PR rtl-optimization/82913
[official-gcc.git] / gcc / ada / contracts.adb
blob1bd13bd91d3bccfd1e2726b7cc2a68776015d1f9
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- C O N T R A C T S --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 2015-2017, Free Software Foundation, Inc. --
10 -- --
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. --
20 -- --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
23 -- --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Prag; use Exp_Prag;
33 with Exp_Tss; use Exp_Tss;
34 with Exp_Util; use Exp_Util;
35 with Namet; use Namet;
36 with Nlists; use Nlists;
37 with Nmake; use Nmake;
38 with Opt; use Opt;
39 with Sem; use Sem;
40 with Sem_Aux; use Sem_Aux;
41 with Sem_Ch6; use Sem_Ch6;
42 with Sem_Ch8; use Sem_Ch8;
43 with Sem_Ch12; use Sem_Ch12;
44 with Sem_Ch13; use Sem_Ch13;
45 with Sem_Disp; use Sem_Disp;
46 with Sem_Prag; use Sem_Prag;
47 with Sem_Util; use Sem_Util;
48 with Sinfo; use Sinfo;
49 with Snames; use Snames;
50 with Stringt; use Stringt;
51 with SCIL_LL; use SCIL_LL;
52 with Tbuild; use Tbuild;
54 package body Contracts is
56 procedure Build_And_Analyze_Contract_Only_Subprograms (L : List_Id);
57 -- (CodePeer): Subsidiary procedure to Analyze_Contracts which builds the
58 -- contract-only subprogram body of eligible subprograms found in L, adds
59 -- them to their corresponding list of declarations, and analyzes them.
61 procedure Expand_Subprogram_Contract (Body_Id : Entity_Id);
62 -- Expand the contracts of a subprogram body and its correspoding spec (if
63 -- any). This routine processes all [refined] pre- and postconditions as
64 -- well as Contract_Cases, invariants and predicates. Body_Id denotes the
65 -- entity of the subprogram body.
67 -----------------------
68 -- Add_Contract_Item --
69 -----------------------
71 procedure Add_Contract_Item (Prag : Node_Id; Id : Entity_Id) is
72 Items : Node_Id := Contract (Id);
74 procedure Add_Classification;
75 -- Prepend Prag to the list of classifications
77 procedure Add_Contract_Test_Case;
78 -- Prepend Prag to the list of contract and test cases
80 procedure Add_Pre_Post_Condition;
81 -- Prepend Prag to the list of pre- and postconditions
83 ------------------------
84 -- Add_Classification --
85 ------------------------
87 procedure Add_Classification is
88 begin
89 Set_Next_Pragma (Prag, Classifications (Items));
90 Set_Classifications (Items, Prag);
91 end Add_Classification;
93 ----------------------------
94 -- Add_Contract_Test_Case --
95 ----------------------------
97 procedure Add_Contract_Test_Case is
98 begin
99 Set_Next_Pragma (Prag, Contract_Test_Cases (Items));
100 Set_Contract_Test_Cases (Items, Prag);
101 end Add_Contract_Test_Case;
103 ----------------------------
104 -- Add_Pre_Post_Condition --
105 ----------------------------
107 procedure Add_Pre_Post_Condition is
108 begin
109 Set_Next_Pragma (Prag, Pre_Post_Conditions (Items));
110 Set_Pre_Post_Conditions (Items, Prag);
111 end Add_Pre_Post_Condition;
113 -- Local variables
115 -- A contract must contain only pragmas
117 pragma Assert (Nkind (Prag) = N_Pragma);
118 Prag_Nam : constant Name_Id := Pragma_Name (Prag);
120 -- Start of processing for Add_Contract_Item
122 begin
123 -- Create a new contract when adding the first item
125 if No (Items) then
126 Items := Make_Contract (Sloc (Id));
127 Set_Contract (Id, Items);
128 end if;
130 -- Constants, the applicable pragmas are:
131 -- Part_Of
133 if Ekind (Id) = E_Constant then
134 if Prag_Nam = Name_Part_Of then
135 Add_Classification;
137 -- The pragma is not a proper contract item
139 else
140 raise Program_Error;
141 end if;
143 -- Entry bodies, the applicable pragmas are:
144 -- Refined_Depends
145 -- Refined_Global
146 -- Refined_Post
148 elsif Is_Entry_Body (Id) then
149 if Nam_In (Prag_Nam, Name_Refined_Depends, Name_Refined_Global) then
150 Add_Classification;
152 elsif Prag_Nam = Name_Refined_Post then
153 Add_Pre_Post_Condition;
155 -- The pragma is not a proper contract item
157 else
158 raise Program_Error;
159 end if;
161 -- Entry or subprogram declarations, the applicable pragmas are:
162 -- Attach_Handler
163 -- Contract_Cases
164 -- Depends
165 -- Extensions_Visible
166 -- Global
167 -- Interrupt_Handler
168 -- Postcondition
169 -- Precondition
170 -- Test_Case
171 -- Volatile_Function
173 elsif Is_Entry_Declaration (Id)
174 or else Ekind_In (Id, E_Function,
175 E_Generic_Function,
176 E_Generic_Procedure,
177 E_Procedure)
178 then
179 if Nam_In (Prag_Nam, Name_Attach_Handler, Name_Interrupt_Handler)
180 and then Ekind_In (Id, E_Generic_Procedure, E_Procedure)
181 then
182 Add_Classification;
184 elsif Nam_In (Prag_Nam, Name_Depends,
185 Name_Extensions_Visible,
186 Name_Global)
187 then
188 Add_Classification;
190 elsif Prag_Nam = Name_Volatile_Function
191 and then Ekind_In (Id, E_Function, E_Generic_Function)
192 then
193 Add_Classification;
195 elsif Nam_In (Prag_Nam, Name_Contract_Cases, Name_Test_Case) then
196 Add_Contract_Test_Case;
198 elsif Nam_In (Prag_Nam, Name_Postcondition, Name_Precondition) then
199 Add_Pre_Post_Condition;
201 -- The pragma is not a proper contract item
203 else
204 raise Program_Error;
205 end if;
207 -- Packages or instantiations, the applicable pragmas are:
208 -- Abstract_States
209 -- Initial_Condition
210 -- Initializes
211 -- Part_Of (instantiation only)
213 elsif Ekind_In (Id, E_Generic_Package, E_Package) then
214 if Nam_In (Prag_Nam, Name_Abstract_State,
215 Name_Initial_Condition,
216 Name_Initializes)
217 then
218 Add_Classification;
220 -- Indicator Part_Of must be associated with a package instantiation
222 elsif Prag_Nam = Name_Part_Of and then Is_Generic_Instance (Id) then
223 Add_Classification;
225 -- The pragma is not a proper contract item
227 else
228 raise Program_Error;
229 end if;
231 -- Package bodies, the applicable pragmas are:
232 -- Refined_States
234 elsif Ekind (Id) = E_Package_Body then
235 if Prag_Nam = Name_Refined_State then
236 Add_Classification;
238 -- The pragma is not a proper contract item
240 else
241 raise Program_Error;
242 end if;
244 -- Protected units, the applicable pragmas are:
245 -- Part_Of
247 elsif Ekind (Id) = E_Protected_Type then
248 if Prag_Nam = Name_Part_Of then
249 Add_Classification;
251 -- The pragma is not a proper contract item
253 else
254 raise Program_Error;
255 end if;
257 -- Subprogram bodies, the applicable pragmas are:
258 -- Postcondition
259 -- Precondition
260 -- Refined_Depends
261 -- Refined_Global
262 -- Refined_Post
264 elsif Ekind (Id) = E_Subprogram_Body then
265 if Nam_In (Prag_Nam, Name_Refined_Depends, Name_Refined_Global) then
266 Add_Classification;
268 elsif Nam_In (Prag_Nam, Name_Postcondition,
269 Name_Precondition,
270 Name_Refined_Post)
271 then
272 Add_Pre_Post_Condition;
274 -- The pragma is not a proper contract item
276 else
277 raise Program_Error;
278 end if;
280 -- Task bodies, the applicable pragmas are:
281 -- Refined_Depends
282 -- Refined_Global
284 elsif Ekind (Id) = E_Task_Body then
285 if Nam_In (Prag_Nam, Name_Refined_Depends, Name_Refined_Global) then
286 Add_Classification;
288 -- The pragma is not a proper contract item
290 else
291 raise Program_Error;
292 end if;
294 -- Task units, the applicable pragmas are:
295 -- Depends
296 -- Global
297 -- Part_Of
299 elsif Ekind (Id) = E_Task_Type then
300 if Nam_In (Prag_Nam, Name_Depends, Name_Global, Name_Part_Of) then
301 Add_Classification;
303 -- The pragma is not a proper contract item
305 else
306 raise Program_Error;
307 end if;
309 -- Variables, the applicable pragmas are:
310 -- Async_Readers
311 -- Async_Writers
312 -- Constant_After_Elaboration
313 -- Depends
314 -- Effective_Reads
315 -- Effective_Writes
316 -- Global
317 -- Part_Of
319 elsif Ekind (Id) = E_Variable then
320 if Nam_In (Prag_Nam, Name_Async_Readers,
321 Name_Async_Writers,
322 Name_Constant_After_Elaboration,
323 Name_Depends,
324 Name_Effective_Reads,
325 Name_Effective_Writes,
326 Name_Global,
327 Name_Part_Of)
328 then
329 Add_Classification;
331 -- The pragma is not a proper contract item
333 else
334 raise Program_Error;
335 end if;
336 end if;
337 end Add_Contract_Item;
339 -----------------------
340 -- Analyze_Contracts --
341 -----------------------
343 procedure Analyze_Contracts (L : List_Id) is
344 Decl : Node_Id;
346 begin
347 if CodePeer_Mode and then Debug_Flag_Dot_KK then
348 Build_And_Analyze_Contract_Only_Subprograms (L);
349 end if;
351 Decl := First (L);
352 while Present (Decl) loop
354 -- Entry or subprogram declarations
356 if Nkind_In (Decl, N_Abstract_Subprogram_Declaration,
357 N_Entry_Declaration,
358 N_Generic_Subprogram_Declaration,
359 N_Subprogram_Declaration)
360 then
361 declare
362 Subp_Id : constant Entity_Id := Defining_Entity (Decl);
364 begin
365 Analyze_Entry_Or_Subprogram_Contract (Subp_Id);
367 -- If analysis of a class-wide pre/postcondition indicates
368 -- that a class-wide clone is needed, analyze its declaration
369 -- now. Its body is created when the body of the original
370 -- operation is analyzed (and rewritten).
372 if Is_Subprogram (Subp_Id)
373 and then Present (Class_Wide_Clone (Subp_Id))
374 then
375 Analyze (Unit_Declaration_Node (Class_Wide_Clone (Subp_Id)));
376 end if;
377 end;
379 -- Entry or subprogram bodies
381 elsif Nkind_In (Decl, N_Entry_Body, N_Subprogram_Body) then
382 Analyze_Entry_Or_Subprogram_Body_Contract (Defining_Entity (Decl));
384 -- Objects
386 elsif Nkind (Decl) = N_Object_Declaration then
387 Analyze_Object_Contract (Defining_Entity (Decl));
389 -- Protected units
391 elsif Nkind_In (Decl, N_Protected_Type_Declaration,
392 N_Single_Protected_Declaration)
393 then
394 Analyze_Protected_Contract (Defining_Entity (Decl));
396 -- Subprogram body stubs
398 elsif Nkind (Decl) = N_Subprogram_Body_Stub then
399 Analyze_Subprogram_Body_Stub_Contract (Defining_Entity (Decl));
401 -- Task units
403 elsif Nkind_In (Decl, N_Single_Task_Declaration,
404 N_Task_Type_Declaration)
405 then
406 Analyze_Task_Contract (Defining_Entity (Decl));
408 -- For type declarations, we need to do the pre-analysis of Iterable
409 -- aspect specifications.
411 -- Other type aspects need to be resolved here???
413 elsif Nkind (Decl) = N_Private_Type_Declaration
414 and then Present (Aspect_Specifications (Decl))
415 then
416 declare
417 E : constant Entity_Id := Defining_Identifier (Decl);
418 It : constant Node_Id := Find_Aspect (E, Aspect_Iterable);
420 begin
421 if Present (It) then
422 Validate_Iterable_Aspect (E, It);
423 end if;
424 end;
425 end if;
427 Next (Decl);
428 end loop;
429 end Analyze_Contracts;
431 -----------------------------------------------
432 -- Analyze_Entry_Or_Subprogram_Body_Contract --
433 -----------------------------------------------
435 -- WARNING: This routine manages SPARK regions. Return statements must be
436 -- replaced by gotos which jump to the end of the routine and restore the
437 -- SPARK mode.
439 procedure Analyze_Entry_Or_Subprogram_Body_Contract (Body_Id : Entity_Id) is
440 Body_Decl : constant Node_Id := Unit_Declaration_Node (Body_Id);
441 Items : constant Node_Id := Contract (Body_Id);
442 Spec_Id : constant Entity_Id := Unique_Defining_Entity (Body_Decl);
444 Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
445 Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
446 -- Save the SPARK_Mode-related data to restore on exit
448 begin
449 -- When a subprogram body declaration is illegal, its defining entity is
450 -- left unanalyzed. There is nothing left to do in this case because the
451 -- body lacks a contract, or even a proper Ekind.
453 if Ekind (Body_Id) = E_Void then
454 return;
456 -- Do not analyze a contract multiple times
458 elsif Present (Items) then
459 if Analyzed (Items) then
460 return;
461 else
462 Set_Analyzed (Items);
463 end if;
464 end if;
466 -- Due to the timing of contract analysis, delayed pragmas may be
467 -- subject to the wrong SPARK_Mode, usually that of the enclosing
468 -- context. To remedy this, restore the original SPARK_Mode of the
469 -- related subprogram body.
471 Set_SPARK_Mode (Body_Id);
473 -- Ensure that the contract cases or postconditions mention 'Result or
474 -- define a post-state.
476 Check_Result_And_Post_State (Body_Id);
478 -- A stand-alone nonvolatile function body cannot have an effectively
479 -- volatile formal parameter or return type (SPARK RM 7.1.3(9)). This
480 -- check is relevant only when SPARK_Mode is on, as it is not a standard
481 -- legality rule. The check is performed here because Volatile_Function
482 -- is processed after the analysis of the related subprogram body. The
483 -- check only applies to source subprograms and not to generated TSS
484 -- subprograms.
486 if SPARK_Mode = On
487 and then Ekind_In (Body_Id, E_Function, E_Generic_Function)
488 and then Comes_From_Source (Spec_Id)
489 and then not Is_Volatile_Function (Body_Id)
490 then
491 Check_Nonvolatile_Function_Profile (Body_Id);
492 end if;
494 -- Restore the SPARK_Mode of the enclosing context after all delayed
495 -- pragmas have been analyzed.
497 Restore_SPARK_Mode (Saved_SM, Saved_SMP);
499 -- Capture all global references in a generic subprogram body now that
500 -- the contract has been analyzed.
502 if Is_Generic_Declaration_Or_Body (Body_Decl) then
503 Save_Global_References_In_Contract
504 (Templ => Original_Node (Body_Decl),
505 Gen_Id => Spec_Id);
506 end if;
508 -- Deal with preconditions, [refined] postconditions, Contract_Cases,
509 -- invariants and predicates associated with body and its spec. Do not
510 -- expand the contract of subprogram body stubs.
512 if Nkind (Body_Decl) = N_Subprogram_Body then
513 Expand_Subprogram_Contract (Body_Id);
514 end if;
515 end Analyze_Entry_Or_Subprogram_Body_Contract;
517 ------------------------------------------
518 -- Analyze_Entry_Or_Subprogram_Contract --
519 ------------------------------------------
521 -- WARNING: This routine manages SPARK regions. Return statements must be
522 -- replaced by gotos which jump to the end of the routine and restore the
523 -- SPARK mode.
525 procedure Analyze_Entry_Or_Subprogram_Contract
526 (Subp_Id : Entity_Id;
527 Freeze_Id : Entity_Id := Empty)
529 Items : constant Node_Id := Contract (Subp_Id);
530 Subp_Decl : constant Node_Id := Unit_Declaration_Node (Subp_Id);
532 Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
533 Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
534 -- Save the SPARK_Mode-related data to restore on exit
536 Skip_Assert_Exprs : constant Boolean :=
537 Ekind_In (Subp_Id, E_Entry, E_Entry_Family)
538 and then not ASIS_Mode
539 and then not GNATprove_Mode;
541 Depends : Node_Id := Empty;
542 Global : Node_Id := Empty;
543 Prag : Node_Id;
544 Prag_Nam : Name_Id;
546 begin
547 -- Do not analyze a contract multiple times
549 if Present (Items) then
550 if Analyzed (Items) then
551 return;
552 else
553 Set_Analyzed (Items);
554 end if;
555 end if;
557 -- Due to the timing of contract analysis, delayed pragmas may be
558 -- subject to the wrong SPARK_Mode, usually that of the enclosing
559 -- context. To remedy this, restore the original SPARK_Mode of the
560 -- related subprogram body.
562 Set_SPARK_Mode (Subp_Id);
564 -- All subprograms carry a contract, but for some it is not significant
565 -- and should not be processed.
567 if not Has_Significant_Contract (Subp_Id) then
568 null;
570 elsif Present (Items) then
572 -- Do not analyze the pre/postconditions of an entry declaration
573 -- unless annotating the original tree for ASIS or GNATprove. The
574 -- real analysis occurs when the pre/postconditons are relocated to
575 -- the contract wrapper procedure (see Build_Contract_Wrapper).
577 if Skip_Assert_Exprs then
578 null;
580 -- Otherwise analyze the pre/postconditions
582 else
583 Prag := Pre_Post_Conditions (Items);
584 while Present (Prag) loop
585 Analyze_Pre_Post_Condition_In_Decl_Part (Prag, Freeze_Id);
586 Prag := Next_Pragma (Prag);
587 end loop;
588 end if;
590 -- Analyze contract-cases and test-cases
592 Prag := Contract_Test_Cases (Items);
593 while Present (Prag) loop
594 Prag_Nam := Pragma_Name (Prag);
596 if Prag_Nam = Name_Contract_Cases then
598 -- Do not analyze the contract cases of an entry declaration
599 -- unless annotating the original tree for ASIS or GNATprove.
600 -- The real analysis occurs when the contract cases are moved
601 -- to the contract wrapper procedure (Build_Contract_Wrapper).
603 if Skip_Assert_Exprs then
604 null;
606 -- Otherwise analyze the contract cases
608 else
609 Analyze_Contract_Cases_In_Decl_Part (Prag, Freeze_Id);
610 end if;
611 else
612 pragma Assert (Prag_Nam = Name_Test_Case);
613 Analyze_Test_Case_In_Decl_Part (Prag);
614 end if;
616 Prag := Next_Pragma (Prag);
617 end loop;
619 -- Analyze classification pragmas
621 Prag := Classifications (Items);
622 while Present (Prag) loop
623 Prag_Nam := Pragma_Name (Prag);
625 if Prag_Nam = Name_Depends then
626 Depends := Prag;
628 elsif Prag_Nam = Name_Global then
629 Global := Prag;
630 end if;
632 Prag := Next_Pragma (Prag);
633 end loop;
635 -- Analyze Global first, as Depends may mention items classified in
636 -- the global categorization.
638 if Present (Global) then
639 Analyze_Global_In_Decl_Part (Global);
640 end if;
642 -- Depends must be analyzed after Global in order to see the modes of
643 -- all global items.
645 if Present (Depends) then
646 Analyze_Depends_In_Decl_Part (Depends);
647 end if;
649 -- Ensure that the contract cases or postconditions mention 'Result
650 -- or define a post-state.
652 Check_Result_And_Post_State (Subp_Id);
653 end if;
655 -- A nonvolatile function cannot have an effectively volatile formal
656 -- parameter or return type (SPARK RM 7.1.3(9)). This check is relevant
657 -- only when SPARK_Mode is on, as it is not a standard legality rule.
658 -- The check is performed here because pragma Volatile_Function is
659 -- processed after the analysis of the related subprogram declaration.
661 if SPARK_Mode = On
662 and then Ekind_In (Subp_Id, E_Function, E_Generic_Function)
663 and then Comes_From_Source (Subp_Id)
664 and then not Is_Volatile_Function (Subp_Id)
665 then
666 Check_Nonvolatile_Function_Profile (Subp_Id);
667 end if;
669 -- Restore the SPARK_Mode of the enclosing context after all delayed
670 -- pragmas have been analyzed.
672 Restore_SPARK_Mode (Saved_SM, Saved_SMP);
674 -- Capture all global references in a generic subprogram now that the
675 -- contract has been analyzed.
677 if Is_Generic_Declaration_Or_Body (Subp_Decl) then
678 Save_Global_References_In_Contract
679 (Templ => Original_Node (Subp_Decl),
680 Gen_Id => Subp_Id);
681 end if;
682 end Analyze_Entry_Or_Subprogram_Contract;
684 -----------------------------
685 -- Analyze_Object_Contract --
686 -----------------------------
688 -- WARNING: This routine manages SPARK regions. Return statements must be
689 -- replaced by gotos which jump to the end of the routine and restore the
690 -- SPARK mode.
692 procedure Analyze_Object_Contract
693 (Obj_Id : Entity_Id;
694 Freeze_Id : Entity_Id := Empty)
696 Obj_Typ : constant Entity_Id := Etype (Obj_Id);
698 Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
699 Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
700 -- Save the SPARK_Mode-related data to restore on exit
702 AR_Val : Boolean := False;
703 AW_Val : Boolean := False;
704 ER_Val : Boolean := False;
705 EW_Val : Boolean := False;
706 Items : Node_Id;
707 Prag : Node_Id;
708 Ref_Elmt : Elmt_Id;
709 Seen : Boolean := False;
711 begin
712 -- The loop parameter in an element iterator over a formal container
713 -- is declared with an object declaration, but no contracts apply.
715 if Ekind (Obj_Id) = E_Loop_Parameter then
716 return;
717 end if;
719 -- Do not analyze a contract multiple times
721 Items := Contract (Obj_Id);
723 if Present (Items) then
724 if Analyzed (Items) then
725 return;
726 else
727 Set_Analyzed (Items);
728 end if;
729 end if;
731 -- The anonymous object created for a single concurrent type inherits
732 -- the SPARK_Mode from the type. Due to the timing of contract analysis,
733 -- delayed pragmas may be subject to the wrong SPARK_Mode, usually that
734 -- of the enclosing context. To remedy this, restore the original mode
735 -- of the related anonymous object.
737 if Is_Single_Concurrent_Object (Obj_Id)
738 and then Present (SPARK_Pragma (Obj_Id))
739 then
740 Set_SPARK_Mode (Obj_Id);
741 end if;
743 -- Constant-related checks
745 if Ekind (Obj_Id) = E_Constant then
747 -- Analyze indicator Part_Of
749 Prag := Get_Pragma (Obj_Id, Pragma_Part_Of);
751 -- Check whether the lack of indicator Part_Of agrees with the
752 -- placement of the constant with respect to the state space.
754 if No (Prag) then
755 Check_Missing_Part_Of (Obj_Id);
756 end if;
758 -- A constant cannot be effectively volatile (SPARK RM 7.1.3(4)).
759 -- This check is relevant only when SPARK_Mode is on, as it is not
760 -- a standard Ada legality rule. Internally-generated constants that
761 -- map generic formals to actuals in instantiations are allowed to
762 -- be volatile.
764 if SPARK_Mode = On
765 and then Comes_From_Source (Obj_Id)
766 and then Is_Effectively_Volatile (Obj_Id)
767 and then No (Corresponding_Generic_Association (Parent (Obj_Id)))
768 then
769 Error_Msg_N ("constant cannot be volatile", Obj_Id);
770 end if;
772 -- Variable-related checks
774 else pragma Assert (Ekind (Obj_Id) = E_Variable);
776 -- Analyze all external properties
778 Prag := Get_Pragma (Obj_Id, Pragma_Async_Readers);
780 if Present (Prag) then
781 Analyze_External_Property_In_Decl_Part (Prag, AR_Val);
782 Seen := True;
783 end if;
785 Prag := Get_Pragma (Obj_Id, Pragma_Async_Writers);
787 if Present (Prag) then
788 Analyze_External_Property_In_Decl_Part (Prag, AW_Val);
789 Seen := True;
790 end if;
792 Prag := Get_Pragma (Obj_Id, Pragma_Effective_Reads);
794 if Present (Prag) then
795 Analyze_External_Property_In_Decl_Part (Prag, ER_Val);
796 Seen := True;
797 end if;
799 Prag := Get_Pragma (Obj_Id, Pragma_Effective_Writes);
801 if Present (Prag) then
802 Analyze_External_Property_In_Decl_Part (Prag, EW_Val);
803 Seen := True;
804 end if;
806 -- Verify the mutual interaction of the various external properties
808 if Seen then
809 Check_External_Properties (Obj_Id, AR_Val, AW_Val, ER_Val, EW_Val);
810 end if;
812 -- The anonymous object created for a single concurrent type carries
813 -- pragmas Depends and Globat of the type.
815 if Is_Single_Concurrent_Object (Obj_Id) then
817 -- Analyze Global first, as Depends may mention items classified
818 -- in the global categorization.
820 Prag := Get_Pragma (Obj_Id, Pragma_Global);
822 if Present (Prag) then
823 Analyze_Global_In_Decl_Part (Prag);
824 end if;
826 -- Depends must be analyzed after Global in order to see the modes
827 -- of all global items.
829 Prag := Get_Pragma (Obj_Id, Pragma_Depends);
831 if Present (Prag) then
832 Analyze_Depends_In_Decl_Part (Prag);
833 end if;
834 end if;
836 Prag := Get_Pragma (Obj_Id, Pragma_Part_Of);
838 -- Analyze indicator Part_Of
840 if Present (Prag) then
841 Analyze_Part_Of_In_Decl_Part (Prag, Freeze_Id);
843 -- The variable is a constituent of a single protected/task type
844 -- and behaves as a component of the type. Verify that references
845 -- to the variable occur within the definition or body of the type
846 -- (SPARK RM 9.3).
848 if Present (Encapsulating_State (Obj_Id))
849 and then Is_Single_Concurrent_Object
850 (Encapsulating_State (Obj_Id))
851 and then Present (Part_Of_References (Obj_Id))
852 then
853 Ref_Elmt := First_Elmt (Part_Of_References (Obj_Id));
854 while Present (Ref_Elmt) loop
855 Check_Part_Of_Reference (Obj_Id, Node (Ref_Elmt));
856 Next_Elmt (Ref_Elmt);
857 end loop;
858 end if;
860 -- Otherwise check whether the lack of indicator Part_Of agrees with
861 -- the placement of the variable with respect to the state space.
863 else
864 Check_Missing_Part_Of (Obj_Id);
865 end if;
867 -- The following checks are relevant only when SPARK_Mode is on, as
868 -- they are not standard Ada legality rules. Internally generated
869 -- temporaries are ignored.
871 if SPARK_Mode = On and then Comes_From_Source (Obj_Id) then
872 if Is_Effectively_Volatile (Obj_Id) then
874 -- The declaration of an effectively volatile object must
875 -- appear at the library level (SPARK RM 7.1.3(3), C.6(6)).
877 if not Is_Library_Level_Entity (Obj_Id) then
878 Error_Msg_N
879 ("volatile variable & must be declared at library level",
880 Obj_Id);
882 -- An object of a discriminated type cannot be effectively
883 -- volatile except for protected objects (SPARK RM 7.1.3(5)).
885 elsif Has_Discriminants (Obj_Typ)
886 and then not Is_Protected_Type (Obj_Typ)
887 then
888 Error_Msg_N
889 ("discriminated object & cannot be volatile", Obj_Id);
890 end if;
892 -- The object is not effectively volatile
894 else
895 -- A non-effectively volatile object cannot have effectively
896 -- volatile components (SPARK RM 7.1.3(6)).
898 if not Is_Effectively_Volatile (Obj_Id)
899 and then Has_Volatile_Component (Obj_Typ)
900 then
901 Error_Msg_N
902 ("non-volatile object & cannot have volatile components",
903 Obj_Id);
904 end if;
905 end if;
906 end if;
907 end if;
909 -- Common checks
911 if Comes_From_Source (Obj_Id) and then Is_Ghost_Entity (Obj_Id) then
913 -- A Ghost object cannot be of a type that yields a synchronized
914 -- object (SPARK RM 6.9(19)).
916 if Yields_Synchronized_Object (Obj_Typ) then
917 Error_Msg_N ("ghost object & cannot be synchronized", Obj_Id);
919 -- A Ghost object cannot be effectively volatile (SPARK RM 6.9(7) and
920 -- SPARK RM 6.9(19)).
922 elsif Is_Effectively_Volatile (Obj_Id) then
923 Error_Msg_N ("ghost object & cannot be volatile", Obj_Id);
925 -- A Ghost object cannot be imported or exported (SPARK RM 6.9(7)).
926 -- One exception to this is the object that represents the dispatch
927 -- table of a Ghost tagged type, as the symbol needs to be exported.
929 elsif Is_Exported (Obj_Id) then
930 Error_Msg_N ("ghost object & cannot be exported", Obj_Id);
932 elsif Is_Imported (Obj_Id) then
933 Error_Msg_N ("ghost object & cannot be imported", Obj_Id);
934 end if;
935 end if;
937 -- Restore the SPARK_Mode of the enclosing context after all delayed
938 -- pragmas have been analyzed.
940 Restore_SPARK_Mode (Saved_SM, Saved_SMP);
941 end Analyze_Object_Contract;
943 -----------------------------------
944 -- Analyze_Package_Body_Contract --
945 -----------------------------------
947 -- WARNING: This routine manages SPARK regions. Return statements must be
948 -- replaced by gotos which jump to the end of the routine and restore the
949 -- SPARK mode.
951 procedure Analyze_Package_Body_Contract
952 (Body_Id : Entity_Id;
953 Freeze_Id : Entity_Id := Empty)
955 Body_Decl : constant Node_Id := Unit_Declaration_Node (Body_Id);
956 Items : constant Node_Id := Contract (Body_Id);
957 Spec_Id : constant Entity_Id := Spec_Entity (Body_Id);
959 Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
960 Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
961 -- Save the SPARK_Mode-related data to restore on exit
963 Ref_State : Node_Id;
965 begin
966 -- Do not analyze a contract multiple times
968 if Present (Items) then
969 if Analyzed (Items) then
970 return;
971 else
972 Set_Analyzed (Items);
973 end if;
974 end if;
976 -- Due to the timing of contract analysis, delayed pragmas may be
977 -- subject to the wrong SPARK_Mode, usually that of the enclosing
978 -- context. To remedy this, restore the original SPARK_Mode of the
979 -- related package body.
981 Set_SPARK_Mode (Body_Id);
983 Ref_State := Get_Pragma (Body_Id, Pragma_Refined_State);
985 -- The analysis of pragma Refined_State detects whether the spec has
986 -- abstract states available for refinement.
988 if Present (Ref_State) then
989 Analyze_Refined_State_In_Decl_Part (Ref_State, Freeze_Id);
990 end if;
992 -- Restore the SPARK_Mode of the enclosing context after all delayed
993 -- pragmas have been analyzed.
995 Restore_SPARK_Mode (Saved_SM, Saved_SMP);
997 -- Capture all global references in a generic package body now that the
998 -- contract has been analyzed.
1000 if Is_Generic_Declaration_Or_Body (Body_Decl) then
1001 Save_Global_References_In_Contract
1002 (Templ => Original_Node (Body_Decl),
1003 Gen_Id => Spec_Id);
1004 end if;
1005 end Analyze_Package_Body_Contract;
1007 ------------------------------
1008 -- Analyze_Package_Contract --
1009 ------------------------------
1011 -- WARNING: This routine manages SPARK regions. Return statements must be
1012 -- replaced by gotos which jump to the end of the routine and restore the
1013 -- SPARK mode.
1015 procedure Analyze_Package_Contract (Pack_Id : Entity_Id) is
1016 Items : constant Node_Id := Contract (Pack_Id);
1017 Pack_Decl : constant Node_Id := Unit_Declaration_Node (Pack_Id);
1019 Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
1020 Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
1021 -- Save the SPARK_Mode-related data to restore on exit
1023 Init : Node_Id := Empty;
1024 Init_Cond : Node_Id := Empty;
1025 Prag : Node_Id;
1026 Prag_Nam : Name_Id;
1028 begin
1029 -- Do not analyze a contract multiple times
1031 if Present (Items) then
1032 if Analyzed (Items) then
1033 return;
1034 else
1035 Set_Analyzed (Items);
1036 end if;
1037 end if;
1039 -- Due to the timing of contract analysis, delayed pragmas may be
1040 -- subject to the wrong SPARK_Mode, usually that of the enclosing
1041 -- context. To remedy this, restore the original SPARK_Mode of the
1042 -- related package.
1044 Set_SPARK_Mode (Pack_Id);
1046 if Present (Items) then
1048 -- Locate and store pragmas Initial_Condition and Initializes, since
1049 -- their order of analysis matters.
1051 Prag := Classifications (Items);
1052 while Present (Prag) loop
1053 Prag_Nam := Pragma_Name (Prag);
1055 if Prag_Nam = Name_Initial_Condition then
1056 Init_Cond := Prag;
1058 elsif Prag_Nam = Name_Initializes then
1059 Init := Prag;
1060 end if;
1062 Prag := Next_Pragma (Prag);
1063 end loop;
1065 -- Analyze the initialization-related pragmas. Initializes must come
1066 -- before Initial_Condition due to item dependencies.
1068 if Present (Init) then
1069 Analyze_Initializes_In_Decl_Part (Init);
1070 end if;
1072 if Present (Init_Cond) then
1073 Analyze_Initial_Condition_In_Decl_Part (Init_Cond);
1074 end if;
1075 end if;
1077 -- Check whether the lack of indicator Part_Of agrees with the placement
1078 -- of the package instantiation with respect to the state space.
1080 if Is_Generic_Instance (Pack_Id) then
1081 Prag := Get_Pragma (Pack_Id, Pragma_Part_Of);
1083 if No (Prag) then
1084 Check_Missing_Part_Of (Pack_Id);
1085 end if;
1086 end if;
1088 -- Restore the SPARK_Mode of the enclosing context after all delayed
1089 -- pragmas have been analyzed.
1091 Restore_SPARK_Mode (Saved_SM, Saved_SMP);
1093 -- Capture all global references in a generic package now that the
1094 -- contract has been analyzed.
1096 if Is_Generic_Declaration_Or_Body (Pack_Decl) then
1097 Save_Global_References_In_Contract
1098 (Templ => Original_Node (Pack_Decl),
1099 Gen_Id => Pack_Id);
1100 end if;
1101 end Analyze_Package_Contract;
1103 --------------------------------
1104 -- Analyze_Protected_Contract --
1105 --------------------------------
1107 procedure Analyze_Protected_Contract (Prot_Id : Entity_Id) is
1108 Items : constant Node_Id := Contract (Prot_Id);
1110 begin
1111 -- Do not analyze a contract multiple times
1113 if Present (Items) then
1114 if Analyzed (Items) then
1115 return;
1116 else
1117 Set_Analyzed (Items);
1118 end if;
1119 end if;
1120 end Analyze_Protected_Contract;
1122 -------------------------------------------
1123 -- Analyze_Subprogram_Body_Stub_Contract --
1124 -------------------------------------------
1126 procedure Analyze_Subprogram_Body_Stub_Contract (Stub_Id : Entity_Id) is
1127 Stub_Decl : constant Node_Id := Parent (Parent (Stub_Id));
1128 Spec_Id : constant Entity_Id := Corresponding_Spec_Of_Stub (Stub_Decl);
1130 begin
1131 -- A subprogram body stub may act as its own spec or as the completion
1132 -- of a previous declaration. Depending on the context, the contract of
1133 -- the stub may contain two sets of pragmas.
1135 -- The stub is a completion, the applicable pragmas are:
1136 -- Refined_Depends
1137 -- Refined_Global
1139 if Present (Spec_Id) then
1140 Analyze_Entry_Or_Subprogram_Body_Contract (Stub_Id);
1142 -- The stub acts as its own spec, the applicable pragmas are:
1143 -- Contract_Cases
1144 -- Depends
1145 -- Global
1146 -- Postcondition
1147 -- Precondition
1148 -- Test_Case
1150 else
1151 Analyze_Entry_Or_Subprogram_Contract (Stub_Id);
1152 end if;
1153 end Analyze_Subprogram_Body_Stub_Contract;
1155 ---------------------------
1156 -- Analyze_Task_Contract --
1157 ---------------------------
1159 -- WARNING: This routine manages SPARK regions. Return statements must be
1160 -- replaced by gotos which jump to the end of the routine and restore the
1161 -- SPARK mode.
1163 procedure Analyze_Task_Contract (Task_Id : Entity_Id) is
1164 Items : constant Node_Id := Contract (Task_Id);
1166 Saved_SM : constant SPARK_Mode_Type := SPARK_Mode;
1167 Saved_SMP : constant Node_Id := SPARK_Mode_Pragma;
1168 -- Save the SPARK_Mode-related data to restore on exit
1170 Prag : Node_Id;
1172 begin
1173 -- Do not analyze a contract multiple times
1175 if Present (Items) then
1176 if Analyzed (Items) then
1177 return;
1178 else
1179 Set_Analyzed (Items);
1180 end if;
1181 end if;
1183 -- Due to the timing of contract analysis, delayed pragmas may be
1184 -- subject to the wrong SPARK_Mode, usually that of the enclosing
1185 -- context. To remedy this, restore the original SPARK_Mode of the
1186 -- related task unit.
1188 Set_SPARK_Mode (Task_Id);
1190 -- Analyze Global first, as Depends may mention items classified in the
1191 -- global categorization.
1193 Prag := Get_Pragma (Task_Id, Pragma_Global);
1195 if Present (Prag) then
1196 Analyze_Global_In_Decl_Part (Prag);
1197 end if;
1199 -- Depends must be analyzed after Global in order to see the modes of
1200 -- all global items.
1202 Prag := Get_Pragma (Task_Id, Pragma_Depends);
1204 if Present (Prag) then
1205 Analyze_Depends_In_Decl_Part (Prag);
1206 end if;
1208 -- Restore the SPARK_Mode of the enclosing context after all delayed
1209 -- pragmas have been analyzed.
1211 Restore_SPARK_Mode (Saved_SM, Saved_SMP);
1212 end Analyze_Task_Contract;
1214 -------------------------------------------------
1215 -- Build_And_Analyze_Contract_Only_Subprograms --
1216 -------------------------------------------------
1218 procedure Build_And_Analyze_Contract_Only_Subprograms (L : List_Id) is
1219 procedure Analyze_Contract_Only_Subprograms;
1220 -- Analyze the contract-only subprograms of L
1222 procedure Append_Contract_Only_Subprograms (Subp_List : List_Id);
1223 -- Append the contract-only bodies of Subp_List to its declarations list
1225 function Build_Contract_Only_Subprogram (E : Entity_Id) return Node_Id;
1226 -- If E is an entity for a non-imported subprogram specification with
1227 -- pre/postconditions and we are compiling with CodePeer mode, then
1228 -- this procedure will create a wrapper to help Gnat2scil process its
1229 -- contracts. Return Empty if the wrapper cannot be built.
1231 function Build_Contract_Only_Subprograms (L : List_Id) return List_Id;
1232 -- Build the contract-only subprograms of all eligible subprograms found
1233 -- in list L.
1235 function Has_Private_Declarations (N : Node_Id) return Boolean;
1236 -- Return True for package specs, task definitions, and protected type
1237 -- definitions whose list of private declarations is not empty.
1239 ---------------------------------------
1240 -- Analyze_Contract_Only_Subprograms --
1241 ---------------------------------------
1243 procedure Analyze_Contract_Only_Subprograms is
1244 procedure Analyze_Contract_Only_Bodies;
1245 -- Analyze all the contract-only bodies of L
1247 ----------------------------------
1248 -- Analyze_Contract_Only_Bodies --
1249 ----------------------------------
1251 procedure Analyze_Contract_Only_Bodies is
1252 Decl : Node_Id;
1254 begin
1255 Decl := First (L);
1256 while Present (Decl) loop
1257 if Nkind (Decl) = N_Subprogram_Body
1258 and then Is_Contract_Only_Body
1259 (Defining_Unit_Name (Specification (Decl)))
1260 then
1261 Analyze (Decl);
1262 end if;
1264 Next (Decl);
1265 end loop;
1266 end Analyze_Contract_Only_Bodies;
1268 -- Start of processing for Analyze_Contract_Only_Subprograms
1270 begin
1271 if Ekind (Current_Scope) /= E_Package then
1272 Analyze_Contract_Only_Bodies;
1274 else
1275 declare
1276 Pkg_Spec : constant Node_Id :=
1277 Package_Specification (Current_Scope);
1279 begin
1280 if not Has_Private_Declarations (Pkg_Spec) then
1281 Analyze_Contract_Only_Bodies;
1283 -- For packages with private declarations, the contract-only
1284 -- bodies of subprograms defined in the visible part of the
1285 -- package are added to its private declarations (to ensure
1286 -- that they do not cause premature freezing of types and also
1287 -- that they are analyzed with proper visibility). Hence they
1288 -- will be analyzed later.
1290 elsif Visible_Declarations (Pkg_Spec) = L then
1291 null;
1293 elsif Private_Declarations (Pkg_Spec) = L then
1294 Analyze_Contract_Only_Bodies;
1295 end if;
1296 end;
1297 end if;
1298 end Analyze_Contract_Only_Subprograms;
1300 --------------------------------------
1301 -- Append_Contract_Only_Subprograms --
1302 --------------------------------------
1304 procedure Append_Contract_Only_Subprograms (Subp_List : List_Id) is
1305 begin
1306 if No (Subp_List) then
1307 return;
1308 end if;
1310 if Ekind (Current_Scope) /= E_Package then
1311 Append_List (Subp_List, To => L);
1313 else
1314 declare
1315 Pkg_Spec : constant Node_Id :=
1316 Package_Specification (Current_Scope);
1318 begin
1319 if not Has_Private_Declarations (Pkg_Spec) then
1320 Append_List (Subp_List, To => L);
1322 -- If the package has private declarations then append them to
1323 -- its private declarations; they will be analyzed when the
1324 -- contracts of its private declarations are analyzed.
1326 else
1327 Append_List
1328 (List => Subp_List,
1329 To => Private_Declarations (Pkg_Spec));
1330 end if;
1331 end;
1332 end if;
1333 end Append_Contract_Only_Subprograms;
1335 ------------------------------------
1336 -- Build_Contract_Only_Subprogram --
1337 ------------------------------------
1339 -- This procedure takes care of building a wrapper to generate better
1340 -- analysis results in the case of a call to a subprogram whose body
1341 -- is unavailable to CodePeer but whose specification includes Pre/Post
1342 -- conditions. The body might be unavailable for any of a number or
1343 -- reasons (it is imported, the .adb file is simply missing, or the
1344 -- subprogram might be subject to an Annotate (CodePeer, Skip_Analysis)
1345 -- pragma). The built subprogram has the following contents:
1346 -- * check preconditions
1347 -- * call the subprogram
1348 -- * check postconditions
1350 function Build_Contract_Only_Subprogram (E : Entity_Id) return Node_Id is
1351 Loc : constant Source_Ptr := Sloc (E);
1353 Missing_Body_Name : constant Name_Id :=
1354 New_External_Name (Chars (E), "__missing_body");
1356 function Build_Missing_Body_Decls return List_Id;
1357 -- Build the declaration of the missing body subprogram and its
1358 -- corresponding pragma Import.
1360 function Build_Missing_Body_Subprogram_Call return Node_Id;
1361 -- Build the call to the missing body subprogram
1363 function Skip_Contract_Only_Subprogram (E : Entity_Id) return Boolean;
1364 -- Return True for cases where the wrapper is not needed or we cannot
1365 -- build it.
1367 ------------------------------
1368 -- Build_Missing_Body_Decls --
1369 ------------------------------
1371 function Build_Missing_Body_Decls return List_Id is
1372 Spec : constant Node_Id := Declaration_Node (E);
1373 Decl : Node_Id;
1374 Prag : Node_Id;
1376 begin
1377 Decl :=
1378 Make_Subprogram_Declaration (Loc, Copy_Subprogram_Spec (Spec));
1379 Set_Chars (Defining_Entity (Decl), Missing_Body_Name);
1381 Prag :=
1382 Make_Pragma (Loc,
1383 Chars => Name_Import,
1384 Pragma_Argument_Associations => New_List (
1385 Make_Pragma_Argument_Association (Loc,
1386 Expression => Make_Identifier (Loc, Name_Ada)),
1388 Make_Pragma_Argument_Association (Loc,
1389 Expression => Make_Identifier (Loc, Missing_Body_Name))));
1391 return New_List (Decl, Prag);
1392 end Build_Missing_Body_Decls;
1394 ----------------------------------------
1395 -- Build_Missing_Body_Subprogram_Call --
1396 ----------------------------------------
1398 function Build_Missing_Body_Subprogram_Call return Node_Id is
1399 Forml : Entity_Id;
1400 Parms : List_Id;
1402 begin
1403 Parms := New_List;
1405 -- Build parameter list that we need
1407 Forml := First_Formal (E);
1408 while Present (Forml) loop
1409 Append_To (Parms, Make_Identifier (Loc, Chars (Forml)));
1410 Next_Formal (Forml);
1411 end loop;
1413 -- Build the call to the missing body subprogram
1415 if Ekind_In (E, E_Function, E_Generic_Function) then
1416 return
1417 Make_Simple_Return_Statement (Loc,
1418 Expression =>
1419 Make_Function_Call (Loc,
1420 Name =>
1421 Make_Identifier (Loc, Missing_Body_Name),
1422 Parameter_Associations => Parms));
1424 else
1425 return
1426 Make_Procedure_Call_Statement (Loc,
1427 Name =>
1428 Make_Identifier (Loc, Missing_Body_Name),
1429 Parameter_Associations => Parms);
1430 end if;
1431 end Build_Missing_Body_Subprogram_Call;
1433 -----------------------------------
1434 -- Skip_Contract_Only_Subprogram --
1435 -----------------------------------
1437 function Skip_Contract_Only_Subprogram
1438 (E : Entity_Id) return Boolean
1440 function Depends_On_Enclosing_Private_Type return Boolean;
1441 -- Return True if some formal of E (or its return type) are
1442 -- private types defined in an enclosing package.
1444 function Some_Enclosing_Package_Has_Private_Decls return Boolean;
1445 -- Return True if some enclosing package of the current scope has
1446 -- private declarations.
1448 ---------------------------------------
1449 -- Depends_On_Enclosing_Private_Type --
1450 ---------------------------------------
1452 function Depends_On_Enclosing_Private_Type return Boolean is
1453 function Defined_In_Enclosing_Package
1454 (Typ : Entity_Id) return Boolean;
1455 -- Return True if Typ is an entity defined in an enclosing
1456 -- package of the current scope.
1458 ----------------------------------
1459 -- Defined_In_Enclosing_Package --
1460 ----------------------------------
1462 function Defined_In_Enclosing_Package
1463 (Typ : Entity_Id) return Boolean
1465 Scop : Entity_Id := Scope (Current_Scope);
1467 begin
1468 while Scop /= Scope (Typ)
1469 and then not Is_Compilation_Unit (Scop)
1470 loop
1471 Scop := Scope (Scop);
1472 end loop;
1474 return Scop = Scope (Typ);
1475 end Defined_In_Enclosing_Package;
1477 -- Local variables
1479 Param_E : Entity_Id;
1480 Typ : Entity_Id;
1482 -- Start of processing for Depends_On_Enclosing_Private_Type
1484 begin
1485 Param_E := First_Entity (E);
1486 while Present (Param_E) loop
1487 Typ := Etype (Param_E);
1489 if Is_Private_Type (Typ)
1490 and then Defined_In_Enclosing_Package (Typ)
1491 then
1492 return True;
1493 end if;
1495 Next_Entity (Param_E);
1496 end loop;
1498 return
1499 Ekind (E) = E_Function
1500 and then Is_Private_Type (Etype (E))
1501 and then Defined_In_Enclosing_Package (Etype (E));
1502 end Depends_On_Enclosing_Private_Type;
1504 ----------------------------------------------
1505 -- Some_Enclosing_Package_Has_Private_Decls --
1506 ----------------------------------------------
1508 function Some_Enclosing_Package_Has_Private_Decls return Boolean is
1509 Scop : Entity_Id := Current_Scope;
1510 Pkg_Spec : Node_Id := Package_Specification (Scop);
1512 begin
1513 loop
1514 if Ekind (Scop) = E_Package
1515 and then Has_Private_Declarations
1516 (Package_Specification (Scop))
1517 then
1518 Pkg_Spec := Package_Specification (Scop);
1519 end if;
1521 exit when Is_Compilation_Unit (Scop);
1522 Scop := Scope (Scop);
1523 end loop;
1525 return Pkg_Spec /= Package_Specification (Current_Scope);
1526 end Some_Enclosing_Package_Has_Private_Decls;
1528 -- Start of processing for Skip_Contract_Only_Subprogram
1530 begin
1531 if not CodePeer_Mode
1532 or else Inside_A_Generic
1533 or else not Is_Subprogram (E)
1534 or else Is_Abstract_Subprogram (E)
1535 or else Is_Imported (E)
1536 or else No (Contract (E))
1537 or else No (Pre_Post_Conditions (Contract (E)))
1538 or else Is_Contract_Only_Body (E)
1539 or else Convention (E) = Convention_Protected
1540 then
1541 return True;
1543 -- We do not support building the contract-only subprogram if E
1544 -- is a subprogram declared in a nested package that has some
1545 -- formal or return type depending on a private type defined in
1546 -- an enclosing package.
1548 elsif Ekind (Current_Scope) = E_Package
1549 and then Some_Enclosing_Package_Has_Private_Decls
1550 and then Depends_On_Enclosing_Private_Type
1551 then
1552 if Debug_Flag_Dot_KK then
1553 declare
1554 Saved_Mode : constant Warning_Mode_Type := Warning_Mode;
1556 begin
1557 -- Warnings are disabled by default under CodePeer_Mode
1558 -- (see switch-c). Enable them temporarily.
1560 Warning_Mode := Normal;
1561 Error_Msg_N
1562 ("cannot generate contract-only subprogram?", E);
1563 Warning_Mode := Saved_Mode;
1564 end;
1565 end if;
1567 return True;
1568 end if;
1570 return False;
1571 end Skip_Contract_Only_Subprogram;
1573 -- Start of processing for Build_Contract_Only_Subprogram
1575 begin
1576 -- Test cases where the wrapper is not needed and cases where we
1577 -- cannot build it.
1579 if Skip_Contract_Only_Subprogram (E) then
1580 return Empty;
1581 end if;
1583 -- Note on calls to Copy_Separate_Tree. The trees we are copying
1584 -- here are fully analyzed, but we definitely want fully syntactic
1585 -- unanalyzed trees in the body we construct, so that the analysis
1586 -- generates the right visibility, and that is exactly what the
1587 -- calls to Copy_Separate_Tree give us.
1589 declare
1590 Name : constant Name_Id :=
1591 New_External_Name (Chars (E), "__contract_only");
1592 Id : Entity_Id;
1593 Bod : Node_Id;
1595 begin
1596 Bod :=
1597 Make_Subprogram_Body (Loc,
1598 Specification =>
1599 Copy_Subprogram_Spec (Declaration_Node (E)),
1600 Declarations =>
1601 Build_Missing_Body_Decls,
1602 Handled_Statement_Sequence =>
1603 Make_Handled_Sequence_Of_Statements (Loc,
1604 Statements => New_List (
1605 Build_Missing_Body_Subprogram_Call),
1606 End_Label => Make_Identifier (Loc, Name)));
1608 Id := Defining_Unit_Name (Specification (Bod));
1610 -- Copy only the pre/postconditions of the original contract
1611 -- since it is what we need, but also because pragmas stored in
1612 -- the other fields have N_Pragmas with N_Aspect_Specifications
1613 -- that reference their associated pragma (thus causing an endless
1614 -- loop when trying to copy the subtree).
1616 declare
1617 New_Contract : constant Node_Id := Make_Contract (Sloc (E));
1619 begin
1620 Set_Pre_Post_Conditions (New_Contract,
1621 Copy_Separate_Tree (Pre_Post_Conditions (Contract (E))));
1622 Set_Contract (Id, New_Contract);
1623 end;
1625 -- Fix the name of this new subprogram and link the original
1626 -- subprogram with its Contract_Only_Body subprogram.
1628 Set_Chars (Id, Name);
1629 Set_Is_Contract_Only_Body (Id);
1630 Set_Contract_Only_Body (E, Id);
1632 return Bod;
1633 end;
1634 end Build_Contract_Only_Subprogram;
1636 -------------------------------------
1637 -- Build_Contract_Only_Subprograms --
1638 -------------------------------------
1640 function Build_Contract_Only_Subprograms (L : List_Id) return List_Id is
1641 Decl : Node_Id;
1642 New_Subp : Node_Id;
1643 Result : List_Id := No_List;
1644 Subp_Id : Entity_Id;
1646 begin
1647 Decl := First (L);
1648 while Present (Decl) loop
1649 if Nkind (Decl) = N_Subprogram_Declaration then
1650 Subp_Id := Defining_Unit_Name (Specification (Decl));
1651 New_Subp := Build_Contract_Only_Subprogram (Subp_Id);
1653 if Present (New_Subp) then
1654 if No (Result) then
1655 Result := New_List;
1656 end if;
1658 Append_To (Result, New_Subp);
1659 end if;
1660 end if;
1662 Next (Decl);
1663 end loop;
1665 return Result;
1666 end Build_Contract_Only_Subprograms;
1668 ------------------------------
1669 -- Has_Private_Declarations --
1670 ------------------------------
1672 function Has_Private_Declarations (N : Node_Id) return Boolean is
1673 begin
1674 if not Nkind_In (N, N_Package_Specification,
1675 N_Protected_Definition,
1676 N_Task_Definition)
1677 then
1678 return False;
1679 else
1680 return
1681 Present (Private_Declarations (N))
1682 and then Is_Non_Empty_List (Private_Declarations (N));
1683 end if;
1684 end Has_Private_Declarations;
1686 -- Local variables
1688 Subp_List : List_Id;
1690 -- Start of processing for Build_And_Analyze_Contract_Only_Subprograms
1692 begin
1693 Subp_List := Build_Contract_Only_Subprograms (L);
1694 Append_Contract_Only_Subprograms (Subp_List);
1695 Analyze_Contract_Only_Subprograms;
1696 end Build_And_Analyze_Contract_Only_Subprograms;
1698 -----------------------------
1699 -- Create_Generic_Contract --
1700 -----------------------------
1702 procedure Create_Generic_Contract (Unit : Node_Id) is
1703 Templ : constant Node_Id := Original_Node (Unit);
1704 Templ_Id : constant Entity_Id := Defining_Entity (Templ);
1706 procedure Add_Generic_Contract_Pragma (Prag : Node_Id);
1707 -- Add a single contract-related source pragma Prag to the contract of
1708 -- generic template Templ_Id.
1710 ---------------------------------
1711 -- Add_Generic_Contract_Pragma --
1712 ---------------------------------
1714 procedure Add_Generic_Contract_Pragma (Prag : Node_Id) is
1715 Prag_Templ : Node_Id;
1717 begin
1718 -- Mark the pragma to prevent the premature capture of global
1719 -- references when capturing global references of the context
1720 -- (see Save_References_In_Pragma).
1722 Set_Is_Generic_Contract_Pragma (Prag);
1724 -- Pragmas that apply to a generic subprogram declaration are not
1725 -- part of the semantic structure of the generic template:
1727 -- generic
1728 -- procedure Example (Formal : Integer);
1729 -- pragma Precondition (Formal > 0);
1731 -- Create a generic template for such pragmas and link the template
1732 -- of the pragma with the generic template.
1734 if Nkind (Templ) = N_Generic_Subprogram_Declaration then
1735 Rewrite
1736 (Prag, Copy_Generic_Node (Prag, Empty, Instantiating => False));
1737 Prag_Templ := Original_Node (Prag);
1739 Set_Is_Generic_Contract_Pragma (Prag_Templ);
1740 Add_Contract_Item (Prag_Templ, Templ_Id);
1742 -- Otherwise link the pragma with the generic template
1744 else
1745 Add_Contract_Item (Prag, Templ_Id);
1746 end if;
1747 end Add_Generic_Contract_Pragma;
1749 -- Local variables
1751 Context : constant Node_Id := Parent (Unit);
1752 Decl : Node_Id := Empty;
1754 -- Start of processing for Create_Generic_Contract
1756 begin
1757 -- A generic package declaration carries contract-related source pragmas
1758 -- in its visible declarations.
1760 if Nkind (Templ) = N_Generic_Package_Declaration then
1761 Set_Ekind (Templ_Id, E_Generic_Package);
1763 if Present (Visible_Declarations (Specification (Templ))) then
1764 Decl := First (Visible_Declarations (Specification (Templ)));
1765 end if;
1767 -- A generic package body carries contract-related source pragmas in its
1768 -- declarations.
1770 elsif Nkind (Templ) = N_Package_Body then
1771 Set_Ekind (Templ_Id, E_Package_Body);
1773 if Present (Declarations (Templ)) then
1774 Decl := First (Declarations (Templ));
1775 end if;
1777 -- Generic subprogram declaration
1779 elsif Nkind (Templ) = N_Generic_Subprogram_Declaration then
1780 if Nkind (Specification (Templ)) = N_Function_Specification then
1781 Set_Ekind (Templ_Id, E_Generic_Function);
1782 else
1783 Set_Ekind (Templ_Id, E_Generic_Procedure);
1784 end if;
1786 -- When the generic subprogram acts as a compilation unit, inspect
1787 -- the Pragmas_After list for contract-related source pragmas.
1789 if Nkind (Context) = N_Compilation_Unit then
1790 if Present (Aux_Decls_Node (Context))
1791 and then Present (Pragmas_After (Aux_Decls_Node (Context)))
1792 then
1793 Decl := First (Pragmas_After (Aux_Decls_Node (Context)));
1794 end if;
1796 -- Otherwise inspect the successive declarations for contract-related
1797 -- source pragmas.
1799 else
1800 Decl := Next (Unit);
1801 end if;
1803 -- A generic subprogram body carries contract-related source pragmas in
1804 -- its declarations.
1806 elsif Nkind (Templ) = N_Subprogram_Body then
1807 Set_Ekind (Templ_Id, E_Subprogram_Body);
1809 if Present (Declarations (Templ)) then
1810 Decl := First (Declarations (Templ));
1811 end if;
1812 end if;
1814 -- Inspect the relevant declarations looking for contract-related source
1815 -- pragmas and add them to the contract of the generic unit.
1817 while Present (Decl) loop
1818 if Comes_From_Source (Decl) then
1819 if Nkind (Decl) = N_Pragma then
1821 -- The source pragma is a contract annotation
1823 if Is_Contract_Annotation (Decl) then
1824 Add_Generic_Contract_Pragma (Decl);
1825 end if;
1827 -- The region where a contract-related source pragma may appear
1828 -- ends with the first source non-pragma declaration or statement.
1830 else
1831 exit;
1832 end if;
1833 end if;
1835 Next (Decl);
1836 end loop;
1837 end Create_Generic_Contract;
1839 --------------------------------
1840 -- Expand_Subprogram_Contract --
1841 --------------------------------
1843 procedure Expand_Subprogram_Contract (Body_Id : Entity_Id) is
1844 Body_Decl : constant Node_Id := Unit_Declaration_Node (Body_Id);
1845 Spec_Id : constant Entity_Id := Corresponding_Spec (Body_Decl);
1847 procedure Add_Invariant_And_Predicate_Checks
1848 (Subp_Id : Entity_Id;
1849 Stmts : in out List_Id;
1850 Result : out Node_Id);
1851 -- Process the result of function Subp_Id (if applicable) and all its
1852 -- formals. Add invariant and predicate checks where applicable. The
1853 -- routine appends all the checks to list Stmts. If Subp_Id denotes a
1854 -- function, Result contains the entity of parameter _Result, to be
1855 -- used in the creation of procedure _Postconditions.
1857 procedure Append_Enabled_Item (Item : Node_Id; List : in out List_Id);
1858 -- Append a node to a list. If there is no list, create a new one. When
1859 -- the item denotes a pragma, it is added to the list only when it is
1860 -- enabled.
1862 procedure Build_Postconditions_Procedure
1863 (Subp_Id : Entity_Id;
1864 Stmts : List_Id;
1865 Result : Entity_Id);
1866 -- Create the body of procedure _Postconditions which handles various
1867 -- assertion actions on exit from subprogram Subp_Id. Stmts is the list
1868 -- of statements to be checked on exit. Parameter Result is the entity
1869 -- of parameter _Result when Subp_Id denotes a function.
1871 procedure Process_Contract_Cases (Stmts : in out List_Id);
1872 -- Process pragma Contract_Cases. This routine prepends items to the
1873 -- body declarations and appends items to list Stmts.
1875 procedure Process_Postconditions (Stmts : in out List_Id);
1876 -- Collect all [inherited] spec and body postconditions and accumulate
1877 -- their pragma Check equivalents in list Stmts.
1879 procedure Process_Preconditions;
1880 -- Collect all [inherited] spec and body preconditions and prepend their
1881 -- pragma Check equivalents to the declarations of the body.
1883 ----------------------------------------
1884 -- Add_Invariant_And_Predicate_Checks --
1885 ----------------------------------------
1887 procedure Add_Invariant_And_Predicate_Checks
1888 (Subp_Id : Entity_Id;
1889 Stmts : in out List_Id;
1890 Result : out Node_Id)
1892 procedure Add_Invariant_Access_Checks (Id : Entity_Id);
1893 -- Id denotes the return value of a function or a formal parameter.
1894 -- Add an invariant check if the type of Id is access to a type with
1895 -- invariants. The routine appends the generated code to Stmts.
1897 function Invariant_Checks_OK (Typ : Entity_Id) return Boolean;
1898 -- Determine whether type Typ can benefit from invariant checks. To
1899 -- qualify, the type must have a non-null invariant procedure and
1900 -- subprogram Subp_Id must appear visible from the point of view of
1901 -- the type.
1903 ---------------------------------
1904 -- Add_Invariant_Access_Checks --
1905 ---------------------------------
1907 procedure Add_Invariant_Access_Checks (Id : Entity_Id) is
1908 Loc : constant Source_Ptr := Sloc (Body_Decl);
1909 Ref : Node_Id;
1910 Typ : Entity_Id;
1912 begin
1913 Typ := Etype (Id);
1915 if Is_Access_Type (Typ) and then not Is_Access_Constant (Typ) then
1916 Typ := Designated_Type (Typ);
1918 if Invariant_Checks_OK (Typ) then
1919 Ref :=
1920 Make_Explicit_Dereference (Loc,
1921 Prefix => New_Occurrence_Of (Id, Loc));
1922 Set_Etype (Ref, Typ);
1924 -- Generate:
1925 -- if <Id> /= null then
1926 -- <invariant_call (<Ref>)>
1927 -- end if;
1929 Append_Enabled_Item
1930 (Item =>
1931 Make_If_Statement (Loc,
1932 Condition =>
1933 Make_Op_Ne (Loc,
1934 Left_Opnd => New_Occurrence_Of (Id, Loc),
1935 Right_Opnd => Make_Null (Loc)),
1936 Then_Statements => New_List (
1937 Make_Invariant_Call (Ref))),
1938 List => Stmts);
1939 end if;
1940 end if;
1941 end Add_Invariant_Access_Checks;
1943 -------------------------
1944 -- Invariant_Checks_OK --
1945 -------------------------
1947 function Invariant_Checks_OK (Typ : Entity_Id) return Boolean is
1948 function Has_Public_Visibility_Of_Subprogram return Boolean;
1949 -- Determine whether type Typ has public visibility of subprogram
1950 -- Subp_Id.
1952 -----------------------------------------
1953 -- Has_Public_Visibility_Of_Subprogram --
1954 -----------------------------------------
1956 function Has_Public_Visibility_Of_Subprogram return Boolean is
1957 Subp_Decl : constant Node_Id := Unit_Declaration_Node (Subp_Id);
1959 begin
1960 -- An Initialization procedure must be considered visible even
1961 -- though it is internally generated.
1963 if Is_Init_Proc (Defining_Entity (Subp_Decl)) then
1964 return True;
1966 elsif Ekind (Scope (Typ)) /= E_Package then
1967 return False;
1969 -- Internally generated code is never publicly visible except
1970 -- for a subprogram that is the implementation of an expression
1971 -- function. In that case the visibility is determined by the
1972 -- last check.
1974 elsif not Comes_From_Source (Subp_Decl)
1975 and then
1976 (Nkind (Original_Node (Subp_Decl)) /= N_Expression_Function
1977 or else not
1978 Comes_From_Source (Defining_Entity (Subp_Decl)))
1979 then
1980 return False;
1982 -- Determine whether the subprogram is declared in the visible
1983 -- declarations of the package containing the type, or in the
1984 -- visible declaration of a child unit of that package.
1986 else
1987 declare
1988 Decls : constant List_Id :=
1989 List_Containing (Subp_Decl);
1990 Subp_Scope : constant Entity_Id :=
1991 Scope (Defining_Entity (Subp_Decl));
1992 Typ_Scope : constant Entity_Id := Scope (Typ);
1994 begin
1995 return
1996 Decls = Visible_Declarations
1997 (Specification (Unit_Declaration_Node (Typ_Scope)))
1999 or else
2000 (Ekind (Subp_Scope) = E_Package
2001 and then Typ_Scope /= Subp_Scope
2002 and then Is_Child_Unit (Subp_Scope)
2003 and then
2004 Is_Ancestor_Package (Typ_Scope, Subp_Scope)
2005 and then
2006 Decls = Visible_Declarations
2007 (Specification
2008 (Unit_Declaration_Node (Subp_Scope))));
2009 end;
2010 end if;
2011 end Has_Public_Visibility_Of_Subprogram;
2013 -- Start of processing for Invariant_Checks_OK
2015 begin
2016 return
2017 Has_Invariants (Typ)
2018 and then Present (Invariant_Procedure (Typ))
2019 and then not Has_Null_Body (Invariant_Procedure (Typ))
2020 and then Has_Public_Visibility_Of_Subprogram;
2021 end Invariant_Checks_OK;
2023 -- Local variables
2025 Loc : constant Source_Ptr := Sloc (Body_Decl);
2026 -- Source location of subprogram body contract
2028 Formal : Entity_Id;
2029 Typ : Entity_Id;
2031 -- Start of processing for Add_Invariant_And_Predicate_Checks
2033 begin
2034 Result := Empty;
2036 -- Process the result of a function
2038 if Ekind (Subp_Id) = E_Function then
2039 Typ := Etype (Subp_Id);
2041 -- Generate _Result which is used in procedure _Postconditions to
2042 -- verify the return value.
2044 Result := Make_Defining_Identifier (Loc, Name_uResult);
2045 Set_Etype (Result, Typ);
2047 -- Add an invariant check when the return type has invariants and
2048 -- the related function is visible to the outside.
2050 if Invariant_Checks_OK (Typ) then
2051 Append_Enabled_Item
2052 (Item =>
2053 Make_Invariant_Call (New_Occurrence_Of (Result, Loc)),
2054 List => Stmts);
2055 end if;
2057 -- Add an invariant check when the return type is an access to a
2058 -- type with invariants.
2060 Add_Invariant_Access_Checks (Result);
2061 end if;
2063 -- Add invariant and predicates for all formals that qualify
2065 Formal := First_Formal (Subp_Id);
2066 while Present (Formal) loop
2067 Typ := Etype (Formal);
2069 if Ekind (Formal) /= E_In_Parameter
2070 or else Is_Access_Type (Typ)
2071 then
2072 if Invariant_Checks_OK (Typ) then
2073 Append_Enabled_Item
2074 (Item =>
2075 Make_Invariant_Call (New_Occurrence_Of (Formal, Loc)),
2076 List => Stmts);
2077 end if;
2079 Add_Invariant_Access_Checks (Formal);
2081 -- Note: we used to add predicate checks for OUT and IN OUT
2082 -- formals here, but that was misguided, since such checks are
2083 -- performed on the caller side, based on the predicate of the
2084 -- actual, rather than the predicate of the formal.
2086 end if;
2088 Next_Formal (Formal);
2089 end loop;
2090 end Add_Invariant_And_Predicate_Checks;
2092 -------------------------
2093 -- Append_Enabled_Item --
2094 -------------------------
2096 procedure Append_Enabled_Item (Item : Node_Id; List : in out List_Id) is
2097 begin
2098 -- Do not chain ignored or disabled pragmas
2100 if Nkind (Item) = N_Pragma
2101 and then (Is_Ignored (Item) or else Is_Disabled (Item))
2102 then
2103 null;
2105 -- Otherwise, add the item
2107 else
2108 if No (List) then
2109 List := New_List;
2110 end if;
2112 -- If the pragma is a conjunct in a composite postcondition, it
2113 -- has been processed in reverse order. In the postcondition body
2114 -- it must appear before the others.
2116 if Nkind (Item) = N_Pragma
2117 and then From_Aspect_Specification (Item)
2118 and then Split_PPC (Item)
2119 then
2120 Prepend (Item, List);
2121 else
2122 Append (Item, List);
2123 end if;
2124 end if;
2125 end Append_Enabled_Item;
2127 ------------------------------------
2128 -- Build_Postconditions_Procedure --
2129 ------------------------------------
2131 procedure Build_Postconditions_Procedure
2132 (Subp_Id : Entity_Id;
2133 Stmts : List_Id;
2134 Result : Entity_Id)
2136 procedure Insert_Before_First_Source_Declaration (Stmt : Node_Id);
2137 -- Insert node Stmt before the first source declaration of the
2138 -- related subprogram's body. If no such declaration exists, Stmt
2139 -- becomes the last declaration.
2141 --------------------------------------------
2142 -- Insert_Before_First_Source_Declaration --
2143 --------------------------------------------
2145 procedure Insert_Before_First_Source_Declaration (Stmt : Node_Id) is
2146 Decls : constant List_Id := Declarations (Body_Decl);
2147 Decl : Node_Id;
2149 begin
2150 -- Inspect the declarations of the related subprogram body looking
2151 -- for the first source declaration.
2153 if Present (Decls) then
2154 Decl := First (Decls);
2155 while Present (Decl) loop
2156 if Comes_From_Source (Decl) then
2157 Insert_Before (Decl, Stmt);
2158 return;
2159 end if;
2161 Next (Decl);
2162 end loop;
2164 -- If we get there, then the subprogram body lacks any source
2165 -- declarations. The body of _Postconditions now acts as the
2166 -- last declaration.
2168 Append (Stmt, Decls);
2170 -- Ensure that the body has a declaration list
2172 else
2173 Set_Declarations (Body_Decl, New_List (Stmt));
2174 end if;
2175 end Insert_Before_First_Source_Declaration;
2177 -- Local variables
2179 Loc : constant Source_Ptr := Sloc (Body_Decl);
2180 Params : List_Id := No_List;
2181 Proc_Bod : Node_Id;
2182 Proc_Decl : Node_Id;
2183 Proc_Id : Entity_Id;
2184 Proc_Spec : Node_Id;
2186 -- Start of processing for Build_Postconditions_Procedure
2188 begin
2189 -- Nothing to do if there are no actions to check on exit
2191 if No (Stmts) then
2192 return;
2193 end if;
2195 Proc_Id := Make_Defining_Identifier (Loc, Name_uPostconditions);
2196 Set_Debug_Info_Needed (Proc_Id);
2197 Set_Postconditions_Proc (Subp_Id, Proc_Id);
2199 -- Force the front-end inlining of _Postconditions when generating C
2200 -- code, since its body may have references to itypes defined in the
2201 -- enclosing subprogram, which would cause problems for unnesting
2202 -- routines in the absence of inlining.
2204 if Modify_Tree_For_C then
2205 Set_Has_Pragma_Inline (Proc_Id);
2206 Set_Has_Pragma_Inline_Always (Proc_Id);
2207 Set_Is_Inlined (Proc_Id);
2208 end if;
2210 -- The related subprogram is a function: create the specification of
2211 -- parameter _Result.
2213 if Present (Result) then
2214 Params := New_List (
2215 Make_Parameter_Specification (Loc,
2216 Defining_Identifier => Result,
2217 Parameter_Type =>
2218 New_Occurrence_Of (Etype (Result), Loc)));
2219 end if;
2221 Proc_Spec :=
2222 Make_Procedure_Specification (Loc,
2223 Defining_Unit_Name => Proc_Id,
2224 Parameter_Specifications => Params);
2226 Proc_Decl := Make_Subprogram_Declaration (Loc, Proc_Spec);
2228 -- Insert _Postconditions before the first source declaration of the
2229 -- body. This ensures that the body will not cause any premature
2230 -- freezing, as it may mention types:
2232 -- procedure Proc (Obj : Array_Typ) is
2233 -- procedure _postconditions is
2234 -- begin
2235 -- ... Obj ...
2236 -- end _postconditions;
2238 -- subtype T is Array_Typ (Obj'First (1) .. Obj'Last (1));
2239 -- begin
2241 -- In the example above, Obj is of type T but the incorrect placement
2242 -- of _Postconditions will cause a crash in gigi due to an out-of-
2243 -- order reference. The body of _Postconditions must be placed after
2244 -- the declaration of Temp to preserve correct visibility.
2246 Insert_Before_First_Source_Declaration (Proc_Decl);
2247 Analyze (Proc_Decl);
2249 -- Set an explicit End_Label to override the sloc of the implicit
2250 -- RETURN statement, and prevent it from inheriting the sloc of one
2251 -- the postconditions: this would cause confusing debug info to be
2252 -- produced, interfering with coverage-analysis tools.
2254 Proc_Bod :=
2255 Make_Subprogram_Body (Loc,
2256 Specification =>
2257 Copy_Subprogram_Spec (Proc_Spec),
2258 Declarations => Empty_List,
2259 Handled_Statement_Sequence =>
2260 Make_Handled_Sequence_Of_Statements (Loc,
2261 Statements => Stmts,
2262 End_Label => Make_Identifier (Loc, Chars (Proc_Id))));
2264 Insert_After_And_Analyze (Proc_Decl, Proc_Bod);
2265 end Build_Postconditions_Procedure;
2267 ----------------------------
2268 -- Process_Contract_Cases --
2269 ----------------------------
2271 procedure Process_Contract_Cases (Stmts : in out List_Id) is
2272 procedure Process_Contract_Cases_For (Subp_Id : Entity_Id);
2273 -- Process pragma Contract_Cases for subprogram Subp_Id
2275 --------------------------------
2276 -- Process_Contract_Cases_For --
2277 --------------------------------
2279 procedure Process_Contract_Cases_For (Subp_Id : Entity_Id) is
2280 Items : constant Node_Id := Contract (Subp_Id);
2281 Prag : Node_Id;
2283 begin
2284 if Present (Items) then
2285 Prag := Contract_Test_Cases (Items);
2286 while Present (Prag) loop
2287 if Pragma_Name (Prag) = Name_Contract_Cases then
2288 Expand_Pragma_Contract_Cases
2289 (CCs => Prag,
2290 Subp_Id => Subp_Id,
2291 Decls => Declarations (Body_Decl),
2292 Stmts => Stmts);
2293 end if;
2295 Prag := Next_Pragma (Prag);
2296 end loop;
2297 end if;
2298 end Process_Contract_Cases_For;
2300 pragma Unmodified (Stmts);
2301 -- Stmts is passed as IN OUT to signal that the list can be updated,
2302 -- even if the corresponding integer value representing the list does
2303 -- not change.
2305 -- Start of processing for Process_Contract_Cases
2307 begin
2308 Process_Contract_Cases_For (Body_Id);
2310 if Present (Spec_Id) then
2311 Process_Contract_Cases_For (Spec_Id);
2312 end if;
2313 end Process_Contract_Cases;
2315 ----------------------------
2316 -- Process_Postconditions --
2317 ----------------------------
2319 procedure Process_Postconditions (Stmts : in out List_Id) is
2320 procedure Process_Body_Postconditions (Post_Nam : Name_Id);
2321 -- Collect all [refined] postconditions of a specific kind denoted
2322 -- by Post_Nam that belong to the body, and generate pragma Check
2323 -- equivalents in list Stmts.
2325 procedure Process_Spec_Postconditions;
2326 -- Collect all [inherited] postconditions of the spec, and generate
2327 -- pragma Check equivalents in list Stmts.
2329 ---------------------------------
2330 -- Process_Body_Postconditions --
2331 ---------------------------------
2333 procedure Process_Body_Postconditions (Post_Nam : Name_Id) is
2334 Items : constant Node_Id := Contract (Body_Id);
2335 Unit_Decl : constant Node_Id := Parent (Body_Decl);
2336 Decl : Node_Id;
2337 Prag : Node_Id;
2339 begin
2340 -- Process the contract
2342 if Present (Items) then
2343 Prag := Pre_Post_Conditions (Items);
2344 while Present (Prag) loop
2345 if Pragma_Name (Prag) = Post_Nam then
2346 Append_Enabled_Item
2347 (Item => Build_Pragma_Check_Equivalent (Prag),
2348 List => Stmts);
2349 end if;
2351 Prag := Next_Pragma (Prag);
2352 end loop;
2353 end if;
2355 -- The subprogram body being processed is actually the proper body
2356 -- of a stub with a corresponding spec. The subprogram stub may
2357 -- carry a postcondition pragma, in which case it must be taken
2358 -- into account. The pragma appears after the stub.
2360 if Present (Spec_Id) and then Nkind (Unit_Decl) = N_Subunit then
2361 Decl := Next (Corresponding_Stub (Unit_Decl));
2362 while Present (Decl) loop
2364 -- Note that non-matching pragmas are skipped
2366 if Nkind (Decl) = N_Pragma then
2367 if Pragma_Name (Decl) = Post_Nam then
2368 Append_Enabled_Item
2369 (Item => Build_Pragma_Check_Equivalent (Decl),
2370 List => Stmts);
2371 end if;
2373 -- Skip internally generated code
2375 elsif not Comes_From_Source (Decl) then
2376 null;
2378 -- Postcondition pragmas are usually grouped together. There
2379 -- is no need to inspect the whole declarative list.
2381 else
2382 exit;
2383 end if;
2385 Next (Decl);
2386 end loop;
2387 end if;
2388 end Process_Body_Postconditions;
2390 ---------------------------------
2391 -- Process_Spec_Postconditions --
2392 ---------------------------------
2394 procedure Process_Spec_Postconditions is
2395 Subps : constant Subprogram_List :=
2396 Inherited_Subprograms (Spec_Id);
2397 Items : Node_Id;
2398 Prag : Node_Id;
2399 Subp_Id : Entity_Id;
2401 begin
2402 -- Process the contract
2404 Items := Contract (Spec_Id);
2406 if Present (Items) then
2407 Prag := Pre_Post_Conditions (Items);
2408 while Present (Prag) loop
2409 if Pragma_Name (Prag) = Name_Postcondition then
2410 Append_Enabled_Item
2411 (Item => Build_Pragma_Check_Equivalent (Prag),
2412 List => Stmts);
2413 end if;
2415 Prag := Next_Pragma (Prag);
2416 end loop;
2417 end if;
2419 -- Process the contracts of all inherited subprograms, looking for
2420 -- class-wide postconditions.
2422 for Index in Subps'Range loop
2423 Subp_Id := Subps (Index);
2424 Items := Contract (Subp_Id);
2426 if Present (Items) then
2427 Prag := Pre_Post_Conditions (Items);
2428 while Present (Prag) loop
2429 if Pragma_Name (Prag) = Name_Postcondition
2430 and then Class_Present (Prag)
2431 then
2432 Append_Enabled_Item
2433 (Item =>
2434 Build_Pragma_Check_Equivalent
2435 (Prag => Prag,
2436 Subp_Id => Spec_Id,
2437 Inher_Id => Subp_Id),
2438 List => Stmts);
2439 end if;
2441 Prag := Next_Pragma (Prag);
2442 end loop;
2443 end if;
2444 end loop;
2445 end Process_Spec_Postconditions;
2447 pragma Unmodified (Stmts);
2448 -- Stmts is passed as IN OUT to signal that the list can be updated,
2449 -- even if the corresponding integer value representing the list does
2450 -- not change.
2452 -- Start of processing for Process_Postconditions
2454 begin
2455 -- The processing of postconditions is done in reverse order (body
2456 -- first) to ensure the following arrangement:
2458 -- <refined postconditions from body>
2459 -- <postconditions from body>
2460 -- <postconditions from spec>
2461 -- <inherited postconditions>
2463 Process_Body_Postconditions (Name_Refined_Post);
2464 Process_Body_Postconditions (Name_Postcondition);
2466 if Present (Spec_Id) then
2467 Process_Spec_Postconditions;
2468 end if;
2469 end Process_Postconditions;
2471 ---------------------------
2472 -- Process_Preconditions --
2473 ---------------------------
2475 procedure Process_Preconditions is
2476 Class_Pre : Node_Id := Empty;
2477 -- The sole [inherited] class-wide precondition pragma that applies
2478 -- to the subprogram.
2480 Insert_Node : Node_Id := Empty;
2481 -- The insertion node after which all pragma Check equivalents are
2482 -- inserted.
2484 function Is_Prologue_Renaming (Decl : Node_Id) return Boolean;
2485 -- Determine whether arbitrary declaration Decl denotes a renaming of
2486 -- a discriminant or protection field _object.
2488 procedure Merge_Preconditions (From : Node_Id; Into : Node_Id);
2489 -- Merge two class-wide preconditions by "or else"-ing them. The
2490 -- changes are accumulated in parameter Into. Update the error
2491 -- message of Into.
2493 procedure Prepend_To_Decls (Item : Node_Id);
2494 -- Prepend a single item to the declarations of the subprogram body
2496 procedure Prepend_To_Decls_Or_Save (Prag : Node_Id);
2497 -- Save a class-wide precondition into Class_Pre, or prepend a normal
2498 -- precondition to the declarations of the body and analyze it.
2500 procedure Process_Inherited_Preconditions;
2501 -- Collect all inherited class-wide preconditions and merge them into
2502 -- one big precondition to be evaluated as pragma Check.
2504 procedure Process_Preconditions_For (Subp_Id : Entity_Id);
2505 -- Collect all preconditions of subprogram Subp_Id and prepend their
2506 -- pragma Check equivalents to the declarations of the body.
2508 --------------------------
2509 -- Is_Prologue_Renaming --
2510 --------------------------
2512 function Is_Prologue_Renaming (Decl : Node_Id) return Boolean is
2513 Nam : Node_Id;
2514 Obj : Entity_Id;
2515 Pref : Node_Id;
2516 Sel : Node_Id;
2518 begin
2519 if Nkind (Decl) = N_Object_Renaming_Declaration then
2520 Obj := Defining_Entity (Decl);
2521 Nam := Name (Decl);
2523 if Nkind (Nam) = N_Selected_Component then
2524 Pref := Prefix (Nam);
2525 Sel := Selector_Name (Nam);
2527 -- A discriminant renaming appears as
2528 -- Discr : constant ... := Prefix.Discr;
2530 if Ekind (Obj) = E_Constant
2531 and then Is_Entity_Name (Sel)
2532 and then Present (Entity (Sel))
2533 and then Ekind (Entity (Sel)) = E_Discriminant
2534 then
2535 return True;
2537 -- A protection field renaming appears as
2538 -- Prot : ... := _object._object;
2540 -- A renamed private component is just a component of
2541 -- _object, with an arbitrary name.
2543 elsif Ekind (Obj) = E_Variable
2544 and then Nkind (Pref) = N_Identifier
2545 and then Chars (Pref) = Name_uObject
2546 and then Nkind (Sel) = N_Identifier
2547 then
2548 return True;
2549 end if;
2550 end if;
2551 end if;
2553 return False;
2554 end Is_Prologue_Renaming;
2556 -------------------------
2557 -- Merge_Preconditions --
2558 -------------------------
2560 procedure Merge_Preconditions (From : Node_Id; Into : Node_Id) is
2561 function Expression_Arg (Prag : Node_Id) return Node_Id;
2562 -- Return the boolean expression argument of a precondition while
2563 -- updating its parentheses count for the subsequent merge.
2565 function Message_Arg (Prag : Node_Id) return Node_Id;
2566 -- Return the message argument of a precondition
2568 --------------------
2569 -- Expression_Arg --
2570 --------------------
2572 function Expression_Arg (Prag : Node_Id) return Node_Id is
2573 Args : constant List_Id := Pragma_Argument_Associations (Prag);
2574 Arg : constant Node_Id := Get_Pragma_Arg (Next (First (Args)));
2576 begin
2577 if Paren_Count (Arg) = 0 then
2578 Set_Paren_Count (Arg, 1);
2579 end if;
2581 return Arg;
2582 end Expression_Arg;
2584 -----------------
2585 -- Message_Arg --
2586 -----------------
2588 function Message_Arg (Prag : Node_Id) return Node_Id is
2589 Args : constant List_Id := Pragma_Argument_Associations (Prag);
2590 begin
2591 return Get_Pragma_Arg (Last (Args));
2592 end Message_Arg;
2594 -- Local variables
2596 From_Expr : constant Node_Id := Expression_Arg (From);
2597 From_Msg : constant Node_Id := Message_Arg (From);
2598 Into_Expr : constant Node_Id := Expression_Arg (Into);
2599 Into_Msg : constant Node_Id := Message_Arg (Into);
2600 Loc : constant Source_Ptr := Sloc (Into);
2602 -- Start of processing for Merge_Preconditions
2604 begin
2605 -- Merge the two preconditions by "or else"-ing them
2607 Rewrite (Into_Expr,
2608 Make_Or_Else (Loc,
2609 Right_Opnd => Relocate_Node (Into_Expr),
2610 Left_Opnd => From_Expr));
2612 -- Merge the two error messages to produce a single message of the
2613 -- form:
2615 -- failed precondition from ...
2616 -- also failed inherited precondition from ...
2618 if not Exception_Locations_Suppressed then
2619 Start_String (Strval (Into_Msg));
2620 Store_String_Char (ASCII.LF);
2621 Store_String_Chars (" also ");
2622 Store_String_Chars (Strval (From_Msg));
2624 Set_Strval (Into_Msg, End_String);
2625 end if;
2626 end Merge_Preconditions;
2628 ----------------------
2629 -- Prepend_To_Decls --
2630 ----------------------
2632 procedure Prepend_To_Decls (Item : Node_Id) is
2633 Decls : List_Id := Declarations (Body_Decl);
2635 begin
2636 -- Ensure that the body has a declarative list
2638 if No (Decls) then
2639 Decls := New_List;
2640 Set_Declarations (Body_Decl, Decls);
2641 end if;
2643 Prepend_To (Decls, Item);
2644 end Prepend_To_Decls;
2646 ------------------------------
2647 -- Prepend_To_Decls_Or_Save --
2648 ------------------------------
2650 procedure Prepend_To_Decls_Or_Save (Prag : Node_Id) is
2651 Check_Prag : Node_Id;
2653 begin
2654 Check_Prag := Build_Pragma_Check_Equivalent (Prag);
2656 -- Save the sole class-wide precondition (if any) for the next
2657 -- step, where it will be merged with inherited preconditions.
2659 if Class_Present (Prag) then
2660 pragma Assert (No (Class_Pre));
2661 Class_Pre := Check_Prag;
2663 -- Accumulate the corresponding Check pragmas at the top of the
2664 -- declarations. Prepending the items ensures that they will be
2665 -- evaluated in their original order.
2667 else
2668 if Present (Insert_Node) then
2669 Insert_After (Insert_Node, Check_Prag);
2670 else
2671 Prepend_To_Decls (Check_Prag);
2672 end if;
2674 Analyze (Check_Prag);
2675 end if;
2676 end Prepend_To_Decls_Or_Save;
2678 -------------------------------------
2679 -- Process_Inherited_Preconditions --
2680 -------------------------------------
2682 procedure Process_Inherited_Preconditions is
2683 Subps : constant Subprogram_List :=
2684 Inherited_Subprograms (Spec_Id);
2685 Check_Prag : Node_Id;
2686 Items : Node_Id;
2687 Prag : Node_Id;
2688 Subp_Id : Entity_Id;
2690 begin
2691 -- Process the contracts of all inherited subprograms, looking for
2692 -- class-wide preconditions.
2694 for Index in Subps'Range loop
2695 Subp_Id := Subps (Index);
2696 Items := Contract (Subp_Id);
2698 if Present (Items) then
2699 Prag := Pre_Post_Conditions (Items);
2700 while Present (Prag) loop
2701 if Pragma_Name (Prag) = Name_Precondition
2702 and then Class_Present (Prag)
2703 then
2704 Check_Prag :=
2705 Build_Pragma_Check_Equivalent
2706 (Prag => Prag,
2707 Subp_Id => Spec_Id,
2708 Inher_Id => Subp_Id);
2710 -- The spec of an inherited subprogram already yielded
2711 -- a class-wide precondition. Merge the existing
2712 -- precondition with the current one using "or else".
2714 if Present (Class_Pre) then
2715 Merge_Preconditions (Check_Prag, Class_Pre);
2716 else
2717 Class_Pre := Check_Prag;
2718 end if;
2719 end if;
2721 Prag := Next_Pragma (Prag);
2722 end loop;
2723 end if;
2724 end loop;
2726 -- Add the merged class-wide preconditions
2728 if Present (Class_Pre) then
2729 Prepend_To_Decls (Class_Pre);
2730 Analyze (Class_Pre);
2731 end if;
2732 end Process_Inherited_Preconditions;
2734 -------------------------------
2735 -- Process_Preconditions_For --
2736 -------------------------------
2738 procedure Process_Preconditions_For (Subp_Id : Entity_Id) is
2739 Items : constant Node_Id := Contract (Subp_Id);
2740 Decl : Node_Id;
2741 Prag : Node_Id;
2742 Subp_Decl : Node_Id;
2744 begin
2745 -- Process the contract
2747 if Present (Items) then
2748 Prag := Pre_Post_Conditions (Items);
2749 while Present (Prag) loop
2750 if Pragma_Name (Prag) = Name_Precondition then
2751 Prepend_To_Decls_Or_Save (Prag);
2752 end if;
2754 Prag := Next_Pragma (Prag);
2755 end loop;
2756 end if;
2758 -- The subprogram declaration being processed is actually a body
2759 -- stub. The stub may carry a precondition pragma, in which case
2760 -- it must be taken into account. The pragma appears after the
2761 -- stub.
2763 Subp_Decl := Unit_Declaration_Node (Subp_Id);
2765 if Nkind (Subp_Decl) = N_Subprogram_Body_Stub then
2767 -- Inspect the declarations following the body stub
2769 Decl := Next (Subp_Decl);
2770 while Present (Decl) loop
2772 -- Note that non-matching pragmas are skipped
2774 if Nkind (Decl) = N_Pragma then
2775 if Pragma_Name (Decl) = Name_Precondition then
2776 Prepend_To_Decls_Or_Save (Decl);
2777 end if;
2779 -- Skip internally generated code
2781 elsif not Comes_From_Source (Decl) then
2782 null;
2784 -- Preconditions are usually grouped together. There is no
2785 -- need to inspect the whole declarative list.
2787 else
2788 exit;
2789 end if;
2791 Next (Decl);
2792 end loop;
2793 end if;
2794 end Process_Preconditions_For;
2796 -- Local variables
2798 Decls : constant List_Id := Declarations (Body_Decl);
2799 Decl : Node_Id;
2801 -- Start of processing for Process_Preconditions
2803 begin
2804 -- Find the proper insertion point for all pragma Check equivalents
2806 if Present (Decls) then
2807 Decl := First (Decls);
2808 while Present (Decl) loop
2810 -- First source declaration terminates the search, because all
2811 -- preconditions must be evaluated prior to it, by definition.
2813 if Comes_From_Source (Decl) then
2814 exit;
2816 -- Certain internally generated object renamings such as those
2817 -- for discriminants and protection fields must be elaborated
2818 -- before the preconditions are evaluated, as their expressions
2819 -- may mention the discriminants. The renamings include those
2820 -- for private components so we need to find the last such.
2822 elsif Is_Prologue_Renaming (Decl) then
2823 while Present (Next (Decl))
2824 and then Is_Prologue_Renaming (Next (Decl))
2825 loop
2826 Next (Decl);
2827 end loop;
2829 Insert_Node := Decl;
2831 -- Otherwise the declaration does not come from source. This
2832 -- also terminates the search, because internal code may raise
2833 -- exceptions which should not preempt the preconditions.
2835 else
2836 exit;
2837 end if;
2839 Next (Decl);
2840 end loop;
2841 end if;
2843 -- The processing of preconditions is done in reverse order (body
2844 -- first), because each pragma Check equivalent is inserted at the
2845 -- top of the declarations. This ensures that the final order is
2846 -- consistent with following diagram:
2848 -- <inherited preconditions>
2849 -- <preconditions from spec>
2850 -- <preconditions from body>
2852 Process_Preconditions_For (Body_Id);
2854 if Present (Spec_Id) then
2855 Process_Preconditions_For (Spec_Id);
2856 Process_Inherited_Preconditions;
2857 end if;
2858 end Process_Preconditions;
2860 -- Local variables
2862 Restore_Scope : Boolean := False;
2863 Result : Entity_Id;
2864 Stmts : List_Id := No_List;
2865 Subp_Id : Entity_Id;
2867 -- Start of processing for Expand_Subprogram_Contract
2869 begin
2870 -- Obtain the entity of the initial declaration
2872 if Present (Spec_Id) then
2873 Subp_Id := Spec_Id;
2874 else
2875 Subp_Id := Body_Id;
2876 end if;
2878 -- Do not perform expansion activity when it is not needed
2880 if not Expander_Active then
2881 return;
2883 -- ASIS requires an unaltered tree
2885 elsif ASIS_Mode then
2886 return;
2888 -- GNATprove does not need the executable semantics of a contract
2890 elsif GNATprove_Mode then
2891 return;
2893 -- The contract of a generic subprogram or one declared in a generic
2894 -- context is not expanded, as the corresponding instance will provide
2895 -- the executable semantics of the contract.
2897 elsif Is_Generic_Subprogram (Subp_Id) or else Inside_A_Generic then
2898 return;
2900 -- All subprograms carry a contract, but for some it is not significant
2901 -- and should not be processed. This is a small optimization.
2903 elsif not Has_Significant_Contract (Subp_Id) then
2904 return;
2906 -- The contract of an ignored Ghost subprogram does not need expansion,
2907 -- because the subprogram and all calls to it will be removed.
2909 elsif Is_Ignored_Ghost_Entity (Subp_Id) then
2910 return;
2911 end if;
2913 -- Do not re-expand the same contract. This scenario occurs when a
2914 -- construct is rewritten into something else during its analysis
2915 -- (expression functions for instance).
2917 if Has_Expanded_Contract (Subp_Id) then
2918 return;
2920 -- Otherwise mark the subprogram
2922 else
2923 Set_Has_Expanded_Contract (Subp_Id);
2924 end if;
2926 -- Ensure that the formal parameters are visible when expanding all
2927 -- contract items.
2929 if not In_Open_Scopes (Subp_Id) then
2930 Restore_Scope := True;
2931 Push_Scope (Subp_Id);
2933 if Is_Generic_Subprogram (Subp_Id) then
2934 Install_Generic_Formals (Subp_Id);
2935 else
2936 Install_Formals (Subp_Id);
2937 end if;
2938 end if;
2940 -- The expansion of a subprogram contract involves the creation of Check
2941 -- pragmas to verify the contract assertions of the spec and body in a
2942 -- particular order. The order is as follows:
2944 -- function Example (...) return ... is
2945 -- procedure _Postconditions (...) is
2946 -- begin
2947 -- <refined postconditions from body>
2948 -- <postconditions from body>
2949 -- <postconditions from spec>
2950 -- <inherited postconditions>
2951 -- <contract case consequences>
2952 -- <invariant check of function result>
2953 -- <invariant and predicate checks of parameters>
2954 -- end _Postconditions;
2956 -- <inherited preconditions>
2957 -- <preconditions from spec>
2958 -- <preconditions from body>
2959 -- <contract case conditions>
2961 -- <source declarations>
2962 -- begin
2963 -- <source statements>
2965 -- _Preconditions (Result);
2966 -- return Result;
2967 -- end Example;
2969 -- Routine _Postconditions holds all contract assertions that must be
2970 -- verified on exit from the related subprogram.
2972 -- Step 1: Handle all preconditions. This action must come before the
2973 -- processing of pragma Contract_Cases because the pragma prepends items
2974 -- to the body declarations.
2976 Process_Preconditions;
2978 -- Step 2: Handle all postconditions. This action must come before the
2979 -- processing of pragma Contract_Cases because the pragma appends items
2980 -- to list Stmts.
2982 Process_Postconditions (Stmts);
2984 -- Step 3: Handle pragma Contract_Cases. This action must come before
2985 -- the processing of invariants and predicates because those append
2986 -- items to list Stmts.
2988 Process_Contract_Cases (Stmts);
2990 -- Step 4: Apply invariant and predicate checks on a function result and
2991 -- all formals. The resulting checks are accumulated in list Stmts.
2993 Add_Invariant_And_Predicate_Checks (Subp_Id, Stmts, Result);
2995 -- Step 5: Construct procedure _Postconditions
2997 Build_Postconditions_Procedure (Subp_Id, Stmts, Result);
2999 if Restore_Scope then
3000 End_Scope;
3001 end if;
3002 end Expand_Subprogram_Contract;
3004 -------------------------------
3005 -- Freeze_Previous_Contracts --
3006 -------------------------------
3008 procedure Freeze_Previous_Contracts (Body_Decl : Node_Id) is
3009 function Causes_Contract_Freezing (N : Node_Id) return Boolean;
3010 pragma Inline (Causes_Contract_Freezing);
3011 -- Determine whether arbitrary node N causes contract freezing
3013 procedure Freeze_Contracts;
3014 pragma Inline (Freeze_Contracts);
3015 -- Freeze the contracts of all eligible constructs which precede body
3016 -- Body_Decl.
3018 procedure Freeze_Enclosing_Package_Body;
3019 pragma Inline (Freeze_Enclosing_Package_Body);
3020 -- Freeze the contract of the nearest package body (if any) which
3021 -- encloses body Body_Decl.
3023 ------------------------------
3024 -- Causes_Contract_Freezing --
3025 ------------------------------
3027 function Causes_Contract_Freezing (N : Node_Id) return Boolean is
3028 begin
3029 return Nkind_In (N, N_Entry_Body,
3030 N_Package_Body,
3031 N_Protected_Body,
3032 N_Subprogram_Body,
3033 N_Subprogram_Body_Stub,
3034 N_Task_Body);
3035 end Causes_Contract_Freezing;
3037 ----------------------
3038 -- Freeze_Contracts --
3039 ----------------------
3041 procedure Freeze_Contracts is
3042 Body_Id : constant Entity_Id := Defining_Entity (Body_Decl);
3043 Decl : Node_Id;
3045 begin
3046 -- Nothing to do when the body which causes freezing does not appear
3047 -- in a declarative list because there cannot possibly be constructs
3048 -- with contracts.
3050 if not Is_List_Member (Body_Decl) then
3051 return;
3052 end if;
3054 -- Inspect the declarations preceding the body, and freeze individual
3055 -- contracts of eligible constructs.
3057 Decl := Prev (Body_Decl);
3058 while Present (Decl) loop
3060 -- Stop the traversal when a preceding construct that causes
3061 -- freezing is encountered as there is no point in refreezing
3062 -- the already frozen constructs.
3064 if Causes_Contract_Freezing (Decl) then
3065 exit;
3067 -- Entry or subprogram declarations
3069 elsif Nkind_In (Decl, N_Abstract_Subprogram_Declaration,
3070 N_Entry_Declaration,
3071 N_Generic_Subprogram_Declaration,
3072 N_Subprogram_Declaration)
3073 then
3074 Analyze_Entry_Or_Subprogram_Contract
3075 (Subp_Id => Defining_Entity (Decl),
3076 Freeze_Id => Body_Id);
3078 -- Objects
3080 elsif Nkind (Decl) = N_Object_Declaration then
3081 Analyze_Object_Contract
3082 (Obj_Id => Defining_Entity (Decl),
3083 Freeze_Id => Body_Id);
3085 -- Protected units
3087 elsif Nkind_In (Decl, N_Protected_Type_Declaration,
3088 N_Single_Protected_Declaration)
3089 then
3090 Analyze_Protected_Contract (Defining_Entity (Decl));
3092 -- Subprogram body stubs
3094 elsif Nkind (Decl) = N_Subprogram_Body_Stub then
3095 Analyze_Subprogram_Body_Stub_Contract (Defining_Entity (Decl));
3097 -- Task units
3099 elsif Nkind_In (Decl, N_Single_Task_Declaration,
3100 N_Task_Type_Declaration)
3101 then
3102 Analyze_Task_Contract (Defining_Entity (Decl));
3103 end if;
3105 Prev (Decl);
3106 end loop;
3107 end Freeze_Contracts;
3109 -----------------------------------
3110 -- Freeze_Enclosing_Package_Body --
3111 -----------------------------------
3113 procedure Freeze_Enclosing_Package_Body is
3114 Orig_Decl : constant Node_Id := Original_Node (Body_Decl);
3115 Par : Node_Id;
3117 begin
3118 -- Climb the parent chain looking for an enclosing package body. Do
3119 -- not use the scope stack, because a body utilizes the entity of its
3120 -- corresponding spec.
3122 Par := Parent (Body_Decl);
3123 while Present (Par) loop
3124 if Nkind (Par) = N_Package_Body then
3125 Analyze_Package_Body_Contract
3126 (Body_Id => Defining_Entity (Par),
3127 Freeze_Id => Defining_Entity (Body_Decl));
3129 exit;
3131 -- Do not look for an enclosing package body when the construct
3132 -- which causes freezing is a body generated for an expression
3133 -- function and it appears within a package spec. This ensures
3134 -- that the traversal will not reach too far up the parent chain
3135 -- and attempt to freeze a package body which must not be frozen.
3137 -- package body Enclosing_Body
3138 -- with Refined_State => (State => Var)
3139 -- is
3140 -- package Nested is
3141 -- type Some_Type is ...;
3142 -- function Cause_Freezing return ...;
3143 -- private
3144 -- function Cause_Freezing is (...);
3145 -- end Nested;
3147 -- Var : Nested.Some_Type;
3149 elsif Nkind (Par) = N_Package_Declaration
3150 and then Nkind (Orig_Decl) = N_Expression_Function
3151 then
3152 exit;
3154 -- Prevent the search from going too far
3156 elsif Is_Body_Or_Package_Declaration (Par) then
3157 exit;
3158 end if;
3160 Par := Parent (Par);
3161 end loop;
3162 end Freeze_Enclosing_Package_Body;
3164 -- Local variables
3166 Body_Id : constant Entity_Id := Defining_Entity (Body_Decl);
3168 -- Start of processing for Freeze_Previous_Contracts
3170 begin
3171 pragma Assert (Causes_Contract_Freezing (Body_Decl));
3173 -- A body that is in the process of being inlined appears from source,
3174 -- but carries name _parent. Such a body does not cause freezing of
3175 -- contracts.
3177 if Chars (Body_Id) = Name_uParent then
3178 return;
3179 end if;
3181 Freeze_Enclosing_Package_Body;
3182 Freeze_Contracts;
3183 end Freeze_Previous_Contracts;
3185 ---------------------------------
3186 -- Inherit_Subprogram_Contract --
3187 ---------------------------------
3189 procedure Inherit_Subprogram_Contract
3190 (Subp : Entity_Id;
3191 From_Subp : Entity_Id)
3193 procedure Inherit_Pragma (Prag_Id : Pragma_Id);
3194 -- Propagate a pragma denoted by Prag_Id from From_Subp's contract to
3195 -- Subp's contract.
3197 --------------------
3198 -- Inherit_Pragma --
3199 --------------------
3201 procedure Inherit_Pragma (Prag_Id : Pragma_Id) is
3202 Prag : constant Node_Id := Get_Pragma (From_Subp, Prag_Id);
3203 New_Prag : Node_Id;
3205 begin
3206 -- A pragma cannot be part of more than one First_Pragma/Next_Pragma
3207 -- chains, therefore the node must be replicated. The new pragma is
3208 -- flagged as inherited for distinction purposes.
3210 if Present (Prag) then
3211 New_Prag := New_Copy_Tree (Prag);
3212 Set_Is_Inherited_Pragma (New_Prag);
3214 Add_Contract_Item (New_Prag, Subp);
3215 end if;
3216 end Inherit_Pragma;
3218 -- Start of processing for Inherit_Subprogram_Contract
3220 begin
3221 -- Inheritance is carried out only when both entities are subprograms
3222 -- with contracts.
3224 if Is_Subprogram_Or_Generic_Subprogram (Subp)
3225 and then Is_Subprogram_Or_Generic_Subprogram (From_Subp)
3226 and then Present (Contract (From_Subp))
3227 then
3228 Inherit_Pragma (Pragma_Extensions_Visible);
3229 end if;
3230 end Inherit_Subprogram_Contract;
3232 -------------------------------------
3233 -- Instantiate_Subprogram_Contract --
3234 -------------------------------------
3236 procedure Instantiate_Subprogram_Contract (Templ : Node_Id; L : List_Id) is
3237 procedure Instantiate_Pragmas (First_Prag : Node_Id);
3238 -- Instantiate all contract-related source pragmas found in the list,
3239 -- starting with pragma First_Prag. Each instantiated pragma is added
3240 -- to list L.
3242 -------------------------
3243 -- Instantiate_Pragmas --
3244 -------------------------
3246 procedure Instantiate_Pragmas (First_Prag : Node_Id) is
3247 Inst_Prag : Node_Id;
3248 Prag : Node_Id;
3250 begin
3251 Prag := First_Prag;
3252 while Present (Prag) loop
3253 if Is_Generic_Contract_Pragma (Prag) then
3254 Inst_Prag :=
3255 Copy_Generic_Node (Prag, Empty, Instantiating => True);
3257 Set_Analyzed (Inst_Prag, False);
3258 Append_To (L, Inst_Prag);
3259 end if;
3261 Prag := Next_Pragma (Prag);
3262 end loop;
3263 end Instantiate_Pragmas;
3265 -- Local variables
3267 Items : constant Node_Id := Contract (Defining_Entity (Templ));
3269 -- Start of processing for Instantiate_Subprogram_Contract
3271 begin
3272 if Present (Items) then
3273 Instantiate_Pragmas (Pre_Post_Conditions (Items));
3274 Instantiate_Pragmas (Contract_Test_Cases (Items));
3275 Instantiate_Pragmas (Classifications (Items));
3276 end if;
3277 end Instantiate_Subprogram_Contract;
3279 ----------------------------------------
3280 -- Save_Global_References_In_Contract --
3281 ----------------------------------------
3283 procedure Save_Global_References_In_Contract
3284 (Templ : Node_Id;
3285 Gen_Id : Entity_Id)
3287 procedure Save_Global_References_In_List (First_Prag : Node_Id);
3288 -- Save all global references in contract-related source pragmas found
3289 -- in the list, starting with pragma First_Prag.
3291 ------------------------------------
3292 -- Save_Global_References_In_List --
3293 ------------------------------------
3295 procedure Save_Global_References_In_List (First_Prag : Node_Id) is
3296 Prag : Node_Id;
3298 begin
3299 Prag := First_Prag;
3300 while Present (Prag) loop
3301 if Is_Generic_Contract_Pragma (Prag) then
3302 Save_Global_References (Prag);
3303 end if;
3305 Prag := Next_Pragma (Prag);
3306 end loop;
3307 end Save_Global_References_In_List;
3309 -- Local variables
3311 Items : constant Node_Id := Contract (Defining_Entity (Templ));
3313 -- Start of processing for Save_Global_References_In_Contract
3315 begin
3316 -- The entity of the analyzed generic copy must be on the scope stack
3317 -- to ensure proper detection of global references.
3319 Push_Scope (Gen_Id);
3321 if Permits_Aspect_Specifications (Templ)
3322 and then Has_Aspects (Templ)
3323 then
3324 Save_Global_References_In_Aspects (Templ);
3325 end if;
3327 if Present (Items) then
3328 Save_Global_References_In_List (Pre_Post_Conditions (Items));
3329 Save_Global_References_In_List (Contract_Test_Cases (Items));
3330 Save_Global_References_In_List (Classifications (Items));
3331 end if;
3333 Pop_Scope;
3334 end Save_Global_References_In_Contract;
3336 end Contracts;