1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2018, 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 Aspects
; use Aspects
;
28 with Checks
; use Checks
;
29 with Contracts
; use Contracts
;
30 with Debug
; use Debug
;
31 with Einfo
; use Einfo
;
32 with Errout
; use Errout
;
33 with Elists
; use Elists
;
34 with Expander
; use Expander
;
35 with Exp_Aggr
; use Exp_Aggr
;
36 with Exp_Atag
; use Exp_Atag
;
37 with Exp_Ch2
; use Exp_Ch2
;
38 with Exp_Ch3
; use Exp_Ch3
;
39 with Exp_Ch7
; use Exp_Ch7
;
40 with Exp_Ch9
; use Exp_Ch9
;
41 with Exp_Dbug
; use Exp_Dbug
;
42 with Exp_Disp
; use Exp_Disp
;
43 with Exp_Dist
; use Exp_Dist
;
44 with Exp_Intr
; use Exp_Intr
;
45 with Exp_Pakd
; use Exp_Pakd
;
46 with Exp_Tss
; use Exp_Tss
;
47 with Exp_Util
; use Exp_Util
;
48 with Freeze
; use Freeze
;
49 with Inline
; use Inline
;
50 with Itypes
; use Itypes
;
52 with Namet
; use Namet
;
53 with Nlists
; use Nlists
;
54 with Nmake
; use Nmake
;
56 with Restrict
; use Restrict
;
57 with Rident
; use Rident
;
58 with Rtsfind
; use Rtsfind
;
60 with Sem_Aux
; use Sem_Aux
;
61 with Sem_Ch6
; use Sem_Ch6
;
62 with Sem_Ch8
; use Sem_Ch8
;
63 with Sem_Ch12
; use Sem_Ch12
;
64 with Sem_Ch13
; use Sem_Ch13
;
65 with Sem_Dim
; use Sem_Dim
;
66 with Sem_Disp
; use Sem_Disp
;
67 with Sem_Dist
; use Sem_Dist
;
68 with Sem_Eval
; use Sem_Eval
;
69 with Sem_Mech
; use Sem_Mech
;
70 with Sem_Res
; use Sem_Res
;
71 with Sem_SCIL
; use Sem_SCIL
;
72 with Sem_Util
; use Sem_Util
;
73 with Sinfo
; use Sinfo
;
74 with Snames
; use Snames
;
75 with Stand
; use Stand
;
76 with Tbuild
; use Tbuild
;
77 with Uintp
; use Uintp
;
78 with Validsw
; use Validsw
;
80 package body Exp_Ch6
is
82 -----------------------
83 -- Local Subprograms --
84 -----------------------
86 procedure Add_Access_Actual_To_Build_In_Place_Call
87 (Function_Call
: Node_Id
;
88 Function_Id
: Entity_Id
;
89 Return_Object
: Node_Id
;
90 Is_Access
: Boolean := False);
91 -- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
92 -- object name given by Return_Object and add the attribute to the end of
93 -- the actual parameter list associated with the build-in-place function
94 -- call denoted by Function_Call. However, if Is_Access is True, then
95 -- Return_Object is already an access expression, in which case it's passed
96 -- along directly to the build-in-place function. Finally, if Return_Object
97 -- is empty, then pass a null literal as the actual.
99 procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
100 (Function_Call
: Node_Id
;
101 Function_Id
: Entity_Id
;
102 Alloc_Form
: BIP_Allocation_Form
:= Unspecified
;
103 Alloc_Form_Exp
: Node_Id
:= Empty
;
104 Pool_Actual
: Node_Id
:= Make_Null
(No_Location
));
105 -- Ada 2005 (AI-318-02): Add the actuals needed for a build-in-place
106 -- function call that returns a caller-unknown-size result (BIP_Alloc_Form
107 -- and BIP_Storage_Pool). If Alloc_Form_Exp is present, then use it,
108 -- otherwise pass a literal corresponding to the Alloc_Form parameter
109 -- (which must not be Unspecified in that case). Pool_Actual is the
110 -- parameter to pass to BIP_Storage_Pool.
112 procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
113 (Func_Call
: Node_Id
;
115 Ptr_Typ
: Entity_Id
:= Empty
;
116 Master_Exp
: Node_Id
:= Empty
);
117 -- Ada 2005 (AI-318-02): If the result type of a build-in-place call needs
118 -- finalization actions, add an actual parameter which is a pointer to the
119 -- finalization master of the caller. If Master_Exp is not Empty, then that
120 -- will be passed as the actual. Otherwise, if Ptr_Typ is left Empty, this
121 -- will result in an automatic "null" value for the actual.
123 procedure Add_Task_Actuals_To_Build_In_Place_Call
124 (Function_Call
: Node_Id
;
125 Function_Id
: Entity_Id
;
126 Master_Actual
: Node_Id
;
127 Chain
: Node_Id
:= Empty
);
128 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
129 -- contains tasks, add two actual parameters: the master, and a pointer to
130 -- the caller's activation chain. Master_Actual is the actual parameter
131 -- expression to pass for the master. In most cases, this is the current
132 -- master (_master). The two exceptions are: If the function call is the
133 -- initialization expression for an allocator, we pass the master of the
134 -- access type. If the function call is the initialization expression for a
135 -- return object, we pass along the master passed in by the caller. In most
136 -- contexts, the activation chain to pass is the local one, which is
137 -- indicated by No (Chain). However, in an allocator, the caller passes in
138 -- the activation Chain. Note: Master_Actual can be Empty, but only if
139 -- there are no tasks.
141 function Caller_Known_Size
142 (Func_Call
: Node_Id
;
143 Result_Subt
: Entity_Id
) return Boolean;
144 -- True if result subtype is definite, or has a size that does not require
145 -- secondary stack usage (i.e. no variant part or components whose type
146 -- depends on discriminants). In particular, untagged types with only
147 -- access discriminants do not require secondary stack use. Note we must
148 -- always use the secondary stack for dispatching-on-result calls.
150 procedure Check_Overriding_Operation
(Subp
: Entity_Id
);
151 -- Subp is a dispatching operation. Check whether it may override an
152 -- inherited private operation, in which case its DT entry is that of
153 -- the hidden operation, not the one it may have received earlier.
154 -- This must be done before emitting the code to set the corresponding
155 -- DT to the address of the subprogram. The actual placement of Subp in
156 -- the proper place in the list of primitive operations is done in
157 -- Declare_Inherited_Private_Subprograms, which also has to deal with
158 -- implicit operations. This duplication is unavoidable for now???
160 procedure Detect_Infinite_Recursion
(N
: Node_Id
; Spec
: Entity_Id
);
161 -- This procedure is called only if the subprogram body N, whose spec
162 -- has the given entity Spec, contains a parameterless recursive call.
163 -- It attempts to generate runtime code to detect if this a case of
164 -- infinite recursion.
166 -- The body is scanned to determine dependencies. If the only external
167 -- dependencies are on a small set of scalar variables, then the values
168 -- of these variables are captured on entry to the subprogram, and if
169 -- the values are not changed for the call, we know immediately that
170 -- we have an infinite recursion.
172 procedure Expand_Actuals
175 Post_Call
: out List_Id
);
176 -- Return a list of actions to take place after the call in Post_Call. The
177 -- call will later be rewritten as an Expression_With_Actions, with the
178 -- Post_Call actions inserted, and the call inside.
180 -- For each actual of an in-out or out parameter which is a numeric (view)
181 -- conversion of the form T (A), where A denotes a variable, we insert the
184 -- Temp : T[ := T (A)];
186 -- prior to the call. Then we replace the actual with a reference to Temp,
187 -- and append the assignment:
189 -- A := TypeA (Temp);
191 -- after the call. Here TypeA is the actual type of variable A. For out
192 -- parameters, the initial declaration has no expression. If A is not an
193 -- entity name, we generate instead:
195 -- Var : TypeA renames A;
196 -- Temp : T := Var; -- omitting expression for out parameter.
198 -- Var := TypeA (Temp);
200 -- For other in-out parameters, we emit the required constraint checks
201 -- before and/or after the call.
203 -- For all parameter modes, actuals that denote components and slices of
204 -- packed arrays are expanded into suitable temporaries.
206 -- For non-scalar objects that are possibly unaligned, add call by copy
207 -- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
209 -- For OUT and IN OUT parameters, add predicate checks after the call
210 -- based on the predicates of the actual type.
212 procedure Expand_Call_Helper
(N
: Node_Id
; Post_Call
: out List_Id
);
213 -- Does the main work of Expand_Call. Post_Call is as for Expand_Actuals.
215 procedure Expand_Ctrl_Function_Call
(N
: Node_Id
);
216 -- N is a function call which returns a controlled object. Transform the
217 -- call into a temporary which retrieves the returned object from the
218 -- secondary stack using 'reference.
220 procedure Expand_Non_Function_Return
(N
: Node_Id
);
221 -- Expand a simple return statement found in a procedure body, entry body,
222 -- accept statement, or an extended return statement. Note that all non-
223 -- function returns are simple return statements.
225 function Expand_Protected_Object_Reference
227 Scop
: Entity_Id
) return Node_Id
;
229 procedure Expand_Protected_Subprogram_Call
233 -- A call to a protected subprogram within the protected object may appear
234 -- as a regular call. The list of actuals must be expanded to contain a
235 -- reference to the object itself, and the call becomes a call to the
236 -- corresponding protected subprogram.
238 procedure Expand_Simple_Function_Return
(N
: Node_Id
);
239 -- Expand simple return from function. In the case where we are returning
240 -- from a function body this is called by Expand_N_Simple_Return_Statement.
242 function Has_Unconstrained_Access_Discriminants
243 (Subtyp
: Entity_Id
) return Boolean;
244 -- Returns True if the given subtype is unconstrained and has one or more
245 -- access discriminants.
247 procedure Insert_Post_Call_Actions
(N
: Node_Id
; Post_Call
: List_Id
);
248 -- Insert the Post_Call list previously produced by routine Expand_Actuals
249 -- or Expand_Call_Helper into the tree.
251 procedure Replace_Renaming_Declaration_Id
253 Orig_Decl
: Node_Id
);
254 -- Replace the internal identifier of the new renaming declaration New_Decl
255 -- with the identifier of its original declaration Orig_Decl exchanging the
256 -- entities containing their defining identifiers to ensure the correct
257 -- replacement of the object declaration by the object renaming declaration
258 -- to avoid homograph conflicts (since the object declaration's defining
259 -- identifier was already entered in the current scope). The Next_Entity
260 -- links of the two entities are also swapped since the entities are part
261 -- of the return scope's entity list and the list structure would otherwise
262 -- be corrupted. The homonym chain is preserved as well.
264 procedure Rewrite_Function_Call_For_C
(N
: Node_Id
);
265 -- When generating C code, replace a call to a function that returns an
266 -- array into the generated procedure with an additional out parameter.
268 procedure Set_Enclosing_Sec_Stack_Return
(N
: Node_Id
);
269 -- N is a return statement for a function that returns its result on the
270 -- secondary stack. This sets the Sec_Stack_Needed_For_Return flag on the
271 -- function and all blocks and loops that the return statement is jumping
272 -- out of. This ensures that the secondary stack is not released; otherwise
273 -- the function result would be reclaimed before returning to the caller.
275 ----------------------------------------------
276 -- Add_Access_Actual_To_Build_In_Place_Call --
277 ----------------------------------------------
279 procedure Add_Access_Actual_To_Build_In_Place_Call
280 (Function_Call
: Node_Id
;
281 Function_Id
: Entity_Id
;
282 Return_Object
: Node_Id
;
283 Is_Access
: Boolean := False)
285 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
286 Obj_Address
: Node_Id
;
287 Obj_Acc_Formal
: Entity_Id
;
290 -- Locate the implicit access parameter in the called function
292 Obj_Acc_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Object_Access
);
294 -- If no return object is provided, then pass null
296 if not Present
(Return_Object
) then
297 Obj_Address
:= Make_Null
(Loc
);
298 Set_Parent
(Obj_Address
, Function_Call
);
300 -- If Return_Object is already an expression of an access type, then use
301 -- it directly, since it must be an access value denoting the return
302 -- object, and couldn't possibly be the return object itself.
305 Obj_Address
:= Return_Object
;
306 Set_Parent
(Obj_Address
, Function_Call
);
308 -- Apply Unrestricted_Access to caller's return object
312 Make_Attribute_Reference
(Loc
,
313 Prefix
=> Return_Object
,
314 Attribute_Name
=> Name_Unrestricted_Access
);
316 Set_Parent
(Return_Object
, Obj_Address
);
317 Set_Parent
(Obj_Address
, Function_Call
);
320 Analyze_And_Resolve
(Obj_Address
, Etype
(Obj_Acc_Formal
));
322 -- Build the parameter association for the new actual and add it to the
323 -- end of the function's actuals.
325 Add_Extra_Actual_To_Call
(Function_Call
, Obj_Acc_Formal
, Obj_Address
);
326 end Add_Access_Actual_To_Build_In_Place_Call
;
328 ------------------------------------------------------
329 -- Add_Unconstrained_Actuals_To_Build_In_Place_Call --
330 ------------------------------------------------------
332 procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
333 (Function_Call
: Node_Id
;
334 Function_Id
: Entity_Id
;
335 Alloc_Form
: BIP_Allocation_Form
:= Unspecified
;
336 Alloc_Form_Exp
: Node_Id
:= Empty
;
337 Pool_Actual
: Node_Id
:= Make_Null
(No_Location
))
339 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
341 Alloc_Form_Actual
: Node_Id
;
342 Alloc_Form_Formal
: Node_Id
;
343 Pool_Formal
: Node_Id
;
346 -- Nothing to do when the size of the object is known, and the caller is
347 -- in charge of allocating it, and the callee doesn't unconditionally
348 -- require an allocation form (such as due to having a tagged result).
350 if not Needs_BIP_Alloc_Form
(Function_Id
) then
354 -- Locate the implicit allocation form parameter in the called function.
355 -- Maybe it would be better for each implicit formal of a build-in-place
356 -- function to have a flag or a Uint attribute to identify it. ???
358 Alloc_Form_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Alloc_Form
);
360 if Present
(Alloc_Form_Exp
) then
361 pragma Assert
(Alloc_Form
= Unspecified
);
363 Alloc_Form_Actual
:= Alloc_Form_Exp
;
366 pragma Assert
(Alloc_Form
/= Unspecified
);
369 Make_Integer_Literal
(Loc
,
370 Intval
=> UI_From_Int
(BIP_Allocation_Form
'Pos (Alloc_Form
)));
373 Analyze_And_Resolve
(Alloc_Form_Actual
, Etype
(Alloc_Form_Formal
));
375 -- Build the parameter association for the new actual and add it to the
376 -- end of the function's actuals.
378 Add_Extra_Actual_To_Call
379 (Function_Call
, Alloc_Form_Formal
, Alloc_Form_Actual
);
381 -- Pass the Storage_Pool parameter. This parameter is omitted on ZFP as
382 -- those targets do not support pools.
384 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
385 Pool_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Storage_Pool
);
386 Analyze_And_Resolve
(Pool_Actual
, Etype
(Pool_Formal
));
387 Add_Extra_Actual_To_Call
388 (Function_Call
, Pool_Formal
, Pool_Actual
);
390 end Add_Unconstrained_Actuals_To_Build_In_Place_Call
;
392 -----------------------------------------------------------
393 -- Add_Finalization_Master_Actual_To_Build_In_Place_Call --
394 -----------------------------------------------------------
396 procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
397 (Func_Call
: Node_Id
;
399 Ptr_Typ
: Entity_Id
:= Empty
;
400 Master_Exp
: Node_Id
:= Empty
)
403 if not Needs_BIP_Finalization_Master
(Func_Id
) then
408 Formal
: constant Entity_Id
:=
409 Build_In_Place_Formal
(Func_Id
, BIP_Finalization_Master
);
410 Loc
: constant Source_Ptr
:= Sloc
(Func_Call
);
413 Desig_Typ
: Entity_Id
;
416 -- If there is a finalization master actual, such as the implicit
417 -- finalization master of an enclosing build-in-place function,
418 -- then this must be added as an extra actual of the call.
420 if Present
(Master_Exp
) then
421 Actual
:= Master_Exp
;
423 -- Case where the context does not require an actual master
425 elsif No
(Ptr_Typ
) then
426 Actual
:= Make_Null
(Loc
);
429 Desig_Typ
:= Directly_Designated_Type
(Ptr_Typ
);
431 -- Check for a library-level access type whose designated type has
432 -- suppressed finalization or the access type is subject to pragma
433 -- No_Heap_Finalization. Such an access type lacks a master. Pass
434 -- a null actual to callee in order to signal a missing master.
436 if Is_Library_Level_Entity
(Ptr_Typ
)
437 and then (Finalize_Storage_Only
(Desig_Typ
)
438 or else No_Heap_Finalization
(Ptr_Typ
))
440 Actual
:= Make_Null
(Loc
);
442 -- Types in need of finalization actions
444 elsif Needs_Finalization
(Desig_Typ
) then
446 -- The general mechanism of creating finalization masters for
447 -- anonymous access types is disabled by default, otherwise
448 -- finalization masters will pop all over the place. Such types
449 -- use context-specific masters.
451 if Ekind
(Ptr_Typ
) = E_Anonymous_Access_Type
452 and then No
(Finalization_Master
(Ptr_Typ
))
454 Build_Anonymous_Master
(Ptr_Typ
);
457 -- Access-to-controlled types should always have a master
459 pragma Assert
(Present
(Finalization_Master
(Ptr_Typ
)));
462 Make_Attribute_Reference
(Loc
,
464 New_Occurrence_Of
(Finalization_Master
(Ptr_Typ
), Loc
),
465 Attribute_Name
=> Name_Unrestricted_Access
);
470 Actual
:= Make_Null
(Loc
);
474 Analyze_And_Resolve
(Actual
, Etype
(Formal
));
476 -- Build the parameter association for the new actual and add it to
477 -- the end of the function's actuals.
479 Add_Extra_Actual_To_Call
(Func_Call
, Formal
, Actual
);
481 end Add_Finalization_Master_Actual_To_Build_In_Place_Call
;
483 ------------------------------
484 -- Add_Extra_Actual_To_Call --
485 ------------------------------
487 procedure Add_Extra_Actual_To_Call
488 (Subprogram_Call
: Node_Id
;
489 Extra_Formal
: Entity_Id
;
490 Extra_Actual
: Node_Id
)
492 Loc
: constant Source_Ptr
:= Sloc
(Subprogram_Call
);
493 Param_Assoc
: Node_Id
;
497 Make_Parameter_Association
(Loc
,
498 Selector_Name
=> New_Occurrence_Of
(Extra_Formal
, Loc
),
499 Explicit_Actual_Parameter
=> Extra_Actual
);
501 Set_Parent
(Param_Assoc
, Subprogram_Call
);
502 Set_Parent
(Extra_Actual
, Param_Assoc
);
504 if Present
(Parameter_Associations
(Subprogram_Call
)) then
505 if Nkind
(Last
(Parameter_Associations
(Subprogram_Call
))) =
506 N_Parameter_Association
509 -- Find last named actual, and append
514 L
:= First_Actual
(Subprogram_Call
);
515 while Present
(L
) loop
516 if No
(Next_Actual
(L
)) then
517 Set_Next_Named_Actual
(Parent
(L
), Extra_Actual
);
525 Set_First_Named_Actual
(Subprogram_Call
, Extra_Actual
);
528 Append
(Param_Assoc
, To
=> Parameter_Associations
(Subprogram_Call
));
531 Set_Parameter_Associations
(Subprogram_Call
, New_List
(Param_Assoc
));
532 Set_First_Named_Actual
(Subprogram_Call
, Extra_Actual
);
534 end Add_Extra_Actual_To_Call
;
536 ---------------------------------------------
537 -- Add_Task_Actuals_To_Build_In_Place_Call --
538 ---------------------------------------------
540 procedure Add_Task_Actuals_To_Build_In_Place_Call
541 (Function_Call
: Node_Id
;
542 Function_Id
: Entity_Id
;
543 Master_Actual
: Node_Id
;
544 Chain
: Node_Id
:= Empty
)
546 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
547 Result_Subt
: constant Entity_Id
:=
548 Available_View
(Etype
(Function_Id
));
550 Chain_Actual
: Node_Id
;
551 Chain_Formal
: Node_Id
;
552 Master_Formal
: Node_Id
;
555 -- No such extra parameters are needed if there are no tasks
557 if not Has_Task
(Result_Subt
) then
561 Actual
:= Master_Actual
;
563 -- Use a dummy _master actual in case of No_Task_Hierarchy
565 if Restriction_Active
(No_Task_Hierarchy
) then
566 Actual
:= New_Occurrence_Of
(RTE
(RE_Library_Task_Level
), Loc
);
568 -- In the case where we use the master associated with an access type,
569 -- the actual is an entity and requires an explicit reference.
571 elsif Nkind
(Actual
) = N_Defining_Identifier
then
572 Actual
:= New_Occurrence_Of
(Actual
, Loc
);
575 -- Locate the implicit master parameter in the called function
577 Master_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Task_Master
);
578 Analyze_And_Resolve
(Actual
, Etype
(Master_Formal
));
580 -- Build the parameter association for the new actual and add it to the
581 -- end of the function's actuals.
583 Add_Extra_Actual_To_Call
(Function_Call
, Master_Formal
, Actual
);
585 -- Locate the implicit activation chain parameter in the called function
588 Build_In_Place_Formal
(Function_Id
, BIP_Activation_Chain
);
590 -- Create the actual which is a pointer to the current activation chain
594 Make_Attribute_Reference
(Loc
,
595 Prefix
=> Make_Identifier
(Loc
, Name_uChain
),
596 Attribute_Name
=> Name_Unrestricted_Access
);
598 -- Allocator case; make a reference to the Chain passed in by the caller
602 Make_Attribute_Reference
(Loc
,
603 Prefix
=> New_Occurrence_Of
(Chain
, Loc
),
604 Attribute_Name
=> Name_Unrestricted_Access
);
607 Analyze_And_Resolve
(Chain_Actual
, Etype
(Chain_Formal
));
609 -- Build the parameter association for the new actual and add it to the
610 -- end of the function's actuals.
612 Add_Extra_Actual_To_Call
(Function_Call
, Chain_Formal
, Chain_Actual
);
613 end Add_Task_Actuals_To_Build_In_Place_Call
;
615 -----------------------
616 -- BIP_Formal_Suffix --
617 -----------------------
619 function BIP_Formal_Suffix
(Kind
: BIP_Formal_Kind
) return String is
622 when BIP_Alloc_Form
=>
625 when BIP_Storage_Pool
=>
626 return "BIPstoragepool";
628 when BIP_Finalization_Master
=>
629 return "BIPfinalizationmaster";
631 when BIP_Task_Master
=>
632 return "BIPtaskmaster";
634 when BIP_Activation_Chain
=>
635 return "BIPactivationchain";
637 when BIP_Object_Access
=>
640 end BIP_Formal_Suffix
;
642 ---------------------------
643 -- Build_In_Place_Formal --
644 ---------------------------
646 function Build_In_Place_Formal
648 Kind
: BIP_Formal_Kind
) return Entity_Id
650 Formal_Suffix
: constant String := BIP_Formal_Suffix
(Kind
);
651 Extra_Formal
: Entity_Id
:= Extra_Formals
(Func
);
654 -- Maybe it would be better for each implicit formal of a build-in-place
655 -- function to have a flag or a Uint attribute to identify it. ???
657 -- The return type in the function declaration may have been a limited
658 -- view, and the extra formals for the function were not generated at
659 -- that point. At the point of call the full view must be available and
660 -- the extra formals can be created.
662 if No
(Extra_Formal
) then
663 Create_Extra_Formals
(Func
);
664 Extra_Formal
:= Extra_Formals
(Func
);
667 -- We search for a formal with a matching suffix. We can't search
668 -- for the full name, because of the code at the end of Sem_Ch6.-
669 -- Create_Extra_Formals, which copies the Extra_Formals over to
670 -- the Alias of an instance, which will cause the formals to have
671 -- "incorrect" names.
674 pragma Assert
(Present
(Extra_Formal
));
676 Name
: constant String := Get_Name_String
(Chars
(Extra_Formal
));
678 exit when Name
'Length >= Formal_Suffix
'Length
679 and then Formal_Suffix
=
680 Name
(Name
'Last - Formal_Suffix
'Length + 1 .. Name
'Last);
683 Next_Formal_With_Extras
(Extra_Formal
);
687 end Build_In_Place_Formal
;
689 -------------------------------
690 -- Build_Procedure_Body_Form --
691 -------------------------------
693 function Build_Procedure_Body_Form
694 (Func_Id
: Entity_Id
;
695 Func_Body
: Node_Id
) return Node_Id
697 Loc
: constant Source_Ptr
:= Sloc
(Func_Body
);
699 Proc_Decl
: constant Node_Id
:=
700 Next
(Unit_Declaration_Node
(Func_Id
));
701 -- It is assumed that the next node following the declaration of the
702 -- corresponding subprogram spec is the declaration of the procedure
705 Proc_Id
: constant Entity_Id
:= Defining_Entity
(Proc_Decl
);
707 procedure Replace_Returns
(Param_Id
: Entity_Id
; Stmts
: List_Id
);
708 -- Replace each return statement found in the list Stmts with an
709 -- assignment of the return expression to parameter Param_Id.
711 ---------------------
712 -- Replace_Returns --
713 ---------------------
715 procedure Replace_Returns
(Param_Id
: Entity_Id
; Stmts
: List_Id
) is
719 Stmt
:= First
(Stmts
);
720 while Present
(Stmt
) loop
721 if Nkind
(Stmt
) = N_Block_Statement
then
722 Replace_Returns
(Param_Id
,
723 Statements
(Handled_Statement_Sequence
(Stmt
)));
725 elsif Nkind
(Stmt
) = N_Case_Statement
then
729 Alt
:= First
(Alternatives
(Stmt
));
730 while Present
(Alt
) loop
731 Replace_Returns
(Param_Id
, Statements
(Alt
));
736 elsif Nkind
(Stmt
) = N_Extended_Return_Statement
then
738 Ret_Obj
: constant Entity_Id
:=
740 (First
(Return_Object_Declarations
(Stmt
)));
741 Assign
: constant Node_Id
:=
742 Make_Assignment_Statement
(Sloc
(Stmt
),
744 New_Occurrence_Of
(Param_Id
, Loc
),
746 New_Occurrence_Of
(Ret_Obj
, Sloc
(Stmt
)));
750 -- The extended return may just contain the declaration
752 if Present
(Handled_Statement_Sequence
(Stmt
)) then
753 Stmts
:= Statements
(Handled_Statement_Sequence
(Stmt
));
758 Set_Assignment_OK
(Name
(Assign
));
761 Make_Block_Statement
(Sloc
(Stmt
),
763 Return_Object_Declarations
(Stmt
),
764 Handled_Statement_Sequence
=>
765 Make_Handled_Sequence_Of_Statements
(Loc
,
766 Statements
=> Stmts
)));
768 Replace_Returns
(Param_Id
, Stmts
);
770 Append_To
(Stmts
, Assign
);
771 Append_To
(Stmts
, Make_Simple_Return_Statement
(Loc
));
774 elsif Nkind
(Stmt
) = N_If_Statement
then
775 Replace_Returns
(Param_Id
, Then_Statements
(Stmt
));
776 Replace_Returns
(Param_Id
, Else_Statements
(Stmt
));
781 Part
:= First
(Elsif_Parts
(Stmt
));
782 while Present
(Part
) loop
783 Replace_Returns
(Param_Id
, Then_Statements
(Part
));
788 elsif Nkind
(Stmt
) = N_Loop_Statement
then
789 Replace_Returns
(Param_Id
, Statements
(Stmt
));
791 elsif Nkind
(Stmt
) = N_Simple_Return_Statement
then
798 Make_Assignment_Statement
(Sloc
(Stmt
),
799 Name
=> New_Occurrence_Of
(Param_Id
, Loc
),
800 Expression
=> Relocate_Node
(Expression
(Stmt
))));
802 Insert_After
(Stmt
, Make_Simple_Return_Statement
(Loc
));
804 -- Skip the added return
818 -- Start of processing for Build_Procedure_Body_Form
821 -- This routine replaces the original function body:
823 -- function F (...) return Array_Typ is
829 -- with the following:
831 -- procedure P (..., Result : out Array_Typ) is
834 -- Result := Something;
838 Statements
(Handled_Statement_Sequence
(Func_Body
));
839 Replace_Returns
(Last_Entity
(Proc_Id
), Stmts
);
842 Make_Subprogram_Body
(Loc
,
844 Copy_Subprogram_Spec
(Specification
(Proc_Decl
)),
845 Declarations
=> Declarations
(Func_Body
),
846 Handled_Statement_Sequence
=>
847 Make_Handled_Sequence_Of_Statements
(Loc
,
848 Statements
=> Stmts
));
850 -- If the function is a generic instance, so is the new procedure.
851 -- Set flag accordingly so that the proper renaming declarations are
854 Set_Is_Generic_Instance
(Proc_Id
, Is_Generic_Instance
(Func_Id
));
856 end Build_Procedure_Body_Form
;
858 -----------------------
859 -- Caller_Known_Size --
860 -----------------------
862 function Caller_Known_Size
863 (Func_Call
: Node_Id
;
864 Result_Subt
: Entity_Id
) return Boolean
868 (Is_Definite_Subtype
(Underlying_Type
(Result_Subt
))
869 and then No
(Controlling_Argument
(Func_Call
)))
870 or else not Requires_Transient_Scope
(Underlying_Type
(Result_Subt
));
871 end Caller_Known_Size
;
873 --------------------------------
874 -- Check_Overriding_Operation --
875 --------------------------------
877 procedure Check_Overriding_Operation
(Subp
: Entity_Id
) is
878 Typ
: constant Entity_Id
:= Find_Dispatching_Type
(Subp
);
879 Op_List
: constant Elist_Id
:= Primitive_Operations
(Typ
);
885 if Is_Derived_Type
(Typ
)
886 and then not Is_Private_Type
(Typ
)
887 and then In_Open_Scopes
(Scope
(Etype
(Typ
)))
888 and then Is_Base_Type
(Typ
)
890 -- Subp overrides an inherited private operation if there is an
891 -- inherited operation with a different name than Subp (see
892 -- Derive_Subprogram) whose Alias is a hidden subprogram with the
893 -- same name as Subp.
895 Op_Elmt
:= First_Elmt
(Op_List
);
896 while Present
(Op_Elmt
) loop
897 Prim_Op
:= Node
(Op_Elmt
);
898 Par_Op
:= Alias
(Prim_Op
);
901 and then not Comes_From_Source
(Prim_Op
)
902 and then Chars
(Prim_Op
) /= Chars
(Par_Op
)
903 and then Chars
(Par_Op
) = Chars
(Subp
)
904 and then Is_Hidden
(Par_Op
)
905 and then Type_Conformant
(Prim_Op
, Subp
)
907 Set_DT_Position_Value
(Subp
, DT_Position
(Prim_Op
));
913 end Check_Overriding_Operation
;
915 -------------------------------
916 -- Detect_Infinite_Recursion --
917 -------------------------------
919 procedure Detect_Infinite_Recursion
(N
: Node_Id
; Spec
: Entity_Id
) is
920 Loc
: constant Source_Ptr
:= Sloc
(N
);
922 Var_List
: constant Elist_Id
:= New_Elmt_List
;
923 -- List of globals referenced by body of procedure
925 Call_List
: constant Elist_Id
:= New_Elmt_List
;
926 -- List of recursive calls in body of procedure
928 Shad_List
: constant Elist_Id
:= New_Elmt_List
;
929 -- List of entity id's for entities created to capture the value of
930 -- referenced globals on entry to the procedure.
932 Scop
: constant Uint
:= Scope_Depth
(Spec
);
933 -- This is used to record the scope depth of the current procedure, so
934 -- that we can identify global references.
936 Max_Vars
: constant := 4;
937 -- Do not test more than four global variables
939 Count_Vars
: Natural := 0;
940 -- Count variables found so far
952 function Process
(Nod
: Node_Id
) return Traverse_Result
;
953 -- Function to traverse the subprogram body (using Traverse_Func)
959 function Process
(Nod
: Node_Id
) return Traverse_Result
is
963 if Nkind
(Nod
) = N_Procedure_Call_Statement
then
965 -- Case of one of the detected recursive calls
967 if Is_Entity_Name
(Name
(Nod
))
968 and then Has_Recursive_Call
(Entity
(Name
(Nod
)))
969 and then Entity
(Name
(Nod
)) = Spec
971 Append_Elmt
(Nod
, Call_List
);
974 -- Any other procedure call may have side effects
980 -- A call to a pure function can always be ignored
982 elsif Nkind
(Nod
) = N_Function_Call
983 and then Is_Entity_Name
(Name
(Nod
))
984 and then Is_Pure
(Entity
(Name
(Nod
)))
988 -- Case of an identifier reference
990 elsif Nkind
(Nod
) = N_Identifier
then
993 -- If no entity, then ignore the reference
995 -- Not clear why this can happen. To investigate, remove this
996 -- test and look at the crash that occurs here in 3401-004 ???
1001 -- Ignore entities with no Scope, again not clear how this
1002 -- can happen, to investigate, look at 4108-008 ???
1004 elsif No
(Scope
(Ent
)) then
1007 -- Ignore the reference if not to a more global object
1009 elsif Scope_Depth
(Scope
(Ent
)) >= Scop
then
1012 -- References to types, exceptions and constants are always OK
1015 or else Ekind
(Ent
) = E_Exception
1016 or else Ekind
(Ent
) = E_Constant
1020 -- If other than a non-volatile scalar variable, we have some
1021 -- kind of global reference (e.g. to a function) that we cannot
1022 -- deal with so we forget the attempt.
1024 elsif Ekind
(Ent
) /= E_Variable
1025 or else not Is_Scalar_Type
(Etype
(Ent
))
1026 or else Treat_As_Volatile
(Ent
)
1030 -- Otherwise we have a reference to a global scalar
1033 -- Loop through global entities already detected
1035 Elm
:= First_Elmt
(Var_List
);
1037 -- If not detected before, record this new global reference
1040 Count_Vars
:= Count_Vars
+ 1;
1042 if Count_Vars
<= Max_Vars
then
1043 Append_Elmt
(Entity
(Nod
), Var_List
);
1050 -- If recorded before, ignore
1052 elsif Node
(Elm
) = Entity
(Nod
) then
1055 -- Otherwise keep looking
1065 -- For all other node kinds, recursively visit syntactic children
1072 function Traverse_Body
is new Traverse_Func
(Process
);
1074 -- Start of processing for Detect_Infinite_Recursion
1077 -- Do not attempt detection in No_Implicit_Conditional mode, since we
1078 -- won't be able to generate the code to handle the recursion in any
1081 if Restriction_Active
(No_Implicit_Conditionals
) then
1085 -- Otherwise do traversal and quit if we get abandon signal
1087 if Traverse_Body
(N
) = Abandon
then
1090 -- We must have a call, since Has_Recursive_Call was set. If not just
1091 -- ignore (this is only an error check, so if we have a funny situation,
1092 -- due to bugs or errors, we do not want to bomb).
1094 elsif Is_Empty_Elmt_List
(Call_List
) then
1098 -- Here is the case where we detect recursion at compile time
1100 -- Push our current scope for analyzing the declarations and code that
1101 -- we will insert for the checking.
1105 -- This loop builds temporary variables for each of the referenced
1106 -- globals, so that at the end of the loop the list Shad_List contains
1107 -- these temporaries in one-to-one correspondence with the elements in
1111 Elm
:= First_Elmt
(Var_List
);
1112 while Present
(Elm
) loop
1114 Ent
:= Make_Temporary
(Loc
, 'S');
1115 Append_Elmt
(Ent
, Shad_List
);
1117 -- Insert a declaration for this temporary at the start of the
1118 -- declarations for the procedure. The temporaries are declared as
1119 -- constant objects initialized to the current values of the
1120 -- corresponding temporaries.
1123 Make_Object_Declaration
(Loc
,
1124 Defining_Identifier
=> Ent
,
1125 Object_Definition
=> New_Occurrence_Of
(Etype
(Var
), Loc
),
1126 Constant_Present
=> True,
1127 Expression
=> New_Occurrence_Of
(Var
, Loc
));
1130 Prepend
(Decl
, Declarations
(N
));
1132 Insert_After
(Last
, Decl
);
1140 -- Loop through calls
1142 Call
:= First_Elmt
(Call_List
);
1143 while Present
(Call
) loop
1145 -- Build a predicate expression of the form
1148 -- and then global1 = temp1
1149 -- and then global2 = temp2
1152 -- This predicate determines if any of the global values
1153 -- referenced by the procedure have changed since the
1154 -- current call, if not an infinite recursion is assured.
1156 Test
:= New_Occurrence_Of
(Standard_True
, Loc
);
1158 Elm1
:= First_Elmt
(Var_List
);
1159 Elm2
:= First_Elmt
(Shad_List
);
1160 while Present
(Elm1
) loop
1166 Left_Opnd
=> New_Occurrence_Of
(Node
(Elm1
), Loc
),
1167 Right_Opnd
=> New_Occurrence_Of
(Node
(Elm2
), Loc
)));
1173 -- Now we replace the call with the sequence
1175 -- if no-changes (see above) then
1176 -- raise Storage_Error;
1181 Rewrite
(Node
(Call
),
1182 Make_If_Statement
(Loc
,
1184 Then_Statements
=> New_List
(
1185 Make_Raise_Storage_Error
(Loc
,
1186 Reason
=> SE_Infinite_Recursion
)),
1188 Else_Statements
=> New_List
(
1189 Relocate_Node
(Node
(Call
)))));
1191 Analyze
(Node
(Call
));
1196 -- Remove temporary scope stack entry used for analysis
1199 end Detect_Infinite_Recursion
;
1201 --------------------
1202 -- Expand_Actuals --
1203 --------------------
1205 procedure Expand_Actuals
1208 Post_Call
: out List_Id
)
1210 Loc
: constant Source_Ptr
:= Sloc
(N
);
1214 E_Actual
: Entity_Id
;
1215 E_Formal
: Entity_Id
;
1217 procedure Add_Call_By_Copy_Code
;
1218 -- For cases where the parameter must be passed by copy, this routine
1219 -- generates a temporary variable into which the actual is copied and
1220 -- then passes this as the parameter. For an OUT or IN OUT parameter,
1221 -- an assignment is also generated to copy the result back. The call
1222 -- also takes care of any constraint checks required for the type
1223 -- conversion case (on both the way in and the way out).
1225 procedure Add_Simple_Call_By_Copy_Code
;
1226 -- This is similar to the above, but is used in cases where we know
1227 -- that all that is needed is to simply create a temporary and copy
1228 -- the value in and out of the temporary.
1230 procedure Add_Validation_Call_By_Copy_Code
(Act
: Node_Id
);
1231 -- Perform copy-back for actual parameter Act which denotes a validation
1234 procedure Check_Fortran_Logical
;
1235 -- A value of type Logical that is passed through a formal parameter
1236 -- must be normalized because .TRUE. usually does not have the same
1237 -- representation as True. We assume that .FALSE. = False = 0.
1238 -- What about functions that return a logical type ???
1240 function Is_Legal_Copy
return Boolean;
1241 -- Check that an actual can be copied before generating the temporary
1242 -- to be used in the call. If the actual is of a by_reference type then
1243 -- the program is illegal (this can only happen in the presence of
1244 -- rep. clauses that force an incorrect alignment). If the formal is
1245 -- a by_reference parameter imposed by a DEC pragma, emit a warning to
1246 -- the effect that this might lead to unaligned arguments.
1248 function Make_Var
(Actual
: Node_Id
) return Entity_Id
;
1249 -- Returns an entity that refers to the given actual parameter, Actual
1250 -- (not including any type conversion). If Actual is an entity name,
1251 -- then this entity is returned unchanged, otherwise a renaming is
1252 -- created to provide an entity for the actual.
1254 procedure Reset_Packed_Prefix
;
1255 -- The expansion of a packed array component reference is delayed in
1256 -- the context of a call. Now we need to complete the expansion, so we
1257 -- unmark the analyzed bits in all prefixes.
1259 ---------------------------
1260 -- Add_Call_By_Copy_Code --
1261 ---------------------------
1263 procedure Add_Call_By_Copy_Code
is
1266 F_Typ
: Entity_Id
:= Etype
(Formal
);
1274 if not Is_Legal_Copy
then
1278 Temp
:= Make_Temporary
(Loc
, 'T', Actual
);
1280 -- Handle formals whose type comes from the limited view
1282 if From_Limited_With
(F_Typ
)
1283 and then Has_Non_Limited_View
(F_Typ
)
1285 F_Typ
:= Non_Limited_View
(F_Typ
);
1288 -- Use formal type for temp, unless formal type is an unconstrained
1289 -- array, in which case we don't have to worry about bounds checks,
1290 -- and we use the actual type, since that has appropriate bounds.
1292 if Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
) then
1293 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1295 Indic
:= New_Occurrence_Of
(F_Typ
, Loc
);
1298 if Nkind
(Actual
) = N_Type_Conversion
then
1299 V_Typ
:= Etype
(Expression
(Actual
));
1301 -- If the formal is an (in-)out parameter, capture the name
1302 -- of the variable in order to build the post-call assignment.
1304 Var
:= Make_Var
(Expression
(Actual
));
1306 Crep
:= not Same_Representation
1307 (F_Typ
, Etype
(Expression
(Actual
)));
1310 V_Typ
:= Etype
(Actual
);
1311 Var
:= Make_Var
(Actual
);
1315 -- Setup initialization for case of in out parameter, or an out
1316 -- parameter where the formal is an unconstrained array (in the
1317 -- latter case, we have to pass in an object with bounds).
1319 -- If this is an out parameter, the initial copy is wasteful, so as
1320 -- an optimization for the one-dimensional case we extract the
1321 -- bounds of the actual and build an uninitialized temporary of the
1324 if Ekind
(Formal
) = E_In_Out_Parameter
1325 or else (Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
))
1327 if Nkind
(Actual
) = N_Type_Conversion
then
1328 if Conversion_OK
(Actual
) then
1329 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1331 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1334 elsif Ekind
(Formal
) = E_Out_Parameter
1335 and then Is_Array_Type
(F_Typ
)
1336 and then Number_Dimensions
(F_Typ
) = 1
1337 and then not Has_Non_Null_Base_Init_Proc
(F_Typ
)
1339 -- Actual is a one-dimensional array or slice, and the type
1340 -- requires no initialization. Create a temporary of the
1341 -- right size, but do not copy actual into it (optimization).
1345 Make_Subtype_Indication
(Loc
,
1346 Subtype_Mark
=> New_Occurrence_Of
(F_Typ
, Loc
),
1348 Make_Index_Or_Discriminant_Constraint
(Loc
,
1349 Constraints
=> New_List
(
1352 Make_Attribute_Reference
(Loc
,
1353 Prefix
=> New_Occurrence_Of
(Var
, Loc
),
1354 Attribute_Name
=> Name_First
),
1356 Make_Attribute_Reference
(Loc
,
1357 Prefix
=> New_Occurrence_Of
(Var
, Loc
),
1358 Attribute_Name
=> Name_Last
)))));
1361 Init
:= New_Occurrence_Of
(Var
, Loc
);
1364 -- An initialization is created for packed conversions as
1365 -- actuals for out parameters to enable Make_Object_Declaration
1366 -- to determine the proper subtype for N_Node. Note that this
1367 -- is wasteful because the extra copying on the call side is
1368 -- not required for such out parameters. ???
1370 elsif Ekind
(Formal
) = E_Out_Parameter
1371 and then Nkind
(Actual
) = N_Type_Conversion
1372 and then (Is_Bit_Packed_Array
(F_Typ
)
1374 Is_Bit_Packed_Array
(Etype
(Expression
(Actual
))))
1376 if Conversion_OK
(Actual
) then
1377 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1379 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1382 elsif Ekind
(Formal
) = E_In_Parameter
then
1384 -- Handle the case in which the actual is a type conversion
1386 if Nkind
(Actual
) = N_Type_Conversion
then
1387 if Conversion_OK
(Actual
) then
1388 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1390 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1393 Init
:= New_Occurrence_Of
(Var
, Loc
);
1401 Make_Object_Declaration
(Loc
,
1402 Defining_Identifier
=> Temp
,
1403 Object_Definition
=> Indic
,
1404 Expression
=> Init
);
1405 Set_Assignment_OK
(N_Node
);
1406 Insert_Action
(N
, N_Node
);
1408 -- Now, normally the deal here is that we use the defining
1409 -- identifier created by that object declaration. There is
1410 -- one exception to this. In the change of representation case
1411 -- the above declaration will end up looking like:
1413 -- temp : type := identifier;
1415 -- And in this case we might as well use the identifier directly
1416 -- and eliminate the temporary. Note that the analysis of the
1417 -- declaration was not a waste of time in that case, since it is
1418 -- what generated the necessary change of representation code. If
1419 -- the change of representation introduced additional code, as in
1420 -- a fixed-integer conversion, the expression is not an identifier
1421 -- and must be kept.
1424 and then Present
(Expression
(N_Node
))
1425 and then Is_Entity_Name
(Expression
(N_Node
))
1427 Temp
:= Entity
(Expression
(N_Node
));
1428 Rewrite
(N_Node
, Make_Null_Statement
(Loc
));
1431 -- For IN parameter, all we do is to replace the actual
1433 if Ekind
(Formal
) = E_In_Parameter
then
1434 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1437 -- Processing for OUT or IN OUT parameter
1440 -- Kill current value indications for the temporary variable we
1441 -- created, since we just passed it as an OUT parameter.
1443 Kill_Current_Values
(Temp
);
1444 Set_Is_Known_Valid
(Temp
, False);
1446 -- If type conversion, use reverse conversion on exit
1448 if Nkind
(Actual
) = N_Type_Conversion
then
1449 if Conversion_OK
(Actual
) then
1450 Expr
:= OK_Convert_To
(V_Typ
, New_Occurrence_Of
(Temp
, Loc
));
1452 Expr
:= Convert_To
(V_Typ
, New_Occurrence_Of
(Temp
, Loc
));
1455 Expr
:= New_Occurrence_Of
(Temp
, Loc
);
1458 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1461 -- If the actual is a conversion of a packed reference, it may
1462 -- already have been expanded by Remove_Side_Effects, and the
1463 -- resulting variable is a temporary which does not designate
1464 -- the proper out-parameter, which may not be addressable. In
1465 -- that case, generate an assignment to the original expression
1466 -- (before expansion of the packed reference) so that the proper
1467 -- expansion of assignment to a packed component can take place.
1474 if Is_Renaming_Of_Object
(Var
)
1475 and then Nkind
(Renamed_Object
(Var
)) = N_Selected_Component
1476 and then Nkind
(Original_Node
(Prefix
(Renamed_Object
(Var
))))
1477 = N_Indexed_Component
1479 Has_Non_Standard_Rep
(Etype
(Prefix
(Renamed_Object
(Var
))))
1481 Obj
:= Renamed_Object
(Var
);
1483 Make_Selected_Component
(Loc
,
1485 New_Copy_Tree
(Original_Node
(Prefix
(Obj
))),
1486 Selector_Name
=> New_Copy
(Selector_Name
(Obj
)));
1487 Reset_Analyzed_Flags
(Lhs
);
1490 Lhs
:= New_Occurrence_Of
(Var
, Loc
);
1493 Set_Assignment_OK
(Lhs
);
1495 if Is_Access_Type
(E_Formal
)
1496 and then Is_Entity_Name
(Lhs
)
1498 Present
(Effective_Extra_Accessibility
(Entity
(Lhs
)))
1500 -- Copyback target is an Ada 2012 stand-alone object of an
1501 -- anonymous access type.
1503 pragma Assert
(Ada_Version
>= Ada_2012
);
1505 if Type_Access_Level
(E_Formal
) >
1506 Object_Access_Level
(Lhs
)
1508 Append_To
(Post_Call
,
1509 Make_Raise_Program_Error
(Loc
,
1510 Reason
=> PE_Accessibility_Check_Failed
));
1513 Append_To
(Post_Call
,
1514 Make_Assignment_Statement
(Loc
,
1516 Expression
=> Expr
));
1518 -- We would like to somehow suppress generation of the
1519 -- extra_accessibility assignment generated by the expansion
1520 -- of the above assignment statement. It's not a correctness
1521 -- issue because the following assignment renders it dead,
1522 -- but generating back-to-back assignments to the same
1523 -- target is undesirable. ???
1525 Append_To
(Post_Call
,
1526 Make_Assignment_Statement
(Loc
,
1527 Name
=> New_Occurrence_Of
(
1528 Effective_Extra_Accessibility
(Entity
(Lhs
)), Loc
),
1529 Expression
=> Make_Integer_Literal
(Loc
,
1530 Type_Access_Level
(E_Formal
))));
1533 Append_To
(Post_Call
,
1534 Make_Assignment_Statement
(Loc
,
1536 Expression
=> Expr
));
1540 end Add_Call_By_Copy_Code
;
1542 ----------------------------------
1543 -- Add_Simple_Call_By_Copy_Code --
1544 ----------------------------------
1546 procedure Add_Simple_Call_By_Copy_Code
is
1548 F_Typ
: Entity_Id
:= Etype
(Formal
);
1557 if not Is_Legal_Copy
then
1561 -- Handle formals whose type comes from the limited view
1563 if From_Limited_With
(F_Typ
)
1564 and then Has_Non_Limited_View
(F_Typ
)
1566 F_Typ
:= Non_Limited_View
(F_Typ
);
1569 -- Use formal type for temp, unless formal type is an unconstrained
1570 -- array, in which case we don't have to worry about bounds checks,
1571 -- and we use the actual type, since that has appropriate bounds.
1573 if Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
) then
1574 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1576 Indic
:= New_Occurrence_Of
(F_Typ
, Loc
);
1579 -- Prepare to generate code
1581 Reset_Packed_Prefix
;
1583 Temp
:= Make_Temporary
(Loc
, 'T', Actual
);
1584 Incod
:= Relocate_Node
(Actual
);
1585 Outcod
:= New_Copy_Tree
(Incod
);
1587 -- Generate declaration of temporary variable, initializing it
1588 -- with the input parameter unless we have an OUT formal or
1589 -- this is an initialization call.
1591 -- If the formal is an out parameter with discriminants, the
1592 -- discriminants must be captured even if the rest of the object
1593 -- is in principle uninitialized, because the discriminants may
1594 -- be read by the called subprogram.
1596 if Ekind
(Formal
) = E_Out_Parameter
then
1599 if Has_Discriminants
(F_Typ
) then
1600 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1603 elsif Inside_Init_Proc
then
1605 -- Could use a comment here to match comment below ???
1607 if Nkind
(Actual
) /= N_Selected_Component
1609 not Has_Discriminant_Dependent_Constraint
1610 (Entity
(Selector_Name
(Actual
)))
1614 -- Otherwise, keep the component in order to generate the proper
1615 -- actual subtype, that depends on enclosing discriminants.
1623 Make_Object_Declaration
(Loc
,
1624 Defining_Identifier
=> Temp
,
1625 Object_Definition
=> Indic
,
1626 Expression
=> Incod
);
1631 -- If the call is to initialize a component of a composite type,
1632 -- and the component does not depend on discriminants, use the
1633 -- actual type of the component. This is required in case the
1634 -- component is constrained, because in general the formal of the
1635 -- initialization procedure will be unconstrained. Note that if
1636 -- the component being initialized is constrained by an enclosing
1637 -- discriminant, the presence of the initialization in the
1638 -- declaration will generate an expression for the actual subtype.
1640 Set_No_Initialization
(Decl
);
1641 Set_Object_Definition
(Decl
,
1642 New_Occurrence_Of
(Etype
(Actual
), Loc
));
1645 Insert_Action
(N
, Decl
);
1647 -- The actual is simply a reference to the temporary
1649 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1651 -- Generate copy out if OUT or IN OUT parameter
1653 if Ekind
(Formal
) /= E_In_Parameter
then
1655 Rhs
:= New_Occurrence_Of
(Temp
, Loc
);
1657 -- Deal with conversion
1659 if Nkind
(Lhs
) = N_Type_Conversion
then
1660 Lhs
:= Expression
(Lhs
);
1661 Rhs
:= Convert_To
(Etype
(Actual
), Rhs
);
1664 Append_To
(Post_Call
,
1665 Make_Assignment_Statement
(Loc
,
1667 Expression
=> Rhs
));
1668 Set_Assignment_OK
(Name
(Last
(Post_Call
)));
1670 end Add_Simple_Call_By_Copy_Code
;
1672 --------------------------------------
1673 -- Add_Validation_Call_By_Copy_Code --
1674 --------------------------------------
1676 procedure Add_Validation_Call_By_Copy_Code
(Act
: Node_Id
) is
1679 Obj_Typ
: Entity_Id
;
1680 Var
: constant Node_Id
:= Unqual_Conv
(Act
);
1684 -- Copy the value of the validation variable back into the object
1687 if Is_Entity_Name
(Var
) then
1688 Var_Id
:= Entity
(Var
);
1689 Obj
:= Validated_Object
(Var_Id
);
1690 Obj_Typ
:= Etype
(Obj
);
1692 Expr
:= New_Occurrence_Of
(Var_Id
, Loc
);
1694 -- A type conversion is needed when the validation variable and
1695 -- the validated object carry different types. This case occurs
1696 -- when the actual is qualified in some fashion.
1699 -- subtype Int is Integer range ...;
1700 -- procedure Call (Val : in out Integer);
1704 -- Call (Integer (Object));
1708 -- Var : Integer := Object; -- conversion to base type
1709 -- if not Var'Valid then -- validity check
1710 -- Call (Var); -- modify Var
1711 -- Object := Int (Var); -- conversion to subtype
1713 if Etype
(Var_Id
) /= Obj_Typ
then
1715 Make_Type_Conversion
(Loc
,
1716 Subtype_Mark
=> New_Occurrence_Of
(Obj_Typ
, Loc
),
1717 Expression
=> Expr
);
1723 -- Object := Object_Type (Var);
1725 Append_To
(Post_Call
,
1726 Make_Assignment_Statement
(Loc
,
1728 Expression
=> Expr
));
1730 -- If the flow reaches this point, then this routine was invoked with
1731 -- an actual which does not denote a validation variable.
1734 pragma Assert
(False);
1737 end Add_Validation_Call_By_Copy_Code
;
1739 ---------------------------
1740 -- Check_Fortran_Logical --
1741 ---------------------------
1743 procedure Check_Fortran_Logical
is
1744 Logical
: constant Entity_Id
:= Etype
(Formal
);
1747 -- Note: this is very incomplete, e.g. it does not handle arrays
1748 -- of logical values. This is really not the right approach at all???)
1751 if Convention
(Subp
) = Convention_Fortran
1752 and then Root_Type
(Etype
(Formal
)) = Standard_Boolean
1753 and then Ekind
(Formal
) /= E_In_Parameter
1755 Var
:= Make_Var
(Actual
);
1756 Append_To
(Post_Call
,
1757 Make_Assignment_Statement
(Loc
,
1758 Name
=> New_Occurrence_Of
(Var
, Loc
),
1760 Unchecked_Convert_To
(
1763 Left_Opnd
=> New_Occurrence_Of
(Var
, Loc
),
1765 Unchecked_Convert_To
(
1767 New_Occurrence_Of
(Standard_False
, Loc
))))));
1769 end Check_Fortran_Logical
;
1775 function Is_Legal_Copy
return Boolean is
1777 -- An attempt to copy a value of such a type can only occur if
1778 -- representation clauses give the actual a misaligned address.
1780 if Is_By_Reference_Type
(Etype
(Formal
)) then
1782 -- The actual may in fact be properly aligned but there is not
1783 -- enough front-end information to determine this. In that case
1784 -- gigi will emit an error if a copy is not legal, or generate
1789 -- For users of Starlet, we assume that the specification of by-
1790 -- reference mechanism is mandatory. This may lead to unaligned
1791 -- objects but at least for DEC legacy code it is known to work.
1792 -- The warning will alert users of this code that a problem may
1795 elsif Mechanism
(Formal
) = By_Reference
1796 and then Is_Valued_Procedure
(Scope
(Formal
))
1799 ("by_reference actual may be misaligned??", Actual
);
1811 function Make_Var
(Actual
: Node_Id
) return Entity_Id
is
1815 if Is_Entity_Name
(Actual
) then
1816 return Entity
(Actual
);
1819 Var
:= Make_Temporary
(Loc
, 'T', Actual
);
1822 Make_Object_Renaming_Declaration
(Loc
,
1823 Defining_Identifier
=> Var
,
1825 New_Occurrence_Of
(Etype
(Actual
), Loc
),
1826 Name
=> Relocate_Node
(Actual
));
1828 Insert_Action
(N
, N_Node
);
1833 -------------------------
1834 -- Reset_Packed_Prefix --
1835 -------------------------
1837 procedure Reset_Packed_Prefix
is
1838 Pfx
: Node_Id
:= Actual
;
1841 Set_Analyzed
(Pfx
, False);
1843 not Nkind_In
(Pfx
, N_Selected_Component
, N_Indexed_Component
);
1844 Pfx
:= Prefix
(Pfx
);
1846 end Reset_Packed_Prefix
;
1848 -- Start of processing for Expand_Actuals
1851 Post_Call
:= New_List
;
1853 Formal
:= First_Formal
(Subp
);
1854 Actual
:= First_Actual
(N
);
1855 while Present
(Formal
) loop
1856 E_Formal
:= Etype
(Formal
);
1857 E_Actual
:= Etype
(Actual
);
1859 -- Handle formals whose type comes from the limited view
1861 if From_Limited_With
(E_Formal
)
1862 and then Has_Non_Limited_View
(E_Formal
)
1864 E_Formal
:= Non_Limited_View
(E_Formal
);
1867 if Is_Scalar_Type
(E_Formal
)
1868 or else Nkind
(Actual
) = N_Slice
1870 Check_Fortran_Logical
;
1874 elsif Ekind
(Formal
) /= E_Out_Parameter
then
1876 -- The unusual case of the current instance of a protected type
1877 -- requires special handling. This can only occur in the context
1878 -- of a call within the body of a protected operation.
1880 if Is_Entity_Name
(Actual
)
1881 and then Ekind
(Entity
(Actual
)) = E_Protected_Type
1882 and then In_Open_Scopes
(Entity
(Actual
))
1884 if Scope
(Subp
) /= Entity
(Actual
) then
1886 ("operation outside protected type may not "
1887 & "call back its protected operations??", Actual
);
1891 Expand_Protected_Object_Reference
(N
, Entity
(Actual
)));
1894 -- Ada 2005 (AI-318-02): If the actual parameter is a call to a
1895 -- build-in-place function, then a temporary return object needs
1896 -- to be created and access to it must be passed to the function.
1897 -- Currently we limit such functions to those with inherently
1898 -- limited result subtypes, but eventually we plan to expand the
1899 -- functions that are treated as build-in-place to include other
1900 -- composite result types.
1902 if Is_Build_In_Place_Function_Call
(Actual
) then
1903 Make_Build_In_Place_Call_In_Anonymous_Context
(Actual
);
1905 -- Ada 2005 (AI-318-02): Specialization of the previous case for
1906 -- actuals containing build-in-place function calls whose returned
1907 -- object covers interface types.
1909 elsif Present
(Unqual_BIP_Iface_Function_Call
(Actual
)) then
1910 Make_Build_In_Place_Iface_Call_In_Anonymous_Context
(Actual
);
1913 Apply_Constraint_Check
(Actual
, E_Formal
);
1915 -- Out parameter case. No constraint checks on access type
1918 elsif Is_Access_Type
(E_Formal
) then
1923 elsif Has_Discriminants
(Base_Type
(E_Formal
))
1924 or else Has_Non_Null_Base_Init_Proc
(E_Formal
)
1926 Apply_Constraint_Check
(Actual
, E_Formal
);
1931 Apply_Constraint_Check
(Actual
, Base_Type
(E_Formal
));
1934 -- Processing for IN-OUT and OUT parameters
1936 if Ekind
(Formal
) /= E_In_Parameter
then
1938 -- For type conversions of arrays, apply length/range checks
1940 if Is_Array_Type
(E_Formal
)
1941 and then Nkind
(Actual
) = N_Type_Conversion
1943 if Is_Constrained
(E_Formal
) then
1944 Apply_Length_Check
(Expression
(Actual
), E_Formal
);
1946 Apply_Range_Check
(Expression
(Actual
), E_Formal
);
1950 -- The actual denotes a variable which captures the value of an
1951 -- object for validation purposes. Add a copy-back to reflect any
1952 -- potential changes in value back into the original object.
1954 -- Var : ... := Object;
1955 -- if not Var'Valid then -- validity check
1956 -- Call (Var); -- modify var
1957 -- Object := Var; -- update Object
1959 -- This case is given higher priority because the subsequent check
1960 -- for type conversion may add an extra copy of the variable and
1961 -- prevent proper value propagation back in the original object.
1963 if Is_Validation_Variable_Reference
(Actual
) then
1964 Add_Validation_Call_By_Copy_Code
(Actual
);
1966 -- If argument is a type conversion for a type that is passed by
1967 -- copy, then we must pass the parameter by copy.
1969 elsif Nkind
(Actual
) = N_Type_Conversion
1971 (Is_Numeric_Type
(E_Formal
)
1972 or else Is_Access_Type
(E_Formal
)
1973 or else Is_Enumeration_Type
(E_Formal
)
1974 or else Is_Bit_Packed_Array
(Etype
(Formal
))
1975 or else Is_Bit_Packed_Array
(Etype
(Expression
(Actual
)))
1977 -- Also pass by copy if change of representation
1979 or else not Same_Representation
1981 Etype
(Expression
(Actual
))))
1983 Add_Call_By_Copy_Code
;
1985 -- References to components of bit-packed arrays are expanded
1986 -- at this point, rather than at the point of analysis of the
1987 -- actuals, to handle the expansion of the assignment to
1988 -- [in] out parameters.
1990 elsif Is_Ref_To_Bit_Packed_Array
(Actual
) then
1991 Add_Simple_Call_By_Copy_Code
;
1993 -- If a non-scalar actual is possibly bit-aligned, we need a copy
1994 -- because the back-end cannot cope with such objects. In other
1995 -- cases where alignment forces a copy, the back-end generates
1996 -- it properly. It should not be generated unconditionally in the
1997 -- front-end because it does not know precisely the alignment
1998 -- requirements of the target, and makes too conservative an
1999 -- estimate, leading to superfluous copies or spurious errors
2000 -- on by-reference parameters.
2002 elsif Nkind
(Actual
) = N_Selected_Component
2004 Component_May_Be_Bit_Aligned
(Entity
(Selector_Name
(Actual
)))
2005 and then not Represented_As_Scalar
(Etype
(Formal
))
2007 Add_Simple_Call_By_Copy_Code
;
2009 -- References to slices of bit-packed arrays are expanded
2011 elsif Is_Ref_To_Bit_Packed_Slice
(Actual
) then
2012 Add_Call_By_Copy_Code
;
2014 -- References to possibly unaligned slices of arrays are expanded
2016 elsif Is_Possibly_Unaligned_Slice
(Actual
) then
2017 Add_Call_By_Copy_Code
;
2019 -- Deal with access types where the actual subtype and the
2020 -- formal subtype are not the same, requiring a check.
2022 -- It is necessary to exclude tagged types because of "downward
2023 -- conversion" errors.
2025 elsif Is_Access_Type
(E_Formal
)
2026 and then not Same_Type
(E_Formal
, E_Actual
)
2027 and then not Is_Tagged_Type
(Designated_Type
(E_Formal
))
2029 Add_Call_By_Copy_Code
;
2031 -- If the actual is not a scalar and is marked for volatile
2032 -- treatment, whereas the formal is not volatile, then pass
2033 -- by copy unless it is a by-reference type.
2035 -- Note: we use Is_Volatile here rather than Treat_As_Volatile,
2036 -- because this is the enforcement of a language rule that applies
2037 -- only to "real" volatile variables, not e.g. to the address
2038 -- clause overlay case.
2040 elsif Is_Entity_Name
(Actual
)
2041 and then Is_Volatile
(Entity
(Actual
))
2042 and then not Is_By_Reference_Type
(E_Actual
)
2043 and then not Is_Scalar_Type
(Etype
(Entity
(Actual
)))
2044 and then not Is_Volatile
(E_Formal
)
2046 Add_Call_By_Copy_Code
;
2048 elsif Nkind
(Actual
) = N_Indexed_Component
2049 and then Is_Entity_Name
(Prefix
(Actual
))
2050 and then Has_Volatile_Components
(Entity
(Prefix
(Actual
)))
2052 Add_Call_By_Copy_Code
;
2054 -- Add call-by-copy code for the case of scalar out parameters
2055 -- when it is not known at compile time that the subtype of the
2056 -- formal is a subrange of the subtype of the actual (or vice
2057 -- versa for in out parameters), in order to get range checks
2058 -- on such actuals. (Maybe this case should be handled earlier
2059 -- in the if statement???)
2061 elsif Is_Scalar_Type
(E_Formal
)
2063 (not In_Subrange_Of
(E_Formal
, E_Actual
)
2065 (Ekind
(Formal
) = E_In_Out_Parameter
2066 and then not In_Subrange_Of
(E_Actual
, E_Formal
)))
2068 -- Perhaps the setting back to False should be done within
2069 -- Add_Call_By_Copy_Code, since it could get set on other
2070 -- cases occurring above???
2072 if Do_Range_Check
(Actual
) then
2073 Set_Do_Range_Check
(Actual
, False);
2076 Add_Call_By_Copy_Code
;
2079 -- RM 3.2.4 (23/3): A predicate is checked on in-out and out
2080 -- by-reference parameters on exit from the call. If the actual
2081 -- is a derived type and the operation is inherited, the body
2082 -- of the operation will not contain a call to the predicate
2083 -- function, so it must be done explicitly after the call. Ditto
2084 -- if the actual is an entity of a predicated subtype.
2086 -- The rule refers to by-reference types, but a check is needed
2087 -- for by-copy types as well. That check is subsumed by the rule
2088 -- for subtype conversion on assignment, but we can generate the
2089 -- required check now.
2091 -- Note also that Subp may be either a subprogram entity for
2092 -- direct calls, or a type entity for indirect calls, which must
2093 -- be handled separately because the name does not denote an
2094 -- overloadable entity.
2096 By_Ref_Predicate_Check
: declare
2097 Aund
: constant Entity_Id
:= Underlying_Type
(E_Actual
);
2100 function Is_Public_Subp
return Boolean;
2101 -- Check whether the subprogram being called is a visible
2102 -- operation of the type of the actual. Used to determine
2103 -- whether an invariant check must be generated on the
2106 ---------------------
2107 -- Is_Public_Subp --
2108 ---------------------
2110 function Is_Public_Subp
return Boolean is
2111 Pack
: constant Entity_Id
:= Scope
(Subp
);
2112 Subp_Decl
: Node_Id
;
2115 if not Is_Subprogram
(Subp
) then
2118 -- The operation may be inherited, or a primitive of the
2122 Nkind_In
(Parent
(Subp
), N_Private_Extension_Declaration
,
2123 N_Full_Type_Declaration
)
2125 Subp_Decl
:= Parent
(Subp
);
2128 Subp_Decl
:= Unit_Declaration_Node
(Subp
);
2131 return Ekind
(Pack
) = E_Package
2133 List_Containing
(Subp_Decl
) =
2134 Visible_Declarations
2135 (Specification
(Unit_Declaration_Node
(Pack
)));
2138 -- Start of processing for By_Ref_Predicate_Check
2147 if Has_Predicates
(Atyp
)
2148 and then Present
(Predicate_Function
(Atyp
))
2150 -- Skip predicate checks for special cases
2152 and then Predicate_Tests_On_Arguments
(Subp
)
2154 Append_To
(Post_Call
,
2155 Make_Predicate_Check
(Atyp
, Actual
));
2158 -- We generated caller-side invariant checks in two cases:
2160 -- a) when calling an inherited operation, where there is an
2161 -- implicit view conversion of the actual to the parent type.
2163 -- b) When the conversion is explicit
2165 -- We treat these cases separately because the required
2166 -- conversion for a) is added later when expanding the call.
2168 if Has_Invariants
(Etype
(Actual
))
2170 Nkind
(Parent
(Subp
)) = N_Private_Extension_Declaration
2172 if Comes_From_Source
(N
) and then Is_Public_Subp
then
2173 Append_To
(Post_Call
, Make_Invariant_Call
(Actual
));
2176 elsif Nkind
(Actual
) = N_Type_Conversion
2177 and then Has_Invariants
(Etype
(Expression
(Actual
)))
2179 if Comes_From_Source
(N
) and then Is_Public_Subp
then
2180 Append_To
(Post_Call
,
2181 Make_Invariant_Call
(Expression
(Actual
)));
2184 end By_Ref_Predicate_Check
;
2186 -- Processing for IN parameters
2189 -- For IN parameters in the bit-packed array case, we expand an
2190 -- indexed component (the circuit in Exp_Ch4 deliberately left
2191 -- indexed components appearing as actuals untouched, so that
2192 -- the special processing above for the OUT and IN OUT cases
2193 -- could be performed. We could make the test in Exp_Ch4 more
2194 -- complex and have it detect the parameter mode, but it is
2195 -- easier simply to handle all cases here.)
2197 if Nkind
(Actual
) = N_Indexed_Component
2198 and then Is_Bit_Packed_Array
(Etype
(Prefix
(Actual
)))
2200 Reset_Packed_Prefix
;
2201 Expand_Packed_Element_Reference
(Actual
);
2203 -- If we have a reference to a bit-packed array, we copy it, since
2204 -- the actual must be byte aligned.
2206 -- Is this really necessary in all cases???
2208 elsif Is_Ref_To_Bit_Packed_Array
(Actual
) then
2209 Add_Simple_Call_By_Copy_Code
;
2211 -- If a non-scalar actual is possibly unaligned, we need a copy
2213 elsif Is_Possibly_Unaligned_Object
(Actual
)
2214 and then not Represented_As_Scalar
(Etype
(Formal
))
2216 Add_Simple_Call_By_Copy_Code
;
2218 -- Similarly, we have to expand slices of packed arrays here
2219 -- because the result must be byte aligned.
2221 elsif Is_Ref_To_Bit_Packed_Slice
(Actual
) then
2222 Add_Call_By_Copy_Code
;
2224 -- Only processing remaining is to pass by copy if this is a
2225 -- reference to a possibly unaligned slice, since the caller
2226 -- expects an appropriately aligned argument.
2228 elsif Is_Possibly_Unaligned_Slice
(Actual
) then
2229 Add_Call_By_Copy_Code
;
2231 -- An unusual case: a current instance of an enclosing task can be
2232 -- an actual, and must be replaced by a reference to self.
2234 elsif Is_Entity_Name
(Actual
)
2235 and then Is_Task_Type
(Entity
(Actual
))
2237 if In_Open_Scopes
(Entity
(Actual
)) then
2239 (Make_Function_Call
(Loc
,
2240 Name
=> New_Occurrence_Of
(RTE
(RE_Self
), Loc
))));
2243 -- A task type cannot otherwise appear as an actual
2246 raise Program_Error
;
2251 Next_Formal
(Formal
);
2252 Next_Actual
(Actual
);
2260 procedure Expand_Call
(N
: Node_Id
) is
2261 Post_Call
: List_Id
;
2264 pragma Assert
(Nkind_In
(N
, N_Entry_Call_Statement
,
2266 N_Procedure_Call_Statement
));
2268 Expand_Call_Helper
(N
, Post_Call
);
2269 Insert_Post_Call_Actions
(N
, Post_Call
);
2272 ------------------------
2273 -- Expand_Call_Helper --
2274 ------------------------
2276 -- This procedure handles expansion of function calls and procedure call
2277 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
2278 -- Expand_N_Procedure_Call_Statement). Processing for calls includes:
2280 -- Replace call to Raise_Exception by Raise_Exception_Always if possible
2281 -- Provide values of actuals for all formals in Extra_Formals list
2282 -- Replace "call" to enumeration literal function by literal itself
2283 -- Rewrite call to predefined operator as operator
2284 -- Replace actuals to in-out parameters that are numeric conversions,
2285 -- with explicit assignment to temporaries before and after the call.
2287 -- Note that the list of actuals has been filled with default expressions
2288 -- during semantic analysis of the call. Only the extra actuals required
2289 -- for the 'Constrained attribute and for accessibility checks are added
2292 procedure Expand_Call_Helper
(N
: Node_Id
; Post_Call
: out List_Id
) is
2293 Loc
: constant Source_Ptr
:= Sloc
(N
);
2294 Call_Node
: Node_Id
:= N
;
2295 Extra_Actuals
: List_Id
:= No_List
;
2296 Prev
: Node_Id
:= Empty
;
2298 procedure Add_Actual_Parameter
(Insert_Param
: Node_Id
);
2299 -- Adds one entry to the end of the actual parameter list. Used for
2300 -- default parameters and for extra actuals (for Extra_Formals). The
2301 -- argument is an N_Parameter_Association node.
2303 procedure Add_Extra_Actual
(Expr
: Node_Id
; EF
: Entity_Id
);
2304 -- Adds an extra actual to the list of extra actuals. Expr is the
2305 -- expression for the value of the actual, EF is the entity for the
2308 procedure Add_View_Conversion_Invariants
2309 (Formal
: Entity_Id
;
2311 -- Adds invariant checks for every intermediate type between the range
2312 -- of a view converted argument to its ancestor (from parent to child).
2314 function Inherited_From_Formal
(S
: Entity_Id
) return Entity_Id
;
2315 -- Within an instance, a type derived from an untagged formal derived
2316 -- type inherits from the original parent, not from the actual. The
2317 -- current derivation mechanism has the derived type inherit from the
2318 -- actual, which is only correct outside of the instance. If the
2319 -- subprogram is inherited, we test for this particular case through a
2320 -- convoluted tree traversal before setting the proper subprogram to be
2323 function In_Unfrozen_Instance
(E
: Entity_Id
) return Boolean;
2324 -- Return true if E comes from an instance that is not yet frozen
2326 function Is_Direct_Deep_Call
(Subp
: Entity_Id
) return Boolean;
2327 -- Determine if Subp denotes a non-dispatching call to a Deep routine
2329 function New_Value
(From
: Node_Id
) return Node_Id
;
2330 -- From is the original Expression. New_Value is equivalent to a call
2331 -- to Duplicate_Subexpr with an explicit dereference when From is an
2332 -- access parameter.
2334 --------------------------
2335 -- Add_Actual_Parameter --
2336 --------------------------
2338 procedure Add_Actual_Parameter
(Insert_Param
: Node_Id
) is
2339 Actual_Expr
: constant Node_Id
:=
2340 Explicit_Actual_Parameter
(Insert_Param
);
2343 -- Case of insertion is first named actual
2345 if No
(Prev
) or else
2346 Nkind
(Parent
(Prev
)) /= N_Parameter_Association
2348 Set_Next_Named_Actual
2349 (Insert_Param
, First_Named_Actual
(Call_Node
));
2350 Set_First_Named_Actual
(Call_Node
, Actual_Expr
);
2353 if No
(Parameter_Associations
(Call_Node
)) then
2354 Set_Parameter_Associations
(Call_Node
, New_List
);
2357 Append
(Insert_Param
, Parameter_Associations
(Call_Node
));
2360 Insert_After
(Prev
, Insert_Param
);
2363 -- Case of insertion is not first named actual
2366 Set_Next_Named_Actual
2367 (Insert_Param
, Next_Named_Actual
(Parent
(Prev
)));
2368 Set_Next_Named_Actual
(Parent
(Prev
), Actual_Expr
);
2369 Append
(Insert_Param
, Parameter_Associations
(Call_Node
));
2372 Prev
:= Actual_Expr
;
2373 end Add_Actual_Parameter
;
2375 ----------------------
2376 -- Add_Extra_Actual --
2377 ----------------------
2379 procedure Add_Extra_Actual
(Expr
: Node_Id
; EF
: Entity_Id
) is
2380 Loc
: constant Source_Ptr
:= Sloc
(Expr
);
2383 if Extra_Actuals
= No_List
then
2384 Extra_Actuals
:= New_List
;
2385 Set_Parent
(Extra_Actuals
, Call_Node
);
2388 Append_To
(Extra_Actuals
,
2389 Make_Parameter_Association
(Loc
,
2390 Selector_Name
=> New_Occurrence_Of
(EF
, Loc
),
2391 Explicit_Actual_Parameter
=> Expr
));
2393 Analyze_And_Resolve
(Expr
, Etype
(EF
));
2395 if Nkind
(Call_Node
) = N_Function_Call
then
2396 Set_Is_Accessibility_Actual
(Parent
(Expr
));
2398 end Add_Extra_Actual
;
2400 ------------------------------------
2401 -- Add_View_Conversion_Invariants --
2402 ------------------------------------
2404 procedure Add_View_Conversion_Invariants
2405 (Formal
: Entity_Id
;
2409 Curr_Typ
: Entity_Id
;
2410 Inv_Checks
: List_Id
;
2411 Par_Typ
: Entity_Id
;
2414 Inv_Checks
:= No_List
;
2416 -- Extract the argument from a potentially nested set of view
2420 while Nkind
(Arg
) = N_Type_Conversion
loop
2421 Arg
:= Expression
(Arg
);
2424 -- Move up the derivation chain starting with the type of the formal
2425 -- parameter down to the type of the actual object.
2428 Par_Typ
:= Etype
(Arg
);
2429 while Par_Typ
/= Etype
(Formal
) and Par_Typ
/= Curr_Typ
loop
2430 Curr_Typ
:= Par_Typ
;
2432 if Has_Invariants
(Curr_Typ
)
2433 and then Present
(Invariant_Procedure
(Curr_Typ
))
2435 -- Verify the invariate of the current type. Generate:
2437 -- <Curr_Typ>Invariant (Curr_Typ (Arg));
2439 Prepend_New_To
(Inv_Checks
,
2440 Make_Procedure_Call_Statement
(Loc
,
2443 (Invariant_Procedure
(Curr_Typ
), Loc
),
2444 Parameter_Associations
=> New_List
(
2445 Make_Type_Conversion
(Loc
,
2446 Subtype_Mark
=> New_Occurrence_Of
(Curr_Typ
, Loc
),
2447 Expression
=> New_Copy_Tree
(Arg
)))));
2450 Par_Typ
:= Base_Type
(Etype
(Curr_Typ
));
2453 if not Is_Empty_List
(Inv_Checks
) then
2454 Insert_Actions_After
(N
, Inv_Checks
);
2456 end Add_View_Conversion_Invariants
;
2458 ---------------------------
2459 -- Inherited_From_Formal --
2460 ---------------------------
2462 function Inherited_From_Formal
(S
: Entity_Id
) return Entity_Id
is
2464 Gen_Par
: Entity_Id
;
2465 Gen_Prim
: Elist_Id
;
2470 -- If the operation is inherited, it is attached to the corresponding
2471 -- type derivation. If the parent in the derivation is a generic
2472 -- actual, it is a subtype of the actual, and we have to recover the
2473 -- original derived type declaration to find the proper parent.
2475 if Nkind
(Parent
(S
)) /= N_Full_Type_Declaration
2476 or else not Is_Derived_Type
(Defining_Identifier
(Parent
(S
)))
2477 or else Nkind
(Type_Definition
(Original_Node
(Parent
(S
)))) /=
2478 N_Derived_Type_Definition
2479 or else not In_Instance
2486 (Type_Definition
(Original_Node
(Parent
(S
))));
2488 if Nkind
(Indic
) = N_Subtype_Indication
then
2489 Par
:= Entity
(Subtype_Mark
(Indic
));
2491 Par
:= Entity
(Indic
);
2495 if not Is_Generic_Actual_Type
(Par
)
2496 or else Is_Tagged_Type
(Par
)
2497 or else Nkind
(Parent
(Par
)) /= N_Subtype_Declaration
2498 or else not In_Open_Scopes
(Scope
(Par
))
2502 Gen_Par
:= Generic_Parent_Type
(Parent
(Par
));
2505 -- If the actual has no generic parent type, the formal is not
2506 -- a formal derived type, so nothing to inherit.
2508 if No
(Gen_Par
) then
2512 -- If the generic parent type is still the generic type, this is a
2513 -- private formal, not a derived formal, and there are no operations
2514 -- inherited from the formal.
2516 if Nkind
(Parent
(Gen_Par
)) = N_Formal_Type_Declaration
then
2520 Gen_Prim
:= Collect_Primitive_Operations
(Gen_Par
);
2522 Elmt
:= First_Elmt
(Gen_Prim
);
2523 while Present
(Elmt
) loop
2524 if Chars
(Node
(Elmt
)) = Chars
(S
) then
2530 F1
:= First_Formal
(S
);
2531 F2
:= First_Formal
(Node
(Elmt
));
2533 and then Present
(F2
)
2535 if Etype
(F1
) = Etype
(F2
)
2536 or else Etype
(F2
) = Gen_Par
2542 exit; -- not the right subprogram
2554 raise Program_Error
;
2555 end Inherited_From_Formal
;
2557 --------------------------
2558 -- In_Unfrozen_Instance --
2559 --------------------------
2561 function In_Unfrozen_Instance
(E
: Entity_Id
) return Boolean is
2566 while Present
(S
) and then S
/= Standard_Standard
loop
2567 if Is_Generic_Instance
(S
)
2568 and then Present
(Freeze_Node
(S
))
2569 and then not Analyzed
(Freeze_Node
(S
))
2578 end In_Unfrozen_Instance
;
2580 -------------------------
2581 -- Is_Direct_Deep_Call --
2582 -------------------------
2584 function Is_Direct_Deep_Call
(Subp
: Entity_Id
) return Boolean is
2586 if Is_TSS
(Subp
, TSS_Deep_Adjust
)
2587 or else Is_TSS
(Subp
, TSS_Deep_Finalize
)
2588 or else Is_TSS
(Subp
, TSS_Deep_Initialize
)
2595 Actual
:= First
(Parameter_Associations
(N
));
2596 Formal
:= First_Formal
(Subp
);
2597 while Present
(Actual
)
2598 and then Present
(Formal
)
2600 if Nkind
(Actual
) = N_Identifier
2601 and then Is_Controlling_Actual
(Actual
)
2602 and then Etype
(Actual
) = Etype
(Formal
)
2608 Next_Formal
(Formal
);
2614 end Is_Direct_Deep_Call
;
2620 function New_Value
(From
: Node_Id
) return Node_Id
is
2621 Res
: constant Node_Id
:= Duplicate_Subexpr
(From
);
2623 if Is_Access_Type
(Etype
(From
)) then
2624 return Make_Explicit_Dereference
(Sloc
(From
), Prefix
=> Res
);
2632 Remote
: constant Boolean := Is_Remote_Call
(Call_Node
);
2635 Orig_Subp
: Entity_Id
:= Empty
;
2636 Param_Count
: Natural := 0;
2637 Parent_Formal
: Entity_Id
;
2638 Parent_Subp
: Entity_Id
;
2639 Pref_Entity
: Entity_Id
;
2643 Prev_Orig
: Node_Id
;
2644 -- Original node for an actual, which may have been rewritten. If the
2645 -- actual is a function call that has been transformed from a selected
2646 -- component, the original node is unanalyzed. Otherwise, it carries
2647 -- semantic information used to generate additional actuals.
2649 CW_Interface_Formals_Present
: Boolean := False;
2651 -- Start of processing for Expand_Call_Helper
2654 Post_Call
:= New_List
;
2656 -- Expand the function or procedure call if the first actual has a
2657 -- declared dimension aspect, and the subprogram is declared in one
2658 -- of the dimension I/O packages.
2660 if Ada_Version
>= Ada_2012
2662 Nkind_In
(Call_Node
, N_Procedure_Call_Statement
, N_Function_Call
)
2663 and then Present
(Parameter_Associations
(Call_Node
))
2665 Expand_Put_Call_With_Symbol
(Call_Node
);
2668 -- Ignore if previous error
2670 if Nkind
(Call_Node
) in N_Has_Etype
2671 and then Etype
(Call_Node
) = Any_Type
2676 -- Call using access to subprogram with explicit dereference
2678 if Nkind
(Name
(Call_Node
)) = N_Explicit_Dereference
then
2679 Subp
:= Etype
(Name
(Call_Node
));
2680 Parent_Subp
:= Empty
;
2682 -- Case of call to simple entry, where the Name is a selected component
2683 -- whose prefix is the task, and whose selector name is the entry name
2685 elsif Nkind
(Name
(Call_Node
)) = N_Selected_Component
then
2686 Subp
:= Entity
(Selector_Name
(Name
(Call_Node
)));
2687 Parent_Subp
:= Empty
;
2689 -- Case of call to member of entry family, where Name is an indexed
2690 -- component, with the prefix being a selected component giving the
2691 -- task and entry family name, and the index being the entry index.
2693 elsif Nkind
(Name
(Call_Node
)) = N_Indexed_Component
then
2694 Subp
:= Entity
(Selector_Name
(Prefix
(Name
(Call_Node
))));
2695 Parent_Subp
:= Empty
;
2700 Subp
:= Entity
(Name
(Call_Node
));
2701 Parent_Subp
:= Alias
(Subp
);
2703 -- Replace call to Raise_Exception by call to Raise_Exception_Always
2704 -- if we can tell that the first parameter cannot possibly be null.
2705 -- This improves efficiency by avoiding a run-time test.
2707 -- We do not do this if Raise_Exception_Always does not exist, which
2708 -- can happen in configurable run time profiles which provide only a
2711 if Is_RTE
(Subp
, RE_Raise_Exception
)
2712 and then RTE_Available
(RE_Raise_Exception_Always
)
2715 FA
: constant Node_Id
:=
2716 Original_Node
(First_Actual
(Call_Node
));
2719 -- The case we catch is where the first argument is obtained
2720 -- using the Identity attribute (which must always be
2723 if Nkind
(FA
) = N_Attribute_Reference
2724 and then Attribute_Name
(FA
) = Name_Identity
2726 Subp
:= RTE
(RE_Raise_Exception_Always
);
2727 Set_Name
(Call_Node
, New_Occurrence_Of
(Subp
, Loc
));
2732 if Ekind
(Subp
) = E_Entry
then
2733 Parent_Subp
:= Empty
;
2737 -- Ada 2005 (AI-345): We have a procedure call as a triggering
2738 -- alternative in an asynchronous select or as an entry call in
2739 -- a conditional or timed select. Check whether the procedure call
2740 -- is a renaming of an entry and rewrite it as an entry call.
2742 if Ada_Version
>= Ada_2005
2743 and then Nkind
(Call_Node
) = N_Procedure_Call_Statement
2745 ((Nkind
(Parent
(Call_Node
)) = N_Triggering_Alternative
2746 and then Triggering_Statement
(Parent
(Call_Node
)) = Call_Node
)
2748 (Nkind
(Parent
(Call_Node
)) = N_Entry_Call_Alternative
2749 and then Entry_Call_Statement
(Parent
(Call_Node
)) = Call_Node
))
2753 Ren_Root
: Entity_Id
:= Subp
;
2756 -- This may be a chain of renamings, find the root
2758 if Present
(Alias
(Ren_Root
)) then
2759 Ren_Root
:= Alias
(Ren_Root
);
2762 if Present
(Original_Node
(Parent
(Parent
(Ren_Root
)))) then
2763 Ren_Decl
:= Original_Node
(Parent
(Parent
(Ren_Root
)));
2765 if Nkind
(Ren_Decl
) = N_Subprogram_Renaming_Declaration
then
2767 Make_Entry_Call_Statement
(Loc
,
2769 New_Copy_Tree
(Name
(Ren_Decl
)),
2770 Parameter_Associations
=>
2772 (Parameter_Associations
(Call_Node
))));
2780 if Modify_Tree_For_C
2781 and then Nkind
(Call_Node
) = N_Function_Call
2782 and then Is_Entity_Name
(Name
(Call_Node
))
2785 Func_Id
: constant Entity_Id
:=
2786 Ultimate_Alias
(Entity
(Name
(Call_Node
)));
2788 -- When generating C code, transform a function call that returns
2789 -- a constrained array type into procedure form.
2791 if Rewritten_For_C
(Func_Id
) then
2793 -- For internally generated calls ensure that they reference
2794 -- the entity of the spec of the called function (needed since
2795 -- the expander may generate calls using the entity of their
2796 -- body). See for example Expand_Boolean_Operator().
2798 if not (Comes_From_Source
(Call_Node
))
2799 and then Nkind
(Unit_Declaration_Node
(Func_Id
)) =
2802 Set_Entity
(Name
(Call_Node
),
2803 Corresponding_Function
2804 (Corresponding_Procedure
(Func_Id
)));
2807 Rewrite_Function_Call_For_C
(Call_Node
);
2810 -- Also introduce a temporary for functions that return a record
2811 -- called within another procedure or function call, since records
2812 -- are passed by pointer in the generated C code, and we cannot
2813 -- take a pointer from a subprogram call.
2815 elsif Nkind
(Parent
(Call_Node
)) in N_Subprogram_Call
2816 and then Is_Record_Type
(Etype
(Func_Id
))
2819 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
2824 -- Temp : ... := Func_Call (...);
2827 Make_Object_Declaration
(Loc
,
2828 Defining_Identifier
=> Temp_Id
,
2829 Object_Definition
=>
2830 New_Occurrence_Of
(Etype
(Func_Id
), Loc
),
2832 Make_Function_Call
(Loc
,
2834 New_Occurrence_Of
(Func_Id
, Loc
),
2835 Parameter_Associations
=>
2836 Parameter_Associations
(Call_Node
)));
2838 Insert_Action
(Parent
(Call_Node
), Decl
);
2839 Rewrite
(Call_Node
, New_Occurrence_Of
(Temp_Id
, Loc
));
2846 -- First step, compute extra actuals, corresponding to any Extra_Formals
2847 -- present. Note that we do not access Extra_Formals directly, instead
2848 -- we simply note the presence of the extra formals as we process the
2849 -- regular formals collecting corresponding actuals in Extra_Actuals.
2851 -- We also generate any required range checks for actuals for in formals
2852 -- as we go through the loop, since this is a convenient place to do it.
2853 -- (Though it seems that this would be better done in Expand_Actuals???)
2855 -- Special case: Thunks must not compute the extra actuals; they must
2856 -- just propagate to the target primitive their extra actuals.
2858 if Is_Thunk
(Current_Scope
)
2859 and then Thunk_Entity
(Current_Scope
) = Subp
2860 and then Present
(Extra_Formals
(Subp
))
2862 pragma Assert
(Present
(Extra_Formals
(Current_Scope
)));
2865 Target_Formal
: Entity_Id
;
2866 Thunk_Formal
: Entity_Id
;
2869 Target_Formal
:= Extra_Formals
(Subp
);
2870 Thunk_Formal
:= Extra_Formals
(Current_Scope
);
2871 while Present
(Target_Formal
) loop
2873 (Expr
=> New_Occurrence_Of
(Thunk_Formal
, Loc
),
2874 EF
=> Thunk_Formal
);
2876 Target_Formal
:= Extra_Formal
(Target_Formal
);
2877 Thunk_Formal
:= Extra_Formal
(Thunk_Formal
);
2880 while Is_Non_Empty_List
(Extra_Actuals
) loop
2881 Add_Actual_Parameter
(Remove_Head
(Extra_Actuals
));
2884 Expand_Actuals
(Call_Node
, Subp
, Post_Call
);
2885 pragma Assert
(Is_Empty_List
(Post_Call
));
2890 Formal
:= First_Formal
(Subp
);
2891 Actual
:= First_Actual
(Call_Node
);
2893 while Present
(Formal
) loop
2895 -- Generate range check if required
2897 if Do_Range_Check
(Actual
)
2898 and then Ekind
(Formal
) = E_In_Parameter
2900 Generate_Range_Check
2901 (Actual
, Etype
(Formal
), CE_Range_Check_Failed
);
2904 -- Prepare to examine current entry
2907 Prev_Orig
:= Original_Node
(Prev
);
2909 -- Ada 2005 (AI-251): Check if any formal is a class-wide interface
2910 -- to expand it in a further round.
2912 CW_Interface_Formals_Present
:=
2913 CW_Interface_Formals_Present
2915 (Is_Class_Wide_Type
(Etype
(Formal
))
2916 and then Is_Interface
(Etype
(Etype
(Formal
))))
2918 (Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
2919 and then Is_Class_Wide_Type
(Directly_Designated_Type
2920 (Etype
(Etype
(Formal
))))
2921 and then Is_Interface
(Directly_Designated_Type
2922 (Etype
(Etype
(Formal
)))));
2924 -- Create possible extra actual for constrained case. Usually, the
2925 -- extra actual is of the form actual'constrained, but since this
2926 -- attribute is only available for unconstrained records, TRUE is
2927 -- expanded if the type of the formal happens to be constrained (for
2928 -- instance when this procedure is inherited from an unconstrained
2929 -- record to a constrained one) or if the actual has no discriminant
2930 -- (its type is constrained). An exception to this is the case of a
2931 -- private type without discriminants. In this case we pass FALSE
2932 -- because the object has underlying discriminants with defaults.
2934 if Present
(Extra_Constrained
(Formal
)) then
2935 if Ekind
(Etype
(Prev
)) in Private_Kind
2936 and then not Has_Discriminants
(Base_Type
(Etype
(Prev
)))
2939 (Expr
=> New_Occurrence_Of
(Standard_False
, Loc
),
2940 EF
=> Extra_Constrained
(Formal
));
2942 elsif Is_Constrained
(Etype
(Formal
))
2943 or else not Has_Discriminants
(Etype
(Prev
))
2946 (Expr
=> New_Occurrence_Of
(Standard_True
, Loc
),
2947 EF
=> Extra_Constrained
(Formal
));
2949 -- Do not produce extra actuals for Unchecked_Union parameters.
2950 -- Jump directly to the end of the loop.
2952 elsif Is_Unchecked_Union
(Base_Type
(Etype
(Actual
))) then
2953 goto Skip_Extra_Actual_Generation
;
2956 -- If the actual is a type conversion, then the constrained
2957 -- test applies to the actual, not the target type.
2963 -- Test for unchecked conversions as well, which can occur
2964 -- as out parameter actuals on calls to stream procedures.
2967 while Nkind_In
(Act_Prev
, N_Type_Conversion
,
2968 N_Unchecked_Type_Conversion
)
2970 Act_Prev
:= Expression
(Act_Prev
);
2973 -- If the expression is a conversion of a dereference, this
2974 -- is internally generated code that manipulates addresses,
2975 -- e.g. when building interface tables. No check should
2976 -- occur in this case, and the discriminated object is not
2979 if not Comes_From_Source
(Actual
)
2980 and then Nkind
(Actual
) = N_Unchecked_Type_Conversion
2981 and then Nkind
(Act_Prev
) = N_Explicit_Dereference
2984 (Expr
=> New_Occurrence_Of
(Standard_False
, Loc
),
2985 EF
=> Extra_Constrained
(Formal
));
2990 Make_Attribute_Reference
(Sloc
(Prev
),
2992 Duplicate_Subexpr_No_Checks
2993 (Act_Prev
, Name_Req
=> True),
2994 Attribute_Name
=> Name_Constrained
),
2995 EF
=> Extra_Constrained
(Formal
));
3001 -- Create possible extra actual for accessibility level
3003 if Present
(Extra_Accessibility
(Formal
)) then
3005 -- Ada 2005 (AI-252): If the actual was rewritten as an Access
3006 -- attribute, then the original actual may be an aliased object
3007 -- occurring as the prefix in a call using "Object.Operation"
3008 -- notation. In that case we must pass the level of the object,
3009 -- so Prev_Orig is reset to Prev and the attribute will be
3010 -- processed by the code for Access attributes further below.
3012 if Prev_Orig
/= Prev
3013 and then Nkind
(Prev
) = N_Attribute_Reference
3014 and then Get_Attribute_Id
(Attribute_Name
(Prev
)) =
3016 and then Is_Aliased_View
(Prev_Orig
)
3020 -- A class-wide precondition generates a test in which formals of
3021 -- the subprogram are replaced by actuals that came from source.
3022 -- In that case as well, the accessiblity comes from the actual.
3023 -- This is the one case in which there are references to formals
3024 -- outside of their subprogram.
3026 elsif Prev_Orig
/= Prev
3027 and then Is_Entity_Name
(Prev_Orig
)
3028 and then Present
(Entity
(Prev_Orig
))
3029 and then Is_Formal
(Entity
(Prev_Orig
))
3030 and then not In_Open_Scopes
(Scope
(Entity
(Prev_Orig
)))
3034 -- If the actual is a formal of an enclosing subprogram it is
3035 -- the right entity, even if it is a rewriting. This happens
3036 -- when the call is within an inherited condition or predicate.
3038 elsif Is_Entity_Name
(Actual
)
3039 and then Is_Formal
(Entity
(Actual
))
3040 and then In_Open_Scopes
(Scope
(Entity
(Actual
)))
3044 elsif Nkind
(Prev_Orig
) = N_Type_Conversion
then
3045 Prev_Orig
:= Expression
(Prev_Orig
);
3048 -- Ada 2005 (AI-251): Thunks must propagate the extra actuals of
3049 -- accessibility levels.
3051 if Is_Thunk
(Current_Scope
) then
3053 Parm_Ent
: Entity_Id
;
3056 if Is_Controlling_Actual
(Actual
) then
3058 -- Find the corresponding actual of the thunk
3060 Parm_Ent
:= First_Entity
(Current_Scope
);
3061 for J
in 2 .. Param_Count
loop
3062 Next_Entity
(Parm_Ent
);
3065 -- Handle unchecked conversion of access types generated
3066 -- in thunks (cf. Expand_Interface_Thunk).
3068 elsif Is_Access_Type
(Etype
(Actual
))
3069 and then Nkind
(Actual
) = N_Unchecked_Type_Conversion
3071 Parm_Ent
:= Entity
(Expression
(Actual
));
3073 else pragma Assert
(Is_Entity_Name
(Actual
));
3074 Parm_Ent
:= Entity
(Actual
);
3079 New_Occurrence_Of
(Extra_Accessibility
(Parm_Ent
), Loc
),
3080 EF
=> Extra_Accessibility
(Formal
));
3083 elsif Is_Entity_Name
(Prev_Orig
) then
3085 -- When passing an access parameter, or a renaming of an access
3086 -- parameter, as the actual to another access parameter we need
3087 -- to pass along the actual's own access level parameter. This
3088 -- is done if we are within the scope of the formal access
3089 -- parameter (if this is an inlined body the extra formal is
3092 if (Is_Formal
(Entity
(Prev_Orig
))
3094 (Present
(Renamed_Object
(Entity
(Prev_Orig
)))
3096 Is_Entity_Name
(Renamed_Object
(Entity
(Prev_Orig
)))
3099 (Entity
(Renamed_Object
(Entity
(Prev_Orig
))))))
3100 and then Ekind
(Etype
(Prev_Orig
)) = E_Anonymous_Access_Type
3101 and then In_Open_Scopes
(Scope
(Entity
(Prev_Orig
)))
3104 Parm_Ent
: constant Entity_Id
:= Param_Entity
(Prev_Orig
);
3107 pragma Assert
(Present
(Parm_Ent
));
3109 if Present
(Extra_Accessibility
(Parm_Ent
)) then
3113 (Extra_Accessibility
(Parm_Ent
), Loc
),
3114 EF
=> Extra_Accessibility
(Formal
));
3116 -- If the actual access parameter does not have an
3117 -- associated extra formal providing its scope level,
3118 -- then treat the actual as having library-level
3124 Make_Integer_Literal
(Loc
,
3125 Intval
=> Scope_Depth
(Standard_Standard
)),
3126 EF
=> Extra_Accessibility
(Formal
));
3130 -- The actual is a normal access value, so just pass the level
3131 -- of the actual's access type.
3135 (Expr
=> Dynamic_Accessibility_Level
(Prev_Orig
),
3136 EF
=> Extra_Accessibility
(Formal
));
3139 -- If the actual is an access discriminant, then pass the level
3140 -- of the enclosing object (RM05-3.10.2(12.4/2)).
3142 elsif Nkind
(Prev_Orig
) = N_Selected_Component
3143 and then Ekind
(Entity
(Selector_Name
(Prev_Orig
))) =
3145 and then Ekind
(Etype
(Entity
(Selector_Name
(Prev_Orig
)))) =
3146 E_Anonymous_Access_Type
3150 Make_Integer_Literal
(Loc
,
3151 Intval
=> Object_Access_Level
(Prefix
(Prev_Orig
))),
3152 EF
=> Extra_Accessibility
(Formal
));
3157 case Nkind
(Prev_Orig
) is
3158 when N_Attribute_Reference
=>
3159 case Get_Attribute_Id
(Attribute_Name
(Prev_Orig
)) is
3161 -- For X'Access, pass on the level of the prefix X
3163 when Attribute_Access
=>
3165 -- Accessibility level of S'Access is that of A
3167 Prev_Orig
:= Prefix
(Prev_Orig
);
3169 -- If the expression is a view conversion, the
3170 -- accessibility level is that of the expression.
3172 if Nkind
(Original_Node
(Prev_Orig
)) =
3175 Nkind
(Expression
(Original_Node
(Prev_Orig
))) =
3176 N_Explicit_Dereference
3179 Expression
(Original_Node
(Prev_Orig
));
3182 -- If this is an Access attribute applied to the
3183 -- the current instance object passed to a type
3184 -- initialization procedure, then use the level
3185 -- of the type itself. This is not really correct,
3186 -- as there should be an extra level parameter
3187 -- passed in with _init formals (only in the case
3188 -- where the type is immutably limited), but we
3189 -- don't have an easy way currently to create such
3190 -- an extra formal (init procs aren't ever frozen).
3191 -- For now we just use the level of the type,
3192 -- which may be too shallow, but that works better
3193 -- than passing Object_Access_Level of the type,
3194 -- which can be one level too deep in some cases.
3197 -- A further case that requires special handling
3198 -- is the common idiom E.all'access. If E is a
3199 -- formal of the enclosing subprogram, the
3200 -- accessibility of the expression is that of E.
3202 if Is_Entity_Name
(Prev_Orig
) then
3203 Pref_Entity
:= Entity
(Prev_Orig
);
3205 elsif Nkind
(Prev_Orig
) = N_Explicit_Dereference
3206 and then Is_Entity_Name
(Prefix
(Prev_Orig
))
3208 Pref_Entity
:= Entity
(Prefix
((Prev_Orig
)));
3211 Pref_Entity
:= Empty
;
3214 if Is_Entity_Name
(Prev_Orig
)
3215 and then Is_Type
(Entity
(Prev_Orig
))
3219 Make_Integer_Literal
(Loc
,
3221 Type_Access_Level
(Pref_Entity
)),
3222 EF
=> Extra_Accessibility
(Formal
));
3224 elsif Nkind
(Prev_Orig
) = N_Explicit_Dereference
3225 and then Present
(Pref_Entity
)
3226 and then Is_Formal
(Pref_Entity
)
3228 (Extra_Accessibility
(Pref_Entity
))
3233 (Extra_Accessibility
(Pref_Entity
), Loc
),
3234 EF
=> Extra_Accessibility
(Formal
));
3239 Make_Integer_Literal
(Loc
,
3241 Object_Access_Level
(Prev_Orig
)),
3242 EF
=> Extra_Accessibility
(Formal
));
3245 -- Treat the unchecked attributes as library-level
3247 when Attribute_Unchecked_Access
3248 | Attribute_Unrestricted_Access
3252 Make_Integer_Literal
(Loc
,
3253 Intval
=> Scope_Depth
(Standard_Standard
)),
3254 EF
=> Extra_Accessibility
(Formal
));
3256 -- No other cases of attributes returning access
3257 -- values that can be passed to access parameters.
3260 raise Program_Error
;
3264 -- For allocators we pass the level of the execution of the
3265 -- called subprogram, which is one greater than the current
3271 Make_Integer_Literal
(Loc
,
3272 Intval
=> Scope_Depth
(Current_Scope
) + 1),
3273 EF
=> Extra_Accessibility
(Formal
));
3275 -- For most other cases we simply pass the level of the
3276 -- actual's access type. The type is retrieved from
3277 -- Prev rather than Prev_Orig, because in some cases
3278 -- Prev_Orig denotes an original expression that has
3279 -- not been analyzed.
3283 (Expr
=> Dynamic_Accessibility_Level
(Prev
),
3284 EF
=> Extra_Accessibility
(Formal
));
3289 -- Perform the check of 4.6(49) that prevents a null value from being
3290 -- passed as an actual to an access parameter. Note that the check
3291 -- is elided in the common cases of passing an access attribute or
3292 -- access parameter as an actual. Also, we currently don't enforce
3293 -- this check for expander-generated actuals and when -gnatdj is set.
3295 if Ada_Version
>= Ada_2005
then
3297 -- Ada 2005 (AI-231): Check null-excluding access types. Note that
3298 -- the intent of 6.4.1(13) is that null-exclusion checks should
3299 -- not be done for 'out' parameters, even though it refers only
3300 -- to constraint checks, and a null_exclusion is not a constraint.
3301 -- Note that AI05-0196-1 corrects this mistake in the RM.
3303 if Is_Access_Type
(Etype
(Formal
))
3304 and then Can_Never_Be_Null
(Etype
(Formal
))
3305 and then Ekind
(Formal
) /= E_Out_Parameter
3306 and then Nkind
(Prev
) /= N_Raise_Constraint_Error
3307 and then (Known_Null
(Prev
)
3308 or else not Can_Never_Be_Null
(Etype
(Prev
)))
3310 Install_Null_Excluding_Check
(Prev
);
3313 -- Ada_Version < Ada_2005
3316 if Ekind
(Etype
(Formal
)) /= E_Anonymous_Access_Type
3317 or else Access_Checks_Suppressed
(Subp
)
3321 elsif Debug_Flag_J
then
3324 elsif not Comes_From_Source
(Prev
) then
3327 elsif Is_Entity_Name
(Prev
)
3328 and then Ekind
(Etype
(Prev
)) = E_Anonymous_Access_Type
3332 elsif Nkind_In
(Prev
, N_Allocator
, N_Attribute_Reference
) then
3336 Install_Null_Excluding_Check
(Prev
);
3340 -- Perform appropriate validity checks on parameters that
3343 if Validity_Checks_On
then
3344 if (Ekind
(Formal
) = E_In_Parameter
3345 and then Validity_Check_In_Params
)
3347 (Ekind
(Formal
) = E_In_Out_Parameter
3348 and then Validity_Check_In_Out_Params
)
3350 -- If the actual is an indexed component of a packed type (or
3351 -- is an indexed or selected component whose prefix recursively
3352 -- meets this condition), it has not been expanded yet. It will
3353 -- be copied in the validity code that follows, and has to be
3354 -- expanded appropriately, so reanalyze it.
3356 -- What we do is just to unset analyzed bits on prefixes till
3357 -- we reach something that does not have a prefix.
3364 while Nkind_In
(Nod
, N_Indexed_Component
,
3365 N_Selected_Component
)
3367 Set_Analyzed
(Nod
, False);
3368 Nod
:= Prefix
(Nod
);
3372 Ensure_Valid
(Actual
);
3376 -- For IN OUT and OUT parameters, ensure that subscripts are valid
3377 -- since this is a left side reference. We only do this for calls
3378 -- from the source program since we assume that compiler generated
3379 -- calls explicitly generate any required checks. We also need it
3380 -- only if we are doing standard validity checks, since clearly it is
3381 -- not needed if validity checks are off, and in subscript validity
3382 -- checking mode, all indexed components are checked with a call
3383 -- directly from Expand_N_Indexed_Component.
3385 if Comes_From_Source
(Call_Node
)
3386 and then Ekind
(Formal
) /= E_In_Parameter
3387 and then Validity_Checks_On
3388 and then Validity_Check_Default
3389 and then not Validity_Check_Subscripts
3391 Check_Valid_Lvalue_Subscripts
(Actual
);
3394 -- Mark any scalar OUT parameter that is a simple variable as no
3395 -- longer known to be valid (unless the type is always valid). This
3396 -- reflects the fact that if an OUT parameter is never set in a
3397 -- procedure, then it can become invalid on the procedure return.
3399 if Ekind
(Formal
) = E_Out_Parameter
3400 and then Is_Entity_Name
(Actual
)
3401 and then Ekind
(Entity
(Actual
)) = E_Variable
3402 and then not Is_Known_Valid
(Etype
(Actual
))
3404 Set_Is_Known_Valid
(Entity
(Actual
), False);
3407 -- For an OUT or IN OUT parameter, if the actual is an entity, then
3408 -- clear current values, since they can be clobbered. We are probably
3409 -- doing this in more places than we need to, but better safe than
3410 -- sorry when it comes to retaining bad current values.
3412 if Ekind
(Formal
) /= E_In_Parameter
3413 and then Is_Entity_Name
(Actual
)
3414 and then Present
(Entity
(Actual
))
3417 Ent
: constant Entity_Id
:= Entity
(Actual
);
3421 -- For an OUT or IN OUT parameter that is an assignable entity,
3422 -- we do not want to clobber the Last_Assignment field, since
3423 -- if it is set, it was precisely because it is indeed an OUT
3424 -- or IN OUT parameter. We do reset the Is_Known_Valid flag
3425 -- since the subprogram could have returned in invalid value.
3427 if Ekind_In
(Formal
, E_Out_Parameter
, E_In_Out_Parameter
)
3428 and then Is_Assignable
(Ent
)
3430 Sav
:= Last_Assignment
(Ent
);
3431 Kill_Current_Values
(Ent
);
3432 Set_Last_Assignment
(Ent
, Sav
);
3433 Set_Is_Known_Valid
(Ent
, False);
3435 -- For all other cases, just kill the current values
3438 Kill_Current_Values
(Ent
);
3443 -- If the formal is class wide and the actual is an aggregate, force
3444 -- evaluation so that the back end who does not know about class-wide
3445 -- type, does not generate a temporary of the wrong size.
3447 if not Is_Class_Wide_Type
(Etype
(Formal
)) then
3450 elsif Nkind
(Actual
) = N_Aggregate
3451 or else (Nkind
(Actual
) = N_Qualified_Expression
3452 and then Nkind
(Expression
(Actual
)) = N_Aggregate
)
3454 Force_Evaluation
(Actual
);
3457 -- In a remote call, if the formal is of a class-wide type, check
3458 -- that the actual meets the requirements described in E.4(18).
3460 if Remote
and then Is_Class_Wide_Type
(Etype
(Formal
)) then
3461 Insert_Action
(Actual
,
3462 Make_Transportable_Check
(Loc
,
3463 Duplicate_Subexpr_Move_Checks
(Actual
)));
3466 -- Perform invariant checks for all intermediate types in a view
3467 -- conversion after successful return from a call that passes the
3468 -- view conversion as an IN OUT or OUT parameter (RM 7.3.2 (12/3,
3469 -- 13/3, 14/3)). Consider only source conversion in order to avoid
3470 -- generating spurious checks on complex expansion such as object
3471 -- initialization through an extension aggregate.
3473 if Comes_From_Source
(N
)
3474 and then Ekind
(Formal
) /= E_In_Parameter
3475 and then Nkind
(Actual
) = N_Type_Conversion
3477 Add_View_Conversion_Invariants
(Formal
, Actual
);
3480 -- Generating C the initialization of an allocator is performed by
3481 -- means of individual statements, and hence it must be done before
3484 if Modify_Tree_For_C
3485 and then Nkind
(Actual
) = N_Allocator
3486 and then Nkind
(Expression
(Actual
)) = N_Qualified_Expression
3488 Remove_Side_Effects
(Actual
);
3491 -- This label is required when skipping extra actual generation for
3492 -- Unchecked_Union parameters.
3494 <<Skip_Extra_Actual_Generation
>>
3496 Param_Count
:= Param_Count
+ 1;
3497 Next_Actual
(Actual
);
3498 Next_Formal
(Formal
);
3501 -- If we are calling an Ada 2012 function which needs to have the
3502 -- "accessibility level determined by the point of call" (AI05-0234)
3503 -- passed in to it, then pass it in.
3505 if Ekind_In
(Subp
, E_Function
, E_Operator
, E_Subprogram_Type
)
3507 Present
(Extra_Accessibility_Of_Result
(Ultimate_Alias
(Subp
)))
3510 Ancestor
: Node_Id
:= Parent
(Call_Node
);
3511 Level
: Node_Id
:= Empty
;
3512 Defer
: Boolean := False;
3515 -- Unimplemented: if Subp returns an anonymous access type, then
3517 -- a) if the call is the operand of an explict conversion, then
3518 -- the target type of the conversion (a named access type)
3519 -- determines the accessibility level pass in;
3521 -- b) if the call defines an access discriminant of an object
3522 -- (e.g., the discriminant of an object being created by an
3523 -- allocator, or the discriminant of a function result),
3524 -- then the accessibility level to pass in is that of the
3525 -- discriminated object being initialized).
3529 while Nkind
(Ancestor
) = N_Qualified_Expression
3531 Ancestor
:= Parent
(Ancestor
);
3534 case Nkind
(Ancestor
) is
3537 -- At this point, we'd like to assign
3539 -- Level := Dynamic_Accessibility_Level (Ancestor);
3541 -- but Etype of Ancestor may not have been set yet,
3542 -- so that doesn't work.
3544 -- Handle this later in Expand_Allocator_Expression.
3548 when N_Object_Declaration
3549 | N_Object_Renaming_Declaration
3552 Def_Id
: constant Entity_Id
:=
3553 Defining_Identifier
(Ancestor
);
3556 if Is_Return_Object
(Def_Id
) then
3557 if Present
(Extra_Accessibility_Of_Result
3558 (Return_Applies_To
(Scope
(Def_Id
))))
3560 -- Pass along value that was passed in if the
3561 -- routine we are returning from also has an
3562 -- Accessibility_Of_Result formal.
3566 (Extra_Accessibility_Of_Result
3567 (Return_Applies_To
(Scope
(Def_Id
))), Loc
);
3571 Make_Integer_Literal
(Loc
,
3572 Intval
=> Object_Access_Level
(Def_Id
));
3576 when N_Simple_Return_Statement
=>
3577 if Present
(Extra_Accessibility_Of_Result
3579 (Return_Statement_Entity
(Ancestor
))))
3581 -- Pass along value that was passed in if the returned
3582 -- routine also has an Accessibility_Of_Result formal.
3586 (Extra_Accessibility_Of_Result
3588 (Return_Statement_Entity
(Ancestor
))), Loc
);
3596 if not Present
(Level
) then
3598 -- The "innermost master that evaluates the function call".
3600 -- ??? - Should we use Integer'Last here instead in order
3601 -- to deal with (some of) the problems associated with
3602 -- calls to subps whose enclosing scope is unknown (e.g.,
3603 -- Anon_Access_To_Subp_Param.all)?
3606 Make_Integer_Literal
(Loc
,
3607 Intval
=> Scope_Depth
(Current_Scope
) + 1);
3613 Extra_Accessibility_Of_Result
(Ultimate_Alias
(Subp
)));
3618 -- If we are expanding the RHS of an assignment we need to check if tag
3619 -- propagation is needed. You might expect this processing to be in
3620 -- Analyze_Assignment but has to be done earlier (bottom-up) because the
3621 -- assignment might be transformed to a declaration for an unconstrained
3622 -- value if the expression is classwide.
3624 if Nkind
(Call_Node
) = N_Function_Call
3625 and then Is_Tag_Indeterminate
(Call_Node
)
3626 and then Is_Entity_Name
(Name
(Call_Node
))
3629 Ass
: Node_Id
:= Empty
;
3632 if Nkind
(Parent
(Call_Node
)) = N_Assignment_Statement
then
3633 Ass
:= Parent
(Call_Node
);
3635 elsif Nkind
(Parent
(Call_Node
)) = N_Qualified_Expression
3636 and then Nkind
(Parent
(Parent
(Call_Node
))) =
3637 N_Assignment_Statement
3639 Ass
:= Parent
(Parent
(Call_Node
));
3641 elsif Nkind
(Parent
(Call_Node
)) = N_Explicit_Dereference
3642 and then Nkind
(Parent
(Parent
(Call_Node
))) =
3643 N_Assignment_Statement
3645 Ass
:= Parent
(Parent
(Call_Node
));
3649 and then Is_Class_Wide_Type
(Etype
(Name
(Ass
)))
3651 if Is_Access_Type
(Etype
(Call_Node
)) then
3652 if Designated_Type
(Etype
(Call_Node
)) /=
3653 Root_Type
(Etype
(Name
(Ass
)))
3656 ("tag-indeterminate expression must have designated "
3657 & "type& (RM 5.2 (6))",
3658 Call_Node
, Root_Type
(Etype
(Name
(Ass
))));
3660 Propagate_Tag
(Name
(Ass
), Call_Node
);
3663 elsif Etype
(Call_Node
) /= Root_Type
(Etype
(Name
(Ass
))) then
3665 ("tag-indeterminate expression must have type & "
3667 Call_Node
, Root_Type
(Etype
(Name
(Ass
))));
3670 Propagate_Tag
(Name
(Ass
), Call_Node
);
3673 -- The call will be rewritten as a dispatching call, and
3674 -- expanded as such.
3681 -- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
3682 -- it to point to the correct secondary virtual table
3684 if Nkind
(Call_Node
) in N_Subprogram_Call
3685 and then CW_Interface_Formals_Present
3687 Expand_Interface_Actuals
(Call_Node
);
3690 -- Deals with Dispatch_Call if we still have a call, before expanding
3691 -- extra actuals since this will be done on the re-analysis of the
3692 -- dispatching call. Note that we do not try to shorten the actual list
3693 -- for a dispatching call, it would not make sense to do so. Expansion
3694 -- of dispatching calls is suppressed for VM targets, because the VM
3695 -- back-ends directly handle the generation of dispatching calls and
3696 -- would have to undo any expansion to an indirect call.
3698 if Nkind
(Call_Node
) in N_Subprogram_Call
3699 and then Present
(Controlling_Argument
(Call_Node
))
3702 Call_Typ
: constant Entity_Id
:= Etype
(Call_Node
);
3703 Typ
: constant Entity_Id
:= Find_Dispatching_Type
(Subp
);
3704 Eq_Prim_Op
: Entity_Id
:= Empty
;
3707 Prev_Call
: Node_Id
;
3710 if not Is_Limited_Type
(Typ
) then
3711 Eq_Prim_Op
:= Find_Prim_Op
(Typ
, Name_Op_Eq
);
3714 if Tagged_Type_Expansion
then
3715 Expand_Dispatching_Call
(Call_Node
);
3717 -- The following return is worrisome. Is it really OK to skip
3718 -- all remaining processing in this procedure ???
3725 Apply_Tag_Checks
(Call_Node
);
3727 -- If this is a dispatching "=", we must first compare the
3728 -- tags so we generate: x.tag = y.tag and then x = y
3730 if Subp
= Eq_Prim_Op
then
3732 -- Mark the node as analyzed to avoid reanalyzing this
3733 -- dispatching call (which would cause a never-ending loop)
3735 Prev_Call
:= Relocate_Node
(Call_Node
);
3736 Set_Analyzed
(Prev_Call
);
3738 Param
:= First_Actual
(Call_Node
);
3744 Make_Selected_Component
(Loc
,
3745 Prefix
=> New_Value
(Param
),
3748 (First_Tag_Component
(Typ
), Loc
)),
3751 Make_Selected_Component
(Loc
,
3753 Unchecked_Convert_To
(Typ
,
3754 New_Value
(Next_Actual
(Param
))),
3757 (First_Tag_Component
(Typ
), Loc
))),
3758 Right_Opnd
=> Prev_Call
);
3760 Rewrite
(Call_Node
, New_Call
);
3763 (Call_Node
, Call_Typ
, Suppress
=> All_Checks
);
3766 -- Expansion of a dispatching call results in an indirect call,
3767 -- which in turn causes current values to be killed (see
3768 -- Resolve_Call), so on VM targets we do the call here to
3769 -- ensure consistent warnings between VM and non-VM targets.
3771 Kill_Current_Values
;
3774 -- If this is a dispatching "=" then we must update the reference
3775 -- to the call node because we generated:
3776 -- x.tag = y.tag and then x = y
3778 if Subp
= Eq_Prim_Op
then
3779 Call_Node
:= Right_Opnd
(Call_Node
);
3784 -- Similarly, expand calls to RCI subprograms on which pragma
3785 -- All_Calls_Remote applies. The rewriting will be reanalyzed
3786 -- later. Do this only when the call comes from source since we
3787 -- do not want such a rewriting to occur in expanded code.
3789 if Is_All_Remote_Call
(Call_Node
) then
3790 Expand_All_Calls_Remote_Subprogram_Call
(Call_Node
);
3792 -- Similarly, do not add extra actuals for an entry call whose entity
3793 -- is a protected procedure, or for an internal protected subprogram
3794 -- call, because it will be rewritten as a protected subprogram call
3795 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
3797 elsif Is_Protected_Type
(Scope
(Subp
))
3798 and then (Ekind
(Subp
) = E_Procedure
3799 or else Ekind
(Subp
) = E_Function
)
3803 -- During that loop we gathered the extra actuals (the ones that
3804 -- correspond to Extra_Formals), so now they can be appended.
3807 while Is_Non_Empty_List
(Extra_Actuals
) loop
3808 Add_Actual_Parameter
(Remove_Head
(Extra_Actuals
));
3812 -- At this point we have all the actuals, so this is the point at which
3813 -- the various expansion activities for actuals is carried out.
3815 Expand_Actuals
(Call_Node
, Subp
, Post_Call
);
3817 -- Verify that the actuals do not share storage. This check must be done
3818 -- on the caller side rather that inside the subprogram to avoid issues
3819 -- of parameter passing.
3821 if Check_Aliasing_Of_Parameters
then
3822 Apply_Parameter_Aliasing_Checks
(Call_Node
, Subp
);
3825 -- If the subprogram is a renaming, or if it is inherited, replace it in
3826 -- the call with the name of the actual subprogram being called. If this
3827 -- is a dispatching call, the run-time decides what to call. The Alias
3828 -- attribute does not apply to entries.
3830 if Nkind
(Call_Node
) /= N_Entry_Call_Statement
3831 and then No
(Controlling_Argument
(Call_Node
))
3832 and then Present
(Parent_Subp
)
3833 and then not Is_Direct_Deep_Call
(Subp
)
3835 if Present
(Inherited_From_Formal
(Subp
)) then
3836 Parent_Subp
:= Inherited_From_Formal
(Subp
);
3838 Parent_Subp
:= Ultimate_Alias
(Parent_Subp
);
3841 -- The below setting of Entity is suspect, see F109-018 discussion???
3843 Set_Entity
(Name
(Call_Node
), Parent_Subp
);
3845 if Is_Abstract_Subprogram
(Parent_Subp
)
3846 and then not In_Instance
3849 ("cannot call abstract subprogram &!",
3850 Name
(Call_Node
), Parent_Subp
);
3853 -- Inspect all formals of derived subprogram Subp. Compare parameter
3854 -- types with the parent subprogram and check whether an actual may
3855 -- need a type conversion to the corresponding formal of the parent
3858 -- Not clear whether intrinsic subprograms need such conversions. ???
3860 if not Is_Intrinsic_Subprogram
(Parent_Subp
)
3861 or else Is_Generic_Instance
(Parent_Subp
)
3864 procedure Convert
(Act
: Node_Id
; Typ
: Entity_Id
);
3865 -- Rewrite node Act as a type conversion of Act to Typ. Analyze
3866 -- and resolve the newly generated construct.
3872 procedure Convert
(Act
: Node_Id
; Typ
: Entity_Id
) is
3874 Rewrite
(Act
, OK_Convert_To
(Typ
, Relocate_Node
(Act
)));
3881 Actual_Typ
: Entity_Id
;
3882 Formal_Typ
: Entity_Id
;
3883 Parent_Typ
: Entity_Id
;
3886 Actual
:= First_Actual
(Call_Node
);
3887 Formal
:= First_Formal
(Subp
);
3888 Parent_Formal
:= First_Formal
(Parent_Subp
);
3889 while Present
(Formal
) loop
3890 Actual_Typ
:= Etype
(Actual
);
3891 Formal_Typ
:= Etype
(Formal
);
3892 Parent_Typ
:= Etype
(Parent_Formal
);
3894 -- For an IN parameter of a scalar type, the parent formal
3895 -- type and derived formal type differ or the parent formal
3896 -- type and actual type do not match statically.
3898 if Is_Scalar_Type
(Formal_Typ
)
3899 and then Ekind
(Formal
) = E_In_Parameter
3900 and then Formal_Typ
/= Parent_Typ
3902 not Subtypes_Statically_Match
(Parent_Typ
, Actual_Typ
)
3903 and then not Raises_Constraint_Error
(Actual
)
3905 Convert
(Actual
, Parent_Typ
);
3906 Enable_Range_Check
(Actual
);
3908 -- If the actual has been marked as requiring a range
3909 -- check, then generate it here.
3911 if Do_Range_Check
(Actual
) then
3912 Generate_Range_Check
3913 (Actual
, Etype
(Formal
), CE_Range_Check_Failed
);
3916 -- For access types, the parent formal type and actual type
3919 elsif Is_Access_Type
(Formal_Typ
)
3920 and then Base_Type
(Parent_Typ
) /= Base_Type
(Actual_Typ
)
3922 if Ekind
(Formal
) /= E_In_Parameter
then
3923 Convert
(Actual
, Parent_Typ
);
3925 elsif Ekind
(Parent_Typ
) = E_Anonymous_Access_Type
3926 and then Designated_Type
(Parent_Typ
) /=
3927 Designated_Type
(Actual_Typ
)
3928 and then not Is_Controlling_Formal
(Formal
)
3930 -- This unchecked conversion is not necessary unless
3931 -- inlining is enabled, because in that case the type
3932 -- mismatch may become visible in the body about to be
3936 Unchecked_Convert_To
(Parent_Typ
,
3937 Relocate_Node
(Actual
)));
3939 Resolve
(Actual
, Parent_Typ
);
3942 -- If there is a change of representation, then generate a
3943 -- warning, and do the change of representation.
3945 elsif not Same_Representation
(Formal_Typ
, Parent_Typ
) then
3947 ("??change of representation required", Actual
);
3948 Convert
(Actual
, Parent_Typ
);
3950 -- For array and record types, the parent formal type and
3951 -- derived formal type have different sizes or pragma Pack
3954 elsif ((Is_Array_Type
(Formal_Typ
)
3955 and then Is_Array_Type
(Parent_Typ
))
3957 (Is_Record_Type
(Formal_Typ
)
3958 and then Is_Record_Type
(Parent_Typ
)))
3960 (Esize
(Formal_Typ
) /= Esize
(Parent_Typ
)
3961 or else Has_Pragma_Pack
(Formal_Typ
) /=
3962 Has_Pragma_Pack
(Parent_Typ
))
3964 Convert
(Actual
, Parent_Typ
);
3967 Next_Actual
(Actual
);
3968 Next_Formal
(Formal
);
3969 Next_Formal
(Parent_Formal
);
3975 Subp
:= Parent_Subp
;
3978 -- Deal with case where call is an explicit dereference
3980 if Nkind
(Name
(Call_Node
)) = N_Explicit_Dereference
then
3982 -- Handle case of access to protected subprogram type
3984 if Is_Access_Protected_Subprogram_Type
3985 (Base_Type
(Etype
(Prefix
(Name
(Call_Node
)))))
3987 -- If this is a call through an access to protected operation, the
3988 -- prefix has the form (object'address, operation'access). Rewrite
3989 -- as a for other protected calls: the object is the 1st parameter
3990 -- of the list of actuals.
3997 Ptr
: constant Node_Id
:= Prefix
(Name
(Call_Node
));
3999 T
: constant Entity_Id
:=
4000 Equivalent_Type
(Base_Type
(Etype
(Ptr
)));
4002 D_T
: constant Entity_Id
:=
4003 Designated_Type
(Base_Type
(Etype
(Ptr
)));
4007 Make_Selected_Component
(Loc
,
4008 Prefix
=> Unchecked_Convert_To
(T
, Ptr
),
4010 New_Occurrence_Of
(First_Entity
(T
), Loc
));
4013 Make_Selected_Component
(Loc
,
4014 Prefix
=> Unchecked_Convert_To
(T
, Ptr
),
4016 New_Occurrence_Of
(Next_Entity
(First_Entity
(T
)), Loc
));
4019 Make_Explicit_Dereference
(Loc
,
4022 if Present
(Parameter_Associations
(Call_Node
)) then
4023 Parm
:= Parameter_Associations
(Call_Node
);
4028 Prepend
(Obj
, Parm
);
4030 if Etype
(D_T
) = Standard_Void_Type
then
4032 Make_Procedure_Call_Statement
(Loc
,
4034 Parameter_Associations
=> Parm
);
4037 Make_Function_Call
(Loc
,
4039 Parameter_Associations
=> Parm
);
4042 Set_First_Named_Actual
(Call
, First_Named_Actual
(Call_Node
));
4043 Set_Etype
(Call
, Etype
(D_T
));
4045 -- We do not re-analyze the call to avoid infinite recursion.
4046 -- We analyze separately the prefix and the object, and set
4047 -- the checks on the prefix that would otherwise be emitted
4048 -- when resolving a call.
4050 Rewrite
(Call_Node
, Call
);
4052 Apply_Access_Check
(Nam
);
4059 -- If this is a call to an intrinsic subprogram, then perform the
4060 -- appropriate expansion to the corresponding tree node and we
4061 -- are all done (since after that the call is gone).
4063 -- In the case where the intrinsic is to be processed by the back end,
4064 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
4065 -- since the idea in this case is to pass the call unchanged. If the
4066 -- intrinsic is an inherited unchecked conversion, and the derived type
4067 -- is the target type of the conversion, we must retain it as the return
4068 -- type of the expression. Otherwise the expansion below, which uses the
4069 -- parent operation, will yield the wrong type.
4071 if Is_Intrinsic_Subprogram
(Subp
) then
4072 Expand_Intrinsic_Call
(Call_Node
, Subp
);
4074 if Nkind
(Call_Node
) = N_Unchecked_Type_Conversion
4075 and then Parent_Subp
/= Orig_Subp
4076 and then Etype
(Parent_Subp
) /= Etype
(Orig_Subp
)
4078 Set_Etype
(Call_Node
, Etype
(Orig_Subp
));
4084 if Ekind_In
(Subp
, E_Function
, E_Procedure
) then
4086 -- We perform a simple optimization on calls for To_Address by
4087 -- replacing them with an unchecked conversion. Not only is this
4088 -- efficient, but it also avoids order of elaboration problems when
4089 -- address clauses are inlined (address expression elaborated at the
4092 -- We perform this optimization regardless of whether we are in the
4093 -- main unit or in a unit in the context of the main unit, to ensure
4094 -- that the generated tree is the same in both cases, for CodePeer
4097 if Is_RTE
(Subp
, RE_To_Address
) then
4099 Unchecked_Convert_To
4100 (RTE
(RE_Address
), Relocate_Node
(First_Actual
(Call_Node
))));
4103 -- A call to a null procedure is replaced by a null statement, but we
4104 -- are not allowed to ignore possible side effects of the call, so we
4105 -- make sure that actuals are evaluated.
4106 -- We also suppress this optimization for GNATCoverage.
4108 elsif Is_Null_Procedure
(Subp
)
4109 and then not Opt
.Suppress_Control_Flow_Optimizations
4111 Actual
:= First_Actual
(Call_Node
);
4112 while Present
(Actual
) loop
4113 Remove_Side_Effects
(Actual
);
4114 Next_Actual
(Actual
);
4117 Rewrite
(Call_Node
, Make_Null_Statement
(Loc
));
4121 -- Handle inlining. No action needed if the subprogram is not inlined
4123 if not Is_Inlined
(Subp
) then
4126 -- Frontend inlining of expression functions (performed also when
4127 -- backend inlining is enabled).
4129 elsif Is_Inlinable_Expression_Function
(Subp
) then
4130 Rewrite
(N
, New_Copy
(Expression_Of_Expression_Function
(Subp
)));
4134 -- Handle frontend inlining
4136 elsif not Back_End_Inlining
then
4137 Inlined_Subprogram
: declare
4139 Must_Inline
: Boolean := False;
4140 Spec
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
4143 -- Verify that the body to inline has already been seen, and
4144 -- that if the body is in the current unit the inlining does
4145 -- not occur earlier. This avoids order-of-elaboration problems
4148 -- This should be documented in sinfo/einfo ???
4151 or else Nkind
(Spec
) /= N_Subprogram_Declaration
4152 or else No
(Body_To_Inline
(Spec
))
4154 Must_Inline
:= False;
4156 -- If this an inherited function that returns a private type,
4157 -- do not inline if the full view is an unconstrained array,
4158 -- because such calls cannot be inlined.
4160 elsif Present
(Orig_Subp
)
4161 and then Is_Array_Type
(Etype
(Orig_Subp
))
4162 and then not Is_Constrained
(Etype
(Orig_Subp
))
4164 Must_Inline
:= False;
4166 elsif In_Unfrozen_Instance
(Scope
(Subp
)) then
4167 Must_Inline
:= False;
4170 Bod
:= Body_To_Inline
(Spec
);
4172 if (In_Extended_Main_Code_Unit
(Call_Node
)
4173 or else In_Extended_Main_Code_Unit
(Parent
(Call_Node
))
4174 or else Has_Pragma_Inline_Always
(Subp
))
4175 and then (not In_Same_Extended_Unit
(Sloc
(Bod
), Loc
)
4177 Earlier_In_Extended_Unit
(Sloc
(Bod
), Loc
))
4179 Must_Inline
:= True;
4181 -- If we are compiling a package body that is not the main
4182 -- unit, it must be for inlining/instantiation purposes,
4183 -- in which case we inline the call to insure that the same
4184 -- temporaries are generated when compiling the body by
4185 -- itself. Otherwise link errors can occur.
4187 -- If the function being called is itself in the main unit,
4188 -- we cannot inline, because there is a risk of double
4189 -- elaboration and/or circularity: the inlining can make
4190 -- visible a private entity in the body of the main unit,
4191 -- that gigi will see before its sees its proper definition.
4193 elsif not (In_Extended_Main_Code_Unit
(Call_Node
))
4194 and then In_Package_Body
4196 Must_Inline
:= not In_Extended_Main_Source_Unit
(Subp
);
4198 -- Inline calls to _postconditions when generating C code
4200 elsif Modify_Tree_For_C
4201 and then In_Same_Extended_Unit
(Sloc
(Bod
), Loc
)
4202 and then Chars
(Name
(N
)) = Name_uPostconditions
4204 Must_Inline
:= True;
4209 Expand_Inlined_Call
(Call_Node
, Subp
, Orig_Subp
);
4212 -- Let the back end handle it
4214 Add_Inlined_Body
(Subp
, Call_Node
);
4216 if Front_End_Inlining
4217 and then Nkind
(Spec
) = N_Subprogram_Declaration
4218 and then (In_Extended_Main_Code_Unit
(Call_Node
))
4219 and then No
(Body_To_Inline
(Spec
))
4220 and then not Has_Completion
(Subp
)
4221 and then In_Same_Extended_Unit
(Sloc
(Spec
), Loc
)
4224 ("cannot inline& (body not seen yet)?",
4228 end Inlined_Subprogram
;
4230 -- Back end inlining: let the back end handle it
4232 elsif No
(Unit_Declaration_Node
(Subp
))
4233 or else Nkind
(Unit_Declaration_Node
(Subp
)) /=
4234 N_Subprogram_Declaration
4235 or else No
(Body_To_Inline
(Unit_Declaration_Node
(Subp
)))
4236 or else Nkind
(Body_To_Inline
(Unit_Declaration_Node
(Subp
))) in
4239 Add_Inlined_Body
(Subp
, Call_Node
);
4241 -- If the inlined call appears within an instantiation and some
4242 -- level of optimization is required, ensure that the enclosing
4243 -- instance body is available so that the back-end can actually
4244 -- perform the inlining.
4247 and then Comes_From_Source
(Subp
)
4248 and then Optimization_Level
> 0
4253 Inst_Node
: Node_Id
;
4256 Inst
:= Scope
(Subp
);
4258 -- Find enclosing instance
4260 while Present
(Inst
) and then Inst
/= Standard_Standard
loop
4261 exit when Is_Generic_Instance
(Inst
);
4262 Inst
:= Scope
(Inst
);
4266 and then Is_Generic_Instance
(Inst
)
4267 and then not Is_Inlined
(Inst
)
4269 Set_Is_Inlined
(Inst
);
4270 Decl
:= Unit_Declaration_Node
(Inst
);
4272 -- Do not add a pending instantiation if the body exits
4273 -- already, or if the instance is a compilation unit, or
4274 -- the instance node is missing.
4276 if Present
(Corresponding_Body
(Decl
))
4277 or else Nkind
(Parent
(Decl
)) = N_Compilation_Unit
4278 or else No
(Next
(Decl
))
4283 -- The instantiation node usually follows the package
4284 -- declaration for the instance. If the generic unit
4285 -- has aspect specifications, they are transformed
4286 -- into pragmas in the instance, and the instance node
4287 -- appears after them.
4289 Inst_Node
:= Next
(Decl
);
4291 while Nkind
(Inst_Node
) /= N_Package_Instantiation
loop
4292 Inst_Node
:= Next
(Inst_Node
);
4295 Add_Pending_Instantiation
(Inst_Node
, Decl
);
4301 -- Front end expansion of simple functions returning unconstrained
4302 -- types (see Check_And_Split_Unconstrained_Function). Note that the
4303 -- case of a simple renaming (Body_To_Inline in N_Entity above, see
4304 -- also Build_Renamed_Body) cannot be expanded here because this may
4305 -- give rise to order-of-elaboration issues for the types of the
4306 -- parameters of the subprogram, if any.
4309 Expand_Inlined_Call
(Call_Node
, Subp
, Orig_Subp
);
4313 -- Check for protected subprogram. This is either an intra-object call,
4314 -- or a protected function call. Protected procedure calls are rewritten
4315 -- as entry calls and handled accordingly.
4317 -- In Ada 2005, this may be an indirect call to an access parameter that
4318 -- is an access_to_subprogram. In that case the anonymous type has a
4319 -- scope that is a protected operation, but the call is a regular one.
4320 -- In either case do not expand call if subprogram is eliminated.
4322 Scop
:= Scope
(Subp
);
4324 if Nkind
(Call_Node
) /= N_Entry_Call_Statement
4325 and then Is_Protected_Type
(Scop
)
4326 and then Ekind
(Subp
) /= E_Subprogram_Type
4327 and then not Is_Eliminated
(Subp
)
4329 -- If the call is an internal one, it is rewritten as a call to the
4330 -- corresponding unprotected subprogram.
4332 Expand_Protected_Subprogram_Call
(Call_Node
, Subp
, Scop
);
4335 -- Functions returning controlled objects need special attention. If
4336 -- the return type is limited, then the context is initialization and
4337 -- different processing applies. If the call is to a protected function,
4338 -- the expansion above will call Expand_Call recursively. Otherwise the
4339 -- function call is transformed into a temporary which obtains the
4340 -- result from the secondary stack.
4342 if Needs_Finalization
(Etype
(Subp
)) then
4343 if not Is_Build_In_Place_Function_Call
(Call_Node
)
4345 (No
(First_Formal
(Subp
))
4347 not Is_Concurrent_Record_Type
(Etype
(First_Formal
(Subp
))))
4349 Expand_Ctrl_Function_Call
(Call_Node
);
4351 -- Build-in-place function calls which appear in anonymous contexts
4352 -- need a transient scope to ensure the proper finalization of the
4353 -- intermediate result after its use.
4355 elsif Is_Build_In_Place_Function_Call
(Call_Node
)
4356 and then Nkind_In
(Parent
(Unqual_Conv
(Call_Node
)),
4357 N_Attribute_Reference
,
4359 N_Indexed_Component
,
4360 N_Object_Renaming_Declaration
,
4361 N_Procedure_Call_Statement
,
4362 N_Selected_Component
,
4365 (Ekind
(Current_Scope
) /= E_Loop
4366 or else Nkind
(Parent
(N
)) /= N_Function_Call
4367 or else not Is_Build_In_Place_Function_Call
(Parent
(N
)))
4369 Establish_Transient_Scope
(Call_Node
, Manage_Sec_Stack
=> True);
4372 end Expand_Call_Helper
;
4374 -------------------------------
4375 -- Expand_Ctrl_Function_Call --
4376 -------------------------------
4378 procedure Expand_Ctrl_Function_Call
(N
: Node_Id
) is
4379 function Is_Element_Reference
(N
: Node_Id
) return Boolean;
4380 -- Determine whether node N denotes a reference to an Ada 2012 container
4383 --------------------------
4384 -- Is_Element_Reference --
4385 --------------------------
4387 function Is_Element_Reference
(N
: Node_Id
) return Boolean is
4388 Ref
: constant Node_Id
:= Original_Node
(N
);
4391 -- Analysis marks an element reference by setting the generalized
4392 -- indexing attribute of an indexed component before the component
4393 -- is rewritten into a function call.
4396 Nkind
(Ref
) = N_Indexed_Component
4397 and then Present
(Generalized_Indexing
(Ref
));
4398 end Is_Element_Reference
;
4400 -- Start of processing for Expand_Ctrl_Function_Call
4403 -- Optimization, if the returned value (which is on the sec-stack) is
4404 -- returned again, no need to copy/readjust/finalize, we can just pass
4405 -- the value thru (see Expand_N_Simple_Return_Statement), and thus no
4406 -- attachment is needed
4408 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
then
4412 -- Resolution is now finished, make sure we don't start analysis again
4413 -- because of the duplication.
4417 -- A function which returns a controlled object uses the secondary
4418 -- stack. Rewrite the call into a temporary which obtains the result of
4419 -- the function using 'reference.
4421 Remove_Side_Effects
(N
);
4423 -- The side effect removal of the function call produced a temporary.
4424 -- When the context is a case expression, if expression, or expression
4425 -- with actions, the lifetime of the temporary must be extended to match
4426 -- that of the context. Otherwise the function result will be finalized
4427 -- too early and affect the result of the expression. To prevent this
4428 -- unwanted effect, the temporary should not be considered for clean up
4429 -- actions by the general finalization machinery.
4431 -- Exception to this rule are references to Ada 2012 container elements.
4432 -- Such references must be finalized at the end of each iteration of the
4433 -- related quantified expression, otherwise the container will remain
4436 if Nkind
(N
) = N_Explicit_Dereference
4437 and then Within_Case_Or_If_Expression
(N
)
4438 and then not Is_Element_Reference
(N
)
4440 Set_Is_Ignored_Transient
(Entity
(Prefix
(N
)));
4442 end Expand_Ctrl_Function_Call
;
4444 ----------------------------------------
4445 -- Expand_N_Extended_Return_Statement --
4446 ----------------------------------------
4448 -- If there is a Handled_Statement_Sequence, we rewrite this:
4450 -- return Result : T := <expression> do
4451 -- <handled_seq_of_stms>
4457 -- Result : T := <expression>;
4459 -- <handled_seq_of_stms>
4463 -- Otherwise (no Handled_Statement_Sequence), we rewrite this:
4465 -- return Result : T := <expression>;
4469 -- return <expression>;
4471 -- unless it's build-in-place or there's no <expression>, in which case
4475 -- Result : T := <expression>;
4480 -- Note that this case could have been written by the user as an extended
4481 -- return statement, or could have been transformed to this from a simple
4482 -- return statement.
4484 -- That is, we need to have a reified return object if there are statements
4485 -- (which might refer to it) or if we're doing build-in-place (so we can
4486 -- set its address to the final resting place or if there is no expression
4487 -- (in which case default initial values might need to be set)).
4489 procedure Expand_N_Extended_Return_Statement
(N
: Node_Id
) is
4490 Loc
: constant Source_Ptr
:= Sloc
(N
);
4492 function Build_Heap_Or_Pool_Allocator
4493 (Temp_Id
: Entity_Id
;
4494 Temp_Typ
: Entity_Id
;
4495 Func_Id
: Entity_Id
;
4496 Ret_Typ
: Entity_Id
;
4497 Alloc_Expr
: Node_Id
) return Node_Id
;
4498 -- Create the statements necessary to allocate a return object on the
4499 -- heap or user-defined storage pool. The object may need finalization
4500 -- actions depending on the return type.
4502 -- * Controlled case
4504 -- if BIPfinalizationmaster = null then
4505 -- Temp_Id := <Alloc_Expr>;
4508 -- type Ptr_Typ is access Ret_Typ;
4509 -- for Ptr_Typ'Storage_Pool use
4510 -- Base_Pool (BIPfinalizationmaster.all).all;
4514 -- procedure Allocate (...) is
4516 -- System.Storage_Pools.Subpools.Allocate_Any (...);
4519 -- Local := <Alloc_Expr>;
4520 -- Temp_Id := Temp_Typ (Local);
4524 -- * Non-controlled case
4526 -- Temp_Id := <Alloc_Expr>;
4528 -- Temp_Id is the temporary which is used to reference the internally
4529 -- created object in all allocation forms. Temp_Typ is the type of the
4530 -- temporary. Func_Id is the enclosing function. Ret_Typ is the return
4531 -- type of Func_Id. Alloc_Expr is the actual allocator.
4533 function Move_Activation_Chain
(Func_Id
: Entity_Id
) return Node_Id
;
4534 -- Construct a call to System.Tasking.Stages.Move_Activation_Chain
4536 -- From current activation chain
4537 -- To activation chain passed in by the caller
4538 -- New_Master master passed in by the caller
4540 -- Func_Id is the entity of the function where the extended return
4541 -- statement appears.
4543 ----------------------------------
4544 -- Build_Heap_Or_Pool_Allocator --
4545 ----------------------------------
4547 function Build_Heap_Or_Pool_Allocator
4548 (Temp_Id
: Entity_Id
;
4549 Temp_Typ
: Entity_Id
;
4550 Func_Id
: Entity_Id
;
4551 Ret_Typ
: Entity_Id
;
4552 Alloc_Expr
: Node_Id
) return Node_Id
4555 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
4557 -- Processing for objects that require finalization actions
4559 if Needs_Finalization
(Ret_Typ
) then
4561 Decls
: constant List_Id
:= New_List
;
4562 Fin_Mas_Id
: constant Entity_Id
:=
4563 Build_In_Place_Formal
4564 (Func_Id
, BIP_Finalization_Master
);
4565 Orig_Expr
: constant Node_Id
:=
4567 (Source
=> Alloc_Expr
,
4568 Scopes_In_EWA_OK
=> True);
4569 Stmts
: constant List_Id
:= New_List
;
4570 Desig_Typ
: Entity_Id
;
4571 Local_Id
: Entity_Id
;
4572 Pool_Id
: Entity_Id
;
4573 Ptr_Typ
: Entity_Id
;
4577 -- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
4579 Pool_Id
:= Make_Temporary
(Loc
, 'P');
4582 Make_Object_Renaming_Declaration
(Loc
,
4583 Defining_Identifier
=> Pool_Id
,
4585 New_Occurrence_Of
(RTE
(RE_Root_Storage_Pool
), Loc
),
4587 Make_Explicit_Dereference
(Loc
,
4589 Make_Function_Call
(Loc
,
4591 New_Occurrence_Of
(RTE
(RE_Base_Pool
), Loc
),
4592 Parameter_Associations
=> New_List
(
4593 Make_Explicit_Dereference
(Loc
,
4595 New_Occurrence_Of
(Fin_Mas_Id
, Loc
)))))));
4597 -- Create an access type which uses the storage pool of the
4598 -- caller's master. This additional type is necessary because
4599 -- the finalization master cannot be associated with the type
4600 -- of the temporary. Otherwise the secondary stack allocation
4603 Desig_Typ
:= Ret_Typ
;
4605 -- Ensure that the build-in-place machinery uses a fat pointer
4606 -- when allocating an unconstrained array on the heap. In this
4607 -- case the result object type is a constrained array type even
4608 -- though the function type is unconstrained.
4610 if Ekind
(Desig_Typ
) = E_Array_Subtype
then
4611 Desig_Typ
:= Base_Type
(Desig_Typ
);
4615 -- type Ptr_Typ is access Desig_Typ;
4617 Ptr_Typ
:= Make_Temporary
(Loc
, 'P');
4620 Make_Full_Type_Declaration
(Loc
,
4621 Defining_Identifier
=> Ptr_Typ
,
4623 Make_Access_To_Object_Definition
(Loc
,
4624 Subtype_Indication
=>
4625 New_Occurrence_Of
(Desig_Typ
, Loc
))));
4627 -- Perform minor decoration in order to set the master and the
4628 -- storage pool attributes.
4630 Set_Ekind
(Ptr_Typ
, E_Access_Type
);
4631 Set_Finalization_Master
(Ptr_Typ
, Fin_Mas_Id
);
4632 Set_Associated_Storage_Pool
(Ptr_Typ
, Pool_Id
);
4634 -- Create the temporary, generate:
4635 -- Local_Id : Ptr_Typ;
4637 Local_Id
:= Make_Temporary
(Loc
, 'T');
4640 Make_Object_Declaration
(Loc
,
4641 Defining_Identifier
=> Local_Id
,
4642 Object_Definition
=>
4643 New_Occurrence_Of
(Ptr_Typ
, Loc
)));
4645 -- Allocate the object, generate:
4646 -- Local_Id := <Alloc_Expr>;
4649 Make_Assignment_Statement
(Loc
,
4650 Name
=> New_Occurrence_Of
(Local_Id
, Loc
),
4651 Expression
=> Alloc_Expr
));
4654 -- Temp_Id := Temp_Typ (Local_Id);
4657 Make_Assignment_Statement
(Loc
,
4658 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4660 Unchecked_Convert_To
(Temp_Typ
,
4661 New_Occurrence_Of
(Local_Id
, Loc
))));
4663 -- Wrap the allocation in a block. This is further conditioned
4664 -- by checking the caller finalization master at runtime. A
4665 -- null value indicates a non-existent master, most likely due
4666 -- to a Finalize_Storage_Only allocation.
4669 -- if BIPfinalizationmaster = null then
4670 -- Temp_Id := <Orig_Expr>;
4680 Make_If_Statement
(Loc
,
4683 Left_Opnd
=> New_Occurrence_Of
(Fin_Mas_Id
, Loc
),
4684 Right_Opnd
=> Make_Null
(Loc
)),
4686 Then_Statements
=> New_List
(
4687 Make_Assignment_Statement
(Loc
,
4688 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4689 Expression
=> Orig_Expr
)),
4691 Else_Statements
=> New_List
(
4692 Make_Block_Statement
(Loc
,
4693 Declarations
=> Decls
,
4694 Handled_Statement_Sequence
=>
4695 Make_Handled_Sequence_Of_Statements
(Loc
,
4696 Statements
=> Stmts
))));
4699 -- For all other cases, generate:
4700 -- Temp_Id := <Alloc_Expr>;
4704 Make_Assignment_Statement
(Loc
,
4705 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4706 Expression
=> Alloc_Expr
);
4708 end Build_Heap_Or_Pool_Allocator
;
4710 ---------------------------
4711 -- Move_Activation_Chain --
4712 ---------------------------
4714 function Move_Activation_Chain
(Func_Id
: Entity_Id
) return Node_Id
is
4717 Make_Procedure_Call_Statement
(Loc
,
4719 New_Occurrence_Of
(RTE
(RE_Move_Activation_Chain
), Loc
),
4721 Parameter_Associations
=> New_List
(
4725 Make_Attribute_Reference
(Loc
,
4726 Prefix
=> Make_Identifier
(Loc
, Name_uChain
),
4727 Attribute_Name
=> Name_Unrestricted_Access
),
4729 -- Destination chain
4732 (Build_In_Place_Formal
(Func_Id
, BIP_Activation_Chain
), Loc
),
4737 (Build_In_Place_Formal
(Func_Id
, BIP_Task_Master
), Loc
)));
4738 end Move_Activation_Chain
;
4742 Func_Id
: constant Entity_Id
:=
4743 Return_Applies_To
(Return_Statement_Entity
(N
));
4744 Is_BIP_Func
: constant Boolean :=
4745 Is_Build_In_Place_Function
(Func_Id
);
4746 Ret_Obj_Id
: constant Entity_Id
:=
4747 First_Entity
(Return_Statement_Entity
(N
));
4748 Ret_Obj_Decl
: constant Node_Id
:= Parent
(Ret_Obj_Id
);
4749 Ret_Typ
: constant Entity_Id
:= Etype
(Func_Id
);
4756 Return_Stmt
: Node_Id
:= Empty
;
4757 -- Force initialization to facilitate static analysis
4759 -- Start of processing for Expand_N_Extended_Return_Statement
4762 -- Given that functionality of interface thunks is simple (just displace
4763 -- the pointer to the object) they are always handled by means of
4764 -- simple return statements.
4766 pragma Assert
(not Is_Thunk
(Current_Scope
));
4768 if Nkind
(Ret_Obj_Decl
) = N_Object_Declaration
then
4769 Exp
:= Expression
(Ret_Obj_Decl
);
4771 -- Assert that if F says "return R : T := G(...) do..."
4772 -- then F and G are both b-i-p, or neither b-i-p.
4774 if Nkind
(Exp
) = N_Function_Call
then
4775 pragma Assert
(Ekind
(Current_Scope
) = E_Function
);
4777 (Is_Build_In_Place_Function
(Current_Scope
) =
4778 Is_Build_In_Place_Function_Call
(Exp
));
4785 HSS
:= Handled_Statement_Sequence
(N
);
4787 -- If the returned object needs finalization actions, the function must
4788 -- perform the appropriate cleanup should it fail to return. The state
4789 -- of the function itself is tracked through a flag which is coupled
4790 -- with the scope finalizer. There is one flag per each return object
4791 -- in case of multiple returns.
4793 if Is_BIP_Func
and then Needs_Finalization
(Etype
(Ret_Obj_Id
)) then
4795 Flag_Decl
: Node_Id
;
4796 Flag_Id
: Entity_Id
;
4800 -- Recover the function body
4802 Func_Bod
:= Unit_Declaration_Node
(Func_Id
);
4804 if Nkind
(Func_Bod
) = N_Subprogram_Declaration
then
4805 Func_Bod
:= Parent
(Parent
(Corresponding_Body
(Func_Bod
)));
4808 if Nkind
(Func_Bod
) = N_Function_Specification
then
4809 Func_Bod
:= Parent
(Func_Bod
); -- one more level for child units
4812 pragma Assert
(Nkind
(Func_Bod
) = N_Subprogram_Body
);
4814 -- Create a flag to track the function state
4816 Flag_Id
:= Make_Temporary
(Loc
, 'F');
4817 Set_Status_Flag_Or_Transient_Decl
(Ret_Obj_Id
, Flag_Id
);
4819 -- Insert the flag at the beginning of the function declarations,
4821 -- Fnn : Boolean := False;
4824 Make_Object_Declaration
(Loc
,
4825 Defining_Identifier
=> Flag_Id
,
4826 Object_Definition
=>
4827 New_Occurrence_Of
(Standard_Boolean
, Loc
),
4829 New_Occurrence_Of
(Standard_False
, Loc
));
4831 Prepend_To
(Declarations
(Func_Bod
), Flag_Decl
);
4832 Analyze
(Flag_Decl
);
4836 -- Build a simple_return_statement that returns the return object when
4837 -- there is a statement sequence, or no expression, or the result will
4838 -- be built in place. Note however that we currently do this for all
4839 -- composite cases, even though not all are built in place.
4842 or else Is_Composite_Type
(Ret_Typ
)
4848 -- If the extended return has a handled statement sequence, then wrap
4849 -- it in a block and use the block as the first statement.
4853 Make_Block_Statement
(Loc
,
4854 Declarations
=> New_List
,
4855 Handled_Statement_Sequence
=> HSS
));
4858 -- If the result type contains tasks, we call Move_Activation_Chain.
4859 -- Later, the cleanup code will call Complete_Master, which will
4860 -- terminate any unactivated tasks belonging to the return statement
4861 -- master. But Move_Activation_Chain updates their master to be that
4862 -- of the caller, so they will not be terminated unless the return
4863 -- statement completes unsuccessfully due to exception, abort, goto,
4864 -- or exit. As a formality, we test whether the function requires the
4865 -- result to be built in place, though that's necessarily true for
4866 -- the case of result types with task parts.
4868 if Is_BIP_Func
and then Has_Task
(Ret_Typ
) then
4870 -- The return expression is an aggregate for a complex type which
4871 -- contains tasks. This particular case is left unexpanded since
4872 -- the regular expansion would insert all temporaries and
4873 -- initialization code in the wrong block.
4875 if Nkind
(Exp
) = N_Aggregate
then
4876 Expand_N_Aggregate
(Exp
);
4879 -- Do not move the activation chain if the return object does not
4882 if Has_Task
(Etype
(Ret_Obj_Id
)) then
4883 Append_To
(Stmts
, Move_Activation_Chain
(Func_Id
));
4887 -- Update the state of the function right before the object is
4890 if Is_BIP_Func
and then Needs_Finalization
(Etype
(Ret_Obj_Id
)) then
4892 Flag_Id
: constant Entity_Id
:=
4893 Status_Flag_Or_Transient_Decl
(Ret_Obj_Id
);
4900 Make_Assignment_Statement
(Loc
,
4901 Name
=> New_Occurrence_Of
(Flag_Id
, Loc
),
4902 Expression
=> New_Occurrence_Of
(Standard_True
, Loc
)));
4906 -- Build a simple_return_statement that returns the return object
4909 Make_Simple_Return_Statement
(Loc
,
4910 Expression
=> New_Occurrence_Of
(Ret_Obj_Id
, Loc
));
4911 Append_To
(Stmts
, Return_Stmt
);
4913 HSS
:= Make_Handled_Sequence_Of_Statements
(Loc
, Stmts
);
4916 -- Case where we build a return statement block
4918 if Present
(HSS
) then
4920 Make_Block_Statement
(Loc
,
4921 Declarations
=> Return_Object_Declarations
(N
),
4922 Handled_Statement_Sequence
=> HSS
);
4924 -- We set the entity of the new block statement to be that of the
4925 -- return statement. This is necessary so that various fields, such
4926 -- as Finalization_Chain_Entity carry over from the return statement
4927 -- to the block. Note that this block is unusual, in that its entity
4928 -- is an E_Return_Statement rather than an E_Block.
4931 (Result
, New_Occurrence_Of
(Return_Statement_Entity
(N
), Loc
));
4933 -- If the object decl was already rewritten as a renaming, then we
4934 -- don't want to do the object allocation and transformation of
4935 -- the return object declaration to a renaming. This case occurs
4936 -- when the return object is initialized by a call to another
4937 -- build-in-place function, and that function is responsible for
4938 -- the allocation of the return object.
4941 and then Nkind
(Ret_Obj_Decl
) = N_Object_Renaming_Declaration
4944 (Nkind
(Original_Node
(Ret_Obj_Decl
)) = N_Object_Declaration
4947 -- It is a regular BIP object declaration
4949 (Is_Build_In_Place_Function_Call
4950 (Expression
(Original_Node
(Ret_Obj_Decl
)))
4952 -- It is a BIP object declaration that displaces the pointer
4953 -- to the object to reference a convered interface type.
4956 Present
(Unqual_BIP_Iface_Function_Call
4957 (Expression
(Original_Node
(Ret_Obj_Decl
))))));
4959 -- Return the build-in-place result by reference
4961 Set_By_Ref
(Return_Stmt
);
4963 elsif Is_BIP_Func
then
4965 -- Locate the implicit access parameter associated with the
4966 -- caller-supplied return object and convert the return
4967 -- statement's return object declaration to a renaming of a
4968 -- dereference of the access parameter. If the return object's
4969 -- declaration includes an expression that has not already been
4970 -- expanded as separate assignments, then add an assignment
4971 -- statement to ensure the return object gets initialized.
4974 -- Result : T [:= <expression>];
4981 -- Result : T renames FuncRA.all;
4982 -- [Result := <expression;]
4987 Ret_Obj_Expr
: constant Node_Id
:= Expression
(Ret_Obj_Decl
);
4988 Ret_Obj_Typ
: constant Entity_Id
:= Etype
(Ret_Obj_Id
);
4990 Init_Assignment
: Node_Id
:= Empty
;
4991 Obj_Acc_Formal
: Entity_Id
;
4992 Obj_Acc_Deref
: Node_Id
;
4993 Obj_Alloc_Formal
: Entity_Id
;
4996 -- Build-in-place results must be returned by reference
4998 Set_By_Ref
(Return_Stmt
);
5000 -- Retrieve the implicit access parameter passed by the caller
5003 Build_In_Place_Formal
(Func_Id
, BIP_Object_Access
);
5005 -- If the return object's declaration includes an expression
5006 -- and the declaration isn't marked as No_Initialization, then
5007 -- we need to generate an assignment to the object and insert
5008 -- it after the declaration before rewriting it as a renaming
5009 -- (otherwise we'll lose the initialization). The case where
5010 -- the result type is an interface (or class-wide interface)
5011 -- is also excluded because the context of the function call
5012 -- must be unconstrained, so the initialization will always
5013 -- be done as part of an allocator evaluation (storage pool
5014 -- or secondary stack), never to a constrained target object
5015 -- passed in by the caller. Besides the assignment being
5016 -- unneeded in this case, it avoids problems with trying to
5017 -- generate a dispatching assignment when the return expression
5018 -- is a nonlimited descendant of a limited interface (the
5019 -- interface has no assignment operation).
5021 if Present
(Ret_Obj_Expr
)
5022 and then not No_Initialization
(Ret_Obj_Decl
)
5023 and then not Is_Interface
(Ret_Obj_Typ
)
5026 Make_Assignment_Statement
(Loc
,
5027 Name
=> New_Occurrence_Of
(Ret_Obj_Id
, Loc
),
5030 (Source
=> Ret_Obj_Expr
,
5031 Scopes_In_EWA_OK
=> True));
5033 Set_Etype
(Name
(Init_Assignment
), Etype
(Ret_Obj_Id
));
5034 Set_Assignment_OK
(Name
(Init_Assignment
));
5035 Set_No_Ctrl_Actions
(Init_Assignment
);
5037 Set_Parent
(Name
(Init_Assignment
), Init_Assignment
);
5038 Set_Parent
(Expression
(Init_Assignment
), Init_Assignment
);
5040 Set_Expression
(Ret_Obj_Decl
, Empty
);
5042 if Is_Class_Wide_Type
(Etype
(Ret_Obj_Id
))
5043 and then not Is_Class_Wide_Type
5044 (Etype
(Expression
(Init_Assignment
)))
5046 Rewrite
(Expression
(Init_Assignment
),
5047 Make_Type_Conversion
(Loc
,
5049 New_Occurrence_Of
(Etype
(Ret_Obj_Id
), Loc
),
5051 Relocate_Node
(Expression
(Init_Assignment
))));
5054 -- In the case of functions where the calling context can
5055 -- determine the form of allocation needed, initialization
5056 -- is done with each part of the if statement that handles
5057 -- the different forms of allocation (this is true for
5058 -- unconstrained, tagged, and controlled result subtypes).
5060 if not Needs_BIP_Alloc_Form
(Func_Id
) then
5061 Insert_After
(Ret_Obj_Decl
, Init_Assignment
);
5065 -- When the function's subtype is unconstrained, a run-time
5066 -- test is needed to determine the form of allocation to use
5067 -- for the return object. The function has an implicit formal
5068 -- parameter indicating this. If the BIP_Alloc_Form formal has
5069 -- the value one, then the caller has passed access to an
5070 -- existing object for use as the return object. If the value
5071 -- is two, then the return object must be allocated on the
5072 -- secondary stack. Otherwise, the object must be allocated in
5073 -- a storage pool. We generate an if statement to test the
5074 -- implicit allocation formal and initialize a local access
5075 -- value appropriately, creating allocators in the secondary
5076 -- stack and global heap cases. The special formal also exists
5077 -- and must be tested when the function has a tagged result,
5078 -- even when the result subtype is constrained, because in
5079 -- general such functions can be called in dispatching contexts
5080 -- and must be handled similarly to functions with a class-wide
5083 if Needs_BIP_Alloc_Form
(Func_Id
) then
5085 Build_In_Place_Formal
(Func_Id
, BIP_Alloc_Form
);
5088 Pool_Id
: constant Entity_Id
:=
5089 Make_Temporary
(Loc
, 'P');
5090 Alloc_Obj_Id
: Entity_Id
;
5091 Alloc_Obj_Decl
: Node_Id
;
5092 Alloc_If_Stmt
: Node_Id
;
5093 Heap_Allocator
: Node_Id
;
5094 Pool_Decl
: Node_Id
;
5095 Pool_Allocator
: Node_Id
;
5096 Ptr_Type_Decl
: Node_Id
;
5097 Ref_Type
: Entity_Id
;
5098 SS_Allocator
: Node_Id
;
5101 -- Reuse the itype created for the function's implicit
5102 -- access formal. This avoids the need to create a new
5103 -- access type here, plus it allows assigning the access
5104 -- formal directly without applying a conversion.
5106 -- Ref_Type := Etype (Object_Access);
5108 -- Create an access type designating the function's
5111 Ref_Type
:= Make_Temporary
(Loc
, 'A');
5114 Make_Full_Type_Declaration
(Loc
,
5115 Defining_Identifier
=> Ref_Type
,
5117 Make_Access_To_Object_Definition
(Loc
,
5118 All_Present
=> True,
5119 Subtype_Indication
=>
5120 New_Occurrence_Of
(Ret_Obj_Typ
, Loc
)));
5122 Insert_Before
(Ret_Obj_Decl
, Ptr_Type_Decl
);
5124 -- Create an access object that will be initialized to an
5125 -- access value denoting the return object, either coming
5126 -- from an implicit access value passed in by the caller
5127 -- or from the result of an allocator.
5129 Alloc_Obj_Id
:= Make_Temporary
(Loc
, 'R');
5130 Set_Etype
(Alloc_Obj_Id
, Ref_Type
);
5133 Make_Object_Declaration
(Loc
,
5134 Defining_Identifier
=> Alloc_Obj_Id
,
5135 Object_Definition
=>
5136 New_Occurrence_Of
(Ref_Type
, Loc
));
5138 Insert_Before
(Ret_Obj_Decl
, Alloc_Obj_Decl
);
5140 -- Create allocators for both the secondary stack and
5141 -- global heap. If there's an initialization expression,
5142 -- then create these as initialized allocators.
5144 if Present
(Ret_Obj_Expr
)
5145 and then not No_Initialization
(Ret_Obj_Decl
)
5147 -- Always use the type of the expression for the
5148 -- qualified expression, rather than the result type.
5149 -- In general we cannot always use the result type
5150 -- for the allocator, because the expression might be
5151 -- of a specific type, such as in the case of an
5152 -- aggregate or even a nonlimited object when the
5153 -- result type is a limited class-wide interface type.
5156 Make_Allocator
(Loc
,
5158 Make_Qualified_Expression
(Loc
,
5161 (Etype
(Ret_Obj_Expr
), Loc
),
5164 (Source
=> Ret_Obj_Expr
,
5165 Scopes_In_EWA_OK
=> True)));
5168 -- If the function returns a class-wide type we cannot
5169 -- use the return type for the allocator. Instead we
5170 -- use the type of the expression, which must be an
5171 -- aggregate of a definite type.
5173 if Is_Class_Wide_Type
(Ret_Obj_Typ
) then
5175 Make_Allocator
(Loc
,
5178 (Etype
(Ret_Obj_Expr
), Loc
));
5181 Make_Allocator
(Loc
,
5183 New_Occurrence_Of
(Ret_Obj_Typ
, Loc
));
5186 -- If the object requires default initialization then
5187 -- that will happen later following the elaboration of
5188 -- the object renaming. If we don't turn it off here
5189 -- then the object will be default initialized twice.
5191 Set_No_Initialization
(Heap_Allocator
);
5194 -- Set the flag indicating that the allocator came from
5195 -- a build-in-place return statement, so we can avoid
5196 -- adjusting the allocated object. Note that this flag
5197 -- will be inherited by the copies made below.
5199 Set_Alloc_For_BIP_Return
(Heap_Allocator
);
5201 -- The Pool_Allocator is just like the Heap_Allocator,
5202 -- except we set Storage_Pool and Procedure_To_Call so
5203 -- it will use the user-defined storage pool.
5207 (Source
=> Heap_Allocator
,
5208 Scopes_In_EWA_OK
=> True);
5210 pragma Assert
(Alloc_For_BIP_Return
(Pool_Allocator
));
5212 -- Do not generate the renaming of the build-in-place
5213 -- pool parameter on ZFP because the parameter is not
5214 -- created in the first place.
5216 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
5218 Make_Object_Renaming_Declaration
(Loc
,
5219 Defining_Identifier
=> Pool_Id
,
5222 (RTE
(RE_Root_Storage_Pool
), Loc
),
5224 Make_Explicit_Dereference
(Loc
,
5226 (Build_In_Place_Formal
5227 (Func_Id
, BIP_Storage_Pool
), Loc
)));
5228 Set_Storage_Pool
(Pool_Allocator
, Pool_Id
);
5229 Set_Procedure_To_Call
5230 (Pool_Allocator
, RTE
(RE_Allocate_Any
));
5232 Pool_Decl
:= Make_Null_Statement
(Loc
);
5235 -- If the No_Allocators restriction is active, then only
5236 -- an allocator for secondary stack allocation is needed.
5237 -- It's OK for such allocators to have Comes_From_Source
5238 -- set to False, because gigi knows not to flag them as
5239 -- being a violation of No_Implicit_Heap_Allocations.
5241 if Restriction_Active
(No_Allocators
) then
5242 SS_Allocator
:= Heap_Allocator
;
5243 Heap_Allocator
:= Make_Null
(Loc
);
5244 Pool_Allocator
:= Make_Null
(Loc
);
5246 -- Otherwise the heap and pool allocators may be needed,
5247 -- so we make another allocator for secondary stack
5253 (Source
=> Heap_Allocator
,
5254 Scopes_In_EWA_OK
=> True);
5256 pragma Assert
(Alloc_For_BIP_Return
(SS_Allocator
));
5258 -- The heap and pool allocators are marked as
5259 -- Comes_From_Source since they correspond to an
5260 -- explicit user-written allocator (that is, it will
5261 -- only be executed on behalf of callers that call the
5262 -- function as initialization for such an allocator).
5263 -- Prevents errors when No_Implicit_Heap_Allocations
5266 Set_Comes_From_Source
(Heap_Allocator
, True);
5267 Set_Comes_From_Source
(Pool_Allocator
, True);
5270 -- The allocator is returned on the secondary stack.
5272 Set_Storage_Pool
(SS_Allocator
, RTE
(RE_SS_Pool
));
5273 Set_Procedure_To_Call
5274 (SS_Allocator
, RTE
(RE_SS_Allocate
));
5276 -- The allocator is returned on the secondary stack,
5277 -- so indicate that the function return, as well as
5278 -- all blocks that encloses the allocator, must not
5279 -- release it. The flags must be set now because
5280 -- the decision to use the secondary stack is done
5281 -- very late in the course of expanding the return
5282 -- statement, past the point where these flags are
5285 Set_Uses_Sec_Stack
(Func_Id
);
5286 Set_Uses_Sec_Stack
(Return_Statement_Entity
(N
));
5287 Set_Sec_Stack_Needed_For_Return
5288 (Return_Statement_Entity
(N
));
5289 Set_Enclosing_Sec_Stack_Return
(N
);
5291 -- Create an if statement to test the BIP_Alloc_Form
5292 -- formal and initialize the access object to either the
5293 -- BIP_Object_Access formal (BIP_Alloc_Form =
5294 -- Caller_Allocation), the result of allocating the
5295 -- object in the secondary stack (BIP_Alloc_Form =
5296 -- Secondary_Stack), or else an allocator to create the
5297 -- return object in the heap or user-defined pool
5298 -- (BIP_Alloc_Form = Global_Heap or User_Storage_Pool).
5300 -- ??? An unchecked type conversion must be made in the
5301 -- case of assigning the access object formal to the
5302 -- local access object, because a normal conversion would
5303 -- be illegal in some cases (such as converting access-
5304 -- to-unconstrained to access-to-constrained), but the
5305 -- the unchecked conversion will presumably fail to work
5306 -- right in just such cases. It's not clear at all how to
5310 Make_If_Statement
(Loc
,
5314 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5316 Make_Integer_Literal
(Loc
,
5317 UI_From_Int
(BIP_Allocation_Form
'Pos
5318 (Caller_Allocation
)))),
5320 Then_Statements
=> New_List
(
5321 Make_Assignment_Statement
(Loc
,
5323 New_Occurrence_Of
(Alloc_Obj_Id
, Loc
),
5325 Make_Unchecked_Type_Conversion
(Loc
,
5327 New_Occurrence_Of
(Ref_Type
, Loc
),
5329 New_Occurrence_Of
(Obj_Acc_Formal
, Loc
)))),
5331 Elsif_Parts
=> New_List
(
5332 Make_Elsif_Part
(Loc
,
5336 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5338 Make_Integer_Literal
(Loc
,
5339 UI_From_Int
(BIP_Allocation_Form
'Pos
5340 (Secondary_Stack
)))),
5342 Then_Statements
=> New_List
(
5343 Make_Assignment_Statement
(Loc
,
5345 New_Occurrence_Of
(Alloc_Obj_Id
, Loc
),
5346 Expression
=> SS_Allocator
))),
5348 Make_Elsif_Part
(Loc
,
5352 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5354 Make_Integer_Literal
(Loc
,
5355 UI_From_Int
(BIP_Allocation_Form
'Pos
5358 Then_Statements
=> New_List
(
5359 Build_Heap_Or_Pool_Allocator
5360 (Temp_Id
=> Alloc_Obj_Id
,
5361 Temp_Typ
=> Ref_Type
,
5363 Ret_Typ
=> Ret_Obj_Typ
,
5364 Alloc_Expr
=> Heap_Allocator
))),
5366 -- ???If all is well, we can put the following
5367 -- 'elsif' in the 'else', but this is a useful
5368 -- self-check in case caller and callee don't agree
5369 -- on whether BIPAlloc and so on should be passed.
5371 Make_Elsif_Part
(Loc
,
5375 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5377 Make_Integer_Literal
(Loc
,
5378 UI_From_Int
(BIP_Allocation_Form
'Pos
5379 (User_Storage_Pool
)))),
5381 Then_Statements
=> New_List
(
5383 Build_Heap_Or_Pool_Allocator
5384 (Temp_Id
=> Alloc_Obj_Id
,
5385 Temp_Typ
=> Ref_Type
,
5387 Ret_Typ
=> Ret_Obj_Typ
,
5388 Alloc_Expr
=> Pool_Allocator
)))),
5390 -- Raise Program_Error if it's none of the above;
5391 -- this is a compiler bug.
5393 Else_Statements
=> New_List
(
5394 Make_Raise_Program_Error
(Loc
,
5395 Reason
=> PE_Build_In_Place_Mismatch
)));
5397 -- If a separate initialization assignment was created
5398 -- earlier, append that following the assignment of the
5399 -- implicit access formal to the access object, to ensure
5400 -- that the return object is initialized in that case. In
5401 -- this situation, the target of the assignment must be
5402 -- rewritten to denote a dereference of the access to the
5403 -- return object passed in by the caller.
5405 if Present
(Init_Assignment
) then
5406 Rewrite
(Name
(Init_Assignment
),
5407 Make_Explicit_Dereference
(Loc
,
5408 Prefix
=> New_Occurrence_Of
(Alloc_Obj_Id
, Loc
)));
5411 (Original_Node
(Name
(Init_Assignment
))));
5412 Set_Assignment_OK
(Name
(Init_Assignment
));
5414 Set_Etype
(Name
(Init_Assignment
), Etype
(Ret_Obj_Id
));
5417 (Then_Statements
(Alloc_If_Stmt
), Init_Assignment
);
5420 Insert_Before
(Ret_Obj_Decl
, Alloc_If_Stmt
);
5422 -- Remember the local access object for use in the
5423 -- dereference of the renaming created below.
5425 Obj_Acc_Formal
:= Alloc_Obj_Id
;
5429 -- Replace the return object declaration with a renaming of a
5430 -- dereference of the access value designating the return
5434 Make_Explicit_Dereference
(Loc
,
5435 Prefix
=> New_Occurrence_Of
(Obj_Acc_Formal
, Loc
));
5437 Rewrite
(Ret_Obj_Decl
,
5438 Make_Object_Renaming_Declaration
(Loc
,
5439 Defining_Identifier
=> Ret_Obj_Id
,
5440 Access_Definition
=> Empty
,
5441 Subtype_Mark
=> New_Occurrence_Of
(Ret_Obj_Typ
, Loc
),
5442 Name
=> Obj_Acc_Deref
));
5444 Set_Renamed_Object
(Ret_Obj_Id
, Obj_Acc_Deref
);
5448 -- Case where we do not build a block
5451 -- We're about to drop Return_Object_Declarations on the floor, so
5452 -- we need to insert it, in case it got expanded into useful code.
5453 -- Remove side effects from expression, which may be duplicated in
5454 -- subsequent checks (see Expand_Simple_Function_Return).
5456 Insert_List_Before
(N
, Return_Object_Declarations
(N
));
5457 Remove_Side_Effects
(Exp
);
5459 -- Build simple_return_statement that returns the expression directly
5461 Return_Stmt
:= Make_Simple_Return_Statement
(Loc
, Expression
=> Exp
);
5462 Result
:= Return_Stmt
;
5465 -- Set the flag to prevent infinite recursion
5467 Set_Comes_From_Extended_Return_Statement
(Return_Stmt
);
5469 Rewrite
(N
, Result
);
5471 end Expand_N_Extended_Return_Statement
;
5473 ----------------------------
5474 -- Expand_N_Function_Call --
5475 ----------------------------
5477 procedure Expand_N_Function_Call
(N
: Node_Id
) is
5480 end Expand_N_Function_Call
;
5482 ---------------------------------------
5483 -- Expand_N_Procedure_Call_Statement --
5484 ---------------------------------------
5486 procedure Expand_N_Procedure_Call_Statement
(N
: Node_Id
) is
5489 end Expand_N_Procedure_Call_Statement
;
5491 --------------------------------------
5492 -- Expand_N_Simple_Return_Statement --
5493 --------------------------------------
5495 procedure Expand_N_Simple_Return_Statement
(N
: Node_Id
) is
5497 -- Defend against previous errors (i.e. the return statement calls a
5498 -- function that is not available in configurable runtime).
5500 if Present
(Expression
(N
))
5501 and then Nkind
(Expression
(N
)) = N_Empty
5503 Check_Error_Detected
;
5507 -- Distinguish the function and non-function cases:
5509 case Ekind
(Return_Applies_To
(Return_Statement_Entity
(N
))) is
5511 | E_Generic_Function
5513 Expand_Simple_Function_Return
(N
);
5517 | E_Generic_Procedure
5519 | E_Return_Statement
5521 Expand_Non_Function_Return
(N
);
5524 raise Program_Error
;
5528 when RE_Not_Available
=>
5530 end Expand_N_Simple_Return_Statement
;
5532 ------------------------------
5533 -- Expand_N_Subprogram_Body --
5534 ------------------------------
5536 -- Add poll call if ATC polling is enabled, unless the body will be inlined
5539 -- Add dummy push/pop label nodes at start and end to clear any local
5540 -- exception indications if local-exception-to-goto optimization is active.
5542 -- Add return statement if last statement in body is not a return statement
5543 -- (this makes things easier on Gigi which does not want to have to handle
5544 -- a missing return).
5546 -- Add call to Activate_Tasks if body is a task activator
5548 -- Deal with possible detection of infinite recursion
5550 -- Eliminate body completely if convention stubbed
5552 -- Encode entity names within body, since we will not need to reference
5553 -- these entities any longer in the front end.
5555 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
5557 -- Reset Pure indication if any parameter has root type System.Address
5558 -- or has any parameters of limited types, where limited means that the
5559 -- run-time view is limited (i.e. the full type is limited).
5563 procedure Expand_N_Subprogram_Body
(N
: Node_Id
) is
5564 Body_Id
: constant Entity_Id
:= Defining_Entity
(N
);
5565 HSS
: constant Node_Id
:= Handled_Statement_Sequence
(N
);
5566 Loc
: constant Source_Ptr
:= Sloc
(N
);
5568 procedure Add_Return
(Spec_Id
: Entity_Id
; Stmts
: List_Id
);
5569 -- Append a return statement to the statement sequence Stmts if the last
5570 -- statement is not already a return or a goto statement. Note that the
5571 -- latter test is not critical, it does not matter if we add a few extra
5572 -- returns, since they get eliminated anyway later on. Spec_Id denotes
5573 -- the corresponding spec of the subprogram body.
5579 procedure Add_Return
(Spec_Id
: Entity_Id
; Stmts
: List_Id
) is
5580 Last_Stmt
: Node_Id
;
5585 -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
5586 -- not relevant in this context since they are not executable.
5588 Last_Stmt
:= Last
(Stmts
);
5589 while Nkind
(Last_Stmt
) in N_Pop_xxx_Label
loop
5593 -- Now insert return unless last statement is a transfer
5595 if not Is_Transfer
(Last_Stmt
) then
5597 -- The source location for the return is the end label of the
5598 -- procedure if present. Otherwise use the sloc of the last
5599 -- statement in the list. If the list comes from a generated
5600 -- exception handler and we are not debugging generated code,
5601 -- all the statements within the handler are made invisible
5604 if Nkind
(Parent
(Stmts
)) = N_Exception_Handler
5605 and then not Comes_From_Source
(Parent
(Stmts
))
5607 Loc
:= Sloc
(Last_Stmt
);
5608 elsif Present
(End_Label
(HSS
)) then
5609 Loc
:= Sloc
(End_Label
(HSS
));
5611 Loc
:= Sloc
(Last_Stmt
);
5614 -- Append return statement, and set analyzed manually. We can't
5615 -- call Analyze on this return since the scope is wrong.
5617 -- Note: it almost works to push the scope and then do the Analyze
5618 -- call, but something goes wrong in some weird cases and it is
5619 -- not worth worrying about ???
5621 Stmt
:= Make_Simple_Return_Statement
(Loc
);
5623 -- The return statement is handled properly, and the call to the
5624 -- postcondition, inserted below, does not require information
5625 -- from the body either. However, that call is analyzed in the
5626 -- enclosing scope, and an elaboration check might improperly be
5627 -- added to it. A guard in Sem_Elab is needed to prevent that
5628 -- spurious check, see Check_Elab_Call.
5630 Append_To
(Stmts
, Stmt
);
5631 Set_Analyzed
(Stmt
);
5633 -- Call the _Postconditions procedure if the related subprogram
5634 -- has contract assertions that need to be verified on exit.
5636 if Ekind
(Spec_Id
) = E_Procedure
5637 and then Present
(Postconditions_Proc
(Spec_Id
))
5639 Insert_Action
(Stmt
,
5640 Make_Procedure_Call_Statement
(Loc
,
5642 New_Occurrence_Of
(Postconditions_Proc
(Spec_Id
), Loc
)));
5651 Spec_Id
: Entity_Id
;
5653 -- Start of processing for Expand_N_Subprogram_Body
5656 if Present
(Corresponding_Spec
(N
)) then
5657 Spec_Id
:= Corresponding_Spec
(N
);
5662 -- If this is a Pure function which has any parameters whose root type
5663 -- is System.Address, reset the Pure indication.
5664 -- This check is also performed when the subprogram is frozen, but we
5665 -- repeat it on the body so that the indication is consistent, and so
5666 -- it applies as well to bodies without separate specifications.
5668 if Is_Pure
(Spec_Id
)
5669 and then Is_Subprogram
(Spec_Id
)
5670 and then not Has_Pragma_Pure_Function
(Spec_Id
)
5672 Check_Function_With_Address_Parameter
(Spec_Id
);
5674 if Spec_Id
/= Body_Id
then
5675 Set_Is_Pure
(Body_Id
, Is_Pure
(Spec_Id
));
5679 -- Set L to either the list of declarations if present, or to the list
5680 -- of statements if no declarations are present. This is used to insert
5681 -- new stuff at the start.
5683 if Is_Non_Empty_List
(Declarations
(N
)) then
5684 L
:= Declarations
(N
);
5686 L
:= Statements
(HSS
);
5689 -- If local-exception-to-goto optimization active, insert dummy push
5690 -- statements at start, and dummy pop statements at end, but inhibit
5691 -- this if we have No_Exception_Handlers, since they are useless and
5692 -- interfere with analysis, e.g. by CodePeer. We also don't need these
5693 -- if we're unnesting subprograms because the only purpose of these
5694 -- nodes is to ensure we don't set a label in one subprogram and branch
5695 -- to it in another.
5697 if (Debug_Flag_Dot_G
5698 or else Restriction_Active
(No_Exception_Propagation
))
5699 and then not Restriction_Active
(No_Exception_Handlers
)
5700 and then not CodePeer_Mode
5701 and then not Unnest_Subprogram_Mode
5702 and then Is_Non_Empty_List
(L
)
5705 FS
: constant Node_Id
:= First
(L
);
5706 FL
: constant Source_Ptr
:= Sloc
(FS
);
5711 -- LS points to either last statement, if statements are present
5712 -- or to the last declaration if there are no statements present.
5713 -- It is the node after which the pop's are generated.
5715 if Is_Non_Empty_List
(Statements
(HSS
)) then
5716 LS
:= Last
(Statements
(HSS
));
5723 Insert_List_Before_And_Analyze
(FS
, New_List
(
5724 Make_Push_Constraint_Error_Label
(FL
),
5725 Make_Push_Program_Error_Label
(FL
),
5726 Make_Push_Storage_Error_Label
(FL
)));
5728 Insert_List_After_And_Analyze
(LS
, New_List
(
5729 Make_Pop_Constraint_Error_Label
(LL
),
5730 Make_Pop_Program_Error_Label
(LL
),
5731 Make_Pop_Storage_Error_Label
(LL
)));
5735 -- Need poll on entry to subprogram if polling enabled. We only do this
5736 -- for non-empty subprograms, since it does not seem necessary to poll
5737 -- for a dummy null subprogram.
5739 if Is_Non_Empty_List
(L
) then
5741 -- Do not add a polling call if the subprogram is to be inlined by
5742 -- the back-end, to avoid repeated calls with multiple inlinings.
5744 if Is_Inlined
(Spec_Id
)
5745 and then Front_End_Inlining
5746 and then Optimization_Level
> 1
5750 Generate_Poll_Call
(First
(L
));
5754 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
5756 if Init_Or_Norm_Scalars
and then Is_Subprogram
(Spec_Id
) then
5762 -- Loop through formals
5764 F
:= First_Formal
(Spec_Id
);
5765 while Present
(F
) loop
5766 if Is_Scalar_Type
(Etype
(F
))
5767 and then Ekind
(F
) = E_Out_Parameter
5769 Check_Restriction
(No_Default_Initialization
, F
);
5771 -- Insert the initialization. We turn off validity checks
5772 -- for this assignment, since we do not want any check on
5773 -- the initial value itself (which may well be invalid).
5774 -- Predicate checks are disabled as well (RM 6.4.1 (13/3))
5777 Make_Assignment_Statement
(Loc
,
5778 Name
=> New_Occurrence_Of
(F
, Loc
),
5779 Expression
=> Get_Simple_Init_Val
(Etype
(F
), N
));
5780 Set_Suppress_Assignment_Checks
(A
);
5782 Insert_Before_And_Analyze
(First
(L
),
5783 A
, Suppress
=> Validity_Check
);
5791 -- Clear out statement list for stubbed procedure
5793 if Present
(Corresponding_Spec
(N
)) then
5794 Set_Elaboration_Flag
(N
, Spec_Id
);
5796 if Convention
(Spec_Id
) = Convention_Stubbed
5797 or else Is_Eliminated
(Spec_Id
)
5799 Set_Declarations
(N
, Empty_List
);
5800 Set_Handled_Statement_Sequence
(N
,
5801 Make_Handled_Sequence_Of_Statements
(Loc
,
5802 Statements
=> New_List
(Make_Null_Statement
(Loc
))));
5808 -- Create a set of discriminals for the next protected subprogram body
5810 if Is_List_Member
(N
)
5811 and then Present
(Parent
(List_Containing
(N
)))
5812 and then Nkind
(Parent
(List_Containing
(N
))) = N_Protected_Body
5813 and then Present
(Next_Protected_Operation
(N
))
5815 Set_Discriminals
(Parent
(Base_Type
(Scope
(Spec_Id
))));
5818 -- Returns_By_Ref flag is normally set when the subprogram is frozen but
5819 -- subprograms with no specs are not frozen.
5822 Typ
: constant Entity_Id
:= Etype
(Spec_Id
);
5823 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
5826 if Is_Limited_View
(Typ
) then
5827 Set_Returns_By_Ref
(Spec_Id
);
5829 elsif Present
(Utyp
) and then CW_Or_Has_Controlled_Part
(Utyp
) then
5830 Set_Returns_By_Ref
(Spec_Id
);
5834 -- For a procedure, we add a return for all possible syntactic ends of
5837 if Ekind_In
(Spec_Id
, E_Procedure
, E_Generic_Procedure
) then
5838 Add_Return
(Spec_Id
, Statements
(HSS
));
5840 if Present
(Exception_Handlers
(HSS
)) then
5841 Except_H
:= First_Non_Pragma
(Exception_Handlers
(HSS
));
5842 while Present
(Except_H
) loop
5843 Add_Return
(Spec_Id
, Statements
(Except_H
));
5844 Next_Non_Pragma
(Except_H
);
5848 -- For a function, we must deal with the case where there is at least
5849 -- one missing return. What we do is to wrap the entire body of the
5850 -- function in a block:
5863 -- raise Program_Error;
5866 -- This approach is necessary because the raise must be signalled to the
5867 -- caller, not handled by any local handler (RM 6.4(11)).
5869 -- Note: we do not need to analyze the constructed sequence here, since
5870 -- it has no handler, and an attempt to analyze the handled statement
5871 -- sequence twice is risky in various ways (e.g. the issue of expanding
5872 -- cleanup actions twice).
5874 elsif Has_Missing_Return
(Spec_Id
) then
5876 Hloc
: constant Source_Ptr
:= Sloc
(HSS
);
5877 Blok
: constant Node_Id
:=
5878 Make_Block_Statement
(Hloc
,
5879 Handled_Statement_Sequence
=> HSS
);
5880 Rais
: constant Node_Id
:=
5881 Make_Raise_Program_Error
(Hloc
,
5882 Reason
=> PE_Missing_Return
);
5885 Set_Handled_Statement_Sequence
(N
,
5886 Make_Handled_Sequence_Of_Statements
(Hloc
,
5887 Statements
=> New_List
(Blok
, Rais
)));
5889 Push_Scope
(Spec_Id
);
5896 -- If subprogram contains a parameterless recursive call, then we may
5897 -- have an infinite recursion, so see if we can generate code to check
5898 -- for this possibility if storage checks are not suppressed.
5900 if Ekind
(Spec_Id
) = E_Procedure
5901 and then Has_Recursive_Call
(Spec_Id
)
5902 and then not Storage_Checks_Suppressed
(Spec_Id
)
5904 Detect_Infinite_Recursion
(N
, Spec_Id
);
5907 -- Set to encode entity names in package body before gigi is called
5909 Qualify_Entity_Names
(N
);
5911 -- If the body belongs to a nonabstract library-level source primitive
5912 -- of a tagged type, install an elaboration check which ensures that a
5913 -- dispatching call targeting the primitive will not execute the body
5914 -- without it being previously elaborated.
5916 Install_Primitive_Elaboration_Check
(N
);
5917 end Expand_N_Subprogram_Body
;
5919 -----------------------------------
5920 -- Expand_N_Subprogram_Body_Stub --
5921 -----------------------------------
5923 procedure Expand_N_Subprogram_Body_Stub
(N
: Node_Id
) is
5927 if Present
(Corresponding_Body
(N
)) then
5928 Bod
:= Unit_Declaration_Node
(Corresponding_Body
(N
));
5930 -- The body may have been expanded already when it is analyzed
5931 -- through the subunit node. Do no expand again: it interferes
5932 -- with the construction of unnesting tables when generating C.
5934 if not Analyzed
(Bod
) then
5935 Expand_N_Subprogram_Body
(Bod
);
5938 -- Add full qualification to entities that may be created late
5939 -- during unnesting.
5941 Qualify_Entity_Names
(N
);
5943 end Expand_N_Subprogram_Body_Stub
;
5945 -------------------------------------
5946 -- Expand_N_Subprogram_Declaration --
5947 -------------------------------------
5949 -- If the declaration appears within a protected body, it is a private
5950 -- operation of the protected type. We must create the corresponding
5951 -- protected subprogram an associated formals. For a normal protected
5952 -- operation, this is done when expanding the protected type declaration.
5954 -- If the declaration is for a null procedure, emit null body
5956 procedure Expand_N_Subprogram_Declaration
(N
: Node_Id
) is
5957 Loc
: constant Source_Ptr
:= Sloc
(N
);
5958 Subp
: constant Entity_Id
:= Defining_Entity
(N
);
5962 Scop
: constant Entity_Id
:= Scope
(Subp
);
5964 Prot_Decl
: Node_Id
;
5965 Prot_Id
: Entity_Id
;
5967 -- Start of processing for Expand_N_Subprogram_Declaration
5970 -- In SPARK, subprogram declarations are only allowed in package
5973 if Nkind
(Parent
(N
)) /= N_Package_Specification
then
5974 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
5975 Check_SPARK_05_Restriction
5976 ("subprogram declaration is not a library item", N
);
5978 elsif Present
(Next
(N
))
5979 and then Nkind
(Next
(N
)) = N_Pragma
5980 and then Get_Pragma_Id
(Next
(N
)) = Pragma_Import
5982 -- In SPARK, subprogram declarations are also permitted in
5983 -- declarative parts when immediately followed by a corresponding
5984 -- pragma Import. We only check here that there is some pragma
5989 Check_SPARK_05_Restriction
5990 ("subprogram declaration is not allowed here", N
);
5994 -- Deal with case of protected subprogram. Do not generate protected
5995 -- operation if operation is flagged as eliminated.
5997 if Is_List_Member
(N
)
5998 and then Present
(Parent
(List_Containing
(N
)))
5999 and then Nkind
(Parent
(List_Containing
(N
))) = N_Protected_Body
6000 and then Is_Protected_Type
(Scop
)
6002 if No
(Protected_Body_Subprogram
(Subp
))
6003 and then not Is_Eliminated
(Subp
)
6006 Make_Subprogram_Declaration
(Loc
,
6008 Build_Protected_Sub_Specification
6009 (N
, Scop
, Unprotected_Mode
));
6011 -- The protected subprogram is declared outside of the protected
6012 -- body. Given that the body has frozen all entities so far, we
6013 -- analyze the subprogram and perform freezing actions explicitly.
6014 -- including the generation of an explicit freeze node, to ensure
6015 -- that gigi has the proper order of elaboration.
6016 -- If the body is a subunit, the insertion point is before the
6017 -- stub in the parent.
6019 Prot_Bod
:= Parent
(List_Containing
(N
));
6021 if Nkind
(Parent
(Prot_Bod
)) = N_Subunit
then
6022 Prot_Bod
:= Corresponding_Stub
(Parent
(Prot_Bod
));
6025 Insert_Before
(Prot_Bod
, Prot_Decl
);
6026 Prot_Id
:= Defining_Unit_Name
(Specification
(Prot_Decl
));
6027 Set_Has_Delayed_Freeze
(Prot_Id
);
6029 Push_Scope
(Scope
(Scop
));
6030 Analyze
(Prot_Decl
);
6031 Freeze_Before
(N
, Prot_Id
);
6032 Set_Protected_Body_Subprogram
(Subp
, Prot_Id
);
6034 -- Create protected operation as well. Even though the operation
6035 -- is only accessible within the body, it is possible to make it
6036 -- available outside of the protected object by using 'Access to
6037 -- provide a callback, so build protected version in all cases.
6040 Make_Subprogram_Declaration
(Loc
,
6042 Build_Protected_Sub_Specification
(N
, Scop
, Protected_Mode
));
6043 Insert_Before
(Prot_Bod
, Prot_Decl
);
6044 Analyze
(Prot_Decl
);
6049 -- Ada 2005 (AI-348): Generate body for a null procedure. In most
6050 -- cases this is superfluous because calls to it will be automatically
6051 -- inlined, but we definitely need the body if preconditions for the
6052 -- procedure are present, or if performing coverage analysis.
6054 elsif Nkind
(Specification
(N
)) = N_Procedure_Specification
6055 and then Null_Present
(Specification
(N
))
6058 Bod
: constant Node_Id
:= Body_To_Inline
(N
);
6061 Set_Has_Completion
(Subp
, False);
6062 Append_Freeze_Action
(Subp
, Bod
);
6064 -- The body now contains raise statements, so calls to it will
6067 Set_Is_Inlined
(Subp
, False);
6071 -- When generating C code, transform a function that returns a
6072 -- constrained array type into a procedure with an out parameter
6073 -- that carries the return value.
6075 -- We skip this transformation for unchecked conversions, since they
6076 -- are not needed by the C generator (and this also produces cleaner
6079 if Modify_Tree_For_C
6080 and then Nkind
(Specification
(N
)) = N_Function_Specification
6081 and then Is_Array_Type
(Etype
(Subp
))
6082 and then Is_Constrained
(Etype
(Subp
))
6083 and then not Is_Unchecked_Conversion_Instance
(Subp
)
6085 Build_Procedure_Form
(N
);
6087 end Expand_N_Subprogram_Declaration
;
6089 --------------------------------
6090 -- Expand_Non_Function_Return --
6091 --------------------------------
6093 procedure Expand_Non_Function_Return
(N
: Node_Id
) is
6094 pragma Assert
(No
(Expression
(N
)));
6096 Loc
: constant Source_Ptr
:= Sloc
(N
);
6097 Scope_Id
: Entity_Id
:= Return_Applies_To
(Return_Statement_Entity
(N
));
6098 Kind
: constant Entity_Kind
:= Ekind
(Scope_Id
);
6101 Goto_Stat
: Node_Id
;
6105 -- Call the _Postconditions procedure if the related subprogram has
6106 -- contract assertions that need to be verified on exit.
6108 if Ekind_In
(Scope_Id
, E_Entry
, E_Entry_Family
, E_Procedure
)
6109 and then Present
(Postconditions_Proc
(Scope_Id
))
6112 Make_Procedure_Call_Statement
(Loc
,
6113 Name
=> New_Occurrence_Of
(Postconditions_Proc
(Scope_Id
), Loc
)));
6116 -- If it is a return from a procedure do no extra steps
6118 if Kind
= E_Procedure
or else Kind
= E_Generic_Procedure
then
6121 -- If it is a nested return within an extended one, replace it with a
6122 -- return of the previously declared return object.
6124 elsif Kind
= E_Return_Statement
then
6126 Make_Simple_Return_Statement
(Loc
,
6128 New_Occurrence_Of
(First_Entity
(Scope_Id
), Loc
)));
6129 Set_Comes_From_Extended_Return_Statement
(N
);
6130 Set_Return_Statement_Entity
(N
, Scope_Id
);
6131 Expand_Simple_Function_Return
(N
);
6135 pragma Assert
(Is_Entry
(Scope_Id
));
6137 -- Look at the enclosing block to see whether the return is from an
6138 -- accept statement or an entry body.
6140 for J
in reverse 0 .. Scope_Stack
.Last
loop
6141 Scope_Id
:= Scope_Stack
.Table
(J
).Entity
;
6142 exit when Is_Concurrent_Type
(Scope_Id
);
6145 -- If it is a return from accept statement it is expanded as call to
6146 -- RTS Complete_Rendezvous and a goto to the end of the accept body.
6148 -- (cf : Expand_N_Accept_Statement, Expand_N_Selective_Accept,
6149 -- Expand_N_Accept_Alternative in exp_ch9.adb)
6151 if Is_Task_Type
(Scope_Id
) then
6154 Make_Procedure_Call_Statement
(Loc
,
6155 Name
=> New_Occurrence_Of
(RTE
(RE_Complete_Rendezvous
), Loc
));
6156 Insert_Before
(N
, Call
);
6157 -- why not insert actions here???
6160 Acc_Stat
:= Parent
(N
);
6161 while Nkind
(Acc_Stat
) /= N_Accept_Statement
loop
6162 Acc_Stat
:= Parent
(Acc_Stat
);
6165 Lab_Node
:= Last
(Statements
6166 (Handled_Statement_Sequence
(Acc_Stat
)));
6168 Goto_Stat
:= Make_Goto_Statement
(Loc
,
6169 Name
=> New_Occurrence_Of
6170 (Entity
(Identifier
(Lab_Node
)), Loc
));
6172 Set_Analyzed
(Goto_Stat
);
6174 Rewrite
(N
, Goto_Stat
);
6177 -- If it is a return from an entry body, put a Complete_Entry_Body call
6178 -- in front of the return.
6180 elsif Is_Protected_Type
(Scope_Id
) then
6182 Make_Procedure_Call_Statement
(Loc
,
6184 New_Occurrence_Of
(RTE
(RE_Complete_Entry_Body
), Loc
),
6185 Parameter_Associations
=> New_List
(
6186 Make_Attribute_Reference
(Loc
,
6189 (Find_Protection_Object
(Current_Scope
), Loc
),
6190 Attribute_Name
=> Name_Unchecked_Access
)));
6192 Insert_Before
(N
, Call
);
6195 end Expand_Non_Function_Return
;
6197 ---------------------------------------
6198 -- Expand_Protected_Object_Reference --
6199 ---------------------------------------
6201 function Expand_Protected_Object_Reference
6203 Scop
: Entity_Id
) return Node_Id
6205 Loc
: constant Source_Ptr
:= Sloc
(N
);
6212 Rec
:= Make_Identifier
(Loc
, Name_uObject
);
6213 Set_Etype
(Rec
, Corresponding_Record_Type
(Scop
));
6215 -- Find enclosing protected operation, and retrieve its first parameter,
6216 -- which denotes the enclosing protected object. If the enclosing
6217 -- operation is an entry, we are immediately within the protected body,
6218 -- and we can retrieve the object from the service entries procedure. A
6219 -- barrier function has the same signature as an entry. A barrier
6220 -- function is compiled within the protected object, but unlike
6221 -- protected operations its never needs locks, so that its protected
6222 -- body subprogram points to itself.
6224 Proc
:= Current_Scope
;
6225 while Present
(Proc
)
6226 and then Scope
(Proc
) /= Scop
6228 Proc
:= Scope
(Proc
);
6231 Corr
:= Protected_Body_Subprogram
(Proc
);
6235 -- Previous error left expansion incomplete.
6236 -- Nothing to do on this call.
6243 (First
(Parameter_Specifications
(Parent
(Corr
))));
6245 if Is_Subprogram
(Proc
) and then Proc
/= Corr
then
6247 -- Protected function or procedure
6249 Set_Entity
(Rec
, Param
);
6251 -- Rec is a reference to an entity which will not be in scope when
6252 -- the call is reanalyzed, and needs no further analysis.
6257 -- Entry or barrier function for entry body. The first parameter of
6258 -- the entry body procedure is pointer to the object. We create a
6259 -- local variable of the proper type, duplicating what is done to
6260 -- define _object later on.
6264 Obj_Ptr
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
6268 Make_Full_Type_Declaration
(Loc
,
6269 Defining_Identifier
=> Obj_Ptr
,
6271 Make_Access_To_Object_Definition
(Loc
,
6272 Subtype_Indication
=>
6274 (Corresponding_Record_Type
(Scop
), Loc
))));
6276 Insert_Actions
(N
, Decls
);
6277 Freeze_Before
(N
, Obj_Ptr
);
6280 Make_Explicit_Dereference
(Loc
,
6282 Unchecked_Convert_To
(Obj_Ptr
,
6283 New_Occurrence_Of
(Param
, Loc
)));
6285 -- Analyze new actual. Other actuals in calls are already analyzed
6286 -- and the list of actuals is not reanalyzed after rewriting.
6288 Set_Parent
(Rec
, N
);
6294 end Expand_Protected_Object_Reference
;
6296 --------------------------------------
6297 -- Expand_Protected_Subprogram_Call --
6298 --------------------------------------
6300 procedure Expand_Protected_Subprogram_Call
6307 procedure Expand_Internal_Init_Call
;
6308 -- A call to an operation of the type may occur in the initialization
6309 -- of a private component. In that case the prefix of the call is an
6310 -- entity name and the call is treated as internal even though it
6311 -- appears in code outside of the protected type.
6313 procedure Freeze_Called_Function
;
6314 -- If it is a function call it can appear in elaboration code and
6315 -- the called entity must be frozen before the call. This must be
6316 -- done before the call is expanded, as the expansion may rewrite it
6317 -- to something other than a call (e.g. a temporary initialized in a
6318 -- transient block).
6320 -------------------------------
6321 -- Expand_Internal_Init_Call --
6322 -------------------------------
6324 procedure Expand_Internal_Init_Call
is
6326 -- If the context is a protected object (rather than a protected
6327 -- type) the call itself is bound to raise program_error because
6328 -- the protected body will not have been elaborated yet. This is
6329 -- diagnosed subsequently in Sem_Elab.
6331 Freeze_Called_Function
;
6333 -- The target of the internal call is the first formal of the
6334 -- enclosing initialization procedure.
6336 Rec
:= New_Occurrence_Of
(First_Formal
(Current_Scope
), Sloc
(N
));
6337 Build_Protected_Subprogram_Call
(N
,
6342 Resolve
(N
, Etype
(Subp
));
6343 end Expand_Internal_Init_Call
;
6345 ----------------------------
6346 -- Freeze_Called_Function --
6347 ----------------------------
6349 procedure Freeze_Called_Function
is
6351 if Ekind
(Subp
) = E_Function
then
6352 Freeze_Expression
(Name
(N
));
6354 end Freeze_Called_Function
;
6356 -- Start of processing for Expand_Protected_Subprogram_Call
6359 -- If the protected object is not an enclosing scope, this is an inter-
6360 -- object function call. Inter-object procedure calls are expanded by
6361 -- Exp_Ch9.Build_Simple_Entry_Call. The call is intra-object only if the
6362 -- subprogram being called is in the protected body being compiled, and
6363 -- if the protected object in the call is statically the enclosing type.
6364 -- The object may be a component of some other data structure, in which
6365 -- case this must be handled as an inter-object call.
6367 if not In_Open_Scopes
(Scop
)
6368 or else Is_Entry_Wrapper
(Current_Scope
)
6369 or else not Is_Entity_Name
(Name
(N
))
6371 if Nkind
(Name
(N
)) = N_Selected_Component
then
6372 Rec
:= Prefix
(Name
(N
));
6374 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
6375 Rec
:= Prefix
(Prefix
(Name
(N
)));
6377 -- If this is a call within an entry wrapper, it appears within a
6378 -- precondition that calls another primitive of the synchronized
6379 -- type. The target object of the call is the first actual on the
6380 -- wrapper. Note that this is an external call, because the wrapper
6381 -- is called outside of the synchronized object. This means that
6382 -- an entry call to an entry with preconditions involves two
6383 -- synchronized operations.
6385 elsif Ekind
(Current_Scope
) = E_Procedure
6386 and then Is_Entry_Wrapper
(Current_Scope
)
6388 Rec
:= New_Occurrence_Of
(First_Entity
(Current_Scope
), Sloc
(N
));
6391 -- If the context is the initialization procedure for a protected
6392 -- type, the call is legal because the called entity must be a
6393 -- function of that enclosing type, and this is treated as an
6397 (Is_Entity_Name
(Name
(N
)) and then Inside_Init_Proc
);
6399 Expand_Internal_Init_Call
;
6403 Freeze_Called_Function
;
6404 Build_Protected_Subprogram_Call
(N
,
6405 Name
=> New_Occurrence_Of
(Subp
, Sloc
(N
)),
6406 Rec
=> Convert_Concurrent
(Rec
, Etype
(Rec
)),
6410 Rec
:= Expand_Protected_Object_Reference
(N
, Scop
);
6416 Freeze_Called_Function
;
6417 Build_Protected_Subprogram_Call
(N
,
6423 -- Analyze and resolve the new call. The actuals have already been
6424 -- resolved, but expansion of a function call will add extra actuals
6425 -- if needed. Analysis of a procedure call already includes resolution.
6429 if Ekind
(Subp
) = E_Function
then
6430 Resolve
(N
, Etype
(Subp
));
6432 end Expand_Protected_Subprogram_Call
;
6434 -----------------------------------
6435 -- Expand_Simple_Function_Return --
6436 -----------------------------------
6438 -- The "simple" comes from the syntax rule simple_return_statement. The
6439 -- semantics are not at all simple.
6441 procedure Expand_Simple_Function_Return
(N
: Node_Id
) is
6442 Loc
: constant Source_Ptr
:= Sloc
(N
);
6444 Scope_Id
: constant Entity_Id
:=
6445 Return_Applies_To
(Return_Statement_Entity
(N
));
6446 -- The function we are returning from
6448 R_Type
: constant Entity_Id
:= Etype
(Scope_Id
);
6449 -- The result type of the function
6451 Utyp
: constant Entity_Id
:= Underlying_Type
(R_Type
);
6453 Exp
: Node_Id
:= Expression
(N
);
6454 pragma Assert
(Present
(Exp
));
6456 Exptyp
: constant Entity_Id
:= Etype
(Exp
);
6457 -- The type of the expression (not necessarily the same as R_Type)
6459 Subtype_Ind
: Node_Id
;
6460 -- If the result type of the function is class-wide and the expression
6461 -- has a specific type, then we use the expression's type as the type of
6462 -- the return object. In cases where the expression is an aggregate that
6463 -- is built in place, this avoids the need for an expensive conversion
6464 -- of the return object to the specific type on assignments to the
6465 -- individual components.
6468 if Is_Class_Wide_Type
(R_Type
)
6469 and then not Is_Class_Wide_Type
(Exptyp
)
6470 and then Nkind
(Exp
) /= N_Type_Conversion
6472 Subtype_Ind
:= New_Occurrence_Of
(Exptyp
, Loc
);
6474 Subtype_Ind
:= New_Occurrence_Of
(R_Type
, Loc
);
6476 -- If the result type is class-wide and the expression is a view
6477 -- conversion, the conversion plays no role in the expansion because
6478 -- it does not modify the tag of the object. Remove the conversion
6479 -- altogether to prevent tag overwriting.
6481 if Is_Class_Wide_Type
(R_Type
)
6482 and then not Is_Class_Wide_Type
(Exptyp
)
6483 and then Nkind
(Exp
) = N_Type_Conversion
6485 Exp
:= Expression
(Exp
);
6489 -- Assert that if F says "return G(...);"
6490 -- then F and G are both b-i-p, or neither b-i-p.
6492 if Nkind
(Exp
) = N_Function_Call
then
6493 pragma Assert
(Ekind
(Scope_Id
) = E_Function
);
6495 (Is_Build_In_Place_Function
(Scope_Id
) =
6496 Is_Build_In_Place_Function_Call
(Exp
));
6500 -- For the case of a simple return that does not come from an
6501 -- extended return, in the case of build-in-place, we rewrite
6502 -- "return <expression>;" to be:
6504 -- return _anon_ : <return_subtype> := <expression>
6506 -- The expansion produced by Expand_N_Extended_Return_Statement will
6507 -- contain simple return statements (for example, a block containing
6508 -- simple return of the return object), which brings us back here with
6509 -- Comes_From_Extended_Return_Statement set. The reason for the barrier
6510 -- checking for a simple return that does not come from an extended
6511 -- return is to avoid this infinite recursion.
6513 -- The reason for this design is that for Ada 2005 limited returns, we
6514 -- need to reify the return object, so we can build it "in place", and
6515 -- we need a block statement to hang finalization and tasking stuff.
6517 -- ??? In order to avoid disruption, we avoid translating to extended
6518 -- return except in the cases where we really need to (Ada 2005 for
6519 -- inherently limited). We might prefer to do this translation in all
6520 -- cases (except perhaps for the case of Ada 95 inherently limited),
6521 -- in order to fully exercise the Expand_N_Extended_Return_Statement
6522 -- code. This would also allow us to do the build-in-place optimization
6523 -- for efficiency even in cases where it is semantically not required.
6525 -- As before, we check the type of the return expression rather than the
6526 -- return type of the function, because the latter may be a limited
6527 -- class-wide interface type, which is not a limited type, even though
6528 -- the type of the expression may be.
6531 (Comes_From_Extended_Return_Statement
(N
)
6532 or else not Is_Build_In_Place_Function_Call
(Exp
)
6533 or else Is_Build_In_Place_Function
(Scope_Id
));
6535 if not Comes_From_Extended_Return_Statement
(N
)
6536 and then Is_Build_In_Place_Function
(Scope_Id
)
6537 and then not Debug_Flag_Dot_L
6539 -- The functionality of interface thunks is simple and it is always
6540 -- handled by means of simple return statements. This leaves their
6541 -- expansion simple and clean.
6543 and then not Is_Thunk
(Current_Scope
)
6546 Return_Object_Entity
: constant Entity_Id
:=
6547 Make_Temporary
(Loc
, 'R', Exp
);
6549 Obj_Decl
: constant Node_Id
:=
6550 Make_Object_Declaration
(Loc
,
6551 Defining_Identifier
=> Return_Object_Entity
,
6552 Object_Definition
=> Subtype_Ind
,
6555 Ext
: constant Node_Id
:=
6556 Make_Extended_Return_Statement
(Loc
,
6557 Return_Object_Declarations
=> New_List
(Obj_Decl
));
6558 -- Do not perform this high-level optimization if the result type
6559 -- is an interface because the "this" pointer must be displaced.
6568 -- Here we have a simple return statement that is part of the expansion
6569 -- of an extended return statement (either written by the user, or
6570 -- generated by the above code).
6572 -- Always normalize C/Fortran boolean result. This is not always needed,
6573 -- but it seems a good idea to minimize the passing around of non-
6574 -- normalized values, and in any case this handles the processing of
6575 -- barrier functions for protected types, which turn the condition into
6576 -- a return statement.
6578 if Is_Boolean_Type
(Exptyp
)
6579 and then Nonzero_Is_True
(Exptyp
)
6581 Adjust_Condition
(Exp
);
6582 Adjust_Result_Type
(Exp
, Exptyp
);
6585 -- Do validity check if enabled for returns
6587 if Validity_Checks_On
6588 and then Validity_Check_Returns
6593 -- Check the result expression of a scalar function against the subtype
6594 -- of the function by inserting a conversion. This conversion must
6595 -- eventually be performed for other classes of types, but for now it's
6596 -- only done for scalars.
6599 if Is_Scalar_Type
(Exptyp
) then
6600 Rewrite
(Exp
, Convert_To
(R_Type
, Exp
));
6602 -- The expression is resolved to ensure that the conversion gets
6603 -- expanded to generate a possible constraint check.
6605 Analyze_And_Resolve
(Exp
, R_Type
);
6608 -- Deal with returning variable length objects and controlled types
6610 -- Nothing to do if we are returning by reference, or this is not a
6611 -- type that requires special processing (indicated by the fact that
6612 -- it requires a cleanup scope for the secondary stack case).
6614 if Is_Build_In_Place_Function
(Scope_Id
)
6615 or else Is_Limited_Interface
(Exptyp
)
6619 -- No copy needed for thunks returning interface type objects since
6620 -- the object is returned by reference and the maximum functionality
6621 -- required is just to displace the pointer.
6623 elsif Is_Thunk
(Current_Scope
) and then Is_Interface
(Exptyp
) then
6626 -- If the call is within a thunk and the type is a limited view, the
6627 -- backend will eventually see the non-limited view of the type.
6629 elsif Is_Thunk
(Current_Scope
) and then Is_Incomplete_Type
(Exptyp
) then
6632 elsif not Requires_Transient_Scope
(R_Type
) then
6634 -- Mutable records with variable-length components are not returned
6635 -- on the sec-stack, so we need to make sure that the back end will
6636 -- only copy back the size of the actual value, and not the maximum
6637 -- size. We create an actual subtype for this purpose. However we
6638 -- need not do it if the expression is a function call since this
6639 -- will be done in the called function and doing it here too would
6640 -- cause a temporary with maximum size to be created.
6643 Ubt
: constant Entity_Id
:= Underlying_Type
(Base_Type
(Exptyp
));
6647 if Nkind
(Exp
) /= N_Function_Call
6648 and then Has_Discriminants
(Ubt
)
6649 and then not Is_Constrained
(Ubt
)
6650 and then not Has_Unchecked_Union
(Ubt
)
6652 Decl
:= Build_Actual_Subtype
(Ubt
, Exp
);
6653 Ent
:= Defining_Identifier
(Decl
);
6654 Insert_Action
(Exp
, Decl
);
6655 Rewrite
(Exp
, Unchecked_Convert_To
(Ent
, Exp
));
6656 Analyze_And_Resolve
(Exp
);
6660 -- Here if secondary stack is used
6663 -- Prevent the reclamation of the secondary stack by all enclosing
6664 -- blocks and loops as well as the related function; otherwise the
6665 -- result would be reclaimed too early.
6667 Set_Enclosing_Sec_Stack_Return
(N
);
6669 -- Optimize the case where the result is a function call. In this
6670 -- case either the result is already on the secondary stack, or is
6671 -- already being returned with the stack pointer depressed and no
6672 -- further processing is required except to set the By_Ref flag
6673 -- to ensure that gigi does not attempt an extra unnecessary copy.
6674 -- (actually not just unnecessary but harmfully wrong in the case
6675 -- of a controlled type, where gigi does not know how to do a copy).
6676 -- To make up for a gcc 2.8.1 deficiency (???), we perform the copy
6677 -- for array types if the constrained status of the target type is
6678 -- different from that of the expression.
6680 if Requires_Transient_Scope
(Exptyp
)
6682 (not Is_Array_Type
(Exptyp
)
6683 or else Is_Constrained
(Exptyp
) = Is_Constrained
(R_Type
)
6684 or else CW_Or_Has_Controlled_Part
(Utyp
))
6685 and then Nkind
(Exp
) = N_Function_Call
6689 -- Remove side effects from the expression now so that other parts
6690 -- of the expander do not have to reanalyze this node without this
6693 Rewrite
(Exp
, Duplicate_Subexpr_No_Checks
(Exp
));
6695 -- Ada 2005 (AI-251): If the type of the returned object is
6696 -- an interface then add an implicit type conversion to force
6697 -- displacement of the "this" pointer.
6699 if Is_Interface
(R_Type
) then
6700 Rewrite
(Exp
, Convert_To
(R_Type
, Relocate_Node
(Exp
)));
6703 Analyze_And_Resolve
(Exp
, R_Type
);
6705 -- For controlled types, do the allocation on the secondary stack
6706 -- manually in order to call adjust at the right time:
6708 -- type Anon1 is access R_Type;
6709 -- for Anon1'Storage_pool use ss_pool;
6710 -- Anon2 : anon1 := new R_Type'(expr);
6711 -- return Anon2.all;
6713 -- We do the same for classwide types that are not potentially
6714 -- controlled (by the virtue of restriction No_Finalization) because
6715 -- gigi is not able to properly allocate class-wide types.
6717 elsif CW_Or_Has_Controlled_Part
(Utyp
) then
6719 Loc
: constant Source_Ptr
:= Sloc
(N
);
6720 Acc_Typ
: constant Entity_Id
:= Make_Temporary
(Loc
, 'A');
6721 Alloc_Node
: Node_Id
;
6725 Set_Ekind
(Acc_Typ
, E_Access_Type
);
6727 Set_Associated_Storage_Pool
(Acc_Typ
, RTE
(RE_SS_Pool
));
6729 -- This is an allocator for the secondary stack, and it's fine
6730 -- to have Comes_From_Source set False on it, as gigi knows not
6731 -- to flag it as a violation of No_Implicit_Heap_Allocations.
6734 Make_Allocator
(Loc
,
6736 Make_Qualified_Expression
(Loc
,
6737 Subtype_Mark
=> New_Occurrence_Of
(Etype
(Exp
), Loc
),
6738 Expression
=> Relocate_Node
(Exp
)));
6740 -- We do not want discriminant checks on the declaration,
6741 -- given that it gets its value from the allocator.
6743 Set_No_Initialization
(Alloc_Node
);
6745 Temp
:= Make_Temporary
(Loc
, 'R', Alloc_Node
);
6747 Insert_List_Before_And_Analyze
(N
, New_List
(
6748 Make_Full_Type_Declaration
(Loc
,
6749 Defining_Identifier
=> Acc_Typ
,
6751 Make_Access_To_Object_Definition
(Loc
,
6752 Subtype_Indication
=> Subtype_Ind
)),
6754 Make_Object_Declaration
(Loc
,
6755 Defining_Identifier
=> Temp
,
6756 Object_Definition
=> New_Occurrence_Of
(Acc_Typ
, Loc
),
6757 Expression
=> Alloc_Node
)));
6760 Make_Explicit_Dereference
(Loc
,
6761 Prefix
=> New_Occurrence_Of
(Temp
, Loc
)));
6763 -- Ada 2005 (AI-251): If the type of the returned object is
6764 -- an interface then add an implicit type conversion to force
6765 -- displacement of the "this" pointer.
6767 if Is_Interface
(R_Type
) then
6768 Rewrite
(Exp
, Convert_To
(R_Type
, Relocate_Node
(Exp
)));
6771 Analyze_And_Resolve
(Exp
, R_Type
);
6774 -- Otherwise use the gigi mechanism to allocate result on the
6778 Check_Restriction
(No_Secondary_Stack
, N
);
6779 Set_Storage_Pool
(N
, RTE
(RE_SS_Pool
));
6780 Set_Procedure_To_Call
(N
, RTE
(RE_SS_Allocate
));
6784 -- Implement the rules of 6.5(8-10), which require a tag check in
6785 -- the case of a limited tagged return type, and tag reassignment for
6786 -- nonlimited tagged results. These actions are needed when the return
6787 -- type is a specific tagged type and the result expression is a
6788 -- conversion or a formal parameter, because in that case the tag of
6789 -- the expression might differ from the tag of the specific result type.
6791 -- We must also verify an underlying type exists for the return type in
6792 -- case it is incomplete - in which case is not necessary to generate a
6793 -- check anyway since an incomplete limited tagged return type would
6794 -- qualify as a premature usage.
6797 and then Is_Tagged_Type
(Utyp
)
6798 and then not Is_Class_Wide_Type
(Utyp
)
6799 and then (Nkind_In
(Exp
, N_Type_Conversion
,
6800 N_Unchecked_Type_Conversion
)
6801 or else (Is_Entity_Name
(Exp
)
6802 and then Ekind
(Entity
(Exp
)) in Formal_Kind
))
6804 -- When the return type is limited, perform a check that the tag of
6805 -- the result is the same as the tag of the return type.
6807 if Is_Limited_Type
(R_Type
) then
6809 Make_Raise_Constraint_Error
(Loc
,
6813 Make_Selected_Component
(Loc
,
6814 Prefix
=> Duplicate_Subexpr
(Exp
),
6815 Selector_Name
=> Make_Identifier
(Loc
, Name_uTag
)),
6817 Make_Attribute_Reference
(Loc
,
6819 New_Occurrence_Of
(Base_Type
(Utyp
), Loc
),
6820 Attribute_Name
=> Name_Tag
)),
6821 Reason
=> CE_Tag_Check_Failed
));
6823 -- If the result type is a specific nonlimited tagged type, then we
6824 -- have to ensure that the tag of the result is that of the result
6825 -- type. This is handled by making a copy of the expression in
6826 -- the case where it might have a different tag, namely when the
6827 -- expression is a conversion or a formal parameter. We create a new
6828 -- object of the result type and initialize it from the expression,
6829 -- which will implicitly force the tag to be set appropriately.
6833 ExpR
: constant Node_Id
:= Relocate_Node
(Exp
);
6834 Result_Id
: constant Entity_Id
:=
6835 Make_Temporary
(Loc
, 'R', ExpR
);
6836 Result_Exp
: constant Node_Id
:=
6837 New_Occurrence_Of
(Result_Id
, Loc
);
6838 Result_Obj
: constant Node_Id
:=
6839 Make_Object_Declaration
(Loc
,
6840 Defining_Identifier
=> Result_Id
,
6841 Object_Definition
=>
6842 New_Occurrence_Of
(R_Type
, Loc
),
6843 Constant_Present
=> True,
6844 Expression
=> ExpR
);
6847 Set_Assignment_OK
(Result_Obj
);
6848 Insert_Action
(Exp
, Result_Obj
);
6850 Rewrite
(Exp
, Result_Exp
);
6851 Analyze_And_Resolve
(Exp
, R_Type
);
6855 -- Ada 2005 (AI-344): If the result type is class-wide, then insert
6856 -- a check that the level of the return expression's underlying type
6857 -- is not deeper than the level of the master enclosing the function.
6858 -- Always generate the check when the type of the return expression
6859 -- is class-wide, when it's a type conversion, or when it's a formal
6860 -- parameter. Otherwise, suppress the check in the case where the
6861 -- return expression has a specific type whose level is known not to
6862 -- be statically deeper than the function's result type.
6864 -- No runtime check needed in interface thunks since it is performed
6865 -- by the target primitive associated with the thunk.
6867 -- Note: accessibility check is skipped in the VM case, since there
6868 -- does not seem to be any practical way to implement this check.
6870 elsif Ada_Version
>= Ada_2005
6871 and then Tagged_Type_Expansion
6872 and then Is_Class_Wide_Type
(R_Type
)
6873 and then not Is_Thunk
(Current_Scope
)
6874 and then not Scope_Suppress
.Suppress
(Accessibility_Check
)
6876 (Is_Class_Wide_Type
(Etype
(Exp
))
6877 or else Nkind_In
(Exp
, N_Type_Conversion
,
6878 N_Unchecked_Type_Conversion
)
6879 or else (Is_Entity_Name
(Exp
)
6880 and then Ekind
(Entity
(Exp
)) in Formal_Kind
)
6881 or else Scope_Depth
(Enclosing_Dynamic_Scope
(Etype
(Exp
))) >
6882 Scope_Depth
(Enclosing_Dynamic_Scope
(Scope_Id
)))
6888 -- Ada 2005 (AI-251): In class-wide interface objects we displace
6889 -- "this" to reference the base of the object. This is required to
6890 -- get access to the TSD of the object.
6892 if Is_Class_Wide_Type
(Etype
(Exp
))
6893 and then Is_Interface
(Etype
(Exp
))
6895 -- If the expression is an explicit dereference then we can
6896 -- directly displace the pointer to reference the base of
6899 if Nkind
(Exp
) = N_Explicit_Dereference
then
6901 Make_Explicit_Dereference
(Loc
,
6903 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6904 Make_Function_Call
(Loc
,
6906 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6907 Parameter_Associations
=> New_List
(
6908 Unchecked_Convert_To
(RTE
(RE_Address
),
6909 Duplicate_Subexpr
(Prefix
(Exp
)))))));
6911 -- Similar case to the previous one but the expression is a
6912 -- renaming of an explicit dereference.
6914 elsif Nkind
(Exp
) = N_Identifier
6915 and then Present
(Renamed_Object
(Entity
(Exp
)))
6916 and then Nkind
(Renamed_Object
(Entity
(Exp
)))
6917 = N_Explicit_Dereference
6920 Make_Explicit_Dereference
(Loc
,
6922 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6923 Make_Function_Call
(Loc
,
6925 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6926 Parameter_Associations
=> New_List
(
6927 Unchecked_Convert_To
(RTE
(RE_Address
),
6930 (Renamed_Object
(Entity
(Exp
)))))))));
6932 -- Common case: obtain the address of the actual object and
6933 -- displace the pointer to reference the base of the object.
6937 Make_Explicit_Dereference
(Loc
,
6939 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6940 Make_Function_Call
(Loc
,
6942 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6943 Parameter_Associations
=> New_List
(
6944 Make_Attribute_Reference
(Loc
,
6945 Prefix
=> Duplicate_Subexpr
(Exp
),
6946 Attribute_Name
=> Name_Address
)))));
6950 Make_Attribute_Reference
(Loc
,
6951 Prefix
=> Duplicate_Subexpr
(Exp
),
6952 Attribute_Name
=> Name_Tag
);
6955 -- CodePeer does not do anything useful with
6956 -- Ada.Tags.Type_Specific_Data components.
6958 if not CodePeer_Mode
then
6960 Make_Raise_Program_Error
(Loc
,
6963 Left_Opnd
=> Build_Get_Access_Level
(Loc
, Tag_Node
),
6965 Make_Integer_Literal
(Loc
,
6966 Scope_Depth
(Enclosing_Dynamic_Scope
(Scope_Id
)))),
6967 Reason
=> PE_Accessibility_Check_Failed
));
6971 -- AI05-0073: If function has a controlling access result, check that
6972 -- the tag of the return value, if it is not null, matches designated
6973 -- type of return type.
6975 -- The return expression is referenced twice in the code below, so it
6976 -- must be made free of side effects. Given that different compilers
6977 -- may evaluate these parameters in different order, both occurrences
6980 elsif Ekind
(R_Type
) = E_Anonymous_Access_Type
6981 and then Has_Controlling_Result
(Scope_Id
)
6984 Make_Raise_Constraint_Error
(Loc
,
6989 Left_Opnd
=> Duplicate_Subexpr
(Exp
),
6990 Right_Opnd
=> Make_Null
(Loc
)),
6992 Right_Opnd
=> Make_Op_Ne
(Loc
,
6994 Make_Selected_Component
(Loc
,
6995 Prefix
=> Duplicate_Subexpr
(Exp
),
6996 Selector_Name
=> Make_Identifier
(Loc
, Name_uTag
)),
6999 Make_Attribute_Reference
(Loc
,
7001 New_Occurrence_Of
(Designated_Type
(R_Type
), Loc
),
7002 Attribute_Name
=> Name_Tag
))),
7004 Reason
=> CE_Tag_Check_Failed
),
7005 Suppress
=> All_Checks
);
7008 -- AI05-0234: RM 6.5(21/3). Check access discriminants to
7009 -- ensure that the function result does not outlive an
7010 -- object designated by one of it discriminants.
7012 if Present
(Extra_Accessibility_Of_Result
(Scope_Id
))
7013 and then Has_Unconstrained_Access_Discriminants
(R_Type
)
7016 Discrim_Source
: Node_Id
;
7018 procedure Check_Against_Result_Level
(Level
: Node_Id
);
7019 -- Check the given accessibility level against the level
7020 -- determined by the point of call. (AI05-0234).
7022 --------------------------------
7023 -- Check_Against_Result_Level --
7024 --------------------------------
7026 procedure Check_Against_Result_Level
(Level
: Node_Id
) is
7029 Make_Raise_Program_Error
(Loc
,
7035 (Extra_Accessibility_Of_Result
(Scope_Id
), Loc
)),
7036 Reason
=> PE_Accessibility_Check_Failed
));
7037 end Check_Against_Result_Level
;
7040 Discrim_Source
:= Exp
;
7041 while Nkind
(Discrim_Source
) = N_Qualified_Expression
loop
7042 Discrim_Source
:= Expression
(Discrim_Source
);
7045 if Nkind
(Discrim_Source
) = N_Identifier
7046 and then Is_Return_Object
(Entity
(Discrim_Source
))
7048 Discrim_Source
:= Entity
(Discrim_Source
);
7050 if Is_Constrained
(Etype
(Discrim_Source
)) then
7051 Discrim_Source
:= Etype
(Discrim_Source
);
7053 Discrim_Source
:= Expression
(Parent
(Discrim_Source
));
7056 elsif Nkind
(Discrim_Source
) = N_Identifier
7057 and then Nkind_In
(Original_Node
(Discrim_Source
),
7058 N_Aggregate
, N_Extension_Aggregate
)
7060 Discrim_Source
:= Original_Node
(Discrim_Source
);
7062 elsif Nkind
(Discrim_Source
) = N_Explicit_Dereference
and then
7063 Nkind
(Original_Node
(Discrim_Source
)) = N_Function_Call
7065 Discrim_Source
:= Original_Node
(Discrim_Source
);
7068 Discrim_Source
:= Unqual_Conv
(Discrim_Source
);
7070 case Nkind
(Discrim_Source
) is
7071 when N_Defining_Identifier
=>
7072 pragma Assert
(Is_Composite_Type
(Discrim_Source
)
7073 and then Has_Discriminants
(Discrim_Source
)
7074 and then Is_Constrained
(Discrim_Source
));
7077 Discrim
: Entity_Id
:=
7078 First_Discriminant
(Base_Type
(R_Type
));
7079 Disc_Elmt
: Elmt_Id
:=
7080 First_Elmt
(Discriminant_Constraint
7084 if Ekind
(Etype
(Discrim
)) =
7085 E_Anonymous_Access_Type
7087 Check_Against_Result_Level
7088 (Dynamic_Accessibility_Level
(Node
(Disc_Elmt
)));
7091 Next_Elmt
(Disc_Elmt
);
7092 Next_Discriminant
(Discrim
);
7093 exit when not Present
(Discrim
);
7098 | N_Extension_Aggregate
7100 -- Unimplemented: extension aggregate case where discrims
7101 -- come from ancestor part, not extension part.
7104 Discrim
: Entity_Id
:=
7105 First_Discriminant
(Base_Type
(R_Type
));
7107 Disc_Exp
: Node_Id
:= Empty
;
7109 Positionals_Exhausted
7110 : Boolean := not Present
(Expressions
7113 function Associated_Expr
7114 (Comp_Id
: Entity_Id
;
7115 Associations
: List_Id
) return Node_Id
;
7117 -- Given a component and a component associations list,
7118 -- locate the expression for that component; returns
7119 -- Empty if no such expression is found.
7121 ---------------------
7122 -- Associated_Expr --
7123 ---------------------
7125 function Associated_Expr
7126 (Comp_Id
: Entity_Id
;
7127 Associations
: List_Id
) return Node_Id
7133 -- Simple linear search seems ok here
7135 Assoc
:= First
(Associations
);
7136 while Present
(Assoc
) loop
7137 Choice
:= First
(Choices
(Assoc
));
7138 while Present
(Choice
) loop
7139 if (Nkind
(Choice
) = N_Identifier
7140 and then Chars
(Choice
) = Chars
(Comp_Id
))
7141 or else (Nkind
(Choice
) = N_Others_Choice
)
7143 return Expression
(Assoc
);
7153 end Associated_Expr
;
7156 if not Positionals_Exhausted
then
7157 Disc_Exp
:= First
(Expressions
(Discrim_Source
));
7161 if Positionals_Exhausted
then
7165 Component_Associations
(Discrim_Source
));
7168 if Ekind
(Etype
(Discrim
)) =
7169 E_Anonymous_Access_Type
7171 Check_Against_Result_Level
7172 (Dynamic_Accessibility_Level
(Disc_Exp
));
7175 Next_Discriminant
(Discrim
);
7176 exit when not Present
(Discrim
);
7178 if not Positionals_Exhausted
then
7180 Positionals_Exhausted
:= not Present
(Disc_Exp
);
7185 when N_Function_Call
=>
7187 -- No check needed (check performed by callee)
7193 Level
: constant Node_Id
:=
7194 Make_Integer_Literal
(Loc
,
7195 Object_Access_Level
(Discrim_Source
));
7198 -- Unimplemented: check for name prefix that includes
7199 -- a dereference of an access value with a dynamic
7200 -- accessibility level (e.g., an access param or a
7201 -- saooaaat) and use dynamic level in that case. For
7203 -- return Access_Param.all(Some_Index).Some_Component;
7206 Set_Etype
(Level
, Standard_Natural
);
7207 Check_Against_Result_Level
(Level
);
7213 -- If we are returning an object that may not be bit-aligned, then copy
7214 -- the value into a temporary first. This copy may need to expand to a
7215 -- loop of component operations.
7217 if Is_Possibly_Unaligned_Slice
(Exp
)
7218 or else Is_Possibly_Unaligned_Object
(Exp
)
7221 ExpR
: constant Node_Id
:= Relocate_Node
(Exp
);
7222 Tnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T', ExpR
);
7225 Make_Object_Declaration
(Loc
,
7226 Defining_Identifier
=> Tnn
,
7227 Constant_Present
=> True,
7228 Object_Definition
=> New_Occurrence_Of
(R_Type
, Loc
),
7229 Expression
=> ExpR
),
7230 Suppress
=> All_Checks
);
7231 Rewrite
(Exp
, New_Occurrence_Of
(Tnn
, Loc
));
7235 -- Call the _Postconditions procedure if the related function has
7236 -- contract assertions that need to be verified on exit.
7238 if Ekind
(Scope_Id
) = E_Function
7239 and then Present
(Postconditions_Proc
(Scope_Id
))
7241 -- In the case of discriminated objects, we have created a
7242 -- constrained subtype above, and used the underlying type. This
7243 -- transformation is post-analysis and harmless, except that now the
7244 -- call to the post-condition will be analyzed and the type kinds
7247 if Nkind
(Exp
) = N_Unchecked_Type_Conversion
7248 and then Is_Private_Type
(R_Type
) /= Is_Private_Type
(Etype
(Exp
))
7250 Rewrite
(Exp
, Expression
(Relocate_Node
(Exp
)));
7253 -- We are going to reference the returned value twice in this case,
7254 -- once in the call to _Postconditions, and once in the actual return
7255 -- statement, but we can't have side effects happening twice.
7257 Force_Evaluation
(Exp
, Mode
=> Strict
);
7259 -- Generate call to _Postconditions
7262 Make_Procedure_Call_Statement
(Loc
,
7264 New_Occurrence_Of
(Postconditions_Proc
(Scope_Id
), Loc
),
7265 Parameter_Associations
=> New_List
(New_Copy_Tree
(Exp
))));
7268 -- Ada 2005 (AI-251): If this return statement corresponds with an
7269 -- simple return statement associated with an extended return statement
7270 -- and the type of the returned object is an interface then generate an
7271 -- implicit conversion to force displacement of the "this" pointer.
7273 if Ada_Version
>= Ada_2005
7274 and then Comes_From_Extended_Return_Statement
(N
)
7275 and then Nkind
(Expression
(N
)) = N_Identifier
7276 and then Is_Interface
(Utyp
)
7277 and then Utyp
/= Underlying_Type
(Exptyp
)
7279 Rewrite
(Exp
, Convert_To
(Utyp
, Relocate_Node
(Exp
)));
7280 Analyze_And_Resolve
(Exp
);
7282 end Expand_Simple_Function_Return
;
7284 -----------------------
7285 -- Freeze_Subprogram --
7286 -----------------------
7288 procedure Freeze_Subprogram
(N
: Node_Id
) is
7289 Loc
: constant Source_Ptr
:= Sloc
(N
);
7291 procedure Register_Predefined_DT_Entry
(Prim
: Entity_Id
);
7292 -- (Ada 2005): Register a predefined primitive in all the secondary
7293 -- dispatch tables of its primitive type.
7295 ----------------------------------
7296 -- Register_Predefined_DT_Entry --
7297 ----------------------------------
7299 procedure Register_Predefined_DT_Entry
(Prim
: Entity_Id
) is
7300 Iface_DT_Ptr
: Elmt_Id
;
7301 Tagged_Typ
: Entity_Id
;
7302 Thunk_Id
: Entity_Id
;
7303 Thunk_Code
: Node_Id
;
7306 Tagged_Typ
:= Find_Dispatching_Type
(Prim
);
7308 if No
(Access_Disp_Table
(Tagged_Typ
))
7309 or else not Has_Interfaces
(Tagged_Typ
)
7310 or else not RTE_Available
(RE_Interface_Tag
)
7311 or else Restriction_Active
(No_Dispatching_Calls
)
7316 -- Skip the first two access-to-dispatch-table pointers since they
7317 -- leads to the primary dispatch table (predefined DT and user
7318 -- defined DT). We are only concerned with the secondary dispatch
7319 -- table pointers. Note that the access-to- dispatch-table pointer
7320 -- corresponds to the first implemented interface retrieved below.
7323 Next_Elmt
(Next_Elmt
(First_Elmt
(Access_Disp_Table
(Tagged_Typ
))));
7325 while Present
(Iface_DT_Ptr
)
7326 and then Ekind
(Node
(Iface_DT_Ptr
)) = E_Constant
7328 pragma Assert
(Has_Thunks
(Node
(Iface_DT_Ptr
)));
7329 Expand_Interface_Thunk
(Prim
, Thunk_Id
, Thunk_Code
);
7331 if Present
(Thunk_Code
) then
7332 Insert_Actions_After
(N
, New_List
(
7335 Build_Set_Predefined_Prim_Op_Address
(Loc
,
7337 New_Occurrence_Of
(Node
(Next_Elmt
(Iface_DT_Ptr
)), Loc
),
7338 Position
=> DT_Position
(Prim
),
7340 Unchecked_Convert_To
(RTE
(RE_Prim_Ptr
),
7341 Make_Attribute_Reference
(Loc
,
7342 Prefix
=> New_Occurrence_Of
(Thunk_Id
, Loc
),
7343 Attribute_Name
=> Name_Unrestricted_Access
))),
7345 Build_Set_Predefined_Prim_Op_Address
(Loc
,
7348 (Node
(Next_Elmt
(Next_Elmt
(Next_Elmt
(Iface_DT_Ptr
)))),
7350 Position
=> DT_Position
(Prim
),
7352 Unchecked_Convert_To
(RTE
(RE_Prim_Ptr
),
7353 Make_Attribute_Reference
(Loc
,
7354 Prefix
=> New_Occurrence_Of
(Prim
, Loc
),
7355 Attribute_Name
=> Name_Unrestricted_Access
)))));
7358 -- Skip the tag of the predefined primitives dispatch table
7360 Next_Elmt
(Iface_DT_Ptr
);
7361 pragma Assert
(Has_Thunks
(Node
(Iface_DT_Ptr
)));
7363 -- Skip tag of the no-thunks dispatch table
7365 Next_Elmt
(Iface_DT_Ptr
);
7366 pragma Assert
(not Has_Thunks
(Node
(Iface_DT_Ptr
)));
7368 -- Skip tag of predefined primitives no-thunks dispatch table
7370 Next_Elmt
(Iface_DT_Ptr
);
7371 pragma Assert
(not Has_Thunks
(Node
(Iface_DT_Ptr
)));
7373 Next_Elmt
(Iface_DT_Ptr
);
7375 end Register_Predefined_DT_Entry
;
7379 Subp
: constant Entity_Id
:= Entity
(N
);
7381 -- Start of processing for Freeze_Subprogram
7384 -- We suppress the initialization of the dispatch table entry when
7385 -- not Tagged_Type_Expansion because the dispatching mechanism is
7386 -- handled internally by the target.
7388 if Is_Dispatching_Operation
(Subp
)
7389 and then not Is_Abstract_Subprogram
(Subp
)
7390 and then Present
(DTC_Entity
(Subp
))
7391 and then Present
(Scope
(DTC_Entity
(Subp
)))
7392 and then Tagged_Type_Expansion
7393 and then not Restriction_Active
(No_Dispatching_Calls
)
7394 and then RTE_Available
(RE_Tag
)
7397 Typ
: constant Entity_Id
:= Scope
(DTC_Entity
(Subp
));
7400 -- Handle private overridden primitives
7402 if not Is_CPP_Class
(Typ
) then
7403 Check_Overriding_Operation
(Subp
);
7406 -- We assume that imported CPP primitives correspond with objects
7407 -- whose constructor is in the CPP side; therefore we don't need
7408 -- to generate code to register them in the dispatch table.
7410 if Is_CPP_Class
(Typ
) then
7413 -- Handle CPP primitives found in derivations of CPP_Class types.
7414 -- These primitives must have been inherited from some parent, and
7415 -- there is no need to register them in the dispatch table because
7416 -- Build_Inherit_Prims takes care of initializing these slots.
7418 elsif Is_Imported
(Subp
)
7419 and then (Convention
(Subp
) = Convention_CPP
7420 or else Convention
(Subp
) = Convention_C
)
7424 -- Generate code to register the primitive in non statically
7425 -- allocated dispatch tables
7427 elsif not Building_Static_DT
(Scope
(DTC_Entity
(Subp
))) then
7429 -- When a primitive is frozen, enter its name in its dispatch
7432 if not Is_Interface
(Typ
)
7433 or else Present
(Interface_Alias
(Subp
))
7435 if Is_Predefined_Dispatching_Operation
(Subp
) then
7436 Register_Predefined_DT_Entry
(Subp
);
7439 Insert_Actions_After
(N
,
7440 Register_Primitive
(Loc
, Prim
=> Subp
));
7446 -- Mark functions that return by reference. Note that it cannot be part
7447 -- of the normal semantic analysis of the spec since the underlying
7448 -- returned type may not be known yet (for private types).
7451 Typ
: constant Entity_Id
:= Etype
(Subp
);
7452 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
7455 if Is_Limited_View
(Typ
) then
7456 Set_Returns_By_Ref
(Subp
);
7458 elsif Present
(Utyp
) and then CW_Or_Has_Controlled_Part
(Utyp
) then
7459 Set_Returns_By_Ref
(Subp
);
7463 -- Wnen freezing a null procedure, analyze its delayed aspects now
7464 -- because we may not have reached the end of the declarative list when
7465 -- delayed aspects are normally analyzed. This ensures that dispatching
7466 -- calls are properly rewritten when the generated _Postcondition
7467 -- procedure is analyzed in the null procedure body.
7469 if Nkind
(Parent
(Subp
)) = N_Procedure_Specification
7470 and then Null_Present
(Parent
(Subp
))
7472 Analyze_Entry_Or_Subprogram_Contract
(Subp
);
7474 end Freeze_Subprogram
;
7476 --------------------------------------------
7477 -- Has_Unconstrained_Access_Discriminants --
7478 --------------------------------------------
7480 function Has_Unconstrained_Access_Discriminants
7481 (Subtyp
: Entity_Id
) return Boolean
7486 if Has_Discriminants
(Subtyp
)
7487 and then not Is_Constrained
(Subtyp
)
7489 Discr
:= First_Discriminant
(Subtyp
);
7490 while Present
(Discr
) loop
7491 if Ekind
(Etype
(Discr
)) = E_Anonymous_Access_Type
then
7495 Next_Discriminant
(Discr
);
7500 end Has_Unconstrained_Access_Discriminants
;
7502 ------------------------------
7503 -- Insert_Post_Call_Actions --
7504 ------------------------------
7506 procedure Insert_Post_Call_Actions
(N
: Node_Id
; Post_Call
: List_Id
) is
7507 Context
: constant Node_Id
:= Parent
(N
);
7510 if Is_Empty_List
(Post_Call
) then
7514 -- Cases where the call is not a member of a statement list. This
7515 -- includes the case where the call is an actual in another function
7516 -- call or indexing, i.e. an expression context as well.
7518 if not Is_List_Member
(N
)
7519 or else Nkind_In
(Context
, N_Function_Call
, N_Indexed_Component
)
7521 -- In Ada 2012 the call may be a function call in an expression
7522 -- (since OUT and IN OUT parameters are now allowed for such calls).
7523 -- The write-back of (in)-out parameters is handled by the back-end,
7524 -- but the constraint checks generated when subtypes of formal and
7525 -- actual don't match must be inserted in the form of assignments.
7527 if Nkind
(Original_Node
(N
)) = N_Function_Call
then
7528 pragma Assert
(Ada_Version
>= Ada_2012
);
7529 -- Functions with '[in] out' parameters are only allowed in Ada
7532 -- We used to handle this by climbing up parents to a
7533 -- non-statement/declaration and then simply making a call to
7534 -- Insert_Actions_After (P, Post_Call), but that doesn't work
7535 -- for Ada 2012. If we are in the middle of an expression, e.g.
7536 -- the condition of an IF, this call would insert after the IF
7537 -- statement, which is much too late to be doing the write back.
7540 -- if Clobber (X) then
7541 -- Put_Line (X'Img);
7546 -- Now assume Clobber changes X, if we put the write back after
7547 -- the IF, the Put_Line gets the wrong value and the goto causes
7548 -- the write back to be skipped completely.
7550 -- To deal with this, we replace the call by
7553 -- Tnnn : constant function-result-type := function-call;
7554 -- Post_Call actions
7560 Loc
: constant Source_Ptr
:= Sloc
(N
);
7561 Tnnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
7562 FRTyp
: constant Entity_Id
:= Etype
(N
);
7563 Name
: constant Node_Id
:= Relocate_Node
(N
);
7566 Prepend_To
(Post_Call
,
7567 Make_Object_Declaration
(Loc
,
7568 Defining_Identifier
=> Tnnn
,
7569 Object_Definition
=> New_Occurrence_Of
(FRTyp
, Loc
),
7570 Constant_Present
=> True,
7571 Expression
=> Name
));
7574 Make_Expression_With_Actions
(Loc
,
7575 Actions
=> Post_Call
,
7576 Expression
=> New_Occurrence_Of
(Tnnn
, Loc
)));
7578 -- We don't want to just blindly call Analyze_And_Resolve
7579 -- because that would cause unwanted recursion on the call.
7580 -- So for a moment set the call as analyzed to prevent that
7581 -- recursion, and get the rest analyzed properly, then reset
7582 -- the analyzed flag, so our caller can continue.
7584 Set_Analyzed
(Name
, True);
7585 Analyze_And_Resolve
(N
, FRTyp
);
7586 Set_Analyzed
(Name
, False);
7589 -- If not the special Ada 2012 case of a function call, then we must
7590 -- have the triggering statement of a triggering alternative or an
7591 -- entry call alternative, and we can add the post call stuff to the
7592 -- corresponding statement list.
7595 pragma Assert
(Nkind_In
(Context
, N_Entry_Call_Alternative
,
7596 N_Triggering_Alternative
));
7598 if Is_Non_Empty_List
(Statements
(Context
)) then
7599 Insert_List_Before_And_Analyze
7600 (First
(Statements
(Context
)), Post_Call
);
7602 Set_Statements
(Context
, Post_Call
);
7606 -- A procedure call is always part of a declarative or statement list,
7607 -- however a function call may appear nested within a construct. Most
7608 -- cases of function call nesting are handled in the special case above.
7609 -- The only exception is when the function call acts as an actual in a
7610 -- procedure call. In this case the function call is in a list, but the
7611 -- post-call actions must be inserted after the procedure call.
7613 elsif Nkind
(Context
) = N_Procedure_Call_Statement
then
7614 Insert_Actions_After
(Context
, Post_Call
);
7616 -- Otherwise, normal case where N is in a statement sequence, just put
7617 -- the post-call stuff after the call statement.
7620 Insert_Actions_After
(N
, Post_Call
);
7622 end Insert_Post_Call_Actions
;
7624 -----------------------------------
7625 -- Is_Build_In_Place_Result_Type --
7626 -----------------------------------
7628 function Is_Build_In_Place_Result_Type
(Typ
: Entity_Id
) return Boolean is
7630 if not Expander_Active
then
7634 -- In Ada 2005 all functions with an inherently limited return type
7635 -- must be handled using a build-in-place profile, including the case
7636 -- of a function with a limited interface result, where the function
7637 -- may return objects of nonlimited descendants.
7639 if Is_Limited_View
(Typ
) then
7640 return Ada_Version
>= Ada_2005
and then not Debug_Flag_Dot_L
;
7643 if Debug_Flag_Dot_9
then
7647 if Has_Interfaces
(Typ
) then
7652 T
: Entity_Id
:= Typ
;
7654 -- For T'Class, return True if it's True for T. This is necessary
7655 -- because a class-wide function might say "return F (...)", where
7656 -- F returns the corresponding specific type. We need a loop in
7657 -- case T is a subtype of a class-wide type.
7659 while Is_Class_Wide_Type
(T
) loop
7663 -- If this is a generic formal type in an instance, return True if
7664 -- it's True for the generic actual type.
7666 if Nkind
(Parent
(T
)) = N_Subtype_Declaration
7667 and then Present
(Generic_Parent_Type
(Parent
(T
)))
7669 T
:= Entity
(Subtype_Indication
(Parent
(T
)));
7671 if Present
(Full_View
(T
)) then
7676 if Present
(Underlying_Type
(T
)) then
7677 T
:= Underlying_Type
(T
);
7682 -- So we can stop here in the debugger
7684 -- ???For now, enable build-in-place for a very narrow set of
7685 -- controlled types. Change "if True" to "if False" to
7686 -- experiment with more controlled types. Eventually, we might
7687 -- like to enable build-in-place for all tagged types, all
7688 -- types that need finalization, and all caller-unknown-size
7692 Result
:= Is_Controlled
(T
)
7693 and then Present
(Enclosing_Subprogram
(T
))
7694 and then not Is_Compilation_Unit
(Enclosing_Subprogram
(T
))
7695 and then Ekind
(Enclosing_Subprogram
(T
)) = E_Procedure
;
7697 Result
:= Is_Controlled
(T
);
7704 end Is_Build_In_Place_Result_Type
;
7706 --------------------------------
7707 -- Is_Build_In_Place_Function --
7708 --------------------------------
7710 function Is_Build_In_Place_Function
(E
: Entity_Id
) return Boolean is
7712 -- This function is called from Expand_Subtype_From_Expr during
7713 -- semantic analysis, even when expansion is off. In those cases
7714 -- the build_in_place expansion will not take place.
7716 if not Expander_Active
then
7720 -- For now we test whether E denotes a function or access-to-function
7721 -- type whose result subtype is inherently limited. Later this test
7722 -- may be revised to allow composite nonlimited types. Functions with
7723 -- a foreign convention or whose result type has a foreign convention
7726 if Ekind_In
(E
, E_Function
, E_Generic_Function
)
7727 or else (Ekind
(E
) = E_Subprogram_Type
7728 and then Etype
(E
) /= Standard_Void_Type
)
7730 -- Note: If the function has a foreign convention, it cannot build
7731 -- its result in place, so you're on your own. On the other hand,
7732 -- if only the return type has a foreign convention, its layout is
7733 -- intended to be compatible with the other language, but the build-
7734 -- in place machinery can ensure that the object is not copied.
7736 return Is_Build_In_Place_Result_Type
(Etype
(E
))
7737 and then not Has_Foreign_Convention
(E
)
7738 and then not Debug_Flag_Dot_L
;
7742 end Is_Build_In_Place_Function
;
7744 -------------------------------------
7745 -- Is_Build_In_Place_Function_Call --
7746 -------------------------------------
7748 function Is_Build_In_Place_Function_Call
(N
: Node_Id
) return Boolean is
7749 Exp_Node
: constant Node_Id
:= Unqual_Conv
(N
);
7750 Function_Id
: Entity_Id
;
7753 -- Return False if the expander is currently inactive, since awareness
7754 -- of build-in-place treatment is only relevant during expansion. Note
7755 -- that Is_Build_In_Place_Function, which is called as part of this
7756 -- function, is also conditioned this way, but we need to check here as
7757 -- well to avoid blowing up on processing protected calls when expansion
7758 -- is disabled (such as with -gnatc) since those would trip over the
7759 -- raise of Program_Error below.
7761 -- In SPARK mode, build-in-place calls are not expanded, so that we
7762 -- may end up with a call that is neither resolved to an entity, nor
7763 -- an indirect call.
7765 if not Expander_Active
or else Nkind
(Exp_Node
) /= N_Function_Call
then
7769 if Is_Entity_Name
(Name
(Exp_Node
)) then
7770 Function_Id
:= Entity
(Name
(Exp_Node
));
7772 -- In the case of an explicitly dereferenced call, use the subprogram
7773 -- type generated for the dereference.
7775 elsif Nkind
(Name
(Exp_Node
)) = N_Explicit_Dereference
then
7776 Function_Id
:= Etype
(Name
(Exp_Node
));
7778 -- This may be a call to a protected function.
7780 elsif Nkind
(Name
(Exp_Node
)) = N_Selected_Component
then
7781 Function_Id
:= Etype
(Entity
(Selector_Name
(Name
(Exp_Node
))));
7784 raise Program_Error
;
7788 Result
: constant Boolean := Is_Build_In_Place_Function
(Function_Id
);
7789 -- So we can stop here in the debugger
7793 end Is_Build_In_Place_Function_Call
;
7795 -----------------------
7796 -- Is_Null_Procedure --
7797 -----------------------
7799 function Is_Null_Procedure
(Subp
: Entity_Id
) return Boolean is
7800 Decl
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
7803 if Ekind
(Subp
) /= E_Procedure
then
7806 -- Check if this is a declared null procedure
7808 elsif Nkind
(Decl
) = N_Subprogram_Declaration
then
7809 if not Null_Present
(Specification
(Decl
)) then
7812 elsif No
(Body_To_Inline
(Decl
)) then
7815 -- Check if the body contains only a null statement, followed by
7816 -- the return statement added during expansion.
7820 Orig_Bod
: constant Node_Id
:= Body_To_Inline
(Decl
);
7826 if Nkind
(Orig_Bod
) /= N_Subprogram_Body
then
7829 -- We must skip SCIL nodes because they are currently
7830 -- implemented as special N_Null_Statement nodes.
7834 (Statements
(Handled_Statement_Sequence
(Orig_Bod
)));
7835 Stat2
:= Next_Non_SCIL_Node
(Stat
);
7838 Is_Empty_List
(Declarations
(Orig_Bod
))
7839 and then Nkind
(Stat
) = N_Null_Statement
7843 (Nkind
(Stat2
) = N_Simple_Return_Statement
7844 and then No
(Next
(Stat2
))));
7852 end Is_Null_Procedure
;
7854 -------------------------------------------
7855 -- Make_Build_In_Place_Call_In_Allocator --
7856 -------------------------------------------
7858 procedure Make_Build_In_Place_Call_In_Allocator
7859 (Allocator
: Node_Id
;
7860 Function_Call
: Node_Id
)
7862 Acc_Type
: constant Entity_Id
:= Etype
(Allocator
);
7863 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
7864 Func_Call
: Node_Id
:= Function_Call
;
7865 Ref_Func_Call
: Node_Id
;
7866 Function_Id
: Entity_Id
;
7867 Result_Subt
: Entity_Id
;
7868 New_Allocator
: Node_Id
;
7869 Return_Obj_Access
: Entity_Id
; -- temp for function result
7870 Temp_Init
: Node_Id
; -- initial value of Return_Obj_Access
7871 Alloc_Form
: BIP_Allocation_Form
;
7872 Pool
: Node_Id
; -- nonnull if Alloc_Form = User_Storage_Pool
7873 Return_Obj_Actual
: Node_Id
; -- the temp.all, in caller-allocates case
7874 Chain
: Entity_Id
; -- activation chain, in case of tasks
7877 -- Step past qualification or unchecked conversion (the latter can occur
7878 -- in cases of calls to 'Input).
7880 if Nkind_In
(Func_Call
, N_Qualified_Expression
,
7882 N_Unchecked_Type_Conversion
)
7884 Func_Call
:= Expression
(Func_Call
);
7887 -- Mark the call as processed as a build-in-place call
7889 pragma Assert
(not Is_Expanded_Build_In_Place_Call
(Func_Call
));
7890 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
7892 if Is_Entity_Name
(Name
(Func_Call
)) then
7893 Function_Id
:= Entity
(Name
(Func_Call
));
7895 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
7896 Function_Id
:= Etype
(Name
(Func_Call
));
7899 raise Program_Error
;
7902 Result_Subt
:= Available_View
(Etype
(Function_Id
));
7904 -- Create a temp for the function result. In the caller-allocates case,
7905 -- this will be initialized to the result of a new uninitialized
7906 -- allocator. Note: we do not use Allocator as the Related_Node of
7907 -- Return_Obj_Access in call to Make_Temporary below as this would
7908 -- create a sort of infinite "recursion".
7910 Return_Obj_Access
:= Make_Temporary
(Loc
, 'R');
7911 Set_Etype
(Return_Obj_Access
, Acc_Type
);
7912 Set_Can_Never_Be_Null
(Acc_Type
, False);
7913 -- It gets initialized to null, so we can't have that
7915 -- When the result subtype is constrained, the return object is created
7916 -- on the caller side, and access to it is passed to the function. This
7917 -- optimization is disabled when the result subtype needs finalization
7918 -- actions because the caller side allocation may result in undesirable
7919 -- finalization. Consider the following example:
7921 -- function Make_Lim_Ctrl return Lim_Ctrl is
7923 -- return Result : Lim_Ctrl := raise Program_Error do
7926 -- end Make_Lim_Ctrl;
7928 -- Obj : Lim_Ctrl_Ptr := new Lim_Ctrl'(Make_Lim_Ctrl);
7930 -- Even though the size of limited controlled type Lim_Ctrl is known,
7931 -- allocating Obj at the caller side will chain Obj on Lim_Ctrl_Ptr's
7932 -- finalization master. The subsequent call to Make_Lim_Ctrl will fail
7933 -- during the initialization actions for Result, which implies that
7934 -- Result (and Obj by extension) should not be finalized. However Obj
7935 -- will be finalized when access type Lim_Ctrl_Ptr goes out of scope
7936 -- since it is already attached on the related finalization master.
7938 -- Here and in related routines, we must examine the full view of the
7939 -- type, because the view at the point of call may differ from that
7940 -- that in the function body, and the expansion mechanism depends on
7941 -- the characteristics of the full view.
7943 if Is_Constrained
(Underlying_Type
(Result_Subt
))
7944 and then not Needs_Finalization
(Underlying_Type
(Result_Subt
))
7946 -- Replace the initialized allocator of form "new T'(Func (...))"
7947 -- with an uninitialized allocator of form "new T", where T is the
7948 -- result subtype of the called function. The call to the function
7949 -- is handled separately further below.
7952 Make_Allocator
(Loc
,
7953 Expression
=> New_Occurrence_Of
(Result_Subt
, Loc
));
7954 Set_No_Initialization
(New_Allocator
);
7956 -- Copy attributes to new allocator. Note that the new allocator
7957 -- logically comes from source if the original one did, so copy the
7958 -- relevant flag. This ensures proper treatment of the restriction
7959 -- No_Implicit_Heap_Allocations in this case.
7961 Set_Storage_Pool
(New_Allocator
, Storage_Pool
(Allocator
));
7962 Set_Procedure_To_Call
(New_Allocator
, Procedure_To_Call
(Allocator
));
7963 Set_Comes_From_Source
(New_Allocator
, Comes_From_Source
(Allocator
));
7965 Rewrite
(Allocator
, New_Allocator
);
7967 -- Initial value of the temp is the result of the uninitialized
7968 -- allocator. Unchecked_Convert is needed for T'Input where T is
7969 -- derived from a controlled type.
7971 Temp_Init
:= Relocate_Node
(Allocator
);
7973 if Nkind_In
(Function_Call
, N_Type_Conversion
,
7974 N_Unchecked_Type_Conversion
)
7976 Temp_Init
:= Unchecked_Convert_To
(Acc_Type
, Temp_Init
);
7979 -- Indicate that caller allocates, and pass in the return object
7981 Alloc_Form
:= Caller_Allocation
;
7982 Pool
:= Make_Null
(No_Location
);
7983 Return_Obj_Actual
:=
7984 Make_Unchecked_Type_Conversion
(Loc
,
7985 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
7987 Make_Explicit_Dereference
(Loc
,
7988 Prefix
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
)));
7990 -- When the result subtype is unconstrained, the function itself must
7991 -- perform the allocation of the return object, so we pass parameters
7997 -- Case of a user-defined storage pool. Pass an allocation parameter
7998 -- indicating that the function should allocate its result in the
7999 -- pool, and pass the pool. Use 'Unrestricted_Access because the
8000 -- pool may not be aliased.
8002 if Present
(Associated_Storage_Pool
(Acc_Type
)) then
8003 Alloc_Form
:= User_Storage_Pool
;
8005 Make_Attribute_Reference
(Loc
,
8008 (Associated_Storage_Pool
(Acc_Type
), Loc
),
8009 Attribute_Name
=> Name_Unrestricted_Access
);
8011 -- No user-defined pool; pass an allocation parameter indicating that
8012 -- the function should allocate its result on the heap.
8015 Alloc_Form
:= Global_Heap
;
8016 Pool
:= Make_Null
(No_Location
);
8019 -- The caller does not provide the return object in this case, so we
8020 -- have to pass null for the object access actual.
8022 Return_Obj_Actual
:= Empty
;
8025 -- Declare the temp object
8027 Insert_Action
(Allocator
,
8028 Make_Object_Declaration
(Loc
,
8029 Defining_Identifier
=> Return_Obj_Access
,
8030 Object_Definition
=> New_Occurrence_Of
(Acc_Type
, Loc
),
8031 Expression
=> Temp_Init
));
8033 Ref_Func_Call
:= Make_Reference
(Loc
, Func_Call
);
8035 -- Ada 2005 (AI-251): If the type of the allocator is an interface
8036 -- then generate an implicit conversion to force displacement of the
8039 if Is_Interface
(Designated_Type
(Acc_Type
)) then
8042 OK_Convert_To
(Acc_Type
, Ref_Func_Call
));
8044 -- If the types are incompatible, we need an unchecked conversion. Note
8045 -- that the full types will be compatible, but the types not visibly
8048 elsif Nkind_In
(Function_Call
, N_Type_Conversion
,
8049 N_Unchecked_Type_Conversion
)
8051 Ref_Func_Call
:= Unchecked_Convert_To
(Acc_Type
, Ref_Func_Call
);
8055 Assign
: constant Node_Id
:=
8056 Make_Assignment_Statement
(Loc
,
8057 Name
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
),
8058 Expression
=> Ref_Func_Call
);
8059 -- Assign the result of the function call into the temp. In the
8060 -- caller-allocates case, this is overwriting the temp with its
8061 -- initial value, which has no effect. In the callee-allocates case,
8062 -- this is setting the temp to point to the object allocated by the
8063 -- callee. Unchecked_Convert is needed for T'Input where T is derived
8064 -- from a controlled type.
8067 -- Actions to be inserted. If there are no tasks, this is just the
8068 -- assignment statement. If the allocated object has tasks, we need
8069 -- to wrap the assignment in a block that activates them. The
8070 -- activation chain of that block must be passed to the function,
8071 -- rather than some outer chain.
8074 if Has_Task
(Result_Subt
) then
8075 Actions
:= New_List
;
8076 Build_Task_Allocate_Block_With_Init_Stmts
8077 (Actions
, Allocator
, Init_Stmts
=> New_List
(Assign
));
8078 Chain
:= Activation_Chain_Entity
(Last
(Actions
));
8080 Actions
:= New_List
(Assign
);
8084 Insert_Actions
(Allocator
, Actions
);
8087 -- When the function has a controlling result, an allocation-form
8088 -- parameter must be passed indicating that the caller is allocating
8089 -- the result object. This is needed because such a function can be
8090 -- called as a dispatching operation and must be treated similarly
8091 -- to functions with unconstrained result subtypes.
8093 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8094 (Func_Call
, Function_Id
, Alloc_Form
, Pool_Actual
=> Pool
);
8096 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8097 (Func_Call
, Function_Id
, Acc_Type
);
8099 Add_Task_Actuals_To_Build_In_Place_Call
8100 (Func_Call
, Function_Id
, Master_Actual
=> Master_Id
(Acc_Type
),
8103 -- Add an implicit actual to the function call that provides access
8104 -- to the allocated object. An unchecked conversion to the (specific)
8105 -- result subtype of the function is inserted to handle cases where
8106 -- the access type of the allocator has a class-wide designated type.
8108 Add_Access_Actual_To_Build_In_Place_Call
8109 (Func_Call
, Function_Id
, Return_Obj_Actual
);
8111 -- Finally, replace the allocator node with a reference to the temp
8113 Rewrite
(Allocator
, New_Occurrence_Of
(Return_Obj_Access
, Loc
));
8115 Analyze_And_Resolve
(Allocator
, Acc_Type
);
8116 end Make_Build_In_Place_Call_In_Allocator
;
8118 ---------------------------------------------------
8119 -- Make_Build_In_Place_Call_In_Anonymous_Context --
8120 ---------------------------------------------------
8122 procedure Make_Build_In_Place_Call_In_Anonymous_Context
8123 (Function_Call
: Node_Id
)
8125 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8126 Func_Call
: constant Node_Id
:= Unqual_Conv
(Function_Call
);
8127 Function_Id
: Entity_Id
;
8128 Result_Subt
: Entity_Id
;
8129 Return_Obj_Id
: Entity_Id
;
8130 Return_Obj_Decl
: Entity_Id
;
8133 -- If the call has already been processed to add build-in-place actuals
8134 -- then return. One place this can occur is for calls to build-in-place
8135 -- functions that occur within a call to a protected operation, where
8136 -- due to rewriting and expansion of the protected call there can be
8137 -- more than one call to Expand_Actuals for the same set of actuals.
8139 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
8143 -- Mark the call as processed as a build-in-place call
8145 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
8147 if Is_Entity_Name
(Name
(Func_Call
)) then
8148 Function_Id
:= Entity
(Name
(Func_Call
));
8150 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
8151 Function_Id
:= Etype
(Name
(Func_Call
));
8154 raise Program_Error
;
8157 Result_Subt
:= Etype
(Function_Id
);
8159 -- If the build-in-place function returns a controlled object, then the
8160 -- object needs to be finalized immediately after the context. Since
8161 -- this case produces a transient scope, the servicing finalizer needs
8162 -- to name the returned object. Create a temporary which is initialized
8163 -- with the function call:
8165 -- Temp_Id : Func_Type := BIP_Func_Call;
8167 -- The initialization expression of the temporary will be rewritten by
8168 -- the expander using the appropriate mechanism in Make_Build_In_Place_
8169 -- Call_In_Object_Declaration.
8171 if Needs_Finalization
(Result_Subt
) then
8173 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'R');
8174 Temp_Decl
: Node_Id
;
8177 -- Reset the guard on the function call since the following does
8178 -- not perform actual call expansion.
8180 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
, False);
8183 Make_Object_Declaration
(Loc
,
8184 Defining_Identifier
=> Temp_Id
,
8185 Object_Definition
=>
8186 New_Occurrence_Of
(Result_Subt
, Loc
),
8188 New_Copy_Tree
(Function_Call
));
8190 Insert_Action
(Function_Call
, Temp_Decl
);
8192 Rewrite
(Function_Call
, New_Occurrence_Of
(Temp_Id
, Loc
));
8193 Analyze
(Function_Call
);
8196 -- When the result subtype is definite, an object of the subtype is
8197 -- declared and an access value designating it is passed as an actual.
8199 elsif Caller_Known_Size
(Func_Call
, Result_Subt
) then
8201 -- Create a temporary object to hold the function result
8203 Return_Obj_Id
:= Make_Temporary
(Loc
, 'R');
8204 Set_Etype
(Return_Obj_Id
, Result_Subt
);
8207 Make_Object_Declaration
(Loc
,
8208 Defining_Identifier
=> Return_Obj_Id
,
8209 Aliased_Present
=> True,
8210 Object_Definition
=> New_Occurrence_Of
(Result_Subt
, Loc
));
8212 Set_No_Initialization
(Return_Obj_Decl
);
8214 Insert_Action
(Func_Call
, Return_Obj_Decl
);
8216 -- When the function has a controlling result, an allocation-form
8217 -- parameter must be passed indicating that the caller is allocating
8218 -- the result object. This is needed because such a function can be
8219 -- called as a dispatching operation and must be treated similarly
8220 -- to functions with unconstrained result subtypes.
8222 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8223 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8225 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8226 (Func_Call
, Function_Id
);
8228 Add_Task_Actuals_To_Build_In_Place_Call
8229 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8231 -- Add an implicit actual to the function call that provides access
8232 -- to the caller's return object.
8234 Add_Access_Actual_To_Build_In_Place_Call
8235 (Func_Call
, Function_Id
, New_Occurrence_Of
(Return_Obj_Id
, Loc
));
8237 -- When the result subtype is unconstrained, the function must allocate
8238 -- the return object in the secondary stack, so appropriate implicit
8239 -- parameters are added to the call to indicate that. A transient
8240 -- scope is established to ensure eventual cleanup of the result.
8243 -- Pass an allocation parameter indicating that the function should
8244 -- allocate its result on the secondary stack.
8246 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8247 (Func_Call
, Function_Id
, Alloc_Form
=> Secondary_Stack
);
8249 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8250 (Func_Call
, Function_Id
);
8252 Add_Task_Actuals_To_Build_In_Place_Call
8253 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8255 -- Pass a null value to the function since no return object is
8256 -- available on the caller side.
8258 Add_Access_Actual_To_Build_In_Place_Call
8259 (Func_Call
, Function_Id
, Empty
);
8261 end Make_Build_In_Place_Call_In_Anonymous_Context
;
8263 --------------------------------------------
8264 -- Make_Build_In_Place_Call_In_Assignment --
8265 --------------------------------------------
8267 procedure Make_Build_In_Place_Call_In_Assignment
8269 Function_Call
: Node_Id
)
8271 Func_Call
: constant Node_Id
:= Unqual_Conv
(Function_Call
);
8272 Lhs
: constant Node_Id
:= Name
(Assign
);
8273 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8274 Func_Id
: Entity_Id
;
8277 Ptr_Typ
: Entity_Id
;
8278 Ptr_Typ_Decl
: Node_Id
;
8280 Result_Subt
: Entity_Id
;
8283 -- Mark the call as processed as a build-in-place call
8285 pragma Assert
(not Is_Expanded_Build_In_Place_Call
(Func_Call
));
8286 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
8288 if Is_Entity_Name
(Name
(Func_Call
)) then
8289 Func_Id
:= Entity
(Name
(Func_Call
));
8291 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
8292 Func_Id
:= Etype
(Name
(Func_Call
));
8295 raise Program_Error
;
8298 Result_Subt
:= Etype
(Func_Id
);
8300 -- When the result subtype is unconstrained, an additional actual must
8301 -- be passed to indicate that the caller is providing the return object.
8302 -- This parameter must also be passed when the called function has a
8303 -- controlling result, because dispatching calls to the function needs
8304 -- to be treated effectively the same as calls to class-wide functions.
8306 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8307 (Func_Call
, Func_Id
, Alloc_Form
=> Caller_Allocation
);
8309 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8310 (Func_Call
, Func_Id
);
8312 Add_Task_Actuals_To_Build_In_Place_Call
8313 (Func_Call
, Func_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8315 -- Add an implicit actual to the function call that provides access to
8316 -- the caller's return object.
8318 Add_Access_Actual_To_Build_In_Place_Call
8321 Make_Unchecked_Type_Conversion
(Loc
,
8322 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
8323 Expression
=> Relocate_Node
(Lhs
)));
8325 -- Create an access type designating the function's result subtype
8327 Ptr_Typ
:= Make_Temporary
(Loc
, 'A');
8330 Make_Full_Type_Declaration
(Loc
,
8331 Defining_Identifier
=> Ptr_Typ
,
8333 Make_Access_To_Object_Definition
(Loc
,
8334 All_Present
=> True,
8335 Subtype_Indication
=>
8336 New_Occurrence_Of
(Result_Subt
, Loc
)));
8337 Insert_After_And_Analyze
(Assign
, Ptr_Typ_Decl
);
8339 -- Finally, create an access object initialized to a reference to the
8340 -- function call. We know this access value is non-null, so mark the
8341 -- entity accordingly to suppress junk access checks.
8343 New_Expr
:= Make_Reference
(Loc
, Relocate_Node
(Func_Call
));
8345 -- Add a conversion if it's the wrong type
8347 if Etype
(New_Expr
) /= Ptr_Typ
then
8349 Make_Unchecked_Type_Conversion
(Loc
,
8350 New_Occurrence_Of
(Ptr_Typ
, Loc
), New_Expr
);
8353 Obj_Id
:= Make_Temporary
(Loc
, 'R', New_Expr
);
8354 Set_Etype
(Obj_Id
, Ptr_Typ
);
8355 Set_Is_Known_Non_Null
(Obj_Id
);
8358 Make_Object_Declaration
(Loc
,
8359 Defining_Identifier
=> Obj_Id
,
8360 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8361 Expression
=> New_Expr
);
8362 Insert_After_And_Analyze
(Ptr_Typ_Decl
, Obj_Decl
);
8364 Rewrite
(Assign
, Make_Null_Statement
(Loc
));
8365 end Make_Build_In_Place_Call_In_Assignment
;
8367 ----------------------------------------------------
8368 -- Make_Build_In_Place_Call_In_Object_Declaration --
8369 ----------------------------------------------------
8371 procedure Make_Build_In_Place_Call_In_Object_Declaration
8372 (Obj_Decl
: Node_Id
;
8373 Function_Call
: Node_Id
)
8375 function Get_Function_Id
(Func_Call
: Node_Id
) return Entity_Id
;
8376 -- Get the value of Function_Id, below
8378 ---------------------
8379 -- Get_Function_Id --
8380 ---------------------
8382 function Get_Function_Id
(Func_Call
: Node_Id
) return Entity_Id
is
8384 if Is_Entity_Name
(Name
(Func_Call
)) then
8385 return Entity
(Name
(Func_Call
));
8387 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
8388 return Etype
(Name
(Func_Call
));
8391 raise Program_Error
;
8393 end Get_Function_Id
;
8397 Func_Call
: constant Node_Id
:= Unqual_Conv
(Function_Call
);
8398 Function_Id
: constant Entity_Id
:= Get_Function_Id
(Func_Call
);
8399 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8400 Obj_Loc
: constant Source_Ptr
:= Sloc
(Obj_Decl
);
8401 Obj_Def_Id
: constant Entity_Id
:= Defining_Identifier
(Obj_Decl
);
8402 Obj_Typ
: constant Entity_Id
:= Etype
(Obj_Def_Id
);
8403 Encl_Func
: constant Entity_Id
:= Enclosing_Subprogram
(Obj_Def_Id
);
8404 Result_Subt
: constant Entity_Id
:= Etype
(Function_Id
);
8406 Call_Deref
: Node_Id
;
8407 Caller_Object
: Node_Id
;
8409 Designated_Type
: Entity_Id
;
8410 Fmaster_Actual
: Node_Id
:= Empty
;
8411 Pool_Actual
: Node_Id
;
8412 Ptr_Typ
: Entity_Id
;
8413 Ptr_Typ_Decl
: Node_Id
;
8414 Pass_Caller_Acc
: Boolean := False;
8417 Definite
: constant Boolean :=
8418 Caller_Known_Size
(Func_Call
, Result_Subt
)
8419 and then not Is_Class_Wide_Type
(Obj_Typ
);
8420 -- In the case of "X : T'Class := F(...);", where F returns a
8421 -- Caller_Known_Size (specific) tagged type, we treat it as
8422 -- indefinite, because the code for the Definite case below sets the
8423 -- initialization expression of the object to Empty, which would be
8424 -- illegal Ada, and would cause gigi to misallocate X.
8426 -- Start of processing for Make_Build_In_Place_Call_In_Object_Declaration
8429 -- If the call has already been processed to add build-in-place actuals
8432 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
8436 -- Mark the call as processed as a build-in-place call
8438 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
8440 -- Create an access type designating the function's result subtype.
8441 -- We use the type of the original call because it may be a call to an
8442 -- inherited operation, which the expansion has replaced with the parent
8443 -- operation that yields the parent type. Note that this access type
8444 -- must be declared before we establish a transient scope, so that it
8445 -- receives the proper accessibility level.
8447 if Is_Class_Wide_Type
(Obj_Typ
)
8448 and then not Is_Interface
(Obj_Typ
)
8449 and then not Is_Class_Wide_Type
(Etype
(Function_Call
))
8451 Designated_Type
:= Obj_Typ
;
8453 Designated_Type
:= Etype
(Function_Call
);
8456 Ptr_Typ
:= Make_Temporary
(Loc
, 'A');
8458 Make_Full_Type_Declaration
(Loc
,
8459 Defining_Identifier
=> Ptr_Typ
,
8461 Make_Access_To_Object_Definition
(Loc
,
8462 All_Present
=> True,
8463 Subtype_Indication
=>
8464 New_Occurrence_Of
(Designated_Type
, Loc
)));
8466 -- The access type and its accompanying object must be inserted after
8467 -- the object declaration in the constrained case, so that the function
8468 -- call can be passed access to the object. In the indefinite case, or
8469 -- if the object declaration is for a return object, the access type and
8470 -- object must be inserted before the object, since the object
8471 -- declaration is rewritten to be a renaming of a dereference of the
8472 -- access object. Note: we need to freeze Ptr_Typ explicitly, because
8473 -- the result object is in a different (transient) scope, so won't cause
8476 if Definite
and then not Is_Return_Object
(Obj_Def_Id
) then
8478 -- The presence of an address clause complicates the build-in-place
8479 -- expansion because the indicated address must be processed before
8480 -- the indirect call is generated (including the definition of a
8481 -- local pointer to the object). The address clause may come from
8482 -- an aspect specification or from an explicit attribute
8483 -- specification appearing after the object declaration. These two
8484 -- cases require different processing.
8486 if Has_Aspect
(Obj_Def_Id
, Aspect_Address
) then
8488 -- Skip non-delayed pragmas that correspond to other aspects, if
8489 -- any, to find proper insertion point for freeze node of object.
8492 D
: Node_Id
:= Obj_Decl
;
8493 N
: Node_Id
:= Next
(D
);
8497 and then Nkind_In
(N
, N_Attribute_Reference
, N_Pragma
)
8504 Insert_After
(D
, Ptr_Typ_Decl
);
8506 -- Freeze object before pointer declaration, to ensure that
8507 -- generated attribute for address is inserted at the proper
8510 Freeze_Before
(Ptr_Typ_Decl
, Obj_Def_Id
);
8513 Analyze
(Ptr_Typ_Decl
);
8515 elsif Present
(Following_Address_Clause
(Obj_Decl
)) then
8517 -- Locate explicit address clause, which may also follow pragmas
8518 -- generated by other aspect specifications.
8521 Addr
: constant Node_Id
:= Following_Address_Clause
(Obj_Decl
);
8522 D
: Node_Id
:= Next
(Obj_Decl
);
8525 while Present
(D
) loop
8531 Insert_After_And_Analyze
(Addr
, Ptr_Typ_Decl
);
8535 Insert_After_And_Analyze
(Obj_Decl
, Ptr_Typ_Decl
);
8538 Insert_Action
(Obj_Decl
, Ptr_Typ_Decl
);
8541 -- Force immediate freezing of Ptr_Typ because Res_Decl will be
8542 -- elaborated in an inner (transient) scope and thus won't cause
8543 -- freezing by itself. It's not an itype, but it needs to be frozen
8544 -- inside the current subprogram (see Freeze_Outside in freeze.adb).
8546 Freeze_Itype
(Ptr_Typ
, Ptr_Typ_Decl
);
8548 -- If the object is a return object of an enclosing build-in-place
8549 -- function, then the implicit build-in-place parameters of the
8550 -- enclosing function are simply passed along to the called function.
8551 -- (Unfortunately, this won't cover the case of extension aggregates
8552 -- where the ancestor part is a build-in-place indefinite function
8553 -- call that should be passed along the caller's parameters.
8554 -- Currently those get mishandled by reassigning the result of the
8555 -- call to the aggregate return object, when the call result should
8556 -- really be directly built in place in the aggregate and not in a
8559 if Is_Return_Object
(Obj_Def_Id
) then
8560 Pass_Caller_Acc
:= True;
8562 -- When the enclosing function has a BIP_Alloc_Form formal then we
8563 -- pass it along to the callee (such as when the enclosing function
8564 -- has an unconstrained or tagged result type).
8566 if Needs_BIP_Alloc_Form
(Encl_Func
) then
8567 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
8570 (Build_In_Place_Formal
8571 (Encl_Func
, BIP_Storage_Pool
), Loc
);
8573 -- The build-in-place pool formal is not built on e.g. ZFP
8576 Pool_Actual
:= Empty
;
8579 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8580 (Function_Call
=> Func_Call
,
8581 Function_Id
=> Function_Id
,
8584 (Build_In_Place_Formal
(Encl_Func
, BIP_Alloc_Form
), Loc
),
8585 Pool_Actual
=> Pool_Actual
);
8587 -- Otherwise, if enclosing function has a definite result subtype,
8588 -- then caller allocation will be used.
8591 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8592 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8595 if Needs_BIP_Finalization_Master
(Encl_Func
) then
8598 (Build_In_Place_Formal
8599 (Encl_Func
, BIP_Finalization_Master
), Loc
);
8602 -- Retrieve the BIPacc formal from the enclosing function and convert
8603 -- it to the access type of the callee's BIP_Object_Access formal.
8606 Make_Unchecked_Type_Conversion
(Loc
,
8609 (Etype
(Build_In_Place_Formal
8610 (Function_Id
, BIP_Object_Access
)),
8614 (Build_In_Place_Formal
(Encl_Func
, BIP_Object_Access
),
8617 -- In the definite case, add an implicit actual to the function call
8618 -- that provides access to the declared object. An unchecked conversion
8619 -- to the (specific) result type of the function is inserted to handle
8620 -- the case where the object is declared with a class-wide type.
8624 Make_Unchecked_Type_Conversion
(Loc
,
8625 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
8626 Expression
=> New_Occurrence_Of
(Obj_Def_Id
, Loc
));
8628 -- When the function has a controlling result, an allocation-form
8629 -- parameter must be passed indicating that the caller is allocating
8630 -- the result object. This is needed because such a function can be
8631 -- called as a dispatching operation and must be treated similarly to
8632 -- functions with indefinite result subtypes.
8634 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8635 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8637 -- The allocation for indefinite library-level objects occurs on the
8638 -- heap as opposed to the secondary stack. This accommodates DLLs where
8639 -- the secondary stack is destroyed after each library unload. This is a
8640 -- hybrid mechanism where a stack-allocated object lives on the heap.
8642 elsif Is_Library_Level_Entity
(Obj_Def_Id
)
8643 and then not Restriction_Active
(No_Implicit_Heap_Allocations
)
8645 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8646 (Func_Call
, Function_Id
, Alloc_Form
=> Global_Heap
);
8647 Caller_Object
:= Empty
;
8649 -- Create a finalization master for the access result type to ensure
8650 -- that the heap allocation can properly chain the object and later
8651 -- finalize it when the library unit goes out of scope.
8653 if Needs_Finalization
(Etype
(Func_Call
)) then
8654 Build_Finalization_Master
8656 For_Lib_Level
=> True,
8657 Insertion_Node
=> Ptr_Typ_Decl
);
8660 Make_Attribute_Reference
(Loc
,
8662 New_Occurrence_Of
(Finalization_Master
(Ptr_Typ
), Loc
),
8663 Attribute_Name
=> Name_Unrestricted_Access
);
8666 -- In other indefinite cases, pass an indication to do the allocation
8667 -- on the secondary stack and set Caller_Object to Empty so that a null
8668 -- value will be passed for the caller's object address. A transient
8669 -- scope is established to ensure eventual cleanup of the result.
8672 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8673 (Func_Call
, Function_Id
, Alloc_Form
=> Secondary_Stack
);
8674 Caller_Object
:= Empty
;
8676 Establish_Transient_Scope
(Obj_Decl
, Manage_Sec_Stack
=> True);
8679 -- Pass along any finalization master actual, which is needed in the
8680 -- case where the called function initializes a return object of an
8681 -- enclosing build-in-place function.
8683 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8684 (Func_Call
=> Func_Call
,
8685 Func_Id
=> Function_Id
,
8686 Master_Exp
=> Fmaster_Actual
);
8688 if Nkind
(Parent
(Obj_Decl
)) = N_Extended_Return_Statement
8689 and then Has_Task
(Result_Subt
)
8691 -- Here we're passing along the master that was passed in to this
8694 Add_Task_Actuals_To_Build_In_Place_Call
8695 (Func_Call
, Function_Id
,
8698 (Build_In_Place_Formal
(Encl_Func
, BIP_Task_Master
), Loc
));
8701 Add_Task_Actuals_To_Build_In_Place_Call
8702 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8705 Add_Access_Actual_To_Build_In_Place_Call
8709 Is_Access
=> Pass_Caller_Acc
);
8711 -- Finally, create an access object initialized to a reference to the
8712 -- function call. We know this access value cannot be null, so mark the
8713 -- entity accordingly to suppress the access check.
8715 Def_Id
:= Make_Temporary
(Loc
, 'R', Func_Call
);
8716 Set_Etype
(Def_Id
, Ptr_Typ
);
8717 Set_Is_Known_Non_Null
(Def_Id
);
8719 if Nkind_In
(Function_Call
, N_Type_Conversion
,
8720 N_Unchecked_Type_Conversion
)
8723 Make_Object_Declaration
(Loc
,
8724 Defining_Identifier
=> Def_Id
,
8725 Constant_Present
=> True,
8726 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8728 Make_Unchecked_Type_Conversion
(Loc
,
8729 New_Occurrence_Of
(Ptr_Typ
, Loc
),
8730 Make_Reference
(Loc
, Relocate_Node
(Func_Call
))));
8733 Make_Object_Declaration
(Loc
,
8734 Defining_Identifier
=> Def_Id
,
8735 Constant_Present
=> True,
8736 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8738 Make_Reference
(Loc
, Relocate_Node
(Func_Call
)));
8741 Insert_After_And_Analyze
(Ptr_Typ_Decl
, Res_Decl
);
8743 -- If the result subtype of the called function is definite and is not
8744 -- itself the return expression of an enclosing BIP function, then mark
8745 -- the object as having no initialization.
8747 if Definite
and then not Is_Return_Object
(Obj_Def_Id
) then
8749 -- The related object declaration is encased in a transient block
8750 -- because the build-in-place function call contains at least one
8751 -- nested function call that produces a controlled transient
8754 -- Obj : ... := BIP_Func_Call (Ctrl_Func_Call);
8756 -- Since the build-in-place expansion decouples the call from the
8757 -- object declaration, the finalization machinery lacks the context
8758 -- which prompted the generation of the transient block. To resolve
8759 -- this scenario, store the build-in-place call.
8761 if Scope_Is_Transient
and then Node_To_Be_Wrapped
= Obj_Decl
then
8762 Set_BIP_Initialization_Call
(Obj_Def_Id
, Res_Decl
);
8765 Set_Expression
(Obj_Decl
, Empty
);
8766 Set_No_Initialization
(Obj_Decl
);
8768 -- In case of an indefinite result subtype, or if the call is the
8769 -- return expression of an enclosing BIP function, rewrite the object
8770 -- declaration as an object renaming where the renamed object is a
8771 -- dereference of <function_Call>'reference:
8773 -- Obj : Subt renames <function_call>'Ref.all;
8777 Make_Explicit_Dereference
(Obj_Loc
,
8778 Prefix
=> New_Occurrence_Of
(Def_Id
, Obj_Loc
));
8781 Make_Object_Renaming_Declaration
(Obj_Loc
,
8782 Defining_Identifier
=> Make_Temporary
(Obj_Loc
, 'D'),
8784 New_Occurrence_Of
(Designated_Type
, Obj_Loc
),
8785 Name
=> Call_Deref
));
8787 -- At this point, Defining_Identifier (Obj_Decl) is no longer equal
8790 Set_Renamed_Object
(Defining_Identifier
(Obj_Decl
), Call_Deref
);
8792 -- If the original entity comes from source, then mark the new
8793 -- entity as needing debug information, even though it's defined
8794 -- by a generated renaming that does not come from source, so that
8795 -- the Materialize_Entity flag will be set on the entity when
8796 -- Debug_Renaming_Declaration is called during analysis.
8798 if Comes_From_Source
(Obj_Def_Id
) then
8799 Set_Debug_Info_Needed
(Defining_Identifier
(Obj_Decl
));
8803 Replace_Renaming_Declaration_Id
8804 (Obj_Decl
, Original_Node
(Obj_Decl
));
8806 end Make_Build_In_Place_Call_In_Object_Declaration
;
8808 -------------------------------------------------
8809 -- Make_Build_In_Place_Iface_Call_In_Allocator --
8810 -------------------------------------------------
8812 procedure Make_Build_In_Place_Iface_Call_In_Allocator
8813 (Allocator
: Node_Id
;
8814 Function_Call
: Node_Id
)
8816 BIP_Func_Call
: constant Node_Id
:=
8817 Unqual_BIP_Iface_Function_Call
(Function_Call
);
8818 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8820 Anon_Type
: Entity_Id
;
8825 -- No action of the call has already been processed
8827 if Is_Expanded_Build_In_Place_Call
(BIP_Func_Call
) then
8831 Tmp_Id
:= Make_Temporary
(Loc
, 'D');
8833 -- Insert a temporary before N initialized with the BIP function call
8834 -- without its enclosing type conversions and analyze it without its
8835 -- expansion. This temporary facilitates us reusing the BIP machinery,
8836 -- which takes care of adding the extra build-in-place actuals and
8837 -- transforms this object declaration into an object renaming
8840 Anon_Type
:= Create_Itype
(E_Anonymous_Access_Type
, Function_Call
);
8841 Set_Directly_Designated_Type
(Anon_Type
, Etype
(BIP_Func_Call
));
8842 Set_Etype
(Anon_Type
, Anon_Type
);
8845 Make_Object_Declaration
(Loc
,
8846 Defining_Identifier
=> Tmp_Id
,
8847 Object_Definition
=> New_Occurrence_Of
(Anon_Type
, Loc
),
8849 Make_Allocator
(Loc
,
8851 Make_Qualified_Expression
(Loc
,
8853 New_Occurrence_Of
(Etype
(BIP_Func_Call
), Loc
),
8854 Expression
=> New_Copy_Tree
(BIP_Func_Call
))));
8856 Expander_Mode_Save_And_Set
(False);
8857 Insert_Action
(Allocator
, Tmp_Decl
);
8858 Expander_Mode_Restore
;
8860 Make_Build_In_Place_Call_In_Allocator
8861 (Allocator
=> Expression
(Tmp_Decl
),
8862 Function_Call
=> Expression
(Expression
(Tmp_Decl
)));
8864 Rewrite
(Allocator
, New_Occurrence_Of
(Tmp_Id
, Loc
));
8865 end Make_Build_In_Place_Iface_Call_In_Allocator
;
8867 ---------------------------------------------------------
8868 -- Make_Build_In_Place_Iface_Call_In_Anonymous_Context --
8869 ---------------------------------------------------------
8871 procedure Make_Build_In_Place_Iface_Call_In_Anonymous_Context
8872 (Function_Call
: Node_Id
)
8874 BIP_Func_Call
: constant Node_Id
:=
8875 Unqual_BIP_Iface_Function_Call
(Function_Call
);
8876 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8882 -- No action of the call has already been processed
8884 if Is_Expanded_Build_In_Place_Call
(BIP_Func_Call
) then
8888 pragma Assert
(Needs_Finalization
(Etype
(BIP_Func_Call
)));
8890 -- Insert a temporary before the call initialized with function call to
8891 -- reuse the BIP machinery which takes care of adding the extra build-in
8892 -- place actuals and transforms this object declaration into an object
8893 -- renaming declaration.
8895 Tmp_Id
:= Make_Temporary
(Loc
, 'D');
8898 Make_Object_Declaration
(Loc
,
8899 Defining_Identifier
=> Tmp_Id
,
8900 Object_Definition
=>
8901 New_Occurrence_Of
(Etype
(Function_Call
), Loc
),
8902 Expression
=> Relocate_Node
(Function_Call
));
8904 Expander_Mode_Save_And_Set
(False);
8905 Insert_Action
(Function_Call
, Tmp_Decl
);
8906 Expander_Mode_Restore
;
8908 Make_Build_In_Place_Iface_Call_In_Object_Declaration
8909 (Obj_Decl
=> Tmp_Decl
,
8910 Function_Call
=> Expression
(Tmp_Decl
));
8911 end Make_Build_In_Place_Iface_Call_In_Anonymous_Context
;
8913 ----------------------------------------------------------
8914 -- Make_Build_In_Place_Iface_Call_In_Object_Declaration --
8915 ----------------------------------------------------------
8917 procedure Make_Build_In_Place_Iface_Call_In_Object_Declaration
8918 (Obj_Decl
: Node_Id
;
8919 Function_Call
: Node_Id
)
8921 BIP_Func_Call
: constant Node_Id
:=
8922 Unqual_BIP_Iface_Function_Call
(Function_Call
);
8923 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8924 Obj_Id
: constant Entity_Id
:= Defining_Entity
(Obj_Decl
);
8930 -- No action of the call has already been processed
8932 if Is_Expanded_Build_In_Place_Call
(BIP_Func_Call
) then
8936 Tmp_Id
:= Make_Temporary
(Loc
, 'D');
8938 -- Insert a temporary before N initialized with the BIP function call
8939 -- without its enclosing type conversions and analyze it without its
8940 -- expansion. This temporary facilitates us reusing the BIP machinery,
8941 -- which takes care of adding the extra build-in-place actuals and
8942 -- transforms this object declaration into an object renaming
8946 Make_Object_Declaration
(Loc
,
8947 Defining_Identifier
=> Tmp_Id
,
8948 Object_Definition
=>
8949 New_Occurrence_Of
(Etype
(BIP_Func_Call
), Loc
),
8950 Expression
=> New_Copy_Tree
(BIP_Func_Call
));
8952 Expander_Mode_Save_And_Set
(False);
8953 Insert_Action
(Obj_Decl
, Tmp_Decl
);
8954 Expander_Mode_Restore
;
8956 Make_Build_In_Place_Call_In_Object_Declaration
8957 (Obj_Decl
=> Tmp_Decl
,
8958 Function_Call
=> Expression
(Tmp_Decl
));
8960 pragma Assert
(Nkind
(Tmp_Decl
) = N_Object_Renaming_Declaration
);
8962 -- Replace the original build-in-place function call by a reference to
8963 -- the resulting temporary object renaming declaration. In this way,
8964 -- all the interface conversions performed in the original Function_Call
8965 -- on the build-in-place object are preserved.
8967 Rewrite
(BIP_Func_Call
, New_Occurrence_Of
(Tmp_Id
, Loc
));
8969 -- Replace the original object declaration by an internal object
8970 -- renaming declaration. This leaves the generated code more clean (the
8971 -- build-in-place function call in an object renaming declaration and
8972 -- displacements of the pointer to the build-in-place object in another
8973 -- renaming declaration) and allows us to invoke the routine that takes
8974 -- care of replacing the identifier of the renaming declaration (routine
8975 -- originally developed for the regular build-in-place management).
8978 Make_Object_Renaming_Declaration
(Loc
,
8979 Defining_Identifier
=> Make_Temporary
(Loc
, 'D'),
8980 Subtype_Mark
=> New_Occurrence_Of
(Etype
(Obj_Id
), Loc
),
8981 Name
=> Function_Call
));
8984 Replace_Renaming_Declaration_Id
(Obj_Decl
, Original_Node
(Obj_Decl
));
8985 end Make_Build_In_Place_Iface_Call_In_Object_Declaration
;
8987 --------------------------------------------
8988 -- Make_CPP_Constructor_Call_In_Allocator --
8989 --------------------------------------------
8991 procedure Make_CPP_Constructor_Call_In_Allocator
8992 (Allocator
: Node_Id
;
8993 Function_Call
: Node_Id
)
8995 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8996 Acc_Type
: constant Entity_Id
:= Etype
(Allocator
);
8997 Function_Id
: constant Entity_Id
:= Entity
(Name
(Function_Call
));
8998 Result_Subt
: constant Entity_Id
:= Available_View
(Etype
(Function_Id
));
9000 New_Allocator
: Node_Id
;
9001 Return_Obj_Access
: Entity_Id
;
9005 pragma Assert
(Nkind
(Allocator
) = N_Allocator
9006 and then Nkind
(Function_Call
) = N_Function_Call
);
9007 pragma Assert
(Convention
(Function_Id
) = Convention_CPP
9008 and then Is_Constructor
(Function_Id
));
9009 pragma Assert
(Is_Constrained
(Underlying_Type
(Result_Subt
)));
9011 -- Replace the initialized allocator of form "new T'(Func (...))" with
9012 -- an uninitialized allocator of form "new T", where T is the result
9013 -- subtype of the called function. The call to the function is handled
9014 -- separately further below.
9017 Make_Allocator
(Loc
,
9018 Expression
=> New_Occurrence_Of
(Result_Subt
, Loc
));
9019 Set_No_Initialization
(New_Allocator
);
9021 -- Copy attributes to new allocator. Note that the new allocator
9022 -- logically comes from source if the original one did, so copy the
9023 -- relevant flag. This ensures proper treatment of the restriction
9024 -- No_Implicit_Heap_Allocations in this case.
9026 Set_Storage_Pool
(New_Allocator
, Storage_Pool
(Allocator
));
9027 Set_Procedure_To_Call
(New_Allocator
, Procedure_To_Call
(Allocator
));
9028 Set_Comes_From_Source
(New_Allocator
, Comes_From_Source
(Allocator
));
9030 Rewrite
(Allocator
, New_Allocator
);
9032 -- Create a new access object and initialize it to the result of the
9033 -- new uninitialized allocator. Note: we do not use Allocator as the
9034 -- Related_Node of Return_Obj_Access in call to Make_Temporary below
9035 -- as this would create a sort of infinite "recursion".
9037 Return_Obj_Access
:= Make_Temporary
(Loc
, 'R');
9038 Set_Etype
(Return_Obj_Access
, Acc_Type
);
9041 -- Rnnn : constant ptr_T := new (T);
9042 -- Init (Rnn.all,...);
9045 Make_Object_Declaration
(Loc
,
9046 Defining_Identifier
=> Return_Obj_Access
,
9047 Constant_Present
=> True,
9048 Object_Definition
=> New_Occurrence_Of
(Acc_Type
, Loc
),
9049 Expression
=> Relocate_Node
(Allocator
));
9050 Insert_Action
(Allocator
, Tmp_Obj
);
9052 Insert_List_After_And_Analyze
(Tmp_Obj
,
9053 Build_Initialization_Call
(Loc
,
9055 Make_Explicit_Dereference
(Loc
,
9056 Prefix
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
)),
9057 Typ
=> Etype
(Function_Id
),
9058 Constructor_Ref
=> Function_Call
));
9060 -- Finally, replace the allocator node with a reference to the result of
9061 -- the function call itself (which will effectively be an access to the
9062 -- object created by the allocator).
9064 Rewrite
(Allocator
, New_Occurrence_Of
(Return_Obj_Access
, Loc
));
9066 -- Ada 2005 (AI-251): If the type of the allocator is an interface then
9067 -- generate an implicit conversion to force displacement of the "this"
9070 if Is_Interface
(Designated_Type
(Acc_Type
)) then
9071 Rewrite
(Allocator
, Convert_To
(Acc_Type
, Relocate_Node
(Allocator
)));
9074 Analyze_And_Resolve
(Allocator
, Acc_Type
);
9075 end Make_CPP_Constructor_Call_In_Allocator
;
9077 -----------------------------------
9078 -- Needs_BIP_Finalization_Master --
9079 -----------------------------------
9081 function Needs_BIP_Finalization_Master
9082 (Func_Id
: Entity_Id
) return Boolean
9084 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
9085 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
9087 -- A formal giving the finalization master is needed for build-in-place
9088 -- functions whose result type needs finalization or is a tagged type.
9089 -- Tagged primitive build-in-place functions need such a formal because
9090 -- they can be called by a dispatching call, and extensions may require
9091 -- finalization even if the root type doesn't. This means they're also
9092 -- needed for tagged nonprimitive build-in-place functions with tagged
9093 -- results, since such functions can be called via access-to-function
9094 -- types, and those can be used to call primitives, so masters have to
9095 -- be passed to all such build-in-place functions, primitive or not.
9098 not Restriction_Active
(No_Finalization
)
9099 and then (Needs_Finalization
(Func_Typ
)
9100 or else Is_Tagged_Type
(Func_Typ
));
9101 end Needs_BIP_Finalization_Master
;
9103 --------------------------
9104 -- Needs_BIP_Alloc_Form --
9105 --------------------------
9107 function Needs_BIP_Alloc_Form
(Func_Id
: Entity_Id
) return Boolean is
9108 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
9109 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
9112 -- A build-in-place function needs to know which allocation form to
9115 -- 1) The result subtype is unconstrained. In this case, depending on
9116 -- the context of the call, the object may need to be created in the
9117 -- secondary stack, the heap, or a user-defined storage pool.
9119 -- 2) The result subtype is tagged. In this case the function call may
9120 -- dispatch on result and thus needs to be treated in the same way as
9121 -- calls to functions with class-wide results, because a callee that
9122 -- can be dispatched to may have any of various result subtypes, so
9123 -- if any of the possible callees would require an allocation form to
9124 -- be passed then they all do.
9126 -- 3) The result subtype needs finalization actions. In this case, based
9127 -- on the context of the call, the object may need to be created at
9128 -- the caller site, in the heap, or in a user-defined storage pool.
9131 not Is_Constrained
(Func_Typ
)
9132 or else Is_Tagged_Type
(Func_Typ
)
9133 or else Needs_Finalization
(Func_Typ
);
9134 end Needs_BIP_Alloc_Form
;
9136 --------------------------------------
9137 -- Needs_Result_Accessibility_Level --
9138 --------------------------------------
9140 function Needs_Result_Accessibility_Level
9141 (Func_Id
: Entity_Id
) return Boolean
9143 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
9145 function Has_Unconstrained_Access_Discriminant_Component
9146 (Comp_Typ
: Entity_Id
) return Boolean;
9147 -- Returns True if any component of the type has an unconstrained access
9150 -----------------------------------------------------
9151 -- Has_Unconstrained_Access_Discriminant_Component --
9152 -----------------------------------------------------
9154 function Has_Unconstrained_Access_Discriminant_Component
9155 (Comp_Typ
: Entity_Id
) return Boolean
9158 if not Is_Limited_Type
(Comp_Typ
) then
9161 -- Only limited types can have access discriminants with
9164 elsif Has_Unconstrained_Access_Discriminants
(Comp_Typ
) then
9167 elsif Is_Array_Type
(Comp_Typ
) then
9168 return Has_Unconstrained_Access_Discriminant_Component
9169 (Underlying_Type
(Component_Type
(Comp_Typ
)));
9171 elsif Is_Record_Type
(Comp_Typ
) then
9176 Comp
:= First_Component
(Comp_Typ
);
9177 while Present
(Comp
) loop
9178 if Has_Unconstrained_Access_Discriminant_Component
9179 (Underlying_Type
(Etype
(Comp
)))
9184 Next_Component
(Comp
);
9190 end Has_Unconstrained_Access_Discriminant_Component
;
9192 Feature_Disabled
: constant Boolean := True;
9195 -- Start of processing for Needs_Result_Accessibility_Level
9198 -- False if completion unavailable (how does this happen???)
9200 if not Present
(Func_Typ
) then
9203 elsif Feature_Disabled
then
9206 -- False if not a function, also handle enum-lit renames case
9208 elsif Func_Typ
= Standard_Void_Type
9209 or else Is_Scalar_Type
(Func_Typ
)
9213 -- Handle a corner case, a cross-dialect subp renaming. For example,
9214 -- an Ada 2012 renaming of an Ada 2005 subprogram. This can occur when
9215 -- an Ada 2005 (or earlier) unit references predefined run-time units.
9217 elsif Present
(Alias
(Func_Id
)) then
9219 -- Unimplemented: a cross-dialect subp renaming which does not set
9220 -- the Alias attribute (e.g., a rename of a dereference of an access
9221 -- to subprogram value). ???
9223 return Present
(Extra_Accessibility_Of_Result
(Alias
(Func_Id
)));
9225 -- Remaining cases require Ada 2012 mode
9227 elsif Ada_Version
< Ada_2012
then
9230 elsif Ekind
(Func_Typ
) = E_Anonymous_Access_Type
9231 or else Is_Tagged_Type
(Func_Typ
)
9233 -- In the case of, say, a null tagged record result type, the need
9234 -- for this extra parameter might not be obvious. This function
9235 -- returns True for all tagged types for compatibility reasons.
9236 -- A function with, say, a tagged null controlling result type might
9237 -- be overridden by a primitive of an extension having an access
9238 -- discriminant and the overrider and overridden must have compatible
9239 -- calling conventions (including implicitly declared parameters).
9240 -- Similarly, values of one access-to-subprogram type might designate
9241 -- both a primitive subprogram of a given type and a function
9242 -- which is, for example, not a primitive subprogram of any type.
9243 -- Again, this requires calling convention compatibility.
9244 -- It might be possible to solve these issues by introducing
9245 -- wrappers, but that is not the approach that was chosen.
9249 elsif Has_Unconstrained_Access_Discriminants
(Func_Typ
) then
9252 elsif Has_Unconstrained_Access_Discriminant_Component
(Func_Typ
) then
9255 -- False for all other cases
9260 end Needs_Result_Accessibility_Level
;
9262 -------------------------------------
9263 -- Replace_Renaming_Declaration_Id --
9264 -------------------------------------
9266 procedure Replace_Renaming_Declaration_Id
9267 (New_Decl
: Node_Id
;
9268 Orig_Decl
: Node_Id
)
9270 New_Id
: constant Entity_Id
:= Defining_Entity
(New_Decl
);
9271 Orig_Id
: constant Entity_Id
:= Defining_Entity
(Orig_Decl
);
9274 Set_Chars
(New_Id
, Chars
(Orig_Id
));
9276 -- Swap next entity links in preparation for exchanging entities
9279 Next_Id
: constant Entity_Id
:= Next_Entity
(New_Id
);
9281 Link_Entities
(New_Id
, Next_Entity
(Orig_Id
));
9282 Link_Entities
(Orig_Id
, Next_Id
);
9285 Set_Homonym
(New_Id
, Homonym
(Orig_Id
));
9286 Exchange_Entities
(New_Id
, Orig_Id
);
9288 -- Preserve source indication of original declaration, so that xref
9289 -- information is properly generated for the right entity.
9291 Preserve_Comes_From_Source
(New_Decl
, Orig_Decl
);
9292 Preserve_Comes_From_Source
(Orig_Id
, Orig_Decl
);
9294 Set_Comes_From_Source
(New_Id
, False);
9295 end Replace_Renaming_Declaration_Id
;
9297 ---------------------------------
9298 -- Rewrite_Function_Call_For_C --
9299 ---------------------------------
9301 procedure Rewrite_Function_Call_For_C
(N
: Node_Id
) is
9302 Orig_Func
: constant Entity_Id
:= Entity
(Name
(N
));
9303 Func_Id
: constant Entity_Id
:= Ultimate_Alias
(Orig_Func
);
9304 Par
: constant Node_Id
:= Parent
(N
);
9305 Proc_Id
: constant Entity_Id
:= Corresponding_Procedure
(Func_Id
);
9306 Loc
: constant Source_Ptr
:= Sloc
(Par
);
9308 Last_Actual
: Node_Id
;
9309 Last_Formal
: Entity_Id
;
9311 -- Start of processing for Rewrite_Function_Call_For_C
9314 -- The actuals may be given by named associations, so the added actual
9315 -- that is the target of the return value of the call must be a named
9316 -- association as well, so we retrieve the name of the generated
9319 Last_Formal
:= First_Formal
(Proc_Id
);
9320 while Present
(Next_Formal
(Last_Formal
)) loop
9321 Last_Formal
:= Next_Formal
(Last_Formal
);
9324 Actuals
:= Parameter_Associations
(N
);
9326 -- The original function may lack parameters
9328 if No
(Actuals
) then
9329 Actuals
:= New_List
;
9332 -- If the function call is the expression of an assignment statement,
9333 -- transform the assignment into a procedure call. Generate:
9335 -- LHS := Func_Call (...);
9337 -- Proc_Call (..., LHS);
9339 -- If function is inherited, a conversion may be necessary.
9341 if Nkind
(Par
) = N_Assignment_Statement
then
9342 Last_Actual
:= Name
(Par
);
9344 if not Comes_From_Source
(Orig_Func
)
9345 and then Etype
(Orig_Func
) /= Etype
(Func_Id
)
9348 Make_Type_Conversion
(Loc
,
9349 New_Occurrence_Of
(Etype
(Func_Id
), Loc
),
9354 Make_Parameter_Association
(Loc
,
9356 Make_Identifier
(Loc
, Chars
(Last_Formal
)),
9357 Explicit_Actual_Parameter
=> Last_Actual
));
9360 Make_Procedure_Call_Statement
(Loc
,
9361 Name
=> New_Occurrence_Of
(Proc_Id
, Loc
),
9362 Parameter_Associations
=> Actuals
));
9365 -- Otherwise the context is an expression. Generate a temporary and a
9366 -- procedure call to obtain the function result. Generate:
9368 -- ... Func_Call (...) ...
9371 -- Proc_Call (..., Temp);
9376 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
9385 Make_Object_Declaration
(Loc
,
9386 Defining_Identifier
=> Temp_Id
,
9387 Object_Definition
=>
9388 New_Occurrence_Of
(Etype
(Func_Id
), Loc
));
9391 -- Proc_Call (..., Temp);
9394 Make_Parameter_Association
(Loc
,
9396 Make_Identifier
(Loc
, Chars
(Last_Formal
)),
9397 Explicit_Actual_Parameter
=>
9398 New_Occurrence_Of
(Temp_Id
, Loc
)));
9401 Make_Procedure_Call_Statement
(Loc
,
9402 Name
=> New_Occurrence_Of
(Proc_Id
, Loc
),
9403 Parameter_Associations
=> Actuals
);
9405 Insert_Actions
(Par
, New_List
(Decl
, Call
));
9406 Rewrite
(N
, New_Occurrence_Of
(Temp_Id
, Loc
));
9409 end Rewrite_Function_Call_For_C
;
9411 ------------------------------------
9412 -- Set_Enclosing_Sec_Stack_Return --
9413 ------------------------------------
9415 procedure Set_Enclosing_Sec_Stack_Return
(N
: Node_Id
) is
9419 -- Due to a possible mix of internally generated blocks, source blocks
9420 -- and loops, the scope stack may not be contiguous as all labels are
9421 -- inserted at the top level within the related function. Instead,
9422 -- perform a parent-based traversal and mark all appropriate constructs.
9424 while Present
(P
) loop
9426 -- Mark the label of a source or internally generated block or
9429 if Nkind_In
(P
, N_Block_Statement
, N_Loop_Statement
) then
9430 Set_Sec_Stack_Needed_For_Return
(Entity
(Identifier
(P
)));
9432 -- Mark the enclosing function
9434 elsif Nkind
(P
) = N_Subprogram_Body
then
9435 if Present
(Corresponding_Spec
(P
)) then
9436 Set_Sec_Stack_Needed_For_Return
(Corresponding_Spec
(P
));
9438 Set_Sec_Stack_Needed_For_Return
(Defining_Entity
(P
));
9441 -- Do not go beyond the enclosing function
9448 end Set_Enclosing_Sec_Stack_Return
;
9450 ------------------------------------
9451 -- Unqual_BIP_Iface_Function_Call --
9452 ------------------------------------
9454 function Unqual_BIP_Iface_Function_Call
(Expr
: Node_Id
) return Node_Id
is
9455 Has_Pointer_Displacement
: Boolean := False;
9456 On_Object_Declaration
: Boolean := False;
9457 -- Remember if processing the renaming expressions on recursion we have
9458 -- traversed an object declaration, since we can traverse many object
9459 -- declaration renamings but just one regular object declaration.
9461 function Unqual_BIP_Function_Call
(Expr
: Node_Id
) return Node_Id
;
9462 -- Search for a build-in-place function call skipping any qualification
9463 -- including qualified expressions, type conversions, references, calls
9464 -- to displace the pointer to the object, and renamings. Return Empty if
9465 -- no build-in-place function call is found.
9467 ------------------------------
9468 -- Unqual_BIP_Function_Call --
9469 ------------------------------
9471 function Unqual_BIP_Function_Call
(Expr
: Node_Id
) return Node_Id
is
9473 -- Recurse to handle case of multiple levels of qualification and/or
9476 if Nkind_In
(Expr
, N_Qualified_Expression
,
9478 N_Unchecked_Type_Conversion
)
9480 return Unqual_BIP_Function_Call
(Expression
(Expr
));
9482 -- Recurse to handle case of multiple levels of references and
9483 -- explicit dereferences.
9485 elsif Nkind_In
(Expr
, N_Attribute_Reference
,
9486 N_Explicit_Dereference
,
9489 return Unqual_BIP_Function_Call
(Prefix
(Expr
));
9491 -- Recurse on object renamings
9493 elsif Nkind
(Expr
) = N_Identifier
9494 and then Present
(Entity
(Expr
))
9495 and then Ekind_In
(Entity
(Expr
), E_Constant
, E_Variable
)
9496 and then Nkind
(Parent
(Entity
(Expr
))) =
9497 N_Object_Renaming_Declaration
9498 and then Present
(Renamed_Object
(Entity
(Expr
)))
9500 return Unqual_BIP_Function_Call
(Renamed_Object
(Entity
(Expr
)));
9502 -- Recurse on the initializing expression of the first reference of
9503 -- an object declaration.
9505 elsif not On_Object_Declaration
9506 and then Nkind
(Expr
) = N_Identifier
9507 and then Present
(Entity
(Expr
))
9508 and then Ekind_In
(Entity
(Expr
), E_Constant
, E_Variable
)
9509 and then Nkind
(Parent
(Entity
(Expr
))) = N_Object_Declaration
9510 and then Present
(Expression
(Parent
(Entity
(Expr
))))
9512 On_Object_Declaration
:= True;
9514 Unqual_BIP_Function_Call
(Expression
(Parent
(Entity
(Expr
))));
9516 -- Recurse to handle calls to displace the pointer to the object to
9517 -- reference a secondary dispatch table.
9519 elsif Nkind
(Expr
) = N_Function_Call
9520 and then Nkind
(Name
(Expr
)) in N_Has_Entity
9521 and then Present
(Entity
(Name
(Expr
)))
9522 and then RTU_Loaded
(Ada_Tags
)
9523 and then RTE_Available
(RE_Displace
)
9524 and then Is_RTE
(Entity
(Name
(Expr
)), RE_Displace
)
9526 Has_Pointer_Displacement
:= True;
9528 Unqual_BIP_Function_Call
(First
(Parameter_Associations
(Expr
)));
9530 -- Normal case: check if the inner expression is a BIP function call
9531 -- and the pointer to the object is displaced.
9533 elsif Has_Pointer_Displacement
9534 and then Is_Build_In_Place_Function_Call
(Expr
)
9541 end Unqual_BIP_Function_Call
;
9543 -- Start of processing for Unqual_BIP_Iface_Function_Call
9546 if Nkind
(Expr
) = N_Identifier
and then No
(Entity
(Expr
)) then
9548 -- Can happen for X'Elab_Spec in the binder-generated file
9553 return Unqual_BIP_Function_Call
(Expr
);
9554 end Unqual_BIP_Iface_Function_Call
;