1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, 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 Checks
; use Checks
;
28 with Einfo
; use Einfo
;
29 with Elists
; use Elists
;
30 with Errout
; use Errout
;
31 with Exp_Atag
; use Exp_Atag
;
32 with Exp_Ch4
; use Exp_Ch4
;
33 with Exp_Ch7
; use Exp_Ch7
;
34 with Exp_Ch11
; use Exp_Ch11
;
35 with Exp_Code
; use Exp_Code
;
36 with Exp_Fixd
; use Exp_Fixd
;
37 with Exp_Util
; use Exp_Util
;
38 with Freeze
; use Freeze
;
39 with Namet
; use Namet
;
40 with Nmake
; use Nmake
;
41 with Nlists
; use Nlists
;
42 with Restrict
; use Restrict
;
43 with Rident
; use Rident
;
44 with Rtsfind
; use Rtsfind
;
46 with Sem_Eval
; use Sem_Eval
;
47 with Sem_Res
; use Sem_Res
;
48 with Sem_Util
; use Sem_Util
;
49 with Sinfo
; use Sinfo
;
50 with Sinput
; use Sinput
;
51 with Snames
; use Snames
;
52 with Stand
; use Stand
;
53 with Stringt
; use Stringt
;
54 with Tbuild
; use Tbuild
;
55 with Uintp
; use Uintp
;
56 with Urealp
; use Urealp
;
58 package body Exp_Intr
is
60 -----------------------
61 -- Local Subprograms --
62 -----------------------
64 procedure Expand_Is_Negative
(N
: Node_Id
);
65 -- Expand a call to the intrinsic Is_Negative function
67 procedure Expand_Dispatching_Constructor_Call
(N
: Node_Id
);
68 -- Expand a call to an instantiation of Generic_Dispatching_Constructor
69 -- into a dispatching call to the actual subprogram associated with the
70 -- Constructor formal subprogram, passing it the Parameters actual of
71 -- the call to the instantiation and dispatching based on call's Tag
74 procedure Expand_Exception_Call
(N
: Node_Id
; Ent
: RE_Id
);
75 -- Expand a call to Exception_Information/Message/Name. The first
76 -- parameter, N, is the node for the function call, and Ent is the
77 -- entity for the corresponding routine in the Ada.Exceptions package.
79 procedure Expand_Import_Call
(N
: Node_Id
);
80 -- Expand a call to Import_Address/Longest_Integer/Value. The parameter
81 -- N is the node for the function call.
83 procedure Expand_Shift
(N
: Node_Id
; E
: Entity_Id
; K
: Node_Kind
);
84 -- Expand an intrinsic shift operation, N and E are from the call to
85 -- Expand_Intrinsic_Call (call node and subprogram spec entity) and
86 -- K is the kind for the shift node
88 procedure Expand_Unc_Conversion
(N
: Node_Id
; E
: Entity_Id
);
89 -- Expand a call to an instantiation of Unchecked_Convertion into a node
90 -- N_Unchecked_Type_Conversion.
92 procedure Expand_Unc_Deallocation
(N
: Node_Id
);
93 -- Expand a call to an instantiation of Unchecked_Deallocation into a node
94 -- N_Free_Statement and appropriate context.
96 procedure Expand_To_Address
(N
: Node_Id
);
97 procedure Expand_To_Pointer
(N
: Node_Id
);
98 -- Expand a call to corresponding function, declared in an instance of
99 -- System.Addess_To_Access_Conversions.
101 procedure Expand_Source_Info
(N
: Node_Id
; Nam
: Name_Id
);
102 -- Rewrite the node by the appropriate string or positive constant.
103 -- Nam can be one of the following:
104 -- Name_File - expand string that is the name of source file
105 -- Name_Line - expand integer line number
106 -- Name_Source_Location - expand string of form file:line
107 -- Name_Enclosing_Entity - expand string with name of enclosing entity
109 -----------------------------------------
110 -- Expand_Dispatching_Constructor_Call --
111 -----------------------------------------
113 -- Transform a call to an instantiation of Generic_Dispatching_Constructor
116 -- GDC_Instance (The_Tag, Parameters'Access)
118 -- to a class-wide conversion of a dispatching call to the actual
119 -- associated with the formal subprogram Construct, designating The_Tag
120 -- as the controlling tag of the call:
122 -- T'Class (Construct'Actual (Params)) -- Controlling tag is The_Tag
124 -- which will eventually be expanded to the following:
126 -- T'Class (The_Tag.all (Construct'Actual'Index).all (Params))
128 -- A class-wide membership test is also generated, preceding the call, to
129 -- ensure that the controlling tag denotes a type in T'Class.
131 procedure Expand_Dispatching_Constructor_Call
(N
: Node_Id
) is
132 Loc
: constant Source_Ptr
:= Sloc
(N
);
133 Tag_Arg
: constant Node_Id
:= First_Actual
(N
);
134 Param_Arg
: constant Node_Id
:= Next_Actual
(Tag_Arg
);
135 Subp_Decl
: constant Node_Id
:= Parent
(Parent
(Entity
(Name
(N
))));
136 Inst_Pkg
: constant Node_Id
:= Parent
(Subp_Decl
);
137 Act_Rename
: Node_Id
;
138 Act_Constr
: Entity_Id
;
139 Result_Typ
: Entity_Id
;
140 Cnstr_Call
: Node_Id
;
143 -- The subprogram is the third actual in the instantiation, and is
144 -- retrieved from the corresponding renaming declaration. However,
145 -- freeze nodes may appear before, so we retrieve the declaration
146 -- with an explicit loop.
148 Act_Rename
:= First
(Visible_Declarations
(Inst_Pkg
));
149 while Nkind
(Act_Rename
) /= N_Subprogram_Renaming_Declaration
loop
153 Act_Constr
:= Entity
(Name
(Act_Rename
));
154 Result_Typ
:= Class_Wide_Type
(Etype
(Act_Constr
));
156 -- Ada 2005 (AI-251): If the result is an interface type, the function
157 -- returns a class-wide interface type (otherwise the resulting object
158 -- would be abstract!)
160 if Is_Interface
(Etype
(Act_Constr
)) then
161 Set_Etype
(Act_Constr
, Result_Typ
);
164 -- Create the call to the actual Constructor function
167 Make_Function_Call
(Loc
,
168 Name
=> New_Occurrence_Of
(Act_Constr
, Loc
),
169 Parameter_Associations
=> New_List
(Relocate_Node
(Param_Arg
)));
171 -- Establish its controlling tag from the tag passed to the instance
172 -- The tag may be given by a function call, in which case a temporary
173 -- should be generated now, to prevent out-of-order insertions during
174 -- the expansion of that call when stack-checking is enabled.
176 Remove_Side_Effects
(Tag_Arg
);
177 Set_Controlling_Argument
(Cnstr_Call
, Relocate_Node
(Tag_Arg
));
179 -- Rewrite and analyze the call to the instance as a class-wide
180 -- conversion of the call to the actual constructor.
182 Rewrite
(N
, Convert_To
(Result_Typ
, Cnstr_Call
));
183 Analyze_And_Resolve
(N
, Etype
(Act_Constr
));
185 -- Do not generate a run-time check on the built object if tag
186 -- checks are suppressed for the result type.
188 if Tag_Checks_Suppressed
(Etype
(Result_Typ
)) then
191 -- Generate a class-wide membership test to ensure that the call's tag
192 -- argument denotes a type within the class. We must keep separate the
193 -- case in which the Result_Type of the constructor function is a tagged
194 -- type from the case in which it is an abstract interface because the
195 -- run-time subprogram required to check these cases differ (and have
196 -- one difference in their parameters profile).
198 -- Call CW_Membership if the Result_Type is a tagged type to look for
199 -- the tag in the table of ancestor tags.
201 elsif not Is_Interface
(Result_Typ
) then
203 Make_Implicit_If_Statement
(N
,
206 Build_CW_Membership
(Loc
,
207 Obj_Tag_Node
=> Duplicate_Subexpr
(Tag_Arg
),
210 Node
(First_Elmt
(Access_Disp_Table
(
211 Root_Type
(Result_Typ
)))), Loc
))),
213 New_List
(Make_Raise_Statement
(Loc
,
214 New_Occurrence_Of
(RTE
(RE_Tag_Error
), Loc
)))));
216 -- Call IW_Membership test if the Result_Type is an abstract interface
217 -- to look for the tag in the table of interface tags.
221 Make_Implicit_If_Statement
(N
,
224 Make_Function_Call
(Loc
,
225 Name
=> New_Occurrence_Of
(RTE
(RE_IW_Membership
), Loc
),
226 Parameter_Associations
=> New_List
(
227 Make_Attribute_Reference
(Loc
,
228 Prefix
=> Duplicate_Subexpr
(Tag_Arg
),
229 Attribute_Name
=> Name_Address
),
232 Node
(First_Elmt
(Access_Disp_Table
(
233 Root_Type
(Result_Typ
)))), Loc
)))),
236 Make_Raise_Statement
(Loc
,
237 Name
=> New_Occurrence_Of
(RTE
(RE_Tag_Error
), Loc
)))));
239 end Expand_Dispatching_Constructor_Call
;
241 ---------------------------
242 -- Expand_Exception_Call --
243 ---------------------------
245 -- If the function call is not within an exception handler, then the call
246 -- is replaced by a null string. Otherwise the appropriate routine in
247 -- Ada.Exceptions is called passing the choice parameter specification
248 -- from the enclosing handler. If the enclosing handler lacks a choice
249 -- parameter, then one is supplied.
251 procedure Expand_Exception_Call
(N
: Node_Id
; Ent
: RE_Id
) is
252 Loc
: constant Source_Ptr
:= Sloc
(N
);
257 -- Climb up parents to see if we are in exception handler
261 -- Case of not in exception handler, replace by null string
265 Make_String_Literal
(Loc
,
269 -- Case of in exception handler
271 elsif Nkind
(P
) = N_Exception_Handler
then
273 -- Handler cannot be used for a local raise, and furthermore, this
274 -- is a violation of the No_Exception_Propagation restriction.
276 Set_Local_Raise_Not_OK
(P
);
277 Check_Restriction
(No_Exception_Propagation
, N
);
279 -- If no choice parameter present, then put one there. Note that
280 -- we do not need to put it on the entity chain, since no one will
281 -- be referencing it by normal visibility methods.
283 if No
(Choice_Parameter
(P
)) then
284 E
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('E'));
285 Set_Choice_Parameter
(P
, E
);
286 Set_Ekind
(E
, E_Variable
);
287 Set_Etype
(E
, RTE
(RE_Exception_Occurrence
));
288 Set_Scope
(E
, Current_Scope
);
292 Make_Function_Call
(Loc
,
293 Name
=> New_Occurrence_Of
(RTE
(Ent
), Loc
),
294 Parameter_Associations
=> New_List
(
295 New_Occurrence_Of
(Choice_Parameter
(P
), Loc
))));
305 Analyze_And_Resolve
(N
, Standard_String
);
306 end Expand_Exception_Call
;
308 ------------------------
309 -- Expand_Import_Call --
310 ------------------------
312 -- The function call must have a static string as its argument. We create
313 -- a dummy variable which uses this string as the external name in an
314 -- Import pragma. The result is then obtained as the address of this
315 -- dummy variable, converted to the appropriate target type.
317 procedure Expand_Import_Call
(N
: Node_Id
) is
318 Loc
: constant Source_Ptr
:= Sloc
(N
);
319 Ent
: constant Entity_Id
:= Entity
(Name
(N
));
320 Str
: constant Node_Id
:= First_Actual
(N
);
324 Dum
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('D'));
326 Insert_Actions
(N
, New_List
(
327 Make_Object_Declaration
(Loc
,
328 Defining_Identifier
=> Dum
,
330 New_Occurrence_Of
(Standard_Character
, Loc
)),
333 Chars
=> Name_Import
,
334 Pragma_Argument_Associations
=> New_List
(
335 Make_Pragma_Argument_Association
(Loc
,
336 Expression
=> Make_Identifier
(Loc
, Name_Ada
)),
338 Make_Pragma_Argument_Association
(Loc
,
339 Expression
=> Make_Identifier
(Loc
, Chars
(Dum
))),
341 Make_Pragma_Argument_Association
(Loc
,
342 Chars
=> Name_Link_Name
,
343 Expression
=> Relocate_Node
(Str
))))));
346 Unchecked_Convert_To
(Etype
(Ent
),
347 Make_Attribute_Reference
(Loc
,
348 Attribute_Name
=> Name_Address
,
349 Prefix
=> Make_Identifier
(Loc
, Chars
(Dum
)))));
351 Analyze_And_Resolve
(N
, Etype
(Ent
));
352 end Expand_Import_Call
;
354 ---------------------------
355 -- Expand_Intrinsic_Call --
356 ---------------------------
358 procedure Expand_Intrinsic_Call
(N
: Node_Id
; E
: Entity_Id
) is
362 -- If the intrinsic subprogram is generic, gets its original name
364 if Present
(Parent
(E
))
365 and then Present
(Generic_Parent
(Parent
(E
)))
367 Nam
:= Chars
(Generic_Parent
(Parent
(E
)));
372 if Nam
= Name_Asm
then
375 elsif Nam
= Name_Divide
then
376 Expand_Decimal_Divide_Call
(N
);
378 elsif Nam
= Name_Exception_Information
then
379 Expand_Exception_Call
(N
, RE_Exception_Information
);
381 elsif Nam
= Name_Exception_Message
then
382 Expand_Exception_Call
(N
, RE_Exception_Message
);
384 elsif Nam
= Name_Exception_Name
then
385 Expand_Exception_Call
(N
, RE_Exception_Name_Simple
);
387 elsif Nam
= Name_Generic_Dispatching_Constructor
then
388 Expand_Dispatching_Constructor_Call
(N
);
390 elsif Nam
= Name_Import_Address
392 Nam
= Name_Import_Largest_Value
394 Nam
= Name_Import_Value
396 Expand_Import_Call
(N
);
398 elsif Nam
= Name_Is_Negative
then
399 Expand_Is_Negative
(N
);
401 elsif Nam
= Name_Rotate_Left
then
402 Expand_Shift
(N
, E
, N_Op_Rotate_Left
);
404 elsif Nam
= Name_Rotate_Right
then
405 Expand_Shift
(N
, E
, N_Op_Rotate_Right
);
407 elsif Nam
= Name_Shift_Left
then
408 Expand_Shift
(N
, E
, N_Op_Shift_Left
);
410 elsif Nam
= Name_Shift_Right
then
411 Expand_Shift
(N
, E
, N_Op_Shift_Right
);
413 elsif Nam
= Name_Shift_Right_Arithmetic
then
414 Expand_Shift
(N
, E
, N_Op_Shift_Right_Arithmetic
);
416 elsif Nam
= Name_Unchecked_Conversion
then
417 Expand_Unc_Conversion
(N
, E
);
419 elsif Nam
= Name_Unchecked_Deallocation
then
420 Expand_Unc_Deallocation
(N
);
422 elsif Nam
= Name_To_Address
then
423 Expand_To_Address
(N
);
425 elsif Nam
= Name_To_Pointer
then
426 Expand_To_Pointer
(N
);
428 elsif Nam
= Name_File
429 or else Nam
= Name_Line
430 or else Nam
= Name_Source_Location
431 or else Nam
= Name_Enclosing_Entity
433 Expand_Source_Info
(N
, Nam
);
435 -- If we have a renaming, expand the call to the original operation,
436 -- which must itself be intrinsic, since renaming requires matching
437 -- conventions and this has already been checked.
439 elsif Present
(Alias
(E
)) then
440 Expand_Intrinsic_Call
(N
, Alias
(E
));
442 -- The only other case is where an external name was specified,
443 -- since this is the only way that an otherwise unrecognized
444 -- name could escape the checking in Sem_Prag. Nothing needs
445 -- to be done in such a case, since we pass such a call to the
446 -- back end unchanged.
451 end Expand_Intrinsic_Call
;
453 ------------------------
454 -- Expand_Is_Negative --
455 ------------------------
457 procedure Expand_Is_Negative
(N
: Node_Id
) is
458 Loc
: constant Source_Ptr
:= Sloc
(N
);
459 Opnd
: constant Node_Id
:= Relocate_Node
(First_Actual
(N
));
463 -- We replace the function call by the following expression
465 -- if Opnd < 0.0 then
468 -- if Opnd > 0.0 then
471 -- Float_Unsigned!(Float (Opnd)) /= 0
476 Make_Conditional_Expression
(Loc
,
477 Expressions
=> New_List
(
479 Left_Opnd
=> Duplicate_Subexpr
(Opnd
),
480 Right_Opnd
=> Make_Real_Literal
(Loc
, Ureal_0
)),
482 New_Occurrence_Of
(Standard_True
, Loc
),
484 Make_Conditional_Expression
(Loc
,
485 Expressions
=> New_List
(
487 Left_Opnd
=> Duplicate_Subexpr_No_Checks
(Opnd
),
488 Right_Opnd
=> Make_Real_Literal
(Loc
, Ureal_0
)),
490 New_Occurrence_Of
(Standard_False
, Loc
),
495 (RTE
(RE_Float_Unsigned
),
498 Duplicate_Subexpr_No_Checks
(Opnd
))),
500 Make_Integer_Literal
(Loc
, 0)))))));
502 Analyze_And_Resolve
(N
, Standard_Boolean
);
503 end Expand_Is_Negative
;
509 -- This procedure is used to convert a call to a shift function to the
510 -- corresponding operator node. This conversion is not done by the usual
511 -- circuit for converting calls to operator functions (e.g. "+"(1,2)) to
512 -- operator nodes, because shifts are not predefined operators.
514 -- As a result, whenever a shift is used in the source program, it will
515 -- remain as a call until converted by this routine to the operator node
516 -- form which Gigi is expecting to see.
518 -- Note: it is possible for the expander to generate shift operator nodes
519 -- directly, which will be analyzed in the normal manner by calling Analyze
520 -- and Resolve. Such shift operator nodes will not be seen by Expand_Shift.
522 procedure Expand_Shift
(N
: Node_Id
; E
: Entity_Id
; K
: Node_Kind
) is
523 Loc
: constant Source_Ptr
:= Sloc
(N
);
524 Typ
: constant Entity_Id
:= Etype
(N
);
525 Left
: constant Node_Id
:= First_Actual
(N
);
526 Right
: constant Node_Id
:= Next_Actual
(Left
);
527 Ltyp
: constant Node_Id
:= Etype
(Left
);
528 Rtyp
: constant Node_Id
:= Etype
(Right
);
532 Snode
:= New_Node
(K
, Loc
);
533 Set_Left_Opnd
(Snode
, Relocate_Node
(Left
));
534 Set_Right_Opnd
(Snode
, Relocate_Node
(Right
));
535 Set_Chars
(Snode
, Chars
(E
));
536 Set_Etype
(Snode
, Base_Type
(Typ
));
537 Set_Entity
(Snode
, E
);
539 if Compile_Time_Known_Value
(Type_High_Bound
(Rtyp
))
540 and then Expr_Value
(Type_High_Bound
(Rtyp
)) < Esize
(Ltyp
)
542 Set_Shift_Count_OK
(Snode
, True);
545 -- Do the rewrite. Note that we don't call Analyze and Resolve on
546 -- this node, because it already got analyzed and resolved when
547 -- it was a function call!
553 ------------------------
554 -- Expand_Source_Info --
555 ------------------------
557 procedure Expand_Source_Info
(N
: Node_Id
; Nam
: Name_Id
) is
558 Loc
: constant Source_Ptr
:= Sloc
(N
);
561 procedure Write_Entity_Name
(E
: Entity_Id
);
562 -- Recursive procedure to construct string for qualified name of
563 -- enclosing program unit. The qualification stops at an enclosing
564 -- scope has no source name (block or loop). If entity is a subprogram
565 -- instance, skip enclosing wrapper package.
567 -----------------------
568 -- Write_Entity_Name --
569 -----------------------
571 procedure Write_Entity_Name
(E
: Entity_Id
) is
573 TDef
: constant Source_Buffer_Ptr
:=
574 Source_Text
(Get_Source_File_Index
(Sloc
(E
)));
577 -- Nothing to do if at outer level
579 if Scope
(E
) = Standard_Standard
then
582 -- If scope comes from source, write its name
584 elsif Comes_From_Source
(Scope
(E
)) then
585 Write_Entity_Name
(Scope
(E
));
586 Add_Char_To_Name_Buffer
('.');
588 -- If in wrapper package skip past it
590 elsif Is_Wrapper_Package
(Scope
(E
)) then
591 Write_Entity_Name
(Scope
(Scope
(E
)));
592 Add_Char_To_Name_Buffer
('.');
594 -- Otherwise nothing to output (happens in unnamed block statements)
600 -- Loop to output the name
602 -- is this right wrt wide char encodings ??? (no!)
605 while TDef
(SDef
) in '0' .. '9'
606 or else TDef
(SDef
) >= 'A'
607 or else TDef
(SDef
) = ASCII
.ESC
609 Add_Char_To_Name_Buffer
(TDef
(SDef
));
612 end Write_Entity_Name
;
614 -- Start of processing for Expand_Source_Info
619 if Nam
= Name_Line
then
621 Make_Integer_Literal
(Loc
,
622 Intval
=> UI_From_Int
(Int
(Get_Logical_Line_Number
(Loc
)))));
623 Analyze_And_Resolve
(N
, Standard_Positive
);
630 Get_Decoded_Name_String
631 (Reference_Name
(Get_Source_File_Index
(Loc
)));
633 when Name_Source_Location
=>
634 Build_Location_String
(Loc
);
636 when Name_Enclosing_Entity
=>
639 Ent
:= Current_Scope
;
641 -- Skip enclosing blocks to reach enclosing unit
643 while Present
(Ent
) loop
644 exit when Ekind
(Ent
) /= E_Block
645 and then Ekind
(Ent
) /= E_Loop
;
649 -- Ent now points to the relevant defining entity
652 Write_Entity_Name
(Ent
);
659 Make_String_Literal
(Loc
, Strval
=> String_From_Name_Buffer
));
660 Analyze_And_Resolve
(N
, Standard_String
);
663 Set_Is_Static_Expression
(N
);
664 end Expand_Source_Info
;
666 ---------------------------
667 -- Expand_Unc_Conversion --
668 ---------------------------
670 procedure Expand_Unc_Conversion
(N
: Node_Id
; E
: Entity_Id
) is
671 Func
: constant Entity_Id
:= Entity
(Name
(N
));
677 -- Rewrite as unchecked conversion node. Note that we must convert
678 -- the operand to the formal type of the input parameter of the
679 -- function, so that the resulting N_Unchecked_Type_Conversion
680 -- call indicates the correct types for Gigi.
682 -- Right now, we only do this if a scalar type is involved. It is
683 -- not clear if it is needed in other cases. If we do attempt to
684 -- do the conversion unconditionally, it crashes 3411-018. To be
685 -- investigated further ???
687 Conv
:= Relocate_Node
(First_Actual
(N
));
688 Ftyp
:= Etype
(First_Formal
(Func
));
690 if Is_Scalar_Type
(Ftyp
) then
691 Conv
:= Convert_To
(Ftyp
, Conv
);
692 Set_Parent
(Conv
, N
);
693 Analyze_And_Resolve
(Conv
);
696 -- The instantiation of Unchecked_Conversion creates a wrapper package,
697 -- and the target type is declared as a subtype of the actual. Recover
698 -- the actual, which is the subtype indic. in the subtype declaration
699 -- for the target type. This is semantically correct, and avoids
700 -- anomalies with access subtypes. For entities, leave type as is.
702 -- We do the analysis here, because we do not want the compiler
703 -- to try to optimize or otherwise reorganize the unchecked
708 if Is_Entity_Name
(Conv
) then
711 elsif Nkind
(Parent
(Ttyp
)) = N_Subtype_Declaration
then
712 Ttyp
:= Entity
(Subtype_Indication
(Parent
(Etype
(E
))));
714 elsif Is_Itype
(Ttyp
) then
716 Entity
(Subtype_Indication
(Associated_Node_For_Itype
(Ttyp
)));
721 Rewrite
(N
, Unchecked_Convert_To
(Ttyp
, Conv
));
725 if Nkind
(N
) = N_Unchecked_Type_Conversion
then
726 Expand_N_Unchecked_Type_Conversion
(N
);
728 end Expand_Unc_Conversion
;
730 -----------------------------
731 -- Expand_Unc_Deallocation --
732 -----------------------------
734 -- Generate the following Code :
736 -- if Arg /= null then
737 -- <Finalize_Call> (.., T'Class(Arg.all), ..); -- for controlled types
742 -- For a task, we also generate a call to Free_Task to ensure that the
743 -- task itself is freed if it is terminated, ditto for a simple protected
744 -- object, with a call to Finalize_Protection. For composite types that
745 -- have tasks or simple protected objects as components, we traverse the
746 -- structures to find and terminate those components.
748 procedure Expand_Unc_Deallocation
(N
: Node_Id
) is
749 Loc
: constant Source_Ptr
:= Sloc
(N
);
750 Arg
: constant Node_Id
:= First_Actual
(N
);
751 Typ
: constant Entity_Id
:= Etype
(Arg
);
752 Stmts
: constant List_Id
:= New_List
;
753 Rtyp
: constant Entity_Id
:= Underlying_Type
(Root_Type
(Typ
));
754 Pool
: constant Entity_Id
:= Associated_Storage_Pool
(Rtyp
);
756 Desig_T
: constant Entity_Id
:= Designated_Type
(Typ
);
764 Arg_Known_Non_Null
: constant Boolean := Known_Non_Null
(N
);
765 -- This captures whether we know the argument to be non-null so that
766 -- we can avoid the test. The reason that we need to capture this is
767 -- that we analyze some generated statements before properly attaching
768 -- them to the tree, and that can disturb current value settings.
771 if No_Pool_Assigned
(Rtyp
) then
772 Error_Msg_N
("?deallocation from empty storage pool!", N
);
775 -- Nothing to do if we know the argument is null
777 if Known_Null
(N
) then
781 -- Processing for pointer to controlled type
783 if Controlled_Type
(Desig_T
) then
785 Make_Explicit_Dereference
(Loc
,
786 Prefix
=> Duplicate_Subexpr_No_Checks
(Arg
));
788 -- If the type is tagged, then we must force dispatching on the
789 -- finalization call because the designated type may not be the
790 -- actual type of the object.
792 if Is_Tagged_Type
(Desig_T
)
793 and then not Is_Class_Wide_Type
(Desig_T
)
795 Deref
:= Unchecked_Convert_To
(Class_Wide_Type
(Desig_T
), Deref
);
797 elsif not Is_Tagged_Type
(Desig_T
) then
799 -- Set type of result, to force a conversion when needed (see
800 -- exp_ch7, Convert_View), given that Deep_Finalize may be
801 -- inherited from the parent type, and we need the type of the
802 -- expression to see whether the conversion is in fact needed.
804 Set_Etype
(Deref
, Desig_T
);
811 With_Detach
=> New_Reference_To
(Standard_True
, Loc
));
813 if Abort_Allowed
then
814 Prepend_To
(Free_Cod
,
815 Build_Runtime_Call
(Loc
, RE_Abort_Defer
));
818 Make_Block_Statement
(Loc
, Handled_Statement_Sequence
=>
819 Make_Handled_Sequence_Of_Statements
(Loc
,
820 Statements
=> Free_Cod
,
822 New_Occurrence_Of
(RTE
(RE_Abort_Undefer_Direct
), Loc
)));
824 -- We now expand the exception (at end) handler. We set a
825 -- temporary parent pointer since we have not attached Blk
830 Expand_At_End_Handler
831 (Handled_Statement_Sequence
(Blk
), Entity
(Identifier
(Blk
)));
834 -- We kill saved current values, since analyzing statements not
835 -- properly attached to the tree can set wrong current values.
840 Append_List_To
(Stmts
, Free_Cod
);
844 -- For a task type, call Free_Task before freeing the ATCB
846 if Is_Task_Type
(Desig_T
) then
848 Stat
: Node_Id
:= Prev
(N
);
853 -- An Abort followed by a Free will not do what the user
854 -- expects, because the abort is not immediate. This is
855 -- worth a friendly warning.
858 and then not Comes_From_Source
(Original_Node
(Stat
))
864 and then Nkind
(Original_Node
(Stat
)) = N_Abort_Statement
866 Stat
:= Original_Node
(Stat
);
867 Nam1
:= First
(Names
(Stat
));
868 Nam2
:= Original_Node
(First
(Parameter_Associations
(N
)));
870 if Nkind
(Nam1
) = N_Explicit_Dereference
871 and then Is_Entity_Name
(Prefix
(Nam1
))
872 and then Is_Entity_Name
(Nam2
)
873 and then Entity
(Prefix
(Nam1
)) = Entity
(Nam2
)
875 Error_Msg_N
("abort may take time to complete?", N
);
876 Error_Msg_N
("\deallocation might have no effect?", N
);
877 Error_Msg_N
("\safer to wait for termination.?", N
);
883 (Stmts
, Cleanup_Task
(N
, Duplicate_Subexpr_No_Checks
(Arg
)));
885 -- For composite types that contain tasks, recurse over the structure
886 -- to build the selectors for the task subcomponents.
888 elsif Has_Task
(Desig_T
) then
889 if Is_Record_Type
(Desig_T
) then
890 Append_List_To
(Stmts
, Cleanup_Record
(N
, Arg
, Desig_T
));
892 elsif Is_Array_Type
(Desig_T
) then
893 Append_List_To
(Stmts
, Cleanup_Array
(N
, Arg
, Desig_T
));
897 -- Same for simple protected types. Eventually call Finalize_Protection
898 -- before freeing the PO for each protected component.
900 if Is_Simple_Protected_Type
(Desig_T
) then
902 Cleanup_Protected_Object
(N
, Duplicate_Subexpr_No_Checks
(Arg
)));
904 elsif Has_Simple_Protected_Object
(Desig_T
) then
905 if Is_Record_Type
(Desig_T
) then
906 Append_List_To
(Stmts
, Cleanup_Record
(N
, Arg
, Desig_T
));
907 elsif Is_Array_Type
(Desig_T
) then
908 Append_List_To
(Stmts
, Cleanup_Array
(N
, Arg
, Desig_T
));
912 -- Normal processing for non-controlled types
914 Free_Arg
:= Duplicate_Subexpr_No_Checks
(Arg
);
915 Free_Node
:= Make_Free_Statement
(Loc
, Empty
);
916 Append_To
(Stmts
, Free_Node
);
917 Set_Storage_Pool
(Free_Node
, Pool
);
919 -- Deal with storage pool
921 if Present
(Pool
) then
923 -- Freeing the secondary stack is meaningless
925 if Is_RTE
(Pool
, RE_SS_Pool
) then
928 elsif Is_Class_Wide_Type
(Etype
(Pool
)) then
930 -- Case of a class-wide pool type: make a dispatching call
931 -- to Deallocate through the class-wide Deallocate_Any.
933 Set_Procedure_To_Call
(Free_Node
,
934 RTE
(RE_Deallocate_Any
));
937 -- Case of a specific pool type: make a statically bound call
939 Set_Procedure_To_Call
(Free_Node
,
940 Find_Prim_Op
(Etype
(Pool
), Name_Deallocate
));
944 if Present
(Procedure_To_Call
(Free_Node
)) then
946 -- For all cases of a Deallocate call, the back-end needs to be
947 -- able to compute the size of the object being freed. This may
948 -- require some adjustments for objects of dynamic size.
950 -- If the type is class wide, we generate an implicit type with the
951 -- right dynamic size, so that the deallocate call gets the right
952 -- size parameter computed by GIGI. Same for an access to
953 -- unconstrained packed array.
955 if Is_Class_Wide_Type
(Desig_T
)
957 (Is_Array_Type
(Desig_T
)
958 and then not Is_Constrained
(Desig_T
)
959 and then Is_Packed
(Desig_T
))
962 Deref
: constant Node_Id
:=
963 Make_Explicit_Dereference
(Loc
,
964 Duplicate_Subexpr_No_Checks
(Arg
));
969 Set_Etype
(Deref
, Typ
);
970 Set_Parent
(Deref
, Free_Node
);
971 D_Subtyp
:= Make_Subtype_From_Expr
(Deref
, Desig_T
);
973 if Nkind
(D_Subtyp
) in N_Has_Entity
then
974 D_Type
:= Entity
(D_Subtyp
);
977 D_Type
:= Make_Defining_Identifier
(Loc
,
978 New_Internal_Name
('A'));
980 Make_Subtype_Declaration
(Loc
,
981 Defining_Identifier
=> D_Type
,
982 Subtype_Indication
=> D_Subtyp
));
983 Freeze_Itype
(D_Type
, N
);
987 Set_Actual_Designated_Subtype
(Free_Node
, D_Type
);
993 -- Ada 2005 (AI-251): In case of abstract interface type we must
994 -- displace the pointer to reference the base of the object to
995 -- deallocate its memory.
998 -- free (Base_Address (Obj_Ptr))
1000 if Is_Interface
(Directly_Designated_Type
(Typ
)) then
1001 Set_Expression
(Free_Node
,
1002 Unchecked_Convert_To
(Typ
,
1003 Make_Function_Call
(Loc
,
1004 Name
=> New_Reference_To
(RTE
(RE_Base_Address
), Loc
),
1005 Parameter_Associations
=> New_List
(
1006 Unchecked_Convert_To
(RTE
(RE_Address
), Free_Arg
)))));
1012 Set_Expression
(Free_Node
, Free_Arg
);
1015 -- Only remaining step is to set result to null, or generate a
1016 -- raise of constraint error if the target object is "not null".
1018 if Can_Never_Be_Null
(Etype
(Arg
)) then
1020 Make_Raise_Constraint_Error
(Loc
,
1021 Reason
=> CE_Access_Check_Failed
));
1025 Lhs
: constant Node_Id
:= Duplicate_Subexpr_No_Checks
(Arg
);
1027 Set_Assignment_OK
(Lhs
);
1029 Make_Assignment_Statement
(Loc
,
1031 Expression
=> Make_Null
(Loc
)));
1035 -- If we know the argument is non-null, then make a block statement
1036 -- that contains the required statements, no need for a test.
1038 if Arg_Known_Non_Null
then
1040 Make_Block_Statement
(Loc
,
1041 Handled_Statement_Sequence
=>
1042 Make_Handled_Sequence_Of_Statements
(Loc
,
1043 Statements
=> Stmts
));
1045 -- If the argument may be null, wrap the statements inside an IF that
1046 -- does an explicit test to exclude the null case.
1050 Make_Implicit_If_Statement
(N
,
1053 Left_Opnd
=> Duplicate_Subexpr
(Arg
),
1054 Right_Opnd
=> Make_Null
(Loc
)),
1055 Then_Statements
=> Stmts
);
1060 Rewrite
(N
, Gen_Code
);
1062 end Expand_Unc_Deallocation
;
1064 -----------------------
1065 -- Expand_To_Address --
1066 -----------------------
1068 procedure Expand_To_Address
(N
: Node_Id
) is
1069 Loc
: constant Source_Ptr
:= Sloc
(N
);
1070 Arg
: constant Node_Id
:= First_Actual
(N
);
1074 Remove_Side_Effects
(Arg
);
1076 Obj
:= Make_Explicit_Dereference
(Loc
, Relocate_Node
(Arg
));
1079 Make_Conditional_Expression
(Loc
,
1080 Expressions
=> New_List
(
1082 Left_Opnd
=> New_Copy_Tree
(Arg
),
1083 Right_Opnd
=> Make_Null
(Loc
)),
1084 New_Occurrence_Of
(RTE
(RE_Null_Address
), Loc
),
1085 Make_Attribute_Reference
(Loc
,
1086 Attribute_Name
=> Name_Address
,
1089 Analyze_And_Resolve
(N
, RTE
(RE_Address
));
1090 end Expand_To_Address
;
1092 -----------------------
1093 -- Expand_To_Pointer --
1094 -----------------------
1096 procedure Expand_To_Pointer
(N
: Node_Id
) is
1097 Arg
: constant Node_Id
:= First_Actual
(N
);
1100 Rewrite
(N
, Unchecked_Convert_To
(Etype
(N
), Arg
));
1102 end Expand_To_Pointer
;