1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, 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 Loc
: constant Source_Ptr
:= Sloc
(N
);
273 Cond
: constant Node_Id
:= Arg2
(N
);
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 -- Note that the reason we do not always generate a direct raise is that
314 -- the form in which the procedure is called allows for more efficient
315 -- breakpointing of assertion errors.
317 -- Generate the appropriate if statement. Note that we consider this to
318 -- be an explicit conditional in the source, not an implicit if, so we
319 -- do not call Make_Implicit_If_Statement.
321 -- Case where we generate a direct raise
324 or else Restriction_Active
(No_Exception_Propagation
))
325 and then Present
(Find_Local_Handler
(RTE
(RE_Assert_Failure
), N
))
328 Make_If_Statement
(Loc
,
332 Then_Statements
=> New_List
(
333 Make_Raise_Statement
(Loc
,
335 New_Reference_To
(RTE
(RE_Assert_Failure
), Loc
)))));
337 -- Case where we call the procedure
340 -- First, we need to prepare the string argument
342 -- If we have a message given, use it
344 if Present
(Arg3
(N
)) then
347 -- Otherwise string is "name failed at location" except in the case
348 -- of Assertion where "name failed at" is omitted.
351 if Nam
= Name_Assertion
then
354 Get_Name_String
(Nam
);
355 Set_Casing
(Identifier_Casing
(Current_Source_File
));
356 Add_Str_To_Name_Buffer
(" failed at ");
359 Build_Location_String
(Loc
);
361 Make_String_Literal
(Loc
,
362 Strval
=> String_From_Name_Buffer
);
365 -- Now rewrite as an if statement
368 Make_If_Statement
(Loc
,
372 Then_Statements
=> New_List
(
373 Make_Procedure_Call_Statement
(Loc
,
375 New_Reference_To
(RTE
(RE_Raise_Assert_Failure
), Loc
),
376 Parameter_Associations
=> New_List
(Msg
)))));
381 -- If new condition is always false, give a warning
383 if Warn_On_Assertion_Failure
384 and then Nkind
(N
) = N_Procedure_Call_Statement
385 and then Is_RTE
(Entity
(Name
(N
)), RE_Raise_Assert_Failure
)
387 -- If original condition was a Standard.False, we assume that this is
388 -- indeed intended to raise assert error and no warning is required.
390 if Is_Entity_Name
(Original_Node
(Cond
))
391 and then Entity
(Original_Node
(Cond
)) = Standard_False
394 elsif Nam
= Name_Assertion
then
395 Error_Msg_N
("?assertion will fail at run-time", N
);
397 Error_Msg_N
("?check will fail at run time", N
);
400 end Expand_Pragma_Check
;
402 ---------------------------------
403 -- Expand_Pragma_Common_Object --
404 ---------------------------------
406 -- Use a machine attribute to replicate semantic effect in DEC Ada
408 -- pragma Machine_Attribute (intern_name, "common_object", extern_name);
410 -- For now we do nothing with the size attribute ???
412 -- Note: Psect_Object shares this processing
414 procedure Expand_Pragma_Common_Object
(N
: Node_Id
) is
415 Loc
: constant Source_Ptr
:= Sloc
(N
);
417 Internal
: constant Node_Id
:= Arg1
(N
);
418 External
: constant Node_Id
:= Arg2
(N
);
421 -- Psect value upper cased as string literal
423 Iloc
: constant Source_Ptr
:= Sloc
(Internal
);
424 Eloc
: constant Source_Ptr
:= Sloc
(External
);
428 -- Acquire Psect value and fold to upper case
430 if Present
(External
) then
431 if Nkind
(External
) = N_String_Literal
then
432 String_To_Name_Buffer
(Strval
(External
));
434 Get_Name_String
(Chars
(External
));
440 Make_String_Literal
(Eloc
,
441 Strval
=> String_From_Name_Buffer
);
444 Get_Name_String
(Chars
(Internal
));
447 Make_String_Literal
(Iloc
,
448 Strval
=> String_From_Name_Buffer
);
451 Ploc
:= Sloc
(Psect
);
455 Insert_After_And_Analyze
(N
,
457 Chars
=> Name_Machine_Attribute
,
458 Pragma_Argument_Associations
=> New_List
(
459 Make_Pragma_Argument_Association
(Iloc
,
460 Expression
=> New_Copy_Tree
(Internal
)),
461 Make_Pragma_Argument_Association
(Eloc
,
463 Make_String_Literal
(Sloc
=> Ploc
,
464 Strval
=> "common_object")),
465 Make_Pragma_Argument_Association
(Ploc
,
466 Expression
=> New_Copy_Tree
(Psect
)))));
468 end Expand_Pragma_Common_Object
;
470 ---------------------------------------
471 -- Expand_Pragma_Import_Or_Interface --
472 ---------------------------------------
474 -- When applied to a variable, the default initialization must not be
475 -- done. As it is already done when the pragma is found, we just get rid
476 -- of the call the initialization procedure which followed the object
477 -- declaration. The call is inserted after the declaration, but validity
478 -- checks may also have been inserted and the initialization call does
479 -- not necessarily appear immediately after the object declaration.
481 -- We can't use the freezing mechanism for this purpose, since we
482 -- have to elaborate the initialization expression when it is first
483 -- seen (i.e. this elaboration cannot be deferred to the freeze point).
485 procedure Expand_Pragma_Import_Or_Interface
(N
: Node_Id
) is
486 Def_Id
: constant Entity_Id
:= Entity
(Arg2
(N
));
490 if Ekind
(Def_Id
) = E_Variable
then
492 -- Find generated initialization call for object, if any
494 Init_Call
:= Find_Init_Call
(Def_Id
, Rep_Clause
=> N
);
495 if Present
(Init_Call
) then
499 -- Any default initialization expression should be removed
500 -- (e.g., null defaults for access objects, zero initialization
501 -- of packed bit arrays). Imported objects aren't allowed to
502 -- have explicit initialization, so the expression must have
503 -- been generated by the compiler.
505 if No
(Init_Call
) and then Present
(Expression
(Parent
(Def_Id
))) then
506 Set_Expression
(Parent
(Def_Id
), Empty
);
509 end Expand_Pragma_Import_Or_Interface
;
511 -------------------------------------------
512 -- Expand_Pragma_Import_Export_Exception --
513 -------------------------------------------
515 -- For a VMS exception fix up the language field with "VMS"
516 -- instead of "Ada" (gigi needs this), create a constant that will be the
517 -- value of the VMS condition code and stuff the Interface_Name field
518 -- with the unexpanded name of the exception (if not already set).
519 -- For a Ada exception, just stuff the Interface_Name field
520 -- with the unexpanded name of the exception (if not already set).
522 procedure Expand_Pragma_Import_Export_Exception
(N
: Node_Id
) is
524 -- This pragma is only effective on OpenVMS systems, it was ignored
525 -- on non-VMS systems, and we need to ignore it here as well.
527 if not OpenVMS_On_Target
then
532 Id
: constant Entity_Id
:= Entity
(Arg1
(N
));
533 Call
: constant Node_Id
:= Register_Exception_Call
(Id
);
534 Loc
: constant Source_Ptr
:= Sloc
(N
);
537 if Present
(Call
) then
539 Excep_Internal
: constant Node_Id
:=
540 Make_Defining_Identifier
541 (Loc
, New_Internal_Name
('V'));
543 Export_Pragma
: Node_Id
;
544 Excep_Alias
: Node_Id
;
545 Excep_Object
: Node_Id
;
546 Excep_Image
: String_Id
;
552 if Present
(Interface_Name
(Id
)) then
553 Excep_Image
:= Strval
(Interface_Name
(Id
));
555 Get_Name_String
(Chars
(Id
));
557 Excep_Image
:= String_From_Name_Buffer
;
560 Exdata
:= Component_Associations
(Expression
(Parent
(Id
)));
562 if Is_VMS_Exception
(Id
) then
563 Lang_Char
:= Next
(First
(Exdata
));
565 -- Change the one-character language designator to 'V'
567 Rewrite
(Expression
(Lang_Char
),
568 Make_Character_Literal
(Loc
,
570 Char_Literal_Value
=>
571 UI_From_Int
(Character'Pos ('V'))));
572 Analyze
(Expression
(Lang_Char
));
574 if Exception_Code
(Id
) /= No_Uint
then
576 Make_Integer_Literal
(Loc
,
577 Intval
=> Exception_Code
(Id
));
580 Make_Object_Declaration
(Loc
,
581 Defining_Identifier
=> Excep_Internal
,
583 New_Reference_To
(RTE
(RE_Exception_Code
), Loc
));
585 Insert_Action
(N
, Excep_Object
);
586 Analyze
(Excep_Object
);
590 (UI_To_Int
(Exception_Code
(Id
)) / 8 * 8);
597 (Make_Pragma_Argument_Association
600 New_Reference_To
(Excep_Internal
, Loc
)),
602 Make_Pragma_Argument_Association
607 Strval
=> End_String
))));
609 Insert_Action
(N
, Excep_Alias
);
610 Analyze
(Excep_Alias
);
617 (Make_Pragma_Argument_Association
619 Expression
=> Make_Identifier
(Loc
, Name_C
)),
621 Make_Pragma_Argument_Association
624 New_Reference_To
(Excep_Internal
, Loc
)),
626 Make_Pragma_Argument_Association
631 Strval
=> Excep_Image
)),
633 Make_Pragma_Argument_Association
638 Strval
=> Excep_Image
))));
640 Insert_Action
(N
, Export_Pragma
);
641 Analyze
(Export_Pragma
);
645 Unchecked_Convert_To
(RTE
(RE_Exception_Code
),
646 Make_Function_Call
(Loc
,
648 New_Reference_To
(RTE
(RE_Import_Value
), Loc
),
649 Parameter_Associations
=> New_List
650 (Make_String_Literal
(Loc
,
651 Strval
=> Excep_Image
))));
655 Make_Procedure_Call_Statement
(Loc
,
656 Name
=> New_Reference_To
657 (RTE
(RE_Register_VMS_Exception
), Loc
),
658 Parameter_Associations
=> New_List
(
660 Unchecked_Convert_To
(RTE
(RE_Exception_Data_Ptr
),
661 Make_Attribute_Reference
(Loc
,
662 Prefix
=> New_Occurrence_Of
(Id
, Loc
),
663 Attribute_Name
=> Name_Unrestricted_Access
)))));
665 Analyze_And_Resolve
(Code
, RTE
(RE_Exception_Code
));
669 if No
(Interface_Name
(Id
)) then
670 Set_Interface_Name
(Id
,
673 Strval
=> Excep_Image
));
678 end Expand_Pragma_Import_Export_Exception
;
680 ------------------------------------
681 -- Expand_Pragma_Inspection_Point --
682 ------------------------------------
684 -- If no argument is given, then we supply a default argument list that
685 -- includes all objects declared at the source level in all subprograms
686 -- that enclose the inspection point pragma.
688 procedure Expand_Pragma_Inspection_Point
(N
: Node_Id
) is
689 Loc
: constant Source_Ptr
:= Sloc
(N
);
696 if No
(Pragma_Argument_Associations
(N
)) then
700 while S
/= Standard_Standard
loop
701 E
:= First_Entity
(S
);
702 while Present
(E
) loop
703 if Comes_From_Source
(E
)
704 and then Is_Object
(E
)
705 and then not Is_Entry_Formal
(E
)
706 and then Ekind
(E
) /= E_Component
707 and then Ekind
(E
) /= E_Discriminant
708 and then Ekind
(E
) /= E_Generic_In_Parameter
709 and then Ekind
(E
) /= E_Generic_In_Out_Parameter
712 Make_Pragma_Argument_Association
(Loc
,
713 Expression
=> New_Occurrence_Of
(E
, Loc
)));
722 Set_Pragma_Argument_Associations
(N
, A
);
725 -- Expand the arguments of the pragma. Expanding an entity reference
726 -- is a noop, except in a protected operation, where a reference may
727 -- have to be transformed into a reference to the corresponding prival.
728 -- Are there other pragmas that may require this ???
730 Assoc
:= First
(Pragma_Argument_Associations
(N
));
732 while Present
(Assoc
) loop
733 Expand
(Expression
(Assoc
));
736 end Expand_Pragma_Inspection_Point
;
738 --------------------------------------
739 -- Expand_Pragma_Interrupt_Priority --
740 --------------------------------------
742 -- Supply default argument if none exists (System.Interrupt_Priority'Last)
744 procedure Expand_Pragma_Interrupt_Priority
(N
: Node_Id
) is
745 Loc
: constant Source_Ptr
:= Sloc
(N
);
748 if No
(Pragma_Argument_Associations
(N
)) then
749 Set_Pragma_Argument_Associations
(N
, New_List
(
750 Make_Pragma_Argument_Association
(Loc
,
752 Make_Attribute_Reference
(Loc
,
754 New_Occurrence_Of
(RTE
(RE_Interrupt_Priority
), Loc
),
755 Attribute_Name
=> Name_Last
))));
757 end Expand_Pragma_Interrupt_Priority
;
759 --------------------------------
760 -- Expand_Pragma_Psect_Object --
761 --------------------------------
763 -- Convert to Common_Object, and expand the resulting pragma
765 procedure Expand_Pragma_Psect_Object
(N
: Node_Id
)
766 renames Expand_Pragma_Common_Object
;
768 -------------------------------------
769 -- Expand_Pragma_Relative_Deadline --
770 -------------------------------------
772 procedure Expand_Pragma_Relative_Deadline
(N
: Node_Id
) is
773 P
: constant Node_Id
:= Parent
(N
);
774 Loc
: constant Source_Ptr
:= Sloc
(N
);
777 -- Expand the pragma only in the case of the main subprogram. For tasks
778 -- the expansion is done in exp_ch9. Generate a call to Set_Deadline
779 -- at Clock plus the relative deadline specified in the pragma. Time
780 -- values are translated into Duration to allow for non-private
781 -- addition operation.
783 if Nkind
(P
) = N_Subprogram_Body
then
786 Make_Procedure_Call_Statement
(Loc
,
787 Name
=> New_Reference_To
(RTE
(RE_Set_Deadline
), Loc
),
788 Parameter_Associations
=> New_List
(
789 Unchecked_Convert_To
(RTE
(RO_RT_Time
),
792 Make_Function_Call
(Loc
,
793 New_Reference_To
(RTE
(RO_RT_To_Duration
), Loc
),
794 New_List
(Make_Function_Call
(Loc
,
795 New_Reference_To
(RTE
(RE_Clock
), Loc
)))),
797 Unchecked_Convert_To
(Standard_Duration
, Arg1
(N
)))))));
801 end Expand_Pragma_Relative_Deadline
;