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 the formal is an out parameter with discriminants, the
1325 -- discriminants must be captured even if the rest of the object
1326 -- is in principle uninitialized, because the discriminants may
1327 -- be read by the called subprogram.
1329 if Ekind
(Formal
) = E_In_Out_Parameter
1330 or else (Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
))
1331 or else Has_Discriminants
(F_Typ
)
1333 if Nkind
(Actual
) = N_Type_Conversion
then
1334 if Conversion_OK
(Actual
) then
1335 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1337 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1340 elsif Ekind
(Formal
) = E_Out_Parameter
1341 and then Is_Array_Type
(F_Typ
)
1342 and then Number_Dimensions
(F_Typ
) = 1
1343 and then not Has_Non_Null_Base_Init_Proc
(F_Typ
)
1345 -- Actual is a one-dimensional array or slice, and the type
1346 -- requires no initialization. Create a temporary of the
1347 -- right size, but do not copy actual into it (optimization).
1351 Make_Subtype_Indication
(Loc
,
1352 Subtype_Mark
=> New_Occurrence_Of
(F_Typ
, Loc
),
1354 Make_Index_Or_Discriminant_Constraint
(Loc
,
1355 Constraints
=> New_List
(
1358 Make_Attribute_Reference
(Loc
,
1359 Prefix
=> New_Occurrence_Of
(Var
, Loc
),
1360 Attribute_Name
=> Name_First
),
1362 Make_Attribute_Reference
(Loc
,
1363 Prefix
=> New_Occurrence_Of
(Var
, Loc
),
1364 Attribute_Name
=> Name_Last
)))));
1367 Init
:= New_Occurrence_Of
(Var
, Loc
);
1370 -- An initialization is created for packed conversions as
1371 -- actuals for out parameters to enable Make_Object_Declaration
1372 -- to determine the proper subtype for N_Node. Note that this
1373 -- is wasteful because the extra copying on the call side is
1374 -- not required for such out parameters. ???
1376 elsif Ekind
(Formal
) = E_Out_Parameter
1377 and then Nkind
(Actual
) = N_Type_Conversion
1378 and then (Is_Bit_Packed_Array
(F_Typ
)
1380 Is_Bit_Packed_Array
(Etype
(Expression
(Actual
))))
1382 if Conversion_OK
(Actual
) then
1383 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1385 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1388 elsif Ekind
(Formal
) = E_In_Parameter
then
1390 -- Handle the case in which the actual is a type conversion
1392 if Nkind
(Actual
) = N_Type_Conversion
then
1393 if Conversion_OK
(Actual
) then
1394 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1396 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1399 Init
:= New_Occurrence_Of
(Var
, Loc
);
1407 Make_Object_Declaration
(Loc
,
1408 Defining_Identifier
=> Temp
,
1409 Object_Definition
=> Indic
,
1410 Expression
=> Init
);
1411 Set_Assignment_OK
(N_Node
);
1412 Insert_Action
(N
, N_Node
);
1414 -- Now, normally the deal here is that we use the defining
1415 -- identifier created by that object declaration. There is
1416 -- one exception to this. In the change of representation case
1417 -- the above declaration will end up looking like:
1419 -- temp : type := identifier;
1421 -- And in this case we might as well use the identifier directly
1422 -- and eliminate the temporary. Note that the analysis of the
1423 -- declaration was not a waste of time in that case, since it is
1424 -- what generated the necessary change of representation code. If
1425 -- the change of representation introduced additional code, as in
1426 -- a fixed-integer conversion, the expression is not an identifier
1427 -- and must be kept.
1430 and then Present
(Expression
(N_Node
))
1431 and then Is_Entity_Name
(Expression
(N_Node
))
1433 Temp
:= Entity
(Expression
(N_Node
));
1434 Rewrite
(N_Node
, Make_Null_Statement
(Loc
));
1437 -- For IN parameter, all we do is to replace the actual
1439 if Ekind
(Formal
) = E_In_Parameter
then
1440 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1443 -- Processing for OUT or IN OUT parameter
1446 -- Kill current value indications for the temporary variable we
1447 -- created, since we just passed it as an OUT parameter.
1449 Kill_Current_Values
(Temp
);
1450 Set_Is_Known_Valid
(Temp
, False);
1451 Set_Is_True_Constant
(Temp
, False);
1453 -- If type conversion, use reverse conversion on exit
1455 if Nkind
(Actual
) = N_Type_Conversion
then
1456 if Conversion_OK
(Actual
) then
1457 Expr
:= OK_Convert_To
(V_Typ
, New_Occurrence_Of
(Temp
, Loc
));
1459 Expr
:= Convert_To
(V_Typ
, New_Occurrence_Of
(Temp
, Loc
));
1462 Expr
:= New_Occurrence_Of
(Temp
, Loc
);
1465 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1468 -- If the actual is a conversion of a packed reference, it may
1469 -- already have been expanded by Remove_Side_Effects, and the
1470 -- resulting variable is a temporary which does not designate
1471 -- the proper out-parameter, which may not be addressable. In
1472 -- that case, generate an assignment to the original expression
1473 -- (before expansion of the packed reference) so that the proper
1474 -- expansion of assignment to a packed component can take place.
1481 if Is_Renaming_Of_Object
(Var
)
1482 and then Nkind
(Renamed_Object
(Var
)) = N_Selected_Component
1483 and then Nkind
(Original_Node
(Prefix
(Renamed_Object
(Var
))))
1484 = N_Indexed_Component
1486 Has_Non_Standard_Rep
(Etype
(Prefix
(Renamed_Object
(Var
))))
1488 Obj
:= Renamed_Object
(Var
);
1490 Make_Selected_Component
(Loc
,
1492 New_Copy_Tree
(Original_Node
(Prefix
(Obj
))),
1493 Selector_Name
=> New_Copy
(Selector_Name
(Obj
)));
1494 Reset_Analyzed_Flags
(Lhs
);
1497 Lhs
:= New_Occurrence_Of
(Var
, Loc
);
1500 Set_Assignment_OK
(Lhs
);
1502 if Is_Access_Type
(E_Formal
)
1503 and then Is_Entity_Name
(Lhs
)
1505 Present
(Effective_Extra_Accessibility
(Entity
(Lhs
)))
1507 -- Copyback target is an Ada 2012 stand-alone object of an
1508 -- anonymous access type.
1510 pragma Assert
(Ada_Version
>= Ada_2012
);
1512 if Type_Access_Level
(E_Formal
) >
1513 Object_Access_Level
(Lhs
)
1515 Append_To
(Post_Call
,
1516 Make_Raise_Program_Error
(Loc
,
1517 Reason
=> PE_Accessibility_Check_Failed
));
1520 Append_To
(Post_Call
,
1521 Make_Assignment_Statement
(Loc
,
1523 Expression
=> Expr
));
1525 -- We would like to somehow suppress generation of the
1526 -- extra_accessibility assignment generated by the expansion
1527 -- of the above assignment statement. It's not a correctness
1528 -- issue because the following assignment renders it dead,
1529 -- but generating back-to-back assignments to the same
1530 -- target is undesirable. ???
1532 Append_To
(Post_Call
,
1533 Make_Assignment_Statement
(Loc
,
1534 Name
=> New_Occurrence_Of
(
1535 Effective_Extra_Accessibility
(Entity
(Lhs
)), Loc
),
1536 Expression
=> Make_Integer_Literal
(Loc
,
1537 Type_Access_Level
(E_Formal
))));
1540 Append_To
(Post_Call
,
1541 Make_Assignment_Statement
(Loc
,
1543 Expression
=> Expr
));
1547 end Add_Call_By_Copy_Code
;
1549 ----------------------------------
1550 -- Add_Simple_Call_By_Copy_Code --
1551 ----------------------------------
1553 procedure Add_Simple_Call_By_Copy_Code
is
1555 F_Typ
: Entity_Id
:= Etype
(Formal
);
1564 if not Is_Legal_Copy
then
1568 -- Handle formals whose type comes from the limited view
1570 if From_Limited_With
(F_Typ
)
1571 and then Has_Non_Limited_View
(F_Typ
)
1573 F_Typ
:= Non_Limited_View
(F_Typ
);
1576 -- Use formal type for temp, unless formal type is an unconstrained
1577 -- array, in which case we don't have to worry about bounds checks,
1578 -- and we use the actual type, since that has appropriate bounds.
1580 if Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
) then
1581 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1583 Indic
:= New_Occurrence_Of
(F_Typ
, Loc
);
1586 -- Prepare to generate code
1588 Reset_Packed_Prefix
;
1590 Temp
:= Make_Temporary
(Loc
, 'T', Actual
);
1591 Incod
:= Relocate_Node
(Actual
);
1592 Outcod
:= New_Copy_Tree
(Incod
);
1594 -- Generate declaration of temporary variable, initializing it
1595 -- with the input parameter unless we have an OUT formal or
1596 -- this is an initialization call.
1598 -- If the formal is an out parameter with discriminants, the
1599 -- discriminants must be captured even if the rest of the object
1600 -- is in principle uninitialized, because the discriminants may
1601 -- be read by the called subprogram.
1603 if Ekind
(Formal
) = E_Out_Parameter
then
1606 if Has_Discriminants
(F_Typ
) then
1607 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1610 elsif Inside_Init_Proc
then
1612 -- Could use a comment here to match comment below ???
1614 if Nkind
(Actual
) /= N_Selected_Component
1616 not Has_Discriminant_Dependent_Constraint
1617 (Entity
(Selector_Name
(Actual
)))
1621 -- Otherwise, keep the component in order to generate the proper
1622 -- actual subtype, that depends on enclosing discriminants.
1630 Make_Object_Declaration
(Loc
,
1631 Defining_Identifier
=> Temp
,
1632 Object_Definition
=> Indic
,
1633 Expression
=> Incod
);
1638 -- If the call is to initialize a component of a composite type,
1639 -- and the component does not depend on discriminants, use the
1640 -- actual type of the component. This is required in case the
1641 -- component is constrained, because in general the formal of the
1642 -- initialization procedure will be unconstrained. Note that if
1643 -- the component being initialized is constrained by an enclosing
1644 -- discriminant, the presence of the initialization in the
1645 -- declaration will generate an expression for the actual subtype.
1647 Set_No_Initialization
(Decl
);
1648 Set_Object_Definition
(Decl
,
1649 New_Occurrence_Of
(Etype
(Actual
), Loc
));
1652 Insert_Action
(N
, Decl
);
1654 -- The actual is simply a reference to the temporary
1656 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1658 -- Generate copy out if OUT or IN OUT parameter
1660 if Ekind
(Formal
) /= E_In_Parameter
then
1662 Rhs
:= New_Occurrence_Of
(Temp
, Loc
);
1663 Set_Is_True_Constant
(Temp
, False);
1665 -- Deal with conversion
1667 if Nkind
(Lhs
) = N_Type_Conversion
then
1668 Lhs
:= Expression
(Lhs
);
1669 Rhs
:= Convert_To
(Etype
(Actual
), Rhs
);
1672 Append_To
(Post_Call
,
1673 Make_Assignment_Statement
(Loc
,
1675 Expression
=> Rhs
));
1676 Set_Assignment_OK
(Name
(Last
(Post_Call
)));
1678 end Add_Simple_Call_By_Copy_Code
;
1680 --------------------------------------
1681 -- Add_Validation_Call_By_Copy_Code --
1682 --------------------------------------
1684 procedure Add_Validation_Call_By_Copy_Code
(Act
: Node_Id
) is
1687 Obj_Typ
: Entity_Id
;
1688 Var
: constant Node_Id
:= Unqual_Conv
(Act
);
1692 -- Copy the value of the validation variable back into the object
1695 if Is_Entity_Name
(Var
) then
1696 Var_Id
:= Entity
(Var
);
1697 Obj
:= Validated_Object
(Var_Id
);
1698 Obj_Typ
:= Etype
(Obj
);
1700 Expr
:= New_Occurrence_Of
(Var_Id
, Loc
);
1702 -- A type conversion is needed when the validation variable and
1703 -- the validated object carry different types. This case occurs
1704 -- when the actual is qualified in some fashion.
1707 -- subtype Int is Integer range ...;
1708 -- procedure Call (Val : in out Integer);
1712 -- Call (Integer (Object));
1716 -- Var : Integer := Object; -- conversion to base type
1717 -- if not Var'Valid then -- validity check
1718 -- Call (Var); -- modify Var
1719 -- Object := Int (Var); -- conversion to subtype
1721 if Etype
(Var_Id
) /= Obj_Typ
then
1723 Make_Type_Conversion
(Loc
,
1724 Subtype_Mark
=> New_Occurrence_Of
(Obj_Typ
, Loc
),
1725 Expression
=> Expr
);
1731 -- Object := Object_Type (Var);
1733 Append_To
(Post_Call
,
1734 Make_Assignment_Statement
(Loc
,
1736 Expression
=> Expr
));
1738 -- If the flow reaches this point, then this routine was invoked with
1739 -- an actual which does not denote a validation variable.
1742 pragma Assert
(False);
1745 end Add_Validation_Call_By_Copy_Code
;
1747 ---------------------------
1748 -- Check_Fortran_Logical --
1749 ---------------------------
1751 procedure Check_Fortran_Logical
is
1752 Logical
: constant Entity_Id
:= Etype
(Formal
);
1755 -- Note: this is very incomplete, e.g. it does not handle arrays
1756 -- of logical values. This is really not the right approach at all???)
1759 if Convention
(Subp
) = Convention_Fortran
1760 and then Root_Type
(Etype
(Formal
)) = Standard_Boolean
1761 and then Ekind
(Formal
) /= E_In_Parameter
1763 Var
:= Make_Var
(Actual
);
1764 Append_To
(Post_Call
,
1765 Make_Assignment_Statement
(Loc
,
1766 Name
=> New_Occurrence_Of
(Var
, Loc
),
1768 Unchecked_Convert_To
(
1771 Left_Opnd
=> New_Occurrence_Of
(Var
, Loc
),
1773 Unchecked_Convert_To
(
1775 New_Occurrence_Of
(Standard_False
, Loc
))))));
1777 end Check_Fortran_Logical
;
1783 function Is_Legal_Copy
return Boolean is
1785 -- An attempt to copy a value of such a type can only occur if
1786 -- representation clauses give the actual a misaligned address.
1788 if Is_By_Reference_Type
(Etype
(Formal
)) then
1790 -- The actual may in fact be properly aligned but there is not
1791 -- enough front-end information to determine this. In that case
1792 -- gigi will emit an error if a copy is not legal, or generate
1797 -- For users of Starlet, we assume that the specification of by-
1798 -- reference mechanism is mandatory. This may lead to unaligned
1799 -- objects but at least for DEC legacy code it is known to work.
1800 -- The warning will alert users of this code that a problem may
1803 elsif Mechanism
(Formal
) = By_Reference
1804 and then Is_Valued_Procedure
(Scope
(Formal
))
1807 ("by_reference actual may be misaligned??", Actual
);
1819 function Make_Var
(Actual
: Node_Id
) return Entity_Id
is
1823 if Is_Entity_Name
(Actual
) then
1824 return Entity
(Actual
);
1827 Var
:= Make_Temporary
(Loc
, 'T', Actual
);
1830 Make_Object_Renaming_Declaration
(Loc
,
1831 Defining_Identifier
=> Var
,
1833 New_Occurrence_Of
(Etype
(Actual
), Loc
),
1834 Name
=> Relocate_Node
(Actual
));
1836 Insert_Action
(N
, N_Node
);
1841 -------------------------
1842 -- Reset_Packed_Prefix --
1843 -------------------------
1845 procedure Reset_Packed_Prefix
is
1846 Pfx
: Node_Id
:= Actual
;
1849 Set_Analyzed
(Pfx
, False);
1851 not Nkind_In
(Pfx
, N_Selected_Component
, N_Indexed_Component
);
1852 Pfx
:= Prefix
(Pfx
);
1854 end Reset_Packed_Prefix
;
1856 -- Start of processing for Expand_Actuals
1859 Post_Call
:= New_List
;
1861 Formal
:= First_Formal
(Subp
);
1862 Actual
:= First_Actual
(N
);
1863 while Present
(Formal
) loop
1864 E_Formal
:= Etype
(Formal
);
1865 E_Actual
:= Etype
(Actual
);
1867 -- Handle formals whose type comes from the limited view
1869 if From_Limited_With
(E_Formal
)
1870 and then Has_Non_Limited_View
(E_Formal
)
1872 E_Formal
:= Non_Limited_View
(E_Formal
);
1875 if Is_Scalar_Type
(E_Formal
)
1876 or else Nkind
(Actual
) = N_Slice
1878 Check_Fortran_Logical
;
1882 elsif Ekind
(Formal
) /= E_Out_Parameter
then
1884 -- The unusual case of the current instance of a protected type
1885 -- requires special handling. This can only occur in the context
1886 -- of a call within the body of a protected operation.
1888 if Is_Entity_Name
(Actual
)
1889 and then Ekind
(Entity
(Actual
)) = E_Protected_Type
1890 and then In_Open_Scopes
(Entity
(Actual
))
1892 if Scope
(Subp
) /= Entity
(Actual
) then
1894 ("operation outside protected type may not "
1895 & "call back its protected operations??", Actual
);
1899 Expand_Protected_Object_Reference
(N
, Entity
(Actual
)));
1902 -- Ada 2005 (AI-318-02): If the actual parameter is a call to a
1903 -- build-in-place function, then a temporary return object needs
1904 -- to be created and access to it must be passed to the function.
1905 -- Currently we limit such functions to those with inherently
1906 -- limited result subtypes, but eventually we plan to expand the
1907 -- functions that are treated as build-in-place to include other
1908 -- composite result types.
1910 if Is_Build_In_Place_Function_Call
(Actual
) then
1911 Make_Build_In_Place_Call_In_Anonymous_Context
(Actual
);
1913 -- Ada 2005 (AI-318-02): Specialization of the previous case for
1914 -- actuals containing build-in-place function calls whose returned
1915 -- object covers interface types.
1917 elsif Present
(Unqual_BIP_Iface_Function_Call
(Actual
)) then
1918 Make_Build_In_Place_Iface_Call_In_Anonymous_Context
(Actual
);
1921 Apply_Constraint_Check
(Actual
, E_Formal
);
1923 -- Out parameter case. No constraint checks on access type
1926 elsif Is_Access_Type
(E_Formal
) then
1931 elsif Has_Discriminants
(Base_Type
(E_Formal
))
1932 or else Has_Non_Null_Base_Init_Proc
(E_Formal
)
1934 Apply_Constraint_Check
(Actual
, E_Formal
);
1939 Apply_Constraint_Check
(Actual
, Base_Type
(E_Formal
));
1942 -- Processing for IN-OUT and OUT parameters
1944 if Ekind
(Formal
) /= E_In_Parameter
then
1946 -- For type conversions of arrays, apply length/range checks
1948 if Is_Array_Type
(E_Formal
)
1949 and then Nkind
(Actual
) = N_Type_Conversion
1951 if Is_Constrained
(E_Formal
) then
1952 Apply_Length_Check
(Expression
(Actual
), E_Formal
);
1954 Apply_Range_Check
(Expression
(Actual
), E_Formal
);
1958 -- The actual denotes a variable which captures the value of an
1959 -- object for validation purposes. Add a copy-back to reflect any
1960 -- potential changes in value back into the original object.
1962 -- Var : ... := Object;
1963 -- if not Var'Valid then -- validity check
1964 -- Call (Var); -- modify var
1965 -- Object := Var; -- update Object
1967 -- This case is given higher priority because the subsequent check
1968 -- for type conversion may add an extra copy of the variable and
1969 -- prevent proper value propagation back in the original object.
1971 if Is_Validation_Variable_Reference
(Actual
) then
1972 Add_Validation_Call_By_Copy_Code
(Actual
);
1974 -- If argument is a type conversion for a type that is passed by
1975 -- copy, then we must pass the parameter by copy.
1977 elsif Nkind
(Actual
) = N_Type_Conversion
1979 (Is_Numeric_Type
(E_Formal
)
1980 or else Is_Access_Type
(E_Formal
)
1981 or else Is_Enumeration_Type
(E_Formal
)
1982 or else Is_Bit_Packed_Array
(Etype
(Formal
))
1983 or else Is_Bit_Packed_Array
(Etype
(Expression
(Actual
)))
1985 -- Also pass by copy if change of representation
1987 or else not Same_Representation
1989 Etype
(Expression
(Actual
))))
1991 Add_Call_By_Copy_Code
;
1993 -- References to components of bit-packed arrays are expanded
1994 -- at this point, rather than at the point of analysis of the
1995 -- actuals, to handle the expansion of the assignment to
1996 -- [in] out parameters.
1998 elsif Is_Ref_To_Bit_Packed_Array
(Actual
) then
1999 Add_Simple_Call_By_Copy_Code
;
2001 -- If a non-scalar actual is possibly bit-aligned, we need a copy
2002 -- because the back-end cannot cope with such objects. In other
2003 -- cases where alignment forces a copy, the back-end generates
2004 -- it properly. It should not be generated unconditionally in the
2005 -- front-end because it does not know precisely the alignment
2006 -- requirements of the target, and makes too conservative an
2007 -- estimate, leading to superfluous copies or spurious errors
2008 -- on by-reference parameters.
2010 elsif Nkind
(Actual
) = N_Selected_Component
2012 Component_May_Be_Bit_Aligned
(Entity
(Selector_Name
(Actual
)))
2013 and then not Represented_As_Scalar
(Etype
(Formal
))
2015 Add_Simple_Call_By_Copy_Code
;
2017 -- References to slices of bit-packed arrays are expanded
2019 elsif Is_Ref_To_Bit_Packed_Slice
(Actual
) then
2020 Add_Call_By_Copy_Code
;
2022 -- References to possibly unaligned slices of arrays are expanded
2024 elsif Is_Possibly_Unaligned_Slice
(Actual
) then
2025 Add_Call_By_Copy_Code
;
2027 -- Deal with access types where the actual subtype and the
2028 -- formal subtype are not the same, requiring a check.
2030 -- It is necessary to exclude tagged types because of "downward
2031 -- conversion" errors.
2033 elsif Is_Access_Type
(E_Formal
)
2034 and then not Same_Type
(E_Formal
, E_Actual
)
2035 and then not Is_Tagged_Type
(Designated_Type
(E_Formal
))
2037 Add_Call_By_Copy_Code
;
2039 -- If the actual is not a scalar and is marked for volatile
2040 -- treatment, whereas the formal is not volatile, then pass
2041 -- by copy unless it is a by-reference type.
2043 -- Note: we use Is_Volatile here rather than Treat_As_Volatile,
2044 -- because this is the enforcement of a language rule that applies
2045 -- only to "real" volatile variables, not e.g. to the address
2046 -- clause overlay case.
2048 elsif Is_Entity_Name
(Actual
)
2049 and then Is_Volatile
(Entity
(Actual
))
2050 and then not Is_By_Reference_Type
(E_Actual
)
2051 and then not Is_Scalar_Type
(Etype
(Entity
(Actual
)))
2052 and then not Is_Volatile
(E_Formal
)
2054 Add_Call_By_Copy_Code
;
2056 elsif Nkind
(Actual
) = N_Indexed_Component
2057 and then Is_Entity_Name
(Prefix
(Actual
))
2058 and then Has_Volatile_Components
(Entity
(Prefix
(Actual
)))
2060 Add_Call_By_Copy_Code
;
2062 -- Add call-by-copy code for the case of scalar out parameters
2063 -- when it is not known at compile time that the subtype of the
2064 -- formal is a subrange of the subtype of the actual (or vice
2065 -- versa for in out parameters), in order to get range checks
2066 -- on such actuals. (Maybe this case should be handled earlier
2067 -- in the if statement???)
2069 elsif Is_Scalar_Type
(E_Formal
)
2071 (not In_Subrange_Of
(E_Formal
, E_Actual
)
2073 (Ekind
(Formal
) = E_In_Out_Parameter
2074 and then not In_Subrange_Of
(E_Actual
, E_Formal
)))
2076 -- Perhaps the setting back to False should be done within
2077 -- Add_Call_By_Copy_Code, since it could get set on other
2078 -- cases occurring above???
2080 if Do_Range_Check
(Actual
) then
2081 Set_Do_Range_Check
(Actual
, False);
2084 Add_Call_By_Copy_Code
;
2087 -- RM 3.2.4 (23/3): A predicate is checked on in-out and out
2088 -- by-reference parameters on exit from the call. If the actual
2089 -- is a derived type and the operation is inherited, the body
2090 -- of the operation will not contain a call to the predicate
2091 -- function, so it must be done explicitly after the call. Ditto
2092 -- if the actual is an entity of a predicated subtype.
2094 -- The rule refers to by-reference types, but a check is needed
2095 -- for by-copy types as well. That check is subsumed by the rule
2096 -- for subtype conversion on assignment, but we can generate the
2097 -- required check now.
2099 -- Note also that Subp may be either a subprogram entity for
2100 -- direct calls, or a type entity for indirect calls, which must
2101 -- be handled separately because the name does not denote an
2102 -- overloadable entity.
2104 By_Ref_Predicate_Check
: declare
2105 Aund
: constant Entity_Id
:= Underlying_Type
(E_Actual
);
2108 function Is_Public_Subp
return Boolean;
2109 -- Check whether the subprogram being called is a visible
2110 -- operation of the type of the actual. Used to determine
2111 -- whether an invariant check must be generated on the
2114 ---------------------
2115 -- Is_Public_Subp --
2116 ---------------------
2118 function Is_Public_Subp
return Boolean is
2119 Pack
: constant Entity_Id
:= Scope
(Subp
);
2120 Subp_Decl
: Node_Id
;
2123 if not Is_Subprogram
(Subp
) then
2126 -- The operation may be inherited, or a primitive of the
2130 Nkind_In
(Parent
(Subp
), N_Private_Extension_Declaration
,
2131 N_Full_Type_Declaration
)
2133 Subp_Decl
:= Parent
(Subp
);
2136 Subp_Decl
:= Unit_Declaration_Node
(Subp
);
2139 return Ekind
(Pack
) = E_Package
2141 List_Containing
(Subp_Decl
) =
2142 Visible_Declarations
2143 (Specification
(Unit_Declaration_Node
(Pack
)));
2146 -- Start of processing for By_Ref_Predicate_Check
2155 if Has_Predicates
(Atyp
)
2156 and then Present
(Predicate_Function
(Atyp
))
2158 -- Skip predicate checks for special cases
2160 and then Predicate_Tests_On_Arguments
(Subp
)
2162 Append_To
(Post_Call
,
2163 Make_Predicate_Check
(Atyp
, Actual
));
2166 -- We generated caller-side invariant checks in two cases:
2168 -- a) when calling an inherited operation, where there is an
2169 -- implicit view conversion of the actual to the parent type.
2171 -- b) When the conversion is explicit
2173 -- We treat these cases separately because the required
2174 -- conversion for a) is added later when expanding the call.
2176 if Has_Invariants
(Etype
(Actual
))
2178 Nkind
(Parent
(Subp
)) = N_Private_Extension_Declaration
2180 if Comes_From_Source
(N
) and then Is_Public_Subp
then
2181 Append_To
(Post_Call
, Make_Invariant_Call
(Actual
));
2184 elsif Nkind
(Actual
) = N_Type_Conversion
2185 and then Has_Invariants
(Etype
(Expression
(Actual
)))
2187 if Comes_From_Source
(N
) and then Is_Public_Subp
then
2188 Append_To
(Post_Call
,
2189 Make_Invariant_Call
(Expression
(Actual
)));
2192 end By_Ref_Predicate_Check
;
2194 -- Processing for IN parameters
2197 -- For IN parameters in the bit-packed array case, we expand an
2198 -- indexed component (the circuit in Exp_Ch4 deliberately left
2199 -- indexed components appearing as actuals untouched, so that
2200 -- the special processing above for the OUT and IN OUT cases
2201 -- could be performed. We could make the test in Exp_Ch4 more
2202 -- complex and have it detect the parameter mode, but it is
2203 -- easier simply to handle all cases here.)
2205 if Nkind
(Actual
) = N_Indexed_Component
2206 and then Is_Bit_Packed_Array
(Etype
(Prefix
(Actual
)))
2208 Reset_Packed_Prefix
;
2209 Expand_Packed_Element_Reference
(Actual
);
2211 -- If we have a reference to a bit-packed array, we copy it, since
2212 -- the actual must be byte aligned.
2214 -- Is this really necessary in all cases???
2216 elsif Is_Ref_To_Bit_Packed_Array
(Actual
) then
2217 Add_Simple_Call_By_Copy_Code
;
2219 -- If a non-scalar actual is possibly unaligned, we need a copy
2221 elsif Is_Possibly_Unaligned_Object
(Actual
)
2222 and then not Represented_As_Scalar
(Etype
(Formal
))
2224 Add_Simple_Call_By_Copy_Code
;
2226 -- Similarly, we have to expand slices of packed arrays here
2227 -- because the result must be byte aligned.
2229 elsif Is_Ref_To_Bit_Packed_Slice
(Actual
) then
2230 Add_Call_By_Copy_Code
;
2232 -- Only processing remaining is to pass by copy if this is a
2233 -- reference to a possibly unaligned slice, since the caller
2234 -- expects an appropriately aligned argument.
2236 elsif Is_Possibly_Unaligned_Slice
(Actual
) then
2237 Add_Call_By_Copy_Code
;
2239 -- An unusual case: a current instance of an enclosing task can be
2240 -- an actual, and must be replaced by a reference to self.
2242 elsif Is_Entity_Name
(Actual
)
2243 and then Is_Task_Type
(Entity
(Actual
))
2245 if In_Open_Scopes
(Entity
(Actual
)) then
2247 (Make_Function_Call
(Loc
,
2248 Name
=> New_Occurrence_Of
(RTE
(RE_Self
), Loc
))));
2251 -- A task type cannot otherwise appear as an actual
2254 raise Program_Error
;
2259 Next_Formal
(Formal
);
2260 Next_Actual
(Actual
);
2268 procedure Expand_Call
(N
: Node_Id
) is
2269 Post_Call
: List_Id
;
2272 pragma Assert
(Nkind_In
(N
, N_Entry_Call_Statement
,
2274 N_Procedure_Call_Statement
));
2276 Expand_Call_Helper
(N
, Post_Call
);
2277 Insert_Post_Call_Actions
(N
, Post_Call
);
2280 ------------------------
2281 -- Expand_Call_Helper --
2282 ------------------------
2284 -- This procedure handles expansion of function calls and procedure call
2285 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
2286 -- Expand_N_Procedure_Call_Statement). Processing for calls includes:
2288 -- Replace call to Raise_Exception by Raise_Exception_Always if possible
2289 -- Provide values of actuals for all formals in Extra_Formals list
2290 -- Replace "call" to enumeration literal function by literal itself
2291 -- Rewrite call to predefined operator as operator
2292 -- Replace actuals to in-out parameters that are numeric conversions,
2293 -- with explicit assignment to temporaries before and after the call.
2295 -- Note that the list of actuals has been filled with default expressions
2296 -- during semantic analysis of the call. Only the extra actuals required
2297 -- for the 'Constrained attribute and for accessibility checks are added
2300 procedure Expand_Call_Helper
(N
: Node_Id
; Post_Call
: out List_Id
) is
2301 Loc
: constant Source_Ptr
:= Sloc
(N
);
2302 Call_Node
: Node_Id
:= N
;
2303 Extra_Actuals
: List_Id
:= No_List
;
2304 Prev
: Node_Id
:= Empty
;
2306 procedure Add_Actual_Parameter
(Insert_Param
: Node_Id
);
2307 -- Adds one entry to the end of the actual parameter list. Used for
2308 -- default parameters and for extra actuals (for Extra_Formals). The
2309 -- argument is an N_Parameter_Association node.
2311 procedure Add_Extra_Actual
(Expr
: Node_Id
; EF
: Entity_Id
);
2312 -- Adds an extra actual to the list of extra actuals. Expr is the
2313 -- expression for the value of the actual, EF is the entity for the
2316 procedure Add_View_Conversion_Invariants
2317 (Formal
: Entity_Id
;
2319 -- Adds invariant checks for every intermediate type between the range
2320 -- of a view converted argument to its ancestor (from parent to child).
2322 function Inherited_From_Formal
(S
: Entity_Id
) return Entity_Id
;
2323 -- Within an instance, a type derived from an untagged formal derived
2324 -- type inherits from the original parent, not from the actual. The
2325 -- current derivation mechanism has the derived type inherit from the
2326 -- actual, which is only correct outside of the instance. If the
2327 -- subprogram is inherited, we test for this particular case through a
2328 -- convoluted tree traversal before setting the proper subprogram to be
2331 function In_Unfrozen_Instance
(E
: Entity_Id
) return Boolean;
2332 -- Return true if E comes from an instance that is not yet frozen
2334 function Is_Direct_Deep_Call
(Subp
: Entity_Id
) return Boolean;
2335 -- Determine if Subp denotes a non-dispatching call to a Deep routine
2337 function New_Value
(From
: Node_Id
) return Node_Id
;
2338 -- From is the original Expression. New_Value is equivalent to a call
2339 -- to Duplicate_Subexpr with an explicit dereference when From is an
2340 -- access parameter.
2342 --------------------------
2343 -- Add_Actual_Parameter --
2344 --------------------------
2346 procedure Add_Actual_Parameter
(Insert_Param
: Node_Id
) is
2347 Actual_Expr
: constant Node_Id
:=
2348 Explicit_Actual_Parameter
(Insert_Param
);
2351 -- Case of insertion is first named actual
2353 if No
(Prev
) or else
2354 Nkind
(Parent
(Prev
)) /= N_Parameter_Association
2356 Set_Next_Named_Actual
2357 (Insert_Param
, First_Named_Actual
(Call_Node
));
2358 Set_First_Named_Actual
(Call_Node
, Actual_Expr
);
2361 if No
(Parameter_Associations
(Call_Node
)) then
2362 Set_Parameter_Associations
(Call_Node
, New_List
);
2365 Append
(Insert_Param
, Parameter_Associations
(Call_Node
));
2368 Insert_After
(Prev
, Insert_Param
);
2371 -- Case of insertion is not first named actual
2374 Set_Next_Named_Actual
2375 (Insert_Param
, Next_Named_Actual
(Parent
(Prev
)));
2376 Set_Next_Named_Actual
(Parent
(Prev
), Actual_Expr
);
2377 Append
(Insert_Param
, Parameter_Associations
(Call_Node
));
2380 Prev
:= Actual_Expr
;
2381 end Add_Actual_Parameter
;
2383 ----------------------
2384 -- Add_Extra_Actual --
2385 ----------------------
2387 procedure Add_Extra_Actual
(Expr
: Node_Id
; EF
: Entity_Id
) is
2388 Loc
: constant Source_Ptr
:= Sloc
(Expr
);
2391 if Extra_Actuals
= No_List
then
2392 Extra_Actuals
:= New_List
;
2393 Set_Parent
(Extra_Actuals
, Call_Node
);
2396 Append_To
(Extra_Actuals
,
2397 Make_Parameter_Association
(Loc
,
2398 Selector_Name
=> New_Occurrence_Of
(EF
, Loc
),
2399 Explicit_Actual_Parameter
=> Expr
));
2401 Analyze_And_Resolve
(Expr
, Etype
(EF
));
2403 if Nkind
(Call_Node
) = N_Function_Call
then
2404 Set_Is_Accessibility_Actual
(Parent
(Expr
));
2406 end Add_Extra_Actual
;
2408 ------------------------------------
2409 -- Add_View_Conversion_Invariants --
2410 ------------------------------------
2412 procedure Add_View_Conversion_Invariants
2413 (Formal
: Entity_Id
;
2417 Curr_Typ
: Entity_Id
;
2418 Inv_Checks
: List_Id
;
2419 Par_Typ
: Entity_Id
;
2422 Inv_Checks
:= No_List
;
2424 -- Extract the argument from a potentially nested set of view
2428 while Nkind
(Arg
) = N_Type_Conversion
loop
2429 Arg
:= Expression
(Arg
);
2432 -- Move up the derivation chain starting with the type of the formal
2433 -- parameter down to the type of the actual object.
2436 Par_Typ
:= Etype
(Arg
);
2437 while Par_Typ
/= Etype
(Formal
) and Par_Typ
/= Curr_Typ
loop
2438 Curr_Typ
:= Par_Typ
;
2440 if Has_Invariants
(Curr_Typ
)
2441 and then Present
(Invariant_Procedure
(Curr_Typ
))
2443 -- Verify the invariate of the current type. Generate:
2445 -- <Curr_Typ>Invariant (Curr_Typ (Arg));
2447 Prepend_New_To
(Inv_Checks
,
2448 Make_Procedure_Call_Statement
(Loc
,
2451 (Invariant_Procedure
(Curr_Typ
), Loc
),
2452 Parameter_Associations
=> New_List
(
2453 Make_Type_Conversion
(Loc
,
2454 Subtype_Mark
=> New_Occurrence_Of
(Curr_Typ
, Loc
),
2455 Expression
=> New_Copy_Tree
(Arg
)))));
2458 Par_Typ
:= Base_Type
(Etype
(Curr_Typ
));
2461 if not Is_Empty_List
(Inv_Checks
) then
2462 Insert_Actions_After
(N
, Inv_Checks
);
2464 end Add_View_Conversion_Invariants
;
2466 ---------------------------
2467 -- Inherited_From_Formal --
2468 ---------------------------
2470 function Inherited_From_Formal
(S
: Entity_Id
) return Entity_Id
is
2472 Gen_Par
: Entity_Id
;
2473 Gen_Prim
: Elist_Id
;
2478 -- If the operation is inherited, it is attached to the corresponding
2479 -- type derivation. If the parent in the derivation is a generic
2480 -- actual, it is a subtype of the actual, and we have to recover the
2481 -- original derived type declaration to find the proper parent.
2483 if Nkind
(Parent
(S
)) /= N_Full_Type_Declaration
2484 or else not Is_Derived_Type
(Defining_Identifier
(Parent
(S
)))
2485 or else Nkind
(Type_Definition
(Original_Node
(Parent
(S
)))) /=
2486 N_Derived_Type_Definition
2487 or else not In_Instance
2494 (Type_Definition
(Original_Node
(Parent
(S
))));
2496 if Nkind
(Indic
) = N_Subtype_Indication
then
2497 Par
:= Entity
(Subtype_Mark
(Indic
));
2499 Par
:= Entity
(Indic
);
2503 if not Is_Generic_Actual_Type
(Par
)
2504 or else Is_Tagged_Type
(Par
)
2505 or else Nkind
(Parent
(Par
)) /= N_Subtype_Declaration
2506 or else not In_Open_Scopes
(Scope
(Par
))
2510 Gen_Par
:= Generic_Parent_Type
(Parent
(Par
));
2513 -- If the actual has no generic parent type, the formal is not
2514 -- a formal derived type, so nothing to inherit.
2516 if No
(Gen_Par
) then
2520 -- If the generic parent type is still the generic type, this is a
2521 -- private formal, not a derived formal, and there are no operations
2522 -- inherited from the formal.
2524 if Nkind
(Parent
(Gen_Par
)) = N_Formal_Type_Declaration
then
2528 Gen_Prim
:= Collect_Primitive_Operations
(Gen_Par
);
2530 Elmt
:= First_Elmt
(Gen_Prim
);
2531 while Present
(Elmt
) loop
2532 if Chars
(Node
(Elmt
)) = Chars
(S
) then
2538 F1
:= First_Formal
(S
);
2539 F2
:= First_Formal
(Node
(Elmt
));
2541 and then Present
(F2
)
2543 if Etype
(F1
) = Etype
(F2
)
2544 or else Etype
(F2
) = Gen_Par
2550 exit; -- not the right subprogram
2562 raise Program_Error
;
2563 end Inherited_From_Formal
;
2565 --------------------------
2566 -- In_Unfrozen_Instance --
2567 --------------------------
2569 function In_Unfrozen_Instance
(E
: Entity_Id
) return Boolean is
2574 while Present
(S
) and then S
/= Standard_Standard
loop
2575 if Is_Generic_Instance
(S
)
2576 and then Present
(Freeze_Node
(S
))
2577 and then not Analyzed
(Freeze_Node
(S
))
2586 end In_Unfrozen_Instance
;
2588 -------------------------
2589 -- Is_Direct_Deep_Call --
2590 -------------------------
2592 function Is_Direct_Deep_Call
(Subp
: Entity_Id
) return Boolean is
2594 if Is_TSS
(Subp
, TSS_Deep_Adjust
)
2595 or else Is_TSS
(Subp
, TSS_Deep_Finalize
)
2596 or else Is_TSS
(Subp
, TSS_Deep_Initialize
)
2603 Actual
:= First
(Parameter_Associations
(N
));
2604 Formal
:= First_Formal
(Subp
);
2605 while Present
(Actual
)
2606 and then Present
(Formal
)
2608 if Nkind
(Actual
) = N_Identifier
2609 and then Is_Controlling_Actual
(Actual
)
2610 and then Etype
(Actual
) = Etype
(Formal
)
2616 Next_Formal
(Formal
);
2622 end Is_Direct_Deep_Call
;
2628 function New_Value
(From
: Node_Id
) return Node_Id
is
2629 Res
: constant Node_Id
:= Duplicate_Subexpr
(From
);
2631 if Is_Access_Type
(Etype
(From
)) then
2632 return Make_Explicit_Dereference
(Sloc
(From
), Prefix
=> Res
);
2640 Remote
: constant Boolean := Is_Remote_Call
(Call_Node
);
2643 Orig_Subp
: Entity_Id
:= Empty
;
2644 Param_Count
: Natural := 0;
2645 Parent_Formal
: Entity_Id
;
2646 Parent_Subp
: Entity_Id
;
2647 Pref_Entity
: Entity_Id
;
2651 Prev_Orig
: Node_Id
;
2652 -- Original node for an actual, which may have been rewritten. If the
2653 -- actual is a function call that has been transformed from a selected
2654 -- component, the original node is unanalyzed. Otherwise, it carries
2655 -- semantic information used to generate additional actuals.
2657 CW_Interface_Formals_Present
: Boolean := False;
2659 -- Start of processing for Expand_Call_Helper
2662 Post_Call
:= New_List
;
2664 -- Expand the function or procedure call if the first actual has a
2665 -- declared dimension aspect, and the subprogram is declared in one
2666 -- of the dimension I/O packages.
2668 if Ada_Version
>= Ada_2012
2670 Nkind_In
(Call_Node
, N_Procedure_Call_Statement
, N_Function_Call
)
2671 and then Present
(Parameter_Associations
(Call_Node
))
2673 Expand_Put_Call_With_Symbol
(Call_Node
);
2676 -- Ignore if previous error
2678 if Nkind
(Call_Node
) in N_Has_Etype
2679 and then Etype
(Call_Node
) = Any_Type
2684 -- Call using access to subprogram with explicit dereference
2686 if Nkind
(Name
(Call_Node
)) = N_Explicit_Dereference
then
2687 Subp
:= Etype
(Name
(Call_Node
));
2688 Parent_Subp
:= Empty
;
2690 -- Case of call to simple entry, where the Name is a selected component
2691 -- whose prefix is the task, and whose selector name is the entry name
2693 elsif Nkind
(Name
(Call_Node
)) = N_Selected_Component
then
2694 Subp
:= Entity
(Selector_Name
(Name
(Call_Node
)));
2695 Parent_Subp
:= Empty
;
2697 -- Case of call to member of entry family, where Name is an indexed
2698 -- component, with the prefix being a selected component giving the
2699 -- task and entry family name, and the index being the entry index.
2701 elsif Nkind
(Name
(Call_Node
)) = N_Indexed_Component
then
2702 Subp
:= Entity
(Selector_Name
(Prefix
(Name
(Call_Node
))));
2703 Parent_Subp
:= Empty
;
2708 Subp
:= Entity
(Name
(Call_Node
));
2709 Parent_Subp
:= Alias
(Subp
);
2711 -- Replace call to Raise_Exception by call to Raise_Exception_Always
2712 -- if we can tell that the first parameter cannot possibly be null.
2713 -- This improves efficiency by avoiding a run-time test.
2715 -- We do not do this if Raise_Exception_Always does not exist, which
2716 -- can happen in configurable run time profiles which provide only a
2719 if Is_RTE
(Subp
, RE_Raise_Exception
)
2720 and then RTE_Available
(RE_Raise_Exception_Always
)
2723 FA
: constant Node_Id
:=
2724 Original_Node
(First_Actual
(Call_Node
));
2727 -- The case we catch is where the first argument is obtained
2728 -- using the Identity attribute (which must always be
2731 if Nkind
(FA
) = N_Attribute_Reference
2732 and then Attribute_Name
(FA
) = Name_Identity
2734 Subp
:= RTE
(RE_Raise_Exception_Always
);
2735 Set_Name
(Call_Node
, New_Occurrence_Of
(Subp
, Loc
));
2740 if Ekind
(Subp
) = E_Entry
then
2741 Parent_Subp
:= Empty
;
2745 -- Ada 2005 (AI-345): We have a procedure call as a triggering
2746 -- alternative in an asynchronous select or as an entry call in
2747 -- a conditional or timed select. Check whether the procedure call
2748 -- is a renaming of an entry and rewrite it as an entry call.
2750 if Ada_Version
>= Ada_2005
2751 and then Nkind
(Call_Node
) = N_Procedure_Call_Statement
2753 ((Nkind
(Parent
(Call_Node
)) = N_Triggering_Alternative
2754 and then Triggering_Statement
(Parent
(Call_Node
)) = Call_Node
)
2756 (Nkind
(Parent
(Call_Node
)) = N_Entry_Call_Alternative
2757 and then Entry_Call_Statement
(Parent
(Call_Node
)) = Call_Node
))
2761 Ren_Root
: Entity_Id
:= Subp
;
2764 -- This may be a chain of renamings, find the root
2766 if Present
(Alias
(Ren_Root
)) then
2767 Ren_Root
:= Alias
(Ren_Root
);
2770 if Present
(Original_Node
(Parent
(Parent
(Ren_Root
)))) then
2771 Ren_Decl
:= Original_Node
(Parent
(Parent
(Ren_Root
)));
2773 if Nkind
(Ren_Decl
) = N_Subprogram_Renaming_Declaration
then
2775 Make_Entry_Call_Statement
(Loc
,
2777 New_Copy_Tree
(Name
(Ren_Decl
)),
2778 Parameter_Associations
=>
2780 (Parameter_Associations
(Call_Node
))));
2788 if Modify_Tree_For_C
2789 and then Nkind
(Call_Node
) = N_Function_Call
2790 and then Is_Entity_Name
(Name
(Call_Node
))
2793 Func_Id
: constant Entity_Id
:=
2794 Ultimate_Alias
(Entity
(Name
(Call_Node
)));
2796 -- When generating C code, transform a function call that returns
2797 -- a constrained array type into procedure form.
2799 if Rewritten_For_C
(Func_Id
) then
2801 -- For internally generated calls ensure that they reference
2802 -- the entity of the spec of the called function (needed since
2803 -- the expander may generate calls using the entity of their
2804 -- body). See for example Expand_Boolean_Operator().
2806 if not (Comes_From_Source
(Call_Node
))
2807 and then Nkind
(Unit_Declaration_Node
(Func_Id
)) =
2810 Set_Entity
(Name
(Call_Node
),
2811 Corresponding_Function
2812 (Corresponding_Procedure
(Func_Id
)));
2815 Rewrite_Function_Call_For_C
(Call_Node
);
2818 -- Also introduce a temporary for functions that return a record
2819 -- called within another procedure or function call, since records
2820 -- are passed by pointer in the generated C code, and we cannot
2821 -- take a pointer from a subprogram call.
2823 elsif Nkind
(Parent
(Call_Node
)) in N_Subprogram_Call
2824 and then Is_Record_Type
(Etype
(Func_Id
))
2827 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
2832 -- Temp : ... := Func_Call (...);
2835 Make_Object_Declaration
(Loc
,
2836 Defining_Identifier
=> Temp_Id
,
2837 Object_Definition
=>
2838 New_Occurrence_Of
(Etype
(Func_Id
), Loc
),
2840 Make_Function_Call
(Loc
,
2842 New_Occurrence_Of
(Func_Id
, Loc
),
2843 Parameter_Associations
=>
2844 Parameter_Associations
(Call_Node
)));
2846 Insert_Action
(Parent
(Call_Node
), Decl
);
2847 Rewrite
(Call_Node
, New_Occurrence_Of
(Temp_Id
, Loc
));
2854 -- First step, compute extra actuals, corresponding to any Extra_Formals
2855 -- present. Note that we do not access Extra_Formals directly, instead
2856 -- we simply note the presence of the extra formals as we process the
2857 -- regular formals collecting corresponding actuals in Extra_Actuals.
2859 -- We also generate any required range checks for actuals for in formals
2860 -- as we go through the loop, since this is a convenient place to do it.
2861 -- (Though it seems that this would be better done in Expand_Actuals???)
2863 -- Special case: Thunks must not compute the extra actuals; they must
2864 -- just propagate to the target primitive their extra actuals.
2866 if Is_Thunk
(Current_Scope
)
2867 and then Thunk_Entity
(Current_Scope
) = Subp
2868 and then Present
(Extra_Formals
(Subp
))
2870 pragma Assert
(Present
(Extra_Formals
(Current_Scope
)));
2873 Target_Formal
: Entity_Id
;
2874 Thunk_Formal
: Entity_Id
;
2877 Target_Formal
:= Extra_Formals
(Subp
);
2878 Thunk_Formal
:= Extra_Formals
(Current_Scope
);
2879 while Present
(Target_Formal
) loop
2881 (Expr
=> New_Occurrence_Of
(Thunk_Formal
, Loc
),
2882 EF
=> Thunk_Formal
);
2884 Target_Formal
:= Extra_Formal
(Target_Formal
);
2885 Thunk_Formal
:= Extra_Formal
(Thunk_Formal
);
2888 while Is_Non_Empty_List
(Extra_Actuals
) loop
2889 Add_Actual_Parameter
(Remove_Head
(Extra_Actuals
));
2892 Expand_Actuals
(Call_Node
, Subp
, Post_Call
);
2893 pragma Assert
(Is_Empty_List
(Post_Call
));
2898 Formal
:= First_Formal
(Subp
);
2899 Actual
:= First_Actual
(Call_Node
);
2901 while Present
(Formal
) loop
2903 -- Generate range check if required
2905 if Do_Range_Check
(Actual
)
2906 and then Ekind
(Formal
) = E_In_Parameter
2908 Generate_Range_Check
2909 (Actual
, Etype
(Formal
), CE_Range_Check_Failed
);
2912 -- Prepare to examine current entry
2915 Prev_Orig
:= Original_Node
(Prev
);
2917 -- Ada 2005 (AI-251): Check if any formal is a class-wide interface
2918 -- to expand it in a further round.
2920 CW_Interface_Formals_Present
:=
2921 CW_Interface_Formals_Present
2923 (Is_Class_Wide_Type
(Etype
(Formal
))
2924 and then Is_Interface
(Etype
(Etype
(Formal
))))
2926 (Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
2927 and then Is_Class_Wide_Type
(Directly_Designated_Type
2928 (Etype
(Etype
(Formal
))))
2929 and then Is_Interface
(Directly_Designated_Type
2930 (Etype
(Etype
(Formal
)))));
2932 -- Create possible extra actual for constrained case. Usually, the
2933 -- extra actual is of the form actual'constrained, but since this
2934 -- attribute is only available for unconstrained records, TRUE is
2935 -- expanded if the type of the formal happens to be constrained (for
2936 -- instance when this procedure is inherited from an unconstrained
2937 -- record to a constrained one) or if the actual has no discriminant
2938 -- (its type is constrained). An exception to this is the case of a
2939 -- private type without discriminants. In this case we pass FALSE
2940 -- because the object has underlying discriminants with defaults.
2942 if Present
(Extra_Constrained
(Formal
)) then
2943 if Ekind
(Etype
(Prev
)) in Private_Kind
2944 and then not Has_Discriminants
(Base_Type
(Etype
(Prev
)))
2947 (Expr
=> New_Occurrence_Of
(Standard_False
, Loc
),
2948 EF
=> Extra_Constrained
(Formal
));
2950 elsif Is_Constrained
(Etype
(Formal
))
2951 or else not Has_Discriminants
(Etype
(Prev
))
2954 (Expr
=> New_Occurrence_Of
(Standard_True
, Loc
),
2955 EF
=> Extra_Constrained
(Formal
));
2957 -- Do not produce extra actuals for Unchecked_Union parameters.
2958 -- Jump directly to the end of the loop.
2960 elsif Is_Unchecked_Union
(Base_Type
(Etype
(Actual
))) then
2961 goto Skip_Extra_Actual_Generation
;
2964 -- If the actual is a type conversion, then the constrained
2965 -- test applies to the actual, not the target type.
2971 -- Test for unchecked conversions as well, which can occur
2972 -- as out parameter actuals on calls to stream procedures.
2975 while Nkind_In
(Act_Prev
, N_Type_Conversion
,
2976 N_Unchecked_Type_Conversion
)
2978 Act_Prev
:= Expression
(Act_Prev
);
2981 -- If the expression is a conversion of a dereference, this
2982 -- is internally generated code that manipulates addresses,
2983 -- e.g. when building interface tables. No check should
2984 -- occur in this case, and the discriminated object is not
2987 if not Comes_From_Source
(Actual
)
2988 and then Nkind
(Actual
) = N_Unchecked_Type_Conversion
2989 and then Nkind
(Act_Prev
) = N_Explicit_Dereference
2992 (Expr
=> New_Occurrence_Of
(Standard_False
, Loc
),
2993 EF
=> Extra_Constrained
(Formal
));
2998 Make_Attribute_Reference
(Sloc
(Prev
),
3000 Duplicate_Subexpr_No_Checks
3001 (Act_Prev
, Name_Req
=> True),
3002 Attribute_Name
=> Name_Constrained
),
3003 EF
=> Extra_Constrained
(Formal
));
3009 -- Create possible extra actual for accessibility level
3011 if Present
(Extra_Accessibility
(Formal
)) then
3013 -- Ada 2005 (AI-252): If the actual was rewritten as an Access
3014 -- attribute, then the original actual may be an aliased object
3015 -- occurring as the prefix in a call using "Object.Operation"
3016 -- notation. In that case we must pass the level of the object,
3017 -- so Prev_Orig is reset to Prev and the attribute will be
3018 -- processed by the code for Access attributes further below.
3020 if Prev_Orig
/= Prev
3021 and then Nkind
(Prev
) = N_Attribute_Reference
3022 and then Get_Attribute_Id
(Attribute_Name
(Prev
)) =
3024 and then Is_Aliased_View
(Prev_Orig
)
3028 -- A class-wide precondition generates a test in which formals of
3029 -- the subprogram are replaced by actuals that came from source.
3030 -- In that case as well, the accessiblity comes from the actual.
3031 -- This is the one case in which there are references to formals
3032 -- outside of their subprogram.
3034 elsif Prev_Orig
/= Prev
3035 and then Is_Entity_Name
(Prev_Orig
)
3036 and then Present
(Entity
(Prev_Orig
))
3037 and then Is_Formal
(Entity
(Prev_Orig
))
3038 and then not In_Open_Scopes
(Scope
(Entity
(Prev_Orig
)))
3042 -- If the actual is a formal of an enclosing subprogram it is
3043 -- the right entity, even if it is a rewriting. This happens
3044 -- when the call is within an inherited condition or predicate.
3046 elsif Is_Entity_Name
(Actual
)
3047 and then Is_Formal
(Entity
(Actual
))
3048 and then In_Open_Scopes
(Scope
(Entity
(Actual
)))
3052 elsif Nkind
(Prev_Orig
) = N_Type_Conversion
then
3053 Prev_Orig
:= Expression
(Prev_Orig
);
3056 -- Ada 2005 (AI-251): Thunks must propagate the extra actuals of
3057 -- accessibility levels.
3059 if Is_Thunk
(Current_Scope
) then
3061 Parm_Ent
: Entity_Id
;
3064 if Is_Controlling_Actual
(Actual
) then
3066 -- Find the corresponding actual of the thunk
3068 Parm_Ent
:= First_Entity
(Current_Scope
);
3069 for J
in 2 .. Param_Count
loop
3070 Next_Entity
(Parm_Ent
);
3073 -- Handle unchecked conversion of access types generated
3074 -- in thunks (cf. Expand_Interface_Thunk).
3076 elsif Is_Access_Type
(Etype
(Actual
))
3077 and then Nkind
(Actual
) = N_Unchecked_Type_Conversion
3079 Parm_Ent
:= Entity
(Expression
(Actual
));
3081 else pragma Assert
(Is_Entity_Name
(Actual
));
3082 Parm_Ent
:= Entity
(Actual
);
3087 New_Occurrence_Of
(Extra_Accessibility
(Parm_Ent
), Loc
),
3088 EF
=> Extra_Accessibility
(Formal
));
3091 elsif Is_Entity_Name
(Prev_Orig
) then
3093 -- When passing an access parameter, or a renaming of an access
3094 -- parameter, as the actual to another access parameter we need
3095 -- to pass along the actual's own access level parameter. This
3096 -- is done if we are within the scope of the formal access
3097 -- parameter (if this is an inlined body the extra formal is
3100 if (Is_Formal
(Entity
(Prev_Orig
))
3102 (Present
(Renamed_Object
(Entity
(Prev_Orig
)))
3104 Is_Entity_Name
(Renamed_Object
(Entity
(Prev_Orig
)))
3107 (Entity
(Renamed_Object
(Entity
(Prev_Orig
))))))
3108 and then Ekind
(Etype
(Prev_Orig
)) = E_Anonymous_Access_Type
3109 and then In_Open_Scopes
(Scope
(Entity
(Prev_Orig
)))
3112 Parm_Ent
: constant Entity_Id
:= Param_Entity
(Prev_Orig
);
3115 pragma Assert
(Present
(Parm_Ent
));
3117 if Present
(Extra_Accessibility
(Parm_Ent
)) then
3121 (Extra_Accessibility
(Parm_Ent
), Loc
),
3122 EF
=> Extra_Accessibility
(Formal
));
3124 -- If the actual access parameter does not have an
3125 -- associated extra formal providing its scope level,
3126 -- then treat the actual as having library-level
3132 Make_Integer_Literal
(Loc
,
3133 Intval
=> Scope_Depth
(Standard_Standard
)),
3134 EF
=> Extra_Accessibility
(Formal
));
3138 -- The actual is a normal access value, so just pass the level
3139 -- of the actual's access type.
3143 (Expr
=> Dynamic_Accessibility_Level
(Prev_Orig
),
3144 EF
=> Extra_Accessibility
(Formal
));
3147 -- If the actual is an access discriminant, then pass the level
3148 -- of the enclosing object (RM05-3.10.2(12.4/2)).
3150 elsif Nkind
(Prev_Orig
) = N_Selected_Component
3151 and then Ekind
(Entity
(Selector_Name
(Prev_Orig
))) =
3153 and then Ekind
(Etype
(Entity
(Selector_Name
(Prev_Orig
)))) =
3154 E_Anonymous_Access_Type
3158 Make_Integer_Literal
(Loc
,
3159 Intval
=> Object_Access_Level
(Prefix
(Prev_Orig
))),
3160 EF
=> Extra_Accessibility
(Formal
));
3165 case Nkind
(Prev_Orig
) is
3166 when N_Attribute_Reference
=>
3167 case Get_Attribute_Id
(Attribute_Name
(Prev_Orig
)) is
3169 -- For X'Access, pass on the level of the prefix X
3171 when Attribute_Access
=>
3173 -- Accessibility level of S'Access is that of A
3175 Prev_Orig
:= Prefix
(Prev_Orig
);
3177 -- If the expression is a view conversion, the
3178 -- accessibility level is that of the expression.
3180 if Nkind
(Original_Node
(Prev_Orig
)) =
3183 Nkind
(Expression
(Original_Node
(Prev_Orig
))) =
3184 N_Explicit_Dereference
3187 Expression
(Original_Node
(Prev_Orig
));
3190 -- If this is an Access attribute applied to the
3191 -- the current instance object passed to a type
3192 -- initialization procedure, then use the level
3193 -- of the type itself. This is not really correct,
3194 -- as there should be an extra level parameter
3195 -- passed in with _init formals (only in the case
3196 -- where the type is immutably limited), but we
3197 -- don't have an easy way currently to create such
3198 -- an extra formal (init procs aren't ever frozen).
3199 -- For now we just use the level of the type,
3200 -- which may be too shallow, but that works better
3201 -- than passing Object_Access_Level of the type,
3202 -- which can be one level too deep in some cases.
3205 -- A further case that requires special handling
3206 -- is the common idiom E.all'access. If E is a
3207 -- formal of the enclosing subprogram, the
3208 -- accessibility of the expression is that of E.
3210 if Is_Entity_Name
(Prev_Orig
) then
3211 Pref_Entity
:= Entity
(Prev_Orig
);
3213 elsif Nkind
(Prev_Orig
) = N_Explicit_Dereference
3214 and then Is_Entity_Name
(Prefix
(Prev_Orig
))
3216 Pref_Entity
:= Entity
(Prefix
((Prev_Orig
)));
3219 Pref_Entity
:= Empty
;
3222 if Is_Entity_Name
(Prev_Orig
)
3223 and then Is_Type
(Entity
(Prev_Orig
))
3227 Make_Integer_Literal
(Loc
,
3229 Type_Access_Level
(Pref_Entity
)),
3230 EF
=> Extra_Accessibility
(Formal
));
3232 elsif Nkind
(Prev_Orig
) = N_Explicit_Dereference
3233 and then Present
(Pref_Entity
)
3234 and then Is_Formal
(Pref_Entity
)
3236 (Extra_Accessibility
(Pref_Entity
))
3241 (Extra_Accessibility
(Pref_Entity
), Loc
),
3242 EF
=> Extra_Accessibility
(Formal
));
3247 Make_Integer_Literal
(Loc
,
3249 Object_Access_Level
(Prev_Orig
)),
3250 EF
=> Extra_Accessibility
(Formal
));
3253 -- Treat the unchecked attributes as library-level
3255 when Attribute_Unchecked_Access
3256 | Attribute_Unrestricted_Access
3260 Make_Integer_Literal
(Loc
,
3261 Intval
=> Scope_Depth
(Standard_Standard
)),
3262 EF
=> Extra_Accessibility
(Formal
));
3264 -- No other cases of attributes returning access
3265 -- values that can be passed to access parameters.
3268 raise Program_Error
;
3272 -- For allocators we pass the level of the execution of the
3273 -- called subprogram, which is one greater than the current
3279 Make_Integer_Literal
(Loc
,
3280 Intval
=> Scope_Depth
(Current_Scope
) + 1),
3281 EF
=> Extra_Accessibility
(Formal
));
3283 -- For most other cases we simply pass the level of the
3284 -- actual's access type. The type is retrieved from
3285 -- Prev rather than Prev_Orig, because in some cases
3286 -- Prev_Orig denotes an original expression that has
3287 -- not been analyzed.
3291 (Expr
=> Dynamic_Accessibility_Level
(Prev
),
3292 EF
=> Extra_Accessibility
(Formal
));
3297 -- Perform the check of 4.6(49) that prevents a null value from being
3298 -- passed as an actual to an access parameter. Note that the check
3299 -- is elided in the common cases of passing an access attribute or
3300 -- access parameter as an actual. Also, we currently don't enforce
3301 -- this check for expander-generated actuals and when -gnatdj is set.
3303 if Ada_Version
>= Ada_2005
then
3305 -- Ada 2005 (AI-231): Check null-excluding access types. Note that
3306 -- the intent of 6.4.1(13) is that null-exclusion checks should
3307 -- not be done for 'out' parameters, even though it refers only
3308 -- to constraint checks, and a null_exclusion is not a constraint.
3309 -- Note that AI05-0196-1 corrects this mistake in the RM.
3311 if Is_Access_Type
(Etype
(Formal
))
3312 and then Can_Never_Be_Null
(Etype
(Formal
))
3313 and then Ekind
(Formal
) /= E_Out_Parameter
3314 and then Nkind
(Prev
) /= N_Raise_Constraint_Error
3315 and then (Known_Null
(Prev
)
3316 or else not Can_Never_Be_Null
(Etype
(Prev
)))
3318 Install_Null_Excluding_Check
(Prev
);
3321 -- Ada_Version < Ada_2005
3324 if Ekind
(Etype
(Formal
)) /= E_Anonymous_Access_Type
3325 or else Access_Checks_Suppressed
(Subp
)
3329 elsif Debug_Flag_J
then
3332 elsif not Comes_From_Source
(Prev
) then
3335 elsif Is_Entity_Name
(Prev
)
3336 and then Ekind
(Etype
(Prev
)) = E_Anonymous_Access_Type
3340 elsif Nkind_In
(Prev
, N_Allocator
, N_Attribute_Reference
) then
3344 Install_Null_Excluding_Check
(Prev
);
3348 -- Perform appropriate validity checks on parameters that
3351 if Validity_Checks_On
then
3352 if (Ekind
(Formal
) = E_In_Parameter
3353 and then Validity_Check_In_Params
)
3355 (Ekind
(Formal
) = E_In_Out_Parameter
3356 and then Validity_Check_In_Out_Params
)
3358 -- If the actual is an indexed component of a packed type (or
3359 -- is an indexed or selected component whose prefix recursively
3360 -- meets this condition), it has not been expanded yet. It will
3361 -- be copied in the validity code that follows, and has to be
3362 -- expanded appropriately, so reanalyze it.
3364 -- What we do is just to unset analyzed bits on prefixes till
3365 -- we reach something that does not have a prefix.
3372 while Nkind_In
(Nod
, N_Indexed_Component
,
3373 N_Selected_Component
)
3375 Set_Analyzed
(Nod
, False);
3376 Nod
:= Prefix
(Nod
);
3380 Ensure_Valid
(Actual
);
3384 -- For IN OUT and OUT parameters, ensure that subscripts are valid
3385 -- since this is a left side reference. We only do this for calls
3386 -- from the source program since we assume that compiler generated
3387 -- calls explicitly generate any required checks. We also need it
3388 -- only if we are doing standard validity checks, since clearly it is
3389 -- not needed if validity checks are off, and in subscript validity
3390 -- checking mode, all indexed components are checked with a call
3391 -- directly from Expand_N_Indexed_Component.
3393 if Comes_From_Source
(Call_Node
)
3394 and then Ekind
(Formal
) /= E_In_Parameter
3395 and then Validity_Checks_On
3396 and then Validity_Check_Default
3397 and then not Validity_Check_Subscripts
3399 Check_Valid_Lvalue_Subscripts
(Actual
);
3402 -- Mark any scalar OUT parameter that is a simple variable as no
3403 -- longer known to be valid (unless the type is always valid). This
3404 -- reflects the fact that if an OUT parameter is never set in a
3405 -- procedure, then it can become invalid on the procedure return.
3407 if Ekind
(Formal
) = E_Out_Parameter
3408 and then Is_Entity_Name
(Actual
)
3409 and then Ekind
(Entity
(Actual
)) = E_Variable
3410 and then not Is_Known_Valid
(Etype
(Actual
))
3412 Set_Is_Known_Valid
(Entity
(Actual
), False);
3415 -- For an OUT or IN OUT parameter, if the actual is an entity, then
3416 -- clear current values, since they can be clobbered. We are probably
3417 -- doing this in more places than we need to, but better safe than
3418 -- sorry when it comes to retaining bad current values.
3420 if Ekind
(Formal
) /= E_In_Parameter
3421 and then Is_Entity_Name
(Actual
)
3422 and then Present
(Entity
(Actual
))
3425 Ent
: constant Entity_Id
:= Entity
(Actual
);
3429 -- For an OUT or IN OUT parameter that is an assignable entity,
3430 -- we do not want to clobber the Last_Assignment field, since
3431 -- if it is set, it was precisely because it is indeed an OUT
3432 -- or IN OUT parameter. We do reset the Is_Known_Valid flag
3433 -- since the subprogram could have returned in invalid value.
3435 if Ekind_In
(Formal
, E_Out_Parameter
, E_In_Out_Parameter
)
3436 and then Is_Assignable
(Ent
)
3438 Sav
:= Last_Assignment
(Ent
);
3439 Kill_Current_Values
(Ent
);
3440 Set_Last_Assignment
(Ent
, Sav
);
3441 Set_Is_Known_Valid
(Ent
, False);
3442 Set_Is_True_Constant
(Ent
, False);
3444 -- For all other cases, just kill the current values
3447 Kill_Current_Values
(Ent
);
3452 -- If the formal is class wide and the actual is an aggregate, force
3453 -- evaluation so that the back end who does not know about class-wide
3454 -- type, does not generate a temporary of the wrong size.
3456 if not Is_Class_Wide_Type
(Etype
(Formal
)) then
3459 elsif Nkind
(Actual
) = N_Aggregate
3460 or else (Nkind
(Actual
) = N_Qualified_Expression
3461 and then Nkind
(Expression
(Actual
)) = N_Aggregate
)
3463 Force_Evaluation
(Actual
);
3466 -- In a remote call, if the formal is of a class-wide type, check
3467 -- that the actual meets the requirements described in E.4(18).
3469 if Remote
and then Is_Class_Wide_Type
(Etype
(Formal
)) then
3470 Insert_Action
(Actual
,
3471 Make_Transportable_Check
(Loc
,
3472 Duplicate_Subexpr_Move_Checks
(Actual
)));
3475 -- Perform invariant checks for all intermediate types in a view
3476 -- conversion after successful return from a call that passes the
3477 -- view conversion as an IN OUT or OUT parameter (RM 7.3.2 (12/3,
3478 -- 13/3, 14/3)). Consider only source conversion in order to avoid
3479 -- generating spurious checks on complex expansion such as object
3480 -- initialization through an extension aggregate.
3482 if Comes_From_Source
(N
)
3483 and then Ekind
(Formal
) /= E_In_Parameter
3484 and then Nkind
(Actual
) = N_Type_Conversion
3486 Add_View_Conversion_Invariants
(Formal
, Actual
);
3489 -- Generating C the initialization of an allocator is performed by
3490 -- means of individual statements, and hence it must be done before
3493 if Modify_Tree_For_C
3494 and then Nkind
(Actual
) = N_Allocator
3495 and then Nkind
(Expression
(Actual
)) = N_Qualified_Expression
3497 Remove_Side_Effects
(Actual
);
3500 -- This label is required when skipping extra actual generation for
3501 -- Unchecked_Union parameters.
3503 <<Skip_Extra_Actual_Generation
>>
3505 Param_Count
:= Param_Count
+ 1;
3506 Next_Actual
(Actual
);
3507 Next_Formal
(Formal
);
3510 -- If we are calling an Ada 2012 function which needs to have the
3511 -- "accessibility level determined by the point of call" (AI05-0234)
3512 -- passed in to it, then pass it in.
3514 if Ekind_In
(Subp
, E_Function
, E_Operator
, E_Subprogram_Type
)
3516 Present
(Extra_Accessibility_Of_Result
(Ultimate_Alias
(Subp
)))
3519 Ancestor
: Node_Id
:= Parent
(Call_Node
);
3520 Level
: Node_Id
:= Empty
;
3521 Defer
: Boolean := False;
3524 -- Unimplemented: if Subp returns an anonymous access type, then
3526 -- a) if the call is the operand of an explict conversion, then
3527 -- the target type of the conversion (a named access type)
3528 -- determines the accessibility level pass in;
3530 -- b) if the call defines an access discriminant of an object
3531 -- (e.g., the discriminant of an object being created by an
3532 -- allocator, or the discriminant of a function result),
3533 -- then the accessibility level to pass in is that of the
3534 -- discriminated object being initialized).
3538 while Nkind
(Ancestor
) = N_Qualified_Expression
3540 Ancestor
:= Parent
(Ancestor
);
3543 case Nkind
(Ancestor
) is
3546 -- At this point, we'd like to assign
3548 -- Level := Dynamic_Accessibility_Level (Ancestor);
3550 -- but Etype of Ancestor may not have been set yet,
3551 -- so that doesn't work.
3553 -- Handle this later in Expand_Allocator_Expression.
3557 when N_Object_Declaration
3558 | N_Object_Renaming_Declaration
3561 Def_Id
: constant Entity_Id
:=
3562 Defining_Identifier
(Ancestor
);
3565 if Is_Return_Object
(Def_Id
) then
3566 if Present
(Extra_Accessibility_Of_Result
3567 (Return_Applies_To
(Scope
(Def_Id
))))
3569 -- Pass along value that was passed in if the
3570 -- routine we are returning from also has an
3571 -- Accessibility_Of_Result formal.
3575 (Extra_Accessibility_Of_Result
3576 (Return_Applies_To
(Scope
(Def_Id
))), Loc
);
3580 Make_Integer_Literal
(Loc
,
3581 Intval
=> Object_Access_Level
(Def_Id
));
3585 when N_Simple_Return_Statement
=>
3586 if Present
(Extra_Accessibility_Of_Result
3588 (Return_Statement_Entity
(Ancestor
))))
3590 -- Pass along value that was passed in if the returned
3591 -- routine also has an Accessibility_Of_Result formal.
3595 (Extra_Accessibility_Of_Result
3597 (Return_Statement_Entity
(Ancestor
))), Loc
);
3605 if not Present
(Level
) then
3607 -- The "innermost master that evaluates the function call".
3609 -- ??? - Should we use Integer'Last here instead in order
3610 -- to deal with (some of) the problems associated with
3611 -- calls to subps whose enclosing scope is unknown (e.g.,
3612 -- Anon_Access_To_Subp_Param.all)?
3615 Make_Integer_Literal
(Loc
,
3616 Intval
=> Scope_Depth
(Current_Scope
) + 1);
3622 Extra_Accessibility_Of_Result
(Ultimate_Alias
(Subp
)));
3627 -- If we are expanding the RHS of an assignment we need to check if tag
3628 -- propagation is needed. You might expect this processing to be in
3629 -- Analyze_Assignment but has to be done earlier (bottom-up) because the
3630 -- assignment might be transformed to a declaration for an unconstrained
3631 -- value if the expression is classwide.
3633 if Nkind
(Call_Node
) = N_Function_Call
3634 and then Is_Tag_Indeterminate
(Call_Node
)
3635 and then Is_Entity_Name
(Name
(Call_Node
))
3638 Ass
: Node_Id
:= Empty
;
3641 if Nkind
(Parent
(Call_Node
)) = N_Assignment_Statement
then
3642 Ass
:= Parent
(Call_Node
);
3644 elsif Nkind
(Parent
(Call_Node
)) = N_Qualified_Expression
3645 and then Nkind
(Parent
(Parent
(Call_Node
))) =
3646 N_Assignment_Statement
3648 Ass
:= Parent
(Parent
(Call_Node
));
3650 elsif Nkind
(Parent
(Call_Node
)) = N_Explicit_Dereference
3651 and then Nkind
(Parent
(Parent
(Call_Node
))) =
3652 N_Assignment_Statement
3654 Ass
:= Parent
(Parent
(Call_Node
));
3658 and then Is_Class_Wide_Type
(Etype
(Name
(Ass
)))
3660 if Is_Access_Type
(Etype
(Call_Node
)) then
3661 if Designated_Type
(Etype
(Call_Node
)) /=
3662 Root_Type
(Etype
(Name
(Ass
)))
3665 ("tag-indeterminate expression must have designated "
3666 & "type& (RM 5.2 (6))",
3667 Call_Node
, Root_Type
(Etype
(Name
(Ass
))));
3669 Propagate_Tag
(Name
(Ass
), Call_Node
);
3672 elsif Etype
(Call_Node
) /= Root_Type
(Etype
(Name
(Ass
))) then
3674 ("tag-indeterminate expression must have type & "
3676 Call_Node
, Root_Type
(Etype
(Name
(Ass
))));
3679 Propagate_Tag
(Name
(Ass
), Call_Node
);
3682 -- The call will be rewritten as a dispatching call, and
3683 -- expanded as such.
3690 -- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
3691 -- it to point to the correct secondary virtual table
3693 if Nkind
(Call_Node
) in N_Subprogram_Call
3694 and then CW_Interface_Formals_Present
3696 Expand_Interface_Actuals
(Call_Node
);
3699 -- Deals with Dispatch_Call if we still have a call, before expanding
3700 -- extra actuals since this will be done on the re-analysis of the
3701 -- dispatching call. Note that we do not try to shorten the actual list
3702 -- for a dispatching call, it would not make sense to do so. Expansion
3703 -- of dispatching calls is suppressed for VM targets, because the VM
3704 -- back-ends directly handle the generation of dispatching calls and
3705 -- would have to undo any expansion to an indirect call.
3707 if Nkind
(Call_Node
) in N_Subprogram_Call
3708 and then Present
(Controlling_Argument
(Call_Node
))
3711 Call_Typ
: constant Entity_Id
:= Etype
(Call_Node
);
3712 Typ
: constant Entity_Id
:= Find_Dispatching_Type
(Subp
);
3713 Eq_Prim_Op
: Entity_Id
:= Empty
;
3716 Prev_Call
: Node_Id
;
3719 if not Is_Limited_Type
(Typ
) then
3720 Eq_Prim_Op
:= Find_Prim_Op
(Typ
, Name_Op_Eq
);
3723 if Tagged_Type_Expansion
then
3724 Expand_Dispatching_Call
(Call_Node
);
3726 -- The following return is worrisome. Is it really OK to skip
3727 -- all remaining processing in this procedure ???
3734 Apply_Tag_Checks
(Call_Node
);
3736 -- If this is a dispatching "=", we must first compare the
3737 -- tags so we generate: x.tag = y.tag and then x = y
3739 if Subp
= Eq_Prim_Op
then
3741 -- Mark the node as analyzed to avoid reanalyzing this
3742 -- dispatching call (which would cause a never-ending loop)
3744 Prev_Call
:= Relocate_Node
(Call_Node
);
3745 Set_Analyzed
(Prev_Call
);
3747 Param
:= First_Actual
(Call_Node
);
3753 Make_Selected_Component
(Loc
,
3754 Prefix
=> New_Value
(Param
),
3757 (First_Tag_Component
(Typ
), Loc
)),
3760 Make_Selected_Component
(Loc
,
3762 Unchecked_Convert_To
(Typ
,
3763 New_Value
(Next_Actual
(Param
))),
3766 (First_Tag_Component
(Typ
), Loc
))),
3767 Right_Opnd
=> Prev_Call
);
3769 Rewrite
(Call_Node
, New_Call
);
3772 (Call_Node
, Call_Typ
, Suppress
=> All_Checks
);
3775 -- Expansion of a dispatching call results in an indirect call,
3776 -- which in turn causes current values to be killed (see
3777 -- Resolve_Call), so on VM targets we do the call here to
3778 -- ensure consistent warnings between VM and non-VM targets.
3780 Kill_Current_Values
;
3783 -- If this is a dispatching "=" then we must update the reference
3784 -- to the call node because we generated:
3785 -- x.tag = y.tag and then x = y
3787 if Subp
= Eq_Prim_Op
then
3788 Call_Node
:= Right_Opnd
(Call_Node
);
3793 -- Similarly, expand calls to RCI subprograms on which pragma
3794 -- All_Calls_Remote applies. The rewriting will be reanalyzed
3795 -- later. Do this only when the call comes from source since we
3796 -- do not want such a rewriting to occur in expanded code.
3798 if Is_All_Remote_Call
(Call_Node
) then
3799 Expand_All_Calls_Remote_Subprogram_Call
(Call_Node
);
3801 -- Similarly, do not add extra actuals for an entry call whose entity
3802 -- is a protected procedure, or for an internal protected subprogram
3803 -- call, because it will be rewritten as a protected subprogram call
3804 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
3806 elsif Is_Protected_Type
(Scope
(Subp
))
3807 and then (Ekind
(Subp
) = E_Procedure
3808 or else Ekind
(Subp
) = E_Function
)
3812 -- During that loop we gathered the extra actuals (the ones that
3813 -- correspond to Extra_Formals), so now they can be appended.
3816 while Is_Non_Empty_List
(Extra_Actuals
) loop
3817 Add_Actual_Parameter
(Remove_Head
(Extra_Actuals
));
3821 -- At this point we have all the actuals, so this is the point at which
3822 -- the various expansion activities for actuals is carried out.
3824 Expand_Actuals
(Call_Node
, Subp
, Post_Call
);
3826 -- Verify that the actuals do not share storage. This check must be done
3827 -- on the caller side rather that inside the subprogram to avoid issues
3828 -- of parameter passing.
3830 if Check_Aliasing_Of_Parameters
then
3831 Apply_Parameter_Aliasing_Checks
(Call_Node
, Subp
);
3834 -- If the subprogram is a renaming, or if it is inherited, replace it in
3835 -- the call with the name of the actual subprogram being called. If this
3836 -- is a dispatching call, the run-time decides what to call. The Alias
3837 -- attribute does not apply to entries.
3839 if Nkind
(Call_Node
) /= N_Entry_Call_Statement
3840 and then No
(Controlling_Argument
(Call_Node
))
3841 and then Present
(Parent_Subp
)
3842 and then not Is_Direct_Deep_Call
(Subp
)
3844 if Present
(Inherited_From_Formal
(Subp
)) then
3845 Parent_Subp
:= Inherited_From_Formal
(Subp
);
3847 Parent_Subp
:= Ultimate_Alias
(Parent_Subp
);
3850 -- The below setting of Entity is suspect, see F109-018 discussion???
3852 Set_Entity
(Name
(Call_Node
), Parent_Subp
);
3854 if Is_Abstract_Subprogram
(Parent_Subp
)
3855 and then not In_Instance
3858 ("cannot call abstract subprogram &!",
3859 Name
(Call_Node
), Parent_Subp
);
3862 -- Inspect all formals of derived subprogram Subp. Compare parameter
3863 -- types with the parent subprogram and check whether an actual may
3864 -- need a type conversion to the corresponding formal of the parent
3867 -- Not clear whether intrinsic subprograms need such conversions. ???
3869 if not Is_Intrinsic_Subprogram
(Parent_Subp
)
3870 or else Is_Generic_Instance
(Parent_Subp
)
3873 procedure Convert
(Act
: Node_Id
; Typ
: Entity_Id
);
3874 -- Rewrite node Act as a type conversion of Act to Typ. Analyze
3875 -- and resolve the newly generated construct.
3881 procedure Convert
(Act
: Node_Id
; Typ
: Entity_Id
) is
3883 Rewrite
(Act
, OK_Convert_To
(Typ
, Relocate_Node
(Act
)));
3890 Actual_Typ
: Entity_Id
;
3891 Formal_Typ
: Entity_Id
;
3892 Parent_Typ
: Entity_Id
;
3895 Actual
:= First_Actual
(Call_Node
);
3896 Formal
:= First_Formal
(Subp
);
3897 Parent_Formal
:= First_Formal
(Parent_Subp
);
3898 while Present
(Formal
) loop
3899 Actual_Typ
:= Etype
(Actual
);
3900 Formal_Typ
:= Etype
(Formal
);
3901 Parent_Typ
:= Etype
(Parent_Formal
);
3903 -- For an IN parameter of a scalar type, the parent formal
3904 -- type and derived formal type differ or the parent formal
3905 -- type and actual type do not match statically.
3907 if Is_Scalar_Type
(Formal_Typ
)
3908 and then Ekind
(Formal
) = E_In_Parameter
3909 and then Formal_Typ
/= Parent_Typ
3911 not Subtypes_Statically_Match
(Parent_Typ
, Actual_Typ
)
3912 and then not Raises_Constraint_Error
(Actual
)
3914 Convert
(Actual
, Parent_Typ
);
3915 Enable_Range_Check
(Actual
);
3917 -- If the actual has been marked as requiring a range
3918 -- check, then generate it here.
3920 if Do_Range_Check
(Actual
) then
3921 Generate_Range_Check
3922 (Actual
, Etype
(Formal
), CE_Range_Check_Failed
);
3925 -- For access types, the parent formal type and actual type
3928 elsif Is_Access_Type
(Formal_Typ
)
3929 and then Base_Type
(Parent_Typ
) /= Base_Type
(Actual_Typ
)
3931 if Ekind
(Formal
) /= E_In_Parameter
then
3932 Convert
(Actual
, Parent_Typ
);
3934 elsif Ekind
(Parent_Typ
) = E_Anonymous_Access_Type
3935 and then Designated_Type
(Parent_Typ
) /=
3936 Designated_Type
(Actual_Typ
)
3937 and then not Is_Controlling_Formal
(Formal
)
3939 -- This unchecked conversion is not necessary unless
3940 -- inlining is enabled, because in that case the type
3941 -- mismatch may become visible in the body about to be
3945 Unchecked_Convert_To
(Parent_Typ
,
3946 Relocate_Node
(Actual
)));
3948 Resolve
(Actual
, Parent_Typ
);
3951 -- If there is a change of representation, then generate a
3952 -- warning, and do the change of representation.
3954 elsif not Same_Representation
(Formal_Typ
, Parent_Typ
) then
3956 ("??change of representation required", Actual
);
3957 Convert
(Actual
, Parent_Typ
);
3959 -- For array and record types, the parent formal type and
3960 -- derived formal type have different sizes or pragma Pack
3963 elsif ((Is_Array_Type
(Formal_Typ
)
3964 and then Is_Array_Type
(Parent_Typ
))
3966 (Is_Record_Type
(Formal_Typ
)
3967 and then Is_Record_Type
(Parent_Typ
)))
3969 (Esize
(Formal_Typ
) /= Esize
(Parent_Typ
)
3970 or else Has_Pragma_Pack
(Formal_Typ
) /=
3971 Has_Pragma_Pack
(Parent_Typ
))
3973 Convert
(Actual
, Parent_Typ
);
3976 Next_Actual
(Actual
);
3977 Next_Formal
(Formal
);
3978 Next_Formal
(Parent_Formal
);
3984 Subp
:= Parent_Subp
;
3987 -- Deal with case where call is an explicit dereference
3989 if Nkind
(Name
(Call_Node
)) = N_Explicit_Dereference
then
3991 -- Handle case of access to protected subprogram type
3993 if Is_Access_Protected_Subprogram_Type
3994 (Base_Type
(Etype
(Prefix
(Name
(Call_Node
)))))
3996 -- If this is a call through an access to protected operation, the
3997 -- prefix has the form (object'address, operation'access). Rewrite
3998 -- as a for other protected calls: the object is the 1st parameter
3999 -- of the list of actuals.
4006 Ptr
: constant Node_Id
:= Prefix
(Name
(Call_Node
));
4008 T
: constant Entity_Id
:=
4009 Equivalent_Type
(Base_Type
(Etype
(Ptr
)));
4011 D_T
: constant Entity_Id
:=
4012 Designated_Type
(Base_Type
(Etype
(Ptr
)));
4016 Make_Selected_Component
(Loc
,
4017 Prefix
=> Unchecked_Convert_To
(T
, Ptr
),
4019 New_Occurrence_Of
(First_Entity
(T
), Loc
));
4022 Make_Selected_Component
(Loc
,
4023 Prefix
=> Unchecked_Convert_To
(T
, Ptr
),
4025 New_Occurrence_Of
(Next_Entity
(First_Entity
(T
)), Loc
));
4028 Make_Explicit_Dereference
(Loc
,
4031 if Present
(Parameter_Associations
(Call_Node
)) then
4032 Parm
:= Parameter_Associations
(Call_Node
);
4037 Prepend
(Obj
, Parm
);
4039 if Etype
(D_T
) = Standard_Void_Type
then
4041 Make_Procedure_Call_Statement
(Loc
,
4043 Parameter_Associations
=> Parm
);
4046 Make_Function_Call
(Loc
,
4048 Parameter_Associations
=> Parm
);
4051 Set_First_Named_Actual
(Call
, First_Named_Actual
(Call_Node
));
4052 Set_Etype
(Call
, Etype
(D_T
));
4054 -- We do not re-analyze the call to avoid infinite recursion.
4055 -- We analyze separately the prefix and the object, and set
4056 -- the checks on the prefix that would otherwise be emitted
4057 -- when resolving a call.
4059 Rewrite
(Call_Node
, Call
);
4061 Apply_Access_Check
(Nam
);
4068 -- If this is a call to an intrinsic subprogram, then perform the
4069 -- appropriate expansion to the corresponding tree node and we
4070 -- are all done (since after that the call is gone).
4072 -- In the case where the intrinsic is to be processed by the back end,
4073 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
4074 -- since the idea in this case is to pass the call unchanged. If the
4075 -- intrinsic is an inherited unchecked conversion, and the derived type
4076 -- is the target type of the conversion, we must retain it as the return
4077 -- type of the expression. Otherwise the expansion below, which uses the
4078 -- parent operation, will yield the wrong type.
4080 if Is_Intrinsic_Subprogram
(Subp
) then
4081 Expand_Intrinsic_Call
(Call_Node
, Subp
);
4083 if Nkind
(Call_Node
) = N_Unchecked_Type_Conversion
4084 and then Parent_Subp
/= Orig_Subp
4085 and then Etype
(Parent_Subp
) /= Etype
(Orig_Subp
)
4087 Set_Etype
(Call_Node
, Etype
(Orig_Subp
));
4093 if Ekind_In
(Subp
, E_Function
, E_Procedure
) then
4095 -- We perform a simple optimization on calls for To_Address by
4096 -- replacing them with an unchecked conversion. Not only is this
4097 -- efficient, but it also avoids order of elaboration problems when
4098 -- address clauses are inlined (address expression elaborated at the
4101 -- We perform this optimization regardless of whether we are in the
4102 -- main unit or in a unit in the context of the main unit, to ensure
4103 -- that the generated tree is the same in both cases, for CodePeer
4106 if Is_RTE
(Subp
, RE_To_Address
) then
4108 Unchecked_Convert_To
4109 (RTE
(RE_Address
), Relocate_Node
(First_Actual
(Call_Node
))));
4112 -- A call to a null procedure is replaced by a null statement, but we
4113 -- are not allowed to ignore possible side effects of the call, so we
4114 -- make sure that actuals are evaluated.
4115 -- We also suppress this optimization for GNATCoverage.
4117 elsif Is_Null_Procedure
(Subp
)
4118 and then not Opt
.Suppress_Control_Flow_Optimizations
4120 Actual
:= First_Actual
(Call_Node
);
4121 while Present
(Actual
) loop
4122 Remove_Side_Effects
(Actual
);
4123 Next_Actual
(Actual
);
4126 Rewrite
(Call_Node
, Make_Null_Statement
(Loc
));
4130 -- Handle inlining. No action needed if the subprogram is not inlined
4132 if not Is_Inlined
(Subp
) then
4135 -- Frontend inlining of expression functions (performed also when
4136 -- backend inlining is enabled).
4138 elsif Is_Inlinable_Expression_Function
(Subp
) then
4139 Rewrite
(N
, New_Copy
(Expression_Of_Expression_Function
(Subp
)));
4143 -- Handle frontend inlining
4145 elsif not Back_End_Inlining
then
4146 Inlined_Subprogram
: declare
4148 Must_Inline
: Boolean := False;
4149 Spec
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
4152 -- Verify that the body to inline has already been seen, and
4153 -- that if the body is in the current unit the inlining does
4154 -- not occur earlier. This avoids order-of-elaboration problems
4157 -- This should be documented in sinfo/einfo ???
4160 or else Nkind
(Spec
) /= N_Subprogram_Declaration
4161 or else No
(Body_To_Inline
(Spec
))
4163 Must_Inline
:= False;
4165 -- If this an inherited function that returns a private type,
4166 -- do not inline if the full view is an unconstrained array,
4167 -- because such calls cannot be inlined.
4169 elsif Present
(Orig_Subp
)
4170 and then Is_Array_Type
(Etype
(Orig_Subp
))
4171 and then not Is_Constrained
(Etype
(Orig_Subp
))
4173 Must_Inline
:= False;
4175 elsif In_Unfrozen_Instance
(Scope
(Subp
)) then
4176 Must_Inline
:= False;
4179 Bod
:= Body_To_Inline
(Spec
);
4181 if (In_Extended_Main_Code_Unit
(Call_Node
)
4182 or else In_Extended_Main_Code_Unit
(Parent
(Call_Node
))
4183 or else Has_Pragma_Inline_Always
(Subp
))
4184 and then (not In_Same_Extended_Unit
(Sloc
(Bod
), Loc
)
4186 Earlier_In_Extended_Unit
(Sloc
(Bod
), Loc
))
4188 Must_Inline
:= True;
4190 -- If we are compiling a package body that is not the main
4191 -- unit, it must be for inlining/instantiation purposes,
4192 -- in which case we inline the call to insure that the same
4193 -- temporaries are generated when compiling the body by
4194 -- itself. Otherwise link errors can occur.
4196 -- If the function being called is itself in the main unit,
4197 -- we cannot inline, because there is a risk of double
4198 -- elaboration and/or circularity: the inlining can make
4199 -- visible a private entity in the body of the main unit,
4200 -- that gigi will see before its sees its proper definition.
4202 elsif not (In_Extended_Main_Code_Unit
(Call_Node
))
4203 and then In_Package_Body
4205 Must_Inline
:= not In_Extended_Main_Source_Unit
(Subp
);
4207 -- Inline calls to _postconditions when generating C code
4209 elsif Modify_Tree_For_C
4210 and then In_Same_Extended_Unit
(Sloc
(Bod
), Loc
)
4211 and then Chars
(Name
(N
)) = Name_uPostconditions
4213 Must_Inline
:= True;
4218 Expand_Inlined_Call
(Call_Node
, Subp
, Orig_Subp
);
4221 -- Let the back end handle it
4223 Add_Inlined_Body
(Subp
, Call_Node
);
4225 if Front_End_Inlining
4226 and then Nkind
(Spec
) = N_Subprogram_Declaration
4227 and then (In_Extended_Main_Code_Unit
(Call_Node
))
4228 and then No
(Body_To_Inline
(Spec
))
4229 and then not Has_Completion
(Subp
)
4230 and then In_Same_Extended_Unit
(Sloc
(Spec
), Loc
)
4233 ("cannot inline& (body not seen yet)?",
4237 end Inlined_Subprogram
;
4239 -- Back end inlining: let the back end handle it
4241 elsif No
(Unit_Declaration_Node
(Subp
))
4242 or else Nkind
(Unit_Declaration_Node
(Subp
)) /=
4243 N_Subprogram_Declaration
4244 or else No
(Body_To_Inline
(Unit_Declaration_Node
(Subp
)))
4245 or else Nkind
(Body_To_Inline
(Unit_Declaration_Node
(Subp
))) in
4248 Add_Inlined_Body
(Subp
, Call_Node
);
4250 -- If the inlined call appears within an instantiation and some
4251 -- level of optimization is required, ensure that the enclosing
4252 -- instance body is available so that the back-end can actually
4253 -- perform the inlining.
4256 and then Comes_From_Source
(Subp
)
4257 and then Optimization_Level
> 0
4262 Inst_Node
: Node_Id
;
4265 Inst
:= Scope
(Subp
);
4267 -- Find enclosing instance
4269 while Present
(Inst
) and then Inst
/= Standard_Standard
loop
4270 exit when Is_Generic_Instance
(Inst
);
4271 Inst
:= Scope
(Inst
);
4275 and then Is_Generic_Instance
(Inst
)
4276 and then not Is_Inlined
(Inst
)
4278 Set_Is_Inlined
(Inst
);
4279 Decl
:= Unit_Declaration_Node
(Inst
);
4281 -- Do not add a pending instantiation if the body exits
4282 -- already, or if the instance is a compilation unit, or
4283 -- the instance node is missing.
4285 if Present
(Corresponding_Body
(Decl
))
4286 or else Nkind
(Parent
(Decl
)) = N_Compilation_Unit
4287 or else No
(Next
(Decl
))
4292 -- The instantiation node usually follows the package
4293 -- declaration for the instance. If the generic unit
4294 -- has aspect specifications, they are transformed
4295 -- into pragmas in the instance, and the instance node
4296 -- appears after them.
4298 Inst_Node
:= Next
(Decl
);
4300 while Nkind
(Inst_Node
) /= N_Package_Instantiation
loop
4301 Inst_Node
:= Next
(Inst_Node
);
4304 Add_Pending_Instantiation
(Inst_Node
, Decl
);
4310 -- Front end expansion of simple functions returning unconstrained
4311 -- types (see Check_And_Split_Unconstrained_Function). Note that the
4312 -- case of a simple renaming (Body_To_Inline in N_Entity above, see
4313 -- also Build_Renamed_Body) cannot be expanded here because this may
4314 -- give rise to order-of-elaboration issues for the types of the
4315 -- parameters of the subprogram, if any.
4318 Expand_Inlined_Call
(Call_Node
, Subp
, Orig_Subp
);
4322 -- Check for protected subprogram. This is either an intra-object call,
4323 -- or a protected function call. Protected procedure calls are rewritten
4324 -- as entry calls and handled accordingly.
4326 -- In Ada 2005, this may be an indirect call to an access parameter that
4327 -- is an access_to_subprogram. In that case the anonymous type has a
4328 -- scope that is a protected operation, but the call is a regular one.
4329 -- In either case do not expand call if subprogram is eliminated.
4331 Scop
:= Scope
(Subp
);
4333 if Nkind
(Call_Node
) /= N_Entry_Call_Statement
4334 and then Is_Protected_Type
(Scop
)
4335 and then Ekind
(Subp
) /= E_Subprogram_Type
4336 and then not Is_Eliminated
(Subp
)
4338 -- If the call is an internal one, it is rewritten as a call to the
4339 -- corresponding unprotected subprogram.
4341 Expand_Protected_Subprogram_Call
(Call_Node
, Subp
, Scop
);
4344 -- Functions returning controlled objects need special attention. If
4345 -- the return type is limited, then the context is initialization and
4346 -- different processing applies. If the call is to a protected function,
4347 -- the expansion above will call Expand_Call recursively. Otherwise the
4348 -- function call is transformed into a temporary which obtains the
4349 -- result from the secondary stack.
4351 if Needs_Finalization
(Etype
(Subp
)) then
4352 if not Is_Build_In_Place_Function_Call
(Call_Node
)
4354 (No
(First_Formal
(Subp
))
4356 not Is_Concurrent_Record_Type
(Etype
(First_Formal
(Subp
))))
4358 Expand_Ctrl_Function_Call
(Call_Node
);
4360 -- Build-in-place function calls which appear in anonymous contexts
4361 -- need a transient scope to ensure the proper finalization of the
4362 -- intermediate result after its use.
4364 elsif Is_Build_In_Place_Function_Call
(Call_Node
)
4365 and then Nkind_In
(Parent
(Unqual_Conv
(Call_Node
)),
4366 N_Attribute_Reference
,
4368 N_Indexed_Component
,
4369 N_Object_Renaming_Declaration
,
4370 N_Procedure_Call_Statement
,
4371 N_Selected_Component
,
4374 (Ekind
(Current_Scope
) /= E_Loop
4375 or else Nkind
(Parent
(N
)) /= N_Function_Call
4376 or else not Is_Build_In_Place_Function_Call
(Parent
(N
)))
4378 Establish_Transient_Scope
(Call_Node
, Manage_Sec_Stack
=> True);
4381 end Expand_Call_Helper
;
4383 -------------------------------
4384 -- Expand_Ctrl_Function_Call --
4385 -------------------------------
4387 procedure Expand_Ctrl_Function_Call
(N
: Node_Id
) is
4388 function Is_Element_Reference
(N
: Node_Id
) return Boolean;
4389 -- Determine whether node N denotes a reference to an Ada 2012 container
4392 --------------------------
4393 -- Is_Element_Reference --
4394 --------------------------
4396 function Is_Element_Reference
(N
: Node_Id
) return Boolean is
4397 Ref
: constant Node_Id
:= Original_Node
(N
);
4400 -- Analysis marks an element reference by setting the generalized
4401 -- indexing attribute of an indexed component before the component
4402 -- is rewritten into a function call.
4405 Nkind
(Ref
) = N_Indexed_Component
4406 and then Present
(Generalized_Indexing
(Ref
));
4407 end Is_Element_Reference
;
4409 -- Start of processing for Expand_Ctrl_Function_Call
4412 -- Optimization, if the returned value (which is on the sec-stack) is
4413 -- returned again, no need to copy/readjust/finalize, we can just pass
4414 -- the value thru (see Expand_N_Simple_Return_Statement), and thus no
4415 -- attachment is needed
4417 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
then
4421 -- Resolution is now finished, make sure we don't start analysis again
4422 -- because of the duplication.
4426 -- A function which returns a controlled object uses the secondary
4427 -- stack. Rewrite the call into a temporary which obtains the result of
4428 -- the function using 'reference.
4430 Remove_Side_Effects
(N
);
4432 -- The side effect removal of the function call produced a temporary.
4433 -- When the context is a case expression, if expression, or expression
4434 -- with actions, the lifetime of the temporary must be extended to match
4435 -- that of the context. Otherwise the function result will be finalized
4436 -- too early and affect the result of the expression. To prevent this
4437 -- unwanted effect, the temporary should not be considered for clean up
4438 -- actions by the general finalization machinery.
4440 -- Exception to this rule are references to Ada 2012 container elements.
4441 -- Such references must be finalized at the end of each iteration of the
4442 -- related quantified expression, otherwise the container will remain
4445 if Nkind
(N
) = N_Explicit_Dereference
4446 and then Within_Case_Or_If_Expression
(N
)
4447 and then not Is_Element_Reference
(N
)
4449 Set_Is_Ignored_Transient
(Entity
(Prefix
(N
)));
4451 end Expand_Ctrl_Function_Call
;
4453 ----------------------------------------
4454 -- Expand_N_Extended_Return_Statement --
4455 ----------------------------------------
4457 -- If there is a Handled_Statement_Sequence, we rewrite this:
4459 -- return Result : T := <expression> do
4460 -- <handled_seq_of_stms>
4466 -- Result : T := <expression>;
4468 -- <handled_seq_of_stms>
4472 -- Otherwise (no Handled_Statement_Sequence), we rewrite this:
4474 -- return Result : T := <expression>;
4478 -- return <expression>;
4480 -- unless it's build-in-place or there's no <expression>, in which case
4484 -- Result : T := <expression>;
4489 -- Note that this case could have been written by the user as an extended
4490 -- return statement, or could have been transformed to this from a simple
4491 -- return statement.
4493 -- That is, we need to have a reified return object if there are statements
4494 -- (which might refer to it) or if we're doing build-in-place (so we can
4495 -- set its address to the final resting place or if there is no expression
4496 -- (in which case default initial values might need to be set)).
4498 procedure Expand_N_Extended_Return_Statement
(N
: Node_Id
) is
4499 Loc
: constant Source_Ptr
:= Sloc
(N
);
4501 function Build_Heap_Or_Pool_Allocator
4502 (Temp_Id
: Entity_Id
;
4503 Temp_Typ
: Entity_Id
;
4504 Func_Id
: Entity_Id
;
4505 Ret_Typ
: Entity_Id
;
4506 Alloc_Expr
: Node_Id
) return Node_Id
;
4507 -- Create the statements necessary to allocate a return object on the
4508 -- heap or user-defined storage pool. The object may need finalization
4509 -- actions depending on the return type.
4511 -- * Controlled case
4513 -- if BIPfinalizationmaster = null then
4514 -- Temp_Id := <Alloc_Expr>;
4517 -- type Ptr_Typ is access Ret_Typ;
4518 -- for Ptr_Typ'Storage_Pool use
4519 -- Base_Pool (BIPfinalizationmaster.all).all;
4523 -- procedure Allocate (...) is
4525 -- System.Storage_Pools.Subpools.Allocate_Any (...);
4528 -- Local := <Alloc_Expr>;
4529 -- Temp_Id := Temp_Typ (Local);
4533 -- * Non-controlled case
4535 -- Temp_Id := <Alloc_Expr>;
4537 -- Temp_Id is the temporary which is used to reference the internally
4538 -- created object in all allocation forms. Temp_Typ is the type of the
4539 -- temporary. Func_Id is the enclosing function. Ret_Typ is the return
4540 -- type of Func_Id. Alloc_Expr is the actual allocator.
4542 function Move_Activation_Chain
(Func_Id
: Entity_Id
) return Node_Id
;
4543 -- Construct a call to System.Tasking.Stages.Move_Activation_Chain
4545 -- From current activation chain
4546 -- To activation chain passed in by the caller
4547 -- New_Master master passed in by the caller
4549 -- Func_Id is the entity of the function where the extended return
4550 -- statement appears.
4552 ----------------------------------
4553 -- Build_Heap_Or_Pool_Allocator --
4554 ----------------------------------
4556 function Build_Heap_Or_Pool_Allocator
4557 (Temp_Id
: Entity_Id
;
4558 Temp_Typ
: Entity_Id
;
4559 Func_Id
: Entity_Id
;
4560 Ret_Typ
: Entity_Id
;
4561 Alloc_Expr
: Node_Id
) return Node_Id
4564 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
4566 -- Processing for objects that require finalization actions
4568 if Needs_Finalization
(Ret_Typ
) then
4570 Decls
: constant List_Id
:= New_List
;
4571 Fin_Mas_Id
: constant Entity_Id
:=
4572 Build_In_Place_Formal
4573 (Func_Id
, BIP_Finalization_Master
);
4574 Orig_Expr
: constant Node_Id
:=
4576 (Source
=> Alloc_Expr
,
4577 Scopes_In_EWA_OK
=> True);
4578 Stmts
: constant List_Id
:= New_List
;
4579 Desig_Typ
: Entity_Id
;
4580 Local_Id
: Entity_Id
;
4581 Pool_Id
: Entity_Id
;
4582 Ptr_Typ
: Entity_Id
;
4586 -- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
4588 Pool_Id
:= Make_Temporary
(Loc
, 'P');
4591 Make_Object_Renaming_Declaration
(Loc
,
4592 Defining_Identifier
=> Pool_Id
,
4594 New_Occurrence_Of
(RTE
(RE_Root_Storage_Pool
), Loc
),
4596 Make_Explicit_Dereference
(Loc
,
4598 Make_Function_Call
(Loc
,
4600 New_Occurrence_Of
(RTE
(RE_Base_Pool
), Loc
),
4601 Parameter_Associations
=> New_List
(
4602 Make_Explicit_Dereference
(Loc
,
4604 New_Occurrence_Of
(Fin_Mas_Id
, Loc
)))))));
4606 -- Create an access type which uses the storage pool of the
4607 -- caller's master. This additional type is necessary because
4608 -- the finalization master cannot be associated with the type
4609 -- of the temporary. Otherwise the secondary stack allocation
4612 Desig_Typ
:= Ret_Typ
;
4614 -- Ensure that the build-in-place machinery uses a fat pointer
4615 -- when allocating an unconstrained array on the heap. In this
4616 -- case the result object type is a constrained array type even
4617 -- though the function type is unconstrained.
4619 if Ekind
(Desig_Typ
) = E_Array_Subtype
then
4620 Desig_Typ
:= Base_Type
(Desig_Typ
);
4624 -- type Ptr_Typ is access Desig_Typ;
4626 Ptr_Typ
:= Make_Temporary
(Loc
, 'P');
4629 Make_Full_Type_Declaration
(Loc
,
4630 Defining_Identifier
=> Ptr_Typ
,
4632 Make_Access_To_Object_Definition
(Loc
,
4633 Subtype_Indication
=>
4634 New_Occurrence_Of
(Desig_Typ
, Loc
))));
4636 -- Perform minor decoration in order to set the master and the
4637 -- storage pool attributes.
4639 Set_Ekind
(Ptr_Typ
, E_Access_Type
);
4640 Set_Finalization_Master
(Ptr_Typ
, Fin_Mas_Id
);
4641 Set_Associated_Storage_Pool
(Ptr_Typ
, Pool_Id
);
4643 -- Create the temporary, generate:
4644 -- Local_Id : Ptr_Typ;
4646 Local_Id
:= Make_Temporary
(Loc
, 'T');
4649 Make_Object_Declaration
(Loc
,
4650 Defining_Identifier
=> Local_Id
,
4651 Object_Definition
=>
4652 New_Occurrence_Of
(Ptr_Typ
, Loc
)));
4654 -- Allocate the object, generate:
4655 -- Local_Id := <Alloc_Expr>;
4658 Make_Assignment_Statement
(Loc
,
4659 Name
=> New_Occurrence_Of
(Local_Id
, Loc
),
4660 Expression
=> Alloc_Expr
));
4663 -- Temp_Id := Temp_Typ (Local_Id);
4666 Make_Assignment_Statement
(Loc
,
4667 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4669 Unchecked_Convert_To
(Temp_Typ
,
4670 New_Occurrence_Of
(Local_Id
, Loc
))));
4672 -- Wrap the allocation in a block. This is further conditioned
4673 -- by checking the caller finalization master at runtime. A
4674 -- null value indicates a non-existent master, most likely due
4675 -- to a Finalize_Storage_Only allocation.
4678 -- if BIPfinalizationmaster = null then
4679 -- Temp_Id := <Orig_Expr>;
4689 Make_If_Statement
(Loc
,
4692 Left_Opnd
=> New_Occurrence_Of
(Fin_Mas_Id
, Loc
),
4693 Right_Opnd
=> Make_Null
(Loc
)),
4695 Then_Statements
=> New_List
(
4696 Make_Assignment_Statement
(Loc
,
4697 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4698 Expression
=> Orig_Expr
)),
4700 Else_Statements
=> New_List
(
4701 Make_Block_Statement
(Loc
,
4702 Declarations
=> Decls
,
4703 Handled_Statement_Sequence
=>
4704 Make_Handled_Sequence_Of_Statements
(Loc
,
4705 Statements
=> Stmts
))));
4708 -- For all other cases, generate:
4709 -- Temp_Id := <Alloc_Expr>;
4713 Make_Assignment_Statement
(Loc
,
4714 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4715 Expression
=> Alloc_Expr
);
4717 end Build_Heap_Or_Pool_Allocator
;
4719 ---------------------------
4720 -- Move_Activation_Chain --
4721 ---------------------------
4723 function Move_Activation_Chain
(Func_Id
: Entity_Id
) return Node_Id
is
4726 Make_Procedure_Call_Statement
(Loc
,
4728 New_Occurrence_Of
(RTE
(RE_Move_Activation_Chain
), Loc
),
4730 Parameter_Associations
=> New_List
(
4734 Make_Attribute_Reference
(Loc
,
4735 Prefix
=> Make_Identifier
(Loc
, Name_uChain
),
4736 Attribute_Name
=> Name_Unrestricted_Access
),
4738 -- Destination chain
4741 (Build_In_Place_Formal
(Func_Id
, BIP_Activation_Chain
), Loc
),
4746 (Build_In_Place_Formal
(Func_Id
, BIP_Task_Master
), Loc
)));
4747 end Move_Activation_Chain
;
4751 Func_Id
: constant Entity_Id
:=
4752 Return_Applies_To
(Return_Statement_Entity
(N
));
4753 Is_BIP_Func
: constant Boolean :=
4754 Is_Build_In_Place_Function
(Func_Id
);
4755 Ret_Obj_Id
: constant Entity_Id
:=
4756 First_Entity
(Return_Statement_Entity
(N
));
4757 Ret_Obj_Decl
: constant Node_Id
:= Parent
(Ret_Obj_Id
);
4758 Ret_Typ
: constant Entity_Id
:= Etype
(Func_Id
);
4765 Return_Stmt
: Node_Id
:= Empty
;
4766 -- Force initialization to facilitate static analysis
4768 -- Start of processing for Expand_N_Extended_Return_Statement
4771 -- Given that functionality of interface thunks is simple (just displace
4772 -- the pointer to the object) they are always handled by means of
4773 -- simple return statements.
4775 pragma Assert
(not Is_Thunk
(Current_Subprogram
));
4777 if Nkind
(Ret_Obj_Decl
) = N_Object_Declaration
then
4778 Exp
:= Expression
(Ret_Obj_Decl
);
4780 -- Assert that if F says "return R : T := G(...) do..."
4781 -- then F and G are both b-i-p, or neither b-i-p.
4783 if Nkind
(Exp
) = N_Function_Call
then
4784 pragma Assert
(Ekind
(Current_Subprogram
) = E_Function
);
4786 (Is_Build_In_Place_Function
(Current_Subprogram
) =
4787 Is_Build_In_Place_Function_Call
(Exp
));
4794 HSS
:= Handled_Statement_Sequence
(N
);
4796 -- If the returned object needs finalization actions, the function must
4797 -- perform the appropriate cleanup should it fail to return. The state
4798 -- of the function itself is tracked through a flag which is coupled
4799 -- with the scope finalizer. There is one flag per each return object
4800 -- in case of multiple returns.
4802 if Is_BIP_Func
and then Needs_Finalization
(Etype
(Ret_Obj_Id
)) then
4804 Flag_Decl
: Node_Id
;
4805 Flag_Id
: Entity_Id
;
4809 -- Recover the function body
4811 Func_Bod
:= Unit_Declaration_Node
(Func_Id
);
4813 if Nkind
(Func_Bod
) = N_Subprogram_Declaration
then
4814 Func_Bod
:= Parent
(Parent
(Corresponding_Body
(Func_Bod
)));
4817 if Nkind
(Func_Bod
) = N_Function_Specification
then
4818 Func_Bod
:= Parent
(Func_Bod
); -- one more level for child units
4821 pragma Assert
(Nkind
(Func_Bod
) = N_Subprogram_Body
);
4823 -- Create a flag to track the function state
4825 Flag_Id
:= Make_Temporary
(Loc
, 'F');
4826 Set_Status_Flag_Or_Transient_Decl
(Ret_Obj_Id
, Flag_Id
);
4828 -- Insert the flag at the beginning of the function declarations,
4830 -- Fnn : Boolean := False;
4833 Make_Object_Declaration
(Loc
,
4834 Defining_Identifier
=> Flag_Id
,
4835 Object_Definition
=>
4836 New_Occurrence_Of
(Standard_Boolean
, Loc
),
4838 New_Occurrence_Of
(Standard_False
, Loc
));
4840 Prepend_To
(Declarations
(Func_Bod
), Flag_Decl
);
4841 Analyze
(Flag_Decl
);
4845 -- Build a simple_return_statement that returns the return object when
4846 -- there is a statement sequence, or no expression, or the result will
4847 -- be built in place. Note however that we currently do this for all
4848 -- composite cases, even though not all are built in place.
4851 or else Is_Composite_Type
(Ret_Typ
)
4857 -- If the extended return has a handled statement sequence, then wrap
4858 -- it in a block and use the block as the first statement.
4862 Make_Block_Statement
(Loc
,
4863 Declarations
=> New_List
,
4864 Handled_Statement_Sequence
=> HSS
));
4867 -- If the result type contains tasks, we call Move_Activation_Chain.
4868 -- Later, the cleanup code will call Complete_Master, which will
4869 -- terminate any unactivated tasks belonging to the return statement
4870 -- master. But Move_Activation_Chain updates their master to be that
4871 -- of the caller, so they will not be terminated unless the return
4872 -- statement completes unsuccessfully due to exception, abort, goto,
4873 -- or exit. As a formality, we test whether the function requires the
4874 -- result to be built in place, though that's necessarily true for
4875 -- the case of result types with task parts.
4877 if Is_BIP_Func
and then Has_Task
(Ret_Typ
) then
4879 -- The return expression is an aggregate for a complex type which
4880 -- contains tasks. This particular case is left unexpanded since
4881 -- the regular expansion would insert all temporaries and
4882 -- initialization code in the wrong block.
4884 if Nkind
(Exp
) = N_Aggregate
then
4885 Expand_N_Aggregate
(Exp
);
4888 -- Do not move the activation chain if the return object does not
4891 if Has_Task
(Etype
(Ret_Obj_Id
)) then
4892 Append_To
(Stmts
, Move_Activation_Chain
(Func_Id
));
4896 -- Update the state of the function right before the object is
4899 if Is_BIP_Func
and then Needs_Finalization
(Etype
(Ret_Obj_Id
)) then
4901 Flag_Id
: constant Entity_Id
:=
4902 Status_Flag_Or_Transient_Decl
(Ret_Obj_Id
);
4909 Make_Assignment_Statement
(Loc
,
4910 Name
=> New_Occurrence_Of
(Flag_Id
, Loc
),
4911 Expression
=> New_Occurrence_Of
(Standard_True
, Loc
)));
4915 -- Build a simple_return_statement that returns the return object
4918 Make_Simple_Return_Statement
(Loc
,
4919 Expression
=> New_Occurrence_Of
(Ret_Obj_Id
, Loc
));
4920 Append_To
(Stmts
, Return_Stmt
);
4922 HSS
:= Make_Handled_Sequence_Of_Statements
(Loc
, Stmts
);
4925 -- Case where we build a return statement block
4927 if Present
(HSS
) then
4929 Make_Block_Statement
(Loc
,
4930 Declarations
=> Return_Object_Declarations
(N
),
4931 Handled_Statement_Sequence
=> HSS
);
4933 -- We set the entity of the new block statement to be that of the
4934 -- return statement. This is necessary so that various fields, such
4935 -- as Finalization_Chain_Entity carry over from the return statement
4936 -- to the block. Note that this block is unusual, in that its entity
4937 -- is an E_Return_Statement rather than an E_Block.
4940 (Result
, New_Occurrence_Of
(Return_Statement_Entity
(N
), Loc
));
4942 -- If the object decl was already rewritten as a renaming, then we
4943 -- don't want to do the object allocation and transformation of
4944 -- the return object declaration to a renaming. This case occurs
4945 -- when the return object is initialized by a call to another
4946 -- build-in-place function, and that function is responsible for
4947 -- the allocation of the return object.
4950 and then Nkind
(Ret_Obj_Decl
) = N_Object_Renaming_Declaration
4953 (Nkind
(Original_Node
(Ret_Obj_Decl
)) = N_Object_Declaration
4956 -- It is a regular BIP object declaration
4958 (Is_Build_In_Place_Function_Call
4959 (Expression
(Original_Node
(Ret_Obj_Decl
)))
4961 -- It is a BIP object declaration that displaces the pointer
4962 -- to the object to reference a convered interface type.
4965 Present
(Unqual_BIP_Iface_Function_Call
4966 (Expression
(Original_Node
(Ret_Obj_Decl
))))));
4968 -- Return the build-in-place result by reference
4970 Set_By_Ref
(Return_Stmt
);
4972 elsif Is_BIP_Func
then
4974 -- Locate the implicit access parameter associated with the
4975 -- caller-supplied return object and convert the return
4976 -- statement's return object declaration to a renaming of a
4977 -- dereference of the access parameter. If the return object's
4978 -- declaration includes an expression that has not already been
4979 -- expanded as separate assignments, then add an assignment
4980 -- statement to ensure the return object gets initialized.
4983 -- Result : T [:= <expression>];
4990 -- Result : T renames FuncRA.all;
4991 -- [Result := <expression;]
4996 Ret_Obj_Expr
: constant Node_Id
:= Expression
(Ret_Obj_Decl
);
4997 Ret_Obj_Typ
: constant Entity_Id
:= Etype
(Ret_Obj_Id
);
4999 Init_Assignment
: Node_Id
:= Empty
;
5000 Obj_Acc_Formal
: Entity_Id
;
5001 Obj_Acc_Deref
: Node_Id
;
5002 Obj_Alloc_Formal
: Entity_Id
;
5005 -- Build-in-place results must be returned by reference
5007 Set_By_Ref
(Return_Stmt
);
5009 -- Retrieve the implicit access parameter passed by the caller
5012 Build_In_Place_Formal
(Func_Id
, BIP_Object_Access
);
5014 -- If the return object's declaration includes an expression
5015 -- and the declaration isn't marked as No_Initialization, then
5016 -- we need to generate an assignment to the object and insert
5017 -- it after the declaration before rewriting it as a renaming
5018 -- (otherwise we'll lose the initialization). The case where
5019 -- the result type is an interface (or class-wide interface)
5020 -- is also excluded because the context of the function call
5021 -- must be unconstrained, so the initialization will always
5022 -- be done as part of an allocator evaluation (storage pool
5023 -- or secondary stack), never to a constrained target object
5024 -- passed in by the caller. Besides the assignment being
5025 -- unneeded in this case, it avoids problems with trying to
5026 -- generate a dispatching assignment when the return expression
5027 -- is a nonlimited descendant of a limited interface (the
5028 -- interface has no assignment operation).
5030 if Present
(Ret_Obj_Expr
)
5031 and then not No_Initialization
(Ret_Obj_Decl
)
5032 and then not Is_Interface
(Ret_Obj_Typ
)
5035 Make_Assignment_Statement
(Loc
,
5036 Name
=> New_Occurrence_Of
(Ret_Obj_Id
, Loc
),
5039 (Source
=> Ret_Obj_Expr
,
5040 Scopes_In_EWA_OK
=> True));
5042 Set_Etype
(Name
(Init_Assignment
), Etype
(Ret_Obj_Id
));
5043 Set_Assignment_OK
(Name
(Init_Assignment
));
5044 Set_No_Ctrl_Actions
(Init_Assignment
);
5046 Set_Parent
(Name
(Init_Assignment
), Init_Assignment
);
5047 Set_Parent
(Expression
(Init_Assignment
), Init_Assignment
);
5049 Set_Expression
(Ret_Obj_Decl
, Empty
);
5051 if Is_Class_Wide_Type
(Etype
(Ret_Obj_Id
))
5052 and then not Is_Class_Wide_Type
5053 (Etype
(Expression
(Init_Assignment
)))
5055 Rewrite
(Expression
(Init_Assignment
),
5056 Make_Type_Conversion
(Loc
,
5058 New_Occurrence_Of
(Etype
(Ret_Obj_Id
), Loc
),
5060 Relocate_Node
(Expression
(Init_Assignment
))));
5063 -- In the case of functions where the calling context can
5064 -- determine the form of allocation needed, initialization
5065 -- is done with each part of the if statement that handles
5066 -- the different forms of allocation (this is true for
5067 -- unconstrained, tagged, and controlled result subtypes).
5069 if not Needs_BIP_Alloc_Form
(Func_Id
) then
5070 Insert_After
(Ret_Obj_Decl
, Init_Assignment
);
5074 -- When the function's subtype is unconstrained, a run-time
5075 -- test is needed to determine the form of allocation to use
5076 -- for the return object. The function has an implicit formal
5077 -- parameter indicating this. If the BIP_Alloc_Form formal has
5078 -- the value one, then the caller has passed access to an
5079 -- existing object for use as the return object. If the value
5080 -- is two, then the return object must be allocated on the
5081 -- secondary stack. Otherwise, the object must be allocated in
5082 -- a storage pool. We generate an if statement to test the
5083 -- implicit allocation formal and initialize a local access
5084 -- value appropriately, creating allocators in the secondary
5085 -- stack and global heap cases. The special formal also exists
5086 -- and must be tested when the function has a tagged result,
5087 -- even when the result subtype is constrained, because in
5088 -- general such functions can be called in dispatching contexts
5089 -- and must be handled similarly to functions with a class-wide
5092 if Needs_BIP_Alloc_Form
(Func_Id
) then
5094 Build_In_Place_Formal
(Func_Id
, BIP_Alloc_Form
);
5097 Pool_Id
: constant Entity_Id
:=
5098 Make_Temporary
(Loc
, 'P');
5099 Alloc_Obj_Id
: Entity_Id
;
5100 Alloc_Obj_Decl
: Node_Id
;
5101 Alloc_If_Stmt
: Node_Id
;
5102 Guard_Except
: Node_Id
;
5103 Heap_Allocator
: Node_Id
;
5104 Pool_Decl
: Node_Id
;
5105 Pool_Allocator
: Node_Id
;
5106 Ptr_Type_Decl
: Node_Id
;
5107 Ref_Type
: Entity_Id
;
5108 SS_Allocator
: Node_Id
;
5111 -- Reuse the itype created for the function's implicit
5112 -- access formal. This avoids the need to create a new
5113 -- access type here, plus it allows assigning the access
5114 -- formal directly without applying a conversion.
5116 -- Ref_Type := Etype (Object_Access);
5118 -- Create an access type designating the function's
5121 Ref_Type
:= Make_Temporary
(Loc
, 'A');
5124 Make_Full_Type_Declaration
(Loc
,
5125 Defining_Identifier
=> Ref_Type
,
5127 Make_Access_To_Object_Definition
(Loc
,
5128 All_Present
=> True,
5129 Subtype_Indication
=>
5130 New_Occurrence_Of
(Ret_Obj_Typ
, Loc
)));
5132 Insert_Before
(Ret_Obj_Decl
, Ptr_Type_Decl
);
5134 -- Create an access object that will be initialized to an
5135 -- access value denoting the return object, either coming
5136 -- from an implicit access value passed in by the caller
5137 -- or from the result of an allocator.
5139 Alloc_Obj_Id
:= Make_Temporary
(Loc
, 'R');
5140 Set_Etype
(Alloc_Obj_Id
, Ref_Type
);
5143 Make_Object_Declaration
(Loc
,
5144 Defining_Identifier
=> Alloc_Obj_Id
,
5145 Object_Definition
=>
5146 New_Occurrence_Of
(Ref_Type
, Loc
));
5148 Insert_Before
(Ret_Obj_Decl
, Alloc_Obj_Decl
);
5150 -- Create allocators for both the secondary stack and
5151 -- global heap. If there's an initialization expression,
5152 -- then create these as initialized allocators.
5154 if Present
(Ret_Obj_Expr
)
5155 and then not No_Initialization
(Ret_Obj_Decl
)
5157 -- Always use the type of the expression for the
5158 -- qualified expression, rather than the result type.
5159 -- In general we cannot always use the result type
5160 -- for the allocator, because the expression might be
5161 -- of a specific type, such as in the case of an
5162 -- aggregate or even a nonlimited object when the
5163 -- result type is a limited class-wide interface type.
5166 Make_Allocator
(Loc
,
5168 Make_Qualified_Expression
(Loc
,
5171 (Etype
(Ret_Obj_Expr
), Loc
),
5174 (Source
=> Ret_Obj_Expr
,
5175 Scopes_In_EWA_OK
=> True)));
5178 -- If the function returns a class-wide type we cannot
5179 -- use the return type for the allocator. Instead we
5180 -- use the type of the expression, which must be an
5181 -- aggregate of a definite type.
5183 if Is_Class_Wide_Type
(Ret_Obj_Typ
) then
5185 Make_Allocator
(Loc
,
5188 (Etype
(Ret_Obj_Expr
), Loc
));
5191 Make_Allocator
(Loc
,
5193 New_Occurrence_Of
(Ret_Obj_Typ
, Loc
));
5196 -- If the object requires default initialization then
5197 -- that will happen later following the elaboration of
5198 -- the object renaming. If we don't turn it off here
5199 -- then the object will be default initialized twice.
5201 Set_No_Initialization
(Heap_Allocator
);
5204 -- Set the flag indicating that the allocator came from
5205 -- a build-in-place return statement, so we can avoid
5206 -- adjusting the allocated object. Note that this flag
5207 -- will be inherited by the copies made below.
5209 Set_Alloc_For_BIP_Return
(Heap_Allocator
);
5211 -- The Pool_Allocator is just like the Heap_Allocator,
5212 -- except we set Storage_Pool and Procedure_To_Call so
5213 -- it will use the user-defined storage pool.
5217 (Source
=> Heap_Allocator
,
5218 Scopes_In_EWA_OK
=> True);
5220 pragma Assert
(Alloc_For_BIP_Return
(Pool_Allocator
));
5222 -- Do not generate the renaming of the build-in-place
5223 -- pool parameter on ZFP because the parameter is not
5224 -- created in the first place.
5226 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
5228 Make_Object_Renaming_Declaration
(Loc
,
5229 Defining_Identifier
=> Pool_Id
,
5232 (RTE
(RE_Root_Storage_Pool
), Loc
),
5234 Make_Explicit_Dereference
(Loc
,
5236 (Build_In_Place_Formal
5237 (Func_Id
, BIP_Storage_Pool
), Loc
)));
5238 Set_Storage_Pool
(Pool_Allocator
, Pool_Id
);
5239 Set_Procedure_To_Call
5240 (Pool_Allocator
, RTE
(RE_Allocate_Any
));
5242 Pool_Decl
:= Make_Null_Statement
(Loc
);
5245 -- If the No_Allocators restriction is active, then only
5246 -- an allocator for secondary stack allocation is needed.
5247 -- It's OK for such allocators to have Comes_From_Source
5248 -- set to False, because gigi knows not to flag them as
5249 -- being a violation of No_Implicit_Heap_Allocations.
5251 if Restriction_Active
(No_Allocators
) then
5252 SS_Allocator
:= Heap_Allocator
;
5253 Heap_Allocator
:= Make_Null
(Loc
);
5254 Pool_Allocator
:= Make_Null
(Loc
);
5256 -- Otherwise the heap and pool allocators may be needed,
5257 -- so we make another allocator for secondary stack
5263 (Source
=> Heap_Allocator
,
5264 Scopes_In_EWA_OK
=> True);
5266 pragma Assert
(Alloc_For_BIP_Return
(SS_Allocator
));
5268 -- The heap and pool allocators are marked as
5269 -- Comes_From_Source since they correspond to an
5270 -- explicit user-written allocator (that is, it will
5271 -- only be executed on behalf of callers that call the
5272 -- function as initialization for such an allocator).
5273 -- Prevents errors when No_Implicit_Heap_Allocations
5276 Set_Comes_From_Source
(Heap_Allocator
, True);
5277 Set_Comes_From_Source
(Pool_Allocator
, True);
5280 -- The allocator is returned on the secondary stack
5282 Check_Restriction
(No_Secondary_Stack
, N
);
5283 Set_Storage_Pool
(SS_Allocator
, RTE
(RE_SS_Pool
));
5284 Set_Procedure_To_Call
5285 (SS_Allocator
, RTE
(RE_SS_Allocate
));
5287 -- The allocator is returned on the secondary stack,
5288 -- so indicate that the function return, as well as
5289 -- all blocks that encloses the allocator, must not
5290 -- release it. The flags must be set now because
5291 -- the decision to use the secondary stack is done
5292 -- very late in the course of expanding the return
5293 -- statement, past the point where these flags are
5296 Set_Uses_Sec_Stack
(Func_Id
);
5297 Set_Uses_Sec_Stack
(Return_Statement_Entity
(N
));
5298 Set_Sec_Stack_Needed_For_Return
5299 (Return_Statement_Entity
(N
));
5300 Set_Enclosing_Sec_Stack_Return
(N
);
5302 -- Guard against poor expansion on the caller side by
5303 -- using a raise statement to catch out-of-range values
5304 -- of formal parameter BIP_Alloc_Form.
5306 if Exceptions_OK
then
5308 Make_Raise_Program_Error
(Loc
,
5309 Reason
=> PE_Build_In_Place_Mismatch
);
5311 Guard_Except
:= Make_Null_Statement
(Loc
);
5314 -- Create an if statement to test the BIP_Alloc_Form
5315 -- formal and initialize the access object to either the
5316 -- BIP_Object_Access formal (BIP_Alloc_Form =
5317 -- Caller_Allocation), the result of allocating the
5318 -- object in the secondary stack (BIP_Alloc_Form =
5319 -- Secondary_Stack), or else an allocator to create the
5320 -- return object in the heap or user-defined pool
5321 -- (BIP_Alloc_Form = Global_Heap or User_Storage_Pool).
5323 -- ??? An unchecked type conversion must be made in the
5324 -- case of assigning the access object formal to the
5325 -- local access object, because a normal conversion would
5326 -- be illegal in some cases (such as converting access-
5327 -- to-unconstrained to access-to-constrained), but the
5328 -- the unchecked conversion will presumably fail to work
5329 -- right in just such cases. It's not clear at all how to
5333 Make_If_Statement
(Loc
,
5337 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5339 Make_Integer_Literal
(Loc
,
5340 UI_From_Int
(BIP_Allocation_Form
'Pos
5341 (Caller_Allocation
)))),
5343 Then_Statements
=> New_List
(
5344 Make_Assignment_Statement
(Loc
,
5346 New_Occurrence_Of
(Alloc_Obj_Id
, Loc
),
5348 Make_Unchecked_Type_Conversion
(Loc
,
5350 New_Occurrence_Of
(Ref_Type
, Loc
),
5352 New_Occurrence_Of
(Obj_Acc_Formal
, Loc
)))),
5354 Elsif_Parts
=> New_List
(
5355 Make_Elsif_Part
(Loc
,
5359 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5361 Make_Integer_Literal
(Loc
,
5362 UI_From_Int
(BIP_Allocation_Form
'Pos
5363 (Secondary_Stack
)))),
5365 Then_Statements
=> New_List
(
5366 Make_Assignment_Statement
(Loc
,
5368 New_Occurrence_Of
(Alloc_Obj_Id
, Loc
),
5369 Expression
=> SS_Allocator
))),
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
5381 Then_Statements
=> New_List
(
5382 Build_Heap_Or_Pool_Allocator
5383 (Temp_Id
=> Alloc_Obj_Id
,
5384 Temp_Typ
=> Ref_Type
,
5386 Ret_Typ
=> Ret_Obj_Typ
,
5387 Alloc_Expr
=> Heap_Allocator
))),
5389 -- ???If all is well, we can put the following
5390 -- 'elsif' in the 'else', but this is a useful
5391 -- self-check in case caller and callee don't agree
5392 -- on whether BIPAlloc and so on should be passed.
5394 Make_Elsif_Part
(Loc
,
5398 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5400 Make_Integer_Literal
(Loc
,
5401 UI_From_Int
(BIP_Allocation_Form
'Pos
5402 (User_Storage_Pool
)))),
5404 Then_Statements
=> New_List
(
5406 Build_Heap_Or_Pool_Allocator
5407 (Temp_Id
=> Alloc_Obj_Id
,
5408 Temp_Typ
=> Ref_Type
,
5410 Ret_Typ
=> Ret_Obj_Typ
,
5411 Alloc_Expr
=> Pool_Allocator
)))),
5413 -- Raise Program_Error if it's none of the above;
5414 -- this is a compiler bug.
5416 Else_Statements
=> New_List
(Guard_Except
));
5418 -- If a separate initialization assignment was created
5419 -- earlier, append that following the assignment of the
5420 -- implicit access formal to the access object, to ensure
5421 -- that the return object is initialized in that case. In
5422 -- this situation, the target of the assignment must be
5423 -- rewritten to denote a dereference of the access to the
5424 -- return object passed in by the caller.
5426 if Present
(Init_Assignment
) then
5427 Rewrite
(Name
(Init_Assignment
),
5428 Make_Explicit_Dereference
(Loc
,
5429 Prefix
=> New_Occurrence_Of
(Alloc_Obj_Id
, Loc
)));
5432 (Original_Node
(Name
(Init_Assignment
))));
5433 Set_Assignment_OK
(Name
(Init_Assignment
));
5435 Set_Etype
(Name
(Init_Assignment
), Etype
(Ret_Obj_Id
));
5438 (Then_Statements
(Alloc_If_Stmt
), Init_Assignment
);
5441 Insert_Before
(Ret_Obj_Decl
, Alloc_If_Stmt
);
5443 -- Remember the local access object for use in the
5444 -- dereference of the renaming created below.
5446 Obj_Acc_Formal
:= Alloc_Obj_Id
;
5450 -- Replace the return object declaration with a renaming of a
5451 -- dereference of the access value designating the return
5455 Make_Explicit_Dereference
(Loc
,
5456 Prefix
=> New_Occurrence_Of
(Obj_Acc_Formal
, Loc
));
5458 Rewrite
(Ret_Obj_Decl
,
5459 Make_Object_Renaming_Declaration
(Loc
,
5460 Defining_Identifier
=> Ret_Obj_Id
,
5461 Access_Definition
=> Empty
,
5462 Subtype_Mark
=> New_Occurrence_Of
(Ret_Obj_Typ
, Loc
),
5463 Name
=> Obj_Acc_Deref
));
5465 Set_Renamed_Object
(Ret_Obj_Id
, Obj_Acc_Deref
);
5469 -- Case where we do not build a block
5472 -- We're about to drop Return_Object_Declarations on the floor, so
5473 -- we need to insert it, in case it got expanded into useful code.
5474 -- Remove side effects from expression, which may be duplicated in
5475 -- subsequent checks (see Expand_Simple_Function_Return).
5477 Insert_List_Before
(N
, Return_Object_Declarations
(N
));
5478 Remove_Side_Effects
(Exp
);
5480 -- Build simple_return_statement that returns the expression directly
5482 Return_Stmt
:= Make_Simple_Return_Statement
(Loc
, Expression
=> Exp
);
5483 Result
:= Return_Stmt
;
5486 -- Set the flag to prevent infinite recursion
5488 Set_Comes_From_Extended_Return_Statement
(Return_Stmt
);
5490 Rewrite
(N
, Result
);
5491 Analyze
(N
, Suppress
=> All_Checks
);
5492 end Expand_N_Extended_Return_Statement
;
5494 ----------------------------
5495 -- Expand_N_Function_Call --
5496 ----------------------------
5498 procedure Expand_N_Function_Call
(N
: Node_Id
) is
5501 end Expand_N_Function_Call
;
5503 ---------------------------------------
5504 -- Expand_N_Procedure_Call_Statement --
5505 ---------------------------------------
5507 procedure Expand_N_Procedure_Call_Statement
(N
: Node_Id
) is
5510 end Expand_N_Procedure_Call_Statement
;
5512 --------------------------------------
5513 -- Expand_N_Simple_Return_Statement --
5514 --------------------------------------
5516 procedure Expand_N_Simple_Return_Statement
(N
: Node_Id
) is
5518 -- Defend against previous errors (i.e. the return statement calls a
5519 -- function that is not available in configurable runtime).
5521 if Present
(Expression
(N
))
5522 and then Nkind
(Expression
(N
)) = N_Empty
5524 Check_Error_Detected
;
5528 -- Distinguish the function and non-function cases:
5530 case Ekind
(Return_Applies_To
(Return_Statement_Entity
(N
))) is
5532 | E_Generic_Function
5534 Expand_Simple_Function_Return
(N
);
5538 | E_Generic_Procedure
5540 | E_Return_Statement
5542 Expand_Non_Function_Return
(N
);
5545 raise Program_Error
;
5549 when RE_Not_Available
=>
5551 end Expand_N_Simple_Return_Statement
;
5553 ------------------------------
5554 -- Expand_N_Subprogram_Body --
5555 ------------------------------
5557 -- Add poll call if ATC polling is enabled, unless the body will be inlined
5560 -- Add dummy push/pop label nodes at start and end to clear any local
5561 -- exception indications if local-exception-to-goto optimization is active.
5563 -- Add return statement if last statement in body is not a return statement
5564 -- (this makes things easier on Gigi which does not want to have to handle
5565 -- a missing return).
5567 -- Add call to Activate_Tasks if body is a task activator
5569 -- Deal with possible detection of infinite recursion
5571 -- Eliminate body completely if convention stubbed
5573 -- Encode entity names within body, since we will not need to reference
5574 -- these entities any longer in the front end.
5576 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
5578 -- Reset Pure indication if any parameter has root type System.Address
5579 -- or has any parameters of limited types, where limited means that the
5580 -- run-time view is limited (i.e. the full type is limited).
5584 procedure Expand_N_Subprogram_Body
(N
: Node_Id
) is
5585 Body_Id
: constant Entity_Id
:= Defining_Entity
(N
);
5586 HSS
: constant Node_Id
:= Handled_Statement_Sequence
(N
);
5587 Loc
: constant Source_Ptr
:= Sloc
(N
);
5589 procedure Add_Return
(Spec_Id
: Entity_Id
; Stmts
: List_Id
);
5590 -- Append a return statement to the statement sequence Stmts if the last
5591 -- statement is not already a return or a goto statement. Note that the
5592 -- latter test is not critical, it does not matter if we add a few extra
5593 -- returns, since they get eliminated anyway later on. Spec_Id denotes
5594 -- the corresponding spec of the subprogram body.
5600 procedure Add_Return
(Spec_Id
: Entity_Id
; Stmts
: List_Id
) is
5601 Last_Stmt
: Node_Id
;
5606 -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
5607 -- not relevant in this context since they are not executable.
5609 Last_Stmt
:= Last
(Stmts
);
5610 while Nkind
(Last_Stmt
) in N_Pop_xxx_Label
loop
5614 -- Now insert return unless last statement is a transfer
5616 if not Is_Transfer
(Last_Stmt
) then
5618 -- The source location for the return is the end label of the
5619 -- procedure if present. Otherwise use the sloc of the last
5620 -- statement in the list. If the list comes from a generated
5621 -- exception handler and we are not debugging generated code,
5622 -- all the statements within the handler are made invisible
5625 if Nkind
(Parent
(Stmts
)) = N_Exception_Handler
5626 and then not Comes_From_Source
(Parent
(Stmts
))
5628 Loc
:= Sloc
(Last_Stmt
);
5629 elsif Present
(End_Label
(HSS
)) then
5630 Loc
:= Sloc
(End_Label
(HSS
));
5632 Loc
:= Sloc
(Last_Stmt
);
5635 -- Append return statement, and set analyzed manually. We can't
5636 -- call Analyze on this return since the scope is wrong.
5638 -- Note: it almost works to push the scope and then do the Analyze
5639 -- call, but something goes wrong in some weird cases and it is
5640 -- not worth worrying about ???
5642 Stmt
:= Make_Simple_Return_Statement
(Loc
);
5644 -- The return statement is handled properly, and the call to the
5645 -- postcondition, inserted below, does not require information
5646 -- from the body either. However, that call is analyzed in the
5647 -- enclosing scope, and an elaboration check might improperly be
5648 -- added to it. A guard in Sem_Elab is needed to prevent that
5649 -- spurious check, see Check_Elab_Call.
5651 Append_To
(Stmts
, Stmt
);
5652 Set_Analyzed
(Stmt
);
5654 -- Call the _Postconditions procedure if the related subprogram
5655 -- has contract assertions that need to be verified on exit.
5657 if Ekind
(Spec_Id
) = E_Procedure
5658 and then Present
(Postconditions_Proc
(Spec_Id
))
5660 Insert_Action
(Stmt
,
5661 Make_Procedure_Call_Statement
(Loc
,
5663 New_Occurrence_Of
(Postconditions_Proc
(Spec_Id
), Loc
)));
5672 Spec_Id
: Entity_Id
;
5674 -- Start of processing for Expand_N_Subprogram_Body
5677 if Present
(Corresponding_Spec
(N
)) then
5678 Spec_Id
:= Corresponding_Spec
(N
);
5683 -- If this is a Pure function which has any parameters whose root type
5684 -- is System.Address, reset the Pure indication.
5685 -- This check is also performed when the subprogram is frozen, but we
5686 -- repeat it on the body so that the indication is consistent, and so
5687 -- it applies as well to bodies without separate specifications.
5689 if Is_Pure
(Spec_Id
)
5690 and then Is_Subprogram
(Spec_Id
)
5691 and then not Has_Pragma_Pure_Function
(Spec_Id
)
5693 Check_Function_With_Address_Parameter
(Spec_Id
);
5695 if Spec_Id
/= Body_Id
then
5696 Set_Is_Pure
(Body_Id
, Is_Pure
(Spec_Id
));
5700 -- Set L to either the list of declarations if present, or to the list
5701 -- of statements if no declarations are present. This is used to insert
5702 -- new stuff at the start.
5704 if Is_Non_Empty_List
(Declarations
(N
)) then
5705 L
:= Declarations
(N
);
5707 L
:= Statements
(HSS
);
5710 -- If local-exception-to-goto optimization active, insert dummy push
5711 -- statements at start, and dummy pop statements at end, but inhibit
5712 -- this if we have No_Exception_Handlers, since they are useless and
5713 -- interfere with analysis, e.g. by CodePeer. We also don't need these
5714 -- if we're unnesting subprograms because the only purpose of these
5715 -- nodes is to ensure we don't set a label in one subprogram and branch
5716 -- to it in another.
5718 if (Debug_Flag_Dot_G
5719 or else Restriction_Active
(No_Exception_Propagation
))
5720 and then not Restriction_Active
(No_Exception_Handlers
)
5721 and then not CodePeer_Mode
5722 and then not Unnest_Subprogram_Mode
5723 and then Is_Non_Empty_List
(L
)
5726 FS
: constant Node_Id
:= First
(L
);
5727 FL
: constant Source_Ptr
:= Sloc
(FS
);
5732 -- LS points to either last statement, if statements are present
5733 -- or to the last declaration if there are no statements present.
5734 -- It is the node after which the pop's are generated.
5736 if Is_Non_Empty_List
(Statements
(HSS
)) then
5737 LS
:= Last
(Statements
(HSS
));
5744 Insert_List_Before_And_Analyze
(FS
, New_List
(
5745 Make_Push_Constraint_Error_Label
(FL
),
5746 Make_Push_Program_Error_Label
(FL
),
5747 Make_Push_Storage_Error_Label
(FL
)));
5749 Insert_List_After_And_Analyze
(LS
, New_List
(
5750 Make_Pop_Constraint_Error_Label
(LL
),
5751 Make_Pop_Program_Error_Label
(LL
),
5752 Make_Pop_Storage_Error_Label
(LL
)));
5756 -- Need poll on entry to subprogram if polling enabled. We only do this
5757 -- for non-empty subprograms, since it does not seem necessary to poll
5758 -- for a dummy null subprogram.
5760 if Is_Non_Empty_List
(L
) then
5762 -- Do not add a polling call if the subprogram is to be inlined by
5763 -- the back-end, to avoid repeated calls with multiple inlinings.
5765 if Is_Inlined
(Spec_Id
)
5766 and then Front_End_Inlining
5767 and then Optimization_Level
> 1
5771 Generate_Poll_Call
(First
(L
));
5775 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
5777 if Init_Or_Norm_Scalars
and then Is_Subprogram
(Spec_Id
) then
5783 -- Loop through formals
5785 F
:= First_Formal
(Spec_Id
);
5786 while Present
(F
) loop
5787 if Is_Scalar_Type
(Etype
(F
))
5788 and then Ekind
(F
) = E_Out_Parameter
5790 Check_Restriction
(No_Default_Initialization
, F
);
5792 -- Insert the initialization. We turn off validity checks
5793 -- for this assignment, since we do not want any check on
5794 -- the initial value itself (which may well be invalid).
5795 -- Predicate checks are disabled as well (RM 6.4.1 (13/3))
5798 Make_Assignment_Statement
(Loc
,
5799 Name
=> New_Occurrence_Of
(F
, Loc
),
5800 Expression
=> Get_Simple_Init_Val
(Etype
(F
), N
));
5801 Set_Suppress_Assignment_Checks
(A
);
5803 Insert_Before_And_Analyze
(First
(L
),
5804 A
, Suppress
=> Validity_Check
);
5812 -- Clear out statement list for stubbed procedure
5814 if Present
(Corresponding_Spec
(N
)) then
5815 Set_Elaboration_Flag
(N
, Spec_Id
);
5817 if Convention
(Spec_Id
) = Convention_Stubbed
5818 or else Is_Eliminated
(Spec_Id
)
5820 Set_Declarations
(N
, Empty_List
);
5821 Set_Handled_Statement_Sequence
(N
,
5822 Make_Handled_Sequence_Of_Statements
(Loc
,
5823 Statements
=> New_List
(Make_Null_Statement
(Loc
))));
5829 -- Create a set of discriminals for the next protected subprogram body
5831 if Is_List_Member
(N
)
5832 and then Present
(Parent
(List_Containing
(N
)))
5833 and then Nkind
(Parent
(List_Containing
(N
))) = N_Protected_Body
5834 and then Present
(Next_Protected_Operation
(N
))
5836 Set_Discriminals
(Parent
(Base_Type
(Scope
(Spec_Id
))));
5839 -- Returns_By_Ref flag is normally set when the subprogram is frozen but
5840 -- subprograms with no specs are not frozen.
5843 Typ
: constant Entity_Id
:= Etype
(Spec_Id
);
5844 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
5847 if Is_Limited_View
(Typ
) then
5848 Set_Returns_By_Ref
(Spec_Id
);
5850 elsif Present
(Utyp
) and then CW_Or_Has_Controlled_Part
(Utyp
) then
5851 Set_Returns_By_Ref
(Spec_Id
);
5855 -- For a procedure, we add a return for all possible syntactic ends of
5858 if Ekind_In
(Spec_Id
, E_Procedure
, E_Generic_Procedure
) then
5859 Add_Return
(Spec_Id
, Statements
(HSS
));
5861 if Present
(Exception_Handlers
(HSS
)) then
5862 Except_H
:= First_Non_Pragma
(Exception_Handlers
(HSS
));
5863 while Present
(Except_H
) loop
5864 Add_Return
(Spec_Id
, Statements
(Except_H
));
5865 Next_Non_Pragma
(Except_H
);
5869 -- For a function, we must deal with the case where there is at least
5870 -- one missing return. What we do is to wrap the entire body of the
5871 -- function in a block:
5884 -- raise Program_Error;
5887 -- This approach is necessary because the raise must be signalled to the
5888 -- caller, not handled by any local handler (RM 6.4(11)).
5890 -- Note: we do not need to analyze the constructed sequence here, since
5891 -- it has no handler, and an attempt to analyze the handled statement
5892 -- sequence twice is risky in various ways (e.g. the issue of expanding
5893 -- cleanup actions twice).
5895 elsif Has_Missing_Return
(Spec_Id
) then
5897 Hloc
: constant Source_Ptr
:= Sloc
(HSS
);
5898 Blok
: constant Node_Id
:=
5899 Make_Block_Statement
(Hloc
,
5900 Handled_Statement_Sequence
=> HSS
);
5901 Rais
: constant Node_Id
:=
5902 Make_Raise_Program_Error
(Hloc
,
5903 Reason
=> PE_Missing_Return
);
5906 Set_Handled_Statement_Sequence
(N
,
5907 Make_Handled_Sequence_Of_Statements
(Hloc
,
5908 Statements
=> New_List
(Blok
, Rais
)));
5910 Push_Scope
(Spec_Id
);
5917 -- If subprogram contains a parameterless recursive call, then we may
5918 -- have an infinite recursion, so see if we can generate code to check
5919 -- for this possibility if storage checks are not suppressed.
5921 if Ekind
(Spec_Id
) = E_Procedure
5922 and then Has_Recursive_Call
(Spec_Id
)
5923 and then not Storage_Checks_Suppressed
(Spec_Id
)
5925 Detect_Infinite_Recursion
(N
, Spec_Id
);
5928 -- Set to encode entity names in package body before gigi is called
5930 Qualify_Entity_Names
(N
);
5932 -- If the body belongs to a nonabstract library-level source primitive
5933 -- of a tagged type, install an elaboration check which ensures that a
5934 -- dispatching call targeting the primitive will not execute the body
5935 -- without it being previously elaborated.
5937 Install_Primitive_Elaboration_Check
(N
);
5938 end Expand_N_Subprogram_Body
;
5940 -----------------------------------
5941 -- Expand_N_Subprogram_Body_Stub --
5942 -----------------------------------
5944 procedure Expand_N_Subprogram_Body_Stub
(N
: Node_Id
) is
5948 if Present
(Corresponding_Body
(N
)) then
5949 Bod
:= Unit_Declaration_Node
(Corresponding_Body
(N
));
5951 -- The body may have been expanded already when it is analyzed
5952 -- through the subunit node. Do no expand again: it interferes
5953 -- with the construction of unnesting tables when generating C.
5955 if not Analyzed
(Bod
) then
5956 Expand_N_Subprogram_Body
(Bod
);
5959 -- Add full qualification to entities that may be created late
5960 -- during unnesting.
5962 Qualify_Entity_Names
(N
);
5964 end Expand_N_Subprogram_Body_Stub
;
5966 -------------------------------------
5967 -- Expand_N_Subprogram_Declaration --
5968 -------------------------------------
5970 -- If the declaration appears within a protected body, it is a private
5971 -- operation of the protected type. We must create the corresponding
5972 -- protected subprogram an associated formals. For a normal protected
5973 -- operation, this is done when expanding the protected type declaration.
5975 -- If the declaration is for a null procedure, emit null body
5977 procedure Expand_N_Subprogram_Declaration
(N
: Node_Id
) is
5978 Loc
: constant Source_Ptr
:= Sloc
(N
);
5979 Subp
: constant Entity_Id
:= Defining_Entity
(N
);
5983 Scop
: constant Entity_Id
:= Scope
(Subp
);
5985 Prot_Decl
: Node_Id
;
5986 Prot_Id
: Entity_Id
;
5988 -- Start of processing for Expand_N_Subprogram_Declaration
5991 -- In SPARK, subprogram declarations are only allowed in package
5994 if Nkind
(Parent
(N
)) /= N_Package_Specification
then
5995 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
5996 Check_SPARK_05_Restriction
5997 ("subprogram declaration is not a library item", N
);
5999 elsif Present
(Next
(N
))
6000 and then Nkind
(Next
(N
)) = N_Pragma
6001 and then Get_Pragma_Id
(Next
(N
)) = Pragma_Import
6003 -- In SPARK, subprogram declarations are also permitted in
6004 -- declarative parts when immediately followed by a corresponding
6005 -- pragma Import. We only check here that there is some pragma
6010 Check_SPARK_05_Restriction
6011 ("subprogram declaration is not allowed here", N
);
6015 -- Deal with case of protected subprogram. Do not generate protected
6016 -- operation if operation is flagged as eliminated.
6018 if Is_List_Member
(N
)
6019 and then Present
(Parent
(List_Containing
(N
)))
6020 and then Nkind
(Parent
(List_Containing
(N
))) = N_Protected_Body
6021 and then Is_Protected_Type
(Scop
)
6023 if No
(Protected_Body_Subprogram
(Subp
))
6024 and then not Is_Eliminated
(Subp
)
6027 Make_Subprogram_Declaration
(Loc
,
6029 Build_Protected_Sub_Specification
6030 (N
, Scop
, Unprotected_Mode
));
6032 -- The protected subprogram is declared outside of the protected
6033 -- body. Given that the body has frozen all entities so far, we
6034 -- analyze the subprogram and perform freezing actions explicitly.
6035 -- including the generation of an explicit freeze node, to ensure
6036 -- that gigi has the proper order of elaboration.
6037 -- If the body is a subunit, the insertion point is before the
6038 -- stub in the parent.
6040 Prot_Bod
:= Parent
(List_Containing
(N
));
6042 if Nkind
(Parent
(Prot_Bod
)) = N_Subunit
then
6043 Prot_Bod
:= Corresponding_Stub
(Parent
(Prot_Bod
));
6046 Insert_Before
(Prot_Bod
, Prot_Decl
);
6047 Prot_Id
:= Defining_Unit_Name
(Specification
(Prot_Decl
));
6048 Set_Has_Delayed_Freeze
(Prot_Id
);
6050 Push_Scope
(Scope
(Scop
));
6051 Analyze
(Prot_Decl
);
6052 Freeze_Before
(N
, Prot_Id
);
6053 Set_Protected_Body_Subprogram
(Subp
, Prot_Id
);
6055 -- Create protected operation as well. Even though the operation
6056 -- is only accessible within the body, it is possible to make it
6057 -- available outside of the protected object by using 'Access to
6058 -- provide a callback, so build protected version in all cases.
6061 Make_Subprogram_Declaration
(Loc
,
6063 Build_Protected_Sub_Specification
(N
, Scop
, Protected_Mode
));
6064 Insert_Before
(Prot_Bod
, Prot_Decl
);
6065 Analyze
(Prot_Decl
);
6070 -- Ada 2005 (AI-348): Generate body for a null procedure. In most
6071 -- cases this is superfluous because calls to it will be automatically
6072 -- inlined, but we definitely need the body if preconditions for the
6073 -- procedure are present, or if performing coverage analysis.
6075 elsif Nkind
(Specification
(N
)) = N_Procedure_Specification
6076 and then Null_Present
(Specification
(N
))
6079 Bod
: constant Node_Id
:= Body_To_Inline
(N
);
6082 Set_Has_Completion
(Subp
, False);
6083 Append_Freeze_Action
(Subp
, Bod
);
6085 -- The body now contains raise statements, so calls to it will
6088 Set_Is_Inlined
(Subp
, False);
6092 -- When generating C code, transform a function that returns a
6093 -- constrained array type into a procedure with an out parameter
6094 -- that carries the return value.
6096 -- We skip this transformation for unchecked conversions, since they
6097 -- are not needed by the C generator (and this also produces cleaner
6100 if Modify_Tree_For_C
6101 and then Nkind
(Specification
(N
)) = N_Function_Specification
6102 and then Is_Array_Type
(Etype
(Subp
))
6103 and then Is_Constrained
(Etype
(Subp
))
6104 and then not Is_Unchecked_Conversion_Instance
(Subp
)
6106 Build_Procedure_Form
(N
);
6108 end Expand_N_Subprogram_Declaration
;
6110 --------------------------------
6111 -- Expand_Non_Function_Return --
6112 --------------------------------
6114 procedure Expand_Non_Function_Return
(N
: Node_Id
) is
6115 pragma Assert
(No
(Expression
(N
)));
6117 Loc
: constant Source_Ptr
:= Sloc
(N
);
6118 Scope_Id
: Entity_Id
:= Return_Applies_To
(Return_Statement_Entity
(N
));
6119 Kind
: constant Entity_Kind
:= Ekind
(Scope_Id
);
6122 Goto_Stat
: Node_Id
;
6126 -- Call the _Postconditions procedure if the related subprogram has
6127 -- contract assertions that need to be verified on exit.
6129 if Ekind_In
(Scope_Id
, E_Entry
, E_Entry_Family
, E_Procedure
)
6130 and then Present
(Postconditions_Proc
(Scope_Id
))
6133 Make_Procedure_Call_Statement
(Loc
,
6134 Name
=> New_Occurrence_Of
(Postconditions_Proc
(Scope_Id
), Loc
)));
6137 -- If it is a return from a procedure do no extra steps
6139 if Kind
= E_Procedure
or else Kind
= E_Generic_Procedure
then
6142 -- If it is a nested return within an extended one, replace it with a
6143 -- return of the previously declared return object.
6145 elsif Kind
= E_Return_Statement
then
6147 Make_Simple_Return_Statement
(Loc
,
6149 New_Occurrence_Of
(First_Entity
(Scope_Id
), Loc
)));
6150 Set_Comes_From_Extended_Return_Statement
(N
);
6151 Set_Return_Statement_Entity
(N
, Scope_Id
);
6152 Expand_Simple_Function_Return
(N
);
6156 pragma Assert
(Is_Entry
(Scope_Id
));
6158 -- Look at the enclosing block to see whether the return is from an
6159 -- accept statement or an entry body.
6161 for J
in reverse 0 .. Scope_Stack
.Last
loop
6162 Scope_Id
:= Scope_Stack
.Table
(J
).Entity
;
6163 exit when Is_Concurrent_Type
(Scope_Id
);
6166 -- If it is a return from accept statement it is expanded as call to
6167 -- RTS Complete_Rendezvous and a goto to the end of the accept body.
6169 -- (cf : Expand_N_Accept_Statement, Expand_N_Selective_Accept,
6170 -- Expand_N_Accept_Alternative in exp_ch9.adb)
6172 if Is_Task_Type
(Scope_Id
) then
6175 Make_Procedure_Call_Statement
(Loc
,
6176 Name
=> New_Occurrence_Of
(RTE
(RE_Complete_Rendezvous
), Loc
));
6177 Insert_Before
(N
, Call
);
6178 -- why not insert actions here???
6181 Acc_Stat
:= Parent
(N
);
6182 while Nkind
(Acc_Stat
) /= N_Accept_Statement
loop
6183 Acc_Stat
:= Parent
(Acc_Stat
);
6186 Lab_Node
:= Last
(Statements
6187 (Handled_Statement_Sequence
(Acc_Stat
)));
6189 Goto_Stat
:= Make_Goto_Statement
(Loc
,
6190 Name
=> New_Occurrence_Of
6191 (Entity
(Identifier
(Lab_Node
)), Loc
));
6193 Set_Analyzed
(Goto_Stat
);
6195 Rewrite
(N
, Goto_Stat
);
6198 -- If it is a return from an entry body, put a Complete_Entry_Body call
6199 -- in front of the return.
6201 elsif Is_Protected_Type
(Scope_Id
) then
6203 Make_Procedure_Call_Statement
(Loc
,
6205 New_Occurrence_Of
(RTE
(RE_Complete_Entry_Body
), Loc
),
6206 Parameter_Associations
=> New_List
(
6207 Make_Attribute_Reference
(Loc
,
6210 (Find_Protection_Object
(Current_Scope
), Loc
),
6211 Attribute_Name
=> Name_Unchecked_Access
)));
6213 Insert_Before
(N
, Call
);
6216 end Expand_Non_Function_Return
;
6218 ---------------------------------------
6219 -- Expand_Protected_Object_Reference --
6220 ---------------------------------------
6222 function Expand_Protected_Object_Reference
6224 Scop
: Entity_Id
) return Node_Id
6226 Loc
: constant Source_Ptr
:= Sloc
(N
);
6233 Rec
:= Make_Identifier
(Loc
, Name_uObject
);
6234 Set_Etype
(Rec
, Corresponding_Record_Type
(Scop
));
6236 -- Find enclosing protected operation, and retrieve its first parameter,
6237 -- which denotes the enclosing protected object. If the enclosing
6238 -- operation is an entry, we are immediately within the protected body,
6239 -- and we can retrieve the object from the service entries procedure. A
6240 -- barrier function has the same signature as an entry. A barrier
6241 -- function is compiled within the protected object, but unlike
6242 -- protected operations its never needs locks, so that its protected
6243 -- body subprogram points to itself.
6245 Proc
:= Current_Scope
;
6246 while Present
(Proc
)
6247 and then Scope
(Proc
) /= Scop
6249 Proc
:= Scope
(Proc
);
6252 Corr
:= Protected_Body_Subprogram
(Proc
);
6256 -- Previous error left expansion incomplete.
6257 -- Nothing to do on this call.
6264 (First
(Parameter_Specifications
(Parent
(Corr
))));
6266 if Is_Subprogram
(Proc
) and then Proc
/= Corr
then
6268 -- Protected function or procedure
6270 Set_Entity
(Rec
, Param
);
6272 -- Rec is a reference to an entity which will not be in scope when
6273 -- the call is reanalyzed, and needs no further analysis.
6278 -- Entry or barrier function for entry body. The first parameter of
6279 -- the entry body procedure is pointer to the object. We create a
6280 -- local variable of the proper type, duplicating what is done to
6281 -- define _object later on.
6285 Obj_Ptr
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
6289 Make_Full_Type_Declaration
(Loc
,
6290 Defining_Identifier
=> Obj_Ptr
,
6292 Make_Access_To_Object_Definition
(Loc
,
6293 Subtype_Indication
=>
6295 (Corresponding_Record_Type
(Scop
), Loc
))));
6297 Insert_Actions
(N
, Decls
);
6298 Freeze_Before
(N
, Obj_Ptr
);
6301 Make_Explicit_Dereference
(Loc
,
6303 Unchecked_Convert_To
(Obj_Ptr
,
6304 New_Occurrence_Of
(Param
, Loc
)));
6306 -- Analyze new actual. Other actuals in calls are already analyzed
6307 -- and the list of actuals is not reanalyzed after rewriting.
6309 Set_Parent
(Rec
, N
);
6315 end Expand_Protected_Object_Reference
;
6317 --------------------------------------
6318 -- Expand_Protected_Subprogram_Call --
6319 --------------------------------------
6321 procedure Expand_Protected_Subprogram_Call
6328 procedure Expand_Internal_Init_Call
;
6329 -- A call to an operation of the type may occur in the initialization
6330 -- of a private component. In that case the prefix of the call is an
6331 -- entity name and the call is treated as internal even though it
6332 -- appears in code outside of the protected type.
6334 procedure Freeze_Called_Function
;
6335 -- If it is a function call it can appear in elaboration code and
6336 -- the called entity must be frozen before the call. This must be
6337 -- done before the call is expanded, as the expansion may rewrite it
6338 -- to something other than a call (e.g. a temporary initialized in a
6339 -- transient block).
6341 -------------------------------
6342 -- Expand_Internal_Init_Call --
6343 -------------------------------
6345 procedure Expand_Internal_Init_Call
is
6347 -- If the context is a protected object (rather than a protected
6348 -- type) the call itself is bound to raise program_error because
6349 -- the protected body will not have been elaborated yet. This is
6350 -- diagnosed subsequently in Sem_Elab.
6352 Freeze_Called_Function
;
6354 -- The target of the internal call is the first formal of the
6355 -- enclosing initialization procedure.
6357 Rec
:= New_Occurrence_Of
(First_Formal
(Current_Scope
), Sloc
(N
));
6358 Build_Protected_Subprogram_Call
(N
,
6363 Resolve
(N
, Etype
(Subp
));
6364 end Expand_Internal_Init_Call
;
6366 ----------------------------
6367 -- Freeze_Called_Function --
6368 ----------------------------
6370 procedure Freeze_Called_Function
is
6372 if Ekind
(Subp
) = E_Function
then
6373 Freeze_Expression
(Name
(N
));
6375 end Freeze_Called_Function
;
6377 -- Start of processing for Expand_Protected_Subprogram_Call
6380 -- If the protected object is not an enclosing scope, this is an inter-
6381 -- object function call. Inter-object procedure calls are expanded by
6382 -- Exp_Ch9.Build_Simple_Entry_Call. The call is intra-object only if the
6383 -- subprogram being called is in the protected body being compiled, and
6384 -- if the protected object in the call is statically the enclosing type.
6385 -- The object may be a component of some other data structure, in which
6386 -- case this must be handled as an inter-object call.
6388 if not In_Open_Scopes
(Scop
)
6389 or else Is_Entry_Wrapper
(Current_Scope
)
6390 or else not Is_Entity_Name
(Name
(N
))
6392 if Nkind
(Name
(N
)) = N_Selected_Component
then
6393 Rec
:= Prefix
(Name
(N
));
6395 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
6396 Rec
:= Prefix
(Prefix
(Name
(N
)));
6398 -- If this is a call within an entry wrapper, it appears within a
6399 -- precondition that calls another primitive of the synchronized
6400 -- type. The target object of the call is the first actual on the
6401 -- wrapper. Note that this is an external call, because the wrapper
6402 -- is called outside of the synchronized object. This means that
6403 -- an entry call to an entry with preconditions involves two
6404 -- synchronized operations.
6406 elsif Ekind
(Current_Scope
) = E_Procedure
6407 and then Is_Entry_Wrapper
(Current_Scope
)
6409 Rec
:= New_Occurrence_Of
(First_Entity
(Current_Scope
), Sloc
(N
));
6411 -- A default parameter of a protected operation may be a call to
6412 -- a protected function of the type. This appears as an internal
6413 -- call in the profile of the operation, but if the context is an
6414 -- external call we must convert the call into an external one,
6415 -- using the protected object that is the target, so that:
6418 -- is transformed into
6421 elsif Nkind
(Parent
(N
)) = N_Procedure_Call_Statement
6422 and then Nkind
(Name
(Parent
(N
))) = N_Selected_Component
6423 and then Is_Protected_Type
(Etype
(Prefix
(Name
(Parent
(N
)))))
6424 and then Is_Entity_Name
(Name
(N
))
6425 and then Scope
(Entity
(Name
(N
))) =
6426 Etype
(Prefix
(Name
(Parent
(N
))))
6429 Make_Selected_Component
(Sloc
(N
),
6430 Prefix
=> New_Copy_Tree
(Prefix
(Name
(Parent
(N
)))),
6431 Selector_Name
=> Relocate_Node
(Name
(N
))));
6433 Analyze_And_Resolve
(N
);
6437 -- If the context is the initialization procedure for a protected
6438 -- type, the call is legal because the called entity must be a
6439 -- function of that enclosing type, and this is treated as an
6443 (Is_Entity_Name
(Name
(N
)) and then Inside_Init_Proc
);
6445 Expand_Internal_Init_Call
;
6449 Freeze_Called_Function
;
6450 Build_Protected_Subprogram_Call
(N
,
6451 Name
=> New_Occurrence_Of
(Subp
, Sloc
(N
)),
6452 Rec
=> Convert_Concurrent
(Rec
, Etype
(Rec
)),
6456 Rec
:= Expand_Protected_Object_Reference
(N
, Scop
);
6462 Freeze_Called_Function
;
6463 Build_Protected_Subprogram_Call
(N
,
6469 -- Analyze and resolve the new call. The actuals have already been
6470 -- resolved, but expansion of a function call will add extra actuals
6471 -- if needed. Analysis of a procedure call already includes resolution.
6475 if Ekind
(Subp
) = E_Function
then
6476 Resolve
(N
, Etype
(Subp
));
6478 end Expand_Protected_Subprogram_Call
;
6480 -----------------------------------
6481 -- Expand_Simple_Function_Return --
6482 -----------------------------------
6484 -- The "simple" comes from the syntax rule simple_return_statement. The
6485 -- semantics are not at all simple.
6487 procedure Expand_Simple_Function_Return
(N
: Node_Id
) is
6488 Loc
: constant Source_Ptr
:= Sloc
(N
);
6490 Scope_Id
: constant Entity_Id
:=
6491 Return_Applies_To
(Return_Statement_Entity
(N
));
6492 -- The function we are returning from
6494 R_Type
: constant Entity_Id
:= Etype
(Scope_Id
);
6495 -- The result type of the function
6497 Utyp
: constant Entity_Id
:= Underlying_Type
(R_Type
);
6499 Exp
: Node_Id
:= Expression
(N
);
6500 pragma Assert
(Present
(Exp
));
6502 Exptyp
: constant Entity_Id
:= Etype
(Exp
);
6503 -- The type of the expression (not necessarily the same as R_Type)
6505 Subtype_Ind
: Node_Id
;
6506 -- If the result type of the function is class-wide and the expression
6507 -- has a specific type, then we use the expression's type as the type of
6508 -- the return object. In cases where the expression is an aggregate that
6509 -- is built in place, this avoids the need for an expensive conversion
6510 -- of the return object to the specific type on assignments to the
6511 -- individual components.
6514 if Is_Class_Wide_Type
(R_Type
)
6515 and then not Is_Class_Wide_Type
(Exptyp
)
6516 and then Nkind
(Exp
) /= N_Type_Conversion
6518 Subtype_Ind
:= New_Occurrence_Of
(Exptyp
, Loc
);
6520 Subtype_Ind
:= New_Occurrence_Of
(R_Type
, Loc
);
6522 -- If the result type is class-wide and the expression is a view
6523 -- conversion, the conversion plays no role in the expansion because
6524 -- it does not modify the tag of the object. Remove the conversion
6525 -- altogether to prevent tag overwriting.
6527 if Is_Class_Wide_Type
(R_Type
)
6528 and then not Is_Class_Wide_Type
(Exptyp
)
6529 and then Nkind
(Exp
) = N_Type_Conversion
6531 Exp
:= Expression
(Exp
);
6535 -- Assert that if F says "return G(...);"
6536 -- then F and G are both b-i-p, or neither b-i-p.
6538 if Nkind
(Exp
) = N_Function_Call
then
6539 pragma Assert
(Ekind
(Scope_Id
) = E_Function
);
6541 (Is_Build_In_Place_Function
(Scope_Id
) =
6542 Is_Build_In_Place_Function_Call
(Exp
));
6546 -- For the case of a simple return that does not come from an
6547 -- extended return, in the case of build-in-place, we rewrite
6548 -- "return <expression>;" to be:
6550 -- return _anon_ : <return_subtype> := <expression>
6552 -- The expansion produced by Expand_N_Extended_Return_Statement will
6553 -- contain simple return statements (for example, a block containing
6554 -- simple return of the return object), which brings us back here with
6555 -- Comes_From_Extended_Return_Statement set. The reason for the barrier
6556 -- checking for a simple return that does not come from an extended
6557 -- return is to avoid this infinite recursion.
6559 -- The reason for this design is that for Ada 2005 limited returns, we
6560 -- need to reify the return object, so we can build it "in place", and
6561 -- we need a block statement to hang finalization and tasking stuff.
6563 -- ??? In order to avoid disruption, we avoid translating to extended
6564 -- return except in the cases where we really need to (Ada 2005 for
6565 -- inherently limited). We might prefer to do this translation in all
6566 -- cases (except perhaps for the case of Ada 95 inherently limited),
6567 -- in order to fully exercise the Expand_N_Extended_Return_Statement
6568 -- code. This would also allow us to do the build-in-place optimization
6569 -- for efficiency even in cases where it is semantically not required.
6571 -- As before, we check the type of the return expression rather than the
6572 -- return type of the function, because the latter may be a limited
6573 -- class-wide interface type, which is not a limited type, even though
6574 -- the type of the expression may be.
6577 (Comes_From_Extended_Return_Statement
(N
)
6578 or else not Is_Build_In_Place_Function_Call
(Exp
)
6579 or else Is_Build_In_Place_Function
(Scope_Id
));
6581 if not Comes_From_Extended_Return_Statement
(N
)
6582 and then Is_Build_In_Place_Function
(Scope_Id
)
6583 and then not Debug_Flag_Dot_L
6585 -- The functionality of interface thunks is simple and it is always
6586 -- handled by means of simple return statements. This leaves their
6587 -- expansion simple and clean.
6589 and then not Is_Thunk
(Current_Scope
)
6592 Return_Object_Entity
: constant Entity_Id
:=
6593 Make_Temporary
(Loc
, 'R', Exp
);
6595 Obj_Decl
: constant Node_Id
:=
6596 Make_Object_Declaration
(Loc
,
6597 Defining_Identifier
=> Return_Object_Entity
,
6598 Object_Definition
=> Subtype_Ind
,
6601 Ext
: constant Node_Id
:=
6602 Make_Extended_Return_Statement
(Loc
,
6603 Return_Object_Declarations
=> New_List
(Obj_Decl
));
6604 -- Do not perform this high-level optimization if the result type
6605 -- is an interface because the "this" pointer must be displaced.
6614 -- Here we have a simple return statement that is part of the expansion
6615 -- of an extended return statement (either written by the user, or
6616 -- generated by the above code).
6618 -- Always normalize C/Fortran boolean result. This is not always needed,
6619 -- but it seems a good idea to minimize the passing around of non-
6620 -- normalized values, and in any case this handles the processing of
6621 -- barrier functions for protected types, which turn the condition into
6622 -- a return statement.
6624 if Is_Boolean_Type
(Exptyp
)
6625 and then Nonzero_Is_True
(Exptyp
)
6627 Adjust_Condition
(Exp
);
6628 Adjust_Result_Type
(Exp
, Exptyp
);
6631 -- Do validity check if enabled for returns
6633 if Validity_Checks_On
6634 and then Validity_Check_Returns
6639 -- Check the result expression of a scalar function against the subtype
6640 -- of the function by inserting a conversion. This conversion must
6641 -- eventually be performed for other classes of types, but for now it's
6642 -- only done for scalars.
6645 if Is_Scalar_Type
(Exptyp
) then
6646 Rewrite
(Exp
, Convert_To
(R_Type
, Exp
));
6648 -- The expression is resolved to ensure that the conversion gets
6649 -- expanded to generate a possible constraint check.
6651 Analyze_And_Resolve
(Exp
, R_Type
);
6654 -- Deal with returning variable length objects and controlled types
6656 -- Nothing to do if we are returning by reference, or this is not a
6657 -- type that requires special processing (indicated by the fact that
6658 -- it requires a cleanup scope for the secondary stack case).
6660 if Is_Build_In_Place_Function
(Scope_Id
)
6661 or else Is_Limited_Interface
(Exptyp
)
6665 -- No copy needed for thunks returning interface type objects since
6666 -- the object is returned by reference and the maximum functionality
6667 -- required is just to displace the pointer.
6669 elsif Is_Thunk
(Current_Scope
) and then Is_Interface
(Exptyp
) then
6672 -- If the call is within a thunk and the type is a limited view, the
6673 -- backend will eventually see the non-limited view of the type.
6675 elsif Is_Thunk
(Current_Scope
) and then Is_Incomplete_Type
(Exptyp
) then
6678 elsif not Requires_Transient_Scope
(R_Type
) then
6680 -- Mutable records with variable-length components are not returned
6681 -- on the sec-stack, so we need to make sure that the back end will
6682 -- only copy back the size of the actual value, and not the maximum
6683 -- size. We create an actual subtype for this purpose. However we
6684 -- need not do it if the expression is a function call since this
6685 -- will be done in the called function and doing it here too would
6686 -- cause a temporary with maximum size to be created.
6689 Ubt
: constant Entity_Id
:= Underlying_Type
(Base_Type
(Exptyp
));
6693 if Nkind
(Exp
) /= N_Function_Call
6694 and then Has_Discriminants
(Ubt
)
6695 and then not Is_Constrained
(Ubt
)
6696 and then not Has_Unchecked_Union
(Ubt
)
6698 Decl
:= Build_Actual_Subtype
(Ubt
, Exp
);
6699 Ent
:= Defining_Identifier
(Decl
);
6700 Insert_Action
(Exp
, Decl
);
6701 Rewrite
(Exp
, Unchecked_Convert_To
(Ent
, Exp
));
6702 Analyze_And_Resolve
(Exp
);
6706 -- Here if secondary stack is used
6709 -- Prevent the reclamation of the secondary stack by all enclosing
6710 -- blocks and loops as well as the related function; otherwise the
6711 -- result would be reclaimed too early.
6713 Set_Enclosing_Sec_Stack_Return
(N
);
6715 -- Optimize the case where the result is a function call. In this
6716 -- case either the result is already on the secondary stack, or is
6717 -- already being returned with the stack pointer depressed and no
6718 -- further processing is required except to set the By_Ref flag
6719 -- to ensure that gigi does not attempt an extra unnecessary copy.
6720 -- (actually not just unnecessary but harmfully wrong in the case
6721 -- of a controlled type, where gigi does not know how to do a copy).
6722 -- To make up for a gcc 2.8.1 deficiency (???), we perform the copy
6723 -- for array types if the constrained status of the target type is
6724 -- different from that of the expression.
6726 if Requires_Transient_Scope
(Exptyp
)
6728 (not Is_Array_Type
(Exptyp
)
6729 or else Is_Constrained
(Exptyp
) = Is_Constrained
(R_Type
)
6730 or else CW_Or_Has_Controlled_Part
(Utyp
))
6731 and then Nkind
(Exp
) = N_Function_Call
6735 -- Remove side effects from the expression now so that other parts
6736 -- of the expander do not have to reanalyze this node without this
6739 Rewrite
(Exp
, Duplicate_Subexpr_No_Checks
(Exp
));
6741 -- Ada 2005 (AI-251): If the type of the returned object is
6742 -- an interface then add an implicit type conversion to force
6743 -- displacement of the "this" pointer.
6745 if Is_Interface
(R_Type
) then
6746 Rewrite
(Exp
, Convert_To
(R_Type
, Relocate_Node
(Exp
)));
6749 Analyze_And_Resolve
(Exp
, R_Type
);
6751 -- For controlled types, do the allocation on the secondary stack
6752 -- manually in order to call adjust at the right time:
6754 -- type Anon1 is access R_Type;
6755 -- for Anon1'Storage_pool use ss_pool;
6756 -- Anon2 : anon1 := new R_Type'(expr);
6757 -- return Anon2.all;
6759 -- We do the same for classwide types that are not potentially
6760 -- controlled (by the virtue of restriction No_Finalization) because
6761 -- gigi is not able to properly allocate class-wide types.
6763 elsif CW_Or_Has_Controlled_Part
(Utyp
) then
6765 Loc
: constant Source_Ptr
:= Sloc
(N
);
6766 Acc_Typ
: constant Entity_Id
:= Make_Temporary
(Loc
, 'A');
6767 Alloc_Node
: Node_Id
;
6771 Set_Ekind
(Acc_Typ
, E_Access_Type
);
6773 Set_Associated_Storage_Pool
(Acc_Typ
, RTE
(RE_SS_Pool
));
6775 -- This is an allocator for the secondary stack, and it's fine
6776 -- to have Comes_From_Source set False on it, as gigi knows not
6777 -- to flag it as a violation of No_Implicit_Heap_Allocations.
6780 Make_Allocator
(Loc
,
6782 Make_Qualified_Expression
(Loc
,
6783 Subtype_Mark
=> New_Occurrence_Of
(Etype
(Exp
), Loc
),
6784 Expression
=> Relocate_Node
(Exp
)));
6786 -- We do not want discriminant checks on the declaration,
6787 -- given that it gets its value from the allocator.
6789 Set_No_Initialization
(Alloc_Node
);
6791 Temp
:= Make_Temporary
(Loc
, 'R', Alloc_Node
);
6793 Insert_List_Before_And_Analyze
(N
, New_List
(
6794 Make_Full_Type_Declaration
(Loc
,
6795 Defining_Identifier
=> Acc_Typ
,
6797 Make_Access_To_Object_Definition
(Loc
,
6798 Subtype_Indication
=> Subtype_Ind
)),
6800 Make_Object_Declaration
(Loc
,
6801 Defining_Identifier
=> Temp
,
6802 Object_Definition
=> New_Occurrence_Of
(Acc_Typ
, Loc
),
6803 Expression
=> Alloc_Node
)));
6806 Make_Explicit_Dereference
(Loc
,
6807 Prefix
=> New_Occurrence_Of
(Temp
, Loc
)));
6809 -- Ada 2005 (AI-251): If the type of the returned object is
6810 -- an interface then add an implicit type conversion to force
6811 -- displacement of the "this" pointer.
6813 if Is_Interface
(R_Type
) then
6814 Rewrite
(Exp
, Convert_To
(R_Type
, Relocate_Node
(Exp
)));
6817 Analyze_And_Resolve
(Exp
, R_Type
);
6820 -- Otherwise use the gigi mechanism to allocate result on the
6824 Check_Restriction
(No_Secondary_Stack
, N
);
6825 Set_Storage_Pool
(N
, RTE
(RE_SS_Pool
));
6826 Set_Procedure_To_Call
(N
, RTE
(RE_SS_Allocate
));
6830 -- Implement the rules of 6.5(8-10), which require a tag check in
6831 -- the case of a limited tagged return type, and tag reassignment for
6832 -- nonlimited tagged results. These actions are needed when the return
6833 -- type is a specific tagged type and the result expression is a
6834 -- conversion or a formal parameter, because in that case the tag of
6835 -- the expression might differ from the tag of the specific result type.
6837 -- We must also verify an underlying type exists for the return type in
6838 -- case it is incomplete - in which case is not necessary to generate a
6839 -- check anyway since an incomplete limited tagged return type would
6840 -- qualify as a premature usage.
6843 and then Is_Tagged_Type
(Utyp
)
6844 and then not Is_Class_Wide_Type
(Utyp
)
6845 and then (Nkind_In
(Exp
, N_Type_Conversion
,
6846 N_Unchecked_Type_Conversion
)
6847 or else (Is_Entity_Name
(Exp
)
6848 and then Is_Formal
(Entity
(Exp
))))
6850 -- When the return type is limited, perform a check that the tag of
6851 -- the result is the same as the tag of the return type.
6853 if Is_Limited_Type
(R_Type
) then
6855 Make_Raise_Constraint_Error
(Loc
,
6859 Make_Selected_Component
(Loc
,
6860 Prefix
=> Duplicate_Subexpr
(Exp
),
6861 Selector_Name
=> Make_Identifier
(Loc
, Name_uTag
)),
6863 Make_Attribute_Reference
(Loc
,
6865 New_Occurrence_Of
(Base_Type
(Utyp
), Loc
),
6866 Attribute_Name
=> Name_Tag
)),
6867 Reason
=> CE_Tag_Check_Failed
));
6869 -- If the result type is a specific nonlimited tagged type, then we
6870 -- have to ensure that the tag of the result is that of the result
6871 -- type. This is handled by making a copy of the expression in
6872 -- the case where it might have a different tag, namely when the
6873 -- expression is a conversion or a formal parameter. We create a new
6874 -- object of the result type and initialize it from the expression,
6875 -- which will implicitly force the tag to be set appropriately.
6879 ExpR
: constant Node_Id
:= Relocate_Node
(Exp
);
6880 Result_Id
: constant Entity_Id
:=
6881 Make_Temporary
(Loc
, 'R', ExpR
);
6882 Result_Exp
: constant Node_Id
:=
6883 New_Occurrence_Of
(Result_Id
, Loc
);
6884 Result_Obj
: constant Node_Id
:=
6885 Make_Object_Declaration
(Loc
,
6886 Defining_Identifier
=> Result_Id
,
6887 Object_Definition
=>
6888 New_Occurrence_Of
(R_Type
, Loc
),
6889 Constant_Present
=> True,
6890 Expression
=> ExpR
);
6893 Set_Assignment_OK
(Result_Obj
);
6894 Insert_Action
(Exp
, Result_Obj
);
6896 Rewrite
(Exp
, Result_Exp
);
6897 Analyze_And_Resolve
(Exp
, R_Type
);
6901 -- Ada 2005 (AI-344): If the result type is class-wide, then insert
6902 -- a check that the level of the return expression's underlying type
6903 -- is not deeper than the level of the master enclosing the function.
6904 -- Always generate the check when the type of the return expression
6905 -- is class-wide, when it's a type conversion, or when it's a formal
6906 -- parameter. Otherwise, suppress the check in the case where the
6907 -- return expression has a specific type whose level is known not to
6908 -- be statically deeper than the function's result type.
6910 -- No runtime check needed in interface thunks since it is performed
6911 -- by the target primitive associated with the thunk.
6913 -- Note: accessibility check is skipped in the VM case, since there
6914 -- does not seem to be any practical way to implement this check.
6916 elsif Ada_Version
>= Ada_2005
6917 and then Tagged_Type_Expansion
6918 and then Is_Class_Wide_Type
(R_Type
)
6919 and then not Is_Thunk
(Current_Scope
)
6920 and then not Scope_Suppress
.Suppress
(Accessibility_Check
)
6922 (Is_Class_Wide_Type
(Etype
(Exp
))
6923 or else Nkind_In
(Exp
, N_Type_Conversion
,
6924 N_Unchecked_Type_Conversion
)
6925 or else (Is_Entity_Name
(Exp
)
6926 and then Is_Formal
(Entity
(Exp
)))
6927 or else Scope_Depth
(Enclosing_Dynamic_Scope
(Etype
(Exp
))) >
6928 Scope_Depth
(Enclosing_Dynamic_Scope
(Scope_Id
)))
6934 -- Ada 2005 (AI-251): In class-wide interface objects we displace
6935 -- "this" to reference the base of the object. This is required to
6936 -- get access to the TSD of the object.
6938 if Is_Class_Wide_Type
(Etype
(Exp
))
6939 and then Is_Interface
(Etype
(Exp
))
6941 -- If the expression is an explicit dereference then we can
6942 -- directly displace the pointer to reference the base of
6945 if Nkind
(Exp
) = N_Explicit_Dereference
then
6947 Make_Explicit_Dereference
(Loc
,
6949 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6950 Make_Function_Call
(Loc
,
6952 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6953 Parameter_Associations
=> New_List
(
6954 Unchecked_Convert_To
(RTE
(RE_Address
),
6955 Duplicate_Subexpr
(Prefix
(Exp
)))))));
6957 -- Similar case to the previous one but the expression is a
6958 -- renaming of an explicit dereference.
6960 elsif Nkind
(Exp
) = N_Identifier
6961 and then Present
(Renamed_Object
(Entity
(Exp
)))
6962 and then Nkind
(Renamed_Object
(Entity
(Exp
)))
6963 = N_Explicit_Dereference
6966 Make_Explicit_Dereference
(Loc
,
6968 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6969 Make_Function_Call
(Loc
,
6971 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6972 Parameter_Associations
=> New_List
(
6973 Unchecked_Convert_To
(RTE
(RE_Address
),
6976 (Renamed_Object
(Entity
(Exp
)))))))));
6978 -- Common case: obtain the address of the actual object and
6979 -- displace the pointer to reference the base of the object.
6983 Make_Explicit_Dereference
(Loc
,
6985 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6986 Make_Function_Call
(Loc
,
6988 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6989 Parameter_Associations
=> New_List
(
6990 Make_Attribute_Reference
(Loc
,
6991 Prefix
=> Duplicate_Subexpr
(Exp
),
6992 Attribute_Name
=> Name_Address
)))));
6996 Make_Attribute_Reference
(Loc
,
6997 Prefix
=> Duplicate_Subexpr
(Exp
),
6998 Attribute_Name
=> Name_Tag
);
7001 -- CodePeer does not do anything useful with
7002 -- Ada.Tags.Type_Specific_Data components.
7004 if not CodePeer_Mode
then
7006 Make_Raise_Program_Error
(Loc
,
7009 Left_Opnd
=> Build_Get_Access_Level
(Loc
, Tag_Node
),
7011 Make_Integer_Literal
(Loc
,
7012 Scope_Depth
(Enclosing_Dynamic_Scope
(Scope_Id
)))),
7013 Reason
=> PE_Accessibility_Check_Failed
));
7017 -- AI05-0073: If function has a controlling access result, check that
7018 -- the tag of the return value, if it is not null, matches designated
7019 -- type of return type.
7021 -- The return expression is referenced twice in the code below, so it
7022 -- must be made free of side effects. Given that different compilers
7023 -- may evaluate these parameters in different order, both occurrences
7026 elsif Ekind
(R_Type
) = E_Anonymous_Access_Type
7027 and then Has_Controlling_Result
(Scope_Id
)
7030 Make_Raise_Constraint_Error
(Loc
,
7035 Left_Opnd
=> Duplicate_Subexpr
(Exp
),
7036 Right_Opnd
=> Make_Null
(Loc
)),
7038 Right_Opnd
=> Make_Op_Ne
(Loc
,
7040 Make_Selected_Component
(Loc
,
7041 Prefix
=> Duplicate_Subexpr
(Exp
),
7042 Selector_Name
=> Make_Identifier
(Loc
, Name_uTag
)),
7045 Make_Attribute_Reference
(Loc
,
7047 New_Occurrence_Of
(Designated_Type
(R_Type
), Loc
),
7048 Attribute_Name
=> Name_Tag
))),
7050 Reason
=> CE_Tag_Check_Failed
),
7051 Suppress
=> All_Checks
);
7054 -- AI05-0234: RM 6.5(21/3). Check access discriminants to
7055 -- ensure that the function result does not outlive an
7056 -- object designated by one of it discriminants.
7058 if Present
(Extra_Accessibility_Of_Result
(Scope_Id
))
7059 and then Has_Unconstrained_Access_Discriminants
(R_Type
)
7062 Discrim_Source
: Node_Id
;
7064 procedure Check_Against_Result_Level
(Level
: Node_Id
);
7065 -- Check the given accessibility level against the level
7066 -- determined by the point of call. (AI05-0234).
7068 --------------------------------
7069 -- Check_Against_Result_Level --
7070 --------------------------------
7072 procedure Check_Against_Result_Level
(Level
: Node_Id
) is
7075 Make_Raise_Program_Error
(Loc
,
7081 (Extra_Accessibility_Of_Result
(Scope_Id
), Loc
)),
7082 Reason
=> PE_Accessibility_Check_Failed
));
7083 end Check_Against_Result_Level
;
7086 Discrim_Source
:= Exp
;
7087 while Nkind
(Discrim_Source
) = N_Qualified_Expression
loop
7088 Discrim_Source
:= Expression
(Discrim_Source
);
7091 if Nkind
(Discrim_Source
) = N_Identifier
7092 and then Is_Return_Object
(Entity
(Discrim_Source
))
7094 Discrim_Source
:= Entity
(Discrim_Source
);
7096 if Is_Constrained
(Etype
(Discrim_Source
)) then
7097 Discrim_Source
:= Etype
(Discrim_Source
);
7099 Discrim_Source
:= Expression
(Parent
(Discrim_Source
));
7102 elsif Nkind
(Discrim_Source
) = N_Identifier
7103 and then Nkind_In
(Original_Node
(Discrim_Source
),
7104 N_Aggregate
, N_Extension_Aggregate
)
7106 Discrim_Source
:= Original_Node
(Discrim_Source
);
7108 elsif Nkind
(Discrim_Source
) = N_Explicit_Dereference
and then
7109 Nkind
(Original_Node
(Discrim_Source
)) = N_Function_Call
7111 Discrim_Source
:= Original_Node
(Discrim_Source
);
7114 Discrim_Source
:= Unqual_Conv
(Discrim_Source
);
7116 case Nkind
(Discrim_Source
) is
7117 when N_Defining_Identifier
=>
7118 pragma Assert
(Is_Composite_Type
(Discrim_Source
)
7119 and then Has_Discriminants
(Discrim_Source
)
7120 and then Is_Constrained
(Discrim_Source
));
7123 Discrim
: Entity_Id
:=
7124 First_Discriminant
(Base_Type
(R_Type
));
7125 Disc_Elmt
: Elmt_Id
:=
7126 First_Elmt
(Discriminant_Constraint
7130 if Ekind
(Etype
(Discrim
)) =
7131 E_Anonymous_Access_Type
7133 Check_Against_Result_Level
7134 (Dynamic_Accessibility_Level
(Node
(Disc_Elmt
)));
7137 Next_Elmt
(Disc_Elmt
);
7138 Next_Discriminant
(Discrim
);
7139 exit when not Present
(Discrim
);
7144 | N_Extension_Aggregate
7146 -- Unimplemented: extension aggregate case where discrims
7147 -- come from ancestor part, not extension part.
7150 Discrim
: Entity_Id
:=
7151 First_Discriminant
(Base_Type
(R_Type
));
7153 Disc_Exp
: Node_Id
:= Empty
;
7155 Positionals_Exhausted
7156 : Boolean := not Present
(Expressions
7159 function Associated_Expr
7160 (Comp_Id
: Entity_Id
;
7161 Associations
: List_Id
) return Node_Id
;
7163 -- Given a component and a component associations list,
7164 -- locate the expression for that component; returns
7165 -- Empty if no such expression is found.
7167 ---------------------
7168 -- Associated_Expr --
7169 ---------------------
7171 function Associated_Expr
7172 (Comp_Id
: Entity_Id
;
7173 Associations
: List_Id
) return Node_Id
7179 -- Simple linear search seems ok here
7181 Assoc
:= First
(Associations
);
7182 while Present
(Assoc
) loop
7183 Choice
:= First
(Choices
(Assoc
));
7184 while Present
(Choice
) loop
7185 if (Nkind
(Choice
) = N_Identifier
7186 and then Chars
(Choice
) = Chars
(Comp_Id
))
7187 or else (Nkind
(Choice
) = N_Others_Choice
)
7189 return Expression
(Assoc
);
7199 end Associated_Expr
;
7202 if not Positionals_Exhausted
then
7203 Disc_Exp
:= First
(Expressions
(Discrim_Source
));
7207 if Positionals_Exhausted
then
7211 Component_Associations
(Discrim_Source
));
7214 if Ekind
(Etype
(Discrim
)) =
7215 E_Anonymous_Access_Type
7217 Check_Against_Result_Level
7218 (Dynamic_Accessibility_Level
(Disc_Exp
));
7221 Next_Discriminant
(Discrim
);
7222 exit when not Present
(Discrim
);
7224 if not Positionals_Exhausted
then
7226 Positionals_Exhausted
:= not Present
(Disc_Exp
);
7231 when N_Function_Call
=>
7233 -- No check needed (check performed by callee)
7239 Level
: constant Node_Id
:=
7240 Make_Integer_Literal
(Loc
,
7241 Object_Access_Level
(Discrim_Source
));
7244 -- Unimplemented: check for name prefix that includes
7245 -- a dereference of an access value with a dynamic
7246 -- accessibility level (e.g., an access param or a
7247 -- saooaaat) and use dynamic level in that case. For
7249 -- return Access_Param.all(Some_Index).Some_Component;
7252 Set_Etype
(Level
, Standard_Natural
);
7253 Check_Against_Result_Level
(Level
);
7259 -- If we are returning an object that may not be bit-aligned, then copy
7260 -- the value into a temporary first. This copy may need to expand to a
7261 -- loop of component operations.
7263 if Is_Possibly_Unaligned_Slice
(Exp
)
7264 or else Is_Possibly_Unaligned_Object
(Exp
)
7267 ExpR
: constant Node_Id
:= Relocate_Node
(Exp
);
7268 Tnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T', ExpR
);
7271 Make_Object_Declaration
(Loc
,
7272 Defining_Identifier
=> Tnn
,
7273 Constant_Present
=> True,
7274 Object_Definition
=> New_Occurrence_Of
(R_Type
, Loc
),
7275 Expression
=> ExpR
),
7276 Suppress
=> All_Checks
);
7277 Rewrite
(Exp
, New_Occurrence_Of
(Tnn
, Loc
));
7281 -- Call the _Postconditions procedure if the related function has
7282 -- contract assertions that need to be verified on exit.
7284 if Ekind
(Scope_Id
) = E_Function
7285 and then Present
(Postconditions_Proc
(Scope_Id
))
7287 -- In the case of discriminated objects, we have created a
7288 -- constrained subtype above, and used the underlying type. This
7289 -- transformation is post-analysis and harmless, except that now the
7290 -- call to the post-condition will be analyzed and the type kinds
7293 if Nkind
(Exp
) = N_Unchecked_Type_Conversion
7294 and then Is_Private_Type
(R_Type
) /= Is_Private_Type
(Etype
(Exp
))
7296 Rewrite
(Exp
, Expression
(Relocate_Node
(Exp
)));
7299 -- We are going to reference the returned value twice in this case,
7300 -- once in the call to _Postconditions, and once in the actual return
7301 -- statement, but we can't have side effects happening twice.
7303 Force_Evaluation
(Exp
, Mode
=> Strict
);
7305 -- Generate call to _Postconditions
7308 Make_Procedure_Call_Statement
(Loc
,
7310 New_Occurrence_Of
(Postconditions_Proc
(Scope_Id
), Loc
),
7311 Parameter_Associations
=> New_List
(New_Copy_Tree
(Exp
))));
7314 -- Ada 2005 (AI-251): If this return statement corresponds with an
7315 -- simple return statement associated with an extended return statement
7316 -- and the type of the returned object is an interface then generate an
7317 -- implicit conversion to force displacement of the "this" pointer.
7319 if Ada_Version
>= Ada_2005
7320 and then Comes_From_Extended_Return_Statement
(N
)
7321 and then Nkind
(Expression
(N
)) = N_Identifier
7322 and then Is_Interface
(Utyp
)
7323 and then Utyp
/= Underlying_Type
(Exptyp
)
7325 Rewrite
(Exp
, Convert_To
(Utyp
, Relocate_Node
(Exp
)));
7326 Analyze_And_Resolve
(Exp
);
7328 end Expand_Simple_Function_Return
;
7330 -----------------------
7331 -- Freeze_Subprogram --
7332 -----------------------
7334 procedure Freeze_Subprogram
(N
: Node_Id
) is
7335 Loc
: constant Source_Ptr
:= Sloc
(N
);
7337 procedure Register_Predefined_DT_Entry
(Prim
: Entity_Id
);
7338 -- (Ada 2005): Register a predefined primitive in all the secondary
7339 -- dispatch tables of its primitive type.
7341 ----------------------------------
7342 -- Register_Predefined_DT_Entry --
7343 ----------------------------------
7345 procedure Register_Predefined_DT_Entry
(Prim
: Entity_Id
) is
7346 Iface_DT_Ptr
: Elmt_Id
;
7347 Tagged_Typ
: Entity_Id
;
7348 Thunk_Id
: Entity_Id
;
7349 Thunk_Code
: Node_Id
;
7352 Tagged_Typ
:= Find_Dispatching_Type
(Prim
);
7354 if No
(Access_Disp_Table
(Tagged_Typ
))
7355 or else not Has_Interfaces
(Tagged_Typ
)
7356 or else not RTE_Available
(RE_Interface_Tag
)
7357 or else Restriction_Active
(No_Dispatching_Calls
)
7362 -- Skip the first two access-to-dispatch-table pointers since they
7363 -- leads to the primary dispatch table (predefined DT and user
7364 -- defined DT). We are only concerned with the secondary dispatch
7365 -- table pointers. Note that the access-to- dispatch-table pointer
7366 -- corresponds to the first implemented interface retrieved below.
7369 Next_Elmt
(Next_Elmt
(First_Elmt
(Access_Disp_Table
(Tagged_Typ
))));
7371 while Present
(Iface_DT_Ptr
)
7372 and then Ekind
(Node
(Iface_DT_Ptr
)) = E_Constant
7374 pragma Assert
(Has_Thunks
(Node
(Iface_DT_Ptr
)));
7375 Expand_Interface_Thunk
(Prim
, Thunk_Id
, Thunk_Code
);
7377 if Present
(Thunk_Code
) then
7378 Insert_Actions_After
(N
, New_List
(
7381 Build_Set_Predefined_Prim_Op_Address
(Loc
,
7383 New_Occurrence_Of
(Node
(Next_Elmt
(Iface_DT_Ptr
)), Loc
),
7384 Position
=> DT_Position
(Prim
),
7386 Unchecked_Convert_To
(RTE
(RE_Prim_Ptr
),
7387 Make_Attribute_Reference
(Loc
,
7388 Prefix
=> New_Occurrence_Of
(Thunk_Id
, Loc
),
7389 Attribute_Name
=> Name_Unrestricted_Access
))),
7391 Build_Set_Predefined_Prim_Op_Address
(Loc
,
7394 (Node
(Next_Elmt
(Next_Elmt
(Next_Elmt
(Iface_DT_Ptr
)))),
7396 Position
=> DT_Position
(Prim
),
7398 Unchecked_Convert_To
(RTE
(RE_Prim_Ptr
),
7399 Make_Attribute_Reference
(Loc
,
7400 Prefix
=> New_Occurrence_Of
(Prim
, Loc
),
7401 Attribute_Name
=> Name_Unrestricted_Access
)))));
7404 -- Skip the tag of the predefined primitives dispatch table
7406 Next_Elmt
(Iface_DT_Ptr
);
7407 pragma Assert
(Has_Thunks
(Node
(Iface_DT_Ptr
)));
7409 -- Skip tag of the no-thunks dispatch table
7411 Next_Elmt
(Iface_DT_Ptr
);
7412 pragma Assert
(not Has_Thunks
(Node
(Iface_DT_Ptr
)));
7414 -- Skip tag of predefined primitives no-thunks dispatch table
7416 Next_Elmt
(Iface_DT_Ptr
);
7417 pragma Assert
(not Has_Thunks
(Node
(Iface_DT_Ptr
)));
7419 Next_Elmt
(Iface_DT_Ptr
);
7421 end Register_Predefined_DT_Entry
;
7425 Subp
: constant Entity_Id
:= Entity
(N
);
7427 -- Start of processing for Freeze_Subprogram
7430 -- We suppress the initialization of the dispatch table entry when
7431 -- not Tagged_Type_Expansion because the dispatching mechanism is
7432 -- handled internally by the target.
7434 if Is_Dispatching_Operation
(Subp
)
7435 and then not Is_Abstract_Subprogram
(Subp
)
7436 and then Present
(DTC_Entity
(Subp
))
7437 and then Present
(Scope
(DTC_Entity
(Subp
)))
7438 and then Tagged_Type_Expansion
7439 and then not Restriction_Active
(No_Dispatching_Calls
)
7440 and then RTE_Available
(RE_Tag
)
7443 Typ
: constant Entity_Id
:= Scope
(DTC_Entity
(Subp
));
7446 -- Handle private overridden primitives
7448 if not Is_CPP_Class
(Typ
) then
7449 Check_Overriding_Operation
(Subp
);
7452 -- We assume that imported CPP primitives correspond with objects
7453 -- whose constructor is in the CPP side; therefore we don't need
7454 -- to generate code to register them in the dispatch table.
7456 if Is_CPP_Class
(Typ
) then
7459 -- Handle CPP primitives found in derivations of CPP_Class types.
7460 -- These primitives must have been inherited from some parent, and
7461 -- there is no need to register them in the dispatch table because
7462 -- Build_Inherit_Prims takes care of initializing these slots.
7464 elsif Is_Imported
(Subp
)
7465 and then (Convention
(Subp
) = Convention_CPP
7466 or else Convention
(Subp
) = Convention_C
)
7470 -- Generate code to register the primitive in non statically
7471 -- allocated dispatch tables
7473 elsif not Building_Static_DT
(Scope
(DTC_Entity
(Subp
))) then
7475 -- When a primitive is frozen, enter its name in its dispatch
7478 if not Is_Interface
(Typ
)
7479 or else Present
(Interface_Alias
(Subp
))
7481 if Is_Predefined_Dispatching_Operation
(Subp
) then
7482 Register_Predefined_DT_Entry
(Subp
);
7485 Insert_Actions_After
(N
,
7486 Register_Primitive
(Loc
, Prim
=> Subp
));
7492 -- Mark functions that return by reference. Note that it cannot be part
7493 -- of the normal semantic analysis of the spec since the underlying
7494 -- returned type may not be known yet (for private types).
7497 Typ
: constant Entity_Id
:= Etype
(Subp
);
7498 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
7501 if Is_Limited_View
(Typ
) then
7502 Set_Returns_By_Ref
(Subp
);
7504 elsif Present
(Utyp
) and then CW_Or_Has_Controlled_Part
(Utyp
) then
7505 Set_Returns_By_Ref
(Subp
);
7509 -- Wnen freezing a null procedure, analyze its delayed aspects now
7510 -- because we may not have reached the end of the declarative list when
7511 -- delayed aspects are normally analyzed. This ensures that dispatching
7512 -- calls are properly rewritten when the generated _Postcondition
7513 -- procedure is analyzed in the null procedure body.
7515 if Nkind
(Parent
(Subp
)) = N_Procedure_Specification
7516 and then Null_Present
(Parent
(Subp
))
7518 Analyze_Entry_Or_Subprogram_Contract
(Subp
);
7520 end Freeze_Subprogram
;
7522 --------------------------------------------
7523 -- Has_Unconstrained_Access_Discriminants --
7524 --------------------------------------------
7526 function Has_Unconstrained_Access_Discriminants
7527 (Subtyp
: Entity_Id
) return Boolean
7532 if Has_Discriminants
(Subtyp
)
7533 and then not Is_Constrained
(Subtyp
)
7535 Discr
:= First_Discriminant
(Subtyp
);
7536 while Present
(Discr
) loop
7537 if Ekind
(Etype
(Discr
)) = E_Anonymous_Access_Type
then
7541 Next_Discriminant
(Discr
);
7546 end Has_Unconstrained_Access_Discriminants
;
7548 ------------------------------
7549 -- Insert_Post_Call_Actions --
7550 ------------------------------
7552 procedure Insert_Post_Call_Actions
(N
: Node_Id
; Post_Call
: List_Id
) is
7553 Context
: constant Node_Id
:= Parent
(N
);
7556 if Is_Empty_List
(Post_Call
) then
7560 -- Cases where the call is not a member of a statement list. This
7561 -- includes the case where the call is an actual in another function
7562 -- call or indexing, i.e. an expression context as well.
7564 if not Is_List_Member
(N
)
7565 or else Nkind_In
(Context
, N_Function_Call
, N_Indexed_Component
)
7567 -- In Ada 2012 the call may be a function call in an expression
7568 -- (since OUT and IN OUT parameters are now allowed for such calls).
7569 -- The write-back of (in)-out parameters is handled by the back-end,
7570 -- but the constraint checks generated when subtypes of formal and
7571 -- actual don't match must be inserted in the form of assignments.
7573 if Nkind
(Original_Node
(N
)) = N_Function_Call
then
7574 pragma Assert
(Ada_Version
>= Ada_2012
);
7575 -- Functions with '[in] out' parameters are only allowed in Ada
7578 -- We used to handle this by climbing up parents to a
7579 -- non-statement/declaration and then simply making a call to
7580 -- Insert_Actions_After (P, Post_Call), but that doesn't work
7581 -- for Ada 2012. If we are in the middle of an expression, e.g.
7582 -- the condition of an IF, this call would insert after the IF
7583 -- statement, which is much too late to be doing the write back.
7586 -- if Clobber (X) then
7587 -- Put_Line (X'Img);
7592 -- Now assume Clobber changes X, if we put the write back after
7593 -- the IF, the Put_Line gets the wrong value and the goto causes
7594 -- the write back to be skipped completely.
7596 -- To deal with this, we replace the call by
7599 -- Tnnn : constant function-result-type := function-call;
7600 -- Post_Call actions
7606 Loc
: constant Source_Ptr
:= Sloc
(N
);
7607 Tnnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
7608 FRTyp
: constant Entity_Id
:= Etype
(N
);
7609 Name
: constant Node_Id
:= Relocate_Node
(N
);
7612 Prepend_To
(Post_Call
,
7613 Make_Object_Declaration
(Loc
,
7614 Defining_Identifier
=> Tnnn
,
7615 Object_Definition
=> New_Occurrence_Of
(FRTyp
, Loc
),
7616 Constant_Present
=> True,
7617 Expression
=> Name
));
7620 Make_Expression_With_Actions
(Loc
,
7621 Actions
=> Post_Call
,
7622 Expression
=> New_Occurrence_Of
(Tnnn
, Loc
)));
7624 -- We don't want to just blindly call Analyze_And_Resolve
7625 -- because that would cause unwanted recursion on the call.
7626 -- So for a moment set the call as analyzed to prevent that
7627 -- recursion, and get the rest analyzed properly, then reset
7628 -- the analyzed flag, so our caller can continue.
7630 Set_Analyzed
(Name
, True);
7631 Analyze_And_Resolve
(N
, FRTyp
);
7632 Set_Analyzed
(Name
, False);
7635 -- If not the special Ada 2012 case of a function call, then we must
7636 -- have the triggering statement of a triggering alternative or an
7637 -- entry call alternative, and we can add the post call stuff to the
7638 -- corresponding statement list.
7641 pragma Assert
(Nkind_In
(Context
, N_Entry_Call_Alternative
,
7642 N_Triggering_Alternative
));
7644 if Is_Non_Empty_List
(Statements
(Context
)) then
7645 Insert_List_Before_And_Analyze
7646 (First
(Statements
(Context
)), Post_Call
);
7648 Set_Statements
(Context
, Post_Call
);
7652 -- A procedure call is always part of a declarative or statement list,
7653 -- however a function call may appear nested within a construct. Most
7654 -- cases of function call nesting are handled in the special case above.
7655 -- The only exception is when the function call acts as an actual in a
7656 -- procedure call. In this case the function call is in a list, but the
7657 -- post-call actions must be inserted after the procedure call.
7659 elsif Nkind
(Context
) = N_Procedure_Call_Statement
then
7660 Insert_Actions_After
(Context
, Post_Call
);
7662 -- Otherwise, normal case where N is in a statement sequence, just put
7663 -- the post-call stuff after the call statement.
7666 Insert_Actions_After
(N
, Post_Call
);
7668 end Insert_Post_Call_Actions
;
7670 -----------------------------------
7671 -- Is_Build_In_Place_Result_Type --
7672 -----------------------------------
7674 function Is_Build_In_Place_Result_Type
(Typ
: Entity_Id
) return Boolean is
7676 if not Expander_Active
then
7680 -- In Ada 2005 all functions with an inherently limited return type
7681 -- must be handled using a build-in-place profile, including the case
7682 -- of a function with a limited interface result, where the function
7683 -- may return objects of nonlimited descendants.
7685 if Is_Limited_View
(Typ
) then
7686 return Ada_Version
>= Ada_2005
and then not Debug_Flag_Dot_L
;
7689 if Debug_Flag_Dot_9
then
7693 if Has_Interfaces
(Typ
) then
7698 T
: Entity_Id
:= Typ
;
7700 -- For T'Class, return True if it's True for T. This is necessary
7701 -- because a class-wide function might say "return F (...)", where
7702 -- F returns the corresponding specific type. We need a loop in
7703 -- case T is a subtype of a class-wide type.
7705 while Is_Class_Wide_Type
(T
) loop
7709 -- If this is a generic formal type in an instance, return True if
7710 -- it's True for the generic actual type.
7712 if Nkind
(Parent
(T
)) = N_Subtype_Declaration
7713 and then Present
(Generic_Parent_Type
(Parent
(T
)))
7715 T
:= Entity
(Subtype_Indication
(Parent
(T
)));
7717 if Present
(Full_View
(T
)) then
7722 if Present
(Underlying_Type
(T
)) then
7723 T
:= Underlying_Type
(T
);
7728 -- So we can stop here in the debugger
7730 -- ???For now, enable build-in-place for a very narrow set of
7731 -- controlled types. Change "if True" to "if False" to
7732 -- experiment with more controlled types. Eventually, we might
7733 -- like to enable build-in-place for all tagged types, all
7734 -- types that need finalization, and all caller-unknown-size
7738 Result
:= Is_Controlled
(T
)
7739 and then Present
(Enclosing_Subprogram
(T
))
7740 and then not Is_Compilation_Unit
(Enclosing_Subprogram
(T
))
7741 and then Ekind
(Enclosing_Subprogram
(T
)) = E_Procedure
;
7743 Result
:= Is_Controlled
(T
);
7750 end Is_Build_In_Place_Result_Type
;
7752 --------------------------------
7753 -- Is_Build_In_Place_Function --
7754 --------------------------------
7756 function Is_Build_In_Place_Function
(E
: Entity_Id
) return Boolean is
7758 -- This function is called from Expand_Subtype_From_Expr during
7759 -- semantic analysis, even when expansion is off. In those cases
7760 -- the build_in_place expansion will not take place.
7762 if not Expander_Active
then
7766 -- For now we test whether E denotes a function or access-to-function
7767 -- type whose result subtype is inherently limited. Later this test
7768 -- may be revised to allow composite nonlimited types. Functions with
7769 -- a foreign convention or whose result type has a foreign convention
7772 if Ekind_In
(E
, E_Function
, E_Generic_Function
)
7773 or else (Ekind
(E
) = E_Subprogram_Type
7774 and then Etype
(E
) /= Standard_Void_Type
)
7776 -- Note: If the function has a foreign convention, it cannot build
7777 -- its result in place, so you're on your own. On the other hand,
7778 -- if only the return type has a foreign convention, its layout is
7779 -- intended to be compatible with the other language, but the build-
7780 -- in place machinery can ensure that the object is not copied.
7782 return Is_Build_In_Place_Result_Type
(Etype
(E
))
7783 and then not Has_Foreign_Convention
(E
)
7784 and then not Debug_Flag_Dot_L
;
7788 end Is_Build_In_Place_Function
;
7790 -------------------------------------
7791 -- Is_Build_In_Place_Function_Call --
7792 -------------------------------------
7794 function Is_Build_In_Place_Function_Call
(N
: Node_Id
) return Boolean is
7795 Exp_Node
: constant Node_Id
:= Unqual_Conv
(N
);
7796 Function_Id
: Entity_Id
;
7799 -- Return False if the expander is currently inactive, since awareness
7800 -- of build-in-place treatment is only relevant during expansion. Note
7801 -- that Is_Build_In_Place_Function, which is called as part of this
7802 -- function, is also conditioned this way, but we need to check here as
7803 -- well to avoid blowing up on processing protected calls when expansion
7804 -- is disabled (such as with -gnatc) since those would trip over the
7805 -- raise of Program_Error below.
7807 -- In SPARK mode, build-in-place calls are not expanded, so that we
7808 -- may end up with a call that is neither resolved to an entity, nor
7809 -- an indirect call.
7811 if not Expander_Active
or else Nkind
(Exp_Node
) /= N_Function_Call
then
7815 if Is_Entity_Name
(Name
(Exp_Node
)) then
7816 Function_Id
:= Entity
(Name
(Exp_Node
));
7818 -- In the case of an explicitly dereferenced call, use the subprogram
7819 -- type generated for the dereference.
7821 elsif Nkind
(Name
(Exp_Node
)) = N_Explicit_Dereference
then
7822 Function_Id
:= Etype
(Name
(Exp_Node
));
7824 -- This may be a call to a protected function.
7826 elsif Nkind
(Name
(Exp_Node
)) = N_Selected_Component
then
7827 Function_Id
:= Etype
(Entity
(Selector_Name
(Name
(Exp_Node
))));
7830 raise Program_Error
;
7834 Result
: constant Boolean := Is_Build_In_Place_Function
(Function_Id
);
7835 -- So we can stop here in the debugger
7839 end Is_Build_In_Place_Function_Call
;
7841 -----------------------
7842 -- Is_Null_Procedure --
7843 -----------------------
7845 function Is_Null_Procedure
(Subp
: Entity_Id
) return Boolean is
7846 Decl
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
7849 if Ekind
(Subp
) /= E_Procedure
then
7852 -- Check if this is a declared null procedure
7854 elsif Nkind
(Decl
) = N_Subprogram_Declaration
then
7855 if not Null_Present
(Specification
(Decl
)) then
7858 elsif No
(Body_To_Inline
(Decl
)) then
7861 -- Check if the body contains only a null statement, followed by
7862 -- the return statement added during expansion.
7866 Orig_Bod
: constant Node_Id
:= Body_To_Inline
(Decl
);
7872 if Nkind
(Orig_Bod
) /= N_Subprogram_Body
then
7875 -- We must skip SCIL nodes because they are currently
7876 -- implemented as special N_Null_Statement nodes.
7880 (Statements
(Handled_Statement_Sequence
(Orig_Bod
)));
7881 Stat2
:= Next_Non_SCIL_Node
(Stat
);
7884 Is_Empty_List
(Declarations
(Orig_Bod
))
7885 and then Nkind
(Stat
) = N_Null_Statement
7889 (Nkind
(Stat2
) = N_Simple_Return_Statement
7890 and then No
(Next
(Stat2
))));
7898 end Is_Null_Procedure
;
7900 -------------------------------------------
7901 -- Make_Build_In_Place_Call_In_Allocator --
7902 -------------------------------------------
7904 procedure Make_Build_In_Place_Call_In_Allocator
7905 (Allocator
: Node_Id
;
7906 Function_Call
: Node_Id
)
7908 Acc_Type
: constant Entity_Id
:= Etype
(Allocator
);
7909 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
7910 Func_Call
: Node_Id
:= Function_Call
;
7911 Ref_Func_Call
: Node_Id
;
7912 Function_Id
: Entity_Id
;
7913 Result_Subt
: Entity_Id
;
7914 New_Allocator
: Node_Id
;
7915 Return_Obj_Access
: Entity_Id
; -- temp for function result
7916 Temp_Init
: Node_Id
; -- initial value of Return_Obj_Access
7917 Alloc_Form
: BIP_Allocation_Form
;
7918 Pool
: Node_Id
; -- nonnull if Alloc_Form = User_Storage_Pool
7919 Return_Obj_Actual
: Node_Id
; -- the temp.all, in caller-allocates case
7920 Chain
: Entity_Id
; -- activation chain, in case of tasks
7923 -- Step past qualification or unchecked conversion (the latter can occur
7924 -- in cases of calls to 'Input).
7926 if Nkind_In
(Func_Call
, N_Qualified_Expression
,
7928 N_Unchecked_Type_Conversion
)
7930 Func_Call
:= Expression
(Func_Call
);
7933 -- Mark the call as processed as a build-in-place call
7935 pragma Assert
(not Is_Expanded_Build_In_Place_Call
(Func_Call
));
7936 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
7938 if Is_Entity_Name
(Name
(Func_Call
)) then
7939 Function_Id
:= Entity
(Name
(Func_Call
));
7941 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
7942 Function_Id
:= Etype
(Name
(Func_Call
));
7945 raise Program_Error
;
7948 Result_Subt
:= Available_View
(Etype
(Function_Id
));
7950 -- Create a temp for the function result. In the caller-allocates case,
7951 -- this will be initialized to the result of a new uninitialized
7952 -- allocator. Note: we do not use Allocator as the Related_Node of
7953 -- Return_Obj_Access in call to Make_Temporary below as this would
7954 -- create a sort of infinite "recursion".
7956 Return_Obj_Access
:= Make_Temporary
(Loc
, 'R');
7957 Set_Etype
(Return_Obj_Access
, Acc_Type
);
7958 Set_Can_Never_Be_Null
(Acc_Type
, False);
7959 -- It gets initialized to null, so we can't have that
7961 -- When the result subtype is constrained, the return object is created
7962 -- on the caller side, and access to it is passed to the function. This
7963 -- optimization is disabled when the result subtype needs finalization
7964 -- actions because the caller side allocation may result in undesirable
7965 -- finalization. Consider the following example:
7967 -- function Make_Lim_Ctrl return Lim_Ctrl is
7969 -- return Result : Lim_Ctrl := raise Program_Error do
7972 -- end Make_Lim_Ctrl;
7974 -- Obj : Lim_Ctrl_Ptr := new Lim_Ctrl'(Make_Lim_Ctrl);
7976 -- Even though the size of limited controlled type Lim_Ctrl is known,
7977 -- allocating Obj at the caller side will chain Obj on Lim_Ctrl_Ptr's
7978 -- finalization master. The subsequent call to Make_Lim_Ctrl will fail
7979 -- during the initialization actions for Result, which implies that
7980 -- Result (and Obj by extension) should not be finalized. However Obj
7981 -- will be finalized when access type Lim_Ctrl_Ptr goes out of scope
7982 -- since it is already attached on the related finalization master.
7984 -- Here and in related routines, we must examine the full view of the
7985 -- type, because the view at the point of call may differ from that
7986 -- that in the function body, and the expansion mechanism depends on
7987 -- the characteristics of the full view.
7989 if Is_Constrained
(Underlying_Type
(Result_Subt
))
7990 and then not Needs_Finalization
(Underlying_Type
(Result_Subt
))
7992 -- Replace the initialized allocator of form "new T'(Func (...))"
7993 -- with an uninitialized allocator of form "new T", where T is the
7994 -- result subtype of the called function. The call to the function
7995 -- is handled separately further below.
7998 Make_Allocator
(Loc
,
7999 Expression
=> New_Occurrence_Of
(Result_Subt
, Loc
));
8000 Set_No_Initialization
(New_Allocator
);
8002 -- Copy attributes to new allocator. Note that the new allocator
8003 -- logically comes from source if the original one did, so copy the
8004 -- relevant flag. This ensures proper treatment of the restriction
8005 -- No_Implicit_Heap_Allocations in this case.
8007 Set_Storage_Pool
(New_Allocator
, Storage_Pool
(Allocator
));
8008 Set_Procedure_To_Call
(New_Allocator
, Procedure_To_Call
(Allocator
));
8009 Set_Comes_From_Source
(New_Allocator
, Comes_From_Source
(Allocator
));
8011 Rewrite
(Allocator
, New_Allocator
);
8013 -- Initial value of the temp is the result of the uninitialized
8014 -- allocator. Unchecked_Convert is needed for T'Input where T is
8015 -- derived from a controlled type.
8017 Temp_Init
:= Relocate_Node
(Allocator
);
8019 if Nkind_In
(Function_Call
, N_Type_Conversion
,
8020 N_Unchecked_Type_Conversion
)
8022 Temp_Init
:= Unchecked_Convert_To
(Acc_Type
, Temp_Init
);
8025 -- Indicate that caller allocates, and pass in the return object
8027 Alloc_Form
:= Caller_Allocation
;
8028 Pool
:= Make_Null
(No_Location
);
8029 Return_Obj_Actual
:=
8030 Make_Unchecked_Type_Conversion
(Loc
,
8031 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
8033 Make_Explicit_Dereference
(Loc
,
8034 Prefix
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
)));
8036 -- When the result subtype is unconstrained, the function itself must
8037 -- perform the allocation of the return object, so we pass parameters
8043 -- Case of a user-defined storage pool. Pass an allocation parameter
8044 -- indicating that the function should allocate its result in the
8045 -- pool, and pass the pool. Use 'Unrestricted_Access because the
8046 -- pool may not be aliased.
8048 if Present
(Associated_Storage_Pool
(Acc_Type
)) then
8049 Alloc_Form
:= User_Storage_Pool
;
8051 Make_Attribute_Reference
(Loc
,
8054 (Associated_Storage_Pool
(Acc_Type
), Loc
),
8055 Attribute_Name
=> Name_Unrestricted_Access
);
8057 -- No user-defined pool; pass an allocation parameter indicating that
8058 -- the function should allocate its result on the heap.
8061 Alloc_Form
:= Global_Heap
;
8062 Pool
:= Make_Null
(No_Location
);
8065 -- The caller does not provide the return object in this case, so we
8066 -- have to pass null for the object access actual.
8068 Return_Obj_Actual
:= Empty
;
8071 -- Declare the temp object
8073 Insert_Action
(Allocator
,
8074 Make_Object_Declaration
(Loc
,
8075 Defining_Identifier
=> Return_Obj_Access
,
8076 Object_Definition
=> New_Occurrence_Of
(Acc_Type
, Loc
),
8077 Expression
=> Temp_Init
));
8079 Ref_Func_Call
:= Make_Reference
(Loc
, Func_Call
);
8081 -- Ada 2005 (AI-251): If the type of the allocator is an interface
8082 -- then generate an implicit conversion to force displacement of the
8085 if Is_Interface
(Designated_Type
(Acc_Type
)) then
8088 OK_Convert_To
(Acc_Type
, Ref_Func_Call
));
8090 -- If the types are incompatible, we need an unchecked conversion. Note
8091 -- that the full types will be compatible, but the types not visibly
8094 elsif Nkind_In
(Function_Call
, N_Type_Conversion
,
8095 N_Unchecked_Type_Conversion
)
8097 Ref_Func_Call
:= Unchecked_Convert_To
(Acc_Type
, Ref_Func_Call
);
8101 Assign
: constant Node_Id
:=
8102 Make_Assignment_Statement
(Loc
,
8103 Name
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
),
8104 Expression
=> Ref_Func_Call
);
8105 -- Assign the result of the function call into the temp. In the
8106 -- caller-allocates case, this is overwriting the temp with its
8107 -- initial value, which has no effect. In the callee-allocates case,
8108 -- this is setting the temp to point to the object allocated by the
8109 -- callee. Unchecked_Convert is needed for T'Input where T is derived
8110 -- from a controlled type.
8113 -- Actions to be inserted. If there are no tasks, this is just the
8114 -- assignment statement. If the allocated object has tasks, we need
8115 -- to wrap the assignment in a block that activates them. The
8116 -- activation chain of that block must be passed to the function,
8117 -- rather than some outer chain.
8120 if Has_Task
(Result_Subt
) then
8121 Actions
:= New_List
;
8122 Build_Task_Allocate_Block_With_Init_Stmts
8123 (Actions
, Allocator
, Init_Stmts
=> New_List
(Assign
));
8124 Chain
:= Activation_Chain_Entity
(Last
(Actions
));
8126 Actions
:= New_List
(Assign
);
8130 Insert_Actions
(Allocator
, Actions
);
8133 -- When the function has a controlling result, an allocation-form
8134 -- parameter must be passed indicating that the caller is allocating
8135 -- the result object. This is needed because such a function can be
8136 -- called as a dispatching operation and must be treated similarly
8137 -- to functions with unconstrained result subtypes.
8139 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8140 (Func_Call
, Function_Id
, Alloc_Form
, Pool_Actual
=> Pool
);
8142 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8143 (Func_Call
, Function_Id
, Acc_Type
);
8145 Add_Task_Actuals_To_Build_In_Place_Call
8146 (Func_Call
, Function_Id
, Master_Actual
=> Master_Id
(Acc_Type
),
8149 -- Add an implicit actual to the function call that provides access
8150 -- to the allocated object. An unchecked conversion to the (specific)
8151 -- result subtype of the function is inserted to handle cases where
8152 -- the access type of the allocator has a class-wide designated type.
8154 Add_Access_Actual_To_Build_In_Place_Call
8155 (Func_Call
, Function_Id
, Return_Obj_Actual
);
8157 -- Finally, replace the allocator node with a reference to the temp
8159 Rewrite
(Allocator
, New_Occurrence_Of
(Return_Obj_Access
, Loc
));
8161 Analyze_And_Resolve
(Allocator
, Acc_Type
);
8162 end Make_Build_In_Place_Call_In_Allocator
;
8164 ---------------------------------------------------
8165 -- Make_Build_In_Place_Call_In_Anonymous_Context --
8166 ---------------------------------------------------
8168 procedure Make_Build_In_Place_Call_In_Anonymous_Context
8169 (Function_Call
: Node_Id
)
8171 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8172 Func_Call
: constant Node_Id
:= Unqual_Conv
(Function_Call
);
8173 Function_Id
: Entity_Id
;
8174 Result_Subt
: Entity_Id
;
8175 Return_Obj_Id
: Entity_Id
;
8176 Return_Obj_Decl
: Entity_Id
;
8179 -- If the call has already been processed to add build-in-place actuals
8180 -- then return. One place this can occur is for calls to build-in-place
8181 -- functions that occur within a call to a protected operation, where
8182 -- due to rewriting and expansion of the protected call there can be
8183 -- more than one call to Expand_Actuals for the same set of actuals.
8185 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
8189 -- Mark the call as processed as a build-in-place call
8191 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
8193 if Is_Entity_Name
(Name
(Func_Call
)) then
8194 Function_Id
:= Entity
(Name
(Func_Call
));
8196 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
8197 Function_Id
:= Etype
(Name
(Func_Call
));
8200 raise Program_Error
;
8203 Result_Subt
:= Etype
(Function_Id
);
8205 -- If the build-in-place function returns a controlled object, then the
8206 -- object needs to be finalized immediately after the context. Since
8207 -- this case produces a transient scope, the servicing finalizer needs
8208 -- to name the returned object. Create a temporary which is initialized
8209 -- with the function call:
8211 -- Temp_Id : Func_Type := BIP_Func_Call;
8213 -- The initialization expression of the temporary will be rewritten by
8214 -- the expander using the appropriate mechanism in Make_Build_In_Place_
8215 -- Call_In_Object_Declaration.
8217 if Needs_Finalization
(Result_Subt
) then
8219 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'R');
8220 Temp_Decl
: Node_Id
;
8223 -- Reset the guard on the function call since the following does
8224 -- not perform actual call expansion.
8226 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
, False);
8229 Make_Object_Declaration
(Loc
,
8230 Defining_Identifier
=> Temp_Id
,
8231 Object_Definition
=>
8232 New_Occurrence_Of
(Result_Subt
, Loc
),
8234 New_Copy_Tree
(Function_Call
));
8236 Insert_Action
(Function_Call
, Temp_Decl
);
8238 Rewrite
(Function_Call
, New_Occurrence_Of
(Temp_Id
, Loc
));
8239 Analyze
(Function_Call
);
8242 -- When the result subtype is definite, an object of the subtype is
8243 -- declared and an access value designating it is passed as an actual.
8245 elsif Caller_Known_Size
(Func_Call
, Result_Subt
) then
8247 -- Create a temporary object to hold the function result
8249 Return_Obj_Id
:= Make_Temporary
(Loc
, 'R');
8250 Set_Etype
(Return_Obj_Id
, Result_Subt
);
8253 Make_Object_Declaration
(Loc
,
8254 Defining_Identifier
=> Return_Obj_Id
,
8255 Aliased_Present
=> True,
8256 Object_Definition
=> New_Occurrence_Of
(Result_Subt
, Loc
));
8258 Set_No_Initialization
(Return_Obj_Decl
);
8260 Insert_Action
(Func_Call
, Return_Obj_Decl
);
8262 -- When the function has a controlling result, an allocation-form
8263 -- parameter must be passed indicating that the caller is allocating
8264 -- the result object. This is needed because such a function can be
8265 -- called as a dispatching operation and must be treated similarly
8266 -- to functions with unconstrained result subtypes.
8268 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8269 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8271 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8272 (Func_Call
, Function_Id
);
8274 Add_Task_Actuals_To_Build_In_Place_Call
8275 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8277 -- Add an implicit actual to the function call that provides access
8278 -- to the caller's return object.
8280 Add_Access_Actual_To_Build_In_Place_Call
8281 (Func_Call
, Function_Id
, New_Occurrence_Of
(Return_Obj_Id
, Loc
));
8283 -- When the result subtype is unconstrained, the function must allocate
8284 -- the return object in the secondary stack, so appropriate implicit
8285 -- parameters are added to the call to indicate that. A transient
8286 -- scope is established to ensure eventual cleanup of the result.
8289 -- Pass an allocation parameter indicating that the function should
8290 -- allocate its result on the secondary stack.
8292 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8293 (Func_Call
, Function_Id
, Alloc_Form
=> Secondary_Stack
);
8295 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8296 (Func_Call
, Function_Id
);
8298 Add_Task_Actuals_To_Build_In_Place_Call
8299 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8301 -- Pass a null value to the function since no return object is
8302 -- available on the caller side.
8304 Add_Access_Actual_To_Build_In_Place_Call
8305 (Func_Call
, Function_Id
, Empty
);
8307 end Make_Build_In_Place_Call_In_Anonymous_Context
;
8309 --------------------------------------------
8310 -- Make_Build_In_Place_Call_In_Assignment --
8311 --------------------------------------------
8313 procedure Make_Build_In_Place_Call_In_Assignment
8315 Function_Call
: Node_Id
)
8317 Func_Call
: constant Node_Id
:= Unqual_Conv
(Function_Call
);
8318 Lhs
: constant Node_Id
:= Name
(Assign
);
8319 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8320 Func_Id
: Entity_Id
;
8323 Ptr_Typ
: Entity_Id
;
8324 Ptr_Typ_Decl
: Node_Id
;
8326 Result_Subt
: Entity_Id
;
8329 -- Mark the call as processed as a build-in-place call
8331 pragma Assert
(not Is_Expanded_Build_In_Place_Call
(Func_Call
));
8332 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
8334 if Is_Entity_Name
(Name
(Func_Call
)) then
8335 Func_Id
:= Entity
(Name
(Func_Call
));
8337 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
8338 Func_Id
:= Etype
(Name
(Func_Call
));
8341 raise Program_Error
;
8344 Result_Subt
:= Etype
(Func_Id
);
8346 -- When the result subtype is unconstrained, an additional actual must
8347 -- be passed to indicate that the caller is providing the return object.
8348 -- This parameter must also be passed when the called function has a
8349 -- controlling result, because dispatching calls to the function needs
8350 -- to be treated effectively the same as calls to class-wide functions.
8352 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8353 (Func_Call
, Func_Id
, Alloc_Form
=> Caller_Allocation
);
8355 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8356 (Func_Call
, Func_Id
);
8358 Add_Task_Actuals_To_Build_In_Place_Call
8359 (Func_Call
, Func_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8361 -- Add an implicit actual to the function call that provides access to
8362 -- the caller's return object.
8364 Add_Access_Actual_To_Build_In_Place_Call
8367 Make_Unchecked_Type_Conversion
(Loc
,
8368 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
8369 Expression
=> Relocate_Node
(Lhs
)));
8371 -- Create an access type designating the function's result subtype
8373 Ptr_Typ
:= Make_Temporary
(Loc
, 'A');
8376 Make_Full_Type_Declaration
(Loc
,
8377 Defining_Identifier
=> Ptr_Typ
,
8379 Make_Access_To_Object_Definition
(Loc
,
8380 All_Present
=> True,
8381 Subtype_Indication
=>
8382 New_Occurrence_Of
(Result_Subt
, Loc
)));
8383 Insert_After_And_Analyze
(Assign
, Ptr_Typ_Decl
);
8385 -- Finally, create an access object initialized to a reference to the
8386 -- function call. We know this access value is non-null, so mark the
8387 -- entity accordingly to suppress junk access checks.
8389 New_Expr
:= Make_Reference
(Loc
, Relocate_Node
(Func_Call
));
8391 -- Add a conversion if it's the wrong type
8393 if Etype
(New_Expr
) /= Ptr_Typ
then
8395 Make_Unchecked_Type_Conversion
(Loc
,
8396 New_Occurrence_Of
(Ptr_Typ
, Loc
), New_Expr
);
8399 Obj_Id
:= Make_Temporary
(Loc
, 'R', New_Expr
);
8400 Set_Etype
(Obj_Id
, Ptr_Typ
);
8401 Set_Is_Known_Non_Null
(Obj_Id
);
8404 Make_Object_Declaration
(Loc
,
8405 Defining_Identifier
=> Obj_Id
,
8406 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8407 Expression
=> New_Expr
);
8408 Insert_After_And_Analyze
(Ptr_Typ_Decl
, Obj_Decl
);
8410 Rewrite
(Assign
, Make_Null_Statement
(Loc
));
8411 end Make_Build_In_Place_Call_In_Assignment
;
8413 ----------------------------------------------------
8414 -- Make_Build_In_Place_Call_In_Object_Declaration --
8415 ----------------------------------------------------
8417 procedure Make_Build_In_Place_Call_In_Object_Declaration
8418 (Obj_Decl
: Node_Id
;
8419 Function_Call
: Node_Id
)
8421 function Get_Function_Id
(Func_Call
: Node_Id
) return Entity_Id
;
8422 -- Get the value of Function_Id, below
8424 ---------------------
8425 -- Get_Function_Id --
8426 ---------------------
8428 function Get_Function_Id
(Func_Call
: Node_Id
) return Entity_Id
is
8430 if Is_Entity_Name
(Name
(Func_Call
)) then
8431 return Entity
(Name
(Func_Call
));
8433 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
8434 return Etype
(Name
(Func_Call
));
8437 raise Program_Error
;
8439 end Get_Function_Id
;
8443 Func_Call
: constant Node_Id
:= Unqual_Conv
(Function_Call
);
8444 Function_Id
: constant Entity_Id
:= Get_Function_Id
(Func_Call
);
8445 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8446 Obj_Loc
: constant Source_Ptr
:= Sloc
(Obj_Decl
);
8447 Obj_Def_Id
: constant Entity_Id
:= Defining_Identifier
(Obj_Decl
);
8448 Obj_Typ
: constant Entity_Id
:= Etype
(Obj_Def_Id
);
8449 Encl_Func
: constant Entity_Id
:= Enclosing_Subprogram
(Obj_Def_Id
);
8450 Result_Subt
: constant Entity_Id
:= Etype
(Function_Id
);
8452 Call_Deref
: Node_Id
;
8453 Caller_Object
: Node_Id
;
8455 Designated_Type
: Entity_Id
;
8456 Fmaster_Actual
: Node_Id
:= Empty
;
8457 Pool_Actual
: Node_Id
;
8458 Ptr_Typ
: Entity_Id
;
8459 Ptr_Typ_Decl
: Node_Id
;
8460 Pass_Caller_Acc
: Boolean := False;
8463 Definite
: constant Boolean :=
8464 Caller_Known_Size
(Func_Call
, Result_Subt
)
8465 and then not Is_Class_Wide_Type
(Obj_Typ
);
8466 -- In the case of "X : T'Class := F(...);", where F returns a
8467 -- Caller_Known_Size (specific) tagged type, we treat it as
8468 -- indefinite, because the code for the Definite case below sets the
8469 -- initialization expression of the object to Empty, which would be
8470 -- illegal Ada, and would cause gigi to misallocate X.
8472 -- Start of processing for Make_Build_In_Place_Call_In_Object_Declaration
8475 -- If the call has already been processed to add build-in-place actuals
8478 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
8482 -- Mark the call as processed as a build-in-place call
8484 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
8486 -- Create an access type designating the function's result subtype.
8487 -- We use the type of the original call because it may be a call to an
8488 -- inherited operation, which the expansion has replaced with the parent
8489 -- operation that yields the parent type. Note that this access type
8490 -- must be declared before we establish a transient scope, so that it
8491 -- receives the proper accessibility level.
8493 if Is_Class_Wide_Type
(Obj_Typ
)
8494 and then not Is_Interface
(Obj_Typ
)
8495 and then not Is_Class_Wide_Type
(Etype
(Function_Call
))
8497 Designated_Type
:= Obj_Typ
;
8499 Designated_Type
:= Etype
(Function_Call
);
8502 Ptr_Typ
:= Make_Temporary
(Loc
, 'A');
8504 Make_Full_Type_Declaration
(Loc
,
8505 Defining_Identifier
=> Ptr_Typ
,
8507 Make_Access_To_Object_Definition
(Loc
,
8508 All_Present
=> True,
8509 Subtype_Indication
=>
8510 New_Occurrence_Of
(Designated_Type
, Loc
)));
8512 -- The access type and its accompanying object must be inserted after
8513 -- the object declaration in the constrained case, so that the function
8514 -- call can be passed access to the object. In the indefinite case, or
8515 -- if the object declaration is for a return object, the access type and
8516 -- object must be inserted before the object, since the object
8517 -- declaration is rewritten to be a renaming of a dereference of the
8518 -- access object. Note: we need to freeze Ptr_Typ explicitly, because
8519 -- the result object is in a different (transient) scope, so won't cause
8522 if Definite
and then not Is_Return_Object
(Obj_Def_Id
) then
8524 -- The presence of an address clause complicates the build-in-place
8525 -- expansion because the indicated address must be processed before
8526 -- the indirect call is generated (including the definition of a
8527 -- local pointer to the object). The address clause may come from
8528 -- an aspect specification or from an explicit attribute
8529 -- specification appearing after the object declaration. These two
8530 -- cases require different processing.
8532 if Has_Aspect
(Obj_Def_Id
, Aspect_Address
) then
8534 -- Skip non-delayed pragmas that correspond to other aspects, if
8535 -- any, to find proper insertion point for freeze node of object.
8538 D
: Node_Id
:= Obj_Decl
;
8539 N
: Node_Id
:= Next
(D
);
8543 and then Nkind_In
(N
, N_Attribute_Reference
, N_Pragma
)
8550 Insert_After
(D
, Ptr_Typ_Decl
);
8552 -- Freeze object before pointer declaration, to ensure that
8553 -- generated attribute for address is inserted at the proper
8556 Freeze_Before
(Ptr_Typ_Decl
, Obj_Def_Id
);
8559 Analyze
(Ptr_Typ_Decl
);
8561 elsif Present
(Following_Address_Clause
(Obj_Decl
)) then
8563 -- Locate explicit address clause, which may also follow pragmas
8564 -- generated by other aspect specifications.
8567 Addr
: constant Node_Id
:= Following_Address_Clause
(Obj_Decl
);
8568 D
: Node_Id
:= Next
(Obj_Decl
);
8571 while Present
(D
) loop
8577 Insert_After_And_Analyze
(Addr
, Ptr_Typ_Decl
);
8581 Insert_After_And_Analyze
(Obj_Decl
, Ptr_Typ_Decl
);
8584 Insert_Action
(Obj_Decl
, Ptr_Typ_Decl
);
8587 -- Force immediate freezing of Ptr_Typ because Res_Decl will be
8588 -- elaborated in an inner (transient) scope and thus won't cause
8589 -- freezing by itself. It's not an itype, but it needs to be frozen
8590 -- inside the current subprogram (see Freeze_Outside in freeze.adb).
8592 Freeze_Itype
(Ptr_Typ
, Ptr_Typ_Decl
);
8594 -- If the object is a return object of an enclosing build-in-place
8595 -- function, then the implicit build-in-place parameters of the
8596 -- enclosing function are simply passed along to the called function.
8597 -- (Unfortunately, this won't cover the case of extension aggregates
8598 -- where the ancestor part is a build-in-place indefinite function
8599 -- call that should be passed along the caller's parameters.
8600 -- Currently those get mishandled by reassigning the result of the
8601 -- call to the aggregate return object, when the call result should
8602 -- really be directly built in place in the aggregate and not in a
8605 if Is_Return_Object
(Obj_Def_Id
) then
8606 Pass_Caller_Acc
:= True;
8608 -- When the enclosing function has a BIP_Alloc_Form formal then we
8609 -- pass it along to the callee (such as when the enclosing function
8610 -- has an unconstrained or tagged result type).
8612 if Needs_BIP_Alloc_Form
(Encl_Func
) then
8613 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
8616 (Build_In_Place_Formal
8617 (Encl_Func
, BIP_Storage_Pool
), Loc
);
8619 -- The build-in-place pool formal is not built on e.g. ZFP
8622 Pool_Actual
:= Empty
;
8625 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8626 (Function_Call
=> Func_Call
,
8627 Function_Id
=> Function_Id
,
8630 (Build_In_Place_Formal
(Encl_Func
, BIP_Alloc_Form
), Loc
),
8631 Pool_Actual
=> Pool_Actual
);
8633 -- Otherwise, if enclosing function has a definite result subtype,
8634 -- then caller allocation will be used.
8637 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8638 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8641 if Needs_BIP_Finalization_Master
(Encl_Func
) then
8644 (Build_In_Place_Formal
8645 (Encl_Func
, BIP_Finalization_Master
), Loc
);
8648 -- Retrieve the BIPacc formal from the enclosing function and convert
8649 -- it to the access type of the callee's BIP_Object_Access formal.
8652 Make_Unchecked_Type_Conversion
(Loc
,
8655 (Etype
(Build_In_Place_Formal
8656 (Function_Id
, BIP_Object_Access
)),
8660 (Build_In_Place_Formal
(Encl_Func
, BIP_Object_Access
),
8663 -- In the definite case, add an implicit actual to the function call
8664 -- that provides access to the declared object. An unchecked conversion
8665 -- to the (specific) result type of the function is inserted to handle
8666 -- the case where the object is declared with a class-wide type.
8670 Make_Unchecked_Type_Conversion
(Loc
,
8671 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
8672 Expression
=> New_Occurrence_Of
(Obj_Def_Id
, Loc
));
8674 -- When the function has a controlling result, an allocation-form
8675 -- parameter must be passed indicating that the caller is allocating
8676 -- the result object. This is needed because such a function can be
8677 -- called as a dispatching operation and must be treated similarly to
8678 -- functions with indefinite result subtypes.
8680 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8681 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8683 -- The allocation for indefinite library-level objects occurs on the
8684 -- heap as opposed to the secondary stack. This accommodates DLLs where
8685 -- the secondary stack is destroyed after each library unload. This is a
8686 -- hybrid mechanism where a stack-allocated object lives on the heap.
8688 elsif Is_Library_Level_Entity
(Obj_Def_Id
)
8689 and then not Restriction_Active
(No_Implicit_Heap_Allocations
)
8691 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8692 (Func_Call
, Function_Id
, Alloc_Form
=> Global_Heap
);
8693 Caller_Object
:= Empty
;
8695 -- Create a finalization master for the access result type to ensure
8696 -- that the heap allocation can properly chain the object and later
8697 -- finalize it when the library unit goes out of scope.
8699 if Needs_Finalization
(Etype
(Func_Call
)) then
8700 Build_Finalization_Master
8702 For_Lib_Level
=> True,
8703 Insertion_Node
=> Ptr_Typ_Decl
);
8706 Make_Attribute_Reference
(Loc
,
8708 New_Occurrence_Of
(Finalization_Master
(Ptr_Typ
), Loc
),
8709 Attribute_Name
=> Name_Unrestricted_Access
);
8712 -- In other indefinite cases, pass an indication to do the allocation
8713 -- on the secondary stack and set Caller_Object to Empty so that a null
8714 -- value will be passed for the caller's object address. A transient
8715 -- scope is established to ensure eventual cleanup of the result.
8718 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8719 (Func_Call
, Function_Id
, Alloc_Form
=> Secondary_Stack
);
8720 Caller_Object
:= Empty
;
8722 Establish_Transient_Scope
(Obj_Decl
, Manage_Sec_Stack
=> True);
8725 -- Pass along any finalization master actual, which is needed in the
8726 -- case where the called function initializes a return object of an
8727 -- enclosing build-in-place function.
8729 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8730 (Func_Call
=> Func_Call
,
8731 Func_Id
=> Function_Id
,
8732 Master_Exp
=> Fmaster_Actual
);
8734 if Nkind
(Parent
(Obj_Decl
)) = N_Extended_Return_Statement
8735 and then Has_Task
(Result_Subt
)
8737 -- Here we're passing along the master that was passed in to this
8740 Add_Task_Actuals_To_Build_In_Place_Call
8741 (Func_Call
, Function_Id
,
8744 (Build_In_Place_Formal
(Encl_Func
, BIP_Task_Master
), Loc
));
8747 Add_Task_Actuals_To_Build_In_Place_Call
8748 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8751 Add_Access_Actual_To_Build_In_Place_Call
8755 Is_Access
=> Pass_Caller_Acc
);
8757 -- Finally, create an access object initialized to a reference to the
8758 -- function call. We know this access value cannot be null, so mark the
8759 -- entity accordingly to suppress the access check.
8761 Def_Id
:= Make_Temporary
(Loc
, 'R', Func_Call
);
8762 Set_Etype
(Def_Id
, Ptr_Typ
);
8763 Set_Is_Known_Non_Null
(Def_Id
);
8765 if Nkind_In
(Function_Call
, N_Type_Conversion
,
8766 N_Unchecked_Type_Conversion
)
8769 Make_Object_Declaration
(Loc
,
8770 Defining_Identifier
=> Def_Id
,
8771 Constant_Present
=> True,
8772 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8774 Make_Unchecked_Type_Conversion
(Loc
,
8775 New_Occurrence_Of
(Ptr_Typ
, Loc
),
8776 Make_Reference
(Loc
, Relocate_Node
(Func_Call
))));
8779 Make_Object_Declaration
(Loc
,
8780 Defining_Identifier
=> Def_Id
,
8781 Constant_Present
=> True,
8782 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8784 Make_Reference
(Loc
, Relocate_Node
(Func_Call
)));
8787 Insert_After_And_Analyze
(Ptr_Typ_Decl
, Res_Decl
);
8789 -- If the result subtype of the called function is definite and is not
8790 -- itself the return expression of an enclosing BIP function, then mark
8791 -- the object as having no initialization.
8793 if Definite
and then not Is_Return_Object
(Obj_Def_Id
) then
8795 -- The related object declaration is encased in a transient block
8796 -- because the build-in-place function call contains at least one
8797 -- nested function call that produces a controlled transient
8800 -- Obj : ... := BIP_Func_Call (Ctrl_Func_Call);
8802 -- Since the build-in-place expansion decouples the call from the
8803 -- object declaration, the finalization machinery lacks the context
8804 -- which prompted the generation of the transient block. To resolve
8805 -- this scenario, store the build-in-place call.
8807 if Scope_Is_Transient
and then Node_To_Be_Wrapped
= Obj_Decl
then
8808 Set_BIP_Initialization_Call
(Obj_Def_Id
, Res_Decl
);
8811 Set_Expression
(Obj_Decl
, Empty
);
8812 Set_No_Initialization
(Obj_Decl
);
8814 -- In case of an indefinite result subtype, or if the call is the
8815 -- return expression of an enclosing BIP function, rewrite the object
8816 -- declaration as an object renaming where the renamed object is a
8817 -- dereference of <function_Call>'reference:
8819 -- Obj : Subt renames <function_call>'Ref.all;
8823 Make_Explicit_Dereference
(Obj_Loc
,
8824 Prefix
=> New_Occurrence_Of
(Def_Id
, Obj_Loc
));
8827 Make_Object_Renaming_Declaration
(Obj_Loc
,
8828 Defining_Identifier
=> Make_Temporary
(Obj_Loc
, 'D'),
8830 New_Occurrence_Of
(Designated_Type
, Obj_Loc
),
8831 Name
=> Call_Deref
));
8833 -- At this point, Defining_Identifier (Obj_Decl) is no longer equal
8836 Set_Renamed_Object
(Defining_Identifier
(Obj_Decl
), Call_Deref
);
8838 -- If the original entity comes from source, then mark the new
8839 -- entity as needing debug information, even though it's defined
8840 -- by a generated renaming that does not come from source, so that
8841 -- the Materialize_Entity flag will be set on the entity when
8842 -- Debug_Renaming_Declaration is called during analysis.
8844 if Comes_From_Source
(Obj_Def_Id
) then
8845 Set_Debug_Info_Needed
(Defining_Identifier
(Obj_Decl
));
8849 Replace_Renaming_Declaration_Id
8850 (Obj_Decl
, Original_Node
(Obj_Decl
));
8852 end Make_Build_In_Place_Call_In_Object_Declaration
;
8854 -------------------------------------------------
8855 -- Make_Build_In_Place_Iface_Call_In_Allocator --
8856 -------------------------------------------------
8858 procedure Make_Build_In_Place_Iface_Call_In_Allocator
8859 (Allocator
: Node_Id
;
8860 Function_Call
: Node_Id
)
8862 BIP_Func_Call
: constant Node_Id
:=
8863 Unqual_BIP_Iface_Function_Call
(Function_Call
);
8864 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8866 Anon_Type
: Entity_Id
;
8871 -- No action of the call has already been processed
8873 if Is_Expanded_Build_In_Place_Call
(BIP_Func_Call
) then
8877 Tmp_Id
:= Make_Temporary
(Loc
, 'D');
8879 -- Insert a temporary before N initialized with the BIP function call
8880 -- without its enclosing type conversions and analyze it without its
8881 -- expansion. This temporary facilitates us reusing the BIP machinery,
8882 -- which takes care of adding the extra build-in-place actuals and
8883 -- transforms this object declaration into an object renaming
8886 Anon_Type
:= Create_Itype
(E_Anonymous_Access_Type
, Function_Call
);
8887 Set_Directly_Designated_Type
(Anon_Type
, Etype
(BIP_Func_Call
));
8888 Set_Etype
(Anon_Type
, Anon_Type
);
8891 Make_Object_Declaration
(Loc
,
8892 Defining_Identifier
=> Tmp_Id
,
8893 Object_Definition
=> New_Occurrence_Of
(Anon_Type
, Loc
),
8895 Make_Allocator
(Loc
,
8897 Make_Qualified_Expression
(Loc
,
8899 New_Occurrence_Of
(Etype
(BIP_Func_Call
), Loc
),
8900 Expression
=> New_Copy_Tree
(BIP_Func_Call
))));
8902 Expander_Mode_Save_And_Set
(False);
8903 Insert_Action
(Allocator
, Tmp_Decl
);
8904 Expander_Mode_Restore
;
8906 Make_Build_In_Place_Call_In_Allocator
8907 (Allocator
=> Expression
(Tmp_Decl
),
8908 Function_Call
=> Expression
(Expression
(Tmp_Decl
)));
8910 Rewrite
(Allocator
, New_Occurrence_Of
(Tmp_Id
, Loc
));
8911 end Make_Build_In_Place_Iface_Call_In_Allocator
;
8913 ---------------------------------------------------------
8914 -- Make_Build_In_Place_Iface_Call_In_Anonymous_Context --
8915 ---------------------------------------------------------
8917 procedure Make_Build_In_Place_Iface_Call_In_Anonymous_Context
8918 (Function_Call
: Node_Id
)
8920 BIP_Func_Call
: constant Node_Id
:=
8921 Unqual_BIP_Iface_Function_Call
(Function_Call
);
8922 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8928 -- No action of the call has already been processed
8930 if Is_Expanded_Build_In_Place_Call
(BIP_Func_Call
) then
8934 pragma Assert
(Needs_Finalization
(Etype
(BIP_Func_Call
)));
8936 -- Insert a temporary before the call initialized with function call to
8937 -- reuse the BIP machinery which takes care of adding the extra build-in
8938 -- place actuals and transforms this object declaration into an object
8939 -- renaming declaration.
8941 Tmp_Id
:= Make_Temporary
(Loc
, 'D');
8944 Make_Object_Declaration
(Loc
,
8945 Defining_Identifier
=> Tmp_Id
,
8946 Object_Definition
=>
8947 New_Occurrence_Of
(Etype
(Function_Call
), Loc
),
8948 Expression
=> Relocate_Node
(Function_Call
));
8950 Expander_Mode_Save_And_Set
(False);
8951 Insert_Action
(Function_Call
, Tmp_Decl
);
8952 Expander_Mode_Restore
;
8954 Make_Build_In_Place_Iface_Call_In_Object_Declaration
8955 (Obj_Decl
=> Tmp_Decl
,
8956 Function_Call
=> Expression
(Tmp_Decl
));
8957 end Make_Build_In_Place_Iface_Call_In_Anonymous_Context
;
8959 ----------------------------------------------------------
8960 -- Make_Build_In_Place_Iface_Call_In_Object_Declaration --
8961 ----------------------------------------------------------
8963 procedure Make_Build_In_Place_Iface_Call_In_Object_Declaration
8964 (Obj_Decl
: Node_Id
;
8965 Function_Call
: Node_Id
)
8967 BIP_Func_Call
: constant Node_Id
:=
8968 Unqual_BIP_Iface_Function_Call
(Function_Call
);
8969 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8970 Obj_Id
: constant Entity_Id
:= Defining_Entity
(Obj_Decl
);
8976 -- No action of the call has already been processed
8978 if Is_Expanded_Build_In_Place_Call
(BIP_Func_Call
) then
8982 Tmp_Id
:= Make_Temporary
(Loc
, 'D');
8984 -- Insert a temporary before N initialized with the BIP function call
8985 -- without its enclosing type conversions and analyze it without its
8986 -- expansion. This temporary facilitates us reusing the BIP machinery,
8987 -- which takes care of adding the extra build-in-place actuals and
8988 -- transforms this object declaration into an object renaming
8992 Make_Object_Declaration
(Loc
,
8993 Defining_Identifier
=> Tmp_Id
,
8994 Object_Definition
=>
8995 New_Occurrence_Of
(Etype
(BIP_Func_Call
), Loc
),
8996 Expression
=> New_Copy_Tree
(BIP_Func_Call
));
8998 Expander_Mode_Save_And_Set
(False);
8999 Insert_Action
(Obj_Decl
, Tmp_Decl
);
9000 Expander_Mode_Restore
;
9002 Make_Build_In_Place_Call_In_Object_Declaration
9003 (Obj_Decl
=> Tmp_Decl
,
9004 Function_Call
=> Expression
(Tmp_Decl
));
9006 pragma Assert
(Nkind
(Tmp_Decl
) = N_Object_Renaming_Declaration
);
9008 -- Replace the original build-in-place function call by a reference to
9009 -- the resulting temporary object renaming declaration. In this way,
9010 -- all the interface conversions performed in the original Function_Call
9011 -- on the build-in-place object are preserved.
9013 Rewrite
(BIP_Func_Call
, New_Occurrence_Of
(Tmp_Id
, Loc
));
9015 -- Replace the original object declaration by an internal object
9016 -- renaming declaration. This leaves the generated code more clean (the
9017 -- build-in-place function call in an object renaming declaration and
9018 -- displacements of the pointer to the build-in-place object in another
9019 -- renaming declaration) and allows us to invoke the routine that takes
9020 -- care of replacing the identifier of the renaming declaration (routine
9021 -- originally developed for the regular build-in-place management).
9024 Make_Object_Renaming_Declaration
(Loc
,
9025 Defining_Identifier
=> Make_Temporary
(Loc
, 'D'),
9026 Subtype_Mark
=> New_Occurrence_Of
(Etype
(Obj_Id
), Loc
),
9027 Name
=> Function_Call
));
9030 Replace_Renaming_Declaration_Id
(Obj_Decl
, Original_Node
(Obj_Decl
));
9031 end Make_Build_In_Place_Iface_Call_In_Object_Declaration
;
9033 --------------------------------------------
9034 -- Make_CPP_Constructor_Call_In_Allocator --
9035 --------------------------------------------
9037 procedure Make_CPP_Constructor_Call_In_Allocator
9038 (Allocator
: Node_Id
;
9039 Function_Call
: Node_Id
)
9041 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
9042 Acc_Type
: constant Entity_Id
:= Etype
(Allocator
);
9043 Function_Id
: constant Entity_Id
:= Entity
(Name
(Function_Call
));
9044 Result_Subt
: constant Entity_Id
:= Available_View
(Etype
(Function_Id
));
9046 New_Allocator
: Node_Id
;
9047 Return_Obj_Access
: Entity_Id
;
9051 pragma Assert
(Nkind
(Allocator
) = N_Allocator
9052 and then Nkind
(Function_Call
) = N_Function_Call
);
9053 pragma Assert
(Convention
(Function_Id
) = Convention_CPP
9054 and then Is_Constructor
(Function_Id
));
9055 pragma Assert
(Is_Constrained
(Underlying_Type
(Result_Subt
)));
9057 -- Replace the initialized allocator of form "new T'(Func (...))" with
9058 -- an uninitialized allocator of form "new T", where T is the result
9059 -- subtype of the called function. The call to the function is handled
9060 -- separately further below.
9063 Make_Allocator
(Loc
,
9064 Expression
=> New_Occurrence_Of
(Result_Subt
, Loc
));
9065 Set_No_Initialization
(New_Allocator
);
9067 -- Copy attributes to new allocator. Note that the new allocator
9068 -- logically comes from source if the original one did, so copy the
9069 -- relevant flag. This ensures proper treatment of the restriction
9070 -- No_Implicit_Heap_Allocations in this case.
9072 Set_Storage_Pool
(New_Allocator
, Storage_Pool
(Allocator
));
9073 Set_Procedure_To_Call
(New_Allocator
, Procedure_To_Call
(Allocator
));
9074 Set_Comes_From_Source
(New_Allocator
, Comes_From_Source
(Allocator
));
9076 Rewrite
(Allocator
, New_Allocator
);
9078 -- Create a new access object and initialize it to the result of the
9079 -- new uninitialized allocator. Note: we do not use Allocator as the
9080 -- Related_Node of Return_Obj_Access in call to Make_Temporary below
9081 -- as this would create a sort of infinite "recursion".
9083 Return_Obj_Access
:= Make_Temporary
(Loc
, 'R');
9084 Set_Etype
(Return_Obj_Access
, Acc_Type
);
9087 -- Rnnn : constant ptr_T := new (T);
9088 -- Init (Rnn.all,...);
9091 Make_Object_Declaration
(Loc
,
9092 Defining_Identifier
=> Return_Obj_Access
,
9093 Constant_Present
=> True,
9094 Object_Definition
=> New_Occurrence_Of
(Acc_Type
, Loc
),
9095 Expression
=> Relocate_Node
(Allocator
));
9096 Insert_Action
(Allocator
, Tmp_Obj
);
9098 Insert_List_After_And_Analyze
(Tmp_Obj
,
9099 Build_Initialization_Call
(Loc
,
9101 Make_Explicit_Dereference
(Loc
,
9102 Prefix
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
)),
9103 Typ
=> Etype
(Function_Id
),
9104 Constructor_Ref
=> Function_Call
));
9106 -- Finally, replace the allocator node with a reference to the result of
9107 -- the function call itself (which will effectively be an access to the
9108 -- object created by the allocator).
9110 Rewrite
(Allocator
, New_Occurrence_Of
(Return_Obj_Access
, Loc
));
9112 -- Ada 2005 (AI-251): If the type of the allocator is an interface then
9113 -- generate an implicit conversion to force displacement of the "this"
9116 if Is_Interface
(Designated_Type
(Acc_Type
)) then
9117 Rewrite
(Allocator
, Convert_To
(Acc_Type
, Relocate_Node
(Allocator
)));
9120 Analyze_And_Resolve
(Allocator
, Acc_Type
);
9121 end Make_CPP_Constructor_Call_In_Allocator
;
9123 -----------------------------------
9124 -- Needs_BIP_Finalization_Master --
9125 -----------------------------------
9127 function Needs_BIP_Finalization_Master
9128 (Func_Id
: Entity_Id
) return Boolean
9130 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
9131 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
9133 -- A formal giving the finalization master is needed for build-in-place
9134 -- functions whose result type needs finalization or is a tagged type.
9135 -- Tagged primitive build-in-place functions need such a formal because
9136 -- they can be called by a dispatching call, and extensions may require
9137 -- finalization even if the root type doesn't. This means they're also
9138 -- needed for tagged nonprimitive build-in-place functions with tagged
9139 -- results, since such functions can be called via access-to-function
9140 -- types, and those can be used to call primitives, so masters have to
9141 -- be passed to all such build-in-place functions, primitive or not.
9144 not Restriction_Active
(No_Finalization
)
9145 and then (Needs_Finalization
(Func_Typ
)
9146 or else Is_Tagged_Type
(Func_Typ
));
9147 end Needs_BIP_Finalization_Master
;
9149 --------------------------
9150 -- Needs_BIP_Alloc_Form --
9151 --------------------------
9153 function Needs_BIP_Alloc_Form
(Func_Id
: Entity_Id
) return Boolean is
9154 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
9155 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
9158 -- A build-in-place function needs to know which allocation form to
9161 -- 1) The result subtype is unconstrained. In this case, depending on
9162 -- the context of the call, the object may need to be created in the
9163 -- secondary stack, the heap, or a user-defined storage pool.
9165 -- 2) The result subtype is tagged. In this case the function call may
9166 -- dispatch on result and thus needs to be treated in the same way as
9167 -- calls to functions with class-wide results, because a callee that
9168 -- can be dispatched to may have any of various result subtypes, so
9169 -- if any of the possible callees would require an allocation form to
9170 -- be passed then they all do.
9172 -- 3) The result subtype needs finalization actions. In this case, based
9173 -- on the context of the call, the object may need to be created at
9174 -- the caller site, in the heap, or in a user-defined storage pool.
9177 not Is_Constrained
(Func_Typ
)
9178 or else Is_Tagged_Type
(Func_Typ
)
9179 or else Needs_Finalization
(Func_Typ
);
9180 end Needs_BIP_Alloc_Form
;
9182 --------------------------------------
9183 -- Needs_Result_Accessibility_Level --
9184 --------------------------------------
9186 function Needs_Result_Accessibility_Level
9187 (Func_Id
: Entity_Id
) return Boolean
9189 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
9191 function Has_Unconstrained_Access_Discriminant_Component
9192 (Comp_Typ
: Entity_Id
) return Boolean;
9193 -- Returns True if any component of the type has an unconstrained access
9196 -----------------------------------------------------
9197 -- Has_Unconstrained_Access_Discriminant_Component --
9198 -----------------------------------------------------
9200 function Has_Unconstrained_Access_Discriminant_Component
9201 (Comp_Typ
: Entity_Id
) return Boolean
9204 if not Is_Limited_Type
(Comp_Typ
) then
9207 -- Only limited types can have access discriminants with
9210 elsif Has_Unconstrained_Access_Discriminants
(Comp_Typ
) then
9213 elsif Is_Array_Type
(Comp_Typ
) then
9214 return Has_Unconstrained_Access_Discriminant_Component
9215 (Underlying_Type
(Component_Type
(Comp_Typ
)));
9217 elsif Is_Record_Type
(Comp_Typ
) then
9222 Comp
:= First_Component
(Comp_Typ
);
9223 while Present
(Comp
) loop
9224 if Has_Unconstrained_Access_Discriminant_Component
9225 (Underlying_Type
(Etype
(Comp
)))
9230 Next_Component
(Comp
);
9236 end Has_Unconstrained_Access_Discriminant_Component
;
9238 Feature_Disabled
: constant Boolean := True;
9241 -- Start of processing for Needs_Result_Accessibility_Level
9244 -- False if completion unavailable (how does this happen???)
9246 if not Present
(Func_Typ
) then
9249 elsif Feature_Disabled
then
9252 -- False if not a function, also handle enum-lit renames case
9254 elsif Func_Typ
= Standard_Void_Type
9255 or else Is_Scalar_Type
(Func_Typ
)
9259 -- Handle a corner case, a cross-dialect subp renaming. For example,
9260 -- an Ada 2012 renaming of an Ada 2005 subprogram. This can occur when
9261 -- an Ada 2005 (or earlier) unit references predefined run-time units.
9263 elsif Present
(Alias
(Func_Id
)) then
9265 -- Unimplemented: a cross-dialect subp renaming which does not set
9266 -- the Alias attribute (e.g., a rename of a dereference of an access
9267 -- to subprogram value). ???
9269 return Present
(Extra_Accessibility_Of_Result
(Alias
(Func_Id
)));
9271 -- Remaining cases require Ada 2012 mode
9273 elsif Ada_Version
< Ada_2012
then
9276 elsif Ekind
(Func_Typ
) = E_Anonymous_Access_Type
9277 or else Is_Tagged_Type
(Func_Typ
)
9279 -- In the case of, say, a null tagged record result type, the need
9280 -- for this extra parameter might not be obvious. This function
9281 -- returns True for all tagged types for compatibility reasons.
9282 -- A function with, say, a tagged null controlling result type might
9283 -- be overridden by a primitive of an extension having an access
9284 -- discriminant and the overrider and overridden must have compatible
9285 -- calling conventions (including implicitly declared parameters).
9286 -- Similarly, values of one access-to-subprogram type might designate
9287 -- both a primitive subprogram of a given type and a function
9288 -- which is, for example, not a primitive subprogram of any type.
9289 -- Again, this requires calling convention compatibility.
9290 -- It might be possible to solve these issues by introducing
9291 -- wrappers, but that is not the approach that was chosen.
9295 elsif Has_Unconstrained_Access_Discriminants
(Func_Typ
) then
9298 elsif Has_Unconstrained_Access_Discriminant_Component
(Func_Typ
) then
9301 -- False for all other cases
9306 end Needs_Result_Accessibility_Level
;
9308 -------------------------------------
9309 -- Replace_Renaming_Declaration_Id --
9310 -------------------------------------
9312 procedure Replace_Renaming_Declaration_Id
9313 (New_Decl
: Node_Id
;
9314 Orig_Decl
: Node_Id
)
9316 New_Id
: constant Entity_Id
:= Defining_Entity
(New_Decl
);
9317 Orig_Id
: constant Entity_Id
:= Defining_Entity
(Orig_Decl
);
9320 Set_Chars
(New_Id
, Chars
(Orig_Id
));
9322 -- Swap next entity links in preparation for exchanging entities
9325 Next_Id
: constant Entity_Id
:= Next_Entity
(New_Id
);
9327 Link_Entities
(New_Id
, Next_Entity
(Orig_Id
));
9328 Link_Entities
(Orig_Id
, Next_Id
);
9331 Set_Homonym
(New_Id
, Homonym
(Orig_Id
));
9332 Exchange_Entities
(New_Id
, Orig_Id
);
9334 -- Preserve source indication of original declaration, so that xref
9335 -- information is properly generated for the right entity.
9337 Preserve_Comes_From_Source
(New_Decl
, Orig_Decl
);
9338 Preserve_Comes_From_Source
(Orig_Id
, Orig_Decl
);
9340 Set_Comes_From_Source
(New_Id
, False);
9341 end Replace_Renaming_Declaration_Id
;
9343 ---------------------------------
9344 -- Rewrite_Function_Call_For_C --
9345 ---------------------------------
9347 procedure Rewrite_Function_Call_For_C
(N
: Node_Id
) is
9348 Orig_Func
: constant Entity_Id
:= Entity
(Name
(N
));
9349 Func_Id
: constant Entity_Id
:= Ultimate_Alias
(Orig_Func
);
9350 Par
: constant Node_Id
:= Parent
(N
);
9351 Proc_Id
: constant Entity_Id
:= Corresponding_Procedure
(Func_Id
);
9352 Loc
: constant Source_Ptr
:= Sloc
(Par
);
9354 Last_Actual
: Node_Id
;
9355 Last_Formal
: Entity_Id
;
9357 -- Start of processing for Rewrite_Function_Call_For_C
9360 -- The actuals may be given by named associations, so the added actual
9361 -- that is the target of the return value of the call must be a named
9362 -- association as well, so we retrieve the name of the generated
9365 Last_Formal
:= First_Formal
(Proc_Id
);
9366 while Present
(Next_Formal
(Last_Formal
)) loop
9367 Last_Formal
:= Next_Formal
(Last_Formal
);
9370 Actuals
:= Parameter_Associations
(N
);
9372 -- The original function may lack parameters
9374 if No
(Actuals
) then
9375 Actuals
:= New_List
;
9378 -- If the function call is the expression of an assignment statement,
9379 -- transform the assignment into a procedure call. Generate:
9381 -- LHS := Func_Call (...);
9383 -- Proc_Call (..., LHS);
9385 -- If function is inherited, a conversion may be necessary.
9387 if Nkind
(Par
) = N_Assignment_Statement
then
9388 Last_Actual
:= Name
(Par
);
9390 if not Comes_From_Source
(Orig_Func
)
9391 and then Etype
(Orig_Func
) /= Etype
(Func_Id
)
9394 Make_Type_Conversion
(Loc
,
9395 New_Occurrence_Of
(Etype
(Func_Id
), Loc
),
9400 Make_Parameter_Association
(Loc
,
9402 Make_Identifier
(Loc
, Chars
(Last_Formal
)),
9403 Explicit_Actual_Parameter
=> Last_Actual
));
9406 Make_Procedure_Call_Statement
(Loc
,
9407 Name
=> New_Occurrence_Of
(Proc_Id
, Loc
),
9408 Parameter_Associations
=> Actuals
));
9411 -- Otherwise the context is an expression. Generate a temporary and a
9412 -- procedure call to obtain the function result. Generate:
9414 -- ... Func_Call (...) ...
9417 -- Proc_Call (..., Temp);
9422 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
9431 Make_Object_Declaration
(Loc
,
9432 Defining_Identifier
=> Temp_Id
,
9433 Object_Definition
=>
9434 New_Occurrence_Of
(Etype
(Func_Id
), Loc
));
9437 -- Proc_Call (..., Temp);
9440 Make_Parameter_Association
(Loc
,
9442 Make_Identifier
(Loc
, Chars
(Last_Formal
)),
9443 Explicit_Actual_Parameter
=>
9444 New_Occurrence_Of
(Temp_Id
, Loc
)));
9447 Make_Procedure_Call_Statement
(Loc
,
9448 Name
=> New_Occurrence_Of
(Proc_Id
, Loc
),
9449 Parameter_Associations
=> Actuals
);
9451 Insert_Actions
(Par
, New_List
(Decl
, Call
));
9452 Rewrite
(N
, New_Occurrence_Of
(Temp_Id
, Loc
));
9455 end Rewrite_Function_Call_For_C
;
9457 ------------------------------------
9458 -- Set_Enclosing_Sec_Stack_Return --
9459 ------------------------------------
9461 procedure Set_Enclosing_Sec_Stack_Return
(N
: Node_Id
) is
9465 -- Due to a possible mix of internally generated blocks, source blocks
9466 -- and loops, the scope stack may not be contiguous as all labels are
9467 -- inserted at the top level within the related function. Instead,
9468 -- perform a parent-based traversal and mark all appropriate constructs.
9470 while Present
(P
) loop
9472 -- Mark the label of a source or internally generated block or
9475 if Nkind_In
(P
, N_Block_Statement
, N_Loop_Statement
) then
9476 Set_Sec_Stack_Needed_For_Return
(Entity
(Identifier
(P
)));
9478 -- Mark the enclosing function
9480 elsif Nkind
(P
) = N_Subprogram_Body
then
9481 if Present
(Corresponding_Spec
(P
)) then
9482 Set_Sec_Stack_Needed_For_Return
(Corresponding_Spec
(P
));
9484 Set_Sec_Stack_Needed_For_Return
(Defining_Entity
(P
));
9487 -- Do not go beyond the enclosing function
9494 end Set_Enclosing_Sec_Stack_Return
;
9496 ------------------------------------
9497 -- Unqual_BIP_Iface_Function_Call --
9498 ------------------------------------
9500 function Unqual_BIP_Iface_Function_Call
(Expr
: Node_Id
) return Node_Id
is
9501 Has_Pointer_Displacement
: Boolean := False;
9502 On_Object_Declaration
: Boolean := False;
9503 -- Remember if processing the renaming expressions on recursion we have
9504 -- traversed an object declaration, since we can traverse many object
9505 -- declaration renamings but just one regular object declaration.
9507 function Unqual_BIP_Function_Call
(Expr
: Node_Id
) return Node_Id
;
9508 -- Search for a build-in-place function call skipping any qualification
9509 -- including qualified expressions, type conversions, references, calls
9510 -- to displace the pointer to the object, and renamings. Return Empty if
9511 -- no build-in-place function call is found.
9513 ------------------------------
9514 -- Unqual_BIP_Function_Call --
9515 ------------------------------
9517 function Unqual_BIP_Function_Call
(Expr
: Node_Id
) return Node_Id
is
9519 -- Recurse to handle case of multiple levels of qualification and/or
9522 if Nkind_In
(Expr
, N_Qualified_Expression
,
9524 N_Unchecked_Type_Conversion
)
9526 return Unqual_BIP_Function_Call
(Expression
(Expr
));
9528 -- Recurse to handle case of multiple levels of references and
9529 -- explicit dereferences.
9531 elsif Nkind_In
(Expr
, N_Attribute_Reference
,
9532 N_Explicit_Dereference
,
9535 return Unqual_BIP_Function_Call
(Prefix
(Expr
));
9537 -- Recurse on object renamings
9539 elsif Nkind
(Expr
) = N_Identifier
9540 and then Present
(Entity
(Expr
))
9541 and then Ekind_In
(Entity
(Expr
), E_Constant
, E_Variable
)
9542 and then Nkind
(Parent
(Entity
(Expr
))) =
9543 N_Object_Renaming_Declaration
9544 and then Present
(Renamed_Object
(Entity
(Expr
)))
9546 return Unqual_BIP_Function_Call
(Renamed_Object
(Entity
(Expr
)));
9548 -- Recurse on the initializing expression of the first reference of
9549 -- an object declaration.
9551 elsif not On_Object_Declaration
9552 and then Nkind
(Expr
) = N_Identifier
9553 and then Present
(Entity
(Expr
))
9554 and then Ekind_In
(Entity
(Expr
), E_Constant
, E_Variable
)
9555 and then Nkind
(Parent
(Entity
(Expr
))) = N_Object_Declaration
9556 and then Present
(Expression
(Parent
(Entity
(Expr
))))
9558 On_Object_Declaration
:= True;
9560 Unqual_BIP_Function_Call
(Expression
(Parent
(Entity
(Expr
))));
9562 -- Recurse to handle calls to displace the pointer to the object to
9563 -- reference a secondary dispatch table.
9565 elsif Nkind
(Expr
) = N_Function_Call
9566 and then Nkind
(Name
(Expr
)) in N_Has_Entity
9567 and then Present
(Entity
(Name
(Expr
)))
9568 and then RTU_Loaded
(Ada_Tags
)
9569 and then RTE_Available
(RE_Displace
)
9570 and then Is_RTE
(Entity
(Name
(Expr
)), RE_Displace
)
9572 Has_Pointer_Displacement
:= True;
9574 Unqual_BIP_Function_Call
(First
(Parameter_Associations
(Expr
)));
9576 -- Normal case: check if the inner expression is a BIP function call
9577 -- and the pointer to the object is displaced.
9579 elsif Has_Pointer_Displacement
9580 and then Is_Build_In_Place_Function_Call
(Expr
)
9587 end Unqual_BIP_Function_Call
;
9589 -- Start of processing for Unqual_BIP_Iface_Function_Call
9592 if Nkind
(Expr
) = N_Identifier
and then No
(Entity
(Expr
)) then
9594 -- Can happen for X'Elab_Spec in the binder-generated file
9599 return Unqual_BIP_Function_Call
(Expr
);
9600 end Unqual_BIP_Iface_Function_Call
;