1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2014, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Exp_Ch9; use Exp_Ch9;
33 with Elists; use Elists;
34 with Freeze; use Freeze;
35 with Layout; use Layout;
36 with Lib.Xref; use Lib.Xref;
37 with Namet; use Namet;
38 with Nlists; use Nlists;
39 with Nmake; use Nmake;
41 with Restrict; use Restrict;
42 with Rident; use Rident;
43 with Rtsfind; use Rtsfind;
45 with Sem_Aux; use Sem_Aux;
46 with Sem_Ch3; use Sem_Ch3;
47 with Sem_Ch5; use Sem_Ch5;
48 with Sem_Ch6; use Sem_Ch6;
49 with Sem_Ch8; use Sem_Ch8;
50 with Sem_Ch13; use Sem_Ch13;
51 with Sem_Eval; use Sem_Eval;
52 with Sem_Res; use Sem_Res;
53 with Sem_Type; use Sem_Type;
54 with Sem_Util; use Sem_Util;
55 with Sem_Warn; use Sem_Warn;
56 with Snames; use Snames;
57 with Stand; use Stand;
58 with Sinfo; use Sinfo;
60 with Targparm; use Targparm;
61 with Tbuild; use Tbuild;
62 with Uintp; use Uintp;
64 package body Sem_Ch9 is
66 -----------------------
67 -- Local Subprograms --
68 -----------------------
70 function Allows_Lock_Free_Implementation
72 Lock_Free_Given : Boolean := False) return Boolean;
73 -- This routine returns True iff N satisfies the following list of lock-
74 -- free restrictions for protected type declaration and protected body:
76 -- 1) Protected type declaration
77 -- May not contain entries
78 -- Protected subprogram declarations may not have non-elementary
82 -- Each protected subprogram body within N must satisfy:
83 -- May reference only one protected component
84 -- May not reference non-constant entities outside the protected
86 -- May not contain address representation items, allocators and
87 -- quantified expressions.
88 -- May not contain delay, goto, loop and procedure call
90 -- May not contain exported and imported entities
91 -- May not dereference access values
92 -- Function calls and attribute references must be static
94 -- If Lock_Free_Given is True, an error message is issued when False is
97 procedure Check_Max_Entries (D : Node_Id; R : All_Parameter_Restrictions);
98 -- Given either a protected definition or a task definition in D, check
99 -- the corresponding restriction parameter identifier R, and if it is set,
100 -- count the entries (checking the static requirement), and compare with
101 -- the given maximum.
103 procedure Check_Interfaces (N : Node_Id; T : Entity_Id);
104 -- N is an N_Protected_Type_Declaration or N_Task_Type_Declaration node.
105 -- Complete decoration of T and check legality of the covered interfaces.
107 procedure Check_Triggering_Statement
109 Error_Node : Node_Id;
110 Is_Dispatching : out Boolean);
111 -- Examine the triggering statement of a select statement, conditional or
112 -- timed entry call. If Trigger is a dispatching call, return its status
113 -- in Is_Dispatching and check whether the primitive belongs to a limited
114 -- interface. If it does not, emit an error at Error_Node.
116 function Find_Concurrent_Spec (Body_Id : Entity_Id) return Entity_Id;
117 -- Find entity in corresponding task or protected declaration. Use full
118 -- view if first declaration was for an incomplete type.
120 -------------------------------------
121 -- Allows_Lock_Free_Implementation --
122 -------------------------------------
124 function Allows_Lock_Free_Implementation
126 Lock_Free_Given : Boolean := False) return Boolean
129 -- Errors_Count is a count of errors detected by the compiler so far
130 -- when Lock_Free_Given is True.
133 pragma Assert (Nkind_In (N, N_Protected_Type_Declaration,
136 -- The lock-free implementation is currently enabled through a debug
137 -- flag. When Lock_Free_Given is True, an aspect Lock_Free forces the
138 -- lock-free implementation. In that case, the debug flag is not needed.
140 if not Lock_Free_Given and then not Debug_Flag_9 then
144 -- Get the number of errors detected by the compiler so far
146 if Lock_Free_Given then
147 Errors_Count := Serious_Errors_Detected;
150 -- Protected type declaration case
152 if Nkind (N) = N_Protected_Type_Declaration then
154 Pdef : constant Node_Id := Protected_Definition (N);
155 Priv_Decls : constant List_Id := Private_Declarations (Pdef);
156 Vis_Decls : constant List_Id := Visible_Declarations (Pdef);
160 -- Examine the visible and the private declarations
162 Decl := First (Vis_Decls);
163 while Present (Decl) loop
165 -- Entries and entry families are not allowed by the lock-free
168 if Nkind (Decl) = N_Entry_Declaration then
169 if Lock_Free_Given then
171 ("entry not allowed when Lock_Free given", Decl);
176 -- Non-elementary parameters in protected procedure are not
177 -- allowed by the lock-free restrictions.
179 elsif Nkind (Decl) = N_Subprogram_Declaration
181 Nkind (Specification (Decl)) = N_Procedure_Specification
183 Present (Parameter_Specifications (Specification (Decl)))
186 Par_Specs : constant List_Id :=
187 Parameter_Specifications
188 (Specification (Decl));
193 Par := First (Par_Specs);
194 while Present (Par) loop
195 if not Is_Elementary_Type
196 (Etype (Defining_Identifier (Par)))
198 if Lock_Free_Given then
200 ("non-elementary parameter& not allowed "
201 & "when Lock_Free given",
202 Par, Defining_Identifier (Par));
213 -- Examine private declarations after visible declarations
216 and then List_Containing (Decl) = Vis_Decls
218 Decl := First (Priv_Decls);
225 -- Protected body case
228 Protected_Body_Case : declare
229 Decls : constant List_Id := Declarations (N);
230 Pid : constant Entity_Id := Corresponding_Spec (N);
231 Prot_Typ_Decl : constant Node_Id := Parent (Pid);
232 Prot_Def : constant Node_Id :=
233 Protected_Definition (Prot_Typ_Decl);
234 Priv_Decls : constant List_Id :=
235 Private_Declarations (Prot_Def);
238 function Satisfies_Lock_Free_Requirements
239 (Sub_Body : Node_Id) return Boolean;
240 -- Return True if protected subprogram body Sub_Body satisfies all
241 -- requirements of a lock-free implementation.
243 --------------------------------------
244 -- Satisfies_Lock_Free_Requirements --
245 --------------------------------------
247 function Satisfies_Lock_Free_Requirements
248 (Sub_Body : Node_Id) return Boolean
250 Is_Procedure : constant Boolean :=
251 Ekind (Corresponding_Spec (Sub_Body)) =
253 -- Indicates if Sub_Body is a procedure body
255 Comp : Entity_Id := Empty;
256 -- Track the current component which the body references
259 -- Errors_Count is a count of errors detected by the compiler
260 -- so far when Lock_Free_Given is True.
262 function Check_Node (N : Node_Id) return Traverse_Result;
263 -- Check that node N meets the lock free restrictions
269 function Check_Node (N : Node_Id) return Traverse_Result is
270 Kind : constant Node_Kind := Nkind (N);
272 -- The following function belongs in sem_eval ???
274 function Is_Static_Function (Attr : Node_Id) return Boolean;
275 -- Given an attribute reference node Attr, return True if
276 -- Attr denotes a static function according to the rules in
279 ------------------------
280 -- Is_Static_Function --
281 ------------------------
283 function Is_Static_Function
284 (Attr : Node_Id) return Boolean
289 pragma Assert (Nkind (Attr) = N_Attribute_Reference);
291 case Attribute_Name (Attr) is
298 Name_Wide_Wide_Value =>
300 -- A language-defined attribute denotes a static
301 -- function if the prefix denotes a static scalar
302 -- subtype, and if the parameter and result types
303 -- are scalar (RM 4.9 (22)).
305 if Is_Scalar_Type (Etype (Attr))
306 and then Is_Scalar_Type (Etype (Prefix (Attr)))
307 and then Is_Static_Subtype (Etype (Prefix (Attr)))
309 Para := First (Expressions (Attr));
311 while Present (Para) loop
312 if not Is_Scalar_Type (Etype (Para)) then
325 when others => return False;
327 end Is_Static_Function;
329 -- Start of processing for Check_Node
333 -- Allocators restricted
335 if Kind = N_Allocator then
336 if Lock_Free_Given then
337 Error_Msg_N ("allocator not allowed", N);
343 -- Aspects Address, Export and Import restricted
345 elsif Kind = N_Aspect_Specification then
347 Asp_Name : constant Name_Id :=
348 Chars (Identifier (N));
349 Asp_Id : constant Aspect_Id :=
350 Get_Aspect_Id (Asp_Name);
353 if Asp_Id = Aspect_Address or else
354 Asp_Id = Aspect_Export or else
355 Asp_Id = Aspect_Import
357 Error_Msg_Name_1 := Asp_Name;
359 if Lock_Free_Given then
360 Error_Msg_N ("aspect% not allowed", N);
368 -- Address attribute definition clause restricted
370 elsif Kind = N_Attribute_Definition_Clause
371 and then Get_Attribute_Id (Chars (N)) =
374 Error_Msg_Name_1 := Chars (N);
376 if Lock_Free_Given then
377 if From_Aspect_Specification (N) then
378 Error_Msg_N ("aspect% not allowed", N);
380 Error_Msg_N ("% clause not allowed", N);
388 -- Non-static Attribute references that don't denote a
389 -- static function restricted.
391 elsif Kind = N_Attribute_Reference
392 and then not Is_Static_Expression (N)
393 and then not Is_Static_Function (N)
395 if Lock_Free_Given then
397 ("non-static attribute reference not allowed", N);
403 -- Delay statements restricted
405 elsif Kind in N_Delay_Statement then
406 if Lock_Free_Given then
407 Error_Msg_N ("delay not allowed", N);
413 -- Dereferences of access values restricted
415 elsif Kind = N_Explicit_Dereference
416 or else (Kind = N_Selected_Component
417 and then Is_Access_Type (Etype (Prefix (N))))
419 if Lock_Free_Given then
421 ("dereference of access value not allowed", N);
427 -- Non-static function calls restricted
429 elsif Kind = N_Function_Call
430 and then not Is_Static_Expression (N)
432 if Lock_Free_Given then
434 ("non-static function call not allowed", N);
440 -- Goto statements restricted
442 elsif Kind = N_Goto_Statement then
443 if Lock_Free_Given then
444 Error_Msg_N ("goto statement not allowed", N);
452 elsif Kind = N_Identifier
453 and then Present (Entity (N))
456 Id : constant Entity_Id := Entity (N);
457 Sub_Id : constant Entity_Id :=
458 Corresponding_Spec (Sub_Body);
461 -- Prohibit references to non-constant entities
462 -- outside the protected subprogram scope.
464 if Ekind (Id) in Assignable_Kind
466 Scope_Within_Or_Same (Scope (Id), Sub_Id)
470 Protected_Body_Subprogram (Sub_Id))
472 if Lock_Free_Given then
474 ("reference to global variable& not " &
483 -- Loop statements restricted
485 elsif Kind = N_Loop_Statement then
486 if Lock_Free_Given then
487 Error_Msg_N ("loop not allowed", N);
493 -- Pragmas Export and Import restricted
495 elsif Kind = N_Pragma then
497 Prag_Name : constant Name_Id := Pragma_Name (N);
498 Prag_Id : constant Pragma_Id :=
499 Get_Pragma_Id (Prag_Name);
502 if Prag_Id = Pragma_Export
503 or else Prag_Id = Pragma_Import
505 Error_Msg_Name_1 := Prag_Name;
507 if Lock_Free_Given then
508 if From_Aspect_Specification (N) then
509 Error_Msg_N ("aspect% not allowed", N);
511 Error_Msg_N ("pragma% not allowed", N);
521 -- Procedure call statements restricted
523 elsif Kind = N_Procedure_Call_Statement then
524 if Lock_Free_Given then
525 Error_Msg_N ("procedure call not allowed", N);
531 -- Quantified expression restricted. Note that we have
532 -- to check the original node as well, since at this
533 -- stage, it may have been rewritten.
535 elsif Kind = N_Quantified_Expression
537 Nkind (Original_Node (N)) = N_Quantified_Expression
539 if Lock_Free_Given then
541 ("quantified expression not allowed", N);
549 -- A protected subprogram (function or procedure) may
550 -- reference only one component of the protected type, plus
551 -- the type of the component must support atomic operation.
553 if Kind = N_Identifier
554 and then Present (Entity (N))
557 Id : constant Entity_Id := Entity (N);
559 Comp_Id : Entity_Id := Empty;
560 Comp_Type : Entity_Id;
563 if Ekind (Id) = E_Component then
566 elsif Ekind_In (Id, E_Constant, E_Variable)
567 and then Present (Prival_Link (Id))
569 Comp_Id := Prival_Link (Id);
572 if Present (Comp_Id) then
573 Comp_Decl := Parent (Comp_Id);
574 Comp_Type := Etype (Comp_Id);
576 if Nkind (Comp_Decl) = N_Component_Declaration
577 and then Is_List_Member (Comp_Decl)
578 and then List_Containing (Comp_Decl) = Priv_Decls
580 -- Skip generic types since, in that case, we
581 -- will not build a body anyway (in the generic
582 -- template), and the size in the template may
583 -- have a fake value.
585 if not Is_Generic_Type (Comp_Type) then
587 -- Make sure the protected component type has
588 -- size and alignment fields set at this
589 -- point whenever this is possible.
591 Layout_Type (Comp_Type);
594 Support_Atomic_Primitives (Comp_Type)
596 if Lock_Free_Given then
598 ("type of& must support atomic " &
608 -- Check if another protected component has
609 -- already been accessed by the subprogram body.
614 elsif Comp /= Comp_Id then
615 if Lock_Free_Given then
617 ("only one protected component allowed",
632 function Check_All_Nodes is new Traverse_Func (Check_Node);
634 -- Start of processing for Satisfies_Lock_Free_Requirements
637 -- Get the number of errors detected by the compiler so far
639 if Lock_Free_Given then
640 Errors_Count := Serious_Errors_Detected;
643 if Check_All_Nodes (Sub_Body) = OK
644 and then (not Lock_Free_Given
645 or else Errors_Count = Serious_Errors_Detected)
647 -- Establish a relation between the subprogram body and the
648 -- unique protected component it references.
650 if Present (Comp) then
651 Lock_Free_Subprogram_Table.Append
652 (Lock_Free_Subprogram'(Sub_Body, Comp));
659 end Satisfies_Lock_Free_Requirements;
661 -- Start of processing for Protected_Body_Case
664 Decl := First (Decls);
665 while Present (Decl) loop
666 if Nkind (Decl) = N_Subprogram_Body
667 and then not Satisfies_Lock_Free_Requirements (Decl)
669 if Lock_Free_Given then
671 ("illegal body when Lock_Free given", Decl);
679 end Protected_Body_Case;
682 -- When Lock_Free is given, check if no error has been detected during
686 and then Errors_Count /= Serious_Errors_Detected
692 end Allows_Lock_Free_Implementation;
694 -----------------------------
695 -- Analyze_Abort_Statement --
696 -----------------------------
698 procedure Analyze_Abort_Statement (N : Node_Id) is
702 Tasking_Used := True;
703 Check_SPARK_Restriction ("abort statement is not allowed", N);
705 T_Name := First (Names (N));
706 while Present (T_Name) loop
709 if Is_Task_Type (Etype (T_Name))
710 or else (Ada_Version >= Ada_2005
711 and then Ekind (Etype (T_Name)) = E_Class_Wide_Type
712 and then Is_Interface (Etype (T_Name))
713 and then Is_Task_Interface (Etype (T_Name)))
717 if Ada_Version >= Ada_2005 then
718 Error_Msg_N ("expect task name or task interface class-wide "
719 & "object for ABORT", T_Name);
721 Error_Msg_N ("expect task name for ABORT", T_Name);
730 Check_Restriction (No_Abort_Statements, N);
731 Check_Potentially_Blocking_Operation (N);
732 end Analyze_Abort_Statement;
734 --------------------------------
735 -- Analyze_Accept_Alternative --
736 --------------------------------
738 procedure Analyze_Accept_Alternative (N : Node_Id) is
740 Tasking_Used := True;
742 if Present (Pragmas_Before (N)) then
743 Analyze_List (Pragmas_Before (N));
746 if Present (Condition (N)) then
747 Analyze_And_Resolve (Condition (N), Any_Boolean);
750 Analyze (Accept_Statement (N));
752 if Is_Non_Empty_List (Statements (N)) then
753 Analyze_Statements (Statements (N));
755 end Analyze_Accept_Alternative;
757 ------------------------------
758 -- Analyze_Accept_Statement --
759 ------------------------------
761 procedure Analyze_Accept_Statement (N : Node_Id) is
762 Nam : constant Entity_Id := Entry_Direct_Name (N);
763 Formals : constant List_Id := Parameter_Specifications (N);
764 Index : constant Node_Id := Entry_Index (N);
765 Stats : constant Node_Id := Handled_Statement_Sequence (N);
766 Accept_Id : Entity_Id;
767 Entry_Nam : Entity_Id;
770 Task_Nam : Entity_Id;
773 Tasking_Used := True;
774 Check_SPARK_Restriction ("accept statement is not allowed", N);
776 -- Entry name is initialized to Any_Id. It should get reset to the
777 -- matching entry entity. An error is signalled if it is not reset.
781 for J in reverse 0 .. Scope_Stack.Last loop
782 Task_Nam := Scope_Stack.Table (J).Entity;
783 exit when Ekind (Etype (Task_Nam)) = E_Task_Type;
784 Kind := Ekind (Task_Nam);
786 if Kind /= E_Block and then Kind /= E_Loop
787 and then not Is_Entry (Task_Nam)
789 Error_Msg_N ("enclosing body of accept must be a task", N);
794 if Ekind (Etype (Task_Nam)) /= E_Task_Type then
795 Error_Msg_N ("invalid context for accept statement", N);
799 -- In order to process the parameters, we create a defining identifier
800 -- that can be used as the name of the scope. The name of the accept
801 -- statement itself is not a defining identifier, and we cannot use
802 -- its name directly because the task may have any number of accept
803 -- statements for the same entry.
805 if Present (Index) then
806 Accept_Id := New_Internal_Entity
807 (E_Entry_Family, Current_Scope, Sloc (N), 'E');
809 Accept_Id := New_Internal_Entity
810 (E_Entry, Current_Scope, Sloc (N), 'E');
813 Set_Etype (Accept_Id, Standard_Void_Type);
814 Set_Accept_Address (Accept_Id, New_Elmt_List);
816 if Present (Formals) then
817 Push_Scope (Accept_Id);
818 Process_Formals (Formals, N);
819 Create_Extra_Formals (Accept_Id);
823 -- We set the default expressions processed flag because we don't need
824 -- default expression functions. This is really more like body entity
825 -- than a spec entity anyway.
827 Set_Default_Expressions_Processed (Accept_Id);
829 E := First_Entity (Etype (Task_Nam));
830 while Present (E) loop
831 if Chars (E) = Chars (Nam)
832 and then (Ekind (E) = Ekind (Accept_Id))
833 and then Type_Conformant (Accept_Id, E)
842 if Entry_Nam = Any_Id then
843 Error_Msg_N ("no entry declaration matches accept statement", N);
846 Set_Entity (Nam, Entry_Nam);
847 Generate_Reference (Entry_Nam, Nam, 'b', Set_Ref => False);
848 Style.Check_Identifier (Nam, Entry_Nam);
851 -- Verify that the entry is not hidden by a procedure declared in the
852 -- current block (pathological but possible).
854 if Current_Scope /= Task_Nam then
859 E1 := First_Entity (Current_Scope);
860 while Present (E1) loop
861 if Ekind (E1) = E_Procedure
862 and then Chars (E1) = Chars (Entry_Nam)
863 and then Type_Conformant (E1, Entry_Nam)
865 Error_Msg_N ("entry name is not visible", N);
873 Set_Convention (Accept_Id, Convention (Entry_Nam));
874 Check_Fully_Conformant (Accept_Id, Entry_Nam, N);
876 for J in reverse 0 .. Scope_Stack.Last loop
877 exit when Task_Nam = Scope_Stack.Table (J).Entity;
879 if Entry_Nam = Scope_Stack.Table (J).Entity then
880 Error_Msg_N ("duplicate accept statement for same entry", N);
890 when N_Task_Body | N_Compilation_Unit =>
892 when N_Asynchronous_Select =>
893 Error_Msg_N ("accept statements are not allowed within" &
894 " an asynchronous select inner" &
895 " to the enclosing task body", N);
903 if Ekind (E) = E_Entry_Family then
905 Error_Msg_N ("missing entry index in accept for entry family", N);
907 Analyze_And_Resolve (Index, Entry_Index_Type (E));
908 Apply_Range_Check (Index, Entry_Index_Type (E));
911 elsif Present (Index) then
912 Error_Msg_N ("invalid entry index in accept for simple entry", N);
915 -- If label declarations present, analyze them. They are declared in the
916 -- enclosing task, but their enclosing scope is the entry itself, so
917 -- that goto's to the label are recognized as local to the accept.
919 if Present (Declarations (N)) then
925 Decl := First (Declarations (N));
926 while Present (Decl) loop
930 (Nkind (Decl) = N_Implicit_Label_Declaration);
932 Id := Defining_Identifier (Decl);
933 Set_Enclosing_Scope (Id, Entry_Nam);
939 -- If statements are present, they must be analyzed in the context of
940 -- the entry, so that references to formals are correctly resolved. We
941 -- also have to add the declarations that are required by the expansion
942 -- of the accept statement in this case if expansion active.
944 -- In the case of a select alternative of a selective accept, the
945 -- expander references the address declaration even if there is no
948 -- We also need to create the renaming declarations for the local
949 -- variables that will replace references to the formals within the
952 Exp_Ch9.Expand_Accept_Declarations (N, Entry_Nam);
954 -- Set Never_Set_In_Source and clear Is_True_Constant/Current_Value
955 -- fields on all entry formals (this loop ignores all other entities).
956 -- Reset Referenced, Referenced_As_xxx and Has_Pragma_Unreferenced as
957 -- well, so that we can post accurate warnings on each accept statement
958 -- for the same entry.
960 E := First_Entity (Entry_Nam);
961 while Present (E) loop
962 if Is_Formal (E) then
963 Set_Never_Set_In_Source (E, True);
964 Set_Is_True_Constant (E, False);
965 Set_Current_Value (E, Empty);
966 Set_Referenced (E, False);
967 Set_Referenced_As_LHS (E, False);
968 Set_Referenced_As_Out_Parameter (E, False);
969 Set_Has_Pragma_Unreferenced (E, False);
975 -- Analyze statements if present
977 if Present (Stats) then
978 Push_Scope (Entry_Nam);
979 Install_Declarations (Entry_Nam);
981 Set_Actual_Subtypes (N, Current_Scope);
984 Process_End_Label (Handled_Statement_Sequence (N), 't', Entry_Nam);
988 -- Some warning checks
990 Check_Potentially_Blocking_Operation (N);
991 Check_References (Entry_Nam, N);
992 Set_Entry_Accepted (Entry_Nam);
993 end Analyze_Accept_Statement;
995 ---------------------------------
996 -- Analyze_Asynchronous_Select --
997 ---------------------------------
999 procedure Analyze_Asynchronous_Select (N : Node_Id) is
1000 Is_Disp_Select : Boolean := False;
1004 Tasking_Used := True;
1005 Check_SPARK_Restriction ("select statement is not allowed", N);
1006 Check_Restriction (Max_Asynchronous_Select_Nesting, N);
1007 Check_Restriction (No_Select_Statements, N);
1009 if Ada_Version >= Ada_2005 then
1010 Trigger := Triggering_Statement (Triggering_Alternative (N));
1014 -- Ada 2005 (AI-345): Check for a potential dispatching select
1016 Check_Triggering_Statement (Trigger, N, Is_Disp_Select);
1019 -- Ada 2005 (AI-345): The expansion of the dispatching asynchronous
1020 -- select will have to duplicate the triggering statements. Postpone
1021 -- the analysis of the statements till expansion. Analyze only if the
1022 -- expander is disabled in order to catch any semantic errors.
1024 if Is_Disp_Select then
1025 if not Expander_Active then
1026 Analyze_Statements (Statements (Abortable_Part (N)));
1027 Analyze (Triggering_Alternative (N));
1030 -- Analyze the statements. We analyze statements in the abortable part,
1031 -- because this is the section that is executed first, and that way our
1032 -- remembering of saved values and checks is accurate.
1035 Analyze_Statements (Statements (Abortable_Part (N)));
1036 Analyze (Triggering_Alternative (N));
1038 end Analyze_Asynchronous_Select;
1040 ------------------------------------
1041 -- Analyze_Conditional_Entry_Call --
1042 ------------------------------------
1044 procedure Analyze_Conditional_Entry_Call (N : Node_Id) is
1045 Trigger : constant Node_Id :=
1046 Entry_Call_Statement (Entry_Call_Alternative (N));
1047 Is_Disp_Select : Boolean := False;
1050 Tasking_Used := True;
1051 Check_SPARK_Restriction ("select statement is not allowed", N);
1052 Check_Restriction (No_Select_Statements, N);
1054 -- Ada 2005 (AI-345): The trigger may be a dispatching call
1056 if Ada_Version >= Ada_2005 then
1058 Check_Triggering_Statement (Trigger, N, Is_Disp_Select);
1061 if List_Length (Else_Statements (N)) = 1
1062 and then Nkind (First (Else_Statements (N))) in N_Delay_Statement
1065 ("suspicious form of conditional entry call??!", N);
1067 ("\`SELECT OR` may be intended rather than `SELECT ELSE`??!", N);
1070 -- Postpone the analysis of the statements till expansion. Analyze only
1071 -- if the expander is disabled in order to catch any semantic errors.
1073 if Is_Disp_Select then
1074 if not Expander_Active then
1075 Analyze (Entry_Call_Alternative (N));
1076 Analyze_Statements (Else_Statements (N));
1079 -- Regular select analysis
1082 Analyze (Entry_Call_Alternative (N));
1083 Analyze_Statements (Else_Statements (N));
1085 end Analyze_Conditional_Entry_Call;
1087 --------------------------------
1088 -- Analyze_Delay_Alternative --
1089 --------------------------------
1091 procedure Analyze_Delay_Alternative (N : Node_Id) is
1096 Tasking_Used := True;
1097 Check_Restriction (No_Delay, N);
1099 if Present (Pragmas_Before (N)) then
1100 Analyze_List (Pragmas_Before (N));
1103 if Nkind_In (Parent (N), N_Selective_Accept, N_Timed_Entry_Call) then
1104 Expr := Expression (Delay_Statement (N));
1106 -- Defer full analysis until the statement is expanded, to insure
1107 -- that generated code does not move past the guard. The delay
1108 -- expression is only evaluated if the guard is open.
1110 if Nkind (Delay_Statement (N)) = N_Delay_Relative_Statement then
1111 Preanalyze_And_Resolve (Expr, Standard_Duration);
1113 Preanalyze_And_Resolve (Expr);
1116 Typ := First_Subtype (Etype (Expr));
1118 if Nkind (Delay_Statement (N)) = N_Delay_Until_Statement
1119 and then not Is_RTE (Typ, RO_CA_Time)
1120 and then not Is_RTE (Typ, RO_RT_Time)
1122 Error_Msg_N ("expect Time types for `DELAY UNTIL`", Expr);
1125 Check_Restriction (No_Fixed_Point, Expr);
1128 Analyze (Delay_Statement (N));
1131 if Present (Condition (N)) then
1132 Analyze_And_Resolve (Condition (N), Any_Boolean);
1135 if Is_Non_Empty_List (Statements (N)) then
1136 Analyze_Statements (Statements (N));
1138 end Analyze_Delay_Alternative;
1140 ----------------------------
1141 -- Analyze_Delay_Relative --
1142 ----------------------------
1144 procedure Analyze_Delay_Relative (N : Node_Id) is
1145 E : constant Node_Id := Expression (N);
1147 Tasking_Used := True;
1148 Check_SPARK_Restriction ("delay statement is not allowed", N);
1149 Check_Restriction (No_Relative_Delay, N);
1150 Check_Restriction (No_Delay, N);
1151 Check_Potentially_Blocking_Operation (N);
1152 Analyze_And_Resolve (E, Standard_Duration);
1153 Check_Restriction (No_Fixed_Point, E);
1154 end Analyze_Delay_Relative;
1156 -------------------------
1157 -- Analyze_Delay_Until --
1158 -------------------------
1160 procedure Analyze_Delay_Until (N : Node_Id) is
1161 E : constant Node_Id := Expression (N);
1165 Tasking_Used := True;
1166 Check_SPARK_Restriction ("delay statement is not allowed", N);
1167 Check_Restriction (No_Delay, N);
1168 Check_Potentially_Blocking_Operation (N);
1170 Typ := First_Subtype (Etype (E));
1172 if not Is_RTE (Typ, RO_CA_Time) and then
1173 not Is_RTE (Typ, RO_RT_Time)
1175 Error_Msg_N ("expect Time types for `DELAY UNTIL`", E);
1177 end Analyze_Delay_Until;
1179 ------------------------
1180 -- Analyze_Entry_Body --
1181 ------------------------
1183 procedure Analyze_Entry_Body (N : Node_Id) is
1184 Id : constant Entity_Id := Defining_Identifier (N);
1185 Decls : constant List_Id := Declarations (N);
1186 Stats : constant Node_Id := Handled_Statement_Sequence (N);
1187 Formals : constant Node_Id := Entry_Body_Formal_Part (N);
1188 P_Type : constant Entity_Id := Current_Scope;
1190 Entry_Name : Entity_Id;
1193 Tasking_Used := True;
1195 -- Entry_Name is initialized to Any_Id. It should get reset to the
1196 -- matching entry entity. An error is signalled if it is not reset
1198 Entry_Name := Any_Id;
1202 if Present (Entry_Index_Specification (Formals)) then
1203 Set_Ekind (Id, E_Entry_Family);
1205 Set_Ekind (Id, E_Entry);
1208 Set_Scope (Id, Current_Scope);
1209 Set_Etype (Id, Standard_Void_Type);
1210 Set_Accept_Address (Id, New_Elmt_List);
1212 E := First_Entity (P_Type);
1213 while Present (E) loop
1214 if Chars (E) = Chars (Id)
1215 and then (Ekind (E) = Ekind (Id))
1216 and then Type_Conformant (Id, E)
1219 Set_Convention (Id, Convention (E));
1220 Set_Corresponding_Body (Parent (Entry_Name), Id);
1221 Check_Fully_Conformant (Id, E, N);
1223 if Ekind (Id) = E_Entry_Family then
1224 if not Fully_Conformant_Discrete_Subtypes (
1225 Discrete_Subtype_Definition (Parent (E)),
1226 Discrete_Subtype_Definition
1227 (Entry_Index_Specification (Formals)))
1230 ("index not fully conformant with previous declaration",
1231 Discrete_Subtype_Definition
1232 (Entry_Index_Specification (Formals)));
1235 -- The elaboration of the entry body does not recompute the
1236 -- bounds of the index, which may have side effects. Inherit
1237 -- the bounds from the entry declaration. This is critical
1238 -- if the entry has a per-object constraint. If a bound is
1239 -- given by a discriminant, it must be reanalyzed in order
1240 -- to capture the discriminal of the current entry, rather
1241 -- than that of the protected type.
1244 Index_Spec : constant Node_Id :=
1245 Entry_Index_Specification (Formals);
1247 Def : constant Node_Id :=
1249 (Discrete_Subtype_Definition (Parent (E)));
1254 (Discrete_Subtype_Definition (Index_Spec))) = N_Range
1256 Set_Etype (Def, Empty);
1257 Set_Analyzed (Def, False);
1259 -- Keep the original subtree to ensure a properly
1260 -- formed tree (e.g. for ASIS use).
1263 (Discrete_Subtype_Definition (Index_Spec), Def);
1265 Set_Analyzed (Low_Bound (Def), False);
1266 Set_Analyzed (High_Bound (Def), False);
1268 if Denotes_Discriminant (Low_Bound (Def)) then
1269 Set_Entity (Low_Bound (Def), Empty);
1272 if Denotes_Discriminant (High_Bound (Def)) then
1273 Set_Entity (High_Bound (Def), Empty);
1277 Make_Index (Def, Index_Spec);
1279 (Defining_Identifier (Index_Spec), Etype (Def));
1291 if Entry_Name = Any_Id then
1292 Error_Msg_N ("no entry declaration matches entry body", N);
1295 elsif Has_Completion (Entry_Name) then
1296 Error_Msg_N ("duplicate entry body", N);
1300 Set_Has_Completion (Entry_Name);
1301 Generate_Reference (Entry_Name, Id, 'b', Set_Ref => False);
1302 Style.Check_Identifier (Id, Entry_Name);
1305 Exp_Ch9.Expand_Entry_Barrier (N, Entry_Name);
1306 Push_Scope (Entry_Name);
1308 Install_Declarations (Entry_Name);
1309 Set_Actual_Subtypes (N, Current_Scope);
1311 -- The entity for the protected subprogram corresponding to the entry
1312 -- has been created. We retain the name of this entity in the entry
1313 -- body, for use when the corresponding subprogram body is created.
1314 -- Note that entry bodies have no corresponding_spec, and there is no
1315 -- easy link back in the tree between the entry body and the entity for
1316 -- the entry itself, which is why we must propagate some attributes
1317 -- explicitly from spec to body.
1319 Set_Protected_Body_Subprogram
1320 (Id, Protected_Body_Subprogram (Entry_Name));
1322 Set_Entry_Parameters_Type
1323 (Id, Entry_Parameters_Type (Entry_Name));
1325 -- Add a declaration for the Protection object, renaming declarations
1326 -- for the discriminals and privals and finally a declaration for the
1327 -- entry family index (if applicable).
1330 and then Is_Protected_Type (P_Type)
1332 Install_Private_Data_Declarations
1333 (Sloc (N), Entry_Name, P_Type, N, Decls);
1336 if Present (Decls) then
1337 Analyze_Declarations (Decls);
1338 Inspect_Deferred_Constant_Completion (Decls);
1341 if Present (Stats) then
1345 -- Check for unreferenced variables etc. Before the Check_References
1346 -- call, we transfer Never_Set_In_Source and Referenced flags from
1347 -- parameters in the spec to the corresponding entities in the body,
1348 -- since we want the warnings on the body entities. Note that we do not
1349 -- have to transfer Referenced_As_LHS, since that flag can only be set
1350 -- for simple variables, but we include Has_Pragma_Unreferenced,
1351 -- which may have been specified for a formal in the body.
1353 -- At the same time, we set the flags on the spec entities to suppress
1354 -- any warnings on the spec formals, since we also scan the spec.
1355 -- Finally, we propagate the Entry_Component attribute to the body
1356 -- formals, for use in the renaming declarations created later for the
1357 -- formals (see exp_ch9.Add_Formal_Renamings).
1364 E1 := First_Entity (Entry_Name);
1365 while Present (E1) loop
1366 E2 := First_Entity (Id);
1367 while Present (E2) loop
1368 exit when Chars (E1) = Chars (E2);
1372 -- If no matching body entity, then we already had a detected
1373 -- error of some kind, so just don't worry about these warnings.
1379 if Ekind (E1) = E_Out_Parameter then
1380 Set_Never_Set_In_Source (E2, Never_Set_In_Source (E1));
1381 Set_Never_Set_In_Source (E1, False);
1384 Set_Referenced (E2, Referenced (E1));
1385 Set_Referenced (E1);
1386 Set_Has_Pragma_Unreferenced (E2, Has_Pragma_Unreferenced (E1));
1387 Set_Entry_Component (E2, Entry_Component (E1));
1393 Check_References (Id);
1396 -- We still need to check references for the spec, since objects
1397 -- declared in the body are chained (in the First_Entity sense) to
1398 -- the spec rather than the body in the case of entries.
1400 Check_References (Entry_Name);
1402 -- Process the end label, and terminate the scope
1404 Process_End_Label (Handled_Statement_Sequence (N), 't', Entry_Name);
1407 -- If this is an entry family, remove the loop created to provide
1408 -- a scope for the entry index.
1410 if Ekind (Id) = E_Entry_Family
1411 and then Present (Entry_Index_Specification (Formals))
1415 end Analyze_Entry_Body;
1417 ------------------------------------
1418 -- Analyze_Entry_Body_Formal_Part --
1419 ------------------------------------
1421 procedure Analyze_Entry_Body_Formal_Part (N : Node_Id) is
1422 Id : constant Entity_Id := Defining_Identifier (Parent (N));
1423 Index : constant Node_Id := Entry_Index_Specification (N);
1424 Formals : constant List_Id := Parameter_Specifications (N);
1427 Tasking_Used := True;
1429 if Present (Index) then
1432 -- The entry index functions like a loop variable, thus it is known
1433 -- to have a valid value.
1435 Set_Is_Known_Valid (Defining_Identifier (Index));
1438 if Present (Formals) then
1439 Set_Scope (Id, Current_Scope);
1441 Process_Formals (Formals, Parent (N));
1444 end Analyze_Entry_Body_Formal_Part;
1446 ------------------------------------
1447 -- Analyze_Entry_Call_Alternative --
1448 ------------------------------------
1450 procedure Analyze_Entry_Call_Alternative (N : Node_Id) is
1451 Call : constant Node_Id := Entry_Call_Statement (N);
1454 Tasking_Used := True;
1455 Check_SPARK_Restriction ("entry call is not allowed", N);
1457 if Present (Pragmas_Before (N)) then
1458 Analyze_List (Pragmas_Before (N));
1461 if Nkind (Call) = N_Attribute_Reference then
1463 -- Possibly a stream attribute, but definitely illegal. Other
1464 -- illegalities, such as procedure calls, are diagnosed after
1467 Error_Msg_N ("entry call alternative requires an entry call", Call);
1473 -- An indirect call in this context is illegal. A procedure call that
1474 -- does not involve a renaming of an entry is illegal as well, but this
1475 -- and other semantic errors are caught during resolution.
1477 if Nkind (Call) = N_Explicit_Dereference then
1479 ("entry call or dispatching primitive of interface required ", N);
1482 if Is_Non_Empty_List (Statements (N)) then
1483 Analyze_Statements (Statements (N));
1485 end Analyze_Entry_Call_Alternative;
1487 -------------------------------
1488 -- Analyze_Entry_Declaration --
1489 -------------------------------
1491 procedure Analyze_Entry_Declaration (N : Node_Id) is
1492 D_Sdef : constant Node_Id := Discrete_Subtype_Definition (N);
1493 Def_Id : constant Entity_Id := Defining_Identifier (N);
1494 Formals : constant List_Id := Parameter_Specifications (N);
1497 Generate_Definition (Def_Id);
1498 Set_Contract (Def_Id, Make_Contract (Sloc (Def_Id)));
1499 Tasking_Used := True;
1501 -- Case of no discrete subtype definition
1504 Set_Ekind (Def_Id, E_Entry);
1506 -- Processing for discrete subtype definition present
1509 Enter_Name (Def_Id);
1510 Set_Ekind (Def_Id, E_Entry_Family);
1512 Make_Index (D_Sdef, N, Def_Id);
1514 -- Check subtype with predicate in entry family
1516 Bad_Predicated_Subtype_Use
1517 ("subtype& has predicate, not allowed in entry family",
1518 D_Sdef, Etype (D_Sdef));
1520 -- Check entry family static bounds outside allowed limits
1522 -- Note: originally this check was not performed here, but in that
1523 -- case the check happens deep in the expander, and the message is
1524 -- posted at the wrong location, and omitted in -gnatc mode.
1525 -- If the type of the entry index is a generic formal, no check
1526 -- is possible. In an instance, the check is not static and a run-
1527 -- time exception will be raised if the bounds are unreasonable.
1530 PEI : constant Entity_Id := RTE (RE_Protected_Entry_Index);
1531 LB : constant Uint := Expr_Value (Type_Low_Bound (PEI));
1532 UB : constant Uint := Expr_Value (Type_High_Bound (PEI));
1539 -- No bounds checking if the type is generic or if previous error.
1540 -- In an instance the check is dynamic.
1542 if Is_Generic_Type (Etype (D_Sdef))
1544 or else Error_Posted (D_Sdef)
1548 elsif Nkind (D_Sdef) = N_Range then
1549 LBR := Low_Bound (D_Sdef);
1551 elsif Is_Entity_Name (D_Sdef)
1552 and then Is_Type (Entity (D_Sdef))
1554 LBR := Type_Low_Bound (Entity (D_Sdef));
1560 if Is_Static_Expression (LBR)
1561 and then Expr_Value (LBR) < LB
1563 Error_Msg_Uint_1 := LB;
1564 Error_Msg_N ("entry family low bound must be '>'= ^!", D_Sdef);
1568 if Is_Generic_Type (Etype (D_Sdef))
1570 or else Error_Posted (D_Sdef)
1574 elsif Nkind (D_Sdef) = N_Range then
1575 UBR := High_Bound (D_Sdef);
1577 elsif Is_Entity_Name (D_Sdef)
1578 and then Is_Type (Entity (D_Sdef))
1580 UBR := Type_High_Bound (Entity (D_Sdef));
1586 if Is_Static_Expression (UBR)
1587 and then Expr_Value (UBR) > UB
1589 Error_Msg_Uint_1 := UB;
1590 Error_Msg_N ("entry family high bound must be '<'= ^!", D_Sdef);
1600 Set_Etype (Def_Id, Standard_Void_Type);
1601 Set_Convention (Def_Id, Convention_Entry);
1602 Set_Accept_Address (Def_Id, New_Elmt_List);
1606 if Present (Formals) then
1607 Set_Scope (Def_Id, Current_Scope);
1608 Push_Scope (Def_Id);
1609 Process_Formals (Formals, N);
1610 Create_Extra_Formals (Def_Id);
1614 if Ekind (Def_Id) = E_Entry then
1615 New_Overloaded_Entity (Def_Id);
1618 Generate_Reference_To_Formals (Def_Id);
1620 if Has_Aspects (N) then
1621 Analyze_Aspect_Specifications (N, Def_Id);
1623 end Analyze_Entry_Declaration;
1625 ---------------------------------------
1626 -- Analyze_Entry_Index_Specification --
1627 ---------------------------------------
1629 -- The Defining_Identifier of the entry index specification is local to the
1630 -- entry body, but it must be available in the entry barrier which is
1631 -- evaluated outside of the entry body. The index is eventually renamed as
1632 -- a run-time object, so is visibility is strictly a front-end concern. In
1633 -- order to make it available to the barrier, we create an additional
1634 -- scope, as for a loop, whose only declaration is the index name. This
1635 -- loop is not attached to the tree and does not appear as an entity local
1636 -- to the protected type, so its existence need only be known to routines
1637 -- that process entry families.
1639 procedure Analyze_Entry_Index_Specification (N : Node_Id) is
1640 Iden : constant Node_Id := Defining_Identifier (N);
1641 Def : constant Node_Id := Discrete_Subtype_Definition (N);
1642 Loop_Id : constant Entity_Id := Make_Temporary (Sloc (N), 'L');
1645 Tasking_Used := True;
1648 -- There is no elaboration of the entry index specification. Therefore,
1649 -- if the index is a range, it is not resolved and expanded, but the
1650 -- bounds are inherited from the entry declaration, and reanalyzed.
1651 -- See Analyze_Entry_Body.
1653 if Nkind (Def) /= N_Range then
1654 Make_Index (Def, N);
1657 Set_Ekind (Loop_Id, E_Loop);
1658 Set_Scope (Loop_Id, Current_Scope);
1659 Push_Scope (Loop_Id);
1661 Set_Ekind (Iden, E_Entry_Index_Parameter);
1662 Set_Etype (Iden, Etype (Def));
1663 end Analyze_Entry_Index_Specification;
1665 ----------------------------
1666 -- Analyze_Protected_Body --
1667 ----------------------------
1669 procedure Analyze_Protected_Body (N : Node_Id) is
1670 Body_Id : constant Entity_Id := Defining_Identifier (N);
1673 Spec_Id : Entity_Id;
1674 -- This is initially the entity of the protected object or protected
1675 -- type involved, but is replaced by the protected type always in the
1676 -- case of a single protected declaration, since this is the proper
1677 -- scope to be used.
1680 -- This is the entity of the protected object or protected type
1681 -- involved, and is the entity used for cross-reference purposes (it
1682 -- differs from Spec_Id in the case of a single protected object, since
1683 -- Spec_Id is set to the protected type in this case).
1685 function Lock_Free_Disabled return Boolean;
1686 -- This routine returns False if the protected object has a Lock_Free
1687 -- aspect specification or a Lock_Free pragma that turns off the
1688 -- lock-free implementation (e.g. whose expression is False).
1690 ------------------------
1691 -- Lock_Free_Disabled --
1692 ------------------------
1694 function Lock_Free_Disabled return Boolean is
1695 Ritem : constant Node_Id :=
1697 (Spec_Id, Name_Lock_Free, Check_Parents => False);
1700 if Present (Ritem) then
1702 -- Pragma with one argument
1704 if Nkind (Ritem) = N_Pragma
1705 and then Present (Pragma_Argument_Associations (Ritem))
1711 (First (Pragma_Argument_Associations (Ritem)))));
1713 -- Aspect Specification with expression present
1715 elsif Nkind (Ritem) = N_Aspect_Specification
1716 and then Present (Expression (Ritem))
1718 return Is_False (Static_Boolean (Expression (Ritem)));
1720 -- Otherwise, return False
1728 end Lock_Free_Disabled;
1730 -- Start of processing for Analyze_Protected_Body
1733 Tasking_Used := True;
1734 Set_Ekind (Body_Id, E_Protected_Body);
1735 Spec_Id := Find_Concurrent_Spec (Body_Id);
1737 -- Protected bodies are currently removed by the expander. Since there
1738 -- are no language-defined aspects that apply to a protected body, it is
1739 -- not worth changing the whole expansion to accomodate implementation-
1740 -- defined aspects. Plus we cannot possibly known the semantics of such
1741 -- future implementation defined aspects in order to plan ahead.
1743 if Has_Aspects (N) then
1745 ("aspects on protected bodies are not allowed",
1746 First (Aspect_Specifications (N)));
1748 -- Remove illegal aspects to prevent cascaded errors later on
1753 if Present (Spec_Id)
1754 and then Ekind (Spec_Id) = E_Protected_Type
1758 elsif Present (Spec_Id)
1759 and then Ekind (Etype (Spec_Id)) = E_Protected_Type
1760 and then not Comes_From_Source (Etype (Spec_Id))
1765 Error_Msg_N ("missing specification for protected body", Body_Id);
1770 Generate_Reference (Ref_Id, Body_Id, 'b', Set_Ref => False);
1771 Style.Check_Identifier (Body_Id, Spec_Id);
1773 -- The declarations are always attached to the type
1775 if Ekind (Spec_Id) /= E_Protected_Type then
1776 Spec_Id := Etype (Spec_Id);
1779 Push_Scope (Spec_Id);
1780 Set_Corresponding_Spec (N, Spec_Id);
1781 Set_Corresponding_Body (Parent (Spec_Id), Body_Id);
1782 Set_Has_Completion (Spec_Id);
1783 Install_Declarations (Spec_Id);
1785 Expand_Protected_Body_Declarations (N, Spec_Id);
1787 Last_E := Last_Entity (Spec_Id);
1789 Analyze_Declarations (Declarations (N));
1791 -- For visibility purposes, all entities in the body are private. Set
1792 -- First_Private_Entity accordingly, if there was no private part in the
1793 -- protected declaration.
1795 if No (First_Private_Entity (Spec_Id)) then
1796 if Present (Last_E) then
1797 Set_First_Private_Entity (Spec_Id, Next_Entity (Last_E));
1799 Set_First_Private_Entity (Spec_Id, First_Entity (Spec_Id));
1803 Check_Completion (Body_Id);
1804 Check_References (Spec_Id);
1805 Process_End_Label (N, 't', Ref_Id);
1808 -- When a Lock_Free aspect specification/pragma forces the lock-free
1809 -- implementation, verify the protected body meets all the restrictions,
1810 -- otherwise Allows_Lock_Free_Implementation issues an error message.
1812 if Uses_Lock_Free (Spec_Id) then
1813 if not Allows_Lock_Free_Implementation (N, True) then
1817 -- In other cases, if there is no aspect specification/pragma that
1818 -- disables the lock-free implementation, check both the protected
1819 -- declaration and body satisfy the lock-free restrictions.
1821 elsif not Lock_Free_Disabled
1822 and then Allows_Lock_Free_Implementation (Parent (Spec_Id))
1823 and then Allows_Lock_Free_Implementation (N)
1825 Set_Uses_Lock_Free (Spec_Id);
1827 end Analyze_Protected_Body;
1829 ----------------------------------
1830 -- Analyze_Protected_Definition --
1831 ----------------------------------
1833 procedure Analyze_Protected_Definition (N : Node_Id) is
1837 procedure Undelay_Itypes (T : Entity_Id);
1838 -- Itypes created for the private components of a protected type
1839 -- do not receive freeze nodes, because there is no scope in which
1840 -- they can be elaborated, and they can depend on discriminants of
1841 -- the enclosed protected type. Given that the components can be
1842 -- composite types with inner components, we traverse recursively
1843 -- the private components of the protected type, and indicate that
1844 -- all itypes within are frozen. This ensures that no freeze nodes
1845 -- will be generated for them.
1847 -- On the other hand, components of the corresponding record are
1848 -- frozen (or receive itype references) as for other records.
1850 --------------------
1851 -- Undelay_Itypes --
1852 --------------------
1854 procedure Undelay_Itypes (T : Entity_Id) is
1858 if Is_Protected_Type (T) then
1859 Comp := First_Private_Entity (T);
1860 elsif Is_Record_Type (T) then
1861 Comp := First_Entity (T);
1866 while Present (Comp) loop
1868 and then Is_Itype (Comp)
1870 Set_Has_Delayed_Freeze (Comp, False);
1871 Set_Is_Frozen (Comp);
1873 if Is_Record_Type (Comp)
1874 or else Is_Protected_Type (Comp)
1876 Undelay_Itypes (Comp);
1884 -- Start of processing for Analyze_Protected_Definition
1887 Tasking_Used := True;
1888 Check_SPARK_Restriction ("protected definition is not allowed", N);
1889 Analyze_Declarations (Visible_Declarations (N));
1891 if Present (Private_Declarations (N))
1892 and then not Is_Empty_List (Private_Declarations (N))
1894 L := Last_Entity (Current_Scope);
1895 Analyze_Declarations (Private_Declarations (N));
1898 Set_First_Private_Entity (Current_Scope, Next_Entity (L));
1900 Set_First_Private_Entity (Current_Scope,
1901 First_Entity (Current_Scope));
1905 E := First_Entity (Current_Scope);
1906 while Present (E) loop
1907 if Ekind_In (E, E_Function, E_Procedure) then
1908 Set_Convention (E, Convention_Protected);
1910 elsif Is_Task_Type (Etype (E))
1911 or else Has_Task (Etype (E))
1913 Set_Has_Task (Current_Scope);
1919 Undelay_Itypes (Current_Scope);
1921 Check_Max_Entries (N, Max_Protected_Entries);
1922 Process_End_Label (N, 'e', Current_Scope);
1923 end Analyze_Protected_Definition;
1925 ----------------------------------------
1926 -- Analyze_Protected_Type_Declaration --
1927 ----------------------------------------
1929 procedure Analyze_Protected_Type_Declaration (N : Node_Id) is
1930 Def_Id : constant Entity_Id := Defining_Identifier (N);
1935 if No_Run_Time_Mode then
1936 Error_Msg_CRT ("protected type", N);
1938 if Has_Aspects (N) then
1939 Analyze_Aspect_Specifications (N, Def_Id);
1945 Tasking_Used := True;
1946 Check_Restriction (No_Protected_Types, N);
1948 T := Find_Type_Name (N);
1950 -- In the case of an incomplete type, use the full view, unless it's not
1951 -- present (as can occur for an incomplete view from a limited with).
1953 if Ekind (T) = E_Incomplete_Type and then Present (Full_View (T)) then
1955 Set_Completion_Referenced (T);
1958 Set_Ekind (T, E_Protected_Type);
1959 Set_Is_First_Subtype (T, True);
1960 Init_Size_Align (T);
1962 Set_Has_Delayed_Freeze (T, True);
1963 Set_Stored_Constraint (T, No_Elist);
1966 if Ada_Version >= Ada_2005 then
1967 Check_Interfaces (N, T);
1970 if Present (Discriminant_Specifications (N)) then
1971 if Has_Discriminants (T) then
1973 -- Install discriminants. Also, verify conformance of
1974 -- discriminants of previous and current view. ???
1976 Install_Declarations (T);
1978 Process_Discriminants (N);
1982 Set_Is_Constrained (T, not Has_Discriminants (T));
1984 -- If aspects are present, analyze them now. They can make references
1985 -- to the discriminants of the type, but not to any components.
1987 if Has_Aspects (N) then
1988 Analyze_Aspect_Specifications (N, Def_Id);
1991 Analyze (Protected_Definition (N));
1993 -- In the case where the protected type is declared at a nested level
1994 -- and the No_Local_Protected_Objects restriction applies, issue a
1995 -- warning that objects of the type will violate the restriction.
1997 if Restriction_Check_Required (No_Local_Protected_Objects)
1998 and then not Is_Library_Level_Entity (T)
1999 and then Comes_From_Source (T)
2001 Error_Msg_Sloc := Restrictions_Loc (No_Local_Protected_Objects);
2003 if Error_Msg_Sloc = No_Location then
2005 ("objects of this type will violate " &
2006 "`No_Local_Protected_Objects`??", N);
2009 ("objects of this type will violate " &
2010 "`No_Local_Protected_Objects`#??", N);
2014 -- Protected types with entries are controlled (because of the
2015 -- Protection component if nothing else), same for any protected type
2016 -- with interrupt handlers. Note that we need to analyze the protected
2017 -- definition to set Has_Entries and such.
2019 if (Abort_Allowed or else Restriction_Active (No_Entry_Queue) = False
2020 or else Number_Entries (T) > 1)
2023 or else Has_Interrupt_Handler (T)
2024 or else Has_Attach_Handler (T))
2026 Set_Has_Controlled_Component (T, True);
2029 -- The Ekind of components is E_Void during analysis to detect illegal
2030 -- uses. Now it can be set correctly.
2032 E := First_Entity (Current_Scope);
2033 while Present (E) loop
2034 if Ekind (E) = E_Void then
2035 Set_Ekind (E, E_Component);
2036 Init_Component_Location (E);
2044 -- When a Lock_Free aspect forces the lock-free implementation, check N
2045 -- meets all the lock-free restrictions. Otherwise, an error message is
2046 -- issued by Allows_Lock_Free_Implementation.
2048 if Uses_Lock_Free (Defining_Identifier (N)) then
2050 -- Complain when there is an explicit aspect/pragma Priority (or
2051 -- Interrupt_Priority) while the lock-free implementation is forced
2052 -- by an aspect/pragma.
2055 Id : constant Entity_Id := Defining_Identifier (Original_Node (N));
2056 -- The warning must be issued on the original identifier in order
2057 -- to deal properly with the case of a single protected object.
2059 Prio_Item : constant Node_Id :=
2060 Get_Rep_Item (Def_Id, Name_Priority, False);
2063 if Present (Prio_Item) then
2067 if Nkind (Prio_Item) = N_Aspect_Specification
2068 or else From_Aspect_Specification (Prio_Item)
2070 Error_Msg_Name_1 := Chars (Identifier (Prio_Item));
2071 Error_Msg_NE ("aspect% for & has no effect when Lock_Free" &
2072 " given??", Prio_Item, Id);
2077 Error_Msg_Name_1 := Pragma_Name (Prio_Item);
2078 Error_Msg_NE ("pragma% for & has no effect when Lock_Free" &
2079 " given??", Prio_Item, Id);
2084 if not Allows_Lock_Free_Implementation (N, True) then
2089 -- If the Attach_Handler aspect is specified or the Interrupt_Handler
2090 -- aspect is True, then the initial ceiling priority must be in the
2091 -- range of System.Interrupt_Priority. It is therefore recommanded
2092 -- to use the Interrupt_Priority aspect instead of the Priority aspect.
2094 if Has_Interrupt_Handler (T) or else Has_Attach_Handler (T) then
2096 Prio_Item : constant Node_Id :=
2097 Get_Rep_Item (Def_Id, Name_Priority, False);
2100 if Present (Prio_Item) then
2104 if (Nkind (Prio_Item) = N_Aspect_Specification
2105 or else From_Aspect_Specification (Prio_Item))
2106 and then Chars (Identifier (Prio_Item)) = Name_Priority
2108 Error_Msg_N ("aspect Interrupt_Priority is preferred "
2109 & "in presence of handlers??", Prio_Item);
2113 elsif Nkind (Prio_Item) = N_Pragma
2114 and then Pragma_Name (Prio_Item) = Name_Priority
2116 Error_Msg_N ("pragma Interrupt_Priority is preferred "
2117 & "in presence of handlers??", Prio_Item);
2123 -- Case of a completion of a private declaration
2125 if T /= Def_Id and then Is_Private_Type (Def_Id) then
2127 -- Deal with preelaborable initialization. Note that this processing
2128 -- is done by Process_Full_View, but as can be seen below, in this
2129 -- case the call to Process_Full_View is skipped if any serious
2130 -- errors have occurred, and we don't want to lose this check.
2132 if Known_To_Have_Preelab_Init (Def_Id) then
2133 Set_Must_Have_Preelab_Init (T);
2136 -- Create corresponding record now, because some private dependents
2137 -- may be subtypes of the partial view.
2139 -- Skip if errors are present, to prevent cascaded messages
2141 if Serious_Errors_Detected = 0
2143 -- Also skip if expander is not active
2145 and then Expander_Active
2147 Expand_N_Protected_Type_Declaration (N);
2148 Process_Full_View (N, T, Def_Id);
2151 end Analyze_Protected_Type_Declaration;
2153 ---------------------
2154 -- Analyze_Requeue --
2155 ---------------------
2157 procedure Analyze_Requeue (N : Node_Id) is
2158 Count : Natural := 0;
2159 Entry_Name : Node_Id := Name (N);
2160 Entry_Id : Entity_Id;
2162 Is_Disp_Req : Boolean;
2164 Enclosing : Entity_Id;
2165 Target_Obj : Node_Id := Empty;
2166 Req_Scope : Entity_Id;
2167 Outer_Ent : Entity_Id;
2168 Synch_Type : Entity_Id;
2171 Tasking_Used := True;
2172 Check_SPARK_Restriction ("requeue statement is not allowed", N);
2173 Check_Restriction (No_Requeue_Statements, N);
2174 Check_Unreachable_Code (N);
2177 for J in reverse 0 .. Scope_Stack.Last loop
2178 Enclosing := Scope_Stack.Table (J).Entity;
2179 exit when Is_Entry (Enclosing);
2181 if not Ekind_In (Enclosing, E_Block, E_Loop) then
2182 Error_Msg_N ("requeue must appear within accept or entry body", N);
2187 Analyze (Entry_Name);
2189 if Etype (Entry_Name) = Any_Type then
2193 if Nkind (Entry_Name) = N_Selected_Component then
2194 Target_Obj := Prefix (Entry_Name);
2195 Entry_Name := Selector_Name (Entry_Name);
2198 -- If an explicit target object is given then we have to check the
2199 -- restrictions of 9.5.4(6).
2201 if Present (Target_Obj) then
2203 -- Locate containing concurrent unit and determine enclosing entry
2204 -- body or outermost enclosing accept statement within the unit.
2207 for S in reverse 0 .. Scope_Stack.Last loop
2208 Req_Scope := Scope_Stack.Table (S).Entity;
2210 exit when Ekind (Req_Scope) in Task_Kind
2211 or else Ekind (Req_Scope) in Protected_Kind;
2213 if Is_Entry (Req_Scope) then
2214 Outer_Ent := Req_Scope;
2218 pragma Assert (Present (Outer_Ent));
2220 -- Check that the accessibility level of the target object is not
2221 -- greater or equal to the outermost enclosing accept statement (or
2222 -- entry body) unless it is a parameter of the innermost enclosing
2223 -- accept statement (or entry body).
2225 if Object_Access_Level (Target_Obj) >= Scope_Depth (Outer_Ent)
2227 (not Is_Entity_Name (Target_Obj)
2228 or else Ekind (Entity (Target_Obj)) not in Formal_Kind
2229 or else Enclosing /= Scope (Entity (Target_Obj)))
2232 ("target object has invalid level for requeue", Target_Obj);
2236 -- Overloaded case, find right interpretation
2238 if Is_Overloaded (Entry_Name) then
2241 -- Loop over candidate interpretations and filter out any that are
2242 -- not parameterless, are not type conformant, are not entries, or
2243 -- do not come from source.
2245 Get_First_Interp (Entry_Name, I, It);
2246 while Present (It.Nam) loop
2248 -- Note: we test type conformance here, not subtype conformance.
2249 -- Subtype conformance will be tested later on, but it is better
2250 -- for error output in some cases not to do that here.
2252 if (No (First_Formal (It.Nam))
2253 or else (Type_Conformant (Enclosing, It.Nam)))
2254 and then Ekind (It.Nam) = E_Entry
2256 -- Ada 2005 (AI-345): Since protected and task types have
2257 -- primitive entry wrappers, we only consider source entries.
2259 if Comes_From_Source (It.Nam) then
2267 Get_Next_Interp (I, It);
2271 Error_Msg_N ("no entry matches context", N);
2274 elsif Count > 1 then
2275 Error_Msg_N ("ambiguous entry name in requeue", N);
2279 Set_Is_Overloaded (Entry_Name, False);
2280 Set_Entity (Entry_Name, Entry_Id);
2283 -- Non-overloaded cases
2285 -- For the case of a reference to an element of an entry family, the
2286 -- Entry_Name is an indexed component.
2288 elsif Nkind (Entry_Name) = N_Indexed_Component then
2290 -- Requeue to an entry out of the body
2292 if Nkind (Prefix (Entry_Name)) = N_Selected_Component then
2293 Entry_Id := Entity (Selector_Name (Prefix (Entry_Name)));
2295 -- Requeue from within the body itself
2297 elsif Nkind (Prefix (Entry_Name)) = N_Identifier then
2298 Entry_Id := Entity (Prefix (Entry_Name));
2301 Error_Msg_N ("invalid entry_name specified", N);
2305 -- If we had a requeue of the form REQUEUE A (B), then the parser
2306 -- accepted it (because it could have been a requeue on an entry index.
2307 -- If A turns out not to be an entry family, then the analysis of A (B)
2308 -- turned it into a function call.
2310 elsif Nkind (Entry_Name) = N_Function_Call then
2312 ("arguments not allowed in requeue statement",
2313 First (Parameter_Associations (Entry_Name)));
2316 -- Normal case of no entry family, no argument
2319 Entry_Id := Entity (Entry_Name);
2322 -- Ada 2012 (AI05-0030): Potential dispatching requeue statement. The
2323 -- target type must be a concurrent interface class-wide type and the
2324 -- target must be a procedure, flagged by pragma Implemented. The
2325 -- target may be an access to class-wide type, in which case it must
2328 if Present (Target_Obj) then
2329 Synch_Type := Etype (Target_Obj);
2331 if Is_Access_Type (Synch_Type) then
2332 Synch_Type := Designated_Type (Synch_Type);
2337 Ada_Version >= Ada_2012
2338 and then Present (Target_Obj)
2339 and then Is_Class_Wide_Type (Synch_Type)
2340 and then Is_Concurrent_Interface (Synch_Type)
2341 and then Ekind (Entry_Id) = E_Procedure
2342 and then Has_Rep_Pragma (Entry_Id, Name_Implemented);
2344 -- Resolve entry, and check that it is subtype conformant with the
2345 -- enclosing construct if this construct has formals (RM 9.5.4(5)).
2346 -- Ada 2005 (AI05-0030): Do not emit an error for this specific case.
2348 if not Is_Entry (Entry_Id)
2349 and then not Is_Disp_Req
2351 Error_Msg_N ("expect entry name in requeue statement", Name (N));
2353 elsif Ekind (Entry_Id) = E_Entry_Family
2354 and then Nkind (Entry_Name) /= N_Indexed_Component
2356 Error_Msg_N ("missing index for entry family component", Name (N));
2359 Resolve_Entry (Name (N));
2360 Generate_Reference (Entry_Id, Entry_Name);
2362 if Present (First_Formal (Entry_Id)) then
2363 if VM_Target = JVM_Target then
2365 ("arguments unsupported in requeue statement",
2366 First_Formal (Entry_Id));
2370 -- Ada 2012 (AI05-0030): Perform type conformance after skipping
2371 -- the first parameter of Entry_Id since it is the interface
2372 -- controlling formal.
2374 if Ada_Version >= Ada_2012 and then Is_Disp_Req then
2376 Enclosing_Formal : Entity_Id;
2377 Target_Formal : Entity_Id;
2380 Enclosing_Formal := First_Formal (Enclosing);
2381 Target_Formal := Next_Formal (First_Formal (Entry_Id));
2382 while Present (Enclosing_Formal)
2383 and then Present (Target_Formal)
2385 if not Conforming_Types
2386 (T1 => Etype (Enclosing_Formal),
2387 T2 => Etype (Target_Formal),
2388 Ctype => Subtype_Conformant)
2390 Error_Msg_Node_2 := Target_Formal;
2392 ("formal & is not subtype conformant with &" &
2393 "in dispatching requeue", N, Enclosing_Formal);
2396 Next_Formal (Enclosing_Formal);
2397 Next_Formal (Target_Formal);
2401 Check_Subtype_Conformant (Enclosing, Entry_Id, Name (N));
2404 -- Processing for parameters accessed by the requeue
2410 Ent := First_Formal (Enclosing);
2411 while Present (Ent) loop
2413 -- For OUT or IN OUT parameter, the effect of the requeue is
2414 -- to assign the parameter a value on exit from the requeued
2415 -- body, so we can set it as source assigned. We also clear
2416 -- the Is_True_Constant indication. We do not need to clear
2417 -- Current_Value, since the effect of the requeue is to
2418 -- perform an unconditional goto so that any further
2419 -- references will not occur anyway.
2421 if Ekind_In (Ent, E_Out_Parameter, E_In_Out_Parameter) then
2422 Set_Never_Set_In_Source (Ent, False);
2423 Set_Is_True_Constant (Ent, False);
2426 -- For all parameters, the requeue acts as a reference,
2427 -- since the value of the parameter is passed to the new
2428 -- entry, so we want to suppress unreferenced warnings.
2430 Set_Referenced (Ent);
2437 -- AI05-0225: the target protected object of a requeue must be a
2438 -- variable. This is a binding interpretation that applies to all
2439 -- versions of the language. Note that the subprogram does not have
2440 -- to be a protected operation: it can be an primitive implemented
2441 -- by entry with a formal that is a protected interface.
2443 if Present (Target_Obj)
2444 and then not Is_Variable (Target_Obj)
2447 ("target protected object of requeue must be a variable", N);
2449 end Analyze_Requeue;
2451 ------------------------------
2452 -- Analyze_Selective_Accept --
2453 ------------------------------
2455 procedure Analyze_Selective_Accept (N : Node_Id) is
2456 Alts : constant List_Id := Select_Alternatives (N);
2459 Accept_Present : Boolean := False;
2460 Terminate_Present : Boolean := False;
2461 Delay_Present : Boolean := False;
2462 Relative_Present : Boolean := False;
2463 Alt_Count : Uint := Uint_0;
2466 Tasking_Used := True;
2467 Check_SPARK_Restriction ("select statement is not allowed", N);
2468 Check_Restriction (No_Select_Statements, N);
2470 -- Loop to analyze alternatives
2472 Alt := First (Alts);
2473 while Present (Alt) loop
2474 Alt_Count := Alt_Count + 1;
2477 if Nkind (Alt) = N_Delay_Alternative then
2478 if Delay_Present then
2480 if Relative_Present /=
2481 (Nkind (Delay_Statement (Alt)) = N_Delay_Relative_Statement)
2484 ("delay_until and delay_relative alternatives ", Alt);
2486 ("\cannot appear in the same selective_wait", Alt);
2490 Delay_Present := True;
2492 Nkind (Delay_Statement (Alt)) = N_Delay_Relative_Statement;
2495 elsif Nkind (Alt) = N_Terminate_Alternative then
2496 if Terminate_Present then
2497 Error_Msg_N ("only one terminate alternative allowed", N);
2499 Terminate_Present := True;
2500 Check_Restriction (No_Terminate_Alternatives, N);
2503 elsif Nkind (Alt) = N_Accept_Alternative then
2504 Accept_Present := True;
2506 -- Check for duplicate accept
2510 Stm : constant Node_Id := Accept_Statement (Alt);
2511 EDN : constant Node_Id := Entry_Direct_Name (Stm);
2515 if Nkind (EDN) = N_Identifier
2516 and then No (Condition (Alt))
2517 and then Present (Entity (EDN)) -- defend against junk
2518 and then Ekind (Entity (EDN)) = E_Entry
2520 Ent := Entity (EDN);
2522 Alt1 := First (Alts);
2523 while Alt1 /= Alt loop
2524 if Nkind (Alt1) = N_Accept_Alternative
2525 and then No (Condition (Alt1))
2528 Stm1 : constant Node_Id := Accept_Statement (Alt1);
2529 EDN1 : constant Node_Id := Entry_Direct_Name (Stm1);
2532 if Nkind (EDN1) = N_Identifier then
2533 if Entity (EDN1) = Ent then
2534 Error_Msg_Sloc := Sloc (Stm1);
2536 ("accept duplicates one on line#??", Stm);
2552 Check_Restriction (Max_Select_Alternatives, N, Alt_Count);
2553 Check_Potentially_Blocking_Operation (N);
2555 if Terminate_Present and Delay_Present then
2556 Error_Msg_N ("at most one of terminate or delay alternative", N);
2558 elsif not Accept_Present then
2560 ("select must contain at least one accept alternative", N);
2563 if Present (Else_Statements (N)) then
2564 if Terminate_Present or Delay_Present then
2565 Error_Msg_N ("else part not allowed with other alternatives", N);
2568 Analyze_Statements (Else_Statements (N));
2570 end Analyze_Selective_Accept;
2572 ------------------------------------------
2573 -- Analyze_Single_Protected_Declaration --
2574 ------------------------------------------
2576 procedure Analyze_Single_Protected_Declaration (N : Node_Id) is
2577 Loc : constant Source_Ptr := Sloc (N);
2578 Id : constant Node_Id := Defining_Identifier (N);
2582 O_Name : constant Entity_Id := Id;
2585 Generate_Definition (Id);
2586 Tasking_Used := True;
2588 -- The node is rewritten as a protected type declaration, in exact
2589 -- analogy with what is done with single tasks.
2592 Make_Defining_Identifier (Sloc (Id),
2593 New_External_Name (Chars (Id), 'T'));
2596 Make_Protected_Type_Declaration (Loc,
2597 Defining_Identifier => T,
2598 Protected_Definition => Relocate_Node (Protected_Definition (N)),
2599 Interface_List => Interface_List (N));
2602 Make_Object_Declaration (Loc,
2603 Defining_Identifier => O_Name,
2604 Object_Definition => Make_Identifier (Loc, Chars (T)));
2606 Rewrite (N, T_Decl);
2607 Insert_After (N, O_Decl);
2608 Mark_Rewrite_Insertion (O_Decl);
2610 -- Enter names of type and object before analysis, because the name of
2611 -- the object may be used in its own body.
2614 Set_Ekind (T, E_Protected_Type);
2617 Enter_Name (O_Name);
2618 Set_Ekind (O_Name, E_Variable);
2619 Set_Etype (O_Name, T);
2621 -- Instead of calling Analyze on the new node, call the proper analysis
2622 -- procedure directly. Otherwise the node would be expanded twice, with
2623 -- disastrous result.
2625 Analyze_Protected_Type_Declaration (N);
2627 if Has_Aspects (N) then
2628 Analyze_Aspect_Specifications (N, Id);
2630 end Analyze_Single_Protected_Declaration;
2632 -------------------------------------
2633 -- Analyze_Single_Task_Declaration --
2634 -------------------------------------
2636 procedure Analyze_Single_Task_Declaration (N : Node_Id) is
2637 Loc : constant Source_Ptr := Sloc (N);
2638 Id : constant Node_Id := Defining_Identifier (N);
2642 O_Name : constant Entity_Id := Id;
2645 Generate_Definition (Id);
2646 Tasking_Used := True;
2648 -- The node is rewritten as a task type declaration, followed by an
2649 -- object declaration of that anonymous task type.
2652 Make_Defining_Identifier (Sloc (Id),
2653 New_External_Name (Chars (Id), Suffix => "TK"));
2656 Make_Task_Type_Declaration (Loc,
2657 Defining_Identifier => T,
2658 Task_Definition => Relocate_Node (Task_Definition (N)),
2659 Interface_List => Interface_List (N));
2661 -- We use the original defining identifier of the single task in the
2662 -- generated object declaration, so that debugging information can
2663 -- be attached to it when compiling with -gnatD. The parent of the
2664 -- entity is the new object declaration. The single_task_declaration
2665 -- is not used further in semantics or code generation, but is scanned
2666 -- when generating debug information, and therefore needs the updated
2667 -- Sloc information for the entity (see Sprint). Aspect specifications
2668 -- are moved from the single task node to the object declaration node.
2671 Make_Object_Declaration (Loc,
2672 Defining_Identifier => O_Name,
2673 Object_Definition => Make_Identifier (Loc, Chars (T)));
2675 Rewrite (N, T_Decl);
2676 Insert_After (N, O_Decl);
2677 Mark_Rewrite_Insertion (O_Decl);
2679 -- Enter names of type and object before analysis, because the name of
2680 -- the object may be used in its own body.
2683 Set_Ekind (T, E_Task_Type);
2686 Enter_Name (O_Name);
2687 Set_Ekind (O_Name, E_Variable);
2688 Set_Etype (O_Name, T);
2690 -- Instead of calling Analyze on the new node, call the proper analysis
2691 -- procedure directly. Otherwise the node would be expanded twice, with
2692 -- disastrous result.
2694 Analyze_Task_Type_Declaration (N);
2696 if Has_Aspects (N) then
2697 Analyze_Aspect_Specifications (N, Id);
2699 end Analyze_Single_Task_Declaration;
2701 -----------------------
2702 -- Analyze_Task_Body --
2703 -----------------------
2705 procedure Analyze_Task_Body (N : Node_Id) is
2706 Body_Id : constant Entity_Id := Defining_Identifier (N);
2707 Decls : constant List_Id := Declarations (N);
2708 HSS : constant Node_Id := Handled_Statement_Sequence (N);
2711 Spec_Id : Entity_Id;
2712 -- This is initially the entity of the task or task type involved, but
2713 -- is replaced by the task type always in the case of a single task
2714 -- declaration, since this is the proper scope to be used.
2717 -- This is the entity of the task or task type, and is the entity used
2718 -- for cross-reference purposes (it differs from Spec_Id in the case of
2719 -- a single task, since Spec_Id is set to the task type).
2722 Tasking_Used := True;
2723 Set_Ekind (Body_Id, E_Task_Body);
2724 Set_Scope (Body_Id, Current_Scope);
2725 Spec_Id := Find_Concurrent_Spec (Body_Id);
2727 -- Task bodies are transformed into a subprogram spec and body pair by
2728 -- the expander. Since there are no language-defined aspects that apply
2729 -- to a task body, it is not worth changing the whole expansion to
2730 -- accomodate implementation-defined aspects. Plus we cannot possibly
2731 -- know semantics of such aspects in order to plan ahead.
2733 if Has_Aspects (N) then
2735 ("aspects on task bodies are not allowed",
2736 First (Aspect_Specifications (N)));
2738 -- Remove illegal aspects to prevent cascaded errors later on
2743 -- The spec is either a task type declaration, or a single task
2744 -- declaration for which we have created an anonymous type.
2746 if Present (Spec_Id)
2747 and then Ekind (Spec_Id) = E_Task_Type
2751 elsif Present (Spec_Id)
2752 and then Ekind (Etype (Spec_Id)) = E_Task_Type
2753 and then not Comes_From_Source (Etype (Spec_Id))
2758 Error_Msg_N ("missing specification for task body", Body_Id);
2762 if Has_Completion (Spec_Id)
2763 and then Present (Corresponding_Body (Parent (Spec_Id)))
2765 if Nkind (Parent (Spec_Id)) = N_Task_Type_Declaration then
2766 Error_Msg_NE ("duplicate body for task type&", N, Spec_Id);
2768 Error_Msg_NE ("duplicate body for task&", N, Spec_Id);
2773 Generate_Reference (Ref_Id, Body_Id, 'b', Set_Ref => False);
2774 Style.Check_Identifier (Body_Id, Spec_Id);
2776 -- Deal with case of body of single task (anonymous type was created)
2778 if Ekind (Spec_Id) = E_Variable then
2779 Spec_Id := Etype (Spec_Id);
2782 Push_Scope (Spec_Id);
2783 Set_Corresponding_Spec (N, Spec_Id);
2784 Set_Corresponding_Body (Parent (Spec_Id), Body_Id);
2785 Set_Has_Completion (Spec_Id);
2786 Install_Declarations (Spec_Id);
2787 Last_E := Last_Entity (Spec_Id);
2789 Analyze_Declarations (Decls);
2790 Inspect_Deferred_Constant_Completion (Decls);
2792 -- For visibility purposes, all entities in the body are private. Set
2793 -- First_Private_Entity accordingly, if there was no private part in the
2794 -- protected declaration.
2796 if No (First_Private_Entity (Spec_Id)) then
2797 if Present (Last_E) then
2798 Set_First_Private_Entity (Spec_Id, Next_Entity (Last_E));
2800 Set_First_Private_Entity (Spec_Id, First_Entity (Spec_Id));
2804 -- Mark all handlers as not suitable for local raise optimization,
2805 -- since this optimization causes difficulties in a task context.
2807 if Present (Exception_Handlers (HSS)) then
2811 Handlr := First (Exception_Handlers (HSS));
2812 while Present (Handlr) loop
2813 Set_Local_Raise_Not_OK (Handlr);
2819 -- Now go ahead and complete analysis of the task body
2822 Check_Completion (Body_Id);
2823 Check_References (Body_Id);
2824 Check_References (Spec_Id);
2826 -- Check for entries with no corresponding accept
2832 Ent := First_Entity (Spec_Id);
2833 while Present (Ent) loop
2835 and then not Entry_Accepted (Ent)
2836 and then Comes_From_Source (Ent)
2838 Error_Msg_NE ("no accept for entry &??", N, Ent);
2845 Process_End_Label (HSS, 't', Ref_Id);
2847 end Analyze_Task_Body;
2849 -----------------------------
2850 -- Analyze_Task_Definition --
2851 -----------------------------
2853 procedure Analyze_Task_Definition (N : Node_Id) is
2857 Tasking_Used := True;
2858 Check_SPARK_Restriction ("task definition is not allowed", N);
2860 if Present (Visible_Declarations (N)) then
2861 Analyze_Declarations (Visible_Declarations (N));
2864 if Present (Private_Declarations (N)) then
2865 L := Last_Entity (Current_Scope);
2866 Analyze_Declarations (Private_Declarations (N));
2869 Set_First_Private_Entity
2870 (Current_Scope, Next_Entity (L));
2872 Set_First_Private_Entity
2873 (Current_Scope, First_Entity (Current_Scope));
2877 Check_Max_Entries (N, Max_Task_Entries);
2878 Process_End_Label (N, 'e', Current_Scope);
2879 end Analyze_Task_Definition;
2881 -----------------------------------
2882 -- Analyze_Task_Type_Declaration --
2883 -----------------------------------
2885 procedure Analyze_Task_Type_Declaration (N : Node_Id) is
2886 Def_Id : constant Entity_Id := Defining_Identifier (N);
2890 Check_Restriction (No_Tasking, N);
2891 Tasking_Used := True;
2892 T := Find_Type_Name (N);
2893 Generate_Definition (T);
2895 -- In the case of an incomplete type, use the full view, unless it's not
2896 -- present (as can occur for an incomplete view from a limited with).
2897 -- Initialize the Corresponding_Record_Type (which overlays the Private
2898 -- Dependents field of the incomplete view).
2900 if Ekind (T) = E_Incomplete_Type then
2901 if Present (Full_View (T)) then
2903 Set_Completion_Referenced (T);
2906 Set_Ekind (T, E_Task_Type);
2907 Set_Corresponding_Record_Type (T, Empty);
2911 Set_Ekind (T, E_Task_Type);
2912 Set_Is_First_Subtype (T, True);
2913 Set_Has_Task (T, True);
2914 Init_Size_Align (T);
2916 Set_Has_Delayed_Freeze (T, True);
2917 Set_Stored_Constraint (T, No_Elist);
2920 if Ada_Version >= Ada_2005 then
2921 Check_Interfaces (N, T);
2924 if Present (Discriminant_Specifications (N)) then
2925 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2926 Error_Msg_N ("(Ada 83) task discriminant not allowed!", N);
2929 if Has_Discriminants (T) then
2931 -- Install discriminants. Also, verify conformance of
2932 -- discriminants of previous and current view. ???
2934 Install_Declarations (T);
2936 Process_Discriminants (N);
2940 Set_Is_Constrained (T, not Has_Discriminants (T));
2942 if Has_Aspects (N) then
2943 Analyze_Aspect_Specifications (N, Def_Id);
2946 if Present (Task_Definition (N)) then
2947 Analyze_Task_Definition (Task_Definition (N));
2950 -- In the case where the task type is declared at a nested level and the
2951 -- No_Task_Hierarchy restriction applies, issue a warning that objects
2952 -- of the type will violate the restriction.
2954 if Restriction_Check_Required (No_Task_Hierarchy)
2955 and then not Is_Library_Level_Entity (T)
2956 and then Comes_From_Source (T)
2958 Error_Msg_Sloc := Restrictions_Loc (No_Task_Hierarchy);
2960 if Error_Msg_Sloc = No_Location then
2962 ("objects of this type will violate `No_Task_Hierarchy`??", N);
2965 ("objects of this type will violate `No_Task_Hierarchy`#??", N);
2971 -- Case of a completion of a private declaration
2974 and then Is_Private_Type (Def_Id)
2976 -- Deal with preelaborable initialization. Note that this processing
2977 -- is done by Process_Full_View, but as can be seen below, in this
2978 -- case the call to Process_Full_View is skipped if any serious
2979 -- errors have occurred, and we don't want to lose this check.
2981 if Known_To_Have_Preelab_Init (Def_Id) then
2982 Set_Must_Have_Preelab_Init (T);
2985 -- Create corresponding record now, because some private dependents
2986 -- may be subtypes of the partial view.
2988 -- Skip if errors are present, to prevent cascaded messages
2990 if Serious_Errors_Detected = 0
2992 -- Also skip if expander is not active
2994 and then Expander_Active
2996 Expand_N_Task_Type_Declaration (N);
2997 Process_Full_View (N, T, Def_Id);
3000 end Analyze_Task_Type_Declaration;
3002 -----------------------------------
3003 -- Analyze_Terminate_Alternative --
3004 -----------------------------------
3006 procedure Analyze_Terminate_Alternative (N : Node_Id) is
3008 Tasking_Used := True;
3010 if Present (Pragmas_Before (N)) then
3011 Analyze_List (Pragmas_Before (N));
3014 if Present (Condition (N)) then
3015 Analyze_And_Resolve (Condition (N), Any_Boolean);
3017 end Analyze_Terminate_Alternative;
3019 ------------------------------
3020 -- Analyze_Timed_Entry_Call --
3021 ------------------------------
3023 procedure Analyze_Timed_Entry_Call (N : Node_Id) is
3024 Trigger : constant Node_Id :=
3025 Entry_Call_Statement (Entry_Call_Alternative (N));
3026 Is_Disp_Select : Boolean := False;
3029 Tasking_Used := True;
3030 Check_SPARK_Restriction ("select statement is not allowed", N);
3031 Check_Restriction (No_Select_Statements, N);
3033 -- Ada 2005 (AI-345): The trigger may be a dispatching call
3035 if Ada_Version >= Ada_2005 then
3037 Check_Triggering_Statement (Trigger, N, Is_Disp_Select);
3040 -- Postpone the analysis of the statements till expansion. Analyze only
3041 -- if the expander is disabled in order to catch any semantic errors.
3043 if Is_Disp_Select then
3044 if not Expander_Active then
3045 Analyze (Entry_Call_Alternative (N));
3046 Analyze (Delay_Alternative (N));
3049 -- Regular select analysis
3052 Analyze (Entry_Call_Alternative (N));
3053 Analyze (Delay_Alternative (N));
3055 end Analyze_Timed_Entry_Call;
3057 ------------------------------------
3058 -- Analyze_Triggering_Alternative --
3059 ------------------------------------
3061 procedure Analyze_Triggering_Alternative (N : Node_Id) is
3062 Trigger : constant Node_Id := Triggering_Statement (N);
3065 Tasking_Used := True;
3067 if Present (Pragmas_Before (N)) then
3068 Analyze_List (Pragmas_Before (N));
3073 if Comes_From_Source (Trigger)
3074 and then Nkind (Trigger) not in N_Delay_Statement
3075 and then Nkind (Trigger) /= N_Entry_Call_Statement
3077 if Ada_Version < Ada_2005 then
3079 ("triggering statement must be delay or entry call", Trigger);
3081 -- Ada 2005 (AI-345): If a procedure_call_statement is used for a
3082 -- procedure_or_entry_call, the procedure_name or procedure_prefix
3083 -- of the procedure_call_statement shall denote an entry renamed by a
3084 -- procedure, or (a view of) a primitive subprogram of a limited
3085 -- interface whose first parameter is a controlling parameter.
3087 elsif Nkind (Trigger) = N_Procedure_Call_Statement
3088 and then not Is_Renamed_Entry (Entity (Name (Trigger)))
3089 and then not Is_Controlling_Limited_Procedure
3090 (Entity (Name (Trigger)))
3093 ("triggering statement must be procedure or entry call " &
3094 "or delay statement", Trigger);
3098 if Is_Non_Empty_List (Statements (N)) then
3099 Analyze_Statements (Statements (N));
3101 end Analyze_Triggering_Alternative;
3103 -----------------------
3104 -- Check_Max_Entries --
3105 -----------------------
3107 procedure Check_Max_Entries (D : Node_Id; R : All_Parameter_Restrictions) is
3110 procedure Count (L : List_Id);
3111 -- Count entries in given declaration list
3117 procedure Count (L : List_Id) is
3126 while Present (D) loop
3127 if Nkind (D) = N_Entry_Declaration then
3129 DSD : constant Node_Id :=
3130 Discrete_Subtype_Definition (D);
3133 -- If not an entry family, then just one entry
3136 Ecount := Ecount + 1;
3138 -- If entry family with static bounds, count entries
3140 elsif Is_OK_Static_Subtype (Etype (DSD)) then
3142 Lo : constant Uint :=
3144 (Type_Low_Bound (Etype (DSD)));
3145 Hi : constant Uint :=
3147 (Type_High_Bound (Etype (DSD)));
3151 Ecount := Ecount + Hi - Lo + 1;
3155 -- Entry family with non-static bounds
3158 -- Record an unknown count restriction, and if the
3159 -- restriction is active, post a message or warning.
3161 Check_Restriction (R, D);
3170 -- Start of processing for Check_Max_Entries
3174 Count (Visible_Declarations (D));
3175 Count (Private_Declarations (D));
3178 Check_Restriction (R, D, Ecount);
3180 end Check_Max_Entries;
3182 ----------------------
3183 -- Check_Interfaces --
3184 ----------------------
3186 procedure Check_Interfaces (N : Node_Id; T : Entity_Id) is
3188 Iface_Typ : Entity_Id;
3192 (Nkind_In (N, N_Protected_Type_Declaration, N_Task_Type_Declaration));
3194 if Present (Interface_List (N)) then
3195 Set_Is_Tagged_Type (T);
3197 Iface := First (Interface_List (N));
3198 while Present (Iface) loop
3199 Iface_Typ := Find_Type_Of_Subtype_Indic (Iface);
3201 if not Is_Interface (Iface_Typ) then
3203 ("(Ada 2005) & must be an interface", Iface, Iface_Typ);
3206 -- Ada 2005 (AI-251): "The declaration of a specific descendant
3207 -- of an interface type freezes the interface type" RM 13.14.
3209 Freeze_Before (N, Etype (Iface));
3211 if Nkind (N) = N_Protected_Type_Declaration then
3213 -- Ada 2005 (AI-345): Protected types can only implement
3214 -- limited, synchronized, or protected interfaces (note that
3215 -- the predicate Is_Limited_Interface includes synchronized
3216 -- and protected interfaces).
3218 if Is_Task_Interface (Iface_Typ) then
3219 Error_Msg_N ("(Ada 2005) protected type cannot implement "
3220 & "a task interface", Iface);
3222 elsif not Is_Limited_Interface (Iface_Typ) then
3223 Error_Msg_N ("(Ada 2005) protected type cannot implement "
3224 & "a non-limited interface", Iface);
3227 else pragma Assert (Nkind (N) = N_Task_Type_Declaration);
3229 -- Ada 2005 (AI-345): Task types can only implement limited,
3230 -- synchronized, or task interfaces (note that the predicate
3231 -- Is_Limited_Interface includes synchronized and task
3234 if Is_Protected_Interface (Iface_Typ) then
3235 Error_Msg_N ("(Ada 2005) task type cannot implement a " &
3236 "protected interface", Iface);
3238 elsif not Is_Limited_Interface (Iface_Typ) then
3239 Error_Msg_N ("(Ada 2005) task type cannot implement a " &
3240 "non-limited interface", Iface);
3249 if not Has_Private_Declaration (T) then
3253 -- Additional checks on full-types associated with private type
3254 -- declarations. Search for the private type declaration.
3257 Full_T_Ifaces : Elist_Id;
3260 Priv_T_Ifaces : Elist_Id;
3263 Priv_T := First_Entity (Scope (T));
3265 pragma Assert (Present (Priv_T));
3267 if Is_Type (Priv_T) and then Present (Full_View (Priv_T)) then
3268 exit when Full_View (Priv_T) = T;
3271 Next_Entity (Priv_T);
3274 -- In case of synchronized types covering interfaces the private type
3275 -- declaration must be limited.
3277 if Present (Interface_List (N))
3278 and then not Is_Limited_Type (Priv_T)
3280 Error_Msg_Sloc := Sloc (Priv_T);
3281 Error_Msg_N ("(Ada 2005) limited type declaration expected for " &
3282 "private type#", T);
3285 -- RM 7.3 (7.1/2): If the full view has a partial view that is
3286 -- tagged then check RM 7.3 subsidiary rules.
3288 if Is_Tagged_Type (Priv_T)
3289 and then not Error_Posted (N)
3291 -- RM 7.3 (7.2/2): The partial view shall be a synchronized tagged
3292 -- type if and only if the full type is a synchronized tagged type
3294 if Is_Synchronized_Tagged_Type (Priv_T)
3295 and then not Is_Synchronized_Tagged_Type (T)
3298 ("(Ada 2005) full view must be a synchronized tagged " &
3299 "type (RM 7.3 (7.2/2))", Priv_T);
3301 elsif Is_Synchronized_Tagged_Type (T)
3302 and then not Is_Synchronized_Tagged_Type (Priv_T)
3305 ("(Ada 2005) partial view must be a synchronized tagged " &
3306 "type (RM 7.3 (7.2/2))", T);
3309 -- RM 7.3 (7.3/2): The partial view shall be a descendant of an
3310 -- interface type if and only if the full type is descendant of
3311 -- the interface type.
3313 if Present (Interface_List (N))
3314 or else (Is_Tagged_Type (Priv_T)
3315 and then Has_Interfaces
3316 (Priv_T, Use_Full_View => False))
3318 if Is_Tagged_Type (Priv_T) then
3320 (Priv_T, Priv_T_Ifaces, Use_Full_View => False);
3323 if Is_Tagged_Type (T) then
3324 Collect_Interfaces (T, Full_T_Ifaces);
3327 Iface := Find_Hidden_Interface (Priv_T_Ifaces, Full_T_Ifaces);
3329 if Present (Iface) then
3331 ("interface in partial view& not implemented by full "
3332 & "type (RM-2005 7.3 (7.3/2))", T, Iface);
3335 Iface := Find_Hidden_Interface (Full_T_Ifaces, Priv_T_Ifaces);
3337 if Present (Iface) then
3339 ("interface & not implemented by partial " &
3340 "view (RM-2005 7.3 (7.3/2))", T, Iface);
3345 end Check_Interfaces;
3347 --------------------------------
3348 -- Check_Triggering_Statement --
3349 --------------------------------
3351 procedure Check_Triggering_Statement
3353 Error_Node : Node_Id;
3354 Is_Dispatching : out Boolean)
3359 Is_Dispatching := False;
3361 -- It is not possible to have a dispatching trigger if we are not in
3364 if Ada_Version >= Ada_2005
3365 and then Nkind (Trigger) = N_Procedure_Call_Statement
3366 and then Present (Parameter_Associations (Trigger))
3368 Param := First (Parameter_Associations (Trigger));
3370 if Is_Controlling_Actual (Param)
3371 and then Is_Interface (Etype (Param))
3373 if Is_Limited_Record (Etype (Param)) then
3374 Is_Dispatching := True;
3377 ("dispatching operation of limited or synchronized " &
3378 "interface required (RM 9.7.2(3))!", Error_Node);
3381 elsif Nkind (Trigger) = N_Explicit_Dereference then
3383 ("entry call or dispatching primitive of interface required ",
3387 end Check_Triggering_Statement;
3389 --------------------------
3390 -- Find_Concurrent_Spec --
3391 --------------------------
3393 function Find_Concurrent_Spec (Body_Id : Entity_Id) return Entity_Id is
3394 Spec_Id : Entity_Id := Current_Entity_In_Scope (Body_Id);
3397 -- The type may have been given by an incomplete type declaration.
3398 -- Find full view now.
3400 if Present (Spec_Id) and then Ekind (Spec_Id) = E_Incomplete_Type then
3401 Spec_Id := Full_View (Spec_Id);
3405 end Find_Concurrent_Spec;
3407 --------------------------
3408 -- Install_Declarations --
3409 --------------------------
3411 procedure Install_Declarations (Spec : Entity_Id) is
3415 E := First_Entity (Spec);
3416 while Present (E) loop
3417 Prev := Current_Entity (E);
3418 Set_Current_Entity (E);
3419 Set_Is_Immediately_Visible (E);
3420 Set_Homonym (E, Prev);
3423 end Install_Declarations;