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 Targparm
; use Targparm
;
55 with Tbuild
; use Tbuild
;
56 with Uintp
; use Uintp
;
57 with Urealp
; use Urealp
;
59 package body Exp_Intr
is
61 -----------------------
62 -- Local Subprograms --
63 -----------------------
65 procedure Expand_Is_Negative
(N
: Node_Id
);
66 -- Expand a call to the intrinsic Is_Negative function
68 procedure Expand_Dispatching_Constructor_Call
(N
: Node_Id
);
69 -- Expand a call to an instantiation of Generic_Dispatching_Constructor
70 -- into a dispatching call to the actual subprogram associated with the
71 -- Constructor formal subprogram, passing it the Parameters actual of
72 -- the call to the instantiation and dispatching based on call's Tag
75 procedure Expand_Exception_Call
(N
: Node_Id
; Ent
: RE_Id
);
76 -- Expand a call to Exception_Information/Message/Name. The first
77 -- parameter, N, is the node for the function call, and Ent is the
78 -- entity for the corresponding routine in the Ada.Exceptions package.
80 procedure Expand_Import_Call
(N
: Node_Id
);
81 -- Expand a call to Import_Address/Longest_Integer/Value. The parameter
82 -- N is the node for the function call.
84 procedure Expand_Shift
(N
: Node_Id
; E
: Entity_Id
; K
: Node_Kind
);
85 -- Expand an intrinsic shift operation, N and E are from the call to
86 -- Expand_Intrinsic_Call (call node and subprogram spec entity) and
87 -- K is the kind for the shift node
89 procedure Expand_Unc_Conversion
(N
: Node_Id
; E
: Entity_Id
);
90 -- Expand a call to an instantiation of Unchecked_Convertion into a node
91 -- N_Unchecked_Type_Conversion.
93 procedure Expand_Unc_Deallocation
(N
: Node_Id
);
94 -- Expand a call to an instantiation of Unchecked_Deallocation into a node
95 -- N_Free_Statement and appropriate context.
97 procedure Expand_To_Address
(N
: Node_Id
);
98 procedure Expand_To_Pointer
(N
: Node_Id
);
99 -- Expand a call to corresponding function, declared in an instance of
100 -- System.Addess_To_Access_Conversions.
102 procedure Expand_Source_Info
(N
: Node_Id
; Nam
: Name_Id
);
103 -- Rewrite the node by the appropriate string or positive constant.
104 -- Nam can be one of the following:
105 -- Name_File - expand string that is the name of source file
106 -- Name_Line - expand integer line number
107 -- Name_Source_Location - expand string of form file:line
108 -- Name_Enclosing_Entity - expand string with name of enclosing entity
110 -----------------------------------------
111 -- Expand_Dispatching_Constructor_Call --
112 -----------------------------------------
114 -- Transform a call to an instantiation of Generic_Dispatching_Constructor
117 -- GDC_Instance (The_Tag, Parameters'Access)
119 -- to a class-wide conversion of a dispatching call to the actual
120 -- associated with the formal subprogram Construct, designating The_Tag
121 -- as the controlling tag of the call:
123 -- T'Class (Construct'Actual (Params)) -- Controlling tag is The_Tag
125 -- which will eventually be expanded to the following:
127 -- T'Class (The_Tag.all (Construct'Actual'Index).all (Params))
129 -- A class-wide membership test is also generated, preceding the call, to
130 -- ensure that the controlling tag denotes a type in T'Class.
132 procedure Expand_Dispatching_Constructor_Call
(N
: Node_Id
) is
133 Loc
: constant Source_Ptr
:= Sloc
(N
);
134 Tag_Arg
: constant Node_Id
:= First_Actual
(N
);
135 Param_Arg
: constant Node_Id
:= Next_Actual
(Tag_Arg
);
136 Subp_Decl
: constant Node_Id
:= Parent
(Parent
(Entity
(Name
(N
))));
137 Inst_Pkg
: constant Node_Id
:= Parent
(Subp_Decl
);
138 Act_Rename
: Node_Id
;
139 Act_Constr
: Entity_Id
;
140 Iface_Tag
: Node_Id
:= Empty
;
141 Cnstr_Call
: Node_Id
;
142 Result_Typ
: Entity_Id
;
145 -- The subprogram is the third actual in the instantiation, and is
146 -- retrieved from the corresponding renaming declaration. However,
147 -- freeze nodes may appear before, so we retrieve the declaration
148 -- with an explicit loop.
150 Act_Rename
:= First
(Visible_Declarations
(Inst_Pkg
));
151 while Nkind
(Act_Rename
) /= N_Subprogram_Renaming_Declaration
loop
155 Act_Constr
:= Entity
(Name
(Act_Rename
));
156 Result_Typ
:= Class_Wide_Type
(Etype
(Act_Constr
));
158 -- Ada 2005 (AI-251): If the result is an interface type, the function
159 -- returns a class-wide interface type (otherwise the resulting object
160 -- would be abstract!)
162 if Is_Interface
(Etype
(Act_Constr
)) then
163 Set_Etype
(Act_Constr
, Result_Typ
);
165 -- If the result type is not parent of Tag_Arg then we need to
166 -- locate the tag of the secondary dispatch table.
168 if not Is_Parent
(Etype
(Result_Typ
), Etype
(Tag_Arg
)) then
169 pragma Assert
(not Is_Interface
(Etype
(Tag_Arg
)));
172 Make_Object_Declaration
(Loc
,
173 Defining_Identifier
=>
174 Make_Defining_Identifier
(Loc
, New_Internal_Name
('V')),
176 New_Reference_To
(RTE
(RE_Tag
), Loc
),
178 Make_Function_Call
(Loc
,
179 Name
=> New_Reference_To
(RTE
(RE_Secondary_Tag
), Loc
),
180 Parameter_Associations
=> New_List
(
181 Relocate_Node
(Tag_Arg
),
183 (Node
(First_Elmt
(Access_Disp_Table
184 (Etype
(Etype
(Act_Constr
))))),
186 Insert_Action
(N
, Iface_Tag
);
190 -- Create the call to the actual Constructor function
193 Make_Function_Call
(Loc
,
194 Name
=> New_Occurrence_Of
(Act_Constr
, Loc
),
195 Parameter_Associations
=> New_List
(Relocate_Node
(Param_Arg
)));
197 -- Establish its controlling tag from the tag passed to the instance
198 -- The tag may be given by a function call, in which case a temporary
199 -- should be generated now, to prevent out-of-order insertions during
200 -- the expansion of that call when stack-checking is enabled.
202 if Present
(Iface_Tag
) then
203 Set_Controlling_Argument
(Cnstr_Call
,
204 New_Occurrence_Of
(Defining_Identifier
(Iface_Tag
), Loc
));
206 Remove_Side_Effects
(Tag_Arg
);
207 Set_Controlling_Argument
(Cnstr_Call
,
208 Relocate_Node
(Tag_Arg
));
211 -- Rewrite and analyze the call to the instance as a class-wide
212 -- conversion of the call to the actual constructor.
214 Rewrite
(N
, Convert_To
(Result_Typ
, Cnstr_Call
));
215 Analyze_And_Resolve
(N
, Etype
(Act_Constr
));
217 -- Do not generate a run-time check on the built object if tag
218 -- checks are suppressed for the result type or VM_Target /= No_VM
220 if Tag_Checks_Suppressed
(Etype
(Result_Typ
))
221 or else VM_Target
/= No_VM
225 -- Generate a class-wide membership test to ensure that the call's tag
226 -- argument denotes a type within the class. We must keep separate the
227 -- case in which the Result_Type of the constructor function is a tagged
228 -- type from the case in which it is an abstract interface because the
229 -- run-time subprogram required to check these cases differ (and have
230 -- one difference in their parameters profile).
232 -- Call CW_Membership if the Result_Type is a tagged type to look for
233 -- the tag in the table of ancestor tags.
235 elsif not Is_Interface
(Result_Typ
) then
237 Make_Implicit_If_Statement
(N
,
240 Build_CW_Membership
(Loc
,
241 Obj_Tag_Node
=> Duplicate_Subexpr
(Tag_Arg
),
244 Node
(First_Elmt
(Access_Disp_Table
(
245 Root_Type
(Result_Typ
)))), Loc
))),
247 New_List
(Make_Raise_Statement
(Loc
,
248 New_Occurrence_Of
(RTE
(RE_Tag_Error
), Loc
)))));
250 -- Call IW_Membership test if the Result_Type is an abstract interface
251 -- to look for the tag in the table of interface tags.
255 Make_Implicit_If_Statement
(N
,
258 Make_Function_Call
(Loc
,
259 Name
=> New_Occurrence_Of
(RTE
(RE_IW_Membership
), Loc
),
260 Parameter_Associations
=> New_List
(
261 Make_Attribute_Reference
(Loc
,
262 Prefix
=> Duplicate_Subexpr
(Tag_Arg
),
263 Attribute_Name
=> Name_Address
),
266 Node
(First_Elmt
(Access_Disp_Table
(
267 Root_Type
(Result_Typ
)))), Loc
)))),
270 Make_Raise_Statement
(Loc
,
271 Name
=> New_Occurrence_Of
(RTE
(RE_Tag_Error
), Loc
)))));
273 end Expand_Dispatching_Constructor_Call
;
275 ---------------------------
276 -- Expand_Exception_Call --
277 ---------------------------
279 -- If the function call is not within an exception handler, then the call
280 -- is replaced by a null string. Otherwise the appropriate routine in
281 -- Ada.Exceptions is called passing the choice parameter specification
282 -- from the enclosing handler. If the enclosing handler lacks a choice
283 -- parameter, then one is supplied.
285 procedure Expand_Exception_Call
(N
: Node_Id
; Ent
: RE_Id
) is
286 Loc
: constant Source_Ptr
:= Sloc
(N
);
291 -- Climb up parents to see if we are in exception handler
295 -- Case of not in exception handler, replace by null string
299 Make_String_Literal
(Loc
,
303 -- Case of in exception handler
305 elsif Nkind
(P
) = N_Exception_Handler
then
307 -- Handler cannot be used for a local raise, and furthermore, this
308 -- is a violation of the No_Exception_Propagation restriction.
310 Set_Local_Raise_Not_OK
(P
);
311 Check_Restriction
(No_Exception_Propagation
, N
);
313 -- If no choice parameter present, then put one there. Note that
314 -- we do not need to put it on the entity chain, since no one will
315 -- be referencing it by normal visibility methods.
317 if No
(Choice_Parameter
(P
)) then
318 E
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('E'));
319 Set_Choice_Parameter
(P
, E
);
320 Set_Ekind
(E
, E_Variable
);
321 Set_Etype
(E
, RTE
(RE_Exception_Occurrence
));
322 Set_Scope
(E
, Current_Scope
);
326 Make_Function_Call
(Loc
,
327 Name
=> New_Occurrence_Of
(RTE
(Ent
), Loc
),
328 Parameter_Associations
=> New_List
(
329 New_Occurrence_Of
(Choice_Parameter
(P
), Loc
))));
339 Analyze_And_Resolve
(N
, Standard_String
);
340 end Expand_Exception_Call
;
342 ------------------------
343 -- Expand_Import_Call --
344 ------------------------
346 -- The function call must have a static string as its argument. We create
347 -- a dummy variable which uses this string as the external name in an
348 -- Import pragma. The result is then obtained as the address of this
349 -- dummy variable, converted to the appropriate target type.
351 procedure Expand_Import_Call
(N
: Node_Id
) is
352 Loc
: constant Source_Ptr
:= Sloc
(N
);
353 Ent
: constant Entity_Id
:= Entity
(Name
(N
));
354 Str
: constant Node_Id
:= First_Actual
(N
);
358 Dum
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('D'));
360 Insert_Actions
(N
, New_List
(
361 Make_Object_Declaration
(Loc
,
362 Defining_Identifier
=> Dum
,
364 New_Occurrence_Of
(Standard_Character
, Loc
)),
367 Chars
=> Name_Import
,
368 Pragma_Argument_Associations
=> New_List
(
369 Make_Pragma_Argument_Association
(Loc
,
370 Expression
=> Make_Identifier
(Loc
, Name_Ada
)),
372 Make_Pragma_Argument_Association
(Loc
,
373 Expression
=> Make_Identifier
(Loc
, Chars
(Dum
))),
375 Make_Pragma_Argument_Association
(Loc
,
376 Chars
=> Name_Link_Name
,
377 Expression
=> Relocate_Node
(Str
))))));
380 Unchecked_Convert_To
(Etype
(Ent
),
381 Make_Attribute_Reference
(Loc
,
382 Prefix
=> Make_Identifier
(Loc
, Chars
(Dum
)),
383 Attribute_Name
=> Name_Address
)));
385 Analyze_And_Resolve
(N
, Etype
(Ent
));
386 end Expand_Import_Call
;
388 ---------------------------
389 -- Expand_Intrinsic_Call --
390 ---------------------------
392 procedure Expand_Intrinsic_Call
(N
: Node_Id
; E
: Entity_Id
) is
396 -- If the intrinsic subprogram is generic, gets its original name
398 if Present
(Parent
(E
))
399 and then Present
(Generic_Parent
(Parent
(E
)))
401 Nam
:= Chars
(Generic_Parent
(Parent
(E
)));
406 if Nam
= Name_Asm
then
409 elsif Nam
= Name_Divide
then
410 Expand_Decimal_Divide_Call
(N
);
412 elsif Nam
= Name_Exception_Information
then
413 Expand_Exception_Call
(N
, RE_Exception_Information
);
415 elsif Nam
= Name_Exception_Message
then
416 Expand_Exception_Call
(N
, RE_Exception_Message
);
418 elsif Nam
= Name_Exception_Name
then
419 Expand_Exception_Call
(N
, RE_Exception_Name_Simple
);
421 elsif Nam
= Name_Generic_Dispatching_Constructor
then
422 Expand_Dispatching_Constructor_Call
(N
);
424 elsif Nam
= Name_Import_Address
426 Nam
= Name_Import_Largest_Value
428 Nam
= Name_Import_Value
430 Expand_Import_Call
(N
);
432 elsif Nam
= Name_Is_Negative
then
433 Expand_Is_Negative
(N
);
435 elsif Nam
= Name_Rotate_Left
then
436 Expand_Shift
(N
, E
, N_Op_Rotate_Left
);
438 elsif Nam
= Name_Rotate_Right
then
439 Expand_Shift
(N
, E
, N_Op_Rotate_Right
);
441 elsif Nam
= Name_Shift_Left
then
442 Expand_Shift
(N
, E
, N_Op_Shift_Left
);
444 elsif Nam
= Name_Shift_Right
then
445 Expand_Shift
(N
, E
, N_Op_Shift_Right
);
447 elsif Nam
= Name_Shift_Right_Arithmetic
then
448 Expand_Shift
(N
, E
, N_Op_Shift_Right_Arithmetic
);
450 elsif Nam
= Name_Unchecked_Conversion
then
451 Expand_Unc_Conversion
(N
, E
);
453 elsif Nam
= Name_Unchecked_Deallocation
then
454 Expand_Unc_Deallocation
(N
);
456 elsif Nam
= Name_To_Address
then
457 Expand_To_Address
(N
);
459 elsif Nam
= Name_To_Pointer
then
460 Expand_To_Pointer
(N
);
462 elsif Nam
= Name_File
463 or else Nam
= Name_Line
464 or else Nam
= Name_Source_Location
465 or else Nam
= Name_Enclosing_Entity
467 Expand_Source_Info
(N
, Nam
);
469 -- If we have a renaming, expand the call to the original operation,
470 -- which must itself be intrinsic, since renaming requires matching
471 -- conventions and this has already been checked.
473 elsif Present
(Alias
(E
)) then
474 Expand_Intrinsic_Call
(N
, Alias
(E
));
476 -- The only other case is where an external name was specified,
477 -- since this is the only way that an otherwise unrecognized
478 -- name could escape the checking in Sem_Prag. Nothing needs
479 -- to be done in such a case, since we pass such a call to the
480 -- back end unchanged.
485 end Expand_Intrinsic_Call
;
487 ------------------------
488 -- Expand_Is_Negative --
489 ------------------------
491 procedure Expand_Is_Negative
(N
: Node_Id
) is
492 Loc
: constant Source_Ptr
:= Sloc
(N
);
493 Opnd
: constant Node_Id
:= Relocate_Node
(First_Actual
(N
));
497 -- We replace the function call by the following expression
499 -- if Opnd < 0.0 then
502 -- if Opnd > 0.0 then
505 -- Float_Unsigned!(Float (Opnd)) /= 0
510 Make_Conditional_Expression
(Loc
,
511 Expressions
=> New_List
(
513 Left_Opnd
=> Duplicate_Subexpr
(Opnd
),
514 Right_Opnd
=> Make_Real_Literal
(Loc
, Ureal_0
)),
516 New_Occurrence_Of
(Standard_True
, Loc
),
518 Make_Conditional_Expression
(Loc
,
519 Expressions
=> New_List
(
521 Left_Opnd
=> Duplicate_Subexpr_No_Checks
(Opnd
),
522 Right_Opnd
=> Make_Real_Literal
(Loc
, Ureal_0
)),
524 New_Occurrence_Of
(Standard_False
, Loc
),
529 (RTE
(RE_Float_Unsigned
),
532 Duplicate_Subexpr_No_Checks
(Opnd
))),
534 Make_Integer_Literal
(Loc
, 0)))))));
536 Analyze_And_Resolve
(N
, Standard_Boolean
);
537 end Expand_Is_Negative
;
543 -- This procedure is used to convert a call to a shift function to the
544 -- corresponding operator node. This conversion is not done by the usual
545 -- circuit for converting calls to operator functions (e.g. "+"(1,2)) to
546 -- operator nodes, because shifts are not predefined operators.
548 -- As a result, whenever a shift is used in the source program, it will
549 -- remain as a call until converted by this routine to the operator node
550 -- form which Gigi is expecting to see.
552 -- Note: it is possible for the expander to generate shift operator nodes
553 -- directly, which will be analyzed in the normal manner by calling Analyze
554 -- and Resolve. Such shift operator nodes will not be seen by Expand_Shift.
556 procedure Expand_Shift
(N
: Node_Id
; E
: Entity_Id
; K
: Node_Kind
) is
557 Loc
: constant Source_Ptr
:= Sloc
(N
);
558 Typ
: constant Entity_Id
:= Etype
(N
);
559 Left
: constant Node_Id
:= First_Actual
(N
);
560 Right
: constant Node_Id
:= Next_Actual
(Left
);
561 Ltyp
: constant Node_Id
:= Etype
(Left
);
562 Rtyp
: constant Node_Id
:= Etype
(Right
);
566 Snode
:= New_Node
(K
, Loc
);
567 Set_Left_Opnd
(Snode
, Relocate_Node
(Left
));
568 Set_Right_Opnd
(Snode
, Relocate_Node
(Right
));
569 Set_Chars
(Snode
, Chars
(E
));
570 Set_Etype
(Snode
, Base_Type
(Typ
));
571 Set_Entity
(Snode
, E
);
573 if Compile_Time_Known_Value
(Type_High_Bound
(Rtyp
))
574 and then Expr_Value
(Type_High_Bound
(Rtyp
)) < Esize
(Ltyp
)
576 Set_Shift_Count_OK
(Snode
, True);
579 -- Do the rewrite. Note that we don't call Analyze and Resolve on
580 -- this node, because it already got analyzed and resolved when
581 -- it was a function call!
587 ------------------------
588 -- Expand_Source_Info --
589 ------------------------
591 procedure Expand_Source_Info
(N
: Node_Id
; Nam
: Name_Id
) is
592 Loc
: constant Source_Ptr
:= Sloc
(N
);
595 procedure Write_Entity_Name
(E
: Entity_Id
);
596 -- Recursive procedure to construct string for qualified name of
597 -- enclosing program unit. The qualification stops at an enclosing
598 -- scope has no source name (block or loop). If entity is a subprogram
599 -- instance, skip enclosing wrapper package.
601 -----------------------
602 -- Write_Entity_Name --
603 -----------------------
605 procedure Write_Entity_Name
(E
: Entity_Id
) is
607 TDef
: constant Source_Buffer_Ptr
:=
608 Source_Text
(Get_Source_File_Index
(Sloc
(E
)));
611 -- Nothing to do if at outer level
613 if Scope
(E
) = Standard_Standard
then
616 -- If scope comes from source, write its name
618 elsif Comes_From_Source
(Scope
(E
)) then
619 Write_Entity_Name
(Scope
(E
));
620 Add_Char_To_Name_Buffer
('.');
622 -- If in wrapper package skip past it
624 elsif Is_Wrapper_Package
(Scope
(E
)) then
625 Write_Entity_Name
(Scope
(Scope
(E
)));
626 Add_Char_To_Name_Buffer
('.');
628 -- Otherwise nothing to output (happens in unnamed block statements)
634 -- Loop to output the name
636 -- is this right wrt wide char encodings ??? (no!)
639 while TDef
(SDef
) in '0' .. '9'
640 or else TDef
(SDef
) >= 'A'
641 or else TDef
(SDef
) = ASCII
.ESC
643 Add_Char_To_Name_Buffer
(TDef
(SDef
));
646 end Write_Entity_Name
;
648 -- Start of processing for Expand_Source_Info
653 if Nam
= Name_Line
then
655 Make_Integer_Literal
(Loc
,
656 Intval
=> UI_From_Int
(Int
(Get_Logical_Line_Number
(Loc
)))));
657 Analyze_And_Resolve
(N
, Standard_Positive
);
664 Get_Decoded_Name_String
665 (Reference_Name
(Get_Source_File_Index
(Loc
)));
667 when Name_Source_Location
=>
668 Build_Location_String
(Loc
);
670 when Name_Enclosing_Entity
=>
673 Ent
:= Current_Scope
;
675 -- Skip enclosing blocks to reach enclosing unit
677 while Present
(Ent
) loop
678 exit when Ekind
(Ent
) /= E_Block
679 and then Ekind
(Ent
) /= E_Loop
;
683 -- Ent now points to the relevant defining entity
686 Write_Entity_Name
(Ent
);
693 Make_String_Literal
(Loc
, Strval
=> String_From_Name_Buffer
));
694 Analyze_And_Resolve
(N
, Standard_String
);
697 Set_Is_Static_Expression
(N
);
698 end Expand_Source_Info
;
700 ---------------------------
701 -- Expand_Unc_Conversion --
702 ---------------------------
704 procedure Expand_Unc_Conversion
(N
: Node_Id
; E
: Entity_Id
) is
705 Func
: constant Entity_Id
:= Entity
(Name
(N
));
711 -- Rewrite as unchecked conversion node. Note that we must convert
712 -- the operand to the formal type of the input parameter of the
713 -- function, so that the resulting N_Unchecked_Type_Conversion
714 -- call indicates the correct types for Gigi.
716 -- Right now, we only do this if a scalar type is involved. It is
717 -- not clear if it is needed in other cases. If we do attempt to
718 -- do the conversion unconditionally, it crashes 3411-018. To be
719 -- investigated further ???
721 Conv
:= Relocate_Node
(First_Actual
(N
));
722 Ftyp
:= Etype
(First_Formal
(Func
));
724 if Is_Scalar_Type
(Ftyp
) then
725 Conv
:= Convert_To
(Ftyp
, Conv
);
726 Set_Parent
(Conv
, N
);
727 Analyze_And_Resolve
(Conv
);
730 -- The instantiation of Unchecked_Conversion creates a wrapper package,
731 -- and the target type is declared as a subtype of the actual. Recover
732 -- the actual, which is the subtype indic. in the subtype declaration
733 -- for the target type. This is semantically correct, and avoids
734 -- anomalies with access subtypes. For entities, leave type as is.
736 -- We do the analysis here, because we do not want the compiler
737 -- to try to optimize or otherwise reorganize the unchecked
742 if Is_Entity_Name
(Conv
) then
745 elsif Nkind
(Parent
(Ttyp
)) = N_Subtype_Declaration
then
746 Ttyp
:= Entity
(Subtype_Indication
(Parent
(Etype
(E
))));
748 elsif Is_Itype
(Ttyp
) then
750 Entity
(Subtype_Indication
(Associated_Node_For_Itype
(Ttyp
)));
755 Rewrite
(N
, Unchecked_Convert_To
(Ttyp
, Conv
));
759 if Nkind
(N
) = N_Unchecked_Type_Conversion
then
760 Expand_N_Unchecked_Type_Conversion
(N
);
762 end Expand_Unc_Conversion
;
764 -----------------------------
765 -- Expand_Unc_Deallocation --
766 -----------------------------
768 -- Generate the following Code :
770 -- if Arg /= null then
771 -- <Finalize_Call> (.., T'Class(Arg.all), ..); -- for controlled types
776 -- For a task, we also generate a call to Free_Task to ensure that the
777 -- task itself is freed if it is terminated, ditto for a simple protected
778 -- object, with a call to Finalize_Protection. For composite types that
779 -- have tasks or simple protected objects as components, we traverse the
780 -- structures to find and terminate those components.
782 procedure Expand_Unc_Deallocation
(N
: Node_Id
) is
783 Loc
: constant Source_Ptr
:= Sloc
(N
);
784 Arg
: constant Node_Id
:= First_Actual
(N
);
785 Typ
: constant Entity_Id
:= Etype
(Arg
);
786 Stmts
: constant List_Id
:= New_List
;
787 Rtyp
: constant Entity_Id
:= Underlying_Type
(Root_Type
(Typ
));
788 Pool
: constant Entity_Id
:= Associated_Storage_Pool
(Rtyp
);
790 Desig_T
: constant Entity_Id
:= Designated_Type
(Typ
);
798 Arg_Known_Non_Null
: constant Boolean := Known_Non_Null
(N
);
799 -- This captures whether we know the argument to be non-null so that
800 -- we can avoid the test. The reason that we need to capture this is
801 -- that we analyze some generated statements before properly attaching
802 -- them to the tree, and that can disturb current value settings.
805 if No_Pool_Assigned
(Rtyp
) then
806 Error_Msg_N
("?deallocation from empty storage pool!", N
);
809 -- Nothing to do if we know the argument is null
811 if Known_Null
(N
) then
815 -- Processing for pointer to controlled type
817 if Controlled_Type
(Desig_T
) then
819 Make_Explicit_Dereference
(Loc
,
820 Prefix
=> Duplicate_Subexpr_No_Checks
(Arg
));
822 -- If the type is tagged, then we must force dispatching on the
823 -- finalization call because the designated type may not be the
824 -- actual type of the object.
826 if Is_Tagged_Type
(Desig_T
)
827 and then not Is_Class_Wide_Type
(Desig_T
)
829 Deref
:= Unchecked_Convert_To
(Class_Wide_Type
(Desig_T
), Deref
);
831 elsif not Is_Tagged_Type
(Desig_T
) then
833 -- Set type of result, to force a conversion when needed (see
834 -- exp_ch7, Convert_View), given that Deep_Finalize may be
835 -- inherited from the parent type, and we need the type of the
836 -- expression to see whether the conversion is in fact needed.
838 Set_Etype
(Deref
, Desig_T
);
845 With_Detach
=> New_Reference_To
(Standard_True
, Loc
));
847 if Abort_Allowed
then
848 Prepend_To
(Free_Cod
,
849 Build_Runtime_Call
(Loc
, RE_Abort_Defer
));
852 Make_Block_Statement
(Loc
, Handled_Statement_Sequence
=>
853 Make_Handled_Sequence_Of_Statements
(Loc
,
854 Statements
=> Free_Cod
,
856 New_Occurrence_Of
(RTE
(RE_Abort_Undefer_Direct
), Loc
)));
858 -- We now expand the exception (at end) handler. We set a
859 -- temporary parent pointer since we have not attached Blk
864 Expand_At_End_Handler
865 (Handled_Statement_Sequence
(Blk
), Entity
(Identifier
(Blk
)));
868 -- We kill saved current values, since analyzing statements not
869 -- properly attached to the tree can set wrong current values.
874 Append_List_To
(Stmts
, Free_Cod
);
878 -- For a task type, call Free_Task before freeing the ATCB
880 if Is_Task_Type
(Desig_T
) then
882 Stat
: Node_Id
:= Prev
(N
);
887 -- An Abort followed by a Free will not do what the user
888 -- expects, because the abort is not immediate. This is
889 -- worth a friendly warning.
892 and then not Comes_From_Source
(Original_Node
(Stat
))
898 and then Nkind
(Original_Node
(Stat
)) = N_Abort_Statement
900 Stat
:= Original_Node
(Stat
);
901 Nam1
:= First
(Names
(Stat
));
902 Nam2
:= Original_Node
(First
(Parameter_Associations
(N
)));
904 if Nkind
(Nam1
) = N_Explicit_Dereference
905 and then Is_Entity_Name
(Prefix
(Nam1
))
906 and then Is_Entity_Name
(Nam2
)
907 and then Entity
(Prefix
(Nam1
)) = Entity
(Nam2
)
909 Error_Msg_N
("abort may take time to complete?", N
);
910 Error_Msg_N
("\deallocation might have no effect?", N
);
911 Error_Msg_N
("\safer to wait for termination.?", N
);
917 (Stmts
, Cleanup_Task
(N
, Duplicate_Subexpr_No_Checks
(Arg
)));
919 -- For composite types that contain tasks, recurse over the structure
920 -- to build the selectors for the task subcomponents.
922 elsif Has_Task
(Desig_T
) then
923 if Is_Record_Type
(Desig_T
) then
924 Append_List_To
(Stmts
, Cleanup_Record
(N
, Arg
, Desig_T
));
926 elsif Is_Array_Type
(Desig_T
) then
927 Append_List_To
(Stmts
, Cleanup_Array
(N
, Arg
, Desig_T
));
931 -- Same for simple protected types. Eventually call Finalize_Protection
932 -- before freeing the PO for each protected component.
934 if Is_Simple_Protected_Type
(Desig_T
) then
936 Cleanup_Protected_Object
(N
, Duplicate_Subexpr_No_Checks
(Arg
)));
938 elsif Has_Simple_Protected_Object
(Desig_T
) then
939 if Is_Record_Type
(Desig_T
) then
940 Append_List_To
(Stmts
, Cleanup_Record
(N
, Arg
, Desig_T
));
941 elsif Is_Array_Type
(Desig_T
) then
942 Append_List_To
(Stmts
, Cleanup_Array
(N
, Arg
, Desig_T
));
946 -- Normal processing for non-controlled types
948 Free_Arg
:= Duplicate_Subexpr_No_Checks
(Arg
);
949 Free_Node
:= Make_Free_Statement
(Loc
, Empty
);
950 Append_To
(Stmts
, Free_Node
);
951 Set_Storage_Pool
(Free_Node
, Pool
);
953 -- Deal with storage pool
955 if Present
(Pool
) then
957 -- Freeing the secondary stack is meaningless
959 if Is_RTE
(Pool
, RE_SS_Pool
) then
962 elsif Is_Class_Wide_Type
(Etype
(Pool
)) then
964 -- Case of a class-wide pool type: make a dispatching call
965 -- to Deallocate through the class-wide Deallocate_Any.
967 Set_Procedure_To_Call
(Free_Node
,
968 RTE
(RE_Deallocate_Any
));
971 -- Case of a specific pool type: make a statically bound call
973 Set_Procedure_To_Call
(Free_Node
,
974 Find_Prim_Op
(Etype
(Pool
), Name_Deallocate
));
978 if Present
(Procedure_To_Call
(Free_Node
)) then
980 -- For all cases of a Deallocate call, the back-end needs to be
981 -- able to compute the size of the object being freed. This may
982 -- require some adjustments for objects of dynamic size.
984 -- If the type is class wide, we generate an implicit type with the
985 -- right dynamic size, so that the deallocate call gets the right
986 -- size parameter computed by GIGI. Same for an access to
987 -- unconstrained packed array.
989 if Is_Class_Wide_Type
(Desig_T
)
991 (Is_Array_Type
(Desig_T
)
992 and then not Is_Constrained
(Desig_T
)
993 and then Is_Packed
(Desig_T
))
996 Deref
: constant Node_Id
:=
997 Make_Explicit_Dereference
(Loc
,
998 Duplicate_Subexpr_No_Checks
(Arg
));
1003 Set_Etype
(Deref
, Typ
);
1004 Set_Parent
(Deref
, Free_Node
);
1005 D_Subtyp
:= Make_Subtype_From_Expr
(Deref
, Desig_T
);
1007 if Nkind
(D_Subtyp
) in N_Has_Entity
then
1008 D_Type
:= Entity
(D_Subtyp
);
1011 D_Type
:= Make_Defining_Identifier
(Loc
,
1012 New_Internal_Name
('A'));
1014 Make_Subtype_Declaration
(Loc
,
1015 Defining_Identifier
=> D_Type
,
1016 Subtype_Indication
=> D_Subtyp
));
1017 Freeze_Itype
(D_Type
, N
);
1021 Set_Actual_Designated_Subtype
(Free_Node
, D_Type
);
1027 -- Ada 2005 (AI-251): In case of abstract interface type we must
1028 -- displace the pointer to reference the base of the object to
1029 -- deallocate its memory, unless we're targetting a VM, in which case
1030 -- no special processing is required.
1033 -- free (Base_Address (Obj_Ptr))
1035 if Is_Interface
(Directly_Designated_Type
(Typ
))
1036 and then VM_Target
= No_VM
1038 Set_Expression
(Free_Node
,
1039 Unchecked_Convert_To
(Typ
,
1040 Make_Function_Call
(Loc
,
1041 Name
=> New_Reference_To
(RTE
(RE_Base_Address
), Loc
),
1042 Parameter_Associations
=> New_List
(
1043 Unchecked_Convert_To
(RTE
(RE_Address
), Free_Arg
)))));
1049 Set_Expression
(Free_Node
, Free_Arg
);
1052 -- Only remaining step is to set result to null, or generate a
1053 -- raise of constraint error if the target object is "not null".
1055 if Can_Never_Be_Null
(Etype
(Arg
)) then
1057 Make_Raise_Constraint_Error
(Loc
,
1058 Reason
=> CE_Access_Check_Failed
));
1062 Lhs
: constant Node_Id
:= Duplicate_Subexpr_No_Checks
(Arg
);
1064 Set_Assignment_OK
(Lhs
);
1066 Make_Assignment_Statement
(Loc
,
1068 Expression
=> Make_Null
(Loc
)));
1072 -- If we know the argument is non-null, then make a block statement
1073 -- that contains the required statements, no need for a test.
1075 if Arg_Known_Non_Null
then
1077 Make_Block_Statement
(Loc
,
1078 Handled_Statement_Sequence
=>
1079 Make_Handled_Sequence_Of_Statements
(Loc
,
1080 Statements
=> Stmts
));
1082 -- If the argument may be null, wrap the statements inside an IF that
1083 -- does an explicit test to exclude the null case.
1087 Make_Implicit_If_Statement
(N
,
1090 Left_Opnd
=> Duplicate_Subexpr
(Arg
),
1091 Right_Opnd
=> Make_Null
(Loc
)),
1092 Then_Statements
=> Stmts
);
1097 Rewrite
(N
, Gen_Code
);
1099 end Expand_Unc_Deallocation
;
1101 -----------------------
1102 -- Expand_To_Address --
1103 -----------------------
1105 procedure Expand_To_Address
(N
: Node_Id
) is
1106 Loc
: constant Source_Ptr
:= Sloc
(N
);
1107 Arg
: constant Node_Id
:= First_Actual
(N
);
1111 Remove_Side_Effects
(Arg
);
1113 Obj
:= Make_Explicit_Dereference
(Loc
, Relocate_Node
(Arg
));
1116 Make_Conditional_Expression
(Loc
,
1117 Expressions
=> New_List
(
1119 Left_Opnd
=> New_Copy_Tree
(Arg
),
1120 Right_Opnd
=> Make_Null
(Loc
)),
1121 New_Occurrence_Of
(RTE
(RE_Null_Address
), Loc
),
1122 Make_Attribute_Reference
(Loc
,
1124 Attribute_Name
=> Name_Address
))));
1126 Analyze_And_Resolve
(N
, RTE
(RE_Address
));
1127 end Expand_To_Address
;
1129 -----------------------
1130 -- Expand_To_Pointer --
1131 -----------------------
1133 procedure Expand_To_Pointer
(N
: Node_Id
) is
1134 Arg
: constant Node_Id
:= First_Actual
(N
);
1137 Rewrite
(N
, Unchecked_Convert_To
(Etype
(N
), Arg
));
1139 end Expand_To_Pointer
;