:: +* Pragma Inline_Always:: +* Pragma Inline_Generic:: +* Pragma Interface:: +* Pragma Interface_Name:: +* Pragma Interrupt_Handler:: +* Pragma Interrupt_State:: +* Pragma Invariant:: +* Pragma Java_Constructor:: +* Pragma Java_Interface:: +* Pragma Keep_Names:: +* Pragma License:: +* Pragma Link_With:: +* Pragma Linker_Alias:: +* Pragma Linker_Constructor:: +* Pragma Linker_Destructor:: +* Pragma Linker_Section:: +* Pragma Lock_Free:: +* Pragma Loop_Invariant:: +* Pragma Loop_Optimize:: +* Pragma Loop_Variant:: +* Pragma Machine_Attribute:: +* Pragma Main:: +* Pragma Main_Storage:: +* Pragma No_Body:: +* Pragma No_Elaboration_Code_All:: +* Pragma No_Inline:: +* Pragma No_Return:: +* Pragma No_Run_Time:: +* Pragma No_Strict_Aliasing:: +* Pragma No_Tagged_Streams:: +* Pragma Normalize_Scalars:: +* Pragma Obsolescent:: +* Pragma Optimize_Alignment:: +* Pragma Ordered:: +* Pragma Overflow_Mode:: +* Pragma Overriding_Renamings:: +* Pragma Partition_Elaboration_Policy:: +* Pragma Part_Of:: +* Pragma Passive:: +* Pragma Persistent_BSS:: +* Pragma Polling:: +* Pragma Post:: +* Pragma Postcondition:: +* Pragma Post_Class:: +* Pragma Pre:: +* Pragma Precondition:: +* Pragma Predicate:: +* Pragma Preelaborable_Initialization:: +* Pragma Prefix_Exception_Messages:: +* Pragma Pre_Class:: +* Pragma Priority_Specific_Dispatching:: +* Pragma Profile:: +* Pragma Profile_Warnings:: +* Pragma Propagate_Exceptions:: +* Pragma Provide_Shift_Operators:: +* Pragma Psect_Object:: +* Pragma Pure_Function:: +* Pragma Rational:: +* Pragma Ravenscar:: +* Pragma Refined_Depends:: +* Pragma Refined_Global:: +* Pragma Refined_Post:: +* Pragma Refined_State:: +* Pragma Relative_Deadline:: +* Pragma Remote_Access_Type:: +* Pragma Restricted_Run_Time:: +* Pragma Restriction_Warnings:: +* Pragma Reviewable:: +* Pragma Share_Generic:: +* Pragma Shared:: +* Pragma Short_Circuit_And_Or:: +* Pragma Short_Descriptors:: +* Pragma Simple_Storage_Pool_Type:: +* Pragma Source_File_Name:: +* Pragma Source_File_Name_Project:: +* Pragma Source_Reference:: +* Pragma SPARK_Mode:: +* Pragma Static_Elaboration_Desired:: +* Pragma Stream_Convert:: +* Pragma Style_Checks:: +* Pragma Subtitle:: +* Pragma Suppress:: +* Pragma Suppress_All:: +* Pragma Suppress_Debug_Info:: +* Pragma Suppress_Exception_Locations:: +* Pragma Suppress_Initialization:: +* Pragma Task_Name:: +* Pragma Task_Storage:: +* Pragma Test_Case:: +* Pragma Thread_Local_Storage:: +* Pragma Time_Slice:: +* Pragma Title:: +* Pragma Type_Invariant:: +* Pragma Type_Invariant_Class:: +* Pragma Unchecked_Union:: +* Pragma Unevaluated_Use_Of_Old:: +* Pragma Unimplemented_Unit:: +* Pragma Universal_Aliasing:: +* Pragma Universal_Data:: +* Pragma Unmodified:: +* Pragma Unreferenced:: +* Pragma Unreferenced_Objects:: +* Pragma Unreserve_All_Interrupts:: +* Pragma Unsuppress:: +* Pragma Use_VADS_Size:: +* Pragma Validity_Checks:: +* Pragma Volatile:: +* Pragma Warning_As_Error:: +* Pragma Warnings:: +* Pragma Weak_External:: +* Pragma Wide_Character_Encoding:: + @end menu -@node Pragma Abort_Defer -@unnumberedsec Pragma Abort_Defer -@findex Abort_Defer -@cindex Deferring aborts -@noindent +@node Pragma Abort_Defer,Pragma Abstract_State,,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-abort-defer}@anchor{1b} +@section Pragma Abort_Defer + + +@geindex Deferring aborts + Syntax: -@smallexample + +@example pragma Abort_Defer; -@end smallexample +@end example -@noindent This pragma must appear at the start of the statement sequence of a -handled sequence of statements (right after the @code{begin}). It has +handled sequence of statements (right after the @cite{begin}). It has the effect of deferring aborts for the sequence of statements (but not for the declarations or handlers, if any, associated with this statement sequence). -@node Pragma Abstract_State -@unnumberedsec Pragma Abstract_State -@findex Abstract_State -@noindent +@node Pragma Abstract_State,Pragma Ada_83,Pragma Abort_Defer,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-abstract-state}@anchor{1c} +@section Pragma Abstract_State + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.1.4. -@node Pragma Ada_83 -@unnumberedsec Pragma Ada_83 -@findex Ada_83 -@noindent +@node Pragma Ada_83,Pragma Ada_95,Pragma Abstract_State,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-ada-83}@anchor{1d} +@section Pragma Ada_83 + + Syntax: -@smallexample @c ada + +@example pragma Ada_83; -@end smallexample +@end example -@noindent A configuration pragma that establishes Ada 83 mode for the unit to which it applies, regardless of the mode set by the command line switches. In Ada 83 mode, GNAT attempts to be as compatible with @@ -1210,7 +1364,7 @@ the syntax and semantics of Ada 83, as defined in the original Ada 83 Reference Manual as possible. In particular, the keywords added by Ada 95 and Ada 2005 are not recognized, optional package bodies are allowed, and generics may name types with unknown discriminants without using -the @code{(<>)} notation. In addition, some but not all of the additional +the @cite{(<>)} notation. In addition, some but not all of the additional restrictions of Ada 83 are enforced. Ada 83 mode is intended for two purposes. Firstly, it allows existing @@ -1221,35 +1375,37 @@ by GNAT in Ada 83 mode will in fact compile and execute with an Ada 83 compiler, since GNAT does not enforce all the additional checks required by Ada 83. -@node Pragma Ada_95 -@unnumberedsec Pragma Ada_95 -@findex Ada_95 -@noindent +@node Pragma Ada_95,Pragma Ada_05,Pragma Ada_83,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-ada-95}@anchor{1e} +@section Pragma Ada_95 + + Syntax: -@smallexample @c ada + +@example pragma Ada_95; -@end smallexample +@end example -@noindent A configuration pragma that establishes Ada 95 mode for the unit to which it applies, regardless of the mode set by the command line switches. -This mode is set automatically for the @code{Ada} and @code{System} +This mode is set automatically for the @cite{Ada} and @cite{System} packages and their children, so you need not specify it in these contexts. This pragma is useful when writing a reusable component that itself uses Ada 95 features, but which is intended to be usable from either Ada 83 or Ada 95 programs. -@node Pragma Ada_05 -@unnumberedsec Pragma Ada_05 -@findex Ada_05 -@noindent +@node Pragma Ada_05,Pragma Ada_2005,Pragma Ada_95,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-ada-05}@anchor{1f} +@section Pragma Ada_05 + + Syntax: -@smallexample @c ada + +@example pragma Ada_05; pragma Ada_05 (local_NAME); -@end smallexample +@end example -@noindent A configuration pragma that establishes Ada 2005 mode for the unit to which it applies, regardless of the mode set by the command line switches. This pragma is useful when writing a reusable component that @@ -1267,33 +1423,35 @@ extra subprograms marked this way from generating ambiguities in otherwise legal pre-Ada_2005 programs. The one argument form is intended for exclusive use in the GNAT run-time library. -@node Pragma Ada_2005 -@unnumberedsec Pragma Ada_2005 -@findex Ada_2005 -@noindent +@node Pragma Ada_2005,Pragma Ada_12,Pragma Ada_05,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-ada-2005}@anchor{20} +@section Pragma Ada_2005 + + Syntax: -@smallexample @c ada + +@example pragma Ada_2005; -@end smallexample +@end example -@noindent This configuration pragma is a synonym for pragma Ada_05 and has the same syntax and effect. -@node Pragma Ada_12 -@unnumberedsec Pragma Ada_12 -@findex Ada_12 -@noindent +@node Pragma Ada_12,Pragma Ada_2012,Pragma Ada_2005,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-ada-12}@anchor{21} +@section Pragma Ada_12 + + Syntax: -@smallexample @c ada + +@example pragma Ada_12; pragma Ada_12 (local_NAME); -@end smallexample +@end example -@noindent A configuration pragma that establishes Ada 2012 mode for the unit to which it applies, regardless of the mode set by the command line switches. -This mode is set automatically for the @code{Ada} and @code{System} +This mode is set automatically for the @cite{Ada} and @cite{System} packages and their children, so you need not specify it in these contexts. This pragma is useful when writing a reusable component that itself uses Ada 2012 features, but which is intended to be usable from @@ -1310,42 +1468,44 @@ extra subprograms marked this way from generating ambiguities in otherwise legal pre-Ada_2012 programs. The one argument form is intended for exclusive use in the GNAT run-time library. -@node Pragma Ada_2012 -@unnumberedsec Pragma Ada_2012 -@findex Ada_2005 -@noindent +@node Pragma Ada_2012,Pragma Allow_Integer_Address,Pragma Ada_12,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-ada-2012}@anchor{22} +@section Pragma Ada_2012 + + Syntax: -@smallexample @c ada + +@example pragma Ada_2012; -@end smallexample +@end example -@noindent This configuration pragma is a synonym for pragma Ada_12 and has the same syntax and effect. -@node Pragma Allow_Integer_Address -@unnumberedsec Pragma Allow_Integer_Address -@findex Allow_Integer_Address -@noindent +@node Pragma Allow_Integer_Address,Pragma Annotate,Pragma Ada_2012,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-allow-integer-address}@anchor{23} +@section Pragma Allow_Integer_Address + + Syntax: -@smallexample @c ada + +@example pragma Allow_Integer_Address; -@end smallexample +@end example -@noindent -In almost all versions of GNAT, @code{System.Address} is a private +In almost all versions of GNAT, @cite{System.Address} is a private type in accordance with the implementation advice in the RM. This means that integer values, in particular integer literals, are not allowed as address values. If the configuration pragma -@code{Allow_Integer_Address} is given, then integer expressions may -be used anywhere a value of type @code{System.Address} is required. +@cite{Allow_Integer_Address} is given, then integer expressions may +be used anywhere a value of type @cite{System.Address} is required. The effect is to introduce an implicit unchecked conversion from the -integer value to type @code{System.Address}. The reverse case of using +integer value to type @cite{System.Address}. The reverse case of using an address where an integer type is required is handled analogously. The following example compiles without errors: -@smallexample @c ada +@example pragma Allow_Integer_Address; with System; use System; package AddrAsInt is @@ -1363,101 +1523,99 @@ package AddrAsInt is Z : Integer; for Z'Address use RR; end AddrAsInt; -@end smallexample - -@noindent -Note that pragma @code{Allow_Integer_Address} is ignored if -@code{System.Address} -is not a private type. In implementations of @code{GNAT} where -System.Address is a visible integer type (notably the implementations -for @code{OpenVMS}), this pragma serves no purpose but is ignored +@end example + +Note that pragma @cite{Allow_Integer_Address} is ignored if @cite{System.Address} +is not a private type. In implementations of @cite{GNAT} where +System.Address is a visible integer type, +this pragma serves no purpose but is ignored rather than rejected to allow common sets of sources to be used in the two situations. -@node Pragma Annotate -@unnumberedsec Pragma Annotate -@findex Annotate -@noindent +@node Pragma Annotate,Pragma Assert,Pragma Allow_Integer_Address,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-annotate}@anchor{24} +@section Pragma Annotate + + Syntax: -@smallexample @c ada + +@example pragma Annotate (IDENTIFIER [, IDENTIFIER @{, ARG@}] [, entity => local_NAME]); ARG ::= NAME | EXPRESSION -@end smallexample +@end example -@noindent -This pragma is used to annotate programs. @var{identifier} identifies +This pragma is used to annotate programs. @cite{identifier} identifies the type of annotation. GNAT verifies that it is an identifier, but does not otherwise analyze it. The second optional identifier is also left unanalyzed, and by convention is used to control the action of the tool to -which the annotation is addressed. The remaining @var{arg} arguments +which the annotation is addressed. The remaining @cite{arg} arguments can be either string literals or more generally expressions. String literals are assumed to be either of type -@code{Standard.String} or else @code{Wide_String} or @code{Wide_Wide_String} +@cite{Standard.String} or else @cite{Wide_String} or @cite{Wide_Wide_String} depending on the character literals they contain. All other kinds of arguments are analyzed as expressions, and must be unambiguous. The last argument if present must have the identifier -@code{Entity} and GNAT verifies that a local name is given. +@cite{Entity} and GNAT verifies that a local name is given. The analyzed pragma is retained in the tree, but not otherwise processed by any part of the GNAT compiler, except to generate corresponding note lines in the generated ALI file. For the format of these note lines, see the compiler source file lib-writ.ads. This pragma is intended for use by -external tools, including ASIS@. The use of pragma Annotate does not +external tools, including ASIS. The use of pragma Annotate does not affect the compilation process in any way. This pragma may be used as a configuration pragma. -@node Pragma Assert -@unnumberedsec Pragma Assert -@findex Assert -@noindent +@node Pragma Assert,Pragma Assert_And_Cut,Pragma Annotate,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-assert}@anchor{25} +@section Pragma Assert + + Syntax: -@smallexample @c ada + +@example pragma Assert ( boolean_EXPRESSION [, string_EXPRESSION]); -@end smallexample +@end example -@noindent The effect of this pragma depends on whether the corresponding command line switch is set to activate assertions. The pragma expands into code equivalent to the following: -@smallexample @c ada +@example if assertions-enabled then if not boolean_EXPRESSION then System.Assertions.Raise_Assert_Failure (string_EXPRESSION); end if; end if; -@end smallexample +@end example -@noindent The string argument, if given, is the message that will be associated with the exception occurrence if the exception is raised. If no second -argument is given, the default message is @samp{@var{file}:@var{nnn}}, -where @var{file} is the name of the source file containing the assert, -and @var{nnn} is the line number of the assert. A pragma is not a +argument is given, the default message is @cite{file}:@cite{nnn}, +where @cite{file} is the name of the source file containing the assert, +and @cite{nnn} is the line number of the assert. A pragma is not a statement, so if a statement sequence contains nothing but a pragma assert, then a null statement is required in addition, as in: -@smallexample @c ada -@dots{} +@example +... if J > 3 then pragma Assert (K > 3, "Bad value for K"); null; end if; -@end smallexample +@end example -@noindent -Note that, as with the @code{if} statement to which it is equivalent, the -type of the expression is either @code{Standard.Boolean}, or any type derived +Note that, as with the @cite{if} statement to which it is equivalent, the +type of the expression is either @cite{Standard.Boolean}, or any type derived from this standard type. Assert checks can be either checked or ignored. By default they are ignored. -They will be checked if either the command line switch @option{-gnata} is -used, or if an @code{Assertion_Policy} or @code{Check_Policy} pragma is used -to enable @code{Assert_Checks}. +They will be checked if either the command line switch @emph{-gnata} is +used, or if an @cite{Assertion_Policy} or @cite{Check_Policy} pragma is used +to enable @cite{Assert_Checks}. If assertions are ignored, then there is no run-time effect (and in particular, any side effects from the @@ -1466,8 +1624,8 @@ analyzed at compile time, and may cause types to be frozen if they are mentioned here for the first time). If assertions are checked, then the given expression is tested, and if -it is @code{False} then @code{System.Assertions.Raise_Assert_Failure} is called -which results in the raising of @code{Assert_Failure} with the given message. +it is @cite{False} then @cite{System.Assertions.Raise_Assert_Failure} is called +which results in the raising of @cite{Assert_Failure} with the given message. You should generally avoid side effects in the expression arguments of this pragma, because these side effects will turn on and off with the @@ -1476,29 +1634,30 @@ effect on the program. However, the expressions are analyzed for semantic correctness whether or not assertions are enabled, so turning assertions on and off cannot affect the legality of a program. -Note that the implementation defined policy @code{DISABLE}, given in a -pragma @code{Assertion_Policy}, can be used to suppress this semantic analysis. +Note that the implementation defined policy @cite{DISABLE}, given in a +pragma @cite{Assertion_Policy}, can be used to suppress this semantic analysis. Note: this is a standard language-defined pragma in versions of Ada from 2005 on. In GNAT, it is implemented in all versions of Ada, and the DISABLE policy is an implementation-defined addition. -@node Pragma Assert_And_Cut -@unnumberedsec Pragma Assert_And_Cut -@findex Assert_And_Cut -@noindent +@node Pragma Assert_And_Cut,Pragma Assertion_Policy,Pragma Assert,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-assert-and-cut}@anchor{26} +@section Pragma Assert_And_Cut + + Syntax: -@smallexample @c ada + +@example pragma Assert_And_Cut ( boolean_EXPRESSION [, string_EXPRESSION]); -@end smallexample +@end example -@noindent -The effect of this pragma is identical to that of pragma @code{Assert}, -except that in an @code{Assertion_Policy} pragma, the identifier -@code{Assert_And_Cut} is used to control whether it is ignored or checked +The effect of this pragma is identical to that of pragma @cite{Assert}, +except that in an @cite{Assertion_Policy} pragma, the identifier +@cite{Assert_And_Cut} is used to control whether it is ignored or checked (or disabled). The intention is that this be used within a subprogram when the @@ -1510,12 +1669,14 @@ a subprogram into sections for the purposes of testing or formal verification. The pragma also serves as useful documentation. -@node Pragma Assertion_Policy -@unnumberedsec Pragma Assertion_Policy -@findex Assertion_Policy -@noindent +@node Pragma Assertion_Policy,Pragma Assume,Pragma Assert_And_Cut,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-assertion-policy}@anchor{27} +@section Pragma Assertion_Policy + + Syntax: -@smallexample @c ada + +@example pragma Assertion_Policy (CHECK | DISABLE | IGNORE); pragma Assertion_Policy ( @@ -1550,61 +1711,61 @@ ID_ASSERTION_KIND ::= Assertions | Statement_Assertions POLICY_IDENTIFIER ::= Check | Disable | Ignore -@end smallexample +@end example -@noindent This is a standard Ada 2012 pragma that is available as an implementation-defined pragma in earlier versions of Ada. -The assertion kinds @code{RM_ASSERTION_KIND} are those defined in -the Ada standard. The assertion kinds @code{ID_ASSERTION_KIND} +The assertion kinds @cite{RM_ASSERTION_KIND} are those defined in +the Ada standard. The assertion kinds @cite{ID_ASSERTION_KIND} are implementation defined additions recognized by the GNAT compiler. The pragma applies in both cases to pragmas and aspects with matching -names, e.g. @code{Pre} applies to the Pre aspect, and @code{Precondition} -applies to both the @code{Precondition} pragma -and the aspect @code{Precondition}. Note that the identifiers for +names, e.g. @cite{Pre} applies to the Pre aspect, and @cite{Precondition} +applies to both the @cite{Precondition} pragma +and the aspect @cite{Precondition}. Note that the identifiers for pragmas Pre_Class and Post_Class are Pre'Class and Post'Class (not Pre_Class and Post_Class), since these pragmas are intended to be identical to the corresponding aspects). -If the policy is @code{CHECK}, then assertions are enabled, i.e. +If the policy is @cite{CHECK}, then assertions are enabled, i.e. the corresponding pragma or aspect is activated. -If the policy is @code{IGNORE}, then assertions are ignored, i.e. +If the policy is @cite{IGNORE}, then assertions are ignored, i.e. the corresponding pragma or aspect is deactivated. -This pragma overrides the effect of the @option{-gnata} switch on the +This pragma overrides the effect of the @emph{-gnata} switch on the command line. -The implementation defined policy @code{DISABLE} is like -@code{IGNORE} except that it completely disables semantic +The implementation defined policy @cite{DISABLE} is like +@cite{IGNORE} except that it completely disables semantic checking of the corresponding pragma or aspect. This is useful when the pragma or aspect argument references subprograms in a with'ed package which is replaced by a dummy package for the final build. -The implementation defined assertion kind @code{Assertions} applies to all +The implementation defined assertion kind @cite{Assertions} applies to all assertion kinds. The form with no assertion kind given implies this choice, so it applies to all assertion kinds (RM defined, and implementation defined). -The implementation defined assertion kind @code{Statement_Assertions} -applies to @code{Assert}, @code{Assert_And_Cut}, -@code{Assume}, @code{Loop_Invariant}, and @code{Loop_Variant}. +The implementation defined assertion kind @cite{Statement_Assertions} +applies to @cite{Assert}, @cite{Assert_And_Cut}, +@cite{Assume}, @cite{Loop_Invariant}, and @cite{Loop_Variant}. + +@node Pragma Assume,Pragma Assume_No_Invalid_Values,Pragma Assertion_Policy,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-assume}@anchor{28} +@section Pragma Assume + -@node Pragma Assume -@unnumberedsec Pragma Assume -@findex Assume -@noindent Syntax: -@smallexample @c ada + +@example pragma Assume ( boolean_EXPRESSION [, string_EXPRESSION]); -@end smallexample +@end example -@noindent -The effect of this pragma is identical to that of pragma @code{Assert}, -except that in an @code{Assertion_Policy} pragma, the identifier -@code{Assume} is used to control whether it is ignored or checked +The effect of this pragma is identical to that of pragma @cite{Assert}, +except that in an @cite{Assertion_Policy} pragma, the identifier +@cite{Assume} is used to control whether it is ignored or checked (or disabled). The intention is that this be used for assumptions about the @@ -1612,30 +1773,32 @@ external environment. So you cannot expect to verify formally or informally that the condition is met, this must be established by examining things outside the program itself. For example, we may have code that depends on the size of -@code{Long_Long_Integer} being at least 64. So we could write: +@cite{Long_Long_Integer} being at least 64. So we could write: -@smallexample @c ada +@example pragma Assume (Long_Long_Integer'Size >= 64); -@end smallexample +@end example -@noindent This assumption cannot be proved from the program itself, but it acts as a useful run-time check that the assumption is met, and documents the need to ensure that it is met by reference to information outside the program. -@node Pragma Assume_No_Invalid_Values -@unnumberedsec Pragma Assume_No_Invalid_Values -@findex Assume_No_Invalid_Values -@cindex Invalid representations -@cindex Invalid values -@noindent +@node Pragma Assume_No_Invalid_Values,Pragma Async_Readers,Pragma Assume,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-assume-no-invalid-values}@anchor{29} +@section Pragma Assume_No_Invalid_Values + + +@geindex Invalid representations + +@geindex Invalid values + Syntax: -@smallexample @c ada + +@example pragma Assume_No_Invalid_Values (On | Off); -@end smallexample +@end example -@noindent This is a configuration pragma that controls the assumptions made by the compiler about the occurrence of invalid representations (invalid values) in the code. @@ -1644,25 +1807,24 @@ The default behavior (corresponding to an Off argument for this pragma), is to assume that values may in general be invalid unless the compiler can prove they are valid. Consider the following example: -@smallexample @c ada +@example V1 : Integer range 1 .. 10; V2 : Integer range 11 .. 20; ... for J in V2 .. V1 loop ... end loop; -@end smallexample +@end example -@noindent if V1 and V2 have valid values, then the loop is known at compile time not to execute since the lower bound must be greater than the upper bound. However in default mode, no such assumption is made, -and the loop may execute. If @code{Assume_No_Invalid_Values (On)} +and the loop may execute. If @cite{Assume_No_Invalid_Values (On)} is given, the compiler will assume that any occurrence of a variable -other than in an explicit @code{'Valid} test always has a valid +other than in an explicit @cite{'Valid} test always has a valid value, and the loop above will be optimized away. -The use of @code{Assume_No_Invalid_Values (On)} is appropriate if +The use of @cite{Assume_No_Invalid_Values (On)} is appropriate if you know your code is free of uninitialized variables and other possible sources of invalid representations, and may result in more efficient code. A program that accesses an invalid representation @@ -1675,114 +1837,104 @@ values will generally give an exception, though formally the program is erroneous so there are no guarantees that this will always be the case, and it is recommended that these two options not be used together. -@node Pragma Async_Readers -@unnumberedsec Pragma Async_Readers -@findex Async_Readers -@noindent +@node Pragma Async_Readers,Pragma Async_Writers,Pragma Assume_No_Invalid_Values,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-async-readers}@anchor{2a} +@section Pragma Async_Readers + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.1.2. -@node Pragma Async_Writers -@unnumberedsec Pragma Async_Writers -@findex Async_Writers -@noindent +@node Pragma Async_Writers,Pragma Attribute_Definition,Pragma Async_Readers,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-async-writers}@anchor{2b} +@section Pragma Async_Writers + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.1.2. -@node Pragma AST_Entry -@unnumberedsec Pragma AST_Entry -@cindex OpenVMS -@findex AST_Entry -@noindent -Syntax: -@smallexample @c ada -pragma AST_Entry (entry_IDENTIFIER); -@end smallexample - -@noindent -This pragma is implemented only in the OpenVMS implementation of GNAT@. The -argument is the simple name of a single entry; at most one @code{AST_Entry} -pragma is allowed for any given entry. This pragma must be used in -conjunction with the @code{AST_Entry} attribute, and is only allowed after -the entry declaration and in the same task type specification or single task -as the entry to which it applies. This pragma specifies that the given entry -may be used to handle an OpenVMS asynchronous system trap (@code{AST}) -resulting from an OpenVMS system service call. The pragma does not affect -normal use of the entry. For further details on this pragma, see the -DEC Ada Language Reference Manual, section 9.12a. - -@node Pragma Attribute_Definition -@unnumberedsec Pragma Attribute_Definition -@findex Attribute_Definition -@noindent +@node Pragma Attribute_Definition,Pragma C_Pass_By_Copy,Pragma Async_Writers,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-attribute-definition}@anchor{2c} +@section Pragma Attribute_Definition + + Syntax: -@smallexample @c ada + +@example pragma Attribute_Definition ([Attribute =>] ATTRIBUTE_DESIGNATOR, [Entity =>] LOCAL_NAME, [Expression =>] EXPRESSION | NAME); -@end smallexample +@end example -@noindent -If @code{Attribute} is a known attribute name, this pragma is equivalent to +If @cite{Attribute} is a known attribute name, this pragma is equivalent to the attribute definition clause: -@smallexample @c ada - for Entity'Attribute use Expression; -@end smallexample +@example +for Entity'Attribute use Expression; +@end example -If @code{Attribute} is not a recognized attribute name, the pragma is +If @cite{Attribute} is not a recognized attribute name, the pragma is ignored, and a warning is emitted. This allows source code to be written that takes advantage of some new attribute, while remaining compilable with earlier compilers. -@node Pragma C_Pass_By_Copy -@unnumberedsec Pragma C_Pass_By_Copy -@cindex Passing by copy -@findex C_Pass_By_Copy -@noindent +@node Pragma C_Pass_By_Copy,Pragma Check,Pragma Attribute_Definition,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-c-pass-by-copy}@anchor{2d} +@section Pragma C_Pass_By_Copy + + +@geindex Passing by copy + Syntax: -@smallexample @c ada + +@example pragma C_Pass_By_Copy ([Max_Size =>] static_integer_EXPRESSION); -@end smallexample +@end example -@noindent Normally the default mechanism for passing C convention records to C convention subprograms is to pass them by reference, as suggested by RM -B.3(69). Use the configuration pragma @code{C_Pass_By_Copy} to change +B.3(69). Use the configuration pragma @cite{C_Pass_By_Copy} to change this default, by requiring that record formal parameters be passed by copy if all of the following conditions are met: -@itemize @bullet -@item + +@itemize * + +@item The size of the record type does not exceed the value specified for -@code{Max_Size}. -@item -The record type has @code{Convention C}. -@item +@cite{Max_Size}. + +@item +The record type has @cite{Convention C}. + +@item The formal parameter has this record type, and the subprogram has a foreign (non-Ada) convention. @end itemize -@noindent -If these conditions are met the argument is passed by copy, i.e.@: in a +If these conditions are met the argument is passed by copy; i.e., in a manner consistent with what C expects if the corresponding formal in the C prototype is a struct (rather than a pointer to a struct). You can also pass records by copy by specifying the convention -@code{C_Pass_By_Copy} for the record type, or by using the extended -@code{Import} and @code{Export} pragmas, which allow specification of +@cite{C_Pass_By_Copy} for the record type, or by using the extended +@cite{Import} and @cite{Export} pragmas, which allow specification of passing mechanisms on a parameter by parameter basis. -@node Pragma Check -@unnumberedsec Pragma Check -@cindex Assertions -@cindex Named assertions -@findex Check -@noindent +@node Pragma Check,Pragma Check_Float_Overflow,Pragma C_Pass_By_Copy,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-check}@anchor{2e} +@section Pragma Check + + +@geindex Assertions + +@geindex Named assertions + Syntax: -@smallexample @c ada + +@example pragma Check ( [Name =>] CHECK_KIND, [Check =>] Boolean_EXPRESSION @@ -1793,37 +1945,38 @@ CHECK_KIND ::= IDENTIFIER | Post'Class | Type_Invariant'Class | Invariant'Class -@end smallexample +@end example -@noindent -This pragma is similar to the predefined pragma @code{Assert} except that an +This pragma is similar to the predefined pragma @cite{Assert} except that an extra identifier argument is present. In conjunction with pragma -@code{Check_Policy}, this can be used to define groups of assertions that can -be independently controlled. The identifier @code{Assertion} is special, it -refers to the normal set of pragma @code{Assert} statements. +@cite{Check_Policy}, this can be used to define groups of assertions that can +be independently controlled. The identifier @cite{Assertion} is special, it +refers to the normal set of pragma @cite{Assert} statements. Checks introduced by this pragma are normally deactivated by default. They can -be activated either by the command line option @option{-gnata}, which turns on -all checks, or individually controlled using pragma @code{Check_Policy}. +be activated either by the command line option @emph{-gnata}, which turns on +all checks, or individually controlled using pragma @cite{Check_Policy}. -The identifiers @code{Assertions} and @code{Statement_Assertions} are not +The identifiers @cite{Assertions} and @cite{Statement_Assertions} are not permitted as check kinds, since this would cause confusion with the use -of these identifiers in @code{Assertion_Policy} and @code{Check_Policy} +of these identifiers in @cite{Assertion_Policy} and @cite{Check_Policy} pragmas, where they are used to refer to sets of assertions. -@node Pragma Check_Float_Overflow -@unnumberedsec Pragma Check_Float_Overflow -@cindex Floating-point overflow -@findex Check_Float_Overflow -@noindent +@node Pragma Check_Float_Overflow,Pragma Check_Name,Pragma Check,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-check-float-overflow}@anchor{2f} +@section Pragma Check_Float_Overflow + + +@geindex Floating-point overflow + Syntax: -@smallexample @c ada + +@example pragma Check_Float_Overflow; -@end smallexample +@end example -@noindent -In Ada, the predefined floating-point types (@code{Short_Float}, -@code{Float}, @code{Long_Float}, @code{Long_Long_Float}) are +In Ada, the predefined floating-point types (@cite{Short_Float}, +@cite{Float}, @cite{Long_Float}, @cite{Long_Long_Float}) are defined to be @emph{unconstrained}. This means that even though each has a well-defined base range, an operation that delivers a result outside this base range is not required to raise an exception. @@ -1840,44 +1993,47 @@ This can be accomplished by defining your own constrained floating-point subtype range constraints -- and indeed such a subtype can have the same base range as its base type. For example: -@smallexample @c ada +@example subtype My_Float is Float range Float'Range; -@end smallexample +@end example -@noindent -Here @code{My_Float} has the same range as -@code{Float} but is constrained, so operations on -@code{My_Float} values will be checked for overflow +Here @cite{My_Float} has the same range as +@cite{Float} but is constrained, so operations on +@cite{My_Float} values will be checked for overflow against this range. This style will achieve the desired goal, but it is often more convenient to be able to simply use the standard predefined floating-point types as long as overflow checking could be guaranteed. -The @code{Check_Float_Overflow} +The @cite{Check_Float_Overflow} configuration pragma achieves this effect. If a unit is compiled subject to this configuration pragma, then all operations on predefined floating-point types including operations on base types of these floating-point types will be treated as though those types were constrained, and overflow checks -will be generated. The @code{Constraint_Error} +will be generated. The @cite{Constraint_Error} exception is raised if the result is out of range. This mode can also be set by use of the compiler -switch @option{-gnateF}. - -@node Pragma Check_Name -@unnumberedsec Pragma Check_Name -@cindex Defining check names -@cindex Check names, defining -@findex Check_Name -@noindent +switch @emph{-gnateF}. + +@node Pragma Check_Name,Pragma Check_Policy,Pragma Check_Float_Overflow,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-check-name}@anchor{30} +@section Pragma Check_Name + + +@geindex Defining check names + +@geindex Check names +@geindex defining + Syntax: -@smallexample @c ada + +@example pragma Check_Name (check_name_IDENTIFIER); -@end smallexample +@end example -@noindent This is a configuration pragma that defines a new implementation defined check name (unless IDENTIFIER matches one of the predefined check names, in which case the pragma has no effect). Check names @@ -1886,28 +2042,35 @@ are present in a partition mentioning the same name, only one new check name is introduced. An implementation defined check name introduced with this pragma may -be used in only three contexts: @code{pragma Suppress}, -@code{pragma Unsuppress}, -and as the prefix of a @code{Check_Name'Enabled} attribute reference. For +be used in only three contexts: @cite{pragma Suppress}, +@cite{pragma Unsuppress}, +and as the prefix of a @cite{Check_Name'Enabled} attribute reference. For any of these three cases, the check name must be visible. A check name is visible if it is in the configuration pragmas applying to the current unit, or if it appears at the start of any unit that is part of the dependency set of the current unit (e.g., units that -are mentioned in @code{with} clauses). +are mentioned in @cite{with} clauses). Check names introduced by this pragma are subject to control by compiler switches (in particular -gnatp) in the usual manner. -@node Pragma Check_Policy -@unnumberedsec Pragma Check_Policy -@cindex Controlling assertions -@cindex Assertions, control -@cindex Check pragma control -@cindex Named assertions -@findex Check -@noindent +@node Pragma Check_Policy,Pragma CIL_Constructor,Pragma Check_Name,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-check-policy}@anchor{31} +@section Pragma Check_Policy + + +@geindex Controlling assertions + +@geindex Assertions +@geindex control + +@geindex Check pragma control + +@geindex Named assertions + Syntax: -@smallexample @c ada + +@example pragma Check_Policy ([Name =>] CHECK_KIND, [Policy =>] POLICY_IDENTIFIER); @@ -1928,95 +2091,94 @@ The identifiers Name and Policy are not allowed as CHECK_KIND values. This avoids confusion between the two possible syntax forms for this pragma. POLICY_IDENTIFIER ::= ON | OFF | CHECK | DISABLE | IGNORE -@end smallexample +@end example -@noindent This pragma is used to set the checking policy for assertions (specified -by aspects or pragmas), the @code{Debug} pragma, or additional checks -to be checked using the @code{Check} pragma. It may appear either as +by aspects or pragmas), the @cite{Debug} pragma, or additional checks +to be checked using the @cite{Check} pragma. It may appear either as a configuration pragma, or within a declarative part of package. In the latter case, it applies from the point where it appears to the end of -the declarative region (like pragma @code{Suppress}). +the declarative region (like pragma @cite{Suppress}). -The @code{Check_Policy} pragma is similar to the -predefined @code{Assertion_Policy} pragma, +The @cite{Check_Policy} pragma is similar to the +predefined @cite{Assertion_Policy} pragma, and if the check kind corresponds to one of the assertion kinds that -are allowed by @code{Assertion_Policy}, then the effect is identical. +are allowed by @cite{Assertion_Policy}, then the effect is identical. If the first argument is Debug, then the policy applies to Debug pragmas, -disabling their effect if the policy is @code{OFF}, @code{DISABLE}, or -@code{IGNORE}, and allowing them to execute with normal semantics if -the policy is @code{ON} or @code{CHECK}. In addition if the policy is -@code{DISABLE}, then the procedure call in @code{Debug} pragmas will +disabling their effect if the policy is @cite{OFF}, @cite{DISABLE}, or +@cite{IGNORE}, and allowing them to execute with normal semantics if +the policy is @cite{ON} or @cite{CHECK}. In addition if the policy is +@cite{DISABLE}, then the procedure call in @cite{Debug} pragmas will be totally ignored and not analyzed semantically. Finally the first argument may be some other identifier than the above possibilities, in which case it controls a set of named assertions -that can be checked using pragma @code{Check}. For example, if the pragma: +that can be checked using pragma @cite{Check}. For example, if the pragma: -@smallexample @c ada +@example pragma Check_Policy (Critical_Error, OFF); -@end smallexample +@end example -@noindent -is given, then subsequent @code{Check} pragmas whose first argument is also -@code{Critical_Error} will be disabled. +is given, then subsequent @cite{Check} pragmas whose first argument is also +@cite{Critical_Error} will be disabled. -The check policy is @code{OFF} to turn off corresponding checks, and @code{ON} +The check policy is @cite{OFF} to turn off corresponding checks, and @cite{ON} to turn on corresponding checks. The default for a set of checks for which no -@code{Check_Policy} is given is @code{OFF} unless the compiler switch -@option{-gnata} is given, which turns on all checks by default. - -The check policy settings @code{CHECK} and @code{IGNORE} are recognized -as synonyms for @code{ON} and @code{OFF}. These synonyms are provided for -compatibility with the standard @code{Assertion_Policy} pragma. The check -policy setting @code{DISABLE} causes the second argument of a corresponding -@code{Check} pragma to be completely ignored and not analyzed. - -@node Pragma CIL_Constructor -@unnumberedsec Pragma CIL_Constructor -@findex CIL_Constructor -@noindent +@cite{Check_Policy} is given is @cite{OFF} unless the compiler switch +@emph{-gnata} is given, which turns on all checks by default. + +The check policy settings @cite{CHECK} and @cite{IGNORE} are recognized +as synonyms for @cite{ON} and @cite{OFF}. These synonyms are provided for +compatibility with the standard @cite{Assertion_Policy} pragma. The check +policy setting @cite{DISABLE} causes the second argument of a corresponding +@cite{Check} pragma to be completely ignored and not analyzed. + +@node Pragma CIL_Constructor,Pragma Comment,Pragma Check_Policy,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-cil-constructor}@anchor{32} +@section Pragma CIL_Constructor + + Syntax: -@smallexample @c ada +@example pragma CIL_Constructor ([Entity =>] function_LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma is used to assert that the specified Ada function should be mapped to the .NET constructor for some Ada tagged record type. See section 4.1 of the -@code{GNAT User's Guide: Supplement for the .NET Platform.} +@cite{GNAT User's Guide: Supplement for the .NET Platform.} for related information. -@node Pragma Comment -@unnumberedsec Pragma Comment -@findex Comment -@noindent +@node Pragma Comment,Pragma Common_Object,Pragma CIL_Constructor,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-comment}@anchor{33} +@section Pragma Comment + + Syntax: -@smallexample @c ada +@example pragma Comment (static_string_EXPRESSION); -@end smallexample +@end example -@noindent -This is almost identical in effect to pragma @code{Ident}. It allows the +This is almost identical in effect to pragma @cite{Ident}. It allows the placement of a comment into the object file and hence into the executable file if the operating system permits such usage. The -difference is that @code{Comment}, unlike @code{Ident}, has +difference is that @cite{Comment}, unlike @cite{Ident}, has no limitations on placement of the pragma (it can be placed anywhere in the main source unit), and if more than one pragma is used, all comments are retained. -@node Pragma Common_Object -@unnumberedsec Pragma Common_Object -@findex Common_Object -@noindent +@node Pragma Common_Object,Pragma Compile_Time_Error,Pragma Comment,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-common-object}@anchor{34} +@section Pragma Common_Object + + Syntax: -@smallexample @c ada +@example pragma Common_Object ( [Internal =>] LOCAL_NAME [, [External =>] EXTERNAL_SYMBOL] @@ -2025,35 +2187,34 @@ pragma Common_Object ( EXTERNAL_SYMBOL ::= IDENTIFIER | static_string_EXPRESSION -@end smallexample +@end example -@noindent This pragma enables the shared use of variables stored in overlaid -linker areas corresponding to the use of @code{COMMON} +linker areas corresponding to the use of @cite{COMMON} in Fortran. The single -object @var{LOCAL_NAME} is assigned to the area designated by -the @var{External} argument. +object @cite{LOCAL_NAME} is assigned to the area designated by +the @cite{External} argument. You may define a record to correspond to a series -of fields. The @var{Size} argument +of fields. The @cite{Size} argument is syntax checked in GNAT, but otherwise ignored. -@code{Common_Object} is not supported on all platforms. If no +@cite{Common_Object} is not supported on all platforms. If no support is available, then the code generator will issue a message indicating that the necessary attribute for implementation of this pragma is not available. -@node Pragma Compile_Time_Error -@unnumberedsec Pragma Compile_Time_Error -@findex Compile_Time_Error -@noindent +@node Pragma Compile_Time_Error,Pragma Compile_Time_Warning,Pragma Common_Object,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-compile-time-error}@anchor{35} +@section Pragma Compile_Time_Error + + Syntax: -@smallexample @c ada +@example pragma Compile_Time_Error (boolean_EXPRESSION, static_string_EXPRESSION); -@end smallexample +@end example -@noindent This pragma can be used to generate additional compile time error messages. It is particularly useful in generics, where errors can be issued for @@ -2069,18 +2230,18 @@ If these conditions are met, an error message is generated using the value given as the second argument. This string value may contain embedded ASCII.LF characters to break the message into multiple lines. -@node Pragma Compile_Time_Warning -@unnumberedsec Pragma Compile_Time_Warning -@findex Compile_Time_Warning -@noindent +@node Pragma Compile_Time_Warning,Pragma Compiler_Unit,Pragma Compile_Time_Error,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-compile-time-warning}@anchor{36} +@section Pragma Compile_Time_Warning + + Syntax: -@smallexample @c ada +@example pragma Compile_Time_Warning (boolean_EXPRESSION, static_string_EXPRESSION); -@end smallexample +@end example -@noindent Same as pragma Compile_Time_Error, except a warning is issued instead of an error message. Note that if this pragma is used in a package that is with'ed by a client, the client will get the warning even though it @@ -2092,32 +2253,32 @@ of formal parameters are tested, and warnings given appropriately. Another use with a first parameter of True is to warn a client about use of a package, for example that it is not fully implemented. -@node Pragma Compiler_Unit -@unnumberedsec Pragma Compiler_Unit -@findex Compiler_Unit -@noindent +@node Pragma Compiler_Unit,Pragma Compiler_Unit_Warning,Pragma Compile_Time_Warning,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-compiler-unit}@anchor{37} +@section Pragma Compiler_Unit + + Syntax: -@smallexample @c ada +@example pragma Compiler_Unit; -@end smallexample +@end example -@noindent This pragma is obsolete. It is equivalent to Compiler_Unit_Warning. It is retained so that old versions of the GNAT run-time that use this pragma can be compiled with newer versions of the compiler. -@node Pragma Compiler_Unit_Warning -@unnumberedsec Pragma Compiler_Unit_Warning -@findex Compiler_Unit_Warning -@noindent +@node Pragma Compiler_Unit_Warning,Pragma Complete_Representation,Pragma Compiler_Unit,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-compiler-unit-warning}@anchor{38} +@section Pragma Compiler_Unit_Warning + + Syntax: -@smallexample @c ada +@example pragma Compiler_Unit_Warning; -@end smallexample +@end example -@noindent This pragma is intended only for internal use in the GNAT run-time library. It indicates that the unit is used as part of the compiler build. The effect is to generate warnings for the use of constructs (for example, conditional @@ -2125,17 +2286,17 @@ expressions) that would cause trouble when bootstrapping using an older version of GNAT. For the exact list of restrictions, see the compiler sources and references to Check_Compiler_Unit. -@node Pragma Complete_Representation -@unnumberedsec Pragma Complete_Representation -@findex Complete_Representation -@noindent +@node Pragma Complete_Representation,Pragma Complex_Representation,Pragma Compiler_Unit_Warning,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-complete-representation}@anchor{39} +@section Pragma Complete_Representation + + Syntax: -@smallexample @c ada +@example pragma Complete_Representation; -@end smallexample +@end example -@noindent This pragma must appear immediately within a record representation clause. Typical placements are before the first component clause or after the last component clause. The effect is to give an error @@ -2144,19 +2305,19 @@ may be used to ensure that a record representation clause is complete, and that this invariant is maintained if fields are added to the record in the future. -@node Pragma Complex_Representation -@unnumberedsec Pragma Complex_Representation -@findex Complex_Representation -@noindent +@node Pragma Complex_Representation,Pragma Component_Alignment,Pragma Complete_Representation,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-complex-representation}@anchor{3a} +@section Pragma Complex_Representation + + Syntax: -@smallexample @c ada +@example pragma Complex_Representation ([Entity =>] LOCAL_NAME); -@end smallexample +@end example -@noindent -The @var{Entity} argument must be the name of a record type which has +The @cite{Entity} argument must be the name of a record type which has two fields of the same floating-point type. The effect of this pragma is to force gcc to use the special internal complex representation form for this record, which may be more efficient. Note that this may result in @@ -2166,14 +2327,18 @@ example, in some environments, there is a requirement for passing records by pointer, and the use of this pragma may result in passing this type in floating-point registers. -@node Pragma Component_Alignment -@unnumberedsec Pragma Component_Alignment -@cindex Alignments of components -@findex Component_Alignment -@noindent +@node Pragma Component_Alignment,Pragma Contract_Cases,Pragma Complex_Representation,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-component-alignment}@anchor{3b} +@section Pragma Component_Alignment + + +@geindex Alignments of components + +@geindex Pragma Component_Alignment + Syntax: -@smallexample @c ada +@example pragma Component_Alignment ( [Form =>] ALIGNMENT_CHOICE [, [Name =>] type_LOCAL_NAME]); @@ -2183,55 +2348,64 @@ ALIGNMENT_CHOICE ::= | Component_Size_4 | Storage_Unit | Default -@end smallexample +@end example -@noindent Specifies the alignment of components in array or record types. -The meaning of the @var{Form} argument is as follows: +The meaning of the @cite{Form} argument is as follows: + +@quotation + +@geindex Component_Size (in pragma Component_Alignment) +@end quotation + + +@table @asis + +@item @emph{Component_Size} -@table @code -@findex Component_Size -@item Component_Size Aligns scalar components and subcomponents of the array or record type on boundaries appropriate to their inherent size (naturally aligned). For example, 1-byte components are aligned on byte boundaries, 2-byte integer components are aligned on 2-byte boundaries, 4-byte integer components are aligned on 4-byte boundaries and so on. These alignment rules correspond to the normal rules for C compilers on all -machines except the VAX@. +machines except the VAX. + +@geindex Component_Size_4 (in pragma Component_Alignment) + +@item @emph{Component_Size_4} -@findex Component_Size_4 -@item Component_Size_4 Naturally aligns components with a size of four or fewer bytes. Components that are larger than 4 bytes are placed on the next 4-byte boundary. -@findex Storage_Unit -@item Storage_Unit -Specifies that array or record components are byte aligned, i.e.@: +@geindex Storage_Unit (in pragma Component_Alignment) + +@item @emph{Storage_Unit} + +Specifies that array or record components are byte aligned, i.e., aligned on boundaries determined by the value of the constant -@code{System.Storage_Unit}. +@cite{System.Storage_Unit}. + +@geindex Default (in pragma Component_Alignment) + +@item @emph{Default} -@cindex OpenVMS -@item Default Specifies that array or record components are aligned on default boundaries, appropriate to the underlying hardware or operating system or -both. For OpenVMS VAX systems, the @code{Default} choice is the same as -the @code{Storage_Unit} choice (byte alignment). For all other systems, -the @code{Default} choice is the same as @code{Component_Size} (natural +both. The @cite{Default} choice is the same as @cite{Component_Size} (natural alignment). @end table -@noindent -If the @code{Name} parameter is present, @var{type_LOCAL_NAME} must +If the @cite{Name} parameter is present, @cite{type_LOCAL_NAME} must refer to a local record or array type, and the specified alignment choice applies to the specified type. The use of -@code{Component_Alignment} together with a pragma @code{Pack} causes the -@code{Component_Alignment} pragma to be ignored. The use of -@code{Component_Alignment} together with a record representation clause +@cite{Component_Alignment} together with a pragma @cite{Pack} causes the +@cite{Component_Alignment} pragma to be ignored. The use of +@cite{Component_Alignment} together with a record representation clause is only effective for fields not specified by the representation clause. -If the @code{Name} parameter is absent, the pragma can be used as either +If the @cite{Name} parameter is absent, the pragma can be used as either a configuration pragma, in which case it applies to one or more units in accordance with the normal rules for configuration pragmas, or it can be used within a declarative part, in which case it applies to types that @@ -2241,76 +2415,75 @@ to be applied to any record or array type which has otherwise standard representation. If the alignment for a record or array type is not specified (using -pragma @code{Pack}, pragma @code{Component_Alignment}, or a record rep +pragma @cite{Pack}, pragma @cite{Component_Alignment}, or a record rep clause), the GNAT uses the default alignment as described previously. -@node Pragma Contract_Cases -@unnumberedsec Pragma Contract_Cases -@cindex Contract cases -@findex Contract_Cases -@noindent +@node Pragma Contract_Cases,Pragma Convention_Identifier,Pragma Component_Alignment,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-contract-cases}@anchor{3c} +@section Pragma Contract_Cases + + +@geindex Contract cases + Syntax: -@smallexample @c ada +@example pragma Contract_Cases ( Condition => Consequence @{,Condition => Consequence@}); -@end smallexample +@end example -@noindent -The @code{Contract_Cases} pragma allows defining fine-grain specifications +The @cite{Contract_Cases} pragma allows defining fine-grain specifications that can complement or replace the contract given by a precondition and a -postcondition. Additionally, the @code{Contract_Cases} pragma can be used +postcondition. Additionally, the @cite{Contract_Cases} pragma can be used by testing and formal verification tools. The compiler checks its validity and, depending on the assertion policy at the point of declaration of the pragma, it may insert a check in the executable. For code generation, the contract cases -@smallexample @c ada +@example pragma Contract_Cases ( Cond1 => Pred1, Cond2 => Pred2); -@end smallexample +@end example -@noindent are equivalent to -@smallexample @c ada +@example C1 : constant Boolean := Cond1; -- evaluated at subprogram entry C2 : constant Boolean := Cond2; -- evaluated at subprogram entry pragma Precondition ((C1 and not C2) or (C2 and not C1)); pragma Postcondition (if C1 then Pred1); pragma Postcondition (if C2 then Pred2); -@end smallexample +@end example -@noindent The precondition ensures that one and only one of the conditions is satisfied on entry to the subprogram. The postcondition ensures that for the condition that was True on entry, the corrresponding consequence is True on exit. Other consequence expressions are not evaluated. -A precondition @code{P} and postcondition @code{Q} can also be +A precondition @cite{P} and postcondition @cite{Q} can also be expressed as contract cases: -@smallexample @c ada +@example pragma Contract_Cases (P => Q); -@end smallexample +@end example -The placement and visibility rules for @code{Contract_Cases} pragmas are +The placement and visibility rules for @cite{Contract_Cases} pragmas are identical to those described for preconditions and postconditions. The compiler checks that boolean expressions given in conditions and consequences are valid, where the rules for conditions are the same as -the rule for an expression in @code{Precondition} and the rules for +the rule for an expression in @cite{Precondition} and the rules for consequences are the same as the rule for an expression in -@code{Postcondition}. In particular, attributes @code{'Old} and -@code{'Result} can only be used within consequence expressions. -The condition for the last contract case may be @code{others}, to denote +@cite{Postcondition}. In particular, attributes @cite{'Old} and +@cite{'Result} can only be used within consequence expressions. +The condition for the last contract case may be @cite{others}, to denote any case not captured by the previous cases. The following is an example of use within a package spec: -@smallexample @c ada +@example package Math_Functions is ... function Sqrt (Arg : Float) return Float; @@ -2319,133 +2492,134 @@ package Math_Functions is others => Sqrt'Result = 0); ... end Math_Functions; -@end smallexample +@end example -@noindent The meaning of contract cases is that only one case should apply at each call, as determined by the corresponding condition evaluating to True, and that the consequence for this case should hold when the subprogram returns. -@node Pragma Convention_Identifier -@unnumberedsec Pragma Convention_Identifier -@findex Convention_Identifier -@cindex Conventions, synonyms -@noindent +@node Pragma Convention_Identifier,Pragma CPP_Class,Pragma Contract_Cases,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-convention-identifier}@anchor{3d} +@section Pragma Convention_Identifier + + +@geindex Conventions +@geindex synonyms + Syntax: -@smallexample @c ada +@example pragma Convention_Identifier ( [Name =>] IDENTIFIER, [Convention =>] convention_IDENTIFIER); -@end smallexample +@end example -@noindent This pragma provides a mechanism for supplying synonyms for existing -convention identifiers. The @code{Name} identifier can subsequently +convention identifiers. The @cite{Name} identifier can subsequently be used as a synonym for the given convention in other pragmas (including -for example pragma @code{Import} or another @code{Convention_Identifier} +for example pragma @cite{Import} or another @cite{Convention_Identifier} pragma). As an example of the use of this, suppose you had legacy code which used Fortran77 as the identifier for Fortran. Then the pragma: -@smallexample @c ada +@example pragma Convention_Identifier (Fortran77, Fortran); -@end smallexample +@end example -@noindent -would allow the use of the convention identifier @code{Fortran77} in +would allow the use of the convention identifier @cite{Fortran77} in subsequent code, avoiding the need to modify the sources. As another example, you could use this to parameterize convention requirements -according to systems. Suppose you needed to use @code{Stdcall} on -windows systems, and @code{C} on some other system, then you could -define a convention identifier @code{Library} and use a single -@code{Convention_Identifier} pragma to specify which convention +according to systems. Suppose you needed to use @cite{Stdcall} on +windows systems, and @cite{C} on some other system, then you could +define a convention identifier @cite{Library} and use a single +@cite{Convention_Identifier} pragma to specify which convention would be used system-wide. -@node Pragma CPP_Class -@unnumberedsec Pragma CPP_Class -@findex CPP_Class -@cindex Interfacing with C++ -@noindent +@node Pragma CPP_Class,Pragma CPP_Constructor,Pragma Convention_Identifier,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-cpp-class}@anchor{3e} +@section Pragma CPP_Class + + +@geindex Interfacing with C++ + Syntax: -@smallexample @c ada +@example pragma CPP_Class ([Entity =>] LOCAL_NAME); -@end smallexample +@end example -@noindent The argument denotes an entity in the current declarative region that is declared as a record type. It indicates that the type corresponds to an externally declared C++ class type, and is to be laid out the same way that C++ would lay out the type. If the C++ class has virtual primitives then the record must be declared as a tagged record type. -Types for which @code{CPP_Class} is specified do not have assignment or +Types for which @cite{CPP_Class} is specified do not have assignment or equality operators defined (such operations can be imported or declared as subprograms as required). Initialization is allowed only by constructor -functions (see pragma @code{CPP_Constructor}). Such types are implicitly +functions (see pragma @cite{CPP_Constructor}). Such types are implicitly limited if not explicitly declared as limited or derived from a limited type, and an error is issued in that case. -See @ref{Interfacing to C++} for related information. +See @ref{3f,,Interfacing to C++} for related information. -Note: Pragma @code{CPP_Class} is currently obsolete. It is supported +Note: Pragma @cite{CPP_Class} is currently obsolete. It is supported for backward compatibility but its functionality is available -using pragma @code{Import} with @code{Convention} = @code{CPP}. +using pragma @cite{Import} with @cite{Convention} = @cite{CPP}. + +@node Pragma CPP_Constructor,Pragma CPP_Virtual,Pragma CPP_Class,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-cpp-constructor}@anchor{40} +@section Pragma CPP_Constructor + + +@geindex Interfacing with C++ -@node Pragma CPP_Constructor -@unnumberedsec Pragma CPP_Constructor -@cindex Interfacing with C++ -@findex CPP_Constructor -@noindent Syntax: -@smallexample @c ada +@example pragma CPP_Constructor ([Entity =>] LOCAL_NAME [, [External_Name =>] static_string_EXPRESSION ] [, [Link_Name =>] static_string_EXPRESSION ]); -@end smallexample +@end example -@noindent This pragma identifies an imported function (imported in the usual way -with pragma @code{Import}) as corresponding to a C++ constructor. If -@code{External_Name} and @code{Link_Name} are not specified then the -@code{Entity} argument is a name that must have been previously mentioned -in a pragma @code{Import} with @code{Convention} = @code{CPP}. Such name +with pragma @cite{Import}) as corresponding to a C++ constructor. If +@cite{External_Name} and @cite{Link_Name} are not specified then the +@cite{Entity} argument is a name that must have been previously mentioned +in a pragma @cite{Import} with @cite{Convention} = @cite{CPP}. Such name must be of one of the following forms: -@itemize @bullet -@item -@code{function @var{Fname} return @var{T}} -@itemize @bullet -@item -@code{function @var{Fname} return @var{T}'Class} +@itemize * -@item -@code{function @var{Fname} (@dots{}) return @var{T}} -@end itemize +@item +@strong{function} @cite{Fname} @strong{return} T` -@item -@code{function @var{Fname} (@dots{}) return @var{T}'Class} +@item +@strong{function} @cite{Fname} @strong{return} T'Class + +@item +@strong{function} @cite{Fname} (...) @strong{return} T` + +@item +@strong{function} @cite{Fname} (...) @strong{return} T'Class @end itemize -@noindent -where @var{T} is a limited record type imported from C++ with pragma -@code{Import} and @code{Convention} = @code{CPP}. +where @cite{T} is a limited record type imported from C++ with pragma +@cite{Import} and @cite{Convention} = @cite{CPP}. The first two forms import the default constructor, used when an object -of type @var{T} is created on the Ada side with no explicit constructor. +of type @cite{T} is created on the Ada side with no explicit constructor. The latter two forms cover all the non-default constructors of the type. -See the @value{EDITION} User's Guide for details. +See the GNAT User's Guide for details. If no constructors are imported, it is impossible to create any objects on the Ada side and the type is implicitly declared abstract. -Pragma @code{CPP_Constructor} is intended primarily for automatic generation -using an automatic binding generator tool (such as the @code{-fdump-ada-spec} +Pragma @cite{CPP_Constructor} is intended primarily for automatic generation +using an automatic binding generator tool (such as the @cite{-fdump-ada-spec} GCC switch). -See @ref{Interfacing to C++} for more related information. +See @ref{3f,,Interfacing to C++} for more related information. Note: The use of functions returning class-wide types for constructors is currently obsolete. They are supported for backward compatibility. The @@ -2453,11 +2627,13 @@ use of functions returning the type T leave the Ada sources more clear because the imported C++ constructors always return an object of type T; that is, they never return an object whose type is a descendant of type T. -@node Pragma CPP_Virtual -@unnumberedsec Pragma CPP_Virtual -@cindex Interfacing to C++ -@findex CPP_Virtual -@noindent +@node Pragma CPP_Virtual,Pragma CPP_Vtable,Pragma CPP_Constructor,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-cpp-virtual}@anchor{41} +@section Pragma CPP_Virtual + + +@geindex Interfacing to C++ + This pragma is now obsolete and, other than generating a warning if warnings on obsolescent features are enabled, is completely ignored. It is retained for compatibility @@ -2465,51 +2641,53 @@ purposes. It used to be required to ensure compoatibility with C++, but is no longer required for that purpose because GNAT generates the same object layout as the G++ compiler by default. -See @ref{Interfacing to C++} for related information. +See @ref{3f,,Interfacing to C++} for related information. + +@node Pragma CPP_Vtable,Pragma CPU,Pragma CPP_Virtual,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-cpp-vtable}@anchor{42} +@section Pragma CPP_Vtable + + +@geindex Interfacing with C++ -@node Pragma CPP_Vtable -@unnumberedsec Pragma CPP_Vtable -@cindex Interfacing with C++ -@findex CPP_Vtable -@noindent This pragma is now obsolete and, other than generating a warning if warnings on obsolescent features are enabled, is completely ignored. It used to be required to ensure compatibility with C++, but is no longer required for that purpose because GNAT generates the same object layout as the G++ compiler by default. -See @ref{Interfacing to C++} for related information. +See @ref{3f,,Interfacing to C++} for related information. + +@node Pragma CPU,Pragma Debug,Pragma CPP_Vtable,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-cpu}@anchor{43} +@section Pragma CPU + -@node Pragma CPU -@unnumberedsec Pragma CPU -@findex CPU -@noindent Syntax: -@smallexample @c ada +@example pragma CPU (EXPRESSION); -@end smallexample +@end example -@noindent This pragma is standard in Ada 2012, but is available in all earlier versions of Ada as an implementation-defined pragma. See Ada 2012 Reference Manual for details. -@node Pragma Debug -@unnumberedsec Pragma Debug -@findex Debug -@noindent +@node Pragma Debug,Pragma Debug_Policy,Pragma CPU,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-debug}@anchor{44} +@section Pragma Debug + + Syntax: -@smallexample @c ada +@example pragma Debug ([CONDITION, ]PROCEDURE_CALL_WITHOUT_SEMICOLON); PROCEDURE_CALL_WITHOUT_SEMICOLON ::= PROCEDURE_NAME | PROCEDURE_PREFIX ACTUAL_PARAMETER_PART -@end smallexample +@end example -@noindent The procedure call argument has the syntactic form of an expression, meeting the syntactic requirements for pragmas. @@ -2517,58 +2695,52 @@ If debug pragmas are not enabled or if the condition is present and evaluates to False, this pragma has no effect. If debug pragmas are enabled, the semantics of the pragma is exactly equivalent to the procedure call statement corresponding to the argument with a terminating semicolon. Pragmas are -permitted in sequences of declarations, so you can use pragma @code{Debug} to +permitted in sequences of declarations, so you can use pragma @cite{Debug} to intersperse calls to debug procedures in the middle of declarations. Debug -pragmas can be enabled either by use of the command line switch @option{-gnata} -or by use of the pragma @code{Check_Policy} with a first argument of -@code{Debug}. - -@node Pragma Debug_Policy -@unnumberedsec Pragma Debug_Policy -@findex Debug_Policy -@noindent +pragmas can be enabled either by use of the command line switch @emph{-gnata} +or by use of the pragma @cite{Check_Policy} with a first argument of +@cite{Debug}. + +@node Pragma Debug_Policy,Pragma Default_Scalar_Storage_Order,Pragma Debug,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-debug-policy}@anchor{45} +@section Pragma Debug_Policy + + Syntax: -@smallexample @c ada +@example pragma Debug_Policy (CHECK | DISABLE | IGNORE | ON | OFF); -@end smallexample +@end example -@noindent -This pragma is equivalent to a corresponding @code{Check_Policy} pragma -with a first argument of @code{Debug}. It is retained for historical +This pragma is equivalent to a corresponding @cite{Check_Policy} pragma +with a first argument of @cite{Debug}. It is retained for historical compatibility reasons. -@node Pragma Default_Scalar_Storage_Order -@unnumberedsec Pragma Default_Scalar_Storage_Order -@cindex Default_Scalar_Storage_Order -@cindex Scalar_Storage_Order -@findex Default_Scalar_Storage_Order -@noindent +@node Pragma Default_Scalar_Storage_Order,Pragma Default_Storage_Pool,Pragma Debug_Policy,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-default-scalar-storage-order}@anchor{46} +@section Pragma Default_Scalar_Storage_Order + + +@geindex Default_Scalar_Storage_Order + +@geindex Scalar_Storage_Order + Syntax: -@smallexample @c ada +@example pragma Default_Scalar_Storage_Order (High_Order_First | Low_Order_First); -@end smallexample - -@noindent -Normally if no explicit @code{Scalar_Storage_Order} is given for a record -type or array type, then the scalar storage order defaults to the native -order for the target. However, this default may be overridden using -this pragma (except for derived tagged types, which always default to -inheriting the scalar storage order of their parent). The pragma may -appear as a configuration pragma, or locally within a package spec or -declarative part. In the latter case, it applies to all subsequent -types declared within that package spec or declarative part. +@end example -If this pragma is used as a configuration pragma which appears within a -configuration pragma file (as opposed to appearing explicitly at the start -of a single unit), then the binder will require that all units in a partition -be compiled in a similar manner, other than run-time units, which are not -affected by this pragma. +Normally if no explicit @cite{Scalar_Storage_Order} is given for a record +type or array type, then the scalar storage order defaults to the ordinary +default for the target. But this default may be overridden using this pragma. +The pragma may appear as a configuration pragma, or locally within a package +spec or declarative part. In the latter case, it applies to all subsequent +types declared within that package spec or declarative part. The following example shows the use of this pragma: -@smallexample @c ada +@example pragma Default_Scalar_Storage_Order (High_Order_First); with System; use System; package DSSO1 is @@ -2601,49 +2773,58 @@ package DSSO1 is a : Integer; end record; end DSSO1; -@end smallexample +@end example -@noindent -In this example record types L.. have @code{Low_Order_First} scalar -storage order, and record types H.. have @code{High_Order_First}. -Note that in the case of @code{H4a}, the order is not inherited -from the parent type. Only an explicitly set @code{Scalar_Storage_Order} +In this example record types L.. have @cite{Low_Order_First} scalar +storage order, and record types H.. have @cite{High_Order_First}. +Note that in the case of @cite{H4a}, the order is not inherited +from the parent type. Only an explicitly set @cite{Scalar_Storage_Order} gets inherited on type derivation. -@node Pragma Default_Storage_Pool -@unnumberedsec Pragma Default_Storage_Pool -@cindex Default_Storage_Pool -@findex Default_Storage_Pool -@noindent +If this pragma is used as a configuration pragma which appears within a +configuration pragma file (as opposed to appearing explicitly at the start +of a single unit), then the binder will require that all units in a partition +be compiled in a similar manner, other than run-time units, which are not +affected by this pragma. Note that the use of this form is discouraged because +it may significantly degrade the run-time performance of the software, instead +the default scalar storage order ought to be changed only on a local basis. + +@node Pragma Default_Storage_Pool,Pragma Depends,Pragma Default_Scalar_Storage_Order,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-default-storage-pool}@anchor{47} +@section Pragma Default_Storage_Pool + + +@geindex Default_Storage_Pool + Syntax: -@smallexample @c ada +@example pragma Default_Storage_Pool (storage_pool_NAME | null); -@end smallexample +@end example -@noindent This pragma is standard in Ada 2012, but is available in all earlier versions of Ada as an implementation-defined pragma. See Ada 2012 Reference Manual for details. -@node Pragma Depends -@unnumberedsec Pragma Depends -@findex Depends -@noindent +@node Pragma Depends,Pragma Detect_Blocking,Pragma Default_Storage_Pool,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-depends}@anchor{48} +@section Pragma Depends + + For the description of this pragma, see SPARK 2014 Reference Manual, section 6.1.5. -@node Pragma Detect_Blocking -@unnumberedsec Pragma Detect_Blocking -@findex Detect_Blocking -@noindent +@node Pragma Detect_Blocking,Pragma Disable_Atomic_Synchronization,Pragma Depends,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-detect-blocking}@anchor{49} +@section Pragma Detect_Blocking + + Syntax: -@smallexample @c ada +@example pragma Detect_Blocking; -@end smallexample +@end example -@noindent This is a standard pragma in Ada 2005, that is available in all earlier versions of Ada as an implementation-defined pragma. @@ -2651,18 +2832,19 @@ This is a configuration pragma that forces the detection of potentially blocking operations within a protected operation, and to raise Program_Error if that happens. -@node Pragma Disable_Atomic_Synchronization -@unnumberedsec Pragma Disable_Atomic_Synchronization -@cindex Atomic Synchronization -@findex Disable_Atomic_Synchronization -@noindent +@node Pragma Disable_Atomic_Synchronization,Pragma Dispatching_Domain,Pragma Detect_Blocking,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-disable-atomic-synchronization}@anchor{4a} +@section Pragma Disable_Atomic_Synchronization + + +@geindex Atomic Synchronization + Syntax: -@smallexample @c ada +@example pragma Disable_Atomic_Synchronization [(Entity)]; -@end smallexample +@end example -@noindent Ada requires that accesses (reads or writes) of an atomic variable be regarded as synchronization points in the case of multiple tasks. Particularly in the case of multi-processors this may require special @@ -2671,106 +2853,109 @@ be turned off using this pragma in cases where it is known not to be required. The placement and scope rules for this pragma are the same as those -for @code{pragma Suppress}. In particular it can be used as a +for @cite{pragma Suppress}. In particular it can be used as a configuration pragma, or in a declaration sequence where it applies -till the end of the scope. If an @code{Entity} argument is present, +till the end of the scope. If an @cite{Entity} argument is present, the action applies only to that entity. -@node Pragma Dispatching_Domain -@unnumberedsec Pragma Dispatching_Domain -@findex Dispatching_Domain -@noindent +@node Pragma Dispatching_Domain,Pragma Effective_Reads,Pragma Disable_Atomic_Synchronization,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-dispatching-domain}@anchor{4b} +@section Pragma Dispatching_Domain + + Syntax: -@smallexample @c ada +@example pragma Dispatching_Domain (EXPRESSION); -@end smallexample +@end example -@noindent This pragma is standard in Ada 2012, but is available in all earlier versions of Ada as an implementation-defined pragma. See Ada 2012 Reference Manual for details. -@node Pragma Effective_Reads -@unnumberedsec Pragma Effective_Reads -@findex Effective_Reads -@noindent +@node Pragma Effective_Reads,Pragma Effective_Writes,Pragma Dispatching_Domain,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-effective-reads}@anchor{4c} +@section Pragma Effective_Reads + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.1.2. -@node Pragma Effective_Writes -@unnumberedsec Pragma Effective_Writes -@findex Effective_Writes -@noindent +@node Pragma Effective_Writes,Pragma Elaboration_Checks,Pragma Effective_Reads,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-effective-writes}@anchor{4d} +@section Pragma Effective_Writes + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.1.2. -@node Pragma Elaboration_Checks -@unnumberedsec Pragma Elaboration_Checks -@cindex Elaboration control -@findex Elaboration_Checks -@noindent +@node Pragma Elaboration_Checks,Pragma Eliminate,Pragma Effective_Writes,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-elaboration-checks}@anchor{4e} +@section Pragma Elaboration_Checks + + +@geindex Elaboration control + Syntax: -@smallexample @c ada +@example pragma Elaboration_Checks (Dynamic | Static); -@end smallexample +@end example -@noindent This is a configuration pragma that provides control over the elaboration model used by the compilation affected by the -pragma. If the parameter is @code{Dynamic}, +pragma. If the parameter is @cite{Dynamic}, then the dynamic elaboration model described in the Ada Reference Manual is used, as though -the @option{-gnatE} switch had been specified on the command -line. If the parameter is @code{Static}, then the default GNAT static +the @emph{-gnatE} switch had been specified on the command +line. If the parameter is @cite{Static}, then the default GNAT static model is used. This configuration pragma overrides the setting of the command line. For full details on the elaboration models -used by the GNAT compiler, see @ref{Elaboration Order Handling in GNAT,,, -gnat_ugn, @value{EDITION} User's Guide}. - -@node Pragma Eliminate -@unnumberedsec Pragma Eliminate -@cindex Elimination of unused subprograms -@findex Eliminate -@noindent +used by the GNAT compiler, see the chapter on elaboration order handling +in the @emph{GNAT User's Guide}. + +@node Pragma Eliminate,Pragma Enable_Atomic_Synchronization,Pragma Elaboration_Checks,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-eliminate}@anchor{4f} +@section Pragma Eliminate + + +@geindex Elimination of unused subprograms + Syntax: -@smallexample @c ada +@example pragma Eliminate ([Entity =>] DEFINING_DESIGNATOR, [Source_Location =>] STRING_LITERAL); -@end smallexample +@end example -@noindent The string literal given for the source location is a string which specifies the line number of the occurrence of the entity, using the syntax for SOURCE_TRACE given below: -@smallexample @c ada - SOURCE_TRACE ::= SOURCE_REFERENCE [LBRACKET SOURCE_TRACE RBRACKET] +@example +SOURCE_TRACE ::= SOURCE_REFERENCE [LBRACKET SOURCE_TRACE RBRACKET] - LBRACKET ::= [ - RBRACKET ::= ] +LBRACKET ::= [ +RBRACKET ::= ] - SOURCE_REFERENCE ::= FILE_NAME : LINE_NUMBER +SOURCE_REFERENCE ::= FILE_NAME : LINE_NUMBER - LINE_NUMBER ::= DIGIT @{DIGIT@} -@end smallexample +LINE_NUMBER ::= DIGIT @{DIGIT@} +@end example -@noindent -Spaces around the colon in a @code{Source_Reference} are optional. +Spaces around the colon in a @cite{Source_Reference} are optional. -The @code{DEFINING_DESIGNATOR} matches the defining designator used in an -explicit subprogram declaration, where the @code{entity} name in this +The @cite{DEFINING_DESIGNATOR} matches the defining designator used in an +explicit subprogram declaration, where the @cite{entity} name in this designator appears on the source line specified by the source location. -The source trace that is given as the @code{Source_Location} shall obey the -following rules. The @code{FILE_NAME} is the short name (with no directory +The source trace that is given as the @cite{Source_Location} shall obey the +following rules. The @cite{FILE_NAME} is the short name (with no directory information) of an Ada source file, given using exactly the required syntax for the underlying file system (e.g. case is important if the underlying -operating system is case sensitive). @code{LINE_NUMBER} gives the line -number of the occurrence of the @code{entity} -as a decimal literal without an exponent or point. If an @code{entity} is not +operating system is case sensitive). @cite{LINE_NUMBER} gives the line +number of the occurrence of the @cite{entity} +as a decimal literal without an exponent or point. If an @cite{entity} is not declared in a generic instantiation (this includes generic subprogram instances), the source trace includes only one source reference. If an entity is declared inside a generic instantiation, its source trace (when parsing @@ -2784,7 +2969,7 @@ nested) instantiation in the code of the corresponding generic unit, and so on, and the leftmost element (that is out of any square brackets) is the location of the declaration of the entity to eliminate in a generic unit. -Note that the @code{Source_Location} argument specifies which of a set of +Note that the @cite{Source_Location} argument specifies which of a set of similarly named entities is being eliminated, dealing both with overloading, and also appearance of the same entity name in different scopes. @@ -2793,84 +2978,58 @@ compiled and built. The effect of the pragma is to allow the compiler to eliminate the code or data associated with the named entity. Any reference to an eliminated entity causes a compile-time or link-time error. -The intention of pragma @code{Eliminate} is to allow a program to be compiled +The intention of pragma @cite{Eliminate} is to allow a program to be compiled in a system-independent manner, with unused entities eliminated, without needing to modify the source text. Normally the required set of -@code{Eliminate} pragmas is constructed automatically using the gnatelim tool. +@cite{Eliminate} pragmas is constructed automatically using the gnatelim tool. Any source file change that removes, splits, or adds lines may make the set of Eliminate pragmas invalid because their -@code{Source_Location} argument values may get out of date. +@cite{Source_Location} argument values may get out of date. -Pragma @code{Eliminate} may be used where the referenced entity is a dispatching +Pragma @cite{Eliminate} may be used where the referenced entity is a dispatching operation. In this case all the subprograms to which the given operation can dispatch are considered to be unused (are never called as a result of a direct or a dispatching call). -@node Pragma Enable_Atomic_Synchronization -@unnumberedsec Pragma Enable_Atomic_Synchronization -@cindex Atomic Synchronization -@findex Enable_Atomic_Synchronization -@noindent +@node Pragma Enable_Atomic_Synchronization,Pragma Export_Function,Pragma Eliminate,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-enable-atomic-synchronization}@anchor{50} +@section Pragma Enable_Atomic_Synchronization + + +@geindex Atomic Synchronization + Syntax: -@smallexample @c ada +@example pragma Enable_Atomic_Synchronization [(Entity)]; -@end smallexample +@end example -@noindent Ada requires that accesses (reads or writes) of an atomic variable be regarded as synchronization points in the case of multiple tasks. Particularly in the case of multi-processors this may require special handling, e.g. the generation of memory barriers. This synchronization is performed by default, but can be turned off using -@code{pragma Disable_Atomic_Synchronization}. The -@code{Enable_Atomic_Synchronization} pragma can be used to turn +@cite{pragma Disable_Atomic_Synchronization}. The +@cite{Enable_Atomic_Synchronization} pragma can be used to turn it back on. The placement and scope rules for this pragma are the same as those -for @code{pragma Unsuppress}. In particular it can be used as a +for @cite{pragma Unsuppress}. In particular it can be used as a configuration pragma, or in a declaration sequence where it applies -till the end of the scope. If an @code{Entity} argument is present, +till the end of the scope. If an @cite{Entity} argument is present, the action applies only to that entity. -@node Pragma Export_Exception -@unnumberedsec Pragma Export_Exception -@cindex OpenVMS -@findex Export_Exception -@noindent -Syntax: +@node Pragma Export_Function,Pragma Export_Object,Pragma Enable_Atomic_Synchronization,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-export-function}@anchor{51} +@section Pragma Export_Function -@smallexample @c ada -pragma Export_Exception ( - [Internal =>] LOCAL_NAME - [, [External =>] EXTERNAL_SYMBOL] - [, [Form =>] Ada | VMS] - [, [Code =>] static_integer_EXPRESSION]); -EXTERNAL_SYMBOL ::= - IDENTIFIER -| static_string_EXPRESSION -@end smallexample - -@noindent -This pragma is implemented only in the OpenVMS implementation of GNAT@. It -causes the specified exception to be propagated outside of the Ada program, -so that it can be handled by programs written in other OpenVMS languages. -This pragma establishes an external name for an Ada exception and makes the -name available to the OpenVMS Linker as a global symbol. For further details -on this pragma, see the -DEC Ada Language Reference Manual, section 13.9a3.2. - -@node Pragma Export_Function -@unnumberedsec Pragma Export_Function -@cindex Argument passing mechanisms -@findex Export_Function - -@noindent +@geindex Argument passing mechanisms + Syntax: -@smallexample @c ada +@example pragma Export_Function ( [Internal =>] LOCAL_NAME [, [External =>] EXTERNAL_SYMBOL] @@ -2900,46 +3059,44 @@ MECHANISM_ASSOCIATION ::= [formal_parameter_NAME =>] MECHANISM_NAME MECHANISM_NAME ::= Value | Reference -@end smallexample +@end example -@noindent Use this pragma to make a function externally callable and optionally provide information on mechanisms to be used for passing parameter and result values. We recommend, for the purposes of improving portability, this pragma always be used in conjunction with a separate pragma -@code{Export}, which must precede the pragma @code{Export_Function}. -GNAT does not require a separate pragma @code{Export}, but if none is -present, @code{Convention Ada} is assumed, which is usually +@cite{Export}, which must precede the pragma @cite{Export_Function}. +GNAT does not require a separate pragma @cite{Export}, but if none is +present, @cite{Convention Ada} is assumed, which is usually not what is wanted, so it is usually appropriate to use this -pragma in conjunction with a @code{Export} or @code{Convention} +pragma in conjunction with a @cite{Export} or @cite{Convention} pragma that specifies the desired foreign convention. -Pragma @code{Export_Function} -(and @code{Export}, if present) must appear in the same declarative +Pragma @cite{Export_Function} +(and @cite{Export}, if present) must appear in the same declarative region as the function to which they apply. -@var{internal_name} must uniquely designate the function to which the +@cite{internal_name} must uniquely designate the function to which the pragma applies. If more than one function name exists of this name in -the declarative part you must use the @code{Parameter_Types} and -@code{Result_Type} parameters is mandatory to achieve the required -unique designation. @var{subtype_mark}s in these parameters must -exactly match the subtypes in the corresponding function specification, -using positional notation to match parameters with subtype marks. -The form with an @code{'Access} attribute can be used to match an +the declarative part you must use the @cite{Parameter_Types} and +@cite{Result_Type} parameters is mandatory to achieve the required +unique designation. @cite{subtype_mark`s in these parameters must exactly match the subtypes in the corresponding function specification@comma{} using positional notation to match parameters with subtype marks. The form with an `'Access} attribute can be used to match an anonymous access parameter. -@cindex Suppressing external name +@geindex Suppressing external name + Special treatment is given if the EXTERNAL is an explicit null string or a static string expressions that evaluates to the null string. In this case, no external name is generated. This form still allows the specification of parameter mechanisms. -@node Pragma Export_Object -@unnumberedsec Pragma Export_Object -@findex Export_Object -@noindent +@node Pragma Export_Object,Pragma Export_Procedure,Pragma Export_Function,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-export-object}@anchor{52} +@section Pragma Export_Object + + Syntax: -@smallexample @c ada +@example pragma Export_Object [Internal =>] LOCAL_NAME [, [External =>] EXTERNAL_SYMBOL] @@ -2948,23 +3105,23 @@ pragma Export_Object EXTERNAL_SYMBOL ::= IDENTIFIER | static_string_EXPRESSION -@end smallexample +@end example -@noindent This pragma designates an object as exported, and apart from the extended rules for external symbols, is identical in effect to the use of -the normal @code{Export} pragma applied to an object. You may use a +the normal @cite{Export} pragma applied to an object. You may use a separate Export pragma (and you probably should from the point of view -of portability), but it is not required. @var{Size} is syntax checked, -but otherwise ignored by GNAT@. +of portability), but it is not required. @cite{Size} is syntax checked, +but otherwise ignored by GNAT. + +@node Pragma Export_Procedure,Pragma Export_Value,Pragma Export_Object,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-export-procedure}@anchor{53} +@section Pragma Export_Procedure + -@node Pragma Export_Procedure -@unnumberedsec Pragma Export_Procedure -@findex Export_Procedure -@noindent Syntax: -@smallexample @c ada +@example pragma Export_Procedure ( [Internal =>] LOCAL_NAME [, [External =>] EXTERNAL_SYMBOL] @@ -2992,37 +3149,37 @@ MECHANISM_ASSOCIATION ::= [formal_parameter_NAME =>] MECHANISM_NAME MECHANISM_NAME ::= Value | Reference -@end smallexample +@end example -@noindent -This pragma is identical to @code{Export_Function} except that it +This pragma is identical to @cite{Export_Function} except that it applies to a procedure rather than a function and the parameters -@code{Result_Type} and @code{Result_Mechanism} are not permitted. -GNAT does not require a separate pragma @code{Export}, but if none is -present, @code{Convention Ada} is assumed, which is usually +@cite{Result_Type} and @cite{Result_Mechanism} are not permitted. +GNAT does not require a separate pragma @cite{Export}, but if none is +present, @cite{Convention Ada} is assumed, which is usually not what is wanted, so it is usually appropriate to use this -pragma in conjunction with a @code{Export} or @code{Convention} +pragma in conjunction with a @cite{Export} or @cite{Convention} pragma that specifies the desired foreign convention. -@cindex Suppressing external name +@geindex Suppressing external name + Special treatment is given if the EXTERNAL is an explicit null string or a static string expressions that evaluates to the null string. In this case, no external name is generated. This form still allows the specification of parameter mechanisms. -@node Pragma Export_Value -@unnumberedsec Pragma Export_Value -@findex Export_Value -@noindent +@node Pragma Export_Value,Pragma Export_Valued_Procedure,Pragma Export_Procedure,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-export-value}@anchor{54} +@section Pragma Export_Value + + Syntax: -@smallexample @c ada +@example pragma Export_Value ( [Value =>] static_integer_EXPRESSION, [Link_Name =>] static_string_EXPRESSION); -@end smallexample +@end example -@noindent This pragma serves to export a static integer value for external use. The first argument specifies the value to be exported. The Link_Name argument specifies the symbolic name to be associated with the integer @@ -3031,13 +3188,14 @@ that can be referenced in assembly language units to be linked with the application. This pragma is currently supported only for the AAMP target and is ignored for other targets. -@node Pragma Export_Valued_Procedure -@unnumberedsec Pragma Export_Valued_Procedure -@findex Export_Valued_Procedure -@noindent +@node Pragma Export_Valued_Procedure,Pragma Extend_System,Pragma Export_Value,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-export-valued-procedure}@anchor{55} +@section Pragma Export_Valued_Procedure + + Syntax: -@smallexample @c ada +@example pragma Export_Valued_Procedure ( [Internal =>] LOCAL_NAME [, [External =>] EXTERNAL_SYMBOL] @@ -3065,248 +3223,263 @@ MECHANISM_ASSOCIATION ::= [formal_parameter_NAME =>] MECHANISM_NAME MECHANISM_NAME ::= Value | Reference -@end smallexample +@end example -@noindent -This pragma is identical to @code{Export_Procedure} except that the -first parameter of @var{LOCAL_NAME}, which must be present, must be of -mode @code{OUT}, and externally the subprogram is treated as a function +This pragma is identical to @cite{Export_Procedure} except that the +first parameter of @cite{LOCAL_NAME}, which must be present, must be of +mode @cite{OUT}, and externally the subprogram is treated as a function with this parameter as the result of the function. GNAT provides for -this capability to allow the use of @code{OUT} and @code{IN OUT} +this capability to allow the use of @cite{OUT} and @cite{IN OUT} parameters in interfacing to external functions (which are not permitted in Ada functions). -GNAT does not require a separate pragma @code{Export}, but if none is -present, @code{Convention Ada} is assumed, which is almost certainly +GNAT does not require a separate pragma @cite{Export}, but if none is +present, @cite{Convention Ada} is assumed, which is almost certainly not what is wanted since the whole point of this pragma is to interface with foreign language functions, so it is usually appropriate to use this -pragma in conjunction with a @code{Export} or @code{Convention} +pragma in conjunction with a @cite{Export} or @cite{Convention} pragma that specifies the desired foreign convention. -@cindex Suppressing external name +@geindex Suppressing external name + Special treatment is given if the EXTERNAL is an explicit null string or a static string expressions that evaluates to the null string. In this case, no external name is generated. This form still allows the specification of parameter mechanisms. -@node Pragma Extend_System -@unnumberedsec Pragma Extend_System -@cindex @code{system}, extending -@cindex Dec Ada 83 -@findex Extend_System -@noindent +@node Pragma Extend_System,Pragma Extensions_Allowed,Pragma Export_Valued_Procedure,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-extend-system}@anchor{56} +@section Pragma Extend_System + + +@geindex System +@geindex extending + +@geindex DEC Ada 83 + Syntax: -@smallexample @c ada +@example pragma Extend_System ([Name =>] IDENTIFIER); -@end smallexample +@end example -@noindent This pragma is used to provide backwards compatibility with other -implementations that extend the facilities of package @code{System}. In -GNAT, @code{System} contains only the definitions that are present in -the Ada RM@. However, other implementations, notably the DEC Ada 83 -implementation, provide many extensions to package @code{System}. +implementations that extend the facilities of package @cite{System}. In +GNAT, @cite{System} contains only the definitions that are present in +the Ada RM. However, other implementations, notably the DEC Ada 83 +implementation, provide many extensions to package @cite{System}. For each such implementation accommodated by this pragma, GNAT provides a -package @code{Aux_@var{xxx}}, e.g.@: @code{Aux_DEC} for the DEC Ada 83 +package @cite{Aux_`xxx`}, e.g., @cite{Aux_DEC} for the DEC Ada 83 implementation, which provides the required additional definitions. You -can use this package in two ways. You can @code{with} it in the normal -way and access entities either by selection or using a @code{use} +can use this package in two ways. You can @cite{with} it in the normal +way and access entities either by selection or using a @cite{use} clause. In this case no special processing is required. However, if existing code contains references such as -@code{System.@var{xxx}} where @var{xxx} is an entity in the extended -definitions provided in package @code{System}, you may use this pragma -to extend visibility in @code{System} in a non-standard way that +@cite{System.`xxx`} where @cite{xxx} is an entity in the extended +definitions provided in package @cite{System}, you may use this pragma +to extend visibility in @cite{System} in a non-standard way that provides greater compatibility with the existing code. Pragma -@code{Extend_System} is a configuration pragma whose single argument is +@cite{Extend_System} is a configuration pragma whose single argument is the name of the package containing the extended definition -(e.g.@: @code{Aux_DEC} for the DEC Ada case). A unit compiled under +(e.g., @cite{Aux_DEC} for the DEC Ada case). A unit compiled under control of this pragma will be processed using special visibility -processing that looks in package @code{System.Aux_@var{xxx}} where -@code{Aux_@var{xxx}} is the pragma argument for any entity referenced in -package @code{System}, but not found in package @code{System}. +processing that looks in package @cite{System.Aux_`xxx`} where +@cite{Aux_`xxx`} is the pragma argument for any entity referenced in +package @cite{System}, but not found in package @cite{System}. -You can use this pragma either to access a predefined @code{System} -extension supplied with the compiler, for example @code{Aux_DEC} or +You can use this pragma either to access a predefined @cite{System} +extension supplied with the compiler, for example @cite{Aux_DEC} or you can construct your own extension unit following the above -definition. Note that such a package is a child of @code{System} +definition. Note that such a package is a child of @cite{System} and thus is considered part of the implementation. -To compile it you will have to use the @option{-gnatg} switch, -or the @option{/GNAT_INTERNAL} qualifier on OpenVMS, +To compile it you will have to use the @emph{-gnatg} switch for compiling System units, as explained in the -@value{EDITION} User's Guide. - -@node Pragma Extensions_Allowed -@unnumberedsec Pragma Extensions_Allowed -@cindex Ada Extensions -@cindex GNAT Extensions -@findex Extensions_Allowed -@noindent +GNAT User's Guide. + +@node Pragma Extensions_Allowed,Pragma External,Pragma Extend_System,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-extensions-allowed}@anchor{57} +@section Pragma Extensions_Allowed + + +@geindex Ada Extensions + +@geindex GNAT Extensions + Syntax: -@smallexample @c ada +@example pragma Extensions_Allowed (On | Off); -@end smallexample +@end example -@noindent This configuration pragma enables or disables the implementation extension mode (the use of Off as a parameter cancels the effect -of the @option{-gnatX} command switch). +of the @emph{-gnatX} command switch). In extension mode, the latest version of the Ada language is implemented (currently Ada 2012), and in addition a small number of GNAT specific extensions are recognized as follows: + @table @asis -@item Constrained attribute for generic objects -The @code{Constrained} attribute is permitted for objects of + +@item @emph{Constrained attribute for generic objects} + +The @cite{Constrained} attribute is permitted for objects of generic types. The result indicates if the corresponding actual is constrained. - @end table -@node Pragma External -@unnumberedsec Pragma External -@findex External -@noindent +@node Pragma External,Pragma External_Name_Casing,Pragma Extensions_Allowed,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-external}@anchor{58} +@section Pragma External + + Syntax: -@smallexample @c ada +@example pragma External ( [ Convention =>] convention_IDENTIFIER, [ Entity =>] LOCAL_NAME [, [External_Name =>] static_string_EXPRESSION ] [, [Link_Name =>] static_string_EXPRESSION ]); -@end smallexample +@end example -@noindent This pragma is identical in syntax and semantics to pragma -@code{Export} as defined in the Ada Reference Manual. It is +@cite{Export} as defined in the Ada Reference Manual. It is provided for compatibility with some Ada 83 compilers that used this pragma for exactly the same purposes as pragma -@code{Export} before the latter was standardized. - -@node Pragma External_Name_Casing -@unnumberedsec Pragma External_Name_Casing -@cindex Dec Ada 83 casing compatibility -@cindex External Names, casing -@cindex Casing of External names -@findex External_Name_Casing -@noindent +@cite{Export} before the latter was standardized. + +@node Pragma External_Name_Casing,Pragma Fast_Math,Pragma External,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-external-name-casing}@anchor{59} +@section Pragma External_Name_Casing + + +@geindex Dec Ada 83 casing compatibility + +@geindex External Names +@geindex casing + +@geindex Casing of External names + Syntax: -@smallexample @c ada +@example pragma External_Name_Casing ( Uppercase | Lowercase [, Uppercase | Lowercase | As_Is]); -@end smallexample +@end example -@noindent This pragma provides control over the casing of external names associated with Import and Export pragmas. There are two cases to consider: -@table @asis -@item Implicit external names + +@itemize * + +@item +Implicit external names + Implicit external names are derived from identifiers. The most common case arises when a standard Ada Import or Export pragma is used with only two arguments, as in: -@smallexample @c ada - pragma Import (C, C_Routine); -@end smallexample +@example +pragma Import (C, C_Routine); +@end example -@noindent Since Ada is a case-insensitive language, the spelling of the identifier in the Ada source program does not provide any information on the desired casing of the external name, and so a convention is needed. In GNAT the default treatment is that such names are converted to all lower case letters. This corresponds to the normal C style in many environments. -The first argument of pragma @code{External_Name_Casing} can be used to -control this treatment. If @code{Uppercase} is specified, then the name -will be forced to all uppercase letters. If @code{Lowercase} is specified, +The first argument of pragma @cite{External_Name_Casing} can be used to +control this treatment. If @cite{Uppercase} is specified, then the name +will be forced to all uppercase letters. If @cite{Lowercase} is specified, then the normal default of all lower case letters will be used. This same implicit treatment is also used in the case of extended DEC Ada 83 compatible Import and Export pragmas where an external name is explicitly specified using an identifier rather than a string. -@item Explicit external names +@item +Explicit external names + Explicit external names are given as string literals. The most common case arises when a standard Ada Import or Export pragma is used with three arguments, as in: -@smallexample @c ada +@example pragma Import (C, C_Routine, "C_routine"); -@end smallexample +@end example -@noindent In this case, the string literal normally provides the exact casing required for the external name. The second argument of pragma -@code{External_Name_Casing} may be used to modify this behavior. -If @code{Uppercase} is specified, then the name -will be forced to all uppercase letters. If @code{Lowercase} is specified, +@cite{External_Name_Casing} may be used to modify this behavior. +If @cite{Uppercase} is specified, then the name +will be forced to all uppercase letters. If @cite{Lowercase} is specified, then the name will be forced to all lowercase letters. A specification of -@code{As_Is} provides the normal default behavior in which the casing is +@cite{As_Is} provides the normal default behavior in which the casing is taken from the string provided. -@end table +@end itemize -@noindent This pragma may appear anywhere that a pragma is valid. In particular, it -can be used as a configuration pragma in the @file{gnat.adc} file, in which +can be used as a configuration pragma in the @code{gnat.adc} file, in which case it applies to all subsequent compilations, or it can be used as a program unit pragma, in which case it only applies to the current unit, or it can be used more locally to control individual Import/Export pragmas. -It is primarily intended for use with OpenVMS systems, where many +It was primarily intended for use with OpenVMS systems, where many compilers convert all symbols to upper case by default. For interfacing to -such compilers (e.g.@: the DEC C compiler), it may be convenient to use +such compilers (e.g., the DEC C compiler), it may be convenient to use the pragma: -@smallexample @c ada +@example pragma External_Name_Casing (Uppercase, Uppercase); -@end smallexample +@end example -@noindent to enforce the upper casing of all external symbols. -@node Pragma Fast_Math -@unnumberedsec Pragma Fast_Math -@findex Fast_Math -@noindent +@node Pragma Fast_Math,Pragma Favor_Top_Level,Pragma External_Name_Casing,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-fast-math}@anchor{5a} +@section Pragma Fast_Math + + Syntax: -@smallexample @c ada +@example pragma Fast_Math; -@end smallexample +@end example -@noindent This is a configuration pragma which activates a mode in which speed is considered more important for floating-point operations than absolutely accurate adherence to the requirements of the standard. Currently the following operations are affected: + @table @asis -@item Complex Multiplication + +@item @emph{Complex Multiplication} + The normal simple formula for complex multiplication can result in intermediate overflows for numbers near the end of the range. The Ada standard requires that this situation be detected and corrected by scaling, but in Fast_Math mode such cases will simply result in overflow. Note that to take advantage of this you -must instantiate your own version of @code{Ada.Numerics.Generic_Complex_Types} +must instantiate your own version of @cite{Ada.Numerics.Generic_Complex_Types} under control of the pragma, rather than use the preinstantiated versions. @end table -@node Pragma Favor_Top_Level -@unnumberedsec Pragma Favor_Top_Level -@findex Favor_Top_Level -@noindent +@node Pragma Favor_Top_Level,Pragma Finalize_Storage_Only,Pragma Fast_Math,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-favor-top-level}@anchor{5b} +@section Pragma Favor_Top_Level + + Syntax: -@smallexample @c ada +@example pragma Favor_Top_Level (type_NAME); -@end smallexample +@end example -@noindent The named type must be an access-to-subprogram type. This pragma is an efficiency hint to the compiler, regarding the use of 'Access or 'Unrestricted_Access on nested (non-library-level) subprograms. The @@ -3316,115 +3489,98 @@ top-level case. When this pragma is used, dynamically generated trampolines may be used on some targets for nested subprograms. See also the No_Implicit_Dynamic_Code restriction. -@node Pragma Finalize_Storage_Only -@unnumberedsec Pragma Finalize_Storage_Only -@findex Finalize_Storage_Only -@noindent +@node Pragma Finalize_Storage_Only,Pragma Float_Representation,Pragma Favor_Top_Level,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-finalize-storage-only}@anchor{5c} +@section Pragma Finalize_Storage_Only + + Syntax: -@smallexample @c ada +@example pragma Finalize_Storage_Only (first_subtype_LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma allows the compiler not to emit a Finalize call for objects defined at the library level. This is mostly useful for types where finalization is only used to deal with storage reclamation since in most environments it is not necessary to reclaim memory just before terminating execution, hence the name. -@node Pragma Float_Representation -@unnumberedsec Pragma Float_Representation -@cindex OpenVMS -@findex Float_Representation -@noindent +@node Pragma Float_Representation,Pragma Global,Pragma Finalize_Storage_Only,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-float-representation}@anchor{5d} +@section Pragma Float_Representation + + Syntax: -@smallexample @c ada +@example pragma Float_Representation (FLOAT_REP[, float_type_LOCAL_NAME]); FLOAT_REP ::= VAX_Float | IEEE_Float -@end smallexample +@end example -@noindent In the one argument form, this pragma is a configuration pragma which allows control over the internal representation chosen for the predefined -floating point types declared in the packages @code{Standard} and -@code{System}. On all systems other than OpenVMS, the argument must -be @code{IEEE_Float} and the pragma has no effect. On OpenVMS, the -argument may be @code{VAX_Float} to specify the use of the VAX float -format for the floating-point types in Standard. This requires that -the standard runtime libraries be recompiled. +floating point types declared in the packages @cite{Standard} and +@cite{System}. This pragma is only provided for compatibility and has no effect. The two argument form specifies the representation to be used for -the specified floating-point type. On all systems other than OpenVMS, -the argument must -be @code{IEEE_Float} to specify the use of IEEE format, as follows: +the specified floating-point type. The argument must +be @cite{IEEE_Float} to specify the use of IEEE format, as follows: -@itemize @bullet -@item + +@itemize * + +@item For a digits value of 6, 32-bit IEEE short format will be used. -@item + +@item For a digits value of 15, 64-bit IEEE long format will be used. -@item + +@item No other value of digits is permitted. @end itemize -On OpenVMS, the -argument may be @code{VAX_Float} to specify the use of the VAX float -format, as follows: +@node Pragma Global,Pragma Ident,Pragma Float_Representation,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-global}@anchor{5e} +@section Pragma Global -@itemize @bullet -@item -For digits values up to 6, F float format will be used. -@item -For digits values from 7 to 9, D float format will be used. -@item -For digits values from 10 to 15, G float format will be used. -@item -Digits values above 15 are not allowed. -@end itemize -@node Pragma Global -@unnumberedsec Pragma Global -@findex Global -@noindent For the description of this pragma, see SPARK 2014 Reference Manual, section 6.1.4. -@node Pragma Ident -@unnumberedsec Pragma Ident -@findex Ident -@noindent +@node Pragma Ident,Pragma Implementation_Defined,Pragma Global,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-ident}@anchor{5f} +@section Pragma Ident + + Syntax: -@smallexample @c ada +@example pragma Ident (static_string_EXPRESSION); -@end smallexample +@end example -@noindent -This pragma is identical in effect to pragma @code{Comment}. It is provided +This pragma is identical in effect to pragma @cite{Comment}. It is provided for compatibility with other Ada compilers providing this pragma. -@node Pragma Implementation_Defined -@unnumberedsec Pragma Implementation_Defined -@findex Implementation_Defined -@noindent +@node Pragma Implementation_Defined,Pragma Implemented,Pragma Ident,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-implementation-defined}@anchor{60} +@section Pragma Implementation_Defined + + Syntax: -@smallexample @c ada +@example pragma Implementation_Defined (local_NAME); -@end smallexample +@end example -@noindent This pragma marks a previously declared entioty as implementation-defined. For an overloaded entity, applies to the most recent homonym. -@smallexample @c ada +@example pragma Implementation_Defined; -@end smallexample +@end example -@noindent The form with no arguments appears anywhere within a scope, most typically a package spec, and indicates that all entities that are defined within the package spec are Implementation_Defined. @@ -3434,19 +3590,19 @@ implementation-defined entities introduced in language-defined units, for the purpose of implementing the No_Implementation_Identifiers restriction. -@node Pragma Implemented -@unnumberedsec Pragma Implemented -@findex Implemented -@noindent +@node Pragma Implemented,Pragma Implicit_Packing,Pragma Implementation_Defined,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-implemented}@anchor{61} +@section Pragma Implemented + + Syntax: -@smallexample @c ada +@example pragma Implemented (procedure_LOCAL_NAME, implementation_kind); implementation_kind ::= By_Entry | By_Protected_Procedure | By_Any -@end smallexample +@end example -@noindent This is an Ada 2012 representation pragma which applies to protected, task and synchronized interface primitives. The use of pragma Implemented provides a way to impose a static requirement on the overriding operation by adhering @@ -3454,7 +3610,7 @@ to one of the three implementation kinds: entry, protected procedure or any of the above. This pragma is available in all earlier versions of Ada as an implementation-defined pragma. -@smallexample @c ada +@example type Synch_Iface is synchronized interface; procedure Prim_Op (Obj : in out Iface) is abstract; pragma Implemented (Prim_Op, By_Protected_Procedure); @@ -3470,9 +3626,8 @@ end Prot_2; task type Task_Typ is new Synch_Iface with entry Prim_Op; -- Illegal end Task_Typ; -@end smallexample +@end example -@noindent When applied to the procedure_or_entry_NAME of a requeue statement, pragma Implemented determines the runtime behavior of the requeue. Implementation kind By_Entry guarantees that the action of requeueing will proceed from an entry to @@ -3481,29 +3636,29 @@ requeue into a dispatching call, thus eliminating the chance of blocking. Kind By_Any shares the behavior of By_Entry and By_Protected_Procedure depending on the target's overriding subprogram kind. -@node Pragma Implicit_Packing -@unnumberedsec Pragma Implicit_Packing -@findex Implicit_Packing -@cindex Rational Profile -@noindent +@node Pragma Implicit_Packing,Pragma Import_Function,Pragma Implemented,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-implicit-packing}@anchor{62} +@section Pragma Implicit_Packing + + +@geindex Rational Profile + Syntax: -@smallexample @c ada +@example pragma Implicit_Packing; -@end smallexample +@end example -@noindent This is a configuration pragma that requests implicit packing for packed arrays for which a size clause is given but no explicit pragma Pack or specification of Component_Size is present. It also applies to records where no record representation clause is present. Consider this example: -@smallexample @c ada +@example type R is array (0 .. 7) of Boolean; for R'Size use 8; -@end smallexample +@end example -@noindent In accordance with the recommendation in the RM (RM 13.3(53)), a Size clause does not change the layout of a composite object. So the Size clause in the above example is normally rejected, since the default layout of the array uses @@ -3518,58 +3673,31 @@ specify the exact size that corresponds to the number of elements in the array multiplied by the size in bits of the component type (both single and multi-dimensioned arrays can be controlled with this pragma). -@cindex Array packing +@geindex Array packing Similarly, the following example shows the use in the record case -@smallexample @c ada +@example type r is record a, b, c, d, e, f, g, h : boolean; chr : character; end record; for r'size use 16; -@end smallexample +@end example -@noindent Without a pragma Pack, each Boolean field requires 8 bits, so the minimum size is 72 bits, but with a pragma Pack, 16 bits would be sufficient. The use of pragma Implicit_Packing allows this record declaration to compile without an explicit pragma Pack. -@node Pragma Import_Exception -@unnumberedsec Pragma Import_Exception -@cindex OpenVMS -@findex Import_Exception -@noindent -Syntax: -@smallexample @c ada -pragma Import_Exception ( - [Internal =>] LOCAL_NAME - [, [External =>] EXTERNAL_SYMBOL] - [, [Form =>] Ada | VMS] - [, [Code =>] static_integer_EXPRESSION]); +@node Pragma Import_Function,Pragma Import_Object,Pragma Implicit_Packing,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-import-function}@anchor{63} +@section Pragma Import_Function + -EXTERNAL_SYMBOL ::= - IDENTIFIER -| static_string_EXPRESSION -@end smallexample - -@noindent -This pragma is implemented only in the OpenVMS implementation of GNAT@. -It allows OpenVMS conditions (for example, from OpenVMS system services or -other OpenVMS languages) to be propagated to Ada programs as Ada exceptions. -The pragma specifies that the exception associated with an exception -declaration in an Ada program be defined externally (in non-Ada code). -For further details on this pragma, see the -DEC Ada Language Reference Manual, section 13.9a.3.1. - -@node Pragma Import_Function -@unnumberedsec Pragma Import_Function -@findex Import_Function -@noindent Syntax: -@smallexample @c ada +@example pragma Import_Function ( [Internal =>] LOCAL_NAME, [, [External =>] EXTERNAL_SYMBOL] @@ -3600,27 +3728,26 @@ MECHANISM_ASSOCIATION ::= MECHANISM_NAME ::= Value | Reference -@end smallexample +@end example -@noindent -This pragma is used in conjunction with a pragma @code{Import} to +This pragma is used in conjunction with a pragma @cite{Import} to specify additional information for an imported function. The pragma -@code{Import} (or equivalent pragma @code{Interface}) must precede the -@code{Import_Function} pragma and both must appear in the same +@cite{Import} (or equivalent pragma @cite{Interface}) must precede the +@cite{Import_Function} pragma and both must appear in the same declarative part as the function specification. -The @var{Internal} argument must uniquely designate +The @cite{Internal} argument must uniquely designate the function to which the pragma applies. If more than one function name exists of this name in -the declarative part you must use the @code{Parameter_Types} and -@var{Result_Type} parameters to achieve the required unique +the declarative part you must use the @cite{Parameter_Types} and +@cite{Result_Type} parameters to achieve the required unique designation. Subtype marks in these parameters must exactly match the subtypes in the corresponding function specification, using positional notation to match parameters with subtype marks. -The form with an @code{'Access} attribute can be used to match an +The form with an @cite{'Access} attribute can be used to match an anonymous access parameter. -You may optionally use the @var{Mechanism} and @var{Result_Mechanism} +You may optionally use the @cite{Mechanism} and @cite{Result_Mechanism} parameters to specify passing mechanisms for the parameters and result. If you specify a single mechanism name, it applies to all parameters. Otherwise you may specify a mechanism on a @@ -3628,13 +3755,14 @@ parameter by parameter basis using either positional or named notation. If the mechanism is not specified, the default mechanism is used. -@node Pragma Import_Object -@unnumberedsec Pragma Import_Object -@findex Import_Object -@noindent +@node Pragma Import_Object,Pragma Import_Procedure,Pragma Import_Function,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-import-object}@anchor{64} +@section Pragma Import_Object + + Syntax: -@smallexample @c ada +@example pragma Import_Object [Internal =>] LOCAL_NAME [, [External =>] EXTERNAL_SYMBOL] @@ -3643,24 +3771,24 @@ pragma Import_Object EXTERNAL_SYMBOL ::= IDENTIFIER | static_string_EXPRESSION -@end smallexample +@end example -@noindent This pragma designates an object as imported, and apart from the extended rules for external symbols, is identical in effect to the use of -the normal @code{Import} pragma applied to an object. Unlike the -subprogram case, you need not use a separate @code{Import} pragma, +the normal @cite{Import} pragma applied to an object. Unlike the +subprogram case, you need not use a separate @cite{Import} pragma, although you may do so (and probably should do so from a portability -point of view). @var{size} is syntax checked, but otherwise ignored by -GNAT@. +point of view). @cite{size} is syntax checked, but otherwise ignored by +GNAT. + +@node Pragma Import_Procedure,Pragma Import_Valued_Procedure,Pragma Import_Object,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-import-procedure}@anchor{65} +@section Pragma Import_Procedure + -@node Pragma Import_Procedure -@unnumberedsec Pragma Import_Procedure -@findex Import_Procedure -@noindent Syntax: -@smallexample @c ada +@example pragma Import_Procedure ( [Internal =>] LOCAL_NAME [, [External =>] EXTERNAL_SYMBOL] @@ -3687,20 +3815,20 @@ MECHANISM_ASSOCIATION ::= [formal_parameter_NAME =>] MECHANISM_NAME MECHANISM_NAME ::= Value | Reference -@end smallexample +@end example -@noindent -This pragma is identical to @code{Import_Function} except that it +This pragma is identical to @cite{Import_Function} except that it applies to a procedure rather than a function and the parameters -@code{Result_Type} and @code{Result_Mechanism} are not permitted. +@cite{Result_Type} and @cite{Result_Mechanism} are not permitted. + +@node Pragma Import_Valued_Procedure,Pragma Independent,Pragma Import_Procedure,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-import-valued-procedure}@anchor{66} +@section Pragma Import_Valued_Procedure + -@node Pragma Import_Valued_Procedure -@unnumberedsec Pragma Import_Valued_Procedure -@findex Import_Valued_Procedure -@noindent Syntax: -@smallexample @c ada +@example pragma Import_Valued_Procedure ( [Internal =>] LOCAL_NAME [, [External =>] EXTERNAL_SYMBOL] @@ -3727,16 +3855,15 @@ MECHANISM_ASSOCIATION ::= [formal_parameter_NAME =>] MECHANISM_NAME MECHANISM_NAME ::= Value | Reference -@end smallexample +@end example -@noindent -This pragma is identical to @code{Import_Procedure} except that the -first parameter of @var{LOCAL_NAME}, which must be present, must be of -mode @code{OUT}, and externally the subprogram is treated as a function +This pragma is identical to @cite{Import_Procedure} except that the +first parameter of @cite{LOCAL_NAME}, which must be present, must be of +mode @cite{OUT}, and externally the subprogram is treated as a function with this parameter as the result of the function. The purpose of this -capability is to allow the use of @code{OUT} and @code{IN OUT} +capability is to allow the use of @cite{OUT} and @cite{IN OUT} parameters in interfacing to external functions (which are not permitted -in Ada functions). You may optionally use the @code{Mechanism} +in Ada functions). You may optionally use the @cite{Mechanism} parameters to specify passing mechanisms for the parameters. If you specify a single mechanism name, it applies to all parameters. Otherwise you may specify a mechanism on a parameter by parameter @@ -3747,17 +3874,17 @@ Note that it is important to use this pragma in conjunction with a separate pragma Import that specifies the desired convention, since otherwise the default convention is Ada, which is almost certainly not what is required. -@node Pragma Independent -@unnumberedsec Pragma Independent -@findex Independent -@noindent +@node Pragma Independent,Pragma Independent_Components,Pragma Import_Valued_Procedure,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-independent}@anchor{67} +@section Pragma Independent + + Syntax: -@smallexample @c ada +@example pragma Independent (Local_NAME); -@end smallexample +@end example -@noindent This pragma is standard in Ada 2012 mode (which also provides an aspect of the same name). It is also available as an implementation-defined pragma in all earlier versions. It specifies that the @@ -3769,17 +3896,17 @@ This may place constraints on the representation of the object (for instance prohibiting tight packing). -@node Pragma Independent_Components -@unnumberedsec Pragma Independent_Components -@findex Independent_Components -@noindent +@node Pragma Independent_Components,Pragma Initial_Condition,Pragma Independent,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-independent-components}@anchor{68} +@section Pragma Independent_Components + + Syntax: -@smallexample @c ada +@example pragma Independent_Components (Local_NAME); -@end smallexample +@end example -@noindent This pragma is standard in Ada 2012 mode (which also provides an aspect of the same name). It is also available as an implementation-defined pragma in all earlier versions. It specifies that the components of the @@ -3790,26 +3917,28 @@ manipulate separate components in the composite object. This may place constraints on the representation of the object (for instance prohibiting tight packing). -@node Pragma Initial_Condition -@unnumberedsec Pragma Initial_Condition -@findex Initial_Condition -@noindent +@node Pragma Initial_Condition,Pragma Initialize_Scalars,Pragma Independent_Components,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-initial-condition}@anchor{69} +@section Pragma Initial_Condition + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.1.6. -@node Pragma Initialize_Scalars -@unnumberedsec Pragma Initialize_Scalars -@findex Initialize_Scalars -@cindex debugging with Initialize_Scalars -@noindent +@node Pragma Initialize_Scalars,Pragma Initializes,Pragma Initial_Condition,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-initialize-scalars}@anchor{6a} +@section Pragma Initialize_Scalars + + +@geindex debugging with Initialize_Scalars + Syntax: -@smallexample @c ada +@example pragma Initialize_Scalars; -@end smallexample +@end example -@noindent -This pragma is similar to @code{Normalize_Scalars} conceptually but has +This pragma is similar to @cite{Normalize_Scalars} conceptually but has two important differences. First, there is no requirement for the pragma to be used uniformly in all units of a partition, in particular, it is fine to use this just for some or all of the application units of a partition, @@ -3829,7 +3958,7 @@ initialize with invalid values (similar to Normalize_Scalars, though for Initialize_Scalars it is not always possible to determine the invalid values in complex cases like signed component fields with non-standard sizes). You can also initialize with high or -low values, or with a specified bit pattern. See the @value{EDITION} +low values, or with a specified bit pattern. See the GNAT User's Guide for binder options for specifying these cases. This means that you can compile a program, and then without having to @@ -3841,186 +3970,192 @@ uninitialized value. It is even possible to change the value at execution time eliminating even the need to rebind with a different switch using an environment variable. -See the @value{EDITION} User's Guide for details. +See the GNAT User's Guide for details. -Note that pragma @code{Initialize_Scalars} is particularly useful in +Note that pragma @cite{Initialize_Scalars} is particularly useful in conjunction with the enhanced validity checking that is now provided in GNAT, which checks for invalid values under more conditions. -Using this feature (see description of the @option{-gnatV} flag in the -@value{EDITION} User's Guide) in conjunction with -pragma @code{Initialize_Scalars} +Using this feature (see description of the @emph{-gnatV} flag in the +GNAT User's Guide) in conjunction with +pragma @cite{Initialize_Scalars} provides a powerful new tool to assist in the detection of problems caused by uninitialized variables. -Note: the use of @code{Initialize_Scalars} has a fairly extensive +Note: the use of @cite{Initialize_Scalars} has a fairly extensive effect on the generated code. This may cause your code to be substantially larger. It may also cause an increase in the amount of stack required, so it is probably a good idea to turn on stack -checking (see description of stack checking in the @value{EDITION} +checking (see description of stack checking in the GNAT User's Guide) when using this pragma. -@node Pragma Initializes -@unnumberedsec Pragma Initializes -@findex Initializes -@noindent +@node Pragma Initializes,Pragma Inline_Always,Pragma Initialize_Scalars,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-initializes}@anchor{6b} +@section Pragma Initializes + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.1.5. -@node Pragma Inline_Always -@unnumberedsec Pragma Inline_Always -@findex Inline_Always -@noindent +@node Pragma Inline_Always,Pragma Inline_Generic,Pragma Initializes,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-inline-always}@anchor{6c} +@section Pragma Inline_Always + + Syntax: -@smallexample @c ada +@example pragma Inline_Always (NAME [, NAME]); -@end smallexample +@end example -@noindent -Similar to pragma @code{Inline} except that inlining is not subject to -the use of option @option{-gnatn} or @option{-gnatN} and the inlining +Similar to pragma @cite{Inline} except that inlining is not subject to +the use of option @emph{-gnatn} or @emph{-gnatN} and the inlining happens regardless of whether these options are used. -@node Pragma Inline_Generic -@unnumberedsec Pragma Inline_Generic -@findex Inline_Generic -@noindent +@node Pragma Inline_Generic,Pragma Interface,Pragma Inline_Always,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-inline-generic}@anchor{6d} +@section Pragma Inline_Generic + + Syntax: -@smallexample @c ada +@example pragma Inline_Generic (GNAME @{, GNAME@}); GNAME ::= generic_unit_NAME | generic_instance_NAME -@end smallexample +@end example -@noindent This pragma is provided for compatibility with Dec Ada 83. It has -no effect in @code{GNAT} (which always inlines generics), other +no effect in @cite{GNAT} (which always inlines generics), other than to check that the given names are all names of generic units or generic instances. -@node Pragma Interface -@unnumberedsec Pragma Interface -@findex Interface -@noindent +@node Pragma Interface,Pragma Interface_Name,Pragma Inline_Generic,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-interface}@anchor{6e} +@section Pragma Interface + + Syntax: -@smallexample @c ada +@example pragma Interface ( [Convention =>] convention_identifier, [Entity =>] local_NAME [, [External_Name =>] static_string_expression] [, [Link_Name =>] static_string_expression]); -@end smallexample +@end example -@noindent This pragma is identical in syntax and semantics to -the standard Ada pragma @code{Import}. It is provided for compatibility +the standard Ada pragma @cite{Import}. It is provided for compatibility with Ada 83. The definition is upwards compatible both with pragma -@code{Interface} as defined in the Ada 83 Reference Manual, and also +@cite{Interface} as defined in the Ada 83 Reference Manual, and also with some extended implementations of this pragma in certain Ada 83 -implementations. The only difference between pragma @code{Interface} -and pragma @code{Import} is that there is special circuitry to allow +implementations. The only difference between pragma @cite{Interface} +and pragma @cite{Import} is that there is special circuitry to allow both pragmas to appear for the same subprogram entity (normally it -is illegal to have multiple @code{Import} pragmas. This is useful in +is illegal to have multiple @cite{Import} pragmas. This is useful in maintaining Ada 83/Ada 95 compatibility and is compatible with other Ada 83 compilers. -@node Pragma Interface_Name -@unnumberedsec Pragma Interface_Name -@findex Interface_Name -@noindent +@node Pragma Interface_Name,Pragma Interrupt_Handler,Pragma Interface,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-interface-name}@anchor{6f} +@section Pragma Interface_Name + + Syntax: -@smallexample @c ada +@example pragma Interface_Name ( [Entity =>] LOCAL_NAME [, [External_Name =>] static_string_EXPRESSION] [, [Link_Name =>] static_string_EXPRESSION]); -@end smallexample +@end example -@noindent This pragma provides an alternative way of specifying the interface name for an interfaced subprogram, and is provided for compatibility with Ada 83 compilers that use the pragma for this purpose. You must provide at -least one of @var{External_Name} or @var{Link_Name}. +least one of @cite{External_Name} or @cite{Link_Name}. + +@node Pragma Interrupt_Handler,Pragma Interrupt_State,Pragma Interface_Name,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-interrupt-handler}@anchor{70} +@section Pragma Interrupt_Handler + -@node Pragma Interrupt_Handler -@unnumberedsec Pragma Interrupt_Handler -@findex Interrupt_Handler -@noindent Syntax: -@smallexample @c ada +@example pragma Interrupt_Handler (procedure_LOCAL_NAME); -@end smallexample +@end example -@noindent This program unit pragma is supported for parameterless protected procedures as described in Annex C of the Ada Reference Manual. On the AAMP target the pragma can also be specified for nonprotected parameterless procedures that are declared at the library level (which includes procedures declared at the top level of a library package). In the case of AAMP, when this pragma is applied to a nonprotected procedure, the instruction -@code{IERET} is generated for returns from the procedure, enabling +@cite{IERET} is generated for returns from the procedure, enabling maskable interrupts, in place of the normal return instruction. -@node Pragma Interrupt_State -@unnumberedsec Pragma Interrupt_State -@findex Interrupt_State -@noindent +@node Pragma Interrupt_State,Pragma Invariant,Pragma Interrupt_Handler,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-interrupt-state}@anchor{71} +@section Pragma Interrupt_State + + Syntax: -@smallexample @c ada +@example pragma Interrupt_State ([Name =>] value, [State =>] SYSTEM | RUNTIME | USER); -@end smallexample +@end example -@noindent Normally certain interrupts are reserved to the implementation. Any attempt to attach an interrupt causes Program_Error to be raised, as described in -RM C.3.2(22). A typical example is the @code{SIGINT} interrupt used in -many systems for an @kbd{Ctrl-C} interrupt. Normally this interrupt is -reserved to the implementation, so that @kbd{Ctrl-C} can be used to -interrupt execution. Additionally, signals such as @code{SIGSEGV}, -@code{SIGABRT}, @code{SIGFPE} and @code{SIGILL} are often mapped to specific +RM C.3.2(22). A typical example is the @cite{SIGINT} interrupt used in +many systems for an @code{Ctrl-C} interrupt. Normally this interrupt is +reserved to the implementation, so that @code{Ctrl-C} can be used to +interrupt execution. Additionally, signals such as @cite{SIGSEGV}, +@cite{SIGABRT}, @cite{SIGFPE} and @cite{SIGILL} are often mapped to specific Ada exceptions, or used to implement run-time functions such as the -@code{abort} statement and stack overflow checking. +@cite{abort} statement and stack overflow checking. -Pragma @code{Interrupt_State} provides a general mechanism for overriding +Pragma @cite{Interrupt_State} provides a general mechanism for overriding such uses of interrupts. It subsumes the functionality of pragma -@code{Unreserve_All_Interrupts}. Pragma @code{Interrupt_State} is not +@cite{Unreserve_All_Interrupts}. Pragma @cite{Interrupt_State} is not available on Windows or VMS. On all other platforms than VxWorks, it applies to signals; on VxWorks, it applies to vectored hardware interrupts and may be used to mark interrupts required by the board support package as reserved. Interrupts can be in one of three states: -@itemize @bullet -@item System + + +@itemize * + +@item +System The interrupt is reserved (no Ada handler can be installed), and the Ada run-time may not install a handler. As a result you are guaranteed standard system default action if this interrupt is raised. -@item Runtime +@item +Runtime The interrupt is reserved (no Ada handler can be installed). The run time is allowed to install a handler for internal control purposes, but is not required to do so. -@item User +@item +User The interrupt is unreserved. The user may install a handler to provide some other action. @end itemize -@noindent -These states are the allowed values of the @code{State} parameter of the -pragma. The @code{Name} parameter is a value of the type -@code{Ada.Interrupts.Interrupt_ID}. Typically, it is a name declared in -@code{Ada.Interrupts.Names}. +These states are the allowed values of the @cite{State} parameter of the +pragma. The @cite{Name} parameter is a value of the type +@cite{Ada.Interrupts.Interrupt_ID}. Typically, it is a name declared in +@cite{Ada.Interrupts.Names}. This is a configuration pragma, and the binder will check that there are no inconsistencies between different units in a partition in how a @@ -4036,27 +4171,27 @@ a handler. Note that certain signals on many operating systems cannot be caught and handled by applications. In such cases, the pragma is ignored. See the -operating system documentation, or the value of the array @code{Reserved} -declared in the spec of package @code{System.OS_Interface}. +operating system documentation, or the value of the array @cite{Reserved} +declared in the spec of package @cite{System.OS_Interface}. Overriding the default state of signals used by the Ada runtime may interfere with an application's runtime behavior in the cases of the synchronous signals, -and in the case of the signal used to implement the @code{abort} statement. +and in the case of the signal used to implement the @cite{abort} statement. + +@node Pragma Invariant,Pragma Java_Constructor,Pragma Interrupt_State,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-invariant}@anchor{72} +@section Pragma Invariant + -@node Pragma Invariant -@unnumberedsec Pragma Invariant -@findex Invariant -@noindent Syntax: -@smallexample @c ada +@example pragma Invariant ([Entity =>] private_type_LOCAL_NAME, [Check =>] EXPRESSION [,[Message =>] String_Expression]); -@end smallexample +@end example -@noindent This pragma provides exactly the same capabilities as the Type_Invariant aspect defined in AI05-0146-1, and in the Ada 2012 Reference Manual. The Type_Invariant aspect is fully implemented in Ada 2012 mode, but since it @@ -4082,210 +4217,211 @@ invariant pragma for the same entity. For further details on the use of this pragma, see the Ada 2012 documentation of the Type_Invariant aspect. -@node Pragma Java_Constructor -@unnumberedsec Pragma Java_Constructor -@findex Java_Constructor -@noindent +@node Pragma Java_Constructor,Pragma Java_Interface,Pragma Invariant,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-java-constructor}@anchor{73} +@section Pragma Java_Constructor + + Syntax: -@smallexample @c ada +@example pragma Java_Constructor ([Entity =>] function_LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma is used to assert that the specified Ada function should be mapped to the Java constructor for some Ada tagged record type. See section 7.3.2 of the -@code{GNAT User's Guide: Supplement for the JVM Platform.} +@cite{GNAT User's Guide: Supplement for the JVM Platform.} for related information. -@node Pragma Java_Interface -@unnumberedsec Pragma Java_Interface -@findex Java_Interface -@noindent +@node Pragma Java_Interface,Pragma Keep_Names,Pragma Java_Constructor,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-java-interface}@anchor{74} +@section Pragma Java_Interface + + Syntax: -@smallexample @c ada +@example pragma Java_Interface ([Entity =>] abstract_tagged_type_LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma is used to assert that the specified Ada abstract tagged type is to be mapped to a Java interface name. See sections 7.1 and 7.2 of the -@code{GNAT User's Guide: Supplement for the JVM Platform.} +@cite{GNAT User's Guide: Supplement for the JVM Platform.} for related information. -@node Pragma Keep_Names -@unnumberedsec Pragma Keep_Names -@findex Keep_Names -@noindent +@node Pragma Keep_Names,Pragma License,Pragma Java_Interface,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-keep-names}@anchor{75} +@section Pragma Keep_Names + + Syntax: -@smallexample @c ada +@example pragma Keep_Names ([On =>] enumeration_first_subtype_LOCAL_NAME); -@end smallexample +@end example -@noindent -The @var{LOCAL_NAME} argument +The @cite{LOCAL_NAME} argument must refer to an enumeration first subtype in the current declarative part. The effect is to retain the enumeration -literal names for use by @code{Image} and @code{Value} even if a global -@code{Discard_Names} pragma applies. This is useful when you want to +literal names for use by @cite{Image} and @cite{Value} even if a global +@cite{Discard_Names} pragma applies. This is useful when you want to generally suppress enumeration literal names and for example you therefore -use a @code{Discard_Names} pragma in the @file{gnat.adc} file, but you +use a @cite{Discard_Names} pragma in the @code{gnat.adc} file, but you want to retain the names for specific enumeration types. -@node Pragma License -@unnumberedsec Pragma License -@findex License -@cindex License checking -@noindent +@node Pragma License,Pragma Link_With,Pragma Keep_Names,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-license}@anchor{76} +@section Pragma License + + +@geindex License checking + Syntax: -@smallexample @c ada +@example pragma License (Unrestricted | GPL | Modified_GPL | Restricted); -@end smallexample +@end example -@noindent This pragma is provided to allow automated checking for appropriate license -conditions with respect to the standard and modified GPL@. A pragma -@code{License}, which is a configuration pragma that typically appears at -the start of a source file or in a separate @file{gnat.adc} file, specifies +conditions with respect to the standard and modified GPL. A pragma +@cite{License}, which is a configuration pragma that typically appears at +the start of a source file or in a separate @code{gnat.adc} file, specifies the licensing conditions of a unit as follows: -@itemize @bullet -@item Unrestricted + +@itemize * + +@item +Unrestricted This is used for a unit that can be freely used with no license restrictions. Examples of such units are public domain units, and units from the Ada Reference Manual. -@item GPL +@item +GPL This is used for a unit that is licensed under the unmodified GPL, and which -therefore cannot be @code{with}'ed by a restricted unit. +therefore cannot be @cite{with}'ed by a restricted unit. -@item Modified_GPL +@item +Modified_GPL This is used for a unit licensed under the GNAT modified GPL that includes a special exception paragraph that specifically permits the inclusion of the unit in programs without requiring the entire program to be released -under the GPL@. +under the GPL. -@item Restricted +@item +Restricted This is used for a unit that is restricted in that it is not permitted to -depend on units that are licensed under the GPL@. Typical examples are +depend on units that are licensed under the GPL. Typical examples are proprietary code that is to be released under more restrictive license -conditions. Note that restricted units are permitted to @code{with} units +conditions. Note that restricted units are permitted to @cite{with} units which are licensed under the modified GPL (this is the whole point of the modified GPL). - @end itemize -@noindent -Normally a unit with no @code{License} pragma is considered to have an +Normally a unit with no @cite{License} pragma is considered to have an unknown license, and no checking is done. However, standard GNAT headers are recognized, and license information is derived from them as follows. A GNAT license header starts with a line containing 78 hyphens. The following comment text is searched for the appearance of any of the following strings. -If the string ``GNU General Public License'' is found, then the unit is assumed -to have GPL license, unless the string ``As a special exception'' follows, in -which case the license is assumed to be modified GPL@. +If the string 'GNU General Public License' is found, then the unit is assumed +to have GPL license, unless the string 'As a special exception' follows, in +which case the license is assumed to be modified GPL. If one of the strings -``This specification is adapted from the Ada Semantic Interface'' or -``This specification is derived from the Ada Reference Manual'' is found +'This specification is adapted from the Ada Semantic Interface' or +'This specification is derived from the Ada Reference Manual' is found then the unit is assumed to be unrestricted. -@noindent These default actions means that a program with a restricted license pragma will automatically get warnings if a GPL unit is inappropriately -@code{with}'ed. For example, the program: +@cite{with}'ed. For example, the program: -@smallexample @c ada +@example with Sem_Ch3; with GNAT.Sockets; procedure Secret_Stuff is - @dots{} + ... end Secret_Stuff -@end smallexample +@end example -@noindent -if compiled with pragma @code{License} (@code{Restricted}) in a -@file{gnat.adc} file will generate the warning: +if compiled with pragma @cite{License} (@cite{Restricted}) in a +@code{gnat.adc} file will generate the warning: -@smallexample +@example 1. with Sem_Ch3; | >>> license of withed unit "Sem_Ch3" is incompatible 2. with GNAT.Sockets; 3. procedure Secret_Stuff is -@end smallexample +@end example -@noindent -Here we get a warning on @code{Sem_Ch3} since it is part of the GNAT +Here we get a warning on @cite{Sem_Ch3} since it is part of the GNAT compiler and is licensed under the -GPL, but no warning for @code{GNAT.Sockets} which is part of the GNAT -run time, and is therefore licensed under the modified GPL@. +GPL, but no warning for @cite{GNAT.Sockets} which is part of the GNAT +run time, and is therefore licensed under the modified GPL. + +@node Pragma Link_With,Pragma Linker_Alias,Pragma License,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-link-with}@anchor{77} +@section Pragma Link_With + -@node Pragma Link_With -@unnumberedsec Pragma Link_With -@findex Link_With -@noindent Syntax: -@smallexample @c ada +@example pragma Link_With (static_string_EXPRESSION @{,static_string_EXPRESSION@}); -@end smallexample +@end example -@noindent This pragma is provided for compatibility with certain Ada 83 compilers. -It has exactly the same effect as pragma @code{Linker_Options} except +It has exactly the same effect as pragma @cite{Linker_Options} except that spaces occurring within one of the string expressions are treated as separators. For example, in the following case: -@smallexample @c ada +@example pragma Link_With ("-labc -ldef"); -@end smallexample +@end example -@noindent -results in passing the strings @code{-labc} and @code{-ldef} as two +results in passing the strings @cite{-labc} and @cite{-ldef} as two separate arguments to the linker. In addition pragma Link_With allows multiple arguments, with the same effect as successive pragmas. -@node Pragma Linker_Alias -@unnumberedsec Pragma Linker_Alias -@findex Linker_Alias -@noindent +@node Pragma Linker_Alias,Pragma Linker_Constructor,Pragma Link_With,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-linker-alias}@anchor{78} +@section Pragma Linker_Alias + + Syntax: -@smallexample @c ada +@example pragma Linker_Alias ( [Entity =>] LOCAL_NAME, [Target =>] static_string_EXPRESSION); -@end smallexample +@end example -@noindent -@var{LOCAL_NAME} must refer to an object that is declared at the library +@cite{LOCAL_NAME} must refer to an object that is declared at the library level. This pragma establishes the given entity as a linker alias for the -given target. It is equivalent to @code{__attribute__((alias))} in GNU C -and causes @var{LOCAL_NAME} to be emitted as an alias for the symbol -@var{static_string_EXPRESSION} in the object file, that is to say no space -is reserved for @var{LOCAL_NAME} by the assembler and it will be resolved -to the same address as @var{static_string_EXPRESSION} by the linker. +given target. It is equivalent to @cite{__attribute__((alias))} in GNU C +and causes @cite{LOCAL_NAME} to be emitted as an alias for the symbol +@cite{static_string_EXPRESSION} in the object file, that is to say no space +is reserved for @cite{LOCAL_NAME} by the assembler and it will be resolved +to the same address as @cite{static_string_EXPRESSION} by the linker. -The actual linker name for the target must be used (e.g.@: the fully +The actual linker name for the target must be used (e.g., the fully encoded name with qualification in Ada, or the mangled name in C++), -or it must be declared using the C convention with @code{pragma Import} -or @code{pragma Export}. +or it must be declared using the C convention with @cite{pragma Import} +or @cite{pragma Export}. Not all target machines support this pragma. On some of them it is accepted -only if @code{pragma Weak_External} has been applied to @var{LOCAL_NAME}. +only if @cite{pragma Weak_External} has been applied to @cite{LOCAL_NAME}. -@smallexample @c ada +@example -- Example of the use of pragma Linker_Alias package p is @@ -4295,24 +4431,24 @@ package p is new_name_for_i : Integer; pragma Linker_Alias (new_name_for_i, "i"); end p; -@end smallexample +@end example + +@node Pragma Linker_Constructor,Pragma Linker_Destructor,Pragma Linker_Alias,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-linker-constructor}@anchor{79} +@section Pragma Linker_Constructor + -@node Pragma Linker_Constructor -@unnumberedsec Pragma Linker_Constructor -@findex Linker_Constructor -@noindent Syntax: -@smallexample @c ada +@example pragma Linker_Constructor (procedure_LOCAL_NAME); -@end smallexample +@end example -@noindent -@var{procedure_LOCAL_NAME} must refer to a parameterless procedure that +@cite{procedure_LOCAL_NAME} must refer to a parameterless procedure that is declared at the library level. A procedure to which this pragma is applied will be treated as an initialization routine by the linker. -It is equivalent to @code{__attribute__((constructor))} in GNU C and -causes @var{procedure_LOCAL_NAME} to be invoked before the entry point +It is equivalent to @cite{__attribute__((constructor))} in GNU C and +causes @cite{procedure_LOCAL_NAME} to be invoked before the entry point of the executable is called (or immediately after the shared library is loaded if the procedure is linked in a shared library), in particular before the Ada run-time environment is set up. @@ -4327,47 +4463,47 @@ Alone Libraries, which provides a related capability without the restrictions listed above. Where possible, the use of Stand Alone Libraries is preferable to the use of this pragma. -@node Pragma Linker_Destructor -@unnumberedsec Pragma Linker_Destructor -@findex Linker_Destructor -@noindent +@node Pragma Linker_Destructor,Pragma Linker_Section,Pragma Linker_Constructor,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-linker-destructor}@anchor{7a} +@section Pragma Linker_Destructor + + Syntax: -@smallexample @c ada +@example pragma Linker_Destructor (procedure_LOCAL_NAME); -@end smallexample +@end example -@noindent -@var{procedure_LOCAL_NAME} must refer to a parameterless procedure that +@cite{procedure_LOCAL_NAME} must refer to a parameterless procedure that is declared at the library level. A procedure to which this pragma is applied will be treated as a finalization routine by the linker. -It is equivalent to @code{__attribute__((destructor))} in GNU C and -causes @var{procedure_LOCAL_NAME} to be invoked after the entry point +It is equivalent to @cite{__attribute__((destructor))} in GNU C and +causes @cite{procedure_LOCAL_NAME} to be invoked after the entry point of the executable has exited (or immediately before the shared library is unloaded if the procedure is linked in a shared library), in particular after the Ada run-time environment is shut down. -See @code{pragma Linker_Constructor} for the set of restrictions that apply +See @cite{pragma Linker_Constructor} for the set of restrictions that apply because of these specific contexts. -@node Pragma Linker_Section -@unnumberedsec Pragma Linker_Section -@findex Linker_Section -@noindent +@node Pragma Linker_Section,Pragma Lock_Free,Pragma Linker_Destructor,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-linker-section}@anchor{7b} +@section Pragma Linker_Section + + Syntax: -@smallexample @c ada +@example pragma Linker_Section ( [Entity =>] LOCAL_NAME, [Section =>] static_string_EXPRESSION); -@end smallexample +@end example -@noindent -@var{LOCAL_NAME} must refer to an object, type, or subprogram that is +@cite{LOCAL_NAME} must refer to an object, type, or subprogram that is declared at the library level. This pragma specifies the name of the linker section for the given entity. It is equivalent to -@code{__attribute__((section))} in GNU C and causes @var{LOCAL_NAME} to -be placed in the @var{static_string_EXPRESSION} section of the +@cite{__attribute__((section))} in GNU C and causes @cite{LOCAL_NAME} to +be placed in the @cite{static_string_EXPRESSION} section of the executable (assuming the linker doesn't rename the section). GNAT also provides an implementation defined aspect of the same name. @@ -4390,8 +4526,8 @@ linker section is specified should has the default linker section. The compiler normally places library-level entities in standard sections depending on the class: procedures and functions generally go in the -@code{.text} section, initialized variables in the @code{.data} section -and uninitialized variables in the @code{.bss} section. +@cite{.text} section, initialized variables in the @cite{.data} section +and uninitialized variables in the @cite{.bss} section. Other, special sections may exist on given target machines to map special hardware, for example I/O ports or flash memory. This pragma is a means to @@ -4401,10 +4537,10 @@ at the symbolic level with the compiler. Some file formats do not support arbitrary sections so not all target machines support this pragma. The use of this pragma may cause a program execution to be erroneous if it is used to place an entity into an -inappropriate section (e.g.@: a modified variable into the @code{.text} -section). See also @code{pragma Persistent_BSS}. +inappropriate section (e.g., a modified variable into the @cite{.text} +section). See also @cite{pragma Persistent_BSS}. -@smallexample @c ada +@example -- Example of the use of pragma Linker_Section package IO_Card is @@ -4422,57 +4558,36 @@ package IO_Card is procedure Q with Linker_Section => "Qsection"; end IO_Card; -@end smallexample +@end example + +@node Pragma Lock_Free,Pragma Loop_Invariant,Pragma Linker_Section,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-lock-free}@anchor{7c} +@section Pragma Lock_Free + -@node Pragma Lock_Free -@unnumberedsec Pragma Lock_Free -@findex Lock_Free -@noindent Syntax: This pragma may be specified for protected types or objects. It specifies that the implementation of protected operations must be implemented without locks. Compilation fails if the compiler cannot generate lock-free code for the operations. -@node Pragma Long_Float -@unnumberedsec Pragma Long_Float -@cindex OpenVMS -@findex Long_Float -@noindent -Syntax: +@node Pragma Loop_Invariant,Pragma Loop_Optimize,Pragma Lock_Free,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-loop-invariant}@anchor{7d} +@section Pragma Loop_Invariant + -@smallexample @c ada -pragma Long_Float (FLOAT_FORMAT); - -FLOAT_FORMAT ::= D_Float | G_Float -@end smallexample - -@noindent -This pragma is implemented only in the OpenVMS implementation of GNAT@. -It allows control over the internal representation chosen for the predefined -type @code{Long_Float} and for floating point type representations with -@code{digits} specified in the range 7 through 15. -For further details on this pragma, see the -@cite{DEC Ada Language Reference Manual}, section 3.5.7b. Note that to use -this pragma, the standard runtime libraries must be recompiled. - -@node Pragma Loop_Invariant -@unnumberedsec Pragma Loop_Invariant -@findex Loop_Invariant -@noindent Syntax: -@smallexample @c ada +@example pragma Loop_Invariant ( boolean_EXPRESSION ); -@end smallexample +@end example -@noindent -The effect of this pragma is similar to that of pragma @code{Assert}, -except that in an @code{Assertion_Policy} pragma, the identifier -@code{Loop_Invariant} is used to control whether it is ignored or checked +The effect of this pragma is similar to that of pragma @cite{Assert}, +except that in an @cite{Assertion_Policy} pragma, the identifier +@cite{Loop_Invariant} is used to control whether it is ignored or checked (or disabled). -@code{Loop_Invariant} can only appear as one of the items in the sequence +@cite{Loop_Invariant} can only appear as one of the items in the sequence of statements of a loop body, or nested inside block statements that appear in the sequence of statements of a loop body. The intention is that it be used to @@ -4480,28 +4595,28 @@ represent a "loop invariant" assertion, i.e. something that is true each time through the loop, and which can be used to show that the loop is achieving its purpose. -Multiple @code{Loop_Invariant} and @code{Loop_Variant} pragmas that +Multiple @cite{Loop_Invariant} and @cite{Loop_Variant} pragmas that apply to the same loop should be grouped in the same sequence of statements. -To aid in writing such invariants, the special attribute @code{Loop_Entry} +To aid in writing such invariants, the special attribute @cite{Loop_Entry} may be used to refer to the value of an expression on entry to the loop. This -attribute can only be used within the expression of a @code{Loop_Invariant} -pragma. For full details, see documentation of attribute @code{Loop_Entry}. +attribute can only be used within the expression of a @cite{Loop_Invariant} +pragma. For full details, see documentation of attribute @cite{Loop_Entry}. + +@node Pragma Loop_Optimize,Pragma Loop_Variant,Pragma Loop_Invariant,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-loop-optimize}@anchor{7e} +@section Pragma Loop_Optimize + -@node Pragma Loop_Optimize -@unnumberedsec Pragma Loop_Optimize -@findex Loop_Optimize -@noindent Syntax: -@smallexample @c ada +@example pragma Loop_Optimize (OPTIMIZATION_HINT @{, OPTIMIZATION_HINT@}); OPTIMIZATION_HINT ::= Ivdep | No_Unroll | Unroll | No_Vector | Vector -@end smallexample +@end example -@noindent This pragma must appear immediately within a loop statement. It allows the programmer to specify optimization hints for the enclosing loop. The hints are not mutually exclusive and can be freely mixed, but not all combinations @@ -4509,56 +4624,62 @@ will yield a sensible outcome. There are five supported optimization hints for a loop: -@itemize @bullet -@item Ivdep + +@itemize * + +@item +Ivdep The programmer asserts that there are no loop-carried dependencies which would prevent consecutive iterations of the loop from being executed simultaneously. -@item No_Unroll +@item +No_Unroll The loop must not be unrolled. This is a strong hint: the compiler will not unroll a loop marked with this hint. -@item Unroll +@item +Unroll The loop should be unrolled. This is a weak hint: the compiler will try to apply unrolling to this loop preferably to other optimizations, notably vectorization, but there is no guarantee that the loop will be unrolled. -@item No_Vector +@item +No_Vector The loop must not be vectorized. This is a strong hint: the compiler will not vectorize a loop marked with this hint. -@item Vector +@item +Vector The loop should be vectorized. This is a weak hint: the compiler will try to apply vectorization to this loop preferably to other optimizations, notably unrolling, but there is no guarantee that the loop will be vectorized. - @end itemize These hints do not remove the need to pass the appropriate switches to the compiler in order to enable the relevant optimizations, that is to say -@option{-funroll-loops} for unrolling and @option{-ftree-vectorize} for +@emph{-funroll-loops} for unrolling and @emph{-ftree-vectorize} for vectorization. -@node Pragma Loop_Variant -@unnumberedsec Pragma Loop_Variant -@findex Loop_Variant -@noindent +@node Pragma Loop_Variant,Pragma Machine_Attribute,Pragma Loop_Optimize,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-loop-variant}@anchor{7f} +@section Pragma Loop_Variant + + Syntax: -@smallexample @c ada +@example pragma Loop_Variant ( LOOP_VARIANT_ITEM @{, LOOP_VARIANT_ITEM @} ); LOOP_VARIANT_ITEM ::= CHANGE_DIRECTION => discrete_EXPRESSION CHANGE_DIRECTION ::= Increases | Decreases -@end smallexample +@end example -@noindent -@code{Loop_Variant} can only appear as one of the items in the sequence +@cite{Loop_Variant} can only appear as one of the items in the sequence of statements of a loop body, or nested inside block statements that appear in the sequence of statements of a loop body. It allows the specification of quantities which must always @@ -4569,64 +4690,62 @@ on each iteration of the loop. In a more complex form, multiple arguments can be given which are intepreted in a nesting lexicographic manner. For example: -@smallexample @c ada +@example pragma Loop_Variant (Increases => X, Decreases => Y); -@end smallexample +@end example -@noindent specifies that each time through the loop either X increases, or X stays -the same and Y decreases. A @code{Loop_Variant} pragma ensures that the +the same and Y decreases. A @cite{Loop_Variant} pragma ensures that the loop is making progress. It can be useful in helping to show informally or prove formally that the loop always terminates. -@code{Loop_Variant} is an assertion whose effect can be controlled using -an @code{Assertion_Policy} with a check name of @code{Loop_Variant}. The -policy can be @code{Check} to enable the loop variant check, @code{Ignore} +@cite{Loop_Variant} is an assertion whose effect can be controlled using +an @cite{Assertion_Policy} with a check name of @cite{Loop_Variant}. The +policy can be @cite{Check} to enable the loop variant check, @cite{Ignore} to ignore the check (in which case the pragma has no effect on the program), -or @code{Disable} in which case the pragma is not even checked for correct +or @cite{Disable} in which case the pragma is not even checked for correct syntax. -Multiple @code{Loop_Invariant} and @code{Loop_Variant} pragmas that +Multiple @cite{Loop_Invariant} and @cite{Loop_Variant} pragmas that apply to the same loop should be grouped in the same sequence of statements. -The @code{Loop_Entry} attribute may be used within the expressions of the -@code{Loop_Variant} pragma to refer to values on entry to the loop. +The @cite{Loop_Entry} attribute may be used within the expressions of the +@cite{Loop_Variant} pragma to refer to values on entry to the loop. + +@node Pragma Machine_Attribute,Pragma Main,Pragma Loop_Variant,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-machine-attribute}@anchor{80} +@section Pragma Machine_Attribute + -@node Pragma Machine_Attribute -@unnumberedsec Pragma Machine_Attribute -@findex Machine_Attribute -@noindent Syntax: -@smallexample @c ada +@example pragma Machine_Attribute ( [Entity =>] LOCAL_NAME, [Attribute_Name =>] static_string_EXPRESSION [, [Info =>] static_EXPRESSION] ); -@end smallexample +@end example -@noindent Machine-dependent attributes can be specified for types and/or declarations. This pragma is semantically equivalent to -@code{__attribute__((@var{attribute_name}))} (if @var{info} is not -specified) or @code{__attribute__((@var{attribute_name}(@var{info})))} -in GNU C, where @code{@var{attribute_name}} is recognized by the -compiler middle-end or the @code{TARGET_ATTRIBUTE_TABLE} machine -specific macro. A string literal for the optional parameter @var{info} +@cite{__attribute__((`attribute_name}))` (if @cite{info} is not +specified) or @cite{__attribute__((`attribute_name`(`info}))) +in GNU C, where @code{attribute_name} is recognized by the +compiler middle-end or the @cite{TARGET_ATTRIBUTE_TABLE} machine +specific macro. A string literal for the optional parameter @cite{info} is transformed into an identifier, which may make this pragma unusable -for some attributes. @xref{Target Attributes,, Defining target-specific -uses of @code{__attribute__}, gccint, GNU Compiler Collection (GCC) -Internals}, further information. - -@node Pragma Main -@unnumberedsec Pragma Main -@cindex OpenVMS -@findex Main -@noindent +for some attributes. +For further information see @cite{GNU Compiler Collection (GCC) Internals}. + +@node Pragma Main,Pragma Main_Storage,Pragma Machine_Attribute,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-main}@anchor{81} +@section Pragma Main + + Syntax: -@smallexample @c ada +@example pragma Main (MAIN_OPTION [, MAIN_OPTION]); @@ -4634,44 +4753,41 @@ MAIN_OPTION ::= [Stack_Size =>] static_integer_EXPRESSION | [Task_Stack_Size_Default =>] static_integer_EXPRESSION | [Time_Slicing_Enabled =>] static_boolean_EXPRESSION -@end smallexample +@end example -@noindent This pragma is provided for compatibility with OpenVMS VAX Systems. It has no effect in GNAT, other than being syntax checked. -@node Pragma Main_Storage -@unnumberedsec Pragma Main_Storage -@cindex OpenVMS -@findex Main_Storage -@noindent +@node Pragma Main_Storage,Pragma No_Body,Pragma Main,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-main-storage}@anchor{82} +@section Pragma Main_Storage + + Syntax: -@smallexample @c ada +@example pragma Main_Storage (MAIN_STORAGE_OPTION [, MAIN_STORAGE_OPTION]); MAIN_STORAGE_OPTION ::= [WORKING_STORAGE =>] static_SIMPLE_EXPRESSION | [TOP_GUARD =>] static_SIMPLE_EXPRESSION -@end smallexample +@end example -@noindent This pragma is provided for compatibility with OpenVMS VAX Systems. It has -no effect in GNAT, other than being syntax checked. Note that the pragma -also has no effect in DEC Ada 83 for OpenVMS Alpha Systems. +no effect in GNAT, other than being syntax checked. + +@node Pragma No_Body,Pragma No_Elaboration_Code_All,Pragma Main_Storage,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-no-body}@anchor{83} +@section Pragma No_Body + -@node Pragma No_Body -@unnumberedsec Pragma No_Body -@findex No_Body -@noindent Syntax: -@smallexample @c ada +@example pragma No_Body; -@end smallexample +@end example -@noindent There are a number of cases in which a package spec does not require a body, and in fact a body is not permitted. GNAT will not permit the spec to be compiled if there is a body around. The pragma No_Body allows you to provide @@ -4684,57 +4800,57 @@ such a way that a body needed before is no longer needed. The provision of a dummy body with a No_Body pragma ensures that there is no interference from earlier versions of the package body. -@node Pragma No_Elaboration_Code_All -@unnumberedsec Pragma No_Elaboration_Code_All -@findex No_Elaboration_Code_All -@noindent +@node Pragma No_Elaboration_Code_All,Pragma No_Inline,Pragma No_Body,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-no-elaboration-code-all}@anchor{84} +@section Pragma No_Elaboration_Code_All + + Syntax: -@smallexample @c ada +@example pragma No_Elaboration_Code_All [(program_unit_NAME)]; -@end smallexample +@end example -@noindent This is a program unit pragma (there is also an equivalent aspect of the -same name) that establishes the restriction @code{No_Elaboration_Code} for +same name) that establishes the restriction @cite{No_Elaboration_Code} for the current unit and any extended main source units (body and subunits. It also has has the effect of enforcing a transitive application of this aspect, so that if any unit is implicitly or explicitly WITH'ed by the current unit, it must also have the No_Elaboration_Code_All aspect set. It may be applied to package or subprogram specs or their generic versions. -@node Pragma No_Inline -@unnumberedsec Pragma No_Inline -@findex No_Inline -@noindent +@node Pragma No_Inline,Pragma No_Return,Pragma No_Elaboration_Code_All,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-no-inline}@anchor{85} +@section Pragma No_Inline + + Syntax: -@smallexample @c ada +@example pragma No_Inline (NAME @{, NAME@}); -@end smallexample +@end example -@noindent This pragma suppresses inlining for the callable entity or the instances of -the generic subprogram designated by @var{NAME}, including inlining that -results from the use of pragma @code{Inline}. This pragma is always active, -in particular it is not subject to the use of option @option{-gnatn} or -@option{-gnatN}. It is illegal to specify both pragma @code{No_Inline} and -pragma @code{Inline_Always} for the same @var{NAME}. - -@node Pragma No_Return -@unnumberedsec Pragma No_Return -@findex No_Return -@noindent +the generic subprogram designated by @cite{NAME}, including inlining that +results from the use of pragma @cite{Inline}. This pragma is always active, +in particular it is not subject to the use of option @emph{-gnatn} or +@emph{-gnatN}. It is illegal to specify both pragma @cite{No_Inline} and +pragma @cite{Inline_Always} for the same @cite{NAME}. + +@node Pragma No_Return,Pragma No_Run_Time,Pragma No_Inline,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-no-return}@anchor{86} +@section Pragma No_Return + + Syntax: -@smallexample @c ada +@example pragma No_Return (procedure_LOCAL_NAME @{, procedure_LOCAL_NAME@}); -@end smallexample +@end example -@noindent -Each @var{procedure_LOCAL_NAME} argument must refer to one or more procedure +Each @cite{procedure_LOCAL_NAME} argument must refer to one or more procedure declarations in the current declarative part. A procedure to which this -pragma is applied may not contain any explicit @code{return} statements. +pragma is applied may not contain any explicit @cite{return} statements. In addition, if the procedure contains any implicit returns from falling off the end of a statement sequence, then execution of that implicit return will cause Program_Error to be raised. @@ -4748,56 +4864,56 @@ Note that in Ada 2005 mode, this pragma is part of the language. It is available in all earlier versions of Ada as an implementation-defined pragma. -@node Pragma No_Run_Time -@unnumberedsec Pragma No_Run_Time -@findex No_Run_Time -@noindent +@node Pragma No_Run_Time,Pragma No_Strict_Aliasing,Pragma No_Return,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-no-run-time}@anchor{87} +@section Pragma No_Run_Time + + Syntax: -@smallexample @c ada +@example pragma No_Run_Time; -@end smallexample +@end example -@noindent This is an obsolete configuration pragma that historically was used to set up a runtime library with no object code. It is now used only for internal testing. The pragma has been superseded by the reconfigurable -runtime capability of @code{GNAT}. +runtime capability of @cite{GNAT}. + +@node Pragma No_Strict_Aliasing,Pragma No_Tagged_Streams,Pragma No_Run_Time,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-no-strict-aliasing}@anchor{88} +@section Pragma No_Strict_Aliasing + -@node Pragma No_Strict_Aliasing -@unnumberedsec Pragma No_Strict_Aliasing -@findex No_Strict_Aliasing -@noindent Syntax: -@smallexample @c ada +@example pragma No_Strict_Aliasing [([Entity =>] type_LOCAL_NAME)]; -@end smallexample +@end example -@noindent -@var{type_LOCAL_NAME} must refer to an access type +@cite{type_LOCAL_NAME} must refer to an access type declaration in the current declarative part. The effect is to inhibit strict aliasing optimization for the given type. The form with no arguments is a configuration pragma which applies to all access types declared in units to which the pragma applies. For a detailed description of the strict aliasing optimization, and the situations -in which it must be suppressed, see @ref{Optimization and Strict -Aliasing,,, gnat_ugn, @value{EDITION} User's Guide}. +in which it must be suppressed, see the section on Optimization and Strict Aliasing +in the @cite{GNAT User's Guide}. This pragma currently has no effects on access to unconstrained array types. -@node Pragma No_Tagged_Streams -@unnumberedsec Pragma No_Tagged_Streams -@findex No_Tagged_Streams -@noindent +@node Pragma No_Tagged_Streams,Pragma Normalize_Scalars,Pragma No_Strict_Aliasing,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-no-tagged-streams}@anchor{89} +@section Pragma No_Tagged_Streams + + Syntax: -@smallexample @c ada +@example pragma No_Tagged_Streams; pragma No_Tagged_Streams [([Entity =>] tagged_type_LOCAL_NAME)]; -@end smallexample +@end example -@noindent Normally when a tagged type is introduced using a full type declaration, part of the processing includes generating stream access routines to be used by stream attributes referencing the type (or one of its subtypes @@ -4805,7 +4921,7 @@ or derived types). This can involve the generation of significant amounts of code which is wasted space if stream routines are not needed for the type in question. -The @code{No_Tagged_Streams} pragma causes the generation of these stream +The @cite{No_Tagged_Streams} pragma causes the generation of these stream routines to be skipped, and any attempt to use stream operations on types subject to this pragma will be statically rejected as illegal. @@ -4821,46 +4937,48 @@ and derived types of this type inherit the pragma automatically, so the effect applies to a complete hierarchy (this is necessary to deal with the class-wide dispatching versions of the stream routines). -@node Pragma Normalize_Scalars -@unnumberedsec Pragma Normalize_Scalars -@findex Normalize_Scalars -@noindent +@node Pragma Normalize_Scalars,Pragma Obsolescent,Pragma No_Tagged_Streams,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-normalize-scalars}@anchor{8a} +@section Pragma Normalize_Scalars + + Syntax: -@smallexample @c ada +@example pragma Normalize_Scalars; -@end smallexample +@end example -@noindent -This is a language defined pragma which is fully implemented in GNAT@. The +This is a language defined pragma which is fully implemented in GNAT. The effect is to cause all scalar objects that are not otherwise initialized to be initialized. The initial values are implementation dependent and are as follows: -@table @code -@item Standard.Character -@noindent + +@table @asis + +@item @emph{Standard.Character} + Objects whose root type is Standard.Character are initialized to Character'Last unless the subtype range excludes NUL (in which case NUL is used). This choice will always generate an invalid value if one exists. -@item Standard.Wide_Character -@noindent +@item @emph{Standard.Wide_Character} + Objects whose root type is Standard.Wide_Character are initialized to Wide_Character'Last unless the subtype range excludes NUL (in which case NUL is used). This choice will always generate an invalid value if one exists. -@item Standard.Wide_Wide_Character -@noindent +@item @emph{Standard.Wide_Wide_Character} + Objects whose root type is Standard.Wide_Wide_Character are initialized to the invalid value 16#FFFF_FFFF# unless the subtype range excludes NUL (in which case NUL is used). This choice will always generate an invalid value if one exists. -@item Integer types -@noindent +@item @emph{Integer types} + Objects of an integer type are treated differently depending on whether negative values are present in the subtype. If no negative values are present, then all one bits is used as the initial value except in the @@ -4874,37 +4992,41 @@ is in the subtype, and the largest positive number is not, in which case the largest positive value is used. This choice will always generate an invalid value if one exists. -@item Floating-Point Types +@item @emph{Floating-Point Types} + Objects of all floating-point types are initialized to all 1-bits. For standard IEEE format, this corresponds to a NaN (not a number) which is indeed an invalid value. -@item Fixed-Point Types +@item @emph{Fixed-Point Types} + Objects of all fixed-point types are treated as described above for integers, with the rules applying to the underlying integer value used to represent the fixed-point value. -@item Modular types +@item @emph{Modular types} + Objects of a modular type are initialized to all one bits, except in the special case where zero is excluded from the subtype, in which case all zero bits are used. This choice will always generate an invalid value if one exists. -@item Enumeration types -Objects of an enumeration type are initialized to all one-bits, i.e.@: to -the value @code{2 ** typ'Size - 1} unless the subtype excludes the literal +@item @emph{Enumeration types} + +Objects of an enumeration type are initialized to all one-bits, i.e., to +the value @cite{2 ** typ'Size - 1} unless the subtype excludes the literal whose Pos value is zero, in which case a code of zero is used. This choice will always generate an invalid value if one exists. - @end table -@node Pragma Obsolescent -@unnumberedsec Pragma Obsolescent -@findex Obsolescent -@noindent +@node Pragma Obsolescent,Pragma Optimize_Alignment,Pragma Normalize_Scalars,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-obsolescent}@anchor{8b}@anchor{gnat_rm/implementation_defined_pragmas id2}@anchor{8c} +@section Pragma Obsolescent + + Syntax: -@smallexample @c ada +@example pragma Obsolescent; pragma Obsolescent ( @@ -4915,9 +5037,8 @@ pragma Obsolescent ( [Entity =>] NAME [,[Message =>] static_string_EXPRESSION [,[Version =>] Ada_05]] ); -@end smallexample +@end example -@noindent This pragma can occur immediately following a declaration of an entity, including the case of a record component. If no Entity argument is present, then this declaration is the one to which the pragma applies. If an Entity @@ -4943,8 +5064,8 @@ Restrictions (No_Obsolescent_Features). This pragma can also be used as a program unit pragma for a package, in which case the entity name is the name of the package, and the pragma indicates that the entire package is considered -obsolescent. In this case a client @code{with}'ing such a package -violates the restriction, and the @code{with} statement is +obsolescent. In this case a client @cite{with}'ing such a package +violates the restriction, and the @cite{with} statement is flagged with warnings if the warning option is set. If the Version parameter is present (which must be exactly @@ -4953,11 +5074,11 @@ indication of obsolescence applies only when compiling in Ada 2005 mode. This is primarily intended for dealing with the situations in the predefined library where subprograms or packages have become defined as obsolescent in Ada 2005 -(e.g.@: in Ada.Characters.Handling), but may be used anywhere. +(e.g., in Ada.Characters.Handling), but may be used anywhere. The following examples show typical uses of this pragma: -@smallexample @c ada +@example package p is pragma Obsolescent (p, Message => "use pp instead of p"); end p; @@ -4987,26 +5108,27 @@ package q is (a, b : character) return character; pragma Obsolescent (Entity => "+"); end; -@end smallexample +@end example -@noindent Note that, as for all pragmas, if you use a pragma argument identifier, then all subsequent parameters must also use a pragma argument identifier. So if you specify "Entity =>" for the Entity argument, and a Message argument is present, it must be preceded by "Message =>". -@node Pragma Optimize_Alignment -@unnumberedsec Pragma Optimize_Alignment -@findex Optimize_Alignment -@cindex Alignment, default settings -@noindent +@node Pragma Optimize_Alignment,Pragma Ordered,Pragma Obsolescent,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-optimize-alignment}@anchor{8d} +@section Pragma Optimize_Alignment + + +@geindex Alignment +@geindex default settings + Syntax: -@smallexample @c ada +@example pragma Optimize_Alignment (TIME | SPACE | OFF); -@end smallexample +@end example -@noindent This is a configuration pragma which affects the choice of default alignments for types and objects where no alignment is explicitly specified. There is a time/space trade-off in the selection of these values. Large alignments result @@ -5022,22 +5144,21 @@ First any packed record is given an alignment of 1. Second, if a size is given for the type, then the alignment is chosen to avoid increasing this size. For example, consider: -@smallexample @c ada - type R is record - X : Integer; - Y : Character; - end record; +@example +type R is record + X : Integer; + Y : Character; +end record; - for R'Size use 5*8; -@end smallexample +for R'Size use 5*8; +@end example -@noindent In the default mode, this type gets an alignment of 4, so that access to the Integer field X are efficient. But this means that objects of the type end up with a size of 8 bytes. This is a valid choice, since sizes of objects are allowed to be bigger than the size of the type, but it can waste space if for example fields of type R appear in an enclosing record. If the above type is -compiled in @code{Optimize_Alignment (Space)} mode, the alignment is set to 1. +compiled in @cite{Optimize_Alignment (Space)} mode, the alignment is set to 1. However, there is one case in which SPACE is ignored. If a variable length record (that is a discriminated record with a component which is an array @@ -5052,20 +5173,19 @@ without changing the alignment of its type. Specifying TIME causes larger default alignments to be chosen in the case of small types with sizes that are not a power of 2. For example, consider: -@smallexample @c ada - type R is record - A : Character; - B : Character; - C : Boolean; - end record; +@example +type R is record + A : Character; + B : Character; + C : Boolean; +end record; - pragma Pack (R); - for R'Size use 17; -@end smallexample +pragma Pack (R); +for R'Size use 17; +@end example -@noindent The default alignment for this record is normally 1, but if this type is -compiled in @code{Optimize_Alignment (Time)} mode, then the alignment is set +compiled in @cite{Optimize_Alignment (Time)} mode, then the alignment is set to 4, which wastes space for objects of the type, since they are now 4 bytes long, but results in more efficient access when the whole record is referenced. @@ -5078,27 +5198,25 @@ unit are excluded from the consistency check, as are all predefined units. The latter are compiled by default in pragma Optimize_Alignment (Off) mode if no pragma appears at the start of the file. -@node Pragma Ordered -@unnumberedsec Pragma Ordered -@findex Ordered -@findex pragma @code{Ordered} -@noindent +@node Pragma Ordered,Pragma Overflow_Mode,Pragma Optimize_Alignment,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-ordered}@anchor{8e} +@section Pragma Ordered + + Syntax: -@smallexample @c ada +@example pragma Ordered (enumeration_first_subtype_LOCAL_NAME); -@end smallexample +@end example -@noindent Most enumeration types are from a conceptual point of view unordered. For example, consider: -@smallexample @c ada +@example type Color is (Red, Blue, Green, Yellow); -@end smallexample +@end example -@noindent -By Ada semantics @code{Blue > Red} and @code{Green > Blue}, +By Ada semantics @cite{Blue > Red} and @cite{Green > Blue}, but really these relations make no sense; the enumeration type merely specifies a set of possible colors, and the order is unimportant. @@ -5108,66 +5226,61 @@ explicit ranges. (A @emph{client} is a unit where the type is referenced, other than the unit where the type is declared, its body, and its subunits.) For example, if code buried in some client says: -@smallexample @c ada +@example if Current_Color < Yellow then ... if Current_Color in Blue .. Green then ... -@end smallexample +@end example -@noindent then the client code is relying on the order, which is undesirable. It makes the code hard to read and creates maintenance difficulties if entries have to be added to the enumeration type. Instead, the code in the client should list the possibilities, or an appropriate subtype should be declared in the unit that declares the original enumeration type. E.g., the following subtype could -be declared along with the type @code{Color}: +be declared along with the type @cite{Color}: -@smallexample @c ada +@example subtype RBG is Color range Red .. Green; -@end smallexample +@end example -@noindent and then the client could write: -@smallexample @c ada +@example if Current_Color in RBG then ... if Current_Color = Blue or Current_Color = Green then ... -@end smallexample +@end example -@noindent However, some enumeration types are legitimately ordered from a conceptual point of view. For example, if you declare: -@smallexample @c ada +@example type Day is (Mon, Tue, Wed, Thu, Fri, Sat, Sun); -@end smallexample +@end example -@noindent then the ordering imposed by the language is reasonable, and clients can depend on it, writing for example: -@smallexample @c ada +@example if D in Mon .. Fri then ... if D < Wed then ... -@end smallexample +@end example -@noindent -The pragma @option{Ordered} is provided to mark enumeration types that +The pragma @emph{Ordered} is provided to mark enumeration types that are conceptually ordered, alerting the reader that clients may depend on the ordering. GNAT provides a pragma to mark enumerations as ordered rather than one to mark them as unordered, since in our experience, the great majority of enumeration types are conceptually unordered. -The types @code{Boolean}, @code{Character}, @code{Wide_Character}, -and @code{Wide_Wide_Character} +The types @cite{Boolean}, @cite{Character}, @cite{Wide_Character}, +and @cite{Wide_Wide_Character} are considered to be ordered types, so each is declared with a -pragma @code{Ordered} in package @code{Standard}. +pragma @cite{Ordered} in package @cite{Standard}. -Normally pragma @code{Ordered} serves only as documentation and a guide for -coding standards, but GNAT provides a warning switch @option{-gnatw.u} that +Normally pragma @cite{Ordered} serves only as documentation and a guide for +coding standards, but GNAT provides a warning switch @emph{-gnatw.u} that requests warnings for inappropriate uses (comparisons and explicit subranges) for unordered types. If this switch is used, then any -enumeration type not marked with pragma @code{Ordered} will be considered +enumeration type not marked with pragma @cite{Ordered} will be considered as unordered, and will generate warnings for inappropriate uses. Note that generic types are not considered ordered or unordered (since the @@ -5175,69 +5288,69 @@ template can be instantiated for both cases), so we never generate warnings for the case of generic enumerated types. For additional information please refer to the description of the -@option{-gnatw.u} switch in the @value{EDITION} User's Guide. - -@node Pragma Overflow_Mode -@unnumberedsec Pragma Overflow_Mode -@findex Overflow checks -@findex Overflow mode -@findex pragma @code{Overflow_Mode} -@noindent +@emph{-gnatw.u} switch in the GNAT User's Guide. + +@node Pragma Overflow_Mode,Pragma Overriding_Renamings,Pragma Ordered,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-overflow-mode}@anchor{8f} +@section Pragma Overflow_Mode + + Syntax: -@smallexample @c ada +@example pragma Overflow_Mode ( [General =>] MODE [,[Assertions =>] MODE]); MODE ::= STRICT | MINIMIZED | ELIMINATED -@end smallexample +@end example -@noindent This pragma sets the current overflow mode to the given setting. For details of the meaning of these modes, please refer to the -``Overflow Check Handling in GNAT'' appendix in the -@value{EDITION} User's Guide. If only the @code{General} parameter is present, +'Overflow Check Handling in GNAT' appendix in the +GNAT User's Guide. If only the @cite{General} parameter is present, the given mode applies to all expressions. If both parameters are present, -the @code{General} mode applies to expressions outside assertions, and -the @code{Eliminated} mode applies to expressions within assertions. +the @cite{General} mode applies to expressions outside assertions, and +the @cite{Eliminated} mode applies to expressions within assertions. -The case of the @code{MODE} parameter is ignored, -so @code{MINIMIZED}, @code{Minimized} and -@code{minimized} all have the same effect. +The case of the @cite{MODE} parameter is ignored, +so @cite{MINIMIZED}, @cite{Minimized} and +@cite{minimized} all have the same effect. -The @code{Overflow_Mode} pragma has the same scoping and placement -rules as pragma @code{Suppress}, so it can occur either as a +The @cite{Overflow_Mode} pragma has the same scoping and placement +rules as pragma @cite{Suppress}, so it can occur either as a configuration pragma, specifying a default for the whole program, or in a declarative scope, where it applies to the remaining declarations and statements in that scope. -The pragma @code{Suppress (Overflow_Check)} suppresses +The pragma @cite{Suppress (Overflow_Check)} suppresses overflow checking, but does not affect the overflow mode. -The pragma @code{Unsuppress (Overflow_Check)} unsuppresses (enables) +The pragma @cite{Unsuppress (Overflow_Check)} unsuppresses (enables) overflow checking, but does not affect the overflow mode. -@node Pragma Overriding_Renamings -@unnumberedsec Pragma Overriding_Renamings -@findex Overriding_Renamings -@cindex Rational profile -@cindex Rational compatibility -@noindent +@node Pragma Overriding_Renamings,Pragma Partition_Elaboration_Policy,Pragma Overflow_Mode,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-overriding-renamings}@anchor{90} +@section Pragma Overriding_Renamings + + +@geindex Rational profile + +@geindex Rational compatibility + Syntax: -@smallexample @c ada +@example pragma Overriding_Renamings; -@end smallexample +@end example -@noindent This is a GNAT configuration pragma to simplify porting legacy code accepted by the Rational Ada compiler. In the presence of this pragma, a renaming declaration that renames an inherited operation declared in the same scope is legal if selected notation is used as in: -@smallexample @c ada +@example pragma Overriding_Renamings; ... package R is @@ -5245,72 +5358,73 @@ package R is ... function F (..) renames R.F; end R; -@end smallexample +@end example even though RM 8.3 (15) stipulates that an overridden operation is not visible within the declaration of the overriding operation. -@node Pragma Partition_Elaboration_Policy -@unnumberedsec Pragma Partition_Elaboration_Policy -@findex Partition_Elaboration_Policy -@noindent +@node Pragma Partition_Elaboration_Policy,Pragma Part_Of,Pragma Overriding_Renamings,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-partition-elaboration-policy}@anchor{91} +@section Pragma Partition_Elaboration_Policy + + Syntax: -@smallexample @c ada +@example pragma Partition_Elaboration_Policy (POLICY_IDENTIFIER); POLICY_IDENTIFIER ::= Concurrent | Sequential -@end smallexample +@end example -@noindent This pragma is standard in Ada 2005, but is available in all earlier versions of Ada as an implementation-defined pragma. See Ada 2012 Reference Manual for details. -@node Pragma Part_Of -@unnumberedsec Pragma Part_Of -@findex Part_Of -@noindent +@node Pragma Part_Of,Pragma Passive,Pragma Partition_Elaboration_Policy,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-part-of}@anchor{92} +@section Pragma Part_Of + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.2.6. -@node Pragma Passive -@unnumberedsec Pragma Passive -@findex Passive -@noindent +@node Pragma Passive,Pragma Persistent_BSS,Pragma Part_Of,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-passive}@anchor{93} +@section Pragma Passive + + Syntax: -@smallexample @c ada +@example pragma Passive [(Semaphore | No)]; -@end smallexample +@end example -@noindent -Syntax checked, but otherwise ignored by GNAT@. This is recognized for +Syntax checked, but otherwise ignored by GNAT. This is recognized for compatibility with DEC Ada 83 implementations, where it is used within a task definition to request that a task be made passive. If the argument -@code{Semaphore} is present, or the argument is omitted, then DEC Ada 83 +@cite{Semaphore} is present, or the argument is omitted, then DEC Ada 83 treats the pragma as an assertion that the containing task is passive and that optimization of context switch with this task is permitted and -desired. If the argument @code{No} is present, the task must not be +desired. If the argument @cite{No} is present, the task must not be optimized. GNAT does not attempt to optimize any tasks in this manner (since protected objects are available in place of passive tasks). For more information on the subject of passive tasks, see the section -``Passive Task Optimization'' in the GNAT Users Guide. +'Passive Task Optimization' in the GNAT Users Guide. + +@node Pragma Persistent_BSS,Pragma Polling,Pragma Passive,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-persistent-bss}@anchor{94} +@section Pragma Persistent_BSS + -@node Pragma Persistent_BSS -@unnumberedsec Pragma Persistent_BSS -@findex Persistent_BSS -@noindent Syntax: -@smallexample @c ada +@example pragma Persistent_BSS [(LOCAL_NAME)] -@end smallexample +@end example -@noindent -This pragma allows selected objects to be placed in the @code{.persistent_bss} +This pragma allows selected objects to be placed in the @cite{.persistent_bss} section. On some targets the linker and loader provide for special treatment of this section, allowing a program to be reloaded without affecting the contents of this data (hence the name persistent). @@ -5328,89 +5442,94 @@ or an array, all of whose constraints are static, and whose component type is potentially persistent. If this pragma is used on a target where this feature is not supported, -then the pragma will be ignored. See also @code{pragma Linker_Section}. +then the pragma will be ignored. See also @cite{pragma Linker_Section}. + +@node Pragma Polling,Pragma Post,Pragma Persistent_BSS,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-polling}@anchor{95} +@section Pragma Polling + -@node Pragma Polling -@unnumberedsec Pragma Polling -@findex Polling -@noindent Syntax: -@smallexample @c ada +@example pragma Polling (ON | OFF); -@end smallexample +@end example -@noindent This pragma controls the generation of polling code. This is normally off. -If @code{pragma Polling (ON)} is used then periodic calls are generated to -the routine @code{Ada.Exceptions.Poll}. This routine is a separate unit in the -runtime library, and can be found in file @file{a-excpol.adb}. +If @cite{pragma Polling (ON)} is used then periodic calls are generated to +the routine @cite{Ada.Exceptions.Poll}. This routine is a separate unit in the +runtime library, and can be found in file @code{a-excpol.adb}. -Pragma @code{Polling} can appear as a configuration pragma (for example it -can be placed in the @file{gnat.adc} file) to enable polling globally, or it +Pragma @cite{Polling} can appear as a configuration pragma (for example it +can be placed in the @code{gnat.adc} file) to enable polling globally, or it can be used in the statement or declaration sequence to control polling more locally. A call to the polling routine is generated at the start of every loop and -at the start of every subprogram call. This guarantees that the @code{Poll} +at the start of every subprogram call. This guarantees that the @cite{Poll} routine is called frequently, and places an upper bound (determined by -the complexity of the code) on the period between two @code{Poll} calls. +the complexity of the code) on the period between two @cite{Poll} calls. The primary purpose of the polling interface is to enable asynchronous aborts on targets that cannot otherwise support it (for example Windows NT), but it may be used for any other purpose requiring periodic polling. The standard version is null, and can be replaced by a user program. This -will require re-compilation of the @code{Ada.Exceptions} package that can -be found in files @file{a-except.ads} and @file{a-except.adb}. +will require re-compilation of the @cite{Ada.Exceptions} package that can +be found in files @code{a-except.ads} and @code{a-except.adb}. -A standard alternative unit (in file @file{4wexcpol.adb} in the standard GNAT +A standard alternative unit (in file @code{4wexcpol.adb} in the standard GNAT distribution) is used to enable the asynchronous abort capability on targets that do not normally support the capability. The version of -@code{Poll} in this file makes a call to the appropriate runtime routine +@cite{Poll} in this file makes a call to the appropriate runtime routine to test for an abort condition. -Note that polling can also be enabled by use of the @option{-gnatP} switch. -@xref{Switches for gcc,,, gnat_ugn, @value{EDITION} User's Guide}, for -details. +Note that polling can also be enabled by use of the @emph{-gnatP} switch. +See the section on switches for gcc in the @cite{GNAT User's Guide}. + +@node Pragma Post,Pragma Postcondition,Pragma Polling,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-post}@anchor{96} +@section Pragma Post + + +@geindex Post + +@geindex Checks +@geindex postconditions -@node Pragma Post -@unnumberedsec Pragma Post -@cindex Post -@cindex Checks, postconditions -@findex Postconditions -@noindent Syntax: -@smallexample @c ada +@example pragma Post (Boolean_Expression); -@end smallexample +@end example -@noindent -The @code{Post} pragma is intended to be an exact replacement for +The @cite{Post} pragma is intended to be an exact replacement for the language-defined -@code{Post} aspect, and shares its restrictions and semantics. +@cite{Post} aspect, and shares its restrictions and semantics. It must appear either immediately following the corresponding subprogram declaration (only other pragmas may intervene), or if there is no separate subprogram declaration, then it can appear at the start of the declarations in a subprogram body (preceded only by other pragmas). -@node Pragma Postcondition -@unnumberedsec Pragma Postcondition -@cindex Postcondition -@cindex Checks, postconditions -@findex Postconditions -@noindent +@node Pragma Postcondition,Pragma Post_Class,Pragma Post,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-postcondition}@anchor{97} +@section Pragma Postcondition + + +@geindex Postcondition + +@geindex Checks +@geindex postconditions + Syntax: -@smallexample @c ada +@example pragma Postcondition ( [Check =>] Boolean_Expression [,[Message =>] String_Expression]); -@end smallexample +@end example -@noindent -The @code{Postcondition} pragma allows specification of automatic +The @cite{Postcondition} pragma allows specification of automatic postcondition checks for subprograms. These checks are similar to assertions, but are automatically inserted just prior to the return statements of the subprogram with which they are associated (including @@ -5421,7 +5540,7 @@ In addition, the boolean expression which is the condition which must be true may contain references to function'Result in the case of a function to refer to the returned value. -@code{Postcondition} pragmas may appear either immediately following the +@cite{Postcondition} pragmas may appear either immediately following the (separate) declaration of a subprogram, or at the start of the declarations of a subprogram body. Only other pragmas may intervene (that is appear between the subprogram declaration and its @@ -5434,24 +5553,23 @@ referenced in the postcondition expressions. The postconditions are collected and automatically tested just before any return (implicit or explicit) in the subprogram body. A postcondition is only recognized if postconditions are active -at the time the pragma is encountered. The compiler switch @option{gnata} -turns on all postconditions by default, and pragma @code{Check_Policy} -with an identifier of @code{Postcondition} can also be used to +at the time the pragma is encountered. The compiler switch @emph{gnata} +turns on all postconditions by default, and pragma @cite{Check_Policy} +with an identifier of @cite{Postcondition} can also be used to control whether postconditions are active. The general approach is that postconditions are placed in the spec if they represent functional aspects which make sense to the client. For example we might have: -@smallexample @c ada - function Direction return Integer; - pragma Postcondition - (Direction'Result = +1 - or else - Direction'Result = -1); -@end smallexample +@example +function Direction return Integer; +pragma Postcondition + (Direction'Result = +1 + or else + Direction'Result = -1); +@end example -@noindent which serves to document that the result must be +1 or -1, and will test that this is the case at run time if postcondition checking is active. @@ -5463,18 +5581,17 @@ For instance if a square root routine keeps an internal counter of the number of times it is called, then we might have the following postcondition: -@smallexample @c ada - Sqrt_Calls : Natural := 0; +@example +Sqrt_Calls : Natural := 0; - function Sqrt (Arg : Float) return Float is - pragma Postcondition - (Sqrt_Calls = Sqrt_Calls'Old + 1); - ... - end Sqrt -@end smallexample +function Sqrt (Arg : Float) return Float is + pragma Postcondition + (Sqrt_Calls = Sqrt_Calls'Old + 1); + ... +end Sqrt +@end example -@noindent -As this example, shows, the use of the @code{Old} attribute +As this example, shows, the use of the @cite{Old} attribute is often useful in postconditions to refer to the state on entry to the subprogram. @@ -5483,11 +5600,11 @@ from the subprogram. If an abnormal return results from raising an exception, then the postconditions are not checked. If a postcondition fails, then the exception -@code{System.Assertions.Assert_Failure} is raised. If +@cite{System.Assertions.Assert_Failure} is raised. If a message argument was supplied, then the given string will be used as the exception message. If no message argument was supplied, then the default message has -the form "Postcondition failed at file:line". The +the form "Postcondition failed at file_name:line". The exception is raised in the context of the subprogram body, so it is possible to catch postcondition failures within the subprogram body itself. @@ -5503,7 +5620,7 @@ the package spec, allowing forward references. The following example shows that this even allows mutually recursive postconditions as in: -@smallexample @c ada +@example package Parity_Functions is function Odd (X : Natural) return Boolean; pragma Postcondition @@ -5520,15 +5637,14 @@ package Parity_Functions is (x /= 1 and then Odd (X - 1)))); end Parity_Functions; -@end smallexample +@end example -@noindent There are no restrictions on the complexity or form of -conditions used within @code{Postcondition} pragmas. +conditions used within @cite{Postcondition} pragmas. The following example shows that it is even possible to verify performance behavior. -@smallexample @c ada +@example package Sort is Performance : constant Float; @@ -5543,94 +5659,102 @@ package Sort is log (Float (Arg'Length)) * Performance); end Sort; -@end smallexample +@end example -@noindent Note: postcondition pragmas associated with subprograms that are marked as Inline_Always, or those marked as Inline with front-end inlining (-gnatN option set) are accepted and legality-checked by the compiler, but are ignored at run-time even if postcondition checking is enabled. -Note that pragma @code{Postcondition} differs from the language-defined -@code{Post} aspect (and corresponding @code{Post} pragma) in allowing +Note that pragma @cite{Postcondition} differs from the language-defined +@cite{Post} aspect (and corresponding @cite{Post} pragma) in allowing multiple occurrences, allowing occurences in the body even if there is a separate spec, and allowing a second string parameter, and the -use of the pragma identifier @code{Check}. Historically, pragma -@code{Postcondition} was implemented prior to the development of +use of the pragma identifier @cite{Check}. Historically, pragma +@cite{Postcondition} was implemented prior to the development of Ada 2012, and has been retained in its original form for compatibility purposes. -@node Pragma Post_Class -@unnumberedsec Pragma Post_Class -@cindex Post -@cindex Checks, postconditions -@findex Postconditions -@noindent +@node Pragma Post_Class,Pragma Pre,Pragma Postcondition,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-post-class}@anchor{98} +@section Pragma Post_Class + + +@geindex Post + +@geindex Checks +@geindex postconditions + Syntax: -@smallexample @c ada +@example pragma Post_Class (Boolean_Expression); -@end smallexample +@end example -@noindent -The @code{Post_Class} pragma is intended to be an exact replacement for +The @cite{Post_Class} pragma is intended to be an exact replacement for the language-defined -@code{Post'Class} aspect, and shares its restrictions and semantics. +@cite{Post'Class} aspect, and shares its restrictions and semantics. It must appear either immediately following the corresponding subprogram declaration (only other pragmas may intervene), or if there is no separate subprogram declaration, then it can appear at the start of the declarations in a subprogram body (preceded only by other pragmas). -Note: This pragma is called @code{Post_Class} rather than -@code{Post'Class} because the latter would not be strictly +Note: This pragma is called @cite{Post_Class} rather than +@cite{Post'Class} because the latter would not be strictly conforming to the allowed syntax for pragmas. The motivation for provinding pragmas equivalent to the aspects is to allow a program to be written using the pragmas, and then compiled if necessary using an Ada compiler that does not recognize the pragmas or aspects, but is prepared to ignore the pragmas. The assertion -policy that controls this pragma is @code{Post'Class}, not -@code{Post_Class}. - -@node Pragma Pre -@unnumberedsec Pragma Pre -@cindex Pre -@cindex Checks, preconditions -@findex Preconditions -@noindent +policy that controls this pragma is @cite{Post'Class}, not +@cite{Post_Class}. + +@node Pragma Pre,Pragma Precondition,Pragma Post_Class,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-pre}@anchor{99} +@section Pragma Pre + + +@geindex Pre + +@geindex Checks +@geindex preconditions + Syntax: -@smallexample @c ada +@example pragma Pre (Boolean_Expression); -@end smallexample +@end example -@noindent -The @code{Pre} pragma is intended to be an exact replacement for +The @cite{Pre} pragma is intended to be an exact replacement for the language-defined -@code{Pre} aspect, and shares its restrictions and semantics. +@cite{Pre} aspect, and shares its restrictions and semantics. It must appear either immediately following the corresponding subprogram declaration (only other pragmas may intervene), or if there is no separate subprogram declaration, then it can appear at the start of the declarations in a subprogram body (preceded only by other pragmas). -@node Pragma Precondition -@unnumberedsec Pragma Precondition -@cindex Preconditions -@cindex Checks, preconditions -@findex Preconditions -@noindent +@node Pragma Precondition,Pragma Predicate,Pragma Pre,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-precondition}@anchor{9a} +@section Pragma Precondition + + +@geindex Preconditions + +@geindex Checks +@geindex preconditions + Syntax: -@smallexample @c ada +@example pragma Precondition ( [Check =>] Boolean_Expression [,[Message =>] String_Expression]); -@end smallexample +@end example -@noindent -The @code{Precondition} pragma is similar to @code{Postcondition} +The @cite{Precondition} pragma is similar to @cite{Postcondition} except that the corresponding checks take place immediately upon entry to the subprogram, and if a precondition fails, the exception is raised in the context of the caller, and the attribute 'Result @@ -5640,17 +5764,16 @@ Otherwise, the placement and visibility rules are identical to those described for postconditions. The following is an example of use within a package spec: -@smallexample @c ada +@example package Math_Functions is ... function Sqrt (Arg : Float) return Float; pragma Precondition (Arg >= 0.0) ... end Math_Functions; -@end smallexample +@end example -@noindent -@code{Precondition} pragmas may appear either immediately following the +@cite{Precondition} pragmas may appear either immediately following the (separate) declaration of a subprogram, or at the start of the declarations of a subprogram body. Only other pragmas may intervene (that is appear between the subprogram declaration and its @@ -5663,58 +5786,56 @@ inlining (-gnatN option set) are accepted and legality-checked by the compiler, but are ignored at run-time even if precondition checking is enabled. -Note that pragma @code{Precondition} differs from the language-defined -@code{Pre} aspect (and corresponding @code{Pre} pragma) in allowing +Note that pragma @cite{Precondition} differs from the language-defined +@cite{Pre} aspect (and corresponding @cite{Pre} pragma) in allowing multiple occurrences, allowing occurences in the body even if there is a separate spec, and allowing a second string parameter, and the -use of the pragma identifier @code{Check}. Historically, pragma -@code{Precondition} was implemented prior to the development of +use of the pragma identifier @cite{Check}. Historically, pragma +@cite{Precondition} was implemented prior to the development of Ada 2012, and has been retained in its original form for compatibility purposes. -@node Pragma Predicate -@unnumberedsec Pragma Predicate -@findex Predicate -@findex Predicate pragma -@noindent +@node Pragma Predicate,Pragma Preelaborable_Initialization,Pragma Precondition,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-predicate}@anchor{9b} +@section Pragma Predicate + + Syntax: -@smallexample @c ada +@example pragma Predicate ([Entity =>] type_LOCAL_NAME, [Check =>] EXPRESSION); -@end smallexample +@end example -@noindent This pragma (available in all versions of Ada in GNAT) encompasses both -the @code{Static_Predicate} and @code{Dynamic_Predicate} aspects in +the @cite{Static_Predicate} and @cite{Dynamic_Predicate} aspects in Ada 2012. A predicate is regarded as static if it has an allowed form -for @code{Static_Predicate} and is otherwise treated as a -@code{Dynamic_Predicate}. Otherwise, predicates specified by this +for @cite{Static_Predicate} and is otherwise treated as a +@cite{Dynamic_Predicate}. Otherwise, predicates specified by this pragma behave exactly as described in the Ada 2012 reference manual. For example, if we have -@smallexample @c ada +@example type R is range 1 .. 10; subtype S is R; pragma Predicate (Entity => S, Check => S not in 4 .. 6); subtype Q is R pragma Predicate (Entity => Q, Check => F(Q) or G(Q)); -@end smallexample +@end example -@noindent the effect is identical to the following Ada 2012 code: -@smallexample @c ada +@example type R is range 1 .. 10; subtype S is R with Static_Predicate => S not in 4 .. 6; subtype Q is R with Dynamic_Predicate => F(Q) or G(Q); -@end smallexample +@end example -Note that there is are no pragmas @code{Dynamic_Predicate} -or @code{Static_Predicate}. That is +Note that there is are no pragmas @cite{Dynamic_Predicate} +or @cite{Static_Predicate}. That is because these pragmas would affect legality and semantics of the program and thus do not have a neutral effect if ignored. The motivation behind providing pragmas equivalent to @@ -5724,39 +5845,42 @@ will ignore the pragmas. That doesn't work in the case of static and dynamic predicates, since if the corresponding pragmas are ignored, then the behavior of the program is fundamentally changed (for example a membership test -@code{A in B} would not take into account a predicate +@cite{A in B} would not take into account a predicate defined for subtype B). When following this approach, the use of predicates should be avoided. -@node Pragma Preelaborable_Initialization -@unnumberedsec Pragma Preelaborable_Initialization -@findex Preelaborable_Initialization -@noindent +@node Pragma Preelaborable_Initialization,Pragma Prefix_Exception_Messages,Pragma Predicate,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-preelaborable-initialization}@anchor{9c} +@section Pragma Preelaborable_Initialization + + Syntax: -@smallexample @c ada +@example pragma Preelaborable_Initialization (DIRECT_NAME); -@end smallexample +@end example -@noindent This pragma is standard in Ada 2005, but is available in all earlier versions of Ada as an implementation-defined pragma. See Ada 2012 Reference Manual for details. -@node Pragma Prefix_Exception_Messages -@unnumberedsec Pragma Prefix_Exception_Messages -@cindex Prefix_Exception_Messages -@cindex exception -@cindex Exception_Message -@findex Exceptions -@noindent +@node Pragma Prefix_Exception_Messages,Pragma Pre_Class,Pragma Preelaborable_Initialization,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-prefix-exception-messages}@anchor{9d} +@section Pragma Prefix_Exception_Messages + + +@geindex Prefix_Exception_Messages + +@geindex exception + +@geindex Exception_Message + Syntax: -@smallexample @c ada +@example pragma Prefix_Exception_Messages; -@end smallexample +@end example -@noindent This is an implementation-defined configuration pragma that affects the behavior of raise statements with a message given as a static string constant (typically a string literal). In such cases, the string will @@ -5769,47 +5893,51 @@ The pragma has no effect if the message is computed with an expression other than a static string constant, since the assumption in this case is that the program computes exactly the string it wants. If you still want the prefixing in this case, you can always call -@code{GNAT.Source_Info.Enclosing_Entity} and prepend the string manually. - -@node Pragma Pre_Class -@unnumberedsec Pragma Pre_Class -@cindex Pre_Class -@cindex Checks, preconditions -@findex Preconditions -@noindent +@cite{GNAT.Source_Info.Enclosing_Entity} and prepend the string manually. + +@node Pragma Pre_Class,Pragma Priority_Specific_Dispatching,Pragma Prefix_Exception_Messages,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-pre-class}@anchor{9e} +@section Pragma Pre_Class + + +@geindex Pre_Class + +@geindex Checks +@geindex preconditions + Syntax: -@smallexample @c ada +@example pragma Pre_Class (Boolean_Expression); -@end smallexample +@end example -@noindent -The @code{Pre_Class} pragma is intended to be an exact replacement for +The @cite{Pre_Class} pragma is intended to be an exact replacement for the language-defined -@code{Pre'Class} aspect, and shares its restrictions and semantics. +@cite{Pre'Class} aspect, and shares its restrictions and semantics. It must appear either immediately following the corresponding subprogram declaration (only other pragmas may intervene), or if there is no separate subprogram declaration, then it can appear at the start of the declarations in a subprogram body (preceded only by other pragmas). -Note: This pragma is called @code{Pre_Class} rather than -@code{Pre'Class} because the latter would not be strictly +Note: This pragma is called @cite{Pre_Class} rather than +@cite{Pre'Class} because the latter would not be strictly conforming to the allowed syntax for pragmas. The motivation for providing pragmas equivalent to the aspects is to allow a program to be written using the pragmas, and then compiled if necessary using an Ada compiler that does not recognize the pragmas or aspects, but is prepared to ignore the pragmas. The assertion -policy that controls this pragma is @code{Pre'Class}, not -@code{Pre_Class}. +policy that controls this pragma is @cite{Pre'Class}, not +@cite{Pre_Class}. + +@node Pragma Priority_Specific_Dispatching,Pragma Profile,Pragma Pre_Class,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-priority-specific-dispatching}@anchor{9f} +@section Pragma Priority_Specific_Dispatching + -@node Pragma Priority_Specific_Dispatching -@unnumberedsec Pragma Priority_Specific_Dispatching -@findex Priority_Specific_Dispatching -@noindent Syntax: -@smallexample @c ada +@example pragma Priority_Specific_Dispatching ( POLICY_IDENTIFIER, first_priority_EXPRESSION, @@ -5820,114 +5948,169 @@ POLICY_IDENTIFIER ::= FIFO_Within_Priorities | Non_Preemptive_Within_Priorities | Round_Robin_Within_Priorities -@end smallexample +@end example -@noindent This pragma is standard in Ada 2005, but is available in all earlier versions of Ada as an implementation-defined pragma. See Ada 2012 Reference Manual for details. -@node Pragma Profile -@unnumberedsec Pragma Profile -@findex Profile -@noindent +@node Pragma Profile,Pragma Profile_Warnings,Pragma Priority_Specific_Dispatching,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-profile}@anchor{a0} +@section Pragma Profile + + Syntax: -@smallexample @c ada +@example pragma Profile (Ravenscar | Restricted | Rational); -@end smallexample +@end example -@noindent This pragma is standard in Ada 2005, but is available in all earlier versions of Ada as an implementation-defined pragma. This is a -configuration pragma that establishes a set of configiuration pragmas -that depend on the argument. @code{Ravenscar} is standard in Ada 2005. -The other two possibilities (@code{Restricted} or @code{Rational}) +configuration pragma that establishes a set of configuration pragmas +that depend on the argument. @cite{Ravenscar} is standard in Ada 2005. +The other two possibilities (@cite{Restricted} or @cite{Rational}) are implementation-defined. The set of configuration pragmas is defined in the following sections. -@itemize -@item Pragma Profile (Ravenscar) -@findex Ravenscar -@noindent +@itemize * + +@item +Pragma Profile (Ravenscar) -The @code{Ravenscar} profile is standard in Ada 2005, +The @cite{Ravenscar} profile is standard in Ada 2005, but is available in all earlier versions of Ada as an implementation-defined pragma. This profile establishes the following set of configuration pragmas: -@table @code -@item Task_Dispatching_Policy (FIFO_Within_Priorities) + +@itemize * + +@item +@code{Task_Dispatching_Policy (FIFO_Within_Priorities)} + [RM D.2.2] Tasks are dispatched following a preemptive priority-ordered scheduling policy. -@item Locking_Policy (Ceiling_Locking) +@item +@code{Locking_Policy (Ceiling_Locking)} + [RM D.3] While tasks and interrupts execute a protected action, they inherit the ceiling priority of the corresponding protected object. -@item Detect_Blocking +@item +@code{Detect_Blocking} + This pragma forces the detection of potentially blocking operations within a protected operation, and to raise Program_Error if that happens. -@end table -@noindent +@end itemize plus the following set of restrictions: -@table @code -@item Max_Entry_Queue_Length => 1 + +@itemize * + +@item +@code{Max_Entry_Queue_Length => 1} + No task can be queued on a protected entry. -@item Max_Protected_Entries => 1 -@item Max_Task_Entries => 0 + +@item +@code{Max_Protected_Entries => 1} + +@item +@code{Max_Task_Entries => 0} + No rendezvous statements are allowed. -@item No_Abort_Statements -@item No_Dynamic_Attachment -@item No_Dynamic_Priorities -@item No_Implicit_Heap_Allocations -@item No_Local_Protected_Objects -@item No_Local_Timing_Events -@item No_Protected_Type_Allocators -@item No_Relative_Delay -@item No_Requeue_Statements -@item No_Select_Statements -@item No_Specific_Termination_Handlers -@item No_Task_Allocators -@item No_Task_Hierarchy -@item No_Task_Termination -@item Simple_Barriers -@end table -@noindent + +@item +@code{No_Abort_Statements} + +@item +@code{No_Dynamic_Attachment} + +@item +@code{No_Dynamic_Priorities} + +@item +@code{No_Implicit_Heap_Allocations} + +@item +@code{No_Local_Protected_Objects} + +@item +@code{No_Local_Timing_Events} + +@item +@code{No_Protected_Type_Allocators} + +@item +@code{No_Relative_Delay} + +@item +@code{No_Requeue_Statements} + +@item +@code{No_Select_Statements} + +@item +@code{No_Specific_Termination_Handlers} + +@item +@code{No_Task_Allocators} + +@item +@code{No_Task_Hierarchy} + +@item +@code{No_Task_Termination} + +@item +@code{Simple_Barriers} +@end itemize The Ravenscar profile also includes the following restrictions that specify that there are no semantic dependences on the corresponding predefined packages: -@table @code -@item No_Dependence => Ada.Asynchronous_Task_Control -@item No_Dependence => Ada.Calendar -@item No_Dependence => Ada.Execution_Time.Group_Budget -@item No_Dependence => Ada.Execution_Time.Timers -@item No_Dependence => Ada.Task_Attributes -@item No_Dependence => System.Multiprocessors.Dispatching_Domains -@end table -@noindent +@itemize * + +@item +@code{No_Dependence => Ada.Asynchronous_Task_Control} + +@item +@code{No_Dependence => Ada.Calendar} + +@item +@code{No_Dependence => Ada.Execution_Time.Group_Budget} + +@item +@code{No_Dependence => Ada.Execution_Time.Timers} + +@item +@code{No_Dependence => Ada.Task_Attributes} + +@item +@code{No_Dependence => System.Multiprocessors.Dispatching_Domains} +@end itemize This set of configuration pragmas and restrictions correspond to the -definition of the ``Ravenscar Profile'' for limited tasking, devised and -published by the @cite{International Real-Time Ada Workshop}, 1997, -and whose most recent description is available at -@url{http://www-users.cs.york.ac.uk/~burns/ravenscar.ps}. +definition of the 'Ravenscar Profile' for limited tasking, devised and +published by the @cite{International Real-Time Ada Workshop@comma{} 1997}. +A description is also available at +@indicateurl{http://www-users.cs.york.ac.uk/~burns/ravenscar.ps}. The original definition of the profile was revised at subsequent IRTAW meetings. It has been included in the ISO -@cite{Guide for the Use of the Ada Programming Language in High -Integrity Systems}, and has been approved by ISO/IEC/SC22/WG9 for inclusion in -the next revision of the standard. The formal definition given by +@cite{Guide for the Use of the Ada Programming Language in High Integrity Systems}, +and was made part of the Ada 2005 standard. +The formal definition given by the Ada Rapporteur Group (ARG) can be found in two Ada Issues (AI-249 and AI-305) available at -@url{http://www.ada-auth.org/cgi-bin/cvsweb.cgi/ais/ai-00249.txt} and -@url{http://www.ada-auth.org/cgi-bin/cvsweb.cgi/ais/ai-00305.txt}. +@indicateurl{http://www.ada-auth.org/cgi-bin/cvsweb.cgi/ais/ai-00249.txt} and +@indicateurl{http://www.ada-auth.org/cgi-bin/cvsweb.cgi/ais/ai-00305.txt}. The above set is a superset of the restrictions provided by pragma @code{Profile (Restricted)}, it includes six additional restrictions @@ -5937,100 +6120,138 @@ The above set is a superset of the restrictions provided by pragma that pragma @code{Profile (Ravenscar)}, like the pragma @code{Profile (Restricted)}, automatically causes the use of a simplified, -more efficient version of the tasking run-time system. +more efficient version of the tasking run-time library. + +@item +Pragma Profile (Restricted) -@item Pragma Profile (Restricted) -@findex Restricted Run Time -@noindent This profile corresponds to the GNAT restricted run time. It establishes the following set of restrictions: -@itemize @bullet -@item No_Abort_Statements -@item No_Entry_Queue -@item No_Task_Hierarchy -@item No_Task_Allocators -@item No_Dynamic_Priorities -@item No_Terminate_Alternatives -@item No_Dynamic_Attachment -@item No_Protected_Type_Allocators -@item No_Local_Protected_Objects -@item No_Requeue_Statements -@item No_Task_Attributes_Package -@item Max_Asynchronous_Select_Nesting = 0 -@item Max_Task_Entries = 0 -@item Max_Protected_Entries = 1 -@item Max_Select_Alternatives = 0 -@end itemize - -@noindent + +@itemize * + +@item +@code{No_Abort_Statements} + +@item +@code{No_Entry_Queue} + +@item +@code{No_Task_Hierarchy} + +@item +@code{No_Task_Allocators} + +@item +@code{No_Dynamic_Priorities} + +@item +@code{No_Terminate_Alternatives} + +@item +@code{No_Dynamic_Attachment} + +@item +@code{No_Protected_Type_Allocators} + +@item +@code{No_Local_Protected_Objects} + +@item +@code{No_Requeue_Statements} + +@item +@code{No_Task_Attributes_Package} + +@item +@code{Max_Asynchronous_Select_Nesting = 0} + +@item +@code{Max_Task_Entries = 0} + +@item +@code{Max_Protected_Entries = 1} + +@item +@code{Max_Select_Alternatives = 0} +@end itemize + This set of restrictions causes the automatic selection of a simplified version of the run time that provides improved performance for the limited set of tasking functionality permitted by this set of restrictions. -@item Pragma Profile (Rational) -@findex Rational compatibility mode -@noindent +@item +Pragma Profile (Rational) + The Rational profile is intended to facilitate porting legacy code that compiles with the Rational APEX compiler, even when the code includes non- conforming Ada constructs. The profile enables the following three pragmas: -@itemize @bullet -@item pragma Implicit_Packing -@item pragma Overriding_Renamings -@item pragma Use_VADS_Size -@end itemize +@itemize * + +@item +@code{pragma Implicit_Packing} + +@item +@code{pragma Overriding_Renamings} + +@item +@code{pragma Use_VADS_Size} +@end itemize @end itemize -@node Pragma Profile_Warnings -@unnumberedsec Pragma Profile_Warnings -@findex Profile_Warnings -@noindent +@node Pragma Profile_Warnings,Pragma Propagate_Exceptions,Pragma Profile,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-profile-warnings}@anchor{a1} +@section Pragma Profile_Warnings + + Syntax: -@smallexample @c ada +@example pragma Profile_Warnings (Ravenscar | Restricted | Rational); -@end smallexample +@end example -@noindent This is an implementation-defined pragma that is similar in -effect to @code{pragma Profile} except that instead of -generating @code{Restrictions} pragmas, it generates -@code{Restriction_Warnings} pragmas. The result is that +effect to @cite{pragma Profile} except that instead of +generating @cite{Restrictions} pragmas, it generates +@cite{Restriction_Warnings} pragmas. The result is that violations of the profile generate warning messages instead of error messages. -@node Pragma Propagate_Exceptions -@unnumberedsec Pragma Propagate_Exceptions -@cindex Interfacing to C++ -@findex Propagate_Exceptions -@noindent +@node Pragma Propagate_Exceptions,Pragma Provide_Shift_Operators,Pragma Profile_Warnings,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-propagate-exceptions}@anchor{a2} +@section Pragma Propagate_Exceptions + + +@geindex Interfacing to C++ + Syntax: -@smallexample @c ada +@example pragma Propagate_Exceptions; -@end smallexample +@end example -@noindent This pragma is now obsolete and, other than generating a warning if warnings on obsolescent features are enabled, is ignored. It is retained for compatibility purposes. It used to be used in connection with optimization of a now-obsolete mechanism for implementation of exceptions. -@node Pragma Provide_Shift_Operators -@unnumberedsec Pragma Provide_Shift_Operators -@cindex Shift operators -@findex Provide_Shift_Operators -@noindent +@node Pragma Provide_Shift_Operators,Pragma Psect_Object,Pragma Propagate_Exceptions,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-provide-shift-operators}@anchor{a3} +@section Pragma Provide_Shift_Operators + + +@geindex Shift operators + Syntax: -@smallexample @c ada +@example pragma Provide_Shift_Operators (integer_first_subtype_LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma can be applied to a first subtype local name that specifies either an unsigned or signed type. It has the effect of providing the five shift operators (Shift_Left, Shift_Right, Shift_Right_Arithmetic, @@ -6038,13 +6259,14 @@ Rotate_Left and Rotate_Right) for the given type. It is similar to including the function declarations for these five operators, together with the pragma Import (Intrinsic, ...) statements. -@node Pragma Psect_Object -@unnumberedsec Pragma Psect_Object -@findex Psect_Object -@noindent +@node Pragma Psect_Object,Pragma Pure_Function,Pragma Provide_Shift_Operators,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-psect-object}@anchor{a4} +@section Pragma Psect_Object + + Syntax: -@smallexample @c ada +@example pragma Psect_Object ( [Internal =>] LOCAL_NAME, [, [External =>] EXTERNAL_SYMBOL] @@ -6053,26 +6275,25 @@ pragma Psect_Object ( EXTERNAL_SYMBOL ::= IDENTIFIER | static_string_EXPRESSION -@end smallexample +@end example + +This pragma is identical in effect to pragma @cite{Common_Object}. + +@node Pragma Pure_Function,Pragma Rational,Pragma Psect_Object,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-pure-function}@anchor{a5} +@section Pragma Pure_Function -@noindent -This pragma is identical in effect to pragma @code{Common_Object}. -@node Pragma Pure_Function -@unnumberedsec Pragma Pure_Function -@findex Pure_Function -@noindent Syntax: -@smallexample @c ada +@example pragma Pure_Function ([Entity =>] function_LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma appears in the same declarative part as a function declaration (or a set of function declarations if more than one overloaded declaration exists, in which case the pragma applies -to all entities). It specifies that the function @code{Entity} is +to all entities). It specifies that the function @cite{Entity} is to be considered pure for the purposes of code generation. This means that the compiler can assume that there are no side effects, and in particular that two calls with identical arguments produce the @@ -6080,7 +6301,7 @@ same result. It also means that the function can be used in an address clause. Note that, quite deliberately, there are no static checks to try -to ensure that this promise is met, so @code{Pure_Function} can be used +to ensure that this promise is met, so @cite{Pure_Function} can be used with functions that are conceptually pure, even if they do modify global variables. For example, a square root function that is instrumented to count the number of times it is called is still @@ -6097,129 +6318,131 @@ the compiler may optimize away calls with identical arguments, and if that results in unexpected behavior, the proper action is not to use the pragma for subprograms that are not (conceptually) pure. -@findex Pure -Note: Most functions in a @code{Pure} package are automatically pure, and -there is no need to use pragma @code{Pure_Function} for such functions. One +Note: Most functions in a @cite{Pure} package are automatically pure, and +there is no need to use pragma @cite{Pure_Function} for such functions. One exception is any function that has at least one formal of type -@code{System.Address} or a type derived from it. Such functions are not +@cite{System.Address} or a type derived from it. Such functions are not considered pure by default, since the compiler assumes that the -@code{Address} parameter may be functioning as a pointer and that the +@cite{Address} parameter may be functioning as a pointer and that the referenced data may change even if the address value does not. Similarly, imported functions are not considered to be pure by default, since there is no way of checking that they are in fact pure. The use -of pragma @code{Pure_Function} for such a function will override these default +of pragma @cite{Pure_Function} for such a function will override these default assumption, and cause the compiler to treat a designated subprogram as pure in these cases. -Note: If pragma @code{Pure_Function} is applied to a renamed function, it +Note: If pragma @cite{Pure_Function} is applied to a renamed function, it applies to the underlying renamed function. This can be used to disambiguate cases of overloading where some but not all functions in a set of overloaded functions are to be designated as pure. -If pragma @code{Pure_Function} is applied to a library level function, the +If pragma @cite{Pure_Function} is applied to a library level function, the function is also considered pure from an optimization point of view, but the unit is not a Pure unit in the categorization sense. So for example, a function -thus marked is free to @code{with} non-pure units. +thus marked is free to @cite{with} non-pure units. + +@node Pragma Rational,Pragma Ravenscar,Pragma Pure_Function,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-rational}@anchor{a6} +@section Pragma Rational + -@node Pragma Rational -@unnumberedsec Pragma Rational -@findex Rational -@noindent Syntax: -@smallexample @c ada +@example pragma Rational; -@end smallexample +@end example -@noindent This pragma is considered obsolescent, but is retained for compatibility purposes. It is equivalent to: -@smallexample @c ada +@example pragma Profile (Rational); -@end smallexample +@end example + +@node Pragma Ravenscar,Pragma Refined_Depends,Pragma Rational,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-ravenscar}@anchor{a7} +@section Pragma Ravenscar + -@node Pragma Ravenscar -@unnumberedsec Pragma Ravenscar -@findex Pragma Ravenscar -@noindent Syntax: -@smallexample @c ada +@example pragma Ravenscar; -@end smallexample +@end example -@noindent This pragma is considered obsolescent, but is retained for compatibility purposes. It is equivalent to: -@smallexample @c ada +@example pragma Profile (Ravenscar); -@end smallexample +@end example + +which is the preferred method of setting the @cite{Ravenscar} profile. + +@node Pragma Refined_Depends,Pragma Refined_Global,Pragma Ravenscar,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-refined-depends}@anchor{a8} +@section Pragma Refined_Depends -@noindent -which is the preferred method of setting the @code{Ravenscar} profile. -@node Pragma Refined_Depends -@unnumberedsec Pragma Refined_Depends -@findex Refined_Depends -@noindent For the description of this pragma, see SPARK 2014 Reference Manual, section 6.1.5. -@node Pragma Refined_Global -@unnumberedsec Pragma Refined_Global -@findex Refined_Global -@noindent +@node Pragma Refined_Global,Pragma Refined_Post,Pragma Refined_Depends,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-refined-global}@anchor{a9} +@section Pragma Refined_Global + + For the description of this pragma, see SPARK 2014 Reference Manual, section 6.1.4. -@node Pragma Refined_Post -@unnumberedsec Pragma Refined_Post -@findex Refined_Post -@noindent +@node Pragma Refined_Post,Pragma Refined_State,Pragma Refined_Global,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-refined-post}@anchor{aa} +@section Pragma Refined_Post + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.2.7. -@node Pragma Refined_State -@unnumberedsec Pragma Refined_State -@findex Refined_State -@noindent +@node Pragma Refined_State,Pragma Relative_Deadline,Pragma Refined_Post,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-refined-state}@anchor{ab} +@section Pragma Refined_State + + For the description of this pragma, see SPARK 2014 Reference Manual, section 7.2.2. -@node Pragma Relative_Deadline -@unnumberedsec Pragma Relative_Deadline -@findex Relative_Deadline -@noindent +@node Pragma Relative_Deadline,Pragma Remote_Access_Type,Pragma Refined_State,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-relative-deadline}@anchor{ac} +@section Pragma Relative_Deadline + + Syntax: -@smallexample @c ada +@example pragma Relative_Deadline (time_span_EXPRESSION); -@end smallexample +@end example -@noindent This pragma is standard in Ada 2005, but is available in all earlier versions of Ada as an implementation-defined pragma. See Ada 2012 Reference Manual for details. -@node Pragma Remote_Access_Type -@unnumberedsec Pragma Remote_Access_Type -@findex Remote_Access_Type -@noindent +@node Pragma Remote_Access_Type,Pragma Restricted_Run_Time,Pragma Relative_Deadline,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-remote-access-type}@anchor{ad} +@section Pragma Remote_Access_Type + + Syntax: -@smallexample @c ada +@example pragma Remote_Access_Type ([Entity =>] formal_access_type_LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma appears in the formal part of a generic declaration. It specifies an exception to the RM rule from E.2.2(17/2), which forbids the use of a remote access to class-wide type as actual for a formal access type. -When this pragma applies to a formal access type @code{Entity}, that +When this pragma applies to a formal access type @cite{Entity}, that type is treated as a remote access to class-wide type in the generic. It must be a formal general access type, and its designated type must be the class-wide type of a formal tagged limited private type from the @@ -6229,43 +6452,42 @@ In the generic unit, the formal type is subject to all restrictions pertaining to remote access to class-wide types. At instantiation, the actual type must be a remote access to class-wide type. -@node Pragma Restricted_Run_Time -@unnumberedsec Pragma Restricted_Run_Time -@findex Pragma Restricted_Run_Time -@noindent +@node Pragma Restricted_Run_Time,Pragma Restriction_Warnings,Pragma Remote_Access_Type,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-restricted-run-time}@anchor{ae} +@section Pragma Restricted_Run_Time + + Syntax: -@smallexample @c ada +@example pragma Restricted_Run_Time; -@end smallexample +@end example -@noindent This pragma is considered obsolescent, but is retained for compatibility purposes. It is equivalent to: -@smallexample @c ada +@example pragma Profile (Restricted); -@end smallexample +@end example -@noindent which is the preferred method of setting the restricted run time profile. -@node Pragma Restriction_Warnings -@unnumberedsec Pragma Restriction_Warnings -@findex Restriction_Warnings -@noindent +@node Pragma Restriction_Warnings,Pragma Reviewable,Pragma Restricted_Run_Time,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-restriction-warnings}@anchor{af} +@section Pragma Restriction_Warnings + + Syntax: -@smallexample @c ada +@example pragma Restriction_Warnings (restriction_IDENTIFIER @{, restriction_IDENTIFIER@}); -@end smallexample +@end example -@noindent This pragma allows a series of restriction identifiers to be specified (the list of allowed identifiers is the same as for -pragma @code{Restrictions}). For each of these identifiers +pragma @cite{Restrictions}). For each of these identifiers the compiler checks for violations of the restriction, but generates a warning message rather than an error message if the restriction is violated. @@ -6276,165 +6498,160 @@ these violations. Consider this example, where you want to set Ada_95 mode and enable style checks, but you want to know about any other use of implementation pragmas: -@smallexample @c ada +@example pragma Restriction_Warnings (No_Implementation_Pragmas); -7 (Off, "violation of*No_Implementation_Pragmas*"); +pragma Warnings (Off, "violation of No_Implementation_Pragmas"); pragma Ada_95; pragma Style_Checks ("2bfhkM160"); -pragma Warnings (On, "violation of*No_Implementation_Pragmas*"); -@end smallexample +pragma Warnings (On, "violation of No_Implementation_Pragmas"); +@end example -@noindent By including the above lines in a configuration pragmas file, the Ada_95 and Style_Checks pragmas are accepted without generating a warning, but any other use of implementation defined pragmas will cause a warning to be generated. -@node Pragma Reviewable -@unnumberedsec Pragma Reviewable -@findex Reviewable -@noindent +@node Pragma Reviewable,Pragma Share_Generic,Pragma Restriction_Warnings,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-reviewable}@anchor{b0} +@section Pragma Reviewable + + Syntax: -@smallexample @c ada +@example pragma Reviewable; -@end smallexample +@end example -@noindent This pragma is an RM-defined standard pragma, but has no effect on the program being compiled, or on the code generated for the program. To obtain the required output specified in RM H.3.1, the compiler must be run with various special switches as follows: -@table @i -@item Where compiler-generated run-time checks remain +@itemize * + +@item +@emph{Where compiler-generated run-time checks remain} -The switch @option{-gnatGL} -@findex @option{-gnatGL} +The switch @emph{-gnatGL} may be used to list the expanded code in pseudo-Ada form. Runtime checks show up in the listing either as explicit checks or operators marked with @{@} to indicate a check is present. -@item An identification of known exceptions at compile time +@item +@emph{An identification of known exceptions at compile time} -If the program is compiled with @option{-gnatwa}, -@findex @option{-gnatwa} +If the program is compiled with @emph{-gnatwa}, the compiler warning messages will indicate all cases where the compiler detects that an exception is certain to occur at run time. -@item Possible reads of uninitialized variables +@item +@emph{Possible reads of uninitialized variables} The compiler warns of many such cases, but its output is incomplete. -@ifclear FSFEDITION -The CodePeer analysis tool -@findex CodePeer static analysis tool -@end ifclear -@ifset FSFEDITION +@end itemize + + A supplemental static analysis tool -@end ifset may be used to obtain a comprehensive list of all possible points at which uninitialized data may be read. -@item Where run-time support routines are implicitly invoked -In the output from @option{-gnatGL}, -@findex @option{-gnatGL} +@itemize * + +@item +@emph{Where run-time support routines are implicitly invoked} + +In the output from @emph{-gnatGL}, run-time calls are explicitly listed as calls to the relevant run-time routine. -@item Object code listing +@item +@emph{Object code listing} -This may be obtained either by using the @option{-S} switch, -@findex @option{-S} +This may be obtained either by using the @emph{-S} switch, or the objdump utility. -@findex objdump -@item Constructs known to be erroneous at compile time +@item +@emph{Constructs known to be erroneous at compile time} -These are identified by warnings issued by the compiler (use @option{-gnatwa}). -@findex @option{-gnatwa} +These are identified by warnings issued by the compiler (use @emph{-gnatwa}). -@item Stack usage information +@item +@emph{Stack usage information} Static stack usage data (maximum per-subprogram) can be obtained via the -@option{-fstack-usage} switch to the compiler. -@findex @option{-fstack-usage} -Dynamic stack usage data (per task) can be obtained via the @option{-u} switch +@emph{-fstack-usage} switch to the compiler. +Dynamic stack usage data (per task) can be obtained via the @emph{-u} switch to gnatbind -@findex @option{-u} -@ifclear FSFEDITION -The gnatstack utility -@findex gnatstack -can be used to provide additional information on stack usage. -@end ifclear +@end itemize -@item Object code listing of entire partition -This can be obtained by compiling the partition with @option{-S}, -@findex @option{-S} + +@itemize * + +@item +@emph{Object code listing of entire partition} + +This can be obtained by compiling the partition with @emph{-S}, or by applying objdump -@findex objdump to all the object files that are part of the partition. -@item A description of the run-time model +@item +@emph{A description of the run-time model} The full sources of the run-time are available, and the documentation of these routines describes how these run-time routines interface to the underlying operating system facilities. -@item Control and data-flow information +@item +@emph{Control and data-flow information} +@end itemize + -@ifclear FSFEDITION -The CodePeer tool -@findex CodePeer static analysis tool -@end ifclear -@ifset FSFEDITION A supplemental static analysis tool -@end ifset may be used to obtain complete control and data-flow information, as well as comprehensive messages identifying possible problems based on this information. -@end table -@node Pragma Share_Generic -@unnumberedsec Pragma Share_Generic -@findex Share_Generic -@noindent +@node Pragma Share_Generic,Pragma Shared,Pragma Reviewable,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-share-generic}@anchor{b1} +@section Pragma Share_Generic + + Syntax: -@smallexample @c ada +@example pragma Share_Generic (GNAME @{, GNAME@}); GNAME ::= generic_unit_NAME | generic_instance_NAME -@end smallexample +@end example -@noindent This pragma is provided for compatibility with Dec Ada 83. It has -no effect in @code{GNAT} (which does not implement shared generics), other +no effect in @cite{GNAT} (which does not implement shared generics), other than to check that the given names are all names of generic units or generic instances. -@node Pragma Shared -@unnumberedsec Pragma Shared -@findex Shared +@node Pragma Shared,Pragma Short_Circuit_And_Or,Pragma Share_Generic,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-shared}@anchor{b2} +@section Pragma Shared + -@noindent This pragma is provided for compatibility with Ada 83. The syntax and semantics are identical to pragma Atomic. -@node Pragma Short_Circuit_And_Or -@unnumberedsec Pragma Short_Circuit_And_Or -@findex Short_Circuit_And_Or -@noindent +@node Pragma Short_Circuit_And_Or,Pragma Short_Descriptors,Pragma Shared,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-short-circuit-and-or}@anchor{b3} +@section Pragma Short_Circuit_And_Or + + Syntax: -@smallexample @c ada +@example pragma Short_Circuit_And_Or; -@end smallexample +@end example -@noindent This configuration pragma causes any occurrence of the AND operator applied to operands of type Standard.Boolean to be short-circuited (i.e. the AND operator is treated as if it were AND THEN). Or is similarly treated as OR ELSE. This @@ -6443,45 +6660,48 @@ short-circuited logical operators. If this configuration pragma occurs locally within the file being compiled, it applies only to the file being compiled. There is no requirement that all units in a partition use this option. -@node Pragma Short_Descriptors -@unnumberedsec Pragma Short_Descriptors -@findex Short_Descriptors -@noindent +@node Pragma Short_Descriptors,Pragma Simple_Storage_Pool_Type,Pragma Short_Circuit_And_Or,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-short-descriptors}@anchor{b4} +@section Pragma Short_Descriptors + + Syntax: -@smallexample @c ada +@example pragma Short_Descriptors -@end smallexample +@end example -@noindent This pragma is provided for compatibility with other Ada implementations. It is recognized but ignored by all current versions of GNAT. -@node Pragma Simple_Storage_Pool_Type -@unnumberedsec Pragma Simple_Storage_Pool_Type -@findex Simple_Storage_Pool_Type -@cindex Storage pool, simple -@cindex Simple storage pool -@noindent +@node Pragma Simple_Storage_Pool_Type,Pragma Source_File_Name,Pragma Short_Descriptors,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-simple-storage-pool-type}@anchor{b5} +@section Pragma Simple_Storage_Pool_Type + + +@geindex Storage pool +@geindex simple + +@geindex Simple storage pool + Syntax: -@smallexample @c ada +@example pragma Simple_Storage_Pool_Type (type_LOCAL_NAME); -@end smallexample +@end example -@noindent -A type can be established as a ``simple storage pool type'' by applying -the representation pragma @code{Simple_Storage_Pool_Type} to the type. +A type can be established as a 'simple storage pool type' by applying +the representation pragma @cite{Simple_Storage_Pool_Type} to the type. A type named in the pragma must be a library-level immutably limited record type or limited tagged type declared immediately within a package declaration. The type can also be a limited private type whose full type is allowed as a simple storage pool type. -For a simple storage pool type @var{SSP}, nonabstract primitive subprograms -@code{Allocate}, @code{Deallocate}, and @code{Storage_Size} can be declared that +For a simple storage pool type @cite{SSP}, nonabstract primitive subprograms +@cite{Allocate}, @cite{Deallocate}, and @cite{Storage_Size} can be declared that are subtype conformant with the following subprogram declarations: -@smallexample @c ada +@example procedure Allocate (Pool : in out SSP; Storage_Address : out System.Address; @@ -6496,41 +6716,40 @@ procedure Deallocate function Storage_Size (Pool : SSP) return System.Storage_Elements.Storage_Count; -@end smallexample +@end example -@noindent -Procedure @code{Allocate} must be declared, whereas @code{Deallocate} and -@code{Storage_Size} are optional. If @code{Deallocate} is not declared, then +Procedure @cite{Allocate} must be declared, whereas @cite{Deallocate} and +@cite{Storage_Size} are optional. If @cite{Deallocate} is not declared, then applying an unchecked deallocation has no effect other than to set its actual -parameter to null. If @code{Storage_Size} is not declared, then the -@code{Storage_Size} attribute applied to an access type associated with +parameter to null. If @cite{Storage_Size} is not declared, then the +@cite{Storage_Size} attribute applied to an access type associated with a pool object of type SSP returns zero. Additional operations can be declared for a simple storage pool type (such as for supporting a mark/release storage-management discipline). An object of a simple storage pool type can be associated with an access -type by specifying the attribute @code{Simple_Storage_Pool}. For example: - -@smallexample @c ada +type by specifying the attribute +@ref{b6,,Simple_Storage_Pool}. For example: +@example My_Pool : My_Simple_Storage_Pool_Type; type Acc is access My_Data_Type; for Acc'Simple_Storage_Pool use My_Pool; +@end example + +See attribute @ref{b6,,Simple_Storage_Pool} +for further details. -@end smallexample +@node Pragma Source_File_Name,Pragma Source_File_Name_Project,Pragma Simple_Storage_Pool_Type,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-source-file-name}@anchor{b7}@anchor{gnat_rm/implementation_defined_pragmas id3}@anchor{b8} +@section Pragma Source_File_Name -@noindent -See attribute @code{Simple_Storage_Pool} for further details. -@node Pragma Source_File_Name -@unnumberedsec Pragma Source_File_Name -@findex Source_File_Name -@noindent Syntax: -@smallexample @c ada +@example pragma Source_File_Name ( [Unit_Name =>] unit_NAME, Spec_File_Name => STRING_LITERAL, @@ -6540,24 +6759,23 @@ pragma Source_File_Name ( [Unit_Name =>] unit_NAME, Body_File_Name => STRING_LITERAL, [Index => INTEGER_LITERAL]); -@end smallexample +@end example -@noindent Use this to override the normal naming convention. It is a configuration pragma, and so has the usual applicability of configuration pragmas -(i.e.@: it applies to either an entire partition, or to all units in a +(i.e., it applies to either an entire partition, or to all units in a compilation, or to a single unit, depending on how it is used. -@var{unit_name} is mapped to @var{file_name_literal}. The identifier for +@cite{unit_name} is mapped to @cite{file_name_literal}. The identifier for the second argument is required, and indicates whether this is the file name for the spec or for the body. The optional Index argument should be used when a file contains multiple -units, and when you do not want to use @code{gnatchop} to separate then +units, and when you do not want to use @cite{gnatchop} to separate then into multiple files (which is the recommended procedure to limit the number of recompilations that are needed when some sources change). -For instance, if the source file @file{source.ada} contains +For instance, if the source file @code{source.ada} contains -@smallexample @c ada +@example package B is ... end B; @@ -6567,25 +6785,25 @@ procedure A is begin .. end A; -@end smallexample +@end example you could use the following configuration pragmas: -@smallexample @c ada +@example pragma Source_File_Name (B, Spec_File_Name => "source.ada", Index => 1); pragma Source_File_Name (A, Body_File_Name => "source.ada", Index => 2); -@end smallexample +@end example -Note that the @code{gnatname} utility can also be used to generate those +Note that the @cite{gnatname} utility can also be used to generate those configuration pragmas. -Another form of the @code{Source_File_Name} pragma allows +Another form of the @cite{Source_File_Name} pragma allows the specification of patterns defining alternative file naming schemes to apply to all files. -@smallexample @c ada +@example pragma Source_File_Name ( [Spec_File_Name =>] STRING_LITERAL [,[Casing =>] CASING_SPEC] @@ -6602,9 +6820,8 @@ pragma Source_File_Name [,[Dot_Replacement =>] STRING_LITERAL]); CASING_SPEC ::= Lowercase | Uppercase | Mixedcase -@end smallexample +@end example -@noindent The first argument is a pattern that contains a single asterisk indicating the point at which the unit name is to be inserted in the pattern string to form the file name. The second argument is optional. If present it @@ -6618,21 +6835,19 @@ aware of these pragmas, and so other tools that use the projet file would not be aware of the intended naming conventions. If you are using project files, file naming is controlled by Source_File_Name_Project pragmas, which are usually supplied automatically by the project manager. A pragma -Source_File_Name cannot appear after a @ref{Pragma Source_File_Name_Project}. +Source_File_Name cannot appear after a @ref{b9,,Pragma Source_File_Name_Project}. + +For more details on the use of the @cite{Source_File_Name} pragma, see the +sections on @cite{Using Other File Names} and @cite{Alternative File Naming Schemes' in the :title:`GNAT User's Guide}. -For more details on the use of the @code{Source_File_Name} pragma, -@xref{Using Other File Names,,, gnat_ugn, @value{EDITION} User's Guide}, -and @ref{Alternative File Naming Schemes,,, gnat_ugn, @value{EDITION} -User's Guide}. +@node Pragma Source_File_Name_Project,Pragma Source_Reference,Pragma Source_File_Name,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas id4}@anchor{ba}@anchor{gnat_rm/implementation_defined_pragmas pragma-source-file-name-project}@anchor{b9} +@section Pragma Source_File_Name_Project -@node Pragma Source_File_Name_Project -@unnumberedsec Pragma Source_File_Name_Project -@findex Source_File_Name_Project -@noindent This pragma has the same syntax and semantics as pragma Source_File_Name. It is only allowed as a stand alone configuration pragma. -It cannot appear after a @ref{Pragma Source_File_Name}, and +It cannot appear after a @ref{b7,,Pragma Source_File_Name}, and most importantly, once pragma Source_File_Name_Project appears, no further Source_File_Name pragmas are allowed. @@ -6643,41 +6858,41 @@ it is not permissible to attempt to modify this naming scheme using Source_File_Name or Source_File_Name_Project pragmas (which would not be known to the project manager). -@node Pragma Source_Reference -@unnumberedsec Pragma Source_Reference -@findex Source_Reference -@noindent +@node Pragma Source_Reference,Pragma SPARK_Mode,Pragma Source_File_Name_Project,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-source-reference}@anchor{bb} +@section Pragma Source_Reference + + Syntax: -@smallexample @c ada +@example pragma Source_Reference (INTEGER_LITERAL, STRING_LITERAL); -@end smallexample +@end example -@noindent This pragma must appear as the first line of a source file. -@var{integer_literal} is the logical line number of the line following +@cite{integer_literal} is the logical line number of the line following the pragma line (for use in error messages and debugging -information). @var{string_literal} is a static string constant that +information). @cite{string_literal} is a static string constant that specifies the file name to be used in error messages and debugging -information. This is most notably used for the output of @code{gnatchop} -with the @option{-r} switch, to make sure that the original unchopped +information. This is most notably used for the output of @cite{gnatchop} +with the @emph{-r} switch, to make sure that the original unchopped source file is the one referred to. The second argument must be a string literal, it cannot be a static string expression other than a string literal. This is because its value is needed for error messages issued by all phases of the compiler. -@node Pragma SPARK_Mode -@unnumberedsec Pragma SPARK_Mode -@findex SPARK_Mode -@noindent +@node Pragma SPARK_Mode,Pragma Static_Elaboration_Desired,Pragma Source_Reference,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-spark-mode}@anchor{bc} +@section Pragma SPARK_Mode + + Syntax: -@smallexample @c ada +@example pragma SPARK_Mode [(On | Off)] ; -@end smallexample +@end example -@noindent In general a program can have some parts that are in SPARK 2014 (and follow all the rules in the SPARK Reference Manual), and some parts that are full Ada 2012. @@ -6686,79 +6901,80 @@ The SPARK_Mode pragma is used to identify which parts are in SPARK 2014 (by default programs are in full Ada). The SPARK_Mode pragma can be used in the following places: -@itemize @bullet -@item +@itemize * + +@item As a configuration pragma, in which case it sets the default mode for all units compiled with this pragma. -@item +@item Immediately following a library-level subprogram spec -@item +@item Immediately within a library-level package body -@item -Immediately following the @code{private} keyword of a library-level +@item +Immediately following the @cite{private} keyword of a library-level package spec -@item -Immediately following the @code{begin} keyword of a library-level +@item +Immediately following the @cite{begin} keyword of a library-level package body -@item +@item Immediately within a library-level subprogram body - @end itemize -@noindent Normally a subprogram or package spec/body inherits the current mode that is active at the point it is declared. But this can be overridden by pragma within the spec or body as above. The basic consistency rule is that you can't turn SPARK_Mode back -@code{On}, once you have explicitly (with a pragma) turned if -@code{Off}. So the following rules apply: +@cite{On}, once you have explicitly (with a pragma) turned if +@cite{Off}. So the following rules apply: -@noindent -If a subprogram spec has SPARK_Mode @code{Off}, then the body must -also have SPARK_Mode @code{Off}. +If a subprogram spec has SPARK_Mode @cite{Off}, then the body must +also have SPARK_Mode @cite{Off}. -@noindent For a package, we have four parts: -@itemize -@item + +@itemize * + +@item the package public declarations -@item + +@item the package private part -@item + +@item the body of the package -@item -the elaboration code after @code{begin} + +@item +the elaboration code after @cite{begin} @end itemize -@noindent For a package, the rule is that if you explicitly turn SPARK_Mode -@code{Off} for any part, then all the following parts must have -SPARK_Mode @code{Off}. Note that this may require repeating a pragma -SPARK_Mode (@code{Off}) in the body. For example, if we have a -configuration pragma SPARK_Mode (@code{On}) that turns the mode on by +@cite{Off} for any part, then all the following parts must have +SPARK_Mode @cite{Off}. Note that this may require repeating a pragma +SPARK_Mode (@cite{Off}) in the body. For example, if we have a +configuration pragma SPARK_Mode (@cite{On}) that turns the mode on by default everywhere, and one particular package spec has pragma -SPARK_Mode (@code{Off}), then that pragma will need to be repeated in +SPARK_Mode (@cite{Off}), then that pragma will need to be repeated in the package body. -@node Pragma Static_Elaboration_Desired -@unnumberedsec Pragma Static_Elaboration_Desired -@findex Static_Elaboration_Desired -@noindent +@node Pragma Static_Elaboration_Desired,Pragma Stream_Convert,Pragma SPARK_Mode,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-static-elaboration-desired}@anchor{bd} +@section Pragma Static_Elaboration_Desired + + Syntax: -@smallexample @c ada +@example pragma Static_Elaboration_Desired; -@end smallexample +@end example -@noindent This pragma is used to indicate that the compiler should attempt to initialize statically the objects declared in the library unit to which the pragma applies, when these objects are initialized (explicitly or implicitly) by an aggregate. @@ -6772,20 +6988,20 @@ be obeyed. (See also the restriction No_Implicit_Loops, which supports static construction of larger aggregates with static components that include an others choice.) -@node Pragma Stream_Convert -@unnumberedsec Pragma Stream_Convert -@findex Stream_Convert -@noindent +@node Pragma Stream_Convert,Pragma Style_Checks,Pragma Static_Elaboration_Desired,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-stream-convert}@anchor{be} +@section Pragma Stream_Convert + + Syntax: -@smallexample @c ada +@example pragma Stream_Convert ( [Entity =>] type_LOCAL_NAME, [Read =>] function_NAME, [Write =>] function_NAME); -@end smallexample +@end example -@noindent This pragma provides an efficient way of providing user-defined stream attributes. Not only is it simpler to use than specifying the attributes directly, but more importantly, it allows the specification to be made in such @@ -6800,13 +7016,13 @@ of this type. It must name a function whose argument type may be any subtype, and whose returned type must be the type given as the first argument to the pragma. -The meaning of the @var{Read} parameter is that if a stream attribute directly +The meaning of the @cite{Read} parameter is that if a stream attribute directly or indirectly specifies reading of the type given as the first parameter, then a value of the type given as the argument to the Read function is read from the stream, and then the Read function is used to convert this to the required target type. -Similarly the @var{Write} parameter specifies how to treat write attributes +Similarly the @cite{Write} parameter specifies how to treat write attributes that directly or indirectly apply to the type given as the first parameter. It must have an input parameter of the type specified by the first parameter, and the return type must be the same as the input type of the Read function. @@ -6818,249 +7034,238 @@ renamings can be supplied to meet this requirement. The usage of this attribute is best illustrated by a simple example, taken from the GNAT implementation of package Ada.Strings.Unbounded: -@smallexample @c ada -function To_Unbounded (S : String) - return Unbounded_String +@example +function To_Unbounded (S : String) return Unbounded_String renames To_Unbounded_String; pragma Stream_Convert (Unbounded_String, To_Unbounded, To_String); -@end smallexample +@end example -@noindent The specifications of the referenced functions, as given in the Ada Reference Manual are: -@smallexample @c ada +@example function To_Unbounded_String (Source : String) return Unbounded_String; function To_String (Source : Unbounded_String) return String; -@end smallexample +@end example -@noindent The effect is that if the value of an unbounded string is written to a stream, then the representation of the item in the stream is in the same format that -would be used for @code{Standard.String'Output}, and this same representation +would be used for @cite{Standard.String'Output}, and this same representation is expected when a value of this type is read from the stream. Note that the value written always includes the bounds, even for Unbounded_String'Write, since Unbounded_String is not an array type. -Note that the @code{Stream_Convert} pragma is not effective in the case of +Note that the @cite{Stream_Convert} pragma is not effective in the case of a derived type of a non-limited tagged type. If such a type is specified then the pragma is silently ignored, and the default implementation of the stream attributes is used instead. -@node Pragma Style_Checks -@unnumberedsec Pragma Style_Checks -@findex Style_Checks -@noindent +@node Pragma Style_Checks,Pragma Subtitle,Pragma Stream_Convert,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-style-checks}@anchor{bf} +@section Pragma Style_Checks + + Syntax: -@smallexample @c ada +@example pragma Style_Checks (string_LITERAL | ALL_CHECKS | On | Off [, LOCAL_NAME]); -@end smallexample +@end example -@noindent This pragma is used in conjunction with compiler switches to control the -built in style checking provided by GNAT@. The compiler switches, if set, +built in style checking provided by GNAT. The compiler switches, if set, provide an initial setting for the switches, and this pragma may be used to modify these settings, or the settings may be provided entirely by the use of the pragma. This pragma can be used anywhere that a pragma is legal, including use as a configuration pragma (including use in -the @file{gnat.adc} file). +the @code{gnat.adc} file). The form with a string literal specifies which style options are to be activated. These are additive, so they apply in addition to any previously set style check options. The codes for the options are the same as those -used in the @option{-gnaty} switch to @command{gcc} or @command{gnatmake}. +used in the @emph{-gnaty} switch to @emph{gcc} or @emph{gnatmake}. For example the following two methods can be used to enable layout checking: -@itemize @bullet -@item -@smallexample @c ada + +@itemize * + +@item +@example pragma Style_Checks ("l"); -@end smallexample +@end example -@item -@smallexample -gcc -c -gnatyl @dots{} -@end smallexample +@item +@example +gcc -c -gnatyl ... +@end example @end itemize -@noindent The form ALL_CHECKS activates all standard checks (its use is equivalent -to the use of the @code{gnaty} switch with no options. @xref{Top, -@value{EDITION} User's Guide, About This Guide, gnat_ugn, -@value{EDITION} User's Guide}, for details.) +to the use of the @cite{gnaty} switch with no options. +See the @cite{GNAT User's Guide} for details.) -Note: the behavior is slightly different in GNAT mode (@option{-gnatg} used). +Note: the behavior is slightly different in GNAT mode (@emph{-gnatg} used). In this case, ALL_CHECKS implies the standard set of GNAT mode style check -options (i.e. equivalent to -gnatyg). +options (i.e. equivalent to @emph{-gnatyg}). -The forms with @code{Off} and @code{On} +The forms with @cite{Off} and @cite{On} can be used to temporarily disable style checks as shown in the following example: -@smallexample @c ada -@iftex -@leftskip=0cm -@end iftex +@example pragma Style_Checks ("k"); -- requires keywords in lower case pragma Style_Checks (Off); -- turn off style checks NULL; -- this will not generate an error message pragma Style_Checks (On); -- turn style checks back on NULL; -- this will generate an error message -@end smallexample +@end example -@noindent Finally the two argument form is allowed only if the first argument is -@code{On} or @code{Off}. The effect is to turn of semantic style checks +@cite{On} or @cite{Off}. The effect is to turn of semantic style checks for the specified entity, as shown in the following example: -@smallexample @c ada -@iftex -@leftskip=0cm -@end iftex +@example pragma Style_Checks ("r"); -- require consistency of identifier casing Arg : Integer; Rf1 : Integer := ARG; -- incorrect, wrong case pragma Style_Checks (Off, Arg); Rf2 : Integer := ARG; -- OK, no error -@end smallexample +@end example + +@node Pragma Subtitle,Pragma Suppress,Pragma Style_Checks,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-subtitle}@anchor{c0} +@section Pragma Subtitle + -@node Pragma Subtitle -@unnumberedsec Pragma Subtitle -@findex Subtitle -@noindent Syntax: -@smallexample @c ada +@example pragma Subtitle ([Subtitle =>] STRING_LITERAL); -@end smallexample +@end example -@noindent This pragma is recognized for compatibility with other Ada compilers -but is ignored by GNAT@. +but is ignored by GNAT. + +@node Pragma Suppress,Pragma Suppress_All,Pragma Subtitle,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-suppress}@anchor{c1} +@section Pragma Suppress + -@node Pragma Suppress -@unnumberedsec Pragma Suppress -@findex Suppress -@noindent Syntax: -@smallexample @c ada +@example pragma Suppress (Identifier [, [On =>] Name]); -@end smallexample +@end example -@noindent This is a standard pragma, and supports all the check names required in the RM. It is included here because GNAT recognizes some additional check names that are implementation defined (as permitted by the RM): -@itemize @bullet -@item -@code{Alignment_Check} can be used to suppress alignment checks +@itemize * + +@item +@cite{Alignment_Check} can be used to suppress alignment checks on addresses used in address clauses. Such checks can also be suppressed -by suppressing range checks, but the specific use of @code{Alignment_Check} +by suppressing range checks, but the specific use of @cite{Alignment_Check} allows suppression of alignment checks without suppressing other range checks. -@item -@code{Atomic_Synchronization} can be used to suppress the special memory +@item +@cite{Atomic_Synchronization} can be used to suppress the special memory synchronization instructions that are normally generated for access to -@code{Atomic} variables to ensure correct synchronization between tasks +@cite{Atomic} variables to ensure correct synchronization between tasks that use such variables for synchronization purposes. -@item -@code{Duplicated_Tag_Check} Can be used to suppress the check that is generated +@item +@cite{Duplicated_Tag_Check} Can be used to suppress the check that is generated for a duplicated tag value when a tagged type is declared. -@item -@code{Predicate_Check} can be used to control whether predicate checks are +@item +@cite{Predicate_Check} can be used to control whether predicate checks are active. It is applicable only to predicates for which the policy is -@code{Check}. Unlike @code{Assertion_Policy}, which determines if a given +@cite{Check}. Unlike @cite{Assertion_Policy}, which determines if a given predicate is ignored or checked for the whole program, the use of -@code{Suppress} and @code{Unsuppress} with this check name allows a given +@cite{Suppress} and @cite{Unsuppress} with this check name allows a given predicate to be turned on and off at specific points in the program. -@item -@code{Validity_Check} can be used specifically to control validity checks. -If @code{Suppress} is used to suppress validity checks, then no validity +@item +@cite{Validity_Check} can be used specifically to control validity checks. +If @cite{Suppress} is used to suppress validity checks, then no validity checks are performed, including those specified by the appropriate compiler -switch or the @code{Validity_Checks} pragma. +switch or the @cite{Validity_Checks} pragma. -@item -Additional check names previously introduced by use of the @code{Check_Name} +@item +Additional check names previously introduced by use of the @cite{Check_Name} pragma are also allowed. - @end itemize -@noindent Note that pragma Suppress gives the compiler permission to omit checks, but does not require the compiler to omit checks. The compiler will generate checks if they are essentially free, even when they are suppressed. In particular, if the compiler can prove that a certain check will necessarily fail, it will generate code to do an -unconditional ``raise'', even if checks are suppressed. The compiler +unconditional 'raise', even if checks are suppressed. The compiler warns in this case. Of course, run-time checks are omitted whenever the compiler can prove that they will not fail, whether or not checks are suppressed. -@node Pragma Suppress_All -@unnumberedsec Pragma Suppress_All -@findex Suppress_All -@noindent +@node Pragma Suppress_All,Pragma Suppress_Debug_Info,Pragma Suppress,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-suppress-all}@anchor{c2} +@section Pragma Suppress_All + + Syntax: -@smallexample @c ada +@example pragma Suppress_All; -@end smallexample +@end example -@noindent This pragma can appear anywhere within a unit. -The effect is to apply @code{Suppress (All_Checks)} to the unit +The effect is to apply @cite{Suppress (All_Checks)} to the unit in which it appears. This pragma is implemented for compatibility with DEC Ada 83 usage where it appears at the end of a unit, and for compatibility with Rational Ada, where it appears as a program unit pragma. -The use of the standard Ada pragma @code{Suppress (All_Checks)} -as a normal configuration pragma is the preferred usage in GNAT@. +The use of the standard Ada pragma @cite{Suppress (All_Checks)} +as a normal configuration pragma is the preferred usage in GNAT. + +@node Pragma Suppress_Debug_Info,Pragma Suppress_Exception_Locations,Pragma Suppress_All,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-suppress-debug-info}@anchor{c3} +@section Pragma Suppress_Debug_Info + -@node Pragma Suppress_Debug_Info -@unnumberedsec Pragma Suppress_Debug_Info -@findex Suppress_Debug_Info -@noindent Syntax: -@smallexample @c ada -Suppress_Debug_Info ([Entity =>] LOCAL_NAME); -@end smallexample +@example +pragma Suppress_Debug_Info ([Entity =>] LOCAL_NAME); +@end example -@noindent This pragma can be used to suppress generation of debug information for the specified entity. It is intended primarily for use in debugging the debugger, and navigating around debugger problems. -@node Pragma Suppress_Exception_Locations -@unnumberedsec Pragma Suppress_Exception_Locations -@findex Suppress_Exception_Locations -@noindent +@node Pragma Suppress_Exception_Locations,Pragma Suppress_Initialization,Pragma Suppress_Debug_Info,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-suppress-exception-locations}@anchor{c4} +@section Pragma Suppress_Exception_Locations + + Syntax: -@smallexample @c ada +@example pragma Suppress_Exception_Locations; -@end smallexample +@end example -@noindent In normal mode, a raise statement for an exception by default generates an exception message giving the file name and line number for the location of the raise. This is useful for debugging and logging purposes, but this entails extra space for the strings for the messages. The configuration -pragma @code{Suppress_Exception_Locations} can be used to suppress the +pragma @cite{Suppress_Exception_Locations} can be used to suppress the generation of these strings, with the result that space is saved, but the exception message for such raises is null. This configuration pragma may appear in a global configuration pragma file, or in a specific unit as @@ -7068,19 +7273,22 @@ usual. It is not required that this pragma be used consistently within a partition, so it is fine to have some units within a partition compiled with this pragma and others compiled in normal mode without it. -@node Pragma Suppress_Initialization -@unnumberedsec Pragma Suppress_Initialization -@findex Suppress_Initialization -@cindex Suppressing initialization -@cindex Initialization, suppression of -@noindent +@node Pragma Suppress_Initialization,Pragma Task_Name,Pragma Suppress_Exception_Locations,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-suppress-initialization}@anchor{c5} +@section Pragma Suppress_Initialization + + +@geindex Suppressing initialization + +@geindex Initialization +@geindex suppression of + Syntax: -@smallexample @c ada +@example pragma Suppress_Initialization ([Entity =>] variable_or_subtype_Name); -@end smallexample +@end example -@noindent Here variable_or_subtype_Name is the name introduced by a type declaration or subtype declaration or the name of a variable introduced by an object declaration. @@ -7110,19 +7318,19 @@ For the variable case, implicit initialization for the named variable is suppressed, just as though its subtype had been given in a pragma Suppress_Initialization, as described above. -@node Pragma Task_Name -@unnumberedsec Pragma Task_Name -@findex Task_Name -@noindent +@node Pragma Task_Name,Pragma Task_Storage,Pragma Suppress_Initialization,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-task-name}@anchor{c6} +@section Pragma Task_Name + + Syntax -@smallexample @c ada +@example pragma Task_Name (string_EXPRESSION); -@end smallexample +@end example -@noindent This pragma appears within a task definition (like pragma -@code{Priority}) and applies to the task in which it appears. The +@cite{Priority}) and applies to the task in which it appears. The argument must be of type String, and provides a name to be used for the task instance when the task is created. Note that this expression is not required to be static, and in particular, it can contain @@ -7132,10 +7340,10 @@ as illustrated in the example below. The task name is recorded internally in the run-time structures and is accessible to tools like the debugger. In addition the -routine @code{Ada.Task_Identification.Image} will return this +routine @cite{Ada.Task_Identification.Image} will return this string, with a unique task address appended. -@smallexample @c ada +@example -- Example of the use of pragma Task_Name with Ada.Task_Identification; @@ -7164,63 +7372,65 @@ begin Task_Var := new Task_Typ (new String'("This is task 2")); end; -@end smallexample +@end example + +@node Pragma Task_Storage,Pragma Test_Case,Pragma Task_Name,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-task-storage}@anchor{c7} +@section Pragma Task_Storage + -@node Pragma Task_Storage -@unnumberedsec Pragma Task_Storage -@findex Task_Storage Syntax: -@smallexample @c ada +@example pragma Task_Storage ( [Task_Type =>] LOCAL_NAME, [Top_Guard =>] static_integer_EXPRESSION); -@end smallexample +@end example -@noindent This pragma specifies the length of the guard area for tasks. The guard area is an additional storage area allocated to a task. A value of zero means that either no guard area is created or a minimal guard area is created, depending on the target. This pragma can appear anywhere a -@code{Storage_Size} attribute definition clause is allowed for a task +@cite{Storage_Size} attribute definition clause is allowed for a task type. -@node Pragma Test_Case -@unnumberedsec Pragma Test_Case -@cindex Test cases -@findex Test_Case -@noindent +@node Pragma Test_Case,Pragma Thread_Local_Storage,Pragma Task_Storage,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-test-case}@anchor{c8} +@section Pragma Test_Case + + +@geindex Test cases + Syntax: -@smallexample @c ada +@example pragma Test_Case ( [Name =>] static_string_Expression ,[Mode =>] (Nominal | Robustness) [, Requires => Boolean_Expression] [, Ensures => Boolean_Expression]); -@end smallexample +@end example -@noindent -The @code{Test_Case} pragma allows defining fine-grain specifications +The @cite{Test_Case} pragma allows defining fine-grain specifications for use by testing tools. -The compiler checks the validity of the @code{Test_Case} pragma, but its +The compiler checks the validity of the @cite{Test_Case} pragma, but its presence does not lead to any modification of the code generated by the compiler. -@code{Test_Case} pragmas may only appear immediately following the +@cite{Test_Case} pragmas may only appear immediately following the (separate) declaration of a subprogram in a package declaration, inside a package spec unit. Only other pragmas may intervene (that is appear between the subprogram declaration and a test case). -The compiler checks that boolean expressions given in @code{Requires} and -@code{Ensures} are valid, where the rules for @code{Requires} are the -same as the rule for an expression in @code{Precondition} and the rules -for @code{Ensures} are the same as the rule for an expression in -@code{Postcondition}. In particular, attributes @code{'Old} and -@code{'Result} can only be used within the @code{Ensures} +The compiler checks that boolean expressions given in @cite{Requires} and +@cite{Ensures} are valid, where the rules for @cite{Requires} are the +same as the rule for an expression in @cite{Precondition} and the rules +for @cite{Ensures} are the same as the rule for an expression in +@cite{Postcondition}. In particular, attributes @cite{'Old} and +@cite{'Result} can only be used within the @cite{Ensures} expression. The following is an example of use within a package spec: -@smallexample @c ada +@example package Math_Functions is ... function Sqrt (Arg : Float) return Float; @@ -7230,153 +7440,152 @@ package Math_Functions is Ensures => Sqrt'Result < 10); ... end Math_Functions; -@end smallexample +@end example -@noindent The meaning of a test case is that there is at least one context where -@code{Requires} holds such that, if the associated subprogram is executed in -that context, then @code{Ensures} holds when the subprogram returns. -Mode @code{Nominal} indicates that the input context should also satisfy the +@cite{Requires} holds such that, if the associated subprogram is executed in +that context, then @cite{Ensures} holds when the subprogram returns. +Mode @cite{Nominal} indicates that the input context should also satisfy the precondition of the subprogram, and the output context should also satisfy its -postcondition. Mode @code{Robustness} indicates that the precondition and +postcondition. Mode @cite{Robustness} indicates that the precondition and postcondition of the subprogram should be ignored for this test case. -@node Pragma Thread_Local_Storage -@unnumberedsec Pragma Thread_Local_Storage -@findex Thread_Local_Storage -@cindex Task specific storage -@cindex TLS (Thread Local Storage) -@cindex Task_Attributes +@node Pragma Thread_Local_Storage,Pragma Time_Slice,Pragma Test_Case,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-thread-local-storage}@anchor{c9} +@section Pragma Thread_Local_Storage + + +@geindex Task specific storage + +@geindex TLS (Thread Local Storage) + +@geindex Task_Attributes + Syntax: -@smallexample @c ada +@example pragma Thread_Local_Storage ([Entity =>] LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma specifies that the specified entity, which must be a variable declared in a library level package, is to be marked as -"Thread Local Storage" (@code{TLS}). On systems supporting this (which +"Thread Local Storage" (@cite{TLS}). On systems supporting this (which include Solaris, GNU/Linux and VxWorks 6), this causes each thread (and hence each Ada task) to see a distinct copy of the variable. The variable may not have default initialization, and if there is -an explicit initialization, it must be either @code{null} for an +an explicit initialization, it must be either @cite{null} for an access variable, or a static expression for a scalar variable. This provides a low level mechanism similar to that provided by -the @code{Ada.Task_Attributes} package, but much more efficient +the @cite{Ada.Task_Attributes} package, but much more efficient and is also useful in writing interface code that will interact with foreign threads. -If this pragma is used on a system where @code{TLS} is not supported, +If this pragma is used on a system where @cite{TLS} is not supported, then an error message will be generated and the program will be rejected. -@node Pragma Time_Slice -@unnumberedsec Pragma Time_Slice -@findex Time_Slice -@noindent +@node Pragma Time_Slice,Pragma Title,Pragma Thread_Local_Storage,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-time-slice}@anchor{ca} +@section Pragma Time_Slice + + Syntax: -@smallexample @c ada +@example pragma Time_Slice (static_duration_EXPRESSION); -@end smallexample +@end example -@noindent For implementations of GNAT on operating systems where it is possible to supply a time slice value, this pragma may be used for this purpose. It is ignored if it is used in a system that does not allow this control, or if it appears in other than the main program unit. -@cindex OpenVMS -Note that the effect of this pragma is identical to the effect of the -DEC Ada 83 pragma of the same name when operating under OpenVMS systems. - -@node Pragma Title -@unnumberedsec Pragma Title -@findex Title -@noindent + +@node Pragma Title,Pragma Type_Invariant,Pragma Time_Slice,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-title}@anchor{cb} +@section Pragma Title + + Syntax: -@smallexample @c ada +@example pragma Title (TITLING_OPTION [, TITLING OPTION]); TITLING_OPTION ::= [Title =>] STRING_LITERAL, | [Subtitle =>] STRING_LITERAL -@end smallexample +@end example -@noindent -Syntax checked but otherwise ignored by GNAT@. This is a listing control +Syntax checked but otherwise ignored by GNAT. This is a listing control pragma used in DEC Ada 83 implementations to provide a title and/or subtitle for the program listing. The program listing generated by GNAT does not have titles or subtitles. Unlike other pragmas, the full flexibility of named notation is allowed -for this pragma, i.e.@: the parameters may be given in any order if named +for this pragma, i.e., the parameters may be given in any order if named notation is used, and named and positional notation can be mixed following the normal rules for procedure calls in Ada. -@node Pragma Type_Invariant -@unnumberedsec Pragma Type_Invariant -@findex Invariant -@findex Type_Invariant pragma -@noindent +@node Pragma Type_Invariant,Pragma Type_Invariant_Class,Pragma Title,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-type-invariant}@anchor{cc} +@section Pragma Type_Invariant + + Syntax: -@smallexample @c ada +@example pragma Type_Invariant ([Entity =>] type_LOCAL_NAME, [Check =>] EXPRESSION); -@end smallexample +@end example -@noindent -The @code{Type_Invariant} pragma is intended to be an exact -replacement for the language-defined @code{Type_Invariant} +The @cite{Type_Invariant} pragma is intended to be an exact +replacement for the language-defined @cite{Type_Invariant} aspect, and shares its restrictions and semantics. It differs -from the language defined @code{Invariant} pragma in that it +from the language defined @cite{Invariant} pragma in that it does not permit a string parameter, and it is -controlled by the assertion identifier @code{Type_Invariant} -rather than @code{Invariant}. - -@node Pragma Type_Invariant_Class -@unnumberedsec Pragma Type_Invariant_Class -@findex Invariant -@findex Type_Invariant_Class pragma -@noindent +controlled by the assertion identifier @cite{Type_Invariant} +rather than @cite{Invariant}. + +@node Pragma Type_Invariant_Class,Pragma Unchecked_Union,Pragma Type_Invariant,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-type-invariant-class}@anchor{cd} +@section Pragma Type_Invariant_Class + + Syntax: -@smallexample @c ada +@example pragma Type_Invariant_Class ([Entity =>] type_LOCAL_NAME, [Check =>] EXPRESSION); -@end smallexample +@end example -@noindent -The @code{Type_Invariant_Class} pragma is intended to be an exact -replacement for the language-defined @code{Type_Invariant'Class} +The @cite{Type_Invariant_Class} pragma is intended to be an exact +replacement for the language-defined @cite{Type_Invariant'Class} aspect, and shares its restrictions and semantics. -Note: This pragma is called @code{Type_Invariant_Class} rather than -@code{Type_Invariant'Class} because the latter would not be strictly +Note: This pragma is called @cite{Type_Invariant_Class} rather than +@cite{Type_Invariant'Class} because the latter would not be strictly conforming to the allowed syntax for pragmas. The motivation for providing pragmas equivalent to the aspects is to allow a program to be written using the pragmas, and then compiled if necessary using an Ada compiler that does not recognize the pragmas or aspects, but is prepared to ignore the pragmas. The assertion -policy that controls this pragma is @code{Type_Invariant'Class}, -not @code{Type_Invariant_Class}. - -@node Pragma Unchecked_Union -@unnumberedsec Pragma Unchecked_Union -@cindex Unions in C -@findex Unchecked_Union -@noindent +policy that controls this pragma is @cite{Type_Invariant'Class}, +not @cite{Type_Invariant_Class}. + +@node Pragma Unchecked_Union,Pragma Unevaluated_Use_Of_Old,Pragma Type_Invariant_Class,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-unchecked-union}@anchor{ce} +@section Pragma Unchecked_Union + + +@geindex Unions in C + Syntax: -@smallexample @c ada +@example pragma Unchecked_Union (first_subtype_LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma is used to specify a representation of a record type that is equivalent to a C union. It was introduced as a GNAT implementation defined pragma in the GNAT Ada 95 mode. Ada 2005 includes an extended version of this @@ -7384,20 +7593,23 @@ pragma, making it language defined, and GNAT fully implements this extended version in all language modes (Ada 83, Ada 95, and Ada 2005). For full details, consult the Ada 2012 Reference Manual, section B.3.3. -@node Pragma Unevaluated_Use_Of_Old -@unnumberedsec Pragma Unevaluated_Use_Of_Old -@cindex Attribute Old -@cindex Attribute Loop_Entry -@cindex Unevaluated_Use_Of_Old -@findex Unevaluated_Use_Of_Old -@noindent +@node Pragma Unevaluated_Use_Of_Old,Pragma Unimplemented_Unit,Pragma Unchecked_Union,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-unevaluated-use-of-old}@anchor{cf} +@section Pragma Unevaluated_Use_Of_Old + + +@geindex Attribute Old + +@geindex Attribute Loop_Entry + +@geindex Unevaluated_Use_Of_Old + Syntax: -@smallexample @c ada +@example pragma Unevaluated_Use_Of_Old (Error | Warn | Allow); -@end smallexample +@end example -@noindent This pragma controls the processing of attributes Old and Loop_Entry. If either of these attributes is used in a potentially unevaluated expression (e.g. the then or else parts of an if expression), then @@ -7409,15 +7621,14 @@ The reason for this rule is that otherwise, we can have a situation where we save the Old value, and this results in an exception, even though we might not evaluate the attribute. Consider this example: -@smallexample @c ada +@example package UnevalOld is K : Character; procedure U (A : String; C : Boolean) -- ERROR with Post => (if C then A(1)'Old = K else True); end; -@end smallexample +@end example -@noindent If procedure U is called with a string with a lower bound of 2, and C false, then an exception would be raised trying to evaluate A(1) on entry even though the value would not be actually used. @@ -7425,11 +7636,11 @@ on entry even though the value would not be actually used. Although the rule guarantees against this possibility, it is sometimes too restrictive. For example if we know that the string has a lower bound of 1, then we will never raise an exception. -The pragma @code{Unevaluated_Use_Of_Old} can be -used to modify this behavior. If the argument is @code{Error} then an +The pragma @cite{Unevaluated_Use_Of_Old} can be +used to modify this behavior. If the argument is @cite{Error} then an error is given (this is the default RM behavior). If the argument is -@code{Warn} then the usage is allowed as legal but with a warning -that an exception might be raised. If the argument is @code{Allow} +@cite{Warn} then the usage is allowed as legal but with a warning +that an exception might be raised. If the argument is @cite{Allow} then the usage is allowed as legal without generating a warning. This pragma may appear as a configuration pragma, or in a declarative @@ -7437,56 +7648,56 @@ part or package specification. In the latter case it applies to uses up to the end of the corresponding statement sequence or sequence of package declarations. -@node Pragma Unimplemented_Unit -@unnumberedsec Pragma Unimplemented_Unit -@findex Unimplemented_Unit -@noindent +@node Pragma Unimplemented_Unit,Pragma Universal_Aliasing,Pragma Unevaluated_Use_Of_Old,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-unimplemented-unit}@anchor{d0} +@section Pragma Unimplemented_Unit + + Syntax: -@smallexample @c ada +@example pragma Unimplemented_Unit; -@end smallexample +@end example -@noindent If this pragma occurs in a unit that is processed by the compiler, GNAT -aborts with the message @samp{@var{xxx} not implemented}, where -@var{xxx} is the name of the current compilation unit. This pragma is +aborts with the message @code{xxx not implemented}, where +@cite{xxx} is the name of the current compilation unit. This pragma is intended to allow the compiler to handle unimplemented library units in a clean manner. The abort only happens if code is being generated. Thus you can use specs of unimplemented packages in syntax or semantic checking mode. -@node Pragma Universal_Aliasing -@unnumberedsec Pragma Universal_Aliasing -@findex Universal_Aliasing -@noindent +@node Pragma Universal_Aliasing,Pragma Universal_Data,Pragma Unimplemented_Unit,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-universal-aliasing}@anchor{d1} +@section Pragma Universal_Aliasing + + Syntax: -@smallexample @c ada +@example pragma Universal_Aliasing [([Entity =>] type_LOCAL_NAME)]; -@end smallexample +@end example -@noindent -@var{type_LOCAL_NAME} must refer to a type declaration in the current +@cite{type_LOCAL_NAME} must refer to a type declaration in the current declarative part. The effect is to inhibit strict type-based aliasing optimization for the given type. In other words, the effect is as though access types designating this type were subject to pragma No_Strict_Aliasing. For a detailed description of the strict aliasing optimization, and the -situations in which it must be suppressed, @xref{Optimization and Strict -Aliasing,,, gnat_ugn, @value{EDITION} User's Guide}. +situations in which it must be suppressed, see the section on +@cite{Optimization and Strict Aliasing} in the @cite{GNAT User's Guide}. + +@node Pragma Universal_Data,Pragma Unmodified,Pragma Universal_Aliasing,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-universal-data}@anchor{d2} +@section Pragma Universal_Data + -@node Pragma Universal_Data -@unnumberedsec Pragma Universal_Data -@findex Universal_Data -@noindent Syntax: -@smallexample @c ada +@example pragma Universal_Data [(library_unit_Name)]; -@end smallexample +@end example -@noindent This pragma is supported only for the AAMP target and is ignored for other targets. The pragma specifies that all library-level objects (Counter 0 data) associated with the library unit are to be accessed @@ -7496,24 +7707,26 @@ Use of this pragma will generally result in less efficient code for references to global data associated with the library unit, but allows such data to be located anywhere in memory. This pragma is a library unit pragma, but can also be used as a configuration pragma -(including use in the @file{gnat.adc} file). The functionality +(including use in the @code{gnat.adc} file). The functionality of this pragma is also available by applying the -univ switch on the compilations of units where universal addressing of the data is desired. -@node Pragma Unmodified -@unnumberedsec Pragma Unmodified -@findex Unmodified -@cindex Warnings, unmodified -@noindent +@node Pragma Unmodified,Pragma Unreferenced,Pragma Universal_Data,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-unmodified}@anchor{d3} +@section Pragma Unmodified + + +@geindex Warnings +@geindex unmodified + Syntax: -@smallexample @c ada +@example pragma Unmodified (LOCAL_NAME @{, LOCAL_NAME@}); -@end smallexample +@end example -@noindent This pragma signals that the assignable entities (variables, -@code{out} parameters, @code{in out} parameters) whose names are listed are +@cite{out} parameters, @cite{in out} parameters) whose names are listed are deliberately not assigned in the current source unit. This suppresses warnings about the entities being referenced but not assigned, and in addition a warning will be @@ -7527,24 +7740,26 @@ be. For the variable case, warnings are never given for unreferenced variables whose name contains one of the substrings -@code{DISCARD, DUMMY, IGNORE, JUNK, UNUSED} in any casing. Such names +@cite{DISCARD@comma{} DUMMY@comma{} IGNORE@comma{} JUNK@comma{} UNUSED} in any casing. Such names are typically to be used in cases where such warnings are expected. -Thus it is never necessary to use @code{pragma Unmodified} for such +Thus it is never necessary to use @cite{pragma Unmodified} for such variables, though it is harmless to do so. -@node Pragma Unreferenced -@unnumberedsec Pragma Unreferenced -@findex Unreferenced -@cindex Warnings, unreferenced -@noindent +@node Pragma Unreferenced,Pragma Unreferenced_Objects,Pragma Unmodified,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-unreferenced}@anchor{d4} +@section Pragma Unreferenced + + +@geindex Warnings +@geindex unreferenced + Syntax: -@smallexample @c ada +@example pragma Unreferenced (LOCAL_NAME @{, LOCAL_NAME@}); pragma Unreferenced (library_unit_NAME @{, library_unit_NAME@}); -@end smallexample +@end example -@noindent This pragma signals that the entities whose names are listed are deliberately not referenced in the current source unit after the occurrence of the pragma. This @@ -7560,10 +7775,10 @@ and that this is deliberate. It can also be useful in the case of objects declared only for their initialization or finalization side effects. -If @code{LOCAL_NAME} identifies more than one matching homonym in the +If @cite{LOCAL_NAME} identifies more than one matching homonym in the current scope, then the entity most recently declared is the one to which the pragma applies. Note that in the case of accept formals, the pragma -Unreferenced may appear immediately after the keyword @code{do} which +Unreferenced may appear immediately after the keyword @cite{do} which allows the indication of whether or not accept formals are referenced or not to be given individually for each accept statement. @@ -7575,33 +7790,35 @@ Note that if a warning is desired for all calls to a given subprogram, regardless of whether they occur in the same unit as the subprogram declaration, then this pragma should not be used (calls from another unit would not be flagged); pragma Obsolescent can be used instead -for this purpose, see @xref{Pragma Obsolescent}. +for this purpose, see @ref{8b,,Pragma Obsolescent}. -The second form of pragma @code{Unreferenced} is used within a context +The second form of pragma @cite{Unreferenced} is used within a context clause. In this case the arguments must be unit names of units previously -mentioned in @code{with} clauses (similar to the usage of pragma -@code{Elaborate_All}. The effect is to suppress warnings about unreferenced +mentioned in @cite{with} clauses (similar to the usage of pragma +@cite{Elaborate_All}. The effect is to suppress warnings about unreferenced units and unreferenced entities within these units. For the variable case, warnings are never given for unreferenced variables whose name contains one of the substrings -@code{DISCARD, DUMMY, IGNORE, JUNK, UNUSED} in any casing. Such names +@cite{DISCARD@comma{} DUMMY@comma{} IGNORE@comma{} JUNK@comma{} UNUSED} in any casing. Such names are typically to be used in cases where such warnings are expected. -Thus it is never necessary to use @code{pragma Unreferenced} for such +Thus it is never necessary to use @cite{pragma Unreferenced} for such variables, though it is harmless to do so. -@node Pragma Unreferenced_Objects -@unnumberedsec Pragma Unreferenced_Objects -@findex Unreferenced_Objects -@cindex Warnings, unreferenced -@noindent +@node Pragma Unreferenced_Objects,Pragma Unreserve_All_Interrupts,Pragma Unreferenced,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-unreferenced-objects}@anchor{d5} +@section Pragma Unreferenced_Objects + + +@geindex Warnings +@geindex unreferenced + Syntax: -@smallexample @c ada +@example pragma Unreferenced_Objects (local_subtype_NAME @{, local_subtype_NAME@}); -@end smallexample +@end example -@noindent This pragma signals that for the types or subtypes whose names are listed, objects which are declared with one of these types or subtypes may not be referenced, and if no references appear, no warnings are given. @@ -7613,58 +7830,58 @@ pragma on the relevant type (most typically a limited controlled type), the compiler will automatically suppress unwanted warnings about these variables not being referenced. -@node Pragma Unreserve_All_Interrupts -@unnumberedsec Pragma Unreserve_All_Interrupts -@findex Unreserve_All_Interrupts -@noindent +@node Pragma Unreserve_All_Interrupts,Pragma Unsuppress,Pragma Unreferenced_Objects,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-unreserve-all-interrupts}@anchor{d6} +@section Pragma Unreserve_All_Interrupts + + Syntax: -@smallexample @c ada +@example pragma Unreserve_All_Interrupts; -@end smallexample +@end example -@noindent Normally certain interrupts are reserved to the implementation. Any attempt to attach an interrupt causes Program_Error to be raised, as described in -RM C.3.2(22). A typical example is the @code{SIGINT} interrupt used in -many systems for a @kbd{Ctrl-C} interrupt. Normally this interrupt is -reserved to the implementation, so that @kbd{Ctrl-C} can be used to +RM C.3.2(22). A typical example is the @cite{SIGINT} interrupt used in +many systems for a @code{Ctrl-C} interrupt. Normally this interrupt is +reserved to the implementation, so that @code{Ctrl-C} can be used to interrupt execution. -If the pragma @code{Unreserve_All_Interrupts} appears anywhere in any unit in +If the pragma @cite{Unreserve_All_Interrupts} appears anywhere in any unit in a program, then all such interrupts are unreserved. This allows the program to handle these interrupts, but disables their standard functions. For example, if this pragma is used, then pressing -@kbd{Ctrl-C} will not automatically interrupt execution. However, -a program can then handle the @code{SIGINT} interrupt as it chooses. +@code{Ctrl-C} will not automatically interrupt execution. However, +a program can then handle the @cite{SIGINT} interrupt as it chooses. For a full list of the interrupts handled in a specific implementation, -see the source code for the spec of @code{Ada.Interrupts.Names} in -file @file{a-intnam.ads}. This is a target dependent file that contains the +see the source code for the spec of @cite{Ada.Interrupts.Names} in +file @code{a-intnam.ads}. This is a target dependent file that contains the list of interrupts recognized for a given target. The documentation in this file also specifies what interrupts are affected by the use of -the @code{Unreserve_All_Interrupts} pragma. +the @cite{Unreserve_All_Interrupts} pragma. For a more general facility for controlling what interrupts can be -handled, see pragma @code{Interrupt_State}, which subsumes the functionality -of the @code{Unreserve_All_Interrupts} pragma. +handled, see pragma @cite{Interrupt_State}, which subsumes the functionality +of the @cite{Unreserve_All_Interrupts} pragma. + +@node Pragma Unsuppress,Pragma Use_VADS_Size,Pragma Unreserve_All_Interrupts,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-unsuppress}@anchor{d7} +@section Pragma Unsuppress + -@node Pragma Unsuppress -@unnumberedsec Pragma Unsuppress -@findex Unsuppress -@noindent Syntax: -@smallexample @c ada +@example pragma Unsuppress (IDENTIFIER [, [On =>] NAME]); -@end smallexample +@end example -@noindent -This pragma undoes the effect of a previous pragma @code{Suppress}. If -there is no corresponding pragma @code{Suppress} in effect, it has no +This pragma undoes the effect of a previous pragma @cite{Suppress}. If +there is no corresponding pragma @cite{Suppress} in effect, it has no effect. The range of the effect is the same as for pragma -@code{Suppress}. The meaning of the arguments is identical to that used -in pragma @code{Suppress}. +@cite{Suppress}. The meaning of the arguments is identical to that used +in pragma @cite{Suppress}. One important application is to ensure that checks are on in cases where code depends on the checks for its correct functioning, so that the code @@ -7674,31 +7891,33 @@ types and wants to ensure that the duplicated tag check occurs even if all run-time checks are suppressed by a compiler switch, the following configuration pragma will ensure this test is not suppressed: -@smallexample @c ada +@example pragma Unsuppress (Duplicated_Tag_Check); -@end smallexample +@end example -@noindent This pragma is standard in Ada 2005. It is available in all earlier versions of Ada as an implementation-defined pragma. Note that in addition to the checks defined in the Ada RM, GNAT recogizes a number of implementation-defined check names. See description of pragma -@code{Suppress} for full details. - -@node Pragma Use_VADS_Size -@unnumberedsec Pragma Use_VADS_Size -@cindex @code{Size}, VADS compatibility -@cindex Rational profile -@findex Use_VADS_Size -@noindent +@cite{Suppress} for full details. + +@node Pragma Use_VADS_Size,Pragma Validity_Checks,Pragma Unsuppress,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-use-vads-size}@anchor{d8} +@section Pragma Use_VADS_Size + + +@geindex Size +@geindex VADS compatibility + +@geindex Rational profile + Syntax: -@smallexample @c ada +@example pragma Use_VADS_Size; -@end smallexample +@end example -@noindent This is a configuration pragma. In a unit to which it applies, any use of the 'Size attribute is automatically interpreted as a use of the 'VADS_Size attribute. Note that this may result in incorrect semantic @@ -7707,76 +7926,74 @@ the handling of existing code which depends on the interpretation of Size as implemented in the VADS compiler. See description of the VADS_Size attribute for further details. -@node Pragma Validity_Checks -@unnumberedsec Pragma Validity_Checks -@findex Validity_Checks -@noindent +@node Pragma Validity_Checks,Pragma Volatile,Pragma Use_VADS_Size,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-validity-checks}@anchor{d9} +@section Pragma Validity_Checks + + Syntax: -@smallexample @c ada +@example pragma Validity_Checks (string_LITERAL | ALL_CHECKS | On | Off); -@end smallexample +@end example -@noindent This pragma is used in conjunction with compiler switches to control the -built-in validity checking provided by GNAT@. The compiler switches, if set +built-in validity checking provided by GNAT. The compiler switches, if set provide an initial setting for the switches, and this pragma may be used to modify these settings, or the settings may be provided entirely by the use of the pragma. This pragma can be used anywhere that a pragma is legal, including use as a configuration pragma (including use in -the @file{gnat.adc} file). +the @code{gnat.adc} file). The form with a string literal specifies which validity options are to be activated. The validity checks are first set to include only the default reference manual settings, and then a string of letters in the string specifies the exact set of options required. The form of this string -is exactly as described for the @option{-gnatVx} compiler switch (see the -@value{EDITION} User's Guide for details). For example the following two -methods can be used to enable validity checking for mode @code{in} and -@code{in out} subprogram parameters: +is exactly as described for the @emph{-gnatVx} compiler switch (see the +GNAT User's Guide for details). For example the following two +methods can be used to enable validity checking for mode @cite{in} and +@cite{in out} subprogram parameters: -@itemize @bullet -@item -@smallexample @c ada + +@itemize * + +@item +@example pragma Validity_Checks ("im"); -@end smallexample +@end example -@item -@smallexample -gcc -c -gnatVim @dots{} -@end smallexample +@item +@example +$ gcc -c -gnatVim ... +@end example @end itemize -@noindent The form ALL_CHECKS activates all standard checks (its use is equivalent -to the use of the @code{gnatva} switch. +to the use of the @cite{gnatva} switch. -The forms with @code{Off} and @code{On} +The forms with @cite{Off} and @cite{On} can be used to temporarily disable validity checks as shown in the following example: -@smallexample @c ada -@iftex -@leftskip=0cm -@end iftex +@example pragma Validity_Checks ("c"); -- validity checks for copies pragma Validity_Checks (Off); -- turn off validity checks A := B; -- B will not be validity checked pragma Validity_Checks (On); -- turn validity checks back on A := C; -- C will be validity checked -@end smallexample +@end example + +@node Pragma Volatile,Pragma Warning_As_Error,Pragma Validity_Checks,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-volatile}@anchor{da} +@section Pragma Volatile + -@node Pragma Volatile -@unnumberedsec Pragma Volatile -@findex Volatile -@noindent Syntax: -@smallexample @c ada +@example pragma Volatile (LOCAL_NAME); -@end smallexample +@end example -@noindent This pragma is defined by the Ada Reference Manual, and the GNAT implementation is fully conformant with this definition. The reason it is mentioned in this section is that a pragma of the same name was supplied @@ -7784,17 +8001,17 @@ in some Ada 83 compilers, including DEC Ada 83. The Ada 95 / Ada 2005 implementation of pragma Volatile is upwards compatible with the implementation in DEC Ada 83. -@node Pragma Warning_As_Error -@unnumberedsec Pragma Warning_As_Error -@findex Warning_As_Error -@noindent +@node Pragma Warning_As_Error,Pragma Warnings,Pragma Volatile,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-warning-as-error}@anchor{db} +@section Pragma Warning_As_Error + + Syntax: -@smallexample @c ada +@example pragma Warning_As_Error (static_string_EXPRESSION); -@end smallexample +@end example -@noindent This configuration pragma allows the programmer to specify a set of warnings that will be treated as errors. Any warning which matches the pattern given by the pragma argument will be treated @@ -7803,8 +8020,8 @@ which treats all warnings as errors. The pattern may contain asterisks, which match zero or more characters in the message. For example, you can use -@code{pragma Warning_As_Error ("bits of*unused")} to treat the warning -message @code{warning: 960 bits of "a" unused} as an error. No other regular +@cite{pragma Warning_As_Error ("bits of*unused")} to treat the warning +message @cite{warning: 960 bits of "a" unused} as an error. No other regular expression notations are permitted. All characters other than asterisk in these three specific cases are treated as literal characters in the match. The match is case insensitive, for example XYZ matches xyz. @@ -7814,56 +8031,54 @@ message string (it is not necessary to put an asterisk at the start and the end of the message, since this is implied). Another possibility for the static_string_EXPRESSION which works whether -or not error tags are enabled (@option{-gnatw.d}) is to use the -@option{-gnatw} tag string, enclosed in brackets, +or not error tags are enabled (@emph{-gnatw.d}) is to use the +@emph{-gnatw} tag string, enclosed in brackets, as shown in the example below, to treat a class of warnings as errors. The above use of patterns to match the message applies only to warning messages generated by the front end. This pragma can also be applied to -warnings provided by the back end and mentioned in @ref{Pragma Warnings}. -By using a single full @option{-Wxxx} switch in the pragma, such warnings +warnings provided by the back end and mentioned in @ref{dc,,Pragma Warnings}. +By using a single full @emph{-Wxxx} switch in the pragma, such warnings can also be treated as errors. The pragma can appear either in a global configuration pragma file -(e.g. @file{gnat.adc}), or at the start of a file. Given a global +(e.g. @code{gnat.adc}), or at the start of a file. Given a global configuration pragma file containing: -@smallexample @c ada +@example pragma Warning_As_Error ("[-gnatwj]"); -@end smallexample +@end example -@noindent which will treat all obsolescent feature warnings as errors, the following program compiles as shown (compile options here are -@option{-gnatwa.d -gnatl -gnatj55}). - -@smallexample @c ada - 1. pragma Warning_As_Error ("*never assigned*"); - 2. function Warnerr return String is - 3. X : Integer; - | - >>> error: variable "X" is never read and - never assigned [-gnatwv] [warning-as-error] - - 4. Y : Integer; - | - >>> warning: variable "Y" is assigned but - never read [-gnatwu] - - 5. begin - 6. Y := 0; - 7. return %ABC%; - | - >>> error: use of "%" is an obsolescent - feature (RM J.2(4)), use """ instead - [-gnatwj] [warning-as-error] - - 8. end; - - 8 lines: No errors, 3 warnings (2 treated as errors) -@end smallexample - -@noindent +@emph{-gnatwa.d -gnatl -gnatj55}). + +@example + 1. pragma Warning_As_Error ("*never assigned*"); + 2. function Warnerr return String is + 3. X : Integer; + | + >>> error: variable "X" is never read and + never assigned [-gnatwv] [warning-as-error] + + 4. Y : Integer; + | + >>> warning: variable "Y" is assigned but + never read [-gnatwu] + + 5. begin + 6. Y := 0; + 7. return %ABC%; + | + >>> error: use of "%" is an obsolescent + feature (RM J.2(4)), use """ instead + [-gnatwj] [warning-as-error] + + 8. end; + +8 lines: No errors, 3 warnings (2 treated as errors) +@end example + Note that this pragma does not affect the set of warnings issued in any way, it merely changes the effect of a matching warning if one is produced as a result of other warnings options. As shown in this @@ -7871,51 +8086,64 @@ example, if the pragma results in a warning being treated as an error, the tag is changed from "warning:" to "error:" and the string "[warning-as-error]" is appended to the end of the message. -@node Pragma Warnings -@unnumberedsec Pragma Warnings -@findex Warnings -@noindent +@node Pragma Warnings,Pragma Weak_External,Pragma Warning_As_Error,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas id5}@anchor{dd}@anchor{gnat_rm/implementation_defined_pragmas pragma-warnings}@anchor{dc} +@section Pragma Warnings + + Syntax: -@smallexample @c ada -pragma Warnings (On | Off [,REASON]); -pragma Warnings (On | Off, LOCAL_NAME [,REASON]); -pragma Warnings (static_string_EXPRESSION [,REASON]); -pragma Warnings (On | Off, static_string_EXPRESSION [,REASON]); +@example +pragma Warnings ([TOOL_NAME,] DETAILS [, REASON]); + +DETAILS ::= On | Off +DETAILS ::= On | Off, local_NAME +DETAILS ::= static_string_EXPRESSION +DETAILS ::= On | Off, static_string_EXPRESSION + +TOOL_NAME ::= GNAT | GNATProve REASON ::= Reason => STRING_LITERAL @{& STRING_LITERAL@} +@end example -Note: in Ada 83 mode, a string literal may be used in place of -a static string expression (which does not exist in Ada 83). -@end smallexample +Note: in Ada 83 mode, a string literal may be used in place of a static string +expression (which does not exist in Ada 83). + +Note if the second argument of @cite{DETAILS} is a @cite{local_NAME} then the +second form is always understood. If the intention is to use +the fourth form, then you can write @cite{NAME & ""} to force the +intepretation as a @cite{static_string_EXPRESSION}. + +Note: if the first argument is a valid @cite{TOOL_NAME}, it will be interpreted +that way. The use of the @cite{TOOL_NAME} argument is relevant only to users +of SPARK and GNATprove, see last part of this section for details. -@noindent Normally warnings are enabled, with the output being controlled by -the command line switch. Warnings (@code{Off}) turns off generation of -warnings until a Warnings (@code{On}) is encountered or the end of the +the command line switch. Warnings (@cite{Off}) turns off generation of +warnings until a Warnings (@cite{On}) is encountered or the end of the current unit. If generation of warnings is turned off using this pragma, then some or all of the warning messages are suppressed, regardless of the setting of the command line switches. -The @code{Reason} parameter may optionally appear as the last argument +The @cite{Reason} parameter may optionally appear as the last argument in any of the forms of this pragma. It is intended purely for the -purposes of documenting the reason for the @code{Warnings} pragma. +purposes of documenting the reason for the @cite{Warnings} pragma. The compiler will check that the argument is a static string but otherwise ignore this argument. Other tools may provide specialized processing for this string. The form with a single argument (or two arguments if Reason present), -where the first argument is @code{ON} or @code{OFF} +where the first argument is @cite{ON} or @cite{OFF} may be used as a configuration pragma. -If the @var{LOCAL_NAME} parameter is present, warnings are suppressed for +If the @cite{LOCAL_NAME} parameter is present, warnings are suppressed for the specified entity. This suppression is effective from the point where it occurs till the end of the extended scope of the variable (similar to -the scope of @code{Suppress}). This form cannot be used as a configuration +the scope of @cite{Suppress}). This form cannot be used as a configuration pragma. -In the case where the first argument is other than @code{ON} or -@code{OFF}, +In the case where the first argument is other than @cite{ON} or +@cite{OFF}, the third form with a single static_string_EXPRESSION argument (and possible reason) provides more precise control over which warnings are active. The string is a list of letters @@ -7924,20 +8152,19 @@ code for these letters is the same as the string used in the command line switch controlling warnings. For a brief summary, use the gnatmake command with no arguments, which will generate usage information containing the list of warnings switches supported. For -full details see @ref{Warning Message Control,,, gnat_ugn, @value{EDITION} -User's Guide}. This form can also be used as a configuration pragma. +full details see the section on @cite{Warning Message Control} in the +@cite{GNAT User's Guide}. +This form can also be used as a configuration pragma. -@noindent -The warnings controlled by the @option{-gnatw} switch are generated by the +The warnings controlled by the @emph{-gnatw} switch are generated by the front end of the compiler. The GCC back end can provide additional warnings -and they are controlled by the @option{-W} switch. Such warnings can be -identified by the appearance of a string of the form @code{[-Wxxx]} in the -message which designates the @option{-Wxxx} switch that controls the message. +and they are controlled by the @emph{-W} switch. Such warnings can be +identified by the appearance of a string of the form @cite{[-Wxxx]} in the +message which designates the @emph{-Wxxx} switch that controls the message. The form with a single static_string_EXPRESSION argument also works for these -warnings, but the string must be a single full @option{-Wxxx} switch in this +warnings, but the string must be a single full @emph{-Wxxx} switch in this case. The above reference lists a few examples of these additional warnings. -@noindent The specified warnings will be in effect until the end of the program or another pragma Warnings is encountered. The effect of the pragma is cumulative. Initially the set of warnings is the standard default set @@ -7945,15 +8172,15 @@ as possibly modified by compiler switches. Then each pragma Warning modifies this set of warnings as specified. This form of the pragma may also be used as a configuration pragma. -The fourth form, with an @code{On|Off} parameter and a string, is used to +The fourth form, with an @cite{On|Off} parameter and a string, is used to control individual messages, based on their text. The string argument is a pattern that is used to match against the text of individual warning messages (not including the initial "warning: " tag). The pattern may contain asterisks, which match zero or more characters in the message. For example, you can use -@code{pragma Warnings (Off, "bits of*unused")} to suppress the warning -message @code{warning: 960 bits of "a" unused}. No other regular +@cite{pragma Warnings (Off@comma{} "bits of*unused")} to suppress the warning +message @cite{warning: 960 bits of "a" unused}. No other regular expression notations are permitted. All characters other than asterisk in these three specific cases are treated as literal characters in the match. The match is case insensitive, for example XYZ matches xyz. @@ -7965,7 +8192,7 @@ the end of the message, since this is implied). The above use of patterns to match the message applies only to warning messages generated by the front end. This form of the pragma with a string argument can also be used to control warnings provided by the back end and -mentioned above. By using a single full @option{-Wxxx} switch in the pragma, +mentioned above. By using a single full @emph{-Wxxx} switch in the pragma, such warnings can be turned on and off. There are two ways to use the pragma in this form. The OFF form can be used @@ -7976,26 +8203,24 @@ that match the pattern string throughout the compilation (or match the The second usage is to suppress a warning locally, and in this case, two pragmas must appear in sequence: -@smallexample @c ada +@example pragma Warnings (Off, Pattern); -@dots{} code where given warning is to be suppressed +... code where given warning is to be suppressed pragma Warnings (On, Pattern); -@end smallexample +@end example -@noindent In this usage, the pattern string must match in the Off and On -pragmas, and (if @option{-gnatw.w} is given) at least one matching +pragmas, and (if @emph{-gnatw.w} is given) at least one matching warning must be suppressed. Note: to write a string that will match any warning, use the string -@code{"***"}. It will not work to use a single asterisk or two +@cite{"***"}. It will not work to use a single asterisk or two asterisks since this looks like an operator name. This form with three -asterisks is similar in effect to specifying @code{pragma Warnings -(Off)} except (if @option{-gnatw.w} is given) that a matching -@code{pragma Warnings (On, "***")} will be required. This can be +asterisks is similar in effect to specifying @cite{pragma Warnings (Off)} except (if @emph{-gnatw.w} is given) that a matching +@cite{pragma Warnings (On@comma{} "***")} will be required. This can be helpful in avoiding forgetting to turn warnings back on. -Note: the debug flag -gnatd.i (@code{/NOWARNINGS_PRAGMAS} in VMS) can be +Note: the debug flag -gnatd.i (@cite{/NOWARNINGS_PRAGMAS} in VMS) can be used to cause the compiler to entirely ignore all WARNINGS pragmas. This can be useful in checking whether obsolete pragmas in existing programs are hiding real problems. @@ -8003,21 +8228,31 @@ real problems. Note: pragma Warnings does not affect the processing of style messages. See separate entry for pragma Style_Checks for control of style messages. -@node Pragma Weak_External -@unnumberedsec Pragma Weak_External -@findex Weak_External -@noindent +Users of the formal verification tool GNATprove for the SPARK subset of Ada may +use the version of the pragma with a @cite{TOOL_NAME} parameter. + +If present, @cite{TOOL_NAME} is the name of a tool, currently either @cite{GNAT} for the +compiler or @cite{GNATprove} for the formal verification tool. A given tool only +takes into account pragma Warnings that do not specify a tool name, or that +specify the matching tool name. This makes it possible to disable warnings +selectively for each tool, and as a consequence to detect useless pragma +Warnings with switch @cite{-gnatw.w}. + +@node Pragma Weak_External,Pragma Wide_Character_Encoding,Pragma Warnings,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-weak-external}@anchor{de} +@section Pragma Weak_External + + Syntax: -@smallexample @c ada +@example pragma Weak_External ([Entity =>] LOCAL_NAME); -@end smallexample +@end example -@noindent -@var{LOCAL_NAME} must refer to an object that is declared at the library +@cite{LOCAL_NAME} must refer to an object that is declared at the library level. This pragma specifies that the given entity should be marked as a -weak symbol for the linker. It is equivalent to @code{__attribute__((weak))} -in GNU C and causes @var{LOCAL_NAME} to be emitted as a weak symbol instead +weak symbol for the linker. It is equivalent to @cite{__attribute__((weak))} +in GNU C and causes @cite{LOCAL_NAME} to be emitted as a weak symbol instead of a regular symbol, that is to say a symbol that does not have to be resolved by the linker if used in conjunction with a pragma Import. @@ -8035,7 +8270,7 @@ as shown in the example below. Some file formats do not support weak symbols so not all target machines support this pragma. -@smallexample @c ada +@example -- Example of the use of pragma Weak_External package External_Module is @@ -8052,19 +8287,19 @@ package body External_Module is return key'Address /= System.Null_Address; end Present; end External_Module; -@end smallexample +@end example + +@node Pragma Wide_Character_Encoding,,Pragma Weak_External,Implementation Defined Pragmas +@anchor{gnat_rm/implementation_defined_pragmas pragma-wide-character-encoding}@anchor{df} +@section Pragma Wide_Character_Encoding + -@node Pragma Wide_Character_Encoding -@unnumberedsec Pragma Wide_Character_Encoding -@findex Wide_Character_Encoding -@noindent Syntax: -@smallexample @c ada +@example pragma Wide_Character_Encoding (IDENTIFIER | CHARACTER_LITERAL); -@end smallexample +@end example -@noindent This pragma specifies the wide character encoding to be used in program source text appearing subsequently. It is a configuration pragma, but may also be used at any point that a pragma is allowed, and it is permissible @@ -8072,17 +8307,20 @@ to have more than one such pragma in a file, allowing multiple encodings to appear within the same file. The argument can be an identifier or a character literal. In the identifier -case, it is one of @code{HEX}, @code{UPPER}, @code{SHIFT_JIS}, -@code{EUC}, @code{UTF8}, or @code{BRACKETS}. In the character literal -case it is correspondingly one of the characters @samp{h}, @samp{u}, -@samp{s}, @samp{e}, @samp{8}, or @samp{b}. +case, it is one of @cite{HEX}, @cite{UPPER}, @cite{SHIFT_JIS}, +@cite{EUC}, @cite{UTF8}, or @cite{BRACKETS}. In the character literal +case it is correspondingly one of the characters @code{h}, @code{u}, +@code{s}, @code{e}, @code{8}, or @code{b}. Note that when the pragma is used within a file, it affects only the encoding within that file, and does not affect withed units, specs, or subunits. -@node Implementation Defined Aspects +@node Implementation Defined Aspects,Implementation Defined Attributes,Implementation Defined Pragmas,Top +@anchor{gnat_rm/implementation_defined_aspects implementation-defined-aspects}@anchor{e0}@anchor{gnat_rm/implementation_defined_aspects doc}@anchor{e1}@anchor{gnat_rm/implementation_defined_aspects id1}@anchor{e2} @chapter Implementation Defined Aspects + + Ada defines (throughout the Ada 2012 reference manual, summarized in Annex K) a set of aspects that can be specified for certain entities. These language defined aspects are implemented in GNAT in Ada 2012 mode @@ -8103,151 +8341,174 @@ Note that for many of these aspects, the effect is essentially similar to the use of a pragma or attribute specification with the same name applied to the entity. For example, if we write: -@smallexample @c ada +@example type R is range 1 .. 100 with Value_Size => 10; -@end smallexample +@end example -@noindent then the effect is the same as: -@smallexample @c ada +@example type R is range 1 .. 100; for R'Value_Size use 10; -@end smallexample +@end example -@noindent and if we write: -@smallexample @c ada +@example type R is new Integer with Shared => True; -@end smallexample +@end example -@noindent then the effect is the same as: -@smallexample @c ada +@example type R is new Integer; pragma Shared (R); -@end smallexample +@end example -@noindent In the documentation below, such cases are simply marked as being boolean aspects equivalent to the corresponding pragma or attribute definition clause. @menu -* Aspect Abstract_State:: -* Aspect Annotate:: -* Aspect Async_Readers:: -* Aspect Async_Writers:: -* Aspect Contract_Cases:: -* Aspect Depends:: -* Aspect Dimension:: -* Aspect Dimension_System:: -* Aspect Effective_Reads:: -* Aspect Effective_Writes:: -* Aspect Favor_Top_Level:: -* Aspect Global:: -* Aspect Initial_Condition:: -* Aspect Initializes:: -* Aspect Inline_Always:: -* Aspect Invariant:: -* Aspect Invariant'Class:: -* Aspect Iterable:: -* Aspect Linker_Section:: -* Aspect Lock_Free:: -* Aspect No_Elaboration_Code_All:: -* Aspect No_Tagged_Streams:: -* Aspect Object_Size:: -* Aspect Obsolescent:: -* Aspect Part_Of:: -* Aspect Persistent_BSS:: -* Aspect Predicate:: -* Aspect Pure_Function:: -* Aspect Refined_Depends:: -* Aspect Refined_Global:: -* Aspect Refined_Post:: -* Aspect Refined_State:: -* Aspect Remote_Access_Type:: -* Aspect Scalar_Storage_Order:: -* Aspect Shared:: -* Aspect Simple_Storage_Pool:: -* Aspect Simple_Storage_Pool_Type:: -* Aspect SPARK_Mode:: -* Aspect Suppress_Debug_Info:: -* Aspect Suppress_Initialization:: -* Aspect Test_Case:: -* Aspect Thread_Local_Storage:: -* Aspect Universal_Aliasing:: -* Aspect Universal_Data:: -* Aspect Unmodified:: -* Aspect Unreferenced:: -* Aspect Unreferenced_Objects:: -* Aspect Value_Size:: -* Aspect Warnings:: +* Aspect Abstract_State:: +* Annotate:: +* Aspect Async_Readers:: +* Aspect Async_Writers:: +* Aspect Contract_Cases:: +* Aspect Depends:: +* Aspect Dimension:: +* Aspect Dimension_System:: +* Aspect Effective_Reads:: +* Aspect Effective_Writes:: +* Aspect Favor_Top_Level:: +* Aspect Global:: +* Aspect Initial_Condition:: +* Aspect Initializes:: +* Aspect Inline_Always:: +* Aspect Invariant:: +* Aspect Invariant'Class:: +* Aspect Iterable:: +* Aspect Linker_Section:: +* Aspect Lock_Free:: +* Aspect No_Elaboration_Code_All:: +* Aspect No_Tagged_Streams:: +* Aspect Object_Size:: +* Aspect Obsolescent:: +* Aspect Part_Of:: +* Aspect Persistent_BSS:: +* Aspect Predicate:: +* Aspect Pure_Function:: +* Aspect Refined_Depends:: +* Aspect Refined_Global:: +* Aspect Refined_Post:: +* Aspect Refined_State:: +* Aspect Remote_Access_Type:: +* Aspect Scalar_Storage_Order:: +* Aspect Shared:: +* Aspect Simple_Storage_Pool:: +* Aspect Simple_Storage_Pool_Type:: +* Aspect SPARK_Mode:: +* Aspect Suppress_Debug_Info:: +* Aspect Suppress_Initialization:: +* Aspect Test_Case:: +* Aspect Thread_Local_Storage:: +* Aspect Universal_Aliasing:: +* Aspect Universal_Data:: +* Aspect Unmodified:: +* Aspect Unreferenced:: +* Aspect Unreferenced_Objects:: +* Aspect Value_Size:: +* Aspect Warnings:: + @end menu -@node Aspect Abstract_State -@unnumberedsec Aspect Abstract_State -@findex Abstract_State -@noindent -This aspect is equivalent to pragma @code{Abstract_State}. +@node Aspect Abstract_State,Annotate,,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-abstract-state}@anchor{e3} +@section Aspect Abstract_State + + +@geindex Abstract_State + +This aspect is equivalent to pragma @cite{Abstract_State}. + +@node Annotate,Aspect Async_Readers,Aspect Abstract_State,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects annotate}@anchor{e4} +@section Annotate + + +@geindex Annotate -@node Aspect Annotate -@unnumberedsec Annotate -@findex Annotate -@noindent There are three forms of this aspect (where ID is an identifier, and ARG is a general expression). -@table @code -@item Annotate => ID -Equivalent to @code{pragma Annotate (ID, Entity => Name);} -@item Annotate => (ID) -Equivalent to @code{pragma Annotate (ID, Entity => Name);} +@table @asis + +@item @emph{Annotate => ID} + +Equivalent to @cite{pragma Annotate (ID@comma{} Entity => Name);} + +@item @emph{Annotate => (ID)} + +Equivalent to @cite{pragma Annotate (ID@comma{} Entity => Name);} + +@item @emph{Annotate => (ID ,ID @{, ARG@})} -@item Annotate => (ID ,ID @{, ARG@}) -Equivalent to @code{pragma Annotate (ID, ID @{, ARG@}, Entity => Name);} +Equivalent to @cite{pragma Annotate (ID@comma{} ID @{@comma{} ARG@}@comma{} Entity => Name);} @end table -@node Aspect Async_Readers -@unnumberedsec Aspect Async_Readers -@findex Async_Readers -@noindent -This boolean aspect is equivalent to pragma @code{Async_Readers}. - -@node Aspect Async_Writers -@unnumberedsec Aspect Async_Writers -@findex Async_Writers -@noindent -This boolean aspect is equivalent to pragma @code{Async_Writers}. - -@node Aspect Contract_Cases -@unnumberedsec Aspect Contract_Cases -@findex Contract_Cases -@noindent -This aspect is equivalent to pragma @code{Contract_Cases}, the sequence +@node Aspect Async_Readers,Aspect Async_Writers,Annotate,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-async-readers}@anchor{e5} +@section Aspect Async_Readers + + +@geindex Async_Readers + +This boolean aspect is equivalent to pragma @cite{Async_Readers}. + +@node Aspect Async_Writers,Aspect Contract_Cases,Aspect Async_Readers,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-async-writers}@anchor{e6} +@section Aspect Async_Writers + + +@geindex Async_Writers + +This boolean aspect is equivalent to pragma @cite{Async_Writers}. + +@node Aspect Contract_Cases,Aspect Depends,Aspect Async_Writers,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-contract-cases}@anchor{e7} +@section Aspect Contract_Cases + + +@geindex Contract_Cases + +This aspect is equivalent to pragma @cite{Contract_Cases}, the sequence of clauses being enclosed in parentheses so that syntactically it is an aggregate. -@node Aspect Depends -@unnumberedsec Aspect Depends -@findex Depends -@noindent -This aspect is equivalent to pragma @code{Depends}. - -@node Aspect Dimension -@unnumberedsec Aspect Dimension -@findex Dimension -@noindent -The @code{Dimension} aspect is used to specify the dimensions of a given +@node Aspect Depends,Aspect Dimension,Aspect Contract_Cases,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-depends}@anchor{e8} +@section Aspect Depends + + +@geindex Depends + +This aspect is equivalent to pragma @cite{Depends}. + +@node Aspect Dimension,Aspect Dimension_System,Aspect Depends,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-dimension}@anchor{e9} +@section Aspect Dimension + + +@geindex Dimension + +The @cite{Dimension} aspect is used to specify the dimensions of a given subtype of a dimensioned numeric type. The aspect also specifies a symbol used when doing formatted output of dimensioned quantities. The syntax is: -@smallexample @c ada +@example with Dimension => ([Symbol =>] SYMBOL, DIMENSION_VALUE @{, DIMENSION_Value@}) @@ -8259,29 +8520,31 @@ DIMENSION_VALUE ::= | DISCRETE_CHOICE_LIST => RATIONAL RATIONAL ::= [-] NUMERIC_LITERAL [/ NUMERIC_LITERAL] -@end smallexample +@end example -@noindent This aspect can only be applied to a subtype whose parent type has -a @code{Dimension_Systen} aspect. The aspect must specify values for +a @cite{Dimension_Systen} aspect. The aspect must specify values for all dimensions of the system. The rational values are the powers of the corresponding dimensions that are used by the compiler to verify that physical (numeric) computations are dimensionally consistent. For example, the computation of a force must result in dimensions (L => 1, M => 1, T => -2). For further examples of the usage -of this aspect, see package @code{System.Dim.Mks}. +of this aspect, see package @cite{System.Dim.Mks}. Note that when the dimensioned type is an integer type, then any dimension value must be an integer literal. -@node Aspect Dimension_System -@unnumberedsec Aspect Dimension_System -@findex Dimension_System -@noindent -The @code{Dimension_System} aspect is used to define a system of +@node Aspect Dimension_System,Aspect Effective_Reads,Aspect Dimension,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-dimension-system}@anchor{ea} +@section Aspect Dimension_System + + +@geindex Dimension_System + +The @cite{Dimension_System} aspect is used to define a system of dimensions that will be used in subsequent subtype declarations with -@code{Dimension} aspects that reference this system. The syntax is: +@cite{Dimension} aspects that reference this system. The syntax is: -@smallexample @c ada +@example with Dimension_System => (DIMENSION @{, DIMENSION@}); DIMENSION ::= ([Unit_Name =>] IDENTIFIER, @@ -8289,346 +8552,513 @@ DIMENSION ::= ([Unit_Name =>] IDENTIFIER, [Dim_Symbol =>] SYMBOL) SYMBOL ::= CHARACTER_LITERAL | STRING_LITERAL -@end smallexample +@end example -@noindent This aspect is applied to a type, which must be a numeric derived type (typically a floating-point type), that -will represent values within the dimension system. Each @code{DIMENSION} +will represent values within the dimension system. Each @cite{DIMENSION} corresponds to one particular dimension. A maximum of 7 dimensions may -be specified. @code{Unit_Name} is the name of the dimension (for example -@code{Meter}). @code{Unit_Symbol} is the shorthand used for quantities -of this dimension (for example @code{m} for @code{Meter}). -@code{Dim_Symbol} gives +be specified. @cite{Unit_Name} is the name of the dimension (for example +@cite{Meter}). @cite{Unit_Symbol} is the shorthand used for quantities +of this dimension (for example @cite{m} for @cite{Meter}). +@cite{Dim_Symbol} gives the identification within the dimension system (typically this is a -single letter, e.g. @code{L} standing for length for unit name @code{Meter}). -The @code{Unit_Symbol} is used in formatted output of dimensioned quantities. -The @code{Dim_Symbol} is used in error messages when numeric operations have +single letter, e.g. @cite{L} standing for length for unit name @cite{Meter}). +The @cite{Unit_Symbol} is used in formatted output of dimensioned quantities. +The @cite{Dim_Symbol} is used in error messages when numeric operations have inconsistent dimensions. GNAT provides the standard definition of the International MKS system in -the run-time package @code{System.Dim.Mks}. You can easily define +the run-time package @cite{System.Dim.Mks}. You can easily define similar packages for cgs units or British units, and define conversion factors between values in different systems. The MKS system is characterized by the following aspect: -@smallexample @c ada - type Mks_Type is new Long_Long_Float with - Dimension_System => ( - (Unit_Name => Meter, Unit_Symbol => 'm', Dim_Symbol => 'L'), - (Unit_Name => Kilogram, Unit_Symbol => "kg", Dim_Symbol => 'M'), - (Unit_Name => Second, Unit_Symbol => 's', Dim_Symbol => 'T'), - (Unit_Name => Ampere, Unit_Symbol => 'A', Dim_Symbol => 'I'), - (Unit_Name => Kelvin, Unit_Symbol => 'K', Dim_Symbol => '@'), - (Unit_Name => Mole, Unit_Symbol => "mol", Dim_Symbol => 'N'), - (Unit_Name => Candela, Unit_Symbol => "cd", Dim_Symbol => 'J')); -@end smallexample - -@noindent -Note that in the above type definition, we use the symbol @code{@@} to +@example +type Mks_Type is new Long_Long_Float with + Dimension_System => ( + (Unit_Name => Meter, Unit_Symbol => 'm', Dim_Symbol => 'L'), + (Unit_Name => Kilogram, Unit_Symbol => "kg", Dim_Symbol => 'M'), + (Unit_Name => Second, Unit_Symbol => 's', Dim_Symbol => 'T'), + (Unit_Name => Ampere, Unit_Symbol => 'A', Dim_Symbol => 'I'), + (Unit_Name => Kelvin, Unit_Symbol => 'K', Dim_Symbol => '@@'), + (Unit_Name => Mole, Unit_Symbol => "mol", Dim_Symbol => 'N'), + (Unit_Name => Candela, Unit_Symbol => "cd", Dim_Symbol => 'J')); +@end example + +Note that in the above type definition, we use the @cite{at} symbol (@code{@@}) to represent a theta character (avoiding the use of extended Latin-1 characters in this context). -See section ``Performing Dimensionality Analysis in GNAT'' in the GNAT Users +See section 'Performing Dimensionality Analysis in GNAT' in the GNAT Users Guide for detailed examples of use of the dimension system. -@node Aspect Effective_Reads -@unnumberedsec Aspect Effective_Reads -@findex Effective_Reads -@noindent -This aspect is equivalent to pragma @code{Effective_Reads}. - -@node Aspect Effective_Writes -@unnumberedsec Aspect Effective_Writes -@findex Effective_Writes -@noindent -This aspect is equivalent to pragma @code{Effective_Writes}. - -@node Aspect Favor_Top_Level -@unnumberedsec Aspect Favor_Top_Level -@findex Favor_Top_Level -@noindent -This boolean aspect is equivalent to pragma @code{Favor_Top_Level}. - -@node Aspect Global -@unnumberedsec Aspect Global -@findex Global -@noindent -This aspect is equivalent to pragma @code{Global}. - -@node Aspect Initial_Condition -@unnumberedsec Aspect Initial_Condition -@findex Initial_Condition -@noindent -This aspect is equivalent to pragma @code{Initial_Condition}. - -@node Aspect Initializes -@unnumberedsec Aspect Initializes -@findex Initializes -@noindent -This aspect is equivalent to pragma @code{Initializes}. - -@node Aspect Inline_Always -@unnumberedsec Aspect Inline_Always -@findex Inline_Always -@noindent -This boolean aspect is equivalent to pragma @code{Inline_Always}. - -@node Aspect Invariant -@unnumberedsec Aspect Invariant -@findex Invariant -@noindent -This aspect is equivalent to pragma @code{Invariant}. It is a -synonym for the language defined aspect @code{Type_Invariant} except -that it is separately controllable using pragma @code{Assertion_Policy}. - -@node Aspect Invariant'Class -@unnumberedsec Aspect Invariant'Class -@findex Invariant'Class -@noindent -This aspect is equivalent to pragma @code{Type_Invariant_Class}. It is a -synonym for the language defined aspect @code{Type_Invariant'Class} except -that it is separately controllable using pragma @code{Assertion_Policy}. - -@node Aspect Iterable -@unnumberedsec Aspect Iterable -@findex Iterable -@noindent -This aspect is used in the GNAT-defined formal container packages, to provide -a light-weight mechanism for loops over such containers, without the overhead -imposed by the tampering checks of standard Ada2012 iterators. The value of the -aspect is a aggregate with four named components: First, Next, Has_Element, -and Element. The following is a typical example of use: - -@smallexample @c ada +@node Aspect Effective_Reads,Aspect Effective_Writes,Aspect Dimension_System,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-effective-reads}@anchor{eb} +@section Aspect Effective_Reads + + +@geindex Effective_Reads + +This aspect is equivalent to pragma @cite{Effective_Reads}. + +@node Aspect Effective_Writes,Aspect Favor_Top_Level,Aspect Effective_Reads,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-effective-writes}@anchor{ec} +@section Aspect Effective_Writes + + +@geindex Effective_Writes + +This aspect is equivalent to pragma @cite{Effective_Writes}. + +@node Aspect Favor_Top_Level,Aspect Global,Aspect Effective_Writes,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-favor-top-level}@anchor{ed} +@section Aspect Favor_Top_Level + + +@geindex Favor_Top_Level + +This boolean aspect is equivalent to pragma @cite{Favor_Top_Level}. + +@node Aspect Global,Aspect Initial_Condition,Aspect Favor_Top_Level,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-global}@anchor{ee} +@section Aspect Global + + +@geindex Global + +This aspect is equivalent to pragma @cite{Global}. + +@node Aspect Initial_Condition,Aspect Initializes,Aspect Global,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-initial-condition}@anchor{ef} +@section Aspect Initial_Condition + + +@geindex Initial_Condition + +This aspect is equivalent to pragma @cite{Initial_Condition}. + +@node Aspect Initializes,Aspect Inline_Always,Aspect Initial_Condition,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-initializes}@anchor{f0} +@section Aspect Initializes + + +@geindex Initializes + +This aspect is equivalent to pragma @cite{Initializes}. + +@node Aspect Inline_Always,Aspect Invariant,Aspect Initializes,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-inline-always}@anchor{f1} +@section Aspect Inline_Always + + +@geindex Inline_Always + +This boolean aspect is equivalent to pragma @cite{Inline_Always}. + +@node Aspect Invariant,Aspect Invariant'Class,Aspect Inline_Always,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-invariant}@anchor{f2} +@section Aspect Invariant + + +@geindex Invariant + +This aspect is equivalent to pragma @cite{Invariant}. It is a +synonym for the language defined aspect @cite{Type_Invariant} except +that it is separately controllable using pragma @cite{Assertion_Policy}. + +@node Aspect Invariant'Class,Aspect Iterable,Aspect Invariant,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-invariant-class}@anchor{f3} +@section Aspect Invariant'Class + + +@geindex Invariant'Class + +This aspect is equivalent to pragma @cite{Type_Invariant_Class}. It is a +synonym for the language defined aspect @cite{Type_Invariant'Class} except +that it is separately controllable using pragma @cite{Assertion_Policy}. + +@node Aspect Iterable,Aspect Linker_Section,Aspect Invariant'Class,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-iterable}@anchor{f4} +@section Aspect Iterable + + +@geindex Iterable + +This aspect provides a light-weight mechanism for loops and quantified +expressions over container types, without the overhead imposed by the tampering +checks of standard Ada 2012 iterators. The value of the aspect is an aggregate +with four named components: @cite{First}, @cite{Next}, @cite{Has_Element}, and @cite{Element} (the +last one being optional). When only 3 components are specified, only the +@cite{for .. in} form of iteration over cursors is available. When all 4 components +are specified, both this form and the @cite{for .. of} form of iteration over +elements are available. The following is a typical example of use: + +@example type List is private with - Iterable => (First => First_Element, + Iterable => (First => First_Cursor, Next => Advance, - Has_Element => Get_Element, - Element => List_Element); -@end smallexample -@itemize @bullet -@item The value denoted by @code{First} must denote a primitive operation of -the container type that returns a Cursor, which must a be a type declared in -the container package. -@item The value of @code{Next} is a primitive operation of the container type -that takes a cursor and yields a cursor. -@item @code{Has_Element} is an operation that applies to a cursor a yields an -element of the container. -@item @code{Element} is the type of the elements of the container type, and -thus the result of the function denoted by Has_Element. -@end itemize - -@node Aspect Linker_Section -@unnumberedsec Aspect Linker_Section -@findex Linker_Section -@noindent -This aspect is equivalent to an @code{Linker_Section} pragma. - -@node Aspect Lock_Free -@unnumberedsec Aspect Lock_Free -@findex Lock_Free -@noindent -This boolean aspect is equivalent to pragma @code{Lock_Free}. - -@node Aspect No_Elaboration_Code_All -@unnumberedsec Aspect No_Elaboration_Code_All -@findex No_Elaboration_Code_All -@noindent -This aspect is equivalent to a @code{pragma No_Elaboration_Code_All} + Has_Element => Cursor_Has_Element, + [Element => Get_Element]); +@end example + + +@itemize * + +@item +The value denoted by @cite{First} must denote a primitive operation of the +container type that returns a @cite{Cursor}, which must a be a type declared in +the container package or visible from it. For example: +@end itemize + +@example +function First_Cursor (Cont : Container) return Cursor; +@end example + + +@itemize * + +@item +The value of @cite{Next} is a primitive operation of the container type that takes +both a container and a cursor and yields a cursor. For example: +@end itemize + +@example +function Advance (Cont : Container; Position : Cursor) return Cursor; +@end example + + +@itemize * + +@item +The value of @cite{Has_Element} is a primitive operation of the container type +that takes both a container and a cursor and yields a boolean. For example: +@end itemize + +@example +function Cursor_Has_Element (Cont : Container; Position : Cursor) return Boolean; +@end example + + +@itemize * + +@item +The value of @cite{Element} is a primitive operation of the container type that +takes both a container and a cursor and yields an @cite{Element_Type}, which must +be a type declared in the container package or visible from it. For example: +@end itemize + +@example +function Get_Element (Cont : Container; Position : Cursor) return Element_Type; +@end example + +This aspect is used in the GNAT-defined formal container packages. + +@node Aspect Linker_Section,Aspect Lock_Free,Aspect Iterable,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-linker-section}@anchor{f5} +@section Aspect Linker_Section + + +@geindex Linker_Section + +This aspect is equivalent to an @cite{Linker_Section} pragma. + +@node Aspect Lock_Free,Aspect No_Elaboration_Code_All,Aspect Linker_Section,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-lock-free}@anchor{f6} +@section Aspect Lock_Free + + +@geindex Lock_Free + +This boolean aspect is equivalent to pragma @cite{Lock_Free}. + +@node Aspect No_Elaboration_Code_All,Aspect No_Tagged_Streams,Aspect Lock_Free,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-no-elaboration-code-all}@anchor{f7} +@section Aspect No_Elaboration_Code_All + + +@geindex No_Elaboration_Code_All + +This aspect is equivalent to a @cite{pragma No_Elaboration_Code_All} statement for a program unit. -@node Aspect No_Tagged_Streams -@unnumberedsec Aspect No_Tagged_Streams -@findex No_Tagged_Streams -@noindent -This aspect is equivalent to a @code{pragma No_Tagged_Streams} with an +@node Aspect No_Tagged_Streams,Aspect Object_Size,Aspect No_Elaboration_Code_All,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-no-tagged-streams}@anchor{f8} +@section Aspect No_Tagged_Streams + + +@geindex No_Tagged_Streams + +This aspect is equivalent to a @cite{pragma No_Tagged_Streams} with an argument specifying a root tagged type (thus this aspect can only be applied to such a type). -@node Aspect Object_Size -@unnumberedsec Aspect Object_Size -@findex Object_Size -@noindent -This aspect is equivalent to an @code{Object_Size} attribute definition +@node Aspect Object_Size,Aspect Obsolescent,Aspect No_Tagged_Streams,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-object-size}@anchor{f9} +@section Aspect Object_Size + + +@geindex Object_Size + +This aspect is equivalent to an @cite{Object_Size} attribute definition clause. -@node Aspect Obsolescent -@unnumberedsec Aspect Obsolescent -@findex Obsolsecent -@noindent -This aspect is equivalent to an @code{Obsolescent} pragma. Note that the +@node Aspect Obsolescent,Aspect Part_Of,Aspect Object_Size,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-obsolescent}@anchor{fa} +@section Aspect Obsolescent + + +@geindex Obsolsecent + +This aspect is equivalent to an @cite{Obsolescent} pragma. Note that the evaluation of this aspect happens at the point of occurrence, it is not delayed until the freeze point. -@node Aspect Part_Of -@unnumberedsec Aspect Part_Of -@findex Part_Of -@noindent -This aspect is equivalent to pragma @code{Part_Of}. - -@node Aspect Persistent_BSS -@unnumberedsec Aspect Persistent_BSS -@findex Persistent_BSS -@noindent -This boolean aspect is equivalent to pragma @code{Persistent_BSS}. - -@node Aspect Predicate -@unnumberedsec Aspect Predicate -@findex Predicate -@noindent -This aspect is equivalent to pragma @code{Predicate}. It is thus -similar to the language defined aspects @code{Dynamic_Predicate} -and @code{Static_Predicate} except that whether the resulting +@node Aspect Part_Of,Aspect Persistent_BSS,Aspect Obsolescent,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-part-of}@anchor{fb} +@section Aspect Part_Of + + +@geindex Part_Of + +This aspect is equivalent to pragma @cite{Part_Of}. + +@node Aspect Persistent_BSS,Aspect Predicate,Aspect Part_Of,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-persistent-bss}@anchor{fc} +@section Aspect Persistent_BSS + + +@geindex Persistent_BSS + +This boolean aspect is equivalent to pragma @cite{Persistent_BSS}. + +@node Aspect Predicate,Aspect Pure_Function,Aspect Persistent_BSS,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-predicate}@anchor{fd} +@section Aspect Predicate + + +@geindex Predicate + +This aspect is equivalent to pragma @cite{Predicate}. It is thus +similar to the language defined aspects @cite{Dynamic_Predicate} +and @cite{Static_Predicate} except that whether the resulting predicate is static or dynamic is controlled by the form of the expression. It is also separately controllable using pragma -@code{Assertion_Policy}. - -@node Aspect Pure_Function -@unnumberedsec Aspect Pure_Function -@findex Pure_Function -@noindent -This boolean aspect is equivalent to pragma @code{Pure_Function}. - -@node Aspect Refined_Depends -@unnumberedsec Aspect Refined_Depends -@findex Refined_Depends -@noindent -This aspect is equivalent to pragma @code{Refined_Depends}. - -@node Aspect Refined_Global -@unnumberedsec Aspect Refined_Global -@findex Refined_Global -@noindent -This aspect is equivalent to pragma @code{Refined_Global}. - -@node Aspect Refined_Post -@unnumberedsec Aspect Refined_Post -@findex Refined_Post -@noindent -This aspect is equivalent to pragma @code{Refined_Post}. - -@node Aspect Refined_State -@unnumberedsec Aspect Refined_State -@findex Refined_State -@noindent -This aspect is equivalent to pragma @code{Refined_State}. - -@node Aspect Remote_Access_Type -@unnumberedsec Aspect Remote_Access_Type -@findex Remote_Access_Type -@noindent -This aspect is equivalent to pragma @code{Remote_Access_Type}. - -@node Aspect Scalar_Storage_Order -@unnumberedsec Aspect Scalar_Storage_Order -@findex Scalar_Storage_Order -@noindent -This aspect is equivalent to a @code{Scalar_Storage_Order} +@cite{Assertion_Policy}. + +@node Aspect Pure_Function,Aspect Refined_Depends,Aspect Predicate,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-pure-function}@anchor{fe} +@section Aspect Pure_Function + + +@geindex Pure_Function + +This boolean aspect is equivalent to pragma @cite{Pure_Function}. + +@node Aspect Refined_Depends,Aspect Refined_Global,Aspect Pure_Function,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-refined-depends}@anchor{ff} +@section Aspect Refined_Depends + + +@geindex Refined_Depends + +This aspect is equivalent to pragma @cite{Refined_Depends}. + +@node Aspect Refined_Global,Aspect Refined_Post,Aspect Refined_Depends,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-refined-global}@anchor{100} +@section Aspect Refined_Global + + +@geindex Refined_Global + +This aspect is equivalent to pragma @cite{Refined_Global}. + +@node Aspect Refined_Post,Aspect Refined_State,Aspect Refined_Global,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-refined-post}@anchor{101} +@section Aspect Refined_Post + + +@geindex Refined_Post + +This aspect is equivalent to pragma @cite{Refined_Post}. + +@node Aspect Refined_State,Aspect Remote_Access_Type,Aspect Refined_Post,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-refined-state}@anchor{102} +@section Aspect Refined_State + + +@geindex Refined_State + +This aspect is equivalent to pragma @cite{Refined_State}. + +@node Aspect Remote_Access_Type,Aspect Scalar_Storage_Order,Aspect Refined_State,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-remote-access-type}@anchor{103} +@section Aspect Remote_Access_Type + + +@geindex Remote_Access_Type + +This aspect is equivalent to pragma @cite{Remote_Access_Type}. + +@node Aspect Scalar_Storage_Order,Aspect Shared,Aspect Remote_Access_Type,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-scalar-storage-order}@anchor{104} +@section Aspect Scalar_Storage_Order + + +@geindex Scalar_Storage_Order + +This aspect is equivalent to a @cite{Scalar_Storage_Order} attribute definition clause. -@node Aspect Shared -@unnumberedsec Aspect Shared -@findex Shared -@noindent -This booleanaspect is equivalent to pragma @code{Shared}, -and is thus a synonym for aspect @code{Atomic}. - -@node Aspect Simple_Storage_Pool -@unnumberedsec Aspect Simple_Storage_Pool -@findex Simple_Storage_Pool -@noindent -This aspect is equivalent to a @code{Simple_Storage_Pool} +@node Aspect Shared,Aspect Simple_Storage_Pool,Aspect Scalar_Storage_Order,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-shared}@anchor{105} +@section Aspect Shared + + +@geindex Shared + +This boolean aspect is equivalent to pragma @cite{Shared}, +and is thus a synonym for aspect @cite{Atomic}. + +@node Aspect Simple_Storage_Pool,Aspect Simple_Storage_Pool_Type,Aspect Shared,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-simple-storage-pool}@anchor{106} +@section Aspect Simple_Storage_Pool + + +@geindex Simple_Storage_Pool + +This aspect is equivalent to a @cite{Simple_Storage_Pool} attribute definition clause. -@node Aspect Simple_Storage_Pool_Type -@unnumberedsec Aspect Simple_Storage_Pool_Type -@findex Simple_Storage_Pool_Type -@noindent -This boolean aspect is equivalent to pragma @code{Simple_Storage_Pool_Type}. - -@node Aspect SPARK_Mode -@unnumberedsec Aspect SPARK_Mode -@findex SPARK_Mode -@noindent -This aspect is equivalent to pragma @code{SPARK_Mode} and +@node Aspect Simple_Storage_Pool_Type,Aspect SPARK_Mode,Aspect Simple_Storage_Pool,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-simple-storage-pool-type}@anchor{107} +@section Aspect Simple_Storage_Pool_Type + + +@geindex Simple_Storage_Pool_Type + +This boolean aspect is equivalent to pragma @cite{Simple_Storage_Pool_Type}. + +@node Aspect SPARK_Mode,Aspect Suppress_Debug_Info,Aspect Simple_Storage_Pool_Type,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-spark-mode}@anchor{108} +@section Aspect SPARK_Mode + + +@geindex SPARK_Mode + +This aspect is equivalent to pragma @cite{SPARK_Mode} and may be specified for either or both of the specification and body of a subprogram or package. -@node Aspect Suppress_Debug_Info -@unnumberedsec Aspect Suppress_Debug_Info -@findex Suppress_Debug_Info -@noindent -This boolean aspect is equivalent to pragma @code{Suppress_Debug_Info}. - -@node Aspect Suppress_Initialization -@unnumberedsec Aspect Suppress_Initialization -@findex Suppress_Initialization -@noindent -This boolean aspect is equivalent to pragma @code{Suppress_Initialization}. - -@node Aspect Test_Case -@unnumberedsec Aspect Test_Case -@findex Test_Case -@noindent -This aspect is equivalent to pragma @code{Test_Case}. - -@node Aspect Thread_Local_Storage -@unnumberedsec Aspect Thread_Local_Storage -@findex Thread_Local_Storage -@noindent -This boolean aspect is equivalent to pragma @code{Thread_Local_Storage}. - -@node Aspect Universal_Aliasing -@unnumberedsec Aspect Universal_Aliasing -@findex Universal_Aliasing -@noindent -This boolean aspect is equivalent to pragma @code{Universal_Aliasing}. - -@node Aspect Universal_Data -@unnumberedsec Aspect Universal_Data -@findex Universal_Data -@noindent -This aspect is equivalent to pragma @code{Universal_Data}. - -@node Aspect Unmodified -@unnumberedsec Aspect Unmodified -@findex Unmodified -@noindent -This boolean aspect is equivalent to pragma @code{Unmodified}. - -@node Aspect Unreferenced -@unnumberedsec Aspect Unreferenced -@findex Unreferenced -@noindent -This boolean aspect is equivalent to pragma @code{Unreferenced}. Note that +@node Aspect Suppress_Debug_Info,Aspect Suppress_Initialization,Aspect SPARK_Mode,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-suppress-debug-info}@anchor{109} +@section Aspect Suppress_Debug_Info + + +@geindex Suppress_Debug_Info + +This boolean aspect is equivalent to pragma @cite{Suppress_Debug_Info}. + +@node Aspect Suppress_Initialization,Aspect Test_Case,Aspect Suppress_Debug_Info,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-suppress-initialization}@anchor{10a} +@section Aspect Suppress_Initialization + + +@geindex Suppress_Initialization + +This boolean aspect is equivalent to pragma @cite{Suppress_Initialization}. + +@node Aspect Test_Case,Aspect Thread_Local_Storage,Aspect Suppress_Initialization,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-test-case}@anchor{10b} +@section Aspect Test_Case + + +@geindex Test_Case + +This aspect is equivalent to pragma @cite{Test_Case}. + +@node Aspect Thread_Local_Storage,Aspect Universal_Aliasing,Aspect Test_Case,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-thread-local-storage}@anchor{10c} +@section Aspect Thread_Local_Storage + + +@geindex Thread_Local_Storage + +This boolean aspect is equivalent to pragma @cite{Thread_Local_Storage}. + +@node Aspect Universal_Aliasing,Aspect Universal_Data,Aspect Thread_Local_Storage,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-universal-aliasing}@anchor{10d} +@section Aspect Universal_Aliasing + + +@geindex Universal_Aliasing + +This boolean aspect is equivalent to pragma @cite{Universal_Aliasing}. + +@node Aspect Universal_Data,Aspect Unmodified,Aspect Universal_Aliasing,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-universal-data}@anchor{10e} +@section Aspect Universal_Data + + +@geindex Universal_Data + +This aspect is equivalent to pragma @cite{Universal_Data}. + +@node Aspect Unmodified,Aspect Unreferenced,Aspect Universal_Data,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-unmodified}@anchor{10f} +@section Aspect Unmodified + + +@geindex Unmodified + +This boolean aspect is equivalent to pragma @cite{Unmodified}. + +@node Aspect Unreferenced,Aspect Unreferenced_Objects,Aspect Unmodified,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-unreferenced}@anchor{110} +@section Aspect Unreferenced + + +@geindex Unreferenced + +This boolean aspect is equivalent to pragma @cite{Unreferenced}. Note that in the case of formal parameters, it is not permitted to have aspects for a formal parameter, so in this case the pragma form must be used. -@node Aspect Unreferenced_Objects -@unnumberedsec Aspect Unreferenced_Objects -@findex Unreferenced_Objects -@noindent -This boolean aspect is equivalent to pragma @code{Unreferenced_Objects}. - -@node Aspect Value_Size -@unnumberedsec Aspect Value_Size -@findex Value_Size -@noindent -This aspect is equivalent to a @code{Value_Size} +@node Aspect Unreferenced_Objects,Aspect Value_Size,Aspect Unreferenced,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-unreferenced-objects}@anchor{111} +@section Aspect Unreferenced_Objects + + +@geindex Unreferenced_Objects + +This boolean aspect is equivalent to pragma @cite{Unreferenced_Objects}. + +@node Aspect Value_Size,Aspect Warnings,Aspect Unreferenced_Objects,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-value-size}@anchor{112} +@section Aspect Value_Size + + +@geindex Value_Size + +This aspect is equivalent to a @cite{Value_Size} attribute definition clause. -@node Aspect Warnings -@unnumberedsec Aspect Warnings -@findex Warnings -@noindent -This aspect is equivalent to the two argument form of pragma @code{Warnings}, -where the first argument is @code{ON} or @code{OFF} and the second argument -is the entity. +@node Aspect Warnings,,Aspect Value_Size,Implementation Defined Aspects +@anchor{gnat_rm/implementation_defined_aspects aspect-warnings}@anchor{113} +@section Aspect Warnings + + +@geindex Warnings +This aspect is equivalent to the two argument form of pragma @cite{Warnings}, +where the first argument is @cite{ON} or @cite{OFF} and the second argument +is the entity. -@node Implementation Defined Attributes +@node Implementation Defined Attributes,Standard and Implementation Defined Restrictions,Implementation Defined Aspects,Top +@anchor{gnat_rm/implementation_defined_attributes doc}@anchor{114}@anchor{gnat_rm/implementation_defined_attributes implementation-defined-attributes}@anchor{8}@anchor{gnat_rm/implementation_defined_attributes id1}@anchor{115} @chapter Implementation Defined Attributes + + Ada defines (throughout the Ada reference manual, summarized in Annex K), a set of attributes that provide useful additional functionality in all @@ -8649,165 +9079,172 @@ platforms). Therefore if portability to other compilers is an important consideration, you should minimize the use of these attributes. @menu -* Attribute Abort_Signal:: -* Attribute Address_Size:: -* Attribute Asm_Input:: -* Attribute Asm_Output:: -* Attribute AST_Entry:: -* Attribute Atomic_Always_Lock_Free:: -* Attribute Bit:: -* Attribute Bit_Position:: -* Attribute Code_Address:: -* Attribute Compiler_Version:: -* Attribute Constrained:: -* Attribute Default_Bit_Order:: -* Attribute Default_Scalar_Storage_Order:: -* Attribute Descriptor_Size:: -* Attribute Elaborated:: -* Attribute Elab_Body:: -* Attribute Elab_Spec:: -* Attribute Elab_Subp_Body:: -* Attribute Emax:: -* Attribute Enabled:: -* Attribute Enum_Rep:: -* Attribute Enum_Val:: -* Attribute Epsilon:: -* Attribute Fast_Math:: -* Attribute Fixed_Value:: -* Attribute From_Any:: -* Attribute Has_Access_Values:: -* Attribute Has_Discriminants:: -* Attribute Img:: -* Attribute Integer_Value:: -* Attribute Invalid_Value:: -* Attribute Iterable:: -* Attribute Large:: -* Attribute Library_Level:: -* Attribute Lock_Free:: -* Attribute Loop_Entry:: -* Attribute Machine_Size:: -* Attribute Mantissa:: -* Attribute Maximum_Alignment:: -* Attribute Mechanism_Code:: -* Attribute Null_Parameter:: -* Attribute Object_Size:: -* Attribute Old:: -* Attribute Passed_By_Reference:: -* Attribute Pool_Address:: -* Attribute Range_Length:: -* Attribute Ref:: -* Attribute Restriction_Set:: -* Attribute Result:: -* Attribute Safe_Emax:: -* Attribute Safe_Large:: -* Attribute Safe_Small:: -* Attribute Scalar_Storage_Order:: -* Attribute Simple_Storage_Pool:: -* Attribute Small:: -* Attribute Storage_Unit:: -* Attribute Stub_Type:: -* Attribute System_Allocator_Alignment:: -* Attribute Target_Name:: -* Attribute To_Address:: -* Attribute To_Any:: -* Attribute Type_Class:: -* Attribute Type_Key:: -* Attribute TypeCode:: -* Attribute UET_Address:: -* Attribute Unconstrained_Array:: -* Attribute Universal_Literal_String:: -* Attribute Unrestricted_Access:: -* Attribute Update:: -* Attribute VADS_Size:: -* Attribute Valid_Scalars:: -* Attribute Value_Size:: -* Attribute Wchar_T_Size:: -* Attribute Word_Size:: +* Attribute Abort_Signal:: +* Attribute Address_Size:: +* Attribute Asm_Input:: +* Attribute Asm_Output:: +* Attribute Atomic_Always_Lock_Free:: +* Attribute Bit:: +* Attribute Bit_Position:: +* Attribute Code_Address:: +* Attribute Compiler_Version:: +* Attribute Constrained:: +* Attribute Default_Bit_Order:: +* Attribute Default_Scalar_Storage_Order:: +* Attribute Descriptor_Size:: +* Attribute Elaborated:: +* Attribute Elab_Body:: +* Attribute Elab_Spec:: +* Attribute Elab_Subp_Body:: +* Attribute Emax:: +* Attribute Enabled:: +* Attribute Enum_Rep:: +* Attribute Enum_Val:: +* Attribute Epsilon:: +* Attribute Fast_Math:: +* Attribute Fixed_Value:: +* Attribute From_Any:: +* Attribute Has_Access_Values:: +* Attribute Has_Discriminants:: +* Attribute Img:: +* Attribute Integer_Value:: +* Attribute Invalid_Value:: +* Attribute Iterable:: +* Attribute Large:: +* Attribute Library_Level:: +* Attribute Lock_Free:: +* Attribute Loop_Entry:: +* Attribute Machine_Size:: +* Attribute Mantissa:: +* Attribute Maximum_Alignment:: +* Attribute Mechanism_Code:: +* Attribute Null_Parameter:: +* Attribute Object_Size:: +* Attribute Old:: +* Attribute Passed_By_Reference:: +* Attribute Pool_Address:: +* Attribute Range_Length:: +* Attribute Ref:: +* Attribute Restriction_Set:: +* Attribute Result:: +* Attribute Safe_Emax:: +* Attribute Safe_Large:: +* Attribute Safe_Small:: +* Attribute Scalar_Storage_Order:: +* Attribute Simple_Storage_Pool:: +* Attribute Small:: +* Attribute Storage_Unit:: +* Attribute Stub_Type:: +* Attribute System_Allocator_Alignment:: +* Attribute Target_Name:: +* Attribute To_Address:: +* Attribute To_Any:: +* Attribute Type_Class:: +* Attribute Type_Key:: +* Attribute TypeCode:: +* Attribute UET_Address:: +* Attribute Unconstrained_Array:: +* Attribute Universal_Literal_String:: +* Attribute Unrestricted_Access:: +* Attribute Update:: +* Attribute Valid_Scalars:: +* Attribute VADS_Size:: +* Attribute Value_Size:: +* Attribute Wchar_T_Size:: +* Attribute Word_Size:: + @end menu -@node Attribute Abort_Signal -@unnumberedsec Attribute Abort_Signal -@findex Abort_Signal -@noindent -@code{Standard'Abort_Signal} (@code{Standard} is the only allowed +@node Attribute Abort_Signal,Attribute Address_Size,,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-abort-signal}@anchor{116} +@section Attribute Abort_Signal + + +@geindex Abort_Signal + +@cite{Standard'Abort_Signal} (@cite{Standard} is the only allowed prefix) provides the entity for the special exception used to signal task abort or asynchronous transfer of control. Normally this attribute should only be used in the tasking runtime (it is highly peculiar, and completely outside the normal semantics of Ada, for a user program to intercept the abort exception). -@node Attribute Address_Size -@unnumberedsec Attribute Address_Size -@cindex Size of @code{Address} -@findex Address_Size -@noindent -@code{Standard'Address_Size} (@code{Standard} is the only allowed +@node Attribute Address_Size,Attribute Asm_Input,Attribute Abort_Signal,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-address-size}@anchor{117} +@section Attribute Address_Size + + +@geindex Size of `Address` + +@geindex Address_Size + +@cite{Standard'Address_Size} (@cite{Standard} is the only allowed prefix) is a static constant giving the number of bits in an -@code{Address}. It is the same value as System.Address'Size, +@cite{Address}. It is the same value as System.Address'Size, but has the advantage of being static, while a direct reference to System.Address'Size is non-static because Address is a private type. -@node Attribute Asm_Input -@unnumberedsec Attribute Asm_Input -@findex Asm_Input -@noindent -The @code{Asm_Input} attribute denotes a function that takes two +@node Attribute Asm_Input,Attribute Asm_Output,Attribute Address_Size,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-asm-input}@anchor{118} +@section Attribute Asm_Input + + +@geindex Asm_Input + +The @cite{Asm_Input} attribute denotes a function that takes two parameters. The first is a string, the second is an expression of the type designated by the prefix. The first (string) argument is required to be a static expression, and is the constraint for the parameter, -(e.g.@: what kind of register is required). The second argument is the +(e.g., what kind of register is required). The second argument is the value to be used as the input argument. The possible values for the constant are the same as those used in the RTL, and are dependent on the configuration file used to built the GCC back end. -@ref{Machine Code Insertions} +@ref{119,,Machine Code Insertions} -@node Attribute Asm_Output -@unnumberedsec Attribute Asm_Output -@findex Asm_Output -@noindent -The @code{Asm_Output} attribute denotes a function that takes two +@node Attribute Asm_Output,Attribute Atomic_Always_Lock_Free,Attribute Asm_Input,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-asm-output}@anchor{11a} +@section Attribute Asm_Output + + +@geindex Asm_Output + +The @cite{Asm_Output} attribute denotes a function that takes two parameters. The first is a string, the second is the name of a variable of the type designated by the attribute prefix. The first (string) argument is required to be a static expression and designates the -constraint for the parameter (e.g.@: what kind of register is +constraint for the parameter (e.g., what kind of register is required). The second argument is the variable to be updated with the result. The possible values for constraint are the same as those used in the RTL, and are dependent on the configuration file used to build the GCC back end. If there are no output operands, then this argument may -either be omitted, or explicitly given as @code{No_Output_Operands}. -@ref{Machine Code Insertions} - -@node Attribute AST_Entry -@unnumberedsec Attribute AST_Entry -@cindex OpenVMS -@findex AST_Entry -@noindent -This attribute is implemented only in OpenVMS versions of GNAT@. Applied to -the name of an entry, it yields a value of the predefined type AST_Handler -(declared in the predefined package System, as extended by the use of -pragma @code{Extend_System (Aux_DEC)}). This value enables the given entry to -be called when an AST occurs. For further details, refer to the @cite{DEC Ada -Language Reference Manual}, section 9.12a. - -@node Attribute Atomic_Always_Lock_Free -@unnumberedsec Attribute Atomic_Always_Lock_Free -@findex Atomic_Always_Lock_Free -@noindent - -The prefix of the @code{Atomic_Always_Lock_Free} attribute is a type. +either be omitted, or explicitly given as @cite{No_Output_Operands}. +@ref{119,,Machine Code Insertions} + +@node Attribute Atomic_Always_Lock_Free,Attribute Bit,Attribute Asm_Output,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-atomic-always-lock-free}@anchor{11b} +@section Attribute Atomic_Always_Lock_Free + + +@geindex Atomic_Always_Lock_Free + +The prefix of the @cite{Atomic_Always_Lock_Free} attribute is a type. The result is a Boolean value which is True if the type has discriminants, and False otherwise. The result indicate whether atomic operations are supported by the target for the given type. -@node Attribute Bit -@unnumberedsec Attribute Bit -@findex Bit -@code{@var{obj}'Bit}, where @var{obj} is any object, yields the bit +@node Attribute Bit,Attribute Bit_Position,Attribute Atomic_Always_Lock_Free,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-bit}@anchor{11c} +@section Attribute Bit + + +@geindex Bit + +@code{obj'Bit}, where @cite{obj} is any object, yields the bit offset within the storage unit (byte) that contains the first bit of storage allocated for the object. The value of this attribute is of the -type @code{Universal_Integer}, and is always a non-negative number not -exceeding the value of @code{System.Storage_Unit}. +type @cite{Universal_Integer}, and is always a non-negative number not +exceeding the value of @cite{System.Storage_Unit}. For an object that is a variable or a constant allocated in a register, the value is zero. (The use of this attribute does not force the @@ -8818,141 +9255,168 @@ to either the matching actual parameter or to a copy of the matching actual parameter. For an access object the value is zero. Note that -@code{@var{obj}.all'Bit} is subject to an @code{Access_Check} for the +@code{obj.all'Bit} is subject to an @cite{Access_Check} for the designated object. Similarly for a record component -@code{@var{X}.@var{C}'Bit} is subject to a discriminant check and -@code{@var{X}(@var{I}).Bit} and @code{@var{X}(@var{I1}..@var{I2})'Bit} +@code{X.C'Bit} is subject to a discriminant check and +@code{X(I).Bit} and @code{X(I1..I2)'Bit} are subject to index checks. This attribute is designed to be compatible with the DEC Ada 83 definition -and implementation of the @code{Bit} attribute. +and implementation of the @cite{Bit} attribute. + +@node Attribute Bit_Position,Attribute Code_Address,Attribute Bit,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-bit-position}@anchor{11d} +@section Attribute Bit_Position + -@node Attribute Bit_Position -@unnumberedsec Attribute Bit_Position -@findex Bit_Position -@noindent -@code{@var{R.C}'Bit_Position}, where @var{R} is a record object and C is one +@geindex Bit_Position + +@code{R.C'Bit_Position}, where @cite{R} is a record object and @cite{C} is one of the fields of the record type, yields the bit offset within the record contains the first bit of storage allocated for the object. The value of this attribute is of the -type @code{Universal_Integer}. The value depends only on the field -@var{C} and is independent of the alignment of -the containing record @var{R}. - -@node Attribute Code_Address -@unnumberedsec Attribute Code_Address -@findex Code_Address -@cindex Subprogram address -@cindex Address of subprogram code -@noindent -The @code{'Address} +type @cite{Universal_Integer}. The value depends only on the field +@cite{C} and is independent of the alignment of +the containing record @cite{R}. + +@node Attribute Code_Address,Attribute Compiler_Version,Attribute Bit_Position,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-code-address}@anchor{11e} +@section Attribute Code_Address + + +@geindex Code_Address + +@geindex Subprogram address + +@geindex Address of subprogram code + +The @cite{'Address} attribute may be applied to subprograms in Ada 95 and Ada 2005, but the intended effect seems to be to provide an address value which can be used to call the subprogram by means of an address clause as in the following example: -@smallexample @c ada -procedure K is @dots{} +@example +procedure K is ... procedure L; for L'Address use K'Address; pragma Import (Ada, L); -@end smallexample +@end example -@noindent -A call to @code{L} is then expected to result in a call to @code{K}@. +A call to @cite{L} is then expected to result in a call to @cite{K}. In Ada 83, where there were no access-to-subprogram values, this was a common work-around for getting the effect of an indirect call. -GNAT implements the above use of @code{Address} and the technique +GNAT implements the above use of @cite{Address} and the technique illustrated by the example code works correctly. However, for some purposes, it is useful to have the address of the start of the generated code for the subprogram. On some architectures, this is -not necessarily the same as the @code{Address} value described above. -For example, the @code{Address} value may reference a subprogram +not necessarily the same as the @cite{Address} value described above. +For example, the @cite{Address} value may reference a subprogram descriptor rather than the subprogram itself. -The @code{'Code_Address} attribute, which can only be applied to +The @cite{'Code_Address} attribute, which can only be applied to subprogram entities, always returns the address of the start of the generated code of the specified subprogram, which may or may not be -the same value as is returned by the corresponding @code{'Address} +the same value as is returned by the corresponding @cite{'Address} attribute. -@node Attribute Compiler_Version -@unnumberedsec Attribute Compiler_Version -@findex Compiler_Version -@noindent -@code{Standard'Compiler_Version} (@code{Standard} is the only allowed +@node Attribute Compiler_Version,Attribute Constrained,Attribute Code_Address,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-compiler-version}@anchor{11f} +@section Attribute Compiler_Version + + +@geindex Compiler_Version + +@cite{Standard'Compiler_Version} (@cite{Standard} is the only allowed prefix) yields a static string identifying the version of the compiler -being used to compile the unit containing the attribute reference. A -typical result would be something like -"@value{EDITION} @value{gnat_version} (20090221)". - -@node Attribute Constrained -@unnumberedsec Attribute Constrained -@findex Constrained -@noindent -In addition to the usage of this attribute in the Ada RM, @code{GNAT} -also permits the use of the @code{'Constrained} attribute +being used to compile the unit containing the attribute reference. + +@node Attribute Constrained,Attribute Default_Bit_Order,Attribute Compiler_Version,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-constrained}@anchor{120} +@section Attribute Constrained + + +@geindex Constrained + +In addition to the usage of this attribute in the Ada RM, @cite{GNAT} +also permits the use of the @cite{'Constrained} attribute in a generic template for any type, including types without discriminants. The value of this attribute in the generic instance when applied to a scalar type or a -record type without discriminants is always @code{True}. This usage is +record type without discriminants is always @cite{True}. This usage is compatible with older Ada compilers, including notably DEC Ada. -@node Attribute Default_Bit_Order -@unnumberedsec Attribute Default_Bit_Order -@cindex Big endian -@cindex Little endian -@findex Default_Bit_Order -@noindent -@code{Standard'Default_Bit_Order} (@code{Standard} is the only -permissible prefix), provides the value @code{System.Default_Bit_Order} -as a @code{Pos} value (0 for @code{High_Order_First}, 1 for -@code{Low_Order_First}). This is used to construct the definition of -@code{Default_Bit_Order} in package @code{System}. - -@node Attribute Default_Scalar_Storage_Order -@unnumberedsec Attribute Default_Scalar_Storage_Order -@cindex Big endian -@cindex Little endian -@findex Default_Scalar_Storage_Order -@noindent -@code{Standard'Default_Scalar_Storage_Order} (@code{Standard} is the only +@node Attribute Default_Bit_Order,Attribute Default_Scalar_Storage_Order,Attribute Constrained,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-default-bit-order}@anchor{121} +@section Attribute Default_Bit_Order + + +@geindex Big endian + +@geindex Little endian + +@geindex Default_Bit_Order + +@cite{Standard'Default_Bit_Order} (@cite{Standard} is the only +permissible prefix), provides the value @cite{System.Default_Bit_Order} +as a @cite{Pos} value (0 for @cite{High_Order_First}, 1 for +@cite{Low_Order_First}). This is used to construct the definition of +@cite{Default_Bit_Order} in package @cite{System}. + +@node Attribute Default_Scalar_Storage_Order,Attribute Descriptor_Size,Attribute Default_Bit_Order,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-default-scalar-storage-order}@anchor{122} +@section Attribute Default_Scalar_Storage_Order + + +@geindex Big endian + +@geindex Little endian + +@geindex Default_Scalar_Storage_Order + +@cite{Standard'Default_Scalar_Storage_Order} (@cite{Standard} is the only permissible prefix), provides the current value of the default scalar storage -order (as specified using pragma @code{Default_Scalar_Storage_Order}, or -equal to @code{Default_Bit_Order} if unspecified) as a -@code{System.Bit_Order} value. This is a static attribute. - -@node Attribute Descriptor_Size -@unnumberedsec Attribute Descriptor_Size -@cindex Descriptor -@cindex Dope vector -@findex Descriptor_Size -@noindent -Non-static attribute @code{Descriptor_Size} returns the size in bits of the +order (as specified using pragma @cite{Default_Scalar_Storage_Order}, or +equal to @cite{Default_Bit_Order} if unspecified) as a +@cite{System.Bit_Order} value. This is a static attribute. + +@node Attribute Descriptor_Size,Attribute Elaborated,Attribute Default_Scalar_Storage_Order,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-descriptor-size}@anchor{123} +@section Attribute Descriptor_Size + + +@geindex Descriptor + +@geindex Dope vector + +@geindex Descriptor_Size + +Non-static attribute @cite{Descriptor_Size} returns the size in bits of the descriptor allocated for a type. The result is non-zero only for unconstrained array types and the returned value is of type universal integer. In GNAT, an array descriptor contains bounds information and is located immediately before the first element of the array. -@smallexample @c ada +@example type Unconstr_Array is array (Positive range <>) of Boolean; Put_Line ("Descriptor size = " & Unconstr_Array'Descriptor_Size'Img); -@end smallexample +@end example -@noindent The attribute takes into account any additional padding due to type alignment. In the example above, the descriptor contains two values of type -@code{Positive} representing the low and high bound. Since @code{Positive} has -a size of 31 bits and an alignment of 4, the descriptor size is @code{2 * -Positive'Size + 2} or 64 bits. - -@node Attribute Elaborated -@unnumberedsec Attribute Elaborated -@findex Elaborated -@noindent -The prefix of the @code{'Elaborated} attribute must be a unit name. The +@cite{Positive} representing the low and high bound. Since @cite{Positive} has +a size of 31 bits and an alignment of 4, the descriptor size is @cite{2 * Positive'Size + 2} or 64 bits. + +@node Attribute Elaborated,Attribute Elab_Body,Attribute Descriptor_Size,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-elaborated}@anchor{124} +@section Attribute Elaborated + + +@geindex Elaborated + +The prefix of the @cite{'Elaborated} attribute must be a unit name. The value is a Boolean which indicates whether or not the given unit has been elaborated. This attribute is primarily intended for internal use by the generated code for dynamic elaboration checking, but it can also be used @@ -8960,36 +9424,45 @@ in user programs. The value will always be True once elaboration of all units has been completed. An exception is for units which need no elaboration, the value is always False for such units. -@node Attribute Elab_Body -@unnumberedsec Attribute Elab_Body -@findex Elab_Body -@noindent +@node Attribute Elab_Body,Attribute Elab_Spec,Attribute Elaborated,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-elab-body}@anchor{125} +@section Attribute Elab_Body + + +@geindex Elab_Body + This attribute can only be applied to a program unit name. It returns the entity for the corresponding elaboration procedure for elaborating the body of the referenced unit. This is used in the main generated elaboration procedure by the binder and is not normally used in any other context. However, there may be specialized situations in which it is useful to be able to call this elaboration procedure from Ada code, -e.g.@: if it is necessary to do selective re-elaboration to fix some +e.g., if it is necessary to do selective re-elaboration to fix some error. -@node Attribute Elab_Spec -@unnumberedsec Attribute Elab_Spec -@findex Elab_Spec -@noindent +@node Attribute Elab_Spec,Attribute Elab_Subp_Body,Attribute Elab_Body,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-elab-spec}@anchor{126} +@section Attribute Elab_Spec + + +@geindex Elab_Spec + This attribute can only be applied to a program unit name. It returns the entity for the corresponding elaboration procedure for elaborating the spec of the referenced unit. This is used in the main generated elaboration procedure by the binder and is not normally used in any other context. However, there may be specialized situations in which it is useful to be able to call this elaboration procedure from -Ada code, e.g.@: if it is necessary to do selective re-elaboration to fix +Ada code, e.g., if it is necessary to do selective re-elaboration to fix some error. -@node Attribute Elab_Subp_Body -@unnumberedsec Attribute Elab_Subp_Body -@findex Elab_Subp_Body -@noindent +@node Attribute Elab_Subp_Body,Attribute Emax,Attribute Elab_Spec,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-elab-subp-body}@anchor{127} +@section Attribute Elab_Subp_Body + + +@geindex Elab_Subp_Body + This attribute can only be applied to a library level subprogram name and is only allowed in CodePeer mode. It returns the entity for the corresponding elaboration procedure for elaborating the body @@ -8997,149 +9470,175 @@ of the referenced subprogram unit. This is used in the main generated elaboration procedure by the binder in CodePeer mode only and is unrecognized otherwise. -@node Attribute Emax -@unnumberedsec Attribute Emax -@cindex Ada 83 attributes -@findex Emax -@noindent -The @code{Emax} attribute is provided for compatibility with Ada 83. See +@node Attribute Emax,Attribute Enabled,Attribute Elab_Subp_Body,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-emax}@anchor{128} +@section Attribute Emax + + +@geindex Ada 83 attributes + +@geindex Emax + +The @cite{Emax} attribute is provided for compatibility with Ada 83. See the Ada 83 reference manual for an exact description of the semantics of this attribute. -@node Attribute Enabled -@unnumberedsec Attribute Enabled -@findex Enabled -@noindent -The @code{Enabled} attribute allows an application program to check at compile +@node Attribute Enabled,Attribute Enum_Rep,Attribute Emax,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-enabled}@anchor{129} +@section Attribute Enabled + + +@geindex Enabled + +The @cite{Enabled} attribute allows an application program to check at compile time to see if the designated check is currently enabled. The prefix is a simple identifier, referencing any predefined check name (other than -@code{All_Checks}) or a check name introduced by pragma Check_Name. If +@cite{All_Checks}) or a check name introduced by pragma Check_Name. If no argument is given for the attribute, the check is for the general state of the check, if an argument is given, then it is an entity name, and the -check indicates whether an @code{Suppress} or @code{Unsuppress} has been +check indicates whether an @cite{Suppress} or @cite{Unsuppress} has been given naming the entity (if not, then the argument is ignored). Note that instantiations inherit the check status at the point of the instantiation, so a useful idiom is to have a library package that -introduces a check name with @code{pragma Check_Name}, and then contains -generic packages or subprograms which use the @code{Enabled} attribute +introduces a check name with @cite{pragma Check_Name}, and then contains +generic packages or subprograms which use the @cite{Enabled} attribute to see if the check is enabled. A user of this package can then issue -a @code{pragma Suppress} or @code{pragma Unsuppress} before instantiating +a @cite{pragma Suppress} or @cite{pragma Unsuppress} before instantiating the package or subprogram, controlling whether the check will be present. -@node Attribute Enum_Rep -@unnumberedsec Attribute Enum_Rep -@cindex Representation of enums -@findex Enum_Rep -@noindent -For every enumeration subtype @var{S}, @code{@var{S}'Enum_Rep} denotes a +@node Attribute Enum_Rep,Attribute Enum_Val,Attribute Enabled,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-enum-rep}@anchor{12a} +@section Attribute Enum_Rep + + +@geindex Representation of enums + +@geindex Enum_Rep + +For every enumeration subtype @cite{S}, @code{S'Enum_Rep} denotes a function with the following spec: -@smallexample @c ada -function @var{S}'Enum_Rep (Arg : @var{S}'Base) - return @i{Universal_Integer}; -@end smallexample +@example +function S'Enum_Rep (Arg : S'Base) return <Universal_Integer>; +@end example -@noindent -It is also allowable to apply @code{Enum_Rep} directly to an object of an +It is also allowable to apply @cite{Enum_Rep} directly to an object of an enumeration type or to a non-overloaded enumeration -literal. In this case @code{@var{S}'Enum_Rep} is equivalent to -@code{@var{typ}'Enum_Rep(@var{S})} where @var{typ} is the type of the +literal. In this case @code{S'Enum_Rep} is equivalent to +@code{typ'Enum_Rep(S)} where @cite{typ} is the type of the enumeration literal or object. The function returns the representation value for the given enumeration -value. This will be equal to value of the @code{Pos} attribute in the +value. This will be equal to value of the @cite{Pos} attribute in the absence of an enumeration representation clause. This is a static -attribute (i.e.@: the result is static if the argument is static). +attribute (i.e.,:the result is static if the argument is static). -@code{@var{S}'Enum_Rep} can also be used with integer types and objects, +@code{S'Enum_Rep} can also be used with integer types and objects, in which case it simply returns the integer value. The reason for this -is to allow it to be used for @code{(<>)} discrete formal arguments in +is to allow it to be used for @cite{(<>)} discrete formal arguments in a generic unit that can be instantiated with either enumeration types -or integer types. Note that if @code{Enum_Rep} is used on a modular +or integer types. Note that if @cite{Enum_Rep} is used on a modular type whose upper bound exceeds the upper bound of the largest signed integer type, and the argument is a variable, so that the universal -integer calculation is done at run time, then the call to @code{Enum_Rep} -may raise @code{Constraint_Error}. - -@node Attribute Enum_Val -@unnumberedsec Attribute Enum_Val -@cindex Representation of enums -@findex Enum_Val -@noindent -For every enumeration subtype @var{S}, @code{@var{S}'Enum_Val} denotes a +integer calculation is done at run time, then the call to @cite{Enum_Rep} +may raise @cite{Constraint_Error}. + +@node Attribute Enum_Val,Attribute Epsilon,Attribute Enum_Rep,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-enum-val}@anchor{12b} +@section Attribute Enum_Val + + +@geindex Representation of enums + +@geindex Enum_Val + +For every enumeration subtype @cite{S}, @code{S'Enum_Val} denotes a function with the following spec: -@smallexample @c ada -function @var{S}'Enum_Val (Arg : @i{Universal_Integer) - return @var{S}'Base}; -@end smallexample +@example +function S'Enum_Val (Arg : <Universal_Integer>) return S'Base; +@end example -@noindent The function returns the enumeration value whose representation matches the argument, or raises Constraint_Error if no enumeration literal of the type has the matching value. -This will be equal to value of the @code{Val} attribute in the +This will be equal to value of the @cite{Val} attribute in the absence of an enumeration representation clause. This is a static -attribute (i.e.@: the result is static if the argument is static). - -@node Attribute Epsilon -@unnumberedsec Attribute Epsilon -@cindex Ada 83 attributes -@findex Epsilon -@noindent -The @code{Epsilon} attribute is provided for compatibility with Ada 83. See +attribute (i.e., the result is static if the argument is static). + +@node Attribute Epsilon,Attribute Fast_Math,Attribute Enum_Val,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-epsilon}@anchor{12c} +@section Attribute Epsilon + + +@geindex Ada 83 attributes + +@geindex Epsilon + +The @cite{Epsilon} attribute is provided for compatibility with Ada 83. See the Ada 83 reference manual for an exact description of the semantics of this attribute. -@node Attribute Fast_Math -@unnumberedsec Attribute Fast_Math -@findex Fast_Math -@noindent -@code{Standard'Fast_Math} (@code{Standard} is the only allowed +@node Attribute Fast_Math,Attribute Fixed_Value,Attribute Epsilon,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-fast-math}@anchor{12d} +@section Attribute Fast_Math + + +@geindex Fast_Math + +@cite{Standard'Fast_Math} (@cite{Standard} is the only allowed prefix) yields a static Boolean value that is True if pragma -@code{Fast_Math} is active, and False otherwise. +@cite{Fast_Math} is active, and False otherwise. -@node Attribute Fixed_Value -@unnumberedsec Attribute Fixed_Value -@findex Fixed_Value -@noindent -For every fixed-point type @var{S}, @code{@var{S}'Fixed_Value} denotes a +@node Attribute Fixed_Value,Attribute From_Any,Attribute Fast_Math,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-fixed-value}@anchor{12e} +@section Attribute Fixed_Value + + +@geindex Fixed_Value + +For every fixed-point type @cite{S}, @code{S'Fixed_Value} denotes a function with the following specification: -@smallexample @c ada -function @var{S}'Fixed_Value (Arg : @i{Universal_Integer}) - return @var{S}; -@end smallexample +@example +function S'Fixed_Value (Arg : <Universal_Integer>) return S; +@end example -@noindent -The value returned is the fixed-point value @var{V} such that +The value returned is the fixed-point value @cite{V} such that: -@smallexample @c ada -@var{V} = Arg * @var{S}'Small -@end smallexample +@example +V = Arg * S'Small +@end example -@noindent The effect is thus similar to first converting the argument to the -integer type used to represent @var{S}, and then doing an unchecked +integer type used to represent @cite{S}, and then doing an unchecked conversion to the fixed-point type. The difference is that there are full range checks, to ensure that the result is in range. This attribute is primarily intended for use in implementation of the input-output functions for fixed-point values. -@node Attribute From_Any -@unnumberedsec Attribute From_Any -@findex From_Any -@noindent +@node Attribute From_Any,Attribute Has_Access_Values,Attribute Fixed_Value,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-from-any}@anchor{12f} +@section Attribute From_Any + + +@geindex From_Any + This internal attribute is used for the generation of remote subprogram stubs in the context of the Distributed Systems Annex. -@node Attribute Has_Access_Values -@unnumberedsec Attribute Has_Access_Values -@cindex Access values, testing for -@findex Has_Access_Values -@noindent -The prefix of the @code{Has_Access_Values} attribute is a type. The result +@node Attribute Has_Access_Values,Attribute Has_Discriminants,Attribute From_Any,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-has-access-values}@anchor{130} +@section Attribute Has_Access_Values + + +@geindex Access values +@geindex testing for + +@geindex Has_Access_Values + +The prefix of the @cite{Has_Access_Values} attribute is a type. The result is a Boolean value which is True if the is an access type, or is a composite type with a component (at any nesting depth) that is an access type, and is False otherwise. @@ -9147,67 +9646,73 @@ The intended use of this attribute is in conjunction with generic definitions. If the attribute is applied to a generic private type, it indicates whether or not the corresponding actual type has access values. -@node Attribute Has_Discriminants -@unnumberedsec Attribute Has_Discriminants -@cindex Discriminants, testing for -@findex Has_Discriminants -@noindent -The prefix of the @code{Has_Discriminants} attribute is a type. The result +@node Attribute Has_Discriminants,Attribute Img,Attribute Has_Access_Values,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-has-discriminants}@anchor{131} +@section Attribute Has_Discriminants + + +@geindex Discriminants +@geindex testing for + +@geindex Has_Discriminants + +The prefix of the @cite{Has_Discriminants} attribute is a type. The result is a Boolean value which is True if the type has discriminants, and False otherwise. The intended use of this attribute is in conjunction with generic definitions. If the attribute is applied to a generic private type, it indicates whether or not the corresponding actual type has discriminants. -@node Attribute Img -@unnumberedsec Attribute Img -@findex Img -@noindent -The @code{Img} attribute differs from @code{Image} in that it is applied +@node Attribute Img,Attribute Integer_Value,Attribute Has_Discriminants,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-img}@anchor{132} +@section Attribute Img + + +@geindex Img + +The @cite{Img} attribute differs from @cite{Image} in that it is applied directly to an object, and yields the same result as -@code{Image} for the subtype of the object. This is convenient for +@cite{Image} for the subtype of the object. This is convenient for debugging: -@smallexample @c ada +@example Put_Line ("X = " & X'Img); -@end smallexample +@end example -@noindent has the same meaning as the more verbose: -@smallexample @c ada -Put_Line ("X = " & @var{T}'Image (X)); -@end smallexample +@example +Put_Line ("X = " & T'Image (X)); +@end example -@noindent -where @var{T} is the (sub)type of the object @code{X}. +where @cite{T} is the (sub)type of the object @cite{X}. -Note that technically, in analogy to @code{Image}, -@code{X'Img} returns a parameterless function +Note that technically, in analogy to @cite{Image}, +@cite{X'Img} returns a parameterless function that returns the appropriate string when called. This means that -@code{X'Img} can be renamed as a function-returning-string, or used +@cite{X'Img} can be renamed as a function-returning-string, or used in an instantiation as a function parameter. -@node Attribute Integer_Value -@unnumberedsec Attribute Integer_Value -@findex Integer_Value -@noindent -For every integer type @var{S}, @code{@var{S}'Integer_Value} denotes a +@node Attribute Integer_Value,Attribute Invalid_Value,Attribute Img,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-integer-value}@anchor{133} +@section Attribute Integer_Value + + +@geindex Integer_Value + +For every integer type @cite{S}, @code{S'Integer_Value} denotes a function with the following spec: -@smallexample @c ada -function @var{S}'Integer_Value (Arg : @i{Universal_Fixed}) - return @var{S}; -@end smallexample +@example +function S'Integer_Value (Arg : <Universal_Fixed>) return S; +@end example -@noindent -The value returned is the integer value @var{V}, such that +The value returned is the integer value @cite{V}, such that: -@smallexample @c ada -Arg = @var{V} * @var{T}'Small -@end smallexample +@example +Arg = V * T'Small +@end example -@noindent -where @var{T} is the type of @code{Arg}. +where @cite{T} is the type of @cite{Arg}. The effect is thus similar to first doing an unchecked conversion from the fixed-point type to its corresponding implementation type, and then converting the result to the target integer type. The difference is @@ -9215,10 +9720,13 @@ that there are full range checks, to ensure that the result is in range. This attribute is primarily intended for use in implementation of the standard input-output functions for fixed-point values. -@node Attribute Invalid_Value -@unnumberedsec Attribute Invalid_Value -@findex Invalid_Value -@noindent +@node Attribute Invalid_Value,Attribute Iterable,Attribute Integer_Value,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-invalid-value}@anchor{134} +@section Attribute Invalid_Value + + +@geindex Invalid_Value + For every scalar type S, S'Invalid_Value returns an undefined value of the type. If possible this value is an invalid representation for the type. The value returned is identical to the value used to initialize an otherwise @@ -9226,27 +9734,36 @@ uninitialized value of the type if pragma Initialize_Scalars is used, including the ability to modify the value with the binder -Sxx flag and relevant environment variables at run time. -@node Attribute Iterable -@unnumberedsec Attribute Iterable -@findex Iterable -@noindent +@node Attribute Iterable,Attribute Large,Attribute Invalid_Value,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-iterable}@anchor{135} +@section Attribute Iterable + + +@geindex Iterable + Equivalent to Aspect Iterable. -@node Attribute Large -@unnumberedsec Attribute Large -@cindex Ada 83 attributes -@findex Large -@noindent -The @code{Large} attribute is provided for compatibility with Ada 83. See +@node Attribute Large,Attribute Library_Level,Attribute Iterable,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-large}@anchor{136} +@section Attribute Large + + +@geindex Ada 83 attributes + +@geindex Large + +The @cite{Large} attribute is provided for compatibility with Ada 83. See the Ada 83 reference manual for an exact description of the semantics of this attribute. -@node Attribute Library_Level -@unnumberedsec Attribute Library_Level -@findex Library_Level -@noindent -@noindent -@code{P'Library_Level}, where P is an entity name, +@node Attribute Library_Level,Attribute Lock_Free,Attribute Large,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-library-level}@anchor{137} +@section Attribute Library_Level + + +@geindex Library_Level + +@cite{P'Library_Level}, where P is an entity name, returns a Boolean value which is True if the entity is declared at the library level, and False otherwise. Note that within a generic instantition, the name of the generic unit denotes the @@ -9254,7 +9771,7 @@ instance, which means that this attribute can be used to test if a generic is instantiated at the library level, as shown in this example: -@smallexample @c ada +@example generic ... package Gen is @@ -9263,98 +9780,130 @@ package Gen is "Gen can only be instantiated at library level"); ... end Gen; -@end smallexample - -@node Attribute Lock_Free -@unnumberedsec Attribute Lock_Free -@findex Lock_Free -@noindent -@code{P'Lock_Free}, where P is a protected object, returns True if a -pragma @code{Lock_Free} applies to P. - -@node Attribute Loop_Entry -@unnumberedsec Attribute Loop_Entry -@findex Loop_Entry -@noindent +@end example + +@node Attribute Lock_Free,Attribute Loop_Entry,Attribute Library_Level,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-lock-free}@anchor{138} +@section Attribute Lock_Free + + +@geindex Lock_Free + +@cite{P'Lock_Free}, where P is a protected object, returns True if a +pragma @cite{Lock_Free} applies to P. + +@node Attribute Loop_Entry,Attribute Machine_Size,Attribute Lock_Free,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-loop-entry}@anchor{139} +@section Attribute Loop_Entry + + +@geindex Loop_Entry + Syntax: -@smallexample @c ada +@example X'Loop_Entry [(loop_name)] -@end smallexample +@end example -@noindent -The @code{Loop_Entry} attribute is used to refer to the value that an +The @cite{Loop_Entry} attribute is used to refer to the value that an expression had upon entry to a given loop in much the same way that the -@code{Old} attribute in a subprogram postcondition can be used to refer +@cite{Old} attribute in a subprogram postcondition can be used to refer to the value an expression had upon entry to the subprogram. The relevant loop is either identified by the given loop name, or it is the innermost enclosing loop when no loop name is given. -@noindent -A @code{Loop_Entry} attribute can only occur within a -@code{Loop_Variant} or @code{Loop_Invariant} pragma. A common use of -@code{Loop_Entry} is to compare the current value of objects with their -initial value at loop entry, in a @code{Loop_Invariant} pragma. +A @cite{Loop_Entry} attribute can only occur within a +@cite{Loop_Variant} or @cite{Loop_Invariant} pragma. A common use of +@cite{Loop_Entry} is to compare the current value of objects with their +initial value at loop entry, in a @cite{Loop_Invariant} pragma. -@noindent -The effect of using @code{X'Loop_Entry} is the same as declaring -a constant initialized with the initial value of @code{X} at loop +The effect of using @cite{X'Loop_Entry} is the same as declaring +a constant initialized with the initial value of @cite{X} at loop entry. This copy is not performed if the loop is not entered, or if the corresponding pragmas are ignored or disabled. -@node Attribute Machine_Size -@unnumberedsec Attribute Machine_Size -@findex Machine_Size -@noindent -This attribute is identical to the @code{Object_Size} attribute. It is +@node Attribute Machine_Size,Attribute Mantissa,Attribute Loop_Entry,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-machine-size}@anchor{13a} +@section Attribute Machine_Size + + +@geindex Machine_Size + +This attribute is identical to the @cite{Object_Size} attribute. It is provided for compatibility with the DEC Ada 83 attribute of this name. -@node Attribute Mantissa -@unnumberedsec Attribute Mantissa -@cindex Ada 83 attributes -@findex Mantissa -@noindent -The @code{Mantissa} attribute is provided for compatibility with Ada 83. See +@node Attribute Mantissa,Attribute Maximum_Alignment,Attribute Machine_Size,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-mantissa}@anchor{13b} +@section Attribute Mantissa + + +@geindex Ada 83 attributes + +@geindex Mantissa + +The @cite{Mantissa} attribute is provided for compatibility with Ada 83. See the Ada 83 reference manual for an exact description of the semantics of this attribute. -@node Attribute Maximum_Alignment -@unnumberedsec Attribute Maximum_Alignment -@cindex Alignment, maximum -@findex Maximum_Alignment -@noindent -@code{Standard'Maximum_Alignment} (@code{Standard} is the only +@node Attribute Maximum_Alignment,Attribute Mechanism_Code,Attribute Mantissa,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-maximum-alignment}@anchor{13c}@anchor{gnat_rm/implementation_defined_attributes id2}@anchor{13d} +@section Attribute Maximum_Alignment + + +@geindex Alignment +@geindex maximum + +@geindex Maximum_Alignment + +@cite{Standard'Maximum_Alignment} (@cite{Standard} is the only permissible prefix) provides the maximum useful alignment value for the target. This is a static value that can be used to specify the alignment for an object, guaranteeing that it is properly aligned in all cases. -@node Attribute Mechanism_Code -@unnumberedsec Attribute Mechanism_Code -@cindex Return values, passing mechanism -@cindex Parameters, passing mechanism -@findex Mechanism_Code -@noindent -@code{@var{function}'Mechanism_Code} yields an integer code for the +@node Attribute Mechanism_Code,Attribute Null_Parameter,Attribute Maximum_Alignment,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-mechanism-code}@anchor{13e} +@section Attribute Mechanism_Code + + +@geindex Return values +@geindex passing mechanism + +@geindex Parameters +@geindex passing mechanism + +@geindex Mechanism_Code + +@code{function'Mechanism_Code} yields an integer code for the mechanism used for the result of function, and -@code{@var{subprogram}'Mechanism_Code (@var{n})} yields the mechanism -used for formal parameter number @var{n} (a static integer value with 1 -meaning the first parameter) of @var{subprogram}. The code returned is: +@code{subprogram'Mechanism_Code (n)} yields the mechanism +used for formal parameter number @cite{n} (a static integer value with 1 +meaning the first parameter) of @cite{subprogram}. The code returned is: + @table @asis -@item 1 + +@item @emph{1} + by copy (value) -@item 2 + +@item @emph{2} + by reference @end table -@node Attribute Null_Parameter -@unnumberedsec Attribute Null_Parameter -@cindex Zero address, passing -@findex Null_Parameter -@noindent -A reference @code{@var{T}'Null_Parameter} denotes an imaginary object of -type or subtype @var{T} allocated at machine address zero. The attribute +@node Attribute Null_Parameter,Attribute Object_Size,Attribute Mechanism_Code,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-null-parameter}@anchor{13f} +@section Attribute Null_Parameter + + +@geindex Zero address +@geindex passing + +@geindex Null_Parameter + +A reference @code{T'Null_Parameter} denotes an imaginary object of +type or subtype @cite{T} allocated at machine address zero. The attribute is allowed only as the default expression of a formal parameter, or as an actual expression of a subprogram call. In either case, the subprogram must be imported. @@ -9365,30 +9914,34 @@ default). This capability is needed to specify that a zero address should be passed for a record or other composite object passed by reference. -There is no way of indicating this without the @code{Null_Parameter} +There is no way of indicating this without the @cite{Null_Parameter} attribute. -@node Attribute Object_Size -@unnumberedsec Attribute Object_Size -@cindex Size, used for objects -@findex Object_Size -@noindent +@node Attribute Object_Size,Attribute Old,Attribute Null_Parameter,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-object-size}@anchor{140} +@section Attribute Object_Size + + +@geindex Size +@geindex used for objects + +@geindex Object_Size + The size of an object is not necessarily the same as the size of the type of an object. This is because by default object sizes are increased to be a multiple of the alignment of the object. For example, -@code{Natural'Size} is -31, but by default objects of type @code{Natural} will have a size of 32 bits. +@cite{Natural'Size} is +31, but by default objects of type @cite{Natural} will have a size of 32 bits. Similarly, a record containing an integer and a character: -@smallexample @c ada +@example type Rec is record I : Integer; C : Character; end record; -@end smallexample +@end example -@noindent -will have a size of 40 (that is @code{Rec'Size} will be 40). The +will have a size of 40 (that is @cite{Rec'Size} will be 40). The alignment will be 4, because of the integer field, and so the default size of record objects for this type will be 64 (8 bytes). @@ -9400,11 +9953,11 @@ an object size of 40 can be explicitly specified in this case. A consequence of this capability is that different object sizes can be given to subtypes that would otherwise be considered in Ada to be statically matching. But it makes no sense to consider such subtypes -as statically matching. Consequently, in @code{GNAT} we add a rule +as statically matching. Consequently, in @cite{GNAT} we add a rule to the static matching rules that requires object sizes to match. Consider this example: -@smallexample @c ada +@example 1. procedure BadAVConvert is 2. type R is new Integer; 3. subtype R1 is R range 1 .. 10; @@ -9422,83 +9975,103 @@ Consider this example: type "R1" defined at line 3 13. end; -@end smallexample +@end example -@noindent In the absence of lines 5 and 6, -types @code{R1} and @code{R2} statically match and +types @cite{R1} and @cite{R2} statically match and hence the conversion on line 12 is legal. But since lines 5 and 6 -cause the object sizes to differ, @code{GNAT} considers that types -@code{R1} and @code{R2} are not statically matching, and line 12 +cause the object sizes to differ, @cite{GNAT} considers that types +@cite{R1} and @cite{R2} are not statically matching, and line 12 generates the diagnostic shown above. -@noindent Similar additional checks are performed in other contexts requiring statically matching subtypes. -@node Attribute Old -@unnumberedsec Attribute Old -@findex Old -@noindent -In addition to the usage of @code{Old} defined in the Ada 2012 RM (usage -within @code{Post} aspect), GNAT also permits the use of this attribute -in implementation defined pragmas @code{Postcondition}, -@code{Contract_Cases} and @code{Test_Case}. Also usages of -@code{Old} which would be illegal according to the Ada 2012 RM +@node Attribute Old,Attribute Passed_By_Reference,Attribute Object_Size,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-old}@anchor{141} +@section Attribute Old + + +@geindex Old + +In addition to the usage of @cite{Old} defined in the Ada 2012 RM (usage +within @cite{Post} aspect), GNAT also permits the use of this attribute +in implementation defined pragmas @cite{Postcondition}, +@cite{Contract_Cases} and @cite{Test_Case}. Also usages of +@cite{Old} which would be illegal according to the Ada 2012 RM definition are allowed under control of -implementation defined pragma @code{Unevaluated_Use_Of_Old}. - -@node Attribute Passed_By_Reference -@unnumberedsec Attribute Passed_By_Reference -@cindex Parameters, when passed by reference -@findex Passed_By_Reference -@noindent -@code{@var{type}'Passed_By_Reference} for any subtype @var{type} returns -a value of type @code{Boolean} value that is @code{True} if the type is -normally passed by reference and @code{False} if the type is normally -passed by copy in calls. For scalar types, the result is always @code{False} +implementation defined pragma @cite{Unevaluated_Use_Of_Old}. + +@node Attribute Passed_By_Reference,Attribute Pool_Address,Attribute Old,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-passed-by-reference}@anchor{142} +@section Attribute Passed_By_Reference + + +@geindex Parameters +@geindex when passed by reference + +@geindex Passed_By_Reference + +@code{type'Passed_By_Reference} for any subtype @cite{type} returns +a value of type @cite{Boolean} value that is @cite{True} if the type is +normally passed by reference and @cite{False} if the type is normally +passed by copy in calls. For scalar types, the result is always @cite{False} and is static. For non-scalar types, the result is non-static. -@node Attribute Pool_Address -@unnumberedsec Attribute Pool_Address -@cindex Parameters, when passed by reference -@findex Pool_Address -@noindent -@code{@var{X}'Pool_Address} for any object @var{X} returns the address +@node Attribute Pool_Address,Attribute Range_Length,Attribute Passed_By_Reference,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-pool-address}@anchor{143} +@section Attribute Pool_Address + + +@geindex Parameters +@geindex when passed by reference + +@geindex Pool_Address + +@code{X'Pool_Address} for any object @cite{X} returns the address of X within its storage pool. This is the same as -@code{@var{X}'Address}, except that for an unconstrained array whose +@code{X'Address}, except that for an unconstrained array whose bounds are allocated just before the first component, -@code{@var{X}'Pool_Address} returns the address of those bounds, -whereas @code{@var{X}'Address} returns the address of the first +@code{X'Pool_Address} returns the address of those bounds, +whereas @code{X'Address} returns the address of the first component. -Here, we are interpreting ``storage pool'' broadly to mean ``wherever -the object is allocated'', which could be a user-defined storage pool, -the global heap, on the stack, or in a static memory area. For an -object created by @code{new}, @code{@var{Ptr.all}'Pool_Address} is -what is passed to @code{Allocate} and returned from @code{Deallocate}. - -@node Attribute Range_Length -@unnumberedsec Attribute Range_Length -@findex Range_Length -@noindent -@code{@var{type}'Range_Length} for any discrete type @var{type} yields +Here, we are interpreting 'storage pool' broadly to mean +@code{wherever the object is allocated}, which could be a +user-defined storage pool, +the global heap, on the stack, or in a static memory area. +For an object created by @cite{new}, @code{Ptr.all'Pool_Address} is +what is passed to @cite{Allocate} and returned from @cite{Deallocate}. + +@node Attribute Range_Length,Attribute Ref,Attribute Pool_Address,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-range-length}@anchor{144} +@section Attribute Range_Length + + +@geindex Range_Length + +@code{type'Range_Length} for any discrete type @cite{type} yields the number of values represented by the subtype (zero for a null -range). The result is static for static subtypes. @code{Range_Length} +range). The result is static for static subtypes. @cite{Range_Length} applied to the index subtype of a one dimensional array always gives the -same result as @code{Length} applied to the array itself. +same result as @cite{Length} applied to the array itself. -@node Attribute Ref -@unnumberedsec Attribute Ref -@findex Ref -@noindent +@node Attribute Ref,Attribute Restriction_Set,Attribute Range_Length,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-ref}@anchor{145} +@section Attribute Ref -@node Attribute Restriction_Set -@unnumberedsec Attribute Restriction_Set -@findex Restriction_Set -@cindex Restrictions -@noindent +@geindex Ref + +@node Attribute Restriction_Set,Attribute Result,Attribute Ref,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-restriction-set}@anchor{146} +@section Attribute Restriction_Set + + +@geindex Restriction_Set + +@geindex Restrictions + This attribute allows compile time testing of restrictions that are currently in effect. It is primarily intended for specializing code in the run-time based on restrictions that are active (e.g. @@ -9507,16 +10080,15 @@ is known to be in effect), but can be used anywhere. There are two forms: -@smallexample @c ada +@example System'Restriction_Set (partition_boolean_restriction_NAME) System'Restriction_Set (No_Dependence => library_unit_NAME); -@end smallexample +@end example -@noindent In the case of the first form, the only restriction names allowed are parameterless restrictions that are checked for consistency at bind time. For a complete list see the -subtype @code{System.Rident.Partition_Boolean_Restrictions}. +subtype @cite{System.Rident.Partition_Boolean_Restrictions}. The result returned is True if the restriction is known to be in effect, and False if the restriction is known not to @@ -9540,15 +10112,14 @@ restriction. So for example if you write -@smallexample @c ada +@example if System'Restriction_Set (No_Floating_Point) then ... else ... end if; -@end smallexample +@end example -@noindent And the result is False, so that the else branch is executed, you can assume that this restriction is not set for any unit in the partition. This is checked by considering this use of @@ -9562,95 +10133,114 @@ intepreted entirely syntactically, as in the corresponding Restrictions pragma, they are not analyzed semantically, so they do not have a type. -@node Attribute Result -@unnumberedsec Attribute Result -@findex Result -@noindent -@code{@var{function}'Result} can only be used with in a Postcondition pragma +@node Attribute Result,Attribute Safe_Emax,Attribute Restriction_Set,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-result}@anchor{147} +@section Attribute Result + + +@geindex Result + +@code{function'Result} can only be used with in a Postcondition pragma for a function. The prefix must be the name of the corresponding function. This is used to refer to the result of the function in the postcondition expression. For a further discussion of the use of this attribute and examples of its use, see the description of pragma Postcondition. -@node Attribute Safe_Emax -@unnumberedsec Attribute Safe_Emax -@cindex Ada 83 attributes -@findex Safe_Emax -@noindent -The @code{Safe_Emax} attribute is provided for compatibility with Ada 83. See +@node Attribute Safe_Emax,Attribute Safe_Large,Attribute Result,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-safe-emax}@anchor{148} +@section Attribute Safe_Emax + + +@geindex Ada 83 attributes + +@geindex Safe_Emax + +The @cite{Safe_Emax} attribute is provided for compatibility with Ada 83. See the Ada 83 reference manual for an exact description of the semantics of this attribute. -@node Attribute Safe_Large -@unnumberedsec Attribute Safe_Large -@cindex Ada 83 attributes -@findex Safe_Large -@noindent -The @code{Safe_Large} attribute is provided for compatibility with Ada 83. See +@node Attribute Safe_Large,Attribute Safe_Small,Attribute Safe_Emax,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-safe-large}@anchor{149} +@section Attribute Safe_Large + + +@geindex Ada 83 attributes + +@geindex Safe_Large + +The @cite{Safe_Large} attribute is provided for compatibility with Ada 83. See the Ada 83 reference manual for an exact description of the semantics of this attribute. -@node Attribute Safe_Small -@unnumberedsec Attribute Safe_Small -@cindex Ada 83 attributes -@findex Safe_Small -@noindent -The @code{Safe_Small} attribute is provided for compatibility with Ada 83. See +@node Attribute Safe_Small,Attribute Scalar_Storage_Order,Attribute Safe_Large,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-safe-small}@anchor{14a} +@section Attribute Safe_Small + + +@geindex Ada 83 attributes + +@geindex Safe_Small + +The @cite{Safe_Small} attribute is provided for compatibility with Ada 83. See the Ada 83 reference manual for an exact description of the semantics of this attribute. -@node Attribute Scalar_Storage_Order -@unnumberedsec Attribute Scalar_Storage_Order -@cindex Endianness -@cindex Scalar storage order -@findex Scalar_Storage_Order -@noindent -For every array or record type @var{S}, the representation attribute -@code{Scalar_Storage_Order} denotes the order in which storage elements +@node Attribute Scalar_Storage_Order,Attribute Simple_Storage_Pool,Attribute Safe_Small,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-scalar-storage-order}@anchor{14b} +@section Attribute Scalar_Storage_Order + + +@geindex Endianness + +@geindex Scalar storage order + +@geindex Scalar_Storage_Order + +For every array or record type @cite{S}, the representation attribute +@cite{Scalar_Storage_Order} denotes the order in which storage elements that make up scalar components are ordered within S. The value given must be a static expression of type System.Bit_Order. The following is an example of the use of this feature: -@smallexample @c ada - -- Component type definitions +@example +-- Component type definitions - subtype Yr_Type is Natural range 0 .. 127; - subtype Mo_Type is Natural range 1 .. 12; - subtype Da_Type is Natural range 1 .. 31; +subtype Yr_Type is Natural range 0 .. 127; +subtype Mo_Type is Natural range 1 .. 12; +subtype Da_Type is Natural range 1 .. 31; - -- Record declaration +-- Record declaration - type Date is record - Years_Since_1980 : Yr_Type; - Month : Mo_Type; - Day_Of_Month : Da_Type; - end record; +type Date is record + Years_Since_1980 : Yr_Type; + Month : Mo_Type; + Day_Of_Month : Da_Type; +end record; - -- Record representation clause +-- Record representation clause - for Date use record - Years_Since_1980 at 0 range 0 .. 6; - Month at 0 range 7 .. 10; - Day_Of_Month at 0 range 11 .. 15; - end record; +for Date use record + Years_Since_1980 at 0 range 0 .. 6; + Month at 0 range 7 .. 10; + Day_Of_Month at 0 range 11 .. 15; +end record; - -- Attribute definition clauses +-- Attribute definition clauses - for Date'Bit_Order use System.High_Order_First; - for Date'Scalar_Storage_Order use System.High_Order_First; - -- If Scalar_Storage_Order is specified, it must be consistent with - -- Bit_Order, so it's best to always define the latter explicitly if - -- the former is used. -@end smallexample +for Date'Bit_Order use System.High_Order_First; +for Date'Scalar_Storage_Order use System.High_Order_First; +-- If Scalar_Storage_Order is specified, it must be consistent with +-- Bit_Order, so it's best to always define the latter explicitly if +-- the former is used. +@end example -@noindent -Other properties are as for standard representation attribute @code{Bit_Order}, -as defined by Ada RM 13.5.3(4). The default is @code{System.Default_Bit_Order}. +Other properties are as for standard representation attribute @cite{Bit_Order}, +as defined by Ada RM 13.5.3(4). The default is @cite{System.Default_Bit_Order}. -For a record type @var{T}, if @code{@var{T}'Scalar_Storage_Order} is -specified explicitly, it shall be equal to @code{@var{T}'Bit_Order}. Note: -this means that if a @code{Scalar_Storage_Order} attribute definition -clause is not confirming, then the type's @code{Bit_Order} shall be +For a record type @cite{T}, if @code{T'Scalar_Storage_Order} is +specified explicitly, it shall be equal to @code{T'Bit_Order}. Note: +this means that if a @cite{Scalar_Storage_Order} attribute definition +clause is not confirming, then the type's @cite{Bit_Order} shall be specified explicitly and set to the same value. Derived types inherit an explicitly set scalar storage order from their parent @@ -9658,21 +10248,21 @@ types. This may be overridden for the derived type by giving an explicit scalar storage order for the derived type. For a record extension, the derived type must have the same scalar storage order as the parent type. -If a component of @var{T} is of a record or array type, then that type must -also have a @code{Scalar_Storage_Order} attribute definition clause. +If a component of @cite{T} is of a record or array type, then that type must +also have a @cite{Scalar_Storage_Order} attribute definition clause. A component of a record or array type that is a packed array, or that does not start on a byte boundary, must have the same scalar storage order as the enclosing record or array type. -No component of a type that has an explicit @code{Scalar_Storage_Order} +No component of a type that has an explicit @cite{Scalar_Storage_Order} attribute definition may be aliased. -A confirming @code{Scalar_Storage_Order} attribute definition clause (i.e. -with a value equal to @code{System.Default_Bit_Order}) has no effect. +A confirming @cite{Scalar_Storage_Order} attribute definition clause (i.e. +with a value equal to @cite{System.Default_Bit_Order}) has no effect. If the opposite storage order is specified, then whenever the value of -a scalar component of an object of type @var{S} is read, the storage +a scalar component of an object of type @cite{S} is read, the storage elements of the enclosing machine scalar are first reversed (before retrieving the component value, possibly applying some shift and mask operatings on the enclosing machine scalar), and the opposite operation @@ -9681,111 +10271,133 @@ is done for writes. In that case, the restrictions set forth in 13.5.1(10.3/2) for scalar components are relaxed. Instead, the following rules apply: -@itemize @bullet -@item the underlying storage elements are those at positions - @code{(position + first_bit / storage_element_size) .. - (position + (last_bit + storage_element_size - 1) / - storage_element_size)} -@item the sequence of underlying storage elements shall have - a size no greater than the largest machine scalar -@item the enclosing machine scalar is defined as the smallest machine - scalar starting at a position no greater than - @code{position + first_bit / storage_element_size} and covering - storage elements at least up to @code{position + (last_bit + - storage_element_size - 1) / storage_element_size} -@item the position of the component is interpreted relative to that machine - scalar. +@itemize * + +@item +the underlying storage elements are those at positions +@cite{(position + first_bit / storage_element_size) .. (position + (last_bit + storage_element_size - 1) / storage_element_size)} + +@item +the sequence of underlying storage elements shall have +a size no greater than the largest machine scalar + +@item +the enclosing machine scalar is defined as the smallest machine +scalar starting at a position no greater than +@cite{position + first_bit / storage_element_size} and covering +storage elements at least up to @cite{position + (last_bit + storage_element_size - 1) / storage_element_size} + +@item +the position of the component is interpreted relative to that machine +scalar. @end itemize If no scalar storage order is specified for a type (either directly, or by inheritance in the case of a derived type), then the default is normally the native ordering of the target, but this default can be overridden using -pragma @code{Default_Scalar_Storage_Order}. - -@node Attribute Simple_Storage_Pool -@unnumberedsec Attribute Simple_Storage_Pool -@cindex Storage pool, simple -@cindex Simple storage pool -@findex Simple_Storage_Pool -@noindent -For every nonformal, nonderived access-to-object type @var{Acc}, the -representation attribute @code{Simple_Storage_Pool} may be specified -via an attribute_definition_clause (or by specifying the equivalent aspect): +pragma @cite{Default_Scalar_Storage_Order}. + +Note that the scalar storage order only affects the in-memory data +representation. It has no effect on the representation used by stream +attributes. + +@node Attribute Simple_Storage_Pool,Attribute Small,Attribute Scalar_Storage_Order,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-simple-storage-pool}@anchor{b6}@anchor{gnat_rm/implementation_defined_attributes id3}@anchor{14c} +@section Attribute Simple_Storage_Pool + + +@geindex Storage pool +@geindex simple + +@geindex Simple storage pool -@smallexample @c ada +@geindex Simple_Storage_Pool +For every nonformal, nonderived access-to-object type @cite{Acc}, the +representation attribute @cite{Simple_Storage_Pool} may be specified +via an attribute_definition_clause (or by specifying the equivalent aspect): + +@example My_Pool : My_Simple_Storage_Pool_Type; type Acc is access My_Data_Type; for Acc'Simple_Storage_Pool use My_Pool; +@end example -@end smallexample - -@noindent The name given in an attribute_definition_clause for the -@code{Simple_Storage_Pool} attribute shall denote a variable of -a ``simple storage pool type'' (see pragma @code{Simple_Storage_Pool_Type}). +@cite{Simple_Storage_Pool} attribute shall denote a variable of +a 'simple storage pool type' (see pragma @cite{Simple_Storage_Pool_Type}). The use of this attribute is only allowed for a prefix denoting a type for which it has been specified. The type of the attribute is the type of the variable specified as the simple storage pool of the access type, and the attribute denotes that variable. -It is illegal to specify both @code{Storage_Pool} and @code{Simple_Storage_Pool} +It is illegal to specify both @cite{Storage_Pool} and @cite{Simple_Storage_Pool} for the same access type. -If the @code{Simple_Storage_Pool} attribute has been specified for an access -type, then applying the @code{Storage_Pool} attribute to the type is flagged -with a warning and its evaluation raises the exception @code{Program_Error}. +If the @cite{Simple_Storage_Pool} attribute has been specified for an access +type, then applying the @cite{Storage_Pool} attribute to the type is flagged +with a warning and its evaluation raises the exception @cite{Program_Error}. If the Simple_Storage_Pool attribute has been specified for an access -type @var{S}, then the evaluation of the attribute @code{@var{S}'Storage_Size} -returns the result of calling @code{Storage_Size (@var{S}'Simple_Storage_Pool)}, +type @cite{S}, then the evaluation of the attribute @code{S'Storage_Size} +returns the result of calling @code{Storage_Size (S'Simple_Storage_Pool)}, which is intended to indicate the number of storage elements reserved for the simple storage pool. If the Storage_Size function has not been defined for the simple storage pool type, then this attribute returns zero. -If an access type @var{S} has a specified simple storage pool of type -@var{SSP}, then the evaluation of an allocator for that access type calls -the primitive @code{Allocate} procedure for type @var{SSP}, passing -@code{@var{S}'Simple_Storage_Pool} as the pool parameter. The detailed +If an access type @cite{S} has a specified simple storage pool of type +@cite{SSP}, then the evaluation of an allocator for that access type calls +the primitive @cite{Allocate} procedure for type @cite{SSP}, passing +@code{S'Simple_Storage_Pool} as the pool parameter. The detailed semantics of such allocators is the same as those defined for allocators -in section 13.11 of the Ada Reference Manual, with the term -``simple storage pool'' substituted for ``storage pool''. +in section 13.11 of the @cite{Ada Reference Manual}, with the term +@cite{simple storage pool} substituted for @cite{storage pool}. -If an access type @var{S} has a specified simple storage pool of type -@var{SSP}, then a call to an instance of the @code{Ada.Unchecked_Deallocation} -for that access type invokes the primitive @code{Deallocate} procedure -for type @var{SSP}, passing @code{@var{S}'Simple_Storage_Pool} as the pool +If an access type @cite{S} has a specified simple storage pool of type +@cite{SSP}, then a call to an instance of the @cite{Ada.Unchecked_Deallocation} +for that access type invokes the primitive @cite{Deallocate} procedure +for type @cite{SSP}, passing @code{S'Simple_Storage_Pool} as the pool parameter. The detailed semantics of such unchecked deallocations is the same as defined in section 13.11.2 of the Ada Reference Manual, except that the -term ``simple storage pool'' is substituted for ``storage pool''. - -@node Attribute Small -@unnumberedsec Attribute Small -@cindex Ada 83 attributes -@findex Small -@noindent -The @code{Small} attribute is defined in Ada 95 (and Ada 2005) only for +term 'simple storage pool' is substituted for 'storage pool'. + +@node Attribute Small,Attribute Storage_Unit,Attribute Simple_Storage_Pool,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-small}@anchor{14d} +@section Attribute Small + + +@geindex Ada 83 attributes + +@geindex Small + +The @cite{Small} attribute is defined in Ada 95 (and Ada 2005) only for fixed-point types. GNAT also allows this attribute to be applied to floating-point types for compatibility with Ada 83. See the Ada 83 reference manual for an exact description of the semantics of this attribute when applied to floating-point types. -@node Attribute Storage_Unit -@unnumberedsec Attribute Storage_Unit -@findex Storage_Unit -@noindent -@code{Standard'Storage_Unit} (@code{Standard} is the only permissible -prefix) provides the same value as @code{System.Storage_Unit}. - -@node Attribute Stub_Type -@unnumberedsec Attribute Stub_Type -@findex Stub_Type -@noindent +@node Attribute Storage_Unit,Attribute Stub_Type,Attribute Small,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-storage-unit}@anchor{14e} +@section Attribute Storage_Unit + + +@geindex Storage_Unit + +@cite{Standard'Storage_Unit} (@cite{Standard} is the only permissible +prefix) provides the same value as @cite{System.Storage_Unit}. + +@node Attribute Stub_Type,Attribute System_Allocator_Alignment,Attribute Storage_Unit,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-stub-type}@anchor{14f} +@section Attribute Stub_Type + + +@geindex Stub_Type + The GNAT implementation of remote access-to-classwide types is organized as described in AARM section E.4 (20.t): a value of an RACW type (designating a remote object) is represented as a normal access @@ -9795,74 +10407,91 @@ call on any dispatching operation of such a stub object does the remote call, if necessary, using the information in the stub object to locate the target partition, etc. -For a prefix @code{T} that denotes a remote access-to-classwide type, -@code{T'Stub_Type} denotes the type of the corresponding stub objects. +For a prefix @cite{T} that denotes a remote access-to-classwide type, +@cite{T'Stub_Type} denotes the type of the corresponding stub objects. -By construction, the layout of @code{T'Stub_Type} is identical to that of -type @code{RACW_Stub_Type} declared in the internal implementation-defined -unit @code{System.Partition_Interface}. Use of this attribute will create +By construction, the layout of @cite{T'Stub_Type} is identical to that of +type @cite{RACW_Stub_Type} declared in the internal implementation-defined +unit @cite{System.Partition_Interface}. Use of this attribute will create an implicit dependency on this unit. -@node Attribute System_Allocator_Alignment -@unnumberedsec Attribute System_Allocator_Alignment -@cindex Alignment, allocator -@findex System_Allocator_Alignment -@noindent -@code{Standard'System_Allocator_Alignment} (@code{Standard} is the only +@node Attribute System_Allocator_Alignment,Attribute Target_Name,Attribute Stub_Type,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-system-allocator-alignment}@anchor{150} +@section Attribute System_Allocator_Alignment + + +@geindex Alignment +@geindex allocator + +@geindex System_Allocator_Alignment + +@cite{Standard'System_Allocator_Alignment} (@cite{Standard} is the only permissible prefix) provides the observable guaranted to be honored by the system allocator (malloc). This is a static value that can be used in user storage pools based on malloc either to reject allocation with alignment too large or to enable a realignment circuitry if the alignment request is larger than this value. -@node Attribute Target_Name -@unnumberedsec Attribute Target_Name -@findex Target_Name -@noindent -@code{Standard'Target_Name} (@code{Standard} is the only permissible +@node Attribute Target_Name,Attribute To_Address,Attribute System_Allocator_Alignment,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-target-name}@anchor{151} +@section Attribute Target_Name + + +@geindex Target_Name + +@cite{Standard'Target_Name} (@cite{Standard} is the only permissible prefix) provides a static string value that identifies the target for the current compilation. For GCC implementations, this is the standard gcc target name without the terminating slash (for example, GNAT 5.0 on windows yields "i586-pc-mingw32msv"). -@node Attribute To_Address -@unnumberedsec Attribute To_Address -@findex To_Address -@noindent -The @code{System'To_Address} -(@code{System} is the only permissible prefix) +@node Attribute To_Address,Attribute To_Any,Attribute Target_Name,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-to-address}@anchor{152} +@section Attribute To_Address + + +@geindex To_Address + +The @cite{System'To_Address} +(@cite{System} is the only permissible prefix) denotes a function identical to -@code{System.Storage_Elements.To_Address} except that +@cite{System.Storage_Elements.To_Address} except that it is a static attribute. This means that if its argument is a static expression, then the result of the attribute is a static expression. This means that such an expression can be -used in contexts (e.g.@: preelaborable packages) which require a +used in contexts (e.g., preelaborable packages) which require a static expression and where the function call could not be used (since the function call is always non-static, even if its argument is static). The argument must be in the range -(2**(m-1) .. 2**m-1, where m is the memory size (typically 32 or 64). Negative values are intepreted in a -modular manner (e.g. -1 means the same as 16#FFFF_FFFF# on +modular manner (e.g., -1 means the same as 16#FFFF_FFFF# on a 32 bits machine). -@node Attribute To_Any -@unnumberedsec Attribute To_Any -@findex To_Any -@noindent +@node Attribute To_Any,Attribute Type_Class,Attribute To_Address,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-to-any}@anchor{153} +@section Attribute To_Any + + +@geindex To_Any + This internal attribute is used for the generation of remote subprogram stubs in the context of the Distributed Systems Annex. -@node Attribute Type_Class -@unnumberedsec Attribute Type_Class -@findex Type_Class -@noindent -@code{@var{type}'Type_Class} for any type or subtype @var{type} yields -the value of the type class for the full type of @var{type}. If -@var{type} is a generic formal type, the value is the value for the +@node Attribute Type_Class,Attribute Type_Key,Attribute To_Any,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-type-class}@anchor{154} +@section Attribute Type_Class + + +@geindex Type_Class + +@code{type'Type_Class} for any type or subtype @cite{type} yields +the value of the type class for the full type of @cite{type}. If +@cite{type} is a generic formal type, the value is the value for the corresponding actual subtype. The value of this attribute is of type @code{System.Aux_DEC.Type_Class}, which has the following definition: -@smallexample @c ada +@example type Type_Class is (Type_Class_Enumeration, Type_Class_Integer, @@ -9873,57 +10502,73 @@ type Type_Class is Type_Class_Access, Type_Class_Task, Type_Class_Address); -@end smallexample +@end example -@noindent -Protected types yield the value @code{Type_Class_Task}, which thus +Protected types yield the value @cite{Type_Class_Task}, which thus applies to all concurrent types. This attribute is designed to be compatible with the DEC Ada 83 attribute of the same name. -@node Attribute Type_Key -@unnumberedsec Attribute Type_Key -@findex Type_Key -@noindent -The @code{Type_Key} attribute is applicable to a type or subtype and +@node Attribute Type_Key,Attribute TypeCode,Attribute Type_Class,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-type-key}@anchor{155} +@section Attribute Type_Key + + +@geindex Type_Key + +The @cite{Type_Key} attribute is applicable to a type or subtype and yields a value of type Standard.String containing encoded information about the type or subtype. This provides improved compatibility with other implementations that support this attribute. -@node Attribute TypeCode -@unnumberedsec Attribute TypeCode -@findex TypeCode -@noindent +@node Attribute TypeCode,Attribute UET_Address,Attribute Type_Key,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-typecode}@anchor{156} +@section Attribute TypeCode + + +@geindex TypeCode + This internal attribute is used for the generation of remote subprogram stubs in the context of the Distributed Systems Annex. -@node Attribute UET_Address -@unnumberedsec Attribute UET_Address -@findex UET_Address -@noindent -The @code{UET_Address} attribute can only be used for a prefix which +@node Attribute UET_Address,Attribute Unconstrained_Array,Attribute TypeCode,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-uet-address}@anchor{157} +@section Attribute UET_Address + + +@geindex UET_Address + +The @cite{UET_Address} attribute can only be used for a prefix which denotes a library package. It yields the address of the unit exception table when zero cost exception handling is used. This attribute is intended only for use within the GNAT implementation. See the unit -@code{Ada.Exceptions} in files @file{a-except.ads} and @file{a-except.adb} +@cite{Ada.Exceptions} in files @code{a-except.ads} and @code{a-except.adb} for details on how this attribute is used in the implementation. -@node Attribute Unconstrained_Array -@unnumberedsec Attribute Unconstrained_Array -@findex Unconstrained_Array -@noindent -The @code{Unconstrained_Array} attribute can be used with a prefix that +@node Attribute Unconstrained_Array,Attribute Universal_Literal_String,Attribute UET_Address,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-unconstrained-array}@anchor{158} +@section Attribute Unconstrained_Array + + +@geindex Unconstrained_Array + +The @cite{Unconstrained_Array} attribute can be used with a prefix that denotes any type or subtype. It is a static attribute that yields -@code{True} if the prefix designates an unconstrained array, -and @code{False} otherwise. In a generic instance, the result is +@cite{True} if the prefix designates an unconstrained array, +and @cite{False} otherwise. In a generic instance, the result is still static, and yields the result of applying this test to the generic actual. -@node Attribute Universal_Literal_String -@unnumberedsec Attribute Universal_Literal_String -@cindex Named numbers, representation of -@findex Universal_Literal_String -@noindent -The prefix of @code{Universal_Literal_String} must be a named +@node Attribute Universal_Literal_String,Attribute Unrestricted_Access,Attribute Unconstrained_Array,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-universal-literal-string}@anchor{159} +@section Attribute Universal_Literal_String + + +@geindex Named numbers +@geindex representation of + +@geindex Universal_Literal_String + +The prefix of @cite{Universal_Literal_String} must be a named number. The static result is the string consisting of the characters of the number as defined in the original source. This allows the user program to access the actual text of named numbers without intermediate @@ -9932,38 +10577,43 @@ would preclude their use as numbers). For example, the following program prints the first 50 digits of pi: -@smallexample @c ada +@example with Text_IO; use Text_IO; with Ada.Numerics; procedure Pi is begin Put (Ada.Numerics.Pi'Universal_Literal_String); end; -@end smallexample - -@node Attribute Unrestricted_Access -@unnumberedsec Attribute Unrestricted_Access -@cindex @code{Access}, unrestricted -@findex Unrestricted_Access -@noindent -The @code{Unrestricted_Access} attribute is similar to @code{Access} +@end example + +@node Attribute Unrestricted_Access,Attribute Update,Attribute Universal_Literal_String,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-unrestricted-access}@anchor{15a} +@section Attribute Unrestricted_Access + + +@geindex Access +@geindex unrestricted + +@geindex Unrestricted_Access + +The @cite{Unrestricted_Access} attribute is similar to @cite{Access} except that all accessibility and aliased view checks are omitted. This is a user-beware attribute. -For objects, it is similar to @code{Address}, for which it is a +For objects, it is similar to @cite{Address}, for which it is a desirable replacement where the value desired is an access type. In other words, its effect is similar to first applying the -@code{Address} attribute and then doing an unchecked conversion to a +@cite{Address} attribute and then doing an unchecked conversion to a desired access type. -For subprograms, @code{P'Unrestricted_Access} may be used where -@code{P'Access} would be illegal, to construct a value of a +For subprograms, @cite{P'Unrestricted_Access} may be used where +@cite{P'Access} would be illegal, to construct a value of a less-nested named access type that designates a more-nested subprogram. This value may be used in indirect calls, so long as the more-nested subprogram still exists; once the subprogram containing it has returned, such calls are erroneous. For example: -@smallexample @c ada +@example package body P is type Less_Nested is not null access procedure; @@ -9987,23 +10637,23 @@ package body P is end P2; end P; -@end smallexample +@end example When P1 is called from P2, the call via Global is OK, but if P1 were called after P2 returns, it would be an erroneous use of a dangling pointer. -For objects, it is possible to use @code{Unrestricted_Access} for any +For objects, it is possible to use @cite{Unrestricted_Access} for any type. However, if the result is of an access-to-unconstrained array subtype, then the resulting pointer has the same scope as the context of the attribute, and must not be returned to some enclosing scope. -For instance, if a function uses @code{Unrestricted_Access} to create +For instance, if a function uses @cite{Unrestricted_Access} to create an access-to-unconstrained-array and returns that value to the caller, the result will involve dangling pointers. In addition, it is only valid to create pointers to unconstrained arrays using this attribute -if the pointer has the normal default ``fat'' representation where a +if the pointer has the normal default 'fat' representation where a pointer has two components, one points to the array and one points to -the bounds. If a size clause is used to force ``thin'' representation +the bounds. If a size clause is used to force 'thin' representation for a pointer to unconstrained where there is only space for a single pointer, then the resulting pointer is not usable. @@ -10011,7 +10661,7 @@ In the simple case where a direct use of Unrestricted_Access attempts to make a thin pointer for a non-aliased object, the compiler will reject the use as illegal, as shown in the following example: -@smallexample @c ada +@example with System; use System; procedure SliceUA2 is type A is access all String; @@ -10043,13 +10693,12 @@ begin P (X2'Unrestricted_Access); -- OK end; -@end smallexample +@end example -@noindent but other cases cannot be detected by the compiler, and are considered to be erroneous. Consider the following example: -@smallexample @c ada +@example with System; use System; with System; use System; procedure SliceUA is @@ -10071,23 +10720,22 @@ procedure SliceUA is begin P (A (Y)); end; -@end smallexample +@end example -@noindent A normal unconstrained array value or a constrained array object marked as aliased has the bounds in memory just before the array, so a thin pointer can retrieve both the data and -the bounds. But in this case, the non-aliased object @code{X} does not have the -bounds before the string. If the size clause for type @code{A} +the bounds. But in this case, the non-aliased object @cite{X} does not have the +bounds before the string. If the size clause for type @cite{A} were not present, then the pointer would be a fat pointer, where one component is a pointer to the bounds, and all would be well. But with the size clause present, the conversion from fat pointer to thin pointer in the call loses the bounds, and so this -is erroneous, and the program likely raises a @code{Program_Error} exception. +is erroneous, and the program likely raises a @cite{Program_Error} exception. In general, it is advisable to completely avoid mixing the use of thin pointers and the use of -@code{Unrestricted_Access} where the designated type is an +@cite{Unrestricted_Access} where the designated type is an unconstrained array. The use of thin pointers should be restricted to cases of porting legacy code that implicitly assumes the size of pointers, and such code should not in any case be using this attribute. @@ -10097,44 +10745,45 @@ applied to a constant. The resulting pointer can be used to access the constant, but the effect of trying to modify a constant in this manner is not well-defined. Consider this example: -@smallexample @c ada +@example P : constant Integer := 4; type R is access all Integer; RV : R := P'Unrestricted_Access; .. RV.all := 3; -@end smallexample +@end example -@noindent Here we attempt to modify the constant P from 4 to 3, but the compiler may or may not notice this attempt, and subsequent references to P may yield either the value 3 or the value 4 or the assignment may blow up if the compiler decides to put P in read-only memory. One particular case where -@code{Unrestricted_Access} can be used in this way is to modify the -value of an @code{IN} parameter: +@cite{Unrestricted_Access} can be used in this way is to modify the +value of an @cite{IN} parameter: -@smallexample @c ada +@example procedure K (S : in String) is type R is access all Character; RV : R := S (3)'Unrestricted_Access; begin RV.all := 'a'; end; -@end smallexample +@end example -@noindent In general this is a risky approach. It may appear to "work" but such uses of -@code{Unrestricted_Access} are potentially non-portable, even from one version -of @code{GNAT} to another, so are best avoided if possible. - -@node Attribute Update -@unnumberedsec Attribute Update -@findex Update -@noindent -The @code{Update} attribute creates a copy of an array or record value +@cite{Unrestricted_Access} are potentially non-portable, even from one version +of @cite{GNAT} to another, so are best avoided if possible. + +@node Attribute Update,Attribute Valid_Scalars,Attribute Unrestricted_Access,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-update}@anchor{15b} +@section Attribute Update + + +@geindex Update + +The @cite{Update} attribute creates a copy of an array or record value with one or more modified components. The syntax is: -@smallexample @c ada +@example PREFIX'Update ( RECORD_COMPONENT_ASSOCIATION_LIST ) PREFIX'Update ( ARRAY_COMPONENT_ASSOCIATION @{, ARRAY_COMPONENT_ASSOCIATION @} ) PREFIX'Update ( MULTIDIMENSIONAL_ARRAY_COMPONENT_ASSOCIATION @@ -10143,54 +10792,50 @@ PREFIX'Update ( MULTIDIMENSIONAL_ARRAY_COMPONENT_ASSOCIATION MULTIDIMENSIONAL_ARRAY_COMPONENT_ASSOCIATION ::= INDEX_EXPRESSION_LIST_LIST => EXPRESSION INDEX_EXPRESSION_LIST_LIST ::= INDEX_EXPRESSION_LIST @{| INDEX_EXPRESSION_LIST @} INDEX_EXPRESSION_LIST ::= ( EXPRESSION @{, EXPRESSION @} ) -@end smallexample +@end example -@noindent -where @code{PREFIX} is the name of an array or record object, the -association list in parentheses does not contain an @code{others} -choice and the box symbol @code{<>} may not appear in any +where @cite{PREFIX} is the name of an array or record object, the +association list in parentheses does not contain an @cite{others} +choice and the box symbol @cite{<>} may not appear in any expression. The effect is to yield a copy of the array or record value which is unchanged apart from the components mentioned in the association list, which are changed to the indicated value. The original value of the array or record value is not affected. For example: -@smallexample @c ada +@example type Arr is Array (1 .. 5) of Integer; ... Avar1 : Arr := (1,2,3,4,5); Avar2 : Arr := Avar1'Update (2 => 10, 3 .. 4 => 20); -@end smallexample +@end example -@noindent -yields a value for @code{Avar2} of 1,10,20,20,5 with @code{Avar1} +yields a value for @cite{Avar2} of 1,10,20,20,5 with @cite{Avar1} begin unmodified. Similarly: -@smallexample @c ada +@example type Rec is A, B, C : Integer; ... Rvar1 : Rec := (A => 1, B => 2, C => 3); Rvar2 : Rec := Rvar1'Update (B => 20); -@end smallexample +@end example -@noindent -yields a value for @code{Rvar2} of (A => 1, B => 20, C => 3), -with @code{Rvar1} being unmodifed. +yields a value for @cite{Rvar2} of (A => 1, B => 20, C => 3), +with @cite{Rvar1} being unmodifed. Note that the value of the attribute reference is computed completely before it is used. This means that if you write: -@smallexample @c ada +@example Avar1 := Avar1'Update (1 => 10, 2 => Function_Call); -@end smallexample +@end example -@noindent -then the value of @code{Avar1} is not modified if @code{Function_Call} +then the value of @cite{Avar1} is not modified if @cite{Function_Call} raises an exception, unlike the effect of a series of direct assignments -to elements of @code{Avar1}. In general this requires that +to elements of @cite{Avar1}. In general this requires that two extra complete copies of the object are required, which should be kept in mind when considering efficiency. -The @code{Update} attribute cannot be applied to prefixes of a limited +The @cite{Update} attribute cannot be applied to prefixes of a limited type, and cannot reference discriminants in the case of a record type. The accessibility level of an Update attribute result object is defined as for an aggregate. @@ -10201,204 +10846,249 @@ in which case the modifications are processed left to right. Multi-dimensional arrays can be modified, as shown by this example: -@smallexample @c ada +@example A : array (1 .. 10, 1 .. 10) of Integer; .. A := A'Update ((1, 2) => 20, (3, 4) => 30); -@end smallexample +@end example -@noindent which changes element (1,2) to 20 and (3,4) to 30. -@node Attribute Valid_Scalars -@unnumberedsec Attribute Valid_Scalars -@findex Valid_Scalars -@noindent -The @code{'Valid_Scalars} attribute is intended to make it easier to +@node Attribute Valid_Scalars,Attribute VADS_Size,Attribute Update,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-valid-scalars}@anchor{15c} +@section Attribute Valid_Scalars + + +@geindex Valid_Scalars + +The @cite{'Valid_Scalars} attribute is intended to make it easier to check the validity of scalar subcomponents of composite objects. It -is defined for any prefix @code{X} that denotes an object. +is defined for any prefix @cite{X} that denotes an object. The value of this attribute is of the predefined type Boolean. -@code{X'Valid_Scalars} yields True if and only if evaluation of -@code{P'Valid} yields True for every scalar part P of X or if X has +@cite{X'Valid_Scalars} yields True if and only if evaluation of +@cite{P'Valid} yields True for every scalar part P of X or if X has no scalar parts. It is not specified in what order the scalar parts are checked, nor whether any more are checked after any one of them -is determined to be invalid. If the prefix @code{X} is of a class-wide -type @code{T'Class} (where @code{T} is the associated specific type), -or if the prefix @code{X} is of a specific tagged type @code{T}, then -only the scalar parts of components of @code{T} are traversed; in other -words, components of extensions of @code{T} are not traversed even if -@code{T'Class (X)'Tag /= T'Tag} . The compiler will issue a warning if it can +is determined to be invalid. If the prefix @cite{X} is of a class-wide +type @cite{T'Class} (where @cite{T} is the associated specific type), +or if the prefix @cite{X} is of a specific tagged type @cite{T}, then +only the scalar parts of components of @cite{T} are traversed; in other +words, components of extensions of @cite{T} are not traversed even if +@cite{T'Class (X)'Tag /= T'Tag} . The compiler will issue a warning if it can be determined at compile time that the prefix of the attribute has no scalar parts (e.g., if the prefix is of an access type, an interface type, an undiscriminated task type, or an undiscriminated protected type). -For scalar types, @code{Valid_Scalars} is equivalent to @code{Valid}. The use -of this attribute is not permitted for @code{Unchecked_Union} types for which +For scalar types, @cite{Valid_Scalars} is equivalent to @cite{Valid}. The use +of this attribute is not permitted for @cite{Unchecked_Union} types for which in general it is not possible to determine the values of the discriminants. -Note: @code{Valid_Scalars} can generate a lot of code, especially in the case +Note: @cite{Valid_Scalars} can generate a lot of code, especially in the case of a large variant record. If the attribute is called in many places in the same program applied to objects of the same type, it can reduce program size to write a function with a single use of the attribute, and then call that function from multiple places. -@node Attribute VADS_Size -@unnumberedsec Attribute VADS_Size -@cindex @code{Size}, VADS compatibility -@findex VADS_Size -@noindent -The @code{'VADS_Size} attribute is intended to make it easier to port -legacy code which relies on the semantics of @code{'Size} as implemented +@node Attribute VADS_Size,Attribute Value_Size,Attribute Valid_Scalars,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-vads-size}@anchor{15d} +@section Attribute VADS_Size + + +@geindex Size +@geindex VADS compatibility + +@geindex VADS_Size + +The @cite{'VADS_Size} attribute is intended to make it easier to port +legacy code which relies on the semantics of @cite{'Size} as implemented by the VADS Ada 83 compiler. GNAT makes a best effort at duplicating the -same semantic interpretation. In particular, @code{'VADS_Size} applied +same semantic interpretation. In particular, @cite{'VADS_Size} applied to a predefined or other primitive type with no Size clause yields the -Object_Size (for example, @code{Natural'Size} is 32 rather than 31 on -typical machines). In addition @code{'VADS_Size} applied to an object +Object_Size (for example, @cite{Natural'Size} is 32 rather than 31 on +typical machines). In addition @cite{'VADS_Size} applied to an object gives the result that would be obtained by applying the attribute to the corresponding type. -@node Attribute Value_Size -@unnumberedsec Attribute Value_Size -@cindex @code{Size}, setting for not-first subtype -@findex Value_Size -@code{@var{type}'Value_Size} is the number of bits required to represent -a value of the given subtype. It is the same as @code{@var{type}'Size}, -but, unlike @code{Size}, may be set for non-first subtypes. - -@node Attribute Wchar_T_Size -@unnumberedsec Attribute Wchar_T_Size -@findex Wchar_T_Size -@code{Standard'Wchar_T_Size} (@code{Standard} is the only permissible -prefix) provides the size in bits of the C @code{wchar_t} type +@node Attribute Value_Size,Attribute Wchar_T_Size,Attribute VADS_Size,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-value-size}@anchor{15e} +@section Attribute Value_Size + + +@geindex Size +@geindex setting for not-first subtype + +@geindex Value_Size + +@code{type'Value_Size} is the number of bits required to represent +a value of the given subtype. It is the same as @code{type'Size}, +but, unlike @cite{Size}, may be set for non-first subtypes. + +@node Attribute Wchar_T_Size,Attribute Word_Size,Attribute Value_Size,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-wchar-t-size}@anchor{15f} +@section Attribute Wchar_T_Size + + +@geindex Wchar_T_Size + +@cite{Standard'Wchar_T_Size} (@cite{Standard} is the only permissible +prefix) provides the size in bits of the C @cite{wchar_t} type primarily for constructing the definition of this type in -package @code{Interfaces.C}. The result is a static constant. +package @cite{Interfaces.C}. The result is a static constant. + +@node Attribute Word_Size,,Attribute Wchar_T_Size,Implementation Defined Attributes +@anchor{gnat_rm/implementation_defined_attributes attribute-word-size}@anchor{160} +@section Attribute Word_Size + + +@geindex Word_Size -@node Attribute Word_Size -@unnumberedsec Attribute Word_Size -@findex Word_Size -@code{Standard'Word_Size} (@code{Standard} is the only permissible -prefix) provides the value @code{System.Word_Size}. The result is +@cite{Standard'Word_Size} (@cite{Standard} is the only permissible +prefix) provides the value @cite{System.Word_Size}. The result is a static constant. -@node Standard and Implementation Defined Restrictions +@node Standard and Implementation Defined Restrictions,Implementation Advice,Implementation Defined Attributes,Top +@anchor{gnat_rm/standard_and_implementation_defined_restrictions standard-and-implementation-defined-restrictions}@anchor{9}@anchor{gnat_rm/standard_and_implementation_defined_restrictions doc}@anchor{161}@anchor{gnat_rm/standard_and_implementation_defined_restrictions id1}@anchor{162} @chapter Standard and Implementation Defined Restrictions -@noindent -All RM defined Restriction identifiers are implemented: -@itemize @bullet -@item language-defined restrictions (see 13.12.1) -@item tasking restrictions (see D.7) -@item high integrity restrictions (see H.4) +All Ada Reference Manual-defined Restriction identifiers are implemented: + + +@itemize * + +@item +language-defined restrictions (see 13.12.1) + +@item +tasking restrictions (see D.7) + +@item +high integrity restrictions (see H.4) @end itemize -@noindent GNAT implements additional restriction identifiers. All restrictions, whether language defined or GNAT-specific, are listed in the following. @menu -* Partition-Wide Restrictions:: -* Program Unit Level Restrictions:: +* Partition-Wide Restrictions:: +* Program Unit Level Restrictions:: + @end menu -@node Partition-Wide Restrictions +@node Partition-Wide Restrictions,Program Unit Level Restrictions,,Standard and Implementation Defined Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions partition-wide-restrictions}@anchor{163}@anchor{gnat_rm/standard_and_implementation_defined_restrictions id2}@anchor{164} @section Partition-Wide Restrictions + There are two separate lists of restriction identifiers. The first set requires consistency throughout a partition (in other words, if the restriction identifier is used for any compilation unit in the partition, then all compilation units in the partition must obey the restriction). @menu -* Immediate_Reclamation:: -* Max_Asynchronous_Select_Nesting:: -* Max_Entry_Queue_Length:: -* Max_Protected_Entries:: -* Max_Select_Alternatives:: -* Max_Storage_At_Blocking:: -* Max_Task_Entries:: -* Max_Tasks:: -* No_Abort_Statements:: -* No_Access_Parameter_Allocators:: -* No_Access_Subprograms:: -* No_Allocators:: -* No_Anonymous_Allocators:: -* No_Calendar:: -* No_Coextensions:: -* No_Default_Initialization:: -* No_Delay:: -* No_Dependence:: -* No_Direct_Boolean_Operators:: -* No_Dispatch:: -* No_Dispatching_Calls:: -* No_Dynamic_Attachment:: -* No_Dynamic_Priorities:: -* No_Entry_Calls_In_Elaboration_Code:: -* No_Enumeration_Maps:: -* No_Exception_Handlers:: -* No_Exception_Propagation:: -* No_Exception_Registration:: -* No_Exceptions:: -* No_Finalization:: -* No_Fixed_Point:: -* No_Floating_Point:: -* No_Implicit_Conditionals:: -* No_Implicit_Dynamic_Code:: -* No_Implicit_Heap_Allocations:: -* No_Implicit_Loops:: -* No_Initialize_Scalars:: -* No_IO:: -* No_Local_Allocators:: -* No_Local_Protected_Objects:: -* No_Local_Timing_Events:: -* No_Long_Long_Integers:: -* No_Multiple_Elaboration:: -* No_Nested_Finalization:: -* No_Protected_Type_Allocators:: -* No_Protected_Types:: -* No_Recursion:: -* No_Reentrancy:: -* No_Relative_Delay:: -* No_Requeue_Statements:: -* No_Secondary_Stack:: -* No_Select_Statements:: -* No_Specific_Termination_Handlers:: -* No_Specification_of_Aspect:: -* No_Standard_Allocators_After_Elaboration:: -* No_Standard_Storage_Pools:: -* No_Stream_Optimizations:: -* No_Streams:: -* No_Task_Allocators:: -* No_Task_Attributes_Package:: -* No_Task_Hierarchy:: -* No_Task_Termination:: -* No_Tasking:: -* No_Terminate_Alternatives:: -* No_Unchecked_Access:: -* Simple_Barriers:: -* Static_Priorities:: -* Static_Storage_Size:: +* Immediate_Reclamation:: +* Max_Asynchronous_Select_Nesting:: +* Max_Entry_Queue_Length:: +* Max_Protected_Entries:: +* Max_Select_Alternatives:: +* Max_Storage_At_Blocking:: +* Max_Task_Entries:: +* Max_Tasks:: +* No_Abort_Statements:: +* No_Access_Parameter_Allocators:: +* No_Access_Subprograms:: +* No_Allocators:: +* No_Anonymous_Allocators:: +* No_Calendar:: +* No_Coextensions:: +* No_Default_Initialization:: +* No_Delay:: +* No_Dependence:: +* No_Direct_Boolean_Operators:: +* No_Dispatch:: +* No_Dispatching_Calls:: +* No_Dynamic_Attachment:: +* No_Dynamic_Priorities:: +* No_Entry_Calls_In_Elaboration_Code:: +* No_Enumeration_Maps:: +* No_Exception_Handlers:: +* No_Exception_Propagation:: +* No_Exception_Registration:: +* No_Exceptions:: +* No_Finalization:: +* No_Fixed_Point:: +* No_Floating_Point:: +* No_Implicit_Conditionals:: +* No_Implicit_Dynamic_Code:: +* No_Implicit_Heap_Allocations:: +* No_Implicit_Loops:: +* No_Initialize_Scalars:: +* No_IO:: +* No_Local_Allocators:: +* No_Local_Protected_Objects:: +* No_Local_Timing_Events:: +* No_Long_Long_Integers:: +* No_Multiple_Elaboration:: +* No_Nested_Finalization:: +* No_Protected_Type_Allocators:: +* No_Protected_Types:: +* No_Recursion:: +* No_Reentrancy:: +* No_Relative_Delay:: +* No_Requeue_Statements:: +* No_Secondary_Stack:: +* No_Select_Statements:: +* No_Specific_Termination_Handlers:: +* No_Specification_of_Aspect:: +* No_Standard_Allocators_After_Elaboration:: +* No_Standard_Storage_Pools:: +* No_Stream_Optimizations:: +* No_Streams:: +* No_Task_Allocators:: +* No_Task_Attributes_Package:: +* No_Task_Hierarchy:: +* No_Task_Termination:: +* No_Tasking:: +* No_Terminate_Alternatives:: +* No_Unchecked_Access:: +* No_Use_Of_Entity:: +* Simple_Barriers:: +* Static_Priorities:: +* Static_Storage_Size:: + @end menu -@node Immediate_Reclamation -@unnumberedsubsec Immediate_Reclamation -@findex Immediate_Reclamation +@node Immediate_Reclamation,Max_Asynchronous_Select_Nesting,,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions immediate-reclamation}@anchor{165} +@subsection Immediate_Reclamation + + +@geindex Immediate_Reclamation + [RM H.4] This restriction ensures that, except for storage occupied by objects created by allocators and not deallocated via unchecked deallocation, any storage reserved at run time for an object is immediately reclaimed when the object no longer exists. -@node Max_Asynchronous_Select_Nesting -@unnumberedsubsec Max_Asynchronous_Select_Nesting -@findex Max_Asynchronous_Select_Nesting +@node Max_Asynchronous_Select_Nesting,Max_Entry_Queue_Length,Immediate_Reclamation,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions max-asynchronous-select-nesting}@anchor{166} +@subsection Max_Asynchronous_Select_Nesting + + +@geindex Max_Asynchronous_Select_Nesting + [RM D.7] Specifies the maximum dynamic nesting level of asynchronous selects. Violations of this restriction with a value of zero are detected at compile time. Violations of this restriction with values other than zero cause Storage_Error to be raised. -@node Max_Entry_Queue_Length -@unnumberedsubsec Max_Entry_Queue_Length -@findex Max_Entry_Queue_Length +@node Max_Entry_Queue_Length,Max_Protected_Entries,Max_Asynchronous_Select_Nesting,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions max-entry-queue-length}@anchor{167} +@subsection Max_Entry_Queue_Length + + +@geindex Max_Entry_Queue_Length + [RM D.7] This restriction is a declaration that any protected entry compiled in the scope of the restriction has at most the specified number of tasks waiting on the entry at any one time, and so no queue is required. @@ -10406,95 +11096,147 @@ Note that this restriction is checked at run time. Violation of this restriction results in the raising of Program_Error exception at the point of the call. -@findex Max_Entry_Queue_Depth -The restriction @code{Max_Entry_Queue_Depth} is recognized as a -synonym for @code{Max_Entry_Queue_Length}. This is retained for historical +@geindex Max_Entry_Queue_Depth + +The restriction @cite{Max_Entry_Queue_Depth} is recognized as a +synonym for @cite{Max_Entry_Queue_Length}. This is retained for historical compatibility purposes (and a warning will be generated for its use if warnings on obsolescent features are activated). -@node Max_Protected_Entries -@unnumberedsubsec Max_Protected_Entries -@findex Max_Protected_Entries +@node Max_Protected_Entries,Max_Select_Alternatives,Max_Entry_Queue_Length,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions max-protected-entries}@anchor{168} +@subsection Max_Protected_Entries + + +@geindex Max_Protected_Entries + [RM D.7] Specifies the maximum number of entries per protected type. The bounds of every entry family of a protected unit shall be static, or shall be defined by a discriminant of a subtype whose corresponding bound is static. -@node Max_Select_Alternatives -@unnumberedsubsec Max_Select_Alternatives -@findex Max_Select_Alternatives +@node Max_Select_Alternatives,Max_Storage_At_Blocking,Max_Protected_Entries,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions max-select-alternatives}@anchor{169} +@subsection Max_Select_Alternatives + + +@geindex Max_Select_Alternatives + [RM D.7] Specifies the maximum number of alternatives in a selective accept. -@node Max_Storage_At_Blocking -@unnumberedsubsec Max_Storage_At_Blocking -@findex Max_Storage_At_Blocking +@node Max_Storage_At_Blocking,Max_Task_Entries,Max_Select_Alternatives,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions max-storage-at-blocking}@anchor{16a} +@subsection Max_Storage_At_Blocking + + +@geindex Max_Storage_At_Blocking + [RM D.7] Specifies the maximum portion (in storage elements) of a task's Storage_Size that can be retained by a blocked task. A violation of this restriction causes Storage_Error to be raised. -@node Max_Task_Entries -@unnumberedsubsec Max_Task_Entries -@findex Max_Task_Entries +@node Max_Task_Entries,Max_Tasks,Max_Storage_At_Blocking,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions max-task-entries}@anchor{16b} +@subsection Max_Task_Entries + + +@geindex Max_Task_Entries + [RM D.7] Specifies the maximum number of entries per task. The bounds of every entry family of a task unit shall be static, or shall be defined by a discriminant of a subtype whose corresponding bound is static. -@node Max_Tasks -@unnumberedsubsec Max_Tasks -@findex Max_Tasks +@node Max_Tasks,No_Abort_Statements,Max_Task_Entries,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions max-tasks}@anchor{16c} +@subsection Max_Tasks + + +@geindex Max_Tasks + [RM D.7] Specifies the maximum number of task that may be created, not counting the creation of the environment task. Violations of this restriction with a value of zero are detected at compile time. Violations of this restriction with values other than zero cause Storage_Error to be raised. -@node No_Abort_Statements -@unnumberedsubsec No_Abort_Statements -@findex No_Abort_Statements +@node No_Abort_Statements,No_Access_Parameter_Allocators,Max_Tasks,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-abort-statements}@anchor{16d} +@subsection No_Abort_Statements + + +@geindex No_Abort_Statements + [RM D.7] There are no abort_statements, and there are no calls to Task_Identification.Abort_Task. -@node No_Access_Parameter_Allocators -@unnumberedsubsec No_Access_Parameter_Allocators -@findex No_Access_Parameter_Allocators +@node No_Access_Parameter_Allocators,No_Access_Subprograms,No_Abort_Statements,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-access-parameter-allocators}@anchor{16e} +@subsection No_Access_Parameter_Allocators + + +@geindex No_Access_Parameter_Allocators + [RM H.4] This restriction ensures at compile time that there are no occurrences of an allocator as the actual parameter to an access parameter. -@node No_Access_Subprograms -@unnumberedsubsec No_Access_Subprograms -@findex No_Access_Subprograms +@node No_Access_Subprograms,No_Allocators,No_Access_Parameter_Allocators,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-access-subprograms}@anchor{16f} +@subsection No_Access_Subprograms + + +@geindex No_Access_Subprograms + [RM H.4] This restriction ensures at compile time that there are no declarations of access-to-subprogram types. -@node No_Allocators -@unnumberedsubsec No_Allocators -@findex No_Allocators +@node No_Allocators,No_Anonymous_Allocators,No_Access_Subprograms,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-allocators}@anchor{170} +@subsection No_Allocators + + +@geindex No_Allocators + [RM H.4] This restriction ensures at compile time that there are no occurrences of an allocator. -@node No_Anonymous_Allocators -@unnumberedsubsec No_Anonymous_Allocators -@findex No_Anonymous_Allocators +@node No_Anonymous_Allocators,No_Calendar,No_Allocators,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-anonymous-allocators}@anchor{171} +@subsection No_Anonymous_Allocators + + +@geindex No_Anonymous_Allocators + [RM H.4] This restriction ensures at compile time that there are no occurrences of an allocator of anonymous access type. -@node No_Calendar -@unnumberedsubsec No_Calendar -@findex No_Calendar +@node No_Calendar,No_Coextensions,No_Anonymous_Allocators,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-calendar}@anchor{172} +@subsection No_Calendar + + +@geindex No_Calendar + [GNAT] This restriction ensures at compile time that there is no implicit or -explicit dependence on the package @code{Ada.Calendar}. +explicit dependence on the package @cite{Ada.Calendar}. + +@node No_Coextensions,No_Default_Initialization,No_Calendar,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-coextensions}@anchor{173} +@subsection No_Coextensions + + +@geindex No_Coextensions -@node No_Coextensions -@unnumberedsubsec No_Coextensions -@findex No_Coextensions [RM H.4] This restriction ensures at compile time that there are no coextensions. See 3.10.2. -@node No_Default_Initialization -@unnumberedsubsec No_Default_Initialization -@findex No_Default_Initialization +@node No_Default_Initialization,No_Delay,No_Coextensions,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-default-initialization}@anchor{174} +@subsection No_Default_Initialization + + +@geindex No_Default_Initialization [GNAT] This restriction prohibits any instance of default initialization of variables. The binder implements a consistency rule which prevents @@ -10506,36 +11248,56 @@ in conjunction with Initialize_Scalars or Normalize_Scalars, the effect is to prohibit all cases of variables declared without a specific initializer (including the case of OUT scalar parameters). -@node No_Delay -@unnumberedsubsec No_Delay -@findex No_Delay +@node No_Delay,No_Dependence,No_Default_Initialization,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-delay}@anchor{175} +@subsection No_Delay + + +@geindex No_Delay + [RM H.4] This restriction ensures at compile time that there are no delay statements and no dependences on package Calendar. -@node No_Dependence -@unnumberedsubsec No_Dependence -@findex No_Dependence +@node No_Dependence,No_Direct_Boolean_Operators,No_Delay,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-dependence}@anchor{176} +@subsection No_Dependence + + +@geindex No_Dependence + [RM 13.12.1] This restriction checks at compile time that there are no dependence on a library unit. -@node No_Direct_Boolean_Operators -@unnumberedsubsec No_Direct_Boolean_Operators -@findex No_Direct_Boolean_Operators +@node No_Direct_Boolean_Operators,No_Dispatch,No_Dependence,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-direct-boolean-operators}@anchor{177} +@subsection No_Direct_Boolean_Operators + + +@geindex No_Direct_Boolean_Operators + [GNAT] This restriction ensures that no logical operators (and/or/xor) are used on operands of type Boolean (or any type derived from Boolean). This is intended for use in safety critical programs where the certification protocol requires the use of short-circuit (and then, or else) forms for all composite boolean operations. -@node No_Dispatch -@unnumberedsubsec No_Dispatch -@findex No_Dispatch +@node No_Dispatch,No_Dispatching_Calls,No_Direct_Boolean_Operators,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-dispatch}@anchor{178} +@subsection No_Dispatch + + +@geindex No_Dispatch + [RM H.4] This restriction ensures at compile time that there are no -occurrences of @code{T'Class}, for any (tagged) subtype @code{T}. +occurrences of @cite{T'Class}, for any (tagged) subtype @cite{T}. + +@node No_Dispatching_Calls,No_Dynamic_Attachment,No_Dispatch,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-dispatching-calls}@anchor{179} +@subsection No_Dispatching_Calls + + +@geindex No_Dispatching_Calls -@node No_Dispatching_Calls -@unnumberedsubsec No_Dispatching_Calls -@findex No_Dispatching_Calls [GNAT] This restriction ensures at compile time that the code generated by the compiler involves no dispatching calls. The use of this restriction allows the safe use of record extensions, classwide membership tests and other classwide @@ -10546,11 +11308,11 @@ in the implementation of class-wide objects assignments. The membership test is allowed in the presence of this restriction, because its implementation requires no dispatching. This restriction is comparable to the official Ada restriction -@code{No_Dispatch} except that it is a bit less restrictive in that it allows +@cite{No_Dispatch} except that it is a bit less restrictive in that it allows all classwide constructs that do not imply dispatching. The following example indicates constructs that violate this restriction. -@smallexample +@example package Pkg is type T is tagged record Data : Natural; @@ -10588,66 +11350,91 @@ begin null; end if; end Example; -@end smallexample +@end example + +@node No_Dynamic_Attachment,No_Dynamic_Priorities,No_Dispatching_Calls,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-dynamic-attachment}@anchor{17a} +@subsection No_Dynamic_Attachment + + +@geindex No_Dynamic_Attachment -@node No_Dynamic_Attachment -@unnumberedsubsec No_Dynamic_Attachment -@findex No_Dynamic_Attachment [RM D.7] This restriction ensures that there is no call to any of the operations defined in package Ada.Interrupts (Is_Reserved, Is_Attached, Current_Handler, Attach_Handler, Exchange_Handler, Detach_Handler, and Reference). -@findex No_Dynamic_Interrupts -The restriction @code{No_Dynamic_Interrupts} is recognized as a -synonym for @code{No_Dynamic_Attachment}. This is retained for historical +@geindex No_Dynamic_Interrupts + +The restriction @cite{No_Dynamic_Interrupts} is recognized as a +synonym for @cite{No_Dynamic_Attachment}. This is retained for historical compatibility purposes (and a warning will be generated for its use if warnings on obsolescent features are activated). -@node No_Dynamic_Priorities -@unnumberedsubsec No_Dynamic_Priorities -@findex No_Dynamic_Priorities +@node No_Dynamic_Priorities,No_Entry_Calls_In_Elaboration_Code,No_Dynamic_Attachment,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-dynamic-priorities}@anchor{17b} +@subsection No_Dynamic_Priorities + + +@geindex No_Dynamic_Priorities + [RM D.7] There are no semantic dependencies on the package Dynamic_Priorities. -@node No_Entry_Calls_In_Elaboration_Code -@unnumberedsubsec No_Entry_Calls_In_Elaboration_Code -@findex No_Entry_Calls_In_Elaboration_Code +@node No_Entry_Calls_In_Elaboration_Code,No_Enumeration_Maps,No_Dynamic_Priorities,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-entry-calls-in-elaboration-code}@anchor{17c} +@subsection No_Entry_Calls_In_Elaboration_Code + + +@geindex No_Entry_Calls_In_Elaboration_Code + [GNAT] This restriction ensures at compile time that no task or protected entry calls are made during elaboration code. As a result of the use of this restriction, the compiler can assume that no code past an accept statement in a task can be executed at elaboration time. -@node No_Enumeration_Maps -@unnumberedsubsec No_Enumeration_Maps -@findex No_Enumeration_Maps +@node No_Enumeration_Maps,No_Exception_Handlers,No_Entry_Calls_In_Elaboration_Code,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-enumeration-maps}@anchor{17d} +@subsection No_Enumeration_Maps + + +@geindex No_Enumeration_Maps + [GNAT] This restriction ensures at compile time that no operations requiring enumeration maps are used (that is Image and Value attributes applied to enumeration types). -@node No_Exception_Handlers -@unnumberedsubsec No_Exception_Handlers -@findex No_Exception_Handlers +@node No_Exception_Handlers,No_Exception_Propagation,No_Enumeration_Maps,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-exception-handlers}@anchor{17e} +@subsection No_Exception_Handlers + + +@geindex No_Exception_Handlers + [GNAT] This restriction ensures at compile time that there are no explicit exception handlers. It also indicates that no exception propagation will be provided. In this mode, exceptions may be raised but will result in an immediate call to the last chance handler, a routine that the user must define with the following profile: -@smallexample @c ada +@example procedure Last_Chance_Handler (Source_Location : System.Address; Line : Integer); pragma Export (C, Last_Chance_Handler, "__gnat_last_chance_handler"); -@end smallexample +@end example The parameter is a C null-terminated string representing a message to be associated with the exception (typically the source location of the raise statement generated by the compiler). The Line parameter when nonzero represents the line number in the source program where the raise occurs. -@node No_Exception_Propagation -@unnumberedsubsec No_Exception_Propagation -@findex No_Exception_Propagation +@node No_Exception_Propagation,No_Exception_Registration,No_Exception_Handlers,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-exception-propagation}@anchor{17f} +@subsection No_Exception_Propagation + + +@geindex No_Exception_Propagation + [GNAT] This restriction guarantees that exceptions are never propagated to an outer subprogram scope. The only case in which an exception may be raised is when the handler is statically in the same subprogram, so @@ -10658,9 +11445,13 @@ exception occurrence identifier (exception choice). In addition, use of the package GNAT.Current_Exception is not permitted, and reraise statements (raise with no operand) are not permitted. -@node No_Exception_Registration -@unnumberedsubsec No_Exception_Registration -@findex No_Exception_Registration +@node No_Exception_Registration,No_Exceptions,No_Exception_Propagation,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-exception-registration}@anchor{180} +@subsection No_Exception_Registration + + +@geindex No_Exception_Registration + [GNAT] This restriction ensures at compile time that no stream operations for types Exception_Id or Exception_Occurrence are used. This also makes it impossible to pass exceptions to or from a partition with this restriction @@ -10668,54 +11459,84 @@ in a distributed environment. If this restriction is active, the generated code is simplified by omitting the otherwise-required global registration of exceptions when they are declared. -@node No_Exceptions -@unnumberedsubsec No_Exceptions -@findex No_Exceptions +@node No_Exceptions,No_Finalization,No_Exception_Registration,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-exceptions}@anchor{181} +@subsection No_Exceptions + + +@geindex No_Exceptions + [RM H.4] This restriction ensures at compile time that there are no raise statements and no exception handlers. -@node No_Finalization -@unnumberedsubsec No_Finalization -@findex No_Finalization +@node No_Finalization,No_Fixed_Point,No_Exceptions,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-finalization}@anchor{182} +@subsection No_Finalization + + +@geindex No_Finalization + [GNAT] This restriction disables the language features described in chapter 7.6 of the Ada 2005 RM as well as all form of code generation performed by the compiler to support these features. The following types are no longer considered controlled when this restriction is in effect: -@itemize @bullet -@item -@code{Ada.Finalization.Controlled} -@item -@code{Ada.Finalization.Limited_Controlled} -@item -Derivations from @code{Controlled} or @code{Limited_Controlled} -@item + + +@itemize * + +@item +@cite{Ada.Finalization.Controlled} + +@item +@cite{Ada.Finalization.Limited_Controlled} + +@item +Derivations from @cite{Controlled} or @cite{Limited_Controlled} + +@item Class-wide types -@item + +@item Protected types -@item + +@item Task types -@item + +@item Array and record types with controlled components @end itemize + The compiler no longer generates code to initialize, finalize or adjust an object or a nested component, either declared on the stack or on the heap. The deallocation of a controlled object no longer finalizes its contents. -@node No_Fixed_Point -@unnumberedsubsec No_Fixed_Point -@findex No_Fixed_Point +@node No_Fixed_Point,No_Floating_Point,No_Finalization,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-fixed-point}@anchor{183} +@subsection No_Fixed_Point + + +@geindex No_Fixed_Point + [RM H.4] This restriction ensures at compile time that there are no occurrences of fixed point types and operations. -@node No_Floating_Point -@unnumberedsubsec No_Floating_Point -@findex No_Floating_Point +@node No_Floating_Point,No_Implicit_Conditionals,No_Fixed_Point,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-floating-point}@anchor{184} +@subsection No_Floating_Point + + +@geindex No_Floating_Point + [RM H.4] This restriction ensures at compile time that there are no occurrences of floating point types and operations. -@node No_Implicit_Conditionals -@unnumberedsubsec No_Implicit_Conditionals -@findex No_Implicit_Conditionals +@node No_Implicit_Conditionals,No_Implicit_Dynamic_Code,No_Floating_Point,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implicit-conditionals}@anchor{185} +@subsection No_Implicit_Conditionals + + +@geindex No_Implicit_Conditionals + [GNAT] This restriction ensures that the generated code does not contain any implicit conditionals, either by modifying the generated code where possible, or by rejecting any construct that would otherwise generate an implicit @@ -10725,15 +11546,20 @@ well. To control the latter, constraint checks can be suppressed in the normal manner. Constructs generating implicit conditionals include comparisons of composite objects and the Max/Min attributes. -@node No_Implicit_Dynamic_Code -@unnumberedsubsec No_Implicit_Dynamic_Code -@findex No_Implicit_Dynamic_Code -@cindex trampoline -[GNAT] This restriction prevents the compiler from building ``trampolines''. +@node No_Implicit_Dynamic_Code,No_Implicit_Heap_Allocations,No_Implicit_Conditionals,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implicit-dynamic-code}@anchor{186} +@subsection No_Implicit_Dynamic_Code + + +@geindex No_Implicit_Dynamic_Code + +@geindex trampoline + +[GNAT] This restriction prevents the compiler from building 'trampolines'. This is a structure that is built on the stack and contains dynamic code to be executed at run time. On some targets, a trampoline is -built for the following features: @code{Access}, -@code{Unrestricted_Access}, or @code{Address} of a nested subprogram; +built for the following features: @cite{Access}, +@cite{Unrestricted_Access}, or @cite{Address} of a nested subprogram; nested task bodies; primitive operations of nested tagged types. Trampolines do not work on machines that prevent execution of stack data. For example, on windows systems, enabling DEP (data execution @@ -10744,198 +11570,295 @@ On many targets, trampolines have been largely eliminated. Look at the version of system.ads for your target --- if it has Always_Compatible_Rep equal to False, then trampolines are largely eliminated. In particular, a trampoline is built for the following -features: @code{Address} of a nested subprogram; -@code{Access} or @code{Unrestricted_Access} of a nested subprogram, +features: @cite{Address} of a nested subprogram; +@cite{Access} or @cite{Unrestricted_Access} of a nested subprogram, but only if pragma Favor_Top_Level applies, or the access type has a foreign-language convention; primitive operations of nested tagged types. -@node No_Implicit_Heap_Allocations -@unnumberedsubsec No_Implicit_Heap_Allocations -@findex No_Implicit_Heap_Allocations +@node No_Implicit_Heap_Allocations,No_Implicit_Loops,No_Implicit_Dynamic_Code,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implicit-heap-allocations}@anchor{187} +@subsection No_Implicit_Heap_Allocations + + +@geindex No_Implicit_Heap_Allocations + [RM D.7] No constructs are allowed to cause implicit heap allocation. -@node No_Implicit_Loops -@unnumberedsubsec No_Implicit_Loops -@findex No_Implicit_Loops +@node No_Implicit_Loops,No_Initialize_Scalars,No_Implicit_Heap_Allocations,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implicit-loops}@anchor{188} +@subsection No_Implicit_Loops + + +@geindex No_Implicit_Loops + [GNAT] This restriction ensures that the generated code does not contain any -implicit @code{for} loops, either by modifying +implicit @cite{for} loops, either by modifying the generated code where possible, or by rejecting any construct that would otherwise generate an implicit -@code{for} loop. If this restriction is active, it is possible to build +@cite{for} loop. If this restriction is active, it is possible to build large array aggregates with all static components without generating an intermediate temporary, and without generating a loop to initialize individual components. Otherwise, a loop is created for arrays larger than about 5000 scalar components. -@node No_Initialize_Scalars -@unnumberedsubsec No_Initialize_Scalars -@findex No_Initialize_Scalars +@node No_Initialize_Scalars,No_IO,No_Implicit_Loops,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-initialize-scalars}@anchor{189} +@subsection No_Initialize_Scalars + + +@geindex No_Initialize_Scalars + [GNAT] This restriction ensures that no unit in the partition is compiled with pragma Initialize_Scalars. This allows the generation of more efficient code, and in particular eliminates dummy null initialization routines that are otherwise generated for some record and array types. -@node No_IO -@unnumberedsubsec No_IO -@findex No_IO +@node No_IO,No_Local_Allocators,No_Initialize_Scalars,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-io}@anchor{18a} +@subsection No_IO + + +@geindex No_IO + [RM H.4] This restriction ensures at compile time that there are no dependences on any of the library units Sequential_IO, Direct_IO, Text_IO, Wide_Text_IO, Wide_Wide_Text_IO, or Stream_IO. -@node No_Local_Allocators -@unnumberedsubsec No_Local_Allocators -@findex No_Local_Allocators +@node No_Local_Allocators,No_Local_Protected_Objects,No_IO,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-local-allocators}@anchor{18b} +@subsection No_Local_Allocators + + +@geindex No_Local_Allocators + [RM H.4] This restriction ensures at compile time that there are no occurrences of an allocator in subprograms, generic subprograms, tasks, and entry bodies. -@node No_Local_Protected_Objects -@unnumberedsubsec No_Local_Protected_Objects -@findex No_Local_Protected_Objects +@node No_Local_Protected_Objects,No_Local_Timing_Events,No_Local_Allocators,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-local-protected-objects}@anchor{18c} +@subsection No_Local_Protected_Objects + + +@geindex No_Local_Protected_Objects + [RM D.7] This restriction ensures at compile time that protected objects are only declared at the library level. -@node No_Local_Timing_Events -@unnumberedsubsec No_Local_Timing_Events -@findex No_Local_Timing_Events +@node No_Local_Timing_Events,No_Long_Long_Integers,No_Local_Protected_Objects,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-local-timing-events}@anchor{18d} +@subsection No_Local_Timing_Events + + +@geindex No_Local_Timing_Events + [RM D.7] All objects of type Ada.Timing_Events.Timing_Event are declared at the library level. -@node No_Long_Long_Integers -@unnumberedsubsec No_Long_Long_Integers -@findex No_Long_Long_Integers +@node No_Long_Long_Integers,No_Multiple_Elaboration,No_Local_Timing_Events,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-long-long-integers}@anchor{18e} +@subsection No_Long_Long_Integers + + +@geindex No_Long_Long_Integers + [GNAT] This partition-wide restriction forbids any explicit reference to type Standard.Long_Long_Integer, and also forbids declaring range types whose implicit base type is Long_Long_Integer, and modular types whose size exceeds Long_Integer'Size. -@node No_Multiple_Elaboration -@unnumberedsubsec No_Multiple_Elaboration -@findex No_Multiple_Elaboration +@node No_Multiple_Elaboration,No_Nested_Finalization,No_Long_Long_Integers,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-multiple-elaboration}@anchor{18f} +@subsection No_Multiple_Elaboration + + +@geindex No_Multiple_Elaboration + [GNAT] Normally each package contains a 16-bit counter used to check for access before elaboration, and to control multiple elaboration attempts. This counter is eliminated for units compiled with the static model -of elaboration if restriction @code{No_Elaboration_Code} +of elaboration if restriction @cite{No_Elaboration_Code} is active but because of the need to check for multiple elaboration in the general case, these counters cannot be eliminated if elaboration code may be present. The -restriction @code{No_Multiple_Elaboration} +restriction @cite{No_Multiple_Elaboration} allows suppression of these counters in static elaboration units even if they do have elaboration code. If this restriction is used, then the situations in which multiple elaboration is possible, including non-Ada main programs, and Stand Alone libraries, are not permitted, and will be diagnosed by the binder. -@node No_Nested_Finalization -@unnumberedsubsec No_Nested_Finalization -@findex No_Nested_Finalization +@node No_Nested_Finalization,No_Protected_Type_Allocators,No_Multiple_Elaboration,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-nested-finalization}@anchor{190} +@subsection No_Nested_Finalization + + +@geindex No_Nested_Finalization + [RM D.7] All objects requiring finalization are declared at the library level. -@node No_Protected_Type_Allocators -@unnumberedsubsec No_Protected_Type_Allocators -@findex No_Protected_Type_Allocators +@node No_Protected_Type_Allocators,No_Protected_Types,No_Nested_Finalization,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-protected-type-allocators}@anchor{191} +@subsection No_Protected_Type_Allocators + + +@geindex No_Protected_Type_Allocators + [RM D.7] This restriction ensures at compile time that there are no allocator expressions that attempt to allocate protected objects. -@node No_Protected_Types -@unnumberedsubsec No_Protected_Types -@findex No_Protected_Types +@node No_Protected_Types,No_Recursion,No_Protected_Type_Allocators,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-protected-types}@anchor{192} +@subsection No_Protected_Types + + +@geindex No_Protected_Types + [RM H.4] This restriction ensures at compile time that there are no declarations of protected types or protected objects. -@node No_Recursion -@unnumberedsubsec No_Recursion -@findex No_Recursion +@node No_Recursion,No_Reentrancy,No_Protected_Types,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-recursion}@anchor{193} +@subsection No_Recursion + + +@geindex No_Recursion + [RM H.4] A program execution is erroneous if a subprogram is invoked as part of its execution. -@node No_Reentrancy -@unnumberedsubsec No_Reentrancy -@findex No_Reentrancy +@node No_Reentrancy,No_Relative_Delay,No_Recursion,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-reentrancy}@anchor{194} +@subsection No_Reentrancy + + +@geindex No_Reentrancy + [RM H.4] A program execution is erroneous if a subprogram is executed by two tasks at the same time. -@node No_Relative_Delay -@unnumberedsubsec No_Relative_Delay -@findex No_Relative_Delay +@node No_Relative_Delay,No_Requeue_Statements,No_Reentrancy,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-relative-delay}@anchor{195} +@subsection No_Relative_Delay + + +@geindex No_Relative_Delay + [RM D.7] This restriction ensures at compile time that there are no delay -relative statements and prevents expressions such as @code{delay 1.23;} from +relative statements and prevents expressions such as @cite{delay 1.23;} from appearing in source code. -@node No_Requeue_Statements -@unnumberedsubsec No_Requeue_Statements -@findex No_Requeue_Statements +@node No_Requeue_Statements,No_Secondary_Stack,No_Relative_Delay,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-requeue-statements}@anchor{196} +@subsection No_Requeue_Statements + + +@geindex No_Requeue_Statements + [RM D.7] This restriction ensures at compile time that no requeue statements -are permitted and prevents keyword @code{requeue} from being used in source +are permitted and prevents keyword @cite{requeue} from being used in source code. -@findex No_Requeue -The restriction @code{No_Requeue} is recognized as a -synonym for @code{No_Requeue_Statements}. This is retained for historical +@geindex No_Requeue + +The restriction @cite{No_Requeue} is recognized as a +synonym for @cite{No_Requeue_Statements}. This is retained for historical compatibility purposes (and a warning will be generated for its use if warnings on oNobsolescent features are activated). -@node No_Secondary_Stack -@unnumberedsubsec No_Secondary_Stack -@findex No_Secondary_Stack +@node No_Secondary_Stack,No_Select_Statements,No_Requeue_Statements,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-secondary-stack}@anchor{197} +@subsection No_Secondary_Stack + + +@geindex No_Secondary_Stack + [GNAT] This restriction ensures at compile time that the generated code does not contain any reference to the secondary stack. The secondary stack is used to implement functions returning unconstrained objects (arrays or records) on some targets. -@node No_Select_Statements -@unnumberedsubsec No_Select_Statements -@findex No_Select_Statements +@node No_Select_Statements,No_Specific_Termination_Handlers,No_Secondary_Stack,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-select-statements}@anchor{198} +@subsection No_Select_Statements + + +@geindex No_Select_Statements + [RM D.7] This restriction ensures at compile time no select statements of any -kind are permitted, that is the keyword @code{select} may not appear. +kind are permitted, that is the keyword @cite{select} may not appear. + +@node No_Specific_Termination_Handlers,No_Specification_of_Aspect,No_Select_Statements,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-specific-termination-handlers}@anchor{199} +@subsection No_Specific_Termination_Handlers + + +@geindex No_Specific_Termination_Handlers -@node No_Specific_Termination_Handlers -@unnumberedsubsec No_Specific_Termination_Handlers -@findex No_Specific_Termination_Handlers [RM D.7] There are no calls to Ada.Task_Termination.Set_Specific_Handler or to Ada.Task_Termination.Specific_Handler. -@node No_Specification_of_Aspect -@unnumberedsubsec No_Specification_of_Aspect -@findex No_Specification_of_Aspect +@node No_Specification_of_Aspect,No_Standard_Allocators_After_Elaboration,No_Specific_Termination_Handlers,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-specification-of-aspect}@anchor{19a} +@subsection No_Specification_of_Aspect + + +@geindex No_Specification_of_Aspect + [RM 13.12.1] This restriction checks at compile time that no aspect specification, attribute definition clause, or pragma is given for a given aspect. -@node No_Standard_Allocators_After_Elaboration -@unnumberedsubsec No_Standard_Allocators_After_Elaboration -@findex No_Standard_Allocators_After_Elaboration +@node No_Standard_Allocators_After_Elaboration,No_Standard_Storage_Pools,No_Specification_of_Aspect,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-standard-allocators-after-elaboration}@anchor{19b} +@subsection No_Standard_Allocators_After_Elaboration + + +@geindex No_Standard_Allocators_After_Elaboration + [RM D.7] Specifies that an allocator using a standard storage pool should never be evaluated at run time after the elaboration of the library items of the partition has completed. Otherwise, Storage_Error is raised. -@node No_Standard_Storage_Pools -@unnumberedsubsec No_Standard_Storage_Pools -@findex No_Standard_Storage_Pools +@node No_Standard_Storage_Pools,No_Stream_Optimizations,No_Standard_Allocators_After_Elaboration,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-standard-storage-pools}@anchor{19c} +@subsection No_Standard_Storage_Pools + + +@geindex No_Standard_Storage_Pools + [GNAT] This restriction ensures at compile time that no access types use the standard default storage pool. Any access type declared must have an explicit Storage_Pool attribute defined specifying a user-defined storage pool. -@node No_Stream_Optimizations -@unnumberedsubsec No_Stream_Optimizations -@findex No_Stream_Optimizations +@node No_Stream_Optimizations,No_Streams,No_Standard_Storage_Pools,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-stream-optimizations}@anchor{19d} +@subsection No_Stream_Optimizations + + +@geindex No_Stream_Optimizations + [GNAT] This restriction affects the performance of stream operations on types -@code{String}, @code{Wide_String} and @code{Wide_Wide_String}. By default, the -compiler uses block reads and writes when manipulating @code{String} objects +@cite{String}, @cite{Wide_String} and @cite{Wide_Wide_String}. By default, the +compiler uses block reads and writes when manipulating @cite{String} objects due to their supperior performance. When this restriction is in effect, the compiler performs all IO operations on a per-character basis. -@node No_Streams -@unnumberedsubsec No_Streams -@findex No_Streams +@node No_Streams,No_Task_Allocators,No_Stream_Optimizations,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-streams}@anchor{19e} +@subsection No_Streams + + +@geindex No_Streams + [GNAT] This restriction ensures at compile/bind time that there are no stream objects created and no use of stream attributes. This restriction does not forbid dependences on the package -@code{Ada.Streams}. So it is permissible to with -@code{Ada.Streams} (or another package that does so itself) +@cite{Ada.Streams}. So it is permissible to with +@cite{Ada.Streams} (or another package that does so itself) as long as no actual stream objects are created and no stream attributes are used. @@ -10945,86 +11868,149 @@ To take maximum advantage of this space-saving optimization, any unit declaring a tagged type should be compiled with the restriction, though this is not required. -@node No_Task_Allocators -@unnumberedsubsec No_Task_Allocators -@findex No_Task_Allocators +@node No_Task_Allocators,No_Task_Attributes_Package,No_Streams,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-task-allocators}@anchor{19f} +@subsection No_Task_Allocators + + +@geindex No_Task_Allocators + [RM D.7] There are no allocators for task types or types containing task subcomponents. -@node No_Task_Attributes_Package -@unnumberedsubsec No_Task_Attributes_Package -@findex No_Task_Attributes_Package +@node No_Task_Attributes_Package,No_Task_Hierarchy,No_Task_Allocators,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-task-attributes-package}@anchor{1a0} +@subsection No_Task_Attributes_Package + + +@geindex No_Task_Attributes_Package + [GNAT] This restriction ensures at compile time that there are no implicit or -explicit dependencies on the package @code{Ada.Task_Attributes}. +explicit dependencies on the package @cite{Ada.Task_Attributes}. + +@geindex No_Task_Attributes -@findex No_Task_Attributes -The restriction @code{No_Task_Attributes} is recognized as a synonym -for @code{No_Task_Attributes_Package}. This is retained for historical +The restriction @cite{No_Task_Attributes} is recognized as a synonym +for @cite{No_Task_Attributes_Package}. This is retained for historical compatibility purposes (and a warning will be generated for its use if warnings on obsolescent features are activated). -@node No_Task_Hierarchy -@unnumberedsubsec No_Task_Hierarchy -@findex No_Task_Hierarchy +@node No_Task_Hierarchy,No_Task_Termination,No_Task_Attributes_Package,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-task-hierarchy}@anchor{1a1} +@subsection No_Task_Hierarchy + + +@geindex No_Task_Hierarchy + [RM D.7] All (non-environment) tasks depend directly on the environment task of the partition. -@node No_Task_Termination -@unnumberedsubsec No_Task_Termination -@findex No_Task_Termination +@node No_Task_Termination,No_Tasking,No_Task_Hierarchy,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-task-termination}@anchor{1a2} +@subsection No_Task_Termination + + +@geindex No_Task_Termination + [RM D.7] Tasks that terminate are erroneous. -@node No_Tasking -@unnumberedsubsec No_Tasking -@findex No_Tasking +@node No_Tasking,No_Terminate_Alternatives,No_Task_Termination,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-tasking}@anchor{1a3} +@subsection No_Tasking + + +@geindex No_Tasking + [GNAT] This restriction prevents the declaration of tasks or task types throughout the partition. It is similar in effect to the use of -@code{Max_Tasks => 0} except that violations are caught at compile time +@cite{Max_Tasks => 0} except that violations are caught at compile time and cause an error message to be output either by the compiler or binder. -@node No_Terminate_Alternatives -@unnumberedsubsec No_Terminate_Alternatives -@findex No_Terminate_Alternatives +@node No_Terminate_Alternatives,No_Unchecked_Access,No_Tasking,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-terminate-alternatives}@anchor{1a4} +@subsection No_Terminate_Alternatives + + +@geindex No_Terminate_Alternatives + [RM D.7] There are no selective accepts with terminate alternatives. -@node No_Unchecked_Access -@unnumberedsubsec No_Unchecked_Access -@findex No_Unchecked_Access +@node No_Unchecked_Access,No_Use_Of_Entity,No_Terminate_Alternatives,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-unchecked-access}@anchor{1a5} +@subsection No_Unchecked_Access + + +@geindex No_Unchecked_Access + [RM H.4] This restriction ensures at compile time that there are no occurrences of the Unchecked_Access attribute. -@node Simple_Barriers -@unnumberedsubsec Simple_Barriers -@findex Simple_Barriers +@node No_Use_Of_Entity,Simple_Barriers,No_Unchecked_Access,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-use-of-entity}@anchor{1a6} +@subsection No_Use_Of_Entity + + +@geindex No_Use_Of_Entity + +[GNAT] This restriction ensures at compile time that there are no references +to the entity given in the form + +@example +No_Use_Of_Entity => Name +@end example + +where @code{Name} is the fully qualified entity, for example + +@example +No_Use_Of_Entity => Ada.Text_IO.Put_Line +@end example + +@node Simple_Barriers,Static_Priorities,No_Use_Of_Entity,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions simple-barriers}@anchor{1a7} +@subsection Simple_Barriers + + +@geindex Simple_Barriers + [RM D.7] This restriction ensures at compile time that barriers in entry declarations for protected types are restricted to either static boolean expressions or references to simple boolean variables defined in the private part of the protected type. No other form of entry barriers is permitted. -@findex Boolean_Entry_Barriers -The restriction @code{Boolean_Entry_Barriers} is recognized as a -synonym for @code{Simple_Barriers}. This is retained for historical +@geindex Boolean_Entry_Barriers + +The restriction @cite{Boolean_Entry_Barriers} is recognized as a +synonym for @cite{Simple_Barriers}. This is retained for historical compatibility purposes (and a warning will be generated for its use if warnings on obsolescent features are activated). -@node Static_Priorities -@unnumberedsubsec Static_Priorities -@findex Static_Priorities +@node Static_Priorities,Static_Storage_Size,Simple_Barriers,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions static-priorities}@anchor{1a8} +@subsection Static_Priorities + + +@geindex Static_Priorities + [GNAT] This restriction ensures at compile time that all priority expressions are static, and that there are no dependences on the package -@code{Ada.Dynamic_Priorities}. +@cite{Ada.Dynamic_Priorities}. + +@node Static_Storage_Size,,Static_Priorities,Partition-Wide Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions static-storage-size}@anchor{1a9} +@subsection Static_Storage_Size + + +@geindex Static_Storage_Size -@node Static_Storage_Size -@unnumberedsubsec Static_Storage_Size -@findex Static_Storage_Size [GNAT] This restriction ensures at compile time that any expression appearing in a Storage_Size pragma or attribute definition clause is static. -@node Program Unit Level Restrictions +@node Program Unit Level Restrictions,,Partition-Wide Restrictions,Standard and Implementation Defined Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions program-unit-level-restrictions}@anchor{1aa}@anchor{gnat_rm/standard_and_implementation_defined_restrictions id3}@anchor{1ab} @section Program Unit Level Restrictions -@noindent + The second set of restriction identifiers does not require partition-wide consistency. The restriction may be enforced for a single @@ -11032,29 +12018,34 @@ compilation unit without any effect on any of the other compilation units in the partition. @menu -* No_Elaboration_Code:: -* No_Entry_Queue:: -* No_Implementation_Aspect_Specifications:: -* No_Implementation_Attributes:: -* No_Implementation_Identifiers:: -* No_Implementation_Pragmas:: -* No_Implementation_Restrictions:: -* No_Implementation_Units:: -* No_Implicit_Aliasing:: -* No_Obsolescent_Features:: -* No_Wide_Characters:: -* SPARK_05:: +* No_Elaboration_Code:: +* No_Entry_Queue:: +* No_Implementation_Aspect_Specifications:: +* No_Implementation_Attributes:: +* No_Implementation_Identifiers:: +* No_Implementation_Pragmas:: +* No_Implementation_Restrictions:: +* No_Implementation_Units:: +* No_Implicit_Aliasing:: +* No_Obsolescent_Features:: +* No_Wide_Characters:: +* SPARK_05:: + @end menu -@node No_Elaboration_Code -@unnumberedsubsec No_Elaboration_Code -@findex No_Elaboration_Code +@node No_Elaboration_Code,No_Entry_Queue,,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-elaboration-code}@anchor{1ac} +@subsection No_Elaboration_Code + + +@geindex No_Elaboration_Code + [GNAT] This restriction ensures at compile time that no elaboration code is generated. Note that this is not the same condition as is enforced -by pragma @code{Preelaborate}. There are cases in which pragma -@code{Preelaborate} still permits code to be generated (e.g.@: code +by pragma @cite{Preelaborate}. There are cases in which pragma +@cite{Preelaborate} still permits code to be generated (e.g., code to initialize a large array to all zeroes), and there are cases of units -which do not meet the requirements for pragma @code{Preelaborate}, +which do not meet the requirements for pragma @cite{Preelaborate}, but for which no elaboration code is generated. Generally, it is the case that preelaborable units will meet the restrictions, with the exception of large aggregates initialized with an others_clause, @@ -11065,7 +12056,7 @@ throughout a partition. In the case of aggregates with others, if the aggregate has a dynamic size, there is no way to eliminate the elaboration code (such dynamic -bounds would be incompatible with @code{Preelaborate} in any case). If +bounds would be incompatible with @cite{Preelaborate} in any case). If the bounds are static, then use of this restriction actually modifies the code choice of the compiler to avoid generating a loop, and instead generate the aggregate statically if possible, no matter how many times @@ -11077,11 +12068,10 @@ unlike most other restrictions, this is not a restriction on the source code, but a restriction on the generated object code. For example, if the source contains a declaration: -@smallexample - Val : constant Integer := X; -@end smallexample +@example +Val : constant Integer := X; +@end example -@noindent where X is not a static constant, it may be possible, depending on complex optimization circuitry, for the compiler to figure out the value of X at compile time, in which case this initialization @@ -11093,62 +12083,94 @@ Note that this the implementation of this restriction requires full code generation. If it is used in conjunction with "semantics only" checking, then some cases of violations may be missed. -@node No_Entry_Queue -@unnumberedsubsec No_Entry_Queue -@findex No_Entry_Queue +@node No_Entry_Queue,No_Implementation_Aspect_Specifications,No_Elaboration_Code,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-entry-queue}@anchor{1ad} +@subsection No_Entry_Queue + + +@geindex No_Entry_Queue + [GNAT] This restriction is a declaration that any protected entry compiled in the scope of the restriction has at most one task waiting on the entry at any one time, and so no queue is required. This restriction is not checked at compile time. A program execution is erroneous if an attempt is made to queue a second task on such an entry. -@node No_Implementation_Aspect_Specifications -@unnumberedsubsec No_Implementation_Aspect_Specifications -@findex No_Implementation_Aspect_Specifications +@node No_Implementation_Aspect_Specifications,No_Implementation_Attributes,No_Entry_Queue,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implementation-aspect-specifications}@anchor{1ae} +@subsection No_Implementation_Aspect_Specifications + + +@geindex No_Implementation_Aspect_Specifications + [RM 13.12.1] This restriction checks at compile time that no GNAT-defined aspects are present. With this restriction, the only aspects that can be used are those defined in the Ada Reference Manual. -@node No_Implementation_Attributes -@unnumberedsubsec No_Implementation_Attributes -@findex No_Implementation_Attributes +@node No_Implementation_Attributes,No_Implementation_Identifiers,No_Implementation_Aspect_Specifications,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implementation-attributes}@anchor{1af} +@subsection No_Implementation_Attributes + + +@geindex No_Implementation_Attributes + [RM 13.12.1] This restriction checks at compile time that no GNAT-defined attributes are present. With this restriction, the only attributes that can be used are those defined in the Ada Reference Manual. -@node No_Implementation_Identifiers -@unnumberedsubsec No_Implementation_Identifiers -@findex No_Implementation_Identifiers +@node No_Implementation_Identifiers,No_Implementation_Pragmas,No_Implementation_Attributes,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implementation-identifiers}@anchor{1b0} +@subsection No_Implementation_Identifiers + + +@geindex No_Implementation_Identifiers + [RM 13.12.1] This restriction checks at compile time that no implementation-defined identifiers (marked with pragma Implementation_Defined) occur within language-defined packages. -@node No_Implementation_Pragmas -@unnumberedsubsec No_Implementation_Pragmas -@findex No_Implementation_Pragmas +@node No_Implementation_Pragmas,No_Implementation_Restrictions,No_Implementation_Identifiers,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implementation-pragmas}@anchor{1b1} +@subsection No_Implementation_Pragmas + + +@geindex No_Implementation_Pragmas + [RM 13.12.1] This restriction checks at compile time that no GNAT-defined pragmas are present. With this restriction, the only pragmas that can be used are those defined in the Ada Reference Manual. -@node No_Implementation_Restrictions -@unnumberedsubsec No_Implementation_Restrictions -@findex No_Implementation_Restrictions +@node No_Implementation_Restrictions,No_Implementation_Units,No_Implementation_Pragmas,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implementation-restrictions}@anchor{1b2} +@subsection No_Implementation_Restrictions + + +@geindex No_Implementation_Restrictions + [GNAT] This restriction checks at compile time that no GNAT-defined restriction -identifiers (other than @code{No_Implementation_Restrictions} itself) +identifiers (other than @cite{No_Implementation_Restrictions} itself) are present. With this restriction, the only other restriction identifiers that can be used are those defined in the Ada Reference Manual. -@node No_Implementation_Units -@unnumberedsubsec No_Implementation_Units -@findex No_Implementation_Units +@node No_Implementation_Units,No_Implicit_Aliasing,No_Implementation_Restrictions,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implementation-units}@anchor{1b3} +@subsection No_Implementation_Units + + +@geindex No_Implementation_Units + [RM 13.12.1] This restriction checks at compile time that there is no mention in the context clause of any implementation-defined descendants of packages Ada, Interfaces, or System. -@node No_Implicit_Aliasing -@unnumberedsubsec No_Implicit_Aliasing -@findex No_Implicit_Aliasing +@node No_Implicit_Aliasing,No_Obsolescent_Features,No_Implementation_Units,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-implicit-aliasing}@anchor{1b4} +@subsection No_Implicit_Aliasing + + +@geindex No_Implicit_Aliasing + [GNAT] This restriction, which is not required to be partition-wide consistent, requires an explicit aliased keyword for an object to which 'Access, 'Unchecked_Access, or 'Address is applied, and forbids entirely the use of @@ -11157,39 +12179,52 @@ Unrestricted_Access is forbidden is that it would require the prefix to be aliased, and in such cases, it can always be replaced by the standard attribute Unchecked_Access which is preferable. -@node No_Obsolescent_Features -@unnumberedsubsec No_Obsolescent_Features -@findex No_Obsolescent_Features +@node No_Obsolescent_Features,No_Wide_Characters,No_Implicit_Aliasing,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-obsolescent-features}@anchor{1b5} +@subsection No_Obsolescent_Features + + +@geindex No_Obsolescent_Features + [RM 13.12.1] This restriction checks at compile time that no obsolescent features are used, as defined in Annex J of the Ada Reference Manual. -@node No_Wide_Characters -@unnumberedsubsec No_Wide_Characters -@findex No_Wide_Characters +@node No_Wide_Characters,SPARK_05,No_Obsolescent_Features,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions no-wide-characters}@anchor{1b6} +@subsection No_Wide_Characters + + +@geindex No_Wide_Characters + [GNAT] This restriction ensures at compile time that no uses of the types -@code{Wide_Character} or @code{Wide_String} or corresponding wide +@cite{Wide_Character} or @cite{Wide_String} or corresponding wide wide types appear, and that no wide or wide wide string or character literals appear in the program (that is literals representing characters not in -type @code{Character}). +type @cite{Character}). + +@node SPARK_05,,No_Wide_Characters,Program Unit Level Restrictions +@anchor{gnat_rm/standard_and_implementation_defined_restrictions spark-05}@anchor{1b7} +@subsection SPARK_05 + + +@geindex SPARK_05 -@node SPARK_05 -@unnumberedsubsec SPARK_05 -@findex SPARK_05 [GNAT] This restriction checks at compile time that some constructs forbidden in SPARK 2005 are not present. Error messages related to SPARK restriction have the form: -@smallexample +@example violation of restriction "SPARK_05" at <source-location> <error message> -@end smallexample +@end example + +@geindex SPARK -@findex SPARK -The restriction @code{SPARK} is recognized as a -synonym for @code{SPARK_05}. This is retained for historical +The restriction @cite{SPARK} is recognized as a +synonym for @cite{SPARK_05}. This is retained for historical compatibility purposes (and an unconditional warning will be generated -for its use, advising replacement by @code{SPARK}). +for its use, advising replacement by @cite{SPARK}). This is not a replacement for the semantic checks performed by the SPARK Examiner tool, as the compiler currently only deals with code, @@ -11199,7 +12234,7 @@ cases of constructs forbidden by SPARK 2005. Thus it may well be the case that code which passes the compiler with the SPARK restriction is rejected by the SPARK Examiner, e.g. due to the different visibility rules of the Examiner based on SPARK 2005 -@code{inherit} annotations. +@cite{inherit} annotations. This restriction can be useful in providing an initial filter for code developed using SPARK 2005, or in examining legacy code to see how far @@ -11207,254 +12242,633 @@ it is from meeting SPARK restrictions. The list below summarizes the checks that are performed when this restriction is in force: -@itemize @bullet -@item No block statements -@item No case statements with only an others clause -@item Exit statements in loops must respect the SPARK 2005 language restrictions -@item No goto statements -@item Return can only appear as last statement in function -@item Function must have return statement -@item Loop parameter specification must include subtype mark -@item Prefix of expanded name cannot be a loop statement -@item Abstract subprogram not allowed -@item User-defined operators not allowed -@item Access type parameters not allowed -@item Default expressions for parameters not allowed -@item Default expressions for record fields not allowed -@item No tasking constructs allowed -@item Label needed at end of subprograms and packages -@item No mixing of positional and named parameter association -@item No access types as result type -@item No unconstrained arrays as result types -@item No null procedures -@item Initial and later declarations must be in correct order (declaration can't come after body) -@item No attributes on private types if full declaration not visible -@item No package declaration within package specification -@item No controlled types -@item No discriminant types -@item No overloading -@item Selector name cannot be operator symbol (i.e. operator symbol cannot be prefixed) -@item Access attribute not allowed -@item Allocator not allowed -@item Result of catenation must be String -@item Operands of catenation must be string literal, static char or another catenation -@item No conditional expressions -@item No explicit dereference -@item Quantified expression not allowed -@item Slicing not allowed -@item No exception renaming -@item No generic renaming -@item No object renaming -@item No use clause -@item Aggregates must be qualified -@item Non-static choice in array aggregates not allowed -@item The only view conversions which are allowed as in-out parameters are conversions of a tagged type to an ancestor type -@item No mixing of positional and named association in aggregate, no multi choice -@item AND, OR and XOR for arrays only allowed when operands have same static bounds -@item Fixed point operands to * or / must be qualified or converted -@item Comparison operators not allowed for Booleans or arrays (except strings) -@item Equality not allowed for arrays with non-matching static bounds (except strings) -@item Conversion / qualification not allowed for arrays with non-matching static bounds -@item Subprogram declaration only allowed in package spec (unless followed by import) -@item Access types not allowed -@item Incomplete type declaration not allowed -@item Object and subtype declarations must respect SPARK restrictions -@item Digits or delta constraint not allowed -@item Decimal fixed point type not allowed -@item Aliasing of objects not allowed -@item Modular type modulus must be power of 2 -@item Base not allowed on subtype mark -@item Unary operators not allowed on modular types (except not) -@item Untagged record cannot be null -@item No class-wide operations -@item Initialization expressions must respect SPARK restrictions -@item Non-static ranges not allowed except in iteration schemes -@item String subtypes must have lower bound of 1 -@item Subtype of Boolean cannot have constraint -@item At most one tagged type or extension per package -@item Interface is not allowed -@item Character literal cannot be prefixed (selector name cannot be character literal) -@item Record aggregate cannot contain 'others' -@item Component association in record aggregate must contain a single choice -@item Ancestor part cannot be a type mark -@item Attributes 'Image, 'Width and 'Value not allowed -@item Functions may not update globals -@item Subprograms may not contain direct calls to themselves (prevents recursion within unit) -@item Call to subprogram not allowed in same unit before body has been seen (prevents recursion within unit) + + +@itemize * + +@item +No block statements + +@item +No case statements with only an others clause + +@item +Exit statements in loops must respect the SPARK 2005 language restrictions + +@item +No goto statements + +@item +Return can only appear as last statement in function + +@item +Function must have return statement + +@item +Loop parameter specification must include subtype mark + +@item +Prefix of expanded name cannot be a loop statement + +@item +Abstract subprogram not allowed + +@item +User-defined operators not allowed + +@item +Access type parameters not allowed + +@item +Default expressions for parameters not allowed + +@item +Default expressions for record fields not allowed + +@item +No tasking constructs allowed + +@item +Label needed at end of subprograms and packages + +@item +No mixing of positional and named parameter association + +@item +No access types as result type + +@item +No unconstrained arrays as result types + +@item +No null procedures + +@item +Initial and later declarations must be in correct order (declaration can't come after body) + +@item +No attributes on private types if full declaration not visible + +@item +No package declaration within package specification + +@item +No controlled types + +@item +No discriminant types + +@item +No overloading + +@item +Selector name cannot be operator symbol (i.e. operator symbol cannot be prefixed) + +@item +Access attribute not allowed + +@item +Allocator not allowed + +@item +Result of catenation must be String + +@item +Operands of catenation must be string literal, static char or another catenation + +@item +No conditional expressions + +@item +No explicit dereference + +@item +Quantified expression not allowed + +@item +Slicing not allowed + +@item +No exception renaming + +@item +No generic renaming + +@item +No object renaming + +@item +No use clause + +@item +Aggregates must be qualified + +@item +Non-static choice in array aggregates not allowed + +@item +The only view conversions which are allowed as in-out parameters are conversions of a tagged type to an ancestor type + +@item +No mixing of positional and named association in aggregate, no multi choice + +@item +AND, OR and XOR for arrays only allowed when operands have same static bounds + +@item +Fixed point operands to * or / must be qualified or converted + +@item +Comparison operators not allowed for Booleans or arrays (except strings) + +@item +Equality not allowed for arrays with non-matching static bounds (except strings) + +@item +Conversion / qualification not allowed for arrays with non-matching static bounds + +@item +Subprogram declaration only allowed in package spec (unless followed by import) + +@item +Access types not allowed + +@item +Incomplete type declaration not allowed + +@item +Object and subtype declarations must respect SPARK restrictions + +@item +Digits or delta constraint not allowed + +@item +Decimal fixed point type not allowed + +@item +Aliasing of objects not allowed + +@item +Modular type modulus must be power of 2 + +@item +Base not allowed on subtype mark + +@item +Unary operators not allowed on modular types (except not) + +@item +Untagged record cannot be null + +@item +No class-wide operations + +@item +Initialization expressions must respect SPARK restrictions + +@item +Non-static ranges not allowed except in iteration schemes + +@item +String subtypes must have lower bound of 1 + +@item +Subtype of Boolean cannot have constraint + +@item +At most one tagged type or extension per package + +@item +Interface is not allowed + +@item +Character literal cannot be prefixed (selector name cannot be character literal) + +@item +Record aggregate cannot contain 'others' + +@item +Component association in record aggregate must contain a single choice + +@item +Ancestor part cannot be a type mark + +@item +Attributes 'Image, 'Width and 'Value not allowed + +@item +Functions may not update globals + +@item +Subprograms may not contain direct calls to themselves (prevents recursion within unit) + +@item +Call to subprogram not allowed in same unit before body has been seen (prevents recursion within unit) @end itemize The following restrictions are enforced, but note that they are actually more strict that the latest SPARK 2005 language definition: -@itemize @bullet -@item No derived types other than tagged type extensions -@item Subtype of unconstrained array must have constraint + +@itemize * + +@item +No derived types other than tagged type extensions + +@item +Subtype of unconstrained array must have constraint @end itemize This list summarises the main SPARK 2005 language rules that are not currently checked by the SPARK_05 restriction: -@itemize @bullet -@item SPARK annotations are treated as comments so are not checked at all -@item Based real literals not allowed -@item Objects cannot be initialized at declaration by calls to user-defined functions -@item Objects cannot be initialized at declaration by assignments from variables -@item Objects cannot be initialized at declaration by assignments from indexed/selected components -@item Ranges shall not be null -@item A fixed point delta expression must be a simple expression -@item Restrictions on where renaming declarations may be placed -@item Externals of mode 'out' cannot be referenced -@item Externals of mode 'in' cannot be updated -@item Loop with no iteration scheme or exits only allowed as last statement in main program or task -@item Subprogram cannot have parent unit name -@item SPARK 2005 inherited subprogram must be prefixed with overriding -@item External variables (or functions that reference them) may not be passed as actual parameters -@item Globals must be explicitly mentioned in contract -@item Deferred constants cannot be completed by pragma Import -@item Package initialization cannot read/write variables from other packages -@item Prefix not allowed for entities that are directly visible -@item Identifier declaration can't override inherited package name -@item Cannot use Standard or other predefined packages as identifiers -@item After renaming, cannot use the original name -@item Subprograms can only be renamed to remove package prefix -@item Pragma import must be immediately after entity it names -@item No mutual recursion between multiple units (this can be checked with gnatcheck) + +@itemize * + +@item +SPARK annotations are treated as comments so are not checked at all + +@item +Based real literals not allowed + +@item +Objects cannot be initialized at declaration by calls to user-defined functions + +@item +Objects cannot be initialized at declaration by assignments from variables + +@item +Objects cannot be initialized at declaration by assignments from indexed/selected components + +@item +Ranges shall not be null + +@item +A fixed point delta expression must be a simple expression + +@item +Restrictions on where renaming declarations may be placed + +@item +Externals of mode 'out' cannot be referenced + +@item +Externals of mode 'in' cannot be updated + +@item +Loop with no iteration scheme or exits only allowed as last statement in main program or task + +@item +Subprogram cannot have parent unit name + +@item +SPARK 2005 inherited subprogram must be prefixed with overriding + +@item +External variables (or functions that reference them) may not be passed as actual parameters + +@item +Globals must be explicitly mentioned in contract + +@item +Deferred constants cannot be completed by pragma Import + +@item +Package initialization cannot read/write variables from other packages + +@item +Prefix not allowed for entities that are directly visible + +@item +Identifier declaration can't override inherited package name + +@item +Cannot use Standard or other predefined packages as identifiers + +@item +After renaming, cannot use the original name + +@item +Subprograms can only be renamed to remove package prefix + +@item +Pragma import must be immediately after entity it names + +@item +No mutual recursion between multiple units (this can be checked with gnatcheck) @end itemize Note that if a unit is compiled in Ada 95 mode with the SPARK restriction, violations will be reported for constructs forbidden in SPARK 95, instead of SPARK 2005. -@c ------------------------ -@node Implementation Advice +@node Implementation Advice,Implementation Defined Characteristics,Standard and Implementation Defined Restrictions,Top +@anchor{gnat_rm/implementation_advice doc}@anchor{1b8}@anchor{gnat_rm/implementation_advice implementation-advice}@anchor{a}@anchor{gnat_rm/implementation_advice id1}@anchor{1b9} @chapter Implementation Advice -@noindent + + The main text of the Ada Reference Manual describes the required behavior of all Ada compilers, and the GNAT compiler conforms to these requirements. In addition, there are sections throughout the Ada Reference Manual headed -by the phrase ``Implementation advice''. These sections are not normative, +by the phrase 'Implementation advice'. These sections are not normative, i.e., they do not specify requirements that all compilers must -follow. Rather they provide advice on generally desirable behavior. You -may wonder why they are not requirements. The most typical answer is -that they describe behavior that seems generally desirable, but cannot -be provided on all systems, or which may be undesirable on some systems. - -As far as practical, GNAT follows the implementation advice sections in -the Ada Reference Manual. This chapter contains a table giving the -reference manual section number, paragraph number and several keywords -for each advice. Each entry consists of the text of the advice followed -by the GNAT interpretation of this advice. Most often, this simply says -``followed'', which means that GNAT follows the advice. However, in a +follow. Rather they provide advice on generally desirable behavior. +They are not requirements, because they describe behavior that cannot +be provided on all systems, or may be undesirable on some systems. + +As far as practical, GNAT follows the implementation advice in +the Ada Reference Manual. Each such RM section corresponds to a section +in this chapter whose title specifies the +RM section number and paragraph number and the subject of +the advice. The contents of each section consists of the RM text within +quotation marks, +followed by the GNAT interpretation of the advice. Most often, this simply says +'followed', which means that GNAT follows the advice. However, in a number of cases, GNAT deliberately deviates from this advice, in which case the text describes what GNAT does and why. -@cindex Error detection -@unnumberedsec 1.1.3(20): Error Detection -@sp 1 -@cartouche -If an implementation detects the use of an unsupported Specialized Needs -Annex feature at run time, it should raise @code{Program_Error} if -feasible. -@end cartouche +@geindex Error detection + +@menu +* RM 1.1.3(20); Error Detection: RM 1 1 3 20 Error Detection. +* RM 1.1.3(31); Child Units: RM 1 1 3 31 Child Units. +* RM 1.1.5(12); Bounded Errors: RM 1 1 5 12 Bounded Errors. +* RM 2.8(16); Pragmas: RM 2 8 16 Pragmas. +* RM 2.8(17-19); Pragmas: RM 2 8 17-19 Pragmas. +* RM 3.5.2(5); Alternative Character Sets: RM 3 5 2 5 Alternative Character Sets. +* RM 3.5.4(28); Integer Types: RM 3 5 4 28 Integer Types. +* RM 3.5.4(29); Integer Types: RM 3 5 4 29 Integer Types. +* RM 3.5.5(8); Enumeration Values: RM 3 5 5 8 Enumeration Values. +* RM 3.5.7(17); Float Types: RM 3 5 7 17 Float Types. +* RM 3.6.2(11); Multidimensional Arrays: RM 3 6 2 11 Multidimensional Arrays. +* RM 9.6(30-31); Duration'Small: RM 9 6 30-31 Duration'Small. +* RM 10.2.1(12); Consistent Representation: RM 10 2 1 12 Consistent Representation. +* RM 11.4.1(19); Exception Information: RM 11 4 1 19 Exception Information. +* RM 11.5(28); Suppression of Checks: RM 11 5 28 Suppression of Checks. +* RM 13.1 (21-24); Representation Clauses: RM 13 1 21-24 Representation Clauses. +* RM 13.2(6-8); Packed Types: RM 13 2 6-8 Packed Types. +* RM 13.3(14-19); Address Clauses: RM 13 3 14-19 Address Clauses. +* RM 13.3(29-35); Alignment Clauses: RM 13 3 29-35 Alignment Clauses. +* RM 13.3(42-43); Size Clauses: RM 13 3 42-43 Size Clauses. +* RM 13.3(50-56); Size Clauses: RM 13 3 50-56 Size Clauses. +* RM 13.3(71-73); Component Size Clauses: RM 13 3 71-73 Component Size Clauses. +* RM 13.4(9-10); Enumeration Representation Clauses: RM 13 4 9-10 Enumeration Representation Clauses. +* RM 13.5.1(17-22); Record Representation Clauses: RM 13 5 1 17-22 Record Representation Clauses. +* RM 13.5.2(5); Storage Place Attributes: RM 13 5 2 5 Storage Place Attributes. +* RM 13.5.3(7-8); Bit Ordering: RM 13 5 3 7-8 Bit Ordering. +* RM 13.7(37); Address as Private: RM 13 7 37 Address as Private. +* RM 13.7.1(16); Address Operations: RM 13 7 1 16 Address Operations. +* RM 13.9(14-17); Unchecked Conversion: RM 13 9 14-17 Unchecked Conversion. +* RM 13.11(23-25); Implicit Heap Usage: RM 13 11 23-25 Implicit Heap Usage. +* RM 13.11.2(17); Unchecked Deallocation: RM 13 11 2 17 Unchecked Deallocation. +* RM 13.13.2(17); Stream Oriented Attributes: RM 13 13 2 17 Stream Oriented Attributes. +* RM A.1(52); Names of Predefined Numeric Types: RM A 1 52 Names of Predefined Numeric Types. +* RM A.3.2(49); Ada.Characters.Handling: RM A 3 2 49 Ada Characters Handling. +* RM A.4.4(106); Bounded-Length String Handling: RM A 4 4 106 Bounded-Length String Handling. +* RM A.5.2(46-47); Random Number Generation: RM A 5 2 46-47 Random Number Generation. +* RM A.10.7(23); Get_Immediate: RM A 10 7 23 Get_Immediate. +* RM B.1(39-41); Pragma Export: RM B 1 39-41 Pragma Export. +* RM B.2(12-13); Package Interfaces: RM B 2 12-13 Package Interfaces. +* RM B.3(63-71); Interfacing with C: RM B 3 63-71 Interfacing with C. +* RM B.4(95-98); Interfacing with COBOL: RM B 4 95-98 Interfacing with COBOL. +* RM B.5(22-26); Interfacing with Fortran: RM B 5 22-26 Interfacing with Fortran. +* RM C.1(3-5); Access to Machine Operations: RM C 1 3-5 Access to Machine Operations. +* RM C.1(10-16); Access to Machine Operations: RM C 1 10-16 Access to Machine Operations. +* RM C.3(28); Interrupt Support: RM C 3 28 Interrupt Support. +* RM C.3.1(20-21); Protected Procedure Handlers: RM C 3 1 20-21 Protected Procedure Handlers. +* RM C.3.2(25); Package Interrupts: RM C 3 2 25 Package Interrupts. +* RM C.4(14); Pre-elaboration Requirements: RM C 4 14 Pre-elaboration Requirements. +* RM C.5(8); Pragma Discard_Names: RM C 5 8 Pragma Discard_Names. +* RM C.7.2(30); The Package Task_Attributes: RM C 7 2 30 The Package Task_Attributes. +* RM D.3(17); Locking Policies: RM D 3 17 Locking Policies. +* RM D.4(16); Entry Queuing Policies: RM D 4 16 Entry Queuing Policies. +* RM D.6(9-10); Preemptive Abort: RM D 6 9-10 Preemptive Abort. +* RM D.7(21); Tasking Restrictions: RM D 7 21 Tasking Restrictions. +* RM D.8(47-49); Monotonic Time: RM D 8 47-49 Monotonic Time. +* RM E.5(28-29); Partition Communication Subsystem: RM E 5 28-29 Partition Communication Subsystem. +* RM F(7); COBOL Support: RM F 7 COBOL Support. +* RM F.1(2); Decimal Radix Support: RM F 1 2 Decimal Radix Support. +* RM G; Numerics: RM G Numerics. +* RM G.1.1(56-58); Complex Types: RM G 1 1 56-58 Complex Types. +* RM G.1.2(49); Complex Elementary Functions: RM G 1 2 49 Complex Elementary Functions. +* RM G.2.4(19); Accuracy Requirements: RM G 2 4 19 Accuracy Requirements. +* RM G.2.6(15); Complex Arithmetic Accuracy: RM G 2 6 15 Complex Arithmetic Accuracy. +* RM H.6(15/2); Pragma Partition_Elaboration_Policy: RM H 6 15/2 Pragma Partition_Elaboration_Policy. + +@end menu + +@node RM 1 1 3 20 Error Detection,RM 1 1 3 31 Child Units,,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-1-1-3-20-error-detection}@anchor{1ba} +@section RM 1.1.3(20): Error Detection + + +@quotation + +"If an implementation detects the use of an unsupported Specialized Needs +Annex feature at run time, it should raise @cite{Program_Error} if +feasible." +@end quotation + Not relevant. All specialized needs annex features are either supported, or diagnosed at compile time. -@cindex Child Units -@unnumberedsec 1.1.3(31): Child Units -@sp 1 -@cartouche -If an implementation wishes to provide implementation-defined +@geindex Child Units + +@node RM 1 1 3 31 Child Units,RM 1 1 5 12 Bounded Errors,RM 1 1 3 20 Error Detection,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-1-1-3-31-child-units}@anchor{1bb} +@section RM 1.1.3(31): Child Units + + +@quotation + +"If an implementation wishes to provide implementation-defined extensions to the functionality of a language-defined library unit, it -should normally do so by adding children to the library unit. -@end cartouche +should normally do so by adding children to the library unit." +@end quotation + Followed. -@cindex Bounded errors -@unnumberedsec 1.1.5(12): Bounded Errors -@sp 1 -@cartouche -If an implementation detects a bounded error or erroneous -execution, it should raise @code{Program_Error}. -@end cartouche +@geindex Bounded errors + +@node RM 1 1 5 12 Bounded Errors,RM 2 8 16 Pragmas,RM 1 1 3 31 Child Units,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-1-1-5-12-bounded-errors}@anchor{1bc} +@section RM 1.1.5(12): Bounded Errors + + +@quotation + +"If an implementation detects a bounded error or erroneous +execution, it should raise @cite{Program_Error}." +@end quotation + Followed in all cases in which the implementation detects a bounded error or erroneous execution. Not all such situations are detected at runtime. -@cindex Pragmas -@unnumberedsec 2.8(16): Pragmas -@sp 1 -@cartouche -Normally, implementation-defined pragmas should have no semantic effect +@geindex Pragmas + +@node RM 2 8 16 Pragmas,RM 2 8 17-19 Pragmas,RM 1 1 5 12 Bounded Errors,Implementation Advice +@anchor{gnat_rm/implementation_advice id2}@anchor{1bd}@anchor{gnat_rm/implementation_advice rm-2-8-16-pragmas}@anchor{1be} +@section RM 2.8(16): Pragmas + + +@quotation + +"Normally, implementation-defined pragmas should have no semantic effect for error-free programs; that is, if the implementation-defined pragmas are removed from a working program, the program should still be legal, -and should still have the same semantics. -@end cartouche +and should still have the same semantics." +@end quotation + The following implementation defined pragmas are exceptions to this rule: -@table @code -@item Abort_Defer + +@multitable {xxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxx} +@headitem + +Pragma + +@tab + +Explanation + +@item + +@emph{Abort_Defer} + +@tab + Affects semantics -@item Ada_83 + +@item + +@emph{Ada_83} + +@tab + Affects legality -@item Assert + +@item + +@emph{Assert} + +@tab + Affects semantics -@item CPP_Class + +@item + +@emph{CPP_Class} + +@tab + Affects semantics -@item CPP_Constructor + +@item + +@emph{CPP_Constructor} + +@tab + Affects semantics -@item Debug + +@item + +@emph{Debug} + +@tab + Affects semantics -@item Interface_Name + +@item + +@emph{Interface_Name} + +@tab + Affects semantics -@item Machine_Attribute + +@item + +@emph{Machine_Attribute} + +@tab + Affects semantics -@item Unimplemented_Unit + +@item + +@emph{Unimplemented_Unit} + +@tab + Affects legality -@item Unchecked_Union + +@item + +@emph{Unchecked_Union} + +@tab + Affects semantics -@end table -@noindent +@end multitable + + In each of the above cases, it is essential to the purpose of the pragma -that this advice not be followed. For details see the separate section -on implementation defined pragmas. +that this advice not be followed. For details see +@ref{7,,Implementation Defined Pragmas}. -@unnumberedsec 2.8(17-19): Pragmas -@sp 1 -@cartouche -Normally, an implementation should not define pragmas that can +@node RM 2 8 17-19 Pragmas,RM 3 5 2 5 Alternative Character Sets,RM 2 8 16 Pragmas,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-2-8-17-19-pragmas}@anchor{1bf} +@section RM 2.8(17-19): Pragmas + + +@quotation + +"Normally, an implementation should not define pragmas that can make an illegal program legal, except as follows: -@end cartouche -@sp 1 -@cartouche -A pragma used to complete a declaration, such as a pragma @code{Import}; -@end cartouche -@sp 1 -@cartouche + + +@itemize * + +@item +A pragma used to complete a declaration, such as a pragma @cite{Import}; + +@item A pragma used to configure the environment by adding, removing, or -replacing @code{library_items}. -@end cartouche -See response to paragraph 16 of this same section. - -@cindex Character Sets -@cindex Alternative Character Sets -@unnumberedsec 3.5.2(5): Alternative Character Sets -@sp 1 -@cartouche -If an implementation supports a mode with alternative interpretations -for @code{Character} and @code{Wide_Character}, the set of graphic -characters of @code{Character} should nevertheless remain a proper -subset of the set of graphic characters of @code{Wide_Character}. Any -character set ``localizations'' should be reflected in the results of +replacing @cite{library_items}." +@end itemize +@end quotation + +See @ref{1be,,RM 2.8(16); Pragmas}. + +@geindex Character Sets + +@geindex Alternative Character Sets + +@node RM 3 5 2 5 Alternative Character Sets,RM 3 5 4 28 Integer Types,RM 2 8 17-19 Pragmas,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-3-5-2-5-alternative-character-sets}@anchor{1c0} +@section RM 3.5.2(5): Alternative Character Sets + + +@quotation + +"If an implementation supports a mode with alternative interpretations +for @cite{Character} and @cite{Wide_Character}, the set of graphic +characters of @cite{Character} should nevertheless remain a proper +subset of the set of graphic characters of @cite{Wide_Character}. Any +character set 'localizations' should be reflected in the results of the subprograms defined in the language-defined package -@code{Characters.Handling} (see A.3) available in such a mode. In a mode with -an alternative interpretation of @code{Character}, the implementation should +@cite{Characters.Handling} (see A.3) available in such a mode. In a mode with +an alternative interpretation of @cite{Character}, the implementation should also support a corresponding change in what is a legal -@code{identifier_letter}. -@end cartouche +@cite{identifier_letter}." +@end quotation + Not all wide character modes follow this advice, in particular the JIS and IEC modes reflect standard usage in Japan, and in these encoding, the upper half of the Latin-1 set is not part of the wide-character @@ -11462,208 +12876,271 @@ subset, since the most significant bit is used for wide character encoding. However, this only applies to the external forms. Internally there is no such restriction. -@cindex Integer types -@unnumberedsec 3.5.4(28): Integer Types +@geindex Integer types + +@node RM 3 5 4 28 Integer Types,RM 3 5 4 29 Integer Types,RM 3 5 2 5 Alternative Character Sets,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-3-5-4-28-integer-types}@anchor{1c1} +@section RM 3.5.4(28): Integer Types + -@sp 1 -@cartouche -An implementation should support @code{Long_Integer} in addition to -@code{Integer} if the target machine supports 32-bit (or longer) +@quotation + +"An implementation should support @cite{Long_Integer} in addition to +@cite{Integer} if the target machine supports 32-bit (or longer) arithmetic. No other named integer subtypes are recommended for package -@code{Standard}. Instead, appropriate named integer subtypes should be -provided in the library package @code{Interfaces} (see B.2). -@end cartouche -@code{Long_Integer} is supported. Other standard integer types are supported +@cite{Standard}. Instead, appropriate named integer subtypes should be +provided in the library package @cite{Interfaces} (see B.2)." +@end quotation + +@cite{Long_Integer} is supported. Other standard integer types are supported so this advice is not fully followed. These types are supported for convenient interface to C, and so that all hardware types of the machine are easily available. -@unnumberedsec 3.5.4(29): Integer Types -@sp 1 -@cartouche -An implementation for a two's complement machine should support +@node RM 3 5 4 29 Integer Types,RM 3 5 5 8 Enumeration Values,RM 3 5 4 28 Integer Types,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-3-5-4-29-integer-types}@anchor{1c2} +@section RM 3.5.4(29): Integer Types + + +@quotation + +"An implementation for a two's complement machine should support modular types with a binary modulus up to @code{System.Max_Int*2+2}. An -implementation should support a non-binary modules up to @code{Integer'Last}. -@end cartouche +implementation should support a non-binary modules up to @cite{Integer'Last}." +@end quotation + Followed. -@cindex Enumeration values -@unnumberedsec 3.5.5(8): Enumeration Values -@sp 1 -@cartouche -For the evaluation of a call on @code{@var{S}'Pos} for an enumeration +@geindex Enumeration values + +@node RM 3 5 5 8 Enumeration Values,RM 3 5 7 17 Float Types,RM 3 5 4 29 Integer Types,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-3-5-5-8-enumeration-values}@anchor{1c3} +@section RM 3.5.5(8): Enumeration Values + + +@quotation + +"For the evaluation of a call on @code{S'Pos} for an enumeration subtype, if the value of the operand does not correspond to the internal code for any enumeration literal of its type (perhaps due to an un-initialized variable), then the implementation should raise -@code{Program_Error}. This is particularly important for enumeration +@cite{Program_Error}. This is particularly important for enumeration types with noncontiguous internal codes specified by an -enumeration_representation_clause. -@end cartouche +enumeration_representation_clause." +@end quotation + Followed. -@cindex Float types -@unnumberedsec 3.5.7(17): Float Types -@sp 1 -@cartouche -An implementation should support @code{Long_Float} in addition to -@code{Float} if the target machine supports 11 or more digits of +@geindex Float types + +@node RM 3 5 7 17 Float Types,RM 3 6 2 11 Multidimensional Arrays,RM 3 5 5 8 Enumeration Values,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-3-5-7-17-float-types}@anchor{1c4} +@section RM 3.5.7(17): Float Types + + +@quotation + +"An implementation should support @cite{Long_Float} in addition to +@cite{Float} if the target machine supports 11 or more digits of precision. No other named floating point subtypes are recommended for -package @code{Standard}. Instead, appropriate named floating point subtypes -should be provided in the library package @code{Interfaces} (see B.2). -@end cartouche -@code{Short_Float} and @code{Long_Long_Float} are also provided. The +package @cite{Standard}. Instead, appropriate named floating point subtypes +should be provided in the library package @cite{Interfaces} (see B.2)." +@end quotation + +@cite{Short_Float} and @cite{Long_Long_Float} are also provided. The former provides improved compatibility with other implementations supporting this type. The latter corresponds to the highest precision floating-point type supported by the hardware. On most machines, this -will be the same as @code{Long_Float}, but on some machines, it will +will be the same as @cite{Long_Float}, but on some machines, it will correspond to the IEEE extended form. The notable case is all ia32 -(x86) implementations, where @code{Long_Long_Float} corresponds to +(x86) implementations, where @cite{Long_Long_Float} corresponds to the 80-bit extended precision format supported in hardware on this processor. Note that the 128-bit format on SPARC is not supported, since this is a software rather than a hardware format. -@cindex Multidimensional arrays -@cindex Arrays, multidimensional -@unnumberedsec 3.6.2(11): Multidimensional Arrays -@sp 1 -@cartouche -An implementation should normally represent multidimensional arrays in +@geindex Multidimensional arrays + +@geindex Arrays +@geindex multidimensional + +@node RM 3 6 2 11 Multidimensional Arrays,RM 9 6 30-31 Duration'Small,RM 3 5 7 17 Float Types,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-3-6-2-11-multidimensional-arrays}@anchor{1c5} +@section RM 3.6.2(11): Multidimensional Arrays + + +@quotation + +"An implementation should normally represent multidimensional arrays in row-major order, consistent with the notation used for multidimensional -array aggregates (see 4.3.3). However, if a pragma @code{Convention} -(@code{Fortran}, @dots{}) applies to a multidimensional array type, then -column-major order should be used instead (see B.5, ``Interfacing with -Fortran''). -@end cartouche +array aggregates (see 4.3.3). However, if a pragma @cite{Convention} +(@cite{Fortran}, ...) applies to a multidimensional array type, then +column-major order should be used instead (see B.5, @cite{Interfacing with Fortran})." +@end quotation + Followed. -@findex Duration'Small -@unnumberedsec 9.6(30-31): Duration'Small -@sp 1 -@cartouche -Whenever possible in an implementation, the value of @code{Duration'Small} -should be no greater than 100 microseconds. -@end cartouche -Followed. (@code{Duration'Small} = 10**(@minus{}9)). - -@sp 1 -@cartouche -The time base for @code{delay_relative_statements} should be monotonic; -it need not be the same time base as used for @code{Calendar.Clock}. -@end cartouche +@geindex Duration'Small + +@node RM 9 6 30-31 Duration'Small,RM 10 2 1 12 Consistent Representation,RM 3 6 2 11 Multidimensional Arrays,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-9-6-30-31-duration-small}@anchor{1c6} +@section RM 9.6(30-31): Duration'Small + + +@quotation + +"Whenever possible in an implementation, the value of @cite{Duration'Small} +should be no greater than 100 microseconds." +@end quotation + +Followed. (@cite{Duration'Small} = 10**(-9)). + +@quotation + +"The time base for @cite{delay_relative_statements} should be monotonic; +it need not be the same time base as used for @cite{Calendar.Clock}." +@end quotation + Followed. -@unnumberedsec 10.2.1(12): Consistent Representation -@sp 1 -@cartouche -In an implementation, a type declared in a pre-elaborated package should +@node RM 10 2 1 12 Consistent Representation,RM 11 4 1 19 Exception Information,RM 9 6 30-31 Duration'Small,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-10-2-1-12-consistent-representation}@anchor{1c7} +@section RM 10.2.1(12): Consistent Representation + + +@quotation + +"In an implementation, a type declared in a pre-elaborated package should have the same representation in every elaboration of a given version of the package, whether the elaborations occur in distinct executions of the same program, or in executions of distinct programs or partitions -that include the given version. -@end cartouche +that include the given version." +@end quotation + Followed, except in the case of tagged types. Tagged types involve implicit pointers to a local copy of a dispatch table, and these pointers have representations which thus depend on a particular elaboration of the package. It is not easy to see how it would be possible to follow this advice without severely impacting efficiency of execution. -@cindex Exception information -@unnumberedsec 11.4.1(19): Exception Information -@sp 1 -@cartouche -@code{Exception_Message} by default and @code{Exception_Information} +@geindex Exception information + +@node RM 11 4 1 19 Exception Information,RM 11 5 28 Suppression of Checks,RM 10 2 1 12 Consistent Representation,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-11-4-1-19-exception-information}@anchor{1c8} +@section RM 11.4.1(19): Exception Information + + +@quotation + +"@cite{Exception_Message} by default and @cite{Exception_Information} should produce information useful for -debugging. @code{Exception_Message} should be short, about one -line. @code{Exception_Information} can be long. @code{Exception_Message} +debugging. @cite{Exception_Message} should be short, about one +line. @cite{Exception_Information} can be long. @cite{Exception_Message} should not include the -@code{Exception_Name}. @code{Exception_Information} should include both -the @code{Exception_Name} and the @code{Exception_Message}. -@end cartouche +@cite{Exception_Name}. @cite{Exception_Information} should include both +the @cite{Exception_Name} and the @cite{Exception_Message}." +@end quotation + Followed. For each exception that doesn't have a specified -@code{Exception_Message}, the compiler generates one containing the location -of the raise statement. This location has the form ``file:line'', where -file is the short file name (without path information) and line is the line +@cite{Exception_Message}, the compiler generates one containing the location +of the raise statement. This location has the form 'file_name:line', where +file_name is the short file name (without path information) and line is the line number in the file. Note that in the case of the Zero Cost Exception mechanism, these messages become redundant with the Exception_Information that contains a full backtrace of the calling sequence, so they are disabled. To disable explicitly the generation of the source location message, use the -Pragma @code{Discard_Names}. - -@cindex Suppression of checks -@cindex Checks, suppression of -@unnumberedsec 11.5(28): Suppression of Checks -@sp 1 -@cartouche -The implementation should minimize the code executed for checks that -have been suppressed. -@end cartouche +Pragma @cite{Discard_Names}. + +@geindex Suppression of checks + +@geindex Checks +@geindex suppression of + +@node RM 11 5 28 Suppression of Checks,RM 13 1 21-24 Representation Clauses,RM 11 4 1 19 Exception Information,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-11-5-28-suppression-of-checks}@anchor{1c9} +@section RM 11.5(28): Suppression of Checks + + +@quotation + +"The implementation should minimize the code executed for checks that +have been suppressed." +@end quotation + Followed. -@cindex Representation clauses -@unnumberedsec 13.1 (21-24): Representation Clauses -@sp 1 -@cartouche -The recommended level of support for all representation items is +@geindex Representation clauses + +@node RM 13 1 21-24 Representation Clauses,RM 13 2 6-8 Packed Types,RM 11 5 28 Suppression of Checks,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-1-21-24-representation-clauses}@anchor{1ca} +@section RM 13.1 (21-24): Representation Clauses + + +@quotation + +"The recommended level of support for all representation items is qualified as follows: -@end cartouche -@sp 1 -@cartouche + An implementation need not support representation items containing non-static expressions, except that an implementation should support a representation item for a given entity if each non-static expression in the representation item is a name that statically denotes a constant -declared before the entity. -@end cartouche +declared before the entity." +@end quotation + Followed. In fact, GNAT goes beyond the recommended level of support by allowing nonstatic expressions in some representation clauses even without the need to declare constants initialized with the values of such expressions. For example: -@smallexample @c ada +@example X : Integer; Y : Float; for Y'Address use X'Address;>> -@end smallexample -@sp 1 -@cartouche -An implementation need not support a specification for the @code{Size} + +"An implementation need not support a specification for the `Size` for a given composite subtype, nor the size or storage place for an object (including a component) of a given composite subtype, unless the constraints on the subtype and its composite subcomponents (if any) are -all static constraints. -@end cartouche +all static constraints." +@end example + Followed. Size Clauses are not permitted on non-static components, as described above. -@sp 1 -@cartouche -An aliased component, or a component whose type is by-reference, should -always be allocated at an addressable location. -@end cartouche +@quotation + +"An aliased component, or a component whose type is by-reference, should +always be allocated at an addressable location." +@end quotation + Followed. -@cindex Packed types -@unnumberedsec 13.2(6-8): Packed Types -@sp 1 -@cartouche -If a type is packed, then the implementation should try to minimize +@geindex Packed types + +@node RM 13 2 6-8 Packed Types,RM 13 3 14-19 Address Clauses,RM 13 1 21-24 Representation Clauses,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-2-6-8-packed-types}@anchor{1cb} +@section RM 13.2(6-8): Packed Types + + +@quotation + +"If a type is packed, then the implementation should try to minimize storage allocated to objects of the type, possibly at the expense of speed of accessing components, subject to reasonable complexity in addressing calculations. -@end cartouche -@sp 1 -@cartouche -The recommended level of support pragma @code{Pack} is: + +The recommended level of support pragma @cite{Pack} is: For a packed record type, the components should be packed as tightly as possible subject to the Sizes of the component subtypes, and subject to -any @code{record_representation_clause} that applies to the type; the +any @cite{record_representation_clause} that applies to the type; the implementation may, but need not, reorder components or cross aligned -word boundaries to improve the packing. A component whose @code{Size} is -greater than the word size may be allocated an integral number of words. -@end cartouche +word boundaries to improve the packing. A component whose @cite{Size} is +greater than the word size may be allocated an integral number of words." +@end quotation + Followed. Tight packing of arrays is supported for all component sizes up to 64-bits. If the array component size is 1 (that is to say, if the component is a boolean type or an enumeration type with two values) @@ -11671,1005 +13148,1330 @@ then values of the type are implicitly initialized to zero. This happens both for objects of the packed type, and for objects that have a subcomponent of the packed type. -@sp 1 -@cartouche -An implementation should support Address clauses for imported -subprograms. -@end cartouche +@quotation + +"An implementation should support Address clauses for imported +subprograms." +@end quotation + Followed. -@cindex @code{Address} clauses -@unnumberedsec 13.3(14-19): Address Clauses - -@sp 1 -@cartouche -For an array @var{X}, @code{@var{X}'Address} should point at the first -component of the array, and not at the array bounds. -@end cartouche + +@geindex Address clauses + +@node RM 13 3 14-19 Address Clauses,RM 13 3 29-35 Alignment Clauses,RM 13 2 6-8 Packed Types,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-3-14-19-address-clauses}@anchor{1cc} +@section RM 13.3(14-19): Address Clauses + + +@quotation + +"For an array @cite{X}, @code{X'Address} should point at the first +component of the array, and not at the array bounds." +@end quotation + Followed. -@sp 1 -@cartouche -The recommended level of support for the @code{Address} attribute is: +@quotation + +"The recommended level of support for the @cite{Address} attribute is: -@code{@var{X}'Address} should produce a useful result if @var{X} is an +@code{X'Address} should produce a useful result if @cite{X} is an object that is aliased or of a by-reference type, or is an entity whose -@code{Address} has been specified. -@end cartouche +@cite{Address} has been specified." +@end quotation + Followed. A valid address will be produced even if none of those conditions have been met. If necessary, the object is forced into memory to ensure the address is valid. -@sp 1 -@cartouche -An implementation should support @code{Address} clauses for imported -subprograms. -@end cartouche +@quotation + +"An implementation should support @cite{Address} clauses for imported +subprograms." +@end quotation + Followed. -@sp 1 -@cartouche -Objects (including subcomponents) that are aliased or of a by-reference -type should be allocated on storage element boundaries. -@end cartouche +@quotation + +"Objects (including subcomponents) that are aliased or of a by-reference +type should be allocated on storage element boundaries." +@end quotation + Followed. -@sp 1 -@cartouche -If the @code{Address} of an object is specified, or it is imported or exported, +@quotation + +"If the @cite{Address} of an object is specified, or it is imported or exported, then the implementation should not perform optimizations based on -assumptions of no aliases. -@end cartouche +assumptions of no aliases." +@end quotation + Followed. -@cindex @code{Alignment} clauses -@unnumberedsec 13.3(29-35): Alignment Clauses -@sp 1 -@cartouche -The recommended level of support for the @code{Alignment} attribute for +@geindex Alignment clauses + +@node RM 13 3 29-35 Alignment Clauses,RM 13 3 42-43 Size Clauses,RM 13 3 14-19 Address Clauses,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-3-29-35-alignment-clauses}@anchor{1cd} +@section RM 13.3(29-35): Alignment Clauses + + +@quotation + +"The recommended level of support for the @cite{Alignment} attribute for subtypes is: An implementation should support specified Alignments that are factors and multiples of the number of storage elements per word, subject to the -following: -@end cartouche +following:" +@end quotation + Followed. -@sp 1 -@cartouche -An implementation need not support specified @code{Alignment}s for -combinations of @code{Size}s and @code{Alignment}s that cannot be easily -loaded and stored by available machine instructions. -@end cartouche +@quotation + +"An implementation need not support specified Alignments for +combinations of Sizes and Alignments that cannot be easily +loaded and stored by available machine instructions." +@end quotation + Followed. -@sp 1 -@cartouche -An implementation need not support specified @code{Alignment}s that are -greater than the maximum @code{Alignment} the implementation ever returns by -default. -@end cartouche +@quotation + +"An implementation need not support specified Alignments that are +greater than the maximum @cite{Alignment} the implementation ever returns by +default." +@end quotation + Followed. -@sp 1 -@cartouche -The recommended level of support for the @code{Alignment} attribute for +@quotation + +"The recommended level of support for the @cite{Alignment} attribute for objects is: -Same as above, for subtypes, but in addition: -@end cartouche +Same as above, for subtypes, but in addition:" +@end quotation + Followed. -@sp 1 -@cartouche -For stand-alone library-level objects of statically constrained -subtypes, the implementation should support all @code{Alignment}s +@quotation + +"For stand-alone library-level objects of statically constrained +subtypes, the implementation should support all alignments supported by the target linker. For example, page alignment is likely to -be supported for such objects, but not for subtypes. -@end cartouche +be supported for such objects, but not for subtypes." +@end quotation + Followed. -@cindex @code{Size} clauses -@unnumberedsec 13.3(42-43): Size Clauses -@sp 1 -@cartouche -The recommended level of support for the @code{Size} attribute of +@geindex Size clauses + +@node RM 13 3 42-43 Size Clauses,RM 13 3 50-56 Size Clauses,RM 13 3 29-35 Alignment Clauses,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-3-42-43-size-clauses}@anchor{1ce} +@section RM 13.3(42-43): Size Clauses + + +@quotation + +"The recommended level of support for the @cite{Size} attribute of objects is: -A @code{Size} clause should be supported for an object if the specified -@code{Size} is at least as large as its subtype's @code{Size}, and +A @cite{Size} clause should be supported for an object if the specified +@cite{Size} is at least as large as its subtype's @cite{Size}, and corresponds to a size in storage elements that is a multiple of the -object's @code{Alignment} (if the @code{Alignment} is nonzero). -@end cartouche +object's @cite{Alignment} (if the @cite{Alignment} is nonzero)." +@end quotation + Followed. -@unnumberedsec 13.3(50-56): Size Clauses -@sp 1 -@cartouche -If the @code{Size} of a subtype is specified, and allows for efficient +@node RM 13 3 50-56 Size Clauses,RM 13 3 71-73 Component Size Clauses,RM 13 3 42-43 Size Clauses,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-3-50-56-size-clauses}@anchor{1cf} +@section RM 13.3(50-56): Size Clauses + + +@quotation + +"If the @cite{Size} of a subtype is specified, and allows for efficient independent addressability (see 9.10) on the target architecture, then -the @code{Size} of the following objects of the subtype should equal the -@code{Size} of the subtype: +the @cite{Size} of the following objects of the subtype should equal the +@cite{Size} of the subtype: + +Aliased objects (including components)." +@end quotation -Aliased objects (including components). -@end cartouche Followed. -@sp 1 -@cartouche -@code{Size} clause on a composite subtype should not affect the -internal layout of components. -@end cartouche +@quotation + +"@cite{Size} clause on a composite subtype should not affect the +internal layout of components." +@end quotation + Followed. But note that this can be overridden by use of the implementation pragma Implicit_Packing in the case of packed arrays. -@sp 1 -@cartouche -The recommended level of support for the @code{Size} attribute of subtypes is: -@end cartouche -@sp 1 -@cartouche -The @code{Size} (if not specified) of a static discrete or fixed point +@quotation + +"The recommended level of support for the @cite{Size} attribute of subtypes is: + +The @cite{Size} (if not specified) of a static discrete or fixed point subtype should be the number of bits needed to represent each value belonging to the subtype using an unbiased representation, leaving space for a sign bit only if the subtype contains negative values. If such a subtype is a first subtype, then an implementation should support a -specified @code{Size} for it that reflects this representation. -@end cartouche +specified @cite{Size} for it that reflects this representation." +@end quotation + Followed. -@sp 1 -@cartouche -For a subtype implemented with levels of indirection, the @code{Size} +@quotation + +"For a subtype implemented with levels of indirection, the @cite{Size} should include the size of the pointers, but not the size of what they -point at. -@end cartouche +point at." +@end quotation + Followed. -@cindex @code{Component_Size} clauses -@unnumberedsec 13.3(71-73): Component Size Clauses -@sp 1 -@cartouche -The recommended level of support for the @code{Component_Size} +@geindex Component_Size clauses + +@node RM 13 3 71-73 Component Size Clauses,RM 13 4 9-10 Enumeration Representation Clauses,RM 13 3 50-56 Size Clauses,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-3-71-73-component-size-clauses}@anchor{1d0} +@section RM 13.3(71-73): Component Size Clauses + + +@quotation + +"The recommended level of support for the @cite{Component_Size} attribute is: -@end cartouche -@sp 1 -@cartouche -An implementation need not support specified @code{Component_Sizes} that are -less than the @code{Size} of the component subtype. -@end cartouche + +An implementation need not support specified @cite{Component_Sizes} that are +less than the @cite{Size} of the component subtype." +@end quotation + Followed. -@sp 1 -@cartouche -An implementation should support specified @code{Component_Size}s that +@quotation + +"An implementation should support specified Component_Sizes that are factors and multiples of the word size. For such -@code{Component_Size}s, the array should contain no gaps between -components. For other @code{Component_Size}s (if supported), the array +Component_Sizes, the array should contain no gaps between +components. For other Component_Sizes (if supported), the array should contain no gaps between components when packing is also specified; the implementation should forbid this combination in cases -where it cannot support a no-gaps representation. -@end cartouche +where it cannot support a no-gaps representation." +@end quotation + Followed. -@cindex Enumeration representation clauses -@cindex Representation clauses, enumeration -@unnumberedsec 13.4(9-10): Enumeration Representation Clauses -@sp 1 -@cartouche -The recommended level of support for enumeration representation clauses +@geindex Enumeration representation clauses + +@geindex Representation clauses +@geindex enumeration + +@node RM 13 4 9-10 Enumeration Representation Clauses,RM 13 5 1 17-22 Record Representation Clauses,RM 13 3 71-73 Component Size Clauses,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-4-9-10-enumeration-representation-clauses}@anchor{1d1} +@section RM 13.4(9-10): Enumeration Representation Clauses + + +@quotation + +"The recommended level of support for enumeration representation clauses is: An implementation need not support enumeration representation clauses for boolean types, but should at minimum support the internal codes in -the range @code{System.Min_Int.System.Max_Int}. -@end cartouche +the range @cite{System.Min_Int .. System.Max_Int}." +@end quotation + Followed. -@cindex Record representation clauses -@cindex Representation clauses, records -@unnumberedsec 13.5.1(17-22): Record Representation Clauses -@sp 1 -@cartouche -The recommended level of support for -@*@code{record_representation_clauses} is: +@geindex Record representation clauses + +@geindex Representation clauses +@geindex records + +@node RM 13 5 1 17-22 Record Representation Clauses,RM 13 5 2 5 Storage Place Attributes,RM 13 4 9-10 Enumeration Representation Clauses,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-5-1-17-22-record-representation-clauses}@anchor{1d2} +@section RM 13.5.1(17-22): Record Representation Clauses + + +@quotation + +"The recommended level of support for +@cite{record_representation_clauses} is: An implementation should support storage places that can be extracted with a load, mask, shift sequence of machine code, and set with a load, shift, mask, store sequence, given the available machine instructions -and run-time model. -@end cartouche +and run-time model." +@end quotation + Followed. -@sp 1 -@cartouche -A storage place should be supported if its size is equal to the -@code{Size} of the component subtype, and it starts and ends on a -boundary that obeys the @code{Alignment} of the component subtype. -@end cartouche +@quotation + +"A storage place should be supported if its size is equal to the +@cite{Size} of the component subtype, and it starts and ends on a +boundary that obeys the @cite{Alignment} of the component subtype." +@end quotation + Followed. -@sp 1 -@cartouche -If the default bit ordering applies to the declaration of a given type, -then for a component whose subtype's @code{Size} is less than the word +@quotation + +"If the default bit ordering applies to the declaration of a given type, +then for a component whose subtype's @cite{Size} is less than the word size, any storage place that does not cross an aligned word boundary -should be supported. -@end cartouche +should be supported." +@end quotation + Followed. -@sp 1 -@cartouche -An implementation may reserve a storage place for the tag field of a -tagged type, and disallow other components from overlapping that place. -@end cartouche +@quotation + +"An implementation may reserve a storage place for the tag field of a +tagged type, and disallow other components from overlapping that place." +@end quotation + Followed. The storage place for the tag field is the beginning of the tagged record, and its size is Address'Size. GNAT will reject an explicit component clause for the tag field. -@sp 1 -@cartouche -An implementation need not support a @code{component_clause} for a +@quotation + +"An implementation need not support a @cite{component_clause} for a component of an extension part if the storage place is not after the storage places of all components of the parent type, whether or not -those storage places had been specified. -@end cartouche +those storage places had been specified." +@end quotation + Followed. The above advice on record representation clauses is followed, and all mentioned features are implemented. -@cindex Storage place attributes -@unnumberedsec 13.5.2(5): Storage Place Attributes -@sp 1 -@cartouche -If a component is represented using some form of pointer (such as an +@geindex Storage place attributes + +@node RM 13 5 2 5 Storage Place Attributes,RM 13 5 3 7-8 Bit Ordering,RM 13 5 1 17-22 Record Representation Clauses,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-5-2-5-storage-place-attributes}@anchor{1d3} +@section RM 13.5.2(5): Storage Place Attributes + + +@quotation + +"If a component is represented using some form of pointer (such as an offset) to the actual data of the component, and this data is contiguous with the rest of the object, then the storage place attributes should reflect the place of the actual data, not the pointer. If a component is allocated discontinuously from the rest of the object, then a warning should be generated upon reference to one of its storage place -attributes. -@end cartouche -Followed. There are no such components in GNAT@. - -@cindex Bit ordering -@unnumberedsec 13.5.3(7-8): Bit Ordering -@sp 1 -@cartouche -The recommended level of support for the non-default bit ordering is: -@end cartouche -@sp 1 -@cartouche -If @code{Word_Size} = @code{Storage_Unit}, then the implementation +attributes." +@end quotation + +Followed. There are no such components in GNAT. + +@geindex Bit ordering + +@node RM 13 5 3 7-8 Bit Ordering,RM 13 7 37 Address as Private,RM 13 5 2 5 Storage Place Attributes,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-5-3-7-8-bit-ordering}@anchor{1d4} +@section RM 13.5.3(7-8): Bit Ordering + + +@quotation + +"The recommended level of support for the non-default bit ordering is: + +If @cite{Word_Size} = @cite{Storage_Unit}, then the implementation should support the non-default bit ordering in addition to the default -bit ordering. -@end cartouche +bit ordering." +@end quotation + Followed. Word size does not equal storage size in this implementation. Thus non-default bit ordering is not supported. -@cindex @code{Address}, as private type -@unnumberedsec 13.7(37): Address as Private -@sp 1 -@cartouche -@code{Address} should be of a private type. -@end cartouche +@geindex Address +@geindex as private type + +@node RM 13 7 37 Address as Private,RM 13 7 1 16 Address Operations,RM 13 5 3 7-8 Bit Ordering,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-7-37-address-as-private}@anchor{1d5} +@section RM 13.7(37): Address as Private + + +@quotation + +"@cite{Address} should be of a private type." +@end quotation + Followed. -@cindex Operations, on @code{Address} -@cindex @code{Address}, operations of -@unnumberedsec 13.7.1(16): Address Operations -@sp 1 -@cartouche -Operations in @code{System} and its children should reflect the target +@geindex Operations +@geindex on `Address` + +@geindex Address +@geindex operations of + +@node RM 13 7 1 16 Address Operations,RM 13 9 14-17 Unchecked Conversion,RM 13 7 37 Address as Private,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-7-1-16-address-operations}@anchor{1d6} +@section RM 13.7.1(16): Address Operations + + +@quotation + +"Operations in @cite{System} and its children should reflect the target environment semantics as closely as is reasonable. For example, on most -machines, it makes sense for address arithmetic to ``wrap around''. -Operations that do not make sense should raise @code{Program_Error}. -@end cartouche +machines, it makes sense for address arithmetic to 'wrap around'. +Operations that do not make sense should raise @cite{Program_Error}." +@end quotation + Followed. Address arithmetic is modular arithmetic that wraps around. No -operation raises @code{Program_Error}, since all operations make sense. - -@cindex Unchecked conversion -@unnumberedsec 13.9(14-17): Unchecked Conversion -@sp 1 -@cartouche -The @code{Size} of an array object should not include its bounds; hence, -the bounds should not be part of the converted data. -@end cartouche +operation raises @cite{Program_Error}, since all operations make sense. + +@geindex Unchecked conversion + +@node RM 13 9 14-17 Unchecked Conversion,RM 13 11 23-25 Implicit Heap Usage,RM 13 7 1 16 Address Operations,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-9-14-17-unchecked-conversion}@anchor{1d7} +@section RM 13.9(14-17): Unchecked Conversion + + +@quotation + +"The @cite{Size} of an array object should not include its bounds; hence, +the bounds should not be part of the converted data." +@end quotation + Followed. -@sp 1 -@cartouche -The implementation should not generate unnecessary run-time checks to -ensure that the representation of @var{S} is a representation of the +@quotation + +"The implementation should not generate unnecessary run-time checks to +ensure that the representation of @cite{S} is a representation of the target type. It should take advantage of the permission to return by reference when possible. Restrictions on unchecked conversions should be -avoided unless required by the target environment. -@end cartouche +avoided unless required by the target environment." +@end quotation + Followed. There are no restrictions on unchecked conversion. A warning is generated if the source and target types do not have the same size since the semantics in this case may be target dependent. -@sp 1 -@cartouche -The recommended level of support for unchecked conversions is: -@end cartouche -@sp 1 -@cartouche +@quotation + +"The recommended level of support for unchecked conversions is: + Unchecked conversions should be supported and should be reversible in the cases where this clause defines the result. To enable meaningful use of unchecked conversion, a contiguous representation should be used for elementary subtypes, for statically constrained array subtypes whose component subtype is one of the subtypes described in this paragraph, and for record subtypes without discriminants whose component subtypes -are described in this paragraph. -@end cartouche +are described in this paragraph." +@end quotation + Followed. -@cindex Heap usage, implicit -@unnumberedsec 13.11(23-25): Implicit Heap Usage -@sp 1 -@cartouche -An implementation should document any cases in which it dynamically +@geindex Heap usage +@geindex implicit + +@node RM 13 11 23-25 Implicit Heap Usage,RM 13 11 2 17 Unchecked Deallocation,RM 13 9 14-17 Unchecked Conversion,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-11-23-25-implicit-heap-usage}@anchor{1d8} +@section RM 13.11(23-25): Implicit Heap Usage + + +@quotation + +"An implementation should document any cases in which it dynamically allocates heap storage for a purpose other than the evaluation of an -allocator. -@end cartouche +allocator." +@end quotation + Followed, the only other points at which heap storage is dynamically allocated are as follows: -@itemize @bullet -@item + +@itemize * + +@item At initial elaboration time, to allocate dynamically sized global objects. -@item +@item To allocate space for a task when a task is created. -@item +@item To extend the secondary stack dynamically when needed. The secondary stack is used for returning variable length results. @end itemize -@sp 1 -@cartouche -A default (implementation-provided) storage pool for an + +@quotation + +"A default (implementation-provided) storage pool for an access-to-constant type should not have overhead to support deallocation of -individual objects. -@end cartouche +individual objects." +@end quotation + Followed. -@sp 1 -@cartouche -A storage pool for an anonymous access type should be created at the +@quotation + +"A storage pool for an anonymous access type should be created at the point of an allocator for the type, and be reclaimed when the designated -object becomes inaccessible. -@end cartouche +object becomes inaccessible." +@end quotation + Followed. -@cindex Unchecked deallocation -@unnumberedsec 13.11.2(17): Unchecked De-allocation -@sp 1 -@cartouche -For a standard storage pool, @code{Free} should actually reclaim the -storage. -@end cartouche +@geindex Unchecked deallocation + +@node RM 13 11 2 17 Unchecked Deallocation,RM 13 13 2 17 Stream Oriented Attributes,RM 13 11 23-25 Implicit Heap Usage,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-11-2-17-unchecked-deallocation}@anchor{1d9} +@section RM 13.11.2(17): Unchecked Deallocation + + +@quotation + +"For a standard storage pool, @cite{Free} should actually reclaim the +storage." +@end quotation + Followed. -@cindex Stream oriented attributes -@unnumberedsec 13.13.2(17): Stream Oriented Attributes -@sp 1 -@cartouche -If a stream element is the same size as a storage element, then the -normal in-memory representation should be used by @code{Read} and -@code{Write} for scalar objects. Otherwise, @code{Read} and @code{Write} +@geindex Stream oriented attributes + +@node RM 13 13 2 17 Stream Oriented Attributes,RM A 1 52 Names of Predefined Numeric Types,RM 13 11 2 17 Unchecked Deallocation,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-13-13-2-17-stream-oriented-attributes}@anchor{1da} +@section RM 13.13.2(17): Stream Oriented Attributes + + +@quotation + +"If a stream element is the same size as a storage element, then the +normal in-memory representation should be used by @cite{Read} and +@cite{Write} for scalar objects. Otherwise, @cite{Read} and @cite{Write} should use the smallest number of stream elements needed to represent -all values in the base range of the scalar type. -@end cartouche +all values in the base range of the scalar type." +@end quotation Followed. By default, GNAT uses the interpretation suggested by AI-195, which specifies using the size of the first subtype. However, such an implementation is based on direct binary representations and is therefore target- and endianness-dependent. To address this issue, GNAT also supplies an alternate implementation -of the stream attributes @code{Read} and @code{Write}, +of the stream attributes @cite{Read} and @cite{Write}, which uses the target-independent XDR standard representation for scalar types. -@cindex XDR representation -@cindex @code{Read} attribute -@cindex @code{Write} attribute -@cindex Stream oriented attributes + +@geindex XDR representation + +@geindex Read attribute + +@geindex Write attribute + +@geindex Stream oriented attributes + The XDR implementation is provided as an alternative body of the -@code{System.Stream_Attributes} package, in the file -@file{s-stratt-xdr.adb} in the GNAT library. -There is no @file{s-stratt-xdr.ads} file. +@cite{System.Stream_Attributes} package, in the file +@code{s-stratt-xdr.adb} in the GNAT library. +There is no @code{s-stratt-xdr.ads} file. In order to install the XDR implementation, do the following: -@enumerate -@item Replace the default implementation of the -@code{System.Stream_Attributes} package with the XDR implementation. + + +@itemize * + +@item +Replace the default implementation of the +@cite{System.Stream_Attributes} package with the XDR implementation. For example on a Unix platform issue the commands: -@smallexample + +@example $ mv s-stratt.adb s-stratt-default.adb $ mv s-stratt-xdr.adb s-stratt.adb -@end smallexample +@end example -@item +@item Rebuild the GNAT run-time library as documented in -@ref{GNAT and Libraries,,, gnat_ugn, @value{EDITION} User's Guide}. -@end enumerate +the @cite{GNAT and Libraries} section of the @cite{GNAT User's Guide}. +@end itemize -@unnumberedsec A.1(52): Names of Predefined Numeric Types -@sp 1 -@cartouche -If an implementation provides additional named predefined integer types, -then the names should end with @samp{Integer} as in -@samp{Long_Integer}. If an implementation provides additional named +@node RM A 1 52 Names of Predefined Numeric Types,RM A 3 2 49 Ada Characters Handling,RM 13 13 2 17 Stream Oriented Attributes,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-a-1-52-names-of-predefined-numeric-types}@anchor{1db} +@section RM A.1(52): Names of Predefined Numeric Types + + +@quotation + +"If an implementation provides additional named predefined integer types, +then the names should end with @code{Integer} as in +@code{Long_Integer}. If an implementation provides additional named predefined floating point types, then the names should end with -@samp{Float} as in @samp{Long_Float}. -@end cartouche +@code{Float} as in @code{Long_Float}." +@end quotation + Followed. -@findex Ada.Characters.Handling -@unnumberedsec A.3.2(49): @code{Ada.Characters.Handling} -@sp 1 -@cartouche -If an implementation provides a localized definition of @code{Character} -or @code{Wide_Character}, then the effects of the subprograms in -@code{Characters.Handling} should reflect the localizations. See also -3.5.2. -@end cartouche +@geindex Ada.Characters.Handling + +@node RM A 3 2 49 Ada Characters Handling,RM A 4 4 106 Bounded-Length String Handling,RM A 1 52 Names of Predefined Numeric Types,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-a-3-2-49-ada-characters-handling}@anchor{1dc} +@section RM A.3.2(49): @cite{Ada.Characters.Handling} + + +@quotation + +"If an implementation provides a localized definition of @cite{Character} +or @cite{Wide_Character}, then the effects of the subprograms in +@cite{Characters.Handling} should reflect the localizations. +See also 3.5.2." +@end quotation + Followed. GNAT provides no such localized definitions. -@cindex Bounded-length strings -@unnumberedsec A.4.4(106): Bounded-Length String Handling -@sp 1 -@cartouche -Bounded string objects should not be implemented by implicit pointers -and dynamic allocation. -@end cartouche +@geindex Bounded-length strings + +@node RM A 4 4 106 Bounded-Length String Handling,RM A 5 2 46-47 Random Number Generation,RM A 3 2 49 Ada Characters Handling,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-a-4-4-106-bounded-length-string-handling}@anchor{1dd} +@section RM A.4.4(106): Bounded-Length String Handling + + +@quotation + +"Bounded string objects should not be implemented by implicit pointers +and dynamic allocation." +@end quotation + Followed. No implicit pointers or dynamic allocation are used. -@cindex Random number generation -@unnumberedsec A.5.2(46-47): Random Number Generation -@sp 1 -@cartouche -Any storage associated with an object of type @code{Generator} should be -reclaimed on exit from the scope of the object. -@end cartouche +@geindex Random number generation + +@node RM A 5 2 46-47 Random Number Generation,RM A 10 7 23 Get_Immediate,RM A 4 4 106 Bounded-Length String Handling,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-a-5-2-46-47-random-number-generation}@anchor{1de} +@section RM A.5.2(46-47): Random Number Generation + + +@quotation + +"Any storage associated with an object of type @cite{Generator} should be +reclaimed on exit from the scope of the object." +@end quotation + Followed. -@sp 1 -@cartouche -If the generator period is sufficiently long in relation to the number +@quotation + +"If the generator period is sufficiently long in relation to the number of distinct initiator values, then each possible value of -@code{Initiator} passed to @code{Reset} should initiate a sequence of +@cite{Initiator} passed to @cite{Reset} should initiate a sequence of random numbers that does not, in a practical sense, overlap the sequence initiated by any other value. If this is not possible, then the mapping between initiator values and generator states should be a rapidly -varying function of the initiator value. -@end cartouche +varying function of the initiator value." +@end quotation + Followed. The generator period is sufficiently long for the first condition here to hold true. -@findex Get_Immediate -@unnumberedsec A.10.7(23): @code{Get_Immediate} -@sp 1 -@cartouche -The @code{Get_Immediate} procedures should be implemented with +@geindex Get_Immediate + +@node RM A 10 7 23 Get_Immediate,RM B 1 39-41 Pragma Export,RM A 5 2 46-47 Random Number Generation,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-a-10-7-23-get-immediate}@anchor{1df} +@section RM A.10.7(23): @cite{Get_Immediate} + + +@quotation + +"The @cite{Get_Immediate} procedures should be implemented with unbuffered input. For a device such as a keyboard, input should be -@dfn{available} if a key has already been typed, whereas for a disk +available if a key has already been typed, whereas for a disk file, input should always be available except at end of file. For a file associated with a keyboard-like device, any line-editing features of the underlying operating system should be disabled during the execution of -@code{Get_Immediate}. -@end cartouche +@cite{Get_Immediate}." +@end quotation + Followed on all targets except VxWorks. For VxWorks, there is no way to provide this functionality that does not result in the input buffer being -flushed before the @code{Get_Immediate} call. A special unit -@code{Interfaces.Vxworks.IO} is provided that contains routines to enable +flushed before the @cite{Get_Immediate} call. A special unit +@cite{Interfaces.Vxworks.IO} is provided that contains routines to enable this functionality. -@findex Export -@unnumberedsec B.1(39-41): Pragma @code{Export} -@sp 1 -@cartouche -If an implementation supports pragma @code{Export} to a given language, +@geindex Export + +@node RM B 1 39-41 Pragma Export,RM B 2 12-13 Package Interfaces,RM A 10 7 23 Get_Immediate,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-b-1-39-41-pragma-export}@anchor{1e0} +@section RM B.1(39-41): Pragma @cite{Export} + + +@quotation + +"If an implementation supports pragma @cite{Export} to a given language, then it should also allow the main subprogram to be written in that language. It should support some mechanism for invoking the elaboration of the Ada library units included in the system, and for invoking the finalization of the environment task. On typical systems, the recommended mechanism is to provide two subprograms whose link names are -@code{adainit} and @code{adafinal}. @code{adainit} should contain the -elaboration code for library units. @code{adafinal} should contain the +@cite{adainit} and @cite{adafinal}. @cite{adainit} should contain the +elaboration code for library units. @cite{adafinal} should contain the finalization code. These subprograms should have no effect the second -and subsequent time they are called. -@end cartouche +and subsequent time they are called." +@end quotation + Followed. -@sp 1 -@cartouche -Automatic elaboration of pre-elaborated packages should be -provided when pragma @code{Export} is supported. -@end cartouche +@quotation + +"Automatic elaboration of pre-elaborated packages should be +provided when pragma @cite{Export} is supported." +@end quotation + Followed when the main program is in Ada. If the main program is in a foreign language, then -@code{adainit} must be called to elaborate pre-elaborated +@cite{adainit} must be called to elaborate pre-elaborated packages. -@sp 1 -@cartouche -For each supported convention @var{L} other than @code{Intrinsic}, an -implementation should support @code{Import} and @code{Export} pragmas -for objects of @var{L}-compatible types and for subprograms, and pragma -@code{Convention} for @var{L}-eligible types and for subprograms, +@quotation + +"For each supported convention @cite{L} other than @cite{Intrinsic}, an +implementation should support @cite{Import} and @cite{Export} pragmas +for objects of @cite{L}-compatible types and for subprograms, and pragma +@cite{Convention} for @cite{L}-eligible types and for subprograms, presuming the other language has corresponding features. Pragma -@code{Convention} need not be supported for scalar types. -@end cartouche +@cite{Convention} need not be supported for scalar types." +@end quotation + Followed. -@cindex Package @code{Interfaces} -@findex Interfaces -@unnumberedsec B.2(12-13): Package @code{Interfaces} -@sp 1 -@cartouche -For each implementation-defined convention identifier, there should be a +@geindex Package Interfaces + +@geindex Interfaces + +@node RM B 2 12-13 Package Interfaces,RM B 3 63-71 Interfacing with C,RM B 1 39-41 Pragma Export,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-b-2-12-13-package-interfaces}@anchor{1e1} +@section RM B.2(12-13): Package @cite{Interfaces} + + +@quotation + +"For each implementation-defined convention identifier, there should be a child package of package Interfaces with the corresponding name. This package should contain any declarations that would be useful for interfacing to the language (implementation) represented by the convention. Any declarations useful for interfacing to any language on the given hardware architecture should be provided directly in -@code{Interfaces}. -@end cartouche +@cite{Interfaces}." +@end quotation + Followed. -@sp 1 -@cartouche -An implementation supporting an interface to C, COBOL, or Fortran should +@quotation + +"An implementation supporting an interface to C, COBOL, or Fortran should provide the corresponding package or packages described in the following -clauses. -@end cartouche +clauses." +@end quotation + Followed. GNAT provides all the packages described in this section. -@cindex C, interfacing with -@unnumberedsec B.3(63-71): Interfacing with C -@sp 1 -@cartouche -An implementation should support the following interface correspondences -between Ada and C@. -@end cartouche +@geindex C +@geindex interfacing with + +@node RM B 3 63-71 Interfacing with C,RM B 4 95-98 Interfacing with COBOL,RM B 2 12-13 Package Interfaces,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-b-3-63-71-interfacing-with-c}@anchor{1e2} +@section RM B.3(63-71): Interfacing with C + + +@quotation + +"An implementation should support the following interface correspondences +between Ada and C." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada procedure corresponds to a void-returning C function. -@end cartouche +@quotation + +"An Ada procedure corresponds to a void-returning C function." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada function corresponds to a non-void C function. -@end cartouche +@quotation + +"An Ada function corresponds to a non-void C function." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada @code{in} scalar parameter is passed as a scalar argument to a C -function. -@end cartouche +@quotation + +"An Ada @cite{in} scalar parameter is passed as a scalar argument to a C +function." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada @code{in} parameter of an access-to-object type with designated -type @var{T} is passed as a @code{@var{t}*} argument to a C function, -where @var{t} is the C type corresponding to the Ada type @var{T}. -@end cartouche +@quotation + +"An Ada @cite{in} parameter of an access-to-object type with designated +type @cite{T} is passed as a @code{t*} argument to a C function, +where @code{t} is the C type corresponding to the Ada type @cite{T}." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada access @var{T} parameter, or an Ada @code{out} or @code{in out} -parameter of an elementary type @var{T}, is passed as a @code{@var{t}*} -argument to a C function, where @var{t} is the C type corresponding to -the Ada type @var{T}. In the case of an elementary @code{out} or -@code{in out} parameter, a pointer to a temporary copy is used to -preserve by-copy semantics. -@end cartouche +@quotation + +"An Ada access @cite{T} parameter, or an Ada @cite{out} or @cite{in out} +parameter of an elementary type @cite{T}, is passed as a @code{t*} +argument to a C function, where @code{t} is the C type corresponding to +the Ada type @cite{T}. In the case of an elementary @cite{out} or +@cite{in out} parameter, a pointer to a temporary copy is used to +preserve by-copy semantics." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada parameter of a record type @var{T}, of any mode, is passed as a -@code{@var{t}*} argument to a C function, where @var{t} is the C -structure corresponding to the Ada type @var{T}. -@end cartouche +@quotation + +"An Ada parameter of a record type @cite{T}, of any mode, is passed as a +@code{t*} argument to a C function, where @code{t} is the C +structure corresponding to the Ada type @cite{T}." +@end quotation + Followed. This convention may be overridden by the use of the C_Pass_By_Copy pragma, or Convention, or by explicitly specifying the mechanism for a given call using an extended import or export pragma. -@sp 1 -@cartouche -An Ada parameter of an array type with component type @var{T}, of any -mode, is passed as a @code{@var{t}*} argument to a C function, where -@var{t} is the C type corresponding to the Ada type @var{T}. -@end cartouche +@quotation + +"An Ada parameter of an array type with component type @cite{T}, of any +mode, is passed as a @code{t*} argument to a C function, where +@code{t} is the C type corresponding to the Ada type @cite{T}." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada parameter of an access-to-subprogram type is passed as a pointer +@quotation + +"An Ada parameter of an access-to-subprogram type is passed as a pointer to a C function whose prototype corresponds to the designated -subprogram's specification. -@end cartouche +subprogram's specification." +@end quotation + Followed. -@cindex COBOL, interfacing with -@unnumberedsec B.4(95-98): Interfacing with COBOL -@sp 1 -@cartouche -An Ada implementation should support the following interface -correspondences between Ada and COBOL@. -@end cartouche +@geindex COBOL +@geindex interfacing with + +@node RM B 4 95-98 Interfacing with COBOL,RM B 5 22-26 Interfacing with Fortran,RM B 3 63-71 Interfacing with C,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-b-4-95-98-interfacing-with-cobol}@anchor{1e3} +@section RM B.4(95-98): Interfacing with COBOL + + +@quotation + +"An Ada implementation should support the following interface +correspondences between Ada and COBOL." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada access @var{T} parameter is passed as a @samp{BY REFERENCE} data item of -the COBOL type corresponding to @var{T}. -@end cartouche +@quotation + +"An Ada access @cite{T} parameter is passed as a @code{BY REFERENCE} data item of +the COBOL type corresponding to @cite{T}." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada in scalar parameter is passed as a @samp{BY CONTENT} data item of -the corresponding COBOL type. -@end cartouche +@quotation + +"An Ada in scalar parameter is passed as a @code{BY CONTENT} data item of +the corresponding COBOL type." +@end quotation + Followed. -@sp 1 -@cartouche -Any other Ada parameter is passed as a @samp{BY REFERENCE} data item of the +@quotation + +"Any other Ada parameter is passed as a @code{BY REFERENCE} data item of the COBOL type corresponding to the Ada parameter type; for scalars, a local -copy is used if necessary to ensure by-copy semantics. -@end cartouche +copy is used if necessary to ensure by-copy semantics." +@end quotation + Followed. -@cindex Fortran, interfacing with -@unnumberedsec B.5(22-26): Interfacing with Fortran -@sp 1 -@cartouche -An Ada implementation should support the following interface -correspondences between Ada and Fortran: -@end cartouche +@geindex Fortran +@geindex interfacing with + +@node RM B 5 22-26 Interfacing with Fortran,RM C 1 3-5 Access to Machine Operations,RM B 4 95-98 Interfacing with COBOL,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-b-5-22-26-interfacing-with-fortran}@anchor{1e4} +@section RM B.5(22-26): Interfacing with Fortran + + +@quotation + +"An Ada implementation should support the following interface +correspondences between Ada and Fortran:" +@end quotation + Followed. -@sp 1 -@cartouche -An Ada procedure corresponds to a Fortran subroutine. -@end cartouche +@quotation + +"An Ada procedure corresponds to a Fortran subroutine." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada function corresponds to a Fortran function. -@end cartouche +@quotation + +"An Ada function corresponds to a Fortran function." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada parameter of an elementary, array, or record type @var{T} is -passed as a @var{T} argument to a Fortran procedure, where @var{T} is -the Fortran type corresponding to the Ada type @var{T}, and where the +@quotation + +"An Ada parameter of an elementary, array, or record type @cite{T} is +passed as a @cite{T} argument to a Fortran procedure, where @cite{T} is +the Fortran type corresponding to the Ada type @cite{T}, and where the INTENT attribute of the corresponding dummy argument matches the Ada formal parameter mode; the Fortran implementation's parameter passing conventions are used. For elementary types, a local copy is used if -necessary to ensure by-copy semantics. -@end cartouche +necessary to ensure by-copy semantics." +@end quotation + Followed. -@sp 1 -@cartouche -An Ada parameter of an access-to-subprogram type is passed as a +@quotation + +"An Ada parameter of an access-to-subprogram type is passed as a reference to a Fortran procedure whose interface corresponds to the -designated subprogram's specification. -@end cartouche +designated subprogram's specification." +@end quotation + Followed. -@cindex Machine operations -@unnumberedsec C.1(3-5): Access to Machine Operations -@sp 1 -@cartouche -The machine code or intrinsic support should allow access to all +@geindex Machine operations + +@node RM C 1 3-5 Access to Machine Operations,RM C 1 10-16 Access to Machine Operations,RM B 5 22-26 Interfacing with Fortran,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-c-1-3-5-access-to-machine-operations}@anchor{1e5} +@section RM C.1(3-5): Access to Machine Operations + + +@quotation + +"The machine code or intrinsic support should allow access to all operations normally available to assembly language programmers for the -target environment, including privileged instructions, if any. -@end cartouche +target environment, including privileged instructions, if any." +@end quotation + Followed. -@sp 1 -@cartouche -The interfacing pragmas (see Annex B) should support interface to +@quotation + +"The interfacing pragmas (see Annex B) should support interface to assembler; the default assembler should be associated with the -convention identifier @code{Assembler}. -@end cartouche +convention identifier @cite{Assembler}." +@end quotation + Followed. -@sp 1 -@cartouche -If an entity is exported to assembly language, then the implementation +@quotation + +"If an entity is exported to assembly language, then the implementation should allocate it at an addressable location, and should ensure that it is retained by the linking process, even if not otherwise referenced from the Ada code. The implementation should assume that any call to a machine code or assembler subprogram is allowed to read or update every -object that is specified as exported. -@end cartouche +object that is specified as exported." +@end quotation + Followed. -@unnumberedsec C.1(10-16): Access to Machine Operations -@sp 1 -@cartouche -The implementation should ensure that little or no overhead is -associated with calling intrinsic and machine-code subprograms. -@end cartouche +@node RM C 1 10-16 Access to Machine Operations,RM C 3 28 Interrupt Support,RM C 1 3-5 Access to Machine Operations,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-c-1-10-16-access-to-machine-operations}@anchor{1e6} +@section RM C.1(10-16): Access to Machine Operations + + +@quotation + +"The implementation should ensure that little or no overhead is +associated with calling intrinsic and machine-code subprograms." +@end quotation + Followed for both intrinsics and machine-code subprograms. -@sp 1 -@cartouche -It is recommended that intrinsic subprograms be provided for convenient +@quotation + +"It is recommended that intrinsic subprograms be provided for convenient access to any machine operations that provide special capabilities or efficiency and that are not otherwise available through the language -constructs. -@end cartouche +constructs." +@end quotation + Followed. A full set of machine operation intrinsic subprograms is provided. -@sp 1 -@cartouche -Atomic read-modify-write operations---e.g.@:, test and set, compare and -swap, decrement and test, enqueue/dequeue. -@end cartouche +@quotation + +"Atomic read-modify-write operations---e.g., test and set, compare and +swap, decrement and test, enqueue/dequeue." +@end quotation + Followed on any target supporting such operations. -@sp 1 -@cartouche -Standard numeric functions---e.g.@:, sin, log. -@end cartouche +@quotation + +"Standard numeric functions---e.g.:, sin, log." +@end quotation + Followed on any target supporting such operations. -@sp 1 -@cartouche -String manipulation operations---e.g.@:, translate and test. -@end cartouche +@quotation + +"String manipulation operations---e.g.:, translate and test." +@end quotation + Followed on any target supporting such operations. -@sp 1 -@cartouche -Vector operations---e.g.@:, compare vector against thresholds. -@end cartouche +@quotation + +"Vector operations---e.g.:, compare vector against thresholds." +@end quotation + Followed on any target supporting such operations. -@sp 1 -@cartouche -Direct operations on I/O ports. -@end cartouche +@quotation + +"Direct operations on I/O ports." +@end quotation + Followed on any target supporting such operations. -@cindex Interrupt support -@unnumberedsec C.3(28): Interrupt Support -@sp 1 -@cartouche -If the @code{Ceiling_Locking} policy is not in effect, the +@geindex Interrupt support + +@node RM C 3 28 Interrupt Support,RM C 3 1 20-21 Protected Procedure Handlers,RM C 1 10-16 Access to Machine Operations,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-c-3-28-interrupt-support}@anchor{1e7} +@section RM C.3(28): Interrupt Support + + +@quotation + +"If the @cite{Ceiling_Locking} policy is not in effect, the implementation should provide means for the application to specify which interrupts are to be blocked during protected actions, if the underlying -system allows for a finer-grain control of interrupt blocking. -@end cartouche +system allows for a finer-grain control of interrupt blocking." +@end quotation + Followed. The underlying system does not allow for finer-grain control of interrupt blocking. -@cindex Protected procedure handlers -@unnumberedsec C.3.1(20-21): Protected Procedure Handlers -@sp 1 -@cartouche -Whenever possible, the implementation should allow interrupt handlers to -be called directly by the hardware. -@end cartouche +@geindex Protected procedure handlers + +@node RM C 3 1 20-21 Protected Procedure Handlers,RM C 3 2 25 Package Interrupts,RM C 3 28 Interrupt Support,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-c-3-1-20-21-protected-procedure-handlers}@anchor{1e8} +@section RM C.3.1(20-21): Protected Procedure Handlers + + +@quotation + +"Whenever possible, the implementation should allow interrupt handlers to +be called directly by the hardware." +@end quotation + Followed on any target where the underlying operating system permits such direct calls. -@sp 1 -@cartouche -Whenever practical, violations of any -implementation-defined restrictions should be detected before run time. -@end cartouche +@quotation + +"Whenever practical, violations of any +implementation-defined restrictions should be detected before run time." +@end quotation + Followed. Compile time warnings are given when possible. -@cindex Package @code{Interrupts} -@findex Interrupts -@unnumberedsec C.3.2(25): Package @code{Interrupts} +@geindex Package `Interrupts` + +@geindex Interrupts + +@node RM C 3 2 25 Package Interrupts,RM C 4 14 Pre-elaboration Requirements,RM C 3 1 20-21 Protected Procedure Handlers,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-c-3-2-25-package-interrupts}@anchor{1e9} +@section RM C.3.2(25): Package @cite{Interrupts} + -@sp 1 -@cartouche -If implementation-defined forms of interrupt handler procedures are +@quotation + +"If implementation-defined forms of interrupt handler procedures are supported, such as protected procedures with parameters, then for each -such form of a handler, a type analogous to @code{Parameterless_Handler} -should be specified in a child package of @code{Interrupts}, with the -same operations as in the predefined package Interrupts. -@end cartouche +such form of a handler, a type analogous to @cite{Parameterless_Handler} +should be specified in a child package of @cite{Interrupts}, with the +same operations as in the predefined package Interrupts." +@end quotation + Followed. -@cindex Pre-elaboration requirements -@unnumberedsec C.4(14): Pre-elaboration Requirements -@sp 1 -@cartouche -It is recommended that pre-elaborated packages be implemented in such a +@geindex Pre-elaboration requirements + +@node RM C 4 14 Pre-elaboration Requirements,RM C 5 8 Pragma Discard_Names,RM C 3 2 25 Package Interrupts,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-c-4-14-pre-elaboration-requirements}@anchor{1ea} +@section RM C.4(14): Pre-elaboration Requirements + + +@quotation + +"It is recommended that pre-elaborated packages be implemented in such a way that there should be little or no code executed at run time for the elaboration of entities not already covered by the Implementation -Requirements. -@end cartouche -Followed. Executable code is generated in some cases, e.g.@: loops +Requirements." +@end quotation + +Followed. Executable code is generated in some cases, e.g., loops to initialize large arrays. -@unnumberedsec C.5(8): Pragma @code{Discard_Names} -@sp 1 -@cartouche -If the pragma applies to an entity, then the implementation should +@node RM C 5 8 Pragma Discard_Names,RM C 7 2 30 The Package Task_Attributes,RM C 4 14 Pre-elaboration Requirements,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-c-5-8-pragma-discard-names}@anchor{1eb} +@section RM C.5(8): Pragma @cite{Discard_Names} + + +@quotation + +"If the pragma applies to an entity, then the implementation should reduce the amount of storage used for storing names associated with that -entity. -@end cartouche +entity." +@end quotation + Followed. -@cindex Package @code{Task_Attributes} -@findex Task_Attributes -@unnumberedsec C.7.2(30): The Package Task_Attributes -@sp 1 -@cartouche -Some implementations are targeted to domains in which memory use at run +@geindex Package Task_Attributes + +@geindex Task_Attributes + +@node RM C 7 2 30 The Package Task_Attributes,RM D 3 17 Locking Policies,RM C 5 8 Pragma Discard_Names,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-c-7-2-30-the-package-task-attributes}@anchor{1ec} +@section RM C.7.2(30): The Package Task_Attributes + + +@quotation + +"Some implementations are targeted to domains in which memory use at run time must be completely deterministic. For such implementations, it is recommended that the storage for task attributes will be pre-allocated statically and not from the heap. This can be accomplished by either placing restrictions on the number and the size of the task's -attributes, or by using the pre-allocated storage for the first @var{N} +attributes, or by using the pre-allocated storage for the first @cite{N} attribute objects, and the heap for the others. In the latter case, -@var{N} should be documented. -@end cartouche +@cite{N} should be documented." +@end quotation + Not followed. This implementation is not targeted to such a domain. -@cindex Locking Policies -@unnumberedsec D.3(17): Locking Policies +@geindex Locking Policies + +@node RM D 3 17 Locking Policies,RM D 4 16 Entry Queuing Policies,RM C 7 2 30 The Package Task_Attributes,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-d-3-17-locking-policies}@anchor{1ed} +@section RM D.3(17): Locking Policies + + +@quotation + +"The implementation should use names that end with @code{_Locking} for +locking policies defined by the implementation." +@end quotation -@sp 1 -@cartouche -The implementation should use names that end with @samp{_Locking} for -locking policies defined by the implementation. -@end cartouche Followed. Two implementation-defined locking policies are defined, -whose names (@code{Inheritance_Locking} and -@code{Concurrent_Readers_Locking}) follow this suggestion. - -@cindex Entry queuing policies -@unnumberedsec D.4(16): Entry Queuing Policies -@sp 1 -@cartouche -Names that end with @samp{_Queuing} should be used -for all implementation-defined queuing policies. -@end cartouche +whose names (@cite{Inheritance_Locking} and +@cite{Concurrent_Readers_Locking}) follow this suggestion. + +@geindex Entry queuing policies + +@node RM D 4 16 Entry Queuing Policies,RM D 6 9-10 Preemptive Abort,RM D 3 17 Locking Policies,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-d-4-16-entry-queuing-policies}@anchor{1ee} +@section RM D.4(16): Entry Queuing Policies + + +@quotation + +"Names that end with @code{_Queuing} should be used +for all implementation-defined queuing policies." +@end quotation + Followed. No such implementation-defined queuing policies exist. -@cindex Preemptive abort -@unnumberedsec D.6(9-10): Preemptive Abort -@sp 1 -@cartouche -Even though the @code{abort_statement} is included in the list of +@geindex Preemptive abort + +@node RM D 6 9-10 Preemptive Abort,RM D 7 21 Tasking Restrictions,RM D 4 16 Entry Queuing Policies,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-d-6-9-10-preemptive-abort}@anchor{1ef} +@section RM D.6(9-10): Preemptive Abort + + +@quotation + +"Even though the @cite{abort_statement} is included in the list of potentially blocking operations (see 9.5.1), it is recommended that this statement be implemented in a way that never requires the task executing -the @code{abort_statement} to block. -@end cartouche +the @cite{abort_statement} to block." +@end quotation + Followed. -@sp 1 -@cartouche -On a multi-processor, the delay associated with aborting a task on +@quotation + +"On a multi-processor, the delay associated with aborting a task on another processor should be bounded; the implementation should use -periodic polling, if necessary, to achieve this. -@end cartouche +periodic polling, if necessary, to achieve this." +@end quotation + Followed. -@cindex Tasking restrictions -@unnumberedsec D.7(21): Tasking Restrictions -@sp 1 -@cartouche -When feasible, the implementation should take advantage of the specified -restrictions to produce a more efficient implementation. -@end cartouche +@geindex Tasking restrictions + +@node RM D 7 21 Tasking Restrictions,RM D 8 47-49 Monotonic Time,RM D 6 9-10 Preemptive Abort,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-d-7-21-tasking-restrictions}@anchor{1f0} +@section RM D.7(21): Tasking Restrictions + + +@quotation + +"When feasible, the implementation should take advantage of the specified +restrictions to produce a more efficient implementation." +@end quotation + GNAT currently takes advantage of these restrictions by providing an optimized run time when the Ravenscar profile and the GNAT restricted run time set -of restrictions are specified. See pragma @code{Profile (Ravenscar)} and -pragma @code{Profile (Restricted)} for more details. - -@cindex Time, monotonic -@unnumberedsec D.8(47-49): Monotonic Time -@sp 1 -@cartouche -When appropriate, implementations should provide configuration -mechanisms to change the value of @code{Tick}. -@end cartouche +of restrictions are specified. See pragma @cite{Profile (Ravenscar)} and +pragma @cite{Profile (Restricted)} for more details. + +@geindex Time +@geindex monotonic + +@node RM D 8 47-49 Monotonic Time,RM E 5 28-29 Partition Communication Subsystem,RM D 7 21 Tasking Restrictions,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-d-8-47-49-monotonic-time}@anchor{1f1} +@section RM D.8(47-49): Monotonic Time + + +@quotation + +"When appropriate, implementations should provide configuration +mechanisms to change the value of @cite{Tick}." +@end quotation + Such configuration mechanisms are not appropriate to this implementation and are thus not supported. -@sp 1 -@cartouche -It is recommended that @code{Calendar.Clock} and @code{Real_Time.Clock} -be implemented as transformations of the same time base. -@end cartouche +@quotation + +"It is recommended that @cite{Calendar.Clock} and @cite{Real_Time.Clock} +be implemented as transformations of the same time base." +@end quotation + Followed. -@sp 1 -@cartouche -It is recommended that the @dfn{best} time base which exists in +@quotation + +"It is recommended that the best time base which exists in the underlying system be available to the application through -@code{Clock}. @dfn{Best} may mean highest accuracy or largest range. -@end cartouche +@cite{Clock}. @cite{Best} may mean highest accuracy or largest range." +@end quotation + Followed. -@cindex Partition communication subsystem -@cindex PCS -@unnumberedsec E.5(28-29): Partition Communication Subsystem -@sp 1 -@cartouche -Whenever possible, the PCS on the called partition should allow for +@geindex Partition communication subsystem + +@geindex PCS + +@node RM E 5 28-29 Partition Communication Subsystem,RM F 7 COBOL Support,RM D 8 47-49 Monotonic Time,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-e-5-28-29-partition-communication-subsystem}@anchor{1f2} +@section RM E.5(28-29): Partition Communication Subsystem + + +@quotation + +"Whenever possible, the PCS on the called partition should allow for multiple tasks to call the RPC-receiver with different messages and should allow them to block until the corresponding subprogram body -returns. -@end cartouche +returns." +@end quotation + Followed by GLADE, a separately supplied PCS that can be used with GNAT. -@sp 1 -@cartouche -The @code{Write} operation on a stream of type @code{Params_Stream_Type} -should raise @code{Storage_Error} if it runs out of space trying to -write the @code{Item} into the stream. -@end cartouche +@quotation + +"The @cite{Write} operation on a stream of type @cite{Params_Stream_Type} +should raise @cite{Storage_Error} if it runs out of space trying to +write the @cite{Item} into the stream." +@end quotation + Followed by GLADE, a separately supplied PCS that can be used with -GNAT@. +GNAT. + +@geindex COBOL support -@cindex COBOL support -@unnumberedsec F(7): COBOL Support -@sp 1 -@cartouche -If COBOL (respectively, C) is widely supported in the target +@node RM F 7 COBOL Support,RM F 1 2 Decimal Radix Support,RM E 5 28-29 Partition Communication Subsystem,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-f-7-cobol-support}@anchor{1f3} +@section RM F(7): COBOL Support + + +@quotation + +"If COBOL (respectively, C) is widely supported in the target environment, implementations supporting the Information Systems Annex -should provide the child package @code{Interfaces.COBOL} (respectively, -@code{Interfaces.C}) specified in Annex B and should support a -@code{convention_identifier} of COBOL (respectively, C) in the interfacing +should provide the child package @cite{Interfaces.COBOL} (respectively, +@cite{Interfaces.C}) specified in Annex B and should support a +@cite{convention_identifier} of COBOL (respectively, C) in the interfacing pragmas (see Annex B), thus allowing Ada programs to interface with -programs written in that language. -@end cartouche +programs written in that language." +@end quotation + Followed. -@cindex Decimal radix support -@unnumberedsec F.1(2): Decimal Radix Support -@sp 1 -@cartouche -Packed decimal should be used as the internal representation for objects -of subtype @var{S} when @var{S}'Machine_Radix = 10. -@end cartouche -Not followed. GNAT ignores @var{S}'Machine_Radix and always uses binary +@geindex Decimal radix support + +@node RM F 1 2 Decimal Radix Support,RM G Numerics,RM F 7 COBOL Support,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-f-1-2-decimal-radix-support}@anchor{1f4} +@section RM F.1(2): Decimal Radix Support + + +@quotation + +"Packed decimal should be used as the internal representation for objects +of subtype @cite{S} when @cite{S}'Machine_Radix = 10." +@end quotation + +Not followed. GNAT ignores @cite{S}'Machine_Radix and always uses binary representations. -@cindex Numerics -@unnumberedsec G: Numerics -@sp 2 -@cartouche -If Fortran (respectively, C) is widely supported in the target +@geindex Numerics + +@node RM G Numerics,RM G 1 1 56-58 Complex Types,RM F 1 2 Decimal Radix Support,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-g-numerics}@anchor{1f5} +@section RM G: Numerics + + +@quotation + +"If Fortran (respectively, C) is widely supported in the target environment, implementations supporting the Numerics Annex -should provide the child package @code{Interfaces.Fortran} (respectively, -@code{Interfaces.C}) specified in Annex B and should support a -@code{convention_identifier} of Fortran (respectively, C) in the interfacing +should provide the child package @cite{Interfaces.Fortran} (respectively, +@cite{Interfaces.C}) specified in Annex B and should support a +@cite{convention_identifier} of Fortran (respectively, C) in the interfacing pragmas (see Annex B), thus allowing Ada programs to interface with -programs written in that language. -@end cartouche +programs written in that language." +@end quotation + Followed. -@cindex Complex types -@unnumberedsec G.1.1(56-58): Complex Types -@sp 2 -@cartouche -Because the usual mathematical meaning of multiplication of a complex +@geindex Complex types + +@node RM G 1 1 56-58 Complex Types,RM G 1 2 49 Complex Elementary Functions,RM G Numerics,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-g-1-1-56-58-complex-types}@anchor{1f6} +@section RM G.1.1(56-58): Complex Types + + +@quotation + +"Because the usual mathematical meaning of multiplication of a complex operand and a real operand is that of the scaling of both components of the former by the latter, an implementation should not perform this operation by first promoting the real operand to complex type and then @@ -12681,18 +14483,19 @@ component by the zero component obtained during promotion yields a NaN that propagates into the final result.) Analogous advice applies in the case of multiplication of a complex operand and a pure-imaginary operand, and in the case of division of a complex operand by a real or -pure-imaginary operand. -@end cartouche +pure-imaginary operand." +@end quotation + Not followed. -@sp 1 -@cartouche -Similarly, because the usual mathematical meaning of addition of a +@quotation + +"Similarly, because the usual mathematical meaning of addition of a complex operand and a real operand is that the imaginary operand remains unchanged, an implementation should not perform this operation by first promoting the real operand to complex type and then performing a full -complex addition. In implementations in which the @code{Signed_Zeros} -attribute of the component type is @code{True} (and which therefore +complex addition. In implementations in which the @cite{Signed_Zeros} +attribute of the component type is @cite{True} (and which therefore conform to IEC 559:1989 in regard to the handling of the sign of zero in predefined arithmetic operations), the latter technique will not generate the required result when the imaginary component of the complex @@ -12700,92 +14503,118 @@ operand is a negatively signed zero. (Explicit addition of the negative zero to the zero obtained during promotion yields a positive zero.) Analogous advice applies in the case of addition of a complex operand and a pure-imaginary operand, and in the case of subtraction of a -complex operand and a real or pure-imaginary operand. -@end cartouche +complex operand and a real or pure-imaginary operand." +@end quotation + Not followed. -@sp 1 -@cartouche -Implementations in which @code{Real'Signed_Zeros} is @code{True} should +@quotation + +"Implementations in which @cite{Real'Signed_Zeros} is @cite{True} should attempt to provide a rational treatment of the signs of zero results and -result components. As one example, the result of the @code{Argument} +result components. As one example, the result of the @cite{Argument} function should have the sign of the imaginary component of the -parameter @code{X} when the point represented by that parameter lies on +parameter @cite{X} when the point represented by that parameter lies on the positive real axis; as another, the sign of the imaginary component -of the @code{Compose_From_Polar} function should be the same as -(respectively, the opposite of) that of the @code{Argument} parameter when that -parameter has a value of zero and the @code{Modulus} parameter has a -nonnegative (respectively, negative) value. -@end cartouche +of the @cite{Compose_From_Polar} function should be the same as +(respectively, the opposite of) that of the @cite{Argument} parameter when that +parameter has a value of zero and the @cite{Modulus} parameter has a +nonnegative (respectively, negative) value." +@end quotation + Followed. -@cindex Complex elementary functions -@unnumberedsec G.1.2(49): Complex Elementary Functions -@sp 1 -@cartouche -Implementations in which @code{Complex_Types.Real'Signed_Zeros} is -@code{True} should attempt to provide a rational treatment of the signs +@geindex Complex elementary functions + +@node RM G 1 2 49 Complex Elementary Functions,RM G 2 4 19 Accuracy Requirements,RM G 1 1 56-58 Complex Types,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-g-1-2-49-complex-elementary-functions}@anchor{1f7} +@section RM G.1.2(49): Complex Elementary Functions + + +@quotation + +"Implementations in which @cite{Complex_Types.Real'Signed_Zeros} is +@cite{True} should attempt to provide a rational treatment of the signs of zero results and result components. For example, many of the complex elementary functions have components that are odd functions of one of the parameter components; in these cases, the result component should have the sign of the parameter component at the origin. Other complex elementary functions have zero components whose sign is opposite that of a parameter component at the origin, or is always positive or always -negative. -@end cartouche +negative." +@end quotation + Followed. -@cindex Accuracy requirements -@unnumberedsec G.2.4(19): Accuracy Requirements -@sp 1 -@cartouche -The versions of the forward trigonometric functions without a -@code{Cycle} parameter should not be implemented by calling the -corresponding version with a @code{Cycle} parameter of -@code{2.0*Numerics.Pi}, since this will not provide the required +@geindex Accuracy requirements + +@node RM G 2 4 19 Accuracy Requirements,RM G 2 6 15 Complex Arithmetic Accuracy,RM G 1 2 49 Complex Elementary Functions,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-g-2-4-19-accuracy-requirements}@anchor{1f8} +@section RM G.2.4(19): Accuracy Requirements + + +@quotation + +"The versions of the forward trigonometric functions without a +@cite{Cycle} parameter should not be implemented by calling the +corresponding version with a @cite{Cycle} parameter of +@cite{2.0*Numerics.Pi}, since this will not provide the required accuracy in some portions of the domain. For the same reason, the -version of @code{Log} without a @code{Base} parameter should not be -implemented by calling the corresponding version with a @code{Base} -parameter of @code{Numerics.e}. -@end cartouche +version of @cite{Log} without a @cite{Base} parameter should not be +implemented by calling the corresponding version with a @cite{Base} +parameter of @cite{Numerics.e}." +@end quotation + Followed. -@cindex Complex arithmetic accuracy -@cindex Accuracy, complex arithmetic -@unnumberedsec G.2.6(15): Complex Arithmetic Accuracy - -@sp 1 -@cartouche -The version of the @code{Compose_From_Polar} function without a -@code{Cycle} parameter should not be implemented by calling the -corresponding version with a @code{Cycle} parameter of -@code{2.0*Numerics.Pi}, since this will not provide the required -accuracy in some portions of the domain. -@end cartouche +@geindex Complex arithmetic accuracy + +@geindex Accuracy +@geindex complex arithmetic + +@node RM G 2 6 15 Complex Arithmetic Accuracy,RM H 6 15/2 Pragma Partition_Elaboration_Policy,RM G 2 4 19 Accuracy Requirements,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-g-2-6-15-complex-arithmetic-accuracy}@anchor{1f9} +@section RM G.2.6(15): Complex Arithmetic Accuracy + + +@quotation + +"The version of the @cite{Compose_From_Polar} function without a +@cite{Cycle} parameter should not be implemented by calling the +corresponding version with a @cite{Cycle} parameter of +@cite{2.0*Numerics.Pi}, since this will not provide the required +accuracy in some portions of the domain." +@end quotation + Followed. -@cindex Sequential elaboration policy -@unnumberedsec H.6(15/2): Pragma Partition_Elaboration_Policy +@geindex Sequential elaboration policy + +@node RM H 6 15/2 Pragma Partition_Elaboration_Policy,,RM G 2 6 15 Complex Arithmetic Accuracy,Implementation Advice +@anchor{gnat_rm/implementation_advice rm-h-6-15-2-pragma-partition-elaboration-policy}@anchor{1fa} +@section RM H.6(15/2): Pragma Partition_Elaboration_Policy + + +@quotation -@sp 1 -@cartouche -If the partition elaboration policy is @code{Sequential} and the +"If the partition elaboration policy is @cite{Sequential} and the Environment task becomes permanently blocked during elaboration then the partition is deadlocked and it is recommended that the partition be -immediately terminated. -@end cartouche +immediately terminated." +@end quotation + Not followed. -@c ----------------------------------------- -@node Implementation Defined Characteristics +@node Implementation Defined Characteristics,Intrinsic Subprograms,Implementation Advice,Top +@anchor{gnat_rm/implementation_defined_characteristics implementation-defined-characteristics}@anchor{b}@anchor{gnat_rm/implementation_defined_characteristics doc}@anchor{1fb}@anchor{gnat_rm/implementation_defined_characteristics id1}@anchor{1fc} @chapter Implementation Defined Characteristics -@noindent + In addition to the implementation dependent pragmas and attributes, and the implementation advice, there are a number of other Ada features that are potentially implementation dependent and are designated as implementation-defined. These are mentioned throughout the Ada Reference -Manual, and are summarized in Annex M@. +Manual, and are summarized in Annex M. A requirement for conforming Ada compilers is that they provide documentation describing how the implementation deals with each of these @@ -12800,350 +14629,418 @@ in each entry below correspond to the paragraph numbers in the Ada Reference Manual. -@itemize @bullet -@sp 1 -@item -@cartouche -@noindent -Whether or not each recommendation given in Implementation -Advice is followed. See 1.1.2(37). -@end cartouche -@noindent -@xref{Implementation Advice}. +@itemize * + +@item +"Whether or not each recommendation given in Implementation +Advice is followed. See 1.1.2(37)." +@end itemize +See @ref{a,,Implementation Advice}. + + +@itemize * + +@item +"Capacity limitations of the implementation. See 1.1.3(3)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -Capacity limitations of the implementation. See 1.1.3(3). -@end cartouche -@noindent The complexity of programs that can be processed is limited only by the total amount of available virtual memory, and disk space for the generated object files. -@sp 1 -@item -@cartouche -@noindent -Variations from the standard that are impractical to avoid -given the implementation's execution environment. See 1.1.3(6). -@end cartouche -@noindent +@itemize * + +@item +"Variations from the standard that are impractical to avoid +given the implementation's execution environment. See 1.1.3(6)." +@end itemize + There are no variations from the standard. -@sp 1 -@item -@cartouche -@noindent -Which @code{code_statement}s cause external -interactions. See 1.1.3(10). -@end cartouche -@noindent -Any @code{code_statement} can potentially cause external interactions. - -@sp 1 -@item -@cartouche -@noindent -The coded representation for the text of an Ada -program. See 2.1(4). -@end cartouche -@noindent +@itemize * + +@item +"Which code_statements cause external +interactions. See 1.1.3(10)." +@end itemize + +Any @cite{code_statement} can potentially cause external interactions. + + +@itemize * + +@item +"The coded representation for the text of an Ada +program. See 2.1(4)." +@end itemize + See separate section on source representation. -@sp 1 -@item -@cartouche -@noindent -The control functions allowed in comments. See 2.1(14). -@end cartouche -@noindent +@itemize * + +@item +"The control functions allowed in comments. See 2.1(14)." +@end itemize + See separate section on source representation. -@sp 1 -@item -@cartouche -@noindent -The representation for an end of line. See 2.2(2). -@end cartouche -@noindent + +@itemize * + +@item +"The representation for an end of line. See 2.2(2)." +@end itemize + See separate section on source representation. -@sp 1 -@item -@cartouche -@noindent -Maximum supported line length and lexical element -length. See 2.2(15). -@end cartouche -@noindent + +@itemize * + +@item +"Maximum supported line length and lexical element +length. See 2.2(15)." +@end itemize + The maximum line length is 255 characters and the maximum length of a lexical element is also 255 characters. This is the default setting -if not overridden by the use of compiler switch @option{-gnaty} (which -sets the maximum to 79) or @option{-gnatyMnn} which allows the maximum +if not overridden by the use of compiler switch @emph{-gnaty} (which +sets the maximum to 79) or @emph{-gnatyMnn} which allows the maximum line length to be specified to be any value up to 32767. The maximum length of a lexical element is the same as the maximum line length. -@sp 1 -@item -@cartouche -@noindent -Implementation defined pragmas. See 2.8(14). -@end cartouche -@noindent -@xref{Implementation Defined Pragmas}. +@itemize * -@sp 1 -@item -@cartouche -@noindent -Effect of pragma @code{Optimize}. See 2.8(27). -@end cartouche -@noindent -Pragma @code{Optimize}, if given with a @code{Time} or @code{Space} +@item +"Implementation defined pragmas. See 2.8(14)." +@end itemize + +See @ref{7,,Implementation Defined Pragmas}. + + +@itemize * + +@item +"Effect of pragma @cite{Optimize}. See 2.8(27)." +@end itemize + +Pragma @cite{Optimize}, if given with a @cite{Time} or @cite{Space} parameter, checks that the optimization flag is set, and aborts if it is not. -@sp 1 -@item -@cartouche -@noindent -The sequence of characters of the value returned by -@code{@var{S}'Image} when some of the graphic characters of -@code{@var{S}'Wide_Image} are not defined in @code{Character}. See -3.5(37). -@end cartouche -@noindent + +@itemize * + +@item +"The sequence of characters of the value returned by +@code{S'Image} when some of the graphic characters of +@code{S'Wide_Image} are not defined in @cite{Character}. See +3.5(37)." +@end itemize + The sequence of characters is as defined by the wide character encoding method used for the source. See section on source representation for further details. -@sp 1 + +@itemize * + +@item +"The predefined integer types declared in +@cite{Standard}. See 3.5.4(25)." +@end itemize + + +@multitable {xxxxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} +@headitem + +Type + +@tab + +Representation + @item -@cartouche -@noindent -The predefined integer types declared in -@code{Standard}. See 3.5.4(25). -@end cartouche -@noindent -@table @code -@item Short_Short_Integer + +@emph{Short_Short_Integer} + +@tab + 8 bit signed -@item Short_Integer + +@item + +@emph{Short_Integer} + +@tab + (Short) 16 bit signed -@item Integer + +@item + +@emph{Integer} + +@tab + 32 bit signed -@item Long_Integer -64 bit signed (on most 64 bit targets, depending on the C definition of long). + +@item + +@emph{Long_Integer} + +@tab + +64 bit signed (on most 64 bit targets, +depending on the C definition of long). 32 bit signed (all other targets) -@item Long_Long_Integer -64 bit signed -@end table -@sp 1 @item -@cartouche -@noindent -Any nonstandard integer types and the operators defined -for them. See 3.5.4(26). -@end cartouche -@noindent + +@emph{Long_Long_Integer} + +@tab + +64 bit signed + +@end multitable + + + +@itemize * + +@item +"Any nonstandard integer types and the operators defined +for them. See 3.5.4(26)." +@end itemize + There are no nonstandard integer types. -@sp 1 -@item -@cartouche -@noindent -Any nonstandard real types and the operators defined for -them. See 3.5.6(8). -@end cartouche -@noindent + +@itemize * + +@item +"Any nonstandard real types and the operators defined for +them. See 3.5.6(8)." +@end itemize + There are no nonstandard real types. -@sp 1 -@item -@cartouche -@noindent -What combinations of requested decimal precision and range -are supported for floating point types. See 3.5.7(7). -@end cartouche -@noindent + +@itemize * + +@item +"What combinations of requested decimal precision and range +are supported for floating point types. See 3.5.7(7)." +@end itemize + The precision and range is as defined by the IEEE standard. -@sp 1 + +@itemize * + +@item +"The predefined floating point types declared in +@cite{Standard}. See 3.5.7(16)." +@end itemize + + +@multitable {xxxxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} +@headitem + +Type + +@tab + +Representation + @item -@cartouche -@noindent -The predefined floating point types declared in -@code{Standard}. See 3.5.7(16). -@end cartouche -@noindent -@table @code -@item Short_Float + +@emph{Short_Float} + +@tab + 32 bit IEEE short -@item Float + +@item + +@emph{Float} + +@tab + (Short) 32 bit IEEE short -@item Long_Float -64 bit IEEE long -@item Long_Long_Float -64 bit IEEE long (80 bit IEEE long on x86 processors) -@end table -@sp 1 @item -@cartouche -@noindent -The small of an ordinary fixed point type. See 3.5.9(8). -@end cartouche -@noindent -@code{Fine_Delta} is 2**(@minus{}63) - -@sp 1 + +@emph{Long_Float} + +@tab + +64 bit IEEE long + @item -@cartouche -@noindent -What combinations of small, range, and digits are -supported for fixed point types. See 3.5.9(10). -@end cartouche -@noindent + +@emph{Long_Long_Float} + +@tab + +64 bit IEEE long (80 bit IEEE long on x86 processors) + +@end multitable + + + +@itemize * + +@item +"The small of an ordinary fixed point type. See 3.5.9(8)." +@end itemize + +@cite{Fine_Delta} is 2**(-63) + + +@itemize * + +@item +"What combinations of small, range, and digits are +supported for fixed point types. See 3.5.9(10)." +@end itemize + Any combinations are permitted that do not result in a small less than -@code{Fine_Delta} and do not result in a mantissa larger than 63 bits. +@cite{Fine_Delta} and do not result in a mantissa larger than 63 bits. If the mantissa is larger than 53 bits on machines where Long_Long_Float is 64 bits (true of all architectures except ia32), then the output from Text_IO is accurate to only 53 bits, rather than the full mantissa. This is because floating-point conversions are used to convert fixed point. -@sp 1 -@item -@cartouche -@noindent -The result of @code{Tags.Expanded_Name} for types declared -within an unnamed @code{block_statement}. See 3.9(10). -@end cartouche -@noindent -Block numbers of the form @code{B@var{nnn}}, where @var{nnn} is a + +@itemize * + +@item +"The result of @cite{Tags.Expanded_Name} for types declared +within an unnamed @cite{block_statement}. See 3.9(10)." +@end itemize + +Block numbers of the form @cite{B`nnn`}, where @cite{nnn} is a decimal integer are allocated. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined attributes. See 4.1.4(12). -@end cartouche -@noindent -@xref{Implementation Defined Attributes}. - -@sp 1 -@item -@cartouche -@noindent -Any implementation-defined time types. See 9.6(6). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined attributes. See 4.1.4(12)." +@end itemize + +See @ref{8,,Implementation Defined Attributes}. + + +@itemize * + +@item +"Any implementation-defined time types. See 9.6(6)." +@end itemize + There are no implementation-defined time types. -@sp 1 -@item -@cartouche -@noindent -The time base associated with relative delays. -@end cartouche -@noindent + +@itemize * + +@item +"The time base associated with relative delays." +@end itemize + See 9.6(20). The time base used is that provided by the C library -function @code{gettimeofday}. +function @cite{gettimeofday}. + + +@itemize * + +@item +"The time base of the type @cite{Calendar.Time}. See +9.6(23)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -The time base of the type @code{Calendar.Time}. See -9.6(23). -@end cartouche -@noindent The time base used is that provided by the C library function -@code{gettimeofday}. +@cite{gettimeofday}. -@sp 1 -@item -@cartouche -@noindent -The time zone used for package @code{Calendar} -operations. See 9.6(24). -@end cartouche -@noindent -The time zone used by package @code{Calendar} is the current system time zone + +@itemize * + +@item +"The time zone used for package @cite{Calendar} +operations. See 9.6(24)." +@end itemize + +The time zone used by package @cite{Calendar} is the current system time zone setting for local time, as accessed by the C library function -@code{localtime}. +@cite{localtime}. + + +@itemize * + +@item +"Any limit on @cite{delay_until_statements} of +@cite{select_statements}. See 9.6(29)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -Any limit on @code{delay_until_statements} of -@code{select_statements}. See 9.6(29). -@end cartouche -@noindent There are no such limits. -@sp 1 -@item -@cartouche -@noindent -Whether or not two non-overlapping parts of a composite + +@itemize * + +@item +"Whether or not two non-overlapping parts of a composite object are independently addressable, in the case where packing, record -layout, or @code{Component_Size} is specified for the object. See -9.10(1). -@end cartouche -@noindent +layout, or @cite{Component_Size} is specified for the object. See +9.10(1)." +@end itemize + Separate components are independently addressable if they do not share overlapping storage units. -@sp 1 -@item -@cartouche -@noindent -The representation for a compilation. See 10.1(2). -@end cartouche -@noindent + +@itemize * + +@item +"The representation for a compilation. See 10.1(2)." +@end itemize + A compilation is represented by a sequence of files presented to the -compiler in a single invocation of the @command{gcc} command. +compiler in a single invocation of the @emph{gcc} command. + + +@itemize * + +@item +"Any restrictions on compilations that contain multiple +compilation_units. See 10.1(4)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -Any restrictions on compilations that contain multiple -compilation_units. See 10.1(4). -@end cartouche -@noindent No single file can contain more than one compilation unit, but any sequence of files can be presented to the compiler as a single compilation. -@sp 1 -@item -@cartouche -@noindent -The mechanisms for creating an environment and for adding -and replacing compilation units. See 10.1.4(3). -@end cartouche -@noindent + +@itemize * + +@item +"The mechanisms for creating an environment and for adding +and replacing compilation units. See 10.1.4(3)." +@end itemize + See separate section on compilation model. -@sp 1 -@item -@cartouche -@noindent -The manner of explicitly assigning library units to a -partition. See 10.2(2). -@end cartouche -@noindent + +@itemize * + +@item +"The manner of explicitly assigning library units to a +partition. See 10.2(2)." +@end itemize + If a unit contains an Ada main program, then the Ada units for the partition are determined by recursive application of the rules in the Ada Reference Manual section 10.2(2-6). In other words, the Ada units will be those that @@ -13151,51 +15048,51 @@ are needed by the main program, and then this definition of need is applied recursively to those units, and the partition contains the transitive closure determined by this relationship. In short, all the necessary units are included, with no need to explicitly specify the list. If additional -units are required, e.g.@: by foreign language units, then all units must be +units are required, e.g., by foreign language units, then all units must be mentioned in the context clause of one of the needed Ada units. If the partition contains no main program, or if the main program is in a language other than Ada, then GNAT -provides the binder options @option{-z} and @option{-n} respectively, and in +provides the binder options @emph{-z} and @emph{-n} respectively, and in this case a list of units can be explicitly supplied to the binder for inclusion in the partition (all units needed by these units will also be included automatically). For full details on the use of these -options, refer to @ref{The GNAT Make Program gnatmake,,, gnat_ugn, -@value{EDITION} User's Guide}. +options, refer to the @cite{GNAT Make Program gnatmake} in the +@cite{GNAT User's Guide}. -@sp 1 -@item -@cartouche -@noindent -The implementation-defined means, if any, of specifying + +@itemize * + +@item +"The implementation-defined means, if any, of specifying which compilation units are needed by a given compilation unit. See -10.2(2). -@end cartouche -@noindent +10.2(2)." +@end itemize + The units needed by a given compilation unit are as defined in the Ada Reference Manual section 10.2(2-6). There are no implementation-defined pragmas or other implementation-defined means for specifying needed units. -@sp 1 -@item -@cartouche -@noindent -The manner of designating the main subprogram of a -partition. See 10.2(7). -@end cartouche -@noindent + +@itemize * + +@item +"The manner of designating the main subprogram of a +partition. See 10.2(7)." +@end itemize + The main program is designated by providing the name of the -corresponding @file{ALI} file as the input parameter to the binder. +corresponding @code{ALI} file as the input parameter to the binder. + + +@itemize * + +@item +"The order of elaboration of @cite{library_items}. See +10.2(18)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -The order of elaboration of @code{library_items}. See -10.2(18). -@end cartouche -@noindent The first constraint on ordering is that it meets the requirements of Chapter 10 of the Ada Reference Manual. This still leaves some implementation dependent choices, which are resolved by first @@ -13205,132 +15102,134 @@ clauses of a unit to determine the probably best choice, and third by elaborating in alphabetical order of unit names where a choice still remains. -@sp 1 -@item -@cartouche -@noindent -Parameter passing and function return for the main -subprogram. See 10.2(21). -@end cartouche -@noindent + +@itemize * + +@item +"Parameter passing and function return for the main +subprogram. See 10.2(21)." +@end itemize + The main program has no parameters. It may be a procedure, or a function returning an integer type. In the latter case, the returned integer value is the return code of the program (overriding any value that -may have been set by a call to @code{Ada.Command_Line.Set_Exit_Status}). +may have been set by a call to @cite{Ada.Command_Line.Set_Exit_Status}). + + +@itemize * + +@item +"The mechanisms for building and running partitions. See +10.2(24)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -The mechanisms for building and running partitions. See -10.2(24). -@end cartouche -@noindent GNAT itself supports programs with only a single partition. The GNATDIST tool provided with the GLADE package (which also includes an implementation of the PCS) provides a completely flexible method for building and running programs consisting of multiple partitions. See the separate GLADE manual for details. -@sp 1 -@item -@cartouche -@noindent -The details of program execution, including program -termination. See 10.2(25). -@end cartouche -@noindent + +@itemize * + +@item +"The details of program execution, including program +termination. See 10.2(25)." +@end itemize + See separate section on compilation model. -@sp 1 -@item -@cartouche -@noindent -The semantics of any non-active partitions supported by the -implementation. See 10.2(28). -@end cartouche -@noindent + +@itemize * + +@item +"The semantics of any non-active partitions supported by the +implementation. See 10.2(28)." +@end itemize + Passive partitions are supported on targets where shared memory is provided by the operating system. See the GLADE reference manual for further details. -@sp 1 -@item -@cartouche -@noindent -The information returned by @code{Exception_Message}. See -11.4.1(10). -@end cartouche -@noindent + +@itemize * + +@item +"The information returned by @cite{Exception_Message}. See +11.4.1(10)." +@end itemize + Exception message returns the null string unless a specific message has been passed by the program. -@sp 1 -@item -@cartouche -@noindent -The result of @code{Exceptions.Exception_Name} for types -declared within an unnamed @code{block_statement}. See 11.4.1(12). -@end cartouche -@noindent -Blocks have implementation defined names of the form @code{B@var{nnn}} -where @var{nnn} is an integer. - -@sp 1 -@item -@cartouche -@noindent -The information returned by -@code{Exception_Information}. See 11.4.1(13). -@end cartouche -@noindent -@code{Exception_Information} returns a string in the following format: - -@smallexample -@emph{Exception_Name:} nnnnn -@emph{Message:} mmmmm -@emph{PID:} ppp -@emph{Load address:} 0xhhhh -@emph{Call stack traceback locations:} + +@itemize * + +@item +"The result of @cite{Exceptions.Exception_Name} for types +declared within an unnamed @cite{block_statement}. See 11.4.1(12)." +@end itemize + +Blocks have implementation defined names of the form @cite{B`nnn`} +where @cite{nnn} is an integer. + + +@itemize * + +@item +"The information returned by +@cite{Exception_Information}. See 11.4.1(13)." +@end itemize + +@cite{Exception_Information} returns a string in the following format: + +@example +*Exception_Name:* nnnnn +*Message:* mmmmm +*PID:* ppp +*Load address:* 0xhhhh +*Call stack traceback locations:* 0xhhhh 0xhhhh 0xhhhh ... 0xhhh -@end smallexample +@end example -@noindent where -@itemize @bullet -@item -@code{nnnn} is the fully qualified name of the exception in all upper +@quotation + + +@itemize * + +@item +@cite{nnnn} is the fully qualified name of the exception in all upper case letters. This line is always present. -@item -@code{mmmm} is the message (this line present only if message is non-null) +@item +@cite{mmmm} is the message (this line present only if message is non-null) -@item -@code{ppp} is the Process Id value as a decimal integer (this line is +@item +@cite{ppp} is the Process Id value as a decimal integer (this line is present only if the Process Id is nonzero). Currently we are not making use of this field. -@item +@item The Load address line, the Call stack traceback locations line and the following values are present only if at least one traceback location was recorded. The Load address indicates the address at which the main executable was loaded; this line may not be present if operating system hasn't relocated the main executable. The values are given in C style format, with lower case letters for a-f, and only as many digits present as are necessary. +The line terminator sequence at the end of each line, including +the last line is a single @cite{LF} character (@cite{16#0A#}). @end itemize +@end quotation -@noindent -The line terminator sequence at the end of each line, including -the last line is a single @code{LF} character (@code{16#0A#}). -@sp 1 -@item -@cartouche -@noindent -Implementation-defined check names. See 11.5(27). -@end cartouche -@noindent +@itemize * + +@item +"Implementation-defined check names. See 11.5(27)." +@end itemize + The implementation defined check name Alignment_Check controls checking of address clause values for proper alignment (that is, the address supplied must be consistent with the alignment of the type). @@ -13344,119 +15243,117 @@ validity checks are generated. In addition, a user program can add implementation-defined check names by means of the pragma Check_Name. -@sp 1 -@item -@cartouche -@noindent -The interpretation of each aspect of representation. See -13.1(20). -@end cartouche -@noindent + +@itemize * + +@item +"The interpretation of each aspect of representation. See +13.1(20)." +@end itemize + See separate section on data representations. -@sp 1 -@item -@cartouche -@noindent -Any restrictions placed upon representation items. See -13.1(20). -@end cartouche -@noindent + +@itemize * + +@item +"Any restrictions placed upon representation items. See +13.1(20)." +@end itemize + See separate section on data representations. -@sp 1 -@item -@cartouche -@noindent -The meaning of @code{Size} for indefinite subtypes. See -13.3(48). -@end cartouche -@noindent + +@itemize * + +@item +"The meaning of @cite{Size} for indefinite subtypes. See +13.3(48)." +@end itemize + Size for an indefinite subtype is the maximum possible size, except that for the case of a subprogram parameter, the size of the parameter object is the actual size. -@sp 1 -@item -@cartouche -@noindent -The default external representation for a type tag. See -13.3(75). -@end cartouche -@noindent + +@itemize * + +@item +"The default external representation for a type tag. See +13.3(75)." +@end itemize + The default external representation for a type tag is the fully expanded name of the type in upper case letters. -@sp 1 -@item -@cartouche -@noindent -What determines whether a compilation unit is the same in -two different partitions. See 13.3(76). -@end cartouche -@noindent + +@itemize * + +@item +"What determines whether a compilation unit is the same in +two different partitions. See 13.3(76)." +@end itemize + A compilation unit is the same in two different partitions if and only if it derives from the same source file. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined components. See 13.5.1(15). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined components. See 13.5.1(15)." +@end itemize + The only implementation defined component is the tag for a tagged type, which contains a pointer to the dispatching table. -@sp 1 -@item -@cartouche -@noindent -If @code{Word_Size} = @code{Storage_Unit}, the default bit -ordering. See 13.5.3(5). -@end cartouche -@noindent -@code{Word_Size} (32) is not the same as @code{Storage_Unit} (8) for this + +@itemize * + +@item +"If @cite{Word_Size} = @cite{Storage_Unit}, the default bit +ordering. See 13.5.3(5)." +@end itemize + +@cite{Word_Size} (32) is not the same as @cite{Storage_Unit} (8) for this implementation, so no non-default bit ordering is supported. The default bit ordering corresponds to the natural endianness of the target architecture. -@sp 1 -@item -@cartouche -@noindent -The contents of the visible part of package @code{System} -and its language-defined children. See 13.7(2). -@end cartouche -@noindent -See the definition of these packages in files @file{system.ads} and -@file{s-stoele.ads}. Note that two declarations are added to package + +@itemize * + +@item +"The contents of the visible part of package @cite{System} +and its language-defined children. See 13.7(2)." +@end itemize + +See the definition of these packages in files @code{system.ads} and +@code{s-stoele.ads}. Note that two declarations are added to package System. -@smallexample @c ada - Max_Priority : constant Positive := - Priority'Last; - Max_Interrupt_Priority : constant Positive := - Interrupt_Priority'Last; -@end smallexample +@example +Max_Priority : constant Positive := Priority'Last; +Max_Interrupt_Priority : constant Positive := Interrupt_Priority'Last; +@end example + + +@itemize * + +@item +"The contents of the visible part of package +@cite{System.Machine_Code}, and the meaning of +@cite{code_statements}. See 13.8(7)." +@end itemize + +See the definition and documentation in file @code{s-maccod.ads}. + + +@itemize * + +@item +"The effect of unchecked conversion. See 13.9(11)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -The contents of the visible part of package -@code{System.Machine_Code}, and the meaning of -@code{code_statements}. See 13.8(7). -@end cartouche -@noindent -See the definition and documentation in file @file{s-maccod.ads}. - -@sp 1 -@item -@cartouche -@noindent -The effect of unchecked conversion. See 13.9(11). -@end cartouche -@noindent Unchecked conversion between types of the same size results in an uninterpreted transmission of the bits from one type to the other. If the types are of unequal sizes, then in the case of @@ -13471,1278 +15368,1500 @@ unconstrained array are not permitted. If the target alignment is greater than the source alignment, then a copy of the result is made with appropriate alignment -@sp 1 -@item -@cartouche -@noindent -The semantics of operations on invalid representations. -See 13.9.2(10-11). -@end cartouche -@noindent + +@itemize * + +@item +"The semantics of operations on invalid representations. +See 13.9.2(10-11)." +@end itemize + For assignments and other operations where the use of invalid values cannot result in erroneous behavior, the compiler ignores the possibility of invalid values. An exception is raised at the point where an invalid value would result in erroneous behavior. For example executing: -@smallexample @c ada +@example procedure invalidvals is - X : Integer := -1; - Y : Natural range 1 .. 10; - for Y'Address use X'Address; - Z : Natural range 1 .. 10; - A : array (Natural range 1 .. 10) of Integer; + X : Integer := -1; + Y : Natural range 1 .. 10; + for Y'Address use X'Address; + Z : Natural range 1 .. 10; + A : array (Natural range 1 .. 10) of Integer; begin - Z := Y; -- no exception - A (Z) := 3; -- exception raised; + Z := Y; -- no exception + A (Z) := 3; -- exception raised; end; -@end smallexample +@end example -@noindent As indicated, an exception is raised on the array assignment, but not on the simple assignment of the invalid negative value from Y to Z. -@sp 1 -@item -@cartouche -@noindent -The manner of choosing a storage pool for an access type -when @code{Storage_Pool} is not specified for the type. See 13.11(17). -@end cartouche -@noindent + +@itemize * + +@item +"The manner of choosing a storage pool for an access type +when @cite{Storage_Pool} is not specified for the type. See 13.11(17)." +@end itemize + There are 3 different standard pools used by the compiler when -@code{Storage_Pool} is not specified depending whether the type is local +@cite{Storage_Pool} is not specified depending whether the type is local to a subprogram or defined at the library level and whether -@code{Storage_Size}is specified or not. See documentation in the runtime -library units @code{System.Pool_Global}, @code{System.Pool_Size} and -@code{System.Pool_Local} in files @file{s-poosiz.ads}, -@file{s-pooglo.ads} and @file{s-pooloc.ads} for full details on the +@cite{Storage_Size`is specified or not. See documentation in the runtime library units `System.Pool_Global}, @cite{System.Pool_Size} and +@cite{System.Pool_Local} in files @code{s-poosiz.ads}, +@code{s-pooglo.ads} and @code{s-pooloc.ads} for full details on the default pools used. -@sp 1 -@item -@cartouche -@noindent -Whether or not the implementation provides user-accessible -names for the standard pool type(s). See 13.11(17). -@end cartouche -@noindent + +@itemize * + +@item +"Whether or not the implementation provides user-accessible +names for the standard pool type(s). See 13.11(17)." +@end itemize See documentation in the sources of the run time mentioned in the previous -paragraph. All these pools are accessible by means of @code{with}'ing +paragraph. All these pools are accessible by means of @cite{with}'ing these units. -@sp 1 -@item -@cartouche -@noindent -The meaning of @code{Storage_Size}. See 13.11(18). -@end cartouche -@noindent -@code{Storage_Size} is measured in storage units, and refers to the + +@itemize * + +@item +"The meaning of @cite{Storage_Size}. See 13.11(18)." +@end itemize + +@cite{Storage_Size} is measured in storage units, and refers to the total space available for an access type collection, or to the primary stack space for a task. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of storage pools. See -13.11(22). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined aspects of storage pools. See +13.11(22)." +@end itemize + See documentation in the sources of the run time mentioned in the paragraph about standard storage pools above for details on GNAT-defined aspects of storage pools. -@sp 1 -@item -@cartouche -@noindent -The set of restrictions allowed in a pragma -@code{Restrictions}. See 13.12(7). -@end cartouche -@noindent -@xref{Standard and Implementation Defined Restrictions}. - -@sp 1 -@item -@cartouche -@noindent -The consequences of violating limitations on -@code{Restrictions} pragmas. See 13.12(9). -@end cartouche -@noindent + +@itemize * + +@item +"The set of restrictions allowed in a pragma +@cite{Restrictions}. See 13.12(7)." +@end itemize + +See @ref{9,,Standard and Implementation Defined Restrictions}. + + +@itemize * + +@item +"The consequences of violating limitations on +@cite{Restrictions} pragmas. See 13.12(9)." +@end itemize + Restrictions that can be checked at compile time result in illegalities if violated. Currently there are no other consequences of violating restrictions. -@sp 1 -@item -@cartouche -@noindent -The representation used by the @code{Read} and -@code{Write} attributes of elementary types in terms of stream -elements. See 13.13.2(9). -@end cartouche -@noindent + +@itemize * + +@item +"The representation used by the @cite{Read} and +@cite{Write} attributes of elementary types in terms of stream +elements. See 13.13.2(9)." +@end itemize + The representation is the in-memory representation of the base type of the type, using the number of bits corresponding to the -@code{@var{type}'Size} value, and the natural ordering of the machine. +@code{type'Size} value, and the natural ordering of the machine. + + +@itemize * + +@item +"The names and characteristics of the numeric subtypes +declared in the visible part of package @cite{Standard}. See A.1(3)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -The names and characteristics of the numeric subtypes -declared in the visible part of package @code{Standard}. See A.1(3). -@end cartouche -@noindent See items describing the integer and floating-point types supported. -@sp 1 -@item -@cartouche -@noindent -The string returned by @code{Character_Set_Version}. -See A.3.5(3). -@end cartouche -@noindent -@code{Ada.Wide_Characters.Handling.Character_Set_Version} returns + +@itemize * + +@item +"The string returned by @cite{Character_Set_Version}. +See A.3.5(3)." +@end itemize + +@cite{Ada.Wide_Characters.Handling.Character_Set_Version} returns the string "Unicode 4.0", referring to version 4.0 of the Unicode specification. -@sp 1 -@item -@cartouche -@noindent -The accuracy actually achieved by the elementary -functions. See A.5.1(1). -@end cartouche -@noindent + +@itemize * + +@item +"The accuracy actually achieved by the elementary +functions. See A.5.1(1)." +@end itemize + The elementary functions correspond to the functions available in the C library. Only fast math mode is implemented. -@sp 1 -@item -@cartouche -@noindent -The sign of a zero result from some of the operators or -functions in @code{Numerics.Generic_Elementary_Functions}, when -@code{Float_Type'Signed_Zeros} is @code{True}. See A.5.1(46). -@end cartouche -@noindent + +@itemize * + +@item +"The sign of a zero result from some of the operators or +functions in @cite{Numerics.Generic_Elementary_Functions}, when +@cite{Float_Type'Signed_Zeros} is @cite{True}. See A.5.1(46)." +@end itemize + The sign of zeroes follows the requirements of the IEEE 754 standard on floating-point. -@sp 1 -@item -@cartouche -@noindent -The value of -@code{Numerics.Float_Random.Max_Image_Width}. See A.5.2(27). -@end cartouche -@noindent -Maximum image width is 6864, see library file @file{s-rannum.ads}. - -@sp 1 -@item -@cartouche -@noindent -The value of -@code{Numerics.Discrete_Random.Max_Image_Width}. See A.5.2(27). -@end cartouche -@noindent -Maximum image width is 6864, see library file @file{s-rannum.ads}. - -@sp 1 -@item -@cartouche -@noindent -The algorithms for random number generation. See -A.5.2(32). -@end cartouche -@noindent + +@itemize * + +@item +"The value of +@cite{Numerics.Float_Random.Max_Image_Width}. See A.5.2(27)." +@end itemize + +Maximum image width is 6864, see library file @code{s-rannum.ads}. + + +@itemize * + +@item +"The value of +@cite{Numerics.Discrete_Random.Max_Image_Width}. See A.5.2(27)." +@end itemize + +Maximum image width is 6864, see library file @code{s-rannum.ads}. + + +@itemize * + +@item +"The algorithms for random number generation. See +A.5.2(32)." +@end itemize + The algorithm is the Mersenne Twister, as documented in the source file -@file{s-rannum.adb}. This version of the algorithm has a period of +@code{s-rannum.adb}. This version of the algorithm has a period of 2**19937-1. -@sp 1 -@item -@cartouche -@noindent -The string representation of a random number generator's -state. See A.5.2(38). -@end cartouche -@noindent + +@itemize * + +@item +"The string representation of a random number generator's +state. See A.5.2(38)." +@end itemize + The value returned by the Image function is the concatenation of the fixed-width decimal representations of the 624 32-bit integers of the state vector. -@sp 1 -@item -@cartouche -@noindent -The minimum time interval between calls to the + +@itemize * + +@item +"The minimum time interval between calls to the time-dependent Reset procedure that are guaranteed to initiate different -random number sequences. See A.5.2(45). -@end cartouche -@noindent +random number sequences. See A.5.2(45)." +@end itemize + The minimum period between reset calls to guarantee distinct series of random numbers is one microsecond. -@sp 1 -@item -@cartouche -@noindent -The values of the @code{Model_Mantissa}, -@code{Model_Emin}, @code{Model_Epsilon}, @code{Model}, -@code{Safe_First}, and @code{Safe_Last} attributes, if the Numerics -Annex is not supported. See A.5.3(72). -@end cartouche -@noindent -Run the compiler with @option{-gnatS} to produce a listing of package -@code{Standard}, has the values of all numeric attributes. - -@sp 1 -@item -@cartouche -@noindent -Any implementation-defined characteristics of the -input-output packages. See A.7(14). -@end cartouche -@noindent + +@itemize * + +@item +"The values of the @cite{Model_Mantissa}, +@cite{Model_Emin}, @cite{Model_Epsilon}, @cite{Model}, +@cite{Safe_First}, and @cite{Safe_Last} attributes, if the Numerics +Annex is not supported. See A.5.3(72)." +@end itemize + +Run the compiler with @emph{-gnatS} to produce a listing of package +@cite{Standard}, has the values of all numeric attributes. + + +@itemize * + +@item +"Any implementation-defined characteristics of the +input-output packages. See A.7(14)." +@end itemize + There are no special implementation defined characteristics for these packages. -@sp 1 -@item -@cartouche -@noindent -The value of @code{Buffer_Size} in @code{Storage_IO}. See -A.9(10). -@end cartouche -@noindent -All type representations are contiguous, and the @code{Buffer_Size} is -the value of @code{@var{type}'Size} rounded up to the next storage unit + +@itemize * + +@item +"The value of @cite{Buffer_Size} in @cite{Storage_IO}. See +A.9(10)." +@end itemize + +All type representations are contiguous, and the @cite{Buffer_Size} is +the value of @code{type'Size} rounded up to the next storage unit boundary. -@sp 1 -@item -@cartouche -@noindent -External files for standard input, standard output, and -standard error See A.10(5). -@end cartouche -@noindent + +@itemize * + +@item +"External files for standard input, standard output, and +standard error See A.10(5)." +@end itemize + These files are mapped onto the files provided by the C streams -libraries. See source file @file{i-cstrea.ads} for further details. +libraries. See source file @code{i-cstrea.ads} for further details. + + +@itemize * + +@item +"The accuracy of the value produced by @cite{Put}. See +A.10.9(36)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -The accuracy of the value produced by @code{Put}. See -A.10.9(36). -@end cartouche -@noindent If more digits are requested in the output than are represented by the precision of the value, zeroes are output in the corresponding least significant digit positions. -@sp 1 -@item -@cartouche -@noindent -The meaning of @code{Argument_Count}, @code{Argument}, and -@code{Command_Name}. See A.15(1). -@end cartouche -@noindent -These are mapped onto the @code{argv} and @code{argc} parameters of the + +@itemize * + +@item +"The meaning of @cite{Argument_Count}, @cite{Argument}, and +@cite{Command_Name}. See A.15(1)." +@end itemize + +These are mapped onto the @cite{argv} and @cite{argc} parameters of the main program in the natural manner. -@sp 1 -@item -@cartouche -@noindent -The interpretation of the @code{Form} parameter in procedure -@code{Create_Directory}. See A.16(56). -@end cartouche -@noindent -The @code{Form} parameter is not used. - -@sp 1 -@item -@cartouche -@noindent -The interpretation of the @code{Form} parameter in procedure -@code{Create_Path}. See A.16(60). -@end cartouche -@noindent -The @code{Form} parameter is not used. - -@sp 1 -@item -@cartouche -@noindent -The interpretation of the @code{Form} parameter in procedure -@code{Copy_File}. See A.16(68). -@end cartouche -@noindent -The @code{Form} parameter is case-insensitive. -Two fields are recognized in the @code{Form} parameter: +@itemize * -@table @code +@item +"The interpretation of the @cite{Form} parameter in procedure +@cite{Create_Directory}. See A.16(56)." +@end itemize -@item preserve=<value> +The @cite{Form} parameter is not used. -@item mode=<value> -@end table +@itemize * + +@item +"The interpretation of the @cite{Form} parameter in procedure +@cite{Create_Path}. See A.16(60)." +@end itemize + +The @cite{Form} parameter is not used. + + +@itemize * + +@item +"The interpretation of the @cite{Form} parameter in procedure +@cite{Copy_File}. See A.16(68)." +@end itemize + +The @cite{Form} parameter is case-insensitive. +Two fields are recognized in the @cite{Form} parameter: + +@example +*preserve=<value>* +*mode=<value>* +@end example -@noindent <value> starts immediately after the character '=' and ends with the character immediately preceding the next comma (',') or with the last character of the parameter. The only possible values for preserve= are: -@table @code -@item no_attributes -Do not try to preserve any file attributes. This is the default if no -preserve= is found in Form. +@multitable {xxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} +@headitem + +Value + +@tab + +Meaning + +@item + +@emph{no_attributes} + +@tab + +Do not try to preserve any file attributes. This is the +default if no preserve= is found in Form. + +@item + +@emph{all_attributes} + +@tab -@item all_attributes Try to preserve all file attributes (timestamps, access rights). -@item timestamps -Preserve the timestamp of the copied file, but not the other file attributes. +@item + +@emph{timestamps} + +@tab + +Preserve the timestamp of the copied file, but not the other +file attributes. + +@end multitable -@end table -@noindent The only possible values for mode= are: -@table @code -@item copy -Only do the copy if the destination file does not already exist. If it already -exists, Copy_File fails. +@multitable {xxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} +@headitem + +Value + +@tab + +Meaning + +@item + +@emph{copy} + +@tab + +Only do the copy if the destination file does not already exist. +If it already exists, Copy_File fails. + +@item + +@emph{overwrite} + +@tab -@item overwrite Copy the file in all cases. Overwrite an already existing destination file. -@item append -Append the original file to the destination file. If the destination file does -not exist, the destination file is a copy of the source file. When mode=append, -the field preserve=, if it exists, is not taken into account. +@item + +@emph{append} + +@tab + +Append the original file to the destination file. If the destination file +does not exist, the destination file is a copy of the source file. +When mode=append, the field preserve=, if it exists, is not taken into account. + +@end multitable -@end table -@noindent If the Form parameter includes one or both of the fields and the value or values are incorrect, Copy_file fails with Use_Error. Examples of correct Forms: -@smallexample +@example Form => "preserve=no_attributes,mode=overwrite" (the default) Form => "mode=append" Form => "mode=copy, preserve=all_attributes" -@end smallexample +@end example -@noindent -Examples of incorrect Forms +Examples of incorrect Forms: -@smallexample +@example Form => "preserve=junk" Form => "mode=internal, preserve=timestamps" -@end smallexample +@end example -@sp 1 -@item -@cartouche -@noindent -The interpretation of the @code{Pattern} parameter, when not the null string, -in the @code{Start_Search} and @code{Search} procedures. -See A.16(104) and A.16(112). -@end cartouche -@noindent -When the @code{Pattern} parameter is not the null string, it is interpreted + +@itemize * + +@item +"The interpretation of the @cite{Pattern} parameter, when not the null string, +in the @cite{Start_Search} and @cite{Search} procedures. +See A.16(104) and A.16(112)." +@end itemize + +When the @cite{Pattern} parameter is not the null string, it is interpreted according to the syntax of regular expressions as defined in the -@code{GNAT.Regexp} package. -@xref{GNAT.Regexp (g-regexp.ads)}. +@cite{GNAT.Regexp} package. + +See @ref{1fd,,GNAT.Regexp (g-regexp.ads)}. + + +@itemize * + +@item +"Implementation-defined convention names. See B.1(11)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -Implementation-defined convention names. See B.1(11). -@end cartouche -@noindent The following convention names are supported -@table @code -@item Ada + +@multitable {xxxxxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} +@headitem + +Convention Name + +@tab + +Interpretation + +@item + +@emph{Ada} + +@tab + Ada -@item Ada_Pass_By_Copy + +@item + +@emph{Ada_Pass_By_Copy} + +@tab + Allowed for any types except by-reference types such as limited records. Compatible with convention Ada, but causes any parameters with this convention to be passed by copy. -@item Ada_Pass_By_Reference + +@item + +@emph{Ada_Pass_By_Reference} + +@tab + Allowed for any types except by-copy types such as scalars. Compatible with convention Ada, but causes any parameters with this convention to be passed by reference. -@item Assembler + +@item + +@emph{Assembler} + +@tab + Assembly language -@item Asm + +@item + +@emph{Asm} + +@tab + Synonym for Assembler -@item Assembly + +@item + +@emph{Assembly} + +@tab + Synonym for Assembler -@item C + +@item + +@emph{C} + +@tab + C -@item C_Pass_By_Copy + +@item + +@emph{C_Pass_By_Copy} + +@tab + Allowed only for record types, like C, but also notes that record is to be passed by copy rather than reference. -@item COBOL + +@item + +@emph{COBOL} + +@tab + COBOL -@item C_Plus_Plus (or CPP) + +@item + +@emph{C_Plus_Plus (or CPP)} + +@tab + C++ -@item Default + +@item + +@emph{Default} + +@tab + Treated the same as C -@item External + +@item + +@emph{External} + +@tab + Treated the same as C -@item Fortran + +@item + +@emph{Fortran} + +@tab + Fortran -@item Intrinsic -For support of pragma @code{Import} with convention Intrinsic, see + +@item + +@emph{Intrinsic} + +@tab + +For support of pragma @cite{Import} with convention Intrinsic, see separate section on Intrinsic Subprograms. -@item Stdcall + +@item + +@emph{Stdcall} + +@tab + Stdcall (used for Windows implementations only). This convention correspond to the WINAPI (previously called Pascal convention) C/C++ convention under Windows. A routine with this convention cleans the stack before exit. This pragma cannot be applied to a dispatching call. -@item DLL + +@item + +@emph{DLL} + +@tab + Synonym for Stdcall -@item Win32 + +@item + +@emph{Win32} + +@tab + Synonym for Stdcall -@item Stubbed + +@item + +@emph{Stubbed} + +@tab + Stubbed is a special convention used to indicate that the body of the subprogram will be entirely ignored. Any call to the subprogram -is converted into a raise of the @code{Program_Error} exception. If a -pragma @code{Import} specifies convention @code{stubbed} then no body need +is converted into a raise of the @cite{Program_Error} exception. If a +pragma @cite{Import} specifies convention @cite{stubbed} then no body need be present at all. This convention is useful during development for the inclusion of subprograms whose body has not yet been written. - -@end table -@noindent In addition, all otherwise unrecognized convention names are also -treated as being synonymous with convention C@. In all implementations +treated as being synonymous with convention C. In all implementations except for VMS, use of such other names results in a warning. In VMS implementations, these names are accepted silently. -@sp 1 -@item -@cartouche -@noindent -The meaning of link names. See B.1(36). -@end cartouche -@noindent +@end multitable + + + +@itemize * + +@item +"The meaning of link names. See B.1(36)." +@end itemize + Link names are the actual names used by the linker. -@sp 1 -@item -@cartouche -@noindent -The manner of choosing link names when neither the link + +@itemize * + +@item +"The manner of choosing link names when neither the link name nor the address of an imported or exported entity is specified. See -B.1(36). -@end cartouche -@noindent +B.1(36)." +@end itemize + The default linker name is that which would be assigned by the relevant external language, interpreting the Ada name as being in all lower case letters. -@sp 1 -@item -@cartouche -@noindent -The effect of pragma @code{Linker_Options}. See B.1(37). -@end cartouche -@noindent -The string passed to @code{Linker_Options} is presented uninterpreted as + +@itemize * + +@item +"The effect of pragma @cite{Linker_Options}. See B.1(37)." +@end itemize + +The string passed to @cite{Linker_Options} is presented uninterpreted as an argument to the link command, unless it contains ASCII.NUL characters. NUL characters if they appear act as argument separators, so for example -@smallexample @c ada +@example pragma Linker_Options ("-labc" & ASCII.NUL & "-ldef"); -@end smallexample +@end example -@noindent -causes two separate arguments @code{-labc} and @code{-ldef} to be passed to the +causes two separate arguments @cite{-labc} and @cite{-ldef} to be passed to the linker. The order of linker options is preserved for a given unit. The final list of options passed to the linker is in reverse order of the elaboration order. For example, linker options for a body always appear before the options from the corresponding package spec. -@sp 1 -@item -@cartouche -@noindent -The contents of the visible part of package -@code{Interfaces} and its language-defined descendants. See B.2(1). -@end cartouche -@noindent -See files with prefix @file{i-} in the distributed library. - -@sp 1 -@item -@cartouche -@noindent -Implementation-defined children of package -@code{Interfaces}. The contents of the visible part of package -@code{Interfaces}. See B.2(11). -@end cartouche -@noindent -See files with prefix @file{i-} in the distributed library. - -@sp 1 + +@itemize * + +@item +"The contents of the visible part of package +@cite{Interfaces} and its language-defined descendants. See B.2(1)." +@end itemize + +See files with prefix @code{i-} in the distributed library. + + +@itemize * + +@item +"Implementation-defined children of package +@cite{Interfaces}. The contents of the visible part of package +@cite{Interfaces}. See B.2(11)." +@end itemize + +See files with prefix @code{i-} in the distributed library. + + +@itemize * + +@item +"The types @cite{Floating}, @cite{Long_Floating}, +@cite{Binary}, @cite{Long_Binary}, @cite{Decimal_ Element}, and +@cite{COBOL_Character}; and the initialization of the variables +@cite{Ada_To_COBOL} and @cite{COBOL_To_Ada}, in +@cite{Interfaces.COBOL}. See B.4(50)." +@end itemize + + +@multitable {xxxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} +@headitem + +COBOL + +@tab + +Ada + @item -@cartouche -@noindent -The types @code{Floating}, @code{Long_Floating}, -@code{Binary}, @code{Long_Binary}, @code{Decimal_ Element}, and -@code{COBOL_Character}; and the initialization of the variables -@code{Ada_To_COBOL} and @code{COBOL_To_Ada}, in -@code{Interfaces.COBOL}. See B.4(50). -@end cartouche -@noindent -@table @code -@item Floating + +@emph{Floating} + +@tab + Float -@item Long_Floating + +@item + +@emph{Long_Floating} + +@tab + (Floating) Long_Float -@item Binary + +@item + +@emph{Binary} + +@tab + Integer -@item Long_Binary + +@item + +@emph{Long_Binary} + +@tab + Long_Long_Integer -@item Decimal_Element + +@item + +@emph{Decimal_Element} + +@tab + Character -@item COBOL_Character + +@item + +@emph{COBOL_Character} + +@tab + Character -@end table -@noindent -For initialization, see the file @file{i-cobol.ads} in the distributed library. +@end multitable + + +For initialization, see the file @code{i-cobol.ads} in the distributed library. + + +@itemize * + +@item +"Support for access to machine instructions. See C.1(1)." +@end itemize + +See documentation in file @code{s-maccod.ads} in the distributed library. + + +@itemize * + +@item +"Implementation-defined aspects of access to machine +operations. See C.1(9)." +@end itemize + +See documentation in file @code{s-maccod.ads} in the distributed library. + + +@itemize * + +@item +"Implementation-defined aspects of interrupts. See C.3(2)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -Support for access to machine instructions. See C.1(1). -@end cartouche -@noindent -See documentation in file @file{s-maccod.ads} in the distributed library. - -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of access to machine -operations. See C.1(9). -@end cartouche -@noindent -See documentation in file @file{s-maccod.ads} in the distributed library. - -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of interrupts. See C.3(2). -@end cartouche -@noindent Interrupts are mapped to signals or conditions as appropriate. See definition of unit -@code{Ada.Interrupt_Names} in source file @file{a-intnam.ads} for details +@cite{Ada.Interrupt_Names} in source file @code{a-intnam.ads} for details on the interrupts supported on a particular target. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of pre-elaboration. See -C.4(13). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined aspects of pre-elaboration. See +C.4(13)." +@end itemize + GNAT does not permit a partition to be restarted without reloading, except under control of the debugger. -@sp 1 -@item -@cartouche -@noindent -The semantics of pragma @code{Discard_Names}. See C.5(7). -@end cartouche -@noindent -Pragma @code{Discard_Names} causes names of enumeration literals to + +@itemize * + +@item +"The semantics of pragma @cite{Discard_Names}. See C.5(7)." +@end itemize + +Pragma @cite{Discard_Names} causes names of enumeration literals to be suppressed. In the presence of this pragma, the Image attribute provides the image of the Pos of the literal, and Value accepts Pos values. -@sp 1 -@item -@cartouche -@noindent -The result of the @code{Task_Identification.Image} -attribute. See C.7.1(7). -@end cartouche -@noindent + +@itemize * + +@item +"The result of the @cite{Task_Identification.Image} +attribute. See C.7.1(7)." +@end itemize + The result of this attribute is a string that identifies -the object or component that denotes a given task. If a variable @code{Var} -has a task type, the image for this task will have the form @code{Var_@var{XXXXXXXX}}, +the object or component that denotes a given task. If a variable @cite{Var} +has a task type, the image for this task will have the form @cite{Var_`XXXXXXXX`}, where the suffix is the hexadecimal representation of the virtual address of the corresponding task control block. If the variable is an array of tasks, the image of each task will have the form of an indexed component indicating the position of a -given task in the array, e.g.@: @code{Group(5)_@var{XXXXXXX}}. If the task is a +given task in the array, e.g., @cite{Group(5)_`XXXXXXX`}. If the task is a component of a record, the image of the task will have the form of a selected component. These rules are fully recursive, so that the image of a task that is a subcomponent of a composite object corresponds to the expression that designates this task. -@noindent + If a task is created by an allocator, its image depends on the context. If the allocator is part of an object declaration, the rules described above are used to construct its image, and this image is not affected by subsequent assignments. If the allocator appears within an expression, the image includes only the name of the task type. -@noindent + If the configuration pragma Discard_Names is present, or if the restriction No_Implicit_Heap_Allocation is in effect, the image reduces to the numeric suffix, that is to say the hexadecimal representation of the virtual address of the control block of the task. -@sp 1 -@item -@cartouche -@noindent -The value of @code{Current_Task} when in a protected entry -or interrupt handler. See C.7.1(17). -@end cartouche -@noindent + + +@itemize * + +@item +"The value of @cite{Current_Task} when in a protected entry +or interrupt handler. See C.7.1(17)." +@end itemize + Protected entries or interrupt handlers can be executed by any -convenient thread, so the value of @code{Current_Task} is undefined. +convenient thread, so the value of @cite{Current_Task} is undefined. -@sp 1 -@item -@cartouche -@noindent -The effect of calling @code{Current_Task} from an entry -body or interrupt handler. See C.7.1(19). -@end cartouche -@noindent -The effect of calling @code{Current_Task} from an entry body or + +@itemize * + +@item +"The effect of calling @cite{Current_Task} from an entry +body or interrupt handler. See C.7.1(19)." +@end itemize + +The effect of calling @cite{Current_Task} from an entry body or interrupt handler is to return the identification of the task currently executing the code. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of -@code{Task_Attributes}. See C.7.2(19). -@end cartouche -@noindent -There are no implementation-defined aspects of @code{Task_Attributes}. - -@sp 1 -@item -@cartouche -@noindent -Values of all @code{Metrics}. See D(2). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined aspects of +@cite{Task_Attributes}. See C.7.2(19)." +@end itemize + +There are no implementation-defined aspects of @cite{Task_Attributes}. + + +@itemize * + +@item +"Values of all @cite{Metrics}. See D(2)." +@end itemize + The metrics information for GNAT depends on the performance of the underlying operating system. The sources of the run-time for tasking -implementation, together with the output from @option{-gnatG} can be +implementation, together with the output from @emph{-gnatG} can be used to determine the exact sequence of operating systems calls made to implement various tasking constructs. Together with appropriate information on the performance of the underlying operating system, on the exact target in use, this information can be used to determine the required metrics. -@sp 1 -@item -@cartouche -@noindent -The declarations of @code{Any_Priority} and -@code{Priority}. See D.1(11). -@end cartouche -@noindent -See declarations in file @file{system.ads}. - -@sp 1 -@item -@cartouche -@noindent -Implementation-defined execution resources. See D.1(15). -@end cartouche -@noindent + +@itemize * + +@item +"The declarations of @cite{Any_Priority} and +@cite{Priority}. See D.1(11)." +@end itemize + +See declarations in file @code{system.ads}. + + +@itemize * + +@item +"Implementation-defined execution resources. See D.1(15)." +@end itemize + There are no implementation-defined execution resources. -@sp 1 -@item -@cartouche -@noindent -Whether, on a multiprocessor, a task that is waiting for -access to a protected object keeps its processor busy. See D.2.1(3). -@end cartouche -@noindent + +@itemize * + +@item +"Whether, on a multiprocessor, a task that is waiting for +access to a protected object keeps its processor busy. See D.2.1(3)." +@end itemize + On a multi-processor, a task that is waiting for access to a protected object does not keep its processor busy. -@sp 1 -@item -@cartouche -@noindent -The affect of implementation defined execution resources -on task dispatching. See D.2.1(9). -@end cartouche -@noindent -Tasks map to threads in the threads package used by GNAT@. Where possible + +@itemize * + +@item +"The affect of implementation defined execution resources +on task dispatching. See D.2.1(9)." +@end itemize + +Tasks map to threads in the threads package used by GNAT. Where possible and appropriate, these threads correspond to native threads of the underlying operating system. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined @code{policy_identifiers} allowed -in a pragma @code{Task_Dispatching_Policy}. See D.2.2(3). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined @cite{policy_identifiers} allowed +in a pragma @cite{Task_Dispatching_Policy}. See D.2.2(3)." +@end itemize + There are no implementation-defined policy-identifiers allowed in this pragma. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of priority inversion. See -D.2.2(16). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined aspects of priority inversion. See +D.2.2(16)." +@end itemize + Execution of a task cannot be preempted by the implementation processing of delay expirations for lower priority tasks. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined task dispatching. See D.2.2(18). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined task dispatching. See D.2.2(18)." +@end itemize + The policy is the same as that of the underlying threads implementation. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined @code{policy_identifiers} allowed -in a pragma @code{Locking_Policy}. See D.3(4). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined @cite{policy_identifiers} allowed +in a pragma @cite{Locking_Policy}. See D.3(4)." +@end itemize + The two implementation defined policies permitted in GNAT are -@code{Inheritance_Locking} and @code{Conccurent_Readers_Locking}. On -targets that support the @code{Inheritance_Locking} policy, locking is -implemented by inheritance, i.e.@: the task owning the lock operates +@cite{Inheritance_Locking} and @cite{Conccurent_Readers_Locking}. On +targets that support the @cite{Inheritance_Locking} policy, locking is +implemented by inheritance, i.e., the task owning the lock operates at a priority equal to the highest priority of any task currently requesting the lock. On targets that support the -@code{Conccurent_Readers_Locking} policy, locking is implemented with a +@cite{Conccurent_Readers_Locking} policy, locking is implemented with a read/write lock allowing multiple propected object functions to enter concurrently. -@sp 1 -@item -@cartouche -@noindent -Default ceiling priorities. See D.3(10). -@end cartouche -@noindent + +@itemize * + +@item +"Default ceiling priorities. See D.3(10)." +@end itemize + The ceiling priority of protected objects of the type -@code{System.Interrupt_Priority'Last} as described in the Ada +@cite{System.Interrupt_Priority'Last} as described in the Ada Reference Manual D.3(10), -@sp 1 -@item -@cartouche -@noindent -The ceiling of any protected object used internally by -the implementation. See D.3(16). -@end cartouche -@noindent + +@itemize * + +@item +"The ceiling of any protected object used internally by +the implementation. See D.3(16)." +@end itemize + The ceiling priority of internal protected objects is -@code{System.Priority'Last}. +@cite{System.Priority'Last}. + + +@itemize * + +@item +"Implementation-defined queuing policies. See D.4(1)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -Implementation-defined queuing policies. See D.4(1). -@end cartouche -@noindent There are no implementation-defined queuing policies. -@sp 1 -@item -@cartouche -@noindent -On a multiprocessor, any conditions that cause the + +@itemize * + +@item +"On a multiprocessor, any conditions that cause the completion of an aborted construct to be delayed later than what is -specified for a single processor. See D.6(3). -@end cartouche -@noindent +specified for a single processor. See D.6(3)." +@end itemize + The semantics for abort on a multi-processor is the same as on a single processor, there are no further delays. -@sp 1 -@item -@cartouche -@noindent -Any operations that implicitly require heap storage -allocation. See D.7(8). -@end cartouche -@noindent + +@itemize * + +@item +"Any operations that implicitly require heap storage +allocation. See D.7(8)." +@end itemize + The only operation that implicitly requires heap storage allocation is task creation. -@sp 1 -@item -@cartouche -@noindent -What happens when a task terminates in the presence of -pragma @code{No_Task_Termination}. See D.7(15). -@end cartouche -@noindent + +@itemize * + +@item +"What happens when a task terminates in the presence of +pragma @cite{No_Task_Termination}. See D.7(15)." +@end itemize + Execution is erroneous in that case. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of pragma -@code{Restrictions}. See D.7(20). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined aspects of pragma +@cite{Restrictions}. See D.7(20)." +@end itemize + There are no such implementation-defined aspects. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of package -@code{Real_Time}. See D.8(17). -@end cartouche -@noindent -There are no implementation defined aspects of package @code{Real_Time}. - -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of -@code{delay_statements}. See D.9(8). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined aspects of package +@cite{Real_Time}. See D.8(17)." +@end itemize + +There are no implementation defined aspects of package @cite{Real_Time}. + + +@itemize * + +@item +"Implementation-defined aspects of +@cite{delay_statements}. See D.9(8)." +@end itemize + Any difference greater than one microsecond will cause the task to be delayed (see D.9(7)). -@sp 1 -@item -@cartouche -@noindent -The upper bound on the duration of interrupt blocking -caused by the implementation. See D.12(5). -@end cartouche -@noindent + +@itemize * + +@item +"The upper bound on the duration of interrupt blocking +caused by the implementation. See D.12(5)." +@end itemize + The upper bound is determined by the underlying operating system. In no cases is it more than 10 milliseconds. -@sp 1 -@item -@cartouche -@noindent -The means for creating and executing distributed -programs. See E(5). -@end cartouche -@noindent + +@itemize * + +@item +"The means for creating and executing distributed +programs. See E(5)." +@end itemize + The GLADE package provides a utility GNATDIST for creating and executing distributed programs. See the GLADE reference manual for further details. -@sp 1 -@item -@cartouche -@noindent -Any events that can result in a partition becoming -inaccessible. See E.1(7). -@end cartouche -@noindent + +@itemize * + +@item +"Any events that can result in a partition becoming +inaccessible. See E.1(7)." +@end itemize + See the GLADE reference manual for full details on such events. -@sp 1 -@item -@cartouche -@noindent -The scheduling policies, treatment of priorities, and + +@itemize * + +@item +"The scheduling policies, treatment of priorities, and management of shared resources between partitions in certain cases. See -E.1(11). -@end cartouche -@noindent +E.1(11)." +@end itemize + See the GLADE reference manual for full details on these aspects of multi-partition execution. -@sp 1 -@item -@cartouche -@noindent -Events that cause the version of a compilation unit to -change. See E.3(5). -@end cartouche -@noindent + +@itemize * + +@item +"Events that cause the version of a compilation unit to +change. See E.3(5)." +@end itemize + Editing the source file of a compilation unit, or the source files of any units on which it is dependent in a significant way cause the version to change. No other actions cause the version number to change. All changes are significant except those which affect only layout, capitalization or comments. -@sp 1 -@item -@cartouche -@noindent -Whether the execution of the remote subprogram is -immediately aborted as a result of cancellation. See E.4(13). -@end cartouche -@noindent + +@itemize * + +@item +"Whether the execution of the remote subprogram is +immediately aborted as a result of cancellation. See E.4(13)." +@end itemize + See the GLADE reference manual for details on the effect of abort in a distributed application. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of the PCS@. See E.5(25). -@end cartouche -@noindent + +@itemize * + +@item +"Implementation-defined aspects of the PCS. See E.5(25)." +@end itemize + See the GLADE reference manual for a full description of all implementation -defined aspects of the PCS@. +defined aspects of the PCS. + + +@itemize * + +@item +"Implementation-defined interfaces in the PCS. See +E.5(26)." +@end itemize -@sp 1 -@item -@cartouche -@noindent -Implementation-defined interfaces in the PCS@. See -E.5(26). -@end cartouche -@noindent See the GLADE reference manual for a full description of all implementation defined interfaces. -@sp 1 + +@itemize * + +@item +"The values of named numbers in the package +@cite{Decimal}. See F.2(7)." +@end itemize + + +@multitable {xxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxx} +@headitem + +Named Number + +@tab + +Value + @item -@cartouche -@noindent -The values of named numbers in the package -@code{Decimal}. See F.2(7). -@end cartouche -@noindent -@table @code -@item Max_Scale + +@emph{Max_Scale} + +@tab + +18 -@item Min_Scale + +@item + +@emph{Min_Scale} + +@tab + -18 -@item Min_Delta + +@item + +@emph{Min_Delta} + +@tab + 1.0E-18 -@item Max_Delta + +@item + +@emph{Max_Delta} + +@tab + 1.0E+18 -@item Max_Decimal_Digits -18 -@end table -@sp 1 @item -@cartouche -@noindent -The value of @code{Max_Picture_Length} in the package -@code{Text_IO.Editing}. See F.3.3(16). -@end cartouche -@noindent + +@emph{Max_Decimal_Digits} + +@tab + +18 + +@end multitable + + + +@itemize * + +@item +"The value of @cite{Max_Picture_Length} in the package +@cite{Text_IO.Editing}. See F.3.3(16)." +@end itemize + 64 -@sp 1 -@item -@cartouche -@noindent -The value of @code{Max_Picture_Length} in the package -@code{Wide_Text_IO.Editing}. See F.3.4(5). -@end cartouche -@noindent + +@itemize * + +@item +"The value of @cite{Max_Picture_Length} in the package +@cite{Wide_Text_IO.Editing}. See F.3.4(5)." +@end itemize + 64 -@sp 1 -@item -@cartouche -@noindent -The accuracy actually achieved by the complex elementary -functions and by other complex arithmetic operations. See G.1(1). -@end cartouche -@noindent + +@itemize * + +@item +"The accuracy actually achieved by the complex elementary +functions and by other complex arithmetic operations. See G.1(1)." +@end itemize + Standard library functions are used for the complex arithmetic operations. Only fast math mode is currently supported. -@sp 1 -@item -@cartouche -@noindent -The sign of a zero result (or a component thereof) from -any operator or function in @code{Numerics.Generic_Complex_Types}, when -@code{Real'Signed_Zeros} is True. See G.1.1(53). -@end cartouche -@noindent + +@itemize * + +@item +"The sign of a zero result (or a component thereof) from +any operator or function in @cite{Numerics.Generic_Complex_Types}, when +@cite{Real'Signed_Zeros} is True. See G.1.1(53)." +@end itemize + The signs of zero values are as recommended by the relevant implementation advice. -@sp 1 -@item -@cartouche -@noindent -The sign of a zero result (or a component thereof) from + +@itemize * + +@item +"The sign of a zero result (or a component thereof) from any operator or function in -@code{Numerics.Generic_Complex_Elementary_Functions}, when -@code{Real'Signed_Zeros} is @code{True}. See G.1.2(45). -@end cartouche -@noindent +@cite{Numerics.Generic_Complex_Elementary_Functions}, when +@cite{Real'Signed_Zeros} is @cite{True}. See G.1.2(45)." +@end itemize + The signs of zero values are as recommended by the relevant implementation advice. -@sp 1 -@item -@cartouche -@noindent -Whether the strict mode or the relaxed mode is the -default. See G.2(2). -@end cartouche -@noindent + +@itemize * + +@item +"Whether the strict mode or the relaxed mode is the +default. See G.2(2)." +@end itemize + The strict mode is the default. There is no separate relaxed mode. GNAT provides a highly efficient implementation of strict mode. -@sp 1 -@item -@cartouche -@noindent -The result interval in certain cases of fixed-to-float -conversion. See G.2.1(10). -@end cartouche -@noindent + +@itemize * + +@item +"The result interval in certain cases of fixed-to-float +conversion. See G.2.1(10)." +@end itemize + For cases where the result interval is implementation dependent, the accuracy is that provided by performing all operations in 64-bit IEEE floating-point format. -@sp 1 -@item -@cartouche -@noindent -The result of a floating point arithmetic operation in -overflow situations, when the @code{Machine_Overflows} attribute of the -result type is @code{False}. See G.2.1(13). -@end cartouche -@noindent + +@itemize * + +@item +"The result of a floating point arithmetic operation in +overflow situations, when the @cite{Machine_Overflows} attribute of the +result type is @cite{False}. See G.2.1(13)." +@end itemize + Infinite and NaN values are produced as dictated by the IEEE floating-point standard. - Note that on machines that are not fully compliant with the IEEE -floating-point standard, such as Alpha, the @option{-mieee} compiler flag +floating-point standard, such as Alpha, the @emph{-mieee} compiler flag must be used for achieving IEEE conforming behavior (although at the cost of a significant performance penalty), so infinite and NaN values are properly generated. -@sp 1 -@item -@cartouche -@noindent -The result interval for division (or exponentiation by a + +@itemize * + +@item +"The result interval for division (or exponentiation by a negative exponent), when the floating point hardware implements division -as multiplication by a reciprocal. See G.2.1(16). -@end cartouche -@noindent +as multiplication by a reciprocal. See G.2.1(16)." +@end itemize + Not relevant, division is IEEE exact. -@sp 1 -@item -@cartouche -@noindent -The definition of close result set, which determines the + +@itemize * + +@item +"The definition of close result set, which determines the accuracy of certain fixed point multiplications and divisions. See -G.2.3(5). -@end cartouche -@noindent +G.2.3(5)." +@end itemize + Operations in the close result set are performed using IEEE long format floating-point arithmetic. The input operands are converted to floating-point, the operation is done in floating-point, and the result is converted to the target type. -@sp 1 -@item -@cartouche -@noindent -Conditions on a @code{universal_real} operand of a fixed + +@itemize * + +@item +"Conditions on a @cite{universal_real} operand of a fixed point multiplication or division for which the result shall be in the -perfect result set. See G.2.3(22). -@end cartouche -@noindent +perfect result set. See G.2.3(22)." +@end itemize + The result is only defined to be in the perfect result set if the result can be computed by a single scaling operation involving a scale factor representable in 64-bits. -@sp 1 -@item -@cartouche -@noindent -The result of a fixed point arithmetic operation in -overflow situations, when the @code{Machine_Overflows} attribute of the -result type is @code{False}. See G.2.3(27). -@end cartouche -@noindent -Not relevant, @code{Machine_Overflows} is @code{True} for fixed-point + +@itemize * + +@item +"The result of a fixed point arithmetic operation in +overflow situations, when the @cite{Machine_Overflows} attribute of the +result type is @cite{False}. See G.2.3(27)." +@end itemize + +Not relevant, @cite{Machine_Overflows} is @cite{True} for fixed-point types. -@sp 1 -@item -@cartouche -@noindent -The result of an elementary function reference in -overflow situations, when the @code{Machine_Overflows} attribute of the -result type is @code{False}. See G.2.4(4). -@end cartouche -@noindent + +@itemize * + +@item +"The result of an elementary function reference in +overflow situations, when the @cite{Machine_Overflows} attribute of the +result type is @cite{False}. See G.2.4(4)." +@end itemize + IEEE infinite and Nan values are produced as appropriate. -@sp 1 -@item -@cartouche -@noindent -The value of the angle threshold, within which certain + +@itemize * + +@item +"The value of the angle threshold, within which certain elementary functions, complex arithmetic operations, and complex elementary functions yield results conforming to a maximum relative -error bound. See G.2.4(10). -@end cartouche -@noindent +error bound. See G.2.4(10)." +@end itemize + Information on this subject is not yet available. -@sp 1 -@item -@cartouche -@noindent -The accuracy of certain elementary functions for -parameters beyond the angle threshold. See G.2.4(10). -@end cartouche -@noindent + +@itemize * + +@item +"The accuracy of certain elementary functions for +parameters beyond the angle threshold. See G.2.4(10)." +@end itemize + Information on this subject is not yet available. -@sp 1 -@item -@cartouche -@noindent -The result of a complex arithmetic operation or complex + +@itemize * + +@item +"The result of a complex arithmetic operation or complex elementary function reference in overflow situations, when the -@code{Machine_Overflows} attribute of the corresponding real type is -@code{False}. See G.2.6(5). -@end cartouche -@noindent +@cite{Machine_Overflows} attribute of the corresponding real type is +@cite{False}. See G.2.6(5)." +@end itemize + IEEE infinite and Nan values are produced as appropriate. -@sp 1 -@item -@cartouche -@noindent -The accuracy of certain complex arithmetic operations and + +@itemize * + +@item +"The accuracy of certain complex arithmetic operations and certain complex elementary functions for parameters (or components -thereof) beyond the angle threshold. See G.2.6(8). -@end cartouche -@noindent +thereof) beyond the angle threshold. See G.2.6(8)." +@end itemize + Information on those subjects is not yet available. -@sp 1 -@item -@cartouche -@noindent -Information regarding bounded errors and erroneous -execution. See H.2(1). -@end cartouche -@noindent + +@itemize * + +@item +"Information regarding bounded errors and erroneous +execution. See H.2(1)." +@end itemize + Information on this subject is not yet available. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of pragma -@code{Inspection_Point}. See H.3.2(8). -@end cartouche -@noindent -Pragma @code{Inspection_Point} ensures that the variable is live and can + +@itemize * + +@item +"Implementation-defined aspects of pragma +@cite{Inspection_Point}. See H.3.2(8)." +@end itemize + +Pragma @cite{Inspection_Point} ensures that the variable is live and can be examined by the debugger at the inspection point. -@sp 1 -@item -@cartouche -@noindent -Implementation-defined aspects of pragma -@code{Restrictions}. See H.4(25). -@end cartouche -@noindent -There are no implementation-defined aspects of pragma @code{Restrictions}. The -use of pragma @code{Restrictions [No_Exceptions]} has no effect on the -generated code. Checks must suppressed by use of pragma @code{Suppress}. - -@sp 1 -@item -@cartouche -@noindent -Any restrictions on pragma @code{Restrictions}. See -H.4(27). -@end cartouche -@noindent -There are no restrictions on pragma @code{Restrictions}. +@itemize * + +@item +"Implementation-defined aspects of pragma +@cite{Restrictions}. See H.4(25)." +@end itemize + +There are no implementation-defined aspects of pragma @cite{Restrictions}. The +use of pragma @cite{Restrictions [No_Exceptions]} has no effect on the +generated code. Checks must suppressed by use of pragma @cite{Suppress}. + + +@itemize * + +@item +"Any restrictions on pragma @cite{Restrictions}. See +H.4(27)." @end itemize +There are no restrictions on pragma @cite{Restrictions}. -@c ======================= -@node Intrinsic Subprograms +@node Intrinsic Subprograms,Representation Clauses and Pragmas,Implementation Defined Characteristics,Top +@anchor{gnat_rm/intrinsic_subprograms doc}@anchor{1fe}@anchor{gnat_rm/intrinsic_subprograms intrinsic-subprograms}@anchor{c}@anchor{gnat_rm/intrinsic_subprograms id1}@anchor{1ff} @chapter Intrinsic Subprograms -@cindex Intrinsic Subprograms -@menu -* Intrinsic Operators:: -* Compilation_Date:: -* Compilation_Time:: -* Enclosing_Entity:: -* Exception_Information:: -* Exception_Message:: -* Exception_Name:: -* File:: -* Line:: -* Shifts and Rotates:: -* Source_Location:: -@end menu -@noindent +@geindex Intrinsic Subprograms + GNAT allows a user application program to write the declaration: -@smallexample @c ada - pragma Import (Intrinsic, name); -@end smallexample +@example +pragma Import (Intrinsic, name); +@end example -@noindent providing that the name corresponds to one of the implemented intrinsic subprograms in GNAT, and that the parameter profile of the referenced subprogram meets the requirements. This chapter describes the set of @@ -14752,150 +16871,196 @@ body is supplied elsewhere (in this case by the compiler itself). Note that any use of this feature is potentially non-portable, since the Ada standard does not require Ada compilers to implement this feature. -@node Intrinsic Operators +@menu +* Intrinsic Operators:: +* Compilation_Date:: +* Compilation_Time:: +* Enclosing_Entity:: +* Exception_Information:: +* Exception_Message:: +* Exception_Name:: +* File:: +* Line:: +* Shifts and Rotates:: +* Source_Location:: + +@end menu + +@node Intrinsic Operators,Compilation_Date,,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms id2}@anchor{200}@anchor{gnat_rm/intrinsic_subprograms intrinsic-operators}@anchor{201} @section Intrinsic Operators -@cindex Intrinsic operator -@noindent + +@geindex Intrinsic operator + All the predefined numeric operators in package Standard -in @code{pragma Import (Intrinsic,..)} +in @cite{pragma Import (Intrinsic@comma{}..)} declarations. In the binary operator case, the operands must have the same size. The operand or operands must also be appropriate for the operator. For example, for addition, the operands must both be floating-point or both be fixed-point, and the -right operand for @code{"**"} must have a root type of -@code{Standard.Integer'Base}. +right operand for @cite{"**"} must have a root type of +@cite{Standard.Integer'Base}. You can use an intrinsic operator declaration as in the following example: -@smallexample @c ada - type Int1 is new Integer; - type Int2 is new Integer; +@example +type Int1 is new Integer; +type Int2 is new Integer; - function "+" (X1 : Int1; X2 : Int2) return Int1; - function "+" (X1 : Int1; X2 : Int2) return Int2; - pragma Import (Intrinsic, "+"); -@end smallexample +function "+" (X1 : Int1; X2 : Int2) return Int1; +function "+" (X1 : Int1; X2 : Int2) return Int2; +pragma Import (Intrinsic, "+"); +@end example -@noindent -This declaration would permit ``mixed mode'' arithmetic on items -of the differing types @code{Int1} and @code{Int2}. +This declaration would permit 'mixed mode' arithmetic on items +of the differing types @cite{Int1} and @cite{Int2}. It is also possible to specify such operators for private types, if the full views are appropriate arithmetic types. -@node Compilation_Date +@node Compilation_Date,Compilation_Time,Intrinsic Operators,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms compilation-date}@anchor{202}@anchor{gnat_rm/intrinsic_subprograms id3}@anchor{203} @section Compilation_Date -@cindex Compilation_Date -@noindent + + +@geindex Compilation_Date + This intrinsic subprogram is used in the implementation of the -library package @code{GNAT.Source_Info}. The only useful use of the +library package @cite{GNAT.Source_Info}. The only useful use of the intrinsic import in this case is the one in this unit, so an application program should simply call the function -@code{GNAT.Source_Info.Compilation_Date} to obtain the date of +@cite{GNAT.Source_Info.Compilation_Date} to obtain the date of the current compilation (in local time format MMM DD YYYY). -@node Compilation_Time +@node Compilation_Time,Enclosing_Entity,Compilation_Date,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms compilation-time}@anchor{204}@anchor{gnat_rm/intrinsic_subprograms id4}@anchor{205} @section Compilation_Time -@cindex Compilation_Time -@noindent + + +@geindex Compilation_Time + This intrinsic subprogram is used in the implementation of the -library package @code{GNAT.Source_Info}. The only useful use of the +library package @cite{GNAT.Source_Info}. The only useful use of the intrinsic import in this case is the one in this unit, so an application program should simply call the function -@code{GNAT.Source_Info.Compilation_Time} to obtain the time of +@cite{GNAT.Source_Info.Compilation_Time} to obtain the time of the current compilation (in local time format HH:MM:SS). -@node Enclosing_Entity +@node Enclosing_Entity,Exception_Information,Compilation_Time,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms id5}@anchor{206}@anchor{gnat_rm/intrinsic_subprograms enclosing-entity}@anchor{207} @section Enclosing_Entity -@cindex Enclosing_Entity -@noindent + + +@geindex Enclosing_Entity + This intrinsic subprogram is used in the implementation of the -library package @code{GNAT.Source_Info}. The only useful use of the +library package @cite{GNAT.Source_Info}. The only useful use of the intrinsic import in this case is the one in this unit, so an application program should simply call the function -@code{GNAT.Source_Info.Enclosing_Entity} to obtain the name of +@cite{GNAT.Source_Info.Enclosing_Entity} to obtain the name of the current subprogram, package, task, entry, or protected subprogram. -@node Exception_Information +@node Exception_Information,Exception_Message,Enclosing_Entity,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms id6}@anchor{208}@anchor{gnat_rm/intrinsic_subprograms exception-information}@anchor{209} @section Exception_Information -@cindex Exception_Information' -@noindent + + +@geindex Exception_Information' + This intrinsic subprogram is used in the implementation of the -library package @code{GNAT.Current_Exception}. The only useful +library package @cite{GNAT.Current_Exception}. The only useful use of the intrinsic import in this case is the one in this unit, so an application program should simply call the function -@code{GNAT.Current_Exception.Exception_Information} to obtain +@cite{GNAT.Current_Exception.Exception_Information} to obtain the exception information associated with the current exception. -@node Exception_Message +@node Exception_Message,Exception_Name,Exception_Information,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms exception-message}@anchor{20a}@anchor{gnat_rm/intrinsic_subprograms id7}@anchor{20b} @section Exception_Message -@cindex Exception_Message -@noindent + + +@geindex Exception_Message + This intrinsic subprogram is used in the implementation of the -library package @code{GNAT.Current_Exception}. The only useful +library package @cite{GNAT.Current_Exception}. The only useful use of the intrinsic import in this case is the one in this unit, so an application program should simply call the function -@code{GNAT.Current_Exception.Exception_Message} to obtain +@cite{GNAT.Current_Exception.Exception_Message} to obtain the message associated with the current exception. -@node Exception_Name +@node Exception_Name,File,Exception_Message,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms exception-name}@anchor{20c}@anchor{gnat_rm/intrinsic_subprograms id8}@anchor{20d} @section Exception_Name -@cindex Exception_Name -@noindent + + +@geindex Exception_Name + This intrinsic subprogram is used in the implementation of the -library package @code{GNAT.Current_Exception}. The only useful +library package @cite{GNAT.Current_Exception}. The only useful use of the intrinsic import in this case is the one in this unit, so an application program should simply call the function -@code{GNAT.Current_Exception.Exception_Name} to obtain +@cite{GNAT.Current_Exception.Exception_Name} to obtain the name of the current exception. -@node File +@node File,Line,Exception_Name,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms file}@anchor{20e}@anchor{gnat_rm/intrinsic_subprograms id9}@anchor{20f} @section File -@cindex File -@noindent + + +@geindex File + This intrinsic subprogram is used in the implementation of the -library package @code{GNAT.Source_Info}. The only useful use of the +library package @cite{GNAT.Source_Info}. The only useful use of the intrinsic import in this case is the one in this unit, so an application program should simply call the function -@code{GNAT.Source_Info.File} to obtain the name of the current +@cite{GNAT.Source_Info.File} to obtain the name of the current file. -@node Line +@node Line,Shifts and Rotates,File,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms id10}@anchor{210}@anchor{gnat_rm/intrinsic_subprograms line}@anchor{211} @section Line -@cindex Line -@noindent + + +@geindex Line + This intrinsic subprogram is used in the implementation of the -library package @code{GNAT.Source_Info}. The only useful use of the +library package @cite{GNAT.Source_Info}. The only useful use of the intrinsic import in this case is the one in this unit, so an application program should simply call the function -@code{GNAT.Source_Info.Line} to obtain the number of the current +@cite{GNAT.Source_Info.Line} to obtain the number of the current source line. -@node Shifts and Rotates +@node Shifts and Rotates,Source_Location,Line,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms id11}@anchor{212}@anchor{gnat_rm/intrinsic_subprograms shifts-and-rotates}@anchor{213} @section Shifts and Rotates -@cindex Shift_Left -@cindex Shift_Right -@cindex Shift_Right_Arithmetic -@cindex Rotate_Left -@cindex Rotate_Right -@noindent + + +@geindex Shift_Left + +@geindex Shift_Right + +@geindex Shift_Right_Arithmetic + +@geindex Rotate_Left + +@geindex Rotate_Right + In standard Ada, the shift and rotate functions are available only -for the predefined modular types in package @code{Interfaces}. However, in +for the predefined modular types in package @cite{Interfaces}. However, in GNAT it is possible to define these functions for any integer type (signed or modular), as in this example: -@smallexample @c ada - function Shift_Left - (Value : T; - Amount : Natural) return T; -@end smallexample +@example +function Shift_Left + (Value : T; + Amount : Natural) return T; +@end example -@noindent The function name must be one of Shift_Left, Shift_Right, Shift_Right_Arithmetic, Rotate_Left, or Rotate_Right. T must be an integer type. T'Size must be 8, 16, 32 or 64 bits; if T is modular, the modulus must be 2**8, 2**16, 2**32 or 2**64. -The result type must be the same as the type of @code{Value}. +The result type must be the same as the type of @cite{Value}. The shift amount must be Natural. The formal parameter names can be anything. @@ -14903,47 +17068,34 @@ A more convenient way of providing these shift operators is to use the Provide_Shift_Operators pragma, which provides the function declarations and corresponding pragma Import's for all five shift functions. -@node Source_Location +@node Source_Location,,Shifts and Rotates,Intrinsic Subprograms +@anchor{gnat_rm/intrinsic_subprograms source-location}@anchor{214}@anchor{gnat_rm/intrinsic_subprograms id12}@anchor{215} @section Source_Location -@cindex Source_Location -@noindent + + +@geindex Source_Location + This intrinsic subprogram is used in the implementation of the -library routine @code{GNAT.Source_Info}. The only useful use of the +library routine @cite{GNAT.Source_Info}. The only useful use of the intrinsic import in this case is the one in this unit, so an application program should simply call the function -@code{GNAT.Source_Info.Source_Location} to obtain the current +@cite{GNAT.Source_Info.Source_Location} to obtain the current source file location. -@node Representation Clauses and Pragmas +@node Representation Clauses and Pragmas,Standard Library Routines,Intrinsic Subprograms,Top +@anchor{gnat_rm/representation_clauses_and_pragmas representation-clauses-and-pragmas}@anchor{d}@anchor{gnat_rm/representation_clauses_and_pragmas doc}@anchor{216}@anchor{gnat_rm/representation_clauses_and_pragmas id1}@anchor{217} @chapter Representation Clauses and Pragmas -@cindex Representation Clauses -@menu -* Alignment Clauses:: -* Size Clauses:: -* Storage_Size Clauses:: -* Size of Variant Record Objects:: -* Biased Representation :: -* Value_Size and Object_Size Clauses:: -* Component_Size Clauses:: -* Bit_Order Clauses:: -* Effect of Bit_Order on Byte Ordering:: -* Pragma Pack for Arrays:: -* Pragma Pack for Records:: -* Record Representation Clauses:: -* Handling of Records with Holes:: -* Enumeration Clauses:: -* Address Clauses:: -* Use of Address Clauses for Memory-Mapped I/O:: -* Effect of Convention on Representation:: -* Conventions and Anonymous Access Types:: -* Determining the Representations chosen by GNAT:: -@end menu -@noindent -@cindex Representation Clause -@cindex Representation Pragma -@cindex Pragma, representation +@geindex Representation Clauses + +@geindex Representation Clause + +@geindex Representation Pragma + +@geindex Pragma +@geindex representation + This section describes the representation clauses accepted by GNAT, and their effect on the representation of corresponding data objects. @@ -14953,177 +17105,216 @@ However, these sections only require a minimal level of support for representation clauses. GNAT provides much more extensive capabilities, and this section describes the additional capabilities provided. -@node Alignment Clauses +@menu +* Alignment Clauses:: +* Size Clauses:: +* Storage_Size Clauses:: +* Size of Variant Record Objects:: +* Biased Representation:: +* Value_Size and Object_Size Clauses:: +* Component_Size Clauses:: +* Bit_Order Clauses:: +* Effect of Bit_Order on Byte Ordering:: +* Pragma Pack for Arrays:: +* Pragma Pack for Records:: +* Record Representation Clauses:: +* Handling of Records with Holes:: +* Enumeration Clauses:: +* Address Clauses:: +* Use of Address Clauses for Memory-Mapped I/O:: +* Effect of Convention on Representation:: +* Conventions and Anonymous Access Types:: +* Determining the Representations chosen by GNAT:: + +@end menu + +@node Alignment Clauses,Size Clauses,,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id2}@anchor{218}@anchor{gnat_rm/representation_clauses_and_pragmas alignment-clauses}@anchor{219} @section Alignment Clauses -@cindex Alignment Clause -@noindent + +@geindex Alignment Clause + GNAT requires that all alignment clauses specify a power of 2, and all default alignments are always a power of 2. The default alignment values are as follows: -@itemize @bullet -@item @emph{Primitive Types}. + +@itemize * + +@item +@emph{Primitive Types}. + For primitive types, the alignment is the minimum of the actual size of -objects of the type divided by @code{Storage_Unit}, +objects of the type divided by @cite{Storage_Unit}, and the maximum alignment supported by the target. (This maximum alignment is given by the GNAT-specific attribute -@code{Standard'Maximum_Alignment}; see @ref{Attribute Maximum_Alignment}.) -@cindex @code{Maximum_Alignment} attribute -For example, for type @code{Long_Float}, the object size is 8 bytes, and the +@cite{Standard'Maximum_Alignment}; see @ref{13c,,Attribute Maximum_Alignment}.) + +@geindex Maximum_Alignment attribute + +For example, for type @cite{Long_Float}, the object size is 8 bytes, and the default alignment will be 8 on any target that supports alignments this large, but on some targets, the maximum alignment may be smaller -than 8, in which case objects of type @code{Long_Float} will be maximally +than 8, in which case objects of type @cite{Long_Float} will be maximally aligned. -@item @emph{Arrays}. +@item +@emph{Arrays}. + For arrays, the alignment is equal to the alignment of the component type for the normal case where no packing or component size is given. If the array is packed, and the packing is effective (see separate section on packed arrays), then the alignment will be one for long packed arrays, or arrays whose length is not known at compile time. For short packed arrays, which are handled internally as modular types, the alignment -will be as described for primitive types, e.g.@: a packed array of length +will be as described for primitive types, e.g., a packed array of length 31 bits will have an object size of four bytes, and an alignment of 4. -@item @emph{Records}. +@item +@emph{Records}. + For the normal non-packed case, the alignment of a record is equal to the maximum alignment of any of its components. For tagged records, this -includes the implicit access type used for the tag. If a pragma @code{Pack} +includes the implicit access type used for the tag. If a pragma @cite{Pack} is used and all components are packable (see separate section on pragma -@code{Pack}), then the resulting alignment is 1, unless the layout of the +@cite{Pack}), then the resulting alignment is 1, unless the layout of the record makes it profitable to increase it. A special case is when: -@itemize @bullet -@item + + +@itemize * + +@item the size of the record is given explicitly, or a full record representation clause is given, and -@item + +@item the size of the record is 2, 4, or 8 bytes. @end itemize -@noindent + In this case, an alignment is chosen to match the size of the record. For example, if we have: -@smallexample @c ada - type Small is record - A, B : Character; - end record; - for Small'Size use 16; -@end smallexample +@example +type Small is record + A, B : Character; +end record; +for Small'Size use 16; +@end example -@noindent -then the default alignment of the record type @code{Small} is 2, not 1. This +then the default alignment of the record type @cite{Small} is 2, not 1. This leads to more efficient code when the record is treated as a unit, and also -allows the type to specified as @code{Atomic} on architectures requiring +allows the type to specified as @cite{Atomic} on architectures requiring strict alignment. - @end itemize -@noindent An alignment clause may specify a larger alignment than the default value up to some maximum value dependent on the target (obtainable by using the -attribute reference @code{Standard'Maximum_Alignment}). It may also specify +attribute reference @cite{Standard'Maximum_Alignment}). It may also specify a smaller alignment than the default value for enumeration, integer and fixed point types, as well as for record types, for example -@smallexample @c ada - type V is record - A : Integer; - end record; +@example +type V is record + A : Integer; +end record; - for V'alignment use 1; -@end smallexample +for V'alignment use 1; +@end example -@noindent -@cindex Alignment, default -The default alignment for the type @code{V} is 4, as a result of the +@geindex Alignment +@geindex default + +The default alignment for the type @cite{V} is 4, as a result of the Integer field in the record, but it is permissible, as shown, to override the default alignment of the record with a smaller value. -@cindex Alignment, subtypes +@geindex Alignment +@geindex subtypes + Note that according to the Ada standard, an alignment clause applies only to the first named subtype. If additional subtypes are declared, then the compiler is allowed to choose any alignment it likes, and there is no way to control this choice. Consider: -@smallexample @c ada - type R is range 1 .. 10_000; - for R'Alignment use 1; - subtype RS is R range 1 .. 1000; -@end smallexample +@example +type R is range 1 .. 10_000; +for R'Alignment use 1; +subtype RS is R range 1 .. 1000; +@end example -@noindent The alignment clause specifies an alignment of 1 for the first named subtype -@code{R} but this does not necessarily apply to @code{RS}. When writing +@cite{R} but this does not necessarily apply to @cite{RS}. When writing portable Ada code, you should avoid writing code that explicitly or implicitly relies on the alignment of such subtypes. For the GNAT compiler, if an explicit alignment clause is given, this value is also used for any subsequent subtypes. So for GNAT, in the -above example, you can count on the alignment of @code{RS} being 1. But this +above example, you can count on the alignment of @cite{RS} being 1. But this assumption is non-portable, and other compilers may choose different -alignments for the subtype @code{RS}. +alignments for the subtype @cite{RS}. -@node Size Clauses +@node Size Clauses,Storage_Size Clauses,Alignment Clauses,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id3}@anchor{21a}@anchor{gnat_rm/representation_clauses_and_pragmas size-clauses}@anchor{21b} @section Size Clauses -@cindex Size Clause -@noindent -The default size for a type @code{T} is obtainable through the -language-defined attribute @code{T'Size} and also through the -equivalent GNAT-defined attribute @code{T'Value_Size}. -For objects of type @code{T}, GNAT will generally increase the type size + +@geindex Size Clause + +The default size for a type @cite{T} is obtainable through the +language-defined attribute @cite{T'Size} and also through the +equivalent GNAT-defined attribute @cite{T'Value_Size}. +For objects of type @cite{T}, GNAT will generally increase the type size so that the object size (obtainable through the GNAT-defined attribute -@code{T'Object_Size}) -is a multiple of @code{T'Alignment * Storage_Unit}. -For example +@cite{T'Object_Size}) +is a multiple of @cite{T'Alignment * Storage_Unit}. -@smallexample @c ada - type Smallint is range 1 .. 6; +For example: - type Rec is record - Y1 : integer; - Y2 : boolean; - end record; -@end smallexample +@example +type Smallint is range 1 .. 6; -@noindent -In this example, @code{Smallint'Size} = @code{Smallint'Value_Size} = 3, +type Rec is record + Y1 : integer; + Y2 : boolean; +end record; +@end example + +In this example, @cite{Smallint'Size} = @cite{Smallint'Value_Size} = 3, as specified by the RM rules, but objects of this type will have a size of 8 -(@code{Smallint'Object_Size} = 8), +(@cite{Smallint'Object_Size} = 8), since objects by default occupy an integral number of storage units. On some targets, notably older versions of the Digital Alpha, the size of stand alone objects of this type may be 32, reflecting the inability of the hardware to do byte load/stores. -Similarly, the size of type @code{Rec} is 40 bits -(@code{Rec'Size} = @code{Rec'Value_Size} = 40), but +Similarly, the size of type @cite{Rec} is 40 bits +(@cite{Rec'Size} = @cite{Rec'Value_Size} = 40), but the alignment is 4, so objects of this type will have their size increased to 64 bits so that it is a multiple of the alignment (in bits). This decision is in accordance with the specific Implementation Advice in RM 13.3(43): @quotation -A @code{Size} clause should be supported for an object if the specified -@code{Size} is at least as large as its subtype's @code{Size}, and corresponds + +"A @cite{Size} clause should be supported for an object if the specified +@cite{Size} is at least as large as its subtype's @cite{Size}, and corresponds to a size in storage elements that is a multiple of the object's -@code{Alignment} (if the @code{Alignment} is nonzero). +@cite{Alignment} (if the @cite{Alignment} is nonzero)." @end quotation -@noindent An explicit size clause may be used to override the default size by increasing it. For example, if we have: -@smallexample @c ada - type My_Boolean is new Boolean; - for My_Boolean'Size use 32; -@end smallexample +@example +type My_Boolean is new Boolean; +for My_Boolean'Size use 32; +@end example -@noindent then values of this type will always be 32 bits long. In the case of discrete types, the size can be increased up to 64 bits, with the effect that the entire specified field is used to hold the value, sign- or @@ -15135,98 +17326,102 @@ Similarly the size of records and arrays may be increased, and the effect is to add padding bits after the value. This also causes a warning message to be generated. -The largest Size value permitted in GNAT is 2**31@minus{}1. Since this is a +The largest Size value permitted in GNAT is 2**31-1. Since this is a Size in bits, this corresponds to an object of size 256 megabytes (minus one). This limitation is true on all targets. The reason for this limitation is that it improves the quality of the code in many cases if it is known that a Size value can be accommodated in an object of type Integer. -@node Storage_Size Clauses +@node Storage_Size Clauses,Size of Variant Record Objects,Size Clauses,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas storage-size-clauses}@anchor{21c}@anchor{gnat_rm/representation_clauses_and_pragmas id4}@anchor{21d} @section Storage_Size Clauses -@cindex Storage_Size Clause -@noindent -For tasks, the @code{Storage_Size} clause specifies the amount of space + +@geindex Storage_Size Clause + +For tasks, the @cite{Storage_Size} clause specifies the amount of space to be allocated for the task stack. This cannot be extended, and if the -stack is exhausted, then @code{Storage_Error} will be raised (if stack -checking is enabled). Use a @code{Storage_Size} attribute definition clause, -or a @code{Storage_Size} pragma in the task definition to set the +stack is exhausted, then @cite{Storage_Error} will be raised (if stack +checking is enabled). Use a @cite{Storage_Size} attribute definition clause, +or a @cite{Storage_Size} pragma in the task definition to set the appropriate required size. A useful technique is to include in every task definition a pragma of the form: -@smallexample @c ada - pragma Storage_Size (Default_Stack_Size); -@end smallexample +@example +pragma Storage_Size (Default_Stack_Size); +@end example -@noindent -Then @code{Default_Stack_Size} can be defined in a global package, and +Then @cite{Default_Stack_Size} can be defined in a global package, and modified as required. Any tasks requiring stack sizes different from the default can have an appropriate alternative reference in the pragma. -You can also use the @option{-d} binder switch to modify the default stack +You can also use the @emph{-d} binder switch to modify the default stack size. -For access types, the @code{Storage_Size} clause specifies the maximum +For access types, the @cite{Storage_Size} clause specifies the maximum space available for allocation of objects of the type. If this space is -exceeded then @code{Storage_Error} will be raised by an allocation attempt. +exceeded then @cite{Storage_Error} will be raised by an allocation attempt. In the case where the access type is declared local to a subprogram, the -use of a @code{Storage_Size} clause triggers automatic use of a special -predefined storage pool (@code{System.Pool_Size}) that ensures that all +use of a @cite{Storage_Size} clause triggers automatic use of a special +predefined storage pool (@cite{System.Pool_Size}) that ensures that all space for the pool is automatically reclaimed on exit from the scope in which the type is declared. A special case recognized by the compiler is the specification of a -@code{Storage_Size} of zero for an access type. This means that no +@cite{Storage_Size} of zero for an access type. This means that no items can be allocated from the pool, and this is recognized at compile time, and all the overhead normally associated with maintaining a fixed size storage pool is eliminated. Consider the following example: -@smallexample @c ada - procedure p is - type R is array (Natural) of Character; - type P is access all R; - for P'Storage_Size use 0; - -- Above access type intended only for interfacing purposes +@example +procedure p is + type R is array (Natural) of Character; + type P is access all R; + for P'Storage_Size use 0; + -- Above access type intended only for interfacing purposes - y : P; + y : P; - procedure g (m : P); - pragma Import (C, g); + procedure g (m : P); + pragma Import (C, g); - -- @dots{} + -- ... - begin - -- @dots{} - y := new R; - end; -@end smallexample +begin + -- ... + y := new R; +end; +@end example -@noindent As indicated in this example, these dummy storage pools are often useful in connection with interfacing where no object will ever be allocated. If you compile the above example, you get the warning: -@smallexample - p.adb:16:09: warning: allocation from empty storage pool - p.adb:16:09: warning: Storage_Error will be raised at run time -@end smallexample +@example +p.adb:16:09: warning: allocation from empty storage pool +p.adb:16:09: warning: Storage_Error will be raised at run time +@end example -@noindent Of course in practice, there will not be any explicit allocators in the case of such an access declaration. -@node Size of Variant Record Objects +@node Size of Variant Record Objects,Biased Representation,Storage_Size Clauses,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id5}@anchor{21e}@anchor{gnat_rm/representation_clauses_and_pragmas size-of-variant-record-objects}@anchor{21f} @section Size of Variant Record Objects -@cindex Size, variant record objects -@cindex Variant record objects, size -@noindent + +@geindex Size +@geindex variant record objects + +@geindex Variant record objects +@geindex size + In the case of variant record objects, there is a question whether Size gives information about a particular variant, or the maximum size required for any variant. Consider the following program -@smallexample @c ada +@example with Text_IO; use Text_IO; procedure q is type R1 (A : Boolean := False) is record @@ -15243,21 +17438,19 @@ begin Put_Line (Integer'Image (V1'Size)); Put_Line (Integer'Image (V2'Size)); end q; -@end smallexample +@end example -@noindent Here we are dealing with a variant record, where the True variant requires 16 bits, and the False variant requires 8 bits. In the above example, both V1 and V2 contain the False variant, which is only 8 bits long. However, the result of running the program is: -@smallexample +@example 8 16 -@end smallexample +@end example -@noindent The reason for the difference here is that the discriminant value of V1 is fixed, and will always be False. It is not possible to assign a True variant value to V1, therefore 8 bits is sufficient. On the @@ -15267,12 +17460,12 @@ variant value to V2, therefore 16 bits must be allocated for V2 in the general case, even fewer bits may be needed at any particular point during the program execution. -As can be seen from the output of this program, the @code{'Size} +As can be seen from the output of this program, the @cite{'Size} attribute applied to such an object in GNAT gives the actual allocated size of the variable, which is the largest size of any of the variants. The Ada Reference Manual is not completely clear on what choice should be made here, but the GNAT behavior seems most consistent with the -language in the RM@. +language in the RM. In some cases, it may be desirable to obtain the size of the current variant, rather than the size of the largest variant. This can be @@ -15283,7 +17476,7 @@ is actually allocated for the actual). Consider the following modified version of the above program: -@smallexample @c ada +@example with Text_IO; use Text_IO; procedure q is type R1 (A : Boolean := False) is record @@ -15307,30 +17500,31 @@ begin Put_Line (Integer'Image (V2'Size)); Put_Line (Integer'IMage (Size (V2))); end q; -@end smallexample +@end example -@noindent The output from this program is -@smallexample +@example 16 8 16 16 -@end smallexample +@end example -@noindent -Here we see that while the @code{'Size} attribute always returns +Here we see that while the @cite{'Size} attribute always returns the maximum size, regardless of the current variant value, the -@code{Size} function does indeed return the size of the current +@cite{Size} function does indeed return the size of the current variant value. -@node Biased Representation +@node Biased Representation,Value_Size and Object_Size Clauses,Size of Variant Record Objects,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id6}@anchor{220}@anchor{gnat_rm/representation_clauses_and_pragmas biased-representation}@anchor{221} @section Biased Representation -@cindex Size for biased representation -@cindex Biased representation -@noindent + +@geindex Size for biased representation + +@geindex Biased representation + In the case of scalars with a range starting at other than zero, it is possible in some cases to specify a size smaller than the default minimum value, and in such cases, GNAT uses an unsigned biased representation, @@ -15339,264 +17533,338 @@ represent successive values of the type. For example, suppose we have the declaration: -@smallexample @c ada - type Small is range -7 .. -4; - for Small'Size use 2; -@end smallexample +@example +type Small is range -7 .. -4; +for Small'Size use 2; +@end example -@noindent -Although the default size of type @code{Small} is 4, the @code{Size} +Although the default size of type @cite{Small} is 4, the @cite{Size} clause is accepted by GNAT and results in the following representation scheme: -@smallexample - -7 is represented as 2#00# - -6 is represented as 2#01# - -5 is represented as 2#10# - -4 is represented as 2#11# -@end smallexample +@example +-7 is represented as 2#00# +-6 is represented as 2#01# +-5 is represented as 2#10# +-4 is represented as 2#11# +@end example -@noindent -Biased representation is only used if the specified @code{Size} clause +Biased representation is only used if the specified @cite{Size} clause cannot be accepted in any other manner. These reduced sizes that force biased representation can be used for all discrete types except for enumeration types for which a representation clause is given. -@node Value_Size and Object_Size Clauses +@node Value_Size and Object_Size Clauses,Component_Size Clauses,Biased Representation,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id7}@anchor{222}@anchor{gnat_rm/representation_clauses_and_pragmas value-size-and-object-size-clauses}@anchor{223} @section Value_Size and Object_Size Clauses -@findex Value_Size -@findex Object_Size -@cindex Size, of objects -@noindent -In Ada 95 and Ada 2005, @code{T'Size} for a type @code{T} is the minimum -number of bits required to hold values of type @code{T}. + +@geindex Value_Size + +@geindex Object_Size + +@geindex Size +@geindex of objects + +In Ada 95 and Ada 2005, @cite{T'Size} for a type @cite{T} is the minimum +number of bits required to hold values of type @cite{T}. Although this interpretation was allowed in Ada 83, it was not required, and this requirement in practice can cause some significant difficulties. -For example, in most Ada 83 compilers, @code{Natural'Size} was 32. +For example, in most Ada 83 compilers, @cite{Natural'Size} was 32. However, in Ada 95 and Ada 2005, -@code{Natural'Size} is +@cite{Natural'Size} is typically 31. This means that code may change in behavior when moving from Ada 83 to Ada 95 or Ada 2005. For example, consider: -@smallexample @c ada - type Rec is record; - A : Natural; - B : Natural; - end record; +@example +type Rec is record; + A : Natural; + B : Natural; +end record; - for Rec use record - at 0 range 0 .. Natural'Size - 1; - at 0 range Natural'Size .. 2 * Natural'Size - 1; - end record; -@end smallexample +for Rec use record + at 0 range 0 .. Natural'Size - 1; + at 0 range Natural'Size .. 2 * Natural'Size - 1; +end record; +@end example -@noindent -In the above code, since the typical size of @code{Natural} objects -is 32 bits and @code{Natural'Size} is 31, the above code can cause +In the above code, since the typical size of @cite{Natural} objects +is 32 bits and @cite{Natural'Size} is 31, the above code can cause unexpected inefficient packing in Ada 95 and Ada 2005, and in general there are cases where the fact that the object size can exceed the size of the type causes surprises. To help get around this problem GNAT provides two implementation -defined attributes, @code{Value_Size} and @code{Object_Size}. When +defined attributes, @cite{Value_Size} and @cite{Object_Size}. When applied to a type, these attributes yield the size of the type (corresponding to the RM defined size attribute), and the size of objects of the type respectively. -The @code{Object_Size} is used for determining the default size of +The @cite{Object_Size} is used for determining the default size of objects and components. This size value can be referred to using the -@code{Object_Size} attribute. The phrase ``is used'' here means that it is +@cite{Object_Size} attribute. The phrase 'is used' here means that it is the basis of the determination of the size. The backend is free to -pad this up if necessary for efficiency, e.g.@: an 8-bit stand-alone +pad this up if necessary for efficiency, e.g., an 8-bit stand-alone character might be stored in 32 bits on a machine with no efficient byte access instructions such as the Alpha. -The default rules for the value of @code{Object_Size} for +The default rules for the value of @cite{Object_Size} for discrete types are as follows: -@itemize @bullet -@item -The @code{Object_Size} for base subtypes reflect the natural hardware -size in bits (run the compiler with @option{-gnatS} to find those values + +@itemize * + +@item +The @cite{Object_Size} for base subtypes reflect the natural hardware +size in bits (run the compiler with @emph{-gnatS} to find those values for numeric types). Enumeration types and fixed-point base subtypes have 8, 16, 32 or 64 bits for this size, depending on the range of values to be stored. -@item -The @code{Object_Size} of a subtype is the same as the -@code{Object_Size} of +@item +The @cite{Object_Size} of a subtype is the same as the +@cite{Object_Size} of the type from which it is obtained. -@item -The @code{Object_Size} of a derived base type is copied from the parent -base type, and the @code{Object_Size} of a derived first subtype is copied +@item +The @cite{Object_Size} of a derived base type is copied from the parent +base type, and the @cite{Object_Size} of a derived first subtype is copied from the parent first subtype. @end itemize -@noindent -The @code{Value_Size} attribute +The @cite{Value_Size} attribute is the (minimum) number of bits required to store a value of the type. This value is used to determine how tightly to pack records or arrays with components of this type, and also affects the semantics of unchecked conversion (unchecked conversions where -the @code{Value_Size} values differ generate a warning, and are potentially +the @cite{Value_Size} values differ generate a warning, and are potentially target dependent). -The default rules for the value of @code{Value_Size} are as follows: +The default rules for the value of @cite{Value_Size} are as follows: -@itemize @bullet -@item -The @code{Value_Size} for a base subtype is the minimum number of bits + +@itemize * + +@item +The @cite{Value_Size} for a base subtype is the minimum number of bits required to store all values of the type (including the sign bit only if negative values are possible). -@item +@item If a subtype statically matches the first subtype of a given type, then it has -by default the same @code{Value_Size} as the first subtype. This is a -consequence of RM 13.1(14) (``if two subtypes statically match, -then their subtype-specific aspects are the same''.) +by default the same @cite{Value_Size} as the first subtype. This is a +consequence of RM 13.1(14): "if two subtypes statically match, +then their subtype-specific aspects are the same".) -@item -All other subtypes have a @code{Value_Size} corresponding to the minimum +@item +All other subtypes have a @cite{Value_Size} corresponding to the minimum number of bits required to store all values of the subtype. For dynamic bounds, it is assumed that the value can range down or up to the corresponding bound of the ancestor @end itemize -@noindent -The RM defined attribute @code{Size} corresponds to the -@code{Value_Size} attribute. +The RM defined attribute @cite{Size} corresponds to the +@cite{Value_Size} attribute. -The @code{Size} attribute may be defined for a first-named subtype. This sets -the @code{Value_Size} of +The @cite{Size} attribute may be defined for a first-named subtype. This sets +the @cite{Value_Size} of the first-named subtype to the given value, and the -@code{Object_Size} of this first-named subtype to the given value padded up +@cite{Object_Size} of this first-named subtype to the given value padded up to an appropriate boundary. It is a consequence of the default rules -above that this @code{Object_Size} will apply to all further subtypes. On the -other hand, @code{Value_Size} is affected only for the first subtype, any +above that this @cite{Object_Size} will apply to all further subtypes. On the +other hand, @cite{Value_Size} is affected only for the first subtype, any dynamic subtypes obtained from it directly, and any statically matching -subtypes. The @code{Value_Size} of any other static subtypes is not affected. +subtypes. The @cite{Value_Size} of any other static subtypes is not affected. -@code{Value_Size} and -@code{Object_Size} may be explicitly set for any subtype using +@cite{Value_Size} and +@cite{Object_Size} may be explicitly set for any subtype using an attribute definition clause. Note that the use of these attributes can cause the RM 13.1(14) rule to be violated. If two access types -reference aliased objects whose subtypes have differing @code{Object_Size} +reference aliased objects whose subtypes have differing @cite{Object_Size} values as a result of explicit attribute definition clauses, then it is illegal to convert from one access subtype to the other. For a more complete description of this additional legality rule, see the -description of the @code{Object_Size} attribute. +description of the @cite{Object_Size} attribute. At the implementation level, Esize stores the Object_Size and the -RM_Size field stores the @code{Value_Size} (and hence the value of the -@code{Size} attribute, -which, as noted above, is equivalent to @code{Value_Size}). +RM_Size field stores the @cite{Value_Size} (and hence the value of the +@cite{Size} attribute, +which, as noted above, is equivalent to @cite{Value_Size}). To get a feel for the difference, consider the following examples (note -that in each case the base is @code{Short_Short_Integer} with a size of 8): +that in each case the base is @cite{Short_Short_Integer} with a size of 8): + + +@multitable {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxx} +@headitem -@smallexample - Object_Size Value_Size +Type or subtype declaration -type x1 is range 0 .. 5; 8 3 +@tab -type x2 is range 0 .. 5; -for x2'size use 12; 16 12 +Object_Size -subtype x3 is x2 range 0 .. 3; 16 2 +@tab -subtype x4 is x2'base range 0 .. 10; 8 4 +Value_Size -subtype x5 is x2 range 0 .. dynamic; 16 3* +@item + +@code{type x1 is range 0 .. 5;} + +@tab + +8 -subtype x6 is x2'base range 0 .. dynamic; 8 3* +@tab -@end smallexample +3 -@noindent -Note: the entries marked ``3*'' are not actually specified by the Ada +@item + +@code{type x2 is range 0 .. 5;} +@code{for x2'size use 12;} + +@tab + +16 + +@tab + +12 + +@item + +@code{subtype x3 is x2 range 0 .. 3;} + +@tab + +16 + +@tab + +2 + +@item + +@code{subtype x4 is x2'base range 0 .. 10;} + +@tab + +8 + +@tab + +4 + +@item + +@code{subtype x5 is x2 range 0 .. dynamic;} + +@tab + +16 + +@tab + +3* + +@item + +@code{subtype x6 is x2'base range 0 .. dynamic;} + +@tab + +8 + +@tab + +3* + +@end multitable + + +Note: the entries marked '3*' are not actually specified by the Ada Reference Manual, but it seems in the spirit of the RM rules to allocate -the minimum number of bits (here 3, given the range for @code{x2}) +the minimum number of bits (here 3, given the range for @cite{x2}) known to be large enough to hold the given range of values. So far, so good, but GNAT has to obey the RM rules, so the question is -under what conditions must the RM @code{Size} be used. +under what conditions must the RM @cite{Size} be used. The following is a list -of the occasions on which the RM @code{Size} must be used: +of the occasions on which the RM @cite{Size} must be used: -@itemize @bullet -@item + +@itemize * + +@item Component size for packed arrays or records -@item -Value of the attribute @code{Size} for a type +@item +Value of the attribute @cite{Size} for a type -@item +@item Warning about sizes not matching for unchecked conversion @end itemize -@noindent -For record types, the @code{Object_Size} is always a multiple of the +For record types, the @cite{Object_Size} is always a multiple of the alignment of the type (this is true for all types). In some cases the -@code{Value_Size} can be smaller. Consider: +@cite{Value_Size} can be smaller. Consider: -@smallexample - type R is record - X : Integer; - Y : Character; - end record; -@end smallexample +@example +type R is record + X : Integer; + Y : Character; +end record; +@end example -@noindent On a typical 32-bit architecture, the X component will be four bytes, and require four-byte alignment, and the Y component will be one byte. In this -case @code{R'Value_Size} will be 40 (bits) since this is the minimum size +case @cite{R'Value_Size} will be 40 (bits) since this is the minimum size required to store a value of this type, and for example, it is permissible to have a component of type R in an outer array whose component size is -specified to be 48 bits. However, @code{R'Object_Size} will be 64 (bits), +specified to be 48 bits. However, @cite{R'Object_Size} will be 64 (bits), since it must be rounded up so that this value is a multiple of the alignment (4 bytes = 32 bits). -@noindent -For all other types, the @code{Object_Size} -and Value_Size are the same (and equivalent to the RM attribute @code{Size}). -Only @code{Size} may be specified for such types. +For all other types, the @cite{Object_Size} +and Value_Size are the same (and equivalent to the RM attribute @cite{Size}). +Only @cite{Size} may be specified for such types. -Note that @code{Value_Size} can be used to force biased representation +Note that @cite{Value_Size} can be used to force biased representation for a particular subtype. Consider this example: -@smallexample - type R is (A, B, C, D, E, F); - subtype RAB is R range A .. B; - subtype REF is R range E .. F; -@end smallexample +@example +type R is (A, B, C, D, E, F); +subtype RAB is R range A .. B; +subtype REF is R range E .. F; +@end example -@noindent -By default, @code{RAB} +By default, @cite{RAB} has a size of 1 (sufficient to accommodate the representation -of @code{A} and @code{B}, 0 and 1), and @code{REF} +of @cite{A} and @cite{B}, 0 and 1), and @cite{REF} has a size of 3 (sufficient to accommodate the representation -of @code{E} and @code{F}, 4 and 5). But if we add the -following @code{Value_Size} attribute definition clause: +of @cite{E} and @cite{F}, 4 and 5). But if we add the +following @cite{Value_Size} attribute definition clause: -@smallexample - for REF'Value_Size use 1; -@end smallexample +@example +for REF'Value_Size use 1; +@end example -@noindent -then biased representation is forced for @code{REF}, -and 0 will represent @code{E} and 1 will represent @code{F}. -A warning is issued when a @code{Value_Size} attribute +then biased representation is forced for @cite{REF}, +and 0 will represent @cite{E} and 1 will represent @cite{F}. +A warning is issued when a @cite{Value_Size} attribute definition clause forces biased representation. This -warning can be turned off using @code{-gnatw.B}. +warning can be turned off using @cite{-gnatw.B}. -@node Component_Size Clauses +@node Component_Size Clauses,Bit_Order Clauses,Value_Size and Object_Size Clauses,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id8}@anchor{224}@anchor{gnat_rm/representation_clauses_and_pragmas component-size-clauses}@anchor{225} @section Component_Size Clauses -@cindex Component_Size Clause -@noindent + +@geindex Component_Size Clause + Normally, the value specified in a component size clause must be consistent with the subtype of the array component with regard to size and alignment. In other words, the value specified must be at least equal to the size @@ -15608,19 +17876,18 @@ component size values in the range 1 through 63. The value specified must not be smaller than the Size of the subtype. GNAT will accurately honor all packing requests in this range. For example, if we have: -@smallexample @c ada +@example type r is array (1 .. 8) of Natural; for r'Component_Size use 31; -@end smallexample +@end example -@noindent then the resulting array has a length of 31 bytes (248 bits = 8 * 31). Of course access to the components of such an array is considerably less efficient than if the natural component size of 32 is used. A second case is when the subtype of the component is a record type padded because of its default alignment. For example, if we have: -@smallexample @c ada +@example type r is record i : Integer; j : Integer; @@ -15629,9 +17896,8 @@ end record; type a is array (1 .. 8) of r; for a'Component_Size use 72; -@end smallexample +@end example -@noindent then the resulting array has a length of 72 bytes, instead of 96 bytes if the alignment of the record (4) was obeyed. @@ -15639,14 +17905,19 @@ Note that there is no point in giving both a component size clause and a pragma Pack for the same array type. if such duplicate clauses are given, the pragma Pack will be ignored. -@node Bit_Order Clauses +@node Bit_Order Clauses,Effect of Bit_Order on Byte Ordering,Component_Size Clauses,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas bit-order-clauses}@anchor{226}@anchor{gnat_rm/representation_clauses_and_pragmas id9}@anchor{227} @section Bit_Order Clauses -@cindex Bit_Order Clause -@cindex bit ordering -@cindex ordering, of bits -@noindent -For record subtypes, GNAT permits the specification of the @code{Bit_Order} + +@geindex Bit_Order Clause + +@geindex bit ordering + +@geindex ordering +@geindex of bits + +For record subtypes, GNAT permits the specification of the @cite{Bit_Order} attribute. The specification may either correspond to the default bit order for the target, in which case the specification has no effect and places no additional restrictions, or it may be for the non-standard @@ -15657,138 +17928,142 @@ to renumber bits within each byte, but the ordering of bytes is not affected. There are certain restrictions placed on component clauses as follows: -@itemize @bullet -@item Components fitting within a single storage unit. -@noindent +@itemize * + +@item +Components fitting within a single storage unit. + These are unrestricted, and the effect is merely to renumber bits. For -example if we are on a little-endian machine with @code{Low_Order_First} +example if we are on a little-endian machine with @cite{Low_Order_First} being the default, then the following two declarations have exactly the same effect: -@smallexample @c ada - type R1 is record - A : Boolean; - B : Integer range 1 .. 120; - end record; +@example +type R1 is record + A : Boolean; + B : Integer range 1 .. 120; +end record; - for R1 use record - A at 0 range 0 .. 0; - B at 0 range 1 .. 7; - end record; +for R1 use record + A at 0 range 0 .. 0; + B at 0 range 1 .. 7; +end record; - type R2 is record - A : Boolean; - B : Integer range 1 .. 120; - end record; +type R2 is record + A : Boolean; + B : Integer range 1 .. 120; +end record; - for R2'Bit_Order use High_Order_First; +for R2'Bit_Order use High_Order_First; - for R2 use record - A at 0 range 7 .. 7; - B at 0 range 0 .. 6; - end record; -@end smallexample +for R2 use record + A at 0 range 7 .. 7; + B at 0 range 0 .. 6; +end record; +@end example -@noindent The useful application here is to write the second declaration with the -@code{Bit_Order} attribute definition clause, and know that it will be treated +@cite{Bit_Order} attribute definition clause, and know that it will be treated the same, regardless of whether the target is little-endian or big-endian. -@item Components occupying an integral number of bytes. -@noindent +@item +Components occupying an integral number of bytes. + These are components that exactly fit in two or more bytes. Such component declarations are allowed, but have no effect, since it is important to realize -that the @code{Bit_Order} specification does not affect the ordering of bytes. +that the @cite{Bit_Order} specification does not affect the ordering of bytes. In particular, the following attempt at getting an endian-independent integer does not work: -@smallexample @c ada - type R2 is record - A : Integer; - end record; +@example +type R2 is record + A : Integer; +end record; - for R2'Bit_Order use High_Order_First; +for R2'Bit_Order use High_Order_First; - for R2 use record - A at 0 range 0 .. 31; - end record; -@end smallexample +for R2 use record + A at 0 range 0 .. 31; +end record; +@end example -@noindent This declaration will result in a little-endian integer on a little-endian machine, and a big-endian integer on a big-endian machine. If byte flipping is required for interoperability between big- and little-endian machines, this must be explicitly programmed. This capability -is not provided by @code{Bit_Order}. +is not provided by @cite{Bit_Order}. + +@item +Components that are positioned across byte boundaries -@item Components that are positioned across byte boundaries -@noindent but do not occupy an integral number of bytes. Given that bytes are not reordered, such fields would occupy a non-contiguous sequence of bits in memory, requiring non-trivial code to reassemble. They are for this reason not permitted, and any component clause specifying such a layout -will be flagged as illegal by GNAT@. - +will be flagged as illegal by GNAT. @end itemize -@noindent Since the misconception that Bit_Order automatically deals with all endian-related incompatibilities is a common one, the specification of a component field that is an integral number of bytes will always -generate a warning. This warning may be suppressed using @code{pragma -Warnings (Off)} if desired. The following section contains additional +generate a warning. This warning may be suppressed using @cite{pragma Warnings (Off)} +if desired. The following section contains additional details regarding the issue of byte ordering. -@node Effect of Bit_Order on Byte Ordering +@node Effect of Bit_Order on Byte Ordering,Pragma Pack for Arrays,Bit_Order Clauses,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id10}@anchor{228}@anchor{gnat_rm/representation_clauses_and_pragmas effect-of-bit-order-on-byte-ordering}@anchor{229} @section Effect of Bit_Order on Byte Ordering -@cindex byte ordering -@cindex ordering, of bytes -@noindent -In this section we will review the effect of the @code{Bit_Order} attribute + +@geindex byte ordering + +@geindex ordering +@geindex of bytes + +In this section we will review the effect of the @cite{Bit_Order} attribute definition clause on byte ordering. Briefly, it has no effect at all, but a detailed example will be helpful. Before giving this example, let us review the precise -definition of the effect of defining @code{Bit_Order}. The effect of a +definition of the effect of defining @cite{Bit_Order}. The effect of a non-standard bit order is described in section 15.5.3 of the Ada Reference Manual: @quotation -2 A bit ordering is a method of interpreting the meaning of -the storage place attributes. + +"2 A bit ordering is a method of interpreting the meaning of +the storage place attributes." @end quotation -@noindent To understand the precise definition of storage place attributes in this context, we visit section 13.5.1 of the manual: @quotation -13 A record_representation_clause (without the mod_clause) + +"13 A record_representation_clause (without the mod_clause) specifies the layout. The storage place attributes (see 13.5.2) are taken from the values of the position, first_bit, and last_bit expressions after normalizing those values so that first_bit is -less than Storage_Unit. +less than Storage_Unit." @end quotation -@noindent The critical point here is that storage places are taken from -the values after normalization, not before. So the @code{Bit_Order} +the values after normalization, not before. So the @cite{Bit_Order} interpretation applies to normalized values. The interpretation is described in the later part of the 15.5.3 paragraph: @quotation -2 A bit ordering is a method of interpreting the meaning of + +"2 A bit ordering is a method of interpreting the meaning of the storage place attributes. High_Order_First (known in the -vernacular as ``big endian'') means that the first bit of a +vernacular as 'big endian') means that the first bit of a storage element (bit 0) is the most significant bit (interpreting the sequence of bits that represent a component as an unsigned integer value). Low_Order_First (known in the vernacular as -``little endian'') means the opposite: the first bit is the -least significant. +'little endian') means the opposite: the first bit is the +least significant." @end quotation -@noindent Note that the numbering is with respect to the bits of a storage unit. In other words, the specification affects only the numbering of bits within a single storage unit. @@ -15800,156 +18075,151 @@ byte presented, which is the first (low addressed byte) of the two byte record is called Master, and the second byte is called Slave. The left most (most significant bit is called Control for each byte, and -the remaining 7 bits are called V1, V2, @dots{} V7, where V7 is the rightmost +the remaining 7 bits are called V1, V2, ... V7, where V7 is the rightmost (least significant) bit. On a big-endian machine, we can write the following representation clause -@smallexample @c ada - type Data is record - Master_Control : Bit; - Master_V1 : Bit; - Master_V2 : Bit; - Master_V3 : Bit; - Master_V4 : Bit; - Master_V5 : Bit; - Master_V6 : Bit; - Master_V7 : Bit; - Slave_Control : Bit; - Slave_V1 : Bit; - Slave_V2 : Bit; - Slave_V3 : Bit; - Slave_V4 : Bit; - Slave_V5 : Bit; - Slave_V6 : Bit; - Slave_V7 : Bit; - end record; +@example +type Data is record + Master_Control : Bit; + Master_V1 : Bit; + Master_V2 : Bit; + Master_V3 : Bit; + Master_V4 : Bit; + Master_V5 : Bit; + Master_V6 : Bit; + Master_V7 : Bit; + Slave_Control : Bit; + Slave_V1 : Bit; + Slave_V2 : Bit; + Slave_V3 : Bit; + Slave_V4 : Bit; + Slave_V5 : Bit; + Slave_V6 : Bit; + Slave_V7 : Bit; +end record; - for Data use record - Master_Control at 0 range 0 .. 0; - Master_V1 at 0 range 1 .. 1; - Master_V2 at 0 range 2 .. 2; - Master_V3 at 0 range 3 .. 3; - Master_V4 at 0 range 4 .. 4; - Master_V5 at 0 range 5 .. 5; - Master_V6 at 0 range 6 .. 6; - Master_V7 at 0 range 7 .. 7; - Slave_Control at 1 range 0 .. 0; - Slave_V1 at 1 range 1 .. 1; - Slave_V2 at 1 range 2 .. 2; - Slave_V3 at 1 range 3 .. 3; - Slave_V4 at 1 range 4 .. 4; - Slave_V5 at 1 range 5 .. 5; - Slave_V6 at 1 range 6 .. 6; - Slave_V7 at 1 range 7 .. 7; - end record; -@end smallexample +for Data use record + Master_Control at 0 range 0 .. 0; + Master_V1 at 0 range 1 .. 1; + Master_V2 at 0 range 2 .. 2; + Master_V3 at 0 range 3 .. 3; + Master_V4 at 0 range 4 .. 4; + Master_V5 at 0 range 5 .. 5; + Master_V6 at 0 range 6 .. 6; + Master_V7 at 0 range 7 .. 7; + Slave_Control at 1 range 0 .. 0; + Slave_V1 at 1 range 1 .. 1; + Slave_V2 at 1 range 2 .. 2; + Slave_V3 at 1 range 3 .. 3; + Slave_V4 at 1 range 4 .. 4; + Slave_V5 at 1 range 5 .. 5; + Slave_V6 at 1 range 6 .. 6; + Slave_V7 at 1 range 7 .. 7; +end record; +@end example -@noindent Now if we move this to a little endian machine, then the bit ordering within the byte is backwards, so we have to rewrite the record rep clause as: -@smallexample @c ada - for Data use record - Master_Control at 0 range 7 .. 7; - Master_V1 at 0 range 6 .. 6; - Master_V2 at 0 range 5 .. 5; - Master_V3 at 0 range 4 .. 4; - Master_V4 at 0 range 3 .. 3; - Master_V5 at 0 range 2 .. 2; - Master_V6 at 0 range 1 .. 1; - Master_V7 at 0 range 0 .. 0; - Slave_Control at 1 range 7 .. 7; - Slave_V1 at 1 range 6 .. 6; - Slave_V2 at 1 range 5 .. 5; - Slave_V3 at 1 range 4 .. 4; - Slave_V4 at 1 range 3 .. 3; - Slave_V5 at 1 range 2 .. 2; - Slave_V6 at 1 range 1 .. 1; - Slave_V7 at 1 range 0 .. 0; - end record; -@end smallexample +@example +for Data use record + Master_Control at 0 range 7 .. 7; + Master_V1 at 0 range 6 .. 6; + Master_V2 at 0 range 5 .. 5; + Master_V3 at 0 range 4 .. 4; + Master_V4 at 0 range 3 .. 3; + Master_V5 at 0 range 2 .. 2; + Master_V6 at 0 range 1 .. 1; + Master_V7 at 0 range 0 .. 0; + Slave_Control at 1 range 7 .. 7; + Slave_V1 at 1 range 6 .. 6; + Slave_V2 at 1 range 5 .. 5; + Slave_V3 at 1 range 4 .. 4; + Slave_V4 at 1 range 3 .. 3; + Slave_V5 at 1 range 2 .. 2; + Slave_V6 at 1 range 1 .. 1; + Slave_V7 at 1 range 0 .. 0; +end record; +@end example -@noindent It is a nuisance to have to rewrite the clause, especially if the code has to be maintained on both machines. However, this is a case that we can handle with the -@code{Bit_Order} attribute if it is implemented. +@cite{Bit_Order} attribute if it is implemented. Note that the implementation is not required on byte addressed machines, but it is indeed implemented in GNAT. This means that we can simply use the first record clause, together with the declaration -@smallexample @c ada - for Data'Bit_Order use High_Order_First; -@end smallexample +@example +for Data'Bit_Order use High_Order_First; +@end example -@noindent and the effect is what is desired, namely the layout is exactly the same, independent of whether the code is compiled on a big-endian or little-endian machine. The important point to understand is that byte ordering is not affected. -A @code{Bit_Order} attribute definition never affects which byte a field +A @cite{Bit_Order} attribute definition never affects which byte a field ends up in, only where it ends up in that byte. To make this clear, let us rewrite the record rep clause of the previous example as: -@smallexample @c ada - for Data'Bit_Order use High_Order_First; - for Data use record - Master_Control at 0 range 0 .. 0; - Master_V1 at 0 range 1 .. 1; - Master_V2 at 0 range 2 .. 2; - Master_V3 at 0 range 3 .. 3; - Master_V4 at 0 range 4 .. 4; - Master_V5 at 0 range 5 .. 5; - Master_V6 at 0 range 6 .. 6; - Master_V7 at 0 range 7 .. 7; - Slave_Control at 0 range 8 .. 8; - Slave_V1 at 0 range 9 .. 9; - Slave_V2 at 0 range 10 .. 10; - Slave_V3 at 0 range 11 .. 11; - Slave_V4 at 0 range 12 .. 12; - Slave_V5 at 0 range 13 .. 13; - Slave_V6 at 0 range 14 .. 14; - Slave_V7 at 0 range 15 .. 15; - end record; -@end smallexample +@example +for Data'Bit_Order use High_Order_First; +for Data use record + Master_Control at 0 range 0 .. 0; + Master_V1 at 0 range 1 .. 1; + Master_V2 at 0 range 2 .. 2; + Master_V3 at 0 range 3 .. 3; + Master_V4 at 0 range 4 .. 4; + Master_V5 at 0 range 5 .. 5; + Master_V6 at 0 range 6 .. 6; + Master_V7 at 0 range 7 .. 7; + Slave_Control at 0 range 8 .. 8; + Slave_V1 at 0 range 9 .. 9; + Slave_V2 at 0 range 10 .. 10; + Slave_V3 at 0 range 11 .. 11; + Slave_V4 at 0 range 12 .. 12; + Slave_V5 at 0 range 13 .. 13; + Slave_V6 at 0 range 14 .. 14; + Slave_V7 at 0 range 15 .. 15; +end record; +@end example -@noindent This is exactly equivalent to saying (a repeat of the first example): -@smallexample @c ada - for Data'Bit_Order use High_Order_First; - for Data use record - Master_Control at 0 range 0 .. 0; - Master_V1 at 0 range 1 .. 1; - Master_V2 at 0 range 2 .. 2; - Master_V3 at 0 range 3 .. 3; - Master_V4 at 0 range 4 .. 4; - Master_V5 at 0 range 5 .. 5; - Master_V6 at 0 range 6 .. 6; - Master_V7 at 0 range 7 .. 7; - Slave_Control at 1 range 0 .. 0; - Slave_V1 at 1 range 1 .. 1; - Slave_V2 at 1 range 2 .. 2; - Slave_V3 at 1 range 3 .. 3; - Slave_V4 at 1 range 4 .. 4; - Slave_V5 at 1 range 5 .. 5; - Slave_V6 at 1 range 6 .. 6; - Slave_V7 at 1 range 7 .. 7; - end record; -@end smallexample +@example +for Data'Bit_Order use High_Order_First; +for Data use record + Master_Control at 0 range 0 .. 0; + Master_V1 at 0 range 1 .. 1; + Master_V2 at 0 range 2 .. 2; + Master_V3 at 0 range 3 .. 3; + Master_V4 at 0 range 4 .. 4; + Master_V5 at 0 range 5 .. 5; + Master_V6 at 0 range 6 .. 6; + Master_V7 at 0 range 7 .. 7; + Slave_Control at 1 range 0 .. 0; + Slave_V1 at 1 range 1 .. 1; + Slave_V2 at 1 range 2 .. 2; + Slave_V3 at 1 range 3 .. 3; + Slave_V4 at 1 range 4 .. 4; + Slave_V5 at 1 range 5 .. 5; + Slave_V6 at 1 range 6 .. 6; + Slave_V7 at 1 range 7 .. 7; +end record; +@end example -@noindent -Why are they equivalent? Well take a specific field, the @code{Slave_V2} +Why are they equivalent? Well take a specific field, the @cite{Slave_V2} field. The storage place attributes are obtained by normalizing the -values given so that the @code{First_Bit} value is less than 8. After +values given so that the @cite{First_Bit} value is less than 8. After normalizing the values (0,10,10) we get (1,2,2) which is exactly what we specified in the other case. -Now one might expect that the @code{Bit_Order} attribute might affect +Now one might expect that the @cite{Bit_Order} attribute might affect bit numbering within the entire record component (two bytes in this case, thus affecting which byte fields end up in), but that is not the way this feature is defined, it only affects numbering of bits, @@ -15957,7 +18227,7 @@ not which byte they end up in. Consequently it never makes sense to specify a starting bit number greater than 7 (for a byte addressable field) if an attribute -definition for @code{Bit_Order} has been given, and indeed it +definition for @cite{Bit_Order} has been given, and indeed it may be actively confusing to specify such a value, so the compiler generates a warning for such usage. @@ -15965,86 +18235,90 @@ If you do need to control byte ordering then appropriate conditional values must be used. If in our example, the slave byte came first on some machines we might write: -@smallexample @c ada - Master_Byte_First constant Boolean := @dots{}; - - Master_Byte : constant Natural := - 1 - Boolean'Pos (Master_Byte_First); - Slave_Byte : constant Natural := - Boolean'Pos (Master_Byte_First); - - for Data'Bit_Order use High_Order_First; - for Data use record - Master_Control at Master_Byte range 0 .. 0; - Master_V1 at Master_Byte range 1 .. 1; - Master_V2 at Master_Byte range 2 .. 2; - Master_V3 at Master_Byte range 3 .. 3; - Master_V4 at Master_Byte range 4 .. 4; - Master_V5 at Master_Byte range 5 .. 5; - Master_V6 at Master_Byte range 6 .. 6; - Master_V7 at Master_Byte range 7 .. 7; - Slave_Control at Slave_Byte range 0 .. 0; - Slave_V1 at Slave_Byte range 1 .. 1; - Slave_V2 at Slave_Byte range 2 .. 2; - Slave_V3 at Slave_Byte range 3 .. 3; - Slave_V4 at Slave_Byte range 4 .. 4; - Slave_V5 at Slave_Byte range 5 .. 5; - Slave_V6 at Slave_Byte range 6 .. 6; - Slave_V7 at Slave_Byte range 7 .. 7; - end record; -@end smallexample +@example +Master_Byte_First constant Boolean := ...; + +Master_Byte : constant Natural := + 1 - Boolean'Pos (Master_Byte_First); +Slave_Byte : constant Natural := + Boolean'Pos (Master_Byte_First); + +for Data'Bit_Order use High_Order_First; +for Data use record + Master_Control at Master_Byte range 0 .. 0; + Master_V1 at Master_Byte range 1 .. 1; + Master_V2 at Master_Byte range 2 .. 2; + Master_V3 at Master_Byte range 3 .. 3; + Master_V4 at Master_Byte range 4 .. 4; + Master_V5 at Master_Byte range 5 .. 5; + Master_V6 at Master_Byte range 6 .. 6; + Master_V7 at Master_Byte range 7 .. 7; + Slave_Control at Slave_Byte range 0 .. 0; + Slave_V1 at Slave_Byte range 1 .. 1; + Slave_V2 at Slave_Byte range 2 .. 2; + Slave_V3 at Slave_Byte range 3 .. 3; + Slave_V4 at Slave_Byte range 4 .. 4; + Slave_V5 at Slave_Byte range 5 .. 5; + Slave_V6 at Slave_Byte range 6 .. 6; + Slave_V7 at Slave_Byte range 7 .. 7; +end record; +@end example -@noindent Now to switch between machines, all that is necessary is -to set the boolean constant @code{Master_Byte_First} in +to set the boolean constant @cite{Master_Byte_First} in an appropriate manner. -@node Pragma Pack for Arrays +@node Pragma Pack for Arrays,Pragma Pack for Records,Effect of Bit_Order on Byte Ordering,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas pragma-pack-for-arrays}@anchor{22a}@anchor{gnat_rm/representation_clauses_and_pragmas id11}@anchor{22b} @section Pragma Pack for Arrays -@cindex Pragma Pack (for arrays) -@noindent -Pragma @code{Pack} applied to an array has no effect unless the component type + +@geindex Pragma Pack (for arrays) + +Pragma @cite{Pack} applied to an array has no effect unless the component type is packable. For a component type to be packable, it must be one of the following cases: -@itemize @bullet -@item + +@itemize * + +@item Any scalar type -@item + +@item Any type whose size is specified with a size clause -@item + +@item Any packed array type with a static size -@item + +@item Any record type padded because of its default alignment @end itemize -@noindent For all these cases, if the component subtype size is in the range -1 through 63, then the effect of the pragma @code{Pack} is exactly as though a +1 through 63, then the effect of the pragma @cite{Pack} is exactly as though a component size were specified giving the component subtype size. For example if we have: -@smallexample @c ada - type r is range 0 .. 17; +@example +type r is range 0 .. 17; - type ar is array (1 .. 8) of r; - pragma Pack (ar); -@end smallexample +type ar is array (1 .. 8) of r; +pragma Pack (ar); +@end example -@noindent -Then the component size of @code{ar} will be set to 5 (i.e.@: to @code{r'size}, -and the size of the array @code{ar} will be exactly 40 bits. +Then the component size of @cite{ar} will be set to 5 (i.e., to @cite{r'size}, +and the size of the array @cite{ar} will be exactly 40 bits. Note that in some cases this rather fierce approach to packing can produce unexpected effects. For example, in Ada 95 and Ada 2005, -subtype @code{Natural} typically has a size of 31, meaning that if you -pack an array of @code{Natural}, you get 31-bit +subtype @cite{Natural} typically has a size of 31, meaning that if you +pack an array of @cite{Natural}, you get 31-bit close packing, which saves a few bits, but results in far less efficient access. Since many other Ada compilers will ignore such a packing request, -GNAT will generate a warning on some uses of pragma @code{Pack} that it guesses +GNAT will generate a warning on some uses of pragma @cite{Pack} that it guesses might not be what is intended. You can easily remove this warning by -using an explicit @code{Component_Size} setting instead, which never generates +using an explicit @cite{Component_Size} setting instead, which never generates a warning, since the intention of the programmer is clear in this case. GNAT treats packed arrays in one of two ways. If the size of the array is @@ -16061,15 +18335,14 @@ an alignment of four bytes. If you explicitly override the default alignment with an alignment clause that is too small, the modular representation cannot be used. For example, consider the following set of declarations: -@smallexample @c ada - type R is range 1 .. 3; - type S is array (1 .. 31) of R; - for S'Component_Size use 2; - for S'Size use 62; - for S'Alignment use 1; -@end smallexample +@example +type R is range 1 .. 3; +type S is array (1 .. 31) of R; +for S'Component_Size use 2; +for S'Size use 62; +for S'Alignment use 1; +@end example -@noindent If the alignment clause were not present, then a 62-bit modular representation would be chosen (typically with an alignment of 4 or 8 bytes depending on the target). But the default alignment is overridden @@ -16079,64 +18352,66 @@ representation must be used, meaning that the length must be a multiple of 8. Thus the above set of declarations will result in a diagnostic rejecting the size clause and noting that the minimum size allowed is 64. -@cindex Pragma Pack (for type Natural) -@cindex Pragma Pack warning +@geindex Pragma Pack (for type Natural) + +@geindex Pragma Pack warning One special case that is worth noting occurs when the base type of the component size is 8/16/32 and the subtype is one bit less. Notably this -occurs with subtype @code{Natural}. Consider: +occurs with subtype @cite{Natural}. Consider: -@smallexample @c ada - type Arr is array (1 .. 32) of Natural; - pragma Pack (Arr); -@end smallexample +@example +type Arr is array (1 .. 32) of Natural; +pragma Pack (Arr); +@end example -@noindent In all commonly used Ada 83 compilers, this pragma Pack would be ignored, -since typically @code{Natural'Size} is 32 in Ada 83, and in any case most +since typically @cite{Natural'Size} is 32 in Ada 83, and in any case most Ada 83 compilers did not attempt 31 bit packing. -In Ada 95 and Ada 2005, @code{Natural'Size} is required to be 31. Furthermore, +In Ada 95 and Ada 2005, @cite{Natural'Size} is required to be 31. Furthermore, GNAT really does pack 31-bit subtype to 31 bits. This may result in a substantial unintended performance penalty when porting legacy Ada 83 code. To help prevent this, GNAT generates a warning in such cases. If you really want 31 bit packing in a case like this, you can set the component size explicitly: -@smallexample @c ada - type Arr is array (1 .. 32) of Natural; - for Arr'Component_Size use 31; -@end smallexample +@example +type Arr is array (1 .. 32) of Natural; +for Arr'Component_Size use 31; +@end example -@noindent Here 31-bit packing is achieved as required, and no warning is generated, since in this case the programmer intention is clear. -@node Pragma Pack for Records +@node Pragma Pack for Records,Record Representation Clauses,Pragma Pack for Arrays,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas pragma-pack-for-records}@anchor{22c}@anchor{gnat_rm/representation_clauses_and_pragmas id12}@anchor{22d} @section Pragma Pack for Records -@cindex Pragma Pack (for records) -@noindent -Pragma @code{Pack} applied to a record will pack the components to reduce + +@geindex Pragma Pack (for records) + +Pragma @cite{Pack} applied to a record will pack the components to reduce wasted space from alignment gaps and by reducing the amount of space taken by components. We distinguish between @emph{packable} components and @emph{non-packable} components. Components of the following types are considered packable: -@itemize @bullet -@item + + +@itemize * + +@item Components of a primitive type are packable unless they are aliased or of an atomic type. -@item +@item Small packed arrays, whose size does not exceed 64 bits, and where the size is statically known at compile time, are represented internally as modular integers, and so they are also packable. - @end itemize -@noindent All packable components occupy the exact number of bits corresponding to -their @code{Size} value, and are packed with no padding bits, i.e.@: they +their @cite{Size} value, and are packed with no padding bits, i.e., they can start on an arbitrary bit boundary. All other types are non-packable, they occupy an integral number of @@ -16145,30 +18420,29 @@ are placed at a boundary corresponding to their alignment requirements. For example, consider the record -@smallexample @c ada - type Rb1 is array (1 .. 13) of Boolean; - pragma Pack (Rb1); +@example +type Rb1 is array (1 .. 13) of Boolean; +pragma Pack (Rb1); - type Rb2 is array (1 .. 65) of Boolean; - pragma Pack (Rb2); +type Rb2 is array (1 .. 65) of Boolean; +pragma Pack (Rb2); - type AF is new Float with Atomic; +type AF is new Float with Atomic; - type X2 is record - L1 : Boolean; - L2 : Duration; - L3 : AF; - L4 : Boolean; - L5 : Rb1; - L6 : Rb2; - end record; - pragma Pack (X2); -@end smallexample +type X2 is record + L1 : Boolean; + L2 : Duration; + L3 : AF; + L4 : Boolean; + L5 : Rb1; + L6 : Rb2; +end record; +pragma Pack (X2); +@end example -@noindent The representation for the record X2 is as follows: -@smallexample @c ada +@example for X2'Size use 224; for X2 use record L1 at 0 range 0 .. 0; @@ -16178,33 +18452,35 @@ for X2 use record L5 at 16 range 1 .. 13; L6 at 18 range 0 .. 71; end record; -@end smallexample +@end example -@noindent -Studying this example, we see that the packable fields @code{L1} -and @code{L2} are +Studying this example, we see that the packable fields @cite{L1} +and @cite{L2} are of length equal to their sizes, and placed at specific bit boundaries (and not byte boundaries) to -eliminate padding. But @code{L3} is of a non-packable float type (because +eliminate padding. But @cite{L3} is of a non-packable float type (because it is aliased), so it is on the next appropriate alignment boundary. -The next two fields are fully packable, so @code{L4} and @code{L5} are -minimally packed with no gaps. However, type @code{Rb2} is a packed +The next two fields are fully packable, so @cite{L4} and @cite{L5} are +minimally packed with no gaps. However, type @cite{Rb2} is a packed array that is longer than 64 bits, so it is itself non-packable. Thus -the @code{L6} field is aligned to the next byte boundary, and takes an -integral number of bytes, i.e.@: 72 bits. +the @cite{L6} field is aligned to the next byte boundary, and takes an +integral number of bytes, i.e., 72 bits. -@node Record Representation Clauses +@node Record Representation Clauses,Handling of Records with Holes,Pragma Pack for Records,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id13}@anchor{22e}@anchor{gnat_rm/representation_clauses_and_pragmas record-representation-clauses}@anchor{22f} @section Record Representation Clauses -@cindex Record Representation Clause -@noindent + +@geindex Record Representation Clause + Record representation clauses may be given for all record types, including types obtained by record extension. Component clauses are allowed for any static component. The restrictions on component clauses depend on the type of the component. -@cindex Component Clause +@geindex Component Clause + For all components of an elementary type, the only restriction on component clauses is that the size must be at least the 'Size value of the type (actually the Value_Size). There are no restrictions due to alignment, @@ -16214,13 +18490,12 @@ Packed arrays with a size up to and including 64 bits are represented internally using a modular type with the appropriate number of bits, and thus the same lack of restriction applies. For example, if you declare: -@smallexample @c ada - type R is array (1 .. 49) of Boolean; - pragma Pack (R); - for R'Size use 49; -@end smallexample +@example +type R is array (1 .. 49) of Boolean; +pragma Pack (R); +for R'Size use 49; +@end example -@noindent then a component clause for a component of type R may start on any specified bit boundary, and may specify a value of 49 bits or greater. @@ -16230,7 +18505,7 @@ including the important case of single bits or boolean values, then there are no limitations on placement of such components, and they may start and end at arbitrary bit boundaries. -If the component size is not a power of 2 (e.g.@: 3 or 5), then +If the component size is not a power of 2 (e.g., 3 or 5), then an array of this type longer than 64 bits must always be placed on on a storage unit (byte) boundary and occupy an integral number of storage units (bytes). Any component clause that does not @@ -16253,24 +18528,23 @@ For all other component types, including non-bit-packed arrays, the component can be placed at an arbitrary bit boundary, so for example, the following is permitted: -@smallexample @c ada - type R is array (1 .. 10) of Boolean; - for R'Size use 80; +@example +type R is array (1 .. 10) of Boolean; +for R'Size use 80; - type Q is record - G, H : Boolean; - L, M : R; - end record; +type Q is record + G, H : Boolean; + L, M : R; +end record; - for Q use record - G at 0 range 0 .. 0; - H at 0 range 1 .. 1; - L at 0 range 2 .. 81; - R at 0 range 82 .. 161; - end record; -@end smallexample +for Q use record + G at 0 range 0 .. 0; + H at 0 range 1 .. 1; + L at 0 range 2 .. 81; + R at 0 range 82 .. 161; +end record; +@end example -@noindent Note: the above rules apply to recent releases of GNAT 5. In GNAT 3, there are more severe restrictions on larger components. For non-primitive types, including packed arrays with a size greater than @@ -16278,9 +18552,12 @@ For non-primitive types, including packed arrays with a size greater than type, in particular, always starting on a byte boundary, and the length must be a multiple of the storage unit. -@node Handling of Records with Holes +@node Handling of Records with Holes,Enumeration Clauses,Record Representation Clauses,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas handling-of-records-with-holes}@anchor{230}@anchor{gnat_rm/representation_clauses_and_pragmas id14}@anchor{231} @section Handling of Records with Holes -@cindex Handling of Records with Holes + + +@geindex Handling of Records with Holes As a result of alignment considerations, records may contain "holes" or gaps @@ -16301,21 +18578,20 @@ bits, then record objects for which this initialization is desired should be explicitly set to all zero values using Unchecked_Conversion or address overlays. For example -@smallexample @c ada +@example type HRec is record C : Character; I : Integer; end record; -@end smallexample +@end example -@noindent On typical machines, integers need to be aligned on a four-byte boundary, resulting in three bytes of undefined rubbish following the 8-bit field for C. To ensure that the hole in a variable of type HRec is set to all zero bits, you could for example do: -@smallexample @c ada +@example type Base is record Dummy1, Dummy2 : Integer := 0; end record; @@ -16323,14 +18599,13 @@ end record; BaseVar : Base; RealVar : Hrec; for RealVar'Address use BaseVar'Address; -@end smallexample +@end example -@noindent Now the 8-bytes of the value of RealVar start out containing all zero bits. A safer approach is to just define dummy fields, avoiding the holes, as in: -@smallexample @c ada +@example type HRec is record C : Character; Dummy1 : Short_Short_Integer := 0; @@ -16338,13 +18613,12 @@ type HRec is record Dummy3 : Short_Short_Integer := 0; I : Integer; end record; -@end smallexample +@end example -@noindent And to make absolutely sure that the intent of this is followed, you can use representation clauses: -@smallexample @c ada +@example for Hrec use record C at 0 range 0 .. 7; Dummy1 at 1 range 0 .. 7; @@ -16353,30 +18627,30 @@ for Hrec use record I at 4 range 0 .. 31; end record; for Hrec'Size use 64; -@end smallexample +@end example -@node Enumeration Clauses +@node Enumeration Clauses,Address Clauses,Handling of Records with Holes,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas enumeration-clauses}@anchor{232}@anchor{gnat_rm/representation_clauses_and_pragmas id15}@anchor{233} @section Enumeration Clauses + The only restriction on enumeration clauses is that the range of values must be representable. For the signed case, if one or more of the representation values are negative, all values must be in the range: -@smallexample @c ada - System.Min_Int .. System.Max_Int -@end smallexample +@example +System.Min_Int .. System.Max_Int +@end example -@noindent For the unsigned case, where all values are nonnegative, the values must be in the range: -@smallexample @c ada - 0 .. System.Max_Binary_Modulus; -@end smallexample +@example +0 .. System.Max_Binary_Modulus; +@end example -@noindent A @emph{confirming} representation clause is one in which the values range -from 0 in sequence, i.e.@: a clause that confirms the default representation +from 0 in sequence, i.e., a clause that confirms the default representation for an enumeration type. Such a confirming representation is permitted by these rules, and is specially recognized by the compiler so @@ -16386,72 +18660,74 @@ If an array has an index type which is an enumeration type to which an enumeration clause has been applied, then the array is stored in a compact manner. Consider the declarations: -@smallexample @c ada - type r is (A, B, C); - for r use (A => 1, B => 5, C => 10); - type t is array (r) of Character; -@end smallexample +@example +type r is (A, B, C); +for r use (A => 1, B => 5, C => 10); +type t is array (r) of Character; +@end example -@noindent The array type t corresponds to a vector with exactly three elements and -has a default size equal to @code{3*Character'Size}. This ensures efficient +has a default size equal to @cite{3*Character'Size}. This ensures efficient use of space, but means that accesses to elements of the array will incur the overhead of converting representation values to the corresponding -positional values, (i.e.@: the value delivered by the @code{Pos} attribute). +positional values, (i.e., the value delivered by the @cite{Pos} attribute). -@node Address Clauses +@node Address Clauses,Use of Address Clauses for Memory-Mapped I/O,Enumeration Clauses,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id16}@anchor{234}@anchor{gnat_rm/representation_clauses_and_pragmas address-clauses}@anchor{235} @section Address Clauses -@cindex Address Clause + + +@geindex Address Clause The reference manual allows a general restriction on representation clauses, as found in RM 13.1(22): @quotation -An implementation need not support representation + +"An implementation need not support representation items containing nonstatic expressions, except that an implementation should support a representation item for a given entity if each nonstatic expression in the representation item is a name that statically denotes -a constant declared before the entity. +a constant declared before the entity." @end quotation -@noindent In practice this is applicable only to address clauses, since this is the only case in which a non-static expression is permitted by the syntax. As the AARM notes in sections 13.1 (22.a-22.h): -@display - 22.a Reason: This is to avoid the following sort of thing: +@quotation - 22.b X : Integer := F(@dots{}); - Y : Address := G(@dots{}); - for X'Address use Y; +22.a Reason: This is to avoid the following sort of thing: - 22.c In the above, we have to evaluate the - initialization expression for X before we - know where to put the result. This seems - like an unreasonable implementation burden. +22.b X : Integer := F(...); +Y : Address := G(...); +for X'Address use Y; - 22.d The above code should instead be written - like this: +22.c In the above, we have to evaluate the +initialization expression for X before we +know where to put the result. This seems +like an unreasonable implementation burden. - 22.e Y : constant Address := G(@dots{}); - X : Integer := F(@dots{}); - for X'Address use Y; +22.d The above code should instead be written +like this: - 22.f This allows the expression ``Y'' to be safely - evaluated before X is created. +22.e Y : constant Address := G(...); +X : Integer := F(...); +for X'Address use Y; - 22.g The constant could be a formal parameter of mode in. +22.f This allows the expression 'Y' to be safely +evaluated before X is created. - 22.h An implementation can support other nonstatic - expressions if it wants to. Expressions of type - Address are hardly ever static, but their value - might be known at compile time anyway in many - cases. -@end display +22.g The constant could be a formal parameter of mode in. + +22.h An implementation can support other nonstatic +expressions if it wants to. Expressions of type +Address are hardly ever static, but their value +might be known at compile time anyway in many +cases. +@end quotation -@noindent GNAT does indeed permit many additional cases of non-static expressions. In particular, if the type involved is elementary there are no restrictions (since in this case, holding a temporary copy of the initialization value, @@ -16459,55 +18735,53 @@ if one is present, is inexpensive). In addition, if there is no implicit or explicit initialization, then there are no restrictions. GNAT will reject only the case where all three of these conditions hold: -@itemize @bullet -@item -The type of the item is non-elementary (e.g.@: a record or array). +@itemize * -@item +@item +The type of the item is non-elementary (e.g., a record or array). + +@item There is explicit or implicit initialization required for the object. Note that access values are always implicitly initialized. -@item +@item The address value is non-static. Here GNAT is more permissive than the RM, and allows the address value to be the address of a previously declared stand-alone variable, as long as it does not itself have an address clause. -@smallexample @c ada - Anchor : Some_Initialized_Type; - Overlay : Some_Initialized_Type; - for Overlay'Address use Anchor'Address; -@end smallexample +@example +Anchor : Some_Initialized_Type; +Overlay : Some_Initialized_Type; +for Overlay'Address use Anchor'Address; +@end example -@noindent However, the prefix of the address clause cannot be an array component, or a component of a discriminated record. - @end itemize -@noindent As noted above in section 22.h, address values are typically non-static. In particular the To_Address function, even if applied to a literal value, is a non-static function call. To avoid this minor annoyance, GNAT provides the implementation defined attribute 'To_Address. The following two expressions have identical values: -@findex Attribute -@findex To_Address -@smallexample @c ada - To_Address (16#1234_0000#) - System'To_Address (16#1234_0000#); -@end smallexample +@geindex Attribute + +@geindex To_Address + +@example +To_Address (16#1234_0000#) +System'To_Address (16#1234_0000#); +@end example -@noindent except that the second form is considered to be a static expression, and thus when used as an address clause value is always permitted. -@noindent Additionally, GNAT treats as static an address clause that is an unchecked_conversion of a static integer value. This simplifies the porting of legacy code, and provides a portable equivalent to the GNAT attribute -@code{To_Address}. +@cite{To_Address}. Another issue with address clauses is the interaction with alignment requirements. When an address clause is given for an object, the address @@ -16519,23 +18793,25 @@ program execution is erroneous. Since this source of erroneous behavior can have unfortunate effects, GNAT checks (at compile time if possible, generating a warning, or at execution time with a run-time check) that the alignment is appropriate. If the -run-time check fails, then @code{Program_Error} is raised. This run-time +run-time check fails, then @cite{Program_Error} is raised. This run-time check is suppressed if range checks are suppressed, or if the special GNAT check Alignment_Check is suppressed, or if -@code{pragma Restrictions (No_Elaboration_Code)} is in effect. +@cite{pragma Restrictions (No_Elaboration_Code)} is in effect. Finally, GNAT does not permit overlaying of objects of controlled types or composite types containing a controlled component. In most cases, the compiler can detect an attempt at such overlays and will generate a warning at compile time and a Program_Error exception at run time. -@findex Export +@geindex Export + An address clause cannot be given for an exported object. More understandably the real restriction is that objects with an address clause cannot be exported. This is because such variables are not defined by the Ada program, so there is no external object to export. -@findex Import +@geindex Import + It is permissible to give an address clause and a pragma Import for the same object. In this case, the variable is not really defined by the Ada program, so there is no external symbol to be linked. The link name @@ -16549,84 +18825,81 @@ means that the effect of the object declaration is to overwrite the memory at the specified address. This is almost always not what the programmer wants, so GNAT will output a warning: -@smallexample - with System; - package G is - type R is record - M : Integer := 0; - end record; - - Ext : R; - for Ext'Address use System'To_Address (16#1234_1234#); - | - >>> warning: implicit initialization of "Ext" may - modify overlaid storage - >>> warning: use pragma Import for "Ext" to suppress - initialization (RM B(24)) - - end G; -@end smallexample - -@noindent +@example +with System; +package G is + type R is record + M : Integer := 0; + end record; + + Ext : R; + for Ext'Address use System'To_Address (16#1234_1234#); + | +>>> warning: implicit initialization of "Ext" may + modify overlaid storage +>>> warning: use pragma Import for "Ext" to suppress + initialization (RM B(24)) + +end G; +@end example + As indicated by the warning message, the solution is to use a (dummy) pragma Import to suppress this initialization. The pragma tell the compiler that the object is declared and initialized elsewhere. The following package compiles without warnings (and the initialization is suppressed): -@smallexample @c ada - with System; - package G is - type R is record - M : Integer := 0; - end record; +@example +with System; +package G is + type R is record + M : Integer := 0; + end record; - Ext : R; - for Ext'Address use System'To_Address (16#1234_1234#); - pragma Import (Ada, Ext); - end G; -@end smallexample + Ext : R; + for Ext'Address use System'To_Address (16#1234_1234#); + pragma Import (Ada, Ext); +end G; +@end example -@noindent A final issue with address clauses involves their use for overlaying variables, as in the following example: -@cindex Overlaying of objects -@smallexample @c ada - A : Integer; - B : Integer; - for B'Address use A'Address; -@end smallexample +@geindex Overlaying of objects + +@example +A : Integer; +B : Integer; +for B'Address use A'Address; +@end example -@noindent or alternatively, using the form recommended by the RM: -@smallexample @c ada - A : Integer; - Addr : constant Address := A'Address; - B : Integer; - for B'Address use Addr; -@end smallexample +@example +A : Integer; +Addr : constant Address := A'Address; +B : Integer; +for B'Address use Addr; +@end example -@noindent -In both of these cases, @code{A} -and @code{B} become aliased to one another via the +In both of these cases, @cite{A} +and @cite{B} become aliased to one another via the address clause. This use of address clauses to overlay variables, achieving an effect similar to unchecked conversion was erroneous in Ada 83, but in Ada 95 and Ada 2005 the effect is implementation defined. Furthermore, the Ada RM specifically recommends that in a situation -like this, @code{B} should be subject to the following +like this, @cite{B} should be subject to the following implementation advice (RM 13.3(19)): @quotation -19 If the Address of an object is specified, or it is imported - or exported, then the implementation should not perform - optimizations based on assumptions of no aliases. + +"19 If the Address of an object is specified, or it is imported +or exported, then the implementation should not perform +optimizations based on assumptions of no aliases." @end quotation -@noindent GNAT follows this recommendation, and goes further by also applying -this recommendation to the overlaid variable (@code{A} +this recommendation to the overlaid variable (@cite{A} in the above example) in this case. This means that the overlay works "as expected", in that a modification to one of the variables will affect the value of the other. @@ -16634,7 +18907,7 @@ will affect the value of the other. Note that when address clause overlays are used in this way, there is an issue of unintentional initialization, as shown by this example: -@smallexample @c ada +@example package Overwrite_Record is type R is record A : Character := 'C'; @@ -16649,15 +18922,14 @@ package Overwrite_Record is suppress initialization (RM B.1(24)) end Overwrite_Record; -@end smallexample +@end example -@noindent -Here the default initialization of @code{Y} will clobber the value -of @code{X}, which justifies the warning. The warning notes that -this effect can be eliminated by adding a @code{pragma Import} +Here the default initialization of @cite{Y} will clobber the value +of @cite{X}, which justifies the warning. The warning notes that +this effect can be eliminated by adding a @cite{pragma Import} which suppresses the initialization: -@smallexample @c ada +@example package Overwrite_Record is type R is record A : Character := 'C'; @@ -16668,18 +18940,17 @@ package Overwrite_Record is for Y'Address use X'Address; pragma Import (Ada, Y); end Overwrite_Record; -@end smallexample +@end example -@noindent -Note that the use of @code{pragma Initialize_Scalars} may cause variables to +Note that the use of @cite{pragma Initialize_Scalars} may cause variables to be initialized when they would not otherwise have been in the absence of the use of this pragma. This may cause an overlay to have this unintended clobbering effect. The compiler avoids this for scalar types, but not for composite objects (where in general the effect -of @code{Initialize_Scalars} is part of the initialization routine +of @cite{Initialize_Scalars} is part of the initialization routine for the composite object: -@smallexample @c ada +@example pragma Initialize_Scalars; with Ada.Text_IO; use Ada.Text_IO; procedure Overwrite_Array is @@ -16699,14 +18970,13 @@ begin Put_Line ("X was not clobbered"); end if; end Overwrite_Array; -@end smallexample +@end example -@noindent The above program generates the warning as shown, and at execution -time, prints @code{X was clobbered}. If the @code{pragma Import} is +time, prints @cite{X was clobbered}. If the @cite{pragma Import} is added as suggested: -@smallexample @c ada +@example pragma Initialize_Scalars; with Ada.Text_IO; use Ada.Text_IO; procedure Overwrite_Array is @@ -16722,36 +18992,37 @@ begin Put_Line ("X was not clobbered"); end if; end Overwrite_Array; -@end smallexample +@end example -@noindent then the program compiles without the warning and when run will generate -the output @code{X was not clobbered}. +the output @cite{X was not clobbered}. -@node Use of Address Clauses for Memory-Mapped I/O +@node Use of Address Clauses for Memory-Mapped I/O,Effect of Convention on Representation,Address Clauses,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id17}@anchor{236}@anchor{gnat_rm/representation_clauses_and_pragmas use-of-address-clauses-for-memory-mapped-i-o}@anchor{237} @section Use of Address Clauses for Memory-Mapped I/O -@cindex Memory-mapped I/O + + +@geindex Memory-mapped I/O A common pattern is to use an address clause to map an atomic variable to a location in memory that corresponds to a memory-mapped I/O operation or operations, for example: -@smallexample @c ada - type Mem_Word is record - A,B,C,D : Byte; - end record; - pragma Atomic (Mem_Word); - for Mem_Word_Size use 32; - - Mem : Mem_Word; - for Mem'Address use some-address; - ... - Temp := Mem; - Temp.A := 32; - Mem := Temp; -@end smallexample - -@noindent +@example +type Mem_Word is record + A,B,C,D : Byte; +end record; +pragma Atomic (Mem_Word); +for Mem_Word_Size use 32; + +Mem : Mem_Word; +for Mem'Address use some-address; +... +Temp := Mem; +Temp.A := 32; +Mem := Temp; +@end example + For a full access (reference or modification) of the variable (Mem) in this case, as in the above examples, GNAT guarantees that the entire atomic word will be accessed. It is not clear whether the RM requires this. For @@ -16761,11 +19032,10 @@ guarantee that for such a reference, the entire word is read or written. A problem arises with a component access such as: -@smallexample @c ada - Mem.A := 32; -@end smallexample +@example +Mem.A := 32; +@end example -@noindent Note that the component A is not declared as atomic. This means that it is not clear what this assignment means. It could correspond to full word read and write as given in the first example, or on architectures that supported @@ -16774,54 +19044,60 @@ not have anything to say in this situation, and GNAT does not make any guarantee. The code generated may vary from target to target. GNAT will issue a warning in such a case: -@smallexample @c ada - Mem.A := 32; - | - >>> warning: access to non-atomic component of atomic array, - may cause unexpected accesses to atomic object -@end smallexample +@example +Mem.A := 32; +| +>>> warning: access to non-atomic component of atomic array, + may cause unexpected accesses to atomic object +@end example -@noindent It is best to be explicit in this situation, by either declaring the components to be atomic if you want the byte store, or explicitly writing the full word access sequence if that is what the hardware requires. -@node Effect of Convention on Representation +@node Effect of Convention on Representation,Conventions and Anonymous Access Types,Use of Address Clauses for Memory-Mapped I/O,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id18}@anchor{238}@anchor{gnat_rm/representation_clauses_and_pragmas effect-of-convention-on-representation}@anchor{239} @section Effect of Convention on Representation -@cindex Convention, effect on representation -@noindent + +@geindex Convention +@geindex effect on representation + Normally the specification of a foreign language convention for a type or an object has no effect on the chosen representation. In particular, the representation chosen for data in GNAT generally meets the standard system conventions, and for example records are laid out in a manner that is -consistent with C@. This means that specifying convention C (for example) +consistent with C. This means that specifying convention C (for example) has no effect. There are four exceptions to this general rule: -@itemize @bullet -@item Convention Fortran and array subtypes +@itemize * + +@item +@emph{Convention Fortran and array subtypes}. + If pragma Convention Fortran is specified for an array subtype, then in accordance with the implementation advice in section 3.6.2(11) of the Ada Reference Manual, the array will be stored in a Fortran-compatible column-major manner, instead of the normal default row-major order. -@item Convention C and enumeration types +@item +@emph{Convention C and enumeration types} + GNAT normally stores enumeration types in 8, 16, or 32 bits as required to accommodate all values of the type. For example, for the enumeration type declared by: -@smallexample @c ada - type Color is (Red, Green, Blue); -@end smallexample +@example +type Color is (Red, Green, Blue); +@end example -@noindent 8 bits is sufficient to store all values of the type, so by default, objects -of type @code{Color} will be represented using 8 bits. However, normal C +of type @cite{Color} will be represented using 8 bits. However, normal C convention is to use 32 bits for all enum values in C, since enum values -are essentially of type int. If pragma @code{Convention C} is specified for an +are essentially of type int. If pragma @cite{Convention C} is specified for an Ada enumeration type, then the size is modified as necessary (usually to 32 bits) to be consistent with the C convention for enum values. @@ -16833,42 +19109,38 @@ Since this may be a surprise in terms of what C expects, GNAT will issue a warning in this situation. The warning can be suppressed by giving an explicit size clause specifying the desired size. -@item Convention C/Fortran and Boolean types +@item +@emph{Convention C/Fortran and Boolean types} + In C, the usual convention for boolean values, that is values used for conditions, is that zero represents false, and nonzero values represent true. In Ada, the normal convention is that two specific values, typically 0/1, are used to represent false/true respectively. -Fortran has a similar convention for @code{LOGICAL} values (any nonzero +Fortran has a similar convention for @cite{LOGICAL} values (any nonzero value represents true). To accommodate the Fortran and C conventions, if a pragma Convention specifies C or Fortran convention for a derived Boolean, as in the following example: -@smallexample @c ada - type C_Switch is new Boolean; - pragma Convention (C, C_Switch); -@end smallexample +@example +type C_Switch is new Boolean; +pragma Convention (C, C_Switch); +@end example -@noindent then the GNAT generated code will treat any nonzero value as true. For truth values generated by GNAT, the conventional value 1 will be used for True, but when one of these values is read, any nonzero value is treated as True. - -@item Access types on OpenVMS -For 64-bit OpenVMS systems, access types (other than those for unconstrained -arrays) are 64-bits long. An exception to this rule is for the case of -C-convention access types where there is no explicit size clause present (or -inherited for derived types). In this case, GNAT chooses to make these -pointers 32-bits, which provides an easier path for migration of 32-bit legacy -code. size clause specifying 64-bits must be used to obtain a 64-bit pointer. - @end itemize -@node Conventions and Anonymous Access Types +@node Conventions and Anonymous Access Types,Determining the Representations chosen by GNAT,Effect of Convention on Representation,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas conventions-and-anonymous-access-types}@anchor{23a}@anchor{gnat_rm/representation_clauses_and_pragmas id19}@anchor{23b} @section Conventions and Anonymous Access Types -@cindex Anonymous access types -@cindex Convention for anonymous access types + + +@geindex Anonymous access types + +@geindex Convention for anonymous access types The RM is not entirely clear on convention handling in a number of cases, and in particular, it is not clear on the convention to be given to @@ -16889,7 +19161,7 @@ anonymous access type which do not have an explicitly specified convention. The following program shows these conventions in action: -@smallexample @c ada +@example package ConvComp is type Foo is range 1 .. 10; type T1 is record @@ -16935,14 +19207,18 @@ package ConvComp is >>> subprogram "F" has wrong convention >>> does not match access to subprogram declared at line 24 39. end ConvComp; -@end smallexample +@end example -@node Determining the Representations chosen by GNAT +@node Determining the Representations chosen by GNAT,,Conventions and Anonymous Access Types,Representation Clauses and Pragmas +@anchor{gnat_rm/representation_clauses_and_pragmas id20}@anchor{23c}@anchor{gnat_rm/representation_clauses_and_pragmas determining-the-representations-chosen-by-gnat}@anchor{23d} @section Determining the Representations chosen by GNAT -@cindex Representation, determination of -@cindex @option{-gnatR} switch -@noindent + +@geindex Representation +@geindex determination of + +@geindex -gnatR (gcc) + Although the descriptions in this section are intended to be complete, it is often easier to simply experiment to see what GNAT accepts and what the effect is on the layout of types and objects. @@ -16953,17 +19229,17 @@ representation clause or pragma is accepted, there can still be questions of what the compiler actually does. For example, if a partial record representation clause specifies the location of some components and not others, then where are the non-specified components placed? Or if pragma -@code{Pack} is used on a record, then exactly where are the resulting -fields placed? The section on pragma @code{Pack} in this chapter can be +@cite{Pack} is used on a record, then exactly where are the resulting +fields placed? The section on pragma @cite{Pack} in this chapter can be used to answer the second question, but it is often easier to just see what the compiler does. -For this purpose, GNAT provides the option @option{-gnatR}. If you compile +For this purpose, GNAT provides the option @emph{-gnatR}. If you compile with this option, then the compiler will output information on the actual representations chosen, in a format similar to source representation clauses. For example, if we compile the package: -@smallexample @c ada +@example package q is type r (x : boolean) is tagged record case x is @@ -17005,12 +19281,11 @@ package q is end record; pragma Pack (x2); end q; -@end smallexample +@end example -@noindent -using the switch @option{-gnatR} we obtain the following output: +using the switch @emph{-gnatR} we obtain the following output: -@smallexample +@example Representation information for unit q ------------------------------------- @@ -17059,12 +19334,11 @@ for x2 use record l5 at 16 range 1 .. 13; l6 at 18 range 0 .. 71; end record; -@end smallexample +@end example -@noindent -The Size values are actually the Object_Size, i.e.@: the default size that +The Size values are actually the Object_Size, i.e., the default size that will be allocated for objects of the type. -The ?? size for type r indicates that we have a variant record, and the +The @code{??} size for type r indicates that we have a variant record, and the actual size of objects will depend on the discriminant value. The Alignment values show the actual alignment chosen by the compiler @@ -17076,21 +19350,22 @@ cannot be controlled by the programmer). The record representation clause for the type extension r2 shows all the fields present, including the parent field, which is a copy of the fields -of the parent type of r2, i.e.@: r1. +of the parent type of r2, i.e., r1. The component size and size clauses for types rb1 and rb2 show -the exact effect of pragma @code{Pack} on these arrays, and the record -representation clause for type x2 shows how pragma @code{Pack} affects +the exact effect of pragma @cite{Pack} on these arrays, and the record +representation clause for type x2 shows how pragma @cite{Pack} affects this record type. In some cases, it may be useful to cut and paste the representation clauses generated by the compiler into the original source to fix and guarantee the actual representation to be used. -@node Standard Library Routines +@node Standard Library Routines,The Implementation of Standard I/O,Representation Clauses and Pragmas,Top +@anchor{gnat_rm/standard_library_routines standard-library-routines}@anchor{e}@anchor{gnat_rm/standard_library_routines doc}@anchor{23e}@anchor{gnat_rm/standard_library_routines id1}@anchor{23f} @chapter Standard Library Routines -@noindent + The Ada Reference Manual contains in Annex A a full description of an extensive set of standard library routines that can be used in any Ada program, and which must be provided by all Ada compilers. They are @@ -17101,7 +19376,7 @@ purposes the description in the Ada Reference Manual, or appropriate Ada text book, will be sufficient for making use of these facilities. In the case of the input-output facilities, -@xref{The Implementation of Standard I/O}, +@ref{f,,The Implementation of Standard I/O}, gives details on exactly how GNAT interfaces to the file system. For the remaining packages, the Ada Reference Manual should be sufficient. The following is a list of the packages included, @@ -17115,381 +19390,491 @@ are not implemented, as marked by the presence of pragma Unimplemented_Unit, and in this case the package declaration contains comments explaining why the unit is not implemented. -@table @code -@item Ada (A.2) + +@table @asis + +@item @code{Ada} @emph{(A.2)} + This is a parent package for all the standard library packages. It is usually included implicitly in your program, and itself contains no useful data or routines. -@item Ada.Assertions (11.4.2) -@code{Assertions} provides the @code{Assert} subprograms, and also -the declaration of the @code{Assertion_Error} exception. +@item @code{Ada.Assertions} @emph{(11.4.2)} + +@cite{Assertions} provides the @cite{Assert} subprograms, and also +the declaration of the @cite{Assertion_Error} exception. + +@item @code{Ada.Asynchronous_Task_Control} @emph{(D.11)} -@item Ada.Asynchronous_Task_Control (D.11) -@code{Asynchronous_Task_Control} provides low level facilities for task +@cite{Asynchronous_Task_Control} provides low level facilities for task synchronization. It is typically not implemented. See package spec for details. -@item Ada.Calendar (9.6) -@code{Calendar} provides time of day access, and routines for +@item @code{Ada.Calendar} @emph{(9.6)} + +@cite{Calendar} provides time of day access, and routines for manipulating times and durations. -@item Ada.Calendar.Arithmetic (9.6.1) +@item @code{Ada.Calendar.Arithmetic} @emph{(9.6.1)} + This package provides additional arithmetic -operations for @code{Calendar}. +operations for @cite{Calendar}. -@item Ada.Calendar.Formatting (9.6.1) -This package provides formatting operations for @code{Calendar}. +@item @code{Ada.Calendar.Formatting} @emph{(9.6.1)} -@item Ada.Calendar.Time_Zones (9.6.1) -This package provides additional @code{Calendar} facilities +This package provides formatting operations for @cite{Calendar}. + +@item @code{Ada.Calendar.Time_Zones} @emph{(9.6.1)} + +This package provides additional @cite{Calendar} facilities for handling time zones. -@item Ada.Characters (A.3.1) +@item @code{Ada.Characters} @emph{(A.3.1)} + This is a dummy parent package that contains no useful entities -@item Ada.Characters.Conversions (A.3.2) +@item @code{Ada.Characters.Conversions} @emph{(A.3.2)} + This package provides character conversion functions. -@item Ada.Characters.Handling (A.3.2) +@item @code{Ada.Characters.Handling} @emph{(A.3.2)} + This package provides some basic character handling capabilities, -including classification functions for classes of characters (e.g.@: test +including classification functions for classes of characters (e.g., test for letters, or digits). -@item Ada.Characters.Latin_1 (A.3.3) +@item @code{Ada.Characters.Latin_1} @emph{(A.3.3)} + This package includes a complete set of definitions of the characters -that appear in type CHARACTER@. It is useful for writing programs that +that appear in type CHARACTER. It is useful for writing programs that will run in international environments. For example, if you want an upper case E with an acute accent in a string, it is often better to use -the definition of @code{UC_E_Acute} in this package. Then your program +the definition of @cite{UC_E_Acute} in this package. Then your program will print in an understandable manner even if your environment does not support these extended characters. -@item Ada.Command_Line (A.15) +@item @code{Ada.Command_Line} @emph{(A.15)} + This package provides access to the command line parameters and the name -of the current program (analogous to the use of @code{argc} and @code{argv} +of the current program (analogous to the use of @cite{argc} and @cite{argv} in C), and also allows the exit status for the program to be set in a system-independent manner. -@item Ada.Complex_Text_IO (G.1.3) +@item @code{Ada.Complex_Text_IO} @emph{(G.1.3)} + This package provides text input and output of complex numbers. -@item Ada.Containers (A.18.1) +@item @code{Ada.Containers} @emph{(A.18.1)} + A top level package providing a few basic definitions used by all the following specific child packages that provide specific kinds of containers. +@end table + +@code{Ada.Containers.Bounded_Priority_Queues} @emph{(A.18.31)} -@item Ada.Containers.Bounded_Priority_Queues (A.18.31) +@code{Ada.Containers.Bounded_Synchronized_Queues} @emph{(A.18.29)} -@item Ada.Containers.Bounded_Synchronized_Queues (A.18.29) +@code{Ada.Containers.Doubly_Linked_Lists} @emph{(A.18.3)} -@item Ada.Containers.Doubly_Linked_Lists (A.18.3) +@code{Ada.Containers.Generic_Array_Sort} @emph{(A.18.26)} -@item Ada.Containers.Generic_Array_Sort (A.18.26) +@code{Ada.Containers.Generic_Constrained_Array_Sort} @emph{(A.18.26)} -@item Ada.Containers.Generic_Constrained_Array_Sort (A.18.26) +@code{Ada.Containers.Generic_Sort} @emph{(A.18.26)} -@item Ada.Containers.Generic_Sort (A.18.26) +@code{Ada.Containers.Hashed_Maps} @emph{(A.18.5)} -@item Ada.Containers.Hashed_Maps (A.18.5) +@code{Ada.Containers.Hashed_Sets} @emph{(A.18.8)} -@item Ada.Containers.Hashed_Sets (A.18.8) +@code{Ada.Containers.Indefinite_Doubly_Linked_Lists} @emph{(A.18.12)} -@item Ada.Containers.Indefinite_Doubly_Linked_Lists (A.18.12) +@code{Ada.Containers.Indefinite_Hashed_Maps} @emph{(A.18.13)} -@item Ada.Containers.Indefinite_Hashed_Maps (A.18.13) +@code{Ada.Containers.Indefinite_Hashed_Sets} @emph{(A.18.15)} -@item Ada.Containers.Indefinite_Hashed_Sets (A.18.15) +@code{Ada.Containers.Indefinite_Holders} @emph{(A.18.18)} -@item Ada.Containers.Indefinite_Holders (A.18.18) +@code{Ada.Containers.Indefinite_Multiway_Trees} @emph{(A.18.17)} -@item Ada.Containers.Indefinite_Multiway_Trees (A.18.17) +@code{Ada.Containers.Indefinite_Ordered_Maps} @emph{(A.18.14)} -@item Ada.Containers.Indefinite_Ordered_Maps (A.18.14) +@code{Ada.Containers.Indefinite_Ordered_Sets} @emph{(A.18.16)} -@item Ada.Containers.Indefinite_Ordered_Sets (A.18.16) +@code{Ada.Containers.Indefinite_Vectors} @emph{(A.18.11)} -@item Ada.Containers.Indefinite_Vectors (A.18.11) +@code{Ada.Containers.Multiway_Trees} @emph{(A.18.10)} -@item Ada.Containers.Multiway_Trees (A.18.10) +@code{Ada.Containers.Ordered_Maps} @emph{(A.18.6)} -@item Ada.Containers.Ordered_Maps (A.18.6) +@code{Ada.Containers.Ordered_Sets} @emph{(A.18.9)} -@item Ada.Containers.Ordered_Sets (A.18.9) +@code{Ada.Containers.Synchronized_Queue_Interfaces} @emph{(A.18.27)} -@item Ada.Containers.Synchronized_Queue_Interfaces (A.18.27) +@code{Ada.Containers.Unbounded_Priority_Queues} @emph{(A.18.30)} -@item Ada.Containers.Unbounded_Priority_Queues (A.18.30) +@code{Ada.Containers.Unbounded_Synchronized_Queues} @emph{(A.18.28)} -@item Ada.Containers.Unbounded_Synchronized_Queues (A.18.28) +@code{Ada.Containers.Vectors} @emph{(A.18.2)} -@item Ada.Containers.Vectors (A.18.2) -@item Ada.Directories (A.16) +@table @asis + +@item @code{Ada.Directories} @emph{(A.16)} + This package provides operations on directories. -@item Ada.Directories.Hierarchical_File_Names (A.16.1) +@item @code{Ada.Directories.Hierarchical_File_Names} @emph{(A.16.1)} + This package provides additional directory operations handling hiearchical file names. -@item Ada.Directories.Information (A.16) +@item @code{Ada.Directories.Information} @emph{(A.16)} + This is an implementation defined package for additional directory operations, which is not implemented in GNAT. -@item Ada.Decimal (F.2) +@item @code{Ada.Decimal} @emph{(F.2)} + This package provides constants describing the range of decimal numbers implemented, and also a decimal divide routine (analogous to the COBOL -verb DIVIDE @dots{} GIVING @dots{} REMAINDER @dots{}) +verb DIVIDE ... GIVING ... REMAINDER ...) + +@item @code{Ada.Direct_IO} @emph{(A.8.4)} -@item Ada.Direct_IO (A.8.4) This package provides input-output using a model of a set of records of fixed-length, containing an arbitrary definite Ada type, indexed by an integer record number. -@item Ada.Dispatching (D.2.1) +@item @code{Ada.Dispatching} @emph{(D.2.1)} + A parent package containing definitions for task dispatching operations. -@item Ada.Dispatching.EDF (D.2.6) +@item @code{Ada.Dispatching.EDF} @emph{(D.2.6)} + Not implemented in GNAT. -@item Ada.Dispatching.Non_Preemptive (D.2.4) +@item @code{Ada.Dispatching.Non_Preemptive} @emph{(D.2.4)} + Not implemented in GNAT. -@item Ada.Dispatching.Round_Robin (D.2.5) +@item @code{Ada.Dispatching.Round_Robin} @emph{(D.2.5)} + Not implemented in GNAT. -@item Ada.Dynamic_Priorities (D.5) +@item @code{Ada.Dynamic_Priorities} @emph{(D.5)} + This package allows the priorities of a task to be adjusted dynamically as the task is running. -@item Ada.Environment_Variables (A.17) +@item @code{Ada.Environment_Variables} @emph{(A.17)} + This package provides facilities for accessing environment variables. -@item Ada.Exceptions (11.4.1) +@item @code{Ada.Exceptions} @emph{(11.4.1)} + This package provides additional information on exceptions, and also contains facilities for treating exceptions as data objects, and raising exceptions with associated messages. -@item Ada.Execution_Time (D.14) +@item @code{Ada.Execution_Time} @emph{(D.14)} + Not implemented in GNAT. -@item Ada.Execution_Time.Group_Budgets (D.14.2) +@item @code{Ada.Execution_Time.Group_Budgets} @emph{(D.14.2)} + Not implemented in GNAT. -@item Ada.Execution_Time.Timers (D.14.1)' +@item @code{Ada.Execution_Time.Timers} @emph{(D.14.1)'} + Not implemented in GNAT. -@item Ada.Finalization (7.6) +@item @code{Ada.Finalization} @emph{(7.6)} + This package contains the declarations and subprograms to support the use of controlled types, providing for automatic initialization and finalization (analogous to the constructors and destructors of C++). -@item Ada.Float_Text_IO (A.10.9) +@item @code{Ada.Float_Text_IO} @emph{(A.10.9)} + A library level instantiation of Text_IO.Float_IO for type Float. -@item Ada.Float_Wide_Text_IO (A.10.9) +@item @code{Ada.Float_Wide_Text_IO} @emph{(A.10.9)} + A library level instantiation of Wide_Text_IO.Float_IO for type Float. -@item Ada.Float_Wide_Wide_Text_IO (A.10.9) +@item @code{Ada.Float_Wide_Wide_Text_IO} @emph{(A.10.9)} + A library level instantiation of Wide_Wide_Text_IO.Float_IO for type Float. -@item Ada.Integer_Text_IO (A.10.9) +@item @code{Ada.Integer_Text_IO} @emph{(A.10.9)} + A library level instantiation of Text_IO.Integer_IO for type Integer. -@item Ada.Integer_Wide_Text_IO (A.10.9) +@item @code{Ada.Integer_Wide_Text_IO} @emph{(A.10.9)} + A library level instantiation of Wide_Text_IO.Integer_IO for type Integer. -@item Ada.Integer_Wide_Wide_Text_IO (A.10.9) +@item @code{Ada.Integer_Wide_Wide_Text_IO} @emph{(A.10.9)} + A library level instantiation of Wide_Wide_Text_IO.Integer_IO for type Integer. -@item Ada.Interrupts (C.3.2) +@item @code{Ada.Interrupts} @emph{(C.3.2)} + This package provides facilities for interfacing to interrupts, which includes the set of signals or conditions that can be raised and recognized as interrupts. -@item Ada.Interrupts.Names (C.3.2) +@item @code{Ada.Interrupts.Names} @emph{(C.3.2)} + This package provides the set of interrupt names (actually signal -or condition names) that can be handled by GNAT@. +or condition names) that can be handled by GNAT. + +@item @code{Ada.IO_Exceptions} @emph{(A.13)} -@item Ada.IO_Exceptions (A.13) This package defines the set of exceptions that can be raised by use of the standard IO packages. -@item Ada.Iterator_Interfaces (5.5.1) +@item @code{Ada.Iterator_Interfaces} @emph{(5.5.1)} + This package provides a generic interface to generalized iterators. -@item Ada.Locales (A.19) +@item @code{Ada.Locales} @emph{(A.19)} + This package provides declarations providing information (Language and Country) about the current locale. -@item Ada.Numerics +@item @code{Ada.Numerics} + This package contains some standard constants and exceptions used throughout the numerics packages. Note that the constants pi and e are defined here, and it is better to use these definitions than rolling your own. -@item Ada.Numerics.Complex_Arrays (G.3.2) +@item @code{Ada.Numerics.Complex_Arrays} @emph{(G.3.2)} + Provides operations on arrays of complex numbers. -@item Ada.Numerics.Complex_Elementary_Functions +@item @code{Ada.Numerics.Complex_Elementary_Functions} + Provides the implementation of standard elementary functions (such as log and trigonometric functions) operating on complex numbers using the -standard @code{Float} and the @code{Complex} and @code{Imaginary} types -created by the package @code{Numerics.Complex_Types}. +standard @cite{Float} and the @cite{Complex} and @cite{Imaginary} types +created by the package @cite{Numerics.Complex_Types}. + +@item @code{Ada.Numerics.Complex_Types} -@item Ada.Numerics.Complex_Types This is a predefined instantiation of -@code{Numerics.Generic_Complex_Types} using @code{Standard.Float} to -build the type @code{Complex} and @code{Imaginary}. +@cite{Numerics.Generic_Complex_Types} using @cite{Standard.Float} to +build the type @cite{Complex} and @cite{Imaginary}. + +@item @code{Ada.Numerics.Discrete_Random} -@item Ada.Numerics.Discrete_Random This generic package provides a random number generator suitable for generating uniformly distributed values of a specified discrete subtype. -@item Ada.Numerics.Float_Random +@item @code{Ada.Numerics.Float_Random} + This package provides a random number generator suitable for generating uniformly distributed floating point values in the unit interval. -@item Ada.Numerics.Generic_Complex_Elementary_Functions +@item @code{Ada.Numerics.Generic_Complex_Elementary_Functions} + This is a generic version of the package that provides the implementation of standard elementary functions (such as log and trigonometric functions) for an arbitrary complex type. The following predefined instantiations of this package are provided: -@table @code -@item Short_Float -@code{Ada.Numerics.Short_Complex_Elementary_Functions} -@item Float -@code{Ada.Numerics.Complex_Elementary_Functions} -@item Long_Float -@code{Ada.Numerics.Long_Complex_Elementary_Functions} -@end table -@item Ada.Numerics.Generic_Complex_Types +@itemize * + +@item +@code{Short_Float} + +@cite{Ada.Numerics.Short_Complex_Elementary_Functions} + +@item +@code{Float} + +@cite{Ada.Numerics.Complex_Elementary_Functions} + +@item +@code{Long_Float} + +@cite{Ada.Numerics.Long_Complex_Elementary_Functions} +@end itemize + +@item @code{Ada.Numerics.Generic_Complex_Types} + This is a generic package that allows the creation of complex types, with associated complex arithmetic operations. The following predefined instantiations of this package exist -@table @code -@item Short_Float -@code{Ada.Numerics.Short_Complex_Complex_Types} -@item Float -@code{Ada.Numerics.Complex_Complex_Types} -@item Long_Float -@code{Ada.Numerics.Long_Complex_Complex_Types} -@end table -@item Ada.Numerics.Generic_Elementary_Functions + +@itemize * + +@item +@code{Short_Float} + +@cite{Ada.Numerics.Short_Complex_Complex_Types} + +@item +@code{Float} + +@cite{Ada.Numerics.Complex_Complex_Types} + +@item +@code{Long_Float} + +@cite{Ada.Numerics.Long_Complex_Complex_Types} +@end itemize + +@item @code{Ada.Numerics.Generic_Elementary_Functions} + This is a generic package that provides the implementation of standard elementary functions (such as log an trigonometric functions) for an arbitrary float type. The following predefined instantiations of this package exist -@table @code -@item Short_Float -@code{Ada.Numerics.Short_Elementary_Functions} -@item Float -@code{Ada.Numerics.Elementary_Functions} -@item Long_Float -@code{Ada.Numerics.Long_Elementary_Functions} -@end table -@item Ada.Numerics.Generic_Real_Arrays (G.3.1) +@itemize * + +@item +@code{Short_Float} + +@cite{Ada.Numerics.Short_Elementary_Functions} + +@item +@code{Float} + +@cite{Ada.Numerics.Elementary_Functions} + +@item +@code{Long_Float} + +@cite{Ada.Numerics.Long_Elementary_Functions} +@end itemize + +@item @code{Ada.Numerics.Generic_Real_Arrays} @emph{(G.3.1)} + Generic operations on arrays of reals -@item Ada.Numerics.Real_Arrays (G.3.1) +@item @code{Ada.Numerics.Real_Arrays} @emph{(G.3.1)} + Preinstantiation of Ada.Numerics.Generic_Real_Arrays (Float). -@item Ada.Real_Time (D.8) -This package provides facilities similar to those of @code{Calendar}, but +@item @code{Ada.Real_Time} @emph{(D.8)} + +This package provides facilities similar to those of @cite{Calendar}, but operating with a finer clock suitable for real time control. Note that annex D requires that there be no backward clock jumps, and GNAT generally guarantees this behavior, but of course if the external clock on which the GNAT runtime depends is deliberately reset by some external event, then such a backward jump may occur. -@item Ada.Real_Time.Timing_Events (D.15) +@item @code{Ada.Real_Time.Timing_Events} @emph{(D.15)} + Not implemented in GNAT. -@item Ada.Sequential_IO (A.8.1) +@item @code{Ada.Sequential_IO} @emph{(A.8.1)} + This package provides input-output facilities for sequential files, which can contain a sequence of values of a single type, which can be any Ada type, including indefinite (unconstrained) types. -@item Ada.Storage_IO (A.9) +@item @code{Ada.Storage_IO} @emph{(A.9)} + This package provides a facility for mapping arbitrary Ada types to and from a storage buffer. It is primarily intended for the creation of new IO packages. -@item Ada.Streams (13.13.1) +@item @code{Ada.Streams} @emph{(13.13.1)} + This is a generic package that provides the basic support for the -concept of streams as used by the stream attributes (@code{Input}, -@code{Output}, @code{Read} and @code{Write}). +concept of streams as used by the stream attributes (@cite{Input}, +@cite{Output}, @cite{Read} and @cite{Write}). + +@item @code{Ada.Streams.Stream_IO} @emph{(A.12.1)} -@item Ada.Streams.Stream_IO (A.12.1) -This package is a specialization of the type @code{Streams} defined in -package @code{Streams} together with a set of operations providing +This package is a specialization of the type @cite{Streams} defined in +package @cite{Streams} together with a set of operations providing Stream_IO capability. The Stream_IO model permits both random and sequential access to a file which can contain an arbitrary set of values of one or more Ada types. -@item Ada.Strings (A.4.1) +@item @code{Ada.Strings} @emph{(A.4.1)} + This package provides some basic constants used by the string handling packages. -@item Ada.Strings.Bounded (A.4.4) +@item @code{Ada.Strings.Bounded} @emph{(A.4.4)} + This package provides facilities for handling variable length strings. The bounded model requires a maximum length. It is thus somewhat more limited than the unbounded model, but avoids the use of dynamic allocation or finalization. -@item Ada.Strings.Bounded.Equal_Case_Insensitive (A.4.10) +@item @code{Ada.Strings.Bounded.Equal_Case_Insensitive} @emph{(A.4.10)} + Provides case-insensitive comparisons of bounded strings -@item Ada.Strings.Bounded.Hash (A.4.9) +@item @code{Ada.Strings.Bounded.Hash} @emph{(A.4.9)} + This package provides a generic hash function for bounded strings -@item Ada.Strings.Bounded.Hash_Case_Insensitive (A.4.9) +@item @code{Ada.Strings.Bounded.Hash_Case_Insensitive} @emph{(A.4.9)} + This package provides a generic hash function for bounded strings that converts the string to be hashed to lower case. -@item Ada.Strings.Bounded.Less_Case_Insensitive (A.4.10) +@item @code{Ada.Strings.Bounded.Less_Case_Insensitive} @emph{(A.4.10)} + This package provides a comparison function for bounded strings that works in a case insensitive manner by converting to lower case before the comparison. -@item Ada.Strings.Fixed (A.4.3) +@item @code{Ada.Strings.Fixed} @emph{(A.4.3)} + This package provides facilities for handling fixed length strings. -@item Ada.Strings.Fixed.Equal_Case_Insensitive (A.4.10) +@item @code{Ada.Strings.Fixed.Equal_Case_Insensitive} @emph{(A.4.10)} + This package provides an equality function for fixed strings that compares the strings after converting both to lower case. -@item Ada.Strings.Fixed.Hash_Case_Insensitive (A.4.9) +@item @code{Ada.Strings.Fixed.Hash_Case_Insensitive} @emph{(A.4.9)} + This package provides a case insensitive hash function for fixed strings that converts the string to lower case before computing the hash. -@item Ada.Strings.Fixed.Less_Case_Insensitive (A.4.10) +@item @code{Ada.Strings.Fixed.Less_Case_Insensitive} @emph{(A.4.10)} + This package provides a comparison function for fixed strings that works in a case insensitive manner by converting to lower case before the comparison. -Ada.Strings.Hash (A.4.9) +@item @code{Ada.Strings.Hash} @emph{(A.4.9)} + This package provides a hash function for strings. -Ada.Strings.Hash_Case_Insensitive (A.4.9) +@item @code{Ada.Strings.Hash_Case_Insensitive} @emph{(A.4.9)} + This package provides a hash function for strings that is case insensitive. The string is converted to lower case before computing the hash. -@item Ada.Strings.Less_Case_Insensitive (A.4.10) +@item @code{Ada.Strings.Less_Case_Insensitive} @emph{(A.4.10)} + This package provides a comparison function for\strings that works in a case insensitive manner by converting to lower case before the comparison. -@item Ada.Strings.Maps (A.4.2) +@item @code{Ada.Strings.Maps} @emph{(A.4.2)} + This package provides facilities for handling character mappings and arbitrarily defined subsets of characters. For instance it is useful in defining specialized translation tables. -@item Ada.Strings.Maps.Constants (A.4.6) +@item @code{Ada.Strings.Maps.Constants} @emph{(A.4.6)} + This package provides a standard set of predefined mappings and predefined character sets. For example, the standard upper to lower case conversion table is found in this package. Note that upper to lower case @@ -17498,85 +19883,124 @@ characters, including extended characters like E with an acute accent, into account. You should use the mappings in this package (rather than adding 32 yourself) to do case mappings. -@item Ada.Strings.Unbounded (A.4.5) +@item @code{Ada.Strings.Unbounded} @emph{(A.4.5)} + This package provides facilities for handling variable length strings. The unbounded model allows arbitrary length strings, but requires the use of dynamic allocation and finalization. -@item Ada.Strings.Unbounded.Equal_Case_Insensitive (A.4.10) +@item @code{Ada.Strings.Unbounded.Equal_Case_Insensitive} @emph{(A.4.10)} + Provides case-insensitive comparisons of unbounded strings -@item Ada.Strings.Unbounded.Hash (A.4.9) +@item @code{Ada.Strings.Unbounded.Hash} @emph{(A.4.9)} + This package provides a generic hash function for unbounded strings -@item Ada.Strings.Unbounded.Hash_Case_Insensitive (A.4.9) +@item @code{Ada.Strings.Unbounded.Hash_Case_Insensitive} @emph{(A.4.9)} + This package provides a generic hash function for unbounded strings that converts the string to be hashed to lower case. -@item Ada.Strings.Unbounded.Less_Case_Insensitive (A.4.10) +@item @code{Ada.Strings.Unbounded.Less_Case_Insensitive} @emph{(A.4.10)} + This package provides a comparison function for unbounded strings that works in a case insensitive manner by converting to lower case before the comparison. -@item Ada.Strings.UTF_Encoding (A.4.11) +@item @code{Ada.Strings.UTF_Encoding} @emph{(A.4.11)} + This package provides basic definitions for dealing with UTF-encoded strings. -@item Ada.Strings.UTF_Encoding.Conversions (A.4.11) +@item @code{Ada.Strings.UTF_Encoding.Conversions} @emph{(A.4.11)} + This package provides conversion functions for UTF-encoded strings. +@end table + +@code{Ada.Strings.UTF_Encoding.Strings} @emph{(A.4.11)} + +@code{Ada.Strings.UTF_Encoding.Wide_Strings} @emph{(A.4.11)} + + +@table @asis + +@item @code{Ada.Strings.UTF_Encoding.Wide_Wide_Strings} @emph{(A.4.11)} -@item Ada.Strings.UTF_Encoding.Strings (A.4.11) -@itemx Ada.Strings.UTF_Encoding.Wide_Strings (A.4.11) -@itemx Ada.Strings.UTF_Encoding.Wide_Wide_Strings (A.4.11) These packages provide facilities for handling UTF encodings for Strings, Wide_Strings and Wide_Wide_Strings. +@end table + +@code{Ada.Strings.Wide_Bounded} @emph{(A.4.7)} + +@code{Ada.Strings.Wide_Fixed} @emph{(A.4.7)} + +@code{Ada.Strings.Wide_Maps} @emph{(A.4.7)} + + +@table @asis + +@item @code{Ada.Strings.Wide_Unbounded} @emph{(A.4.7)} -@item Ada.Strings.Wide_Bounded (A.4.7) -@itemx Ada.Strings.Wide_Fixed (A.4.7) -@itemx Ada.Strings.Wide_Maps (A.4.7) -@itemx Ada.Strings.Wide_Unbounded (A.4.7) These packages provide analogous capabilities to the corresponding -packages without @samp{Wide_} in the name, but operate with the types -@code{Wide_String} and @code{Wide_Character} instead of @code{String} -and @code{Character}. Versions of all the child packages are available. - -@item Ada.Strings.Wide_Wide_Bounded (A.4.7) -@itemx Ada.Strings.Wide_Wide_Fixed (A.4.7) -@itemx Ada.Strings.Wide_Wide_Maps (A.4.7) -@itemx Ada.Strings.Wide_Wide_Unbounded (A.4.7) +packages without @code{Wide_} in the name, but operate with the types +@cite{Wide_String} and @cite{Wide_Character} instead of @cite{String} +and @cite{Character}. Versions of all the child packages are available. +@end table + +@code{Ada.Strings.Wide_Wide_Bounded} @emph{(A.4.7)} + +@code{Ada.Strings.Wide_Wide_Fixed} @emph{(A.4.7)} + +@code{Ada.Strings.Wide_Wide_Maps} @emph{(A.4.7)} + + +@table @asis + +@item @code{Ada.Strings.Wide_Wide_Unbounded} @emph{(A.4.7)} + These packages provide analogous capabilities to the corresponding -packages without @samp{Wide_} in the name, but operate with the types -@code{Wide_Wide_String} and @code{Wide_Wide_Character} instead -of @code{String} and @code{Character}. +packages without @code{Wide_} in the name, but operate with the types +@cite{Wide_Wide_String} and @cite{Wide_Wide_Character} instead +of @cite{String} and @cite{Character}. + +@item @code{Ada.Synchronous_Barriers} @emph{(D.10.1)} -@item Ada.Synchronous_Barriers (D.10.1) This package provides facilities for synchronizing tasks at a low level with barriers. -@item Ada.Synchronous_Task_Control (D.10) +@item @code{Ada.Synchronous_Task_Control} @emph{(D.10)} + This package provides some standard facilities for controlling task communication in a synchronous manner. -@item Ada.Synchronous_Task_Control.EDF (D.10) +@item @code{Ada.Synchronous_Task_Control.EDF} @emph{(D.10)} + Not implemented in GNAT. -@item Ada.Tags +@item @code{Ada.Tags} + This package contains definitions for manipulation of the tags of tagged values. -@item Ada.Tags.Generic_Dispatching_Constructor (3.9) +@item @code{Ada.Tags.Generic_Dispatching_Constructor} @emph{(3.9)} + This package provides a way of constructing tagged class-wide values given only the tag value. -@item Ada.Task_Attributes (C.7.2) +@item @code{Ada.Task_Attributes} @emph{(C.7.2)} + This package provides the capability of associating arbitrary task-specific data with separate tasks. -@item Ada.Task_Identifification (C.7.1) +@item @code{Ada.Task_Identifification} @emph{(C.7.1)} + This package provides capabilities for task identification. -@item Ada.Task_Termination (C.7.3) +@item @code{Ada.Task_Termination} @emph{(C.7.3)} + This package provides control over task termination. -@item Ada.Text_IO +@item @code{Ada.Text_IO} + This package provides basic text input-output capabilities for character, string and numeric data. The subpackages of this package are listed next. Note that although these are defined @@ -17584,69 +20008,107 @@ as subpackages in the RM, they are actually transparently implemented as child packages in GNAT, meaning that they are only loaded if needed. -@item Ada.Text_IO.Decimal_IO +@item @code{Ada.Text_IO.Decimal_IO} + Provides input-output facilities for decimal fixed-point types -@item Ada.Text_IO.Enumeration_IO +@item @code{Ada.Text_IO.Enumeration_IO} + Provides input-output facilities for enumeration types. -@item Ada.Text_IO.Fixed_IO +@item @code{Ada.Text_IO.Fixed_IO} + Provides input-output facilities for ordinary fixed-point types. -@item Ada.Text_IO.Float_IO +@item @code{Ada.Text_IO.Float_IO} + Provides input-output facilities for float types. The following predefined instantiations of this generic package are available: -@table @code -@item Short_Float -@code{Short_Float_Text_IO} -@item Float -@code{Float_Text_IO} -@item Long_Float -@code{Long_Float_Text_IO} -@end table -@item Ada.Text_IO.Integer_IO +@itemize * + +@item +@code{Short_Float} + +@cite{Short_Float_Text_IO} + +@item +@code{Float} + +@cite{Float_Text_IO} + +@item +@code{Long_Float} + +@cite{Long_Float_Text_IO} +@end itemize + +@item @code{Ada.Text_IO.Integer_IO} + Provides input-output facilities for integer types. The following predefined instantiations of this generic package are available: -@table @code -@item Short_Short_Integer -@code{Ada.Short_Short_Integer_Text_IO} -@item Short_Integer -@code{Ada.Short_Integer_Text_IO} -@item Integer -@code{Ada.Integer_Text_IO} -@item Long_Integer -@code{Ada.Long_Integer_Text_IO} -@item Long_Long_Integer -@code{Ada.Long_Long_Integer_Text_IO} -@end table -@item Ada.Text_IO.Modular_IO +@itemize * + +@item +@code{Short_Short_Integer} + +@cite{Ada.Short_Short_Integer_Text_IO} + +@item +@code{Short_Integer} + +@cite{Ada.Short_Integer_Text_IO} + +@item +@code{Integer} + +@cite{Ada.Integer_Text_IO} + +@item +@code{Long_Integer} + +@cite{Ada.Long_Integer_Text_IO} + +@item +@code{Long_Long_Integer} + +@cite{Ada.Long_Long_Integer_Text_IO} +@end itemize + +@item @code{Ada.Text_IO.Modular_IO} + Provides input-output facilities for modular (unsigned) types. -@item Ada.Text_IO.Bounded_IO (A.10.11) +@item @code{Ada.Text_IO.Bounded_IO (A.10.11)} + Provides input-output facilities for bounded strings. -@item Ada.Text_IO.Complex_IO (G.1.3) +@item @code{Ada.Text_IO.Complex_IO (G.1.3)} + This package provides basic text input-output capabilities for complex data. -@item Ada.Text_IO.Editing (F.3.3) +@item @code{Ada.Text_IO.Editing (F.3.3)} + This package contains routines for edited output, analogous to the use -of pictures in COBOL@. The picture formats used by this package are a -close copy of the facility in COBOL@. +of pictures in COBOL. The picture formats used by this package are a +close copy of the facility in COBOL. + +@item @code{Ada.Text_IO.Text_Streams (A.12.2)} -@item Ada.Text_IO.Text_Streams (A.12.2) This package provides a facility that allows Text_IO files to be treated as streams, so that the stream attributes can be used for writing arbitrary data, including binary data, to Text_IO files. -@item Ada.Text_IO.Unbounded_IO (A.10.12) +@item @code{Ada.Text_IO.Unbounded_IO (A.10.12)} + This package provides input-output facilities for unbounded strings. -@item Ada.Unchecked_Conversion (13.9) +@item @code{Ada.Unchecked_Conversion (13.9)} + This generic package allows arbitrary conversion from one type to another of the same size, providing for breaking the type safety in special circumstances. @@ -17697,33 +20159,36 @@ unchecked conversion nor Ada.Address_To_Access_Conversions should be used in conjunction with pointers to unconstrained objects, since the bounds information cannot be handled correctly in this case. -@item Ada.Unchecked_Deallocation (13.11.2) +@item @code{Ada.Unchecked_Deallocation} @emph{(13.11.2)} + This generic package allows explicit freeing of storage previously allocated by use of an allocator. -@item Ada.Wide_Text_IO (A.11) -This package is similar to @code{Ada.Text_IO}, except that the external +@item @code{Ada.Wide_Text_IO} @emph{(A.11)} + +This package is similar to @cite{Ada.Text_IO}, except that the external file supports wide character representations, and the internal types are -@code{Wide_Character} and @code{Wide_String} instead of @code{Character} -and @code{String}. The corresponding set of nested packages and child +@cite{Wide_Character} and @cite{Wide_String} instead of @cite{Character} +and @cite{String}. The corresponding set of nested packages and child packages are defined. -@item Ada.Wide_Wide_Text_IO (A.11) -This package is similar to @code{Ada.Text_IO}, except that the external +@item @code{Ada.Wide_Wide_Text_IO} @emph{(A.11)} + +This package is similar to @cite{Ada.Text_IO}, except that the external file supports wide character representations, and the internal types are -@code{Wide_Character} and @code{Wide_String} instead of @code{Character} -and @code{String}. The corresponding set of nested packages and child +@cite{Wide_Character} and @cite{Wide_String} instead of @cite{Character} +and @cite{String}. The corresponding set of nested packages and child packages are defined. - @end table For packages in Interfaces and System, all the RM defined packages are available in GNAT, see the Ada 2012 RM for full details. -@node The Implementation of Standard I/O +@node The Implementation of Standard I/O,The GNAT Library,Standard Library Routines,Top +@anchor{gnat_rm/the_implementation_of_standard_i_o the-implementation-of-standard-i-o}@anchor{f}@anchor{gnat_rm/the_implementation_of_standard_i_o doc}@anchor{240}@anchor{gnat_rm/the_implementation_of_standard_i_o id1}@anchor{241} @chapter The Implementation of Standard I/O -@noindent + GNAT implements all the required input-output facilities described in A.6 through A.14. These sections of the Ada Reference Manual describe the required behavior of these packages from the Ada point of view, and if @@ -17753,148 +20218,146 @@ of additional child library packages, that facilitate this sharing, and these additional facilities are also described in this chapter. @menu -* Standard I/O Packages:: -* FORM Strings:: -* Direct_IO:: -* Sequential_IO:: -* Text_IO:: -* Wide_Text_IO:: -* Wide_Wide_Text_IO:: -* Stream_IO:: -* Text Translation:: -* Shared Files:: -* Filenames encoding:: -* File content encoding:: -* Open Modes:: -* Operations on C Streams:: -* Interfacing to C Streams:: +* Standard I/O Packages:: +* FORM Strings:: +* Direct_IO:: +* Sequential_IO:: +* Text_IO:: +* Wide_Text_IO:: +* Wide_Wide_Text_IO:: +* Stream_IO:: +* Text Translation:: +* Shared Files:: +* Filenames encoding:: +* File content encoding:: +* Open Modes:: +* Operations on C Streams:: +* Interfacing to C Streams:: + @end menu -@node Standard I/O Packages +@node Standard I/O Packages,FORM Strings,,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o standard-i-o-packages}@anchor{242}@anchor{gnat_rm/the_implementation_of_standard_i_o id2}@anchor{243} @section Standard I/O Packages -@noindent + The Standard I/O packages described in Annex A for -@itemize @bullet -@item + +@itemize * + +@item Ada.Text_IO -@item + +@item Ada.Text_IO.Complex_IO -@item + +@item Ada.Text_IO.Text_Streams -@item + +@item Ada.Wide_Text_IO -@item + +@item Ada.Wide_Text_IO.Complex_IO -@item + +@item Ada.Wide_Text_IO.Text_Streams -@item + +@item Ada.Wide_Wide_Text_IO -@item + +@item Ada.Wide_Wide_Text_IO.Complex_IO -@item + +@item Ada.Wide_Wide_Text_IO.Text_Streams -@item + +@item Ada.Stream_IO -@item + +@item Ada.Sequential_IO -@item + +@item Ada.Direct_IO @end itemize -@noindent are implemented using the C library streams facility; where -@itemize @bullet -@item -All files are opened using @code{fopen}. -@item -All input/output operations use @code{fread}/@code{fwrite}. + +@itemize * + +@item +All files are opened using @cite{fopen}. + +@item +All input/output operations use @cite{fread}/@cite{fwrite}. @end itemize -@noindent There is no internal buffering of any kind at the Ada library level. The only buffering is that provided at the system level in the implementation of the library routines that support streams. This facilitates shared use of these streams by mixed language programs. Note though that system level buffering is explicitly enabled at elaboration of the standard I/O packages and that can have an impact on mixed language programs, in particular those using I/O before -calling the Ada elaboration routine (e.g.@: adainit). It is recommended to call +calling the Ada elaboration routine (e.g., adainit). It is recommended to call the Ada elaboration routine before performing any I/O or when impractical, flush the common I/O streams and in particular Standard_Output before elaborating the Ada code. -@node FORM Strings +@node FORM Strings,Direct_IO,Standard I/O Packages,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o form-strings}@anchor{244}@anchor{gnat_rm/the_implementation_of_standard_i_o id3}@anchor{245} @section FORM Strings -@noindent + The format of a FORM string in GNAT is: -@smallexample -"keyword=value,keyword=value,@dots{},keyword=value" -@end smallexample +@example +"keyword=value,keyword=value,...,keyword=value" +@end example -@noindent where letters may be in upper or lower case, and there are no spaces between values. The order of the entries is not important. Currently the following keywords defined. -@smallexample +@example TEXT_TRANSLATION=[YES|NO|TEXT|BINARY|U8TEXT|WTEXT|U16TEXT] SHARED=[YES|NO] WCEM=[n|h|u|s|e|8|b] ENCODING=[UTF8|8BITS] -@end smallexample +@end example -@noindent The use of these parameters is described later in this section. If an unrecognized keyword appears in a form string, it is silently ignored and not considered invalid. -@noindent -For OpenVMS additional FORM string keywords are available for use with -RMS services. The syntax is: - -@smallexample -VMS_RMS_Keys=(keyword=value,@dots{},keyword=value) -@end smallexample - -@noindent -The following RMS keywords and values are currently defined: - -@smallexample -Context=Force_Stream_Mode|Force_Record_Mode -@end smallexample - -@noindent -VMS RMS keys are silently ignored on non-VMS systems. On OpenVMS -unimplented RMS keywords, values, or invalid syntax will raise Use_Error. - -@node Direct_IO +@node Direct_IO,Sequential_IO,FORM Strings,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o direct-io}@anchor{246}@anchor{gnat_rm/the_implementation_of_standard_i_o id4}@anchor{247} @section Direct_IO -@noindent + Direct_IO can only be instantiated for definite types. This is a restriction of the Ada language, which means that the records are fixed -length (the length being determined by @code{@var{type}'Size}, rounded +length (the length being determined by @code{type'Size}, rounded up to the next storage unit boundary if necessary). The records of a Direct_IO file are simply written to the file in index sequence, with the first record starting at offset zero, and subsequent records following. There is no control information of any kind. For example, if 32-bit integers are being written, each record takes -4-bytes, so the record at index @var{K} starts at offset -(@var{K}@minus{}1)*4. +4-bytes, so the record at index @cite{K} starts at offset +(@cite{K}-1)*4. There is no limit on the size of Direct_IO files, they are expanded as necessary to accommodate whatever records are written to the file. -@node Sequential_IO +@node Sequential_IO,Text_IO,Direct_IO,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o sequential-io}@anchor{248}@anchor{gnat_rm/the_implementation_of_standard_i_o id5}@anchor{249} @section Sequential_IO -@noindent + Sequential_IO may be instantiated with either a definite (constrained) or indefinite (unconstrained) type. @@ -17905,139 +20368,143 @@ checking is performed on input. For the indefinite type case, the elements written consist of two parts. First is the size of the data item, written as the memory image -of a @code{Interfaces.C.size_t} value, followed by the memory image of +of a @cite{Interfaces.C.size_t} value, followed by the memory image of the data value. The resulting file can only be read using the same (unconstrained) type. Normal assignment checks are performed on these -read operations, and if these checks fail, @code{Data_Error} is +read operations, and if these checks fail, @cite{Data_Error} is raised. In particular, in the array case, the lengths must match, and in the variant record case, if the variable for a particular read operation is constrained, the discriminants must match. Note that it is not possible to use Sequential_IO to write variable length array items, and then read the data back into different length -arrays. For example, the following will raise @code{Data_Error}: - -@smallexample @c ada - package IO is new Sequential_IO (String); - F : IO.File_Type; - S : String (1..4); - @dots{} - IO.Create (F) - IO.Write (F, "hello!") - IO.Reset (F, Mode=>In_File); - IO.Read (F, S); - Put_Line (S); - -@end smallexample - -@noindent -On some Ada implementations, this will print @code{hell}, but the program is +arrays. For example, the following will raise @cite{Data_Error}: + +@example +package IO is new Sequential_IO (String); +F : IO.File_Type; +S : String (1..4); +... +IO.Create (F) +IO.Write (F, "hello!") +IO.Reset (F, Mode=>In_File); +IO.Read (F, S); +Put_Line (S); +@end example + +On some Ada implementations, this will print @cite{hell}, but the program is clearly incorrect, since there is only one element in the file, and that -element is the string @code{hello!}. +element is the string @cite{hello!}. In Ada 95 and Ada 2005, this kind of behavior can be legitimately achieved using Stream_IO, and this is the preferred mechanism. In particular, the above program fragment rewritten to use Stream_IO will work correctly. -@node Text_IO +@node Text_IO,Wide_Text_IO,Sequential_IO,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o id6}@anchor{24a}@anchor{gnat_rm/the_implementation_of_standard_i_o text-io}@anchor{24b} @section Text_IO -@noindent + Text_IO files consist of a stream of characters containing the following special control characters: -@smallexample +@example LF (line feed, 16#0A#) Line Mark FF (form feed, 16#0C#) Page Mark -@end smallexample +@end example -@noindent A canonical Text_IO file is defined as one in which the following conditions are met: -@itemize @bullet -@item -The character @code{LF} is used only as a line mark, i.e.@: to mark the end + +@itemize * + +@item +The character @cite{LF} is used only as a line mark, i.e., to mark the end of the line. -@item -The character @code{FF} is used only as a page mark, i.e.@: to mark the +@item +The character @cite{FF} is used only as a page mark, i.e., to mark the end of a page and consequently can appear only immediately following a -@code{LF} (line mark) character. +@cite{LF} (line mark) character. -@item -The file ends with either @code{LF} (line mark) or @code{LF}-@code{FF} +@item +The file ends with either @cite{LF} (line mark) or @cite{LF}-@cite{FF} (line mark, page mark). In the former case, the page mark is implicitly assumed to be present. @end itemize -@noindent A file written using Text_IO will be in canonical form provided that no -explicit @code{LF} or @code{FF} characters are written using @code{Put} -or @code{Put_Line}. There will be no @code{FF} character at the end of -the file unless an explicit @code{New_Page} operation was performed +explicit @cite{LF} or @cite{FF} characters are written using @cite{Put} +or @cite{Put_Line}. There will be no @cite{FF} character at the end of +the file unless an explicit @cite{New_Page} operation was performed before closing the file. A canonical Text_IO file that is a regular file (i.e., not a device or a -pipe) can be read using any of the routines in Text_IO@. The +pipe) can be read using any of the routines in Text_IO. The semantics in this case will be exactly as defined in the Ada Reference Manual, and all the routines in Text_IO are fully implemented. A text file that does not meet the requirements for a canonical Text_IO file has one of the following: -@itemize @bullet -@item -The file contains @code{FF} characters not immediately following a -@code{LF} character. -@item -The file contains @code{LF} or @code{FF} characters written by -@code{Put} or @code{Put_Line}, which are not logically considered to be +@itemize * + +@item +The file contains @cite{FF} characters not immediately following a +@cite{LF} character. + +@item +The file contains @cite{LF} or @cite{FF} characters written by +@cite{Put} or @cite{Put_Line}, which are not logically considered to be line marks or page marks. -@item -The file ends in a character other than @code{LF} or @code{FF}, -i.e.@: there is no explicit line mark or page mark at the end of the file. +@item +The file ends in a character other than @cite{LF} or @cite{FF}, +i.e., there is no explicit line mark or page mark at the end of the file. @end itemize -@noindent Text_IO can be used to read such non-standard text files but subprograms to do with line or page numbers do not have defined meanings. In -particular, a @code{FF} character that does not follow a @code{LF} +particular, a @cite{FF} character that does not follow a @cite{LF} character may or may not be treated as a page mark from the point of -view of page and line numbering. Every @code{LF} character is considered -to end a line, and there is an implied @code{LF} character at the end of +view of page and line numbering. Every @cite{LF} character is considered +to end a line, and there is an implied @cite{LF} character at the end of the file. @menu -* Text_IO Stream Pointer Positioning:: -* Text_IO Reading and Writing Non-Regular Files:: -* Get_Immediate:: -* Treating Text_IO Files as Streams:: -* Text_IO Extensions:: -* Text_IO Facilities for Unbounded Strings:: +* Stream Pointer Positioning:: +* Reading and Writing Non-Regular Files:: +* Get_Immediate:: +* Treating Text_IO Files as Streams:: +* Text_IO Extensions:: +* Text_IO Facilities for Unbounded Strings:: + @end menu -@node Text_IO Stream Pointer Positioning +@node Stream Pointer Positioning,Reading and Writing Non-Regular Files,,Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o id7}@anchor{24c}@anchor{gnat_rm/the_implementation_of_standard_i_o stream-pointer-positioning}@anchor{24d} @subsection Stream Pointer Positioning -@noindent -@code{Ada.Text_IO} has a definition of current position for a file that + +@cite{Ada.Text_IO} has a definition of current position for a file that is being read. No internal buffering occurs in Text_IO, and usually the physical position in the stream used to implement the file corresponds -to this logical position defined by Text_IO@. There are two exceptions: +to this logical position defined by Text_IO. There are two exceptions: -@itemize @bullet -@item -After a call to @code{End_Of_Page} that returns @code{True}, the stream -is positioned past the @code{LF} (line mark) that precedes the page + +@itemize * + +@item +After a call to @cite{End_Of_Page} that returns @cite{True}, the stream +is positioned past the @cite{LF} (line mark) that precedes the page mark. Text_IO maintains an internal flag so that subsequent read operations properly handle the logical position which is unchanged by -the @code{End_Of_Page} call. +the @cite{End_Of_Page} call. -@item -After a call to @code{End_Of_File} that returns @code{True}, if the +@item +After a call to @cite{End_Of_File} that returns @cite{True}, if the Text_IO file was positioned before the line mark at the end of file before the call, then the logical position is unchanged, but the stream is physically positioned right at the end of file (past the line mark, @@ -18046,17 +20513,17 @@ maintains internal flags so that subsequent read operations properly handle the logical position. @end itemize -@noindent These discrepancies have no effect on the observable behavior of Text_IO, but if a single Ada stream is shared between a C program and -Ada program, or shared (using @samp{shared=yes} in the form string) +Ada program, or shared (using @code{shared=yes} in the form string) between two Ada files, then the difference may be observable in some situations. -@node Text_IO Reading and Writing Non-Regular Files +@node Reading and Writing Non-Regular Files,Get_Immediate,Stream Pointer Positioning,Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o reading-and-writing-non-regular-files}@anchor{24e}@anchor{gnat_rm/the_implementation_of_standard_i_o id8}@anchor{24f} @subsection Reading and Writing Non-Regular Files -@noindent + A non-regular file is a device (such as a keyboard), or a pipe. Text_IO can be used for reading and writing. Writing is not affected and the sequence of characters output is identical to the normal file case, but @@ -18064,49 +20531,52 @@ for reading, the behavior of Text_IO is modified to avoid undesirable look-ahead as follows: An input file that is not a regular file is considered to have no page -marks. Any @code{Ascii.FF} characters (the character normally used for a +marks. Any @cite{Ascii.FF} characters (the character normally used for a page mark) appearing in the file are considered to be data characters. In particular: -@itemize @bullet -@item -@code{Get_Line} and @code{Skip_Line} do not test for a page mark + +@itemize * + +@item +@cite{Get_Line} and @cite{Skip_Line} do not test for a page mark following a line mark. If a page mark appears, it will be treated as a data character. -@item +@item This avoids the need to wait for an extra character to be typed or entered from the pipe to complete one of these operations. -@item -@code{End_Of_Page} always returns @code{False} +@item +@cite{End_Of_Page} always returns @cite{False} -@item -@code{End_Of_File} will return @code{False} if there is a page mark at +@item +@cite{End_Of_File} will return @cite{False} if there is a page mark at the end of the file. @end itemize -@noindent Output to non-regular files is the same as for regular files. Page marks -may be written to non-regular files using @code{New_Page}, but as noted +may be written to non-regular files using @cite{New_Page}, but as noted above they will not be treated as page marks on input if the output is piped to another Ada program. Another important discrepancy when reading non-regular files is that the end -of file indication is not ``sticky''. If an end of file is entered, e.g.@: by -pressing the @key{EOT} key, +of file indication is not 'sticky'. If an end of file is entered, e.g., by +pressing the @code{EOT} key, then end of file -is signaled once (i.e.@: the test @code{End_Of_File} -will yield @code{True}, or a read will -raise @code{End_Error}), but then reading can resume +is signaled once (i.e., the test @cite{End_Of_File} +will yield @cite{True}, or a read will +raise @cite{End_Error}), but then reading can resume to read data past that end of file indication, until another end of file indication is entered. -@node Get_Immediate +@node Get_Immediate,Treating Text_IO Files as Streams,Reading and Writing Non-Regular Files,Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o get-immediate}@anchor{250}@anchor{gnat_rm/the_implementation_of_standard_i_o id9}@anchor{251} @subsection Get_Immediate -@cindex Get_Immediate -@noindent + +@geindex Get_Immediate + Get_Immediate returns the next character (including control characters) from the input file. In particular, Get_Immediate will return LF or FF characters used as line marks or page marks. Such operations leave the @@ -18118,116 +20588,176 @@ positioned between the line mark and page mark (which is not normally possible), it is undefined whether the FF character will be treated as a page mark. -@node Treating Text_IO Files as Streams +@node Treating Text_IO Files as Streams,Text_IO Extensions,Get_Immediate,Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o id10}@anchor{252}@anchor{gnat_rm/the_implementation_of_standard_i_o treating-text-io-files-as-streams}@anchor{253} @subsection Treating Text_IO Files as Streams -@cindex Stream files -@noindent -The package @code{Text_IO.Streams} allows a Text_IO file to be treated + +@geindex Stream files + +The package @cite{Text_IO.Streams} allows a Text_IO file to be treated as a stream. Data written to a Text_IO file in this stream mode is -binary data. If this binary data contains bytes 16#0A# (@code{LF}) or -16#0C# (@code{FF}), the resulting file may have non-standard +binary data. If this binary data contains bytes 16#0A# (@cite{LF}) or +16#0C# (@cite{FF}), the resulting file may have non-standard format. Similarly if read operations are used to read from a Text_IO -file treated as a stream, then @code{LF} and @code{FF} characters may be +file treated as a stream, then @cite{LF} and @cite{FF} characters may be skipped and the effect is similar to that described above for -@code{Get_Immediate}. +@cite{Get_Immediate}. -@node Text_IO Extensions +@node Text_IO Extensions,Text_IO Facilities for Unbounded Strings,Treating Text_IO Files as Streams,Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o id11}@anchor{254}@anchor{gnat_rm/the_implementation_of_standard_i_o text-io-extensions}@anchor{255} @subsection Text_IO Extensions -@cindex Text_IO extensions -@noindent + +@geindex Text_IO extensions + A package GNAT.IO_Aux in the GNAT library provides some useful extensions -to the standard @code{Text_IO} package: +to the standard @cite{Text_IO} package: -@itemize @bullet -@item function File_Exists (Name : String) return Boolean; + +@itemize * + +@item +function File_Exists (Name : String) return Boolean; Determines if a file of the given name exists. -@item function Get_Line return String; +@item +function Get_Line return String; Reads a string from the standard input file. The value returned is exactly the length of the line that was read. -@item function Get_Line (File : Ada.Text_IO.File_Type) return String; +@item +function Get_Line (File : Ada.Text_IO.File_Type) return String; Similar, except that the parameter File specifies the file from which the string is to be read. - @end itemize -@node Text_IO Facilities for Unbounded Strings +@node Text_IO Facilities for Unbounded Strings,,Text_IO Extensions,Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o text-io-facilities-for-unbounded-strings}@anchor{256}@anchor{gnat_rm/the_implementation_of_standard_i_o id12}@anchor{257} @subsection Text_IO Facilities for Unbounded Strings -@cindex Text_IO for unbounded strings -@cindex Unbounded_String, Text_IO operations -@noindent -The package @code{Ada.Strings.Unbounded.Text_IO} -in library files @code{a-suteio.ads/adb} contains some GNAT-specific + +@geindex Text_IO for unbounded strings + +@geindex Unbounded_String +@geindex Text_IO operations + +The package @cite{Ada.Strings.Unbounded.Text_IO} +in library files @cite{a-suteio.ads/adb} contains some GNAT-specific subprograms useful for Text_IO operations on unbounded strings: -@itemize @bullet -@item function Get_Line (File : File_Type) return Unbounded_String; +@itemize * + +@item +function Get_Line (File : File_Type) return Unbounded_String; Reads a line from the specified file and returns the result as an unbounded string. -@item procedure Put (File : File_Type; U : Unbounded_String); +@item +procedure Put (File : File_Type; U : Unbounded_String); Writes the value of the given unbounded string to the specified file Similar to the effect of -@code{Put (To_String (U))} except that an extra copy is avoided. +@cite{Put (To_String (U))} except that an extra copy is avoided. -@item procedure Put_Line (File : File_Type; U : Unbounded_String); +@item +procedure Put_Line (File : File_Type; U : Unbounded_String); Writes the value of the given unbounded string to the specified file, -followed by a @code{New_Line}. -Similar to the effect of @code{Put_Line (To_String (U))} except +followed by a @cite{New_Line}. +Similar to the effect of @cite{Put_Line (To_String (U))} except that an extra copy is avoided. @end itemize -@noindent -In the above procedures, @code{File} is of type @code{Ada.Text_IO.File_Type} +In the above procedures, @cite{File} is of type @cite{Ada.Text_IO.File_Type} and is optional. If the parameter is omitted, then the standard input or output file is referenced as appropriate. -The package @code{Ada.Strings.Wide_Unbounded.Wide_Text_IO} in library -files @file{a-swuwti.ads} and @file{a-swuwti.adb} provides similar extended -@code{Wide_Text_IO} functionality for unbounded wide strings. +The package @cite{Ada.Strings.Wide_Unbounded.Wide_Text_IO} in library +files @code{a-swuwti.ads} and @code{a-swuwti.adb} provides similar extended +@cite{Wide_Text_IO} functionality for unbounded wide strings. -The package @code{Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO} in library -files @file{a-szuzti.ads} and @file{a-szuzti.adb} provides similar extended -@code{Wide_Wide_Text_IO} functionality for unbounded wide wide strings. +The package @cite{Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO} in library +files @code{a-szuzti.ads} and @code{a-szuzti.adb} provides similar extended +@cite{Wide_Wide_Text_IO} functionality for unbounded wide wide strings. -@node Wide_Text_IO +@node Wide_Text_IO,Wide_Wide_Text_IO,Text_IO,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o wide-text-io}@anchor{258}@anchor{gnat_rm/the_implementation_of_standard_i_o id13}@anchor{259} @section Wide_Text_IO -@noindent -@code{Wide_Text_IO} is similar in most respects to Text_IO, except that + +@cite{Wide_Text_IO} is similar in most respects to Text_IO, except that both input and output files may contain special sequences that represent wide character values. The encoding scheme for a given file may be specified using a FORM parameter: -@smallexample -WCEM=@var{x} -@end smallexample +@example +WCEM=`x` +@end example -@noindent as part of the FORM string (WCEM = wide character encoding method), -where @var{x} is one of the following characters +where @cite{x} is one of the following characters + + +@multitable {xxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxxx} +@headitem + +Character + +@tab + +Encoding + +@item + +@emph{h} + +@tab -@table @samp -@item h Hex ESC encoding -@item u + +@item + +@emph{u} + +@tab + Upper half encoding -@item s + +@item + +@emph{s} + +@tab + Shift-JIS encoding -@item e + +@item + +@emph{e} + +@tab + EUC Encoding -@item 8 + +@item + +@emph{8} + +@tab + UTF-8 encoding -@item b + +@item + +@emph{b} + +@tab + Brackets encoding -@end table -@noindent +@end multitable + + The encoding methods match those that can be used in a source program, but there is no requirement that the encoding method used for @@ -18239,30 +20769,42 @@ for which no WCEM parameter is given in the FORM string matches the wide character encoding specified for the main program (the default being brackets encoding if no coding method was specified with -gnatW). + @table @asis -@item Hex Coding + +@item @emph{Hex Coding} + In this encoding, a wide character is represented by a five character sequence: +@end table -@smallexample +@example ESC a b c d -@end smallexample +@end example + -@noindent -where @var{a}, @var{b}, @var{c}, @var{d} are the four hexadecimal +@quotation + +where @cite{a}, @cite{b}, @cite{c}, @cite{d} are the four hexadecimal characters (using upper case letters) of the wide character code. For example, ESC A345 is used to represent the wide character with code 16#A345#. This scheme is compatible with use of the full -@code{Wide_Character} set. +@cite{Wide_Character} set. +@end quotation + + +@table @asis + +@item @emph{Upper Half Coding} -@item Upper Half Coding The wide character with encoding 16#abcd#, where the upper bit is on -(i.e.@: a is in the range 8-F) is represented as two bytes 16#ab# and +(i.e., a is in the range 8-F) is represented as two bytes 16#ab# and 16#cd#. The second byte may never be a format control character, but is not required to be in the upper half. This method can be also used for shift-JIS or EUC where the internal coding matches the external coding. -@item Shift JIS Coding +@item @emph{Shift JIS Coding} + A wide character is represented by a two character sequence 16#ab# and 16#cd#, with the restrictions described for upper half encoding as described above. The internal character code is the corresponding JIS @@ -18270,27 +20812,32 @@ character according to the standard algorithm for Shift-JIS conversion. Only characters defined in the JIS code set table can be used with this encoding method. -@item EUC Coding +@item @emph{EUC Coding} + A wide character is represented by a two character sequence 16#ab# and 16#cd#, with both characters being in the upper half. The internal character code is the corresponding JIS character according to the EUC encoding algorithm. Only characters defined in the JIS code set table can be used with this encoding method. -@item UTF-8 Coding +@item @emph{UTF-8 Coding} + A wide character is represented using UCS Transformation Format 8 (UTF-8) as defined in Annex R of ISO 10646-1/Am.2. Depending on the character value, the representation is a one, two, or three byte sequence: +@end table -@smallexample +@example 16#0000#-16#007f#: 2#0xxxxxxx# 16#0080#-16#07ff#: 2#110xxxxx# 2#10xxxxxx# 16#0800#-16#ffff#: 2#1110xxxx# 2#10xxxxxx# 2#10xxxxxx# -@end smallexample +@end example + -@noindent -where the @var{xxx} bits correspond to the left-padded bits of the +@quotation + +where the @cite{xxx} bits correspond to the left-padded bits of the 16-bit character value. Note that all lower half ASCII characters are represented as ASCII bytes and all upper half characters and other wide characters are represented as sequences of upper-half @@ -18298,24 +20845,32 @@ other wide characters are represented as sequences of upper-half 6-byte sequences, but in this implementation, all UTF-8 sequences of four or more bytes length will raise a Constraint_Error, as will all invalid UTF-8 sequences.) +@end quotation + + +@table @asis + +@item @emph{Brackets Coding} -@item Brackets Coding In this encoding, a wide character is represented by the following eight character sequence: +@end table -@smallexample +@example [ " a b c d " ] -@end smallexample +@end example + + +@quotation -@noindent -where @code{a}, @code{b}, @code{c}, @code{d} are the four hexadecimal +where @cite{a}, @cite{b}, @cite{c}, @cite{d} are the four hexadecimal characters (using uppercase letters) of the wide character code. For -example, @code{["A345"]} is used to represent the wide character with code -@code{16#A345#}. +example, @cite{["A345"]} is used to represent the wide character with code +@cite{16#A345#}. This scheme is compatible with use of the full Wide_Character set. On input, brackets coding can also be used for upper half characters, -e.g.@: @code{["C1"]} for lower case a. However, on output, brackets notation -is only used for wide characters with a code greater than @code{16#FF#}. +e.g., @cite{["C1"]} for lower case a. However, on output, brackets notation +is only used for wide characters with a code greater than @cite{16#FF#}. Note that brackets coding is not normally used in the context of Wide_Text_IO or Wide_Wide_Text_IO, since it is really just designed as @@ -18337,28 +20892,28 @@ and not as ["5B"]. We make this decision because for normal use of Wide_Text_IO for outputting messages, it is unpleasant to clobber left brackets. For example, if we write: -@smallexample - Put_Line ("Start of output [first run]"); -@end smallexample +@example +Put_Line ("Start of output [first run]"); +@end example -@noindent we really do not want to have the left bracket in this message clobbered so that the output reads: +@end quotation + +@example +Start of output ["5B"]first run] +@end example + -@smallexample - Start of output ["5B"]first run] -@end smallexample +@quotation -@noindent In practice brackets encoding is reasonably useful for normal Put_Line use since we won't get confused between left brackets and wide character sequences in the output. But for input, or when files are written out and read back in, it really makes better sense to use one of the standard encoding methods such as UTF-8. +@end quotation -@end table - -@noindent For the coding schemes other than UTF-8, Hex, or Brackets encoding, not all wide character values can be represented. An attempt to output a character that cannot @@ -18367,77 +20922,124 @@ Constraint_Error to be raised. An invalid wide character sequence on input also causes Constraint_Error to be raised. @menu -* Wide_Text_IO Stream Pointer Positioning:: -* Wide_Text_IO Reading and Writing Non-Regular Files:: +* Stream Pointer Positioning: Stream Pointer Positioning<2>. +* Reading and Writing Non-Regular Files: Reading and Writing Non-Regular Files<2>. + @end menu -@node Wide_Text_IO Stream Pointer Positioning +@node Stream Pointer Positioning<2>,Reading and Writing Non-Regular Files<2>,,Wide_Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o stream-pointer-positioning-1}@anchor{25a}@anchor{gnat_rm/the_implementation_of_standard_i_o id14}@anchor{25b} @subsection Stream Pointer Positioning -@noindent -@code{Ada.Wide_Text_IO} is similar to @code{Ada.Text_IO} in its handling -of stream pointer positioning (@pxref{Text_IO}). There is one additional + +@cite{Ada.Wide_Text_IO} is similar to @cite{Ada.Text_IO} in its handling +of stream pointer positioning (@ref{24b,,Text_IO}). There is one additional case: -If @code{Ada.Wide_Text_IO.Look_Ahead} reads a character outside the -normal lower ASCII set (i.e.@: a character in the range: +If @cite{Ada.Wide_Text_IO.Look_Ahead} reads a character outside the +normal lower ASCII set (i.e., a character in the range: -@smallexample @c ada +@example Wide_Character'Val (16#0080#) .. Wide_Character'Val (16#FFFF#) -@end smallexample +@end example -@noindent then although the logical position of the file pointer is unchanged by -the @code{Look_Ahead} call, the stream is physically positioned past the +the @cite{Look_Ahead} call, the stream is physically positioned past the wide character sequence. Again this is to avoid the need for buffering -or backup, and all @code{Wide_Text_IO} routines check the internal +or backup, and all @cite{Wide_Text_IO} routines check the internal indication that this situation has occurred so that this is not visible -to a normal program using @code{Wide_Text_IO}. However, this discrepancy +to a normal program using @cite{Wide_Text_IO}. However, this discrepancy can be observed if the wide text file shares a stream with another file. -@node Wide_Text_IO Reading and Writing Non-Regular Files +@node Reading and Writing Non-Regular Files<2>,,Stream Pointer Positioning<2>,Wide_Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o reading-and-writing-non-regular-files-1}@anchor{25c}@anchor{gnat_rm/the_implementation_of_standard_i_o id15}@anchor{25d} @subsection Reading and Writing Non-Regular Files -@noindent + As in the case of Text_IO, when a non-regular file is read, it is assumed that the file contains no page marks (any form characters are -treated as data characters), and @code{End_Of_Page} always returns -@code{False}. Similarly, the end of file indication is not sticky, so +treated as data characters), and @cite{End_Of_Page} always returns +@cite{False}. Similarly, the end of file indication is not sticky, so it is possible to read beyond an end of file. -@node Wide_Wide_Text_IO +@node Wide_Wide_Text_IO,Stream_IO,Wide_Text_IO,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o id16}@anchor{25e}@anchor{gnat_rm/the_implementation_of_standard_i_o wide-wide-text-io}@anchor{25f} @section Wide_Wide_Text_IO -@noindent -@code{Wide_Wide_Text_IO} is similar in most respects to Text_IO, except that + +@cite{Wide_Wide_Text_IO} is similar in most respects to Text_IO, except that both input and output files may contain special sequences that represent wide wide character values. The encoding scheme for a given file may be specified using a FORM parameter: -@smallexample -WCEM=@var{x} -@end smallexample +@example +WCEM=`x` +@end example -@noindent as part of the FORM string (WCEM = wide character encoding method), -where @var{x} is one of the following characters +where @cite{x} is one of the following characters + + +@multitable {xxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxxx} +@headitem + +Character + +@tab + +Encoding + +@item + +@emph{h} + +@tab -@table @samp -@item h Hex ESC encoding -@item u + +@item + +@emph{u} + +@tab + Upper half encoding -@item s + +@item + +@emph{s} + +@tab + Shift-JIS encoding -@item e + +@item + +@emph{e} + +@tab + EUC Encoding -@item 8 + +@item + +@emph{8} + +@tab + UTF-8 encoding -@item b + +@item + +@emph{b} + +@tab + Brackets encoding -@end table -@noindent +@end multitable + + The encoding methods match those that can be used in a source program, but there is no requirement that the encoding method used for @@ -18449,57 +21051,72 @@ for which no WCEM parameter is given in the FORM string matches the wide character encoding specified for the main program (the default being brackets encoding if no coding method was specified with -gnatW). + @table @asis -@item UTF-8 Coding +@item @emph{UTF-8 Coding} + A wide character is represented using UCS Transformation Format 8 (UTF-8) as defined in Annex R of ISO 10646-1/Am.2. Depending on the character value, the representation is a one, two, three, or four byte sequence: +@end table -@smallexample +@example 16#000000#-16#00007f#: 2#0xxxxxxx# 16#000080#-16#0007ff#: 2#110xxxxx# 2#10xxxxxx# 16#000800#-16#00ffff#: 2#1110xxxx# 2#10xxxxxx# 2#10xxxxxx# 16#010000#-16#10ffff#: 2#11110xxx# 2#10xxxxxx# 2#10xxxxxx# 2#10xxxxxx# -@end smallexample +@end example + + +@quotation -@noindent -where the @var{xxx} bits correspond to the left-padded bits of the +where the @cite{xxx} bits correspond to the left-padded bits of the 21-bit character value. Note that all lower half ASCII characters are represented as ASCII bytes and all upper half characters and other wide characters are represented as sequences of upper-half characters. +@end quotation + + +@table @asis + +@item @emph{Brackets Coding} -@item Brackets Coding In this encoding, a wide wide character is represented by the following eight character sequence if is in wide character range +@end table -@smallexample +@example [ " a b c d " ] -@end smallexample +@end example + + +@quotation and by the following ten character sequence if not +@end quotation -@smallexample +@example [ " a b c d e f " ] -@end smallexample +@end example + + +@quotation -@noindent -where @code{a}, @code{b}, @code{c}, @code{d}, @code{e}, and @code{f} +where @cite{a}, @cite{b}, @cite{c}, @cite{d}, @cite{e}, and @cite{f} are the four or six hexadecimal characters (using uppercase letters) of the wide wide character code. For -example, @code{["01A345"]} is used to represent the wide wide character -with code @code{16#01A345#}. +example, @cite{["01A345"]} is used to represent the wide wide character +with code @cite{16#01A345#}. This scheme is compatible with use of the full Wide_Wide_Character set. On input, brackets coding can also be used for upper half characters, -e.g.@: @code{["C1"]} for lower case a. However, on output, brackets notation -is only used for wide characters with a code greater than @code{16#FF#}. - -@end table +e.g., @cite{["C1"]} for lower case a. However, on output, brackets notation +is only used for wide characters with a code greater than @cite{16#FF#}. +@end quotation -@noindent If is also possible to use the other Wide_Character encoding methods, such as Shift-JIS, but the other schemes cannot support the full range of wide wide characters. @@ -18509,102 +21126,107 @@ Constraint_Error to be raised. An invalid wide character sequence on input also causes Constraint_Error to be raised. @menu -* Wide_Wide_Text_IO Stream Pointer Positioning:: -* Wide_Wide_Text_IO Reading and Writing Non-Regular Files:: +* Stream Pointer Positioning: Stream Pointer Positioning<3>. +* Reading and Writing Non-Regular Files: Reading and Writing Non-Regular Files<3>. + @end menu -@node Wide_Wide_Text_IO Stream Pointer Positioning +@node Stream Pointer Positioning<3>,Reading and Writing Non-Regular Files<3>,,Wide_Wide_Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o stream-pointer-positioning-2}@anchor{260}@anchor{gnat_rm/the_implementation_of_standard_i_o id17}@anchor{261} @subsection Stream Pointer Positioning -@noindent -@code{Ada.Wide_Wide_Text_IO} is similar to @code{Ada.Text_IO} in its handling -of stream pointer positioning (@pxref{Text_IO}). There is one additional + +@cite{Ada.Wide_Wide_Text_IO} is similar to @cite{Ada.Text_IO} in its handling +of stream pointer positioning (@ref{24b,,Text_IO}). There is one additional case: -If @code{Ada.Wide_Wide_Text_IO.Look_Ahead} reads a character outside the -normal lower ASCII set (i.e.@: a character in the range: +If @cite{Ada.Wide_Wide_Text_IO.Look_Ahead} reads a character outside the +normal lower ASCII set (i.e., a character in the range: -@smallexample @c ada +@example Wide_Wide_Character'Val (16#0080#) .. Wide_Wide_Character'Val (16#10FFFF#) -@end smallexample +@end example -@noindent then although the logical position of the file pointer is unchanged by -the @code{Look_Ahead} call, the stream is physically positioned past the +the @cite{Look_Ahead} call, the stream is physically positioned past the wide character sequence. Again this is to avoid the need for buffering -or backup, and all @code{Wide_Wide_Text_IO} routines check the internal +or backup, and all @cite{Wide_Wide_Text_IO} routines check the internal indication that this situation has occurred so that this is not visible -to a normal program using @code{Wide_Wide_Text_IO}. However, this discrepancy +to a normal program using @cite{Wide_Wide_Text_IO}. However, this discrepancy can be observed if the wide text file shares a stream with another file. -@node Wide_Wide_Text_IO Reading and Writing Non-Regular Files +@node Reading and Writing Non-Regular Files<3>,,Stream Pointer Positioning<3>,Wide_Wide_Text_IO +@anchor{gnat_rm/the_implementation_of_standard_i_o id18}@anchor{262}@anchor{gnat_rm/the_implementation_of_standard_i_o reading-and-writing-non-regular-files-2}@anchor{263} @subsection Reading and Writing Non-Regular Files -@noindent + As in the case of Text_IO, when a non-regular file is read, it is assumed that the file contains no page marks (any form characters are -treated as data characters), and @code{End_Of_Page} always returns -@code{False}. Similarly, the end of file indication is not sticky, so +treated as data characters), and @cite{End_Of_Page} always returns +@cite{False}. Similarly, the end of file indication is not sticky, so it is possible to read beyond an end of file. -@node Stream_IO +@node Stream_IO,Text Translation,Wide_Wide_Text_IO,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o id19}@anchor{264}@anchor{gnat_rm/the_implementation_of_standard_i_o stream-io}@anchor{265} @section Stream_IO -@noindent + A stream file is a sequence of bytes, where individual elements are written to the file as described in the Ada Reference Manual. The type -@code{Stream_Element} is simply a byte. There are two ways to read or +@cite{Stream_Element} is simply a byte. There are two ways to read or write a stream file. -@itemize @bullet -@item -The operations @code{Read} and @code{Write} directly read or write a + +@itemize * + +@item +The operations @cite{Read} and @cite{Write} directly read or write a sequence of stream elements with no control information. -@item +@item The stream attributes applied to a stream file transfer data in the manner described for stream attributes. @end itemize -@node Text Translation +@node Text Translation,Shared Files,Stream_IO,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o id20}@anchor{266}@anchor{gnat_rm/the_implementation_of_standard_i_o text-translation}@anchor{267} @section Text Translation -@noindent -@samp{Text_Translation=@var{xxx}} may be used as the Form parameter -passed to Text_IO.Create and Text_IO.Open. @samp{Text_Translation=@var{xxx}} + +@code{Text_Translation=xxx} may be used as the Form parameter +passed to Text_IO.Create and Text_IO.Open. @code{Text_Translation=xxx} has no effect on Unix systems. Possible values are: -@itemize @bullet -@item -@samp{@var{Yes} or @var{Text}} is the default, which means to +@itemize * + +@item +@code{Yes} or @code{Text} is the default, which means to translate LF to/from CR/LF on Windows systems. -@samp{@var{No}} disables this translation; i.e. it -uses binary mode. For output files, @samp{Text_Translation=@var{No}} +@code{No} disables this translation; i.e. it +uses binary mode. For output files, @code{Text_Translation=No} may be used to create Unix-style files on Windows. -@item -@samp{@var{wtext}} translation enabled in Unicode mode. +@item +@code{wtext} translation enabled in Unicode mode. (corresponds to _O_WTEXT). -@item -@samp{@var{u8text}} translation enabled in Unicode UTF-8 mode. +@item +@code{u8text} translation enabled in Unicode UTF-8 mode. (corresponds to O_U8TEXT). -@item -@samp{@var{u16text}} translation enabled in Unicode UTF-16 +@item +@code{u16text} translation enabled in Unicode UTF-16 mode. (corresponds to_O_U16TEXT). - @end itemize - - -@node Shared Files +@node Shared Files,Filenames encoding,Text Translation,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o id21}@anchor{268}@anchor{gnat_rm/the_implementation_of_standard_i_o shared-files}@anchor{269} @section Shared Files -@noindent + Section A.14 of the Ada Reference Manual allows implementations to provide a wide variety of behavior if an attempt is made to access the same external file with two or more internal files. @@ -18613,80 +21235,89 @@ To provide a full range of functionality, while at the same time minimizing the problems of portability caused by this implementation dependence, GNAT handles file sharing as follows: -@itemize @bullet -@item -In the absence of a @samp{shared=@var{xxx}} form parameter, an attempt + +@itemize * + +@item +In the absence of a @code{shared=xxx} form parameter, an attempt to open two or more files with the same full name is considered an error -and is not supported. The exception @code{Use_Error} will be +and is not supported. The exception @cite{Use_Error} will be raised. Note that a file that is not explicitly closed by the program remains open until the program terminates. -@item -If the form parameter @samp{shared=no} appears in the form string, the +@item +If the form parameter @code{shared=no} appears in the form string, the file can be opened or created with its own separate stream identifier, regardless of whether other files sharing the same external file are opened. The exact effect depends on how the C stream routines handle multiple accesses to the same external files using separate streams. -@item -If the form parameter @samp{shared=yes} appears in the form string for +@item +If the form parameter @code{shared=yes} appears in the form string for each of two or more files opened using the same full name, the same stream is shared between these files, and the semantics are as described in Ada Reference Manual, Section A.14. @end itemize -@noindent When a program that opens multiple files with the same name is ported from another Ada compiler to GNAT, the effect will be that -@code{Use_Error} is raised. +@cite{Use_Error} is raised. The documentation of the original compiler and the documentation of the program should then be examined to determine if file sharing was -expected, and @samp{shared=@var{xxx}} parameters added to @code{Open} -and @code{Create} calls as required. +expected, and @code{shared=xxx} parameters added to @cite{Open} +and @cite{Create} calls as required. When a program is ported from GNAT to some other Ada compiler, no -special attention is required unless the @samp{shared=@var{xxx}} form +special attention is required unless the @code{shared=xxx} form parameter is used in the program. In this case, you must examine the documentation of the new compiler to see if it supports the required file sharing semantics, and form strings modified appropriately. Of course it may be the case that the program cannot be ported if the target compiler does not support the required functionality. The best approach in writing portable code is to avoid file sharing (and hence -the use of the @samp{shared=@var{xxx}} parameter in the form string) +the use of the @code{shared=xxx} parameter in the form string) completely. One common use of file sharing in Ada 83 is the use of instantiations of Sequential_IO on the same file with different types, to achieve heterogeneous input-output. Although this approach will work in GNAT if -@samp{shared=yes} is specified, it is preferable in Ada to use Stream_IO +@code{shared=yes} is specified, it is preferable in Ada to use Stream_IO for this purpose (using the stream attributes) -@node Filenames encoding +@node Filenames encoding,File content encoding,Shared Files,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o filenames-encoding}@anchor{26a}@anchor{gnat_rm/the_implementation_of_standard_i_o id22}@anchor{26b} @section Filenames encoding -@noindent + An encoding form parameter can be used to specify the filename -encoding @samp{encoding=@var{xxx}}. +encoding @code{encoding=xxx}. -@itemize @bullet -@item -If the form parameter @samp{encoding=utf8} appears in the form string, the + +@itemize * + +@item +If the form parameter @code{encoding=utf8} appears in the form string, the filename must be encoded in UTF-8. -@item -If the form parameter @samp{encoding=8bits} appears in the form +@item +If the form parameter @code{encoding=8bits} appears in the form string, the filename must be a standard 8bits string. @end itemize -In the absence of a @samp{encoding=@var{xxx}} form parameter, the -encoding is controlled by the @samp{GNAT_CODE_PAGE} environment -variable. And if not set @samp{utf8} is assumed. +In the absence of a @code{encoding=xxx} form parameter, the +encoding is controlled by the @code{GNAT_CODE_PAGE} environment +variable. And if not set @code{utf8} is assumed. + + +@table @asis + +@item @emph{CP_ACP} -@table @samp -@item CP_ACP The current system Windows ANSI code page. -@item CP_UTF8 + +@item @emph{CP_UTF8} + UTF-8 encoding @end table @@ -18694,66 +21325,151 @@ This encoding form parameter is only supported on the Windows platform. On the other Operating Systems the run-time is supporting UTF-8 natively. -@node File content encoding +@node File content encoding,Open Modes,Filenames encoding,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o file-content-encoding}@anchor{26c}@anchor{gnat_rm/the_implementation_of_standard_i_o id23}@anchor{26d} @section File content encoding -@noindent + For text files it is possible to specify the encoding to use. This is -controlled by the by the @samp{GNAT_CCS_ENCODING} environment -variable. And if not set @samp{TEXT} is assumed. +controlled by the by the @code{GNAT_CCS_ENCODING} environment +variable. And if not set @code{TEXT} is assumed. The possible values are those supported on Windows: -@table @samp -@item TEXT + +@table @asis + +@item @emph{TEXT} + Translated text mode -@item WTEXT + +@item @emph{WTEXT} + Translated unicode encoding -@item U16TEXT + +@item @emph{U16TEXT} + Unicode 16-bit encoding -@item U8TEXT + +@item @emph{U8TEXT} + Unicode 8-bit encoding @end table This encoding is only supported on the Windows platform. -@node Open Modes +@node Open Modes,Operations on C Streams,File content encoding,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o open-modes}@anchor{26e}@anchor{gnat_rm/the_implementation_of_standard_i_o id24}@anchor{26f} @section Open Modes -@noindent -@code{Open} and @code{Create} calls result in a call to @code{fopen} + +@cite{Open} and @cite{Create} calls result in a call to @cite{fopen} using the mode shown in the following table: -@sp 2 -@center @code{Open} and @code{Create} Call Modes -@smallexample - @b{OPEN } @b{CREATE} -Append_File "r+" "w+" -In_File "r" "w+" -Out_File (Direct_IO) "r+" "w" -Out_File (all other cases) "w" "w" -Inout_File "r+" "w+" -@end smallexample - -@noindent -If text file translation is required, then either @samp{b} or @samp{t} + +@multitable {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxx} +@headitem + +@cite{Open} and @cite{Create} Call Modes + +@tab + +@tab + +@item + +@tab + +@strong{OPEN} + +@tab + +@strong{CREATE} + +@item + +Append_File + +@tab + +"r+" + +@tab + +"w+" + +@item + +In_File + +@tab + +"r" + +@tab + +"w+" + +@item + +Out_File (Direct_IO) + +@tab + +"r+" + +@tab + +"w" + +@item + +Out_File (all other cases) + +@tab + +"w" + +@tab + +"w" + +@item + +Inout_File + +@tab + +"r+" + +@tab + +"w+" + +@end multitable + + +If text file translation is required, then either @code{b} or @code{t} is added to the mode, depending on the setting of Text. Text file translation refers to the mapping of CR/LF sequences in an external file to LF characters internally. This mapping only occurs in DOS and DOS-like systems, and is not relevant to other systems. -A special case occurs with Stream_IO@. As shown in the above table, the -file is initially opened in @samp{r} or @samp{w} mode for the -@code{In_File} and @code{Out_File} cases. If a @code{Set_Mode} operation +A special case occurs with Stream_IO. As shown in the above table, the +file is initially opened in @code{r} or @code{w} mode for the +@cite{In_File} and @cite{Out_File} cases. If a @cite{Set_Mode} operation subsequently requires switching from reading to writing or vice-versa, -then the file is reopened in @samp{r+} mode to permit the required operation. +then the file is reopened in @code{r+} mode to permit the required operation. -@node Operations on C Streams +@node Operations on C Streams,Interfacing to C Streams,Open Modes,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o operations-on-c-streams}@anchor{270}@anchor{gnat_rm/the_implementation_of_standard_i_o id25}@anchor{271} @section Operations on C Streams -The package @code{Interfaces.C_Streams} provides an Ada program with direct + + +The package @cite{Interfaces.C_Streams} provides an Ada program with direct access to the C library functions for operations on C streams: -@smallexample @c adanocomment +@example package Interfaces.C_Streams is -- Note: the reason we do not use the types that are in -- Interfaces.C is that we want to avoid dragging in the @@ -18883,7 +21599,7 @@ package Interfaces.C_Streams is -- If text_translation_required is true, then the following -- functions may be used to dynamically switch a file from -- binary to text mode or vice versa. These functions have - -- no effect if text_translation_required is false (i.e.@: in + -- no effect if text_translation_required is false (i.e., in -- normal UNIX mode). Use fileno to get a stream handle. procedure set_binary_mode (handle : int); procedure set_text_mode (handle : int); @@ -18903,18 +21619,30 @@ package Interfaces.C_Streams is -- Maximum length of an allowable full path name on the -- system, including a terminating NUL character. end Interfaces.C_Streams; -@end smallexample +@end example -@node Interfacing to C Streams +@node Interfacing to C Streams,,Operations on C Streams,The Implementation of Standard I/O +@anchor{gnat_rm/the_implementation_of_standard_i_o interfacing-to-c-streams}@anchor{272}@anchor{gnat_rm/the_implementation_of_standard_i_o id26}@anchor{273} @section Interfacing to C Streams -@noindent + The packages in this section permit interfacing Ada files to C Stream operations. -@smallexample @c ada +@example +with Interfaces.C_Streams; +package Ada.Sequential_IO.C_Streams is + function C_Stream (F : File_Type) + return Interfaces.C_Streams.FILEs; + procedure Open + (File : in out File_Type; + Mode : in File_Mode; + C_Stream : in Interfaces.C_Streams.FILEs; + Form : in String := ""); +end Ada.Sequential_IO.C_Streams; + with Interfaces.C_Streams; - package Ada.Sequential_IO.C_Streams is + package Ada.Direct_IO.C_Streams is function C_Stream (F : File_Type) return Interfaces.C_Streams.FILEs; procedure Open @@ -18922,54 +21650,10 @@ operations. Mode : in File_Mode; C_Stream : in Interfaces.C_Streams.FILEs; Form : in String := ""); - end Ada.Sequential_IO.C_Streams; - - with Interfaces.C_Streams; - package Ada.Direct_IO.C_Streams is - function C_Stream (F : File_Type) - return Interfaces.C_Streams.FILEs; - procedure Open - (File : in out File_Type; - Mode : in File_Mode; - C_Stream : in Interfaces.C_Streams.FILEs; - Form : in String := ""); - end Ada.Direct_IO.C_Streams; - - with Interfaces.C_Streams; - package Ada.Text_IO.C_Streams is - function C_Stream (F : File_Type) - return Interfaces.C_Streams.FILEs; - procedure Open - (File : in out File_Type; - Mode : in File_Mode; - C_Stream : in Interfaces.C_Streams.FILEs; - Form : in String := ""); - end Ada.Text_IO.C_Streams; - - with Interfaces.C_Streams; - package Ada.Wide_Text_IO.C_Streams is - function C_Stream (F : File_Type) - return Interfaces.C_Streams.FILEs; - procedure Open - (File : in out File_Type; - Mode : in File_Mode; - C_Stream : in Interfaces.C_Streams.FILEs; - Form : in String := ""); - end Ada.Wide_Text_IO.C_Streams; - - with Interfaces.C_Streams; - package Ada.Wide_Wide_Text_IO.C_Streams is - function C_Stream (F : File_Type) - return Interfaces.C_Streams.FILEs; - procedure Open - (File : in out File_Type; - Mode : in File_Mode; - C_Stream : in Interfaces.C_Streams.FILEs; - Form : in String := ""); - end Ada.Wide_Wide_Text_IO.C_Streams; + end Ada.Direct_IO.C_Streams; with Interfaces.C_Streams; - package Ada.Stream_IO.C_Streams is + package Ada.Text_IO.C_Streams is function C_Stream (F : File_Type) return Interfaces.C_Streams.FILEs; procedure Open @@ -18977,31 +21661,64 @@ operations. Mode : in File_Mode; C_Stream : in Interfaces.C_Streams.FILEs; Form : in String := ""); - end Ada.Stream_IO.C_Streams; -@end smallexample + end Ada.Text_IO.C_Streams; -@noindent -In each of these six packages, the @code{C_Stream} function obtains the -@code{FILE} pointer from a currently opened Ada file. It is then -possible to use the @code{Interfaces.C_Streams} package to operate on + with Interfaces.C_Streams; + package Ada.Wide_Text_IO.C_Streams is + function C_Stream (F : File_Type) + return Interfaces.C_Streams.FILEs; + procedure Open + (File : in out File_Type; + Mode : in File_Mode; + C_Stream : in Interfaces.C_Streams.FILEs; + Form : in String := ""); +end Ada.Wide_Text_IO.C_Streams; + + with Interfaces.C_Streams; + package Ada.Wide_Wide_Text_IO.C_Streams is + function C_Stream (F : File_Type) + return Interfaces.C_Streams.FILEs; + procedure Open + (File : in out File_Type; + Mode : in File_Mode; + C_Stream : in Interfaces.C_Streams.FILEs; + Form : in String := ""); +end Ada.Wide_Wide_Text_IO.C_Streams; + +with Interfaces.C_Streams; +package Ada.Stream_IO.C_Streams is + function C_Stream (F : File_Type) + return Interfaces.C_Streams.FILEs; + procedure Open + (File : in out File_Type; + Mode : in File_Mode; + C_Stream : in Interfaces.C_Streams.FILEs; + Form : in String := ""); +end Ada.Stream_IO.C_Streams; +@end example + +In each of these six packages, the @cite{C_Stream} function obtains the +@cite{FILE} pointer from a currently opened Ada file. It is then +possible to use the @cite{Interfaces.C_Streams} package to operate on this stream, or the stream can be passed to a C program which can operate on it directly. Of course the program is responsible for ensuring that only appropriate sequences of operations are executed. One particular use of relevance to an Ada program is that the -@code{setvbuf} function can be used to control the buffering of the +@cite{setvbuf} function can be used to control the buffering of the stream used by an Ada file. In the absence of such a call the standard default buffering is used. -The @code{Open} procedures in these packages open a file giving an +The @cite{Open} procedures in these packages open a file giving an existing C Stream instead of a file name. Typically this stream is imported from a C program, allowing an Ada file to operate on an existing C file. -@node The GNAT Library +@node The GNAT Library,Interfacing to Other Languages,The Implementation of Standard I/O,Top +@anchor{gnat_rm/the_gnat_library the-gnat-library}@anchor{10}@anchor{gnat_rm/the_gnat_library doc}@anchor{274}@anchor{gnat_rm/the_gnat_library id1}@anchor{275} @chapter The GNAT Library -@noindent + The GNAT library contains a number of general and special purpose packages. It represents functionality that the GNAT developers have found useful, and which is made available to GNAT users. The packages described here are fully @@ -19014,251 +21731,270 @@ The full documentation is found in the spec file for the package. The full sources of these library packages, including both spec and body, are provided with all GNAT releases. For example, to find out the full specifications of the SPITBOL pattern matching capability, including a full tutorial and -extensive examples, look in the @file{g-spipat.ads} file in the library. +extensive examples, look in the @code{g-spipat.ads} file in the library. -For each entry here, the package name (as it would appear in a @code{with} +For each entry here, the package name (as it would appear in a @cite{with} clause) is given, followed by the name of the corresponding spec file in -parentheses. The packages are children in four hierarchies, @code{Ada}, -@code{Interfaces}, @code{System}, and @code{GNAT}, the latter being a +parentheses. The packages are children in four hierarchies, @cite{Ada}, +@cite{Interfaces}, @cite{System}, and @cite{GNAT}, the latter being a GNAT-specific hierarchy. Note that an application program should only use packages in one of these four hierarchies if the package is defined in the Ada Reference Manual, or is listed in this section of the GNAT Programmers Reference Manual. All other units should be considered internal implementation units and -should not be directly @code{with}'ed by application code. The use of -a @code{with} statement that references one of these internal implementation +should not be directly @cite{with}'ed by application code. The use of +a @cite{with} statement that references one of these internal implementation units makes an application potentially dependent on changes in versions of GNAT, and will generate a warning message. @menu -* Ada.Characters.Latin_9 (a-chlat9.ads):: -* Ada.Characters.Wide_Latin_1 (a-cwila1.ads):: -* Ada.Characters.Wide_Latin_9 (a-cwila9.ads):: -* Ada.Characters.Wide_Wide_Latin_1 (a-chzla1.ads):: -* Ada.Characters.Wide_Wide_Latin_9 (a-chzla9.ads):: -* Ada.Containers.Formal_Doubly_Linked_Lists (a-cfdlli.ads):: -* Ada.Containers.Formal_Hashed_Maps (a-cfhama.ads):: -* Ada.Containers.Formal_Hashed_Sets (a-cfhase.ads):: -* Ada.Containers.Formal_Ordered_Maps (a-cforma.ads):: -* Ada.Containers.Formal_Ordered_Sets (a-cforse.ads):: -* Ada.Containers.Formal_Vectors (a-cofove.ads):: -* Ada.Containers.Formal_Indefinite_Vectors (a-cfinve.ads):: -* Ada.Containers.Bounded_Holders (a-coboho.ads):: -* Ada.Command_Line.Environment (a-colien.ads):: -* Ada.Command_Line.Remove (a-colire.ads):: -* Ada.Command_Line.Response_File (a-clrefi.ads):: -* Ada.Direct_IO.C_Streams (a-diocst.ads):: -* Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads):: -* Ada.Exceptions.Last_Chance_Handler (a-elchha.ads):: -* Ada.Exceptions.Traceback (a-exctra.ads):: -* Ada.Sequential_IO.C_Streams (a-siocst.ads):: -* Ada.Streams.Stream_IO.C_Streams (a-ssicst.ads):: -* Ada.Strings.Unbounded.Text_IO (a-suteio.ads):: -* Ada.Strings.Wide_Unbounded.Wide_Text_IO (a-swuwti.ads):: -* Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO (a-szuzti.ads):: -* Ada.Text_IO.C_Streams (a-tiocst.ads):: -* Ada.Text_IO.Reset_Standard_Files (a-tirsfi.ads):: -* Ada.Wide_Characters.Unicode (a-wichun.ads):: -* Ada.Wide_Text_IO.C_Streams (a-wtcstr.ads):: -* Ada.Wide_Text_IO.Reset_Standard_Files (a-wrstfi.ads):: -* Ada.Wide_Wide_Characters.Unicode (a-zchuni.ads):: -* Ada.Wide_Wide_Text_IO.C_Streams (a-ztcstr.ads):: -* Ada.Wide_Wide_Text_IO.Reset_Standard_Files (a-zrstfi.ads):: -* GNAT.Altivec (g-altive.ads):: -* GNAT.Altivec.Conversions (g-altcon.ads):: -* GNAT.Altivec.Vector_Operations (g-alveop.ads):: -* GNAT.Altivec.Vector_Types (g-alvety.ads):: -* GNAT.Altivec.Vector_Views (g-alvevi.ads):: -* GNAT.Array_Split (g-arrspl.ads):: -* GNAT.AWK (g-awk.ads):: -* GNAT.Bounded_Buffers (g-boubuf.ads):: -* GNAT.Bounded_Mailboxes (g-boumai.ads):: -* GNAT.Bubble_Sort (g-bubsor.ads):: -* GNAT.Bubble_Sort_A (g-busora.ads):: -* GNAT.Bubble_Sort_G (g-busorg.ads):: -* GNAT.Byte_Order_Mark (g-byorma.ads):: -* GNAT.Byte_Swapping (g-bytswa.ads):: -* GNAT.Calendar (g-calend.ads):: -* GNAT.Calendar.Time_IO (g-catiio.ads):: -* GNAT.Case_Util (g-casuti.ads):: -* GNAT.CGI (g-cgi.ads):: -* GNAT.CGI.Cookie (g-cgicoo.ads):: -* GNAT.CGI.Debug (g-cgideb.ads):: -* GNAT.Command_Line (g-comlin.ads):: -* GNAT.Compiler_Version (g-comver.ads):: -* GNAT.Ctrl_C (g-ctrl_c.ads):: -* GNAT.CRC32 (g-crc32.ads):: -* GNAT.Current_Exception (g-curexc.ads):: -* GNAT.Debug_Pools (g-debpoo.ads):: -* GNAT.Debug_Utilities (g-debuti.ads):: -* GNAT.Decode_String (g-decstr.ads):: -* GNAT.Decode_UTF8_String (g-deutst.ads):: -* GNAT.Directory_Operations (g-dirope.ads):: -* GNAT.Directory_Operations.Iteration (g-diopit.ads):: -* GNAT.Dynamic_HTables (g-dynhta.ads):: -* GNAT.Dynamic_Tables (g-dyntab.ads):: -* GNAT.Encode_String (g-encstr.ads):: -* GNAT.Encode_UTF8_String (g-enutst.ads):: -* GNAT.Exception_Actions (g-excact.ads):: -* GNAT.Exception_Traces (g-exctra.ads):: -* GNAT.Exceptions (g-except.ads):: -* GNAT.Expect (g-expect.ads):: -* GNAT.Expect.TTY (g-exptty.ads):: -* GNAT.Float_Control (g-flocon.ads):: -* GNAT.Formatted_String (g-forstr.ads):: -* GNAT.Heap_Sort (g-heasor.ads):: -* GNAT.Heap_Sort_A (g-hesora.ads):: -* GNAT.Heap_Sort_G (g-hesorg.ads):: -* GNAT.HTable (g-htable.ads):: -* GNAT.IO (g-io.ads):: -* GNAT.IO_Aux (g-io_aux.ads):: -* GNAT.Lock_Files (g-locfil.ads):: -* GNAT.MBBS_Discrete_Random (g-mbdira.ads):: -* GNAT.MBBS_Float_Random (g-mbflra.ads):: -* GNAT.MD5 (g-md5.ads):: -* GNAT.Memory_Dump (g-memdum.ads):: -* GNAT.Most_Recent_Exception (g-moreex.ads):: -* GNAT.OS_Lib (g-os_lib.ads):: -* GNAT.Perfect_Hash_Generators (g-pehage.ads):: -* GNAT.Random_Numbers (g-rannum.ads):: -* GNAT.Regexp (g-regexp.ads):: -* GNAT.Registry (g-regist.ads):: -* GNAT.Regpat (g-regpat.ads):: -* GNAT.Rewrite_Data (g-rewdat.ads):: -* GNAT.Secondary_Stack_Info (g-sestin.ads):: -* GNAT.Semaphores (g-semaph.ads):: -* GNAT.Serial_Communications (g-sercom.ads):: -* GNAT.SHA1 (g-sha1.ads):: -* GNAT.SHA224 (g-sha224.ads):: -* GNAT.SHA256 (g-sha256.ads):: -* GNAT.SHA384 (g-sha384.ads):: -* GNAT.SHA512 (g-sha512.ads):: -* GNAT.Signals (g-signal.ads):: -* GNAT.Sockets (g-socket.ads):: -* GNAT.Source_Info (g-souinf.ads):: -* GNAT.Spelling_Checker (g-speche.ads):: -* GNAT.Spelling_Checker_Generic (g-spchge.ads):: -* GNAT.Spitbol.Patterns (g-spipat.ads):: -* GNAT.Spitbol (g-spitbo.ads):: -* GNAT.Spitbol.Table_Boolean (g-sptabo.ads):: -* GNAT.Spitbol.Table_Integer (g-sptain.ads):: -* GNAT.Spitbol.Table_VString (g-sptavs.ads):: -* GNAT.SSE (g-sse.ads):: -* GNAT.SSE.Vector_Types (g-ssvety.ads):: -* GNAT.Strings (g-string.ads):: -* GNAT.String_Split (g-strspl.ads):: -* GNAT.Table (g-table.ads):: -* GNAT.Task_Lock (g-tasloc.ads):: -* GNAT.Threads (g-thread.ads):: -* GNAT.Time_Stamp (g-timsta.ads):: -* GNAT.Traceback (g-traceb.ads):: -* GNAT.Traceback.Symbolic (g-trasym.ads):: -* GNAT.UTF_32 (g-utf_32.ads):: -* GNAT.UTF_32_Spelling_Checker (g-u3spch.ads):: -* GNAT.Wide_Spelling_Checker (g-wispch.ads):: -* GNAT.Wide_String_Split (g-wistsp.ads):: -* GNAT.Wide_Wide_Spelling_Checker (g-zspche.ads):: -* GNAT.Wide_Wide_String_Split (g-zistsp.ads):: -* Interfaces.C.Extensions (i-cexten.ads):: -* Interfaces.C.Streams (i-cstrea.ads):: -* Interfaces.Packed_Decimal (i-pacdec.ads):: -* Interfaces.VxWorks (i-vxwork.ads):: -* Interfaces.VxWorks.IO (i-vxwoio.ads):: -* System.Address_Image (s-addima.ads):: -* System.Assertions (s-assert.ads):: -* System.Atomic_Counters (s-atocou.ads):: -* System.Memory (s-memory.ads):: -* System.Multiprocessors (s-multip.ads):: -* System.Multiprocessors.Dispatching_Domains (s-mudido.ads):: -* System.Partition_Interface (s-parint.ads):: -* System.Pool_Global (s-pooglo.ads):: -* System.Pool_Local (s-pooloc.ads):: -* System.Restrictions (s-restri.ads):: -* System.Rident (s-rident.ads):: -* System.Strings.Stream_Ops (s-ststop.ads):: -* System.Unsigned_Types (s-unstyp.ads):: -* System.Wch_Cnv (s-wchcnv.ads):: -* System.Wch_Con (s-wchcon.ads):: +* Ada.Characters.Latin_9 (a-chlat9.ads): Ada Characters Latin_9 a-chlat9 ads. +* Ada.Characters.Wide_Latin_1 (a-cwila1.ads): Ada Characters Wide_Latin_1 a-cwila1 ads. +* Ada.Characters.Wide_Latin_9 (a-cwila1.ads): Ada Characters Wide_Latin_9 a-cwila1 ads. +* Ada.Characters.Wide_Wide_Latin_1 (a-chzla1.ads): Ada Characters Wide_Wide_Latin_1 a-chzla1 ads. +* Ada.Characters.Wide_Wide_Latin_9 (a-chzla9.ads): Ada Characters Wide_Wide_Latin_9 a-chzla9 ads. +* Ada.Containers.Formal_Doubly_Linked_Lists (a-cfdlli.ads): Ada Containers Formal_Doubly_Linked_Lists a-cfdlli ads. +* Ada.Containers.Formal_Hashed_Maps (a-cfhama.ads): Ada Containers Formal_Hashed_Maps a-cfhama ads. +* Ada.Containers.Formal_Hashed_Sets (a-cfhase.ads): Ada Containers Formal_Hashed_Sets a-cfhase ads. +* Ada.Containers.Formal_Ordered_Maps (a-cforma.ads): Ada Containers Formal_Ordered_Maps a-cforma ads. +* Ada.Containers.Formal_Ordered_Sets (a-cforse.ads): Ada Containers Formal_Ordered_Sets a-cforse ads. +* Ada.Containers.Formal_Vectors (a-cofove.ads): Ada Containers Formal_Vectors a-cofove ads. +* Ada.Containers.Formal_Indefinite_Vectors (a-cfinve.ads): Ada Containers Formal_Indefinite_Vectors a-cfinve ads. +* Ada.Containers.Bounded_Holders (a-coboho.ads): Ada Containers Bounded_Holders a-coboho ads. +* Ada.Command_Line.Environment (a-colien.ads): Ada Command_Line Environment a-colien ads. +* Ada.Command_Line.Remove (a-colire.ads): Ada Command_Line Remove a-colire ads. +* Ada.Command_Line.Response_File (a-clrefi.ads): Ada Command_Line Response_File a-clrefi ads. +* Ada.Direct_IO.C_Streams (a-diocst.ads): Ada Direct_IO C_Streams a-diocst ads. +* Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads): Ada Exceptions Is_Null_Occurrence a-einuoc ads. +* Ada.Exceptions.Last_Chance_Handler (a-elchha.ads): Ada Exceptions Last_Chance_Handler a-elchha ads. +* Ada.Exceptions.Traceback (a-exctra.ads): Ada Exceptions Traceback a-exctra ads. +* Ada.Sequential_IO.C_Streams (a-siocst.ads): Ada Sequential_IO C_Streams a-siocst ads. +* Ada.Streams.Stream_IO.C_Streams (a-ssicst.ads): Ada Streams Stream_IO C_Streams a-ssicst ads. +* Ada.Strings.Unbounded.Text_IO (a-suteio.ads): Ada Strings Unbounded Text_IO a-suteio ads. +* Ada.Strings.Wide_Unbounded.Wide_Text_IO (a-swuwti.ads): Ada Strings Wide_Unbounded Wide_Text_IO a-swuwti ads. +* Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO (a-szuzti.ads): Ada Strings Wide_Wide_Unbounded Wide_Wide_Text_IO a-szuzti ads. +* Ada.Text_IO.C_Streams (a-tiocst.ads): Ada Text_IO C_Streams a-tiocst ads. +* Ada.Text_IO.Reset_Standard_Files (a-tirsfi.ads): Ada Text_IO Reset_Standard_Files a-tirsfi ads. +* Ada.Wide_Characters.Unicode (a-wichun.ads): Ada Wide_Characters Unicode a-wichun ads. +* Ada.Wide_Text_IO.C_Streams (a-wtcstr.ads): Ada Wide_Text_IO C_Streams a-wtcstr ads. +* Ada.Wide_Text_IO.Reset_Standard_Files (a-wrstfi.ads): Ada Wide_Text_IO Reset_Standard_Files a-wrstfi ads. +* Ada.Wide_Wide_Characters.Unicode (a-zchuni.ads): Ada Wide_Wide_Characters Unicode a-zchuni ads. +* Ada.Wide_Wide_Text_IO.C_Streams (a-ztcstr.ads): Ada Wide_Wide_Text_IO C_Streams a-ztcstr ads. +* Ada.Wide_Wide_Text_IO.Reset_Standard_Files (a-zrstfi.ads): Ada Wide_Wide_Text_IO Reset_Standard_Files a-zrstfi ads. +* GNAT.Altivec (g-altive.ads): GNAT Altivec g-altive ads. +* GNAT.Altivec.Conversions (g-altcon.ads): GNAT Altivec Conversions g-altcon ads. +* GNAT.Altivec.Vector_Operations (g-alveop.ads): GNAT Altivec Vector_Operations g-alveop ads. +* GNAT.Altivec.Vector_Types (g-alvety.ads): GNAT Altivec Vector_Types g-alvety ads. +* GNAT.Altivec.Vector_Views (g-alvevi.ads): GNAT Altivec Vector_Views g-alvevi ads. +* GNAT.Array_Split (g-arrspl.ads): GNAT Array_Split g-arrspl ads. +* GNAT.AWK (g-awk.ads): GNAT AWK g-awk ads. +* GNAT.Bounded_Buffers (g-boubuf.ads): GNAT Bounded_Buffers g-boubuf ads. +* GNAT.Bounded_Mailboxes (g-boumai.ads): GNAT Bounded_Mailboxes g-boumai ads. +* GNAT.Bubble_Sort (g-bubsor.ads): GNAT Bubble_Sort g-bubsor ads. +* GNAT.Bubble_Sort_A (g-busora.ads): GNAT Bubble_Sort_A g-busora ads. +* GNAT.Bubble_Sort_G (g-busorg.ads): GNAT Bubble_Sort_G g-busorg ads. +* GNAT.Byte_Order_Mark (g-byorma.ads): GNAT Byte_Order_Mark g-byorma ads. +* GNAT.Byte_Swapping (g-bytswa.ads): GNAT Byte_Swapping g-bytswa ads. +* GNAT.Calendar (g-calend.ads): GNAT Calendar g-calend ads. +* GNAT.Calendar.Time_IO (g-catiio.ads): GNAT Calendar Time_IO g-catiio ads. +* GNAT.CRC32 (g-crc32.ads): GNAT CRC32 g-crc32 ads. +* GNAT.Case_Util (g-casuti.ads): GNAT Case_Util g-casuti ads. +* GNAT.CGI (g-cgi.ads): GNAT CGI g-cgi ads. +* GNAT.CGI.Cookie (g-cgicoo.ads): GNAT CGI Cookie g-cgicoo ads. +* GNAT.CGI.Debug (g-cgideb.ads): GNAT CGI Debug g-cgideb ads. +* GNAT.Command_Line (g-comlin.ads): GNAT Command_Line g-comlin ads. +* GNAT.Compiler_Version (g-comver.ads): GNAT Compiler_Version g-comver ads. +* GNAT.Ctrl_C (g-ctrl_c.ads): GNAT Ctrl_C g-ctrl_c ads. +* GNAT.Current_Exception (g-curexc.ads): GNAT Current_Exception g-curexc ads. +* GNAT.Debug_Pools (g-debpoo.ads): GNAT Debug_Pools g-debpoo ads. +* GNAT.Debug_Utilities (g-debuti.ads): GNAT Debug_Utilities g-debuti ads. +* GNAT.Decode_String (g-decstr.ads): GNAT Decode_String g-decstr ads. +* GNAT.Decode_UTF8_String (g-deutst.ads): GNAT Decode_UTF8_String g-deutst ads. +* GNAT.Directory_Operations (g-dirope.ads): GNAT Directory_Operations g-dirope ads. +* GNAT.Directory_Operations.Iteration (g-diopit.ads): GNAT Directory_Operations Iteration g-diopit ads. +* GNAT.Dynamic_HTables (g-dynhta.ads): GNAT Dynamic_HTables g-dynhta ads. +* GNAT.Dynamic_Tables (g-dyntab.ads): GNAT Dynamic_Tables g-dyntab ads. +* GNAT.Encode_String (g-encstr.ads): GNAT Encode_String g-encstr ads. +* GNAT.Encode_UTF8_String (g-enutst.ads): GNAT Encode_UTF8_String g-enutst ads. +* GNAT.Exception_Actions (g-excact.ads): GNAT Exception_Actions g-excact ads. +* GNAT.Exception_Traces (g-exctra.ads): GNAT Exception_Traces g-exctra ads. +* GNAT.Exceptions (g-expect.ads): GNAT Exceptions g-expect ads. +* GNAT.Expect (g-expect.ads): GNAT Expect g-expect ads. +* GNAT.Expect.TTY (g-exptty.ads): GNAT Expect TTY g-exptty ads. +* GNAT.Float_Control (g-flocon.ads): GNAT Float_Control g-flocon ads. +* GNAT.Formatted_String (g-forstr.ads): GNAT Formatted_String g-forstr ads. +* GNAT.Heap_Sort (g-heasor.ads): GNAT Heap_Sort g-heasor ads. +* GNAT.Heap_Sort_A (g-hesora.ads): GNAT Heap_Sort_A g-hesora ads. +* GNAT.Heap_Sort_G (g-hesorg.ads): GNAT Heap_Sort_G g-hesorg ads. +* GNAT.HTable (g-htable.ads): GNAT HTable g-htable ads. +* GNAT.IO (g-io.ads): GNAT IO g-io ads. +* GNAT.IO_Aux (g-io_aux.ads): GNAT IO_Aux g-io_aux ads. +* GNAT.Lock_Files (g-locfil.ads): GNAT Lock_Files g-locfil ads. +* GNAT.MBBS_Discrete_Random (g-mbdira.ads): GNAT MBBS_Discrete_Random g-mbdira ads. +* GNAT.MBBS_Float_Random (g-mbflra.ads): GNAT MBBS_Float_Random g-mbflra ads. +* GNAT.MD5 (g-md5.ads): GNAT MD5 g-md5 ads. +* GNAT.Memory_Dump (g-memdum.ads): GNAT Memory_Dump g-memdum ads. +* GNAT.Most_Recent_Exception (g-moreex.ads): GNAT Most_Recent_Exception g-moreex ads. +* GNAT.OS_Lib (g-os_lib.ads): GNAT OS_Lib g-os_lib ads. +* GNAT.Perfect_Hash_Generators (g-pehage.ads): GNAT Perfect_Hash_Generators g-pehage ads. +* GNAT.Random_Numbers (g-rannum.ads): GNAT Random_Numbers g-rannum ads. +* GNAT.Regexp (g-regexp.ads): GNAT Regexp g-regexp ads. +* GNAT.Registry (g-regist.ads): GNAT Registry g-regist ads. +* GNAT.Regpat (g-regpat.ads): GNAT Regpat g-regpat ads. +* GNAT.Rewrite_Data (g-rewdat.ads): GNAT Rewrite_Data g-rewdat ads. +* GNAT.Secondary_Stack_Info (g-sestin.ads): GNAT Secondary_Stack_Info g-sestin ads. +* GNAT.Semaphores (g-semaph.ads): GNAT Semaphores g-semaph ads. +* GNAT.Serial_Communications (g-sercom.ads): GNAT Serial_Communications g-sercom ads. +* GNAT.SHA1 (g-sha1.ads): GNAT SHA1 g-sha1 ads. +* GNAT.SHA224 (g-sha224.ads): GNAT SHA224 g-sha224 ads. +* GNAT.SHA256 (g-sha256.ads): GNAT SHA256 g-sha256 ads. +* GNAT.SHA384 (g-sha384.ads): GNAT SHA384 g-sha384 ads. +* GNAT.SHA512 (g-sha512.ads): GNAT SHA512 g-sha512 ads. +* GNAT.Signals (g-signal.ads): GNAT Signals g-signal ads. +* GNAT.Sockets (g-socket.ads): GNAT Sockets g-socket ads. +* GNAT.Source_Info (g-souinf.ads): GNAT Source_Info g-souinf ads. +* GNAT.Spelling_Checker (g-speche.ads): GNAT Spelling_Checker g-speche ads. +* GNAT.Spelling_Checker_Generic (g-spchge.ads): GNAT Spelling_Checker_Generic g-spchge ads. +* GNAT.Spitbol.Patterns (g-spipat.ads): GNAT Spitbol Patterns g-spipat ads. +* GNAT.Spitbol (g-spitbo.ads): GNAT Spitbol g-spitbo ads. +* GNAT.Spitbol.Table_Boolean (g-sptabo.ads): GNAT Spitbol Table_Boolean g-sptabo ads. +* GNAT.Spitbol.Table_Integer (g-sptain.ads): GNAT Spitbol Table_Integer g-sptain ads. +* GNAT.Spitbol.Table_VString (g-sptavs.ads): GNAT Spitbol Table_VString g-sptavs ads. +* GNAT.SSE (g-sse.ads): GNAT SSE g-sse ads. +* GNAT.SSE.Vector_Types (g-ssvety.ads): GNAT SSE Vector_Types g-ssvety ads. +* GNAT.Strings (g-string.ads): GNAT Strings g-string ads. +* GNAT.String_Split (g-strspl.ads): GNAT String_Split g-strspl ads. +* GNAT.Table (g-table.ads): GNAT Table g-table ads. +* GNAT.Task_Lock (g-tasloc.ads): GNAT Task_Lock g-tasloc ads. +* GNAT.Time_Stamp (g-timsta.ads): GNAT Time_Stamp g-timsta ads. +* GNAT.Threads (g-thread.ads): GNAT Threads g-thread ads. +* GNAT.Traceback (g-traceb.ads): GNAT Traceback g-traceb ads. +* GNAT.Traceback.Symbolic (g-trasym.ads): GNAT Traceback Symbolic g-trasym ads. +* GNAT.UTF_32 (g-table.ads): GNAT UTF_32 g-table ads. +* GNAT.Wide_Spelling_Checker (g-u3spch.ads): GNAT Wide_Spelling_Checker g-u3spch ads. +* GNAT.Wide_Spelling_Checker (g-wispch.ads): GNAT Wide_Spelling_Checker g-wispch ads. +* GNAT.Wide_String_Split (g-wistsp.ads): GNAT Wide_String_Split g-wistsp ads. +* GNAT.Wide_Wide_Spelling_Checker (g-zspche.ads): GNAT Wide_Wide_Spelling_Checker g-zspche ads. +* GNAT.Wide_Wide_String_Split (g-zistsp.ads): GNAT Wide_Wide_String_Split g-zistsp ads. +* Interfaces.C.Extensions (i-cexten.ads): Interfaces C Extensions i-cexten ads. +* Interfaces.C.Streams (i-cstrea.ads): Interfaces C Streams i-cstrea ads. +* Interfaces.Packed_Decimal (i-pacdec.ads): Interfaces Packed_Decimal i-pacdec ads. +* Interfaces.VxWorks (i-vxwork.ads): Interfaces VxWorks i-vxwork ads. +* Interfaces.VxWorks.IO (i-vxwoio.ads): Interfaces VxWorks IO i-vxwoio ads. +* System.Address_Image (s-addima.ads): System Address_Image s-addima ads. +* System.Assertions (s-assert.ads): System Assertions s-assert ads. +* System.Atomic_Counters (s-atocou.ads): System Atomic_Counters s-atocou ads. +* System.Memory (s-memory.ads): System Memory s-memory ads. +* System.Multiprocessors (s-multip.ads): System Multiprocessors s-multip ads. +* System.Multiprocessors.Dispatching_Domains (s-mudido.ads): System Multiprocessors Dispatching_Domains s-mudido ads. +* System.Partition_Interface (s-parint.ads): System Partition_Interface s-parint ads. +* System.Pool_Global (s-pooglo.ads): System Pool_Global s-pooglo ads. +* System.Pool_Local (s-pooloc.ads): System Pool_Local s-pooloc ads. +* System.Restrictions (s-restri.ads): System Restrictions s-restri ads. +* System.Rident (s-rident.ads): System Rident s-rident ads. +* System.Strings.Stream_Ops (s-ststop.ads): System Strings Stream_Ops s-ststop ads. +* System.Unsigned_Types (s-unstyp.ads): System Unsigned_Types s-unstyp ads. +* System.Wch_Cnv (s-wchcnv.ads): System Wch_Cnv s-wchcnv ads. +* System.Wch_Con (s-wchcon.ads): System Wch_Con s-wchcon ads. + @end menu -@node Ada.Characters.Latin_9 (a-chlat9.ads) -@section @code{Ada.Characters.Latin_9} (@file{a-chlat9.ads}) -@cindex @code{Ada.Characters.Latin_9} (@file{a-chlat9.ads}) -@cindex Latin_9 constants for Character +@node Ada Characters Latin_9 a-chlat9 ads,Ada Characters Wide_Latin_1 a-cwila1 ads,,The GNAT Library +@anchor{gnat_rm/the_gnat_library id2}@anchor{276}@anchor{gnat_rm/the_gnat_library ada-characters-latin-9-a-chlat9-ads}@anchor{277} +@section @cite{Ada.Characters.Latin_9} (@code{a-chlat9.ads}) + + +@geindex Ada.Characters.Latin_9 (a-chlat9.ads) -@noindent -This child of @code{Ada.Characters} +@geindex Latin_9 constants for Character + +This child of @cite{Ada.Characters} provides a set of definitions corresponding to those in the -RM-defined package @code{Ada.Characters.Latin_1} but with the -few modifications required for @code{Latin-9} +RM-defined package @cite{Ada.Characters.Latin_1} but with the +few modifications required for @cite{Latin-9} The provision of such a package is specifically authorized by the Ada Reference Manual (RM A.3.3(27)). -@node Ada.Characters.Wide_Latin_1 (a-cwila1.ads) -@section @code{Ada.Characters.Wide_Latin_1} (@file{a-cwila1.ads}) -@cindex @code{Ada.Characters.Wide_Latin_1} (@file{a-cwila1.ads}) -@cindex Latin_1 constants for Wide_Character +@node Ada Characters Wide_Latin_1 a-cwila1 ads,Ada Characters Wide_Latin_9 a-cwila1 ads,Ada Characters Latin_9 a-chlat9 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-characters-wide-latin-1-a-cwila1-ads}@anchor{278}@anchor{gnat_rm/the_gnat_library id3}@anchor{279} +@section @cite{Ada.Characters.Wide_Latin_1} (@code{a-cwila1.ads}) + + +@geindex Ada.Characters.Wide_Latin_1 (a-cwila1.ads) -@noindent -This child of @code{Ada.Characters} +@geindex Latin_1 constants for Wide_Character + +This child of @cite{Ada.Characters} provides a set of definitions corresponding to those in the -RM-defined package @code{Ada.Characters.Latin_1} but with the -types of the constants being @code{Wide_Character} -instead of @code{Character}. The provision of such a package +RM-defined package @cite{Ada.Characters.Latin_1} but with the +types of the constants being @cite{Wide_Character} +instead of @cite{Character}. The provision of such a package is specifically authorized by the Ada Reference Manual (RM A.3.3(27)). -@node Ada.Characters.Wide_Latin_9 (a-cwila9.ads) -@section @code{Ada.Characters.Wide_Latin_9} (@file{a-cwila1.ads}) -@cindex @code{Ada.Characters.Wide_Latin_9} (@file{a-cwila1.ads}) -@cindex Latin_9 constants for Wide_Character +@node Ada Characters Wide_Latin_9 a-cwila1 ads,Ada Characters Wide_Wide_Latin_1 a-chzla1 ads,Ada Characters Wide_Latin_1 a-cwila1 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id4}@anchor{27a}@anchor{gnat_rm/the_gnat_library ada-characters-wide-latin-9-a-cwila1-ads}@anchor{27b} +@section @cite{Ada.Characters.Wide_Latin_9} (@code{a-cwila1.ads}) + + +@geindex Ada.Characters.Wide_Latin_9 (a-cwila1.ads) -@noindent -This child of @code{Ada.Characters} +@geindex Latin_9 constants for Wide_Character + +This child of @cite{Ada.Characters} provides a set of definitions corresponding to those in the -GNAT defined package @code{Ada.Characters.Latin_9} but with the -types of the constants being @code{Wide_Character} -instead of @code{Character}. The provision of such a package +GNAT defined package @cite{Ada.Characters.Latin_9} but with the +types of the constants being @cite{Wide_Character} +instead of @cite{Character}. The provision of such a package is specifically authorized by the Ada Reference Manual (RM A.3.3(27)). -@node Ada.Characters.Wide_Wide_Latin_1 (a-chzla1.ads) -@section @code{Ada.Characters.Wide_Wide_Latin_1} (@file{a-chzla1.ads}) -@cindex @code{Ada.Characters.Wide_Wide_Latin_1} (@file{a-chzla1.ads}) -@cindex Latin_1 constants for Wide_Wide_Character +@node Ada Characters Wide_Wide_Latin_1 a-chzla1 ads,Ada Characters Wide_Wide_Latin_9 a-chzla9 ads,Ada Characters Wide_Latin_9 a-cwila1 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-characters-wide-wide-latin-1-a-chzla1-ads}@anchor{27c}@anchor{gnat_rm/the_gnat_library id5}@anchor{27d} +@section @cite{Ada.Characters.Wide_Wide_Latin_1} (@code{a-chzla1.ads}) + -@noindent -This child of @code{Ada.Characters} +@geindex Ada.Characters.Wide_Wide_Latin_1 (a-chzla1.ads) + +@geindex Latin_1 constants for Wide_Wide_Character + +This child of @cite{Ada.Characters} provides a set of definitions corresponding to those in the -RM-defined package @code{Ada.Characters.Latin_1} but with the -types of the constants being @code{Wide_Wide_Character} -instead of @code{Character}. The provision of such a package +RM-defined package @cite{Ada.Characters.Latin_1} but with the +types of the constants being @cite{Wide_Wide_Character} +instead of @cite{Character}. The provision of such a package is specifically authorized by the Ada Reference Manual (RM A.3.3(27)). -@node Ada.Characters.Wide_Wide_Latin_9 (a-chzla9.ads) -@section @code{Ada.Characters.Wide_Wide_Latin_9} (@file{a-chzla9.ads}) -@cindex @code{Ada.Characters.Wide_Wide_Latin_9} (@file{a-chzla9.ads}) -@cindex Latin_9 constants for Wide_Wide_Character +@node Ada Characters Wide_Wide_Latin_9 a-chzla9 ads,Ada Containers Formal_Doubly_Linked_Lists a-cfdlli ads,Ada Characters Wide_Wide_Latin_1 a-chzla1 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-characters-wide-wide-latin-9-a-chzla9-ads}@anchor{27e}@anchor{gnat_rm/the_gnat_library id6}@anchor{27f} +@section @cite{Ada.Characters.Wide_Wide_Latin_9} (@code{a-chzla9.ads}) + -@noindent -This child of @code{Ada.Characters} +@geindex Ada.Characters.Wide_Wide_Latin_9 (a-chzla9.ads) + +@geindex Latin_9 constants for Wide_Wide_Character + +This child of @cite{Ada.Characters} provides a set of definitions corresponding to those in the -GNAT defined package @code{Ada.Characters.Latin_9} but with the -types of the constants being @code{Wide_Wide_Character} -instead of @code{Character}. The provision of such a package +GNAT defined package @cite{Ada.Characters.Latin_9} but with the +types of the constants being @cite{Wide_Wide_Character} +instead of @cite{Character}. The provision of such a package is specifically authorized by the Ada Reference Manual (RM A.3.3(27)). -@node Ada.Containers.Formal_Doubly_Linked_Lists (a-cfdlli.ads) -@section @code{Ada.Containers.Formal_Doubly_Linked_Lists} (@file{a-cfdlli.ads}) -@cindex @code{Ada.Containers.Formal_Doubly_Linked_Lists} (@file{a-cfdlli.ads}) -@cindex Formal container for doubly linked lists +@node Ada Containers Formal_Doubly_Linked_Lists a-cfdlli ads,Ada Containers Formal_Hashed_Maps a-cfhama ads,Ada Characters Wide_Wide_Latin_9 a-chzla9 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id7}@anchor{280}@anchor{gnat_rm/the_gnat_library ada-containers-formal-doubly-linked-lists-a-cfdlli-ads}@anchor{281} +@section @cite{Ada.Containers.Formal_Doubly_Linked_Lists} (@code{a-cfdlli.ads}) + -@noindent -This child of @code{Ada.Containers} defines a modified version of the +@geindex Ada.Containers.Formal_Doubly_Linked_Lists (a-cfdlli.ads) + +@geindex Formal container for doubly linked lists + +This child of @cite{Ada.Containers} defines a modified version of the Ada 2005 container for doubly linked lists, meant to facilitate formal verification of code using such containers. The specification of this unit is compatible with SPARK 2014. @@ -19268,13 +22004,16 @@ in mind, it may well be generally useful in that it is a simplified more efficient version than the one defined in the standard. In particular it does not have the complex overhead required to detect cursor tampering. -@node Ada.Containers.Formal_Hashed_Maps (a-cfhama.ads) -@section @code{Ada.Containers.Formal_Hashed_Maps} (@file{a-cfhama.ads}) -@cindex @code{Ada.Containers.Formal_Hashed_Maps} (@file{a-cfhama.ads}) -@cindex Formal container for hashed maps +@node Ada Containers Formal_Hashed_Maps a-cfhama ads,Ada Containers Formal_Hashed_Sets a-cfhase ads,Ada Containers Formal_Doubly_Linked_Lists a-cfdlli ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id8}@anchor{282}@anchor{gnat_rm/the_gnat_library ada-containers-formal-hashed-maps-a-cfhama-ads}@anchor{283} +@section @cite{Ada.Containers.Formal_Hashed_Maps} (@code{a-cfhama.ads}) + -@noindent -This child of @code{Ada.Containers} defines a modified version of the +@geindex Ada.Containers.Formal_Hashed_Maps (a-cfhama.ads) + +@geindex Formal container for hashed maps + +This child of @cite{Ada.Containers} defines a modified version of the Ada 2005 container for hashed maps, meant to facilitate formal verification of code using such containers. The specification of this unit is compatible with SPARK 2014. @@ -19284,13 +22023,16 @@ in mind, it may well be generally useful in that it is a simplified more efficient version than the one defined in the standard. In particular it does not have the complex overhead required to detect cursor tampering. -@node Ada.Containers.Formal_Hashed_Sets (a-cfhase.ads) -@section @code{Ada.Containers.Formal_Hashed_Sets} (@file{a-cfhase.ads}) -@cindex @code{Ada.Containers.Formal_Hashed_Sets} (@file{a-cfhase.ads}) -@cindex Formal container for hashed sets +@node Ada Containers Formal_Hashed_Sets a-cfhase ads,Ada Containers Formal_Ordered_Maps a-cforma ads,Ada Containers Formal_Hashed_Maps a-cfhama ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id9}@anchor{284}@anchor{gnat_rm/the_gnat_library ada-containers-formal-hashed-sets-a-cfhase-ads}@anchor{285} +@section @cite{Ada.Containers.Formal_Hashed_Sets} (@code{a-cfhase.ads}) + -@noindent -This child of @code{Ada.Containers} defines a modified version of the +@geindex Ada.Containers.Formal_Hashed_Sets (a-cfhase.ads) + +@geindex Formal container for hashed sets + +This child of @cite{Ada.Containers} defines a modified version of the Ada 2005 container for hashed sets, meant to facilitate formal verification of code using such containers. The specification of this unit is compatible with SPARK 2014. @@ -19300,13 +22042,16 @@ in mind, it may well be generally useful in that it is a simplified more efficient version than the one defined in the standard. In particular it does not have the complex overhead required to detect cursor tampering. -@node Ada.Containers.Formal_Ordered_Maps (a-cforma.ads) -@section @code{Ada.Containers.Formal_Ordered_Maps} (@file{a-cforma.ads}) -@cindex @code{Ada.Containers.Formal_Ordered_Maps} (@file{a-cforma.ads}) -@cindex Formal container for ordered maps +@node Ada Containers Formal_Ordered_Maps a-cforma ads,Ada Containers Formal_Ordered_Sets a-cforse ads,Ada Containers Formal_Hashed_Sets a-cfhase ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id10}@anchor{286}@anchor{gnat_rm/the_gnat_library ada-containers-formal-ordered-maps-a-cforma-ads}@anchor{287} +@section @cite{Ada.Containers.Formal_Ordered_Maps} (@code{a-cforma.ads}) + -@noindent -This child of @code{Ada.Containers} defines a modified version of the +@geindex Ada.Containers.Formal_Ordered_Maps (a-cforma.ads) + +@geindex Formal container for ordered maps + +This child of @cite{Ada.Containers} defines a modified version of the Ada 2005 container for ordered maps, meant to facilitate formal verification of code using such containers. The specification of this unit is compatible with SPARK 2014. @@ -19316,13 +22061,16 @@ in mind, it may well be generally useful in that it is a simplified more efficient version than the one defined in the standard. In particular it does not have the complex overhead required to detect cursor tampering. -@node Ada.Containers.Formal_Ordered_Sets (a-cforse.ads) -@section @code{Ada.Containers.Formal_Ordered_Sets} (@file{a-cforse.ads}) -@cindex @code{Ada.Containers.Formal_Ordered_Sets} (@file{a-cforse.ads}) -@cindex Formal container for ordered sets +@node Ada Containers Formal_Ordered_Sets a-cforse ads,Ada Containers Formal_Vectors a-cofove ads,Ada Containers Formal_Ordered_Maps a-cforma ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-containers-formal-ordered-sets-a-cforse-ads}@anchor{288}@anchor{gnat_rm/the_gnat_library id11}@anchor{289} +@section @cite{Ada.Containers.Formal_Ordered_Sets} (@code{a-cforse.ads}) + -@noindent -This child of @code{Ada.Containers} defines a modified version of the +@geindex Ada.Containers.Formal_Ordered_Sets (a-cforse.ads) + +@geindex Formal container for ordered sets + +This child of @cite{Ada.Containers} defines a modified version of the Ada 2005 container for ordered sets, meant to facilitate formal verification of code using such containers. The specification of this unit is compatible with SPARK 2014. @@ -19332,13 +22080,16 @@ in mind, it may well be generally useful in that it is a simplified more efficient version than the one defined in the standard. In particular it does not have the complex overhead required to detect cursor tampering. -@node Ada.Containers.Formal_Vectors (a-cofove.ads) -@section @code{Ada.Containers.Formal_Vectors} (@file{a-cofove.ads}) -@cindex @code{Ada.Containers.Formal_Vectors} (@file{a-cofove.ads}) -@cindex Formal container for vectors +@node Ada Containers Formal_Vectors a-cofove ads,Ada Containers Formal_Indefinite_Vectors a-cfinve ads,Ada Containers Formal_Ordered_Sets a-cforse ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id12}@anchor{28a}@anchor{gnat_rm/the_gnat_library ada-containers-formal-vectors-a-cofove-ads}@anchor{28b} +@section @cite{Ada.Containers.Formal_Vectors} (@code{a-cofove.ads}) + + +@geindex Ada.Containers.Formal_Vectors (a-cofove.ads) + +@geindex Formal container for vectors -@noindent -This child of @code{Ada.Containers} defines a modified version of the +This child of @cite{Ada.Containers} defines a modified version of the Ada 2005 container for vectors, meant to facilitate formal verification of code using such containers. The specification of this unit is compatible with SPARK 2014. @@ -19348,13 +22099,16 @@ in mind, it may well be generally useful in that it is a simplified more efficient version than the one defined in the standard. In particular it does not have the complex overhead required to detect cursor tampering. -@node Ada.Containers.Formal_Indefinite_Vectors (a-cfinve.ads) -@section @code{Ada.Containers.Formal_Indefinite_Vectors} (@file{a-cfinve.ads}) -@cindex @code{Ada.Containers.Formal_Indefinite_Vectors} (@file{a-cfinve.ads}) -@cindex Formal container for vectors +@node Ada Containers Formal_Indefinite_Vectors a-cfinve ads,Ada Containers Bounded_Holders a-coboho ads,Ada Containers Formal_Vectors a-cofove ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id13}@anchor{28c}@anchor{gnat_rm/the_gnat_library ada-containers-formal-indefinite-vectors-a-cfinve-ads}@anchor{28d} +@section @cite{Ada.Containers.Formal_Indefinite_Vectors} (@code{a-cfinve.ads}) -@noindent -This child of @code{Ada.Containers} defines a modified version of the + +@geindex Ada.Containers.Formal_Indefinite_Vectors (a-cfinve.ads) + +@geindex Formal container for vectors + +This child of @cite{Ada.Containers} defines a modified version of the Ada 2005 container for vectors of indefinite elements, meant to facilitate formal verification of code using such containers. The specification of this unit is compatible with SPARK 2014. @@ -19364,531 +22118,725 @@ in mind, it may well be generally useful in that it is a simplified more efficient version than the one defined in the standard. In particular it does not have the complex overhead required to detect cursor tampering. -@node Ada.Containers.Bounded_Holders (a-coboho.ads) -@section @code{Ada.Containers.Bounded_Holders} (@file{a-coboho.ads}) -@cindex @code{Ada.Containers.Bounded_Holders} (@file{a-coboho.ads}) -@cindex Formal container for vectors +@node Ada Containers Bounded_Holders a-coboho ads,Ada Command_Line Environment a-colien ads,Ada Containers Formal_Indefinite_Vectors a-cfinve ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id14}@anchor{28e}@anchor{gnat_rm/the_gnat_library ada-containers-bounded-holders-a-coboho-ads}@anchor{28f} +@section @cite{Ada.Containers.Bounded_Holders} (@code{a-coboho.ads}) + + +@geindex Ada.Containers.Bounded_Holders (a-coboho.ads) + +@geindex Formal container for vectors -@noindent -This child of @code{Ada.Containers} defines a modified version of +This child of @cite{Ada.Containers} defines a modified version of Indefinite_Holders that avoids heap allocation. -@node Ada.Command_Line.Environment (a-colien.ads) -@section @code{Ada.Command_Line.Environment} (@file{a-colien.ads}) -@cindex @code{Ada.Command_Line.Environment} (@file{a-colien.ads}) -@cindex Environment entries +@node Ada Command_Line Environment a-colien ads,Ada Command_Line Remove a-colire ads,Ada Containers Bounded_Holders a-coboho ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-command-line-environment-a-colien-ads}@anchor{290}@anchor{gnat_rm/the_gnat_library id15}@anchor{291} +@section @cite{Ada.Command_Line.Environment} (@code{a-colien.ads}) -@noindent -This child of @code{Ada.Command_Line} + +@geindex Ada.Command_Line.Environment (a-colien.ads) + +@geindex Environment entries + +This child of @cite{Ada.Command_Line} provides a mechanism for obtaining environment values on systems where this concept makes sense. -@node Ada.Command_Line.Remove (a-colire.ads) -@section @code{Ada.Command_Line.Remove} (@file{a-colire.ads}) -@cindex @code{Ada.Command_Line.Remove} (@file{a-colire.ads}) -@cindex Removing command line arguments -@cindex Command line, argument removal +@node Ada Command_Line Remove a-colire ads,Ada Command_Line Response_File a-clrefi ads,Ada Command_Line Environment a-colien ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id16}@anchor{292}@anchor{gnat_rm/the_gnat_library ada-command-line-remove-a-colire-ads}@anchor{293} +@section @cite{Ada.Command_Line.Remove} (@code{a-colire.ads}) + + +@geindex Ada.Command_Line.Remove (a-colire.ads) + +@geindex Removing command line arguments -@noindent -This child of @code{Ada.Command_Line} +@geindex Command line +@geindex argument removal + +This child of @cite{Ada.Command_Line} provides a mechanism for logically removing arguments from the argument list. Once removed, an argument is not visible -to further calls on the subprograms in @code{Ada.Command_Line} will not +to further calls on the subprograms in @cite{Ada.Command_Line} will not see the removed argument. -@node Ada.Command_Line.Response_File (a-clrefi.ads) -@section @code{Ada.Command_Line.Response_File} (@file{a-clrefi.ads}) -@cindex @code{Ada.Command_Line.Response_File} (@file{a-clrefi.ads}) -@cindex Response file for command line -@cindex Command line, response file -@cindex Command line, handling long command lines +@node Ada Command_Line Response_File a-clrefi ads,Ada Direct_IO C_Streams a-diocst ads,Ada Command_Line Remove a-colire ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-command-line-response-file-a-clrefi-ads}@anchor{294}@anchor{gnat_rm/the_gnat_library id17}@anchor{295} +@section @cite{Ada.Command_Line.Response_File} (@code{a-clrefi.ads}) + + +@geindex Ada.Command_Line.Response_File (a-clrefi.ads) + +@geindex Response file for command line + +@geindex Command line +@geindex response file + +@geindex Command line +@geindex handling long command lines -@noindent -This child of @code{Ada.Command_Line} provides a mechanism facilities for +This child of @cite{Ada.Command_Line} provides a mechanism facilities for getting command line arguments from a text file, called a "response file". Using a response file allow passing a set of arguments to an executable longer than the maximum allowed by the system on the command line. -@node Ada.Direct_IO.C_Streams (a-diocst.ads) -@section @code{Ada.Direct_IO.C_Streams} (@file{a-diocst.ads}) -@cindex @code{Ada.Direct_IO.C_Streams} (@file{a-diocst.ads}) -@cindex C Streams, Interfacing with Direct_IO +@node Ada Direct_IO C_Streams a-diocst ads,Ada Exceptions Is_Null_Occurrence a-einuoc ads,Ada Command_Line Response_File a-clrefi ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id18}@anchor{296}@anchor{gnat_rm/the_gnat_library ada-direct-io-c-streams-a-diocst-ads}@anchor{297} +@section @cite{Ada.Direct_IO.C_Streams} (@code{a-diocst.ads}) + + +@geindex Ada.Direct_IO.C_Streams (a-diocst.ads) + +@geindex C Streams +@geindex Interfacing with Direct_IO -@noindent This package provides subprograms that allow interfacing between -C streams and @code{Direct_IO}. The stream identifier can be +C streams and @cite{Direct_IO}. The stream identifier can be extracted from a file opened on the Ada side, and an Ada file can be constructed from a stream opened on the C side. -@node Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads) -@section @code{Ada.Exceptions.Is_Null_Occurrence} (@file{a-einuoc.ads}) -@cindex @code{Ada.Exceptions.Is_Null_Occurrence} (@file{a-einuoc.ads}) -@cindex Null_Occurrence, testing for +@node Ada Exceptions Is_Null_Occurrence a-einuoc ads,Ada Exceptions Last_Chance_Handler a-elchha ads,Ada Direct_IO C_Streams a-diocst ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id19}@anchor{298}@anchor{gnat_rm/the_gnat_library ada-exceptions-is-null-occurrence-a-einuoc-ads}@anchor{299} +@section @cite{Ada.Exceptions.Is_Null_Occurrence} (@code{a-einuoc.ads}) + + +@geindex Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads) + +@geindex Null_Occurrence +@geindex testing for -@noindent This child subprogram provides a way of testing for the null -exception occurrence (@code{Null_Occurrence}) without raising +exception occurrence (@cite{Null_Occurrence}) without raising an exception. -@node Ada.Exceptions.Last_Chance_Handler (a-elchha.ads) -@section @code{Ada.Exceptions.Last_Chance_Handler} (@file{a-elchha.ads}) -@cindex @code{Ada.Exceptions.Last_Chance_Handler} (@file{a-elchha.ads}) -@cindex Null_Occurrence, testing for +@node Ada Exceptions Last_Chance_Handler a-elchha ads,Ada Exceptions Traceback a-exctra ads,Ada Exceptions Is_Null_Occurrence a-einuoc ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id20}@anchor{29a}@anchor{gnat_rm/the_gnat_library ada-exceptions-last-chance-handler-a-elchha-ads}@anchor{29b} +@section @cite{Ada.Exceptions.Last_Chance_Handler} (@code{a-elchha.ads}) + + +@geindex Ada.Exceptions.Last_Chance_Handler (a-elchha.ads) + +@geindex Null_Occurrence +@geindex testing for -@noindent This child subprogram is used for handling otherwise unhandled exceptions (hence the name last chance), and perform clean ups before terminating the program. Note that this subprogram never returns. -@node Ada.Exceptions.Traceback (a-exctra.ads) -@section @code{Ada.Exceptions.Traceback} (@file{a-exctra.ads}) -@cindex @code{Ada.Exceptions.Traceback} (@file{a-exctra.ads}) -@cindex Traceback for Exception Occurrence +@node Ada Exceptions Traceback a-exctra ads,Ada Sequential_IO C_Streams a-siocst ads,Ada Exceptions Last_Chance_Handler a-elchha ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-exceptions-traceback-a-exctra-ads}@anchor{29c}@anchor{gnat_rm/the_gnat_library id21}@anchor{29d} +@section @cite{Ada.Exceptions.Traceback} (@code{a-exctra.ads}) + + +@geindex Ada.Exceptions.Traceback (a-exctra.ads) -@noindent -This child package provides the subprogram (@code{Tracebacks}) to +@geindex Traceback for Exception Occurrence + +This child package provides the subprogram (@cite{Tracebacks}) to give a traceback array of addresses based on an exception occurrence. -@node Ada.Sequential_IO.C_Streams (a-siocst.ads) -@section @code{Ada.Sequential_IO.C_Streams} (@file{a-siocst.ads}) -@cindex @code{Ada.Sequential_IO.C_Streams} (@file{a-siocst.ads}) -@cindex C Streams, Interfacing with Sequential_IO +@node Ada Sequential_IO C_Streams a-siocst ads,Ada Streams Stream_IO C_Streams a-ssicst ads,Ada Exceptions Traceback a-exctra ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-sequential-io-c-streams-a-siocst-ads}@anchor{29e}@anchor{gnat_rm/the_gnat_library id22}@anchor{29f} +@section @cite{Ada.Sequential_IO.C_Streams} (@code{a-siocst.ads}) + + +@geindex Ada.Sequential_IO.C_Streams (a-siocst.ads) + +@geindex C Streams +@geindex Interfacing with Sequential_IO -@noindent This package provides subprograms that allow interfacing between -C streams and @code{Sequential_IO}. The stream identifier can be +C streams and @cite{Sequential_IO}. The stream identifier can be extracted from a file opened on the Ada side, and an Ada file can be constructed from a stream opened on the C side. -@node Ada.Streams.Stream_IO.C_Streams (a-ssicst.ads) -@section @code{Ada.Streams.Stream_IO.C_Streams} (@file{a-ssicst.ads}) -@cindex @code{Ada.Streams.Stream_IO.C_Streams} (@file{a-ssicst.ads}) -@cindex C Streams, Interfacing with Stream_IO +@node Ada Streams Stream_IO C_Streams a-ssicst ads,Ada Strings Unbounded Text_IO a-suteio ads,Ada Sequential_IO C_Streams a-siocst ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id23}@anchor{2a0}@anchor{gnat_rm/the_gnat_library ada-streams-stream-io-c-streams-a-ssicst-ads}@anchor{2a1} +@section @cite{Ada.Streams.Stream_IO.C_Streams} (@code{a-ssicst.ads}) + + +@geindex Ada.Streams.Stream_IO.C_Streams (a-ssicst.ads) + +@geindex C Streams +@geindex Interfacing with Stream_IO -@noindent This package provides subprograms that allow interfacing between -C streams and @code{Stream_IO}. The stream identifier can be +C streams and @cite{Stream_IO}. The stream identifier can be extracted from a file opened on the Ada side, and an Ada file can be constructed from a stream opened on the C side. -@node Ada.Strings.Unbounded.Text_IO (a-suteio.ads) -@section @code{Ada.Strings.Unbounded.Text_IO} (@file{a-suteio.ads}) -@cindex @code{Ada.Strings.Unbounded.Text_IO} (@file{a-suteio.ads}) -@cindex @code{Unbounded_String}, IO support -@cindex @code{Text_IO}, extensions for unbounded strings +@node Ada Strings Unbounded Text_IO a-suteio ads,Ada Strings Wide_Unbounded Wide_Text_IO a-swuwti ads,Ada Streams Stream_IO C_Streams a-ssicst ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-strings-unbounded-text-io-a-suteio-ads}@anchor{2a2}@anchor{gnat_rm/the_gnat_library id24}@anchor{2a3} +@section @cite{Ada.Strings.Unbounded.Text_IO} (@code{a-suteio.ads}) + + +@geindex Ada.Strings.Unbounded.Text_IO (a-suteio.ads) + +@geindex Unbounded_String +@geindex IO support + +@geindex Text_IO +@geindex extensions for unbounded strings -@noindent This package provides subprograms for Text_IO for unbounded strings, avoiding the necessity for an intermediate operation with ordinary strings. -@node Ada.Strings.Wide_Unbounded.Wide_Text_IO (a-swuwti.ads) -@section @code{Ada.Strings.Wide_Unbounded.Wide_Text_IO} (@file{a-swuwti.ads}) -@cindex @code{Ada.Strings.Wide_Unbounded.Wide_Text_IO} (@file{a-swuwti.ads}) -@cindex @code{Unbounded_Wide_String}, IO support -@cindex @code{Text_IO}, extensions for unbounded wide strings +@node Ada Strings Wide_Unbounded Wide_Text_IO a-swuwti ads,Ada Strings Wide_Wide_Unbounded Wide_Wide_Text_IO a-szuzti ads,Ada Strings Unbounded Text_IO a-suteio ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id25}@anchor{2a4}@anchor{gnat_rm/the_gnat_library ada-strings-wide-unbounded-wide-text-io-a-swuwti-ads}@anchor{2a5} +@section @cite{Ada.Strings.Wide_Unbounded.Wide_Text_IO} (@code{a-swuwti.ads}) + + +@geindex Ada.Strings.Wide_Unbounded.Wide_Text_IO (a-swuwti.ads) + +@geindex Unbounded_Wide_String +@geindex IO support + +@geindex Text_IO +@geindex extensions for unbounded wide strings -@noindent This package provides subprograms for Text_IO for unbounded wide strings, avoiding the necessity for an intermediate operation with ordinary wide strings. -@node Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO (a-szuzti.ads) -@section @code{Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO} (@file{a-szuzti.ads}) -@cindex @code{Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO} (@file{a-szuzti.ads}) -@cindex @code{Unbounded_Wide_Wide_String}, IO support -@cindex @code{Text_IO}, extensions for unbounded wide wide strings +@node Ada Strings Wide_Wide_Unbounded Wide_Wide_Text_IO a-szuzti ads,Ada Text_IO C_Streams a-tiocst ads,Ada Strings Wide_Unbounded Wide_Text_IO a-swuwti ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-strings-wide-wide-unbounded-wide-wide-text-io-a-szuzti-ads}@anchor{2a6}@anchor{gnat_rm/the_gnat_library id26}@anchor{2a7} +@section @cite{Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO} (@code{a-szuzti.ads}) + + +@geindex Ada.Strings.Wide_Wide_Unbounded.Wide_Wide_Text_IO (a-szuzti.ads) + +@geindex Unbounded_Wide_Wide_String +@geindex IO support + +@geindex Text_IO +@geindex extensions for unbounded wide wide strings -@noindent This package provides subprograms for Text_IO for unbounded wide wide strings, avoiding the necessity for an intermediate operation with ordinary wide wide strings. -@node Ada.Text_IO.C_Streams (a-tiocst.ads) -@section @code{Ada.Text_IO.C_Streams} (@file{a-tiocst.ads}) -@cindex @code{Ada.Text_IO.C_Streams} (@file{a-tiocst.ads}) -@cindex C Streams, Interfacing with @code{Text_IO} +@node Ada Text_IO C_Streams a-tiocst ads,Ada Text_IO Reset_Standard_Files a-tirsfi ads,Ada Strings Wide_Wide_Unbounded Wide_Wide_Text_IO a-szuzti ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-text-io-c-streams-a-tiocst-ads}@anchor{2a8}@anchor{gnat_rm/the_gnat_library id27}@anchor{2a9} +@section @cite{Ada.Text_IO.C_Streams} (@code{a-tiocst.ads}) + + +@geindex Ada.Text_IO.C_Streams (a-tiocst.ads) + +@geindex C Streams +@geindex Interfacing with `Text_IO` -@noindent This package provides subprograms that allow interfacing between -C streams and @code{Text_IO}. The stream identifier can be +C streams and @cite{Text_IO}. The stream identifier can be extracted from a file opened on the Ada side, and an Ada file can be constructed from a stream opened on the C side. -@node Ada.Text_IO.Reset_Standard_Files (a-tirsfi.ads) -@section @code{Ada.Text_IO.Reset_Standard_Files} (@file{a-tirsfi.ads}) -@cindex @code{Ada.Text_IO.Reset_Standard_Files} (@file{a-tirsfi.ads}) -@cindex @code{Text_IO} resetting standard files +@node Ada Text_IO Reset_Standard_Files a-tirsfi ads,Ada Wide_Characters Unicode a-wichun ads,Ada Text_IO C_Streams a-tiocst ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id28}@anchor{2aa}@anchor{gnat_rm/the_gnat_library ada-text-io-reset-standard-files-a-tirsfi-ads}@anchor{2ab} +@section @cite{Ada.Text_IO.Reset_Standard_Files} (@code{a-tirsfi.ads}) + + +@geindex Ada.Text_IO.Reset_Standard_Files (a-tirsfi.ads) + +@geindex Text_IO resetting standard files -@noindent This procedure is used to reset the status of the standard files used by Ada.Text_IO. This is useful in a situation (such as a restart in an embedded application) where the status of the files may change during execution (for example a standard input file may be redefined to be interactive). -@node Ada.Wide_Characters.Unicode (a-wichun.ads) -@section @code{Ada.Wide_Characters.Unicode} (@file{a-wichun.ads}) -@cindex @code{Ada.Wide_Characters.Unicode} (@file{a-wichun.ads}) -@cindex Unicode categorization, Wide_Character +@node Ada Wide_Characters Unicode a-wichun ads,Ada Wide_Text_IO C_Streams a-wtcstr ads,Ada Text_IO Reset_Standard_Files a-tirsfi ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id29}@anchor{2ac}@anchor{gnat_rm/the_gnat_library ada-wide-characters-unicode-a-wichun-ads}@anchor{2ad} +@section @cite{Ada.Wide_Characters.Unicode} (@code{a-wichun.ads}) + + +@geindex Ada.Wide_Characters.Unicode (a-wichun.ads) + +@geindex Unicode categorization +@geindex Wide_Character -@noindent This package provides subprograms that allow categorization of Wide_Character values according to Unicode categories. -@node Ada.Wide_Text_IO.C_Streams (a-wtcstr.ads) -@section @code{Ada.Wide_Text_IO.C_Streams} (@file{a-wtcstr.ads}) -@cindex @code{Ada.Wide_Text_IO.C_Streams} (@file{a-wtcstr.ads}) -@cindex C Streams, Interfacing with @code{Wide_Text_IO} +@node Ada Wide_Text_IO C_Streams a-wtcstr ads,Ada Wide_Text_IO Reset_Standard_Files a-wrstfi ads,Ada Wide_Characters Unicode a-wichun ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-wide-text-io-c-streams-a-wtcstr-ads}@anchor{2ae}@anchor{gnat_rm/the_gnat_library id30}@anchor{2af} +@section @cite{Ada.Wide_Text_IO.C_Streams} (@code{a-wtcstr.ads}) + + +@geindex Ada.Wide_Text_IO.C_Streams (a-wtcstr.ads) + +@geindex C Streams +@geindex Interfacing with `Wide_Text_IO` -@noindent This package provides subprograms that allow interfacing between -C streams and @code{Wide_Text_IO}. The stream identifier can be +C streams and @cite{Wide_Text_IO}. The stream identifier can be extracted from a file opened on the Ada side, and an Ada file can be constructed from a stream opened on the C side. -@node Ada.Wide_Text_IO.Reset_Standard_Files (a-wrstfi.ads) -@section @code{Ada.Wide_Text_IO.Reset_Standard_Files} (@file{a-wrstfi.ads}) -@cindex @code{Ada.Wide_Text_IO.Reset_Standard_Files} (@file{a-wrstfi.ads}) -@cindex @code{Wide_Text_IO} resetting standard files +@node Ada Wide_Text_IO Reset_Standard_Files a-wrstfi ads,Ada Wide_Wide_Characters Unicode a-zchuni ads,Ada Wide_Text_IO C_Streams a-wtcstr ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library ada-wide-text-io-reset-standard-files-a-wrstfi-ads}@anchor{2b0}@anchor{gnat_rm/the_gnat_library id31}@anchor{2b1} +@section @cite{Ada.Wide_Text_IO.Reset_Standard_Files} (@code{a-wrstfi.ads}) + + +@geindex Ada.Wide_Text_IO.Reset_Standard_Files (a-wrstfi.ads) + +@geindex Wide_Text_IO resetting standard files -@noindent This procedure is used to reset the status of the standard files used by Ada.Wide_Text_IO. This is useful in a situation (such as a restart in an embedded application) where the status of the files may change during execution (for example a standard input file may be redefined to be interactive). -@node Ada.Wide_Wide_Characters.Unicode (a-zchuni.ads) -@section @code{Ada.Wide_Wide_Characters.Unicode} (@file{a-zchuni.ads}) -@cindex @code{Ada.Wide_Wide_Characters.Unicode} (@file{a-zchuni.ads}) -@cindex Unicode categorization, Wide_Wide_Character +@node Ada Wide_Wide_Characters Unicode a-zchuni ads,Ada Wide_Wide_Text_IO C_Streams a-ztcstr ads,Ada Wide_Text_IO Reset_Standard_Files a-wrstfi ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id32}@anchor{2b2}@anchor{gnat_rm/the_gnat_library ada-wide-wide-characters-unicode-a-zchuni-ads}@anchor{2b3} +@section @cite{Ada.Wide_Wide_Characters.Unicode} (@code{a-zchuni.ads}) + + +@geindex Ada.Wide_Wide_Characters.Unicode (a-zchuni.ads) + +@geindex Unicode categorization +@geindex Wide_Wide_Character -@noindent This package provides subprograms that allow categorization of Wide_Wide_Character values according to Unicode categories. -@node Ada.Wide_Wide_Text_IO.C_Streams (a-ztcstr.ads) -@section @code{Ada.Wide_Wide_Text_IO.C_Streams} (@file{a-ztcstr.ads}) -@cindex @code{Ada.Wide_Wide_Text_IO.C_Streams} (@file{a-ztcstr.ads}) -@cindex C Streams, Interfacing with @code{Wide_Wide_Text_IO} +@node Ada Wide_Wide_Text_IO C_Streams a-ztcstr ads,Ada Wide_Wide_Text_IO Reset_Standard_Files a-zrstfi ads,Ada Wide_Wide_Characters Unicode a-zchuni ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id33}@anchor{2b4}@anchor{gnat_rm/the_gnat_library ada-wide-wide-text-io-c-streams-a-ztcstr-ads}@anchor{2b5} +@section @cite{Ada.Wide_Wide_Text_IO.C_Streams} (@code{a-ztcstr.ads}) + + +@geindex Ada.Wide_Wide_Text_IO.C_Streams (a-ztcstr.ads) + +@geindex C Streams +@geindex Interfacing with `Wide_Wide_Text_IO` -@noindent This package provides subprograms that allow interfacing between -C streams and @code{Wide_Wide_Text_IO}. The stream identifier can be +C streams and @cite{Wide_Wide_Text_IO}. The stream identifier can be extracted from a file opened on the Ada side, and an Ada file can be constructed from a stream opened on the C side. -@node Ada.Wide_Wide_Text_IO.Reset_Standard_Files (a-zrstfi.ads) -@section @code{Ada.Wide_Wide_Text_IO.Reset_Standard_Files} (@file{a-zrstfi.ads}) -@cindex @code{Ada.Wide_Wide_Text_IO.Reset_Standard_Files} (@file{a-zrstfi.ads}) -@cindex @code{Wide_Wide_Text_IO} resetting standard files +@node Ada Wide_Wide_Text_IO Reset_Standard_Files a-zrstfi ads,GNAT Altivec g-altive ads,Ada Wide_Wide_Text_IO C_Streams a-ztcstr ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id34}@anchor{2b6}@anchor{gnat_rm/the_gnat_library ada-wide-wide-text-io-reset-standard-files-a-zrstfi-ads}@anchor{2b7} +@section @cite{Ada.Wide_Wide_Text_IO.Reset_Standard_Files} (@code{a-zrstfi.ads}) + + +@geindex Ada.Wide_Wide_Text_IO.Reset_Standard_Files (a-zrstfi.ads) + +@geindex Wide_Wide_Text_IO resetting standard files -@noindent This procedure is used to reset the status of the standard files used by Ada.Wide_Wide_Text_IO. This is useful in a situation (such as a restart in an embedded application) where the status of the files may change during execution (for example a standard input file may be redefined to be interactive). -@node GNAT.Altivec (g-altive.ads) -@section @code{GNAT.Altivec} (@file{g-altive.ads}) -@cindex @code{GNAT.Altivec} (@file{g-altive.ads}) -@cindex AltiVec +@node GNAT Altivec g-altive ads,GNAT Altivec Conversions g-altcon ads,Ada Wide_Wide_Text_IO Reset_Standard_Files a-zrstfi ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-altivec-g-altive-ads}@anchor{2b8}@anchor{gnat_rm/the_gnat_library id35}@anchor{2b9} +@section @cite{GNAT.Altivec} (@code{g-altive.ads}) + + +@geindex GNAT.Altivec (g-altive.ads) + +@geindex AltiVec -@noindent This is the root package of the GNAT AltiVec binding. It provides definitions of constants and types common to all the versions of the binding. -@node GNAT.Altivec.Conversions (g-altcon.ads) -@section @code{GNAT.Altivec.Conversions} (@file{g-altcon.ads}) -@cindex @code{GNAT.Altivec.Conversions} (@file{g-altcon.ads}) -@cindex AltiVec +@node GNAT Altivec Conversions g-altcon ads,GNAT Altivec Vector_Operations g-alveop ads,GNAT Altivec g-altive ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id36}@anchor{2ba}@anchor{gnat_rm/the_gnat_library gnat-altivec-conversions-g-altcon-ads}@anchor{2bb} +@section @cite{GNAT.Altivec.Conversions} (@code{g-altcon.ads}) + + +@geindex GNAT.Altivec.Conversions (g-altcon.ads) + +@geindex AltiVec -@noindent This package provides the Vector/View conversion routines. -@node GNAT.Altivec.Vector_Operations (g-alveop.ads) -@section @code{GNAT.Altivec.Vector_Operations} (@file{g-alveop.ads}) -@cindex @code{GNAT.Altivec.Vector_Operations} (@file{g-alveop.ads}) -@cindex AltiVec +@node GNAT Altivec Vector_Operations g-alveop ads,GNAT Altivec Vector_Types g-alvety ads,GNAT Altivec Conversions g-altcon ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id37}@anchor{2bc}@anchor{gnat_rm/the_gnat_library gnat-altivec-vector-operations-g-alveop-ads}@anchor{2bd} +@section @cite{GNAT.Altivec.Vector_Operations} (@code{g-alveop.ads}) + + +@geindex GNAT.Altivec.Vector_Operations (g-alveop.ads) + +@geindex AltiVec -@noindent This package exposes the Ada interface to the AltiVec operations on vector objects. A soft emulation is included by default in the GNAT library. The hard binding is provided as a separate package. This unit is common to both bindings. -@node GNAT.Altivec.Vector_Types (g-alvety.ads) -@section @code{GNAT.Altivec.Vector_Types} (@file{g-alvety.ads}) -@cindex @code{GNAT.Altivec.Vector_Types} (@file{g-alvety.ads}) -@cindex AltiVec +@node GNAT Altivec Vector_Types g-alvety ads,GNAT Altivec Vector_Views g-alvevi ads,GNAT Altivec Vector_Operations g-alveop ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-altivec-vector-types-g-alvety-ads}@anchor{2be}@anchor{gnat_rm/the_gnat_library id38}@anchor{2bf} +@section @cite{GNAT.Altivec.Vector_Types} (@code{g-alvety.ads}) + + +@geindex GNAT.Altivec.Vector_Types (g-alvety.ads) + +@geindex AltiVec -@noindent This package exposes the various vector types part of the Ada binding to AltiVec facilities. -@node GNAT.Altivec.Vector_Views (g-alvevi.ads) -@section @code{GNAT.Altivec.Vector_Views} (@file{g-alvevi.ads}) -@cindex @code{GNAT.Altivec.Vector_Views} (@file{g-alvevi.ads}) -@cindex AltiVec +@node GNAT Altivec Vector_Views g-alvevi ads,GNAT Array_Split g-arrspl ads,GNAT Altivec Vector_Types g-alvety ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-altivec-vector-views-g-alvevi-ads}@anchor{2c0}@anchor{gnat_rm/the_gnat_library id39}@anchor{2c1} +@section @cite{GNAT.Altivec.Vector_Views} (@code{g-alvevi.ads}) + + +@geindex GNAT.Altivec.Vector_Views (g-alvevi.ads) + +@geindex AltiVec -@noindent This package provides public 'View' data types from/to which private vector representations can be converted via GNAT.Altivec.Conversions. This allows convenient access to individual vector elements and provides a simple way to initialize vector objects. -@node GNAT.Array_Split (g-arrspl.ads) -@section @code{GNAT.Array_Split} (@file{g-arrspl.ads}) -@cindex @code{GNAT.Array_Split} (@file{g-arrspl.ads}) -@cindex Array splitter +@node GNAT Array_Split g-arrspl ads,GNAT AWK g-awk ads,GNAT Altivec Vector_Views g-alvevi ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-array-split-g-arrspl-ads}@anchor{2c2}@anchor{gnat_rm/the_gnat_library id40}@anchor{2c3} +@section @cite{GNAT.Array_Split} (@code{g-arrspl.ads}) + + +@geindex GNAT.Array_Split (g-arrspl.ads) + +@geindex Array splitter -@noindent Useful array-manipulation routines: given a set of separators, split an array wherever the separators appear, and provide direct access to the resulting slices. -@node GNAT.AWK (g-awk.ads) -@section @code{GNAT.AWK} (@file{g-awk.ads}) -@cindex @code{GNAT.AWK} (@file{g-awk.ads}) -@cindex Parsing -@cindex AWK +@node GNAT AWK g-awk ads,GNAT Bounded_Buffers g-boubuf ads,GNAT Array_Split g-arrspl ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id41}@anchor{2c4}@anchor{gnat_rm/the_gnat_library gnat-awk-g-awk-ads}@anchor{2c5} +@section @cite{GNAT.AWK} (@code{g-awk.ads}) + + +@geindex GNAT.AWK (g-awk.ads) + +@geindex Parsing + +@geindex AWK -@noindent Provides AWK-like parsing functions, with an easy interface for parsing one or more files containing formatted data. The file is viewed as a database where each record is a line and a field is a data element in this line. -@node GNAT.Bounded_Buffers (g-boubuf.ads) -@section @code{GNAT.Bounded_Buffers} (@file{g-boubuf.ads}) -@cindex @code{GNAT.Bounded_Buffers} (@file{g-boubuf.ads}) -@cindex Parsing -@cindex Bounded Buffers +@node GNAT Bounded_Buffers g-boubuf ads,GNAT Bounded_Mailboxes g-boumai ads,GNAT AWK g-awk ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-bounded-buffers-g-boubuf-ads}@anchor{2c6}@anchor{gnat_rm/the_gnat_library id42}@anchor{2c7} +@section @cite{GNAT.Bounded_Buffers} (@code{g-boubuf.ads}) + + +@geindex GNAT.Bounded_Buffers (g-boubuf.ads) + +@geindex Parsing + +@geindex Bounded Buffers -@noindent Provides a concurrent generic bounded buffer abstraction. Instances are useful directly or as parts of the implementations of other abstractions, such as mailboxes. -@node GNAT.Bounded_Mailboxes (g-boumai.ads) -@section @code{GNAT.Bounded_Mailboxes} (@file{g-boumai.ads}) -@cindex @code{GNAT.Bounded_Mailboxes} (@file{g-boumai.ads}) -@cindex Parsing -@cindex Mailboxes +@node GNAT Bounded_Mailboxes g-boumai ads,GNAT Bubble_Sort g-bubsor ads,GNAT Bounded_Buffers g-boubuf ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-bounded-mailboxes-g-boumai-ads}@anchor{2c8}@anchor{gnat_rm/the_gnat_library id43}@anchor{2c9} +@section @cite{GNAT.Bounded_Mailboxes} (@code{g-boumai.ads}) + + +@geindex GNAT.Bounded_Mailboxes (g-boumai.ads) + +@geindex Parsing + +@geindex Mailboxes -@noindent Provides a thread-safe asynchronous intertask mailbox communication facility. -@node GNAT.Bubble_Sort (g-bubsor.ads) -@section @code{GNAT.Bubble_Sort} (@file{g-bubsor.ads}) -@cindex @code{GNAT.Bubble_Sort} (@file{g-bubsor.ads}) -@cindex Sorting -@cindex Bubble sort +@node GNAT Bubble_Sort g-bubsor ads,GNAT Bubble_Sort_A g-busora ads,GNAT Bounded_Mailboxes g-boumai ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-bubble-sort-g-bubsor-ads}@anchor{2ca}@anchor{gnat_rm/the_gnat_library id44}@anchor{2cb} +@section @cite{GNAT.Bubble_Sort} (@code{g-bubsor.ads}) + + +@geindex GNAT.Bubble_Sort (g-bubsor.ads) + +@geindex Sorting + +@geindex Bubble sort -@noindent Provides a general implementation of bubble sort usable for sorting arbitrary data items. Exchange and comparison procedures are provided by passing access-to-procedure values. -@node GNAT.Bubble_Sort_A (g-busora.ads) -@section @code{GNAT.Bubble_Sort_A} (@file{g-busora.ads}) -@cindex @code{GNAT.Bubble_Sort_A} (@file{g-busora.ads}) -@cindex Sorting -@cindex Bubble sort +@node GNAT Bubble_Sort_A g-busora ads,GNAT Bubble_Sort_G g-busorg ads,GNAT Bubble_Sort g-bubsor ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id45}@anchor{2cc}@anchor{gnat_rm/the_gnat_library gnat-bubble-sort-a-g-busora-ads}@anchor{2cd} +@section @cite{GNAT.Bubble_Sort_A} (@code{g-busora.ads}) + + +@geindex GNAT.Bubble_Sort_A (g-busora.ads) + +@geindex Sorting + +@geindex Bubble sort -@noindent Provides a general implementation of bubble sort usable for sorting arbitrary data items. Move and comparison procedures are provided by passing access-to-procedure values. This is an older version, retained for -compatibility. Usually @code{GNAT.Bubble_Sort} will be preferable. +compatibility. Usually @cite{GNAT.Bubble_Sort} will be preferable. + +@node GNAT Bubble_Sort_G g-busorg ads,GNAT Byte_Order_Mark g-byorma ads,GNAT Bubble_Sort_A g-busora ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id46}@anchor{2ce}@anchor{gnat_rm/the_gnat_library gnat-bubble-sort-g-g-busorg-ads}@anchor{2cf} +@section @cite{GNAT.Bubble_Sort_G} (@code{g-busorg.ads}) + + +@geindex GNAT.Bubble_Sort_G (g-busorg.ads) + +@geindex Sorting -@node GNAT.Bubble_Sort_G (g-busorg.ads) -@section @code{GNAT.Bubble_Sort_G} (@file{g-busorg.ads}) -@cindex @code{GNAT.Bubble_Sort_G} (@file{g-busorg.ads}) -@cindex Sorting -@cindex Bubble sort +@geindex Bubble sort -@noindent -Similar to @code{Bubble_Sort_A} except that the move and sorting procedures +Similar to @cite{Bubble_Sort_A} except that the move and sorting procedures are provided as generic parameters, this improves efficiency, especially if the procedures can be inlined, at the expense of duplicating code for multiple instantiations. -@node GNAT.Byte_Order_Mark (g-byorma.ads) -@section @code{GNAT.Byte_Order_Mark} (@file{g-byorma.ads}) -@cindex @code{GNAT.Byte_Order_Mark} (@file{g-byorma.ads}) -@cindex UTF-8 representation -@cindex Wide characte representations +@node GNAT Byte_Order_Mark g-byorma ads,GNAT Byte_Swapping g-bytswa ads,GNAT Bubble_Sort_G g-busorg ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id47}@anchor{2d0}@anchor{gnat_rm/the_gnat_library gnat-byte-order-mark-g-byorma-ads}@anchor{2d1} +@section @cite{GNAT.Byte_Order_Mark} (@code{g-byorma.ads}) + + +@geindex GNAT.Byte_Order_Mark (g-byorma.ads) + +@geindex UTF-8 representation + +@geindex Wide characte representations -@noindent Provides a routine which given a string, reads the start of the string to see whether it is one of the standard byte order marks (BOM's) which signal the encoding of the string. The routine includes detection of special XML sequences for various UCS input formats. -@node GNAT.Byte_Swapping (g-bytswa.ads) -@section @code{GNAT.Byte_Swapping} (@file{g-bytswa.ads}) -@cindex @code{GNAT.Byte_Swapping} (@file{g-bytswa.ads}) -@cindex Byte swapping -@cindex Endianness +@node GNAT Byte_Swapping g-bytswa ads,GNAT Calendar g-calend ads,GNAT Byte_Order_Mark g-byorma ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-byte-swapping-g-bytswa-ads}@anchor{2d2}@anchor{gnat_rm/the_gnat_library id48}@anchor{2d3} +@section @cite{GNAT.Byte_Swapping} (@code{g-bytswa.ads}) + + +@geindex GNAT.Byte_Swapping (g-bytswa.ads) + +@geindex Byte swapping + +@geindex Endianness -@noindent General routines for swapping the bytes in 2-, 4-, and 8-byte quantities. Machine-specific implementations are available in some cases. -@node GNAT.Calendar (g-calend.ads) -@section @code{GNAT.Calendar} (@file{g-calend.ads}) -@cindex @code{GNAT.Calendar} (@file{g-calend.ads}) -@cindex @code{Calendar} - -@noindent -Extends the facilities provided by @code{Ada.Calendar} to include handling -of days of the week, an extended @code{Split} and @code{Time_Of} capability. -Also provides conversion of @code{Ada.Calendar.Time} values to and from the -C @code{timeval} format. - -@node GNAT.Calendar.Time_IO (g-catiio.ads) -@section @code{GNAT.Calendar.Time_IO} (@file{g-catiio.ads}) -@cindex @code{Calendar} -@cindex Time -@cindex @code{GNAT.Calendar.Time_IO} (@file{g-catiio.ads}) - -@node GNAT.Case_Util (g-casuti.ads) -@section @code{GNAT.Case_Util} (@file{g-casuti.ads}) -@cindex @code{GNAT.Case_Util} (@file{g-casuti.ads}) -@cindex Casing utilities -@cindex Character handling (@code{GNAT.Case_Util}) - -@noindent +@node GNAT Calendar g-calend ads,GNAT Calendar Time_IO g-catiio ads,GNAT Byte_Swapping g-bytswa ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-calendar-g-calend-ads}@anchor{2d4}@anchor{gnat_rm/the_gnat_library id49}@anchor{2d5} +@section @cite{GNAT.Calendar} (@code{g-calend.ads}) + + +@geindex GNAT.Calendar (g-calend.ads) + +@geindex Calendar + +Extends the facilities provided by @cite{Ada.Calendar} to include handling +of days of the week, an extended @cite{Split} and @cite{Time_Of} capability. +Also provides conversion of @cite{Ada.Calendar.Time} values to and from the +C @cite{timeval} format. + +@node GNAT Calendar Time_IO g-catiio ads,GNAT CRC32 g-crc32 ads,GNAT Calendar g-calend ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-calendar-time-io-g-catiio-ads}@anchor{2d6}@anchor{gnat_rm/the_gnat_library id50}@anchor{2d7} +@section @cite{GNAT.Calendar.Time_IO} (@code{g-catiio.ads}) + + +@geindex Calendar + +@geindex Time + +@geindex GNAT.Calendar.Time_IO (g-catiio.ads) + +@node GNAT CRC32 g-crc32 ads,GNAT Case_Util g-casuti ads,GNAT Calendar Time_IO g-catiio ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id51}@anchor{2d8}@anchor{gnat_rm/the_gnat_library gnat-crc32-g-crc32-ads}@anchor{2d9} +@section @cite{GNAT.CRC32} (@code{g-crc32.ads}) + + +@geindex GNAT.CRC32 (g-crc32.ads) + +@geindex CRC32 + +@geindex Cyclic Redundancy Check + +This package implements the CRC-32 algorithm. For a full description +of this algorithm see +@emph{Computation of Cyclic Redundancy Checks via Table Look-Up}, +@cite{Communications of the ACM}, Vol. 31 No. 8, pp. 1008-1013, +Aug. 1988. Sarwate, D.V. + +@node GNAT Case_Util g-casuti ads,GNAT CGI g-cgi ads,GNAT CRC32 g-crc32 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-case-util-g-casuti-ads}@anchor{2da}@anchor{gnat_rm/the_gnat_library id52}@anchor{2db} +@section @cite{GNAT.Case_Util} (@code{g-casuti.ads}) + + +@geindex GNAT.Case_Util (g-casuti.ads) + +@geindex Casing utilities + +@geindex Character handling (`GNAT.Case_Util`) + A set of simple routines for handling upper and lower casing of strings without the overhead of the full casing tables -in @code{Ada.Characters.Handling}. +in @cite{Ada.Characters.Handling}. + +@node GNAT CGI g-cgi ads,GNAT CGI Cookie g-cgicoo ads,GNAT Case_Util g-casuti ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id53}@anchor{2dc}@anchor{gnat_rm/the_gnat_library gnat-cgi-g-cgi-ads}@anchor{2dd} +@section @cite{GNAT.CGI} (@code{g-cgi.ads}) -@node GNAT.CGI (g-cgi.ads) -@section @code{GNAT.CGI} (@file{g-cgi.ads}) -@cindex @code{GNAT.CGI} (@file{g-cgi.ads}) -@cindex CGI (Common Gateway Interface) -@noindent +@geindex GNAT.CGI (g-cgi.ads) + +@geindex CGI (Common Gateway Interface) + This is a package for interfacing a GNAT program with a Web server via the -Common Gateway Interface (CGI)@. Basically this package parses the CGI +Common Gateway Interface (CGI). Basically this package parses the CGI parameters, which are a set of key/value pairs sent by the Web server. It builds a table whose index is the key and provides some services to deal with this table. -@node GNAT.CGI.Cookie (g-cgicoo.ads) -@section @code{GNAT.CGI.Cookie} (@file{g-cgicoo.ads}) -@cindex @code{GNAT.CGI.Cookie} (@file{g-cgicoo.ads}) -@cindex CGI (Common Gateway Interface) cookie support -@cindex Cookie support in CGI +@node GNAT CGI Cookie g-cgicoo ads,GNAT CGI Debug g-cgideb ads,GNAT CGI g-cgi ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id54}@anchor{2de}@anchor{gnat_rm/the_gnat_library gnat-cgi-cookie-g-cgicoo-ads}@anchor{2df} +@section @cite{GNAT.CGI.Cookie} (@code{g-cgicoo.ads}) + + +@geindex GNAT.CGI.Cookie (g-cgicoo.ads) + +@geindex CGI (Common Gateway Interface) cookie support + +@geindex Cookie support in CGI -@noindent This is a package to interface a GNAT program with a Web server via the Common Gateway Interface (CGI). It exports services to deal with Web cookies (piece of information kept in the Web client software). -@node GNAT.CGI.Debug (g-cgideb.ads) -@section @code{GNAT.CGI.Debug} (@file{g-cgideb.ads}) -@cindex @code{GNAT.CGI.Debug} (@file{g-cgideb.ads}) -@cindex CGI (Common Gateway Interface) debugging +@node GNAT CGI Debug g-cgideb ads,GNAT Command_Line g-comlin ads,GNAT CGI Cookie g-cgicoo ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-cgi-debug-g-cgideb-ads}@anchor{2e0}@anchor{gnat_rm/the_gnat_library id55}@anchor{2e1} +@section @cite{GNAT.CGI.Debug} (@code{g-cgideb.ads}) + + +@geindex GNAT.CGI.Debug (g-cgideb.ads) + +@geindex CGI (Common Gateway Interface) debugging -@noindent This is a package to help debugging CGI (Common Gateway Interface) programs written in Ada. -@node GNAT.Command_Line (g-comlin.ads) -@section @code{GNAT.Command_Line} (@file{g-comlin.ads}) -@cindex @code{GNAT.Command_Line} (@file{g-comlin.ads}) -@cindex Command line +@node GNAT Command_Line g-comlin ads,GNAT Compiler_Version g-comver ads,GNAT CGI Debug g-cgideb ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id56}@anchor{2e2}@anchor{gnat_rm/the_gnat_library gnat-command-line-g-comlin-ads}@anchor{2e3} +@section @cite{GNAT.Command_Line} (@code{g-comlin.ads}) -@noindent -Provides a high level interface to @code{Ada.Command_Line} facilities, + +@geindex GNAT.Command_Line (g-comlin.ads) + +@geindex Command line + +Provides a high level interface to @cite{Ada.Command_Line} facilities, including the ability to scan for named switches with optional parameters and expand file names using wild card notations. -@node GNAT.Compiler_Version (g-comver.ads) -@section @code{GNAT.Compiler_Version} (@file{g-comver.ads}) -@cindex @code{GNAT.Compiler_Version} (@file{g-comver.ads}) -@cindex Compiler Version -@cindex Version, of compiler +@node GNAT Compiler_Version g-comver ads,GNAT Ctrl_C g-ctrl_c ads,GNAT Command_Line g-comlin ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-compiler-version-g-comver-ads}@anchor{2e4}@anchor{gnat_rm/the_gnat_library id57}@anchor{2e5} +@section @cite{GNAT.Compiler_Version} (@code{g-comver.ads}) + + +@geindex GNAT.Compiler_Version (g-comver.ads) + +@geindex Compiler Version + +@geindex Version +@geindex of compiler -@noindent Provides a routine for obtaining the version of the compiler used to compile the program. More accurately this is the version of the binder used to bind the program (this will normally be the same as the version of the compiler if a consistent tool set is used to compile all units of a partition). -@node GNAT.Ctrl_C (g-ctrl_c.ads) -@section @code{GNAT.Ctrl_C} (@file{g-ctrl_c.ads}) -@cindex @code{GNAT.Ctrl_C} (@file{g-ctrl_c.ads}) -@cindex Interrupt +@node GNAT Ctrl_C g-ctrl_c ads,GNAT Current_Exception g-curexc ads,GNAT Compiler_Version g-comver ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id58}@anchor{2e6}@anchor{gnat_rm/the_gnat_library gnat-ctrl-c-g-ctrl-c-ads}@anchor{2e7} +@section @cite{GNAT.Ctrl_C} (@code{g-ctrl_c.ads}) + + +@geindex GNAT.Ctrl_C (g-ctrl_c.ads) + +@geindex Interrupt -@noindent Provides a simple interface to handle Ctrl-C keyboard events. -@node GNAT.CRC32 (g-crc32.ads) -@section @code{GNAT.CRC32} (@file{g-crc32.ads}) -@cindex @code{GNAT.CRC32} (@file{g-crc32.ads}) -@cindex CRC32 -@cindex Cyclic Redundancy Check +@node GNAT Current_Exception g-curexc ads,GNAT Debug_Pools g-debpoo ads,GNAT Ctrl_C g-ctrl_c ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id59}@anchor{2e8}@anchor{gnat_rm/the_gnat_library gnat-current-exception-g-curexc-ads}@anchor{2e9} +@section @cite{GNAT.Current_Exception} (@code{g-curexc.ads}) -@noindent -This package implements the CRC-32 algorithm. For a full description -of this algorithm see -``Computation of Cyclic Redundancy Checks via Table Look-Up'', -@cite{Communications of the ACM}, Vol.@: 31 No.@: 8, pp.@: 1008-1013, -Aug.@: 1988. Sarwate, D.V@. -@node GNAT.Current_Exception (g-curexc.ads) -@section @code{GNAT.Current_Exception} (@file{g-curexc.ads}) -@cindex @code{GNAT.Current_Exception} (@file{g-curexc.ads}) -@cindex Current exception -@cindex Exception retrieval +@geindex GNAT.Current_Exception (g-curexc.ads) + +@geindex Current exception + +@geindex Exception retrieval -@noindent Provides access to information on the current exception that has been raised without the need for using the Ada 95 / Ada 2005 exception choice parameter specification syntax. This is particularly useful in simulating typical facilities for obtaining information about exceptions provided by Ada 83 compilers. -@node GNAT.Debug_Pools (g-debpoo.ads) -@section @code{GNAT.Debug_Pools} (@file{g-debpoo.ads}) -@cindex @code{GNAT.Debug_Pools} (@file{g-debpoo.ads}) -@cindex Debugging -@cindex Debug pools -@cindex Memory corruption debugging +@node GNAT Debug_Pools g-debpoo ads,GNAT Debug_Utilities g-debuti ads,GNAT Current_Exception g-curexc ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-debug-pools-g-debpoo-ads}@anchor{2ea}@anchor{gnat_rm/the_gnat_library id60}@anchor{2eb} +@section @cite{GNAT.Debug_Pools} (@code{g-debpoo.ads}) + + +@geindex GNAT.Debug_Pools (g-debpoo.ads) + +@geindex Debugging + +@geindex Debug pools + +@geindex Memory corruption debugging -@noindent Provide a debugging storage pools that helps tracking memory corruption -problems. @xref{The GNAT Debug Pool Facility,,, gnat_ugn, -@value{EDITION} User's Guide}. +problems. +See @cite{The GNAT Debug_Pool Facility} section in the @cite{GNAT User's Guide}. + +@node GNAT Debug_Utilities g-debuti ads,GNAT Decode_String g-decstr ads,GNAT Debug_Pools g-debpoo ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-debug-utilities-g-debuti-ads}@anchor{2ec}@anchor{gnat_rm/the_gnat_library id61}@anchor{2ed} +@section @cite{GNAT.Debug_Utilities} (@code{g-debuti.ads}) -@node GNAT.Debug_Utilities (g-debuti.ads) -@section @code{GNAT.Debug_Utilities} (@file{g-debuti.ads}) -@cindex @code{GNAT.Debug_Utilities} (@file{g-debuti.ads}) -@cindex Debugging -@noindent +@geindex GNAT.Debug_Utilities (g-debuti.ads) + +@geindex Debugging + Provides a few useful utilities for debugging purposes, including conversion to and from string images of address values. Supports both C and Ada formats for hexadecimal literals. -@node GNAT.Decode_String (g-decstr.ads) -@section @code{GNAT.Decode_String} (@file{g-decstr.ads}) -@cindex @code{GNAT.Decode_String} (@file{g-decstr.ads}) -@cindex Decoding strings -@cindex String decoding -@cindex Wide character encoding -@cindex UTF-8 -@cindex Unicode +@node GNAT Decode_String g-decstr ads,GNAT Decode_UTF8_String g-deutst ads,GNAT Debug_Utilities g-debuti ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-decode-string-g-decstr-ads}@anchor{2ee}@anchor{gnat_rm/the_gnat_library id62}@anchor{2ef} +@section @cite{GNAT.Decode_String} (@code{g-decstr.ads}) + + +@geindex GNAT.Decode_String (g-decstr.ads) + +@geindex Decoding strings + +@geindex String decoding + +@geindex Wide character encoding + +@geindex UTF-8 + +@geindex Unicode -@noindent A generic package providing routines for decoding wide character and wide wide character strings encoded as sequences of 8-bit characters using a specified encoding method. Includes validation routines, and also routines for stepping @@ -19896,322 +22844,428 @@ to next or previous encoded character in an encoded string. Useful in conjunction with Unicode character coding. Note there is a preinstantiation for UTF-8. See next entry. -@node GNAT.Decode_UTF8_String (g-deutst.ads) -@section @code{GNAT.Decode_UTF8_String} (@file{g-deutst.ads}) -@cindex @code{GNAT.Decode_UTF8_String} (@file{g-deutst.ads}) -@cindex Decoding strings -@cindex Decoding UTF-8 strings -@cindex UTF-8 string decoding -@cindex Wide character decoding -@cindex UTF-8 -@cindex Unicode - -@noindent +@node GNAT Decode_UTF8_String g-deutst ads,GNAT Directory_Operations g-dirope ads,GNAT Decode_String g-decstr ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-decode-utf8-string-g-deutst-ads}@anchor{2f0}@anchor{gnat_rm/the_gnat_library id63}@anchor{2f1} +@section @cite{GNAT.Decode_UTF8_String} (@code{g-deutst.ads}) + + +@geindex GNAT.Decode_UTF8_String (g-deutst.ads) + +@geindex Decoding strings + +@geindex Decoding UTF-8 strings + +@geindex UTF-8 string decoding + +@geindex Wide character decoding + +@geindex UTF-8 + +@geindex Unicode + A preinstantiation of GNAT.Decode_Strings for UTF-8 encoding. -@node GNAT.Directory_Operations (g-dirope.ads) -@section @code{GNAT.Directory_Operations} (@file{g-dirope.ads}) -@cindex @code{GNAT.Directory_Operations} (@file{g-dirope.ads}) -@cindex Directory operations +@node GNAT Directory_Operations g-dirope ads,GNAT Directory_Operations Iteration g-diopit ads,GNAT Decode_UTF8_String g-deutst ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id64}@anchor{2f2}@anchor{gnat_rm/the_gnat_library gnat-directory-operations-g-dirope-ads}@anchor{2f3} +@section @cite{GNAT.Directory_Operations} (@code{g-dirope.ads}) + + +@geindex GNAT.Directory_Operations (g-dirope.ads) + +@geindex Directory operations -@noindent Provides a set of routines for manipulating directories, including changing the current directory, making new directories, and scanning the files in a directory. -@node GNAT.Directory_Operations.Iteration (g-diopit.ads) -@section @code{GNAT.Directory_Operations.Iteration} (@file{g-diopit.ads}) -@cindex @code{GNAT.Directory_Operations.Iteration} (@file{g-diopit.ads}) -@cindex Directory operations iteration +@node GNAT Directory_Operations Iteration g-diopit ads,GNAT Dynamic_HTables g-dynhta ads,GNAT Directory_Operations g-dirope ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id65}@anchor{2f4}@anchor{gnat_rm/the_gnat_library gnat-directory-operations-iteration-g-diopit-ads}@anchor{2f5} +@section @cite{GNAT.Directory_Operations.Iteration} (@code{g-diopit.ads}) + + +@geindex GNAT.Directory_Operations.Iteration (g-diopit.ads) + +@geindex Directory operations iteration -@noindent A child unit of GNAT.Directory_Operations providing additional operations for iterating through directories. -@node GNAT.Dynamic_HTables (g-dynhta.ads) -@section @code{GNAT.Dynamic_HTables} (@file{g-dynhta.ads}) -@cindex @code{GNAT.Dynamic_HTables} (@file{g-dynhta.ads}) -@cindex Hash tables +@node GNAT Dynamic_HTables g-dynhta ads,GNAT Dynamic_Tables g-dyntab ads,GNAT Directory_Operations Iteration g-diopit ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-dynamic-htables-g-dynhta-ads}@anchor{2f6}@anchor{gnat_rm/the_gnat_library id66}@anchor{2f7} +@section @cite{GNAT.Dynamic_HTables} (@code{g-dynhta.ads}) + + +@geindex GNAT.Dynamic_HTables (g-dynhta.ads) + +@geindex Hash tables -@noindent A generic implementation of hash tables that can be used to hash arbitrary data. Provided in two forms, a simple form with built in hash functions, and a more complex form in which the hash function is supplied. -@noindent -This package provides a facility similar to that of @code{GNAT.HTable}, +This package provides a facility similar to that of @cite{GNAT.HTable}, except that this package declares a type that can be used to define dynamic instances of the hash table, while an instantiation of -@code{GNAT.HTable} creates a single instance of the hash table. +@cite{GNAT.HTable} creates a single instance of the hash table. + +@node GNAT Dynamic_Tables g-dyntab ads,GNAT Encode_String g-encstr ads,GNAT Dynamic_HTables g-dynhta ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-dynamic-tables-g-dyntab-ads}@anchor{2f8}@anchor{gnat_rm/the_gnat_library id67}@anchor{2f9} +@section @cite{GNAT.Dynamic_Tables} (@code{g-dyntab.ads}) + + +@geindex GNAT.Dynamic_Tables (g-dyntab.ads) + +@geindex Table implementation -@node GNAT.Dynamic_Tables (g-dyntab.ads) -@section @code{GNAT.Dynamic_Tables} (@file{g-dyntab.ads}) -@cindex @code{GNAT.Dynamic_Tables} (@file{g-dyntab.ads}) -@cindex Table implementation -@cindex Arrays, extendable +@geindex Arrays +@geindex extendable -@noindent A generic package providing a single dimension array abstraction where the length of the array can be dynamically modified. -@noindent -This package provides a facility similar to that of @code{GNAT.Table}, +This package provides a facility similar to that of @cite{GNAT.Table}, except that this package declares a type that can be used to define dynamic instances of the table, while an instantiation of -@code{GNAT.Table} creates a single instance of the table type. - -@node GNAT.Encode_String (g-encstr.ads) -@section @code{GNAT.Encode_String} (@file{g-encstr.ads}) -@cindex @code{GNAT.Encode_String} (@file{g-encstr.ads}) -@cindex Encoding strings -@cindex String encoding -@cindex Wide character encoding -@cindex UTF-8 -@cindex Unicode - -@noindent +@cite{GNAT.Table} creates a single instance of the table type. + +@node GNAT Encode_String g-encstr ads,GNAT Encode_UTF8_String g-enutst ads,GNAT Dynamic_Tables g-dyntab ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id68}@anchor{2fa}@anchor{gnat_rm/the_gnat_library gnat-encode-string-g-encstr-ads}@anchor{2fb} +@section @cite{GNAT.Encode_String} (@code{g-encstr.ads}) + + +@geindex GNAT.Encode_String (g-encstr.ads) + +@geindex Encoding strings + +@geindex String encoding + +@geindex Wide character encoding + +@geindex UTF-8 + +@geindex Unicode + A generic package providing routines for encoding wide character and wide wide character strings as sequences of 8-bit characters using a specified encoding method. Useful in conjunction with Unicode character coding. Note there is a preinstantiation for UTF-8. See next entry. -@node GNAT.Encode_UTF8_String (g-enutst.ads) -@section @code{GNAT.Encode_UTF8_String} (@file{g-enutst.ads}) -@cindex @code{GNAT.Encode_UTF8_String} (@file{g-enutst.ads}) -@cindex Encoding strings -@cindex Encoding UTF-8 strings -@cindex UTF-8 string encoding -@cindex Wide character encoding -@cindex UTF-8 -@cindex Unicode - -@noindent +@node GNAT Encode_UTF8_String g-enutst ads,GNAT Exception_Actions g-excact ads,GNAT Encode_String g-encstr ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-encode-utf8-string-g-enutst-ads}@anchor{2fc}@anchor{gnat_rm/the_gnat_library id69}@anchor{2fd} +@section @cite{GNAT.Encode_UTF8_String} (@code{g-enutst.ads}) + + +@geindex GNAT.Encode_UTF8_String (g-enutst.ads) + +@geindex Encoding strings + +@geindex Encoding UTF-8 strings + +@geindex UTF-8 string encoding + +@geindex Wide character encoding + +@geindex UTF-8 + +@geindex Unicode + A preinstantiation of GNAT.Encode_Strings for UTF-8 encoding. -@node GNAT.Exception_Actions (g-excact.ads) -@section @code{GNAT.Exception_Actions} (@file{g-excact.ads}) -@cindex @code{GNAT.Exception_Actions} (@file{g-excact.ads}) -@cindex Exception actions +@node GNAT Exception_Actions g-excact ads,GNAT Exception_Traces g-exctra ads,GNAT Encode_UTF8_String g-enutst ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id70}@anchor{2fe}@anchor{gnat_rm/the_gnat_library gnat-exception-actions-g-excact-ads}@anchor{2ff} +@section @cite{GNAT.Exception_Actions} (@code{g-excact.ads}) + + +@geindex GNAT.Exception_Actions (g-excact.ads) + +@geindex Exception actions -@noindent Provides callbacks when an exception is raised. Callbacks can be registered for specific exceptions, or when any exception is raised. This can be used for instance to force a core dump to ease debugging. -@node GNAT.Exception_Traces (g-exctra.ads) -@section @code{GNAT.Exception_Traces} (@file{g-exctra.ads}) -@cindex @code{GNAT.Exception_Traces} (@file{g-exctra.ads}) -@cindex Exception traces -@cindex Debugging +@node GNAT Exception_Traces g-exctra ads,GNAT Exceptions g-expect ads,GNAT Exception_Actions g-excact ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-exception-traces-g-exctra-ads}@anchor{300}@anchor{gnat_rm/the_gnat_library id71}@anchor{301} +@section @cite{GNAT.Exception_Traces} (@code{g-exctra.ads}) + + +@geindex GNAT.Exception_Traces (g-exctra.ads) + +@geindex Exception traces + +@geindex Debugging -@noindent Provides an interface allowing to control automatic output upon exception occurrences. -@node GNAT.Exceptions (g-except.ads) -@section @code{GNAT.Exceptions} (@file{g-expect.ads}) -@cindex @code{GNAT.Exceptions} (@file{g-expect.ads}) -@cindex Exceptions, Pure -@cindex Pure packages, exceptions +@node GNAT Exceptions g-expect ads,GNAT Expect g-expect ads,GNAT Exception_Traces g-exctra ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id72}@anchor{302}@anchor{gnat_rm/the_gnat_library gnat-exceptions-g-expect-ads}@anchor{303} +@section @cite{GNAT.Exceptions} (@code{g-expect.ads}) + + +@geindex GNAT.Exceptions (g-expect.ads) + +@geindex Exceptions +@geindex Pure + +@geindex Pure packages +@geindex exceptions -@noindent Normally it is not possible to raise an exception with a message from a subprogram in a pure package, since the -necessary types and subprograms are in @code{Ada.Exceptions} -which is not a pure unit. @code{GNAT.Exceptions} provides a +necessary types and subprograms are in @cite{Ada.Exceptions} +which is not a pure unit. @cite{GNAT.Exceptions} provides a facility for getting around this limitation for a few predefined exceptions, and for example allow raising -@code{Constraint_Error} with a message from a pure subprogram. +@cite{Constraint_Error} with a message from a pure subprogram. + +@node GNAT Expect g-expect ads,GNAT Expect TTY g-exptty ads,GNAT Exceptions g-expect ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id73}@anchor{304}@anchor{gnat_rm/the_gnat_library gnat-expect-g-expect-ads}@anchor{305} +@section @cite{GNAT.Expect} (@code{g-expect.ads}) + -@node GNAT.Expect (g-expect.ads) -@section @code{GNAT.Expect} (@file{g-expect.ads}) -@cindex @code{GNAT.Expect} (@file{g-expect.ads}) +@geindex GNAT.Expect (g-expect.ads) -@noindent Provides a set of subprograms similar to what is available with the standard Tcl Expect tool. It allows you to easily spawn and communicate with an external process. You can send commands or inputs to the process, and compare the output -with some expected regular expression. Currently @code{GNAT.Expect} -is implemented on all native GNAT ports except for OpenVMS@. +with some expected regular expression. Currently @cite{GNAT.Expect} +is implemented on all native GNAT ports. It is not implemented for cross ports, and in particular is not -implemented for VxWorks or LynxOS@. +implemented for VxWorks or LynxOS. -@node GNAT.Expect.TTY (g-exptty.ads) -@section @code{GNAT.Expect.TTY} (@file{g-exptty.ads}) -@cindex @code{GNAT.Expect.TTY} (@file{g-exptty.ads}) +@node GNAT Expect TTY g-exptty ads,GNAT Float_Control g-flocon ads,GNAT Expect g-expect ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id74}@anchor{306}@anchor{gnat_rm/the_gnat_library gnat-expect-tty-g-exptty-ads}@anchor{307} +@section @cite{GNAT.Expect.TTY} (@code{g-exptty.ads}) + + +@geindex GNAT.Expect.TTY (g-exptty.ads) -@noindent As GNAT.Expect but using pseudo-terminal. -Currently @code{GNAT.Expect.TTY} is implemented on all native GNAT -ports except for OpenVMS@. It is not implemented for cross ports, and -in particular is not implemented for VxWorks or LynxOS@. +Currently @cite{GNAT.Expect.TTY} is implemented on all native GNAT +ports. It is not implemented for cross ports, and +in particular is not implemented for VxWorks or LynxOS. + +@node GNAT Float_Control g-flocon ads,GNAT Formatted_String g-forstr ads,GNAT Expect TTY g-exptty ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id75}@anchor{308}@anchor{gnat_rm/the_gnat_library gnat-float-control-g-flocon-ads}@anchor{309} +@section @cite{GNAT.Float_Control} (@code{g-flocon.ads}) -@node GNAT.Float_Control (g-flocon.ads) -@section @code{GNAT.Float_Control} (@file{g-flocon.ads}) -@cindex @code{GNAT.Float_Control} (@file{g-flocon.ads}) -@cindex Floating-Point Processor -@noindent +@geindex GNAT.Float_Control (g-flocon.ads) + +@geindex Floating-Point Processor + Provides an interface for resetting the floating-point processor into the mode required for correct semantic operation in Ada. Some third party library calls may cause this mode to be modified, and the Reset procedure in this package can be used to reestablish the required mode. -@node GNAT.Formatted_String (g-forstr.ads) -@section @code{GNAT.Formatted_String} (@file{g-forstr.ads}) -@cindex @code{GNAT.Formatted_String} (@file{g-forstr.ads}) -@cindex Formatted String +@node GNAT Formatted_String g-forstr ads,GNAT Heap_Sort g-heasor ads,GNAT Float_Control g-flocon ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id76}@anchor{30a}@anchor{gnat_rm/the_gnat_library gnat-formatted-string-g-forstr-ads}@anchor{30b} +@section @cite{GNAT.Formatted_String} (@code{g-forstr.ads}) + + +@geindex GNAT.Formatted_String (g-forstr.ads) + +@geindex Formatted String -@noindent Provides support for C/C++ printf() formatted strings. The format is copied from the printf() routine and should therefore gives identical output. Some generic routines are provided to be able to use types derived from Integer, Float or enumerations as values for the formatted string. -@node GNAT.Heap_Sort (g-heasor.ads) -@section @code{GNAT.Heap_Sort} (@file{g-heasor.ads}) -@cindex @code{GNAT.Heap_Sort} (@file{g-heasor.ads}) -@cindex Sorting +@node GNAT Heap_Sort g-heasor ads,GNAT Heap_Sort_A g-hesora ads,GNAT Formatted_String g-forstr ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-heap-sort-g-heasor-ads}@anchor{30c}@anchor{gnat_rm/the_gnat_library id77}@anchor{30d} +@section @cite{GNAT.Heap_Sort} (@code{g-heasor.ads}) + + +@geindex GNAT.Heap_Sort (g-heasor.ads) + +@geindex Sorting -@noindent Provides a general implementation of heap sort usable for sorting arbitrary data items. Exchange and comparison procedures are provided by passing access-to-procedure values. The algorithm used is a modified heap sort that performs approximately N*log(N) comparisons in the worst case. -@node GNAT.Heap_Sort_A (g-hesora.ads) -@section @code{GNAT.Heap_Sort_A} (@file{g-hesora.ads}) -@cindex @code{GNAT.Heap_Sort_A} (@file{g-hesora.ads}) -@cindex Sorting +@node GNAT Heap_Sort_A g-hesora ads,GNAT Heap_Sort_G g-hesorg ads,GNAT Heap_Sort g-heasor ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id78}@anchor{30e}@anchor{gnat_rm/the_gnat_library gnat-heap-sort-a-g-hesora-ads}@anchor{30f} +@section @cite{GNAT.Heap_Sort_A} (@code{g-hesora.ads}) + + +@geindex GNAT.Heap_Sort_A (g-hesora.ads) + +@geindex Sorting -@noindent Provides a general implementation of heap sort usable for sorting arbitrary data items. Move and comparison procedures are provided by passing access-to-procedure values. The algorithm used is a modified heap sort that performs approximately N*log(N) comparisons in the worst case. -This differs from @code{GNAT.Heap_Sort} in having a less convenient +This differs from @cite{GNAT.Heap_Sort} in having a less convenient interface, but may be slightly more efficient. -@node GNAT.Heap_Sort_G (g-hesorg.ads) -@section @code{GNAT.Heap_Sort_G} (@file{g-hesorg.ads}) -@cindex @code{GNAT.Heap_Sort_G} (@file{g-hesorg.ads}) -@cindex Sorting +@node GNAT Heap_Sort_G g-hesorg ads,GNAT HTable g-htable ads,GNAT Heap_Sort_A g-hesora ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id79}@anchor{310}@anchor{gnat_rm/the_gnat_library gnat-heap-sort-g-g-hesorg-ads}@anchor{311} +@section @cite{GNAT.Heap_Sort_G} (@code{g-hesorg.ads}) -@noindent -Similar to @code{Heap_Sort_A} except that the move and sorting procedures + +@geindex GNAT.Heap_Sort_G (g-hesorg.ads) + +@geindex Sorting + +Similar to @cite{Heap_Sort_A} except that the move and sorting procedures are provided as generic parameters, this improves efficiency, especially if the procedures can be inlined, at the expense of duplicating code for multiple instantiations. -@node GNAT.HTable (g-htable.ads) -@section @code{GNAT.HTable} (@file{g-htable.ads}) -@cindex @code{GNAT.HTable} (@file{g-htable.ads}) -@cindex Hash tables +@node GNAT HTable g-htable ads,GNAT IO g-io ads,GNAT Heap_Sort_G g-hesorg ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id80}@anchor{312}@anchor{gnat_rm/the_gnat_library gnat-htable-g-htable-ads}@anchor{313} +@section @cite{GNAT.HTable} (@code{g-htable.ads}) + + +@geindex GNAT.HTable (g-htable.ads) + +@geindex Hash tables -@noindent A generic implementation of hash tables that can be used to hash arbitrary data. Provides two approaches, one a simple static approach, and the other allowing arbitrary dynamic hash tables. -@node GNAT.IO (g-io.ads) -@section @code{GNAT.IO} (@file{g-io.ads}) -@cindex @code{GNAT.IO} (@file{g-io.ads}) -@cindex Simple I/O -@cindex Input/Output facilities +@node GNAT IO g-io ads,GNAT IO_Aux g-io_aux ads,GNAT HTable g-htable ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id81}@anchor{314}@anchor{gnat_rm/the_gnat_library gnat-io-g-io-ads}@anchor{315} +@section @cite{GNAT.IO} (@code{g-io.ads}) + + +@geindex GNAT.IO (g-io.ads) + +@geindex Simple I/O + +@geindex Input/Output facilities -@noindent A simple preelaborable input-output package that provides a subset of simple Text_IO functions for reading characters and strings from Standard_Input, and writing characters, strings and integers to either Standard_Output or Standard_Error. -@node GNAT.IO_Aux (g-io_aux.ads) -@section @code{GNAT.IO_Aux} (@file{g-io_aux.ads}) -@cindex @code{GNAT.IO_Aux} (@file{g-io_aux.ads}) -@cindex Text_IO -@cindex Input/Output facilities +@node GNAT IO_Aux g-io_aux ads,GNAT Lock_Files g-locfil ads,GNAT IO g-io ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id82}@anchor{316}@anchor{gnat_rm/the_gnat_library gnat-io-aux-g-io-aux-ads}@anchor{317} +@section @cite{GNAT.IO_Aux} (@code{g-io_aux.ads}) + + +@geindex GNAT.IO_Aux (g-io_aux.ads) + +@geindex Text_IO + +@geindex Input/Output facilities Provides some auxiliary functions for use with Text_IO, including a test for whether a file exists, and functions for reading a line of text. -@node GNAT.Lock_Files (g-locfil.ads) -@section @code{GNAT.Lock_Files} (@file{g-locfil.ads}) -@cindex @code{GNAT.Lock_Files} (@file{g-locfil.ads}) -@cindex File locking -@cindex Locking using files +@node GNAT Lock_Files g-locfil ads,GNAT MBBS_Discrete_Random g-mbdira ads,GNAT IO_Aux g-io_aux ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id83}@anchor{318}@anchor{gnat_rm/the_gnat_library gnat-lock-files-g-locfil-ads}@anchor{319} +@section @cite{GNAT.Lock_Files} (@code{g-locfil.ads}) + + +@geindex GNAT.Lock_Files (g-locfil.ads) + +@geindex File locking + +@geindex Locking using files -@noindent Provides a general interface for using files as locks. Can be used for providing program level synchronization. -@node GNAT.MBBS_Discrete_Random (g-mbdira.ads) -@section @code{GNAT.MBBS_Discrete_Random} (@file{g-mbdira.ads}) -@cindex @code{GNAT.MBBS_Discrete_Random} (@file{g-mbdira.ads}) -@cindex Random number generation +@node GNAT MBBS_Discrete_Random g-mbdira ads,GNAT MBBS_Float_Random g-mbflra ads,GNAT Lock_Files g-locfil ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-mbbs-discrete-random-g-mbdira-ads}@anchor{31a}@anchor{gnat_rm/the_gnat_library id84}@anchor{31b} +@section @cite{GNAT.MBBS_Discrete_Random} (@code{g-mbdira.ads}) -@noindent -The original implementation of @code{Ada.Numerics.Discrete_Random}. Uses + +@geindex GNAT.MBBS_Discrete_Random (g-mbdira.ads) + +@geindex Random number generation + +The original implementation of @cite{Ada.Numerics.Discrete_Random}. Uses a modified version of the Blum-Blum-Shub generator. -@node GNAT.MBBS_Float_Random (g-mbflra.ads) -@section @code{GNAT.MBBS_Float_Random} (@file{g-mbflra.ads}) -@cindex @code{GNAT.MBBS_Float_Random} (@file{g-mbflra.ads}) -@cindex Random number generation +@node GNAT MBBS_Float_Random g-mbflra ads,GNAT MD5 g-md5 ads,GNAT MBBS_Discrete_Random g-mbdira ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id85}@anchor{31c}@anchor{gnat_rm/the_gnat_library gnat-mbbs-float-random-g-mbflra-ads}@anchor{31d} +@section @cite{GNAT.MBBS_Float_Random} (@code{g-mbflra.ads}) + + +@geindex GNAT.MBBS_Float_Random (g-mbflra.ads) -@noindent -The original implementation of @code{Ada.Numerics.Float_Random}. Uses +@geindex Random number generation + +The original implementation of @cite{Ada.Numerics.Float_Random}. Uses a modified version of the Blum-Blum-Shub generator. -@node GNAT.MD5 (g-md5.ads) -@section @code{GNAT.MD5} (@file{g-md5.ads}) -@cindex @code{GNAT.MD5} (@file{g-md5.ads}) -@cindex Message Digest MD5 +@node GNAT MD5 g-md5 ads,GNAT Memory_Dump g-memdum ads,GNAT MBBS_Float_Random g-mbflra ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id86}@anchor{31e}@anchor{gnat_rm/the_gnat_library gnat-md5-g-md5-ads}@anchor{31f} +@section @cite{GNAT.MD5} (@code{g-md5.ads}) + + +@geindex GNAT.MD5 (g-md5.ads) + +@geindex Message Digest MD5 -@noindent Implements the MD5 Message-Digest Algorithm as described in RFC 1321, and the HMAC-MD5 message authentication function as described in RFC 2104 and FIPS PUB 198. -@node GNAT.Memory_Dump (g-memdum.ads) -@section @code{GNAT.Memory_Dump} (@file{g-memdum.ads}) -@cindex @code{GNAT.Memory_Dump} (@file{g-memdum.ads}) -@cindex Dump Memory +@node GNAT Memory_Dump g-memdum ads,GNAT Most_Recent_Exception g-moreex ads,GNAT MD5 g-md5 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id87}@anchor{320}@anchor{gnat_rm/the_gnat_library gnat-memory-dump-g-memdum-ads}@anchor{321} +@section @cite{GNAT.Memory_Dump} (@code{g-memdum.ads}) + + +@geindex GNAT.Memory_Dump (g-memdum.ads) + +@geindex Dump Memory -@noindent Provides a convenient routine for dumping raw memory to either the standard output or standard error files. Uses GNAT.IO for actual output. -@node GNAT.Most_Recent_Exception (g-moreex.ads) -@section @code{GNAT.Most_Recent_Exception} (@file{g-moreex.ads}) -@cindex @code{GNAT.Most_Recent_Exception} (@file{g-moreex.ads}) -@cindex Exception, obtaining most recent +@node GNAT Most_Recent_Exception g-moreex ads,GNAT OS_Lib g-os_lib ads,GNAT Memory_Dump g-memdum ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id88}@anchor{322}@anchor{gnat_rm/the_gnat_library gnat-most-recent-exception-g-moreex-ads}@anchor{323} +@section @cite{GNAT.Most_Recent_Exception} (@code{g-moreex.ads}) + + +@geindex GNAT.Most_Recent_Exception (g-moreex.ads) + +@geindex Exception +@geindex obtaining most recent -@noindent Provides access to the most recently raised exception. Can be used for various logging purposes, including duplicating functionality of some Ada 83 implementation dependent extensions. -@node GNAT.OS_Lib (g-os_lib.ads) -@section @code{GNAT.OS_Lib} (@file{g-os_lib.ads}) -@cindex @code{GNAT.OS_Lib} (@file{g-os_lib.ads}) -@cindex Operating System interface -@cindex Spawn capability +@node GNAT OS_Lib g-os_lib ads,GNAT Perfect_Hash_Generators g-pehage ads,GNAT Most_Recent_Exception g-moreex ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id89}@anchor{324}@anchor{gnat_rm/the_gnat_library gnat-os-lib-g-os-lib-ads}@anchor{325} +@section @cite{GNAT.OS_Lib} (@code{g-os_lib.ads}) + + +@geindex GNAT.OS_Lib (g-os_lib.ads) + +@geindex Operating System interface + +@geindex Spawn capability -@noindent Provides a range of target independent operating system interface functions, including time/date management, file operations, subprocess management, including a portable spawn procedure, and access to environment variables and error return codes. -@node GNAT.Perfect_Hash_Generators (g-pehage.ads) -@section @code{GNAT.Perfect_Hash_Generators} (@file{g-pehage.ads}) -@cindex @code{GNAT.Perfect_Hash_Generators} (@file{g-pehage.ads}) -@cindex Hash functions +@node GNAT Perfect_Hash_Generators g-pehage ads,GNAT Random_Numbers g-rannum ads,GNAT OS_Lib g-os_lib ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id90}@anchor{326}@anchor{gnat_rm/the_gnat_library gnat-perfect-hash-generators-g-pehage-ads}@anchor{327} +@section @cite{GNAT.Perfect_Hash_Generators} (@code{g-pehage.ads}) + + +@geindex GNAT.Perfect_Hash_Generators (g-pehage.ads) + +@geindex Hash functions -@noindent Provides a generator of static minimal perfect hash functions. No collisions occur and each item can be retrieved from the table in one probe (perfect property). The hash table size corresponds to the exact @@ -20221,494 +23275,659 @@ preserving. If w2 is inserted after w1 in the generator, their hashcode are in the same order. These hashing functions are very convenient for use with realtime applications. -@node GNAT.Random_Numbers (g-rannum.ads) -@section @code{GNAT.Random_Numbers} (@file{g-rannum.ads}) -@cindex @code{GNAT.Random_Numbers} (@file{g-rannum.ads}) -@cindex Random number generation +@node GNAT Random_Numbers g-rannum ads,GNAT Regexp g-regexp ads,GNAT Perfect_Hash_Generators g-pehage ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id91}@anchor{328}@anchor{gnat_rm/the_gnat_library gnat-random-numbers-g-rannum-ads}@anchor{329} +@section @cite{GNAT.Random_Numbers} (@code{g-rannum.ads}) + + +@geindex GNAT.Random_Numbers (g-rannum.ads) + +@geindex Random number generation -@noindent Provides random number capabilities which extend those available in the standard Ada library and are more convenient to use. -@node GNAT.Regexp (g-regexp.ads) -@section @code{GNAT.Regexp} (@file{g-regexp.ads}) -@cindex @code{GNAT.Regexp} (@file{g-regexp.ads}) -@cindex Regular expressions -@cindex Pattern matching +@node GNAT Regexp g-regexp ads,GNAT Registry g-regist ads,GNAT Random_Numbers g-rannum ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-regexp-g-regexp-ads}@anchor{1fd}@anchor{gnat_rm/the_gnat_library id92}@anchor{32a} +@section @cite{GNAT.Regexp} (@code{g-regexp.ads}) + + +@geindex GNAT.Regexp (g-regexp.ads) + +@geindex Regular expressions + +@geindex Pattern matching -@noindent A simple implementation of regular expressions, using a subset of regular expression syntax copied from familiar Unix style utilities. This is the simplest of the three pattern matching packages provided, and is particularly -suitable for ``file globbing'' applications. +suitable for 'file globbing' applications. + +@node GNAT Registry g-regist ads,GNAT Regpat g-regpat ads,GNAT Regexp g-regexp ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id93}@anchor{32b}@anchor{gnat_rm/the_gnat_library gnat-registry-g-regist-ads}@anchor{32c} +@section @cite{GNAT.Registry} (@code{g-regist.ads}) + -@node GNAT.Registry (g-regist.ads) -@section @code{GNAT.Registry} (@file{g-regist.ads}) -@cindex @code{GNAT.Registry} (@file{g-regist.ads}) -@cindex Windows Registry +@geindex GNAT.Registry (g-regist.ads) + +@geindex Windows Registry -@noindent This is a high level binding to the Windows registry. It is possible to do simple things like reading a key value, creating a new key. For full registry API, but at a lower level of abstraction, refer to the Win32.Winreg package provided with the Win32Ada binding -@node GNAT.Regpat (g-regpat.ads) -@section @code{GNAT.Regpat} (@file{g-regpat.ads}) -@cindex @code{GNAT.Regpat} (@file{g-regpat.ads}) -@cindex Regular expressions -@cindex Pattern matching +@node GNAT Regpat g-regpat ads,GNAT Rewrite_Data g-rewdat ads,GNAT Registry g-regist ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id94}@anchor{32d}@anchor{gnat_rm/the_gnat_library gnat-regpat-g-regpat-ads}@anchor{32e} +@section @cite{GNAT.Regpat} (@code{g-regpat.ads}) + + +@geindex GNAT.Regpat (g-regpat.ads) + +@geindex Regular expressions + +@geindex Pattern matching -@noindent A complete implementation of Unix-style regular expression matching, copied from the original V7 style regular expression library written in C by Henry Spencer (and binary compatible with this C library). -@node GNAT.Rewrite_Data (g-rewdat.ads) -@section @code{GNAT.Rewrite_Data} (@file{g-rewdat.ads}) -@cindex @code{GNAT.Rewrite_Data} (@file{g-rewdat.ads}) -@cindex Rewrite data +@node GNAT Rewrite_Data g-rewdat ads,GNAT Secondary_Stack_Info g-sestin ads,GNAT Regpat g-regpat ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id95}@anchor{32f}@anchor{gnat_rm/the_gnat_library gnat-rewrite-data-g-rewdat-ads}@anchor{330} +@section @cite{GNAT.Rewrite_Data} (@code{g-rewdat.ads}) + + +@geindex GNAT.Rewrite_Data (g-rewdat.ads) + +@geindex Rewrite data -@noindent A unit to rewrite on-the-fly string occurrences in a stream of data. The implementation has a very minimal memory footprint as the full content to be processed is not loaded into memory all at once. This makes this interface usable for large files or socket streams. -@node GNAT.Secondary_Stack_Info (g-sestin.ads) -@section @code{GNAT.Secondary_Stack_Info} (@file{g-sestin.ads}) -@cindex @code{GNAT.Secondary_Stack_Info} (@file{g-sestin.ads}) -@cindex Secondary Stack Info +@node GNAT Secondary_Stack_Info g-sestin ads,GNAT Semaphores g-semaph ads,GNAT Rewrite_Data g-rewdat ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-secondary-stack-info-g-sestin-ads}@anchor{331}@anchor{gnat_rm/the_gnat_library id96}@anchor{332} +@section @cite{GNAT.Secondary_Stack_Info} (@code{g-sestin.ads}) + + +@geindex GNAT.Secondary_Stack_Info (g-sestin.ads) + +@geindex Secondary Stack Info -@noindent Provide the capability to query the high water mark of the current task's secondary stack. -@node GNAT.Semaphores (g-semaph.ads) -@section @code{GNAT.Semaphores} (@file{g-semaph.ads}) -@cindex @code{GNAT.Semaphores} (@file{g-semaph.ads}) -@cindex Semaphores +@node GNAT Semaphores g-semaph ads,GNAT Serial_Communications g-sercom ads,GNAT Secondary_Stack_Info g-sestin ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-semaphores-g-semaph-ads}@anchor{333}@anchor{gnat_rm/the_gnat_library id97}@anchor{334} +@section @cite{GNAT.Semaphores} (@code{g-semaph.ads}) + + +@geindex GNAT.Semaphores (g-semaph.ads) + +@geindex Semaphores -@noindent Provides classic counting and binary semaphores using protected types. -@node GNAT.Serial_Communications (g-sercom.ads) -@section @code{GNAT.Serial_Communications} (@file{g-sercom.ads}) -@cindex @code{GNAT.Serial_Communications} (@file{g-sercom.ads}) -@cindex Serial_Communications +@node GNAT Serial_Communications g-sercom ads,GNAT SHA1 g-sha1 ads,GNAT Semaphores g-semaph ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id98}@anchor{335}@anchor{gnat_rm/the_gnat_library gnat-serial-communications-g-sercom-ads}@anchor{336} +@section @cite{GNAT.Serial_Communications} (@code{g-sercom.ads}) + + +@geindex GNAT.Serial_Communications (g-sercom.ads) + +@geindex Serial_Communications -@noindent Provides a simple interface to send and receive data over a serial port. This is only supported on GNU/Linux and Windows. -@node GNAT.SHA1 (g-sha1.ads) -@section @code{GNAT.SHA1} (@file{g-sha1.ads}) -@cindex @code{GNAT.SHA1} (@file{g-sha1.ads}) -@cindex Secure Hash Algorithm SHA-1 +@node GNAT SHA1 g-sha1 ads,GNAT SHA224 g-sha224 ads,GNAT Serial_Communications g-sercom ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-sha1-g-sha1-ads}@anchor{337}@anchor{gnat_rm/the_gnat_library id99}@anchor{338} +@section @cite{GNAT.SHA1} (@code{g-sha1.ads}) + + +@geindex GNAT.SHA1 (g-sha1.ads) + +@geindex Secure Hash Algorithm SHA-1 -@noindent Implements the SHA-1 Secure Hash Algorithm as described in FIPS PUB 180-3 and RFC 3174, and the HMAC-SHA1 message authentication function as described in RFC 2104 and FIPS PUB 198. -@node GNAT.SHA224 (g-sha224.ads) -@section @code{GNAT.SHA224} (@file{g-sha224.ads}) -@cindex @code{GNAT.SHA224} (@file{g-sha224.ads}) -@cindex Secure Hash Algorithm SHA-224 +@node GNAT SHA224 g-sha224 ads,GNAT SHA256 g-sha256 ads,GNAT SHA1 g-sha1 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id100}@anchor{339}@anchor{gnat_rm/the_gnat_library gnat-sha224-g-sha224-ads}@anchor{33a} +@section @cite{GNAT.SHA224} (@code{g-sha224.ads}) + + +@geindex GNAT.SHA224 (g-sha224.ads) + +@geindex Secure Hash Algorithm SHA-224 -@noindent Implements the SHA-224 Secure Hash Algorithm as described in FIPS PUB 180-3, and the HMAC-SHA224 message authentication function as described in RFC 2104 and FIPS PUB 198. -@node GNAT.SHA256 (g-sha256.ads) -@section @code{GNAT.SHA256} (@file{g-sha256.ads}) -@cindex @code{GNAT.SHA256} (@file{g-sha256.ads}) -@cindex Secure Hash Algorithm SHA-256 +@node GNAT SHA256 g-sha256 ads,GNAT SHA384 g-sha384 ads,GNAT SHA224 g-sha224 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id101}@anchor{33b}@anchor{gnat_rm/the_gnat_library gnat-sha256-g-sha256-ads}@anchor{33c} +@section @cite{GNAT.SHA256} (@code{g-sha256.ads}) + + +@geindex GNAT.SHA256 (g-sha256.ads) + +@geindex Secure Hash Algorithm SHA-256 -@noindent Implements the SHA-256 Secure Hash Algorithm as described in FIPS PUB 180-3, and the HMAC-SHA256 message authentication function as described in RFC 2104 and FIPS PUB 198. -@node GNAT.SHA384 (g-sha384.ads) -@section @code{GNAT.SHA384} (@file{g-sha384.ads}) -@cindex @code{GNAT.SHA384} (@file{g-sha384.ads}) -@cindex Secure Hash Algorithm SHA-384 +@node GNAT SHA384 g-sha384 ads,GNAT SHA512 g-sha512 ads,GNAT SHA256 g-sha256 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id102}@anchor{33d}@anchor{gnat_rm/the_gnat_library gnat-sha384-g-sha384-ads}@anchor{33e} +@section @cite{GNAT.SHA384} (@code{g-sha384.ads}) + + +@geindex GNAT.SHA384 (g-sha384.ads) + +@geindex Secure Hash Algorithm SHA-384 -@noindent Implements the SHA-384 Secure Hash Algorithm as described in FIPS PUB 180-3, and the HMAC-SHA384 message authentication function as described in RFC 2104 and FIPS PUB 198. -@node GNAT.SHA512 (g-sha512.ads) -@section @code{GNAT.SHA512} (@file{g-sha512.ads}) -@cindex @code{GNAT.SHA512} (@file{g-sha512.ads}) -@cindex Secure Hash Algorithm SHA-512 +@node GNAT SHA512 g-sha512 ads,GNAT Signals g-signal ads,GNAT SHA384 g-sha384 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id103}@anchor{33f}@anchor{gnat_rm/the_gnat_library gnat-sha512-g-sha512-ads}@anchor{340} +@section @cite{GNAT.SHA512} (@code{g-sha512.ads}) + + +@geindex GNAT.SHA512 (g-sha512.ads) + +@geindex Secure Hash Algorithm SHA-512 -@noindent Implements the SHA-512 Secure Hash Algorithm as described in FIPS PUB 180-3, and the HMAC-SHA512 message authentication function as described in RFC 2104 and FIPS PUB 198. -@node GNAT.Signals (g-signal.ads) -@section @code{GNAT.Signals} (@file{g-signal.ads}) -@cindex @code{GNAT.Signals} (@file{g-signal.ads}) -@cindex Signals +@node GNAT Signals g-signal ads,GNAT Sockets g-socket ads,GNAT SHA512 g-sha512 ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-signals-g-signal-ads}@anchor{341}@anchor{gnat_rm/the_gnat_library id104}@anchor{342} +@section @cite{GNAT.Signals} (@code{g-signal.ads}) + + +@geindex GNAT.Signals (g-signal.ads) + +@geindex Signals -@noindent Provides the ability to manipulate the blocked status of signals on supported targets. -@node GNAT.Sockets (g-socket.ads) -@section @code{GNAT.Sockets} (@file{g-socket.ads}) -@cindex @code{GNAT.Sockets} (@file{g-socket.ads}) -@cindex Sockets +@node GNAT Sockets g-socket ads,GNAT Source_Info g-souinf ads,GNAT Signals g-signal ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-sockets-g-socket-ads}@anchor{343}@anchor{gnat_rm/the_gnat_library id105}@anchor{344} +@section @cite{GNAT.Sockets} (@code{g-socket.ads}) + + +@geindex GNAT.Sockets (g-socket.ads) + +@geindex Sockets -@noindent A high level and portable interface to develop sockets based applications. This package is based on the sockets thin binding found in -@code{GNAT.Sockets.Thin}. Currently @code{GNAT.Sockets} is implemented -on all native GNAT ports except for OpenVMS@. It is not implemented -for the LynxOS@ cross port. +@cite{GNAT.Sockets.Thin}. Currently @cite{GNAT.Sockets} is implemented +on all native GNAT ports and on VxWorks cross prots. It is not implemented for +the LynxOS cross port. -@node GNAT.Source_Info (g-souinf.ads) -@section @code{GNAT.Source_Info} (@file{g-souinf.ads}) -@cindex @code{GNAT.Source_Info} (@file{g-souinf.ads}) -@cindex Source Information +@node GNAT Source_Info g-souinf ads,GNAT Spelling_Checker g-speche ads,GNAT Sockets g-socket ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-source-info-g-souinf-ads}@anchor{345}@anchor{gnat_rm/the_gnat_library id106}@anchor{346} +@section @cite{GNAT.Source_Info} (@code{g-souinf.ads}) + + +@geindex GNAT.Source_Info (g-souinf.ads) + +@geindex Source Information -@noindent Provides subprograms that give access to source code information known at compile time, such as the current file name and line number. Also provides subprograms yielding the date and time of the current compilation (like the -C macros @code{__DATE__} and @code{__TIME__}) +C macros @cite{__DATE__} and @cite{__TIME__}) + +@node GNAT Spelling_Checker g-speche ads,GNAT Spelling_Checker_Generic g-spchge ads,GNAT Source_Info g-souinf ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-spelling-checker-g-speche-ads}@anchor{347}@anchor{gnat_rm/the_gnat_library id107}@anchor{348} +@section @cite{GNAT.Spelling_Checker} (@code{g-speche.ads}) + -@node GNAT.Spelling_Checker (g-speche.ads) -@section @code{GNAT.Spelling_Checker} (@file{g-speche.ads}) -@cindex @code{GNAT.Spelling_Checker} (@file{g-speche.ads}) -@cindex Spell checking +@geindex GNAT.Spelling_Checker (g-speche.ads) + +@geindex Spell checking -@noindent Provides a function for determining whether one string is a plausible near misspelling of another string. -@node GNAT.Spelling_Checker_Generic (g-spchge.ads) -@section @code{GNAT.Spelling_Checker_Generic} (@file{g-spchge.ads}) -@cindex @code{GNAT.Spelling_Checker_Generic} (@file{g-spchge.ads}) -@cindex Spell checking +@node GNAT Spelling_Checker_Generic g-spchge ads,GNAT Spitbol Patterns g-spipat ads,GNAT Spelling_Checker g-speche ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-spelling-checker-generic-g-spchge-ads}@anchor{349}@anchor{gnat_rm/the_gnat_library id108}@anchor{34a} +@section @cite{GNAT.Spelling_Checker_Generic} (@code{g-spchge.ads}) + + +@geindex GNAT.Spelling_Checker_Generic (g-spchge.ads) + +@geindex Spell checking -@noindent Provides a generic function that can be instantiated with a string type for determining whether one string is a plausible near misspelling of another string. -@node GNAT.Spitbol.Patterns (g-spipat.ads) -@section @code{GNAT.Spitbol.Patterns} (@file{g-spipat.ads}) -@cindex @code{GNAT.Spitbol.Patterns} (@file{g-spipat.ads}) -@cindex SPITBOL pattern matching -@cindex Pattern matching +@node GNAT Spitbol Patterns g-spipat ads,GNAT Spitbol g-spitbo ads,GNAT Spelling_Checker_Generic g-spchge ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id109}@anchor{34b}@anchor{gnat_rm/the_gnat_library gnat-spitbol-patterns-g-spipat-ads}@anchor{34c} +@section @cite{GNAT.Spitbol.Patterns} (@code{g-spipat.ads}) + + +@geindex GNAT.Spitbol.Patterns (g-spipat.ads) + +@geindex SPITBOL pattern matching + +@geindex Pattern matching -@noindent A complete implementation of SNOBOL4 style pattern matching. This is the most elaborate of the pattern matching packages provided. It fully duplicates the SNOBOL4 dynamic pattern construction and matching capabilities, using the efficient algorithm developed by Robert Dewar for the SPITBOL system. -@node GNAT.Spitbol (g-spitbo.ads) -@section @code{GNAT.Spitbol} (@file{g-spitbo.ads}) -@cindex @code{GNAT.Spitbol} (@file{g-spitbo.ads}) -@cindex SPITBOL interface +@node GNAT Spitbol g-spitbo ads,GNAT Spitbol Table_Boolean g-sptabo ads,GNAT Spitbol Patterns g-spipat ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id110}@anchor{34d}@anchor{gnat_rm/the_gnat_library gnat-spitbol-g-spitbo-ads}@anchor{34e} +@section @cite{GNAT.Spitbol} (@code{g-spitbo.ads}) + + +@geindex GNAT.Spitbol (g-spitbo.ads) + +@geindex SPITBOL interface -@noindent The top level package of the collection of SPITBOL-style functionality, this package provides basic SNOBOL4 string manipulation functions, such as Pad, Reverse, Trim, Substr capability, as well as a generic table function useful for constructing arbitrary mappings from strings in the style of the SNOBOL4 TABLE function. -@node GNAT.Spitbol.Table_Boolean (g-sptabo.ads) -@section @code{GNAT.Spitbol.Table_Boolean} (@file{g-sptabo.ads}) -@cindex @code{GNAT.Spitbol.Table_Boolean} (@file{g-sptabo.ads}) -@cindex Sets of strings -@cindex SPITBOL Tables +@node GNAT Spitbol Table_Boolean g-sptabo ads,GNAT Spitbol Table_Integer g-sptain ads,GNAT Spitbol g-spitbo ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id111}@anchor{34f}@anchor{gnat_rm/the_gnat_library gnat-spitbol-table-boolean-g-sptabo-ads}@anchor{350} +@section @cite{GNAT.Spitbol.Table_Boolean} (@code{g-sptabo.ads}) + -@noindent -A library level of instantiation of @code{GNAT.Spitbol.Patterns.Table} -for type @code{Standard.Boolean}, giving an implementation of sets of +@geindex GNAT.Spitbol.Table_Boolean (g-sptabo.ads) + +@geindex Sets of strings + +@geindex SPITBOL Tables + +A library level of instantiation of @cite{GNAT.Spitbol.Patterns.Table} +for type @cite{Standard.Boolean}, giving an implementation of sets of string values. -@node GNAT.Spitbol.Table_Integer (g-sptain.ads) -@section @code{GNAT.Spitbol.Table_Integer} (@file{g-sptain.ads}) -@cindex @code{GNAT.Spitbol.Table_Integer} (@file{g-sptain.ads}) -@cindex Integer maps -@cindex Maps -@cindex SPITBOL Tables +@node GNAT Spitbol Table_Integer g-sptain ads,GNAT Spitbol Table_VString g-sptavs ads,GNAT Spitbol Table_Boolean g-sptabo ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id112}@anchor{351}@anchor{gnat_rm/the_gnat_library gnat-spitbol-table-integer-g-sptain-ads}@anchor{352} +@section @cite{GNAT.Spitbol.Table_Integer} (@code{g-sptain.ads}) + + +@geindex GNAT.Spitbol.Table_Integer (g-sptain.ads) + +@geindex Integer maps -@noindent -A library level of instantiation of @code{GNAT.Spitbol.Patterns.Table} -for type @code{Standard.Integer}, giving an implementation of maps +@geindex Maps + +@geindex SPITBOL Tables + +A library level of instantiation of @cite{GNAT.Spitbol.Patterns.Table} +for type @cite{Standard.Integer}, giving an implementation of maps from string to integer values. -@node GNAT.Spitbol.Table_VString (g-sptavs.ads) -@section @code{GNAT.Spitbol.Table_VString} (@file{g-sptavs.ads}) -@cindex @code{GNAT.Spitbol.Table_VString} (@file{g-sptavs.ads}) -@cindex String maps -@cindex Maps -@cindex SPITBOL Tables +@node GNAT Spitbol Table_VString g-sptavs ads,GNAT SSE g-sse ads,GNAT Spitbol Table_Integer g-sptain ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id113}@anchor{353}@anchor{gnat_rm/the_gnat_library gnat-spitbol-table-vstring-g-sptavs-ads}@anchor{354} +@section @cite{GNAT.Spitbol.Table_VString} (@code{g-sptavs.ads}) + + +@geindex GNAT.Spitbol.Table_VString (g-sptavs.ads) + +@geindex String maps -@noindent -A library level of instantiation of @code{GNAT.Spitbol.Patterns.Table} for +@geindex Maps + +@geindex SPITBOL Tables + +A library level of instantiation of @cite{GNAT.Spitbol.Patterns.Table} for a variable length string type, giving an implementation of general maps from strings to strings. -@node GNAT.SSE (g-sse.ads) -@section @code{GNAT.SSE} (@file{g-sse.ads}) -@cindex @code{GNAT.SSE} (@file{g-sse.ads}) +@node GNAT SSE g-sse ads,GNAT SSE Vector_Types g-ssvety ads,GNAT Spitbol Table_VString g-sptavs ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id114}@anchor{355}@anchor{gnat_rm/the_gnat_library gnat-sse-g-sse-ads}@anchor{356} +@section @cite{GNAT.SSE} (@code{g-sse.ads}) + + +@geindex GNAT.SSE (g-sse.ads) -@noindent Root of a set of units aimed at offering Ada bindings to a subset of the Intel(r) Streaming SIMD Extensions with GNAT on the x86 family of targets. It exposes vector component types together with a general introduction to the binding contents and use. -@node GNAT.SSE.Vector_Types (g-ssvety.ads) -@section @code{GNAT.SSE.Vector_Types} (@file{g-ssvety.ads}) -@cindex @code{GNAT.SSE.Vector_Types} (@file{g-ssvety.ads}) +@node GNAT SSE Vector_Types g-ssvety ads,GNAT Strings g-string ads,GNAT SSE g-sse ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-sse-vector-types-g-ssvety-ads}@anchor{357}@anchor{gnat_rm/the_gnat_library id115}@anchor{358} +@section @cite{GNAT.SSE.Vector_Types} (@code{g-ssvety.ads}) + + +@geindex GNAT.SSE.Vector_Types (g-ssvety.ads) -@noindent SSE vector types for use with SSE related intrinsics. -@node GNAT.Strings (g-string.ads) -@section @code{GNAT.Strings} (@file{g-string.ads}) -@cindex @code{GNAT.Strings} (@file{g-string.ads}) +@node GNAT Strings g-string ads,GNAT String_Split g-strspl ads,GNAT SSE Vector_Types g-ssvety ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id116}@anchor{359}@anchor{gnat_rm/the_gnat_library gnat-strings-g-string-ads}@anchor{35a} +@section @cite{GNAT.Strings} (@code{g-string.ads}) + + +@geindex GNAT.Strings (g-string.ads) -@noindent Common String access types and related subprograms. Basically it defines a string access and an array of string access types. -@node GNAT.String_Split (g-strspl.ads) -@section @code{GNAT.String_Split} (@file{g-strspl.ads}) -@cindex @code{GNAT.String_Split} (@file{g-strspl.ads}) -@cindex String splitter +@node GNAT String_Split g-strspl ads,GNAT Table g-table ads,GNAT Strings g-string ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-string-split-g-strspl-ads}@anchor{35b}@anchor{gnat_rm/the_gnat_library id117}@anchor{35c} +@section @cite{GNAT.String_Split} (@code{g-strspl.ads}) + + +@geindex GNAT.String_Split (g-strspl.ads) + +@geindex String splitter -@noindent Useful string manipulation routines: given a set of separators, split a string wherever the separators appear, and provide direct access to the resulting slices. This package is instantiated from -@code{GNAT.Array_Split}. +@cite{GNAT.Array_Split}. + +@node GNAT Table g-table ads,GNAT Task_Lock g-tasloc ads,GNAT String_Split g-strspl ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id118}@anchor{35d}@anchor{gnat_rm/the_gnat_library gnat-table-g-table-ads}@anchor{35e} +@section @cite{GNAT.Table} (@code{g-table.ads}) -@node GNAT.Table (g-table.ads) -@section @code{GNAT.Table} (@file{g-table.ads}) -@cindex @code{GNAT.Table} (@file{g-table.ads}) -@cindex Table implementation -@cindex Arrays, extendable -@noindent +@geindex GNAT.Table (g-table.ads) + +@geindex Table implementation + +@geindex Arrays +@geindex extendable + A generic package providing a single dimension array abstraction where the length of the array can be dynamically modified. -@noindent -This package provides a facility similar to that of @code{GNAT.Dynamic_Tables}, +This package provides a facility similar to that of @cite{GNAT.Dynamic_Tables}, except that this package declares a single instance of the table type, -while an instantiation of @code{GNAT.Dynamic_Tables} creates a type that can be +while an instantiation of @cite{GNAT.Dynamic_Tables} creates a type that can be used to define dynamic instances of the table. -@node GNAT.Task_Lock (g-tasloc.ads) -@section @code{GNAT.Task_Lock} (@file{g-tasloc.ads}) -@cindex @code{GNAT.Task_Lock} (@file{g-tasloc.ads}) -@cindex Task synchronization -@cindex Task locking -@cindex Locking +@node GNAT Task_Lock g-tasloc ads,GNAT Time_Stamp g-timsta ads,GNAT Table g-table ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-task-lock-g-tasloc-ads}@anchor{35f}@anchor{gnat_rm/the_gnat_library id119}@anchor{360} +@section @cite{GNAT.Task_Lock} (@code{g-tasloc.ads}) + + +@geindex GNAT.Task_Lock (g-tasloc.ads) + +@geindex Task synchronization + +@geindex Task locking + +@geindex Locking -@noindent A very simple facility for locking and unlocking sections of code using a single global task lock. Appropriate for use in situations where contention between tasks is very rarely expected. -@node GNAT.Threads (g-thread.ads) -@section @code{GNAT.Threads} (@file{g-thread.ads}) -@cindex @code{GNAT.Threads} (@file{g-thread.ads}) -@cindex Foreign threads -@cindex Threads, foreign +@node GNAT Time_Stamp g-timsta ads,GNAT Threads g-thread ads,GNAT Task_Lock g-tasloc ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-time-stamp-g-timsta-ads}@anchor{361}@anchor{gnat_rm/the_gnat_library id120}@anchor{362} +@section @cite{GNAT.Time_Stamp} (@code{g-timsta.ads}) + + +@geindex GNAT.Time_Stamp (g-timsta.ads) + +@geindex Time stamp + +@geindex Current time + +Provides a simple function that returns a string YYYY-MM-DD HH:MM:SS.SS that +represents the current date and time in ISO 8601 format. This is a very simple +routine with minimal code and there are no dependencies on any other unit. + +@node GNAT Threads g-thread ads,GNAT Traceback g-traceb ads,GNAT Time_Stamp g-timsta ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-threads-g-thread-ads}@anchor{363}@anchor{gnat_rm/the_gnat_library id121}@anchor{364} +@section @cite{GNAT.Threads} (@code{g-thread.ads}) + + +@geindex GNAT.Threads (g-thread.ads) + +@geindex Foreign threads + +@geindex Threads +@geindex foreign -@noindent Provides facilities for dealing with foreign threads which need to be known by the GNAT run-time system. Consult the documentation of this package for further details if your program has threads that are created by a non-Ada environment which then accesses Ada code. -@node GNAT.Time_Stamp (g-timsta.ads) -@section @code{GNAT.Time_Stamp} (@file{g-timsta.ads}) -@cindex @code{GNAT.Time_Stamp} (@file{g-timsta.ads}) -@cindex Time stamp -@cindex Current time +@node GNAT Traceback g-traceb ads,GNAT Traceback Symbolic g-trasym ads,GNAT Threads g-thread ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id122}@anchor{365}@anchor{gnat_rm/the_gnat_library gnat-traceback-g-traceb-ads}@anchor{366} +@section @cite{GNAT.Traceback} (@code{g-traceb.ads}) -@noindent -Provides a simple function that returns a string YYYY-MM-DD HH:MM:SS.SS that -represents the current date and time in ISO 8601 format. This is a very simple -routine with minimal code and there are no dependencies on any other unit. -@node GNAT.Traceback (g-traceb.ads) -@section @code{GNAT.Traceback} (@file{g-traceb.ads}) -@cindex @code{GNAT.Traceback} (@file{g-traceb.ads}) -@cindex Trace back facilities +@geindex GNAT.Traceback (g-traceb.ads) + +@geindex Trace back facilities -@noindent Provides a facility for obtaining non-symbolic traceback information, useful in various debugging situations. -@node GNAT.Traceback.Symbolic (g-trasym.ads) -@section @code{GNAT.Traceback.Symbolic} (@file{g-trasym.ads}) -@cindex @code{GNAT.Traceback.Symbolic} (@file{g-trasym.ads}) -@cindex Trace back facilities +@node GNAT Traceback Symbolic g-trasym ads,GNAT UTF_32 g-table ads,GNAT Traceback g-traceb ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-traceback-symbolic-g-trasym-ads}@anchor{367}@anchor{gnat_rm/the_gnat_library id123}@anchor{368} +@section @cite{GNAT.Traceback.Symbolic} (@code{g-trasym.ads}) + + +@geindex GNAT.Traceback.Symbolic (g-trasym.ads) + +@geindex Trace back facilities -@node GNAT.UTF_32 (g-utf_32.ads) -@section @code{GNAT.UTF_32} (@file{g-table.ads}) -@cindex @code{GNAT.UTF_32} (@file{g-table.ads}) -@cindex Wide character codes +@node GNAT UTF_32 g-table ads,GNAT Wide_Spelling_Checker g-u3spch ads,GNAT Traceback Symbolic g-trasym ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id124}@anchor{369}@anchor{gnat_rm/the_gnat_library gnat-utf-32-g-table-ads}@anchor{36a} +@section @cite{GNAT.UTF_32} (@code{g-table.ads}) + + +@geindex GNAT.UTF_32 (g-table.ads) + +@geindex Wide character codes -@noindent This is a package intended to be used in conjunction with the -@code{Wide_Character} type in Ada 95 and the -@code{Wide_Wide_Character} type in Ada 2005 (available -in @code{GNAT} in Ada 2005 mode). This package contains +@cite{Wide_Character} type in Ada 95 and the +@cite{Wide_Wide_Character} type in Ada 2005 (available +in @cite{GNAT} in Ada 2005 mode). This package contains Unicode categorization routines, as well as lexical categorization routines corresponding to the Ada 2005 lexical rules for identifiers and strings, and also a lower case to upper case fold routine corresponding to the Ada 2005 rules for identifier equivalence. -@node GNAT.UTF_32_Spelling_Checker (g-u3spch.ads) -@section @code{GNAT.Wide_Spelling_Checker} (@file{g-u3spch.ads}) -@cindex @code{GNAT.Wide_Spelling_Checker} (@file{g-u3spch.ads}) -@cindex Spell checking +@node GNAT Wide_Spelling_Checker g-u3spch ads,GNAT Wide_Spelling_Checker g-wispch ads,GNAT UTF_32 g-table ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-wide-spelling-checker-g-u3spch-ads}@anchor{36b}@anchor{gnat_rm/the_gnat_library id125}@anchor{36c} +@section @cite{GNAT.Wide_Spelling_Checker} (@code{g-u3spch.ads}) + + +@geindex GNAT.Wide_Spelling_Checker (g-u3spch.ads) + +@geindex Spell checking -@noindent Provides a function for determining whether one wide wide string is a plausible near misspelling of another wide wide string, where the strings are represented using the UTF_32_String type defined in System.Wch_Cnv. -@node GNAT.Wide_Spelling_Checker (g-wispch.ads) -@section @code{GNAT.Wide_Spelling_Checker} (@file{g-wispch.ads}) -@cindex @code{GNAT.Wide_Spelling_Checker} (@file{g-wispch.ads}) -@cindex Spell checking +@node GNAT Wide_Spelling_Checker g-wispch ads,GNAT Wide_String_Split g-wistsp ads,GNAT Wide_Spelling_Checker g-u3spch ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-wide-spelling-checker-g-wispch-ads}@anchor{36d}@anchor{gnat_rm/the_gnat_library id126}@anchor{36e} +@section @cite{GNAT.Wide_Spelling_Checker} (@code{g-wispch.ads}) + + +@geindex GNAT.Wide_Spelling_Checker (g-wispch.ads) + +@geindex Spell checking -@noindent Provides a function for determining whether one wide string is a plausible near misspelling of another wide string. -@node GNAT.Wide_String_Split (g-wistsp.ads) -@section @code{GNAT.Wide_String_Split} (@file{g-wistsp.ads}) -@cindex @code{GNAT.Wide_String_Split} (@file{g-wistsp.ads}) -@cindex Wide_String splitter +@node GNAT Wide_String_Split g-wistsp ads,GNAT Wide_Wide_Spelling_Checker g-zspche ads,GNAT Wide_Spelling_Checker g-wispch ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id127}@anchor{36f}@anchor{gnat_rm/the_gnat_library gnat-wide-string-split-g-wistsp-ads}@anchor{370} +@section @cite{GNAT.Wide_String_Split} (@code{g-wistsp.ads}) + + +@geindex GNAT.Wide_String_Split (g-wistsp.ads) + +@geindex Wide_String splitter -@noindent Useful wide string manipulation routines: given a set of separators, split a wide string wherever the separators appear, and provide direct access to the resulting slices. This package is instantiated from -@code{GNAT.Array_Split}. +@cite{GNAT.Array_Split}. + +@node GNAT Wide_Wide_Spelling_Checker g-zspche ads,GNAT Wide_Wide_String_Split g-zistsp ads,GNAT Wide_String_Split g-wistsp ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-wide-wide-spelling-checker-g-zspche-ads}@anchor{371}@anchor{gnat_rm/the_gnat_library id128}@anchor{372} +@section @cite{GNAT.Wide_Wide_Spelling_Checker} (@code{g-zspche.ads}) + -@node GNAT.Wide_Wide_Spelling_Checker (g-zspche.ads) -@section @code{GNAT.Wide_Wide_Spelling_Checker} (@file{g-zspche.ads}) -@cindex @code{GNAT.Wide_Wide_Spelling_Checker} (@file{g-zspche.ads}) -@cindex Spell checking +@geindex GNAT.Wide_Wide_Spelling_Checker (g-zspche.ads) + +@geindex Spell checking -@noindent Provides a function for determining whether one wide wide string is a plausible near misspelling of another wide wide string. -@node GNAT.Wide_Wide_String_Split (g-zistsp.ads) -@section @code{GNAT.Wide_Wide_String_Split} (@file{g-zistsp.ads}) -@cindex @code{GNAT.Wide_Wide_String_Split} (@file{g-zistsp.ads}) -@cindex Wide_Wide_String splitter +@node GNAT Wide_Wide_String_Split g-zistsp ads,Interfaces C Extensions i-cexten ads,GNAT Wide_Wide_Spelling_Checker g-zspche ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library gnat-wide-wide-string-split-g-zistsp-ads}@anchor{373}@anchor{gnat_rm/the_gnat_library id129}@anchor{374} +@section @cite{GNAT.Wide_Wide_String_Split} (@code{g-zistsp.ads}) + + +@geindex GNAT.Wide_Wide_String_Split (g-zistsp.ads) + +@geindex Wide_Wide_String splitter -@noindent Useful wide wide string manipulation routines: given a set of separators, split a wide wide string wherever the separators appear, and provide direct access to the resulting slices. This package is instantiated from -@code{GNAT.Array_Split}. +@cite{GNAT.Array_Split}. + +@node Interfaces C Extensions i-cexten ads,Interfaces C Streams i-cstrea ads,GNAT Wide_Wide_String_Split g-zistsp ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id130}@anchor{375}@anchor{gnat_rm/the_gnat_library interfaces-c-extensions-i-cexten-ads}@anchor{376} +@section @cite{Interfaces.C.Extensions} (@code{i-cexten.ads}) + -@node Interfaces.C.Extensions (i-cexten.ads) -@section @code{Interfaces.C.Extensions} (@file{i-cexten.ads}) -@cindex @code{Interfaces.C.Extensions} (@file{i-cexten.ads}) +@geindex Interfaces.C.Extensions (i-cexten.ads) -@noindent This package contains additional C-related definitions, intended for use with either manually or automatically generated bindings to C libraries. -@node Interfaces.C.Streams (i-cstrea.ads) -@section @code{Interfaces.C.Streams} (@file{i-cstrea.ads}) -@cindex @code{Interfaces.C.Streams} (@file{i-cstrea.ads}) -@cindex C streams, interfacing +@node Interfaces C Streams i-cstrea ads,Interfaces Packed_Decimal i-pacdec ads,Interfaces C Extensions i-cexten ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id131}@anchor{377}@anchor{gnat_rm/the_gnat_library interfaces-c-streams-i-cstrea-ads}@anchor{378} +@section @cite{Interfaces.C.Streams} (@code{i-cstrea.ads}) + + +@geindex Interfaces.C.Streams (i-cstrea.ads) + +@geindex C streams +@geindex interfacing -@noindent This package is a binding for the most commonly used operations on C streams. -@node Interfaces.Packed_Decimal (i-pacdec.ads) -@section @code{Interfaces.Packed_Decimal} (@file{i-pacdec.ads}) -@cindex @code{Interfaces.Packed_Decimal} (@file{i-pacdec.ads}) -@cindex IBM Packed Format -@cindex Packed Decimal +@node Interfaces Packed_Decimal i-pacdec ads,Interfaces VxWorks i-vxwork ads,Interfaces C Streams i-cstrea ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library interfaces-packed-decimal-i-pacdec-ads}@anchor{379}@anchor{gnat_rm/the_gnat_library id132}@anchor{37a} +@section @cite{Interfaces.Packed_Decimal} (@code{i-pacdec.ads}) + + +@geindex Interfaces.Packed_Decimal (i-pacdec.ads) + +@geindex IBM Packed Format + +@geindex Packed Decimal -@noindent This package provides a set of routines for conversions to and from a packed decimal format compatible with that used on IBM mainframes. -@node Interfaces.VxWorks (i-vxwork.ads) -@section @code{Interfaces.VxWorks} (@file{i-vxwork.ads}) -@cindex @code{Interfaces.VxWorks} (@file{i-vxwork.ads}) -@cindex Interfacing to VxWorks -@cindex VxWorks, interfacing +@node Interfaces VxWorks i-vxwork ads,Interfaces VxWorks IO i-vxwoio ads,Interfaces Packed_Decimal i-pacdec ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id133}@anchor{37b}@anchor{gnat_rm/the_gnat_library interfaces-vxworks-i-vxwork-ads}@anchor{37c} +@section @cite{Interfaces.VxWorks} (@code{i-vxwork.ads}) + + +@geindex Interfaces.VxWorks (i-vxwork.ads) + +@geindex Interfacing to VxWorks + +@geindex VxWorks +@geindex interfacing -@noindent This package provides a limited binding to the VxWorks API. In particular, it interfaces with the VxWorks hardware interrupt facilities. -@node Interfaces.VxWorks.IO (i-vxwoio.ads) -@section @code{Interfaces.VxWorks.IO} (@file{i-vxwoio.ads}) -@cindex @code{Interfaces.VxWorks.IO} (@file{i-vxwoio.ads}) -@cindex Interfacing to VxWorks' I/O -@cindex VxWorks, I/O interfacing -@cindex VxWorks, Get_Immediate -@cindex Get_Immediate, VxWorks +@node Interfaces VxWorks IO i-vxwoio ads,System Address_Image s-addima ads,Interfaces VxWorks i-vxwork ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library interfaces-vxworks-io-i-vxwoio-ads}@anchor{37d}@anchor{gnat_rm/the_gnat_library id134}@anchor{37e} +@section @cite{Interfaces.VxWorks.IO} (@code{i-vxwoio.ads}) + + +@geindex Interfaces.VxWorks.IO (i-vxwoio.ads) + +@geindex Interfacing to VxWorks' I/O + +@geindex VxWorks +@geindex I/O interfacing + +@geindex VxWorks +@geindex Get_Immediate + +@geindex Get_Immediate +@geindex VxWorks -@noindent This package provides a binding to the ioctl (IO/Control) function of VxWorks, defining a set of option values and function codes. A particular use of this package is to enable the use of Get_Immediate under VxWorks. -@node System.Address_Image (s-addima.ads) -@section @code{System.Address_Image} (@file{s-addima.ads}) -@cindex @code{System.Address_Image} (@file{s-addima.ads}) -@cindex Address image -@cindex Image, of an address +@node System Address_Image s-addima ads,System Assertions s-assert ads,Interfaces VxWorks IO i-vxwoio ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library system-address-image-s-addima-ads}@anchor{37f}@anchor{gnat_rm/the_gnat_library id135}@anchor{380} +@section @cite{System.Address_Image} (@code{s-addima.ads}) + + +@geindex System.Address_Image (s-addima.ads) + +@geindex Address image + +@geindex Image +@geindex of an address -@noindent This function provides a useful debugging function that gives an (implementation dependent) string which identifies an address. -@node System.Assertions (s-assert.ads) -@section @code{System.Assertions} (@file{s-assert.ads}) -@cindex @code{System.Assertions} (@file{s-assert.ads}) -@cindex Assertions -@cindex Assert_Failure, exception +@node System Assertions s-assert ads,System Atomic_Counters s-atocou ads,System Address_Image s-addima ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library system-assertions-s-assert-ads}@anchor{381}@anchor{gnat_rm/the_gnat_library id136}@anchor{382} +@section @cite{System.Assertions} (@code{s-assert.ads}) + + +@geindex System.Assertions (s-assert.ads) + +@geindex Assertions + +@geindex Assert_Failure +@geindex exception -@noindent This package provides the declaration of the exception raised by an run-time assertion failure, as well as the routine that is used internally to raise this assertion. -@node System.Atomic_Counters (s-atocou.ads) -@section @code{System.Atomic_Counters} (@file{s-atocou.ads}) -@cindex @code{System.Atomic_Counters} (@file{s-atocou.ads}) +@node System Atomic_Counters s-atocou ads,System Memory s-memory ads,System Assertions s-assert ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id137}@anchor{383}@anchor{gnat_rm/the_gnat_library system-atomic-counters-s-atocou-ads}@anchor{384} +@section @cite{System.Atomic_Counters} (@code{s-atocou.ads}) + + +@geindex System.Atomic_Counters (s-atocou.ads) -@noindent This package provides the declaration of an atomic counter type, together with efficient routines (using hardware synchronization primitives) for incrementing, decrementing, @@ -20716,12 +23935,15 @@ and testing of these counters. This package is implemented on most targets, including all Alpha, ia64, PowerPC, SPARC V9, x86, and x86_64 platforms. -@node System.Memory (s-memory.ads) -@section @code{System.Memory} (@file{s-memory.ads}) -@cindex @code{System.Memory} (@file{s-memory.ads}) -@cindex Memory allocation +@node System Memory s-memory ads,System Multiprocessors s-multip ads,System Atomic_Counters s-atocou ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library system-memory-s-memory-ads}@anchor{385}@anchor{gnat_rm/the_gnat_library id138}@anchor{386} +@section @cite{System.Memory} (@code{s-memory.ads}) + + +@geindex System.Memory (s-memory.ads) + +@geindex Memory allocation -@noindent This package provides the interface to the low level routines used by the generated code for allocation and freeing storage for the default storage pool (analogous to the C routines malloc and free. @@ -20729,64 +23951,90 @@ It also provides a reallocation interface analogous to the C routine realloc. The body of this unit may be modified to provide alternative allocation mechanisms for the default pool, and in addition, direct calls to this unit may be made for low level allocation uses (for -example see the body of @code{GNAT.Tables}). +example see the body of @cite{GNAT.Tables}). + +@node System Multiprocessors s-multip ads,System Multiprocessors Dispatching_Domains s-mudido ads,System Memory s-memory ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id139}@anchor{387}@anchor{gnat_rm/the_gnat_library system-multiprocessors-s-multip-ads}@anchor{388} +@section @cite{System.Multiprocessors} (@code{s-multip.ads}) + + +@geindex System.Multiprocessors (s-multip.ads) + +@geindex Multiprocessor interface -@node System.Multiprocessors (s-multip.ads) -@section @code{System.Multiprocessors} (@file{s-multip.ads}) -@cindex @code{System.Multiprocessors} (@file{s-multip.ads}) -@cindex Multiprocessor interface This is an Ada 2012 unit defined in the Ada 2012 Reference Manual, but in GNAT we also make it available in Ada 95 and Ada 2005 (where it is technically an implementation-defined addition). -@node System.Multiprocessors.Dispatching_Domains (s-mudido.ads) -@section @code{System.Multiprocessors.Dispatching_Domains} (@file{s-mudido.ads}) -@cindex @code{System.Multiprocessors.Dispatching_Domains} (@file{s-mudido.ads}) -@cindex Multiprocessor interface +@node System Multiprocessors Dispatching_Domains s-mudido ads,System Partition_Interface s-parint ads,System Multiprocessors s-multip ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library system-multiprocessors-dispatching-domains-s-mudido-ads}@anchor{389}@anchor{gnat_rm/the_gnat_library id140}@anchor{38a} +@section @cite{System.Multiprocessors.Dispatching_Domains} (@code{s-mudido.ads}) + + +@geindex System.Multiprocessors.Dispatching_Domains (s-mudido.ads) + +@geindex Multiprocessor interface + This is an Ada 2012 unit defined in the Ada 2012 Reference Manual, but in GNAT we also make it available in Ada 95 and Ada 2005 (where it is technically an implementation-defined addition). -@node System.Partition_Interface (s-parint.ads) -@section @code{System.Partition_Interface} (@file{s-parint.ads}) -@cindex @code{System.Partition_Interface} (@file{s-parint.ads}) -@cindex Partition interfacing functions +@node System Partition_Interface s-parint ads,System Pool_Global s-pooglo ads,System Multiprocessors Dispatching_Domains s-mudido ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id141}@anchor{38b}@anchor{gnat_rm/the_gnat_library system-partition-interface-s-parint-ads}@anchor{38c} +@section @cite{System.Partition_Interface} (@code{s-parint.ads}) + + +@geindex System.Partition_Interface (s-parint.ads) + +@geindex Partition interfacing functions -@noindent This package provides facilities for partition interfacing. It is used primarily in a distribution context when using Annex E -with @code{GLADE}. +with @cite{GLADE}. + +@node System Pool_Global s-pooglo ads,System Pool_Local s-pooloc ads,System Partition_Interface s-parint ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id142}@anchor{38d}@anchor{gnat_rm/the_gnat_library system-pool-global-s-pooglo-ads}@anchor{38e} +@section @cite{System.Pool_Global} (@code{s-pooglo.ads}) + -@node System.Pool_Global (s-pooglo.ads) -@section @code{System.Pool_Global} (@file{s-pooglo.ads}) -@cindex @code{System.Pool_Global} (@file{s-pooglo.ads}) -@cindex Storage pool, global -@cindex Global storage pool +@geindex System.Pool_Global (s-pooglo.ads) + +@geindex Storage pool +@geindex global + +@geindex Global storage pool -@noindent This package provides a storage pool that is equivalent to the default storage pool used for access types for which no pool is specifically declared. It uses malloc/free to allocate/free and does not attempt to do any automatic reclamation. -@node System.Pool_Local (s-pooloc.ads) -@section @code{System.Pool_Local} (@file{s-pooloc.ads}) -@cindex @code{System.Pool_Local} (@file{s-pooloc.ads}) -@cindex Storage pool, local -@cindex Local storage pool +@node System Pool_Local s-pooloc ads,System Restrictions s-restri ads,System Pool_Global s-pooglo ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library system-pool-local-s-pooloc-ads}@anchor{38f}@anchor{gnat_rm/the_gnat_library id143}@anchor{390} +@section @cite{System.Pool_Local} (@code{s-pooloc.ads}) + + +@geindex System.Pool_Local (s-pooloc.ads) + +@geindex Storage pool +@geindex local + +@geindex Local storage pool -@noindent This package provides a storage pool that is intended for use with locally defined access types. It uses malloc/free for allocate/free, and maintains a list of allocated blocks, so that all storage allocated for the pool can be freed automatically when the pool is finalized. -@node System.Restrictions (s-restri.ads) -@section @code{System.Restrictions} (@file{s-restri.ads}) -@cindex @code{System.Restrictions} (@file{s-restri.ads}) -@cindex Run-time restrictions access +@node System Restrictions s-restri ads,System Rident s-rident ads,System Pool_Local s-pooloc ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id144}@anchor{391}@anchor{gnat_rm/the_gnat_library system-restrictions-s-restri-ads}@anchor{392} +@section @cite{System.Restrictions} (@code{s-restri.ads}) + + +@geindex System.Restrictions (s-restri.ads) + +@geindex Run-time restrictions access -@noindent This package provides facilities for accessing at run time the status of restrictions specified at compile time for the partition. Information is available both with regard @@ -20794,224 +24042,322 @@ to actual restrictions specified, and with regard to compiler determined information on which restrictions are violated by one or more packages in the partition. -@node System.Rident (s-rident.ads) -@section @code{System.Rident} (@file{s-rident.ads}) -@cindex @code{System.Rident} (@file{s-rident.ads}) -@cindex Restrictions definitions +@node System Rident s-rident ads,System Strings Stream_Ops s-ststop ads,System Restrictions s-restri ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id145}@anchor{393}@anchor{gnat_rm/the_gnat_library system-rident-s-rident-ads}@anchor{394} +@section @cite{System.Rident} (@code{s-rident.ads}) + + +@geindex System.Rident (s-rident.ads) + +@geindex Restrictions definitions -@noindent This package provides definitions of the restrictions identifiers supported by GNAT, and also the format of the restrictions provided in package System.Restrictions. -It is not normally necessary to @code{with} this generic package +It is not normally necessary to @cite{with} this generic package since the necessary instantiation is included in package System.Restrictions. -@node System.Strings.Stream_Ops (s-ststop.ads) -@section @code{System.Strings.Stream_Ops} (@file{s-ststop.ads}) -@cindex @code{System.Strings.Stream_Ops} (@file{s-ststop.ads}) -@cindex Stream operations -@cindex String stream operations +@node System Strings Stream_Ops s-ststop ads,System Unsigned_Types s-unstyp ads,System Rident s-rident ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library id146}@anchor{395}@anchor{gnat_rm/the_gnat_library system-strings-stream-ops-s-ststop-ads}@anchor{396} +@section @cite{System.Strings.Stream_Ops} (@code{s-ststop.ads}) + + +@geindex System.Strings.Stream_Ops (s-ststop.ads) + +@geindex Stream operations + +@geindex String stream operations -@noindent This package provides a set of stream subprograms for standard string types. It is intended primarily to support implicit use of such subprograms when stream attributes are applied to string types, but the subprograms in this package can be used directly by application programs. -@node System.Unsigned_Types (s-unstyp.ads) -@section @code{System.Unsigned_Types} (@file{s-unstyp.ads}) -@cindex @code{System.Unsigned_Types} (@file{s-unstyp.ads}) +@node System Unsigned_Types s-unstyp ads,System Wch_Cnv s-wchcnv ads,System Strings Stream_Ops s-ststop ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library system-unsigned-types-s-unstyp-ads}@anchor{397}@anchor{gnat_rm/the_gnat_library id147}@anchor{398} +@section @cite{System.Unsigned_Types} (@code{s-unstyp.ads}) + + +@geindex System.Unsigned_Types (s-unstyp.ads) -@noindent This package contains definitions of standard unsigned types that correspond in size to the standard signed types declared in Standard, and (unlike the types in Interfaces) have corresponding names. It also contains some related definitions for other specialized types used by the compiler in connection with packed array types. -@node System.Wch_Cnv (s-wchcnv.ads) -@section @code{System.Wch_Cnv} (@file{s-wchcnv.ads}) -@cindex @code{System.Wch_Cnv} (@file{s-wchcnv.ads}) -@cindex Wide Character, Representation -@cindex Wide String, Conversion -@cindex Representation of wide characters +@node System Wch_Cnv s-wchcnv ads,System Wch_Con s-wchcon ads,System Unsigned_Types s-unstyp ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library system-wch-cnv-s-wchcnv-ads}@anchor{399}@anchor{gnat_rm/the_gnat_library id148}@anchor{39a} +@section @cite{System.Wch_Cnv} (@code{s-wchcnv.ads}) + + +@geindex System.Wch_Cnv (s-wchcnv.ads) + +@geindex Wide Character +@geindex Representation + +@geindex Wide String +@geindex Conversion + +@geindex Representation of wide characters -@noindent This package provides routines for converting between wide and wide wide characters and a representation as a value of type -@code{Standard.String}, using a specified wide character +@cite{Standard.String}, using a specified wide character encoding method. It uses definitions in -package @code{System.Wch_Con}. +package @cite{System.Wch_Con}. -@node System.Wch_Con (s-wchcon.ads) -@section @code{System.Wch_Con} (@file{s-wchcon.ads}) -@cindex @code{System.Wch_Con} (@file{s-wchcon.ads}) +@node System Wch_Con s-wchcon ads,,System Wch_Cnv s-wchcnv ads,The GNAT Library +@anchor{gnat_rm/the_gnat_library system-wch-con-s-wchcon-ads}@anchor{39b}@anchor{gnat_rm/the_gnat_library id149}@anchor{39c} +@section @cite{System.Wch_Con} (@code{s-wchcon.ads}) + + +@geindex System.Wch_Con (s-wchcon.ads) -@noindent This package provides definitions and descriptions of the various methods used for encoding wide characters in ordinary strings. These definitions are used by -the package @code{System.Wch_Cnv}. +the package @cite{System.Wch_Cnv}. -@node Interfacing to Other Languages +@node Interfacing to Other Languages,Specialized Needs Annexes,The GNAT Library,Top +@anchor{gnat_rm/interfacing_to_other_languages interfacing-to-other-languages}@anchor{11}@anchor{gnat_rm/interfacing_to_other_languages doc}@anchor{39d}@anchor{gnat_rm/interfacing_to_other_languages id1}@anchor{39e} @chapter Interfacing to Other Languages -@noindent -The facilities in annex B of the Ada Reference Manual are fully + + +The facilities in Annex B of the Ada Reference Manual are fully implemented in GNAT, and in addition, a full interface to C++ is provided. @menu -* Interfacing to C:: -* Interfacing to C++:: -* Interfacing to COBOL:: -* Interfacing to Fortran:: -* Interfacing to non-GNAT Ada code:: +* Interfacing to C:: +* Interfacing to C++:: +* Interfacing to COBOL:: +* Interfacing to Fortran:: +* Interfacing to non-GNAT Ada code:: + @end menu -@node Interfacing to C +@node Interfacing to C,Interfacing to C++,,Interfacing to Other Languages +@anchor{gnat_rm/interfacing_to_other_languages interfacing-to-c}@anchor{39f}@anchor{gnat_rm/interfacing_to_other_languages id2}@anchor{3a0} @section Interfacing to C -@noindent + Interfacing to C with GNAT can use one of two approaches: -@itemize @bullet -@item -The types in the package @code{Interfaces.C} may be used. -@item + +@itemize * + +@item +The types in the package @cite{Interfaces.C} may be used. + +@item Standard Ada types may be used directly. This may be less portable to other compilers, but will work on all GNAT compilers, which guarantee correspondence between the C and Ada types. @end itemize -@noindent -Pragma @code{Convention C} may be applied to Ada types, but mostly has no +Pragma @cite{Convention C} may be applied to Ada types, but mostly has no effect, since this is the default. The following table shows the correspondence between Ada scalar types and the corresponding C types. -@table @code -@item Integer + +@multitable {xxxxxxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} +@headitem + +Ada Type + +@tab + +C Type + +@item + +@code{Integer} + +@tab + @code{int} -@item Short_Integer + +@item + +@code{Short_Integer} + +@tab + @code{short} -@item Short_Short_Integer + +@item + +@code{Short_Short_Integer} + +@tab + @code{signed char} -@item Long_Integer + +@item + +@code{Long_Integer} + +@tab + @code{long} -@item Long_Long_Integer + +@item + +@code{Long_Long_Integer} + +@tab + @code{long long} -@item Short_Float + +@item + +@code{Short_Float} + +@tab + @code{float} -@item Float + +@item + +@code{Float} + +@tab + @code{float} -@item Long_Float + +@item + +@code{Long_Float} + +@tab + @code{double} -@item Long_Long_Float + +@item + +@code{Long_Long_Float} + +@tab + This is the longest floating-point type supported by the hardware. -@end table -@noindent +@end multitable + + Additionally, there are the following general correspondences between Ada and C types: -@itemize @bullet -@item + + +@itemize * + +@item Ada enumeration types map to C enumeration types directly if pragma -@code{Convention C} is specified, which causes them to have int -length. Without pragma @code{Convention C}, Ada enumeration types map to -8, 16, or 32 bits (i.e.@: C types @code{signed char}, @code{short}, -@code{int}, respectively) depending on the number of values passed. -This is the only case in which pragma @code{Convention C} affects the +@cite{Convention C} is specified, which causes them to have int +length. Without pragma @cite{Convention C}, Ada enumeration types map to +8, 16, or 32 bits (i.e., C types @cite{signed char}, @cite{short}, +@cite{int}, respectively) depending on the number of values passed. +This is the only case in which pragma @cite{Convention C} affects the representation of an Ada type. -@item +@item Ada access types map to C pointers, except for the case of pointers to unconstrained types in Ada, which have no direct C equivalent. -@item +@item Ada arrays map directly to C arrays. -@item +@item Ada records map directly to C structures. -@item +@item Packed Ada records map to C structures where all members are bit fields -of the length corresponding to the @code{@var{type}'Size} value in Ada. +of the length corresponding to the @code{type'Size} value in Ada. @end itemize -@node Interfacing to C++ +@node Interfacing to C++,Interfacing to COBOL,Interfacing to C,Interfacing to Other Languages +@anchor{gnat_rm/interfacing_to_other_languages id4}@anchor{3a1}@anchor{gnat_rm/interfacing_to_other_languages id3}@anchor{3f} @section Interfacing to C++ -@noindent + The interface to C++ makes use of the following pragmas, which are primarily intended to be constructed automatically using a binding generator tool, although it is possible to construct them by hand. Using these pragmas it is possible to achieve complete inter-operability between Ada tagged types and C++ class definitions. -See @ref{Implementation Defined Pragmas}, for more details. +See @ref{7,,Implementation Defined Pragmas}, for more details. + + +@table @asis + +@item @emph{pragma CPP_Class ([Entity =>] `LOCAL_NAME`)} -@table @code -@item pragma CPP_Class ([Entity =>] @var{LOCAL_NAME}) The argument denotes an entity in the current declarative region that is declared as a tagged or untagged record type. It indicates that the type corresponds to an externally declared C++ class type, and is to be laid out the same way that C++ would lay out the type. -Note: Pragma @code{CPP_Class} is currently obsolete. It is supported +Note: Pragma @cite{CPP_Class} is currently obsolete. It is supported for backward compatibility but its functionality is available -using pragma @code{Import} with @code{Convention} = @code{CPP}. +using pragma @cite{Import} with @cite{Convention} = @cite{CPP}. + +@item @emph{pragma CPP_Constructor ([Entity =>] `LOCAL_NAME`)} -@item pragma CPP_Constructor ([Entity =>] @var{LOCAL_NAME}) This pragma identifies an imported function (imported in the usual way -with pragma @code{Import}) as corresponding to a C++ constructor. +with pragma @cite{Import}) as corresponding to a C++ constructor. @end table -A few restrictions are placed on the use of the @code{Access} attribute -in conjunction with subprograms subject to convention @code{CPP}: the +A few restrictions are placed on the use of the @cite{Access} attribute +in conjunction with subprograms subject to convention @cite{CPP}: the attribute may be used neither on primitive operations of a tagged -record type with convention @code{CPP}, imported or not, nor on -subprograms imported with pragma @code{CPP_Constructor}. +record type with convention @cite{CPP}, imported or not, nor on +subprograms imported with pragma @cite{CPP_Constructor}. In addition, C++ exceptions are propagated and can be handled in an -@code{others} choice of an exception handler. The corresponding Ada +@cite{others} choice of an exception handler. The corresponding Ada occurrence has no message, and the simple name of the exception identity -contains @samp{Foreign_Exception}. Finalization and awaiting dependent +contains @code{Foreign_Exception}. Finalization and awaiting dependent tasks works properly when such foreign exceptions are propagated. It is also possible to import a C++ exception using the following syntax: -@smallexample @c ada +@example LOCAL_NAME : exception; pragma Import (Cpp, [Entity =>] LOCAL_NAME, [External_Name =>] static_string_EXPRESSION); -@end smallexample +@end example -@noindent -The @code{External_Name} is the name of the C++ RTTI symbol. You can then +The @cite{External_Name} is the name of the C++ RTTI symbol. You can then cover a specific C++ exception in an exception handler. -@node Interfacing to COBOL +@node Interfacing to COBOL,Interfacing to Fortran,Interfacing to C++,Interfacing to Other Languages +@anchor{gnat_rm/interfacing_to_other_languages id5}@anchor{3a2}@anchor{gnat_rm/interfacing_to_other_languages interfacing-to-cobol}@anchor{3a3} @section Interfacing to COBOL -@noindent + Interfacing to COBOL is achieved as described in section B.4 of the Ada Reference Manual. -@node Interfacing to Fortran +@node Interfacing to Fortran,Interfacing to non-GNAT Ada code,Interfacing to COBOL,Interfacing to Other Languages +@anchor{gnat_rm/interfacing_to_other_languages id6}@anchor{3a4}@anchor{gnat_rm/interfacing_to_other_languages interfacing-to-fortran}@anchor{3a5} @section Interfacing to Fortran -@noindent + Interfacing to Fortran is achieved as described in section B.5 of the -Ada Reference Manual. The pragma @code{Convention Fortran}, applied to a +Ada Reference Manual. The pragma @cite{Convention Fortran}, applied to a multi-dimensional array causes the array to be stored in column-major order as required for convenient interface to Fortran. -@node Interfacing to non-GNAT Ada code +@node Interfacing to non-GNAT Ada code,,Interfacing to Fortran,Interfacing to Other Languages +@anchor{gnat_rm/interfacing_to_other_languages interfacing-to-non-gnat-ada-code}@anchor{3a6}@anchor{gnat_rm/interfacing_to_other_languages id7}@anchor{3a7} @section Interfacing to non-GNAT Ada code -It is possible to specify the convention @code{Ada} in a pragma -@code{Import} or pragma @code{Export}. However this refers to + +It is possible to specify the convention @cite{Ada} in a pragma +@cite{Import} or pragma @cite{Export}. However this refers to the calling conventions used by GNAT, which may or may not be similar enough to those used by some other Ada 83 / Ada 95 / Ada 2005 compiler to allow interoperation. @@ -21029,177 +24375,191 @@ provided that the data items passed are restricted to simple scalar values or simple record types without variants, or simple array types with fixed bounds. -@node Specialized Needs Annexes +@node Specialized Needs Annexes,Implementation of Specific Ada Features,Interfacing to Other Languages,Top +@anchor{gnat_rm/specialized_needs_annexes specialized-needs-annexes}@anchor{12}@anchor{gnat_rm/specialized_needs_annexes doc}@anchor{3a8}@anchor{gnat_rm/specialized_needs_annexes id1}@anchor{3a9} @chapter Specialized Needs Annexes -@noindent -Ada 95 and Ada 2005 define a number of Specialized Needs Annexes, which are not + +Ada 95, Ada 2005, and Ada 2012 define a number of Specialized Needs Annexes, which are not required in all implementations. However, as described in this chapter, GNAT implements all of these annexes: + @table @asis -@item Systems Programming (Annex C) + +@item @emph{Systems Programming (Annex C)} + The Systems Programming Annex is fully implemented. -@item Real-Time Systems (Annex D) +@item @emph{Real-Time Systems (Annex D)} + The Real-Time Systems Annex is fully implemented. -@item Distributed Systems (Annex E) +@item @emph{Distributed Systems (Annex E)} + Stub generation is fully implemented in the GNAT compiler. In addition, a complete compatible PCS is available as part of the GLADE system, a separate product. When the two products are used in conjunction, this annex is fully implemented. -@item Information Systems (Annex F) +@item @emph{Information Systems (Annex F)} + The Information Systems annex is fully implemented. -@item Numerics (Annex G) +@item @emph{Numerics (Annex G)} + The Numerics Annex is fully implemented. -@item Safety and Security / High-Integrity Systems (Annex H) +@item @emph{Safety and Security / High-Integrity Systems (Annex H)} + The Safety and Security Annex (termed the High-Integrity Systems Annex in Ada 2005) is fully implemented. @end table -@node Implementation of Specific Ada Features +@node Implementation of Specific Ada Features,Implementation of Ada 2012 Features,Specialized Needs Annexes,Top +@anchor{gnat_rm/implementation_of_specific_ada_features implementation-of-specific-ada-features}@anchor{13}@anchor{gnat_rm/implementation_of_specific_ada_features doc}@anchor{3aa}@anchor{gnat_rm/implementation_of_specific_ada_features id1}@anchor{3ab} @chapter Implementation of Specific Ada Features -@noindent + This chapter describes the GNAT implementation of several Ada language facilities. @menu -* Machine Code Insertions:: -* GNAT Implementation of Tasking:: -* GNAT Implementation of Shared Passive Packages:: -* Code Generation for Array Aggregates:: -* The Size of Discriminated Records with Default Discriminants:: -* Strict Conformance to the Ada Reference Manual:: +* Machine Code Insertions:: +* GNAT Implementation of Tasking:: +* GNAT Implementation of Shared Passive Packages:: +* Code Generation for Array Aggregates:: +* The Size of Discriminated Records with Default Discriminants:: +* Strict Conformance to the Ada Reference Manual:: + @end menu -@node Machine Code Insertions +@node Machine Code Insertions,GNAT Implementation of Tasking,,Implementation of Specific Ada Features +@anchor{gnat_rm/implementation_of_specific_ada_features machine-code-insertions}@anchor{119}@anchor{gnat_rm/implementation_of_specific_ada_features id2}@anchor{3ac} @section Machine Code Insertions -@cindex Machine Code insertions -@noindent -Package @code{Machine_Code} provides machine code support as described + +@geindex Machine Code insertions + +Package @cite{Machine_Code} provides machine code support as described in the Ada Reference Manual in two separate forms: -@itemize @bullet -@item + + +@itemize * + +@item Machine code statements, consisting of qualified expressions that fit the requirements of RM section 13.8. -@item + +@item An intrinsic callable procedure, providing an alternative mechanism of including machine instructions in a subprogram. @end itemize -@noindent The two features are similar, and both are closely related to the mechanism provided by the asm instruction in the GNU C compiler. Full understanding and use of the facilities in this package requires understanding the asm -instruction, see @ref{Extended Asm,,, gcc, Using the GNU Compiler -Collection (GCC)}. +instruction, see the section on Extended Asm in +@cite{Using_the_GNU_Compiler_Collection_(GCC)}. -Calls to the function @code{Asm} and the procedure @code{Asm} have identical +Calls to the function @cite{Asm} and the procedure @cite{Asm} have identical semantic restrictions and effects as described below. Both are provided so that the procedure call can be used as a statement, and the function call can be used to form a code_statement. -Consider this C @code{asm} instruction: -@smallexample - asm ("fsinx %1 %0" : "=f" (result) : "f" (angle)); -@end smallexample +Consider this C @cite{asm} instruction: + +@example +asm ("fsinx %1 %0" : "=f" (result) : "f" (angle)); +@end example -@noindent The equivalent can be written for GNAT as: -@smallexample @c ada +@example Asm ("fsinx %1 %0", My_Float'Asm_Output ("=f", result), My_Float'Asm_Input ("f", angle)); -@end smallexample +@end example -@noindent -The first argument to @code{Asm} is the assembler template, and is -identical to what is used in GNU C@. This string must be a static +The first argument to @cite{Asm} is the assembler template, and is +identical to what is used in GNU C. This string must be a static expression. The second argument is the output operand list. It is -either a single @code{Asm_Output} attribute reference, or a list of such +either a single @cite{Asm_Output} attribute reference, or a list of such references enclosed in parentheses (technically an array aggregate of such references). -The @code{Asm_Output} attribute denotes a function that takes two +The @cite{Asm_Output} attribute denotes a function that takes two parameters. The first is a string, the second is the name of a variable of the type designated by the attribute prefix. The first (string) argument is required to be a static expression and designates the -constraint (@pxref{Constraints,,, gcc, Using the GNU Compiler -Collection (GCC)}) -for the parameter (e.g.@: what kind of register is required). The second +constraint (see the section on Constraints in +@cite{Using_the_GNU_Compiler_Collection_(GCC)}) +for the parameter; e.g., what kind of register is required. The second argument is the variable to be written or updated with the result. The possible values for constraint are the same as those used in the RTL, and are dependent on the configuration file used to build the GCC back end. If there are no output operands, then this argument may -either be omitted, or explicitly given as @code{No_Output_Operands}. +either be omitted, or explicitly given as @cite{No_Output_Operands}. No support is provided for GNU C's symbolic names for output parameters. -The second argument of @code{@var{my_float}'Asm_Output} functions as -though it were an @code{out} parameter, which is a little curious, but +The second argument of @code{my_float'Asm_Output} functions as +though it were an @cite{out} parameter, which is a little curious, but all names have the form of expressions, so there is no syntactic irregularity, even though normally functions would not be permitted -@code{out} parameters. The third argument is the list of input -operands. It is either a single @code{Asm_Input} attribute reference, or +@cite{out} parameters. The third argument is the list of input +operands. It is either a single @cite{Asm_Input} attribute reference, or a list of such references enclosed in parentheses (technically an array aggregate of such references). -The @code{Asm_Input} attribute denotes a function that takes two +The @cite{Asm_Input} attribute denotes a function that takes two parameters. The first is a string, the second is an expression of the type designated by the prefix. The first (string) argument is required to be a static expression, and is the constraint for the parameter, -(e.g.@: what kind of register is required). The second argument is the +(e.g., what kind of register is required). The second argument is the value to be used as the input argument. The possible values for the constraint are the same as those used in the RTL, and are dependent on the configuration file used to built the GCC back end. No support is provided for GNU C's symbolic names for input parameters. If there are no input operands, this argument may either be omitted, or -explicitly given as @code{No_Input_Operands}. The fourth argument, not +explicitly given as @cite{No_Input_Operands}. The fourth argument, not present in the above example, is a list of register names, called the -@dfn{clobber} argument. This argument, if given, must be a static string +@emph{clobber} argument. This argument, if given, must be a static string expression, and is a space or comma separated list of names of registers -that must be considered destroyed as a result of the @code{Asm} call. If +that must be considered destroyed as a result of the @cite{Asm} call. If this argument is the null string (the default value), then the code generator assumes that no additional registers are destroyed. -In addition to registers, the special clobbers @code{memory} and -@code{cc} as described in the GNU C docs are both supported. +In addition to registers, the special clobbers @cite{memory} and +@cite{cc} as described in the GNU C docs are both supported. The fifth argument, not present in the above example, called the -@dfn{volatile} argument, is by default @code{False}. It can be set to -the literal value @code{True} to indicate to the code generator that all +@emph{volatile} argument, is by default @cite{False}. It can be set to +the literal value @cite{True} to indicate to the code generator that all optimizations with respect to the instruction specified should be suppressed, and in particular an instruction that has outputs will still be generated, even if none of the outputs are -used. @xref{Volatile,,, -gcc, Using the GNU Compiler Collection (GCC)}, for the full description. +used. See @cite{Using_the_GNU_Compiler_Collection_(GCC)} +for the full description. Generally it is strongly advisable to use Volatile for any ASM statement that is missing either input or output operands or to avoid unwanted optimizations. A warning is generated if this advice is not followed. -No support is provided for GNU C's @code{asm goto} feature. +No support is provided for GNU C's @cite{asm goto} feature. -The @code{Asm} subprograms may be used in two ways. First the procedure +The @cite{Asm} subprograms may be used in two ways. First the procedure forms can be used anywhere a procedure call would be valid, and -correspond to what the RM calls ``intrinsic'' routines. Such calls can +correspond to what the RM calls 'intrinsic' routines. Such calls can be used to intersperse machine instructions with other Ada statements. Second, the function forms, which return a dummy value of the limited -private type @code{Asm_Insn}, can be used in code statements, and indeed +private type @cite{Asm_Insn}, can be used in code statements, and indeed this is the only context where such calls are allowed. Code statements appear as aggregates of the form: -@smallexample @c ada -Asm_Insn'(Asm (@dots{})); -Asm_Insn'(Asm_Volatile (@dots{})); -@end smallexample +@example +Asm_Insn'(Asm (...)); +Asm_Insn'(Asm_Volatile (...)); +@end example -@noindent In accordance with RM rules, such code statements are allowed only within subprograms whose entire body consists of such statements. It is not permissible to intermix such statements with other Ada statements. @@ -21207,11 +24567,11 @@ not permissible to intermix such statements with other Ada statements. Typically the form using intrinsic procedure calls is more convenient and more flexible. The code statement form is provided to meet the RM suggestion that such a facility should be made available. The following -is the exact syntax of the call to @code{Asm}. As usual, if named notation +is the exact syntax of the call to @cite{Asm}. As usual, if named notation is used, the arguments may be given in arbitrary order, following the normal rules for use of positional and named arguments: -@smallexample +@example ASM_CALL ::= Asm ( [Template =>] static_string_EXPRESSION [,[Outputs =>] OUTPUT_OPERAND_LIST ] @@ -21234,42 +24594,48 @@ INPUT_OPERAND_LIST ::= INPUT_OPERAND_ATTRIBUTE ::= SUBTYPE_MARK'Asm_Input (static_string_EXPRESSION, EXPRESSION) -@end smallexample +@end example -@noindent -The identifiers @code{No_Input_Operands} and @code{No_Output_Operands} -are declared in the package @code{Machine_Code} and must be referenced +The identifiers @cite{No_Input_Operands} and @cite{No_Output_Operands} +are declared in the package @cite{Machine_Code} and must be referenced according to normal visibility rules. In particular if there is no -@code{use} clause for this package, then appropriate package name +@cite{use} clause for this package, then appropriate package name qualification is required. -@node GNAT Implementation of Tasking +@node GNAT Implementation of Tasking,GNAT Implementation of Shared Passive Packages,Machine Code Insertions,Implementation of Specific Ada Features +@anchor{gnat_rm/implementation_of_specific_ada_features id3}@anchor{3ad}@anchor{gnat_rm/implementation_of_specific_ada_features gnat-implementation-of-tasking}@anchor{3ae} @section GNAT Implementation of Tasking -@noindent + This chapter outlines the basic GNAT approach to tasking (in particular, a multi-layered library for portability) and discusses issues related to compliance with the Real-Time Systems Annex. @menu -* Mapping Ada Tasks onto the Underlying Kernel Threads:: -* Ensuring Compliance with the Real-Time Annex:: +* Mapping Ada Tasks onto the Underlying Kernel Threads:: +* Ensuring Compliance with the Real-Time Annex:: + @end menu -@node Mapping Ada Tasks onto the Underlying Kernel Threads +@node Mapping Ada Tasks onto the Underlying Kernel Threads,Ensuring Compliance with the Real-Time Annex,,GNAT Implementation of Tasking +@anchor{gnat_rm/implementation_of_specific_ada_features mapping-ada-tasks-onto-the-underlying-kernel-threads}@anchor{3af}@anchor{gnat_rm/implementation_of_specific_ada_features id4}@anchor{3b0} @subsection Mapping Ada Tasks onto the Underlying Kernel Threads -@noindent + GNAT's run-time support comprises two layers: -@itemize @bullet -@item GNARL (GNAT Run-time Layer) -@item GNULL (GNAT Low-level Library) + +@itemize * + +@item +GNARL (GNAT Run-time Layer) + +@item +GNULL (GNAT Low-level Library) @end itemize -@noindent In GNAT, Ada's tasking services rely on a platform and OS independent -layer known as GNARL@. This code is responsible for implementing the +layer known as GNARL. This code is responsible for implementing the correct semantics of Ada's task creation, rendezvous, protected operations etc. @@ -21277,13 +24643,13 @@ GNARL decomposes Ada's tasking semantics into simpler lower level operations such as create a thread, set the priority of a thread, yield, create a lock, lock/unlock, etc. The spec for these low-level operations constitutes GNULLI, the GNULL Interface. This interface is -directly inspired from the POSIX real-time API@. +directly inspired from the POSIX real-time API. If the underlying executive or OS implements the POSIX standard faithfully, the GNULL Interface maps as is to the services offered by the underlying kernel. Otherwise, some target dependent glue code maps the services offered by the underlying kernel to the semantics expected -by GNARL@. +by GNARL. Whatever the underlying OS (VxWorks, UNIX, Windows, etc.) the key point is that each Ada task is mapped on a thread in the underlying @@ -21292,46 +24658,50 @@ kernel. For example, in the case of VxWorks, one Ada task = one VxWorks task. In addition Ada task priorities map onto the underlying thread priorities. Mapping Ada tasks onto the underlying kernel threads has several advantages: -@itemize @bullet -@item + +@itemize * + +@item The underlying scheduler is used to schedule the Ada tasks. This makes Ada tasks as efficient as kernel threads from a scheduling standpoint. -@item +@item Interaction with code written in C containing threads is eased since at the lowest level Ada tasks and C threads map onto the same underlying kernel concept. -@item +@item When an Ada task is blocked during I/O the remaining Ada tasks are able to proceed. -@item +@item On multiprocessor systems Ada tasks can execute in parallel. @end itemize -@noindent Some threads libraries offer a mechanism to fork a new process, with the child process duplicating the threads from the parent. GNAT does not support this functionality when the parent contains more than one task. -@cindex Forking a new process +.. index:: Forking a new process -@node Ensuring Compliance with the Real-Time Annex +@node Ensuring Compliance with the Real-Time Annex,,Mapping Ada Tasks onto the Underlying Kernel Threads,GNAT Implementation of Tasking +@anchor{gnat_rm/implementation_of_specific_ada_features id5}@anchor{3b1}@anchor{gnat_rm/implementation_of_specific_ada_features ensuring-compliance-with-the-real-time-annex}@anchor{3b2} @subsection Ensuring Compliance with the Real-Time Annex -@cindex Real-Time Systems Annex compliance -@noindent + +@geindex Real-Time Systems Annex compliance + Although mapping Ada tasks onto the underlying threads has significant advantages, it does create some complications when it comes to respecting the scheduling semantics specified in the real-time annex (Annex D). -For instance the Annex D requirement for the @code{FIFO_Within_Priorities} +For instance the Annex D requirement for the @cite{FIFO_Within_Priorities} scheduling policy states: @quotation + @emph{When the active priority of a ready task that is not running changes, or the setting of its base priority takes effect, the task is removed from the ready queue for its old active priority @@ -21341,7 +24711,6 @@ due to the loss of inherited priority, in which case the task is added at the head of the ready queue for its new active priority.} @end quotation -@noindent While most kernels do put tasks at the end of the priority queue when a task changes its priority, (which respects the main FIFO_Within_Priorities requirement), almost none keep a thread at the @@ -21365,74 +24734,77 @@ Note that this simple scheme preserves the relative order of the tasks that were ready to execute in the priority queue where R has been placed at the end. -@node GNAT Implementation of Shared Passive Packages +@node GNAT Implementation of Shared Passive Packages,Code Generation for Array Aggregates,GNAT Implementation of Tasking,Implementation of Specific Ada Features +@anchor{gnat_rm/implementation_of_specific_ada_features id6}@anchor{3b3}@anchor{gnat_rm/implementation_of_specific_ada_features gnat-implementation-of-shared-passive-packages}@anchor{3b4} @section GNAT Implementation of Shared Passive Packages -@cindex Shared passive packages -@noindent -GNAT fully implements the pragma @code{Shared_Passive} for -@cindex pragma @code{Shared_Passive} + +@geindex Shared passive packages + +GNAT fully implements the pragma @cite{Shared_Passive} for +.. index:: pragma @cite{Shared_Passive} + the purpose of designating shared passive packages. This allows the use of passive partitions in the context described in the Ada Reference Manual; i.e., for communication between separate partitions of a distributed application using the features in Annex E. -@cindex Annex E -@cindex Distribution Systems Annex +.. index:: Annex E + +@geindex Distribution Systems Annex However, the implementation approach used by GNAT provides for more extensive usage as follows: -@table @emph -@item Communication between separate programs + +@table @asis + +@item @emph{Communication between separate programs} This allows separate programs to access the data in passive partitions, using protected objects for synchronization where needed. The only requirement is that the two programs have a common shared file system. It is even possible for programs running on different machines with different architectures -(e.g.@: different endianness) to communicate via the data in +(e.g., different endianness) to communicate via the data in a passive partition. -@item Persistence between program runs +@item @emph{Persistence between program runs} The data in a passive package can persist from one run of a program to another, so that a later program sees the final values stored by a previous run of the same program. - @end table -@noindent The implementation approach used is to store the data in files. A separate stream file is created for each object in the package, and an access to an object causes the corresponding file to be read or written. -The environment variable @code{SHARED_MEMORY_DIRECTORY} should be -@cindex @code{SHARED_MEMORY_DIRECTORY} environment variable +@geindex SHARED_MEMORY_DIRECTORY environment variable + +The environment variable @cite{SHARED_MEMORY_DIRECTORY} should be set to the directory to be used for these files. The files in this directory have names that correspond to their fully qualified names. For example, if we have the package -@smallexample @c ada +@example package X is pragma Shared_Passive (X); Y : Integer; Z : Float; end X; -@end smallexample +@end example -@noindent -and the environment variable is set to @code{/stemp/}, then the files created +and the environment variable is set to @cite{/stemp/}, then the files created will have the names: -@smallexample +@example /stemp/x.y /stemp/x.z -@end smallexample +@end example -@noindent These files are created when a value is initially written to the object, and the files are retained until manually deleted. This provides the persistence semantics. If no file exists, it means that no partition has assigned a value @@ -21441,7 +24813,7 @@ will be used. This model ensures that there are no issues in synchronizing the elaboration process, since elaboration of passive packages elaborates the initial values, but does not create the files. -The files are written using normal @code{Stream_IO} access. +The files are written using normal @cite{Stream_IO} access. If you want to be able to communicate between programs or partitions running on different architectures, then you should use the XDR versions of the stream attribute @@ -21450,27 +24822,22 @@ routines, since these are architecture independent. If active synchronization is required for access to the variables in the shared passive package, then as described in the Ada Reference Manual, the package may contain protected objects used for this purpose. In this case -a lock file (whose name is @file{___lock} (three underscores) +a lock file (whose name is @code{___lock} (three underscores) is created in the shared memory directory. -@cindex @file{___lock} file (for shared passive packages) + +@geindex ___lock file (for shared passive packages) + This is used to provide the required locking semantics for proper protected object synchronization. -As of January 2003, GNAT supports shared passive packages on all platforms +GNAT supports shared passive packages on all platforms except for OpenVMS. -@node Code Generation for Array Aggregates +@node Code Generation for Array Aggregates,The Size of Discriminated Records with Default Discriminants,GNAT Implementation of Shared Passive Packages,Implementation of Specific Ada Features +@anchor{gnat_rm/implementation_of_specific_ada_features code-generation-for-array-aggregates}@anchor{3b5}@anchor{gnat_rm/implementation_of_specific_ada_features id7}@anchor{3b6} @section Code Generation for Array Aggregates -@menu -* Static constant aggregates with static bounds:: -* Constant aggregates with unconstrained nominal types:: -* Aggregates with static bounds:: -* Aggregates with non-static bounds:: -* Aggregates in assignment statements:: -@end menu -@noindent Aggregates have a rich syntax and allow the user to specify the values of complex data structures by means of a single construct. As a result, the code generated for aggregates can be quite complex and involve loops, case @@ -21488,158 +24855,168 @@ and the type. In the context of an object declaration the code generated is generally simpler than in the case of an assignment. As a general rule, static component values and static subtypes also lead to simpler code. -@node Static constant aggregates with static bounds +@menu +* Static constant aggregates with static bounds:: +* Constant aggregates with unconstrained nominal types:: +* Aggregates with static bounds:: +* Aggregates with non-static bounds:: +* Aggregates in assignment statements:: + +@end menu + +@node Static constant aggregates with static bounds,Constant aggregates with unconstrained nominal types,,Code Generation for Array Aggregates +@anchor{gnat_rm/implementation_of_specific_ada_features static-constant-aggregates-with-static-bounds}@anchor{3b7}@anchor{gnat_rm/implementation_of_specific_ada_features id8}@anchor{3b8} @subsection Static constant aggregates with static bounds -@noindent + For the declarations: -@smallexample @c ada - type One_Dim is array (1..10) of integer; - ar0 : constant One_Dim := (1, 2, 3, 4, 5, 6, 7, 8, 9, 0); -@end smallexample -@noindent +@example +type One_Dim is array (1..10) of integer; +ar0 : constant One_Dim := (1, 2, 3, 4, 5, 6, 7, 8, 9, 0); +@end example + GNAT generates no executable code: the constant ar0 is placed in static memory. The same is true for constant aggregates with named associations: -@smallexample @c ada - Cr1 : constant One_Dim := (4 => 16, 2 => 4, 3 => 9, 1 => 1, 5 .. 10 => 0); - Cr3 : constant One_Dim := (others => 7777); -@end smallexample +@example +Cr1 : constant One_Dim := (4 => 16, 2 => 4, 3 => 9, 1 => 1, 5 .. 10 => 0); +Cr3 : constant One_Dim := (others => 7777); +@end example -@noindent The same is true for multidimensional constant arrays such as: -@smallexample @c ada - type two_dim is array (1..3, 1..3) of integer; - Unit : constant two_dim := ( (1,0,0), (0,1,0), (0,0,1)); -@end smallexample +@example +type two_dim is array (1..3, 1..3) of integer; +Unit : constant two_dim := ( (1,0,0), (0,1,0), (0,0,1)); +@end example -@noindent The same is true for arrays of one-dimensional arrays: the following are static: -@smallexample @c ada +@example type ar1b is array (1..3) of boolean; type ar_ar is array (1..3) of ar1b; None : constant ar1b := (others => false); -- fully static None2 : constant ar_ar := (1..3 => None); -- fully static -@end smallexample +@end example -@noindent However, for multidimensional aggregates with named associations, GNAT will generate assignments and loops, even if all associations are static. The following two declarations generate a loop for the first dimension, and individual component assignments for the second dimension: -@smallexample @c ada +@example Zero1: constant two_dim := (1..3 => (1..3 => 0)); Zero2: constant two_dim := (others => (others => 0)); -@end smallexample +@end example -@node Constant aggregates with unconstrained nominal types +@node Constant aggregates with unconstrained nominal types,Aggregates with static bounds,Static constant aggregates with static bounds,Code Generation for Array Aggregates +@anchor{gnat_rm/implementation_of_specific_ada_features constant-aggregates-with-unconstrained-nominal-types}@anchor{3b9}@anchor{gnat_rm/implementation_of_specific_ada_features id9}@anchor{3ba} @subsection Constant aggregates with unconstrained nominal types -@noindent + In such cases the aggregate itself establishes the subtype, so that -associations with @code{others} cannot be used. GNAT determines the +associations with @cite{others} cannot be used. GNAT determines the bounds for the actual subtype of the aggregate, and allocates the aggregate statically as well. No code is generated for the following: -@smallexample @c ada - type One_Unc is array (natural range <>) of integer; - Cr_Unc : constant One_Unc := (12,24,36); -@end smallexample +@example +type One_Unc is array (natural range <>) of integer; +Cr_Unc : constant One_Unc := (12,24,36); +@end example -@node Aggregates with static bounds +@node Aggregates with static bounds,Aggregates with non-static bounds,Constant aggregates with unconstrained nominal types,Code Generation for Array Aggregates +@anchor{gnat_rm/implementation_of_specific_ada_features id10}@anchor{3bb}@anchor{gnat_rm/implementation_of_specific_ada_features aggregates-with-static-bounds}@anchor{3bc} @subsection Aggregates with static bounds -@noindent + In all previous examples the aggregate was the initial (and immutable) value of a constant. If the aggregate initializes a variable, then code is generated for it as a combination of individual assignments and loops over the target object. The declarations -@smallexample @c ada - Cr_Var1 : One_Dim := (2, 5, 7, 11, 0, 0, 0, 0, 0, 0); - Cr_Var2 : One_Dim := (others > -1); -@end smallexample +@example +Cr_Var1 : One_Dim := (2, 5, 7, 11, 0, 0, 0, 0, 0, 0); +Cr_Var2 : One_Dim := (others > -1); +@end example -@noindent generate the equivalent of -@smallexample @c ada - Cr_Var1 (1) := 2; - Cr_Var1 (2) := 3; - Cr_Var1 (3) := 5; - Cr_Var1 (4) := 11; +@example +Cr_Var1 (1) := 2; +Cr_Var1 (2) := 3; +Cr_Var1 (3) := 5; +Cr_Var1 (4) := 11; - for I in Cr_Var2'range loop - Cr_Var2 (I) := -1; - end loop; -@end smallexample +for I in Cr_Var2'range loop + Cr_Var2 (I) := -1; +end loop; +@end example -@node Aggregates with non-static bounds +@node Aggregates with non-static bounds,Aggregates in assignment statements,Aggregates with static bounds,Code Generation for Array Aggregates +@anchor{gnat_rm/implementation_of_specific_ada_features aggregates-with-non-static-bounds}@anchor{3bd}@anchor{gnat_rm/implementation_of_specific_ada_features id11}@anchor{3be} @subsection Aggregates with non-static bounds -@noindent + If the bounds of the aggregate are not statically compatible with the bounds of the nominal subtype of the target, then constraint checks have to be generated on the bounds. For a multidimensional array, constraint checks may have to be applied to sub-arrays individually, if they do not have statically compatible subtypes. -@node Aggregates in assignment statements +@node Aggregates in assignment statements,,Aggregates with non-static bounds,Code Generation for Array Aggregates +@anchor{gnat_rm/implementation_of_specific_ada_features id12}@anchor{3bf}@anchor{gnat_rm/implementation_of_specific_ada_features aggregates-in-assignment-statements}@anchor{3c0} @subsection Aggregates in assignment statements -@noindent + In general, aggregate assignment requires the construction of a temporary, and a copy from the temporary to the target of the assignment. This is because it is not always possible to convert the assignment into a series of individual component assignments. For example, consider the simple case: -@smallexample @c ada - A := (A(2), A(1)); -@end smallexample +@example +A := (A(2), A(1)); +@end example -@noindent This cannot be converted into: -@smallexample @c ada - A(1) := A(2); - A(2) := A(1); -@end smallexample +@example +A(1) := A(2); +A(2) := A(1); +@end example -@noindent So the aggregate has to be built first in a separate location, and then copied into the target. GNAT recognizes simple cases where this intermediate step is not required, and the assignments can be performed in place, directly into the target. The following sufficient criteria are applied: -@itemize @bullet -@item + +@itemize * + +@item The bounds of the aggregate are static, and the associations are static. -@item + +@item The components of the aggregate are static constants, names of simple variables that are not renamings, or expressions not involving indexed components whose operands obey these rules. @end itemize -@noindent If any of these conditions are violated, the aggregate will be built in a temporary (created either by the front-end or the code generator) and then that temporary will be copied onto the target. -@node The Size of Discriminated Records with Default Discriminants +@node The Size of Discriminated Records with Default Discriminants,Strict Conformance to the Ada Reference Manual,Code Generation for Array Aggregates,Implementation of Specific Ada Features +@anchor{gnat_rm/implementation_of_specific_ada_features id13}@anchor{3c1}@anchor{gnat_rm/implementation_of_specific_ada_features the-size-of-discriminated-records-with-default-discriminants}@anchor{3c2} @section The Size of Discriminated Records with Default Discriminants -@noindent -If a discriminated type @code{T} has discriminants with default values, it is + +If a discriminated type @cite{T} has discriminants with default values, it is possible to declare an object of this type without providing an explicit constraint: -@smallexample @c ada -@group +@example type Size is range 1..100; type Rec (D : Size := 15) is record @@ -21647,35 +25024,30 @@ type Rec (D : Size := 15) is record end T; Word : Rec; -@end group -@end smallexample +@end example -@noindent Such an object is said to be @emph{unconstrained}. The discriminant of the object can be modified by a full assignment to the object, as long as it preserves the relation between the value of the discriminant, and the value of the components that depend on it: -@smallexample @c ada -@group +@example Word := (3, "yes"); Word := (5, "maybe"); Word := (5, "no"); -- raises Constraint_Error -@end group -@end smallexample +@end example -@noindent In order to support this behavior efficiently, an unconstrained object is given the maximum size that any value of the type requires. In the case -above, @code{Word} has storage for the discriminant and for -a @code{String} of length 100. +above, @cite{Word} has storage for the discriminant and for +a @cite{String} of length 100. It is important to note that unconstrained objects do not require dynamic allocation. It would be an improper implementation to place on the heap those components whose size depends on discriminants. (This improper implementation -was used by some Ada83 compilers, where the @code{Name} component above +was used by some Ada83 compilers, where the @cite{Name} component above would have been stored as a pointer to a dynamic string). Following the principle that dynamic storage management should never be introduced implicitly, @@ -21685,31 +25057,28 @@ object, and place it on the stack. This maximum size approach has been a source of surprise to some users, who expect the default values of the discriminants to determine the size reserved for an -unconstrained object: ``If the default is 15, why should the object occupy -a larger size?'' +unconstrained object: "If the default is 15, why should the object occupy +a larger size?" The answer, of course, is that the discriminant may be later modified, and its full range of values must be taken into account. This is why the declaration: -@smallexample -@group +@example type Rec (D : Positive := 15) is record Name : String (1..D); end record; Too_Large : Rec; -@end group -@end smallexample +@end example -@noindent is flagged by the compiler with a warning: -an attempt to create @code{Too_Large} will raise @code{Storage_Error}, -because the required size includes @code{Positive'Last} +an attempt to create @cite{Too_Large} will raise @cite{Storage_Error}, +because the required size includes @cite{Positive'Last} bytes. As the first example indicates, the proper approach is to declare an -index type of ``reasonable'' range so that unconstrained objects are not too +index type of 'reasonable' range so that unconstrained objects are not too large. -One final wrinkle: if the object is declared to be @code{aliased}, or if it is +One final wrinkle: if the object is declared to be @cite{aliased}, or if it is created in the heap by means of an allocator, then it is @emph{not} unconstrained: it is constrained by the default values of the discriminants, and those values @@ -21718,10 +25087,11 @@ aliasing all views of the object (which may be manipulated by different tasks, say) must be consistent, so it is imperative that the object, once created, remain invariant. -@node Strict Conformance to the Ada Reference Manual +@node Strict Conformance to the Ada Reference Manual,,The Size of Discriminated Records with Default Discriminants,Implementation of Specific Ada Features +@anchor{gnat_rm/implementation_of_specific_ada_features strict-conformance-to-the-ada-reference-manual}@anchor{3c3}@anchor{gnat_rm/implementation_of_specific_ada_features id14}@anchor{3c4} @section Strict Conformance to the Ada Reference Manual -@noindent + The dynamic semantics defined by the Ada Reference Manual impose a set of run-time checks to be generated. By default, the GNAT compiler will insert many run-time checks into the compiled code, including most of those required by the @@ -21733,32 +25103,39 @@ systems do not perform this check by default). Strict conformance to the Ada Reference Manual can be achieved by adding three compiler options for overflow checking for integer operations -(@option{-gnato}), dynamic checks for access-before-elaboration on subprogram -calls and generic instantiations (@option{-gnatE}), and stack overflow -checking (@option{-fstack-check}). +(@emph{-gnato}), dynamic checks for access-before-elaboration on subprogram +calls and generic instantiations (@emph{-gnatE}), and stack overflow +checking (@emph{-fstack-check}). Note that the result of a floating point arithmetic operation in overflow and -invalid situations, when the @code{Machine_Overflows} attribute of the result -type is @code{False}, is to generate IEEE NaN and infinite values. This is the +invalid situations, when the @cite{Machine_Overflows} attribute of the result +type is @cite{False}, is to generate IEEE NaN and infinite values. This is the case for machines compliant with the IEEE floating-point standard, but on machines that are not fully compliant with this standard, such as Alpha, the -@option{-mieee} compiler flag must be used for achieving IEEE confirming +@emph{-mieee} compiler flag must be used for achieving IEEE confirming behavior (although at the cost of a significant performance penalty), so infinite and NaN values are properly generated. - -@node Implementation of Ada 2012 Features +@node Implementation of Ada 2012 Features,Obsolescent Features,Implementation of Specific Ada Features,Top +@anchor{gnat_rm/implementation_of_ada_2012_features doc}@anchor{3c5}@anchor{gnat_rm/implementation_of_ada_2012_features implementation-of-ada-2012-features}@anchor{14}@anchor{gnat_rm/implementation_of_ada_2012_features id1}@anchor{3c6} @chapter Implementation of Ada 2012 Features -@cindex Ada 2012 implementation status + + +@geindex Ada 2012 implementation status + +@geindex -gnat12 option (gcc) + +@geindex pragma Ada_2012 + +@geindex configuration pragma Ada_2012 + +@geindex Ada_2012 configuration pragma This chapter contains a complete list of Ada 2012 features that have been implemented as of GNAT version 6.4. Generally, these features are only -available if the @option{-gnat12} (Ada 2012 features enabled) flag is set -@cindex @option{-gnat12} option -or if the configuration pragma @code{Ada_2012} is used. -@cindex pragma @code{Ada_2012} -@cindex configuration pragma @code{Ada_2012} -@cindex @code{Ada_2012} configuration pragma +available if the @emph{-gnat12} (Ada 2012 features enabled) flag is set +or if the configuration pragma @cite{Ada_2012} is used. + However, new pragmas, attributes, and restrictions are unconditionally available, since the Ada 95 standard allows the addition of new pragmas, attributes, and restrictions (there are exceptions, which are @@ -21772,1617 +25149,2162 @@ subsequent releases. A date of 0000-00-00 means that GNAT has always implemented the feature, or implemented it as soon as it appeared as a binding interpretation. -Each feature corresponds to an Ada Issue (``AI'') approved by the Ada +Each feature corresponds to an Ada Issue ('AI') approved by the Ada standardization group (ISO/IEC JTC1/SC22/WG9) for inclusion in Ada 2012. The features are ordered based on the relevant sections of the Ada -Reference Manual (``RM''). When a given AI relates to multiple points +Reference Manual ("RM"). When a given AI relates to multiple points in the RM, the earliest is used. A complete description of the AIs may be found in -@url{www.ada-auth.org/ai05-summary.html}. +@indicateurl{http://www.ada-auth.org/ai05-summary.html}. -@itemize @bullet +@geindex AI-0176 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0176 Quantified expressions (2010-09-29)} -@cindex AI-0176 (Ada 2012 feature) -@noindent - Both universally and existentially quantified expressions are implemented. - They use the new syntax for iterators proposed in AI05-139-2, as well as - the standard Ada loop syntax. +Both universally and existentially quantified expressions are implemented. +They use the new syntax for iterators proposed in AI05-139-2, as well as +the standard Ada loop syntax. + +RM References: 1.01.04 (12) 2.09 (2/2) 4.04 (7) 4.05.09 (0) +@end itemize + +@geindex AI-0079 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0079 Allow other_format characters in source (2010-07-10)} + +Wide characters in the unicode category @emph{other_format} are now allowed in +source programs between tokens, but not within a token such as an identifier. + +RM References: 2.01 (4/2) 2.02 (7) +@end itemize + +@geindex AI-0091 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0091 Do not allow other_format in identifiers (0000-00-00)} + +Wide characters in the unicode category @emph{other_format} are not permitted +within an identifier, since this can be a security problem. The error +message for this case has been improved to be more specific, but GNAT has +never allowed such characters to appear in identifiers. + +RM References: 2.03 (3.1/2) 2.03 (4/2) 2.03 (5/2) 2.03 (5.1/2) 2.03 (5.2/2) 2.03 (5.3/2) 2.09 (2/2) +@end itemize + +@geindex AI-0100 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0100 Placement of pragmas (2010-07-01)} + +This AI is an earlier version of AI-163. It simplifies the rules +for legal placement of pragmas. In the case of lists that allow pragmas, if +the list may have no elements, then the list may consist solely of pragmas. + +RM References: 2.08 (7) +@end itemize + +@geindex AI-0163 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0163 Pragmas in place of null (2010-07-01)} + +A statement sequence may be composed entirely of pragmas. It is no longer +necessary to add a dummy @cite{null} statement to make the sequence legal. + +RM References: 2.08 (7) 2.08 (16) +@end itemize + +@geindex AI-0080 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0080 'View of' not needed if clear from context (0000-00-00)} -@noindent - RM References: 1.01.04 (12) 2.09 (2/2) 4.04 (7) 4.05.09 (0) +This is an editorial change only, described as non-testable in the AI. + +RM References: 3.01 (7) +@end itemize + +@geindex AI-0183 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0183 Aspect specifications (2010-08-16)} + +Aspect specifications have been fully implemented except for pre and post- +conditions, and type invariants, which have their own separate AI's. All +forms of declarations listed in the AI are supported. The following is a +list of the aspects supported (with GNAT implementation aspects marked) +@end itemize + + +@multitable {xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx} {xxxxxxxxxxxxx} +@headitem + +Supported Aspect + +@tab + +Source @item -@emph{AI-0079 Allow @i{other_format} characters in source (2010-07-10)} -@cindex AI-0079 (Ada 2012 feature) -@noindent - Wide characters in the unicode category @i{other_format} are now allowed in - source programs between tokens, but not within a token such as an identifier. +@cite{Ada_2005} + +@tab -@noindent - RM References: 2.01 (4/2) 2.02 (7) +-- GNAT @item -@emph{AI-0091 Do not allow @i{other_format} in identifiers (0000-00-00)} -@cindex AI-0091 (Ada 2012 feature) -@noindent - Wide characters in the unicode category @i{other_format} are not permitted - within an identifier, since this can be a security problem. The error - message for this case has been improved to be more specific, but GNAT has - never allowed such characters to appear in identifiers. +@cite{Ada_2012} -@noindent - RM References: 2.03 (3.1/2) 2.03 (4/2) 2.03 (5/2) 2.03 (5.1/2) 2.03 (5.2/2) 2.03 (5.3/2) 2.09 (2/2) +@tab + +-- GNAT @item -@emph{AI-0100 Placement of pragmas (2010-07-01)} -@cindex AI-0100 (Ada 2012 feature) -@noindent - This AI is an earlier version of AI-163. It simplifies the rules - for legal placement of pragmas. In the case of lists that allow pragmas, if - the list may have no elements, then the list may consist solely of pragmas. +@cite{Address} -@noindent - RM References: 2.08 (7) +@tab @item -@emph{AI-0163 Pragmas in place of null (2010-07-01)} -@cindex AI-0163 (Ada 2012 feature) -@noindent - A statement sequence may be composed entirely of pragmas. It is no longer - necessary to add a dummy @code{null} statement to make the sequence legal. +@cite{Alignment} + +@tab + +@item + +@cite{Atomic} + +@tab -@noindent - RM References: 2.08 (7) 2.08 (16) +@item + +@cite{Atomic_Components} +@tab @item -@emph{AI-0080 ``View of'' not needed if clear from context (0000-00-00)} -@cindex AI-0080 (Ada 2012 feature) -@noindent - This is an editorial change only, described as non-testable in the AI. +@cite{Bit_Order} + +@tab -@noindent - RM References: 3.01 (7) +@item + +@cite{Component_Size} +@tab @item -@emph{AI-0183 Aspect specifications (2010-08-16)} -@cindex AI-0183 (Ada 2012 feature) - -@noindent - Aspect specifications have been fully implemented except for pre and post- - conditions, and type invariants, which have their own separate AI's. All - forms of declarations listed in the AI are supported. The following is a - list of the aspects supported (with GNAT implementation aspects marked) - -@multitable {@code{Preelaborable_Initialization}} {--GNAT} -@item @code{Ada_2005} @tab -- GNAT -@item @code{Ada_2012} @tab -- GNAT -@item @code{Address} @tab -@item @code{Alignment} @tab -@item @code{Atomic} @tab -@item @code{Atomic_Components} @tab -@item @code{Bit_Order} @tab -@item @code{Component_Size} @tab -@item @code{Contract_Cases} @tab -- GNAT -@item @code{Discard_Names} @tab -@item @code{External_Tag} @tab -@item @code{Favor_Top_Level} @tab -- GNAT -@item @code{Inline} @tab -@item @code{Inline_Always} @tab -- GNAT -@item @code{Invariant} @tab -- GNAT -@item @code{Machine_Radix} @tab -@item @code{No_Return} @tab -@item @code{Object_Size} @tab -- GNAT -@item @code{Pack} @tab -@item @code{Persistent_BSS} @tab -- GNAT -@item @code{Post} @tab -@item @code{Pre} @tab -@item @code{Predicate} @tab -@item @code{Preelaborable_Initialization} @tab -@item @code{Pure_Function} @tab -- GNAT -@item @code{Remote_Access_Type} @tab -- GNAT -@item @code{Shared} @tab -- GNAT -@item @code{Size} @tab -@item @code{Storage_Pool} @tab -@item @code{Storage_Size} @tab -@item @code{Stream_Size} @tab -@item @code{Suppress} @tab -@item @code{Suppress_Debug_Info} @tab -- GNAT -@item @code{Test_Case} @tab -- GNAT -@item @code{Thread_Local_Storage} @tab -- GNAT -@item @code{Type_Invariant} @tab -@item @code{Unchecked_Union} @tab -@item @code{Universal_Aliasing} @tab -- GNAT -@item @code{Unmodified} @tab -- GNAT -@item @code{Unreferenced} @tab -- GNAT -@item @code{Unreferenced_Objects} @tab -- GNAT -@item @code{Unsuppress} @tab -@item @code{Value_Size} @tab -- GNAT -@item @code{Volatile} @tab -@item @code{Volatile_Components} -@item @code{Warnings} @tab -- GNAT -@end multitable -@noindent - Note that for aspects with an expression, e.g. @code{Size}, the expression is - treated like a default expression (visibility is analyzed at the point of - occurrence of the aspect, but evaluation of the expression occurs at the - freeze point of the entity involved). +@cite{Contract_Cases} -@noindent - RM References: 3.02.01 (3) 3.02.02 (2) 3.03.01 (2/2) 3.08 (6) - 3.09.03 (1.1/2) 6.01 (2/2) 6.07 (2/2) 9.05.02 (2/2) 7.01 (3) 7.03 - (2) 7.03 (3) 9.01 (2/2) 9.01 (3/2) 9.04 (2/2) 9.04 (3/2) - 9.05.02 (2/2) 11.01 (2) 12.01 (3) 12.03 (2/2) 12.04 (2/2) 12.05 (2) - 12.06 (2.1/2) 12.06 (2.2/2) 12.07 (2) 13.01 (0.1/2) 13.03 (5/1) - 13.03.01 (0) +@tab +-- GNAT @item -@emph{AI-0128 Inequality is a primitive operation (0000-00-00)} -@cindex AI-0128 (Ada 2012 feature) -@noindent - If an equality operator ("=") is declared for a type, then the implicitly - declared inequality operator ("/=") is a primitive operation of the type. - This is the only reasonable interpretation, and is the one always implemented - by GNAT, but the RM was not entirely clear in making this point. +@cite{Discard_Names} -@noindent - RM References: 3.02.03 (6) 6.06 (6) +@tab @item -@emph{AI-0003 Qualified expressions as names (2010-07-11)} -@cindex AI-0003 (Ada 2012 feature) -@noindent - In Ada 2012, a qualified expression is considered to be syntactically a name, - meaning that constructs such as @code{A'(F(X)).B} are now legal. This is - useful in disambiguating some cases of overloading. +@cite{External_Tag} -@noindent - RM References: 3.03 (11) 3.03 (21) 4.01 (2) 4.04 (7) 4.07 (3) - 5.04 (7) +@tab @item -@emph{AI-0120 Constant instance of protected object (0000-00-00)} -@cindex AI-0120 (Ada 2012 feature) -@noindent - This is an RM editorial change only. The section that lists objects that are - constant failed to include the current instance of a protected object - within a protected function. This has always been treated as a constant - in GNAT. +@cite{Favor_Top_Level} + +@tab -@noindent - RM References: 3.03 (21) +-- GNAT @item -@emph{AI-0008 General access to constrained objects (0000-00-00)} -@cindex AI-0008 (Ada 2012 feature) -@noindent - The wording in the RM implied that if you have a general access to a - constrained object, it could be used to modify the discriminants. This was - obviously not intended. @code{Constraint_Error} should be raised, and GNAT - has always done so in this situation. +@cite{Inline} -@noindent - RM References: 3.03 (23) 3.10.02 (26/2) 4.01 (9) 6.04.01 (17) 8.05.01 (5/2) +@tab +@item + +@cite{Inline_Always} + +@tab + +-- GNAT @item -@emph{AI-0093 Additional rules use immutably limited (0000-00-00)} -@cindex AI-0093 (Ada 2012 feature) -@noindent - This is an editorial change only, to make more widespread use of the Ada 2012 - ``immutably limited''. +@cite{Invariant} -@noindent - RM References: 3.03 (23.4/3) +@tab +-- GNAT +@item + +@cite{Machine_Radix} + +@tab @item -@emph{AI-0096 Deriving from formal private types (2010-07-20)} -@cindex AI-0096 (Ada 2012 feature) -@noindent - In general it is illegal for a type derived from a formal limited type to be - nonlimited. This AI makes an exception to this rule: derivation is legal - if it appears in the private part of the generic, and the formal type is not - tagged. If the type is tagged, the legality check must be applied to the - private part of the package. +@cite{No_Return} -@noindent - RM References: 3.04 (5.1/2) 6.02 (7) +@tab + +@item +@cite{Object_Size} + +@tab + +-- GNAT + +@item + +@cite{Pack} + +@tab @item -@emph{AI-0181 Soft hyphen is a non-graphic character (2010-07-23)} -@cindex AI-0181 (Ada 2012 feature) -@noindent - From Ada 2005 on, soft hyphen is considered a non-graphic character, which - means that it has a special name (@code{SOFT_HYPHEN}) in conjunction with the - @code{Image} and @code{Value} attributes for the character types. Strictly - speaking this is an inconsistency with Ada 95, but in practice the use of - these attributes is so obscure that it will not cause problems. +@cite{Persistent_BSS} -@noindent - RM References: 3.05.02 (2/2) A.01 (35/2) A.03.03 (21) +@tab +-- GNAT @item -@emph{AI-0182 Additional forms for @code{Character'Value} (0000-00-00)} -@cindex AI-0182 (Ada 2012 feature) -@noindent - This AI allows @code{Character'Value} to accept the string @code{'?'} where - @code{?} is any character including non-graphic control characters. GNAT has - always accepted such strings. It also allows strings such as - @code{HEX_00000041} to be accepted, but GNAT does not take advantage of this - permission and raises @code{Constraint_Error}, as is certainly still - permitted. +@cite{Post} + +@tab + +@item -@noindent - RM References: 3.05 (56/2) +@cite{Pre} +@tab @item -@emph{AI-0214 Defaulted discriminants for limited tagged (2010-10-01)} -@cindex AI-0214 (Ada 2012 feature) -@noindent - Ada 2012 relaxes the restriction that forbids discriminants of tagged types - to have default expressions by allowing them when the type is limited. It - is often useful to define a default value for a discriminant even though - it can't be changed by assignment. +@cite{Predicate} -@noindent - RM References: 3.07 (9.1/2) 3.07.02 (3) +@tab +@item + +@cite{Preelaborable_Initialization} + +@tab @item -@emph{AI-0102 Some implicit conversions are illegal (0000-00-00)} -@cindex AI-0102 (Ada 2012 feature) -@noindent - It is illegal to assign an anonymous access constant to an anonymous access - variable. The RM did not have a clear rule to prevent this, but GNAT has - always generated an error for this usage. +@cite{Pure_Function} -@noindent - RM References: 3.07 (16) 3.07.01 (9) 6.04.01 (6) 8.06 (27/2) +@tab +-- GNAT @item -@emph{AI-0158 Generalizing membership tests (2010-09-16)} -@cindex AI-0158 (Ada 2012 feature) -@noindent - This AI extends the syntax of membership tests to simplify complex conditions - that can be expressed as membership in a subset of values of any type. It - introduces syntax for a list of expressions that may be used in loop contexts - as well. +@cite{Remote_Access_Type} -@noindent - RM References: 3.08.01 (5) 4.04 (3) 4.05.02 (3) 4.05.02 (5) 4.05.02 (27) +@tab +-- GNAT @item -@emph{AI-0173 Testing if tags represent abstract types (2010-07-03)} -@cindex AI-0173 (Ada 2012 feature) -@noindent - The function @code{Ada.Tags.Type_Is_Abstract} returns @code{True} if invoked - with the tag of an abstract type, and @code{False} otherwise. +@cite{Shared} -@noindent - RM References: 3.09 (7.4/2) 3.09 (12.4/2) +@tab +-- GNAT +@item + +@cite{Size} + +@tab @item -@emph{AI-0076 function with controlling result (0000-00-00)} -@cindex AI-0076 (Ada 2012 feature) -@noindent - This is an editorial change only. The RM defines calls with controlling - results, but uses the term ``function with controlling result'' without an - explicit definition. +@cite{Storage_Pool} -@noindent - RM References: 3.09.02 (2/2) +@tab + +@item +@cite{Storage_Size} + +@tab @item -@emph{AI-0126 Dispatching with no declared operation (0000-00-00)} -@cindex AI-0126 (Ada 2012 feature) -@noindent - This AI clarifies dispatching rules, and simply confirms that dispatching - executes the operation of the parent type when there is no explicitly or - implicitly declared operation for the descendant type. This has always been - the case in all versions of GNAT. +@cite{Stream_Size} + +@tab -@noindent - RM References: 3.09.02 (20/2) 3.09.02 (20.1/2) 3.09.02 (20.2/2) +@item + +@cite{Suppress} +@tab @item -@emph{AI-0097 Treatment of abstract null extension (2010-07-19)} -@cindex AI-0097 (Ada 2012 feature) -@noindent - The RM as written implied that in some cases it was possible to create an - object of an abstract type, by having an abstract extension inherit a non- - abstract constructor from its parent type. This mistake has been corrected - in GNAT and in the RM, and this construct is now illegal. +@cite{Suppress_Debug_Info} -@noindent - RM References: 3.09.03 (4/2) +@tab +-- GNAT @item -@emph{AI-0203 Extended return cannot be abstract (0000-00-00)} -@cindex AI-0203 (Ada 2012 feature) -@noindent - A return_subtype_indication cannot denote an abstract subtype. GNAT has never - permitted such usage. +@cite{Test_Case} -@noindent - RM References: 3.09.03 (8/3) +@tab +-- GNAT @item -@emph{AI-0198 Inheriting abstract operators (0000-00-00)} -@cindex AI-0198 (Ada 2012 feature) -@noindent - This AI resolves a conflict between two rules involving inherited abstract - operations and predefined operators. If a derived numeric type inherits - an abstract operator, it overrides the predefined one. This interpretation - was always the one implemented in GNAT. +@cite{Thread_Local_Storage} + +@tab -@noindent - RM References: 3.09.03 (4/3) +-- GNAT @item -@emph{AI-0073 Functions returning abstract types (2010-07-10)} -@cindex AI-0073 (Ada 2012 feature) -@noindent - This AI covers a number of issues regarding returning abstract types. In - particular generic functions cannot have abstract result types or access - result types designated an abstract type. There are some other cases which - are detailed in the AI. Note that this binding interpretation has not been - retrofitted to operate before Ada 2012 mode, since it caused a significant - number of regressions. +@cite{Type_Invariant} + +@tab -@noindent - RM References: 3.09.03 (8) 3.09.03 (10) 6.05 (8/2) +@item + +@cite{Unchecked_Union} +@tab @item -@emph{AI-0070 Elaboration of interface types (0000-00-00)} -@cindex AI-0070 (Ada 2012 feature) -@noindent - This is an editorial change only, there are no testable consequences short of - checking for the absence of generated code for an interface declaration. +@cite{Universal_Aliasing} -@noindent - RM References: 3.09.04 (18/2) +@tab +-- GNAT @item -@emph{AI-0208 Characteristics of incomplete views (0000-00-00)} -@cindex AI-0208 (Ada 2012 feature) -@noindent - The wording in the Ada 2005 RM concerning characteristics of incomplete views - was incorrect and implied that some programs intended to be legal were now - illegal. GNAT had never considered such programs illegal, so it has always - implemented the intent of this AI. +@cite{Unmodified} -@noindent - RM References: 3.10.01 (2.4/2) 3.10.01 (2.6/2) +@tab +-- GNAT @item -@emph{AI-0162 Incomplete type completed by partial view (2010-09-15)} -@cindex AI-0162 (Ada 2012 feature) -@noindent - Incomplete types are made more useful by allowing them to be completed by - private types and private extensions. +@cite{Unreferenced} -@noindent - RM References: 3.10.01 (2.5/2) 3.10.01 (2.6/2) 3.10.01 (3) 3.10.01 (4/2) +@tab +-- GNAT +@item + +@cite{Unreferenced_Objects} + +@tab + +-- GNAT @item -@emph{AI-0098 Anonymous subprogram access restrictions (0000-00-00)} -@cindex AI-0098 (Ada 2012 feature) -@noindent - An unintentional omission in the RM implied some inconsistent restrictions on - the use of anonymous access to subprogram values. These restrictions were not - intentional, and have never been enforced by GNAT. +@cite{Unsuppress} -@noindent - RM References: 3.10.01 (6) 3.10.01 (9.2/2) +@tab +@item + +@cite{Value_Size} + +@tab + +-- GNAT @item -@emph{AI-0199 Aggregate with anonymous access components (2010-07-14)} -@cindex AI-0199 (Ada 2012 feature) -@noindent - A choice list in a record aggregate can include several components of - (distinct) anonymous access types as long as they have matching designated - subtypes. +@cite{Volatile} + +@tab + +@item -@noindent - RM References: 4.03.01 (16) +@cite{Volatile_Components} +@tab @item + +@cite{Warnings} + +@tab + +-- GNAT + +@end multitable + + +@quotation + +Note that for aspects with an expression, e.g. @cite{Size}, the expression is +treated like a default expression (visibility is analyzed at the point of +occurrence of the aspect, but evaluation of the expression occurs at the +freeze point of the entity involved). + +RM References: 3.02.01 (3) 3.02.02 (2) 3.03.01 (2/2) 3.08 (6) +3.09.03 (1.1/2) 6.01 (2/2) 6.07 (2/2) 9.05.02 (2/2) 7.01 (3) 7.03 +(2) 7.03 (3) 9.01 (2/2) 9.01 (3/2) 9.04 (2/2) 9.04 (3/2) +9.05.02 (2/2) 11.01 (2) 12.01 (3) 12.03 (2/2) 12.04 (2/2) 12.05 (2) +12.06 (2.1/2) 12.06 (2.2/2) 12.07 (2) 13.01 (0.1/2) 13.03 (5/1) +13.03.01 (0) +@end quotation + +@geindex AI-0128 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0128 Inequality is a primitive operation (0000-00-00)} + +If an equality operator ("=") is declared for a type, then the implicitly +declared inequality operator ("/=") is a primitive operation of the type. +This is the only reasonable interpretation, and is the one always implemented +by GNAT, but the RM was not entirely clear in making this point. + +RM References: 3.02.03 (6) 6.06 (6) +@end itemize + +@geindex AI-0003 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0003 Qualified expressions as names (2010-07-11)} + +In Ada 2012, a qualified expression is considered to be syntactically a name, +meaning that constructs such as @cite{A'(F(X)).B} are now legal. This is +useful in disambiguating some cases of overloading. + +RM References: 3.03 (11) 3.03 (21) 4.01 (2) 4.04 (7) 4.07 (3) +5.04 (7) +@end itemize + +@geindex AI-0120 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0120 Constant instance of protected object (0000-00-00)} + +This is an RM editorial change only. The section that lists objects that are +constant failed to include the current instance of a protected object +within a protected function. This has always been treated as a constant +in GNAT. + +RM References: 3.03 (21) +@end itemize + +@geindex AI-0008 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0008 General access to constrained objects (0000-00-00)} + +The wording in the RM implied that if you have a general access to a +constrained object, it could be used to modify the discriminants. This was +obviously not intended. @cite{Constraint_Error} should be raised, and GNAT +has always done so in this situation. + +RM References: 3.03 (23) 3.10.02 (26/2) 4.01 (9) 6.04.01 (17) 8.05.01 (5/2) +@end itemize + +@geindex AI-0093 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0093 Additional rules use immutably limited (0000-00-00)} + +This is an editorial change only, to make more widespread use of the Ada 2012 +'immutably limited'. + +RM References: 3.03 (23.4/3) +@end itemize + +@geindex AI-0096 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0096 Deriving from formal private types (2010-07-20)} + +In general it is illegal for a type derived from a formal limited type to be +nonlimited. This AI makes an exception to this rule: derivation is legal +if it appears in the private part of the generic, and the formal type is not +tagged. If the type is tagged, the legality check must be applied to the +private part of the package. + +RM References: 3.04 (5.1/2) 6.02 (7) +@end itemize + +@geindex AI-0181 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0181 Soft hyphen is a non-graphic character (2010-07-23)} + +From Ada 2005 on, soft hyphen is considered a non-graphic character, which +means that it has a special name (@cite{SOFT_HYPHEN}) in conjunction with the +@cite{Image} and @cite{Value} attributes for the character types. Strictly +speaking this is an inconsistency with Ada 95, but in practice the use of +these attributes is so obscure that it will not cause problems. + +RM References: 3.05.02 (2/2) A.01 (35/2) A.03.03 (21) +@end itemize + +@geindex AI-0182 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0182 Additional forms for `Character'Value} (0000-00-00)` + +This AI allows @cite{Character'Value} to accept the string @cite{'?'} where +@cite{?} is any character including non-graphic control characters. GNAT has +always accepted such strings. It also allows strings such as +@cite{HEX_00000041} to be accepted, but GNAT does not take advantage of this +permission and raises @cite{Constraint_Error}, as is certainly still +permitted. + +RM References: 3.05 (56/2) +@end itemize + +@geindex AI-0214 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0214 Defaulted discriminants for limited tagged (2010-10-01)} + +Ada 2012 relaxes the restriction that forbids discriminants of tagged types +to have default expressions by allowing them when the type is limited. It +is often useful to define a default value for a discriminant even though +it can't be changed by assignment. + +RM References: 3.07 (9.1/2) 3.07.02 (3) +@end itemize + +@geindex AI-0102 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0102 Some implicit conversions are illegal (0000-00-00)} + +It is illegal to assign an anonymous access constant to an anonymous access +variable. The RM did not have a clear rule to prevent this, but GNAT has +always generated an error for this usage. + +RM References: 3.07 (16) 3.07.01 (9) 6.04.01 (6) 8.06 (27/2) +@end itemize + +@geindex AI-0158 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0158 Generalizing membership tests (2010-09-16)} + +This AI extends the syntax of membership tests to simplify complex conditions +that can be expressed as membership in a subset of values of any type. It +introduces syntax for a list of expressions that may be used in loop contexts +as well. + +RM References: 3.08.01 (5) 4.04 (3) 4.05.02 (3) 4.05.02 (5) 4.05.02 (27) +@end itemize + +@geindex AI-0173 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0173 Testing if tags represent abstract types (2010-07-03)} + +The function @cite{Ada.Tags.Type_Is_Abstract} returns @cite{True} if invoked +with the tag of an abstract type, and @cite{False} otherwise. + +RM References: 3.09 (7.4/2) 3.09 (12.4/2) +@end itemize + +@geindex AI-0076 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0076 function with controlling result (0000-00-00)} + +This is an editorial change only. The RM defines calls with controlling +results, but uses the term 'function with controlling result' without an +explicit definition. + +RM References: 3.09.02 (2/2) +@end itemize + +@geindex AI-0126 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0126 Dispatching with no declared operation (0000-00-00)} + +This AI clarifies dispatching rules, and simply confirms that dispatching +executes the operation of the parent type when there is no explicitly or +implicitly declared operation for the descendant type. This has always been +the case in all versions of GNAT. + +RM References: 3.09.02 (20/2) 3.09.02 (20.1/2) 3.09.02 (20.2/2) +@end itemize + +@geindex AI-0097 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0097 Treatment of abstract null extension (2010-07-19)} + +The RM as written implied that in some cases it was possible to create an +object of an abstract type, by having an abstract extension inherit a non- +abstract constructor from its parent type. This mistake has been corrected +in GNAT and in the RM, and this construct is now illegal. + +RM References: 3.09.03 (4/2) +@end itemize + +@geindex AI-0203 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0203 Extended return cannot be abstract (0000-00-00)} + +A return_subtype_indication cannot denote an abstract subtype. GNAT has never +permitted such usage. + +RM References: 3.09.03 (8/3) +@end itemize + +@geindex AI-0198 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0198 Inheriting abstract operators (0000-00-00)} + +This AI resolves a conflict between two rules involving inherited abstract +operations and predefined operators. If a derived numeric type inherits +an abstract operator, it overrides the predefined one. This interpretation +was always the one implemented in GNAT. + +RM References: 3.09.03 (4/3) +@end itemize + +@geindex AI-0073 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0073 Functions returning abstract types (2010-07-10)} + +This AI covers a number of issues regarding returning abstract types. In +particular generic functions cannot have abstract result types or access +result types designated an abstract type. There are some other cases which +are detailed in the AI. Note that this binding interpretation has not been +retrofitted to operate before Ada 2012 mode, since it caused a significant +number of regressions. + +RM References: 3.09.03 (8) 3.09.03 (10) 6.05 (8/2) +@end itemize + +@geindex AI-0070 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0070 Elaboration of interface types (0000-00-00)} + +This is an editorial change only, there are no testable consequences short of +checking for the absence of generated code for an interface declaration. + +RM References: 3.09.04 (18/2) +@end itemize + +@geindex AI-0208 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0208 Characteristics of incomplete views (0000-00-00)} + +The wording in the Ada 2005 RM concerning characteristics of incomplete views +was incorrect and implied that some programs intended to be legal were now +illegal. GNAT had never considered such programs illegal, so it has always +implemented the intent of this AI. + +RM References: 3.10.01 (2.4/2) 3.10.01 (2.6/2) +@end itemize + +@geindex AI-0162 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0162 Incomplete type completed by partial view (2010-09-15)} + +Incomplete types are made more useful by allowing them to be completed by +private types and private extensions. + +RM References: 3.10.01 (2.5/2) 3.10.01 (2.6/2) 3.10.01 (3) 3.10.01 (4/2) +@end itemize + +@geindex AI-0098 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0098 Anonymous subprogram access restrictions (0000-00-00)} + +An unintentional omission in the RM implied some inconsistent restrictions on +the use of anonymous access to subprogram values. These restrictions were not +intentional, and have never been enforced by GNAT. + +RM References: 3.10.01 (6) 3.10.01 (9.2/2) +@end itemize + +@geindex AI-0199 (Ada 2012 feature) + + +@itemize * + +@item +@emph{AI-0199 Aggregate with anonymous access components (2010-07-14)} + +A choice list in a record aggregate can include several components of +(distinct) anonymous access types as long as they have matching designated +subtypes. + +RM References: 4.03.01 (16) +@end itemize + +@geindex AI-0220 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0220 Needed components for aggregates (0000-00-00)} -@cindex AI-0220 (Ada 2012 feature) -@noindent - This AI addresses a wording problem in the RM that appears to permit some - complex cases of aggregates with non-static discriminants. GNAT has always - implemented the intended semantics. +This AI addresses a wording problem in the RM that appears to permit some +complex cases of aggregates with non-static discriminants. GNAT has always +implemented the intended semantics. -@noindent - RM References: 4.03.01 (17) +RM References: 4.03.01 (17) +@end itemize -@item +@geindex AI-0147 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0147 Conditional expressions (2009-03-29)} -@cindex AI-0147 (Ada 2012 feature) -@noindent - Conditional expressions are permitted. The form of such an expression is: +Conditional expressions are permitted. The form of such an expression is: -@smallexample - (@b{if} @i{expr} @b{then} @i{expr} @{@b{elsif} @i{expr} @b{then} @i{expr}@} [@b{else} @i{expr}]) -@end smallexample +@example +(if expr then expr @{elsif expr then expr@} [else expr]) +@end example - The parentheses can be omitted in contexts where parentheses are present - anyway, such as subprogram arguments and pragma arguments. If the @b{else} - clause is omitted, @b{else True} is assumed; - thus @code{(@b{if} A @b{then} B)} is a way to conveniently represent - @emph{(A implies B)} in standard logic. +The parentheses can be omitted in contexts where parentheses are present +anyway, such as subprogram arguments and pragma arguments. If the @strong{else} +clause is omitted, @strong{else} @emph{True} is assumed; +thus @code{(if A then B)} is a way to conveniently represent +@emph{(A implies B)} in standard logic. -@noindent - RM References: 4.03.03 (15) 4.04 (1) 4.04 (7) 4.05.07 (0) 4.07 (2) - 4.07 (3) 4.09 (12) 4.09 (33) 5.03 (3) 5.03 (4) 7.05 (2.1/2) +RM References: 4.03.03 (15) 4.04 (1) 4.04 (7) 4.05.07 (0) 4.07 (2) +4.07 (3) 4.09 (12) 4.09 (33) 5.03 (3) 5.03 (4) 7.05 (2.1/2) +@end itemize +@geindex AI-0037 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0037 Out-of-range box associations in aggregate (0000-00-00)} -@cindex AI-0037 (Ada 2012 feature) -@noindent - This AI confirms that an association of the form @code{Indx => <>} in an - array aggregate must raise @code{Constraint_Error} if @code{Indx} - is out of range. The RM specified a range check on other associations, but - not when the value of the association was defaulted. GNAT has always inserted - a constraint check on the index value. +This AI confirms that an association of the form @cite{Indx => <>} in an +array aggregate must raise @cite{Constraint_Error} if @cite{Indx} +is out of range. The RM specified a range check on other associations, but +not when the value of the association was defaulted. GNAT has always inserted +a constraint check on the index value. -@noindent - RM References: 4.03.03 (29) +RM References: 4.03.03 (29) +@end itemize +@geindex AI-0123 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0123 Composability of equality (2010-04-13)} -@cindex AI-0123 (Ada 2012 feature) -@noindent - Equality of untagged record composes, so that the predefined equality for a - composite type that includes a component of some untagged record type - @code{R} uses the equality operation of @code{R} (which may be user-defined - or predefined). This makes the behavior of untagged records identical to that - of tagged types in this respect. +Equality of untagged record composes, so that the predefined equality for a +composite type that includes a component of some untagged record type +@cite{R} uses the equality operation of @cite{R} (which may be user-defined +or predefined). This makes the behavior of untagged records identical to that +of tagged types in this respect. + +This change is an incompatibility with previous versions of Ada, but it +corrects a non-uniformity that was often a source of confusion. Analysis of +a large number of industrial programs indicates that in those rare cases +where a composite type had an untagged record component with a user-defined +equality, either there was no use of the composite equality, or else the code +expected the same composability as for tagged types, and thus had a bug that +would be fixed by this change. + +RM References: 4.05.02 (9.7/2) 4.05.02 (14) 4.05.02 (15) 4.05.02 (24) +8.05.04 (8) +@end itemize - This change is an incompatibility with previous versions of Ada, but it - corrects a non-uniformity that was often a source of confusion. Analysis of - a large number of industrial programs indicates that in those rare cases - where a composite type had an untagged record component with a user-defined - equality, either there was no use of the composite equality, or else the code - expected the same composability as for tagged types, and thus had a bug that - would be fixed by this change. +@geindex AI-0088 (Ada 2012 feature) -@noindent - RM References: 4.05.02 (9.7/2) 4.05.02 (14) 4.05.02 (15) 4.05.02 (24) - 8.05.04 (8) +@itemize * -@item +@item @emph{AI-0088 The value of exponentiation (0000-00-00)} -@cindex AI-0088 (Ada 2012 feature) -@noindent - This AI clarifies the equivalence rule given for the dynamic semantics of - exponentiation: the value of the operation can be obtained by repeated - multiplication, but the operation can be implemented otherwise (for example - using the familiar divide-by-two-and-square algorithm, even if this is less - accurate), and does not imply repeated reads of a volatile base. +This AI clarifies the equivalence rule given for the dynamic semantics of +exponentiation: the value of the operation can be obtained by repeated +multiplication, but the operation can be implemented otherwise (for example +using the familiar divide-by-two-and-square algorithm, even if this is less +accurate), and does not imply repeated reads of a volatile base. -@noindent - RM References: 4.05.06 (11) +RM References: 4.05.06 (11) +@end itemize -@item +@geindex AI-0188 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0188 Case expressions (2010-01-09)} -@cindex AI-0188 (Ada 2012 feature) -@noindent - Case expressions are permitted. This allows use of constructs such as: -@smallexample - X := (@b{case} Y @b{is when} 1 => 2, @b{when} 2 => 3, @b{when others} => 31) -@end smallexample +Case expressions are permitted. This allows use of constructs such as: -@noindent - RM References: 4.05.07 (0) 4.05.08 (0) 4.09 (12) 4.09 (33) +@example +X := (case Y is when 1 => 2, when 2 => 3, when others => 31) +@end example -@item +RM References: 4.05.07 (0) 4.05.08 (0) 4.09 (12) 4.09 (33) +@end itemize + +@geindex AI-0104 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0104 Null exclusion and uninitialized allocator (2010-07-15)} -@cindex AI-0104 (Ada 2012 feature) -@noindent - The assignment @code{Ptr := @b{new not null} Some_Ptr;} will raise - @code{Constraint_Error} because the default value of the allocated object is - @b{null}. This useless construct is illegal in Ada 2012. +The assignment @code{Ptr := new not null Some_Ptr;} will raise +@code{Constraint_Error} because the default value of the allocated object is +@strong{null}. This useless construct is illegal in Ada 2012. -@noindent - RM References: 4.08 (2) +RM References: 4.08 (2) +@end itemize -@item +@geindex AI-0157 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0157 Allocation/Deallocation from empty pool (2010-07-11)} -@cindex AI-0157 (Ada 2012 feature) -@noindent - Allocation and Deallocation from an empty storage pool (i.e. allocation or - deallocation of a pointer for which a static storage size clause of zero - has been given) is now illegal and is detected as such. GNAT - previously gave a warning but not an error. +Allocation and Deallocation from an empty storage pool (i.e. allocation or +deallocation of a pointer for which a static storage size clause of zero +has been given) is now illegal and is detected as such. GNAT +previously gave a warning but not an error. -@noindent - RM References: 4.08 (5.3/2) 13.11.02 (4) 13.11.02 (17) +RM References: 4.08 (5.3/2) 13.11.02 (4) 13.11.02 (17) +@end itemize -@item +@geindex AI-0179 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0179 Statement not required after label (2010-04-10)} -@cindex AI-0179 (Ada 2012 feature) -@noindent - It is not necessary to have a statement following a label, so a label - can appear at the end of a statement sequence without the need for putting a - null statement afterwards, but it is not allowable to have only labels and - no real statements in a statement sequence. +It is not necessary to have a statement following a label, so a label +can appear at the end of a statement sequence without the need for putting a +null statement afterwards, but it is not allowable to have only labels and +no real statements in a statement sequence. -@noindent - RM References: 5.01 (2) +RM References: 5.01 (2) +@end itemize +@geindex AI-0139-2 (Ada 2012 feature) -@item -@emph{AI-139-2 Syntactic sugar for iterators (2010-09-29)} -@cindex AI-139-2 (Ada 2012 feature) -@noindent - The new syntax for iterating over arrays and containers is now implemented. - Iteration over containers is for now limited to read-only iterators. Only - default iterators are supported, with the syntax: @code{@b{for} Elem @b{of} C}. +@itemize * -@noindent - RM References: 5.05 +@item +@emph{AI-0139-2 Syntactic sugar for iterators (2010-09-29)} -@item +The new syntax for iterating over arrays and containers is now implemented. +Iteration over containers is for now limited to read-only iterators. Only +default iterators are supported, with the syntax: @cite{for Elem of C}. + +RM References: 5.05 +@end itemize + +@geindex AI-0134 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0134 Profiles must match for full conformance (0000-00-00)} -@cindex AI-0134 (Ada 2012 feature) -@noindent - For full conformance, the profiles of anonymous-access-to-subprogram - parameters must match. GNAT has always enforced this rule. +For full conformance, the profiles of anonymous-access-to-subprogram +parameters must match. GNAT has always enforced this rule. -@noindent - RM References: 6.03.01 (18) +RM References: 6.03.01 (18) +@end itemize -@item +@geindex AI-0207 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0207 Mode conformance and access constant (0000-00-00)} -@cindex AI-0207 (Ada 2012 feature) -@noindent - This AI confirms that access_to_constant indication must match for mode - conformance. This was implemented in GNAT when the qualifier was originally - introduced in Ada 2005. +This AI confirms that access_to_constant indication must match for mode +conformance. This was implemented in GNAT when the qualifier was originally +introduced in Ada 2005. + +RM References: 6.03.01 (16/2) +@end itemize -@noindent - RM References: 6.03.01 (16/2) +@geindex AI-0046 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0046 Null exclusion match for full conformance (2010-07-17)} -@cindex AI-0046 (Ada 2012 feature) -@noindent - For full conformance, in the case of access parameters, the null exclusion - must match (either both or neither must have @code{@b{not null}}). +For full conformance, in the case of access parameters, the null exclusion +must match (either both or neither must have @code{not null}). -@noindent - RM References: 6.03.02 (18) +RM References: 6.03.02 (18) +@end itemize +@geindex AI-0118 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0118 The association of parameter associations (0000-00-00)} -@cindex AI-0118 (Ada 2012 feature) -@noindent - This AI clarifies the rules for named associations in subprogram calls and - generic instantiations. The rules have been in place since Ada 83. +This AI clarifies the rules for named associations in subprogram calls and +generic instantiations. The rules have been in place since Ada 83. -@noindent - RM References: 6.04.01 (2) 12.03 (9) +RM References: 6.04.01 (2) 12.03 (9) +@end itemize +@geindex AI-0196 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0196 Null exclusion tests for out parameters (0000-00-00)} -@cindex AI-0196 (Ada 2012 feature) -@noindent - Null exclusion checks are not made for @code{@b{out}} parameters when - evaluating the actual parameters. GNAT has never generated these checks. +Null exclusion checks are not made for @cite{**out**} parameters when +evaluating the actual parameters. GNAT has never generated these checks. + +RM References: 6.04.01 (13) +@end itemize -@noindent - RM References: 6.04.01 (13) +@geindex AI-0015 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0015 Constant return objects (0000-00-00)} -@cindex AI-0015 (Ada 2012 feature) -@noindent - The return object declared in an @i{extended_return_statement} may be - declared constant. This was always intended, and GNAT has always allowed it. +The return object declared in an @emph{extended_return_statement} may be +declared constant. This was always intended, and GNAT has always allowed it. -@noindent - RM References: 6.05 (2.1/2) 3.03 (10/2) 3.03 (21) 6.05 (5/2) - 6.05 (5.7/2) +RM References: 6.05 (2.1/2) 3.03 (10/2) 3.03 (21) 6.05 (5/2) +6.05 (5.7/2) +@end itemize +@geindex AI-0032 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0032 Extended return for class-wide functions (0000-00-00)} -@cindex AI-0032 (Ada 2012 feature) -@noindent - If a function returns a class-wide type, the object of an extended return - statement can be declared with a specific type that is covered by the class- - wide type. This has been implemented in GNAT since the introduction of - extended returns. Note AI-0103 complements this AI by imposing matching - rules for constrained return types. +If a function returns a class-wide type, the object of an extended return +statement can be declared with a specific type that is covered by the class- +wide type. This has been implemented in GNAT since the introduction of +extended returns. Note AI-0103 complements this AI by imposing matching +rules for constrained return types. -@noindent - RM References: 6.05 (5.2/2) 6.05 (5.3/2) 6.05 (5.6/2) 6.05 (5.8/2) - 6.05 (8/2) +RM References: 6.05 (5.2/2) 6.05 (5.3/2) 6.05 (5.6/2) 6.05 (5.8/2) +6.05 (8/2) +@end itemize -@item +@geindex AI-0103 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0103 Static matching for extended return (2010-07-23)} -@cindex AI-0103 (Ada 2012 feature) -@noindent - If the return subtype of a function is an elementary type or a constrained - type, the subtype indication in an extended return statement must match - statically this return subtype. +If the return subtype of a function is an elementary type or a constrained +type, the subtype indication in an extended return statement must match +statically this return subtype. + +RM References: 6.05 (5.2/2) +@end itemize -@noindent - RM References: 6.05 (5.2/2) +@geindex AI-0058 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0058 Abnormal completion of an extended return (0000-00-00)} -@cindex AI-0058 (Ada 2012 feature) -@noindent - The RM had some incorrect wording implying wrong treatment of abnormal - completion in an extended return. GNAT has always implemented the intended - correct semantics as described by this AI. +The RM had some incorrect wording implying wrong treatment of abnormal +completion in an extended return. GNAT has always implemented the intended +correct semantics as described by this AI. -@noindent - RM References: 6.05 (22/2) +RM References: 6.05 (22/2) +@end itemize +@geindex AI-0050 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0050 Raising Constraint_Error early for function call (0000-00-00)} -@cindex AI-0050 (Ada 2012 feature) -@noindent - The implementation permissions for raising @code{Constraint_Error} early on a function call when it was clear an exception would be raised were over-permissive and allowed mishandling of discriminants in some cases. GNAT did - not take advantage of these incorrect permissions in any case. +The implementation permissions for raising @cite{Constraint_Error} early on a function call +when it was clear an exception would be raised were over-permissive and allowed +mishandling of discriminants in some cases. GNAT did +not take advantage of these incorrect permissions in any case. -@noindent - RM References: 6.05 (24/2) +RM References: 6.05 (24/2) +@end itemize +@geindex AI-0125 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0125 Nonoverridable operations of an ancestor (2010-09-28)} -@cindex AI-0125 (Ada 2012 feature) -@noindent - In Ada 2012, the declaration of a primitive operation of a type extension - or private extension can also override an inherited primitive that is not - visible at the point of this declaration. +In Ada 2012, the declaration of a primitive operation of a type extension +or private extension can also override an inherited primitive that is not +visible at the point of this declaration. -@noindent - RM References: 7.03.01 (6) 8.03 (23) 8.03.01 (5/2) 8.03.01 (6/2) +RM References: 7.03.01 (6) 8.03 (23) 8.03.01 (5/2) 8.03.01 (6/2) +@end itemize -@item +@geindex AI-0062 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0062 Null exclusions and deferred constants (0000-00-00)} -@cindex AI-0062 (Ada 2012 feature) -@noindent - A full constant may have a null exclusion even if its associated deferred - constant does not. GNAT has always allowed this. +A full constant may have a null exclusion even if its associated deferred +constant does not. GNAT has always allowed this. + +RM References: 7.04 (6/2) 7.04 (7.1/2) +@end itemize -@noindent - RM References: 7.04 (6/2) 7.04 (7.1/2) +@geindex AI-0178 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0178 Incomplete views are limited (0000-00-00)} -@cindex AI-0178 (Ada 2012 feature) -@noindent - This AI clarifies the role of incomplete views and plugs an omission in the - RM. GNAT always correctly restricted the use of incomplete views and types. +This AI clarifies the role of incomplete views and plugs an omission in the +RM. GNAT always correctly restricted the use of incomplete views and types. -@noindent - RM References: 7.05 (3/2) 7.05 (6/2) +RM References: 7.05 (3/2) 7.05 (6/2) +@end itemize -@item +@geindex AI-0087 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0087 Actual for formal nonlimited derived type (2010-07-15)} -@cindex AI-0087 (Ada 2012 feature) -@noindent - The actual for a formal nonlimited derived type cannot be limited. In - particular, a formal derived type that extends a limited interface but which - is not explicitly limited cannot be instantiated with a limited type. +The actual for a formal nonlimited derived type cannot be limited. In +particular, a formal derived type that extends a limited interface but which +is not explicitly limited cannot be instantiated with a limited type. + +RM References: 7.05 (5/2) 12.05.01 (5.1/2) +@end itemize -@noindent - RM References: 7.05 (5/2) 12.05.01 (5.1/2) +@geindex AI-0099 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0099 Tag determines whether finalization needed (0000-00-00)} -@cindex AI-0099 (Ada 2012 feature) -@noindent - This AI clarifies that ``needs finalization'' is part of dynamic semantics, - and therefore depends on the run-time characteristics of an object (i.e. its - tag) and not on its nominal type. As the AI indicates: ``we do not expect - this to affect any implementation''. +This AI clarifies that 'needs finalization' is part of dynamic semantics, +and therefore depends on the run-time characteristics of an object (i.e. its +tag) and not on its nominal type. As the AI indicates: "we do not expect +this to affect any implementation'@w{'}. -@noindent - RM References: 7.06.01 (6) 7.06.01 (7) 7.06.01 (8) 7.06.01 (9/2) +RM References: 7.06.01 (6) 7.06.01 (7) 7.06.01 (8) 7.06.01 (9/2) +@end itemize +@geindex AI-0064 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0064 Redundant finalization rule (0000-00-00)} -@cindex AI-0064 (Ada 2012 feature) -@noindent - This is an editorial change only. The intended behavior is already checked - by an existing ACATS test, which GNAT has always executed correctly. +This is an editorial change only. The intended behavior is already checked +by an existing ACATS test, which GNAT has always executed correctly. -@noindent - RM References: 7.06.01 (17.1/1) +RM References: 7.06.01 (17.1/1) +@end itemize -@item +@geindex AI-0026 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0026 Missing rules for Unchecked_Union (2010-07-07)} -@cindex AI-0026 (Ada 2012 feature) -@noindent - Record representation clauses concerning Unchecked_Union types cannot mention - the discriminant of the type. The type of a component declared in the variant - part of an Unchecked_Union cannot be controlled, have controlled components, - nor have protected or task parts. If an Unchecked_Union type is declared - within the body of a generic unit or its descendants, then the type of a - component declared in the variant part cannot be a formal private type or a - formal private extension declared within the same generic unit. +Record representation clauses concerning Unchecked_Union types cannot mention +the discriminant of the type. The type of a component declared in the variant +part of an Unchecked_Union cannot be controlled, have controlled components, +nor have protected or task parts. If an Unchecked_Union type is declared +within the body of a generic unit or its descendants, then the type of a +component declared in the variant part cannot be a formal private type or a +formal private extension declared within the same generic unit. -@noindent - RM References: 7.06 (9.4/2) B.03.03 (9/2) B.03.03 (10/2) +RM References: 7.06 (9.4/2) B.03.03 (9/2) B.03.03 (10/2) +@end itemize +@geindex AI-0205 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0205 Extended return declares visible name (0000-00-00)} -@cindex AI-0205 (Ada 2012 feature) -@noindent - This AI corrects a simple omission in the RM. Return objects have always - been visible within an extended return statement. +This AI corrects a simple omission in the RM. Return objects have always +been visible within an extended return statement. + +RM References: 8.03 (17) +@end itemize -@noindent - RM References: 8.03 (17) +@geindex AI-0042 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0042 Overriding versus implemented-by (0000-00-00)} -@cindex AI-0042 (Ada 2012 feature) -@noindent - This AI fixes a wording gap in the RM. An operation of a synchronized - interface can be implemented by a protected or task entry, but the abstract - operation is not being overridden in the usual sense, and it must be stated - separately that this implementation is legal. This has always been the case - in GNAT. +This AI fixes a wording gap in the RM. An operation of a synchronized +interface can be implemented by a protected or task entry, but the abstract +operation is not being overridden in the usual sense, and it must be stated +separately that this implementation is legal. This has always been the case +in GNAT. -@noindent - RM References: 9.01 (9.2/2) 9.04 (11.1/2) +RM References: 9.01 (9.2/2) 9.04 (11.1/2) +@end itemize -@item +@geindex AI-0030 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0030 Requeue on synchronized interfaces (2010-07-19)} -@cindex AI-0030 (Ada 2012 feature) -@noindent - Requeue is permitted to a protected, synchronized or task interface primitive - providing it is known that the overriding operation is an entry. Otherwise - the requeue statement has the same effect as a procedure call. Use of pragma - @code{Implemented} provides a way to impose a static requirement on the - overriding operation by adhering to one of the implementation kinds: entry, - protected procedure or any of the above. +Requeue is permitted to a protected, synchronized or task interface primitive +providing it is known that the overriding operation is an entry. Otherwise +the requeue statement has the same effect as a procedure call. Use of pragma +@cite{Implemented} provides a way to impose a static requirement on the +overriding operation by adhering to one of the implementation kinds: entry, +protected procedure or any of the above. -@noindent - RM References: 9.05 (9) 9.05.04 (2) 9.05.04 (3) 9.05.04 (5) - 9.05.04 (6) 9.05.04 (7) 9.05.04 (12) +RM References: 9.05 (9) 9.05.04 (2) 9.05.04 (3) 9.05.04 (5) +9.05.04 (6) 9.05.04 (7) 9.05.04 (12) +@end itemize +@geindex AI-0201 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0201 Independence of atomic object components (2010-07-22)} -@cindex AI-0201 (Ada 2012 feature) -@noindent - If an Atomic object has a pragma @code{Pack} or a @code{Component_Size} - attribute, then individual components may not be addressable by independent - tasks. However, if the representation clause has no effect (is confirming), - then independence is not compromised. Furthermore, in GNAT, specification of - other appropriately addressable component sizes (e.g. 16 for 8-bit - characters) also preserves independence. GNAT now gives very clear warnings - both for the declaration of such a type, and for any assignment to its components. +If an Atomic object has a pragma @cite{Pack} or a @cite{Component_Size} +attribute, then individual components may not be addressable by independent +tasks. However, if the representation clause has no effect (is confirming), +then independence is not compromised. Furthermore, in GNAT, specification of +other appropriately addressable component sizes (e.g. 16 for 8-bit +characters) also preserves independence. GNAT now gives very clear warnings +both for the declaration of such a type, and for any assignment to its components. -@noindent - RM References: 9.10 (1/3) C.06 (22/2) C.06 (23/2) +RM References: 9.10 (1/3) C.06 (22/2) C.06 (23/2) +@end itemize -@item +@geindex AI-0009 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0009 Pragma Independent[_Components] (2010-07-23)} -@cindex AI-0009 (Ada 2012 feature) -@noindent - This AI introduces the new pragmas @code{Independent} and - @code{Independent_Components}, - which control guaranteeing independence of access to objects and components. - The AI also requires independence not unaffected by confirming rep clauses. +This AI introduces the new pragmas @cite{Independent} and +@cite{Independent_Components}, +which control guaranteeing independence of access to objects and components. +The AI also requires independence not unaffected by confirming rep clauses. -@noindent - RM References: 9.10 (1) 13.01 (15/1) 13.02 (9) 13.03 (13) C.06 (2) - C.06 (4) C.06 (6) C.06 (9) C.06 (13) C.06 (14) +RM References: 9.10 (1) 13.01 (15/1) 13.02 (9) 13.03 (13) C.06 (2) +C.06 (4) C.06 (6) C.06 (9) C.06 (13) C.06 (14) +@end itemize +@geindex AI-0072 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0072 Task signalling using 'Terminated (0000-00-00)} -@cindex AI-0072 (Ada 2012 feature) -@noindent - This AI clarifies that task signalling for reading @code{'Terminated} only - occurs if the result is True. GNAT semantics has always been consistent with - this notion of task signalling. +This AI clarifies that task signalling for reading @cite{'Terminated} only +occurs if the result is True. GNAT semantics has always been consistent with +this notion of task signalling. -@noindent - RM References: 9.10 (6.1/1) +RM References: 9.10 (6.1/1) +@end itemize -@item +@geindex AI-0108 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0108 Limited incomplete view and discriminants (0000-00-00)} -@cindex AI-0108 (Ada 2012 feature) -@noindent - This AI confirms that an incomplete type from a limited view does not have - discriminants. This has always been the case in GNAT. +This AI confirms that an incomplete type from a limited view does not have +discriminants. This has always been the case in GNAT. -@noindent - RM References: 10.01.01 (12.3/2) +RM References: 10.01.01 (12.3/2) +@end itemize -@item +@geindex AI-0129 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0129 Limited views and incomplete types (0000-00-00)} -@cindex AI-0129 (Ada 2012 feature) -@noindent - This AI clarifies the description of limited views: a limited view of a - package includes only one view of a type that has an incomplete declaration - and a full declaration (there is no possible ambiguity in a client package). - This AI also fixes an omission: a nested package in the private part has no - limited view. GNAT always implemented this correctly. +This AI clarifies the description of limited views: a limited view of a +package includes only one view of a type that has an incomplete declaration +and a full declaration (there is no possible ambiguity in a client package). +This AI also fixes an omission: a nested package in the private part has no +limited view. GNAT always implemented this correctly. -@noindent - RM References: 10.01.01 (12.2/2) 10.01.01 (12.3/2) +RM References: 10.01.01 (12.2/2) 10.01.01 (12.3/2) +@end itemize +@geindex AI-0077 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0077 Limited withs and scope of declarations (0000-00-00)} -@cindex AI-0077 (Ada 2012 feature) -@noindent - This AI clarifies that a declaration does not include a context clause, - and confirms that it is illegal to have a context in which both a limited - and a nonlimited view of a package are accessible. Such double visibility - was always rejected by GNAT. +This AI clarifies that a declaration does not include a context clause, +and confirms that it is illegal to have a context in which both a limited +and a nonlimited view of a package are accessible. Such double visibility +was always rejected by GNAT. -@noindent - RM References: 10.01.02 (12/2) 10.01.02 (21/2) 10.01.02 (22/2) +RM References: 10.01.02 (12/2) 10.01.02 (21/2) 10.01.02 (22/2) +@end itemize -@item +@geindex AI-0122 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0122 Private with and children of generics (0000-00-00)} -@cindex AI-0122 (Ada 2012 feature) -@noindent - This AI clarifies the visibility of private children of generic units within - instantiations of a parent. GNAT has always handled this correctly. +This AI clarifies the visibility of private children of generic units within +instantiations of a parent. GNAT has always handled this correctly. -@noindent - RM References: 10.01.02 (12/2) +RM References: 10.01.02 (12/2) +@end itemize +@geindex AI-0040 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0040 Limited with clauses on descendant (0000-00-00)} -@cindex AI-0040 (Ada 2012 feature) -@noindent - This AI confirms that a limited with clause in a child unit cannot name - an ancestor of the unit. This has always been checked in GNAT. +This AI confirms that a limited with clause in a child unit cannot name +an ancestor of the unit. This has always been checked in GNAT. -@noindent - RM References: 10.01.02 (20/2) +RM References: 10.01.02 (20/2) +@end itemize -@item +@geindex AI-0132 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0132 Placement of library unit pragmas (0000-00-00)} -@cindex AI-0132 (Ada 2012 feature) -@noindent - This AI fills a gap in the description of library unit pragmas. The pragma - clearly must apply to a library unit, even if it does not carry the name - of the enclosing unit. GNAT has always enforced the required check. +This AI fills a gap in the description of library unit pragmas. The pragma +clearly must apply to a library unit, even if it does not carry the name +of the enclosing unit. GNAT has always enforced the required check. + +RM References: 10.01.05 (7) +@end itemize -@noindent - RM References: 10.01.05 (7) +@geindex AI-0034 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0034 Categorization of limited views (0000-00-00)} -@cindex AI-0034 (Ada 2012 feature) -@noindent - The RM makes certain limited with clauses illegal because of categorization - considerations, when the corresponding normal with would be legal. This is - not intended, and GNAT has always implemented the recommended behavior. +The RM makes certain limited with clauses illegal because of categorization +considerations, when the corresponding normal with would be legal. This is +not intended, and GNAT has always implemented the recommended behavior. -@noindent - RM References: 10.02.01 (11/1) 10.02.01 (17/2) +RM References: 10.02.01 (11/1) 10.02.01 (17/2) +@end itemize +@geindex AI-0035 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0035 Inconsistencies with Pure units (0000-00-00)} -@cindex AI-0035 (Ada 2012 feature) -@noindent - This AI remedies some inconsistencies in the legality rules for Pure units. - Derived access types are legal in a pure unit (on the assumption that the - rule for a zero storage pool size has been enforced on the ancestor type). - The rules are enforced in generic instances and in subunits. GNAT has always - implemented the recommended behavior. +This AI remedies some inconsistencies in the legality rules for Pure units. +Derived access types are legal in a pure unit (on the assumption that the +rule for a zero storage pool size has been enforced on the ancestor type). +The rules are enforced in generic instances and in subunits. GNAT has always +implemented the recommended behavior. -@noindent - RM References: 10.02.01 (15.1/2) 10.02.01 (15.4/2) 10.02.01 (15.5/2) 10.02.01 (17/2) +RM References: 10.02.01 (15.1/2) 10.02.01 (15.4/2) 10.02.01 (15.5/2) 10.02.01 (17/2) +@end itemize +@geindex AI-0219 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0219 Pure permissions and limited parameters (2010-05-25)} -@cindex AI-0219 (Ada 2012 feature) -@noindent - This AI refines the rules for the cases with limited parameters which do not - allow the implementations to omit ``redundant''. GNAT now properly conforms - to the requirements of this binding interpretation. +This AI refines the rules for the cases with limited parameters which do not +allow the implementations to omit 'redundant'. GNAT now properly conforms +to the requirements of this binding interpretation. -@noindent - RM References: 10.02.01 (18/2) +RM References: 10.02.01 (18/2) +@end itemize -@item +@geindex AI-0043 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0043 Rules about raising exceptions (0000-00-00)} -@cindex AI-0043 (Ada 2012 feature) -@noindent - This AI covers various omissions in the RM regarding the raising of - exceptions. GNAT has always implemented the intended semantics. +This AI covers various omissions in the RM regarding the raising of +exceptions. GNAT has always implemented the intended semantics. + +RM References: 11.04.01 (10.1/2) 11 (2) +@end itemize -@noindent - RM References: 11.04.01 (10.1/2) 11 (2) +@geindex AI-0200 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0200 Mismatches in formal package declarations (0000-00-00)} -@cindex AI-0200 (Ada 2012 feature) -@noindent - This AI plugs a gap in the RM which appeared to allow some obviously intended - illegal instantiations. GNAT has never allowed these instantiations. +This AI plugs a gap in the RM which appeared to allow some obviously intended +illegal instantiations. GNAT has never allowed these instantiations. -@noindent - RM References: 12.07 (16) +RM References: 12.07 (16) +@end itemize +@geindex AI-0112 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0112 Detection of duplicate pragmas (2010-07-24)} -@cindex AI-0112 (Ada 2012 feature) -@noindent - This AI concerns giving names to various representation aspects, but the - practical effect is simply to make the use of duplicate - @code{Atomic}[@code{_Components}], - @code{Volatile}[@code{_Components}] and - @code{Independent}[@code{_Components}] pragmas illegal, and GNAT - now performs this required check. +This AI concerns giving names to various representation aspects, but the +practical effect is simply to make the use of duplicate +@cite{Atomic[_Components]}, +@cite{Volatile[_Components]}, and +@cite{Independent[_Components]} pragmas illegal, and GNAT +now performs this required check. -@noindent - RM References: 13.01 (8) +RM References: 13.01 (8) +@end itemize -@item +@geindex AI-0106 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0106 No representation pragmas on generic formals (0000-00-00)} -@cindex AI-0106 (Ada 2012 feature) -@noindent - The RM appeared to allow representation pragmas on generic formal parameters, - but this was not intended, and GNAT has never permitted this usage. +The RM appeared to allow representation pragmas on generic formal parameters, +but this was not intended, and GNAT has never permitted this usage. -@noindent - RM References: 13.01 (9.1/1) +RM References: 13.01 (9.1/1) +@end itemize +@geindex AI-0012 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0012 Pack/Component_Size for aliased/atomic (2010-07-15)} -@cindex AI-0012 (Ada 2012 feature) -@noindent - It is now illegal to give an inappropriate component size or a pragma - @code{Pack} that attempts to change the component size in the case of atomic - or aliased components. Previously GNAT ignored such an attempt with a - warning. +It is now illegal to give an inappropriate component size or a pragma +@cite{Pack} that attempts to change the component size in the case of atomic +or aliased components. Previously GNAT ignored such an attempt with a +warning. -@noindent - RM References: 13.02 (6.1/2) 13.02 (7) C.06 (10) C.06 (11) C.06 (21) +RM References: 13.02 (6.1/2) 13.02 (7) C.06 (10) C.06 (11) C.06 (21) +@end itemize +@geindex AI-0039 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0039 Stream attributes cannot be dynamic (0000-00-00)} -@cindex AI-0039 (Ada 2012 feature) -@noindent - The RM permitted the use of dynamic expressions (such as @code{ptr.@b{all})} - for stream attributes, but these were never useful and are now illegal. GNAT - has always regarded such expressions as illegal. +The RM permitted the use of dynamic expressions (such as @code{ptr.all})` +for stream attributes, but these were never useful and are now illegal. GNAT +has always regarded such expressions as illegal. -@noindent - RM References: 13.03 (4) 13.03 (6) 13.13.02 (38/2) +RM References: 13.03 (4) 13.03 (6) 13.13.02 (38/2) +@end itemize +@geindex AI-0095 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0095 Address of intrinsic subprograms (0000-00-00)} -@cindex AI-0095 (Ada 2012 feature) -@noindent - The prefix of @code{'Address} cannot statically denote a subprogram with - convention @code{Intrinsic}. The use of the @code{Address} attribute raises - @code{Program_Error} if the prefix denotes a subprogram with convention - @code{Intrinsic}. +The prefix of @cite{'Address} cannot statically denote a subprogram with +convention @cite{Intrinsic}. The use of the @cite{Address} attribute raises +@cite{Program_Error} if the prefix denotes a subprogram with convention +@cite{Intrinsic}. -@noindent - RM References: 13.03 (11/1) +RM References: 13.03 (11/1) +@end itemize +@geindex AI-0116 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0116 Alignment of class-wide objects (0000-00-00)} -@cindex AI-0116 (Ada 2012 feature) -@noindent - This AI requires that the alignment of a class-wide object be no greater - than the alignment of any type in the class. GNAT has always followed this - recommendation. +This AI requires that the alignment of a class-wide object be no greater +than the alignment of any type in the class. GNAT has always followed this +recommendation. + +RM References: 13.03 (29) 13.11 (16) +@end itemize -@noindent - RM References: 13.03 (29) 13.11 (16) +@geindex AI-0146 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0146 Type invariants (2009-09-21)} -@cindex AI-0146 (Ada 2012 feature) - -@noindent - Type invariants may be specified for private types using the aspect notation. - Aspect @code{Type_Invariant} may be specified for any private type, - @code{Type_Invariant'Class} can - only be specified for tagged types, and is inherited by any descendent of the - tagged types. The invariant is a boolean expression that is tested for being - true in the following situations: conversions to the private type, object - declarations for the private type that are default initialized, and - [@b{in}] @b{out} - parameters and returned result on return from any primitive operation for - the type that is visible to a client. - GNAT defines the synonyms @code{Invariant} for @code{Type_Invariant} and - @code{Invariant'Class} for @code{Type_Invariant'Class}. - -@noindent - RM References: 13.03.03 (00) -@item +Type invariants may be specified for private types using the aspect notation. +Aspect @cite{Type_Invariant} may be specified for any private type, +@cite{Type_Invariant'Class} can +only be specified for tagged types, and is inherited by any descendent of the +tagged types. The invariant is a boolean expression that is tested for being +true in the following situations: conversions to the private type, object +declarations for the private type that are default initialized, and +[@strong{in}] @strong{out} +parameters and returned result on return from any primitive operation for +the type that is visible to a client. +GNAT defines the synonyms @cite{Invariant} for @cite{Type_Invariant} and +@cite{Invariant'Class} for @cite{Type_Invariant'Class}. + +RM References: 13.03.03 (00) +@end itemize + +@geindex AI-0078 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0078 Relax Unchecked_Conversion alignment rules (0000-00-00)} -@cindex AI-0078 (Ada 2012 feature) -@noindent - In Ada 2012, compilers are required to support unchecked conversion where the - target alignment is a multiple of the source alignment. GNAT always supported - this case (and indeed all cases of differing alignments, doing copies where - required if the alignment was reduced). +In Ada 2012, compilers are required to support unchecked conversion where the +target alignment is a multiple of the source alignment. GNAT always supported +this case (and indeed all cases of differing alignments, doing copies where +required if the alignment was reduced). -@noindent - RM References: 13.09 (7) +RM References: 13.09 (7) +@end itemize +@geindex AI-0195 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0195 Invalid value handling is implementation defined (2010-07-03)} -@cindex AI-0195 (Ada 2012 feature) -@noindent - The handling of invalid values is now designated to be implementation - defined. This is a documentation change only, requiring Annex M in the GNAT - Reference Manual to document this handling. - In GNAT, checks for invalid values are made - only when necessary to avoid erroneous behavior. Operations like assignments - which cannot cause erroneous behavior ignore the possibility of invalid - values and do not do a check. The date given above applies only to the - documentation change, this behavior has always been implemented by GNAT. +The handling of invalid values is now designated to be implementation +defined. This is a documentation change only, requiring Annex M in the GNAT +Reference Manual to document this handling. +In GNAT, checks for invalid values are made +only when necessary to avoid erroneous behavior. Operations like assignments +which cannot cause erroneous behavior ignore the possibility of invalid +values and do not do a check. The date given above applies only to the +documentation change, this behavior has always been implemented by GNAT. -@noindent - RM References: 13.09.01 (10) +RM References: 13.09.01 (10) +@end itemize -@item +@geindex AI-0193 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0193 Alignment of allocators (2010-09-16)} -@cindex AI-0193 (Ada 2012 feature) -@noindent - This AI introduces a new attribute @code{Max_Alignment_For_Allocation}, - analogous to @code{Max_Size_In_Storage_Elements}, but for alignment instead - of size. +This AI introduces a new attribute @cite{Max_Alignment_For_Allocation}, +analogous to @cite{Max_Size_In_Storage_Elements}, but for alignment instead +of size. -@noindent - RM References: 13.11 (16) 13.11 (21) 13.11.01 (0) 13.11.01 (1) - 13.11.01 (2) 13.11.01 (3) +RM References: 13.11 (16) 13.11 (21) 13.11.01 (0) 13.11.01 (1) +13.11.01 (2) 13.11.01 (3) +@end itemize +@geindex AI-0177 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0177 Parameterized expressions (2010-07-10)} -@cindex AI-0177 (Ada 2012 feature) -@noindent - The new Ada 2012 notion of parameterized expressions is implemented. The form - is: -@smallexample - @i{function specification} @b{is} (@i{expression}) -@end smallexample +The new Ada 2012 notion of parameterized expressions is implemented. The form +is: + +@example +function-specification is (expression) +@end example -@noindent - This is exactly equivalent to the - corresponding function body that returns the expression, but it can appear - in a package spec. Note that the expression must be parenthesized. +This is exactly equivalent to the +corresponding function body that returns the expression, but it can appear +in a package spec. Note that the expression must be parenthesized. -@noindent - RM References: 13.11.01 (3/2) +RM References: 13.11.01 (3/2) +@end itemize -@item +@geindex AI-0033 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0033 Attach/Interrupt_Handler in generic (2010-07-24)} -@cindex AI-0033 (Ada 2012 feature) -@noindent - Neither of these two pragmas may appear within a generic template, because - the generic might be instantiated at other than the library level. +Neither of these two pragmas may appear within a generic template, because +the generic might be instantiated at other than the library level. -@noindent - RM References: 13.11.02 (16) C.03.01 (7/2) C.03.01 (8/2) +RM References: 13.11.02 (16) C.03.01 (7/2) C.03.01 (8/2) +@end itemize +@geindex AI-0161 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0161 Restriction No_Default_Stream_Attributes (2010-09-11)} -@cindex AI-0161 (Ada 2012 feature) -@noindent - A new restriction @code{No_Default_Stream_Attributes} prevents the use of any - of the default stream attributes for elementary types. If this restriction is - in force, then it is necessary to provide explicit subprograms for any - stream attributes used. +A new restriction @cite{No_Default_Stream_Attributes} prevents the use of any +of the default stream attributes for elementary types. If this restriction is +in force, then it is necessary to provide explicit subprograms for any +stream attributes used. -@noindent - RM References: 13.12.01 (4/2) 13.13.02 (40/2) 13.13.02 (52/2) +RM References: 13.12.01 (4/2) 13.13.02 (40/2) 13.13.02 (52/2) +@end itemize -@item +@geindex AI-0194 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0194 Value of Stream_Size attribute (0000-00-00)} -@cindex AI-0194 (Ada 2012 feature) -@noindent - The @code{Stream_Size} attribute returns the default number of bits in the - stream representation of the given type. - This value is not affected by the presence - of stream subprogram attributes for the type. GNAT has always implemented - this interpretation. +The @cite{Stream_Size} attribute returns the default number of bits in the +stream representation of the given type. +This value is not affected by the presence +of stream subprogram attributes for the type. GNAT has always implemented +this interpretation. -@noindent - RM References: 13.13.02 (1.2/2) +RM References: 13.13.02 (1.2/2) +@end itemize -@item +@geindex AI-0109 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0109 Redundant check in S'Class'Input (0000-00-00)} -@cindex AI-0109 (Ada 2012 feature) -@noindent - This AI is an editorial change only. It removes the need for a tag check - that can never fail. +This AI is an editorial change only. It removes the need for a tag check +that can never fail. -@noindent - RM References: 13.13.02 (34/2) +RM References: 13.13.02 (34/2) +@end itemize -@item +@geindex AI-0007 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0007 Stream read and private scalar types (0000-00-00)} -@cindex AI-0007 (Ada 2012 feature) -@noindent - The RM as written appeared to limit the possibilities of declaring read - attribute procedures for private scalar types. This limitation was not - intended, and has never been enforced by GNAT. +The RM as written appeared to limit the possibilities of declaring read +attribute procedures for private scalar types. This limitation was not +intended, and has never been enforced by GNAT. + +RM References: 13.13.02 (50/2) 13.13.02 (51/2) +@end itemize -@noindent - RM References: 13.13.02 (50/2) 13.13.02 (51/2) +@geindex AI-0065 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0065 Remote access types and external streaming (0000-00-00)} -@cindex AI-0065 (Ada 2012 feature) -@noindent - This AI clarifies the fact that all remote access types support external - streaming. This fixes an obvious oversight in the definition of the - language, and GNAT always implemented the intended correct rules. +This AI clarifies the fact that all remote access types support external +streaming. This fixes an obvious oversight in the definition of the +language, and GNAT always implemented the intended correct rules. -@noindent - RM References: 13.13.02 (52/2) +RM References: 13.13.02 (52/2) +@end itemize -@item +@geindex AI-0019 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0019 Freezing of primitives for tagged types (0000-00-00)} -@cindex AI-0019 (Ada 2012 feature) -@noindent - The RM suggests that primitive subprograms of a specific tagged type are - frozen when the tagged type is frozen. This would be an incompatible change - and is not intended. GNAT has never attempted this kind of freezing and its - behavior is consistent with the recommendation of this AI. +The RM suggests that primitive subprograms of a specific tagged type are +frozen when the tagged type is frozen. This would be an incompatible change +and is not intended. GNAT has never attempted this kind of freezing and its +behavior is consistent with the recommendation of this AI. -@noindent - RM References: 13.14 (2) 13.14 (3/1) 13.14 (8.1/1) 13.14 (10) 13.14 (14) 13.14 (15.1/2) +RM References: 13.14 (2) 13.14 (3/1) 13.14 (8.1/1) 13.14 (10) 13.14 (14) 13.14 (15.1/2) +@end itemize -@item +@geindex AI-0017 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0017 Freezing and incomplete types (0000-00-00)} -@cindex AI-0017 (Ada 2012 feature) -@noindent - So-called ``Taft-amendment types'' (i.e., types that are completed in package - bodies) are not frozen by the occurrence of bodies in the - enclosing declarative part. GNAT always implemented this properly. +So-called 'Taft-amendment types' (i.e., types that are completed in package +bodies) are not frozen by the occurrence of bodies in the +enclosing declarative part. GNAT always implemented this properly. + +RM References: 13.14 (3/1) +@end itemize -@noindent - RM References: 13.14 (3/1) +@geindex AI-0060 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0060 Extended definition of remote access types (0000-00-00)} -@cindex AI-0060 (Ada 2012 feature) -@noindent - This AI extends the definition of remote access types to include access - to limited, synchronized, protected or task class-wide interface types. - GNAT already implemented this extension. +This AI extends the definition of remote access types to include access +to limited, synchronized, protected or task class-wide interface types. +GNAT already implemented this extension. -@noindent - RM References: A (4) E.02.02 (9/1) E.02.02 (9.2/1) E.02.02 (14/2) E.02.02 (18) +RM References: A (4) E.02.02 (9/1) E.02.02 (9.2/1) E.02.02 (14/2) E.02.02 (18) +@end itemize -@item +@geindex AI-0114 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0114 Classification of letters (0000-00-00)} -@cindex AI-0114 (Ada 2012 feature) -@noindent - The code points 170 (@code{FEMININE ORDINAL INDICATOR}), - 181 (@code{MICRO SIGN}), and - 186 (@code{MASCULINE ORDINAL INDICATOR}) are technically considered - lower case letters by Unicode. - However, they are not allowed in identifiers, and they - return @code{False} to @code{Ada.Characters.Handling.Is_Letter/Is_Lower}. - This behavior is consistent with that defined in Ada 95. +The code points 170 (@cite{FEMININE ORDINAL INDICATOR}), +181 (@cite{MICRO SIGN}), and +186 (@cite{MASCULINE ORDINAL INDICATOR}) are technically considered +lower case letters by Unicode. +However, they are not allowed in identifiers, and they +return @cite{False} to @cite{Ada.Characters.Handling.Is_Letter/Is_Lower}. +This behavior is consistent with that defined in Ada 95. + +RM References: A.03.02 (59) A.04.06 (7) +@end itemize -@noindent - RM References: A.03.02 (59) A.04.06 (7) +@geindex AI-0185 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0185 Ada.Wide_[Wide_]Characters.Handling (2010-07-06)} -@cindex AI-0185 (Ada 2012 feature) -@noindent - Two new packages @code{Ada.Wide_[Wide_]Characters.Handling} provide - classification functions for @code{Wide_Character} and - @code{Wide_Wide_Character}, as well as providing - case folding routines for @code{Wide_[Wide_]Character} and - @code{Wide_[Wide_]String}. +Two new packages @cite{Ada.Wide_[Wide_]Characters.Handling} provide +classification functions for @cite{Wide_Character} and +@cite{Wide_Wide_Character}, as well as providing +case folding routines for @cite{Wide_[Wide_]Character} and +@cite{Wide_[Wide_]String}. -@noindent - RM References: A.03.05 (0) A.03.06 (0) +RM References: A.03.05 (0) A.03.06 (0) +@end itemize +@geindex AI-0031 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0031 Add From parameter to Find_Token (2010-07-25)} -@cindex AI-0031 (Ada 2012 feature) -@noindent - A new version of @code{Find_Token} is added to all relevant string packages, - with an extra parameter @code{From}. Instead of starting at the first - character of the string, the search for a matching Token starts at the - character indexed by the value of @code{From}. - These procedures are available in all versions of Ada - but if used in versions earlier than Ada 2012 they will generate a warning - that an Ada 2012 subprogram is being used. +A new version of @cite{Find_Token} is added to all relevant string packages, +with an extra parameter @cite{From}. Instead of starting at the first +character of the string, the search for a matching Token starts at the +character indexed by the value of @cite{From}. +These procedures are available in all versions of Ada +but if used in versions earlier than Ada 2012 they will generate a warning +that an Ada 2012 subprogram is being used. -@noindent - RM References: A.04.03 (16) A.04.03 (67) A.04.03 (68/1) A.04.04 (51) - A.04.05 (46) +RM References: A.04.03 (16) A.04.03 (67) A.04.03 (68/1) A.04.04 (51) +A.04.05 (46) +@end itemize +@geindex AI-0056 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0056 Index on null string returns zero (0000-00-00)} -@cindex AI-0056 (Ada 2012 feature) -@noindent - The wording in the Ada 2005 RM implied an incompatible handling of the - @code{Index} functions, resulting in raising an exception instead of - returning zero in some situations. - This was not intended and has been corrected. - GNAT always returned zero, and is thus consistent with this AI. +The wording in the Ada 2005 RM implied an incompatible handling of the +@cite{Index} functions, resulting in raising an exception instead of +returning zero in some situations. +This was not intended and has been corrected. +GNAT always returned zero, and is thus consistent with this AI. -@noindent - RM References: A.04.03 (56.2/2) A.04.03 (58.5/2) +RM References: A.04.03 (56.2/2) A.04.03 (58.5/2) +@end itemize +@geindex AI-0137 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0137 String encoding package (2010-03-25)} -@cindex AI-0137 (Ada 2012 feature) - -@noindent - The packages @code{Ada.Strings.UTF_Encoding}, together with its child - packages, @code{Conversions}, @code{Strings}, @code{Wide_Strings}, - and @code{Wide_Wide_Strings} have been - implemented. These packages (whose documentation can be found in the spec - files @file{a-stuten.ads}, @file{a-suenco.ads}, @file{a-suenst.ads}, - @file{a-suewst.ads}, @file{a-suezst.ads}) allow encoding and decoding of - @code{String}, @code{Wide_String}, and @code{Wide_Wide_String} - values using UTF coding schemes (including UTF-8, UTF-16LE, UTF-16BE, and - UTF-16), as well as conversions between the different UTF encodings. With - the exception of @code{Wide_Wide_Strings}, these packages are available in - Ada 95 and Ada 2005 mode as well as Ada 2012 mode. - The @code{Wide_Wide_Strings package} - is available in Ada 2005 mode as well as Ada 2012 mode (but not in Ada 95 - mode since it uses @code{Wide_Wide_Character}). - -@noindent - RM References: A.04.11 -@item +The packages @cite{Ada.Strings.UTF_Encoding}, together with its child +packages, @cite{Conversions}, @cite{Strings}, @cite{Wide_Strings}, +and @cite{Wide_Wide_Strings} have been +implemented. These packages (whose documentation can be found in the spec +files @code{a-stuten.ads}, @code{a-suenco.ads}, @code{a-suenst.ads}, +@code{a-suewst.ads}, @code{a-suezst.ads}) allow encoding and decoding of +@cite{String}, @cite{Wide_String}, and @cite{Wide_Wide_String} +values using UTF coding schemes (including UTF-8, UTF-16LE, UTF-16BE, and +UTF-16), as well as conversions between the different UTF encodings. With +the exception of @cite{Wide_Wide_Strings}, these packages are available in +Ada 95 and Ada 2005 mode as well as Ada 2012 mode. +The @cite{Wide_Wide_Strings package} +is available in Ada 2005 mode as well as Ada 2012 mode (but not in Ada 95 +mode since it uses @cite{Wide_Wide_Character}). + +RM References: A.04.11 +@end itemize + +@geindex AI-0038 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0038 Minor errors in Text_IO (0000-00-00)} -@cindex AI-0038 (Ada 2012 feature) -@noindent - These are minor errors in the description on three points. The intent on - all these points has always been clear, and GNAT has always implemented the - correct intended semantics. +These are minor errors in the description on three points. The intent on +all these points has always been clear, and GNAT has always implemented the +correct intended semantics. -@noindent - RM References: A.10.05 (37) A.10.07 (8/1) A.10.07 (10) A.10.07 (12) A.10.08 (10) A.10.08 (24) +RM References: A.10.05 (37) A.10.07 (8/1) A.10.07 (10) A.10.07 (12) A.10.08 (10) A.10.08 (24) +@end itemize -@item +@geindex AI-0044 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0044 Restrictions on container instantiations (0000-00-00)} -@cindex AI-0044 (Ada 2012 feature) -@noindent - This AI places restrictions on allowed instantiations of generic containers. - These restrictions are not checked by the compiler, so there is nothing to - change in the implementation. This affects only the RM documentation. +This AI places restrictions on allowed instantiations of generic containers. +These restrictions are not checked by the compiler, so there is nothing to +change in the implementation. This affects only the RM documentation. -@noindent - RM References: A.18 (4/2) A.18.02 (231/2) A.18.03 (145/2) A.18.06 (56/2) A.18.08 (66/2) A.18.09 (79/2) A.18.26 (5/2) A.18.26 (9/2) +RM References: A.18 (4/2) A.18.02 (231/2) A.18.03 (145/2) A.18.06 (56/2) A.18.08 (66/2) A.18.09 (79/2) A.18.26 (5/2) A.18.26 (9/2) +@end itemize -@item +@geindex AI-0127 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0127 Adding Locale Capabilities (2010-09-29)} -@cindex AI-0127 (Ada 2012 feature) -@noindent - This package provides an interface for identifying the current locale. +This package provides an interface for identifying the current locale. -@noindent - RM References: A.19 A.19.01 A.19.02 A.19.03 A.19.05 A.19.06 - A.19.07 A.19.08 A.19.09 A.19.10 A.19.11 A.19.12 A.19.13 +RM References: A.19 A.19.01 A.19.02 A.19.03 A.19.05 A.19.06 +A.19.07 A.19.08 A.19.09 A.19.10 A.19.11 A.19.12 A.19.13 +@end itemize +@geindex AI-0002 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0002 Export C with unconstrained arrays (0000-00-00)} -@cindex AI-0002 (Ada 2012 feature) -@noindent - The compiler is not required to support exporting an Ada subprogram with - convention C if there are parameters or a return type of an unconstrained - array type (such as @code{String}). GNAT allows such declarations but - generates warnings. It is possible, but complicated, to write the - corresponding C code and certainly such code would be specific to GNAT and - non-portable. +The compiler is not required to support exporting an Ada subprogram with +convention C if there are parameters or a return type of an unconstrained +array type (such as @cite{String}). GNAT allows such declarations but +generates warnings. It is possible, but complicated, to write the +corresponding C code and certainly such code would be specific to GNAT and +non-portable. -@noindent - RM References: B.01 (17) B.03 (62) B.03 (71.1/2) +RM References: B.01 (17) B.03 (62) B.03 (71.1/2) +@end itemize +@geindex AI05-0216 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0216 No_Task_Hierarchy forbids local tasks (0000-00-00)} -@cindex AI05-0216 (Ada 2012 feature) -@noindent - It is clearly the intention that @code{No_Task_Hierarchy} is intended to - forbid tasks declared locally within subprograms, or functions returning task - objects, and that is the implementation that GNAT has always provided. - However the language in the RM was not sufficiently clear on this point. - Thus this is a documentation change in the RM only. +It is clearly the intention that @cite{No_Task_Hierarchy} is intended to +forbid tasks declared locally within subprograms, or functions returning task +objects, and that is the implementation that GNAT has always provided. +However the language in the RM was not sufficiently clear on this point. +Thus this is a documentation change in the RM only. -@noindent - RM References: D.07 (3/3) +RM References: D.07 (3/3) +@end itemize -@item +@geindex AI-0211 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0211 No_Relative_Delays forbids Set_Handler use (2010-07-09)} -@cindex AI-0211 (Ada 2012 feature) -@noindent - The restriction @code{No_Relative_Delays} forbids any calls to the subprogram - @code{Ada.Real_Time.Timing_Events.Set_Handler}. +The restriction @cite{No_Relative_Delays} forbids any calls to the subprogram +@cite{Ada.Real_Time.Timing_Events.Set_Handler}. -@noindent - RM References: D.07 (5) D.07 (10/2) D.07 (10.4/2) D.07 (10.7/2) +RM References: D.07 (5) D.07 (10/2) D.07 (10.4/2) D.07 (10.7/2) +@end itemize -@item +@geindex AI-0190 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0190 pragma Default_Storage_Pool (2010-09-15)} -@cindex AI-0190 (Ada 2012 feature) -@noindent - This AI introduces a new pragma @code{Default_Storage_Pool}, which can be - used to control storage pools globally. - In particular, you can force every access - type that is used for allocation (@b{new}) to have an explicit storage pool, - or you can declare a pool globally to be used for all access types that lack - an explicit one. +This AI introduces a new pragma @cite{Default_Storage_Pool}, which can be +used to control storage pools globally. +In particular, you can force every access +type that is used for allocation (@strong{new}) to have an explicit storage pool, +or you can declare a pool globally to be used for all access types that lack +an explicit one. -@noindent - RM References: D.07 (8) +RM References: D.07 (8) +@end itemize -@item +@geindex AI-0189 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0189 No_Allocators_After_Elaboration (2010-01-23)} -@cindex AI-0189 (Ada 2012 feature) -@noindent - This AI introduces a new restriction @code{No_Allocators_After_Elaboration}, - which says that no dynamic allocation will occur once elaboration is - completed. - In general this requires a run-time check, which is not required, and which - GNAT does not attempt. But the static cases of allocators in a task body or - in the body of the main program are detected and flagged at compile or bind - time. +This AI introduces a new restriction @cite{No_Allocators_After_Elaboration}, +which says that no dynamic allocation will occur once elaboration is +completed. +In general this requires a run-time check, which is not required, and which +GNAT does not attempt. But the static cases of allocators in a task body or +in the body of the main program are detected and flagged at compile or bind +time. -@noindent - RM References: D.07 (19.1/2) H.04 (23.3/2) +RM References: D.07 (19.1/2) H.04 (23.3/2) +@end itemize -@item +@geindex AI-0171 (Ada 2012 feature) + + +@itemize * + +@item @emph{AI-0171 Pragma CPU and Ravenscar Profile (2010-09-24)} -@cindex AI-0171 (Ada 2012 feature) -@noindent - A new package @code{System.Multiprocessors} is added, together with the - definition of pragma @code{CPU} for controlling task affinity. A new no - dependence restriction, on @code{System.Multiprocessors.Dispatching_Domains}, - is added to the Ravenscar profile. +A new package @cite{System.Multiprocessors} is added, together with the +definition of pragma @cite{CPU} for controlling task affinity. A new no +dependence restriction, on @cite{System.Multiprocessors.Dispatching_Domains}, +is added to the Ravenscar profile. -@noindent - RM References: D.13.01 (4/2) D.16 +RM References: D.13.01 (4/2) D.16 +@end itemize +@geindex AI-0210 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0210 Correct Timing_Events metric (0000-00-00)} -@cindex AI-0210 (Ada 2012 feature) -@noindent - This is a documentation only issue regarding wording of metric requirements, - that does not affect the implementation of the compiler. +This is a documentation only issue regarding wording of metric requirements, +that does not affect the implementation of the compiler. -@noindent - RM References: D.15 (24/2) +RM References: D.15 (24/2) +@end itemize +@geindex AI-0206 (Ada 2012 feature) -@item + +@itemize * + +@item @emph{AI-0206 Remote types packages and preelaborate (2010-07-24)} -@cindex AI-0206 (Ada 2012 feature) -@noindent - Remote types packages are now allowed to depend on preelaborated packages. - This was formerly considered illegal. +Remote types packages are now allowed to depend on preelaborated packages. +This was formerly considered illegal. -@noindent - RM References: E.02.02 (6) +RM References: E.02.02 (6) +@end itemize +@geindex AI-0152 (Ada 2012 feature) -@item +@itemize * + +@item @emph{AI-0152 Restriction No_Anonymous_Allocators (2010-09-08)} -@cindex AI-0152 (Ada 2012 feature) -@noindent - Restriction @code{No_Anonymous_Allocators} prevents the use of allocators - where the type of the returned value is an anonymous access type. +Restriction @cite{No_Anonymous_Allocators} prevents the use of allocators +where the type of the returned value is an anonymous access type. -@noindent - RM References: H.04 (8/1) +RM References: H.04 (8/1) @end itemize - -@node Obsolescent Features +@node Obsolescent Features,Compatibility and Porting Guide,Implementation of Ada 2012 Features,Top +@anchor{gnat_rm/obsolescent_features id1}@anchor{3c7}@anchor{gnat_rm/obsolescent_features doc}@anchor{3c8}@anchor{gnat_rm/obsolescent_features obsolescent-features}@anchor{15} @chapter Obsolescent Features -@noindent + This chapter describes features that are provided by GNAT, but are considered obsolescent since there are preferred ways of achieving the same effect. These features are provided solely for historical compatibility purposes. @menu -* pragma No_Run_Time:: -* pragma Ravenscar:: -* pragma Restricted_Run_Time:: -* pragma Task_Info:: -* System.Task_Info (s-tasinf.ads):: +* pragma No_Run_Time:: +* pragma Ravenscar:: +* pragma Restricted_Run_Time:: +* pragma Task_Info:: +* package System.Task_Info (s-tasinf.ads): package System Task_Info s-tasinf ads. + @end menu -@node pragma No_Run_Time +@node pragma No_Run_Time,pragma Ravenscar,,Obsolescent Features +@anchor{gnat_rm/obsolescent_features id2}@anchor{3c9}@anchor{gnat_rm/obsolescent_features pragma-no-run-time}@anchor{3ca} @section pragma No_Run_Time -The pragma @code{No_Run_Time} is used to achieve an affect similar + +The pragma @cite{No_Run_Time} is used to achieve an affect similar to the use of the "Zero Foot Print" configurable run time, but without requiring a specially configured run time. The result of using this pragma, which must be used for all units in a partition, is to restrict @@ -23390,64 +27312,1303 @@ the use of any language features requiring run-time support code. The preferred usage is to use an appropriately configured run-time that includes just those features that are to be made accessible. -@node pragma Ravenscar +@node pragma Ravenscar,pragma Restricted_Run_Time,pragma No_Run_Time,Obsolescent Features +@anchor{gnat_rm/obsolescent_features id3}@anchor{3cb}@anchor{gnat_rm/obsolescent_features pragma-ravenscar}@anchor{3cc} @section pragma Ravenscar -The pragma @code{Ravenscar} has exactly the same effect as pragma -@code{Profile (Ravenscar)}. The latter usage is preferred since it + +The pragma @cite{Ravenscar} has exactly the same effect as pragma +@cite{Profile (Ravenscar)}. The latter usage is preferred since it is part of the new Ada 2005 standard. -@node pragma Restricted_Run_Time +@node pragma Restricted_Run_Time,pragma Task_Info,pragma Ravenscar,Obsolescent Features +@anchor{gnat_rm/obsolescent_features pragma-restricted-run-time}@anchor{3cd}@anchor{gnat_rm/obsolescent_features id4}@anchor{3ce} @section pragma Restricted_Run_Time -The pragma @code{Restricted_Run_Time} has exactly the same effect as -pragma @code{Profile (Restricted)}. The latter usage is -preferred since the Ada 2005 pragma @code{Profile} is intended for + +The pragma @cite{Restricted_Run_Time} has exactly the same effect as +pragma @cite{Profile (Restricted)}. The latter usage is +preferred since the Ada 2005 pragma @cite{Profile} is intended for this kind of implementation dependent addition. -@node pragma Task_Info +@node pragma Task_Info,package System Task_Info s-tasinf ads,pragma Restricted_Run_Time,Obsolescent Features +@anchor{gnat_rm/obsolescent_features pragma-task-info}@anchor{3cf}@anchor{gnat_rm/obsolescent_features id5}@anchor{3d0} @section pragma Task_Info -The functionality provided by pragma @code{Task_Info} is now part of the -Ada language. The @code{CPU} aspect and the package -@code{System.Multiprocessors} offer a less system-dependent way to specify + +The functionality provided by pragma @cite{Task_Info} is now part of the +Ada language. The @cite{CPU} aspect and the package +@cite{System.Multiprocessors} offer a less system-dependent way to specify task affinity or to query the number of processsors. -@noindent Syntax -@smallexample @c ada +@example pragma Task_Info (EXPRESSION); -@end smallexample +@end example -@noindent This pragma appears within a task definition (like pragma -@code{Priority}) and applies to the task in which it appears. The -argument must be of type @code{System.Task_Info.Task_Info_Type}. -The @code{Task_Info} pragma provides system dependent control over +@cite{Priority}) and applies to the task in which it appears. The +argument must be of type @cite{System.Task_Info.Task_Info_Type}. +The @cite{Task_Info} pragma provides system dependent control over aspects of tasking implementation, for example, the ability to map tasks to specific processors. For details on the facilities available for the version of GNAT that you are using, see the documentation in the spec of package System.Task_Info in the runtime library. -@node System.Task_Info (s-tasinf.ads) -@section package System.Task_Info (@file{s-tasinf.ads}) +@node package System Task_Info s-tasinf ads,,pragma Task_Info,Obsolescent Features +@anchor{gnat_rm/obsolescent_features package-system-task-info}@anchor{3d1}@anchor{gnat_rm/obsolescent_features package-system-task-info-s-tasinf-ads}@anchor{3d2} +@section package System.Task_Info (@code{s-tasinf.ads}) + -@noindent This package provides target dependent functionality that is used -to support the @code{Task_Info} pragma. The predefined Ada package - @code{System.Multiprocessors} and the @code{CPU} aspect now provide a -standard replacement for GNAT's @code{Task_Info} functionality. +to support the @cite{Task_Info} pragma. The predefined Ada package +@cite{System.Multiprocessors} and the @cite{CPU} aspect now provide a +standard replacement for GNAT's @cite{Task_Info} functionality. + +@node Compatibility and Porting Guide,GNU Free Documentation License,Obsolescent Features,Top +@anchor{gnat_rm/compatibility_and_porting_guide compatibility-and-porting-guide}@anchor{16}@anchor{gnat_rm/compatibility_and_porting_guide doc}@anchor{3d3}@anchor{gnat_rm/compatibility_and_porting_guide id1}@anchor{3d4} +@chapter Compatibility and Porting Guide + + +This chapter presents some guidelines for developing portable Ada code, +describes the compatibility issues that may arise between +GNAT and other Ada compilation systems (including those for Ada 83), +and shows how GNAT can expedite porting +applications developed in other Ada environments. + +@menu +* Writing Portable Fixed-Point Declarations:: +* Compatibility with Ada 83:: +* Compatibility between Ada 95 and Ada 2005:: +* Implementation-dependent characteristics:: +* Compatibility with Other Ada Systems:: +* Representation Clauses:: +* Compatibility with HP Ada 83:: + +@end menu + +@node Writing Portable Fixed-Point Declarations,Compatibility with Ada 83,,Compatibility and Porting Guide +@anchor{gnat_rm/compatibility_and_porting_guide id2}@anchor{3d5}@anchor{gnat_rm/compatibility_and_porting_guide writing-portable-fixed-point-declarations}@anchor{3d6} +@section Writing Portable Fixed-Point Declarations + + +The Ada Reference Manual gives an implementation freedom to choose bounds +that are narrower by @cite{Small} from the given bounds. +For example, if we write + +@example +type F1 is delta 1.0 range -128.0 .. +128.0; +@end example + +then the implementation is allowed to choose -128.0 .. +127.0 if it +likes, but is not required to do so. + +This leads to possible portability problems, so let's have a closer +look at this, and figure out how to avoid these problems. + +First, why does this freedom exist, and why would an implementation +take advantage of it? To answer this, take a closer look at the type +declaration for @cite{F1} above. If the compiler uses the given bounds, +it would need 9 bits to hold the largest positive value (and typically +that means 16 bits on all machines). But if the implementation chooses +the +127.0 bound then it can fit values of the type in 8 bits. + +Why not make the user write +127.0 if that's what is wanted? +The rationale is that if you are thinking of fixed point +as a kind of 'poor man's floating-point', then you don't want +to be thinking about the scaled integers that are used in its +representation. Let's take another example: + +@example +type F2 is delta 2.0**(-15) range -1.0 .. +1.0; +@end example + +Looking at this declaration, it seems casually as though +it should fit in 16 bits, but again that extra positive value ++1.0 has the scaled integer equivalent of 2**15 which is one too +big for signed 16 bits. The implementation can treat this as: + +@example +type F2 is delta 2.0**(-15) range -1.0 .. +1.0-(2.0**(-15)); +@end example + +and the Ada language design team felt that this was too annoying +to require. We don't need to debate this decision at this point, +since it is well established (the rule about narrowing the ranges +dates to Ada 83). + +But the important point is that an implementation is not required +to do this narrowing, so we have a potential portability problem. +We could imagine three types of implementation: + + +@enumerate a + +@item +those that narrow the range automatically if they can figure +out that the narrower range will allow storage in a smaller machine unit, + +@item +those that will narrow only if forced to by a @cite{'Size} clause, and + +@item +those that will never narrow. +@end enumerate + +Now if we are language theoreticians, we can imagine a fourth +approach: to narrow all the time, e.g. to treat + +@example +type F3 is delta 1.0 range -10.0 .. +23.0; +@end example + +as though it had been written: + +@example +type F3 is delta 1.0 range -9.0 .. +22.0; +@end example + +But although technically allowed, such a behavior would be hostile and silly, +and no real compiler would do this. All real compilers will fall into one of +the categories (a), (b) or (c) above. + +So, how do you get the compiler to do what you want? The answer is give the +actual bounds you want, and then use a @cite{'Small} clause and a +@cite{'Size} clause to absolutely pin down what the compiler does. +E.g., for @cite{F2} above, we will write: + +@example +My_Small : constant := 2.0**(-15); +My_First : constant := -1.0; +My_Last : constant := +1.0 - My_Small; + +type F2 is delta My_Small range My_First .. My_Last; +@end example + +and then add + +@example +for F2'Small use my_Small; +for F2'Size use 16; +@end example + +In practice all compilers will do the same thing here and will give you +what you want, so the above declarations are fully portable. If you really +want to play language lawyer and guard against ludicrous behavior by the +compiler you could add + +@example +Test1 : constant := 1 / Boolean'Pos (F2'First = My_First); +Test2 : constant := 1 / Boolean'Pos (F2'Last = My_Last); +@end example + +One or other or both are allowed to be illegal if the compiler is +behaving in a silly manner, but at least the silly compiler will not +get away with silently messing with your (very clear) intentions. + +If you follow this scheme you will be guaranteed that your fixed-point +types will be portable. + +@node Compatibility with Ada 83,Compatibility between Ada 95 and Ada 2005,Writing Portable Fixed-Point Declarations,Compatibility and Porting Guide +@anchor{gnat_rm/compatibility_and_porting_guide compatibility-with-ada-83}@anchor{3d7}@anchor{gnat_rm/compatibility_and_porting_guide id3}@anchor{3d8} +@section Compatibility with Ada 83 + + +@geindex Compatibility (between Ada 83 and Ada 95 / Ada 2005 / Ada 2012) + +Ada 95 and the subsequent revisions Ada 2005 and Ada 2012 +are highly upwards compatible with Ada 83. In +particular, the design intention was that the difficulties associated +with moving from Ada 83 to later versions of the standard should be no greater +than those that occur when moving from one Ada 83 system to another. + +However, there are a number of points at which there are minor +incompatibilities. The @cite{Ada 95 Annotated Reference Manual} contains +full details of these issues as they relate to Ada 95, +and should be consulted for a complete treatment. +In practice the +following subsections treat the most likely issues to be encountered. + +@menu +* Legal Ada 83 programs that are illegal in Ada 95:: +* More deterministic semantics:: +* Changed semantics:: +* Other language compatibility issues:: + +@end menu + +@node Legal Ada 83 programs that are illegal in Ada 95,More deterministic semantics,,Compatibility with Ada 83 +@anchor{gnat_rm/compatibility_and_porting_guide id4}@anchor{3d9}@anchor{gnat_rm/compatibility_and_porting_guide legal-ada-83-programs-that-are-illegal-in-ada-95}@anchor{3da} +@subsection Legal Ada 83 programs that are illegal in Ada 95 + + +Some legal Ada 83 programs are illegal (i.e., they will fail to compile) in +Ada 95 and later versions of the standard: + + +@itemize * + +@item +@emph{Character literals} + +Some uses of character literals are ambiguous. Since Ada 95 has introduced +@cite{Wide_Character} as a new predefined character type, some uses of +character literals that were legal in Ada 83 are illegal in Ada 95. +For example: + +@example +for Char in 'A' .. 'Z' loop ... end loop; +@end example + +The problem is that 'A' and 'Z' could be from either +@cite{Character} or @cite{Wide_Character}. The simplest correction +is to make the type explicit; e.g.: + +@example +for Char in Character range 'A' .. 'Z' loop ... end loop; +@end example + +@item +@emph{New reserved words} + +The identifiers @cite{abstract}, @cite{aliased}, @cite{protected}, +@cite{requeue}, @cite{tagged}, and @cite{until} are reserved in Ada 95. +Existing Ada 83 code using any of these identifiers must be edited to +use some alternative name. + +@item +@emph{Freezing rules} + +The rules in Ada 95 are slightly different with regard to the point at +which entities are frozen, and representation pragmas and clauses are +not permitted past the freeze point. This shows up most typically in +the form of an error message complaining that a representation item +appears too late, and the appropriate corrective action is to move +the item nearer to the declaration of the entity to which it refers. + +A particular case is that representation pragmas +cannot be applied to a subprogram body. If necessary, a separate subprogram +declaration must be introduced to which the pragma can be applied. + +@item +@emph{Optional bodies for library packages} + +In Ada 83, a package that did not require a package body was nevertheless +allowed to have one. This lead to certain surprises in compiling large +systems (situations in which the body could be unexpectedly ignored by the +binder). In Ada 95, if a package does not require a body then it is not +permitted to have a body. To fix this problem, simply remove a redundant +body if it is empty, or, if it is non-empty, introduce a dummy declaration +into the spec that makes the body required. One approach is to add a private +part to the package declaration (if necessary), and define a parameterless +procedure called @cite{Requires_Body}, which must then be given a dummy +procedure body in the package body, which then becomes required. +Another approach (assuming that this does not introduce elaboration +circularities) is to add an @cite{Elaborate_Body} pragma to the package spec, +since one effect of this pragma is to require the presence of a package body. + +@item +@emph{Numeric_Error is the same exception as Constraint_Error} + +In Ada 95, the exception @cite{Numeric_Error} is a renaming of @cite{Constraint_Error}. +This means that it is illegal to have separate exception handlers for +the two exceptions. The fix is simply to remove the handler for the +@cite{Numeric_Error} case (since even in Ada 83, a compiler was free to raise +@cite{Constraint_Error} in place of @cite{Numeric_Error} in all cases). + +@item +@emph{Indefinite subtypes in generics} + +In Ada 83, it was permissible to pass an indefinite type (e.g, @cite{String}) +as the actual for a generic formal private type, but then the instantiation +would be illegal if there were any instances of declarations of variables +of this type in the generic body. In Ada 95, to avoid this clear violation +of the methodological principle known as the 'contract model', +the generic declaration explicitly indicates whether +or not such instantiations are permitted. If a generic formal parameter +has explicit unknown discriminants, indicated by using @cite{(<>)} after the +subtype name, then it can be instantiated with indefinite types, but no +stand-alone variables can be declared of this type. Any attempt to declare +such a variable will result in an illegality at the time the generic is +declared. If the @cite{(<>)} notation is not used, then it is illegal +to instantiate the generic with an indefinite type. +This is the potential incompatibility issue when porting Ada 83 code to Ada 95. +It will show up as a compile time error, and +the fix is usually simply to add the @cite{(<>)} to the generic declaration. +@end itemize + +@node More deterministic semantics,Changed semantics,Legal Ada 83 programs that are illegal in Ada 95,Compatibility with Ada 83 +@anchor{gnat_rm/compatibility_and_porting_guide more-deterministic-semantics}@anchor{3db}@anchor{gnat_rm/compatibility_and_porting_guide id5}@anchor{3dc} +@subsection More deterministic semantics + + + +@itemize * + +@item +@emph{Conversions} + +Conversions from real types to integer types round away from 0. In Ada 83 +the conversion Integer(2.5) could deliver either 2 or 3 as its value. This +implementation freedom was intended to support unbiased rounding in +statistical applications, but in practice it interfered with portability. +In Ada 95 the conversion semantics are unambiguous, and rounding away from 0 +is required. Numeric code may be affected by this change in semantics. +Note, though, that this issue is no worse than already existed in Ada 83 +when porting code from one vendor to another. + +@item +@emph{Tasking} + +The Real-Time Annex introduces a set of policies that define the behavior of +features that were implementation dependent in Ada 83, such as the order in +which open select branches are executed. +@end itemize + +@node Changed semantics,Other language compatibility issues,More deterministic semantics,Compatibility with Ada 83 +@anchor{gnat_rm/compatibility_and_porting_guide id6}@anchor{3dd}@anchor{gnat_rm/compatibility_and_porting_guide changed-semantics}@anchor{3de} +@subsection Changed semantics + + +The worst kind of incompatibility is one where a program that is legal in +Ada 83 is also legal in Ada 95 but can have an effect in Ada 95 that was not +possible in Ada 83. Fortunately this is extremely rare, but the one +situation that you should be alert to is the change in the predefined type +@cite{Character} from 7-bit ASCII to 8-bit Latin-1. + +@quotation -@include fdl.texi -@c GNU Free Documentation License +@geindex Latin-1 +@end quotation + + +@itemize * + +@item +@emph{Range of type `Character`} + +The range of @cite{Standard.Character} is now the full 256 characters +of Latin-1, whereas in most Ada 83 implementations it was restricted +to 128 characters. Although some of the effects of +this change will be manifest in compile-time rejection of legal +Ada 83 programs it is possible for a working Ada 83 program to have +a different effect in Ada 95, one that was not permitted in Ada 83. +As an example, the expression +@cite{Character'Pos(Character'Last)} returned @cite{127} in Ada 83 and now +delivers @cite{255} as its value. +In general, you should look at the logic of any +character-processing Ada 83 program and see whether it needs to be adapted +to work correctly with Latin-1. Note that the predefined Ada 95 API has a +character handling package that may be relevant if code needs to be adapted +to account for the additional Latin-1 elements. +The desirable fix is to +modify the program to accommodate the full character set, but in some cases +it may be convenient to define a subtype or derived type of Character that +covers only the restricted range. +@end itemize + +@node Other language compatibility issues,,Changed semantics,Compatibility with Ada 83 +@anchor{gnat_rm/compatibility_and_porting_guide other-language-compatibility-issues}@anchor{3df}@anchor{gnat_rm/compatibility_and_porting_guide id7}@anchor{3e0} +@subsection Other language compatibility issues + + + +@itemize * + +@item +@emph{-gnat83} switch + +All implementations of GNAT provide a switch that causes GNAT to operate +in Ada 83 mode. In this mode, some but not all compatibility problems +of the type described above are handled automatically. For example, the +new reserved words introduced in Ada 95 and Ada 2005 are treated simply +as identifiers as in Ada 83. However, +in practice, it is usually advisable to make the necessary modifications +to the program to remove the need for using this switch. +See the @cite{Compiling Different Versions of Ada} section in +the @cite{GNAT User's Guide}. + +@item +Support for removed Ada 83 pragmas and attributes + +A number of pragmas and attributes from Ada 83 were removed from Ada 95, +generally because they were replaced by other mechanisms. Ada 95 and Ada 2005 +compilers are allowed, but not required, to implement these missing +elements. In contrast with some other compilers, GNAT implements all +such pragmas and attributes, eliminating this compatibility concern. These +include @cite{pragma Interface} and the floating point type attributes +(@cite{Emax}, @cite{Mantissa}, etc.), among other items. +@end itemize + +@node Compatibility between Ada 95 and Ada 2005,Implementation-dependent characteristics,Compatibility with Ada 83,Compatibility and Porting Guide +@anchor{gnat_rm/compatibility_and_porting_guide compatibility-between-ada-95-and-ada-2005}@anchor{3e1}@anchor{gnat_rm/compatibility_and_porting_guide id8}@anchor{3e2} +@section Compatibility between Ada 95 and Ada 2005 + + +@geindex Compatibility between Ada 95 and Ada 2005 + +Although Ada 2005 was designed to be upwards compatible with Ada 95, there are +a number of incompatibilities. Several are enumerated below; +for a complete description please see the +@cite{Annotated Ada 2005 Reference Manual}, or section 9.1.1 in +@cite{Rationale for Ada 2005}. + + +@itemize * + +@item +@emph{New reserved words.} + +The words @cite{interface}, @cite{overriding} and @cite{synchronized} are +reserved in Ada 2005. +A pre-Ada 2005 program that uses any of these as an identifier will be +illegal. + +@item +@emph{New declarations in predefined packages.} + +A number of packages in the predefined environment contain new declarations: +@cite{Ada.Exceptions}, @cite{Ada.Real_Time}, @cite{Ada.Strings}, +@cite{Ada.Strings.Fixed}, @cite{Ada.Strings.Bounded}, +@cite{Ada.Strings.Unbounded}, @cite{Ada.Strings.Wide_Fixed}, +@cite{Ada.Strings.Wide_Bounded}, @cite{Ada.Strings.Wide_Unbounded}, +@cite{Ada.Tags}, @cite{Ada.Text_IO}, and @cite{Interfaces.C}. +If an Ada 95 program does a @cite{with} and @cite{use} of any of these +packages, the new declarations may cause name clashes. + +@item +@emph{Access parameters.} + +A nondispatching subprogram with an access parameter cannot be renamed +as a dispatching operation. This was permitted in Ada 95. + +@item +@emph{Access types, discriminants, and constraints.} + +Rule changes in this area have led to some incompatibilities; for example, +constrained subtypes of some access types are not permitted in Ada 2005. + +@item +@emph{Aggregates for limited types.} + +The allowance of aggregates for limited types in Ada 2005 raises the +possibility of ambiguities in legal Ada 95 programs, since additional types +now need to be considered in expression resolution. + +@item +@emph{Fixed-point multiplication and division.} + +Certain expressions involving '*' or '/' for a fixed-point type, which +were legal in Ada 95 and invoked the predefined versions of these operations, +are now ambiguous. +The ambiguity may be resolved either by applying a type conversion to the +expression, or by explicitly invoking the operation from package +@cite{Standard}. + +@item +@emph{Return-by-reference types.} + +The Ada 95 return-by-reference mechanism has been removed. Instead, the user +can declare a function returning a value from an anonymous access type. +@end itemize + +@node Implementation-dependent characteristics,Compatibility with Other Ada Systems,Compatibility between Ada 95 and Ada 2005,Compatibility and Porting Guide +@anchor{gnat_rm/compatibility_and_porting_guide implementation-dependent-characteristics}@anchor{3e3}@anchor{gnat_rm/compatibility_and_porting_guide id9}@anchor{3e4} +@section Implementation-dependent characteristics + + +Although the Ada language defines the semantics of each construct as +precisely as practical, in some situations (for example for reasons of +efficiency, or where the effect is heavily dependent on the host or target +platform) the implementation is allowed some freedom. In porting Ada 83 +code to GNAT, you need to be aware of whether / how the existing code +exercised such implementation dependencies. Such characteristics fall into +several categories, and GNAT offers specific support in assisting the +transition from certain Ada 83 compilers. + +@menu +* Implementation-defined pragmas:: +* Implementation-defined attributes:: +* Libraries:: +* Elaboration order:: +* Target-specific aspects:: + +@end menu + +@node Implementation-defined pragmas,Implementation-defined attributes,,Implementation-dependent characteristics +@anchor{gnat_rm/compatibility_and_porting_guide implementation-defined-pragmas}@anchor{3e5}@anchor{gnat_rm/compatibility_and_porting_guide id10}@anchor{3e6} +@subsection Implementation-defined pragmas + + +Ada compilers are allowed to supplement the language-defined pragmas, and +these are a potential source of non-portability. All GNAT-defined pragmas +are described in the @cite{Implementation Defined Pragmas} chapter of the +@cite{GNAT Reference Manual}, and these include several that are specifically +intended to correspond to other vendors' Ada 83 pragmas. +For migrating from VADS, the pragma @cite{Use_VADS_Size} may be useful. +For compatibility with HP Ada 83, GNAT supplies the pragmas +@cite{Extend_System}, @cite{Ident}, @cite{Inline_Generic}, +@cite{Interface_Name}, @cite{Passive}, @cite{Suppress_All}, +and @cite{Volatile}. +Other relevant pragmas include @cite{External} and @cite{Link_With}. +Some vendor-specific +Ada 83 pragmas (@cite{Share_Generic}, @cite{Subtitle}, and @cite{Title}) are +recognized, thus +avoiding compiler rejection of units that contain such pragmas; they are not +relevant in a GNAT context and hence are not otherwise implemented. + +@node Implementation-defined attributes,Libraries,Implementation-defined pragmas,Implementation-dependent characteristics +@anchor{gnat_rm/compatibility_and_porting_guide id11}@anchor{3e7}@anchor{gnat_rm/compatibility_and_porting_guide implementation-defined-attributes}@anchor{3e8} +@subsection Implementation-defined attributes + + +Analogous to pragmas, the set of attributes may be extended by an +implementation. All GNAT-defined attributes are described in +@cite{Implementation Defined Attributes} section of the +@cite{GNAT Reference Manual}, and these include several that are specifically intended +to correspond to other vendors' Ada 83 attributes. For migrating from VADS, +the attribute @cite{VADS_Size} may be useful. For compatibility with HP +Ada 83, GNAT supplies the attributes @cite{Bit}, @cite{Machine_Size} and +@cite{Type_Class}. + +@node Libraries,Elaboration order,Implementation-defined attributes,Implementation-dependent characteristics +@anchor{gnat_rm/compatibility_and_porting_guide libraries}@anchor{3e9}@anchor{gnat_rm/compatibility_and_porting_guide id12}@anchor{3ea} +@subsection Libraries + + +Vendors may supply libraries to supplement the standard Ada API. If Ada 83 +code uses vendor-specific libraries then there are several ways to manage +this in Ada 95 and later versions of the standard: + + +@itemize * + +@item +If the source code for the libraries (specs and bodies) are +available, then the libraries can be migrated in the same way as the +application. + +@item +If the source code for the specs but not the bodies are +available, then you can reimplement the bodies. + +@item +Some features introduced by Ada 95 obviate the need for library support. For +example most Ada 83 vendors supplied a package for unsigned integers. The +Ada 95 modular type feature is the preferred way to handle this need, so +instead of migrating or reimplementing the unsigned integer package it may +be preferable to retrofit the application using modular types. +@end itemize + +@node Elaboration order,Target-specific aspects,Libraries,Implementation-dependent characteristics +@anchor{gnat_rm/compatibility_and_porting_guide elaboration-order}@anchor{3eb}@anchor{gnat_rm/compatibility_and_porting_guide id13}@anchor{3ec} +@subsection Elaboration order + + +The implementation can choose any elaboration order consistent with the unit +dependency relationship. This freedom means that some orders can result in +Program_Error being raised due to an 'Access Before Elaboration': an attempt +to invoke a subprogram its body has been elaborated, or to instantiate a +generic before the generic body has been elaborated. By default GNAT +attempts to choose a safe order (one that will not encounter access before +elaboration problems) by implicitly inserting @cite{Elaborate} or +@cite{Elaborate_All} pragmas where +needed. However, this can lead to the creation of elaboration circularities +and a resulting rejection of the program by gnatbind. This issue is +thoroughly described in the @cite{Elaboration Order Handling in GNAT} appendix +in the @cite{GNAT User's Guide}. +In brief, there are several +ways to deal with this situation: + + +@itemize * + +@item +Modify the program to eliminate the circularities, e.g., by moving +elaboration-time code into explicitly-invoked procedures + +@item +Constrain the elaboration order by including explicit @cite{Elaborate_Body} or +@cite{Elaborate} pragmas, and then inhibit the generation of implicit +@cite{Elaborate_All} +pragmas either globally (as an effect of the @emph{-gnatE} switch) or locally +(by selectively suppressing elaboration checks via pragma +@cite{Suppress(Elaboration_Check)} when it is safe to do so). +@end itemize + +@node Target-specific aspects,,Elaboration order,Implementation-dependent characteristics +@anchor{gnat_rm/compatibility_and_porting_guide target-specific-aspects}@anchor{3ed}@anchor{gnat_rm/compatibility_and_porting_guide id14}@anchor{3ee} +@subsection Target-specific aspects -@node Concept Index + +Low-level applications need to deal with machine addresses, data +representations, interfacing with assembler code, and similar issues. If +such an Ada 83 application is being ported to different target hardware (for +example where the byte endianness has changed) then you will need to +carefully examine the program logic; the porting effort will heavily depend +on the robustness of the original design. Moreover, Ada 95 (and thus +Ada 2005 and Ada 2012) are sometimes +incompatible with typical Ada 83 compiler practices regarding implicit +packing, the meaning of the Size attribute, and the size of access values. +GNAT's approach to these issues is described in @ref{3ef,,Representation Clauses}. + +@node Compatibility with Other Ada Systems,Representation Clauses,Implementation-dependent characteristics,Compatibility and Porting Guide +@anchor{gnat_rm/compatibility_and_porting_guide id15}@anchor{3f0}@anchor{gnat_rm/compatibility_and_porting_guide compatibility-with-other-ada-systems}@anchor{3f1} +@section Compatibility with Other Ada Systems + + +If programs avoid the use of implementation dependent and +implementation defined features, as documented in the +@cite{Ada Reference Manual}, there should be a high degree of portability between +GNAT and other Ada systems. The following are specific items which +have proved troublesome in moving Ada 95 programs from GNAT to other Ada 95 +compilers, but do not affect porting code to GNAT. +(As of January 2007, GNAT is the only compiler available for Ada 2005; +the following issues may or may not arise for Ada 2005 programs +when other compilers appear.) + + +@itemize * + +@item +@emph{Ada 83 Pragmas and Attributes} + +Ada 95 compilers are allowed, but not required, to implement the missing +Ada 83 pragmas and attributes that are no longer defined in Ada 95. +GNAT implements all such pragmas and attributes, eliminating this as +a compatibility concern, but some other Ada 95 compilers reject these +pragmas and attributes. + +@item +@emph{Specialized Needs Annexes} + +GNAT implements the full set of special needs annexes. At the +current time, it is the only Ada 95 compiler to do so. This means that +programs making use of these features may not be portable to other Ada +95 compilation systems. + +@item +@emph{Representation Clauses} + +Some other Ada 95 compilers implement only the minimal set of +representation clauses required by the Ada 95 reference manual. GNAT goes +far beyond this minimal set, as described in the next section. +@end itemize + +@node Representation Clauses,Compatibility with HP Ada 83,Compatibility with Other Ada Systems,Compatibility and Porting Guide +@anchor{gnat_rm/compatibility_and_porting_guide representation-clauses}@anchor{3ef}@anchor{gnat_rm/compatibility_and_porting_guide id16}@anchor{3f2} +@section Representation Clauses + + +The Ada 83 reference manual was quite vague in describing both the minimal +required implementation of representation clauses, and also their precise +effects. Ada 95 (and thus also Ada 2005) are much more explicit, but the +minimal set of capabilities required is still quite limited. + +GNAT implements the full required set of capabilities in +Ada 95 and Ada 2005, but also goes much further, and in particular +an effort has been made to be compatible with existing Ada 83 usage to the +greatest extent possible. + +A few cases exist in which Ada 83 compiler behavior is incompatible with +the requirements in Ada 95 (and thus also Ada 2005). These are instances of +intentional or accidental dependence on specific implementation dependent +characteristics of these Ada 83 compilers. The following is a list of +the cases most likely to arise in existing Ada 83 code. + + +@itemize * + +@item +@emph{Implicit Packing} + +Some Ada 83 compilers allowed a Size specification to cause implicit +packing of an array or record. This could cause expensive implicit +conversions for change of representation in the presence of derived +types, and the Ada design intends to avoid this possibility. +Subsequent AI's were issued to make it clear that such implicit +change of representation in response to a Size clause is inadvisable, +and this recommendation is represented explicitly in the Ada 95 (and Ada 2005) +Reference Manuals as implementation advice that is followed by GNAT. +The problem will show up as an error +message rejecting the size clause. The fix is simply to provide +the explicit pragma @cite{Pack}, or for more fine tuned control, provide +a Component_Size clause. + +@item +@emph{Meaning of Size Attribute} + +The Size attribute in Ada 95 (and Ada 2005) for discrete types is defined as +the minimal number of bits required to hold values of the type. For example, +on a 32-bit machine, the size of @cite{Natural} will typically be 31 and not +32 (since no sign bit is required). Some Ada 83 compilers gave 31, and +some 32 in this situation. This problem will usually show up as a compile +time error, but not always. It is a good idea to check all uses of the +'Size attribute when porting Ada 83 code. The GNAT specific attribute +Object_Size can provide a useful way of duplicating the behavior of +some Ada 83 compiler systems. + +@item +@emph{Size of Access Types} + +A common assumption in Ada 83 code is that an access type is in fact a pointer, +and that therefore it will be the same size as a System.Address value. This +assumption is true for GNAT in most cases with one exception. For the case of +a pointer to an unconstrained array type (where the bounds may vary from one +value of the access type to another), the default is to use a 'fat pointer', +which is represented as two separate pointers, one to the bounds, and one to +the array. This representation has a number of advantages, including improved +efficiency. However, it may cause some difficulties in porting existing Ada 83 +code which makes the assumption that, for example, pointers fit in 32 bits on +a machine with 32-bit addressing. + +To get around this problem, GNAT also permits the use of 'thin pointers' for +access types in this case (where the designated type is an unconstrained array +type). These thin pointers are indeed the same size as a System.Address value. +To specify a thin pointer, use a size clause for the type, for example: + +@example +type X is access all String; +for X'Size use Standard'Address_Size; +@end example + +which will cause the type X to be represented using a single pointer. +When using this representation, the bounds are right behind the array. +This representation is slightly less efficient, and does not allow quite +such flexibility in the use of foreign pointers or in using the +Unrestricted_Access attribute to create pointers to non-aliased objects. +But for any standard portable use of the access type it will work in +a functionally correct manner and allow porting of existing code. +Note that another way of forcing a thin pointer representation +is to use a component size clause for the element size in an array, +or a record representation clause for an access field in a record. + +See the documentation of Unrestricted_Access in the GNAT RM for a +full discussion of possible problems using this attribute in conjunction +with thin pointers. +@end itemize + +@node Compatibility with HP Ada 83,,Representation Clauses,Compatibility and Porting Guide +@anchor{gnat_rm/compatibility_and_porting_guide compatibility-with-hp-ada-83}@anchor{3f3}@anchor{gnat_rm/compatibility_and_porting_guide id17}@anchor{3f4} +@section Compatibility with HP Ada 83 + + +All the HP Ada 83 pragmas and attributes are recognized, although only a subset +of them can sensibly be implemented. The description of pragmas in +@ref{7,,Implementation Defined Pragmas} indicates whether or not they are +applicable to GNAT. + + +@itemize * + +@item +@emph{Default floating-point representation} + +In GNAT, the default floating-point format is IEEE, whereas in HP Ada 83, +it is VMS format. + +@item +@emph{System} + +the package System in GNAT exactly corresponds to the definition in the +Ada 95 reference manual, which means that it excludes many of the +HP Ada 83 extensions. However, a separate package Aux_DEC is provided +that contains the additional definitions, and a special pragma, +Extend_System allows this package to be treated transparently as an +extension of package System. +@end itemize + +@node GNU Free Documentation License,Index,Compatibility and Porting Guide,Top +@anchor{share/gnu_free_documentation_license gnu-fdl}@anchor{1}@anchor{share/gnu_free_documentation_license doc}@anchor{3f5}@anchor{share/gnu_free_documentation_license gnu-free-documentation-license}@anchor{3f6} +@chapter GNU Free Documentation License + + +Version 1.3, 3 November 2008 + +Copyright 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc +@indicateurl{http://fsf.org/} + +Everyone is permitted to copy and distribute verbatim copies of this +license document, but changing it is not allowed. + +@strong{Preamble} + +The purpose of this License is to make a manual, textbook, or other +functional and useful document "free" in the sense of freedom: to +assure everyone the effective freedom to copy and redistribute it, +with or without modifying it, either commercially or noncommercially. +Secondarily, this License preserves for the author and publisher a way +to get credit for their work, while not being considered responsible +for modifications made by others. + +This License is a kind of "copyleft", which means that derivative +works of the document must themselves be free in the same sense. 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MODIFICATIONS} + +You may copy and distribute a Modified Version of the Document under +the conditions of sections 2 and 3 above, provided that you release +the Modified Version under precisely this License, with the Modified +Version filling the role of the Document, thus licensing distribution +and modification of the Modified Version to whoever possesses a copy +of it. In addition, you must do these things in the Modified Version: + + +@enumerate A + +@item +Use in the Title Page (and on the covers, if any) a title distinct +from that of the Document, and from those of previous versions +(which should, if there were any, be listed in the History section +of the Document). You may use the same title as a previous version +if the original publisher of that version gives permission. + +@item +List on the Title Page, as authors, one or more persons or entities +responsible for authorship of the modifications in the Modified +Version, together with at least five of the principal authors of the +Document (all of its principal authors, if it has fewer than five), +unless they release you from this requirement. + +@item +State on the Title page the name of the publisher of the +Modified Version, as the publisher. + +@item +Preserve all the copyright notices of the Document. + +@item +Add an appropriate copyright notice for your modifications +adjacent to the other copyright notices. + +@item +Include, immediately after the copyright notices, a license notice +giving the public permission to use the Modified Version under the +terms of this License, in the form shown in the Addendum below. + +@item +Preserve in that license notice the full lists of Invariant Sections +and required Cover Texts given in the Document's license notice. + +@item +Include an unaltered copy of this License. + +@item +Preserve the section Entitled "History", Preserve its Title, and add +to it an item stating at least the title, year, new authors, and +publisher of the Modified Version as given on the Title Page. If +there is no section Entitled "History" in the Document, create one +stating the title, year, authors, and publisher of the Document as +given on its Title Page, then add an item describing the Modified +Version as stated in the previous sentence. + +@item +Preserve the network location, if any, given in the Document for +public access to a Transparent copy of the Document, and likewise +the network locations given in the Document for previous versions +it was based on. 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Such a section +may not be included in the Modified Version. + +@item +Do not retitle any existing section to be Entitled "Endorsements" +or to conflict in title with any Invariant Section. + +@item +Preserve any Warranty Disclaimers. +@end enumerate + +If the Modified Version includes new front-matter sections or +appendices that qualify as Secondary Sections and contain no material +copied from the Document, you may at your option designate some or all +of these sections as invariant. To do this, add their titles to the +list of Invariant Sections in the Modified Version's license notice. +These titles must be distinct from any other section titles. + +You may add a section Entitled "Endorsements", provided it contains +nothing but endorsements of your Modified Version by various +parties---for example, statements of peer review or that the text has +been approved by an organization as the authoritative definition of a +standard. + +You may add a passage of up to five words as a Front-Cover Text, and a +passage of up to 25 words as a Back-Cover Text, to the end of the list +of Cover Texts in the Modified Version. Only one passage of +Front-Cover Text and one of Back-Cover Text may be added by (or +through arrangements made by) any one entity. If the Document already +includes a cover text for the same cover, previously added by you or +by arrangement made by the same entity you are acting on behalf of, +you may not add another; but you may replace the old one, on explicit +permission from the previous publisher that added the old one. + +The author(s) and publisher(s) of the Document do not by this License +give permission to use their names for publicity for or to assert or +imply endorsement of any Modified Version. + +@strong{5. COMBINING DOCUMENTS} + +You may combine the Document with other documents released under this +License, under the terms defined in section 4 above for modified +versions, provided that you include in the combination all of the +Invariant Sections of all of the original documents, unmodified, and +list them all as Invariant Sections of your combined work in its +license notice, and that you preserve all their Warranty Disclaimers. + +The combined work need only contain one copy of this License, and +multiple identical Invariant Sections may be replaced with a single +copy. If there are multiple Invariant Sections with the same name but +different contents, make the title of each such section unique by +adding at the end of it, in parentheses, the name of the original +author or publisher of that section if known, or else a unique number. +Make the same adjustment to the section titles in the list of +Invariant Sections in the license notice of the combined work. + +In the combination, you must combine any sections Entitled "History" +in the various original documents, forming one section Entitled +"History"; likewise combine any sections Entitled "Acknowledgements", +and any sections Entitled "Dedications". You must delete all sections +Entitled "Endorsements". + +@strong{6. COLLECTIONS OF DOCUMENTS} + +You may make a collection consisting of the Document and other documents +released under this License, and replace the individual copies of this +License in the various documents with a single copy that is included in +the collection, provided that you follow the rules of this License for +verbatim copying of each of the documents in all other respects. + +You may extract a single document from such a collection, and distribute +it individually under this License, provided you insert a copy of this +License into the extracted document, and follow this License in all +other respects regarding verbatim copying of that document. + +@strong{7. 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TRANSLATION} + +Translation is considered a kind of modification, so you may +distribute translations of the Document under the terms of section 4. +Replacing Invariant Sections with translations requires special +permission from their copyright holders, but you may include +translations of some or all Invariant Sections in addition to the +original versions of these Invariant Sections. You may include a +translation of this License, and all the license notices in the +Document, and any Warranty Disclaimers, provided that you also include +the original English version of this License and the original versions +of those notices and disclaimers. In case of a disagreement between +the translation and the original version of this License or a notice +or disclaimer, the original version will prevail. + +If a section in the Document is Entitled "Acknowledgements", +"Dedications", or "History", the requirement (section 4) to Preserve +its Title (section 1) will typically require changing the actual +title. + +@strong{9. TERMINATION} + +You may not copy, modify, sublicense, or distribute the Document +except as expressly provided under this License. Any attempt +otherwise to copy, modify, sublicense, or distribute it is void, and +will automatically terminate your rights under this License. + +However, if you cease all violation of this License, then your license +from a particular copyright holder is reinstated (a) provisionally, +unless and until the copyright holder explicitly and finally +terminates your license, and (b) permanently, if the copyright holder +fails to notify you of the violation by some reasonable means prior to +60 days after the cessation. + +Moreover, your license from a particular copyright holder is +reinstated permanently if the copyright holder notifies you of the +violation by some reasonable means, this is the first time you have +received notice of violation of this License (for any work) from that +copyright holder, and you cure the violation prior to 30 days after +your receipt of the notice. + +Termination of your rights under this section does not terminate the +licenses of parties who have received copies or rights from you under +this License. If your rights have been terminated and not permanently +reinstated, receipt of a copy of some or all of the same material does +not give you any rights to use it. + +@strong{10. FUTURE REVISIONS OF THIS LICENSE} + +The Free Software Foundation may publish new, revised versions +of the GNU Free Documentation License from time to time. Such new +versions will be similar in spirit to the present version, but may +differ in detail to address new problems or concerns. See +@indicateurl{http://www.gnu.org/copyleft/}. + +Each version of the License is given a distinguishing version number. +If the Document specifies that a particular numbered version of this +License "or any later version" applies to it, you have the option of +following the terms and conditions either of that specified version or +of any later version that has been published (not as a draft) by the +Free Software Foundation. If the Document does not specify a version +number of this License, you may choose any version ever published (not +as a draft) by the Free Software Foundation. If the Document +specifies that a proxy can decide which future versions of this +License can be used, that proxy's public statement of acceptance of a +version permanently authorizes you to choose that version for the +Document. + +@strong{11. RELICENSING} + +"Massive Multiauthor Collaboration Site" (or "MMC Site") means any +World Wide Web server that publishes copyrightable works and also +provides prominent facilities for anybody to edit those works. A +public wiki that anybody can edit is an example of such a server. A +"Massive Multiauthor Collaboration" (or "MMC") contained in the +site means any set of copyrightable works thus published on the MMC +site. + +"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0 +license published by Creative Commons Corporation, a not-for-profit +corporation with a principal place of business in San Francisco, +California, as well as future copyleft versions of that license +published by that same organization. + +"Incorporate" means to publish or republish a Document, in whole or +in part, as part of another Document. + +An MMC is "eligible for relicensing" if it is licensed under this +License, and if all works that were first published under this License +somewhere other than this MMC, and subsequently incorporated in whole +or in part into the MMC, (1) had no cover texts or invariant sections, +and (2) were thus incorporated prior to November 1, 2008. + +The operator of an MMC Site may republish an MMC contained in the site +under CC-BY-SA on the same site at any time before August 1, 2009, +provided the MMC is eligible for relicensing. + +@strong{ADDENDUM: How to use this License for your documents} + +To use this License in a document you have written, include a copy of +the License in the document and put the following copyright and +license notices just after the title page: + +@quotation + +Copyright © YEAR YOUR NAME. +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 +or any later version published by the Free Software Foundation; +with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. +A copy of the license is included in the section entitled "GNU +Free Documentation License". +@end quotation + +If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, +replace the "with ... Texts." line with this: + +@quotation + +with the Invariant Sections being LIST THEIR TITLES, with the +Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST. +@end quotation + +If you have Invariant Sections without Cover Texts, or some other +combination of the three, merge those two alternatives to suit the +situation. + +If your document contains nontrivial examples of program code, we +recommend releasing these examples in parallel under your choice of +free software license, such as the GNU General Public License, +to permit their use in free software. + +@node Index,,GNU Free Documentation License,Top @unnumbered Index -@printindex cp -@contents +@printindex ge + +@c %**end of body @bye |