1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2012, 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 Debug; use Debug;
29 with Einfo; use Einfo;
30 with Errout; use Errout;
31 with Elists; use Elists;
32 with Exp_Aggr; use Exp_Aggr;
33 with Exp_Atag; use Exp_Atag;
34 with Exp_Ch2; use Exp_Ch2;
35 with Exp_Ch3; use Exp_Ch3;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Ch9; use Exp_Ch9;
38 with Exp_Dbug; use Exp_Dbug;
39 with Exp_Disp; use Exp_Disp;
40 with Exp_Dist; use Exp_Dist;
41 with Exp_Intr; use Exp_Intr;
42 with Exp_Pakd; use Exp_Pakd;
43 with Exp_Tss; use Exp_Tss;
44 with Exp_Util; use Exp_Util;
45 with Exp_VFpt; use Exp_VFpt;
46 with Fname; use Fname;
47 with Freeze; use Freeze;
48 with Inline; use Inline;
50 with Namet; use Namet;
51 with Nlists; use Nlists;
52 with Nmake; use Nmake;
54 with Restrict; use Restrict;
55 with Rident; use Rident;
56 with Rtsfind; use Rtsfind;
58 with Sem_Aux; use Sem_Aux;
59 with Sem_Ch6; use Sem_Ch6;
60 with Sem_Ch8; use Sem_Ch8;
61 with Sem_Ch12; use Sem_Ch12;
62 with Sem_Ch13; use Sem_Ch13;
63 with Sem_Dim; use Sem_Dim;
64 with Sem_Disp; use Sem_Disp;
65 with Sem_Dist; use Sem_Dist;
66 with Sem_Eval; use Sem_Eval;
67 with Sem_Mech; use Sem_Mech;
68 with Sem_Res; use Sem_Res;
69 with Sem_SCIL; use Sem_SCIL;
70 with Sem_Util; use Sem_Util;
71 with Sinfo; use Sinfo;
72 with Snames; use Snames;
73 with Stand; use Stand;
74 with Targparm; use Targparm;
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 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
127 -- contains tasks, add two actual parameters: the master, and a pointer to
128 -- the caller's activation chain. Master_Actual is the actual parameter
129 -- expression to pass for the master. In most cases, this is the current
130 -- master (_master). The two exceptions are: If the function call is the
131 -- initialization expression for an allocator, we pass the master of the
132 -- access type. If the function call is the initialization expression for a
133 -- return object, we pass along the master passed in by the caller. The
134 -- activation chain to pass is always the local one. Note: Master_Actual
135 -- can be Empty, but only if there are no tasks.
137 procedure Check_Overriding_Operation (Subp : Entity_Id);
138 -- Subp is a dispatching operation. Check whether it may override an
139 -- inherited private operation, in which case its DT entry is that of
140 -- the hidden operation, not the one it may have received earlier.
141 -- This must be done before emitting the code to set the corresponding
142 -- DT to the address of the subprogram. The actual placement of Subp in
143 -- the proper place in the list of primitive operations is done in
144 -- Declare_Inherited_Private_Subprograms, which also has to deal with
145 -- implicit operations. This duplication is unavoidable for now???
147 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
148 -- This procedure is called only if the subprogram body N, whose spec
149 -- has the given entity Spec, contains a parameterless recursive call.
150 -- It attempts to generate runtime code to detect if this a case of
151 -- infinite recursion.
153 -- The body is scanned to determine dependencies. If the only external
154 -- dependencies are on a small set of scalar variables, then the values
155 -- of these variables are captured on entry to the subprogram, and if
156 -- the values are not changed for the call, we know immediately that
157 -- we have an infinite recursion.
159 procedure Expand_Ctrl_Function_Call (N : Node_Id);
160 -- N is a function call which returns a controlled object. Transform the
161 -- call into a temporary which retrieves the returned object from the
162 -- secondary stack using 'reference.
164 procedure Expand_Inlined_Call
167 Orig_Subp : Entity_Id);
168 -- If called subprogram can be inlined by the front-end, retrieve the
169 -- analyzed body, replace formals with actuals and expand call in place.
170 -- Generate thunks for actuals that are expressions, and insert the
171 -- corresponding constant declarations before the call. If the original
172 -- call is to a derived operation, the return type is the one of the
173 -- derived operation, but the body is that of the original, so return
174 -- expressions in the body must be converted to the desired type (which
175 -- is simply not noted in the tree without inline expansion).
177 procedure Expand_Non_Function_Return (N : Node_Id);
178 -- Called by Expand_N_Simple_Return_Statement in case we're returning from
179 -- a procedure body, entry body, accept statement, or extended return
180 -- statement. Note that all non-function returns are simple return
183 function Expand_Protected_Object_Reference
185 Scop : Entity_Id) return Node_Id;
187 procedure Expand_Protected_Subprogram_Call
191 -- A call to a protected subprogram within the protected object may appear
192 -- as a regular call. The list of actuals must be expanded to contain a
193 -- reference to the object itself, and the call becomes a call to the
194 -- corresponding protected subprogram.
196 function Has_Unconstrained_Access_Discriminants
197 (Subtyp : Entity_Id) return Boolean;
198 -- Returns True if the given subtype is unconstrained and has one
199 -- or more access discriminants.
201 procedure Expand_Simple_Function_Return (N : Node_Id);
202 -- Expand simple return from function. In the case where we are returning
203 -- from a function body this is called by Expand_N_Simple_Return_Statement.
205 ----------------------------------------------
206 -- Add_Access_Actual_To_Build_In_Place_Call --
207 ----------------------------------------------
209 procedure Add_Access_Actual_To_Build_In_Place_Call
210 (Function_Call : Node_Id;
211 Function_Id : Entity_Id;
212 Return_Object : Node_Id;
213 Is_Access : Boolean := False)
215 Loc : constant Source_Ptr := Sloc (Function_Call);
216 Obj_Address : Node_Id;
217 Obj_Acc_Formal : Entity_Id;
220 -- Locate the implicit access parameter in the called function
222 Obj_Acc_Formal := Build_In_Place_Formal (Function_Id, BIP_Object_Access);
224 -- If no return object is provided, then pass null
226 if not Present (Return_Object) then
227 Obj_Address := Make_Null (Loc);
228 Set_Parent (Obj_Address, Function_Call);
230 -- If Return_Object is already an expression of an access type, then use
231 -- it directly, since it must be an access value denoting the return
232 -- object, and couldn't possibly be the return object itself.
235 Obj_Address := Return_Object;
236 Set_Parent (Obj_Address, Function_Call);
238 -- Apply Unrestricted_Access to caller's return object
242 Make_Attribute_Reference (Loc,
243 Prefix => Return_Object,
244 Attribute_Name => Name_Unrestricted_Access);
246 Set_Parent (Return_Object, Obj_Address);
247 Set_Parent (Obj_Address, Function_Call);
250 Analyze_And_Resolve (Obj_Address, Etype (Obj_Acc_Formal));
252 -- Build the parameter association for the new actual and add it to the
253 -- end of the function's actuals.
255 Add_Extra_Actual_To_Call (Function_Call, Obj_Acc_Formal, Obj_Address);
256 end Add_Access_Actual_To_Build_In_Place_Call;
258 ------------------------------------------------------
259 -- Add_Unconstrained_Actuals_To_Build_In_Place_Call --
260 ------------------------------------------------------
262 procedure Add_Unconstrained_Actuals_To_Build_In_Place_Call
263 (Function_Call : Node_Id;
264 Function_Id : Entity_Id;
265 Alloc_Form : BIP_Allocation_Form := Unspecified;
266 Alloc_Form_Exp : Node_Id := Empty;
267 Pool_Actual : Node_Id := Make_Null (No_Location))
269 Loc : constant Source_Ptr := Sloc (Function_Call);
270 Alloc_Form_Actual : Node_Id;
271 Alloc_Form_Formal : Node_Id;
272 Pool_Formal : Node_Id;
275 -- The allocation form generally doesn't need to be passed in the case
276 -- of a constrained result subtype, since normally the caller performs
277 -- the allocation in that case. However this formal is still needed in
278 -- the case where the function has a tagged result, because generally
279 -- such functions can be called in a dispatching context and such calls
280 -- must be handled like calls to class-wide functions.
282 if Is_Constrained (Underlying_Type (Etype (Function_Id)))
283 and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
288 -- Locate the implicit allocation form parameter in the called function.
289 -- Maybe it would be better for each implicit formal of a build-in-place
290 -- function to have a flag or a Uint attribute to identify it. ???
292 Alloc_Form_Formal := Build_In_Place_Formal (Function_Id, BIP_Alloc_Form);
294 if Present (Alloc_Form_Exp) then
295 pragma Assert (Alloc_Form = Unspecified);
297 Alloc_Form_Actual := Alloc_Form_Exp;
300 pragma Assert (Alloc_Form /= Unspecified);
303 Make_Integer_Literal (Loc,
304 Intval => UI_From_Int (BIP_Allocation_Form'Pos (Alloc_Form)));
307 Analyze_And_Resolve (Alloc_Form_Actual, Etype (Alloc_Form_Formal));
309 -- Build the parameter association for the new actual and add it to the
310 -- end of the function's actuals.
312 Add_Extra_Actual_To_Call
313 (Function_Call, Alloc_Form_Formal, Alloc_Form_Actual);
315 -- Pass the Storage_Pool parameter. This parameter is omitted on
316 -- .NET/JVM/ZFP as those targets do not support pools.
319 and then RTE_Available (RE_Root_Storage_Pool_Ptr)
321 Pool_Formal := Build_In_Place_Formal (Function_Id, BIP_Storage_Pool);
322 Analyze_And_Resolve (Pool_Actual, Etype (Pool_Formal));
323 Add_Extra_Actual_To_Call
324 (Function_Call, Pool_Formal, Pool_Actual);
326 end Add_Unconstrained_Actuals_To_Build_In_Place_Call;
328 -----------------------------------------------------------
329 -- Add_Finalization_Master_Actual_To_Build_In_Place_Call --
330 -----------------------------------------------------------
332 procedure Add_Finalization_Master_Actual_To_Build_In_Place_Call
333 (Func_Call : Node_Id;
335 Ptr_Typ : Entity_Id := Empty;
336 Master_Exp : Node_Id := Empty)
339 if not Needs_BIP_Finalization_Master (Func_Id) then
344 Formal : constant Entity_Id :=
345 Build_In_Place_Formal (Func_Id, BIP_Finalization_Master);
346 Loc : constant Source_Ptr := Sloc (Func_Call);
349 Desig_Typ : Entity_Id;
352 -- If there is a finalization master actual, such as the implicit
353 -- finalization master of an enclosing build-in-place function,
354 -- then this must be added as an extra actual of the call.
356 if Present (Master_Exp) then
357 Actual := Master_Exp;
359 -- Case where the context does not require an actual master
361 elsif No (Ptr_Typ) then
362 Actual := Make_Null (Loc);
365 Desig_Typ := Directly_Designated_Type (Ptr_Typ);
367 -- Check for a library-level access type whose designated type has
368 -- supressed finalization. Such an access types lack a master.
369 -- Pass a null actual to the callee in order to signal a missing
372 if Is_Library_Level_Entity (Ptr_Typ)
373 and then Finalize_Storage_Only (Desig_Typ)
375 Actual := Make_Null (Loc);
377 -- Types in need of finalization actions
379 elsif Needs_Finalization (Desig_Typ) then
381 -- The general mechanism of creating finalization masters for
382 -- anonymous access types is disabled by default, otherwise
383 -- finalization masters will pop all over the place. Such types
384 -- use context-specific masters.
386 if Ekind (Ptr_Typ) = E_Anonymous_Access_Type
387 and then No (Finalization_Master (Ptr_Typ))
389 Build_Finalization_Master
391 Ins_Node => Associated_Node_For_Itype (Ptr_Typ),
392 Encl_Scope => Scope (Ptr_Typ));
395 -- Access-to-controlled types should always have a master
397 pragma Assert (Present (Finalization_Master (Ptr_Typ)));
400 Make_Attribute_Reference (Loc,
402 New_Reference_To (Finalization_Master (Ptr_Typ), Loc),
403 Attribute_Name => Name_Unrestricted_Access);
408 Actual := Make_Null (Loc);
412 Analyze_And_Resolve (Actual, Etype (Formal));
414 -- Build the parameter association for the new actual and add it to
415 -- the end of the function's actuals.
417 Add_Extra_Actual_To_Call (Func_Call, Formal, Actual);
419 end Add_Finalization_Master_Actual_To_Build_In_Place_Call;
421 ------------------------------
422 -- Add_Extra_Actual_To_Call --
423 ------------------------------
425 procedure Add_Extra_Actual_To_Call
426 (Subprogram_Call : Node_Id;
427 Extra_Formal : Entity_Id;
428 Extra_Actual : Node_Id)
430 Loc : constant Source_Ptr := Sloc (Subprogram_Call);
431 Param_Assoc : Node_Id;
435 Make_Parameter_Association (Loc,
436 Selector_Name => New_Occurrence_Of (Extra_Formal, Loc),
437 Explicit_Actual_Parameter => Extra_Actual);
439 Set_Parent (Param_Assoc, Subprogram_Call);
440 Set_Parent (Extra_Actual, Param_Assoc);
442 if Present (Parameter_Associations (Subprogram_Call)) then
443 if Nkind (Last (Parameter_Associations (Subprogram_Call))) =
444 N_Parameter_Association
447 -- Find last named actual, and append
452 L := First_Actual (Subprogram_Call);
453 while Present (L) loop
454 if No (Next_Actual (L)) then
455 Set_Next_Named_Actual (Parent (L), Extra_Actual);
463 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
466 Append (Param_Assoc, To => Parameter_Associations (Subprogram_Call));
469 Set_Parameter_Associations (Subprogram_Call, New_List (Param_Assoc));
470 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
472 end Add_Extra_Actual_To_Call;
474 ---------------------------------------------
475 -- Add_Task_Actuals_To_Build_In_Place_Call --
476 ---------------------------------------------
478 procedure Add_Task_Actuals_To_Build_In_Place_Call
479 (Function_Call : Node_Id;
480 Function_Id : Entity_Id;
481 Master_Actual : Node_Id)
483 Loc : constant Source_Ptr := Sloc (Function_Call);
484 Result_Subt : constant Entity_Id :=
485 Available_View (Etype (Function_Id));
487 Chain_Actual : Node_Id;
488 Chain_Formal : Node_Id;
489 Master_Formal : Node_Id;
492 -- No such extra parameters are needed if there are no tasks
494 if not Has_Task (Result_Subt) then
498 Actual := Master_Actual;
500 -- Use a dummy _master actual in case of No_Task_Hierarchy
502 if Restriction_Active (No_Task_Hierarchy) then
503 Actual := New_Occurrence_Of (RTE (RE_Library_Task_Level), Loc);
505 -- In the case where we use the master associated with an access type,
506 -- the actual is an entity and requires an explicit reference.
508 elsif Nkind (Actual) = N_Defining_Identifier then
509 Actual := New_Reference_To (Actual, Loc);
512 -- Locate the implicit master parameter in the called function
514 Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Task_Master);
515 Analyze_And_Resolve (Actual, Etype (Master_Formal));
517 -- Build the parameter association for the new actual and add it to the
518 -- end of the function's actuals.
520 Add_Extra_Actual_To_Call (Function_Call, Master_Formal, Actual);
522 -- Locate the implicit activation chain parameter in the called function
525 Build_In_Place_Formal (Function_Id, BIP_Activation_Chain);
527 -- Create the actual which is a pointer to the current activation chain
530 Make_Attribute_Reference (Loc,
531 Prefix => Make_Identifier (Loc, Name_uChain),
532 Attribute_Name => Name_Unrestricted_Access);
534 Analyze_And_Resolve (Chain_Actual, Etype (Chain_Formal));
536 -- Build the parameter association for the new actual and add it to the
537 -- end of the function's actuals.
539 Add_Extra_Actual_To_Call (Function_Call, Chain_Formal, Chain_Actual);
540 end Add_Task_Actuals_To_Build_In_Place_Call;
542 -----------------------
543 -- BIP_Formal_Suffix --
544 -----------------------
546 function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String is
549 when BIP_Alloc_Form =>
551 when BIP_Storage_Pool =>
552 return "BIPstoragepool";
553 when BIP_Finalization_Master =>
554 return "BIPfinalizationmaster";
555 when BIP_Task_Master =>
556 return "BIPtaskmaster";
557 when BIP_Activation_Chain =>
558 return "BIPactivationchain";
559 when BIP_Object_Access =>
562 end BIP_Formal_Suffix;
564 ---------------------------
565 -- Build_In_Place_Formal --
566 ---------------------------
568 function Build_In_Place_Formal
570 Kind : BIP_Formal_Kind) return Entity_Id
572 Formal_Name : constant Name_Id :=
574 (Chars (Func), BIP_Formal_Suffix (Kind));
575 Extra_Formal : Entity_Id := Extra_Formals (Func);
578 -- Maybe it would be better for each implicit formal of a build-in-place
579 -- function to have a flag or a Uint attribute to identify it. ???
581 -- The return type in the function declaration may have been a limited
582 -- view, and the extra formals for the function were not generated at
583 -- that point. At the point of call the full view must be available and
584 -- the extra formals can be created.
586 if No (Extra_Formal) then
587 Create_Extra_Formals (Func);
588 Extra_Formal := Extra_Formals (Func);
592 pragma Assert (Present (Extra_Formal));
593 exit when Chars (Extra_Formal) = Formal_Name;
595 Next_Formal_With_Extras (Extra_Formal);
599 end Build_In_Place_Formal;
601 --------------------------------
602 -- Check_Overriding_Operation --
603 --------------------------------
605 procedure Check_Overriding_Operation (Subp : Entity_Id) is
606 Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
607 Op_List : constant Elist_Id := Primitive_Operations (Typ);
613 if Is_Derived_Type (Typ)
614 and then not Is_Private_Type (Typ)
615 and then In_Open_Scopes (Scope (Etype (Typ)))
616 and then Is_Base_Type (Typ)
618 -- Subp overrides an inherited private operation if there is an
619 -- inherited operation with a different name than Subp (see
620 -- Derive_Subprogram) whose Alias is a hidden subprogram with the
621 -- same name as Subp.
623 Op_Elmt := First_Elmt (Op_List);
624 while Present (Op_Elmt) loop
625 Prim_Op := Node (Op_Elmt);
626 Par_Op := Alias (Prim_Op);
629 and then not Comes_From_Source (Prim_Op)
630 and then Chars (Prim_Op) /= Chars (Par_Op)
631 and then Chars (Par_Op) = Chars (Subp)
632 and then Is_Hidden (Par_Op)
633 and then Type_Conformant (Prim_Op, Subp)
635 Set_DT_Position (Subp, DT_Position (Prim_Op));
641 end Check_Overriding_Operation;
643 -------------------------------
644 -- Detect_Infinite_Recursion --
645 -------------------------------
647 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
648 Loc : constant Source_Ptr := Sloc (N);
650 Var_List : constant Elist_Id := New_Elmt_List;
651 -- List of globals referenced by body of procedure
653 Call_List : constant Elist_Id := New_Elmt_List;
654 -- List of recursive calls in body of procedure
656 Shad_List : constant Elist_Id := New_Elmt_List;
657 -- List of entity id's for entities created to capture the value of
658 -- referenced globals on entry to the procedure.
660 Scop : constant Uint := Scope_Depth (Spec);
661 -- This is used to record the scope depth of the current procedure, so
662 -- that we can identify global references.
664 Max_Vars : constant := 4;
665 -- Do not test more than four global variables
667 Count_Vars : Natural := 0;
668 -- Count variables found so far
680 function Process (Nod : Node_Id) return Traverse_Result;
681 -- Function to traverse the subprogram body (using Traverse_Func)
687 function Process (Nod : Node_Id) return Traverse_Result is
691 if Nkind (Nod) = N_Procedure_Call_Statement then
693 -- Case of one of the detected recursive calls
695 if Is_Entity_Name (Name (Nod))
696 and then Has_Recursive_Call (Entity (Name (Nod)))
697 and then Entity (Name (Nod)) = Spec
699 Append_Elmt (Nod, Call_List);
702 -- Any other procedure call may have side effects
708 -- A call to a pure function can always be ignored
710 elsif Nkind (Nod) = N_Function_Call
711 and then Is_Entity_Name (Name (Nod))
712 and then Is_Pure (Entity (Name (Nod)))
716 -- Case of an identifier reference
718 elsif Nkind (Nod) = N_Identifier then
721 -- If no entity, then ignore the reference
723 -- Not clear why this can happen. To investigate, remove this
724 -- test and look at the crash that occurs here in 3401-004 ???
729 -- Ignore entities with no Scope, again not clear how this
730 -- can happen, to investigate, look at 4108-008 ???
732 elsif No (Scope (Ent)) then
735 -- Ignore the reference if not to a more global object
737 elsif Scope_Depth (Scope (Ent)) >= Scop then
740 -- References to types, exceptions and constants are always OK
743 or else Ekind (Ent) = E_Exception
744 or else Ekind (Ent) = E_Constant
748 -- If other than a non-volatile scalar variable, we have some
749 -- kind of global reference (e.g. to a function) that we cannot
750 -- deal with so we forget the attempt.
752 elsif Ekind (Ent) /= E_Variable
753 or else not Is_Scalar_Type (Etype (Ent))
754 or else Treat_As_Volatile (Ent)
758 -- Otherwise we have a reference to a global scalar
761 -- Loop through global entities already detected
763 Elm := First_Elmt (Var_List);
765 -- If not detected before, record this new global reference
768 Count_Vars := Count_Vars + 1;
770 if Count_Vars <= Max_Vars then
771 Append_Elmt (Entity (Nod), Var_List);
778 -- If recorded before, ignore
780 elsif Node (Elm) = Entity (Nod) then
783 -- Otherwise keep looking
793 -- For all other node kinds, recursively visit syntactic children
800 function Traverse_Body is new Traverse_Func (Process);
802 -- Start of processing for Detect_Infinite_Recursion
805 -- Do not attempt detection in No_Implicit_Conditional mode, since we
806 -- won't be able to generate the code to handle the recursion in any
809 if Restriction_Active (No_Implicit_Conditionals) then
813 -- Otherwise do traversal and quit if we get abandon signal
815 if Traverse_Body (N) = Abandon then
818 -- We must have a call, since Has_Recursive_Call was set. If not just
819 -- ignore (this is only an error check, so if we have a funny situation,
820 -- due to bugs or errors, we do not want to bomb!)
822 elsif Is_Empty_Elmt_List (Call_List) then
826 -- Here is the case where we detect recursion at compile time
828 -- Push our current scope for analyzing the declarations and code that
829 -- we will insert for the checking.
833 -- This loop builds temporary variables for each of the referenced
834 -- globals, so that at the end of the loop the list Shad_List contains
835 -- these temporaries in one-to-one correspondence with the elements in
839 Elm := First_Elmt (Var_List);
840 while Present (Elm) loop
842 Ent := Make_Temporary (Loc, 'S');
843 Append_Elmt (Ent, Shad_List);
845 -- Insert a declaration for this temporary at the start of the
846 -- declarations for the procedure. The temporaries are declared as
847 -- constant objects initialized to the current values of the
848 -- corresponding temporaries.
851 Make_Object_Declaration (Loc,
852 Defining_Identifier => Ent,
853 Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
854 Constant_Present => True,
855 Expression => New_Occurrence_Of (Var, Loc));
858 Prepend (Decl, Declarations (N));
860 Insert_After (Last, Decl);
868 -- Loop through calls
870 Call := First_Elmt (Call_List);
871 while Present (Call) loop
873 -- Build a predicate expression of the form
876 -- and then global1 = temp1
877 -- and then global2 = temp2
880 -- This predicate determines if any of the global values
881 -- referenced by the procedure have changed since the
882 -- current call, if not an infinite recursion is assured.
884 Test := New_Occurrence_Of (Standard_True, Loc);
886 Elm1 := First_Elmt (Var_List);
887 Elm2 := First_Elmt (Shad_List);
888 while Present (Elm1) loop
894 Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
895 Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
901 -- Now we replace the call with the sequence
903 -- if no-changes (see above) then
904 -- raise Storage_Error;
909 Rewrite (Node (Call),
910 Make_If_Statement (Loc,
912 Then_Statements => New_List (
913 Make_Raise_Storage_Error (Loc,
914 Reason => SE_Infinite_Recursion)),
916 Else_Statements => New_List (
917 Relocate_Node (Node (Call)))));
919 Analyze (Node (Call));
924 -- Remove temporary scope stack entry used for analysis
927 end Detect_Infinite_Recursion;
933 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id) is
934 Loc : constant Source_Ptr := Sloc (N);
939 E_Formal : Entity_Id;
941 procedure Add_Call_By_Copy_Code;
942 -- For cases where the parameter must be passed by copy, this routine
943 -- generates a temporary variable into which the actual is copied and
944 -- then passes this as the parameter. For an OUT or IN OUT parameter,
945 -- an assignment is also generated to copy the result back. The call
946 -- also takes care of any constraint checks required for the type
947 -- conversion case (on both the way in and the way out).
949 procedure Add_Simple_Call_By_Copy_Code;
950 -- This is similar to the above, but is used in cases where we know
951 -- that all that is needed is to simply create a temporary and copy
952 -- the value in and out of the temporary.
954 procedure Check_Fortran_Logical;
955 -- A value of type Logical that is passed through a formal parameter
956 -- must be normalized because .TRUE. usually does not have the same
957 -- representation as True. We assume that .FALSE. = False = 0.
958 -- What about functions that return a logical type ???
960 function Is_Legal_Copy return Boolean;
961 -- Check that an actual can be copied before generating the temporary
962 -- to be used in the call. If the actual is of a by_reference type then
963 -- the program is illegal (this can only happen in the presence of
964 -- rep. clauses that force an incorrect alignment). If the formal is
965 -- a by_reference parameter imposed by a DEC pragma, emit a warning to
966 -- the effect that this might lead to unaligned arguments.
968 function Make_Var (Actual : Node_Id) return Entity_Id;
969 -- Returns an entity that refers to the given actual parameter,
970 -- Actual (not including any type conversion). If Actual is an
971 -- entity name, then this entity is returned unchanged, otherwise
972 -- a renaming is created to provide an entity for the actual.
974 procedure Reset_Packed_Prefix;
975 -- The expansion of a packed array component reference is delayed in
976 -- the context of a call. Now we need to complete the expansion, so we
977 -- unmark the analyzed bits in all prefixes.
979 ---------------------------
980 -- Add_Call_By_Copy_Code --
981 ---------------------------
983 procedure Add_Call_By_Copy_Code is
989 F_Typ : constant Entity_Id := Etype (Formal);
994 if not Is_Legal_Copy then
998 Temp := Make_Temporary (Loc, 'T', Actual);
1000 -- Use formal type for temp, unless formal type is an unconstrained
1001 -- array, in which case we don't have to worry about bounds checks,
1002 -- and we use the actual type, since that has appropriate bounds.
1004 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
1005 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1007 Indic := New_Occurrence_Of (Etype (Formal), Loc);
1010 if Nkind (Actual) = N_Type_Conversion then
1011 V_Typ := Etype (Expression (Actual));
1013 -- If the formal is an (in-)out parameter, capture the name
1014 -- of the variable in order to build the post-call assignment.
1016 Var := Make_Var (Expression (Actual));
1018 Crep := not Same_Representation
1019 (F_Typ, Etype (Expression (Actual)));
1022 V_Typ := Etype (Actual);
1023 Var := Make_Var (Actual);
1027 -- Setup initialization for case of in out parameter, or an out
1028 -- parameter where the formal is an unconstrained array (in the
1029 -- latter case, we have to pass in an object with bounds).
1031 -- If this is an out parameter, the initial copy is wasteful, so as
1032 -- an optimization for the one-dimensional case we extract the
1033 -- bounds of the actual and build an uninitialized temporary of the
1036 if Ekind (Formal) = E_In_Out_Parameter
1037 or else (Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ))
1039 if Nkind (Actual) = N_Type_Conversion then
1040 if Conversion_OK (Actual) then
1041 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1043 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1046 elsif Ekind (Formal) = E_Out_Parameter
1047 and then Is_Array_Type (F_Typ)
1048 and then Number_Dimensions (F_Typ) = 1
1049 and then not Has_Non_Null_Base_Init_Proc (F_Typ)
1051 -- Actual is a one-dimensional array or slice, and the type
1052 -- requires no initialization. Create a temporary of the
1053 -- right size, but do not copy actual into it (optimization).
1057 Make_Subtype_Indication (Loc,
1059 New_Occurrence_Of (F_Typ, Loc),
1061 Make_Index_Or_Discriminant_Constraint (Loc,
1062 Constraints => New_List (
1065 Make_Attribute_Reference (Loc,
1066 Prefix => New_Occurrence_Of (Var, Loc),
1067 Attribute_Name => Name_First),
1069 Make_Attribute_Reference (Loc,
1070 Prefix => New_Occurrence_Of (Var, Loc),
1071 Attribute_Name => Name_Last)))));
1074 Init := New_Occurrence_Of (Var, Loc);
1077 -- An initialization is created for packed conversions as
1078 -- actuals for out parameters to enable Make_Object_Declaration
1079 -- to determine the proper subtype for N_Node. Note that this
1080 -- is wasteful because the extra copying on the call side is
1081 -- not required for such out parameters. ???
1083 elsif Ekind (Formal) = E_Out_Parameter
1084 and then Nkind (Actual) = N_Type_Conversion
1085 and then (Is_Bit_Packed_Array (F_Typ)
1087 Is_Bit_Packed_Array (Etype (Expression (Actual))))
1089 if Conversion_OK (Actual) then
1090 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1092 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1095 elsif Ekind (Formal) = E_In_Parameter then
1097 -- Handle the case in which the actual is a type conversion
1099 if Nkind (Actual) = N_Type_Conversion then
1100 if Conversion_OK (Actual) then
1101 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1103 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1106 Init := New_Occurrence_Of (Var, Loc);
1114 Make_Object_Declaration (Loc,
1115 Defining_Identifier => Temp,
1116 Object_Definition => Indic,
1117 Expression => Init);
1118 Set_Assignment_OK (N_Node);
1119 Insert_Action (N, N_Node);
1121 -- Now, normally the deal here is that we use the defining
1122 -- identifier created by that object declaration. There is
1123 -- one exception to this. In the change of representation case
1124 -- the above declaration will end up looking like:
1126 -- temp : type := identifier;
1128 -- And in this case we might as well use the identifier directly
1129 -- and eliminate the temporary. Note that the analysis of the
1130 -- declaration was not a waste of time in that case, since it is
1131 -- what generated the necessary change of representation code. If
1132 -- the change of representation introduced additional code, as in
1133 -- a fixed-integer conversion, the expression is not an identifier
1134 -- and must be kept.
1137 and then Present (Expression (N_Node))
1138 and then Is_Entity_Name (Expression (N_Node))
1140 Temp := Entity (Expression (N_Node));
1141 Rewrite (N_Node, Make_Null_Statement (Loc));
1144 -- For IN parameter, all we do is to replace the actual
1146 if Ekind (Formal) = E_In_Parameter then
1147 Rewrite (Actual, New_Reference_To (Temp, Loc));
1150 -- Processing for OUT or IN OUT parameter
1153 -- Kill current value indications for the temporary variable we
1154 -- created, since we just passed it as an OUT parameter.
1156 Kill_Current_Values (Temp);
1157 Set_Is_Known_Valid (Temp, False);
1159 -- If type conversion, use reverse conversion on exit
1161 if Nkind (Actual) = N_Type_Conversion then
1162 if Conversion_OK (Actual) then
1163 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1165 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1168 Expr := New_Occurrence_Of (Temp, Loc);
1171 Rewrite (Actual, New_Reference_To (Temp, Loc));
1174 -- If the actual is a conversion of a packed reference, it may
1175 -- already have been expanded by Remove_Side_Effects, and the
1176 -- resulting variable is a temporary which does not designate
1177 -- the proper out-parameter, which may not be addressable. In
1178 -- that case, generate an assignment to the original expression
1179 -- (before expansion of the packed reference) so that the proper
1180 -- expansion of assignment to a packed component can take place.
1187 if Is_Renaming_Of_Object (Var)
1188 and then Nkind (Renamed_Object (Var)) = N_Selected_Component
1189 and then Is_Entity_Name (Prefix (Renamed_Object (Var)))
1190 and then Nkind (Original_Node (Prefix (Renamed_Object (Var))))
1191 = N_Indexed_Component
1193 Has_Non_Standard_Rep (Etype (Prefix (Renamed_Object (Var))))
1195 Obj := Renamed_Object (Var);
1197 Make_Selected_Component (Loc,
1199 New_Copy_Tree (Original_Node (Prefix (Obj))),
1200 Selector_Name => New_Copy (Selector_Name (Obj)));
1201 Reset_Analyzed_Flags (Lhs);
1204 Lhs := New_Occurrence_Of (Var, Loc);
1207 Set_Assignment_OK (Lhs);
1209 if Is_Access_Type (E_Formal)
1210 and then Is_Entity_Name (Lhs)
1212 Present (Effective_Extra_Accessibility (Entity (Lhs)))
1214 -- Copyback target is an Ada 2012 stand-alone object
1215 -- of an anonymous access type
1217 pragma Assert (Ada_Version >= Ada_2012);
1219 if Type_Access_Level (E_Formal) >
1220 Object_Access_Level (Lhs)
1222 Append_To (Post_Call,
1223 Make_Raise_Program_Error (Loc,
1224 Reason => PE_Accessibility_Check_Failed));
1227 Append_To (Post_Call,
1228 Make_Assignment_Statement (Loc,
1230 Expression => Expr));
1232 -- We would like to somehow suppress generation of the
1233 -- extra_accessibility assignment generated by the expansion
1234 -- of the above assignment statement. It's not a correctness
1235 -- issue because the following assignment renders it dead,
1236 -- but generating back-to-back assignments to the same
1237 -- target is undesirable. ???
1239 Append_To (Post_Call,
1240 Make_Assignment_Statement (Loc,
1241 Name => New_Occurrence_Of (
1242 Effective_Extra_Accessibility (Entity (Lhs)), Loc),
1243 Expression => Make_Integer_Literal (Loc,
1244 Type_Access_Level (E_Formal))));
1247 Append_To (Post_Call,
1248 Make_Assignment_Statement (Loc,
1250 Expression => Expr));
1254 end Add_Call_By_Copy_Code;
1256 ----------------------------------
1257 -- Add_Simple_Call_By_Copy_Code --
1258 ----------------------------------
1260 procedure Add_Simple_Call_By_Copy_Code is
1268 F_Typ : constant Entity_Id := Etype (Formal);
1271 if not Is_Legal_Copy then
1275 -- Use formal type for temp, unless formal type is an unconstrained
1276 -- array, in which case we don't have to worry about bounds checks,
1277 -- and we use the actual type, since that has appropriate bounds.
1279 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
1280 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1282 Indic := New_Occurrence_Of (Etype (Formal), Loc);
1285 -- Prepare to generate code
1287 Reset_Packed_Prefix;
1289 Temp := Make_Temporary (Loc, 'T', Actual);
1290 Incod := Relocate_Node (Actual);
1291 Outcod := New_Copy_Tree (Incod);
1293 -- Generate declaration of temporary variable, initializing it
1294 -- with the input parameter unless we have an OUT formal or
1295 -- this is an initialization call.
1297 -- If the formal is an out parameter with discriminants, the
1298 -- discriminants must be captured even if the rest of the object
1299 -- is in principle uninitialized, because the discriminants may
1300 -- be read by the called subprogram.
1302 if Ekind (Formal) = E_Out_Parameter then
1305 if Has_Discriminants (Etype (Formal)) then
1306 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1309 elsif Inside_Init_Proc then
1311 -- Could use a comment here to match comment below ???
1313 if Nkind (Actual) /= N_Selected_Component
1315 not Has_Discriminant_Dependent_Constraint
1316 (Entity (Selector_Name (Actual)))
1320 -- Otherwise, keep the component in order to generate the proper
1321 -- actual subtype, that depends on enclosing discriminants.
1329 Make_Object_Declaration (Loc,
1330 Defining_Identifier => Temp,
1331 Object_Definition => Indic,
1332 Expression => Incod);
1337 -- If the call is to initialize a component of a composite type,
1338 -- and the component does not depend on discriminants, use the
1339 -- actual type of the component. This is required in case the
1340 -- component is constrained, because in general the formal of the
1341 -- initialization procedure will be unconstrained. Note that if
1342 -- the component being initialized is constrained by an enclosing
1343 -- discriminant, the presence of the initialization in the
1344 -- declaration will generate an expression for the actual subtype.
1346 Set_No_Initialization (Decl);
1347 Set_Object_Definition (Decl,
1348 New_Occurrence_Of (Etype (Actual), Loc));
1351 Insert_Action (N, Decl);
1353 -- The actual is simply a reference to the temporary
1355 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
1357 -- Generate copy out if OUT or IN OUT parameter
1359 if Ekind (Formal) /= E_In_Parameter then
1361 Rhs := New_Occurrence_Of (Temp, Loc);
1363 -- Deal with conversion
1365 if Nkind (Lhs) = N_Type_Conversion then
1366 Lhs := Expression (Lhs);
1367 Rhs := Convert_To (Etype (Actual), Rhs);
1370 Append_To (Post_Call,
1371 Make_Assignment_Statement (Loc,
1373 Expression => Rhs));
1374 Set_Assignment_OK (Name (Last (Post_Call)));
1376 end Add_Simple_Call_By_Copy_Code;
1378 ---------------------------
1379 -- Check_Fortran_Logical --
1380 ---------------------------
1382 procedure Check_Fortran_Logical is
1383 Logical : constant Entity_Id := Etype (Formal);
1386 -- Note: this is very incomplete, e.g. it does not handle arrays
1387 -- of logical values. This is really not the right approach at all???)
1390 if Convention (Subp) = Convention_Fortran
1391 and then Root_Type (Etype (Formal)) = Standard_Boolean
1392 and then Ekind (Formal) /= E_In_Parameter
1394 Var := Make_Var (Actual);
1395 Append_To (Post_Call,
1396 Make_Assignment_Statement (Loc,
1397 Name => New_Occurrence_Of (Var, Loc),
1399 Unchecked_Convert_To (
1402 Left_Opnd => New_Occurrence_Of (Var, Loc),
1404 Unchecked_Convert_To (
1406 New_Occurrence_Of (Standard_False, Loc))))));
1408 end Check_Fortran_Logical;
1414 function Is_Legal_Copy return Boolean is
1416 -- An attempt to copy a value of such a type can only occur if
1417 -- representation clauses give the actual a misaligned address.
1419 if Is_By_Reference_Type (Etype (Formal)) then
1421 -- If the front-end does not perform full type layout, the actual
1422 -- may in fact be properly aligned but there is not enough front-
1423 -- end information to determine this. In that case gigi will emit
1424 -- an error if a copy is not legal, or generate the proper code.
1425 -- For other backends we report the error now.
1427 -- Seems wrong to be issuing an error in the expander, since it
1428 -- will be missed in -gnatc mode ???
1430 if Frontend_Layout_On_Target then
1432 ("misaligned actual cannot be passed by reference", Actual);
1437 -- For users of Starlet, we assume that the specification of by-
1438 -- reference mechanism is mandatory. This may lead to unaligned
1439 -- objects but at least for DEC legacy code it is known to work.
1440 -- The warning will alert users of this code that a problem may
1443 elsif Mechanism (Formal) = By_Reference
1444 and then Is_Valued_Procedure (Scope (Formal))
1447 ("by_reference actual may be misaligned?", Actual);
1459 function Make_Var (Actual : Node_Id) return Entity_Id is
1463 if Is_Entity_Name (Actual) then
1464 return Entity (Actual);
1467 Var := Make_Temporary (Loc, 'T', Actual);
1470 Make_Object_Renaming_Declaration (Loc,
1471 Defining_Identifier => Var,
1473 New_Occurrence_Of (Etype (Actual), Loc),
1474 Name => Relocate_Node (Actual));
1476 Insert_Action (N, N_Node);
1481 -------------------------
1482 -- Reset_Packed_Prefix --
1483 -------------------------
1485 procedure Reset_Packed_Prefix is
1486 Pfx : Node_Id := Actual;
1489 Set_Analyzed (Pfx, False);
1491 not Nkind_In (Pfx, N_Selected_Component, N_Indexed_Component);
1492 Pfx := Prefix (Pfx);
1494 end Reset_Packed_Prefix;
1496 -- Start of processing for Expand_Actuals
1499 Post_Call := New_List;
1501 Formal := First_Formal (Subp);
1502 Actual := First_Actual (N);
1503 while Present (Formal) loop
1504 E_Formal := Etype (Formal);
1506 if Is_Scalar_Type (E_Formal)
1507 or else Nkind (Actual) = N_Slice
1509 Check_Fortran_Logical;
1513 elsif Ekind (Formal) /= E_Out_Parameter then
1515 -- The unusual case of the current instance of a protected type
1516 -- requires special handling. This can only occur in the context
1517 -- of a call within the body of a protected operation.
1519 if Is_Entity_Name (Actual)
1520 and then Ekind (Entity (Actual)) = E_Protected_Type
1521 and then In_Open_Scopes (Entity (Actual))
1523 if Scope (Subp) /= Entity (Actual) then
1524 Error_Msg_N ("operation outside protected type may not "
1525 & "call back its protected operations?", Actual);
1529 Expand_Protected_Object_Reference (N, Entity (Actual)));
1532 -- Ada 2005 (AI-318-02): If the actual parameter is a call to a
1533 -- build-in-place function, then a temporary return object needs
1534 -- to be created and access to it must be passed to the function.
1535 -- Currently we limit such functions to those with inherently
1536 -- limited result subtypes, but eventually we plan to expand the
1537 -- functions that are treated as build-in-place to include other
1538 -- composite result types.
1540 if Is_Build_In_Place_Function_Call (Actual) then
1541 Make_Build_In_Place_Call_In_Anonymous_Context (Actual);
1544 Apply_Constraint_Check (Actual, E_Formal);
1546 -- Out parameter case. No constraint checks on access type
1549 elsif Is_Access_Type (E_Formal) then
1554 elsif Has_Discriminants (Base_Type (E_Formal))
1555 or else Has_Non_Null_Base_Init_Proc (E_Formal)
1557 Apply_Constraint_Check (Actual, E_Formal);
1562 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
1565 -- Processing for IN-OUT and OUT parameters
1567 if Ekind (Formal) /= E_In_Parameter then
1569 -- For type conversions of arrays, apply length/range checks
1571 if Is_Array_Type (E_Formal)
1572 and then Nkind (Actual) = N_Type_Conversion
1574 if Is_Constrained (E_Formal) then
1575 Apply_Length_Check (Expression (Actual), E_Formal);
1577 Apply_Range_Check (Expression (Actual), E_Formal);
1581 -- If argument is a type conversion for a type that is passed
1582 -- by copy, then we must pass the parameter by copy.
1584 if Nkind (Actual) = N_Type_Conversion
1586 (Is_Numeric_Type (E_Formal)
1587 or else Is_Access_Type (E_Formal)
1588 or else Is_Enumeration_Type (E_Formal)
1589 or else Is_Bit_Packed_Array (Etype (Formal))
1590 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
1592 -- Also pass by copy if change of representation
1594 or else not Same_Representation
1596 Etype (Expression (Actual))))
1598 Add_Call_By_Copy_Code;
1600 -- References to components of bit packed arrays are expanded
1601 -- at this point, rather than at the point of analysis of the
1602 -- actuals, to handle the expansion of the assignment to
1603 -- [in] out parameters.
1605 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1606 Add_Simple_Call_By_Copy_Code;
1608 -- If a non-scalar actual is possibly bit-aligned, we need a copy
1609 -- because the back-end cannot cope with such objects. In other
1610 -- cases where alignment forces a copy, the back-end generates
1611 -- it properly. It should not be generated unconditionally in the
1612 -- front-end because it does not know precisely the alignment
1613 -- requirements of the target, and makes too conservative an
1614 -- estimate, leading to superfluous copies or spurious errors
1615 -- on by-reference parameters.
1617 elsif Nkind (Actual) = N_Selected_Component
1619 Component_May_Be_Bit_Aligned (Entity (Selector_Name (Actual)))
1620 and then not Represented_As_Scalar (Etype (Formal))
1622 Add_Simple_Call_By_Copy_Code;
1624 -- References to slices of bit packed arrays are expanded
1626 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1627 Add_Call_By_Copy_Code;
1629 -- References to possibly unaligned slices of arrays are expanded
1631 elsif Is_Possibly_Unaligned_Slice (Actual) then
1632 Add_Call_By_Copy_Code;
1634 -- Deal with access types where the actual subtype and the
1635 -- formal subtype are not the same, requiring a check.
1637 -- It is necessary to exclude tagged types because of "downward
1638 -- conversion" errors.
1640 elsif Is_Access_Type (E_Formal)
1641 and then not Same_Type (E_Formal, Etype (Actual))
1642 and then not Is_Tagged_Type (Designated_Type (E_Formal))
1644 Add_Call_By_Copy_Code;
1646 -- If the actual is not a scalar and is marked for volatile
1647 -- treatment, whereas the formal is not volatile, then pass
1648 -- by copy unless it is a by-reference type.
1650 -- Note: we use Is_Volatile here rather than Treat_As_Volatile,
1651 -- because this is the enforcement of a language rule that applies
1652 -- only to "real" volatile variables, not e.g. to the address
1653 -- clause overlay case.
1655 elsif Is_Entity_Name (Actual)
1656 and then Is_Volatile (Entity (Actual))
1657 and then not Is_By_Reference_Type (Etype (Actual))
1658 and then not Is_Scalar_Type (Etype (Entity (Actual)))
1659 and then not Is_Volatile (E_Formal)
1661 Add_Call_By_Copy_Code;
1663 elsif Nkind (Actual) = N_Indexed_Component
1664 and then Is_Entity_Name (Prefix (Actual))
1665 and then Has_Volatile_Components (Entity (Prefix (Actual)))
1667 Add_Call_By_Copy_Code;
1669 -- Add call-by-copy code for the case of scalar out parameters
1670 -- when it is not known at compile time that the subtype of the
1671 -- formal is a subrange of the subtype of the actual (or vice
1672 -- versa for in out parameters), in order to get range checks
1673 -- on such actuals. (Maybe this case should be handled earlier
1674 -- in the if statement???)
1676 elsif Is_Scalar_Type (E_Formal)
1678 (not In_Subrange_Of (E_Formal, Etype (Actual))
1680 (Ekind (Formal) = E_In_Out_Parameter
1681 and then not In_Subrange_Of (Etype (Actual), E_Formal)))
1683 -- Perhaps the setting back to False should be done within
1684 -- Add_Call_By_Copy_Code, since it could get set on other
1685 -- cases occurring above???
1687 if Do_Range_Check (Actual) then
1688 Set_Do_Range_Check (Actual, False);
1691 Add_Call_By_Copy_Code;
1694 -- Processing for IN parameters
1697 -- For IN parameters is in the packed array case, we expand an
1698 -- indexed component (the circuit in Exp_Ch4 deliberately left
1699 -- indexed components appearing as actuals untouched, so that
1700 -- the special processing above for the OUT and IN OUT cases
1701 -- could be performed. We could make the test in Exp_Ch4 more
1702 -- complex and have it detect the parameter mode, but it is
1703 -- easier simply to handle all cases here.)
1705 if Nkind (Actual) = N_Indexed_Component
1706 and then Is_Packed (Etype (Prefix (Actual)))
1708 Reset_Packed_Prefix;
1709 Expand_Packed_Element_Reference (Actual);
1711 -- If we have a reference to a bit packed array, we copy it, since
1712 -- the actual must be byte aligned.
1714 -- Is this really necessary in all cases???
1716 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1717 Add_Simple_Call_By_Copy_Code;
1719 -- If a non-scalar actual is possibly unaligned, we need a copy
1721 elsif Is_Possibly_Unaligned_Object (Actual)
1722 and then not Represented_As_Scalar (Etype (Formal))
1724 Add_Simple_Call_By_Copy_Code;
1726 -- Similarly, we have to expand slices of packed arrays here
1727 -- because the result must be byte aligned.
1729 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1730 Add_Call_By_Copy_Code;
1732 -- Only processing remaining is to pass by copy if this is a
1733 -- reference to a possibly unaligned slice, since the caller
1734 -- expects an appropriately aligned argument.
1736 elsif Is_Possibly_Unaligned_Slice (Actual) then
1737 Add_Call_By_Copy_Code;
1739 -- An unusual case: a current instance of an enclosing task can be
1740 -- an actual, and must be replaced by a reference to self.
1742 elsif Is_Entity_Name (Actual)
1743 and then Is_Task_Type (Entity (Actual))
1745 if In_Open_Scopes (Entity (Actual)) then
1747 (Make_Function_Call (Loc,
1748 Name => New_Reference_To (RTE (RE_Self), Loc))));
1751 -- A task type cannot otherwise appear as an actual
1754 raise Program_Error;
1759 Next_Formal (Formal);
1760 Next_Actual (Actual);
1763 -- Find right place to put post call stuff if it is present
1765 if not Is_Empty_List (Post_Call) then
1767 -- Cases where the call is not a member of a statement list
1769 if not Is_List_Member (N) then
1771 P : Node_Id := Parent (N);
1774 -- In Ada 2012 the call may be a function call in an expression
1775 -- (since OUT and IN OUT parameters are now allowed for such
1776 -- calls. The write-back of (in)-out parameters is handled
1777 -- by the back-end, but the constraint checks generated when
1778 -- subtypes of formal and actual don't match must be inserted
1779 -- in the form of assignments, at the nearest point after the
1780 -- declaration or statement that contains the call.
1782 if Ada_Version >= Ada_2012
1783 and then Nkind (N) = N_Function_Call
1785 while Nkind (P) not in N_Declaration
1787 Nkind (P) not in N_Statement_Other_Than_Procedure_Call
1792 Insert_Actions_After (P, Post_Call);
1794 -- If not the special Ada 2012 case of a function call, then
1795 -- we must have the triggering statement of a triggering
1796 -- alternative or an entry call alternative, and we can add
1797 -- the post call stuff to the corresponding statement list.
1800 pragma Assert (Nkind_In (P, N_Triggering_Alternative,
1801 N_Entry_Call_Alternative));
1803 if Is_Non_Empty_List (Statements (P)) then
1804 Insert_List_Before_And_Analyze
1805 (First (Statements (P)), Post_Call);
1807 Set_Statements (P, Post_Call);
1813 -- Otherwise, normal case where N is in a statement sequence,
1814 -- just put the post-call stuff after the call statement.
1817 Insert_Actions_After (N, Post_Call);
1821 -- The call node itself is re-analyzed in Expand_Call
1829 -- This procedure handles expansion of function calls and procedure call
1830 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1831 -- Expand_N_Procedure_Call_Statement). Processing for calls includes:
1833 -- Replace call to Raise_Exception by Raise_Exception_Always if possible
1834 -- Provide values of actuals for all formals in Extra_Formals list
1835 -- Replace "call" to enumeration literal function by literal itself
1836 -- Rewrite call to predefined operator as operator
1837 -- Replace actuals to in-out parameters that are numeric conversions,
1838 -- with explicit assignment to temporaries before and after the call.
1839 -- Remove optional actuals if First_Optional_Parameter specified.
1841 -- Note that the list of actuals has been filled with default expressions
1842 -- during semantic analysis of the call. Only the extra actuals required
1843 -- for the 'Constrained attribute and for accessibility checks are added
1846 procedure Expand_Call (N : Node_Id) is
1847 Loc : constant Source_Ptr := Sloc (N);
1848 Call_Node : Node_Id := N;
1849 Extra_Actuals : List_Id := No_List;
1850 Prev : Node_Id := Empty;
1852 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1853 -- Adds one entry to the end of the actual parameter list. Used for
1854 -- default parameters and for extra actuals (for Extra_Formals). The
1855 -- argument is an N_Parameter_Association node.
1857 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1858 -- Adds an extra actual to the list of extra actuals. Expr is the
1859 -- expression for the value of the actual, EF is the entity for the
1862 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1863 -- Within an instance, a type derived from a non-tagged formal derived
1864 -- type inherits from the original parent, not from the actual. The
1865 -- current derivation mechanism has the derived type inherit from the
1866 -- actual, which is only correct outside of the instance. If the
1867 -- subprogram is inherited, we test for this particular case through a
1868 -- convoluted tree traversal before setting the proper subprogram to be
1871 function Is_Direct_Deep_Call (Subp : Entity_Id) return Boolean;
1872 -- Determine if Subp denotes a non-dispatching call to a Deep routine
1874 function New_Value (From : Node_Id) return Node_Id;
1875 -- From is the original Expression. New_Value is equivalent to a call
1876 -- to Duplicate_Subexpr with an explicit dereference when From is an
1877 -- access parameter.
1879 --------------------------
1880 -- Add_Actual_Parameter --
1881 --------------------------
1883 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1884 Actual_Expr : constant Node_Id :=
1885 Explicit_Actual_Parameter (Insert_Param);
1888 -- Case of insertion is first named actual
1890 if No (Prev) or else
1891 Nkind (Parent (Prev)) /= N_Parameter_Association
1893 Set_Next_Named_Actual
1894 (Insert_Param, First_Named_Actual (Call_Node));
1895 Set_First_Named_Actual (Call_Node, Actual_Expr);
1898 if No (Parameter_Associations (Call_Node)) then
1899 Set_Parameter_Associations (Call_Node, New_List);
1902 Append (Insert_Param, Parameter_Associations (Call_Node));
1905 Insert_After (Prev, Insert_Param);
1908 -- Case of insertion is not first named actual
1911 Set_Next_Named_Actual
1912 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1913 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1914 Append (Insert_Param, Parameter_Associations (Call_Node));
1917 Prev := Actual_Expr;
1918 end Add_Actual_Parameter;
1920 ----------------------
1921 -- Add_Extra_Actual --
1922 ----------------------
1924 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1925 Loc : constant Source_Ptr := Sloc (Expr);
1928 if Extra_Actuals = No_List then
1929 Extra_Actuals := New_List;
1930 Set_Parent (Extra_Actuals, Call_Node);
1933 Append_To (Extra_Actuals,
1934 Make_Parameter_Association (Loc,
1935 Selector_Name => Make_Identifier (Loc, Chars (EF)),
1936 Explicit_Actual_Parameter => Expr));
1938 Analyze_And_Resolve (Expr, Etype (EF));
1940 if Nkind (Call_Node) = N_Function_Call then
1941 Set_Is_Accessibility_Actual (Parent (Expr));
1943 end Add_Extra_Actual;
1945 ---------------------------
1946 -- Inherited_From_Formal --
1947 ---------------------------
1949 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1951 Gen_Par : Entity_Id;
1952 Gen_Prim : Elist_Id;
1957 -- If the operation is inherited, it is attached to the corresponding
1958 -- type derivation. If the parent in the derivation is a generic
1959 -- actual, it is a subtype of the actual, and we have to recover the
1960 -- original derived type declaration to find the proper parent.
1962 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1963 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1964 or else Nkind (Type_Definition (Original_Node (Parent (S)))) /=
1965 N_Derived_Type_Definition
1966 or else not In_Instance
1973 (Type_Definition (Original_Node (Parent (S))));
1975 if Nkind (Indic) = N_Subtype_Indication then
1976 Par := Entity (Subtype_Mark (Indic));
1978 Par := Entity (Indic);
1982 if not Is_Generic_Actual_Type (Par)
1983 or else Is_Tagged_Type (Par)
1984 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1985 or else not In_Open_Scopes (Scope (Par))
1989 Gen_Par := Generic_Parent_Type (Parent (Par));
1992 -- If the actual has no generic parent type, the formal is not
1993 -- a formal derived type, so nothing to inherit.
1995 if No (Gen_Par) then
1999 -- If the generic parent type is still the generic type, this is a
2000 -- private formal, not a derived formal, and there are no operations
2001 -- inherited from the formal.
2003 if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
2007 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
2009 Elmt := First_Elmt (Gen_Prim);
2010 while Present (Elmt) loop
2011 if Chars (Node (Elmt)) = Chars (S) then
2017 F1 := First_Formal (S);
2018 F2 := First_Formal (Node (Elmt));
2020 and then Present (F2)
2022 if Etype (F1) = Etype (F2)
2023 or else Etype (F2) = Gen_Par
2029 exit; -- not the right subprogram
2041 raise Program_Error;
2042 end Inherited_From_Formal;
2044 -------------------------
2045 -- Is_Direct_Deep_Call --
2046 -------------------------
2048 function Is_Direct_Deep_Call (Subp : Entity_Id) return Boolean is
2050 if Is_TSS (Subp, TSS_Deep_Adjust)
2051 or else Is_TSS (Subp, TSS_Deep_Finalize)
2052 or else Is_TSS (Subp, TSS_Deep_Initialize)
2059 Actual := First (Parameter_Associations (N));
2060 Formal := First_Formal (Subp);
2061 while Present (Actual)
2062 and then Present (Formal)
2064 if Nkind (Actual) = N_Identifier
2065 and then Is_Controlling_Actual (Actual)
2066 and then Etype (Actual) = Etype (Formal)
2072 Next_Formal (Formal);
2078 end Is_Direct_Deep_Call;
2084 function New_Value (From : Node_Id) return Node_Id is
2085 Res : constant Node_Id := Duplicate_Subexpr (From);
2087 if Is_Access_Type (Etype (From)) then
2089 Make_Explicit_Dereference (Sloc (From),
2098 Curr_S : constant Entity_Id := Current_Scope;
2099 Remote : constant Boolean := Is_Remote_Call (Call_Node);
2102 Orig_Subp : Entity_Id := Empty;
2103 Param_Count : Natural := 0;
2104 Parent_Formal : Entity_Id;
2105 Parent_Subp : Entity_Id;
2109 Prev_Orig : Node_Id;
2110 -- Original node for an actual, which may have been rewritten. If the
2111 -- actual is a function call that has been transformed from a selected
2112 -- component, the original node is unanalyzed. Otherwise, it carries
2113 -- semantic information used to generate additional actuals.
2115 CW_Interface_Formals_Present : Boolean := False;
2117 -- Start of processing for Expand_Call
2120 -- Expand the procedure call if the first actual has a dimension and if
2121 -- the procedure is Put (Ada 2012).
2123 if Ada_Version >= Ada_2012
2124 and then Nkind (Call_Node) = N_Procedure_Call_Statement
2125 and then Present (Parameter_Associations (Call_Node))
2127 Expand_Put_Call_With_Dimension_Symbol (Call_Node);
2130 -- Remove the dimensions of every parameters in call
2132 Remove_Dimension_In_Call (N);
2134 -- Ignore if previous error
2136 if Nkind (Call_Node) in N_Has_Etype
2137 and then Etype (Call_Node) = Any_Type
2142 -- Call using access to subprogram with explicit dereference
2144 if Nkind (Name (Call_Node)) = N_Explicit_Dereference then
2145 Subp := Etype (Name (Call_Node));
2146 Parent_Subp := Empty;
2148 -- Case of call to simple entry, where the Name is a selected component
2149 -- whose prefix is the task, and whose selector name is the entry name
2151 elsif Nkind (Name (Call_Node)) = N_Selected_Component then
2152 Subp := Entity (Selector_Name (Name (Call_Node)));
2153 Parent_Subp := Empty;
2155 -- Case of call to member of entry family, where Name is an indexed
2156 -- component, with the prefix being a selected component giving the
2157 -- task and entry family name, and the index being the entry index.
2159 elsif Nkind (Name (Call_Node)) = N_Indexed_Component then
2160 Subp := Entity (Selector_Name (Prefix (Name (Call_Node))));
2161 Parent_Subp := Empty;
2166 Subp := Entity (Name (Call_Node));
2167 Parent_Subp := Alias (Subp);
2169 -- Replace call to Raise_Exception by call to Raise_Exception_Always
2170 -- if we can tell that the first parameter cannot possibly be null.
2171 -- This improves efficiency by avoiding a run-time test.
2173 -- We do not do this if Raise_Exception_Always does not exist, which
2174 -- can happen in configurable run time profiles which provide only a
2177 if Is_RTE (Subp, RE_Raise_Exception)
2178 and then RTE_Available (RE_Raise_Exception_Always)
2181 FA : constant Node_Id :=
2182 Original_Node (First_Actual (Call_Node));
2185 -- The case we catch is where the first argument is obtained
2186 -- using the Identity attribute (which must always be
2189 if Nkind (FA) = N_Attribute_Reference
2190 and then Attribute_Name (FA) = Name_Identity
2192 Subp := RTE (RE_Raise_Exception_Always);
2193 Set_Name (Call_Node, New_Occurrence_Of (Subp, Loc));
2198 if Ekind (Subp) = E_Entry then
2199 Parent_Subp := Empty;
2203 -- Detect the following code in System.Finalization_Masters only on
2204 -- .NET/JVM targets:
2206 -- procedure Finalize (Master : in out Finalization_Master) is
2210 -- Finalize (Curr_Ptr.all);
2212 -- Since .NET/JVM compilers lack address arithmetic and Deep_Finalize
2213 -- cannot be named in library or user code, the compiler has to install
2214 -- a kludge and transform the call to Finalize into Deep_Finalize.
2216 if VM_Target /= No_VM
2217 and then Chars (Subp) = Name_Finalize
2218 and then Ekind (Curr_S) = E_Block
2219 and then Ekind (Scope (Curr_S)) = E_Procedure
2220 and then Chars (Scope (Curr_S)) = Name_Finalize
2221 and then Etype (First_Formal (Scope (Curr_S))) =
2222 RTE (RE_Finalization_Master)
2225 Deep_Fin : constant Entity_Id :=
2226 Find_Prim_Op (RTE (RE_Root_Controlled),
2229 -- Since Root_Controlled is a tagged type, the compiler should
2230 -- always generate Deep_Finalize for it.
2232 pragma Assert (Present (Deep_Fin));
2235 -- Deep_Finalize (Curr_Ptr.all);
2238 Make_Procedure_Call_Statement (Loc,
2240 New_Reference_To (Deep_Fin, Loc),
2241 Parameter_Associations =>
2242 New_Copy_List_Tree (Parameter_Associations (N))));
2249 -- Ada 2005 (AI-345): We have a procedure call as a triggering
2250 -- alternative in an asynchronous select or as an entry call in
2251 -- a conditional or timed select. Check whether the procedure call
2252 -- is a renaming of an entry and rewrite it as an entry call.
2254 if Ada_Version >= Ada_2005
2255 and then Nkind (Call_Node) = N_Procedure_Call_Statement
2257 ((Nkind (Parent (Call_Node)) = N_Triggering_Alternative
2258 and then Triggering_Statement (Parent (Call_Node)) = Call_Node)
2260 (Nkind (Parent (Call_Node)) = N_Entry_Call_Alternative
2261 and then Entry_Call_Statement (Parent (Call_Node)) = Call_Node))
2265 Ren_Root : Entity_Id := Subp;
2268 -- This may be a chain of renamings, find the root
2270 if Present (Alias (Ren_Root)) then
2271 Ren_Root := Alias (Ren_Root);
2274 if Present (Original_Node (Parent (Parent (Ren_Root)))) then
2275 Ren_Decl := Original_Node (Parent (Parent (Ren_Root)));
2277 if Nkind (Ren_Decl) = N_Subprogram_Renaming_Declaration then
2279 Make_Entry_Call_Statement (Loc,
2281 New_Copy_Tree (Name (Ren_Decl)),
2282 Parameter_Associations =>
2284 (Parameter_Associations (Call_Node))));
2292 -- First step, compute extra actuals, corresponding to any Extra_Formals
2293 -- present. Note that we do not access Extra_Formals directly, instead
2294 -- we simply note the presence of the extra formals as we process the
2295 -- regular formals collecting corresponding actuals in Extra_Actuals.
2297 -- We also generate any required range checks for actuals for in formals
2298 -- as we go through the loop, since this is a convenient place to do it.
2299 -- (Though it seems that this would be better done in Expand_Actuals???)
2301 Formal := First_Formal (Subp);
2302 Actual := First_Actual (Call_Node);
2304 while Present (Formal) loop
2306 -- Generate range check if required
2308 if Do_Range_Check (Actual)
2309 and then Ekind (Formal) = E_In_Parameter
2311 Set_Do_Range_Check (Actual, False);
2312 Generate_Range_Check
2313 (Actual, Etype (Formal), CE_Range_Check_Failed);
2316 -- Prepare to examine current entry
2319 Prev_Orig := Original_Node (Prev);
2321 -- Ada 2005 (AI-251): Check if any formal is a class-wide interface
2322 -- to expand it in a further round.
2324 CW_Interface_Formals_Present :=
2325 CW_Interface_Formals_Present
2327 (Ekind (Etype (Formal)) = E_Class_Wide_Type
2328 and then Is_Interface (Etype (Etype (Formal))))
2330 (Ekind (Etype (Formal)) = E_Anonymous_Access_Type
2331 and then Is_Interface (Directly_Designated_Type
2332 (Etype (Etype (Formal)))));
2334 -- Create possible extra actual for constrained case. Usually, the
2335 -- extra actual is of the form actual'constrained, but since this
2336 -- attribute is only available for unconstrained records, TRUE is
2337 -- expanded if the type of the formal happens to be constrained (for
2338 -- instance when this procedure is inherited from an unconstrained
2339 -- record to a constrained one) or if the actual has no discriminant
2340 -- (its type is constrained). An exception to this is the case of a
2341 -- private type without discriminants. In this case we pass FALSE
2342 -- because the object has underlying discriminants with defaults.
2344 if Present (Extra_Constrained (Formal)) then
2345 if Ekind (Etype (Prev)) in Private_Kind
2346 and then not Has_Discriminants (Base_Type (Etype (Prev)))
2349 (New_Occurrence_Of (Standard_False, Loc),
2350 Extra_Constrained (Formal));
2352 elsif Is_Constrained (Etype (Formal))
2353 or else not Has_Discriminants (Etype (Prev))
2356 (New_Occurrence_Of (Standard_True, Loc),
2357 Extra_Constrained (Formal));
2359 -- Do not produce extra actuals for Unchecked_Union parameters.
2360 -- Jump directly to the end of the loop.
2362 elsif Is_Unchecked_Union (Base_Type (Etype (Actual))) then
2363 goto Skip_Extra_Actual_Generation;
2366 -- If the actual is a type conversion, then the constrained
2367 -- test applies to the actual, not the target type.
2373 -- Test for unchecked conversions as well, which can occur
2374 -- as out parameter actuals on calls to stream procedures.
2377 while Nkind_In (Act_Prev, N_Type_Conversion,
2378 N_Unchecked_Type_Conversion)
2380 Act_Prev := Expression (Act_Prev);
2383 -- If the expression is a conversion of a dereference, this
2384 -- is internally generated code that manipulates addresses,
2385 -- e.g. when building interface tables. No check should
2386 -- occur in this case, and the discriminated object is not
2389 if not Comes_From_Source (Actual)
2390 and then Nkind (Actual) = N_Unchecked_Type_Conversion
2391 and then Nkind (Act_Prev) = N_Explicit_Dereference
2394 (New_Occurrence_Of (Standard_False, Loc),
2395 Extra_Constrained (Formal));
2399 (Make_Attribute_Reference (Sloc (Prev),
2401 Duplicate_Subexpr_No_Checks
2402 (Act_Prev, Name_Req => True),
2403 Attribute_Name => Name_Constrained),
2404 Extra_Constrained (Formal));
2410 -- Create possible extra actual for accessibility level
2412 if Present (Extra_Accessibility (Formal)) then
2414 -- Ada 2005 (AI-252): If the actual was rewritten as an Access
2415 -- attribute, then the original actual may be an aliased object
2416 -- occurring as the prefix in a call using "Object.Operation"
2417 -- notation. In that case we must pass the level of the object,
2418 -- so Prev_Orig is reset to Prev and the attribute will be
2419 -- processed by the code for Access attributes further below.
2421 if Prev_Orig /= Prev
2422 and then Nkind (Prev) = N_Attribute_Reference
2424 Get_Attribute_Id (Attribute_Name (Prev)) = Attribute_Access
2425 and then Is_Aliased_View (Prev_Orig)
2430 -- Ada 2005 (AI-251): Thunks must propagate the extra actuals of
2431 -- accessibility levels.
2433 if Ekind (Current_Scope) in Subprogram_Kind
2434 and then Is_Thunk (Current_Scope)
2437 Parm_Ent : Entity_Id;
2440 if Is_Controlling_Actual (Actual) then
2442 -- Find the corresponding actual of the thunk
2444 Parm_Ent := First_Entity (Current_Scope);
2445 for J in 2 .. Param_Count loop
2446 Next_Entity (Parm_Ent);
2449 else pragma Assert (Is_Entity_Name (Actual));
2450 Parm_Ent := Entity (Actual);
2454 (New_Occurrence_Of (Extra_Accessibility (Parm_Ent), Loc),
2455 Extra_Accessibility (Formal));
2458 elsif Is_Entity_Name (Prev_Orig) then
2460 -- When passing an access parameter, or a renaming of an access
2461 -- parameter, as the actual to another access parameter we need
2462 -- to pass along the actual's own access level parameter. This
2463 -- is done if we are within the scope of the formal access
2464 -- parameter (if this is an inlined body the extra formal is
2467 if (Is_Formal (Entity (Prev_Orig))
2469 (Present (Renamed_Object (Entity (Prev_Orig)))
2471 Is_Entity_Name (Renamed_Object (Entity (Prev_Orig)))
2474 (Entity (Renamed_Object (Entity (Prev_Orig))))))
2475 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
2476 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
2479 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
2482 pragma Assert (Present (Parm_Ent));
2484 if Present (Extra_Accessibility (Parm_Ent)) then
2487 (Extra_Accessibility (Parm_Ent), Loc),
2488 Extra_Accessibility (Formal));
2490 -- If the actual access parameter does not have an
2491 -- associated extra formal providing its scope level,
2492 -- then treat the actual as having library-level
2497 (Make_Integer_Literal (Loc,
2498 Intval => Scope_Depth (Standard_Standard)),
2499 Extra_Accessibility (Formal));
2503 -- The actual is a normal access value, so just pass the level
2504 -- of the actual's access type.
2508 (Dynamic_Accessibility_Level (Prev_Orig),
2509 Extra_Accessibility (Formal));
2512 -- If the actual is an access discriminant, then pass the level
2513 -- of the enclosing object (RM05-3.10.2(12.4/2)).
2515 elsif Nkind (Prev_Orig) = N_Selected_Component
2516 and then Ekind (Entity (Selector_Name (Prev_Orig))) =
2518 and then Ekind (Etype (Entity (Selector_Name (Prev_Orig)))) =
2519 E_Anonymous_Access_Type
2522 (Make_Integer_Literal (Loc,
2523 Intval => Object_Access_Level (Prefix (Prev_Orig))),
2524 Extra_Accessibility (Formal));
2529 case Nkind (Prev_Orig) is
2531 when N_Attribute_Reference =>
2532 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
2534 -- For X'Access, pass on the level of the prefix X
2536 when Attribute_Access =>
2538 -- If this is an Access attribute applied to the
2539 -- the current instance object passed to a type
2540 -- initialization procedure, then use the level
2541 -- of the type itself. This is not really correct,
2542 -- as there should be an extra level parameter
2543 -- passed in with _init formals (only in the case
2544 -- where the type is immutably limited), but we
2545 -- don't have an easy way currently to create such
2546 -- an extra formal (init procs aren't ever frozen).
2547 -- For now we just use the level of the type,
2548 -- which may be too shallow, but that works better
2549 -- than passing Object_Access_Level of the type,
2550 -- which can be one level too deep in some cases.
2553 if Is_Entity_Name (Prefix (Prev_Orig))
2554 and then Is_Type (Entity (Prefix (Prev_Orig)))
2557 (Make_Integer_Literal (Loc,
2560 (Entity (Prefix (Prev_Orig)))),
2561 Extra_Accessibility (Formal));
2565 (Make_Integer_Literal (Loc,
2568 (Prefix (Prev_Orig))),
2569 Extra_Accessibility (Formal));
2572 -- Treat the unchecked attributes as library-level
2574 when Attribute_Unchecked_Access |
2575 Attribute_Unrestricted_Access =>
2577 (Make_Integer_Literal (Loc,
2578 Intval => Scope_Depth (Standard_Standard)),
2579 Extra_Accessibility (Formal));
2581 -- No other cases of attributes returning access
2582 -- values that can be passed to access parameters.
2585 raise Program_Error;
2589 -- For allocators we pass the level of the execution of the
2590 -- called subprogram, which is one greater than the current
2595 (Make_Integer_Literal (Loc,
2596 Intval => Scope_Depth (Current_Scope) + 1),
2597 Extra_Accessibility (Formal));
2599 -- For most other cases we simply pass the level of the
2600 -- actual's access type. The type is retrieved from
2601 -- Prev rather than Prev_Orig, because in some cases
2602 -- Prev_Orig denotes an original expression that has
2603 -- not been analyzed.
2607 (Dynamic_Accessibility_Level (Prev),
2608 Extra_Accessibility (Formal));
2613 -- Perform the check of 4.6(49) that prevents a null value from being
2614 -- passed as an actual to an access parameter. Note that the check
2615 -- is elided in the common cases of passing an access attribute or
2616 -- access parameter as an actual. Also, we currently don't enforce
2617 -- this check for expander-generated actuals and when -gnatdj is set.
2619 if Ada_Version >= Ada_2005 then
2621 -- Ada 2005 (AI-231): Check null-excluding access types. Note that
2622 -- the intent of 6.4.1(13) is that null-exclusion checks should
2623 -- not be done for 'out' parameters, even though it refers only
2624 -- to constraint checks, and a null_exclusion is not a constraint.
2625 -- Note that AI05-0196-1 corrects this mistake in the RM.
2627 if Is_Access_Type (Etype (Formal))
2628 and then Can_Never_Be_Null (Etype (Formal))
2629 and then Ekind (Formal) /= E_Out_Parameter
2630 and then Nkind (Prev) /= N_Raise_Constraint_Error
2631 and then (Known_Null (Prev)
2632 or else not Can_Never_Be_Null (Etype (Prev)))
2634 Install_Null_Excluding_Check (Prev);
2637 -- Ada_Version < Ada_2005
2640 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
2641 or else Access_Checks_Suppressed (Subp)
2645 elsif Debug_Flag_J then
2648 elsif not Comes_From_Source (Prev) then
2651 elsif Is_Entity_Name (Prev)
2652 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
2656 elsif Nkind_In (Prev, N_Allocator, N_Attribute_Reference) then
2659 -- Suppress null checks when passing to access parameters of Java
2660 -- and CIL subprograms. (Should this be done for other foreign
2661 -- conventions as well ???)
2663 elsif Convention (Subp) = Convention_Java
2664 or else Convention (Subp) = Convention_CIL
2669 Install_Null_Excluding_Check (Prev);
2673 -- Perform appropriate validity checks on parameters that
2676 if Validity_Checks_On then
2677 if (Ekind (Formal) = E_In_Parameter
2678 and then Validity_Check_In_Params)
2680 (Ekind (Formal) = E_In_Out_Parameter
2681 and then Validity_Check_In_Out_Params)
2683 -- If the actual is an indexed component of a packed type (or
2684 -- is an indexed or selected component whose prefix recursively
2685 -- meets this condition), it has not been expanded yet. It will
2686 -- be copied in the validity code that follows, and has to be
2687 -- expanded appropriately, so reanalyze it.
2689 -- What we do is just to unset analyzed bits on prefixes till
2690 -- we reach something that does not have a prefix.
2697 while Nkind_In (Nod, N_Indexed_Component,
2698 N_Selected_Component)
2700 Set_Analyzed (Nod, False);
2701 Nod := Prefix (Nod);
2705 Ensure_Valid (Actual);
2709 -- For Ada 2012, if a parameter is aliased, the actual must be a
2710 -- tagged type or an aliased view of an object.
2712 if Is_Aliased (Formal)
2713 and then not Is_Aliased_View (Actual)
2714 and then not Is_Tagged_Type (Etype (Formal))
2717 ("actual for aliased formal& must be aliased object",
2721 -- For IN OUT and OUT parameters, ensure that subscripts are valid
2722 -- since this is a left side reference. We only do this for calls
2723 -- from the source program since we assume that compiler generated
2724 -- calls explicitly generate any required checks. We also need it
2725 -- only if we are doing standard validity checks, since clearly it is
2726 -- not needed if validity checks are off, and in subscript validity
2727 -- checking mode, all indexed components are checked with a call
2728 -- directly from Expand_N_Indexed_Component.
2730 if Comes_From_Source (Call_Node)
2731 and then Ekind (Formal) /= E_In_Parameter
2732 and then Validity_Checks_On
2733 and then Validity_Check_Default
2734 and then not Validity_Check_Subscripts
2736 Check_Valid_Lvalue_Subscripts (Actual);
2739 -- Mark any scalar OUT parameter that is a simple variable as no
2740 -- longer known to be valid (unless the type is always valid). This
2741 -- reflects the fact that if an OUT parameter is never set in a
2742 -- procedure, then it can become invalid on the procedure return.
2744 if Ekind (Formal) = E_Out_Parameter
2745 and then Is_Entity_Name (Actual)
2746 and then Ekind (Entity (Actual)) = E_Variable
2747 and then not Is_Known_Valid (Etype (Actual))
2749 Set_Is_Known_Valid (Entity (Actual), False);
2752 -- For an OUT or IN OUT parameter, if the actual is an entity, then
2753 -- clear current values, since they can be clobbered. We are probably
2754 -- doing this in more places than we need to, but better safe than
2755 -- sorry when it comes to retaining bad current values!
2757 if Ekind (Formal) /= E_In_Parameter
2758 and then Is_Entity_Name (Actual)
2759 and then Present (Entity (Actual))
2762 Ent : constant Entity_Id := Entity (Actual);
2766 -- For an OUT or IN OUT parameter that is an assignable entity,
2767 -- we do not want to clobber the Last_Assignment field, since
2768 -- if it is set, it was precisely because it is indeed an OUT
2769 -- or IN OUT parameter! We do reset the Is_Known_Valid flag
2770 -- since the subprogram could have returned in invalid value.
2772 if Ekind_In (Formal, E_Out_Parameter, E_In_Out_Parameter)
2773 and then Is_Assignable (Ent)
2775 Sav := Last_Assignment (Ent);
2776 Kill_Current_Values (Ent);
2777 Set_Last_Assignment (Ent, Sav);
2778 Set_Is_Known_Valid (Ent, False);
2780 -- For all other cases, just kill the current values
2783 Kill_Current_Values (Ent);
2788 -- If the formal is class wide and the actual is an aggregate, force
2789 -- evaluation so that the back end who does not know about class-wide
2790 -- type, does not generate a temporary of the wrong size.
2792 if not Is_Class_Wide_Type (Etype (Formal)) then
2795 elsif Nkind (Actual) = N_Aggregate
2796 or else (Nkind (Actual) = N_Qualified_Expression
2797 and then Nkind (Expression (Actual)) = N_Aggregate)
2799 Force_Evaluation (Actual);
2802 -- In a remote call, if the formal is of a class-wide type, check
2803 -- that the actual meets the requirements described in E.4(18).
2805 if Remote and then Is_Class_Wide_Type (Etype (Formal)) then
2806 Insert_Action (Actual,
2807 Make_Transportable_Check (Loc,
2808 Duplicate_Subexpr_Move_Checks (Actual)));
2811 -- This label is required when skipping extra actual generation for
2812 -- Unchecked_Union parameters.
2814 <<Skip_Extra_Actual_Generation>>
2816 Param_Count := Param_Count + 1;
2817 Next_Actual (Actual);
2818 Next_Formal (Formal);
2821 -- If we are calling an Ada 2012 function which needs to have the
2822 -- "accessibility level determined by the point of call" (AI05-0234)
2823 -- passed in to it, then pass it in.
2825 if Ekind_In (Subp, E_Function, E_Operator, E_Subprogram_Type)
2827 Present (Extra_Accessibility_Of_Result (Ultimate_Alias (Subp)))
2830 Ancestor : Node_Id := Parent (Call_Node);
2831 Level : Node_Id := Empty;
2832 Defer : Boolean := False;
2835 -- Unimplemented: if Subp returns an anonymous access type, then
2837 -- a) if the call is the operand of an explict conversion, then
2838 -- the target type of the conversion (a named access type)
2839 -- determines the accessibility level pass in;
2841 -- b) if the call defines an access discriminant of an object
2842 -- (e.g., the discriminant of an object being created by an
2843 -- allocator, or the discriminant of a function result),
2844 -- then the accessibility level to pass in is that of the
2845 -- discriminated object being initialized).
2849 while Nkind (Ancestor) = N_Qualified_Expression
2851 Ancestor := Parent (Ancestor);
2854 case Nkind (Ancestor) is
2857 -- At this point, we'd like to assign
2859 -- Level := Dynamic_Accessibility_Level (Ancestor);
2861 -- but Etype of Ancestor may not have been set yet,
2862 -- so that doesn't work.
2864 -- Handle this later in Expand_Allocator_Expression.
2868 when N_Object_Declaration | N_Object_Renaming_Declaration =>
2870 Def_Id : constant Entity_Id :=
2871 Defining_Identifier (Ancestor);
2874 if Is_Return_Object (Def_Id) then
2875 if Present (Extra_Accessibility_Of_Result
2876 (Return_Applies_To (Scope (Def_Id))))
2878 -- Pass along value that was passed in if the
2879 -- routine we are returning from also has an
2880 -- Accessibility_Of_Result formal.
2884 (Extra_Accessibility_Of_Result
2885 (Return_Applies_To (Scope (Def_Id))), Loc);
2889 Make_Integer_Literal (Loc,
2890 Intval => Object_Access_Level (Def_Id));
2894 when N_Simple_Return_Statement =>
2895 if Present (Extra_Accessibility_Of_Result
2897 (Return_Statement_Entity (Ancestor))))
2899 -- Pass along value that was passed in if the routine
2900 -- we are returning from also has an
2901 -- Accessibility_Of_Result formal.
2905 (Extra_Accessibility_Of_Result
2907 (Return_Statement_Entity (Ancestor))), Loc);
2915 if not Present (Level) then
2917 -- The "innermost master that evaluates the function call".
2919 -- ??? - Should we use Integer'Last here instead in order
2920 -- to deal with (some of) the problems associated with
2921 -- calls to subps whose enclosing scope is unknown (e.g.,
2922 -- Anon_Access_To_Subp_Param.all)?
2924 Level := Make_Integer_Literal (Loc,
2925 Scope_Depth (Current_Scope) + 1);
2930 Extra_Accessibility_Of_Result (Ultimate_Alias (Subp)));
2935 -- If we are expanding a rhs of an assignment we need to check if tag
2936 -- propagation is needed. You might expect this processing to be in
2937 -- Analyze_Assignment but has to be done earlier (bottom-up) because the
2938 -- assignment might be transformed to a declaration for an unconstrained
2939 -- value if the expression is classwide.
2941 if Nkind (Call_Node) = N_Function_Call
2942 and then Is_Tag_Indeterminate (Call_Node)
2943 and then Is_Entity_Name (Name (Call_Node))
2946 Ass : Node_Id := Empty;
2949 if Nkind (Parent (Call_Node)) = N_Assignment_Statement then
2950 Ass := Parent (Call_Node);
2952 elsif Nkind (Parent (Call_Node)) = N_Qualified_Expression
2953 and then Nkind (Parent (Parent (Call_Node))) =
2954 N_Assignment_Statement
2956 Ass := Parent (Parent (Call_Node));
2958 elsif Nkind (Parent (Call_Node)) = N_Explicit_Dereference
2959 and then Nkind (Parent (Parent (Call_Node))) =
2960 N_Assignment_Statement
2962 Ass := Parent (Parent (Call_Node));
2966 and then Is_Class_Wide_Type (Etype (Name (Ass)))
2968 if Is_Access_Type (Etype (Call_Node)) then
2969 if Designated_Type (Etype (Call_Node)) /=
2970 Root_Type (Etype (Name (Ass)))
2973 ("tag-indeterminate expression "
2974 & " must have designated type& (RM 5.2 (6))",
2975 Call_Node, Root_Type (Etype (Name (Ass))));
2977 Propagate_Tag (Name (Ass), Call_Node);
2980 elsif Etype (Call_Node) /= Root_Type (Etype (Name (Ass))) then
2982 ("tag-indeterminate expression must have type&"
2984 Call_Node, Root_Type (Etype (Name (Ass))));
2987 Propagate_Tag (Name (Ass), Call_Node);
2990 -- The call will be rewritten as a dispatching call, and
2991 -- expanded as such.
2998 -- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
2999 -- it to point to the correct secondary virtual table
3001 if Nkind_In (Call_Node, N_Function_Call, N_Procedure_Call_Statement)
3002 and then CW_Interface_Formals_Present
3004 Expand_Interface_Actuals (Call_Node);
3007 -- Deals with Dispatch_Call if we still have a call, before expanding
3008 -- extra actuals since this will be done on the re-analysis of the
3009 -- dispatching call. Note that we do not try to shorten the actual list
3010 -- for a dispatching call, it would not make sense to do so. Expansion
3011 -- of dispatching calls is suppressed when VM_Target, because the VM
3012 -- back-ends directly handle the generation of dispatching calls and
3013 -- would have to undo any expansion to an indirect call.
3015 if Nkind_In (Call_Node, N_Function_Call, N_Procedure_Call_Statement)
3016 and then Present (Controlling_Argument (Call_Node))
3019 Call_Typ : constant Entity_Id := Etype (Call_Node);
3020 Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
3021 Eq_Prim_Op : Entity_Id := Empty;
3024 Prev_Call : Node_Id;
3027 if not Is_Limited_Type (Typ) then
3028 Eq_Prim_Op := Find_Prim_Op (Typ, Name_Op_Eq);
3031 if Tagged_Type_Expansion then
3032 Expand_Dispatching_Call (Call_Node);
3034 -- The following return is worrisome. Is it really OK to skip
3035 -- all remaining processing in this procedure ???
3042 Apply_Tag_Checks (Call_Node);
3044 -- If this is a dispatching "=", we must first compare the
3045 -- tags so we generate: x.tag = y.tag and then x = y
3047 if Subp = Eq_Prim_Op then
3049 -- Mark the node as analyzed to avoid reanalizing this
3050 -- dispatching call (which would cause a never-ending loop)
3052 Prev_Call := Relocate_Node (Call_Node);
3053 Set_Analyzed (Prev_Call);
3055 Param := First_Actual (Call_Node);
3061 Make_Selected_Component (Loc,
3062 Prefix => New_Value (Param),
3064 New_Reference_To (First_Tag_Component (Typ),
3068 Make_Selected_Component (Loc,
3070 Unchecked_Convert_To (Typ,
3071 New_Value (Next_Actual (Param))),
3074 (First_Tag_Component (Typ), Loc))),
3075 Right_Opnd => Prev_Call);
3077 Rewrite (Call_Node, New_Call);
3080 (Call_Node, Call_Typ, Suppress => All_Checks);
3083 -- Expansion of a dispatching call results in an indirect call,
3084 -- which in turn causes current values to be killed (see
3085 -- Resolve_Call), so on VM targets we do the call here to
3086 -- ensure consistent warnings between VM and non-VM targets.
3088 Kill_Current_Values;
3091 -- If this is a dispatching "=" then we must update the reference
3092 -- to the call node because we generated:
3093 -- x.tag = y.tag and then x = y
3095 if Subp = Eq_Prim_Op then
3096 Call_Node := Right_Opnd (Call_Node);
3101 -- Similarly, expand calls to RCI subprograms on which pragma
3102 -- All_Calls_Remote applies. The rewriting will be reanalyzed
3103 -- later. Do this only when the call comes from source since we
3104 -- do not want such a rewriting to occur in expanded code.
3106 if Is_All_Remote_Call (Call_Node) then
3107 Expand_All_Calls_Remote_Subprogram_Call (Call_Node);
3109 -- Similarly, do not add extra actuals for an entry call whose entity
3110 -- is a protected procedure, or for an internal protected subprogram
3111 -- call, because it will be rewritten as a protected subprogram call
3112 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
3114 elsif Is_Protected_Type (Scope (Subp))
3115 and then (Ekind (Subp) = E_Procedure
3116 or else Ekind (Subp) = E_Function)
3120 -- During that loop we gathered the extra actuals (the ones that
3121 -- correspond to Extra_Formals), so now they can be appended.
3124 while Is_Non_Empty_List (Extra_Actuals) loop
3125 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
3129 -- At this point we have all the actuals, so this is the point at which
3130 -- the various expansion activities for actuals is carried out.
3132 Expand_Actuals (Call_Node, Subp);
3134 -- If the subprogram is a renaming, or if it is inherited, replace it in
3135 -- the call with the name of the actual subprogram being called. If this
3136 -- is a dispatching call, the run-time decides what to call. The Alias
3137 -- attribute does not apply to entries.
3139 if Nkind (Call_Node) /= N_Entry_Call_Statement
3140 and then No (Controlling_Argument (Call_Node))
3141 and then Present (Parent_Subp)
3142 and then not Is_Direct_Deep_Call (Subp)
3144 if Present (Inherited_From_Formal (Subp)) then
3145 Parent_Subp := Inherited_From_Formal (Subp);
3147 Parent_Subp := Ultimate_Alias (Parent_Subp);
3150 -- The below setting of Entity is suspect, see F109-018 discussion???
3152 Set_Entity (Name (Call_Node), Parent_Subp);
3154 if Is_Abstract_Subprogram (Parent_Subp)
3155 and then not In_Instance
3158 ("cannot call abstract subprogram &!",
3159 Name (Call_Node), Parent_Subp);
3162 -- Inspect all formals of derived subprogram Subp. Compare parameter
3163 -- types with the parent subprogram and check whether an actual may
3164 -- need a type conversion to the corresponding formal of the parent
3167 -- Not clear whether intrinsic subprograms need such conversions. ???
3169 if not Is_Intrinsic_Subprogram (Parent_Subp)
3170 or else Is_Generic_Instance (Parent_Subp)
3173 procedure Convert (Act : Node_Id; Typ : Entity_Id);
3174 -- Rewrite node Act as a type conversion of Act to Typ. Analyze
3175 -- and resolve the newly generated construct.
3181 procedure Convert (Act : Node_Id; Typ : Entity_Id) is
3183 Rewrite (Act, OK_Convert_To (Typ, Relocate_Node (Act)));
3190 Actual_Typ : Entity_Id;
3191 Formal_Typ : Entity_Id;
3192 Parent_Typ : Entity_Id;
3195 Actual := First_Actual (Call_Node);
3196 Formal := First_Formal (Subp);
3197 Parent_Formal := First_Formal (Parent_Subp);
3198 while Present (Formal) loop
3199 Actual_Typ := Etype (Actual);
3200 Formal_Typ := Etype (Formal);
3201 Parent_Typ := Etype (Parent_Formal);
3203 -- For an IN parameter of a scalar type, the parent formal
3204 -- type and derived formal type differ or the parent formal
3205 -- type and actual type do not match statically.
3207 if Is_Scalar_Type (Formal_Typ)
3208 and then Ekind (Formal) = E_In_Parameter
3209 and then Formal_Typ /= Parent_Typ
3211 not Subtypes_Statically_Match (Parent_Typ, Actual_Typ)
3212 and then not Raises_Constraint_Error (Actual)
3214 Convert (Actual, Parent_Typ);
3215 Enable_Range_Check (Actual);
3217 -- If the actual has been marked as requiring a range
3218 -- check, then generate it here.
3220 if Do_Range_Check (Actual) then
3221 Set_Do_Range_Check (Actual, False);
3222 Generate_Range_Check
3223 (Actual, Etype (Formal), CE_Range_Check_Failed);
3226 -- For access types, the parent formal type and actual type
3229 elsif Is_Access_Type (Formal_Typ)
3230 and then Base_Type (Parent_Typ) /= Base_Type (Actual_Typ)
3232 if Ekind (Formal) /= E_In_Parameter then
3233 Convert (Actual, Parent_Typ);
3235 elsif Ekind (Parent_Typ) = E_Anonymous_Access_Type
3236 and then Designated_Type (Parent_Typ) /=
3237 Designated_Type (Actual_Typ)
3238 and then not Is_Controlling_Formal (Formal)
3240 -- This unchecked conversion is not necessary unless
3241 -- inlining is enabled, because in that case the type
3242 -- mismatch may become visible in the body about to be
3246 Unchecked_Convert_To (Parent_Typ,
3247 Relocate_Node (Actual)));
3249 Resolve (Actual, Parent_Typ);
3252 -- For array and record types, the parent formal type and
3253 -- derived formal type have different sizes or pragma Pack
3256 elsif ((Is_Array_Type (Formal_Typ)
3257 and then Is_Array_Type (Parent_Typ))
3259 (Is_Record_Type (Formal_Typ)
3260 and then Is_Record_Type (Parent_Typ)))
3262 (Esize (Formal_Typ) /= Esize (Parent_Typ)
3263 or else Has_Pragma_Pack (Formal_Typ) /=
3264 Has_Pragma_Pack (Parent_Typ))
3266 Convert (Actual, Parent_Typ);
3269 Next_Actual (Actual);
3270 Next_Formal (Formal);
3271 Next_Formal (Parent_Formal);
3277 Subp := Parent_Subp;
3280 -- Check for violation of No_Abort_Statements
3282 if Restriction_Check_Required (No_Abort_Statements)
3283 and then Is_RTE (Subp, RE_Abort_Task)
3285 Check_Restriction (No_Abort_Statements, Call_Node);
3287 -- Check for violation of No_Dynamic_Attachment
3289 elsif Restriction_Check_Required (No_Dynamic_Attachment)
3290 and then RTU_Loaded (Ada_Interrupts)
3291 and then (Is_RTE (Subp, RE_Is_Reserved) or else
3292 Is_RTE (Subp, RE_Is_Attached) or else
3293 Is_RTE (Subp, RE_Current_Handler) or else
3294 Is_RTE (Subp, RE_Attach_Handler) or else
3295 Is_RTE (Subp, RE_Exchange_Handler) or else
3296 Is_RTE (Subp, RE_Detach_Handler) or else
3297 Is_RTE (Subp, RE_Reference))
3299 Check_Restriction (No_Dynamic_Attachment, Call_Node);
3302 -- Deal with case where call is an explicit dereference
3304 if Nkind (Name (Call_Node)) = N_Explicit_Dereference then
3306 -- Handle case of access to protected subprogram type
3308 if Is_Access_Protected_Subprogram_Type
3309 (Base_Type (Etype (Prefix (Name (Call_Node)))))
3311 -- If this is a call through an access to protected operation, the
3312 -- prefix has the form (object'address, operation'access). Rewrite
3313 -- as a for other protected calls: the object is the 1st parameter
3314 -- of the list of actuals.
3321 Ptr : constant Node_Id := Prefix (Name (Call_Node));
3323 T : constant Entity_Id :=
3324 Equivalent_Type (Base_Type (Etype (Ptr)));
3326 D_T : constant Entity_Id :=
3327 Designated_Type (Base_Type (Etype (Ptr)));
3331 Make_Selected_Component (Loc,
3332 Prefix => Unchecked_Convert_To (T, Ptr),
3334 New_Occurrence_Of (First_Entity (T), Loc));
3337 Make_Selected_Component (Loc,
3338 Prefix => Unchecked_Convert_To (T, Ptr),
3340 New_Occurrence_Of (Next_Entity (First_Entity (T)), Loc));
3343 Make_Explicit_Dereference (Loc,
3346 if Present (Parameter_Associations (Call_Node)) then
3347 Parm := Parameter_Associations (Call_Node);
3352 Prepend (Obj, Parm);
3354 if Etype (D_T) = Standard_Void_Type then
3356 Make_Procedure_Call_Statement (Loc,
3358 Parameter_Associations => Parm);
3361 Make_Function_Call (Loc,
3363 Parameter_Associations => Parm);
3366 Set_First_Named_Actual (Call, First_Named_Actual (Call_Node));
3367 Set_Etype (Call, Etype (D_T));
3369 -- We do not re-analyze the call to avoid infinite recursion.
3370 -- We analyze separately the prefix and the object, and set
3371 -- the checks on the prefix that would otherwise be emitted
3372 -- when resolving a call.
3374 Rewrite (Call_Node, Call);
3376 Apply_Access_Check (Nam);
3383 -- If this is a call to an intrinsic subprogram, then perform the
3384 -- appropriate expansion to the corresponding tree node and we
3385 -- are all done (since after that the call is gone!)
3387 -- In the case where the intrinsic is to be processed by the back end,
3388 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
3389 -- since the idea in this case is to pass the call unchanged. If the
3390 -- intrinsic is an inherited unchecked conversion, and the derived type
3391 -- is the target type of the conversion, we must retain it as the return
3392 -- type of the expression. Otherwise the expansion below, which uses the
3393 -- parent operation, will yield the wrong type.
3395 if Is_Intrinsic_Subprogram (Subp) then
3396 Expand_Intrinsic_Call (Call_Node, Subp);
3398 if Nkind (Call_Node) = N_Unchecked_Type_Conversion
3399 and then Parent_Subp /= Orig_Subp
3400 and then Etype (Parent_Subp) /= Etype (Orig_Subp)
3402 Set_Etype (Call_Node, Etype (Orig_Subp));
3408 if Ekind_In (Subp, E_Function, E_Procedure) then
3410 -- We perform two simple optimization on calls:
3412 -- a) replace calls to null procedures unconditionally;
3414 -- b) for To_Address, just do an unchecked conversion. Not only is
3415 -- this efficient, but it also avoids order of elaboration problems
3416 -- when address clauses are inlined (address expression elaborated
3417 -- at the wrong point).
3419 -- We perform these optimization regardless of whether we are in the
3420 -- main unit or in a unit in the context of the main unit, to ensure
3421 -- that tree generated is the same in both cases, for Inspector use.
3423 if Is_RTE (Subp, RE_To_Address) then
3425 Unchecked_Convert_To
3426 (RTE (RE_Address), Relocate_Node (First_Actual (Call_Node))));
3429 elsif Is_Null_Procedure (Subp) then
3430 Rewrite (Call_Node, Make_Null_Statement (Loc));
3434 if Is_Inlined (Subp) then
3436 Inlined_Subprogram : declare
3438 Must_Inline : Boolean := False;
3439 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
3440 Scop : constant Entity_Id := Scope (Subp);
3442 function In_Unfrozen_Instance return Boolean;
3443 -- If the subprogram comes from an instance in the same unit,
3444 -- and the instance is not yet frozen, inlining might trigger
3445 -- order-of-elaboration problems in gigi.
3447 --------------------------
3448 -- In_Unfrozen_Instance --
3449 --------------------------
3451 function In_Unfrozen_Instance return Boolean is
3457 and then S /= Standard_Standard
3459 if Is_Generic_Instance (S)
3460 and then Present (Freeze_Node (S))
3461 and then not Analyzed (Freeze_Node (S))
3470 end In_Unfrozen_Instance;
3472 -- Start of processing for Inlined_Subprogram
3475 -- Verify that the body to inline has already been seen, and
3476 -- that if the body is in the current unit the inlining does
3477 -- not occur earlier. This avoids order-of-elaboration problems
3480 -- This should be documented in sinfo/einfo ???
3483 or else Nkind (Spec) /= N_Subprogram_Declaration
3484 or else No (Body_To_Inline (Spec))
3486 Must_Inline := False;
3488 -- If this an inherited function that returns a private type,
3489 -- do not inline if the full view is an unconstrained array,
3490 -- because such calls cannot be inlined.
3492 elsif Present (Orig_Subp)
3493 and then Is_Array_Type (Etype (Orig_Subp))
3494 and then not Is_Constrained (Etype (Orig_Subp))
3496 Must_Inline := False;
3498 elsif In_Unfrozen_Instance then
3499 Must_Inline := False;
3502 Bod := Body_To_Inline (Spec);
3504 if (In_Extended_Main_Code_Unit (Call_Node)
3505 or else In_Extended_Main_Code_Unit (Parent (Call_Node))
3506 or else Has_Pragma_Inline_Always (Subp))
3507 and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
3509 Earlier_In_Extended_Unit (Sloc (Bod), Loc))
3511 Must_Inline := True;
3513 -- If we are compiling a package body that is not the main
3514 -- unit, it must be for inlining/instantiation purposes,
3515 -- in which case we inline the call to insure that the same
3516 -- temporaries are generated when compiling the body by
3517 -- itself. Otherwise link errors can occur.
3519 -- If the function being called is itself in the main unit,
3520 -- we cannot inline, because there is a risk of double
3521 -- elaboration and/or circularity: the inlining can make
3522 -- visible a private entity in the body of the main unit,
3523 -- that gigi will see before its sees its proper definition.
3525 elsif not (In_Extended_Main_Code_Unit (Call_Node))
3526 and then In_Package_Body
3528 Must_Inline := not In_Extended_Main_Source_Unit (Subp);
3533 Expand_Inlined_Call (Call_Node, Subp, Orig_Subp);
3536 -- Let the back end handle it
3538 Add_Inlined_Body (Subp);
3540 if Front_End_Inlining
3541 and then Nkind (Spec) = N_Subprogram_Declaration
3542 and then (In_Extended_Main_Code_Unit (Call_Node))
3543 and then No (Body_To_Inline (Spec))
3544 and then not Has_Completion (Subp)
3545 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
3548 ("cannot inline& (body not seen yet)?", Call_Node, Subp);
3551 end Inlined_Subprogram;
3555 -- Check for protected subprogram. This is either an intra-object call,
3556 -- or a protected function call. Protected procedure calls are rewritten
3557 -- as entry calls and handled accordingly.
3559 -- In Ada 2005, this may be an indirect call to an access parameter that
3560 -- is an access_to_subprogram. In that case the anonymous type has a
3561 -- scope that is a protected operation, but the call is a regular one.
3562 -- In either case do not expand call if subprogram is eliminated.
3564 Scop := Scope (Subp);
3566 if Nkind (Call_Node) /= N_Entry_Call_Statement
3567 and then Is_Protected_Type (Scop)
3568 and then Ekind (Subp) /= E_Subprogram_Type
3569 and then not Is_Eliminated (Subp)
3571 -- If the call is an internal one, it is rewritten as a call to the
3572 -- corresponding unprotected subprogram.
3574 Expand_Protected_Subprogram_Call (Call_Node, Subp, Scop);
3577 -- Functions returning controlled objects need special attention. If
3578 -- the return type is limited, then the context is initialization and
3579 -- different processing applies. If the call is to a protected function,
3580 -- the expansion above will call Expand_Call recursively. Otherwise the
3581 -- function call is transformed into a temporary which obtains the
3582 -- result from the secondary stack.
3584 if Needs_Finalization (Etype (Subp)) then
3585 if not Is_Immutably_Limited_Type (Etype (Subp))
3587 (No (First_Formal (Subp))
3589 not Is_Concurrent_Record_Type (Etype (First_Formal (Subp))))
3591 Expand_Ctrl_Function_Call (Call_Node);
3593 -- Build-in-place function calls which appear in anonymous contexts
3594 -- need a transient scope to ensure the proper finalization of the
3595 -- intermediate result after its use.
3597 elsif Is_Build_In_Place_Function_Call (Call_Node)
3598 and then Nkind_In (Parent (Call_Node), N_Attribute_Reference,
3600 N_Indexed_Component,
3601 N_Object_Renaming_Declaration,
3602 N_Procedure_Call_Statement,
3603 N_Selected_Component,
3606 Establish_Transient_Scope (Call_Node, Sec_Stack => True);
3610 -- Test for First_Optional_Parameter, and if so, truncate parameter list
3611 -- if there are optional parameters at the trailing end.
3612 -- Note: we never delete procedures for call via a pointer.
3614 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
3615 and then Present (First_Optional_Parameter (Subp))
3618 Last_Keep_Arg : Node_Id;
3621 -- Last_Keep_Arg will hold the last actual that should be kept.
3622 -- If it remains empty at the end, it means that all parameters
3625 Last_Keep_Arg := Empty;
3627 -- Find first optional parameter, must be present since we checked
3628 -- the validity of the parameter before setting it.
3630 Formal := First_Formal (Subp);
3631 Actual := First_Actual (Call_Node);
3632 while Formal /= First_Optional_Parameter (Subp) loop
3633 Last_Keep_Arg := Actual;
3634 Next_Formal (Formal);
3635 Next_Actual (Actual);
3638 -- We have Formal and Actual pointing to the first potentially
3639 -- droppable argument. We can drop all the trailing arguments
3640 -- whose actual matches the default. Note that we know that all
3641 -- remaining formals have defaults, because we checked that this
3642 -- requirement was met before setting First_Optional_Parameter.
3644 -- We use Fully_Conformant_Expressions to check for identity
3645 -- between formals and actuals, which may miss some cases, but
3646 -- on the other hand, this is only an optimization (if we fail
3647 -- to truncate a parameter it does not affect functionality).
3648 -- So if the default is 3 and the actual is 1+2, we consider
3649 -- them unequal, which hardly seems worrisome.
3651 while Present (Formal) loop
3652 if not Fully_Conformant_Expressions
3653 (Actual, Default_Value (Formal))
3655 Last_Keep_Arg := Actual;
3658 Next_Formal (Formal);
3659 Next_Actual (Actual);
3662 -- If no arguments, delete entire list, this is the easy case
3664 if No (Last_Keep_Arg) then
3665 Set_Parameter_Associations (Call_Node, No_List);
3666 Set_First_Named_Actual (Call_Node, Empty);
3668 -- Case where at the last retained argument is positional. This
3669 -- is also an easy case, since the retained arguments are already
3670 -- in the right form, and we don't need to worry about the order
3671 -- of arguments that get eliminated.
3673 elsif Is_List_Member (Last_Keep_Arg) then
3674 while Present (Next (Last_Keep_Arg)) loop
3675 Discard_Node (Remove_Next (Last_Keep_Arg));
3678 Set_First_Named_Actual (Call_Node, Empty);
3680 -- This is the annoying case where the last retained argument
3681 -- is a named parameter. Since the original arguments are not
3682 -- in declaration order, we may have to delete some fairly
3683 -- random collection of arguments.
3691 -- First step, remove all the named parameters from the
3692 -- list (they are still chained using First_Named_Actual
3693 -- and Next_Named_Actual, so we have not lost them!)
3695 Temp := First (Parameter_Associations (Call_Node));
3697 -- Case of all parameters named, remove them all
3699 if Nkind (Temp) = N_Parameter_Association then
3700 -- Suppress warnings to avoid warning on possible
3701 -- infinite loop (because Call_Node is not modified).
3703 pragma Warnings (Off);
3704 while Is_Non_Empty_List
3705 (Parameter_Associations (Call_Node))
3708 Remove_Head (Parameter_Associations (Call_Node));
3710 pragma Warnings (On);
3712 -- Case of mixed positional/named, remove named parameters
3715 while Nkind (Next (Temp)) /= N_Parameter_Association loop
3719 while Present (Next (Temp)) loop
3720 Remove (Next (Temp));
3724 -- Now we loop through the named parameters, till we get
3725 -- to the last one to be retained, adding them to the list.
3726 -- Note that the Next_Named_Actual list does not need to be
3727 -- touched since we are only reordering them on the actual
3728 -- parameter association list.
3730 Passoc := Parent (First_Named_Actual (Call_Node));
3732 Temp := Relocate_Node (Passoc);
3734 (Parameter_Associations (Call_Node), Temp);
3736 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
3737 Passoc := Parent (Next_Named_Actual (Passoc));
3740 Set_Next_Named_Actual (Temp, Empty);
3743 Temp := Next_Named_Actual (Passoc);
3744 exit when No (Temp);
3745 Set_Next_Named_Actual
3746 (Passoc, Next_Named_Actual (Parent (Temp)));
3755 -------------------------------
3756 -- Expand_Ctrl_Function_Call --
3757 -------------------------------
3759 procedure Expand_Ctrl_Function_Call (N : Node_Id) is
3761 -- Optimization, if the returned value (which is on the sec-stack) is
3762 -- returned again, no need to copy/readjust/finalize, we can just pass
3763 -- the value thru (see Expand_N_Simple_Return_Statement), and thus no
3764 -- attachment is needed
3766 if Nkind (Parent (N)) = N_Simple_Return_Statement then
3770 -- Resolution is now finished, make sure we don't start analysis again
3771 -- because of the duplication.
3775 -- A function which returns a controlled object uses the secondary
3776 -- stack. Rewrite the call into a temporary which obtains the result of
3777 -- the function using 'reference.
3779 Remove_Side_Effects (N);
3780 end Expand_Ctrl_Function_Call;
3782 --------------------------
3783 -- Expand_Inlined_Call --
3784 --------------------------
3786 procedure Expand_Inlined_Call
3789 Orig_Subp : Entity_Id)
3791 Loc : constant Source_Ptr := Sloc (N);
3792 Is_Predef : constant Boolean :=
3793 Is_Predefined_File_Name
3794 (Unit_File_Name (Get_Source_Unit (Subp)));
3795 Orig_Bod : constant Node_Id :=
3796 Body_To_Inline (Unit_Declaration_Node (Subp));
3801 Decls : constant List_Id := New_List;
3802 Exit_Lab : Entity_Id := Empty;
3809 Ret_Type : Entity_Id;
3812 -- The target of the call. If context is an assignment statement then
3813 -- this is the left-hand side of the assignment. else it is a temporary
3814 -- to which the return value is assigned prior to rewriting the call.
3817 -- A separate target used when the return type is unconstrained
3820 Temp_Typ : Entity_Id;
3822 Return_Object : Entity_Id := Empty;
3823 -- Entity in declaration in an extended_return_statement
3825 Is_Unc : constant Boolean :=
3826 Is_Array_Type (Etype (Subp))
3827 and then not Is_Constrained (Etype (Subp));
3828 -- If the type returned by the function is unconstrained and the call
3829 -- can be inlined, special processing is required.
3831 procedure Make_Exit_Label;
3832 -- Build declaration for exit label to be used in Return statements,
3833 -- sets Exit_Lab (the label node) and Lab_Decl (corresponding implicit
3834 -- declaration). Does nothing if Exit_Lab already set.
3836 function Process_Formals (N : Node_Id) return Traverse_Result;
3837 -- Replace occurrence of a formal with the corresponding actual, or the
3838 -- thunk generated for it.
3840 function Process_Sloc (Nod : Node_Id) return Traverse_Result;
3841 -- If the call being expanded is that of an internal subprogram, set the
3842 -- sloc of the generated block to that of the call itself, so that the
3843 -- expansion is skipped by the "next" command in gdb.
3844 -- Same processing for a subprogram in a predefined file, e.g.
3845 -- Ada.Tags. If Debug_Generated_Code is true, suppress this change to
3846 -- simplify our own development.
3848 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
3849 -- If the function body is a single expression, replace call with
3850 -- expression, else insert block appropriately.
3852 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
3853 -- If procedure body has no local variables, inline body without
3854 -- creating block, otherwise rewrite call with block.
3856 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean;
3857 -- Determine whether a formal parameter is used only once in Orig_Bod
3859 ---------------------
3860 -- Make_Exit_Label --
3861 ---------------------
3863 procedure Make_Exit_Label is
3864 Lab_Ent : Entity_Id;
3866 if No (Exit_Lab) then
3867 Lab_Ent := Make_Temporary (Loc, 'L');
3868 Lab_Id := New_Reference_To (Lab_Ent, Loc);
3869 Exit_Lab := Make_Label (Loc, Lab_Id);
3871 Make_Implicit_Label_Declaration (Loc,
3872 Defining_Identifier => Lab_Ent,
3873 Label_Construct => Exit_Lab);
3875 end Make_Exit_Label;
3877 ---------------------
3878 -- Process_Formals --
3879 ---------------------
3881 function Process_Formals (N : Node_Id) return Traverse_Result is
3887 if Is_Entity_Name (N)
3888 and then Present (Entity (N))
3893 and then Scope (E) = Subp
3895 A := Renamed_Object (E);
3897 -- Rewrite the occurrence of the formal into an occurrence of
3898 -- the actual. Also establish visibility on the proper view of
3899 -- the actual's subtype for the body's context (if the actual's
3900 -- subtype is private at the call point but its full view is
3901 -- visible to the body, then the inlined tree here must be
3902 -- analyzed with the full view).
3904 if Is_Entity_Name (A) then
3905 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
3906 Check_Private_View (N);
3908 elsif Nkind (A) = N_Defining_Identifier then
3909 Rewrite (N, New_Occurrence_Of (A, Loc));
3910 Check_Private_View (N);
3915 Rewrite (N, New_Copy (A));
3921 elsif Is_Entity_Name (N)
3922 and then Present (Return_Object)
3923 and then Chars (N) = Chars (Return_Object)
3925 -- Occurrence within an extended return statement. The return
3926 -- object is local to the body been inlined, and thus the generic
3927 -- copy is not analyzed yet, so we match by name, and replace it
3928 -- with target of call.
3930 if Nkind (Targ) = N_Defining_Identifier then
3931 Rewrite (N, New_Occurrence_Of (Targ, Loc));
3933 Rewrite (N, New_Copy_Tree (Targ));
3938 elsif Nkind (N) = N_Simple_Return_Statement then
3939 if No (Expression (N)) then
3942 Make_Goto_Statement (Loc, Name => New_Copy (Lab_Id)));
3945 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
3946 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
3948 -- Function body is a single expression. No need for
3954 Num_Ret := Num_Ret + 1;
3958 -- Because of the presence of private types, the views of the
3959 -- expression and the context may be different, so place an
3960 -- unchecked conversion to the context type to avoid spurious
3961 -- errors, e.g. when the expression is a numeric literal and
3962 -- the context is private. If the expression is an aggregate,
3963 -- use a qualified expression, because an aggregate is not a
3964 -- legal argument of a conversion.
3966 if Nkind_In (Expression (N), N_Aggregate, N_Null) then
3968 Make_Qualified_Expression (Sloc (N),
3969 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
3970 Expression => Relocate_Node (Expression (N)));
3973 Unchecked_Convert_To
3974 (Ret_Type, Relocate_Node (Expression (N)));
3977 if Nkind (Targ) = N_Defining_Identifier then
3979 Make_Assignment_Statement (Loc,
3980 Name => New_Occurrence_Of (Targ, Loc),
3981 Expression => Ret));
3984 Make_Assignment_Statement (Loc,
3985 Name => New_Copy (Targ),
3986 Expression => Ret));
3989 Set_Assignment_OK (Name (N));
3991 if Present (Exit_Lab) then
3993 Make_Goto_Statement (Loc, Name => New_Copy (Lab_Id)));
3999 -- An extended return becomes a block whose first statement is the
4000 -- assignment of the initial expression of the return object to the
4001 -- target of the call itself.
4003 elsif Nkind (N) = N_Extended_Return_Statement then
4005 Return_Decl : constant Entity_Id :=
4006 First (Return_Object_Declarations (N));
4010 Return_Object := Defining_Identifier (Return_Decl);
4012 if Present (Expression (Return_Decl)) then
4013 if Nkind (Targ) = N_Defining_Identifier then
4015 Make_Assignment_Statement (Loc,
4016 Name => New_Occurrence_Of (Targ, Loc),
4017 Expression => Expression (Return_Decl));
4020 Make_Assignment_Statement (Loc,
4021 Name => New_Copy (Targ),
4022 Expression => Expression (Return_Decl));
4025 Set_Assignment_OK (Name (Assign));
4027 Statements (Handled_Statement_Sequence (N)));
4031 Make_Block_Statement (Loc,
4032 Handled_Statement_Sequence =>
4033 Handled_Statement_Sequence (N)));
4038 -- Remove pragma Unreferenced since it may refer to formals that
4039 -- are not visible in the inlined body, and in any case we will
4040 -- not be posting warnings on the inlined body so it is unneeded.
4042 elsif Nkind (N) = N_Pragma
4043 and then Pragma_Name (N) = Name_Unreferenced
4045 Rewrite (N, Make_Null_Statement (Sloc (N)));
4051 end Process_Formals;
4053 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
4059 function Process_Sloc (Nod : Node_Id) return Traverse_Result is
4061 if not Debug_Generated_Code then
4062 Set_Sloc (Nod, Sloc (N));
4063 Set_Comes_From_Source (Nod, False);
4069 procedure Reset_Slocs is new Traverse_Proc (Process_Sloc);
4071 ---------------------------
4072 -- Rewrite_Function_Call --
4073 ---------------------------
4075 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
4076 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
4077 Fst : constant Node_Id := First (Statements (HSS));
4080 -- Optimize simple case: function body is a single return statement,
4081 -- which has been expanded into an assignment.
4083 if Is_Empty_List (Declarations (Blk))
4084 and then Nkind (Fst) = N_Assignment_Statement
4085 and then No (Next (Fst))
4087 -- The function call may have been rewritten as the temporary
4088 -- that holds the result of the call, in which case remove the
4089 -- now useless declaration.
4091 if Nkind (N) = N_Identifier
4092 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
4094 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
4097 Rewrite (N, Expression (Fst));
4099 elsif Nkind (N) = N_Identifier
4100 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
4102 -- The block assigns the result of the call to the temporary
4104 Insert_After (Parent (Entity (N)), Blk);
4106 -- If the context is an assignment, and the left-hand side is free of
4107 -- side-effects, the replacement is also safe.
4108 -- Can this be generalized further???
4110 elsif Nkind (Parent (N)) = N_Assignment_Statement
4112 (Is_Entity_Name (Name (Parent (N)))
4114 (Nkind (Name (Parent (N))) = N_Explicit_Dereference
4115 and then Is_Entity_Name (Prefix (Name (Parent (N)))))
4118 (Nkind (Name (Parent (N))) = N_Selected_Component
4119 and then Is_Entity_Name (Prefix (Name (Parent (N))))))
4121 -- Replace assignment with the block
4124 Original_Assignment : constant Node_Id := Parent (N);
4127 -- Preserve the original assignment node to keep the complete
4128 -- assignment subtree consistent enough for Analyze_Assignment
4129 -- to proceed (specifically, the original Lhs node must still
4130 -- have an assignment statement as its parent).
4132 -- We cannot rely on Original_Node to go back from the block
4133 -- node to the assignment node, because the assignment might
4134 -- already be a rewrite substitution.
4136 Discard_Node (Relocate_Node (Original_Assignment));
4137 Rewrite (Original_Assignment, Blk);
4140 elsif Nkind (Parent (N)) = N_Object_Declaration then
4141 Set_Expression (Parent (N), Empty);
4142 Insert_After (Parent (N), Blk);
4145 Insert_Before (Parent (N), Blk);
4147 end Rewrite_Function_Call;
4149 ----------------------------
4150 -- Rewrite_Procedure_Call --
4151 ----------------------------
4153 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
4154 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
4157 -- If there is a transient scope for N, this will be the scope of the
4158 -- actions for N, and the statements in Blk need to be within this
4159 -- scope. For example, they need to have visibility on the constant
4160 -- declarations created for the formals.
4162 -- If N needs no transient scope, and if there are no declarations in
4163 -- the inlined body, we can do a little optimization and insert the
4164 -- statements for the body directly after N, and rewrite N to a
4165 -- null statement, instead of rewriting N into a full-blown block
4168 if not Scope_Is_Transient
4169 and then Is_Empty_List (Declarations (Blk))
4171 Insert_List_After (N, Statements (HSS));
4172 Rewrite (N, Make_Null_Statement (Loc));
4176 end Rewrite_Procedure_Call;
4178 -------------------------
4179 -- Formal_Is_Used_Once --
4180 -------------------------
4182 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean is
4183 Use_Counter : Int := 0;
4185 function Count_Uses (N : Node_Id) return Traverse_Result;
4186 -- Traverse the tree and count the uses of the formal parameter.
4187 -- In this case, for optimization purposes, we do not need to
4188 -- continue the traversal once more than one use is encountered.
4194 function Count_Uses (N : Node_Id) return Traverse_Result is
4196 -- The original node is an identifier
4198 if Nkind (N) = N_Identifier
4199 and then Present (Entity (N))
4201 -- Original node's entity points to the one in the copied body
4203 and then Nkind (Entity (N)) = N_Identifier
4204 and then Present (Entity (Entity (N)))
4206 -- The entity of the copied node is the formal parameter
4208 and then Entity (Entity (N)) = Formal
4210 Use_Counter := Use_Counter + 1;
4212 if Use_Counter > 1 then
4214 -- Denote more than one use and abandon the traversal
4225 procedure Count_Formal_Uses is new Traverse_Proc (Count_Uses);
4227 -- Start of processing for Formal_Is_Used_Once
4230 Count_Formal_Uses (Orig_Bod);
4231 return Use_Counter = 1;
4232 end Formal_Is_Used_Once;
4234 -- Start of processing for Expand_Inlined_Call
4237 -- Check for an illegal attempt to inline a recursive procedure. If the
4238 -- subprogram has parameters this is detected when trying to supply a
4239 -- binding for parameters that already have one. For parameterless
4240 -- subprograms this must be done explicitly.
4242 if In_Open_Scopes (Subp) then
4243 Error_Msg_N ("call to recursive subprogram cannot be inlined?", N);
4244 Set_Is_Inlined (Subp, False);
4248 if Nkind (Orig_Bod) = N_Defining_Identifier
4249 or else Nkind (Orig_Bod) = N_Defining_Operator_Symbol
4251 -- Subprogram is renaming_as_body. Calls occurring after the renaming
4252 -- can be replaced with calls to the renamed entity directly, because
4253 -- the subprograms are subtype conformant. If the renamed subprogram
4254 -- is an inherited operation, we must redo the expansion because
4255 -- implicit conversions may be needed. Similarly, if the renamed
4256 -- entity is inlined, expand the call for further optimizations.
4258 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
4260 if Present (Alias (Orig_Bod)) or else Is_Inlined (Orig_Bod) then
4267 -- Use generic machinery to copy body of inlined subprogram, as if it
4268 -- were an instantiation, resetting source locations appropriately, so
4269 -- that nested inlined calls appear in the main unit.
4271 Save_Env (Subp, Empty);
4272 Set_Copied_Sloc_For_Inlined_Body (N, Defining_Entity (Orig_Bod));
4274 Bod := Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
4276 Make_Block_Statement (Loc,
4277 Declarations => Declarations (Bod),
4278 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
4280 if No (Declarations (Bod)) then
4281 Set_Declarations (Blk, New_List);
4284 -- For the unconstrained case, capture the name of the local variable
4285 -- that holds the result. This must be the first declaration in the
4286 -- block, because its bounds cannot depend on local variables. Otherwise
4287 -- there is no way to declare the result outside of the block. Needless
4288 -- to say, in general the bounds will depend on the actuals in the call.
4290 -- If the context is an assignment statement, as is the case for the
4291 -- expansion of an extended return, the left-hand side provides bounds
4292 -- even if the return type is unconstrained.
4295 if Nkind (Parent (N)) /= N_Assignment_Statement then
4296 Targ1 := Defining_Identifier (First (Declarations (Blk)));
4298 Targ1 := Name (Parent (N));
4302 -- If this is a derived function, establish the proper return type
4304 if Present (Orig_Subp) and then Orig_Subp /= Subp then
4305 Ret_Type := Etype (Orig_Subp);
4307 Ret_Type := Etype (Subp);
4310 -- Create temporaries for the actuals that are expressions, or that
4311 -- are scalars and require copying to preserve semantics.
4313 F := First_Formal (Subp);
4314 A := First_Actual (N);
4315 while Present (F) loop
4316 if Present (Renamed_Object (F)) then
4317 Error_Msg_N ("cannot inline call to recursive subprogram", N);
4321 -- If the argument may be a controlling argument in a call within
4322 -- the inlined body, we must preserve its classwide nature to insure
4323 -- that dynamic dispatching take place subsequently. If the formal
4324 -- has a constraint it must be preserved to retain the semantics of
4327 if Is_Class_Wide_Type (Etype (F))
4328 or else (Is_Access_Type (Etype (F))
4329 and then Is_Class_Wide_Type (Designated_Type (Etype (F))))
4331 Temp_Typ := Etype (F);
4333 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
4334 and then Etype (F) /= Base_Type (Etype (F))
4336 Temp_Typ := Etype (F);
4338 Temp_Typ := Etype (A);
4341 -- If the actual is a simple name or a literal, no need to
4342 -- create a temporary, object can be used directly.
4344 -- If the actual is a literal and the formal has its address taken,
4345 -- we cannot pass the literal itself as an argument, so its value
4346 -- must be captured in a temporary.
4348 if (Is_Entity_Name (A)
4350 (not Is_Scalar_Type (Etype (A))
4351 or else Ekind (Entity (A)) = E_Enumeration_Literal))
4353 -- When the actual is an identifier and the corresponding formal
4354 -- is used only once in the original body, the formal can be
4355 -- substituted directly with the actual parameter.
4357 or else (Nkind (A) = N_Identifier
4358 and then Formal_Is_Used_Once (F))
4361 (Nkind_In (A, N_Real_Literal,
4363 N_Character_Literal)
4364 and then not Address_Taken (F))
4366 if Etype (F) /= Etype (A) then
4368 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
4370 Set_Renamed_Object (F, A);
4374 Temp := Make_Temporary (Loc, 'C');
4376 -- If the actual for an in/in-out parameter is a view conversion,
4377 -- make it into an unchecked conversion, given that an untagged
4378 -- type conversion is not a proper object for a renaming.
4380 -- In-out conversions that involve real conversions have already
4381 -- been transformed in Expand_Actuals.
4383 if Nkind (A) = N_Type_Conversion
4384 and then Ekind (F) /= E_In_Parameter
4387 Make_Unchecked_Type_Conversion (Loc,
4388 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
4389 Expression => Relocate_Node (Expression (A)));
4391 elsif Etype (F) /= Etype (A) then
4392 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
4393 Temp_Typ := Etype (F);
4396 New_A := Relocate_Node (A);
4399 Set_Sloc (New_A, Sloc (N));
4401 -- If the actual has a by-reference type, it cannot be copied, so
4402 -- its value is captured in a renaming declaration. Otherwise
4403 -- declare a local constant initialized with the actual.
4405 -- We also use a renaming declaration for expressions of an array
4406 -- type that is not bit-packed, both for efficiency reasons and to
4407 -- respect the semantics of the call: in most cases the original
4408 -- call will pass the parameter by reference, and thus the inlined
4409 -- code will have the same semantics.
4411 if Ekind (F) = E_In_Parameter
4412 and then not Is_By_Reference_Type (Etype (A))
4414 (not Is_Array_Type (Etype (A))
4415 or else not Is_Object_Reference (A)
4416 or else Is_Bit_Packed_Array (Etype (A)))
4419 Make_Object_Declaration (Loc,
4420 Defining_Identifier => Temp,
4421 Constant_Present => True,
4422 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
4423 Expression => New_A);
4426 Make_Object_Renaming_Declaration (Loc,
4427 Defining_Identifier => Temp,
4428 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
4432 Append (Decl, Decls);
4433 Set_Renamed_Object (F, Temp);
4440 -- Establish target of function call. If context is not assignment or
4441 -- declaration, create a temporary as a target. The declaration for the
4442 -- temporary may be subsequently optimized away if the body is a single
4443 -- expression, or if the left-hand side of the assignment is simple
4444 -- enough, i.e. an entity or an explicit dereference of one.
4446 if Ekind (Subp) = E_Function then
4447 if Nkind (Parent (N)) = N_Assignment_Statement
4448 and then Is_Entity_Name (Name (Parent (N)))
4450 Targ := Name (Parent (N));
4452 elsif Nkind (Parent (N)) = N_Assignment_Statement
4453 and then Nkind (Name (Parent (N))) = N_Explicit_Dereference
4454 and then Is_Entity_Name (Prefix (Name (Parent (N))))
4456 Targ := Name (Parent (N));
4458 elsif Nkind (Parent (N)) = N_Assignment_Statement
4459 and then Nkind (Name (Parent (N))) = N_Selected_Component
4460 and then Is_Entity_Name (Prefix (Name (Parent (N))))
4462 Targ := New_Copy_Tree (Name (Parent (N)));
4464 elsif Nkind (Parent (N)) = N_Object_Declaration
4465 and then Is_Limited_Type (Etype (Subp))
4467 Targ := Defining_Identifier (Parent (N));
4470 -- Replace call with temporary and create its declaration
4472 Temp := Make_Temporary (Loc, 'C');
4473 Set_Is_Internal (Temp);
4475 -- For the unconstrained case, the generated temporary has the
4476 -- same constrained declaration as the result variable. It may
4477 -- eventually be possible to remove that temporary and use the
4478 -- result variable directly.
4481 and then Nkind (Parent (N)) /= N_Assignment_Statement
4484 Make_Object_Declaration (Loc,
4485 Defining_Identifier => Temp,
4486 Object_Definition =>
4487 New_Copy_Tree (Object_Definition (Parent (Targ1))));
4489 Replace_Formals (Decl);
4493 Make_Object_Declaration (Loc,
4494 Defining_Identifier => Temp,
4495 Object_Definition => New_Occurrence_Of (Ret_Type, Loc));
4497 Set_Etype (Temp, Ret_Type);
4500 Set_No_Initialization (Decl);
4501 Append (Decl, Decls);
4502 Rewrite (N, New_Occurrence_Of (Temp, Loc));
4507 Insert_Actions (N, Decls);
4509 -- Traverse the tree and replace formals with actuals or their thunks.
4510 -- Attach block to tree before analysis and rewriting.
4512 Replace_Formals (Blk);
4513 Set_Parent (Blk, N);
4515 if not Comes_From_Source (Subp) or else Is_Predef then
4519 if Present (Exit_Lab) then
4521 -- If the body was a single expression, the single return statement
4522 -- and the corresponding label are useless.
4526 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
4529 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
4531 Append (Lab_Decl, (Declarations (Blk)));
4532 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
4536 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
4537 -- conflicting private views that Gigi would ignore. If this is a
4538 -- predefined unit, analyze with checks off, as is done in the non-
4539 -- inlined run-time units.
4542 I_Flag : constant Boolean := In_Inlined_Body;
4545 In_Inlined_Body := True;
4549 Style : constant Boolean := Style_Check;
4551 Style_Check := False;
4552 Analyze (Blk, Suppress => All_Checks);
4553 Style_Check := Style;
4560 In_Inlined_Body := I_Flag;
4563 if Ekind (Subp) = E_Procedure then
4564 Rewrite_Procedure_Call (N, Blk);
4567 Rewrite_Function_Call (N, Blk);
4569 -- For the unconstrained case, the replacement of the call has been
4570 -- made prior to the complete analysis of the generated declarations.
4571 -- Propagate the proper type now.
4574 if Nkind (N) = N_Identifier then
4575 Set_Etype (N, Etype (Entity (N)));
4577 Set_Etype (N, Etype (Targ1));
4584 -- Cleanup mapping between formals and actuals for other expansions
4586 F := First_Formal (Subp);
4587 while Present (F) loop
4588 Set_Renamed_Object (F, Empty);
4591 end Expand_Inlined_Call;
4593 ----------------------------------------
4594 -- Expand_N_Extended_Return_Statement --
4595 ----------------------------------------
4597 -- If there is a Handled_Statement_Sequence, we rewrite this:
4599 -- return Result : T := <expression> do
4600 -- <handled_seq_of_stms>
4606 -- Result : T := <expression>;
4608 -- <handled_seq_of_stms>
4612 -- Otherwise (no Handled_Statement_Sequence), we rewrite this:
4614 -- return Result : T := <expression>;
4618 -- return <expression>;
4620 -- unless it's build-in-place or there's no <expression>, in which case
4624 -- Result : T := <expression>;
4629 -- Note that this case could have been written by the user as an extended
4630 -- return statement, or could have been transformed to this from a simple
4631 -- return statement.
4633 -- That is, we need to have a reified return object if there are statements
4634 -- (which might refer to it) or if we're doing build-in-place (so we can
4635 -- set its address to the final resting place or if there is no expression
4636 -- (in which case default initial values might need to be set).
4638 procedure Expand_N_Extended_Return_Statement (N : Node_Id) is
4639 Loc : constant Source_Ptr := Sloc (N);
4641 Par_Func : constant Entity_Id :=
4642 Return_Applies_To (Return_Statement_Entity (N));
4643 Result_Subt : constant Entity_Id := Etype (Par_Func);
4644 Ret_Obj_Id : constant Entity_Id :=
4645 First_Entity (Return_Statement_Entity (N));
4646 Ret_Obj_Decl : constant Node_Id := Parent (Ret_Obj_Id);
4648 Is_Build_In_Place : constant Boolean :=
4649 Is_Build_In_Place_Function (Par_Func);
4654 Return_Stmt : Node_Id;
4657 function Build_Heap_Allocator
4658 (Temp_Id : Entity_Id;
4659 Temp_Typ : Entity_Id;
4660 Func_Id : Entity_Id;
4661 Ret_Typ : Entity_Id;
4662 Alloc_Expr : Node_Id) return Node_Id;
4663 -- Create the statements necessary to allocate a return object on the
4664 -- caller's master. The master is available through implicit parameter
4665 -- BIPfinalizationmaster.
4667 -- if BIPfinalizationmaster /= null then
4669 -- type Ptr_Typ is access Ret_Typ;
4670 -- for Ptr_Typ'Storage_Pool use
4671 -- Base_Pool (BIPfinalizationmaster.all).all;
4675 -- procedure Allocate (...) is
4677 -- System.Storage_Pools.Subpools.Allocate_Any (...);
4680 -- Local := <Alloc_Expr>;
4681 -- Temp_Id := Temp_Typ (Local);
4685 -- Temp_Id is the temporary which is used to reference the internally
4686 -- created object in all allocation forms. Temp_Typ is the type of the
4687 -- temporary. Func_Id is the enclosing function. Ret_Typ is the return
4688 -- type of Func_Id. Alloc_Expr is the actual allocator.
4690 function Move_Activation_Chain return Node_Id;
4691 -- Construct a call to System.Tasking.Stages.Move_Activation_Chain
4693 -- From current activation chain
4694 -- To activation chain passed in by the caller
4695 -- New_Master master passed in by the caller
4697 --------------------------
4698 -- Build_Heap_Allocator --
4699 --------------------------
4701 function Build_Heap_Allocator
4702 (Temp_Id : Entity_Id;
4703 Temp_Typ : Entity_Id;
4704 Func_Id : Entity_Id;
4705 Ret_Typ : Entity_Id;
4706 Alloc_Expr : Node_Id) return Node_Id
4709 pragma Assert (Is_Build_In_Place_Function (Func_Id));
4711 -- Processing for build-in-place object allocation. This is disabled
4712 -- on .NET/JVM because the targets do not support pools.
4714 if VM_Target = No_VM
4715 and then Needs_Finalization (Ret_Typ)
4718 Decls : constant List_Id := New_List;
4719 Fin_Mas_Id : constant Entity_Id :=
4720 Build_In_Place_Formal
4721 (Func_Id, BIP_Finalization_Master);
4722 Stmts : constant List_Id := New_List;
4723 Desig_Typ : Entity_Id;
4724 Local_Id : Entity_Id;
4725 Pool_Id : Entity_Id;
4726 Ptr_Typ : Entity_Id;
4730 -- Pool_Id renames Base_Pool (BIPfinalizationmaster.all).all;
4732 Pool_Id := Make_Temporary (Loc, 'P');
4735 Make_Object_Renaming_Declaration (Loc,
4736 Defining_Identifier => Pool_Id,
4738 New_Reference_To (RTE (RE_Root_Storage_Pool), Loc),
4740 Make_Explicit_Dereference (Loc,
4742 Make_Function_Call (Loc,
4744 New_Reference_To (RTE (RE_Base_Pool), Loc),
4745 Parameter_Associations => New_List (
4746 Make_Explicit_Dereference (Loc,
4748 New_Reference_To (Fin_Mas_Id, Loc)))))));
4750 -- Create an access type which uses the storage pool of the
4751 -- caller's master. This additional type is necessary because
4752 -- the finalization master cannot be associated with the type
4753 -- of the temporary. Otherwise the secondary stack allocation
4756 Desig_Typ := Ret_Typ;
4758 -- Ensure that the build-in-place machinery uses a fat pointer
4759 -- when allocating an unconstrained array on the heap. In this
4760 -- case the result object type is a constrained array type even
4761 -- though the function type is unconstrained.
4763 if Ekind (Desig_Typ) = E_Array_Subtype then
4764 Desig_Typ := Base_Type (Desig_Typ);
4768 -- type Ptr_Typ is access Desig_Typ;
4770 Ptr_Typ := Make_Temporary (Loc, 'P');
4773 Make_Full_Type_Declaration (Loc,
4774 Defining_Identifier => Ptr_Typ,
4776 Make_Access_To_Object_Definition (Loc,
4777 Subtype_Indication =>
4778 New_Reference_To (Desig_Typ, Loc))));
4780 -- Perform minor decoration in order to set the master and the
4781 -- storage pool attributes.
4783 Set_Ekind (Ptr_Typ, E_Access_Type);
4784 Set_Finalization_Master (Ptr_Typ, Fin_Mas_Id);
4785 Set_Associated_Storage_Pool (Ptr_Typ, Pool_Id);
4787 -- Create the temporary, generate:
4788 -- Local_Id : Ptr_Typ;
4790 Local_Id := Make_Temporary (Loc, 'T');
4793 Make_Object_Declaration (Loc,
4794 Defining_Identifier => Local_Id,
4795 Object_Definition =>
4796 New_Reference_To (Ptr_Typ, Loc)));
4798 -- Allocate the object, generate:
4799 -- Local_Id := <Alloc_Expr>;
4802 Make_Assignment_Statement (Loc,
4803 Name => New_Reference_To (Local_Id, Loc),
4804 Expression => Alloc_Expr));
4807 -- Temp_Id := Temp_Typ (Local_Id);
4810 Make_Assignment_Statement (Loc,
4811 Name => New_Reference_To (Temp_Id, Loc),
4813 Unchecked_Convert_To (Temp_Typ,
4814 New_Reference_To (Local_Id, Loc))));
4816 -- Wrap the allocation in a block. This is further conditioned
4817 -- by checking the caller finalization master at runtime. A
4818 -- null value indicates a non-existent master, most likely due
4819 -- to a Finalize_Storage_Only allocation.
4822 -- if BIPfinalizationmaster /= null then
4831 Make_If_Statement (Loc,
4834 Left_Opnd => New_Reference_To (Fin_Mas_Id, Loc),
4835 Right_Opnd => Make_Null (Loc)),
4837 Then_Statements => New_List (
4838 Make_Block_Statement (Loc,
4839 Declarations => Decls,
4840 Handled_Statement_Sequence =>
4841 Make_Handled_Sequence_Of_Statements (Loc,
4842 Statements => Stmts))));
4845 -- For all other cases, generate:
4846 -- Temp_Id := <Alloc_Expr>;
4850 Make_Assignment_Statement (Loc,
4851 Name => New_Reference_To (Temp_Id, Loc),
4852 Expression => Alloc_Expr);
4854 end Build_Heap_Allocator;
4856 ---------------------------
4857 -- Move_Activation_Chain --
4858 ---------------------------
4860 function Move_Activation_Chain return Node_Id is
4863 Make_Procedure_Call_Statement (Loc,
4865 New_Reference_To (RTE (RE_Move_Activation_Chain), Loc),
4867 Parameter_Associations => New_List (
4871 Make_Attribute_Reference (Loc,
4872 Prefix => Make_Identifier (Loc, Name_uChain),
4873 Attribute_Name => Name_Unrestricted_Access),
4875 -- Destination chain
4878 (Build_In_Place_Formal (Par_Func, BIP_Activation_Chain), Loc),
4883 (Build_In_Place_Formal (Par_Func, BIP_Task_Master), Loc)));
4884 end Move_Activation_Chain;
4886 -- Start of processing for Expand_N_Extended_Return_Statement
4889 if Nkind (Ret_Obj_Decl) = N_Object_Declaration then
4890 Exp := Expression (Ret_Obj_Decl);
4895 HSS := Handled_Statement_Sequence (N);
4897 -- If the returned object needs finalization actions, the function must
4898 -- perform the appropriate cleanup should it fail to return. The state
4899 -- of the function itself is tracked through a flag which is coupled
4900 -- with the scope finalizer. There is one flag per each return object
4901 -- in case of multiple returns.
4903 if Is_Build_In_Place
4904 and then Needs_Finalization (Etype (Ret_Obj_Id))
4907 Flag_Decl : Node_Id;
4908 Flag_Id : Entity_Id;
4912 -- Recover the function body
4914 Func_Bod := Unit_Declaration_Node (Par_Func);
4916 if Nkind (Func_Bod) = N_Subprogram_Declaration then
4917 Func_Bod := Parent (Parent (Corresponding_Body (Func_Bod)));
4920 -- Create a flag to track the function state
4922 Flag_Id := Make_Temporary (Loc, 'F');
4923 Set_Return_Flag_Or_Transient_Decl (Ret_Obj_Id, Flag_Id);
4925 -- Insert the flag at the beginning of the function declarations,
4927 -- Fnn : Boolean := False;
4930 Make_Object_Declaration (Loc,
4931 Defining_Identifier => Flag_Id,
4932 Object_Definition =>
4933 New_Reference_To (Standard_Boolean, Loc),
4934 Expression => New_Reference_To (Standard_False, Loc));
4936 Prepend_To (Declarations (Func_Bod), Flag_Decl);
4937 Analyze (Flag_Decl);
4941 -- Build a simple_return_statement that returns the return object when
4942 -- there is a statement sequence, or no expression, or the result will
4943 -- be built in place. Note however that we currently do this for all
4944 -- composite cases, even though nonlimited composite results are not yet
4945 -- built in place (though we plan to do so eventually).
4948 or else Is_Composite_Type (Result_Subt)
4954 -- If the extended return has a handled statement sequence, then wrap
4955 -- it in a block and use the block as the first statement.
4959 Make_Block_Statement (Loc,
4960 Declarations => New_List,
4961 Handled_Statement_Sequence => HSS));
4964 -- If the result type contains tasks, we call Move_Activation_Chain.
4965 -- Later, the cleanup code will call Complete_Master, which will
4966 -- terminate any unactivated tasks belonging to the return statement
4967 -- master. But Move_Activation_Chain updates their master to be that
4968 -- of the caller, so they will not be terminated unless the return
4969 -- statement completes unsuccessfully due to exception, abort, goto,
4970 -- or exit. As a formality, we test whether the function requires the
4971 -- result to be built in place, though that's necessarily true for
4972 -- the case of result types with task parts.
4974 if Is_Build_In_Place
4975 and then Has_Task (Result_Subt)
4977 -- The return expression is an aggregate for a complex type which
4978 -- contains tasks. This particular case is left unexpanded since
4979 -- the regular expansion would insert all temporaries and
4980 -- initialization code in the wrong block.
4982 if Nkind (Exp) = N_Aggregate then
4983 Expand_N_Aggregate (Exp);
4986 -- Do not move the activation chain if the return object does not
4989 if Has_Task (Etype (Ret_Obj_Id)) then
4990 Append_To (Stmts, Move_Activation_Chain);
4994 -- Update the state of the function right before the object is
4997 if Is_Build_In_Place
4998 and then Needs_Finalization (Etype (Ret_Obj_Id))
5001 Flag_Id : constant Entity_Id :=
5002 Return_Flag_Or_Transient_Decl (Ret_Obj_Id);
5009 Make_Assignment_Statement (Loc,
5010 Name => New_Reference_To (Flag_Id, Loc),
5011 Expression => New_Reference_To (Standard_True, Loc)));
5015 -- Build a simple_return_statement that returns the return object
5018 Make_Simple_Return_Statement (Loc,
5019 Expression => New_Occurrence_Of (Ret_Obj_Id, Loc));
5020 Append_To (Stmts, Return_Stmt);
5022 HSS := Make_Handled_Sequence_Of_Statements (Loc, Stmts);
5025 -- Case where we build a return statement block
5027 if Present (HSS) then
5029 Make_Block_Statement (Loc,
5030 Declarations => Return_Object_Declarations (N),
5031 Handled_Statement_Sequence => HSS);
5033 -- We set the entity of the new block statement to be that of the
5034 -- return statement. This is necessary so that various fields, such
5035 -- as Finalization_Chain_Entity carry over from the return statement
5036 -- to the block. Note that this block is unusual, in that its entity
5037 -- is an E_Return_Statement rather than an E_Block.
5040 (Result, New_Occurrence_Of (Return_Statement_Entity (N), Loc));
5042 -- If the object decl was already rewritten as a renaming, then we
5043 -- don't want to do the object allocation and transformation of of
5044 -- the return object declaration to a renaming. This case occurs
5045 -- when the return object is initialized by a call to another
5046 -- build-in-place function, and that function is responsible for
5047 -- the allocation of the return object.
5049 if Is_Build_In_Place
5050 and then Nkind (Ret_Obj_Decl) = N_Object_Renaming_Declaration
5053 (Nkind (Original_Node (Ret_Obj_Decl)) = N_Object_Declaration
5054 and then Is_Build_In_Place_Function_Call
5055 (Expression (Original_Node (Ret_Obj_Decl))));
5057 -- Return the build-in-place result by reference
5059 Set_By_Ref (Return_Stmt);
5061 elsif Is_Build_In_Place then
5063 -- Locate the implicit access parameter associated with the
5064 -- caller-supplied return object and convert the return
5065 -- statement's return object declaration to a renaming of a
5066 -- dereference of the access parameter. If the return object's
5067 -- declaration includes an expression that has not already been
5068 -- expanded as separate assignments, then add an assignment
5069 -- statement to ensure the return object gets initialized.
5072 -- Result : T [:= <expression>];
5079 -- Result : T renames FuncRA.all;
5080 -- [Result := <expression;]
5085 Return_Obj_Id : constant Entity_Id :=
5086 Defining_Identifier (Ret_Obj_Decl);
5087 Return_Obj_Typ : constant Entity_Id := Etype (Return_Obj_Id);
5088 Return_Obj_Expr : constant Node_Id :=
5089 Expression (Ret_Obj_Decl);
5090 Constr_Result : constant Boolean :=
5091 Is_Constrained (Result_Subt);
5092 Obj_Alloc_Formal : Entity_Id;
5093 Object_Access : Entity_Id;
5094 Obj_Acc_Deref : Node_Id;
5095 Init_Assignment : Node_Id := Empty;
5098 -- Build-in-place results must be returned by reference
5100 Set_By_Ref (Return_Stmt);
5102 -- Retrieve the implicit access parameter passed by the caller
5105 Build_In_Place_Formal (Par_Func, BIP_Object_Access);
5107 -- If the return object's declaration includes an expression
5108 -- and the declaration isn't marked as No_Initialization, then
5109 -- we need to generate an assignment to the object and insert
5110 -- it after the declaration before rewriting it as a renaming
5111 -- (otherwise we'll lose the initialization). The case where
5112 -- the result type is an interface (or class-wide interface)
5113 -- is also excluded because the context of the function call
5114 -- must be unconstrained, so the initialization will always
5115 -- be done as part of an allocator evaluation (storage pool
5116 -- or secondary stack), never to a constrained target object
5117 -- passed in by the caller. Besides the assignment being
5118 -- unneeded in this case, it avoids problems with trying to
5119 -- generate a dispatching assignment when the return expression
5120 -- is a nonlimited descendant of a limited interface (the
5121 -- interface has no assignment operation).
5123 if Present (Return_Obj_Expr)
5124 and then not No_Initialization (Ret_Obj_Decl)
5125 and then not Is_Interface (Return_Obj_Typ)
5128 Make_Assignment_Statement (Loc,
5129 Name => New_Reference_To (Return_Obj_Id, Loc),
5130 Expression => Relocate_Node (Return_Obj_Expr));
5132 Set_Etype (Name (Init_Assignment), Etype (Return_Obj_Id));
5133 Set_Assignment_OK (Name (Init_Assignment));
5134 Set_No_Ctrl_Actions (Init_Assignment);
5136 Set_Parent (Name (Init_Assignment), Init_Assignment);
5137 Set_Parent (Expression (Init_Assignment), Init_Assignment);
5139 Set_Expression (Ret_Obj_Decl, Empty);
5141 if Is_Class_Wide_Type (Etype (Return_Obj_Id))
5142 and then not Is_Class_Wide_Type
5143 (Etype (Expression (Init_Assignment)))
5145 Rewrite (Expression (Init_Assignment),
5146 Make_Type_Conversion (Loc,
5148 New_Occurrence_Of (Etype (Return_Obj_Id), Loc),
5150 Relocate_Node (Expression (Init_Assignment))));
5153 -- In the case of functions where the calling context can
5154 -- determine the form of allocation needed, initialization
5155 -- is done with each part of the if statement that handles
5156 -- the different forms of allocation (this is true for
5157 -- unconstrained and tagged result subtypes).
5160 and then not Is_Tagged_Type (Underlying_Type (Result_Subt))
5162 Insert_After (Ret_Obj_Decl, Init_Assignment);
5166 -- When the function's subtype is unconstrained, a run-time
5167 -- test is needed to determine the form of allocation to use
5168 -- for the return object. The function has an implicit formal
5169 -- parameter indicating this. If the BIP_Alloc_Form formal has
5170 -- the value one, then the caller has passed access to an
5171 -- existing object for use as the return object. If the value
5172 -- is two, then the return object must be allocated on the
5173 -- secondary stack. Otherwise, the object must be allocated in
5174 -- a storage pool (currently only supported for the global
5175 -- heap, user-defined storage pools TBD ???). We generate an
5176 -- if statement to test the implicit allocation formal and
5177 -- initialize a local access value appropriately, creating
5178 -- allocators in the secondary stack and global heap cases.
5179 -- The special formal also exists and must be tested when the
5180 -- function has a tagged result, even when the result subtype
5181 -- is constrained, because in general such functions can be
5182 -- called in dispatching contexts and must be handled similarly
5183 -- to functions with a class-wide result.
5185 if not Constr_Result
5186 or else Is_Tagged_Type (Underlying_Type (Result_Subt))
5189 Build_In_Place_Formal (Par_Func, BIP_Alloc_Form);
5192 Pool_Id : constant Entity_Id :=
5193 Make_Temporary (Loc, 'P');
5194 Alloc_Obj_Id : Entity_Id;
5195 Alloc_Obj_Decl : Node_Id;
5196 Alloc_If_Stmt : Node_Id;
5197 Heap_Allocator : Node_Id;
5198 Pool_Decl : Node_Id;
5199 Pool_Allocator : Node_Id;
5200 Ptr_Type_Decl : Node_Id;
5201 Ref_Type : Entity_Id;
5202 SS_Allocator : Node_Id;
5205 -- Reuse the itype created for the function's implicit
5206 -- access formal. This avoids the need to create a new
5207 -- access type here, plus it allows assigning the access
5208 -- formal directly without applying a conversion.
5210 -- Ref_Type := Etype (Object_Access);
5212 -- Create an access type designating the function's
5215 Ref_Type := Make_Temporary (Loc, 'A');
5218 Make_Full_Type_Declaration (Loc,
5219 Defining_Identifier => Ref_Type,
5221 Make_Access_To_Object_Definition (Loc,
5222 All_Present => True,
5223 Subtype_Indication =>
5224 New_Reference_To (Return_Obj_Typ, Loc)));
5226 Insert_Before (Ret_Obj_Decl, Ptr_Type_Decl);
5228 -- Create an access object that will be initialized to an
5229 -- access value denoting the return object, either coming
5230 -- from an implicit access value passed in by the caller
5231 -- or from the result of an allocator.
5233 Alloc_Obj_Id := Make_Temporary (Loc, 'R');
5234 Set_Etype (Alloc_Obj_Id, Ref_Type);
5237 Make_Object_Declaration (Loc,
5238 Defining_Identifier => Alloc_Obj_Id,
5239 Object_Definition =>
5240 New_Reference_To (Ref_Type, Loc));
5242 Insert_Before (Ret_Obj_Decl, Alloc_Obj_Decl);
5244 -- Create allocators for both the secondary stack and
5245 -- global heap. If there's an initialization expression,
5246 -- then create these as initialized allocators.
5248 if Present (Return_Obj_Expr)
5249 and then not No_Initialization (Ret_Obj_Decl)
5251 -- Always use the type of the expression for the
5252 -- qualified expression, rather than the result type.
5253 -- In general we cannot always use the result type
5254 -- for the allocator, because the expression might be
5255 -- of a specific type, such as in the case of an
5256 -- aggregate or even a nonlimited object when the
5257 -- result type is a limited class-wide interface type.
5260 Make_Allocator (Loc,
5262 Make_Qualified_Expression (Loc,
5265 (Etype (Return_Obj_Expr), Loc),
5267 New_Copy_Tree (Return_Obj_Expr)));
5270 -- If the function returns a class-wide type we cannot
5271 -- use the return type for the allocator. Instead we
5272 -- use the type of the expression, which must be an
5273 -- aggregate of a definite type.
5275 if Is_Class_Wide_Type (Return_Obj_Typ) then
5277 Make_Allocator (Loc,
5280 (Etype (Return_Obj_Expr), Loc));
5283 Make_Allocator (Loc,
5285 New_Reference_To (Return_Obj_Typ, Loc));
5288 -- If the object requires default initialization then
5289 -- that will happen later following the elaboration of
5290 -- the object renaming. If we don't turn it off here
5291 -- then the object will be default initialized twice.
5293 Set_No_Initialization (Heap_Allocator);
5296 -- The Pool_Allocator is just like the Heap_Allocator,
5297 -- except we set Storage_Pool and Procedure_To_Call so
5298 -- it will use the user-defined storage pool.
5300 Pool_Allocator := New_Copy_Tree (Heap_Allocator);
5302 -- Do not generate the renaming of the build-in-place
5303 -- pool parameter on .NET/JVM/ZFP because the parameter
5304 -- is not created in the first place.
5306 if VM_Target = No_VM
5307 and then RTE_Available (RE_Root_Storage_Pool_Ptr)
5310 Make_Object_Renaming_Declaration (Loc,
5311 Defining_Identifier => Pool_Id,
5314 (RTE (RE_Root_Storage_Pool), Loc),
5316 Make_Explicit_Dereference (Loc,
5318 (Build_In_Place_Formal
5319 (Par_Func, BIP_Storage_Pool), Loc)));
5320 Set_Storage_Pool (Pool_Allocator, Pool_Id);
5321 Set_Procedure_To_Call
5322 (Pool_Allocator, RTE (RE_Allocate_Any));
5324 Pool_Decl := Make_Null_Statement (Loc);
5327 -- If the No_Allocators restriction is active, then only
5328 -- an allocator for secondary stack allocation is needed.
5329 -- It's OK for such allocators to have Comes_From_Source
5330 -- set to False, because gigi knows not to flag them as
5331 -- being a violation of No_Implicit_Heap_Allocations.
5333 if Restriction_Active (No_Allocators) then
5334 SS_Allocator := Heap_Allocator;
5335 Heap_Allocator := Make_Null (Loc);
5336 Pool_Allocator := Make_Null (Loc);
5338 -- Otherwise the heap and pool allocators may be needed,
5339 -- so we make another allocator for secondary stack
5343 SS_Allocator := New_Copy_Tree (Heap_Allocator);
5345 -- The heap and pool allocators are marked as
5346 -- Comes_From_Source since they correspond to an
5347 -- explicit user-written allocator (that is, it will
5348 -- only be executed on behalf of callers that call the
5349 -- function as initialization for such an allocator).
5350 -- Prevents errors when No_Implicit_Heap_Allocations
5353 Set_Comes_From_Source (Heap_Allocator, True);
5354 Set_Comes_From_Source (Pool_Allocator, True);
5357 -- The allocator is returned on the secondary stack. We
5358 -- don't do this on VM targets, since the SS is not used.
5360 if VM_Target = No_VM then
5361 Set_Storage_Pool (SS_Allocator, RTE (RE_SS_Pool));
5362 Set_Procedure_To_Call
5363 (SS_Allocator, RTE (RE_SS_Allocate));
5365 -- The allocator is returned on the secondary stack,
5366 -- so indicate that the function return, as well as
5367 -- the block that encloses the allocator, must not
5368 -- release it. The flags must be set now because
5369 -- the decision to use the secondary stack is done
5370 -- very late in the course of expanding the return
5371 -- statement, past the point where these flags are
5374 Set_Sec_Stack_Needed_For_Return (Par_Func);
5375 Set_Sec_Stack_Needed_For_Return
5376 (Return_Statement_Entity (N));
5377 Set_Uses_Sec_Stack (Par_Func);
5378 Set_Uses_Sec_Stack (Return_Statement_Entity (N));
5381 -- Create an if statement to test the BIP_Alloc_Form
5382 -- formal and initialize the access object to either the
5383 -- BIP_Object_Access formal (BIP_Alloc_Form =
5384 -- Caller_Allocation), the result of allocating the
5385 -- object in the secondary stack (BIP_Alloc_Form =
5386 -- Secondary_Stack), or else an allocator to create the
5387 -- return object in the heap or user-defined pool
5388 -- (BIP_Alloc_Form = Global_Heap or User_Storage_Pool).
5390 -- ??? An unchecked type conversion must be made in the
5391 -- case of assigning the access object formal to the
5392 -- local access object, because a normal conversion would
5393 -- be illegal in some cases (such as converting access-
5394 -- to-unconstrained to access-to-constrained), but the
5395 -- the unchecked conversion will presumably fail to work
5396 -- right in just such cases. It's not clear at all how to
5400 Make_If_Statement (Loc,
5404 New_Reference_To (Obj_Alloc_Formal, Loc),
5406 Make_Integer_Literal (Loc,
5407 UI_From_Int (BIP_Allocation_Form'Pos
5408 (Caller_Allocation)))),
5410 Then_Statements => New_List (
5411 Make_Assignment_Statement (Loc,
5413 New_Reference_To (Alloc_Obj_Id, Loc),
5415 Make_Unchecked_Type_Conversion (Loc,
5417 New_Reference_To (Ref_Type, Loc),
5419 New_Reference_To (Object_Access, Loc)))),
5421 Elsif_Parts => New_List (
5422 Make_Elsif_Part (Loc,
5426 New_Reference_To (Obj_Alloc_Formal, Loc),
5428 Make_Integer_Literal (Loc,
5429 UI_From_Int (BIP_Allocation_Form'Pos
5430 (Secondary_Stack)))),
5432 Then_Statements => New_List (
5433 Make_Assignment_Statement (Loc,
5435 New_Reference_To (Alloc_Obj_Id, Loc),
5436 Expression => SS_Allocator))),
5438 Make_Elsif_Part (Loc,
5442 New_Reference_To (Obj_Alloc_Formal, Loc),
5444 Make_Integer_Literal (Loc,
5445 UI_From_Int (BIP_Allocation_Form'Pos
5448 Then_Statements => New_List (
5449 Build_Heap_Allocator
5450 (Temp_Id => Alloc_Obj_Id,
5451 Temp_Typ => Ref_Type,
5452 Func_Id => Par_Func,
5453 Ret_Typ => Return_Obj_Typ,
5454 Alloc_Expr => Heap_Allocator)))),
5456 Else_Statements => New_List (
5458 Build_Heap_Allocator
5459 (Temp_Id => Alloc_Obj_Id,
5460 Temp_Typ => Ref_Type,
5461 Func_Id => Par_Func,
5462 Ret_Typ => Return_Obj_Typ,
5463 Alloc_Expr => Pool_Allocator)));
5465 -- If a separate initialization assignment was created
5466 -- earlier, append that following the assignment of the
5467 -- implicit access formal to the access object, to ensure
5468 -- that the return object is initialized in that case. In
5469 -- this situation, the target of the assignment must be
5470 -- rewritten to denote a dereference of the access to the
5471 -- return object passed in by the caller.
5473 if Present (Init_Assignment) then
5474 Rewrite (Name (Init_Assignment),
5475 Make_Explicit_Dereference (Loc,
5476 Prefix => New_Reference_To (Alloc_Obj_Id, Loc)));
5479 (Name (Init_Assignment), Etype (Return_Obj_Id));
5482 (Then_Statements (Alloc_If_Stmt), Init_Assignment);
5485 Insert_Before (Ret_Obj_Decl, Alloc_If_Stmt);
5487 -- Remember the local access object for use in the
5488 -- dereference of the renaming created below.
5490 Object_Access := Alloc_Obj_Id;
5494 -- Replace the return object declaration with a renaming of a
5495 -- dereference of the access value designating the return
5499 Make_Explicit_Dereference (Loc,
5500 Prefix => New_Reference_To (Object_Access, Loc));
5502 Rewrite (Ret_Obj_Decl,
5503 Make_Object_Renaming_Declaration (Loc,
5504 Defining_Identifier => Return_Obj_Id,
5505 Access_Definition => Empty,
5507 New_Occurrence_Of (Return_Obj_Typ, Loc),
5508 Name => Obj_Acc_Deref));
5510 Set_Renamed_Object (Return_Obj_Id, Obj_Acc_Deref);
5514 -- Case where we do not build a block
5517 -- We're about to drop Return_Object_Declarations on the floor, so
5518 -- we need to insert it, in case it got expanded into useful code.
5519 -- Remove side effects from expression, which may be duplicated in
5520 -- subsequent checks (see Expand_Simple_Function_Return).
5522 Insert_List_Before (N, Return_Object_Declarations (N));
5523 Remove_Side_Effects (Exp);
5525 -- Build simple_return_statement that returns the expression directly
5527 Return_Stmt := Make_Simple_Return_Statement (Loc, Expression => Exp);
5528 Result := Return_Stmt;
5531 -- Set the flag to prevent infinite recursion
5533 Set_Comes_From_Extended_Return_Statement (Return_Stmt);
5535 Rewrite (N, Result);
5537 end Expand_N_Extended_Return_Statement;
5539 ----------------------------
5540 -- Expand_N_Function_Call --
5541 ----------------------------
5543 procedure Expand_N_Function_Call (N : Node_Id) is
5547 -- If the return value of a foreign compiled function is VAX Float, then
5548 -- expand the return (adjusts the location of the return value on
5549 -- Alpha/VMS, no-op everywhere else).
5550 -- Comes_From_Source intercepts recursive expansion.
5552 if Vax_Float (Etype (N))
5553 and then Nkind (N) = N_Function_Call
5554 and then Present (Name (N))
5555 and then Present (Entity (Name (N)))
5556 and then Has_Foreign_Convention (Entity (Name (N)))
5557 and then Comes_From_Source (Parent (N))
5559 Expand_Vax_Foreign_Return (N);
5561 end Expand_N_Function_Call;
5563 ---------------------------------------
5564 -- Expand_N_Procedure_Call_Statement --
5565 ---------------------------------------
5567 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
5570 end Expand_N_Procedure_Call_Statement;
5572 --------------------------------------
5573 -- Expand_N_Simple_Return_Statement --
5574 --------------------------------------
5576 procedure Expand_N_Simple_Return_Statement (N : Node_Id) is
5578 -- Defend against previous errors (i.e. the return statement calls a
5579 -- function that is not available in configurable runtime).
5581 if Present (Expression (N))
5582 and then Nkind (Expression (N)) = N_Empty
5587 -- Distinguish the function and non-function cases:
5589 case Ekind (Return_Applies_To (Return_Statement_Entity (N))) is
5592 E_Generic_Function =>
5593 Expand_Simple_Function_Return (N);
5596 E_Generic_Procedure |
5599 E_Return_Statement =>
5600 Expand_Non_Function_Return (N);
5603 raise Program_Error;
5607 when RE_Not_Available =>
5609 end Expand_N_Simple_Return_Statement;
5611 ------------------------------
5612 -- Expand_N_Subprogram_Body --
5613 ------------------------------
5615 -- Add poll call if ATC polling is enabled, unless the body will be inlined
5618 -- Add dummy push/pop label nodes at start and end to clear any local
5619 -- exception indications if local-exception-to-goto optimization is active.
5621 -- Add return statement if last statement in body is not a return statement
5622 -- (this makes things easier on Gigi which does not want to have to handle
5623 -- a missing return).
5625 -- Add call to Activate_Tasks if body is a task activator
5627 -- Deal with possible detection of infinite recursion
5629 -- Eliminate body completely if convention stubbed
5631 -- Encode entity names within body, since we will not need to reference
5632 -- these entities any longer in the front end.
5634 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
5636 -- Reset Pure indication if any parameter has root type System.Address
5637 -- or has any parameters of limited types, where limited means that the
5638 -- run-time view is limited (i.e. the full type is limited).
5642 procedure Expand_N_Subprogram_Body (N : Node_Id) is
5643 Loc : constant Source_Ptr := Sloc (N);
5644 H : constant Node_Id := Handled_Statement_Sequence (N);
5645 Body_Id : Entity_Id;
5648 Spec_Id : Entity_Id;
5650 procedure Add_Return (S : List_Id);
5651 -- Append a return statement to the statement sequence S if the last
5652 -- statement is not already a return or a goto statement. Note that
5653 -- the latter test is not critical, it does not matter if we add a few
5654 -- extra returns, since they get eliminated anyway later on.
5660 procedure Add_Return (S : List_Id) is
5665 -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
5666 -- not relevant in this context since they are not executable.
5668 Last_Stm := Last (S);
5669 while Nkind (Last_Stm) in N_Pop_xxx_Label loop
5673 -- Now insert return unless last statement is a transfer
5675 if not Is_Transfer (Last_Stm) then
5677 -- The source location for the return is the end label of the
5678 -- procedure if present. Otherwise use the sloc of the last
5679 -- statement in the list. If the list comes from a generated
5680 -- exception handler and we are not debugging generated code,
5681 -- all the statements within the handler are made invisible
5684 if Nkind (Parent (S)) = N_Exception_Handler
5685 and then not Comes_From_Source (Parent (S))
5687 Loc := Sloc (Last_Stm);
5688 elsif Present (End_Label (H)) then
5689 Loc := Sloc (End_Label (H));
5691 Loc := Sloc (Last_Stm);
5695 Rtn : constant Node_Id := Make_Simple_Return_Statement (Loc);
5698 -- Append return statement, and set analyzed manually. We can't
5699 -- call Analyze on this return since the scope is wrong.
5701 -- Note: it almost works to push the scope and then do the
5702 -- Analyze call, but something goes wrong in some weird cases
5703 -- and it is not worth worrying about ???
5708 -- Call _Postconditions procedure if appropriate. We need to
5709 -- do this explicitly because we did not analyze the generated
5710 -- return statement above, so the call did not get inserted.
5712 if Ekind (Spec_Id) = E_Procedure
5713 and then Has_Postconditions (Spec_Id)
5715 pragma Assert (Present (Postcondition_Proc (Spec_Id)));
5717 Make_Procedure_Call_Statement (Loc,
5719 New_Reference_To (Postcondition_Proc (Spec_Id), Loc)));
5725 -- Start of processing for Expand_N_Subprogram_Body
5728 -- Set L to either the list of declarations if present, or to the list
5729 -- of statements if no declarations are present. This is used to insert
5730 -- new stuff at the start.
5732 if Is_Non_Empty_List (Declarations (N)) then
5733 L := Declarations (N);
5735 L := Statements (H);
5738 -- If local-exception-to-goto optimization active, insert dummy push
5739 -- statements at start, and dummy pop statements at end, but inhibit
5740 -- this if we have No_Exception_Handlers, since they are useless and
5741 -- intefere with analysis, e.g. by codepeer.
5743 if (Debug_Flag_Dot_G
5744 or else Restriction_Active (No_Exception_Propagation))
5745 and then not Restriction_Active (No_Exception_Handlers)
5746 and then not CodePeer_Mode
5747 and then Is_Non_Empty_List (L)
5750 FS : constant Node_Id := First (L);
5751 FL : constant Source_Ptr := Sloc (FS);
5756 -- LS points to either last statement, if statements are present
5757 -- or to the last declaration if there are no statements present.
5758 -- It is the node after which the pop's are generated.
5760 if Is_Non_Empty_List (Statements (H)) then
5761 LS := Last (Statements (H));
5768 Insert_List_Before_And_Analyze (FS, New_List (
5769 Make_Push_Constraint_Error_Label (FL),
5770 Make_Push_Program_Error_Label (FL),
5771 Make_Push_Storage_Error_Label (FL)));
5773 Insert_List_After_And_Analyze (LS, New_List (
5774 Make_Pop_Constraint_Error_Label (LL),
5775 Make_Pop_Program_Error_Label (LL),
5776 Make_Pop_Storage_Error_Label (LL)));
5780 -- Find entity for subprogram
5782 Body_Id := Defining_Entity (N);
5784 if Present (Corresponding_Spec (N)) then
5785 Spec_Id := Corresponding_Spec (N);
5790 -- Need poll on entry to subprogram if polling enabled. We only do this
5791 -- for non-empty subprograms, since it does not seem necessary to poll
5792 -- for a dummy null subprogram.
5794 if Is_Non_Empty_List (L) then
5796 -- Do not add a polling call if the subprogram is to be inlined by
5797 -- the back-end, to avoid repeated calls with multiple inlinings.
5799 if Is_Inlined (Spec_Id)
5800 and then Front_End_Inlining
5801 and then Optimization_Level > 1
5805 Generate_Poll_Call (First (L));
5809 -- If this is a Pure function which has any parameters whose root type
5810 -- is System.Address, reset the Pure indication, since it will likely
5811 -- cause incorrect code to be generated as the parameter is probably
5812 -- a pointer, and the fact that the same pointer is passed does not mean
5813 -- that the same value is being referenced.
5815 -- Note that if the programmer gave an explicit Pure_Function pragma,
5816 -- then we believe the programmer, and leave the subprogram Pure.
5818 -- This code should probably be at the freeze point, so that it happens
5819 -- even on a -gnatc (or more importantly -gnatt) compile, so that the
5820 -- semantic tree has Is_Pure set properly ???
5822 if Is_Pure (Spec_Id)
5823 and then Is_Subprogram (Spec_Id)
5824 and then not Has_Pragma_Pure_Function (Spec_Id)
5830 F := First_Formal (Spec_Id);
5831 while Present (F) loop
5832 if Is_Descendent_Of_Address (Etype (F))
5834 -- Note that this test is being made in the body of the
5835 -- subprogram, not the spec, so we are testing the full
5836 -- type for being limited here, as required.
5838 or else Is_Limited_Type (Etype (F))
5840 Set_Is_Pure (Spec_Id, False);
5842 if Spec_Id /= Body_Id then
5843 Set_Is_Pure (Body_Id, False);
5854 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
5856 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
5861 -- Loop through formals
5863 F := First_Formal (Spec_Id);
5864 while Present (F) loop
5865 if Is_Scalar_Type (Etype (F))
5866 and then Ekind (F) = E_Out_Parameter
5868 Check_Restriction (No_Default_Initialization, F);
5870 -- Insert the initialization. We turn off validity checks
5871 -- for this assignment, since we do not want any check on
5872 -- the initial value itself (which may well be invalid).
5874 Insert_Before_And_Analyze (First (L),
5875 Make_Assignment_Statement (Loc,
5876 Name => New_Occurrence_Of (F, Loc),
5877 Expression => Get_Simple_Init_Val (Etype (F), N)),
5878 Suppress => Validity_Check);
5886 -- Clear out statement list for stubbed procedure
5888 if Present (Corresponding_Spec (N)) then
5889 Set_Elaboration_Flag (N, Spec_Id);
5891 if Convention (Spec_Id) = Convention_Stubbed
5892 or else Is_Eliminated (Spec_Id)
5894 Set_Declarations (N, Empty_List);
5895 Set_Handled_Statement_Sequence (N,
5896 Make_Handled_Sequence_Of_Statements (Loc,
5897 Statements => New_List (Make_Null_Statement (Loc))));
5902 -- Create a set of discriminals for the next protected subprogram body
5904 if Is_List_Member (N)
5905 and then Present (Parent (List_Containing (N)))
5906 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
5907 and then Present (Next_Protected_Operation (N))
5909 Set_Discriminals (Parent (Base_Type (Scope (Spec_Id))));
5912 -- Returns_By_Ref flag is normally set when the subprogram is frozen but
5913 -- subprograms with no specs are not frozen.
5916 Typ : constant Entity_Id := Etype (Spec_Id);
5917 Utyp : constant Entity_Id := Underlying_Type (Typ);
5920 if not Acts_As_Spec (N)
5921 and then Nkind (Parent (Parent (Spec_Id))) /=
5922 N_Subprogram_Body_Stub
5926 elsif Is_Immutably_Limited_Type (Typ) then
5927 Set_Returns_By_Ref (Spec_Id);
5929 elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
5930 Set_Returns_By_Ref (Spec_Id);
5934 -- For a procedure, we add a return for all possible syntactic ends of
5937 if Ekind_In (Spec_Id, E_Procedure, E_Generic_Procedure) then
5938 Add_Return (Statements (H));
5940 if Present (Exception_Handlers (H)) then
5941 Except_H := First_Non_Pragma (Exception_Handlers (H));
5942 while Present (Except_H) loop
5943 Add_Return (Statements (Except_H));
5944 Next_Non_Pragma (Except_H);
5948 -- For a function, we must deal with the case where there is at least
5949 -- one missing return. What we do is to wrap the entire body of the
5950 -- function in a block:
5963 -- raise Program_Error;
5966 -- This approach is necessary because the raise must be signalled to the
5967 -- caller, not handled by any local handler (RM 6.4(11)).
5969 -- Note: we do not need to analyze the constructed sequence here, since
5970 -- it has no handler, and an attempt to analyze the handled statement
5971 -- sequence twice is risky in various ways (e.g. the issue of expanding
5972 -- cleanup actions twice).
5974 elsif Has_Missing_Return (Spec_Id) then
5976 Hloc : constant Source_Ptr := Sloc (H);
5977 Blok : constant Node_Id :=
5978 Make_Block_Statement (Hloc,
5979 Handled_Statement_Sequence => H);
5980 Rais : constant Node_Id :=
5981 Make_Raise_Program_Error (Hloc,
5982 Reason => PE_Missing_Return);
5985 Set_Handled_Statement_Sequence (N,
5986 Make_Handled_Sequence_Of_Statements (Hloc,
5987 Statements => New_List (Blok, Rais)));
5989 Push_Scope (Spec_Id);
5996 -- If subprogram contains a parameterless recursive call, then we may
5997 -- have an infinite recursion, so see if we can generate code to check
5998 -- for this possibility if storage checks are not suppressed.
6000 if Ekind (Spec_Id) = E_Procedure
6001 and then Has_Recursive_Call (Spec_Id)
6002 and then not Storage_Checks_Suppressed (Spec_Id)
6004 Detect_Infinite_Recursion (N, Spec_Id);
6007 -- Set to encode entity names in package body before gigi is called
6009 Qualify_Entity_Names (N);
6010 end Expand_N_Subprogram_Body;
6012 -----------------------------------
6013 -- Expand_N_Subprogram_Body_Stub --
6014 -----------------------------------
6016 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
6018 if Present (Corresponding_Body (N)) then
6019 Expand_N_Subprogram_Body (
6020 Unit_Declaration_Node (Corresponding_Body (N)));
6022 end Expand_N_Subprogram_Body_Stub;
6024 -------------------------------------
6025 -- Expand_N_Subprogram_Declaration --
6026 -------------------------------------
6028 -- If the declaration appears within a protected body, it is a private
6029 -- operation of the protected type. We must create the corresponding
6030 -- protected subprogram an associated formals. For a normal protected
6031 -- operation, this is done when expanding the protected type declaration.
6033 -- If the declaration is for a null procedure, emit null body
6035 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
6036 Loc : constant Source_Ptr := Sloc (N);
6037 Subp : constant Entity_Id := Defining_Entity (N);
6038 Scop : constant Entity_Id := Scope (Subp);
6039 Prot_Decl : Node_Id;
6041 Prot_Id : Entity_Id;
6044 -- In SPARK, subprogram declarations are only allowed in package
6047 if Nkind (Parent (N)) /= N_Package_Specification then
6048 if Nkind (Parent (N)) = N_Compilation_Unit then
6049 Check_SPARK_Restriction
6050 ("subprogram declaration is not a library item", N);
6052 elsif Present (Next (N))
6053 and then Nkind (Next (N)) = N_Pragma
6054 and then Get_Pragma_Id (Pragma_Name (Next (N))) = Pragma_Import
6056 -- In SPARK, subprogram declarations are also permitted in
6057 -- declarative parts when immediately followed by a corresponding
6058 -- pragma Import. We only check here that there is some pragma
6063 Check_SPARK_Restriction
6064 ("subprogram declaration is not allowed here", N);
6068 -- Deal with case of protected subprogram. Do not generate protected
6069 -- operation if operation is flagged as eliminated.
6071 if Is_List_Member (N)
6072 and then Present (Parent (List_Containing (N)))
6073 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
6074 and then Is_Protected_Type (Scop)
6076 if No (Protected_Body_Subprogram (Subp))
6077 and then not Is_Eliminated (Subp)
6080 Make_Subprogram_Declaration (Loc,
6082 Build_Protected_Sub_Specification
6083 (N, Scop, Unprotected_Mode));
6085 -- The protected subprogram is declared outside of the protected
6086 -- body. Given that the body has frozen all entities so far, we
6087 -- analyze the subprogram and perform freezing actions explicitly.
6088 -- including the generation of an explicit freeze node, to ensure
6089 -- that gigi has the proper order of elaboration.
6090 -- If the body is a subunit, the insertion point is before the
6091 -- stub in the parent.
6093 Prot_Bod := Parent (List_Containing (N));
6095 if Nkind (Parent (Prot_Bod)) = N_Subunit then
6096 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
6099 Insert_Before (Prot_Bod, Prot_Decl);
6100 Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
6101 Set_Has_Delayed_Freeze (Prot_Id);
6103 Push_Scope (Scope (Scop));
6104 Analyze (Prot_Decl);
6105 Freeze_Before (N, Prot_Id);
6106 Set_Protected_Body_Subprogram (Subp, Prot_Id);
6108 -- Create protected operation as well. Even though the operation
6109 -- is only accessible within the body, it is possible to make it
6110 -- available outside of the protected object by using 'Access to
6111 -- provide a callback, so build protected version in all cases.
6114 Make_Subprogram_Declaration (Loc,
6116 Build_Protected_Sub_Specification (N, Scop, Protected_Mode));
6117 Insert_Before (Prot_Bod, Prot_Decl);
6118 Analyze (Prot_Decl);
6123 -- Ada 2005 (AI-348): Generate body for a null procedure. In most
6124 -- cases this is superfluous because calls to it will be automatically
6125 -- inlined, but we definitely need the body if preconditions for the
6126 -- procedure are present.
6128 elsif Nkind (Specification (N)) = N_Procedure_Specification
6129 and then Null_Present (Specification (N))
6132 Bod : constant Node_Id := Body_To_Inline (N);
6135 Set_Has_Completion (Subp, False);
6136 Append_Freeze_Action (Subp, Bod);
6138 -- The body now contains raise statements, so calls to it will
6141 Set_Is_Inlined (Subp, False);
6144 end Expand_N_Subprogram_Declaration;
6146 --------------------------------
6147 -- Expand_Non_Function_Return --
6148 --------------------------------
6150 procedure Expand_Non_Function_Return (N : Node_Id) is
6151 pragma Assert (No (Expression (N)));
6153 Loc : constant Source_Ptr := Sloc (N);
6154 Scope_Id : Entity_Id :=
6155 Return_Applies_To (Return_Statement_Entity (N));
6156 Kind : constant Entity_Kind := Ekind (Scope_Id);
6159 Goto_Stat : Node_Id;
6163 -- Call _Postconditions procedure if procedure with active
6164 -- postconditions. Here, we use the Postcondition_Proc attribute,
6165 -- which is needed for implicitly-generated returns. Functions
6166 -- never have implicitly-generated returns, and there's no
6167 -- room for Postcondition_Proc in E_Function, so we look up the
6168 -- identifier Name_uPostconditions for function returns (see
6169 -- Expand_Simple_Function_Return).
6171 if Ekind (Scope_Id) = E_Procedure
6172 and then Has_Postconditions (Scope_Id)
6174 pragma Assert (Present (Postcondition_Proc (Scope_Id)));
6176 Make_Procedure_Call_Statement (Loc,
6177 Name => New_Reference_To (Postcondition_Proc (Scope_Id), Loc)));
6180 -- If it is a return from a procedure do no extra steps
6182 if Kind = E_Procedure or else Kind = E_Generic_Procedure then
6185 -- If it is a nested return within an extended one, replace it with a
6186 -- return of the previously declared return object.
6188 elsif Kind = E_Return_Statement then
6190 Make_Simple_Return_Statement (Loc,
6192 New_Occurrence_Of (First_Entity (Scope_Id), Loc)));
6193 Set_Comes_From_Extended_Return_Statement (N);
6194 Set_Return_Statement_Entity (N, Scope_Id);
6195 Expand_Simple_Function_Return (N);
6199 pragma Assert (Is_Entry (Scope_Id));
6201 -- Look at the enclosing block to see whether the return is from an
6202 -- accept statement or an entry body.
6204 for J in reverse 0 .. Scope_Stack.Last loop
6205 Scope_Id := Scope_Stack.Table (J).Entity;
6206 exit when Is_Concurrent_Type (Scope_Id);
6209 -- If it is a return from accept statement it is expanded as call to
6210 -- RTS Complete_Rendezvous and a goto to the end of the accept body.
6212 -- (cf : Expand_N_Accept_Statement, Expand_N_Selective_Accept,
6213 -- Expand_N_Accept_Alternative in exp_ch9.adb)
6215 if Is_Task_Type (Scope_Id) then
6218 Make_Procedure_Call_Statement (Loc,
6219 Name => New_Reference_To (RTE (RE_Complete_Rendezvous), Loc));
6220 Insert_Before (N, Call);
6221 -- why not insert actions here???
6224 Acc_Stat := Parent (N);
6225 while Nkind (Acc_Stat) /= N_Accept_Statement loop
6226 Acc_Stat := Parent (Acc_Stat);
6229 Lab_Node := Last (Statements
6230 (Handled_Statement_Sequence (Acc_Stat)));
6232 Goto_Stat := Make_Goto_Statement (Loc,
6233 Name => New_Occurrence_Of
6234 (Entity (Identifier (Lab_Node)), Loc));
6236 Set_Analyzed (Goto_Stat);
6238 Rewrite (N, Goto_Stat);
6241 -- If it is a return from an entry body, put a Complete_Entry_Body call
6242 -- in front of the return.
6244 elsif Is_Protected_Type (Scope_Id) then
6246 Make_Procedure_Call_Statement (Loc,
6248 New_Reference_To (RTE (RE_Complete_Entry_Body), Loc),
6249 Parameter_Associations => New_List (
6250 Make_Attribute_Reference (Loc,
6253 (Find_Protection_Object (Current_Scope), Loc),
6254 Attribute_Name => Name_Unchecked_Access)));
6256 Insert_Before (N, Call);
6259 end Expand_Non_Function_Return;
6261 ---------------------------------------
6262 -- Expand_Protected_Object_Reference --
6263 ---------------------------------------
6265 function Expand_Protected_Object_Reference
6267 Scop : Entity_Id) return Node_Id
6269 Loc : constant Source_Ptr := Sloc (N);
6276 Rec := Make_Identifier (Loc, Name_uObject);
6277 Set_Etype (Rec, Corresponding_Record_Type (Scop));
6279 -- Find enclosing protected operation, and retrieve its first parameter,
6280 -- which denotes the enclosing protected object. If the enclosing
6281 -- operation is an entry, we are immediately within the protected body,
6282 -- and we can retrieve the object from the service entries procedure. A
6283 -- barrier function has the same signature as an entry. A barrier
6284 -- function is compiled within the protected object, but unlike
6285 -- protected operations its never needs locks, so that its protected
6286 -- body subprogram points to itself.
6288 Proc := Current_Scope;
6289 while Present (Proc)
6290 and then Scope (Proc) /= Scop
6292 Proc := Scope (Proc);
6295 Corr := Protected_Body_Subprogram (Proc);
6299 -- Previous error left expansion incomplete.
6300 -- Nothing to do on this call.
6307 (First (Parameter_Specifications (Parent (Corr))));
6309 if Is_Subprogram (Proc)
6310 and then Proc /= Corr
6312 -- Protected function or procedure
6314 Set_Entity (Rec, Param);
6316 -- Rec is a reference to an entity which will not be in scope when
6317 -- the call is reanalyzed, and needs no further analysis.
6322 -- Entry or barrier function for entry body. The first parameter of
6323 -- the entry body procedure is pointer to the object. We create a
6324 -- local variable of the proper type, duplicating what is done to
6325 -- define _object later on.
6329 Obj_Ptr : constant Entity_Id := Make_Temporary (Loc, 'T');
6333 Make_Full_Type_Declaration (Loc,
6334 Defining_Identifier => Obj_Ptr,
6336 Make_Access_To_Object_Definition (Loc,
6337 Subtype_Indication =>
6339 (Corresponding_Record_Type (Scop), Loc))));
6341 Insert_Actions (N, Decls);
6342 Freeze_Before (N, Obj_Ptr);
6345 Make_Explicit_Dereference (Loc,
6347 Unchecked_Convert_To (Obj_Ptr,
6348 New_Occurrence_Of (Param, Loc)));
6350 -- Analyze new actual. Other actuals in calls are already analyzed
6351 -- and the list of actuals is not reanalyzed after rewriting.
6353 Set_Parent (Rec, N);
6359 end Expand_Protected_Object_Reference;
6361 --------------------------------------
6362 -- Expand_Protected_Subprogram_Call --
6363 --------------------------------------
6365 procedure Expand_Protected_Subprogram_Call
6373 -- If the protected object is not an enclosing scope, this is an inter-
6374 -- object function call. Inter-object procedure calls are expanded by
6375 -- Exp_Ch9.Build_Simple_Entry_Call. The call is intra-object only if the
6376 -- subprogram being called is in the protected body being compiled, and
6377 -- if the protected object in the call is statically the enclosing type.
6378 -- The object may be an component of some other data structure, in which
6379 -- case this must be handled as an inter-object call.
6381 if not In_Open_Scopes (Scop)
6382 or else not Is_Entity_Name (Name (N))
6384 if Nkind (Name (N)) = N_Selected_Component then
6385 Rec := Prefix (Name (N));
6388 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
6389 Rec := Prefix (Prefix (Name (N)));
6392 Build_Protected_Subprogram_Call (N,
6393 Name => New_Occurrence_Of (Subp, Sloc (N)),
6394 Rec => Convert_Concurrent (Rec, Etype (Rec)),
6398 Rec := Expand_Protected_Object_Reference (N, Scop);
6404 Build_Protected_Subprogram_Call (N,
6411 -- If it is a function call it can appear in elaboration code and
6412 -- the called entity must be frozen here.
6414 if Ekind (Subp) = E_Function then
6415 Freeze_Expression (Name (N));
6418 -- Analyze and resolve the new call. The actuals have already been
6419 -- resolved, but expansion of a function call will add extra actuals
6420 -- if needed. Analysis of a procedure call already includes resolution.
6424 if Ekind (Subp) = E_Function then
6425 Resolve (N, Etype (Subp));
6427 end Expand_Protected_Subprogram_Call;
6429 --------------------------------------------
6430 -- Has_Unconstrained_Access_Discriminants --
6431 --------------------------------------------
6433 function Has_Unconstrained_Access_Discriminants
6434 (Subtyp : Entity_Id) return Boolean
6439 if Has_Discriminants (Subtyp)
6440 and then not Is_Constrained (Subtyp)
6442 Discr := First_Discriminant (Subtyp);
6443 while Present (Discr) loop
6444 if Ekind (Etype (Discr)) = E_Anonymous_Access_Type then
6448 Next_Discriminant (Discr);
6453 end Has_Unconstrained_Access_Discriminants;
6455 -----------------------------------
6456 -- Expand_Simple_Function_Return --
6457 -----------------------------------
6459 -- The "simple" comes from the syntax rule simple_return_statement. The
6460 -- semantics are not at all simple!
6462 procedure Expand_Simple_Function_Return (N : Node_Id) is
6463 Loc : constant Source_Ptr := Sloc (N);
6465 Scope_Id : constant Entity_Id :=
6466 Return_Applies_To (Return_Statement_Entity (N));
6467 -- The function we are returning from
6469 R_Type : constant Entity_Id := Etype (Scope_Id);
6470 -- The result type of the function
6472 Utyp : constant Entity_Id := Underlying_Type (R_Type);
6474 Exp : constant Node_Id := Expression (N);
6475 pragma Assert (Present (Exp));
6477 Exptyp : constant Entity_Id := Etype (Exp);
6478 -- The type of the expression (not necessarily the same as R_Type)
6480 Subtype_Ind : Node_Id;
6481 -- If the result type of the function is class-wide and the expression
6482 -- has a specific type, then we use the expression's type as the type of
6483 -- the return object. In cases where the expression is an aggregate that
6484 -- is built in place, this avoids the need for an expensive conversion
6485 -- of the return object to the specific type on assignments to the
6486 -- individual components.
6489 if Is_Class_Wide_Type (R_Type)
6490 and then not Is_Class_Wide_Type (Etype (Exp))
6492 Subtype_Ind := New_Occurrence_Of (Etype (Exp), Loc);
6494 Subtype_Ind := New_Occurrence_Of (R_Type, Loc);
6497 -- For the case of a simple return that does not come from an extended
6498 -- return, in the case of Ada 2005 where we are returning a limited
6499 -- type, we rewrite "return <expression>;" to be:
6501 -- return _anon_ : <return_subtype> := <expression>
6503 -- The expansion produced by Expand_N_Extended_Return_Statement will
6504 -- contain simple return statements (for example, a block containing
6505 -- simple return of the return object), which brings us back here with
6506 -- Comes_From_Extended_Return_Statement set. The reason for the barrier
6507 -- checking for a simple return that does not come from an extended
6508 -- return is to avoid this infinite recursion.
6510 -- The reason for this design is that for Ada 2005 limited returns, we
6511 -- need to reify the return object, so we can build it "in place", and
6512 -- we need a block statement to hang finalization and tasking stuff.
6514 -- ??? In order to avoid disruption, we avoid translating to extended
6515 -- return except in the cases where we really need to (Ada 2005 for
6516 -- inherently limited). We might prefer to do this translation in all
6517 -- cases (except perhaps for the case of Ada 95 inherently limited),
6518 -- in order to fully exercise the Expand_N_Extended_Return_Statement
6519 -- code. This would also allow us to do the build-in-place optimization
6520 -- for efficiency even in cases where it is semantically not required.
6522 -- As before, we check the type of the return expression rather than the
6523 -- return type of the function, because the latter may be a limited
6524 -- class-wide interface type, which is not a limited type, even though
6525 -- the type of the expression may be.
6527 if not Comes_From_Extended_Return_Statement (N)
6528 and then Is_Immutably_Limited_Type (Etype (Expression (N)))
6529 and then Ada_Version >= Ada_2005
6530 and then not Debug_Flag_Dot_L
6533 Return_Object_Entity : constant Entity_Id :=
6534 Make_Temporary (Loc, 'R', Exp);
6535 Obj_Decl : constant Node_Id :=
6536 Make_Object_Declaration (Loc,
6537 Defining_Identifier => Return_Object_Entity,
6538 Object_Definition => Subtype_Ind,
6541 Ext : constant Node_Id := Make_Extended_Return_Statement (Loc,
6542 Return_Object_Declarations => New_List (Obj_Decl));
6543 -- Do not perform this high-level optimization if the result type
6544 -- is an interface because the "this" pointer must be displaced.
6553 -- Here we have a simple return statement that is part of the expansion
6554 -- of an extended return statement (either written by the user, or
6555 -- generated by the above code).
6557 -- Always normalize C/Fortran boolean result. This is not always needed,
6558 -- but it seems a good idea to minimize the passing around of non-
6559 -- normalized values, and in any case this handles the processing of
6560 -- barrier functions for protected types, which turn the condition into
6561 -- a return statement.
6563 if Is_Boolean_Type (Exptyp)
6564 and then Nonzero_Is_True (Exptyp)
6566 Adjust_Condition (Exp);
6567 Adjust_Result_Type (Exp, Exptyp);
6570 -- Do validity check if enabled for returns
6572 if Validity_Checks_On
6573 and then Validity_Check_Returns
6578 -- Check the result expression of a scalar function against the subtype
6579 -- of the function by inserting a conversion. This conversion must
6580 -- eventually be performed for other classes of types, but for now it's
6581 -- only done for scalars.
6584 if Is_Scalar_Type (Exptyp) then
6585 Rewrite (Exp, Convert_To (R_Type, Exp));
6587 -- The expression is resolved to ensure that the conversion gets
6588 -- expanded to generate a possible constraint check.
6590 Analyze_And_Resolve (Exp, R_Type);
6593 -- Deal with returning variable length objects and controlled types
6595 -- Nothing to do if we are returning by reference, or this is not a
6596 -- type that requires special processing (indicated by the fact that
6597 -- it requires a cleanup scope for the secondary stack case).
6599 if Is_Immutably_Limited_Type (Exptyp)
6600 or else Is_Limited_Interface (Exptyp)
6604 elsif not Requires_Transient_Scope (R_Type) then
6606 -- Mutable records with no variable length components are not
6607 -- returned on the sec-stack, so we need to make sure that the
6608 -- backend will only copy back the size of the actual value, and not
6609 -- the maximum size. We create an actual subtype for this purpose.
6612 Ubt : constant Entity_Id := Underlying_Type (Base_Type (Exptyp));
6616 if Has_Discriminants (Ubt)
6617 and then not Is_Constrained (Ubt)
6618 and then not Has_Unchecked_Union (Ubt)
6620 Decl := Build_Actual_Subtype (Ubt, Exp);
6621 Ent := Defining_Identifier (Decl);
6622 Insert_Action (Exp, Decl);
6623 Rewrite (Exp, Unchecked_Convert_To (Ent, Exp));
6624 Analyze_And_Resolve (Exp);
6628 -- Here if secondary stack is used
6631 -- Make sure that no surrounding block will reclaim the secondary
6632 -- stack on which we are going to put the result. Not only may this
6633 -- introduce secondary stack leaks but worse, if the reclamation is
6634 -- done too early, then the result we are returning may get
6641 while Ekind (S) = E_Block or else Ekind (S) = E_Loop loop
6642 Set_Sec_Stack_Needed_For_Return (S, True);
6643 S := Enclosing_Dynamic_Scope (S);
6647 -- Optimize the case where the result is a function call. In this
6648 -- case either the result is already on the secondary stack, or is
6649 -- already being returned with the stack pointer depressed and no
6650 -- further processing is required except to set the By_Ref flag
6651 -- to ensure that gigi does not attempt an extra unnecessary copy.
6652 -- (actually not just unnecessary but harmfully wrong in the case
6653 -- of a controlled type, where gigi does not know how to do a copy).
6654 -- To make up for a gcc 2.8.1 deficiency (???), we perform the copy
6655 -- for array types if the constrained status of the target type is
6656 -- different from that of the expression.
6658 if Requires_Transient_Scope (Exptyp)
6660 (not Is_Array_Type (Exptyp)
6661 or else Is_Constrained (Exptyp) = Is_Constrained (R_Type)
6662 or else CW_Or_Has_Controlled_Part (Utyp))
6663 and then Nkind (Exp) = N_Function_Call
6667 -- Remove side effects from the expression now so that other parts
6668 -- of the expander do not have to reanalyze this node without this
6671 Rewrite (Exp, Duplicate_Subexpr_No_Checks (Exp));
6673 -- For controlled types, do the allocation on the secondary stack
6674 -- manually in order to call adjust at the right time:
6676 -- type Anon1 is access R_Type;
6677 -- for Anon1'Storage_pool use ss_pool;
6678 -- Anon2 : anon1 := new R_Type'(expr);
6679 -- return Anon2.all;
6681 -- We do the same for classwide types that are not potentially
6682 -- controlled (by the virtue of restriction No_Finalization) because
6683 -- gigi is not able to properly allocate class-wide types.
6685 elsif CW_Or_Has_Controlled_Part (Utyp) then
6687 Loc : constant Source_Ptr := Sloc (N);
6688 Acc_Typ : constant Entity_Id := Make_Temporary (Loc, 'A');
6689 Alloc_Node : Node_Id;
6693 Set_Ekind (Acc_Typ, E_Access_Type);
6695 Set_Associated_Storage_Pool (Acc_Typ, RTE (RE_SS_Pool));
6697 -- This is an allocator for the secondary stack, and it's fine
6698 -- to have Comes_From_Source set False on it, as gigi knows not
6699 -- to flag it as a violation of No_Implicit_Heap_Allocations.
6702 Make_Allocator (Loc,
6704 Make_Qualified_Expression (Loc,
6705 Subtype_Mark => New_Reference_To (Etype (Exp), Loc),
6706 Expression => Relocate_Node (Exp)));
6708 -- We do not want discriminant checks on the declaration,
6709 -- given that it gets its value from the allocator.
6711 Set_No_Initialization (Alloc_Node);
6713 Temp := Make_Temporary (Loc, 'R', Alloc_Node);
6715 Insert_List_Before_And_Analyze (N, New_List (
6716 Make_Full_Type_Declaration (Loc,
6717 Defining_Identifier => Acc_Typ,
6719 Make_Access_To_Object_Definition (Loc,
6720 Subtype_Indication => Subtype_Ind)),
6722 Make_Object_Declaration (Loc,
6723 Defining_Identifier => Temp,
6724 Object_Definition => New_Reference_To (Acc_Typ, Loc),
6725 Expression => Alloc_Node)));
6728 Make_Explicit_Dereference (Loc,
6729 Prefix => New_Reference_To (Temp, Loc)));
6731 -- Ada 2005 (AI-251): If the type of the returned object is
6732 -- an interface then add an implicit type conversion to force
6733 -- displacement of the "this" pointer.
6735 if Is_Interface (R_Type) then
6736 Rewrite (Exp, Convert_To (R_Type, Relocate_Node (Exp)));
6739 Analyze_And_Resolve (Exp, R_Type);
6742 -- Otherwise use the gigi mechanism to allocate result on the
6746 Check_Restriction (No_Secondary_Stack, N);
6747 Set_Storage_Pool (N, RTE (RE_SS_Pool));
6749 -- If we are generating code for the VM do not use
6750 -- SS_Allocate since everything is heap-allocated anyway.
6752 if VM_Target = No_VM then
6753 Set_Procedure_To_Call (N, RTE (RE_SS_Allocate));
6758 -- Implement the rules of 6.5(8-10), which require a tag check in
6759 -- the case of a limited tagged return type, and tag reassignment for
6760 -- nonlimited tagged results. These actions are needed when the return
6761 -- type is a specific tagged type and the result expression is a
6762 -- conversion or a formal parameter, because in that case the tag of
6763 -- the expression might differ from the tag of the specific result type.
6765 if Is_Tagged_Type (Utyp)
6766 and then not Is_Class_Wide_Type (Utyp)
6767 and then (Nkind_In (Exp, N_Type_Conversion,
6768 N_Unchecked_Type_Conversion)
6769 or else (Is_Entity_Name (Exp)
6770 and then Ekind (Entity (Exp)) in Formal_Kind))
6772 -- When the return type is limited, perform a check that the tag of
6773 -- the result is the same as the tag of the return type.
6775 if Is_Limited_Type (R_Type) then
6777 Make_Raise_Constraint_Error (Loc,
6781 Make_Selected_Component (Loc,
6782 Prefix => Duplicate_Subexpr (Exp),
6783 Selector_Name => Make_Identifier (Loc, Name_uTag)),
6785 Make_Attribute_Reference (Loc,
6787 New_Occurrence_Of (Base_Type (Utyp), Loc),
6788 Attribute_Name => Name_Tag)),
6789 Reason => CE_Tag_Check_Failed));
6791 -- If the result type is a specific nonlimited tagged type, then we
6792 -- have to ensure that the tag of the result is that of the result
6793 -- type. This is handled by making a copy of the expression in
6794 -- the case where it might have a different tag, namely when the
6795 -- expression is a conversion or a formal parameter. We create a new
6796 -- object of the result type and initialize it from the expression,
6797 -- which will implicitly force the tag to be set appropriately.
6801 ExpR : constant Node_Id := Relocate_Node (Exp);
6802 Result_Id : constant Entity_Id :=
6803 Make_Temporary (Loc, 'R', ExpR);
6804 Result_Exp : constant Node_Id :=
6805 New_Reference_To (Result_Id, Loc);
6806 Result_Obj : constant Node_Id :=
6807 Make_Object_Declaration (Loc,
6808 Defining_Identifier => Result_Id,
6809 Object_Definition =>
6810 New_Reference_To (R_Type, Loc),
6811 Constant_Present => True,
6812 Expression => ExpR);
6815 Set_Assignment_OK (Result_Obj);
6816 Insert_Action (Exp, Result_Obj);
6818 Rewrite (Exp, Result_Exp);
6819 Analyze_And_Resolve (Exp, R_Type);
6823 -- Ada 2005 (AI-344): If the result type is class-wide, then insert
6824 -- a check that the level of the return expression's underlying type
6825 -- is not deeper than the level of the master enclosing the function.
6826 -- Always generate the check when the type of the return expression
6827 -- is class-wide, when it's a type conversion, or when it's a formal
6828 -- parameter. Otherwise, suppress the check in the case where the
6829 -- return expression has a specific type whose level is known not to
6830 -- be statically deeper than the function's result type.
6832 -- Note: accessibility check is skipped in the VM case, since there
6833 -- does not seem to be any practical way to implement this check.
6835 elsif Ada_Version >= Ada_2005
6836 and then Tagged_Type_Expansion
6837 and then Is_Class_Wide_Type (R_Type)
6838 and then not Scope_Suppress (Accessibility_Check)
6840 (Is_Class_Wide_Type (Etype (Exp))
6841 or else Nkind_In (Exp, N_Type_Conversion,
6842 N_Unchecked_Type_Conversion)
6843 or else (Is_Entity_Name (Exp)
6844 and then Ekind (Entity (Exp)) in Formal_Kind)
6845 or else Scope_Depth (Enclosing_Dynamic_Scope (Etype (Exp))) >
6846 Scope_Depth (Enclosing_Dynamic_Scope (Scope_Id)))
6852 -- Ada 2005 (AI-251): In class-wide interface objects we displace
6853 -- "this" to reference the base of the object. This is required to
6854 -- get access to the TSD of the object.
6856 if Is_Class_Wide_Type (Etype (Exp))
6857 and then Is_Interface (Etype (Exp))
6858 and then Nkind (Exp) = N_Explicit_Dereference
6861 Make_Explicit_Dereference (Loc,
6863 Unchecked_Convert_To (RTE (RE_Tag_Ptr),
6864 Make_Function_Call (Loc,
6866 New_Reference_To (RTE (RE_Base_Address), Loc),
6867 Parameter_Associations => New_List (
6868 Unchecked_Convert_To (RTE (RE_Address),
6869 Duplicate_Subexpr (Prefix (Exp)))))));
6872 Make_Attribute_Reference (Loc,
6873 Prefix => Duplicate_Subexpr (Exp),
6874 Attribute_Name => Name_Tag);
6878 Make_Raise_Program_Error (Loc,
6881 Left_Opnd => Build_Get_Access_Level (Loc, Tag_Node),
6883 Make_Integer_Literal (Loc,
6884 Scope_Depth (Enclosing_Dynamic_Scope (Scope_Id)))),
6885 Reason => PE_Accessibility_Check_Failed));
6888 -- AI05-0073: If function has a controlling access result, check that
6889 -- the tag of the return value, if it is not null, matches designated
6890 -- type of return type.
6891 -- The return expression is referenced twice in the code below, so
6892 -- it must be made free of side effects. Given that different compilers
6893 -- may evaluate these parameters in different order, both occurrences
6896 elsif Ekind (R_Type) = E_Anonymous_Access_Type
6897 and then Has_Controlling_Result (Scope_Id)
6900 Make_Raise_Constraint_Error (Loc,
6905 Left_Opnd => Duplicate_Subexpr (Exp),
6906 Right_Opnd => Make_Null (Loc)),
6908 Right_Opnd => Make_Op_Ne (Loc,
6910 Make_Selected_Component (Loc,
6911 Prefix => Duplicate_Subexpr (Exp),
6912 Selector_Name => Make_Identifier (Loc, Name_uTag)),
6915 Make_Attribute_Reference (Loc,
6917 New_Occurrence_Of (Designated_Type (R_Type), Loc),
6918 Attribute_Name => Name_Tag))),
6920 Reason => CE_Tag_Check_Failed),
6921 Suppress => All_Checks);
6924 -- AI05-0234: RM 6.5(21/3). Check access discriminants to
6925 -- ensure that the function result does not outlive an
6926 -- object designated by one of it discriminants.
6928 if Present (Extra_Accessibility_Of_Result (Scope_Id))
6929 and then Has_Unconstrained_Access_Discriminants (R_Type)
6932 Discrim_Source : Node_Id;
6934 procedure Check_Against_Result_Level (Level : Node_Id);
6935 -- Check the given accessibility level against the level
6936 -- determined by the point of call. (AI05-0234).
6938 --------------------------------
6939 -- Check_Against_Result_Level --
6940 --------------------------------
6942 procedure Check_Against_Result_Level (Level : Node_Id) is
6945 Make_Raise_Program_Error (Loc,
6951 (Extra_Accessibility_Of_Result (Scope_Id), Loc)),
6952 Reason => PE_Accessibility_Check_Failed));
6953 end Check_Against_Result_Level;
6956 Discrim_Source := Exp;
6957 while Nkind (Discrim_Source) = N_Qualified_Expression loop
6958 Discrim_Source := Expression (Discrim_Source);
6961 if Nkind (Discrim_Source) = N_Identifier
6962 and then Is_Return_Object (Entity (Discrim_Source))
6964 Discrim_Source := Entity (Discrim_Source);
6966 if Is_Constrained (Etype (Discrim_Source)) then
6967 Discrim_Source := Etype (Discrim_Source);
6969 Discrim_Source := Expression (Parent (Discrim_Source));
6972 elsif Nkind (Discrim_Source) = N_Identifier
6973 and then Nkind_In (Original_Node (Discrim_Source),
6974 N_Aggregate, N_Extension_Aggregate)
6976 Discrim_Source := Original_Node (Discrim_Source);
6978 elsif Nkind (Discrim_Source) = N_Explicit_Dereference and then
6979 Nkind (Original_Node (Discrim_Source)) = N_Function_Call
6981 Discrim_Source := Original_Node (Discrim_Source);
6984 while Nkind_In (Discrim_Source, N_Qualified_Expression,
6986 N_Unchecked_Type_Conversion)
6988 Discrim_Source := Expression (Discrim_Source);
6991 case Nkind (Discrim_Source) is
6992 when N_Defining_Identifier =>
6994 pragma Assert (Is_Composite_Type (Discrim_Source)
6995 and then Has_Discriminants (Discrim_Source)
6996 and then Is_Constrained (Discrim_Source));
6999 Discrim : Entity_Id :=
7000 First_Discriminant (Base_Type (R_Type));
7001 Disc_Elmt : Elmt_Id :=
7002 First_Elmt (Discriminant_Constraint
7006 if Ekind (Etype (Discrim)) =
7007 E_Anonymous_Access_Type
7009 Check_Against_Result_Level
7010 (Dynamic_Accessibility_Level (Node (Disc_Elmt)));
7013 Next_Elmt (Disc_Elmt);
7014 Next_Discriminant (Discrim);
7015 exit when not Present (Discrim);
7019 when N_Aggregate | N_Extension_Aggregate =>
7021 -- Unimplemented: extension aggregate case where discrims
7022 -- come from ancestor part, not extension part.
7025 Discrim : Entity_Id :=
7026 First_Discriminant (Base_Type (R_Type));
7028 Disc_Exp : Node_Id := Empty;
7030 Positionals_Exhausted
7031 : Boolean := not Present (Expressions
7034 function Associated_Expr
7035 (Comp_Id : Entity_Id;
7036 Associations : List_Id) return Node_Id;
7038 -- Given a component and a component associations list,
7039 -- locate the expression for that component; returns
7040 -- Empty if no such expression is found.
7042 ---------------------
7043 -- Associated_Expr --
7044 ---------------------
7046 function Associated_Expr
7047 (Comp_Id : Entity_Id;
7048 Associations : List_Id) return Node_Id
7054 -- Simple linear search seems ok here
7056 Assoc := First (Associations);
7057 while Present (Assoc) loop
7058 Choice := First (Choices (Assoc));
7059 while Present (Choice) loop
7060 if (Nkind (Choice) = N_Identifier
7061 and then Chars (Choice) = Chars (Comp_Id))
7062 or else (Nkind (Choice) = N_Others_Choice)
7064 return Expression (Assoc);
7074 end Associated_Expr;
7076 -- Start of processing for Expand_Simple_Function_Return
7079 if not Positionals_Exhausted then
7080 Disc_Exp := First (Expressions (Discrim_Source));
7084 if Positionals_Exhausted then
7088 Component_Associations (Discrim_Source));
7091 if Ekind (Etype (Discrim)) =
7092 E_Anonymous_Access_Type
7094 Check_Against_Result_Level
7095 (Dynamic_Accessibility_Level (Disc_Exp));
7098 Next_Discriminant (Discrim);
7099 exit when not Present (Discrim);
7101 if not Positionals_Exhausted then
7103 Positionals_Exhausted := not Present (Disc_Exp);
7108 when N_Function_Call =>
7110 -- No check needed (check performed by callee)
7117 Level : constant Node_Id :=
7118 Make_Integer_Literal (Loc,
7119 Object_Access_Level (Discrim_Source));
7122 -- Unimplemented: check for name prefix that includes
7123 -- a dereference of an access value with a dynamic
7124 -- accessibility level (e.g., an access param or a
7125 -- saooaaat) and use dynamic level in that case. For
7127 -- return Access_Param.all(Some_Index).Some_Component;
7130 Set_Etype (Level, Standard_Natural);
7131 Check_Against_Result_Level (Level);
7138 -- If we are returning an object that may not be bit-aligned, then copy
7139 -- the value into a temporary first. This copy may need to expand to a
7140 -- loop of component operations.
7142 if Is_Possibly_Unaligned_Slice (Exp)
7143 or else Is_Possibly_Unaligned_Object (Exp)
7146 ExpR : constant Node_Id := Relocate_Node (Exp);
7147 Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', ExpR);
7150 Make_Object_Declaration (Loc,
7151 Defining_Identifier => Tnn,
7152 Constant_Present => True,
7153 Object_Definition => New_Occurrence_Of (R_Type, Loc),
7154 Expression => ExpR),
7155 Suppress => All_Checks);
7156 Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
7160 -- Generate call to postcondition checks if they are present
7162 if Ekind (Scope_Id) = E_Function
7163 and then Has_Postconditions (Scope_Id)
7165 -- We are going to reference the returned value twice in this case,
7166 -- once in the call to _Postconditions, and once in the actual return
7167 -- statement, but we can't have side effects happening twice, and in
7168 -- any case for efficiency we don't want to do the computation twice.
7170 -- If the returned expression is an entity name, we don't need to
7171 -- worry since it is efficient and safe to reference it twice, that's
7172 -- also true for literals other than string literals, and for the
7173 -- case of X.all where X is an entity name.
7175 if Is_Entity_Name (Exp)
7176 or else Nkind_In (Exp, N_Character_Literal,
7179 or else (Nkind (Exp) = N_Explicit_Dereference
7180 and then Is_Entity_Name (Prefix (Exp)))
7184 -- Otherwise we are going to need a temporary to capture the value
7188 ExpR : constant Node_Id := Relocate_Node (Exp);
7189 Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', ExpR);
7192 -- For a complex expression of an elementary type, capture
7193 -- value in the temporary and use it as the reference.
7195 if Is_Elementary_Type (R_Type) then
7197 Make_Object_Declaration (Loc,
7198 Defining_Identifier => Tnn,
7199 Constant_Present => True,
7200 Object_Definition => New_Occurrence_Of (R_Type, Loc),
7201 Expression => ExpR),
7202 Suppress => All_Checks);
7204 Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
7206 -- If we have something we can rename, generate a renaming of
7207 -- the object and replace the expression with a reference
7209 elsif Is_Object_Reference (Exp) then
7211 Make_Object_Renaming_Declaration (Loc,
7212 Defining_Identifier => Tnn,
7213 Subtype_Mark => New_Occurrence_Of (R_Type, Loc),
7215 Suppress => All_Checks);
7217 Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
7219 -- Otherwise we have something like a string literal or an
7220 -- aggregate. We could copy the value, but that would be
7221 -- inefficient. Instead we make a reference to the value and
7222 -- capture this reference with a renaming, the expression is
7223 -- then replaced by a dereference of this renaming.
7226 -- For now, copy the value, since the code below does not
7227 -- seem to work correctly ???
7230 Make_Object_Declaration (Loc,
7231 Defining_Identifier => Tnn,
7232 Constant_Present => True,
7233 Object_Definition => New_Occurrence_Of (R_Type, Loc),
7234 Expression => Relocate_Node (Exp)),
7235 Suppress => All_Checks);
7237 Rewrite (Exp, New_Occurrence_Of (Tnn, Loc));
7239 -- Insert_Action (Exp,
7240 -- Make_Object_Renaming_Declaration (Loc,
7241 -- Defining_Identifier => Tnn,
7242 -- Access_Definition =>
7243 -- Make_Access_Definition (Loc,
7244 -- All_Present => True,
7245 -- Subtype_Mark => New_Occurrence_Of (R_Type, Loc)),
7247 -- Make_Reference (Loc,
7248 -- Prefix => Relocate_Node (Exp))),
7249 -- Suppress => All_Checks);
7252 -- Make_Explicit_Dereference (Loc,
7253 -- Prefix => New_Occurrence_Of (Tnn, Loc)));
7258 -- Generate call to _postconditions
7261 Make_Procedure_Call_Statement (Loc,
7262 Name => Make_Identifier (Loc, Name_uPostconditions),
7263 Parameter_Associations => New_List (Duplicate_Subexpr (Exp))));
7266 -- Ada 2005 (AI-251): If this return statement corresponds with an
7267 -- simple return statement associated with an extended return statement
7268 -- and the type of the returned object is an interface then generate an
7269 -- implicit conversion to force displacement of the "this" pointer.
7271 if Ada_Version >= Ada_2005
7272 and then Comes_From_Extended_Return_Statement (N)
7273 and then Nkind (Expression (N)) = N_Identifier
7274 and then Is_Interface (Utyp)
7275 and then Utyp /= Underlying_Type (Exptyp)
7277 Rewrite (Exp, Convert_To (Utyp, Relocate_Node (Exp)));
7278 Analyze_And_Resolve (Exp);
7280 end Expand_Simple_Function_Return;
7282 --------------------------------
7283 -- Is_Build_In_Place_Function --
7284 --------------------------------
7286 function Is_Build_In_Place_Function (E : Entity_Id) return Boolean is
7288 -- This function is called from Expand_Subtype_From_Expr during
7289 -- semantic analysis, even when expansion is off. In those cases
7290 -- the build_in_place expansion will not take place.
7292 if not Expander_Active then
7296 -- For now we test whether E denotes a function or access-to-function
7297 -- type whose result subtype is inherently limited. Later this test may
7298 -- be revised to allow composite nonlimited types. Functions with a
7299 -- foreign convention or whose result type has a foreign convention
7302 if Ekind_In (E, E_Function, E_Generic_Function)
7303 or else (Ekind (E) = E_Subprogram_Type
7304 and then Etype (E) /= Standard_Void_Type)
7306 -- Note: If you have Convention (C) on an inherently limited type,
7307 -- you're on your own. That is, the C code will have to be carefully
7308 -- written to know about the Ada conventions.
7310 if Has_Foreign_Convention (E)
7311 or else Has_Foreign_Convention (Etype (E))
7315 -- In Ada 2005 all functions with an inherently limited return type
7316 -- must be handled using a build-in-place profile, including the case
7317 -- of a function with a limited interface result, where the function
7318 -- may return objects of nonlimited descendants.
7321 return Is_Immutably_Limited_Type (Etype (E))
7322 and then Ada_Version >= Ada_2005
7323 and then not Debug_Flag_Dot_L;
7329 end Is_Build_In_Place_Function;
7331 -------------------------------------
7332 -- Is_Build_In_Place_Function_Call --
7333 -------------------------------------
7335 function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean is
7336 Exp_Node : Node_Id := N;
7337 Function_Id : Entity_Id;
7340 -- Return False when the expander is inactive, since awareness of
7341 -- build-in-place treatment is only relevant during expansion. Note that
7342 -- Is_Build_In_Place_Function, which is called as part of this function,
7343 -- is also conditioned this way, but we need to check here as well to
7344 -- avoid blowing up on processing protected calls when expansion is
7345 -- disabled (such as with -gnatc) since those would trip over the raise
7346 -- of Program_Error below.
7348 if not Expander_Active then
7352 -- Step past qualification or unchecked conversion (the latter can occur
7353 -- in cases of calls to 'Input).
7355 if Nkind_In (Exp_Node, N_Qualified_Expression,
7356 N_Unchecked_Type_Conversion)
7358 Exp_Node := Expression (N);
7361 if Nkind (Exp_Node) /= N_Function_Call then
7365 -- In Alfa mode, build-in-place calls are not expanded, so that we
7366 -- may end up with a call that is neither resolved to an entity, nor
7367 -- an indirect call.
7372 elsif Is_Entity_Name (Name (Exp_Node)) then
7373 Function_Id := Entity (Name (Exp_Node));
7375 -- In the case of an explicitly dereferenced call, use the subprogram
7376 -- type generated for the dereference.
7378 elsif Nkind (Name (Exp_Node)) = N_Explicit_Dereference then
7379 Function_Id := Etype (Name (Exp_Node));
7382 raise Program_Error;
7385 return Is_Build_In_Place_Function (Function_Id);
7387 end Is_Build_In_Place_Function_Call;
7389 -----------------------
7390 -- Freeze_Subprogram --
7391 -----------------------
7393 procedure Freeze_Subprogram (N : Node_Id) is
7394 Loc : constant Source_Ptr := Sloc (N);
7396 procedure Register_Predefined_DT_Entry (Prim : Entity_Id);
7397 -- (Ada 2005): Register a predefined primitive in all the secondary
7398 -- dispatch tables of its primitive type.
7400 ----------------------------------
7401 -- Register_Predefined_DT_Entry --
7402 ----------------------------------
7404 procedure Register_Predefined_DT_Entry (Prim : Entity_Id) is
7405 Iface_DT_Ptr : Elmt_Id;
7406 Tagged_Typ : Entity_Id;
7407 Thunk_Id : Entity_Id;
7408 Thunk_Code : Node_Id;
7411 Tagged_Typ := Find_Dispatching_Type (Prim);
7413 if No (Access_Disp_Table (Tagged_Typ))
7414 or else not Has_Interfaces (Tagged_Typ)
7415 or else not RTE_Available (RE_Interface_Tag)
7416 or else Restriction_Active (No_Dispatching_Calls)
7421 -- Skip the first two access-to-dispatch-table pointers since they
7422 -- leads to the primary dispatch table (predefined DT and user
7423 -- defined DT). We are only concerned with the secondary dispatch
7424 -- table pointers. Note that the access-to- dispatch-table pointer
7425 -- corresponds to the first implemented interface retrieved below.
7428 Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Tagged_Typ))));
7430 while Present (Iface_DT_Ptr)
7431 and then Ekind (Node (Iface_DT_Ptr)) = E_Constant
7433 pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
7434 Expand_Interface_Thunk (Prim, Thunk_Id, Thunk_Code);
7436 if Present (Thunk_Code) then
7437 Insert_Actions_After (N, New_List (
7440 Build_Set_Predefined_Prim_Op_Address (Loc,
7442 New_Reference_To (Node (Next_Elmt (Iface_DT_Ptr)), Loc),
7443 Position => DT_Position (Prim),
7445 Unchecked_Convert_To (RTE (RE_Prim_Ptr),
7446 Make_Attribute_Reference (Loc,
7447 Prefix => New_Reference_To (Thunk_Id, Loc),
7448 Attribute_Name => Name_Unrestricted_Access))),
7450 Build_Set_Predefined_Prim_Op_Address (Loc,
7453 (Node (Next_Elmt (Next_Elmt (Next_Elmt (Iface_DT_Ptr)))),
7455 Position => DT_Position (Prim),
7457 Unchecked_Convert_To (RTE (RE_Prim_Ptr),
7458 Make_Attribute_Reference (Loc,
7459 Prefix => New_Reference_To (Prim, Loc),
7460 Attribute_Name => Name_Unrestricted_Access)))));
7463 -- Skip the tag of the predefined primitives dispatch table
7465 Next_Elmt (Iface_DT_Ptr);
7466 pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
7468 -- Skip tag of the no-thunks dispatch table
7470 Next_Elmt (Iface_DT_Ptr);
7471 pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
7473 -- Skip tag of predefined primitives no-thunks dispatch table
7475 Next_Elmt (Iface_DT_Ptr);
7476 pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
7478 Next_Elmt (Iface_DT_Ptr);
7480 end Register_Predefined_DT_Entry;
7484 Subp : constant Entity_Id := Entity (N);
7486 -- Start of processing for Freeze_Subprogram
7489 -- We suppress the initialization of the dispatch table entry when
7490 -- VM_Target because the dispatching mechanism is handled internally
7493 if Is_Dispatching_Operation (Subp)
7494 and then not Is_Abstract_Subprogram (Subp)
7495 and then Present (DTC_Entity (Subp))
7496 and then Present (Scope (DTC_Entity (Subp)))
7497 and then Tagged_Type_Expansion
7498 and then not Restriction_Active (No_Dispatching_Calls)
7499 and then RTE_Available (RE_Tag)
7502 Typ : constant Entity_Id := Scope (DTC_Entity (Subp));
7505 -- Handle private overridden primitives
7507 if not Is_CPP_Class (Typ) then
7508 Check_Overriding_Operation (Subp);
7511 -- We assume that imported CPP primitives correspond with objects
7512 -- whose constructor is in the CPP side; therefore we don't need
7513 -- to generate code to register them in the dispatch table.
7515 if Is_CPP_Class (Typ) then
7518 -- Handle CPP primitives found in derivations of CPP_Class types.
7519 -- These primitives must have been inherited from some parent, and
7520 -- there is no need to register them in the dispatch table because
7521 -- Build_Inherit_Prims takes care of the initialization of these
7524 elsif Is_Imported (Subp)
7525 and then (Convention (Subp) = Convention_CPP
7526 or else Convention (Subp) = Convention_C)
7530 -- Generate code to register the primitive in non statically
7531 -- allocated dispatch tables
7533 elsif not Building_Static_DT (Scope (DTC_Entity (Subp))) then
7535 -- When a primitive is frozen, enter its name in its dispatch
7538 if not Is_Interface (Typ)
7539 or else Present (Interface_Alias (Subp))
7541 if Is_Predefined_Dispatching_Operation (Subp) then
7542 Register_Predefined_DT_Entry (Subp);
7545 Insert_Actions_After (N,
7546 Register_Primitive (Loc, Prim => Subp));
7552 -- Mark functions that return by reference. Note that it cannot be part
7553 -- of the normal semantic analysis of the spec since the underlying
7554 -- returned type may not be known yet (for private types).
7557 Typ : constant Entity_Id := Etype (Subp);
7558 Utyp : constant Entity_Id := Underlying_Type (Typ);
7560 if Is_Immutably_Limited_Type (Typ) then
7561 Set_Returns_By_Ref (Subp);
7562 elsif Present (Utyp) and then CW_Or_Has_Controlled_Part (Utyp) then
7563 Set_Returns_By_Ref (Subp);
7566 end Freeze_Subprogram;
7568 -----------------------
7569 -- Is_Null_Procedure --
7570 -----------------------
7572 function Is_Null_Procedure (Subp : Entity_Id) return Boolean is
7573 Decl : constant Node_Id := Unit_Declaration_Node (Subp);
7576 if Ekind (Subp) /= E_Procedure then
7579 -- Check if this is a declared null procedure
7581 elsif Nkind (Decl) = N_Subprogram_Declaration then
7582 if not Null_Present (Specification (Decl)) then
7585 elsif No (Body_To_Inline (Decl)) then
7588 -- Check if the body contains only a null statement, followed by
7589 -- the return statement added during expansion.
7593 Orig_Bod : constant Node_Id := Body_To_Inline (Decl);
7599 if Nkind (Orig_Bod) /= N_Subprogram_Body then
7602 -- We must skip SCIL nodes because they are currently
7603 -- implemented as special N_Null_Statement nodes.
7607 (Statements (Handled_Statement_Sequence (Orig_Bod)));
7608 Stat2 := Next_Non_SCIL_Node (Stat);
7611 Is_Empty_List (Declarations (Orig_Bod))
7612 and then Nkind (Stat) = N_Null_Statement
7616 (Nkind (Stat2) = N_Simple_Return_Statement
7617 and then No (Next (Stat2))));
7625 end Is_Null_Procedure;
7627 -------------------------------------------
7628 -- Make_Build_In_Place_Call_In_Allocator --
7629 -------------------------------------------
7631 procedure Make_Build_In_Place_Call_In_Allocator
7632 (Allocator : Node_Id;
7633 Function_Call : Node_Id)
7635 Acc_Type : constant Entity_Id := Etype (Allocator);
7637 Func_Call : Node_Id := Function_Call;
7638 Function_Id : Entity_Id;
7639 Result_Subt : Entity_Id;
7640 New_Allocator : Node_Id;
7641 Return_Obj_Access : Entity_Id;
7644 -- Step past qualification or unchecked conversion (the latter can occur
7645 -- in cases of calls to 'Input).
7647 if Nkind_In (Func_Call,
7648 N_Qualified_Expression,
7649 N_Unchecked_Type_Conversion)
7651 Func_Call := Expression (Func_Call);
7654 -- If the call has already been processed to add build-in-place actuals
7655 -- then return. This should not normally occur in an allocator context,
7656 -- but we add the protection as a defensive measure.
7658 if Is_Expanded_Build_In_Place_Call (Func_Call) then
7662 -- Mark the call as processed as a build-in-place call
7664 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
7666 Loc := Sloc (Function_Call);
7668 if Is_Entity_Name (Name (Func_Call)) then
7669 Function_Id := Entity (Name (Func_Call));
7671 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
7672 Function_Id := Etype (Name (Func_Call));
7675 raise Program_Error;
7678 Result_Subt := Available_View (Etype (Function_Id));
7680 -- Check whether return type includes tasks. This may not have been done
7681 -- previously, if the type was a limited view.
7683 if Has_Task (Result_Subt) then
7684 Build_Activation_Chain_Entity (Allocator);
7687 -- When the result subtype is constrained, the return object must be
7688 -- allocated on the caller side, and access to it is passed to the
7691 -- Here and in related routines, we must examine the full view of the
7692 -- type, because the view at the point of call may differ from that
7693 -- that in the function body, and the expansion mechanism depends on
7694 -- the characteristics of the full view.
7696 if Is_Constrained (Underlying_Type (Result_Subt)) then
7698 -- Replace the initialized allocator of form "new T'(Func (...))"
7699 -- with an uninitialized allocator of form "new T", where T is the
7700 -- result subtype of the called function. The call to the function
7701 -- is handled separately further below.
7704 Make_Allocator (Loc,
7705 Expression => New_Reference_To (Result_Subt, Loc));
7706 Set_No_Initialization (New_Allocator);
7708 -- Copy attributes to new allocator. Note that the new allocator
7709 -- logically comes from source if the original one did, so copy the
7710 -- relevant flag. This ensures proper treatment of the restriction
7711 -- No_Implicit_Heap_Allocations in this case.
7713 Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
7714 Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
7715 Set_Comes_From_Source (New_Allocator, Comes_From_Source (Allocator));
7717 Rewrite (Allocator, New_Allocator);
7719 -- Create a new access object and initialize it to the result of the
7720 -- new uninitialized allocator. Note: we do not use Allocator as the
7721 -- Related_Node of Return_Obj_Access in call to Make_Temporary below
7722 -- as this would create a sort of infinite "recursion".
7724 Return_Obj_Access := Make_Temporary (Loc, 'R');
7725 Set_Etype (Return_Obj_Access, Acc_Type);
7727 Insert_Action (Allocator,
7728 Make_Object_Declaration (Loc,
7729 Defining_Identifier => Return_Obj_Access,
7730 Object_Definition => New_Reference_To (Acc_Type, Loc),
7731 Expression => Relocate_Node (Allocator)));
7733 -- When the function has a controlling result, an allocation-form
7734 -- parameter must be passed indicating that the caller is allocating
7735 -- the result object. This is needed because such a function can be
7736 -- called as a dispatching operation and must be treated similarly
7737 -- to functions with unconstrained result subtypes.
7739 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7740 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
7742 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7743 (Func_Call, Function_Id, Acc_Type);
7745 Add_Task_Actuals_To_Build_In_Place_Call
7746 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
7748 -- Add an implicit actual to the function call that provides access
7749 -- to the allocated object. An unchecked conversion to the (specific)
7750 -- result subtype of the function is inserted to handle cases where
7751 -- the access type of the allocator has a class-wide designated type.
7753 Add_Access_Actual_To_Build_In_Place_Call
7756 Make_Unchecked_Type_Conversion (Loc,
7757 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
7759 Make_Explicit_Dereference (Loc,
7760 Prefix => New_Reference_To (Return_Obj_Access, Loc))));
7762 -- When the result subtype is unconstrained, the function itself must
7763 -- perform the allocation of the return object, so we pass parameters
7764 -- indicating that. We don't yet handle the case where the allocation
7765 -- must be done in a user-defined storage pool, which will require
7766 -- passing another actual or two to provide allocation/deallocation
7770 -- Case of a user-defined storage pool. Pass an allocation parameter
7771 -- indicating that the function should allocate its result in the
7772 -- pool, and pass the pool. Use 'Unrestricted_Access because the
7773 -- pool may not be aliased.
7775 if VM_Target = No_VM
7776 and then Present (Associated_Storage_Pool (Acc_Type))
7778 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7779 (Func_Call, Function_Id, Alloc_Form => User_Storage_Pool,
7781 Make_Attribute_Reference (Loc,
7784 (Associated_Storage_Pool (Acc_Type), Loc),
7785 Attribute_Name => Name_Unrestricted_Access));
7787 -- No user-defined pool; pass an allocation parameter indicating that
7788 -- the function should allocate its result on the heap.
7791 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7792 (Func_Call, Function_Id, Alloc_Form => Global_Heap);
7795 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7796 (Func_Call, Function_Id, Acc_Type);
7798 Add_Task_Actuals_To_Build_In_Place_Call
7799 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
7801 -- The caller does not provide the return object in this case, so we
7802 -- have to pass null for the object access actual.
7804 Add_Access_Actual_To_Build_In_Place_Call
7805 (Func_Call, Function_Id, Return_Object => Empty);
7808 -- If the build-in-place function call returns a controlled object,
7809 -- the finalization master will require a reference to routine
7810 -- Finalize_Address of the designated type. Setting this attribute
7811 -- is done in the same manner to expansion of allocators.
7813 if Needs_Finalization (Result_Subt) then
7815 -- Controlled types with supressed finalization do not need to
7816 -- associate the address of their Finalize_Address primitives with
7817 -- a master since they do not need a master to begin with.
7819 if Is_Library_Level_Entity (Acc_Type)
7820 and then Finalize_Storage_Only (Result_Subt)
7824 -- Do not generate the call to Set_Finalize_Address in Alfa mode
7825 -- because it is not necessary and results in unwanted expansion.
7826 -- This expansion is also not carried out in CodePeer mode because
7827 -- Finalize_Address is never built.
7830 and then not CodePeer_Mode
7832 Insert_Action (Allocator,
7833 Make_Set_Finalize_Address_Call (Loc,
7834 Typ => Etype (Function_Id),
7835 Ptr_Typ => Acc_Type));
7839 -- Finally, replace the allocator node with a reference to the result
7840 -- of the function call itself (which will effectively be an access
7841 -- to the object created by the allocator).
7843 Rewrite (Allocator, Make_Reference (Loc, Relocate_Node (Function_Call)));
7845 -- Ada 2005 (AI-251): If the type of the allocator is an interface then
7846 -- generate an implicit conversion to force displacement of the "this"
7849 if Is_Interface (Designated_Type (Acc_Type)) then
7850 Rewrite (Allocator, Convert_To (Acc_Type, Relocate_Node (Allocator)));
7853 Analyze_And_Resolve (Allocator, Acc_Type);
7854 end Make_Build_In_Place_Call_In_Allocator;
7856 ---------------------------------------------------
7857 -- Make_Build_In_Place_Call_In_Anonymous_Context --
7858 ---------------------------------------------------
7860 procedure Make_Build_In_Place_Call_In_Anonymous_Context
7861 (Function_Call : Node_Id)
7864 Func_Call : Node_Id := Function_Call;
7865 Function_Id : Entity_Id;
7866 Result_Subt : Entity_Id;
7867 Return_Obj_Id : Entity_Id;
7868 Return_Obj_Decl : Entity_Id;
7871 -- Step past qualification or unchecked conversion (the latter can occur
7872 -- in cases of calls to 'Input).
7874 if Nkind_In (Func_Call, N_Qualified_Expression,
7875 N_Unchecked_Type_Conversion)
7877 Func_Call := Expression (Func_Call);
7880 -- If the call has already been processed to add build-in-place actuals
7881 -- then return. One place this can occur is for calls to build-in-place
7882 -- functions that occur within a call to a protected operation, where
7883 -- due to rewriting and expansion of the protected call there can be
7884 -- more than one call to Expand_Actuals for the same set of actuals.
7886 if Is_Expanded_Build_In_Place_Call (Func_Call) then
7890 -- Mark the call as processed as a build-in-place call
7892 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
7894 Loc := Sloc (Function_Call);
7896 if Is_Entity_Name (Name (Func_Call)) then
7897 Function_Id := Entity (Name (Func_Call));
7899 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
7900 Function_Id := Etype (Name (Func_Call));
7903 raise Program_Error;
7906 Result_Subt := Etype (Function_Id);
7908 -- If the build-in-place function returns a controlled object, then the
7909 -- object needs to be finalized immediately after the context. Since
7910 -- this case produces a transient scope, the servicing finalizer needs
7911 -- to name the returned object. Create a temporary which is initialized
7912 -- with the function call:
7914 -- Temp_Id : Func_Type := BIP_Func_Call;
7916 -- The initialization expression of the temporary will be rewritten by
7917 -- the expander using the appropriate mechanism in Make_Build_In_Place_
7918 -- Call_In_Object_Declaration.
7920 if Needs_Finalization (Result_Subt) then
7922 Temp_Id : constant Entity_Id := Make_Temporary (Loc, 'R');
7923 Temp_Decl : Node_Id;
7926 -- Reset the guard on the function call since the following does
7927 -- not perform actual call expansion.
7929 Set_Is_Expanded_Build_In_Place_Call (Func_Call, False);
7932 Make_Object_Declaration (Loc,
7933 Defining_Identifier => Temp_Id,
7934 Object_Definition =>
7935 New_Reference_To (Result_Subt, Loc),
7937 New_Copy_Tree (Function_Call));
7939 Insert_Action (Function_Call, Temp_Decl);
7941 Rewrite (Function_Call, New_Reference_To (Temp_Id, Loc));
7942 Analyze (Function_Call);
7945 -- When the result subtype is constrained, an object of the subtype is
7946 -- declared and an access value designating it is passed as an actual.
7948 elsif Is_Constrained (Underlying_Type (Result_Subt)) then
7950 -- Create a temporary object to hold the function result
7952 Return_Obj_Id := Make_Temporary (Loc, 'R');
7953 Set_Etype (Return_Obj_Id, Result_Subt);
7956 Make_Object_Declaration (Loc,
7957 Defining_Identifier => Return_Obj_Id,
7958 Aliased_Present => True,
7959 Object_Definition => New_Reference_To (Result_Subt, Loc));
7961 Set_No_Initialization (Return_Obj_Decl);
7963 Insert_Action (Func_Call, Return_Obj_Decl);
7965 -- When the function has a controlling result, an allocation-form
7966 -- parameter must be passed indicating that the caller is allocating
7967 -- the result object. This is needed because such a function can be
7968 -- called as a dispatching operation and must be treated similarly
7969 -- to functions with unconstrained result subtypes.
7971 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7972 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
7974 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7975 (Func_Call, Function_Id);
7977 Add_Task_Actuals_To_Build_In_Place_Call
7978 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
7980 -- Add an implicit actual to the function call that provides access
7981 -- to the caller's return object.
7983 Add_Access_Actual_To_Build_In_Place_Call
7984 (Func_Call, Function_Id, New_Reference_To (Return_Obj_Id, Loc));
7986 -- When the result subtype is unconstrained, the function must allocate
7987 -- the return object in the secondary stack, so appropriate implicit
7988 -- parameters are added to the call to indicate that. A transient
7989 -- scope is established to ensure eventual cleanup of the result.
7992 -- Pass an allocation parameter indicating that the function should
7993 -- allocate its result on the secondary stack.
7995 Add_Unconstrained_Actuals_To_Build_In_Place_Call
7996 (Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
7998 Add_Finalization_Master_Actual_To_Build_In_Place_Call
7999 (Func_Call, Function_Id);
8001 Add_Task_Actuals_To_Build_In_Place_Call
8002 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
8004 -- Pass a null value to the function since no return object is
8005 -- available on the caller side.
8007 Add_Access_Actual_To_Build_In_Place_Call
8008 (Func_Call, Function_Id, Empty);
8010 end Make_Build_In_Place_Call_In_Anonymous_Context;
8012 --------------------------------------------
8013 -- Make_Build_In_Place_Call_In_Assignment --
8014 --------------------------------------------
8016 procedure Make_Build_In_Place_Call_In_Assignment
8018 Function_Call : Node_Id)
8020 Lhs : constant Node_Id := Name (Assign);
8021 Func_Call : Node_Id := Function_Call;
8022 Func_Id : Entity_Id;
8026 Ptr_Typ : Entity_Id;
8027 Ptr_Typ_Decl : Node_Id;
8029 Result_Subt : Entity_Id;
8033 -- Step past qualification or unchecked conversion (the latter can occur
8034 -- in cases of calls to 'Input).
8036 if Nkind_In (Func_Call, N_Qualified_Expression,
8037 N_Unchecked_Type_Conversion)
8039 Func_Call := Expression (Func_Call);
8042 -- If the call has already been processed to add build-in-place actuals
8043 -- then return. This should not normally occur in an assignment context,
8044 -- but we add the protection as a defensive measure.
8046 if Is_Expanded_Build_In_Place_Call (Func_Call) then
8050 -- Mark the call as processed as a build-in-place call
8052 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
8054 Loc := Sloc (Function_Call);
8056 if Is_Entity_Name (Name (Func_Call)) then
8057 Func_Id := Entity (Name (Func_Call));
8059 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
8060 Func_Id := Etype (Name (Func_Call));
8063 raise Program_Error;
8066 Result_Subt := Etype (Func_Id);
8068 -- When the result subtype is unconstrained, an additional actual must
8069 -- be passed to indicate that the caller is providing the return object.
8070 -- This parameter must also be passed when the called function has a
8071 -- controlling result, because dispatching calls to the function needs
8072 -- to be treated effectively the same as calls to class-wide functions.
8074 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8075 (Func_Call, Func_Id, Alloc_Form => Caller_Allocation);
8077 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8078 (Func_Call, Func_Id);
8080 Add_Task_Actuals_To_Build_In_Place_Call
8081 (Func_Call, Func_Id, Make_Identifier (Loc, Name_uMaster));
8083 -- Add an implicit actual to the function call that provides access to
8084 -- the caller's return object.
8086 Add_Access_Actual_To_Build_In_Place_Call
8089 Make_Unchecked_Type_Conversion (Loc,
8090 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
8091 Expression => Relocate_Node (Lhs)));
8093 -- Create an access type designating the function's result subtype
8095 Ptr_Typ := Make_Temporary (Loc, 'A');
8098 Make_Full_Type_Declaration (Loc,
8099 Defining_Identifier => Ptr_Typ,
8101 Make_Access_To_Object_Definition (Loc,
8102 All_Present => True,
8103 Subtype_Indication =>
8104 New_Reference_To (Result_Subt, Loc)));
8105 Insert_After_And_Analyze (Assign, Ptr_Typ_Decl);
8107 -- Finally, create an access object initialized to a reference to the
8108 -- function call. We know this access value is non-null, so mark the
8109 -- entity accordingly to suppress junk access checks.
8111 New_Expr := Make_Reference (Loc, Relocate_Node (Func_Call));
8113 Obj_Id := Make_Temporary (Loc, 'R', New_Expr);
8114 Set_Etype (Obj_Id, Ptr_Typ);
8115 Set_Is_Known_Non_Null (Obj_Id);
8118 Make_Object_Declaration (Loc,
8119 Defining_Identifier => Obj_Id,
8120 Object_Definition => New_Reference_To (Ptr_Typ, Loc),
8121 Expression => New_Expr);
8122 Insert_After_And_Analyze (Ptr_Typ_Decl, Obj_Decl);
8124 Rewrite (Assign, Make_Null_Statement (Loc));
8126 -- Retrieve the target of the assignment
8128 if Nkind (Lhs) = N_Selected_Component then
8129 Target := Selector_Name (Lhs);
8130 elsif Nkind (Lhs) = N_Type_Conversion then
8131 Target := Expression (Lhs);
8136 -- If we are assigning to a return object or this is an expression of
8137 -- an extension aggregate, the target should either be an identifier
8138 -- or a simple expression. All other cases imply a different scenario.
8140 if Nkind (Target) in N_Has_Entity then
8141 Target := Entity (Target);
8145 end Make_Build_In_Place_Call_In_Assignment;
8147 ----------------------------------------------------
8148 -- Make_Build_In_Place_Call_In_Object_Declaration --
8149 ----------------------------------------------------
8151 procedure Make_Build_In_Place_Call_In_Object_Declaration
8152 (Object_Decl : Node_Id;
8153 Function_Call : Node_Id)
8156 Obj_Def_Id : constant Entity_Id :=
8157 Defining_Identifier (Object_Decl);
8158 Enclosing_Func : constant Entity_Id :=
8159 Enclosing_Subprogram (Obj_Def_Id);
8160 Call_Deref : Node_Id;
8161 Caller_Object : Node_Id;
8163 Fmaster_Actual : Node_Id := Empty;
8164 Func_Call : Node_Id := Function_Call;
8165 Function_Id : Entity_Id;
8166 Pool_Actual : Node_Id;
8167 Ptr_Typ_Decl : Node_Id;
8168 Pass_Caller_Acc : Boolean := False;
8170 Ref_Type : Entity_Id;
8171 Result_Subt : Entity_Id;
8174 -- Step past qualification or unchecked conversion (the latter can occur
8175 -- in cases of calls to 'Input).
8177 if Nkind_In (Func_Call, N_Qualified_Expression,
8178 N_Unchecked_Type_Conversion)
8180 Func_Call := Expression (Func_Call);
8183 -- If the call has already been processed to add build-in-place actuals
8184 -- then return. This should not normally occur in an object declaration,
8185 -- but we add the protection as a defensive measure.
8187 if Is_Expanded_Build_In_Place_Call (Func_Call) then
8191 -- Mark the call as processed as a build-in-place call
8193 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
8195 Loc := Sloc (Function_Call);
8197 if Is_Entity_Name (Name (Func_Call)) then
8198 Function_Id := Entity (Name (Func_Call));
8200 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
8201 Function_Id := Etype (Name (Func_Call));
8204 raise Program_Error;
8207 Result_Subt := Etype (Function_Id);
8209 -- If the the object is a return object of an enclosing build-in-place
8210 -- function, then the implicit build-in-place parameters of the
8211 -- enclosing function are simply passed along to the called function.
8212 -- (Unfortunately, this won't cover the case of extension aggregates
8213 -- where the ancestor part is a build-in-place unconstrained function
8214 -- call that should be passed along the caller's parameters. Currently
8215 -- those get mishandled by reassigning the result of the call to the
8216 -- aggregate return object, when the call result should really be
8217 -- directly built in place in the aggregate and not in a temporary. ???)
8219 if Is_Return_Object (Defining_Identifier (Object_Decl)) then
8220 Pass_Caller_Acc := True;
8222 -- When the enclosing function has a BIP_Alloc_Form formal then we
8223 -- pass it along to the callee (such as when the enclosing function
8224 -- has an unconstrained or tagged result type).
8226 if Needs_BIP_Alloc_Form (Enclosing_Func) then
8227 if VM_Target = No_VM and then
8228 RTE_Available (RE_Root_Storage_Pool_Ptr)
8231 New_Reference_To (Build_In_Place_Formal
8232 (Enclosing_Func, BIP_Storage_Pool), Loc);
8234 -- The build-in-place pool formal is not built on .NET/JVM
8237 Pool_Actual := Empty;
8240 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8245 (Build_In_Place_Formal (Enclosing_Func, BIP_Alloc_Form),
8247 Pool_Actual => Pool_Actual);
8249 -- Otherwise, if enclosing function has a constrained result subtype,
8250 -- then caller allocation will be used.
8253 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8254 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
8257 if Needs_BIP_Finalization_Master (Enclosing_Func) then
8260 (Build_In_Place_Formal
8261 (Enclosing_Func, BIP_Finalization_Master), Loc);
8264 -- Retrieve the BIPacc formal from the enclosing function and convert
8265 -- it to the access type of the callee's BIP_Object_Access formal.
8268 Make_Unchecked_Type_Conversion (Loc,
8272 (Build_In_Place_Formal (Function_Id, BIP_Object_Access)),
8276 (Build_In_Place_Formal (Enclosing_Func, BIP_Object_Access),
8279 -- In the constrained case, add an implicit actual to the function call
8280 -- that provides access to the declared object. An unchecked conversion
8281 -- to the (specific) result type of the function is inserted to handle
8282 -- the case where the object is declared with a class-wide type.
8284 elsif Is_Constrained (Underlying_Type (Result_Subt)) then
8286 Make_Unchecked_Type_Conversion (Loc,
8287 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
8288 Expression => New_Reference_To (Obj_Def_Id, Loc));
8290 -- When the function has a controlling result, an allocation-form
8291 -- parameter must be passed indicating that the caller is allocating
8292 -- the result object. This is needed because such a function can be
8293 -- called as a dispatching operation and must be treated similarly
8294 -- to functions with unconstrained result subtypes.
8296 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8297 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
8299 -- In other unconstrained cases, pass an indication to do the allocation
8300 -- on the secondary stack and set Caller_Object to Empty so that a null
8301 -- value will be passed for the caller's object address. A transient
8302 -- scope is established to ensure eventual cleanup of the result.
8305 Add_Unconstrained_Actuals_To_Build_In_Place_Call
8306 (Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
8307 Caller_Object := Empty;
8309 Establish_Transient_Scope (Object_Decl, Sec_Stack => True);
8312 -- Pass along any finalization master actual, which is needed in the
8313 -- case where the called function initializes a return object of an
8314 -- enclosing build-in-place function.
8316 Add_Finalization_Master_Actual_To_Build_In_Place_Call
8317 (Func_Call => Func_Call,
8318 Func_Id => Function_Id,
8319 Master_Exp => Fmaster_Actual);
8321 if Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement
8322 and then Has_Task (Result_Subt)
8324 -- Here we're passing along the master that was passed in to this
8327 Add_Task_Actuals_To_Build_In_Place_Call
8328 (Func_Call, Function_Id,
8330 New_Reference_To (Build_In_Place_Formal
8331 (Enclosing_Func, BIP_Task_Master), Loc));
8334 Add_Task_Actuals_To_Build_In_Place_Call
8335 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
8338 Add_Access_Actual_To_Build_In_Place_Call
8339 (Func_Call, Function_Id, Caller_Object, Is_Access => Pass_Caller_Acc);
8341 -- Create an access type designating the function's result subtype. We
8342 -- use the type of the original expression because it may be a call to
8343 -- an inherited operation, which the expansion has replaced with the
8344 -- parent operation that yields the parent type.
8346 Ref_Type := Make_Temporary (Loc, 'A');
8349 Make_Full_Type_Declaration (Loc,
8350 Defining_Identifier => Ref_Type,
8352 Make_Access_To_Object_Definition (Loc,
8353 All_Present => True,
8354 Subtype_Indication =>
8355 New_Reference_To (Etype (Function_Call), Loc)));
8357 -- The access type and its accompanying object must be inserted after
8358 -- the object declaration in the constrained case, so that the function
8359 -- call can be passed access to the object. In the unconstrained case,
8360 -- or if the object declaration is for a return object, the access type
8361 -- and object must be inserted before the object, since the object
8362 -- declaration is rewritten to be a renaming of a dereference of the
8365 if Is_Constrained (Underlying_Type (Result_Subt))
8366 and then not Is_Return_Object (Defining_Identifier (Object_Decl))
8368 Insert_After_And_Analyze (Object_Decl, Ptr_Typ_Decl);
8370 Insert_Action (Object_Decl, Ptr_Typ_Decl);
8373 -- Finally, create an access object initialized to a reference to the
8374 -- function call. We know this access value cannot be null, so mark the
8375 -- entity accordingly to suppress the access check.
8377 New_Expr := Make_Reference (Loc, Relocate_Node (Func_Call));
8379 Def_Id := Make_Temporary (Loc, 'R', New_Expr);
8380 Set_Etype (Def_Id, Ref_Type);
8381 Set_Is_Known_Non_Null (Def_Id);
8383 Insert_After_And_Analyze (Ptr_Typ_Decl,
8384 Make_Object_Declaration (Loc,
8385 Defining_Identifier => Def_Id,
8386 Object_Definition => New_Reference_To (Ref_Type, Loc),
8387 Expression => New_Expr));
8389 -- If the result subtype of the called function is constrained and
8390 -- is not itself the return expression of an enclosing BIP function,
8391 -- then mark the object as having no initialization.
8393 if Is_Constrained (Underlying_Type (Result_Subt))
8394 and then not Is_Return_Object (Defining_Identifier (Object_Decl))
8396 Set_Expression (Object_Decl, Empty);
8397 Set_No_Initialization (Object_Decl);
8399 -- In case of an unconstrained result subtype, or if the call is the
8400 -- return expression of an enclosing BIP function, rewrite the object
8401 -- declaration as an object renaming where the renamed object is a
8402 -- dereference of <function_Call>'reference:
8404 -- Obj : Subt renames <function_call>'Ref.all;
8408 Make_Explicit_Dereference (Loc,
8409 Prefix => New_Reference_To (Def_Id, Loc));
8411 Loc := Sloc (Object_Decl);
8412 Rewrite (Object_Decl,
8413 Make_Object_Renaming_Declaration (Loc,
8414 Defining_Identifier => Make_Temporary (Loc, 'D'),
8415 Access_Definition => Empty,
8416 Subtype_Mark => New_Occurrence_Of (Result_Subt, Loc),
8417 Name => Call_Deref));
8419 Set_Renamed_Object (Defining_Identifier (Object_Decl), Call_Deref);
8421 Analyze (Object_Decl);
8423 -- Replace the internal identifier of the renaming declaration's
8424 -- entity with identifier of the original object entity. We also have
8425 -- to exchange the entities containing their defining identifiers to
8426 -- ensure the correct replacement of the object declaration by the
8427 -- object renaming declaration to avoid homograph conflicts (since
8428 -- the object declaration's defining identifier was already entered
8429 -- in current scope). The Next_Entity links of the two entities also
8430 -- have to be swapped since the entities are part of the return
8431 -- scope's entity list and the list structure would otherwise be
8432 -- corrupted. Finally, the homonym chain must be preserved as well.
8435 Renaming_Def_Id : constant Entity_Id :=
8436 Defining_Identifier (Object_Decl);
8437 Next_Entity_Temp : constant Entity_Id :=
8438 Next_Entity (Renaming_Def_Id);
8440 Set_Chars (Renaming_Def_Id, Chars (Obj_Def_Id));
8442 -- Swap next entity links in preparation for exchanging entities
8444 Set_Next_Entity (Renaming_Def_Id, Next_Entity (Obj_Def_Id));
8445 Set_Next_Entity (Obj_Def_Id, Next_Entity_Temp);
8446 Set_Homonym (Renaming_Def_Id, Homonym (Obj_Def_Id));
8448 Exchange_Entities (Renaming_Def_Id, Obj_Def_Id);
8450 -- Preserve source indication of original declaration, so that
8451 -- xref information is properly generated for the right entity.
8453 Preserve_Comes_From_Source
8454 (Object_Decl, Original_Node (Object_Decl));
8456 Preserve_Comes_From_Source
8457 (Obj_Def_Id, Original_Node (Object_Decl));
8459 Set_Comes_From_Source (Renaming_Def_Id, False);
8463 -- If the object entity has a class-wide Etype, then we need to change
8464 -- it to the result subtype of the function call, because otherwise the
8465 -- object will be class-wide without an explicit initialization and
8466 -- won't be allocated properly by the back end. It seems unclean to make
8467 -- such a revision to the type at this point, and we should try to
8468 -- improve this treatment when build-in-place functions with class-wide
8469 -- results are implemented. ???
8471 if Is_Class_Wide_Type (Etype (Defining_Identifier (Object_Decl))) then
8472 Set_Etype (Defining_Identifier (Object_Decl), Result_Subt);
8474 end Make_Build_In_Place_Call_In_Object_Declaration;
8476 -----------------------------------
8477 -- Needs_BIP_Finalization_Master --
8478 -----------------------------------
8480 function Needs_BIP_Finalization_Master
8481 (Func_Id : Entity_Id) return Boolean
8483 pragma Assert (Is_Build_In_Place_Function (Func_Id));
8484 Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
8487 not Restriction_Active (No_Finalization)
8488 and then Needs_Finalization (Func_Typ);
8489 end Needs_BIP_Finalization_Master;
8491 --------------------------
8492 -- Needs_BIP_Alloc_Form --
8493 --------------------------
8495 function Needs_BIP_Alloc_Form (Func_Id : Entity_Id) return Boolean is
8496 pragma Assert (Is_Build_In_Place_Function (Func_Id));
8497 Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
8499 return not Is_Constrained (Func_Typ) or else Is_Tagged_Type (Func_Typ);
8500 end Needs_BIP_Alloc_Form;
8502 --------------------------------------
8503 -- Needs_Result_Accessibility_Level --
8504 --------------------------------------
8506 function Needs_Result_Accessibility_Level
8507 (Func_Id : Entity_Id) return Boolean
8509 Func_Typ : constant Entity_Id := Underlying_Type (Etype (Func_Id));
8511 function Has_Unconstrained_Access_Discriminant_Component
8512 (Comp_Typ : Entity_Id) return Boolean;
8513 -- Returns True if any component of the type has an unconstrained access
8516 -----------------------------------------------------
8517 -- Has_Unconstrained_Access_Discriminant_Component --
8518 -----------------------------------------------------
8520 function Has_Unconstrained_Access_Discriminant_Component
8521 (Comp_Typ : Entity_Id) return Boolean
8524 if not Is_Limited_Type (Comp_Typ) then
8527 -- Only limited types can have access discriminants with
8530 elsif Has_Unconstrained_Access_Discriminants (Comp_Typ) then
8533 elsif Is_Array_Type (Comp_Typ) then
8534 return Has_Unconstrained_Access_Discriminant_Component
8535 (Underlying_Type (Component_Type (Comp_Typ)));
8537 elsif Is_Record_Type (Comp_Typ) then
8542 Comp := First_Component (Comp_Typ);
8543 while Present (Comp) loop
8544 if Has_Unconstrained_Access_Discriminant_Component
8545 (Underlying_Type (Etype (Comp)))
8550 Next_Component (Comp);
8556 end Has_Unconstrained_Access_Discriminant_Component;
8558 Feature_Disabled : constant Boolean := True;
8561 -- Start of processing for Needs_Result_Accessibility_Level
8564 -- False if completion unavailable (how does this happen???)
8566 if not Present (Func_Typ) then
8569 elsif Feature_Disabled then
8572 -- False if not a function, also handle enum-lit renames case
8574 elsif Func_Typ = Standard_Void_Type
8575 or else Is_Scalar_Type (Func_Typ)
8579 -- Handle a corner case, a cross-dialect subp renaming. For example,
8580 -- an Ada 2012 renaming of an Ada 2005 subprogram. This can occur when
8581 -- an Ada 2005 (or earlier) unit references predefined run-time units.
8583 elsif Present (Alias (Func_Id)) then
8585 -- Unimplemented: a cross-dialect subp renaming which does not set
8586 -- the Alias attribute (e.g., a rename of a dereference of an access
8587 -- to subprogram value). ???
8589 return Present (Extra_Accessibility_Of_Result (Alias (Func_Id)));
8591 -- Remaining cases require Ada 2012 mode
8593 elsif Ada_Version < Ada_2012 then
8596 elsif Ekind (Func_Typ) = E_Anonymous_Access_Type
8597 or else Is_Tagged_Type (Func_Typ)
8599 -- In the case of, say, a null tagged record result type, the need
8600 -- for this extra parameter might not be obvious. This function
8601 -- returns True for all tagged types for compatibility reasons.
8602 -- A function with, say, a tagged null controlling result type might
8603 -- be overridden by a primitive of an extension having an access
8604 -- discriminant and the overrider and overridden must have compatible
8605 -- calling conventions (including implicitly declared parameters).
8606 -- Similarly, values of one access-to-subprogram type might designate
8607 -- both a primitive subprogram of a given type and a function
8608 -- which is, for example, not a primitive subprogram of any type.
8609 -- Again, this requires calling convention compatibility.
8610 -- It might be possible to solve these issues by introducing
8611 -- wrappers, but that is not the approach that was chosen.
8615 elsif Has_Unconstrained_Access_Discriminants (Func_Typ) then
8618 elsif Has_Unconstrained_Access_Discriminant_Component (Func_Typ) then
8621 -- False for all other cases
8626 end Needs_Result_Accessibility_Level;