1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2017, 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 Contracts
; use Contracts
;
29 with Debug
; use Debug
;
30 with Einfo
; use Einfo
;
31 with Errout
; use Errout
;
32 with Elists
; use Elists
;
33 with Exp_Aggr
; use Exp_Aggr
;
34 with Exp_Atag
; use Exp_Atag
;
35 with Exp_Ch2
; use Exp_Ch2
;
36 with Exp_Ch3
; use Exp_Ch3
;
37 with Exp_Ch7
; use Exp_Ch7
;
38 with Exp_Ch9
; use Exp_Ch9
;
39 with Exp_Dbug
; use Exp_Dbug
;
40 with Exp_Disp
; use Exp_Disp
;
41 with Exp_Dist
; use Exp_Dist
;
42 with Exp_Intr
; use Exp_Intr
;
43 with Exp_Pakd
; use Exp_Pakd
;
44 with Exp_Tss
; use Exp_Tss
;
45 with Exp_Util
; use Exp_Util
;
46 with Freeze
; use Freeze
;
47 with Inline
; use Inline
;
49 with Namet
; use Namet
;
50 with Nlists
; use Nlists
;
51 with Nmake
; use Nmake
;
53 with Restrict
; use Restrict
;
54 with Rident
; use Rident
;
55 with Rtsfind
; use Rtsfind
;
57 with Sem_Aux
; use Sem_Aux
;
58 with Sem_Ch6
; use Sem_Ch6
;
59 with Sem_Ch8
; use Sem_Ch8
;
60 with Sem_Ch12
; use Sem_Ch12
;
61 with Sem_Ch13
; use Sem_Ch13
;
62 with Sem_Dim
; use Sem_Dim
;
63 with Sem_Disp
; use Sem_Disp
;
64 with Sem_Dist
; use Sem_Dist
;
65 with Sem_Eval
; use Sem_Eval
;
66 with Sem_Mech
; use Sem_Mech
;
67 with Sem_Res
; use Sem_Res
;
68 with Sem_SCIL
; use Sem_SCIL
;
69 with Sem_Util
; use Sem_Util
;
70 with Sinfo
; use Sinfo
;
71 with Snames
; use Snames
;
72 with Stand
; use Stand
;
73 with Targparm
; use Targparm
;
74 with Tbuild
; use Tbuild
;
75 with Uintp
; use Uintp
;
76 with Validsw
; use Validsw
;
78 package body Exp_Ch6
is
80 -----------------------
81 -- Local Subprograms --
82 -----------------------
84 procedure Add_Access_Actual_To_Build_In_Place_Call
85 (Function_Call
: Node_Id
;
86 Function_Id
: Entity_Id
;
87 Return_Object
: Node_Id
;
88 Is_Access
: Boolean := False);
89 -- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
90 -- object name given by Return_Object and add the attribute to the end of
91 -- the actual parameter list associated with the build-in-place function
92 -- call denoted by Function_Call. However, if Is_Access is True, then
93 -- Return_Object is already an access expression, in which case it's passed
94 -- along directly to the build-in-place function. Finally, if Return_Object
95 -- is empty, then pass a null literal as the actual.
97 procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
98 (Function_Call
: Node_Id
;
99 Function_Id
: Entity_Id
;
100 Alloc_Form
: BIP_Allocation_Form
:= Unspecified
;
101 Alloc_Form_Exp
: Node_Id
:= Empty
;
102 Pool_Actual
: Node_Id
:= Make_Null
(No_Location
));
103 -- Ada 2005 (AI-318-02): Add the actuals needed for a build-in-place
104 -- function call that returns a caller-unknown-size result (BIP_Alloc_Form
105 -- and BIP_Storage_Pool). If Alloc_Form_Exp is present, then use it,
106 -- otherwise pass a literal corresponding to the Alloc_Form parameter
107 -- (which must not be Unspecified in that case). Pool_Actual is the
108 -- parameter to pass to BIP_Storage_Pool.
110 procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
111 (Func_Call
: Node_Id
;
113 Ptr_Typ
: Entity_Id
:= Empty
;
114 Master_Exp
: Node_Id
:= Empty
);
115 -- Ada 2005 (AI-318-02): If the result type of a build-in-place call needs
116 -- finalization actions, add an actual parameter which is a pointer to the
117 -- finalization master of the caller. If Master_Exp is not Empty, then that
118 -- will be passed as the actual. Otherwise, if Ptr_Typ is left Empty, this
119 -- will result in an automatic "null" value for the actual.
121 procedure Add_Task_Actuals_To_Build_In_Place_Call
122 (Function_Call
: Node_Id
;
123 Function_Id
: Entity_Id
;
124 Master_Actual
: Node_Id
;
125 Chain
: Node_Id
:= Empty
);
126 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
127 -- contains tasks, add two actual parameters: the master, and a pointer to
128 -- the caller's activation chain. Master_Actual is the actual parameter
129 -- expression to pass for the master. In most cases, this is the current
130 -- master (_master). The two exceptions are: If the function call is the
131 -- initialization expression for an allocator, we pass the master of the
132 -- access type. If the function call is the initialization expression for a
133 -- return object, we pass along the master passed in by the caller. In most
134 -- contexts, the activation chain to pass is the local one, which is
135 -- indicated by No (Chain). However, in an allocator, the caller passes in
136 -- the activation Chain. Note: Master_Actual can be Empty, but only if
137 -- there are no tasks.
139 procedure Check_Overriding_Operation
(Subp
: Entity_Id
);
140 -- Subp is a dispatching operation. Check whether it may override an
141 -- inherited private operation, in which case its DT entry is that of
142 -- the hidden operation, not the one it may have received earlier.
143 -- This must be done before emitting the code to set the corresponding
144 -- DT to the address of the subprogram. The actual placement of Subp in
145 -- the proper place in the list of primitive operations is done in
146 -- Declare_Inherited_Private_Subprograms, which also has to deal with
147 -- implicit operations. This duplication is unavoidable for now???
149 procedure Detect_Infinite_Recursion
(N
: Node_Id
; Spec
: Entity_Id
);
150 -- This procedure is called only if the subprogram body N, whose spec
151 -- has the given entity Spec, contains a parameterless recursive call.
152 -- It attempts to generate runtime code to detect if this a case of
153 -- infinite recursion.
155 -- The body is scanned to determine dependencies. If the only external
156 -- dependencies are on a small set of scalar variables, then the values
157 -- of these variables are captured on entry to the subprogram, and if
158 -- the values are not changed for the call, we know immediately that
159 -- we have an infinite recursion.
161 procedure Expand_Actuals
164 Post_Call
: out List_Id
);
165 -- Return a list of actions to take place after the call in Post_Call. The
166 -- call will later be rewritten as an Expression_With_Actions, with the
167 -- Post_Call actions inserted, and the call inside.
169 -- For each actual of an in-out or out parameter which is a numeric (view)
170 -- conversion of the form T (A), where A denotes a variable, we insert the
173 -- Temp : T[ := T (A)];
175 -- prior to the call. Then we replace the actual with a reference to Temp,
176 -- and append the assignment:
178 -- A := TypeA (Temp);
180 -- after the call. Here TypeA is the actual type of variable A. For out
181 -- parameters, the initial declaration has no expression. If A is not an
182 -- entity name, we generate instead:
184 -- Var : TypeA renames A;
185 -- Temp : T := Var; -- omitting expression for out parameter.
187 -- Var := TypeA (Temp);
189 -- For other in-out parameters, we emit the required constraint checks
190 -- before and/or after the call.
192 -- For all parameter modes, actuals that denote components and slices of
193 -- packed arrays are expanded into suitable temporaries.
195 -- For non-scalar objects that are possibly unaligned, add call by copy
196 -- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
198 -- For OUT and IN OUT parameters, add predicate checks after the call
199 -- based on the predicates of the actual type.
201 procedure Expand_Call_Helper
(N
: Node_Id
; Post_Call
: out List_Id
);
202 -- Does the main work of Expand_Call. Post_Call is as for Expand_Actuals.
204 procedure Expand_Ctrl_Function_Call
(N
: Node_Id
);
205 -- N is a function call which returns a controlled object. Transform the
206 -- call into a temporary which retrieves the returned object from the
207 -- secondary stack using 'reference.
209 procedure Expand_Non_Function_Return
(N
: Node_Id
);
210 -- Expand a simple return statement found in a procedure body, entry body,
211 -- accept statement, or an extended return statement. Note that all non-
212 -- function returns are simple return statements.
214 function Expand_Protected_Object_Reference
216 Scop
: Entity_Id
) return Node_Id
;
218 procedure Expand_Protected_Subprogram_Call
222 -- A call to a protected subprogram within the protected object may appear
223 -- as a regular call. The list of actuals must be expanded to contain a
224 -- reference to the object itself, and the call becomes a call to the
225 -- corresponding protected subprogram.
227 procedure Expand_Simple_Function_Return
(N
: Node_Id
);
228 -- Expand simple return from function. In the case where we are returning
229 -- from a function body this is called by Expand_N_Simple_Return_Statement.
231 function Has_Unconstrained_Access_Discriminants
232 (Subtyp
: Entity_Id
) return Boolean;
233 -- Returns True if the given subtype is unconstrained and has one or more
234 -- access discriminants.
236 procedure Insert_Post_Call_Actions
(N
: Node_Id
; Post_Call
: List_Id
);
237 -- Insert the Post_Call list previously produced by routine Expand_Actuals
238 -- or Expand_Call_Helper into the tree.
240 procedure Rewrite_Function_Call_For_C
(N
: Node_Id
);
241 -- When generating C code, replace a call to a function that returns an
242 -- array into the generated procedure with an additional out parameter.
244 procedure Set_Enclosing_Sec_Stack_Return
(N
: Node_Id
);
245 -- N is a return statement for a function that returns its result on the
246 -- secondary stack. This sets the Sec_Stack_Needed_For_Return flag on the
247 -- function and all blocks and loops that the return statement is jumping
248 -- out of. This ensures that the secondary stack is not released; otherwise
249 -- the function result would be reclaimed before returning to the caller.
251 ----------------------------------------------
252 -- Add_Access_Actual_To_Build_In_Place_Call --
253 ----------------------------------------------
255 procedure Add_Access_Actual_To_Build_In_Place_Call
256 (Function_Call
: Node_Id
;
257 Function_Id
: Entity_Id
;
258 Return_Object
: Node_Id
;
259 Is_Access
: Boolean := False)
261 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
262 Obj_Address
: Node_Id
;
263 Obj_Acc_Formal
: Entity_Id
;
266 -- Locate the implicit access parameter in the called function
268 Obj_Acc_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Object_Access
);
270 -- If no return object is provided, then pass null
272 if not Present
(Return_Object
) then
273 Obj_Address
:= Make_Null
(Loc
);
274 Set_Parent
(Obj_Address
, Function_Call
);
276 -- If Return_Object is already an expression of an access type, then use
277 -- it directly, since it must be an access value denoting the return
278 -- object, and couldn't possibly be the return object itself.
281 Obj_Address
:= Return_Object
;
282 Set_Parent
(Obj_Address
, Function_Call
);
284 -- Apply Unrestricted_Access to caller's return object
288 Make_Attribute_Reference
(Loc
,
289 Prefix
=> Return_Object
,
290 Attribute_Name
=> Name_Unrestricted_Access
);
292 Set_Parent
(Return_Object
, Obj_Address
);
293 Set_Parent
(Obj_Address
, Function_Call
);
296 Analyze_And_Resolve
(Obj_Address
, Etype
(Obj_Acc_Formal
));
298 -- Build the parameter association for the new actual and add it to the
299 -- end of the function's actuals.
301 Add_Extra_Actual_To_Call
(Function_Call
, Obj_Acc_Formal
, Obj_Address
);
302 end Add_Access_Actual_To_Build_In_Place_Call
;
304 ------------------------------------------------------
305 -- Add_Unconstrained_Actuals_To_Build_In_Place_Call --
306 ------------------------------------------------------
308 procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
309 (Function_Call
: Node_Id
;
310 Function_Id
: Entity_Id
;
311 Alloc_Form
: BIP_Allocation_Form
:= Unspecified
;
312 Alloc_Form_Exp
: Node_Id
:= Empty
;
313 Pool_Actual
: Node_Id
:= Make_Null
(No_Location
))
315 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
316 Alloc_Form_Actual
: Node_Id
;
317 Alloc_Form_Formal
: Node_Id
;
318 Pool_Formal
: Node_Id
;
321 -- The allocation form generally doesn't need to be passed in the case
322 -- of a constrained result subtype, since normally the caller performs
323 -- the allocation in that case. However this formal is still needed in
324 -- the case where the function has a tagged result, because generally
325 -- such functions can be called in a dispatching context and such calls
326 -- must be handled like calls to class-wide functions.
328 if Is_Constrained
(Underlying_Type
(Etype
(Function_Id
)))
329 and then not Is_Tagged_Type
(Underlying_Type
(Etype
(Function_Id
)))
334 -- Locate the implicit allocation form parameter in the called function.
335 -- Maybe it would be better for each implicit formal of a build-in-place
336 -- function to have a flag or a Uint attribute to identify it. ???
338 Alloc_Form_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Alloc_Form
);
340 if Present
(Alloc_Form_Exp
) then
341 pragma Assert
(Alloc_Form
= Unspecified
);
343 Alloc_Form_Actual
:= Alloc_Form_Exp
;
346 pragma Assert
(Alloc_Form
/= Unspecified
);
349 Make_Integer_Literal
(Loc
,
350 Intval
=> UI_From_Int
(BIP_Allocation_Form
'Pos (Alloc_Form
)));
353 Analyze_And_Resolve
(Alloc_Form_Actual
, Etype
(Alloc_Form_Formal
));
355 -- Build the parameter association for the new actual and add it to the
356 -- end of the function's actuals.
358 Add_Extra_Actual_To_Call
359 (Function_Call
, Alloc_Form_Formal
, Alloc_Form_Actual
);
361 -- Pass the Storage_Pool parameter. This parameter is omitted on
362 -- ZFP as those targets do not support pools.
364 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
365 Pool_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Storage_Pool
);
366 Analyze_And_Resolve
(Pool_Actual
, Etype
(Pool_Formal
));
367 Add_Extra_Actual_To_Call
368 (Function_Call
, Pool_Formal
, Pool_Actual
);
370 end Add_Unconstrained_Actuals_To_Build_In_Place_Call
;
372 -----------------------------------------------------------
373 -- Add_Finalization_Master_Actual_To_Build_In_Place_Call --
374 -----------------------------------------------------------
376 procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
377 (Func_Call
: Node_Id
;
379 Ptr_Typ
: Entity_Id
:= Empty
;
380 Master_Exp
: Node_Id
:= Empty
)
383 if not Needs_BIP_Finalization_Master
(Func_Id
) then
388 Formal
: constant Entity_Id
:=
389 Build_In_Place_Formal
(Func_Id
, BIP_Finalization_Master
);
390 Loc
: constant Source_Ptr
:= Sloc
(Func_Call
);
393 Desig_Typ
: Entity_Id
;
396 -- If there is a finalization master actual, such as the implicit
397 -- finalization master of an enclosing build-in-place function,
398 -- then this must be added as an extra actual of the call.
400 if Present
(Master_Exp
) then
401 Actual
:= Master_Exp
;
403 -- Case where the context does not require an actual master
405 elsif No
(Ptr_Typ
) then
406 Actual
:= Make_Null
(Loc
);
409 Desig_Typ
:= Directly_Designated_Type
(Ptr_Typ
);
411 -- Check for a library-level access type whose designated type has
412 -- suppressed finalization or the access type is subject to pragma
413 -- No_Heap_Finalization. Such an access type lacks a master. Pass
414 -- a null actual to callee in order to signal a missing master.
416 if Is_Library_Level_Entity
(Ptr_Typ
)
417 and then (Finalize_Storage_Only
(Desig_Typ
)
418 or else No_Heap_Finalization
(Ptr_Typ
))
420 Actual
:= Make_Null
(Loc
);
422 -- Types in need of finalization actions
424 elsif Needs_Finalization
(Desig_Typ
) then
426 -- The general mechanism of creating finalization masters for
427 -- anonymous access types is disabled by default, otherwise
428 -- finalization masters will pop all over the place. Such types
429 -- use context-specific masters.
431 if Ekind
(Ptr_Typ
) = E_Anonymous_Access_Type
432 and then No
(Finalization_Master
(Ptr_Typ
))
434 Build_Anonymous_Master
(Ptr_Typ
);
437 -- Access-to-controlled types should always have a master
439 pragma Assert
(Present
(Finalization_Master
(Ptr_Typ
)));
442 Make_Attribute_Reference
(Loc
,
444 New_Occurrence_Of
(Finalization_Master
(Ptr_Typ
), Loc
),
445 Attribute_Name
=> Name_Unrestricted_Access
);
450 Actual
:= Make_Null
(Loc
);
454 Analyze_And_Resolve
(Actual
, Etype
(Formal
));
456 -- Build the parameter association for the new actual and add it to
457 -- the end of the function's actuals.
459 Add_Extra_Actual_To_Call
(Func_Call
, Formal
, Actual
);
461 end Add_Finalization_Master_Actual_To_Build_In_Place_Call
;
463 ------------------------------
464 -- Add_Extra_Actual_To_Call --
465 ------------------------------
467 procedure Add_Extra_Actual_To_Call
468 (Subprogram_Call
: Node_Id
;
469 Extra_Formal
: Entity_Id
;
470 Extra_Actual
: Node_Id
)
472 Loc
: constant Source_Ptr
:= Sloc
(Subprogram_Call
);
473 Param_Assoc
: Node_Id
;
477 Make_Parameter_Association
(Loc
,
478 Selector_Name
=> New_Occurrence_Of
(Extra_Formal
, Loc
),
479 Explicit_Actual_Parameter
=> Extra_Actual
);
481 Set_Parent
(Param_Assoc
, Subprogram_Call
);
482 Set_Parent
(Extra_Actual
, Param_Assoc
);
484 if Present
(Parameter_Associations
(Subprogram_Call
)) then
485 if Nkind
(Last
(Parameter_Associations
(Subprogram_Call
))) =
486 N_Parameter_Association
489 -- Find last named actual, and append
494 L
:= First_Actual
(Subprogram_Call
);
495 while Present
(L
) loop
496 if No
(Next_Actual
(L
)) then
497 Set_Next_Named_Actual
(Parent
(L
), Extra_Actual
);
505 Set_First_Named_Actual
(Subprogram_Call
, Extra_Actual
);
508 Append
(Param_Assoc
, To
=> Parameter_Associations
(Subprogram_Call
));
511 Set_Parameter_Associations
(Subprogram_Call
, New_List
(Param_Assoc
));
512 Set_First_Named_Actual
(Subprogram_Call
, Extra_Actual
);
514 end Add_Extra_Actual_To_Call
;
516 ---------------------------------------------
517 -- Add_Task_Actuals_To_Build_In_Place_Call --
518 ---------------------------------------------
520 procedure Add_Task_Actuals_To_Build_In_Place_Call
521 (Function_Call
: Node_Id
;
522 Function_Id
: Entity_Id
;
523 Master_Actual
: Node_Id
;
524 Chain
: Node_Id
:= Empty
)
526 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
527 Result_Subt
: constant Entity_Id
:=
528 Available_View
(Etype
(Function_Id
));
530 Chain_Actual
: Node_Id
;
531 Chain_Formal
: Node_Id
;
532 Master_Formal
: Node_Id
;
535 -- No such extra parameters are needed if there are no tasks
537 if not Has_Task
(Result_Subt
) then
541 Actual
:= Master_Actual
;
543 -- Use a dummy _master actual in case of No_Task_Hierarchy
545 if Restriction_Active
(No_Task_Hierarchy
) then
546 Actual
:= New_Occurrence_Of
(RTE
(RE_Library_Task_Level
), Loc
);
548 -- In the case where we use the master associated with an access type,
549 -- the actual is an entity and requires an explicit reference.
551 elsif Nkind
(Actual
) = N_Defining_Identifier
then
552 Actual
:= New_Occurrence_Of
(Actual
, Loc
);
555 -- Locate the implicit master parameter in the called function
557 Master_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Task_Master
);
558 Analyze_And_Resolve
(Actual
, Etype
(Master_Formal
));
560 -- Build the parameter association for the new actual and add it to the
561 -- end of the function's actuals.
563 Add_Extra_Actual_To_Call
(Function_Call
, Master_Formal
, Actual
);
565 -- Locate the implicit activation chain parameter in the called function
568 Build_In_Place_Formal
(Function_Id
, BIP_Activation_Chain
);
570 -- Create the actual which is a pointer to the current activation chain
574 Make_Attribute_Reference
(Loc
,
575 Prefix
=> Make_Identifier
(Loc
, Name_uChain
),
576 Attribute_Name
=> Name_Unrestricted_Access
);
578 -- Allocator case; make a reference to the Chain passed in by the caller
582 Make_Attribute_Reference
(Loc
,
583 Prefix
=> New_Occurrence_Of
(Chain
, Loc
),
584 Attribute_Name
=> Name_Unrestricted_Access
);
587 Analyze_And_Resolve
(Chain_Actual
, Etype
(Chain_Formal
));
589 -- Build the parameter association for the new actual and add it to the
590 -- end of the function's actuals.
592 Add_Extra_Actual_To_Call
(Function_Call
, Chain_Formal
, Chain_Actual
);
593 end Add_Task_Actuals_To_Build_In_Place_Call
;
595 -----------------------
596 -- BIP_Formal_Suffix --
597 -----------------------
599 function BIP_Formal_Suffix
(Kind
: BIP_Formal_Kind
) return String is
602 when BIP_Alloc_Form
=>
605 when BIP_Storage_Pool
=>
606 return "BIPstoragepool";
608 when BIP_Finalization_Master
=>
609 return "BIPfinalizationmaster";
611 when BIP_Task_Master
=>
612 return "BIPtaskmaster";
614 when BIP_Activation_Chain
=>
615 return "BIPactivationchain";
617 when BIP_Object_Access
=>
620 end BIP_Formal_Suffix
;
622 ---------------------------
623 -- Build_In_Place_Formal --
624 ---------------------------
626 function Build_In_Place_Formal
628 Kind
: BIP_Formal_Kind
) return Entity_Id
630 Formal_Name
: constant Name_Id
:=
632 (Chars
(Func
), BIP_Formal_Suffix
(Kind
));
633 Extra_Formal
: Entity_Id
:= Extra_Formals
(Func
);
636 -- Maybe it would be better for each implicit formal of a build-in-place
637 -- function to have a flag or a Uint attribute to identify it. ???
639 -- The return type in the function declaration may have been a limited
640 -- view, and the extra formals for the function were not generated at
641 -- that point. At the point of call the full view must be available and
642 -- the extra formals can be created.
644 if No
(Extra_Formal
) then
645 Create_Extra_Formals
(Func
);
646 Extra_Formal
:= Extra_Formals
(Func
);
650 pragma Assert
(Present
(Extra_Formal
));
651 exit when Chars
(Extra_Formal
) = Formal_Name
;
653 Next_Formal_With_Extras
(Extra_Formal
);
657 end Build_In_Place_Formal
;
659 -------------------------------
660 -- Build_Procedure_Body_Form --
661 -------------------------------
663 function Build_Procedure_Body_Form
664 (Func_Id
: Entity_Id
;
665 Func_Body
: Node_Id
) return Node_Id
667 Loc
: constant Source_Ptr
:= Sloc
(Func_Body
);
669 Proc_Decl
: constant Node_Id
:=
670 Next
(Unit_Declaration_Node
(Func_Id
));
671 -- It is assumed that the next node following the declaration of the
672 -- corresponding subprogram spec is the declaration of the procedure
675 Proc_Id
: constant Entity_Id
:= Defining_Entity
(Proc_Decl
);
677 procedure Replace_Returns
(Param_Id
: Entity_Id
; Stmts
: List_Id
);
678 -- Replace each return statement found in the list Stmts with an
679 -- assignment of the return expression to parameter Param_Id.
681 ---------------------
682 -- Replace_Returns --
683 ---------------------
685 procedure Replace_Returns
(Param_Id
: Entity_Id
; Stmts
: List_Id
) is
689 Stmt
:= First
(Stmts
);
690 while Present
(Stmt
) loop
691 if Nkind
(Stmt
) = N_Block_Statement
then
692 Replace_Returns
(Param_Id
, Statements
(Stmt
));
694 elsif Nkind
(Stmt
) = N_Case_Statement
then
698 Alt
:= First
(Alternatives
(Stmt
));
699 while Present
(Alt
) loop
700 Replace_Returns
(Param_Id
, Statements
(Alt
));
705 elsif Nkind
(Stmt
) = N_Extended_Return_Statement
then
707 Ret_Obj
: constant Entity_Id
:=
709 (First
(Return_Object_Declarations
(Stmt
)));
710 Assign
: constant Node_Id
:=
711 Make_Assignment_Statement
(Sloc
(Stmt
),
713 New_Occurrence_Of
(Param_Id
, Loc
),
715 New_Occurrence_Of
(Ret_Obj
, Sloc
(Stmt
)));
719 -- The extended return may just contain the declaration
721 if Present
(Handled_Statement_Sequence
(Stmt
)) then
722 Stmts
:= Statements
(Handled_Statement_Sequence
(Stmt
));
727 Set_Assignment_OK
(Name
(Assign
));
730 Make_Block_Statement
(Sloc
(Stmt
),
732 Return_Object_Declarations
(Stmt
),
733 Handled_Statement_Sequence
=>
734 Make_Handled_Sequence_Of_Statements
(Loc
,
735 Statements
=> Stmts
)));
737 Replace_Returns
(Param_Id
, Stmts
);
739 Append_To
(Stmts
, Assign
);
740 Append_To
(Stmts
, Make_Simple_Return_Statement
(Loc
));
743 elsif Nkind
(Stmt
) = N_If_Statement
then
744 Replace_Returns
(Param_Id
, Then_Statements
(Stmt
));
745 Replace_Returns
(Param_Id
, Else_Statements
(Stmt
));
750 Part
:= First
(Elsif_Parts
(Stmt
));
751 while Present
(Part
) loop
752 Replace_Returns
(Param_Id
, Then_Statements
(Part
));
757 elsif Nkind
(Stmt
) = N_Loop_Statement
then
758 Replace_Returns
(Param_Id
, Statements
(Stmt
));
760 elsif Nkind
(Stmt
) = N_Simple_Return_Statement
then
767 Make_Assignment_Statement
(Sloc
(Stmt
),
768 Name
=> New_Occurrence_Of
(Param_Id
, Loc
),
769 Expression
=> Relocate_Node
(Expression
(Stmt
))));
771 Insert_After
(Stmt
, Make_Simple_Return_Statement
(Loc
));
773 -- Skip the added return
787 -- Start of processing for Build_Procedure_Body_Form
790 -- This routine replaces the original function body:
792 -- function F (...) return Array_Typ is
798 -- with the following:
800 -- procedure P (..., Result : out Array_Typ) is
803 -- Result := Something;
807 Statements
(Handled_Statement_Sequence
(Func_Body
));
808 Replace_Returns
(Last_Entity
(Proc_Id
), Stmts
);
811 Make_Subprogram_Body
(Loc
,
813 Copy_Subprogram_Spec
(Specification
(Proc_Decl
)),
814 Declarations
=> Declarations
(Func_Body
),
815 Handled_Statement_Sequence
=>
816 Make_Handled_Sequence_Of_Statements
(Loc
,
817 Statements
=> Stmts
));
819 -- If the function is a generic instance, so is the new procedure.
820 -- Set flag accordingly so that the proper renaming declarations are
823 Set_Is_Generic_Instance
(Proc_Id
, Is_Generic_Instance
(Func_Id
));
825 end Build_Procedure_Body_Form
;
827 --------------------------------
828 -- Check_Overriding_Operation --
829 --------------------------------
831 procedure Check_Overriding_Operation
(Subp
: Entity_Id
) is
832 Typ
: constant Entity_Id
:= Find_Dispatching_Type
(Subp
);
833 Op_List
: constant Elist_Id
:= Primitive_Operations
(Typ
);
839 if Is_Derived_Type
(Typ
)
840 and then not Is_Private_Type
(Typ
)
841 and then In_Open_Scopes
(Scope
(Etype
(Typ
)))
842 and then Is_Base_Type
(Typ
)
844 -- Subp overrides an inherited private operation if there is an
845 -- inherited operation with a different name than Subp (see
846 -- Derive_Subprogram) whose Alias is a hidden subprogram with the
847 -- same name as Subp.
849 Op_Elmt
:= First_Elmt
(Op_List
);
850 while Present
(Op_Elmt
) loop
851 Prim_Op
:= Node
(Op_Elmt
);
852 Par_Op
:= Alias
(Prim_Op
);
855 and then not Comes_From_Source
(Prim_Op
)
856 and then Chars
(Prim_Op
) /= Chars
(Par_Op
)
857 and then Chars
(Par_Op
) = Chars
(Subp
)
858 and then Is_Hidden
(Par_Op
)
859 and then Type_Conformant
(Prim_Op
, Subp
)
861 Set_DT_Position_Value
(Subp
, DT_Position
(Prim_Op
));
867 end Check_Overriding_Operation
;
869 -------------------------------
870 -- Detect_Infinite_Recursion --
871 -------------------------------
873 procedure Detect_Infinite_Recursion
(N
: Node_Id
; Spec
: Entity_Id
) is
874 Loc
: constant Source_Ptr
:= Sloc
(N
);
876 Var_List
: constant Elist_Id
:= New_Elmt_List
;
877 -- List of globals referenced by body of procedure
879 Call_List
: constant Elist_Id
:= New_Elmt_List
;
880 -- List of recursive calls in body of procedure
882 Shad_List
: constant Elist_Id
:= New_Elmt_List
;
883 -- List of entity id's for entities created to capture the value of
884 -- referenced globals on entry to the procedure.
886 Scop
: constant Uint
:= Scope_Depth
(Spec
);
887 -- This is used to record the scope depth of the current procedure, so
888 -- that we can identify global references.
890 Max_Vars
: constant := 4;
891 -- Do not test more than four global variables
893 Count_Vars
: Natural := 0;
894 -- Count variables found so far
906 function Process
(Nod
: Node_Id
) return Traverse_Result
;
907 -- Function to traverse the subprogram body (using Traverse_Func)
913 function Process
(Nod
: Node_Id
) return Traverse_Result
is
917 if Nkind
(Nod
) = N_Procedure_Call_Statement
then
919 -- Case of one of the detected recursive calls
921 if Is_Entity_Name
(Name
(Nod
))
922 and then Has_Recursive_Call
(Entity
(Name
(Nod
)))
923 and then Entity
(Name
(Nod
)) = Spec
925 Append_Elmt
(Nod
, Call_List
);
928 -- Any other procedure call may have side effects
934 -- A call to a pure function can always be ignored
936 elsif Nkind
(Nod
) = N_Function_Call
937 and then Is_Entity_Name
(Name
(Nod
))
938 and then Is_Pure
(Entity
(Name
(Nod
)))
942 -- Case of an identifier reference
944 elsif Nkind
(Nod
) = N_Identifier
then
947 -- If no entity, then ignore the reference
949 -- Not clear why this can happen. To investigate, remove this
950 -- test and look at the crash that occurs here in 3401-004 ???
955 -- Ignore entities with no Scope, again not clear how this
956 -- can happen, to investigate, look at 4108-008 ???
958 elsif No
(Scope
(Ent
)) then
961 -- Ignore the reference if not to a more global object
963 elsif Scope_Depth
(Scope
(Ent
)) >= Scop
then
966 -- References to types, exceptions and constants are always OK
969 or else Ekind
(Ent
) = E_Exception
970 or else Ekind
(Ent
) = E_Constant
974 -- If other than a non-volatile scalar variable, we have some
975 -- kind of global reference (e.g. to a function) that we cannot
976 -- deal with so we forget the attempt.
978 elsif Ekind
(Ent
) /= E_Variable
979 or else not Is_Scalar_Type
(Etype
(Ent
))
980 or else Treat_As_Volatile
(Ent
)
984 -- Otherwise we have a reference to a global scalar
987 -- Loop through global entities already detected
989 Elm
:= First_Elmt
(Var_List
);
991 -- If not detected before, record this new global reference
994 Count_Vars
:= Count_Vars
+ 1;
996 if Count_Vars
<= Max_Vars
then
997 Append_Elmt
(Entity
(Nod
), Var_List
);
1004 -- If recorded before, ignore
1006 elsif Node
(Elm
) = Entity
(Nod
) then
1009 -- Otherwise keep looking
1019 -- For all other node kinds, recursively visit syntactic children
1026 function Traverse_Body
is new Traverse_Func
(Process
);
1028 -- Start of processing for Detect_Infinite_Recursion
1031 -- Do not attempt detection in No_Implicit_Conditional mode, since we
1032 -- won't be able to generate the code to handle the recursion in any
1035 if Restriction_Active
(No_Implicit_Conditionals
) then
1039 -- Otherwise do traversal and quit if we get abandon signal
1041 if Traverse_Body
(N
) = Abandon
then
1044 -- We must have a call, since Has_Recursive_Call was set. If not just
1045 -- ignore (this is only an error check, so if we have a funny situation,
1046 -- due to bugs or errors, we do not want to bomb).
1048 elsif Is_Empty_Elmt_List
(Call_List
) then
1052 -- Here is the case where we detect recursion at compile time
1054 -- Push our current scope for analyzing the declarations and code that
1055 -- we will insert for the checking.
1059 -- This loop builds temporary variables for each of the referenced
1060 -- globals, so that at the end of the loop the list Shad_List contains
1061 -- these temporaries in one-to-one correspondence with the elements in
1065 Elm
:= First_Elmt
(Var_List
);
1066 while Present
(Elm
) loop
1068 Ent
:= Make_Temporary
(Loc
, 'S');
1069 Append_Elmt
(Ent
, Shad_List
);
1071 -- Insert a declaration for this temporary at the start of the
1072 -- declarations for the procedure. The temporaries are declared as
1073 -- constant objects initialized to the current values of the
1074 -- corresponding temporaries.
1077 Make_Object_Declaration
(Loc
,
1078 Defining_Identifier
=> Ent
,
1079 Object_Definition
=> New_Occurrence_Of
(Etype
(Var
), Loc
),
1080 Constant_Present
=> True,
1081 Expression
=> New_Occurrence_Of
(Var
, Loc
));
1084 Prepend
(Decl
, Declarations
(N
));
1086 Insert_After
(Last
, Decl
);
1094 -- Loop through calls
1096 Call
:= First_Elmt
(Call_List
);
1097 while Present
(Call
) loop
1099 -- Build a predicate expression of the form
1102 -- and then global1 = temp1
1103 -- and then global2 = temp2
1106 -- This predicate determines if any of the global values
1107 -- referenced by the procedure have changed since the
1108 -- current call, if not an infinite recursion is assured.
1110 Test
:= New_Occurrence_Of
(Standard_True
, Loc
);
1112 Elm1
:= First_Elmt
(Var_List
);
1113 Elm2
:= First_Elmt
(Shad_List
);
1114 while Present
(Elm1
) loop
1120 Left_Opnd
=> New_Occurrence_Of
(Node
(Elm1
), Loc
),
1121 Right_Opnd
=> New_Occurrence_Of
(Node
(Elm2
), Loc
)));
1127 -- Now we replace the call with the sequence
1129 -- if no-changes (see above) then
1130 -- raise Storage_Error;
1135 Rewrite
(Node
(Call
),
1136 Make_If_Statement
(Loc
,
1138 Then_Statements
=> New_List
(
1139 Make_Raise_Storage_Error
(Loc
,
1140 Reason
=> SE_Infinite_Recursion
)),
1142 Else_Statements
=> New_List
(
1143 Relocate_Node
(Node
(Call
)))));
1145 Analyze
(Node
(Call
));
1150 -- Remove temporary scope stack entry used for analysis
1153 end Detect_Infinite_Recursion
;
1155 --------------------
1156 -- Expand_Actuals --
1157 --------------------
1159 procedure Expand_Actuals
1162 Post_Call
: out List_Id
)
1164 Loc
: constant Source_Ptr
:= Sloc
(N
);
1168 E_Actual
: Entity_Id
;
1169 E_Formal
: Entity_Id
;
1171 procedure Add_Call_By_Copy_Code
;
1172 -- For cases where the parameter must be passed by copy, this routine
1173 -- generates a temporary variable into which the actual is copied and
1174 -- then passes this as the parameter. For an OUT or IN OUT parameter,
1175 -- an assignment is also generated to copy the result back. The call
1176 -- also takes care of any constraint checks required for the type
1177 -- conversion case (on both the way in and the way out).
1179 procedure Add_Simple_Call_By_Copy_Code
;
1180 -- This is similar to the above, but is used in cases where we know
1181 -- that all that is needed is to simply create a temporary and copy
1182 -- the value in and out of the temporary.
1184 procedure Add_Validation_Call_By_Copy_Code
(Act
: Node_Id
);
1185 -- Perform copy-back for actual parameter Act which denotes a validation
1188 procedure Check_Fortran_Logical
;
1189 -- A value of type Logical that is passed through a formal parameter
1190 -- must be normalized because .TRUE. usually does not have the same
1191 -- representation as True. We assume that .FALSE. = False = 0.
1192 -- What about functions that return a logical type ???
1194 function Is_Legal_Copy
return Boolean;
1195 -- Check that an actual can be copied before generating the temporary
1196 -- to be used in the call. If the actual is of a by_reference type then
1197 -- the program is illegal (this can only happen in the presence of
1198 -- rep. clauses that force an incorrect alignment). If the formal is
1199 -- a by_reference parameter imposed by a DEC pragma, emit a warning to
1200 -- the effect that this might lead to unaligned arguments.
1202 function Make_Var
(Actual
: Node_Id
) return Entity_Id
;
1203 -- Returns an entity that refers to the given actual parameter, Actual
1204 -- (not including any type conversion). If Actual is an entity name,
1205 -- then this entity is returned unchanged, otherwise a renaming is
1206 -- created to provide an entity for the actual.
1208 procedure Reset_Packed_Prefix
;
1209 -- The expansion of a packed array component reference is delayed in
1210 -- the context of a call. Now we need to complete the expansion, so we
1211 -- unmark the analyzed bits in all prefixes.
1213 ---------------------------
1214 -- Add_Call_By_Copy_Code --
1215 ---------------------------
1217 procedure Add_Call_By_Copy_Code
is
1220 F_Typ
: Entity_Id
:= Etype
(Formal
);
1228 if not Is_Legal_Copy
then
1232 Temp
:= Make_Temporary
(Loc
, 'T', Actual
);
1234 -- Handle formals whose type comes from the limited view
1236 if From_Limited_With
(F_Typ
)
1237 and then Has_Non_Limited_View
(F_Typ
)
1239 F_Typ
:= Non_Limited_View
(F_Typ
);
1242 -- Use formal type for temp, unless formal type is an unconstrained
1243 -- array, in which case we don't have to worry about bounds checks,
1244 -- and we use the actual type, since that has appropriate bounds.
1246 if Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
) then
1247 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1249 Indic
:= New_Occurrence_Of
(F_Typ
, Loc
);
1252 if Nkind
(Actual
) = N_Type_Conversion
then
1253 V_Typ
:= Etype
(Expression
(Actual
));
1255 -- If the formal is an (in-)out parameter, capture the name
1256 -- of the variable in order to build the post-call assignment.
1258 Var
:= Make_Var
(Expression
(Actual
));
1260 Crep
:= not Same_Representation
1261 (F_Typ
, Etype
(Expression
(Actual
)));
1264 V_Typ
:= Etype
(Actual
);
1265 Var
:= Make_Var
(Actual
);
1269 -- Setup initialization for case of in out parameter, or an out
1270 -- parameter where the formal is an unconstrained array (in the
1271 -- latter case, we have to pass in an object with bounds).
1273 -- If this is an out parameter, the initial copy is wasteful, so as
1274 -- an optimization for the one-dimensional case we extract the
1275 -- bounds of the actual and build an uninitialized temporary of the
1278 if Ekind
(Formal
) = E_In_Out_Parameter
1279 or else (Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
))
1281 if Nkind
(Actual
) = N_Type_Conversion
then
1282 if Conversion_OK
(Actual
) then
1283 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1285 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1288 elsif Ekind
(Formal
) = E_Out_Parameter
1289 and then Is_Array_Type
(F_Typ
)
1290 and then Number_Dimensions
(F_Typ
) = 1
1291 and then not Has_Non_Null_Base_Init_Proc
(F_Typ
)
1293 -- Actual is a one-dimensional array or slice, and the type
1294 -- requires no initialization. Create a temporary of the
1295 -- right size, but do not copy actual into it (optimization).
1299 Make_Subtype_Indication
(Loc
,
1300 Subtype_Mark
=> New_Occurrence_Of
(F_Typ
, Loc
),
1302 Make_Index_Or_Discriminant_Constraint
(Loc
,
1303 Constraints
=> New_List
(
1306 Make_Attribute_Reference
(Loc
,
1307 Prefix
=> New_Occurrence_Of
(Var
, Loc
),
1308 Attribute_Name
=> Name_First
),
1310 Make_Attribute_Reference
(Loc
,
1311 Prefix
=> New_Occurrence_Of
(Var
, Loc
),
1312 Attribute_Name
=> Name_Last
)))));
1315 Init
:= New_Occurrence_Of
(Var
, Loc
);
1318 -- An initialization is created for packed conversions as
1319 -- actuals for out parameters to enable Make_Object_Declaration
1320 -- to determine the proper subtype for N_Node. Note that this
1321 -- is wasteful because the extra copying on the call side is
1322 -- not required for such out parameters. ???
1324 elsif Ekind
(Formal
) = E_Out_Parameter
1325 and then Nkind
(Actual
) = N_Type_Conversion
1326 and then (Is_Bit_Packed_Array
(F_Typ
)
1328 Is_Bit_Packed_Array
(Etype
(Expression
(Actual
))))
1330 if Conversion_OK
(Actual
) then
1331 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1333 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1336 elsif Ekind
(Formal
) = E_In_Parameter
then
1338 -- Handle the case in which the actual is a type conversion
1340 if Nkind
(Actual
) = N_Type_Conversion
then
1341 if Conversion_OK
(Actual
) then
1342 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1344 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1347 Init
:= New_Occurrence_Of
(Var
, Loc
);
1355 Make_Object_Declaration
(Loc
,
1356 Defining_Identifier
=> Temp
,
1357 Object_Definition
=> Indic
,
1358 Expression
=> Init
);
1359 Set_Assignment_OK
(N_Node
);
1360 Insert_Action
(N
, N_Node
);
1362 -- Now, normally the deal here is that we use the defining
1363 -- identifier created by that object declaration. There is
1364 -- one exception to this. In the change of representation case
1365 -- the above declaration will end up looking like:
1367 -- temp : type := identifier;
1369 -- And in this case we might as well use the identifier directly
1370 -- and eliminate the temporary. Note that the analysis of the
1371 -- declaration was not a waste of time in that case, since it is
1372 -- what generated the necessary change of representation code. If
1373 -- the change of representation introduced additional code, as in
1374 -- a fixed-integer conversion, the expression is not an identifier
1375 -- and must be kept.
1378 and then Present
(Expression
(N_Node
))
1379 and then Is_Entity_Name
(Expression
(N_Node
))
1381 Temp
:= Entity
(Expression
(N_Node
));
1382 Rewrite
(N_Node
, Make_Null_Statement
(Loc
));
1385 -- For IN parameter, all we do is to replace the actual
1387 if Ekind
(Formal
) = E_In_Parameter
then
1388 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1391 -- Processing for OUT or IN OUT parameter
1394 -- Kill current value indications for the temporary variable we
1395 -- created, since we just passed it as an OUT parameter.
1397 Kill_Current_Values
(Temp
);
1398 Set_Is_Known_Valid
(Temp
, False);
1400 -- If type conversion, use reverse conversion on exit
1402 if Nkind
(Actual
) = N_Type_Conversion
then
1403 if Conversion_OK
(Actual
) then
1404 Expr
:= OK_Convert_To
(V_Typ
, New_Occurrence_Of
(Temp
, Loc
));
1406 Expr
:= Convert_To
(V_Typ
, New_Occurrence_Of
(Temp
, Loc
));
1409 Expr
:= New_Occurrence_Of
(Temp
, Loc
);
1412 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1415 -- If the actual is a conversion of a packed reference, it may
1416 -- already have been expanded by Remove_Side_Effects, and the
1417 -- resulting variable is a temporary which does not designate
1418 -- the proper out-parameter, which may not be addressable. In
1419 -- that case, generate an assignment to the original expression
1420 -- (before expansion of the packed reference) so that the proper
1421 -- expansion of assignment to a packed component can take place.
1428 if Is_Renaming_Of_Object
(Var
)
1429 and then Nkind
(Renamed_Object
(Var
)) = N_Selected_Component
1430 and then Nkind
(Original_Node
(Prefix
(Renamed_Object
(Var
))))
1431 = N_Indexed_Component
1433 Has_Non_Standard_Rep
(Etype
(Prefix
(Renamed_Object
(Var
))))
1435 Obj
:= Renamed_Object
(Var
);
1437 Make_Selected_Component
(Loc
,
1439 New_Copy_Tree
(Original_Node
(Prefix
(Obj
))),
1440 Selector_Name
=> New_Copy
(Selector_Name
(Obj
)));
1441 Reset_Analyzed_Flags
(Lhs
);
1444 Lhs
:= New_Occurrence_Of
(Var
, Loc
);
1447 Set_Assignment_OK
(Lhs
);
1449 if Is_Access_Type
(E_Formal
)
1450 and then Is_Entity_Name
(Lhs
)
1452 Present
(Effective_Extra_Accessibility
(Entity
(Lhs
)))
1454 -- Copyback target is an Ada 2012 stand-alone object of an
1455 -- anonymous access type.
1457 pragma Assert
(Ada_Version
>= Ada_2012
);
1459 if Type_Access_Level
(E_Formal
) >
1460 Object_Access_Level
(Lhs
)
1462 Append_To
(Post_Call
,
1463 Make_Raise_Program_Error
(Loc
,
1464 Reason
=> PE_Accessibility_Check_Failed
));
1467 Append_To
(Post_Call
,
1468 Make_Assignment_Statement
(Loc
,
1470 Expression
=> Expr
));
1472 -- We would like to somehow suppress generation of the
1473 -- extra_accessibility assignment generated by the expansion
1474 -- of the above assignment statement. It's not a correctness
1475 -- issue because the following assignment renders it dead,
1476 -- but generating back-to-back assignments to the same
1477 -- target is undesirable. ???
1479 Append_To
(Post_Call
,
1480 Make_Assignment_Statement
(Loc
,
1481 Name
=> New_Occurrence_Of
(
1482 Effective_Extra_Accessibility
(Entity
(Lhs
)), Loc
),
1483 Expression
=> Make_Integer_Literal
(Loc
,
1484 Type_Access_Level
(E_Formal
))));
1487 Append_To
(Post_Call
,
1488 Make_Assignment_Statement
(Loc
,
1490 Expression
=> Expr
));
1494 end Add_Call_By_Copy_Code
;
1496 ----------------------------------
1497 -- Add_Simple_Call_By_Copy_Code --
1498 ----------------------------------
1500 procedure Add_Simple_Call_By_Copy_Code
is
1502 F_Typ
: Entity_Id
:= Etype
(Formal
);
1511 if not Is_Legal_Copy
then
1515 -- Handle formals whose type comes from the limited view
1517 if From_Limited_With
(F_Typ
)
1518 and then Has_Non_Limited_View
(F_Typ
)
1520 F_Typ
:= Non_Limited_View
(F_Typ
);
1523 -- Use formal type for temp, unless formal type is an unconstrained
1524 -- array, in which case we don't have to worry about bounds checks,
1525 -- and we use the actual type, since that has appropriate bounds.
1527 if Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
) then
1528 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1530 Indic
:= New_Occurrence_Of
(F_Typ
, Loc
);
1533 -- Prepare to generate code
1535 Reset_Packed_Prefix
;
1537 Temp
:= Make_Temporary
(Loc
, 'T', Actual
);
1538 Incod
:= Relocate_Node
(Actual
);
1539 Outcod
:= New_Copy_Tree
(Incod
);
1541 -- Generate declaration of temporary variable, initializing it
1542 -- with the input parameter unless we have an OUT formal or
1543 -- this is an initialization call.
1545 -- If the formal is an out parameter with discriminants, the
1546 -- discriminants must be captured even if the rest of the object
1547 -- is in principle uninitialized, because the discriminants may
1548 -- be read by the called subprogram.
1550 if Ekind
(Formal
) = E_Out_Parameter
then
1553 if Has_Discriminants
(F_Typ
) then
1554 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1557 elsif Inside_Init_Proc
then
1559 -- Could use a comment here to match comment below ???
1561 if Nkind
(Actual
) /= N_Selected_Component
1563 not Has_Discriminant_Dependent_Constraint
1564 (Entity
(Selector_Name
(Actual
)))
1568 -- Otherwise, keep the component in order to generate the proper
1569 -- actual subtype, that depends on enclosing discriminants.
1577 Make_Object_Declaration
(Loc
,
1578 Defining_Identifier
=> Temp
,
1579 Object_Definition
=> Indic
,
1580 Expression
=> Incod
);
1585 -- If the call is to initialize a component of a composite type,
1586 -- and the component does not depend on discriminants, use the
1587 -- actual type of the component. This is required in case the
1588 -- component is constrained, because in general the formal of the
1589 -- initialization procedure will be unconstrained. Note that if
1590 -- the component being initialized is constrained by an enclosing
1591 -- discriminant, the presence of the initialization in the
1592 -- declaration will generate an expression for the actual subtype.
1594 Set_No_Initialization
(Decl
);
1595 Set_Object_Definition
(Decl
,
1596 New_Occurrence_Of
(Etype
(Actual
), Loc
));
1599 Insert_Action
(N
, Decl
);
1601 -- The actual is simply a reference to the temporary
1603 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1605 -- Generate copy out if OUT or IN OUT parameter
1607 if Ekind
(Formal
) /= E_In_Parameter
then
1609 Rhs
:= New_Occurrence_Of
(Temp
, Loc
);
1611 -- Deal with conversion
1613 if Nkind
(Lhs
) = N_Type_Conversion
then
1614 Lhs
:= Expression
(Lhs
);
1615 Rhs
:= Convert_To
(Etype
(Actual
), Rhs
);
1618 Append_To
(Post_Call
,
1619 Make_Assignment_Statement
(Loc
,
1621 Expression
=> Rhs
));
1622 Set_Assignment_OK
(Name
(Last
(Post_Call
)));
1624 end Add_Simple_Call_By_Copy_Code
;
1626 --------------------------------------
1627 -- Add_Validation_Call_By_Copy_Code --
1628 --------------------------------------
1630 procedure Add_Validation_Call_By_Copy_Code
(Act
: Node_Id
) is
1633 Obj_Typ
: Entity_Id
;
1640 -- Use the expression when the context qualifies a reference in some
1643 while Nkind_In
(Var
, N_Qualified_Expression
,
1645 N_Unchecked_Type_Conversion
)
1647 Var
:= Expression
(Var
);
1650 -- Copy the value of the validation variable back into the object
1653 if Is_Entity_Name
(Var
) then
1654 Var_Id
:= Entity
(Var
);
1655 Obj
:= Validated_Object
(Var_Id
);
1656 Obj_Typ
:= Etype
(Obj
);
1658 Expr
:= New_Occurrence_Of
(Var_Id
, Loc
);
1660 -- A type conversion is needed when the validation variable and
1661 -- the validated object carry different types. This case occurs
1662 -- when the actual is qualified in some fashion.
1665 -- subtype Int is Integer range ...;
1666 -- procedure Call (Val : in out Integer);
1670 -- Call (Integer (Object));
1674 -- Var : Integer := Object; -- conversion to base type
1675 -- if not Var'Valid then -- validity check
1676 -- Call (Var); -- modify Var
1677 -- Object := Int (Var); -- conversion to subtype
1679 if Etype
(Var_Id
) /= Obj_Typ
then
1681 Make_Type_Conversion
(Loc
,
1682 Subtype_Mark
=> New_Occurrence_Of
(Obj_Typ
, Loc
),
1683 Expression
=> Expr
);
1689 -- Object := Object_Type (Var);
1691 Append_To
(Post_Call
,
1692 Make_Assignment_Statement
(Loc
,
1694 Expression
=> Expr
));
1696 -- If the flow reaches this point, then this routine was invoked with
1697 -- an actual which does not denote a validation variable.
1700 pragma Assert
(False);
1703 end Add_Validation_Call_By_Copy_Code
;
1705 ---------------------------
1706 -- Check_Fortran_Logical --
1707 ---------------------------
1709 procedure Check_Fortran_Logical
is
1710 Logical
: constant Entity_Id
:= Etype
(Formal
);
1713 -- Note: this is very incomplete, e.g. it does not handle arrays
1714 -- of logical values. This is really not the right approach at all???)
1717 if Convention
(Subp
) = Convention_Fortran
1718 and then Root_Type
(Etype
(Formal
)) = Standard_Boolean
1719 and then Ekind
(Formal
) /= E_In_Parameter
1721 Var
:= Make_Var
(Actual
);
1722 Append_To
(Post_Call
,
1723 Make_Assignment_Statement
(Loc
,
1724 Name
=> New_Occurrence_Of
(Var
, Loc
),
1726 Unchecked_Convert_To
(
1729 Left_Opnd
=> New_Occurrence_Of
(Var
, Loc
),
1731 Unchecked_Convert_To
(
1733 New_Occurrence_Of
(Standard_False
, Loc
))))));
1735 end Check_Fortran_Logical
;
1741 function Is_Legal_Copy
return Boolean is
1743 -- An attempt to copy a value of such a type can only occur if
1744 -- representation clauses give the actual a misaligned address.
1746 if Is_By_Reference_Type
(Etype
(Formal
)) then
1748 -- If the front-end does not perform full type layout, the actual
1749 -- may in fact be properly aligned but there is not enough front-
1750 -- end information to determine this. In that case gigi will emit
1751 -- an error if a copy is not legal, or generate the proper code.
1752 -- For other backends we report the error now.
1754 -- Seems wrong to be issuing an error in the expander, since it
1755 -- will be missed in -gnatc mode ???
1757 if Frontend_Layout_On_Target
then
1759 ("misaligned actual cannot be passed by reference", Actual
);
1764 -- For users of Starlet, we assume that the specification of by-
1765 -- reference mechanism is mandatory. This may lead to unaligned
1766 -- objects but at least for DEC legacy code it is known to work.
1767 -- The warning will alert users of this code that a problem may
1770 elsif Mechanism
(Formal
) = By_Reference
1771 and then Is_Valued_Procedure
(Scope
(Formal
))
1774 ("by_reference actual may be misaligned??", Actual
);
1786 function Make_Var
(Actual
: Node_Id
) return Entity_Id
is
1790 if Is_Entity_Name
(Actual
) then
1791 return Entity
(Actual
);
1794 Var
:= Make_Temporary
(Loc
, 'T', Actual
);
1797 Make_Object_Renaming_Declaration
(Loc
,
1798 Defining_Identifier
=> Var
,
1800 New_Occurrence_Of
(Etype
(Actual
), Loc
),
1801 Name
=> Relocate_Node
(Actual
));
1803 Insert_Action
(N
, N_Node
);
1808 -------------------------
1809 -- Reset_Packed_Prefix --
1810 -------------------------
1812 procedure Reset_Packed_Prefix
is
1813 Pfx
: Node_Id
:= Actual
;
1816 Set_Analyzed
(Pfx
, False);
1818 not Nkind_In
(Pfx
, N_Selected_Component
, N_Indexed_Component
);
1819 Pfx
:= Prefix
(Pfx
);
1821 end Reset_Packed_Prefix
;
1823 -- Start of processing for Expand_Actuals
1826 Post_Call
:= New_List
;
1828 Formal
:= First_Formal
(Subp
);
1829 Actual
:= First_Actual
(N
);
1830 while Present
(Formal
) loop
1831 E_Formal
:= Etype
(Formal
);
1832 E_Actual
:= Etype
(Actual
);
1834 -- Handle formals whose type comes from the limited view
1836 if From_Limited_With
(E_Formal
)
1837 and then Has_Non_Limited_View
(E_Formal
)
1839 E_Formal
:= Non_Limited_View
(E_Formal
);
1842 if Is_Scalar_Type
(E_Formal
)
1843 or else Nkind
(Actual
) = N_Slice
1845 Check_Fortran_Logical
;
1849 elsif Ekind
(Formal
) /= E_Out_Parameter
then
1851 -- The unusual case of the current instance of a protected type
1852 -- requires special handling. This can only occur in the context
1853 -- of a call within the body of a protected operation.
1855 if Is_Entity_Name
(Actual
)
1856 and then Ekind
(Entity
(Actual
)) = E_Protected_Type
1857 and then In_Open_Scopes
(Entity
(Actual
))
1859 if Scope
(Subp
) /= Entity
(Actual
) then
1861 ("operation outside protected type may not "
1862 & "call back its protected operations??", Actual
);
1866 Expand_Protected_Object_Reference
(N
, Entity
(Actual
)));
1869 -- Ada 2005 (AI-318-02): If the actual parameter is a call to a
1870 -- build-in-place function, then a temporary return object needs
1871 -- to be created and access to it must be passed to the function.
1872 -- Currently we limit such functions to those with inherently
1873 -- limited result subtypes, but eventually we plan to expand the
1874 -- functions that are treated as build-in-place to include other
1875 -- composite result types.
1877 if Is_Build_In_Place_Function_Call
(Actual
) then
1878 Make_Build_In_Place_Call_In_Anonymous_Context
(Actual
);
1881 Apply_Constraint_Check
(Actual
, E_Formal
);
1883 -- Out parameter case. No constraint checks on access type
1886 elsif Is_Access_Type
(E_Formal
) then
1891 elsif Has_Discriminants
(Base_Type
(E_Formal
))
1892 or else Has_Non_Null_Base_Init_Proc
(E_Formal
)
1894 Apply_Constraint_Check
(Actual
, E_Formal
);
1899 Apply_Constraint_Check
(Actual
, Base_Type
(E_Formal
));
1902 -- Processing for IN-OUT and OUT parameters
1904 if Ekind
(Formal
) /= E_In_Parameter
then
1906 -- For type conversions of arrays, apply length/range checks
1908 if Is_Array_Type
(E_Formal
)
1909 and then Nkind
(Actual
) = N_Type_Conversion
1911 if Is_Constrained
(E_Formal
) then
1912 Apply_Length_Check
(Expression
(Actual
), E_Formal
);
1914 Apply_Range_Check
(Expression
(Actual
), E_Formal
);
1918 -- The actual denotes a variable which captures the value of an
1919 -- object for validation purposes. Add a copy-back to reflect any
1920 -- potential changes in value back into the original object.
1922 -- Var : ... := Object;
1923 -- if not Var'Valid then -- validity check
1924 -- Call (Var); -- modify var
1925 -- Object := Var; -- update Object
1927 -- This case is given higher priority because the subsequent check
1928 -- for type conversion may add an extra copy of the variable and
1929 -- prevent proper value propagation back in the original object.
1931 if Is_Validation_Variable_Reference
(Actual
) then
1932 Add_Validation_Call_By_Copy_Code
(Actual
);
1934 -- If argument is a type conversion for a type that is passed by
1935 -- copy, then we must pass the parameter by copy.
1937 elsif Nkind
(Actual
) = N_Type_Conversion
1939 (Is_Numeric_Type
(E_Formal
)
1940 or else Is_Access_Type
(E_Formal
)
1941 or else Is_Enumeration_Type
(E_Formal
)
1942 or else Is_Bit_Packed_Array
(Etype
(Formal
))
1943 or else Is_Bit_Packed_Array
(Etype
(Expression
(Actual
)))
1945 -- Also pass by copy if change of representation
1947 or else not Same_Representation
1949 Etype
(Expression
(Actual
))))
1951 Add_Call_By_Copy_Code
;
1953 -- References to components of bit-packed arrays are expanded
1954 -- at this point, rather than at the point of analysis of the
1955 -- actuals, to handle the expansion of the assignment to
1956 -- [in] out parameters.
1958 elsif Is_Ref_To_Bit_Packed_Array
(Actual
) then
1959 Add_Simple_Call_By_Copy_Code
;
1961 -- If a non-scalar actual is possibly bit-aligned, we need a copy
1962 -- because the back-end cannot cope with such objects. In other
1963 -- cases where alignment forces a copy, the back-end generates
1964 -- it properly. It should not be generated unconditionally in the
1965 -- front-end because it does not know precisely the alignment
1966 -- requirements of the target, and makes too conservative an
1967 -- estimate, leading to superfluous copies or spurious errors
1968 -- on by-reference parameters.
1970 elsif Nkind
(Actual
) = N_Selected_Component
1972 Component_May_Be_Bit_Aligned
(Entity
(Selector_Name
(Actual
)))
1973 and then not Represented_As_Scalar
(Etype
(Formal
))
1975 Add_Simple_Call_By_Copy_Code
;
1977 -- References to slices of bit-packed arrays are expanded
1979 elsif Is_Ref_To_Bit_Packed_Slice
(Actual
) then
1980 Add_Call_By_Copy_Code
;
1982 -- References to possibly unaligned slices of arrays are expanded
1984 elsif Is_Possibly_Unaligned_Slice
(Actual
) then
1985 Add_Call_By_Copy_Code
;
1987 -- Deal with access types where the actual subtype and the
1988 -- formal subtype are not the same, requiring a check.
1990 -- It is necessary to exclude tagged types because of "downward
1991 -- conversion" errors.
1993 elsif Is_Access_Type
(E_Formal
)
1994 and then not Same_Type
(E_Formal
, E_Actual
)
1995 and then not Is_Tagged_Type
(Designated_Type
(E_Formal
))
1997 Add_Call_By_Copy_Code
;
1999 -- If the actual is not a scalar and is marked for volatile
2000 -- treatment, whereas the formal is not volatile, then pass
2001 -- by copy unless it is a by-reference type.
2003 -- Note: we use Is_Volatile here rather than Treat_As_Volatile,
2004 -- because this is the enforcement of a language rule that applies
2005 -- only to "real" volatile variables, not e.g. to the address
2006 -- clause overlay case.
2008 elsif Is_Entity_Name
(Actual
)
2009 and then Is_Volatile
(Entity
(Actual
))
2010 and then not Is_By_Reference_Type
(E_Actual
)
2011 and then not Is_Scalar_Type
(Etype
(Entity
(Actual
)))
2012 and then not Is_Volatile
(E_Formal
)
2014 Add_Call_By_Copy_Code
;
2016 elsif Nkind
(Actual
) = N_Indexed_Component
2017 and then Is_Entity_Name
(Prefix
(Actual
))
2018 and then Has_Volatile_Components
(Entity
(Prefix
(Actual
)))
2020 Add_Call_By_Copy_Code
;
2022 -- Add call-by-copy code for the case of scalar out parameters
2023 -- when it is not known at compile time that the subtype of the
2024 -- formal is a subrange of the subtype of the actual (or vice
2025 -- versa for in out parameters), in order to get range checks
2026 -- on such actuals. (Maybe this case should be handled earlier
2027 -- in the if statement???)
2029 elsif Is_Scalar_Type
(E_Formal
)
2031 (not In_Subrange_Of
(E_Formal
, E_Actual
)
2033 (Ekind
(Formal
) = E_In_Out_Parameter
2034 and then not In_Subrange_Of
(E_Actual
, E_Formal
)))
2036 -- Perhaps the setting back to False should be done within
2037 -- Add_Call_By_Copy_Code, since it could get set on other
2038 -- cases occurring above???
2040 if Do_Range_Check
(Actual
) then
2041 Set_Do_Range_Check
(Actual
, False);
2044 Add_Call_By_Copy_Code
;
2047 -- RM 3.2.4 (23/3): A predicate is checked on in-out and out
2048 -- by-reference parameters on exit from the call. If the actual
2049 -- is a derived type and the operation is inherited, the body
2050 -- of the operation will not contain a call to the predicate
2051 -- function, so it must be done explicitly after the call. Ditto
2052 -- if the actual is an entity of a predicated subtype.
2054 -- The rule refers to by-reference types, but a check is needed
2055 -- for by-copy types as well. That check is subsumed by the rule
2056 -- for subtype conversion on assignment, but we can generate the
2057 -- required check now.
2059 -- Note also that Subp may be either a subprogram entity for
2060 -- direct calls, or a type entity for indirect calls, which must
2061 -- be handled separately because the name does not denote an
2062 -- overloadable entity.
2064 By_Ref_Predicate_Check
: declare
2065 Aund
: constant Entity_Id
:= Underlying_Type
(E_Actual
);
2068 function Is_Public_Subp
return Boolean;
2069 -- Check whether the subprogram being called is a visible
2070 -- operation of the type of the actual. Used to determine
2071 -- whether an invariant check must be generated on the
2074 ---------------------
2075 -- Is_Public_Subp --
2076 ---------------------
2078 function Is_Public_Subp
return Boolean is
2079 Pack
: constant Entity_Id
:= Scope
(Subp
);
2080 Subp_Decl
: Node_Id
;
2083 if not Is_Subprogram
(Subp
) then
2086 -- The operation may be inherited, or a primitive of the
2090 Nkind_In
(Parent
(Subp
), N_Private_Extension_Declaration
,
2091 N_Full_Type_Declaration
)
2093 Subp_Decl
:= Parent
(Subp
);
2096 Subp_Decl
:= Unit_Declaration_Node
(Subp
);
2099 return Ekind
(Pack
) = E_Package
2101 List_Containing
(Subp_Decl
) =
2102 Visible_Declarations
2103 (Specification
(Unit_Declaration_Node
(Pack
)));
2106 -- Start of processing for By_Ref_Predicate_Check
2115 if Has_Predicates
(Atyp
)
2116 and then Present
(Predicate_Function
(Atyp
))
2118 -- Skip predicate checks for special cases
2120 and then Predicate_Tests_On_Arguments
(Subp
)
2122 Append_To
(Post_Call
,
2123 Make_Predicate_Check
(Atyp
, Actual
));
2126 -- We generated caller-side invariant checks in two cases:
2128 -- a) when calling an inherited operation, where there is an
2129 -- implicit view conversion of the actual to the parent type.
2131 -- b) When the conversion is explicit
2133 -- We treat these cases separately because the required
2134 -- conversion for a) is added later when expanding the call.
2136 if Has_Invariants
(Etype
(Actual
))
2138 Nkind
(Parent
(Subp
)) = N_Private_Extension_Declaration
2140 if Comes_From_Source
(N
) and then Is_Public_Subp
then
2141 Append_To
(Post_Call
, Make_Invariant_Call
(Actual
));
2144 elsif Nkind
(Actual
) = N_Type_Conversion
2145 and then Has_Invariants
(Etype
(Expression
(Actual
)))
2147 if Comes_From_Source
(N
) and then Is_Public_Subp
then
2148 Append_To
(Post_Call
,
2149 Make_Invariant_Call
(Expression
(Actual
)));
2152 end By_Ref_Predicate_Check
;
2154 -- Processing for IN parameters
2157 -- For IN parameters in the bit-packed array case, we expand an
2158 -- indexed component (the circuit in Exp_Ch4 deliberately left
2159 -- indexed components appearing as actuals untouched, so that
2160 -- the special processing above for the OUT and IN OUT cases
2161 -- could be performed. We could make the test in Exp_Ch4 more
2162 -- complex and have it detect the parameter mode, but it is
2163 -- easier simply to handle all cases here.)
2165 if Nkind
(Actual
) = N_Indexed_Component
2166 and then Is_Bit_Packed_Array
(Etype
(Prefix
(Actual
)))
2168 Reset_Packed_Prefix
;
2169 Expand_Packed_Element_Reference
(Actual
);
2171 -- If we have a reference to a bit-packed array, we copy it, since
2172 -- the actual must be byte aligned.
2174 -- Is this really necessary in all cases???
2176 elsif Is_Ref_To_Bit_Packed_Array
(Actual
) then
2177 Add_Simple_Call_By_Copy_Code
;
2179 -- If a non-scalar actual is possibly unaligned, we need a copy
2181 elsif Is_Possibly_Unaligned_Object
(Actual
)
2182 and then not Represented_As_Scalar
(Etype
(Formal
))
2184 Add_Simple_Call_By_Copy_Code
;
2186 -- Similarly, we have to expand slices of packed arrays here
2187 -- because the result must be byte aligned.
2189 elsif Is_Ref_To_Bit_Packed_Slice
(Actual
) then
2190 Add_Call_By_Copy_Code
;
2192 -- Only processing remaining is to pass by copy if this is a
2193 -- reference to a possibly unaligned slice, since the caller
2194 -- expects an appropriately aligned argument.
2196 elsif Is_Possibly_Unaligned_Slice
(Actual
) then
2197 Add_Call_By_Copy_Code
;
2199 -- An unusual case: a current instance of an enclosing task can be
2200 -- an actual, and must be replaced by a reference to self.
2202 elsif Is_Entity_Name
(Actual
)
2203 and then Is_Task_Type
(Entity
(Actual
))
2205 if In_Open_Scopes
(Entity
(Actual
)) then
2207 (Make_Function_Call
(Loc
,
2208 Name
=> New_Occurrence_Of
(RTE
(RE_Self
), Loc
))));
2211 -- A task type cannot otherwise appear as an actual
2214 raise Program_Error
;
2219 Next_Formal
(Formal
);
2220 Next_Actual
(Actual
);
2228 procedure Expand_Call
(N
: Node_Id
) is
2229 Post_Call
: List_Id
;
2231 Expand_Call_Helper
(N
, Post_Call
);
2232 Insert_Post_Call_Actions
(N
, Post_Call
);
2235 ------------------------
2236 -- Expand_Call_Helper --
2237 ------------------------
2239 -- This procedure handles expansion of function calls and procedure call
2240 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
2241 -- Expand_N_Procedure_Call_Statement). Processing for calls includes:
2243 -- Replace call to Raise_Exception by Raise_Exception_Always if possible
2244 -- Provide values of actuals for all formals in Extra_Formals list
2245 -- Replace "call" to enumeration literal function by literal itself
2246 -- Rewrite call to predefined operator as operator
2247 -- Replace actuals to in-out parameters that are numeric conversions,
2248 -- with explicit assignment to temporaries before and after the call.
2250 -- Note that the list of actuals has been filled with default expressions
2251 -- during semantic analysis of the call. Only the extra actuals required
2252 -- for the 'Constrained attribute and for accessibility checks are added
2255 procedure Expand_Call_Helper
(N
: Node_Id
; Post_Call
: out List_Id
) is
2256 Loc
: constant Source_Ptr
:= Sloc
(N
);
2257 Call_Node
: Node_Id
:= N
;
2258 Extra_Actuals
: List_Id
:= No_List
;
2259 Prev
: Node_Id
:= Empty
;
2261 procedure Add_Actual_Parameter
(Insert_Param
: Node_Id
);
2262 -- Adds one entry to the end of the actual parameter list. Used for
2263 -- default parameters and for extra actuals (for Extra_Formals). The
2264 -- argument is an N_Parameter_Association node.
2266 procedure Add_Extra_Actual
(Expr
: Node_Id
; EF
: Entity_Id
);
2267 -- Adds an extra actual to the list of extra actuals. Expr is the
2268 -- expression for the value of the actual, EF is the entity for the
2271 procedure Add_View_Conversion_Invariants
2272 (Formal
: Entity_Id
;
2274 -- Adds invariant checks for every intermediate type between the range
2275 -- of a view converted argument to its ancestor (from parent to child).
2277 function Inherited_From_Formal
(S
: Entity_Id
) return Entity_Id
;
2278 -- Within an instance, a type derived from an untagged formal derived
2279 -- type inherits from the original parent, not from the actual. The
2280 -- current derivation mechanism has the derived type inherit from the
2281 -- actual, which is only correct outside of the instance. If the
2282 -- subprogram is inherited, we test for this particular case through a
2283 -- convoluted tree traversal before setting the proper subprogram to be
2286 function In_Unfrozen_Instance
(E
: Entity_Id
) return Boolean;
2287 -- Return true if E comes from an instance that is not yet frozen
2289 function Is_Direct_Deep_Call
(Subp
: Entity_Id
) return Boolean;
2290 -- Determine if Subp denotes a non-dispatching call to a Deep routine
2292 function New_Value
(From
: Node_Id
) return Node_Id
;
2293 -- From is the original Expression. New_Value is equivalent to a call
2294 -- to Duplicate_Subexpr with an explicit dereference when From is an
2295 -- access parameter.
2297 --------------------------
2298 -- Add_Actual_Parameter --
2299 --------------------------
2301 procedure Add_Actual_Parameter
(Insert_Param
: Node_Id
) is
2302 Actual_Expr
: constant Node_Id
:=
2303 Explicit_Actual_Parameter
(Insert_Param
);
2306 -- Case of insertion is first named actual
2308 if No
(Prev
) or else
2309 Nkind
(Parent
(Prev
)) /= N_Parameter_Association
2311 Set_Next_Named_Actual
2312 (Insert_Param
, First_Named_Actual
(Call_Node
));
2313 Set_First_Named_Actual
(Call_Node
, Actual_Expr
);
2316 if No
(Parameter_Associations
(Call_Node
)) then
2317 Set_Parameter_Associations
(Call_Node
, New_List
);
2320 Append
(Insert_Param
, Parameter_Associations
(Call_Node
));
2323 Insert_After
(Prev
, Insert_Param
);
2326 -- Case of insertion is not first named actual
2329 Set_Next_Named_Actual
2330 (Insert_Param
, Next_Named_Actual
(Parent
(Prev
)));
2331 Set_Next_Named_Actual
(Parent
(Prev
), Actual_Expr
);
2332 Append
(Insert_Param
, Parameter_Associations
(Call_Node
));
2335 Prev
:= Actual_Expr
;
2336 end Add_Actual_Parameter
;
2338 ----------------------
2339 -- Add_Extra_Actual --
2340 ----------------------
2342 procedure Add_Extra_Actual
(Expr
: Node_Id
; EF
: Entity_Id
) is
2343 Loc
: constant Source_Ptr
:= Sloc
(Expr
);
2346 if Extra_Actuals
= No_List
then
2347 Extra_Actuals
:= New_List
;
2348 Set_Parent
(Extra_Actuals
, Call_Node
);
2351 Append_To
(Extra_Actuals
,
2352 Make_Parameter_Association
(Loc
,
2353 Selector_Name
=> New_Occurrence_Of
(EF
, Loc
),
2354 Explicit_Actual_Parameter
=> Expr
));
2356 Analyze_And_Resolve
(Expr
, Etype
(EF
));
2358 if Nkind
(Call_Node
) = N_Function_Call
then
2359 Set_Is_Accessibility_Actual
(Parent
(Expr
));
2361 end Add_Extra_Actual
;
2363 ------------------------------------
2364 -- Add_View_Conversion_Invariants --
2365 ------------------------------------
2367 procedure Add_View_Conversion_Invariants
2368 (Formal
: Entity_Id
;
2372 Curr_Typ
: Entity_Id
;
2373 Inv_Checks
: List_Id
;
2374 Par_Typ
: Entity_Id
;
2377 Inv_Checks
:= No_List
;
2379 -- Extract the argument from a potentially nested set of view
2383 while Nkind
(Arg
) = N_Type_Conversion
loop
2384 Arg
:= Expression
(Arg
);
2387 -- Move up the derivation chain starting with the type of the formal
2388 -- parameter down to the type of the actual object.
2391 Par_Typ
:= Etype
(Arg
);
2392 while Par_Typ
/= Etype
(Formal
) and Par_Typ
/= Curr_Typ
loop
2393 Curr_Typ
:= Par_Typ
;
2395 if Has_Invariants
(Curr_Typ
)
2396 and then Present
(Invariant_Procedure
(Curr_Typ
))
2398 -- Verify the invariate of the current type. Generate:
2400 -- <Curr_Typ>Invariant (Curr_Typ (Arg));
2402 Prepend_New_To
(Inv_Checks
,
2403 Make_Procedure_Call_Statement
(Loc
,
2406 (Invariant_Procedure
(Curr_Typ
), Loc
),
2407 Parameter_Associations
=> New_List
(
2408 Make_Type_Conversion
(Loc
,
2409 Subtype_Mark
=> New_Occurrence_Of
(Curr_Typ
, Loc
),
2410 Expression
=> New_Copy_Tree
(Arg
)))));
2413 Par_Typ
:= Base_Type
(Etype
(Curr_Typ
));
2416 if not Is_Empty_List
(Inv_Checks
) then
2417 Insert_Actions_After
(N
, Inv_Checks
);
2419 end Add_View_Conversion_Invariants
;
2421 ---------------------------
2422 -- Inherited_From_Formal --
2423 ---------------------------
2425 function Inherited_From_Formal
(S
: Entity_Id
) return Entity_Id
is
2427 Gen_Par
: Entity_Id
;
2428 Gen_Prim
: Elist_Id
;
2433 -- If the operation is inherited, it is attached to the corresponding
2434 -- type derivation. If the parent in the derivation is a generic
2435 -- actual, it is a subtype of the actual, and we have to recover the
2436 -- original derived type declaration to find the proper parent.
2438 if Nkind
(Parent
(S
)) /= N_Full_Type_Declaration
2439 or else not Is_Derived_Type
(Defining_Identifier
(Parent
(S
)))
2440 or else Nkind
(Type_Definition
(Original_Node
(Parent
(S
)))) /=
2441 N_Derived_Type_Definition
2442 or else not In_Instance
2449 (Type_Definition
(Original_Node
(Parent
(S
))));
2451 if Nkind
(Indic
) = N_Subtype_Indication
then
2452 Par
:= Entity
(Subtype_Mark
(Indic
));
2454 Par
:= Entity
(Indic
);
2458 if not Is_Generic_Actual_Type
(Par
)
2459 or else Is_Tagged_Type
(Par
)
2460 or else Nkind
(Parent
(Par
)) /= N_Subtype_Declaration
2461 or else not In_Open_Scopes
(Scope
(Par
))
2465 Gen_Par
:= Generic_Parent_Type
(Parent
(Par
));
2468 -- If the actual has no generic parent type, the formal is not
2469 -- a formal derived type, so nothing to inherit.
2471 if No
(Gen_Par
) then
2475 -- If the generic parent type is still the generic type, this is a
2476 -- private formal, not a derived formal, and there are no operations
2477 -- inherited from the formal.
2479 if Nkind
(Parent
(Gen_Par
)) = N_Formal_Type_Declaration
then
2483 Gen_Prim
:= Collect_Primitive_Operations
(Gen_Par
);
2485 Elmt
:= First_Elmt
(Gen_Prim
);
2486 while Present
(Elmt
) loop
2487 if Chars
(Node
(Elmt
)) = Chars
(S
) then
2493 F1
:= First_Formal
(S
);
2494 F2
:= First_Formal
(Node
(Elmt
));
2496 and then Present
(F2
)
2498 if Etype
(F1
) = Etype
(F2
)
2499 or else Etype
(F2
) = Gen_Par
2505 exit; -- not the right subprogram
2517 raise Program_Error
;
2518 end Inherited_From_Formal
;
2520 --------------------------
2521 -- In_Unfrozen_Instance --
2522 --------------------------
2524 function In_Unfrozen_Instance
(E
: Entity_Id
) return Boolean is
2529 while Present
(S
) and then S
/= Standard_Standard
loop
2530 if Is_Generic_Instance
(S
)
2531 and then Present
(Freeze_Node
(S
))
2532 and then not Analyzed
(Freeze_Node
(S
))
2541 end In_Unfrozen_Instance
;
2543 -------------------------
2544 -- Is_Direct_Deep_Call --
2545 -------------------------
2547 function Is_Direct_Deep_Call
(Subp
: Entity_Id
) return Boolean is
2549 if Is_TSS
(Subp
, TSS_Deep_Adjust
)
2550 or else Is_TSS
(Subp
, TSS_Deep_Finalize
)
2551 or else Is_TSS
(Subp
, TSS_Deep_Initialize
)
2558 Actual
:= First
(Parameter_Associations
(N
));
2559 Formal
:= First_Formal
(Subp
);
2560 while Present
(Actual
)
2561 and then Present
(Formal
)
2563 if Nkind
(Actual
) = N_Identifier
2564 and then Is_Controlling_Actual
(Actual
)
2565 and then Etype
(Actual
) = Etype
(Formal
)
2571 Next_Formal
(Formal
);
2577 end Is_Direct_Deep_Call
;
2583 function New_Value
(From
: Node_Id
) return Node_Id
is
2584 Res
: constant Node_Id
:= Duplicate_Subexpr
(From
);
2586 if Is_Access_Type
(Etype
(From
)) then
2587 return Make_Explicit_Dereference
(Sloc
(From
), Prefix
=> Res
);
2595 Remote
: constant Boolean := Is_Remote_Call
(Call_Node
);
2598 Orig_Subp
: Entity_Id
:= Empty
;
2599 Param_Count
: Natural := 0;
2600 Parent_Formal
: Entity_Id
;
2601 Parent_Subp
: Entity_Id
;
2605 Prev_Orig
: Node_Id
;
2606 -- Original node for an actual, which may have been rewritten. If the
2607 -- actual is a function call that has been transformed from a selected
2608 -- component, the original node is unanalyzed. Otherwise, it carries
2609 -- semantic information used to generate additional actuals.
2611 CW_Interface_Formals_Present
: Boolean := False;
2613 -- Start of processing for Expand_Call_Helper
2616 Post_Call
:= New_List
;
2618 -- Expand the function or procedure call if the first actual has a
2619 -- declared dimension aspect, and the subprogram is declared in one
2620 -- of the dimension I/O packages.
2622 if Ada_Version
>= Ada_2012
2624 Nkind_In
(Call_Node
, N_Procedure_Call_Statement
, N_Function_Call
)
2625 and then Present
(Parameter_Associations
(Call_Node
))
2627 Expand_Put_Call_With_Symbol
(Call_Node
);
2630 -- Ignore if previous error
2632 if Nkind
(Call_Node
) in N_Has_Etype
2633 and then Etype
(Call_Node
) = Any_Type
2638 -- Call using access to subprogram with explicit dereference
2640 if Nkind
(Name
(Call_Node
)) = N_Explicit_Dereference
then
2641 Subp
:= Etype
(Name
(Call_Node
));
2642 Parent_Subp
:= Empty
;
2644 -- Case of call to simple entry, where the Name is a selected component
2645 -- whose prefix is the task, and whose selector name is the entry name
2647 elsif Nkind
(Name
(Call_Node
)) = N_Selected_Component
then
2648 Subp
:= Entity
(Selector_Name
(Name
(Call_Node
)));
2649 Parent_Subp
:= Empty
;
2651 -- Case of call to member of entry family, where Name is an indexed
2652 -- component, with the prefix being a selected component giving the
2653 -- task and entry family name, and the index being the entry index.
2655 elsif Nkind
(Name
(Call_Node
)) = N_Indexed_Component
then
2656 Subp
:= Entity
(Selector_Name
(Prefix
(Name
(Call_Node
))));
2657 Parent_Subp
:= Empty
;
2662 Subp
:= Entity
(Name
(Call_Node
));
2663 Parent_Subp
:= Alias
(Subp
);
2665 -- Replace call to Raise_Exception by call to Raise_Exception_Always
2666 -- if we can tell that the first parameter cannot possibly be null.
2667 -- This improves efficiency by avoiding a run-time test.
2669 -- We do not do this if Raise_Exception_Always does not exist, which
2670 -- can happen in configurable run time profiles which provide only a
2673 if Is_RTE
(Subp
, RE_Raise_Exception
)
2674 and then RTE_Available
(RE_Raise_Exception_Always
)
2677 FA
: constant Node_Id
:=
2678 Original_Node
(First_Actual
(Call_Node
));
2681 -- The case we catch is where the first argument is obtained
2682 -- using the Identity attribute (which must always be
2685 if Nkind
(FA
) = N_Attribute_Reference
2686 and then Attribute_Name
(FA
) = Name_Identity
2688 Subp
:= RTE
(RE_Raise_Exception_Always
);
2689 Set_Name
(Call_Node
, New_Occurrence_Of
(Subp
, Loc
));
2694 if Ekind
(Subp
) = E_Entry
then
2695 Parent_Subp
:= Empty
;
2699 -- Ada 2005 (AI-345): We have a procedure call as a triggering
2700 -- alternative in an asynchronous select or as an entry call in
2701 -- a conditional or timed select. Check whether the procedure call
2702 -- is a renaming of an entry and rewrite it as an entry call.
2704 if Ada_Version
>= Ada_2005
2705 and then Nkind
(Call_Node
) = N_Procedure_Call_Statement
2707 ((Nkind
(Parent
(Call_Node
)) = N_Triggering_Alternative
2708 and then Triggering_Statement
(Parent
(Call_Node
)) = Call_Node
)
2710 (Nkind
(Parent
(Call_Node
)) = N_Entry_Call_Alternative
2711 and then Entry_Call_Statement
(Parent
(Call_Node
)) = Call_Node
))
2715 Ren_Root
: Entity_Id
:= Subp
;
2718 -- This may be a chain of renamings, find the root
2720 if Present
(Alias
(Ren_Root
)) then
2721 Ren_Root
:= Alias
(Ren_Root
);
2724 if Present
(Original_Node
(Parent
(Parent
(Ren_Root
)))) then
2725 Ren_Decl
:= Original_Node
(Parent
(Parent
(Ren_Root
)));
2727 if Nkind
(Ren_Decl
) = N_Subprogram_Renaming_Declaration
then
2729 Make_Entry_Call_Statement
(Loc
,
2731 New_Copy_Tree
(Name
(Ren_Decl
)),
2732 Parameter_Associations
=>
2734 (Parameter_Associations
(Call_Node
))));
2742 -- When generating C code, transform a function call that returns a
2743 -- constrained array type into procedure form.
2745 if Modify_Tree_For_C
2746 and then Nkind
(Call_Node
) = N_Function_Call
2747 and then Is_Entity_Name
(Name
(Call_Node
))
2748 and then Rewritten_For_C
(Ultimate_Alias
(Entity
(Name
(Call_Node
))))
2750 -- For internally generated calls ensure that they reference the
2751 -- entity of the spec of the called function (needed since the
2752 -- expander may generate calls using the entity of their body).
2753 -- See for example Expand_Boolean_Operator().
2755 if not (Comes_From_Source
(Call_Node
))
2756 and then Nkind
(Unit_Declaration_Node
2757 (Ultimate_Alias
(Entity
(Name
(Call_Node
))))) =
2760 Set_Entity
(Name
(Call_Node
),
2761 Corresponding_Function
2762 (Corresponding_Procedure
2763 (Ultimate_Alias
(Entity
(Name
(Call_Node
))))));
2766 Rewrite_Function_Call_For_C
(Call_Node
);
2770 -- First step, compute extra actuals, corresponding to any Extra_Formals
2771 -- present. Note that we do not access Extra_Formals directly, instead
2772 -- we simply note the presence of the extra formals as we process the
2773 -- regular formals collecting corresponding actuals in Extra_Actuals.
2775 -- We also generate any required range checks for actuals for in formals
2776 -- as we go through the loop, since this is a convenient place to do it.
2777 -- (Though it seems that this would be better done in Expand_Actuals???)
2779 -- Special case: Thunks must not compute the extra actuals; they must
2780 -- just propagate to the target primitive their extra actuals.
2782 if Is_Thunk
(Current_Scope
)
2783 and then Thunk_Entity
(Current_Scope
) = Subp
2784 and then Present
(Extra_Formals
(Subp
))
2786 pragma Assert
(Present
(Extra_Formals
(Current_Scope
)));
2789 Target_Formal
: Entity_Id
;
2790 Thunk_Formal
: Entity_Id
;
2793 Target_Formal
:= Extra_Formals
(Subp
);
2794 Thunk_Formal
:= Extra_Formals
(Current_Scope
);
2795 while Present
(Target_Formal
) loop
2797 (New_Occurrence_Of
(Thunk_Formal
, Loc
), Thunk_Formal
);
2799 Target_Formal
:= Extra_Formal
(Target_Formal
);
2800 Thunk_Formal
:= Extra_Formal
(Thunk_Formal
);
2803 while Is_Non_Empty_List
(Extra_Actuals
) loop
2804 Add_Actual_Parameter
(Remove_Head
(Extra_Actuals
));
2807 Expand_Actuals
(Call_Node
, Subp
, Post_Call
);
2808 pragma Assert
(Is_Empty_List
(Post_Call
));
2813 Formal
:= First_Formal
(Subp
);
2814 Actual
:= First_Actual
(Call_Node
);
2816 while Present
(Formal
) loop
2818 -- Generate range check if required
2820 if Do_Range_Check
(Actual
)
2821 and then Ekind
(Formal
) = E_In_Parameter
2823 Generate_Range_Check
2824 (Actual
, Etype
(Formal
), CE_Range_Check_Failed
);
2827 -- Prepare to examine current entry
2830 Prev_Orig
:= Original_Node
(Prev
);
2832 -- Ada 2005 (AI-251): Check if any formal is a class-wide interface
2833 -- to expand it in a further round.
2835 CW_Interface_Formals_Present
:=
2836 CW_Interface_Formals_Present
2838 (Is_Class_Wide_Type
(Etype
(Formal
))
2839 and then Is_Interface
(Etype
(Etype
(Formal
))))
2841 (Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
2842 and then Is_Class_Wide_Type
(Directly_Designated_Type
2843 (Etype
(Etype
(Formal
))))
2844 and then Is_Interface
(Directly_Designated_Type
2845 (Etype
(Etype
(Formal
)))));
2847 -- Create possible extra actual for constrained case. Usually, the
2848 -- extra actual is of the form actual'constrained, but since this
2849 -- attribute is only available for unconstrained records, TRUE is
2850 -- expanded if the type of the formal happens to be constrained (for
2851 -- instance when this procedure is inherited from an unconstrained
2852 -- record to a constrained one) or if the actual has no discriminant
2853 -- (its type is constrained). An exception to this is the case of a
2854 -- private type without discriminants. In this case we pass FALSE
2855 -- because the object has underlying discriminants with defaults.
2857 if Present
(Extra_Constrained
(Formal
)) then
2858 if Ekind
(Etype
(Prev
)) in Private_Kind
2859 and then not Has_Discriminants
(Base_Type
(Etype
(Prev
)))
2862 (New_Occurrence_Of
(Standard_False
, Loc
),
2863 Extra_Constrained
(Formal
));
2865 elsif Is_Constrained
(Etype
(Formal
))
2866 or else not Has_Discriminants
(Etype
(Prev
))
2869 (New_Occurrence_Of
(Standard_True
, Loc
),
2870 Extra_Constrained
(Formal
));
2872 -- Do not produce extra actuals for Unchecked_Union parameters.
2873 -- Jump directly to the end of the loop.
2875 elsif Is_Unchecked_Union
(Base_Type
(Etype
(Actual
))) then
2876 goto Skip_Extra_Actual_Generation
;
2879 -- If the actual is a type conversion, then the constrained
2880 -- test applies to the actual, not the target type.
2886 -- Test for unchecked conversions as well, which can occur
2887 -- as out parameter actuals on calls to stream procedures.
2890 while Nkind_In
(Act_Prev
, N_Type_Conversion
,
2891 N_Unchecked_Type_Conversion
)
2893 Act_Prev
:= Expression
(Act_Prev
);
2896 -- If the expression is a conversion of a dereference, this
2897 -- is internally generated code that manipulates addresses,
2898 -- e.g. when building interface tables. No check should
2899 -- occur in this case, and the discriminated object is not
2902 if not Comes_From_Source
(Actual
)
2903 and then Nkind
(Actual
) = N_Unchecked_Type_Conversion
2904 and then Nkind
(Act_Prev
) = N_Explicit_Dereference
2907 (New_Occurrence_Of
(Standard_False
, Loc
),
2908 Extra_Constrained
(Formal
));
2912 (Make_Attribute_Reference
(Sloc
(Prev
),
2914 Duplicate_Subexpr_No_Checks
2915 (Act_Prev
, Name_Req
=> True),
2916 Attribute_Name
=> Name_Constrained
),
2917 Extra_Constrained
(Formal
));
2923 -- Create possible extra actual for accessibility level
2925 if Present
(Extra_Accessibility
(Formal
)) then
2927 -- Ada 2005 (AI-252): If the actual was rewritten as an Access
2928 -- attribute, then the original actual may be an aliased object
2929 -- occurring as the prefix in a call using "Object.Operation"
2930 -- notation. In that case we must pass the level of the object,
2931 -- so Prev_Orig is reset to Prev and the attribute will be
2932 -- processed by the code for Access attributes further below.
2934 if Prev_Orig
/= Prev
2935 and then Nkind
(Prev
) = N_Attribute_Reference
2937 Get_Attribute_Id
(Attribute_Name
(Prev
)) = Attribute_Access
2938 and then Is_Aliased_View
(Prev_Orig
)
2942 -- If the actual is a formal of an enclosing subprogram it is
2943 -- the right entity, even if it is a rewriting. This happens
2944 -- when the call is within an inherited condition or predicate.
2946 elsif Is_Entity_Name
(Actual
)
2947 and then Is_Formal
(Entity
(Actual
))
2948 and then In_Open_Scopes
(Scope
(Entity
(Actual
)))
2953 -- Ada 2005 (AI-251): Thunks must propagate the extra actuals of
2954 -- accessibility levels.
2956 if Is_Thunk
(Current_Scope
) then
2958 Parm_Ent
: Entity_Id
;
2961 if Is_Controlling_Actual
(Actual
) then
2963 -- Find the corresponding actual of the thunk
2965 Parm_Ent
:= First_Entity
(Current_Scope
);
2966 for J
in 2 .. Param_Count
loop
2967 Next_Entity
(Parm_Ent
);
2970 -- Handle unchecked conversion of access types generated
2971 -- in thunks (cf. Expand_Interface_Thunk).
2973 elsif Is_Access_Type
(Etype
(Actual
))
2974 and then Nkind
(Actual
) = N_Unchecked_Type_Conversion
2976 Parm_Ent
:= Entity
(Expression
(Actual
));
2978 else pragma Assert
(Is_Entity_Name
(Actual
));
2979 Parm_Ent
:= Entity
(Actual
);
2983 (New_Occurrence_Of
(Extra_Accessibility
(Parm_Ent
), Loc
),
2984 Extra_Accessibility
(Formal
));
2987 elsif Is_Entity_Name
(Prev_Orig
) then
2989 -- When passing an access parameter, or a renaming of an access
2990 -- parameter, as the actual to another access parameter we need
2991 -- to pass along the actual's own access level parameter. This
2992 -- is done if we are within the scope of the formal access
2993 -- parameter (if this is an inlined body the extra formal is
2996 if (Is_Formal
(Entity
(Prev_Orig
))
2998 (Present
(Renamed_Object
(Entity
(Prev_Orig
)))
3000 Is_Entity_Name
(Renamed_Object
(Entity
(Prev_Orig
)))
3003 (Entity
(Renamed_Object
(Entity
(Prev_Orig
))))))
3004 and then Ekind
(Etype
(Prev_Orig
)) = E_Anonymous_Access_Type
3005 and then In_Open_Scopes
(Scope
(Entity
(Prev_Orig
)))
3008 Parm_Ent
: constant Entity_Id
:= Param_Entity
(Prev_Orig
);
3011 pragma Assert
(Present
(Parm_Ent
));
3013 if Present
(Extra_Accessibility
(Parm_Ent
)) then
3016 (Extra_Accessibility
(Parm_Ent
), Loc
),
3017 Extra_Accessibility
(Formal
));
3019 -- If the actual access parameter does not have an
3020 -- associated extra formal providing its scope level,
3021 -- then treat the actual as having library-level
3026 (Make_Integer_Literal
(Loc
,
3027 Intval
=> Scope_Depth
(Standard_Standard
)),
3028 Extra_Accessibility
(Formal
));
3032 -- The actual is a normal access value, so just pass the level
3033 -- of the actual's access type.
3037 (Dynamic_Accessibility_Level
(Prev_Orig
),
3038 Extra_Accessibility
(Formal
));
3041 -- If the actual is an access discriminant, then pass the level
3042 -- of the enclosing object (RM05-3.10.2(12.4/2)).
3044 elsif Nkind
(Prev_Orig
) = N_Selected_Component
3045 and then Ekind
(Entity
(Selector_Name
(Prev_Orig
))) =
3047 and then Ekind
(Etype
(Entity
(Selector_Name
(Prev_Orig
)))) =
3048 E_Anonymous_Access_Type
3051 (Make_Integer_Literal
(Loc
,
3052 Intval
=> Object_Access_Level
(Prefix
(Prev_Orig
))),
3053 Extra_Accessibility
(Formal
));
3058 case Nkind
(Prev_Orig
) is
3059 when N_Attribute_Reference
=>
3060 case Get_Attribute_Id
(Attribute_Name
(Prev_Orig
)) is
3062 -- For X'Access, pass on the level of the prefix X
3064 when Attribute_Access
=>
3066 -- If this is an Access attribute applied to the
3067 -- the current instance object passed to a type
3068 -- initialization procedure, then use the level
3069 -- of the type itself. This is not really correct,
3070 -- as there should be an extra level parameter
3071 -- passed in with _init formals (only in the case
3072 -- where the type is immutably limited), but we
3073 -- don't have an easy way currently to create such
3074 -- an extra formal (init procs aren't ever frozen).
3075 -- For now we just use the level of the type,
3076 -- which may be too shallow, but that works better
3077 -- than passing Object_Access_Level of the type,
3078 -- which can be one level too deep in some cases.
3081 if Is_Entity_Name
(Prefix
(Prev_Orig
))
3082 and then Is_Type
(Entity
(Prefix
(Prev_Orig
)))
3085 (Make_Integer_Literal
(Loc
,
3088 (Entity
(Prefix
(Prev_Orig
)))),
3089 Extra_Accessibility
(Formal
));
3093 (Make_Integer_Literal
(Loc
,
3096 (Prefix
(Prev_Orig
))),
3097 Extra_Accessibility
(Formal
));
3100 -- Treat the unchecked attributes as library-level
3102 when Attribute_Unchecked_Access
3103 | Attribute_Unrestricted_Access
3106 (Make_Integer_Literal
(Loc
,
3107 Intval
=> Scope_Depth
(Standard_Standard
)),
3108 Extra_Accessibility
(Formal
));
3110 -- No other cases of attributes returning access
3111 -- values that can be passed to access parameters.
3114 raise Program_Error
;
3118 -- For allocators we pass the level of the execution of the
3119 -- called subprogram, which is one greater than the current
3124 (Make_Integer_Literal
(Loc
,
3125 Intval
=> Scope_Depth
(Current_Scope
) + 1),
3126 Extra_Accessibility
(Formal
));
3128 -- For most other cases we simply pass the level of the
3129 -- actual's access type. The type is retrieved from
3130 -- Prev rather than Prev_Orig, because in some cases
3131 -- Prev_Orig denotes an original expression that has
3132 -- not been analyzed.
3136 (Dynamic_Accessibility_Level
(Prev
),
3137 Extra_Accessibility
(Formal
));
3142 -- Perform the check of 4.6(49) that prevents a null value from being
3143 -- passed as an actual to an access parameter. Note that the check
3144 -- is elided in the common cases of passing an access attribute or
3145 -- access parameter as an actual. Also, we currently don't enforce
3146 -- this check for expander-generated actuals and when -gnatdj is set.
3148 if Ada_Version
>= Ada_2005
then
3150 -- Ada 2005 (AI-231): Check null-excluding access types. Note that
3151 -- the intent of 6.4.1(13) is that null-exclusion checks should
3152 -- not be done for 'out' parameters, even though it refers only
3153 -- to constraint checks, and a null_exclusion is not a constraint.
3154 -- Note that AI05-0196-1 corrects this mistake in the RM.
3156 if Is_Access_Type
(Etype
(Formal
))
3157 and then Can_Never_Be_Null
(Etype
(Formal
))
3158 and then Ekind
(Formal
) /= E_Out_Parameter
3159 and then Nkind
(Prev
) /= N_Raise_Constraint_Error
3160 and then (Known_Null
(Prev
)
3161 or else not Can_Never_Be_Null
(Etype
(Prev
)))
3163 Install_Null_Excluding_Check
(Prev
);
3166 -- Ada_Version < Ada_2005
3169 if Ekind
(Etype
(Formal
)) /= E_Anonymous_Access_Type
3170 or else Access_Checks_Suppressed
(Subp
)
3174 elsif Debug_Flag_J
then
3177 elsif not Comes_From_Source
(Prev
) then
3180 elsif Is_Entity_Name
(Prev
)
3181 and then Ekind
(Etype
(Prev
)) = E_Anonymous_Access_Type
3185 elsif Nkind_In
(Prev
, N_Allocator
, N_Attribute_Reference
) then
3189 Install_Null_Excluding_Check
(Prev
);
3193 -- Perform appropriate validity checks on parameters that
3196 if Validity_Checks_On
then
3197 if (Ekind
(Formal
) = E_In_Parameter
3198 and then Validity_Check_In_Params
)
3200 (Ekind
(Formal
) = E_In_Out_Parameter
3201 and then Validity_Check_In_Out_Params
)
3203 -- If the actual is an indexed component of a packed type (or
3204 -- is an indexed or selected component whose prefix recursively
3205 -- meets this condition), it has not been expanded yet. It will
3206 -- be copied in the validity code that follows, and has to be
3207 -- expanded appropriately, so reanalyze it.
3209 -- What we do is just to unset analyzed bits on prefixes till
3210 -- we reach something that does not have a prefix.
3217 while Nkind_In
(Nod
, N_Indexed_Component
,
3218 N_Selected_Component
)
3220 Set_Analyzed
(Nod
, False);
3221 Nod
:= Prefix
(Nod
);
3225 Ensure_Valid
(Actual
);
3229 -- For IN OUT and OUT parameters, ensure that subscripts are valid
3230 -- since this is a left side reference. We only do this for calls
3231 -- from the source program since we assume that compiler generated
3232 -- calls explicitly generate any required checks. We also need it
3233 -- only if we are doing standard validity checks, since clearly it is
3234 -- not needed if validity checks are off, and in subscript validity
3235 -- checking mode, all indexed components are checked with a call
3236 -- directly from Expand_N_Indexed_Component.
3238 if Comes_From_Source
(Call_Node
)
3239 and then Ekind
(Formal
) /= E_In_Parameter
3240 and then Validity_Checks_On
3241 and then Validity_Check_Default
3242 and then not Validity_Check_Subscripts
3244 Check_Valid_Lvalue_Subscripts
(Actual
);
3247 -- Mark any scalar OUT parameter that is a simple variable as no
3248 -- longer known to be valid (unless the type is always valid). This
3249 -- reflects the fact that if an OUT parameter is never set in a
3250 -- procedure, then it can become invalid on the procedure return.
3252 if Ekind
(Formal
) = E_Out_Parameter
3253 and then Is_Entity_Name
(Actual
)
3254 and then Ekind
(Entity
(Actual
)) = E_Variable
3255 and then not Is_Known_Valid
(Etype
(Actual
))
3257 Set_Is_Known_Valid
(Entity
(Actual
), False);
3260 -- For an OUT or IN OUT parameter, if the actual is an entity, then
3261 -- clear current values, since they can be clobbered. We are probably
3262 -- doing this in more places than we need to, but better safe than
3263 -- sorry when it comes to retaining bad current values.
3265 if Ekind
(Formal
) /= E_In_Parameter
3266 and then Is_Entity_Name
(Actual
)
3267 and then Present
(Entity
(Actual
))
3270 Ent
: constant Entity_Id
:= Entity
(Actual
);
3274 -- For an OUT or IN OUT parameter that is an assignable entity,
3275 -- we do not want to clobber the Last_Assignment field, since
3276 -- if it is set, it was precisely because it is indeed an OUT
3277 -- or IN OUT parameter. We do reset the Is_Known_Valid flag
3278 -- since the subprogram could have returned in invalid value.
3280 if Ekind_In
(Formal
, E_Out_Parameter
, E_In_Out_Parameter
)
3281 and then Is_Assignable
(Ent
)
3283 Sav
:= Last_Assignment
(Ent
);
3284 Kill_Current_Values
(Ent
);
3285 Set_Last_Assignment
(Ent
, Sav
);
3286 Set_Is_Known_Valid
(Ent
, False);
3288 -- For all other cases, just kill the current values
3291 Kill_Current_Values
(Ent
);
3296 -- If the formal is class wide and the actual is an aggregate, force
3297 -- evaluation so that the back end who does not know about class-wide
3298 -- type, does not generate a temporary of the wrong size.
3300 if not Is_Class_Wide_Type
(Etype
(Formal
)) then
3303 elsif Nkind
(Actual
) = N_Aggregate
3304 or else (Nkind
(Actual
) = N_Qualified_Expression
3305 and then Nkind
(Expression
(Actual
)) = N_Aggregate
)
3307 Force_Evaluation
(Actual
);
3310 -- In a remote call, if the formal is of a class-wide type, check
3311 -- that the actual meets the requirements described in E.4(18).
3313 if Remote
and then Is_Class_Wide_Type
(Etype
(Formal
)) then
3314 Insert_Action
(Actual
,
3315 Make_Transportable_Check
(Loc
,
3316 Duplicate_Subexpr_Move_Checks
(Actual
)));
3319 -- Perform invariant checks for all intermediate types in a view
3320 -- conversion after successful return from a call that passes the
3321 -- view conversion as an IN OUT or OUT parameter (RM 7.3.2 (12/3,
3322 -- 13/3, 14/3)). Consider only source conversion in order to avoid
3323 -- generating spurious checks on complex expansion such as object
3324 -- initialization through an extension aggregate.
3326 if Comes_From_Source
(N
)
3327 and then Ekind
(Formal
) /= E_In_Parameter
3328 and then Nkind
(Actual
) = N_Type_Conversion
3330 Add_View_Conversion_Invariants
(Formal
, Actual
);
3333 -- Generating C the initialization of an allocator is performed by
3334 -- means of individual statements, and hence it must be done before
3337 if Modify_Tree_For_C
3338 and then Nkind
(Actual
) = N_Allocator
3339 and then Nkind
(Expression
(Actual
)) = N_Qualified_Expression
3341 Remove_Side_Effects
(Actual
);
3344 -- This label is required when skipping extra actual generation for
3345 -- Unchecked_Union parameters.
3347 <<Skip_Extra_Actual_Generation
>>
3349 Param_Count
:= Param_Count
+ 1;
3350 Next_Actual
(Actual
);
3351 Next_Formal
(Formal
);
3354 -- If we are calling an Ada 2012 function which needs to have the
3355 -- "accessibility level determined by the point of call" (AI05-0234)
3356 -- passed in to it, then pass it in.
3358 if Ekind_In
(Subp
, E_Function
, E_Operator
, E_Subprogram_Type
)
3360 Present
(Extra_Accessibility_Of_Result
(Ultimate_Alias
(Subp
)))
3363 Ancestor
: Node_Id
:= Parent
(Call_Node
);
3364 Level
: Node_Id
:= Empty
;
3365 Defer
: Boolean := False;
3368 -- Unimplemented: if Subp returns an anonymous access type, then
3370 -- a) if the call is the operand of an explict conversion, then
3371 -- the target type of the conversion (a named access type)
3372 -- determines the accessibility level pass in;
3374 -- b) if the call defines an access discriminant of an object
3375 -- (e.g., the discriminant of an object being created by an
3376 -- allocator, or the discriminant of a function result),
3377 -- then the accessibility level to pass in is that of the
3378 -- discriminated object being initialized).
3382 while Nkind
(Ancestor
) = N_Qualified_Expression
3384 Ancestor
:= Parent
(Ancestor
);
3387 case Nkind
(Ancestor
) is
3390 -- At this point, we'd like to assign
3392 -- Level := Dynamic_Accessibility_Level (Ancestor);
3394 -- but Etype of Ancestor may not have been set yet,
3395 -- so that doesn't work.
3397 -- Handle this later in Expand_Allocator_Expression.
3401 when N_Object_Declaration
3402 | N_Object_Renaming_Declaration
3405 Def_Id
: constant Entity_Id
:=
3406 Defining_Identifier
(Ancestor
);
3409 if Is_Return_Object
(Def_Id
) then
3410 if Present
(Extra_Accessibility_Of_Result
3411 (Return_Applies_To
(Scope
(Def_Id
))))
3413 -- Pass along value that was passed in if the
3414 -- routine we are returning from also has an
3415 -- Accessibility_Of_Result formal.
3419 (Extra_Accessibility_Of_Result
3420 (Return_Applies_To
(Scope
(Def_Id
))), Loc
);
3424 Make_Integer_Literal
(Loc
,
3425 Intval
=> Object_Access_Level
(Def_Id
));
3429 when N_Simple_Return_Statement
=>
3430 if Present
(Extra_Accessibility_Of_Result
3432 (Return_Statement_Entity
(Ancestor
))))
3434 -- Pass along value that was passed in if the returned
3435 -- routine also has an Accessibility_Of_Result formal.
3439 (Extra_Accessibility_Of_Result
3441 (Return_Statement_Entity
(Ancestor
))), Loc
);
3449 if not Present
(Level
) then
3451 -- The "innermost master that evaluates the function call".
3453 -- ??? - Should we use Integer'Last here instead in order
3454 -- to deal with (some of) the problems associated with
3455 -- calls to subps whose enclosing scope is unknown (e.g.,
3456 -- Anon_Access_To_Subp_Param.all)?
3459 Make_Integer_Literal
(Loc
,
3460 Intval
=> Scope_Depth
(Current_Scope
) + 1);
3465 Extra_Accessibility_Of_Result
(Ultimate_Alias
(Subp
)));
3470 -- If we are expanding the RHS of an assignment we need to check if tag
3471 -- propagation is needed. You might expect this processing to be in
3472 -- Analyze_Assignment but has to be done earlier (bottom-up) because the
3473 -- assignment might be transformed to a declaration for an unconstrained
3474 -- value if the expression is classwide.
3476 if Nkind
(Call_Node
) = N_Function_Call
3477 and then Is_Tag_Indeterminate
(Call_Node
)
3478 and then Is_Entity_Name
(Name
(Call_Node
))
3481 Ass
: Node_Id
:= Empty
;
3484 if Nkind
(Parent
(Call_Node
)) = N_Assignment_Statement
then
3485 Ass
:= Parent
(Call_Node
);
3487 elsif Nkind
(Parent
(Call_Node
)) = N_Qualified_Expression
3488 and then Nkind
(Parent
(Parent
(Call_Node
))) =
3489 N_Assignment_Statement
3491 Ass
:= Parent
(Parent
(Call_Node
));
3493 elsif Nkind
(Parent
(Call_Node
)) = N_Explicit_Dereference
3494 and then Nkind
(Parent
(Parent
(Call_Node
))) =
3495 N_Assignment_Statement
3497 Ass
:= Parent
(Parent
(Call_Node
));
3501 and then Is_Class_Wide_Type
(Etype
(Name
(Ass
)))
3503 if Is_Access_Type
(Etype
(Call_Node
)) then
3504 if Designated_Type
(Etype
(Call_Node
)) /=
3505 Root_Type
(Etype
(Name
(Ass
)))
3508 ("tag-indeterminate expression "
3509 & " must have designated type& (RM 5.2 (6))",
3510 Call_Node
, Root_Type
(Etype
(Name
(Ass
))));
3512 Propagate_Tag
(Name
(Ass
), Call_Node
);
3515 elsif Etype
(Call_Node
) /= Root_Type
(Etype
(Name
(Ass
))) then
3517 ("tag-indeterminate expression must have type&"
3519 Call_Node
, Root_Type
(Etype
(Name
(Ass
))));
3522 Propagate_Tag
(Name
(Ass
), Call_Node
);
3525 -- The call will be rewritten as a dispatching call, and
3526 -- expanded as such.
3533 -- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
3534 -- it to point to the correct secondary virtual table
3536 if Nkind
(Call_Node
) in N_Subprogram_Call
3537 and then CW_Interface_Formals_Present
3539 Expand_Interface_Actuals
(Call_Node
);
3542 -- Deals with Dispatch_Call if we still have a call, before expanding
3543 -- extra actuals since this will be done on the re-analysis of the
3544 -- dispatching call. Note that we do not try to shorten the actual list
3545 -- for a dispatching call, it would not make sense to do so. Expansion
3546 -- of dispatching calls is suppressed for VM targets, because the VM
3547 -- back-ends directly handle the generation of dispatching calls and
3548 -- would have to undo any expansion to an indirect call.
3550 if Nkind
(Call_Node
) in N_Subprogram_Call
3551 and then Present
(Controlling_Argument
(Call_Node
))
3554 Call_Typ
: constant Entity_Id
:= Etype
(Call_Node
);
3555 Typ
: constant Entity_Id
:= Find_Dispatching_Type
(Subp
);
3556 Eq_Prim_Op
: Entity_Id
:= Empty
;
3559 Prev_Call
: Node_Id
;
3562 if not Is_Limited_Type
(Typ
) then
3563 Eq_Prim_Op
:= Find_Prim_Op
(Typ
, Name_Op_Eq
);
3566 if Tagged_Type_Expansion
then
3567 Expand_Dispatching_Call
(Call_Node
);
3569 -- The following return is worrisome. Is it really OK to skip
3570 -- all remaining processing in this procedure ???
3577 Apply_Tag_Checks
(Call_Node
);
3579 -- If this is a dispatching "=", we must first compare the
3580 -- tags so we generate: x.tag = y.tag and then x = y
3582 if Subp
= Eq_Prim_Op
then
3584 -- Mark the node as analyzed to avoid reanalyzing this
3585 -- dispatching call (which would cause a never-ending loop)
3587 Prev_Call
:= Relocate_Node
(Call_Node
);
3588 Set_Analyzed
(Prev_Call
);
3590 Param
:= First_Actual
(Call_Node
);
3596 Make_Selected_Component
(Loc
,
3597 Prefix
=> New_Value
(Param
),
3600 (First_Tag_Component
(Typ
), Loc
)),
3603 Make_Selected_Component
(Loc
,
3605 Unchecked_Convert_To
(Typ
,
3606 New_Value
(Next_Actual
(Param
))),
3609 (First_Tag_Component
(Typ
), Loc
))),
3610 Right_Opnd
=> Prev_Call
);
3612 Rewrite
(Call_Node
, New_Call
);
3615 (Call_Node
, Call_Typ
, Suppress
=> All_Checks
);
3618 -- Expansion of a dispatching call results in an indirect call,
3619 -- which in turn causes current values to be killed (see
3620 -- Resolve_Call), so on VM targets we do the call here to
3621 -- ensure consistent warnings between VM and non-VM targets.
3623 Kill_Current_Values
;
3626 -- If this is a dispatching "=" then we must update the reference
3627 -- to the call node because we generated:
3628 -- x.tag = y.tag and then x = y
3630 if Subp
= Eq_Prim_Op
then
3631 Call_Node
:= Right_Opnd
(Call_Node
);
3636 -- Similarly, expand calls to RCI subprograms on which pragma
3637 -- All_Calls_Remote applies. The rewriting will be reanalyzed
3638 -- later. Do this only when the call comes from source since we
3639 -- do not want such a rewriting to occur in expanded code.
3641 if Is_All_Remote_Call
(Call_Node
) then
3642 Expand_All_Calls_Remote_Subprogram_Call
(Call_Node
);
3644 -- Similarly, do not add extra actuals for an entry call whose entity
3645 -- is a protected procedure, or for an internal protected subprogram
3646 -- call, because it will be rewritten as a protected subprogram call
3647 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
3649 elsif Is_Protected_Type
(Scope
(Subp
))
3650 and then (Ekind
(Subp
) = E_Procedure
3651 or else Ekind
(Subp
) = E_Function
)
3655 -- During that loop we gathered the extra actuals (the ones that
3656 -- correspond to Extra_Formals), so now they can be appended.
3659 while Is_Non_Empty_List
(Extra_Actuals
) loop
3660 Add_Actual_Parameter
(Remove_Head
(Extra_Actuals
));
3664 -- At this point we have all the actuals, so this is the point at which
3665 -- the various expansion activities for actuals is carried out.
3667 Expand_Actuals
(Call_Node
, Subp
, Post_Call
);
3669 -- Verify that the actuals do not share storage. This check must be done
3670 -- on the caller side rather that inside the subprogram to avoid issues
3671 -- of parameter passing.
3673 if Check_Aliasing_Of_Parameters
then
3674 Apply_Parameter_Aliasing_Checks
(Call_Node
, Subp
);
3677 -- If the subprogram is a renaming, or if it is inherited, replace it in
3678 -- the call with the name of the actual subprogram being called. If this
3679 -- is a dispatching call, the run-time decides what to call. The Alias
3680 -- attribute does not apply to entries.
3682 if Nkind
(Call_Node
) /= N_Entry_Call_Statement
3683 and then No
(Controlling_Argument
(Call_Node
))
3684 and then Present
(Parent_Subp
)
3685 and then not Is_Direct_Deep_Call
(Subp
)
3687 if Present
(Inherited_From_Formal
(Subp
)) then
3688 Parent_Subp
:= Inherited_From_Formal
(Subp
);
3690 Parent_Subp
:= Ultimate_Alias
(Parent_Subp
);
3693 -- The below setting of Entity is suspect, see F109-018 discussion???
3695 Set_Entity
(Name
(Call_Node
), Parent_Subp
);
3697 if Is_Abstract_Subprogram
(Parent_Subp
)
3698 and then not In_Instance
3701 ("cannot call abstract subprogram &!",
3702 Name
(Call_Node
), Parent_Subp
);
3705 -- Inspect all formals of derived subprogram Subp. Compare parameter
3706 -- types with the parent subprogram and check whether an actual may
3707 -- need a type conversion to the corresponding formal of the parent
3710 -- Not clear whether intrinsic subprograms need such conversions. ???
3712 if not Is_Intrinsic_Subprogram
(Parent_Subp
)
3713 or else Is_Generic_Instance
(Parent_Subp
)
3716 procedure Convert
(Act
: Node_Id
; Typ
: Entity_Id
);
3717 -- Rewrite node Act as a type conversion of Act to Typ. Analyze
3718 -- and resolve the newly generated construct.
3724 procedure Convert
(Act
: Node_Id
; Typ
: Entity_Id
) is
3726 Rewrite
(Act
, OK_Convert_To
(Typ
, Relocate_Node
(Act
)));
3733 Actual_Typ
: Entity_Id
;
3734 Formal_Typ
: Entity_Id
;
3735 Parent_Typ
: Entity_Id
;
3738 Actual
:= First_Actual
(Call_Node
);
3739 Formal
:= First_Formal
(Subp
);
3740 Parent_Formal
:= First_Formal
(Parent_Subp
);
3741 while Present
(Formal
) loop
3742 Actual_Typ
:= Etype
(Actual
);
3743 Formal_Typ
:= Etype
(Formal
);
3744 Parent_Typ
:= Etype
(Parent_Formal
);
3746 -- For an IN parameter of a scalar type, the parent formal
3747 -- type and derived formal type differ or the parent formal
3748 -- type and actual type do not match statically.
3750 if Is_Scalar_Type
(Formal_Typ
)
3751 and then Ekind
(Formal
) = E_In_Parameter
3752 and then Formal_Typ
/= Parent_Typ
3754 not Subtypes_Statically_Match
(Parent_Typ
, Actual_Typ
)
3755 and then not Raises_Constraint_Error
(Actual
)
3757 Convert
(Actual
, Parent_Typ
);
3758 Enable_Range_Check
(Actual
);
3760 -- If the actual has been marked as requiring a range
3761 -- check, then generate it here.
3763 if Do_Range_Check
(Actual
) then
3764 Generate_Range_Check
3765 (Actual
, Etype
(Formal
), CE_Range_Check_Failed
);
3768 -- For access types, the parent formal type and actual type
3771 elsif Is_Access_Type
(Formal_Typ
)
3772 and then Base_Type
(Parent_Typ
) /= Base_Type
(Actual_Typ
)
3774 if Ekind
(Formal
) /= E_In_Parameter
then
3775 Convert
(Actual
, Parent_Typ
);
3777 elsif Ekind
(Parent_Typ
) = E_Anonymous_Access_Type
3778 and then Designated_Type
(Parent_Typ
) /=
3779 Designated_Type
(Actual_Typ
)
3780 and then not Is_Controlling_Formal
(Formal
)
3782 -- This unchecked conversion is not necessary unless
3783 -- inlining is enabled, because in that case the type
3784 -- mismatch may become visible in the body about to be
3788 Unchecked_Convert_To
(Parent_Typ
,
3789 Relocate_Node
(Actual
)));
3791 Resolve
(Actual
, Parent_Typ
);
3794 -- If there is a change of representation, then generate a
3795 -- warning, and do the change of representation.
3797 elsif not Same_Representation
(Formal_Typ
, Parent_Typ
) then
3799 ("??change of representation required", Actual
);
3800 Convert
(Actual
, Parent_Typ
);
3802 -- For array and record types, the parent formal type and
3803 -- derived formal type have different sizes or pragma Pack
3806 elsif ((Is_Array_Type
(Formal_Typ
)
3807 and then Is_Array_Type
(Parent_Typ
))
3809 (Is_Record_Type
(Formal_Typ
)
3810 and then Is_Record_Type
(Parent_Typ
)))
3812 (Esize
(Formal_Typ
) /= Esize
(Parent_Typ
)
3813 or else Has_Pragma_Pack
(Formal_Typ
) /=
3814 Has_Pragma_Pack
(Parent_Typ
))
3816 Convert
(Actual
, Parent_Typ
);
3819 Next_Actual
(Actual
);
3820 Next_Formal
(Formal
);
3821 Next_Formal
(Parent_Formal
);
3827 Subp
:= Parent_Subp
;
3830 -- Deal with case where call is an explicit dereference
3832 if Nkind
(Name
(Call_Node
)) = N_Explicit_Dereference
then
3834 -- Handle case of access to protected subprogram type
3836 if Is_Access_Protected_Subprogram_Type
3837 (Base_Type
(Etype
(Prefix
(Name
(Call_Node
)))))
3839 -- If this is a call through an access to protected operation, the
3840 -- prefix has the form (object'address, operation'access). Rewrite
3841 -- as a for other protected calls: the object is the 1st parameter
3842 -- of the list of actuals.
3849 Ptr
: constant Node_Id
:= Prefix
(Name
(Call_Node
));
3851 T
: constant Entity_Id
:=
3852 Equivalent_Type
(Base_Type
(Etype
(Ptr
)));
3854 D_T
: constant Entity_Id
:=
3855 Designated_Type
(Base_Type
(Etype
(Ptr
)));
3859 Make_Selected_Component
(Loc
,
3860 Prefix
=> Unchecked_Convert_To
(T
, Ptr
),
3862 New_Occurrence_Of
(First_Entity
(T
), Loc
));
3865 Make_Selected_Component
(Loc
,
3866 Prefix
=> Unchecked_Convert_To
(T
, Ptr
),
3868 New_Occurrence_Of
(Next_Entity
(First_Entity
(T
)), Loc
));
3871 Make_Explicit_Dereference
(Loc
,
3874 if Present
(Parameter_Associations
(Call_Node
)) then
3875 Parm
:= Parameter_Associations
(Call_Node
);
3880 Prepend
(Obj
, Parm
);
3882 if Etype
(D_T
) = Standard_Void_Type
then
3884 Make_Procedure_Call_Statement
(Loc
,
3886 Parameter_Associations
=> Parm
);
3889 Make_Function_Call
(Loc
,
3891 Parameter_Associations
=> Parm
);
3894 Set_First_Named_Actual
(Call
, First_Named_Actual
(Call_Node
));
3895 Set_Etype
(Call
, Etype
(D_T
));
3897 -- We do not re-analyze the call to avoid infinite recursion.
3898 -- We analyze separately the prefix and the object, and set
3899 -- the checks on the prefix that would otherwise be emitted
3900 -- when resolving a call.
3902 Rewrite
(Call_Node
, Call
);
3904 Apply_Access_Check
(Nam
);
3911 -- If this is a call to an intrinsic subprogram, then perform the
3912 -- appropriate expansion to the corresponding tree node and we
3913 -- are all done (since after that the call is gone).
3915 -- In the case where the intrinsic is to be processed by the back end,
3916 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
3917 -- since the idea in this case is to pass the call unchanged. If the
3918 -- intrinsic is an inherited unchecked conversion, and the derived type
3919 -- is the target type of the conversion, we must retain it as the return
3920 -- type of the expression. Otherwise the expansion below, which uses the
3921 -- parent operation, will yield the wrong type.
3923 if Is_Intrinsic_Subprogram
(Subp
) then
3924 Expand_Intrinsic_Call
(Call_Node
, Subp
);
3926 if Nkind
(Call_Node
) = N_Unchecked_Type_Conversion
3927 and then Parent_Subp
/= Orig_Subp
3928 and then Etype
(Parent_Subp
) /= Etype
(Orig_Subp
)
3930 Set_Etype
(Call_Node
, Etype
(Orig_Subp
));
3936 if Ekind_In
(Subp
, E_Function
, E_Procedure
) then
3938 -- We perform a simple optimization on calls for To_Address by
3939 -- replacing them with an unchecked conversion. Not only is this
3940 -- efficient, but it also avoids order of elaboration problems when
3941 -- address clauses are inlined (address expression elaborated at the
3944 -- We perform this optimization regardless of whether we are in the
3945 -- main unit or in a unit in the context of the main unit, to ensure
3946 -- that the generated tree is the same in both cases, for CodePeer
3949 if Is_RTE
(Subp
, RE_To_Address
) then
3951 Unchecked_Convert_To
3952 (RTE
(RE_Address
), Relocate_Node
(First_Actual
(Call_Node
))));
3956 -- Handle inlining. No action needed if the subprogram is not inlined
3958 if not Is_Inlined
(Subp
) then
3961 -- Frontend inlining of expression functions (performed also when
3962 -- backend inlining is enabled).
3964 elsif Is_Inlinable_Expression_Function
(Subp
) then
3965 Rewrite
(N
, New_Copy
(Expression_Of_Expression_Function
(Subp
)));
3969 -- Handle frontend inlining
3971 elsif not Back_End_Inlining
then
3972 Inlined_Subprogram
: declare
3974 Must_Inline
: Boolean := False;
3975 Spec
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
3978 -- Verify that the body to inline has already been seen, and
3979 -- that if the body is in the current unit the inlining does
3980 -- not occur earlier. This avoids order-of-elaboration problems
3983 -- This should be documented in sinfo/einfo ???
3986 or else Nkind
(Spec
) /= N_Subprogram_Declaration
3987 or else No
(Body_To_Inline
(Spec
))
3989 Must_Inline
:= False;
3991 -- If this an inherited function that returns a private type,
3992 -- do not inline if the full view is an unconstrained array,
3993 -- because such calls cannot be inlined.
3995 elsif Present
(Orig_Subp
)
3996 and then Is_Array_Type
(Etype
(Orig_Subp
))
3997 and then not Is_Constrained
(Etype
(Orig_Subp
))
3999 Must_Inline
:= False;
4001 elsif In_Unfrozen_Instance
(Scope
(Subp
)) then
4002 Must_Inline
:= False;
4005 Bod
:= Body_To_Inline
(Spec
);
4007 if (In_Extended_Main_Code_Unit
(Call_Node
)
4008 or else In_Extended_Main_Code_Unit
(Parent
(Call_Node
))
4009 or else Has_Pragma_Inline_Always
(Subp
))
4010 and then (not In_Same_Extended_Unit
(Sloc
(Bod
), Loc
)
4012 Earlier_In_Extended_Unit
(Sloc
(Bod
), Loc
))
4014 Must_Inline
:= True;
4016 -- If we are compiling a package body that is not the main
4017 -- unit, it must be for inlining/instantiation purposes,
4018 -- in which case we inline the call to insure that the same
4019 -- temporaries are generated when compiling the body by
4020 -- itself. Otherwise link errors can occur.
4022 -- If the function being called is itself in the main unit,
4023 -- we cannot inline, because there is a risk of double
4024 -- elaboration and/or circularity: the inlining can make
4025 -- visible a private entity in the body of the main unit,
4026 -- that gigi will see before its sees its proper definition.
4028 elsif not (In_Extended_Main_Code_Unit
(Call_Node
))
4029 and then In_Package_Body
4031 Must_Inline
:= not In_Extended_Main_Source_Unit
(Subp
);
4033 -- Inline calls to _postconditions when generating C code
4035 elsif Modify_Tree_For_C
4036 and then In_Same_Extended_Unit
(Sloc
(Bod
), Loc
)
4037 and then Chars
(Name
(N
)) = Name_uPostconditions
4039 Must_Inline
:= True;
4044 Expand_Inlined_Call
(Call_Node
, Subp
, Orig_Subp
);
4047 -- Let the back end handle it
4049 Add_Inlined_Body
(Subp
, Call_Node
);
4051 if Front_End_Inlining
4052 and then Nkind
(Spec
) = N_Subprogram_Declaration
4053 and then (In_Extended_Main_Code_Unit
(Call_Node
))
4054 and then No
(Body_To_Inline
(Spec
))
4055 and then not Has_Completion
(Subp
)
4056 and then In_Same_Extended_Unit
(Sloc
(Spec
), Loc
)
4059 ("cannot inline& (body not seen yet)?",
4063 end Inlined_Subprogram
;
4065 -- Back end inlining: let the back end handle it
4067 elsif No
(Unit_Declaration_Node
(Subp
))
4068 or else Nkind
(Unit_Declaration_Node
(Subp
)) /=
4069 N_Subprogram_Declaration
4070 or else No
(Body_To_Inline
(Unit_Declaration_Node
(Subp
)))
4071 or else Nkind
(Body_To_Inline
(Unit_Declaration_Node
(Subp
))) in
4074 Add_Inlined_Body
(Subp
, Call_Node
);
4076 -- If the inlined call appears within an instantiation and some
4077 -- level of optimization is required, ensure that the enclosing
4078 -- instance body is available so that the back-end can actually
4079 -- perform the inlining.
4082 and then Comes_From_Source
(Subp
)
4083 and then Optimization_Level
> 0
4088 Inst_Node
: Node_Id
;
4091 Inst
:= Scope
(Subp
);
4093 -- Find enclosing instance
4095 while Present
(Inst
) and then Inst
/= Standard_Standard
loop
4096 exit when Is_Generic_Instance
(Inst
);
4097 Inst
:= Scope
(Inst
);
4101 and then Is_Generic_Instance
(Inst
)
4102 and then not Is_Inlined
(Inst
)
4104 Set_Is_Inlined
(Inst
);
4105 Decl
:= Unit_Declaration_Node
(Inst
);
4107 -- Do not add a pending instantiation if the body exits
4108 -- already, or if the instance is a compilation unit, or
4109 -- the instance node is missing.
4111 if Present
(Corresponding_Body
(Decl
))
4112 or else Nkind
(Parent
(Decl
)) = N_Compilation_Unit
4113 or else No
(Next
(Decl
))
4118 -- The instantiation node usually follows the package
4119 -- declaration for the instance. If the generic unit
4120 -- has aspect specifications, they are transformed
4121 -- into pragmas in the instance, and the instance node
4122 -- appears after them.
4124 Inst_Node
:= Next
(Decl
);
4126 while Nkind
(Inst_Node
) /= N_Package_Instantiation
loop
4127 Inst_Node
:= Next
(Inst_Node
);
4130 Add_Pending_Instantiation
(Inst_Node
, Decl
);
4136 -- Front end expansion of simple functions returning unconstrained
4137 -- types (see Check_And_Split_Unconstrained_Function). Note that the
4138 -- case of a simple renaming (Body_To_Inline in N_Entity above, see
4139 -- also Build_Renamed_Body) cannot be expanded here because this may
4140 -- give rise to order-of-elaboration issues for the types of the
4141 -- parameters of the subprogram, if any.
4144 Expand_Inlined_Call
(Call_Node
, Subp
, Orig_Subp
);
4148 -- Check for protected subprogram. This is either an intra-object call,
4149 -- or a protected function call. Protected procedure calls are rewritten
4150 -- as entry calls and handled accordingly.
4152 -- In Ada 2005, this may be an indirect call to an access parameter that
4153 -- is an access_to_subprogram. In that case the anonymous type has a
4154 -- scope that is a protected operation, but the call is a regular one.
4155 -- In either case do not expand call if subprogram is eliminated.
4157 Scop
:= Scope
(Subp
);
4159 if Nkind
(Call_Node
) /= N_Entry_Call_Statement
4160 and then Is_Protected_Type
(Scop
)
4161 and then Ekind
(Subp
) /= E_Subprogram_Type
4162 and then not Is_Eliminated
(Subp
)
4164 -- If the call is an internal one, it is rewritten as a call to the
4165 -- corresponding unprotected subprogram.
4167 Expand_Protected_Subprogram_Call
(Call_Node
, Subp
, Scop
);
4170 -- Functions returning controlled objects need special attention. If
4171 -- the return type is limited, then the context is initialization and
4172 -- different processing applies. If the call is to a protected function,
4173 -- the expansion above will call Expand_Call recursively. Otherwise the
4174 -- function call is transformed into a temporary which obtains the
4175 -- result from the secondary stack.
4177 if Needs_Finalization
(Etype
(Subp
)) then
4178 if not Is_Limited_View
(Etype
(Subp
))
4180 (No
(First_Formal
(Subp
))
4182 not Is_Concurrent_Record_Type
(Etype
(First_Formal
(Subp
))))
4184 Expand_Ctrl_Function_Call
(Call_Node
);
4186 -- Build-in-place function calls which appear in anonymous contexts
4187 -- need a transient scope to ensure the proper finalization of the
4188 -- intermediate result after its use.
4190 elsif Is_Build_In_Place_Function_Call
(Call_Node
)
4192 Nkind_In
(Parent
(Call_Node
), N_Attribute_Reference
,
4194 N_Indexed_Component
,
4195 N_Object_Renaming_Declaration
,
4196 N_Procedure_Call_Statement
,
4197 N_Selected_Component
,
4200 Establish_Transient_Scope
(Call_Node
, Sec_Stack
=> True);
4203 end Expand_Call_Helper
;
4205 -------------------------------
4206 -- Expand_Ctrl_Function_Call --
4207 -------------------------------
4209 procedure Expand_Ctrl_Function_Call
(N
: Node_Id
) is
4210 function Is_Element_Reference
(N
: Node_Id
) return Boolean;
4211 -- Determine whether node N denotes a reference to an Ada 2012 container
4214 --------------------------
4215 -- Is_Element_Reference --
4216 --------------------------
4218 function Is_Element_Reference
(N
: Node_Id
) return Boolean is
4219 Ref
: constant Node_Id
:= Original_Node
(N
);
4222 -- Analysis marks an element reference by setting the generalized
4223 -- indexing attribute of an indexed component before the component
4224 -- is rewritten into a function call.
4227 Nkind
(Ref
) = N_Indexed_Component
4228 and then Present
(Generalized_Indexing
(Ref
));
4229 end Is_Element_Reference
;
4231 -- Start of processing for Expand_Ctrl_Function_Call
4234 -- Optimization, if the returned value (which is on the sec-stack) is
4235 -- returned again, no need to copy/readjust/finalize, we can just pass
4236 -- the value thru (see Expand_N_Simple_Return_Statement), and thus no
4237 -- attachment is needed
4239 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
then
4243 -- Resolution is now finished, make sure we don't start analysis again
4244 -- because of the duplication.
4248 -- A function which returns a controlled object uses the secondary
4249 -- stack. Rewrite the call into a temporary which obtains the result of
4250 -- the function using 'reference.
4252 Remove_Side_Effects
(N
);
4254 -- The side effect removal of the function call produced a temporary.
4255 -- When the context is a case expression, if expression, or expression
4256 -- with actions, the lifetime of the temporary must be extended to match
4257 -- that of the context. Otherwise the function result will be finalized
4258 -- too early and affect the result of the expression. To prevent this
4259 -- unwanted effect, the temporary should not be considered for clean up
4260 -- actions by the general finalization machinery.
4262 -- Exception to this rule are references to Ada 2012 container elements.
4263 -- Such references must be finalized at the end of each iteration of the
4264 -- related quantified expression, otherwise the container will remain
4267 if Nkind
(N
) = N_Explicit_Dereference
4268 and then Within_Case_Or_If_Expression
(N
)
4269 and then not Is_Element_Reference
(N
)
4271 Set_Is_Ignored_Transient
(Entity
(Prefix
(N
)));
4273 end Expand_Ctrl_Function_Call
;
4275 ----------------------------------------
4276 -- Expand_N_Extended_Return_Statement --
4277 ----------------------------------------
4279 -- If there is a Handled_Statement_Sequence, we rewrite this:
4281 -- return Result : T := <expression> do
4282 -- <handled_seq_of_stms>
4288 -- Result : T := <expression>;
4290 -- <handled_seq_of_stms>
4294 -- Otherwise (no Handled_Statement_Sequence), we rewrite this:
4296 -- return Result : T := <expression>;
4300 -- return <expression>;
4302 -- unless it's build-in-place or there's no <expression>, in which case
4306 -- Result : T := <expression>;
4311 -- Note that this case could have been written by the user as an extended
4312 -- return statement, or could have been transformed to this from a simple
4313 -- return statement.
4315 -- That is, we need to have a reified return object if there are statements
4316 -- (which might refer to it) or if we're doing build-in-place (so we can
4317 -- set its address to the final resting place or if there is no expression
4318 -- (in which case default initial values might need to be set).
4320 procedure Expand_N_Extended_Return_Statement
(N
: Node_Id
) is
4321 Loc
: constant Source_Ptr
:= Sloc
(N
);
4323 function Build_Heap_Allocator
4324 (Temp_Id
: Entity_Id
;
4325 Temp_Typ
: Entity_Id
;
4326 Func_Id
: Entity_Id
;
4327 Ret_Typ
: Entity_Id
;
4328 Alloc_Expr
: Node_Id
) return Node_Id
;
4329 -- Create the statements necessary to allocate a return object on the
4330 -- caller's master. The master is available through implicit parameter
4331 -- BIPfinalizationmaster.
4333 -- if BIPfinalizationmaster /= null then
4335 -- type Ptr_Typ is access Ret_Typ;
4336 -- for Ptr_Typ'Storage_Pool use
4337 -- Base_Pool (BIPfinalizationmaster.all).all;
4341 -- procedure Allocate (...) is
4343 -- System.Storage_Pools.Subpools.Allocate_Any (...);
4346 -- Local := <Alloc_Expr>;
4347 -- Temp_Id := Temp_Typ (Local);
4351 -- Temp_Id is the temporary which is used to reference the internally
4352 -- created object in all allocation forms. Temp_Typ is the type of the
4353 -- temporary. Func_Id is the enclosing function. Ret_Typ is the return
4354 -- type of Func_Id. Alloc_Expr is the actual allocator.
4356 function Move_Activation_Chain
(Func_Id
: Entity_Id
) return Node_Id
;
4357 -- Construct a call to System.Tasking.Stages.Move_Activation_Chain
4359 -- From current activation chain
4360 -- To activation chain passed in by the caller
4361 -- New_Master master passed in by the caller
4363 -- Func_Id is the entity of the function where the extended return
4364 -- statement appears.
4366 --------------------------
4367 -- Build_Heap_Allocator --
4368 --------------------------
4370 function Build_Heap_Allocator
4371 (Temp_Id
: Entity_Id
;
4372 Temp_Typ
: Entity_Id
;
4373 Func_Id
: Entity_Id
;
4374 Ret_Typ
: Entity_Id
;
4375 Alloc_Expr
: Node_Id
) return Node_Id
4378 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
4380 -- Processing for build-in-place object allocation.
4382 if Needs_Finalization
(Ret_Typ
) then
4384 Decls
: constant List_Id
:= New_List
;
4385 Fin_Mas_Id
: constant Entity_Id
:=
4386 Build_In_Place_Formal
4387 (Func_Id
, BIP_Finalization_Master
);
4388 Stmts
: constant List_Id
:= New_List
;
4389 Desig_Typ
: Entity_Id
;
4390 Local_Id
: Entity_Id
;
4391 Pool_Id
: Entity_Id
;
4392 Ptr_Typ
: Entity_Id
;
4396 -- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
4398 Pool_Id
:= Make_Temporary
(Loc
, 'P');
4401 Make_Object_Renaming_Declaration
(Loc
,
4402 Defining_Identifier
=> Pool_Id
,
4404 New_Occurrence_Of
(RTE
(RE_Root_Storage_Pool
), Loc
),
4406 Make_Explicit_Dereference
(Loc
,
4408 Make_Function_Call
(Loc
,
4410 New_Occurrence_Of
(RTE
(RE_Base_Pool
), Loc
),
4411 Parameter_Associations
=> New_List
(
4412 Make_Explicit_Dereference
(Loc
,
4414 New_Occurrence_Of
(Fin_Mas_Id
, Loc
)))))));
4416 -- Create an access type which uses the storage pool of the
4417 -- caller's master. This additional type is necessary because
4418 -- the finalization master cannot be associated with the type
4419 -- of the temporary. Otherwise the secondary stack allocation
4422 Desig_Typ
:= Ret_Typ
;
4424 -- Ensure that the build-in-place machinery uses a fat pointer
4425 -- when allocating an unconstrained array on the heap. In this
4426 -- case the result object type is a constrained array type even
4427 -- though the function type is unconstrained.
4429 if Ekind
(Desig_Typ
) = E_Array_Subtype
then
4430 Desig_Typ
:= Base_Type
(Desig_Typ
);
4434 -- type Ptr_Typ is access Desig_Typ;
4436 Ptr_Typ
:= Make_Temporary
(Loc
, 'P');
4439 Make_Full_Type_Declaration
(Loc
,
4440 Defining_Identifier
=> Ptr_Typ
,
4442 Make_Access_To_Object_Definition
(Loc
,
4443 Subtype_Indication
=>
4444 New_Occurrence_Of
(Desig_Typ
, Loc
))));
4446 -- Perform minor decoration in order to set the master and the
4447 -- storage pool attributes.
4449 Set_Ekind
(Ptr_Typ
, E_Access_Type
);
4450 Set_Finalization_Master
(Ptr_Typ
, Fin_Mas_Id
);
4451 Set_Associated_Storage_Pool
(Ptr_Typ
, Pool_Id
);
4453 -- Create the temporary, generate:
4454 -- Local_Id : Ptr_Typ;
4456 Local_Id
:= Make_Temporary
(Loc
, 'T');
4459 Make_Object_Declaration
(Loc
,
4460 Defining_Identifier
=> Local_Id
,
4461 Object_Definition
=>
4462 New_Occurrence_Of
(Ptr_Typ
, Loc
)));
4464 -- Allocate the object, generate:
4465 -- Local_Id := <Alloc_Expr>;
4468 Make_Assignment_Statement
(Loc
,
4469 Name
=> New_Occurrence_Of
(Local_Id
, Loc
),
4470 Expression
=> Alloc_Expr
));
4473 -- Temp_Id := Temp_Typ (Local_Id);
4476 Make_Assignment_Statement
(Loc
,
4477 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4479 Unchecked_Convert_To
(Temp_Typ
,
4480 New_Occurrence_Of
(Local_Id
, Loc
))));
4482 -- Wrap the allocation in a block. This is further conditioned
4483 -- by checking the caller finalization master at runtime. A
4484 -- null value indicates a non-existent master, most likely due
4485 -- to a Finalize_Storage_Only allocation.
4488 -- if BIPfinalizationmaster /= null then
4497 Make_If_Statement
(Loc
,
4500 Left_Opnd
=> New_Occurrence_Of
(Fin_Mas_Id
, Loc
),
4501 Right_Opnd
=> Make_Null
(Loc
)),
4503 Then_Statements
=> New_List
(
4504 Make_Block_Statement
(Loc
,
4505 Declarations
=> Decls
,
4506 Handled_Statement_Sequence
=>
4507 Make_Handled_Sequence_Of_Statements
(Loc
,
4508 Statements
=> Stmts
))));
4511 -- For all other cases, generate:
4512 -- Temp_Id := <Alloc_Expr>;
4516 Make_Assignment_Statement
(Loc
,
4517 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4518 Expression
=> Alloc_Expr
);
4520 end Build_Heap_Allocator
;
4522 ---------------------------
4523 -- Move_Activation_Chain --
4524 ---------------------------
4526 function Move_Activation_Chain
(Func_Id
: Entity_Id
) return Node_Id
is
4529 Make_Procedure_Call_Statement
(Loc
,
4531 New_Occurrence_Of
(RTE
(RE_Move_Activation_Chain
), Loc
),
4533 Parameter_Associations
=> New_List
(
4537 Make_Attribute_Reference
(Loc
,
4538 Prefix
=> Make_Identifier
(Loc
, Name_uChain
),
4539 Attribute_Name
=> Name_Unrestricted_Access
),
4541 -- Destination chain
4544 (Build_In_Place_Formal
(Func_Id
, BIP_Activation_Chain
), Loc
),
4549 (Build_In_Place_Formal
(Func_Id
, BIP_Task_Master
), Loc
)));
4550 end Move_Activation_Chain
;
4554 Func_Id
: constant Entity_Id
:=
4555 Return_Applies_To
(Return_Statement_Entity
(N
));
4556 Is_BIP_Func
: constant Boolean :=
4557 Is_Build_In_Place_Function
(Func_Id
);
4558 Ret_Obj_Id
: constant Entity_Id
:=
4559 First_Entity
(Return_Statement_Entity
(N
));
4560 Ret_Obj_Decl
: constant Node_Id
:= Parent
(Ret_Obj_Id
);
4561 Ret_Typ
: constant Entity_Id
:= Etype
(Func_Id
);
4566 Return_Stmt
: Node_Id
;
4569 -- Start of processing for Expand_N_Extended_Return_Statement
4572 -- Given that functionality of interface thunks is simple (just displace
4573 -- the pointer to the object) they are always handled by means of
4574 -- simple return statements.
4576 pragma Assert
(not Is_Thunk
(Current_Scope
));
4578 if Nkind
(Ret_Obj_Decl
) = N_Object_Declaration
then
4579 Exp
:= Expression
(Ret_Obj_Decl
);
4584 HSS
:= Handled_Statement_Sequence
(N
);
4586 -- If the returned object needs finalization actions, the function must
4587 -- perform the appropriate cleanup should it fail to return. The state
4588 -- of the function itself is tracked through a flag which is coupled
4589 -- with the scope finalizer. There is one flag per each return object
4590 -- in case of multiple returns.
4592 if Is_BIP_Func
and then Needs_Finalization
(Etype
(Ret_Obj_Id
)) then
4594 Flag_Decl
: Node_Id
;
4595 Flag_Id
: Entity_Id
;
4599 -- Recover the function body
4601 Func_Bod
:= Unit_Declaration_Node
(Func_Id
);
4603 if Nkind
(Func_Bod
) = N_Subprogram_Declaration
then
4604 Func_Bod
:= Parent
(Parent
(Corresponding_Body
(Func_Bod
)));
4607 -- Create a flag to track the function state
4609 Flag_Id
:= Make_Temporary
(Loc
, 'F');
4610 Set_Status_Flag_Or_Transient_Decl
(Ret_Obj_Id
, Flag_Id
);
4612 -- Insert the flag at the beginning of the function declarations,
4614 -- Fnn : Boolean := False;
4617 Make_Object_Declaration
(Loc
,
4618 Defining_Identifier
=> Flag_Id
,
4619 Object_Definition
=>
4620 New_Occurrence_Of
(Standard_Boolean
, Loc
),
4622 New_Occurrence_Of
(Standard_False
, Loc
));
4624 Prepend_To
(Declarations
(Func_Bod
), Flag_Decl
);
4625 Analyze
(Flag_Decl
);
4629 -- Build a simple_return_statement that returns the return object when
4630 -- there is a statement sequence, or no expression, or the result will
4631 -- be built in place. Note however that we currently do this for all
4632 -- composite cases, even though nonlimited composite results are not yet
4633 -- built in place (though we plan to do so eventually).
4636 or else Is_Composite_Type
(Ret_Typ
)
4642 -- If the extended return has a handled statement sequence, then wrap
4643 -- it in a block and use the block as the first statement.
4647 Make_Block_Statement
(Loc
,
4648 Declarations
=> New_List
,
4649 Handled_Statement_Sequence
=> HSS
));
4652 -- If the result type contains tasks, we call Move_Activation_Chain.
4653 -- Later, the cleanup code will call Complete_Master, which will
4654 -- terminate any unactivated tasks belonging to the return statement
4655 -- master. But Move_Activation_Chain updates their master to be that
4656 -- of the caller, so they will not be terminated unless the return
4657 -- statement completes unsuccessfully due to exception, abort, goto,
4658 -- or exit. As a formality, we test whether the function requires the
4659 -- result to be built in place, though that's necessarily true for
4660 -- the case of result types with task parts.
4662 if Is_BIP_Func
and then Has_Task
(Ret_Typ
) then
4664 -- The return expression is an aggregate for a complex type which
4665 -- contains tasks. This particular case is left unexpanded since
4666 -- the regular expansion would insert all temporaries and
4667 -- initialization code in the wrong block.
4669 if Nkind
(Exp
) = N_Aggregate
then
4670 Expand_N_Aggregate
(Exp
);
4673 -- Do not move the activation chain if the return object does not
4676 if Has_Task
(Etype
(Ret_Obj_Id
)) then
4677 Append_To
(Stmts
, Move_Activation_Chain
(Func_Id
));
4681 -- Update the state of the function right before the object is
4684 if Is_BIP_Func
and then Needs_Finalization
(Etype
(Ret_Obj_Id
)) then
4686 Flag_Id
: constant Entity_Id
:=
4687 Status_Flag_Or_Transient_Decl
(Ret_Obj_Id
);
4694 Make_Assignment_Statement
(Loc
,
4695 Name
=> New_Occurrence_Of
(Flag_Id
, Loc
),
4696 Expression
=> New_Occurrence_Of
(Standard_True
, Loc
)));
4700 -- Build a simple_return_statement that returns the return object
4703 Make_Simple_Return_Statement
(Loc
,
4704 Expression
=> New_Occurrence_Of
(Ret_Obj_Id
, Loc
));
4705 Append_To
(Stmts
, Return_Stmt
);
4707 HSS
:= Make_Handled_Sequence_Of_Statements
(Loc
, Stmts
);
4710 -- Case where we build a return statement block
4712 if Present
(HSS
) then
4714 Make_Block_Statement
(Loc
,
4715 Declarations
=> Return_Object_Declarations
(N
),
4716 Handled_Statement_Sequence
=> HSS
);
4718 -- We set the entity of the new block statement to be that of the
4719 -- return statement. This is necessary so that various fields, such
4720 -- as Finalization_Chain_Entity carry over from the return statement
4721 -- to the block. Note that this block is unusual, in that its entity
4722 -- is an E_Return_Statement rather than an E_Block.
4725 (Result
, New_Occurrence_Of
(Return_Statement_Entity
(N
), Loc
));
4727 -- If the object decl was already rewritten as a renaming, then we
4728 -- don't want to do the object allocation and transformation of
4729 -- the return object declaration to a renaming. This case occurs
4730 -- when the return object is initialized by a call to another
4731 -- build-in-place function, and that function is responsible for
4732 -- the allocation of the return object.
4735 and then Nkind
(Ret_Obj_Decl
) = N_Object_Renaming_Declaration
4738 (Nkind
(Original_Node
(Ret_Obj_Decl
)) = N_Object_Declaration
4739 and then Is_Build_In_Place_Function_Call
4740 (Expression
(Original_Node
(Ret_Obj_Decl
))));
4742 -- Return the build-in-place result by reference
4744 Set_By_Ref
(Return_Stmt
);
4746 elsif Is_BIP_Func
then
4748 -- Locate the implicit access parameter associated with the
4749 -- caller-supplied return object and convert the return
4750 -- statement's return object declaration to a renaming of a
4751 -- dereference of the access parameter. If the return object's
4752 -- declaration includes an expression that has not already been
4753 -- expanded as separate assignments, then add an assignment
4754 -- statement to ensure the return object gets initialized.
4757 -- Result : T [:= <expression>];
4764 -- Result : T renames FuncRA.all;
4765 -- [Result := <expression;]
4770 Ret_Obj_Expr
: constant Node_Id
:= Expression
(Ret_Obj_Decl
);
4771 Ret_Obj_Typ
: constant Entity_Id
:= Etype
(Ret_Obj_Id
);
4773 Init_Assignment
: Node_Id
:= Empty
;
4774 Obj_Acc_Formal
: Entity_Id
;
4775 Obj_Acc_Deref
: Node_Id
;
4776 Obj_Alloc_Formal
: Entity_Id
;
4779 -- Build-in-place results must be returned by reference
4781 Set_By_Ref
(Return_Stmt
);
4783 -- Retrieve the implicit access parameter passed by the caller
4786 Build_In_Place_Formal
(Func_Id
, BIP_Object_Access
);
4788 -- If the return object's declaration includes an expression
4789 -- and the declaration isn't marked as No_Initialization, then
4790 -- we need to generate an assignment to the object and insert
4791 -- it after the declaration before rewriting it as a renaming
4792 -- (otherwise we'll lose the initialization). The case where
4793 -- the result type is an interface (or class-wide interface)
4794 -- is also excluded because the context of the function call
4795 -- must be unconstrained, so the initialization will always
4796 -- be done as part of an allocator evaluation (storage pool
4797 -- or secondary stack), never to a constrained target object
4798 -- passed in by the caller. Besides the assignment being
4799 -- unneeded in this case, it avoids problems with trying to
4800 -- generate a dispatching assignment when the return expression
4801 -- is a nonlimited descendant of a limited interface (the
4802 -- interface has no assignment operation).
4804 if Present
(Ret_Obj_Expr
)
4805 and then not No_Initialization
(Ret_Obj_Decl
)
4806 and then not Is_Interface
(Ret_Obj_Typ
)
4809 Make_Assignment_Statement
(Loc
,
4810 Name
=> New_Occurrence_Of
(Ret_Obj_Id
, Loc
),
4811 Expression
=> New_Copy_Tree
(Ret_Obj_Expr
));
4813 Set_Etype
(Name
(Init_Assignment
), Etype
(Ret_Obj_Id
));
4814 Set_Assignment_OK
(Name
(Init_Assignment
));
4815 Set_No_Ctrl_Actions
(Init_Assignment
);
4817 Set_Parent
(Name
(Init_Assignment
), Init_Assignment
);
4818 Set_Parent
(Expression
(Init_Assignment
), Init_Assignment
);
4820 Set_Expression
(Ret_Obj_Decl
, Empty
);
4822 if Is_Class_Wide_Type
(Etype
(Ret_Obj_Id
))
4823 and then not Is_Class_Wide_Type
4824 (Etype
(Expression
(Init_Assignment
)))
4826 Rewrite
(Expression
(Init_Assignment
),
4827 Make_Type_Conversion
(Loc
,
4829 New_Occurrence_Of
(Etype
(Ret_Obj_Id
), Loc
),
4831 Relocate_Node
(Expression
(Init_Assignment
))));
4834 -- In the case of functions where the calling context can
4835 -- determine the form of allocation needed, initialization
4836 -- is done with each part of the if statement that handles
4837 -- the different forms of allocation (this is true for
4838 -- unconstrained and tagged result subtypes).
4840 if Is_Constrained
(Ret_Typ
)
4841 and then not Is_Tagged_Type
(Underlying_Type
(Ret_Typ
))
4843 Insert_After
(Ret_Obj_Decl
, Init_Assignment
);
4847 -- When the function's subtype is unconstrained, a run-time
4848 -- test is needed to determine the form of allocation to use
4849 -- for the return object. The function has an implicit formal
4850 -- parameter indicating this. If the BIP_Alloc_Form formal has
4851 -- the value one, then the caller has passed access to an
4852 -- existing object for use as the return object. If the value
4853 -- is two, then the return object must be allocated on the
4854 -- secondary stack. Otherwise, the object must be allocated in
4855 -- a storage pool (currently only supported for the global
4856 -- heap, user-defined storage pools TBD ???). We generate an
4857 -- if statement to test the implicit allocation formal and
4858 -- initialize a local access value appropriately, creating
4859 -- allocators in the secondary stack and global heap cases.
4860 -- The special formal also exists and must be tested when the
4861 -- function has a tagged result, even when the result subtype
4862 -- is constrained, because in general such functions can be
4863 -- called in dispatching contexts and must be handled similarly
4864 -- to functions with a class-wide result.
4866 if not Is_Constrained
(Ret_Typ
)
4867 or else Is_Tagged_Type
(Underlying_Type
(Ret_Typ
))
4870 Build_In_Place_Formal
(Func_Id
, BIP_Alloc_Form
);
4873 Pool_Id
: constant Entity_Id
:=
4874 Make_Temporary
(Loc
, 'P');
4875 Alloc_Obj_Id
: Entity_Id
;
4876 Alloc_Obj_Decl
: Node_Id
;
4877 Alloc_If_Stmt
: Node_Id
;
4878 Heap_Allocator
: Node_Id
;
4879 Pool_Decl
: Node_Id
;
4880 Pool_Allocator
: Node_Id
;
4881 Ptr_Type_Decl
: Node_Id
;
4882 Ref_Type
: Entity_Id
;
4883 SS_Allocator
: Node_Id
;
4886 -- Reuse the itype created for the function's implicit
4887 -- access formal. This avoids the need to create a new
4888 -- access type here, plus it allows assigning the access
4889 -- formal directly without applying a conversion.
4891 -- Ref_Type := Etype (Object_Access);
4893 -- Create an access type designating the function's
4896 Ref_Type
:= Make_Temporary
(Loc
, 'A');
4899 Make_Full_Type_Declaration
(Loc
,
4900 Defining_Identifier
=> Ref_Type
,
4902 Make_Access_To_Object_Definition
(Loc
,
4903 All_Present
=> True,
4904 Subtype_Indication
=>
4905 New_Occurrence_Of
(Ret_Obj_Typ
, Loc
)));
4907 Insert_Before
(Ret_Obj_Decl
, Ptr_Type_Decl
);
4909 -- Create an access object that will be initialized to an
4910 -- access value denoting the return object, either coming
4911 -- from an implicit access value passed in by the caller
4912 -- or from the result of an allocator.
4914 Alloc_Obj_Id
:= Make_Temporary
(Loc
, 'R');
4915 Set_Etype
(Alloc_Obj_Id
, Ref_Type
);
4918 Make_Object_Declaration
(Loc
,
4919 Defining_Identifier
=> Alloc_Obj_Id
,
4920 Object_Definition
=>
4921 New_Occurrence_Of
(Ref_Type
, Loc
));
4923 Insert_Before
(Ret_Obj_Decl
, Alloc_Obj_Decl
);
4925 -- Create allocators for both the secondary stack and
4926 -- global heap. If there's an initialization expression,
4927 -- then create these as initialized allocators.
4929 if Present
(Ret_Obj_Expr
)
4930 and then not No_Initialization
(Ret_Obj_Decl
)
4932 -- Always use the type of the expression for the
4933 -- qualified expression, rather than the result type.
4934 -- In general we cannot always use the result type
4935 -- for the allocator, because the expression might be
4936 -- of a specific type, such as in the case of an
4937 -- aggregate or even a nonlimited object when the
4938 -- result type is a limited class-wide interface type.
4941 Make_Allocator
(Loc
,
4943 Make_Qualified_Expression
(Loc
,
4946 (Etype
(Ret_Obj_Expr
), Loc
),
4947 Expression
=> New_Copy_Tree
(Ret_Obj_Expr
)));
4950 -- If the function returns a class-wide type we cannot
4951 -- use the return type for the allocator. Instead we
4952 -- use the type of the expression, which must be an
4953 -- aggregate of a definite type.
4955 if Is_Class_Wide_Type
(Ret_Obj_Typ
) then
4957 Make_Allocator
(Loc
,
4960 (Etype
(Ret_Obj_Expr
), Loc
));
4963 Make_Allocator
(Loc
,
4965 New_Occurrence_Of
(Ret_Obj_Typ
, Loc
));
4968 -- If the object requires default initialization then
4969 -- that will happen later following the elaboration of
4970 -- the object renaming. If we don't turn it off here
4971 -- then the object will be default initialized twice.
4973 Set_No_Initialization
(Heap_Allocator
);
4976 -- The Pool_Allocator is just like the Heap_Allocator,
4977 -- except we set Storage_Pool and Procedure_To_Call so
4978 -- it will use the user-defined storage pool.
4980 Pool_Allocator
:= New_Copy_Tree
(Heap_Allocator
);
4982 -- Do not generate the renaming of the build-in-place
4983 -- pool parameter on ZFP because the parameter is not
4984 -- created in the first place.
4986 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
4988 Make_Object_Renaming_Declaration
(Loc
,
4989 Defining_Identifier
=> Pool_Id
,
4992 (RTE
(RE_Root_Storage_Pool
), Loc
),
4994 Make_Explicit_Dereference
(Loc
,
4996 (Build_In_Place_Formal
4997 (Func_Id
, BIP_Storage_Pool
), Loc
)));
4998 Set_Storage_Pool
(Pool_Allocator
, Pool_Id
);
4999 Set_Procedure_To_Call
5000 (Pool_Allocator
, RTE
(RE_Allocate_Any
));
5002 Pool_Decl
:= Make_Null_Statement
(Loc
);
5005 -- If the No_Allocators restriction is active, then only
5006 -- an allocator for secondary stack allocation is needed.
5007 -- It's OK for such allocators to have Comes_From_Source
5008 -- set to False, because gigi knows not to flag them as
5009 -- being a violation of No_Implicit_Heap_Allocations.
5011 if Restriction_Active
(No_Allocators
) then
5012 SS_Allocator
:= Heap_Allocator
;
5013 Heap_Allocator
:= Make_Null
(Loc
);
5014 Pool_Allocator
:= Make_Null
(Loc
);
5016 -- Otherwise the heap and pool allocators may be needed,
5017 -- so we make another allocator for secondary stack
5021 SS_Allocator
:= New_Copy_Tree
(Heap_Allocator
);
5023 -- The heap and pool allocators are marked as
5024 -- Comes_From_Source since they correspond to an
5025 -- explicit user-written allocator (that is, it will
5026 -- only be executed on behalf of callers that call the
5027 -- function as initialization for such an allocator).
5028 -- Prevents errors when No_Implicit_Heap_Allocations
5031 Set_Comes_From_Source
(Heap_Allocator
, True);
5032 Set_Comes_From_Source
(Pool_Allocator
, True);
5035 -- The allocator is returned on the secondary stack.
5037 Set_Storage_Pool
(SS_Allocator
, RTE
(RE_SS_Pool
));
5038 Set_Procedure_To_Call
5039 (SS_Allocator
, RTE
(RE_SS_Allocate
));
5041 -- The allocator is returned on the secondary stack,
5042 -- so indicate that the function return, as well as
5043 -- all blocks that encloses the allocator, must not
5044 -- release it. The flags must be set now because
5045 -- the decision to use the secondary stack is done
5046 -- very late in the course of expanding the return
5047 -- statement, past the point where these flags are
5050 Set_Uses_Sec_Stack
(Func_Id
);
5051 Set_Uses_Sec_Stack
(Return_Statement_Entity
(N
));
5052 Set_Sec_Stack_Needed_For_Return
5053 (Return_Statement_Entity
(N
));
5054 Set_Enclosing_Sec_Stack_Return
(N
);
5056 -- Create an if statement to test the BIP_Alloc_Form
5057 -- formal and initialize the access object to either the
5058 -- BIP_Object_Access formal (BIP_Alloc_Form =
5059 -- Caller_Allocation), the result of allocating the
5060 -- object in the secondary stack (BIP_Alloc_Form =
5061 -- Secondary_Stack), or else an allocator to create the
5062 -- return object in the heap or user-defined pool
5063 -- (BIP_Alloc_Form = Global_Heap or User_Storage_Pool).
5065 -- ??? An unchecked type conversion must be made in the
5066 -- case of assigning the access object formal to the
5067 -- local access object, because a normal conversion would
5068 -- be illegal in some cases (such as converting access-
5069 -- to-unconstrained to access-to-constrained), but the
5070 -- the unchecked conversion will presumably fail to work
5071 -- right in just such cases. It's not clear at all how to
5075 Make_If_Statement
(Loc
,
5079 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5081 Make_Integer_Literal
(Loc
,
5082 UI_From_Int
(BIP_Allocation_Form
'Pos
5083 (Caller_Allocation
)))),
5085 Then_Statements
=> New_List
(
5086 Make_Assignment_Statement
(Loc
,
5088 New_Occurrence_Of
(Alloc_Obj_Id
, Loc
),
5090 Make_Unchecked_Type_Conversion
(Loc
,
5092 New_Occurrence_Of
(Ref_Type
, Loc
),
5094 New_Occurrence_Of
(Obj_Acc_Formal
, Loc
)))),
5096 Elsif_Parts
=> New_List
(
5097 Make_Elsif_Part
(Loc
,
5101 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5103 Make_Integer_Literal
(Loc
,
5104 UI_From_Int
(BIP_Allocation_Form
'Pos
5105 (Secondary_Stack
)))),
5107 Then_Statements
=> New_List
(
5108 Make_Assignment_Statement
(Loc
,
5110 New_Occurrence_Of
(Alloc_Obj_Id
, Loc
),
5111 Expression
=> SS_Allocator
))),
5113 Make_Elsif_Part
(Loc
,
5117 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5119 Make_Integer_Literal
(Loc
,
5120 UI_From_Int
(BIP_Allocation_Form
'Pos
5123 Then_Statements
=> New_List
(
5124 Build_Heap_Allocator
5125 (Temp_Id
=> Alloc_Obj_Id
,
5126 Temp_Typ
=> Ref_Type
,
5128 Ret_Typ
=> Ret_Obj_Typ
,
5129 Alloc_Expr
=> Heap_Allocator
)))),
5131 Else_Statements
=> New_List
(
5133 Build_Heap_Allocator
5134 (Temp_Id
=> Alloc_Obj_Id
,
5135 Temp_Typ
=> Ref_Type
,
5137 Ret_Typ
=> Ret_Obj_Typ
,
5138 Alloc_Expr
=> Pool_Allocator
)));
5140 -- If a separate initialization assignment was created
5141 -- earlier, append that following the assignment of the
5142 -- implicit access formal to the access object, to ensure
5143 -- that the return object is initialized in that case. In
5144 -- this situation, the target of the assignment must be
5145 -- rewritten to denote a dereference of the access to the
5146 -- return object passed in by the caller.
5148 if Present
(Init_Assignment
) then
5149 Rewrite
(Name
(Init_Assignment
),
5150 Make_Explicit_Dereference
(Loc
,
5151 Prefix
=> New_Occurrence_Of
(Alloc_Obj_Id
, Loc
)));
5153 Set_Etype
(Name
(Init_Assignment
), Etype
(Ret_Obj_Id
));
5156 (Then_Statements
(Alloc_If_Stmt
), Init_Assignment
);
5159 Insert_Before
(Ret_Obj_Decl
, Alloc_If_Stmt
);
5161 -- Remember the local access object for use in the
5162 -- dereference of the renaming created below.
5164 Obj_Acc_Formal
:= Alloc_Obj_Id
;
5168 -- Replace the return object declaration with a renaming of a
5169 -- dereference of the access value designating the return
5173 Make_Explicit_Dereference
(Loc
,
5174 Prefix
=> New_Occurrence_Of
(Obj_Acc_Formal
, Loc
));
5176 Rewrite
(Ret_Obj_Decl
,
5177 Make_Object_Renaming_Declaration
(Loc
,
5178 Defining_Identifier
=> Ret_Obj_Id
,
5179 Access_Definition
=> Empty
,
5180 Subtype_Mark
=> New_Occurrence_Of
(Ret_Obj_Typ
, Loc
),
5181 Name
=> Obj_Acc_Deref
));
5183 Set_Renamed_Object
(Ret_Obj_Id
, Obj_Acc_Deref
);
5187 -- Case where we do not build a block
5190 -- We're about to drop Return_Object_Declarations on the floor, so
5191 -- we need to insert it, in case it got expanded into useful code.
5192 -- Remove side effects from expression, which may be duplicated in
5193 -- subsequent checks (see Expand_Simple_Function_Return).
5195 Insert_List_Before
(N
, Return_Object_Declarations
(N
));
5196 Remove_Side_Effects
(Exp
);
5198 -- Build simple_return_statement that returns the expression directly
5200 Return_Stmt
:= Make_Simple_Return_Statement
(Loc
, Expression
=> Exp
);
5201 Result
:= Return_Stmt
;
5204 -- Set the flag to prevent infinite recursion
5206 Set_Comes_From_Extended_Return_Statement
(Return_Stmt
);
5208 Rewrite
(N
, Result
);
5210 end Expand_N_Extended_Return_Statement
;
5212 ----------------------------
5213 -- Expand_N_Function_Call --
5214 ----------------------------
5216 procedure Expand_N_Function_Call
(N
: Node_Id
) is
5219 end Expand_N_Function_Call
;
5221 ---------------------------------------
5222 -- Expand_N_Procedure_Call_Statement --
5223 ---------------------------------------
5225 procedure Expand_N_Procedure_Call_Statement
(N
: Node_Id
) is
5228 end Expand_N_Procedure_Call_Statement
;
5230 --------------------------------------
5231 -- Expand_N_Simple_Return_Statement --
5232 --------------------------------------
5234 procedure Expand_N_Simple_Return_Statement
(N
: Node_Id
) is
5236 -- Defend against previous errors (i.e. the return statement calls a
5237 -- function that is not available in configurable runtime).
5239 if Present
(Expression
(N
))
5240 and then Nkind
(Expression
(N
)) = N_Empty
5242 Check_Error_Detected
;
5246 -- Distinguish the function and non-function cases:
5248 case Ekind
(Return_Applies_To
(Return_Statement_Entity
(N
))) is
5250 | E_Generic_Function
5252 Expand_Simple_Function_Return
(N
);
5256 | E_Generic_Procedure
5258 | E_Return_Statement
5260 Expand_Non_Function_Return
(N
);
5263 raise Program_Error
;
5267 when RE_Not_Available
=>
5269 end Expand_N_Simple_Return_Statement
;
5271 ------------------------------
5272 -- Expand_N_Subprogram_Body --
5273 ------------------------------
5275 -- Add poll call if ATC polling is enabled, unless the body will be inlined
5278 -- Add dummy push/pop label nodes at start and end to clear any local
5279 -- exception indications if local-exception-to-goto optimization is active.
5281 -- Add return statement if last statement in body is not a return statement
5282 -- (this makes things easier on Gigi which does not want to have to handle
5283 -- a missing return).
5285 -- Add call to Activate_Tasks if body is a task activator
5287 -- Deal with possible detection of infinite recursion
5289 -- Eliminate body completely if convention stubbed
5291 -- Encode entity names within body, since we will not need to reference
5292 -- these entities any longer in the front end.
5294 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
5296 -- Reset Pure indication if any parameter has root type System.Address
5297 -- or has any parameters of limited types, where limited means that the
5298 -- run-time view is limited (i.e. the full type is limited).
5302 procedure Expand_N_Subprogram_Body
(N
: Node_Id
) is
5303 Body_Id
: constant Entity_Id
:= Defining_Entity
(N
);
5304 HSS
: constant Node_Id
:= Handled_Statement_Sequence
(N
);
5305 Loc
: constant Source_Ptr
:= Sloc
(N
);
5307 procedure Add_Return
(Spec_Id
: Entity_Id
; Stmts
: List_Id
);
5308 -- Append a return statement to the statement sequence Stmts if the last
5309 -- statement is not already a return or a goto statement. Note that the
5310 -- latter test is not critical, it does not matter if we add a few extra
5311 -- returns, since they get eliminated anyway later on. Spec_Id denotes
5312 -- the corresponding spec of the subprogram body.
5318 procedure Add_Return
(Spec_Id
: Entity_Id
; Stmts
: List_Id
) is
5319 Last_Stmt
: Node_Id
;
5324 -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
5325 -- not relevant in this context since they are not executable.
5327 Last_Stmt
:= Last
(Stmts
);
5328 while Nkind
(Last_Stmt
) in N_Pop_xxx_Label
loop
5332 -- Now insert return unless last statement is a transfer
5334 if not Is_Transfer
(Last_Stmt
) then
5336 -- The source location for the return is the end label of the
5337 -- procedure if present. Otherwise use the sloc of the last
5338 -- statement in the list. If the list comes from a generated
5339 -- exception handler and we are not debugging generated code,
5340 -- all the statements within the handler are made invisible
5343 if Nkind
(Parent
(Stmts
)) = N_Exception_Handler
5344 and then not Comes_From_Source
(Parent
(Stmts
))
5346 Loc
:= Sloc
(Last_Stmt
);
5347 elsif Present
(End_Label
(HSS
)) then
5348 Loc
:= Sloc
(End_Label
(HSS
));
5350 Loc
:= Sloc
(Last_Stmt
);
5353 -- Append return statement, and set analyzed manually. We can't
5354 -- call Analyze on this return since the scope is wrong.
5356 -- Note: it almost works to push the scope and then do the Analyze
5357 -- call, but something goes wrong in some weird cases and it is
5358 -- not worth worrying about ???
5360 Stmt
:= Make_Simple_Return_Statement
(Loc
);
5362 -- The return statement is handled properly, and the call to the
5363 -- postcondition, inserted below, does not require information
5364 -- from the body either. However, that call is analyzed in the
5365 -- enclosing scope, and an elaboration check might improperly be
5366 -- added to it. A guard in Sem_Elab is needed to prevent that
5367 -- spurious check, see Check_Elab_Call.
5369 Append_To
(Stmts
, Stmt
);
5370 Set_Analyzed
(Stmt
);
5372 -- Call the _Postconditions procedure if the related subprogram
5373 -- has contract assertions that need to be verified on exit.
5375 if Ekind
(Spec_Id
) = E_Procedure
5376 and then Present
(Postconditions_Proc
(Spec_Id
))
5378 Insert_Action
(Stmt
,
5379 Make_Procedure_Call_Statement
(Loc
,
5381 New_Occurrence_Of
(Postconditions_Proc
(Spec_Id
), Loc
)));
5390 Spec_Id
: Entity_Id
;
5392 -- Start of processing for Expand_N_Subprogram_Body
5395 if Present
(Corresponding_Spec
(N
)) then
5396 Spec_Id
:= Corresponding_Spec
(N
);
5401 -- If this is a Pure function which has any parameters whose root type
5402 -- is System.Address, reset the Pure indication.
5403 -- This check is also performed when the subprogram is frozen, but we
5404 -- repeat it on the body so that the indication is consistent, and so
5405 -- it applies as well to bodies without separate specifications.
5407 if Is_Pure
(Spec_Id
)
5408 and then Is_Subprogram
(Spec_Id
)
5409 and then not Has_Pragma_Pure_Function
(Spec_Id
)
5411 Check_Function_With_Address_Parameter
(Spec_Id
);
5413 if Spec_Id
/= Body_Id
then
5414 Set_Is_Pure
(Body_Id
, Is_Pure
(Spec_Id
));
5418 -- Set L to either the list of declarations if present, or to the list
5419 -- of statements if no declarations are present. This is used to insert
5420 -- new stuff at the start.
5422 if Is_Non_Empty_List
(Declarations
(N
)) then
5423 L
:= Declarations
(N
);
5425 L
:= Statements
(HSS
);
5428 -- If local-exception-to-goto optimization active, insert dummy push
5429 -- statements at start, and dummy pop statements at end, but inhibit
5430 -- this if we have No_Exception_Handlers, since they are useless and
5431 -- intefere with analysis, e.g. by codepeer.
5433 if (Debug_Flag_Dot_G
5434 or else Restriction_Active
(No_Exception_Propagation
))
5435 and then not Restriction_Active
(No_Exception_Handlers
)
5436 and then not CodePeer_Mode
5437 and then Is_Non_Empty_List
(L
)
5440 FS
: constant Node_Id
:= First
(L
);
5441 FL
: constant Source_Ptr
:= Sloc
(FS
);
5446 -- LS points to either last statement, if statements are present
5447 -- or to the last declaration if there are no statements present.
5448 -- It is the node after which the pop's are generated.
5450 if Is_Non_Empty_List
(Statements
(HSS
)) then
5451 LS
:= Last
(Statements
(HSS
));
5458 Insert_List_Before_And_Analyze
(FS
, New_List
(
5459 Make_Push_Constraint_Error_Label
(FL
),
5460 Make_Push_Program_Error_Label
(FL
),
5461 Make_Push_Storage_Error_Label
(FL
)));
5463 Insert_List_After_And_Analyze
(LS
, New_List
(
5464 Make_Pop_Constraint_Error_Label
(LL
),
5465 Make_Pop_Program_Error_Label
(LL
),
5466 Make_Pop_Storage_Error_Label
(LL
)));
5470 -- Need poll on entry to subprogram if polling enabled. We only do this
5471 -- for non-empty subprograms, since it does not seem necessary to poll
5472 -- for a dummy null subprogram.
5474 if Is_Non_Empty_List
(L
) then
5476 -- Do not add a polling call if the subprogram is to be inlined by
5477 -- the back-end, to avoid repeated calls with multiple inlinings.
5479 if Is_Inlined
(Spec_Id
)
5480 and then Front_End_Inlining
5481 and then Optimization_Level
> 1
5485 Generate_Poll_Call
(First
(L
));
5489 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
5491 if Init_Or_Norm_Scalars
and then Is_Subprogram
(Spec_Id
) then
5497 -- Loop through formals
5499 F
:= First_Formal
(Spec_Id
);
5500 while Present
(F
) loop
5501 if Is_Scalar_Type
(Etype
(F
))
5502 and then Ekind
(F
) = E_Out_Parameter
5504 Check_Restriction
(No_Default_Initialization
, F
);
5506 -- Insert the initialization. We turn off validity checks
5507 -- for this assignment, since we do not want any check on
5508 -- the initial value itself (which may well be invalid).
5509 -- Predicate checks are disabled as well (RM 6.4.1 (13/3))
5512 Make_Assignment_Statement
(Loc
,
5513 Name
=> New_Occurrence_Of
(F
, Loc
),
5514 Expression
=> Get_Simple_Init_Val
(Etype
(F
), N
));
5515 Set_Suppress_Assignment_Checks
(A
);
5517 Insert_Before_And_Analyze
(First
(L
),
5518 A
, Suppress
=> Validity_Check
);
5526 -- Clear out statement list for stubbed procedure
5528 if Present
(Corresponding_Spec
(N
)) then
5529 Set_Elaboration_Flag
(N
, Spec_Id
);
5531 if Convention
(Spec_Id
) = Convention_Stubbed
5532 or else Is_Eliminated
(Spec_Id
)
5534 Set_Declarations
(N
, Empty_List
);
5535 Set_Handled_Statement_Sequence
(N
,
5536 Make_Handled_Sequence_Of_Statements
(Loc
,
5537 Statements
=> New_List
(Make_Null_Statement
(Loc
))));
5543 -- Create a set of discriminals for the next protected subprogram body
5545 if Is_List_Member
(N
)
5546 and then Present
(Parent
(List_Containing
(N
)))
5547 and then Nkind
(Parent
(List_Containing
(N
))) = N_Protected_Body
5548 and then Present
(Next_Protected_Operation
(N
))
5550 Set_Discriminals
(Parent
(Base_Type
(Scope
(Spec_Id
))));
5553 -- Returns_By_Ref flag is normally set when the subprogram is frozen but
5554 -- subprograms with no specs are not frozen.
5557 Typ
: constant Entity_Id
:= Etype
(Spec_Id
);
5558 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
5561 if Is_Limited_View
(Typ
) then
5562 Set_Returns_By_Ref
(Spec_Id
);
5564 elsif Present
(Utyp
) and then CW_Or_Has_Controlled_Part
(Utyp
) then
5565 Set_Returns_By_Ref
(Spec_Id
);
5569 -- For a procedure, we add a return for all possible syntactic ends of
5572 if Ekind_In
(Spec_Id
, E_Procedure
, E_Generic_Procedure
) then
5573 Add_Return
(Spec_Id
, Statements
(HSS
));
5575 if Present
(Exception_Handlers
(HSS
)) then
5576 Except_H
:= First_Non_Pragma
(Exception_Handlers
(HSS
));
5577 while Present
(Except_H
) loop
5578 Add_Return
(Spec_Id
, Statements
(Except_H
));
5579 Next_Non_Pragma
(Except_H
);
5583 -- For a function, we must deal with the case where there is at least
5584 -- one missing return. What we do is to wrap the entire body of the
5585 -- function in a block:
5598 -- raise Program_Error;
5601 -- This approach is necessary because the raise must be signalled to the
5602 -- caller, not handled by any local handler (RM 6.4(11)).
5604 -- Note: we do not need to analyze the constructed sequence here, since
5605 -- it has no handler, and an attempt to analyze the handled statement
5606 -- sequence twice is risky in various ways (e.g. the issue of expanding
5607 -- cleanup actions twice).
5609 elsif Has_Missing_Return
(Spec_Id
) then
5611 Hloc
: constant Source_Ptr
:= Sloc
(HSS
);
5612 Blok
: constant Node_Id
:=
5613 Make_Block_Statement
(Hloc
,
5614 Handled_Statement_Sequence
=> HSS
);
5615 Rais
: constant Node_Id
:=
5616 Make_Raise_Program_Error
(Hloc
,
5617 Reason
=> PE_Missing_Return
);
5620 Set_Handled_Statement_Sequence
(N
,
5621 Make_Handled_Sequence_Of_Statements
(Hloc
,
5622 Statements
=> New_List
(Blok
, Rais
)));
5624 Push_Scope
(Spec_Id
);
5631 -- If subprogram contains a parameterless recursive call, then we may
5632 -- have an infinite recursion, so see if we can generate code to check
5633 -- for this possibility if storage checks are not suppressed.
5635 if Ekind
(Spec_Id
) = E_Procedure
5636 and then Has_Recursive_Call
(Spec_Id
)
5637 and then not Storage_Checks_Suppressed
(Spec_Id
)
5639 Detect_Infinite_Recursion
(N
, Spec_Id
);
5642 -- Set to encode entity names in package body before gigi is called
5644 Qualify_Entity_Names
(N
);
5646 -- If the body belongs to a nonabstract library-level source primitive
5647 -- of a tagged type, install an elaboration check which ensures that a
5648 -- dispatching call targeting the primitive will not execute the body
5649 -- without it being previously elaborated.
5651 Install_Primitive_Elaboration_Check
(N
);
5652 end Expand_N_Subprogram_Body
;
5654 -----------------------------------
5655 -- Expand_N_Subprogram_Body_Stub --
5656 -----------------------------------
5658 procedure Expand_N_Subprogram_Body_Stub
(N
: Node_Id
) is
5662 if Present
(Corresponding_Body
(N
)) then
5663 Bod
:= Unit_Declaration_Node
(Corresponding_Body
(N
));
5665 -- The body may have been expanded already when it is analyzed
5666 -- through the subunit node. Do no expand again: it interferes
5667 -- with the construction of unnesting tables when generating C.
5669 if not Analyzed
(Bod
) then
5670 Expand_N_Subprogram_Body
(Bod
);
5673 -- Add full qualification to entities that may be created late
5674 -- during unnesting.
5676 Qualify_Entity_Names
(N
);
5678 end Expand_N_Subprogram_Body_Stub
;
5680 -------------------------------------
5681 -- Expand_N_Subprogram_Declaration --
5682 -------------------------------------
5684 -- If the declaration appears within a protected body, it is a private
5685 -- operation of the protected type. We must create the corresponding
5686 -- protected subprogram an associated formals. For a normal protected
5687 -- operation, this is done when expanding the protected type declaration.
5689 -- If the declaration is for a null procedure, emit null body
5691 procedure Expand_N_Subprogram_Declaration
(N
: Node_Id
) is
5692 Loc
: constant Source_Ptr
:= Sloc
(N
);
5693 Subp
: constant Entity_Id
:= Defining_Entity
(N
);
5697 Scop
: constant Entity_Id
:= Scope
(Subp
);
5699 Prot_Decl
: Node_Id
;
5700 Prot_Id
: Entity_Id
;
5702 -- Start of processing for Expand_N_Subprogram_Declaration
5705 -- In SPARK, subprogram declarations are only allowed in package
5708 if Nkind
(Parent
(N
)) /= N_Package_Specification
then
5709 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
5710 Check_SPARK_05_Restriction
5711 ("subprogram declaration is not a library item", N
);
5713 elsif Present
(Next
(N
))
5714 and then Nkind
(Next
(N
)) = N_Pragma
5715 and then Get_Pragma_Id
(Next
(N
)) = Pragma_Import
5717 -- In SPARK, subprogram declarations are also permitted in
5718 -- declarative parts when immediately followed by a corresponding
5719 -- pragma Import. We only check here that there is some pragma
5724 Check_SPARK_05_Restriction
5725 ("subprogram declaration is not allowed here", N
);
5729 -- Deal with case of protected subprogram. Do not generate protected
5730 -- operation if operation is flagged as eliminated.
5732 if Is_List_Member
(N
)
5733 and then Present
(Parent
(List_Containing
(N
)))
5734 and then Nkind
(Parent
(List_Containing
(N
))) = N_Protected_Body
5735 and then Is_Protected_Type
(Scop
)
5737 if No
(Protected_Body_Subprogram
(Subp
))
5738 and then not Is_Eliminated
(Subp
)
5741 Make_Subprogram_Declaration
(Loc
,
5743 Build_Protected_Sub_Specification
5744 (N
, Scop
, Unprotected_Mode
));
5746 -- The protected subprogram is declared outside of the protected
5747 -- body. Given that the body has frozen all entities so far, we
5748 -- analyze the subprogram and perform freezing actions explicitly.
5749 -- including the generation of an explicit freeze node, to ensure
5750 -- that gigi has the proper order of elaboration.
5751 -- If the body is a subunit, the insertion point is before the
5752 -- stub in the parent.
5754 Prot_Bod
:= Parent
(List_Containing
(N
));
5756 if Nkind
(Parent
(Prot_Bod
)) = N_Subunit
then
5757 Prot_Bod
:= Corresponding_Stub
(Parent
(Prot_Bod
));
5760 Insert_Before
(Prot_Bod
, Prot_Decl
);
5761 Prot_Id
:= Defining_Unit_Name
(Specification
(Prot_Decl
));
5762 Set_Has_Delayed_Freeze
(Prot_Id
);
5764 Push_Scope
(Scope
(Scop
));
5765 Analyze
(Prot_Decl
);
5766 Freeze_Before
(N
, Prot_Id
);
5767 Set_Protected_Body_Subprogram
(Subp
, Prot_Id
);
5769 -- Create protected operation as well. Even though the operation
5770 -- is only accessible within the body, it is possible to make it
5771 -- available outside of the protected object by using 'Access to
5772 -- provide a callback, so build protected version in all cases.
5775 Make_Subprogram_Declaration
(Loc
,
5777 Build_Protected_Sub_Specification
(N
, Scop
, Protected_Mode
));
5778 Insert_Before
(Prot_Bod
, Prot_Decl
);
5779 Analyze
(Prot_Decl
);
5784 -- Ada 2005 (AI-348): Generate body for a null procedure. In most
5785 -- cases this is superfluous because calls to it will be automatically
5786 -- inlined, but we definitely need the body if preconditions for the
5787 -- procedure are present, or if performing coverage analysis.
5789 elsif Nkind
(Specification
(N
)) = N_Procedure_Specification
5790 and then Null_Present
(Specification
(N
))
5793 Bod
: constant Node_Id
:= Body_To_Inline
(N
);
5796 Set_Has_Completion
(Subp
, False);
5797 Append_Freeze_Action
(Subp
, Bod
);
5799 -- The body now contains raise statements, so calls to it will
5802 Set_Is_Inlined
(Subp
, False);
5806 -- When generating C code, transform a function that returns a
5807 -- constrained array type into a procedure with an out parameter
5808 -- that carries the return value.
5810 -- We skip this transformation for unchecked conversions, since they
5811 -- are not needed by the C generator (and this also produces cleaner
5814 if Modify_Tree_For_C
5815 and then Nkind
(Specification
(N
)) = N_Function_Specification
5816 and then Is_Array_Type
(Etype
(Subp
))
5817 and then Is_Constrained
(Etype
(Subp
))
5818 and then not Is_Unchecked_Conversion_Instance
(Subp
)
5820 Build_Procedure_Form
(N
);
5822 end Expand_N_Subprogram_Declaration
;
5824 --------------------------------
5825 -- Expand_Non_Function_Return --
5826 --------------------------------
5828 procedure Expand_Non_Function_Return
(N
: Node_Id
) is
5829 pragma Assert
(No
(Expression
(N
)));
5831 Loc
: constant Source_Ptr
:= Sloc
(N
);
5832 Scope_Id
: Entity_Id
:= Return_Applies_To
(Return_Statement_Entity
(N
));
5833 Kind
: constant Entity_Kind
:= Ekind
(Scope_Id
);
5836 Goto_Stat
: Node_Id
;
5840 -- Call the _Postconditions procedure if the related subprogram has
5841 -- contract assertions that need to be verified on exit.
5843 if Ekind_In
(Scope_Id
, E_Entry
, E_Entry_Family
, E_Procedure
)
5844 and then Present
(Postconditions_Proc
(Scope_Id
))
5847 Make_Procedure_Call_Statement
(Loc
,
5848 Name
=> New_Occurrence_Of
(Postconditions_Proc
(Scope_Id
), Loc
)));
5851 -- If it is a return from a procedure do no extra steps
5853 if Kind
= E_Procedure
or else Kind
= E_Generic_Procedure
then
5856 -- If it is a nested return within an extended one, replace it with a
5857 -- return of the previously declared return object.
5859 elsif Kind
= E_Return_Statement
then
5861 Make_Simple_Return_Statement
(Loc
,
5863 New_Occurrence_Of
(First_Entity
(Scope_Id
), Loc
)));
5864 Set_Comes_From_Extended_Return_Statement
(N
);
5865 Set_Return_Statement_Entity
(N
, Scope_Id
);
5866 Expand_Simple_Function_Return
(N
);
5870 pragma Assert
(Is_Entry
(Scope_Id
));
5872 -- Look at the enclosing block to see whether the return is from an
5873 -- accept statement or an entry body.
5875 for J
in reverse 0 .. Scope_Stack
.Last
loop
5876 Scope_Id
:= Scope_Stack
.Table
(J
).Entity
;
5877 exit when Is_Concurrent_Type
(Scope_Id
);
5880 -- If it is a return from accept statement it is expanded as call to
5881 -- RTS Complete_Rendezvous and a goto to the end of the accept body.
5883 -- (cf : Expand_N_Accept_Statement, Expand_N_Selective_Accept,
5884 -- Expand_N_Accept_Alternative in exp_ch9.adb)
5886 if Is_Task_Type
(Scope_Id
) then
5889 Make_Procedure_Call_Statement
(Loc
,
5890 Name
=> New_Occurrence_Of
(RTE
(RE_Complete_Rendezvous
), Loc
));
5891 Insert_Before
(N
, Call
);
5892 -- why not insert actions here???
5895 Acc_Stat
:= Parent
(N
);
5896 while Nkind
(Acc_Stat
) /= N_Accept_Statement
loop
5897 Acc_Stat
:= Parent
(Acc_Stat
);
5900 Lab_Node
:= Last
(Statements
5901 (Handled_Statement_Sequence
(Acc_Stat
)));
5903 Goto_Stat
:= Make_Goto_Statement
(Loc
,
5904 Name
=> New_Occurrence_Of
5905 (Entity
(Identifier
(Lab_Node
)), Loc
));
5907 Set_Analyzed
(Goto_Stat
);
5909 Rewrite
(N
, Goto_Stat
);
5912 -- If it is a return from an entry body, put a Complete_Entry_Body call
5913 -- in front of the return.
5915 elsif Is_Protected_Type
(Scope_Id
) then
5917 Make_Procedure_Call_Statement
(Loc
,
5919 New_Occurrence_Of
(RTE
(RE_Complete_Entry_Body
), Loc
),
5920 Parameter_Associations
=> New_List
(
5921 Make_Attribute_Reference
(Loc
,
5924 (Find_Protection_Object
(Current_Scope
), Loc
),
5925 Attribute_Name
=> Name_Unchecked_Access
)));
5927 Insert_Before
(N
, Call
);
5930 end Expand_Non_Function_Return
;
5932 ---------------------------------------
5933 -- Expand_Protected_Object_Reference --
5934 ---------------------------------------
5936 function Expand_Protected_Object_Reference
5938 Scop
: Entity_Id
) return Node_Id
5940 Loc
: constant Source_Ptr
:= Sloc
(N
);
5947 Rec
:= Make_Identifier
(Loc
, Name_uObject
);
5948 Set_Etype
(Rec
, Corresponding_Record_Type
(Scop
));
5950 -- Find enclosing protected operation, and retrieve its first parameter,
5951 -- which denotes the enclosing protected object. If the enclosing
5952 -- operation is an entry, we are immediately within the protected body,
5953 -- and we can retrieve the object from the service entries procedure. A
5954 -- barrier function has the same signature as an entry. A barrier
5955 -- function is compiled within the protected object, but unlike
5956 -- protected operations its never needs locks, so that its protected
5957 -- body subprogram points to itself.
5959 Proc
:= Current_Scope
;
5960 while Present
(Proc
)
5961 and then Scope
(Proc
) /= Scop
5963 Proc
:= Scope
(Proc
);
5966 Corr
:= Protected_Body_Subprogram
(Proc
);
5970 -- Previous error left expansion incomplete.
5971 -- Nothing to do on this call.
5978 (First
(Parameter_Specifications
(Parent
(Corr
))));
5980 if Is_Subprogram
(Proc
) and then Proc
/= Corr
then
5982 -- Protected function or procedure
5984 Set_Entity
(Rec
, Param
);
5986 -- Rec is a reference to an entity which will not be in scope when
5987 -- the call is reanalyzed, and needs no further analysis.
5992 -- Entry or barrier function for entry body. The first parameter of
5993 -- the entry body procedure is pointer to the object. We create a
5994 -- local variable of the proper type, duplicating what is done to
5995 -- define _object later on.
5999 Obj_Ptr
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
6003 Make_Full_Type_Declaration
(Loc
,
6004 Defining_Identifier
=> Obj_Ptr
,
6006 Make_Access_To_Object_Definition
(Loc
,
6007 Subtype_Indication
=>
6009 (Corresponding_Record_Type
(Scop
), Loc
))));
6011 Insert_Actions
(N
, Decls
);
6012 Freeze_Before
(N
, Obj_Ptr
);
6015 Make_Explicit_Dereference
(Loc
,
6017 Unchecked_Convert_To
(Obj_Ptr
,
6018 New_Occurrence_Of
(Param
, Loc
)));
6020 -- Analyze new actual. Other actuals in calls are already analyzed
6021 -- and the list of actuals is not reanalyzed after rewriting.
6023 Set_Parent
(Rec
, N
);
6029 end Expand_Protected_Object_Reference
;
6031 --------------------------------------
6032 -- Expand_Protected_Subprogram_Call --
6033 --------------------------------------
6035 procedure Expand_Protected_Subprogram_Call
6042 procedure Expand_Internal_Init_Call
;
6043 -- A call to an operation of the type may occur in the initialization
6044 -- of a private component. In that case the prefix of the call is an
6045 -- entity name and the call is treated as internal even though it
6046 -- appears in code outside of the protected type.
6048 procedure Freeze_Called_Function
;
6049 -- If it is a function call it can appear in elaboration code and
6050 -- the called entity must be frozen before the call. This must be
6051 -- done before the call is expanded, as the expansion may rewrite it
6052 -- to something other than a call (e.g. a temporary initialized in a
6053 -- transient block).
6055 -------------------------------
6056 -- Expand_Internal_Init_Call --
6057 -------------------------------
6059 procedure Expand_Internal_Init_Call
is
6061 -- If the context is a protected object (rather than a protected
6062 -- type) the call itself is bound to raise program_error because
6063 -- the protected body will not have been elaborated yet. This is
6064 -- diagnosed subsequently in Sem_Elab.
6066 Freeze_Called_Function
;
6068 -- The target of the internal call is the first formal of the
6069 -- enclosing initialization procedure.
6071 Rec
:= New_Occurrence_Of
(First_Formal
(Current_Scope
), Sloc
(N
));
6072 Build_Protected_Subprogram_Call
(N
,
6077 Resolve
(N
, Etype
(Subp
));
6078 end Expand_Internal_Init_Call
;
6080 ----------------------------
6081 -- Freeze_Called_Function --
6082 ----------------------------
6084 procedure Freeze_Called_Function
is
6086 if Ekind
(Subp
) = E_Function
then
6087 Freeze_Expression
(Name
(N
));
6089 end Freeze_Called_Function
;
6091 -- Start of processing for Expand_Protected_Subprogram_Call
6094 -- If the protected object is not an enclosing scope, this is an inter-
6095 -- object function call. Inter-object procedure calls are expanded by
6096 -- Exp_Ch9.Build_Simple_Entry_Call. The call is intra-object only if the
6097 -- subprogram being called is in the protected body being compiled, and
6098 -- if the protected object in the call is statically the enclosing type.
6099 -- The object may be a component of some other data structure, in which
6100 -- case this must be handled as an inter-object call.
6102 if not In_Open_Scopes
(Scop
)
6103 or else Is_Entry_Wrapper
(Current_Scope
)
6104 or else not Is_Entity_Name
(Name
(N
))
6106 if Nkind
(Name
(N
)) = N_Selected_Component
then
6107 Rec
:= Prefix
(Name
(N
));
6109 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
6110 Rec
:= Prefix
(Prefix
(Name
(N
)));
6112 -- If this is a call within an entry wrapper, it appears within a
6113 -- precondition that calls another primitive of the synchronized
6114 -- type. The target object of the call is the first actual on the
6115 -- wrapper. Note that this is an external call, because the wrapper
6116 -- is called outside of the synchronized object. This means that
6117 -- an entry call to an entry with preconditions involves two
6118 -- synchronized operations.
6120 elsif Ekind
(Current_Scope
) = E_Procedure
6121 and then Is_Entry_Wrapper
(Current_Scope
)
6123 Rec
:= New_Occurrence_Of
(First_Entity
(Current_Scope
), Sloc
(N
));
6126 -- If the context is the initialization procedure for a protected
6127 -- type, the call is legal because the called entity must be a
6128 -- function of that enclosing type, and this is treated as an
6132 (Is_Entity_Name
(Name
(N
)) and then Inside_Init_Proc
);
6134 Expand_Internal_Init_Call
;
6138 Freeze_Called_Function
;
6139 Build_Protected_Subprogram_Call
(N
,
6140 Name
=> New_Occurrence_Of
(Subp
, Sloc
(N
)),
6141 Rec
=> Convert_Concurrent
(Rec
, Etype
(Rec
)),
6145 Rec
:= Expand_Protected_Object_Reference
(N
, Scop
);
6151 Freeze_Called_Function
;
6152 Build_Protected_Subprogram_Call
(N
,
6158 -- Analyze and resolve the new call. The actuals have already been
6159 -- resolved, but expansion of a function call will add extra actuals
6160 -- if needed. Analysis of a procedure call already includes resolution.
6164 if Ekind
(Subp
) = E_Function
then
6165 Resolve
(N
, Etype
(Subp
));
6167 end Expand_Protected_Subprogram_Call
;
6169 -----------------------------------
6170 -- Expand_Simple_Function_Return --
6171 -----------------------------------
6173 -- The "simple" comes from the syntax rule simple_return_statement. The
6174 -- semantics are not at all simple.
6176 procedure Expand_Simple_Function_Return
(N
: Node_Id
) is
6177 Loc
: constant Source_Ptr
:= Sloc
(N
);
6179 Scope_Id
: constant Entity_Id
:=
6180 Return_Applies_To
(Return_Statement_Entity
(N
));
6181 -- The function we are returning from
6183 R_Type
: constant Entity_Id
:= Etype
(Scope_Id
);
6184 -- The result type of the function
6186 Utyp
: constant Entity_Id
:= Underlying_Type
(R_Type
);
6188 Exp
: Node_Id
:= Expression
(N
);
6189 pragma Assert
(Present
(Exp
));
6191 Exptyp
: constant Entity_Id
:= Etype
(Exp
);
6192 -- The type of the expression (not necessarily the same as R_Type)
6194 Subtype_Ind
: Node_Id
;
6195 -- If the result type of the function is class-wide and the expression
6196 -- has a specific type, then we use the expression's type as the type of
6197 -- the return object. In cases where the expression is an aggregate that
6198 -- is built in place, this avoids the need for an expensive conversion
6199 -- of the return object to the specific type on assignments to the
6200 -- individual components.
6203 if Is_Class_Wide_Type
(R_Type
)
6204 and then not Is_Class_Wide_Type
(Exptyp
)
6205 and then Nkind
(Exp
) /= N_Type_Conversion
6207 Subtype_Ind
:= New_Occurrence_Of
(Exptyp
, Loc
);
6209 Subtype_Ind
:= New_Occurrence_Of
(R_Type
, Loc
);
6211 -- If the result type is class-wide and the expression is a view
6212 -- conversion, the conversion plays no role in the expansion because
6213 -- it does not modify the tag of the object. Remove the conversion
6214 -- altogether to prevent tag overwriting.
6216 if Is_Class_Wide_Type
(R_Type
)
6217 and then not Is_Class_Wide_Type
(Exptyp
)
6218 and then Nkind
(Exp
) = N_Type_Conversion
6220 Exp
:= Expression
(Exp
);
6224 -- For the case of a simple return that does not come from an extended
6225 -- return, in the case of Ada 2005 where we are returning a limited
6226 -- type, we rewrite "return <expression>;" to be:
6228 -- return _anon_ : <return_subtype> := <expression>
6230 -- The expansion produced by Expand_N_Extended_Return_Statement will
6231 -- contain simple return statements (for example, a block containing
6232 -- simple return of the return object), which brings us back here with
6233 -- Comes_From_Extended_Return_Statement set. The reason for the barrier
6234 -- checking for a simple return that does not come from an extended
6235 -- return is to avoid this infinite recursion.
6237 -- The reason for this design is that for Ada 2005 limited returns, we
6238 -- need to reify the return object, so we can build it "in place", and
6239 -- we need a block statement to hang finalization and tasking stuff.
6241 -- ??? In order to avoid disruption, we avoid translating to extended
6242 -- return except in the cases where we really need to (Ada 2005 for
6243 -- inherently limited). We might prefer to do this translation in all
6244 -- cases (except perhaps for the case of Ada 95 inherently limited),
6245 -- in order to fully exercise the Expand_N_Extended_Return_Statement
6246 -- code. This would also allow us to do the build-in-place optimization
6247 -- for efficiency even in cases where it is semantically not required.
6249 -- As before, we check the type of the return expression rather than the
6250 -- return type of the function, because the latter may be a limited
6251 -- class-wide interface type, which is not a limited type, even though
6252 -- the type of the expression may be.
6254 if not Comes_From_Extended_Return_Statement
(N
)
6255 and then Is_Limited_View
(Etype
(Expression
(N
)))
6256 and then Ada_Version
>= Ada_2005
6257 and then not Debug_Flag_Dot_L
6259 -- The functionality of interface thunks is simple and it is always
6260 -- handled by means of simple return statements. This leaves their
6261 -- expansion simple and clean.
6263 and then not Is_Thunk
(Current_Scope
)
6266 Return_Object_Entity
: constant Entity_Id
:=
6267 Make_Temporary
(Loc
, 'R', Exp
);
6269 Obj_Decl
: constant Node_Id
:=
6270 Make_Object_Declaration
(Loc
,
6271 Defining_Identifier
=> Return_Object_Entity
,
6272 Object_Definition
=> Subtype_Ind
,
6275 Ext
: constant Node_Id
:=
6276 Make_Extended_Return_Statement
(Loc
,
6277 Return_Object_Declarations
=> New_List
(Obj_Decl
));
6278 -- Do not perform this high-level optimization if the result type
6279 -- is an interface because the "this" pointer must be displaced.
6288 -- Here we have a simple return statement that is part of the expansion
6289 -- of an extended return statement (either written by the user, or
6290 -- generated by the above code).
6292 -- Always normalize C/Fortran boolean result. This is not always needed,
6293 -- but it seems a good idea to minimize the passing around of non-
6294 -- normalized values, and in any case this handles the processing of
6295 -- barrier functions for protected types, which turn the condition into
6296 -- a return statement.
6298 if Is_Boolean_Type
(Exptyp
)
6299 and then Nonzero_Is_True
(Exptyp
)
6301 Adjust_Condition
(Exp
);
6302 Adjust_Result_Type
(Exp
, Exptyp
);
6305 -- Do validity check if enabled for returns
6307 if Validity_Checks_On
6308 and then Validity_Check_Returns
6313 -- Check the result expression of a scalar function against the subtype
6314 -- of the function by inserting a conversion. This conversion must
6315 -- eventually be performed for other classes of types, but for now it's
6316 -- only done for scalars.
6319 if Is_Scalar_Type
(Exptyp
) then
6320 Rewrite
(Exp
, Convert_To
(R_Type
, Exp
));
6322 -- The expression is resolved to ensure that the conversion gets
6323 -- expanded to generate a possible constraint check.
6325 Analyze_And_Resolve
(Exp
, R_Type
);
6328 -- Deal with returning variable length objects and controlled types
6330 -- Nothing to do if we are returning by reference, or this is not a
6331 -- type that requires special processing (indicated by the fact that
6332 -- it requires a cleanup scope for the secondary stack case).
6334 if Is_Limited_View
(Exptyp
)
6335 or else Is_Limited_Interface
(Exptyp
)
6339 -- No copy needed for thunks returning interface type objects since
6340 -- the object is returned by reference and the maximum functionality
6341 -- required is just to displace the pointer.
6343 elsif Is_Thunk
(Current_Scope
) and then Is_Interface
(Exptyp
) then
6346 -- If the call is within a thunk and the type is a limited view, the
6347 -- backend will eventually see the non-limited view of the type.
6349 elsif Is_Thunk
(Current_Scope
) and then Is_Incomplete_Type
(Exptyp
) then
6352 elsif not Requires_Transient_Scope
(R_Type
) then
6354 -- Mutable records with variable-length components are not returned
6355 -- on the sec-stack, so we need to make sure that the back end will
6356 -- only copy back the size of the actual value, and not the maximum
6357 -- size. We create an actual subtype for this purpose. However we
6358 -- need not do it if the expression is a function call since this
6359 -- will be done in the called function and doing it here too would
6360 -- cause a temporary with maximum size to be created.
6363 Ubt
: constant Entity_Id
:= Underlying_Type
(Base_Type
(Exptyp
));
6367 if Nkind
(Exp
) /= N_Function_Call
6368 and then Has_Discriminants
(Ubt
)
6369 and then not Is_Constrained
(Ubt
)
6370 and then not Has_Unchecked_Union
(Ubt
)
6372 Decl
:= Build_Actual_Subtype
(Ubt
, Exp
);
6373 Ent
:= Defining_Identifier
(Decl
);
6374 Insert_Action
(Exp
, Decl
);
6375 Rewrite
(Exp
, Unchecked_Convert_To
(Ent
, Exp
));
6376 Analyze_And_Resolve
(Exp
);
6380 -- Here if secondary stack is used
6383 -- Prevent the reclamation of the secondary stack by all enclosing
6384 -- blocks and loops as well as the related function; otherwise the
6385 -- result would be reclaimed too early.
6387 Set_Enclosing_Sec_Stack_Return
(N
);
6389 -- Optimize the case where the result is a function call. In this
6390 -- case either the result is already on the secondary stack, or is
6391 -- already being returned with the stack pointer depressed and no
6392 -- further processing is required except to set the By_Ref flag
6393 -- to ensure that gigi does not attempt an extra unnecessary copy.
6394 -- (actually not just unnecessary but harmfully wrong in the case
6395 -- of a controlled type, where gigi does not know how to do a copy).
6396 -- To make up for a gcc 2.8.1 deficiency (???), we perform the copy
6397 -- for array types if the constrained status of the target type is
6398 -- different from that of the expression.
6400 if Requires_Transient_Scope
(Exptyp
)
6402 (not Is_Array_Type
(Exptyp
)
6403 or else Is_Constrained
(Exptyp
) = Is_Constrained
(R_Type
)
6404 or else CW_Or_Has_Controlled_Part
(Utyp
))
6405 and then Nkind
(Exp
) = N_Function_Call
6409 -- Remove side effects from the expression now so that other parts
6410 -- of the expander do not have to reanalyze this node without this
6413 Rewrite
(Exp
, Duplicate_Subexpr_No_Checks
(Exp
));
6415 -- For controlled types, do the allocation on the secondary stack
6416 -- manually in order to call adjust at the right time:
6418 -- type Anon1 is access R_Type;
6419 -- for Anon1'Storage_pool use ss_pool;
6420 -- Anon2 : anon1 := new R_Type'(expr);
6421 -- return Anon2.all;
6423 -- We do the same for classwide types that are not potentially
6424 -- controlled (by the virtue of restriction No_Finalization) because
6425 -- gigi is not able to properly allocate class-wide types.
6427 elsif CW_Or_Has_Controlled_Part
(Utyp
) then
6429 Loc
: constant Source_Ptr
:= Sloc
(N
);
6430 Acc_Typ
: constant Entity_Id
:= Make_Temporary
(Loc
, 'A');
6431 Alloc_Node
: Node_Id
;
6435 Set_Ekind
(Acc_Typ
, E_Access_Type
);
6437 Set_Associated_Storage_Pool
(Acc_Typ
, RTE
(RE_SS_Pool
));
6439 -- This is an allocator for the secondary stack, and it's fine
6440 -- to have Comes_From_Source set False on it, as gigi knows not
6441 -- to flag it as a violation of No_Implicit_Heap_Allocations.
6444 Make_Allocator
(Loc
,
6446 Make_Qualified_Expression
(Loc
,
6447 Subtype_Mark
=> New_Occurrence_Of
(Etype
(Exp
), Loc
),
6448 Expression
=> Relocate_Node
(Exp
)));
6450 -- We do not want discriminant checks on the declaration,
6451 -- given that it gets its value from the allocator.
6453 Set_No_Initialization
(Alloc_Node
);
6455 Temp
:= Make_Temporary
(Loc
, 'R', Alloc_Node
);
6457 Insert_List_Before_And_Analyze
(N
, New_List
(
6458 Make_Full_Type_Declaration
(Loc
,
6459 Defining_Identifier
=> Acc_Typ
,
6461 Make_Access_To_Object_Definition
(Loc
,
6462 Subtype_Indication
=> Subtype_Ind
)),
6464 Make_Object_Declaration
(Loc
,
6465 Defining_Identifier
=> Temp
,
6466 Object_Definition
=> New_Occurrence_Of
(Acc_Typ
, Loc
),
6467 Expression
=> Alloc_Node
)));
6470 Make_Explicit_Dereference
(Loc
,
6471 Prefix
=> New_Occurrence_Of
(Temp
, Loc
)));
6473 -- Ada 2005 (AI-251): If the type of the returned object is
6474 -- an interface then add an implicit type conversion to force
6475 -- displacement of the "this" pointer.
6477 if Is_Interface
(R_Type
) then
6478 Rewrite
(Exp
, Convert_To
(R_Type
, Relocate_Node
(Exp
)));
6481 Analyze_And_Resolve
(Exp
, R_Type
);
6484 -- Otherwise use the gigi mechanism to allocate result on the
6488 Check_Restriction
(No_Secondary_Stack
, N
);
6489 Set_Storage_Pool
(N
, RTE
(RE_SS_Pool
));
6490 Set_Procedure_To_Call
(N
, RTE
(RE_SS_Allocate
));
6494 -- Implement the rules of 6.5(8-10), which require a tag check in
6495 -- the case of a limited tagged return type, and tag reassignment for
6496 -- nonlimited tagged results. These actions are needed when the return
6497 -- type is a specific tagged type and the result expression is a
6498 -- conversion or a formal parameter, because in that case the tag of
6499 -- the expression might differ from the tag of the specific result type.
6501 if Is_Tagged_Type
(Utyp
)
6502 and then not Is_Class_Wide_Type
(Utyp
)
6503 and then (Nkind_In
(Exp
, N_Type_Conversion
,
6504 N_Unchecked_Type_Conversion
)
6505 or else (Is_Entity_Name
(Exp
)
6506 and then Ekind
(Entity
(Exp
)) in Formal_Kind
))
6508 -- When the return type is limited, perform a check that the tag of
6509 -- the result is the same as the tag of the return type.
6511 if Is_Limited_Type
(R_Type
) then
6513 Make_Raise_Constraint_Error
(Loc
,
6517 Make_Selected_Component
(Loc
,
6518 Prefix
=> Duplicate_Subexpr
(Exp
),
6519 Selector_Name
=> Make_Identifier
(Loc
, Name_uTag
)),
6521 Make_Attribute_Reference
(Loc
,
6523 New_Occurrence_Of
(Base_Type
(Utyp
), Loc
),
6524 Attribute_Name
=> Name_Tag
)),
6525 Reason
=> CE_Tag_Check_Failed
));
6527 -- If the result type is a specific nonlimited tagged type, then we
6528 -- have to ensure that the tag of the result is that of the result
6529 -- type. This is handled by making a copy of the expression in
6530 -- the case where it might have a different tag, namely when the
6531 -- expression is a conversion or a formal parameter. We create a new
6532 -- object of the result type and initialize it from the expression,
6533 -- which will implicitly force the tag to be set appropriately.
6537 ExpR
: constant Node_Id
:= Relocate_Node
(Exp
);
6538 Result_Id
: constant Entity_Id
:=
6539 Make_Temporary
(Loc
, 'R', ExpR
);
6540 Result_Exp
: constant Node_Id
:=
6541 New_Occurrence_Of
(Result_Id
, Loc
);
6542 Result_Obj
: constant Node_Id
:=
6543 Make_Object_Declaration
(Loc
,
6544 Defining_Identifier
=> Result_Id
,
6545 Object_Definition
=>
6546 New_Occurrence_Of
(R_Type
, Loc
),
6547 Constant_Present
=> True,
6548 Expression
=> ExpR
);
6551 Set_Assignment_OK
(Result_Obj
);
6552 Insert_Action
(Exp
, Result_Obj
);
6554 Rewrite
(Exp
, Result_Exp
);
6555 Analyze_And_Resolve
(Exp
, R_Type
);
6559 -- Ada 2005 (AI-344): If the result type is class-wide, then insert
6560 -- a check that the level of the return expression's underlying type
6561 -- is not deeper than the level of the master enclosing the function.
6562 -- Always generate the check when the type of the return expression
6563 -- is class-wide, when it's a type conversion, or when it's a formal
6564 -- parameter. Otherwise, suppress the check in the case where the
6565 -- return expression has a specific type whose level is known not to
6566 -- be statically deeper than the function's result type.
6568 -- No runtime check needed in interface thunks since it is performed
6569 -- by the target primitive associated with the thunk.
6571 -- Note: accessibility check is skipped in the VM case, since there
6572 -- does not seem to be any practical way to implement this check.
6574 elsif Ada_Version
>= Ada_2005
6575 and then Tagged_Type_Expansion
6576 and then Is_Class_Wide_Type
(R_Type
)
6577 and then not Is_Thunk
(Current_Scope
)
6578 and then not Scope_Suppress
.Suppress
(Accessibility_Check
)
6580 (Is_Class_Wide_Type
(Etype
(Exp
))
6581 or else Nkind_In
(Exp
, N_Type_Conversion
,
6582 N_Unchecked_Type_Conversion
)
6583 or else (Is_Entity_Name
(Exp
)
6584 and then Ekind
(Entity
(Exp
)) in Formal_Kind
)
6585 or else Scope_Depth
(Enclosing_Dynamic_Scope
(Etype
(Exp
))) >
6586 Scope_Depth
(Enclosing_Dynamic_Scope
(Scope_Id
)))
6592 -- Ada 2005 (AI-251): In class-wide interface objects we displace
6593 -- "this" to reference the base of the object. This is required to
6594 -- get access to the TSD of the object.
6596 if Is_Class_Wide_Type
(Etype
(Exp
))
6597 and then Is_Interface
(Etype
(Exp
))
6599 -- If the expression is an explicit dereference then we can
6600 -- directly displace the pointer to reference the base of
6603 if Nkind
(Exp
) = N_Explicit_Dereference
then
6605 Make_Explicit_Dereference
(Loc
,
6607 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6608 Make_Function_Call
(Loc
,
6610 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6611 Parameter_Associations
=> New_List
(
6612 Unchecked_Convert_To
(RTE
(RE_Address
),
6613 Duplicate_Subexpr
(Prefix
(Exp
)))))));
6615 -- Similar case to the previous one but the expression is a
6616 -- renaming of an explicit dereference.
6618 elsif Nkind
(Exp
) = N_Identifier
6619 and then Present
(Renamed_Object
(Entity
(Exp
)))
6620 and then Nkind
(Renamed_Object
(Entity
(Exp
)))
6621 = N_Explicit_Dereference
6624 Make_Explicit_Dereference
(Loc
,
6626 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6627 Make_Function_Call
(Loc
,
6629 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6630 Parameter_Associations
=> New_List
(
6631 Unchecked_Convert_To
(RTE
(RE_Address
),
6634 (Renamed_Object
(Entity
(Exp
)))))))));
6636 -- Common case: obtain the address of the actual object and
6637 -- displace the pointer to reference the base of the object.
6641 Make_Explicit_Dereference
(Loc
,
6643 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6644 Make_Function_Call
(Loc
,
6646 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6647 Parameter_Associations
=> New_List
(
6648 Make_Attribute_Reference
(Loc
,
6649 Prefix
=> Duplicate_Subexpr
(Exp
),
6650 Attribute_Name
=> Name_Address
)))));
6654 Make_Attribute_Reference
(Loc
,
6655 Prefix
=> Duplicate_Subexpr
(Exp
),
6656 Attribute_Name
=> Name_Tag
);
6659 -- CodePeer does not do anything useful with
6660 -- Ada.Tags.Type_Specific_Data components.
6662 if not CodePeer_Mode
then
6664 Make_Raise_Program_Error
(Loc
,
6667 Left_Opnd
=> Build_Get_Access_Level
(Loc
, Tag_Node
),
6669 Make_Integer_Literal
(Loc
,
6670 Scope_Depth
(Enclosing_Dynamic_Scope
(Scope_Id
)))),
6671 Reason
=> PE_Accessibility_Check_Failed
));
6675 -- AI05-0073: If function has a controlling access result, check that
6676 -- the tag of the return value, if it is not null, matches designated
6677 -- type of return type.
6679 -- The return expression is referenced twice in the code below, so it
6680 -- must be made free of side effects. Given that different compilers
6681 -- may evaluate these parameters in different order, both occurrences
6684 elsif Ekind
(R_Type
) = E_Anonymous_Access_Type
6685 and then Has_Controlling_Result
(Scope_Id
)
6688 Make_Raise_Constraint_Error
(Loc
,
6693 Left_Opnd
=> Duplicate_Subexpr
(Exp
),
6694 Right_Opnd
=> Make_Null
(Loc
)),
6696 Right_Opnd
=> Make_Op_Ne
(Loc
,
6698 Make_Selected_Component
(Loc
,
6699 Prefix
=> Duplicate_Subexpr
(Exp
),
6700 Selector_Name
=> Make_Identifier
(Loc
, Name_uTag
)),
6703 Make_Attribute_Reference
(Loc
,
6705 New_Occurrence_Of
(Designated_Type
(R_Type
), Loc
),
6706 Attribute_Name
=> Name_Tag
))),
6708 Reason
=> CE_Tag_Check_Failed
),
6709 Suppress
=> All_Checks
);
6712 -- AI05-0234: RM 6.5(21/3). Check access discriminants to
6713 -- ensure that the function result does not outlive an
6714 -- object designated by one of it discriminants.
6716 if Present
(Extra_Accessibility_Of_Result
(Scope_Id
))
6717 and then Has_Unconstrained_Access_Discriminants
(R_Type
)
6720 Discrim_Source
: Node_Id
;
6722 procedure Check_Against_Result_Level
(Level
: Node_Id
);
6723 -- Check the given accessibility level against the level
6724 -- determined by the point of call. (AI05-0234).
6726 --------------------------------
6727 -- Check_Against_Result_Level --
6728 --------------------------------
6730 procedure Check_Against_Result_Level
(Level
: Node_Id
) is
6733 Make_Raise_Program_Error
(Loc
,
6739 (Extra_Accessibility_Of_Result
(Scope_Id
), Loc
)),
6740 Reason
=> PE_Accessibility_Check_Failed
));
6741 end Check_Against_Result_Level
;
6744 Discrim_Source
:= Exp
;
6745 while Nkind
(Discrim_Source
) = N_Qualified_Expression
loop
6746 Discrim_Source
:= Expression
(Discrim_Source
);
6749 if Nkind
(Discrim_Source
) = N_Identifier
6750 and then Is_Return_Object
(Entity
(Discrim_Source
))
6752 Discrim_Source
:= Entity
(Discrim_Source
);
6754 if Is_Constrained
(Etype
(Discrim_Source
)) then
6755 Discrim_Source
:= Etype
(Discrim_Source
);
6757 Discrim_Source
:= Expression
(Parent
(Discrim_Source
));
6760 elsif Nkind
(Discrim_Source
) = N_Identifier
6761 and then Nkind_In
(Original_Node
(Discrim_Source
),
6762 N_Aggregate
, N_Extension_Aggregate
)
6764 Discrim_Source
:= Original_Node
(Discrim_Source
);
6766 elsif Nkind
(Discrim_Source
) = N_Explicit_Dereference
and then
6767 Nkind
(Original_Node
(Discrim_Source
)) = N_Function_Call
6769 Discrim_Source
:= Original_Node
(Discrim_Source
);
6772 while Nkind_In
(Discrim_Source
, N_Qualified_Expression
,
6774 N_Unchecked_Type_Conversion
)
6776 Discrim_Source
:= Expression
(Discrim_Source
);
6779 case Nkind
(Discrim_Source
) is
6780 when N_Defining_Identifier
=>
6781 pragma Assert
(Is_Composite_Type
(Discrim_Source
)
6782 and then Has_Discriminants
(Discrim_Source
)
6783 and then Is_Constrained
(Discrim_Source
));
6786 Discrim
: Entity_Id
:=
6787 First_Discriminant
(Base_Type
(R_Type
));
6788 Disc_Elmt
: Elmt_Id
:=
6789 First_Elmt
(Discriminant_Constraint
6793 if Ekind
(Etype
(Discrim
)) =
6794 E_Anonymous_Access_Type
6796 Check_Against_Result_Level
6797 (Dynamic_Accessibility_Level
(Node
(Disc_Elmt
)));
6800 Next_Elmt
(Disc_Elmt
);
6801 Next_Discriminant
(Discrim
);
6802 exit when not Present
(Discrim
);
6807 | N_Extension_Aggregate
6809 -- Unimplemented: extension aggregate case where discrims
6810 -- come from ancestor part, not extension part.
6813 Discrim
: Entity_Id
:=
6814 First_Discriminant
(Base_Type
(R_Type
));
6816 Disc_Exp
: Node_Id
:= Empty
;
6818 Positionals_Exhausted
6819 : Boolean := not Present
(Expressions
6822 function Associated_Expr
6823 (Comp_Id
: Entity_Id
;
6824 Associations
: List_Id
) return Node_Id
;
6826 -- Given a component and a component associations list,
6827 -- locate the expression for that component; returns
6828 -- Empty if no such expression is found.
6830 ---------------------
6831 -- Associated_Expr --
6832 ---------------------
6834 function Associated_Expr
6835 (Comp_Id
: Entity_Id
;
6836 Associations
: List_Id
) return Node_Id
6842 -- Simple linear search seems ok here
6844 Assoc
:= First
(Associations
);
6845 while Present
(Assoc
) loop
6846 Choice
:= First
(Choices
(Assoc
));
6847 while Present
(Choice
) loop
6848 if (Nkind
(Choice
) = N_Identifier
6849 and then Chars
(Choice
) = Chars
(Comp_Id
))
6850 or else (Nkind
(Choice
) = N_Others_Choice
)
6852 return Expression
(Assoc
);
6862 end Associated_Expr
;
6864 -- Start of processing for Expand_Simple_Function_Return
6867 if not Positionals_Exhausted
then
6868 Disc_Exp
:= First
(Expressions
(Discrim_Source
));
6872 if Positionals_Exhausted
then
6876 Component_Associations
(Discrim_Source
));
6879 if Ekind
(Etype
(Discrim
)) =
6880 E_Anonymous_Access_Type
6882 Check_Against_Result_Level
6883 (Dynamic_Accessibility_Level
(Disc_Exp
));
6886 Next_Discriminant
(Discrim
);
6887 exit when not Present
(Discrim
);
6889 if not Positionals_Exhausted
then
6891 Positionals_Exhausted
:= not Present
(Disc_Exp
);
6896 when N_Function_Call
=>
6898 -- No check needed (check performed by callee)
6904 Level
: constant Node_Id
:=
6905 Make_Integer_Literal
(Loc
,
6906 Object_Access_Level
(Discrim_Source
));
6909 -- Unimplemented: check for name prefix that includes
6910 -- a dereference of an access value with a dynamic
6911 -- accessibility level (e.g., an access param or a
6912 -- saooaaat) and use dynamic level in that case. For
6914 -- return Access_Param.all(Some_Index).Some_Component;
6917 Set_Etype
(Level
, Standard_Natural
);
6918 Check_Against_Result_Level
(Level
);
6924 -- If we are returning an object that may not be bit-aligned, then copy
6925 -- the value into a temporary first. This copy may need to expand to a
6926 -- loop of component operations.
6928 if Is_Possibly_Unaligned_Slice
(Exp
)
6929 or else Is_Possibly_Unaligned_Object
(Exp
)
6932 ExpR
: constant Node_Id
:= Relocate_Node
(Exp
);
6933 Tnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T', ExpR
);
6936 Make_Object_Declaration
(Loc
,
6937 Defining_Identifier
=> Tnn
,
6938 Constant_Present
=> True,
6939 Object_Definition
=> New_Occurrence_Of
(R_Type
, Loc
),
6940 Expression
=> ExpR
),
6941 Suppress
=> All_Checks
);
6942 Rewrite
(Exp
, New_Occurrence_Of
(Tnn
, Loc
));
6946 -- Call the _Postconditions procedure if the related function has
6947 -- contract assertions that need to be verified on exit.
6949 if Ekind
(Scope_Id
) = E_Function
6950 and then Present
(Postconditions_Proc
(Scope_Id
))
6952 -- In the case of discriminated objects, we have created a
6953 -- constrained subtype above, and used the underlying type. This
6954 -- transformation is post-analysis and harmless, except that now the
6955 -- call to the post-condition will be analyzed and the type kinds
6958 if Nkind
(Exp
) = N_Unchecked_Type_Conversion
6959 and then Is_Private_Type
(R_Type
) /= Is_Private_Type
(Etype
(Exp
))
6961 Rewrite
(Exp
, Expression
(Relocate_Node
(Exp
)));
6964 -- We are going to reference the returned value twice in this case,
6965 -- once in the call to _Postconditions, and once in the actual return
6966 -- statement, but we can't have side effects happening twice.
6968 Force_Evaluation
(Exp
, Mode
=> Strict
);
6970 -- Generate call to _Postconditions
6973 Make_Procedure_Call_Statement
(Loc
,
6975 New_Occurrence_Of
(Postconditions_Proc
(Scope_Id
), Loc
),
6976 Parameter_Associations
=> New_List
(New_Copy_Tree
(Exp
))));
6979 -- Ada 2005 (AI-251): If this return statement corresponds with an
6980 -- simple return statement associated with an extended return statement
6981 -- and the type of the returned object is an interface then generate an
6982 -- implicit conversion to force displacement of the "this" pointer.
6984 if Ada_Version
>= Ada_2005
6985 and then Comes_From_Extended_Return_Statement
(N
)
6986 and then Nkind
(Expression
(N
)) = N_Identifier
6987 and then Is_Interface
(Utyp
)
6988 and then Utyp
/= Underlying_Type
(Exptyp
)
6990 Rewrite
(Exp
, Convert_To
(Utyp
, Relocate_Node
(Exp
)));
6991 Analyze_And_Resolve
(Exp
);
6993 end Expand_Simple_Function_Return
;
6995 --------------------------------------------
6996 -- Has_Unconstrained_Access_Discriminants --
6997 --------------------------------------------
6999 function Has_Unconstrained_Access_Discriminants
7000 (Subtyp
: Entity_Id
) return Boolean
7005 if Has_Discriminants
(Subtyp
)
7006 and then not Is_Constrained
(Subtyp
)
7008 Discr
:= First_Discriminant
(Subtyp
);
7009 while Present
(Discr
) loop
7010 if Ekind
(Etype
(Discr
)) = E_Anonymous_Access_Type
then
7014 Next_Discriminant
(Discr
);
7019 end Has_Unconstrained_Access_Discriminants
;
7021 --------------------------------
7022 -- Is_Build_In_Place_Function --
7023 --------------------------------
7025 function Is_Build_In_Place_Function
(E
: Entity_Id
) return Boolean is
7027 -- This function is called from Expand_Subtype_From_Expr during
7028 -- semantic analysis, even when expansion is off. In those cases
7029 -- the build_in_place expansion will not take place.
7031 if not Expander_Active
then
7035 -- For now we test whether E denotes a function or access-to-function
7036 -- type whose result subtype is inherently limited. Later this test
7037 -- may be revised to allow composite nonlimited types. Functions with
7038 -- a foreign convention or whose result type has a foreign convention
7041 if Ekind_In
(E
, E_Function
, E_Generic_Function
)
7042 or else (Ekind
(E
) = E_Subprogram_Type
7043 and then Etype
(E
) /= Standard_Void_Type
)
7045 -- Note: If the function has a foreign convention, it cannot build
7046 -- its result in place, so you're on your own. On the other hand,
7047 -- if only the return type has a foreign convention, its layout is
7048 -- intended to be compatible with the other language, but the build-
7049 -- in place machinery can ensure that the object is not copied.
7051 if Has_Foreign_Convention
(E
) then
7054 -- In Ada 2005 all functions with an inherently limited return type
7055 -- must be handled using a build-in-place profile, including the case
7056 -- of a function with a limited interface result, where the function
7057 -- may return objects of nonlimited descendants.
7060 return Is_Limited_View
(Etype
(E
))
7061 and then Ada_Version
>= Ada_2005
7062 and then not Debug_Flag_Dot_L
;
7068 end Is_Build_In_Place_Function
;
7070 -------------------------------------
7071 -- Is_Build_In_Place_Function_Call --
7072 -------------------------------------
7074 function Is_Build_In_Place_Function_Call
(N
: Node_Id
) return Boolean is
7075 Exp_Node
: Node_Id
:= N
;
7076 Function_Id
: Entity_Id
;
7079 -- Return False if the expander is currently inactive, since awareness
7080 -- of build-in-place treatment is only relevant during expansion. Note
7081 -- that Is_Build_In_Place_Function, which is called as part of this
7082 -- function, is also conditioned this way, but we need to check here as
7083 -- well to avoid blowing up on processing protected calls when expansion
7084 -- is disabled (such as with -gnatc) since those would trip over the
7085 -- raise of Program_Error below.
7087 -- In SPARK mode, build-in-place calls are not expanded, so that we
7088 -- may end up with a call that is neither resolved to an entity, nor
7089 -- an indirect call.
7091 if not Expander_Active
then
7095 -- Step past qualification, type conversion (which can occur in actual
7096 -- parameter contexts), and unchecked conversion (which can occur in
7097 -- cases of calls to 'Input).
7099 if Nkind_In
(Exp_Node
, N_Qualified_Expression
,
7101 N_Unchecked_Type_Conversion
)
7103 Exp_Node
:= Expression
(N
);
7106 if Nkind
(Exp_Node
) /= N_Function_Call
then
7110 if Is_Entity_Name
(Name
(Exp_Node
)) then
7111 Function_Id
:= Entity
(Name
(Exp_Node
));
7113 -- In the case of an explicitly dereferenced call, use the subprogram
7114 -- type generated for the dereference.
7116 elsif Nkind
(Name
(Exp_Node
)) = N_Explicit_Dereference
then
7117 Function_Id
:= Etype
(Name
(Exp_Node
));
7119 -- This may be a call to a protected function.
7121 elsif Nkind
(Name
(Exp_Node
)) = N_Selected_Component
then
7122 Function_Id
:= Etype
(Entity
(Selector_Name
(Name
(Exp_Node
))));
7125 raise Program_Error
;
7128 return Is_Build_In_Place_Function
(Function_Id
);
7130 end Is_Build_In_Place_Function_Call
;
7132 -----------------------
7133 -- Freeze_Subprogram --
7134 -----------------------
7136 procedure Freeze_Subprogram
(N
: Node_Id
) is
7137 Loc
: constant Source_Ptr
:= Sloc
(N
);
7139 procedure Register_Predefined_DT_Entry
(Prim
: Entity_Id
);
7140 -- (Ada 2005): Register a predefined primitive in all the secondary
7141 -- dispatch tables of its primitive type.
7143 ----------------------------------
7144 -- Register_Predefined_DT_Entry --
7145 ----------------------------------
7147 procedure Register_Predefined_DT_Entry
(Prim
: Entity_Id
) is
7148 Iface_DT_Ptr
: Elmt_Id
;
7149 Tagged_Typ
: Entity_Id
;
7150 Thunk_Id
: Entity_Id
;
7151 Thunk_Code
: Node_Id
;
7154 Tagged_Typ
:= Find_Dispatching_Type
(Prim
);
7156 if No
(Access_Disp_Table
(Tagged_Typ
))
7157 or else not Has_Interfaces
(Tagged_Typ
)
7158 or else not RTE_Available
(RE_Interface_Tag
)
7159 or else Restriction_Active
(No_Dispatching_Calls
)
7164 -- Skip the first two access-to-dispatch-table pointers since they
7165 -- leads to the primary dispatch table (predefined DT and user
7166 -- defined DT). We are only concerned with the secondary dispatch
7167 -- table pointers. Note that the access-to- dispatch-table pointer
7168 -- corresponds to the first implemented interface retrieved below.
7171 Next_Elmt
(Next_Elmt
(First_Elmt
(Access_Disp_Table
(Tagged_Typ
))));
7173 while Present
(Iface_DT_Ptr
)
7174 and then Ekind
(Node
(Iface_DT_Ptr
)) = E_Constant
7176 pragma Assert
(Has_Thunks
(Node
(Iface_DT_Ptr
)));
7177 Expand_Interface_Thunk
(Prim
, Thunk_Id
, Thunk_Code
);
7179 if Present
(Thunk_Code
) then
7180 Insert_Actions_After
(N
, New_List
(
7183 Build_Set_Predefined_Prim_Op_Address
(Loc
,
7185 New_Occurrence_Of
(Node
(Next_Elmt
(Iface_DT_Ptr
)), Loc
),
7186 Position
=> DT_Position
(Prim
),
7188 Unchecked_Convert_To
(RTE
(RE_Prim_Ptr
),
7189 Make_Attribute_Reference
(Loc
,
7190 Prefix
=> New_Occurrence_Of
(Thunk_Id
, Loc
),
7191 Attribute_Name
=> Name_Unrestricted_Access
))),
7193 Build_Set_Predefined_Prim_Op_Address
(Loc
,
7196 (Node
(Next_Elmt
(Next_Elmt
(Next_Elmt
(Iface_DT_Ptr
)))),
7198 Position
=> DT_Position
(Prim
),
7200 Unchecked_Convert_To
(RTE
(RE_Prim_Ptr
),
7201 Make_Attribute_Reference
(Loc
,
7202 Prefix
=> New_Occurrence_Of
(Prim
, Loc
),
7203 Attribute_Name
=> Name_Unrestricted_Access
)))));
7206 -- Skip the tag of the predefined primitives dispatch table
7208 Next_Elmt
(Iface_DT_Ptr
);
7209 pragma Assert
(Has_Thunks
(Node
(Iface_DT_Ptr
)));
7211 -- Skip tag of the no-thunks dispatch table
7213 Next_Elmt
(Iface_DT_Ptr
);
7214 pragma Assert
(not Has_Thunks
(Node
(Iface_DT_Ptr
)));
7216 -- Skip tag of predefined primitives no-thunks dispatch table
7218 Next_Elmt
(Iface_DT_Ptr
);
7219 pragma Assert
(not Has_Thunks
(Node
(Iface_DT_Ptr
)));
7221 Next_Elmt
(Iface_DT_Ptr
);
7223 end Register_Predefined_DT_Entry
;
7227 Subp
: constant Entity_Id
:= Entity
(N
);
7229 -- Start of processing for Freeze_Subprogram
7232 -- We suppress the initialization of the dispatch table entry when
7233 -- not Tagged_Type_Expansion because the dispatching mechanism is
7234 -- handled internally by the target.
7236 if Is_Dispatching_Operation
(Subp
)
7237 and then not Is_Abstract_Subprogram
(Subp
)
7238 and then Present
(DTC_Entity
(Subp
))
7239 and then Present
(Scope
(DTC_Entity
(Subp
)))
7240 and then Tagged_Type_Expansion
7241 and then not Restriction_Active
(No_Dispatching_Calls
)
7242 and then RTE_Available
(RE_Tag
)
7245 Typ
: constant Entity_Id
:= Scope
(DTC_Entity
(Subp
));
7248 -- Handle private overridden primitives
7250 if not Is_CPP_Class
(Typ
) then
7251 Check_Overriding_Operation
(Subp
);
7254 -- We assume that imported CPP primitives correspond with objects
7255 -- whose constructor is in the CPP side; therefore we don't need
7256 -- to generate code to register them in the dispatch table.
7258 if Is_CPP_Class
(Typ
) then
7261 -- Handle CPP primitives found in derivations of CPP_Class types.
7262 -- These primitives must have been inherited from some parent, and
7263 -- there is no need to register them in the dispatch table because
7264 -- Build_Inherit_Prims takes care of initializing these slots.
7266 elsif Is_Imported
(Subp
)
7267 and then (Convention
(Subp
) = Convention_CPP
7268 or else Convention
(Subp
) = Convention_C
)
7272 -- Generate code to register the primitive in non statically
7273 -- allocated dispatch tables
7275 elsif not Building_Static_DT
(Scope
(DTC_Entity
(Subp
))) then
7277 -- When a primitive is frozen, enter its name in its dispatch
7280 if not Is_Interface
(Typ
)
7281 or else Present
(Interface_Alias
(Subp
))
7283 if Is_Predefined_Dispatching_Operation
(Subp
) then
7284 Register_Predefined_DT_Entry
(Subp
);
7287 Insert_Actions_After
(N
,
7288 Register_Primitive
(Loc
, Prim
=> Subp
));
7294 -- Mark functions that return by reference. Note that it cannot be part
7295 -- of the normal semantic analysis of the spec since the underlying
7296 -- returned type may not be known yet (for private types).
7299 Typ
: constant Entity_Id
:= Etype
(Subp
);
7300 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
7303 if Is_Limited_View
(Typ
) then
7304 Set_Returns_By_Ref
(Subp
);
7306 elsif Present
(Utyp
) and then CW_Or_Has_Controlled_Part
(Utyp
) then
7307 Set_Returns_By_Ref
(Subp
);
7311 -- Wnen freezing a null procedure, analyze its delayed aspects now
7312 -- because we may not have reached the end of the declarative list when
7313 -- delayed aspects are normally analyzed. This ensures that dispatching
7314 -- calls are properly rewritten when the generated _Postcondition
7315 -- procedure is analyzed in the null procedure body.
7317 if Nkind
(Parent
(Subp
)) = N_Procedure_Specification
7318 and then Null_Present
(Parent
(Subp
))
7320 Analyze_Entry_Or_Subprogram_Contract
(Subp
);
7322 end Freeze_Subprogram
;
7324 ------------------------------
7325 -- Insert_Post_Call_Actions --
7326 ------------------------------
7328 procedure Insert_Post_Call_Actions
(N
: Node_Id
; Post_Call
: List_Id
) is
7329 Context
: constant Node_Id
:= Parent
(N
);
7332 if Is_Empty_List
(Post_Call
) then
7336 -- Cases where the call is not a member of a statement list. This
7337 -- includes the case where the call is an actual in another function
7338 -- call or indexing, i.e. an expression context as well.
7340 if not Is_List_Member
(N
)
7341 or else Nkind_In
(Context
, N_Function_Call
, N_Indexed_Component
)
7343 -- In Ada 2012 the call may be a function call in an expression
7344 -- (since OUT and IN OUT parameters are now allowed for such calls).
7345 -- The write-back of (in)-out parameters is handled by the back-end,
7346 -- but the constraint checks generated when subtypes of formal and
7347 -- actual don't match must be inserted in the form of assignments.
7349 if Nkind
(Original_Node
(N
)) = N_Function_Call
then
7350 pragma Assert
(Ada_Version
>= Ada_2012
);
7351 -- Functions with '[in] out' parameters are only allowed in Ada
7354 -- We used to handle this by climbing up parents to a
7355 -- non-statement/declaration and then simply making a call to
7356 -- Insert_Actions_After (P, Post_Call), but that doesn't work
7357 -- for Ada 2012. If we are in the middle of an expression, e.g.
7358 -- the condition of an IF, this call would insert after the IF
7359 -- statement, which is much too late to be doing the write back.
7362 -- if Clobber (X) then
7363 -- Put_Line (X'Img);
7368 -- Now assume Clobber changes X, if we put the write back after
7369 -- the IF, the Put_Line gets the wrong value and the goto causes
7370 -- the write back to be skipped completely.
7372 -- To deal with this, we replace the call by
7375 -- Tnnn : constant function-result-type := function-call;
7376 -- Post_Call actions
7382 Loc
: constant Source_Ptr
:= Sloc
(N
);
7383 Tnnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
7384 FRTyp
: constant Entity_Id
:= Etype
(N
);
7385 Name
: constant Node_Id
:= Relocate_Node
(N
);
7388 Prepend_To
(Post_Call
,
7389 Make_Object_Declaration
(Loc
,
7390 Defining_Identifier
=> Tnnn
,
7391 Object_Definition
=> New_Occurrence_Of
(FRTyp
, Loc
),
7392 Constant_Present
=> True,
7393 Expression
=> Name
));
7396 Make_Expression_With_Actions
(Loc
,
7397 Actions
=> Post_Call
,
7398 Expression
=> New_Occurrence_Of
(Tnnn
, Loc
)));
7400 -- We don't want to just blindly call Analyze_And_Resolve
7401 -- because that would cause unwanted recursion on the call.
7402 -- So for a moment set the call as analyzed to prevent that
7403 -- recursion, and get the rest analyzed properly, then reset
7404 -- the analyzed flag, so our caller can continue.
7406 Set_Analyzed
(Name
, True);
7407 Analyze_And_Resolve
(N
, FRTyp
);
7408 Set_Analyzed
(Name
, False);
7411 -- If not the special Ada 2012 case of a function call, then we must
7412 -- have the triggering statement of a triggering alternative or an
7413 -- entry call alternative, and we can add the post call stuff to the
7414 -- corresponding statement list.
7417 pragma Assert
(Nkind_In
(Context
, N_Entry_Call_Alternative
,
7418 N_Triggering_Alternative
));
7420 if Is_Non_Empty_List
(Statements
(Context
)) then
7421 Insert_List_Before_And_Analyze
7422 (First
(Statements
(Context
)), Post_Call
);
7424 Set_Statements
(Context
, Post_Call
);
7428 -- A procedure call is always part of a declarative or statement list,
7429 -- however a function call may appear nested within a construct. Most
7430 -- cases of function call nesting are handled in the special case above.
7431 -- The only exception is when the function call acts as an actual in a
7432 -- procedure call. In this case the function call is in a list, but the
7433 -- post-call actions must be inserted after the procedure call.
7435 elsif Nkind
(Context
) = N_Procedure_Call_Statement
then
7436 Insert_Actions_After
(Context
, Post_Call
);
7438 -- Otherwise, normal case where N is in a statement sequence, just put
7439 -- the post-call stuff after the call statement.
7442 Insert_Actions_After
(N
, Post_Call
);
7444 end Insert_Post_Call_Actions
;
7446 -----------------------
7447 -- Is_Null_Procedure --
7448 -----------------------
7450 function Is_Null_Procedure
(Subp
: Entity_Id
) return Boolean is
7451 Decl
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
7454 if Ekind
(Subp
) /= E_Procedure
then
7457 -- Check if this is a declared null procedure
7459 elsif Nkind
(Decl
) = N_Subprogram_Declaration
then
7460 if not Null_Present
(Specification
(Decl
)) then
7463 elsif No
(Body_To_Inline
(Decl
)) then
7466 -- Check if the body contains only a null statement, followed by
7467 -- the return statement added during expansion.
7471 Orig_Bod
: constant Node_Id
:= Body_To_Inline
(Decl
);
7477 if Nkind
(Orig_Bod
) /= N_Subprogram_Body
then
7480 -- We must skip SCIL nodes because they are currently
7481 -- implemented as special N_Null_Statement nodes.
7485 (Statements
(Handled_Statement_Sequence
(Orig_Bod
)));
7486 Stat2
:= Next_Non_SCIL_Node
(Stat
);
7489 Is_Empty_List
(Declarations
(Orig_Bod
))
7490 and then Nkind
(Stat
) = N_Null_Statement
7494 (Nkind
(Stat2
) = N_Simple_Return_Statement
7495 and then No
(Next
(Stat2
))));
7503 end Is_Null_Procedure
;
7505 -------------------------------------------
7506 -- Make_Build_In_Place_Call_In_Allocator --
7507 -------------------------------------------
7509 procedure Make_Build_In_Place_Call_In_Allocator
7510 (Allocator
: Node_Id
;
7511 Function_Call
: Node_Id
)
7513 Acc_Type
: constant Entity_Id
:= Etype
(Allocator
);
7515 Func_Call
: Node_Id
:= Function_Call
;
7516 Ref_Func_Call
: Node_Id
;
7517 Function_Id
: Entity_Id
;
7518 Result_Subt
: Entity_Id
;
7519 New_Allocator
: Node_Id
;
7520 Return_Obj_Access
: Entity_Id
; -- temp for function result
7521 Temp_Init
: Node_Id
; -- initial value of Return_Obj_Access
7522 Alloc_Form
: BIP_Allocation_Form
;
7523 Pool
: Node_Id
; -- nonnull if Alloc_Form = User_Storage_Pool
7524 Return_Obj_Actual
: Node_Id
; -- the temp.all, in caller-allocates case
7525 Chain
: Entity_Id
; -- activation chain, in case of tasks
7528 -- Step past qualification or unchecked conversion (the latter can occur
7529 -- in cases of calls to 'Input).
7531 if Nkind_In
(Func_Call
,
7532 N_Qualified_Expression
,
7534 N_Unchecked_Type_Conversion
)
7536 Func_Call
:= Expression
(Func_Call
);
7539 -- If the call has already been processed to add build-in-place actuals
7540 -- then return. This should not normally occur in an allocator context,
7541 -- but we add the protection as a defensive measure.
7543 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
7547 -- Mark the call as processed as a build-in-place call
7549 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
7551 Loc
:= Sloc
(Function_Call
);
7553 if Is_Entity_Name
(Name
(Func_Call
)) then
7554 Function_Id
:= Entity
(Name
(Func_Call
));
7556 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
7557 Function_Id
:= Etype
(Name
(Func_Call
));
7560 raise Program_Error
;
7563 Result_Subt
:= Available_View
(Etype
(Function_Id
));
7565 -- Create a temp for the function result. In the caller-allocates case,
7566 -- this will be initialized to the result of a new uninitialized
7567 -- allocator. Note: we do not use Allocator as the Related_Node of
7568 -- Return_Obj_Access in call to Make_Temporary below as this would
7569 -- create a sort of infinite "recursion".
7571 Return_Obj_Access
:= Make_Temporary
(Loc
, 'R');
7572 Set_Etype
(Return_Obj_Access
, Acc_Type
);
7574 -- When the result subtype is constrained, the return object is
7575 -- allocated on the caller side, and access to it is passed to the
7578 -- Here and in related routines, we must examine the full view of the
7579 -- type, because the view at the point of call may differ from that
7580 -- that in the function body, and the expansion mechanism depends on
7581 -- the characteristics of the full view.
7583 if Is_Constrained
(Underlying_Type
(Result_Subt
)) then
7585 -- Replace the initialized allocator of form "new T'(Func (...))"
7586 -- with an uninitialized allocator of form "new T", where T is the
7587 -- result subtype of the called function. The call to the function
7588 -- is handled separately further below.
7591 Make_Allocator
(Loc
,
7592 Expression
=> New_Occurrence_Of
(Result_Subt
, Loc
));
7593 Set_No_Initialization
(New_Allocator
);
7595 -- Copy attributes to new allocator. Note that the new allocator
7596 -- logically comes from source if the original one did, so copy the
7597 -- relevant flag. This ensures proper treatment of the restriction
7598 -- No_Implicit_Heap_Allocations in this case.
7600 Set_Storage_Pool
(New_Allocator
, Storage_Pool
(Allocator
));
7601 Set_Procedure_To_Call
(New_Allocator
, Procedure_To_Call
(Allocator
));
7602 Set_Comes_From_Source
(New_Allocator
, Comes_From_Source
(Allocator
));
7604 Rewrite
(Allocator
, New_Allocator
);
7606 -- Initial value of the temp is the result of the uninitialized
7609 Temp_Init
:= Relocate_Node
(Allocator
);
7611 -- Indicate that caller allocates, and pass in the return object
7613 Alloc_Form
:= Caller_Allocation
;
7614 Pool
:= Make_Null
(No_Location
);
7615 Return_Obj_Actual
:=
7616 Make_Unchecked_Type_Conversion
(Loc
,
7617 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
7619 Make_Explicit_Dereference
(Loc
,
7620 Prefix
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
)));
7622 -- When the result subtype is unconstrained, the function itself must
7623 -- perform the allocation of the return object, so we pass parameters
7629 -- Case of a user-defined storage pool. Pass an allocation parameter
7630 -- indicating that the function should allocate its result in the
7631 -- pool, and pass the pool. Use 'Unrestricted_Access because the
7632 -- pool may not be aliased.
7634 if Present
(Associated_Storage_Pool
(Acc_Type
)) then
7635 Alloc_Form
:= User_Storage_Pool
;
7637 Make_Attribute_Reference
(Loc
,
7640 (Associated_Storage_Pool
(Acc_Type
), Loc
),
7641 Attribute_Name
=> Name_Unrestricted_Access
);
7643 -- No user-defined pool; pass an allocation parameter indicating that
7644 -- the function should allocate its result on the heap.
7647 Alloc_Form
:= Global_Heap
;
7648 Pool
:= Make_Null
(No_Location
);
7651 -- The caller does not provide the return object in this case, so we
7652 -- have to pass null for the object access actual.
7654 Return_Obj_Actual
:= Empty
;
7657 -- Declare the temp object
7659 Insert_Action
(Allocator
,
7660 Make_Object_Declaration
(Loc
,
7661 Defining_Identifier
=> Return_Obj_Access
,
7662 Object_Definition
=> New_Occurrence_Of
(Acc_Type
, Loc
),
7663 Expression
=> Temp_Init
));
7665 Ref_Func_Call
:= Make_Reference
(Loc
, Func_Call
);
7667 -- Ada 2005 (AI-251): If the type of the allocator is an interface
7668 -- then generate an implicit conversion to force displacement of the
7671 if Is_Interface
(Designated_Type
(Acc_Type
)) then
7674 OK_Convert_To
(Acc_Type
, Ref_Func_Call
));
7678 Assign
: constant Node_Id
:=
7679 Make_Assignment_Statement
(Loc
,
7680 Name
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
),
7681 Expression
=> Ref_Func_Call
);
7682 -- Assign the result of the function call into the temp. In the
7683 -- caller-allocates case, this is overwriting the temp with its
7684 -- initial value, which has no effect. In the callee-allocates case,
7685 -- this is setting the temp to point to the object allocated by the
7689 -- Actions to be inserted. If there are no tasks, this is just the
7690 -- assignment statement. If the allocated object has tasks, we need
7691 -- to wrap the assignment in a block that activates them. The
7692 -- activation chain of that block must be passed to the function,
7693 -- rather than some outer chain.
7695 if Has_Task
(Result_Subt
) then
7696 Actions
:= New_List
;
7697 Build_Task_Allocate_Block_With_Init_Stmts
7698 (Actions
, Allocator
, Init_Stmts
=> New_List
(Assign
));
7699 Chain
:= Activation_Chain_Entity
(Last
(Actions
));
7701 Actions
:= New_List
(Assign
);
7705 Insert_Actions
(Allocator
, Actions
);
7708 -- When the function has a controlling result, an allocation-form
7709 -- parameter must be passed indicating that the caller is allocating
7710 -- the result object. This is needed because such a function can be
7711 -- called as a dispatching operation and must be treated similarly
7712 -- to functions with unconstrained result subtypes.
7714 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7715 (Func_Call
, Function_Id
, Alloc_Form
, Pool_Actual
=> Pool
);
7717 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7718 (Func_Call
, Function_Id
, Acc_Type
);
7720 Add_Task_Actuals_To_Build_In_Place_Call
7721 (Func_Call
, Function_Id
, Master_Actual
=> Master_Id
(Acc_Type
),
7724 -- Add an implicit actual to the function call that provides access
7725 -- to the allocated object. An unchecked conversion to the (specific)
7726 -- result subtype of the function is inserted to handle cases where
7727 -- the access type of the allocator has a class-wide designated type.
7729 Add_Access_Actual_To_Build_In_Place_Call
7730 (Func_Call
, Function_Id
, Return_Obj_Actual
);
7732 -- Finally, replace the allocator node with a reference to the temp
7734 Rewrite
(Allocator
, New_Occurrence_Of
(Return_Obj_Access
, Loc
));
7736 Analyze_And_Resolve
(Allocator
, Acc_Type
);
7737 end Make_Build_In_Place_Call_In_Allocator
;
7739 ---------------------------------------------------
7740 -- Make_Build_In_Place_Call_In_Anonymous_Context --
7741 ---------------------------------------------------
7743 procedure Make_Build_In_Place_Call_In_Anonymous_Context
7744 (Function_Call
: Node_Id
)
7747 Func_Call
: Node_Id
:= Function_Call
;
7748 Function_Id
: Entity_Id
;
7749 Result_Subt
: Entity_Id
;
7750 Return_Obj_Id
: Entity_Id
;
7751 Return_Obj_Decl
: Entity_Id
;
7754 -- True if result subtype is definite, or has a size that does not
7755 -- require secondary stack usage (i.e. no variant part or components
7756 -- whose type depends on discriminants). In particular, untagged types
7757 -- with only access discriminants do not require secondary stack use.
7758 -- Note that if the return type is tagged we must always use the sec.
7759 -- stack because the call may dispatch on result.
7762 -- Step past qualification, type conversion (which can occur in actual
7763 -- parameter contexts), and unchecked conversion (which can occur in
7764 -- cases of calls to 'Input).
7766 if Nkind_In
(Func_Call
, N_Qualified_Expression
,
7768 N_Unchecked_Type_Conversion
)
7770 Func_Call
:= Expression
(Func_Call
);
7773 -- If the call has already been processed to add build-in-place actuals
7774 -- then return. One place this can occur is for calls to build-in-place
7775 -- functions that occur within a call to a protected operation, where
7776 -- due to rewriting and expansion of the protected call there can be
7777 -- more than one call to Expand_Actuals for the same set of actuals.
7779 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
7783 -- Mark the call as processed as a build-in-place call
7785 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
7787 Loc
:= Sloc
(Function_Call
);
7789 if Is_Entity_Name
(Name
(Func_Call
)) then
7790 Function_Id
:= Entity
(Name
(Func_Call
));
7792 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
7793 Function_Id
:= Etype
(Name
(Func_Call
));
7796 raise Program_Error
;
7799 Result_Subt
:= Etype
(Function_Id
);
7801 (Is_Definite_Subtype
(Underlying_Type
(Result_Subt
))
7802 and then not Is_Tagged_Type
(Result_Subt
))
7803 or else not Requires_Transient_Scope
(Underlying_Type
(Result_Subt
));
7805 -- If the build-in-place function returns a controlled object, then the
7806 -- object needs to be finalized immediately after the context. Since
7807 -- this case produces a transient scope, the servicing finalizer needs
7808 -- to name the returned object. Create a temporary which is initialized
7809 -- with the function call:
7811 -- Temp_Id : Func_Type := BIP_Func_Call;
7813 -- The initialization expression of the temporary will be rewritten by
7814 -- the expander using the appropriate mechanism in Make_Build_In_Place_
7815 -- Call_In_Object_Declaration.
7817 if Needs_Finalization
(Result_Subt
) then
7819 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'R');
7820 Temp_Decl
: Node_Id
;
7823 -- Reset the guard on the function call since the following does
7824 -- not perform actual call expansion.
7826 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
, False);
7829 Make_Object_Declaration
(Loc
,
7830 Defining_Identifier
=> Temp_Id
,
7831 Object_Definition
=>
7832 New_Occurrence_Of
(Result_Subt
, Loc
),
7834 New_Copy_Tree
(Function_Call
));
7836 Insert_Action
(Function_Call
, Temp_Decl
);
7838 Rewrite
(Function_Call
, New_Occurrence_Of
(Temp_Id
, Loc
));
7839 Analyze
(Function_Call
);
7842 -- When the result subtype is definite, an object of the subtype is
7843 -- declared and an access value designating it is passed as an actual.
7847 -- Create a temporary object to hold the function result
7849 Return_Obj_Id
:= Make_Temporary
(Loc
, 'R');
7850 Set_Etype
(Return_Obj_Id
, Result_Subt
);
7853 Make_Object_Declaration
(Loc
,
7854 Defining_Identifier
=> Return_Obj_Id
,
7855 Aliased_Present
=> True,
7856 Object_Definition
=> New_Occurrence_Of
(Result_Subt
, Loc
));
7858 Set_No_Initialization
(Return_Obj_Decl
);
7860 Insert_Action
(Func_Call
, Return_Obj_Decl
);
7862 -- When the function has a controlling result, an allocation-form
7863 -- parameter must be passed indicating that the caller is allocating
7864 -- the result object. This is needed because such a function can be
7865 -- called as a dispatching operation and must be treated similarly
7866 -- to functions with unconstrained result subtypes.
7868 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7869 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
7871 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7872 (Func_Call
, Function_Id
);
7874 Add_Task_Actuals_To_Build_In_Place_Call
7875 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
7877 -- Add an implicit actual to the function call that provides access
7878 -- to the caller's return object.
7880 Add_Access_Actual_To_Build_In_Place_Call
7881 (Func_Call
, Function_Id
, New_Occurrence_Of
(Return_Obj_Id
, Loc
));
7883 -- When the result subtype is unconstrained, the function must allocate
7884 -- the return object in the secondary stack, so appropriate implicit
7885 -- parameters are added to the call to indicate that. A transient
7886 -- scope is established to ensure eventual cleanup of the result.
7889 -- Pass an allocation parameter indicating that the function should
7890 -- allocate its result on the secondary stack.
7892 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7893 (Func_Call
, Function_Id
, Alloc_Form
=> Secondary_Stack
);
7895 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7896 (Func_Call
, Function_Id
);
7898 Add_Task_Actuals_To_Build_In_Place_Call
7899 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
7901 -- Pass a null value to the function since no return object is
7902 -- available on the caller side.
7904 Add_Access_Actual_To_Build_In_Place_Call
7905 (Func_Call
, Function_Id
, Empty
);
7907 end Make_Build_In_Place_Call_In_Anonymous_Context
;
7909 --------------------------------------------
7910 -- Make_Build_In_Place_Call_In_Assignment --
7911 --------------------------------------------
7913 procedure Make_Build_In_Place_Call_In_Assignment
7915 Function_Call
: Node_Id
)
7917 Lhs
: constant Node_Id
:= Name
(Assign
);
7918 Func_Call
: Node_Id
:= Function_Call
;
7919 Func_Id
: Entity_Id
;
7923 Ptr_Typ
: Entity_Id
;
7924 Ptr_Typ_Decl
: Node_Id
;
7926 Result_Subt
: Entity_Id
;
7930 -- Step past qualification or unchecked conversion (the latter can occur
7931 -- in cases of calls to 'Input).
7933 if Nkind_In
(Func_Call
, N_Qualified_Expression
,
7934 N_Unchecked_Type_Conversion
)
7936 Func_Call
:= Expression
(Func_Call
);
7939 -- If the call has already been processed to add build-in-place actuals
7940 -- then return. This should not normally occur in an assignment context,
7941 -- but we add the protection as a defensive measure.
7943 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
7947 -- Mark the call as processed as a build-in-place call
7949 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
7951 Loc
:= Sloc
(Function_Call
);
7953 if Is_Entity_Name
(Name
(Func_Call
)) then
7954 Func_Id
:= Entity
(Name
(Func_Call
));
7956 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
7957 Func_Id
:= Etype
(Name
(Func_Call
));
7960 raise Program_Error
;
7963 Result_Subt
:= Etype
(Func_Id
);
7965 -- When the result subtype is unconstrained, an additional actual must
7966 -- be passed to indicate that the caller is providing the return object.
7967 -- This parameter must also be passed when the called function has a
7968 -- controlling result, because dispatching calls to the function needs
7969 -- to be treated effectively the same as calls to class-wide functions.
7971 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7972 (Func_Call
, Func_Id
, Alloc_Form
=> Caller_Allocation
);
7974 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7975 (Func_Call
, Func_Id
);
7977 Add_Task_Actuals_To_Build_In_Place_Call
7978 (Func_Call
, Func_Id
, Make_Identifier
(Loc
, Name_uMaster
));
7980 -- Add an implicit actual to the function call that provides access to
7981 -- the caller's return object.
7983 Add_Access_Actual_To_Build_In_Place_Call
7986 Make_Unchecked_Type_Conversion
(Loc
,
7987 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
7988 Expression
=> Relocate_Node
(Lhs
)));
7990 -- Create an access type designating the function's result subtype
7992 Ptr_Typ
:= Make_Temporary
(Loc
, 'A');
7995 Make_Full_Type_Declaration
(Loc
,
7996 Defining_Identifier
=> Ptr_Typ
,
7998 Make_Access_To_Object_Definition
(Loc
,
7999 All_Present
=> True,
8000 Subtype_Indication
=>
8001 New_Occurrence_Of
(Result_Subt
, Loc
)));
8002 Insert_After_And_Analyze
(Assign
, Ptr_Typ_Decl
);
8004 -- Finally, create an access object initialized to a reference to the
8005 -- function call. We know this access value is non-null, so mark the
8006 -- entity accordingly to suppress junk access checks.
8008 New_Expr
:= Make_Reference
(Loc
, Relocate_Node
(Func_Call
));
8010 Obj_Id
:= Make_Temporary
(Loc
, 'R', New_Expr
);
8011 Set_Etype
(Obj_Id
, Ptr_Typ
);
8012 Set_Is_Known_Non_Null
(Obj_Id
);
8015 Make_Object_Declaration
(Loc
,
8016 Defining_Identifier
=> Obj_Id
,
8017 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8018 Expression
=> New_Expr
);
8019 Insert_After_And_Analyze
(Ptr_Typ_Decl
, Obj_Decl
);
8021 Rewrite
(Assign
, Make_Null_Statement
(Loc
));
8023 -- Retrieve the target of the assignment
8025 if Nkind
(Lhs
) = N_Selected_Component
then
8026 Target
:= Selector_Name
(Lhs
);
8027 elsif Nkind
(Lhs
) = N_Type_Conversion
then
8028 Target
:= Expression
(Lhs
);
8033 -- If we are assigning to a return object or this is an expression of
8034 -- an extension aggregate, the target should either be an identifier
8035 -- or a simple expression. All other cases imply a different scenario.
8037 if Nkind
(Target
) in N_Has_Entity
then
8038 Target
:= Entity
(Target
);
8042 end Make_Build_In_Place_Call_In_Assignment
;
8044 ----------------------------------------------------
8045 -- Make_Build_In_Place_Call_In_Object_Declaration --
8046 ----------------------------------------------------
8048 procedure Make_Build_In_Place_Call_In_Object_Declaration
8049 (Obj_Decl
: Node_Id
;
8050 Function_Call
: Node_Id
)
8052 Obj_Def_Id
: constant Entity_Id
:= Defining_Identifier
(Obj_Decl
);
8053 Encl_Func
: constant Entity_Id
:= Enclosing_Subprogram
(Obj_Def_Id
);
8054 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8055 Obj_Loc
: constant Source_Ptr
:= Sloc
(Obj_Decl
);
8057 Call_Deref
: Node_Id
;
8058 Caller_Object
: Node_Id
;
8060 Fmaster_Actual
: Node_Id
:= Empty
;
8061 Func_Call
: Node_Id
:= Function_Call
;
8062 Function_Id
: Entity_Id
;
8063 Pool_Actual
: Node_Id
;
8064 Ptr_Typ
: Entity_Id
;
8065 Ptr_Typ_Decl
: Node_Id
;
8066 Pass_Caller_Acc
: Boolean := False;
8068 Result_Subt
: Entity_Id
;
8071 -- True if result subtype is definite, or has a size that does not
8072 -- require secondary stack usage (i.e. no variant part or components
8073 -- whose type depends on discriminants). In particular, untagged types
8074 -- with only access discriminants do not require secondary stack use.
8075 -- Note that if the return type is tagged we must always use the sec.
8076 -- stack because the call may dispatch on result.
8079 -- Step past qualification or unchecked conversion (the latter can occur
8080 -- in cases of calls to 'Input).
8082 if Nkind_In
(Func_Call
, N_Qualified_Expression
,
8083 N_Unchecked_Type_Conversion
)
8085 Func_Call
:= Expression
(Func_Call
);
8088 -- If the call has already been processed to add build-in-place actuals
8089 -- then return. This should not normally occur in an object declaration,
8090 -- but we add the protection as a defensive measure.
8092 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
8096 -- Mark the call as processed as a build-in-place call
8098 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
8100 if Is_Entity_Name
(Name
(Func_Call
)) then
8101 Function_Id
:= Entity
(Name
(Func_Call
));
8103 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
8104 Function_Id
:= Etype
(Name
(Func_Call
));
8107 raise Program_Error
;
8110 Result_Subt
:= Etype
(Function_Id
);
8112 (Is_Definite_Subtype
(Underlying_Type
(Result_Subt
))
8113 and then not Is_Tagged_Type
(Result_Subt
))
8114 or else not Requires_Transient_Scope
(Underlying_Type
(Result_Subt
));
8116 -- Create an access type designating the function's result subtype. We
8117 -- use the type of the original call because it may be a call to an
8118 -- inherited operation, which the expansion has replaced with the parent
8119 -- operation that yields the parent type. Note that this access type
8120 -- must be declared before we establish a transient scope, so that it
8121 -- receives the proper accessibility level.
8123 Ptr_Typ
:= Make_Temporary
(Loc
, 'A');
8125 Make_Full_Type_Declaration
(Loc
,
8126 Defining_Identifier
=> Ptr_Typ
,
8128 Make_Access_To_Object_Definition
(Loc
,
8129 All_Present
=> True,
8130 Subtype_Indication
=>
8131 New_Occurrence_Of
(Etype
(Function_Call
), Loc
)));
8133 -- The access type and its accompanying object must be inserted after
8134 -- the object declaration in the constrained case, so that the function
8135 -- call can be passed access to the object. In the indefinite case,
8136 -- or if the object declaration is for a return object, the access type
8137 -- and object must be inserted before the object, since the object
8138 -- declaration is rewritten to be a renaming of a dereference of the
8139 -- access object. Note: we need to freeze Ptr_Typ explicitly, because
8140 -- the result object is in a different (transient) scope, so won't
8144 and then not Is_Return_Object
(Defining_Identifier
(Obj_Decl
))
8146 Insert_After_And_Analyze
(Obj_Decl
, Ptr_Typ_Decl
);
8148 Insert_Action
(Obj_Decl
, Ptr_Typ_Decl
);
8151 -- Force immediate freezing of Ptr_Typ because Res_Decl will be
8152 -- elaborated in an inner (transient) scope and thus won't cause
8153 -- freezing by itself.
8156 Ptr_Typ_Freeze_Ref
: constant Node_Id
:=
8157 New_Occurrence_Of
(Ptr_Typ
, Loc
);
8159 Set_Parent
(Ptr_Typ_Freeze_Ref
, Ptr_Typ_Decl
);
8160 Freeze_Expression
(Ptr_Typ_Freeze_Ref
);
8163 -- If the object is a return object of an enclosing build-in-place
8164 -- function, then the implicit build-in-place parameters of the
8165 -- enclosing function are simply passed along to the called function.
8166 -- (Unfortunately, this won't cover the case of extension aggregates
8167 -- where the ancestor part is a build-in-place indefinite function
8168 -- call that should be passed along the caller's parameters. Currently
8169 -- those get mishandled by reassigning the result of the call to the
8170 -- aggregate return object, when the call result should really be
8171 -- directly built in place in the aggregate and not in a temporary. ???)
8173 if Is_Return_Object
(Defining_Identifier
(Obj_Decl
)) then
8174 Pass_Caller_Acc
:= True;
8176 -- When the enclosing function has a BIP_Alloc_Form formal then we
8177 -- pass it along to the callee (such as when the enclosing function
8178 -- has an unconstrained or tagged result type).
8180 if Needs_BIP_Alloc_Form
(Encl_Func
) then
8181 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
8184 (Build_In_Place_Formal
(Encl_Func
, BIP_Storage_Pool
), Loc
);
8186 -- The build-in-place pool formal is not built on e.g. ZFP
8189 Pool_Actual
:= Empty
;
8192 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8193 (Function_Call
=> Func_Call
,
8194 Function_Id
=> Function_Id
,
8197 (Build_In_Place_Formal
(Encl_Func
, BIP_Alloc_Form
), Loc
),
8198 Pool_Actual
=> Pool_Actual
);
8200 -- Otherwise, if enclosing function has a definite result subtype,
8201 -- then caller allocation will be used.
8204 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8205 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8208 if Needs_BIP_Finalization_Master
(Encl_Func
) then
8211 (Build_In_Place_Formal
8212 (Encl_Func
, BIP_Finalization_Master
), Loc
);
8215 -- Retrieve the BIPacc formal from the enclosing function and convert
8216 -- it to the access type of the callee's BIP_Object_Access formal.
8219 Make_Unchecked_Type_Conversion
(Loc
,
8223 (Build_In_Place_Formal
(Function_Id
, BIP_Object_Access
)),
8227 (Build_In_Place_Formal
(Encl_Func
, BIP_Object_Access
),
8230 -- In the definite case, add an implicit actual to the function call
8231 -- that provides access to the declared object. An unchecked conversion
8232 -- to the (specific) result type of the function is inserted to handle
8233 -- the case where the object is declared with a class-wide type.
8237 Make_Unchecked_Type_Conversion
(Loc
,
8238 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
8239 Expression
=> New_Occurrence_Of
(Obj_Def_Id
, Loc
));
8241 -- When the function has a controlling result, an allocation-form
8242 -- parameter must be passed indicating that the caller is allocating
8243 -- the result object. This is needed because such a function can be
8244 -- called as a dispatching operation and must be treated similarly
8245 -- to functions with indefinite result subtypes.
8247 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8248 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8250 -- The allocation for indefinite library-level objects occurs on the
8251 -- heap as opposed to the secondary stack. This accommodates DLLs where
8252 -- the secondary stack is destroyed after each library unload. This is
8253 -- a hybrid mechanism where a stack-allocated object lives on the heap.
8255 elsif Is_Library_Level_Entity
(Defining_Identifier
(Obj_Decl
))
8256 and then not Restriction_Active
(No_Implicit_Heap_Allocations
)
8258 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8259 (Func_Call
, Function_Id
, Alloc_Form
=> Global_Heap
);
8260 Caller_Object
:= Empty
;
8262 -- Create a finalization master for the access result type to ensure
8263 -- that the heap allocation can properly chain the object and later
8264 -- finalize it when the library unit goes out of scope.
8266 if Needs_Finalization
(Etype
(Func_Call
)) then
8267 Build_Finalization_Master
8269 For_Lib_Level
=> True,
8270 Insertion_Node
=> Ptr_Typ_Decl
);
8273 Make_Attribute_Reference
(Loc
,
8275 New_Occurrence_Of
(Finalization_Master
(Ptr_Typ
), Loc
),
8276 Attribute_Name
=> Name_Unrestricted_Access
);
8279 -- In other indefinite cases, pass an indication to do the allocation
8280 -- on the secondary stack and set Caller_Object to Empty so that a null
8281 -- value will be passed for the caller's object address. A transient
8282 -- scope is established to ensure eventual cleanup of the result.
8285 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8286 (Func_Call
, Function_Id
, Alloc_Form
=> Secondary_Stack
);
8287 Caller_Object
:= Empty
;
8289 Establish_Transient_Scope
(Obj_Decl
, Sec_Stack
=> True);
8292 -- Pass along any finalization master actual, which is needed in the
8293 -- case where the called function initializes a return object of an
8294 -- enclosing build-in-place function.
8296 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8297 (Func_Call
=> Func_Call
,
8298 Func_Id
=> Function_Id
,
8299 Master_Exp
=> Fmaster_Actual
);
8301 if Nkind
(Parent
(Obj_Decl
)) = N_Extended_Return_Statement
8302 and then Has_Task
(Result_Subt
)
8304 -- Here we're passing along the master that was passed in to this
8307 Add_Task_Actuals_To_Build_In_Place_Call
8308 (Func_Call
, Function_Id
,
8311 (Build_In_Place_Formal
(Encl_Func
, BIP_Task_Master
), Loc
));
8314 Add_Task_Actuals_To_Build_In_Place_Call
8315 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8318 Add_Access_Actual_To_Build_In_Place_Call
8319 (Func_Call
, Function_Id
, Caller_Object
, Is_Access
=> Pass_Caller_Acc
);
8321 -- Finally, create an access object initialized to a reference to the
8322 -- function call. We know this access value cannot be null, so mark the
8323 -- entity accordingly to suppress the access check.
8325 Def_Id
:= Make_Temporary
(Loc
, 'R', Func_Call
);
8326 Set_Etype
(Def_Id
, Ptr_Typ
);
8327 Set_Is_Known_Non_Null
(Def_Id
);
8330 Make_Object_Declaration
(Loc
,
8331 Defining_Identifier
=> Def_Id
,
8332 Constant_Present
=> True,
8333 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8335 Make_Reference
(Loc
, Relocate_Node
(Func_Call
)));
8337 Insert_After_And_Analyze
(Ptr_Typ_Decl
, Res_Decl
);
8339 -- If the result subtype of the called function is definite and is not
8340 -- itself the return expression of an enclosing BIP function, then mark
8341 -- the object as having no initialization.
8344 and then not Is_Return_Object
(Defining_Identifier
(Obj_Decl
))
8346 -- The related object declaration is encased in a transient block
8347 -- because the build-in-place function call contains at least one
8348 -- nested function call that produces a controlled transient
8351 -- Obj : ... := BIP_Func_Call (Ctrl_Func_Call);
8353 -- Since the build-in-place expansion decouples the call from the
8354 -- object declaration, the finalization machinery lacks the context
8355 -- which prompted the generation of the transient block. To resolve
8356 -- this scenario, store the build-in-place call.
8358 if Scope_Is_Transient
and then Node_To_Be_Wrapped
= Obj_Decl
then
8359 Set_BIP_Initialization_Call
(Obj_Def_Id
, Res_Decl
);
8362 Set_Expression
(Obj_Decl
, Empty
);
8363 Set_No_Initialization
(Obj_Decl
);
8365 -- In case of an indefinite result subtype, or if the call is the
8366 -- return expression of an enclosing BIP function, rewrite the object
8367 -- declaration as an object renaming where the renamed object is a
8368 -- dereference of <function_Call>'reference:
8370 -- Obj : Subt renames <function_call>'Ref.all;
8374 Make_Explicit_Dereference
(Obj_Loc
,
8375 Prefix
=> New_Occurrence_Of
(Def_Id
, Obj_Loc
));
8378 Make_Object_Renaming_Declaration
(Obj_Loc
,
8379 Defining_Identifier
=> Make_Temporary
(Obj_Loc
, 'D'),
8380 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Obj_Loc
),
8381 Name
=> Call_Deref
));
8383 Set_Renamed_Object
(Defining_Identifier
(Obj_Decl
), Call_Deref
);
8385 -- If the original entity comes from source, then mark the new
8386 -- entity as needing debug information, even though it's defined
8387 -- by a generated renaming that does not come from source, so that
8388 -- the Materialize_Entity flag will be set on the entity when
8389 -- Debug_Renaming_Declaration is called during analysis.
8391 if Comes_From_Source
(Obj_Def_Id
) then
8392 Set_Debug_Info_Needed
(Defining_Identifier
(Obj_Decl
));
8397 -- Replace the internal identifier of the renaming declaration's
8398 -- entity with identifier of the original object entity. We also have
8399 -- to exchange the entities containing their defining identifiers to
8400 -- ensure the correct replacement of the object declaration by the
8401 -- object renaming declaration to avoid homograph conflicts (since
8402 -- the object declaration's defining identifier was already entered
8403 -- in current scope). The Next_Entity links of the two entities also
8404 -- have to be swapped since the entities are part of the return
8405 -- scope's entity list and the list structure would otherwise be
8406 -- corrupted. Finally, the homonym chain must be preserved as well.
8409 Ren_Id
: constant Entity_Id
:= Defining_Entity
(Obj_Decl
);
8410 Next_Id
: constant Entity_Id
:= Next_Entity
(Ren_Id
);
8413 Set_Chars
(Ren_Id
, Chars
(Obj_Def_Id
));
8415 -- Swap next entity links in preparation for exchanging entities
8417 Set_Next_Entity
(Ren_Id
, Next_Entity
(Obj_Def_Id
));
8418 Set_Next_Entity
(Obj_Def_Id
, Next_Id
);
8419 Set_Homonym
(Ren_Id
, Homonym
(Obj_Def_Id
));
8421 Exchange_Entities
(Ren_Id
, Obj_Def_Id
);
8423 -- Preserve source indication of original declaration, so that
8424 -- xref information is properly generated for the right entity.
8426 Preserve_Comes_From_Source
(Obj_Decl
, Original_Node
(Obj_Decl
));
8427 Preserve_Comes_From_Source
(Obj_Def_Id
, Original_Node
(Obj_Decl
));
8429 Set_Comes_From_Source
(Ren_Id
, False);
8433 -- If the object entity has a class-wide Etype, then we need to change
8434 -- it to the result subtype of the function call, because otherwise the
8435 -- object will be class-wide without an explicit initialization and
8436 -- won't be allocated properly by the back end. It seems unclean to make
8437 -- such a revision to the type at this point, and we should try to
8438 -- improve this treatment when build-in-place functions with class-wide
8439 -- results are implemented. ???
8441 if Is_Class_Wide_Type
(Etype
(Defining_Identifier
(Obj_Decl
))) then
8442 Set_Etype
(Defining_Identifier
(Obj_Decl
), Result_Subt
);
8444 end Make_Build_In_Place_Call_In_Object_Declaration
;
8446 --------------------------------------------
8447 -- Make_CPP_Constructor_Call_In_Allocator --
8448 --------------------------------------------
8450 procedure Make_CPP_Constructor_Call_In_Allocator
8451 (Allocator
: Node_Id
;
8452 Function_Call
: Node_Id
)
8454 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8455 Acc_Type
: constant Entity_Id
:= Etype
(Allocator
);
8456 Function_Id
: constant Entity_Id
:= Entity
(Name
(Function_Call
));
8457 Result_Subt
: constant Entity_Id
:= Available_View
(Etype
(Function_Id
));
8459 New_Allocator
: Node_Id
;
8460 Return_Obj_Access
: Entity_Id
;
8464 pragma Assert
(Nkind
(Allocator
) = N_Allocator
8465 and then Nkind
(Function_Call
) = N_Function_Call
);
8466 pragma Assert
(Convention
(Function_Id
) = Convention_CPP
8467 and then Is_Constructor
(Function_Id
));
8468 pragma Assert
(Is_Constrained
(Underlying_Type
(Result_Subt
)));
8470 -- Replace the initialized allocator of form "new T'(Func (...))" with
8471 -- an uninitialized allocator of form "new T", where T is the result
8472 -- subtype of the called function. The call to the function is handled
8473 -- separately further below.
8476 Make_Allocator
(Loc
,
8477 Expression
=> New_Occurrence_Of
(Result_Subt
, Loc
));
8478 Set_No_Initialization
(New_Allocator
);
8480 -- Copy attributes to new allocator. Note that the new allocator
8481 -- logically comes from source if the original one did, so copy the
8482 -- relevant flag. This ensures proper treatment of the restriction
8483 -- No_Implicit_Heap_Allocations in this case.
8485 Set_Storage_Pool
(New_Allocator
, Storage_Pool
(Allocator
));
8486 Set_Procedure_To_Call
(New_Allocator
, Procedure_To_Call
(Allocator
));
8487 Set_Comes_From_Source
(New_Allocator
, Comes_From_Source
(Allocator
));
8489 Rewrite
(Allocator
, New_Allocator
);
8491 -- Create a new access object and initialize it to the result of the
8492 -- new uninitialized allocator. Note: we do not use Allocator as the
8493 -- Related_Node of Return_Obj_Access in call to Make_Temporary below
8494 -- as this would create a sort of infinite "recursion".
8496 Return_Obj_Access
:= Make_Temporary
(Loc
, 'R');
8497 Set_Etype
(Return_Obj_Access
, Acc_Type
);
8500 -- Rnnn : constant ptr_T := new (T);
8501 -- Init (Rnn.all,...);
8504 Make_Object_Declaration
(Loc
,
8505 Defining_Identifier
=> Return_Obj_Access
,
8506 Constant_Present
=> True,
8507 Object_Definition
=> New_Occurrence_Of
(Acc_Type
, Loc
),
8508 Expression
=> Relocate_Node
(Allocator
));
8509 Insert_Action
(Allocator
, Tmp_Obj
);
8511 Insert_List_After_And_Analyze
(Tmp_Obj
,
8512 Build_Initialization_Call
(Loc
,
8514 Make_Explicit_Dereference
(Loc
,
8515 Prefix
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
)),
8516 Typ
=> Etype
(Function_Id
),
8517 Constructor_Ref
=> Function_Call
));
8519 -- Finally, replace the allocator node with a reference to the result of
8520 -- the function call itself (which will effectively be an access to the
8521 -- object created by the allocator).
8523 Rewrite
(Allocator
, New_Occurrence_Of
(Return_Obj_Access
, Loc
));
8525 -- Ada 2005 (AI-251): If the type of the allocator is an interface then
8526 -- generate an implicit conversion to force displacement of the "this"
8529 if Is_Interface
(Designated_Type
(Acc_Type
)) then
8530 Rewrite
(Allocator
, Convert_To
(Acc_Type
, Relocate_Node
(Allocator
)));
8533 Analyze_And_Resolve
(Allocator
, Acc_Type
);
8534 end Make_CPP_Constructor_Call_In_Allocator
;
8536 -----------------------------------
8537 -- Needs_BIP_Finalization_Master --
8538 -----------------------------------
8540 function Needs_BIP_Finalization_Master
8541 (Func_Id
: Entity_Id
) return Boolean
8543 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
8544 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
8546 -- A formal giving the finalization master is needed for build-in-place
8547 -- functions whose result type needs finalization or is a tagged type.
8548 -- Tagged primitive build-in-place functions need such a formal because
8549 -- they can be called by a dispatching call, and extensions may require
8550 -- finalization even if the root type doesn't. This means they're also
8551 -- needed for tagged nonprimitive build-in-place functions with tagged
8552 -- results, since such functions can be called via access-to-function
8553 -- types, and those can be used to call primitives, so masters have to
8554 -- be passed to all such build-in-place functions, primitive or not.
8557 not Restriction_Active
(No_Finalization
)
8558 and then (Needs_Finalization
(Func_Typ
)
8559 or else Is_Tagged_Type
(Func_Typ
));
8560 end Needs_BIP_Finalization_Master
;
8562 --------------------------
8563 -- Needs_BIP_Alloc_Form --
8564 --------------------------
8566 function Needs_BIP_Alloc_Form
(Func_Id
: Entity_Id
) return Boolean is
8567 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
8568 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
8570 return not Is_Constrained
(Func_Typ
) or else Is_Tagged_Type
(Func_Typ
);
8571 end Needs_BIP_Alloc_Form
;
8573 --------------------------------------
8574 -- Needs_Result_Accessibility_Level --
8575 --------------------------------------
8577 function Needs_Result_Accessibility_Level
8578 (Func_Id
: Entity_Id
) return Boolean
8580 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
8582 function Has_Unconstrained_Access_Discriminant_Component
8583 (Comp_Typ
: Entity_Id
) return Boolean;
8584 -- Returns True if any component of the type has an unconstrained access
8587 -----------------------------------------------------
8588 -- Has_Unconstrained_Access_Discriminant_Component --
8589 -----------------------------------------------------
8591 function Has_Unconstrained_Access_Discriminant_Component
8592 (Comp_Typ
: Entity_Id
) return Boolean
8595 if not Is_Limited_Type
(Comp_Typ
) then
8598 -- Only limited types can have access discriminants with
8601 elsif Has_Unconstrained_Access_Discriminants
(Comp_Typ
) then
8604 elsif Is_Array_Type
(Comp_Typ
) then
8605 return Has_Unconstrained_Access_Discriminant_Component
8606 (Underlying_Type
(Component_Type
(Comp_Typ
)));
8608 elsif Is_Record_Type
(Comp_Typ
) then
8613 Comp
:= First_Component
(Comp_Typ
);
8614 while Present
(Comp
) loop
8615 if Has_Unconstrained_Access_Discriminant_Component
8616 (Underlying_Type
(Etype
(Comp
)))
8621 Next_Component
(Comp
);
8627 end Has_Unconstrained_Access_Discriminant_Component
;
8629 Feature_Disabled
: constant Boolean := True;
8632 -- Start of processing for Needs_Result_Accessibility_Level
8635 -- False if completion unavailable (how does this happen???)
8637 if not Present
(Func_Typ
) then
8640 elsif Feature_Disabled
then
8643 -- False if not a function, also handle enum-lit renames case
8645 elsif Func_Typ
= Standard_Void_Type
8646 or else Is_Scalar_Type
(Func_Typ
)
8650 -- Handle a corner case, a cross-dialect subp renaming. For example,
8651 -- an Ada 2012 renaming of an Ada 2005 subprogram. This can occur when
8652 -- an Ada 2005 (or earlier) unit references predefined run-time units.
8654 elsif Present
(Alias
(Func_Id
)) then
8656 -- Unimplemented: a cross-dialect subp renaming which does not set
8657 -- the Alias attribute (e.g., a rename of a dereference of an access
8658 -- to subprogram value). ???
8660 return Present
(Extra_Accessibility_Of_Result
(Alias
(Func_Id
)));
8662 -- Remaining cases require Ada 2012 mode
8664 elsif Ada_Version
< Ada_2012
then
8667 elsif Ekind
(Func_Typ
) = E_Anonymous_Access_Type
8668 or else Is_Tagged_Type
(Func_Typ
)
8670 -- In the case of, say, a null tagged record result type, the need
8671 -- for this extra parameter might not be obvious. This function
8672 -- returns True for all tagged types for compatibility reasons.
8673 -- A function with, say, a tagged null controlling result type might
8674 -- be overridden by a primitive of an extension having an access
8675 -- discriminant and the overrider and overridden must have compatible
8676 -- calling conventions (including implicitly declared parameters).
8677 -- Similarly, values of one access-to-subprogram type might designate
8678 -- both a primitive subprogram of a given type and a function
8679 -- which is, for example, not a primitive subprogram of any type.
8680 -- Again, this requires calling convention compatibility.
8681 -- It might be possible to solve these issues by introducing
8682 -- wrappers, but that is not the approach that was chosen.
8686 elsif Has_Unconstrained_Access_Discriminants
(Func_Typ
) then
8689 elsif Has_Unconstrained_Access_Discriminant_Component
(Func_Typ
) then
8692 -- False for all other cases
8697 end Needs_Result_Accessibility_Level
;
8699 ---------------------------------
8700 -- Rewrite_Function_Call_For_C --
8701 ---------------------------------
8703 procedure Rewrite_Function_Call_For_C
(N
: Node_Id
) is
8704 Orig_Func
: constant Entity_Id
:= Entity
(Name
(N
));
8705 Func_Id
: constant Entity_Id
:= Ultimate_Alias
(Orig_Func
);
8706 Par
: constant Node_Id
:= Parent
(N
);
8707 Proc_Id
: constant Entity_Id
:= Corresponding_Procedure
(Func_Id
);
8708 Loc
: constant Source_Ptr
:= Sloc
(Par
);
8710 Last_Actual
: Node_Id
;
8711 Last_Formal
: Entity_Id
;
8713 -- Start of processing for Rewrite_Function_Call_For_C
8716 -- The actuals may be given by named associations, so the added actual
8717 -- that is the target of the return value of the call must be a named
8718 -- association as well, so we retrieve the name of the generated
8721 Last_Formal
:= First_Formal
(Proc_Id
);
8722 while Present
(Next_Formal
(Last_Formal
)) loop
8723 Last_Formal
:= Next_Formal
(Last_Formal
);
8726 Actuals
:= Parameter_Associations
(N
);
8728 -- The original function may lack parameters
8730 if No
(Actuals
) then
8731 Actuals
:= New_List
;
8734 -- If the function call is the expression of an assignment statement,
8735 -- transform the assignment into a procedure call. Generate:
8737 -- LHS := Func_Call (...);
8739 -- Proc_Call (..., LHS);
8741 -- If function is inherited, a conversion may be necessary.
8743 if Nkind
(Par
) = N_Assignment_Statement
then
8744 Last_Actual
:= Name
(Par
);
8746 if not Comes_From_Source
(Orig_Func
)
8747 and then Etype
(Orig_Func
) /= Etype
(Func_Id
)
8750 Make_Type_Conversion
(Loc
,
8751 New_Occurrence_Of
(Etype
(Func_Id
), Loc
),
8756 Make_Parameter_Association
(Loc
,
8758 Make_Identifier
(Loc
, Chars
(Last_Formal
)),
8759 Explicit_Actual_Parameter
=> Last_Actual
));
8762 Make_Procedure_Call_Statement
(Loc
,
8763 Name
=> New_Occurrence_Of
(Proc_Id
, Loc
),
8764 Parameter_Associations
=> Actuals
));
8767 -- Otherwise the context is an expression. Generate a temporary and a
8768 -- procedure call to obtain the function result. Generate:
8770 -- ... Func_Call (...) ...
8773 -- Proc_Call (..., Temp);
8778 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
8787 Make_Object_Declaration
(Loc
,
8788 Defining_Identifier
=> Temp_Id
,
8789 Object_Definition
=>
8790 New_Occurrence_Of
(Etype
(Func_Id
), Loc
));
8793 -- Proc_Call (..., Temp);
8796 Make_Parameter_Association
(Loc
,
8798 Make_Identifier
(Loc
, Chars
(Last_Formal
)),
8799 Explicit_Actual_Parameter
=>
8800 New_Occurrence_Of
(Temp_Id
, Loc
)));
8803 Make_Procedure_Call_Statement
(Loc
,
8804 Name
=> New_Occurrence_Of
(Proc_Id
, Loc
),
8805 Parameter_Associations
=> Actuals
);
8807 Insert_Actions
(Par
, New_List
(Decl
, Call
));
8808 Rewrite
(N
, New_Occurrence_Of
(Temp_Id
, Loc
));
8811 end Rewrite_Function_Call_For_C
;
8813 ------------------------------------
8814 -- Set_Enclosing_Sec_Stack_Return --
8815 ------------------------------------
8817 procedure Set_Enclosing_Sec_Stack_Return
(N
: Node_Id
) is
8821 -- Due to a possible mix of internally generated blocks, source blocks
8822 -- and loops, the scope stack may not be contiguous as all labels are
8823 -- inserted at the top level within the related function. Instead,
8824 -- perform a parent-based traversal and mark all appropriate constructs.
8826 while Present
(P
) loop
8828 -- Mark the label of a source or internally generated block or
8831 if Nkind_In
(P
, N_Block_Statement
, N_Loop_Statement
) then
8832 Set_Sec_Stack_Needed_For_Return
(Entity
(Identifier
(P
)));
8834 -- Mark the enclosing function
8836 elsif Nkind
(P
) = N_Subprogram_Body
then
8837 if Present
(Corresponding_Spec
(P
)) then
8838 Set_Sec_Stack_Needed_For_Return
(Corresponding_Spec
(P
));
8840 Set_Sec_Stack_Needed_For_Return
(Defining_Entity
(P
));
8843 -- Do not go beyond the enclosing function
8850 end Set_Enclosing_Sec_Stack_Return
;