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diff --git a/gcc/ada/exp_ch9.adb b/gcc/ada/exp_ch9.adb new file mode 100644 index 0000000..31b5d12 --- /dev/null +++ b/gcc/ada/exp_ch9.adb @@ -0,0 +1,8543 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT COMPILER COMPONENTS -- +-- -- +-- E X P _ C H 9 -- +-- -- +-- B o d y -- +-- -- +-- $Revision: 1.438 $ +-- -- +-- Copyright (C) 1992-2001, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 2, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- +-- for more details. You should have received a copy of the GNU General -- +-- Public License distributed with GNAT; see file COPYING. If not, write -- +-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- +-- MA 02111-1307, USA. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- +-- -- +------------------------------------------------------------------------------ + +with Atree; use Atree; +with Checks; use Checks; +with Einfo; use Einfo; +with Elists; use Elists; +with Errout; use Errout; +with Exp_Ch3; use Exp_Ch3; +with Exp_Ch11; use Exp_Ch11; +with Exp_Ch6; use Exp_Ch6; +with Exp_Dbug; use Exp_Dbug; +with Exp_Smem; use Exp_Smem; +with Exp_Tss; use Exp_Tss; +with Exp_Util; use Exp_Util; +with Freeze; use Freeze; +with Hostparm; +with Namet; use Namet; +with Nlists; use Nlists; +with Nmake; use Nmake; +with Opt; use Opt; +with Restrict; use Restrict; +with Rtsfind; use Rtsfind; +with Sem; use Sem; +with Sem_Ch6; +with Sem_Ch8; use Sem_Ch8; +with Sem_Ch11; use Sem_Ch11; +with Sem_Elab; use Sem_Elab; +with Sem_Res; use Sem_Res; +with Sem_Util; use Sem_Util; +with Sinfo; use Sinfo; +with Snames; use Snames; +with Stand; use Stand; +with Tbuild; use Tbuild; +with Types; use Types; +with Uintp; use Uintp; +with Opt; + +package body Exp_Ch9 is + + ----------------------- + -- Local Subprograms -- + ----------------------- + + function Actual_Index_Expression + (Sloc : Source_Ptr; + Ent : Entity_Id; + Index : Node_Id; + Tsk : Entity_Id) + return Node_Id; + -- Compute the index position for an entry call. Tsk is the target + -- task. If the bounds of some entry family depend on discriminants, + -- the expression computed by this function uses the discriminants + -- of the target task. + + function Index_Constant_Declaration + (N : Node_Id; + Index_Id : Entity_Id; + Prot : Entity_Id) + return List_Id; + -- For an entry family and its barrier function, we define a local entity + -- that maps the index in the call into the entry index into the object: + -- + -- I : constant Index_Type := Index_Type'Val ( + -- E - <<index of first family member>> + + -- Protected_Entry_Index (Index_Type'Pos (Index_Type'First))); + + procedure Add_Object_Pointer + (Decls : List_Id; + Pid : Entity_Id; + Loc : Source_Ptr); + -- Prepend an object pointer declaration to the declaration list + -- Decls. This object pointer is initialized to a type conversion + -- of the System.Address pointer passed to entry barrier functions + -- and entry body procedures. + + function Array_Type (E : Entity_Id; Trec : Node_Id) return Entity_Id; + -- Find the array type associated with an entry family in the + -- associated record for the task type. + + function Build_Accept_Body (Astat : Node_Id) return Node_Id; + -- Transform accept statement into a block with added exception handler. + -- Used both for simple accept statements and for accept alternatives in + -- select statements. Astat is the accept statement. + + function Build_Barrier_Function + (N : Node_Id; + Ent : Entity_Id; + Pid : Node_Id) + return Node_Id; + -- Build the function body returning the value of the barrier expression + -- for the specified entry body. + + function Build_Barrier_Function_Specification + (Def_Id : Entity_Id; + Loc : Source_Ptr) + return Node_Id; + -- Build a specification for a function implementing + -- the protected entry barrier of the specified entry body. + + function Build_Corresponding_Record + (N : Node_Id; + Ctyp : Node_Id; + Loc : Source_Ptr) + return Node_Id; + -- Common to tasks and protected types. Copy discriminant specifications, + -- build record declaration. N is the type declaration, Ctyp is the + -- concurrent entity (task type or protected type). + + function Build_Entry_Count_Expression + (Concurrent_Type : Node_Id; + Component_List : List_Id; + Loc : Source_Ptr) + return Node_Id; + -- Compute number of entries for concurrent object. This is a count of + -- simple entries, followed by an expression that computes the length + -- of the range of each entry family. A single array with that size is + -- allocated for each concurrent object of the type. + + function Build_Find_Body_Index + (Typ : Entity_Id) + return Node_Id; + -- Build the function that translates the entry index in the call + -- (which depends on the size of entry families) into an index into the + -- Entry_Bodies_Array, to determine the body and barrier function used + -- in a protected entry call. A pointer to this function appears in every + -- protected object. + + function Build_Find_Body_Index_Spec + (Typ : Entity_Id) + return Node_Id; + -- Build subprogram declaration for previous one. + + function Build_Protected_Entry + (N : Node_Id; + Ent : Entity_Id; + Pid : Node_Id) + return Node_Id; + -- Build the procedure implementing the statement sequence of + -- the specified entry body. + + function Build_Protected_Entry_Specification + (Def_Id : Entity_Id; + Ent_Id : Entity_Id; + Loc : Source_Ptr) + return Node_Id; + -- Build a specification for a procedure implementing + -- the statement sequence of the specified entry body. + -- Add attributes associating it with the entry defining identifier + -- Ent_Id. + + function Build_Protected_Subprogram_Body + (N : Node_Id; + Pid : Node_Id; + N_Op_Spec : Node_Id) + return Node_Id; + -- This function is used to construct the protected version of a protected + -- subprogram. Its statement sequence first defers abortion, then locks + -- the associated protected object, and then enters a block that contains + -- a call to the unprotected version of the subprogram (for details, see + -- Build_Unprotected_Subprogram_Body). This block statement requires + -- a cleanup handler that unlocks the object in all cases. + -- (see Exp_Ch7.Expand_Cleanup_Actions). + + function Build_Protected_Spec + (N : Node_Id; + Obj_Type : Entity_Id; + Unprotected : Boolean := False; + Ident : Entity_Id) + return List_Id; + -- Utility shared by Build_Protected_Sub_Spec and Expand_Access_Protected_ + -- Subprogram_Type. Builds signature of protected subprogram, adding the + -- formal that corresponds to the object itself. For an access to protected + -- subprogram, there is no object type to specify, so the additional + -- parameter has type Address and mode In. An indirect call through such + -- a pointer converts the address to a reference to the actual object. + -- The object is a limited record and therefore a by_reference type. + + function Build_Selected_Name + (Prefix, Selector : Name_Id; + Append_Char : Character := ' ') + return Name_Id; + -- Build a name in the form of Prefix__Selector, with an optional + -- character appended. This is used for internal subprograms generated + -- for operations of protected types, including barrier functions. In + -- order to simplify the work of the debugger, the prefix includes the + -- characters PT. + + procedure Build_Simple_Entry_Call + (N : Node_Id; + Concval : Node_Id; + Ename : Node_Id; + Index : Node_Id); + -- Some comments here would be useful ??? + + function Build_Task_Proc_Specification (T : Entity_Id) return Node_Id; + -- This routine constructs a specification for the procedure that we will + -- build for the task body for task type T. The spec has the form: + -- + -- procedure tnameB (_Task : access tnameV); + -- + -- where name is the character name taken from the task type entity that + -- is passed as the argument to the procedure, and tnameV is the task + -- value type that is associated with the task type. + + function Build_Unprotected_Subprogram_Body + (N : Node_Id; + Pid : Node_Id) + return Node_Id; + -- This routine constructs the unprotected version of a protected + -- subprogram body, which is contains all of the code in the + -- original, unexpanded body. This is the version of the protected + -- subprogram that is called from all protected operations on the same + -- object, including the protected version of the same subprogram. + + procedure Collect_Entry_Families + (Loc : Source_Ptr; + Cdecls : List_Id; + Current_Node : in out Node_Id; + Conctyp : Entity_Id); + -- For each entry family in a concurrent type, create an anonymous array + -- type of the right size, and add a component to the corresponding_record. + + function Family_Offset + (Loc : Source_Ptr; + Hi : Node_Id; + Lo : Node_Id; + Ttyp : Entity_Id) + return Node_Id; + -- Compute (Hi - Lo) for two entry family indices. Hi is the index in + -- an accept statement, or the upper bound in the discrete subtype of + -- an entry declaration. Lo is the corresponding lower bound. Ttyp is + -- the concurrent type of the entry. + + function Family_Size + (Loc : Source_Ptr; + Hi : Node_Id; + Lo : Node_Id; + Ttyp : Entity_Id) + return Node_Id; + -- Compute (Hi - Lo) + 1 Max 0, to determine the number of entries in + -- a family, and handle properly the superflat case. This is equivalent + -- to the use of 'Length on the index type, but must use Family_Offset + -- to handle properly the case of bounds that depend on discriminants. + + procedure Extract_Entry + (N : Node_Id; + Concval : out Node_Id; + Ename : out Node_Id; + Index : out Node_Id); + -- Given an entry call, returns the associated concurrent object, + -- the entry name, and the entry family index. + + function Find_Task_Or_Protected_Pragma + (T : Node_Id; + P : Name_Id) + return Node_Id; + -- Searches the task or protected definition T for the first occurrence + -- of the pragma whose name is given by P. The caller has ensured that + -- the pragma is present in the task definition. A special case is that + -- when P is Name_uPriority, the call will also find Interrupt_Priority. + -- ??? Should be implemented with the rep item chain mechanism. + + procedure Update_Prival_Subtypes (N : Node_Id); + -- The actual subtypes of the privals will differ from the type of the + -- private declaration in the original protected type, if the protected + -- type has discriminants or if the prival has constrained components. + -- This is because the privals are generated out of sequence w.r.t. the + -- analysis of a protected body. After generating the bodies for protected + -- operations, we set correctly the type of all references to privals, by + -- means of a recursive tree traversal, which is heavy-handed but + -- correct. + + ----------------------------- + -- Actual_Index_Expression -- + ----------------------------- + + function Actual_Index_Expression + (Sloc : Source_Ptr; + Ent : Entity_Id; + Index : Node_Id; + Tsk : Entity_Id) + return Node_Id + is + Expr : Node_Id; + Num : Node_Id; + Lo : Node_Id; + Hi : Node_Id; + Prev : Entity_Id; + S : Node_Id; + Ttyp : Entity_Id := Etype (Tsk); + + -------------------------- + -- Actual_Family_Offset -- + -------------------------- + + function Actual_Family_Offset (Hi, Lo : Node_Id) return Node_Id; + -- Compute difference between bounds of entry family. + + function Actual_Family_Offset (Hi, Lo : Node_Id) return Node_Id is + + function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id; + -- Replace a reference to a discriminant with a selected component + -- denoting the discriminant of the target task. + + function Actual_Discriminant_Ref (Bound : Node_Id) return Node_Id is + Typ : Entity_Id := Etype (Bound); + B : Node_Id; + + begin + if not Is_Entity_Name (Bound) + or else Ekind (Entity (Bound)) /= E_Discriminant + then + if Nkind (Bound) = N_Attribute_Reference then + return Bound; + else + B := New_Copy_Tree (Bound); + end if; + + else + B := + Make_Selected_Component (Sloc, + Prefix => New_Copy_Tree (Tsk), + Selector_Name => New_Occurrence_Of (Entity (Bound), Sloc)); + + Analyze_And_Resolve (B, Typ); + end if; + + return + Make_Attribute_Reference (Sloc, + Attribute_Name => Name_Pos, + Prefix => New_Occurrence_Of (Etype (Bound), Sloc), + Expressions => New_List (B)); + end Actual_Discriminant_Ref; + + begin + return + Make_Op_Subtract (Sloc, + Left_Opnd => Actual_Discriminant_Ref (Hi), + Right_Opnd => Actual_Discriminant_Ref (Lo)); + end Actual_Family_Offset; + + begin + -- The queues of entries and entry families appear in textual + -- order in the associated record. The entry index is computed as + -- the sum of the number of queues for all entries that precede the + -- designated one, to which is added the index expression, if this + -- expression denotes a member of a family. + + -- The following is a place holder for the count of simple entries. + + Num := Make_Integer_Literal (Sloc, 1); + + -- We construct an expression which is a series of addition + -- operations. See comments in Entry_Index_Expression, which is + -- identical in structure. + + if Present (Index) then + S := Etype (Discrete_Subtype_Definition (Declaration_Node (Ent))); + + Expr := + Make_Op_Add (Sloc, + Left_Opnd => Num, + + Right_Opnd => + Actual_Family_Offset ( + Make_Attribute_Reference (Sloc, + Attribute_Name => Name_Pos, + Prefix => New_Reference_To (Base_Type (S), Sloc), + Expressions => New_List (Relocate_Node (Index))), + Type_Low_Bound (S))); + else + Expr := Num; + end if; + + -- Now add lengths of preceding entries and entry families. + + Prev := First_Entity (Ttyp); + + while Chars (Prev) /= Chars (Ent) + or else (Ekind (Prev) /= Ekind (Ent)) + or else not Sem_Ch6.Type_Conformant (Ent, Prev) + loop + if Ekind (Prev) = E_Entry then + Set_Intval (Num, Intval (Num) + 1); + + elsif Ekind (Prev) = E_Entry_Family then + S := + Etype (Discrete_Subtype_Definition (Declaration_Node (Prev))); + Lo := Type_Low_Bound (S); + Hi := Type_High_Bound (S); + + Expr := + Make_Op_Add (Sloc, + Left_Opnd => Expr, + Right_Opnd => + Make_Op_Add (Sloc, + Left_Opnd => + Actual_Family_Offset (Hi, Lo), + Right_Opnd => + Make_Integer_Literal (Sloc, 1))); + + -- Other components are anonymous types to be ignored. + + else + null; + end if; + + Next_Entity (Prev); + end loop; + + return Expr; + end Actual_Index_Expression; + + ---------------------------------- + -- Add_Discriminal_Declarations -- + ---------------------------------- + + procedure Add_Discriminal_Declarations + (Decls : List_Id; + Typ : Entity_Id; + Name : Name_Id; + Loc : Source_Ptr) + is + D : Entity_Id; + + begin + if Has_Discriminants (Typ) then + D := First_Discriminant (Typ); + + while Present (D) loop + + Prepend_To (Decls, + Make_Object_Renaming_Declaration (Loc, + Defining_Identifier => Discriminal (D), + Subtype_Mark => New_Reference_To (Etype (D), Loc), + Name => + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name), + Selector_Name => Make_Identifier (Loc, Chars (D))))); + + Next_Discriminant (D); + end loop; + end if; + end Add_Discriminal_Declarations; + + ------------------------ + -- Add_Object_Pointer -- + ------------------------ + + procedure Add_Object_Pointer + (Decls : List_Id; + Pid : Entity_Id; + Loc : Source_Ptr) + is + Obj_Ptr : Node_Id; + + begin + -- Prepend the declaration of _object. This must be first in the + -- declaration list, since it is used by the discriminal and + -- prival declarations. + -- ??? An attempt to make this a renaming was unsuccessful. + -- + -- type poVP is access poV; + -- _object : poVP := poVP!O; + + Obj_Ptr := + Make_Defining_Identifier (Loc, + Chars => + New_External_Name + (Chars (Corresponding_Record_Type (Pid)), 'P')); + + Prepend_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uObject), + Object_Definition => New_Reference_To (Obj_Ptr, Loc), + Expression => + Unchecked_Convert_To (Obj_Ptr, + Make_Identifier (Loc, Name_uO)))); + + Prepend_To (Decls, + Make_Full_Type_Declaration (Loc, + Defining_Identifier => Obj_Ptr, + Type_Definition => Make_Access_To_Object_Definition (Loc, + Subtype_Indication => + New_Reference_To (Corresponding_Record_Type (Pid), Loc)))); + + end Add_Object_Pointer; + + ------------------------------ + -- Add_Private_Declarations -- + ------------------------------ + + procedure Add_Private_Declarations + (Decls : List_Id; + Typ : Entity_Id; + Name : Name_Id; + Loc : Source_Ptr) + is + P : Node_Id; + Pdef : Entity_Id; + Def : Node_Id := Protected_Definition (Parent (Typ)); + Body_Ent : constant Entity_Id := Corresponding_Body (Parent (Typ)); + + begin + pragma Assert (Nkind (Def) = N_Protected_Definition); + + if Present (Private_Declarations (Def)) then + P := First (Private_Declarations (Def)); + + while Present (P) loop + if Nkind (P) = N_Component_Declaration then + Pdef := Defining_Identifier (P); + Prepend_To (Decls, + Make_Object_Renaming_Declaration (Loc, + Defining_Identifier => Prival (Pdef), + Subtype_Mark => New_Reference_To (Etype (Pdef), Loc), + Name => + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name), + Selector_Name => Make_Identifier (Loc, Chars (Pdef))))); + end if; + Next (P); + end loop; + end if; + + -- One more "prival" for the object itself, with the right protection + -- type. + + declare + Protection_Type : RE_Id; + begin + if Has_Attach_Handler (Typ) then + if Restricted_Profile then + Protection_Type := RE_Protection_Entry; + else + Protection_Type := RE_Static_Interrupt_Protection; + end if; + + elsif Has_Interrupt_Handler (Typ) then + Protection_Type := RE_Dynamic_Interrupt_Protection; + + elsif Has_Entries (Typ) then + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Number_Entries (Typ) > 1 + then + Protection_Type := RE_Protection_Entries; + else + Protection_Type := RE_Protection_Entry; + end if; + + else + Protection_Type := RE_Protection; + end if; + + Prepend_To (Decls, + Make_Object_Renaming_Declaration (Loc, + Defining_Identifier => Object_Ref (Body_Ent), + Subtype_Mark => New_Reference_To (RTE (Protection_Type), Loc), + Name => + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name), + Selector_Name => Make_Identifier (Loc, Name_uObject)))); + end; + + end Add_Private_Declarations; + + ---------------- + -- Array_Type -- + ---------------- + + function Array_Type (E : Entity_Id; Trec : Node_Id) return Entity_Id is + Arr : Entity_Id := First_Component (Trec); + + begin + while Present (Arr) loop + exit when Ekind (Arr) = E_Component + and then Is_Array_Type (Etype (Arr)) + and then Chars (Arr) = Chars (E); + + Next_Component (Arr); + end loop; + + -- This used to return Arr itself, but this caused problems + -- when used in expanding a protected type, possibly because + -- the record of which it is a component is not frozen yet. + -- I am going to try the type instead. This may pose visibility + -- problems. ??? + + return Etype (Arr); + end Array_Type; + + ----------------------- + -- Build_Accept_Body -- + ----------------------- + + function Build_Accept_Body (Astat : Node_Id) return Node_Id is + Loc : constant Source_Ptr := Sloc (Astat); + Stats : constant Node_Id := Handled_Statement_Sequence (Astat); + New_S : Node_Id; + Hand : Node_Id; + Call : Node_Id; + Ohandle : Node_Id; + + begin + -- At the end of the statement sequence, Complete_Rendezvous is called. + -- A label skipping the Complete_Rendezvous, and all other + -- accept processing, has already been added for the expansion + -- of requeue statements. + + Call := Build_Runtime_Call (Loc, RE_Complete_Rendezvous); + Insert_Before (Last (Statements (Stats)), Call); + Analyze (Call); + + -- If exception handlers are present, then append Complete_Rendezvous + -- calls to the handlers, and construct the required outer block. + + if Present (Exception_Handlers (Stats)) then + Hand := First (Exception_Handlers (Stats)); + + while Present (Hand) loop + Call := Build_Runtime_Call (Loc, RE_Complete_Rendezvous); + Append (Call, Statements (Hand)); + Analyze (Call); + Next (Hand); + end loop; + + New_S := + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List ( + Make_Block_Statement (Loc, + Handled_Statement_Sequence => Stats))); + + else + New_S := Stats; + end if; + + -- At this stage we know that the new statement sequence does not + -- have an exception handler part, so we supply one to call + -- Exceptional_Complete_Rendezvous. This handler is + + -- when all others => + -- Exceptional_Complete_Rendezvous (Get_GNAT_Exception); + + -- We handle Abort_Signal to make sure that we properly catch the abort + -- case and wake up the caller. + + Ohandle := Make_Others_Choice (Loc); + Set_All_Others (Ohandle); + + Set_Exception_Handlers (New_S, + New_List ( + Make_Exception_Handler (Loc, + Exception_Choices => New_List (Ohandle), + + Statements => New_List ( + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To ( + RTE (RE_Exceptional_Complete_Rendezvous), Loc), + Parameter_Associations => New_List ( + Make_Function_Call (Loc, + Name => New_Reference_To ( + RTE (RE_Get_GNAT_Exception), Loc)))))))); + + Set_Parent (New_S, Astat); -- temp parent for Analyze call + Analyze_Exception_Handlers (Exception_Handlers (New_S)); + Expand_Exception_Handlers (New_S); + + -- Exceptional_Complete_Rendezvous must be called with abort + -- still deferred, which is the case for a "when all others" handler. + + return New_S; + + end Build_Accept_Body; + + ----------------------------------- + -- Build_Activation_Chain_Entity -- + ----------------------------------- + + procedure Build_Activation_Chain_Entity (N : Node_Id) is + P : Node_Id; + B : Node_Id; + Decls : List_Id; + + begin + -- Loop to find enclosing construct containing activation chain variable + + P := Parent (N); + + while Nkind (P) /= N_Subprogram_Body + and then Nkind (P) /= N_Package_Declaration + and then Nkind (P) /= N_Package_Body + and then Nkind (P) /= N_Block_Statement + and then Nkind (P) /= N_Task_Body + loop + P := Parent (P); + end loop; + + -- If we are in a package body, the activation chain variable is + -- allocated in the corresponding spec. First, we save the package + -- body node because we enter the new entity in its Declarations list. + + B := P; + + if Nkind (P) = N_Package_Body then + P := Unit_Declaration_Node (Corresponding_Spec (P)); + Decls := Declarations (B); + + elsif Nkind (P) = N_Package_Declaration then + Decls := Visible_Declarations (Specification (B)); + + else + Decls := Declarations (B); + end if; + + -- If activation chain entity not already declared, declare it + + if No (Activation_Chain_Entity (P)) then + Set_Activation_Chain_Entity + (P, Make_Defining_Identifier (Sloc (N), Name_uChain)); + + Prepend_To (Decls, + Make_Object_Declaration (Sloc (P), + Defining_Identifier => Activation_Chain_Entity (P), + Aliased_Present => True, + Object_Definition => + New_Reference_To (RTE (RE_Activation_Chain), Sloc (P)))); + + Analyze (First (Decls)); + end if; + + end Build_Activation_Chain_Entity; + + ---------------------------- + -- Build_Barrier_Function -- + ---------------------------- + + function Build_Barrier_Function + (N : Node_Id; + Ent : Entity_Id; + Pid : Node_Id) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (N); + Ent_Formals : constant Node_Id := Entry_Body_Formal_Part (N); + Index_Spec : constant Node_Id := Entry_Index_Specification + (Ent_Formals); + Bdef : Entity_Id; + Bspec : Node_Id; + Op_Decls : List_Id := New_List; + + begin + Bdef := + Make_Defining_Identifier (Loc, Chars (Barrier_Function (Ent))); + Bspec := Build_Barrier_Function_Specification (Bdef, Loc); + + -- <object pointer declaration> + -- <discriminant renamings> + -- <private object renamings> + -- Add discriminal and private renamings. These names have + -- already been used to expand references to discriminants + -- and private data. + + Add_Discriminal_Declarations (Op_Decls, Pid, Name_uObject, Loc); + Add_Private_Declarations (Op_Decls, Pid, Name_uObject, Loc); + Add_Object_Pointer (Op_Decls, Pid, Loc); + + -- If this is the barrier for an entry family, the entry index is + -- visible in the body of the barrier. Create a local variable that + -- converts the entry index (which is the last formal of the barrier + -- function) into the appropriate offset into the entry array. The + -- entry index constant must be set, as for the entry body, so that + -- local references to the entry index are correctly replaced with + -- the local variable. This parallels what is done for entry bodies. + + if Present (Index_Spec) then + declare + Index_Id : constant Entity_Id := Defining_Identifier (Index_Spec); + Index_Con : constant Entity_Id := + Make_Defining_Identifier (Loc, New_Internal_Name ('I')); + + begin + Set_Entry_Index_Constant (Index_Id, Index_Con); + Append_List_To (Op_Decls, + Index_Constant_Declaration (N, Index_Id, Pid)); + end; + end if; + + -- Note: the condition in the barrier function needs to be properly + -- processed for the C/Fortran boolean possibility, but this happens + -- automatically since the return statement does this normalization. + + return + Make_Subprogram_Body (Loc, + Specification => Bspec, + Declarations => Op_Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List ( + Make_Return_Statement (Loc, + Expression => Condition (Ent_Formals))))); + end Build_Barrier_Function; + + ------------------------------------------ + -- Build_Barrier_Function_Specification -- + ------------------------------------------ + + function Build_Barrier_Function_Specification + (Def_Id : Entity_Id; + Loc : Source_Ptr) + return Node_Id + is + begin + return Make_Function_Specification (Loc, + Defining_Unit_Name => Def_Id, + Parameter_Specifications => New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, Name_uO), + Parameter_Type => + New_Reference_To (RTE (RE_Address), Loc)), + + Make_Parameter_Specification (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, Name_uE), + Parameter_Type => + New_Reference_To (RTE (RE_Protected_Entry_Index), Loc))), + + Subtype_Mark => New_Reference_To (Standard_Boolean, Loc)); + end Build_Barrier_Function_Specification; + + -------------------------- + -- Build_Call_With_Task -- + -------------------------- + + function Build_Call_With_Task + (N : Node_Id; + E : Entity_Id) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (N); + + begin + return + Make_Function_Call (Loc, + Name => New_Reference_To (E, Loc), + Parameter_Associations => New_List (Concurrent_Ref (N))); + end Build_Call_With_Task; + + -------------------------------- + -- Build_Corresponding_Record -- + -------------------------------- + + function Build_Corresponding_Record + (N : Node_Id; + Ctyp : Entity_Id; + Loc : Source_Ptr) + return Node_Id + is + Rec_Ent : constant Entity_Id := + Make_Defining_Identifier + (Loc, New_External_Name (Chars (Ctyp), 'V')); + Disc : Entity_Id; + Dlist : List_Id; + New_Disc : Entity_Id; + Cdecls : List_Id; + + begin + Set_Corresponding_Record_Type (Ctyp, Rec_Ent); + Set_Ekind (Rec_Ent, E_Record_Type); + Set_Has_Delayed_Freeze (Rec_Ent, Has_Delayed_Freeze (Ctyp)); + Set_Is_Concurrent_Record_Type (Rec_Ent, True); + Set_Corresponding_Concurrent_Type (Rec_Ent, Ctyp); + Set_Girder_Constraint (Rec_Ent, No_Elist); + Cdecls := New_List; + + -- Use discriminals to create list of discriminants for record, and + -- create new discriminals for use in default expressions, etc. It is + -- worth noting that a task discriminant gives rise to 5 entities; + + -- a) The original discriminant. + -- b) The discriminal for use in the task. + -- c) The discriminant of the corresponding record. + -- d) The discriminal for the init_proc of the corresponding record. + -- e) The local variable that renames the discriminant in the procedure + -- for the task body. + + -- In fact the discriminals b) are used in the renaming declarations + -- for e). See details in einfo (Handling of Discriminants). + + if Present (Discriminant_Specifications (N)) then + Dlist := New_List; + Disc := First_Discriminant (Ctyp); + + while Present (Disc) loop + New_Disc := CR_Discriminant (Disc); + + Append_To (Dlist, + Make_Discriminant_Specification (Loc, + Defining_Identifier => New_Disc, + Discriminant_Type => + New_Occurrence_Of (Etype (Disc), Loc), + Expression => + New_Copy (Discriminant_Default_Value (Disc)))); + + Next_Discriminant (Disc); + end loop; + + else + Dlist := No_List; + end if; + + -- Now we can construct the record type declaration. Note that this + -- record is limited, reflecting the underlying limitedness of the + -- task or protected object that it represents, and ensuring for + -- example that it is properly passed by reference. + + return + Make_Full_Type_Declaration (Loc, + Defining_Identifier => Rec_Ent, + Discriminant_Specifications => Dlist, + Type_Definition => + Make_Record_Definition (Loc, + Component_List => + Make_Component_List (Loc, + Component_Items => Cdecls), + Limited_Present => True)); + end Build_Corresponding_Record; + + ---------------------------------- + -- Build_Entry_Count_Expression -- + ---------------------------------- + + function Build_Entry_Count_Expression + (Concurrent_Type : Node_Id; + Component_List : List_Id; + Loc : Source_Ptr) + return Node_Id + is + Eindx : Nat; + Ent : Entity_Id; + Ecount : Node_Id; + Comp : Node_Id; + Lo : Node_Id; + Hi : Node_Id; + Typ : Entity_Id; + + begin + Ent := First_Entity (Concurrent_Type); + Eindx := 0; + + -- Count number of non-family entries + + while Present (Ent) loop + if Ekind (Ent) = E_Entry then + Eindx := Eindx + 1; + end if; + + Next_Entity (Ent); + end loop; + + Ecount := Make_Integer_Literal (Loc, Eindx); + + -- Loop through entry families building the addition nodes + + Ent := First_Entity (Concurrent_Type); + Comp := First (Component_List); + + while Present (Ent) loop + if Ekind (Ent) = E_Entry_Family then + while Chars (Ent) /= Chars (Defining_Identifier (Comp)) loop + Next (Comp); + end loop; + + Typ := Etype (Discrete_Subtype_Definition (Parent (Ent))); + Hi := Type_High_Bound (Typ); + Lo := Type_Low_Bound (Typ); + + Ecount := + Make_Op_Add (Loc, + Left_Opnd => Ecount, + Right_Opnd => Family_Size (Loc, Hi, Lo, Concurrent_Type)); + end if; + + Next_Entity (Ent); + end loop; + + return Ecount; + end Build_Entry_Count_Expression; + + --------------------------- + -- Build_Find_Body_Index -- + --------------------------- + + function Build_Find_Body_Index + (Typ : Entity_Id) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (Typ); + Ent : Entity_Id; + E_Typ : Entity_Id; + Has_F : Boolean := False; + Index : Nat; + If_St : Node_Id := Empty; + Lo : Node_Id; + Hi : Node_Id; + Decls : List_Id := New_List; + Ret : Node_Id; + Spec : Node_Id; + Siz : Node_Id := Empty; + + procedure Add_If_Clause (Expr : Node_Id); + -- Add test for range of current entry. + + function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id; + -- If a bound of an entry is given by a discriminant, retrieve the + -- actual value of the discriminant from the enclosing object. + + ------------------- + -- Add_If_Clause -- + ------------------- + + procedure Add_If_Clause (Expr : Node_Id) is + Cond : Node_Id; + Stats : constant List_Id := + New_List ( + Make_Return_Statement (Loc, + Expression => Make_Integer_Literal (Loc, Index + 1))); + + begin + -- Index for current entry body. + + Index := Index + 1; + + -- Compute total length of entry queues so far. + + if No (Siz) then + Siz := Expr; + else + Siz := + Make_Op_Add (Loc, + Left_Opnd => Siz, + Right_Opnd => Expr); + end if; + + Cond := + Make_Op_Le (Loc, + Left_Opnd => Make_Identifier (Loc, Name_uE), + Right_Opnd => Siz); + + -- Map entry queue indices in the range of the current family + -- into the current index, that designates the entry body. + + if No (If_St) then + If_St := + Make_Implicit_If_Statement (Typ, + Condition => Cond, + Then_Statements => Stats, + Elsif_Parts => New_List); + + Ret := If_St; + + else + Append ( + Make_Elsif_Part (Loc, + Condition => Cond, + Then_Statements => Stats), + Elsif_Parts (If_St)); + end if; + + end Add_If_Clause; + + ------------------------------ + -- Convert_Discriminant_Ref -- + ------------------------------ + + function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id is + B : Node_Id; + + begin + if Is_Entity_Name (Bound) + and then Ekind (Entity (Bound)) = E_Discriminant + then + B := + Make_Selected_Component (Loc, + Prefix => + Unchecked_Convert_To (Corresponding_Record_Type (Typ), + Make_Explicit_Dereference (Loc, + Make_Identifier (Loc, Name_uObject))), + Selector_Name => Make_Identifier (Loc, Chars (Bound))); + Set_Etype (B, Etype (Entity (Bound))); + else + B := New_Copy_Tree (Bound); + end if; + + return B; + end Convert_Discriminant_Ref; + + -- Start of processing for Build_Find_Body_Index + + begin + Spec := Build_Find_Body_Index_Spec (Typ); + + Ent := First_Entity (Typ); + + while Present (Ent) loop + + if Ekind (Ent) = E_Entry_Family then + Has_F := True; + exit; + end if; + + Next_Entity (Ent); + end loop; + + if not Has_F then + + -- If the protected type has no entry families, there is a one-one + -- correspondence between entry queue and entry body. + + Ret := + Make_Return_Statement (Loc, + Expression => Make_Identifier (Loc, Name_uE)); + + else + -- Suppose entries e1, e2, ... have size l1, l2, ... we generate + -- the following: + -- + -- if E <= l1 then return 1; + -- elsif E <= l1 + l2 then return 2; + -- ... + + Index := 0; + Siz := Empty; + Ent := First_Entity (Typ); + + Add_Object_Pointer (Decls, Typ, Loc); + + while Present (Ent) loop + + if Ekind (Ent) = E_Entry then + Add_If_Clause (Make_Integer_Literal (Loc, 1)); + + elsif Ekind (Ent) = E_Entry_Family then + + E_Typ := Etype (Discrete_Subtype_Definition (Parent (Ent))); + Hi := Convert_Discriminant_Ref (Type_High_Bound (E_Typ)); + Lo := Convert_Discriminant_Ref (Type_Low_Bound (E_Typ)); + Add_If_Clause (Family_Size (Loc, Hi, Lo, Typ)); + end if; + + Next_Entity (Ent); + end loop; + + if Index = 1 then + Decls := New_List; + Ret := + Make_Return_Statement (Loc, + Expression => Make_Integer_Literal (Loc, 1)); + + elsif Nkind (Ret) = N_If_Statement then + + -- Ranges are in increasing order, so last one doesn't need a + -- guard. + + declare + Nod : constant Node_Id := Last (Elsif_Parts (Ret)); + + begin + Remove (Nod); + Set_Else_Statements (Ret, Then_Statements (Nod)); + end; + end if; + end if; + + return + Make_Subprogram_Body (Loc, + Specification => Spec, + Declarations => Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List (Ret))); + + end Build_Find_Body_Index; + + -------------------------------- + -- Build_Find_Body_Index_Spec -- + -------------------------------- + + function Build_Find_Body_Index_Spec + (Typ : Entity_Id) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (Typ); + Id : constant Entity_Id := + Make_Defining_Identifier (Loc, + Chars => New_External_Name (Chars (Typ), 'F')); + Parm1 : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uO); + Parm2 : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uE); + + begin + return + Make_Function_Specification (Loc, + Defining_Unit_Name => Id, + Parameter_Specifications => New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => Parm1, + Parameter_Type => + New_Reference_To (RTE (RE_Address), Loc)), + + Make_Parameter_Specification (Loc, + Defining_Identifier => Parm2, + Parameter_Type => + New_Reference_To (RTE (RE_Protected_Entry_Index), Loc))), + Subtype_Mark => New_Occurrence_Of ( + RTE (RE_Protected_Entry_Index), Loc)); + + end Build_Find_Body_Index_Spec; + + ------------------------- + -- Build_Master_Entity -- + ------------------------- + + procedure Build_Master_Entity (E : Entity_Id) is + Loc : constant Source_Ptr := Sloc (E); + P : Node_Id; + Decl : Node_Id; + + begin + -- Nothing to do if we already built a master entity for this scope + -- or if there is no task hierarchy. + + if Has_Master_Entity (Scope (E)) + or else Restrictions (No_Task_Hierarchy) + then + return; + end if; + + -- Otherwise first build the master entity + -- _Master : constant Master_Id := Current_Master.all; + -- and insert it just before the current declaration + + Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uMaster), + Constant_Present => True, + Object_Definition => New_Reference_To (RTE (RE_Master_Id), Loc), + Expression => + Make_Explicit_Dereference (Loc, + New_Reference_To (RTE (RE_Current_Master), Loc))); + + P := Parent (E); + Insert_Before (P, Decl); + Analyze (Decl); + Set_Has_Master_Entity (Scope (E)); + + -- Now mark the containing scope as a task master + + while Nkind (P) /= N_Compilation_Unit loop + P := Parent (P); + + -- If we fall off the top, we are at the outer level, and the + -- environment task is our effective master, so nothing to mark. + + if Nkind (P) = N_Task_Body + or else Nkind (P) = N_Block_Statement + or else Nkind (P) = N_Subprogram_Body + then + Set_Is_Task_Master (P, True); + return; + + elsif Nkind (Parent (P)) = N_Subunit then + P := Corresponding_Stub (Parent (P)); + end if; + end loop; + end Build_Master_Entity; + + --------------------------- + -- Build_Protected_Entry -- + --------------------------- + + function Build_Protected_Entry + (N : Node_Id; + Ent : Entity_Id; + Pid : Node_Id) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (N); + Edef : Entity_Id; + Espec : Node_Id; + Op_Decls : List_Id := New_List; + Op_Stats : List_Id; + Ohandle : Node_Id; + Complete : Node_Id; + + begin + Edef := + Make_Defining_Identifier (Loc, + Chars => Chars (Protected_Body_Subprogram (Ent))); + Espec := Build_Protected_Entry_Specification (Edef, Empty, Loc); + + -- <object pointer declaration> + -- Add object pointer declaration. This is needed by the + -- discriminal and prival renamings, which should already + -- have been inserted into the declaration list. + + Add_Object_Pointer (Op_Decls, Pid, Loc); + + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Number_Entries (Pid) > 1 + then + Complete := New_Reference_To (RTE (RE_Complete_Entry_Body), Loc); + else + Complete := + New_Reference_To (RTE (RE_Complete_Single_Entry_Body), Loc); + end if; + + Op_Stats := New_List ( + Make_Block_Statement (Loc, + Declarations => Declarations (N), + Handled_Statement_Sequence => + Handled_Statement_Sequence (N)), + + Make_Procedure_Call_Statement (Loc, + Name => Complete, + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => + Make_Selected_Component (Loc, + Prefix => + Make_Identifier (Loc, Name_uObject), + + Selector_Name => + Make_Identifier (Loc, Name_uObject)), + Attribute_Name => Name_Unchecked_Access)))); + + if Restrictions (No_Exception_Handlers) then + return + Make_Subprogram_Body (Loc, + Specification => Espec, + Declarations => Op_Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, Op_Stats)); + + else + Ohandle := Make_Others_Choice (Loc); + Set_All_Others (Ohandle); + + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Number_Entries (Pid) > 1 + then + Complete := + New_Reference_To (RTE (RE_Exceptional_Complete_Entry_Body), Loc); + + else + Complete := New_Reference_To ( + RTE (RE_Exceptional_Complete_Single_Entry_Body), Loc); + end if; + + return + Make_Subprogram_Body (Loc, + Specification => Espec, + Declarations => Op_Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => Op_Stats, + Exception_Handlers => New_List ( + Make_Exception_Handler (Loc, + Exception_Choices => New_List (Ohandle), + + Statements => New_List ( + Make_Procedure_Call_Statement (Loc, + Name => Complete, + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => + Make_Selected_Component (Loc, + Prefix => + Make_Identifier (Loc, Name_uObject), + Selector_Name => + Make_Identifier (Loc, Name_uObject)), + Attribute_Name => Name_Unchecked_Access), + + Make_Function_Call (Loc, + Name => New_Reference_To ( + RTE (RE_Get_GNAT_Exception), Loc))))))))); + end if; + end Build_Protected_Entry; + + ----------------------------------------- + -- Build_Protected_Entry_Specification -- + ----------------------------------------- + + function Build_Protected_Entry_Specification + (Def_Id : Entity_Id; + Ent_Id : Entity_Id; + Loc : Source_Ptr) + return Node_Id + is + P : Entity_Id; + + begin + P := Make_Defining_Identifier (Loc, Name_uP); + + if Present (Ent_Id) then + Append_Elmt (P, Accept_Address (Ent_Id)); + end if; + + return Make_Procedure_Specification (Loc, + Defining_Unit_Name => Def_Id, + Parameter_Specifications => New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, Name_uO), + Parameter_Type => + New_Reference_To (RTE (RE_Address), Loc)), + + Make_Parameter_Specification (Loc, + Defining_Identifier => P, + Parameter_Type => + New_Reference_To (RTE (RE_Address), Loc)), + + Make_Parameter_Specification (Loc, + Defining_Identifier => Make_Defining_Identifier (Loc, Name_uE), + Parameter_Type => + New_Reference_To (RTE (RE_Protected_Entry_Index), Loc)))); + end Build_Protected_Entry_Specification; + + -------------------------- + -- Build_Protected_Spec -- + -------------------------- + + function Build_Protected_Spec + (N : Node_Id; + Obj_Type : Entity_Id; + Unprotected : Boolean := False; + Ident : Entity_Id) + return List_Id + is + Loc : constant Source_Ptr := Sloc (N); + Formal : Entity_Id; + New_Plist : List_Id; + New_Param : Node_Id; + + begin + New_Plist := New_List; + Formal := First_Formal (Ident); + + while Present (Formal) loop + New_Param := + Make_Parameter_Specification (Loc, + Defining_Identifier => + Make_Defining_Identifier (Sloc (Formal), Chars (Formal)), + In_Present => In_Present (Parent (Formal)), + Out_Present => Out_Present (Parent (Formal)), + Parameter_Type => + New_Reference_To (Etype (Formal), Loc)); + + if Unprotected then + Set_Protected_Formal (Formal, Defining_Identifier (New_Param)); + end if; + + Append (New_Param, New_Plist); + Next_Formal (Formal); + end loop; + + -- If the subprogram is a procedure and the context is not an access + -- to protected subprogram, the parameter is in-out. Otherwise it is + -- an in parameter. + + Prepend_To (New_Plist, + Make_Parameter_Specification (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uObject), + In_Present => True, + Out_Present => + (Etype (Ident) = Standard_Void_Type + and then not Is_RTE (Obj_Type, RE_Address)), + Parameter_Type => New_Reference_To (Obj_Type, Loc))); + + return New_Plist; + end Build_Protected_Spec; + + --------------------------------------- + -- Build_Protected_Sub_Specification -- + --------------------------------------- + + function Build_Protected_Sub_Specification + (N : Node_Id; + Prottyp : Entity_Id; + Unprotected : Boolean := False) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (N); + Decl : Node_Id; + Protnm : constant Name_Id := Chars (Prottyp); + Ident : Entity_Id; + Nam : Name_Id; + New_Plist : List_Id; + Append_Char : Character; + New_Spec : Node_Id; + + begin + if Ekind + (Defining_Unit_Name (Specification (N))) = E_Subprogram_Body + then + Decl := Unit_Declaration_Node (Corresponding_Spec (N)); + else + Decl := N; + end if; + + Ident := Defining_Unit_Name (Specification (Decl)); + Nam := Chars (Ident); + + New_Plist := Build_Protected_Spec + (Decl, Corresponding_Record_Type (Prottyp), + Unprotected, Ident); + + if Unprotected then + Append_Char := 'N'; + else + Append_Char := 'P'; + end if; + + if Nkind (Specification (Decl)) = N_Procedure_Specification then + return + Make_Procedure_Specification (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, + Chars => Build_Selected_Name (Protnm, Nam, Append_Char)), + Parameter_Specifications => New_Plist); + + else + New_Spec := + Make_Function_Specification (Loc, + Defining_Unit_Name => + Make_Defining_Identifier (Loc, + Chars => Build_Selected_Name (Protnm, Nam, Append_Char)), + Parameter_Specifications => New_Plist, + Subtype_Mark => New_Copy (Subtype_Mark (Specification (Decl)))); + Set_Return_Present (Defining_Unit_Name (New_Spec)); + return New_Spec; + end if; + end Build_Protected_Sub_Specification; + + ------------------------------------- + -- Build_Protected_Subprogram_Body -- + ------------------------------------- + + function Build_Protected_Subprogram_Body + (N : Node_Id; + Pid : Node_Id; + N_Op_Spec : Node_Id) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (N); + Op_Spec : Node_Id; + Op_Def : Entity_Id; + Sub_Name : Name_Id; + P_Op_Spec : Node_Id; + Uactuals : List_Id; + Pformal : Node_Id; + Unprot_Call : Node_Id; + Sub_Body : Node_Id; + Lock_Name : Node_Id; + Lock_Stmt : Node_Id; + Unlock_Name : Node_Id; + Unlock_Stmt : Node_Id; + Service_Name : Node_Id; + Service_Stmt : Node_Id; + R : Node_Id; + Return_Stmt : Node_Id := Empty; + Pre_Stmts : List_Id := No_List; + -- Initializations to avoid spurious warnings from GCC3. + Stmts : List_Id; + Object_Parm : Node_Id; + Exc_Safe : Boolean; + + function Is_Exception_Safe (Subprogram : Node_Id) return Boolean; + -- Tell whether a given subprogram cannot raise an exception + + ----------------------- + -- Is_Exception_Safe -- + ----------------------- + + function Is_Exception_Safe (Subprogram : Node_Id) return Boolean is + + function Has_Side_Effect (N : Node_Id) return Boolean; + -- Return True whenever encountering a subprogram call or a + -- raise statement of any kind in the sequence of statements N + + --------------------- + -- Has_Side_Effect -- + --------------------- + + -- What is this doing buried two levels down in exp_ch9. It + -- seems like a generally useful function, and indeed there + -- may be code duplication going on here ??? + + function Has_Side_Effect (N : Node_Id) return Boolean is + Stmt : Node_Id := N; + Expr : Node_Id; + + function Is_Call_Or_Raise (N : Node_Id) return Boolean; + -- Indicate whether N is a subprogram call or a raise statement + + function Is_Call_Or_Raise (N : Node_Id) return Boolean is + begin + return Nkind (N) = N_Procedure_Call_Statement + or else Nkind (N) = N_Function_Call + or else Nkind (N) = N_Raise_Statement + or else Nkind (N) = N_Raise_Constraint_Error + or else Nkind (N) = N_Raise_Program_Error + or else Nkind (N) = N_Raise_Storage_Error; + end Is_Call_Or_Raise; + + -- Start of processing for Has_Side_Effect + + begin + while Present (Stmt) loop + if Is_Call_Or_Raise (Stmt) then + return True; + end if; + + -- An object declaration can also contain a function call + -- or a raise statement + + if Nkind (Stmt) = N_Object_Declaration then + Expr := Expression (Stmt); + + if Present (Expr) and then Is_Call_Or_Raise (Expr) then + return True; + end if; + end if; + + Next (Stmt); + end loop; + + return False; + end Has_Side_Effect; + + -- Start of processing for Is_Exception_Safe + + begin + -- If the checks handled by the back end are not disabled, we cannot + -- ensure that no exception will be raised. + + if not Access_Checks_Suppressed (Empty) + or else not Discriminant_Checks_Suppressed (Empty) + or else not Range_Checks_Suppressed (Empty) + or else not Index_Checks_Suppressed (Empty) + or else Opt.Stack_Checking_Enabled + then + return False; + end if; + + if Has_Side_Effect (First (Declarations (Subprogram))) + or else + Has_Side_Effect ( + First (Statements (Handled_Statement_Sequence (Subprogram)))) + then + return False; + else + return True; + end if; + end Is_Exception_Safe; + + -- Start of processing for Build_Protected_Subprogram_Body + + begin + Op_Spec := Specification (N); + Op_Def := Defining_Unit_Name (Op_Spec); + Exc_Safe := Is_Exception_Safe (N); + + Sub_Name := Chars (Defining_Unit_Name (Specification (N))); + + P_Op_Spec := + Build_Protected_Sub_Specification (N, + Pid, Unprotected => False); + + -- Build a list of the formal parameters of the protected + -- version of the subprogram to use as the actual parameters + -- of the unprotected version. + + Uactuals := New_List; + Pformal := First (Parameter_Specifications (P_Op_Spec)); + + while Present (Pformal) loop + Append ( + Make_Identifier (Loc, Chars (Defining_Identifier (Pformal))), + Uactuals); + Next (Pformal); + end loop; + + -- Make a call to the unprotected version of the subprogram + -- built above for use by the protected version built below. + + if Nkind (Op_Spec) = N_Function_Specification then + if Exc_Safe then + R := Make_Defining_Identifier (Loc, New_Internal_Name ('R')); + Unprot_Call := + Make_Object_Declaration (Loc, + Defining_Identifier => R, + Constant_Present => True, + Object_Definition => New_Copy (Subtype_Mark (N_Op_Spec)), + Expression => + Make_Function_Call (Loc, + Name => Make_Identifier (Loc, + Chars (Defining_Unit_Name (N_Op_Spec))), + Parameter_Associations => Uactuals)); + Return_Stmt := Make_Return_Statement (Loc, + Expression => New_Reference_To (R, Loc)); + + else + Unprot_Call := Make_Return_Statement (Loc, + Expression => Make_Function_Call (Loc, + Name => + Make_Identifier (Loc, + Chars (Defining_Unit_Name (N_Op_Spec))), + Parameter_Associations => Uactuals)); + end if; + + else + Unprot_Call := Make_Procedure_Call_Statement (Loc, + Name => + Make_Identifier (Loc, + Chars (Defining_Unit_Name (N_Op_Spec))), + Parameter_Associations => Uactuals); + end if; + + -- Wrap call in block that will be covered by an at_end handler. + + if not Exc_Safe then + Unprot_Call := Make_Block_Statement (Loc, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List (Unprot_Call))); + end if; + + -- Make the protected subprogram body. This locks the protected + -- object and calls the unprotected version of the subprogram. + + -- If the protected object is controlled (i.e it has entries or + -- needs finalization for interrupt handling), call Lock_Entries, + -- except if the protected object follows the Ravenscar profile, in + -- which case call Lock_Entry, otherwise call the simplified version, + -- Lock. + + if Has_Entries (Pid) + or else Has_Interrupt_Handler (Pid) + or else Has_Attach_Handler (Pid) + then + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Number_Entries (Pid) > 1 + then + Lock_Name := New_Reference_To (RTE (RE_Lock_Entries), Loc); + Unlock_Name := New_Reference_To (RTE (RE_Unlock_Entries), Loc); + Service_Name := New_Reference_To (RTE (RE_Service_Entries), Loc); + + else + Lock_Name := New_Reference_To (RTE (RE_Lock_Entry), Loc); + Unlock_Name := New_Reference_To (RTE (RE_Unlock_Entry), Loc); + Service_Name := New_Reference_To (RTE (RE_Service_Entry), Loc); + end if; + + else + Lock_Name := New_Reference_To (RTE (RE_Lock), Loc); + Unlock_Name := New_Reference_To (RTE (RE_Unlock), Loc); + Service_Name := Empty; + end if; + + Object_Parm := + Make_Attribute_Reference (Loc, + Prefix => + Make_Selected_Component (Loc, + Prefix => + Make_Identifier (Loc, Name_uObject), + Selector_Name => + Make_Identifier (Loc, Name_uObject)), + Attribute_Name => Name_Unchecked_Access); + + Lock_Stmt := Make_Procedure_Call_Statement (Loc, + Name => Lock_Name, + Parameter_Associations => New_List (Object_Parm)); + + if Abort_Allowed then + Stmts := New_List ( + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Abort_Defer), Loc), + Parameter_Associations => Empty_List), + Lock_Stmt); + + else + Stmts := New_List (Lock_Stmt); + end if; + + if not Exc_Safe then + Append (Unprot_Call, Stmts); + else + if Nkind (Op_Spec) = N_Function_Specification then + Pre_Stmts := Stmts; + Stmts := Empty_List; + else + Append (Unprot_Call, Stmts); + end if; + + if Service_Name /= Empty then + Service_Stmt := Make_Procedure_Call_Statement (Loc, + Name => Service_Name, + Parameter_Associations => + New_List (New_Copy_Tree (Object_Parm))); + Append (Service_Stmt, Stmts); + end if; + + Unlock_Stmt := + Make_Procedure_Call_Statement (Loc, + Name => Unlock_Name, + Parameter_Associations => New_List ( + New_Copy_Tree (Object_Parm))); + Append (Unlock_Stmt, Stmts); + + if Abort_Allowed then + Append ( + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc), + Parameter_Associations => Empty_List), + Stmts); + end if; + + if Nkind (Op_Spec) = N_Function_Specification then + Append (Return_Stmt, Stmts); + Append (Make_Block_Statement (Loc, + Declarations => New_List (Unprot_Call), + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => Stmts)), Pre_Stmts); + Stmts := Pre_Stmts; + end if; + end if; + + Sub_Body := + Make_Subprogram_Body (Loc, + Declarations => Empty_List, + Specification => P_Op_Spec, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, Statements => Stmts)); + + if not Exc_Safe then + Set_Is_Protected_Subprogram_Body (Sub_Body); + end if; + + return Sub_Body; + end Build_Protected_Subprogram_Body; + + ------------------------------------- + -- Build_Protected_Subprogram_Call -- + ------------------------------------- + + procedure Build_Protected_Subprogram_Call + (N : Node_Id; + Name : Node_Id; + Rec : Node_Id; + External : Boolean := True) + is + Loc : constant Source_Ptr := Sloc (N); + Sub : Entity_Id := Entity (Name); + New_Sub : Node_Id; + Params : List_Id; + + begin + if External then + New_Sub := New_Occurrence_Of (External_Subprogram (Sub), Loc); + else + New_Sub := + New_Occurrence_Of (Protected_Body_Subprogram (Sub), Loc); + end if; + + if Present (Parameter_Associations (N)) then + Params := New_Copy_List_Tree (Parameter_Associations (N)); + else + Params := New_List; + end if; + + Prepend (Rec, Params); + + if Ekind (Sub) = E_Procedure then + Rewrite (N, + Make_Procedure_Call_Statement (Loc, + Name => New_Sub, + Parameter_Associations => Params)); + + else + pragma Assert (Ekind (Sub) = E_Function); + Rewrite (N, + Make_Function_Call (Loc, + Name => New_Sub, + Parameter_Associations => Params)); + end if; + + if External + and then Nkind (Rec) = N_Unchecked_Type_Conversion + and then Is_Entity_Name (Expression (Rec)) + and then Is_Shared_Passive (Entity (Expression (Rec))) + then + Add_Shared_Var_Lock_Procs (N); + end if; + + end Build_Protected_Subprogram_Call; + + ------------------------- + -- Build_Selected_Name -- + ------------------------- + + function Build_Selected_Name + (Prefix, Selector : Name_Id; + Append_Char : Character := ' ') + return Name_Id + is + Select_Buffer : String (1 .. Hostparm.Max_Name_Length); + Select_Len : Natural; + + begin + Get_Name_String (Selector); + Select_Len := Name_Len; + Select_Buffer (1 .. Select_Len) := Name_Buffer (1 .. Name_Len); + Get_Name_String (Prefix); + + -- If scope is anonymous type, discard suffix to recover name of + -- single protected object. Otherwise use protected type name. + + if Name_Buffer (Name_Len) = 'T' then + Name_Len := Name_Len - 1; + end if; + + Name_Buffer (Name_Len + 1) := 'P'; + Name_Buffer (Name_Len + 2) := 'T'; + Name_Buffer (Name_Len + 3) := '_'; + Name_Buffer (Name_Len + 4) := '_'; + + Name_Len := Name_Len + 4; + for J in 1 .. Select_Len loop + Name_Len := Name_Len + 1; + Name_Buffer (Name_Len) := Select_Buffer (J); + end loop; + + if Append_Char /= ' ' then + Name_Len := Name_Len + 1; + Name_Buffer (Name_Len) := Append_Char; + end if; + + return Name_Find; + end Build_Selected_Name; + + ----------------------------- + -- Build_Simple_Entry_Call -- + ----------------------------- + + -- A task entry call is converted to a call to Call_Simple + + -- declare + -- P : parms := (parm, parm, parm); + -- begin + -- Call_Simple (acceptor-task, entry-index, P'Address); + -- parm := P.param; + -- parm := P.param; + -- ... + -- end; + + -- Here Pnn is an aggregate of the type constructed for the entry to hold + -- the parameters, and the constructed aggregate value contains either the + -- parameters or, in the case of non-elementary types, references to these + -- parameters. Then the address of this aggregate is passed to the runtime + -- routine, along with the task id value and the task entry index value. + -- Pnn is only required if parameters are present. + + -- The assignments after the call are present only in the case of in-out + -- or out parameters for elementary types, and are used to assign back the + -- resulting values of such parameters. + + -- Note: the reason that we insert a block here is that in the context + -- of selects, conditional entry calls etc. the entry call statement + -- appears on its own, not as an element of a list. + + -- A protected entry call is converted to a Protected_Entry_Call: + + -- declare + -- P : E1_Params := (param, param, param); + -- Pnn : Boolean; + -- Bnn : Communications_Block; + + -- declare + -- P : E1_Params := (param, param, param); + -- Bnn : Communications_Block; + + -- begin + -- Protected_Entry_Call ( + -- Object => po._object'Access, + -- E => <entry index>; + -- Uninterpreted_Data => P'Address; + -- Mode => Simple_Call; + -- Block => Bnn); + -- parm := P.param; + -- parm := P.param; + -- ... + -- end; + + procedure Build_Simple_Entry_Call + (N : Node_Id; + Concval : Node_Id; + Ename : Node_Id; + Index : Node_Id) + is + begin + Expand_Call (N); + + -- Convert entry call to Call_Simple call + + declare + Loc : constant Source_Ptr := Sloc (N); + Parms : constant List_Id := Parameter_Associations (N); + Pdecl : Node_Id; + Xdecl : Node_Id; + Decls : List_Id; + Conctyp : Node_Id; + Ent : Entity_Id; + Ent_Acc : Entity_Id; + P : Entity_Id; + X : Entity_Id; + Plist : List_Id; + Parm1 : Node_Id; + Parm2 : Node_Id; + Parm3 : Node_Id; + Call : Node_Id; + Actual : Node_Id; + Formal : Node_Id; + N_Node : Node_Id; + N_Var : Node_Id; + Stats : List_Id := New_List; + Comm_Name : Entity_Id; + + begin + -- Simple entry and entry family cases merge here + + Ent := Entity (Ename); + Ent_Acc := Entry_Parameters_Type (Ent); + Conctyp := Etype (Concval); + + -- If prefix is an access type, dereference to obtain the task type + + if Is_Access_Type (Conctyp) then + Conctyp := Designated_Type (Conctyp); + end if; + + -- Special case for protected subprogram calls. + + if Is_Protected_Type (Conctyp) + and then Is_Subprogram (Entity (Ename)) + then + Build_Protected_Subprogram_Call + (N, Ename, Convert_Concurrent (Concval, Conctyp)); + Analyze (N); + return; + end if; + + -- First parameter is the Task_Id value from the task value or the + -- Object from the protected object value, obtained by selecting + -- the _Task_Id or _Object from the result of doing an unchecked + -- conversion to convert the value to the corresponding record type. + + Parm1 := Concurrent_Ref (Concval); + + -- Second parameter is the entry index, computed by the routine + -- provided for this purpose. The value of this expression is + -- assigned to an intermediate variable to assure that any entry + -- family index expressions are evaluated before the entry + -- parameters. + + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else not Is_Protected_Type (Conctyp) + or else Number_Entries (Conctyp) > 1 + then + X := Make_Defining_Identifier (Loc, Name_uX); + + Xdecl := + Make_Object_Declaration (Loc, + Defining_Identifier => X, + Object_Definition => + New_Reference_To (RTE (RE_Task_Entry_Index), Loc), + Expression => Actual_Index_Expression ( + Loc, Entity (Ename), Index, Concval)); + + Decls := New_List (Xdecl); + Parm2 := New_Reference_To (X, Loc); + + else + Xdecl := Empty; + Decls := New_List; + Parm2 := Empty; + end if; + + -- The third parameter is the packaged parameters. If there are + -- none, then it is just the null address, since nothing is passed + + if No (Parms) then + Parm3 := New_Reference_To (RTE (RE_Null_Address), Loc); + P := Empty; + + -- Case of parameters present, where third argument is the address + -- of a packaged record containing the required parameter values. + + else + -- First build a list of parameter values, which are + -- references to objects of the parameter types. + + Plist := New_List; + + Actual := First_Actual (N); + Formal := First_Formal (Ent); + + while Present (Actual) loop + + -- If it is a by_copy_type, copy it to a new variable. The + -- packaged record has a field that points to this variable. + + if Is_By_Copy_Type (Etype (Actual)) then + N_Node := + Make_Object_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('I')), + Aliased_Present => True, + Object_Definition => + New_Reference_To (Etype (Formal), Loc)); + + -- We have to make an assignment statement separate for + -- the case of limited type. We can not assign it unless + -- the Assignment_OK flag is set first. + + if Ekind (Formal) /= E_Out_Parameter then + N_Var := + New_Reference_To (Defining_Identifier (N_Node), Loc); + Set_Assignment_OK (N_Var); + Append_To (Stats, + Make_Assignment_Statement (Loc, + Name => N_Var, + Expression => Relocate_Node (Actual))); + end if; + + Append (N_Node, Decls); + + Append_To (Plist, + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Unchecked_Access, + Prefix => + New_Reference_To (Defining_Identifier (N_Node), Loc))); + else + Append_To (Plist, + Make_Reference (Loc, Prefix => Relocate_Node (Actual))); + end if; + + Next_Actual (Actual); + Next_Formal_With_Extras (Formal); + end loop; + + -- Now build the declaration of parameters initialized with the + -- aggregate containing this constructed parameter list. + + P := Make_Defining_Identifier (Loc, Name_uP); + + Pdecl := + Make_Object_Declaration (Loc, + Defining_Identifier => P, + Object_Definition => + New_Reference_To (Designated_Type (Ent_Acc), Loc), + Expression => + Make_Aggregate (Loc, Expressions => Plist)); + + Parm3 := + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Address, + Prefix => New_Reference_To (P, Loc)); + + Append (Pdecl, Decls); + end if; + + -- Now we can create the call, case of protected type + + if Is_Protected_Type (Conctyp) then + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Number_Entries (Conctyp) > 1 + then + -- Change the type of the index declaration + + Set_Object_Definition (Xdecl, + New_Reference_To (RTE (RE_Protected_Entry_Index), Loc)); + + -- Some additional declarations for protected entry calls + + if No (Decls) then + Decls := New_List; + end if; + + -- Bnn : Communications_Block; + + Comm_Name := + Make_Defining_Identifier (Loc, New_Internal_Name ('B')); + + Append_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => Comm_Name, + Object_Definition => + New_Reference_To (RTE (RE_Communication_Block), Loc))); + + -- Some additional statements for protected entry calls + + -- Protected_Entry_Call ( + -- Object => po._object'Access, + -- E => <entry index>; + -- Uninterpreted_Data => P'Address; + -- Mode => Simple_Call; + -- Block => Bnn); + + Call := + Make_Procedure_Call_Statement (Loc, + Name => + New_Reference_To (RTE (RE_Protected_Entry_Call), Loc), + + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Unchecked_Access, + Prefix => Parm1), + Parm2, + Parm3, + New_Reference_To (RTE (RE_Simple_Call), Loc), + New_Occurrence_Of (Comm_Name, Loc))); + + else + -- Protected_Single_Entry_Call ( + -- Object => po._object'Access, + -- Uninterpreted_Data => P'Address; + -- Mode => Simple_Call); + + Call := + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To ( + RTE (RE_Protected_Single_Entry_Call), Loc), + + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Unchecked_Access, + Prefix => Parm1), + Parm3, + New_Reference_To (RTE (RE_Simple_Call), Loc))); + end if; + + -- Case of task type + + else + Call := + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Call_Simple), Loc), + Parameter_Associations => New_List (Parm1, Parm2, Parm3)); + + end if; + + Append_To (Stats, Call); + + -- If there are out or in/out parameters by copy + -- add assignment statements for the result values. + + if Present (Parms) then + Actual := First_Actual (N); + Formal := First_Formal (Ent); + + Set_Assignment_OK (Actual); + while Present (Actual) loop + if Is_By_Copy_Type (Etype (Actual)) + and then Ekind (Formal) /= E_In_Parameter + then + N_Node := + Make_Assignment_Statement (Loc, + Name => New_Copy (Actual), + Expression => + Make_Explicit_Dereference (Loc, + Make_Selected_Component (Loc, + Prefix => New_Reference_To (P, Loc), + Selector_Name => + Make_Identifier (Loc, Chars (Formal))))); + + -- In all cases (including limited private types) we + -- want the assignment to be valid. + + Set_Assignment_OK (Name (N_Node)); + + -- If the call is the triggering alternative in an + -- asynchronous select, or the entry_call alternative + -- of a conditional entry call, the assignments for in-out + -- parameters are incorporated into the statement list + -- that follows, so that there are executed only if the + -- entry call succeeds. + + if (Nkind (Parent (N)) = N_Triggering_Alternative + and then N = Triggering_Statement (Parent (N))) + or else + (Nkind (Parent (N)) = N_Entry_Call_Alternative + and then N = Entry_Call_Statement (Parent (N))) + then + if No (Statements (Parent (N))) then + Set_Statements (Parent (N), New_List); + end if; + + Prepend (N_Node, Statements (Parent (N))); + + else + Insert_After (Call, N_Node); + end if; + end if; + + Next_Actual (Actual); + Next_Formal_With_Extras (Formal); + end loop; + end if; + + -- Finally, create block and analyze it + + Rewrite (N, + Make_Block_Statement (Loc, + Declarations => Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => Stats))); + + Analyze (N); + end; + + end Build_Simple_Entry_Call; + + -------------------------------- + -- Build_Task_Activation_Call -- + -------------------------------- + + procedure Build_Task_Activation_Call (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Chain : Entity_Id; + Call : Node_Id; + Name : Node_Id; + P : Node_Id; + + begin + -- Get the activation chain entity. Except in the case of a package + -- body, this is in the node that was passed. For a package body, we + -- have to find the corresponding package declaration node. + + if Nkind (N) = N_Package_Body then + P := Corresponding_Spec (N); + + loop + P := Parent (P); + exit when Nkind (P) = N_Package_Declaration; + end loop; + + Chain := Activation_Chain_Entity (P); + + else + Chain := Activation_Chain_Entity (N); + end if; + + if Present (Chain) then + if Restricted_Profile then + Name := New_Reference_To (RTE (RE_Activate_Restricted_Tasks), Loc); + else + Name := New_Reference_To (RTE (RE_Activate_Tasks), Loc); + end if; + + Call := + Make_Procedure_Call_Statement (Loc, + Name => Name, + Parameter_Associations => + New_List (Make_Attribute_Reference (Loc, + Prefix => New_Occurrence_Of (Chain, Loc), + Attribute_Name => Name_Unchecked_Access))); + + if Nkind (N) = N_Package_Declaration then + if Present (Corresponding_Body (N)) then + null; + + elsif Present (Private_Declarations (Specification (N))) then + Append (Call, Private_Declarations (Specification (N))); + + else + Append (Call, Visible_Declarations (Specification (N))); + end if; + + else + if Present (Handled_Statement_Sequence (N)) then + + -- The call goes at the start of the statement sequence, but + -- after the start of exception range label if one is present. + + declare + Stm : Node_Id; + + begin + Stm := First (Statements (Handled_Statement_Sequence (N))); + + if Nkind (Stm) = N_Label and then Exception_Junk (Stm) then + Next (Stm); + end if; + + Insert_Before (Stm, Call); + end; + + else + Set_Handled_Statement_Sequence (N, + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List (Call))); + end if; + end if; + + Analyze (Call); + Check_Task_Activation (N); + end if; + + end Build_Task_Activation_Call; + + ------------------------------- + -- Build_Task_Allocate_Block -- + ------------------------------- + + procedure Build_Task_Allocate_Block + (Actions : List_Id; + N : Node_Id; + Args : List_Id) + is + T : constant Entity_Id := Entity (Expression (N)); + Init : constant Entity_Id := Base_Init_Proc (T); + Loc : constant Source_Ptr := Sloc (N); + + Chain : Entity_Id := Make_Defining_Identifier (Loc, Name_uChain); + Blkent : Entity_Id; + Block : Node_Id; + + begin + Blkent := Make_Defining_Identifier (Loc, New_Internal_Name ('A')); + + Block := + Make_Block_Statement (Loc, + Identifier => New_Reference_To (Blkent, Loc), + Declarations => New_List ( + + -- _Chain : Activation_Chain; + + Make_Object_Declaration (Loc, + Defining_Identifier => Chain, + Aliased_Present => True, + Object_Definition => + New_Reference_To (RTE (RE_Activation_Chain), Loc))), + + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + + Statements => New_List ( + + -- Init (Args); + + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (Init, Loc), + Parameter_Associations => Args), + + -- Activate_Tasks (_Chain); + + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Activate_Tasks), Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Chain, Loc), + Attribute_Name => Name_Unchecked_Access))))), + + Has_Created_Identifier => True, + Is_Task_Allocation_Block => True); + + Append_To (Actions, + Make_Implicit_Label_Declaration (Loc, + Defining_Identifier => Blkent, + Label_Construct => Block)); + + Append_To (Actions, Block); + + Set_Activation_Chain_Entity (Block, Chain); + + end Build_Task_Allocate_Block; + + ----------------------------------- + -- Build_Task_Proc_Specification -- + ----------------------------------- + + function Build_Task_Proc_Specification (T : Entity_Id) return Node_Id is + Loc : constant Source_Ptr := Sloc (T); + Nam : constant Name_Id := Chars (T); + Tdec : constant Node_Id := Declaration_Node (T); + Ent : Entity_Id; + + begin + Ent := + Make_Defining_Identifier (Loc, + Chars => New_External_Name (Nam, 'B')); + Set_Is_Internal (Ent); + + -- Associate the procedure with the task, if this is the declaration + -- (and not the body) of the procedure. + + if No (Task_Body_Procedure (Tdec)) then + Set_Task_Body_Procedure (Tdec, Ent); + end if; + + return + Make_Procedure_Specification (Loc, + Defining_Unit_Name => Ent, + Parameter_Specifications => + New_List ( + Make_Parameter_Specification (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uTask), + Parameter_Type => + Make_Access_Definition (Loc, + Subtype_Mark => + New_Reference_To + (Corresponding_Record_Type (T), Loc))))); + + end Build_Task_Proc_Specification; + + --------------------------------------- + -- Build_Unprotected_Subprogram_Body -- + --------------------------------------- + + function Build_Unprotected_Subprogram_Body + (N : Node_Id; + Pid : Node_Id) + return Node_Id + is + Loc : constant Source_Ptr := Sloc (N); + Sub_Name : Name_Id; + N_Op_Spec : Node_Id; + Op_Decls : List_Id; + + begin + -- Make an unprotected version of the subprogram for use + -- within the same object, with a new name and an additional + -- parameter representing the object. + + Op_Decls := Declarations (N); + Sub_Name := Chars (Defining_Unit_Name (Specification (N))); + + N_Op_Spec := + Build_Protected_Sub_Specification + (N, Pid, Unprotected => True); + + return + Make_Subprogram_Body (Loc, + Specification => N_Op_Spec, + Declarations => Op_Decls, + Handled_Statement_Sequence => + Handled_Statement_Sequence (N)); + + end Build_Unprotected_Subprogram_Body; + + ---------------------------- + -- Collect_Entry_Families -- + ---------------------------- + + procedure Collect_Entry_Families + (Loc : Source_Ptr; + Cdecls : List_Id; + Current_Node : in out Node_Id; + Conctyp : Entity_Id) + is + Efam : Entity_Id; + Efam_Decl : Node_Id; + Efam_Type : Entity_Id; + + begin + Efam := First_Entity (Conctyp); + + while Present (Efam) loop + + if Ekind (Efam) = E_Entry_Family then + Efam_Type := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('F')); + + Efam_Decl := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => Efam_Type, + Type_Definition => + Make_Unconstrained_Array_Definition (Loc, + Subtype_Marks => (New_List ( + New_Occurrence_Of ( + Base_Type + (Etype (Discrete_Subtype_Definition + (Parent (Efam)))), Loc))), + + Subtype_Indication => + New_Reference_To (Standard_Character, Loc))); + + Insert_After (Current_Node, Efam_Decl); + Current_Node := Efam_Decl; + Analyze (Efam_Decl); + + Append_To (Cdecls, + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Chars (Efam)), + + Subtype_Indication => + Make_Subtype_Indication (Loc, + Subtype_Mark => + New_Occurrence_Of (Efam_Type, Loc), + + Constraint => + Make_Index_Or_Discriminant_Constraint (Loc, + Constraints => New_List ( + New_Occurrence_Of + (Etype (Discrete_Subtype_Definition + (Parent (Efam))), Loc)))))); + end if; + + Next_Entity (Efam); + end loop; + end Collect_Entry_Families; + + -------------------- + -- Concurrent_Ref -- + -------------------- + + -- The expression returned for a reference to a concurrent + -- object has the form: + + -- taskV!(name)._Task_Id + + -- for a task, and + + -- objectV!(name)._Object + + -- for a protected object. + + -- For the case of an access to a concurrent object, + -- there is an extra explicit dereference: + + -- taskV!(name.all)._Task_Id + -- objectV!(name.all)._Object + + -- here taskV and objectV are the types for the associated records, which + -- contain the required _Task_Id and _Object fields for tasks and + -- protected objects, respectively. + + -- For the case of a task type name, the expression is + + -- Self; + + -- i.e. a call to the Self function which returns precisely this Task_Id + + -- For the case of a protected type name, the expression is + + -- objectR + + -- which is a renaming of the _object field of the current object + -- object record, passed into protected operations as a parameter. + + function Concurrent_Ref (N : Node_Id) return Node_Id is + Loc : constant Source_Ptr := Sloc (N); + Ntyp : constant Entity_Id := Etype (N); + Dtyp : Entity_Id; + Sel : Name_Id; + + function Is_Current_Task (T : Entity_Id) return Boolean; + -- Check whether the reference is to the immediately enclosing task + -- type, or to an outer one (rare but legal). + + --------------------- + -- Is_Current_Task -- + --------------------- + + function Is_Current_Task (T : Entity_Id) return Boolean is + Scop : Entity_Id; + + begin + Scop := Current_Scope; + while Present (Scop) + and then Scop /= Standard_Standard + loop + + if Scop = T then + return True; + + elsif Is_Task_Type (Scop) then + return False; + + -- If this is a procedure nested within the task type, we must + -- assume that it can be called from an inner task, and therefore + -- cannot treat it as a local reference. + + elsif Is_Overloadable (Scop) + and then In_Open_Scopes (T) + then + return False; + + else + Scop := Scope (Scop); + end if; + end loop; + + -- We know that we are within the task body, so should have + -- found it in scope. + + raise Program_Error; + end Is_Current_Task; + + -- Start of processing for Concurrent_Ref + + begin + if Is_Access_Type (Ntyp) then + Dtyp := Designated_Type (Ntyp); + + if Is_Protected_Type (Dtyp) then + Sel := Name_uObject; + else + Sel := Name_uTask_Id; + end if; + + return + Make_Selected_Component (Loc, + Prefix => + Unchecked_Convert_To (Corresponding_Record_Type (Dtyp), + Make_Explicit_Dereference (Loc, N)), + Selector_Name => Make_Identifier (Loc, Sel)); + + elsif Is_Entity_Name (N) + and then Is_Concurrent_Type (Entity (N)) + then + if Is_Task_Type (Entity (N)) then + + if Is_Current_Task (Entity (N)) then + return + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_Self), Loc)); + + else + declare + Decl : Node_Id; + T_Self : constant Entity_Id + := Make_Defining_Identifier (Loc, New_Internal_Name ('T')); + T_Body : constant Node_Id + := Parent (Corresponding_Body (Parent (Entity (N)))); + + begin + Decl := Make_Object_Declaration (Loc, + Defining_Identifier => T_Self, + Object_Definition => + New_Occurrence_Of (RTE (RO_ST_Task_ID), Loc), + Expression => + Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_Self), Loc))); + Prepend (Decl, Declarations (T_Body)); + Analyze (Decl); + Set_Scope (T_Self, Entity (N)); + return New_Occurrence_Of (T_Self, Loc); + end; + end if; + + else + pragma Assert (Is_Protected_Type (Entity (N))); + return + New_Reference_To ( + Object_Ref (Corresponding_Body (Parent (Base_Type (Ntyp)))), + Loc); + end if; + + else + pragma Assert (Is_Concurrent_Type (Ntyp)); + + if Is_Protected_Type (Ntyp) then + Sel := Name_uObject; + else + Sel := Name_uTask_Id; + end if; + + return + Make_Selected_Component (Loc, + Prefix => + Unchecked_Convert_To (Corresponding_Record_Type (Ntyp), + New_Copy_Tree (N)), + Selector_Name => Make_Identifier (Loc, Sel)); + end if; + end Concurrent_Ref; + + ------------------------ + -- Convert_Concurrent -- + ------------------------ + + function Convert_Concurrent + (N : Node_Id; + Typ : Entity_Id) + return Node_Id + is + begin + if not Is_Concurrent_Type (Typ) then + return N; + else + return + Unchecked_Convert_To (Corresponding_Record_Type (Typ), + New_Copy_Tree (N)); + end if; + end Convert_Concurrent; + + ---------------------------- + -- Entry_Index_Expression -- + ---------------------------- + + function Entry_Index_Expression + (Sloc : Source_Ptr; + Ent : Entity_Id; + Index : Node_Id; + Ttyp : Entity_Id) + return Node_Id + is + Expr : Node_Id; + Num : Node_Id; + Lo : Node_Id; + Hi : Node_Id; + Prev : Entity_Id; + S : Node_Id; + + begin + -- The queues of entries and entry families appear in textual + -- order in the associated record. The entry index is computed as + -- the sum of the number of queues for all entries that precede the + -- designated one, to which is added the index expression, if this + -- expression denotes a member of a family. + + -- The following is a place holder for the count of simple entries. + + Num := Make_Integer_Literal (Sloc, 1); + + -- We construct an expression which is a series of addition + -- operations. The first operand is the number of single entries that + -- precede this one, the second operand is the index value relative + -- to the start of the referenced family, and the remaining operands + -- are the lengths of the entry families that precede this entry, i.e. + -- the constructed expression is: + + -- number_simple_entries + + -- (s'pos (index-value) - s'pos (family'first)) + 1 + + -- family'length + ... + + -- where index-value is the given index value, and s is the index + -- subtype (we have to use pos because the subtype might be an + -- enumeration type preventing direct subtraction). + -- Note that the task entry array is one-indexed. + + -- The upper bound of the entry family may be a discriminant, so we + -- retrieve the lower bound explicitly to compute offset, rather than + -- using the index subtype which may mention a discriminant. + + if Present (Index) then + S := Etype (Discrete_Subtype_Definition (Declaration_Node (Ent))); + + Expr := + Make_Op_Add (Sloc, + Left_Opnd => Num, + + Right_Opnd => + Family_Offset ( + Sloc, + Make_Attribute_Reference (Sloc, + Attribute_Name => Name_Pos, + Prefix => New_Reference_To (Base_Type (S), Sloc), + Expressions => New_List (Relocate_Node (Index))), + Type_Low_Bound (S), + Ttyp)); + else + Expr := Num; + end if; + + -- Now add lengths of preceding entries and entry families. + + Prev := First_Entity (Ttyp); + + while Chars (Prev) /= Chars (Ent) + or else (Ekind (Prev) /= Ekind (Ent)) + or else not Sem_Ch6.Type_Conformant (Ent, Prev) + loop + if Ekind (Prev) = E_Entry then + Set_Intval (Num, Intval (Num) + 1); + + elsif Ekind (Prev) = E_Entry_Family then + S := + Etype (Discrete_Subtype_Definition (Declaration_Node (Prev))); + Lo := Type_Low_Bound (S); + Hi := Type_High_Bound (S); + + Expr := + Make_Op_Add (Sloc, + Left_Opnd => Expr, + Right_Opnd => Family_Size (Sloc, Hi, Lo, Ttyp)); + + -- Other components are anonymous types to be ignored. + + else + null; + end if; + + Next_Entity (Prev); + end loop; + + return Expr; + end Entry_Index_Expression; + + --------------------------- + -- Establish_Task_Master -- + --------------------------- + + procedure Establish_Task_Master (N : Node_Id) is + Call : Node_Id; + + begin + if Restrictions (No_Task_Hierarchy) = False then + Call := Build_Runtime_Call (Sloc (N), RE_Enter_Master); + Prepend_To (Declarations (N), Call); + Analyze (Call); + end if; + end Establish_Task_Master; + + -------------------------------- + -- Expand_Accept_Declarations -- + -------------------------------- + + -- Part of the expansion of an accept statement involves the creation of + -- a declaration that can be referenced from the statement sequence of + -- the accept: + + -- Ann : Address; + + -- This declaration is inserted immediately before the accept statement + -- and it is important that it be inserted before the statements of the + -- statement sequence are analyzed. Thus it would be too late to create + -- this declaration in the Expand_N_Accept_Statement routine, which is + -- why there is a separate procedure to be called directly from Sem_Ch9. + + -- Ann is used to hold the address of the record containing the parameters + -- (see Expand_N_Entry_Call for more details on how this record is built). + -- References to the parameters do an unchecked conversion of this address + -- to a pointer to the required record type, and then access the field that + -- holds the value of the required parameter. The entity for the address + -- variable is held as the top stack element (i.e. the last element) of the + -- Accept_Address stack in the corresponding entry entity, and this element + -- must be set in place before the statements are processed. + + -- The above description applies to the case of a stand alone accept + -- statement, i.e. one not appearing as part of a select alternative. + + -- For the case of an accept that appears as part of a select alternative + -- of a selective accept, we must still create the declaration right away, + -- since Ann is needed immediately, but there is an important difference: + + -- The declaration is inserted before the selective accept, not before + -- the accept statement (which is not part of a list anyway, and so would + -- not accommodate inserted declarations) + + -- We only need one address variable for the entire selective accept. So + -- the Ann declaration is created only for the first accept alternative, + -- and subsequent accept alternatives reference the same Ann variable. + + -- We can distinguish the two cases by seeing whether the accept statement + -- is part of a list. If not, then it must be in an accept alternative. + + -- To expand the requeue statement, a label is provided at the end of + -- the accept statement or alternative of which it is a part, so that + -- the statement can be skipped after the requeue is complete. + -- This label is created here rather than during the expansion of the + -- accept statement, because it will be needed by any requeue + -- statements within the accept, which are expanded before the + -- accept. + + procedure Expand_Accept_Declarations (N : Node_Id; Ent : Entity_Id) is + Loc : constant Source_Ptr := Sloc (N); + Ann : Entity_Id := Empty; + Adecl : Node_Id; + Lab_Id : Node_Id; + Lab : Node_Id; + Ldecl : Node_Id; + Ldecl2 : Node_Id; + + begin + if Expander_Active then + + -- If we have no handled statement sequence, then build a dummy + -- sequence consisting of a null statement. This is only done if + -- pragma FIFO_Within_Priorities is specified. The issue here is + -- that even a null accept body has an effect on the called task + -- in terms of its position in the queue, so we cannot optimize + -- the context switch away. However, if FIFO_Within_Priorities + -- is not active, the optimization is legitimate, since we can + -- say that our dispatching policy (i.e. the default dispatching + -- policy) reorders the queue to be the same as just before the + -- call. In the absence of a specified dispatching policy, we are + -- allowed to modify queue orders for a given priority at will! + + if Opt.Task_Dispatching_Policy = 'F' and then + not Present (Handled_Statement_Sequence (N)) + then + Set_Handled_Statement_Sequence (N, + Make_Handled_Sequence_Of_Statements (Loc, + New_List (Make_Null_Statement (Loc)))); + end if; + + -- Create and declare two labels to be placed at the end of the + -- accept statement. The first label is used to allow requeues to + -- skip the remainder of entry processing. The second label is + -- used to skip the remainder of entry processing if the rendezvous + -- completes in the middle of the accept body. + + if Present (Handled_Statement_Sequence (N)) then + Lab_Id := Make_Identifier (Loc, New_Internal_Name ('L')); + Set_Entity (Lab_Id, + Make_Defining_Identifier (Loc, Chars (Lab_Id))); + Lab := Make_Label (Loc, Lab_Id); + Ldecl := + Make_Implicit_Label_Declaration (Loc, + Defining_Identifier => Entity (Lab_Id), + Label_Construct => Lab); + Append (Lab, Statements (Handled_Statement_Sequence (N))); + + Lab_Id := Make_Identifier (Loc, New_Internal_Name ('L')); + Set_Entity (Lab_Id, + Make_Defining_Identifier (Loc, Chars (Lab_Id))); + Lab := Make_Label (Loc, Lab_Id); + Ldecl2 := + Make_Implicit_Label_Declaration (Loc, + Defining_Identifier => Entity (Lab_Id), + Label_Construct => Lab); + Append (Lab, Statements (Handled_Statement_Sequence (N))); + + else + Ldecl := Empty; + Ldecl2 := Empty; + end if; + + -- Case of stand alone accept statement + + if Is_List_Member (N) then + + if Present (Handled_Statement_Sequence (N)) then + Ann := + Make_Defining_Identifier (Loc, + Chars => New_Internal_Name ('A')); + + Adecl := + Make_Object_Declaration (Loc, + Defining_Identifier => Ann, + Object_Definition => + New_Reference_To (RTE (RE_Address), Loc)); + + Insert_Before (N, Adecl); + Analyze (Adecl); + + Insert_Before (N, Ldecl); + Analyze (Ldecl); + + Insert_Before (N, Ldecl2); + Analyze (Ldecl2); + end if; + + -- Case of accept statement which is in an accept alternative + + else + declare + Acc_Alt : constant Node_Id := Parent (N); + Sel_Acc : constant Node_Id := Parent (Acc_Alt); + Alt : Node_Id; + + begin + pragma Assert (Nkind (Acc_Alt) = N_Accept_Alternative); + pragma Assert (Nkind (Sel_Acc) = N_Selective_Accept); + + -- ??? Consider a single label for select statements. + + if Present (Handled_Statement_Sequence (N)) then + Prepend (Ldecl2, + Statements (Handled_Statement_Sequence (N))); + Analyze (Ldecl2); + + Prepend (Ldecl, + Statements (Handled_Statement_Sequence (N))); + Analyze (Ldecl); + end if; + + -- Find first accept alternative of the selective accept. A + -- valid selective accept must have at least one accept in it. + + Alt := First (Select_Alternatives (Sel_Acc)); + + while Nkind (Alt) /= N_Accept_Alternative loop + Next (Alt); + end loop; + + -- If we are the first accept statement, then we have to + -- create the Ann variable, as for the stand alone case, + -- except that it is inserted before the selective accept. + -- Similarly, a label for requeue expansion must be + -- declared. + + if N = Accept_Statement (Alt) then + Ann := + Make_Defining_Identifier (Loc, New_Internal_Name ('A')); + + Adecl := + Make_Object_Declaration (Loc, + Defining_Identifier => Ann, + Object_Definition => + New_Reference_To (RTE (RE_Address), Loc)); + + Insert_Before (Sel_Acc, Adecl); + Analyze (Adecl); + + -- If we are not the first accept statement, then find the + -- Ann variable allocated by the first accept and use it. + + else + Ann := + Node (Last_Elmt (Accept_Address + (Entity (Entry_Direct_Name (Accept_Statement (Alt)))))); + end if; + end; + end if; + + -- Merge here with Ann either created or referenced, and Adecl + -- pointing to the corresponding declaration. Remaining processing + -- is the same for the two cases. + + if Present (Ann) then + Append_Elmt (Ann, Accept_Address (Ent)); + end if; + end if; + end Expand_Accept_Declarations; + + --------------------------------------------- + -- Expand_Access_Protected_Subprogram_Type -- + --------------------------------------------- + + procedure Expand_Access_Protected_Subprogram_Type (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Comps : List_Id; + T : constant Entity_Id := Defining_Identifier (N); + D_T : constant Entity_Id := Designated_Type (T); + D_T2 : constant Entity_Id := Make_Defining_Identifier + (Loc, New_Internal_Name ('D')); + E_T : constant Entity_Id := Make_Defining_Identifier + (Loc, New_Internal_Name ('E')); + P_List : constant List_Id := Build_Protected_Spec + (N, RTE (RE_Address), False, D_T); + Decl1 : Node_Id; + Decl2 : Node_Id; + Def1 : Node_Id; + + begin + -- Create access to protected subprogram with full signature. + + if Nkind (Type_Definition (N)) = N_Access_Function_Definition then + Def1 := + Make_Access_Function_Definition (Loc, + Parameter_Specifications => P_List, + Subtype_Mark => New_Copy (Subtype_Mark (Type_Definition (N)))); + + else + Def1 := + Make_Access_Procedure_Definition (Loc, + Parameter_Specifications => P_List); + end if; + + Decl1 := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => D_T2, + Type_Definition => Def1); + + Insert_After (N, Decl1); + + -- Create Equivalent_Type, a record with two components for an + -- an access to object an an access to subprogram. + + Comps := New_List ( + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, New_Internal_Name ('P')), + Subtype_Indication => + New_Occurrence_Of (RTE (RE_Address), Loc)), + + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, New_Internal_Name ('S')), + Subtype_Indication => + New_Occurrence_Of (D_T2, Loc))); + + Decl2 := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => E_T, + Type_Definition => + Make_Record_Definition (Loc, + Component_List => + Make_Component_List (Loc, + Component_Items => Comps))); + + Insert_After (Decl1, Decl2); + Set_Equivalent_Type (T, E_T); + + end Expand_Access_Protected_Subprogram_Type; + + -------------------------- + -- Expand_Entry_Barrier -- + -------------------------- + + procedure Expand_Entry_Barrier (N : Node_Id; Ent : Entity_Id) is + Loc : constant Source_Ptr := Sloc (N); + Func : Node_Id; + B_F : Node_Id; + Prot : constant Entity_Id := Scope (Ent); + Spec_Decl : Node_Id := Parent (Prot); + Body_Decl : Node_Id; + Cond : Node_Id := Condition (Entry_Body_Formal_Part (N)); + + begin + -- The body of the entry barrier must be analyzed in the context of + -- the protected object, but its scope is external to it, just as any + -- other unprotected version of a protected operation. The specification + -- has been produced when the protected type declaration was elaborated. + -- We build the body, insert it in the enclosing scope, but analyze it + -- in the current context. A more uniform approach would be to treat a + -- barrier just as a protected function, and discard the protected + -- version of it because it is never called. + + if Expander_Active then + B_F := Build_Barrier_Function (N, Ent, Prot); + Func := Barrier_Function (Ent); + Set_Corresponding_Spec (B_F, Func); + + Body_Decl := Parent (Corresponding_Body (Spec_Decl)); + + if Nkind (Parent (Body_Decl)) = N_Subunit then + Body_Decl := Corresponding_Stub (Parent (Body_Decl)); + end if; + + Insert_Before_And_Analyze (Body_Decl, B_F); + + Update_Prival_Subtypes (B_F); + + Set_Privals (Spec_Decl, N, Loc); + Set_Discriminals (Spec_Decl, N, Loc); + Set_Scope (Func, Scope (Prot)); + else + Analyze (Cond); + end if; + + -- The Ravenscar profile restricts barriers to simple variables + -- declared within the protected object. We also allow Boolean + -- constants, since these appear in several published examples + -- and are also allowed by the Aonix compiler. + + -- Note that after analysis variables in this context will be + -- replaced by the corresponding prival, that is to say a renaming + -- of a selected component of the form _Object.Var. If expansion is + -- disabled, as within a generic, we check that the entity appears in + -- the current scope. + + if Is_Entity_Name (Cond) then + + if Entity (Cond) = Standard_False + or else + Entity (Cond) = Standard_True + then + return; + + elsif not Expander_Active + and then Scope (Entity (Cond)) = Current_Scope + then + return; + + elsif Present (Renamed_Object (Entity (Cond))) + and then + Nkind (Renamed_Object (Entity (Cond))) = N_Selected_Component + and then + Chars (Prefix (Renamed_Object (Entity (Cond)))) = Name_uObject + then + return; + end if; + end if; + + -- It is not a boolean variable or literal, so check the restriction + + Check_Restriction (Boolean_Entry_Barriers, Cond); + end Expand_Entry_Barrier; + + ------------------------------------ + -- Expand_Entry_Body_Declarations -- + ------------------------------------ + + procedure Expand_Entry_Body_Declarations (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Index_Spec : Node_Id; + + begin + if Expander_Active then + + -- Expand entry bodies corresponding to entry families + -- by assigning a placeholder for the constant that will + -- be used to expand references to the entry index parameter. + + Index_Spec := + Entry_Index_Specification (Entry_Body_Formal_Part (N)); + + if Present (Index_Spec) then + Set_Entry_Index_Constant ( + Defining_Identifier (Index_Spec), + Make_Defining_Identifier (Loc, New_Internal_Name ('I'))); + end if; + + end if; + end Expand_Entry_Body_Declarations; + + ------------------------------ + -- Expand_N_Abort_Statement -- + ------------------------------ + + -- Expand abort T1, T2, .. Tn; into: + -- Abort_Tasks (Task_List'(1 => T1.Task_Id, 2 => T2.Task_Id ...)) + + procedure Expand_N_Abort_Statement (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Tlist : constant List_Id := Names (N); + Count : Nat; + Aggr : Node_Id; + Tasknm : Node_Id; + + begin + Aggr := Make_Aggregate (Loc, Component_Associations => New_List); + Count := 0; + + Tasknm := First (Tlist); + + while Present (Tasknm) loop + Count := Count + 1; + Append_To (Component_Associations (Aggr), + Make_Component_Association (Loc, + Choices => New_List ( + Make_Integer_Literal (Loc, Count)), + Expression => Concurrent_Ref (Tasknm))); + Next (Tasknm); + end loop; + + Rewrite (N, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Abort_Tasks), Loc), + Parameter_Associations => New_List ( + Make_Qualified_Expression (Loc, + Subtype_Mark => New_Reference_To (RTE (RE_Task_List), Loc), + Expression => Aggr)))); + + Analyze (N); + + end Expand_N_Abort_Statement; + + ------------------------------- + -- Expand_N_Accept_Statement -- + ------------------------------- + + -- This procedure handles expansion of accept statements that stand + -- alone, i.e. they are not part of an accept alternative. The expansion + -- of accept statement in accept alternatives is handled by the routines + -- Expand_N_Accept_Alternative and Expand_N_Selective_Accept. The + -- following description applies only to stand alone accept statements. + + -- If there is no handled statement sequence, or only null statements, + -- then this is called a trivial accept, and the expansion is: + + -- Accept_Trivial (entry-index) + + -- If there is a handled statement sequence, then the expansion is: + + -- Ann : Address; + -- {Lnn : Label} + + -- begin + -- begin + -- Accept_Call (entry-index, Ann); + -- <statement sequence from N_Accept_Statement node> + -- Complete_Rendezvous; + -- <<Lnn>> + -- + -- exception + -- when ... => + -- <exception handler from N_Accept_Statement node> + -- Complete_Rendezvous; + -- when ... => + -- <exception handler from N_Accept_Statement node> + -- Complete_Rendezvous; + -- ... + -- end; + + -- exception + -- when all others => + -- Exceptional_Complete_Rendezvous (Get_GNAT_Exception); + -- end; + + -- The first three declarations were already inserted ahead of the + -- accept statement by the Expand_Accept_Declarations procedure, which + -- was called directly from the semantics during analysis of the accept. + -- statement, before analyzing its contained statements. + + -- The declarations from the N_Accept_Statement, as noted in Sinfo, come + -- from possible expansion activity (the original source of course does + -- not have any declarations associated with the accept statement, since + -- an accept statement has no declarative part). In particular, if the + -- expander is active, the first such declaration is the declaration of + -- the Accept_Params_Ptr entity (see Sem_Ch9.Analyze_Accept_Statement). + -- + -- The two blocks are merged into a single block if the inner block has + -- no exception handlers, but otherwise two blocks are required, since + -- exceptions might be raised in the exception handlers of the inner + -- block, and Exceptional_Complete_Rendezvous must be called. + + procedure Expand_N_Accept_Statement (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Stats : constant Node_Id := Handled_Statement_Sequence (N); + Ename : constant Node_Id := Entry_Direct_Name (N); + Eindx : constant Node_Id := Entry_Index (N); + Eent : constant Entity_Id := Entity (Ename); + Acstack : constant Elist_Id := Accept_Address (Eent); + Ann : constant Entity_Id := Node (Last_Elmt (Acstack)); + Ttyp : constant Entity_Id := Etype (Scope (Eent)); + Call : Node_Id; + Block : Node_Id; + + function Null_Statements (Stats : List_Id) return Boolean; + -- Check for null statement sequence (i.e a list of labels and + -- null statements) + + function Null_Statements (Stats : List_Id) return Boolean is + Stmt : Node_Id; + + begin + Stmt := First (Stats); + while Nkind (Stmt) /= N_Empty + and then (Nkind (Stmt) = N_Null_Statement + or else + Nkind (Stmt) = N_Label) + loop + Next (Stmt); + end loop; + + return Nkind (Stmt) = N_Empty; + end Null_Statements; + + -- Start of processing for Expand_N_Accept_Statement + + begin + -- If accept statement is not part of a list, then its parent must be + -- an accept alternative, and, as described above, we do not do any + -- expansion for such accept statements at this level. + + if not Is_List_Member (N) then + pragma Assert (Nkind (Parent (N)) = N_Accept_Alternative); + return; + + -- Trivial accept case (no statement sequence, or null statements). + -- If the accept statement has declarations, then just insert them + -- before the procedure call. + + -- We avoid this optimization when FIFO_Within_Priorities is active, + -- since it is not correct according to annex D semantics. The problem + -- is that the call is required to reorder the acceptors position on + -- its ready queue, even though there is nothing to be done. However, + -- if no policy is specified, then we decide that our dispatching + -- policy always reorders the queue right after the RV to look the + -- way they were just before the RV. Since we are allowed to freely + -- reorder same-priority queues (this is part of what dispatching + -- policies are all about), the optimization is legitimate. + + elsif Opt.Task_Dispatching_Policy /= 'F' + and then (No (Stats) or else Null_Statements (Statements (Stats))) + then + if Present (Declarations (N)) then + Insert_Actions (N, Declarations (N)); + end if; + + Rewrite (N, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Accept_Trivial), Loc), + Parameter_Associations => New_List ( + Entry_Index_Expression (Loc, Entity (Ename), Eindx, Ttyp)))); + + Analyze (N); + + -- Discard Entry_Address that was created for it, so it will not be + -- emitted if this accept statement is in the statement part of a + -- delay alternative. + + if Present (Stats) then + Remove_Last_Elmt (Acstack); + end if; + + -- Case of statement sequence present + + else + -- Construct the block, using the declarations from the accept + -- statement if any to initialize the declarations of the block. + + Block := + Make_Block_Statement (Loc, + Declarations => Declarations (N), + Handled_Statement_Sequence => Build_Accept_Body (N)); + + -- Prepend call to Accept_Call to main statement sequence + + Call := + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Accept_Call), Loc), + Parameter_Associations => New_List ( + Entry_Index_Expression (Loc, Entity (Ename), Eindx, Ttyp), + New_Reference_To (Ann, Loc))); + + Prepend (Call, Statements (Stats)); + Analyze (Call); + + -- Replace the accept statement by the new block + + Rewrite (N, Block); + Analyze (N); + + -- Last step is to unstack the Accept_Address value + + Remove_Last_Elmt (Acstack); + end if; + + end Expand_N_Accept_Statement; + + ---------------------------------- + -- Expand_N_Asynchronous_Select -- + ---------------------------------- + + -- This procedure assumes that the trigger statement is an entry + -- call. A delay alternative should already have been expanded + -- into an entry call to the appropriate delay object Wait entry. + + -- If the trigger is a task entry call, the select is implemented + -- with Task_Entry_Call: + + -- declare + -- B : Boolean; + -- C : Boolean; + -- P : parms := (parm, parm, parm); + -- + -- -- Clean is added by Exp_Ch7.Expand_Cleanup_Actions. + -- + -- procedure _clean is + -- begin + -- ... + -- Cancel_Task_Entry_Call (C); + -- ... + -- end _clean; + -- begin + -- Abort_Defer; + -- Task_Entry_Call + -- (acceptor-task, + -- entry-index, + -- P'Address, + -- Asynchronous_Call, + -- B); + -- begin + -- begin + -- Abort_Undefer; + -- abortable-part + -- at end + -- _clean; -- Added by Exp_Ch7.Expand_Cleanup_Actions. + -- end; + -- exception + -- when Abort_Signal => Abort_Undefer; + -- end; + -- parm := P.param; + -- parm := P.param; + -- ... + -- if not C then + -- triggered-statements + -- end if; + -- end; + + -- Note that Build_Simple_Entry_Call is used to expand the entry + -- of the asynchronous entry call (by the + -- Expand_N_Entry_Call_Statement procedure) as follows: + + -- declare + -- P : parms := (parm, parm, parm); + -- begin + -- Call_Simple (acceptor-task, entry-index, P'Address); + -- parm := P.param; + -- parm := P.param; + -- ... + -- end; + + -- so the task at hand is to convert the latter expansion into the former + + -- If the trigger is a protected entry call, the select is + -- implemented with Protected_Entry_Call: + + -- declare + -- P : E1_Params := (param, param, param); + -- Bnn : Communications_Block; + -- begin + -- declare + -- + -- -- Clean is added by Exp_Ch7.Expand_Cleanup_Actions. + -- + -- procedure _clean is + -- begin + -- ... + -- if Enqueued (Bnn) then + -- Cancel_Protected_Entry_Call (Bnn); + -- end if; + -- ... + -- end _clean; + -- begin + -- begin + -- Protected_Entry_Call ( + -- Object => po._object'Access, + -- E => <entry index>; + -- Uninterpreted_Data => P'Address; + -- Mode => Asynchronous_Call; + -- Block => Bnn); + -- if Enqueued (Bnn) then + -- <abortable part> + -- end if; + -- at end + -- _clean; -- Added by Exp_Ch7.Expand_Cleanup_Actions. + -- end; + -- exception + -- when Abort_Signal => + -- Abort_Undefer; + -- null; + -- end; + -- if not Cancelled (Bnn) then + -- triggered statements + -- end if; + -- end; + + -- Build_Simple_Entry_Call is used to expand the all to a simple + -- protected entry call: + + -- declare + -- P : E1_Params := (param, param, param); + -- Bnn : Communications_Block; + + -- begin + -- Protected_Entry_Call ( + -- Object => po._object'Access, + -- E => <entry index>; + -- Uninterpreted_Data => P'Address; + -- Mode => Simple_Call; + -- Block => Bnn); + -- parm := P.param; + -- parm := P.param; + -- ... + -- end; + + -- The job is to convert this to the asynchronous form. + + -- If the trigger is a delay statement, it will have been expanded + -- into a call to one of the GNARL delay procedures. This routine + -- will convert this into a protected entry call on a delay object + -- and then continue processing as for a protected entry call trigger. + -- This requires declaring a Delay_Block object and adding a pointer + -- to this object to the parameter list of the delay procedure to form + -- the parameter list of the entry call. This object is used by + -- the runtime to queue the delay request. + + -- For a description of the use of P and the assignments after the + -- call, see Expand_N_Entry_Call_Statement. + + procedure Expand_N_Asynchronous_Select (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Trig : constant Node_Id := Triggering_Alternative (N); + Abrt : constant Node_Id := Abortable_Part (N); + Tstats : constant List_Id := Statements (Trig); + + Ecall : Node_Id; + Astats : List_Id := Statements (Abrt); + Concval : Node_Id; + Ename : Node_Id; + Index : Node_Id; + Hdle : List_Id; + Decls : List_Id; + Decl : Node_Id; + Parms : List_Id; + Parm : Node_Id; + Call : Node_Id; + Stmts : List_Id; + Enqueue_Call : Node_Id; + Stmt : Node_Id; + B : Entity_Id; + Pdef : Entity_Id; + Dblock_Ent : Entity_Id; + N_Orig : Node_Id; + Abortable_Block : Node_Id; + Cancel_Param : Entity_Id; + Blkent : Entity_Id; + Target_Undefer : RE_Id; + Undefer_Args : List_Id := No_List; + + begin + Blkent := Make_Defining_Identifier (Loc, New_Internal_Name ('A')); + Ecall := Triggering_Statement (Trig); + + -- The arguments in the call may require dynamic allocation, and the + -- call statement may have been transformed into a block. The block + -- may contain additional declarations for internal entities, and the + -- original call is found by sequential search. + + if Nkind (Ecall) = N_Block_Statement then + Ecall := First (Statements (Handled_Statement_Sequence (Ecall))); + + while Nkind (Ecall) /= N_Procedure_Call_Statement + and then Nkind (Ecall) /= N_Entry_Call_Statement + loop + Next (Ecall); + end loop; + end if; + + -- If a delay was used as a trigger, it will have been expanded + -- into a procedure call. Convert it to the appropriate sequence of + -- statements, similar to what is done for a task entry call. + -- Note that this currently supports only Duration, Real_Time.Time, + -- and Calendar.Time. + + if Nkind (Ecall) = N_Procedure_Call_Statement then + + -- Add a Delay_Block object to the parameter list of the + -- delay procedure to form the parameter list of the Wait + -- entry call. + + Dblock_Ent := Make_Defining_Identifier (Loc, New_Internal_Name ('D')); + + Pdef := Entity (Name (Ecall)); + + if Is_RTE (Pdef, RO_CA_Delay_For) then + Enqueue_Call := New_Reference_To (RTE (RE_Enqueue_Duration), Loc); + + elsif Is_RTE (Pdef, RO_CA_Delay_Until) then + Enqueue_Call := New_Reference_To (RTE (RE_Enqueue_Calendar), Loc); + + else pragma Assert (Is_RTE (Pdef, RO_RT_Delay_Until)); + Enqueue_Call := New_Reference_To (RTE (RE_Enqueue_RT), Loc); + end if; + + Append_To (Parameter_Associations (Ecall), + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Dblock_Ent, Loc), + Attribute_Name => Name_Unchecked_Access)); + + -- Create the inner block to protect the abortable part. + + Hdle := New_List ( + Make_Exception_Handler (Loc, + Exception_Choices => + New_List (New_Reference_To (Stand.Abort_Signal, Loc)), + Statements => New_List ( + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc))))); + + Prepend_To (Astats, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc))); + + Abortable_Block := + Make_Block_Statement (Loc, + Identifier => New_Reference_To (Blkent, Loc), + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => Astats), + Has_Created_Identifier => True, + Is_Asynchronous_Call_Block => True); + + -- Append call to if Enqueue (When, DB'Unchecked_Access) then + + Rewrite (Ecall, + Make_Implicit_If_Statement (N, + Condition => Make_Function_Call (Loc, + Name => Enqueue_Call, + Parameter_Associations => Parameter_Associations (Ecall)), + Then_Statements => + New_List (Make_Block_Statement (Loc, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List ( + Make_Implicit_Label_Declaration (Loc, + Defining_Identifier => Blkent, + Label_Construct => Abortable_Block), + Abortable_Block), + Exception_Handlers => Hdle))))); + + Stmts := New_List (Ecall); + + -- Construct statement sequence for new block + + Append_To (Stmts, + Make_Implicit_If_Statement (N, + Condition => Make_Function_Call (Loc, + Name => New_Reference_To ( + RTE (RE_Timed_Out), Loc), + Parameter_Associations => New_List ( + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Dblock_Ent, Loc), + Attribute_Name => Name_Unchecked_Access))), + Then_Statements => Tstats)); + + -- The result is the new block + + Set_Entry_Cancel_Parameter (Blkent, Dblock_Ent); + + Rewrite (N, + Make_Block_Statement (Loc, + Declarations => New_List ( + Make_Object_Declaration (Loc, + Defining_Identifier => Dblock_Ent, + Aliased_Present => True, + Object_Definition => New_Reference_To ( + RTE (RE_Delay_Block), Loc))), + + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, Stmts))); + + Analyze (N); + return; + + else + N_Orig := N; + end if; + + Extract_Entry (Ecall, Concval, Ename, Index); + Build_Simple_Entry_Call (Ecall, Concval, Ename, Index); + + Stmts := Statements (Handled_Statement_Sequence (Ecall)); + Decls := Declarations (Ecall); + + if Is_Protected_Type (Etype (Concval)) then + + -- Get the declarations of the block expanded from the entry call + + Decl := First (Decls); + while Present (Decl) + and then (Nkind (Decl) /= N_Object_Declaration + or else not Is_RTE + (Etype (Object_Definition (Decl)), RE_Communication_Block)) + loop + Next (Decl); + end loop; + + pragma Assert (Present (Decl)); + Cancel_Param := Defining_Identifier (Decl); + + -- Change the mode of the Protected_Entry_Call call. + -- Protected_Entry_Call ( + -- Object => po._object'Access, + -- E => <entry index>; + -- Uninterpreted_Data => P'Address; + -- Mode => Asynchronous_Call; + -- Block => Bnn); + + Stmt := First (Stmts); + + -- Skip assignments to temporaries created for in-out parameters. + -- This makes unwarranted assumptions about the shape of the expanded + -- tree for the call, and should be cleaned up ??? + + while Nkind (Stmt) /= N_Procedure_Call_Statement loop + Next (Stmt); + end loop; + + Call := Stmt; + + Parm := First (Parameter_Associations (Call)); + while Present (Parm) + and then not Is_RTE (Etype (Parm), RE_Call_Modes) + loop + Next (Parm); + end loop; + + pragma Assert (Present (Parm)); + Rewrite (Parm, New_Reference_To (RTE (RE_Asynchronous_Call), Loc)); + Analyze (Parm); + + -- Append an if statement to execute the abortable part. + -- if Enqueued (Bnn) then + + Append_To (Stmts, + Make_Implicit_If_Statement (N, + Condition => Make_Function_Call (Loc, + Name => New_Reference_To ( + RTE (RE_Enqueued), Loc), + Parameter_Associations => New_List ( + New_Reference_To (Cancel_Param, Loc))), + Then_Statements => Astats)); + + Abortable_Block := + Make_Block_Statement (Loc, + Identifier => New_Reference_To (Blkent, Loc), + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => Stmts), + Has_Created_Identifier => True, + Is_Asynchronous_Call_Block => True); + + -- For the JVM call Update_Exception instead of Abort_Undefer. + -- See 4jexcept.ads for an explanation. + + if Hostparm.Java_VM then + Target_Undefer := RE_Update_Exception; + Undefer_Args := + New_List (Make_Function_Call (Loc, + Name => New_Occurrence_Of + (RTE (RE_Current_Target_Exception), Loc))); + else + Target_Undefer := RE_Abort_Undefer; + end if; + + Stmts := New_List ( + Make_Block_Statement (Loc, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List ( + Make_Implicit_Label_Declaration (Loc, + Defining_Identifier => Blkent, + Label_Construct => Abortable_Block), + Abortable_Block), + + -- exception + + Exception_Handlers => New_List ( + Make_Exception_Handler (Loc, + + -- when Abort_Signal => + -- Abort_Undefer.all; + + Exception_Choices => + New_List (New_Reference_To (Stand.Abort_Signal, Loc)), + Statements => New_List ( + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To ( + RTE (Target_Undefer), Loc), + Parameter_Associations => Undefer_Args)))))), + + -- if not Cancelled (Bnn) then + -- triggered statements + -- end if; + + Make_Implicit_If_Statement (N, + Condition => Make_Op_Not (Loc, + Right_Opnd => + Make_Function_Call (Loc, + Name => New_Occurrence_Of (RTE (RE_Cancelled), Loc), + Parameter_Associations => New_List ( + New_Occurrence_Of (Cancel_Param, Loc)))), + Then_Statements => Tstats)); + + -- Asynchronous task entry call + + else + if No (Decls) then + Decls := New_List; + end if; + + B := Make_Defining_Identifier (Loc, Name_uB); + + -- Insert declaration of B in declarations of existing block + + Prepend_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => B, + Object_Definition => New_Reference_To (Standard_Boolean, Loc))); + + Cancel_Param := Make_Defining_Identifier (Loc, Name_uC); + + -- Insert declaration of C in declarations of existing block + + Prepend_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => Cancel_Param, + Object_Definition => New_Reference_To (Standard_Boolean, Loc))); + + -- Remove and save the call to Call_Simple. + + Stmt := First (Stmts); + + -- Skip assignments to temporaries created for in-out parameters. + -- This makes unwarranted assumptions about the shape of the expanded + -- tree for the call, and should be cleaned up ??? + + while Nkind (Stmt) /= N_Procedure_Call_Statement loop + Next (Stmt); + end loop; + + Call := Stmt; + + -- Create the inner block to protect the abortable part. + + Hdle := New_List ( + Make_Exception_Handler (Loc, + Exception_Choices => + New_List (New_Reference_To (Stand.Abort_Signal, Loc)), + Statements => New_List ( + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc))))); + + Prepend_To (Astats, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc))); + + Abortable_Block := + Make_Block_Statement (Loc, + Identifier => New_Reference_To (Blkent, Loc), + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => Astats), + Has_Created_Identifier => True, + Is_Asynchronous_Call_Block => True); + + Insert_After (Call, + Make_Block_Statement (Loc, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => New_List ( + Make_Implicit_Label_Declaration (Loc, + Defining_Identifier => Blkent, + Label_Construct => Abortable_Block), + Abortable_Block), + Exception_Handlers => Hdle))); + + -- Create new call statement + + Parms := Parameter_Associations (Call); + Append_To (Parms, New_Reference_To (RTE (RE_Asynchronous_Call), Loc)); + Append_To (Parms, New_Reference_To (B, Loc)); + Rewrite (Call, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Task_Entry_Call), Loc), + Parameter_Associations => Parms)); + + -- Construct statement sequence for new block + + Append_To (Stmts, + Make_Implicit_If_Statement (N, + Condition => Make_Op_Not (Loc, + New_Reference_To (Cancel_Param, Loc)), + Then_Statements => Tstats)); + + -- Protected the call against abortion + + Prepend_To (Stmts, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Abort_Defer), Loc), + Parameter_Associations => Empty_List)); + end if; + + Set_Entry_Cancel_Parameter (Blkent, Cancel_Param); + + -- The result is the new block + + Rewrite (N_Orig, + Make_Block_Statement (Loc, + Declarations => Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, Stmts))); + + Analyze (N_Orig); + + end Expand_N_Asynchronous_Select; + + ------------------------------------- + -- Expand_N_Conditional_Entry_Call -- + ------------------------------------- + + -- The conditional task entry call is converted to a call to + -- Task_Entry_Call: + + -- declare + -- B : Boolean; + -- P : parms := (parm, parm, parm); + + -- begin + -- Task_Entry_Call + -- (acceptor-task, + -- entry-index, + -- P'Address, + -- Conditional_Call, + -- B); + -- parm := P.param; + -- parm := P.param; + -- ... + -- if B then + -- normal-statements + -- else + -- else-statements + -- end if; + -- end; + + -- For a description of the use of P and the assignments after the + -- call, see Expand_N_Entry_Call_Statement. Note that the entry call + -- of the conditional entry call has already been expanded (by the + -- Expand_N_Entry_Call_Statement procedure) as follows: + + -- declare + -- P : parms := (parm, parm, parm); + -- begin + -- ... info for in-out parameters + -- Call_Simple (acceptor-task, entry-index, P'Address); + -- parm := P.param; + -- parm := P.param; + -- ... + -- end; + + -- so the task at hand is to convert the latter expansion into the former + + -- The conditional protected entry call is converted to a call to + -- Protected_Entry_Call: + + -- declare + -- P : parms := (parm, parm, parm); + -- Bnn : Communications_Block; + + -- begin + -- Protected_Entry_Call ( + -- Object => po._object'Access, + -- E => <entry index>; + -- Uninterpreted_Data => P'Address; + -- Mode => Conditional_Call; + -- Block => Bnn); + -- parm := P.param; + -- parm := P.param; + -- ... + -- if Cancelled (Bnn) then + -- else-statements + -- else + -- normal-statements + -- end if; + -- end; + + -- As for tasks, the entry call of the conditional entry call has + -- already been expanded (by the Expand_N_Entry_Call_Statement procedure) + -- as follows: + + -- declare + -- P : E1_Params := (param, param, param); + -- Bnn : Communications_Block; + + -- begin + -- Protected_Entry_Call ( + -- Object => po._object'Access, + -- E => <entry index>; + -- Uninterpreted_Data => P'Address; + -- Mode => Simple_Call; + -- Block => Bnn); + -- parm := P.param; + -- parm := P.param; + -- ... + -- end; + + procedure Expand_N_Conditional_Entry_Call (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Alt : constant Node_Id := Entry_Call_Alternative (N); + Blk : Node_Id := Entry_Call_Statement (Alt); + Transient_Blk : Node_Id; + + Parms : List_Id; + Parm : Node_Id; + Call : Node_Id; + Stmts : List_Id; + B : Entity_Id; + Decl : Node_Id; + Stmt : Node_Id; + + begin + -- As described above, The entry alternative is transformed into a + -- block that contains the gnulli call, and possibly assignment + -- statments for in-out parameters. The gnulli call may itself be + -- rewritten into a transient block if some unconstrained parameters + -- require it. We need to retrieve the call to complete its parameter + -- list. + + Transient_Blk := + First_Real_Statement (Handled_Statement_Sequence (Blk)); + + if Present (Transient_Blk) + and then + Nkind (Transient_Blk) = N_Block_Statement + then + Blk := Transient_Blk; + end if; + + Stmts := Statements (Handled_Statement_Sequence (Blk)); + + Stmt := First (Stmts); + + while Nkind (Stmt) /= N_Procedure_Call_Statement loop + Next (Stmt); + end loop; + + Call := Stmt; + + Parms := Parameter_Associations (Call); + + if Is_RTE (Entity (Name (Call)), RE_Protected_Entry_Call) then + + -- Substitute Conditional_Entry_Call for Simple_Call + -- parameter. + + Parm := First (Parms); + while Present (Parm) + and then not Is_RTE (Etype (Parm), RE_Call_Modes) + loop + Next (Parm); + end loop; + + pragma Assert (Present (Parm)); + Rewrite (Parm, New_Reference_To (RTE (RE_Conditional_Call), Loc)); + + Analyze (Parm); + + -- Find the Communication_Block parameter for the call + -- to the Cancelled function. + + Decl := First (Declarations (Blk)); + while Present (Decl) + and then not + Is_RTE (Etype (Object_Definition (Decl)), RE_Communication_Block) + loop + Next (Decl); + end loop; + + -- Add an if statement to execute the else part if the call + -- does not succeed (as indicated by the Cancelled predicate). + + Append_To (Stmts, + Make_Implicit_If_Statement (N, + Condition => Make_Function_Call (Loc, + Name => New_Reference_To (RTE (RE_Cancelled), Loc), + Parameter_Associations => New_List ( + New_Reference_To (Defining_Identifier (Decl), Loc))), + Then_Statements => Else_Statements (N), + Else_Statements => Statements (Alt))); + + else + B := Make_Defining_Identifier (Loc, Name_uB); + + -- Insert declaration of B in declarations of existing block + + if No (Declarations (Blk)) then + Set_Declarations (Blk, New_List); + end if; + + Prepend_To (Declarations (Blk), + Make_Object_Declaration (Loc, + Defining_Identifier => B, + Object_Definition => New_Reference_To (Standard_Boolean, Loc))); + + -- Create new call statement + + Append_To (Parms, New_Reference_To (RTE (RE_Conditional_Call), Loc)); + Append_To (Parms, New_Reference_To (B, Loc)); + + Rewrite (Call, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Task_Entry_Call), Loc), + Parameter_Associations => Parms)); + + -- Construct statement sequence for new block + + Append_To (Stmts, + Make_Implicit_If_Statement (N, + Condition => New_Reference_To (B, Loc), + Then_Statements => Statements (Alt), + Else_Statements => Else_Statements (N))); + + end if; + + -- The result is the new block + + Rewrite (N, + Make_Block_Statement (Loc, + Declarations => Declarations (Blk), + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, Stmts))); + + Analyze (N); + + end Expand_N_Conditional_Entry_Call; + + --------------------------------------- + -- Expand_N_Delay_Relative_Statement -- + --------------------------------------- + + -- Delay statement is implemented as a procedure call to Delay_For + -- defined in Ada.Calendar.Delays in order to reduce the overhead of + -- simple delays imposed by the use of Protected Objects. + + procedure Expand_N_Delay_Relative_Statement (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + + begin + Rewrite (N, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RO_CA_Delay_For), Loc), + Parameter_Associations => New_List (Expression (N)))); + Analyze (N); + end Expand_N_Delay_Relative_Statement; + + ------------------------------------ + -- Expand_N_Delay_Until_Statement -- + ------------------------------------ + + -- Delay Until statement is implemented as a procedure call to + -- Delay_Until defined in Ada.Calendar.Delays and Ada.Real_Time.Delays. + + procedure Expand_N_Delay_Until_Statement (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Typ : Entity_Id; + + begin + if Is_RTE (Base_Type (Etype (Expression (N))), RO_CA_Time) then + Typ := RTE (RO_CA_Delay_Until); + else + Typ := RTE (RO_RT_Delay_Until); + end if; + + Rewrite (N, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (Typ, Loc), + Parameter_Associations => New_List (Expression (N)))); + + Analyze (N); + end Expand_N_Delay_Until_Statement; + + ------------------------- + -- Expand_N_Entry_Body -- + ------------------------- + + procedure Expand_N_Entry_Body (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Next_Op : Node_Id; + Dec : Node_Id := Parent (Current_Scope); + Ent_Formals : Node_Id := Entry_Body_Formal_Part (N); + Index_Spec : Node_Id := Entry_Index_Specification (Ent_Formals); + + begin + -- Add the renamings for private declarations and discriminants. + + Add_Discriminal_Declarations + (Declarations (N), Defining_Identifier (Dec), Name_uObject, Loc); + Add_Private_Declarations + (Declarations (N), Defining_Identifier (Dec), Name_uObject, Loc); + + if Present (Index_Spec) then + Append_List_To (Declarations (N), + Index_Constant_Declaration + (N, Defining_Identifier (Index_Spec), Defining_Identifier (Dec))); + end if; + + -- Associate privals and discriminals with the next protected + -- operation body to be expanded. These are used to expand + -- references to private data objects and discriminants, + -- respectively. + + Next_Op := Next_Protected_Operation (N); + + if Present (Next_Op) then + Set_Privals (Dec, Next_Op, Loc); + Set_Discriminals (Dec, Next_Op, Loc); + end if; + + end Expand_N_Entry_Body; + + ----------------------------------- + -- Expand_N_Entry_Call_Statement -- + ----------------------------------- + + -- An entry call is expanded into GNARLI calls to implement + -- a simple entry call (see Build_Simple_Entry_Call). + + procedure Expand_N_Entry_Call_Statement (N : Node_Id) is + Concval : Node_Id; + Ename : Node_Id; + Index : Node_Id; + + begin + -- If this entry call is part of an asynchronous select, don't + -- expand it here; it will be expanded with the select statement. + -- Don't expand timed entry calls either, as they are translated + -- into asynchronous entry calls. + + -- ??? This whole approach is questionable; it may be better + -- to go back to allowing the expansion to take place and then + -- attempting to fix it up in Expand_N_Asynchronous_Select. + -- The tricky part is figuring out whether the expanded + -- call is on a task or protected entry. + + if (Nkind (Parent (N)) /= N_Triggering_Alternative + or else N /= Triggering_Statement (Parent (N))) + and then (Nkind (Parent (N)) /= N_Entry_Call_Alternative + or else N /= Entry_Call_Statement (Parent (N)) + or else Nkind (Parent (Parent (N))) /= N_Timed_Entry_Call) + then + Extract_Entry (N, Concval, Ename, Index); + Build_Simple_Entry_Call (N, Concval, Ename, Index); + end if; + + end Expand_N_Entry_Call_Statement; + + -------------------------------- + -- Expand_N_Entry_Declaration -- + -------------------------------- + + -- If there are parameters, then first, each of the formals is marked + -- by setting Is_Entry_Formal. Next a record type is built which is + -- used to hold the parameter values. The name of this record type is + -- entryP where entry is the name of the entry, with an additional + -- corresponding access type called entryPA. The record type has matching + -- components for each formal (the component names are the same as the + -- formal names). For elementary types, the component type matches the + -- formal type. For composite types, an access type is declared (with + -- the name formalA) which designates the formal type, and the type of + -- the component is this access type. Finally the Entry_Component of + -- each formal is set to reference the corresponding record component. + + procedure Expand_N_Entry_Declaration (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Entry_Ent : constant Entity_Id := Defining_Identifier (N); + Components : List_Id; + Formal : Node_Id; + Ftype : Entity_Id; + Last_Decl : Node_Id; + Component : Entity_Id; + Ctype : Entity_Id; + Decl : Node_Id; + Rec_Ent : Entity_Id; + Acc_Ent : Entity_Id; + + begin + Formal := First_Formal (Entry_Ent); + Last_Decl := N; + + -- Most processing is done only if parameters are present + + if Present (Formal) then + Components := New_List; + + -- Loop through formals + + while Present (Formal) loop + Set_Is_Entry_Formal (Formal); + Component := + Make_Defining_Identifier (Sloc (Formal), Chars (Formal)); + Set_Entry_Component (Formal, Component); + Set_Entry_Formal (Component, Formal); + Ftype := Etype (Formal); + + -- Declare new access type and then append + + Ctype := + Make_Defining_Identifier (Loc, New_Internal_Name ('A')); + + Decl := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => Ctype, + Type_Definition => + Make_Access_To_Object_Definition (Loc, + All_Present => True, + Constant_Present => Ekind (Formal) = E_In_Parameter, + Subtype_Indication => New_Reference_To (Ftype, Loc))); + + Insert_After (Last_Decl, Decl); + Last_Decl := Decl; + + Append_To (Components, + Make_Component_Declaration (Loc, + Defining_Identifier => Component, + Subtype_Indication => New_Reference_To (Ctype, Loc))); + + Next_Formal_With_Extras (Formal); + end loop; + + -- Create the Entry_Parameter_Record declaration + + Rec_Ent := + Make_Defining_Identifier (Loc, New_Internal_Name ('P')); + + Decl := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => Rec_Ent, + Type_Definition => + Make_Record_Definition (Loc, + Component_List => + Make_Component_List (Loc, + Component_Items => Components))); + + Insert_After (Last_Decl, Decl); + Last_Decl := Decl; + + -- Construct and link in the corresponding access type + + Acc_Ent := + Make_Defining_Identifier (Loc, New_Internal_Name ('A')); + + Set_Entry_Parameters_Type (Entry_Ent, Acc_Ent); + + Decl := + Make_Full_Type_Declaration (Loc, + Defining_Identifier => Acc_Ent, + Type_Definition => + Make_Access_To_Object_Definition (Loc, + All_Present => True, + Subtype_Indication => New_Reference_To (Rec_Ent, Loc))); + + Insert_After (Last_Decl, Decl); + Last_Decl := Decl; + + end if; + + end Expand_N_Entry_Declaration; + + ----------------------------- + -- Expand_N_Protected_Body -- + ----------------------------- + + -- Protected bodies are expanded to the completion of the subprograms + -- created for the corresponding protected type. These are a protected + -- and unprotected version of each protected subprogram in the object, + -- a function to calculate each entry barrier, and a procedure to + -- execute the sequence of statements of each protected entry body. + -- For example, for protected type ptype: + + -- function entB + -- (O : System.Address; + -- E : Protected_Entry_Index) + -- return Boolean + -- is + -- <discriminant renamings> + -- <private object renamings> + -- begin + -- return <barrier expression>; + -- end entB; + + -- procedure pprocN (_object : in out poV;...) is + -- <discriminant renamings> + -- <private object renamings> + -- begin + -- <sequence of statements> + -- end pprocN; + + -- procedure pproc (_object : in out poV;...) is + -- procedure _clean is + -- Pn : Boolean; + -- begin + -- ptypeS (_object, Pn); + -- Unlock (_object._object'Access); + -- Abort_Undefer.all; + -- end _clean; + -- begin + -- Abort_Defer.all; + -- Lock (_object._object'Access); + -- pprocN (_object;...); + -- at end + -- _clean; + -- end pproc; + + -- function pfuncN (_object : poV;...) return Return_Type is + -- <discriminant renamings> + -- <private object renamings> + -- begin + -- <sequence of statements> + -- end pfuncN; + + -- function pfunc (_object : poV) return Return_Type is + -- procedure _clean is + -- begin + -- Unlock (_object._object'Access); + -- Abort_Undefer.all; + -- end _clean; + -- begin + -- Abort_Defer.all; + -- Lock (_object._object'Access); + -- return pfuncN (_object); + -- at end + -- _clean; + -- end pfunc; + + -- procedure entE + -- (O : System.Address; + -- P : System.Address; + -- E : Protected_Entry_Index) + -- is + -- <discriminant renamings> + -- <private object renamings> + -- type poVP is access poV; + -- _Object : ptVP := ptVP!(O); + -- begin + -- begin + -- <statement sequence> + -- Complete_Entry_Body (_Object._Object); + -- exception + -- when all others => + -- Exceptional_Complete_Entry_Body ( + -- _Object._Object, Get_GNAT_Exception); + -- end; + -- end entE; + + -- The type poV is the record created for the protected type to hold + -- the state of the protected object. + + procedure Expand_N_Protected_Body (N : Node_Id) is + Pid : constant Entity_Id := Corresponding_Spec (N); + Has_Entries : Boolean := False; + Op_Decl : Node_Id; + Op_Body : Node_Id; + Op_Id : Entity_Id; + New_Op_Body : Node_Id; + Current_Node : Node_Id; + Num_Entries : Natural := 0; + + begin + if Nkind (Parent (N)) = N_Subunit then + + -- This is the proper body corresponding to a stub. The declarations + -- must be inserted at the point of the stub, which is in the decla- + -- rative part of the parent unit. + + Current_Node := Corresponding_Stub (Parent (N)); + + else + Current_Node := N; + end if; + + Op_Body := First (Declarations (N)); + + -- The protected body is replaced with the bodies of its + -- protected operations, and the declarations for internal objects + -- that may have been created for entry family bounds. + + Rewrite (N, Make_Null_Statement (Sloc (N))); + Analyze (N); + + while Present (Op_Body) loop + + case Nkind (Op_Body) is + when N_Subprogram_Declaration => + null; + + when N_Subprogram_Body => + + -- Exclude funtions created to analyze defaults. + + if not Is_Eliminated (Defining_Entity (Op_Body)) then + New_Op_Body := + Build_Unprotected_Subprogram_Body (Op_Body, Pid); + + Insert_After (Current_Node, New_Op_Body); + Current_Node := New_Op_Body; + Analyze (New_Op_Body); + + Update_Prival_Subtypes (New_Op_Body); + + -- Build the corresponding protected operation only if + -- this is a visible operation of the type, or if it is + -- an interrupt handler. Otherwise it is only callable + -- from within the object, and the unprotected version + -- is sufficient. + + if Present (Corresponding_Spec (Op_Body)) then + Op_Decl := + Unit_Declaration_Node (Corresponding_Spec (Op_Body)); + + if Nkind (Parent (Op_Decl)) = N_Protected_Definition + and then + (List_Containing (Op_Decl) = + Visible_Declarations (Parent (Op_Decl)) + or else + Is_Interrupt_Handler + (Corresponding_Spec (Op_Body))) + then + New_Op_Body := + Build_Protected_Subprogram_Body ( + Op_Body, Pid, Specification (New_Op_Body)); + + Insert_After (Current_Node, New_Op_Body); + Analyze (New_Op_Body); + end if; + end if; + end if; + + when N_Entry_Body => + Op_Id := Defining_Identifier (Op_Body); + Has_Entries := True; + Num_Entries := Num_Entries + 1; + + New_Op_Body := Build_Protected_Entry (Op_Body, Op_Id, Pid); + + Insert_After (Current_Node, New_Op_Body); + Current_Node := New_Op_Body; + Analyze (New_Op_Body); + + Update_Prival_Subtypes (New_Op_Body); + + when N_Implicit_Label_Declaration => + null; + + when N_Itype_Reference => + Insert_After (Current_Node, New_Copy (Op_Body)); + + when N_Freeze_Entity => + New_Op_Body := New_Copy (Op_Body); + + if Present (Entity (Op_Body)) + and then Freeze_Node (Entity (Op_Body)) = Op_Body + then + Set_Freeze_Node (Entity (Op_Body), New_Op_Body); + end if; + + Insert_After (Current_Node, New_Op_Body); + Current_Node := New_Op_Body; + Analyze (New_Op_Body); + + when N_Pragma => + New_Op_Body := New_Copy (Op_Body); + Insert_After (Current_Node, New_Op_Body); + Current_Node := New_Op_Body; + Analyze (New_Op_Body); + + when N_Object_Declaration => + pragma Assert (not Comes_From_Source (Op_Body)); + New_Op_Body := New_Copy (Op_Body); + Insert_After (Current_Node, New_Op_Body); + Current_Node := New_Op_Body; + Analyze (New_Op_Body); + + when others => + raise Program_Error; + + end case; + + Next (Op_Body); + end loop; + + -- Finally, create the body of the funtion that maps an entry index + -- into the corresponding body index, except when there is no entry, + -- or in a ravenscar-like profile (no abort, no entry queue, 1 entry) + + if Has_Entries + and then (Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Num_Entries > 1) + then + New_Op_Body := Build_Find_Body_Index (Pid); + Insert_After (Current_Node, New_Op_Body); + Analyze (New_Op_Body); + end if; + end Expand_N_Protected_Body; + + ----------------------------------------- + -- Expand_N_Protected_Type_Declaration -- + ----------------------------------------- + + -- First we create a corresponding record type declaration used to + -- represent values of this protected type. + -- The general form of this type declaration is + + -- type poV (discriminants) is record + -- _Object : aliased <kind>Protection + -- [(<entry count> [, <handler count>])]; + -- [entry_family : array (bounds) of Void;] + -- <private data fields> + -- end record; + + -- The discriminants are present only if the corresponding protected + -- type has discriminants, and they exactly mirror the protected type + -- discriminants. The private data fields similarly mirror the + -- private declarations of the protected type. + + -- The Object field is always present. It contains RTS specific data + -- used to control the protected object. It is declared as Aliased + -- so that it can be passed as a pointer to the RTS. This allows the + -- protected record to be referenced within RTS data structures. + -- An appropriate Protection type and discriminant are generated. + + -- The Service field is present for protected objects with entries. It + -- contains sufficient information to allow the entry service procedure + -- for this object to be called when the object is not known till runtime. + + -- One entry_family component is present for each entry family in the + -- task definition (see Expand_N_Task_Type_Declaration). + + -- When a protected object is declared, an instance of the protected type + -- value record is created. The elaboration of this declaration creates + -- the correct bounds for the entry families, and also evaluates the + -- priority expression if needed. The initialization routine for + -- the protected type itself then calls Initialize_Protection with + -- appropriate parameters to initialize the value of the Task_Id field. + -- Install_Handlers may be also called if a pragma Attach_Handler applies. + + -- Note: this record is passed to the subprograms created by the + -- expansion of protected subprograms and entries. It is an in parameter + -- to protected functions and an in out parameter to procedures and + -- entry bodies. The Entity_Id for this created record type is placed + -- in the Corresponding_Record_Type field of the associated protected + -- type entity. + + -- Next we create a procedure specifications for protected subprograms + -- and entry bodies. For each protected subprograms two subprograms are + -- created, an unprotected and a protected version. The unprotected + -- version is called from within other operations of the same protected + -- object. + + -- We also build the call to register the procedure if a pragma + -- Interrupt_Handler applies. + + -- A single subprogram is created to service all entry bodies; it has an + -- additional boolean out parameter indicating that the previous entry + -- call made by the current task was serviced immediately, i.e. not by + -- proxy. The O parameter contains a pointer to a record object of the + -- type described above. An untyped interface is used here to allow this + -- procedure to be called in places where the type of the object to be + -- serviced is not known. This must be done, for example, when a call + -- that may have been requeued is cancelled; the corresponding object + -- must be serviced, but which object that is not known till runtime. + + -- procedure ptypeS + -- (O : System.Address; P : out Boolean); + -- procedure pprocN (_object : in out poV); + -- procedure pproc (_object : in out poV); + -- function pfuncN (_object : poV); + -- function pfunc (_object : poV); + -- ... + + -- Note that this must come after the record type declaration, since + -- the specs refer to this type. + + procedure Expand_N_Protected_Type_Declaration (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Prottyp : constant Entity_Id := Defining_Identifier (N); + Protnm : constant Name_Id := Chars (Prottyp); + + Pdef : constant Node_Id := Protected_Definition (N); + -- This contains two lists; one for visible and one for private decls + + Rec_Decl : Node_Id; + Cdecls : List_Id; + Discr_Map : Elist_Id := New_Elmt_List; + Priv : Node_Id; + Pent : Entity_Id; + New_Priv : Node_Id; + Comp : Node_Id; + Comp_Id : Entity_Id; + Sub : Node_Id; + Current_Node : Node_Id := N; + Nam : Name_Id; + Bdef : Entity_Id := Empty; -- avoid uninit warning + Edef : Entity_Id := Empty; -- avoid uninit warning + Entries_Aggr : Node_Id; + Body_Id : Entity_Id; + Body_Arr : Node_Id; + E_Count : Int; + Object_Comp : Node_Id; + + procedure Register_Handler; + -- for a protected operation that is an interrupt handler, add the + -- freeze action that will register it as such. + + ---------------------- + -- Register_Handler -- + ---------------------- + + procedure Register_Handler is + + -- All semantic checks already done in Sem_Prag + + Prot_Proc : constant Entity_Id := + Defining_Unit_Name + (Specification (Current_Node)); + + Proc_Address : constant Node_Id := + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Prot_Proc, Loc), + Attribute_Name => Name_Address); + + RTS_Call : constant Entity_Id := + Make_Procedure_Call_Statement (Loc, + Name => + New_Reference_To ( + RTE (RE_Register_Interrupt_Handler), Loc), + Parameter_Associations => + New_List (Proc_Address)); + begin + Append_Freeze_Action (Prot_Proc, RTS_Call); + end Register_Handler; + + -- Start of processing for Expand_N_Protected_Type_Declaration + + begin + if Present (Corresponding_Record_Type (Prottyp)) then + return; + else + Rec_Decl := Build_Corresponding_Record (N, Prottyp, Loc); + Cdecls := Component_Items + (Component_List (Type_Definition (Rec_Decl))); + end if; + + Qualify_Entity_Names (N); + + -- If the type has discriminants, their occurrences in the declaration + -- have been replaced by the corresponding discriminals. For components + -- that are constrained by discriminants, their homologues in the + -- corresponding record type must refer to the discriminants of that + -- record, so we must apply a new renaming to subtypes_indications: + + -- protected discriminant => discriminal => record discriminant. + -- This replacement is not applied to default expressions, for which + -- the discriminal is correct. + + if Has_Discriminants (Prottyp) then + declare + Disc : Entity_Id; + Decl : Node_Id; + + begin + Disc := First_Discriminant (Prottyp); + Decl := First (Discriminant_Specifications (Rec_Decl)); + + while Present (Disc) loop + Append_Elmt (Discriminal (Disc), Discr_Map); + Append_Elmt (Defining_Identifier (Decl), Discr_Map); + Next_Discriminant (Disc); + Next (Decl); + end loop; + end; + end if; + + -- Fill in the component declarations. + + -- Add components for entry families. For each entry family, + -- create an anonymous type declaration with the same size, and + -- analyze the type. + + Collect_Entry_Families (Loc, Cdecls, Current_Node, Prottyp); + + -- Prepend the _Object field with the right type to the component + -- list. We need to compute the number of entries, and in some cases + -- the number of Attach_Handler pragmas. + + declare + Ritem : Node_Id; + Num_Attach_Handler : Int := 0; + Protection_Subtype : Node_Id; + Entry_Count_Expr : constant Node_Id := + Build_Entry_Count_Expression + (Prottyp, Cdecls, Loc); + + begin + if Has_Attach_Handler (Prottyp) then + Ritem := First_Rep_Item (Prottyp); + while Present (Ritem) loop + if Nkind (Ritem) = N_Pragma + and then Chars (Ritem) = Name_Attach_Handler + then + Num_Attach_Handler := Num_Attach_Handler + 1; + end if; + + Next_Rep_Item (Ritem); + end loop; + + if Restricted_Profile then + Protection_Subtype := + New_Reference_To (RTE (RE_Protection_Entry), Loc); + + else + Protection_Subtype := + Make_Subtype_Indication + (Sloc => Loc, + Subtype_Mark => + New_Reference_To + (RTE (RE_Static_Interrupt_Protection), Loc), + Constraint => + Make_Index_Or_Discriminant_Constraint ( + Sloc => Loc, + Constraints => New_List ( + Entry_Count_Expr, + Make_Integer_Literal (Loc, Num_Attach_Handler)))); + end if; + + elsif Has_Interrupt_Handler (Prottyp) then + Protection_Subtype := + Make_Subtype_Indication ( + Sloc => Loc, + Subtype_Mark => New_Reference_To + (RTE (RE_Dynamic_Interrupt_Protection), Loc), + Constraint => + Make_Index_Or_Discriminant_Constraint ( + Sloc => Loc, + Constraints => New_List (Entry_Count_Expr))); + + elsif Has_Entries (Prottyp) then + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Number_Entries (Prottyp) > 1 + then + Protection_Subtype := + Make_Subtype_Indication ( + Sloc => Loc, + Subtype_Mark => + New_Reference_To (RTE (RE_Protection_Entries), Loc), + Constraint => + Make_Index_Or_Discriminant_Constraint ( + Sloc => Loc, + Constraints => New_List (Entry_Count_Expr))); + + else + Protection_Subtype := + New_Reference_To (RTE (RE_Protection_Entry), Loc); + end if; + + else + Protection_Subtype := New_Reference_To (RTE (RE_Protection), Loc); + end if; + + Object_Comp := + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uObject), + Aliased_Present => True, + Subtype_Indication => Protection_Subtype); + end; + + pragma Assert (Present (Pdef)); + + -- Add private field components. + + if Present (Private_Declarations (Pdef)) then + Priv := First (Private_Declarations (Pdef)); + + while Present (Priv) loop + + if Nkind (Priv) = N_Component_Declaration then + Pent := Defining_Identifier (Priv); + New_Priv := + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Sloc (Pent), Chars (Pent)), + Subtype_Indication => + New_Copy_Tree (Subtype_Indication (Priv), Discr_Map), + Expression => Expression (Priv)); + + Append_To (Cdecls, New_Priv); + + elsif Nkind (Priv) = N_Subprogram_Declaration then + + -- Make the unprotected version of the subprogram available + -- for expansion of intra object calls. There is need for + -- a protected version only if the subprogram is an interrupt + -- handler, otherwise this operation can only be called from + -- within the body. + + Sub := + Make_Subprogram_Declaration (Loc, + Specification => + Build_Protected_Sub_Specification + (Priv, Prottyp, Unprotected => True)); + + Insert_After (Current_Node, Sub); + Analyze (Sub); + + Set_Protected_Body_Subprogram + (Defining_Unit_Name (Specification (Priv)), + Defining_Unit_Name (Specification (Sub))); + + Current_Node := Sub; + if Is_Interrupt_Handler + (Defining_Unit_Name (Specification (Priv))) + then + Sub := + Make_Subprogram_Declaration (Loc, + Specification => + Build_Protected_Sub_Specification + (Priv, Prottyp, Unprotected => False)); + + Insert_After (Current_Node, Sub); + Analyze (Sub); + Current_Node := Sub; + + if not Restricted_Profile then + Register_Handler; + end if; + end if; + end if; + + Next (Priv); + end loop; + end if; + + -- Put the _Object component after the private component so that it + -- be finalized early as required by 9.4 (20) + + Append_To (Cdecls, Object_Comp); + + Insert_After (Current_Node, Rec_Decl); + Current_Node := Rec_Decl; + + -- Analyze the record declaration immediately after construction, + -- because the initialization procedure is needed for single object + -- declarations before the next entity is analyzed (the freeze call + -- that generates this initialization procedure is found below). + + Analyze (Rec_Decl, Suppress => All_Checks); + + -- Collect pointers to entry bodies and their barriers, to be placed + -- in the Entry_Bodies_Array for the type. For each entry/family we + -- add an expression to the aggregate which is the initial value of + -- this array. The array is declared after all protected subprograms. + + if Has_Entries (Prottyp) then + Entries_Aggr := + Make_Aggregate (Loc, Expressions => New_List); + + else + Entries_Aggr := Empty; + end if; + + -- Build two new procedure specifications for each protected + -- subprogram; one to call from outside the object and one to + -- call from inside. Build a barrier function and an entry + -- body action procedure specification for each protected entry. + -- Initialize the entry body array. + + E_Count := 0; + + Comp := First (Visible_Declarations (Pdef)); + + while Present (Comp) loop + if Nkind (Comp) = N_Subprogram_Declaration then + Sub := + Make_Subprogram_Declaration (Loc, + Specification => + Build_Protected_Sub_Specification + (Comp, Prottyp, Unprotected => True)); + + Insert_After (Current_Node, Sub); + Analyze (Sub); + + Set_Protected_Body_Subprogram + (Defining_Unit_Name (Specification (Comp)), + Defining_Unit_Name (Specification (Sub))); + + -- Make the protected version of the subprogram available + -- for expansion of external calls. + + Current_Node := Sub; + + Sub := + Make_Subprogram_Declaration (Loc, + Specification => + Build_Protected_Sub_Specification + (Comp, Prottyp, Unprotected => False)); + + Insert_After (Current_Node, Sub); + Analyze (Sub); + Current_Node := Sub; + + -- If a pragma Interrupt_Handler applies, build and add + -- a call to Register_Interrupt_Handler to the freezing actions + -- of the protected version (Current_Node) of the subprogram: + -- system.interrupts.register_interrupt_handler + -- (prot_procP'address); + + if not Restricted_Profile + and then Is_Interrupt_Handler + (Defining_Unit_Name (Specification (Comp))) + then + Register_Handler; + end if; + + elsif Nkind (Comp) = N_Entry_Declaration then + E_Count := E_Count + 1; + Comp_Id := Defining_Identifier (Comp); + Set_Privals_Chain (Comp_Id, New_Elmt_List); + Nam := Chars (Comp_Id); + Edef := + Make_Defining_Identifier (Loc, + Build_Selected_Name (Protnm, New_Internal_Name ('E'))); + Sub := + Make_Subprogram_Declaration (Loc, + Specification => + Build_Protected_Entry_Specification (Edef, Comp_Id, Loc)); + + Insert_After (Current_Node, Sub); + Analyze (Sub); + + Set_Protected_Body_Subprogram ( + Defining_Identifier (Comp), + Defining_Unit_Name (Specification (Sub))); + + Current_Node := Sub; + + Bdef := + Make_Defining_Identifier (Loc, + Build_Selected_Name (Protnm, New_Internal_Name ('B'))); + Sub := + Make_Subprogram_Declaration (Loc, + Specification => + Build_Barrier_Function_Specification (Bdef, Loc)); + + Insert_After (Current_Node, Sub); + Analyze (Sub); + Set_Protected_Body_Subprogram (Bdef, Bdef); + Set_Barrier_Function (Comp_Id, Bdef); + Set_Scope (Bdef, Scope (Comp_Id)); + Current_Node := Sub; + + -- Collect pointers to the protected subprogram and the barrier + -- of the current entry, for insertion into Entry_Bodies_Array. + + Append ( + Make_Aggregate (Loc, + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Bdef, Loc), + Attribute_Name => Name_Unrestricted_Access), + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Edef, Loc), + Attribute_Name => Name_Unrestricted_Access))), + Expressions (Entries_Aggr)); + + end if; + + Next (Comp); + end loop; + + -- If there are some private entry declarations, expand it as if they + -- were visible entries. + + if Present (Private_Declarations (Pdef)) then + Comp := First (Private_Declarations (Pdef)); + + while Present (Comp) loop + if Nkind (Comp) = N_Entry_Declaration then + E_Count := E_Count + 1; + Comp_Id := Defining_Identifier (Comp); + Set_Privals_Chain (Comp_Id, New_Elmt_List); + Nam := Chars (Comp_Id); + Edef := + Make_Defining_Identifier (Loc, + Build_Selected_Name (Protnm, New_Internal_Name ('E'))); + + Sub := + Make_Subprogram_Declaration (Loc, + Specification => + Build_Protected_Entry_Specification (Edef, Comp_Id, Loc)); + + Insert_After (Current_Node, Sub); + Analyze (Sub); + + Set_Protected_Body_Subprogram ( + Defining_Identifier (Comp), + Defining_Unit_Name (Specification (Sub))); + + Current_Node := Sub; + + Bdef := + Make_Defining_Identifier (Loc, + Build_Selected_Name (Protnm, New_Internal_Name ('B'))); + Sub := + Make_Subprogram_Declaration (Loc, + Specification => + Build_Barrier_Function_Specification (Bdef, Loc)); + + Insert_After (Current_Node, Sub); + Analyze (Sub); + Set_Protected_Body_Subprogram (Bdef, Bdef); + Set_Barrier_Function (Comp_Id, Bdef); + Set_Scope (Bdef, Scope (Comp_Id)); + Current_Node := Sub; + + -- Collect pointers to the protected subprogram and the + -- barrier of the current entry, for insertion into + -- Entry_Bodies_Array. + + Append ( + Make_Aggregate (Loc, + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Bdef, Loc), + Attribute_Name => Name_Unrestricted_Access), + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Edef, Loc), + Attribute_Name => Name_Unrestricted_Access))), + Expressions (Entries_Aggr)); + end if; + + Next (Comp); + end loop; + end if; + + -- Emit declaration for Entry_Bodies_Array, now that the addresses of + -- all protected subprograms have been collected. + + if Has_Entries (Prottyp) then + Body_Id := Make_Defining_Identifier (Sloc (Prottyp), + New_External_Name (Chars (Prottyp), 'A')); + + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else E_Count > 1 + then + Body_Arr := Make_Object_Declaration (Loc, + Defining_Identifier => Body_Id, + Aliased_Present => True, + Object_Definition => + Make_Subtype_Indication (Loc, + Subtype_Mark => New_Reference_To ( + RTE (RE_Protected_Entry_Body_Array), Loc), + Constraint => + Make_Index_Or_Discriminant_Constraint (Loc, + Constraints => New_List ( + Make_Range (Loc, + Make_Integer_Literal (Loc, 1), + Make_Integer_Literal (Loc, E_Count))))), + Expression => Entries_Aggr); + + else + Body_Arr := Make_Object_Declaration (Loc, + Defining_Identifier => Body_Id, + Aliased_Present => True, + Object_Definition => New_Reference_To (RTE (RE_Entry_Body), Loc), + Expression => + Make_Aggregate (Loc, + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Bdef, Loc), + Attribute_Name => Name_Unrestricted_Access), + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Edef, Loc), + Attribute_Name => Name_Unrestricted_Access)))); + end if; + + -- A pointer to this array will be placed in the corresponding + -- record by its initialization procedure, so this needs to be + -- analyzed here. + + Insert_After (Current_Node, Body_Arr); + Current_Node := Body_Arr; + Analyze (Body_Arr); + + Set_Entry_Bodies_Array (Prottyp, Body_Id); + + -- Finally, build the function that maps an entry index into the + -- corresponding body. A pointer to this function is placed in each + -- object of the type. Except for a ravenscar-like profile (no abort, + -- no entry queue, 1 entry) + + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else E_Count > 1 + then + Sub := + Make_Subprogram_Declaration (Loc, + Specification => Build_Find_Body_Index_Spec (Prottyp)); + Insert_After (Current_Node, Sub); + Analyze (Sub); + end if; + end if; + end Expand_N_Protected_Type_Declaration; + + -------------------------------- + -- Expand_N_Requeue_Statement -- + -------------------------------- + + -- A requeue statement is expanded into one of four GNARLI operations, + -- depending on the source and destination (task or protected object). + -- In addition, code must be generated to jump around the remainder of + -- processing for the original entry and, if the destination is a + -- (different) protected object, to attempt to service it. + -- The following illustrates the various cases: + + -- procedure entE + -- (O : System.Address; + -- P : System.Address; + -- E : Protected_Entry_Index) + -- is + -- <discriminant renamings> + -- <private object renamings> + -- type poVP is access poV; + -- _Object : ptVP := ptVP!(O); + -- + -- begin + -- begin + -- <start of statement sequence for entry> + -- + -- -- Requeue from one protected entry body to another protected + -- -- entry. + -- + -- Requeue_Protected_Entry ( + -- _object._object'Access, + -- new._object'Access, + -- E, + -- Abort_Present); + -- return; + -- + -- <some more of the statement sequence for entry> + -- + -- -- Requeue from an entry body to a task entry. + -- + -- Requeue_Protected_To_Task_Entry ( + -- New._task_id, + -- E, + -- Abort_Present); + -- return; + -- + -- <rest of statement sequence for entry> + -- Complete_Entry_Body (_Object._Object); + -- + -- exception + -- when all others => + -- Exceptional_Complete_Entry_Body ( + -- _Object._Object, Get_GNAT_Exception); + -- end; + -- end entE; + + -- Requeue of a task entry call to a task entry. + -- + -- Accept_Call (E, Ann); + -- <start of statement sequence for accept statement> + -- Requeue_Task_Entry (New._task_id, E, Abort_Present); + -- goto Lnn; + -- <rest of statement sequence for accept statement> + -- <<Lnn>> + -- Complete_Rendezvous; + -- exception + -- when all others => + -- Exceptional_Complete_Rendezvous (Get_GNAT_Exception); + + -- Requeue of a task entry call to a protected entry. + -- + -- Accept_Call (E, Ann); + -- <start of statement sequence for accept statement> + -- Requeue_Task_To_Protected_Entry ( + -- new._object'Access, + -- E, + -- Abort_Present); + -- newS (new, Pnn); + -- goto Lnn; + -- <rest of statement sequence for accept statement> + -- <<Lnn>> + -- Complete_Rendezvous; + -- exception + -- when all others => + -- Exceptional_Complete_Rendezvous (Get_GNAT_Exception); + + -- Further details on these expansions can be found in + -- Expand_N_Protected_Body and Expand_N_Accept_Statement. + + procedure Expand_N_Requeue_Statement (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Acc_Stat : Node_Id; + Concval : Node_Id; + Ename : Node_Id; + Index : Node_Id; + Conctyp : Entity_Id; + Oldtyp : Entity_Id; + Lab_Node : Node_Id; + Rcall : Node_Id; + Abortable : Node_Id; + Skip_Stat : Node_Id; + Self_Param : Node_Id; + New_Param : Node_Id; + Params : List_Id; + RTS_Call : Entity_Id; + + begin + if Abort_Present (N) then + Abortable := New_Occurrence_Of (Standard_True, Loc); + else + Abortable := New_Occurrence_Of (Standard_False, Loc); + end if; + + -- Set up the target object. + + Extract_Entry (N, Concval, Ename, Index); + Conctyp := Etype (Concval); + New_Param := Concurrent_Ref (Concval); + + -- The target entry index and abortable flag are the same for all cases. + + Params := New_List ( + Entry_Index_Expression (Loc, Entity (Ename), Index, Conctyp), + Abortable); + + -- Determine proper GNARLI call and required additional parameters + -- Loop to find nearest enclosing task type or protected type + + Oldtyp := Current_Scope; + loop + if Is_Task_Type (Oldtyp) then + if Is_Task_Type (Conctyp) then + RTS_Call := RTE (RE_Requeue_Task_Entry); + + else + pragma Assert (Is_Protected_Type (Conctyp)); + RTS_Call := RTE (RE_Requeue_Task_To_Protected_Entry); + New_Param := + Make_Attribute_Reference (Loc, + Prefix => New_Param, + Attribute_Name => Name_Unchecked_Access); + end if; + + Prepend (New_Param, Params); + exit; + + elsif Is_Protected_Type (Oldtyp) then + Self_Param := + Make_Attribute_Reference (Loc, + Prefix => Concurrent_Ref (New_Occurrence_Of (Oldtyp, Loc)), + Attribute_Name => Name_Unchecked_Access); + + if Is_Task_Type (Conctyp) then + RTS_Call := RTE (RE_Requeue_Protected_To_Task_Entry); + + else + pragma Assert (Is_Protected_Type (Conctyp)); + RTS_Call := RTE (RE_Requeue_Protected_Entry); + New_Param := + Make_Attribute_Reference (Loc, + Prefix => New_Param, + Attribute_Name => Name_Unchecked_Access); + end if; + + Prepend (New_Param, Params); + Prepend (Self_Param, Params); + exit; + + -- If neither task type or protected type, must be in some + -- inner enclosing block, so move on out + + else + Oldtyp := Scope (Oldtyp); + end if; + end loop; + + -- Create the GNARLI call. + + Rcall := Make_Procedure_Call_Statement (Loc, + Name => + New_Occurrence_Of (RTS_Call, Loc), + Parameter_Associations => Params); + + Rewrite (N, Rcall); + Analyze (N); + + if Is_Protected_Type (Oldtyp) then + + -- Build the return statement to skip the rest of the entry body + + Skip_Stat := Make_Return_Statement (Loc); + + else + -- If the requeue is within a task, find the end label of the + -- enclosing accept statement. + + Acc_Stat := Parent (N); + while Nkind (Acc_Stat) /= N_Accept_Statement loop + Acc_Stat := Parent (Acc_Stat); + end loop; + + -- The last statement is the second label, used for completing the + -- rendezvous the usual way. + -- The label we are looking for is right before it. + + Lab_Node := + Prev (Last (Statements (Handled_Statement_Sequence (Acc_Stat)))); + + pragma Assert (Nkind (Lab_Node) = N_Label); + + -- Build the goto statement to skip the rest of the accept + -- statement. + + Skip_Stat := + Make_Goto_Statement (Loc, + Name => New_Occurrence_Of (Entity (Identifier (Lab_Node)), Loc)); + end if; + + Set_Analyzed (Skip_Stat); + + Insert_After (N, Skip_Stat); + + end Expand_N_Requeue_Statement; + + ------------------------------- + -- Expand_N_Selective_Accept -- + ------------------------------- + + procedure Expand_N_Selective_Accept (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Alts : constant List_Id := Select_Alternatives (N); + + Accept_Case : List_Id; + Accept_List : List_Id := New_List; + + Alt : Node_Id; + Alt_List : List_Id := New_List; + Alt_Stats : List_Id; + Ann : Entity_Id := Empty; + + Block : Node_Id; + Check_Guard : Boolean := True; + Decls : List_Id := New_List; + Stats : List_Id := New_List; + + Body_List : List_Id := New_List; + Trailing_List : List_Id := New_List; + + Choices : List_Id; + Else_Present : Boolean := False; + Terminate_Alt : Node_Id := Empty; + Select_Mode : Node_Id; + + Delay_Case : List_Id; + Delay_Count : Integer := 0; + Delay_Val : Entity_Id; + Delay_Index : Entity_Id; + Delay_Min : Entity_Id; + Delay_Num : Int := 1; + Delay_Alt_List : List_Id := New_List; + Delay_List : List_Id := New_List; + D : Entity_Id; + M : Entity_Id; + + First_Delay : Boolean := True; + Guard_Open : Entity_Id; + + End_Lab : Node_Id; + Index : Int := 1; + Lab : Node_Id; + Num_Alts : Int; + Num_Accept : Nat := 0; + Proc : Node_Id; + Q : Node_Id; + Time_Type : Entity_Id; + X : Node_Id; + Select_Call : Node_Id; + + Qnam : constant Entity_Id := + Make_Defining_Identifier (Loc, New_External_Name ('S', 0)); + + Xnam : constant Entity_Id := + Make_Defining_Identifier (Loc, New_External_Name ('J', 1)); + + ----------------------- + -- Local subprograms -- + ----------------------- + + function Accept_Or_Raise return List_Id; + -- For the rare case where delay alternatives all have guards, and + -- all of them are closed, it is still possible that there were open + -- accept alternatives with no callers. We must reexamine the + -- Accept_List, and execute a selective wait with no else if some + -- accept is open. If none, we raise program_error. + + procedure Add_Accept (Alt : Node_Id); + -- Process a single accept statement in a select alternative. Build + -- procedure for body of accept, and add entry to dispatch table with + -- expression for guard, in preparation for call to run time select. + + function Make_And_Declare_Label (Num : Int) return Node_Id; + -- Manufacture a label using Num as a serial number and declare it. + -- The declaration is appended to Decls. The label marks the trailing + -- statements of an accept or delay alternative. + + function Make_Select_Call (Select_Mode : Entity_Id) return Node_Id; + -- Build call to Selective_Wait runtime routine. + + procedure Process_Delay_Alternative (Alt : Node_Id; Index : Int); + -- Add code to compare value of delay with previous values, and + -- generate case entry for trailing statements. + + procedure Process_Accept_Alternative + (Alt : Node_Id; + Index : Int; + Proc : Node_Id); + -- Add code to call corresponding procedure, and branch to + -- trailing statements, if any. + + --------------------- + -- Accept_Or_Raise -- + --------------------- + + function Accept_Or_Raise return List_Id is + Cond : Node_Id; + Stats : List_Id; + J : constant Entity_Id := Make_Defining_Identifier (Loc, + New_Internal_Name ('J')); + + begin + -- We generate the following: + + -- for J in q'range loop + -- if q(J).S /=null_task_entry then + -- selective_wait (simple_mode,...); + -- done := True; + -- exit; + -- end if; + -- end loop; + -- + -- if no rendez_vous then + -- raise program_error; + -- end if; + + -- Note that the code needs to know that the selector name + -- in an Accept_Alternative is named S. + + Cond := Make_Op_Ne (Loc, + Left_Opnd => + Make_Selected_Component (Loc, + Prefix => Make_Indexed_Component (Loc, + Prefix => New_Reference_To (Qnam, Loc), + Expressions => New_List (New_Reference_To (J, Loc))), + Selector_Name => Make_Identifier (Loc, Name_S)), + Right_Opnd => + New_Reference_To (RTE (RE_Null_Task_Entry), Loc)); + + Stats := New_List ( + Make_Implicit_Loop_Statement (N, + Identifier => Empty, + Iteration_Scheme => + Make_Iteration_Scheme (Loc, + Loop_Parameter_Specification => + Make_Loop_Parameter_Specification (Loc, + Defining_Identifier => J, + Discrete_Subtype_Definition => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Qnam, Loc), + Attribute_Name => Name_Range, + Expressions => New_List ( + Make_Integer_Literal (Loc, 1))))), + + Statements => New_List ( + Make_Implicit_If_Statement (N, + Condition => Cond, + Then_Statements => New_List ( + Make_Select_Call ( + New_Reference_To (RTE (RE_Simple_Mode), Loc)), + Make_Exit_Statement (Loc)))))); + + Append_To (Stats, + Make_Raise_Program_Error (Loc, + Condition => Make_Op_Eq (Loc, + Left_Opnd => New_Reference_To (Xnam, Loc), + Right_Opnd => + New_Reference_To (RTE (RE_No_Rendezvous), Loc)))); + + return Stats; + end Accept_Or_Raise; + + ---------------- + -- Add_Accept -- + ---------------- + + procedure Add_Accept (Alt : Node_Id) is + Acc_Stm : constant Node_Id := Accept_Statement (Alt); + Ename : constant Node_Id := Entry_Direct_Name (Acc_Stm); + Eent : constant Entity_Id := Entity (Ename); + Index : constant Node_Id := Entry_Index (Acc_Stm); + Null_Body : Node_Id; + Proc_Body : Node_Id; + PB_Ent : Entity_Id; + Expr : Node_Id; + Call : Node_Id; + + begin + if No (Ann) then + Ann := Node (Last_Elmt (Accept_Address (Eent))); + end if; + + if Present (Condition (Alt)) then + Expr := + Make_Conditional_Expression (Loc, New_List ( + Condition (Alt), + Entry_Index_Expression (Loc, Eent, Index, Scope (Eent)), + New_Reference_To (RTE (RE_Null_Task_Entry), Loc))); + else + Expr := + Entry_Index_Expression + (Loc, Eent, Index, Scope (Eent)); + end if; + + if Present (Handled_Statement_Sequence (Accept_Statement (Alt))) then + Null_Body := New_Reference_To (Standard_False, Loc); + + if Abort_Allowed then + Call := Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Abort_Undefer), Loc)); + Insert_Before (First (Statements (Handled_Statement_Sequence ( + Accept_Statement (Alt)))), Call); + Analyze (Call); + end if; + + PB_Ent := + Make_Defining_Identifier (Sloc (Ename), + New_External_Name (Chars (Ename), 'A', Num_Accept)); + + Proc_Body := + Make_Subprogram_Body (Loc, + Specification => + Make_Procedure_Specification (Loc, + Defining_Unit_Name => PB_Ent), + Declarations => Declarations (Acc_Stm), + Handled_Statement_Sequence => + Build_Accept_Body (Accept_Statement (Alt))); + + -- During the analysis of the body of the accept statement, any + -- zero cost exception handler records were collected in the + -- Accept_Handler_Records field of the N_Accept_Alternative + -- node. This is where we move them to where they belong, + -- namely the newly created procedure. + + Set_Handler_Records (PB_Ent, Accept_Handler_Records (Alt)); + Append (Proc_Body, Body_List); + + else + Null_Body := New_Reference_To (Standard_True, Loc); + + -- if accept statement has declarations, insert above, given + -- that we are not creating a body for the accept. + + if Present (Declarations (Acc_Stm)) then + Insert_Actions (N, Declarations (Acc_Stm)); + end if; + end if; + + Append_To (Accept_List, + Make_Aggregate (Loc, Expressions => New_List (Null_Body, Expr))); + + Num_Accept := Num_Accept + 1; + + end Add_Accept; + + ---------------------------- + -- Make_And_Declare_Label -- + ---------------------------- + + function Make_And_Declare_Label (Num : Int) return Node_Id is + Lab_Id : Node_Id; + + begin + Lab_Id := Make_Identifier (Loc, New_External_Name ('L', Num)); + Lab := + Make_Label (Loc, Lab_Id); + + Append_To (Decls, + Make_Implicit_Label_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Chars (Lab_Id)), + Label_Construct => Lab)); + + return Lab; + end Make_And_Declare_Label; + + ---------------------- + -- Make_Select_Call -- + ---------------------- + + function Make_Select_Call (Select_Mode : Entity_Id) return Node_Id is + Params : List_Id := New_List; + + begin + Append ( + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Qnam, Loc), + Attribute_Name => Name_Unchecked_Access), + Params); + Append (Select_Mode, Params); + Append (New_Reference_To (Ann, Loc), Params); + Append (New_Reference_To (Xnam, Loc), Params); + + return + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Selective_Wait), Loc), + Parameter_Associations => Params); + end Make_Select_Call; + + -------------------------------- + -- Process_Accept_Alternative -- + -------------------------------- + + procedure Process_Accept_Alternative + (Alt : Node_Id; + Index : Int; + Proc : Node_Id) + is + Choices : List_Id := No_List; + Alt_Stats : List_Id; + + begin + Adjust_Condition (Condition (Alt)); + Alt_Stats := No_List; + + if Present (Handled_Statement_Sequence (Accept_Statement (Alt))) then + Choices := New_List ( + Make_Integer_Literal (Loc, Index)); + + Alt_Stats := New_List ( + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To ( + Defining_Unit_Name (Specification (Proc)), Loc))); + end if; + + if Statements (Alt) /= Empty_List then + + if No (Alt_Stats) then + + -- Accept with no body, followed by trailing statements. + + Choices := New_List ( + Make_Integer_Literal (Loc, Index)); + + Alt_Stats := New_List; + end if; + + -- After the call, if any, branch to to trailing statements. + -- We create a label for each, as well as the corresponding + -- label declaration. + + Lab := Make_And_Declare_Label (Index); + Append_To (Alt_Stats, + Make_Goto_Statement (Loc, + Name => New_Copy (Identifier (Lab)))); + + Append (Lab, Trailing_List); + Append_List (Statements (Alt), Trailing_List); + Append_To (Trailing_List, + Make_Goto_Statement (Loc, + Name => New_Copy (Identifier (End_Lab)))); + end if; + + if Present (Alt_Stats) then + + -- Procedure call. and/or trailing statements + + Append_To (Alt_List, + Make_Case_Statement_Alternative (Loc, + Discrete_Choices => Choices, + Statements => Alt_Stats)); + end if; + end Process_Accept_Alternative; + + ------------------------------- + -- Process_Delay_Alternative -- + ------------------------------- + + procedure Process_Delay_Alternative (Alt : Node_Id; Index : Int) is + Choices : List_Id; + Cond : Node_Id; + Delay_Alt : List_Id; + + begin + -- Deal with C/Fortran boolean as delay condition + + Adjust_Condition (Condition (Alt)); + + -- Determine the smallest specified delay. + -- for each delay alternative generate: + + -- if guard-expression then + -- Delay_Val := delay-expression; + -- Guard_Open := True; + -- if Delay_Val < Delay_Min then + -- Delay_Min := Delay_Val; + -- Delay_Index := Index; + -- end if; + -- end if; + + -- The enclosing if-statement is omitted if there is no guard. + + if Delay_Count = 1 + or else First_Delay + then + First_Delay := False; + + Delay_Alt := New_List ( + Make_Assignment_Statement (Loc, + Name => New_Reference_To (Delay_Min, Loc), + Expression => Expression (Delay_Statement (Alt)))); + + if Delay_Count > 1 then + Append_To (Delay_Alt, + Make_Assignment_Statement (Loc, + Name => New_Reference_To (Delay_Index, Loc), + Expression => Make_Integer_Literal (Loc, Index))); + end if; + + else + Delay_Alt := New_List ( + Make_Assignment_Statement (Loc, + Name => New_Reference_To (Delay_Val, Loc), + Expression => Expression (Delay_Statement (Alt)))); + + if Time_Type = Standard_Duration then + Cond := + Make_Op_Lt (Loc, + Left_Opnd => New_Reference_To (Delay_Val, Loc), + Right_Opnd => New_Reference_To (Delay_Min, Loc)); + + else + -- The scope of the time type must define a comparison + -- operator. The scope itself may not be visible, so we + -- construct a node with entity information to insure that + -- semantic analysis can find the proper operator. + + Cond := + Make_Function_Call (Loc, + Name => Make_Selected_Component (Loc, + Prefix => New_Reference_To (Scope (Time_Type), Loc), + Selector_Name => + Make_Operator_Symbol (Loc, + Chars => Name_Op_Lt, + Strval => No_String)), + Parameter_Associations => + New_List ( + New_Reference_To (Delay_Val, Loc), + New_Reference_To (Delay_Min, Loc))); + + Set_Entity (Prefix (Name (Cond)), Scope (Time_Type)); + end if; + + Append_To (Delay_Alt, + Make_Implicit_If_Statement (N, + Condition => Cond, + Then_Statements => New_List ( + Make_Assignment_Statement (Loc, + Name => New_Reference_To (Delay_Min, Loc), + Expression => New_Reference_To (Delay_Val, Loc)), + + Make_Assignment_Statement (Loc, + Name => New_Reference_To (Delay_Index, Loc), + Expression => Make_Integer_Literal (Loc, Index))))); + end if; + + if Check_Guard then + Append_To (Delay_Alt, + Make_Assignment_Statement (Loc, + Name => New_Reference_To (Guard_Open, Loc), + Expression => New_Reference_To (Standard_True, Loc))); + end if; + + if Present (Condition (Alt)) then + Delay_Alt := New_List ( + Make_Implicit_If_Statement (N, + Condition => Condition (Alt), + Then_Statements => Delay_Alt)); + end if; + + Append_List (Delay_Alt, Delay_List); + + -- If the delay alternative has a statement part, add a + -- choice to the case statements for delays. + + if Present (Statements (Alt)) then + + if Delay_Count = 1 then + Append_List (Statements (Alt), Delay_Alt_List); + + else + Choices := New_List ( + Make_Integer_Literal (Loc, Index)); + + Append_To (Delay_Alt_List, + Make_Case_Statement_Alternative (Loc, + Discrete_Choices => Choices, + Statements => Statements (Alt))); + end if; + + elsif Delay_Count = 1 then + + -- If the single delay has no trailing statements, add a branch + -- to the exit label to the selective wait. + + Delay_Alt_List := New_List ( + Make_Goto_Statement (Loc, + Name => New_Copy (Identifier (End_Lab)))); + + end if; + end Process_Delay_Alternative; + + -- Start of processing for Expand_N_Selective_Accept + + begin + -- First insert some declarations before the select. The first is: + + -- Ann : Address + + -- This variable holds the parameters passed to the accept body. This + -- declaration has already been inserted by the time we get here by + -- a call to Expand_Accept_Declarations made from the semantics when + -- processing the first accept statement contained in the select. We + -- can find this entity as Accept_Address (E), where E is any of the + -- entries references by contained accept statements. + + -- The first step is to scan the list of Selective_Accept_Statements + -- to find this entity, and also count the number of accepts, and + -- determine if terminated, delay or else is present: + + Num_Alts := 0; + + Alt := First (Alts); + while Present (Alt) loop + + if Nkind (Alt) = N_Accept_Alternative then + Add_Accept (Alt); + + elsif Nkind (Alt) = N_Delay_Alternative then + Delay_Count := Delay_Count + 1; + + -- If the delays are relative delays, the delay expressions have + -- type Standard_Duration. Otherwise they must have some time type + -- recognized by GNAT. + + if Nkind (Delay_Statement (Alt)) = N_Delay_Relative_Statement then + Time_Type := Standard_Duration; + else + Time_Type := Etype (Expression (Delay_Statement (Alt))); + + if Is_RTE (Base_Type (Etype (Time_Type)), RO_CA_Time) + or else Is_RTE (Base_Type (Etype (Time_Type)), RO_RT_Time) + then + null; + else + Error_Msg_NE ( + "& is not a time type ('R'M 9.6(6))", + Expression (Delay_Statement (Alt)), Time_Type); + Time_Type := Standard_Duration; + Set_Etype (Expression (Delay_Statement (Alt)), Any_Type); + end if; + end if; + + if No (Condition (Alt)) then + + -- This guard will always be open. + + Check_Guard := False; + end if; + + elsif Nkind (Alt) = N_Terminate_Alternative then + Adjust_Condition (Condition (Alt)); + Terminate_Alt := Alt; + end if; + + Num_Alts := Num_Alts + 1; + Next (Alt); + end loop; + + Else_Present := Present (Else_Statements (N)); + + -- At the same time (see procedure Add_Accept) we build the accept list: + + -- Qnn : Accept_List (1 .. num-select) := ( + -- (null-body, entry-index), + -- (null-body, entry-index), + -- .. + -- (null_body, entry-index)); + + -- In the above declaration, null-body is True if the corresponding + -- accept has no body, and false otherwise. The entry is either the + -- entry index expression if there is no guard, or if a guard is + -- present, then a conditional expression of the form: + + -- (if guard then entry-index else Null_Task_Entry) + + -- If a guard is statically known to be false, the entry can simply + -- be omitted from the accept list. + + Q := + Make_Object_Declaration (Loc, + Defining_Identifier => Qnam, + Object_Definition => + New_Reference_To (RTE (RE_Accept_List), Loc), + Aliased_Present => True, + + Expression => + Make_Qualified_Expression (Loc, + Subtype_Mark => + New_Reference_To (RTE (RE_Accept_List), Loc), + Expression => + Make_Aggregate (Loc, Expressions => Accept_List))); + + Append (Q, Decls); + + -- Then we declare the variable that holds the index for the accept + -- that will be selected for service: + + -- Xnn : Select_Index; + + X := + Make_Object_Declaration (Loc, + Defining_Identifier => Xnam, + Object_Definition => + New_Reference_To (RTE (RE_Select_Index), Loc), + Expression => + New_Reference_To (RTE (RE_No_Rendezvous), Loc)); + + Append (X, Decls); + + -- After this follow procedure declarations for each accept body. + + -- procedure Pnn is + -- begin + -- ... + -- end; + + -- where the ... are statements from the corresponding procedure body. + -- No parameters are involved, since the parameters are passed via Ann + -- and the parameter references have already been expanded to be direct + -- references to Ann (see Exp_Ch2.Expand_Entry_Parameter). Furthermore, + -- any embedded tasking statements (which would normally be illegal in + -- procedures, have been converted to calls to the tasking runtime so + -- there is no problem in putting them into procedures. + + -- The original accept statement has been expanded into a block in + -- the same fashion as for simple accepts (see Build_Accept_Body). + + -- Note: we don't really need to build these procedures for the case + -- where no delay statement is present, but it is just as easy to + -- build them unconditionally, and not significantly inefficient, + -- since if they are short they will be inlined anyway. + + -- The procedure declarations have been assembled in Body_List. + + -- If delays are present, we must compute the required delay. + -- We first generate the declarations: + + -- Delay_Index : Boolean := 0; + -- Delay_Min : Some_Time_Type.Time; + -- Delay_Val : Some_Time_Type.Time; + + -- Delay_Index will be set to the index of the minimum delay, i.e. the + -- active delay that is actually chosen as the basis for the possible + -- delay if an immediate rendez-vous is not possible. + -- In the most common case there is a single delay statement, and this + -- is handled specially. + + if Delay_Count > 0 then + + -- Generate the required declarations + + Delay_Val := + Make_Defining_Identifier (Loc, New_External_Name ('D', 1)); + Delay_Index := + Make_Defining_Identifier (Loc, New_External_Name ('D', 2)); + Delay_Min := + Make_Defining_Identifier (Loc, New_External_Name ('D', 3)); + + Append_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => Delay_Val, + Object_Definition => New_Reference_To (Time_Type, Loc))); + + Append_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => Delay_Index, + Object_Definition => New_Reference_To (Standard_Integer, Loc), + Expression => Make_Integer_Literal (Loc, 0))); + + Append_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => Delay_Min, + Object_Definition => New_Reference_To (Time_Type, Loc), + Expression => + Unchecked_Convert_To (Time_Type, + Make_Attribute_Reference (Loc, + Prefix => + New_Occurrence_Of (Underlying_Type (Time_Type), Loc), + Attribute_Name => Name_Last)))); + + -- Create Duration and Delay_Mode objects used for passing a delay + -- value to RTS + + D := Make_Defining_Identifier (Loc, New_Internal_Name ('D')); + M := Make_Defining_Identifier (Loc, New_Internal_Name ('M')); + + declare + Discr : Entity_Id; + + begin + -- Note that these values are defined in s-osprim.ads and must + -- be kept in sync: + -- + -- Relative : constant := 0; + -- Absolute_Calendar : constant := 1; + -- Absolute_RT : constant := 2; + + if Time_Type = Standard_Duration then + Discr := Make_Integer_Literal (Loc, 0); + + elsif Is_RTE (Base_Type (Etype (Time_Type)), RO_CA_Time) then + Discr := Make_Integer_Literal (Loc, 1); + + else + pragma Assert + (Is_RTE (Base_Type (Etype (Time_Type)), RO_RT_Time)); + Discr := Make_Integer_Literal (Loc, 2); + end if; + + Append_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => D, + Object_Definition => + New_Reference_To (Standard_Duration, Loc))); + + Append_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => M, + Object_Definition => + New_Reference_To (Standard_Integer, Loc), + Expression => Discr)); + end; + + if Check_Guard then + Guard_Open := + Make_Defining_Identifier (Loc, New_External_Name ('G', 1)); + + Append_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => Guard_Open, + Object_Definition => New_Reference_To (Standard_Boolean, Loc), + Expression => New_Reference_To (Standard_False, Loc))); + end if; + + -- Delay_Count is zero, don't need M and D set (suppress warning) + + else + M := Empty; + D := Empty; + end if; + + if Present (Terminate_Alt) then + + -- If the terminate alternative guard is False, use + -- Simple_Mode; otherwise use Terminate_Mode. + + if Present (Condition (Terminate_Alt)) then + Select_Mode := Make_Conditional_Expression (Loc, + New_List (Condition (Terminate_Alt), + New_Reference_To (RTE (RE_Terminate_Mode), Loc), + New_Reference_To (RTE (RE_Simple_Mode), Loc))); + else + Select_Mode := New_Reference_To (RTE (RE_Terminate_Mode), Loc); + end if; + + elsif Else_Present or Delay_Count > 0 then + Select_Mode := New_Reference_To (RTE (RE_Else_Mode), Loc); + + else + Select_Mode := New_Reference_To (RTE (RE_Simple_Mode), Loc); + end if; + + Select_Call := Make_Select_Call (Select_Mode); + Append (Select_Call, Stats); + + -- Now generate code to act on the result. There is an entry + -- in this case for each accept statement with a non-null body, + -- followed by a branch to the statements that follow the Accept. + -- In the absence of delay alternatives, we generate: + + -- case X is + -- when No_Rendezvous => -- omitted if simple mode + -- goto Lab0; + + -- when 1 => + -- P1n; + -- goto Lab1; + + -- when 2 => + -- P2n; + -- goto Lab2; + + -- when others => + -- goto Exit; + -- end case; + -- + -- Lab0: Else_Statements; + -- goto exit; + + -- Lab1: Trailing_Statements1; + -- goto Exit; + -- + -- Lab2: Trailing_Statements2; + -- goto Exit; + -- ... + -- Exit: + + -- Generate label for common exit. + + End_Lab := Make_And_Declare_Label (Num_Alts + 1); + + -- First entry is the default case, when no rendezvous is possible. + + Choices := New_List (New_Reference_To (RTE (RE_No_Rendezvous), Loc)); + + if Else_Present then + + -- If no rendezvous is possible, the else part is executed. + + Lab := Make_And_Declare_Label (0); + Alt_Stats := New_List ( + Make_Goto_Statement (Loc, + Name => New_Copy (Identifier (Lab)))); + + Append (Lab, Trailing_List); + Append_List (Else_Statements (N), Trailing_List); + Append_To (Trailing_List, + Make_Goto_Statement (Loc, + Name => New_Copy (Identifier (End_Lab)))); + else + Alt_Stats := New_List ( + Make_Goto_Statement (Loc, + Name => New_Copy (Identifier (End_Lab)))); + end if; + + Append_To (Alt_List, + Make_Case_Statement_Alternative (Loc, + Discrete_Choices => Choices, + Statements => Alt_Stats)); + + -- We make use of the fact that Accept_Index is an integer type, + -- and generate successive literals for entries for each accept. + -- Only those for which there is a body or trailing statements are + -- given a case entry. + + Alt := First (Select_Alternatives (N)); + Proc := First (Body_List); + + while Present (Alt) loop + + if Nkind (Alt) = N_Accept_Alternative then + Process_Accept_Alternative (Alt, Index, Proc); + Index := Index + 1; + + if Present + (Handled_Statement_Sequence (Accept_Statement (Alt))) + then + Next (Proc); + end if; + + elsif Nkind (Alt) = N_Delay_Alternative then + Process_Delay_Alternative (Alt, Delay_Num); + Delay_Num := Delay_Num + 1; + end if; + + Next (Alt); + end loop; + + -- An others choice is always added to the main case, as well + -- as the delay case (to satisfy the compiler). + + Append_To (Alt_List, + Make_Case_Statement_Alternative (Loc, + Discrete_Choices => + New_List (Make_Others_Choice (Loc)), + Statements => + New_List (Make_Goto_Statement (Loc, + Name => New_Copy (Identifier (End_Lab)))))); + + Accept_Case := New_List ( + Make_Case_Statement (Loc, + Expression => New_Reference_To (Xnam, Loc), + Alternatives => Alt_List)); + + Append_List (Trailing_List, Accept_Case); + Append (End_Lab, Accept_Case); + Append_List (Body_List, Decls); + + -- Construct case statement for trailing statements of delay + -- alternatives, if there are several of them. + + if Delay_Count > 1 then + Append_To (Delay_Alt_List, + Make_Case_Statement_Alternative (Loc, + Discrete_Choices => + New_List (Make_Others_Choice (Loc)), + Statements => + New_List (Make_Null_Statement (Loc)))); + + Delay_Case := New_List ( + Make_Case_Statement (Loc, + Expression => New_Reference_To (Delay_Index, Loc), + Alternatives => Delay_Alt_List)); + else + Delay_Case := Delay_Alt_List; + end if; + + -- If there are no delay alternatives, we append the case statement + -- to the statement list. + + if Delay_Count = 0 then + Append_List (Accept_Case, Stats); + + -- Delay alternatives present + + else + -- If delay alternatives are present we generate: + + -- find minimum delay. + -- DX := minimum delay; + -- M := <delay mode>; + -- Timed_Selective_Wait (Q'Unchecked_Access, Delay_Mode, P, + -- DX, MX, X); + -- + -- if X = No_Rendezvous then + -- case statement for delay statements. + -- else + -- case statement for accept alternatives. + -- end if; + + declare + Cases : Node_Id; + Stmt : Node_Id; + Parms : List_Id; + Parm : Node_Id; + Conv : Node_Id; + + begin + -- The type of the delay expression is known to be legal + + if Time_Type = Standard_Duration then + Conv := New_Reference_To (Delay_Min, Loc); + + elsif Is_RTE (Base_Type (Etype (Time_Type)), RO_CA_Time) then + Conv := Make_Function_Call (Loc, + New_Reference_To (RTE (RO_CA_To_Duration), Loc), + New_List (New_Reference_To (Delay_Min, Loc))); + + else + pragma Assert + (Is_RTE (Base_Type (Etype (Time_Type)), RO_RT_Time)); + + Conv := Make_Function_Call (Loc, + New_Reference_To (RTE (RO_RT_To_Duration), Loc), + New_List (New_Reference_To (Delay_Min, Loc))); + end if; + + Stmt := Make_Assignment_Statement (Loc, + Name => New_Reference_To (D, Loc), + Expression => Conv); + + -- Change the value for Accept_Modes. (Else_Mode -> Delay_Mode) + + Parms := Parameter_Associations (Select_Call); + Parm := First (Parms); + + while Present (Parm) + and then Parm /= Select_Mode + loop + Next (Parm); + end loop; + + pragma Assert (Present (Parm)); + Rewrite (Parm, New_Reference_To (RTE (RE_Delay_Mode), Loc)); + Analyze (Parm); + + -- Prepare two new parameters of Duration and Delay_Mode type + -- which represent the value and the mode of the minimum delay. + + Next (Parm); + Insert_After (Parm, New_Reference_To (M, Loc)); + Insert_After (Parm, New_Reference_To (D, Loc)); + + -- Create a call to RTS. + + Rewrite (Select_Call, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Timed_Selective_Wait), Loc), + Parameter_Associations => Parms)); + + -- This new call should follow the calculation of the + -- minimum delay. + + Insert_List_Before (Select_Call, Delay_List); + + if Check_Guard then + Stmt := + Make_Implicit_If_Statement (N, + Condition => New_Reference_To (Guard_Open, Loc), + Then_Statements => + New_List (New_Copy_Tree (Stmt), + New_Copy_Tree (Select_Call)), + Else_Statements => Accept_Or_Raise); + Rewrite (Select_Call, Stmt); + else + Insert_Before (Select_Call, Stmt); + end if; + + Cases := + Make_Implicit_If_Statement (N, + Condition => Make_Op_Eq (Loc, + Left_Opnd => New_Reference_To (Xnam, Loc), + Right_Opnd => + New_Reference_To (RTE (RE_No_Rendezvous), Loc)), + + Then_Statements => Delay_Case, + Else_Statements => Accept_Case); + + Append (Cases, Stats); + end; + end if; + + -- Replace accept statement with appropriate block + + Block := + Make_Block_Statement (Loc, + Declarations => Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, + Statements => Stats)); + + Rewrite (N, Block); + Analyze (N); + + -- Note: have to worry more about abort deferral in above code ??? + + -- Final step is to unstack the Accept_Address entries for all accept + -- statements appearing in accept alternatives in the select statement + + Alt := First (Alts); + while Present (Alt) loop + if Nkind (Alt) = N_Accept_Alternative then + Remove_Last_Elmt (Accept_Address + (Entity (Entry_Direct_Name (Accept_Statement (Alt))))); + end if; + + Next (Alt); + end loop; + + end Expand_N_Selective_Accept; + + -------------------------------------- + -- Expand_N_Single_Task_Declaration -- + -------------------------------------- + + -- Single task declarations should never be present after semantic + -- analysis, since we expect them to be replaced by a declaration of + -- an anonymous task type, followed by a declaration of the task + -- object. We include this routine to make sure that is happening! + + procedure Expand_N_Single_Task_Declaration (N : Node_Id) is + begin + raise Program_Error; + end Expand_N_Single_Task_Declaration; + + ------------------------ + -- Expand_N_Task_Body -- + ------------------------ + + -- Given a task body + + -- task body tname is + -- <declarations> + -- begin + -- <statements> + -- end x; + + -- This expansion routine converts it into a procedure and sets the + -- elaboration flag for the procedure to true, to represent the fact + -- that the task body is now elaborated: + + -- procedure tnameB (_Task : access tnameV) is + -- discriminal : dtype renames _Task.discriminant; + -- + -- procedure _clean is + -- begin + -- Abort_Defer.all; + -- Complete_Task; + -- Abort_Undefer.all; + -- return; + -- end _clean; + -- begin + -- Abort_Undefer.all; + -- <declarations> + -- System.Task_Stages.Complete_Activation; + -- <statements> + -- at end + -- _clean; + -- end tnameB; + + -- tnameE := True; + + -- In addition, if the task body is an activator, then a call to + -- activate tasks is added at the start of the statements, before + -- the call to Complete_Activation, and if in addition the task is + -- a master then it must be established as a master. These calls are + -- inserted and analyzed in Expand_Cleanup_Actions, when the + -- Handled_Sequence_Of_Statements is expanded. + + -- There is one discriminal declaration line generated for each + -- discriminant that is present to provide an easy reference point + -- for discriminant references inside the body (see Exp_Ch2.Expand_Name). + + -- Note on relationship to GNARLI definition. In the GNARLI definition, + -- task body procedures have a profile (Arg : System.Address). That is + -- needed because GNARLI has to use the same access-to-subprogram type + -- for all task types. We depend here on knowing that in GNAT, passing + -- an address argument by value is identical to passing a record value + -- by access (in either case a single pointer is passed), so even though + -- this procedure has the wrong profile. In fact it's all OK, since the + -- callings sequence is identical. + + procedure Expand_N_Task_Body (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Ttyp : constant Entity_Id := Corresponding_Spec (N); + Call : Node_Id; + New_N : Node_Id; + + begin + Add_Discriminal_Declarations (Declarations (N), Ttyp, Name_uTask, Loc); + + -- Add a call to Abort_Undefer at the very beginning of the task + -- body since this body is called with abort still deferred. + + if Abort_Allowed then + Call := Build_Runtime_Call (Loc, RE_Abort_Undefer); + Insert_Before + (First (Statements (Handled_Statement_Sequence (N))), Call); + Analyze (Call); + end if; + + -- The statement part has already been protected with an at_end and + -- cleanup actions. The call to Complete_Activation must be placed + -- at the head of the sequence of statements of that block. The + -- declarations have been merged in this sequence of statements but + -- the first real statement is accessible from the First_Real_Statement + -- field (which was set for exactly this purpose). + + if Restricted_Profile then + Call := Build_Runtime_Call (Loc, RE_Complete_Restricted_Activation); + else + Call := Build_Runtime_Call (Loc, RE_Complete_Activation); + end if; + + Insert_Before + (First_Real_Statement (Handled_Statement_Sequence (N)), Call); + Analyze (Call); + + New_N := + Make_Subprogram_Body (Loc, + Specification => Build_Task_Proc_Specification (Ttyp), + Declarations => Declarations (N), + Handled_Statement_Sequence => Handled_Statement_Sequence (N)); + + -- If the task contains generic instantiations, cleanup actions + -- are delayed until after instantiation. Transfer the activation + -- chain to the subprogram, to insure that the activation call is + -- properly generated. It the task body contains inner tasks, indicate + -- that the subprogram is a task master. + + if Delay_Cleanups (Ttyp) then + Set_Activation_Chain_Entity (New_N, Activation_Chain_Entity (N)); + Set_Is_Task_Master (New_N, Is_Task_Master (N)); + end if; + + Rewrite (N, New_N); + Analyze (N); + + -- Set elaboration flag immediately after task body. If the body + -- is a subunit, the flag is set in the declarative part that + -- contains the stub. + + if Nkind (Parent (N)) /= N_Subunit then + Insert_After (N, + Make_Assignment_Statement (Loc, + Name => + Make_Identifier (Loc, New_External_Name (Chars (Ttyp), 'E')), + Expression => New_Reference_To (Standard_True, Loc))); + end if; + end Expand_N_Task_Body; + + ------------------------------------ + -- Expand_N_Task_Type_Declaration -- + ------------------------------------ + + -- We have several things to do. First we must create a Boolean flag used + -- to mark if the body is elaborated yet. This variable gets set to True + -- when the body of the task is elaborated (we can't rely on the normal + -- ABE mechanism for the task body, since we need to pass an access to + -- this elaboration boolean to the runtime routines). + + -- taskE : aliased Boolean := False; + + -- Next a variable is declared to hold the task stack size (either + -- the default : Unspecified_Size, or a value that is set by a pragma + -- Storage_Size). If the value of the pragma Storage_Size is static, then + -- the variable is initialized with this value: + + -- taskZ : Size_Type := Unspecified_Size; + -- or + -- taskZ : Size_Type := Size_Type (size_expression); + + -- Next we create a corresponding record type declaration used to represent + -- values of this task. The general form of this type declaration is + + -- type taskV (discriminants) is record + -- _Task_Id : Task_Id; + -- entry_family : array (bounds) of Void; + -- _Priority : Integer := priority_expression; + -- _Size : Size_Type := Size_Type (size_expression); + -- _Task_Info : Task_Info_Type := task_info_expression; + -- _Task_Name : Task_Image_Type := new String'(task_name_expression); + -- end record; + + -- The discriminants are present only if the corresponding task type has + -- discriminants, and they exactly mirror the task type discriminants. + + -- The Id field is always present. It contains the Task_Id value, as + -- set by the call to Create_Task. Note that although the task is + -- limited, the task value record type is not limited, so there is no + -- problem in passing this field as an out parameter to Create_Task. + + -- One entry_family component is present for each entry family in the + -- task definition. The bounds correspond to the bounds of the entry + -- family (which may depend on discriminants). The element type is + -- void, since we only need the bounds information for determining + -- the entry index. Note that the use of an anonymous array would + -- normally be illegal in this context, but this is a parser check, + -- and the semantics is quite prepared to handle such a case. + + -- The _Size field is present only if a Storage_Size pragma appears in + -- the task definition. The expression captures the argument that was + -- present in the pragma, and is used to override the task stack size + -- otherwise associated with the task type. + + -- The _Priority field is present only if a Priority or Interrupt_Priority + -- pragma appears in the task definition. The expression captures the + -- argument that was present in the pragma, and is used to provide + -- the Size parameter to the call to Create_Task. + + -- The _Task_Info field is present only if a Task_Info pragma appears in + -- the task definition. The expression captures the argument that was + -- present in the pragma, and is used to provide the Task_Image parameter + -- to the call to Create_Task. + + -- The _Task_Name field is present only if a Task_Name pragma appears in + -- the task definition. The expression captures the argument that was + -- present in the pragma, and is used to provide the Task_Id parameter + -- to the call to Create_Task. + + -- When a task is declared, an instance of the task value record is + -- created. The elaboration of this declaration creates the correct + -- bounds for the entry families, and also evaluates the size, priority, + -- and task_Info expressions if needed. The initialization routine for + -- the task type itself then calls Create_Task with appropriate + -- parameters to initialize the value of the Task_Id field. + + -- Note: the address of this record is passed as the "Discriminants" + -- parameter for Create_Task. Since Create_Task merely passes this onto + -- the body procedure, it does not matter that it does not quite match + -- the GNARLI model of what is being passed (the record contains more + -- than just the discriminants, but the discriminants can be found from + -- the record value). + + -- The Entity_Id for this created record type is placed in the + -- Corresponding_Record_Type field of the associated task type entity. + + -- Next we create a procedure specification for the task body procedure: + + -- procedure taskB (_Task : access taskV); + + -- Note that this must come after the record type declaration, since + -- the spec refers to this type. It turns out that the initialization + -- procedure for the value type references the task body spec, but that's + -- fine, since it won't be generated till the freeze point for the type, + -- which is certainly after the task body spec declaration. + + -- Finally, we set the task index value field of the entry attribute in + -- the case of a simple entry. + + procedure Expand_N_Task_Type_Declaration (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + Tasktyp : constant Entity_Id := Etype (Defining_Identifier (N)); + Tasknm : constant Name_Id := Chars (Tasktyp); + Taskdef : constant Node_Id := Task_Definition (N); + Proc_Spec : Node_Id; + + Rec_Decl : Node_Id; + Rec_Ent : Entity_Id; + Cdecls : List_Id; + + Elab_Decl : Node_Id; + Size_Decl : Node_Id; + Body_Decl : Node_Id; + + begin + if Present (Corresponding_Record_Type (Tasktyp)) then + return; + + else + Rec_Decl := Build_Corresponding_Record (N, Tasktyp, Loc); + Rec_Ent := Defining_Identifier (Rec_Decl); + Cdecls := Component_Items + (Component_List (Type_Definition (Rec_Decl))); + end if; + + Qualify_Entity_Names (N); + + -- First create the elaboration variable + + Elab_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Sloc (Tasktyp), + Chars => New_External_Name (Tasknm, 'E')), + Aliased_Present => True, + Object_Definition => New_Reference_To (Standard_Boolean, Loc), + Expression => New_Reference_To (Standard_False, Loc)); + Insert_After (N, Elab_Decl); + + -- Next create the declaration of the size variable (tasknmZ) + + Set_Storage_Size_Variable (Tasktyp, + Make_Defining_Identifier (Sloc (Tasktyp), + Chars => New_External_Name (Tasknm, 'Z'))); + + if Present (Taskdef) and then Has_Storage_Size_Pragma (Taskdef) and then + Is_Static_Expression (Expression (First ( + Pragma_Argument_Associations (Find_Task_Or_Protected_Pragma ( + Taskdef, Name_Storage_Size))))) + then + Size_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Storage_Size_Variable (Tasktyp), + Object_Definition => New_Reference_To (RTE (RE_Size_Type), Loc), + Expression => + Convert_To (RTE (RE_Size_Type), + Relocate_Node ( + Expression (First ( + Pragma_Argument_Associations ( + Find_Task_Or_Protected_Pragma + (Taskdef, Name_Storage_Size))))))); + + else + Size_Decl := + Make_Object_Declaration (Loc, + Defining_Identifier => Storage_Size_Variable (Tasktyp), + Object_Definition => New_Reference_To (RTE (RE_Size_Type), Loc), + Expression => New_Reference_To (RTE (RE_Unspecified_Size), Loc)); + end if; + + Insert_After (Elab_Decl, Size_Decl); + + -- Next build the rest of the corresponding record declaration. + -- This is done last, since the corresponding record initialization + -- procedure will reference the previously created entities. + + -- Fill in the component declarations. First the _Task_Id field: + + Append_To (Cdecls, + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uTask_Id), + Subtype_Indication => New_Reference_To (RTE (RO_ST_Task_ID), Loc))); + + -- Add components for entry families + + Collect_Entry_Families (Loc, Cdecls, Size_Decl, Tasktyp); + + -- Add the _Priority component if a Priority pragma is present + + if Present (Taskdef) and then Has_Priority_Pragma (Taskdef) then + Append_To (Cdecls, + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uPriority), + Subtype_Indication => New_Reference_To (Standard_Integer, Loc), + Expression => New_Copy ( + Expression (First ( + Pragma_Argument_Associations ( + Find_Task_Or_Protected_Pragma + (Taskdef, Name_Priority))))))); + end if; + + -- Add the _Task_Size component if a Storage_Size pragma is present + + if Present (Taskdef) + and then Has_Storage_Size_Pragma (Taskdef) + then + Append_To (Cdecls, + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uSize), + + Subtype_Indication => New_Reference_To (RTE (RE_Size_Type), Loc), + + Expression => + Convert_To (RTE (RE_Size_Type), + Relocate_Node ( + Expression (First ( + Pragma_Argument_Associations ( + Find_Task_Or_Protected_Pragma + (Taskdef, Name_Storage_Size)))))))); + end if; + + -- Add the _Task_Info component if a Task_Info pragma is present + + if Present (Taskdef) and then Has_Task_Info_Pragma (Taskdef) then + Append_To (Cdecls, + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uTask_Info), + Subtype_Indication => + New_Reference_To (RTE (RE_Task_Info_Type), Loc), + Expression => New_Copy ( + Expression (First ( + Pragma_Argument_Associations ( + Find_Task_Or_Protected_Pragma + (Taskdef, Name_Task_Info))))))); + end if; + + -- Add the _Task_Name component if a Task_Name pragma is present + + if Present (Taskdef) and then Has_Task_Name_Pragma (Taskdef) then + Append_To (Cdecls, + Make_Component_Declaration (Loc, + Defining_Identifier => + Make_Defining_Identifier (Loc, Name_uTask_Info), + Subtype_Indication => + New_Reference_To (RTE (RE_Task_Image_Type), Loc), + Expression => + Make_Allocator (Loc, + Expression => + Make_Qualified_Expression (Loc, + Subtype_Mark => + New_Occurrence_Of (Standard_String, Loc), + Expression => + New_Copy ( + Expression (First ( + Pragma_Argument_Associations ( + Find_Task_Or_Protected_Pragma + (Taskdef, Name_Task_Name))))))))); + end if; + + Insert_After (Size_Decl, Rec_Decl); + + -- Analyze the record declaration immediately after construction, + -- because the initialization procedure is needed for single task + -- declarations before the next entity is analyzed. + + Analyze (Rec_Decl); + + -- Create the declaration of the task body procedure + + Proc_Spec := Build_Task_Proc_Specification (Tasktyp); + Body_Decl := + Make_Subprogram_Declaration (Loc, + Specification => Proc_Spec); + + Insert_After (Rec_Decl, Body_Decl); + + -- Now we can freeze the corresponding record. This needs manually + -- freezing, since it is really part of the task type, and the task + -- type is frozen at this stage. We of course need the initialization + -- procedure for this corresponding record type and we won't get it + -- in time if we don't freeze now. + + declare + L : constant List_Id := Freeze_Entity (Rec_Ent, Loc); + + begin + if Is_Non_Empty_List (L) then + Insert_List_After (Body_Decl, L); + end if; + end; + + -- Complete the expansion of access types to the current task + -- type, if any were declared. + + Expand_Previous_Access_Type (N, Tasktyp); + end Expand_N_Task_Type_Declaration; + + ------------------------------- + -- Expand_N_Timed_Entry_Call -- + ------------------------------- + + -- A timed entry call in normal case is not implemented using ATC + -- mechanism anymore for efficiency reason. + + -- select + -- T.E; + -- S1; + -- or + -- Delay D; + -- S2; + -- end select; + + -- is expanded as follow: + + -- 1) When T.E is a task entry_call; + + -- declare + -- B : Boolean; + -- X : Task_Entry_Index := <entry index>; + -- DX : Duration := To_Duration (D); + -- M : Delay_Mode := <discriminant>; + -- P : parms := (parm, parm, parm); + + -- begin + -- Timed_Protected_Entry_Call (<acceptor-task>, X, P'Address, + -- DX, M, B); + -- if B then + -- S1; + -- else + -- S2; + -- end if; + -- end; + + -- 2) When T.E is a protected entry_call; + + -- declare + -- B : Boolean; + -- X : Protected_Entry_Index := <entry index>; + -- DX : Duration := To_Duration (D); + -- M : Delay_Mode := <discriminant>; + -- P : parms := (parm, parm, parm); + + -- begin + -- Timed_Protected_Entry_Call (<object>'unchecked_access, X, + -- P'Address, DX, M, B); + -- if B then + -- S1; + -- else + -- S2; + -- end if; + -- end; + + procedure Expand_N_Timed_Entry_Call (N : Node_Id) is + Loc : constant Source_Ptr := Sloc (N); + + E_Call : Node_Id := + Entry_Call_Statement (Entry_Call_Alternative (N)); + E_Stats : constant List_Id := + Statements (Entry_Call_Alternative (N)); + D_Stat : constant Node_Id := + Delay_Statement (Delay_Alternative (N)); + D_Stats : constant List_Id := + Statements (Delay_Alternative (N)); + + Stmts : List_Id; + Stmt : Node_Id; + Parms : List_Id; + Parm : Node_Id; + + Concval : Node_Id; + Ename : Node_Id; + Index : Node_Id; + + Decls : List_Id; + Disc : Node_Id; + Conv : Node_Id; + B : Entity_Id; + D : Entity_Id; + Dtyp : Entity_Id; + M : Entity_Id; + + Call : Node_Id; + Dummy : Node_Id; + + begin + -- The arguments in the call may require dynamic allocation, and the + -- call statement may have been transformed into a block. The block + -- may contain additional declarations for internal entities, and the + -- original call is found by sequential search. + + if Nkind (E_Call) = N_Block_Statement then + E_Call := First (Statements (Handled_Statement_Sequence (E_Call))); + + while Nkind (E_Call) /= N_Procedure_Call_Statement + and then Nkind (E_Call) /= N_Entry_Call_Statement + loop + Next (E_Call); + end loop; + end if; + + -- Build an entry call using Simple_Entry_Call. We will use this as the + -- base for creating appropriate calls. + + Extract_Entry (E_Call, Concval, Ename, Index); + Build_Simple_Entry_Call (E_Call, Concval, Ename, Index); + + Stmts := Statements (Handled_Statement_Sequence (E_Call)); + Decls := Declarations (E_Call); + + if No (Decls) then + Decls := New_List; + end if; + + Dtyp := Base_Type (Etype (Expression (D_Stat))); + + -- Use the type of the delay expression (Calendar or Real_Time) + -- to generate the appropriate conversion. + + if Nkind (D_Stat) = N_Delay_Relative_Statement then + Disc := Make_Integer_Literal (Loc, 0); + Conv := Relocate_Node (Expression (D_Stat)); + + elsif Is_RTE (Dtyp, RO_CA_Time) then + Disc := Make_Integer_Literal (Loc, 1); + Conv := Make_Function_Call (Loc, + New_Reference_To (RTE (RO_CA_To_Duration), Loc), + New_List (New_Copy (Expression (D_Stat)))); + + else pragma Assert (Is_RTE (Dtyp, RO_RT_Time)); + Disc := Make_Integer_Literal (Loc, 2); + Conv := Make_Function_Call (Loc, + New_Reference_To (RTE (RO_RT_To_Duration), Loc), + New_List (New_Copy (Expression (D_Stat)))); + end if; + + -- Create a Duration and a Delay_Mode object used for passing a delay + -- value + + D := Make_Defining_Identifier (Loc, New_Internal_Name ('D')); + M := Make_Defining_Identifier (Loc, New_Internal_Name ('M')); + + Append_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => D, + Object_Definition => New_Reference_To (Standard_Duration, Loc))); + + Append_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => M, + Object_Definition => New_Reference_To (Standard_Integer, Loc), + Expression => Disc)); + + B := Make_Defining_Identifier (Loc, Name_uB); + + -- Create a boolean object used for a return parameter. + + Prepend_To (Decls, + Make_Object_Declaration (Loc, + Defining_Identifier => B, + Object_Definition => New_Reference_To (Standard_Boolean, Loc))); + + Stmt := First (Stmts); + + -- Skip assignments to temporaries created for in-out parameters. + -- This makes unwarranted assumptions about the shape of the expanded + -- tree for the call, and should be cleaned up ??? + + while Nkind (Stmt) /= N_Procedure_Call_Statement loop + Next (Stmt); + end loop; + + -- Do the assignement at this stage only because the evaluation of the + -- expression must not occur before (see ACVC C97302A). + + Insert_Before (Stmt, + Make_Assignment_Statement (Loc, + Name => New_Reference_To (D, Loc), + Expression => Conv)); + + Call := Stmt; + + Parms := Parameter_Associations (Call); + + -- For a protected type, we build a Timed_Protected_Entry_Call + + if Is_Protected_Type (Etype (Concval)) then + + -- Create a new call statement + + Parm := First (Parms); + + while Present (Parm) + and then not Is_RTE (Etype (Parm), RE_Call_Modes) + loop + Next (Parm); + end loop; + + Dummy := Remove_Next (Next (Parm)); + + -- In case some garbage is following the Cancel_Param, remove. + + Dummy := Next (Parm); + + -- Remove the mode of the Protected_Entry_Call call, the + -- Communication_Block of the Protected_Entry_Call call, and add a + -- Duration and a Delay_Mode parameter + + pragma Assert (Present (Parm)); + Rewrite (Parm, New_Reference_To (D, Loc)); + + Rewrite (Dummy, New_Reference_To (M, Loc)); + + -- Add a Boolean flag for successful entry call. + + Append_To (Parms, New_Reference_To (B, Loc)); + + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Number_Entries (Etype (Concval)) > 1 + then + Rewrite (Call, + Make_Procedure_Call_Statement (Loc, + Name => + New_Reference_To (RTE (RE_Timed_Protected_Entry_Call), Loc), + Parameter_Associations => Parms)); + + else + Parm := First (Parms); + + while Present (Parm) + and then not Is_RTE (Etype (Parm), RE_Protected_Entry_Index) + loop + Next (Parm); + end loop; + + Remove (Parm); + + Rewrite (Call, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To ( + RTE (RE_Timed_Protected_Single_Entry_Call), Loc), + Parameter_Associations => Parms)); + end if; + + -- For the task case, build a Timed_Task_Entry_Call + + else + -- Create a new call statement + + Append_To (Parms, New_Reference_To (D, Loc)); + Append_To (Parms, New_Reference_To (M, Loc)); + Append_To (Parms, New_Reference_To (B, Loc)); + + Rewrite (Call, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Timed_Task_Entry_Call), Loc), + Parameter_Associations => Parms)); + + end if; + + Append_To (Stmts, + Make_Implicit_If_Statement (N, + Condition => New_Reference_To (B, Loc), + Then_Statements => E_Stats, + Else_Statements => D_Stats)); + + Rewrite (N, + Make_Block_Statement (Loc, + Declarations => Decls, + Handled_Statement_Sequence => + Make_Handled_Sequence_Of_Statements (Loc, Stmts))); + + Analyze (N); + + end Expand_N_Timed_Entry_Call; + + ---------------------------------------- + -- Expand_Protected_Body_Declarations -- + ---------------------------------------- + + -- Part of the expansion of a protected body involves the creation of + -- a declaration that can be referenced from the statement sequences of + -- the entry bodies: + + -- A : Address; + + -- This declaration is inserted in the declarations of the service + -- entries procedure for the protected body, and it is important that + -- it be inserted before the statements of the entry body statement + -- sequences are analyzed. Thus it would be too late to create this + -- declaration in the Expand_N_Protected_Body routine, which is why + -- there is a separate procedure to be called directly from Sem_Ch9. + + -- Ann is used to hold the address of the record containing the parameters + -- (see Expand_N_Entry_Call for more details on how this record is built). + -- References to the parameters do an unchecked conversion of this address + -- to a pointer to the required record type, and then access the field that + -- holds the value of the required parameter. The entity for the address + -- variable is held as the top stack element (i.e. the last element) of the + -- Accept_Address stack in the corresponding entry entity, and this element + -- must be set in place before the statements are processed. + + -- No stack is needed for entry bodies, since they cannot be nested, but + -- it is kept for consistency between protected and task entries. The + -- stack will never contain more than one element. There is also only one + -- such variable for a given protected body, but this is placed on the + -- Accept_Address stack of all of the entries, again for consistency. + + -- To expand the requeue statement, a label is provided at the end of + -- the loop in the entry service routine created by the expander (see + -- Expand_N_Protected_Body for details), so that the statement can be + -- skipped after the requeue is complete. This label is created during the + -- expansion of the entry body, which will take place after the expansion + -- of the requeue statements that it contains, so a placeholder defining + -- identifier is associated with the task type here. + + -- Another label is provided following case statement created by the + -- expander. This label is need for implementing return statement from + -- entry body so that a return can be expanded as a goto to this label. + -- This label is created during the expansion of the entry body, which + -- will take place after the expansion of the return statements that it + -- contains. Therefore, just like the label for expanding requeues, we + -- need another placeholder for the label. + + procedure Expand_Protected_Body_Declarations + (N : Node_Id; + Spec_Id : Entity_Id) + is + Op : Node_Id; + + begin + if Expander_Active then + + -- Associate privals with the first subprogram or entry + -- body to be expanded. These are used to expand references + -- to private data objects. + + Op := First_Protected_Operation (Declarations (N)); + + if Present (Op) then + Set_Discriminals (Parent (Spec_Id), Op, Sloc (N)); + Set_Privals (Parent (Spec_Id), Op, Sloc (N)); + end if; + end if; + end Expand_Protected_Body_Declarations; + + ------------------------- + -- External_Subprogram -- + ------------------------- + + function External_Subprogram (E : Entity_Id) return Entity_Id is + Subp : constant Entity_Id := Protected_Body_Subprogram (E); + Decl : constant Node_Id := Unit_Declaration_Node (E); + + begin + -- If the protected operation is defined in the visible part of the + -- protected type, or if it is an interrupt handler, the internal and + -- external subprograms follow each other on the entity chain. If the + -- operation is defined in the private part of the type, there is no + -- need for a separate locking version of the operation, and internal + -- calls use the protected_body_subprogram directly. + + if List_Containing (Decl) = Visible_Declarations (Parent (Decl)) + or else Is_Interrupt_Handler (E) + then + return Next_Entity (Subp); + else + return (Subp); + end if; + end External_Subprogram; + + ------------------- + -- Extract_Entry -- + ------------------- + + procedure Extract_Entry + (N : Node_Id; + Concval : out Node_Id; + Ename : out Node_Id; + Index : out Node_Id) + is + Nam : constant Node_Id := Name (N); + + begin + -- For a simple entry, the name is a selected component, with the + -- prefix being the task value, and the selector being the entry. + + if Nkind (Nam) = N_Selected_Component then + Concval := Prefix (Nam); + Ename := Selector_Name (Nam); + Index := Empty; + + -- For a member of an entry family, the name is an indexed + -- component where the prefix is a selected component, + -- whose prefix in turn is the task value, and whose + -- selector is the entry family. The single expression in + -- the expressions list of the indexed component is the + -- subscript for the family. + + else + pragma Assert (Nkind (Nam) = N_Indexed_Component); + Concval := Prefix (Prefix (Nam)); + Ename := Selector_Name (Prefix (Nam)); + Index := First (Expressions (Nam)); + end if; + + end Extract_Entry; + + ------------------- + -- Family_Offset -- + ------------------- + + function Family_Offset + (Loc : Source_Ptr; + Hi : Node_Id; + Lo : Node_Id; + Ttyp : Entity_Id) + return Node_Id + is + function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id; + -- If one of the bounds is a reference to a discriminant, replace + -- with corresponding discriminal of type. Within the body of a task + -- retrieve the renamed discriminant by simple visibility, using its + -- generated name. Within a protected object, find the original dis- + -- criminant and replace it with the discriminal of the current prot- + -- ected operation. + + ------------------------------ + -- Convert_Discriminant_Ref -- + ------------------------------ + + function Convert_Discriminant_Ref (Bound : Node_Id) return Node_Id is + Loc : constant Source_Ptr := Sloc (Bound); + B : Node_Id; + D : Entity_Id; + + begin + if Is_Entity_Name (Bound) + and then Ekind (Entity (Bound)) = E_Discriminant + then + if Is_Task_Type (Ttyp) + and then Has_Completion (Ttyp) + then + B := Make_Identifier (Loc, Chars (Entity (Bound))); + Find_Direct_Name (B); + + elsif Is_Protected_Type (Ttyp) then + D := First_Discriminant (Ttyp); + + while Chars (D) /= Chars (Entity (Bound)) loop + Next_Discriminant (D); + end loop; + + B := New_Reference_To (Discriminal (D), Loc); + + else + B := New_Reference_To (Discriminal (Entity (Bound)), Loc); + end if; + + elsif Nkind (Bound) = N_Attribute_Reference then + return Bound; + + else + B := New_Copy_Tree (Bound); + end if; + + return + Make_Attribute_Reference (Loc, + Attribute_Name => Name_Pos, + Prefix => New_Occurrence_Of (Etype (Bound), Loc), + Expressions => New_List (B)); + end Convert_Discriminant_Ref; + + -- Start of processing for Family_Offset + + begin + return + Make_Op_Subtract (Loc, + Left_Opnd => Convert_Discriminant_Ref (Hi), + Right_Opnd => Convert_Discriminant_Ref (Lo)); + + end Family_Offset; + + ----------------- + -- Family_Size -- + ----------------- + + function Family_Size + (Loc : Source_Ptr; + Hi : Node_Id; + Lo : Node_Id; + Ttyp : Entity_Id) + return Node_Id + is + Ityp : Entity_Id; + + begin + if Is_Task_Type (Ttyp) then + Ityp := RTE (RE_Task_Entry_Index); + else + Ityp := RTE (RE_Protected_Entry_Index); + end if; + + return + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Ityp, Loc), + Attribute_Name => Name_Max, + Expressions => New_List ( + Make_Op_Add (Loc, + Left_Opnd => + Family_Offset (Loc, Hi, Lo, Ttyp), + Right_Opnd => + Make_Integer_Literal (Loc, 1)), + Make_Integer_Literal (Loc, 0))); + end Family_Size; + + ----------------------------------- + -- Find_Task_Or_Protected_Pragma -- + ----------------------------------- + + function Find_Task_Or_Protected_Pragma + (T : Node_Id; + P : Name_Id) + return Node_Id + is + N : Node_Id; + + begin + N := First (Visible_Declarations (T)); + + while Present (N) loop + if Nkind (N) = N_Pragma then + if Chars (N) = P then + return N; + + elsif P = Name_Priority + and then Chars (N) = Name_Interrupt_Priority + then + return N; + + else + Next (N); + end if; + + else + Next (N); + end if; + end loop; + + N := First (Private_Declarations (T)); + + while Present (N) loop + if Nkind (N) = N_Pragma then + if Chars (N) = P then + return N; + + elsif P = Name_Priority + and then Chars (N) = Name_Interrupt_Priority + then + return N; + + else + Next (N); + end if; + + else + Next (N); + end if; + end loop; + + raise Program_Error; + end Find_Task_Or_Protected_Pragma; + + ------------------------------- + -- First_Protected_Operation -- + ------------------------------- + + function First_Protected_Operation (D : List_Id) return Node_Id is + First_Op : Node_Id; + + begin + First_Op := First (D); + while Present (First_Op) + and then Nkind (First_Op) /= N_Subprogram_Body + and then Nkind (First_Op) /= N_Entry_Body + loop + Next (First_Op); + end loop; + + return First_Op; + end First_Protected_Operation; + + -------------------------------- + -- Index_Constant_Declaration -- + -------------------------------- + + function Index_Constant_Declaration + (N : Node_Id; + Index_Id : Entity_Id; + Prot : Entity_Id) + return List_Id + is + Loc : constant Source_Ptr := Sloc (N); + Decls : List_Id := New_List; + Index_Con : constant Entity_Id := Entry_Index_Constant (Index_Id); + Index_Typ : Entity_Id; + + Hi : Node_Id := Type_High_Bound (Etype (Index_Id)); + Lo : Node_Id := Type_Low_Bound (Etype (Index_Id)); + + function Replace_Discriminant (Bound : Node_Id) return Node_Id; + -- The bounds of the entry index may depend on discriminants, so + -- each declaration of an entry_index_constant must have its own + -- subtype declaration, using the local renaming of the object discri- + -- minant. + + -------------------------- + -- Replace_Discriminant -- + -------------------------- + + function Replace_Discriminant (Bound : Node_Id) return Node_Id is + begin + if Nkind (Bound) = N_Identifier + and then Ekind (Entity (Bound)) = E_Constant + and then Present (Discriminal_Link (Entity (Bound))) + then + return Make_Identifier (Loc, Chars (Entity (Bound))); + else + return Duplicate_Subexpr (Bound); + end if; + end Replace_Discriminant; + + -- Start of processing for Index_Constant_Declaration + + begin + Set_Discriminal_Link (Index_Con, Index_Id); + + if Is_Entity_Name ( + Original_Node (Discrete_Subtype_Definition (Parent (Index_Id)))) + then + -- Simple case: entry family is given by a subtype mark, and index + -- constant has the same type, no replacement needed. + + Index_Typ := Etype (Index_Id); + + else + Hi := Replace_Discriminant (Hi); + Lo := Replace_Discriminant (Lo); + + Index_Typ := Make_Defining_Identifier (Loc, New_Internal_Name ('I')); + + Append ( + Make_Subtype_Declaration (Loc, + Defining_Identifier => Index_Typ, + Subtype_Indication => + Make_Subtype_Indication (Loc, + Subtype_Mark => + New_Occurrence_Of (Base_Type (Etype (Index_Id)), Loc), + Constraint => + Make_Range_Constraint (Loc, + Range_Expression => Make_Range (Loc, Lo, Hi)))), + Decls); + + end if; + + Append ( + Make_Object_Declaration (Loc, + Defining_Identifier => Index_Con, + Constant_Present => True, + Object_Definition => New_Occurrence_Of (Index_Typ, Loc), + + Expression => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Index_Typ, Loc), + Attribute_Name => Name_Val, + + Expressions => New_List ( + + Make_Op_Add (Loc, + Left_Opnd => + Make_Op_Subtract (Loc, + Left_Opnd => Make_Identifier (Loc, Name_uE), + Right_Opnd => + Entry_Index_Expression (Loc, + Defining_Identifier (N), Empty, Prot)), + + Right_Opnd => + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Index_Typ, Loc), + Attribute_Name => Name_Pos, + Expressions => New_List ( + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (Index_Typ, Loc), + Attribute_Name => Name_First))))))), + Decls); + + return Decls; + end Index_Constant_Declaration; + + -------------------------------- + -- Make_Initialize_Protection -- + -------------------------------- + + function Make_Initialize_Protection + (Protect_Rec : Entity_Id) + return List_Id + is + Loc : constant Source_Ptr := Sloc (Protect_Rec); + P_Arr : Entity_Id; + Pdef : Node_Id; + Pdec : Node_Id; + Ptyp : Node_Id; + Pnam : Name_Id; + Args : List_Id; + L : List_Id := New_List; + + begin + -- We may need two calls to properly initialize the object, one + -- to Initialize_Protection, and possibly one to Install_Handlers + -- if we have a pragma Attach_Handler. + + Ptyp := Corresponding_Concurrent_Type (Protect_Rec); + Pnam := Chars (Ptyp); + + -- Get protected declaration. In the case of a task type declaration, + -- this is simply the parent of the protected type entity. + -- In the single protected object + -- declaration, this parent will be the implicit type, and we can find + -- the corresponding single protected object declaration by + -- searching forward in the declaration list in the tree. + -- ??? I am not sure that the test for N_Single_Protected_Declaration + -- is needed here. Nodes of this type should have been removed + -- during semantic analysis. + + Pdec := Parent (Ptyp); + + while Nkind (Pdec) /= N_Protected_Type_Declaration + and then Nkind (Pdec) /= N_Single_Protected_Declaration + loop + Next (Pdec); + end loop; + + -- Now we can find the object definition from this declaration + + Pdef := Protected_Definition (Pdec); + + -- Build the parameter list for the call. Note that _Init is the name + -- of the formal for the object to be initialized, which is the task + -- value record itself. + + Args := New_List; + + -- Object parameter. This is a pointer to the object of type + -- Protection used by the GNARL to control the protected object. + + Append_To (Args, + Make_Attribute_Reference (Loc, + Prefix => + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Selector_Name => Make_Identifier (Loc, Name_uObject)), + Attribute_Name => Name_Unchecked_Access)); + + -- Priority parameter. Set to Unspecified_Priority unless there is a + -- priority pragma, in which case we take the value from the pragma, + -- or there is an interrupt pragma and no priority pragma, and we + -- set the ceiling to Interrupt_Priority'Last, an implementation- + -- defined value, see D.3(10). + + if Present (Pdef) + and then Has_Priority_Pragma (Pdef) + then + Append_To (Args, + Duplicate_Subexpr (Expression (First (Pragma_Argument_Associations + (Find_Task_Or_Protected_Pragma (Pdef, Name_Priority)))))); + + elsif Has_Interrupt_Handler (Ptyp) + or else Has_Attach_Handler (Ptyp) + then + -- When no priority is specified but an xx_Handler pragma is, + -- we default to System.Interrupts.Default_Interrupt_Priority, + -- see D.3(10). + + Append_To (Args, + New_Reference_To (RTE (RE_Default_Interrupt_Priority), Loc)); + + else + Append_To (Args, + New_Reference_To (RTE (RE_Unspecified_Priority), Loc)); + end if; + + if Has_Entries (Ptyp) + or else Has_Interrupt_Handler (Ptyp) + or else Has_Attach_Handler (Ptyp) + then + -- Compiler_Info parameter. This parameter allows entry body + -- procedures and barrier functions to be called from the runtime. + -- It is a pointer to the record generated by the compiler to + -- represent the protected object. + + Append_To (Args, + Make_Attribute_Reference (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Attribute_Name => Name_Address)); + + if Has_Entries (Ptyp) then + -- Entry_Bodies parameter. This is a pointer to an array of + -- pointers to the entry body procedures and barrier functions + -- of the object. If the protected type has no entries this + -- object will not exist; in this case, pass a null. + + P_Arr := Entry_Bodies_Array (Ptyp); + + Append_To (Args, + Make_Attribute_Reference (Loc, + Prefix => New_Reference_To (P_Arr, Loc), + Attribute_Name => Name_Unrestricted_Access)); + + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Number_Entries (Ptyp) > 1 + then + -- Find index mapping function (clumsy but ok for now). + + while Ekind (P_Arr) /= E_Function loop + Next_Entity (P_Arr); + end loop; + + Append_To (Args, + Make_Attribute_Reference (Loc, + Prefix => + New_Reference_To (P_Arr, Loc), + Attribute_Name => Name_Unrestricted_Access)); + end if; + + else + Append_To (Args, Make_Null (Loc)); + Append_To (Args, Make_Null (Loc)); + end if; + + if Abort_Allowed + or else Restrictions (No_Entry_Queue) = False + or else Number_Entries (Ptyp) > 1 + then + Append_To (L, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To ( + RTE (RE_Initialize_Protection_Entries), Loc), + Parameter_Associations => Args)); + + else + Append_To (L, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To ( + RTE (RE_Initialize_Protection_Entry), Loc), + Parameter_Associations => Args)); + end if; + + else + Append_To (L, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Initialize_Protection), Loc), + Parameter_Associations => Args)); + end if; + + if Has_Attach_Handler (Ptyp) then + + -- We have a list of N Attach_Handler (ProcI, ExprI), + -- and we have to make the following call: + -- Install_Handlers (_object, + -- ((Expr1, Proc1'access), ...., (ExprN, ProcN'access)); + + declare + Args : List_Id := New_List; + Table : List_Id := New_List; + Ritem : Node_Id := First_Rep_Item (Ptyp); + + begin + -- Appends the _object argument + + Append_To (Args, + Make_Attribute_Reference (Loc, + Prefix => + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Selector_Name => Make_Identifier (Loc, Name_uObject)), + Attribute_Name => Name_Unchecked_Access)); + + -- Build the Attach_Handler table argument + + while Present (Ritem) loop + if Nkind (Ritem) = N_Pragma + and then Chars (Ritem) = Name_Attach_Handler + then + declare + Handler : Node_Id := + First (Pragma_Argument_Associations (Ritem)); + Interrupt : Node_Id := + Next (Handler); + + begin + Append_To (Table, + Make_Aggregate (Loc, Expressions => New_List ( + Duplicate_Subexpr (Expression (Interrupt)), + Make_Attribute_Reference (Loc, + Prefix => Make_Selected_Component (Loc, + Make_Identifier (Loc, Name_uInit), + Duplicate_Subexpr (Expression (Handler))), + Attribute_Name => Name_Access)))); + end; + end if; + + Next_Rep_Item (Ritem); + end loop; + + -- Appends the table argument we just built. + Append_To (Args, Make_Aggregate (Loc, Table)); + + -- Appends the Install_Handler call to the statements. + Append_To (L, + Make_Procedure_Call_Statement (Loc, + Name => New_Reference_To (RTE (RE_Install_Handlers), Loc), + Parameter_Associations => Args)); + end; + end if; + + return L; + end Make_Initialize_Protection; + + --------------------------- + -- Make_Task_Create_Call -- + --------------------------- + + function Make_Task_Create_Call (Task_Rec : Entity_Id) return Node_Id is + Loc : constant Source_Ptr := Sloc (Task_Rec); + Name : Node_Id; + Tdef : Node_Id; + Tdec : Node_Id; + Ttyp : Node_Id; + Tnam : Name_Id; + Args : List_Id; + Ecount : Node_Id; + + begin + Ttyp := Corresponding_Concurrent_Type (Task_Rec); + Tnam := Chars (Ttyp); + + -- Get task declaration. In the case of a task type declaration, this + -- is simply the parent of the task type entity. In the single task + -- declaration, this parent will be the implicit type, and we can find + -- the corresponding single task declaration by searching forward in + -- the declaration list in the tree. + -- ??? I am not sure that the test for N_Single_Task_Declaration + -- is needed here. Nodes of this type should have been removed + -- during semantic analysis. + + Tdec := Parent (Ttyp); + + while Nkind (Tdec) /= N_Task_Type_Declaration + and then Nkind (Tdec) /= N_Single_Task_Declaration + loop + Next (Tdec); + end loop; + + -- Now we can find the task definition from this declaration + + Tdef := Task_Definition (Tdec); + + -- Build the parameter list for the call. Note that _Init is the name + -- of the formal for the object to be initialized, which is the task + -- value record itself. + + Args := New_List; + + -- Priority parameter. Set to Unspecified_Priority unless there is a + -- priority pragma, in which case we take the value from the pragma. + + if Present (Tdef) + and then Has_Priority_Pragma (Tdef) + then + Append_To (Args, + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Selector_Name => Make_Identifier (Loc, Name_uPriority))); + + else + Append_To (Args, + New_Reference_To (RTE (RE_Unspecified_Priority), Loc)); + end if; + + -- Size parameter. If no Storage_Size pragma is present, then + -- the size is taken from the taskZ variable for the type, which + -- is either Unspecified_Size, or has been reset by the use of + -- a Storage_Size attribute definition clause. If a pragma is + -- present, then the size is taken from the _Size field of the + -- task value record, which was set from the pragma value. + + if Present (Tdef) + and then Has_Storage_Size_Pragma (Tdef) + then + Append_To (Args, + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Selector_Name => Make_Identifier (Loc, Name_uSize))); + + else + Append_To (Args, + New_Reference_To (Storage_Size_Variable (Ttyp), Loc)); + end if; + + -- Task_Info parameter. Set to Unspecified_Task_Info unless there is a + -- Task_Info pragma, in which case we take the value from the pragma. + + if Present (Tdef) + and then Has_Task_Info_Pragma (Tdef) + then + Append_To (Args, + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Selector_Name => Make_Identifier (Loc, Name_uTask_Info))); + + else + Append_To (Args, + New_Reference_To (RTE (RE_Unspecified_Task_Info), Loc)); + end if; + + if not Restricted_Profile then + + -- Number of entries. This is an expression of the form: + -- + -- n + _Init.a'Length + _Init.a'B'Length + ... + -- + -- where a,b... are the entry family names for the task definition + + Ecount := Build_Entry_Count_Expression ( + Ttyp, + Component_Items (Component_List ( + Type_Definition (Parent ( + Corresponding_Record_Type (Ttyp))))), + Loc); + Append_To (Args, Ecount); + + -- Master parameter. This is a reference to the _Master parameter of + -- the initialization procedure, except in the case of the pragma + -- Restrictions (No_Task_Hierarchy) where the value is fixed to 3. + -- See comments in System.Tasking.Initialization.Init_RTS for the + -- value 3. + + if Restrictions (No_Task_Hierarchy) = False then + Append_To (Args, Make_Identifier (Loc, Name_uMaster)); + else + Append_To (Args, Make_Integer_Literal (Loc, 3)); + end if; + end if; + + -- State parameter. This is a pointer to the task body procedure. The + -- required value is obtained by taking the address of the task body + -- procedure and converting it (with an unchecked conversion) to the + -- type required by the task kernel. For further details, see the + -- description of Expand_Task_Body + + Append_To (Args, + Unchecked_Convert_To (RTE (RE_Task_Procedure_Access), + Make_Attribute_Reference (Loc, + Prefix => + New_Occurrence_Of (Get_Task_Body_Procedure (Ttyp), Loc), + Attribute_Name => Name_Address))); + + -- Discriminants parameter. This is just the address of the task + -- value record itself (which contains the discriminant values + + Append_To (Args, + Make_Attribute_Reference (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Attribute_Name => Name_Address)); + + -- Elaborated parameter. This is an access to the elaboration Boolean + + Append_To (Args, + Make_Attribute_Reference (Loc, + Prefix => Make_Identifier (Loc, New_External_Name (Tnam, 'E')), + Attribute_Name => Name_Unchecked_Access)); + + -- Chain parameter. This is a reference to the _Chain parameter of + -- the initialization procedure. + + Append_To (Args, Make_Identifier (Loc, Name_uChain)); + + -- Task name parameter. Take this from the _Task_Info parameter to the + -- init call unless there is a Task_Name pragma, in which case we take + -- the value from the pragma. + + if Present (Tdef) + and then Has_Task_Name_Pragma (Tdef) + then + Append_To (Args, + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Selector_Name => Make_Identifier (Loc, Name_uTask_Info))); + + else + Append_To (Args, Make_Identifier (Loc, Name_uTask_Id)); + end if; + + -- Created_Task parameter. This is the _Task_Id field of the task + -- record value + + Append_To (Args, + Make_Selected_Component (Loc, + Prefix => Make_Identifier (Loc, Name_uInit), + Selector_Name => Make_Identifier (Loc, Name_uTask_Id))); + + if Restricted_Profile then + Name := New_Reference_To (RTE (RE_Create_Restricted_Task), Loc); + else + Name := New_Reference_To (RTE (RE_Create_Task), Loc); + end if; + + return Make_Procedure_Call_Statement (Loc, + Name => Name, Parameter_Associations => Args); + end Make_Task_Create_Call; + + ------------------------------ + -- Next_Protected_Operation -- + ------------------------------ + + function Next_Protected_Operation (N : Node_Id) return Node_Id is + Next_Op : Node_Id; + + begin + Next_Op := Next (N); + + while Present (Next_Op) + and then Nkind (Next_Op) /= N_Subprogram_Body + and then Nkind (Next_Op) /= N_Entry_Body + loop + Next (Next_Op); + end loop; + + return Next_Op; + end Next_Protected_Operation; + + ---------------------- + -- Set_Discriminals -- + ---------------------- + + procedure Set_Discriminals + (Dec : Node_Id; + Op : Node_Id; + Loc : Source_Ptr) + is + D : Entity_Id; + Pdef : Entity_Id; + D_Minal : Entity_Id; + + begin + pragma Assert (Nkind (Dec) = N_Protected_Type_Declaration); + Pdef := Defining_Identifier (Dec); + + if Has_Discriminants (Pdef) then + D := First_Discriminant (Pdef); + + while Present (D) loop + D_Minal := + Make_Defining_Identifier (Sloc (D), + Chars => New_External_Name (Chars (D), 'D')); + + Set_Ekind (D_Minal, E_Constant); + Set_Etype (D_Minal, Etype (D)); + Set_Discriminal (D, D_Minal); + Set_Discriminal_Link (D_Minal, D); + + Next_Discriminant (D); + end loop; + end if; + end Set_Discriminals; + + ----------------- + -- Set_Privals -- + ----------------- + + procedure Set_Privals + (Dec : Node_Id; + Op : Node_Id; + Loc : Source_Ptr) + is + P_Decl : Node_Id; + P_Id : Entity_Id; + Priv : Entity_Id; + Def : Node_Id; + Body_Ent : Entity_Id; + Prec_Decl : constant Node_Id := + Parent (Corresponding_Record_Type + (Defining_Identifier (Dec))); + Prec_Def : constant Entity_Id := Type_Definition (Prec_Decl); + Obj_Decl : Node_Id; + P_Subtype : Entity_Id; + New_Decl : Entity_Id; + Assoc_L : Elist_Id := New_Elmt_List; + Op_Id : Entity_Id; + + begin + pragma Assert (Nkind (Dec) = N_Protected_Type_Declaration); + pragma Assert + (Nkind (Op) = N_Subprogram_Body or else Nkind (Op) = N_Entry_Body); + + Def := Protected_Definition (Dec); + + if Present (Private_Declarations (Def)) then + + P_Decl := First (Private_Declarations (Def)); + + while Present (P_Decl) loop + if Nkind (P_Decl) = N_Component_Declaration then + P_Id := Defining_Identifier (P_Decl); + Priv := + Make_Defining_Identifier (Loc, + New_External_Name (Chars (P_Id), 'P')); + + Set_Ekind (Priv, E_Variable); + Set_Etype (Priv, Etype (P_Id)); + Set_Scope (Priv, Scope (P_Id)); + Set_Esize (Priv, Esize (Etype (P_Id))); + Set_Alignment (Priv, Alignment (Etype (P_Id))); + + -- If the type of the component is an itype, we must + -- create a new itype for the corresponding prival in + -- each protected operation, to avoid scoping problems. + -- We create new itypes by copying the tree for the + -- component definition. + + if Is_Itype (Etype (P_Id)) then + Append_Elmt (P_Id, Assoc_L); + Append_Elmt (Priv, Assoc_L); + + if Nkind (Op) = N_Entry_Body then + Op_Id := Defining_Identifier (Op); + else + Op_Id := Defining_Unit_Name (Specification (Op)); + end if; + + New_Decl := New_Copy_Tree (P_Decl, Assoc_L, + New_Scope => Op_Id); + end if; + + Set_Protected_Operation (P_Id, Op); + Set_Prival (P_Id, Priv); + end if; + + Next (P_Decl); + end loop; + end if; + + -- There is one more implicit private declaration: the object + -- itself. A "prival" for this is attached to the protected + -- body defining identifier. + + Body_Ent := Corresponding_Body (Dec); + + Priv := + Make_Defining_Identifier (Sloc (Body_Ent), + Chars => New_External_Name (Chars (Body_Ent), 'R')); + + -- Set the Etype to the implicit subtype of Protection created when + -- the protected type declaration was expanded. This node will not + -- be analyzed until it is used as the defining identifier for the + -- renaming declaration in the protected operation body, and it will + -- be needed in the references expanded before that body is expanded. + -- Since the Protection field is aliased, set Is_Aliased as well. + + Obj_Decl := First (Component_Items (Component_List (Prec_Def))); + while Chars (Defining_Identifier (Obj_Decl)) /= Name_uObject loop + Next (Obj_Decl); + end loop; + + P_Subtype := Etype (Defining_Identifier (Obj_Decl)); + Set_Etype (Priv, P_Subtype); + Set_Is_Aliased (Priv); + Set_Object_Ref (Body_Ent, Priv); + + end Set_Privals; + + ---------------------------- + -- Update_Prival_Subtypes -- + ---------------------------- + + procedure Update_Prival_Subtypes (N : Node_Id) is + + function Process (N : Node_Id) return Traverse_Result; + -- Update the etype of occurrences of privals whose etype does not + -- match the current Etype of the prival entity itself. + + procedure Update_Array_Bounds (E : Entity_Id); + -- Itypes generated for array expressions may depend on the + -- determinants of the protected object, and need to be processed + -- separately because they are not attached to the tree. + + ------------- + -- Process -- + ------------- + + function Process (N : Node_Id) return Traverse_Result is + begin + if Is_Entity_Name (N) then + declare + E : Entity_Id := Entity (N); + + begin + if Present (E) + and then (Ekind (E) = E_Constant + or else Ekind (E) = E_Variable) + and then Nkind (Parent (E)) = N_Object_Renaming_Declaration + and then not Is_Scalar_Type (Etype (E)) + and then Etype (N) /= Etype (E) + then + Set_Etype (N, Etype (Entity (Original_Node (N)))); + + -- If the prefix has an actual subtype that is different + -- from the nominal one, update the types of the indices, + -- so that the proper constraints are applied. Do not + -- apply this transformation to a packed array, where the + -- index type is computed for a byte array and is different + -- from the source index. + + if Nkind (Parent (N)) = N_Indexed_Component + and then + not Is_Bit_Packed_Array (Etype (Prefix (Parent (N)))) + then + declare + Indx1 : Node_Id; + I_Typ : Node_Id; + + begin + Indx1 := First (Expressions (Parent (N))); + I_Typ := First_Index (Etype (N)); + + while Present (Indx1) and then Present (I_Typ) loop + + if not Is_Entity_Name (Indx1) then + Set_Etype (Indx1, Base_Type (Etype (I_Typ))); + end if; + + Next (Indx1); + Next_Index (I_Typ); + end loop; + end; + end if; + + elsif Present (E) + and then Ekind (E) = E_Constant + and then Present (Discriminal_Link (E)) + then + Set_Etype (N, Etype (E)); + end if; + end; + + return OK; + + elsif Nkind (N) = N_Defining_Identifier + or else Nkind (N) = N_Defining_Operator_Symbol + or else Nkind (N) = N_Defining_Character_Literal + then + return Skip; + + elsif Nkind (N) = N_String_Literal then + -- array type, but bounds are constant. + return OK; + + elsif Nkind (N) = N_Object_Declaration + and then Is_Itype (Etype (Defining_Identifier (N))) + and then Is_Array_Type (Etype (Defining_Identifier (N))) + then + Update_Array_Bounds (Etype (Defining_Identifier (N))); + return OK; + + else + if Nkind (N) in N_Has_Etype + and then Present (Etype (N)) + and then Is_Itype (Etype (N)) then + + if Is_Array_Type (Etype (N)) then + Update_Array_Bounds (Etype (N)); + + elsif Is_Scalar_Type (Etype (N)) then + Update_Prival_Subtypes (Type_Low_Bound (Etype (N))); + Update_Prival_Subtypes (Type_High_Bound (Etype (N))); + end if; + end if; + + return OK; + end if; + end Process; + + ------------------------- + -- Update_Array_Bounds -- + ------------------------- + + procedure Update_Array_Bounds (E : Entity_Id) is + Ind : Node_Id; + + begin + Ind := First_Index (E); + + while Present (Ind) loop + Update_Prival_Subtypes (Type_Low_Bound (Etype (Ind))); + Update_Prival_Subtypes (Type_High_Bound (Etype (Ind))); + Next_Index (Ind); + end loop; + end Update_Array_Bounds; + + procedure Traverse is new Traverse_Proc; + + -- Start of processsing for Update_Prival_Subtypes + + begin + Traverse (N); + end Update_Prival_Subtypes; + +end Exp_Ch9; |