1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, 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_Atag; use Exp_Atag;
33 with Exp_Ch2; use Exp_Ch2;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Dbug; use Exp_Dbug;
38 with Exp_Disp; use Exp_Disp;
39 with Exp_Dist; use Exp_Dist;
40 with Exp_Intr; use Exp_Intr;
41 with Exp_Pakd; use Exp_Pakd;
42 with Exp_Tss; use Exp_Tss;
43 with Exp_Util; use Exp_Util;
44 with Fname; use Fname;
45 with Freeze; use Freeze;
46 with Inline; use Inline;
48 with Namet; use Namet;
49 with Nlists; use Nlists;
50 with Nmake; use Nmake;
52 with Restrict; use Restrict;
53 with Rident; use Rident;
54 with Rtsfind; use Rtsfind;
56 with Sem_Ch6; use Sem_Ch6;
57 with Sem_Ch8; use Sem_Ch8;
58 with Sem_Ch12; use Sem_Ch12;
59 with Sem_Ch13; use Sem_Ch13;
60 with Sem_Eval; use Sem_Eval;
61 with Sem_Disp; use Sem_Disp;
62 with Sem_Dist; use Sem_Dist;
63 with Sem_Mech; use Sem_Mech;
64 with Sem_Res; use Sem_Res;
65 with Sem_Util; use Sem_Util;
66 with Sinfo; use Sinfo;
67 with Snames; use Snames;
68 with Stand; use Stand;
69 with Targparm; use Targparm;
70 with Tbuild; use Tbuild;
71 with Uintp; use Uintp;
72 with Validsw; use Validsw;
74 package body Exp_Ch6 is
76 -----------------------
77 -- Local Subprograms --
78 -----------------------
80 procedure Add_Access_Actual_To_Build_In_Place_Call
81 (Function_Call : Node_Id;
82 Function_Id : Entity_Id;
83 Return_Object : Node_Id;
84 Is_Access : Boolean := False);
85 -- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
86 -- object name given by Return_Object and add the attribute to the end of
87 -- the actual parameter list associated with the build-in-place function
88 -- call denoted by Function_Call. However, if Is_Access is True, then
89 -- Return_Object is already an access expression, in which case it's passed
90 -- along directly to the build-in-place function. Finally, if Return_Object
91 -- is empty, then pass a null literal as the actual.
93 procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
94 (Function_Call : Node_Id;
95 Function_Id : Entity_Id;
96 Alloc_Form : BIP_Allocation_Form := Unspecified;
97 Alloc_Form_Exp : Node_Id := Empty);
98 -- Ada 2005 (AI-318-02): Add an actual indicating the form of allocation,
99 -- if any, to be done by a build-in-place function. If Alloc_Form_Exp is
100 -- present, then use it, otherwise pass a literal corresponding to the
101 -- Alloc_Form parameter (which must not be Unspecified in that case).
103 procedure Add_Extra_Actual_To_Call
104 (Subprogram_Call : Node_Id;
105 Extra_Formal : Entity_Id;
106 Extra_Actual : Node_Id);
107 -- Adds Extra_Actual as a named parameter association for the formal
108 -- Extra_Formal in Subprogram_Call.
110 procedure Add_Final_List_Actual_To_Build_In_Place_Call
111 (Function_Call : Node_Id;
112 Function_Id : Entity_Id;
113 Acc_Type : Entity_Id);
114 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type has
115 -- controlled parts, add an actual parameter that is a pointer to
116 -- appropriate finalization list. The finalization list is that of the
117 -- current scope, except for "new Acc'(F(...))" in which case it's the
118 -- finalization list of the access type returned by the allocator. Acc_Type
119 -- is that type in the allocator case; Empty otherwise.
121 procedure Add_Task_Actuals_To_Build_In_Place_Call
122 (Function_Call : Node_Id;
123 Function_Id : Entity_Id;
124 Master_Actual : Node_Id);
125 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
126 -- contains tasks, add two actual parameters: the master, and a pointer to
127 -- the caller's activation chain. Master_Actual is the actual parameter
128 -- expression to pass for the master. In most cases, this is the current
129 -- master (_master). The two exceptions are: If the function call is the
130 -- initialization expression for an allocator, we pass the master of the
131 -- access type. If the function call is the initialization expression for
132 -- a return object, we pass along the master passed in by the caller. The
133 -- activation chain to pass is always the local one.
135 procedure Check_Overriding_Operation (Subp : Entity_Id);
136 -- Subp is a dispatching operation. Check whether it may override an
137 -- inherited private operation, in which case its DT entry is that of
138 -- the hidden operation, not the one it may have received earlier.
139 -- This must be done before emitting the code to set the corresponding
140 -- DT to the address of the subprogram. The actual placement of Subp in
141 -- the proper place in the list of primitive operations is done in
142 -- Declare_Inherited_Private_Subprograms, which also has to deal with
143 -- implicit operations. This duplication is unavoidable for now???
145 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
146 -- This procedure is called only if the subprogram body N, whose spec
147 -- has the given entity Spec, contains a parameterless recursive call.
148 -- It attempts to generate runtime code to detect if this a case of
149 -- infinite recursion.
151 -- The body is scanned to determine dependencies. If the only external
152 -- dependencies are on a small set of scalar variables, then the values
153 -- of these variables are captured on entry to the subprogram, and if
154 -- the values are not changed for the call, we know immediately that
155 -- we have an infinite recursion.
157 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id);
158 -- For each actual of an in-out or out parameter which is a numeric
159 -- (view) conversion of the form T (A), where A denotes a variable,
160 -- we insert the declaration:
162 -- Temp : T[ := T (A)];
164 -- prior to the call. Then we replace the actual with a reference to Temp,
165 -- and append the assignment:
167 -- A := TypeA (Temp);
169 -- after the call. Here TypeA is the actual type of variable A.
170 -- For out parameters, the initial declaration has no expression.
171 -- If A is not an entity name, we generate instead:
173 -- Var : TypeA renames A;
174 -- Temp : T := Var; -- omitting expression for out parameter.
176 -- Var := TypeA (Temp);
178 -- For other in-out parameters, we emit the required constraint checks
179 -- before and/or after the call.
181 -- For all parameter modes, actuals that denote components and slices
182 -- of packed arrays are expanded into suitable temporaries.
184 -- For non-scalar objects that are possibly unaligned, add call by copy
185 -- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
187 procedure Expand_Inlined_Call
190 Orig_Subp : Entity_Id);
191 -- If called subprogram can be inlined by the front-end, retrieve the
192 -- analyzed body, replace formals with actuals and expand call in place.
193 -- Generate thunks for actuals that are expressions, and insert the
194 -- corresponding constant declarations before the call. If the original
195 -- call is to a derived operation, the return type is the one of the
196 -- derived operation, but the body is that of the original, so return
197 -- expressions in the body must be converted to the desired type (which
198 -- is simply not noted in the tree without inline expansion).
200 function Expand_Protected_Object_Reference
202 Scop : Entity_Id) return Node_Id;
204 procedure Expand_Protected_Subprogram_Call
208 -- A call to a protected subprogram within the protected object may appear
209 -- as a regular call. The list of actuals must be expanded to contain a
210 -- reference to the object itself, and the call becomes a call to the
211 -- corresponding protected subprogram.
213 ----------------------------------------------
214 -- Add_Access_Actual_To_Build_In_Place_Call --
215 ----------------------------------------------
217 procedure Add_Access_Actual_To_Build_In_Place_Call
218 (Function_Call : Node_Id;
219 Function_Id : Entity_Id;
220 Return_Object : Node_Id;
221 Is_Access : Boolean := False)
223 Loc : constant Source_Ptr := Sloc (Function_Call);
224 Obj_Address : Node_Id;
225 Obj_Acc_Formal : Entity_Id;
228 -- Locate the implicit access parameter in the called function
230 Obj_Acc_Formal := Build_In_Place_Formal (Function_Id, BIP_Object_Access);
232 -- If no return object is provided, then pass null
234 if not Present (Return_Object) then
235 Obj_Address := Make_Null (Loc);
236 Set_Parent (Obj_Address, Function_Call);
238 -- If Return_Object is already an expression of an access type, then use
239 -- it directly, since it must be an access value denoting the return
240 -- object, and couldn't possibly be the return object itself.
243 Obj_Address := Return_Object;
244 Set_Parent (Obj_Address, Function_Call);
246 -- Apply Unrestricted_Access to caller's return object
250 Make_Attribute_Reference (Loc,
251 Prefix => Return_Object,
252 Attribute_Name => Name_Unrestricted_Access);
254 Set_Parent (Return_Object, Obj_Address);
255 Set_Parent (Obj_Address, Function_Call);
258 Analyze_And_Resolve (Obj_Address, Etype (Obj_Acc_Formal));
260 -- Build the parameter association for the new actual and add it to the
261 -- end of the function's actuals.
263 Add_Extra_Actual_To_Call (Function_Call, Obj_Acc_Formal, Obj_Address);
264 end Add_Access_Actual_To_Build_In_Place_Call;
266 --------------------------------------------------
267 -- Add_Alloc_Form_Actual_To_Build_In_Place_Call --
268 --------------------------------------------------
270 procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
271 (Function_Call : Node_Id;
272 Function_Id : Entity_Id;
273 Alloc_Form : BIP_Allocation_Form := Unspecified;
274 Alloc_Form_Exp : Node_Id := Empty)
276 Loc : constant Source_Ptr := Sloc (Function_Call);
277 Alloc_Form_Actual : Node_Id;
278 Alloc_Form_Formal : Node_Id;
281 -- The allocation form generally doesn't need to be passed in the case
282 -- of a constrained result subtype, since normally the caller performs
283 -- the allocation in that case. However this formal is still needed in
284 -- the case where the function has a tagged result, because generally
285 -- such functions can be called in a dispatching context and such calls
286 -- must be handled like calls to class-wide functions.
288 if Is_Constrained (Underlying_Type (Etype (Function_Id)))
289 and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
294 -- Locate the implicit allocation form parameter in the called function.
295 -- Maybe it would be better for each implicit formal of a build-in-place
296 -- function to have a flag or a Uint attribute to identify it. ???
298 Alloc_Form_Formal := Build_In_Place_Formal (Function_Id, BIP_Alloc_Form);
300 if Present (Alloc_Form_Exp) then
301 pragma Assert (Alloc_Form = Unspecified);
303 Alloc_Form_Actual := Alloc_Form_Exp;
306 pragma Assert (Alloc_Form /= Unspecified);
309 Make_Integer_Literal (Loc,
310 Intval => UI_From_Int (BIP_Allocation_Form'Pos (Alloc_Form)));
313 Analyze_And_Resolve (Alloc_Form_Actual, Etype (Alloc_Form_Formal));
315 -- Build the parameter association for the new actual and add it to the
316 -- end of the function's actuals.
318 Add_Extra_Actual_To_Call
319 (Function_Call, Alloc_Form_Formal, Alloc_Form_Actual);
320 end Add_Alloc_Form_Actual_To_Build_In_Place_Call;
322 ------------------------------
323 -- Add_Extra_Actual_To_Call --
324 ------------------------------
326 procedure Add_Extra_Actual_To_Call
327 (Subprogram_Call : Node_Id;
328 Extra_Formal : Entity_Id;
329 Extra_Actual : Node_Id)
331 Loc : constant Source_Ptr := Sloc (Subprogram_Call);
332 Param_Assoc : Node_Id;
336 Make_Parameter_Association (Loc,
337 Selector_Name => New_Occurrence_Of (Extra_Formal, Loc),
338 Explicit_Actual_Parameter => Extra_Actual);
340 Set_Parent (Param_Assoc, Subprogram_Call);
341 Set_Parent (Extra_Actual, Param_Assoc);
343 if Present (Parameter_Associations (Subprogram_Call)) then
344 if Nkind (Last (Parameter_Associations (Subprogram_Call))) =
345 N_Parameter_Association
348 -- Find last named actual, and append
353 L := First_Actual (Subprogram_Call);
354 while Present (L) loop
355 if No (Next_Actual (L)) then
356 Set_Next_Named_Actual (Parent (L), Extra_Actual);
364 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
367 Append (Param_Assoc, To => Parameter_Associations (Subprogram_Call));
370 Set_Parameter_Associations (Subprogram_Call, New_List (Param_Assoc));
371 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
373 end Add_Extra_Actual_To_Call;
375 --------------------------------------------------
376 -- Add_Final_List_Actual_To_Build_In_Place_Call --
377 --------------------------------------------------
379 procedure Add_Final_List_Actual_To_Build_In_Place_Call
380 (Function_Call : Node_Id;
381 Function_Id : Entity_Id;
382 Acc_Type : Entity_Id)
384 Loc : constant Source_Ptr := Sloc (Function_Call);
385 Final_List : Node_Id;
386 Final_List_Actual : Node_Id;
387 Final_List_Formal : Node_Id;
390 -- No such extra parameter is needed if there are no controlled parts.
391 -- The test for Controlled_Type accounts for class-wide results (which
392 -- potentially have controlled parts, even if the root type doesn't),
393 -- and the test for a tagged result type is needed because calls to
394 -- such a function can in general occur in dispatching contexts, which
395 -- must be treated the same as a call to class-wide functions. Both of
396 -- these situations require that a finalization list be passed.
398 if not Controlled_Type (Underlying_Type (Etype (Function_Id)))
399 and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
404 -- Locate implicit finalization list parameter in the called function
406 Final_List_Formal := Build_In_Place_Formal (Function_Id, BIP_Final_List);
408 -- Create the actual which is a pointer to the appropriate finalization
409 -- list. Acc_Type is present if and only if this call is the
410 -- initialization of an allocator. Use the Current_Scope or the Acc_Type
413 if Present (Acc_Type)
414 and then (Ekind (Acc_Type) = E_Anonymous_Access_Type
416 Present (Associated_Final_Chain (Base_Type (Acc_Type))))
418 Final_List := Find_Final_List (Acc_Type);
420 Final_List := Find_Final_List (Current_Scope);
424 Make_Attribute_Reference (Loc,
425 Prefix => Final_List,
426 Attribute_Name => Name_Unrestricted_Access);
428 Analyze_And_Resolve (Final_List_Actual, Etype (Final_List_Formal));
430 -- Build the parameter association for the new actual and add it to the
431 -- end of the function's actuals.
433 Add_Extra_Actual_To_Call
434 (Function_Call, Final_List_Formal, Final_List_Actual);
435 end Add_Final_List_Actual_To_Build_In_Place_Call;
437 ---------------------------------------------
438 -- Add_Task_Actuals_To_Build_In_Place_Call --
439 ---------------------------------------------
441 procedure Add_Task_Actuals_To_Build_In_Place_Call
442 (Function_Call : Node_Id;
443 Function_Id : Entity_Id;
444 Master_Actual : Node_Id)
445 -- Note: Master_Actual can be Empty, but only if there are no tasks
447 Loc : constant Source_Ptr := Sloc (Function_Call);
450 -- No such extra parameters are needed if there are no tasks
452 if not Has_Task (Etype (Function_Id)) then
459 Master_Formal : Node_Id;
461 -- Locate implicit master parameter in the called function
463 Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Master);
465 Analyze_And_Resolve (Master_Actual, Etype (Master_Formal));
467 -- Build the parameter association for the new actual and add it to
468 -- the end of the function's actuals.
470 Add_Extra_Actual_To_Call
471 (Function_Call, Master_Formal, Master_Actual);
474 -- The activation chain
477 Activation_Chain_Actual : Node_Id;
478 Activation_Chain_Formal : Node_Id;
480 -- Locate implicit activation chain parameter in the called function
482 Activation_Chain_Formal := Build_In_Place_Formal
483 (Function_Id, BIP_Activation_Chain);
485 -- Create the actual which is a pointer to the current activation
488 Activation_Chain_Actual :=
489 Make_Attribute_Reference (Loc,
490 Prefix => Make_Identifier (Loc, Name_uChain),
491 Attribute_Name => Name_Unrestricted_Access);
494 (Activation_Chain_Actual, Etype (Activation_Chain_Formal));
496 -- Build the parameter association for the new actual and add it to
497 -- the end of the function's actuals.
499 Add_Extra_Actual_To_Call
500 (Function_Call, Activation_Chain_Formal, Activation_Chain_Actual);
502 end Add_Task_Actuals_To_Build_In_Place_Call;
504 -----------------------
505 -- BIP_Formal_Suffix --
506 -----------------------
508 function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String is
511 when BIP_Alloc_Form =>
513 when BIP_Final_List =>
514 return "BIPfinallist";
517 when BIP_Activation_Chain =>
518 return "BIPactivationchain";
519 when BIP_Object_Access =>
522 end BIP_Formal_Suffix;
524 ---------------------------
525 -- Build_In_Place_Formal --
526 ---------------------------
528 function Build_In_Place_Formal
530 Kind : BIP_Formal_Kind) return Entity_Id
532 Extra_Formal : Entity_Id := Extra_Formals (Func);
535 -- Maybe it would be better for each implicit formal of a build-in-place
536 -- function to have a flag or a Uint attribute to identify it. ???
539 pragma Assert (Present (Extra_Formal));
541 Chars (Extra_Formal) =
542 New_External_Name (Chars (Func), BIP_Formal_Suffix (Kind));
543 Next_Formal_With_Extras (Extra_Formal);
547 end Build_In_Place_Formal;
549 --------------------------------
550 -- Check_Overriding_Operation --
551 --------------------------------
553 procedure Check_Overriding_Operation (Subp : Entity_Id) is
554 Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
555 Op_List : constant Elist_Id := Primitive_Operations (Typ);
561 if Is_Derived_Type (Typ)
562 and then not Is_Private_Type (Typ)
563 and then In_Open_Scopes (Scope (Etype (Typ)))
564 and then Typ = Base_Type (Typ)
566 -- Subp overrides an inherited private operation if there is an
567 -- inherited operation with a different name than Subp (see
568 -- Derive_Subprogram) whose Alias is a hidden subprogram with the
569 -- same name as Subp.
571 Op_Elmt := First_Elmt (Op_List);
572 while Present (Op_Elmt) loop
573 Prim_Op := Node (Op_Elmt);
574 Par_Op := Alias (Prim_Op);
577 and then not Comes_From_Source (Prim_Op)
578 and then Chars (Prim_Op) /= Chars (Par_Op)
579 and then Chars (Par_Op) = Chars (Subp)
580 and then Is_Hidden (Par_Op)
581 and then Type_Conformant (Prim_Op, Subp)
583 Set_DT_Position (Subp, DT_Position (Prim_Op));
589 end Check_Overriding_Operation;
591 -------------------------------
592 -- Detect_Infinite_Recursion --
593 -------------------------------
595 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
596 Loc : constant Source_Ptr := Sloc (N);
598 Var_List : constant Elist_Id := New_Elmt_List;
599 -- List of globals referenced by body of procedure
601 Call_List : constant Elist_Id := New_Elmt_List;
602 -- List of recursive calls in body of procedure
604 Shad_List : constant Elist_Id := New_Elmt_List;
605 -- List of entity id's for entities created to capture the value of
606 -- referenced globals on entry to the procedure.
608 Scop : constant Uint := Scope_Depth (Spec);
609 -- This is used to record the scope depth of the current procedure, so
610 -- that we can identify global references.
612 Max_Vars : constant := 4;
613 -- Do not test more than four global variables
615 Count_Vars : Natural := 0;
616 -- Count variables found so far
628 function Process (Nod : Node_Id) return Traverse_Result;
629 -- Function to traverse the subprogram body (using Traverse_Func)
635 function Process (Nod : Node_Id) return Traverse_Result is
639 if Nkind (Nod) = N_Procedure_Call_Statement then
641 -- Case of one of the detected recursive calls
643 if Is_Entity_Name (Name (Nod))
644 and then Has_Recursive_Call (Entity (Name (Nod)))
645 and then Entity (Name (Nod)) = Spec
647 Append_Elmt (Nod, Call_List);
650 -- Any other procedure call may have side effects
656 -- A call to a pure function can always be ignored
658 elsif Nkind (Nod) = N_Function_Call
659 and then Is_Entity_Name (Name (Nod))
660 and then Is_Pure (Entity (Name (Nod)))
664 -- Case of an identifier reference
666 elsif Nkind (Nod) = N_Identifier then
669 -- If no entity, then ignore the reference
671 -- Not clear why this can happen. To investigate, remove this
672 -- test and look at the crash that occurs here in 3401-004 ???
677 -- Ignore entities with no Scope, again not clear how this
678 -- can happen, to investigate, look at 4108-008 ???
680 elsif No (Scope (Ent)) then
683 -- Ignore the reference if not to a more global object
685 elsif Scope_Depth (Scope (Ent)) >= Scop then
688 -- References to types, exceptions and constants are always OK
691 or else Ekind (Ent) = E_Exception
692 or else Ekind (Ent) = E_Constant
696 -- If other than a non-volatile scalar variable, we have some
697 -- kind of global reference (e.g. to a function) that we cannot
698 -- deal with so we forget the attempt.
700 elsif Ekind (Ent) /= E_Variable
701 or else not Is_Scalar_Type (Etype (Ent))
702 or else Treat_As_Volatile (Ent)
706 -- Otherwise we have a reference to a global scalar
709 -- Loop through global entities already detected
711 Elm := First_Elmt (Var_List);
713 -- If not detected before, record this new global reference
716 Count_Vars := Count_Vars + 1;
718 if Count_Vars <= Max_Vars then
719 Append_Elmt (Entity (Nod), Var_List);
726 -- If recorded before, ignore
728 elsif Node (Elm) = Entity (Nod) then
731 -- Otherwise keep looking
741 -- For all other node kinds, recursively visit syntactic children
748 function Traverse_Body is new Traverse_Func (Process);
750 -- Start of processing for Detect_Infinite_Recursion
753 -- Do not attempt detection in No_Implicit_Conditional mode, since we
754 -- won't be able to generate the code to handle the recursion in any
757 if Restriction_Active (No_Implicit_Conditionals) then
761 -- Otherwise do traversal and quit if we get abandon signal
763 if Traverse_Body (N) = Abandon then
766 -- We must have a call, since Has_Recursive_Call was set. If not just
767 -- ignore (this is only an error check, so if we have a funny situation,
768 -- due to bugs or errors, we do not want to bomb!)
770 elsif Is_Empty_Elmt_List (Call_List) then
774 -- Here is the case where we detect recursion at compile time
776 -- Push our current scope for analyzing the declarations and code that
777 -- we will insert for the checking.
781 -- This loop builds temporary variables for each of the referenced
782 -- globals, so that at the end of the loop the list Shad_List contains
783 -- these temporaries in one-to-one correspondence with the elements in
787 Elm := First_Elmt (Var_List);
788 while Present (Elm) loop
791 Make_Defining_Identifier (Loc,
792 Chars => New_Internal_Name ('S'));
793 Append_Elmt (Ent, Shad_List);
795 -- Insert a declaration for this temporary at the start of the
796 -- declarations for the procedure. The temporaries are declared as
797 -- constant objects initialized to the current values of the
798 -- corresponding temporaries.
801 Make_Object_Declaration (Loc,
802 Defining_Identifier => Ent,
803 Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
804 Constant_Present => True,
805 Expression => New_Occurrence_Of (Var, Loc));
808 Prepend (Decl, Declarations (N));
810 Insert_After (Last, Decl);
818 -- Loop through calls
820 Call := First_Elmt (Call_List);
821 while Present (Call) loop
823 -- Build a predicate expression of the form
826 -- and then global1 = temp1
827 -- and then global2 = temp2
830 -- This predicate determines if any of the global values
831 -- referenced by the procedure have changed since the
832 -- current call, if not an infinite recursion is assured.
834 Test := New_Occurrence_Of (Standard_True, Loc);
836 Elm1 := First_Elmt (Var_List);
837 Elm2 := First_Elmt (Shad_List);
838 while Present (Elm1) loop
844 Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
845 Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
851 -- Now we replace the call with the sequence
853 -- if no-changes (see above) then
854 -- raise Storage_Error;
859 Rewrite (Node (Call),
860 Make_If_Statement (Loc,
862 Then_Statements => New_List (
863 Make_Raise_Storage_Error (Loc,
864 Reason => SE_Infinite_Recursion)),
866 Else_Statements => New_List (
867 Relocate_Node (Node (Call)))));
869 Analyze (Node (Call));
874 -- Remove temporary scope stack entry used for analysis
877 end Detect_Infinite_Recursion;
883 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id) is
884 Loc : constant Source_Ptr := Sloc (N);
889 E_Formal : Entity_Id;
891 procedure Add_Call_By_Copy_Code;
892 -- For cases where the parameter must be passed by copy, this routine
893 -- generates a temporary variable into which the actual is copied and
894 -- then passes this as the parameter. For an OUT or IN OUT parameter,
895 -- an assignment is also generated to copy the result back. The call
896 -- also takes care of any constraint checks required for the type
897 -- conversion case (on both the way in and the way out).
899 procedure Add_Simple_Call_By_Copy_Code;
900 -- This is similar to the above, but is used in cases where we know
901 -- that all that is needed is to simply create a temporary and copy
902 -- the value in and out of the temporary.
904 procedure Check_Fortran_Logical;
905 -- A value of type Logical that is passed through a formal parameter
906 -- must be normalized because .TRUE. usually does not have the same
907 -- representation as True. We assume that .FALSE. = False = 0.
908 -- What about functions that return a logical type ???
910 function Is_Legal_Copy return Boolean;
911 -- Check that an actual can be copied before generating the temporary
912 -- to be used in the call. If the actual is of a by_reference type then
913 -- the program is illegal (this can only happen in the presence of
914 -- rep. clauses that force an incorrect alignment). If the formal is
915 -- a by_reference parameter imposed by a DEC pragma, emit a warning to
916 -- the effect that this might lead to unaligned arguments.
918 function Make_Var (Actual : Node_Id) return Entity_Id;
919 -- Returns an entity that refers to the given actual parameter,
920 -- Actual (not including any type conversion). If Actual is an
921 -- entity name, then this entity is returned unchanged, otherwise
922 -- a renaming is created to provide an entity for the actual.
924 procedure Reset_Packed_Prefix;
925 -- The expansion of a packed array component reference is delayed in
926 -- the context of a call. Now we need to complete the expansion, so we
927 -- unmark the analyzed bits in all prefixes.
929 ---------------------------
930 -- Add_Call_By_Copy_Code --
931 ---------------------------
933 procedure Add_Call_By_Copy_Code is
939 F_Typ : constant Entity_Id := Etype (Formal);
944 if not Is_Legal_Copy then
949 Make_Defining_Identifier (Loc,
950 Chars => New_Internal_Name ('T'));
952 -- Use formal type for temp, unless formal type is an unconstrained
953 -- array, in which case we don't have to worry about bounds checks,
954 -- and we use the actual type, since that has appropriate bounds.
956 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
957 Indic := New_Occurrence_Of (Etype (Actual), Loc);
959 Indic := New_Occurrence_Of (Etype (Formal), Loc);
962 if Nkind (Actual) = N_Type_Conversion then
963 V_Typ := Etype (Expression (Actual));
965 -- If the formal is an (in-)out parameter, capture the name
966 -- of the variable in order to build the post-call assignment.
968 Var := Make_Var (Expression (Actual));
970 Crep := not Same_Representation
971 (F_Typ, Etype (Expression (Actual)));
974 V_Typ := Etype (Actual);
975 Var := Make_Var (Actual);
979 -- Setup initialization for case of in out parameter, or an out
980 -- parameter where the formal is an unconstrained array (in the
981 -- latter case, we have to pass in an object with bounds).
983 -- If this is an out parameter, the initial copy is wasteful, so as
984 -- an optimization for the one-dimensional case we extract the
985 -- bounds of the actual and build an uninitialized temporary of the
988 if Ekind (Formal) = E_In_Out_Parameter
989 or else (Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ))
991 if Nkind (Actual) = N_Type_Conversion then
992 if Conversion_OK (Actual) then
993 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
995 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
998 elsif Ekind (Formal) = E_Out_Parameter
999 and then Is_Array_Type (F_Typ)
1000 and then Number_Dimensions (F_Typ) = 1
1001 and then not Has_Non_Null_Base_Init_Proc (F_Typ)
1003 -- Actual is a one-dimensional array or slice, and the type
1004 -- requires no initialization. Create a temporary of the
1005 -- right size, but do not copy actual into it (optimization).
1009 Make_Subtype_Indication (Loc,
1011 New_Occurrence_Of (F_Typ, Loc),
1013 Make_Index_Or_Discriminant_Constraint (Loc,
1014 Constraints => New_List (
1017 Make_Attribute_Reference (Loc,
1018 Prefix => New_Occurrence_Of (Var, Loc),
1019 Attribute_name => Name_First),
1021 Make_Attribute_Reference (Loc,
1022 Prefix => New_Occurrence_Of (Var, Loc),
1023 Attribute_Name => Name_Last)))));
1026 Init := New_Occurrence_Of (Var, Loc);
1029 -- An initialization is created for packed conversions as
1030 -- actuals for out parameters to enable Make_Object_Declaration
1031 -- to determine the proper subtype for N_Node. Note that this
1032 -- is wasteful because the extra copying on the call side is
1033 -- not required for such out parameters. ???
1035 elsif Ekind (Formal) = E_Out_Parameter
1036 and then Nkind (Actual) = N_Type_Conversion
1037 and then (Is_Bit_Packed_Array (F_Typ)
1039 Is_Bit_Packed_Array (Etype (Expression (Actual))))
1041 if Conversion_OK (Actual) then
1042 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1044 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1047 elsif Ekind (Formal) = E_In_Parameter then
1049 -- Handle the case in which the actual is a type conversion
1051 if Nkind (Actual) = N_Type_Conversion then
1052 if Conversion_OK (Actual) then
1053 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1055 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1058 Init := New_Occurrence_Of (Var, Loc);
1066 Make_Object_Declaration (Loc,
1067 Defining_Identifier => Temp,
1068 Object_Definition => Indic,
1069 Expression => Init);
1070 Set_Assignment_OK (N_Node);
1071 Insert_Action (N, N_Node);
1073 -- Now, normally the deal here is that we use the defining
1074 -- identifier created by that object declaration. There is
1075 -- one exception to this. In the change of representation case
1076 -- the above declaration will end up looking like:
1078 -- temp : type := identifier;
1080 -- And in this case we might as well use the identifier directly
1081 -- and eliminate the temporary. Note that the analysis of the
1082 -- declaration was not a waste of time in that case, since it is
1083 -- what generated the necessary change of representation code. If
1084 -- the change of representation introduced additional code, as in
1085 -- a fixed-integer conversion, the expression is not an identifier
1086 -- and must be kept.
1089 and then Present (Expression (N_Node))
1090 and then Is_Entity_Name (Expression (N_Node))
1092 Temp := Entity (Expression (N_Node));
1093 Rewrite (N_Node, Make_Null_Statement (Loc));
1096 -- For IN parameter, all we do is to replace the actual
1098 if Ekind (Formal) = E_In_Parameter then
1099 Rewrite (Actual, New_Reference_To (Temp, Loc));
1102 -- Processing for OUT or IN OUT parameter
1105 -- Kill current value indications for the temporary variable we
1106 -- created, since we just passed it as an OUT parameter.
1108 Kill_Current_Values (Temp);
1110 -- If type conversion, use reverse conversion on exit
1112 if Nkind (Actual) = N_Type_Conversion then
1113 if Conversion_OK (Actual) then
1114 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1116 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1119 Expr := New_Occurrence_Of (Temp, Loc);
1122 Rewrite (Actual, New_Reference_To (Temp, Loc));
1125 -- If the actual is a conversion of a packed reference, it may
1126 -- already have been expanded by Remove_Side_Effects, and the
1127 -- resulting variable is a temporary which does not designate
1128 -- the proper out-parameter, which may not be addressable. In
1129 -- that case, generate an assignment to the original expression
1130 -- (before expansion of the packed reference) so that the proper
1131 -- expansion of assignment to a packed component can take place.
1138 if Is_Renaming_Of_Object (Var)
1139 and then Nkind (Renamed_Object (Var)) = N_Selected_Component
1140 and then Is_Entity_Name (Prefix (Renamed_Object (Var)))
1141 and then Nkind (Original_Node (Prefix (Renamed_Object (Var))))
1142 = N_Indexed_Component
1144 Has_Non_Standard_Rep (Etype (Prefix (Renamed_Object (Var))))
1146 Obj := Renamed_Object (Var);
1148 Make_Selected_Component (Loc,
1150 New_Copy_Tree (Original_Node (Prefix (Obj))),
1151 Selector_Name => New_Copy (Selector_Name (Obj)));
1152 Reset_Analyzed_Flags (Lhs);
1155 Lhs := New_Occurrence_Of (Var, Loc);
1158 Set_Assignment_OK (Lhs);
1160 Append_To (Post_Call,
1161 Make_Assignment_Statement (Loc,
1163 Expression => Expr));
1167 end Add_Call_By_Copy_Code;
1169 ----------------------------------
1170 -- Add_Simple_Call_By_Copy_Code --
1171 ----------------------------------
1173 procedure Add_Simple_Call_By_Copy_Code is
1181 F_Typ : constant Entity_Id := Etype (Formal);
1184 if not Is_Legal_Copy then
1188 -- Use formal type for temp, unless formal type is an unconstrained
1189 -- array, in which case we don't have to worry about bounds checks,
1190 -- and we use the actual type, since that has appropriate bounds.
1192 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
1193 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1195 Indic := New_Occurrence_Of (Etype (Formal), Loc);
1198 -- Prepare to generate code
1200 Reset_Packed_Prefix;
1203 Make_Defining_Identifier (Loc,
1204 Chars => New_Internal_Name ('T'));
1205 Incod := Relocate_Node (Actual);
1206 Outcod := New_Copy_Tree (Incod);
1208 -- Generate declaration of temporary variable, initializing it
1209 -- with the input parameter unless we have an OUT formal or
1210 -- this is an initialization call.
1212 -- If the formal is an out parameter with discriminants, the
1213 -- discriminants must be captured even if the rest of the object
1214 -- is in principle uninitialized, because the discriminants may
1215 -- be read by the called subprogram.
1217 if Ekind (Formal) = E_Out_Parameter then
1220 if Has_Discriminants (Etype (Formal)) then
1221 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1224 elsif Inside_Init_Proc then
1226 -- Could use a comment here to match comment below ???
1228 if Nkind (Actual) /= N_Selected_Component
1230 not Has_Discriminant_Dependent_Constraint
1231 (Entity (Selector_Name (Actual)))
1235 -- Otherwise, keep the component in order to generate the proper
1236 -- actual subtype, that depends on enclosing discriminants.
1244 Make_Object_Declaration (Loc,
1245 Defining_Identifier => Temp,
1246 Object_Definition => Indic,
1247 Expression => Incod);
1252 -- If the call is to initialize a component of a composite type,
1253 -- and the component does not depend on discriminants, use the
1254 -- actual type of the component. This is required in case the
1255 -- component is constrained, because in general the formal of the
1256 -- initialization procedure will be unconstrained. Note that if
1257 -- the component being initialized is constrained by an enclosing
1258 -- discriminant, the presence of the initialization in the
1259 -- declaration will generate an expression for the actual subtype.
1261 Set_No_Initialization (Decl);
1262 Set_Object_Definition (Decl,
1263 New_Occurrence_Of (Etype (Actual), Loc));
1266 Insert_Action (N, Decl);
1268 -- The actual is simply a reference to the temporary
1270 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
1272 -- Generate copy out if OUT or IN OUT parameter
1274 if Ekind (Formal) /= E_In_Parameter then
1276 Rhs := New_Occurrence_Of (Temp, Loc);
1278 -- Deal with conversion
1280 if Nkind (Lhs) = N_Type_Conversion then
1281 Lhs := Expression (Lhs);
1282 Rhs := Convert_To (Etype (Actual), Rhs);
1285 Append_To (Post_Call,
1286 Make_Assignment_Statement (Loc,
1288 Expression => Rhs));
1289 Set_Assignment_OK (Name (Last (Post_Call)));
1291 end Add_Simple_Call_By_Copy_Code;
1293 ---------------------------
1294 -- Check_Fortran_Logical --
1295 ---------------------------
1297 procedure Check_Fortran_Logical is
1298 Logical : constant Entity_Id := Etype (Formal);
1301 -- Note: this is very incomplete, e.g. it does not handle arrays
1302 -- of logical values. This is really not the right approach at all???)
1305 if Convention (Subp) = Convention_Fortran
1306 and then Root_Type (Etype (Formal)) = Standard_Boolean
1307 and then Ekind (Formal) /= E_In_Parameter
1309 Var := Make_Var (Actual);
1310 Append_To (Post_Call,
1311 Make_Assignment_Statement (Loc,
1312 Name => New_Occurrence_Of (Var, Loc),
1314 Unchecked_Convert_To (
1317 Left_Opnd => New_Occurrence_Of (Var, Loc),
1319 Unchecked_Convert_To (
1321 New_Occurrence_Of (Standard_False, Loc))))));
1323 end Check_Fortran_Logical;
1329 function Is_Legal_Copy return Boolean is
1331 -- An attempt to copy a value of such a type can only occur if
1332 -- representation clauses give the actual a misaligned address.
1334 if Is_By_Reference_Type (Etype (Formal)) then
1336 ("misaligned actual cannot be passed by reference", Actual);
1339 -- For users of Starlet, we assume that the specification of by-
1340 -- reference mechanism is mandatory. This may lead to unaligned
1341 -- objects but at least for DEC legacy code it is known to work.
1342 -- The warning will alert users of this code that a problem may
1345 elsif Mechanism (Formal) = By_Reference
1346 and then Is_Valued_Procedure (Scope (Formal))
1349 ("by_reference actual may be misaligned?", Actual);
1361 function Make_Var (Actual : Node_Id) return Entity_Id is
1365 if Is_Entity_Name (Actual) then
1366 return Entity (Actual);
1370 Make_Defining_Identifier (Loc,
1371 Chars => New_Internal_Name ('T'));
1374 Make_Object_Renaming_Declaration (Loc,
1375 Defining_Identifier => Var,
1377 New_Occurrence_Of (Etype (Actual), Loc),
1378 Name => Relocate_Node (Actual));
1380 Insert_Action (N, N_Node);
1385 -------------------------
1386 -- Reset_Packed_Prefix --
1387 -------------------------
1389 procedure Reset_Packed_Prefix is
1390 Pfx : Node_Id := Actual;
1393 Set_Analyzed (Pfx, False);
1394 exit when Nkind (Pfx) /= N_Selected_Component
1395 and then Nkind (Pfx) /= N_Indexed_Component;
1396 Pfx := Prefix (Pfx);
1398 end Reset_Packed_Prefix;
1400 -- Start of processing for Expand_Actuals
1403 Post_Call := New_List;
1405 Formal := First_Formal (Subp);
1406 Actual := First_Actual (N);
1407 while Present (Formal) loop
1408 E_Formal := Etype (Formal);
1410 if Is_Scalar_Type (E_Formal)
1411 or else Nkind (Actual) = N_Slice
1413 Check_Fortran_Logical;
1417 elsif Ekind (Formal) /= E_Out_Parameter then
1419 -- The unusual case of the current instance of a protected type
1420 -- requires special handling. This can only occur in the context
1421 -- of a call within the body of a protected operation.
1423 if Is_Entity_Name (Actual)
1424 and then Ekind (Entity (Actual)) = E_Protected_Type
1425 and then In_Open_Scopes (Entity (Actual))
1427 if Scope (Subp) /= Entity (Actual) then
1428 Error_Msg_N ("operation outside protected type may not "
1429 & "call back its protected operations?", Actual);
1433 Expand_Protected_Object_Reference (N, Entity (Actual)));
1436 -- Ada 2005 (AI-318-02): If the actual parameter is a call to a
1437 -- build-in-place function, then a temporary return object needs
1438 -- to be created and access to it must be passed to the function.
1439 -- Currently we limit such functions to those with inherently
1440 -- limited result subtypes, but eventually we plan to expand the
1441 -- functions that are treated as build-in-place to include other
1442 -- composite result types.
1444 if Ada_Version >= Ada_05
1445 and then Is_Build_In_Place_Function_Call (Actual)
1447 Make_Build_In_Place_Call_In_Anonymous_Context (Actual);
1450 Apply_Constraint_Check (Actual, E_Formal);
1452 -- Out parameter case. No constraint checks on access type
1455 elsif Is_Access_Type (E_Formal) then
1460 elsif Has_Discriminants (Base_Type (E_Formal))
1461 or else Has_Non_Null_Base_Init_Proc (E_Formal)
1463 Apply_Constraint_Check (Actual, E_Formal);
1468 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
1471 -- Processing for IN-OUT and OUT parameters
1473 if Ekind (Formal) /= E_In_Parameter then
1475 -- For type conversions of arrays, apply length/range checks
1477 if Is_Array_Type (E_Formal)
1478 and then Nkind (Actual) = N_Type_Conversion
1480 if Is_Constrained (E_Formal) then
1481 Apply_Length_Check (Expression (Actual), E_Formal);
1483 Apply_Range_Check (Expression (Actual), E_Formal);
1487 -- If argument is a type conversion for a type that is passed
1488 -- by copy, then we must pass the parameter by copy.
1490 if Nkind (Actual) = N_Type_Conversion
1492 (Is_Numeric_Type (E_Formal)
1493 or else Is_Access_Type (E_Formal)
1494 or else Is_Enumeration_Type (E_Formal)
1495 or else Is_Bit_Packed_Array (Etype (Formal))
1496 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
1498 -- Also pass by copy if change of representation
1500 or else not Same_Representation
1502 Etype (Expression (Actual))))
1504 Add_Call_By_Copy_Code;
1506 -- References to components of bit packed arrays are expanded
1507 -- at this point, rather than at the point of analysis of the
1508 -- actuals, to handle the expansion of the assignment to
1509 -- [in] out parameters.
1511 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1512 Add_Simple_Call_By_Copy_Code;
1514 -- If a non-scalar actual is possibly bit-aligned, we need a copy
1515 -- because the back-end cannot cope with such objects. In other
1516 -- cases where alignment forces a copy, the back-end generates
1517 -- it properly. It should not be generated unconditionally in the
1518 -- front-end because it does not know precisely the alignment
1519 -- requirements of the target, and makes too conservative an
1520 -- estimate, leading to superfluous copies or spurious errors
1521 -- on by-reference parameters.
1523 elsif Nkind (Actual) = N_Selected_Component
1525 Component_May_Be_Bit_Aligned (Entity (Selector_Name (Actual)))
1526 and then not Represented_As_Scalar (Etype (Formal))
1528 Add_Simple_Call_By_Copy_Code;
1530 -- References to slices of bit packed arrays are expanded
1532 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1533 Add_Call_By_Copy_Code;
1535 -- References to possibly unaligned slices of arrays are expanded
1537 elsif Is_Possibly_Unaligned_Slice (Actual) then
1538 Add_Call_By_Copy_Code;
1540 -- Deal with access types where the actual subtype and the
1541 -- formal subtype are not the same, requiring a check.
1543 -- It is necessary to exclude tagged types because of "downward
1544 -- conversion" errors and a strange assertion error in namet
1545 -- from gnatf in bug 1215-001 ???
1547 elsif Is_Access_Type (E_Formal)
1548 and then not Same_Type (E_Formal, Etype (Actual))
1549 and then not Is_Tagged_Type (Designated_Type (E_Formal))
1551 Add_Call_By_Copy_Code;
1553 -- If the actual is not a scalar and is marked for volatile
1554 -- treatment, whereas the formal is not volatile, then pass
1555 -- by copy unless it is a by-reference type.
1557 elsif Is_Entity_Name (Actual)
1558 and then Treat_As_Volatile (Entity (Actual))
1559 and then not Is_By_Reference_Type (Etype (Actual))
1560 and then not Is_Scalar_Type (Etype (Entity (Actual)))
1561 and then not Treat_As_Volatile (E_Formal)
1563 Add_Call_By_Copy_Code;
1565 elsif Nkind (Actual) = N_Indexed_Component
1566 and then Is_Entity_Name (Prefix (Actual))
1567 and then Has_Volatile_Components (Entity (Prefix (Actual)))
1569 Add_Call_By_Copy_Code;
1572 -- Processing for IN parameters
1575 -- For IN parameters is in the packed array case, we expand an
1576 -- indexed component (the circuit in Exp_Ch4 deliberately left
1577 -- indexed components appearing as actuals untouched, so that
1578 -- the special processing above for the OUT and IN OUT cases
1579 -- could be performed. We could make the test in Exp_Ch4 more
1580 -- complex and have it detect the parameter mode, but it is
1581 -- easier simply to handle all cases here.)
1583 if Nkind (Actual) = N_Indexed_Component
1584 and then Is_Packed (Etype (Prefix (Actual)))
1586 Reset_Packed_Prefix;
1587 Expand_Packed_Element_Reference (Actual);
1589 -- If we have a reference to a bit packed array, we copy it,
1590 -- since the actual must be byte aligned.
1592 -- Is this really necessary in all cases???
1594 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1595 Add_Simple_Call_By_Copy_Code;
1597 -- If a non-scalar actual is possibly unaligned, we need a copy
1599 elsif Is_Possibly_Unaligned_Object (Actual)
1600 and then not Represented_As_Scalar (Etype (Formal))
1602 Add_Simple_Call_By_Copy_Code;
1604 -- Similarly, we have to expand slices of packed arrays here
1605 -- because the result must be byte aligned.
1607 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1608 Add_Call_By_Copy_Code;
1610 -- Only processing remaining is to pass by copy if this is a
1611 -- reference to a possibly unaligned slice, since the caller
1612 -- expects an appropriately aligned argument.
1614 elsif Is_Possibly_Unaligned_Slice (Actual) then
1615 Add_Call_By_Copy_Code;
1619 Next_Formal (Formal);
1620 Next_Actual (Actual);
1623 -- Find right place to put post call stuff if it is present
1625 if not Is_Empty_List (Post_Call) then
1627 -- If call is not a list member, it must be the triggering statement
1628 -- of a triggering alternative or an entry call alternative, and we
1629 -- can add the post call stuff to the corresponding statement list.
1631 if not Is_List_Member (N) then
1633 P : constant Node_Id := Parent (N);
1636 pragma Assert (Nkind (P) = N_Triggering_Alternative
1637 or else Nkind (P) = N_Entry_Call_Alternative);
1639 if Is_Non_Empty_List (Statements (P)) then
1640 Insert_List_Before_And_Analyze
1641 (First (Statements (P)), Post_Call);
1643 Set_Statements (P, Post_Call);
1647 -- Otherwise, normal case where N is in a statement sequence,
1648 -- just put the post-call stuff after the call statement.
1651 Insert_Actions_After (N, Post_Call);
1655 -- The call node itself is re-analyzed in Expand_Call
1663 -- This procedure handles expansion of function calls and procedure call
1664 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1665 -- Expand_N_Procedure_Call_Statement. Processing for calls includes:
1667 -- Replace call to Raise_Exception by Raise_Exception always if possible
1668 -- Provide values of actuals for all formals in Extra_Formals list
1669 -- Replace "call" to enumeration literal function by literal itself
1670 -- Rewrite call to predefined operator as operator
1671 -- Replace actuals to in-out parameters that are numeric conversions,
1672 -- with explicit assignment to temporaries before and after the call.
1673 -- Remove optional actuals if First_Optional_Parameter specified.
1675 -- Note that the list of actuals has been filled with default expressions
1676 -- during semantic analysis of the call. Only the extra actuals required
1677 -- for the 'Constrained attribute and for accessibility checks are added
1680 procedure Expand_Call (N : Node_Id) is
1681 Loc : constant Source_Ptr := Sloc (N);
1682 Remote : constant Boolean := Is_Remote_Call (N);
1684 Orig_Subp : Entity_Id := Empty;
1685 Parent_Subp : Entity_Id;
1686 Parent_Formal : Entity_Id;
1689 Prev : Node_Id := Empty;
1691 Prev_Orig : Node_Id;
1692 -- Original node for an actual, which may have been rewritten. If the
1693 -- actual is a function call that has been transformed from a selected
1694 -- component, the original node is unanalyzed. Otherwise, it carries
1695 -- semantic information used to generate additional actuals.
1698 Extra_Actuals : List_Id := No_List;
1700 CW_Interface_Formals_Present : Boolean := False;
1702 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1703 -- Adds one entry to the end of the actual parameter list. Used for
1704 -- default parameters and for extra actuals (for Extra_Formals). The
1705 -- argument is an N_Parameter_Association node.
1707 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1708 -- Adds an extra actual to the list of extra actuals. Expr is the
1709 -- expression for the value of the actual, EF is the entity for the
1712 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1713 -- Within an instance, a type derived from a non-tagged formal derived
1714 -- type inherits from the original parent, not from the actual. This is
1715 -- tested in 4723-003. The current derivation mechanism has the derived
1716 -- type inherit from the actual, which is only correct outside of the
1717 -- instance. If the subprogram is inherited, we test for this particular
1718 -- case through a convoluted tree traversal before setting the proper
1719 -- subprogram to be called.
1721 --------------------------
1722 -- Add_Actual_Parameter --
1723 --------------------------
1725 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1726 Actual_Expr : constant Node_Id :=
1727 Explicit_Actual_Parameter (Insert_Param);
1730 -- Case of insertion is first named actual
1732 if No (Prev) or else
1733 Nkind (Parent (Prev)) /= N_Parameter_Association
1735 Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
1736 Set_First_Named_Actual (N, Actual_Expr);
1739 if No (Parameter_Associations (N)) then
1740 Set_Parameter_Associations (N, New_List);
1741 Append (Insert_Param, Parameter_Associations (N));
1744 Insert_After (Prev, Insert_Param);
1747 -- Case of insertion is not first named actual
1750 Set_Next_Named_Actual
1751 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1752 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1753 Append (Insert_Param, Parameter_Associations (N));
1756 Prev := Actual_Expr;
1757 end Add_Actual_Parameter;
1759 ----------------------
1760 -- Add_Extra_Actual --
1761 ----------------------
1763 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1764 Loc : constant Source_Ptr := Sloc (Expr);
1767 if Extra_Actuals = No_List then
1768 Extra_Actuals := New_List;
1769 Set_Parent (Extra_Actuals, N);
1772 Append_To (Extra_Actuals,
1773 Make_Parameter_Association (Loc,
1774 Explicit_Actual_Parameter => Expr,
1776 Make_Identifier (Loc, Chars (EF))));
1778 Analyze_And_Resolve (Expr, Etype (EF));
1779 end Add_Extra_Actual;
1781 ---------------------------
1782 -- Inherited_From_Formal --
1783 ---------------------------
1785 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1787 Gen_Par : Entity_Id;
1788 Gen_Prim : Elist_Id;
1793 -- If the operation is inherited, it is attached to the corresponding
1794 -- type derivation. If the parent in the derivation is a generic
1795 -- actual, it is a subtype of the actual, and we have to recover the
1796 -- original derived type declaration to find the proper parent.
1798 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1799 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1800 or else Nkind (Type_Definition (Original_Node (Parent (S)))) /=
1801 N_Derived_Type_Definition
1802 or else not In_Instance
1809 (Type_Definition (Original_Node (Parent (S)))));
1811 if Nkind (Indic) = N_Subtype_Indication then
1812 Par := Entity (Subtype_Mark (Indic));
1814 Par := Entity (Indic);
1818 if not Is_Generic_Actual_Type (Par)
1819 or else Is_Tagged_Type (Par)
1820 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1821 or else not In_Open_Scopes (Scope (Par))
1826 Gen_Par := Generic_Parent_Type (Parent (Par));
1829 -- If the actual has no generic parent type, the formal is not
1830 -- a formal derived type, so nothing to inherit.
1832 if No (Gen_Par) then
1836 -- If the generic parent type is still the generic type, this is a
1837 -- private formal, not a derived formal, and there are no operations
1838 -- inherited from the formal.
1840 if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
1844 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
1846 Elmt := First_Elmt (Gen_Prim);
1847 while Present (Elmt) loop
1848 if Chars (Node (Elmt)) = Chars (S) then
1854 F1 := First_Formal (S);
1855 F2 := First_Formal (Node (Elmt));
1857 and then Present (F2)
1859 if Etype (F1) = Etype (F2)
1860 or else Etype (F2) = Gen_Par
1866 exit; -- not the right subprogram
1878 raise Program_Error;
1879 end Inherited_From_Formal;
1881 -- Start of processing for Expand_Call
1884 -- Ignore if previous error
1886 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1890 -- Call using access to subprogram with explicit dereference
1892 if Nkind (Name (N)) = N_Explicit_Dereference then
1893 Subp := Etype (Name (N));
1894 Parent_Subp := Empty;
1896 -- Case of call to simple entry, where the Name is a selected component
1897 -- whose prefix is the task, and whose selector name is the entry name
1899 elsif Nkind (Name (N)) = N_Selected_Component then
1900 Subp := Entity (Selector_Name (Name (N)));
1901 Parent_Subp := Empty;
1903 -- Case of call to member of entry family, where Name is an indexed
1904 -- component, with the prefix being a selected component giving the
1905 -- task and entry family name, and the index being the entry index.
1907 elsif Nkind (Name (N)) = N_Indexed_Component then
1908 Subp := Entity (Selector_Name (Prefix (Name (N))));
1909 Parent_Subp := Empty;
1914 Subp := Entity (Name (N));
1915 Parent_Subp := Alias (Subp);
1917 -- Replace call to Raise_Exception by call to Raise_Exception_Always
1918 -- if we can tell that the first parameter cannot possibly be null.
1919 -- This helps optimization and also generation of warnings.
1921 -- We do not do this if Raise_Exception_Always does not exist, which
1922 -- can happen in configurable run time profiles which provide only a
1923 -- Raise_Exception, which is in fact an unconditional raise anyway.
1925 if Is_RTE (Subp, RE_Raise_Exception)
1926 and then RTE_Available (RE_Raise_Exception_Always)
1929 FA : constant Node_Id := Original_Node (First_Actual (N));
1932 -- The case we catch is where the first argument is obtained
1933 -- using the Identity attribute (which must always be
1936 if Nkind (FA) = N_Attribute_Reference
1937 and then Attribute_Name (FA) = Name_Identity
1939 Subp := RTE (RE_Raise_Exception_Always);
1940 Set_Name (N, New_Occurrence_Of (Subp, Loc));
1945 if Ekind (Subp) = E_Entry then
1946 Parent_Subp := Empty;
1950 -- Ada 2005 (AI-345): We have a procedure call as a triggering
1951 -- alternative in an asynchronous select or as an entry call in
1952 -- a conditional or timed select. Check whether the procedure call
1953 -- is a renaming of an entry and rewrite it as an entry call.
1955 if Ada_Version >= Ada_05
1956 and then Nkind (N) = N_Procedure_Call_Statement
1958 ((Nkind (Parent (N)) = N_Triggering_Alternative
1959 and then Triggering_Statement (Parent (N)) = N)
1961 (Nkind (Parent (N)) = N_Entry_Call_Alternative
1962 and then Entry_Call_Statement (Parent (N)) = N))
1966 Ren_Root : Entity_Id := Subp;
1969 -- This may be a chain of renamings, find the root
1971 if Present (Alias (Ren_Root)) then
1972 Ren_Root := Alias (Ren_Root);
1975 if Present (Original_Node (Parent (Parent (Ren_Root)))) then
1976 Ren_Decl := Original_Node (Parent (Parent (Ren_Root)));
1978 if Nkind (Ren_Decl) = N_Subprogram_Renaming_Declaration then
1980 Make_Entry_Call_Statement (Loc,
1982 New_Copy_Tree (Name (Ren_Decl)),
1983 Parameter_Associations =>
1984 New_Copy_List_Tree (Parameter_Associations (N))));
1992 -- First step, compute extra actuals, corresponding to any
1993 -- Extra_Formals present. Note that we do not access Extra_Formals
1994 -- directly, instead we simply note the presence of the extra
1995 -- formals as we process the regular formals and collect the
1996 -- corresponding actuals in Extra_Actuals.
1998 -- We also generate any required range checks for actuals as we go
1999 -- through the loop, since this is a convenient place to do this.
2001 Formal := First_Formal (Subp);
2002 Actual := First_Actual (N);
2003 while Present (Formal) loop
2005 -- Generate range check if required (not activated yet ???)
2007 -- if Do_Range_Check (Actual) then
2008 -- Set_Do_Range_Check (Actual, False);
2009 -- Generate_Range_Check
2010 -- (Actual, Etype (Formal), CE_Range_Check_Failed);
2013 -- Prepare to examine current entry
2016 Prev_Orig := Original_Node (Prev);
2018 -- The original actual may have been a call written in prefix
2019 -- form, and rewritten before analysis.
2021 if not Analyzed (Prev_Orig)
2023 (Nkind (Actual) = N_Function_Call
2025 Nkind (Actual) = N_Identifier)
2030 -- Ada 2005 (AI-251): Check if any formal is a class-wide interface
2031 -- to expand it in a further round.
2033 CW_Interface_Formals_Present :=
2034 CW_Interface_Formals_Present
2036 (Ekind (Etype (Formal)) = E_Class_Wide_Type
2037 and then Is_Interface (Etype (Etype (Formal))))
2039 (Ekind (Etype (Formal)) = E_Anonymous_Access_Type
2040 and then Is_Interface (Directly_Designated_Type
2041 (Etype (Etype (Formal)))));
2043 -- Create possible extra actual for constrained case. Usually, the
2044 -- extra actual is of the form actual'constrained, but since this
2045 -- attribute is only available for unconstrained records, TRUE is
2046 -- expanded if the type of the formal happens to be constrained (for
2047 -- instance when this procedure is inherited from an unconstrained
2048 -- record to a constrained one) or if the actual has no discriminant
2049 -- (its type is constrained). An exception to this is the case of a
2050 -- private type without discriminants. In this case we pass FALSE
2051 -- because the object has underlying discriminants with defaults.
2053 if Present (Extra_Constrained (Formal)) then
2054 if Ekind (Etype (Prev)) in Private_Kind
2055 and then not Has_Discriminants (Base_Type (Etype (Prev)))
2058 New_Occurrence_Of (Standard_False, Loc),
2059 Extra_Constrained (Formal));
2061 elsif Is_Constrained (Etype (Formal))
2062 or else not Has_Discriminants (Etype (Prev))
2065 New_Occurrence_Of (Standard_True, Loc),
2066 Extra_Constrained (Formal));
2068 -- Do not produce extra actuals for Unchecked_Union parameters.
2069 -- Jump directly to the end of the loop.
2071 elsif Is_Unchecked_Union (Base_Type (Etype (Actual))) then
2072 goto Skip_Extra_Actual_Generation;
2075 -- If the actual is a type conversion, then the constrained
2076 -- test applies to the actual, not the target type.
2082 -- Test for unchecked conversions as well, which can occur
2083 -- as out parameter actuals on calls to stream procedures.
2086 while Nkind (Act_Prev) = N_Type_Conversion
2087 or else Nkind (Act_Prev) = N_Unchecked_Type_Conversion
2089 Act_Prev := Expression (Act_Prev);
2092 -- If the expression is a conversion of a dereference,
2093 -- this is internally generated code that manipulates
2094 -- addresses, e.g. when building interface tables. No
2095 -- check should occur in this case, and the discriminated
2096 -- object is not directly a hand.
2098 if not Comes_From_Source (Actual)
2099 and then Nkind (Actual) = N_Unchecked_Type_Conversion
2100 and then Nkind (Act_Prev) = N_Explicit_Dereference
2103 (New_Occurrence_Of (Standard_False, Loc),
2104 Extra_Constrained (Formal));
2108 (Make_Attribute_Reference (Sloc (Prev),
2110 Duplicate_Subexpr_No_Checks
2111 (Act_Prev, Name_Req => True),
2112 Attribute_Name => Name_Constrained),
2113 Extra_Constrained (Formal));
2119 -- Create possible extra actual for accessibility level
2121 if Present (Extra_Accessibility (Formal)) then
2123 -- Ada 2005 (AI-252): If the actual was rewritten as an Access
2124 -- attribute, then the original actual may be an aliased object
2125 -- occurring as the prefix in a call using "Object.Operation"
2126 -- notation. In that case we must pass the level of the object,
2127 -- so Prev_Orig is reset to Prev and the attribute will be
2128 -- processed by the code for Access attributes further below.
2130 if Prev_Orig /= Prev
2131 and then Nkind (Prev) = N_Attribute_Reference
2133 Get_Attribute_Id (Attribute_Name (Prev)) = Attribute_Access
2134 and then Is_Aliased_View (Prev_Orig)
2139 if Is_Entity_Name (Prev_Orig) then
2141 -- When passing an access parameter, or a renaming of an access
2142 -- parameter, as the actual to another access parameter we need
2143 -- to pass along the actual's own access level parameter. This
2144 -- is done if we are within the scope of the formal access
2145 -- parameter (if this is an inlined body the extra formal is
2148 if (Is_Formal (Entity (Prev_Orig))
2150 (Present (Renamed_Object (Entity (Prev_Orig)))
2152 Is_Entity_Name (Renamed_Object (Entity (Prev_Orig)))
2155 (Entity (Renamed_Object (Entity (Prev_Orig))))))
2156 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
2157 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
2160 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
2163 pragma Assert (Present (Parm_Ent));
2165 if Present (Extra_Accessibility (Parm_Ent)) then
2168 (Extra_Accessibility (Parm_Ent), Loc),
2169 Extra_Accessibility (Formal));
2171 -- If the actual access parameter does not have an
2172 -- associated extra formal providing its scope level,
2173 -- then treat the actual as having library-level
2178 (Make_Integer_Literal (Loc,
2179 Intval => Scope_Depth (Standard_Standard)),
2180 Extra_Accessibility (Formal));
2184 -- The actual is a normal access value, so just pass the level
2185 -- of the actual's access type.
2189 (Make_Integer_Literal (Loc,
2190 Intval => Type_Access_Level (Etype (Prev_Orig))),
2191 Extra_Accessibility (Formal));
2195 case Nkind (Prev_Orig) is
2197 when N_Attribute_Reference =>
2199 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
2201 -- For X'Access, pass on the level of the prefix X
2203 when Attribute_Access =>
2205 Make_Integer_Literal (Loc,
2207 Object_Access_Level (Prefix (Prev_Orig))),
2208 Extra_Accessibility (Formal));
2210 -- Treat the unchecked attributes as library-level
2212 when Attribute_Unchecked_Access |
2213 Attribute_Unrestricted_Access =>
2215 Make_Integer_Literal (Loc,
2216 Intval => Scope_Depth (Standard_Standard)),
2217 Extra_Accessibility (Formal));
2219 -- No other cases of attributes returning access
2220 -- values that can be passed to access parameters
2223 raise Program_Error;
2227 -- For allocators we pass the level of the execution of
2228 -- the called subprogram, which is one greater than the
2229 -- current scope level.
2233 Make_Integer_Literal (Loc,
2234 Scope_Depth (Current_Scope) + 1),
2235 Extra_Accessibility (Formal));
2237 -- For other cases we simply pass the level of the
2238 -- actual's access type.
2242 Make_Integer_Literal (Loc,
2243 Intval => Type_Access_Level (Etype (Prev_Orig))),
2244 Extra_Accessibility (Formal));
2250 -- Perform the check of 4.6(49) that prevents a null value from being
2251 -- passed as an actual to an access parameter. Note that the check is
2252 -- elided in the common cases of passing an access attribute or
2253 -- access parameter as an actual. Also, we currently don't enforce
2254 -- this check for expander-generated actuals and when -gnatdj is set.
2256 if Ada_Version >= Ada_05 then
2258 -- Ada 2005 (AI-231): Check null-excluding access types
2260 if Is_Access_Type (Etype (Formal))
2261 and then Can_Never_Be_Null (Etype (Formal))
2262 and then Nkind (Prev) /= N_Raise_Constraint_Error
2263 and then (Known_Null (Prev)
2264 or else not Can_Never_Be_Null (Etype (Prev)))
2266 Install_Null_Excluding_Check (Prev);
2269 -- Ada_Version < Ada_05
2272 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
2273 or else Access_Checks_Suppressed (Subp)
2277 elsif Debug_Flag_J then
2280 elsif not Comes_From_Source (Prev) then
2283 elsif Is_Entity_Name (Prev)
2284 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
2288 elsif Nkind (Prev) = N_Allocator
2289 or else Nkind (Prev) = N_Attribute_Reference
2293 -- Suppress null checks when passing to access parameters of Java
2294 -- and CIL subprograms. (Should this be done for other foreign
2295 -- conventions as well ???)
2297 elsif Convention (Subp) = Convention_Java
2298 or else Convention (Subp) = Convention_CIL
2303 Install_Null_Excluding_Check (Prev);
2307 -- Perform appropriate validity checks on parameters that
2310 if Validity_Checks_On then
2311 if (Ekind (Formal) = E_In_Parameter
2312 and then Validity_Check_In_Params)
2314 (Ekind (Formal) = E_In_Out_Parameter
2315 and then Validity_Check_In_Out_Params)
2317 -- If the actual is an indexed component of a packed type (or
2318 -- is an indexed or selected component whose prefix recursively
2319 -- meets this condition), it has not been expanded yet. It will
2320 -- be copied in the validity code that follows, and has to be
2321 -- expanded appropriately, so reanalyze it.
2323 -- What we do is just to unset analyzed bits on prefixes till
2324 -- we reach something that does not have a prefix.
2331 while Nkind (Nod) = N_Indexed_Component
2333 Nkind (Nod) = N_Selected_Component
2335 Set_Analyzed (Nod, False);
2336 Nod := Prefix (Nod);
2340 Ensure_Valid (Actual);
2344 -- For IN OUT and OUT parameters, ensure that subscripts are valid
2345 -- since this is a left side reference. We only do this for calls
2346 -- from the source program since we assume that compiler generated
2347 -- calls explicitly generate any required checks. We also need it
2348 -- only if we are doing standard validity checks, since clearly it
2349 -- is not needed if validity checks are off, and in subscript
2350 -- validity checking mode, all indexed components are checked with
2351 -- a call directly from Expand_N_Indexed_Component.
2353 if Comes_From_Source (N)
2354 and then Ekind (Formal) /= E_In_Parameter
2355 and then Validity_Checks_On
2356 and then Validity_Check_Default
2357 and then not Validity_Check_Subscripts
2359 Check_Valid_Lvalue_Subscripts (Actual);
2362 -- Mark any scalar OUT parameter that is a simple variable as no
2363 -- longer known to be valid (unless the type is always valid). This
2364 -- reflects the fact that if an OUT parameter is never set in a
2365 -- procedure, then it can become invalid on the procedure return.
2367 if Ekind (Formal) = E_Out_Parameter
2368 and then Is_Entity_Name (Actual)
2369 and then Ekind (Entity (Actual)) = E_Variable
2370 and then not Is_Known_Valid (Etype (Actual))
2372 Set_Is_Known_Valid (Entity (Actual), False);
2375 -- For an OUT or IN OUT parameter, if the actual is an entity, then
2376 -- clear current values, since they can be clobbered. We are probably
2377 -- doing this in more places than we need to, but better safe than
2378 -- sorry when it comes to retaining bad current values!
2380 if Ekind (Formal) /= E_In_Parameter
2381 and then Is_Entity_Name (Actual)
2383 Kill_Current_Values (Entity (Actual));
2386 -- If the formal is class wide and the actual is an aggregate, force
2387 -- evaluation so that the back end who does not know about class-wide
2388 -- type, does not generate a temporary of the wrong size.
2390 if not Is_Class_Wide_Type (Etype (Formal)) then
2393 elsif Nkind (Actual) = N_Aggregate
2394 or else (Nkind (Actual) = N_Qualified_Expression
2395 and then Nkind (Expression (Actual)) = N_Aggregate)
2397 Force_Evaluation (Actual);
2400 -- In a remote call, if the formal is of a class-wide type, check
2401 -- that the actual meets the requirements described in E.4(18).
2403 if Remote and then Is_Class_Wide_Type (Etype (Formal)) then
2404 Insert_Action (Actual,
2405 Make_Transportable_Check (Loc,
2406 Duplicate_Subexpr_Move_Checks (Actual)));
2409 -- This label is required when skipping extra actual generation for
2410 -- Unchecked_Union parameters.
2412 <<Skip_Extra_Actual_Generation>>
2414 Next_Actual (Actual);
2415 Next_Formal (Formal);
2418 -- If we are expanding a rhs of an assignment we need to check if tag
2419 -- propagation is needed. You might expect this processing to be in
2420 -- Analyze_Assignment but has to be done earlier (bottom-up) because the
2421 -- assignment might be transformed to a declaration for an unconstrained
2422 -- value if the expression is classwide.
2424 if Nkind (N) = N_Function_Call
2425 and then Is_Tag_Indeterminate (N)
2426 and then Is_Entity_Name (Name (N))
2429 Ass : Node_Id := Empty;
2432 if Nkind (Parent (N)) = N_Assignment_Statement then
2435 elsif Nkind (Parent (N)) = N_Qualified_Expression
2436 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
2438 Ass := Parent (Parent (N));
2440 elsif Nkind (Parent (N)) = N_Explicit_Dereference
2441 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
2443 Ass := Parent (Parent (N));
2447 and then Is_Class_Wide_Type (Etype (Name (Ass)))
2449 if Is_Access_Type (Etype (N)) then
2450 if Designated_Type (Etype (N)) /=
2451 Root_Type (Etype (Name (Ass)))
2454 ("tag-indeterminate expression "
2455 & " must have designated type& (RM 5.2 (6))",
2456 N, Root_Type (Etype (Name (Ass))));
2458 Propagate_Tag (Name (Ass), N);
2461 elsif Etype (N) /= Root_Type (Etype (Name (Ass))) then
2463 ("tag-indeterminate expression must have type&"
2464 & "(RM 5.2 (6))", N, Root_Type (Etype (Name (Ass))));
2467 Propagate_Tag (Name (Ass), N);
2470 -- The call will be rewritten as a dispatching call, and
2471 -- expanded as such.
2478 -- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
2479 -- it to point to the correct secondary virtual table
2481 if (Nkind (N) = N_Function_Call
2482 or else Nkind (N) = N_Procedure_Call_Statement)
2483 and then CW_Interface_Formals_Present
2485 Expand_Interface_Actuals (N);
2488 -- Deals with Dispatch_Call if we still have a call, before expanding
2489 -- extra actuals since this will be done on the re-analysis of the
2490 -- dispatching call. Note that we do not try to shorten the actual
2491 -- list for a dispatching call, it would not make sense to do so.
2492 -- Expansion of dispatching calls is suppressed when VM_Target, because
2493 -- the VM back-ends directly handle the generation of dispatching
2494 -- calls and would have to undo any expansion to an indirect call.
2496 if (Nkind (N) = N_Function_Call
2497 or else Nkind (N) = N_Procedure_Call_Statement)
2498 and then Present (Controlling_Argument (N))
2499 and then VM_Target = No_VM
2501 Expand_Dispatching_Call (N);
2503 -- The following return is worrisome. Is it really OK to
2504 -- skip all remaining processing in this procedure ???
2508 -- Similarly, expand calls to RCI subprograms on which pragma
2509 -- All_Calls_Remote applies. The rewriting will be reanalyzed
2510 -- later. Do this only when the call comes from source since we do
2511 -- not want such a rewritting to occur in expanded code.
2513 elsif Is_All_Remote_Call (N) then
2514 Expand_All_Calls_Remote_Subprogram_Call (N);
2516 -- Similarly, do not add extra actuals for an entry call whose entity
2517 -- is a protected procedure, or for an internal protected subprogram
2518 -- call, because it will be rewritten as a protected subprogram call
2519 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
2521 elsif Is_Protected_Type (Scope (Subp))
2522 and then (Ekind (Subp) = E_Procedure
2523 or else Ekind (Subp) = E_Function)
2527 -- During that loop we gathered the extra actuals (the ones that
2528 -- correspond to Extra_Formals), so now they can be appended.
2531 while Is_Non_Empty_List (Extra_Actuals) loop
2532 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
2536 -- At this point we have all the actuals, so this is the point at
2537 -- which the various expansion activities for actuals is carried out.
2539 Expand_Actuals (N, Subp);
2541 -- If the subprogram is a renaming, or if it is inherited, replace it
2542 -- in the call with the name of the actual subprogram being called.
2543 -- If this is a dispatching call, the run-time decides what to call.
2544 -- The Alias attribute does not apply to entries.
2546 if Nkind (N) /= N_Entry_Call_Statement
2547 and then No (Controlling_Argument (N))
2548 and then Present (Parent_Subp)
2550 if Present (Inherited_From_Formal (Subp)) then
2551 Parent_Subp := Inherited_From_Formal (Subp);
2553 while Present (Alias (Parent_Subp)) loop
2554 Parent_Subp := Alias (Parent_Subp);
2558 -- The below setting of Entity is suspect, see F109-018 discussion???
2560 Set_Entity (Name (N), Parent_Subp);
2562 if Is_Abstract_Subprogram (Parent_Subp)
2563 and then not In_Instance
2566 ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
2569 -- Add an explicit conversion for parameter of the derived type.
2570 -- This is only done for scalar and access in-parameters. Others
2571 -- have been expanded in expand_actuals.
2573 Formal := First_Formal (Subp);
2574 Parent_Formal := First_Formal (Parent_Subp);
2575 Actual := First_Actual (N);
2577 -- It is not clear that conversion is needed for intrinsic
2578 -- subprograms, but it certainly is for those that are user-
2579 -- defined, and that can be inherited on derivation, namely
2580 -- unchecked conversion and deallocation.
2581 -- General case needs study ???
2583 if not Is_Intrinsic_Subprogram (Parent_Subp)
2584 or else Is_Generic_Instance (Parent_Subp)
2586 while Present (Formal) loop
2587 if Etype (Formal) /= Etype (Parent_Formal)
2588 and then Is_Scalar_Type (Etype (Formal))
2589 and then Ekind (Formal) = E_In_Parameter
2591 not Subtypes_Statically_Match
2592 (Etype (Parent_Formal), Etype (Actual))
2593 and then not Raises_Constraint_Error (Actual)
2596 OK_Convert_To (Etype (Parent_Formal),
2597 Relocate_Node (Actual)));
2600 Resolve (Actual, Etype (Parent_Formal));
2601 Enable_Range_Check (Actual);
2603 elsif Is_Access_Type (Etype (Formal))
2604 and then Base_Type (Etype (Parent_Formal)) /=
2605 Base_Type (Etype (Actual))
2607 if Ekind (Formal) /= E_In_Parameter then
2609 Convert_To (Etype (Parent_Formal),
2610 Relocate_Node (Actual)));
2613 Resolve (Actual, Etype (Parent_Formal));
2616 Ekind (Etype (Parent_Formal)) = E_Anonymous_Access_Type
2617 and then Designated_Type (Etype (Parent_Formal))
2619 Designated_Type (Etype (Actual))
2620 and then not Is_Controlling_Formal (Formal)
2622 -- This unchecked conversion is not necessary unless
2623 -- inlining is enabled, because in that case the type
2624 -- mismatch may become visible in the body about to be
2628 Unchecked_Convert_To (Etype (Parent_Formal),
2629 Relocate_Node (Actual)));
2632 Resolve (Actual, Etype (Parent_Formal));
2636 Next_Formal (Formal);
2637 Next_Formal (Parent_Formal);
2638 Next_Actual (Actual);
2643 Subp := Parent_Subp;
2646 -- Check for violation of No_Abort_Statements
2648 if Is_RTE (Subp, RE_Abort_Task) then
2649 Check_Restriction (No_Abort_Statements, N);
2651 -- Check for violation of No_Dynamic_Attachment
2653 elsif RTU_Loaded (Ada_Interrupts)
2654 and then (Is_RTE (Subp, RE_Is_Reserved) or else
2655 Is_RTE (Subp, RE_Is_Attached) or else
2656 Is_RTE (Subp, RE_Current_Handler) or else
2657 Is_RTE (Subp, RE_Attach_Handler) or else
2658 Is_RTE (Subp, RE_Exchange_Handler) or else
2659 Is_RTE (Subp, RE_Detach_Handler) or else
2660 Is_RTE (Subp, RE_Reference))
2662 Check_Restriction (No_Dynamic_Attachment, N);
2665 -- Deal with case where call is an explicit dereference
2667 if Nkind (Name (N)) = N_Explicit_Dereference then
2669 -- Handle case of access to protected subprogram type
2671 if Is_Access_Protected_Subprogram_Type
2672 (Base_Type (Etype (Prefix (Name (N)))))
2674 -- If this is a call through an access to protected operation,
2675 -- the prefix has the form (object'address, operation'access).
2676 -- Rewrite as a for other protected calls: the object is the
2677 -- first parameter of the list of actuals.
2684 Ptr : constant Node_Id := Prefix (Name (N));
2686 T : constant Entity_Id :=
2687 Equivalent_Type (Base_Type (Etype (Ptr)));
2689 D_T : constant Entity_Id :=
2690 Designated_Type (Base_Type (Etype (Ptr)));
2694 Make_Selected_Component (Loc,
2695 Prefix => Unchecked_Convert_To (T, Ptr),
2697 New_Occurrence_Of (First_Entity (T), Loc));
2700 Make_Selected_Component (Loc,
2701 Prefix => Unchecked_Convert_To (T, Ptr),
2703 New_Occurrence_Of (Next_Entity (First_Entity (T)), Loc));
2706 Make_Explicit_Dereference (Loc,
2709 if Present (Parameter_Associations (N)) then
2710 Parm := Parameter_Associations (N);
2715 Prepend (Obj, Parm);
2717 if Etype (D_T) = Standard_Void_Type then
2719 Make_Procedure_Call_Statement (Loc,
2721 Parameter_Associations => Parm);
2724 Make_Function_Call (Loc,
2726 Parameter_Associations => Parm);
2729 Set_First_Named_Actual (Call, First_Named_Actual (N));
2730 Set_Etype (Call, Etype (D_T));
2732 -- We do not re-analyze the call to avoid infinite recursion.
2733 -- We analyze separately the prefix and the object, and set
2734 -- the checks on the prefix that would otherwise be emitted
2735 -- when resolving a call.
2739 Apply_Access_Check (Nam);
2746 -- If this is a call to an intrinsic subprogram, then perform the
2747 -- appropriate expansion to the corresponding tree node and we
2748 -- are all done (since after that the call is gone!)
2750 -- In the case where the intrinsic is to be processed by the back end,
2751 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
2752 -- since the idea in this case is to pass the call unchanged.
2753 -- If the intrinsic is an inherited unchecked conversion, and the
2754 -- derived type is the target type of the conversion, we must retain
2755 -- it as the return type of the expression. Otherwise the expansion
2756 -- below, which uses the parent operation, will yield the wrong type.
2758 if Is_Intrinsic_Subprogram (Subp) then
2759 Expand_Intrinsic_Call (N, Subp);
2761 if Nkind (N) = N_Unchecked_Type_Conversion
2762 and then Parent_Subp /= Orig_Subp
2763 and then Etype (Parent_Subp) /= Etype (Orig_Subp)
2765 Set_Etype (N, Etype (Orig_Subp));
2771 if Ekind (Subp) = E_Function
2772 or else Ekind (Subp) = E_Procedure
2774 if Is_Inlined (Subp) then
2776 Inlined_Subprogram : declare
2778 Must_Inline : Boolean := False;
2779 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
2780 Scop : constant Entity_Id := Scope (Subp);
2782 function In_Unfrozen_Instance return Boolean;
2783 -- If the subprogram comes from an instance in the same
2784 -- unit, and the instance is not yet frozen, inlining might
2785 -- trigger order-of-elaboration problems in gigi.
2787 --------------------------
2788 -- In_Unfrozen_Instance --
2789 --------------------------
2791 function In_Unfrozen_Instance return Boolean is
2797 and then S /= Standard_Standard
2799 if Is_Generic_Instance (S)
2800 and then Present (Freeze_Node (S))
2801 and then not Analyzed (Freeze_Node (S))
2810 end In_Unfrozen_Instance;
2812 -- Start of processing for Inlined_Subprogram
2815 -- Verify that the body to inline has already been seen, and
2816 -- that if the body is in the current unit the inlining does
2817 -- not occur earlier. This avoids order-of-elaboration problems
2820 -- This should be documented in sinfo/einfo ???
2823 or else Nkind (Spec) /= N_Subprogram_Declaration
2824 or else No (Body_To_Inline (Spec))
2826 Must_Inline := False;
2828 -- If this an inherited function that returns a private
2829 -- type, do not inline if the full view is an unconstrained
2830 -- array, because such calls cannot be inlined.
2832 elsif Present (Orig_Subp)
2833 and then Is_Array_Type (Etype (Orig_Subp))
2834 and then not Is_Constrained (Etype (Orig_Subp))
2836 Must_Inline := False;
2838 elsif In_Unfrozen_Instance then
2839 Must_Inline := False;
2842 Bod := Body_To_Inline (Spec);
2844 if (In_Extended_Main_Code_Unit (N)
2845 or else In_Extended_Main_Code_Unit (Parent (N))
2846 or else Is_Always_Inlined (Subp))
2847 and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
2849 Earlier_In_Extended_Unit (Sloc (Bod), Loc))
2851 Must_Inline := True;
2853 -- If we are compiling a package body that is not the main
2854 -- unit, it must be for inlining/instantiation purposes,
2855 -- in which case we inline the call to insure that the same
2856 -- temporaries are generated when compiling the body by
2857 -- itself. Otherwise link errors can occur.
2859 -- If the function being called is itself in the main unit,
2860 -- we cannot inline, because there is a risk of double
2861 -- elaboration and/or circularity: the inlining can make
2862 -- visible a private entity in the body of the main unit,
2863 -- that gigi will see before its sees its proper definition.
2865 elsif not (In_Extended_Main_Code_Unit (N))
2866 and then In_Package_Body
2868 Must_Inline := not In_Extended_Main_Source_Unit (Subp);
2873 Expand_Inlined_Call (N, Subp, Orig_Subp);
2876 -- Let the back end handle it
2878 Add_Inlined_Body (Subp);
2880 if Front_End_Inlining
2881 and then Nkind (Spec) = N_Subprogram_Declaration
2882 and then (In_Extended_Main_Code_Unit (N))
2883 and then No (Body_To_Inline (Spec))
2884 and then not Has_Completion (Subp)
2885 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
2888 ("cannot inline& (body not seen yet)?",
2892 end Inlined_Subprogram;
2896 -- Check for a protected subprogram. This is either an intra-object
2897 -- call, or a protected function call. Protected procedure calls are
2898 -- rewritten as entry calls and handled accordingly.
2900 -- In Ada 2005, this may be an indirect call to an access parameter
2901 -- that is an access_to_subprogram. In that case the anonymous type
2902 -- has a scope that is a protected operation, but the call is a
2905 Scop := Scope (Subp);
2907 if Nkind (N) /= N_Entry_Call_Statement
2908 and then Is_Protected_Type (Scop)
2909 and then Ekind (Subp) /= E_Subprogram_Type
2911 -- If the call is an internal one, it is rewritten as a call to
2912 -- to the corresponding unprotected subprogram.
2914 Expand_Protected_Subprogram_Call (N, Subp, Scop);
2917 -- Functions returning controlled objects need special attention
2918 -- If the return type is limited the context is an initialization
2919 -- and different processing applies.
2921 if Controlled_Type (Etype (Subp))
2922 and then not Is_Inherently_Limited_Type (Etype (Subp))
2923 and then not Is_Limited_Interface (Etype (Subp))
2925 Expand_Ctrl_Function_Call (N);
2928 -- Test for First_Optional_Parameter, and if so, truncate parameter
2929 -- list if there are optional parameters at the trailing end.
2930 -- Note we never delete procedures for call via a pointer.
2932 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
2933 and then Present (First_Optional_Parameter (Subp))
2936 Last_Keep_Arg : Node_Id;
2939 -- Last_Keep_Arg will hold the last actual that should be
2940 -- retained. If it remains empty at the end, it means that
2941 -- all parameters are optional.
2943 Last_Keep_Arg := Empty;
2945 -- Find first optional parameter, must be present since we
2946 -- checked the validity of the parameter before setting it.
2948 Formal := First_Formal (Subp);
2949 Actual := First_Actual (N);
2950 while Formal /= First_Optional_Parameter (Subp) loop
2951 Last_Keep_Arg := Actual;
2952 Next_Formal (Formal);
2953 Next_Actual (Actual);
2956 -- We have Formal and Actual pointing to the first potentially
2957 -- droppable argument. We can drop all the trailing arguments
2958 -- whose actual matches the default. Note that we know that all
2959 -- remaining formals have defaults, because we checked that this
2960 -- requirement was met before setting First_Optional_Parameter.
2962 -- We use Fully_Conformant_Expressions to check for identity
2963 -- between formals and actuals, which may miss some cases, but
2964 -- on the other hand, this is only an optimization (if we fail
2965 -- to truncate a parameter it does not affect functionality).
2966 -- So if the default is 3 and the actual is 1+2, we consider
2967 -- them unequal, which hardly seems worrisome.
2969 while Present (Formal) loop
2970 if not Fully_Conformant_Expressions
2971 (Actual, Default_Value (Formal))
2973 Last_Keep_Arg := Actual;
2976 Next_Formal (Formal);
2977 Next_Actual (Actual);
2980 -- If no arguments, delete entire list, this is the easy case
2982 if No (Last_Keep_Arg) then
2983 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2984 Delete_Tree (Remove_Head (Parameter_Associations (N)));
2987 Set_Parameter_Associations (N, No_List);
2988 Set_First_Named_Actual (N, Empty);
2990 -- Case where at the last retained argument is positional. This
2991 -- is also an easy case, since the retained arguments are already
2992 -- in the right form, and we don't need to worry about the order
2993 -- of arguments that get eliminated.
2995 elsif Is_List_Member (Last_Keep_Arg) then
2996 while Present (Next (Last_Keep_Arg)) loop
2997 Delete_Tree (Remove_Next (Last_Keep_Arg));
3000 Set_First_Named_Actual (N, Empty);
3002 -- This is the annoying case where the last retained argument
3003 -- is a named parameter. Since the original arguments are not
3004 -- in declaration order, we may have to delete some fairly
3005 -- random collection of arguments.
3013 -- First step, remove all the named parameters from the
3014 -- list (they are still chained using First_Named_Actual
3015 -- and Next_Named_Actual, so we have not lost them!)
3017 Temp := First (Parameter_Associations (N));
3019 -- Case of all parameters named, remove them all
3021 if Nkind (Temp) = N_Parameter_Association then
3022 while Is_Non_Empty_List (Parameter_Associations (N)) loop
3023 Temp := Remove_Head (Parameter_Associations (N));
3026 -- Case of mixed positional/named, remove named parameters
3029 while Nkind (Next (Temp)) /= N_Parameter_Association loop
3033 while Present (Next (Temp)) loop
3034 Remove (Next (Temp));
3038 -- Now we loop through the named parameters, till we get
3039 -- to the last one to be retained, adding them to the list.
3040 -- Note that the Next_Named_Actual list does not need to be
3041 -- touched since we are only reordering them on the actual
3042 -- parameter association list.
3044 Passoc := Parent (First_Named_Actual (N));
3046 Temp := Relocate_Node (Passoc);
3048 (Parameter_Associations (N), Temp);
3050 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
3051 Passoc := Parent (Next_Named_Actual (Passoc));
3054 Set_Next_Named_Actual (Temp, Empty);
3057 Temp := Next_Named_Actual (Passoc);
3058 exit when No (Temp);
3059 Set_Next_Named_Actual
3060 (Passoc, Next_Named_Actual (Parent (Temp)));
3068 -- Special processing for Ada 2005 AI-329, which requires a call to
3069 -- Raise_Exception to raise Constraint_Error if the Exception_Id is
3070 -- null. Note that we never need to do this in GNAT mode, or if the
3071 -- parameter to Raise_Exception is a use of Identity, since in these
3072 -- cases we know that the parameter is never null.
3074 -- Note: We must check that the node has not been inlined. This is
3075 -- required because under zfp the Raise_Exception subprogram has the
3076 -- pragma inline_always (and hence the call has been expanded above
3077 -- into a block containing the code of the subprogram).
3079 if Ada_Version >= Ada_05
3080 and then not GNAT_Mode
3081 and then Is_RTE (Subp, RE_Raise_Exception)
3082 and then Nkind (N) = N_Procedure_Call_Statement
3083 and then (Nkind (First_Actual (N)) /= N_Attribute_Reference
3084 or else Attribute_Name (First_Actual (N)) /= Name_Identity)
3087 RCE : constant Node_Id :=
3088 Make_Raise_Constraint_Error (Loc,
3089 Reason => CE_Null_Exception_Id);
3091 Insert_After (N, RCE);
3097 --------------------------
3098 -- Expand_Inlined_Call --
3099 --------------------------
3101 procedure Expand_Inlined_Call
3104 Orig_Subp : Entity_Id)
3106 Loc : constant Source_Ptr := Sloc (N);
3107 Is_Predef : constant Boolean :=
3108 Is_Predefined_File_Name
3109 (Unit_File_Name (Get_Source_Unit (Subp)));
3110 Orig_Bod : constant Node_Id :=
3111 Body_To_Inline (Unit_Declaration_Node (Subp));
3116 Decls : constant List_Id := New_List;
3117 Exit_Lab : Entity_Id := Empty;
3124 Ret_Type : Entity_Id;
3128 Temp_Typ : Entity_Id;
3130 Is_Unc : constant Boolean :=
3131 Is_Array_Type (Etype (Subp))
3132 and then not Is_Constrained (Etype (Subp));
3133 -- If the type returned by the function is unconstrained and the
3134 -- call can be inlined, special processing is required.
3136 function Is_Null_Procedure return Boolean;
3137 -- Predicate to recognize stubbed procedures and null procedures, for
3138 -- which there is no need for the full inlining mechanism.
3140 procedure Make_Exit_Label;
3141 -- Build declaration for exit label to be used in Return statements
3143 function Process_Formals (N : Node_Id) return Traverse_Result;
3144 -- Replace occurrence of a formal with the corresponding actual, or
3145 -- the thunk generated for it.
3147 function Process_Sloc (Nod : Node_Id) return Traverse_Result;
3148 -- If the call being expanded is that of an internal subprogram,
3149 -- set the sloc of the generated block to that of the call itself,
3150 -- so that the expansion is skipped by the -next- command in gdb.
3151 -- Same processing for a subprogram in a predefined file, e.g.
3152 -- Ada.Tags. If Debug_Generated_Code is true, suppress this change
3153 -- to simplify our own development.
3155 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
3156 -- If the function body is a single expression, replace call with
3157 -- expression, else insert block appropriately.
3159 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
3160 -- If procedure body has no local variables, inline body without
3161 -- creating block, otherwise rewrite call with block.
3163 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean;
3164 -- Determine whether a formal parameter is used only once in Orig_Bod
3166 -----------------------
3167 -- Is_Null_Procedure --
3168 -----------------------
3170 function Is_Null_Procedure return Boolean is
3171 Decl : constant Node_Id := Unit_Declaration_Node (Subp);
3174 if Ekind (Subp) /= E_Procedure then
3177 elsif Nkind (Orig_Bod) /= N_Subprogram_Body then
3180 -- Check if this is an Ada 2005 null procedure
3182 elsif Nkind (Decl) = N_Subprogram_Declaration
3183 and then Null_Present (Specification (Decl))
3187 -- Check if the body contains only a null statement, followed by the
3188 -- return statement added during expansion.
3192 Stat : constant Node_Id :=
3194 (Statements (Handled_Statement_Sequence (Orig_Bod)));
3196 Stat2 : constant Node_Id := Next (Stat);
3200 Nkind (Stat) = N_Null_Statement
3204 (Nkind (Stat2) = N_Simple_Return_Statement
3205 and then No (Next (Stat2))));
3208 end Is_Null_Procedure;
3210 ---------------------
3211 -- Make_Exit_Label --
3212 ---------------------
3214 procedure Make_Exit_Label is
3216 -- Create exit label for subprogram if one does not exist yet
3218 if No (Exit_Lab) then
3220 Make_Identifier (Loc,
3221 Chars => New_Internal_Name ('L'));
3223 Make_Defining_Identifier (Loc, Chars (Lab_Id)));
3224 Exit_Lab := Make_Label (Loc, Lab_Id);
3227 Make_Implicit_Label_Declaration (Loc,
3228 Defining_Identifier => Entity (Lab_Id),
3229 Label_Construct => Exit_Lab);
3231 end Make_Exit_Label;
3233 ---------------------
3234 -- Process_Formals --
3235 ---------------------
3237 function Process_Formals (N : Node_Id) return Traverse_Result is
3243 if Is_Entity_Name (N)
3244 and then Present (Entity (N))
3249 and then Scope (E) = Subp
3251 A := Renamed_Object (E);
3253 -- Rewrite the occurrence of the formal into an occurrence of
3254 -- the actual. Also establish visibility on the proper view of
3255 -- the actual's subtype for the body's context (if the actual's
3256 -- subtype is private at the call point but its full view is
3257 -- visible to the body, then the inlined tree here must be
3258 -- analyzed with the full view).
3260 if Is_Entity_Name (A) then
3261 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
3262 Check_Private_View (N);
3264 elsif Nkind (A) = N_Defining_Identifier then
3265 Rewrite (N, New_Occurrence_Of (A, Loc));
3266 Check_Private_View (N);
3271 Rewrite (N, New_Copy (A));
3277 elsif Nkind (N) = N_Simple_Return_Statement then
3278 if No (Expression (N)) then
3281 Make_Goto_Statement (Loc,
3282 Name => New_Copy (Lab_Id)));
3285 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
3286 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
3288 -- Function body is a single expression. No need for
3294 Num_Ret := Num_Ret + 1;
3298 -- Because of the presence of private types, the views of the
3299 -- expression and the context may be different, so place an
3300 -- unchecked conversion to the context type to avoid spurious
3301 -- errors, eg. when the expression is a numeric literal and
3302 -- the context is private. If the expression is an aggregate,
3303 -- use a qualified expression, because an aggregate is not a
3304 -- legal argument of a conversion.
3306 if Nkind (Expression (N)) = N_Aggregate
3307 or else Nkind (Expression (N)) = N_Null
3310 Make_Qualified_Expression (Sloc (N),
3311 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
3312 Expression => Relocate_Node (Expression (N)));
3315 Unchecked_Convert_To
3316 (Ret_Type, Relocate_Node (Expression (N)));
3319 if Nkind (Targ) = N_Defining_Identifier then
3321 Make_Assignment_Statement (Loc,
3322 Name => New_Occurrence_Of (Targ, Loc),
3323 Expression => Ret));
3326 Make_Assignment_Statement (Loc,
3327 Name => New_Copy (Targ),
3328 Expression => Ret));
3331 Set_Assignment_OK (Name (N));
3333 if Present (Exit_Lab) then
3335 Make_Goto_Statement (Loc,
3336 Name => New_Copy (Lab_Id)));
3342 -- Remove pragma Unreferenced since it may refer to formals that
3343 -- are not visible in the inlined body, and in any case we will
3344 -- not be posting warnings on the inlined body so it is unneeded.
3346 elsif Nkind (N) = N_Pragma
3347 and then Chars (N) = Name_Unreferenced
3349 Rewrite (N, Make_Null_Statement (Sloc (N)));
3355 end Process_Formals;
3357 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
3363 function Process_Sloc (Nod : Node_Id) return Traverse_Result is
3365 if not Debug_Generated_Code then
3366 Set_Sloc (Nod, Sloc (N));
3367 Set_Comes_From_Source (Nod, False);
3373 procedure Reset_Slocs is new Traverse_Proc (Process_Sloc);
3375 ---------------------------
3376 -- Rewrite_Function_Call --
3377 ---------------------------
3379 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
3380 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
3381 Fst : constant Node_Id := First (Statements (HSS));
3384 -- Optimize simple case: function body is a single return statement,
3385 -- which has been expanded into an assignment.
3387 if Is_Empty_List (Declarations (Blk))
3388 and then Nkind (Fst) = N_Assignment_Statement
3389 and then No (Next (Fst))
3392 -- The function call may have been rewritten as the temporary
3393 -- that holds the result of the call, in which case remove the
3394 -- now useless declaration.
3396 if Nkind (N) = N_Identifier
3397 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
3399 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
3402 Rewrite (N, Expression (Fst));
3404 elsif Nkind (N) = N_Identifier
3405 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
3407 -- The block assigns the result of the call to the temporary
3409 Insert_After (Parent (Entity (N)), Blk);
3411 elsif Nkind (Parent (N)) = N_Assignment_Statement
3413 (Is_Entity_Name (Name (Parent (N)))
3415 (Nkind (Name (Parent (N))) = N_Explicit_Dereference
3416 and then Is_Entity_Name (Prefix (Name (Parent (N))))))
3418 -- Replace assignment with the block
3421 Original_Assignment : constant Node_Id := Parent (N);
3424 -- Preserve the original assignment node to keep the complete
3425 -- assignment subtree consistent enough for Analyze_Assignment
3426 -- to proceed (specifically, the original Lhs node must still
3427 -- have an assignment statement as its parent).
3429 -- We cannot rely on Original_Node to go back from the block
3430 -- node to the assignment node, because the assignment might
3431 -- already be a rewrite substitution.
3433 Discard_Node (Relocate_Node (Original_Assignment));
3434 Rewrite (Original_Assignment, Blk);
3437 elsif Nkind (Parent (N)) = N_Object_Declaration then
3438 Set_Expression (Parent (N), Empty);
3439 Insert_After (Parent (N), Blk);
3442 Insert_Before (Parent (N), Blk);
3444 end Rewrite_Function_Call;
3446 ----------------------------
3447 -- Rewrite_Procedure_Call --
3448 ----------------------------
3450 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
3451 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
3453 -- If there is a transient scope for N, this will be the scope of the
3454 -- actions for N, and the statements in Blk need to be within this
3455 -- scope. For example, they need to have visibility on the constant
3456 -- declarations created for the formals.
3458 -- If N needs no transient scope, and if there are no declarations in
3459 -- the inlined body, we can do a little optimization and insert the
3460 -- statements for the body directly after N, and rewrite N to a
3461 -- null statement, instead of rewriting N into a full-blown block
3464 if not Scope_Is_Transient
3465 and then Is_Empty_List (Declarations (Blk))
3467 Insert_List_After (N, Statements (HSS));
3468 Rewrite (N, Make_Null_Statement (Loc));
3472 end Rewrite_Procedure_Call;
3474 -------------------------
3475 -- Formal_Is_Used_Once --
3476 -------------------------
3478 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean is
3479 Use_Counter : Int := 0;
3481 function Count_Uses (N : Node_Id) return Traverse_Result;
3482 -- Traverse the tree and count the uses of the formal parameter.
3483 -- In this case, for optimization purposes, we do not need to
3484 -- continue the traversal once more than one use is encountered.
3490 function Count_Uses (N : Node_Id) return Traverse_Result is
3492 -- The original node is an identifier
3494 if Nkind (N) = N_Identifier
3495 and then Present (Entity (N))
3497 -- Original node's entity points to the one in the copied body
3499 and then Nkind (Entity (N)) = N_Identifier
3500 and then Present (Entity (Entity (N)))
3502 -- The entity of the copied node is the formal parameter
3504 and then Entity (Entity (N)) = Formal
3506 Use_Counter := Use_Counter + 1;
3508 if Use_Counter > 1 then
3510 -- Denote more than one use and abandon the traversal
3521 procedure Count_Formal_Uses is new Traverse_Proc (Count_Uses);
3523 -- Start of processing for Formal_Is_Used_Once
3526 Count_Formal_Uses (Orig_Bod);
3527 return Use_Counter = 1;
3528 end Formal_Is_Used_Once;
3530 -- Start of processing for Expand_Inlined_Call
3533 -- Check for special case of To_Address call, and if so, just do an
3534 -- unchecked conversion instead of expanding the call. Not only is this
3535 -- more efficient, but it also avoids problem with order of elaboration
3536 -- when address clauses are inlined (address expression elaborated at
3539 if Subp = RTE (RE_To_Address) then
3541 Unchecked_Convert_To
3543 Relocate_Node (First_Actual (N))));
3546 elsif Is_Null_Procedure then
3547 Rewrite (N, Make_Null_Statement (Loc));
3551 -- Check for an illegal attempt to inline a recursive procedure. If the
3552 -- subprogram has parameters this is detected when trying to supply a
3553 -- binding for parameters that already have one. For parameterless
3554 -- subprograms this must be done explicitly.
3556 if In_Open_Scopes (Subp) then
3557 Error_Msg_N ("call to recursive subprogram cannot be inlined?", N);
3558 Set_Is_Inlined (Subp, False);
3562 if Nkind (Orig_Bod) = N_Defining_Identifier
3563 or else Nkind (Orig_Bod) = N_Defining_Operator_Symbol
3565 -- Subprogram is a renaming_as_body. Calls appearing after the
3566 -- renaming can be replaced with calls to the renamed entity
3567 -- directly, because the subprograms are subtype conformant. If
3568 -- the renamed subprogram is an inherited operation, we must redo
3569 -- the expansion because implicit conversions may be needed.
3571 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
3573 if Present (Alias (Orig_Bod)) then
3580 -- Use generic machinery to copy body of inlined subprogram, as if it
3581 -- were an instantiation, resetting source locations appropriately, so
3582 -- that nested inlined calls appear in the main unit.
3584 Save_Env (Subp, Empty);
3585 Set_Copied_Sloc_For_Inlined_Body (N, Defining_Entity (Orig_Bod));
3587 Bod := Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
3589 Make_Block_Statement (Loc,
3590 Declarations => Declarations (Bod),
3591 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
3593 if No (Declarations (Bod)) then
3594 Set_Declarations (Blk, New_List);
3597 -- For the unconstrained case, capture the name of the local
3598 -- variable that holds the result. This must be the first declaration
3599 -- in the block, because its bounds cannot depend on local variables.
3600 -- Otherwise there is no way to declare the result outside of the
3601 -- block. Needless to say, in general the bounds will depend on the
3602 -- actuals in the call.
3605 Targ1 := Defining_Identifier (First (Declarations (Blk)));
3608 -- If this is a derived function, establish the proper return type
3610 if Present (Orig_Subp)
3611 and then Orig_Subp /= Subp
3613 Ret_Type := Etype (Orig_Subp);
3615 Ret_Type := Etype (Subp);
3618 -- Create temporaries for the actuals that are expressions, or that
3619 -- are scalars and require copying to preserve semantics.
3621 F := First_Formal (Subp);
3622 A := First_Actual (N);
3623 while Present (F) loop
3624 if Present (Renamed_Object (F)) then
3625 Error_Msg_N ("cannot inline call to recursive subprogram", N);
3629 -- If the argument may be a controlling argument in a call within
3630 -- the inlined body, we must preserve its classwide nature to insure
3631 -- that dynamic dispatching take place subsequently. If the formal
3632 -- has a constraint it must be preserved to retain the semantics of
3635 if Is_Class_Wide_Type (Etype (F))
3636 or else (Is_Access_Type (Etype (F))
3638 Is_Class_Wide_Type (Designated_Type (Etype (F))))
3640 Temp_Typ := Etype (F);
3642 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
3643 and then Etype (F) /= Base_Type (Etype (F))
3645 Temp_Typ := Etype (F);
3648 Temp_Typ := Etype (A);
3651 -- If the actual is a simple name or a literal, no need to
3652 -- create a temporary, object can be used directly.
3654 -- If the actual is a literal and the formal has its address taken,
3655 -- we cannot pass the literal itself as an argument, so its value
3656 -- must be captured in a temporary.
3658 if (Is_Entity_Name (A)
3660 (not Is_Scalar_Type (Etype (A))
3661 or else Ekind (Entity (A)) = E_Enumeration_Literal))
3663 -- When the actual is an identifier and the corresponding formal
3664 -- is used only once in the original body, the formal can be
3665 -- substituted directly with the actual parameter.
3667 or else (Nkind (A) = N_Identifier
3668 and then Formal_Is_Used_Once (F))
3671 ((Nkind (A) = N_Real_Literal or else
3672 Nkind (A) = N_Integer_Literal or else
3673 Nkind (A) = N_Character_Literal)
3674 and then not Address_Taken (F))
3676 if Etype (F) /= Etype (A) then
3678 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
3680 Set_Renamed_Object (F, A);
3685 Make_Defining_Identifier (Loc,
3686 Chars => New_Internal_Name ('C'));
3688 -- If the actual for an in/in-out parameter is a view conversion,
3689 -- make it into an unchecked conversion, given that an untagged
3690 -- type conversion is not a proper object for a renaming.
3692 -- In-out conversions that involve real conversions have already
3693 -- been transformed in Expand_Actuals.
3695 if Nkind (A) = N_Type_Conversion
3696 and then Ekind (F) /= E_In_Parameter
3699 Make_Unchecked_Type_Conversion (Loc,
3700 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
3701 Expression => Relocate_Node (Expression (A)));
3703 elsif Etype (F) /= Etype (A) then
3704 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
3705 Temp_Typ := Etype (F);
3708 New_A := Relocate_Node (A);
3711 Set_Sloc (New_A, Sloc (N));
3713 -- If the actual has a by-reference type, it cannot be copied, so
3714 -- its value is captured in a renaming declaration. Otherwise
3715 -- declare a local constant initialized with the actual.
3717 if Ekind (F) = E_In_Parameter
3718 and then not Is_Limited_Type (Etype (A))
3719 and then not Is_Tagged_Type (Etype (A))
3722 Make_Object_Declaration (Loc,
3723 Defining_Identifier => Temp,
3724 Constant_Present => True,
3725 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
3726 Expression => New_A);
3729 Make_Object_Renaming_Declaration (Loc,
3730 Defining_Identifier => Temp,
3731 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
3735 Append (Decl, Decls);
3736 Set_Renamed_Object (F, Temp);
3743 -- Establish target of function call. If context is not assignment or
3744 -- declaration, create a temporary as a target. The declaration for
3745 -- the temporary may be subsequently optimized away if the body is a
3746 -- single expression, or if the left-hand side of the assignment is
3747 -- simple enough, i.e. an entity or an explicit dereference of one.
3749 if Ekind (Subp) = E_Function then
3750 if Nkind (Parent (N)) = N_Assignment_Statement
3751 and then Is_Entity_Name (Name (Parent (N)))
3753 Targ := Name (Parent (N));
3755 elsif Nkind (Parent (N)) = N_Assignment_Statement
3756 and then Nkind (Name (Parent (N))) = N_Explicit_Dereference
3757 and then Is_Entity_Name (Prefix (Name (Parent (N))))
3759 Targ := Name (Parent (N));
3762 -- Replace call with temporary and create its declaration
3765 Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
3766 Set_Is_Internal (Temp);
3768 -- For the unconstrained case. the generated temporary has the
3769 -- same constrained declaration as the result variable.
3770 -- It may eventually be possible to remove that temporary and
3771 -- use the result variable directly.
3775 Make_Object_Declaration (Loc,
3776 Defining_Identifier => Temp,
3777 Object_Definition =>
3778 New_Copy_Tree (Object_Definition (Parent (Targ1))));
3780 Replace_Formals (Decl);
3784 Make_Object_Declaration (Loc,
3785 Defining_Identifier => Temp,
3786 Object_Definition =>
3787 New_Occurrence_Of (Ret_Type, Loc));
3789 Set_Etype (Temp, Ret_Type);
3792 Set_No_Initialization (Decl);
3793 Append (Decl, Decls);
3794 Rewrite (N, New_Occurrence_Of (Temp, Loc));
3799 Insert_Actions (N, Decls);
3801 -- Traverse the tree and replace formals with actuals or their thunks.
3802 -- Attach block to tree before analysis and rewriting.
3804 Replace_Formals (Blk);
3805 Set_Parent (Blk, N);
3807 if not Comes_From_Source (Subp)
3813 if Present (Exit_Lab) then
3815 -- If the body was a single expression, the single return statement
3816 -- and the corresponding label are useless.
3820 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
3823 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
3825 Append (Lab_Decl, (Declarations (Blk)));
3826 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
3830 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
3831 -- conflicting private views that Gigi would ignore. If this is
3832 -- predefined unit, analyze with checks off, as is done in the non-
3833 -- inlined run-time units.
3836 I_Flag : constant Boolean := In_Inlined_Body;
3839 In_Inlined_Body := True;
3843 Style : constant Boolean := Style_Check;
3845 Style_Check := False;
3846 Analyze (Blk, Suppress => All_Checks);
3847 Style_Check := Style;
3854 In_Inlined_Body := I_Flag;
3857 if Ekind (Subp) = E_Procedure then
3858 Rewrite_Procedure_Call (N, Blk);
3860 Rewrite_Function_Call (N, Blk);
3862 -- For the unconstrained case, the replacement of the call has been
3863 -- made prior to the complete analysis of the generated declarations.
3864 -- Propagate the proper type now.
3867 if Nkind (N) = N_Identifier then
3868 Set_Etype (N, Etype (Entity (N)));
3870 Set_Etype (N, Etype (Targ1));
3877 -- Cleanup mapping between formals and actuals for other expansions
3879 F := First_Formal (Subp);
3880 while Present (F) loop
3881 Set_Renamed_Object (F, Empty);
3884 end Expand_Inlined_Call;
3886 ----------------------------
3887 -- Expand_N_Function_Call --
3888 ----------------------------
3890 procedure Expand_N_Function_Call (N : Node_Id) is
3891 Typ : constant Entity_Id := Etype (N);
3893 function Returned_By_Reference return Boolean;
3894 -- If the return type is returned through the secondary stack; that is
3895 -- by reference, we don't want to create a temp to force stack checking.
3896 -- ???"sec stack" is not right -- Ada 95 return-by-reference object are
3897 -- returned wherever they are.
3898 -- Shouldn't this function be moved to exp_util???
3900 function Rhs_Of_Assign_Or_Decl (N : Node_Id) return Boolean;
3901 -- If the call is the right side of an assignment or the expression in
3902 -- an object declaration, we don't need to create a temp as the left
3903 -- side will already trigger stack checking if necessary.
3905 -- If the call is a component in an extension aggregate, it will be
3906 -- expanded into assignments as well, so no temporary is needed. This
3907 -- also solves the problem of functions returning types with unknown
3908 -- discriminants, where it is not possible to declare an object of the
3911 ---------------------------
3912 -- Returned_By_Reference --
3913 ---------------------------
3915 function Returned_By_Reference return Boolean is
3919 if Is_Inherently_Limited_Type (Typ) then
3922 elsif Nkind (Parent (N)) /= N_Simple_Return_Statement then
3925 elsif Requires_Transient_Scope (Typ) then
3927 -- Verify that the return type of the enclosing function has the
3928 -- same constrained status as that of the expression.
3931 while Ekind (S) /= E_Function loop
3935 return Is_Constrained (Typ) = Is_Constrained (Etype (S));
3939 end Returned_By_Reference;
3941 ---------------------------
3942 -- Rhs_Of_Assign_Or_Decl --
3943 ---------------------------
3945 function Rhs_Of_Assign_Or_Decl (N : Node_Id) return Boolean is
3947 if (Nkind (Parent (N)) = N_Assignment_Statement
3948 and then Expression (Parent (N)) = N)
3950 (Nkind (Parent (N)) = N_Qualified_Expression
3951 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
3952 and then Expression (Parent (Parent (N))) = Parent (N))
3954 (Nkind (Parent (N)) = N_Object_Declaration
3955 and then Expression (Parent (N)) = N)
3957 (Nkind (Parent (N)) = N_Component_Association
3958 and then Expression (Parent (N)) = N
3959 and then Nkind (Parent (Parent (N))) = N_Aggregate
3960 and then Rhs_Of_Assign_Or_Decl (Parent (Parent (N))))
3962 (Nkind (Parent (N)) = N_Extension_Aggregate
3963 and then Is_Private_Type (Etype (Typ)))
3969 end Rhs_Of_Assign_Or_Decl;
3971 -- Start of processing for Expand_N_Function_Call
3974 -- A special check. If stack checking is enabled, and the return type
3975 -- might generate a large temporary, and the call is not the right side
3976 -- of an assignment, then generate an explicit temporary. We do this
3977 -- because otherwise gigi may generate a large temporary on the fly and
3978 -- this can cause trouble with stack checking.
3980 -- This is unnecessary if the call is the expression in an object
3981 -- declaration, or if it appears outside of any library unit. This can
3982 -- only happen if it appears as an actual in a library-level instance,
3983 -- in which case a temporary will be generated for it once the instance
3984 -- itself is installed.
3986 if May_Generate_Large_Temp (Typ)
3987 and then not Rhs_Of_Assign_Or_Decl (N)
3988 and then not Returned_By_Reference
3989 and then Current_Scope /= Standard_Standard
3991 if Stack_Checking_Enabled then
3993 -- Note: it might be thought that it would be OK to use a call to
3994 -- Force_Evaluation here, but that's not good enough, because
3995 -- that can results in a 'Reference construct that may still need
3999 Loc : constant Source_Ptr := Sloc (N);
4000 Temp_Obj : constant Entity_Id :=
4001 Make_Defining_Identifier (Loc,
4002 Chars => New_Internal_Name ('F'));
4003 Temp_Typ : Entity_Id := Typ;
4010 if Is_Tagged_Type (Typ)
4011 and then Present (Controlling_Argument (N))
4013 if Nkind (Parent (N)) /= N_Procedure_Call_Statement
4014 and then Nkind (Parent (N)) /= N_Function_Call
4016 -- If this is a tag-indeterminate call, the object must
4019 if Is_Tag_Indeterminate (N) then
4020 Temp_Typ := Class_Wide_Type (Typ);
4024 -- If this is a dispatching call that is itself the
4025 -- controlling argument of an enclosing call, the
4026 -- nominal subtype of the object that replaces it must
4027 -- be classwide, so that dispatching will take place
4028 -- properly. If it is not a controlling argument, the
4029 -- object is not classwide.
4031 Proc := Entity (Name (Parent (N)));
4033 F := First_Formal (Proc);
4034 A := First_Actual (Parent (N));
4040 if Is_Controlling_Formal (F) then
4041 Temp_Typ := Class_Wide_Type (Typ);
4047 Make_Object_Declaration (Loc,
4048 Defining_Identifier => Temp_Obj,
4049 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
4050 Constant_Present => True,
4051 Expression => Relocate_Node (N));
4052 Set_Assignment_OK (Decl);
4054 Insert_Actions (N, New_List (Decl));
4055 Rewrite (N, New_Occurrence_Of (Temp_Obj, Loc));
4059 -- If stack-checking is not enabled, increment serial number
4060 -- for internal names, so that subsequent symbols are consistent
4061 -- with and without stack-checking.
4063 Synchronize_Serial_Number;
4065 -- Now we can expand the call with consistent symbol names
4070 -- Normal case, expand the call
4075 end Expand_N_Function_Call;
4077 ---------------------------------------
4078 -- Expand_N_Procedure_Call_Statement --
4079 ---------------------------------------
4081 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
4084 end Expand_N_Procedure_Call_Statement;
4086 ------------------------------
4087 -- Expand_N_Subprogram_Body --
4088 ------------------------------
4090 -- Add poll call if ATC polling is enabled, unless the body will be
4091 -- inlined by the back-end.
4093 -- Add dummy push/pop label nodes at start and end to clear any local
4094 -- exception indications if local-exception-to-goto optimization active.
4096 -- Add return statement if last statement in body is not a return statement
4097 -- (this makes things easier on Gigi which does not want to have to handle
4098 -- a missing return).
4100 -- Add call to Activate_Tasks if body is a task activator
4102 -- Deal with possible detection of infinite recursion
4104 -- Eliminate body completely if convention stubbed
4106 -- Encode entity names within body, since we will not need to reference
4107 -- these entities any longer in the front end.
4109 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
4111 -- Reset Pure indication if any parameter has root type System.Address
4115 procedure Expand_N_Subprogram_Body (N : Node_Id) is
4116 Loc : constant Source_Ptr := Sloc (N);
4117 H : constant Node_Id := Handled_Statement_Sequence (N);
4118 Body_Id : Entity_Id;
4119 Spec_Id : Entity_Id;
4126 procedure Add_Return (S : List_Id);
4127 -- Append a return statement to the statement sequence S if the last
4128 -- statement is not already a return or a goto statement. Note that
4129 -- the latter test is not critical, it does not matter if we add a
4130 -- few extra returns, since they get eliminated anyway later on.
4136 procedure Add_Return (S : List_Id) is
4141 -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
4142 -- not relevant in this context since they are not executable.
4144 Last_Stm := Last (S);
4145 while Nkind (Last_Stm) in N_Pop_xxx_Label loop
4149 -- Now insert return unless last statement is a transfer
4151 if not Is_Transfer (Last_Stm) then
4153 -- The source location for the return is the end label of the
4154 -- procedure if present. Otherwise use the sloc of the last
4155 -- statement in the list. If the list comes from a generated
4156 -- exception handler and we are not debugging generated code,
4157 -- all the statements within the handler are made invisible
4160 if Nkind (Parent (S)) = N_Exception_Handler
4161 and then not Comes_From_Source (Parent (S))
4163 Loc := Sloc (Last_Stm);
4165 elsif Present (End_Label (H)) then
4166 Loc := Sloc (End_Label (H));
4169 Loc := Sloc (Last_Stm);
4172 Append_To (S, Make_Simple_Return_Statement (Loc));
4176 -- Start of processing for Expand_N_Subprogram_Body
4179 -- Set L to either the list of declarations if present, or
4180 -- to the list of statements if no declarations are present.
4181 -- This is used to insert new stuff at the start.
4183 if Is_Non_Empty_List (Declarations (N)) then
4184 L := Declarations (N);
4186 L := Statements (H);
4189 -- If local-exception-to-goto optimization active, insert dummy push
4190 -- statements at start, and dummy pop statements at end.
4192 if (Debug_Flag_Dot_G
4193 or else Restriction_Active (No_Exception_Propagation))
4194 and then Is_Non_Empty_List (L)
4197 FS : constant Node_Id := First (L);
4198 FL : constant Source_Ptr := Sloc (FS);
4203 -- LS points to either last statement, if statements are present
4204 -- or to the last declaration if there are no statements present.
4205 -- It is the node after which the pop's are generated.
4207 if Is_Non_Empty_List (Statements (H)) then
4208 LS := Last (Statements (H));
4215 Insert_List_Before_And_Analyze (FS, New_List (
4216 Make_Push_Constraint_Error_Label (FL),
4217 Make_Push_Program_Error_Label (FL),
4218 Make_Push_Storage_Error_Label (FL)));
4220 Insert_List_After_And_Analyze (LS, New_List (
4221 Make_Pop_Constraint_Error_Label (LL),
4222 Make_Pop_Program_Error_Label (LL),
4223 Make_Pop_Storage_Error_Label (LL)));
4227 -- Find entity for subprogram
4229 Body_Id := Defining_Entity (N);
4231 if Present (Corresponding_Spec (N)) then
4232 Spec_Id := Corresponding_Spec (N);
4237 -- Need poll on entry to subprogram if polling enabled. We only do this
4238 -- for non-empty subprograms, since it does not seem necessary to poll
4239 -- for a dummy null subprogram. Do not add polling point if calls to
4240 -- this subprogram will be inlined by the back-end, to avoid repeated
4241 -- polling points in nested inlinings.
4243 if Is_Non_Empty_List (L) then
4244 if Is_Inlined (Spec_Id)
4245 and then Front_End_Inlining
4246 and then Optimization_Level > 1
4250 Generate_Poll_Call (First (L));
4254 -- If this is a Pure function which has any parameters whose root
4255 -- type is System.Address, reset the Pure indication, since it will
4256 -- likely cause incorrect code to be generated as the parameter is
4257 -- probably a pointer, and the fact that the same pointer is passed
4258 -- does not mean that the same value is being referenced.
4260 -- Note that if the programmer gave an explicit Pure_Function pragma,
4261 -- then we believe the programmer, and leave the subprogram Pure.
4263 -- This code should probably be at the freeze point, so that it
4264 -- happens even on a -gnatc (or more importantly -gnatt) compile
4265 -- so that the semantic tree has Is_Pure set properly ???
4267 if Is_Pure (Spec_Id)
4268 and then Is_Subprogram (Spec_Id)
4269 and then not Has_Pragma_Pure_Function (Spec_Id)
4275 F := First_Formal (Spec_Id);
4276 while Present (F) loop
4277 if Is_Descendent_Of_Address (Etype (F)) then
4278 Set_Is_Pure (Spec_Id, False);
4280 if Spec_Id /= Body_Id then
4281 Set_Is_Pure (Body_Id, False);
4292 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
4294 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
4299 -- Loop through formals
4301 F := First_Formal (Spec_Id);
4302 while Present (F) loop
4303 if Is_Scalar_Type (Etype (F))
4304 and then Ekind (F) = E_Out_Parameter
4306 -- Insert the initialization. We turn off validity checks
4307 -- for this assignment, since we do not want any check on
4308 -- the initial value itself (which may well be invalid).
4310 Insert_Before_And_Analyze (First (L),
4311 Make_Assignment_Statement (Loc,
4312 Name => New_Occurrence_Of (F, Loc),
4313 Expression => Get_Simple_Init_Val (Etype (F), Loc)),
4314 Suppress => Validity_Check);
4322 Scop := Scope (Spec_Id);
4324 -- Add discriminal renamings to protected subprograms. Install new
4325 -- discriminals for expansion of the next subprogram of this protected
4328 if Is_List_Member (N)
4329 and then Present (Parent (List_Containing (N)))
4330 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
4332 Add_Discriminal_Declarations
4333 (Declarations (N), Scop, Name_uObject, Loc);
4334 Add_Private_Declarations
4335 (Declarations (N), Scop, Name_uObject, Loc);
4337 -- Associate privals and discriminals with the next protected
4338 -- operation body to be expanded. These are used to expand references
4339 -- to private data objects and discriminants, respectively.
4341 Next_Op := Next_Protected_Operation (N);
4343 if Present (Next_Op) then
4344 Dec := Parent (Base_Type (Scop));
4345 Set_Privals (Dec, Next_Op, Loc);
4346 Set_Discriminals (Dec);
4350 -- Clear out statement list for stubbed procedure
4352 if Present (Corresponding_Spec (N)) then
4353 Set_Elaboration_Flag (N, Spec_Id);
4355 if Convention (Spec_Id) = Convention_Stubbed
4356 or else Is_Eliminated (Spec_Id)
4358 Set_Declarations (N, Empty_List);
4359 Set_Handled_Statement_Sequence (N,
4360 Make_Handled_Sequence_Of_Statements (Loc,
4361 Statements => New_List (
4362 Make_Null_Statement (Loc))));
4367 -- Returns_By_Ref flag is normally set when the subprogram is frozen
4368 -- but subprograms with no specs are not frozen.
4371 Typ : constant Entity_Id := Etype (Spec_Id);
4372 Utyp : constant Entity_Id := Underlying_Type (Typ);
4375 if not Acts_As_Spec (N)
4376 and then Nkind (Parent (Parent (Spec_Id))) /=
4377 N_Subprogram_Body_Stub
4381 elsif Is_Inherently_Limited_Type (Typ) then
4382 Set_Returns_By_Ref (Spec_Id);
4384 elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
4385 Set_Returns_By_Ref (Spec_Id);
4389 -- For a procedure, we add a return for all possible syntactic ends
4390 -- of the subprogram. Note that reanalysis is not necessary in this
4391 -- case since it would require a lot of work and accomplish nothing.
4393 if Ekind (Spec_Id) = E_Procedure
4394 or else Ekind (Spec_Id) = E_Generic_Procedure
4396 Add_Return (Statements (H));
4398 if Present (Exception_Handlers (H)) then
4399 Except_H := First_Non_Pragma (Exception_Handlers (H));
4400 while Present (Except_H) loop
4401 Add_Return (Statements (Except_H));
4402 Next_Non_Pragma (Except_H);
4406 -- For a function, we must deal with the case where there is at least
4407 -- one missing return. What we do is to wrap the entire body of the
4408 -- function in a block:
4421 -- raise Program_Error;
4424 -- This approach is necessary because the raise must be signalled
4425 -- to the caller, not handled by any local handler (RM 6.4(11)).
4427 -- Note: we do not need to analyze the constructed sequence here,
4428 -- since it has no handler, and an attempt to analyze the handled
4429 -- statement sequence twice is risky in various ways (e.g. the
4430 -- issue of expanding cleanup actions twice).
4432 elsif Has_Missing_Return (Spec_Id) then
4434 Hloc : constant Source_Ptr := Sloc (H);
4435 Blok : constant Node_Id :=
4436 Make_Block_Statement (Hloc,
4437 Handled_Statement_Sequence => H);
4438 Rais : constant Node_Id :=
4439 Make_Raise_Program_Error (Hloc,
4440 Reason => PE_Missing_Return);
4443 Set_Handled_Statement_Sequence (N,
4444 Make_Handled_Sequence_Of_Statements (Hloc,
4445 Statements => New_List (Blok, Rais)));
4447 Push_Scope (Spec_Id);
4454 -- If subprogram contains a parameterless recursive call, then we may
4455 -- have an infinite recursion, so see if we can generate code to check
4456 -- for this possibility if storage checks are not suppressed.
4458 if Ekind (Spec_Id) = E_Procedure
4459 and then Has_Recursive_Call (Spec_Id)
4460 and then not Storage_Checks_Suppressed (Spec_Id)
4462 Detect_Infinite_Recursion (N, Spec_Id);
4465 -- Finally, if we are in Normalize_Scalars mode, then any scalar out
4466 -- parameters must be initialized to the appropriate default value.
4468 if Ekind (Spec_Id) = E_Procedure and then Normalize_Scalars then
4475 Formal := First_Formal (Spec_Id);
4476 while Present (Formal) loop
4477 Floc := Sloc (Formal);
4479 if Ekind (Formal) = E_Out_Parameter
4480 and then Is_Scalar_Type (Etype (Formal))
4483 Make_Assignment_Statement (Floc,
4484 Name => New_Occurrence_Of (Formal, Floc),
4486 Get_Simple_Init_Val (Etype (Formal), Floc));
4487 Prepend (Stm, Declarations (N));
4491 Next_Formal (Formal);
4496 -- Set to encode entity names in package body before gigi is called
4498 Qualify_Entity_Names (N);
4499 end Expand_N_Subprogram_Body;
4501 -----------------------------------
4502 -- Expand_N_Subprogram_Body_Stub --
4503 -----------------------------------
4505 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
4507 if Present (Corresponding_Body (N)) then
4508 Expand_N_Subprogram_Body (
4509 Unit_Declaration_Node (Corresponding_Body (N)));
4511 end Expand_N_Subprogram_Body_Stub;
4513 -------------------------------------
4514 -- Expand_N_Subprogram_Declaration --
4515 -------------------------------------
4517 -- If the declaration appears within a protected body, it is a private
4518 -- operation of the protected type. We must create the corresponding
4519 -- protected subprogram an associated formals. For a normal protected
4520 -- operation, this is done when expanding the protected type declaration.
4522 -- If the declaration is for a null procedure, emit null body
4524 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
4525 Loc : constant Source_Ptr := Sloc (N);
4526 Subp : constant Entity_Id := Defining_Entity (N);
4527 Scop : constant Entity_Id := Scope (Subp);
4528 Prot_Decl : Node_Id;
4530 Prot_Id : Entity_Id;
4533 -- Deal with case of protected subprogram. Do not generate protected
4534 -- operation if operation is flagged as eliminated.
4536 if Is_List_Member (N)
4537 and then Present (Parent (List_Containing (N)))
4538 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
4539 and then Is_Protected_Type (Scop)
4541 if No (Protected_Body_Subprogram (Subp))
4542 and then not Is_Eliminated (Subp)
4545 Make_Subprogram_Declaration (Loc,
4547 Build_Protected_Sub_Specification
4548 (N, Scop, Unprotected_Mode));
4550 -- The protected subprogram is declared outside of the protected
4551 -- body. Given that the body has frozen all entities so far, we
4552 -- analyze the subprogram and perform freezing actions explicitly.
4553 -- including the generation of an explicit freeze node, to ensure
4554 -- that gigi has the proper order of elaboration.
4555 -- If the body is a subunit, the insertion point is before the
4556 -- stub in the parent.
4558 Prot_Bod := Parent (List_Containing (N));
4560 if Nkind (Parent (Prot_Bod)) = N_Subunit then
4561 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
4564 Insert_Before (Prot_Bod, Prot_Decl);
4565 Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
4566 Set_Has_Delayed_Freeze (Prot_Id);
4568 Push_Scope (Scope (Scop));
4569 Analyze (Prot_Decl);
4570 Insert_Actions (N, Freeze_Entity (Prot_Id, Loc));
4571 Set_Protected_Body_Subprogram (Subp, Prot_Id);
4575 -- Ada 2005 (AI-348): Generation of the null body
4577 elsif Nkind (Specification (N)) = N_Procedure_Specification
4578 and then Null_Present (Specification (N))
4581 Bod : constant Node_Id :=
4582 Make_Subprogram_Body (Loc,
4584 New_Copy_Tree (Specification (N)),
4585 Declarations => New_List,
4586 Handled_Statement_Sequence =>
4587 Make_Handled_Sequence_Of_Statements (Loc,
4588 Statements => New_List (Make_Null_Statement (Loc))));
4590 Set_Body_To_Inline (N, Bod);
4591 Insert_After (N, Bod);
4594 -- Corresponding_Spec isn't being set by Analyze_Subprogram_Body,
4595 -- evidently because Set_Has_Completion is called earlier for null
4596 -- procedures in Analyze_Subprogram_Declaration, so we force its
4597 -- setting here. If the setting of Has_Completion is not set
4598 -- earlier, then it can result in missing body errors if other
4599 -- errors were already reported (since expansion is turned off).
4601 -- Should creation of the empty body be moved to the analyzer???
4603 Set_Corresponding_Spec (Bod, Defining_Entity (Specification (N)));
4606 end Expand_N_Subprogram_Declaration;
4608 ---------------------------------------
4609 -- Expand_Protected_Object_Reference --
4610 ---------------------------------------
4612 function Expand_Protected_Object_Reference
4614 Scop : Entity_Id) return Node_Id
4616 Loc : constant Source_Ptr := Sloc (N);
4624 Make_Identifier (Loc,
4625 Chars => Name_uObject);
4626 Set_Etype (Rec, Corresponding_Record_Type (Scop));
4628 -- Find enclosing protected operation, and retrieve its first parameter,
4629 -- which denotes the enclosing protected object. If the enclosing
4630 -- operation is an entry, we are immediately within the protected body,
4631 -- and we can retrieve the object from the service entries procedure. A
4632 -- barrier function has has the same signature as an entry. A barrier
4633 -- function is compiled within the protected object, but unlike
4634 -- protected operations its never needs locks, so that its protected
4635 -- body subprogram points to itself.
4637 Proc := Current_Scope;
4638 while Present (Proc)
4639 and then Scope (Proc) /= Scop
4641 Proc := Scope (Proc);
4644 Corr := Protected_Body_Subprogram (Proc);
4648 -- Previous error left expansion incomplete.
4649 -- Nothing to do on this call.
4656 (First (Parameter_Specifications (Parent (Corr))));
4658 if Is_Subprogram (Proc)
4659 and then Proc /= Corr
4661 -- Protected function or procedure
4663 Set_Entity (Rec, Param);
4665 -- Rec is a reference to an entity which will not be in scope when
4666 -- the call is reanalyzed, and needs no further analysis.
4671 -- Entry or barrier function for entry body. The first parameter of
4672 -- the entry body procedure is pointer to the object. We create a
4673 -- local variable of the proper type, duplicating what is done to
4674 -- define _object later on.
4678 Obj_Ptr : constant Entity_Id := Make_Defining_Identifier (Loc,
4680 New_Internal_Name ('T'));
4684 Make_Full_Type_Declaration (Loc,
4685 Defining_Identifier => Obj_Ptr,
4687 Make_Access_To_Object_Definition (Loc,
4688 Subtype_Indication =>
4690 (Corresponding_Record_Type (Scop), Loc))));
4692 Insert_Actions (N, Decls);
4693 Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
4696 Make_Explicit_Dereference (Loc,
4697 Unchecked_Convert_To (Obj_Ptr,
4698 New_Occurrence_Of (Param, Loc)));
4700 -- Analyze new actual. Other actuals in calls are already analyzed
4701 -- and the list of actuals is not reanalyzed after rewriting.
4703 Set_Parent (Rec, N);
4709 end Expand_Protected_Object_Reference;
4711 --------------------------------------
4712 -- Expand_Protected_Subprogram_Call --
4713 --------------------------------------
4715 procedure Expand_Protected_Subprogram_Call
4723 -- If the protected object is not an enclosing scope, this is
4724 -- an inter-object function call. Inter-object procedure
4725 -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
4726 -- The call is intra-object only if the subprogram being
4727 -- called is in the protected body being compiled, and if the
4728 -- protected object in the call is statically the enclosing type.
4729 -- The object may be an component of some other data structure,
4730 -- in which case this must be handled as an inter-object call.
4732 if not In_Open_Scopes (Scop)
4733 or else not Is_Entity_Name (Name (N))
4735 if Nkind (Name (N)) = N_Selected_Component then
4736 Rec := Prefix (Name (N));
4739 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
4740 Rec := Prefix (Prefix (Name (N)));
4743 Build_Protected_Subprogram_Call (N,
4744 Name => New_Occurrence_Of (Subp, Sloc (N)),
4745 Rec => Convert_Concurrent (Rec, Etype (Rec)),
4749 Rec := Expand_Protected_Object_Reference (N, Scop);
4755 Build_Protected_Subprogram_Call (N,
4764 -- If it is a function call it can appear in elaboration code and
4765 -- the called entity must be frozen here.
4767 if Ekind (Subp) = E_Function then
4768 Freeze_Expression (Name (N));
4770 end Expand_Protected_Subprogram_Call;
4772 --------------------------------
4773 -- Is_Build_In_Place_Function --
4774 --------------------------------
4776 function Is_Build_In_Place_Function (E : Entity_Id) return Boolean is
4778 -- For now we test whether E denotes a function or access-to-function
4779 -- type whose result subtype is inherently limited. Later this test may
4780 -- be revised to allow composite nonlimited types. Functions with a
4781 -- foreign convention or whose result type has a foreign convention
4784 if Ekind (E) = E_Function
4785 or else Ekind (E) = E_Generic_Function
4786 or else (Ekind (E) = E_Subprogram_Type
4787 and then Etype (E) /= Standard_Void_Type)
4789 -- Note: If you have Convention (C) on an inherently limited type,
4790 -- you're on your own. That is, the C code will have to be carefully
4791 -- written to know about the Ada conventions.
4793 if Has_Foreign_Convention (E)
4794 or else Has_Foreign_Convention (Etype (E))
4798 -- If the return type is a limited interface it has to be treated
4799 -- as a return in place, even if the actual object is some non-
4800 -- limited descendant.
4802 elsif Is_Limited_Interface (Etype (E)) then
4806 return Is_Inherently_Limited_Type (Etype (E))
4807 and then Ada_Version >= Ada_05
4808 and then not Debug_Flag_Dot_L;
4814 end Is_Build_In_Place_Function;
4816 -------------------------------------
4817 -- Is_Build_In_Place_Function_Call --
4818 -------------------------------------
4820 function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean is
4821 Exp_Node : Node_Id := N;
4822 Function_Id : Entity_Id;
4825 -- Step past qualification or unchecked conversion (the latter can occur
4826 -- in cases of calls to 'Input).
4828 if Nkind (Exp_Node) = N_Qualified_Expression
4829 or else Nkind (Exp_Node) = N_Unchecked_Type_Conversion
4831 Exp_Node := Expression (N);
4834 if Nkind (Exp_Node) /= N_Function_Call then
4838 if Is_Entity_Name (Name (Exp_Node)) then
4839 Function_Id := Entity (Name (Exp_Node));
4841 elsif Nkind (Name (Exp_Node)) = N_Explicit_Dereference then
4842 Function_Id := Etype (Name (Exp_Node));
4845 return Is_Build_In_Place_Function (Function_Id);
4847 end Is_Build_In_Place_Function_Call;
4849 ---------------------------------------
4850 -- Is_Build_In_Place_Function_Return --
4851 ---------------------------------------
4853 function Is_Build_In_Place_Function_Return (N : Node_Id) return Boolean is
4855 if Nkind (N) = N_Simple_Return_Statement
4856 or else Nkind (N) = N_Extended_Return_Statement
4858 return Is_Build_In_Place_Function
4859 (Return_Applies_To (Return_Statement_Entity (N)));
4863 end Is_Build_In_Place_Function_Return;
4865 -----------------------
4866 -- Freeze_Subprogram --
4867 -----------------------
4869 procedure Freeze_Subprogram (N : Node_Id) is
4870 Loc : constant Source_Ptr := Sloc (N);
4872 procedure Register_Predefined_DT_Entry (Prim : Entity_Id);
4873 -- (Ada 2005): Register a predefined primitive in all the secondary
4874 -- dispatch tables of its primitive type.
4876 ----------------------------------
4877 -- Register_Predefined_DT_Entry --
4878 ----------------------------------
4880 procedure Register_Predefined_DT_Entry (Prim : Entity_Id) is
4881 Iface_DT_Ptr : Elmt_Id;
4882 Tagged_Typ : Entity_Id;
4883 Thunk_Id : Entity_Id;
4884 Thunk_Code : Node_Id;
4887 Tagged_Typ := Find_Dispatching_Type (Prim);
4889 if No (Access_Disp_Table (Tagged_Typ))
4890 or else not Has_Abstract_Interfaces (Tagged_Typ)
4891 or else not RTE_Available (RE_Interface_Tag)
4892 or else Restriction_Active (No_Dispatching_Calls)
4897 -- Skip the first access-to-dispatch-table pointer since it leads
4898 -- to the primary dispatch table. We are only concerned with the
4899 -- secondary dispatch table pointers. Note that the access-to-
4900 -- dispatch-table pointer corresponds to the first implemented
4901 -- interface retrieved below.
4904 Next_Elmt (First_Elmt (Access_Disp_Table (Tagged_Typ)));
4906 while Present (Iface_DT_Ptr)
4907 and then Ekind (Node (Iface_DT_Ptr)) = E_Constant
4909 Expand_Interface_Thunk (Prim, Thunk_Id, Thunk_Code);
4911 if Present (Thunk_Code) then
4912 Insert_Actions (N, New_List (
4915 Build_Set_Predefined_Prim_Op_Address (Loc,
4916 Tag_Node => New_Reference_To (Node (Iface_DT_Ptr), Loc),
4917 Position => DT_Position (Prim),
4919 Make_Attribute_Reference (Loc,
4920 Prefix => New_Reference_To (Thunk_Id, Loc),
4921 Attribute_Name => Name_Address))));
4924 Next_Elmt (Iface_DT_Ptr);
4926 end Register_Predefined_DT_Entry;
4930 Subp : constant Entity_Id := Entity (N);
4933 -- We suppress the initialization of the dispatch table entry when
4934 -- VM_Target because the dispatching mechanism is handled internally
4937 if Is_Dispatching_Operation (Subp)
4938 and then not Is_Abstract_Subprogram (Subp)
4939 and then Present (DTC_Entity (Subp))
4940 and then Present (Scope (DTC_Entity (Subp)))
4941 and then VM_Target = No_VM
4942 and then not Restriction_Active (No_Dispatching_Calls)
4943 and then RTE_Available (RE_Tag)
4946 Typ : constant Entity_Id := Scope (DTC_Entity (Subp));
4949 -- Handle private overriden primitives
4951 if not Is_CPP_Class (Typ) then
4952 Check_Overriding_Operation (Subp);
4955 -- We assume that imported CPP primitives correspond with objects
4956 -- whose constructor is in the CPP side; therefore we don't need
4957 -- to generate code to register them in the dispatch table.
4959 if Is_CPP_Class (Typ) then
4962 -- Handle CPP primitives found in derivations of CPP_Class types.
4963 -- These primitives must have been inherited from some parent, and
4964 -- there is no need to register them in the dispatch table because
4965 -- Build_Inherit_Prims takes care of the initialization of these
4968 elsif Is_Imported (Subp)
4969 and then (Convention (Subp) = Convention_CPP
4970 or else Convention (Subp) = Convention_C)
4974 -- Generate code to register the primitive in non statically
4975 -- allocated dispatch tables
4977 elsif not Static_Dispatch_Tables
4979 Is_Library_Level_Tagged_Type (Scope (DTC_Entity (Subp)))
4981 -- When a primitive is frozen, enter its name in its dispatch
4984 if not Is_Interface (Typ)
4985 or else Present (Abstract_Interface_Alias (Subp))
4987 if Is_Predefined_Dispatching_Operation (Subp) then
4988 Register_Predefined_DT_Entry (Subp);
4991 Register_Primitive (Loc,
4999 -- Mark functions that return by reference. Note that it cannot be part
5000 -- of the normal semantic analysis of the spec since the underlying
5001 -- returned type may not be known yet (for private types).
5004 Typ : constant Entity_Id := Etype (Subp);
5005 Utyp : constant Entity_Id := Underlying_Type (Typ);
5007 if Is_Inherently_Limited_Type (Typ) then
5008 Set_Returns_By_Ref (Subp);
5009 elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
5010 Set_Returns_By_Ref (Subp);
5013 end Freeze_Subprogram;
5015 -------------------------------------------
5016 -- Make_Build_In_Place_Call_In_Allocator --
5017 -------------------------------------------
5019 procedure Make_Build_In_Place_Call_In_Allocator
5020 (Allocator : Node_Id;
5021 Function_Call : Node_Id)
5024 Func_Call : Node_Id := Function_Call;
5025 Function_Id : Entity_Id;
5026 Result_Subt : Entity_Id;
5027 Acc_Type : constant Entity_Id := Etype (Allocator);
5028 New_Allocator : Node_Id;
5029 Return_Obj_Access : Entity_Id;
5032 -- Step past qualification or unchecked conversion (the latter can occur
5033 -- in cases of calls to 'Input).
5035 if Nkind (Func_Call) = N_Qualified_Expression
5036 or else Nkind (Func_Call) = N_Unchecked_Type_Conversion
5038 Func_Call := Expression (Func_Call);
5041 Loc := Sloc (Function_Call);
5043 if Is_Entity_Name (Name (Func_Call)) then
5044 Function_Id := Entity (Name (Func_Call));
5046 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5047 Function_Id := Etype (Name (Func_Call));
5050 raise Program_Error;
5053 Result_Subt := Etype (Function_Id);
5055 -- When the result subtype is constrained, the return object must be
5056 -- allocated on the caller side, and access to it is passed to the
5059 -- Here and in related routines, we must examine the full view of the
5060 -- type, because the view at the point of call may differ from that
5061 -- that in the function body, and the expansion mechanism depends on
5062 -- the characteristics of the full view.
5064 if Is_Constrained (Underlying_Type (Result_Subt)) then
5066 -- Replace the initialized allocator of form "new T'(Func (...))"
5067 -- with an uninitialized allocator of form "new T", where T is the
5068 -- result subtype of the called function. The call to the function
5069 -- is handled separately further below.
5072 Make_Allocator (Loc, New_Reference_To (Result_Subt, Loc));
5074 Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
5075 Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
5076 Set_No_Initialization (New_Allocator);
5078 Rewrite (Allocator, New_Allocator);
5080 -- Create a new access object and initialize it to the result of the
5081 -- new uninitialized allocator.
5083 Return_Obj_Access :=
5084 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
5085 Set_Etype (Return_Obj_Access, Acc_Type);
5087 Insert_Action (Allocator,
5088 Make_Object_Declaration (Loc,
5089 Defining_Identifier => Return_Obj_Access,
5090 Object_Definition => New_Reference_To (Acc_Type, Loc),
5091 Expression => Relocate_Node (Allocator)));
5093 -- When the function has a controlling result, an allocation-form
5094 -- parameter must be passed indicating that the caller is allocating
5095 -- the result object. This is needed because such a function can be
5096 -- called as a dispatching operation and must be treated similarly
5097 -- to functions with unconstrained result subtypes.
5099 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5100 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5102 Add_Final_List_Actual_To_Build_In_Place_Call
5103 (Func_Call, Function_Id, Acc_Type);
5105 Add_Task_Actuals_To_Build_In_Place_Call
5106 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
5108 -- Add an implicit actual to the function call that provides access
5109 -- to the allocated object. An unchecked conversion to the (specific)
5110 -- result subtype of the function is inserted to handle cases where
5111 -- the access type of the allocator has a class-wide designated type.
5113 Add_Access_Actual_To_Build_In_Place_Call
5116 Make_Unchecked_Type_Conversion (Loc,
5117 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5119 Make_Explicit_Dereference (Loc,
5120 Prefix => New_Reference_To (Return_Obj_Access, Loc))));
5122 -- When the result subtype is unconstrained, the function itself must
5123 -- perform the allocation of the return object, so we pass parameters
5124 -- indicating that. We don't yet handle the case where the allocation
5125 -- must be done in a user-defined storage pool, which will require
5126 -- passing another actual or two to provide allocation/deallocation
5131 -- Pass an allocation parameter indicating that the function should
5132 -- allocate its result on the heap.
5134 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5135 (Func_Call, Function_Id, Alloc_Form => Global_Heap);
5137 Add_Final_List_Actual_To_Build_In_Place_Call
5138 (Func_Call, Function_Id, Acc_Type);
5140 Add_Task_Actuals_To_Build_In_Place_Call
5141 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
5143 -- The caller does not provide the return object in this case, so we
5144 -- have to pass null for the object access actual.
5146 Add_Access_Actual_To_Build_In_Place_Call
5147 (Func_Call, Function_Id, Return_Object => Empty);
5150 -- Finally, replace the allocator node with a reference to the result
5151 -- of the function call itself (which will effectively be an access
5152 -- to the object created by the allocator).
5154 Rewrite (Allocator, Make_Reference (Loc, Relocate_Node (Function_Call)));
5155 Analyze_And_Resolve (Allocator, Acc_Type);
5156 end Make_Build_In_Place_Call_In_Allocator;
5158 ---------------------------------------------------
5159 -- Make_Build_In_Place_Call_In_Anonymous_Context --
5160 ---------------------------------------------------
5162 procedure Make_Build_In_Place_Call_In_Anonymous_Context
5163 (Function_Call : Node_Id)
5166 Func_Call : Node_Id := Function_Call;
5167 Function_Id : Entity_Id;
5168 Result_Subt : Entity_Id;
5169 Return_Obj_Id : Entity_Id;
5170 Return_Obj_Decl : Entity_Id;
5173 -- Step past qualification or unchecked conversion (the latter can occur
5174 -- in cases of calls to 'Input).
5176 if Nkind (Func_Call) = N_Qualified_Expression
5177 or else Nkind (Func_Call) = N_Unchecked_Type_Conversion
5179 Func_Call := Expression (Func_Call);
5182 Loc := Sloc (Function_Call);
5184 if Is_Entity_Name (Name (Func_Call)) then
5185 Function_Id := Entity (Name (Func_Call));
5187 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5188 Function_Id := Etype (Name (Func_Call));
5191 raise Program_Error;
5194 Result_Subt := Etype (Function_Id);
5196 -- When the result subtype is constrained, an object of the subtype is
5197 -- declared and an access value designating it is passed as an actual.
5199 if Is_Constrained (Underlying_Type (Result_Subt)) then
5201 -- Create a temporary object to hold the function result
5204 Make_Defining_Identifier (Loc,
5205 Chars => New_Internal_Name ('R'));
5206 Set_Etype (Return_Obj_Id, Result_Subt);
5209 Make_Object_Declaration (Loc,
5210 Defining_Identifier => Return_Obj_Id,
5211 Aliased_Present => True,
5212 Object_Definition => New_Reference_To (Result_Subt, Loc));
5214 Set_No_Initialization (Return_Obj_Decl);
5216 Insert_Action (Func_Call, Return_Obj_Decl);
5218 -- When the function has a controlling result, an allocation-form
5219 -- parameter must be passed indicating that the caller is allocating
5220 -- the result object. This is needed because such a function can be
5221 -- called as a dispatching operation and must be treated similarly
5222 -- to functions with unconstrained result subtypes.
5224 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5225 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5227 Add_Final_List_Actual_To_Build_In_Place_Call
5228 (Func_Call, Function_Id, Acc_Type => Empty);
5230 Add_Task_Actuals_To_Build_In_Place_Call
5231 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5233 -- Add an implicit actual to the function call that provides access
5234 -- to the caller's return object.
5236 Add_Access_Actual_To_Build_In_Place_Call
5237 (Func_Call, Function_Id, New_Reference_To (Return_Obj_Id, Loc));
5239 -- When the result subtype is unconstrained, the function must allocate
5240 -- the return object in the secondary stack, so appropriate implicit
5241 -- parameters are added to the call to indicate that. A transient
5242 -- scope is established to ensure eventual cleanup of the result.
5246 -- Pass an allocation parameter indicating that the function should
5247 -- allocate its result on the secondary stack.
5249 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5250 (Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
5252 Add_Final_List_Actual_To_Build_In_Place_Call
5253 (Func_Call, Function_Id, Acc_Type => Empty);
5255 Add_Task_Actuals_To_Build_In_Place_Call
5256 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5258 -- Pass a null value to the function since no return object is
5259 -- available on the caller side.
5261 Add_Access_Actual_To_Build_In_Place_Call
5262 (Func_Call, Function_Id, Empty);
5264 Establish_Transient_Scope (Func_Call, Sec_Stack => True);
5266 end Make_Build_In_Place_Call_In_Anonymous_Context;
5268 ---------------------------------------------------
5269 -- Make_Build_In_Place_Call_In_Assignment --
5270 ---------------------------------------------------
5272 procedure Make_Build_In_Place_Call_In_Assignment
5274 Function_Call : Node_Id)
5276 Lhs : constant Node_Id := Name (Assign);
5278 Func_Call : Node_Id := Function_Call;
5279 Function_Id : Entity_Id;
5280 Result_Subt : Entity_Id;
5281 Ref_Type : Entity_Id;
5282 Ptr_Typ_Decl : Node_Id;
5287 -- Step past qualification or unchecked conversion (the latter can occur
5288 -- in cases of calls to 'Input).
5290 if Nkind (Func_Call) = N_Qualified_Expression
5291 or else Nkind (Func_Call) = N_Unchecked_Type_Conversion
5293 Func_Call := Expression (Func_Call);
5296 Loc := Sloc (Function_Call);
5298 if Is_Entity_Name (Name (Func_Call)) then
5299 Function_Id := Entity (Name (Func_Call));
5301 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5302 Function_Id := Etype (Name (Func_Call));
5305 raise Program_Error;
5308 Result_Subt := Etype (Function_Id);
5310 -- When the result subtype is unconstrained, an additional actual must
5311 -- be passed to indicate that the caller is providing the return object.
5312 -- This parameter must also be passed when the called function has a
5313 -- controlling result, because dispatching calls to the function needs
5314 -- to be treated effectively the same as calls to class-wide functions.
5316 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5317 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5319 Add_Final_List_Actual_To_Build_In_Place_Call
5320 (Func_Call, Function_Id, Acc_Type => Empty);
5322 Add_Task_Actuals_To_Build_In_Place_Call
5323 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5325 -- Add an implicit actual to the function call that provides access to
5326 -- the caller's return object.
5328 Add_Access_Actual_To_Build_In_Place_Call
5331 Make_Unchecked_Type_Conversion (Loc,
5332 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5333 Expression => Relocate_Node (Lhs)));
5335 -- Create an access type designating the function's result subtype
5338 Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
5341 Make_Full_Type_Declaration (Loc,
5342 Defining_Identifier => Ref_Type,
5344 Make_Access_To_Object_Definition (Loc,
5345 All_Present => True,
5346 Subtype_Indication =>
5347 New_Reference_To (Result_Subt, Loc)));
5349 Insert_After_And_Analyze (Assign, Ptr_Typ_Decl);
5351 -- Finally, create an access object initialized to a reference to the
5355 Make_Defining_Identifier (Loc,
5356 Chars => New_Internal_Name ('R'));
5357 Set_Etype (Def_Id, Ref_Type);
5360 Make_Reference (Loc,
5361 Prefix => Relocate_Node (Func_Call));
5363 Insert_After_And_Analyze (Ptr_Typ_Decl,
5364 Make_Object_Declaration (Loc,
5365 Defining_Identifier => Def_Id,
5366 Object_Definition => New_Reference_To (Ref_Type, Loc),
5367 Expression => New_Expr));
5369 Rewrite (Assign, Make_Null_Statement (Loc));
5370 end Make_Build_In_Place_Call_In_Assignment;
5372 ----------------------------------------------------
5373 -- Make_Build_In_Place_Call_In_Object_Declaration --
5374 ----------------------------------------------------
5376 procedure Make_Build_In_Place_Call_In_Object_Declaration
5377 (Object_Decl : Node_Id;
5378 Function_Call : Node_Id)
5381 Obj_Def_Id : constant Entity_Id :=
5382 Defining_Identifier (Object_Decl);
5384 Func_Call : Node_Id := Function_Call;
5385 Function_Id : Entity_Id;
5386 Result_Subt : Entity_Id;
5387 Caller_Object : Node_Id;
5388 Call_Deref : Node_Id;
5389 Ref_Type : Entity_Id;
5390 Ptr_Typ_Decl : Node_Id;
5393 Enclosing_Func : Entity_Id;
5394 Pass_Caller_Acc : Boolean := False;
5397 -- Step past qualification or unchecked conversion (the latter can occur
5398 -- in cases of calls to 'Input).
5400 if Nkind (Func_Call) = N_Qualified_Expression
5401 or else Nkind (Func_Call) = N_Unchecked_Type_Conversion
5403 Func_Call := Expression (Func_Call);
5406 Loc := Sloc (Function_Call);
5408 if Is_Entity_Name (Name (Func_Call)) then
5409 Function_Id := Entity (Name (Func_Call));
5411 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5412 Function_Id := Etype (Name (Func_Call));
5415 raise Program_Error;
5418 Result_Subt := Etype (Function_Id);
5420 -- In the constrained case, add an implicit actual to the function call
5421 -- that provides access to the declared object. An unchecked conversion
5422 -- to the (specific) result type of the function is inserted to handle
5423 -- the case where the object is declared with a class-wide type.
5425 if Is_Constrained (Underlying_Type (Result_Subt)) then
5427 Make_Unchecked_Type_Conversion (Loc,
5428 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5429 Expression => New_Reference_To (Obj_Def_Id, Loc));
5431 -- When the function has a controlling result, an allocation-form
5432 -- parameter must be passed indicating that the caller is allocating
5433 -- the result object. This is needed because such a function can be
5434 -- called as a dispatching operation and must be treated similarly
5435 -- to functions with unconstrained result subtypes.
5437 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5438 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5440 -- If the function's result subtype is unconstrained and the object is
5441 -- a return object of an enclosing build-in-place function, then the
5442 -- implicit build-in-place parameters of the enclosing function must be
5443 -- passed along to the called function.
5445 elsif Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement then
5446 Pass_Caller_Acc := True;
5448 Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
5450 -- If the enclosing function has a constrained result type, then
5451 -- caller allocation will be used.
5453 if Is_Constrained (Etype (Enclosing_Func)) then
5454 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5455 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5457 -- Otherwise, when the enclosing function has an unconstrained result
5458 -- type, the BIP_Alloc_Form formal of the enclosing function must be
5459 -- passed along to the callee.
5462 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5467 (Build_In_Place_Formal (Enclosing_Func, BIP_Alloc_Form),
5471 -- Retrieve the BIPacc formal from the enclosing function and convert
5472 -- it to the access type of the callee's BIP_Object_Access formal.
5475 Make_Unchecked_Type_Conversion (Loc,
5479 (Build_In_Place_Formal (Function_Id, BIP_Object_Access)),
5483 (Build_In_Place_Formal (Enclosing_Func, BIP_Object_Access),
5486 -- In other unconstrained cases, pass an indication to do the allocation
5487 -- on the secondary stack and set Caller_Object to Empty so that a null
5488 -- value will be passed for the caller's object address. A transient
5489 -- scope is established to ensure eventual cleanup of the result.
5492 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5495 Alloc_Form => Secondary_Stack);
5496 Caller_Object := Empty;
5498 Establish_Transient_Scope (Object_Decl, Sec_Stack => True);
5501 Add_Final_List_Actual_To_Build_In_Place_Call
5502 (Func_Call, Function_Id, Acc_Type => Empty);
5504 if Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement
5505 and then Has_Task (Result_Subt)
5507 Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
5509 -- Here we're passing along the master that was passed in to this
5512 Add_Task_Actuals_To_Build_In_Place_Call
5513 (Func_Call, Function_Id,
5516 (Build_In_Place_Formal (Enclosing_Func, BIP_Master), Loc));
5519 Add_Task_Actuals_To_Build_In_Place_Call
5520 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5523 Add_Access_Actual_To_Build_In_Place_Call
5524 (Func_Call, Function_Id, Caller_Object, Is_Access => Pass_Caller_Acc);
5526 -- Create an access type designating the function's result subtype
5529 Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
5532 Make_Full_Type_Declaration (Loc,
5533 Defining_Identifier => Ref_Type,
5535 Make_Access_To_Object_Definition (Loc,
5536 All_Present => True,
5537 Subtype_Indication =>
5538 New_Reference_To (Result_Subt, Loc)));
5540 -- The access type and its accompanying object must be inserted after
5541 -- the object declaration in the constrained case, so that the function
5542 -- call can be passed access to the object. In the unconstrained case,
5543 -- the access type and object must be inserted before the object, since
5544 -- the object declaration is rewritten to be a renaming of a dereference
5545 -- of the access object.
5547 if Is_Constrained (Underlying_Type (Result_Subt)) then
5548 Insert_After_And_Analyze (Object_Decl, Ptr_Typ_Decl);
5550 Insert_Before_And_Analyze (Object_Decl, Ptr_Typ_Decl);
5553 -- Finally, create an access object initialized to a reference to the
5557 Make_Defining_Identifier (Loc,
5558 Chars => New_Internal_Name ('R'));
5559 Set_Etype (Def_Id, Ref_Type);
5562 Make_Reference (Loc,
5563 Prefix => Relocate_Node (Func_Call));
5565 Insert_After_And_Analyze (Ptr_Typ_Decl,
5566 Make_Object_Declaration (Loc,
5567 Defining_Identifier => Def_Id,
5568 Object_Definition => New_Reference_To (Ref_Type, Loc),
5569 Expression => New_Expr));
5571 if Is_Constrained (Underlying_Type (Result_Subt)) then
5572 Set_Expression (Object_Decl, Empty);
5573 Set_No_Initialization (Object_Decl);
5575 -- In case of an unconstrained result subtype, rewrite the object
5576 -- declaration as an object renaming where the renamed object is a
5577 -- dereference of <function_Call>'reference:
5579 -- Obj : Subt renames <function_call>'Ref.all;
5583 Make_Explicit_Dereference (Loc,
5584 Prefix => New_Reference_To (Def_Id, Loc));
5586 Rewrite (Object_Decl,
5587 Make_Object_Renaming_Declaration (Loc,
5588 Defining_Identifier => Make_Defining_Identifier (Loc,
5589 New_Internal_Name ('D')),
5590 Access_Definition => Empty,
5591 Subtype_Mark => New_Occurrence_Of (Result_Subt, Loc),
5592 Name => Call_Deref));
5594 Set_Renamed_Object (Defining_Identifier (Object_Decl), Call_Deref);
5596 Analyze (Object_Decl);
5598 -- Replace the internal identifier of the renaming declaration's
5599 -- entity with identifier of the original object entity. We also have
5600 -- to exchange the entities containing their defining identifiers to
5601 -- ensure the correct replacement of the object declaration by the
5602 -- object renaming declaration to avoid homograph conflicts (since
5603 -- the object declaration's defining identifier was already entered
5604 -- in current scope).
5606 Set_Chars (Defining_Identifier (Object_Decl), Chars (Obj_Def_Id));
5607 Exchange_Entities (Defining_Identifier (Object_Decl), Obj_Def_Id);
5610 -- If the object entity has a class-wide Etype, then we need to change
5611 -- it to the result subtype of the function call, because otherwise the
5612 -- object will be class-wide without an explicit intialization and won't
5613 -- be allocated properly by the back end. It seems unclean to make such
5614 -- a revision to the type at this point, and we should try to improve
5615 -- this treatment when build-in-place functions with class-wide results
5616 -- are implemented. ???
5618 if Is_Class_Wide_Type (Etype (Defining_Identifier (Object_Decl))) then
5619 Set_Etype (Defining_Identifier (Object_Decl), Result_Subt);
5621 end Make_Build_In_Place_Call_In_Object_Declaration;