1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2017, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree
; use Atree
;
27 with Checks
; use Checks
;
28 with Contracts
; use Contracts
;
29 with Debug
; use Debug
;
30 with Einfo
; use Einfo
;
31 with Errout
; use Errout
;
32 with Elists
; use Elists
;
33 with Expander
; use Expander
;
34 with Exp_Aggr
; use Exp_Aggr
;
35 with Exp_Atag
; use Exp_Atag
;
36 with Exp_Ch2
; use Exp_Ch2
;
37 with Exp_Ch3
; use Exp_Ch3
;
38 with Exp_Ch7
; use Exp_Ch7
;
39 with Exp_Ch9
; use Exp_Ch9
;
40 with Exp_Dbug
; use Exp_Dbug
;
41 with Exp_Disp
; use Exp_Disp
;
42 with Exp_Dist
; use Exp_Dist
;
43 with Exp_Intr
; use Exp_Intr
;
44 with Exp_Pakd
; use Exp_Pakd
;
45 with Exp_Tss
; use Exp_Tss
;
46 with Exp_Util
; use Exp_Util
;
47 with Freeze
; use Freeze
;
48 with Inline
; use Inline
;
49 with Itypes
; use Itypes
;
51 with Namet
; use Namet
;
52 with Nlists
; use Nlists
;
53 with Nmake
; use Nmake
;
55 with Restrict
; use Restrict
;
56 with Rident
; use Rident
;
57 with Rtsfind
; use Rtsfind
;
59 with Sem_Aux
; use Sem_Aux
;
60 with Sem_Ch6
; use Sem_Ch6
;
61 with Sem_Ch8
; use Sem_Ch8
;
62 with Sem_Ch12
; use Sem_Ch12
;
63 with Sem_Ch13
; use Sem_Ch13
;
64 with Sem_Dim
; use Sem_Dim
;
65 with Sem_Disp
; use Sem_Disp
;
66 with Sem_Dist
; use Sem_Dist
;
67 with Sem_Eval
; use Sem_Eval
;
68 with Sem_Mech
; use Sem_Mech
;
69 with Sem_Res
; use Sem_Res
;
70 with Sem_SCIL
; use Sem_SCIL
;
71 with Sem_Util
; use Sem_Util
;
72 with Sinfo
; use Sinfo
;
73 with Snames
; use Snames
;
74 with Stand
; use Stand
;
75 with Tbuild
; use Tbuild
;
76 with Uintp
; use Uintp
;
77 with Validsw
; use Validsw
;
79 package body Exp_Ch6
is
81 -----------------------
82 -- Local Subprograms --
83 -----------------------
85 procedure Add_Access_Actual_To_Build_In_Place_Call
86 (Function_Call
: Node_Id
;
87 Function_Id
: Entity_Id
;
88 Return_Object
: Node_Id
;
89 Is_Access
: Boolean := False);
90 -- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
91 -- object name given by Return_Object and add the attribute to the end of
92 -- the actual parameter list associated with the build-in-place function
93 -- call denoted by Function_Call. However, if Is_Access is True, then
94 -- Return_Object is already an access expression, in which case it's passed
95 -- along directly to the build-in-place function. Finally, if Return_Object
96 -- is empty, then pass a null literal as the actual.
98 procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
99 (Function_Call
: Node_Id
;
100 Function_Id
: Entity_Id
;
101 Alloc_Form
: BIP_Allocation_Form
:= Unspecified
;
102 Alloc_Form_Exp
: Node_Id
:= Empty
;
103 Pool_Actual
: Node_Id
:= Make_Null
(No_Location
));
104 -- Ada 2005 (AI-318-02): Add the actuals needed for a build-in-place
105 -- function call that returns a caller-unknown-size result (BIP_Alloc_Form
106 -- and BIP_Storage_Pool). If Alloc_Form_Exp is present, then use it,
107 -- otherwise pass a literal corresponding to the Alloc_Form parameter
108 -- (which must not be Unspecified in that case). Pool_Actual is the
109 -- parameter to pass to BIP_Storage_Pool.
111 procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
112 (Func_Call
: Node_Id
;
114 Ptr_Typ
: Entity_Id
:= Empty
;
115 Master_Exp
: Node_Id
:= Empty
);
116 -- Ada 2005 (AI-318-02): If the result type of a build-in-place call needs
117 -- finalization actions, add an actual parameter which is a pointer to the
118 -- finalization master of the caller. If Master_Exp is not Empty, then that
119 -- will be passed as the actual. Otherwise, if Ptr_Typ is left Empty, this
120 -- will result in an automatic "null" value for the actual.
122 procedure Add_Task_Actuals_To_Build_In_Place_Call
123 (Function_Call
: Node_Id
;
124 Function_Id
: Entity_Id
;
125 Master_Actual
: Node_Id
;
126 Chain
: Node_Id
:= Empty
);
127 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
128 -- contains tasks, add two actual parameters: the master, and a pointer to
129 -- the caller's activation chain. Master_Actual is the actual parameter
130 -- expression to pass for the master. In most cases, this is the current
131 -- master (_master). The two exceptions are: If the function call is the
132 -- initialization expression for an allocator, we pass the master of the
133 -- access type. If the function call is the initialization expression for a
134 -- return object, we pass along the master passed in by the caller. In most
135 -- contexts, the activation chain to pass is the local one, which is
136 -- indicated by No (Chain). However, in an allocator, the caller passes in
137 -- the activation Chain. Note: Master_Actual can be Empty, but only if
138 -- there are no tasks.
140 function Caller_Known_Size
141 (Func_Call
: Node_Id
;
142 Result_Subt
: Entity_Id
) return Boolean;
143 -- True if result subtype is definite, or has a size that does not require
144 -- secondary stack usage (i.e. no variant part or components whose type
145 -- depends on discriminants). In particular, untagged types with only
146 -- access discriminants do not require secondary stack use. Note we must
147 -- always use the secondary stack for dispatching-on-result calls.
149 procedure Check_Overriding_Operation
(Subp
: Entity_Id
);
150 -- Subp is a dispatching operation. Check whether it may override an
151 -- inherited private operation, in which case its DT entry is that of
152 -- the hidden operation, not the one it may have received earlier.
153 -- This must be done before emitting the code to set the corresponding
154 -- DT to the address of the subprogram. The actual placement of Subp in
155 -- the proper place in the list of primitive operations is done in
156 -- Declare_Inherited_Private_Subprograms, which also has to deal with
157 -- implicit operations. This duplication is unavoidable for now???
159 procedure Detect_Infinite_Recursion
(N
: Node_Id
; Spec
: Entity_Id
);
160 -- This procedure is called only if the subprogram body N, whose spec
161 -- has the given entity Spec, contains a parameterless recursive call.
162 -- It attempts to generate runtime code to detect if this a case of
163 -- infinite recursion.
165 -- The body is scanned to determine dependencies. If the only external
166 -- dependencies are on a small set of scalar variables, then the values
167 -- of these variables are captured on entry to the subprogram, and if
168 -- the values are not changed for the call, we know immediately that
169 -- we have an infinite recursion.
171 procedure Expand_Actuals
174 Post_Call
: out List_Id
);
175 -- Return a list of actions to take place after the call in Post_Call. The
176 -- call will later be rewritten as an Expression_With_Actions, with the
177 -- Post_Call actions inserted, and the call inside.
179 -- For each actual of an in-out or out parameter which is a numeric (view)
180 -- conversion of the form T (A), where A denotes a variable, we insert the
183 -- Temp : T[ := T (A)];
185 -- prior to the call. Then we replace the actual with a reference to Temp,
186 -- and append the assignment:
188 -- A := TypeA (Temp);
190 -- after the call. Here TypeA is the actual type of variable A. For out
191 -- parameters, the initial declaration has no expression. If A is not an
192 -- entity name, we generate instead:
194 -- Var : TypeA renames A;
195 -- Temp : T := Var; -- omitting expression for out parameter.
197 -- Var := TypeA (Temp);
199 -- For other in-out parameters, we emit the required constraint checks
200 -- before and/or after the call.
202 -- For all parameter modes, actuals that denote components and slices of
203 -- packed arrays are expanded into suitable temporaries.
205 -- For non-scalar objects that are possibly unaligned, add call by copy
206 -- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
208 -- For OUT and IN OUT parameters, add predicate checks after the call
209 -- based on the predicates of the actual type.
211 procedure Expand_Call_Helper
(N
: Node_Id
; Post_Call
: out List_Id
);
212 -- Does the main work of Expand_Call. Post_Call is as for Expand_Actuals.
214 procedure Expand_Ctrl_Function_Call
(N
: Node_Id
);
215 -- N is a function call which returns a controlled object. Transform the
216 -- call into a temporary which retrieves the returned object from the
217 -- secondary stack using 'reference.
219 procedure Expand_Non_Function_Return
(N
: Node_Id
);
220 -- Expand a simple return statement found in a procedure body, entry body,
221 -- accept statement, or an extended return statement. Note that all non-
222 -- function returns are simple return statements.
224 function Expand_Protected_Object_Reference
226 Scop
: Entity_Id
) return Node_Id
;
228 procedure Expand_Protected_Subprogram_Call
232 -- A call to a protected subprogram within the protected object may appear
233 -- as a regular call. The list of actuals must be expanded to contain a
234 -- reference to the object itself, and the call becomes a call to the
235 -- corresponding protected subprogram.
237 procedure Expand_Simple_Function_Return
(N
: Node_Id
);
238 -- Expand simple return from function. In the case where we are returning
239 -- from a function body this is called by Expand_N_Simple_Return_Statement.
241 function Has_Unconstrained_Access_Discriminants
242 (Subtyp
: Entity_Id
) return Boolean;
243 -- Returns True if the given subtype is unconstrained and has one or more
244 -- access discriminants.
246 procedure Insert_Post_Call_Actions
(N
: Node_Id
; Post_Call
: List_Id
);
247 -- Insert the Post_Call list previously produced by routine Expand_Actuals
248 -- or Expand_Call_Helper into the tree.
250 procedure Replace_Renaming_Declaration_Id
252 Orig_Decl
: Node_Id
);
253 -- Replace the internal identifier of the new renaming declaration New_Decl
254 -- with the identifier of its original declaration Orig_Decl exchanging the
255 -- entities containing their defining identifiers to ensure the correct
256 -- replacement of the object declaration by the object renaming declaration
257 -- to avoid homograph conflicts (since the object declaration's defining
258 -- identifier was already entered in the current scope). The Next_Entity
259 -- links of the two entities are also swapped since the entities are part
260 -- of the return scope's entity list and the list structure would otherwise
261 -- be corrupted. The homonym chain is preserved as well.
263 procedure Rewrite_Function_Call_For_C
(N
: Node_Id
);
264 -- When generating C code, replace a call to a function that returns an
265 -- array into the generated procedure with an additional out parameter.
267 procedure Set_Enclosing_Sec_Stack_Return
(N
: Node_Id
);
268 -- N is a return statement for a function that returns its result on the
269 -- secondary stack. This sets the Sec_Stack_Needed_For_Return flag on the
270 -- function and all blocks and loops that the return statement is jumping
271 -- out of. This ensures that the secondary stack is not released; otherwise
272 -- the function result would be reclaimed before returning to the caller.
274 ----------------------------------------------
275 -- Add_Access_Actual_To_Build_In_Place_Call --
276 ----------------------------------------------
278 procedure Add_Access_Actual_To_Build_In_Place_Call
279 (Function_Call
: Node_Id
;
280 Function_Id
: Entity_Id
;
281 Return_Object
: Node_Id
;
282 Is_Access
: Boolean := False)
284 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
285 Obj_Address
: Node_Id
;
286 Obj_Acc_Formal
: Entity_Id
;
289 -- Locate the implicit access parameter in the called function
291 Obj_Acc_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Object_Access
);
293 -- If no return object is provided, then pass null
295 if not Present
(Return_Object
) then
296 Obj_Address
:= Make_Null
(Loc
);
297 Set_Parent
(Obj_Address
, Function_Call
);
299 -- If Return_Object is already an expression of an access type, then use
300 -- it directly, since it must be an access value denoting the return
301 -- object, and couldn't possibly be the return object itself.
304 Obj_Address
:= Return_Object
;
305 Set_Parent
(Obj_Address
, Function_Call
);
307 -- Apply Unrestricted_Access to caller's return object
311 Make_Attribute_Reference
(Loc
,
312 Prefix
=> Return_Object
,
313 Attribute_Name
=> Name_Unrestricted_Access
);
315 Set_Parent
(Return_Object
, Obj_Address
);
316 Set_Parent
(Obj_Address
, Function_Call
);
319 Analyze_And_Resolve
(Obj_Address
, Etype
(Obj_Acc_Formal
));
321 -- Build the parameter association for the new actual and add it to the
322 -- end of the function's actuals.
324 Add_Extra_Actual_To_Call
(Function_Call
, Obj_Acc_Formal
, Obj_Address
);
325 end Add_Access_Actual_To_Build_In_Place_Call
;
327 ------------------------------------------------------
328 -- Add_Unconstrained_Actuals_To_Build_In_Place_Call --
329 ------------------------------------------------------
331 procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
332 (Function_Call
: Node_Id
;
333 Function_Id
: Entity_Id
;
334 Alloc_Form
: BIP_Allocation_Form
:= Unspecified
;
335 Alloc_Form_Exp
: Node_Id
:= Empty
;
336 Pool_Actual
: Node_Id
:= Make_Null
(No_Location
))
338 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
339 Alloc_Form_Actual
: Node_Id
;
340 Alloc_Form_Formal
: Node_Id
;
341 Pool_Formal
: Node_Id
;
344 -- The allocation form generally doesn't need to be passed in the case
345 -- of a constrained result subtype, since normally the caller performs
346 -- the allocation in that case. However this formal is still needed in
347 -- the case where the function has a tagged result, because generally
348 -- such functions can be called in a dispatching context and such calls
349 -- must be handled like calls to class-wide functions.
351 if Is_Constrained
(Underlying_Type
(Etype
(Function_Id
)))
352 and then not Is_Tagged_Type
(Underlying_Type
(Etype
(Function_Id
)))
357 -- Locate the implicit allocation form parameter in the called function.
358 -- Maybe it would be better for each implicit formal of a build-in-place
359 -- function to have a flag or a Uint attribute to identify it. ???
361 Alloc_Form_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Alloc_Form
);
363 if Present
(Alloc_Form_Exp
) then
364 pragma Assert
(Alloc_Form
= Unspecified
);
366 Alloc_Form_Actual
:= Alloc_Form_Exp
;
369 pragma Assert
(Alloc_Form
/= Unspecified
);
372 Make_Integer_Literal
(Loc
,
373 Intval
=> UI_From_Int
(BIP_Allocation_Form
'Pos (Alloc_Form
)));
376 Analyze_And_Resolve
(Alloc_Form_Actual
, Etype
(Alloc_Form_Formal
));
378 -- Build the parameter association for the new actual and add it to the
379 -- end of the function's actuals.
381 Add_Extra_Actual_To_Call
382 (Function_Call
, Alloc_Form_Formal
, Alloc_Form_Actual
);
384 -- Pass the Storage_Pool parameter. This parameter is omitted on
385 -- ZFP as those targets do not support pools.
387 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
388 Pool_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Storage_Pool
);
389 Analyze_And_Resolve
(Pool_Actual
, Etype
(Pool_Formal
));
390 Add_Extra_Actual_To_Call
391 (Function_Call
, Pool_Formal
, Pool_Actual
);
393 end Add_Unconstrained_Actuals_To_Build_In_Place_Call
;
395 -----------------------------------------------------------
396 -- Add_Finalization_Master_Actual_To_Build_In_Place_Call --
397 -----------------------------------------------------------
399 procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
400 (Func_Call
: Node_Id
;
402 Ptr_Typ
: Entity_Id
:= Empty
;
403 Master_Exp
: Node_Id
:= Empty
)
406 if not Needs_BIP_Finalization_Master
(Func_Id
) then
411 Formal
: constant Entity_Id
:=
412 Build_In_Place_Formal
(Func_Id
, BIP_Finalization_Master
);
413 Loc
: constant Source_Ptr
:= Sloc
(Func_Call
);
416 Desig_Typ
: Entity_Id
;
419 -- If there is a finalization master actual, such as the implicit
420 -- finalization master of an enclosing build-in-place function,
421 -- then this must be added as an extra actual of the call.
423 if Present
(Master_Exp
) then
424 Actual
:= Master_Exp
;
426 -- Case where the context does not require an actual master
428 elsif No
(Ptr_Typ
) then
429 Actual
:= Make_Null
(Loc
);
432 Desig_Typ
:= Directly_Designated_Type
(Ptr_Typ
);
434 -- Check for a library-level access type whose designated type has
435 -- suppressed finalization or the access type is subject to pragma
436 -- No_Heap_Finalization. Such an access type lacks a master. Pass
437 -- a null actual to callee in order to signal a missing master.
439 if Is_Library_Level_Entity
(Ptr_Typ
)
440 and then (Finalize_Storage_Only
(Desig_Typ
)
441 or else No_Heap_Finalization
(Ptr_Typ
))
443 Actual
:= Make_Null
(Loc
);
445 -- Types in need of finalization actions
447 elsif Needs_Finalization
(Desig_Typ
) then
449 -- The general mechanism of creating finalization masters for
450 -- anonymous access types is disabled by default, otherwise
451 -- finalization masters will pop all over the place. Such types
452 -- use context-specific masters.
454 if Ekind
(Ptr_Typ
) = E_Anonymous_Access_Type
455 and then No
(Finalization_Master
(Ptr_Typ
))
457 Build_Anonymous_Master
(Ptr_Typ
);
460 -- Access-to-controlled types should always have a master
462 pragma Assert
(Present
(Finalization_Master
(Ptr_Typ
)));
465 Make_Attribute_Reference
(Loc
,
467 New_Occurrence_Of
(Finalization_Master
(Ptr_Typ
), Loc
),
468 Attribute_Name
=> Name_Unrestricted_Access
);
473 Actual
:= Make_Null
(Loc
);
477 Analyze_And_Resolve
(Actual
, Etype
(Formal
));
479 -- Build the parameter association for the new actual and add it to
480 -- the end of the function's actuals.
482 Add_Extra_Actual_To_Call
(Func_Call
, Formal
, Actual
);
484 end Add_Finalization_Master_Actual_To_Build_In_Place_Call
;
486 ------------------------------
487 -- Add_Extra_Actual_To_Call --
488 ------------------------------
490 procedure Add_Extra_Actual_To_Call
491 (Subprogram_Call
: Node_Id
;
492 Extra_Formal
: Entity_Id
;
493 Extra_Actual
: Node_Id
)
495 Loc
: constant Source_Ptr
:= Sloc
(Subprogram_Call
);
496 Param_Assoc
: Node_Id
;
500 Make_Parameter_Association
(Loc
,
501 Selector_Name
=> New_Occurrence_Of
(Extra_Formal
, Loc
),
502 Explicit_Actual_Parameter
=> Extra_Actual
);
504 Set_Parent
(Param_Assoc
, Subprogram_Call
);
505 Set_Parent
(Extra_Actual
, Param_Assoc
);
507 if Present
(Parameter_Associations
(Subprogram_Call
)) then
508 if Nkind
(Last
(Parameter_Associations
(Subprogram_Call
))) =
509 N_Parameter_Association
512 -- Find last named actual, and append
517 L
:= First_Actual
(Subprogram_Call
);
518 while Present
(L
) loop
519 if No
(Next_Actual
(L
)) then
520 Set_Next_Named_Actual
(Parent
(L
), Extra_Actual
);
528 Set_First_Named_Actual
(Subprogram_Call
, Extra_Actual
);
531 Append
(Param_Assoc
, To
=> Parameter_Associations
(Subprogram_Call
));
534 Set_Parameter_Associations
(Subprogram_Call
, New_List
(Param_Assoc
));
535 Set_First_Named_Actual
(Subprogram_Call
, Extra_Actual
);
537 end Add_Extra_Actual_To_Call
;
539 ---------------------------------------------
540 -- Add_Task_Actuals_To_Build_In_Place_Call --
541 ---------------------------------------------
543 procedure Add_Task_Actuals_To_Build_In_Place_Call
544 (Function_Call
: Node_Id
;
545 Function_Id
: Entity_Id
;
546 Master_Actual
: Node_Id
;
547 Chain
: Node_Id
:= Empty
)
549 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
550 Result_Subt
: constant Entity_Id
:=
551 Available_View
(Etype
(Function_Id
));
553 Chain_Actual
: Node_Id
;
554 Chain_Formal
: Node_Id
;
555 Master_Formal
: Node_Id
;
558 -- No such extra parameters are needed if there are no tasks
560 if not Has_Task
(Result_Subt
) then
564 Actual
:= Master_Actual
;
566 -- Use a dummy _master actual in case of No_Task_Hierarchy
568 if Restriction_Active
(No_Task_Hierarchy
) then
569 Actual
:= New_Occurrence_Of
(RTE
(RE_Library_Task_Level
), Loc
);
571 -- In the case where we use the master associated with an access type,
572 -- the actual is an entity and requires an explicit reference.
574 elsif Nkind
(Actual
) = N_Defining_Identifier
then
575 Actual
:= New_Occurrence_Of
(Actual
, Loc
);
578 -- Locate the implicit master parameter in the called function
580 Master_Formal
:= Build_In_Place_Formal
(Function_Id
, BIP_Task_Master
);
581 Analyze_And_Resolve
(Actual
, Etype
(Master_Formal
));
583 -- Build the parameter association for the new actual and add it to the
584 -- end of the function's actuals.
586 Add_Extra_Actual_To_Call
(Function_Call
, Master_Formal
, Actual
);
588 -- Locate the implicit activation chain parameter in the called function
591 Build_In_Place_Formal
(Function_Id
, BIP_Activation_Chain
);
593 -- Create the actual which is a pointer to the current activation chain
597 Make_Attribute_Reference
(Loc
,
598 Prefix
=> Make_Identifier
(Loc
, Name_uChain
),
599 Attribute_Name
=> Name_Unrestricted_Access
);
601 -- Allocator case; make a reference to the Chain passed in by the caller
605 Make_Attribute_Reference
(Loc
,
606 Prefix
=> New_Occurrence_Of
(Chain
, Loc
),
607 Attribute_Name
=> Name_Unrestricted_Access
);
610 Analyze_And_Resolve
(Chain_Actual
, Etype
(Chain_Formal
));
612 -- Build the parameter association for the new actual and add it to the
613 -- end of the function's actuals.
615 Add_Extra_Actual_To_Call
(Function_Call
, Chain_Formal
, Chain_Actual
);
616 end Add_Task_Actuals_To_Build_In_Place_Call
;
618 -----------------------
619 -- BIP_Formal_Suffix --
620 -----------------------
622 function BIP_Formal_Suffix
(Kind
: BIP_Formal_Kind
) return String is
625 when BIP_Alloc_Form
=>
628 when BIP_Storage_Pool
=>
629 return "BIPstoragepool";
631 when BIP_Finalization_Master
=>
632 return "BIPfinalizationmaster";
634 when BIP_Task_Master
=>
635 return "BIPtaskmaster";
637 when BIP_Activation_Chain
=>
638 return "BIPactivationchain";
640 when BIP_Object_Access
=>
643 end BIP_Formal_Suffix
;
645 ---------------------------
646 -- Build_In_Place_Formal --
647 ---------------------------
649 function Build_In_Place_Formal
651 Kind
: BIP_Formal_Kind
) return Entity_Id
653 Formal_Name
: constant Name_Id
:=
655 (Chars
(Func
), BIP_Formal_Suffix
(Kind
));
656 Extra_Formal
: Entity_Id
:= Extra_Formals
(Func
);
659 -- Maybe it would be better for each implicit formal of a build-in-place
660 -- function to have a flag or a Uint attribute to identify it. ???
662 -- The return type in the function declaration may have been a limited
663 -- view, and the extra formals for the function were not generated at
664 -- that point. At the point of call the full view must be available and
665 -- the extra formals can be created.
667 if No
(Extra_Formal
) then
668 Create_Extra_Formals
(Func
);
669 Extra_Formal
:= Extra_Formals
(Func
);
673 pragma Assert
(Present
(Extra_Formal
));
674 exit when Chars
(Extra_Formal
) = Formal_Name
;
676 Next_Formal_With_Extras
(Extra_Formal
);
680 end Build_In_Place_Formal
;
682 -------------------------------
683 -- Build_Procedure_Body_Form --
684 -------------------------------
686 function Build_Procedure_Body_Form
687 (Func_Id
: Entity_Id
;
688 Func_Body
: Node_Id
) return Node_Id
690 Loc
: constant Source_Ptr
:= Sloc
(Func_Body
);
692 Proc_Decl
: constant Node_Id
:=
693 Next
(Unit_Declaration_Node
(Func_Id
));
694 -- It is assumed that the next node following the declaration of the
695 -- corresponding subprogram spec is the declaration of the procedure
698 Proc_Id
: constant Entity_Id
:= Defining_Entity
(Proc_Decl
);
700 procedure Replace_Returns
(Param_Id
: Entity_Id
; Stmts
: List_Id
);
701 -- Replace each return statement found in the list Stmts with an
702 -- assignment of the return expression to parameter Param_Id.
704 ---------------------
705 -- Replace_Returns --
706 ---------------------
708 procedure Replace_Returns
(Param_Id
: Entity_Id
; Stmts
: List_Id
) is
712 Stmt
:= First
(Stmts
);
713 while Present
(Stmt
) loop
714 if Nkind
(Stmt
) = N_Block_Statement
then
715 Replace_Returns
(Param_Id
, Statements
(Stmt
));
717 elsif Nkind
(Stmt
) = N_Case_Statement
then
721 Alt
:= First
(Alternatives
(Stmt
));
722 while Present
(Alt
) loop
723 Replace_Returns
(Param_Id
, Statements
(Alt
));
728 elsif Nkind
(Stmt
) = N_Extended_Return_Statement
then
730 Ret_Obj
: constant Entity_Id
:=
732 (First
(Return_Object_Declarations
(Stmt
)));
733 Assign
: constant Node_Id
:=
734 Make_Assignment_Statement
(Sloc
(Stmt
),
736 New_Occurrence_Of
(Param_Id
, Loc
),
738 New_Occurrence_Of
(Ret_Obj
, Sloc
(Stmt
)));
742 -- The extended return may just contain the declaration
744 if Present
(Handled_Statement_Sequence
(Stmt
)) then
745 Stmts
:= Statements
(Handled_Statement_Sequence
(Stmt
));
750 Set_Assignment_OK
(Name
(Assign
));
753 Make_Block_Statement
(Sloc
(Stmt
),
755 Return_Object_Declarations
(Stmt
),
756 Handled_Statement_Sequence
=>
757 Make_Handled_Sequence_Of_Statements
(Loc
,
758 Statements
=> Stmts
)));
760 Replace_Returns
(Param_Id
, Stmts
);
762 Append_To
(Stmts
, Assign
);
763 Append_To
(Stmts
, Make_Simple_Return_Statement
(Loc
));
766 elsif Nkind
(Stmt
) = N_If_Statement
then
767 Replace_Returns
(Param_Id
, Then_Statements
(Stmt
));
768 Replace_Returns
(Param_Id
, Else_Statements
(Stmt
));
773 Part
:= First
(Elsif_Parts
(Stmt
));
774 while Present
(Part
) loop
775 Replace_Returns
(Param_Id
, Then_Statements
(Part
));
780 elsif Nkind
(Stmt
) = N_Loop_Statement
then
781 Replace_Returns
(Param_Id
, Statements
(Stmt
));
783 elsif Nkind
(Stmt
) = N_Simple_Return_Statement
then
790 Make_Assignment_Statement
(Sloc
(Stmt
),
791 Name
=> New_Occurrence_Of
(Param_Id
, Loc
),
792 Expression
=> Relocate_Node
(Expression
(Stmt
))));
794 Insert_After
(Stmt
, Make_Simple_Return_Statement
(Loc
));
796 -- Skip the added return
810 -- Start of processing for Build_Procedure_Body_Form
813 -- This routine replaces the original function body:
815 -- function F (...) return Array_Typ is
821 -- with the following:
823 -- procedure P (..., Result : out Array_Typ) is
826 -- Result := Something;
830 Statements
(Handled_Statement_Sequence
(Func_Body
));
831 Replace_Returns
(Last_Entity
(Proc_Id
), Stmts
);
834 Make_Subprogram_Body
(Loc
,
836 Copy_Subprogram_Spec
(Specification
(Proc_Decl
)),
837 Declarations
=> Declarations
(Func_Body
),
838 Handled_Statement_Sequence
=>
839 Make_Handled_Sequence_Of_Statements
(Loc
,
840 Statements
=> Stmts
));
842 -- If the function is a generic instance, so is the new procedure.
843 -- Set flag accordingly so that the proper renaming declarations are
846 Set_Is_Generic_Instance
(Proc_Id
, Is_Generic_Instance
(Func_Id
));
848 end Build_Procedure_Body_Form
;
850 -----------------------
851 -- Caller_Known_Size --
852 -----------------------
854 function Caller_Known_Size
855 (Func_Call
: Node_Id
;
856 Result_Subt
: Entity_Id
) return Boolean
860 (Is_Definite_Subtype
(Underlying_Type
(Result_Subt
))
861 and then No
(Controlling_Argument
(Func_Call
)))
862 or else not Requires_Transient_Scope
(Underlying_Type
(Result_Subt
));
863 end Caller_Known_Size
;
865 --------------------------------
866 -- Check_Overriding_Operation --
867 --------------------------------
869 procedure Check_Overriding_Operation
(Subp
: Entity_Id
) is
870 Typ
: constant Entity_Id
:= Find_Dispatching_Type
(Subp
);
871 Op_List
: constant Elist_Id
:= Primitive_Operations
(Typ
);
877 if Is_Derived_Type
(Typ
)
878 and then not Is_Private_Type
(Typ
)
879 and then In_Open_Scopes
(Scope
(Etype
(Typ
)))
880 and then Is_Base_Type
(Typ
)
882 -- Subp overrides an inherited private operation if there is an
883 -- inherited operation with a different name than Subp (see
884 -- Derive_Subprogram) whose Alias is a hidden subprogram with the
885 -- same name as Subp.
887 Op_Elmt
:= First_Elmt
(Op_List
);
888 while Present
(Op_Elmt
) loop
889 Prim_Op
:= Node
(Op_Elmt
);
890 Par_Op
:= Alias
(Prim_Op
);
893 and then not Comes_From_Source
(Prim_Op
)
894 and then Chars
(Prim_Op
) /= Chars
(Par_Op
)
895 and then Chars
(Par_Op
) = Chars
(Subp
)
896 and then Is_Hidden
(Par_Op
)
897 and then Type_Conformant
(Prim_Op
, Subp
)
899 Set_DT_Position_Value
(Subp
, DT_Position
(Prim_Op
));
905 end Check_Overriding_Operation
;
907 -------------------------------
908 -- Detect_Infinite_Recursion --
909 -------------------------------
911 procedure Detect_Infinite_Recursion
(N
: Node_Id
; Spec
: Entity_Id
) is
912 Loc
: constant Source_Ptr
:= Sloc
(N
);
914 Var_List
: constant Elist_Id
:= New_Elmt_List
;
915 -- List of globals referenced by body of procedure
917 Call_List
: constant Elist_Id
:= New_Elmt_List
;
918 -- List of recursive calls in body of procedure
920 Shad_List
: constant Elist_Id
:= New_Elmt_List
;
921 -- List of entity id's for entities created to capture the value of
922 -- referenced globals on entry to the procedure.
924 Scop
: constant Uint
:= Scope_Depth
(Spec
);
925 -- This is used to record the scope depth of the current procedure, so
926 -- that we can identify global references.
928 Max_Vars
: constant := 4;
929 -- Do not test more than four global variables
931 Count_Vars
: Natural := 0;
932 -- Count variables found so far
944 function Process
(Nod
: Node_Id
) return Traverse_Result
;
945 -- Function to traverse the subprogram body (using Traverse_Func)
951 function Process
(Nod
: Node_Id
) return Traverse_Result
is
955 if Nkind
(Nod
) = N_Procedure_Call_Statement
then
957 -- Case of one of the detected recursive calls
959 if Is_Entity_Name
(Name
(Nod
))
960 and then Has_Recursive_Call
(Entity
(Name
(Nod
)))
961 and then Entity
(Name
(Nod
)) = Spec
963 Append_Elmt
(Nod
, Call_List
);
966 -- Any other procedure call may have side effects
972 -- A call to a pure function can always be ignored
974 elsif Nkind
(Nod
) = N_Function_Call
975 and then Is_Entity_Name
(Name
(Nod
))
976 and then Is_Pure
(Entity
(Name
(Nod
)))
980 -- Case of an identifier reference
982 elsif Nkind
(Nod
) = N_Identifier
then
985 -- If no entity, then ignore the reference
987 -- Not clear why this can happen. To investigate, remove this
988 -- test and look at the crash that occurs here in 3401-004 ???
993 -- Ignore entities with no Scope, again not clear how this
994 -- can happen, to investigate, look at 4108-008 ???
996 elsif No
(Scope
(Ent
)) then
999 -- Ignore the reference if not to a more global object
1001 elsif Scope_Depth
(Scope
(Ent
)) >= Scop
then
1004 -- References to types, exceptions and constants are always OK
1007 or else Ekind
(Ent
) = E_Exception
1008 or else Ekind
(Ent
) = E_Constant
1012 -- If other than a non-volatile scalar variable, we have some
1013 -- kind of global reference (e.g. to a function) that we cannot
1014 -- deal with so we forget the attempt.
1016 elsif Ekind
(Ent
) /= E_Variable
1017 or else not Is_Scalar_Type
(Etype
(Ent
))
1018 or else Treat_As_Volatile
(Ent
)
1022 -- Otherwise we have a reference to a global scalar
1025 -- Loop through global entities already detected
1027 Elm
:= First_Elmt
(Var_List
);
1029 -- If not detected before, record this new global reference
1032 Count_Vars
:= Count_Vars
+ 1;
1034 if Count_Vars
<= Max_Vars
then
1035 Append_Elmt
(Entity
(Nod
), Var_List
);
1042 -- If recorded before, ignore
1044 elsif Node
(Elm
) = Entity
(Nod
) then
1047 -- Otherwise keep looking
1057 -- For all other node kinds, recursively visit syntactic children
1064 function Traverse_Body
is new Traverse_Func
(Process
);
1066 -- Start of processing for Detect_Infinite_Recursion
1069 -- Do not attempt detection in No_Implicit_Conditional mode, since we
1070 -- won't be able to generate the code to handle the recursion in any
1073 if Restriction_Active
(No_Implicit_Conditionals
) then
1077 -- Otherwise do traversal and quit if we get abandon signal
1079 if Traverse_Body
(N
) = Abandon
then
1082 -- We must have a call, since Has_Recursive_Call was set. If not just
1083 -- ignore (this is only an error check, so if we have a funny situation,
1084 -- due to bugs or errors, we do not want to bomb).
1086 elsif Is_Empty_Elmt_List
(Call_List
) then
1090 -- Here is the case where we detect recursion at compile time
1092 -- Push our current scope for analyzing the declarations and code that
1093 -- we will insert for the checking.
1097 -- This loop builds temporary variables for each of the referenced
1098 -- globals, so that at the end of the loop the list Shad_List contains
1099 -- these temporaries in one-to-one correspondence with the elements in
1103 Elm
:= First_Elmt
(Var_List
);
1104 while Present
(Elm
) loop
1106 Ent
:= Make_Temporary
(Loc
, 'S');
1107 Append_Elmt
(Ent
, Shad_List
);
1109 -- Insert a declaration for this temporary at the start of the
1110 -- declarations for the procedure. The temporaries are declared as
1111 -- constant objects initialized to the current values of the
1112 -- corresponding temporaries.
1115 Make_Object_Declaration
(Loc
,
1116 Defining_Identifier
=> Ent
,
1117 Object_Definition
=> New_Occurrence_Of
(Etype
(Var
), Loc
),
1118 Constant_Present
=> True,
1119 Expression
=> New_Occurrence_Of
(Var
, Loc
));
1122 Prepend
(Decl
, Declarations
(N
));
1124 Insert_After
(Last
, Decl
);
1132 -- Loop through calls
1134 Call
:= First_Elmt
(Call_List
);
1135 while Present
(Call
) loop
1137 -- Build a predicate expression of the form
1140 -- and then global1 = temp1
1141 -- and then global2 = temp2
1144 -- This predicate determines if any of the global values
1145 -- referenced by the procedure have changed since the
1146 -- current call, if not an infinite recursion is assured.
1148 Test
:= New_Occurrence_Of
(Standard_True
, Loc
);
1150 Elm1
:= First_Elmt
(Var_List
);
1151 Elm2
:= First_Elmt
(Shad_List
);
1152 while Present
(Elm1
) loop
1158 Left_Opnd
=> New_Occurrence_Of
(Node
(Elm1
), Loc
),
1159 Right_Opnd
=> New_Occurrence_Of
(Node
(Elm2
), Loc
)));
1165 -- Now we replace the call with the sequence
1167 -- if no-changes (see above) then
1168 -- raise Storage_Error;
1173 Rewrite
(Node
(Call
),
1174 Make_If_Statement
(Loc
,
1176 Then_Statements
=> New_List
(
1177 Make_Raise_Storage_Error
(Loc
,
1178 Reason
=> SE_Infinite_Recursion
)),
1180 Else_Statements
=> New_List
(
1181 Relocate_Node
(Node
(Call
)))));
1183 Analyze
(Node
(Call
));
1188 -- Remove temporary scope stack entry used for analysis
1191 end Detect_Infinite_Recursion
;
1193 --------------------
1194 -- Expand_Actuals --
1195 --------------------
1197 procedure Expand_Actuals
1200 Post_Call
: out List_Id
)
1202 Loc
: constant Source_Ptr
:= Sloc
(N
);
1206 E_Actual
: Entity_Id
;
1207 E_Formal
: Entity_Id
;
1209 procedure Add_Call_By_Copy_Code
;
1210 -- For cases where the parameter must be passed by copy, this routine
1211 -- generates a temporary variable into which the actual is copied and
1212 -- then passes this as the parameter. For an OUT or IN OUT parameter,
1213 -- an assignment is also generated to copy the result back. The call
1214 -- also takes care of any constraint checks required for the type
1215 -- conversion case (on both the way in and the way out).
1217 procedure Add_Simple_Call_By_Copy_Code
;
1218 -- This is similar to the above, but is used in cases where we know
1219 -- that all that is needed is to simply create a temporary and copy
1220 -- the value in and out of the temporary.
1222 procedure Add_Validation_Call_By_Copy_Code
(Act
: Node_Id
);
1223 -- Perform copy-back for actual parameter Act which denotes a validation
1226 procedure Check_Fortran_Logical
;
1227 -- A value of type Logical that is passed through a formal parameter
1228 -- must be normalized because .TRUE. usually does not have the same
1229 -- representation as True. We assume that .FALSE. = False = 0.
1230 -- What about functions that return a logical type ???
1232 function Is_Legal_Copy
return Boolean;
1233 -- Check that an actual can be copied before generating the temporary
1234 -- to be used in the call. If the actual is of a by_reference type then
1235 -- the program is illegal (this can only happen in the presence of
1236 -- rep. clauses that force an incorrect alignment). If the formal is
1237 -- a by_reference parameter imposed by a DEC pragma, emit a warning to
1238 -- the effect that this might lead to unaligned arguments.
1240 function Make_Var
(Actual
: Node_Id
) return Entity_Id
;
1241 -- Returns an entity that refers to the given actual parameter, Actual
1242 -- (not including any type conversion). If Actual is an entity name,
1243 -- then this entity is returned unchanged, otherwise a renaming is
1244 -- created to provide an entity for the actual.
1246 procedure Reset_Packed_Prefix
;
1247 -- The expansion of a packed array component reference is delayed in
1248 -- the context of a call. Now we need to complete the expansion, so we
1249 -- unmark the analyzed bits in all prefixes.
1251 ---------------------------
1252 -- Add_Call_By_Copy_Code --
1253 ---------------------------
1255 procedure Add_Call_By_Copy_Code
is
1258 F_Typ
: Entity_Id
:= Etype
(Formal
);
1266 if not Is_Legal_Copy
then
1270 Temp
:= Make_Temporary
(Loc
, 'T', Actual
);
1272 -- Handle formals whose type comes from the limited view
1274 if From_Limited_With
(F_Typ
)
1275 and then Has_Non_Limited_View
(F_Typ
)
1277 F_Typ
:= Non_Limited_View
(F_Typ
);
1280 -- Use formal type for temp, unless formal type is an unconstrained
1281 -- array, in which case we don't have to worry about bounds checks,
1282 -- and we use the actual type, since that has appropriate bounds.
1284 if Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
) then
1285 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1287 Indic
:= New_Occurrence_Of
(F_Typ
, Loc
);
1290 if Nkind
(Actual
) = N_Type_Conversion
then
1291 V_Typ
:= Etype
(Expression
(Actual
));
1293 -- If the formal is an (in-)out parameter, capture the name
1294 -- of the variable in order to build the post-call assignment.
1296 Var
:= Make_Var
(Expression
(Actual
));
1298 Crep
:= not Same_Representation
1299 (F_Typ
, Etype
(Expression
(Actual
)));
1302 V_Typ
:= Etype
(Actual
);
1303 Var
:= Make_Var
(Actual
);
1307 -- Setup initialization for case of in out parameter, or an out
1308 -- parameter where the formal is an unconstrained array (in the
1309 -- latter case, we have to pass in an object with bounds).
1311 -- If this is an out parameter, the initial copy is wasteful, so as
1312 -- an optimization for the one-dimensional case we extract the
1313 -- bounds of the actual and build an uninitialized temporary of the
1316 if Ekind
(Formal
) = E_In_Out_Parameter
1317 or else (Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
))
1319 if Nkind
(Actual
) = N_Type_Conversion
then
1320 if Conversion_OK
(Actual
) then
1321 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1323 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1326 elsif Ekind
(Formal
) = E_Out_Parameter
1327 and then Is_Array_Type
(F_Typ
)
1328 and then Number_Dimensions
(F_Typ
) = 1
1329 and then not Has_Non_Null_Base_Init_Proc
(F_Typ
)
1331 -- Actual is a one-dimensional array or slice, and the type
1332 -- requires no initialization. Create a temporary of the
1333 -- right size, but do not copy actual into it (optimization).
1337 Make_Subtype_Indication
(Loc
,
1338 Subtype_Mark
=> New_Occurrence_Of
(F_Typ
, Loc
),
1340 Make_Index_Or_Discriminant_Constraint
(Loc
,
1341 Constraints
=> New_List
(
1344 Make_Attribute_Reference
(Loc
,
1345 Prefix
=> New_Occurrence_Of
(Var
, Loc
),
1346 Attribute_Name
=> Name_First
),
1348 Make_Attribute_Reference
(Loc
,
1349 Prefix
=> New_Occurrence_Of
(Var
, Loc
),
1350 Attribute_Name
=> Name_Last
)))));
1353 Init
:= New_Occurrence_Of
(Var
, Loc
);
1356 -- An initialization is created for packed conversions as
1357 -- actuals for out parameters to enable Make_Object_Declaration
1358 -- to determine the proper subtype for N_Node. Note that this
1359 -- is wasteful because the extra copying on the call side is
1360 -- not required for such out parameters. ???
1362 elsif Ekind
(Formal
) = E_Out_Parameter
1363 and then Nkind
(Actual
) = N_Type_Conversion
1364 and then (Is_Bit_Packed_Array
(F_Typ
)
1366 Is_Bit_Packed_Array
(Etype
(Expression
(Actual
))))
1368 if Conversion_OK
(Actual
) then
1369 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1371 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1374 elsif Ekind
(Formal
) = E_In_Parameter
then
1376 -- Handle the case in which the actual is a type conversion
1378 if Nkind
(Actual
) = N_Type_Conversion
then
1379 if Conversion_OK
(Actual
) then
1380 Init
:= OK_Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1382 Init
:= Convert_To
(F_Typ
, New_Occurrence_Of
(Var
, Loc
));
1385 Init
:= New_Occurrence_Of
(Var
, Loc
);
1393 Make_Object_Declaration
(Loc
,
1394 Defining_Identifier
=> Temp
,
1395 Object_Definition
=> Indic
,
1396 Expression
=> Init
);
1397 Set_Assignment_OK
(N_Node
);
1398 Insert_Action
(N
, N_Node
);
1400 -- Now, normally the deal here is that we use the defining
1401 -- identifier created by that object declaration. There is
1402 -- one exception to this. In the change of representation case
1403 -- the above declaration will end up looking like:
1405 -- temp : type := identifier;
1407 -- And in this case we might as well use the identifier directly
1408 -- and eliminate the temporary. Note that the analysis of the
1409 -- declaration was not a waste of time in that case, since it is
1410 -- what generated the necessary change of representation code. If
1411 -- the change of representation introduced additional code, as in
1412 -- a fixed-integer conversion, the expression is not an identifier
1413 -- and must be kept.
1416 and then Present
(Expression
(N_Node
))
1417 and then Is_Entity_Name
(Expression
(N_Node
))
1419 Temp
:= Entity
(Expression
(N_Node
));
1420 Rewrite
(N_Node
, Make_Null_Statement
(Loc
));
1423 -- For IN parameter, all we do is to replace the actual
1425 if Ekind
(Formal
) = E_In_Parameter
then
1426 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1429 -- Processing for OUT or IN OUT parameter
1432 -- Kill current value indications for the temporary variable we
1433 -- created, since we just passed it as an OUT parameter.
1435 Kill_Current_Values
(Temp
);
1436 Set_Is_Known_Valid
(Temp
, False);
1438 -- If type conversion, use reverse conversion on exit
1440 if Nkind
(Actual
) = N_Type_Conversion
then
1441 if Conversion_OK
(Actual
) then
1442 Expr
:= OK_Convert_To
(V_Typ
, New_Occurrence_Of
(Temp
, Loc
));
1444 Expr
:= Convert_To
(V_Typ
, New_Occurrence_Of
(Temp
, Loc
));
1447 Expr
:= New_Occurrence_Of
(Temp
, Loc
);
1450 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1453 -- If the actual is a conversion of a packed reference, it may
1454 -- already have been expanded by Remove_Side_Effects, and the
1455 -- resulting variable is a temporary which does not designate
1456 -- the proper out-parameter, which may not be addressable. In
1457 -- that case, generate an assignment to the original expression
1458 -- (before expansion of the packed reference) so that the proper
1459 -- expansion of assignment to a packed component can take place.
1466 if Is_Renaming_Of_Object
(Var
)
1467 and then Nkind
(Renamed_Object
(Var
)) = N_Selected_Component
1468 and then Nkind
(Original_Node
(Prefix
(Renamed_Object
(Var
))))
1469 = N_Indexed_Component
1471 Has_Non_Standard_Rep
(Etype
(Prefix
(Renamed_Object
(Var
))))
1473 Obj
:= Renamed_Object
(Var
);
1475 Make_Selected_Component
(Loc
,
1477 New_Copy_Tree
(Original_Node
(Prefix
(Obj
))),
1478 Selector_Name
=> New_Copy
(Selector_Name
(Obj
)));
1479 Reset_Analyzed_Flags
(Lhs
);
1482 Lhs
:= New_Occurrence_Of
(Var
, Loc
);
1485 Set_Assignment_OK
(Lhs
);
1487 if Is_Access_Type
(E_Formal
)
1488 and then Is_Entity_Name
(Lhs
)
1490 Present
(Effective_Extra_Accessibility
(Entity
(Lhs
)))
1492 -- Copyback target is an Ada 2012 stand-alone object of an
1493 -- anonymous access type.
1495 pragma Assert
(Ada_Version
>= Ada_2012
);
1497 if Type_Access_Level
(E_Formal
) >
1498 Object_Access_Level
(Lhs
)
1500 Append_To
(Post_Call
,
1501 Make_Raise_Program_Error
(Loc
,
1502 Reason
=> PE_Accessibility_Check_Failed
));
1505 Append_To
(Post_Call
,
1506 Make_Assignment_Statement
(Loc
,
1508 Expression
=> Expr
));
1510 -- We would like to somehow suppress generation of the
1511 -- extra_accessibility assignment generated by the expansion
1512 -- of the above assignment statement. It's not a correctness
1513 -- issue because the following assignment renders it dead,
1514 -- but generating back-to-back assignments to the same
1515 -- target is undesirable. ???
1517 Append_To
(Post_Call
,
1518 Make_Assignment_Statement
(Loc
,
1519 Name
=> New_Occurrence_Of
(
1520 Effective_Extra_Accessibility
(Entity
(Lhs
)), Loc
),
1521 Expression
=> Make_Integer_Literal
(Loc
,
1522 Type_Access_Level
(E_Formal
))));
1525 Append_To
(Post_Call
,
1526 Make_Assignment_Statement
(Loc
,
1528 Expression
=> Expr
));
1532 end Add_Call_By_Copy_Code
;
1534 ----------------------------------
1535 -- Add_Simple_Call_By_Copy_Code --
1536 ----------------------------------
1538 procedure Add_Simple_Call_By_Copy_Code
is
1540 F_Typ
: Entity_Id
:= Etype
(Formal
);
1549 if not Is_Legal_Copy
then
1553 -- Handle formals whose type comes from the limited view
1555 if From_Limited_With
(F_Typ
)
1556 and then Has_Non_Limited_View
(F_Typ
)
1558 F_Typ
:= Non_Limited_View
(F_Typ
);
1561 -- Use formal type for temp, unless formal type is an unconstrained
1562 -- array, in which case we don't have to worry about bounds checks,
1563 -- and we use the actual type, since that has appropriate bounds.
1565 if Is_Array_Type
(F_Typ
) and then not Is_Constrained
(F_Typ
) then
1566 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1568 Indic
:= New_Occurrence_Of
(F_Typ
, Loc
);
1571 -- Prepare to generate code
1573 Reset_Packed_Prefix
;
1575 Temp
:= Make_Temporary
(Loc
, 'T', Actual
);
1576 Incod
:= Relocate_Node
(Actual
);
1577 Outcod
:= New_Copy_Tree
(Incod
);
1579 -- Generate declaration of temporary variable, initializing it
1580 -- with the input parameter unless we have an OUT formal or
1581 -- this is an initialization call.
1583 -- If the formal is an out parameter with discriminants, the
1584 -- discriminants must be captured even if the rest of the object
1585 -- is in principle uninitialized, because the discriminants may
1586 -- be read by the called subprogram.
1588 if Ekind
(Formal
) = E_Out_Parameter
then
1591 if Has_Discriminants
(F_Typ
) then
1592 Indic
:= New_Occurrence_Of
(Etype
(Actual
), Loc
);
1595 elsif Inside_Init_Proc
then
1597 -- Could use a comment here to match comment below ???
1599 if Nkind
(Actual
) /= N_Selected_Component
1601 not Has_Discriminant_Dependent_Constraint
1602 (Entity
(Selector_Name
(Actual
)))
1606 -- Otherwise, keep the component in order to generate the proper
1607 -- actual subtype, that depends on enclosing discriminants.
1615 Make_Object_Declaration
(Loc
,
1616 Defining_Identifier
=> Temp
,
1617 Object_Definition
=> Indic
,
1618 Expression
=> Incod
);
1623 -- If the call is to initialize a component of a composite type,
1624 -- and the component does not depend on discriminants, use the
1625 -- actual type of the component. This is required in case the
1626 -- component is constrained, because in general the formal of the
1627 -- initialization procedure will be unconstrained. Note that if
1628 -- the component being initialized is constrained by an enclosing
1629 -- discriminant, the presence of the initialization in the
1630 -- declaration will generate an expression for the actual subtype.
1632 Set_No_Initialization
(Decl
);
1633 Set_Object_Definition
(Decl
,
1634 New_Occurrence_Of
(Etype
(Actual
), Loc
));
1637 Insert_Action
(N
, Decl
);
1639 -- The actual is simply a reference to the temporary
1641 Rewrite
(Actual
, New_Occurrence_Of
(Temp
, Loc
));
1643 -- Generate copy out if OUT or IN OUT parameter
1645 if Ekind
(Formal
) /= E_In_Parameter
then
1647 Rhs
:= New_Occurrence_Of
(Temp
, Loc
);
1649 -- Deal with conversion
1651 if Nkind
(Lhs
) = N_Type_Conversion
then
1652 Lhs
:= Expression
(Lhs
);
1653 Rhs
:= Convert_To
(Etype
(Actual
), Rhs
);
1656 Append_To
(Post_Call
,
1657 Make_Assignment_Statement
(Loc
,
1659 Expression
=> Rhs
));
1660 Set_Assignment_OK
(Name
(Last
(Post_Call
)));
1662 end Add_Simple_Call_By_Copy_Code
;
1664 --------------------------------------
1665 -- Add_Validation_Call_By_Copy_Code --
1666 --------------------------------------
1668 procedure Add_Validation_Call_By_Copy_Code
(Act
: Node_Id
) is
1671 Obj_Typ
: Entity_Id
;
1672 Var
: constant Node_Id
:= Unqual_Conv
(Act
);
1676 -- Copy the value of the validation variable back into the object
1679 if Is_Entity_Name
(Var
) then
1680 Var_Id
:= Entity
(Var
);
1681 Obj
:= Validated_Object
(Var_Id
);
1682 Obj_Typ
:= Etype
(Obj
);
1684 Expr
:= New_Occurrence_Of
(Var_Id
, Loc
);
1686 -- A type conversion is needed when the validation variable and
1687 -- the validated object carry different types. This case occurs
1688 -- when the actual is qualified in some fashion.
1691 -- subtype Int is Integer range ...;
1692 -- procedure Call (Val : in out Integer);
1696 -- Call (Integer (Object));
1700 -- Var : Integer := Object; -- conversion to base type
1701 -- if not Var'Valid then -- validity check
1702 -- Call (Var); -- modify Var
1703 -- Object := Int (Var); -- conversion to subtype
1705 if Etype
(Var_Id
) /= Obj_Typ
then
1707 Make_Type_Conversion
(Loc
,
1708 Subtype_Mark
=> New_Occurrence_Of
(Obj_Typ
, Loc
),
1709 Expression
=> Expr
);
1715 -- Object := Object_Type (Var);
1717 Append_To
(Post_Call
,
1718 Make_Assignment_Statement
(Loc
,
1720 Expression
=> Expr
));
1722 -- If the flow reaches this point, then this routine was invoked with
1723 -- an actual which does not denote a validation variable.
1726 pragma Assert
(False);
1729 end Add_Validation_Call_By_Copy_Code
;
1731 ---------------------------
1732 -- Check_Fortran_Logical --
1733 ---------------------------
1735 procedure Check_Fortran_Logical
is
1736 Logical
: constant Entity_Id
:= Etype
(Formal
);
1739 -- Note: this is very incomplete, e.g. it does not handle arrays
1740 -- of logical values. This is really not the right approach at all???)
1743 if Convention
(Subp
) = Convention_Fortran
1744 and then Root_Type
(Etype
(Formal
)) = Standard_Boolean
1745 and then Ekind
(Formal
) /= E_In_Parameter
1747 Var
:= Make_Var
(Actual
);
1748 Append_To
(Post_Call
,
1749 Make_Assignment_Statement
(Loc
,
1750 Name
=> New_Occurrence_Of
(Var
, Loc
),
1752 Unchecked_Convert_To
(
1755 Left_Opnd
=> New_Occurrence_Of
(Var
, Loc
),
1757 Unchecked_Convert_To
(
1759 New_Occurrence_Of
(Standard_False
, Loc
))))));
1761 end Check_Fortran_Logical
;
1767 function Is_Legal_Copy
return Boolean is
1769 -- An attempt to copy a value of such a type can only occur if
1770 -- representation clauses give the actual a misaligned address.
1772 if Is_By_Reference_Type
(Etype
(Formal
)) then
1774 -- The actual may in fact be properly aligned but there is not
1775 -- enough front-end information to determine this. In that case
1776 -- gigi will emit an error if a copy is not legal, or generate
1781 -- For users of Starlet, we assume that the specification of by-
1782 -- reference mechanism is mandatory. This may lead to unaligned
1783 -- objects but at least for DEC legacy code it is known to work.
1784 -- The warning will alert users of this code that a problem may
1787 elsif Mechanism
(Formal
) = By_Reference
1788 and then Is_Valued_Procedure
(Scope
(Formal
))
1791 ("by_reference actual may be misaligned??", Actual
);
1803 function Make_Var
(Actual
: Node_Id
) return Entity_Id
is
1807 if Is_Entity_Name
(Actual
) then
1808 return Entity
(Actual
);
1811 Var
:= Make_Temporary
(Loc
, 'T', Actual
);
1814 Make_Object_Renaming_Declaration
(Loc
,
1815 Defining_Identifier
=> Var
,
1817 New_Occurrence_Of
(Etype
(Actual
), Loc
),
1818 Name
=> Relocate_Node
(Actual
));
1820 Insert_Action
(N
, N_Node
);
1825 -------------------------
1826 -- Reset_Packed_Prefix --
1827 -------------------------
1829 procedure Reset_Packed_Prefix
is
1830 Pfx
: Node_Id
:= Actual
;
1833 Set_Analyzed
(Pfx
, False);
1835 not Nkind_In
(Pfx
, N_Selected_Component
, N_Indexed_Component
);
1836 Pfx
:= Prefix
(Pfx
);
1838 end Reset_Packed_Prefix
;
1840 -- Start of processing for Expand_Actuals
1843 Post_Call
:= New_List
;
1845 Formal
:= First_Formal
(Subp
);
1846 Actual
:= First_Actual
(N
);
1847 while Present
(Formal
) loop
1848 E_Formal
:= Etype
(Formal
);
1849 E_Actual
:= Etype
(Actual
);
1851 -- Handle formals whose type comes from the limited view
1853 if From_Limited_With
(E_Formal
)
1854 and then Has_Non_Limited_View
(E_Formal
)
1856 E_Formal
:= Non_Limited_View
(E_Formal
);
1859 if Is_Scalar_Type
(E_Formal
)
1860 or else Nkind
(Actual
) = N_Slice
1862 Check_Fortran_Logical
;
1866 elsif Ekind
(Formal
) /= E_Out_Parameter
then
1868 -- The unusual case of the current instance of a protected type
1869 -- requires special handling. This can only occur in the context
1870 -- of a call within the body of a protected operation.
1872 if Is_Entity_Name
(Actual
)
1873 and then Ekind
(Entity
(Actual
)) = E_Protected_Type
1874 and then In_Open_Scopes
(Entity
(Actual
))
1876 if Scope
(Subp
) /= Entity
(Actual
) then
1878 ("operation outside protected type may not "
1879 & "call back its protected operations??", Actual
);
1883 Expand_Protected_Object_Reference
(N
, Entity
(Actual
)));
1886 -- Ada 2005 (AI-318-02): If the actual parameter is a call to a
1887 -- build-in-place function, then a temporary return object needs
1888 -- to be created and access to it must be passed to the function.
1889 -- Currently we limit such functions to those with inherently
1890 -- limited result subtypes, but eventually we plan to expand the
1891 -- functions that are treated as build-in-place to include other
1892 -- composite result types.
1894 if Is_Build_In_Place_Function_Call
(Actual
) then
1895 Make_Build_In_Place_Call_In_Anonymous_Context
(Actual
);
1897 -- Ada 2005 (AI-318-02): Specialization of the previous case for
1898 -- actuals containing build-in-place function calls whose returned
1899 -- object covers interface types.
1901 elsif Present
(Unqual_BIP_Iface_Function_Call
(Actual
)) then
1902 Make_Build_In_Place_Iface_Call_In_Anonymous_Context
(Actual
);
1905 Apply_Constraint_Check
(Actual
, E_Formal
);
1907 -- Out parameter case. No constraint checks on access type
1910 elsif Is_Access_Type
(E_Formal
) then
1915 elsif Has_Discriminants
(Base_Type
(E_Formal
))
1916 or else Has_Non_Null_Base_Init_Proc
(E_Formal
)
1918 Apply_Constraint_Check
(Actual
, E_Formal
);
1923 Apply_Constraint_Check
(Actual
, Base_Type
(E_Formal
));
1926 -- Processing for IN-OUT and OUT parameters
1928 if Ekind
(Formal
) /= E_In_Parameter
then
1930 -- For type conversions of arrays, apply length/range checks
1932 if Is_Array_Type
(E_Formal
)
1933 and then Nkind
(Actual
) = N_Type_Conversion
1935 if Is_Constrained
(E_Formal
) then
1936 Apply_Length_Check
(Expression
(Actual
), E_Formal
);
1938 Apply_Range_Check
(Expression
(Actual
), E_Formal
);
1942 -- The actual denotes a variable which captures the value of an
1943 -- object for validation purposes. Add a copy-back to reflect any
1944 -- potential changes in value back into the original object.
1946 -- Var : ... := Object;
1947 -- if not Var'Valid then -- validity check
1948 -- Call (Var); -- modify var
1949 -- Object := Var; -- update Object
1951 -- This case is given higher priority because the subsequent check
1952 -- for type conversion may add an extra copy of the variable and
1953 -- prevent proper value propagation back in the original object.
1955 if Is_Validation_Variable_Reference
(Actual
) then
1956 Add_Validation_Call_By_Copy_Code
(Actual
);
1958 -- If argument is a type conversion for a type that is passed by
1959 -- copy, then we must pass the parameter by copy.
1961 elsif Nkind
(Actual
) = N_Type_Conversion
1963 (Is_Numeric_Type
(E_Formal
)
1964 or else Is_Access_Type
(E_Formal
)
1965 or else Is_Enumeration_Type
(E_Formal
)
1966 or else Is_Bit_Packed_Array
(Etype
(Formal
))
1967 or else Is_Bit_Packed_Array
(Etype
(Expression
(Actual
)))
1969 -- Also pass by copy if change of representation
1971 or else not Same_Representation
1973 Etype
(Expression
(Actual
))))
1975 Add_Call_By_Copy_Code
;
1977 -- References to components of bit-packed arrays are expanded
1978 -- at this point, rather than at the point of analysis of the
1979 -- actuals, to handle the expansion of the assignment to
1980 -- [in] out parameters.
1982 elsif Is_Ref_To_Bit_Packed_Array
(Actual
) then
1983 Add_Simple_Call_By_Copy_Code
;
1985 -- If a non-scalar actual is possibly bit-aligned, we need a copy
1986 -- because the back-end cannot cope with such objects. In other
1987 -- cases where alignment forces a copy, the back-end generates
1988 -- it properly. It should not be generated unconditionally in the
1989 -- front-end because it does not know precisely the alignment
1990 -- requirements of the target, and makes too conservative an
1991 -- estimate, leading to superfluous copies or spurious errors
1992 -- on by-reference parameters.
1994 elsif Nkind
(Actual
) = N_Selected_Component
1996 Component_May_Be_Bit_Aligned
(Entity
(Selector_Name
(Actual
)))
1997 and then not Represented_As_Scalar
(Etype
(Formal
))
1999 Add_Simple_Call_By_Copy_Code
;
2001 -- References to slices of bit-packed arrays are expanded
2003 elsif Is_Ref_To_Bit_Packed_Slice
(Actual
) then
2004 Add_Call_By_Copy_Code
;
2006 -- References to possibly unaligned slices of arrays are expanded
2008 elsif Is_Possibly_Unaligned_Slice
(Actual
) then
2009 Add_Call_By_Copy_Code
;
2011 -- Deal with access types where the actual subtype and the
2012 -- formal subtype are not the same, requiring a check.
2014 -- It is necessary to exclude tagged types because of "downward
2015 -- conversion" errors.
2017 elsif Is_Access_Type
(E_Formal
)
2018 and then not Same_Type
(E_Formal
, E_Actual
)
2019 and then not Is_Tagged_Type
(Designated_Type
(E_Formal
))
2021 Add_Call_By_Copy_Code
;
2023 -- If the actual is not a scalar and is marked for volatile
2024 -- treatment, whereas the formal is not volatile, then pass
2025 -- by copy unless it is a by-reference type.
2027 -- Note: we use Is_Volatile here rather than Treat_As_Volatile,
2028 -- because this is the enforcement of a language rule that applies
2029 -- only to "real" volatile variables, not e.g. to the address
2030 -- clause overlay case.
2032 elsif Is_Entity_Name
(Actual
)
2033 and then Is_Volatile
(Entity
(Actual
))
2034 and then not Is_By_Reference_Type
(E_Actual
)
2035 and then not Is_Scalar_Type
(Etype
(Entity
(Actual
)))
2036 and then not Is_Volatile
(E_Formal
)
2038 Add_Call_By_Copy_Code
;
2040 elsif Nkind
(Actual
) = N_Indexed_Component
2041 and then Is_Entity_Name
(Prefix
(Actual
))
2042 and then Has_Volatile_Components
(Entity
(Prefix
(Actual
)))
2044 Add_Call_By_Copy_Code
;
2046 -- Add call-by-copy code for the case of scalar out parameters
2047 -- when it is not known at compile time that the subtype of the
2048 -- formal is a subrange of the subtype of the actual (or vice
2049 -- versa for in out parameters), in order to get range checks
2050 -- on such actuals. (Maybe this case should be handled earlier
2051 -- in the if statement???)
2053 elsif Is_Scalar_Type
(E_Formal
)
2055 (not In_Subrange_Of
(E_Formal
, E_Actual
)
2057 (Ekind
(Formal
) = E_In_Out_Parameter
2058 and then not In_Subrange_Of
(E_Actual
, E_Formal
)))
2060 -- Perhaps the setting back to False should be done within
2061 -- Add_Call_By_Copy_Code, since it could get set on other
2062 -- cases occurring above???
2064 if Do_Range_Check
(Actual
) then
2065 Set_Do_Range_Check
(Actual
, False);
2068 Add_Call_By_Copy_Code
;
2071 -- RM 3.2.4 (23/3): A predicate is checked on in-out and out
2072 -- by-reference parameters on exit from the call. If the actual
2073 -- is a derived type and the operation is inherited, the body
2074 -- of the operation will not contain a call to the predicate
2075 -- function, so it must be done explicitly after the call. Ditto
2076 -- if the actual is an entity of a predicated subtype.
2078 -- The rule refers to by-reference types, but a check is needed
2079 -- for by-copy types as well. That check is subsumed by the rule
2080 -- for subtype conversion on assignment, but we can generate the
2081 -- required check now.
2083 -- Note also that Subp may be either a subprogram entity for
2084 -- direct calls, or a type entity for indirect calls, which must
2085 -- be handled separately because the name does not denote an
2086 -- overloadable entity.
2088 By_Ref_Predicate_Check
: declare
2089 Aund
: constant Entity_Id
:= Underlying_Type
(E_Actual
);
2092 function Is_Public_Subp
return Boolean;
2093 -- Check whether the subprogram being called is a visible
2094 -- operation of the type of the actual. Used to determine
2095 -- whether an invariant check must be generated on the
2098 ---------------------
2099 -- Is_Public_Subp --
2100 ---------------------
2102 function Is_Public_Subp
return Boolean is
2103 Pack
: constant Entity_Id
:= Scope
(Subp
);
2104 Subp_Decl
: Node_Id
;
2107 if not Is_Subprogram
(Subp
) then
2110 -- The operation may be inherited, or a primitive of the
2114 Nkind_In
(Parent
(Subp
), N_Private_Extension_Declaration
,
2115 N_Full_Type_Declaration
)
2117 Subp_Decl
:= Parent
(Subp
);
2120 Subp_Decl
:= Unit_Declaration_Node
(Subp
);
2123 return Ekind
(Pack
) = E_Package
2125 List_Containing
(Subp_Decl
) =
2126 Visible_Declarations
2127 (Specification
(Unit_Declaration_Node
(Pack
)));
2130 -- Start of processing for By_Ref_Predicate_Check
2139 if Has_Predicates
(Atyp
)
2140 and then Present
(Predicate_Function
(Atyp
))
2142 -- Skip predicate checks for special cases
2144 and then Predicate_Tests_On_Arguments
(Subp
)
2146 Append_To
(Post_Call
,
2147 Make_Predicate_Check
(Atyp
, Actual
));
2150 -- We generated caller-side invariant checks in two cases:
2152 -- a) when calling an inherited operation, where there is an
2153 -- implicit view conversion of the actual to the parent type.
2155 -- b) When the conversion is explicit
2157 -- We treat these cases separately because the required
2158 -- conversion for a) is added later when expanding the call.
2160 if Has_Invariants
(Etype
(Actual
))
2162 Nkind
(Parent
(Subp
)) = N_Private_Extension_Declaration
2164 if Comes_From_Source
(N
) and then Is_Public_Subp
then
2165 Append_To
(Post_Call
, Make_Invariant_Call
(Actual
));
2168 elsif Nkind
(Actual
) = N_Type_Conversion
2169 and then Has_Invariants
(Etype
(Expression
(Actual
)))
2171 if Comes_From_Source
(N
) and then Is_Public_Subp
then
2172 Append_To
(Post_Call
,
2173 Make_Invariant_Call
(Expression
(Actual
)));
2176 end By_Ref_Predicate_Check
;
2178 -- Processing for IN parameters
2181 -- For IN parameters in the bit-packed array case, we expand an
2182 -- indexed component (the circuit in Exp_Ch4 deliberately left
2183 -- indexed components appearing as actuals untouched, so that
2184 -- the special processing above for the OUT and IN OUT cases
2185 -- could be performed. We could make the test in Exp_Ch4 more
2186 -- complex and have it detect the parameter mode, but it is
2187 -- easier simply to handle all cases here.)
2189 if Nkind
(Actual
) = N_Indexed_Component
2190 and then Is_Bit_Packed_Array
(Etype
(Prefix
(Actual
)))
2192 Reset_Packed_Prefix
;
2193 Expand_Packed_Element_Reference
(Actual
);
2195 -- If we have a reference to a bit-packed array, we copy it, since
2196 -- the actual must be byte aligned.
2198 -- Is this really necessary in all cases???
2200 elsif Is_Ref_To_Bit_Packed_Array
(Actual
) then
2201 Add_Simple_Call_By_Copy_Code
;
2203 -- If a non-scalar actual is possibly unaligned, we need a copy
2205 elsif Is_Possibly_Unaligned_Object
(Actual
)
2206 and then not Represented_As_Scalar
(Etype
(Formal
))
2208 Add_Simple_Call_By_Copy_Code
;
2210 -- Similarly, we have to expand slices of packed arrays here
2211 -- because the result must be byte aligned.
2213 elsif Is_Ref_To_Bit_Packed_Slice
(Actual
) then
2214 Add_Call_By_Copy_Code
;
2216 -- Only processing remaining is to pass by copy if this is a
2217 -- reference to a possibly unaligned slice, since the caller
2218 -- expects an appropriately aligned argument.
2220 elsif Is_Possibly_Unaligned_Slice
(Actual
) then
2221 Add_Call_By_Copy_Code
;
2223 -- An unusual case: a current instance of an enclosing task can be
2224 -- an actual, and must be replaced by a reference to self.
2226 elsif Is_Entity_Name
(Actual
)
2227 and then Is_Task_Type
(Entity
(Actual
))
2229 if In_Open_Scopes
(Entity
(Actual
)) then
2231 (Make_Function_Call
(Loc
,
2232 Name
=> New_Occurrence_Of
(RTE
(RE_Self
), Loc
))));
2235 -- A task type cannot otherwise appear as an actual
2238 raise Program_Error
;
2243 Next_Formal
(Formal
);
2244 Next_Actual
(Actual
);
2252 procedure Expand_Call
(N
: Node_Id
) is
2253 Post_Call
: List_Id
;
2255 Expand_Call_Helper
(N
, Post_Call
);
2256 Insert_Post_Call_Actions
(N
, Post_Call
);
2259 ------------------------
2260 -- Expand_Call_Helper --
2261 ------------------------
2263 -- This procedure handles expansion of function calls and procedure call
2264 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
2265 -- Expand_N_Procedure_Call_Statement). Processing for calls includes:
2267 -- Replace call to Raise_Exception by Raise_Exception_Always if possible
2268 -- Provide values of actuals for all formals in Extra_Formals list
2269 -- Replace "call" to enumeration literal function by literal itself
2270 -- Rewrite call to predefined operator as operator
2271 -- Replace actuals to in-out parameters that are numeric conversions,
2272 -- with explicit assignment to temporaries before and after the call.
2274 -- Note that the list of actuals has been filled with default expressions
2275 -- during semantic analysis of the call. Only the extra actuals required
2276 -- for the 'Constrained attribute and for accessibility checks are added
2279 procedure Expand_Call_Helper
(N
: Node_Id
; Post_Call
: out List_Id
) is
2280 Loc
: constant Source_Ptr
:= Sloc
(N
);
2281 Call_Node
: Node_Id
:= N
;
2282 Extra_Actuals
: List_Id
:= No_List
;
2283 Prev
: Node_Id
:= Empty
;
2285 procedure Add_Actual_Parameter
(Insert_Param
: Node_Id
);
2286 -- Adds one entry to the end of the actual parameter list. Used for
2287 -- default parameters and for extra actuals (for Extra_Formals). The
2288 -- argument is an N_Parameter_Association node.
2290 procedure Add_Extra_Actual
(Expr
: Node_Id
; EF
: Entity_Id
);
2291 -- Adds an extra actual to the list of extra actuals. Expr is the
2292 -- expression for the value of the actual, EF is the entity for the
2295 procedure Add_View_Conversion_Invariants
2296 (Formal
: Entity_Id
;
2298 -- Adds invariant checks for every intermediate type between the range
2299 -- of a view converted argument to its ancestor (from parent to child).
2301 function Inherited_From_Formal
(S
: Entity_Id
) return Entity_Id
;
2302 -- Within an instance, a type derived from an untagged formal derived
2303 -- type inherits from the original parent, not from the actual. The
2304 -- current derivation mechanism has the derived type inherit from the
2305 -- actual, which is only correct outside of the instance. If the
2306 -- subprogram is inherited, we test for this particular case through a
2307 -- convoluted tree traversal before setting the proper subprogram to be
2310 function In_Unfrozen_Instance
(E
: Entity_Id
) return Boolean;
2311 -- Return true if E comes from an instance that is not yet frozen
2313 function Is_Direct_Deep_Call
(Subp
: Entity_Id
) return Boolean;
2314 -- Determine if Subp denotes a non-dispatching call to a Deep routine
2316 function New_Value
(From
: Node_Id
) return Node_Id
;
2317 -- From is the original Expression. New_Value is equivalent to a call
2318 -- to Duplicate_Subexpr with an explicit dereference when From is an
2319 -- access parameter.
2321 --------------------------
2322 -- Add_Actual_Parameter --
2323 --------------------------
2325 procedure Add_Actual_Parameter
(Insert_Param
: Node_Id
) is
2326 Actual_Expr
: constant Node_Id
:=
2327 Explicit_Actual_Parameter
(Insert_Param
);
2330 -- Case of insertion is first named actual
2332 if No
(Prev
) or else
2333 Nkind
(Parent
(Prev
)) /= N_Parameter_Association
2335 Set_Next_Named_Actual
2336 (Insert_Param
, First_Named_Actual
(Call_Node
));
2337 Set_First_Named_Actual
(Call_Node
, Actual_Expr
);
2340 if No
(Parameter_Associations
(Call_Node
)) then
2341 Set_Parameter_Associations
(Call_Node
, New_List
);
2344 Append
(Insert_Param
, Parameter_Associations
(Call_Node
));
2347 Insert_After
(Prev
, Insert_Param
);
2350 -- Case of insertion is not first named actual
2353 Set_Next_Named_Actual
2354 (Insert_Param
, Next_Named_Actual
(Parent
(Prev
)));
2355 Set_Next_Named_Actual
(Parent
(Prev
), Actual_Expr
);
2356 Append
(Insert_Param
, Parameter_Associations
(Call_Node
));
2359 Prev
:= Actual_Expr
;
2360 end Add_Actual_Parameter
;
2362 ----------------------
2363 -- Add_Extra_Actual --
2364 ----------------------
2366 procedure Add_Extra_Actual
(Expr
: Node_Id
; EF
: Entity_Id
) is
2367 Loc
: constant Source_Ptr
:= Sloc
(Expr
);
2370 if Extra_Actuals
= No_List
then
2371 Extra_Actuals
:= New_List
;
2372 Set_Parent
(Extra_Actuals
, Call_Node
);
2375 Append_To
(Extra_Actuals
,
2376 Make_Parameter_Association
(Loc
,
2377 Selector_Name
=> New_Occurrence_Of
(EF
, Loc
),
2378 Explicit_Actual_Parameter
=> Expr
));
2380 Analyze_And_Resolve
(Expr
, Etype
(EF
));
2382 if Nkind
(Call_Node
) = N_Function_Call
then
2383 Set_Is_Accessibility_Actual
(Parent
(Expr
));
2385 end Add_Extra_Actual
;
2387 ------------------------------------
2388 -- Add_View_Conversion_Invariants --
2389 ------------------------------------
2391 procedure Add_View_Conversion_Invariants
2392 (Formal
: Entity_Id
;
2396 Curr_Typ
: Entity_Id
;
2397 Inv_Checks
: List_Id
;
2398 Par_Typ
: Entity_Id
;
2401 Inv_Checks
:= No_List
;
2403 -- Extract the argument from a potentially nested set of view
2407 while Nkind
(Arg
) = N_Type_Conversion
loop
2408 Arg
:= Expression
(Arg
);
2411 -- Move up the derivation chain starting with the type of the formal
2412 -- parameter down to the type of the actual object.
2415 Par_Typ
:= Etype
(Arg
);
2416 while Par_Typ
/= Etype
(Formal
) and Par_Typ
/= Curr_Typ
loop
2417 Curr_Typ
:= Par_Typ
;
2419 if Has_Invariants
(Curr_Typ
)
2420 and then Present
(Invariant_Procedure
(Curr_Typ
))
2422 -- Verify the invariate of the current type. Generate:
2424 -- <Curr_Typ>Invariant (Curr_Typ (Arg));
2426 Prepend_New_To
(Inv_Checks
,
2427 Make_Procedure_Call_Statement
(Loc
,
2430 (Invariant_Procedure
(Curr_Typ
), Loc
),
2431 Parameter_Associations
=> New_List
(
2432 Make_Type_Conversion
(Loc
,
2433 Subtype_Mark
=> New_Occurrence_Of
(Curr_Typ
, Loc
),
2434 Expression
=> New_Copy_Tree
(Arg
)))));
2437 Par_Typ
:= Base_Type
(Etype
(Curr_Typ
));
2440 if not Is_Empty_List
(Inv_Checks
) then
2441 Insert_Actions_After
(N
, Inv_Checks
);
2443 end Add_View_Conversion_Invariants
;
2445 ---------------------------
2446 -- Inherited_From_Formal --
2447 ---------------------------
2449 function Inherited_From_Formal
(S
: Entity_Id
) return Entity_Id
is
2451 Gen_Par
: Entity_Id
;
2452 Gen_Prim
: Elist_Id
;
2457 -- If the operation is inherited, it is attached to the corresponding
2458 -- type derivation. If the parent in the derivation is a generic
2459 -- actual, it is a subtype of the actual, and we have to recover the
2460 -- original derived type declaration to find the proper parent.
2462 if Nkind
(Parent
(S
)) /= N_Full_Type_Declaration
2463 or else not Is_Derived_Type
(Defining_Identifier
(Parent
(S
)))
2464 or else Nkind
(Type_Definition
(Original_Node
(Parent
(S
)))) /=
2465 N_Derived_Type_Definition
2466 or else not In_Instance
2473 (Type_Definition
(Original_Node
(Parent
(S
))));
2475 if Nkind
(Indic
) = N_Subtype_Indication
then
2476 Par
:= Entity
(Subtype_Mark
(Indic
));
2478 Par
:= Entity
(Indic
);
2482 if not Is_Generic_Actual_Type
(Par
)
2483 or else Is_Tagged_Type
(Par
)
2484 or else Nkind
(Parent
(Par
)) /= N_Subtype_Declaration
2485 or else not In_Open_Scopes
(Scope
(Par
))
2489 Gen_Par
:= Generic_Parent_Type
(Parent
(Par
));
2492 -- If the actual has no generic parent type, the formal is not
2493 -- a formal derived type, so nothing to inherit.
2495 if No
(Gen_Par
) then
2499 -- If the generic parent type is still the generic type, this is a
2500 -- private formal, not a derived formal, and there are no operations
2501 -- inherited from the formal.
2503 if Nkind
(Parent
(Gen_Par
)) = N_Formal_Type_Declaration
then
2507 Gen_Prim
:= Collect_Primitive_Operations
(Gen_Par
);
2509 Elmt
:= First_Elmt
(Gen_Prim
);
2510 while Present
(Elmt
) loop
2511 if Chars
(Node
(Elmt
)) = Chars
(S
) then
2517 F1
:= First_Formal
(S
);
2518 F2
:= First_Formal
(Node
(Elmt
));
2520 and then Present
(F2
)
2522 if Etype
(F1
) = Etype
(F2
)
2523 or else Etype
(F2
) = Gen_Par
2529 exit; -- not the right subprogram
2541 raise Program_Error
;
2542 end Inherited_From_Formal
;
2544 --------------------------
2545 -- In_Unfrozen_Instance --
2546 --------------------------
2548 function In_Unfrozen_Instance
(E
: Entity_Id
) return Boolean is
2553 while Present
(S
) and then S
/= Standard_Standard
loop
2554 if Is_Generic_Instance
(S
)
2555 and then Present
(Freeze_Node
(S
))
2556 and then not Analyzed
(Freeze_Node
(S
))
2565 end In_Unfrozen_Instance
;
2567 -------------------------
2568 -- Is_Direct_Deep_Call --
2569 -------------------------
2571 function Is_Direct_Deep_Call
(Subp
: Entity_Id
) return Boolean is
2573 if Is_TSS
(Subp
, TSS_Deep_Adjust
)
2574 or else Is_TSS
(Subp
, TSS_Deep_Finalize
)
2575 or else Is_TSS
(Subp
, TSS_Deep_Initialize
)
2582 Actual
:= First
(Parameter_Associations
(N
));
2583 Formal
:= First_Formal
(Subp
);
2584 while Present
(Actual
)
2585 and then Present
(Formal
)
2587 if Nkind
(Actual
) = N_Identifier
2588 and then Is_Controlling_Actual
(Actual
)
2589 and then Etype
(Actual
) = Etype
(Formal
)
2595 Next_Formal
(Formal
);
2601 end Is_Direct_Deep_Call
;
2607 function New_Value
(From
: Node_Id
) return Node_Id
is
2608 Res
: constant Node_Id
:= Duplicate_Subexpr
(From
);
2610 if Is_Access_Type
(Etype
(From
)) then
2611 return Make_Explicit_Dereference
(Sloc
(From
), Prefix
=> Res
);
2619 Remote
: constant Boolean := Is_Remote_Call
(Call_Node
);
2622 Orig_Subp
: Entity_Id
:= Empty
;
2623 Param_Count
: Natural := 0;
2624 Parent_Formal
: Entity_Id
;
2625 Parent_Subp
: Entity_Id
;
2626 Pref_Entity
: Entity_Id
;
2630 Prev_Orig
: Node_Id
;
2631 -- Original node for an actual, which may have been rewritten. If the
2632 -- actual is a function call that has been transformed from a selected
2633 -- component, the original node is unanalyzed. Otherwise, it carries
2634 -- semantic information used to generate additional actuals.
2636 CW_Interface_Formals_Present
: Boolean := False;
2638 -- Start of processing for Expand_Call_Helper
2641 Post_Call
:= New_List
;
2643 -- Expand the function or procedure call if the first actual has a
2644 -- declared dimension aspect, and the subprogram is declared in one
2645 -- of the dimension I/O packages.
2647 if Ada_Version
>= Ada_2012
2649 Nkind_In
(Call_Node
, N_Procedure_Call_Statement
, N_Function_Call
)
2650 and then Present
(Parameter_Associations
(Call_Node
))
2652 Expand_Put_Call_With_Symbol
(Call_Node
);
2655 -- Ignore if previous error
2657 if Nkind
(Call_Node
) in N_Has_Etype
2658 and then Etype
(Call_Node
) = Any_Type
2663 -- Call using access to subprogram with explicit dereference
2665 if Nkind
(Name
(Call_Node
)) = N_Explicit_Dereference
then
2666 Subp
:= Etype
(Name
(Call_Node
));
2667 Parent_Subp
:= Empty
;
2669 -- Case of call to simple entry, where the Name is a selected component
2670 -- whose prefix is the task, and whose selector name is the entry name
2672 elsif Nkind
(Name
(Call_Node
)) = N_Selected_Component
then
2673 Subp
:= Entity
(Selector_Name
(Name
(Call_Node
)));
2674 Parent_Subp
:= Empty
;
2676 -- Case of call to member of entry family, where Name is an indexed
2677 -- component, with the prefix being a selected component giving the
2678 -- task and entry family name, and the index being the entry index.
2680 elsif Nkind
(Name
(Call_Node
)) = N_Indexed_Component
then
2681 Subp
:= Entity
(Selector_Name
(Prefix
(Name
(Call_Node
))));
2682 Parent_Subp
:= Empty
;
2687 Subp
:= Entity
(Name
(Call_Node
));
2688 Parent_Subp
:= Alias
(Subp
);
2690 -- Replace call to Raise_Exception by call to Raise_Exception_Always
2691 -- if we can tell that the first parameter cannot possibly be null.
2692 -- This improves efficiency by avoiding a run-time test.
2694 -- We do not do this if Raise_Exception_Always does not exist, which
2695 -- can happen in configurable run time profiles which provide only a
2698 if Is_RTE
(Subp
, RE_Raise_Exception
)
2699 and then RTE_Available
(RE_Raise_Exception_Always
)
2702 FA
: constant Node_Id
:=
2703 Original_Node
(First_Actual
(Call_Node
));
2706 -- The case we catch is where the first argument is obtained
2707 -- using the Identity attribute (which must always be
2710 if Nkind
(FA
) = N_Attribute_Reference
2711 and then Attribute_Name
(FA
) = Name_Identity
2713 Subp
:= RTE
(RE_Raise_Exception_Always
);
2714 Set_Name
(Call_Node
, New_Occurrence_Of
(Subp
, Loc
));
2719 if Ekind
(Subp
) = E_Entry
then
2720 Parent_Subp
:= Empty
;
2724 -- Ada 2005 (AI-345): We have a procedure call as a triggering
2725 -- alternative in an asynchronous select or as an entry call in
2726 -- a conditional or timed select. Check whether the procedure call
2727 -- is a renaming of an entry and rewrite it as an entry call.
2729 if Ada_Version
>= Ada_2005
2730 and then Nkind
(Call_Node
) = N_Procedure_Call_Statement
2732 ((Nkind
(Parent
(Call_Node
)) = N_Triggering_Alternative
2733 and then Triggering_Statement
(Parent
(Call_Node
)) = Call_Node
)
2735 (Nkind
(Parent
(Call_Node
)) = N_Entry_Call_Alternative
2736 and then Entry_Call_Statement
(Parent
(Call_Node
)) = Call_Node
))
2740 Ren_Root
: Entity_Id
:= Subp
;
2743 -- This may be a chain of renamings, find the root
2745 if Present
(Alias
(Ren_Root
)) then
2746 Ren_Root
:= Alias
(Ren_Root
);
2749 if Present
(Original_Node
(Parent
(Parent
(Ren_Root
)))) then
2750 Ren_Decl
:= Original_Node
(Parent
(Parent
(Ren_Root
)));
2752 if Nkind
(Ren_Decl
) = N_Subprogram_Renaming_Declaration
then
2754 Make_Entry_Call_Statement
(Loc
,
2756 New_Copy_Tree
(Name
(Ren_Decl
)),
2757 Parameter_Associations
=>
2759 (Parameter_Associations
(Call_Node
))));
2767 if Modify_Tree_For_C
2768 and then Nkind
(Call_Node
) = N_Function_Call
2769 and then Is_Entity_Name
(Name
(Call_Node
))
2772 Func_Id
: constant Entity_Id
:=
2773 Ultimate_Alias
(Entity
(Name
(Call_Node
)));
2775 -- When generating C code, transform a function call that returns
2776 -- a constrained array type into procedure form.
2778 if Rewritten_For_C
(Func_Id
) then
2780 -- For internally generated calls ensure that they reference
2781 -- the entity of the spec of the called function (needed since
2782 -- the expander may generate calls using the entity of their
2783 -- body). See for example Expand_Boolean_Operator().
2785 if not (Comes_From_Source
(Call_Node
))
2786 and then Nkind
(Unit_Declaration_Node
(Func_Id
)) =
2789 Set_Entity
(Name
(Call_Node
),
2790 Corresponding_Function
2791 (Corresponding_Procedure
(Func_Id
)));
2794 Rewrite_Function_Call_For_C
(Call_Node
);
2797 -- Also introduce a temporary for functions that return a record
2798 -- called within another procedure or function call, since records
2799 -- are passed by pointer in the generated C code, and we cannot
2800 -- take a pointer from a subprogram call.
2802 elsif Nkind
(Parent
(Call_Node
)) in N_Subprogram_Call
2803 and then Is_Record_Type
(Etype
(Func_Id
))
2806 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
2811 -- Temp : ... := Func_Call (...);
2814 Make_Object_Declaration
(Loc
,
2815 Defining_Identifier
=> Temp_Id
,
2816 Object_Definition
=>
2817 New_Occurrence_Of
(Etype
(Func_Id
), Loc
),
2819 Make_Function_Call
(Loc
,
2821 New_Occurrence_Of
(Func_Id
, Loc
),
2822 Parameter_Associations
=>
2823 Parameter_Associations
(Call_Node
)));
2825 Insert_Action
(Parent
(Call_Node
), Decl
);
2826 Rewrite
(Call_Node
, New_Occurrence_Of
(Temp_Id
, Loc
));
2833 -- First step, compute extra actuals, corresponding to any Extra_Formals
2834 -- present. Note that we do not access Extra_Formals directly, instead
2835 -- we simply note the presence of the extra formals as we process the
2836 -- regular formals collecting corresponding actuals in Extra_Actuals.
2838 -- We also generate any required range checks for actuals for in formals
2839 -- as we go through the loop, since this is a convenient place to do it.
2840 -- (Though it seems that this would be better done in Expand_Actuals???)
2842 -- Special case: Thunks must not compute the extra actuals; they must
2843 -- just propagate to the target primitive their extra actuals.
2845 if Is_Thunk
(Current_Scope
)
2846 and then Thunk_Entity
(Current_Scope
) = Subp
2847 and then Present
(Extra_Formals
(Subp
))
2849 pragma Assert
(Present
(Extra_Formals
(Current_Scope
)));
2852 Target_Formal
: Entity_Id
;
2853 Thunk_Formal
: Entity_Id
;
2856 Target_Formal
:= Extra_Formals
(Subp
);
2857 Thunk_Formal
:= Extra_Formals
(Current_Scope
);
2858 while Present
(Target_Formal
) loop
2860 (Expr
=> New_Occurrence_Of
(Thunk_Formal
, Loc
),
2861 EF
=> Thunk_Formal
);
2863 Target_Formal
:= Extra_Formal
(Target_Formal
);
2864 Thunk_Formal
:= Extra_Formal
(Thunk_Formal
);
2867 while Is_Non_Empty_List
(Extra_Actuals
) loop
2868 Add_Actual_Parameter
(Remove_Head
(Extra_Actuals
));
2871 Expand_Actuals
(Call_Node
, Subp
, Post_Call
);
2872 pragma Assert
(Is_Empty_List
(Post_Call
));
2877 Formal
:= First_Formal
(Subp
);
2878 Actual
:= First_Actual
(Call_Node
);
2880 while Present
(Formal
) loop
2882 -- Generate range check if required
2884 if Do_Range_Check
(Actual
)
2885 and then Ekind
(Formal
) = E_In_Parameter
2887 Generate_Range_Check
2888 (Actual
, Etype
(Formal
), CE_Range_Check_Failed
);
2891 -- Prepare to examine current entry
2894 Prev_Orig
:= Original_Node
(Prev
);
2896 -- Ada 2005 (AI-251): Check if any formal is a class-wide interface
2897 -- to expand it in a further round.
2899 CW_Interface_Formals_Present
:=
2900 CW_Interface_Formals_Present
2902 (Is_Class_Wide_Type
(Etype
(Formal
))
2903 and then Is_Interface
(Etype
(Etype
(Formal
))))
2905 (Ekind
(Etype
(Formal
)) = E_Anonymous_Access_Type
2906 and then Is_Class_Wide_Type
(Directly_Designated_Type
2907 (Etype
(Etype
(Formal
))))
2908 and then Is_Interface
(Directly_Designated_Type
2909 (Etype
(Etype
(Formal
)))));
2911 -- Create possible extra actual for constrained case. Usually, the
2912 -- extra actual is of the form actual'constrained, but since this
2913 -- attribute is only available for unconstrained records, TRUE is
2914 -- expanded if the type of the formal happens to be constrained (for
2915 -- instance when this procedure is inherited from an unconstrained
2916 -- record to a constrained one) or if the actual has no discriminant
2917 -- (its type is constrained). An exception to this is the case of a
2918 -- private type without discriminants. In this case we pass FALSE
2919 -- because the object has underlying discriminants with defaults.
2921 if Present
(Extra_Constrained
(Formal
)) then
2922 if Ekind
(Etype
(Prev
)) in Private_Kind
2923 and then not Has_Discriminants
(Base_Type
(Etype
(Prev
)))
2926 (Expr
=> New_Occurrence_Of
(Standard_False
, Loc
),
2927 EF
=> Extra_Constrained
(Formal
));
2929 elsif Is_Constrained
(Etype
(Formal
))
2930 or else not Has_Discriminants
(Etype
(Prev
))
2933 (Expr
=> New_Occurrence_Of
(Standard_True
, Loc
),
2934 EF
=> Extra_Constrained
(Formal
));
2936 -- Do not produce extra actuals for Unchecked_Union parameters.
2937 -- Jump directly to the end of the loop.
2939 elsif Is_Unchecked_Union
(Base_Type
(Etype
(Actual
))) then
2940 goto Skip_Extra_Actual_Generation
;
2943 -- If the actual is a type conversion, then the constrained
2944 -- test applies to the actual, not the target type.
2950 -- Test for unchecked conversions as well, which can occur
2951 -- as out parameter actuals on calls to stream procedures.
2954 while Nkind_In
(Act_Prev
, N_Type_Conversion
,
2955 N_Unchecked_Type_Conversion
)
2957 Act_Prev
:= Expression
(Act_Prev
);
2960 -- If the expression is a conversion of a dereference, this
2961 -- is internally generated code that manipulates addresses,
2962 -- e.g. when building interface tables. No check should
2963 -- occur in this case, and the discriminated object is not
2966 if not Comes_From_Source
(Actual
)
2967 and then Nkind
(Actual
) = N_Unchecked_Type_Conversion
2968 and then Nkind
(Act_Prev
) = N_Explicit_Dereference
2971 (Expr
=> New_Occurrence_Of
(Standard_False
, Loc
),
2972 EF
=> Extra_Constrained
(Formal
));
2977 Make_Attribute_Reference
(Sloc
(Prev
),
2979 Duplicate_Subexpr_No_Checks
2980 (Act_Prev
, Name_Req
=> True),
2981 Attribute_Name
=> Name_Constrained
),
2982 EF
=> Extra_Constrained
(Formal
));
2988 -- Create possible extra actual for accessibility level
2990 if Present
(Extra_Accessibility
(Formal
)) then
2992 -- Ada 2005 (AI-252): If the actual was rewritten as an Access
2993 -- attribute, then the original actual may be an aliased object
2994 -- occurring as the prefix in a call using "Object.Operation"
2995 -- notation. In that case we must pass the level of the object,
2996 -- so Prev_Orig is reset to Prev and the attribute will be
2997 -- processed by the code for Access attributes further below.
2999 if Prev_Orig
/= Prev
3000 and then Nkind
(Prev
) = N_Attribute_Reference
3002 Get_Attribute_Id
(Attribute_Name
(Prev
)) = Attribute_Access
3003 and then Is_Aliased_View
(Prev_Orig
)
3007 -- If the actual is a formal of an enclosing subprogram it is
3008 -- the right entity, even if it is a rewriting. This happens
3009 -- when the call is within an inherited condition or predicate.
3011 elsif Is_Entity_Name
(Actual
)
3012 and then Is_Formal
(Entity
(Actual
))
3013 and then In_Open_Scopes
(Scope
(Entity
(Actual
)))
3017 elsif Nkind
(Prev_Orig
) = N_Type_Conversion
then
3018 Prev_Orig
:= Expression
(Prev_Orig
);
3021 -- Ada 2005 (AI-251): Thunks must propagate the extra actuals of
3022 -- accessibility levels.
3024 if Is_Thunk
(Current_Scope
) then
3026 Parm_Ent
: Entity_Id
;
3029 if Is_Controlling_Actual
(Actual
) then
3031 -- Find the corresponding actual of the thunk
3033 Parm_Ent
:= First_Entity
(Current_Scope
);
3034 for J
in 2 .. Param_Count
loop
3035 Next_Entity
(Parm_Ent
);
3038 -- Handle unchecked conversion of access types generated
3039 -- in thunks (cf. Expand_Interface_Thunk).
3041 elsif Is_Access_Type
(Etype
(Actual
))
3042 and then Nkind
(Actual
) = N_Unchecked_Type_Conversion
3044 Parm_Ent
:= Entity
(Expression
(Actual
));
3046 else pragma Assert
(Is_Entity_Name
(Actual
));
3047 Parm_Ent
:= Entity
(Actual
);
3052 New_Occurrence_Of
(Extra_Accessibility
(Parm_Ent
), Loc
),
3053 EF
=> Extra_Accessibility
(Formal
));
3056 elsif Is_Entity_Name
(Prev_Orig
) then
3058 -- When passing an access parameter, or a renaming of an access
3059 -- parameter, as the actual to another access parameter we need
3060 -- to pass along the actual's own access level parameter. This
3061 -- is done if we are within the scope of the formal access
3062 -- parameter (if this is an inlined body the extra formal is
3065 if (Is_Formal
(Entity
(Prev_Orig
))
3067 (Present
(Renamed_Object
(Entity
(Prev_Orig
)))
3069 Is_Entity_Name
(Renamed_Object
(Entity
(Prev_Orig
)))
3072 (Entity
(Renamed_Object
(Entity
(Prev_Orig
))))))
3073 and then Ekind
(Etype
(Prev_Orig
)) = E_Anonymous_Access_Type
3074 and then In_Open_Scopes
(Scope
(Entity
(Prev_Orig
)))
3077 Parm_Ent
: constant Entity_Id
:= Param_Entity
(Prev_Orig
);
3080 pragma Assert
(Present
(Parm_Ent
));
3082 if Present
(Extra_Accessibility
(Parm_Ent
)) then
3086 (Extra_Accessibility
(Parm_Ent
), Loc
),
3087 EF
=> Extra_Accessibility
(Formal
));
3089 -- If the actual access parameter does not have an
3090 -- associated extra formal providing its scope level,
3091 -- then treat the actual as having library-level
3097 Make_Integer_Literal
(Loc
,
3098 Intval
=> Scope_Depth
(Standard_Standard
)),
3099 EF
=> Extra_Accessibility
(Formal
));
3103 -- The actual is a normal access value, so just pass the level
3104 -- of the actual's access type.
3108 (Expr
=> Dynamic_Accessibility_Level
(Prev_Orig
),
3109 EF
=> Extra_Accessibility
(Formal
));
3112 -- If the actual is an access discriminant, then pass the level
3113 -- of the enclosing object (RM05-3.10.2(12.4/2)).
3115 elsif Nkind
(Prev_Orig
) = N_Selected_Component
3116 and then Ekind
(Entity
(Selector_Name
(Prev_Orig
))) =
3118 and then Ekind
(Etype
(Entity
(Selector_Name
(Prev_Orig
)))) =
3119 E_Anonymous_Access_Type
3123 Make_Integer_Literal
(Loc
,
3124 Intval
=> Object_Access_Level
(Prefix
(Prev_Orig
))),
3125 EF
=> Extra_Accessibility
(Formal
));
3130 case Nkind
(Prev_Orig
) is
3131 when N_Attribute_Reference
=>
3132 case Get_Attribute_Id
(Attribute_Name
(Prev_Orig
)) is
3134 -- For X'Access, pass on the level of the prefix X
3136 when Attribute_Access
=>
3138 -- Accessibility level of S'Access is that of A
3140 Prev_Orig
:= Prefix
(Prev_Orig
);
3142 -- If the expression is a view conversion, the
3143 -- accessibility level is that of the expression.
3145 if Nkind
(Original_Node
(Prev_Orig
)) =
3148 Nkind
(Expression
(Original_Node
(Prev_Orig
))) =
3149 N_Explicit_Dereference
3152 Expression
(Original_Node
(Prev_Orig
));
3155 -- If this is an Access attribute applied to the
3156 -- the current instance object passed to a type
3157 -- initialization procedure, then use the level
3158 -- of the type itself. This is not really correct,
3159 -- as there should be an extra level parameter
3160 -- passed in with _init formals (only in the case
3161 -- where the type is immutably limited), but we
3162 -- don't have an easy way currently to create such
3163 -- an extra formal (init procs aren't ever frozen).
3164 -- For now we just use the level of the type,
3165 -- which may be too shallow, but that works better
3166 -- than passing Object_Access_Level of the type,
3167 -- which can be one level too deep in some cases.
3170 -- A further case that requires special handling
3171 -- is the common idiom E.all'access. If E is a
3172 -- formal of the enclosing subprogram, the
3173 -- accessibility of the expression is that of E.
3175 if Is_Entity_Name
(Prev_Orig
) then
3176 Pref_Entity
:= Entity
(Prev_Orig
);
3178 elsif Nkind
(Prev_Orig
) = N_Explicit_Dereference
3179 and then Is_Entity_Name
(Prefix
(Prev_Orig
))
3181 Pref_Entity
:= Entity
(Prefix
((Prev_Orig
)));
3184 Pref_Entity
:= Empty
;
3187 if Is_Entity_Name
(Prev_Orig
)
3188 and then Is_Type
(Entity
(Prev_Orig
))
3192 Make_Integer_Literal
(Loc
,
3194 Type_Access_Level
(Pref_Entity
)),
3195 EF
=> Extra_Accessibility
(Formal
));
3197 elsif Nkind
(Prev_Orig
) = N_Explicit_Dereference
3198 and then Present
(Pref_Entity
)
3199 and then Is_Formal
(Pref_Entity
)
3201 (Extra_Accessibility
(Pref_Entity
))
3206 (Extra_Accessibility
(Pref_Entity
), Loc
),
3207 EF
=> Extra_Accessibility
(Formal
));
3212 Make_Integer_Literal
(Loc
,
3214 Object_Access_Level
(Prev_Orig
)),
3215 EF
=> Extra_Accessibility
(Formal
));
3218 -- Treat the unchecked attributes as library-level
3220 when Attribute_Unchecked_Access
3221 | Attribute_Unrestricted_Access
3225 Make_Integer_Literal
(Loc
,
3226 Intval
=> Scope_Depth
(Standard_Standard
)),
3227 EF
=> Extra_Accessibility
(Formal
));
3229 -- No other cases of attributes returning access
3230 -- values that can be passed to access parameters.
3233 raise Program_Error
;
3237 -- For allocators we pass the level of the execution of the
3238 -- called subprogram, which is one greater than the current
3244 Make_Integer_Literal
(Loc
,
3245 Intval
=> Scope_Depth
(Current_Scope
) + 1),
3246 EF
=> Extra_Accessibility
(Formal
));
3248 -- For most other cases we simply pass the level of the
3249 -- actual's access type. The type is retrieved from
3250 -- Prev rather than Prev_Orig, because in some cases
3251 -- Prev_Orig denotes an original expression that has
3252 -- not been analyzed.
3256 (Expr
=> Dynamic_Accessibility_Level
(Prev
),
3257 EF
=> Extra_Accessibility
(Formal
));
3262 -- Perform the check of 4.6(49) that prevents a null value from being
3263 -- passed as an actual to an access parameter. Note that the check
3264 -- is elided in the common cases of passing an access attribute or
3265 -- access parameter as an actual. Also, we currently don't enforce
3266 -- this check for expander-generated actuals and when -gnatdj is set.
3268 if Ada_Version
>= Ada_2005
then
3270 -- Ada 2005 (AI-231): Check null-excluding access types. Note that
3271 -- the intent of 6.4.1(13) is that null-exclusion checks should
3272 -- not be done for 'out' parameters, even though it refers only
3273 -- to constraint checks, and a null_exclusion is not a constraint.
3274 -- Note that AI05-0196-1 corrects this mistake in the RM.
3276 if Is_Access_Type
(Etype
(Formal
))
3277 and then Can_Never_Be_Null
(Etype
(Formal
))
3278 and then Ekind
(Formal
) /= E_Out_Parameter
3279 and then Nkind
(Prev
) /= N_Raise_Constraint_Error
3280 and then (Known_Null
(Prev
)
3281 or else not Can_Never_Be_Null
(Etype
(Prev
)))
3283 Install_Null_Excluding_Check
(Prev
);
3286 -- Ada_Version < Ada_2005
3289 if Ekind
(Etype
(Formal
)) /= E_Anonymous_Access_Type
3290 or else Access_Checks_Suppressed
(Subp
)
3294 elsif Debug_Flag_J
then
3297 elsif not Comes_From_Source
(Prev
) then
3300 elsif Is_Entity_Name
(Prev
)
3301 and then Ekind
(Etype
(Prev
)) = E_Anonymous_Access_Type
3305 elsif Nkind_In
(Prev
, N_Allocator
, N_Attribute_Reference
) then
3309 Install_Null_Excluding_Check
(Prev
);
3313 -- Perform appropriate validity checks on parameters that
3316 if Validity_Checks_On
then
3317 if (Ekind
(Formal
) = E_In_Parameter
3318 and then Validity_Check_In_Params
)
3320 (Ekind
(Formal
) = E_In_Out_Parameter
3321 and then Validity_Check_In_Out_Params
)
3323 -- If the actual is an indexed component of a packed type (or
3324 -- is an indexed or selected component whose prefix recursively
3325 -- meets this condition), it has not been expanded yet. It will
3326 -- be copied in the validity code that follows, and has to be
3327 -- expanded appropriately, so reanalyze it.
3329 -- What we do is just to unset analyzed bits on prefixes till
3330 -- we reach something that does not have a prefix.
3337 while Nkind_In
(Nod
, N_Indexed_Component
,
3338 N_Selected_Component
)
3340 Set_Analyzed
(Nod
, False);
3341 Nod
:= Prefix
(Nod
);
3345 Ensure_Valid
(Actual
);
3349 -- For IN OUT and OUT parameters, ensure that subscripts are valid
3350 -- since this is a left side reference. We only do this for calls
3351 -- from the source program since we assume that compiler generated
3352 -- calls explicitly generate any required checks. We also need it
3353 -- only if we are doing standard validity checks, since clearly it is
3354 -- not needed if validity checks are off, and in subscript validity
3355 -- checking mode, all indexed components are checked with a call
3356 -- directly from Expand_N_Indexed_Component.
3358 if Comes_From_Source
(Call_Node
)
3359 and then Ekind
(Formal
) /= E_In_Parameter
3360 and then Validity_Checks_On
3361 and then Validity_Check_Default
3362 and then not Validity_Check_Subscripts
3364 Check_Valid_Lvalue_Subscripts
(Actual
);
3367 -- Mark any scalar OUT parameter that is a simple variable as no
3368 -- longer known to be valid (unless the type is always valid). This
3369 -- reflects the fact that if an OUT parameter is never set in a
3370 -- procedure, then it can become invalid on the procedure return.
3372 if Ekind
(Formal
) = E_Out_Parameter
3373 and then Is_Entity_Name
(Actual
)
3374 and then Ekind
(Entity
(Actual
)) = E_Variable
3375 and then not Is_Known_Valid
(Etype
(Actual
))
3377 Set_Is_Known_Valid
(Entity
(Actual
), False);
3380 -- For an OUT or IN OUT parameter, if the actual is an entity, then
3381 -- clear current values, since they can be clobbered. We are probably
3382 -- doing this in more places than we need to, but better safe than
3383 -- sorry when it comes to retaining bad current values.
3385 if Ekind
(Formal
) /= E_In_Parameter
3386 and then Is_Entity_Name
(Actual
)
3387 and then Present
(Entity
(Actual
))
3390 Ent
: constant Entity_Id
:= Entity
(Actual
);
3394 -- For an OUT or IN OUT parameter that is an assignable entity,
3395 -- we do not want to clobber the Last_Assignment field, since
3396 -- if it is set, it was precisely because it is indeed an OUT
3397 -- or IN OUT parameter. We do reset the Is_Known_Valid flag
3398 -- since the subprogram could have returned in invalid value.
3400 if Ekind_In
(Formal
, E_Out_Parameter
, E_In_Out_Parameter
)
3401 and then Is_Assignable
(Ent
)
3403 Sav
:= Last_Assignment
(Ent
);
3404 Kill_Current_Values
(Ent
);
3405 Set_Last_Assignment
(Ent
, Sav
);
3406 Set_Is_Known_Valid
(Ent
, False);
3408 -- For all other cases, just kill the current values
3411 Kill_Current_Values
(Ent
);
3416 -- If the formal is class wide and the actual is an aggregate, force
3417 -- evaluation so that the back end who does not know about class-wide
3418 -- type, does not generate a temporary of the wrong size.
3420 if not Is_Class_Wide_Type
(Etype
(Formal
)) then
3423 elsif Nkind
(Actual
) = N_Aggregate
3424 or else (Nkind
(Actual
) = N_Qualified_Expression
3425 and then Nkind
(Expression
(Actual
)) = N_Aggregate
)
3427 Force_Evaluation
(Actual
);
3430 -- In a remote call, if the formal is of a class-wide type, check
3431 -- that the actual meets the requirements described in E.4(18).
3433 if Remote
and then Is_Class_Wide_Type
(Etype
(Formal
)) then
3434 Insert_Action
(Actual
,
3435 Make_Transportable_Check
(Loc
,
3436 Duplicate_Subexpr_Move_Checks
(Actual
)));
3439 -- Perform invariant checks for all intermediate types in a view
3440 -- conversion after successful return from a call that passes the
3441 -- view conversion as an IN OUT or OUT parameter (RM 7.3.2 (12/3,
3442 -- 13/3, 14/3)). Consider only source conversion in order to avoid
3443 -- generating spurious checks on complex expansion such as object
3444 -- initialization through an extension aggregate.
3446 if Comes_From_Source
(N
)
3447 and then Ekind
(Formal
) /= E_In_Parameter
3448 and then Nkind
(Actual
) = N_Type_Conversion
3450 Add_View_Conversion_Invariants
(Formal
, Actual
);
3453 -- Generating C the initialization of an allocator is performed by
3454 -- means of individual statements, and hence it must be done before
3457 if Modify_Tree_For_C
3458 and then Nkind
(Actual
) = N_Allocator
3459 and then Nkind
(Expression
(Actual
)) = N_Qualified_Expression
3461 Remove_Side_Effects
(Actual
);
3464 -- This label is required when skipping extra actual generation for
3465 -- Unchecked_Union parameters.
3467 <<Skip_Extra_Actual_Generation
>>
3469 Param_Count
:= Param_Count
+ 1;
3470 Next_Actual
(Actual
);
3471 Next_Formal
(Formal
);
3474 -- If we are calling an Ada 2012 function which needs to have the
3475 -- "accessibility level determined by the point of call" (AI05-0234)
3476 -- passed in to it, then pass it in.
3478 if Ekind_In
(Subp
, E_Function
, E_Operator
, E_Subprogram_Type
)
3480 Present
(Extra_Accessibility_Of_Result
(Ultimate_Alias
(Subp
)))
3483 Ancestor
: Node_Id
:= Parent
(Call_Node
);
3484 Level
: Node_Id
:= Empty
;
3485 Defer
: Boolean := False;
3488 -- Unimplemented: if Subp returns an anonymous access type, then
3490 -- a) if the call is the operand of an explict conversion, then
3491 -- the target type of the conversion (a named access type)
3492 -- determines the accessibility level pass in;
3494 -- b) if the call defines an access discriminant of an object
3495 -- (e.g., the discriminant of an object being created by an
3496 -- allocator, or the discriminant of a function result),
3497 -- then the accessibility level to pass in is that of the
3498 -- discriminated object being initialized).
3502 while Nkind
(Ancestor
) = N_Qualified_Expression
3504 Ancestor
:= Parent
(Ancestor
);
3507 case Nkind
(Ancestor
) is
3510 -- At this point, we'd like to assign
3512 -- Level := Dynamic_Accessibility_Level (Ancestor);
3514 -- but Etype of Ancestor may not have been set yet,
3515 -- so that doesn't work.
3517 -- Handle this later in Expand_Allocator_Expression.
3521 when N_Object_Declaration
3522 | N_Object_Renaming_Declaration
3525 Def_Id
: constant Entity_Id
:=
3526 Defining_Identifier
(Ancestor
);
3529 if Is_Return_Object
(Def_Id
) then
3530 if Present
(Extra_Accessibility_Of_Result
3531 (Return_Applies_To
(Scope
(Def_Id
))))
3533 -- Pass along value that was passed in if the
3534 -- routine we are returning from also has an
3535 -- Accessibility_Of_Result formal.
3539 (Extra_Accessibility_Of_Result
3540 (Return_Applies_To
(Scope
(Def_Id
))), Loc
);
3544 Make_Integer_Literal
(Loc
,
3545 Intval
=> Object_Access_Level
(Def_Id
));
3549 when N_Simple_Return_Statement
=>
3550 if Present
(Extra_Accessibility_Of_Result
3552 (Return_Statement_Entity
(Ancestor
))))
3554 -- Pass along value that was passed in if the returned
3555 -- routine also has an Accessibility_Of_Result formal.
3559 (Extra_Accessibility_Of_Result
3561 (Return_Statement_Entity
(Ancestor
))), Loc
);
3569 if not Present
(Level
) then
3571 -- The "innermost master that evaluates the function call".
3573 -- ??? - Should we use Integer'Last here instead in order
3574 -- to deal with (some of) the problems associated with
3575 -- calls to subps whose enclosing scope is unknown (e.g.,
3576 -- Anon_Access_To_Subp_Param.all)?
3579 Make_Integer_Literal
(Loc
,
3580 Intval
=> Scope_Depth
(Current_Scope
) + 1);
3586 Extra_Accessibility_Of_Result
(Ultimate_Alias
(Subp
)));
3591 -- If we are expanding the RHS of an assignment we need to check if tag
3592 -- propagation is needed. You might expect this processing to be in
3593 -- Analyze_Assignment but has to be done earlier (bottom-up) because the
3594 -- assignment might be transformed to a declaration for an unconstrained
3595 -- value if the expression is classwide.
3597 if Nkind
(Call_Node
) = N_Function_Call
3598 and then Is_Tag_Indeterminate
(Call_Node
)
3599 and then Is_Entity_Name
(Name
(Call_Node
))
3602 Ass
: Node_Id
:= Empty
;
3605 if Nkind
(Parent
(Call_Node
)) = N_Assignment_Statement
then
3606 Ass
:= Parent
(Call_Node
);
3608 elsif Nkind
(Parent
(Call_Node
)) = N_Qualified_Expression
3609 and then Nkind
(Parent
(Parent
(Call_Node
))) =
3610 N_Assignment_Statement
3612 Ass
:= Parent
(Parent
(Call_Node
));
3614 elsif Nkind
(Parent
(Call_Node
)) = N_Explicit_Dereference
3615 and then Nkind
(Parent
(Parent
(Call_Node
))) =
3616 N_Assignment_Statement
3618 Ass
:= Parent
(Parent
(Call_Node
));
3622 and then Is_Class_Wide_Type
(Etype
(Name
(Ass
)))
3624 if Is_Access_Type
(Etype
(Call_Node
)) then
3625 if Designated_Type
(Etype
(Call_Node
)) /=
3626 Root_Type
(Etype
(Name
(Ass
)))
3629 ("tag-indeterminate expression must have designated "
3630 & "type& (RM 5.2 (6))",
3631 Call_Node
, Root_Type
(Etype
(Name
(Ass
))));
3633 Propagate_Tag
(Name
(Ass
), Call_Node
);
3636 elsif Etype
(Call_Node
) /= Root_Type
(Etype
(Name
(Ass
))) then
3638 ("tag-indeterminate expression must have type & "
3640 Call_Node
, Root_Type
(Etype
(Name
(Ass
))));
3643 Propagate_Tag
(Name
(Ass
), Call_Node
);
3646 -- The call will be rewritten as a dispatching call, and
3647 -- expanded as such.
3654 -- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
3655 -- it to point to the correct secondary virtual table
3657 if Nkind
(Call_Node
) in N_Subprogram_Call
3658 and then CW_Interface_Formals_Present
3660 Expand_Interface_Actuals
(Call_Node
);
3663 -- Deals with Dispatch_Call if we still have a call, before expanding
3664 -- extra actuals since this will be done on the re-analysis of the
3665 -- dispatching call. Note that we do not try to shorten the actual list
3666 -- for a dispatching call, it would not make sense to do so. Expansion
3667 -- of dispatching calls is suppressed for VM targets, because the VM
3668 -- back-ends directly handle the generation of dispatching calls and
3669 -- would have to undo any expansion to an indirect call.
3671 if Nkind
(Call_Node
) in N_Subprogram_Call
3672 and then Present
(Controlling_Argument
(Call_Node
))
3675 Call_Typ
: constant Entity_Id
:= Etype
(Call_Node
);
3676 Typ
: constant Entity_Id
:= Find_Dispatching_Type
(Subp
);
3677 Eq_Prim_Op
: Entity_Id
:= Empty
;
3680 Prev_Call
: Node_Id
;
3683 if not Is_Limited_Type
(Typ
) then
3684 Eq_Prim_Op
:= Find_Prim_Op
(Typ
, Name_Op_Eq
);
3687 if Tagged_Type_Expansion
then
3688 Expand_Dispatching_Call
(Call_Node
);
3690 -- The following return is worrisome. Is it really OK to skip
3691 -- all remaining processing in this procedure ???
3698 Apply_Tag_Checks
(Call_Node
);
3700 -- If this is a dispatching "=", we must first compare the
3701 -- tags so we generate: x.tag = y.tag and then x = y
3703 if Subp
= Eq_Prim_Op
then
3705 -- Mark the node as analyzed to avoid reanalyzing this
3706 -- dispatching call (which would cause a never-ending loop)
3708 Prev_Call
:= Relocate_Node
(Call_Node
);
3709 Set_Analyzed
(Prev_Call
);
3711 Param
:= First_Actual
(Call_Node
);
3717 Make_Selected_Component
(Loc
,
3718 Prefix
=> New_Value
(Param
),
3721 (First_Tag_Component
(Typ
), Loc
)),
3724 Make_Selected_Component
(Loc
,
3726 Unchecked_Convert_To
(Typ
,
3727 New_Value
(Next_Actual
(Param
))),
3730 (First_Tag_Component
(Typ
), Loc
))),
3731 Right_Opnd
=> Prev_Call
);
3733 Rewrite
(Call_Node
, New_Call
);
3736 (Call_Node
, Call_Typ
, Suppress
=> All_Checks
);
3739 -- Expansion of a dispatching call results in an indirect call,
3740 -- which in turn causes current values to be killed (see
3741 -- Resolve_Call), so on VM targets we do the call here to
3742 -- ensure consistent warnings between VM and non-VM targets.
3744 Kill_Current_Values
;
3747 -- If this is a dispatching "=" then we must update the reference
3748 -- to the call node because we generated:
3749 -- x.tag = y.tag and then x = y
3751 if Subp
= Eq_Prim_Op
then
3752 Call_Node
:= Right_Opnd
(Call_Node
);
3757 -- Similarly, expand calls to RCI subprograms on which pragma
3758 -- All_Calls_Remote applies. The rewriting will be reanalyzed
3759 -- later. Do this only when the call comes from source since we
3760 -- do not want such a rewriting to occur in expanded code.
3762 if Is_All_Remote_Call
(Call_Node
) then
3763 Expand_All_Calls_Remote_Subprogram_Call
(Call_Node
);
3765 -- Similarly, do not add extra actuals for an entry call whose entity
3766 -- is a protected procedure, or for an internal protected subprogram
3767 -- call, because it will be rewritten as a protected subprogram call
3768 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
3770 elsif Is_Protected_Type
(Scope
(Subp
))
3771 and then (Ekind
(Subp
) = E_Procedure
3772 or else Ekind
(Subp
) = E_Function
)
3776 -- During that loop we gathered the extra actuals (the ones that
3777 -- correspond to Extra_Formals), so now they can be appended.
3780 while Is_Non_Empty_List
(Extra_Actuals
) loop
3781 Add_Actual_Parameter
(Remove_Head
(Extra_Actuals
));
3785 -- At this point we have all the actuals, so this is the point at which
3786 -- the various expansion activities for actuals is carried out.
3788 Expand_Actuals
(Call_Node
, Subp
, Post_Call
);
3790 -- Verify that the actuals do not share storage. This check must be done
3791 -- on the caller side rather that inside the subprogram to avoid issues
3792 -- of parameter passing.
3794 if Check_Aliasing_Of_Parameters
then
3795 Apply_Parameter_Aliasing_Checks
(Call_Node
, Subp
);
3798 -- If the subprogram is a renaming, or if it is inherited, replace it in
3799 -- the call with the name of the actual subprogram being called. If this
3800 -- is a dispatching call, the run-time decides what to call. The Alias
3801 -- attribute does not apply to entries.
3803 if Nkind
(Call_Node
) /= N_Entry_Call_Statement
3804 and then No
(Controlling_Argument
(Call_Node
))
3805 and then Present
(Parent_Subp
)
3806 and then not Is_Direct_Deep_Call
(Subp
)
3808 if Present
(Inherited_From_Formal
(Subp
)) then
3809 Parent_Subp
:= Inherited_From_Formal
(Subp
);
3811 Parent_Subp
:= Ultimate_Alias
(Parent_Subp
);
3814 -- The below setting of Entity is suspect, see F109-018 discussion???
3816 Set_Entity
(Name
(Call_Node
), Parent_Subp
);
3818 if Is_Abstract_Subprogram
(Parent_Subp
)
3819 and then not In_Instance
3822 ("cannot call abstract subprogram &!",
3823 Name
(Call_Node
), Parent_Subp
);
3826 -- Inspect all formals of derived subprogram Subp. Compare parameter
3827 -- types with the parent subprogram and check whether an actual may
3828 -- need a type conversion to the corresponding formal of the parent
3831 -- Not clear whether intrinsic subprograms need such conversions. ???
3833 if not Is_Intrinsic_Subprogram
(Parent_Subp
)
3834 or else Is_Generic_Instance
(Parent_Subp
)
3837 procedure Convert
(Act
: Node_Id
; Typ
: Entity_Id
);
3838 -- Rewrite node Act as a type conversion of Act to Typ. Analyze
3839 -- and resolve the newly generated construct.
3845 procedure Convert
(Act
: Node_Id
; Typ
: Entity_Id
) is
3847 Rewrite
(Act
, OK_Convert_To
(Typ
, Relocate_Node
(Act
)));
3854 Actual_Typ
: Entity_Id
;
3855 Formal_Typ
: Entity_Id
;
3856 Parent_Typ
: Entity_Id
;
3859 Actual
:= First_Actual
(Call_Node
);
3860 Formal
:= First_Formal
(Subp
);
3861 Parent_Formal
:= First_Formal
(Parent_Subp
);
3862 while Present
(Formal
) loop
3863 Actual_Typ
:= Etype
(Actual
);
3864 Formal_Typ
:= Etype
(Formal
);
3865 Parent_Typ
:= Etype
(Parent_Formal
);
3867 -- For an IN parameter of a scalar type, the parent formal
3868 -- type and derived formal type differ or the parent formal
3869 -- type and actual type do not match statically.
3871 if Is_Scalar_Type
(Formal_Typ
)
3872 and then Ekind
(Formal
) = E_In_Parameter
3873 and then Formal_Typ
/= Parent_Typ
3875 not Subtypes_Statically_Match
(Parent_Typ
, Actual_Typ
)
3876 and then not Raises_Constraint_Error
(Actual
)
3878 Convert
(Actual
, Parent_Typ
);
3879 Enable_Range_Check
(Actual
);
3881 -- If the actual has been marked as requiring a range
3882 -- check, then generate it here.
3884 if Do_Range_Check
(Actual
) then
3885 Generate_Range_Check
3886 (Actual
, Etype
(Formal
), CE_Range_Check_Failed
);
3889 -- For access types, the parent formal type and actual type
3892 elsif Is_Access_Type
(Formal_Typ
)
3893 and then Base_Type
(Parent_Typ
) /= Base_Type
(Actual_Typ
)
3895 if Ekind
(Formal
) /= E_In_Parameter
then
3896 Convert
(Actual
, Parent_Typ
);
3898 elsif Ekind
(Parent_Typ
) = E_Anonymous_Access_Type
3899 and then Designated_Type
(Parent_Typ
) /=
3900 Designated_Type
(Actual_Typ
)
3901 and then not Is_Controlling_Formal
(Formal
)
3903 -- This unchecked conversion is not necessary unless
3904 -- inlining is enabled, because in that case the type
3905 -- mismatch may become visible in the body about to be
3909 Unchecked_Convert_To
(Parent_Typ
,
3910 Relocate_Node
(Actual
)));
3912 Resolve
(Actual
, Parent_Typ
);
3915 -- If there is a change of representation, then generate a
3916 -- warning, and do the change of representation.
3918 elsif not Same_Representation
(Formal_Typ
, Parent_Typ
) then
3920 ("??change of representation required", Actual
);
3921 Convert
(Actual
, Parent_Typ
);
3923 -- For array and record types, the parent formal type and
3924 -- derived formal type have different sizes or pragma Pack
3927 elsif ((Is_Array_Type
(Formal_Typ
)
3928 and then Is_Array_Type
(Parent_Typ
))
3930 (Is_Record_Type
(Formal_Typ
)
3931 and then Is_Record_Type
(Parent_Typ
)))
3933 (Esize
(Formal_Typ
) /= Esize
(Parent_Typ
)
3934 or else Has_Pragma_Pack
(Formal_Typ
) /=
3935 Has_Pragma_Pack
(Parent_Typ
))
3937 Convert
(Actual
, Parent_Typ
);
3940 Next_Actual
(Actual
);
3941 Next_Formal
(Formal
);
3942 Next_Formal
(Parent_Formal
);
3948 Subp
:= Parent_Subp
;
3951 -- Deal with case where call is an explicit dereference
3953 if Nkind
(Name
(Call_Node
)) = N_Explicit_Dereference
then
3955 -- Handle case of access to protected subprogram type
3957 if Is_Access_Protected_Subprogram_Type
3958 (Base_Type
(Etype
(Prefix
(Name
(Call_Node
)))))
3960 -- If this is a call through an access to protected operation, the
3961 -- prefix has the form (object'address, operation'access). Rewrite
3962 -- as a for other protected calls: the object is the 1st parameter
3963 -- of the list of actuals.
3970 Ptr
: constant Node_Id
:= Prefix
(Name
(Call_Node
));
3972 T
: constant Entity_Id
:=
3973 Equivalent_Type
(Base_Type
(Etype
(Ptr
)));
3975 D_T
: constant Entity_Id
:=
3976 Designated_Type
(Base_Type
(Etype
(Ptr
)));
3980 Make_Selected_Component
(Loc
,
3981 Prefix
=> Unchecked_Convert_To
(T
, Ptr
),
3983 New_Occurrence_Of
(First_Entity
(T
), Loc
));
3986 Make_Selected_Component
(Loc
,
3987 Prefix
=> Unchecked_Convert_To
(T
, Ptr
),
3989 New_Occurrence_Of
(Next_Entity
(First_Entity
(T
)), Loc
));
3992 Make_Explicit_Dereference
(Loc
,
3995 if Present
(Parameter_Associations
(Call_Node
)) then
3996 Parm
:= Parameter_Associations
(Call_Node
);
4001 Prepend
(Obj
, Parm
);
4003 if Etype
(D_T
) = Standard_Void_Type
then
4005 Make_Procedure_Call_Statement
(Loc
,
4007 Parameter_Associations
=> Parm
);
4010 Make_Function_Call
(Loc
,
4012 Parameter_Associations
=> Parm
);
4015 Set_First_Named_Actual
(Call
, First_Named_Actual
(Call_Node
));
4016 Set_Etype
(Call
, Etype
(D_T
));
4018 -- We do not re-analyze the call to avoid infinite recursion.
4019 -- We analyze separately the prefix and the object, and set
4020 -- the checks on the prefix that would otherwise be emitted
4021 -- when resolving a call.
4023 Rewrite
(Call_Node
, Call
);
4025 Apply_Access_Check
(Nam
);
4032 -- If this is a call to an intrinsic subprogram, then perform the
4033 -- appropriate expansion to the corresponding tree node and we
4034 -- are all done (since after that the call is gone).
4036 -- In the case where the intrinsic is to be processed by the back end,
4037 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
4038 -- since the idea in this case is to pass the call unchanged. If the
4039 -- intrinsic is an inherited unchecked conversion, and the derived type
4040 -- is the target type of the conversion, we must retain it as the return
4041 -- type of the expression. Otherwise the expansion below, which uses the
4042 -- parent operation, will yield the wrong type.
4044 if Is_Intrinsic_Subprogram
(Subp
) then
4045 Expand_Intrinsic_Call
(Call_Node
, Subp
);
4047 if Nkind
(Call_Node
) = N_Unchecked_Type_Conversion
4048 and then Parent_Subp
/= Orig_Subp
4049 and then Etype
(Parent_Subp
) /= Etype
(Orig_Subp
)
4051 Set_Etype
(Call_Node
, Etype
(Orig_Subp
));
4057 if Ekind_In
(Subp
, E_Function
, E_Procedure
) then
4059 -- We perform a simple optimization on calls for To_Address by
4060 -- replacing them with an unchecked conversion. Not only is this
4061 -- efficient, but it also avoids order of elaboration problems when
4062 -- address clauses are inlined (address expression elaborated at the
4065 -- We perform this optimization regardless of whether we are in the
4066 -- main unit or in a unit in the context of the main unit, to ensure
4067 -- that the generated tree is the same in both cases, for CodePeer
4070 if Is_RTE
(Subp
, RE_To_Address
) then
4072 Unchecked_Convert_To
4073 (RTE
(RE_Address
), Relocate_Node
(First_Actual
(Call_Node
))));
4076 -- A call to a null procedure is replaced by a null statement, but we
4077 -- are not allowed to ignore possible side effects of the call, so we
4078 -- make sure that actuals are evaluated.
4079 -- We also suppress this optimization for GNATCoverage.
4081 elsif Is_Null_Procedure
(Subp
)
4082 and then not Opt
.Suppress_Control_Flow_Optimizations
4084 Actual
:= First_Actual
(Call_Node
);
4085 while Present
(Actual
) loop
4086 Remove_Side_Effects
(Actual
);
4087 Next_Actual
(Actual
);
4090 Rewrite
(Call_Node
, Make_Null_Statement
(Loc
));
4094 -- Handle inlining. No action needed if the subprogram is not inlined
4096 if not Is_Inlined
(Subp
) then
4099 -- Frontend inlining of expression functions (performed also when
4100 -- backend inlining is enabled).
4102 elsif Is_Inlinable_Expression_Function
(Subp
) then
4103 Rewrite
(N
, New_Copy
(Expression_Of_Expression_Function
(Subp
)));
4107 -- Handle frontend inlining
4109 elsif not Back_End_Inlining
then
4110 Inlined_Subprogram
: declare
4112 Must_Inline
: Boolean := False;
4113 Spec
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
4116 -- Verify that the body to inline has already been seen, and
4117 -- that if the body is in the current unit the inlining does
4118 -- not occur earlier. This avoids order-of-elaboration problems
4121 -- This should be documented in sinfo/einfo ???
4124 or else Nkind
(Spec
) /= N_Subprogram_Declaration
4125 or else No
(Body_To_Inline
(Spec
))
4127 Must_Inline
:= False;
4129 -- If this an inherited function that returns a private type,
4130 -- do not inline if the full view is an unconstrained array,
4131 -- because such calls cannot be inlined.
4133 elsif Present
(Orig_Subp
)
4134 and then Is_Array_Type
(Etype
(Orig_Subp
))
4135 and then not Is_Constrained
(Etype
(Orig_Subp
))
4137 Must_Inline
:= False;
4139 elsif In_Unfrozen_Instance
(Scope
(Subp
)) then
4140 Must_Inline
:= False;
4143 Bod
:= Body_To_Inline
(Spec
);
4145 if (In_Extended_Main_Code_Unit
(Call_Node
)
4146 or else In_Extended_Main_Code_Unit
(Parent
(Call_Node
))
4147 or else Has_Pragma_Inline_Always
(Subp
))
4148 and then (not In_Same_Extended_Unit
(Sloc
(Bod
), Loc
)
4150 Earlier_In_Extended_Unit
(Sloc
(Bod
), Loc
))
4152 Must_Inline
:= True;
4154 -- If we are compiling a package body that is not the main
4155 -- unit, it must be for inlining/instantiation purposes,
4156 -- in which case we inline the call to insure that the same
4157 -- temporaries are generated when compiling the body by
4158 -- itself. Otherwise link errors can occur.
4160 -- If the function being called is itself in the main unit,
4161 -- we cannot inline, because there is a risk of double
4162 -- elaboration and/or circularity: the inlining can make
4163 -- visible a private entity in the body of the main unit,
4164 -- that gigi will see before its sees its proper definition.
4166 elsif not (In_Extended_Main_Code_Unit
(Call_Node
))
4167 and then In_Package_Body
4169 Must_Inline
:= not In_Extended_Main_Source_Unit
(Subp
);
4171 -- Inline calls to _postconditions when generating C code
4173 elsif Modify_Tree_For_C
4174 and then In_Same_Extended_Unit
(Sloc
(Bod
), Loc
)
4175 and then Chars
(Name
(N
)) = Name_uPostconditions
4177 Must_Inline
:= True;
4182 Expand_Inlined_Call
(Call_Node
, Subp
, Orig_Subp
);
4185 -- Let the back end handle it
4187 Add_Inlined_Body
(Subp
, Call_Node
);
4189 if Front_End_Inlining
4190 and then Nkind
(Spec
) = N_Subprogram_Declaration
4191 and then (In_Extended_Main_Code_Unit
(Call_Node
))
4192 and then No
(Body_To_Inline
(Spec
))
4193 and then not Has_Completion
(Subp
)
4194 and then In_Same_Extended_Unit
(Sloc
(Spec
), Loc
)
4197 ("cannot inline& (body not seen yet)?",
4201 end Inlined_Subprogram
;
4203 -- Back end inlining: let the back end handle it
4205 elsif No
(Unit_Declaration_Node
(Subp
))
4206 or else Nkind
(Unit_Declaration_Node
(Subp
)) /=
4207 N_Subprogram_Declaration
4208 or else No
(Body_To_Inline
(Unit_Declaration_Node
(Subp
)))
4209 or else Nkind
(Body_To_Inline
(Unit_Declaration_Node
(Subp
))) in
4212 Add_Inlined_Body
(Subp
, Call_Node
);
4214 -- If the inlined call appears within an instantiation and some
4215 -- level of optimization is required, ensure that the enclosing
4216 -- instance body is available so that the back-end can actually
4217 -- perform the inlining.
4220 and then Comes_From_Source
(Subp
)
4221 and then Optimization_Level
> 0
4226 Inst_Node
: Node_Id
;
4229 Inst
:= Scope
(Subp
);
4231 -- Find enclosing instance
4233 while Present
(Inst
) and then Inst
/= Standard_Standard
loop
4234 exit when Is_Generic_Instance
(Inst
);
4235 Inst
:= Scope
(Inst
);
4239 and then Is_Generic_Instance
(Inst
)
4240 and then not Is_Inlined
(Inst
)
4242 Set_Is_Inlined
(Inst
);
4243 Decl
:= Unit_Declaration_Node
(Inst
);
4245 -- Do not add a pending instantiation if the body exits
4246 -- already, or if the instance is a compilation unit, or
4247 -- the instance node is missing.
4249 if Present
(Corresponding_Body
(Decl
))
4250 or else Nkind
(Parent
(Decl
)) = N_Compilation_Unit
4251 or else No
(Next
(Decl
))
4256 -- The instantiation node usually follows the package
4257 -- declaration for the instance. If the generic unit
4258 -- has aspect specifications, they are transformed
4259 -- into pragmas in the instance, and the instance node
4260 -- appears after them.
4262 Inst_Node
:= Next
(Decl
);
4264 while Nkind
(Inst_Node
) /= N_Package_Instantiation
loop
4265 Inst_Node
:= Next
(Inst_Node
);
4268 Add_Pending_Instantiation
(Inst_Node
, Decl
);
4274 -- Front end expansion of simple functions returning unconstrained
4275 -- types (see Check_And_Split_Unconstrained_Function). Note that the
4276 -- case of a simple renaming (Body_To_Inline in N_Entity above, see
4277 -- also Build_Renamed_Body) cannot be expanded here because this may
4278 -- give rise to order-of-elaboration issues for the types of the
4279 -- parameters of the subprogram, if any.
4282 Expand_Inlined_Call
(Call_Node
, Subp
, Orig_Subp
);
4286 -- Check for protected subprogram. This is either an intra-object call,
4287 -- or a protected function call. Protected procedure calls are rewritten
4288 -- as entry calls and handled accordingly.
4290 -- In Ada 2005, this may be an indirect call to an access parameter that
4291 -- is an access_to_subprogram. In that case the anonymous type has a
4292 -- scope that is a protected operation, but the call is a regular one.
4293 -- In either case do not expand call if subprogram is eliminated.
4295 Scop
:= Scope
(Subp
);
4297 if Nkind
(Call_Node
) /= N_Entry_Call_Statement
4298 and then Is_Protected_Type
(Scop
)
4299 and then Ekind
(Subp
) /= E_Subprogram_Type
4300 and then not Is_Eliminated
(Subp
)
4302 -- If the call is an internal one, it is rewritten as a call to the
4303 -- corresponding unprotected subprogram.
4305 Expand_Protected_Subprogram_Call
(Call_Node
, Subp
, Scop
);
4308 -- Functions returning controlled objects need special attention. If
4309 -- the return type is limited, then the context is initialization and
4310 -- different processing applies. If the call is to a protected function,
4311 -- the expansion above will call Expand_Call recursively. Otherwise the
4312 -- function call is transformed into a temporary which obtains the
4313 -- result from the secondary stack.
4315 if Needs_Finalization
(Etype
(Subp
)) then
4316 if not Is_Limited_View
(Etype
(Subp
))
4318 (No
(First_Formal
(Subp
))
4320 not Is_Concurrent_Record_Type
(Etype
(First_Formal
(Subp
))))
4322 Expand_Ctrl_Function_Call
(Call_Node
);
4324 -- Build-in-place function calls which appear in anonymous contexts
4325 -- need a transient scope to ensure the proper finalization of the
4326 -- intermediate result after its use.
4328 elsif Is_Build_In_Place_Function_Call
(Call_Node
)
4330 Nkind_In
(Parent
(Call_Node
), N_Attribute_Reference
,
4332 N_Indexed_Component
,
4333 N_Object_Renaming_Declaration
,
4334 N_Procedure_Call_Statement
,
4335 N_Selected_Component
,
4338 Establish_Transient_Scope
(Call_Node
, Sec_Stack
=> True);
4341 end Expand_Call_Helper
;
4343 -------------------------------
4344 -- Expand_Ctrl_Function_Call --
4345 -------------------------------
4347 procedure Expand_Ctrl_Function_Call
(N
: Node_Id
) is
4348 function Is_Element_Reference
(N
: Node_Id
) return Boolean;
4349 -- Determine whether node N denotes a reference to an Ada 2012 container
4352 --------------------------
4353 -- Is_Element_Reference --
4354 --------------------------
4356 function Is_Element_Reference
(N
: Node_Id
) return Boolean is
4357 Ref
: constant Node_Id
:= Original_Node
(N
);
4360 -- Analysis marks an element reference by setting the generalized
4361 -- indexing attribute of an indexed component before the component
4362 -- is rewritten into a function call.
4365 Nkind
(Ref
) = N_Indexed_Component
4366 and then Present
(Generalized_Indexing
(Ref
));
4367 end Is_Element_Reference
;
4369 -- Start of processing for Expand_Ctrl_Function_Call
4372 -- Optimization, if the returned value (which is on the sec-stack) is
4373 -- returned again, no need to copy/readjust/finalize, we can just pass
4374 -- the value thru (see Expand_N_Simple_Return_Statement), and thus no
4375 -- attachment is needed
4377 if Nkind
(Parent
(N
)) = N_Simple_Return_Statement
then
4381 -- Resolution is now finished, make sure we don't start analysis again
4382 -- because of the duplication.
4386 -- A function which returns a controlled object uses the secondary
4387 -- stack. Rewrite the call into a temporary which obtains the result of
4388 -- the function using 'reference.
4390 Remove_Side_Effects
(N
);
4392 -- The side effect removal of the function call produced a temporary.
4393 -- When the context is a case expression, if expression, or expression
4394 -- with actions, the lifetime of the temporary must be extended to match
4395 -- that of the context. Otherwise the function result will be finalized
4396 -- too early and affect the result of the expression. To prevent this
4397 -- unwanted effect, the temporary should not be considered for clean up
4398 -- actions by the general finalization machinery.
4400 -- Exception to this rule are references to Ada 2012 container elements.
4401 -- Such references must be finalized at the end of each iteration of the
4402 -- related quantified expression, otherwise the container will remain
4405 if Nkind
(N
) = N_Explicit_Dereference
4406 and then Within_Case_Or_If_Expression
(N
)
4407 and then not Is_Element_Reference
(N
)
4409 Set_Is_Ignored_Transient
(Entity
(Prefix
(N
)));
4411 end Expand_Ctrl_Function_Call
;
4413 ----------------------------------------
4414 -- Expand_N_Extended_Return_Statement --
4415 ----------------------------------------
4417 -- If there is a Handled_Statement_Sequence, we rewrite this:
4419 -- return Result : T := <expression> do
4420 -- <handled_seq_of_stms>
4426 -- Result : T := <expression>;
4428 -- <handled_seq_of_stms>
4432 -- Otherwise (no Handled_Statement_Sequence), we rewrite this:
4434 -- return Result : T := <expression>;
4438 -- return <expression>;
4440 -- unless it's build-in-place or there's no <expression>, in which case
4444 -- Result : T := <expression>;
4449 -- Note that this case could have been written by the user as an extended
4450 -- return statement, or could have been transformed to this from a simple
4451 -- return statement.
4453 -- That is, we need to have a reified return object if there are statements
4454 -- (which might refer to it) or if we're doing build-in-place (so we can
4455 -- set its address to the final resting place or if there is no expression
4456 -- (in which case default initial values might need to be set).
4458 procedure Expand_N_Extended_Return_Statement
(N
: Node_Id
) is
4459 Loc
: constant Source_Ptr
:= Sloc
(N
);
4461 function Build_Heap_Allocator
4462 (Temp_Id
: Entity_Id
;
4463 Temp_Typ
: Entity_Id
;
4464 Func_Id
: Entity_Id
;
4465 Ret_Typ
: Entity_Id
;
4466 Alloc_Expr
: Node_Id
) return Node_Id
;
4467 -- Create the statements necessary to allocate a return object on the
4468 -- caller's master. The master is available through implicit parameter
4469 -- BIPfinalizationmaster.
4471 -- if BIPfinalizationmaster /= null then
4473 -- type Ptr_Typ is access Ret_Typ;
4474 -- for Ptr_Typ'Storage_Pool use
4475 -- Base_Pool (BIPfinalizationmaster.all).all;
4479 -- procedure Allocate (...) is
4481 -- System.Storage_Pools.Subpools.Allocate_Any (...);
4484 -- Local := <Alloc_Expr>;
4485 -- Temp_Id := Temp_Typ (Local);
4489 -- Temp_Id is the temporary which is used to reference the internally
4490 -- created object in all allocation forms. Temp_Typ is the type of the
4491 -- temporary. Func_Id is the enclosing function. Ret_Typ is the return
4492 -- type of Func_Id. Alloc_Expr is the actual allocator.
4494 function Move_Activation_Chain
(Func_Id
: Entity_Id
) return Node_Id
;
4495 -- Construct a call to System.Tasking.Stages.Move_Activation_Chain
4497 -- From current activation chain
4498 -- To activation chain passed in by the caller
4499 -- New_Master master passed in by the caller
4501 -- Func_Id is the entity of the function where the extended return
4502 -- statement appears.
4504 --------------------------
4505 -- Build_Heap_Allocator --
4506 --------------------------
4508 function Build_Heap_Allocator
4509 (Temp_Id
: Entity_Id
;
4510 Temp_Typ
: Entity_Id
;
4511 Func_Id
: Entity_Id
;
4512 Ret_Typ
: Entity_Id
;
4513 Alloc_Expr
: Node_Id
) return Node_Id
4516 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
4518 -- Processing for build-in-place object allocation.
4520 if Needs_Finalization
(Ret_Typ
) then
4522 Decls
: constant List_Id
:= New_List
;
4523 Fin_Mas_Id
: constant Entity_Id
:=
4524 Build_In_Place_Formal
4525 (Func_Id
, BIP_Finalization_Master
);
4526 Stmts
: constant List_Id
:= New_List
;
4527 Desig_Typ
: Entity_Id
;
4528 Local_Id
: Entity_Id
;
4529 Pool_Id
: Entity_Id
;
4530 Ptr_Typ
: Entity_Id
;
4534 -- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
4536 Pool_Id
:= Make_Temporary
(Loc
, 'P');
4539 Make_Object_Renaming_Declaration
(Loc
,
4540 Defining_Identifier
=> Pool_Id
,
4542 New_Occurrence_Of
(RTE
(RE_Root_Storage_Pool
), Loc
),
4544 Make_Explicit_Dereference
(Loc
,
4546 Make_Function_Call
(Loc
,
4548 New_Occurrence_Of
(RTE
(RE_Base_Pool
), Loc
),
4549 Parameter_Associations
=> New_List
(
4550 Make_Explicit_Dereference
(Loc
,
4552 New_Occurrence_Of
(Fin_Mas_Id
, Loc
)))))));
4554 -- Create an access type which uses the storage pool of the
4555 -- caller's master. This additional type is necessary because
4556 -- the finalization master cannot be associated with the type
4557 -- of the temporary. Otherwise the secondary stack allocation
4560 Desig_Typ
:= Ret_Typ
;
4562 -- Ensure that the build-in-place machinery uses a fat pointer
4563 -- when allocating an unconstrained array on the heap. In this
4564 -- case the result object type is a constrained array type even
4565 -- though the function type is unconstrained.
4567 if Ekind
(Desig_Typ
) = E_Array_Subtype
then
4568 Desig_Typ
:= Base_Type
(Desig_Typ
);
4572 -- type Ptr_Typ is access Desig_Typ;
4574 Ptr_Typ
:= Make_Temporary
(Loc
, 'P');
4577 Make_Full_Type_Declaration
(Loc
,
4578 Defining_Identifier
=> Ptr_Typ
,
4580 Make_Access_To_Object_Definition
(Loc
,
4581 Subtype_Indication
=>
4582 New_Occurrence_Of
(Desig_Typ
, Loc
))));
4584 -- Perform minor decoration in order to set the master and the
4585 -- storage pool attributes.
4587 Set_Ekind
(Ptr_Typ
, E_Access_Type
);
4588 Set_Finalization_Master
(Ptr_Typ
, Fin_Mas_Id
);
4589 Set_Associated_Storage_Pool
(Ptr_Typ
, Pool_Id
);
4591 -- Create the temporary, generate:
4592 -- Local_Id : Ptr_Typ;
4594 Local_Id
:= Make_Temporary
(Loc
, 'T');
4597 Make_Object_Declaration
(Loc
,
4598 Defining_Identifier
=> Local_Id
,
4599 Object_Definition
=>
4600 New_Occurrence_Of
(Ptr_Typ
, Loc
)));
4602 -- Allocate the object, generate:
4603 -- Local_Id := <Alloc_Expr>;
4606 Make_Assignment_Statement
(Loc
,
4607 Name
=> New_Occurrence_Of
(Local_Id
, Loc
),
4608 Expression
=> Alloc_Expr
));
4611 -- Temp_Id := Temp_Typ (Local_Id);
4614 Make_Assignment_Statement
(Loc
,
4615 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4617 Unchecked_Convert_To
(Temp_Typ
,
4618 New_Occurrence_Of
(Local_Id
, Loc
))));
4620 -- Wrap the allocation in a block. This is further conditioned
4621 -- by checking the caller finalization master at runtime. A
4622 -- null value indicates a non-existent master, most likely due
4623 -- to a Finalize_Storage_Only allocation.
4626 -- if BIPfinalizationmaster /= null then
4635 Make_If_Statement
(Loc
,
4638 Left_Opnd
=> New_Occurrence_Of
(Fin_Mas_Id
, Loc
),
4639 Right_Opnd
=> Make_Null
(Loc
)),
4641 Then_Statements
=> New_List
(
4642 Make_Block_Statement
(Loc
,
4643 Declarations
=> Decls
,
4644 Handled_Statement_Sequence
=>
4645 Make_Handled_Sequence_Of_Statements
(Loc
,
4646 Statements
=> Stmts
))));
4649 -- For all other cases, generate:
4650 -- Temp_Id := <Alloc_Expr>;
4654 Make_Assignment_Statement
(Loc
,
4655 Name
=> New_Occurrence_Of
(Temp_Id
, Loc
),
4656 Expression
=> Alloc_Expr
);
4658 end Build_Heap_Allocator
;
4660 ---------------------------
4661 -- Move_Activation_Chain --
4662 ---------------------------
4664 function Move_Activation_Chain
(Func_Id
: Entity_Id
) return Node_Id
is
4667 Make_Procedure_Call_Statement
(Loc
,
4669 New_Occurrence_Of
(RTE
(RE_Move_Activation_Chain
), Loc
),
4671 Parameter_Associations
=> New_List
(
4675 Make_Attribute_Reference
(Loc
,
4676 Prefix
=> Make_Identifier
(Loc
, Name_uChain
),
4677 Attribute_Name
=> Name_Unrestricted_Access
),
4679 -- Destination chain
4682 (Build_In_Place_Formal
(Func_Id
, BIP_Activation_Chain
), Loc
),
4687 (Build_In_Place_Formal
(Func_Id
, BIP_Task_Master
), Loc
)));
4688 end Move_Activation_Chain
;
4692 Func_Id
: constant Entity_Id
:=
4693 Return_Applies_To
(Return_Statement_Entity
(N
));
4694 Is_BIP_Func
: constant Boolean :=
4695 Is_Build_In_Place_Function
(Func_Id
);
4696 Ret_Obj_Id
: constant Entity_Id
:=
4697 First_Entity
(Return_Statement_Entity
(N
));
4698 Ret_Obj_Decl
: constant Node_Id
:= Parent
(Ret_Obj_Id
);
4699 Ret_Typ
: constant Entity_Id
:= Etype
(Func_Id
);
4704 Return_Stmt
: Node_Id
;
4707 -- Start of processing for Expand_N_Extended_Return_Statement
4710 -- Given that functionality of interface thunks is simple (just displace
4711 -- the pointer to the object) they are always handled by means of
4712 -- simple return statements.
4714 pragma Assert
(not Is_Thunk
(Current_Scope
));
4716 if Nkind
(Ret_Obj_Decl
) = N_Object_Declaration
then
4717 Exp
:= Expression
(Ret_Obj_Decl
);
4722 HSS
:= Handled_Statement_Sequence
(N
);
4724 -- If the returned object needs finalization actions, the function must
4725 -- perform the appropriate cleanup should it fail to return. The state
4726 -- of the function itself is tracked through a flag which is coupled
4727 -- with the scope finalizer. There is one flag per each return object
4728 -- in case of multiple returns.
4730 if Is_BIP_Func
and then Needs_Finalization
(Etype
(Ret_Obj_Id
)) then
4732 Flag_Decl
: Node_Id
;
4733 Flag_Id
: Entity_Id
;
4737 -- Recover the function body
4739 Func_Bod
:= Unit_Declaration_Node
(Func_Id
);
4741 if Nkind
(Func_Bod
) = N_Subprogram_Declaration
then
4742 Func_Bod
:= Parent
(Parent
(Corresponding_Body
(Func_Bod
)));
4745 -- Create a flag to track the function state
4747 Flag_Id
:= Make_Temporary
(Loc
, 'F');
4748 Set_Status_Flag_Or_Transient_Decl
(Ret_Obj_Id
, Flag_Id
);
4750 -- Insert the flag at the beginning of the function declarations,
4752 -- Fnn : Boolean := False;
4755 Make_Object_Declaration
(Loc
,
4756 Defining_Identifier
=> Flag_Id
,
4757 Object_Definition
=>
4758 New_Occurrence_Of
(Standard_Boolean
, Loc
),
4760 New_Occurrence_Of
(Standard_False
, Loc
));
4762 Prepend_To
(Declarations
(Func_Bod
), Flag_Decl
);
4763 Analyze
(Flag_Decl
);
4767 -- Build a simple_return_statement that returns the return object when
4768 -- there is a statement sequence, or no expression, or the result will
4769 -- be built in place. Note however that we currently do this for all
4770 -- composite cases, even though nonlimited composite results are not yet
4771 -- built in place (though we plan to do so eventually).
4774 or else Is_Composite_Type
(Ret_Typ
)
4780 -- If the extended return has a handled statement sequence, then wrap
4781 -- it in a block and use the block as the first statement.
4785 Make_Block_Statement
(Loc
,
4786 Declarations
=> New_List
,
4787 Handled_Statement_Sequence
=> HSS
));
4790 -- If the result type contains tasks, we call Move_Activation_Chain.
4791 -- Later, the cleanup code will call Complete_Master, which will
4792 -- terminate any unactivated tasks belonging to the return statement
4793 -- master. But Move_Activation_Chain updates their master to be that
4794 -- of the caller, so they will not be terminated unless the return
4795 -- statement completes unsuccessfully due to exception, abort, goto,
4796 -- or exit. As a formality, we test whether the function requires the
4797 -- result to be built in place, though that's necessarily true for
4798 -- the case of result types with task parts.
4800 if Is_BIP_Func
and then Has_Task
(Ret_Typ
) then
4802 -- The return expression is an aggregate for a complex type which
4803 -- contains tasks. This particular case is left unexpanded since
4804 -- the regular expansion would insert all temporaries and
4805 -- initialization code in the wrong block.
4807 if Nkind
(Exp
) = N_Aggregate
then
4808 Expand_N_Aggregate
(Exp
);
4811 -- Do not move the activation chain if the return object does not
4814 if Has_Task
(Etype
(Ret_Obj_Id
)) then
4815 Append_To
(Stmts
, Move_Activation_Chain
(Func_Id
));
4819 -- Update the state of the function right before the object is
4822 if Is_BIP_Func
and then Needs_Finalization
(Etype
(Ret_Obj_Id
)) then
4824 Flag_Id
: constant Entity_Id
:=
4825 Status_Flag_Or_Transient_Decl
(Ret_Obj_Id
);
4832 Make_Assignment_Statement
(Loc
,
4833 Name
=> New_Occurrence_Of
(Flag_Id
, Loc
),
4834 Expression
=> New_Occurrence_Of
(Standard_True
, Loc
)));
4838 -- Build a simple_return_statement that returns the return object
4841 Make_Simple_Return_Statement
(Loc
,
4842 Expression
=> New_Occurrence_Of
(Ret_Obj_Id
, Loc
));
4843 Append_To
(Stmts
, Return_Stmt
);
4845 HSS
:= Make_Handled_Sequence_Of_Statements
(Loc
, Stmts
);
4848 -- Case where we build a return statement block
4850 if Present
(HSS
) then
4852 Make_Block_Statement
(Loc
,
4853 Declarations
=> Return_Object_Declarations
(N
),
4854 Handled_Statement_Sequence
=> HSS
);
4856 -- We set the entity of the new block statement to be that of the
4857 -- return statement. This is necessary so that various fields, such
4858 -- as Finalization_Chain_Entity carry over from the return statement
4859 -- to the block. Note that this block is unusual, in that its entity
4860 -- is an E_Return_Statement rather than an E_Block.
4863 (Result
, New_Occurrence_Of
(Return_Statement_Entity
(N
), Loc
));
4865 -- If the object decl was already rewritten as a renaming, then we
4866 -- don't want to do the object allocation and transformation of
4867 -- the return object declaration to a renaming. This case occurs
4868 -- when the return object is initialized by a call to another
4869 -- build-in-place function, and that function is responsible for
4870 -- the allocation of the return object.
4873 and then Nkind
(Ret_Obj_Decl
) = N_Object_Renaming_Declaration
4876 (Nkind
(Original_Node
(Ret_Obj_Decl
)) = N_Object_Declaration
4879 -- It is a regular BIP object declaration
4881 (Is_Build_In_Place_Function_Call
4882 (Expression
(Original_Node
(Ret_Obj_Decl
)))
4884 -- It is a BIP object declaration that displaces the pointer
4885 -- to the object to reference a convered interface type.
4888 Present
(Unqual_BIP_Iface_Function_Call
4889 (Expression
(Original_Node
(Ret_Obj_Decl
))))));
4891 -- Return the build-in-place result by reference
4893 Set_By_Ref
(Return_Stmt
);
4895 elsif Is_BIP_Func
then
4897 -- Locate the implicit access parameter associated with the
4898 -- caller-supplied return object and convert the return
4899 -- statement's return object declaration to a renaming of a
4900 -- dereference of the access parameter. If the return object's
4901 -- declaration includes an expression that has not already been
4902 -- expanded as separate assignments, then add an assignment
4903 -- statement to ensure the return object gets initialized.
4906 -- Result : T [:= <expression>];
4913 -- Result : T renames FuncRA.all;
4914 -- [Result := <expression;]
4919 Ret_Obj_Expr
: constant Node_Id
:= Expression
(Ret_Obj_Decl
);
4920 Ret_Obj_Typ
: constant Entity_Id
:= Etype
(Ret_Obj_Id
);
4922 Init_Assignment
: Node_Id
:= Empty
;
4923 Obj_Acc_Formal
: Entity_Id
;
4924 Obj_Acc_Deref
: Node_Id
;
4925 Obj_Alloc_Formal
: Entity_Id
;
4928 -- Build-in-place results must be returned by reference
4930 Set_By_Ref
(Return_Stmt
);
4932 -- Retrieve the implicit access parameter passed by the caller
4935 Build_In_Place_Formal
(Func_Id
, BIP_Object_Access
);
4937 -- If the return object's declaration includes an expression
4938 -- and the declaration isn't marked as No_Initialization, then
4939 -- we need to generate an assignment to the object and insert
4940 -- it after the declaration before rewriting it as a renaming
4941 -- (otherwise we'll lose the initialization). The case where
4942 -- the result type is an interface (or class-wide interface)
4943 -- is also excluded because the context of the function call
4944 -- must be unconstrained, so the initialization will always
4945 -- be done as part of an allocator evaluation (storage pool
4946 -- or secondary stack), never to a constrained target object
4947 -- passed in by the caller. Besides the assignment being
4948 -- unneeded in this case, it avoids problems with trying to
4949 -- generate a dispatching assignment when the return expression
4950 -- is a nonlimited descendant of a limited interface (the
4951 -- interface has no assignment operation).
4953 if Present
(Ret_Obj_Expr
)
4954 and then not No_Initialization
(Ret_Obj_Decl
)
4955 and then not Is_Interface
(Ret_Obj_Typ
)
4958 Make_Assignment_Statement
(Loc
,
4959 Name
=> New_Occurrence_Of
(Ret_Obj_Id
, Loc
),
4960 Expression
=> New_Copy_Tree
(Ret_Obj_Expr
));
4962 Set_Etype
(Name
(Init_Assignment
), Etype
(Ret_Obj_Id
));
4963 Set_Assignment_OK
(Name
(Init_Assignment
));
4964 Set_No_Ctrl_Actions
(Init_Assignment
);
4966 Set_Parent
(Name
(Init_Assignment
), Init_Assignment
);
4967 Set_Parent
(Expression
(Init_Assignment
), Init_Assignment
);
4969 Set_Expression
(Ret_Obj_Decl
, Empty
);
4971 if Is_Class_Wide_Type
(Etype
(Ret_Obj_Id
))
4972 and then not Is_Class_Wide_Type
4973 (Etype
(Expression
(Init_Assignment
)))
4975 Rewrite
(Expression
(Init_Assignment
),
4976 Make_Type_Conversion
(Loc
,
4978 New_Occurrence_Of
(Etype
(Ret_Obj_Id
), Loc
),
4980 Relocate_Node
(Expression
(Init_Assignment
))));
4983 -- In the case of functions where the calling context can
4984 -- determine the form of allocation needed, initialization
4985 -- is done with each part of the if statement that handles
4986 -- the different forms of allocation (this is true for
4987 -- unconstrained and tagged result subtypes).
4989 if Is_Constrained
(Ret_Typ
)
4990 and then not Is_Tagged_Type
(Underlying_Type
(Ret_Typ
))
4992 Insert_After
(Ret_Obj_Decl
, Init_Assignment
);
4996 -- When the function's subtype is unconstrained, a run-time
4997 -- test is needed to determine the form of allocation to use
4998 -- for the return object. The function has an implicit formal
4999 -- parameter indicating this. If the BIP_Alloc_Form formal has
5000 -- the value one, then the caller has passed access to an
5001 -- existing object for use as the return object. If the value
5002 -- is two, then the return object must be allocated on the
5003 -- secondary stack. Otherwise, the object must be allocated in
5004 -- a storage pool (currently only supported for the global
5005 -- heap, user-defined storage pools TBD ???). We generate an
5006 -- if statement to test the implicit allocation formal and
5007 -- initialize a local access value appropriately, creating
5008 -- allocators in the secondary stack and global heap cases.
5009 -- The special formal also exists and must be tested when the
5010 -- function has a tagged result, even when the result subtype
5011 -- is constrained, because in general such functions can be
5012 -- called in dispatching contexts and must be handled similarly
5013 -- to functions with a class-wide result.
5015 if not Is_Constrained
(Ret_Typ
)
5016 or else Is_Tagged_Type
(Underlying_Type
(Ret_Typ
))
5019 Build_In_Place_Formal
(Func_Id
, BIP_Alloc_Form
);
5022 Pool_Id
: constant Entity_Id
:=
5023 Make_Temporary
(Loc
, 'P');
5024 Alloc_Obj_Id
: Entity_Id
;
5025 Alloc_Obj_Decl
: Node_Id
;
5026 Alloc_If_Stmt
: Node_Id
;
5027 Heap_Allocator
: Node_Id
;
5028 Pool_Decl
: Node_Id
;
5029 Pool_Allocator
: Node_Id
;
5030 Ptr_Type_Decl
: Node_Id
;
5031 Ref_Type
: Entity_Id
;
5032 SS_Allocator
: Node_Id
;
5035 -- Reuse the itype created for the function's implicit
5036 -- access formal. This avoids the need to create a new
5037 -- access type here, plus it allows assigning the access
5038 -- formal directly without applying a conversion.
5040 -- Ref_Type := Etype (Object_Access);
5042 -- Create an access type designating the function's
5045 Ref_Type
:= Make_Temporary
(Loc
, 'A');
5048 Make_Full_Type_Declaration
(Loc
,
5049 Defining_Identifier
=> Ref_Type
,
5051 Make_Access_To_Object_Definition
(Loc
,
5052 All_Present
=> True,
5053 Subtype_Indication
=>
5054 New_Occurrence_Of
(Ret_Obj_Typ
, Loc
)));
5056 Insert_Before
(Ret_Obj_Decl
, Ptr_Type_Decl
);
5058 -- Create an access object that will be initialized to an
5059 -- access value denoting the return object, either coming
5060 -- from an implicit access value passed in by the caller
5061 -- or from the result of an allocator.
5063 Alloc_Obj_Id
:= Make_Temporary
(Loc
, 'R');
5064 Set_Etype
(Alloc_Obj_Id
, Ref_Type
);
5067 Make_Object_Declaration
(Loc
,
5068 Defining_Identifier
=> Alloc_Obj_Id
,
5069 Object_Definition
=>
5070 New_Occurrence_Of
(Ref_Type
, Loc
));
5072 Insert_Before
(Ret_Obj_Decl
, Alloc_Obj_Decl
);
5074 -- Create allocators for both the secondary stack and
5075 -- global heap. If there's an initialization expression,
5076 -- then create these as initialized allocators.
5078 if Present
(Ret_Obj_Expr
)
5079 and then not No_Initialization
(Ret_Obj_Decl
)
5081 -- Always use the type of the expression for the
5082 -- qualified expression, rather than the result type.
5083 -- In general we cannot always use the result type
5084 -- for the allocator, because the expression might be
5085 -- of a specific type, such as in the case of an
5086 -- aggregate or even a nonlimited object when the
5087 -- result type is a limited class-wide interface type.
5090 Make_Allocator
(Loc
,
5092 Make_Qualified_Expression
(Loc
,
5095 (Etype
(Ret_Obj_Expr
), Loc
),
5096 Expression
=> New_Copy_Tree
(Ret_Obj_Expr
)));
5099 -- If the function returns a class-wide type we cannot
5100 -- use the return type for the allocator. Instead we
5101 -- use the type of the expression, which must be an
5102 -- aggregate of a definite type.
5104 if Is_Class_Wide_Type
(Ret_Obj_Typ
) then
5106 Make_Allocator
(Loc
,
5109 (Etype
(Ret_Obj_Expr
), Loc
));
5112 Make_Allocator
(Loc
,
5114 New_Occurrence_Of
(Ret_Obj_Typ
, Loc
));
5117 -- If the object requires default initialization then
5118 -- that will happen later following the elaboration of
5119 -- the object renaming. If we don't turn it off here
5120 -- then the object will be default initialized twice.
5122 Set_No_Initialization
(Heap_Allocator
);
5125 -- The Pool_Allocator is just like the Heap_Allocator,
5126 -- except we set Storage_Pool and Procedure_To_Call so
5127 -- it will use the user-defined storage pool.
5129 Pool_Allocator
:= New_Copy_Tree
(Heap_Allocator
);
5131 -- Do not generate the renaming of the build-in-place
5132 -- pool parameter on ZFP because the parameter is not
5133 -- created in the first place.
5135 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
5137 Make_Object_Renaming_Declaration
(Loc
,
5138 Defining_Identifier
=> Pool_Id
,
5141 (RTE
(RE_Root_Storage_Pool
), Loc
),
5143 Make_Explicit_Dereference
(Loc
,
5145 (Build_In_Place_Formal
5146 (Func_Id
, BIP_Storage_Pool
), Loc
)));
5147 Set_Storage_Pool
(Pool_Allocator
, Pool_Id
);
5148 Set_Procedure_To_Call
5149 (Pool_Allocator
, RTE
(RE_Allocate_Any
));
5151 Pool_Decl
:= Make_Null_Statement
(Loc
);
5154 -- If the No_Allocators restriction is active, then only
5155 -- an allocator for secondary stack allocation is needed.
5156 -- It's OK for such allocators to have Comes_From_Source
5157 -- set to False, because gigi knows not to flag them as
5158 -- being a violation of No_Implicit_Heap_Allocations.
5160 if Restriction_Active
(No_Allocators
) then
5161 SS_Allocator
:= Heap_Allocator
;
5162 Heap_Allocator
:= Make_Null
(Loc
);
5163 Pool_Allocator
:= Make_Null
(Loc
);
5165 -- Otherwise the heap and pool allocators may be needed,
5166 -- so we make another allocator for secondary stack
5170 SS_Allocator
:= New_Copy_Tree
(Heap_Allocator
);
5172 -- The heap and pool allocators are marked as
5173 -- Comes_From_Source since they correspond to an
5174 -- explicit user-written allocator (that is, it will
5175 -- only be executed on behalf of callers that call the
5176 -- function as initialization for such an allocator).
5177 -- Prevents errors when No_Implicit_Heap_Allocations
5180 Set_Comes_From_Source
(Heap_Allocator
, True);
5181 Set_Comes_From_Source
(Pool_Allocator
, True);
5184 -- The allocator is returned on the secondary stack.
5186 Set_Storage_Pool
(SS_Allocator
, RTE
(RE_SS_Pool
));
5187 Set_Procedure_To_Call
5188 (SS_Allocator
, RTE
(RE_SS_Allocate
));
5190 -- The allocator is returned on the secondary stack,
5191 -- so indicate that the function return, as well as
5192 -- all blocks that encloses the allocator, must not
5193 -- release it. The flags must be set now because
5194 -- the decision to use the secondary stack is done
5195 -- very late in the course of expanding the return
5196 -- statement, past the point where these flags are
5199 Set_Uses_Sec_Stack
(Func_Id
);
5200 Set_Uses_Sec_Stack
(Return_Statement_Entity
(N
));
5201 Set_Sec_Stack_Needed_For_Return
5202 (Return_Statement_Entity
(N
));
5203 Set_Enclosing_Sec_Stack_Return
(N
);
5205 -- Create an if statement to test the BIP_Alloc_Form
5206 -- formal and initialize the access object to either the
5207 -- BIP_Object_Access formal (BIP_Alloc_Form =
5208 -- Caller_Allocation), the result of allocating the
5209 -- object in the secondary stack (BIP_Alloc_Form =
5210 -- Secondary_Stack), or else an allocator to create the
5211 -- return object in the heap or user-defined pool
5212 -- (BIP_Alloc_Form = Global_Heap or User_Storage_Pool).
5214 -- ??? An unchecked type conversion must be made in the
5215 -- case of assigning the access object formal to the
5216 -- local access object, because a normal conversion would
5217 -- be illegal in some cases (such as converting access-
5218 -- to-unconstrained to access-to-constrained), but the
5219 -- the unchecked conversion will presumably fail to work
5220 -- right in just such cases. It's not clear at all how to
5224 Make_If_Statement
(Loc
,
5228 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5230 Make_Integer_Literal
(Loc
,
5231 UI_From_Int
(BIP_Allocation_Form
'Pos
5232 (Caller_Allocation
)))),
5234 Then_Statements
=> New_List
(
5235 Make_Assignment_Statement
(Loc
,
5237 New_Occurrence_Of
(Alloc_Obj_Id
, Loc
),
5239 Make_Unchecked_Type_Conversion
(Loc
,
5241 New_Occurrence_Of
(Ref_Type
, Loc
),
5243 New_Occurrence_Of
(Obj_Acc_Formal
, Loc
)))),
5245 Elsif_Parts
=> New_List
(
5246 Make_Elsif_Part
(Loc
,
5250 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5252 Make_Integer_Literal
(Loc
,
5253 UI_From_Int
(BIP_Allocation_Form
'Pos
5254 (Secondary_Stack
)))),
5256 Then_Statements
=> New_List
(
5257 Make_Assignment_Statement
(Loc
,
5259 New_Occurrence_Of
(Alloc_Obj_Id
, Loc
),
5260 Expression
=> SS_Allocator
))),
5262 Make_Elsif_Part
(Loc
,
5266 New_Occurrence_Of
(Obj_Alloc_Formal
, Loc
),
5268 Make_Integer_Literal
(Loc
,
5269 UI_From_Int
(BIP_Allocation_Form
'Pos
5272 Then_Statements
=> New_List
(
5273 Build_Heap_Allocator
5274 (Temp_Id
=> Alloc_Obj_Id
,
5275 Temp_Typ
=> Ref_Type
,
5277 Ret_Typ
=> Ret_Obj_Typ
,
5278 Alloc_Expr
=> Heap_Allocator
)))),
5280 Else_Statements
=> New_List
(
5282 Build_Heap_Allocator
5283 (Temp_Id
=> Alloc_Obj_Id
,
5284 Temp_Typ
=> Ref_Type
,
5286 Ret_Typ
=> Ret_Obj_Typ
,
5287 Alloc_Expr
=> Pool_Allocator
)));
5289 -- If a separate initialization assignment was created
5290 -- earlier, append that following the assignment of the
5291 -- implicit access formal to the access object, to ensure
5292 -- that the return object is initialized in that case. In
5293 -- this situation, the target of the assignment must be
5294 -- rewritten to denote a dereference of the access to the
5295 -- return object passed in by the caller.
5297 if Present
(Init_Assignment
) then
5298 Rewrite
(Name
(Init_Assignment
),
5299 Make_Explicit_Dereference
(Loc
,
5300 Prefix
=> New_Occurrence_Of
(Alloc_Obj_Id
, Loc
)));
5302 Set_Etype
(Name
(Init_Assignment
), Etype
(Ret_Obj_Id
));
5305 (Then_Statements
(Alloc_If_Stmt
), Init_Assignment
);
5308 Insert_Before
(Ret_Obj_Decl
, Alloc_If_Stmt
);
5310 -- Remember the local access object for use in the
5311 -- dereference of the renaming created below.
5313 Obj_Acc_Formal
:= Alloc_Obj_Id
;
5317 -- Replace the return object declaration with a renaming of a
5318 -- dereference of the access value designating the return
5322 Make_Explicit_Dereference
(Loc
,
5323 Prefix
=> New_Occurrence_Of
(Obj_Acc_Formal
, Loc
));
5325 Rewrite
(Ret_Obj_Decl
,
5326 Make_Object_Renaming_Declaration
(Loc
,
5327 Defining_Identifier
=> Ret_Obj_Id
,
5328 Access_Definition
=> Empty
,
5329 Subtype_Mark
=> New_Occurrence_Of
(Ret_Obj_Typ
, Loc
),
5330 Name
=> Obj_Acc_Deref
));
5332 Set_Renamed_Object
(Ret_Obj_Id
, Obj_Acc_Deref
);
5336 -- Case where we do not build a block
5339 -- We're about to drop Return_Object_Declarations on the floor, so
5340 -- we need to insert it, in case it got expanded into useful code.
5341 -- Remove side effects from expression, which may be duplicated in
5342 -- subsequent checks (see Expand_Simple_Function_Return).
5344 Insert_List_Before
(N
, Return_Object_Declarations
(N
));
5345 Remove_Side_Effects
(Exp
);
5347 -- Build simple_return_statement that returns the expression directly
5349 Return_Stmt
:= Make_Simple_Return_Statement
(Loc
, Expression
=> Exp
);
5350 Result
:= Return_Stmt
;
5353 -- Set the flag to prevent infinite recursion
5355 Set_Comes_From_Extended_Return_Statement
(Return_Stmt
);
5357 Rewrite
(N
, Result
);
5359 end Expand_N_Extended_Return_Statement
;
5361 ----------------------------
5362 -- Expand_N_Function_Call --
5363 ----------------------------
5365 procedure Expand_N_Function_Call
(N
: Node_Id
) is
5368 end Expand_N_Function_Call
;
5370 ---------------------------------------
5371 -- Expand_N_Procedure_Call_Statement --
5372 ---------------------------------------
5374 procedure Expand_N_Procedure_Call_Statement
(N
: Node_Id
) is
5377 end Expand_N_Procedure_Call_Statement
;
5379 --------------------------------------
5380 -- Expand_N_Simple_Return_Statement --
5381 --------------------------------------
5383 procedure Expand_N_Simple_Return_Statement
(N
: Node_Id
) is
5385 -- Defend against previous errors (i.e. the return statement calls a
5386 -- function that is not available in configurable runtime).
5388 if Present
(Expression
(N
))
5389 and then Nkind
(Expression
(N
)) = N_Empty
5391 Check_Error_Detected
;
5395 -- Distinguish the function and non-function cases:
5397 case Ekind
(Return_Applies_To
(Return_Statement_Entity
(N
))) is
5399 | E_Generic_Function
5401 Expand_Simple_Function_Return
(N
);
5405 | E_Generic_Procedure
5407 | E_Return_Statement
5409 Expand_Non_Function_Return
(N
);
5412 raise Program_Error
;
5416 when RE_Not_Available
=>
5418 end Expand_N_Simple_Return_Statement
;
5420 ------------------------------
5421 -- Expand_N_Subprogram_Body --
5422 ------------------------------
5424 -- Add poll call if ATC polling is enabled, unless the body will be inlined
5427 -- Add dummy push/pop label nodes at start and end to clear any local
5428 -- exception indications if local-exception-to-goto optimization is active.
5430 -- Add return statement if last statement in body is not a return statement
5431 -- (this makes things easier on Gigi which does not want to have to handle
5432 -- a missing return).
5434 -- Add call to Activate_Tasks if body is a task activator
5436 -- Deal with possible detection of infinite recursion
5438 -- Eliminate body completely if convention stubbed
5440 -- Encode entity names within body, since we will not need to reference
5441 -- these entities any longer in the front end.
5443 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
5445 -- Reset Pure indication if any parameter has root type System.Address
5446 -- or has any parameters of limited types, where limited means that the
5447 -- run-time view is limited (i.e. the full type is limited).
5451 procedure Expand_N_Subprogram_Body
(N
: Node_Id
) is
5452 Body_Id
: constant Entity_Id
:= Defining_Entity
(N
);
5453 HSS
: constant Node_Id
:= Handled_Statement_Sequence
(N
);
5454 Loc
: constant Source_Ptr
:= Sloc
(N
);
5456 procedure Add_Return
(Spec_Id
: Entity_Id
; Stmts
: List_Id
);
5457 -- Append a return statement to the statement sequence Stmts if the last
5458 -- statement is not already a return or a goto statement. Note that the
5459 -- latter test is not critical, it does not matter if we add a few extra
5460 -- returns, since they get eliminated anyway later on. Spec_Id denotes
5461 -- the corresponding spec of the subprogram body.
5467 procedure Add_Return
(Spec_Id
: Entity_Id
; Stmts
: List_Id
) is
5468 Last_Stmt
: Node_Id
;
5473 -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
5474 -- not relevant in this context since they are not executable.
5476 Last_Stmt
:= Last
(Stmts
);
5477 while Nkind
(Last_Stmt
) in N_Pop_xxx_Label
loop
5481 -- Now insert return unless last statement is a transfer
5483 if not Is_Transfer
(Last_Stmt
) then
5485 -- The source location for the return is the end label of the
5486 -- procedure if present. Otherwise use the sloc of the last
5487 -- statement in the list. If the list comes from a generated
5488 -- exception handler and we are not debugging generated code,
5489 -- all the statements within the handler are made invisible
5492 if Nkind
(Parent
(Stmts
)) = N_Exception_Handler
5493 and then not Comes_From_Source
(Parent
(Stmts
))
5495 Loc
:= Sloc
(Last_Stmt
);
5496 elsif Present
(End_Label
(HSS
)) then
5497 Loc
:= Sloc
(End_Label
(HSS
));
5499 Loc
:= Sloc
(Last_Stmt
);
5502 -- Append return statement, and set analyzed manually. We can't
5503 -- call Analyze on this return since the scope is wrong.
5505 -- Note: it almost works to push the scope and then do the Analyze
5506 -- call, but something goes wrong in some weird cases and it is
5507 -- not worth worrying about ???
5509 Stmt
:= Make_Simple_Return_Statement
(Loc
);
5511 -- The return statement is handled properly, and the call to the
5512 -- postcondition, inserted below, does not require information
5513 -- from the body either. However, that call is analyzed in the
5514 -- enclosing scope, and an elaboration check might improperly be
5515 -- added to it. A guard in Sem_Elab is needed to prevent that
5516 -- spurious check, see Check_Elab_Call.
5518 Append_To
(Stmts
, Stmt
);
5519 Set_Analyzed
(Stmt
);
5521 -- Call the _Postconditions procedure if the related subprogram
5522 -- has contract assertions that need to be verified on exit.
5524 if Ekind
(Spec_Id
) = E_Procedure
5525 and then Present
(Postconditions_Proc
(Spec_Id
))
5527 Insert_Action
(Stmt
,
5528 Make_Procedure_Call_Statement
(Loc
,
5530 New_Occurrence_Of
(Postconditions_Proc
(Spec_Id
), Loc
)));
5539 Spec_Id
: Entity_Id
;
5541 -- Start of processing for Expand_N_Subprogram_Body
5544 if Present
(Corresponding_Spec
(N
)) then
5545 Spec_Id
:= Corresponding_Spec
(N
);
5550 -- If this is a Pure function which has any parameters whose root type
5551 -- is System.Address, reset the Pure indication.
5552 -- This check is also performed when the subprogram is frozen, but we
5553 -- repeat it on the body so that the indication is consistent, and so
5554 -- it applies as well to bodies without separate specifications.
5556 if Is_Pure
(Spec_Id
)
5557 and then Is_Subprogram
(Spec_Id
)
5558 and then not Has_Pragma_Pure_Function
(Spec_Id
)
5560 Check_Function_With_Address_Parameter
(Spec_Id
);
5562 if Spec_Id
/= Body_Id
then
5563 Set_Is_Pure
(Body_Id
, Is_Pure
(Spec_Id
));
5567 -- Set L to either the list of declarations if present, or to the list
5568 -- of statements if no declarations are present. This is used to insert
5569 -- new stuff at the start.
5571 if Is_Non_Empty_List
(Declarations
(N
)) then
5572 L
:= Declarations
(N
);
5574 L
:= Statements
(HSS
);
5577 -- If local-exception-to-goto optimization active, insert dummy push
5578 -- statements at start, and dummy pop statements at end, but inhibit
5579 -- this if we have No_Exception_Handlers, since they are useless and
5580 -- intefere with analysis, e.g. by codepeer.
5582 if (Debug_Flag_Dot_G
5583 or else Restriction_Active
(No_Exception_Propagation
))
5584 and then not Restriction_Active
(No_Exception_Handlers
)
5585 and then not CodePeer_Mode
5586 and then Is_Non_Empty_List
(L
)
5589 FS
: constant Node_Id
:= First
(L
);
5590 FL
: constant Source_Ptr
:= Sloc
(FS
);
5595 -- LS points to either last statement, if statements are present
5596 -- or to the last declaration if there are no statements present.
5597 -- It is the node after which the pop's are generated.
5599 if Is_Non_Empty_List
(Statements
(HSS
)) then
5600 LS
:= Last
(Statements
(HSS
));
5607 Insert_List_Before_And_Analyze
(FS
, New_List
(
5608 Make_Push_Constraint_Error_Label
(FL
),
5609 Make_Push_Program_Error_Label
(FL
),
5610 Make_Push_Storage_Error_Label
(FL
)));
5612 Insert_List_After_And_Analyze
(LS
, New_List
(
5613 Make_Pop_Constraint_Error_Label
(LL
),
5614 Make_Pop_Program_Error_Label
(LL
),
5615 Make_Pop_Storage_Error_Label
(LL
)));
5619 -- Need poll on entry to subprogram if polling enabled. We only do this
5620 -- for non-empty subprograms, since it does not seem necessary to poll
5621 -- for a dummy null subprogram.
5623 if Is_Non_Empty_List
(L
) then
5625 -- Do not add a polling call if the subprogram is to be inlined by
5626 -- the back-end, to avoid repeated calls with multiple inlinings.
5628 if Is_Inlined
(Spec_Id
)
5629 and then Front_End_Inlining
5630 and then Optimization_Level
> 1
5634 Generate_Poll_Call
(First
(L
));
5638 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
5640 if Init_Or_Norm_Scalars
and then Is_Subprogram
(Spec_Id
) then
5646 -- Loop through formals
5648 F
:= First_Formal
(Spec_Id
);
5649 while Present
(F
) loop
5650 if Is_Scalar_Type
(Etype
(F
))
5651 and then Ekind
(F
) = E_Out_Parameter
5653 Check_Restriction
(No_Default_Initialization
, F
);
5655 -- Insert the initialization. We turn off validity checks
5656 -- for this assignment, since we do not want any check on
5657 -- the initial value itself (which may well be invalid).
5658 -- Predicate checks are disabled as well (RM 6.4.1 (13/3))
5661 Make_Assignment_Statement
(Loc
,
5662 Name
=> New_Occurrence_Of
(F
, Loc
),
5663 Expression
=> Get_Simple_Init_Val
(Etype
(F
), N
));
5664 Set_Suppress_Assignment_Checks
(A
);
5666 Insert_Before_And_Analyze
(First
(L
),
5667 A
, Suppress
=> Validity_Check
);
5675 -- Clear out statement list for stubbed procedure
5677 if Present
(Corresponding_Spec
(N
)) then
5678 Set_Elaboration_Flag
(N
, Spec_Id
);
5680 if Convention
(Spec_Id
) = Convention_Stubbed
5681 or else Is_Eliminated
(Spec_Id
)
5683 Set_Declarations
(N
, Empty_List
);
5684 Set_Handled_Statement_Sequence
(N
,
5685 Make_Handled_Sequence_Of_Statements
(Loc
,
5686 Statements
=> New_List
(Make_Null_Statement
(Loc
))));
5692 -- Create a set of discriminals for the next protected subprogram body
5694 if Is_List_Member
(N
)
5695 and then Present
(Parent
(List_Containing
(N
)))
5696 and then Nkind
(Parent
(List_Containing
(N
))) = N_Protected_Body
5697 and then Present
(Next_Protected_Operation
(N
))
5699 Set_Discriminals
(Parent
(Base_Type
(Scope
(Spec_Id
))));
5702 -- Returns_By_Ref flag is normally set when the subprogram is frozen but
5703 -- subprograms with no specs are not frozen.
5706 Typ
: constant Entity_Id
:= Etype
(Spec_Id
);
5707 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
5710 if Is_Limited_View
(Typ
) then
5711 Set_Returns_By_Ref
(Spec_Id
);
5713 elsif Present
(Utyp
) and then CW_Or_Has_Controlled_Part
(Utyp
) then
5714 Set_Returns_By_Ref
(Spec_Id
);
5718 -- For a procedure, we add a return for all possible syntactic ends of
5721 if Ekind_In
(Spec_Id
, E_Procedure
, E_Generic_Procedure
) then
5722 Add_Return
(Spec_Id
, Statements
(HSS
));
5724 if Present
(Exception_Handlers
(HSS
)) then
5725 Except_H
:= First_Non_Pragma
(Exception_Handlers
(HSS
));
5726 while Present
(Except_H
) loop
5727 Add_Return
(Spec_Id
, Statements
(Except_H
));
5728 Next_Non_Pragma
(Except_H
);
5732 -- For a function, we must deal with the case where there is at least
5733 -- one missing return. What we do is to wrap the entire body of the
5734 -- function in a block:
5747 -- raise Program_Error;
5750 -- This approach is necessary because the raise must be signalled to the
5751 -- caller, not handled by any local handler (RM 6.4(11)).
5753 -- Note: we do not need to analyze the constructed sequence here, since
5754 -- it has no handler, and an attempt to analyze the handled statement
5755 -- sequence twice is risky in various ways (e.g. the issue of expanding
5756 -- cleanup actions twice).
5758 elsif Has_Missing_Return
(Spec_Id
) then
5760 Hloc
: constant Source_Ptr
:= Sloc
(HSS
);
5761 Blok
: constant Node_Id
:=
5762 Make_Block_Statement
(Hloc
,
5763 Handled_Statement_Sequence
=> HSS
);
5764 Rais
: constant Node_Id
:=
5765 Make_Raise_Program_Error
(Hloc
,
5766 Reason
=> PE_Missing_Return
);
5769 Set_Handled_Statement_Sequence
(N
,
5770 Make_Handled_Sequence_Of_Statements
(Hloc
,
5771 Statements
=> New_List
(Blok
, Rais
)));
5773 Push_Scope
(Spec_Id
);
5780 -- If subprogram contains a parameterless recursive call, then we may
5781 -- have an infinite recursion, so see if we can generate code to check
5782 -- for this possibility if storage checks are not suppressed.
5784 if Ekind
(Spec_Id
) = E_Procedure
5785 and then Has_Recursive_Call
(Spec_Id
)
5786 and then not Storage_Checks_Suppressed
(Spec_Id
)
5788 Detect_Infinite_Recursion
(N
, Spec_Id
);
5791 -- Set to encode entity names in package body before gigi is called
5793 Qualify_Entity_Names
(N
);
5795 -- If the body belongs to a nonabstract library-level source primitive
5796 -- of a tagged type, install an elaboration check which ensures that a
5797 -- dispatching call targeting the primitive will not execute the body
5798 -- without it being previously elaborated.
5800 Install_Primitive_Elaboration_Check
(N
);
5801 end Expand_N_Subprogram_Body
;
5803 -----------------------------------
5804 -- Expand_N_Subprogram_Body_Stub --
5805 -----------------------------------
5807 procedure Expand_N_Subprogram_Body_Stub
(N
: Node_Id
) is
5811 if Present
(Corresponding_Body
(N
)) then
5812 Bod
:= Unit_Declaration_Node
(Corresponding_Body
(N
));
5814 -- The body may have been expanded already when it is analyzed
5815 -- through the subunit node. Do no expand again: it interferes
5816 -- with the construction of unnesting tables when generating C.
5818 if not Analyzed
(Bod
) then
5819 Expand_N_Subprogram_Body
(Bod
);
5822 -- Add full qualification to entities that may be created late
5823 -- during unnesting.
5825 Qualify_Entity_Names
(N
);
5827 end Expand_N_Subprogram_Body_Stub
;
5829 -------------------------------------
5830 -- Expand_N_Subprogram_Declaration --
5831 -------------------------------------
5833 -- If the declaration appears within a protected body, it is a private
5834 -- operation of the protected type. We must create the corresponding
5835 -- protected subprogram an associated formals. For a normal protected
5836 -- operation, this is done when expanding the protected type declaration.
5838 -- If the declaration is for a null procedure, emit null body
5840 procedure Expand_N_Subprogram_Declaration
(N
: Node_Id
) is
5841 Loc
: constant Source_Ptr
:= Sloc
(N
);
5842 Subp
: constant Entity_Id
:= Defining_Entity
(N
);
5846 Scop
: constant Entity_Id
:= Scope
(Subp
);
5848 Prot_Decl
: Node_Id
;
5849 Prot_Id
: Entity_Id
;
5851 -- Start of processing for Expand_N_Subprogram_Declaration
5854 -- In SPARK, subprogram declarations are only allowed in package
5857 if Nkind
(Parent
(N
)) /= N_Package_Specification
then
5858 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
5859 Check_SPARK_05_Restriction
5860 ("subprogram declaration is not a library item", N
);
5862 elsif Present
(Next
(N
))
5863 and then Nkind
(Next
(N
)) = N_Pragma
5864 and then Get_Pragma_Id
(Next
(N
)) = Pragma_Import
5866 -- In SPARK, subprogram declarations are also permitted in
5867 -- declarative parts when immediately followed by a corresponding
5868 -- pragma Import. We only check here that there is some pragma
5873 Check_SPARK_05_Restriction
5874 ("subprogram declaration is not allowed here", N
);
5878 -- Deal with case of protected subprogram. Do not generate protected
5879 -- operation if operation is flagged as eliminated.
5881 if Is_List_Member
(N
)
5882 and then Present
(Parent
(List_Containing
(N
)))
5883 and then Nkind
(Parent
(List_Containing
(N
))) = N_Protected_Body
5884 and then Is_Protected_Type
(Scop
)
5886 if No
(Protected_Body_Subprogram
(Subp
))
5887 and then not Is_Eliminated
(Subp
)
5890 Make_Subprogram_Declaration
(Loc
,
5892 Build_Protected_Sub_Specification
5893 (N
, Scop
, Unprotected_Mode
));
5895 -- The protected subprogram is declared outside of the protected
5896 -- body. Given that the body has frozen all entities so far, we
5897 -- analyze the subprogram and perform freezing actions explicitly.
5898 -- including the generation of an explicit freeze node, to ensure
5899 -- that gigi has the proper order of elaboration.
5900 -- If the body is a subunit, the insertion point is before the
5901 -- stub in the parent.
5903 Prot_Bod
:= Parent
(List_Containing
(N
));
5905 if Nkind
(Parent
(Prot_Bod
)) = N_Subunit
then
5906 Prot_Bod
:= Corresponding_Stub
(Parent
(Prot_Bod
));
5909 Insert_Before
(Prot_Bod
, Prot_Decl
);
5910 Prot_Id
:= Defining_Unit_Name
(Specification
(Prot_Decl
));
5911 Set_Has_Delayed_Freeze
(Prot_Id
);
5913 Push_Scope
(Scope
(Scop
));
5914 Analyze
(Prot_Decl
);
5915 Freeze_Before
(N
, Prot_Id
);
5916 Set_Protected_Body_Subprogram
(Subp
, Prot_Id
);
5918 -- Create protected operation as well. Even though the operation
5919 -- is only accessible within the body, it is possible to make it
5920 -- available outside of the protected object by using 'Access to
5921 -- provide a callback, so build protected version in all cases.
5924 Make_Subprogram_Declaration
(Loc
,
5926 Build_Protected_Sub_Specification
(N
, Scop
, Protected_Mode
));
5927 Insert_Before
(Prot_Bod
, Prot_Decl
);
5928 Analyze
(Prot_Decl
);
5933 -- Ada 2005 (AI-348): Generate body for a null procedure. In most
5934 -- cases this is superfluous because calls to it will be automatically
5935 -- inlined, but we definitely need the body if preconditions for the
5936 -- procedure are present, or if performing coverage analysis.
5938 elsif Nkind
(Specification
(N
)) = N_Procedure_Specification
5939 and then Null_Present
(Specification
(N
))
5942 Bod
: constant Node_Id
:= Body_To_Inline
(N
);
5945 Set_Has_Completion
(Subp
, False);
5946 Append_Freeze_Action
(Subp
, Bod
);
5948 -- The body now contains raise statements, so calls to it will
5951 Set_Is_Inlined
(Subp
, False);
5955 -- When generating C code, transform a function that returns a
5956 -- constrained array type into a procedure with an out parameter
5957 -- that carries the return value.
5959 -- We skip this transformation for unchecked conversions, since they
5960 -- are not needed by the C generator (and this also produces cleaner
5963 if Modify_Tree_For_C
5964 and then Nkind
(Specification
(N
)) = N_Function_Specification
5965 and then Is_Array_Type
(Etype
(Subp
))
5966 and then Is_Constrained
(Etype
(Subp
))
5967 and then not Is_Unchecked_Conversion_Instance
(Subp
)
5969 Build_Procedure_Form
(N
);
5971 end Expand_N_Subprogram_Declaration
;
5973 --------------------------------
5974 -- Expand_Non_Function_Return --
5975 --------------------------------
5977 procedure Expand_Non_Function_Return
(N
: Node_Id
) is
5978 pragma Assert
(No
(Expression
(N
)));
5980 Loc
: constant Source_Ptr
:= Sloc
(N
);
5981 Scope_Id
: Entity_Id
:= Return_Applies_To
(Return_Statement_Entity
(N
));
5982 Kind
: constant Entity_Kind
:= Ekind
(Scope_Id
);
5985 Goto_Stat
: Node_Id
;
5989 -- Call the _Postconditions procedure if the related subprogram has
5990 -- contract assertions that need to be verified on exit.
5992 if Ekind_In
(Scope_Id
, E_Entry
, E_Entry_Family
, E_Procedure
)
5993 and then Present
(Postconditions_Proc
(Scope_Id
))
5996 Make_Procedure_Call_Statement
(Loc
,
5997 Name
=> New_Occurrence_Of
(Postconditions_Proc
(Scope_Id
), Loc
)));
6000 -- If it is a return from a procedure do no extra steps
6002 if Kind
= E_Procedure
or else Kind
= E_Generic_Procedure
then
6005 -- If it is a nested return within an extended one, replace it with a
6006 -- return of the previously declared return object.
6008 elsif Kind
= E_Return_Statement
then
6010 Make_Simple_Return_Statement
(Loc
,
6012 New_Occurrence_Of
(First_Entity
(Scope_Id
), Loc
)));
6013 Set_Comes_From_Extended_Return_Statement
(N
);
6014 Set_Return_Statement_Entity
(N
, Scope_Id
);
6015 Expand_Simple_Function_Return
(N
);
6019 pragma Assert
(Is_Entry
(Scope_Id
));
6021 -- Look at the enclosing block to see whether the return is from an
6022 -- accept statement or an entry body.
6024 for J
in reverse 0 .. Scope_Stack
.Last
loop
6025 Scope_Id
:= Scope_Stack
.Table
(J
).Entity
;
6026 exit when Is_Concurrent_Type
(Scope_Id
);
6029 -- If it is a return from accept statement it is expanded as call to
6030 -- RTS Complete_Rendezvous and a goto to the end of the accept body.
6032 -- (cf : Expand_N_Accept_Statement, Expand_N_Selective_Accept,
6033 -- Expand_N_Accept_Alternative in exp_ch9.adb)
6035 if Is_Task_Type
(Scope_Id
) then
6038 Make_Procedure_Call_Statement
(Loc
,
6039 Name
=> New_Occurrence_Of
(RTE
(RE_Complete_Rendezvous
), Loc
));
6040 Insert_Before
(N
, Call
);
6041 -- why not insert actions here???
6044 Acc_Stat
:= Parent
(N
);
6045 while Nkind
(Acc_Stat
) /= N_Accept_Statement
loop
6046 Acc_Stat
:= Parent
(Acc_Stat
);
6049 Lab_Node
:= Last
(Statements
6050 (Handled_Statement_Sequence
(Acc_Stat
)));
6052 Goto_Stat
:= Make_Goto_Statement
(Loc
,
6053 Name
=> New_Occurrence_Of
6054 (Entity
(Identifier
(Lab_Node
)), Loc
));
6056 Set_Analyzed
(Goto_Stat
);
6058 Rewrite
(N
, Goto_Stat
);
6061 -- If it is a return from an entry body, put a Complete_Entry_Body call
6062 -- in front of the return.
6064 elsif Is_Protected_Type
(Scope_Id
) then
6066 Make_Procedure_Call_Statement
(Loc
,
6068 New_Occurrence_Of
(RTE
(RE_Complete_Entry_Body
), Loc
),
6069 Parameter_Associations
=> New_List
(
6070 Make_Attribute_Reference
(Loc
,
6073 (Find_Protection_Object
(Current_Scope
), Loc
),
6074 Attribute_Name
=> Name_Unchecked_Access
)));
6076 Insert_Before
(N
, Call
);
6079 end Expand_Non_Function_Return
;
6081 ---------------------------------------
6082 -- Expand_Protected_Object_Reference --
6083 ---------------------------------------
6085 function Expand_Protected_Object_Reference
6087 Scop
: Entity_Id
) return Node_Id
6089 Loc
: constant Source_Ptr
:= Sloc
(N
);
6096 Rec
:= Make_Identifier
(Loc
, Name_uObject
);
6097 Set_Etype
(Rec
, Corresponding_Record_Type
(Scop
));
6099 -- Find enclosing protected operation, and retrieve its first parameter,
6100 -- which denotes the enclosing protected object. If the enclosing
6101 -- operation is an entry, we are immediately within the protected body,
6102 -- and we can retrieve the object from the service entries procedure. A
6103 -- barrier function has the same signature as an entry. A barrier
6104 -- function is compiled within the protected object, but unlike
6105 -- protected operations its never needs locks, so that its protected
6106 -- body subprogram points to itself.
6108 Proc
:= Current_Scope
;
6109 while Present
(Proc
)
6110 and then Scope
(Proc
) /= Scop
6112 Proc
:= Scope
(Proc
);
6115 Corr
:= Protected_Body_Subprogram
(Proc
);
6119 -- Previous error left expansion incomplete.
6120 -- Nothing to do on this call.
6127 (First
(Parameter_Specifications
(Parent
(Corr
))));
6129 if Is_Subprogram
(Proc
) and then Proc
/= Corr
then
6131 -- Protected function or procedure
6133 Set_Entity
(Rec
, Param
);
6135 -- Rec is a reference to an entity which will not be in scope when
6136 -- the call is reanalyzed, and needs no further analysis.
6141 -- Entry or barrier function for entry body. The first parameter of
6142 -- the entry body procedure is pointer to the object. We create a
6143 -- local variable of the proper type, duplicating what is done to
6144 -- define _object later on.
6148 Obj_Ptr
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
6152 Make_Full_Type_Declaration
(Loc
,
6153 Defining_Identifier
=> Obj_Ptr
,
6155 Make_Access_To_Object_Definition
(Loc
,
6156 Subtype_Indication
=>
6158 (Corresponding_Record_Type
(Scop
), Loc
))));
6160 Insert_Actions
(N
, Decls
);
6161 Freeze_Before
(N
, Obj_Ptr
);
6164 Make_Explicit_Dereference
(Loc
,
6166 Unchecked_Convert_To
(Obj_Ptr
,
6167 New_Occurrence_Of
(Param
, Loc
)));
6169 -- Analyze new actual. Other actuals in calls are already analyzed
6170 -- and the list of actuals is not reanalyzed after rewriting.
6172 Set_Parent
(Rec
, N
);
6178 end Expand_Protected_Object_Reference
;
6180 --------------------------------------
6181 -- Expand_Protected_Subprogram_Call --
6182 --------------------------------------
6184 procedure Expand_Protected_Subprogram_Call
6191 procedure Expand_Internal_Init_Call
;
6192 -- A call to an operation of the type may occur in the initialization
6193 -- of a private component. In that case the prefix of the call is an
6194 -- entity name and the call is treated as internal even though it
6195 -- appears in code outside of the protected type.
6197 procedure Freeze_Called_Function
;
6198 -- If it is a function call it can appear in elaboration code and
6199 -- the called entity must be frozen before the call. This must be
6200 -- done before the call is expanded, as the expansion may rewrite it
6201 -- to something other than a call (e.g. a temporary initialized in a
6202 -- transient block).
6204 -------------------------------
6205 -- Expand_Internal_Init_Call --
6206 -------------------------------
6208 procedure Expand_Internal_Init_Call
is
6210 -- If the context is a protected object (rather than a protected
6211 -- type) the call itself is bound to raise program_error because
6212 -- the protected body will not have been elaborated yet. This is
6213 -- diagnosed subsequently in Sem_Elab.
6215 Freeze_Called_Function
;
6217 -- The target of the internal call is the first formal of the
6218 -- enclosing initialization procedure.
6220 Rec
:= New_Occurrence_Of
(First_Formal
(Current_Scope
), Sloc
(N
));
6221 Build_Protected_Subprogram_Call
(N
,
6226 Resolve
(N
, Etype
(Subp
));
6227 end Expand_Internal_Init_Call
;
6229 ----------------------------
6230 -- Freeze_Called_Function --
6231 ----------------------------
6233 procedure Freeze_Called_Function
is
6235 if Ekind
(Subp
) = E_Function
then
6236 Freeze_Expression
(Name
(N
));
6238 end Freeze_Called_Function
;
6240 -- Start of processing for Expand_Protected_Subprogram_Call
6243 -- If the protected object is not an enclosing scope, this is an inter-
6244 -- object function call. Inter-object procedure calls are expanded by
6245 -- Exp_Ch9.Build_Simple_Entry_Call. The call is intra-object only if the
6246 -- subprogram being called is in the protected body being compiled, and
6247 -- if the protected object in the call is statically the enclosing type.
6248 -- The object may be a component of some other data structure, in which
6249 -- case this must be handled as an inter-object call.
6251 if not In_Open_Scopes
(Scop
)
6252 or else Is_Entry_Wrapper
(Current_Scope
)
6253 or else not Is_Entity_Name
(Name
(N
))
6255 if Nkind
(Name
(N
)) = N_Selected_Component
then
6256 Rec
:= Prefix
(Name
(N
));
6258 elsif Nkind
(Name
(N
)) = N_Indexed_Component
then
6259 Rec
:= Prefix
(Prefix
(Name
(N
)));
6261 -- If this is a call within an entry wrapper, it appears within a
6262 -- precondition that calls another primitive of the synchronized
6263 -- type. The target object of the call is the first actual on the
6264 -- wrapper. Note that this is an external call, because the wrapper
6265 -- is called outside of the synchronized object. This means that
6266 -- an entry call to an entry with preconditions involves two
6267 -- synchronized operations.
6269 elsif Ekind
(Current_Scope
) = E_Procedure
6270 and then Is_Entry_Wrapper
(Current_Scope
)
6272 Rec
:= New_Occurrence_Of
(First_Entity
(Current_Scope
), Sloc
(N
));
6275 -- If the context is the initialization procedure for a protected
6276 -- type, the call is legal because the called entity must be a
6277 -- function of that enclosing type, and this is treated as an
6281 (Is_Entity_Name
(Name
(N
)) and then Inside_Init_Proc
);
6283 Expand_Internal_Init_Call
;
6287 Freeze_Called_Function
;
6288 Build_Protected_Subprogram_Call
(N
,
6289 Name
=> New_Occurrence_Of
(Subp
, Sloc
(N
)),
6290 Rec
=> Convert_Concurrent
(Rec
, Etype
(Rec
)),
6294 Rec
:= Expand_Protected_Object_Reference
(N
, Scop
);
6300 Freeze_Called_Function
;
6301 Build_Protected_Subprogram_Call
(N
,
6307 -- Analyze and resolve the new call. The actuals have already been
6308 -- resolved, but expansion of a function call will add extra actuals
6309 -- if needed. Analysis of a procedure call already includes resolution.
6313 if Ekind
(Subp
) = E_Function
then
6314 Resolve
(N
, Etype
(Subp
));
6316 end Expand_Protected_Subprogram_Call
;
6318 -----------------------------------
6319 -- Expand_Simple_Function_Return --
6320 -----------------------------------
6322 -- The "simple" comes from the syntax rule simple_return_statement. The
6323 -- semantics are not at all simple.
6325 procedure Expand_Simple_Function_Return
(N
: Node_Id
) is
6326 Loc
: constant Source_Ptr
:= Sloc
(N
);
6328 Scope_Id
: constant Entity_Id
:=
6329 Return_Applies_To
(Return_Statement_Entity
(N
));
6330 -- The function we are returning from
6332 R_Type
: constant Entity_Id
:= Etype
(Scope_Id
);
6333 -- The result type of the function
6335 Utyp
: constant Entity_Id
:= Underlying_Type
(R_Type
);
6337 Exp
: Node_Id
:= Expression
(N
);
6338 pragma Assert
(Present
(Exp
));
6340 Exptyp
: constant Entity_Id
:= Etype
(Exp
);
6341 -- The type of the expression (not necessarily the same as R_Type)
6343 Subtype_Ind
: Node_Id
;
6344 -- If the result type of the function is class-wide and the expression
6345 -- has a specific type, then we use the expression's type as the type of
6346 -- the return object. In cases where the expression is an aggregate that
6347 -- is built in place, this avoids the need for an expensive conversion
6348 -- of the return object to the specific type on assignments to the
6349 -- individual components.
6352 if Is_Class_Wide_Type
(R_Type
)
6353 and then not Is_Class_Wide_Type
(Exptyp
)
6354 and then Nkind
(Exp
) /= N_Type_Conversion
6356 Subtype_Ind
:= New_Occurrence_Of
(Exptyp
, Loc
);
6358 Subtype_Ind
:= New_Occurrence_Of
(R_Type
, Loc
);
6360 -- If the result type is class-wide and the expression is a view
6361 -- conversion, the conversion plays no role in the expansion because
6362 -- it does not modify the tag of the object. Remove the conversion
6363 -- altogether to prevent tag overwriting.
6365 if Is_Class_Wide_Type
(R_Type
)
6366 and then not Is_Class_Wide_Type
(Exptyp
)
6367 and then Nkind
(Exp
) = N_Type_Conversion
6369 Exp
:= Expression
(Exp
);
6373 -- For the case of a simple return that does not come from an extended
6374 -- return, in the case of Ada 2005 where we are returning a limited
6375 -- type, we rewrite "return <expression>;" to be:
6377 -- return _anon_ : <return_subtype> := <expression>
6379 -- The expansion produced by Expand_N_Extended_Return_Statement will
6380 -- contain simple return statements (for example, a block containing
6381 -- simple return of the return object), which brings us back here with
6382 -- Comes_From_Extended_Return_Statement set. The reason for the barrier
6383 -- checking for a simple return that does not come from an extended
6384 -- return is to avoid this infinite recursion.
6386 -- The reason for this design is that for Ada 2005 limited returns, we
6387 -- need to reify the return object, so we can build it "in place", and
6388 -- we need a block statement to hang finalization and tasking stuff.
6390 -- ??? In order to avoid disruption, we avoid translating to extended
6391 -- return except in the cases where we really need to (Ada 2005 for
6392 -- inherently limited). We might prefer to do this translation in all
6393 -- cases (except perhaps for the case of Ada 95 inherently limited),
6394 -- in order to fully exercise the Expand_N_Extended_Return_Statement
6395 -- code. This would also allow us to do the build-in-place optimization
6396 -- for efficiency even in cases where it is semantically not required.
6398 -- As before, we check the type of the return expression rather than the
6399 -- return type of the function, because the latter may be a limited
6400 -- class-wide interface type, which is not a limited type, even though
6401 -- the type of the expression may be.
6403 if not Comes_From_Extended_Return_Statement
(N
)
6404 and then Is_Limited_View
(Etype
(Expression
(N
)))
6405 and then Ada_Version
>= Ada_2005
6406 and then not Debug_Flag_Dot_L
6408 -- The functionality of interface thunks is simple and it is always
6409 -- handled by means of simple return statements. This leaves their
6410 -- expansion simple and clean.
6412 and then not Is_Thunk
(Current_Scope
)
6415 Return_Object_Entity
: constant Entity_Id
:=
6416 Make_Temporary
(Loc
, 'R', Exp
);
6418 Obj_Decl
: constant Node_Id
:=
6419 Make_Object_Declaration
(Loc
,
6420 Defining_Identifier
=> Return_Object_Entity
,
6421 Object_Definition
=> Subtype_Ind
,
6424 Ext
: constant Node_Id
:=
6425 Make_Extended_Return_Statement
(Loc
,
6426 Return_Object_Declarations
=> New_List
(Obj_Decl
));
6427 -- Do not perform this high-level optimization if the result type
6428 -- is an interface because the "this" pointer must be displaced.
6437 -- Here we have a simple return statement that is part of the expansion
6438 -- of an extended return statement (either written by the user, or
6439 -- generated by the above code).
6441 -- Always normalize C/Fortran boolean result. This is not always needed,
6442 -- but it seems a good idea to minimize the passing around of non-
6443 -- normalized values, and in any case this handles the processing of
6444 -- barrier functions for protected types, which turn the condition into
6445 -- a return statement.
6447 if Is_Boolean_Type
(Exptyp
)
6448 and then Nonzero_Is_True
(Exptyp
)
6450 Adjust_Condition
(Exp
);
6451 Adjust_Result_Type
(Exp
, Exptyp
);
6454 -- Do validity check if enabled for returns
6456 if Validity_Checks_On
6457 and then Validity_Check_Returns
6462 -- Check the result expression of a scalar function against the subtype
6463 -- of the function by inserting a conversion. This conversion must
6464 -- eventually be performed for other classes of types, but for now it's
6465 -- only done for scalars.
6468 if Is_Scalar_Type
(Exptyp
) then
6469 Rewrite
(Exp
, Convert_To
(R_Type
, Exp
));
6471 -- The expression is resolved to ensure that the conversion gets
6472 -- expanded to generate a possible constraint check.
6474 Analyze_And_Resolve
(Exp
, R_Type
);
6477 -- Deal with returning variable length objects and controlled types
6479 -- Nothing to do if we are returning by reference, or this is not a
6480 -- type that requires special processing (indicated by the fact that
6481 -- it requires a cleanup scope for the secondary stack case).
6483 if Is_Limited_View
(Exptyp
)
6484 or else Is_Limited_Interface
(Exptyp
)
6488 -- No copy needed for thunks returning interface type objects since
6489 -- the object is returned by reference and the maximum functionality
6490 -- required is just to displace the pointer.
6492 elsif Is_Thunk
(Current_Scope
) and then Is_Interface
(Exptyp
) then
6495 -- If the call is within a thunk and the type is a limited view, the
6496 -- backend will eventually see the non-limited view of the type.
6498 elsif Is_Thunk
(Current_Scope
) and then Is_Incomplete_Type
(Exptyp
) then
6501 elsif not Requires_Transient_Scope
(R_Type
) then
6503 -- Mutable records with variable-length components are not returned
6504 -- on the sec-stack, so we need to make sure that the back end will
6505 -- only copy back the size of the actual value, and not the maximum
6506 -- size. We create an actual subtype for this purpose. However we
6507 -- need not do it if the expression is a function call since this
6508 -- will be done in the called function and doing it here too would
6509 -- cause a temporary with maximum size to be created.
6512 Ubt
: constant Entity_Id
:= Underlying_Type
(Base_Type
(Exptyp
));
6516 if Nkind
(Exp
) /= N_Function_Call
6517 and then Has_Discriminants
(Ubt
)
6518 and then not Is_Constrained
(Ubt
)
6519 and then not Has_Unchecked_Union
(Ubt
)
6521 Decl
:= Build_Actual_Subtype
(Ubt
, Exp
);
6522 Ent
:= Defining_Identifier
(Decl
);
6523 Insert_Action
(Exp
, Decl
);
6524 Rewrite
(Exp
, Unchecked_Convert_To
(Ent
, Exp
));
6525 Analyze_And_Resolve
(Exp
);
6529 -- Here if secondary stack is used
6532 -- Prevent the reclamation of the secondary stack by all enclosing
6533 -- blocks and loops as well as the related function; otherwise the
6534 -- result would be reclaimed too early.
6536 Set_Enclosing_Sec_Stack_Return
(N
);
6538 -- Optimize the case where the result is a function call. In this
6539 -- case either the result is already on the secondary stack, or is
6540 -- already being returned with the stack pointer depressed and no
6541 -- further processing is required except to set the By_Ref flag
6542 -- to ensure that gigi does not attempt an extra unnecessary copy.
6543 -- (actually not just unnecessary but harmfully wrong in the case
6544 -- of a controlled type, where gigi does not know how to do a copy).
6545 -- To make up for a gcc 2.8.1 deficiency (???), we perform the copy
6546 -- for array types if the constrained status of the target type is
6547 -- different from that of the expression.
6549 if Requires_Transient_Scope
(Exptyp
)
6551 (not Is_Array_Type
(Exptyp
)
6552 or else Is_Constrained
(Exptyp
) = Is_Constrained
(R_Type
)
6553 or else CW_Or_Has_Controlled_Part
(Utyp
))
6554 and then Nkind
(Exp
) = N_Function_Call
6558 -- Remove side effects from the expression now so that other parts
6559 -- of the expander do not have to reanalyze this node without this
6562 Rewrite
(Exp
, Duplicate_Subexpr_No_Checks
(Exp
));
6564 -- Ada 2005 (AI-251): If the type of the returned object is
6565 -- an interface then add an implicit type conversion to force
6566 -- displacement of the "this" pointer.
6568 if Is_Interface
(R_Type
) then
6569 Rewrite
(Exp
, Convert_To
(R_Type
, Relocate_Node
(Exp
)));
6572 Analyze_And_Resolve
(Exp
, R_Type
);
6574 -- For controlled types, do the allocation on the secondary stack
6575 -- manually in order to call adjust at the right time:
6577 -- type Anon1 is access R_Type;
6578 -- for Anon1'Storage_pool use ss_pool;
6579 -- Anon2 : anon1 := new R_Type'(expr);
6580 -- return Anon2.all;
6582 -- We do the same for classwide types that are not potentially
6583 -- controlled (by the virtue of restriction No_Finalization) because
6584 -- gigi is not able to properly allocate class-wide types.
6586 elsif CW_Or_Has_Controlled_Part
(Utyp
) then
6588 Loc
: constant Source_Ptr
:= Sloc
(N
);
6589 Acc_Typ
: constant Entity_Id
:= Make_Temporary
(Loc
, 'A');
6590 Alloc_Node
: Node_Id
;
6594 Set_Ekind
(Acc_Typ
, E_Access_Type
);
6596 Set_Associated_Storage_Pool
(Acc_Typ
, RTE
(RE_SS_Pool
));
6598 -- This is an allocator for the secondary stack, and it's fine
6599 -- to have Comes_From_Source set False on it, as gigi knows not
6600 -- to flag it as a violation of No_Implicit_Heap_Allocations.
6603 Make_Allocator
(Loc
,
6605 Make_Qualified_Expression
(Loc
,
6606 Subtype_Mark
=> New_Occurrence_Of
(Etype
(Exp
), Loc
),
6607 Expression
=> Relocate_Node
(Exp
)));
6609 -- We do not want discriminant checks on the declaration,
6610 -- given that it gets its value from the allocator.
6612 Set_No_Initialization
(Alloc_Node
);
6614 Temp
:= Make_Temporary
(Loc
, 'R', Alloc_Node
);
6616 Insert_List_Before_And_Analyze
(N
, New_List
(
6617 Make_Full_Type_Declaration
(Loc
,
6618 Defining_Identifier
=> Acc_Typ
,
6620 Make_Access_To_Object_Definition
(Loc
,
6621 Subtype_Indication
=> Subtype_Ind
)),
6623 Make_Object_Declaration
(Loc
,
6624 Defining_Identifier
=> Temp
,
6625 Object_Definition
=> New_Occurrence_Of
(Acc_Typ
, Loc
),
6626 Expression
=> Alloc_Node
)));
6629 Make_Explicit_Dereference
(Loc
,
6630 Prefix
=> New_Occurrence_Of
(Temp
, Loc
)));
6632 -- Ada 2005 (AI-251): If the type of the returned object is
6633 -- an interface then add an implicit type conversion to force
6634 -- displacement of the "this" pointer.
6636 if Is_Interface
(R_Type
) then
6637 Rewrite
(Exp
, Convert_To
(R_Type
, Relocate_Node
(Exp
)));
6640 Analyze_And_Resolve
(Exp
, R_Type
);
6643 -- Otherwise use the gigi mechanism to allocate result on the
6647 Check_Restriction
(No_Secondary_Stack
, N
);
6648 Set_Storage_Pool
(N
, RTE
(RE_SS_Pool
));
6649 Set_Procedure_To_Call
(N
, RTE
(RE_SS_Allocate
));
6653 -- Implement the rules of 6.5(8-10), which require a tag check in
6654 -- the case of a limited tagged return type, and tag reassignment for
6655 -- nonlimited tagged results. These actions are needed when the return
6656 -- type is a specific tagged type and the result expression is a
6657 -- conversion or a formal parameter, because in that case the tag of
6658 -- the expression might differ from the tag of the specific result type.
6660 if Is_Tagged_Type
(Utyp
)
6661 and then not Is_Class_Wide_Type
(Utyp
)
6662 and then (Nkind_In
(Exp
, N_Type_Conversion
,
6663 N_Unchecked_Type_Conversion
)
6664 or else (Is_Entity_Name
(Exp
)
6665 and then Ekind
(Entity
(Exp
)) in Formal_Kind
))
6667 -- When the return type is limited, perform a check that the tag of
6668 -- the result is the same as the tag of the return type.
6670 if Is_Limited_Type
(R_Type
) then
6672 Make_Raise_Constraint_Error
(Loc
,
6676 Make_Selected_Component
(Loc
,
6677 Prefix
=> Duplicate_Subexpr
(Exp
),
6678 Selector_Name
=> Make_Identifier
(Loc
, Name_uTag
)),
6680 Make_Attribute_Reference
(Loc
,
6682 New_Occurrence_Of
(Base_Type
(Utyp
), Loc
),
6683 Attribute_Name
=> Name_Tag
)),
6684 Reason
=> CE_Tag_Check_Failed
));
6686 -- If the result type is a specific nonlimited tagged type, then we
6687 -- have to ensure that the tag of the result is that of the result
6688 -- type. This is handled by making a copy of the expression in
6689 -- the case where it might have a different tag, namely when the
6690 -- expression is a conversion or a formal parameter. We create a new
6691 -- object of the result type and initialize it from the expression,
6692 -- which will implicitly force the tag to be set appropriately.
6696 ExpR
: constant Node_Id
:= Relocate_Node
(Exp
);
6697 Result_Id
: constant Entity_Id
:=
6698 Make_Temporary
(Loc
, 'R', ExpR
);
6699 Result_Exp
: constant Node_Id
:=
6700 New_Occurrence_Of
(Result_Id
, Loc
);
6701 Result_Obj
: constant Node_Id
:=
6702 Make_Object_Declaration
(Loc
,
6703 Defining_Identifier
=> Result_Id
,
6704 Object_Definition
=>
6705 New_Occurrence_Of
(R_Type
, Loc
),
6706 Constant_Present
=> True,
6707 Expression
=> ExpR
);
6710 Set_Assignment_OK
(Result_Obj
);
6711 Insert_Action
(Exp
, Result_Obj
);
6713 Rewrite
(Exp
, Result_Exp
);
6714 Analyze_And_Resolve
(Exp
, R_Type
);
6718 -- Ada 2005 (AI-344): If the result type is class-wide, then insert
6719 -- a check that the level of the return expression's underlying type
6720 -- is not deeper than the level of the master enclosing the function.
6721 -- Always generate the check when the type of the return expression
6722 -- is class-wide, when it's a type conversion, or when it's a formal
6723 -- parameter. Otherwise, suppress the check in the case where the
6724 -- return expression has a specific type whose level is known not to
6725 -- be statically deeper than the function's result type.
6727 -- No runtime check needed in interface thunks since it is performed
6728 -- by the target primitive associated with the thunk.
6730 -- Note: accessibility check is skipped in the VM case, since there
6731 -- does not seem to be any practical way to implement this check.
6733 elsif Ada_Version
>= Ada_2005
6734 and then Tagged_Type_Expansion
6735 and then Is_Class_Wide_Type
(R_Type
)
6736 and then not Is_Thunk
(Current_Scope
)
6737 and then not Scope_Suppress
.Suppress
(Accessibility_Check
)
6739 (Is_Class_Wide_Type
(Etype
(Exp
))
6740 or else Nkind_In
(Exp
, N_Type_Conversion
,
6741 N_Unchecked_Type_Conversion
)
6742 or else (Is_Entity_Name
(Exp
)
6743 and then Ekind
(Entity
(Exp
)) in Formal_Kind
)
6744 or else Scope_Depth
(Enclosing_Dynamic_Scope
(Etype
(Exp
))) >
6745 Scope_Depth
(Enclosing_Dynamic_Scope
(Scope_Id
)))
6751 -- Ada 2005 (AI-251): In class-wide interface objects we displace
6752 -- "this" to reference the base of the object. This is required to
6753 -- get access to the TSD of the object.
6755 if Is_Class_Wide_Type
(Etype
(Exp
))
6756 and then Is_Interface
(Etype
(Exp
))
6758 -- If the expression is an explicit dereference then we can
6759 -- directly displace the pointer to reference the base of
6762 if Nkind
(Exp
) = N_Explicit_Dereference
then
6764 Make_Explicit_Dereference
(Loc
,
6766 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6767 Make_Function_Call
(Loc
,
6769 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6770 Parameter_Associations
=> New_List
(
6771 Unchecked_Convert_To
(RTE
(RE_Address
),
6772 Duplicate_Subexpr
(Prefix
(Exp
)))))));
6774 -- Similar case to the previous one but the expression is a
6775 -- renaming of an explicit dereference.
6777 elsif Nkind
(Exp
) = N_Identifier
6778 and then Present
(Renamed_Object
(Entity
(Exp
)))
6779 and then Nkind
(Renamed_Object
(Entity
(Exp
)))
6780 = N_Explicit_Dereference
6783 Make_Explicit_Dereference
(Loc
,
6785 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6786 Make_Function_Call
(Loc
,
6788 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6789 Parameter_Associations
=> New_List
(
6790 Unchecked_Convert_To
(RTE
(RE_Address
),
6793 (Renamed_Object
(Entity
(Exp
)))))))));
6795 -- Common case: obtain the address of the actual object and
6796 -- displace the pointer to reference the base of the object.
6800 Make_Explicit_Dereference
(Loc
,
6802 Unchecked_Convert_To
(RTE
(RE_Tag_Ptr
),
6803 Make_Function_Call
(Loc
,
6805 New_Occurrence_Of
(RTE
(RE_Base_Address
), Loc
),
6806 Parameter_Associations
=> New_List
(
6807 Make_Attribute_Reference
(Loc
,
6808 Prefix
=> Duplicate_Subexpr
(Exp
),
6809 Attribute_Name
=> Name_Address
)))));
6813 Make_Attribute_Reference
(Loc
,
6814 Prefix
=> Duplicate_Subexpr
(Exp
),
6815 Attribute_Name
=> Name_Tag
);
6818 -- CodePeer does not do anything useful with
6819 -- Ada.Tags.Type_Specific_Data components.
6821 if not CodePeer_Mode
then
6823 Make_Raise_Program_Error
(Loc
,
6826 Left_Opnd
=> Build_Get_Access_Level
(Loc
, Tag_Node
),
6828 Make_Integer_Literal
(Loc
,
6829 Scope_Depth
(Enclosing_Dynamic_Scope
(Scope_Id
)))),
6830 Reason
=> PE_Accessibility_Check_Failed
));
6834 -- AI05-0073: If function has a controlling access result, check that
6835 -- the tag of the return value, if it is not null, matches designated
6836 -- type of return type.
6838 -- The return expression is referenced twice in the code below, so it
6839 -- must be made free of side effects. Given that different compilers
6840 -- may evaluate these parameters in different order, both occurrences
6843 elsif Ekind
(R_Type
) = E_Anonymous_Access_Type
6844 and then Has_Controlling_Result
(Scope_Id
)
6847 Make_Raise_Constraint_Error
(Loc
,
6852 Left_Opnd
=> Duplicate_Subexpr
(Exp
),
6853 Right_Opnd
=> Make_Null
(Loc
)),
6855 Right_Opnd
=> Make_Op_Ne
(Loc
,
6857 Make_Selected_Component
(Loc
,
6858 Prefix
=> Duplicate_Subexpr
(Exp
),
6859 Selector_Name
=> Make_Identifier
(Loc
, Name_uTag
)),
6862 Make_Attribute_Reference
(Loc
,
6864 New_Occurrence_Of
(Designated_Type
(R_Type
), Loc
),
6865 Attribute_Name
=> Name_Tag
))),
6867 Reason
=> CE_Tag_Check_Failed
),
6868 Suppress
=> All_Checks
);
6871 -- AI05-0234: RM 6.5(21/3). Check access discriminants to
6872 -- ensure that the function result does not outlive an
6873 -- object designated by one of it discriminants.
6875 if Present
(Extra_Accessibility_Of_Result
(Scope_Id
))
6876 and then Has_Unconstrained_Access_Discriminants
(R_Type
)
6879 Discrim_Source
: Node_Id
;
6881 procedure Check_Against_Result_Level
(Level
: Node_Id
);
6882 -- Check the given accessibility level against the level
6883 -- determined by the point of call. (AI05-0234).
6885 --------------------------------
6886 -- Check_Against_Result_Level --
6887 --------------------------------
6889 procedure Check_Against_Result_Level
(Level
: Node_Id
) is
6892 Make_Raise_Program_Error
(Loc
,
6898 (Extra_Accessibility_Of_Result
(Scope_Id
), Loc
)),
6899 Reason
=> PE_Accessibility_Check_Failed
));
6900 end Check_Against_Result_Level
;
6903 Discrim_Source
:= Exp
;
6904 while Nkind
(Discrim_Source
) = N_Qualified_Expression
loop
6905 Discrim_Source
:= Expression
(Discrim_Source
);
6908 if Nkind
(Discrim_Source
) = N_Identifier
6909 and then Is_Return_Object
(Entity
(Discrim_Source
))
6911 Discrim_Source
:= Entity
(Discrim_Source
);
6913 if Is_Constrained
(Etype
(Discrim_Source
)) then
6914 Discrim_Source
:= Etype
(Discrim_Source
);
6916 Discrim_Source
:= Expression
(Parent
(Discrim_Source
));
6919 elsif Nkind
(Discrim_Source
) = N_Identifier
6920 and then Nkind_In
(Original_Node
(Discrim_Source
),
6921 N_Aggregate
, N_Extension_Aggregate
)
6923 Discrim_Source
:= Original_Node
(Discrim_Source
);
6925 elsif Nkind
(Discrim_Source
) = N_Explicit_Dereference
and then
6926 Nkind
(Original_Node
(Discrim_Source
)) = N_Function_Call
6928 Discrim_Source
:= Original_Node
(Discrim_Source
);
6931 Discrim_Source
:= Unqual_Conv
(Discrim_Source
);
6933 case Nkind
(Discrim_Source
) is
6934 when N_Defining_Identifier
=>
6935 pragma Assert
(Is_Composite_Type
(Discrim_Source
)
6936 and then Has_Discriminants
(Discrim_Source
)
6937 and then Is_Constrained
(Discrim_Source
));
6940 Discrim
: Entity_Id
:=
6941 First_Discriminant
(Base_Type
(R_Type
));
6942 Disc_Elmt
: Elmt_Id
:=
6943 First_Elmt
(Discriminant_Constraint
6947 if Ekind
(Etype
(Discrim
)) =
6948 E_Anonymous_Access_Type
6950 Check_Against_Result_Level
6951 (Dynamic_Accessibility_Level
(Node
(Disc_Elmt
)));
6954 Next_Elmt
(Disc_Elmt
);
6955 Next_Discriminant
(Discrim
);
6956 exit when not Present
(Discrim
);
6961 | N_Extension_Aggregate
6963 -- Unimplemented: extension aggregate case where discrims
6964 -- come from ancestor part, not extension part.
6967 Discrim
: Entity_Id
:=
6968 First_Discriminant
(Base_Type
(R_Type
));
6970 Disc_Exp
: Node_Id
:= Empty
;
6972 Positionals_Exhausted
6973 : Boolean := not Present
(Expressions
6976 function Associated_Expr
6977 (Comp_Id
: Entity_Id
;
6978 Associations
: List_Id
) return Node_Id
;
6980 -- Given a component and a component associations list,
6981 -- locate the expression for that component; returns
6982 -- Empty if no such expression is found.
6984 ---------------------
6985 -- Associated_Expr --
6986 ---------------------
6988 function Associated_Expr
6989 (Comp_Id
: Entity_Id
;
6990 Associations
: List_Id
) return Node_Id
6996 -- Simple linear search seems ok here
6998 Assoc
:= First
(Associations
);
6999 while Present
(Assoc
) loop
7000 Choice
:= First
(Choices
(Assoc
));
7001 while Present
(Choice
) loop
7002 if (Nkind
(Choice
) = N_Identifier
7003 and then Chars
(Choice
) = Chars
(Comp_Id
))
7004 or else (Nkind
(Choice
) = N_Others_Choice
)
7006 return Expression
(Assoc
);
7016 end Associated_Expr
;
7018 -- Start of processing for Expand_Simple_Function_Return
7021 if not Positionals_Exhausted
then
7022 Disc_Exp
:= First
(Expressions
(Discrim_Source
));
7026 if Positionals_Exhausted
then
7030 Component_Associations
(Discrim_Source
));
7033 if Ekind
(Etype
(Discrim
)) =
7034 E_Anonymous_Access_Type
7036 Check_Against_Result_Level
7037 (Dynamic_Accessibility_Level
(Disc_Exp
));
7040 Next_Discriminant
(Discrim
);
7041 exit when not Present
(Discrim
);
7043 if not Positionals_Exhausted
then
7045 Positionals_Exhausted
:= not Present
(Disc_Exp
);
7050 when N_Function_Call
=>
7052 -- No check needed (check performed by callee)
7058 Level
: constant Node_Id
:=
7059 Make_Integer_Literal
(Loc
,
7060 Object_Access_Level
(Discrim_Source
));
7063 -- Unimplemented: check for name prefix that includes
7064 -- a dereference of an access value with a dynamic
7065 -- accessibility level (e.g., an access param or a
7066 -- saooaaat) and use dynamic level in that case. For
7068 -- return Access_Param.all(Some_Index).Some_Component;
7071 Set_Etype
(Level
, Standard_Natural
);
7072 Check_Against_Result_Level
(Level
);
7078 -- If we are returning an object that may not be bit-aligned, then copy
7079 -- the value into a temporary first. This copy may need to expand to a
7080 -- loop of component operations.
7082 if Is_Possibly_Unaligned_Slice
(Exp
)
7083 or else Is_Possibly_Unaligned_Object
(Exp
)
7086 ExpR
: constant Node_Id
:= Relocate_Node
(Exp
);
7087 Tnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T', ExpR
);
7090 Make_Object_Declaration
(Loc
,
7091 Defining_Identifier
=> Tnn
,
7092 Constant_Present
=> True,
7093 Object_Definition
=> New_Occurrence_Of
(R_Type
, Loc
),
7094 Expression
=> ExpR
),
7095 Suppress
=> All_Checks
);
7096 Rewrite
(Exp
, New_Occurrence_Of
(Tnn
, Loc
));
7100 -- Call the _Postconditions procedure if the related function has
7101 -- contract assertions that need to be verified on exit.
7103 if Ekind
(Scope_Id
) = E_Function
7104 and then Present
(Postconditions_Proc
(Scope_Id
))
7106 -- In the case of discriminated objects, we have created a
7107 -- constrained subtype above, and used the underlying type. This
7108 -- transformation is post-analysis and harmless, except that now the
7109 -- call to the post-condition will be analyzed and the type kinds
7112 if Nkind
(Exp
) = N_Unchecked_Type_Conversion
7113 and then Is_Private_Type
(R_Type
) /= Is_Private_Type
(Etype
(Exp
))
7115 Rewrite
(Exp
, Expression
(Relocate_Node
(Exp
)));
7118 -- We are going to reference the returned value twice in this case,
7119 -- once in the call to _Postconditions, and once in the actual return
7120 -- statement, but we can't have side effects happening twice.
7122 Force_Evaluation
(Exp
, Mode
=> Strict
);
7124 -- Generate call to _Postconditions
7127 Make_Procedure_Call_Statement
(Loc
,
7129 New_Occurrence_Of
(Postconditions_Proc
(Scope_Id
), Loc
),
7130 Parameter_Associations
=> New_List
(New_Copy_Tree
(Exp
))));
7133 -- Ada 2005 (AI-251): If this return statement corresponds with an
7134 -- simple return statement associated with an extended return statement
7135 -- and the type of the returned object is an interface then generate an
7136 -- implicit conversion to force displacement of the "this" pointer.
7138 if Ada_Version
>= Ada_2005
7139 and then Comes_From_Extended_Return_Statement
(N
)
7140 and then Nkind
(Expression
(N
)) = N_Identifier
7141 and then Is_Interface
(Utyp
)
7142 and then Utyp
/= Underlying_Type
(Exptyp
)
7144 Rewrite
(Exp
, Convert_To
(Utyp
, Relocate_Node
(Exp
)));
7145 Analyze_And_Resolve
(Exp
);
7147 end Expand_Simple_Function_Return
;
7149 --------------------------------------------
7150 -- Has_Unconstrained_Access_Discriminants --
7151 --------------------------------------------
7153 function Has_Unconstrained_Access_Discriminants
7154 (Subtyp
: Entity_Id
) return Boolean
7159 if Has_Discriminants
(Subtyp
)
7160 and then not Is_Constrained
(Subtyp
)
7162 Discr
:= First_Discriminant
(Subtyp
);
7163 while Present
(Discr
) loop
7164 if Ekind
(Etype
(Discr
)) = E_Anonymous_Access_Type
then
7168 Next_Discriminant
(Discr
);
7173 end Has_Unconstrained_Access_Discriminants
;
7175 --------------------------------
7176 -- Is_Build_In_Place_Function --
7177 --------------------------------
7179 function Is_Build_In_Place_Function
(E
: Entity_Id
) return Boolean is
7181 -- This function is called from Expand_Subtype_From_Expr during
7182 -- semantic analysis, even when expansion is off. In those cases
7183 -- the build_in_place expansion will not take place.
7185 if not Expander_Active
then
7189 -- For now we test whether E denotes a function or access-to-function
7190 -- type whose result subtype is inherently limited. Later this test
7191 -- may be revised to allow composite nonlimited types. Functions with
7192 -- a foreign convention or whose result type has a foreign convention
7195 if Ekind_In
(E
, E_Function
, E_Generic_Function
)
7196 or else (Ekind
(E
) = E_Subprogram_Type
7197 and then Etype
(E
) /= Standard_Void_Type
)
7199 -- Note: If the function has a foreign convention, it cannot build
7200 -- its result in place, so you're on your own. On the other hand,
7201 -- if only the return type has a foreign convention, its layout is
7202 -- intended to be compatible with the other language, but the build-
7203 -- in place machinery can ensure that the object is not copied.
7205 if Has_Foreign_Convention
(E
) then
7208 -- In Ada 2005 all functions with an inherently limited return type
7209 -- must be handled using a build-in-place profile, including the case
7210 -- of a function with a limited interface result, where the function
7211 -- may return objects of nonlimited descendants.
7214 return Is_Limited_View
(Etype
(E
))
7215 and then Ada_Version
>= Ada_2005
7216 and then not Debug_Flag_Dot_L
;
7222 end Is_Build_In_Place_Function
;
7224 -------------------------------------
7225 -- Is_Build_In_Place_Function_Call --
7226 -------------------------------------
7228 function Is_Build_In_Place_Function_Call
(N
: Node_Id
) return Boolean is
7229 Exp_Node
: constant Node_Id
:= Unqual_Conv
(N
);
7230 Function_Id
: Entity_Id
;
7233 -- Return False if the expander is currently inactive, since awareness
7234 -- of build-in-place treatment is only relevant during expansion. Note
7235 -- that Is_Build_In_Place_Function, which is called as part of this
7236 -- function, is also conditioned this way, but we need to check here as
7237 -- well to avoid blowing up on processing protected calls when expansion
7238 -- is disabled (such as with -gnatc) since those would trip over the
7239 -- raise of Program_Error below.
7241 -- In SPARK mode, build-in-place calls are not expanded, so that we
7242 -- may end up with a call that is neither resolved to an entity, nor
7243 -- an indirect call.
7245 if not Expander_Active
then
7249 if Nkind
(Exp_Node
) /= N_Function_Call
then
7253 if Is_Entity_Name
(Name
(Exp_Node
)) then
7254 Function_Id
:= Entity
(Name
(Exp_Node
));
7256 -- In the case of an explicitly dereferenced call, use the subprogram
7257 -- type generated for the dereference.
7259 elsif Nkind
(Name
(Exp_Node
)) = N_Explicit_Dereference
then
7260 Function_Id
:= Etype
(Name
(Exp_Node
));
7262 -- This may be a call to a protected function.
7264 elsif Nkind
(Name
(Exp_Node
)) = N_Selected_Component
then
7265 Function_Id
:= Etype
(Entity
(Selector_Name
(Name
(Exp_Node
))));
7268 raise Program_Error
;
7271 return Is_Build_In_Place_Function
(Function_Id
);
7273 end Is_Build_In_Place_Function_Call
;
7275 -----------------------
7276 -- Freeze_Subprogram --
7277 -----------------------
7279 procedure Freeze_Subprogram
(N
: Node_Id
) is
7280 Loc
: constant Source_Ptr
:= Sloc
(N
);
7282 procedure Register_Predefined_DT_Entry
(Prim
: Entity_Id
);
7283 -- (Ada 2005): Register a predefined primitive in all the secondary
7284 -- dispatch tables of its primitive type.
7286 ----------------------------------
7287 -- Register_Predefined_DT_Entry --
7288 ----------------------------------
7290 procedure Register_Predefined_DT_Entry
(Prim
: Entity_Id
) is
7291 Iface_DT_Ptr
: Elmt_Id
;
7292 Tagged_Typ
: Entity_Id
;
7293 Thunk_Id
: Entity_Id
;
7294 Thunk_Code
: Node_Id
;
7297 Tagged_Typ
:= Find_Dispatching_Type
(Prim
);
7299 if No
(Access_Disp_Table
(Tagged_Typ
))
7300 or else not Has_Interfaces
(Tagged_Typ
)
7301 or else not RTE_Available
(RE_Interface_Tag
)
7302 or else Restriction_Active
(No_Dispatching_Calls
)
7307 -- Skip the first two access-to-dispatch-table pointers since they
7308 -- leads to the primary dispatch table (predefined DT and user
7309 -- defined DT). We are only concerned with the secondary dispatch
7310 -- table pointers. Note that the access-to- dispatch-table pointer
7311 -- corresponds to the first implemented interface retrieved below.
7314 Next_Elmt
(Next_Elmt
(First_Elmt
(Access_Disp_Table
(Tagged_Typ
))));
7316 while Present
(Iface_DT_Ptr
)
7317 and then Ekind
(Node
(Iface_DT_Ptr
)) = E_Constant
7319 pragma Assert
(Has_Thunks
(Node
(Iface_DT_Ptr
)));
7320 Expand_Interface_Thunk
(Prim
, Thunk_Id
, Thunk_Code
);
7322 if Present
(Thunk_Code
) then
7323 Insert_Actions_After
(N
, New_List
(
7326 Build_Set_Predefined_Prim_Op_Address
(Loc
,
7328 New_Occurrence_Of
(Node
(Next_Elmt
(Iface_DT_Ptr
)), Loc
),
7329 Position
=> DT_Position
(Prim
),
7331 Unchecked_Convert_To
(RTE
(RE_Prim_Ptr
),
7332 Make_Attribute_Reference
(Loc
,
7333 Prefix
=> New_Occurrence_Of
(Thunk_Id
, Loc
),
7334 Attribute_Name
=> Name_Unrestricted_Access
))),
7336 Build_Set_Predefined_Prim_Op_Address
(Loc
,
7339 (Node
(Next_Elmt
(Next_Elmt
(Next_Elmt
(Iface_DT_Ptr
)))),
7341 Position
=> DT_Position
(Prim
),
7343 Unchecked_Convert_To
(RTE
(RE_Prim_Ptr
),
7344 Make_Attribute_Reference
(Loc
,
7345 Prefix
=> New_Occurrence_Of
(Prim
, Loc
),
7346 Attribute_Name
=> Name_Unrestricted_Access
)))));
7349 -- Skip the tag of the predefined primitives dispatch table
7351 Next_Elmt
(Iface_DT_Ptr
);
7352 pragma Assert
(Has_Thunks
(Node
(Iface_DT_Ptr
)));
7354 -- Skip tag of the no-thunks dispatch table
7356 Next_Elmt
(Iface_DT_Ptr
);
7357 pragma Assert
(not Has_Thunks
(Node
(Iface_DT_Ptr
)));
7359 -- Skip tag of predefined primitives no-thunks dispatch table
7361 Next_Elmt
(Iface_DT_Ptr
);
7362 pragma Assert
(not Has_Thunks
(Node
(Iface_DT_Ptr
)));
7364 Next_Elmt
(Iface_DT_Ptr
);
7366 end Register_Predefined_DT_Entry
;
7370 Subp
: constant Entity_Id
:= Entity
(N
);
7372 -- Start of processing for Freeze_Subprogram
7375 -- We suppress the initialization of the dispatch table entry when
7376 -- not Tagged_Type_Expansion because the dispatching mechanism is
7377 -- handled internally by the target.
7379 if Is_Dispatching_Operation
(Subp
)
7380 and then not Is_Abstract_Subprogram
(Subp
)
7381 and then Present
(DTC_Entity
(Subp
))
7382 and then Present
(Scope
(DTC_Entity
(Subp
)))
7383 and then Tagged_Type_Expansion
7384 and then not Restriction_Active
(No_Dispatching_Calls
)
7385 and then RTE_Available
(RE_Tag
)
7388 Typ
: constant Entity_Id
:= Scope
(DTC_Entity
(Subp
));
7391 -- Handle private overridden primitives
7393 if not Is_CPP_Class
(Typ
) then
7394 Check_Overriding_Operation
(Subp
);
7397 -- We assume that imported CPP primitives correspond with objects
7398 -- whose constructor is in the CPP side; therefore we don't need
7399 -- to generate code to register them in the dispatch table.
7401 if Is_CPP_Class
(Typ
) then
7404 -- Handle CPP primitives found in derivations of CPP_Class types.
7405 -- These primitives must have been inherited from some parent, and
7406 -- there is no need to register them in the dispatch table because
7407 -- Build_Inherit_Prims takes care of initializing these slots.
7409 elsif Is_Imported
(Subp
)
7410 and then (Convention
(Subp
) = Convention_CPP
7411 or else Convention
(Subp
) = Convention_C
)
7415 -- Generate code to register the primitive in non statically
7416 -- allocated dispatch tables
7418 elsif not Building_Static_DT
(Scope
(DTC_Entity
(Subp
))) then
7420 -- When a primitive is frozen, enter its name in its dispatch
7423 if not Is_Interface
(Typ
)
7424 or else Present
(Interface_Alias
(Subp
))
7426 if Is_Predefined_Dispatching_Operation
(Subp
) then
7427 Register_Predefined_DT_Entry
(Subp
);
7430 Insert_Actions_After
(N
,
7431 Register_Primitive
(Loc
, Prim
=> Subp
));
7437 -- Mark functions that return by reference. Note that it cannot be part
7438 -- of the normal semantic analysis of the spec since the underlying
7439 -- returned type may not be known yet (for private types).
7442 Typ
: constant Entity_Id
:= Etype
(Subp
);
7443 Utyp
: constant Entity_Id
:= Underlying_Type
(Typ
);
7446 if Is_Limited_View
(Typ
) then
7447 Set_Returns_By_Ref
(Subp
);
7449 elsif Present
(Utyp
) and then CW_Or_Has_Controlled_Part
(Utyp
) then
7450 Set_Returns_By_Ref
(Subp
);
7454 -- Wnen freezing a null procedure, analyze its delayed aspects now
7455 -- because we may not have reached the end of the declarative list when
7456 -- delayed aspects are normally analyzed. This ensures that dispatching
7457 -- calls are properly rewritten when the generated _Postcondition
7458 -- procedure is analyzed in the null procedure body.
7460 if Nkind
(Parent
(Subp
)) = N_Procedure_Specification
7461 and then Null_Present
(Parent
(Subp
))
7463 Analyze_Entry_Or_Subprogram_Contract
(Subp
);
7465 end Freeze_Subprogram
;
7467 ------------------------------
7468 -- Insert_Post_Call_Actions --
7469 ------------------------------
7471 procedure Insert_Post_Call_Actions
(N
: Node_Id
; Post_Call
: List_Id
) is
7472 Context
: constant Node_Id
:= Parent
(N
);
7475 if Is_Empty_List
(Post_Call
) then
7479 -- Cases where the call is not a member of a statement list. This
7480 -- includes the case where the call is an actual in another function
7481 -- call or indexing, i.e. an expression context as well.
7483 if not Is_List_Member
(N
)
7484 or else Nkind_In
(Context
, N_Function_Call
, N_Indexed_Component
)
7486 -- In Ada 2012 the call may be a function call in an expression
7487 -- (since OUT and IN OUT parameters are now allowed for such calls).
7488 -- The write-back of (in)-out parameters is handled by the back-end,
7489 -- but the constraint checks generated when subtypes of formal and
7490 -- actual don't match must be inserted in the form of assignments.
7492 if Nkind
(Original_Node
(N
)) = N_Function_Call
then
7493 pragma Assert
(Ada_Version
>= Ada_2012
);
7494 -- Functions with '[in] out' parameters are only allowed in Ada
7497 -- We used to handle this by climbing up parents to a
7498 -- non-statement/declaration and then simply making a call to
7499 -- Insert_Actions_After (P, Post_Call), but that doesn't work
7500 -- for Ada 2012. If we are in the middle of an expression, e.g.
7501 -- the condition of an IF, this call would insert after the IF
7502 -- statement, which is much too late to be doing the write back.
7505 -- if Clobber (X) then
7506 -- Put_Line (X'Img);
7511 -- Now assume Clobber changes X, if we put the write back after
7512 -- the IF, the Put_Line gets the wrong value and the goto causes
7513 -- the write back to be skipped completely.
7515 -- To deal with this, we replace the call by
7518 -- Tnnn : constant function-result-type := function-call;
7519 -- Post_Call actions
7525 Loc
: constant Source_Ptr
:= Sloc
(N
);
7526 Tnnn
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
7527 FRTyp
: constant Entity_Id
:= Etype
(N
);
7528 Name
: constant Node_Id
:= Relocate_Node
(N
);
7531 Prepend_To
(Post_Call
,
7532 Make_Object_Declaration
(Loc
,
7533 Defining_Identifier
=> Tnnn
,
7534 Object_Definition
=> New_Occurrence_Of
(FRTyp
, Loc
),
7535 Constant_Present
=> True,
7536 Expression
=> Name
));
7539 Make_Expression_With_Actions
(Loc
,
7540 Actions
=> Post_Call
,
7541 Expression
=> New_Occurrence_Of
(Tnnn
, Loc
)));
7543 -- We don't want to just blindly call Analyze_And_Resolve
7544 -- because that would cause unwanted recursion on the call.
7545 -- So for a moment set the call as analyzed to prevent that
7546 -- recursion, and get the rest analyzed properly, then reset
7547 -- the analyzed flag, so our caller can continue.
7549 Set_Analyzed
(Name
, True);
7550 Analyze_And_Resolve
(N
, FRTyp
);
7551 Set_Analyzed
(Name
, False);
7554 -- If not the special Ada 2012 case of a function call, then we must
7555 -- have the triggering statement of a triggering alternative or an
7556 -- entry call alternative, and we can add the post call stuff to the
7557 -- corresponding statement list.
7560 pragma Assert
(Nkind_In
(Context
, N_Entry_Call_Alternative
,
7561 N_Triggering_Alternative
));
7563 if Is_Non_Empty_List
(Statements
(Context
)) then
7564 Insert_List_Before_And_Analyze
7565 (First
(Statements
(Context
)), Post_Call
);
7567 Set_Statements
(Context
, Post_Call
);
7571 -- A procedure call is always part of a declarative or statement list,
7572 -- however a function call may appear nested within a construct. Most
7573 -- cases of function call nesting are handled in the special case above.
7574 -- The only exception is when the function call acts as an actual in a
7575 -- procedure call. In this case the function call is in a list, but the
7576 -- post-call actions must be inserted after the procedure call.
7578 elsif Nkind
(Context
) = N_Procedure_Call_Statement
then
7579 Insert_Actions_After
(Context
, Post_Call
);
7581 -- Otherwise, normal case where N is in a statement sequence, just put
7582 -- the post-call stuff after the call statement.
7585 Insert_Actions_After
(N
, Post_Call
);
7587 end Insert_Post_Call_Actions
;
7589 -----------------------
7590 -- Is_Null_Procedure --
7591 -----------------------
7593 function Is_Null_Procedure
(Subp
: Entity_Id
) return Boolean is
7594 Decl
: constant Node_Id
:= Unit_Declaration_Node
(Subp
);
7597 if Ekind
(Subp
) /= E_Procedure
then
7600 -- Check if this is a declared null procedure
7602 elsif Nkind
(Decl
) = N_Subprogram_Declaration
then
7603 if not Null_Present
(Specification
(Decl
)) then
7606 elsif No
(Body_To_Inline
(Decl
)) then
7609 -- Check if the body contains only a null statement, followed by
7610 -- the return statement added during expansion.
7614 Orig_Bod
: constant Node_Id
:= Body_To_Inline
(Decl
);
7620 if Nkind
(Orig_Bod
) /= N_Subprogram_Body
then
7623 -- We must skip SCIL nodes because they are currently
7624 -- implemented as special N_Null_Statement nodes.
7628 (Statements
(Handled_Statement_Sequence
(Orig_Bod
)));
7629 Stat2
:= Next_Non_SCIL_Node
(Stat
);
7632 Is_Empty_List
(Declarations
(Orig_Bod
))
7633 and then Nkind
(Stat
) = N_Null_Statement
7637 (Nkind
(Stat2
) = N_Simple_Return_Statement
7638 and then No
(Next
(Stat2
))));
7646 end Is_Null_Procedure
;
7648 -------------------------------------------
7649 -- Make_Build_In_Place_Call_In_Allocator --
7650 -------------------------------------------
7652 procedure Make_Build_In_Place_Call_In_Allocator
7653 (Allocator
: Node_Id
;
7654 Function_Call
: Node_Id
)
7656 Acc_Type
: constant Entity_Id
:= Etype
(Allocator
);
7658 Func_Call
: Node_Id
:= Function_Call
;
7659 Ref_Func_Call
: Node_Id
;
7660 Function_Id
: Entity_Id
;
7661 Result_Subt
: Entity_Id
;
7662 New_Allocator
: Node_Id
;
7663 Return_Obj_Access
: Entity_Id
; -- temp for function result
7664 Temp_Init
: Node_Id
; -- initial value of Return_Obj_Access
7665 Alloc_Form
: BIP_Allocation_Form
;
7666 Pool
: Node_Id
; -- nonnull if Alloc_Form = User_Storage_Pool
7667 Return_Obj_Actual
: Node_Id
; -- the temp.all, in caller-allocates case
7668 Chain
: Entity_Id
; -- activation chain, in case of tasks
7671 -- Step past qualification or unchecked conversion (the latter can occur
7672 -- in cases of calls to 'Input).
7674 if Nkind_In
(Func_Call
,
7675 N_Qualified_Expression
,
7677 N_Unchecked_Type_Conversion
)
7679 Func_Call
:= Expression
(Func_Call
);
7682 -- If the call has already been processed to add build-in-place actuals
7683 -- then return. This should not normally occur in an allocator context,
7684 -- but we add the protection as a defensive measure.
7686 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
7690 -- Mark the call as processed as a build-in-place call
7692 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
7694 Loc
:= Sloc
(Function_Call
);
7696 if Is_Entity_Name
(Name
(Func_Call
)) then
7697 Function_Id
:= Entity
(Name
(Func_Call
));
7699 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
7700 Function_Id
:= Etype
(Name
(Func_Call
));
7703 raise Program_Error
;
7706 Result_Subt
:= Available_View
(Etype
(Function_Id
));
7708 -- Create a temp for the function result. In the caller-allocates case,
7709 -- this will be initialized to the result of a new uninitialized
7710 -- allocator. Note: we do not use Allocator as the Related_Node of
7711 -- Return_Obj_Access in call to Make_Temporary below as this would
7712 -- create a sort of infinite "recursion".
7714 Return_Obj_Access
:= Make_Temporary
(Loc
, 'R');
7715 Set_Etype
(Return_Obj_Access
, Acc_Type
);
7717 -- When the result subtype is constrained, the return object is
7718 -- allocated on the caller side, and access to it is passed to the
7721 -- Here and in related routines, we must examine the full view of the
7722 -- type, because the view at the point of call may differ from that
7723 -- that in the function body, and the expansion mechanism depends on
7724 -- the characteristics of the full view.
7726 if Is_Constrained
(Underlying_Type
(Result_Subt
)) then
7728 -- Replace the initialized allocator of form "new T'(Func (...))"
7729 -- with an uninitialized allocator of form "new T", where T is the
7730 -- result subtype of the called function. The call to the function
7731 -- is handled separately further below.
7734 Make_Allocator
(Loc
,
7735 Expression
=> New_Occurrence_Of
(Result_Subt
, Loc
));
7736 Set_No_Initialization
(New_Allocator
);
7738 -- Copy attributes to new allocator. Note that the new allocator
7739 -- logically comes from source if the original one did, so copy the
7740 -- relevant flag. This ensures proper treatment of the restriction
7741 -- No_Implicit_Heap_Allocations in this case.
7743 Set_Storage_Pool
(New_Allocator
, Storage_Pool
(Allocator
));
7744 Set_Procedure_To_Call
(New_Allocator
, Procedure_To_Call
(Allocator
));
7745 Set_Comes_From_Source
(New_Allocator
, Comes_From_Source
(Allocator
));
7747 Rewrite
(Allocator
, New_Allocator
);
7749 -- Initial value of the temp is the result of the uninitialized
7752 Temp_Init
:= Relocate_Node
(Allocator
);
7754 -- Indicate that caller allocates, and pass in the return object
7756 Alloc_Form
:= Caller_Allocation
;
7757 Pool
:= Make_Null
(No_Location
);
7758 Return_Obj_Actual
:=
7759 Make_Unchecked_Type_Conversion
(Loc
,
7760 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
7762 Make_Explicit_Dereference
(Loc
,
7763 Prefix
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
)));
7765 -- When the result subtype is unconstrained, the function itself must
7766 -- perform the allocation of the return object, so we pass parameters
7772 -- Case of a user-defined storage pool. Pass an allocation parameter
7773 -- indicating that the function should allocate its result in the
7774 -- pool, and pass the pool. Use 'Unrestricted_Access because the
7775 -- pool may not be aliased.
7777 if Present
(Associated_Storage_Pool
(Acc_Type
)) then
7778 Alloc_Form
:= User_Storage_Pool
;
7780 Make_Attribute_Reference
(Loc
,
7783 (Associated_Storage_Pool
(Acc_Type
), Loc
),
7784 Attribute_Name
=> Name_Unrestricted_Access
);
7786 -- No user-defined pool; pass an allocation parameter indicating that
7787 -- the function should allocate its result on the heap.
7790 Alloc_Form
:= Global_Heap
;
7791 Pool
:= Make_Null
(No_Location
);
7794 -- The caller does not provide the return object in this case, so we
7795 -- have to pass null for the object access actual.
7797 Return_Obj_Actual
:= Empty
;
7800 -- Declare the temp object
7802 Insert_Action
(Allocator
,
7803 Make_Object_Declaration
(Loc
,
7804 Defining_Identifier
=> Return_Obj_Access
,
7805 Object_Definition
=> New_Occurrence_Of
(Acc_Type
, Loc
),
7806 Expression
=> Temp_Init
));
7808 Ref_Func_Call
:= Make_Reference
(Loc
, Func_Call
);
7810 -- Ada 2005 (AI-251): If the type of the allocator is an interface
7811 -- then generate an implicit conversion to force displacement of the
7814 if Is_Interface
(Designated_Type
(Acc_Type
)) then
7817 OK_Convert_To
(Acc_Type
, Ref_Func_Call
));
7821 Assign
: constant Node_Id
:=
7822 Make_Assignment_Statement
(Loc
,
7823 Name
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
),
7824 Expression
=> Ref_Func_Call
);
7825 -- Assign the result of the function call into the temp. In the
7826 -- caller-allocates case, this is overwriting the temp with its
7827 -- initial value, which has no effect. In the callee-allocates case,
7828 -- this is setting the temp to point to the object allocated by the
7832 -- Actions to be inserted. If there are no tasks, this is just the
7833 -- assignment statement. If the allocated object has tasks, we need
7834 -- to wrap the assignment in a block that activates them. The
7835 -- activation chain of that block must be passed to the function,
7836 -- rather than some outer chain.
7838 if Has_Task
(Result_Subt
) then
7839 Actions
:= New_List
;
7840 Build_Task_Allocate_Block_With_Init_Stmts
7841 (Actions
, Allocator
, Init_Stmts
=> New_List
(Assign
));
7842 Chain
:= Activation_Chain_Entity
(Last
(Actions
));
7844 Actions
:= New_List
(Assign
);
7848 Insert_Actions
(Allocator
, Actions
);
7851 -- When the function has a controlling result, an allocation-form
7852 -- parameter must be passed indicating that the caller is allocating
7853 -- the result object. This is needed because such a function can be
7854 -- called as a dispatching operation and must be treated similarly
7855 -- to functions with unconstrained result subtypes.
7857 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7858 (Func_Call
, Function_Id
, Alloc_Form
, Pool_Actual
=> Pool
);
7860 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7861 (Func_Call
, Function_Id
, Acc_Type
);
7863 Add_Task_Actuals_To_Build_In_Place_Call
7864 (Func_Call
, Function_Id
, Master_Actual
=> Master_Id
(Acc_Type
),
7867 -- Add an implicit actual to the function call that provides access
7868 -- to the allocated object. An unchecked conversion to the (specific)
7869 -- result subtype of the function is inserted to handle cases where
7870 -- the access type of the allocator has a class-wide designated type.
7872 Add_Access_Actual_To_Build_In_Place_Call
7873 (Func_Call
, Function_Id
, Return_Obj_Actual
);
7875 -- Finally, replace the allocator node with a reference to the temp
7877 Rewrite
(Allocator
, New_Occurrence_Of
(Return_Obj_Access
, Loc
));
7879 Analyze_And_Resolve
(Allocator
, Acc_Type
);
7880 end Make_Build_In_Place_Call_In_Allocator
;
7882 ---------------------------------------------------
7883 -- Make_Build_In_Place_Call_In_Anonymous_Context --
7884 ---------------------------------------------------
7886 procedure Make_Build_In_Place_Call_In_Anonymous_Context
7887 (Function_Call
: Node_Id
)
7890 Func_Call
: constant Node_Id
:= Unqual_Conv
(Function_Call
);
7891 Function_Id
: Entity_Id
;
7892 Result_Subt
: Entity_Id
;
7893 Return_Obj_Id
: Entity_Id
;
7894 Return_Obj_Decl
: Entity_Id
;
7897 -- If the call has already been processed to add build-in-place actuals
7898 -- then return. One place this can occur is for calls to build-in-place
7899 -- functions that occur within a call to a protected operation, where
7900 -- due to rewriting and expansion of the protected call there can be
7901 -- more than one call to Expand_Actuals for the same set of actuals.
7903 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
7907 -- Mark the call as processed as a build-in-place call
7909 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
7911 Loc
:= Sloc
(Function_Call
);
7913 if Is_Entity_Name
(Name
(Func_Call
)) then
7914 Function_Id
:= Entity
(Name
(Func_Call
));
7916 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
7917 Function_Id
:= Etype
(Name
(Func_Call
));
7920 raise Program_Error
;
7923 Result_Subt
:= Etype
(Function_Id
);
7925 -- If the build-in-place function returns a controlled object, then the
7926 -- object needs to be finalized immediately after the context. Since
7927 -- this case produces a transient scope, the servicing finalizer needs
7928 -- to name the returned object. Create a temporary which is initialized
7929 -- with the function call:
7931 -- Temp_Id : Func_Type := BIP_Func_Call;
7933 -- The initialization expression of the temporary will be rewritten by
7934 -- the expander using the appropriate mechanism in Make_Build_In_Place_
7935 -- Call_In_Object_Declaration.
7937 if Needs_Finalization
(Result_Subt
) then
7939 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'R');
7940 Temp_Decl
: Node_Id
;
7943 -- Reset the guard on the function call since the following does
7944 -- not perform actual call expansion.
7946 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
, False);
7949 Make_Object_Declaration
(Loc
,
7950 Defining_Identifier
=> Temp_Id
,
7951 Object_Definition
=>
7952 New_Occurrence_Of
(Result_Subt
, Loc
),
7954 New_Copy_Tree
(Function_Call
));
7956 Insert_Action
(Function_Call
, Temp_Decl
);
7958 Rewrite
(Function_Call
, New_Occurrence_Of
(Temp_Id
, Loc
));
7959 Analyze
(Function_Call
);
7962 -- When the result subtype is definite, an object of the subtype is
7963 -- declared and an access value designating it is passed as an actual.
7965 elsif Caller_Known_Size
(Func_Call
, Result_Subt
) then
7967 -- Create a temporary object to hold the function result
7969 Return_Obj_Id
:= Make_Temporary
(Loc
, 'R');
7970 Set_Etype
(Return_Obj_Id
, Result_Subt
);
7973 Make_Object_Declaration
(Loc
,
7974 Defining_Identifier
=> Return_Obj_Id
,
7975 Aliased_Present
=> True,
7976 Object_Definition
=> New_Occurrence_Of
(Result_Subt
, Loc
));
7978 Set_No_Initialization
(Return_Obj_Decl
);
7980 Insert_Action
(Func_Call
, Return_Obj_Decl
);
7982 -- When the function has a controlling result, an allocation-form
7983 -- parameter must be passed indicating that the caller is allocating
7984 -- the result object. This is needed because such a function can be
7985 -- called as a dispatching operation and must be treated similarly
7986 -- to functions with unconstrained result subtypes.
7988 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7989 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
7991 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7992 (Func_Call
, Function_Id
);
7994 Add_Task_Actuals_To_Build_In_Place_Call
7995 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
7997 -- Add an implicit actual to the function call that provides access
7998 -- to the caller's return object.
8000 Add_Access_Actual_To_Build_In_Place_Call
8001 (Func_Call
, Function_Id
, New_Occurrence_Of
(Return_Obj_Id
, Loc
));
8003 -- When the result subtype is unconstrained, the function must allocate
8004 -- the return object in the secondary stack, so appropriate implicit
8005 -- parameters are added to the call to indicate that. A transient
8006 -- scope is established to ensure eventual cleanup of the result.
8009 -- Pass an allocation parameter indicating that the function should
8010 -- allocate its result on the secondary stack.
8012 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8013 (Func_Call
, Function_Id
, Alloc_Form
=> Secondary_Stack
);
8015 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8016 (Func_Call
, Function_Id
);
8018 Add_Task_Actuals_To_Build_In_Place_Call
8019 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8021 -- Pass a null value to the function since no return object is
8022 -- available on the caller side.
8024 Add_Access_Actual_To_Build_In_Place_Call
8025 (Func_Call
, Function_Id
, Empty
);
8027 end Make_Build_In_Place_Call_In_Anonymous_Context
;
8029 --------------------------------------------
8030 -- Make_Build_In_Place_Call_In_Assignment --
8031 --------------------------------------------
8033 procedure Make_Build_In_Place_Call_In_Assignment
8035 Function_Call
: Node_Id
)
8037 Lhs
: constant Node_Id
:= Name
(Assign
);
8038 Func_Call
: constant Node_Id
:= Unqual_Conv
(Function_Call
);
8039 Func_Id
: Entity_Id
;
8043 Ptr_Typ
: Entity_Id
;
8044 Ptr_Typ_Decl
: Node_Id
;
8046 Result_Subt
: Entity_Id
;
8049 -- If the call has already been processed to add build-in-place actuals
8050 -- then return. This should not normally occur in an assignment context,
8051 -- but we add the protection as a defensive measure.
8053 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
8057 -- Mark the call as processed as a build-in-place call
8059 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
8061 Loc
:= Sloc
(Function_Call
);
8063 if Is_Entity_Name
(Name
(Func_Call
)) then
8064 Func_Id
:= Entity
(Name
(Func_Call
));
8066 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
8067 Func_Id
:= Etype
(Name
(Func_Call
));
8070 raise Program_Error
;
8073 Result_Subt
:= Etype
(Func_Id
);
8075 -- When the result subtype is unconstrained, an additional actual must
8076 -- be passed to indicate that the caller is providing the return object.
8077 -- This parameter must also be passed when the called function has a
8078 -- controlling result, because dispatching calls to the function needs
8079 -- to be treated effectively the same as calls to class-wide functions.
8081 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8082 (Func_Call
, Func_Id
, Alloc_Form
=> Caller_Allocation
);
8084 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8085 (Func_Call
, Func_Id
);
8087 Add_Task_Actuals_To_Build_In_Place_Call
8088 (Func_Call
, Func_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8090 -- Add an implicit actual to the function call that provides access to
8091 -- the caller's return object.
8093 Add_Access_Actual_To_Build_In_Place_Call
8096 Make_Unchecked_Type_Conversion
(Loc
,
8097 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
8098 Expression
=> Relocate_Node
(Lhs
)));
8100 -- Create an access type designating the function's result subtype
8102 Ptr_Typ
:= Make_Temporary
(Loc
, 'A');
8105 Make_Full_Type_Declaration
(Loc
,
8106 Defining_Identifier
=> Ptr_Typ
,
8108 Make_Access_To_Object_Definition
(Loc
,
8109 All_Present
=> True,
8110 Subtype_Indication
=>
8111 New_Occurrence_Of
(Result_Subt
, Loc
)));
8112 Insert_After_And_Analyze
(Assign
, Ptr_Typ_Decl
);
8114 -- Finally, create an access object initialized to a reference to the
8115 -- function call. We know this access value is non-null, so mark the
8116 -- entity accordingly to suppress junk access checks.
8118 New_Expr
:= Make_Reference
(Loc
, Relocate_Node
(Func_Call
));
8120 Obj_Id
:= Make_Temporary
(Loc
, 'R', New_Expr
);
8121 Set_Etype
(Obj_Id
, Ptr_Typ
);
8122 Set_Is_Known_Non_Null
(Obj_Id
);
8125 Make_Object_Declaration
(Loc
,
8126 Defining_Identifier
=> Obj_Id
,
8127 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8128 Expression
=> New_Expr
);
8129 Insert_After_And_Analyze
(Ptr_Typ_Decl
, Obj_Decl
);
8131 Rewrite
(Assign
, Make_Null_Statement
(Loc
));
8132 end Make_Build_In_Place_Call_In_Assignment
;
8134 ----------------------------------------------------
8135 -- Make_Build_In_Place_Call_In_Object_Declaration --
8136 ----------------------------------------------------
8138 procedure Make_Build_In_Place_Call_In_Object_Declaration
8139 (Obj_Decl
: Node_Id
;
8140 Function_Call
: Node_Id
)
8142 Obj_Def_Id
: constant Entity_Id
:= Defining_Identifier
(Obj_Decl
);
8143 Encl_Func
: constant Entity_Id
:= Enclosing_Subprogram
(Obj_Def_Id
);
8144 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8145 Obj_Loc
: constant Source_Ptr
:= Sloc
(Obj_Decl
);
8147 Call_Deref
: Node_Id
;
8148 Caller_Object
: Node_Id
;
8150 Fmaster_Actual
: Node_Id
:= Empty
;
8151 Func_Call
: constant Node_Id
:= Unqual_Conv
(Function_Call
);
8152 Function_Id
: Entity_Id
;
8153 Pool_Actual
: Node_Id
;
8154 Ptr_Typ
: Entity_Id
;
8155 Ptr_Typ_Decl
: Node_Id
;
8156 Pass_Caller_Acc
: Boolean := False;
8158 Result_Subt
: Entity_Id
;
8161 -- If the call has already been processed to add build-in-place actuals
8162 -- then return. This should not normally occur in an object declaration,
8163 -- but we add the protection as a defensive measure.
8165 if Is_Expanded_Build_In_Place_Call
(Func_Call
) then
8169 -- Mark the call as processed as a build-in-place call
8171 Set_Is_Expanded_Build_In_Place_Call
(Func_Call
);
8173 if Is_Entity_Name
(Name
(Func_Call
)) then
8174 Function_Id
:= Entity
(Name
(Func_Call
));
8176 elsif Nkind
(Name
(Func_Call
)) = N_Explicit_Dereference
then
8177 Function_Id
:= Etype
(Name
(Func_Call
));
8180 raise Program_Error
;
8183 Result_Subt
:= Etype
(Function_Id
);
8186 Definite
: constant Boolean :=
8187 Caller_Known_Size
(Func_Call
, Result_Subt
);
8190 -- Create an access type designating the function's result subtype.
8191 -- We use the type of the original call because it may be a call to
8192 -- an inherited operation, which the expansion has replaced with the
8193 -- parent operation that yields the parent type. Note that this
8194 -- access type must be declared before we establish a transient
8195 -- scope, so that it receives the proper accessibility level.
8197 Ptr_Typ
:= Make_Temporary
(Loc
, 'A');
8199 Make_Full_Type_Declaration
(Loc
,
8200 Defining_Identifier
=> Ptr_Typ
,
8202 Make_Access_To_Object_Definition
(Loc
,
8203 All_Present
=> True,
8204 Subtype_Indication
=>
8205 New_Occurrence_Of
(Etype
(Function_Call
), Loc
)));
8207 -- The access type and its accompanying object must be inserted after
8208 -- the object declaration in the constrained case, so that the
8209 -- function call can be passed access to the object. In the
8210 -- indefinite case, or if the object declaration is for a return
8211 -- object, the access type and object must be inserted before the
8212 -- object, since the object declaration is rewritten to be a renaming
8213 -- of a dereference of the access object. Note: we need to freeze
8214 -- Ptr_Typ explicitly, because the result object is in a different
8215 -- (transient) scope, so won't cause freezing.
8218 and then not Is_Return_Object
(Defining_Identifier
(Obj_Decl
))
8220 Insert_After_And_Analyze
(Obj_Decl
, Ptr_Typ_Decl
);
8222 Insert_Action
(Obj_Decl
, Ptr_Typ_Decl
);
8225 -- Force immediate freezing of Ptr_Typ because Res_Decl will be
8226 -- elaborated in an inner (transient) scope and thus won't cause
8227 -- freezing by itself.
8230 Ptr_Typ_Freeze_Ref
: constant Node_Id
:=
8231 New_Occurrence_Of
(Ptr_Typ
, Loc
);
8233 Set_Parent
(Ptr_Typ_Freeze_Ref
, Ptr_Typ_Decl
);
8234 Freeze_Expression
(Ptr_Typ_Freeze_Ref
);
8237 -- If the object is a return object of an enclosing build-in-place
8238 -- function, then the implicit build-in-place parameters of the
8239 -- enclosing function are simply passed along to the called function.
8240 -- (Unfortunately, this won't cover the case of extension aggregates
8241 -- where the ancestor part is a build-in-place indefinite function
8242 -- call that should be passed along the caller's parameters.
8243 -- Currently those get mishandled by reassigning the result of the
8244 -- call to the aggregate return object, when the call result should
8245 -- really be directly built in place in the aggregate and not in a
8248 if Is_Return_Object
(Defining_Identifier
(Obj_Decl
)) then
8249 Pass_Caller_Acc
:= True;
8251 -- When the enclosing function has a BIP_Alloc_Form formal then we
8252 -- pass it along to the callee (such as when the enclosing
8253 -- function has an unconstrained or tagged result type).
8255 if Needs_BIP_Alloc_Form
(Encl_Func
) then
8256 if RTE_Available
(RE_Root_Storage_Pool_Ptr
) then
8259 (Build_In_Place_Formal
8260 (Encl_Func
, BIP_Storage_Pool
), Loc
);
8262 -- The build-in-place pool formal is not built on e.g. ZFP
8265 Pool_Actual
:= Empty
;
8268 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8269 (Function_Call
=> Func_Call
,
8270 Function_Id
=> Function_Id
,
8273 (Build_In_Place_Formal
(Encl_Func
, BIP_Alloc_Form
), Loc
),
8274 Pool_Actual
=> Pool_Actual
);
8276 -- Otherwise, if enclosing function has a definite result subtype,
8277 -- then caller allocation will be used.
8280 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8281 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8284 if Needs_BIP_Finalization_Master
(Encl_Func
) then
8287 (Build_In_Place_Formal
8288 (Encl_Func
, BIP_Finalization_Master
), Loc
);
8291 -- Retrieve the BIPacc formal from the enclosing function and
8292 -- convert it to the access type of the callee's BIP_Object_Access
8296 Make_Unchecked_Type_Conversion
(Loc
,
8300 (Build_In_Place_Formal
8301 (Function_Id
, BIP_Object_Access
)),
8305 (Build_In_Place_Formal
(Encl_Func
, BIP_Object_Access
),
8308 -- In the definite case, add an implicit actual to the function call
8309 -- that provides access to the declared object. An unchecked
8310 -- conversion to the (specific) result type of the function is
8311 -- inserted to handle the case where the object is declared with a
8316 Make_Unchecked_Type_Conversion
(Loc
,
8317 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Loc
),
8318 Expression
=> New_Occurrence_Of
(Obj_Def_Id
, Loc
));
8320 -- When the function has a controlling result, an allocation-form
8321 -- parameter must be passed indicating that the caller is
8322 -- allocating the result object. This is needed because such a
8323 -- function can be called as a dispatching operation and must be
8324 -- treated similarly to functions with indefinite result subtypes.
8326 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8327 (Func_Call
, Function_Id
, Alloc_Form
=> Caller_Allocation
);
8329 -- The allocation for indefinite library-level objects occurs on the
8330 -- heap as opposed to the secondary stack. This accommodates DLLs
8331 -- where the secondary stack is destroyed after each library
8332 -- unload. This is a hybrid mechanism where a stack-allocated object
8333 -- lives on the heap.
8335 elsif Is_Library_Level_Entity
(Defining_Identifier
(Obj_Decl
))
8336 and then not Restriction_Active
(No_Implicit_Heap_Allocations
)
8338 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8339 (Func_Call
, Function_Id
, Alloc_Form
=> Global_Heap
);
8340 Caller_Object
:= Empty
;
8342 -- Create a finalization master for the access result type to
8343 -- ensure that the heap allocation can properly chain the object
8344 -- and later finalize it when the library unit goes out of scope.
8346 if Needs_Finalization
(Etype
(Func_Call
)) then
8347 Build_Finalization_Master
8349 For_Lib_Level
=> True,
8350 Insertion_Node
=> Ptr_Typ_Decl
);
8353 Make_Attribute_Reference
(Loc
,
8355 New_Occurrence_Of
(Finalization_Master
(Ptr_Typ
), Loc
),
8356 Attribute_Name
=> Name_Unrestricted_Access
);
8359 -- In other indefinite cases, pass an indication to do the allocation
8360 -- on the secondary stack and set Caller_Object to Empty so that a
8361 -- null value will be passed for the caller's object address. A
8362 -- transient scope is established to ensure eventual cleanup of the
8366 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8367 (Func_Call
, Function_Id
, Alloc_Form
=> Secondary_Stack
);
8368 Caller_Object
:= Empty
;
8370 Establish_Transient_Scope
(Obj_Decl
, Sec_Stack
=> True);
8373 -- Pass along any finalization master actual, which is needed in the
8374 -- case where the called function initializes a return object of an
8375 -- enclosing build-in-place function.
8377 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8378 (Func_Call
=> Func_Call
,
8379 Func_Id
=> Function_Id
,
8380 Master_Exp
=> Fmaster_Actual
);
8382 if Nkind
(Parent
(Obj_Decl
)) = N_Extended_Return_Statement
8383 and then Has_Task
(Result_Subt
)
8385 -- Here we're passing along the master that was passed in to this
8388 Add_Task_Actuals_To_Build_In_Place_Call
8389 (Func_Call
, Function_Id
,
8392 (Build_In_Place_Formal
(Encl_Func
, BIP_Task_Master
), Loc
));
8395 Add_Task_Actuals_To_Build_In_Place_Call
8396 (Func_Call
, Function_Id
, Make_Identifier
(Loc
, Name_uMaster
));
8399 Add_Access_Actual_To_Build_In_Place_Call
8403 Is_Access
=> Pass_Caller_Acc
);
8405 -- Finally, create an access object initialized to a reference to the
8406 -- function call. We know this access value cannot be null, so mark
8407 -- the entity accordingly to suppress the access check.
8409 Def_Id
:= Make_Temporary
(Loc
, 'R', Func_Call
);
8410 Set_Etype
(Def_Id
, Ptr_Typ
);
8411 Set_Is_Known_Non_Null
(Def_Id
);
8414 Make_Object_Declaration
(Loc
,
8415 Defining_Identifier
=> Def_Id
,
8416 Constant_Present
=> True,
8417 Object_Definition
=> New_Occurrence_Of
(Ptr_Typ
, Loc
),
8419 Make_Reference
(Loc
, Relocate_Node
(Func_Call
)));
8421 Insert_After_And_Analyze
(Ptr_Typ_Decl
, Res_Decl
);
8423 -- If the result subtype of the called function is definite and is
8424 -- not itself the return expression of an enclosing BIP function,
8425 -- then mark the object as having no initialization.
8428 and then not Is_Return_Object
(Defining_Identifier
(Obj_Decl
))
8430 -- The related object declaration is encased in a transient block
8431 -- because the build-in-place function call contains at least one
8432 -- nested function call that produces a controlled transient
8435 -- Obj : ... := BIP_Func_Call (Ctrl_Func_Call);
8437 -- Since the build-in-place expansion decouples the call from the
8438 -- object declaration, the finalization machinery lacks the
8439 -- context which prompted the generation of the transient
8440 -- block. To resolve this scenario, store the build-in-place call.
8442 if Scope_Is_Transient
and then Node_To_Be_Wrapped
= Obj_Decl
then
8443 Set_BIP_Initialization_Call
(Obj_Def_Id
, Res_Decl
);
8446 Set_Expression
(Obj_Decl
, Empty
);
8447 Set_No_Initialization
(Obj_Decl
);
8449 -- In case of an indefinite result subtype, or if the call is the
8450 -- return expression of an enclosing BIP function, rewrite the object
8451 -- declaration as an object renaming where the renamed object is a
8452 -- dereference of <function_Call>'reference:
8454 -- Obj : Subt renames <function_call>'Ref.all;
8458 Make_Explicit_Dereference
(Obj_Loc
,
8459 Prefix
=> New_Occurrence_Of
(Def_Id
, Obj_Loc
));
8462 Make_Object_Renaming_Declaration
(Obj_Loc
,
8463 Defining_Identifier
=> Make_Temporary
(Obj_Loc
, 'D'),
8464 Subtype_Mark
=> New_Occurrence_Of
(Result_Subt
, Obj_Loc
),
8465 Name
=> Call_Deref
));
8467 Set_Renamed_Object
(Defining_Identifier
(Obj_Decl
), Call_Deref
);
8469 -- If the original entity comes from source, then mark the new
8470 -- entity as needing debug information, even though it's defined
8471 -- by a generated renaming that does not come from source, so that
8472 -- the Materialize_Entity flag will be set on the entity when
8473 -- Debug_Renaming_Declaration is called during analysis.
8475 if Comes_From_Source
(Obj_Def_Id
) then
8476 Set_Debug_Info_Needed
(Defining_Identifier
(Obj_Decl
));
8480 Replace_Renaming_Declaration_Id
8481 (Obj_Decl
, Original_Node
(Obj_Decl
));
8485 -- If the object entity has a class-wide Etype, then we need to change
8486 -- it to the result subtype of the function call, because otherwise the
8487 -- object will be class-wide without an explicit initialization and
8488 -- won't be allocated properly by the back end. It seems unclean to make
8489 -- such a revision to the type at this point, and we should try to
8490 -- improve this treatment when build-in-place functions with class-wide
8491 -- results are implemented. ???
8493 if Is_Class_Wide_Type
(Etype
(Defining_Identifier
(Obj_Decl
))) then
8494 Set_Etype
(Defining_Identifier
(Obj_Decl
), Result_Subt
);
8496 end Make_Build_In_Place_Call_In_Object_Declaration
;
8498 -------------------------------------------------
8499 -- Make_Build_In_Place_Iface_Call_In_Allocator --
8500 -------------------------------------------------
8502 procedure Make_Build_In_Place_Iface_Call_In_Allocator
8503 (Allocator
: Node_Id
;
8504 Function_Call
: Node_Id
)
8506 BIP_Func_Call
: constant Node_Id
:=
8507 Unqual_BIP_Iface_Function_Call
(Function_Call
);
8508 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8510 Anon_Type
: Entity_Id
;
8515 -- No action of the call has already been processed
8517 if Is_Expanded_Build_In_Place_Call
(BIP_Func_Call
) then
8521 Tmp_Id
:= Make_Temporary
(Loc
, 'D');
8523 -- Insert a temporary before N initialized with the BIP function call
8524 -- without its enclosing type conversions and analyze it without its
8525 -- expansion. This temporary facilitates us reusing the BIP machinery,
8526 -- which takes care of adding the extra build-in-place actuals and
8527 -- transforms this object declaration into an object renaming
8530 Anon_Type
:= Create_Itype
(E_Anonymous_Access_Type
, Function_Call
);
8531 Set_Directly_Designated_Type
(Anon_Type
, Etype
(BIP_Func_Call
));
8532 Set_Etype
(Anon_Type
, Anon_Type
);
8535 Make_Object_Declaration
(Loc
,
8536 Defining_Identifier
=> Tmp_Id
,
8537 Object_Definition
=> New_Occurrence_Of
(Anon_Type
, Loc
),
8539 Make_Allocator
(Loc
,
8541 Make_Qualified_Expression
(Loc
,
8543 New_Occurrence_Of
(Etype
(BIP_Func_Call
), Loc
),
8544 Expression
=> New_Copy_Tree
(BIP_Func_Call
))));
8546 Expander_Mode_Save_And_Set
(False);
8547 Insert_Action
(Allocator
, Tmp_Decl
);
8548 Expander_Mode_Restore
;
8550 Make_Build_In_Place_Call_In_Allocator
8551 (Allocator
=> Expression
(Tmp_Decl
),
8552 Function_Call
=> Expression
(Expression
(Tmp_Decl
)));
8554 Rewrite
(Allocator
, New_Occurrence_Of
(Tmp_Id
, Loc
));
8555 end Make_Build_In_Place_Iface_Call_In_Allocator
;
8557 ---------------------------------------------------------
8558 -- Make_Build_In_Place_Iface_Call_In_Anonymous_Context --
8559 ---------------------------------------------------------
8561 procedure Make_Build_In_Place_Iface_Call_In_Anonymous_Context
8562 (Function_Call
: Node_Id
)
8564 BIP_Func_Call
: constant Node_Id
:=
8565 Unqual_BIP_Iface_Function_Call
(Function_Call
);
8566 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8572 -- No action of the call has already been processed
8574 if Is_Expanded_Build_In_Place_Call
(BIP_Func_Call
) then
8578 pragma Assert
(Needs_Finalization
(Etype
(BIP_Func_Call
)));
8580 -- Insert a temporary before the call initialized with function call to
8581 -- reuse the BIP machinery which takes care of adding the extra build-in
8582 -- place actuals and transforms this object declaration into an object
8583 -- renaming declaration.
8585 Tmp_Id
:= Make_Temporary
(Loc
, 'D');
8588 Make_Object_Declaration
(Loc
,
8589 Defining_Identifier
=> Tmp_Id
,
8590 Object_Definition
=>
8591 New_Occurrence_Of
(Etype
(Function_Call
), Loc
),
8592 Expression
=> Relocate_Node
(Function_Call
));
8594 Expander_Mode_Save_And_Set
(False);
8595 Insert_Action
(Function_Call
, Tmp_Decl
);
8596 Expander_Mode_Restore
;
8598 Make_Build_In_Place_Iface_Call_In_Object_Declaration
8599 (Obj_Decl
=> Tmp_Decl
,
8600 Function_Call
=> Expression
(Tmp_Decl
));
8601 end Make_Build_In_Place_Iface_Call_In_Anonymous_Context
;
8603 ----------------------------------------------------------
8604 -- Make_Build_In_Place_Iface_Call_In_Object_Declaration --
8605 ----------------------------------------------------------
8607 procedure Make_Build_In_Place_Iface_Call_In_Object_Declaration
8608 (Obj_Decl
: Node_Id
;
8609 Function_Call
: Node_Id
)
8611 BIP_Func_Call
: constant Node_Id
:=
8612 Unqual_BIP_Iface_Function_Call
(Function_Call
);
8613 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8614 Obj_Id
: constant Entity_Id
:= Defining_Entity
(Obj_Decl
);
8620 -- No action of the call has already been processed
8622 if Is_Expanded_Build_In_Place_Call
(BIP_Func_Call
) then
8626 Tmp_Id
:= Make_Temporary
(Loc
, 'D');
8628 -- Insert a temporary before N initialized with the BIP function call
8629 -- without its enclosing type conversions and analyze it without its
8630 -- expansion. This temporary facilitates us reusing the BIP machinery,
8631 -- which takes care of adding the extra build-in-place actuals and
8632 -- transforms this object declaration into an object renaming
8636 Make_Object_Declaration
(Loc
,
8637 Defining_Identifier
=> Tmp_Id
,
8638 Object_Definition
=>
8639 New_Occurrence_Of
(Etype
(BIP_Func_Call
), Loc
),
8640 Expression
=> New_Copy_Tree
(BIP_Func_Call
));
8642 Expander_Mode_Save_And_Set
(False);
8643 Insert_Action
(Obj_Decl
, Tmp_Decl
);
8644 Expander_Mode_Restore
;
8646 Make_Build_In_Place_Call_In_Object_Declaration
8647 (Obj_Decl
=> Tmp_Decl
,
8648 Function_Call
=> Expression
(Tmp_Decl
));
8650 pragma Assert
(Nkind
(Tmp_Decl
) = N_Object_Renaming_Declaration
);
8652 -- Replace the original build-in-place function call by a reference to
8653 -- the resulting temporary object renaming declaration. In this way,
8654 -- all the interface conversions performed in the original Function_Call
8655 -- on the build-in-place object are preserved.
8657 Rewrite
(BIP_Func_Call
, New_Occurrence_Of
(Tmp_Id
, Loc
));
8659 -- Replace the original object declaration by an internal object
8660 -- renaming declaration. This leaves the generated code more clean (the
8661 -- build-in-place function call in an object renaming declaration and
8662 -- displacements of the pointer to the build-in-place object in another
8663 -- renaming declaration) and allows us to invoke the routine that takes
8664 -- care of replacing the identifier of the renaming declaration (routine
8665 -- originally developed for the regular build-in-place management).
8668 Make_Object_Renaming_Declaration
(Loc
,
8669 Defining_Identifier
=> Make_Temporary
(Loc
, 'D'),
8670 Subtype_Mark
=> New_Occurrence_Of
(Etype
(Obj_Id
), Loc
),
8671 Name
=> Function_Call
));
8674 Replace_Renaming_Declaration_Id
(Obj_Decl
, Original_Node
(Obj_Decl
));
8675 end Make_Build_In_Place_Iface_Call_In_Object_Declaration
;
8677 --------------------------------------------
8678 -- Make_CPP_Constructor_Call_In_Allocator --
8679 --------------------------------------------
8681 procedure Make_CPP_Constructor_Call_In_Allocator
8682 (Allocator
: Node_Id
;
8683 Function_Call
: Node_Id
)
8685 Loc
: constant Source_Ptr
:= Sloc
(Function_Call
);
8686 Acc_Type
: constant Entity_Id
:= Etype
(Allocator
);
8687 Function_Id
: constant Entity_Id
:= Entity
(Name
(Function_Call
));
8688 Result_Subt
: constant Entity_Id
:= Available_View
(Etype
(Function_Id
));
8690 New_Allocator
: Node_Id
;
8691 Return_Obj_Access
: Entity_Id
;
8695 pragma Assert
(Nkind
(Allocator
) = N_Allocator
8696 and then Nkind
(Function_Call
) = N_Function_Call
);
8697 pragma Assert
(Convention
(Function_Id
) = Convention_CPP
8698 and then Is_Constructor
(Function_Id
));
8699 pragma Assert
(Is_Constrained
(Underlying_Type
(Result_Subt
)));
8701 -- Replace the initialized allocator of form "new T'(Func (...))" with
8702 -- an uninitialized allocator of form "new T", where T is the result
8703 -- subtype of the called function. The call to the function is handled
8704 -- separately further below.
8707 Make_Allocator
(Loc
,
8708 Expression
=> New_Occurrence_Of
(Result_Subt
, Loc
));
8709 Set_No_Initialization
(New_Allocator
);
8711 -- Copy attributes to new allocator. Note that the new allocator
8712 -- logically comes from source if the original one did, so copy the
8713 -- relevant flag. This ensures proper treatment of the restriction
8714 -- No_Implicit_Heap_Allocations in this case.
8716 Set_Storage_Pool
(New_Allocator
, Storage_Pool
(Allocator
));
8717 Set_Procedure_To_Call
(New_Allocator
, Procedure_To_Call
(Allocator
));
8718 Set_Comes_From_Source
(New_Allocator
, Comes_From_Source
(Allocator
));
8720 Rewrite
(Allocator
, New_Allocator
);
8722 -- Create a new access object and initialize it to the result of the
8723 -- new uninitialized allocator. Note: we do not use Allocator as the
8724 -- Related_Node of Return_Obj_Access in call to Make_Temporary below
8725 -- as this would create a sort of infinite "recursion".
8727 Return_Obj_Access
:= Make_Temporary
(Loc
, 'R');
8728 Set_Etype
(Return_Obj_Access
, Acc_Type
);
8731 -- Rnnn : constant ptr_T := new (T);
8732 -- Init (Rnn.all,...);
8735 Make_Object_Declaration
(Loc
,
8736 Defining_Identifier
=> Return_Obj_Access
,
8737 Constant_Present
=> True,
8738 Object_Definition
=> New_Occurrence_Of
(Acc_Type
, Loc
),
8739 Expression
=> Relocate_Node
(Allocator
));
8740 Insert_Action
(Allocator
, Tmp_Obj
);
8742 Insert_List_After_And_Analyze
(Tmp_Obj
,
8743 Build_Initialization_Call
(Loc
,
8745 Make_Explicit_Dereference
(Loc
,
8746 Prefix
=> New_Occurrence_Of
(Return_Obj_Access
, Loc
)),
8747 Typ
=> Etype
(Function_Id
),
8748 Constructor_Ref
=> Function_Call
));
8750 -- Finally, replace the allocator node with a reference to the result of
8751 -- the function call itself (which will effectively be an access to the
8752 -- object created by the allocator).
8754 Rewrite
(Allocator
, New_Occurrence_Of
(Return_Obj_Access
, Loc
));
8756 -- Ada 2005 (AI-251): If the type of the allocator is an interface then
8757 -- generate an implicit conversion to force displacement of the "this"
8760 if Is_Interface
(Designated_Type
(Acc_Type
)) then
8761 Rewrite
(Allocator
, Convert_To
(Acc_Type
, Relocate_Node
(Allocator
)));
8764 Analyze_And_Resolve
(Allocator
, Acc_Type
);
8765 end Make_CPP_Constructor_Call_In_Allocator
;
8767 -----------------------------------
8768 -- Needs_BIP_Finalization_Master --
8769 -----------------------------------
8771 function Needs_BIP_Finalization_Master
8772 (Func_Id
: Entity_Id
) return Boolean
8774 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
8775 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
8777 -- A formal giving the finalization master is needed for build-in-place
8778 -- functions whose result type needs finalization or is a tagged type.
8779 -- Tagged primitive build-in-place functions need such a formal because
8780 -- they can be called by a dispatching call, and extensions may require
8781 -- finalization even if the root type doesn't. This means they're also
8782 -- needed for tagged nonprimitive build-in-place functions with tagged
8783 -- results, since such functions can be called via access-to-function
8784 -- types, and those can be used to call primitives, so masters have to
8785 -- be passed to all such build-in-place functions, primitive or not.
8788 not Restriction_Active
(No_Finalization
)
8789 and then (Needs_Finalization
(Func_Typ
)
8790 or else Is_Tagged_Type
(Func_Typ
));
8791 end Needs_BIP_Finalization_Master
;
8793 --------------------------
8794 -- Needs_BIP_Alloc_Form --
8795 --------------------------
8797 function Needs_BIP_Alloc_Form
(Func_Id
: Entity_Id
) return Boolean is
8798 pragma Assert
(Is_Build_In_Place_Function
(Func_Id
));
8799 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
8801 return not Is_Constrained
(Func_Typ
) or else Is_Tagged_Type
(Func_Typ
);
8802 end Needs_BIP_Alloc_Form
;
8804 --------------------------------------
8805 -- Needs_Result_Accessibility_Level --
8806 --------------------------------------
8808 function Needs_Result_Accessibility_Level
8809 (Func_Id
: Entity_Id
) return Boolean
8811 Func_Typ
: constant Entity_Id
:= Underlying_Type
(Etype
(Func_Id
));
8813 function Has_Unconstrained_Access_Discriminant_Component
8814 (Comp_Typ
: Entity_Id
) return Boolean;
8815 -- Returns True if any component of the type has an unconstrained access
8818 -----------------------------------------------------
8819 -- Has_Unconstrained_Access_Discriminant_Component --
8820 -----------------------------------------------------
8822 function Has_Unconstrained_Access_Discriminant_Component
8823 (Comp_Typ
: Entity_Id
) return Boolean
8826 if not Is_Limited_Type
(Comp_Typ
) then
8829 -- Only limited types can have access discriminants with
8832 elsif Has_Unconstrained_Access_Discriminants
(Comp_Typ
) then
8835 elsif Is_Array_Type
(Comp_Typ
) then
8836 return Has_Unconstrained_Access_Discriminant_Component
8837 (Underlying_Type
(Component_Type
(Comp_Typ
)));
8839 elsif Is_Record_Type
(Comp_Typ
) then
8844 Comp
:= First_Component
(Comp_Typ
);
8845 while Present
(Comp
) loop
8846 if Has_Unconstrained_Access_Discriminant_Component
8847 (Underlying_Type
(Etype
(Comp
)))
8852 Next_Component
(Comp
);
8858 end Has_Unconstrained_Access_Discriminant_Component
;
8860 Feature_Disabled
: constant Boolean := True;
8863 -- Start of processing for Needs_Result_Accessibility_Level
8866 -- False if completion unavailable (how does this happen???)
8868 if not Present
(Func_Typ
) then
8871 elsif Feature_Disabled
then
8874 -- False if not a function, also handle enum-lit renames case
8876 elsif Func_Typ
= Standard_Void_Type
8877 or else Is_Scalar_Type
(Func_Typ
)
8881 -- Handle a corner case, a cross-dialect subp renaming. For example,
8882 -- an Ada 2012 renaming of an Ada 2005 subprogram. This can occur when
8883 -- an Ada 2005 (or earlier) unit references predefined run-time units.
8885 elsif Present
(Alias
(Func_Id
)) then
8887 -- Unimplemented: a cross-dialect subp renaming which does not set
8888 -- the Alias attribute (e.g., a rename of a dereference of an access
8889 -- to subprogram value). ???
8891 return Present
(Extra_Accessibility_Of_Result
(Alias
(Func_Id
)));
8893 -- Remaining cases require Ada 2012 mode
8895 elsif Ada_Version
< Ada_2012
then
8898 elsif Ekind
(Func_Typ
) = E_Anonymous_Access_Type
8899 or else Is_Tagged_Type
(Func_Typ
)
8901 -- In the case of, say, a null tagged record result type, the need
8902 -- for this extra parameter might not be obvious. This function
8903 -- returns True for all tagged types for compatibility reasons.
8904 -- A function with, say, a tagged null controlling result type might
8905 -- be overridden by a primitive of an extension having an access
8906 -- discriminant and the overrider and overridden must have compatible
8907 -- calling conventions (including implicitly declared parameters).
8908 -- Similarly, values of one access-to-subprogram type might designate
8909 -- both a primitive subprogram of a given type and a function
8910 -- which is, for example, not a primitive subprogram of any type.
8911 -- Again, this requires calling convention compatibility.
8912 -- It might be possible to solve these issues by introducing
8913 -- wrappers, but that is not the approach that was chosen.
8917 elsif Has_Unconstrained_Access_Discriminants
(Func_Typ
) then
8920 elsif Has_Unconstrained_Access_Discriminant_Component
(Func_Typ
) then
8923 -- False for all other cases
8928 end Needs_Result_Accessibility_Level
;
8930 -------------------------------------
8931 -- Replace_Renaming_Declaration_Id --
8932 -------------------------------------
8934 procedure Replace_Renaming_Declaration_Id
8935 (New_Decl
: Node_Id
;
8936 Orig_Decl
: Node_Id
)
8938 New_Id
: constant Entity_Id
:= Defining_Entity
(New_Decl
);
8939 Orig_Id
: constant Entity_Id
:= Defining_Entity
(Orig_Decl
);
8942 Set_Chars
(New_Id
, Chars
(Orig_Id
));
8944 -- Swap next entity links in preparation for exchanging entities
8947 Next_Id
: constant Entity_Id
:= Next_Entity
(New_Id
);
8949 Set_Next_Entity
(New_Id
, Next_Entity
(Orig_Id
));
8950 Set_Next_Entity
(Orig_Id
, Next_Id
);
8953 Set_Homonym
(New_Id
, Homonym
(Orig_Id
));
8954 Exchange_Entities
(New_Id
, Orig_Id
);
8956 -- Preserve source indication of original declaration, so that xref
8957 -- information is properly generated for the right entity.
8959 Preserve_Comes_From_Source
(New_Decl
, Orig_Decl
);
8960 Preserve_Comes_From_Source
(Orig_Id
, Orig_Decl
);
8962 Set_Comes_From_Source
(New_Id
, False);
8963 end Replace_Renaming_Declaration_Id
;
8965 ---------------------------------
8966 -- Rewrite_Function_Call_For_C --
8967 ---------------------------------
8969 procedure Rewrite_Function_Call_For_C
(N
: Node_Id
) is
8970 Orig_Func
: constant Entity_Id
:= Entity
(Name
(N
));
8971 Func_Id
: constant Entity_Id
:= Ultimate_Alias
(Orig_Func
);
8972 Par
: constant Node_Id
:= Parent
(N
);
8973 Proc_Id
: constant Entity_Id
:= Corresponding_Procedure
(Func_Id
);
8974 Loc
: constant Source_Ptr
:= Sloc
(Par
);
8976 Last_Actual
: Node_Id
;
8977 Last_Formal
: Entity_Id
;
8979 -- Start of processing for Rewrite_Function_Call_For_C
8982 -- The actuals may be given by named associations, so the added actual
8983 -- that is the target of the return value of the call must be a named
8984 -- association as well, so we retrieve the name of the generated
8987 Last_Formal
:= First_Formal
(Proc_Id
);
8988 while Present
(Next_Formal
(Last_Formal
)) loop
8989 Last_Formal
:= Next_Formal
(Last_Formal
);
8992 Actuals
:= Parameter_Associations
(N
);
8994 -- The original function may lack parameters
8996 if No
(Actuals
) then
8997 Actuals
:= New_List
;
9000 -- If the function call is the expression of an assignment statement,
9001 -- transform the assignment into a procedure call. Generate:
9003 -- LHS := Func_Call (...);
9005 -- Proc_Call (..., LHS);
9007 -- If function is inherited, a conversion may be necessary.
9009 if Nkind
(Par
) = N_Assignment_Statement
then
9010 Last_Actual
:= Name
(Par
);
9012 if not Comes_From_Source
(Orig_Func
)
9013 and then Etype
(Orig_Func
) /= Etype
(Func_Id
)
9016 Make_Type_Conversion
(Loc
,
9017 New_Occurrence_Of
(Etype
(Func_Id
), Loc
),
9022 Make_Parameter_Association
(Loc
,
9024 Make_Identifier
(Loc
, Chars
(Last_Formal
)),
9025 Explicit_Actual_Parameter
=> Last_Actual
));
9028 Make_Procedure_Call_Statement
(Loc
,
9029 Name
=> New_Occurrence_Of
(Proc_Id
, Loc
),
9030 Parameter_Associations
=> Actuals
));
9033 -- Otherwise the context is an expression. Generate a temporary and a
9034 -- procedure call to obtain the function result. Generate:
9036 -- ... Func_Call (...) ...
9039 -- Proc_Call (..., Temp);
9044 Temp_Id
: constant Entity_Id
:= Make_Temporary
(Loc
, 'T');
9053 Make_Object_Declaration
(Loc
,
9054 Defining_Identifier
=> Temp_Id
,
9055 Object_Definition
=>
9056 New_Occurrence_Of
(Etype
(Func_Id
), Loc
));
9059 -- Proc_Call (..., Temp);
9062 Make_Parameter_Association
(Loc
,
9064 Make_Identifier
(Loc
, Chars
(Last_Formal
)),
9065 Explicit_Actual_Parameter
=>
9066 New_Occurrence_Of
(Temp_Id
, Loc
)));
9069 Make_Procedure_Call_Statement
(Loc
,
9070 Name
=> New_Occurrence_Of
(Proc_Id
, Loc
),
9071 Parameter_Associations
=> Actuals
);
9073 Insert_Actions
(Par
, New_List
(Decl
, Call
));
9074 Rewrite
(N
, New_Occurrence_Of
(Temp_Id
, Loc
));
9077 end Rewrite_Function_Call_For_C
;
9079 ------------------------------------
9080 -- Set_Enclosing_Sec_Stack_Return --
9081 ------------------------------------
9083 procedure Set_Enclosing_Sec_Stack_Return
(N
: Node_Id
) is
9087 -- Due to a possible mix of internally generated blocks, source blocks
9088 -- and loops, the scope stack may not be contiguous as all labels are
9089 -- inserted at the top level within the related function. Instead,
9090 -- perform a parent-based traversal and mark all appropriate constructs.
9092 while Present
(P
) loop
9094 -- Mark the label of a source or internally generated block or
9097 if Nkind_In
(P
, N_Block_Statement
, N_Loop_Statement
) then
9098 Set_Sec_Stack_Needed_For_Return
(Entity
(Identifier
(P
)));
9100 -- Mark the enclosing function
9102 elsif Nkind
(P
) = N_Subprogram_Body
then
9103 if Present
(Corresponding_Spec
(P
)) then
9104 Set_Sec_Stack_Needed_For_Return
(Corresponding_Spec
(P
));
9106 Set_Sec_Stack_Needed_For_Return
(Defining_Entity
(P
));
9109 -- Do not go beyond the enclosing function
9116 end Set_Enclosing_Sec_Stack_Return
;
9118 ------------------------------------
9119 -- Unqual_BIP_Iface_Function_Call --
9120 ------------------------------------
9122 function Unqual_BIP_Iface_Function_Call
(Expr
: Node_Id
) return Node_Id
is
9123 Has_Pointer_Displacement
: Boolean := False;
9124 On_Object_Declaration
: Boolean := False;
9125 -- Remember if processing the renaming expressions on recursion we have
9126 -- traversed an object declaration, since we can traverse many object
9127 -- declaration renamings but just one regular object declaration.
9129 function Unqual_BIP_Function_Call
(Expr
: Node_Id
) return Node_Id
;
9130 -- Search for a build-in-place function call skipping any qualification
9131 -- including qualified expressions, type conversions, references, calls
9132 -- to displace the pointer to the object, and renamings. Return Empty if
9133 -- no build-in-place function call is found.
9135 ------------------------------
9136 -- Unqual_BIP_Function_Call --
9137 ------------------------------
9139 function Unqual_BIP_Function_Call
(Expr
: Node_Id
) return Node_Id
is
9141 -- Recurse to handle case of multiple levels of qualification and/or
9144 if Nkind_In
(Expr
, N_Qualified_Expression
,
9146 N_Unchecked_Type_Conversion
)
9148 return Unqual_BIP_Function_Call
(Expression
(Expr
));
9150 -- Recurse to handle case of multiple levels of references and
9151 -- explicit dereferences.
9153 elsif Nkind_In
(Expr
, N_Attribute_Reference
,
9154 N_Explicit_Dereference
,
9157 return Unqual_BIP_Function_Call
(Prefix
(Expr
));
9159 -- Recurse on object renamings
9161 elsif Nkind
(Expr
) = N_Identifier
9162 and then Present
(Entity
(Expr
))
9163 and then Ekind_In
(Entity
(Expr
), E_Constant
, E_Variable
)
9164 and then Nkind
(Parent
(Entity
(Expr
))) =
9165 N_Object_Renaming_Declaration
9166 and then Present
(Renamed_Object
(Entity
(Expr
)))
9168 return Unqual_BIP_Function_Call
(Renamed_Object
(Entity
(Expr
)));
9170 -- Recurse on the initializing expression of the first reference of
9171 -- an object declaration.
9173 elsif not On_Object_Declaration
9174 and then Nkind
(Expr
) = N_Identifier
9175 and then Present
(Entity
(Expr
))
9176 and then Ekind_In
(Entity
(Expr
), E_Constant
, E_Variable
)
9177 and then Nkind
(Parent
(Entity
(Expr
))) = N_Object_Declaration
9178 and then Present
(Expression
(Parent
(Entity
(Expr
))))
9180 On_Object_Declaration
:= True;
9182 Unqual_BIP_Function_Call
(Expression
(Parent
(Entity
(Expr
))));
9184 -- Recurse to handle calls to displace the pointer to the object to
9185 -- reference a secondary dispatch table.
9187 elsif Nkind
(Expr
) = N_Function_Call
9188 and then Nkind
(Name
(Expr
)) in N_Has_Entity
9189 and then Present
(Entity
(Name
(Expr
)))
9190 and then RTU_Loaded
(Ada_Tags
)
9191 and then RTE_Available
(RE_Displace
)
9192 and then Is_RTE
(Entity
(Name
(Expr
)), RE_Displace
)
9194 Has_Pointer_Displacement
:= True;
9196 Unqual_BIP_Function_Call
(First
(Parameter_Associations
(Expr
)));
9198 -- Normal case: check if the inner expression is a BIP function call
9199 -- and the pointer to the object is displaced.
9201 elsif Has_Pointer_Displacement
9202 and then Is_Build_In_Place_Function_Call
(Expr
)
9209 end Unqual_BIP_Function_Call
;
9211 -- Start of processing for Unqual_BIP_Iface_Function_Call
9214 return Unqual_BIP_Function_Call
(Expr
);
9215 end Unqual_BIP_Iface_Function_Call
;