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| -rw-r--r-- | gcc/ada/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/ada/gnat_rm.texi | 3169 |
2 files changed, 1688 insertions, 1486 deletions
diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog index 4512729..5f2d424 100644 --- a/gcc/ada/ChangeLog +++ b/gcc/ada/ChangeLog @@ -1,3 +1,8 @@ +2002-03-23 Florian Weimer <fw@deneb.enyo.de> + + * gnat_rm.texi: Sync with ACT version. + (From Ben Brosgol <brosgol@gnat.com>) + 2002-03-20 Neil Booth <neil@daikokuya.demon.co.uk> * misc.c (LANG_HOOKS_DECL_PRINTABLE_NAME): Redefine. diff --git a/gcc/ada/gnat_rm.texi b/gcc/ada/gnat_rm.texi index 2fc3aa6..78ac266 100644 --- a/gcc/ada/gnat_rm.texi +++ b/gcc/ada/gnat_rm.texi @@ -9,19 +9,10 @@ @c o @c G N A T _ RM o @c o +@c $Revision: 1.254 $ @c o -@c Copyright (C) 1992-2001 Ada Core Technologies, Inc. o +@c Copyright (C) 1995-2002 Free Software Foundation o @c o -@c GNAT is free software; you can redistribute it and/or modify it under o -@c terms of the GNU General Public License as published by the Free Soft- o -@c ware Foundation; either version 2, or (at your option) any later ver- o -@c sion. GNAT is distributed in the hope that it will be useful, but WITH- o -@c OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY o -@c or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License o -@c for more details. You should have received a copy of the GNU General o -@c Public License distributed with GNAT; see file COPYING. If not, write o -@c to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, o -@c MA 02111-1307, USA. o @c o @c GNAT is maintained by Ada Core Technologies Inc (http://www.gnat.com). o @c o @@ -32,20 +23,28 @@ @setchapternewpage odd @syncodeindex fn cp +@dircategory GNU Ada tools +@direntry +* GNAT Reference Manual: (gnat_rm). Reference Manual for GNU Ada tools. +@end direntry @titlepage @title GNAT Reference Manual @subtitle GNAT, The GNU Ada 95 Compiler -@subtitle Version 3.15w -@subtitle Date: $Date: 2001/12/18 00:03:37 $ +@ifset vxworks +@title Version 3.16w +@end ifset +@ifclear vxworks +@subtitle Version 3.16w +@end ifclear @author Ada Core Technologies, Inc. @page @vskip 0pt plus 1filll -Copyright @copyright{} 1995-2001, Ada Core Technologies +Copyright @copyright{} 1995-2001, Free Software Foundation Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 @@ -55,20 +54,6 @@ 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''. -Silicon Graphics and IRIS are registered trademarks -and IRIX is a trademark of Silicon Graphics, Inc. - -IBM PC is a trademark of International -Business Machines Corporation. - -UNIX is a registered trademark of AT&T -Bell Laboratories. -DIGITAL - -VADS is a registered trademark of Rational Software Inc. - -The following are trademarks of Digital Equipment Corporation: -DEC, DEC Ada, DECthreads, Digital, OpenVMS, and VAX@. @end titlepage @ifinfo @@ -80,38 +65,26 @@ GNAT Reference Manual GNAT, The GNU Ada 95 Compiler -Version 3.14a - -Date: $Date: 2001/12/18 00:03:37 $ +@ifset vxworks +Version 3.16w +@end ifset +@ifclear vxworks +Version 3.16w +@end ifclear Ada Core Technologies, Inc. -Copyright @copyright{} 1995-2001, Ada Core Technologies +Copyright @copyright{} 1995-2001, Free Software Foundation Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; -with the Invariant Sections being "GNU Free Documentation License", 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". - - -Silicon Graphics and IRIS are registered trademarks -and IRIX is a trademark of Silicon Graphics, Inc. - -IBM PC is a trademark of International -Business Machines Corporation. - -UNIX is a registered trademark of AT&T -Bell Laboratories. -DIGITAL - -VADS is a registered trademark of Rational Software Inc. +with the Invariant Sections being ``GNU Free Documentation License'', 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''. -The following are trademarks of Digital Equipment Corporation: -DEC, DEC Ada, DECthreads, Digital, OpenVMS, and VAX@. @menu * About This Guide:: @@ -156,7 +129,9 @@ The Implementation of Standard I/O 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.Command_Line.Remove (a-colire.ads):: * Ada.Direct_IO.C_Streams (a-diocst.ads):: * Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads):: @@ -191,6 +166,7 @@ The GNAT Library * GNAT.IO (g-io.ads):: * GNAT.IO_Aux (g-io_aux.ads):: * GNAT.Lock_Files (g-locfil.ads):: +* GNAT.MD5 (g-md5.ads):: * GNAT.Most_Recent_Exception (g-moreex.ads):: * GNAT.OS_Lib (g-os_lib.ads):: * GNAT.Regexp (g-regexp.ads):: @@ -218,6 +194,7 @@ The GNAT Library * Interfaces.Os2lib.Threads (i-os2thr.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.Partition_Interface (s-parint.ads):: @@ -260,15 +237,15 @@ GNAT Implementation of Tasking @noindent This manual contains useful information in writing programs using the -GNAT compiler. It includes information on implementation dependent +GNAT compiler. It includes information on implementation dependent characteristics of GNAT, including all the information required by Annex M of the standard. Ada 95 is designed to be highly portable,and guarantees that, for most programs, Ada 95 compilers behave in exactly the same manner on -different machines. However, since Ada 95 is designed to be used in a +different machines. However, since Ada 95 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. +dependent features to Functbe used in interfacing to the external world. @c Maybe put the following in platform-specific section @ignore @@ -370,13 +347,13 @@ in this guide: and @code{classes}. @item -@samp{Option flags} +@code{Option flags} @item -@file{File Names}, @file{button names}, and @file{field names}. +@file{File Names}, @samp{button names}, and @samp{field names}. @item -@var{Variables}. +@code{Variables}. @item @emph{Emphasis}. @@ -393,14 +370,14 @@ and then shown this way. @noindent Commands that are entered by the user are preceded in this manual by the -characters "$ " (dollar sign followed by space). If your system uses this +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 $ replaced by whatever prompt character you are using. +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 @unnumberedsec Related Information -See the following documents for further information on GNAT +See the following documents for further information on GNAT: @itemize @bullet @item @@ -413,7 +390,7 @@ material for the Ada 95 programming language. @item @cite{Ada 95 Annotated Reference Manual}, which is an annotated version -of the standard reference manual cited above. The annotations describe +of the standard reference manual cited above. The annotations describe detailed aspects of the design decision, and in particular contain useful sections on Ada 83 compatibility. @@ -434,19 +411,19 @@ compiler system. @noindent Ada 95 defines a set of pragmas that can be used to supply additional -information to the compiler. These language defined pragmas are +information to the compiler. These language defined pragmas are implemented in GNAT and work as described in the Ada 95 Reference Manual. In addition, Ada 95 allows implementations to define additional pragmas -whose meaning is defined by the implementation. GNAT provides a number +whose meaning is defined by the implementation. GNAT provides a number of these implementation-dependent pragmas which can be used to extend -and enhance the functionality of the compiler. This section of the GNAT +and enhance the functionality of the compiler. This section of the GNAT Reference Manual describes these additional pragmas. Note that any program using these pragmas may not be portable to other compilers (although GNAT implements this set of pragmas on all -platforms). Therefore if portability to other compilers is an important +platforms). Therefore if portability to other compilers is an important consideration, the use of these pragmas should be minimized. @table @code @@ -463,7 +440,7 @@ pragma Abort_Defer; @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 @code{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). @@ -480,15 +457,15 @@ pragma Ada_83; @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 +switches. In Ada 83 mode, GNAT attempts to be as compatible with the syntax and semantics of Ada 83, as defined in the original Ada -83 Reference Manual as possible. In particular, the new Ada 95 +83 Reference Manual as possible. In particular, the new Ada 95 keywords are not recognized, optional package bodies are allowed, and generics may name types with unknown discriminants without using -the (<>) notation. In addition, some but not all of the additional +the @code{(<>)} 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 +Ada 83 mode is intended for two purposes. Firstly, it allows existing legacy Ada 83 code to be compiled and adapted to GNAT with less effort. Secondly, it aids in keeping code backwards compatible with Ada 83. However, there is no guarantee that code that is processed correctly @@ -510,7 +487,7 @@ 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} packages and their children, so you need not specify it in these -contexts. This pragma is useful when writing a reusable component that +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. @@ -526,17 +503,17 @@ ARG ::= NAME | EXPRESSION @end smallexample @noindent -This pragma is used to annotate programs. @var{identifier} identifies -the type of annotation. GNAT verifies this is an identifier, but does -not otherwise analyze it. The @var{arg} argument +This pragma is used to annotate programs. @var{identifier} identifies +the type of annotation. GNAT verifies this is an identifier, but does +not otherwise analyze it. The @var{arg} argument can be either a string literal or an -expression. String literals are assumed to be of type -@code{Standard.String}. Names of entities are simply analyzed as entity -names. All other expressions are analyzed as expressions, and must be +expression. String literals are assumed to be of type +@code{Standard.String}. Names of entities are simply analyzed as entity +names. All other expressions are analyzed as expressions, and must be unambiguous. The analyzed pragma is retained in the tree, but not otherwise processed -by any part of the GNAT compiler. This pragma is intended for use by +by any part of the GNAT compiler. This pragma is intended for use by external tools, including ASIS@. @findex Assert @@ -552,7 +529,7 @@ pragma Assert ( @noindent The effect of this pragma depends on whether the corresponding command -line switch is set to activate assertions. The pragma expands into code +line switch is set to activate assertions. The pragma expands into code equivalent to the following: @smallexample @@ -566,15 +543,15 @@ end if; @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 +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 +and @var{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 -... +@dots{} if J > 3 then pragma Assert (K > 3, "Bad value for K"); null; @@ -582,24 +559,24 @@ end if; @end smallexample @noindent -Note that, as with the if statement to which it is equivalent, the -type of the expression is either Standard.Boolean, or any type derived +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 from this standard type. If assertions are disabled (switch @code{-gnata} not used), then there is no effect (and in particular, any side effects from the expression -are suppressed). More precisely it is not quite true that the pragma +are suppressed). More precisely it is not quite true that the pragma has no effect, since the expression is analyzed, and may cause types to be frozen if they are mentioned here for the first time. If assertions are enabled, then the given expression is tested, and if -it is @code{False} then System.Assertions.Raise_Assert_Failure is called -which results in the raising of Assert_Failure with the given message. +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. If the boolean expression has side effects, these side effects will turn on and off with the setting of the assertions mode, resulting in -assertions that have an effect on the program. You should generally -avoid side effects in the expression arguments of this pragma. However, +assertions that have an effect on the program. You should generally +avoid side effects in the expression arguments of this pragma. 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. @@ -615,15 +592,15 @@ pragma AST_Entry (entry_IDENTIFIER); @end smallexample @noindent -This pragma is implemented only in the OpenVMS implementation of GNAT@. The +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 +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 +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 +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. @cindex Passing by copy @@ -640,7 +617,7 @@ pragma C_Pass_By_Copy @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 @code{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: @@ -674,10 +651,10 @@ pragma Comment (static_string_EXPRESSION); @end smallexample @noindent -This is almost identical in effect to pragma Ident. It allows the +This is almost identical in effect to pragma @code{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 Comment, unlike Ident, has no limit on the +executable file if the operating system permits such usage. The +difference is that @code{Comment}, unlike @code{Ident}, has no limit on the length of the string argument, and no limitations on placement of the pragma (it can be placed anywhere in the main source unit). @@ -704,10 +681,10 @@ in Fortran. The single object @var{local_name} is assigned to the area designated by the @var{External} argument. You may define a record to correspond to a series -of fields. The @var{size} argument +of fields. The @var{size} argument is syntax checked in GNAT, but otherwise ignored. -@code{Common_Object} is not supported on all platforms. If no +@code{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. @@ -724,11 +701,11 @@ pragma Complex_Representation @noindent The @var{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 +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 +this record, which may be more efficient. Note that this may result in the code for this type not conforming to standard ABI (application -binary interface) requirements for the handling of record types. For +binary interface) requirements for the handling of record types. For 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. @@ -760,16 +737,16 @@ The meaning of the @var{Form} argument is as follows: @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, +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 +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@. @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 +bytes. Components that are larger than 4 bytes are placed on the next 4-byte boundary. @findex Storage_Unit @@ -782,17 +759,17 @@ aligned on boundaries determined by the value of the constant @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, +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 alignment). @end table If the @code{Name} parameter is present, @var{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 +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} pragma to be ignored. The use of @code{Component_Alignment} together with a record representation clause is only effective for fields not specified by the representation clause. @@ -801,13 +778,47 @@ 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 are declared within this declarative part, or within any nested scope -within this declarative part. In either case it specifies the alignment +within this declarative part. In either case it specifies the alignment 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 clause), the GNAT uses the default alignment as described previously. + +@findex Convention_Identifier +@cindex Conventions, synonyms +@item pragma Convention_Identifier +@noindent +Syntax: + +@smallexample +pragma Convention_Identifier ( + [Name =>] IDENTIFIER, + [Convention =>] convention_IDENTIFIER); +@end smallexample + +@noindent +This pragma provides a mechanism for supplying synonyms for existing +convention identifiers. The @code{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} +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 +pragma Convention_Indentifier (Fortran77, Fortran); +@end smallexample + +@noindent +would allow the use of the convention identifier @code{Fortran77} in +subsequent code, avoiding the need to modify the sources. As another +example, you could use this to parametrize 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 +would be used system-wide. @findex CPP_Class @cindex Interfacing with C++ @@ -821,7 +832,7 @@ pragma CPP_Class ([Entity =>] LOCAL_NAME); @noindent The argument denotes an entity in the current declarative region -that is declared as a tagged or untagged record type. It indicates that +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. @@ -832,13 +843,12 @@ for dispatching. Types for which @code{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 +as subprograms as required). Initialization is allowed only by constructor functions (see pragma @code{CPP_Constructor}). Pragma @code{CPP_Class} is intended primarily for automatic generation -using an automatic binding generator tool. Ada Core Technologies does -not currently supply such a -tool; See @ref{Interfacing to C++} for more details. +using an automatic binding generator tool. +See @ref{Interfacing to C++} for related information. @cindex Interfacing with C++ @findex CPP_Constructor @@ -852,10 +862,10 @@ pragma CPP_Constructor ([Entity =>] LOCAL_NAME); @noindent This pragma identifies an imported function (imported in the usual way -with pragma Import) as corresponding to a C++ -constructor. The argument is a name that must have been -previously mentioned in a pragma -Import with @var{Convention CPP}, and must be of one of the following +with pragma @code{Import}) as corresponding to a C++ +constructor. The argument is a name that must have been +previously mentioned in a pragma @code{Import} +with @code{Convention} = @code{CPP}, and must be of one of the following forms: @itemize @bullet @@ -870,7 +880,7 @@ forms: where @var{T} is a tagged type to which the pragma @code{CPP_Class} applies. The first form is the default constructor, used when an object of type -@var{T} is created on the Ada side with no explicit constructor. Other +@var{T} is created on the Ada side with no explicit constructor. Other constructors (including the copy constructor, which is simply a special case of the second form in which the one and only argument is of type @var{T}), can only appear in two contexts: @@ -885,7 +895,7 @@ In an extension aggregate for an object of a type derived from @var{T}. Although the constructor is described as a function that returns a value on the Ada side, it is typically a procedure with an extra implicit argument (the object being initialized) at the implementation -level. GNAT issues the appropriate call, whatever it is, to get the +level. GNAT issues the appropriate call, whatever it is, to get the object properly initialized. In the case of derived objects, you may use one of two possible forms @@ -898,19 +908,18 @@ for declaring and creating an object: In the first case the default constructor is called and extension fields if any are initialized according to the default initialization -expressions in the Ada declaration. In the second case, the given +expressions in the Ada declaration. In the second case, the given constructor is called and the extension aggregate indicates the explicit values of the extension fields. If no constructors are imported, it is impossible to create any objects -on the Ada side. If no default constructor is imported, only the +on the Ada side. If no default constructor is imported, only the initialization forms using an explicit call to a constructor are permitted. Pragma @code{CPP_Constructor} is intended primarily for automatic generation -using an automatic binding generator tool. Ada Core Technologies does -not currently supply such a -tool; See @ref{Interfacing to C++} for more details. +using an automatic binding generator tool. +See @ref{Interfacing to C++} for more related information. @cindex Interfacing to C++ @findex CPP_Virtual @@ -926,12 +935,12 @@ pragma CPP_Virtual @end smallexample This pragma serves the same function as pragma @code{Import} in that -case of a virtual function imported from C++. The @var{Entity} argument +case of a virtual function imported from C++. The @var{Entity} argument must be a primitive subprogram of a tagged type to which pragma @code{CPP_Class} -applies. The @var{Vtable_Ptr} argument specifies +applies. The @var{Vtable_Ptr} argument specifies the Vtable_Ptr component which contains the -entry for this virtual function. The @var{Position} argument +entry for this virtual function. The @var{Position} argument is the sequential number counting virtual functions for this Vtable starting at 1. @@ -945,9 +954,8 @@ virtual function, since it is always accessed indirectly via the appropriate Vtable entry. Pragma @code{CPP_Virtual} is intended primarily for automatic generation -using an automatic binding generator tool. Ada Core Technologies does -not currently supply such a -tool; See @ref{Interfacing to C++} for more details. +using an automatic binding generator tool. +See @ref{Interfacing to C++} for related information. @cindex Interfacing with C++ @findex CPP_Vtable @@ -968,7 +976,7 @@ this pragma can be specified for each component of type @code{CPP.Interfaces.Vtable_Ptr}. @var{Entity} is the tagged type, @var{Vtable_Ptr} is the record field of type @code{Vtable_Ptr}, and @var{Entry_Count} is -the number of virtual functions on the C++ side. Not all of these +the number of virtual functions on the C++ side. Not all of these functions need to be imported on the Ada side. You may omit the @code{CPP_Vtable} pragma if there is only one @@ -977,9 +985,8 @@ imported on the Ada side (the default value for the entry count in this case is simply the total number of virtual functions). Pragma @code{CPP_Vtable} is intended primarily for automatic generation -using an automatic binding generator tool. Ada Core Technologies does -not currently supply such a -tool; See @ref{Interfacing to C++} for more details. +using an automatic binding generator tool. +See @ref{Interfacing to C++} for related information. @findex Debug @item pragma Debug @@ -987,13 +994,21 @@ tool; See @ref{Interfacing to C++} for more details. Syntax: @smallexample -pragma Debug (PROCEDURE_CALL_STATEMENT); +pragma Debug (PROCEDURE_CALL_WITHOUT_SEMICOLON); + +PROCEDURE_CALL_WITHOUT_SEMICOLON ::= + PROCEDURE_NAME +| PROCEDURE_PREFIX ACTUAL_PARAMETER_PART @end smallexample @noindent +The argument has the syntactic form of an expression, meeting the +syntactic requirements for pragmas. + If assertions are not enabled on the command line, this pragma has no -effect. If asserts are enabled, the semantics of the pragma is exactly -equivalent to the procedure call. Pragmas are permitted in sequences of +effect. If asserts 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 intersperse calls to debug procedures in the middle of declarations. @@ -1010,14 +1025,14 @@ pragma Elaboration_Checks (RM | Static); @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 RM, then the dynamic elaboration +pragma. If the parameter is RM, then the dynamic elaboration model described in the Ada Reference Manual is used, as though the @code{-gnatE} switch had been specified on the command -line. If the parameter is 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 section "Elaboration Order -Handling in GNAT" in the GNAT Users Guide. +line. If the parameter is 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 section ``Elaboration Order +Handling in GNAT'' in the @cite{GNAT User's Guide}. @cindex Elimination of unused subprograms @findex Eliminate @@ -1032,12 +1047,13 @@ pragma Eliminate ( pragma Eliminate ( [Unit_Name =>] IDENTIFIER | - SELECTED_COMPONENT + SELECTED_COMPONENT, [Entity =>] IDENTIFIER | SELECTED_COMPONENT | - STRING_LITERAL] - [,[Parameter_Types =>] PARAMETER_TYPES] - [,[Result_Type =>] result_SUBTYPE_NAME]]); + STRING_LITERAL + [,[Parameter_Types =>] PARAMETER_TYPES] + [,[Result_Type =>] result_SUBTYPE_NAME] + [,[Homonym_Number =>] INTEGER_LITERAL]); PARAMETER_TYPES ::= (SUBTYPE_NAME @{, SUBTYPE_NAME@}) SUBTYPE_NAME ::= STRING_LITERAL @@ -1045,7 +1061,7 @@ SUBTYPE_NAME ::= STRING_LITERAL @noindent This pragma indicates that the given entity is not used outside the -compilation unit it is defined in. The entity may be either a subprogram +compilation unit it is defined in. The entity may be either a subprogram or a variable. If the entity to be eliminated is a library level subprogram, then @@ -1054,31 +1070,44 @@ In this form, the @code{Unit_Name} argument specifies the name of the library level unit to be eliminated. In all other cases, both @code{Unit_Name} and @code{Entity} arguments -are required. item is an entity of a library package, then the first +are required. item is an entity of a library package, then the first argument specifies the unit name, and the second argument specifies -the particular entity. If the second argument is in string form, it must +the particular entity. If the second argument is in string form, it must correspond to the internal manner in which GNAT stores entity names (see compilation unit Namet in the compiler sources for details). -The third and fourth parameters are optionally used to distinguish -between overloaded subprograms, in a manner similar to that used for + +The remaining parameters are optionally used to distinguish +between overloaded subprograms. There are two ways of doing this. + +Use @code{Parameter_Types} and @code{Result_Type} to specify the +profile of the subprogram to be eliminated in a manner similar to that +used for the extended @code{Import} and @code{Export} pragmas, except that the subtype names are always given as string literals, again corresponding to the internal manner in which GNAT stores entity names. +Alternatively, the @code{Homonym_Number} parameter is used to specify +which overloaded alternative is to be eliminated. A value of 1 indicates +the first subprogram (in lexical order), 2 indicates the second etc. + 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 outside the compilation unit it is defined in, causes a compile time or link time error. -The intention of pragma Eliminate is to allow a program to be compiled +The parameters of this pragma may be given in any order, as long as +the usual rules for use of named parameters and position parameters +are used. + +The intention of pragma @code{Eliminate} is to allow a program to be compiled in a system independent manner, with unused entities eliminated, without -the requirement of modifying the source text. Normally the required set -of Eliminate pragmas is constructed automatically using the gnatelim tool. +the requirement of modifying the source text. Normally the required set +of @code{Eliminate} pragmas is constructed automatically using the gnatelim tool. Elimination of unused entities local to a compilation unit is automatic, -without requiring the use of pragma Eliminate. +without requiring the use of pragma @code{Eliminate}. Note that the reason this pragma takes string literals where names might -be expected is that a pragma Eliminate can appear in a context where the +be expected is that a pragma @code{Eliminate} can appear in a context where the relevant names are not visible. @cindex OpenVMS @@ -1100,11 +1129,11 @@ EXTERNAL_SYMBOL ::= @end smallexample @noindent -This pragma is implemented only in the OpenVMS implementation of GNAT@. It +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 +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. @@ -1149,7 +1178,7 @@ CLASS_NAME ::= ubs | ubsb | uba | s | sb | a | nca 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, +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 @@ -1162,10 +1191,10 @@ Pragma @code{Export_Function} region as the function to which they apply. @var{internal_name} must uniquely designate the function to which the -pragma applies. If more than one function name exists of this name in +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 +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. @cindex OpenVMS @@ -1190,7 +1219,7 @@ EXTERNAL_SYMBOL ::= 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 @code{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@. @@ -1278,7 +1307,7 @@ CLASS_NAME ::= ubs | ubsb | uba | s | sb | a | nca 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 -with this parameter as the result of the function. GNAT provides for +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} parameters in interfacing to external functions (which are not permitted in Ada functions). @@ -1302,26 +1331,26 @@ pragma Extend_System ([Name =>] IDENTIFIER); @noindent This pragma is used to provide backwards compatibility with other -implementations that extend the facilities of package @code{System}. In +implementations that extend the facilities of package @code{System}. In GNAT, @code{System} contains only the definitions that are present in -the Ada 95 RM@. However, other implementations, notably the DEC Ada 83 +the Ada 95 RM@. However, other implementations, notably the DEC Ada 83 implementation, provide many extensions to package @code{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 -implementation, which provides the required additional definitions. You +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} -clause. In this case no special processing is required. +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 -provides greater compatibility with the existing code. Pragma +provides greater compatibility with the existing code. Pragma @code{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.@: @code{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 @@ -1330,10 +1359,10 @@ package @code{System}, but not found in package @code{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 construct your own extension unit following the above -definition. Note that such a package is a child of @code{System} -and thus is considered part of the implementation. To compile +definition. Note that such a package is a child of @code{System} +and thus is considered part of the implementation. To compile it you will have to use the appropriate switch for compiling -system units. See the GNAT User's Guide for details. +system units. See the GNAT User's Guide for details. @findex External @item pragma External @@ -1350,7 +1379,7 @@ pragma External ( @noindent This pragma is identical in syntax and semantics to pragma -@code{Export} as defined in the Ada Reference Manual. It is +@code{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. @@ -1371,11 +1400,11 @@ pragma External_Name_Casing ( @noindent This pragma provides control over the casing of external names associated -with Import and Export pragmas. There are two cases to consider: +with Import and Export pragmas. There are two cases to consider: @table @asis @item Implicit external names -Implicit external names are derived from identifiers. The most common case +Implicit external names are derived from identifiers. The most common case arises when a standard Ada 95 Import or Export pragma is used with only two arguments, as in: @@ -1386,12 +1415,12 @@ arguments, as in: @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 +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. +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, +control this treatment. If @code{Uppercase} is specified, then the name +will be forced to all uppercase letters. If @code{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 @@ -1399,7 +1428,7 @@ compatible Import and Export pragmas where an external name is explicitly specified using an identifier rather than a string. @item Explicit external names -Explicit external names are given as string literals. The most common case +Explicit external names are given as string literals. The most common case arises when a standard Ada 95 Import or Export pragma is used with three arguments, as in: @@ -1409,24 +1438,24 @@ pragma Import (C, C_Routine, "C_routine"); @noindent In this case, the string literal normally provides the exact casing required -for the external name. The second argument of pragma +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, -then the name will be forced to all lowercase letters. A specification of +will be forced to all uppercase letters. If @code{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 taken from the string provided. @end table @noindent -This pragma may appear anywhere that a pragma is valid. in particular, it -can be used as a configuration pragma in the @code{gnat.adc} file, in which +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 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 @code{OpenVMS} systems, where many -compilers convert all symbols to upper case by default. For interfacing to +It is 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 the pragma: @@ -1448,7 +1477,7 @@ pragma Finalize_Storage_Only (first_subtype_LOCAL_NAME); @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 +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. @@ -1469,9 +1498,9 @@ FLOAT_REP ::= VAX_Float | IEEE_Float This pragma is implemented only in the OpenVMS implementation of GNAT@. It allows control over the internal representation chosen for the predefined floating point types declared in the packages @code{Standard} and -@code{System}. For further details on this pragma, see the -DEC Ada Language Reference Manual, section 3.5.7a. Note that to use this -pragma, the standard runtime libraries must be recompiled. See the +@code{System}. For further details on this pragma, see the +DEC Ada Language Reference Manual, section 3.5.7a. Note that to use this +pragma, the standard runtime libraries must be recompiled. See the description of the @code{GNAT LIBRARY} command in the OpenVMS version of the GNAT Users Guide for details on the use of this command. @@ -1560,26 +1589,26 @@ CLASS_NAME ::= ubs | ubsb | uba | s | sb | a | nca @end smallexample This pragma is used in conjunction with a pragma @code{Import} to -specify additional information for an imported function. The pragma +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 declarative part as the function specification. The @var{Internal_Name} argument must uniquely designate the function to which the -pragma applies. If more than one function name exists of this name in +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 -designation. Subtype marks in these parameters must exactly match the +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. You may optionally use the @var{Mechanism} and @var{Result_Mechanism} parameters to specify passing mechanisms for the -parameters and result. If you specify a single mechanism name, it +parameters and result. If you specify a single mechanism name, it applies to all parameters. Otherwise you may specify a mechanism on a parameter by parameter basis using either positional or named -notation. If the mechanism is not specified, the default mechanism +notation. If the mechanism is not specified, the default mechanism is used. @cindex OpenVMS @@ -1591,7 +1620,7 @@ It specifies that the designated parameter and all following parameters are optional, meaning that they are not passed at the generated code level (this is distinct from the notion of optional parameters in Ada where the parameters are passed anyway with the designated optional -parameters). All optional parameters must be of mode @code{IN} and have +parameters). All optional parameters must be of mode @code{IN} and have default parameter values that are either known at compile time expressions, or uses of the @code{'Null_Parameter} attribute. @@ -1617,7 +1646,7 @@ 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, 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 +point of view). @var{size} is syntax checked, but otherwise ignored by GNAT@. @findex Import_Procedure @@ -1701,14 +1730,14 @@ CLASS_NAME ::= ubs | ubsb | uba | s | sb | a | nca 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 -with this parameter as the result of the function. The purpose of this +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} parameters in interfacing to external functions (which are not permitted in Ada functions). You may optionally use the @code{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 -basis using either positional or named notation. If the mechanism is not +basis using either positional or named notation. If the mechanism is not specified, the default mechanism is used. Note that it is important to use this pragma in conjunction with a separate @@ -1727,7 +1756,7 @@ pragma Initialize_Scalars; @noindent This pragma is similar to @code{Normalize_Scalars} conceptually but has -two important differences. First, there is no requirement for the pragma +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, without needing to recompile the run-time library. @@ -1735,26 +1764,26 @@ without needing to recompile the run-time library. In the case where some units are compiled with the pragma, and some without, then a declaration of a variable where the type is defined in package Standard or is locally declared will always be subject to initialization, -as will any declaration of a scalar variable. For composite variables, +as will any declaration of a scalar variable. For composite variables, whether the variable is initialized may also depend on whether the package in which the type of the variable is declared is compiled with the pragma. The other important difference is that there is control over the value used -for initializing scalar objects. At bind time, you can select whether to +for initializing scalar objects. At bind time, you can select whether to initialize with invalid values (like Normalize_Scalars), or with high or -low values, or with a specified bit pattern. See the users guide for binder +low values, or with a specified bit pattern. See the users guide for binder options for specifying these cases. This means that you can compile a program, and then without having to recompile the program, you can run it with different values being used for initializing otherwise uninitialized values, to test if your program -behavior depends on the choice. Of course the behavior should not change, +behavior depends on the choice. Of course the behavior should not change, and if it does, then most likely you have an erroneous reference to an uninitialized value. Note that pragma @code{Initialize_Scalars} is particularly useful in conjunction with the enhanced validity checking that is now provided -in @code{GNAT}, which checks for invalid values under more conditions. +in GNAT, which checks for invalid values under more conditions. Using this feature (see description of the @code{-gnatv} flag in the users guide) in conjunction with pragma @code{Initialize_Scalars} provides a powerful new tool to assist in the detection of problems @@ -1770,7 +1799,7 @@ pragma Inline_Always (NAME [, NAME]); @end smallexample @noindent -Similar to pragma @code{Inline} except that inlining is not subject to +Similar to pragma @code{Inline} except that inlining is not subject to the use of option @code{-gnatn} for inter-unit inlining. @findex Inline_Generic @@ -1784,7 +1813,7 @@ pragma Inline_Generic (generic_package_NAME) @noindent This is implemented for compatibility with DEC Ada 83 and is recognized, -but otherwise ignored, by GNAT@. All generic instantiations are inlined +but otherwise ignored, by GNAT@. All generic instantiations are inlined by default when using GNAT@. @findex Interface @@ -1802,8 +1831,8 @@ pragma Interface ( @noindent This pragma is identical in syntax and semantics to -the standard Ada 95 pragma @code{Import}. It is provided for compatibility -with Ada 83. The definition is upwards compatible both with pragma +the standard Ada 95 pragma @code{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 with some extended implementations of this pragma in certain Ada 83 implementations. @@ -1823,7 +1852,7 @@ pragma Interface_Name ( @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 +83 compilers that use the pragma for this purpose. You must provide at least one of @var{External_Name} or @var{Link_Name}. @findex License @@ -1838,7 +1867,7 @@ pragma License (Unrestricted | GPL | Modified_GPL | Restricted); @noindent This pragma is provided to allow automated checking for appropriate license -conditions with respect to the standard and modified GPL@. A pragma 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 the licensing conditions of a unit as follows: @@ -1857,14 +1886,14 @@ therefore cannot be @code{with}'ed by a restricted unit. 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@. This is the license used for the GNAT run-time which ensures +under the GPL@. This is the license used for the GNAT run-time which ensures that the run-time can be used freely in any program without GPL concerns. @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 @code{with} units which are licensed under the modified GPL (this is the whole point of the modified GPL). @@ -1872,34 +1901,34 @@ modified GPL). @noindent Normally a unit with no @code{License} pragma is considered to have an -unknown license, and no checking is done. However, standard GNAT headers +unknown license, and no checking is done. However, standard GNAT headers are recognized, and license information is derived from them as follows. @itemize @bullet -A GNAT license header starts with a line containing 78 hyphens. The following +A GNAT license header starts with a line containing 78 hyphens. The following comment text is searched for the appearence 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 +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 adapated from the Ada Semantic Interface" or -"This specification is derived from the Ada Reference Manual" is found +``This specification is adapated 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. @end itemize @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: +@code{with}'ed. For example, the program: @smallexample with Sem_Ch3; with GNAT.Sockets; procedure Secret_Stuff is -... +@dots{} end Secret_Stuff @end smallexample @@ -1908,12 +1937,12 @@ if compiled with pragma @code{License} (@code{Restricted}) in a @file{gnat.adc} file will generate the warning: @smallexample -1. with Sem_Ch3; +1. with Sem_Ch3; | >>> license of withed unit "Sem_Ch3" is incompatible -2. with GNAT.Sockets; -3. procedure Secret_Stuff is +2. with GNAT.Sockets; +3. procedure Secret_Stuff is @end smallexample @noindent Here we get a warning on @code{Sem_Ch3} since it is part of the GNAT @@ -1942,7 +1971,8 @@ pragma Link_With ("-labc -ldef"); @noindent results in passing the strings @code{-labc} and @code{-ldef} as two -separate arguments to the linker. +separate arguments to the linker. In addition pragma Link_With allows +multiple arguments, with the same effect as successive pragmas. @findex Linker_Alias @item pragma Linker_Alias @@ -1956,7 +1986,7 @@ pragma Linker_Alias ( @end smallexample @noindent -This pragma establishes a linker alias for the given named entity. For +This pragma establishes a linker alias for the given named entity. For further details on the exact effect, consult the GCC manual. @findex Linker_Section @@ -1985,9 +2015,9 @@ pragma No_Run_Time; @noindent This is a configuration pragma that makes sure the user code does not -use nor need anything from the GNAT run time. This is mostly useful in -context where code certification is required. Please consult the High -Integrity product documentation for additional information. +use nor need anything from the GNAT run time. This is mostly useful in +context where code certification is required. Please consult the +@cite{GNAT Pro High-Integrity Edition User's Guide} for additional information. @findex Normalize_Scalars @item pragma Normalize_Scalars @@ -1999,29 +2029,29 @@ pragma Normalize_Scalars; @end smallexample @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 +to be initialized. The initial values are implementation dependent and are as follows: @table @code @item Standard.Character @noindent Objects whose root type is Standard.Character are initialized to -Character'Last. This will be out of range of the subtype only if +Character'Last. This will be out of range of the subtype only if the subtype range excludes this value. @item Standard.Wide_Character @noindent Objects whose root type is Standard.Wide_Character are initialized to -Wide_Character'Last. This will be out of range of the subtype only if +Wide_Character'Last. This will be out of range of the subtype only if the subtype range excludes this value. @item Integer types @noindent Objects of an integer type are initialized to base_type'First, where -base_type is the base type of the object type. This will be out of range -of the subtype only if the subtype range excludes this value. For example, +base_type is the base type of the object type. This will be out of range +of the subtype only if the subtype range excludes this value. For example, if you declare the subtype: @smallexample @@ -2039,14 +2069,14 @@ This will be out of range of the subtype only if the subtype range excludes this value. @item Modular types -Objects of a modular type are initialized to typ'Last. This will be out +Objects of a modular type are initialized to typ'Last. This will be out of range of the subtype only if the subtype excludes this value. @item Enumeration types Objects of an enumeration type are initialized to all one-bits, i.e.@: to -the value 2 ** typ'Size - 1. This will be out of range of the enumeration +the value @code{2 ** typ'Size - 1}. This will be out of range of the enumeration subtype in all cases except where the subtype contains exactly -2**8, 2**16, or 2**32. +2**8, 2**16, or 2**32 elements. @end table @@ -2066,12 +2096,12 @@ FLOAT_FORMAT ::= D_Float | G_Float 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 .. 15. +@code{digits} specified in the range 7 through 15. For further details on this pragma, see the -DEC Ada Language Reference Manual, section 3.5.7b. Note that to use this -pragma, the standard runtime libraries must be recompiled. 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. See the description of the @code{GNAT LIBRARY} command in the OpenVMS version -of the GNAT Users Guide for details on the use of this command. +of the GNAT User's Guide for details on the use of this command. @findex Machine_Attribute @item pragma Machine_Attribute @dots{} @@ -2085,9 +2115,10 @@ pragma Machine_Attribute ( @end smallexample Machine dependent attributes can be specified for types and/or -declarations. Currently only subprogram entities are supported. This -pragma is semantically equivalent to @code{__attribute__(( -@var{string_expression}))} in GNU C, where @code{string_expression}> is +declarations. Currently only subprogram entities are supported. This +pragma is semantically equivalent to +@code{__attribute__((@var{string_expression}))} in GNU C, +where @code{@var{string_expression}} is recognized by the GNU C macros @code{VALID_MACHINE_TYPE_ATTRIBUTE} and @code{VALID_MACHINE_DECL_ATTRIBUTE} which are defined in the configuration header file @file{tm.h} for each machine. See the GCC @@ -2110,8 +2141,8 @@ MAIN_STORAGE_OPTION ::= @end smallexample @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 +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. @findex No_Return @@ -2125,10 +2156,10 @@ pragma No_Return (procedure_LOCAL_NAME); @noindent @var{procedure_local_NAME} must refer to one or more procedure -declarations in the current declarative part. A procedure to which this +declarations in the current declarative part. A procedure to which this pragma is applied may not contain any explicit @code{return} statements, and also may not contain any implicit return statements from falling off -the end of a statement sequence. One use of this pragma is to identify +the end of a statement sequence. One use of this pragma is to identify procedures whose only purpose is to raise an exception. Another use of this pragma is to suppress incorrect warnings about @@ -2145,14 +2176,14 @@ pragma Passive ([Semaphore | No]); @end smallexample @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 no 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 -optimized. GNAT does not attempt to optimize any tasks in this manner +optimized. GNAT does not attempt to optimize any tasks in this manner (since protected objects are available in place of passive tasks). @findex Polling @@ -2165,35 +2196,35 @@ pragma Polling (ON | OFF); @end smallexample @noindent -This pragma controls the generation of polling code. This is normally off. +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 Ada.Exceptions.Poll. This routine is a separate unit in the -runtime library, and can be found in file a-excpol.adb. +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}. -Pragma polling can appear as a configuration pragma (for example it can be -placed in the gnat.adc file) to enable polling globally, or it can be used +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 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 Poll +at the start of every subprogram call. This guarantees that the @code{Poll} routine is called frequently, and places an upper bound (determined by -the complexity of the code) on the period between two Poll calls. +the complexity of the code) on the period between two @code{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 Ada.Exceptions package that can be found -in files a-except.ads/adb. +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}. -A standard alternative unit (called 4wexcpol.adb in the standard GNAT +A standard alternative unit (in file @file{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 Poll +targets that do not normally support the capability. The version of @code{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 -gnatP switch. See -the GNAT User's Guide for details. +Note that polling can also be enabled by use of the @code{-gnatP} switch. See +the @cite{GNAT User's Guide} for details. @findex Propagate_Exceptions @cindex Zero Cost Exceptions @@ -2208,28 +2239,28 @@ pragma Propagate_Exceptions (subprogram_LOCAL_NAME); @noindent This pragma indicates that the given entity, which is the name of an imported foreign-language subprogram may receive an Ada exception, -and that the exception should be propagated. It is relevant only if +and that the exception should be propagated. It is relevant only if zero cost exception handling is in use, and is thus never needed if -the alternative longjmp/setjmp implementation of exceptions is used +the alternative @code{longjmp} / @code{setjmp} implementation of exceptions is used (although it is harmless to use it in such cases). The implementation of fast exceptions always properly propagates exceptions through Ada code, as described in the Ada Reference Manual. However, this manual is silent about the propagation of exceptions -through foreign code. For example, consider the +through foreign code. For example, consider the situation where @code{P1} calls @code{P2}, and @code{P2} calls @code{P3}, where @code{P1} and @code{P3} are in Ada, but @code{P2} is in C@. -@code{P3} raises an Ada exception. The question is whether or not +@code{P3} raises an Ada exception. The question is whether or not it will be propagated through @code{P2} and can be handled in @code{P1}. -For the longjmp/setjmp implementation of exceptions, the answer is -always yes. For some targets on which zero cost exception handling -is implemented, the answer is also always yes. However, there are +For the @code{longjmp} / @code{setjmp} implementation of exceptions, the answer is +always yes. For some targets on which zero cost exception handling +is implemented, the answer is also always yes. However, there are some targets, notably in the current version all x86 architecture targets, in which the answer is that such propagation does not -happen automatically. If such propagation is required on these +happen automatically. If such propagation is required on these targets, it is mandatory to use @code{Propagate_Exceptions} to name all foreign language routines through which Ada exceptions may be propagated. @@ -2265,36 +2296,36 @@ pragma Pure_Function ([Entity =>] function_LOCAL_NAME); 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). If specifies that the function @code{Entity} is -to be considered pure for the purposes of code generation. This means +to all entities). If specifies that the function @code{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 -same result. It also means that the function can be used in an +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 @var{Pure_Function} can be used +to ensure that this promise is met, so @code{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 +global variables. For example, a square root function that is instrumented to count the number of times it is called is still conceptually pure, and can still be optimized, even though it -modifies a global variable (the count). Memo functions are another +modifies a global variable (the count). Memo functions are another example (where a table of previous calls is kept and consulted to avoid re-computation). @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. An +there is no need to use pragma @code{Pure_Function} for such functions. An 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 +@code{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 -referenced data may change even if the address value does not. The use -of pragma Pure_Function for such a function will override this default +referenced data may change even if the address value does not. The use +of pragma @code{Pure_Function} for such a function will override this default assumption, and cause the compiler to treat such a function as pure. Note: If pragma @code{Pure_Function} is applied to a renamed function, it -applies to the underlying renamed function. This can be used to +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. @@ -2394,22 +2425,22 @@ For the Ravenscar pragma the value if always 0. Tasks which terminate are erroneous. @item No_Entry_Queue -No task can be queued on a protected entry. Note that this restrictions is -checked at run time. The violation of this restriction generates a +No task can be queued on a protected entry. Note that this restrictions is +checked at run time. The violation of this restriction generates a Program_Error exception. @end table @noindent -This set of restrictions corresponds to the definition of the "Ravenscar -Profile" for limited tasking, devised and published by the International -Workshop On Real Time Ada", 1997. +This set of restrictions corresponds to the definition of the ``Ravenscar +Profile'' for limited tasking, devised and published by the @cite{International +Real-Time Ada Workshop}, 1997. The above set is a superset of the restrictions provided by pragma @code{Restricted_Run_Time}, it includes six additional restrictions (@code{Boolean_Entry_Barriers}, @code{No_Select_Statements}, @code{No_Calendar}, @code{Static_Storage_Size}, -@code{No_Relative_Delay} and @code{No_Task_Termination}). This means -that pragma Ravenscar, like the pragma Restricted_Run_Time, automatically +@code{No_Relative_Delay} and @code{No_Task_Termination}). This means +that pragma @code{Ravenscar}, like the pragma @code{Restricted_Run_Time}, automatically causes the use of a simplified, more efficient version of the tasking run-time system. @@ -2460,8 +2491,8 @@ pragma Share_Generic (NAME @{, NAME@}); @noindent This pragma is recognized for compatibility with other Ada compilers -but is ignored by GNAT@. GNAT does not provide the capability for -sharing of generic code. All generic instantiations result in making +but is ignored by GNAT@. GNAT does not provide the capability for +sharing of generic code. All generic instantiations result in making an inlined copy of the template with appropriate substitutions. @findex Source_File_Name @@ -2480,11 +2511,11 @@ pragma Source_File_Name ( @end smallexample @noindent -Use this to override the normal naming convention. It is a configuration +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 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 +@var{unit_name} is mapped to @var{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. @@ -2514,14 +2545,14 @@ CASING_SPEC ::= Lowercase | Uppercase | Mixedcase @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 +to form the file name. The second argument is optional. If present it specifies the casing of the unit name in the resulting file name string. -The default is lower case. Finally the third argument allows for systematic +The default is lower case. Finally the third argument allows for systematic replacement of any dots in the unit name by the specified string literal. For more details on the use of the @code{Source_File_Name} pragma, -see the sections "Using Other File Names", and "Alternative File -Naming Schemes" in the GNAT User's Guide. +see the sections ``Using Other File Names'' and +``Alternative File Naming Schemes'' in the @cite{GNAT User's Guide}. @findex Source_Reference @item pragma Source_Reference @@ -2537,14 +2568,14 @@ pragma Source_Reference (INTEGER_LITERAL, This pragma must appear as the first line of a source file. @var{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). @var{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 @samp{-r} switch, to make sure that the original unchopped +information. This is most notably used for the output of @code{gnatchop} +with the @code{-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 +string expression other than a string literal. This is because its value is needed for error messages issued by all phases of the compiler. @findex Stream_Convert @@ -2561,16 +2592,16 @@ pragma Stream_Convert ( @noindent This pragma provides an efficient way of providing stream functions for -types defined in packages. Not only is it simpler to use than declaring +types defined in packages. Not only is it simpler to use than declaring the necessary functions with attribute representation clauses, but more significantly, it allows the declaration to made in such a way that the -stream packages are not loaded unless they are needed. The use of +stream packages are not loaded unless they are needed. The use of the Stream_Convert pragma adds no overhead at all, unless the stream attributes are actually used on the designated type. The first argument specifies the type for which stream functions are -provided. The second parameter provides a function used to read values -of this type. It must name a function whose argument type may be any +provided. The second parameter provides a function used to read values +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. @@ -2588,7 +2619,7 @@ and the return type must be the same as the input type of the Read function. The effect is to first call the Write function to convert to the given stream type, and then write the result type to the stream. -The Read and Write functions must not be overloaded subprograms. If necessary +The Read and Write functions must not be overloaded subprograms. If necessary 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: @@ -2632,28 +2663,28 @@ pragma Style_Checks (string_LITERAL | ALL_CHECKS | @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 +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 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 @code{-gnaty} switch on the @code{gcc} or @code{gnatmake} -line. For example the following two methods can be used to enable +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 @code{-gnaty} switch to @code{gcc} or @code{gnatmake}. +For example the following two methods can be used to enable layout checking: @smallexample pragma Style_Checks ("l"); -gcc -c -gnatyl ... +gcc -c -gnatyl @dots{} @end smallexample @noindent The form ALL_CHECKS activates all standard checks (its use is equivalent -to the use of the @code{gnaty} switch with no options. See GNAT User's +to the use of the @code{gnaty} switch with no options. See GNAT User's Guide for details. The forms with @code{Off} and @code{On} @@ -2673,7 +2704,7 @@ NULL; -- this will generate an error message @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 +@code{On} or @code{Off}. The effect is to turn of semantic style checks for the specified entity, as shown in the following example: @smallexample @@ -2711,9 +2742,9 @@ pragma Suppress_All; @noindent This pragma can only appear immediately following a compilation -unit. The effect is to apply @code{Suppress (All_Checks)} to the unit -which it follows. This pragma is implemented for compatibility with DEC -Ada 83 usage. The use of pragma @code{Suppress (All_Checks)} as a normal +unit. The effect is to apply @code{Suppress (All_Checks)} to the unit +which it follows. This pragma is implemented for compatibility with DEC +Ada 83 usage. The use of pragma @code{Suppress (All_Checks)} as a normal configuration pragma is the preferred usage in GNAT@. @findex Suppress_Initialization @@ -2742,11 +2773,11 @@ pragma Task_Info (EXPRESSION); @noindent This pragma appears within a task definition (like pragma -@code{Priority}) and applies to the task in which it appears. The +@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 aspect of tasking implementation, for example, the ability to map -tasks to specific processors. For details on the facilities available +tasks to specific processors. For details on the facilities available for the version of GNAT that you are using, see the documentation in the specification of package System.Task_Info in the runtime library. @@ -2762,16 +2793,16 @@ pragma Task_Name (string_EXPRESSION); @noindent This pragma appears within a task definition (like pragma -@code{Priority}) and applies to the task in which it appears. The +@code{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 +the task instance when the task is created. Note that this expression is not required to be static, and in particular, it can contain -references to task discriminants. This facility can be used to +references to task discriminants. This facility can be used to provide different names for different tasks as they are created, 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 +and is accessible to tools like the debugger. In addition the routine @code{Ada.Task_Identification.Image} will return this string, with a unique task address appended. @@ -2819,7 +2850,7 @@ pragma Task_Storage 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 +created, depending on the target. This pragma can appear anywhere a @code{Storage_Size} attribute definition clause is allowed for a task type. @@ -2855,9 +2886,9 @@ TITLING_OPTION ::= @end smallexample @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 +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 @@ -2879,7 +2910,7 @@ pragma Unchecked_Union (first_subtype_LOCAL_NAME) This pragma is used to declare that the specified type should be represented in a manner equivalent to a C union type, and is intended only for use in -interfacing with C code that uses union types. In Ada terms, the named +interfacing with C code that uses union types. In Ada terms, the named type must obey the following rules: @itemize @bullet @@ -2916,9 +2947,9 @@ discriminant. Equality and inequality operations on @code{unchecked_unions} are not available, since there is no discriminant to compare and the compiler -does not even know how many bits to compare. It is implementation +does not even know how many bits to compare. It is implementation dependent whether this is detected at compile time as an illegality or -whether it is undetected and considered to be an erroneous construct. In +whether it is undetected and considered to be an erroneous construct. In GNAT, a direct comparison is illegal, but GNAT does not attempt to catch the composite case (where two composites are compared that contain an unchecked union component), so such comparisons are simply considered @@ -2926,7 +2957,7 @@ erroneous. The layout of the resulting type corresponds exactly to a C union, where each branch of the union corresponds to a single variant in the Ada -record. The semantics of the Ada program is not changed in any way by +record. The semantics of the Ada program is not changed in any way by the pragma, i.e.@: provided the above restrictions are followed, and no erroneous incorrect references to fields or erroneous comparisons occur, the semantics is exactly as described by the Ada reference manual. @@ -2952,6 +2983,32 @@ 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. +@findex Unreferenced +@item pragma Unreferenced +@cindex Warnings, unreferenced +@noindent +Syntax: + +@smallexample +pragma Unreferenced (local_Name @{, local_Name@}); +@end smallexample + +@noindent +This pragma signals that the entities whose names are listed are +deliberately not referenced. This suppresses warnings about the +entities being unreferenced, and in addition a warning will be +generated if one of these entities is in fact referenced. + +This is particularly useful for clearly signalling that a particular +parameter is not referenced in some particular subprogram implementation +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 +current scope, then the entity most recently declared is the one to which +the pragma applies. + @findex Unreserve_All_Interrupts @item pragma Unreserve_All_Interrupts @noindent @@ -2962,26 +3019,26 @@ pragma Unreserve_All_Interrupts; @end smallexample @noindent -Normally certain interrupts are reserved to the implementation. Any attempt +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 @code{Ctrl-C} interrupt. Normally this interrupt is -reserved to the implementation, so that @code{Ctrl-C} can be used to +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. -If the pragma Unreserve_All_Interrupts appears anywhere in any unit in -a program, then all such interrupts are unreserved. This allows the +If the pragma @code{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 -@code{Ctrl-C} will not automatically interrupt execution. However, +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. For a full list of the interrupts handled in a specific implementation, -see the source code for the specification of Ada.Interrupts.Names in -file a-intnam.ads. This is a target dependent file that contains the -list of interrupts recognized for a given target. The documentation in +see the source code for the specification of @code{Ada.Interrupts.Names} in +file @file{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 Unreserve_All_Interrupts pragma. +the @code{Unreserve_All_Interrupts} pragma. @findex Unsuppress @item pragma Unsuppress @@ -2993,10 +3050,10 @@ pragma Unsuppress (IDENTIFIER [, [On =>] NAME]); @end smallexample @noindent -This pragma undoes the effect of a previous pragma @code{Suppress}. If +This pragma undoes the effect of a previous pragma @code{Suppress}. If there is no corresponding pragma @code{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 +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}. One important application is to ensure that checks are on in cases where @@ -3015,12 +3072,12 @@ pragma Use_VADS_Size; @end smallexample @noindent -This is a configuration pragma. In a unit to which it applies, any use +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 -processing of valid Ada 95 programs. This is intended to aid in the +'VADS_Size attribute. Note that this may result in incorrect semantic +processing of valid Ada 95 programs. This is intended to aid in the handling of legacy code which depends on the interpretation of Size -as implemented in the VADS compiler. See description of the VADS_Size +as implemented in the VADS compiler. See description of the VADS_Size attribute for further details. @findex Validity_Checks @@ -3034,25 +3091,25 @@ pragma Validity_Checks (string_LITERAL | ALL_CHECKS | On | Off); @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 +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 form with a string literal specifies which validity options are to be -activated. The validity checks are first set to include only the default +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 +specifies the exact set of options required. The form of this string is exactly as described for the @code{-gnatVx} compiler switch (see the -GNAT users guide for details). For example the following two methods +GNAT users 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: @smallexample pragma Validity_Checks ("im"); -gcc -c -gnatVim ... +gcc -c -gnatVim @dots{} @end smallexample @noindent @@ -3085,9 +3142,9 @@ pragma Volatile (local_NAME) @noindent This pragma is defined by the Ada 95 Reference Manual, and the GNAT -implementation is fully conformant with this definition. The reason it +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 -in some Ada 83 compilers, including DEC Ada 83. The Ada 95 implementation +in some Ada 83 compilers, including DEC Ada 83. The Ada 95 implementation of pragma Volatile is upwards compatible with the implementation in Dec Ada 83. @@ -3102,16 +3159,16 @@ pragma Warnings (On | Off [, LOCAL_NAME]); @noindent Normally warnings are enabled, with the output being controlled by -the command line switch. Warnings (@code{Off}) turns off generation of +the command line switch. Warnings (@code{Off}) turns off generation of warnings until a Warnings (@code{On}) is encountered or the end of the -current unit. If generation of warnings is turned off using this +current unit. If generation of warnings is turned off using this pragma, then no warning messages are output, regardless of the setting of the command line switches. The form with a single argument is a configuration pragma. If the @var{local_name} parameter is present, warnings are suppressed for -the specified entity. This suppression is effective from the point where +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}). @@ -3126,7 +3183,7 @@ pragma Weak_External ([Entity =>] LOCAL_NAME); @noindent This pragma specifies that the given entity should be marked as a weak -external (one that does not have to be resolved) for the linker. For +external (one that does not have to be resolved) for the linker. For further details, consult the GCC manual. @end table @@ -3135,18 +3192,18 @@ further details, consult the GCC manual. Ada 95 defines (throughout the Ada 95 reference manual, summarized in annex K), a set of attributes that provide useful additional functionality in all -areas of the language. These language defined attributes are implemented +areas of the language. These language defined attributes are implemented in GNAT and work as described in the Ada 95 Reference Manual. In addition, Ada 95 allows implementations to define additional -attributes whose meaning is defined by the implementation. GNAT provides +attributes whose meaning is defined by the implementation. GNAT provides a number of these implementation-dependent attributes which can be used -to extend and enhance the functionality of the compiler. This section of +to extend and enhance the functionality of the compiler. This section of the GNAT reference manual describes these additional attributes. Note that any program using these attributes may not be portable to other compilers (although GNAT implements this set of attributes on all -platforms). Therefore if portability to other compilers is an important +platforms). Therefore if portability to other compilers is an important consideration, you should minimize the use of these attributes. @table @code @@ -3155,7 +3212,7 @@ consideration, you should minimize the use of these attributes. @noindent @code{Standard'Abort_Signal} (@code{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 +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). @@ -3166,7 +3223,7 @@ intercept the abort exception). @noindent @code{Standard'Address_Size} (@code{Standard} is the only allowed prefix) is a static constant giving the number of bits in an -@code{Address}. It is used primarily for constructing the definition of +@code{Address}. It is used primarily for constructing the definition of @code{Memory_Size} in package @code{Standard}, but may be freely used in user programs and has the advantage of being static, while a direct reference to System.Address'Size is non-static because Address @@ -3177,10 +3234,10 @@ is a private type. @noindent The @code{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 +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 -value to be used as the input argument. The possible values for 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} @@ -3190,11 +3247,11 @@ the configuration file used to built the GCC back end. @noindent The @code{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) +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 -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 +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}. @@ -3204,32 +3261,32 @@ either be omitted, or explicitly given as @code{No_Output_Operands}. @findex AST_Entry @item AST_Entry @noindent -This attribute is implemented only in OpenVMS versions of GNAT@. Applied to +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 Extend_System (Aux_DEC)). This value enables the given entry to -be called when an AST occurs. For further details, refer to the DEC Ada -Language Reference Manual, section 9.12a. +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. @findex Bit @item Bit @code{@var{obj}'Bit}, where @var{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 +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}. 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 +the value is zero. (The use of this attribute does not force the allocation of a variable to memory). For an object that is a formal parameter, this attribute applies 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 +For an access object the value is zero. Note that @code{@var{obj}.all'Bit} is subject to an @code{Access_Check} for the -designated object. Similarly for a record component +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} are subject to index checks. @@ -3243,8 +3300,8 @@ and implementation of the @code{Bit} attribute. @code{@var{R.C}'Bit}, where @var{R} is a record object and 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 +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}. @@ -3260,7 +3317,7 @@ an address value which can be used to call the subprogram by means of an address clause as in the following example: @smallexample -procedure K is ... +procedure K is @dots{} procedure L; for L'Address use K'Address; @@ -3268,16 +3325,16 @@ pragma Import (Ada, L); @end smallexample @noindent -A call to L is then expected to result in a call to K@. In Ada 83, where +A call to @code{L} is then expected to result in a call to @code{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 Address and the technique illustrated +GNAT implements the above use of @code{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 Address value described above. For example, -the Address value may reference a subprogram descriptor rather than the +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 descriptor rather than the subprogram itself. The @code{'Code_Address} attribute, which can only be applied to @@ -3294,25 +3351,25 @@ attribute. @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{Low_Order_First}). This is used to construct the definition of @code{Default_Bit_Order} in package @code{System}. @findex Elaborated @item Elaborated @noindent -The prefix of the @code{'Elaborated} attribute must be a unit name. The +The prefix of the @code{'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 +elaborated. This attribute is primarily intended for internal use by the generated code for dynamic elaboration checking, but it can also be used -in user programs. The value will always be True once elaboration of all +in user programs. The value will always be True once elaboration of all units has been completed. @findex Elab_Body @item Elab_Body @noindent -This attribute can only be applied to a program unit name. It returns +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 +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, @@ -3322,9 +3379,9 @@ error. @findex Elab_Spec @item Elab_Spec @noindent -This attribute can only be applied to a program unit name. It returns +This attribute can only be applied to a program unit name. It returns the entity for the corresponding elaboration procedure for elaborating -the specification of the referenced unit. This is used in the main +the specification 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 @@ -3335,7 +3392,7 @@ some error. @findex Emax @item Emax @noindent -The @code{Emax} attribute is provided for compatibility with Ada 83. See +The @code{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. @@ -3352,22 +3409,22 @@ function @var{S}'Enum_Rep (Arg : @var{S}'Base) @end smallexample @noindent -It is also allowable to apply Enum_Rep directly to an object of an +It is also allowable to apply @code{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 +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 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 -absence of an enumeration representation clause. This is a static +value. This will be equal to value of the @code{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). -@var{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 (<>) discrete formal arguments in a generic unit that -can be instantiated with either enumeration types or integer types. Note -that if Enum_Rep is used on a modular type whose upper bound exceeds the +@code{@var{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 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 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}. @@ -3376,7 +3433,7 @@ then the call to @code{Enum_Rep} may raise @code{Constraint_Error}. @findex Epsilon @item Epsilon @noindent -The @code{Epsilon} attribute is provided for compatibility with Ada 83. See +The @code{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. @@ -3401,7 +3458,7 @@ The value returned is the fixed-point value @var{V} such that @noindent The effect is thus equivalent to first converting the argument to the integer type used to represent @var{S}, and then doing an unchecked -conversion to the fixed-point type. This attribute is primarily intended +conversion to the fixed-point type. This attribute is primarily intended for use in implementation of the input-output functions for fixed-point values. @@ -3409,10 +3466,10 @@ values. @findex Has_Discriminants @item Has_Discriminants @noindent -The prefix of the @code{Has_Discriminants} attribute is a type. The result +The prefix of the @code{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 +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. @findex Img @@ -3420,7 +3477,7 @@ indicates whether or not the corresponding actual type has discriminants. @noindent The @code{Img} attribute differs from @code{Image} in that it may be applied to objects as well as types, in which case it gives the -@code{Image} for the subtype of the object. This is convenient for +@code{Image} for the subtype of the object. This is convenient for debugging: @smallexample @@ -3457,7 +3514,7 @@ Arg = @var{V} * @var{type}'Small @noindent The effect is thus equivalent to first doing an unchecked convert from the fixed-point type to its corresponding implementation type, and then -converting the result to the target integer type. This attribute is +converting the result to the target integer type. This attribute is primarily intended for use in implementation of the standard input-output functions for fixed-point values. @@ -3465,21 +3522,21 @@ input-output functions for fixed-point values. @findex Large @item Large @noindent -The @code{Large} attribute is provided for compatibility with Ada 83. See +The @code{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. @findex Machine_Size @item Machine_Size @noindent -This attribute is identical to the @code{Object_Size} attribute. It is +This attribute is identical to the @code{Object_Size} attribute. It is provided for compatibility with the DEC Ada 83 attribute of this name. @cindex Ada 83 attributes @findex Mantissa @item Mantissa @noindent -The @code{Mantissa} attribute is provided for compatibility with Ada 83. See +The @code{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. @@ -3506,9 +3563,9 @@ primarily for constructing this definition in package @code{System}. @noindent @code{Standard'Maximum_Alignment} (@code{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 +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. This is useful when an external object is imported and its +cases. This is useful when an external object is imported and its alignment requirements are unknown. @cindex Return values, passing mechanism @@ -3520,7 +3577,7 @@ alignment requirements are unknown. 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: +meaning the first parameter) of @var{subprogram}. The code returned is: @table @asis @item 1 @@ -3546,16 +3603,16 @@ by descriptor (NCA: non-contiguous array) @end table @cindex OpenVMS -Values from 3-10 are only relevant to Digital OpenVMS implementations. +Values from 3 through 10 are only relevant to Digital OpenVMS implementations. @cindex Zero address, passing @findex Null_Parameter @item 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 +type or subtype @var{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 +an actual expression of a subprogram call. In either case, the subprogram must be imported. The identity of the object is represented by the address zero in the @@ -3572,8 +3629,8 @@ attribute. @item Object_Size @noindent 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, +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. Similarly, a record containing an integer and a character: @@ -3586,20 +3643,20 @@ end record; @end smallexample @noindent -will have a size of 40 (that is @code{Rec'Size} will be 40. The +will have a size of 40 (that is @code{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). The @code{@var{type}'Object_Size} attribute has been added to GNAT to allow the -default object size of a type to be easily determined. For example, +default object size of a type to be easily determined. For example, @code{Natural'Object_Size} is 32, and @code{Rec'Object_Size} (for the record type in the above example) will be -64. Note also that, unlike the situation with the +64. Note also that, unlike the situation with the @code{Size} attribute as defined in the Ada RM, the @code{Object_Size} attribute can be specified individually -for different subtypes. For example: +for different subtypes. For example: @smallexample type R is new Integer; @@ -3611,9 +3668,9 @@ for R2'Object_Size use 8; @noindent In this example, @code{R'Object_Size} and @code{R1'Object_Size} are both 32 since the default object size for a subtype is the same as the object size -for the parent subtype. This means that objects of type @code{R} +for the parent subtype. This means that objects of type @code{R} or @code{R1} will -by default be 32 bits (four bytes). But objects of type +by default be 32 bits (four bytes). But objects of type @code{R2} will be only 8 bits (one byte), since @code{R2'Object_Size} has been set to 8. @@ -3624,15 +3681,15 @@ by default be 32 bits (four bytes). But objects of type @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} -and is static. For non-scalar types, the result is non-static. +passed by copy in calls. For scalar types, the result is always @code{False} +and is static. For non-scalar types, the result is non-static. @findex Range_Length @item Range_Length @noindent @code{@var{type}'Range_Length} for any discrete type @var{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. @code{Range_Length} applied to the index subtype of a one dimensional array always gives the same result as @code{Range} applied to the array itself. @@ -3640,7 +3697,7 @@ same result as @code{Range} applied to the array itself. @findex Safe_Emax @item Safe_Emax @noindent -The @code{Safe_Emax} attribute is provided for compatibility with Ada 83. See +The @code{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. @@ -3648,7 +3705,7 @@ this attribute. @findex Safe_Large @item Safe_Large @noindent -The @code{Safe_Large} attribute is provided for compatibility with Ada 83. See +The @code{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. @@ -3656,7 +3713,7 @@ this attribute. @findex Safe_Large @item Safe_Large @noindent -The @code{Safe_Large} attribute is provided for compatibility with Ada 83. See +The @code{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. @@ -3666,7 +3723,7 @@ this attribute. @noindent The @code{Small} attribute is defined in Ada 95 only for fixed-point types. GNAT also allows this attribute to be applied to floating-point types -for compatibility with Ada 83. See +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. @@ -3691,9 +3748,9 @@ The @code{System'To_Address} (@code{System} is the only permissible prefix) denotes a function identical to @code{System.Storage_Elements.To_Address} except that -it is a static attribute. This means that if its argument is +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. The result is that such an expression can be +static expression. The result is that such an expression can be 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 @@ -3703,7 +3760,7 @@ argument is static). @item 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 +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 corresponding actual subtype. The value of this attribute is of type @code{System.Aux_DEC.Type_Class}, which has the following definition: @@ -3723,17 +3780,17 @@ corresponding actual subtype. The value of this attribute is of type @noindent Protected types yield the value @code{Type_Class_Task}, which thus -applies to all concurrent types. This attribute is designed to +applies to all concurrent types. This attribute is designed to be compatible with the DEC Ada 83 attribute of the same name. @findex UET_Address @item UET_Address @noindent The @code{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,a-except.adb} +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} for details on how this attribute is used in the implementation. @cindex Named numbers, representation of @@ -3741,11 +3798,11 @@ for details on how this attribute is used in the implementation. @item Universal_Literal_String @noindent The prefix of @code{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 +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 conversions and without the need to enclose the strings in quotes (which -would preclude their use as numbers). This is used internally for the +would preclude their use as numbers). This is used internally for the construction of values of the floating-point attributes from the file @file{ttypef.ads}, but may also be used by user programs. @@ -3754,12 +3811,12 @@ construction of values of the floating-point attributes from the file @item Unrestricted_Access @noindent The @code{Unrestricted_Access} attribute is similar to @code{Access} -except that all accessibility and aliased view checks are omitted. This +except that all accessibility and aliased view checks are omitted. This is a user-beware attribute. It is similar to @code{Address}, for which it is a desirable replacement where the value -desired is an access type. In other words, its effect is identical to +desired is an access type. In other words, its effect is identical to first applying the @code{Address} attribute and then doing an unchecked -conversion to a desired access type. In GNAT, but not necessarily in +conversion to a desired access type. In GNAT, but not necessarily in other implementations, the use of static chains for inner level subprograms means that @code{Unrestricted_Access} applied to a subprogram yields a value that can be called as long as the subprogram @@ -3771,11 +3828,11 @@ is in scope (normal Ada 95 accessibility rules restrict this usage). @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 -by the VADS Ada 83 compiler. GNAT makes a best effort at duplicating the -same semantic interpretation. In particular, @code{'VADS_Size} applied +by the VADS Ada 83 compiler. GNAT makes a best effort at duplicating the +same semantic interpretation. In particular, @code{'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 +typical machines). In addition @code{'VADS_Size} applied to an object gives the result that would be obtained by applying the attribute to the corresponding type. @@ -3783,7 +3840,7 @@ the corresponding type. @findex Value_Size @item 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}, +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. @findex Wchar_T_Size @@ -3807,19 +3864,19 @@ these requirements. In addition, there are sections throughout the Ada 95 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 +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 95 Reference Manual. This chapter contains a table giving the +the Ada 95 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 +by the GNAT interpretation of this 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. @@ -3832,7 +3889,7 @@ 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 -Not relevant. All specialized needs annex features are either supported, +Not relevant. All specialized needs annex features are either supported, or diagnosed at compile time. @cindex Child Units @@ -3853,7 +3910,7 @@ If an implementation detects a bounded error or erroneous execution, it should raise @code{Program_Error}. @end cartouche Followed in all cases in which the implementation detects a bounded -error or erroneous execution. Not all such situations are detected at +error or erroneous execution. Not all such situations are detected at runtime. @cindex Pragmas @@ -3896,7 +3953,7 @@ Affects semantics @end table 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 +that this advice not be followed. For details see the separate section on implementation defined pragmas. @item 2.8(17-19): Pragmas @@ -3924,10 +3981,10 @@ See response to paragraph 16 of this same section. 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 +subset of the set of graphic characters of @code{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 +@code{Characters.Handling} (see A.3) available in such a mode. In a mode with an alternative interpretation of @code{Character}, the implementation should also support a corresponding change in what is a legal @code{identifier_letter}. @@ -3936,7 +3993,7 @@ 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 subset, since the most significant bit is used for wide character -encoding. However, this only applies to the external forms. Internally +encoding. However, this only applies to the external forms. Internally there is no such restriction. @cindex Integer types @@ -3946,12 +4003,12 @@ there is no such restriction. @cartouche An implementation should support @code{Long_Integer} in addition to @code{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 +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 -so this advice is not fully followed. These types +@code{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. @item 3.5.4(29): Integer Types @@ -3959,7 +4016,7 @@ types of the machine are easily available. @sp 1 @cartouche 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 +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 Followed. @@ -3972,7 +4029,7 @@ For the evaluation of a call on @code{@var{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 +@code{Program_Error}. This is particularly important for enumeration types with noncontiguous internal codes specified by an enumeration_representation_clause. @end cartouche @@ -3984,19 +4041,19 @@ Followed. @cartouche An implementation should support @code{Long_Float} in addition to @code{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 +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 +@code{Short_Float} and @code{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 +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 -correspond to the IEEE extended form. The notable case is all ia32 +correspond to the IEEE extended form. The notable case is all ia32 (x86) implementations, where @code{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, +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 @@ -4006,8 +4063,8 @@ since this is a software rather than a hardware format. @cartouche 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}, ...) applies to a multidimensional array type, then +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 @@ -4020,7 +4077,7 @@ Followed. 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**(-9)). +Followed. (@code{Duration'Small} = 10**(@minus{}9)). @sp 1 @cartouche @@ -4038,10 +4095,10 @@ 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 -Followed, except in the case of tagged types. Tagged types involve +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 +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 @@ -4050,17 +4107,17 @@ advice without severely impacting efficiency of execution. @cartouche @code{Exception_Message} by default and @code{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. @code{Exception_Message} should be short, about one +line. @code{Exception_Information} can be long. @code{Exception_Message} should not include the -@code{Exception_Name}. @code{Exception_Information} should include both +@code{Exception_Name}. @code{Exception_Information} should include both the @code{Exception_Name} and the @code{Exception_Message}. @end cartouche -Followed. For each exception that doesn't have a specified +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 +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 -number in the file. Note that in the case of the Zero Cost Exception +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 @@ -4091,8 +4148,8 @@ 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 -Followed. GNAT does not support non-static expressions in representation -clauses unless they are constants declared before the entity. For +Followed. GNAT does not support non-static expressions in representation +clauses unless they are constants declared before the entity. For example: @smallexample @@ -4101,7 +4158,7 @@ for X'Address use To_address (16#2000#); @end smallexample @noindent -will be rejected, since the To_Address expression is non-static. Instead +will be rejected, since the To_Address expression is non-static. Instead write: @smallexample @@ -4119,7 +4176,7 @@ 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 -Followed. Size Clauses are not permitted on non-static components, as +Followed. Size Clauses are not permitted on non-static components, as described above. @sp 1 @@ -4146,10 +4203,10 @@ 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 implementation may, but need not, reorder components or cross aligned -word boundaries to improve the packing. A component whose @code{Size} is +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 -Followed. Tight packing of arrays is supported for all component sizes +Followed. Tight packing of arrays is supported for all component sizes up to 64-bits. @sp 1 @@ -4244,7 +4301,7 @@ Followed. @cartouche For stand-alone library-level objects of statically constrained subtypes, the implementation should support all @code{Alignment}s -supported by the target linker. For example, page alignment is likely to +supported by the target linker. For example, page alignment is likely to be supported for such objects, but not for subtypes. @end cartouche Followed. @@ -4291,7 +4348,7 @@ The recommended level of support for the @code{Size} attribute of subtypes is: The @code{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 +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 @@ -4322,9 +4379,9 @@ Followed. @sp 1 @cartouche An implementation should support specified @code{Component_Size}s that -are factors and multiples of the word size. For such +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 +components. For other @code{Component_Size}s (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. @@ -4382,8 +4439,8 @@ Followed. 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 -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 +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 @@ -4393,7 +4450,7 @@ 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 -Followed. The above advice on record representation clauses is followed, +Followed. The above advice on record representation clauses is followed, and all mentioned features are implemented. @cindex Storage place attributes @@ -4403,12 +4460,12 @@ and all mentioned features are implemented. 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 +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@. +Followed. There are no such components in GNAT@. @cindex Bit ordering @item 13.5.3(7-8): Bit Ordering @@ -4422,7 +4479,7 @@ If @code{Word_Size} = @code{Storage_Unit}, then the implementation should support the non-default bit ordering in addition to the default bit ordering. @end cartouche -Followed. Word size does not equal storage size in this implementation. +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 @@ -4439,11 +4496,11 @@ Followed. @sp 1 @cartouche Operations in @code{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.'' +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 -Followed. Address arithmetic is modular arithmetic that wraps around. No +Followed. Address arithmetic is modular arithmetic that wraps around. No operation raises @code{Program_Error}, since all operations make sense. @cindex Unchecked conversion @@ -4459,11 +4516,11 @@ Followed. @cartouche The implementation should not generate unnecessary run-time checks to ensure that the representation of @var{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 +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 -Followed. There are no restrictions on unchecked conversion. A warning is +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. @@ -4474,7 +4531,7 @@ The recommended level of support for unchecked conversions is: @sp 1 @cartouche Unchecked conversions should be supported and should be reversible in -the cases where this clause defines the result. To enable meaningful use +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, @@ -4503,14 +4560,14 @@ objects. To allocate space for a task when a task is created. @item -To extend the secondary stack dynamically when needed. The secondary +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 access-to- -constant type should not have overhead to support de-allocation of +A default (implementation-provided) storage pool for an +access-to-constant type should not have overhead to support deallocation of individual objects. @end cartouche Followed. @@ -4538,11 +4595,11 @@ Followed. @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} +@code{Write} for scalar objects. Otherwise, @code{Read} and @code{Write} should use the smallest number of stream elements needed to represent all values in the base range of the scalar type. @end cartouche -Followed. In particular, the interpretation chosen is that of AI-195, +Followed. In particular, the interpretation chosen is that of AI-195, which specifies that the size to be used is that of the first subtype. @item A.1(52): Implementation Advice @@ -4550,7 +4607,7 @@ which specifies that the size to be used is that of the first subtype. @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 +@samp{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 @@ -4562,10 +4619,10 @@ Followed. @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 +@code{Characters.Handling} should reflect the localizations. See also 3.5.2. @end cartouche -Followed. GNAT provides no such localized definitions. +Followed. GNAT provides no such localized definitions. @cindex Bounded-length strings @item A.4.4(106): Bounded-Length String Handling @@ -4574,7 +4631,7 @@ Followed. GNAT provides no such localized definitions. Bounded string objects should not be implemented by implicit pointers and dynamic allocation. @end cartouche -Followed. No implicit pointers or dynamic allocation are used. +Followed. No implicit pointers or dynamic allocation are used. @cindex Random number generation @item A.5.2(46-47): Random Number Generation @@ -4591,11 +4648,11 @@ 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 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 +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 -Followed. The generator period is sufficiently long for the first +Followed. The generator period is sufficiently long for the first condition here to hold true. @findex Get_Immediate @@ -4603,9 +4660,9 @@ condition here to hold true. @sp 1 @cartouche The @code{Get_Immediate} procedures should be implemented with -unbuffered input. For a device such as a keyboard, input should be +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 -file, input should always be available except at end of file. For a file +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}. @@ -4618,13 +4675,13 @@ Followed. @cartouche If an implementation supports pragma @code{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 +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 +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 -finalization code. These subprograms should have no effect the second +@code{adainit} and @code{adafinal}. @code{adainit} should contain the +elaboration code for library units. @code{adafinal} should contain the +finalization code. These subprograms should have no effect the second and subsequent time they are called. @end cartouche Followed. @@ -4632,9 +4689,9 @@ Followed. @sp 1 @cartouche Automatic elaboration of pre-elaborated packages should be -provided when pragma Export is supported. +provided when pragma @code{Export} is supported. @end cartouche -Followed when the main program is in Ada. If the main program is in a +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 packages. @@ -4645,7 +4702,7 @@ 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, -presuming the other language has corresponding features. Pragma +presuming the other language has corresponding features. Pragma @code{Convention} need not be supported for scalar types. @end cartouche Followed. @@ -4656,14 +4713,14 @@ Followed. @sp 1 @cartouche For each implementation-defined convention identifier, there should be a -child package of package Interfaces with the corresponding name. This +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 +convention. Any declarations useful for interfacing to any language on the given hardware architecture should be provided directly in @code{Interfaces}. @end cartouche -Followed. An additional package not defined +Followed. An additional package not defined in the Ada 95 Reference Manual is @code{Interfaces.CPP}, used for interfacing to C++. @@ -4673,7 +4730,7 @@ An implementation supporting an interface to C, COBOL, or Fortran should provide the corresponding package or packages described in the following clauses. @end cartouche -Followed. GNAT provides all the packages described in this section. +Followed. GNAT provides all the packages described in this section. @cindex C, interfacing with @item B.3(63-71): Interfacing with C @@ -4716,7 +4773,7 @@ Followed. 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 +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 @@ -4728,7 +4785,7 @@ 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 -Followed. This convention may be overridden by the use of the C_Pass_By_Copy +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. @@ -4759,21 +4816,21 @@ Followed. @sp 1 @cartouche -An Ada access @var{T} parameter is passed as a ``BY REFERENCE'' data item of +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 Followed. @sp 1 @cartouche -An Ada in scalar parameter is passed as a ``BY CONTENT'' data item of +An Ada in scalar parameter is passed as a @samp{BY CONTENT} data item of the corresponding COBOL type. @end cartouche Followed. @sp 1 @cartouche -Any other Ada parameter is passed as a ``BY REFERENCE'' data item of the +Any other Ada parameter is passed as a @samp{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 @@ -4807,7 +4864,7 @@ 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 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 +conventions are used. For elementary types, a local copy is used if necessary to ensure by-copy semantics. @end cartouche Followed. @@ -4843,7 +4900,7 @@ Followed. 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 +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 @@ -4864,30 +4921,30 @@ access to any machine operations that provide special capabilities or efficiency and that are not otherwise available through the language constructs. @end cartouche -Followed. A full set of machine operation intrinsic subprograms is provided. +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 +Atomic read-modify-write operations---e.g.@:, test and set, compare and swap, decrement and test, enqueue/dequeue. @end cartouche Followed on any target supporting such operations. @sp 1 @cartouche -Standard numeric functions -- e.g.@:, sin, log. +Standard numeric functions---e.g.@:, sin, log. @end cartouche Followed on any target supporting such operations. @sp 1 @cartouche -String manipulation operations -- e.g.@:, translate and test. +String manipulation operations---e.g.@:, translate and test. @end cartouche Followed on any target supporting such operations. @sp 1 @cartouche -Vector operations -- e.g.@:, compare vector against thresholds. +Vector operations---e.g.@:, compare vector against thresholds. @end cartouche Followed on any target supporting such operations. @@ -4906,7 +4963,7 @@ 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 -Followed. The underlying system does not allow for finer-grain control +Followed. The underlying system does not allow for finer-grain control of interrupt blocking. @cindex Protected procedure handlers @@ -4928,7 +4985,7 @@ such direct calls. Whenever practical, violations of any implementation-defined restrictions should be detected before run time. @end cartouche -Followed. Compile time warnings are given when possible. +Followed. Compile time warnings are given when possible. @cindex Package @code{Interrupts} @findex Interrupts @@ -4953,7 +5010,7 @@ 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 +Followed. Executable code is generated in some cases, e.g.@: loops to initialize large arrays. @item C.5(8): Pragma @code{Discard_Names} @@ -4972,15 +5029,15 @@ Followed. @sp 1 @cartouche Some implementations are targeted to domains in which memory use at run -time must be completely deterministic. For such implementations, it is +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 +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} -attribute objects, and the heap for the others. In the latter case, +attribute objects, and the heap for the others. In the latter case, @var{N} should be documented. @end cartouche -Not followed. This implementation is not targeted to such a domain. +Not followed. This implementation is not targeted to such a domain. @cindex Locking Policies @item D.3(17): Locking Policies @@ -4990,7 +5047,7 @@ Not followed. This implementation is not targeted to such a domain. The implementation should use names that end with @samp{_Locking} for locking policies defined by the implementation. @end cartouche -Followed. A single implementation-defined locking policy is defined, +Followed. A single implementation-defined locking policy is defined, whose name (@code{Inheritance_Locking}) follows this suggestion. @cindex Entry queuing policies @@ -5000,7 +5057,7 @@ whose name (@code{Inheritance_Locking}) follows this suggestion. Names that end with @samp{_Queuing} should be used for all implementation-defined queuing policies. @end cartouche -Followed. No such implementation-defined queueing policies exist. +Followed. No such implementation-defined queueing policies exist. @cindex Preemptive abort @item D.6(9-10): Preemptive Abort @@ -5030,7 +5087,7 @@ restrictions to produce a more efficient implementation. @end cartouche 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{Ravenscar} and pragma +of restrictions are specified. See pragma @code{Ravenscar} and pragma @code{Restricted_Run_Time} for more details. @cindex Time, monotonic @@ -5054,7 +5111,7 @@ Followed. @cartouche It is recommended that the @dfn{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. +@code{Clock}. @dfn{Best} may mean highest accuracy or largest range. @end cartouche Followed. @@ -5069,7 +5126,7 @@ should allow them to block until the corresponding subprogram body returns. @end cartouche Followed by GLADE, a separately supplied PCS that can be used with -GNAT. For information on GLADE, contact Ada Core Technologies. +GNAT. @sp 1 @cartouche @@ -5078,7 +5135,7 @@ should raise @code{Storage_Error} if it runs out of space trying to write the @code{Item} into the stream. @end cartouche Followed by GLADE, a separately supplied PCS that can be used with -GNAT@. For information on GLADE, contact Ada Core Technologies. +GNAT@. @cindex COBOL support @item F(7): COBOL Support @@ -5101,7 +5158,7 @@ Followed. 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 +Not followed. GNAT ignores @var{S}'Machine_Radix and always uses binary representations. @cindex Numerics @@ -5126,10 +5183,10 @@ 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 -performing a full complex multiplication. In systems that, in the +performing a full complex multiplication. In systems that, in the future, support an Ada binding to IEC 559:1989, the latter technique will not generate the required result when one of the components of the -complex operand is infinite. (Explicit multiplication of the infinite +complex operand is infinite. (Explicit multiplication of the infinite 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 @@ -5144,12 +5201,12 @@ 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} +complex addition. In implementations in which the @code{Signed_Zeros} attribute of the component type is @code{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 -operand is a negatively signed zero. (Explicit addition of the negative +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 @@ -5161,7 +5218,7 @@ Not followed. @cartouche Implementations in which @code{Real'Signed_Zeros} is @code{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 @code{Argument} function should have the sign of the imaginary component of the parameter @code{X} when the point represented by that parameter lies on the positive real axis; as another, the sign of the imaginary component @@ -5178,10 +5235,10 @@ Followed. @cartouche Implementations in which @code{Complex_Types.Real'Signed_Zeros} is @code{True} should attempt to provide a rational treatment of the signs -of zero results and result components. For example, many of the complex +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 +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. @@ -5196,7 +5253,7 @@ 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 -accuracy in some portions of the domain. For the same reason, the +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}. @@ -5222,12 +5279,12 @@ Followed. @chapter Implementation Defined Characteristics In addition to the implementation dependent pragmas and attributes, and the implementation advice, there are a number of other features of Ada -95 that are potentially implementation dependent. These are mentioned +95 that are potentially implementation dependent. These are mentioned throughout the Ada 95 Reference 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 -issues. In this chapter, you will find each point in annex M listed +issues. In this chapter, you will find each point in annex M listed followed by a description in italic font of how GNAT @c SGI info: @ignore @@ -5246,7 +5303,7 @@ Reference Manual. @cartouche @noindent @strong{2}. Whether or not each recommendation given in Implementation -Advice is followed. See 1.1.2(37). +Advice is followed. See 1.1.2(37). @end cartouche @noindent @xref{Implementation Advice}. @@ -5254,7 +5311,7 @@ Advice is followed. See 1.1.2(37). @sp 1 @cartouche @noindent -@strong{3}. Capacity limitations of the implementation. See 1.1.3(3). +@strong{3}. 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 @@ -5265,7 +5322,7 @@ generated object files. @cartouche @noindent @strong{4}. Variations from the standard that are impractical to avoid -given the implementation's execution environment. See 1.1.3(6). +given the implementation's execution environment. See 1.1.3(6). @end cartouche @noindent There are no variations from the standard. @@ -5274,7 +5331,7 @@ There are no variations from the standard. @cartouche @noindent @strong{5}. Which @code{code_statement}s cause external -interactions. See 1.1.3(10). +interactions. See 1.1.3(10). @end cartouche @noindent Any @code{code_statement} can potentially cause external interactions. @@ -5283,7 +5340,7 @@ Any @code{code_statement} can potentially cause external interactions. @cartouche @noindent @strong{6}. The coded representation for the text of an Ada -program. See 2.1(4). +program. See 2.1(4). @end cartouche @noindent See separate section on source representation. @@ -5291,7 +5348,7 @@ See separate section on source representation. @sp 1 @cartouche @noindent -@strong{7}. The control functions allowed in comments. See 2.1(14). +@strong{7}. The control functions allowed in comments. See 2.1(14). @end cartouche @noindent See separate section on source representation. @@ -5299,7 +5356,7 @@ See separate section on source representation. @sp 1 @cartouche @noindent -@strong{8}. The representation for an end of line. See 2.2(2). +@strong{8}. The representation for an end of line. See 2.2(2). @end cartouche @noindent See separate section on source representation. @@ -5308,7 +5365,7 @@ See separate section on source representation. @cartouche @noindent @strong{9}. Maximum supported line length and lexical element -length. See 2.2(15). +length. See 2.2(15). @end cartouche @noindent The maximum line length is 255 characters an the maximum length of a @@ -5317,7 +5374,7 @@ lexical element is also 255 characters. @sp 1 @cartouche @noindent -@strong{10}. Implementation defined pragmas. See 2.8(14). +@strong{10}. Implementation defined pragmas. See 2.8(14). @end cartouche @noindent @@ -5326,7 +5383,7 @@ lexical element is also 255 characters. @sp 1 @cartouche @noindent -@strong{11}. Effect of pragma @code{Optimize}. See 2.8(27). +@strong{11}. Effect of pragma @code{Optimize}. See 2.8(27). @end cartouche @noindent Pragma @code{Optimize}, if given with a @code{Time} or @code{Space} @@ -5338,19 +5395,19 @@ not. @noindent @strong{12}. 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 +@code{@var{S}'Wide_Image} are not defined in @code{Character}. See 3.5(37). @end cartouche @noindent The sequence of characters is as defined by the wide character encoding -method used for the source. See section on source representation for +method used for the source. See section on source representation for further details. @sp 1 @cartouche @noindent @strong{13}. The predefined integer types declared in -@code{Standard}. See 3.5.4(25). +@code{Standard}. See 3.5.4(25). @end cartouche @noindent @table @code @@ -5371,7 +5428,7 @@ further details. @cartouche @noindent @strong{14}. Any nonstandard integer types and the operators defined -for them. See 3.5.4(26). +for them. See 3.5.4(26). @end cartouche @noindent There are no nonstandard integer types. @@ -5380,7 +5437,7 @@ There are no nonstandard integer types. @cartouche @noindent @strong{15}. Any nonstandard real types and the operators defined for -them. See 3.5.6(8). +them. See 3.5.6(8). @end cartouche @noindent There are no nonstandard real types. @@ -5389,7 +5446,7 @@ There are no nonstandard real types. @cartouche @noindent @strong{16}. What combinations of requested decimal precision and range -are supported for floating point types. See 3.5.7(7). +are supported for floating point types. See 3.5.7(7). @end cartouche @noindent The precision and range is as defined by the IEEE standard. @@ -5398,7 +5455,7 @@ The precision and range is as defined by the IEEE standard. @cartouche @noindent @strong{17}. The predefined floating point types declared in -@code{Standard}. See 3.5.7(16). +@code{Standard}. See 3.5.7(16). @end cartouche @noindent @table @code @@ -5415,30 +5472,30 @@ The precision and range is as defined by the IEEE standard. @sp 1 @cartouche @noindent -@strong{18}. The small of an ordinary fixed point type. See 3.5.9(8). +@strong{18}. The small of an ordinary fixed point type. See 3.5.9(8). @end cartouche @noindent -@code{Fine_Delta} is 2**(-63) +@code{Fine_Delta} is 2**(@minus{}63) @sp 1 @cartouche @noindent @strong{19}. What combinations of small, range, and digits are -supported for fixed point types. See 3.5.9(10). +supported for fixed point types. See 3.5.9(10). @end cartouche @noindent 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. 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 +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 @cartouche @noindent @strong{20}. The result of @code{Tags.Expanded_Name} for types declared -within an unnamed @code{block_statement}. See 3.9(10). +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 @@ -5447,7 +5504,7 @@ decimal integer are allocated. @sp 1 @cartouche @noindent -@strong{21}. Implementation-defined attributes. See 4.1.4(12). +@strong{21}. Implementation-defined attributes. See 4.1.4(12). @end cartouche @noindent @xref{Implementation Defined Attributes}. @@ -5455,7 +5512,7 @@ decimal integer are allocated. @sp 1 @cartouche @noindent -@strong{22}. Any implementation-defined time types. See 9.6(6). +@strong{22}. Any implementation-defined time types. See 9.6(6). @end cartouche @noindent There are no implementation-defined time types. @@ -5466,13 +5523,13 @@ There are no implementation-defined time types. @strong{23}. The time base associated with relative delays. @end cartouche @noindent -See 9.6(20). The time base used is that provided by the C library +See 9.6(20). The time base used is that provided by the C library function @code{gettimeofday}. @sp 1 @cartouche @noindent -@strong{24}. The time base of the type @code{Calendar.Time}. See +@strong{24}. The time base of the type @code{Calendar.Time}. See 9.6(23). @end cartouche @noindent @@ -5483,7 +5540,7 @@ The time base used is that provided by the C library function @cartouche @noindent @strong{25}. The time zone used for package @code{Calendar} -operations. See 9.6(24). +operations. See 9.6(24). @end cartouche @noindent The time zone used by package @code{Calendar} is the current system time zone @@ -5494,7 +5551,7 @@ setting for local time, as accessed by the C library function @cartouche @noindent @strong{26}. Any limit on @code{delay_until_statements} of -@code{select_statements}. See 9.6(29). +@code{select_statements}. See 9.6(29). @end cartouche @noindent There are no such limits. @@ -5504,7 +5561,7 @@ There are no such limits. @noindent @strong{27}. 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 +layout, or @code{Component_Size} is specified for the object. See 9.10(1). @end cartouche @noindent @@ -5514,17 +5571,17 @@ overlapping storage units. @sp 1 @cartouche @noindent -@strong{28}. The representation for a compilation. See 10.1(2). +@strong{28}. The representation for a compilation. See 10.1(2). @end cartouche @noindent A compilation is represented by a sequence of files presented to the -compiler in a single invocation of the @file{gcc} command. +compiler in a single invocation of the @code{gcc} command. @sp 1 @cartouche @noindent @strong{29}. Any restrictions on compilations that contain multiple -compilation_units. See 10.1(4). +compilation_units. See 10.1(4). @end cartouche @noindent No single file can contain more than one compilation unit, but any @@ -5535,7 +5592,7 @@ compilation. @cartouche @noindent @strong{30}. The mechanisms for creating an environment and for adding -and replacing compilation units. See 10.1.4(3). +and replacing compilation units. See 10.1.4(3). @end cartouche @noindent See separate section on compilation model. @@ -5544,37 +5601,37 @@ See separate section on compilation model. @cartouche @noindent @strong{31}. The manner of explicitly assigning library units to a -partition. See 10.2(2). +partition. See 10.2(2). @end cartouche @noindent 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 +Manual section 10.2(2-6). In other words, the Ada units will be those that 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 +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 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 -z and -n respectively, and in this case a +provides the binder options @code{-z} and @code{-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 -the User Guide sections on Binding and Linking. +automatically). For full details on the use of these options, refer to +the @cite{GNAT User's Guide} sections on Binding and Linking. @sp 1 @cartouche @noindent @strong{32}. The implementation-defined means, if any, of specifying -which compilation units are needed by a given compilation unit. See +which compilation units are needed by a given compilation unit. See 10.2(2). @end cartouche @noindent The units needed by a given compilation unit are as defined in -the Ada Reference Manual section 10.2(2-6). There are no +the Ada Reference Manual section 10.2(2-6). There are no implementation-defined pragmas or other implementation-defined means for specifying needed units. @@ -5582,21 +5639,21 @@ means for specifying needed units. @cartouche @noindent @strong{33}. The manner of designating the main subprogram of a -partition. See 10.2(7). +partition. See 10.2(7). @end cartouche @noindent The main program is designated by providing the name of the -corresponding ali file as the input parameter to the binder. +corresponding @file{ALI} file as the input parameter to the binder. @sp 1 @cartouche @noindent -@strong{34}. The order of elaboration of @code{library_items}. See +@strong{34}. 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 95 Reference Manual. This still leaves some +chapter 10 of the Ada 95 Reference Manual. This still leaves some implementation dependent choices, which are resolved by first elaborating bodies as early as possible (i.e.@: in preference to specs where there is a choice), and second by evaluating the immediate with @@ -5608,31 +5665,31 @@ where a choice still remains. @cartouche @noindent @strong{35}. Parameter passing and function return for the main -subprogram. See 10.2(21). +subprogram. See 10.2(21). @end cartouche @noindent -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 +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. @sp 1 @cartouche @noindent -@strong{36}. The mechanisms for building and running partitions. See +@strong{36}. 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 +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 +programs consisting of multiple partitions. See the separate GLADE manual for details. @sp 1 @cartouche @noindent @strong{37}. The details of program execution, including program -termination. See 10.2(25). +termination. See 10.2(25). @end cartouche @noindent See separate section on compilation model. @@ -5641,17 +5698,17 @@ See separate section on compilation model. @cartouche @noindent @strong{38}. The semantics of any non-active partitions supported by the -implementation. See 10.2(28). +implementation. See 10.2(28). @end cartouche @noindent Passive partitions are supported on targets where shared memory is -provided by the operating system. See the GLADE reference manual for +provided by the operating system. See the GLADE reference manual for further details. @sp 1 @cartouche @noindent -@strong{39}. The information returned by @code{Exception_Message}. See +@strong{39}. The information returned by @code{Exception_Message}. See 11.4.1(10). @end cartouche @noindent @@ -5662,7 +5719,7 @@ been passed by the program. @cartouche @noindent @strong{40}. The result of @code{Exceptions.Exception_Name} for types -declared within an unnamed @code{block_statement}. See 11.4.1(12). +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}} @@ -5672,16 +5729,50 @@ where @var{nnn} is an integer. @cartouche @noindent @strong{41}. The information returned by -@code{Exception_Information}. See 11.4.1(13). +@code{Exception_Information}. See 11.4.1(13). @end cartouche @noindent -@code{Exception_Information} contains the expanded name of the exception -in upper case, and no other information. +@code{Exception_Information} returns a string in the following format: + +@smallexample +@emph{Exception_Name:} nnnnn +@emph{Message:} mmmmm +@emph{PID:} ppp +@emph{Call stack traceback locations:} +0xhhhh 0xhhhh 0xhhhh ... 0xhhh +@end smallexample + +@noindent +where + +@itemize @bullet +@item +@code{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 +@code{ppp} is the Process Id value as a decimal integer (this line is +present only if the Process Id is non-zero). Currently we are +not making use of this field. + +@item +The Call stack traceback locations line and the following values +are present only if at least one traceback location was recorded. +The values are given in C style format, with lower case letters +for a-f, and only as many digits present as are necessary. +@end itemize + +@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 @cartouche @noindent -@strong{42}. Implementation-defined check names. See 11.5(27). +@strong{42}. Implementation-defined check names. See 11.5(27). @end cartouche @noindent No implementation-defined check names are supported. @@ -5689,7 +5780,7 @@ No implementation-defined check names are supported. @sp 1 @cartouche @noindent -@strong{43}. The interpretation of each aspect of representation. See +@strong{43}. The interpretation of each aspect of representation. See 13.1(20). @end cartouche @noindent @@ -5698,7 +5789,7 @@ See separate section on data representations. @sp 1 @cartouche @noindent -@strong{44}. Any restrictions placed upon representation items. See +@strong{44}. Any restrictions placed upon representation items. See 13.1(20). @end cartouche @noindent @@ -5707,7 +5798,7 @@ See separate section on data representations. @sp 1 @cartouche @noindent -@strong{45}. The meaning of @code{Size} for indefinite subtypes. See +@strong{45}. The meaning of @code{Size} for indefinite subtypes. See 13.3(48). @end cartouche @noindent @@ -5718,7 +5809,7 @@ is the actual size. @sp 1 @cartouche @noindent -@strong{46}. The default external representation for a type tag. See +@strong{46}. The default external representation for a type tag. See 13.3(75). @end cartouche @noindent @@ -5729,7 +5820,7 @@ name of the type in upper case letters. @cartouche @noindent @strong{47}. What determines whether a compilation unit is the same in -two different partitions. See 13.3(76). +two different partitions. See 13.3(76). @end cartouche @noindent A compilation unit is the same in two different partitions if and only @@ -5738,7 +5829,7 @@ if it derives from the same source file. @sp 1 @cartouche @noindent -@strong{48}. Implementation-defined components. See 13.5.1(15). +@strong{48}. Implementation-defined components. See 13.5.1(15). @end cartouche @noindent The only implementation defined component is the tag for a tagged type, @@ -5748,18 +5839,18 @@ which contains a pointer to the dispatching table. @cartouche @noindent @strong{49}. If @code{Word_Size} = @code{Storage_Unit}, the default bit -ordering. See 13.5.3(5). +ordering. See 13.5.3(5). @end cartouche @noindent @code{Word_Size} (32) is not the same as @code{Storage_Unit} (8) for this -implementation, so no non-default bit ordering is supported. The default +implementation, so no non-default bit ordering is supported. The default bit ordering corresponds to the natural endianness of the target architecture. @sp 1 @cartouche @noindent @strong{50}. The contents of the visible part of package @code{System} -and its language-defined children. See 13.7(2). +and its language-defined children. See 13.7(2). @end cartouche @noindent See the definition of these packages in files @file{system.ads} and @@ -5770,7 +5861,7 @@ See the definition of these packages in files @file{system.ads} and @noindent @strong{51}. The contents of the visible part of package @code{System.Machine_Code}, and the meaning of -@code{code_statements}. See 13.8(7). +@code{code_statements}. See 13.8(7). @end cartouche @noindent See the definition and documentation in file @file{s-maccod.ads}. @@ -5778,12 +5869,12 @@ See the definition and documentation in file @file{s-maccod.ads}. @sp 1 @cartouche @noindent -@strong{52}. The effect of unchecked conversion. See 13.9(11). +@strong{52}. The effect of unchecked conversion. See 13.9(11). @end cartouche @noindent Unchecked conversion between types of the same size and 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 +to the other. If the types are of unequal sizes, then in the case of discrete types, a shorter source is first zero or sign extended as necessary, and a shorter target is simply truncated on the left. For all non-discrete types, the source is first copied if necessary @@ -5796,13 +5887,13 @@ target type. @cartouche @noindent @strong{53}. 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). +when @code{Storage_Pool} is not specified for the type. See 13.11(17). @end cartouche @noindent There are 3 different standard pools used by the compiler when @code{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 +@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 @@ -5812,18 +5903,18 @@ default pools used. @cartouche @noindent @strong{54}. Whether or not the implementation provides user-accessible -names for the standard pool type(s). See 13.11(17). +names for the standard pool type(s). See 13.11(17). @end cartouche @noindent See documentation in the sources of the run time mentioned in paragraph -@strong{53} . All these pools are accessible by means of @code{with}'ing +@strong{53} . All these pools are accessible by means of @code{with}'ing these units. @sp 1 @cartouche @noindent -@strong{55}. The meaning of @code{Storage_Size}. See 13.11(18). +@strong{55}. 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 @@ -5833,7 +5924,7 @@ stack space for a task. @sp 1 @cartouche @noindent -@strong{56}. Implementation-defined aspects of storage pools. See +@strong{56}. Implementation-defined aspects of storage pools. See 13.11(22). @end cartouche @noindent @@ -5844,12 +5935,12 @@ See documentation in the sources of the run time mentioned in paragraph @cartouche @noindent @strong{57}. The set of restrictions allowed in a pragma -@code{Restrictions}. See 13.12(7). +@code{Restrictions}. See 13.12(7). @end cartouche @noindent -All RM defined Restriction identifiers are implemented. The following -additional restriction identifiers are provided. There are two separate -lists of implementation dependent restriction identifiers. The first +All RM defined Restriction identifiers are implemented. The following +additional restriction identifiers are provided. There are two separate +lists of implementation dependent 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. @@ -5860,17 +5951,17 @@ then all compilation units in the partition must obey the restriction. @findex Boolean_Entry_Barriers This restriction ensures at compile time that barriers in entry declarations for protected types are restricted to references to simple boolean variables -defined in the private part of the protected type. No other form of entry -barriers is permitted. This is one of the restrictions of the Ravenscar -profile for limited tasking (see also pragma Ravenscar). +defined in the private part of the protected type. No other form of entry +barriers is permitted. This is one of the restrictions of the Ravenscar +profile for limited tasking (see also pragma @code{Ravenscar}). @item Max_Entry_Queue_Depth => Expr @findex Max_Entry_Queue_Depth 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. This restriction is not -checked at compile time. A program execution is erroneous if an attempt +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 more than the specified number of tasks on such an entry. @item No_Calendar @@ -5881,7 +5972,7 @@ explicit dependence on the package @code{Ada.Calendar}. @item No_Dynamic_Interrupts @findex No_Dynamic_Interrupts This restriction ensures at compile time that there is no attempt to -dynamically associate interrupts. Only static association is allowed. +dynamically associate interrupts. Only static association is allowed. @item No_Enumeration_Maps @findex No_Enumeration_Maps @@ -5892,7 +5983,7 @@ to enumeration types). @item No_Entry_Calls_In_Elaboration_Code @findex No_Entry_Calls_In_Elaboration_Code 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 +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. @@ -5906,7 +5997,7 @@ exception handlers. 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 -conditional. The details and use of this restriction are described in +conditional. The details and use of this restriction are described in more detail in the High Integrity product documentation. @item No_Implicit_Loops @@ -5915,8 +6006,8 @@ This restriction ensures that the generated code does not contain any implicit @code{for} loops, either by modifying the generated code where possible, or by rejecting any construct that would otherwise generate an implicit -@code{for} loop. The details and use of this restriction are described in -more detail in the GNORT Reference Manual. +@code{for} loop. The details and use of this restriction are described in +more detail in the High Integrity product documentation. @item No_Local_Protected_Objects @findex No_Local_Protected_Objects @@ -5928,17 +6019,26 @@ only declared at the library level. This restriction ensures at compile time that there are no allocator expressions that attempt to allocate protected objects. +@item No_Secondary_Stack +@findex No_Secondary_Stack +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. +The details and use of this restriction are described in +more detail in the High Integrity product documentation. + @item No_Select_Statements @findex No_Select_Statements This restriction ensures at compile time no select statements of any kind are permitted, that is the keyword @code{select} may not appear. This is one of the restrictions of the Ravenscar -profile for limited tasking (see also pragma Ravenscar). +profile for limited tasking (see also pragma @code{Ravenscar}). @item No_Standard_Storage_Pools @findex No_Standard_Storage_Pools This restriction ensures at compile time that no access types -use the standard default storage pool. Any access type declared must +use the standard default storage pool. Any access type declared must have an explicit Storage_Pool attribute defined specifying a user-defined storage pool. @@ -5957,6 +6057,13 @@ explicit dependencies on the package @code{Ada.Task_Attributes}. This restriction ensures at compile time that no terminate alternatives appear in any task body. +@item No_Tasking +@findex No_Tasking +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 and cause an error message +to be output either by the compiler or binder. + @item No_Wide_Characters @findex No_Wide_Characters This restriction ensures at compile time that no uses of the types @@ -5990,15 +6097,15 @@ other compilation units in the partition. @item No_Elaboration_Code @findex No_Elaboration_Code 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 Preelaborate. There are cases in which pragma Preelaborate +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 to initialize a large array to all zeroes), and there are cases of units which do not meet -the requirements for pragma Preelaborate, but for which no elaboration -code is generated. Generally, it is the case that preelaborable units +the requirements for pragma @code{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, and exception declarations (which -generate calls to a run-time registry procedure). Note that this restriction +generate calls to a run-time registry procedure). Note that this restriction is enforced on a unit by unit basis, it need not be obeyed consistently throughout a partition. @@ -6006,27 +6113,27 @@ throughout a partition. @findex No_Entry_Queue 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 +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. @item No_Implementation_Attributes @findex No_Implementation_Attributes This restriction checks at compile time that no GNAT-defined attributes -are present. With this restriction, the only attributes that can be used +are present. With this restriction, the only attributes that can be used are those defined in the Ada 95 Reference Manual. @item No_Implementation_Pragmas @findex No_Implementation_Pragmas This restriction checks at compile time that no GNAT-defined pragmas -are present. With this restriction, the only pragmas that can be used +are present. With this restriction, the only pragmas that can be used are those defined in the Ada 95 Reference Manual. @item No_Implementation_Restrictions @findex No_Implementation_Restrictions This restriction checks at compile time that no GNAT-defined restriction identifiers (other than @code{No_Implementation_Restrictions} itself) -are present. With this restriction, the only other restriction identifiers +are present. With this restriction, the only other restriction identifiers that can be used are those defined in the Ada 95 Reference Manual. @end table @@ -6035,11 +6142,11 @@ that can be used are those defined in the Ada 95 Reference Manual. @cartouche @noindent @strong{58}. The consequences of violating limitations on -@code{Restrictions} pragmas. See 13.12(9). +@code{Restrictions} pragmas. See 13.12(9). @end cartouche @noindent Restrictions that can be checked at compile time result in illegalities -if violated. Currently there are no other consequences of violating +if violated. Currently there are no other consequences of violating restrictions. @sp 1 @@ -6047,7 +6154,7 @@ restrictions. @noindent @strong{59}. The representation used by the @code{Read} and @code{Write} attributes of elementary types in terms of stream -elements. See 13.13.2(9). +elements. See 13.13.2(9). @end cartouche @noindent The representation is the in-memory representation of the base type of @@ -6058,7 +6165,7 @@ the type, using the number of bits corresponding to the @cartouche @noindent @strong{60}. The names and characteristics of the numeric subtypes -declared in the visible part of package @code{Standard}. See A.1(3). +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. @@ -6067,18 +6174,18 @@ See items describing the integer and floating-point types supported. @cartouche @noindent @strong{61}. The accuracy actually achieved by the elementary -functions. See A.5.1(1). +functions. See A.5.1(1). @end cartouche @noindent The elementary functions correspond to the functions available in the C -library. Only fast math mode is implemented. +library. Only fast math mode is implemented. @sp 1 @cartouche @noindent @strong{62}. 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). +@code{Float_Type'Signed_Zeros} is @code{True}. See A.5.1(46). @end cartouche @noindent The sign of zeroes follows the requirements of the IEEE 754 standard on @@ -6088,7 +6195,7 @@ floating-point. @cartouche @noindent @strong{63}. The value of -@code{Numerics.Float_Random.Max_Image_Width}. See A.5.2(27). +@code{Numerics.Float_Random.Max_Image_Width}. See A.5.2(27). @end cartouche @noindent Maximum image width is 649, see library file @file{a-numran.ads}. @@ -6097,7 +6204,7 @@ Maximum image width is 649, see library file @file{a-numran.ads}. @cartouche @noindent @strong{64}. The value of -@code{Numerics.Discrete_Random.Max_Image_Width}. See A.5.2(27). +@code{Numerics.Discrete_Random.Max_Image_Width}. See A.5.2(27). @end cartouche @noindent Maximum image width is 80, see library file @file{a-nudira.ads}. @@ -6105,7 +6212,7 @@ Maximum image width is 80, see library file @file{a-nudira.ads}. @sp 1 @cartouche @noindent -@strong{65}. The algorithms for random number generation. See +@strong{65}. The algorithms for random number generation. See A.5.2(32). @end cartouche @noindent @@ -6116,7 +6223,7 @@ The algorithm is documented in the source files @file{a-numran.ads} and @cartouche @noindent @strong{66}. The string representation of a random number generator's -state. See A.5.2(38). +state. See A.5.2(38). @end cartouche @noindent See the documentation contained in the file @file{a-numran.adb}. @@ -6126,7 +6233,7 @@ See the documentation contained in the file @file{a-numran.adb}. @noindent @strong{67}. 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). +random number sequences. See A.5.2(45). @end cartouche @noindent The minimum period between reset calls to guarantee distinct series of @@ -6138,7 +6245,7 @@ random numbers is one microsecond. @strong{68}. 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). +Annex is not supported. See A.5.3(72). @end cartouche @noindent See the source file @file{ttypef.ads} for the values of all numeric @@ -6148,7 +6255,7 @@ attributes. @cartouche @noindent @strong{69}. Any implementation-defined characteristics of the -input-output packages. See A.7(14). +input-output packages. See A.7(14). @end cartouche @noindent There are no special implementation defined characteristics for these @@ -6157,7 +6264,7 @@ packages. @sp 1 @cartouche @noindent -@strong{70}. The value of @code{Buffer_Size} in @code{Storage_IO}. See +@strong{70}. The value of @code{Buffer_Size} in @code{Storage_IO}. See A.9(10). @end cartouche @noindent @@ -6173,12 +6280,12 @@ standard error See A.10(5). @end cartouche @noindent 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 @file{i-cstrea.ads} for further details. @sp 1 @cartouche @noindent -@strong{72}. The accuracy of the value produced by @code{Put}. See +@strong{72}. The accuracy of the value produced by @code{Put}. See A.10.9(36). @end cartouche @noindent @@ -6190,7 +6297,7 @@ significant digit positions. @cartouche @noindent @strong{73}. The meaning of @code{Argument_Count}, @code{Argument}, and -@code{Command_Name}. See A.15(1). +@code{Command_Name}. See A.15(1). @end cartouche @noindent These are mapped onto the @code{argv} and @code{argc} parameters of the @@ -6199,7 +6306,7 @@ main program in the natural manner. @sp 1 @cartouche @noindent -@strong{74}. Implementation-defined convention names. See B.1(11). +@strong{74}. Implementation-defined convention names. See B.1(11). @end cartouche @noindent The following convention names are supported @@ -6207,28 +6314,23 @@ The following convention names are supported @table @code @item Ada Ada -@item Asm -Assembly language @item Assembler Assembly language +@item Asm +Synonym for Assembler +@item Assembly +Synonym for Assembler @item C C @item C_Pass_By_Copy -Treated like C, except for record types +Allowed only for record types, like C, but also notes that record +is to be passed by copy rather than reference. @item COBOL COBOL @item CPP C++ @item Default Treated the same as C -@item DLL -DLL (used for Windows implementations only) is handled like the Stdcall -convention. This convention is used to access variables and functions -(with Stdcall convention) in a DLL@. -@item Win32 -Win32 (used for Windows implementations only) is handled like the Stdcall -convention. This convention is used to access variables and functions -(with Stdcall convention) in a DLL@. @item External Treated the same as C @item Fortran @@ -6237,28 +6339,32 @@ Fortran For support of pragma @code{Import} with convention Intrinsic, see separate section on Intrinsic Subprograms. @item Stdcall -Stdcall (used for Windows implementations only). This convention correspond +Stdcall (used for Windows implementations only). This convention correspond to the WINAPI (previously called Pascal convention) C/C++ convention under -Windows. A function with this convention clean the stack before exit. +Windows. A function with this convention cleans the stack before exit. +@item DLL +Synonym for Stdcall +@item Win32 +Synonym for Stdcall @item Stubbed 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 +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 -be present at all. This convention is useful during development for the +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 -except for VMS, use of such other names results in a warning. In VMS +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 @cartouche @noindent -@strong{75}. The meaning of link names. See B.1(36). +@strong{75}. The meaning of link names. See B.1(36). @end cartouche @noindent Link names are the actual names used by the linker. @@ -6267,7 +6373,7 @@ Link names are the actual names used by the linker. @cartouche @noindent @strong{76}. The manner of choosing link names when neither the link -name nor the address of an imported or exported entity is specified. See +name nor the address of an imported or exported entity is specified. See B.1(36). @end cartouche @noindent @@ -6278,7 +6384,7 @@ letters. @sp 1 @cartouche @noindent -@strong{77}. The effect of pragma @code{Linker_Options}. See B.1(37). +@strong{77}. 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 @@ -6290,26 +6396,17 @@ pragma Linker_Options ("-labc" & ASCII.Nul & "-ldef"); @end smallexample @noindent -causes two separate arguments "-labc" and "-ldef" to be passed to the -linker with a guarantee that the order is preserved (no such guarantee -exists for the use of separate Linker_Options pragmas). - -In addition, GNAT allow multiple arguments to @code{Linker_Options} -with exactly the same meaning, so the above pragma could also be -written as: - -@smallexample -pragma Linker_Options ("-labc", "-ldef"); -@end smallexample - -@noindent -The above multiple argument form is a GNAT extension. +causes two separate arguments @code{-labc} and @code{-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 fo a body always appear before the options +from the corresponding package spec. @sp 1 @cartouche @noindent @strong{78}. The contents of the visible part of package -@code{Interfaces} and its language-defined descendants. See B.2(1). +@code{Interfaces} and its language-defined descendants. See B.2(1). @end cartouche @noindent See files with prefix @file{i-} in the distributed library. @@ -6318,8 +6415,8 @@ See files with prefix @file{i-} in the distributed library. @cartouche @noindent @strong{79}. Implementation-defined children of package -@code{Interfaces}. The contents of the visible part of package -@code{Interfaces}. See B.2(11). +@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. @@ -6331,7 +6428,7 @@ See files with prefix @file{i-} in the distributed library. @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). +@code{Interfaces.COBOL}. See B.4(50). @end cartouche @noindent @table @code @@ -6354,7 +6451,7 @@ For initialization, see the file @file{i-cobol.ads} in the distributed library. @sp 1 @cartouche @noindent -@strong{81}. Support for access to machine instructions. See C.1(1). +@strong{81}. 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. @@ -6363,7 +6460,7 @@ See documentation in file @file{s-maccod.ads} in the distributed library. @cartouche @noindent @strong{82}. Implementation-defined aspects of access to machine -operations. See C.1(9). +operations. See C.1(9). @end cartouche @noindent See documentation in file @file{s-maccod.ads} in the distributed library. @@ -6371,10 +6468,10 @@ See documentation in file @file{s-maccod.ads} in the distributed library. @sp 1 @cartouche @noindent -@strong{83}. Implementation-defined aspects of interrupts. See C.3(2). +@strong{83}. Implementation-defined aspects of interrupts. See C.3(2). @end cartouche @noindent -Interrupts are mapped to signals or conditions as appropriate. See +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 on the interrupts supported on a particular target. @@ -6382,7 +6479,7 @@ on the interrupts supported on a particular target. @sp 1 @cartouche @noindent -@strong{84}. Implementation-defined aspects of pre-elaboration. See +@strong{84}. Implementation-defined aspects of pre-elaboration. See C.4(13). @end cartouche @noindent @@ -6392,11 +6489,11 @@ except under control of the debugger. @sp 1 @cartouche @noindent -@strong{85}. The semantics of pragma @code{Discard_Names}. See C.5(7). +@strong{85}. The semantics of pragma @code{Discard_Names}. See C.5(7). @end cartouche @noindent Pragma @code{Discard_Names} causes names of enumeration literals to -be suppressed. In the presence of this pragma, the Image attribute +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. @@ -6404,7 +6501,7 @@ Pos values. @cartouche @noindent @strong{86}. The result of the @code{Task_Identification.Image} -attribute. See C.7.1(7). +attribute. See C.7.1(7). @end cartouche @noindent The result of this attribute is an 8-digit hexadecimal string @@ -6414,7 +6511,7 @@ representing the virtual address of the task control block. @cartouche @noindent @strong{87}. The value of @code{Current_Task} when in a protected entry -or interrupt handler. See C.7.1(17). +or interrupt handler. See C.7.1(17). @end cartouche @noindent Protected entries or interrupt handlers can be executed by any @@ -6424,7 +6521,7 @@ convenient thread, so the value of @code{Current_Task} is undefined. @cartouche @noindent @strong{88}. The effect of calling @code{Current_Task} from an entry -body or interrupt handler. See C.7.1(19). +body or interrupt handler. See C.7.1(19). @end cartouche @noindent The effect of calling @code{Current_Task} from an entry body or @@ -6435,7 +6532,7 @@ executing the code. @cartouche @noindent @strong{89}. Implementation-defined aspects of -@code{Task_Attributes}. See C.7.2(19). +@code{Task_Attributes}. See C.7.2(19). @end cartouche @noindent There are no implementation-defined aspects of @code{Task_Attributes}. @@ -6443,14 +6540,14 @@ There are no implementation-defined aspects of @code{Task_Attributes}. @sp 1 @cartouche @noindent -@strong{90}. Values of all @code{Metrics}. See D(2). +@strong{90}. Values of all @code{Metrics}. See D(2). @end cartouche @noindent The metrics information for GNAT depends on the performance of the -underlying operating system. The sources of the run-time for tasking +underlying operating system. The sources of the run-time for tasking implementation, together with the output from @code{-gnatG} can be used to determine the exact sequence of operating systems calls made -to implement various tasking constructs. Together with appropriate +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. @@ -6459,7 +6556,7 @@ the required metrics. @cartouche @noindent @strong{91}. The declarations of @code{Any_Priority} and -@code{Priority}. See D.1(11). +@code{Priority}. See D.1(11). @end cartouche @noindent See declarations in file @file{system.ads}. @@ -6467,7 +6564,7 @@ See declarations in file @file{system.ads}. @sp 1 @cartouche @noindent -@strong{92}. Implementation-defined execution resources. See D.1(15). +@strong{92}. Implementation-defined execution resources. See D.1(15). @end cartouche @noindent There are no implementation-defined execution resources. @@ -6476,7 +6573,7 @@ There are no implementation-defined execution resources. @cartouche @noindent @strong{93}. Whether, on a multiprocessor, a task that is waiting for -access to a protected object keeps its processor busy. See D.2.1(3). +access to a protected object keeps its processor busy. See D.2.1(3). @end cartouche @noindent On a multi-processor, a task that is waiting for access to a protected @@ -6486,7 +6583,7 @@ object does not keep its processor busy. @cartouche @noindent @strong{94}. The affect of implementation defined execution resources -on task dispatching. See D.2.1(9). +on task dispatching. See D.2.1(9). @end cartouche @noindent @c SGI info @@ -6494,7 +6591,7 @@ on task dispatching. See D.2.1(9). Tasks map to IRIX threads, and the dispatching policy is as defined by the IRIX implementation of threads. @end ignore -Tasks map to threads in the threads package used by GNAT@. Where possible +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. @@ -6502,7 +6599,7 @@ underlying operating system. @cartouche @noindent @strong{95}. Implementation-defined @code{policy_identifiers} allowed -in a pragma @code{Task_Dispatching_Policy}. See D.2.2(3). +in a pragma @code{Task_Dispatching_Policy}. See D.2.2(3). @end cartouche @noindent There are no implementation-defined policy-identifiers allowed in this @@ -6511,7 +6608,7 @@ pragma. @sp 1 @cartouche @noindent -@strong{96}. Implementation-defined aspects of priority inversion. See +@strong{96}. Implementation-defined aspects of priority inversion. See D.2.2(16). @end cartouche @noindent @@ -6521,7 +6618,7 @@ of delay expirations for lower priority tasks. @sp 1 @cartouche @noindent -@strong{97}. Implementation defined task dispatching. See D.2.2(18). +@strong{97}. Implementation defined task dispatching. See D.2.2(18). @end cartouche @noindent @c SGI info: @@ -6535,11 +6632,11 @@ The policy is the same as that of the underlying threads implementation. @cartouche @noindent @strong{98}. Implementation-defined @code{policy_identifiers} allowed -in a pragma @code{Locking_Policy}. See D.3(4). +in a pragma @code{Locking_Policy}. See D.3(4). @end cartouche @noindent The only implementation defined policy permitted in GNAT is -@code{Inheritance_Locking}. On targets that support this policy, locking +@code{Inheritance_Locking}. On targets that support this 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. @@ -6547,7 +6644,7 @@ requesting the lock. @sp 1 @cartouche @noindent -@strong{99}. Default ceiling priorities. See D.3(10). +@strong{99}. Default ceiling priorities. See D.3(10). @end cartouche @noindent The ceiling priority of protected objects of the type @@ -6558,7 +6655,7 @@ Reference Manual D.3(10), @cartouche @noindent @strong{100}. The ceiling of any protected object used internally by -the implementation. See D.3(16). +the implementation. See D.3(16). @end cartouche @noindent The ceiling priority of internal protected objects is @@ -6567,7 +6664,7 @@ The ceiling priority of internal protected objects is @sp 1 @cartouche @noindent -@strong{101}. Implementation-defined queuing policies. See D.4(1). +@strong{101}. Implementation-defined queuing policies. See D.4(1). @end cartouche @noindent There are no implementation-defined queueing policies. @@ -6577,7 +6674,7 @@ There are no implementation-defined queueing policies. @noindent @strong{102}. 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). +specified for a single processor. See D.6(3). @end cartouche @noindent The semantics for abort on a multi-processor is the same as on a single @@ -6587,7 +6684,7 @@ processor, there are no further delays. @cartouche @noindent @strong{103}. Any operations that implicitly require heap storage -allocation. See D.7(8). +allocation. See D.7(8). @end cartouche @noindent The only operation that implicitly requires heap storage allocation is @@ -6597,7 +6694,7 @@ task creation. @cartouche @noindent @strong{104}. Implementation-defined aspects of pragma -@code{Restrictions}. See D.7(20). +@code{Restrictions}. See D.7(20). @end cartouche @noindent There are no such implementation-defined aspects. @@ -6606,7 +6703,7 @@ There are no such implementation-defined aspects. @cartouche @noindent @strong{105}. Implementation-defined aspects of package -@code{Real_Time}. See D.8(17). +@code{Real_Time}. See D.8(17). @end cartouche @noindent There are no implementation defined aspects of package @code{Real_Time}. @@ -6615,7 +6712,7 @@ There are no implementation defined aspects of package @code{Real_Time}. @cartouche @noindent @strong{106}. Implementation-defined aspects of -@code{delay_statements}. See D.9(8). +@code{delay_statements}. See D.9(8). @end cartouche @noindent Any difference greater than one microsecond will cause the task to be @@ -6625,27 +6722,27 @@ delayed (see D.9(7)). @cartouche @noindent @strong{107}. The upper bound on the duration of interrupt blocking -caused by the implementation. See D.12(5). +caused by the implementation. See D.12(5). @end cartouche @noindent -The upper bound is determined by the underlying operating system. In +The upper bound is determined by the underlying operating system. In no cases is it more than 10 milliseconds. @sp 1 @cartouche @noindent @strong{108}. The means for creating and executing distributed -programs. See E(5). +programs. See E(5). @end cartouche @noindent The GLADE package provides a utility GNATDIST for creating and executing -distributed programs. See the GLADE reference manual for further details. +distributed programs. See the GLADE reference manual for further details. @sp 1 @cartouche @noindent @strong{109}. Any events that can result in a partition becoming -inaccessible. See E.1(7). +inaccessible. See E.1(7). @end cartouche @noindent See the GLADE reference manual for full details on such events. @@ -6654,7 +6751,7 @@ See the GLADE reference manual for full details on such events. @cartouche @noindent @strong{110}. The scheduling policies, treatment of priorities, and -management of shared resources between partitions in certain cases. See +management of shared resources between partitions in certain cases. See E.1(11). @end cartouche @noindent @@ -6665,12 +6762,12 @@ multi-partition execution. @cartouche @noindent @strong{111}. Events that cause the version of a compilation unit to -change. See E.3(5). +change. See E.3(5). @end cartouche @noindent 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 +to change. No other actions cause the version number to change. All changes are significant except those which affect only layout, capitalization or comments. @@ -6678,7 +6775,7 @@ comments. @cartouche @noindent @strong{112}. Whether the execution of the remote subprogram is -immediately aborted as a result of cancellation. See E.4(13). +immediately aborted as a result of cancellation. See E.4(13). @end cartouche @noindent See the GLADE reference manual for details on the effect of abort in @@ -6687,7 +6784,7 @@ a distributed application. @sp 1 @cartouche @noindent -@strong{113}. Implementation-defined aspects of the PCS@. See E.5(25). +@strong{113}. Implementation-defined aspects of the PCS@. See E.5(25). @end cartouche @noindent See the GLADE reference manual for a full description of all implementation @@ -6696,7 +6793,7 @@ defined aspects of the PCS@. @sp 1 @cartouche @noindent -@strong{114}. Implementation-defined interfaces in the PCS@. See +@strong{114}. Implementation-defined interfaces in the PCS@. See E.5(26). @end cartouche @noindent @@ -6707,7 +6804,7 @@ implementation defined interfaces. @cartouche @noindent @strong{115}. The values of named numbers in the package -@code{Decimal}. See F.2(7). +@code{Decimal}. See F.2(7). @end cartouche @noindent @table @code @@ -6727,7 +6824,7 @@ implementation defined interfaces. @cartouche @noindent @strong{116}. The value of @code{Max_Picture_Length} in the package -@code{Text_IO.Editing}. See F.3.3(16). +@code{Text_IO.Editing}. See F.3.3(16). @end cartouche @noindent 64 @@ -6736,7 +6833,7 @@ implementation defined interfaces. @cartouche @noindent @strong{117}. The value of @code{Max_Picture_Length} in the package -@code{Wide_Text_IO.Editing}. See F.3.4(5). +@code{Wide_Text_IO.Editing}. See F.3.4(5). @end cartouche @noindent 64 @@ -6745,18 +6842,18 @@ implementation defined interfaces. @cartouche @noindent @strong{118}. The accuracy actually achieved by the complex elementary -functions and by other complex arithmetic operations. See G.1(1). +functions and by other complex arithmetic operations. See G.1(1). @end cartouche @noindent Standard library functions are used for the complex arithmetic -operations. Only fast math mode is currently supported. +operations. Only fast math mode is currently supported. @sp 1 @cartouche @noindent @strong{119}. 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). +@code{Real'Signed_Zeros} is True. See G.1.1(53). @end cartouche @noindent The signs of zero values are as recommended by the relevant @@ -6768,7 +6865,7 @@ implementation advice. @strong{120}. 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). +@code{Real'Signed_Zeros} is @code{True}. See G.1.2(45). @end cartouche @noindent The signs of zero values are as recommended by the relevant @@ -6778,17 +6875,17 @@ implementation advice. @cartouche @noindent @strong{121}. Whether the strict mode or the relaxed mode is the -default. See G.2(2). +default. See G.2(2). @end cartouche @noindent -The strict mode is the default. There is no separate relaxed mode. GNAT +The strict mode is the default. There is no separate relaxed mode. GNAT provides a highly efficient implementation of strict mode. @sp 1 @cartouche @noindent @strong{122}. The result interval in certain cases of fixed-to-float -conversion. See G.2.1(10). +conversion. See G.2.1(10). @end cartouche @noindent For cases where the result interval is implementation dependent, the @@ -6800,7 +6897,7 @@ floating-point format. @noindent @strong{123}. 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). +result type is @code{False}. See G.2.1(13). @end cartouche @noindent Infinite and Nan values are produced as dictated by the IEEE @@ -6811,7 +6908,7 @@ floating-point standard. @noindent @strong{124}. 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). +as multiplication by a reciprocal. See G.2.1(16). @end cartouche @noindent Not relevant, division is IEEE exact. @@ -6820,12 +6917,12 @@ Not relevant, division is IEEE exact. @cartouche @noindent @strong{125}. The definition of close result set, which determines the -accuracy of certain fixed point multiplications and divisions. See +accuracy of certain fixed point multiplications and divisions. See G.2.3(5). @end cartouche @noindent Operations in the close result set are performed using IEEE long format -floating-point arithmetic. The input operands are converted to +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. @@ -6834,7 +6931,7 @@ is converted to the target type. @noindent @strong{126}. Conditions on a @code{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). +perfect result set. See G.2.3(22). @end cartouche @noindent The result is only defined to be in the perfect result set if the result @@ -6846,7 +6943,7 @@ representable in 64-bits. @noindent @strong{127}. 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). +result type is @code{False}. See G.2.3(27). @end cartouche @noindent Not relevant, @code{Machine_Overflows} is @code{True} for fixed-point @@ -6857,7 +6954,7 @@ types. @noindent @strong{128}. 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). +result type is @code{False}. See G.2.4(4). @end cartouche @noindent IEEE infinite and Nan values are produced as appropriate. @@ -6868,7 +6965,7 @@ IEEE infinite and Nan values are produced as appropriate. @strong{129}. 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). +error bound. See G.2.4(10). @end cartouche @noindent Information on this subject is not yet available. @@ -6877,7 +6974,7 @@ Information on this subject is not yet available. @cartouche @noindent @strong{130}. The accuracy of certain elementary functions for -parameters beyond the angle threshold. See G.2.4(10). +parameters beyond the angle threshold. See G.2.4(10). @end cartouche @noindent Information on this subject is not yet available. @@ -6888,7 +6985,7 @@ Information on this subject is not yet available. @strong{131}. 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). +@code{False}. See G.2.6(5). @end cartouche @noindent IEEE infinite and Nan values are produced as appropriate. @@ -6898,7 +6995,7 @@ IEEE infinite and Nan values are produced as appropriate. @noindent @strong{132}. 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). +thereof) beyond the angle threshold. See G.2.6(8). @end cartouche @noindent Information on those subjects is not yet available. @@ -6907,7 +7004,7 @@ Information on those subjects is not yet available. @cartouche @noindent @strong{133}. Information regarding bounded errors and erroneous -execution. See H.2(1). +execution. See H.2(1). @end cartouche @noindent Information on this subject is not yet available. @@ -6916,7 +7013,7 @@ Information on this subject is not yet available. @cartouche @noindent @strong{134}. Implementation-defined aspects of pragma -@code{Inspection_Point}. See H.3.2(8). +@code{Inspection_Point}. See H.3.2(8). @end cartouche @noindent Pragma @code{Inspection_Point} ensures that the variable is live and can @@ -6926,17 +7023,17 @@ be examined by the debugger at the inspection point. @cartouche @noindent @strong{135}. Implementation-defined aspects of pragma -@code{Restrictions}. See H.4(25). +@code{Restrictions}. See H.4(25). @end cartouche @noindent -There are no implementation-defined aspects of pragma @code{Restrictions}. The +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}. +generated code. Checks must suppressed by use of pragma @code{Suppress}. @sp 1 @cartouche @noindent -@strong{136}. Any restrictions on pragma @code{Restrictions}. See +@strong{136}. Any restrictions on pragma @code{Restrictions}. See H.4(27). @end cartouche @noindent @@ -6971,10 +7068,10 @@ GNAT allows a user application program to write the declaration: @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 +subprogram meets the requirements. This chapter describes the set of implemented intrinsic subprograms, and the requirements on parameter profiles. Note that no body is supplied; as with other uses of pragma Import, the -body is supplied elsewhere (in this case by the compiler itself). Note +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. @@ -6983,12 +7080,15 @@ Ada standard does not require Ada compilers to implement this feature. @cindex Intrinsic operator @noindent -All predefined operators can be used in @code{pragma Import (Intrinsic,..)} -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. You can use an intrinsic -operator declaration as in the following example: +All the predefined numeric operators in package Standard +in @code{pragma Import (Intrinsic,..)} +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}. +You can use an intrinsic operator declaration as in the following example: @smallexample type Int1 is new Integer; @@ -7000,15 +7100,17 @@ operator declaration as in the following example: @end smallexample @noindent -This declaration would permit "mixed mode" arithmetic on items -of the differing types Int1 and Int2. +This declaration would permit ``mixed mode'' arithmetic on items +of the differing types @code{Int1} and @code{Int2}. +It is also possible to specify such operators for private types, if the +full views are appropriate arithmetic types. @node Enclosing_Entity @section Enclosing_Entity @cindex Enclosing_Entity @noindent This intrinsic subprogram is used in the implementation of the -library routine @code{GNAT.Source_Info}. The only useful use of the +library routine @code{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 @@ -7019,7 +7121,7 @@ the current subprogram, package, task, entry, or protected subprogram. @cindex Exception_Information' @noindent This intrinsic subprogram is used in the implementation of the -library routine @code{GNAT.Current_Exception}. The only useful +library routine @code{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 @@ -7030,7 +7132,7 @@ the exception information associated with the current exception. @cindex Exception_Message @noindent This intrinsic subprogram is used in the implementation of the -library routine @code{GNAT.Current_Exception}. The only useful +library routine @code{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 @@ -7041,7 +7143,7 @@ the message associated with the current exception. @cindex Exception_Name @noindent This intrinsic subprogram is used in the implementation of the -library routine @code{GNAT.Current_Exception}. The only useful +library routine @code{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 @@ -7052,7 +7154,7 @@ the name of the current exception. @cindex File @noindent This intrinsic subprogram is used in the implementation of the -library routine @code{GNAT.Source_Info}. The only useful use of the +library routine @code{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 @@ -7063,7 +7165,7 @@ file. @cindex Line @noindent This intrinsic subprogram is used in the implementation of the -library routine @code{GNAT.Source_Info}. The only useful use of the +library routine @code{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 @@ -7074,7 +7176,7 @@ source line. @cindex Rotate_Left @noindent In standard Ada 95, the @code{Rotate_Left} function is available only -for the predefined modular types in package @code{Interfaces}. However, in +for the predefined modular types in package @code{Interfaces}. However, in GNAT it is possible to define a Rotate_Left function for a user defined modular type or any signed integer type as in this example: @@ -7087,11 +7189,11 @@ defined modular type or any signed integer type as in this example: @noindent The requirements are that the profile be exactly as in the example -above. The only modifications allowed are in the formal parameter +above. The only modifications allowed are in the formal parameter names, and in the type of @code{Value} and the return type, which must be the same, and must be either a signed integer type, or a modular integer type with a binary modulus, and the size must -be 8. 16, 32 or 64 bits. +be 8. 16, 32 or 64 bits. @node Rotate_Right @section Rotate_Right @@ -7130,7 +7232,7 @@ above for @code{Rotate_Left}. @cindex Source_Location @noindent This intrinsic subprogram is used in the implementation of the -library routine @code{GNAT.Source_Info}. The only useful use of the +library routine @code{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 @@ -7166,10 +7268,10 @@ source file location. This section describes the representation clauses accepted by GNAT, and their effect on the representation of corresponding data objects. -GNAT fully implements Annex C (Systems Programming). This means that all +GNAT fully implements Annex C (Systems Programming). This means that all the implementation advice sections in chapter 13 are fully implemented. However, these sections only require a minimal level of support for -representation clauses. GNAT provides much more extensive capabilities, +representation clauses. GNAT provides much more extensive capabilities, and this section describes the additional capabilities provided. @node Alignment Clauses @@ -7178,7 +7280,7 @@ and this section describes the additional capabilities provided. @noindent GNAT requires that all alignment clauses specify a power of 2, and all -default alignments are always a power of 2. The default alignment +default alignments are always a power of 2. The default alignment values are as follows: @itemize @bullet @@ -7193,34 +7295,51 @@ aligned. @item 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 +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 +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 31 bits will have an object size of four bytes, and an alignment of 4. @item 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 Pack is -used and all fields are packable (see separate section on pragma Pack), +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} is +used and all fields are packable (see separate section on pragma @code{Pack}), then the resulting alignment is 1. +A special case is when the size of the record is given explicitly, or a +full record representation clause is given, and the size of the record +is 2, 4, or 8 bytes. In this case, an alignment is chosen to match the +size of the record. For example, if we have: + +@smallexample + type Small is record + A, B : Character; + end record; +@end smallexample + +@noindent +then the default alignment of the record type @code{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 +strict alignment. + @end itemize @noindent An alignment clause may always specify a larger alignment than the default value, up to some maximum value dependent on the target (obtainable by using the -attribute reference System'Maximum_Alignment). The only case in which +attribute reference System'Maximum_Alignment). The only case in which it is permissible to specify a smaller alignment than the default value is in the case of a record for which a record representation clause is -given. In this case, packable fields for which a component clause is +given. In this case, packable fields for which a component clause is given still result in a default alignment corresponding to the original type, but this may be overridden, since these components in fact only -require an alignment of one byte. For example, given +require an alignment of one byte. For example, given @smallexample type v is record @@ -7246,10 +7365,10 @@ alignment of the record to a smaller value. @cindex Size Clause @noindent -The default size of types is as specified in the reference manual. For +The default size of types is as specified in the reference manual. For objects, GNAT will generally increase the type size so that the object size is a multiple of storage units, and also a multiple of the -alignment. For example +alignment. For example @smallexample type Smallint is range 1 .. 6; @@ -7265,7 +7384,7 @@ In this example, @code{Smallint} has a size of 3, as specified by the RM rules, but objects of this type will have a size of 8, since objects by default occupy an integral number -of storage units. On some targets, notably older +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. @@ -7273,7 +7392,7 @@ the inability of the hardware to do byte load/stores. Similarly, the size of type @code{Rec} is 40 bits, 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. The reason for this decision, which is +of the alignment. The reason for this decision, which is in accordance with the specific note in RM 13.3(43): @smallexample @@ -7285,7 +7404,7 @@ Alignment (if the Alignment is nonzero). @noindent An explicit size clause may be used to override the default size by -increasing it. For example, if we have: +increasing it. For example, if we have: @smallexample type My_Boolean is new Boolean; @@ -7293,20 +7412,20 @@ increasing it. For example, if we have: @end smallexample @noindent -then objects of this type will always be 32 bits long. In the case of +then objects 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 -zero-extended as appropriate. If more than 64 bits is specified, then +zero-extended as appropriate. If more than 64 bits is specified, then padding space is allocated after the value, and a warning is issued that there are unused bits. 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 +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**32-1. Since this is a +The largest Size value permitted in GNAT is 2**32@minus{}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 +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. @@ -7317,12 +7436,12 @@ type Integer. @noindent For tasks, the @code{Storage_Size} clause specifies the amount of space -to be allocated for the task stack. This cannot be extended, and if the +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. If the default size of 20K bytes is insufficient, +checking is enabled. If the default size of 20K bytes is insufficient, then you need to use a @code{Storage_Size} attribute definition clause, or a @code{Storage_Size} pragma in the task definition to set the -appropriate required size. A useful technique is to include in every +appropriate required size. A useful technique is to include in every task definition a pragma of the form: @smallexample @@ -7331,11 +7450,11 @@ task definition a pragma of the form: @noindent Then Default_Stack_Size can be defined in a global package, and modified -as required. Any tasks requiring different task stack sizes from the +as required. Any tasks requiring different task stack sizes from the default can have an appropriate alternative reference in the pragma. For access types, the @code{Storage_Size} clause specifies the maximum -space available for allocation of objects of the type. If this space is +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. 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 @@ -7344,10 +7463,10 @@ 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 +@code{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: +size storage pool is eliminated. Consider the following example: @smallexample procedure p is @@ -7361,17 +7480,17 @@ size storage pool is eliminated. Consider the following example: procedure g (m : P); pragma Import (C, g); - -- ... + -- @dots{} begin - -- ... + -- @dots{} y := new R; end; @end smallexample @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 +connection with interfacing where no object will ever be allocated. If you compile the above example, you get the warning: @smallexample @@ -7391,7 +7510,7 @@ case of such an access declaration. @noindent An issue arises in the case of variant record objects of whether Size gives information about a particular variant, or the maximum size required -for any variant. Consider the following program +for any variant. Consider the following program @smallexample with Text_IO; use Text_IO; @@ -7416,7 +7535,7 @@ end q; 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 +which is only 8 bits long. However, the result of running the program is: @smallexample @@ -7426,8 +7545,8 @@ program is: @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 +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 other hand, in the case of V2, the initial discriminant value is False (from the default), but it is possible to assign a True variant value to V2, therefore 16 bits must be allocated for V2 @@ -7442,7 +7561,7 @@ be made here, but the GNAT behavior seems most consistent with the 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 +variant, rather than the size of the largest variant. This can be achieved in GNAT by making use of the fact that in the case of a subprogram parameter, GNAT does indeed return the size of the current variant (because a subprogram has no way of knowing how much space @@ -7500,7 +7619,7 @@ variant value. @noindent 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, @code{GNAT} uses an unsigned biased representation, +value, and in such cases, GNAT uses an unsigned biased representation, in which zero is used to represent the lower bound, and successive values represent successive values of the type. @@ -7525,7 +7644,7 @@ scheme: @noindent Biased representation is only used if the specified @code{Size} clause -cannot be accepted in any other manner. These reduced sizes that force +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. @@ -7537,13 +7656,13 @@ enumeration types for which a representation clause is given. @noindent In Ada 95, the @code{Size} of a discrete type is the minimum number of bits -required to hold values of the type. Although this interpretation was +required to hold values of the type. 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. However, in Ada-95, +can cause some significant difficulties. For example, in most Ada 83 +compilers, @code{Natural'Size} was 32. However, in Ada-95, @code{Natural'Size} is -typically 31. This means that code may change in behavior when moving -from Ada 83 to Ada 95. For example, consider: +typically 31. This means that code may change in behavior when moving +from Ada 83 to Ada 95. For example, consider: @smallexample type Rec is record; @@ -7565,15 +7684,15 @@ surprising 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 -dependent attributes @code{Value_Size} and @code{Object_Size}. When +dependent attributes @code{Value_Size} and @code{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 -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 -the basis of the determination of the size. The backend is free to +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 +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 character might be stored in 32 bits on a machine with no efficient byte access instructions such as the Alpha. @@ -7584,8 +7703,8 @@ discrete types are as follows: @itemize @bullet @item The @code{Object_Size} for base subtypes reflect the natural hardware -size in bits (run the utility gnatpsta to find those values for numeric types). -Enumeration types and fixed-point base subtypes have 8. 16. 32 or 64 +size in bits (run the utility @code{gnatpsta} 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 @@ -7602,8 +7721,8 @@ from the parent first subtype. @noindent The @code{Value_Size} attribute is the number of bits required to store a value -of the type. This size can be referred to using the @code{Value_Size} -attribute. This value is used to determine how tightly to pack +of the type. This size can be referred to using the @code{Value_Size} +attribute. 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 @@ -7619,13 +7738,13 @@ only if negative values are possible). @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 @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''.) @item All other subtypes have a @code{Value_Size} corresponding to the minimum -number of bits required to store all values of the subtype. For +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 @@ -7634,20 +7753,20 @@ to the corresponding bound of the ancestor The RM defined attribute @code{Size} corresponds to the @code{Value_Size} attribute. -The @code{Size} attribute may be defined for a first-named subtype. This sets +The @code{Size} attribute may be defined for a first-named subtype. This sets the @code{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 -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 +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 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 @code{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 -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 +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} values as a result of explicit attribute definition clauses, then it is erroneous to convert from one access subtype to the other. @@ -7663,9 +7782,9 @@ that in each case the base is short_short_integer with a size of 8): @smallexample Object_Size Value_Size -type x1 is range 0..5; 8 3 +type x1 is range 0 .. 5; 8 3 -type x2 is range 0..5; +type x2 is range 0 .. 5; for x2'size use 12; 12 12 subtype x3 is x2 range 0 .. 3; 12 2 @@ -7715,10 +7834,10 @@ In other words, the value specified must be at least equal to the size of this subtype, and must be a multiple of the alignment value. In addition, component size clauses are allowed which cause the array -to be packed, by specifying a smaller value. The cases in which this -is allowed are for component size values in the range 1-63. 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 +to be packed, by specifying a smaller value. The cases in which this +is allowed are for 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 @@ -7739,21 +7858,21 @@ less efficient than if the natural component size of 32 is used. @noindent For record subtypes, GNAT permits the specification of the @code{Bit_Order} -attribute. The specification may either correspond to the default bit +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 setting (that is the opposite of the default). In the case where the non-standard value is specified, the effect is to renumber bits within each byte, but the ordering of bytes is not -affected. There are certain +affected. There are certain restrictions placed on component clauses as follows: @itemize @bullet @item Components fitting within a single storage unit. @noindent -These are unrestricted, and the effect is merely to renumber bits. For +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} being the default, then the following two declarations have exactly the same effect: @@ -7789,7 +7908,7 @@ the same, regardless of whether the target is little-endian or big-endian. @item Components occupying an integral number of bytes. @noindent -These are components that exactly fit in two or more bytes. Such component +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. In particular, the following attempt at getting an endian-independent integer @@ -7811,14 +7930,14 @@ does not work: 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 +little-endian machines, this must be explicitly programmed. This capability is not provided by @code{Bit_Order}. @item Components that are positioned across byte boundaries @noindent -but do not occupy an integral number of bytes. Given that bytes are not +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 +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@. @@ -7828,8 +7947,8 @@ will be flagged as illegal by GNAT@. 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 Suppress} if desired. The following section contains additional +generate a warning. This warning may be suppressed using +@code{pragma Suppress} if desired. The following section contains additional details regarding the issue of byte ordering. @node Effect of Bit_Order on Byte Ordering @@ -7839,10 +7958,10 @@ details regarding the issue of byte ordering. @noindent In this section we will review the effect of the @code{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 +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 @code{Bit_Order}. The effect of a non-standard bit order is described in section 15.5.3 of the Ada Reference Manual: @@ -7857,7 +7976,7 @@ this context, we visit section 13.5.1 of the manual: @smallexample 13 A record_representation_clause (without the mod_clause) -specifies the layout. The storage place attributes (see 13.5.2) +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. @@ -7865,24 +7984,24 @@ less than Storage_Unit. @noindent The critical point here is that storage places are taken from -the values after normalization, not before. So the @code{Bit_Order} -interpretation applies to normalized values. The interpretation +the values after normalization, not before. So the @code{Bit_Order} +interpretation applies to normalized values. The interpretation is described in the later part of the 15.5.3 paragraph: @smallexample 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 +integer value). Low_Order_First (known in the vernacular as +``little endian'') means the opposite: the first bit is the least significant. @end smallexample @noindent Note that the numbering is with respect to the bits of a storage -unit. In other words, the specification affects only the numbering +unit. In other words, the specification affects only the numbering of bits within a single storage unit. We can make the effect clearer by giving an example. @@ -7892,8 +8011,8 @@ 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 remaing 7 bits are called V1, V2 .. V7, where V7 is the right most -(least significant bit). +the remaining 7 bits are called V1, V2, @dots{} V7, where V7 is the rightmost +(least significant) bit. On a big-endian machine, we can write the following representation clause @@ -7963,11 +8082,11 @@ the byte is backwards, so we have to rewrite the record rep clause as: @end smallexample It is a nuisance to have to rewrite the clause, especially if -the code has to be maintained on both machines. However, +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. Note that the implementation is not required on byte addressed -machines, but it is indeed implemented in @code{GNAT}. +machines, but it is indeed implemented in GNAT. This means that we can simply use the first record clause, together with the declaration @@ -7977,7 +8096,7 @@ first record clause, together with the declaration @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-endial or little-endian +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. @@ -7989,16 +8108,16 @@ example as: @smallexample 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; + 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; @@ -8035,8 +8154,8 @@ This is exactly equivalent to saying (a repeat of the first example): @noindent Why are they equivalent? Well take a specific field, the @code{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 +field. The storage place attributes are obtained by normalizing the +values given so that the @code{First_Bit} value is less than 8. After nromalizing the values (0,10,10) we get (1,2,2) which is exactly what we specified in the other case. @@ -8053,11 +8172,11 @@ may be actively confusing to specify such a value, so the compiler generates a warning for such usage. 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 +values must be used. If in our example, the slave byte came first on some machines we might write: @smallexample - Master_Byte_First constant Boolean := ...; + Master_Byte_First constant Boolean := @dots{}; Master_Byte : constant Natural := 1 - Boolean'Pos (Master_Byte_First); @@ -8095,8 +8214,8 @@ an appropriate manner. @cindex Pragma Pack (for arrays) @noindent -Pragma 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 +Pragma @code{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 @@ -8112,7 +8231,7 @@ Any packed array type with a static size @noindent For all these cases, if the component subtype size is in the range -1- 63, then the effect of the pragma Pack is exactly as though a +1 through 63, then the effect of the pragma @code{Pack} is exactly as though a component size were specified giving the component subtype size. For example if we have: @@ -8128,19 +8247,19 @@ 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. Note that in some cases this rather fierce approach to packing can produce -unexpected effects. For example, in Ada 95, type Natural typically has a +unexpected effects. For example, in Ada 95, type Natural typically has a size of 31, meaning that if you pack an array of 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 Pack that it guesses -might not be what is intended. You can easily remove this warning by -using an explicit Component_Size setting instead, which never generates +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 +might not be what is intended. You can easily remove this warning by +using an explicit @code{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 +GNAT treats packed arrays in one of two ways. If the size of the array is known at compile time and is less than 64 bits, then internally the array is represented as a single modular type, of exactly the appropriate number -of bits. If the length is greater than 63 bits, or is not known at compile +of bits. If the length is greater than 63 bits, or is not known at compile time, then the packed array is represented as an array of bytes, and the length is always a multiple of 8 bits. @@ -8149,10 +8268,10 @@ length is always a multiple of 8 bits. @cindex Pragma Pack (for records) @noindent -Pragma Pack applied to a record will pack the components to reduce wasted +Pragma @code{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 package components and non-packable -components. Components of the following types are considered packable: +components. We distinguish between package components and non-packable +components. Components of the following types are considered packable: @itemize @bullet @item @@ -8204,10 +8323,10 @@ The representation for the record x2 is as follows: @smallexample for x2'Size use 224; for x2 use record - l1 at 0 range 0 .. 0; + l1 at 0 range 0 .. 0; l2 at 0 range 1 .. 64; l3 at 12 range 0 .. 31; - l4 at 16 range 0 .. 0; + l4 at 16 range 0 .. 0; l5 at 16 range 1 .. 13; l6 at 18 range 0 .. 71; end record; @@ -8218,12 +8337,12 @@ Studying this example, we see that the packable fields @code{l1} and @code{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, so +eliminate padding. But @code{l3} is of a non-packable float type, 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 -array that is longer than 64 bits, so it is itself non-packable. Thus +minimally packed with no gaps. However, type @code{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. @@ -8233,19 +8352,19 @@ integral number of bytes, i.e.@: 72 bits. @noindent 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 +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 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, +(actually the Value_Size). There are no restrictions due to alignment, and such components may freely cross storage boundaries. -Packed arrays with a size up to and including 64-bits are represented +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: +thus the same lack of restriction applies. For example, if you declare: @smallexample type R is array (1 .. 49) of Boolean; @@ -8258,12 +8377,12 @@ 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. For non-primitive types, including packed arrays with a size greater than -64-bits, component clauses must respect the alignment requirement of the +64 bits, component clauses must respect the alignment requirement of the type, in particular, always starting on a byte boundary, and the length must be a multiple of the storage unit. The tag field of a tagged type always occupies an address sized field at -the start of the record. No component clause may attempt to overlay this +the start of the record. No component clause may attempt to overlay this tag. In the case of a record extension T1, of a type T, no component clause applied @@ -8274,7 +8393,7 @@ T'Size bytes of the record. @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 +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 @@ -8290,7 +8409,7 @@ be in the range: @end smallexample @noindent -A "confirming" representation clause is one in which the values range +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 for an enumeration type. Such a confirming representation @@ -8299,7 +8418,7 @@ that no extra overhead results from the use of such a clause. 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: +manner. Consider the declarations: @smallexample type r is (A, B, C); @@ -8309,10 +8428,10 @@ manner. Consider the declarations: @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 @code{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 @code{Pos} attribute). @node Address Clauses @section Address Clauses @@ -8332,27 +8451,27 @@ as found in RM 13.1(22): @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 +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): @smallexample 22.a Reason: This is to avoid the following sort of thing: - 22.b X : Integer := F(...); - Y : Address := G(...); + 22.b X : Integer := F(@dots{}); + Y : Address := G(@dots{}); for X'Address use Y; 22.c In the above, we have to evaluate the initialization expression for X before we - know where to put the result. This seems + know where to put the result. This seems like an unreasonable implementation burden. 22.d The above code should instead be written like this: - 22.e Y : constant Address := G(...); - X : Integer := F(...); + 22.e Y : constant Address := G(@dots{}); + X : Integer := F(@dots{}); for X'Address use Y; 22.f This allows the expression ``Y'' to be safely @@ -8361,18 +8480,18 @@ the AARM notes in sections 13.1 (22.a-22.h): 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 + 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 smallexample @noindent -GNAT does indeed permit many additional cases of non-static expressions. In +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, -if one is present, is inexpensive). In addition, if there is no implicit or -explicit initialization, then there are no restrictions. GNAT will reject +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 @@ -8384,7 +8503,7 @@ The type of the item is non-elementary (e.g.@: a record or array). There is explicit or implicit initialization required for the object. @item -The address value is non-static. Here GNAT is more permissive than the +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. @@ -8400,12 +8519,26 @@ a component of a discriminated record. @end itemize @noindent -As noted above in section 22.h, address values are typically non-static. In +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 +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: +Another issue with address clauses is the interaction with alignment +requirements. When an address clause is given for an object, the address +value must be consistent with the alignment of the object (which is usually +the same as the alignment of the type of the object). If an address clause +is given that specifies an inappropriately aligned address value, then the +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 +check is suppressed if range checks are suppressed, or if +@code{pragma Restrictions (No_Elaboration_Code)} is in effect. + @findex Attribute @findex To_Address @smallexample @@ -8419,28 +8552,28 @@ 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 +unchecked_conversion of a static integer value. This simplifies the porting of legacy code, and provides a portable equivalent to the GNAT attribute To_Address. @findex Export -An address clause cannot be given for an exported object. More +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 +clause cannot be exported. This is because such variables are not defined by the Ada program, so there is no external object so export. @findex 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 -and the external name are ignored in this case. The reason that we allow this +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 +and the external name are ignored in this case. The reason that we allow this combination is that it provides a useful idiom to avoid unwanted initializations on objects with address clauses. When an address clause is given for an object that has implicit or -explicit initialization, then by default initialization takes place. This +explicit initialization, then by default initialization takes place. This means that the effect of the object declaration is to overwrite the -memory at the specified address. This is almost always not what the +memory at the specified address. This is almost always not what the programmer wants, so GNAT will output a warning: @smallexample @@ -8463,8 +8596,8 @@ programmer wants, so GNAT will output a warning: @noindent 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 +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 @@ -8486,10 +8619,10 @@ without warnings (and the initialization is suppressed): @noindent Normally the specification of a foreign language convention for a type or -an object has no effect on the chosen representation. In particular, the +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 three exceptions to this general rule: @@ -8504,7 +8637,7 @@ column-major manner, instead of the normal default row-major order. @item 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 +to accommodate all values of the type. For example, for the enumeration type declared by: @smallexample @@ -8513,16 +8646,16 @@ type declared by: @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 -convention is to use 32-bits for all enum values in C, since enum values -are essentially of type int. If pragma Convention C is specified for an +of type @code{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 Ada enumeration type, then the size is modified as necessary (usually to 32 bits) to be consistent with the C convention for enum values. @item 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 +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 @@ -8537,7 +8670,7 @@ C or Fortran convention for a derived Boolean, as in the following example: @end smallexample @noindent -then the GNAT generated code will treat any nonzero value as true. For truth +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. @@ -8546,7 +8679,7 @@ when one of these values is read, any nonzero value is treated as True. @node Determining the Representations chosen by GNAT @section Determining the Representations chosen by GNAT @cindex Representation, determination of -@cindex -gnatR switch +@cindex @code{-gnatR} switch @noindent Although the descriptions in this section are intended to be complete, it is @@ -8554,19 +8687,19 @@ often easier to simply experiment to see what GNAT accepts and what the effect is on the layout of types and objects. As required by the Ada RM, if a representation clause is not accepted, then -it must be rejected as illegal by the compiler. However, when a representation +it must be rejected as illegal by the compiler. However, when a representation clause or pragma is accepted, there can still be questions of what the -compiler actually does. For example, if a partial record representation +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 pack is used on a +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 Pack in this chapter can be used to answer the second question, +on pragma @code{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 @code{-gnatR}. If you compile +For this purpose, GNAT provides the option @code{-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: +clauses. For example, if we compile the package: @smallexample package q is @@ -8622,7 +8755,7 @@ Representation information for unit q for r'Size use ??; for r'Alignment use 4; for r use record - x at 4 range 0 .. 7; + x at 4 range 0 .. 7; _tag at 0 range 0 .. 31; s at 5 range 0 .. 799; end record; @@ -8630,7 +8763,7 @@ end record; for r2'Size use 160; for r2'Alignment use 4; for r2 use record - x at 4 range 0 .. 7; + x at 4 range 0 .. 7; _tag at 0 range 0 .. 31; _parent at 0 range 0 .. 63; y2 at 16 range 0 .. 31; @@ -8639,7 +8772,7 @@ end record; for x'Size use 8; for x'Alignment use 1; for x use record - y at 0 range 0 .. 7; + y at 0 range 0 .. 7; end record; for x1'Size use 112; @@ -8657,10 +8790,10 @@ for rb2'Component_Size use 1; for x2'Size use 224; for x2'Alignment use 4; for x2 use record - l1 at 0 range 0 .. 0; + l1 at 0 range 0 .. 0; l2 at 0 range 1 .. 64; l3 at 12 range 0 .. 31; - l4 at 16 range 0 .. 0; + l4 at 16 range 0 .. 0; l5 at 16 range 1 .. 13; l6 at 18 range 0 .. 71; end record; @@ -8684,8 +8817,8 @@ fields present, including the parent field, which is a copy of the fields 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 Pack on these arrays, and the record -representation clause for type x2 shows how pragma Pack affects +the exact effect of pragma @code{Pack} on these arrays, and the record +representation clause for type x2 shows how pragma @code{Pack} affects this record type. In some cases, it may be useful to cut and paste the representation clauses @@ -8698,7 +8831,7 @@ the actual representation to be used. @noindent The Ada 95 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 +program, and which must be provided by all Ada compilers. They are analogous to the standard C library used by C programs. GNAT implements all of the facilities described in annex A, and for most @@ -8708,8 +8841,8 @@ 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}, gives details on exactly how GNAT interfaces to the -file system. For the remaining packages, the Ada 95 reference manual -should be sufficient. The following is a list of the packages included, +file system. For the remaining packages, the Ada 95 reference manual +should be sufficient. The following is a list of the packages included, together with a brief description of the functionality that is provided. For completeness, references are included to other predefined library @@ -8718,7 +8851,7 @@ cross-indexed from annex A). @table @code @item Ada (A.2) -This is a parent package for all the standard library packages. It is +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. @@ -8736,16 +8869,16 @@ for letters, or digits). @item Ada.Characters.Latin_1 (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 -will run in international environments. For example, if you want an +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 @code{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) This package provides access to the command line parameters and the name -of the current program (analogous to the use of argc and argv in C), and +of the current program (analogous to the use of @code{argc} and @code{argv} in C), and also allows the exit status for the program to be set in a system-independent manner. @@ -8788,7 +8921,7 @@ the standard IO packages. @item Ada.Numerics This package contains some standard constants and exceptions used -throughout the numerics packages. Note that the constants pi and e are +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. @@ -8813,10 +8946,10 @@ uniformly distributed floating point values. @item 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 an +implementation of standard elementary functions (such as log and trigonometric functions) for an arbitrary complex type. -The following predefined instantiations of this package exist +The following predefined instantiations of this package are provided: @table @code @item Short_Float @@ -8860,7 +8993,11 @@ The following predefined instantiations of this package exist @item Ada.Real_Time (D.8) This package provides facilities similar to those of @code{Calendar}, but -operating with a finer clock suitable for real time control. +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.Sequential_IO (A.8.1) This package provides input-output facilities for sequential files, @@ -8869,7 +9006,7 @@ any Ada type, including indefinite (unconstrained) types. @item Ada.Storage_IO (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 +from a storage buffer. It is primarily intended for the creation of new IO packages. @item Ada.Streams (13.13.1) @@ -8880,7 +9017,7 @@ concept of streams as used by the stream attributes (@code{Input}, @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 -Stream_IO capability. The Stream_IO model permits both random and +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. @@ -8890,7 +9027,7 @@ packages. @item Ada.Strings.Bounded (A.4.4) This package provides facilities for handling variable length -strings. The bounded model requires a maximum length. It is thus +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. @@ -8899,21 +9036,21 @@ This package provides facilities for handling fixed length strings. @item Ada.Strings.Maps (A.4.2) This package provides facilities for handling character mappings and -arbitrarily defined subsets of characters. For instance it is useful in +arbitrarily defined subsets of characters. For instance it is useful in defining specialized translation tables. @item Ada.Strings.Maps.Constants (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 +predefined character sets. For example, the standard upper to lower case +conversion table is found in this package. Note that upper to lower case conversion is non-trivial if you want to take the entire set of characters, including extended characters like E with an acute accent, -into account. You should use the mappings in this package (rather than +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) This package provides facilities for handling variable length -strings. The unbounded model allows arbitrary length strings, but +strings. The unbounded model allows arbitrary length strings, but requires the use of dynamic allocation and finalization. @item Ada.Strings.Wide_Bounded (A.4.7) @@ -8940,7 +9077,7 @@ task-specific data with separate tasks. @item Ada.Text_IO This package provides basic text input-output capabilities for -character, string and numeric data. The subpackages of this +character, string and numeric data. The subpackages of this package are listed next. @item Ada.Text_IO.Decimal_IO @@ -8953,7 +9090,7 @@ Provides input-output facilities for enumeration types. Provides input-output facilities for ordinary fixed-point types. @item Ada.Text_IO.Float_IO -Provides input-output facilities for float types. The following +Provides input-output facilities for float types. The following predefined instantiations of this generic package are available: @table @code @@ -8966,7 +9103,7 @@ predefined instantiations of this generic package are available: @end table @item Ada.Text_IO.Integer_IO -Provides input-output facilities for integer types. The following +Provides input-output facilities for integer types. The following predefined instantiations of this generic package are available: @table @code @@ -8991,7 +9128,7 @@ data. @item 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 +of pictures in COBOL@. The picture formats used by this package are a close copy of the facility in COBOL@. @item Ada.Text_IO.Text_Streams (A.12.2) @@ -9006,24 +9143,24 @@ special circumstances. If the types have the same Size (more accurately the same Value_Size), then the effect is simply to transfer the bits from the source to the -target type without any modification. This usage is well defined, and +target type without any modification. This usage is well defined, and for simple types whose representation is typically the same across all implementations, gives a portable method of performing such conversions. If the types do not have the same size, then the result is implementation -defined, and thus may be non-portable. The following describes how GNAT +defined, and thus may be non-portable. The following describes how GNAT handles such unchecked conversion cases. If the types are of different sizes, and are both discrete types, then the effect is of a normal type conversion without any constraint checking. In particular if the result type has a larger size, the result will be -zero or sign extended. If the result type has a smaller size, the result +zero or sign extended. If the result type has a smaller size, the result will be truncated by ignoring high order bits. If the types are of different sizes, and are not both discrete types, then the conversion works as though pointers were created to the source -and target, and the pointer value is converted. The effect is that bits +and target, and the pointer value is converted. The effect is that bits are copied from successive low order storage units and bits of the source up to the length of the target type. @@ -9032,19 +9169,19 @@ case is implementation dependent, and the above behavior may not match that of some other compiler. A pointer to one type may be converted to a pointer to another type using -unchecked conversion. The only case in which the effect is undefined is -when one or both pointers are pointers to unconstrained array types. In +unchecked conversion. The only case in which the effect is undefined is +when one or both pointers are pointers to unconstrained array types. In this case, the bounds information may get incorrectly transferred, and in particular, GNAT uses double size pointers for such types, and it is -meaningless to convert between such pointer types. GNAT will issue a +meaningless to convert between such pointer types. GNAT will issue a warning if the alignment of the target designated type is more strict than the alignment of the source designated type (since the result may be unaligned in this case). A pointer other than a pointer to an unconstrained array type may be -converted to and from System.Address. Such usage is common in Ada 83 +converted to and from System.Address. Such usage is common in Ada 83 programs, but note that Ada.Address_To_Access_Conversions is the -preferred method of performing such conversions in Ada 95. Neither +preferred method of performing such conversions in Ada 95. Neither 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. @@ -9057,7 +9194,7 @@ allocated by use of an allocator. This package is similar to @code{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}. It contains generic subpackages listed next. +and @code{String}. It contains generic subpackages listed next. @item Ada.Wide_Text_IO.Decimal_IO Provides input-output facilities for decimal fixed-point types @@ -9069,7 +9206,7 @@ Provides input-output facilities for enumeration types. Provides input-output facilities for ordinary fixed-point types. @item Ada.Wide_Text_IO.Float_IO -Provides input-output facilities for float types. The following +Provides input-output facilities for float types. The following predefined instantiations of this generic package are available: @table @code @@ -9082,7 +9219,7 @@ predefined instantiations of this generic package are available: @end table @item Ada.Wide_Text_IO.Integer_IO -Provides input-output facilities for integer types. The following +Provides input-output facilities for integer types. The following predefined instantiations of this generic package are available: @table @code @@ -9120,12 +9257,12 @@ types are @code{Wide_Character} and @code{Wide_String} instead of @noindent GNAT implements all the required input-output facilities described in -A.6 through A.14. These sections of the Ada 95 reference manual describe the +A.6 through A.14. These sections of the Ada 95 reference manual describe the required behavior of these packages from the Ada point of view, and if you are writing a portable Ada program that does not need to know the exact manner in which Ada maps to the outside world when it comes to reading or writing external files, then you do not need to read this -chapter. As long as your files are all regular files (not pipes or +chapter. As long as your files are all regular files (not pipes or devices), and as long as you write and read the files only from Ada, the description in the Ada 95 reference manual is sufficient. @@ -9136,14 +9273,14 @@ language, then you need to know more about the details of how the GNAT implementation of these input-output facilities behaves. In this chapter we give a detailed description of exactly how GNAT -interfaces to the file system. As always, the sources of the system are +interfaces to the file system. As always, the sources of the system are available to you for answering questions at an even more detailed level, but for most purposes the information in this chapter will suffice. Another reason that you may need to know more about how input-output is implemented arises when you have a program written in mixed languages where, for example, files are shared between the C and Ada sections of -the same program. GNAT provides some additional facilities, in the form +the same program. GNAT provides some additional facilities, in the form of additional child library packages, that facilitate this sharing, and these additional facilities are also described in this chapter. @@ -9199,9 +9336,9 @@ All files are opened using @code{fopen}. All input/output operations use @code{fread}/@code{fwrite}. @end itemize -There is no internal buffering of any kind at the Ada library level. The +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 C library routines that support streams. This +implementation of the C library routines that support streams. This facilitates shared use of these streams by mixed language programs. @node FORM Strings @@ -9211,12 +9348,12 @@ facilitates shared use of these streams by mixed language programs. The format of a FORM string in GNAT is: @smallexample -"keyword=value,keyword=value,...,keyword=value" +"keyword=value,keyword=value,@dots{},keyword=value" @end smallexample @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 +between values. The order of the entries is not important. Currently there are two keywords defined. @smallexample @@ -9230,17 +9367,17 @@ The use of these parameters is described later in this section. @section Direct_IO @noindent -Direct_IO can only be instantiated for definite types. This is a +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 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 +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} - -1)*4. +4-bytes, so the record at index @var{K} starts at offset +(@var{K}@minus{}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. @@ -9254,28 +9391,28 @@ or indefinite (unconstrained) type. For the definite type case, the elements written to the file are simply the memory images of the data values with no control information of any -kind. The resulting file should be read using the same type, no validity +kind. The resulting file should be read using the same type, no validity 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 +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 -the data value. The resulting file can only be read using the same -(unconstrained) type. Normal assignment checks are performed on these +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 -raised. In particular, in the array case, the lengths must match, and in +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}: +arrays. For example, the following will raise @code{Data_Error}: @smallexample 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); @@ -9289,7 +9426,7 @@ clearly incorrect, since there is only one element in the file, and that element is the string @samp{hello!}. In Ada 95, this kind of behavior can be legitimately achieved using -Stream_IO, and this is the preferred mechanism. In particular, the above +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 @@ -9319,18 +9456,18 @@ end of a page and consequently can appear only immediately following a @item The file ends with either @code{LF} (line mark) or @code{LF}-@code{FF} -(line mark, page mark). In the former case, the page mark is implicitly +(line mark, page mark). In the former case, the page mark is implicitly assumed to be present. @end itemize 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 +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 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 95 reference manual and all the routines in Text_IO are fully implemented. @@ -9353,10 +9490,10 @@ i.e.@: there is no explicit line mark or page mark at the end of the file. @end itemize 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 +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} 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 +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 the file. @@ -9374,15 +9511,15 @@ the file. @noindent @code{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 +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 -mark. Text_IO maintains an internal flag so that subsequent read +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. @@ -9391,7 +9528,7 @@ After a call to @code{End_Of_File} that returns @code{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, -and past a possible page mark following the line mark. Again Text_IO +and past a possible page mark following the line mark. Again Text_IO maintains internal flags so that subsequent read operations properly handle the logical position. @end itemize @@ -9406,21 +9543,21 @@ situations. @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 +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 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 @code{Ascii.FF} characters (the character normally used for a page mark) appearing in the file are considered to be data -characters. In particular: +characters. In particular: @itemize @bullet @item @code{Get_Line} and @code{Skip_Line} do not test for a page mark -following a line mark. If a page mark appears, it will be treated as a +following a line mark. If a page mark appears, it will be treated as a data character. @item @@ -9435,14 +9572,14 @@ entered from the pipe to complete one of these operations. the end of the file. @end itemize -Output to non-regular files is the same as for regular files. Page marks +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 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 @code{EOT} key, +of file indication is not ``sticky''. If an end of file is entered, e.g.@: by +pressing the @key{EOT} key, then end of file is signalled once (i.e.@: the test @code{End_Of_File} will yield @code{True}, or a read will @@ -9456,12 +9593,12 @@ file indication, until another end of file indication is entered. @noindent 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 +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 file positioned past the control character, and it is thus not treated -as having its normal function. This means that page, line and column +as having its normal function. This means that page, line and column counts after this kind of Get_Immediate call are set as though the mark -did not occur. In the case where a Get_Immediate leaves the file +did not occur. In the case where a Get_Immediate leaves the file 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. @@ -9472,10 +9609,10 @@ page mark. @noindent The package @code{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 +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 -format. Similarly if read operations are used to read from a Text_IO +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 skipped and the effect is similar to that described above for @code{Get_Immediate}. @@ -9494,7 +9631,7 @@ Determines if a file of the given name exists and can be successfully opened (without actually performing the open operation). @item function Get_Line return String; -Reads a string from the standard input file. The value returned is exactly +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; @@ -9533,11 +9670,11 @@ that an extra copy is avoided. @noindent In the above procedures, @code{File} is of type @code{Ada.Text_IO.File_Type} -and is optional. If the parameter is omitted, then the standard input or +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 @code{a-swuwti.ads/adb} provides similar extended @code{Wide_Text_IO} +files @file{a-swuwti.ads} and @file{a-swuwti.adb} provides similar extended @code{Wide_Text_IO} functionality for unbounded wide strings. @node Wide_Text_IO @@ -9546,7 +9683,7 @@ functionality for unbounded wide strings. @noindent @code{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 +wide character values. The encoding scheme for a given file may be specified using a FORM parameter: @smallexample @@ -9593,31 +9730,31 @@ ESC a b c d @end smallexample where @var{a}, @var{b}, @var{c}, @var{d} are the four hexadecimal -characters (using upper case letters) of the wide character code. For +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 +16#A345#. This scheme is compatible with use of the full @code{Wide_Character} set. @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 -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 +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 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 +described above. The internal character code is the corresponding JIS character according to the standard algorithm for Shift-JIS -conversion. Only characters defined in the JIS code set table can be +conversion. Only characters defined in the JIS code set table can be used with this encoding method. @item 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 +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 +encoding algorithm. Only characters defined in the JIS code set table can be used with this encoding method. @item UTF-8 Coding @@ -9633,13 +9770,13 @@ is a one, two, or three byte sequence: @end smallexample where the xxx bits correspond to the left-padded bits of the -16-bit character value. Note that all lower half ASCII characters +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 (The full UTF-8 scheme allows for encoding 31-bit characters as 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 illegal UTF-8 sequences.) +will all invalid UTF-8 sequences.) @item Brackets Coding In this encoding, a wide character is represented by the following eight @@ -9650,21 +9787,21 @@ character sequence: @end smallexample Where @code{a}, @code{b}, @code{c}, @code{d} are the four hexadecimal -characters (using uppercase letters) of the wide character code. For +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#}. 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 +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 For the coding schemes other than Hex and Brackets encoding, not all wide character -values can be represented. An attempt to output a character that cannot +values can be represented. An attempt to output a character that cannot be represented using the encoding scheme for the file causes -Constraint_Error to be raised. An invalid wide character sequence on +Constraint_Error to be raised. An invalid wide character sequence on input also causes Constraint_Error to be raised. @menu @@ -9677,7 +9814,7 @@ input also causes Constraint_Error to be raised. @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 +of stream pointer positioning (@pxref{Text_IO}). There is one additional case: If @code{Ada.Wide_Text_IO.Look_Ahead} reads a character outside the @@ -9690,10 +9827,10 @@ Wide_Character'Val (16#0080#) .. Wide_Character'Val (16#FFFF#) @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 -wide character sequence. Again this is to avoid the need for buffering +wide character sequence. Again this is to avoid the need for buffering or backup, and all @code{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 @code{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 @@ -9703,7 +9840,7 @@ can be observed if the wide text file shares a stream with another file. 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 +@code{False}. Similarly, the end of file indication is not sticky, so it is possible to read beyond an end of file. @node Stream_IO @@ -9711,8 +9848,8 @@ it is possible to read beyond an end of file. @noindent A stream file is a sequence of bytes, where individual elements are -written to the file as described in the Ada 95 reference manual. The type -@code{Stream_Element} is simply a byte. There are two ways to read or +written to the file as described in the Ada 95 reference manual. The type +@code{Stream_Element} is simply a byte. There are two ways to read or write a stream file. @itemize @bullet @@ -9741,15 +9878,15 @@ dependence, GNAT handles file sharing as follows: @item In the absence of a @samp{shared=@var{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 -raised. Note that a file that is not explicitly closed by the program +and is not supported. The exception @code{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 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 +opened. The exact effect depends on how the C stream routines handle multiple accesses to the same external files using separate streams. @item @@ -9770,18 +9907,18 @@ and @code{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 -parameter is used in the program. In this case, you must examine the +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 +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 +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) 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 +heterogeneous input-output. Although this approach will work in GNAT if @samp{shared=yes} is specified, it is preferable in Ada 95 to use Stream_IO for this purpose (using the stream attributes) @@ -9804,14 +9941,14 @@ Inout_File "r+" "w+" @end smallexample If text file translation is required, then either @samp{b} or @samp{t} -is added to the mode, depending on the setting of Text. Text file +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 +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 +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 +@code{In_File} and @code{Out_File} cases. If a @code{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. @@ -9835,8 +9972,8 @@ package Interfaces.C_Streams is subtype long is Long_Integer; -- Note: the above types are subtypes deliberately, and it -- is part of this spec that the above correspondences are - -- guaranteed. This means that it is legitimate to, for - -- example, use Integer instead of int. We provide these + -- guaranteed. This means that it is legitimate to, for + -- example, use Integer instead of int. We provide these -- synonyms for clarity, but in some cases it may be -- convenient to use the underlying types (for example to -- avoid an unnecessary dependency of a spec on the spec @@ -9868,8 +10005,8 @@ package Interfaces.C_Streams is -------------------------- -- The functions selected below are ones that are -- available in DOS, OS/2, UNIX and Xenix (but not - -- necessarily in ANSI C). These are very thin interfaces - -- which copy exactly the C headers. For more + -- necessarily in ANSI C). These are very thin interfaces + -- which copy exactly the C headers. For more -- documentation on these functions, see the Microsoft C -- "Run-Time Library Reference" (Microsoft Press, 1990, -- ISBN 1-55615-225-6), which includes useful information @@ -9889,7 +10026,7 @@ package Interfaces.C_Streams is -- Note: to maintain target independence, use -- text_translation_required, a boolean variable defined in -- a-sysdep.c to deal with the target dependent text - -- translation requirement. If this variable is set, + -- translation requirement. If this variable is set, -- then b/t should be appended to the standard mode -- argument to set the text translation mode off or on -- as required. @@ -9938,7 +10075,7 @@ package Interfaces.C_Streams is -- Extra functions -- --------------------- -- These functions supply slightly thicker bindings than - -- those above. They are derived from functions in the + -- those above. They are derived from functions in the -- C Run-Time Library, but may do a bit more work than -- just directly calling one of the Library functions. function is_regular_file (handle : int) return int; @@ -9949,9 +10086,9 @@ 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 - -- normal UNIX mode). Use fileno to get a stream handle. + -- binary to text mode or vice versa. These functions have + -- 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); ---------------------------- @@ -9962,9 +10099,9 @@ package Interfaces.C_Streams is -- name, returns in buffer a NUL terminated string -- representing the full path name for the file name. -- On systems where it is relevant the drive is also - -- part of the full path name. It is the responsibility + -- part of the full path name. It is the responsibility -- of the caller to pass an actual parameter for buffer - -- that is big enough for any full path name. Use + -- that is big enough for any full path name. Use -- max_path_len given below as the size of buffer. max_path_len : integer; -- Maximum length of an allowable full path name on the @@ -10037,19 +10174,19 @@ operations. @end smallexample In each of these five packages, the @code{C_Stream} function obtains the -@code{FILE} pointer from a currently opened Ada file. It is then +@code{FILE} pointer from a currently opened Ada file. It is then possible to use the @code{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 +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 -stream used by an Ada file. In the absence of such a call the standard +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 -existing C Stream instead of a file name. Typically this stream is +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. @@ -10059,21 +10196,21 @@ existing C file. @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 +which is made available to GNAT users. The packages described here are fully supported, and upwards compatibility will be maintained in future releases, so you can use these facilities with the confidence that the same functionality will be available in future releases. The chapter here simply gives a brief summary of the facilities available. -The full documentation is found in the spec file for the package. The full +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 +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 g-spipat.ads file in the library. +extensive examples, look in the @file{g-spipat.ads} file in the library. For each entry here, the package name (as it would appear in a @code{with} clause) is given, followed by the name of the corresponding spec file in -parentheses. The packages are children in four hierarchies, @code{Ada}, +parentheses. The packages are children in four hierarchies, @code{Ada}, @code{Interfaces}, @code{System}, and @code{GNAT}, the latter being a GNAT-specific hierarchy. @@ -10081,13 +10218,15 @@ 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 +should not be directly @code{with}'ed by application code. The use of a @code{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.Command_Line.Remove (a-colire.ads):: * Ada.Direct_IO.C_Streams (a-diocst.ads):: * Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads):: @@ -10122,6 +10261,7 @@ of GNAT, and will generate a warning message. * GNAT.IO (g-io.ads):: * GNAT.IO_Aux (g-io_aux.ads):: * GNAT.Lock_Files (g-locfil.ads):: +* GNAT.MD5 (g-md5.ads):: * GNAT.Most_Recent_Exception (g-moreex.ads):: * GNAT.OS_Lib (g-os_lib.ads):: * GNAT.Regexp (g-regexp.ads):: @@ -10149,6 +10289,7 @@ of GNAT, and will generate a warning message. * Interfaces.Os2lib.Threads (i-os2thr.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.Partition_Interface (s-parint.ads):: @@ -10157,48 +10298,76 @@ of GNAT, and will generate a warning message. * 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 + +@noindent +This child of @code{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} +The provision of such a package +is specifically authorized by the Ada Reference Manual +(RM A.3(27)). + @node Ada.Characters.Wide_Latin_1 (a-cwila1.ads) -@section Ada.Characters.Wide_Latin_1 (a-cwila1.ads) -@cindex Ada.Characters.Wide_Latin_1 (a-cwila1.ads) -@cindex Latin_1 constants for Wide_Character +@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 @noindent This child of @code{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 +instead of @code{Character}. The provision of such a package +is specifically authorized by the Ada Reference Manual +(RM A.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 + +@noindent +This child of @code{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 is specifically authorized by the Ada Reference Manual (RM A.3(27)). @node Ada.Command_Line.Remove (a-colire.ads) -@section Ada.Command_Line.Remove (a-colire.ads) -@cindex Ada.Command_Line.Remove (a-colire.ads) -@cindex Removing command line arguments -@cindex Command line, argument removal +@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 @noindent This child of @code{Ada.Command_Line} provides a mechanism for logically removing -arguments from the argument list. Once removed, an argument is not visible +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 see the removed argument. @node Ada.Direct_IO.C_Streams (a-diocst.ads) -@section Ada.Direct_IO.C_Streams (a-diocst.ads) -@cindex Ada.Direct_IO.C_Streams (a-diocst.ads) -@cindex C Streams, Interfacing with Direct_IO +@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 @noindent This package provides subprograms that allow interfacing between -C streams and @code{Direct_IO}. The stream identifier can be +C streams and @code{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 Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads) -@cindex Ada.Exceptions.Is_Null_Occurrence (a-einuoc.ads) -@cindex Null_Occurrence, testing for +@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 @noindent This child subprogram provides a way of testing for the null @@ -10206,32 +10375,32 @@ exception occurrence (@code{Null_Occurrence}) without raising an exception. @node Ada.Sequential_IO.C_Streams (a-siocst.ads) -@section Ada.Sequential_IO.C_Streams (a-siocst.ads) -@cindex Ada.Sequential_IO.C_Streams (a-siocst.ads) -@cindex C Streams, Interfacing with Sequential_IO +@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 @noindent This package provides subprograms that allow interfacing between -C streams and @code{Sequential_IO}. The stream identifier can be +C streams and @code{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 Ada.Streams.Stream_IO.C_Streams (a-ssicst.ads) -@cindex Ada.Streams.Stream_IO.C_Streams (a-ssicst.ads) -@cindex C Streams, Interfacing with Stream_IO +@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 @noindent This package provides subprograms that allow interfacing between -C streams and @code{Stream_IO}. The stream identifier can be +C streams and @code{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 Ada.Strings.Unbounded.Text_IO (a-suteio.ads) -@cindex Ada.Strings.Unbounded.Text_IO (a-suteio.ads) -@cindex Unbounded_String, IO support -@cindex Text_IO, extensions for unbounded strings +@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 @noindent This package provides subprograms for Text_IO for unbounded @@ -10239,10 +10408,10 @@ strings, avoiding the necessity for an intermediate operation with ordinary strings. @node Ada.Strings.Wide_Unbounded.Wide_Text_IO (a-swuwti.ads) -@section Ada.Strings.Wide_Unbounded.Wide_Text_IO (a-swuwti.ads) -@cindex Ada.Strings.Wide_Unbounded.Wide_Text_IO (a-swuwti.ads) -@cindex Unbounded_Wide_String, IO support -@cindex Text_IO, extensions for unbounded wide strings +@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 @noindent This package provides subprograms for Text_IO for unbounded @@ -10250,51 +10419,54 @@ wide strings, avoiding the necessity for an intermediate operation with ordinary wide strings. @node Ada.Text_IO.C_Streams (a-tiocst.ads) -@section Ada.Text_IO.C_Streams (a-tiocst.ads) -@cindex Ada.Text_IO.C_Streams (a-tiocst.ads) -@cindex C Streams, Interfacing with Text_IO +@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} @noindent This package provides subprograms that allow interfacing between -C streams and @code{Text_IO}. The stream identifier can be +C streams and @code{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.C_Streams (a-wtcstr.ads) -@section Ada.Wide_Text_IO.C_Streams (a-wtcstr.ads) -@cindex Ada.Wide_Text_IO.C_Streams (a-wtcstr.ads) -@cindex C Streams, Interfacing with Wide_Text_IO +@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} @noindent This package provides subprograms that allow interfacing between -C streams and @code{Wide_Text_IO}. The stream identifier can be +C streams and @code{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 GNAT.AWK (g-awk.ads) -@section GNAT.AWK (g-awk.ads) -@cindex 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 @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 +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.Bubble_Sort_A (g-busora.ads) -@section GNAT.Bubble_Sort_A (g-busora.ads) -@cindex 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 @noindent Provides a general implementation of bubble sort usable for sorting arbitrary -data items. Move and comparison procedures are provided by passing +data items. Move and comparison procedures are provided by passing access-to-procedure values. @node GNAT.Bubble_Sort_G (g-busorg.ads) -@section GNAT.Bubble_Sort_G (g-busorg.ads) -@cindex 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 @noindent Similar to @code{Bubble_Sort_A} except that the move and sorting procedures @@ -10303,9 +10475,9 @@ if the procedures can be inlined, at the expense of duplicating code for multiple instantiations. @node GNAT.Calendar (g-calend.ads) -@section GNAT.Calendar (g-calend.ads) -@cindex GNAT.Calendar (g-calend.ads) -@cindex Calendar +@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 @@ -10314,30 +10486,32 @@ 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 GNAT.Calendar.Time_IO (g-catiio.ads) -@cindex Calendar +@section @code{GNAT.Calendar.Time_IO} (@file{g-catiio.ads}) +@cindex @code{Calendar} @cindex Time -@cindex GNAT.Calendar.Time_IO (g-catiio.ads) +@cindex @code{GNAT.Calendar.Time_IO} (@file{g-catiio.ads}) @node GNAT.CRC32 (g-crc32.ads) -@section GNAT.CRC32 (g-crc32.ads) -@cindex 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 @noindent -This package implements the CRC-32 algorithm. For a full description +This package implements the CRC-32 algorithm. For a full description of this algorithm you should have a look at: -"Computation of Cyclic Redundancy Checks via Table Look-Up", Communications -of the ACM, Vol.@: 31 No.@: 8, pp.1008-1013 Aug.@: 1988. Sarwate, D.V@. +``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@. @noindent Provides an extended capability for formatted output of time values with -full user control over the format. Modeled on the GNU Date specification. +full user control over the format. Modeled on the GNU Date specification. @node GNAT.Case_Util (g-casuti.ads) -@section GNAT.Case_Util (g-casuti.ads) -@cindex 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 A set of simple routines for handling upper and lower casing of strings @@ -10345,30 +10519,31 @@ without the overhead of the full casing tables in @code{Ada.Characters.Handling}. @node GNAT.CGI (g-cgi.ads) -@section GNAT.CGI (g-cgi.ads) -@cindex 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 This is a package for interfacing a GNAT program with a Web server via the -Common Gateway Interface (CGI). Basically this package parse the CGI -parameters which are a set of key/value pairs sent by the Web server. It +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 GNAT.CGI.Cookie (g-cgicoo.ads) -@cindex GNAT.CGI.Cookie (g-cgicoo.ads) -@cindex CGI (Common Gateway Interface) Cookie support +@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 @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 +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 GNAT.CGI.Debug (g-cgideb.ads) -@cindex 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 @noindent @@ -10376,8 +10551,8 @@ This is a package to help debugging CGI (Common Gateway Interface) programs written in Ada. @node GNAT.Command_Line (g-comlin.ads) -@section GNAT.Command_Line (g-comlin.ads) -@cindex 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 @noindent @@ -10386,30 +10561,32 @@ including the ability to scan for named switches with optional parameters and expand file names using wild card notations. @node GNAT.Current_Exception (g-curexc.ads) -@section GNAT.Current_Exception (g-curexc.ads) -@cindex 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 @noindent Provides access to information on the current exception that has been raised without the need for using the Ada-95 exception choice parameter specification -syntax. This is particularly useful in mimicking typical facilities for +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 GNAT.Debug_Pools (g-debpoo.ads) -@cindex 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 @noindent Provide a debugging storage pools that helps tracking memory corruption -problems. See section "Finding memory problems with GNAT Debug Pool" in -the GNAT User's guide. +problems. See section ``Finding memory problems with GNAT Debug Pool'' in +the @cite{GNAT User's Guide}. @node GNAT.Debug_Utilities (g-debuti.ads) -@section GNAT.Debug_Utilities (g-debuti.ads) -@cindex 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 @@ -10417,8 +10594,8 @@ Provides a few useful utilities for debugging purposes, including conversion to and from string images of address values. @node GNAT.Directory_Operations (g-dirope.ads) -@section GNAT.Directory_Operations (g-dirope.ads) -@cindex GNAT.Directory_Operations (g-dirope.ads) +@section @code{GNAT.Directory_Operations} (g-dirope.ads) +@cindex @code{GNAT.Directory_Operations} (g-dirope.ads) @cindex Directory operations @noindent @@ -10427,8 +10604,8 @@ the current directory, making new directories, and scanning the files in a directory. @node GNAT.Dynamic_Tables (g-dyntab.ads) -@section GNAT.Dynamic_Tables (g-dyntab.ads) -@cindex 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 @@ -10443,8 +10620,8 @@ instances of the table, while an instantiation of GNAT.Table creates a single instance of the table type. @node GNAT.Exception_Traces (g-exctra.ads) -@section GNAT.Exception_Traces (g-exctra.ads) -@cindex 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 @@ -10453,8 +10630,8 @@ Provides an interface allowing to control automatic output upon exception occurrences. @node GNAT.Expect (g-expect.ads) -@section GNAT.Expect (g-expect.ads) -@cindex GNAT.Expect (g-expect.ads) +@section @code{GNAT.Expect} (@file{g-expect.ads}) +@cindex @code{GNAT.Expect} (@file{g-expect.ads}) @noindent Provides a set of subprograms similar to what is available @@ -10463,34 +10640,34 @@ 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 GNAT.Expect is implemented on all native GNAT ports except for -OpenVMS@. It is not implemented for cross ports, and in particular is not +OpenVMS@. It is not implemented for cross ports, and in particular is not implemented for VxWorks or LynxOS@. @node GNAT.Float_Control (g-flocon.ads) -@section GNAT.Float_Control (g-flocon.ads) -@cindex 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 Provides an interface for resetting the floating-point processor into the -mode required for correct semantic operation in Ada. Some third party +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.Heap_Sort_A (g-hesora.ads) -@section GNAT.Heap_Sort_A (g-hesora.ads) -@cindex 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 @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 +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. @node GNAT.Heap_Sort_G (g-hesorg.ads) -@section GNAT.Heap_Sort_G (g-hesorg.ads) -@cindex 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 @noindent @@ -10500,18 +10677,18 @@ if the procedures can be inlined, at the expense of duplicating code for multiple instantiations. @node GNAT.HTable (g-htable.ads) -@section GNAT.HTable (g-htable.ads) -@cindex GNAT.HTable (g-htable.ads) +@section @code{GNAT.HTable} (@file{g-htable.ads}) +@cindex @code{GNAT.HTable} (@file{g-htable.ads}) @cindex 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 +data. Provides two approaches, one a simple static approach, and the other allowing arbitrary dynamic hash tables. @node GNAT.IO (g-io.ads) -@section GNAT.IO (g-io.ads) -@cindex 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 @@ -10522,8 +10699,8 @@ Standard_Input, and writing characters, strings and integers to either Standard_Output or Standard_Error. @node GNAT.IO_Aux (g-io_aux.ads) -@section GNAT.IO_Aux (g-io_aux.ads) -@cindex 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 @@ -10531,28 +10708,36 @@ 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 GNAT.Lock_Files (g-locfil.ads) -@cindex 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 @noindent -Provides a general interface for using files as locks. Can be used for +Provides a general interface for using files as locks. Can be used for providing program level synchronization. +@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 + +@noindent +Implements the MD5 Message-Digest Algorithm as described in RFC 1321. + @node GNAT.Most_Recent_Exception (g-moreex.ads) -@section GNAT.Most_Recent_Exception (g-moreex.ads) -@cindex 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 @noindent -Provides access to the most recently raised exception. Can be used for +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 GNAT.OS_Lib (g-os_lib.ads) -@cindex 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 @@ -10563,31 +10748,31 @@ including a portable spawn procedure, and access to environment variables and error return codes. @node GNAT.Regexp (g-regexp.ads) -@section GNAT.Regexp (g-regexp.ads) -@cindex 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 @noindent A simple implementation of regular expressions, using a subset of regular -expression syntax copied from familiar Unix style utilities. This is the +expression syntax copied from familiar Unix style utilities. This is the simples 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) -@section GNAT.Registry (g-regist.ads) -@cindex GNAT.Registry (g-regist.ads) +@section @code{GNAT.Registry} (@file{g-regist.ads}) +@cindex @code{GNAT.Registry} (@file{g-regist.ads}) @cindex 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 +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 GNAT.Regpat (g-regpat.ads) -@cindex 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 @@ -10597,20 +10782,19 @@ from the original V7 style regular expression library written in C by Henry Spencer (and binary compatible with this C library). @node GNAT.Sockets (g-socket.ads) -@section GNAT.Sockets (g-socket.ads) -@cindex GNAT.Sockets (g-socket.ads) +@section @code{GNAT.Sockets} (@file{g-socket.ads}) +@cindex @code{GNAT.Sockets} (@file{g-socket.ads}) @cindex Sockets @noindent A high level and portable interface to develop sockets based applications. This package is based on the sockets thin binding found in GNAT.Sockets.Thin. Currently GNAT.Sockets 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@. +OpenVMS@. It is not implemented for the LynxOS@ cross port. @node GNAT.Source_Info (g-souinf.ads) -@section GNAT.Source_Info (g-souinf.ads) -@cindex 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 @noindent @@ -10618,8 +10802,8 @@ Provides subprograms that give access to source code information known at compile time, such as the current file name and line number. @node GNAT.Spell_Checker (g-speche.ads) -@section GNAT.Spell_Checker (g-speche.ads) -@cindex GNAT.Spell_Checker (g-speche.ads) +@section @code{GNAT.Spell_Checker} (@file{g-speche.ads}) +@cindex @code{GNAT.Spell_Checker} (@file{g-speche.ads}) @cindex Spell checking @noindent @@ -10627,20 +10811,20 @@ Provides a function for determining whether one string is a plausible near misspelling of another string. @node GNAT.Spitbol.Patterns (g-spipat.ads) -@section GNAT.Spitbol.Patterns (g-spipat.ads) -@cindex 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 @noindent -A complete implementation of SNOBOL4 style pattern matching. This is the -most elaborate of the pattern matching packages provided. It fully duplicates +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 GNAT.Spitbol (g-spitbo.ads) -@cindex GNAT.Spitbol (g-spitbo.ads) +@section @code{GNAT.Spitbol} (@file{g-spitbo.ads}) +@cindex @code{GNAT.Spitbol} (@file{g-spitbo.ads}) @cindex SPITBOL interface @noindent @@ -10651,8 +10835,8 @@ useful for constructing arbitrary mappings from strings in the style of the SNOBOL4 TABLE function. @node GNAT.Spitbol.Table_Boolean (g-sptabo.ads) -@section GNAT.Spitbol.Table_Boolean (g-sptabo.ads) -@cindex 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 @@ -10662,8 +10846,8 @@ for type @code{Standard.Boolean}, giving an implementation of sets of string values. @node GNAT.Spitbol.Table_Integer (g-sptain.ads) -@section GNAT.Spitbol.Table_Integer (g-sptain.ads) -@cindex 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 @@ -10674,8 +10858,8 @@ for type @code{Standard.Integer}, giving an implementation of maps from string to integer values. @node GNAT.Spitbol.Table_VString (g-sptavs.ads) -@section GNAT.Spitbol.Table_VString (g-sptavs.ads) -@cindex 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 @@ -10686,8 +10870,8 @@ a variable length string type, giving an implementation of general maps from strings to strings. @node GNAT.Table (g-table.ads) -@section GNAT.Table (g-table.ads) -@cindex 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 @@ -10702,33 +10886,33 @@ while an instantiation of 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 GNAT.Task_Lock (g-tasloc.ads) -@cindex 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 @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 +single global task lock. Appropriate for use in situations where contention between tasks is very rarely expected. @node GNAT.Threads (g-thread.ads) -@section GNAT.Threads (g-thread.ads) -@cindex 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 @noindent Provides facilities for creating and destroying threads with explicit calls. -These threads are known to the GNAT run-time system. These subprograms are +These threads are known to the GNAT run-time system. These subprograms are exported C-convention procedures intended to be called from foreign code. By using these primitives rather than directly calling operating systems routines, compatibility with the Ada tasking runt-time is provided. @node GNAT.Traceback (g-traceb.ads) -@section GNAT.Traceback (g-traceb.ads) -@cindex 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 @noindent @@ -10736,8 +10920,8 @@ Provides a facility for obtaining non-symbolic traceback information, useful in various debugging situations. @node GNAT.Traceback.Symbolic (g-trasym.ads) -@section GNAT.Traceback.Symbolic (g-trasym.ads) -@cindex 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 @noindent @@ -10745,8 +10929,8 @@ Provides symbolic traceback information that includes the subprogram name and line number information. @node Interfaces.C.Extensions (i-cexten.ads) -@section Interfaces.C.Extensions (i-cexten.ads) -@cindex Interfaces.C.Extensions (i-cexten.ads) +@section @code{Interfaces.C.Extensions} (@file{i-cexten.ads}) +@cindex @code{Interfaces.C.Extensions} (@file{i-cexten.ads}) @noindent This package contains additional C-related definitions, intended @@ -10754,8 +10938,8 @@ for use with either manually or automatically generated bindings to C libraries. @node Interfaces.C.Streams (i-cstrea.ads) -@section Interfaces.C.Streams (i-cstrea.ads) -@cindex 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 @noindent @@ -10763,19 +10947,19 @@ This package is a binding for the most commonly used operations on C streams. @node Interfaces.CPP (i-cpp.ads) -@section Interfaces.CPP (i-cpp.ads) -@cindex Interfaces.CPP (i-cpp.ads) +@section @code{Interfaces.CPP} (@file{i-cpp.ads}) +@cindex @code{Interfaces.CPP} (@file{i-cpp.ads}) @cindex C++ interfacing @cindex Interfacing, to C++ @noindent -This package provides facilities for use in interfacing to C++. It +This package provides facilities for use in interfacing to C++. It is primarily intended to be used in connection with automated tools for the generation of C++ interfaces. @node Interfaces.Os2lib (i-os2lib.ads) -@section Interfaces.Os2lib (i-os2lib.ads) -@cindex Interfaces.Os2lib (i-os2lib.ads) +@section @code{Interfaces.Os2lib} (@file{i-os2lib.ads}) +@cindex @code{Interfaces.Os2lib} (@file{i-os2lib.ads}) @cindex Interfacing, to OS/2 @cindex OS/2 interfacing @@ -10785,8 +10969,8 @@ It is a thin binding which is a direct translation of the various @file{<bse@.h>} files. @node Interfaces.Os2lib.Errors (i-os2err.ads) -@section Interfaces.Os2lib.Errors (i-os2err.ads) -@cindex Interfaces.Os2lib.Errors (i-os2err.ads) +@section @code{Interfaces.Os2lib.Errors} (@file{i-os2err.ads}) +@cindex @code{Interfaces.Os2lib.Errors} (@file{i-os2err.ads}) @cindex OS/2 Error codes @cindex Interfacing, to OS/2 @cindex OS/2 interfacing @@ -10795,8 +10979,8 @@ various @file{<bse@.h>} files. This package provides definitions of the OS/2 error codes. @node Interfaces.Os2lib.Synchronization (i-os2syn.ads) -@section Interfaces.Os2lib.Synchronization (i-os2syn.ads) -@cindex Interfaces.Os2lib.Synchronization (i-os2syn.ads) +@section @code{Interfaces.Os2lib.Synchronization} (@file{i-os2syn.ads}) +@cindex @code{Interfaces.Os2lib.Synchronization} (@file{i-os2syn.ads}) @cindex Interfacing, to OS/2 @cindex Synchronization, OS/2 @cindex OS/2 synchronization primitives @@ -10806,8 +10990,8 @@ This is a child package that provides definitions for interfacing to the @code{OS/2} synchronization primitives. @node Interfaces.Os2lib.Threads (i-os2thr.ads) -@section Interfaces.Os2lib.Threads (i-os2thr.ads) -@cindex Interfaces.Os2lib.Threads (i-os2thr.ads) +@section @code{Interfaces.Os2lib.Threads} (@file{i-os2thr.ads}) +@cindex @code{Interfaces.Os2lib.Threads} (@file{i-os2thr.ads}) @cindex Interfacing, to OS/2 @cindex Thread control, OS/2 @cindex OS/2 thread interfacing @@ -10817,8 +11001,8 @@ This is a child package that provides definitions for interfacing to the @code{OS/2} thread primitives. @node Interfaces.Packed_Decimal (i-pacdec.ads) -@section Interfaces.Packed_Decimal (i-pacdec.ads) -@cindex 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 @@ -10828,19 +11012,31 @@ from a packed decimal format compatible with that used on IBM mainframes. @node Interfaces.VxWorks (i-vxwork.ads) -@section Interfaces.VxWorks (i-vxwork.ads) -@cindex 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 @noindent -This package provides a limited binding to the VxWorks API +This package provides a limited binding to the VxWorks API. In particular, it interfaces with the -VxWorks hardware interrupt facilities +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 + +@noindent +This package provides a limited binding to the VxWorks' I/O API. +In particular, it provides procedures that enable the use of +Get_Immediate under VxWorks. @node System.Address_Image (s-addima.ads) -@section System.Address_Image (s-addima.ads) -@cindex 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 @@ -10850,10 +11046,10 @@ function that gives an (implementation dependent) string which identifies an address. @node System.Assertions (s-assert.ads) -@section System.Assertions (s-assert.ads) -@cindex System.Assertions (s-assert.ads) -@cindex Assertions -@cindex Assert_Failure, exception +@section @code{System.Assertions} (@file{s-assert.ads}) +@cindex @code{System.Assertions} (@file{s-assert.ads}) +@cindex Assertions +@cindex Assert_Failure, exception @noindent This package provides the declaration of the exception raised @@ -10861,27 +11057,27 @@ by an run-time assertion failure, as well as the routine that is used internally to raise this assertion. @node System.Partition_Interface (s-parint.ads) -@section System.Partition_Interface (s-parint.ads) -@cindex 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 intefacing functions @noindent -This package provides facilities for partition interfacing. It +This package provides facilities for partition interfacing. It is used primarily in a distribution context when using Annex E with @code{GLADE}. @node System.Task_Info (s-tasinf.ads) -@section System.Task_Info (s-tasinf.ads) -@cindex System.Task_Info (s-tasinf.ads) -@cindex Task_Info pragma +@section @code{System.Task_Info} (@file{s-tasinf.ads}) +@cindex @code{System.Task_Info} (@file{s-tasinf.ads}) +@cindex Task_Info pragma @noindent This package provides target dependent functionality that is used to support the @code{Task_Info} pragma @node System.Wch_Cnv (s-wchcnv.ads) -@section System.Wch_Cnv (s-wchcnv.ads) -@cindex 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 @@ -10890,17 +11086,17 @@ to support the @code{Task_Info} pragma This package provides routines for converting between wide characters and a representation as a value of type @code{Standard.String}, using a specified wide character -encoding method. Uses definitions in -package @code{System.Wch_Con} +encoding method. It uses definitions in +package @code{System.Wch_Con}. @node System.Wch_Con (s-wchcon.ads) -@section System.Wch_Con (s-wchcon.ads) -@cindex System.Wch_Con (s-wchcon.ads) +@section @code{System.Wch_Con} (@file{s-wchcon.ads}) +@cindex @code{System.Wch_Con} (@file{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 +in ordinary strings. These definitions are used by the package @code{System.Wch_Cnv}. @node Interfacing to Other Languages @@ -10928,14 +11124,14 @@ Interfacing to C with GNAT can use one of two approaches: @item The types in the package @code{Interfaces.C} may be used. @item -Standard Ada types may be used directly. This may be less portable to +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 enumerate @noindent Pragma @code{Convention C} maybe applied to Ada types, but mostly has no -effect, since this is the default. The following table shows the +effect, since this is the default. The following table shows the correspondence between Ada scalar types and the corresponding C types. @table @code @@ -10963,9 +11159,9 @@ This is the longest floating-point type supported by the hardware. @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 signed char, short, int respectively) -depending on the number of values passed. This is the only case in which +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 representation of an Ada type. @item @@ -10989,7 +11185,7 @@ of the length corresponding to the @code{@var{type}'Size} value in Ada. @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. Ada Core +tool, although it is possible to construct them by hand. Ada Core Technologies does not currently supply a suitable binding generator tool. Using these pragmas it is possible to achieve complete @@ -10999,7 +11195,7 @@ See @ref{Implementation Defined Pragmas} for more details. @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 +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. @@ -11025,15 +11221,15 @@ the Ada 95 reference manual. @noindent Interfacing to Fortran is achieved as described in section B.5 of the -reference manual. The pragma @code{Convention Fortran}, applied to a -multi- dimensional array causes the array to be stored in column-major +reference manual. The pragma @code{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 @section Interfacing to non-GNAT Ada code -It is possible to specify the convention Ada in a pragma Import or -pragma Export. However this refers to the calling conventions used +It is possible to specify the convention @code{Ada} in a pragma @code{Import} or +pragma @code{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 or Ada 95 compiler to allow interoperation. @@ -11066,15 +11262,16 @@ including machine instructions in a subprogram. @end itemize The two features are similar, and both closely related to the mechanism -provided by the asm instruction in the GNU C compiler. Full understanding +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 as described in @cite{Using and Porting GNU CC} by Richard +instruction as described in +@cite{Using and Porting the GNU Compiler Collection (GCC)} by Richard Stallman. Calls to the function @code{Asm} and the procedure @code{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. -The first example given in the GNU CC documentation is the C @code{asm} +The first example given in the GCC documentation is the C @code{asm} instruction: @smallexample asm ("fsinx %1 %0" : "=f" (result) : "f" (angle)); @@ -11090,19 +11287,19 @@ Asm ("fsinx %1 %0", @end smallexample The first argument to @code{Asm} is the assembler template, and is -identical to what is used in GNU CC@. This string must be a static -expression. The second argument is the output operand list. It 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 references enclosed in parentheses (technically an array aggregate of such references). The @code{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) +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 -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 +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}. @@ -11112,39 +11309,39 @@ though it were an @code{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 +operands. It is either a single @code{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 parameters. The first is a string, the second is an expression of the -type designated by the prefix. The first (string) argument is required +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 -value to be used as the input argument. The possible values for 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. If there are no input operands, this argument may either be omitted, or explicitly given as @code{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 +@dfn{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 @code{Asm} call. If this argument is the null string (the default value), then the code generator assumes that no additional registers are destroyed. The fifth argument, not present in the above example, called the -@dfn{volatile} argument, is by default @code{False}. It can be set to +@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 optimizations with respect to the instruction specified should be suppressed, and that in particular, for an instruction that has outputs, the instruction will still be generated, even if none of the outputs are -used. See the full description in the GCC manual for further details. +used. See the full description in the GCC manual for further details. -The @code{Asm} subprograms may be used in two ways. First the procedure +The @code{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 @@ -11161,7 +11358,7 @@ within subprograms whose entire body consists of such statements. It is 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 +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} (of course if named notation is used, the arguments may be given in arbitrary order, following the @@ -11206,27 +11403,25 @@ GNAT run-time system comprises two layers: @end itemize 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. 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 +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@. 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 underlying kernel. Otherwise, some target dependent glue code maps the services offered by the underlying kernel to the semantics expected by GNARL@. Whatever the underlying OS (VxWorks, UNIX, OS/2, Windows NT, etc.) the key point is that each Ada task is mapped on a thread in the underlying -kernel. For example, in the case of VxWorks - - 1 Ada task = 1 VxWorks task +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: @@ -11234,7 +11429,7 @@ Mapping Ada tasks onto the underlying kernel threads has several advantages: @enumerate @item -The underlying scheduler is used to schedule the Ada tasks. This +The underlying scheduler is used to schedule the Ada tasks. This makes Ada tasks as efficient as kernel threads from a scheduling standpoint. @@ -11284,11 +11479,11 @@ The GNAT run-time, has a nice cooperative solution to this problem which ensures that accurate FIFO_Within_Priorities semantics are respected. -The principle is as follows. When an Ada task T is about to start +The principle is as follows. When an Ada task T is about to start running, it checks whether some other Ada task R with the same priority as T has been suspended due to the loss of priority -inheritance. If this is the case, T yields and is placed at the end of -its priority queue. When R arrives at the front of the queue it +inheritance. If this is the case, T yields and is placed at the end of +its priority queue. When R arrives at the front of the queue it executes. Note that this simple scheme preserves the relative order of the tasks @@ -11307,20 +11502,20 @@ placed at the end. @end menu Aggregate 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 +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 -statements and multiple assignments. In the simplest cases, however, the +statements and multiple assignments. In the simplest cases, however, the compiler will recognize aggregates whose components and constraints are fully static, and in those cases the compiler will generate little or no -executable code. The following is an outline of the code that GNAT generates -for various aggregate constructs. For further details, the user will find it +executable code. The following is an outline of the code that GNAT generates +for various aggregate constructs. For further details, the user will find it useful to examine the output produced by the -gnatG flag to see the expanded source that is input to the code generator. The user will also want to examine the assembly code generated at various levels of optimization. The code generated for aggregates depends on the context, the component values, -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 +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 @@ -11358,7 +11553,7 @@ None2 : constant ar_ar := (1..3 => None); -- fully static @end smallexample However, for multidimensional aggregates with named associations, GNAT will -generate assignments and loops, even if all associations are static. The +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: @@ -11371,8 +11566,8 @@ Zero2: constant two_dim := (others => (others => 0)); @section Constant aggregates with an unconstrained nominal types In such cases the aggregate itself establishes the subtype, so that associations -with "others" cannot be used. GNAT determines the bounds for the actual -subtype of the aggregate, and allocates the aggregate statically as well. No +with @code{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 @@ -11384,9 +11579,9 @@ code is generated for the following: @section Aggregates with static bounds 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 +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 +object. The declarations @smallexample Cr_Var1 : One_Dim := (2, 5, 7, 11); @@ -11411,7 +11606,7 @@ generate the equivalent of 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 +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. @@ -11419,9 +11614,9 @@ compatible subtypes. @section Aggregates in assignments statements 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 +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: +component assignments. For example, consider the simple case: @smallexample @end smallexample @@ -11435,9 +11630,9 @@ This cannot be converted into: @end smallexample 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 +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: +into the target. The following sufficient criteria are applied: @enumerate @item The bounds of the aggregate are static, and the associations are static. @@ -11456,30 +11651,30 @@ that temporary will be copied onto the target. @noindent Ada 95 defines a number of specialized needs annexes, which are not -required in all implementations. However, as described in this chapter, +required in all implementations. However, as described in this chapter, GNAT implements all of these special needs annexes: @table @asis @item Systems Programming (Annex C) -The systems programming annex is fully implemented. +The Systems Programming Annex is fully implemented. @item Real-Time Systems (Annex D) -The real-time systems annex is fully implemented. +The Real-Time Systems Annex is fully implemented. @item Distributed Systems (Annex E) -Stub generation is fully implemented in the @code{GNAT} compiler. In addition, -a complete compatible PCS is available as part of the @code{GLADE} system, -a separate product available from Ada Core Technologies. When the two +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) -The information systems annex is fully implemented. +The Information Systems annex is fully implemented. @item Numerics (Annex G) -The numerics annex is fully implemented. +The Numerics Annex is fully implemented. @item Safety and Security (Annex H) -The safety and security annex is fully implemented. +The Safety and Security annex is fully implemented. @end table @@ -11500,15 +11695,16 @@ applications developed in other Ada environments. @node Compatibility with Ada 83 @section Compatibility with Ada 83 +@cindex Compatibility (between Ada 83 and Ada 95) @noindent -Ada 95 is designed to be highly upwards compatible with Ada 83. In +Ada 95 is designed to be highly upwards compatible with Ada 83. In particular, the design intention is that the difficulties associated with moving from Ada 83 to Ada 95 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 Ada 95 Annotated Reference Manual contains +incompatibilities. The Ada 95 Annotated Reference Manual contains full details of these issues, and should be consulted for a complete treatment. In practice the @@ -11516,12 +11712,13 @@ following are the most likely issues to be encountered. @table @asis @item Character range -The range of Standard.Character is now the full 256 characters of Latin-1, +The range of @code{Standard.Character} is now the full 256 characters of Latin-1, whereas in most Ada 83 implementations it was restricted to 128 characters. -This may show up as compile time or runtime errors. The desirable fix is to +This may show up as compile time or runtime errors. The desirable fix is to adapt 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. +@cindex Latin-1 @item New reserved words The identifiers @code{abstract}, @code{aliased}, @code{protected}, @@ -11532,55 +11729,55 @@ use some alternative name. @item 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 +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 (including the -extended DEC Ada 83 compatibility pragmas such as Export_Procedure), cannot -be applied to a subprogram body. If necessary, a separate subprogram +extended DEC Ada 83 compatibility pragmas such as @code{Export_Procedure}), cannot +be applied to a subprogram body. If necessary, a separate subprogram declaration must be introduced to which the pragma can be applied. @item 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). In +allowed to have one. This lead to certain surprises in compiling large +systems (situations in which the body could be unexpectedly ignored). 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 +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 +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 Requires_Body, which must then be given a dummy procedure body in the package body, which then becomes required. -@item Numeric_Error is now the same as Constraint_Error -In Ada 95, the exception Numeric_Error is a renaming of Constraint_Error. +@item @code{Numeric_Error} is now the same as @code{Constraint_Error} +In Ada 95, the exception @code{Numeric_Error} is a renaming of @code{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 -Numeric_Error case (since even in Ada 83, a compiler was free to raise -Constraint_Error in place of Numeric_Error in all cases). +the two exceptions. The fix is simply to remove the handler for the +@code{Numeric_Error} case (since even in Ada 83, a compiler was free to raise +@code{Constraint_Error} in place of @code{Numeric_Error} in all cases). @item Indefinite subtypes in generics -In Ada 83, it was permissible to pass an indefinite type (e.g.@: String) as +In Ada 83, it was permissible to pass an indefinite type (e.g.@: @code{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 this type in the generic body. In Ada 95, to avoid this clear violation of the contract model, the generic declaration clearly indicates whether -or not such instantiations are permitted. If a generic formal parameter -has explicit unknown discriminants, indicated by using (<>) after the +or not such instantiations are permitted. If a generic formal parameter +has explicit unknown discriminants, indicated by using @code{(<>)} after the type name, then it can be instantiated with indefinite types, but no -variables can be declared of this type. Any attempt to declare a variable -will result in an illegality at the time the generic is declared. If the -(<>) notation is not used, then it is illegal to instantiate the generic -with an indefinite type. This will show up as a compile time error, and -the fix is usually simply to add the (<>) to the generic declaration. +variables can be declared of this type. Any attempt to declare a variable +will result in an illegality at the time the generic is declared. If the +@code{(<>)} notation is not used, then it is illegal to instantiate the generic +with an indefinite type. This will show up as a compile time error, and +the fix is usually simply to add the @code{(<>)} to the generic declaration. @end table 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 Ada 95 protected keywords are not recognized in this mode. However, +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 Ada 95 protected keywords are not recognized in this mode. However, in practice, it is usually advisable to make the necessary modifications to the program to remove the need for using this switch. @@ -11591,7 +11788,7 @@ to the program to remove the need for using this switch. Providing that programs avoid the use of implementation dependent and implementation defined features of Ada 95, as documented in the Ada 95 reference manual, there should be a high degree of portability between -GNAT and other Ada 95 systems. The following are specific items which +GNAT and other Ada 95 systems. The following are specific items which have proved troublesome in moving GNAT programs to other Ada 95 compilers, but do not affect porting code to GNAT@. @@ -11604,14 +11801,14 @@ a compatibility concern, but some other Ada 95 compilers reject these pragmas and attributes. @item Special-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 +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 Representation Clauses Some other Ada 95 compilers implement only the minimal set of -representation clauses required by the Ada 95 reference manual. GNAT goes +representation clauses required by the Ada 95 reference manual. GNAT goes far beyond this minimal set, as described in the next section. @end table @@ -11621,7 +11818,7 @@ far beyond this minimal set, as described in the next section. @noindent The Ada 83 reference manual was quite vague in describing both the minimal required implementation of representation clauses, and also their precise -effects. The Ada 95 reference manual is much more explicit, but the minimal +effects. The Ada 95 reference manual is much more explicit, but the minimal set of capabilities required in Ada 95 is quite limited. GNAT implements the full required set of capabilities described in the @@ -11630,15 +11827,15 @@ 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 -requirements in the Ada 95 reference manual. These are instances of +requirements in the Ada 95 reference manual. These are instances of intentional or accidental dependence on specific implementation dependent -characteristics of these Ada 83 compilers. The following is a list of +characteristics of these Ada 83 compilers. The following is a list of the cases most likely to arise in existing legacy Ada 83 code. @table @asis @item Implicit Packing Some Ada 83 compilers allowed a Size specification to cause implicit -packing of an array or record. This could cause expensive 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 @@ -11646,36 +11843,36 @@ change of representation in response to a Size clause is inadvisable, and this recommendation is represented explicitly in the Ada 95 RM 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 Pack, or for more fine tuned control, provide +message rejecting the size clause. The fix is simply to provide +the explicit pragma @code{Pack}, or for more fine tuned control, provide a Component_Size clause. @item Meaning of Size Attribute The Size attribute in Ada 95 for discrete types is defined as being the -minimal number of bits required to hold values of the type. For example, +minimal number of bits required to hold values of the type. For example, on a 32-bit machine, the size of 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 +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 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 +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", +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 +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 +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. +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: @smallexample @@ -11684,13 +11881,13 @@ for X'Size use Standard'Address_Size; @end smallexample @noindent -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 +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 +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 +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. @end table @@ -11701,29 +11898,29 @@ representation clause for an access field in a record. @noindent The VMS version of GNAT fully implements all the pragmas and attributes provided by DEC Ada 83, as well as providing the standard DEC Ada 83 -libraries, including Starlet. In addition, data layouts and parameter -passing conventions are highly compatible. This means that porting +libraries, including Starlet. In addition, data layouts and parameter +passing conventions are highly compatible. This means that porting existing DEC Ada 83 code to GNAT in VMS systems should be easier than -most other porting efforts. The following are some of the most +most other porting efforts. The following are some of the most significant differences between GNAT and DEC Ada 83. @table @asis @item Default floating-point representation In GNAT, the default floating-point format is IEEE, whereas in DEC Ada 83, -it is VMS format. GNAT does implement the necessary pragmas +it is VMS format. GNAT does implement the necessary pragmas (Long_Float, Float_Representation) for changing this default. @item 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 -DEC Ada 83 extensions. However, a separate package Aux_DEC is provided +DEC 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. @item To_Address The definitions provided by Aux_DEC are exactly compatible with those -in the DEC Ada 83 version of System, with one exception. DEC Ada provides +in the DEC Ada 83 version of System, with one exception. DEC Ada provides the following declarations: @smallexample @@ -11736,7 +11933,7 @@ TO_ADDRESS(universal_integer) The version of TO_ADDRESS taking a universal integer argument is in fact an extension to Ada 83 not strictly compatible with the reference manual. In GNAT, we are constrained to be exactly compatible with the standard, -and this means we cannot provide this capability. In DEC Ada 83, the +and this means we cannot provide this capability. In DEC Ada 83, the point of this definition is to deal with a call like: @smallexample @@ -11746,11 +11943,11 @@ point of this definition is to deal with a call like: @noindent Normally, according to the Ada 83 standard, one would expect this to be ambiguous, since it matches both the INTEGER and UNSIGNED_LONGWORD forms -of TO_ADDRESS@. However, in DEC Ada 83, there is no ambiguity, since the +of TO_ADDRESS@. However, in DEC Ada 83, there is no ambiguity, since the definition using universal_integer takes precedence. In GNAT, since the version with universal_integer cannot be supplied, it is -not possible to be 100% compatible. Since there are many programs using +not possible to be 100% compatible. Since there are many programs using numeric constants for the argument to TO_ADDRESS, the decision in GNAT was to change the name of the function in the UNSIGNED_LONGWORD case, so the declarations provided in the GNAT version of AUX_Dec are: @@ -11775,12 +11972,12 @@ which in GNAT is treated like any other declared task. @end table For full details on these and other less significant compatibility issues, -see appendix E of the Digital publication entitled "DEC Ada, Technical -Overview and Comparison on DIGITAL Platforms". +see appendix E of the Digital publication entitled @cite{DEC Ada, Technical +Overview and Comparison on DIGITAL Platforms}. For GNAT running on other than VMS systems, all the DEC Ada 83 pragmas and attributes are recognized, although only a subset of them can sensibly -be implemented. The description of pragmas in this reference manual +be implemented. The description of pragmas in this reference manual indicates whether or not they are applicable to non-VMS systems. @include gfdl.texi |