1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Casing; use Casing;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Errout; use Errout;
31 with Exp_Ch11; use Exp_Ch11;
32 with Exp_Util; use Exp_Util;
33 with Expander; use Expander;
34 with Namet; use Namet;
35 with Nlists; use Nlists;
36 with Nmake; use Nmake;
38 with Restrict; use Restrict;
39 with Rident; use Rident;
40 with Rtsfind; use Rtsfind;
42 with Sem_Res; use Sem_Res;
43 with Sem_Util; use Sem_Util;
44 with Sinfo; use Sinfo;
45 with Sinput; use Sinput;
46 with Snames; use Snames;
47 with Stringt; use Stringt;
48 with Stand; use Stand;
49 with Targparm; use Targparm;
50 with Tbuild; use Tbuild;
51 with Uintp; use Uintp;
53 package body Exp_Prag is
55 -----------------------
56 -- Local Subprograms --
57 -----------------------
59 function Arg1 (N : Node_Id) return Node_Id;
60 function Arg2 (N : Node_Id) return Node_Id;
61 function Arg3 (N : Node_Id) return Node_Id;
62 -- Obtain specified pragma argument expression
64 procedure Expand_Pragma_Abort_Defer (N : Node_Id);
65 procedure Expand_Pragma_Check (N : Node_Id);
66 procedure Expand_Pragma_Common_Object (N : Node_Id);
67 procedure Expand_Pragma_Import_Or_Interface (N : Node_Id);
68 procedure Expand_Pragma_Import_Export_Exception (N : Node_Id);
69 procedure Expand_Pragma_Inspection_Point (N : Node_Id);
70 procedure Expand_Pragma_Interrupt_Priority (N : Node_Id);
71 procedure Expand_Pragma_Psect_Object (N : Node_Id);
72 procedure Expand_Pragma_Relative_Deadline (N : Node_Id);
78 function Arg1 (N : Node_Id) return Node_Id is
79 Arg : constant Node_Id := First (Pragma_Argument_Associations (N));
82 and then Nkind (Arg) = N_Pragma_Argument_Association
84 return Expression (Arg);
94 function Arg2 (N : Node_Id) return Node_Id is
95 Arg1 : constant Node_Id := First (Pragma_Argument_Associations (N));
103 Arg : constant Node_Id := Next (Arg1);
106 and then Nkind (Arg) = N_Pragma_Argument_Association
108 return Expression (Arg);
120 function Arg3 (N : Node_Id) return Node_Id is
121 Arg1 : constant Node_Id := First (Pragma_Argument_Associations (N));
129 Arg : Node_Id := Next (Arg1);
138 and then Nkind (Arg) = N_Pragma_Argument_Association
140 return Expression (Arg);
149 ---------------------
150 -- Expand_N_Pragma --
151 ---------------------
153 procedure Expand_N_Pragma (N : Node_Id) is
154 Pname : constant Name_Id := Pragma_Name (N);
157 -- Note: we may have a pragma whose Pragma_Identifier field is not a
158 -- recognized pragma, and we must ignore it at this stage.
160 if Is_Pragma_Name (Pname) then
161 case Get_Pragma_Id (Pname) is
163 -- Pragmas requiring special expander action
165 when Pragma_Abort_Defer =>
166 Expand_Pragma_Abort_Defer (N);
169 Expand_Pragma_Check (N);
171 when Pragma_Common_Object =>
172 Expand_Pragma_Common_Object (N);
174 when Pragma_Export_Exception =>
175 Expand_Pragma_Import_Export_Exception (N);
177 when Pragma_Import =>
178 Expand_Pragma_Import_Or_Interface (N);
180 when Pragma_Import_Exception =>
181 Expand_Pragma_Import_Export_Exception (N);
183 when Pragma_Inspection_Point =>
184 Expand_Pragma_Inspection_Point (N);
186 when Pragma_Interface =>
187 Expand_Pragma_Import_Or_Interface (N);
189 when Pragma_Interrupt_Priority =>
190 Expand_Pragma_Interrupt_Priority (N);
192 when Pragma_Psect_Object =>
193 Expand_Pragma_Psect_Object (N);
195 when Pragma_Relative_Deadline =>
196 Expand_Pragma_Relative_Deadline (N);
198 -- All other pragmas need no expander action
206 -------------------------------
207 -- Expand_Pragma_Abort_Defer --
208 -------------------------------
210 -- An Abort_Defer pragma appears as the first statement in a handled
211 -- statement sequence (right after the begin). It defers aborts for
212 -- the entire statement sequence, but not for any declarations or
213 -- handlers (if any) associated with this statement sequence.
215 -- The transformation is to transform
217 -- pragma Abort_Defer;
226 -- when all others =>
227 -- Abort_Undefer.all;
230 -- Abort_Undefer_Direct;
233 procedure Expand_Pragma_Abort_Defer (N : Node_Id) is
234 Loc : constant Source_Ptr := Sloc (N);
238 Blk : constant Entity_Id :=
239 New_Internal_Entity (E_Block, Current_Scope, Sloc (N), 'B');
242 Stms := New_List (Build_Runtime_Call (Loc, RE_Abort_Defer));
245 Stm := Remove_Next (N);
251 Make_Handled_Sequence_Of_Statements (Loc,
254 New_Occurrence_Of (RTE (RE_Abort_Undefer_Direct), Loc));
257 Make_Block_Statement (Loc,
258 Handled_Statement_Sequence => HSS));
260 Set_Scope (Blk, Current_Scope);
261 Set_Etype (Blk, Standard_Void_Type);
262 Set_Identifier (N, New_Occurrence_Of (Blk, Sloc (N)));
263 Expand_At_End_Handler (HSS, Blk);
265 end Expand_Pragma_Abort_Defer;
267 --------------------------
268 -- Expand_Pragma_Check --
269 --------------------------
271 procedure Expand_Pragma_Check (N : Node_Id) is
272 Cond : constant Node_Id := Arg2 (N);
273 Loc : constant Source_Ptr := Sloc (Cond);
274 Nam : constant Name_Id := Chars (Arg1 (N));
278 -- We already know that this check is enabled, because otherwise the
279 -- semantic pass dealt with rewriting the assertion (see Sem_Prag)
281 -- Since this check is enabled, we rewrite the pragma into a
282 -- corresponding if statement, and then analyze the statement
284 -- The normal case expansion transforms:
286 -- pragma Check (name, condition [,message]);
290 -- if not condition then
291 -- System.Assertions.Raise_Assert_Failure (Str);
294 -- where Str is the message if one is present, or the default of
295 -- name failed at file:line if no message is given (the "name failed
296 -- at" is omitted for name = Assertion, since it is redundant, given
297 -- that the name of the exception is Assert_Failure.)
299 -- An alternative expansion is used when the No_Exception_Propagation
300 -- restriction is active and there is a local Assert_Failure handler.
301 -- This is not a common combination of circumstances, but it occurs in
302 -- the context of Aunit and the zero footprint profile. In this case we
305 -- if not condition then
306 -- raise Assert_Failure;
309 -- This will then be transformed into a goto, and the local handler will
310 -- be able to handle the assert error (which would not be the case if a
311 -- call is made to the Raise_Assert_Failure procedure).
313 -- We also generate the direct raise if the Suppress_Exception_Locations
314 -- is active, since we don't want to generate messages in this case.
316 -- Note that the reason we do not always generate a direct raise is that
317 -- the form in which the procedure is called allows for more efficient
318 -- breakpointing of assertion errors.
320 -- Generate the appropriate if statement. Note that we consider this to
321 -- be an explicit conditional in the source, not an implicit if, so we
322 -- do not call Make_Implicit_If_Statement.
324 -- Case where we generate a direct raise
326 if ((Debug_Flag_Dot_G
327 or else Restriction_Active (No_Exception_Propagation))
328 and then Present (Find_Local_Handler (RTE (RE_Assert_Failure), N)))
329 or else (Opt.Exception_Locations_Suppressed and then No (Arg3 (N)))
332 Make_If_Statement (Loc,
336 Then_Statements => New_List (
337 Make_Raise_Statement (Loc,
339 New_Reference_To (RTE (RE_Assert_Failure), Loc)))));
341 -- Case where we call the procedure
344 -- If we have a message given, use it
346 if Present (Arg3 (N)) then
347 Msg := Get_Pragma_Arg (Arg3 (N));
349 -- Here we have no string, so prepare one
353 Msg_Loc : constant String := Build_Location_String (Loc);
358 -- For Assert, we just use the location
360 if Nam = Name_Assertion then
363 -- For predicate, we generate the string "predicate failed
364 -- at yyy". We prefer all lower case for predicate.
366 elsif Nam = Name_Predicate then
367 Add_Str_To_Name_Buffer ("predicate failed at ");
369 -- For special case of Precondition/Postcondition the string is
370 -- "failed xx from yy" where xx is precondition/postcondition
371 -- in all lower case. The reason for this different wording is
372 -- that the failure is not at the point of occurrence of the
373 -- pragma, unlike the other Check cases.
375 elsif Nam = Name_Precondition
377 Nam = Name_Postcondition
379 Get_Name_String (Nam);
380 Insert_Str_In_Name_Buffer ("failed ", 1);
381 Add_Str_To_Name_Buffer (" from ");
383 -- For all other checks, the string is "xxx failed at yyy"
384 -- where xxx is the check name with current source file casing.
387 Get_Name_String (Nam);
388 Set_Casing (Identifier_Casing (Current_Source_File));
389 Add_Str_To_Name_Buffer (" failed at ");
392 -- In all cases, add location string
394 Add_Str_To_Name_Buffer (Msg_Loc);
398 Msg := Make_String_Literal (Loc, Name_Buffer (1 .. Name_Len));
402 -- Now rewrite as an if statement
405 Make_If_Statement (Loc,
409 Then_Statements => New_List (
410 Make_Procedure_Call_Statement (Loc,
412 New_Reference_To (RTE (RE_Raise_Assert_Failure), Loc),
413 Parameter_Associations => New_List (Relocate_Node (Msg))))));
418 -- If new condition is always false, give a warning
420 if Warn_On_Assertion_Failure
421 and then Nkind (N) = N_Procedure_Call_Statement
422 and then Is_RTE (Entity (Name (N)), RE_Raise_Assert_Failure)
424 -- If original condition was a Standard.False, we assume that this is
425 -- indeed intended to raise assert error and no warning is required.
427 if Is_Entity_Name (Original_Node (Cond))
428 and then Entity (Original_Node (Cond)) = Standard_False
431 elsif Nam = Name_Assertion then
432 Error_Msg_N ("?assertion will fail at run time", N);
434 Error_Msg_N ("?check will fail at run time", N);
437 end Expand_Pragma_Check;
439 ---------------------------------
440 -- Expand_Pragma_Common_Object --
441 ---------------------------------
443 -- Use a machine attribute to replicate semantic effect in DEC Ada
445 -- pragma Machine_Attribute (intern_name, "common_object", extern_name);
447 -- For now we do nothing with the size attribute ???
449 -- Note: Psect_Object shares this processing
451 procedure Expand_Pragma_Common_Object (N : Node_Id) is
452 Loc : constant Source_Ptr := Sloc (N);
454 Internal : constant Node_Id := Arg1 (N);
455 External : constant Node_Id := Arg2 (N);
458 -- Psect value upper cased as string literal
460 Iloc : constant Source_Ptr := Sloc (Internal);
461 Eloc : constant Source_Ptr := Sloc (External);
465 -- Acquire Psect value and fold to upper case
467 if Present (External) then
468 if Nkind (External) = N_String_Literal then
469 String_To_Name_Buffer (Strval (External));
471 Get_Name_String (Chars (External));
477 Make_String_Literal (Eloc,
478 Strval => String_From_Name_Buffer);
481 Get_Name_String (Chars (Internal));
484 Make_String_Literal (Iloc,
485 Strval => String_From_Name_Buffer);
488 Ploc := Sloc (Psect);
492 Insert_After_And_Analyze (N,
494 Chars => Name_Machine_Attribute,
495 Pragma_Argument_Associations => New_List (
496 Make_Pragma_Argument_Association (Iloc,
497 Expression => New_Copy_Tree (Internal)),
498 Make_Pragma_Argument_Association (Eloc,
500 Make_String_Literal (Sloc => Ploc,
501 Strval => "common_object")),
502 Make_Pragma_Argument_Association (Ploc,
503 Expression => New_Copy_Tree (Psect)))));
505 end Expand_Pragma_Common_Object;
507 ---------------------------------------
508 -- Expand_Pragma_Import_Or_Interface --
509 ---------------------------------------
511 -- When applied to a variable, the default initialization must not be
512 -- done. As it is already done when the pragma is found, we just get rid
513 -- of the call the initialization procedure which followed the object
514 -- declaration. The call is inserted after the declaration, but validity
515 -- checks may also have been inserted and the initialization call does
516 -- not necessarily appear immediately after the object declaration.
518 -- We can't use the freezing mechanism for this purpose, since we
519 -- have to elaborate the initialization expression when it is first
520 -- seen (i.e. this elaboration cannot be deferred to the freeze point).
522 procedure Expand_Pragma_Import_Or_Interface (N : Node_Id) is
523 Def_Id : constant Entity_Id := Entity (Arg2 (N));
527 if Ekind (Def_Id) = E_Variable then
529 -- Find generated initialization call for object, if any
531 Init_Call := Find_Init_Call (Def_Id, Rep_Clause => N);
532 if Present (Init_Call) then
536 -- Any default initialization expression should be removed
537 -- (e.g., null defaults for access objects, zero initialization
538 -- of packed bit arrays). Imported objects aren't allowed to
539 -- have explicit initialization, so the expression must have
540 -- been generated by the compiler.
542 if No (Init_Call) and then Present (Expression (Parent (Def_Id))) then
543 Set_Expression (Parent (Def_Id), Empty);
546 end Expand_Pragma_Import_Or_Interface;
548 -------------------------------------------
549 -- Expand_Pragma_Import_Export_Exception --
550 -------------------------------------------
552 -- For a VMS exception fix up the language field with "VMS"
553 -- instead of "Ada" (gigi needs this), create a constant that will be the
554 -- value of the VMS condition code and stuff the Interface_Name field
555 -- with the unexpanded name of the exception (if not already set).
556 -- For a Ada exception, just stuff the Interface_Name field
557 -- with the unexpanded name of the exception (if not already set).
559 procedure Expand_Pragma_Import_Export_Exception (N : Node_Id) is
561 -- This pragma is only effective on OpenVMS systems, it was ignored
562 -- on non-VMS systems, and we need to ignore it here as well.
564 if not OpenVMS_On_Target then
569 Id : constant Entity_Id := Entity (Arg1 (N));
570 Call : constant Node_Id := Register_Exception_Call (Id);
571 Loc : constant Source_Ptr := Sloc (N);
574 if Present (Call) then
576 Excep_Internal : constant Node_Id := Make_Temporary (Loc, 'V');
577 Export_Pragma : Node_Id;
578 Excep_Alias : Node_Id;
579 Excep_Object : Node_Id;
580 Excep_Image : String_Id;
586 if Present (Interface_Name (Id)) then
587 Excep_Image := Strval (Interface_Name (Id));
589 Get_Name_String (Chars (Id));
591 Excep_Image := String_From_Name_Buffer;
594 Exdata := Component_Associations (Expression (Parent (Id)));
596 if Is_VMS_Exception (Id) then
597 Lang_Char := Next (First (Exdata));
599 -- Change the one-character language designator to 'V'
601 Rewrite (Expression (Lang_Char),
602 Make_Character_Literal (Loc,
604 Char_Literal_Value =>
605 UI_From_Int (Character'Pos ('V'))));
606 Analyze (Expression (Lang_Char));
608 if Exception_Code (Id) /= No_Uint then
610 Make_Integer_Literal (Loc,
611 Intval => Exception_Code (Id));
614 Make_Object_Declaration (Loc,
615 Defining_Identifier => Excep_Internal,
617 New_Reference_To (RTE (RE_Exception_Code), Loc));
619 Insert_Action (N, Excep_Object);
620 Analyze (Excep_Object);
624 (UI_To_Int (Exception_Code (Id)) / 8 * 8);
631 (Make_Pragma_Argument_Association
634 New_Reference_To (Excep_Internal, Loc)),
636 Make_Pragma_Argument_Association
641 Strval => End_String))));
643 Insert_Action (N, Excep_Alias);
644 Analyze (Excep_Alias);
651 (Make_Pragma_Argument_Association (Loc,
652 Expression => Make_Identifier (Loc, Name_C)),
654 Make_Pragma_Argument_Association (Loc,
656 New_Reference_To (Excep_Internal, Loc)),
658 Make_Pragma_Argument_Association (Loc,
660 Make_String_Literal (Loc, Excep_Image)),
662 Make_Pragma_Argument_Association (Loc,
664 Make_String_Literal (Loc, Excep_Image))));
666 Insert_Action (N, Export_Pragma);
667 Analyze (Export_Pragma);
671 Unchecked_Convert_To (RTE (RE_Exception_Code),
672 Make_Function_Call (Loc,
674 New_Reference_To (RTE (RE_Import_Value), Loc),
675 Parameter_Associations => New_List
676 (Make_String_Literal (Loc,
677 Strval => Excep_Image))));
681 Make_Procedure_Call_Statement (Loc,
682 Name => New_Reference_To
683 (RTE (RE_Register_VMS_Exception), Loc),
684 Parameter_Associations => New_List (
686 Unchecked_Convert_To (RTE (RE_Exception_Data_Ptr),
687 Make_Attribute_Reference (Loc,
688 Prefix => New_Occurrence_Of (Id, Loc),
689 Attribute_Name => Name_Unrestricted_Access)))));
691 Analyze_And_Resolve (Code, RTE (RE_Exception_Code));
695 if No (Interface_Name (Id)) then
696 Set_Interface_Name (Id,
699 Strval => Excep_Image));
704 end Expand_Pragma_Import_Export_Exception;
706 ------------------------------------
707 -- Expand_Pragma_Inspection_Point --
708 ------------------------------------
710 -- If no argument is given, then we supply a default argument list that
711 -- includes all objects declared at the source level in all subprograms
712 -- that enclose the inspection point pragma.
714 procedure Expand_Pragma_Inspection_Point (N : Node_Id) is
715 Loc : constant Source_Ptr := Sloc (N);
722 if No (Pragma_Argument_Associations (N)) then
726 while S /= Standard_Standard loop
727 E := First_Entity (S);
728 while Present (E) loop
729 if Comes_From_Source (E)
730 and then Is_Object (E)
731 and then not Is_Entry_Formal (E)
732 and then Ekind (E) /= E_Component
733 and then Ekind (E) /= E_Discriminant
734 and then Ekind (E) /= E_Generic_In_Parameter
735 and then Ekind (E) /= E_Generic_In_Out_Parameter
738 Make_Pragma_Argument_Association (Loc,
739 Expression => New_Occurrence_Of (E, Loc)));
748 Set_Pragma_Argument_Associations (N, A);
751 -- Expand the arguments of the pragma. Expanding an entity reference
752 -- is a noop, except in a protected operation, where a reference may
753 -- have to be transformed into a reference to the corresponding prival.
754 -- Are there other pragmas that may require this ???
756 Assoc := First (Pragma_Argument_Associations (N));
758 while Present (Assoc) loop
759 Expand (Expression (Assoc));
762 end Expand_Pragma_Inspection_Point;
764 --------------------------------------
765 -- Expand_Pragma_Interrupt_Priority --
766 --------------------------------------
768 -- Supply default argument if none exists (System.Interrupt_Priority'Last)
770 procedure Expand_Pragma_Interrupt_Priority (N : Node_Id) is
771 Loc : constant Source_Ptr := Sloc (N);
774 if No (Pragma_Argument_Associations (N)) then
775 Set_Pragma_Argument_Associations (N, New_List (
776 Make_Pragma_Argument_Association (Loc,
778 Make_Attribute_Reference (Loc,
780 New_Occurrence_Of (RTE (RE_Interrupt_Priority), Loc),
781 Attribute_Name => Name_Last))));
783 end Expand_Pragma_Interrupt_Priority;
785 --------------------------------
786 -- Expand_Pragma_Psect_Object --
787 --------------------------------
789 -- Convert to Common_Object, and expand the resulting pragma
791 procedure Expand_Pragma_Psect_Object (N : Node_Id)
792 renames Expand_Pragma_Common_Object;
794 -------------------------------------
795 -- Expand_Pragma_Relative_Deadline --
796 -------------------------------------
798 procedure Expand_Pragma_Relative_Deadline (N : Node_Id) is
799 P : constant Node_Id := Parent (N);
800 Loc : constant Source_Ptr := Sloc (N);
803 -- Expand the pragma only in the case of the main subprogram. For tasks
804 -- the expansion is done in exp_ch9. Generate a call to Set_Deadline
805 -- at Clock plus the relative deadline specified in the pragma. Time
806 -- values are translated into Duration to allow for non-private
807 -- addition operation.
809 if Nkind (P) = N_Subprogram_Body then
812 Make_Procedure_Call_Statement (Loc,
813 Name => New_Reference_To (RTE (RE_Set_Deadline), Loc),
814 Parameter_Associations => New_List (
815 Unchecked_Convert_To (RTE (RO_RT_Time),
818 Make_Function_Call (Loc,
819 New_Reference_To (RTE (RO_RT_To_Duration), Loc),
820 New_List (Make_Function_Call (Loc,
821 New_Reference_To (RTE (RE_Clock), Loc)))),
823 Unchecked_Convert_To (Standard_Duration, Arg1 (N)))))));
827 end Expand_Pragma_Relative_Deadline;