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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Elists; use Elists;
33 with Exp_Atag; use Exp_Atag;
34 with Exp_Ch2; use Exp_Ch2;
35 with Exp_Ch3; use Exp_Ch3;
36 with Exp_Ch7; use Exp_Ch7;
37 with Exp_Ch9; use Exp_Ch9;
38 with Exp_Dbug; use Exp_Dbug;
39 with Exp_Disp; use Exp_Disp;
40 with Exp_Dist; use Exp_Dist;
41 with Exp_Intr; use Exp_Intr;
42 with Exp_Pakd; use Exp_Pakd;
43 with Exp_Tss; use Exp_Tss;
44 with Exp_Util; use Exp_Util;
45 with Fname; use Fname;
46 with Freeze; use Freeze;
47 with Inline; use Inline;
49 with Namet; use Namet;
50 with Nlists; use Nlists;
51 with Nmake; use Nmake;
53 with Restrict; use Restrict;
54 with Rident; use Rident;
55 with Rtsfind; use Rtsfind;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Ch12; use Sem_Ch12;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Eval; use Sem_Eval;
62 with Sem_Disp; use Sem_Disp;
63 with Sem_Dist; use Sem_Dist;
64 with Sem_Mech; use Sem_Mech;
65 with Sem_Res; use Sem_Res;
66 with Sem_Util; use Sem_Util;
67 with Sinfo; use Sinfo;
68 with Snames; use Snames;
69 with Stand; use Stand;
70 with Targparm; use Targparm;
71 with Tbuild; use Tbuild;
72 with Uintp; use Uintp;
73 with Validsw; use Validsw;
75 package body Exp_Ch6 is
77 -----------------------
78 -- Local Subprograms --
79 -----------------------
81 procedure Add_Access_Actual_To_Build_In_Place_Call
82 (Function_Call : Node_Id;
83 Function_Id : Entity_Id;
84 Return_Object : Node_Id;
85 Is_Access : Boolean := False);
86 -- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
87 -- object name given by Return_Object and add the attribute to the end of
88 -- the actual parameter list associated with the build-in-place function
89 -- call denoted by Function_Call. However, if Is_Access is True, then
90 -- Return_Object is already an access expression, in which case it's passed
91 -- along directly to the build-in-place function. Finally, if Return_Object
92 -- is empty, then pass a null literal as the actual.
94 procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
95 (Function_Call : Node_Id;
96 Function_Id : Entity_Id;
97 Alloc_Form : BIP_Allocation_Form := Unspecified;
98 Alloc_Form_Exp : Node_Id := Empty);
99 -- Ada 2005 (AI-318-02): Add an actual indicating the form of allocation,
100 -- if any, to be done by a build-in-place function. If Alloc_Form_Exp is
101 -- present, then use it, otherwise pass a literal corresponding to the
102 -- Alloc_Form parameter (which must not be Unspecified in that case).
104 procedure Add_Extra_Actual_To_Call
105 (Subprogram_Call : Node_Id;
106 Extra_Formal : Entity_Id;
107 Extra_Actual : Node_Id);
108 -- Adds Extra_Actual as a named parameter association for the formal
109 -- Extra_Formal in Subprogram_Call.
111 procedure Add_Final_List_Actual_To_Build_In_Place_Call
112 (Function_Call : Node_Id;
113 Function_Id : Entity_Id;
114 Acc_Type : Entity_Id);
115 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type has
116 -- controlled parts, add an actual parameter that is a pointer to
117 -- appropriate finalization list. The finalization list is that of the
118 -- current scope, except for "new Acc'(F(...))" in which case it's the
119 -- finalization list of the access type returned by the allocator. Acc_Type
120 -- is that type in the allocator case; Empty otherwise.
122 procedure Add_Task_Actuals_To_Build_In_Place_Call
123 (Function_Call : Node_Id;
124 Function_Id : Entity_Id;
125 Master_Actual : Node_Id);
126 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
127 -- contains tasks, add two actual parameters: the master, and a pointer to
128 -- the caller's activation chain. Master_Actual is the actual parameter
129 -- expression to pass for the master. In most cases, this is the current
130 -- master (_master). The two exceptions are: If the function call is the
131 -- initialization expression for an allocator, we pass the master of the
132 -- access type. If the function call is the initialization expression for
133 -- a return object, we pass along the master passed in by the caller. The
134 -- activation chain to pass is always the local one.
136 procedure Check_Overriding_Operation (Subp : Entity_Id);
137 -- Subp is a dispatching operation. Check whether it may override an
138 -- inherited private operation, in which case its DT entry is that of
139 -- the hidden operation, not the one it may have received earlier.
140 -- This must be done before emitting the code to set the corresponding
141 -- DT to the address of the subprogram. The actual placement of Subp in
142 -- the proper place in the list of primitive operations is done in
143 -- Declare_Inherited_Private_Subprograms, which also has to deal with
144 -- implicit operations. This duplication is unavoidable for now???
146 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
147 -- This procedure is called only if the subprogram body N, whose spec
148 -- has the given entity Spec, contains a parameterless recursive call.
149 -- It attempts to generate runtime code to detect if this a case of
150 -- infinite recursion.
152 -- The body is scanned to determine dependencies. If the only external
153 -- dependencies are on a small set of scalar variables, then the values
154 -- of these variables are captured on entry to the subprogram, and if
155 -- the values are not changed for the call, we know immediately that
156 -- we have an infinite recursion.
158 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id);
159 -- For each actual of an in-out or out parameter which is a numeric
160 -- (view) conversion of the form T (A), where A denotes a variable,
161 -- we insert the declaration:
163 -- Temp : T[ := T (A)];
165 -- prior to the call. Then we replace the actual with a reference to Temp,
166 -- and append the assignment:
168 -- A := TypeA (Temp);
170 -- after the call. Here TypeA is the actual type of variable A.
171 -- For out parameters, the initial declaration has no expression.
172 -- If A is not an entity name, we generate instead:
174 -- Var : TypeA renames A;
175 -- Temp : T := Var; -- omitting expression for out parameter.
177 -- Var := TypeA (Temp);
179 -- For other in-out parameters, we emit the required constraint checks
180 -- before and/or after the call.
182 -- For all parameter modes, actuals that denote components and slices
183 -- of packed arrays are expanded into suitable temporaries.
185 -- For non-scalar objects that are possibly unaligned, add call by copy
186 -- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
188 procedure Expand_Inlined_Call
191 Orig_Subp : Entity_Id);
192 -- If called subprogram can be inlined by the front-end, retrieve the
193 -- analyzed body, replace formals with actuals and expand call in place.
194 -- Generate thunks for actuals that are expressions, and insert the
195 -- corresponding constant declarations before the call. If the original
196 -- call is to a derived operation, the return type is the one of the
197 -- derived operation, but the body is that of the original, so return
198 -- expressions in the body must be converted to the desired type (which
199 -- is simply not noted in the tree without inline expansion).
201 function Expand_Protected_Object_Reference
203 Scop : Entity_Id) return Node_Id;
205 procedure Expand_Protected_Subprogram_Call
209 -- A call to a protected subprogram within the protected object may appear
210 -- as a regular call. The list of actuals must be expanded to contain a
211 -- reference to the object itself, and the call becomes a call to the
212 -- corresponding protected subprogram.
214 ----------------------------------------------
215 -- Add_Access_Actual_To_Build_In_Place_Call --
216 ----------------------------------------------
218 procedure Add_Access_Actual_To_Build_In_Place_Call
219 (Function_Call : Node_Id;
220 Function_Id : Entity_Id;
221 Return_Object : Node_Id;
222 Is_Access : Boolean := False)
224 Loc : constant Source_Ptr := Sloc (Function_Call);
225 Obj_Address : Node_Id;
226 Obj_Acc_Formal : Entity_Id;
229 -- Locate the implicit access parameter in the called function
231 Obj_Acc_Formal := Build_In_Place_Formal (Function_Id, BIP_Object_Access);
233 -- If no return object is provided, then pass null
235 if not Present (Return_Object) then
236 Obj_Address := Make_Null (Loc);
237 Set_Parent (Obj_Address, Function_Call);
239 -- If Return_Object is already an expression of an access type, then use
240 -- it directly, since it must be an access value denoting the return
241 -- object, and couldn't possibly be the return object itself.
244 Obj_Address := Return_Object;
245 Set_Parent (Obj_Address, Function_Call);
247 -- Apply Unrestricted_Access to caller's return object
251 Make_Attribute_Reference (Loc,
252 Prefix => Return_Object,
253 Attribute_Name => Name_Unrestricted_Access);
255 Set_Parent (Return_Object, Obj_Address);
256 Set_Parent (Obj_Address, Function_Call);
259 Analyze_And_Resolve (Obj_Address, Etype (Obj_Acc_Formal));
261 -- Build the parameter association for the new actual and add it to the
262 -- end of the function's actuals.
264 Add_Extra_Actual_To_Call (Function_Call, Obj_Acc_Formal, Obj_Address);
265 end Add_Access_Actual_To_Build_In_Place_Call;
267 --------------------------------------------------
268 -- Add_Alloc_Form_Actual_To_Build_In_Place_Call --
269 --------------------------------------------------
271 procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
272 (Function_Call : Node_Id;
273 Function_Id : Entity_Id;
274 Alloc_Form : BIP_Allocation_Form := Unspecified;
275 Alloc_Form_Exp : Node_Id := Empty)
277 Loc : constant Source_Ptr := Sloc (Function_Call);
278 Alloc_Form_Actual : Node_Id;
279 Alloc_Form_Formal : Node_Id;
282 -- The allocation form generally doesn't need to be passed in the case
283 -- of a constrained result subtype, since normally the caller performs
284 -- the allocation in that case. However this formal is still needed in
285 -- the case where the function has a tagged result, because generally
286 -- such functions can be called in a dispatching context and such calls
287 -- must be handled like calls to class-wide functions.
289 if Is_Constrained (Underlying_Type (Etype (Function_Id)))
290 and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
295 -- Locate the implicit allocation form parameter in the called function.
296 -- Maybe it would be better for each implicit formal of a build-in-place
297 -- function to have a flag or a Uint attribute to identify it. ???
299 Alloc_Form_Formal := Build_In_Place_Formal (Function_Id, BIP_Alloc_Form);
301 if Present (Alloc_Form_Exp) then
302 pragma Assert (Alloc_Form = Unspecified);
304 Alloc_Form_Actual := Alloc_Form_Exp;
307 pragma Assert (Alloc_Form /= Unspecified);
310 Make_Integer_Literal (Loc,
311 Intval => UI_From_Int (BIP_Allocation_Form'Pos (Alloc_Form)));
314 Analyze_And_Resolve (Alloc_Form_Actual, Etype (Alloc_Form_Formal));
316 -- Build the parameter association for the new actual and add it to the
317 -- end of the function's actuals.
319 Add_Extra_Actual_To_Call
320 (Function_Call, Alloc_Form_Formal, Alloc_Form_Actual);
321 end Add_Alloc_Form_Actual_To_Build_In_Place_Call;
323 ------------------------------
324 -- Add_Extra_Actual_To_Call --
325 ------------------------------
327 procedure Add_Extra_Actual_To_Call
328 (Subprogram_Call : Node_Id;
329 Extra_Formal : Entity_Id;
330 Extra_Actual : Node_Id)
332 Loc : constant Source_Ptr := Sloc (Subprogram_Call);
333 Param_Assoc : Node_Id;
337 Make_Parameter_Association (Loc,
338 Selector_Name => New_Occurrence_Of (Extra_Formal, Loc),
339 Explicit_Actual_Parameter => Extra_Actual);
341 Set_Parent (Param_Assoc, Subprogram_Call);
342 Set_Parent (Extra_Actual, Param_Assoc);
344 if Present (Parameter_Associations (Subprogram_Call)) then
345 if Nkind (Last (Parameter_Associations (Subprogram_Call))) =
346 N_Parameter_Association
349 -- Find last named actual, and append
354 L := First_Actual (Subprogram_Call);
355 while Present (L) loop
356 if No (Next_Actual (L)) then
357 Set_Next_Named_Actual (Parent (L), Extra_Actual);
365 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
368 Append (Param_Assoc, To => Parameter_Associations (Subprogram_Call));
371 Set_Parameter_Associations (Subprogram_Call, New_List (Param_Assoc));
372 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
374 end Add_Extra_Actual_To_Call;
376 --------------------------------------------------
377 -- Add_Final_List_Actual_To_Build_In_Place_Call --
378 --------------------------------------------------
380 procedure Add_Final_List_Actual_To_Build_In_Place_Call
381 (Function_Call : Node_Id;
382 Function_Id : Entity_Id;
383 Acc_Type : Entity_Id)
385 Loc : constant Source_Ptr := Sloc (Function_Call);
386 Final_List : Node_Id;
387 Final_List_Actual : Node_Id;
388 Final_List_Formal : Node_Id;
391 -- No such extra parameter is needed if there are no controlled parts.
392 -- The test for Controlled_Type accounts for class-wide results (which
393 -- potentially have controlled parts, even if the root type doesn't),
394 -- and the test for a tagged result type is needed because calls to
395 -- such a function can in general occur in dispatching contexts, which
396 -- must be treated the same as a call to class-wide functions. Both of
397 -- these situations require that a finalization list be passed.
399 if not Controlled_Type (Underlying_Type (Etype (Function_Id)))
400 and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
405 -- Locate implicit finalization list parameter in the called function
407 Final_List_Formal := Build_In_Place_Formal (Function_Id, BIP_Final_List);
409 -- Create the actual which is a pointer to the appropriate finalization
410 -- list. Acc_Type is present if and only if this call is the
411 -- initialization of an allocator. Use the Current_Scope or the Acc_Type
414 if Present (Acc_Type)
415 and then (Ekind (Acc_Type) = E_Anonymous_Access_Type
417 Present (Associated_Final_Chain (Base_Type (Acc_Type))))
419 Final_List := Find_Final_List (Acc_Type);
421 Final_List := Find_Final_List (Current_Scope);
425 Make_Attribute_Reference (Loc,
426 Prefix => Final_List,
427 Attribute_Name => Name_Unrestricted_Access);
429 Analyze_And_Resolve (Final_List_Actual, Etype (Final_List_Formal));
431 -- Build the parameter association for the new actual and add it to the
432 -- end of the function's actuals.
434 Add_Extra_Actual_To_Call
435 (Function_Call, Final_List_Formal, Final_List_Actual);
436 end Add_Final_List_Actual_To_Build_In_Place_Call;
438 ---------------------------------------------
439 -- Add_Task_Actuals_To_Build_In_Place_Call --
440 ---------------------------------------------
442 procedure Add_Task_Actuals_To_Build_In_Place_Call
443 (Function_Call : Node_Id;
444 Function_Id : Entity_Id;
445 Master_Actual : Node_Id)
446 -- Note: Master_Actual can be Empty, but only if there are no tasks
448 Loc : constant Source_Ptr := Sloc (Function_Call);
451 -- No such extra parameters are needed if there are no tasks
453 if not Has_Task (Etype (Function_Id)) then
460 Master_Formal : Node_Id;
462 -- Locate implicit master parameter in the called function
464 Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Master);
466 Analyze_And_Resolve (Master_Actual, Etype (Master_Formal));
468 -- Build the parameter association for the new actual and add it to
469 -- the end of the function's actuals.
471 Add_Extra_Actual_To_Call
472 (Function_Call, Master_Formal, Master_Actual);
475 -- The activation chain
478 Activation_Chain_Actual : Node_Id;
479 Activation_Chain_Formal : Node_Id;
481 -- Locate implicit activation chain parameter in the called function
483 Activation_Chain_Formal := Build_In_Place_Formal
484 (Function_Id, BIP_Activation_Chain);
486 -- Create the actual which is a pointer to the current activation
489 Activation_Chain_Actual :=
490 Make_Attribute_Reference (Loc,
491 Prefix => Make_Identifier (Loc, Name_uChain),
492 Attribute_Name => Name_Unrestricted_Access);
495 (Activation_Chain_Actual, Etype (Activation_Chain_Formal));
497 -- Build the parameter association for the new actual and add it to
498 -- the end of the function's actuals.
500 Add_Extra_Actual_To_Call
501 (Function_Call, Activation_Chain_Formal, Activation_Chain_Actual);
503 end Add_Task_Actuals_To_Build_In_Place_Call;
505 -----------------------
506 -- BIP_Formal_Suffix --
507 -----------------------
509 function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String is
512 when BIP_Alloc_Form =>
514 when BIP_Final_List =>
515 return "BIPfinallist";
518 when BIP_Activation_Chain =>
519 return "BIPactivationchain";
520 when BIP_Object_Access =>
523 end BIP_Formal_Suffix;
525 ---------------------------
526 -- Build_In_Place_Formal --
527 ---------------------------
529 function Build_In_Place_Formal
531 Kind : BIP_Formal_Kind) return Entity_Id
533 Extra_Formal : Entity_Id := Extra_Formals (Func);
536 -- Maybe it would be better for each implicit formal of a build-in-place
537 -- function to have a flag or a Uint attribute to identify it. ???
541 Chars (Extra_Formal) =
542 New_External_Name (Chars (Func), BIP_Formal_Suffix (Kind));
543 Next_Formal_With_Extras (Extra_Formal);
544 pragma Assert (Present (Extra_Formal));
548 end Build_In_Place_Formal;
550 --------------------------------
551 -- Check_Overriding_Operation --
552 --------------------------------
554 procedure Check_Overriding_Operation (Subp : Entity_Id) is
555 Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
556 Op_List : constant Elist_Id := Primitive_Operations (Typ);
562 if Is_Derived_Type (Typ)
563 and then not Is_Private_Type (Typ)
564 and then In_Open_Scopes (Scope (Etype (Typ)))
565 and then Typ = Base_Type (Typ)
567 -- Subp overrides an inherited private operation if there is an
568 -- inherited operation with a different name than Subp (see
569 -- Derive_Subprogram) whose Alias is a hidden subprogram with the
570 -- same name as Subp.
572 Op_Elmt := First_Elmt (Op_List);
573 while Present (Op_Elmt) loop
574 Prim_Op := Node (Op_Elmt);
575 Par_Op := Alias (Prim_Op);
578 and then not Comes_From_Source (Prim_Op)
579 and then Chars (Prim_Op) /= Chars (Par_Op)
580 and then Chars (Par_Op) = Chars (Subp)
581 and then Is_Hidden (Par_Op)
582 and then Type_Conformant (Prim_Op, Subp)
584 Set_DT_Position (Subp, DT_Position (Prim_Op));
590 end Check_Overriding_Operation;
592 -------------------------------
593 -- Detect_Infinite_Recursion --
594 -------------------------------
596 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
597 Loc : constant Source_Ptr := Sloc (N);
599 Var_List : constant Elist_Id := New_Elmt_List;
600 -- List of globals referenced by body of procedure
602 Call_List : constant Elist_Id := New_Elmt_List;
603 -- List of recursive calls in body of procedure
605 Shad_List : constant Elist_Id := New_Elmt_List;
606 -- List of entity id's for entities created to capture the value of
607 -- referenced globals on entry to the procedure.
609 Scop : constant Uint := Scope_Depth (Spec);
610 -- This is used to record the scope depth of the current procedure, so
611 -- that we can identify global references.
613 Max_Vars : constant := 4;
614 -- Do not test more than four global variables
616 Count_Vars : Natural := 0;
617 -- Count variables found so far
629 function Process (Nod : Node_Id) return Traverse_Result;
630 -- Function to traverse the subprogram body (using Traverse_Func)
636 function Process (Nod : Node_Id) return Traverse_Result is
640 if Nkind (Nod) = N_Procedure_Call_Statement then
642 -- Case of one of the detected recursive calls
644 if Is_Entity_Name (Name (Nod))
645 and then Has_Recursive_Call (Entity (Name (Nod)))
646 and then Entity (Name (Nod)) = Spec
648 Append_Elmt (Nod, Call_List);
651 -- Any other procedure call may have side effects
657 -- A call to a pure function can always be ignored
659 elsif Nkind (Nod) = N_Function_Call
660 and then Is_Entity_Name (Name (Nod))
661 and then Is_Pure (Entity (Name (Nod)))
665 -- Case of an identifier reference
667 elsif Nkind (Nod) = N_Identifier then
670 -- If no entity, then ignore the reference
672 -- Not clear why this can happen. To investigate, remove this
673 -- test and look at the crash that occurs here in 3401-004 ???
678 -- Ignore entities with no Scope, again not clear how this
679 -- can happen, to investigate, look at 4108-008 ???
681 elsif No (Scope (Ent)) then
684 -- Ignore the reference if not to a more global object
686 elsif Scope_Depth (Scope (Ent)) >= Scop then
689 -- References to types, exceptions and constants are always OK
692 or else Ekind (Ent) = E_Exception
693 or else Ekind (Ent) = E_Constant
697 -- If other than a non-volatile scalar variable, we have some
698 -- kind of global reference (e.g. to a function) that we cannot
699 -- deal with so we forget the attempt.
701 elsif Ekind (Ent) /= E_Variable
702 or else not Is_Scalar_Type (Etype (Ent))
703 or else Treat_As_Volatile (Ent)
707 -- Otherwise we have a reference to a global scalar
710 -- Loop through global entities already detected
712 Elm := First_Elmt (Var_List);
714 -- If not detected before, record this new global reference
717 Count_Vars := Count_Vars + 1;
719 if Count_Vars <= Max_Vars then
720 Append_Elmt (Entity (Nod), Var_List);
727 -- If recorded before, ignore
729 elsif Node (Elm) = Entity (Nod) then
732 -- Otherwise keep looking
742 -- For all other node kinds, recursively visit syntactic children
749 function Traverse_Body is new Traverse_Func (Process);
751 -- Start of processing for Detect_Infinite_Recursion
754 -- Do not attempt detection in No_Implicit_Conditional mode, since we
755 -- won't be able to generate the code to handle the recursion in any
758 if Restriction_Active (No_Implicit_Conditionals) then
762 -- Otherwise do traversal and quit if we get abandon signal
764 if Traverse_Body (N) = Abandon then
767 -- We must have a call, since Has_Recursive_Call was set. If not just
768 -- ignore (this is only an error check, so if we have a funny situation,
769 -- due to bugs or errors, we do not want to bomb!)
771 elsif Is_Empty_Elmt_List (Call_List) then
775 -- Here is the case where we detect recursion at compile time
777 -- Push our current scope for analyzing the declarations and code that
778 -- we will insert for the checking.
782 -- This loop builds temporary variables for each of the referenced
783 -- globals, so that at the end of the loop the list Shad_List contains
784 -- these temporaries in one-to-one correspondence with the elements in
788 Elm := First_Elmt (Var_List);
789 while Present (Elm) loop
792 Make_Defining_Identifier (Loc,
793 Chars => New_Internal_Name ('S'));
794 Append_Elmt (Ent, Shad_List);
796 -- Insert a declaration for this temporary at the start of the
797 -- declarations for the procedure. The temporaries are declared as
798 -- constant objects initialized to the current values of the
799 -- corresponding temporaries.
802 Make_Object_Declaration (Loc,
803 Defining_Identifier => Ent,
804 Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
805 Constant_Present => True,
806 Expression => New_Occurrence_Of (Var, Loc));
809 Prepend (Decl, Declarations (N));
811 Insert_After (Last, Decl);
819 -- Loop through calls
821 Call := First_Elmt (Call_List);
822 while Present (Call) loop
824 -- Build a predicate expression of the form
827 -- and then global1 = temp1
828 -- and then global2 = temp2
831 -- This predicate determines if any of the global values
832 -- referenced by the procedure have changed since the
833 -- current call, if not an infinite recursion is assured.
835 Test := New_Occurrence_Of (Standard_True, Loc);
837 Elm1 := First_Elmt (Var_List);
838 Elm2 := First_Elmt (Shad_List);
839 while Present (Elm1) loop
845 Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
846 Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
852 -- Now we replace the call with the sequence
854 -- if no-changes (see above) then
855 -- raise Storage_Error;
860 Rewrite (Node (Call),
861 Make_If_Statement (Loc,
863 Then_Statements => New_List (
864 Make_Raise_Storage_Error (Loc,
865 Reason => SE_Infinite_Recursion)),
867 Else_Statements => New_List (
868 Relocate_Node (Node (Call)))));
870 Analyze (Node (Call));
875 -- Remove temporary scope stack entry used for analysis
878 end Detect_Infinite_Recursion;
884 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id) is
885 Loc : constant Source_Ptr := Sloc (N);
890 E_Formal : Entity_Id;
892 procedure Add_Call_By_Copy_Code;
893 -- For cases where the parameter must be passed by copy, this routine
894 -- generates a temporary variable into which the actual is copied and
895 -- then passes this as the parameter. For an OUT or IN OUT parameter,
896 -- an assignment is also generated to copy the result back. The call
897 -- also takes care of any constraint checks required for the type
898 -- conversion case (on both the way in and the way out).
900 procedure Add_Simple_Call_By_Copy_Code;
901 -- This is similar to the above, but is used in cases where we know
902 -- that all that is needed is to simply create a temporary and copy
903 -- the value in and out of the temporary.
905 procedure Check_Fortran_Logical;
906 -- A value of type Logical that is passed through a formal parameter
907 -- must be normalized because .TRUE. usually does not have the same
908 -- representation as True. We assume that .FALSE. = False = 0.
909 -- What about functions that return a logical type ???
911 function Is_Legal_Copy return Boolean;
912 -- Check that an actual can be copied before generating the temporary
913 -- to be used in the call. If the actual is of a by_reference type then
914 -- the program is illegal (this can only happen in the presence of
915 -- rep. clauses that force an incorrect alignment). If the formal is
916 -- a by_reference parameter imposed by a DEC pragma, emit a warning to
917 -- the effect that this might lead to unaligned arguments.
919 function Make_Var (Actual : Node_Id) return Entity_Id;
920 -- Returns an entity that refers to the given actual parameter,
921 -- Actual (not including any type conversion). If Actual is an
922 -- entity name, then this entity is returned unchanged, otherwise
923 -- a renaming is created to provide an entity for the actual.
925 procedure Reset_Packed_Prefix;
926 -- The expansion of a packed array component reference is delayed in
927 -- the context of a call. Now we need to complete the expansion, so we
928 -- unmark the analyzed bits in all prefixes.
930 ---------------------------
931 -- Add_Call_By_Copy_Code --
932 ---------------------------
934 procedure Add_Call_By_Copy_Code is
940 F_Typ : constant Entity_Id := Etype (Formal);
945 if not Is_Legal_Copy then
950 Make_Defining_Identifier (Loc,
951 Chars => New_Internal_Name ('T'));
953 -- Use formal type for temp, unless formal type is an unconstrained
954 -- array, in which case we don't have to worry about bounds checks,
955 -- and we use the actual type, since that has appropriate bounds.
957 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
958 Indic := New_Occurrence_Of (Etype (Actual), Loc);
960 Indic := New_Occurrence_Of (Etype (Formal), Loc);
963 if Nkind (Actual) = N_Type_Conversion then
964 V_Typ := Etype (Expression (Actual));
966 -- If the formal is an (in-)out parameter, capture the name
967 -- of the variable in order to build the post-call assignment.
969 Var := Make_Var (Expression (Actual));
971 Crep := not Same_Representation
972 (F_Typ, Etype (Expression (Actual)));
975 V_Typ := Etype (Actual);
976 Var := Make_Var (Actual);
980 -- Setup initialization for case of in out parameter, or an out
981 -- parameter where the formal is an unconstrained array (in the
982 -- latter case, we have to pass in an object with bounds).
984 -- If this is an out parameter, the initial copy is wasteful, so as
985 -- an optimization for the one-dimensional case we extract the
986 -- bounds of the actual and build an uninitialized temporary of the
989 if Ekind (Formal) = E_In_Out_Parameter
990 or else (Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ))
992 if Nkind (Actual) = N_Type_Conversion then
993 if Conversion_OK (Actual) then
994 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
996 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
999 elsif Ekind (Formal) = E_Out_Parameter
1000 and then Is_Array_Type (F_Typ)
1001 and then Number_Dimensions (F_Typ) = 1
1002 and then not Has_Non_Null_Base_Init_Proc (F_Typ)
1004 -- Actual is a one-dimensional array or slice, and the type
1005 -- requires no initialization. Create a temporary of the
1006 -- right size, but do not copy actual into it (optimization).
1010 Make_Subtype_Indication (Loc,
1012 New_Occurrence_Of (F_Typ, Loc),
1014 Make_Index_Or_Discriminant_Constraint (Loc,
1015 Constraints => New_List (
1018 Make_Attribute_Reference (Loc,
1019 Prefix => New_Occurrence_Of (Var, Loc),
1020 Attribute_name => Name_First),
1022 Make_Attribute_Reference (Loc,
1023 Prefix => New_Occurrence_Of (Var, Loc),
1024 Attribute_Name => Name_Last)))));
1027 Init := New_Occurrence_Of (Var, Loc);
1030 -- An initialization is created for packed conversions as
1031 -- actuals for out parameters to enable Make_Object_Declaration
1032 -- to determine the proper subtype for N_Node. Note that this
1033 -- is wasteful because the extra copying on the call side is
1034 -- not required for such out parameters. ???
1036 elsif Ekind (Formal) = E_Out_Parameter
1037 and then Nkind (Actual) = N_Type_Conversion
1038 and then (Is_Bit_Packed_Array (F_Typ)
1040 Is_Bit_Packed_Array (Etype (Expression (Actual))))
1042 if Conversion_OK (Actual) then
1043 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1045 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1048 elsif Ekind (Formal) = E_In_Parameter then
1050 -- Handle the case in which the actual is a type conversion
1052 if Nkind (Actual) = N_Type_Conversion then
1053 if Conversion_OK (Actual) then
1054 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1056 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1059 Init := New_Occurrence_Of (Var, Loc);
1067 Make_Object_Declaration (Loc,
1068 Defining_Identifier => Temp,
1069 Object_Definition => Indic,
1070 Expression => Init);
1071 Set_Assignment_OK (N_Node);
1072 Insert_Action (N, N_Node);
1074 -- Now, normally the deal here is that we use the defining
1075 -- identifier created by that object declaration. There is
1076 -- one exception to this. In the change of representation case
1077 -- the above declaration will end up looking like:
1079 -- temp : type := identifier;
1081 -- And in this case we might as well use the identifier directly
1082 -- and eliminate the temporary. Note that the analysis of the
1083 -- declaration was not a waste of time in that case, since it is
1084 -- what generated the necessary change of representation code. If
1085 -- the change of representation introduced additional code, as in
1086 -- a fixed-integer conversion, the expression is not an identifier
1087 -- and must be kept.
1090 and then Present (Expression (N_Node))
1091 and then Is_Entity_Name (Expression (N_Node))
1093 Temp := Entity (Expression (N_Node));
1094 Rewrite (N_Node, Make_Null_Statement (Loc));
1097 -- For IN parameter, all we do is to replace the actual
1099 if Ekind (Formal) = E_In_Parameter then
1100 Rewrite (Actual, New_Reference_To (Temp, Loc));
1103 -- Processing for OUT or IN OUT parameter
1106 -- Kill current value indications for the temporary variable we
1107 -- created, since we just passed it as an OUT parameter.
1109 Kill_Current_Values (Temp);
1111 -- If type conversion, use reverse conversion on exit
1113 if Nkind (Actual) = N_Type_Conversion then
1114 if Conversion_OK (Actual) then
1115 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1117 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1120 Expr := New_Occurrence_Of (Temp, Loc);
1123 Rewrite (Actual, New_Reference_To (Temp, Loc));
1126 Append_To (Post_Call,
1127 Make_Assignment_Statement (Loc,
1128 Name => New_Occurrence_Of (Var, Loc),
1129 Expression => Expr));
1131 Set_Assignment_OK (Name (Last (Post_Call)));
1133 end Add_Call_By_Copy_Code;
1135 ----------------------------------
1136 -- Add_Simple_Call_By_Copy_Code --
1137 ----------------------------------
1139 procedure Add_Simple_Call_By_Copy_Code is
1147 F_Typ : constant Entity_Id := Etype (Formal);
1150 if not Is_Legal_Copy then
1154 -- Use formal type for temp, unless formal type is an unconstrained
1155 -- array, in which case we don't have to worry about bounds checks,
1156 -- and we use the actual type, since that has appropriate bounds.
1158 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
1159 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1161 Indic := New_Occurrence_Of (Etype (Formal), Loc);
1164 -- Prepare to generate code
1166 Reset_Packed_Prefix;
1169 Make_Defining_Identifier (Loc,
1170 Chars => New_Internal_Name ('T'));
1171 Incod := Relocate_Node (Actual);
1172 Outcod := New_Copy_Tree (Incod);
1174 -- Generate declaration of temporary variable, initializing it
1175 -- with the input parameter unless we have an OUT formal or
1176 -- this is an initialization call.
1178 -- If the formal is an out parameter with discriminants, the
1179 -- discriminants must be captured even if the rest of the object
1180 -- is in principle uninitialized, because the discriminants may
1181 -- be read by the called subprogram.
1183 if Ekind (Formal) = E_Out_Parameter then
1186 if Has_Discriminants (Etype (Formal)) then
1187 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1190 elsif Inside_Init_Proc then
1192 -- Could use a comment here to match comment below ???
1194 if Nkind (Actual) /= N_Selected_Component
1196 not Has_Discriminant_Dependent_Constraint
1197 (Entity (Selector_Name (Actual)))
1201 -- Otherwise, keep the component in order to generate the proper
1202 -- actual subtype, that depends on enclosing discriminants.
1210 Make_Object_Declaration (Loc,
1211 Defining_Identifier => Temp,
1212 Object_Definition => Indic,
1213 Expression => Incod);
1218 -- If the call is to initialize a component of a composite type,
1219 -- and the component does not depend on discriminants, use the
1220 -- actual type of the component. This is required in case the
1221 -- component is constrained, because in general the formal of the
1222 -- initialization procedure will be unconstrained. Note that if
1223 -- the component being initialized is constrained by an enclosing
1224 -- discriminant, the presence of the initialization in the
1225 -- declaration will generate an expression for the actual subtype.
1227 Set_No_Initialization (Decl);
1228 Set_Object_Definition (Decl,
1229 New_Occurrence_Of (Etype (Actual), Loc));
1232 Insert_Action (N, Decl);
1234 -- The actual is simply a reference to the temporary
1236 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
1238 -- Generate copy out if OUT or IN OUT parameter
1240 if Ekind (Formal) /= E_In_Parameter then
1242 Rhs := New_Occurrence_Of (Temp, Loc);
1244 -- Deal with conversion
1246 if Nkind (Lhs) = N_Type_Conversion then
1247 Lhs := Expression (Lhs);
1248 Rhs := Convert_To (Etype (Actual), Rhs);
1251 Append_To (Post_Call,
1252 Make_Assignment_Statement (Loc,
1254 Expression => Rhs));
1255 Set_Assignment_OK (Name (Last (Post_Call)));
1257 end Add_Simple_Call_By_Copy_Code;
1259 ---------------------------
1260 -- Check_Fortran_Logical --
1261 ---------------------------
1263 procedure Check_Fortran_Logical is
1264 Logical : constant Entity_Id := Etype (Formal);
1267 -- Note: this is very incomplete, e.g. it does not handle arrays
1268 -- of logical values. This is really not the right approach at all???)
1271 if Convention (Subp) = Convention_Fortran
1272 and then Root_Type (Etype (Formal)) = Standard_Boolean
1273 and then Ekind (Formal) /= E_In_Parameter
1275 Var := Make_Var (Actual);
1276 Append_To (Post_Call,
1277 Make_Assignment_Statement (Loc,
1278 Name => New_Occurrence_Of (Var, Loc),
1280 Unchecked_Convert_To (
1283 Left_Opnd => New_Occurrence_Of (Var, Loc),
1285 Unchecked_Convert_To (
1287 New_Occurrence_Of (Standard_False, Loc))))));
1289 end Check_Fortran_Logical;
1295 function Is_Legal_Copy return Boolean is
1297 -- An attempt to copy a value of such a type can only occur if
1298 -- representation clauses give the actual a misaligned address.
1300 if Is_By_Reference_Type (Etype (Formal)) then
1302 ("misaligned actual cannot be passed by reference", Actual);
1305 -- For users of Starlet, we assume that the specification of by-
1306 -- reference mechanism is mandatory. This may lead to unaligned
1307 -- objects but at least for DEC legacy code it is known to work.
1308 -- The warning will alert users of this code that a problem may
1311 elsif Mechanism (Formal) = By_Reference
1312 and then Is_Valued_Procedure (Scope (Formal))
1315 ("by_reference actual may be misaligned?", Actual);
1327 function Make_Var (Actual : Node_Id) return Entity_Id is
1331 if Is_Entity_Name (Actual) then
1332 return Entity (Actual);
1336 Make_Defining_Identifier (Loc,
1337 Chars => New_Internal_Name ('T'));
1340 Make_Object_Renaming_Declaration (Loc,
1341 Defining_Identifier => Var,
1343 New_Occurrence_Of (Etype (Actual), Loc),
1344 Name => Relocate_Node (Actual));
1346 Insert_Action (N, N_Node);
1351 -------------------------
1352 -- Reset_Packed_Prefix --
1353 -------------------------
1355 procedure Reset_Packed_Prefix is
1356 Pfx : Node_Id := Actual;
1359 Set_Analyzed (Pfx, False);
1360 exit when Nkind (Pfx) /= N_Selected_Component
1361 and then Nkind (Pfx) /= N_Indexed_Component;
1362 Pfx := Prefix (Pfx);
1364 end Reset_Packed_Prefix;
1366 -- Start of processing for Expand_Actuals
1369 Post_Call := New_List;
1371 Formal := First_Formal (Subp);
1372 Actual := First_Actual (N);
1373 while Present (Formal) loop
1374 E_Formal := Etype (Formal);
1376 if Is_Scalar_Type (E_Formal)
1377 or else Nkind (Actual) = N_Slice
1379 Check_Fortran_Logical;
1383 elsif Ekind (Formal) /= E_Out_Parameter then
1385 -- The unusual case of the current instance of a protected type
1386 -- requires special handling. This can only occur in the context
1387 -- of a call within the body of a protected operation.
1389 if Is_Entity_Name (Actual)
1390 and then Ekind (Entity (Actual)) = E_Protected_Type
1391 and then In_Open_Scopes (Entity (Actual))
1393 if Scope (Subp) /= Entity (Actual) then
1394 Error_Msg_N ("operation outside protected type may not "
1395 & "call back its protected operations?", Actual);
1399 Expand_Protected_Object_Reference (N, Entity (Actual)));
1402 -- Ada 2005 (AI-318-02): If the actual parameter is a call to a
1403 -- build-in-place function, then a temporary return object needs
1404 -- to be created and access to it must be passed to the function.
1405 -- Currently we limit such functions to those with inherently
1406 -- limited result subtypes, but eventually we plan to expand the
1407 -- functions that are treated as build-in-place to include other
1408 -- composite result types.
1410 if Ada_Version >= Ada_05
1411 and then Is_Build_In_Place_Function_Call (Actual)
1413 Make_Build_In_Place_Call_In_Anonymous_Context (Actual);
1416 Apply_Constraint_Check (Actual, E_Formal);
1418 -- Out parameter case. No constraint checks on access type
1421 elsif Is_Access_Type (E_Formal) then
1426 elsif Has_Discriminants (Base_Type (E_Formal))
1427 or else Has_Non_Null_Base_Init_Proc (E_Formal)
1429 Apply_Constraint_Check (Actual, E_Formal);
1434 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
1437 -- Processing for IN-OUT and OUT parameters
1439 if Ekind (Formal) /= E_In_Parameter then
1441 -- For type conversions of arrays, apply length/range checks
1443 if Is_Array_Type (E_Formal)
1444 and then Nkind (Actual) = N_Type_Conversion
1446 if Is_Constrained (E_Formal) then
1447 Apply_Length_Check (Expression (Actual), E_Formal);
1449 Apply_Range_Check (Expression (Actual), E_Formal);
1453 -- If argument is a type conversion for a type that is passed
1454 -- by copy, then we must pass the parameter by copy.
1456 if Nkind (Actual) = N_Type_Conversion
1458 (Is_Numeric_Type (E_Formal)
1459 or else Is_Access_Type (E_Formal)
1460 or else Is_Enumeration_Type (E_Formal)
1461 or else Is_Bit_Packed_Array (Etype (Formal))
1462 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
1464 -- Also pass by copy if change of representation
1466 or else not Same_Representation
1468 Etype (Expression (Actual))))
1470 Add_Call_By_Copy_Code;
1472 -- References to components of bit packed arrays are expanded
1473 -- at this point, rather than at the point of analysis of the
1474 -- actuals, to handle the expansion of the assignment to
1475 -- [in] out parameters.
1477 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1478 Add_Simple_Call_By_Copy_Code;
1480 -- If a non-scalar actual is possibly bit-aligned, we need a copy
1481 -- because the back-end cannot cope with such objects. In other
1482 -- cases where alignment forces a copy, the back-end generates
1483 -- it properly. It should not be generated unconditionally in the
1484 -- front-end because it does not know precisely the alignment
1485 -- requirements of the target, and makes too conservative an
1486 -- estimate, leading to superfluous copies or spurious errors
1487 -- on by-reference parameters.
1489 elsif Nkind (Actual) = N_Selected_Component
1491 Component_May_Be_Bit_Aligned (Entity (Selector_Name (Actual)))
1492 and then not Represented_As_Scalar (Etype (Formal))
1494 Add_Simple_Call_By_Copy_Code;
1496 -- References to slices of bit packed arrays are expanded
1498 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1499 Add_Call_By_Copy_Code;
1501 -- References to possibly unaligned slices of arrays are expanded
1503 elsif Is_Possibly_Unaligned_Slice (Actual) then
1504 Add_Call_By_Copy_Code;
1506 -- Deal with access types where the actual subtype and the
1507 -- formal subtype are not the same, requiring a check.
1509 -- It is necessary to exclude tagged types because of "downward
1510 -- conversion" errors and a strange assertion error in namet
1511 -- from gnatf in bug 1215-001 ???
1513 elsif Is_Access_Type (E_Formal)
1514 and then not Same_Type (E_Formal, Etype (Actual))
1515 and then not Is_Tagged_Type (Designated_Type (E_Formal))
1517 Add_Call_By_Copy_Code;
1519 -- If the actual is not a scalar and is marked for volatile
1520 -- treatment, whereas the formal is not volatile, then pass
1521 -- by copy unless it is a by-reference type.
1523 elsif Is_Entity_Name (Actual)
1524 and then Treat_As_Volatile (Entity (Actual))
1525 and then not Is_By_Reference_Type (Etype (Actual))
1526 and then not Is_Scalar_Type (Etype (Entity (Actual)))
1527 and then not Treat_As_Volatile (E_Formal)
1529 Add_Call_By_Copy_Code;
1531 elsif Nkind (Actual) = N_Indexed_Component
1532 and then Is_Entity_Name (Prefix (Actual))
1533 and then Has_Volatile_Components (Entity (Prefix (Actual)))
1535 Add_Call_By_Copy_Code;
1538 -- Processing for IN parameters
1541 -- For IN parameters is in the packed array case, we expand an
1542 -- indexed component (the circuit in Exp_Ch4 deliberately left
1543 -- indexed components appearing as actuals untouched, so that
1544 -- the special processing above for the OUT and IN OUT cases
1545 -- could be performed. We could make the test in Exp_Ch4 more
1546 -- complex and have it detect the parameter mode, but it is
1547 -- easier simply to handle all cases here.)
1549 if Nkind (Actual) = N_Indexed_Component
1550 and then Is_Packed (Etype (Prefix (Actual)))
1552 Reset_Packed_Prefix;
1553 Expand_Packed_Element_Reference (Actual);
1555 -- If we have a reference to a bit packed array, we copy it,
1556 -- since the actual must be byte aligned.
1558 -- Is this really necessary in all cases???
1560 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1561 Add_Simple_Call_By_Copy_Code;
1563 -- If a non-scalar actual is possibly unaligned, we need a copy
1565 elsif Is_Possibly_Unaligned_Object (Actual)
1566 and then not Represented_As_Scalar (Etype (Formal))
1568 Add_Simple_Call_By_Copy_Code;
1570 -- Similarly, we have to expand slices of packed arrays here
1571 -- because the result must be byte aligned.
1573 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1574 Add_Call_By_Copy_Code;
1576 -- Only processing remaining is to pass by copy if this is a
1577 -- reference to a possibly unaligned slice, since the caller
1578 -- expects an appropriately aligned argument.
1580 elsif Is_Possibly_Unaligned_Slice (Actual) then
1581 Add_Call_By_Copy_Code;
1585 Next_Formal (Formal);
1586 Next_Actual (Actual);
1589 -- Find right place to put post call stuff if it is present
1591 if not Is_Empty_List (Post_Call) then
1593 -- If call is not a list member, it must be the triggering statement
1594 -- of a triggering alternative or an entry call alternative, and we
1595 -- can add the post call stuff to the corresponding statement list.
1597 if not Is_List_Member (N) then
1599 P : constant Node_Id := Parent (N);
1602 pragma Assert (Nkind (P) = N_Triggering_Alternative
1603 or else Nkind (P) = N_Entry_Call_Alternative);
1605 if Is_Non_Empty_List (Statements (P)) then
1606 Insert_List_Before_And_Analyze
1607 (First (Statements (P)), Post_Call);
1609 Set_Statements (P, Post_Call);
1613 -- Otherwise, normal case where N is in a statement sequence,
1614 -- just put the post-call stuff after the call statement.
1617 Insert_Actions_After (N, Post_Call);
1621 -- The call node itself is re-analyzed in Expand_Call
1629 -- This procedure handles expansion of function calls and procedure call
1630 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1631 -- Expand_N_Procedure_Call_Statement. Processing for calls includes:
1633 -- Replace call to Raise_Exception by Raise_Exception always if possible
1634 -- Provide values of actuals for all formals in Extra_Formals list
1635 -- Replace "call" to enumeration literal function by literal itself
1636 -- Rewrite call to predefined operator as operator
1637 -- Replace actuals to in-out parameters that are numeric conversions,
1638 -- with explicit assignment to temporaries before and after the call.
1639 -- Remove optional actuals if First_Optional_Parameter specified.
1641 -- Note that the list of actuals has been filled with default expressions
1642 -- during semantic analysis of the call. Only the extra actuals required
1643 -- for the 'Constrained attribute and for accessibility checks are added
1646 procedure Expand_Call (N : Node_Id) is
1647 Loc : constant Source_Ptr := Sloc (N);
1648 Remote : constant Boolean := Is_Remote_Call (N);
1650 Orig_Subp : Entity_Id := Empty;
1651 Parent_Subp : Entity_Id;
1652 Parent_Formal : Entity_Id;
1655 Prev : Node_Id := Empty;
1657 Prev_Orig : Node_Id;
1658 -- Original node for an actual, which may have been rewritten. If the
1659 -- actual is a function call that has been transformed from a selected
1660 -- component, the original node is unanalyzed. Otherwise, it carries
1661 -- semantic information used to generate additional actuals.
1664 Extra_Actuals : List_Id := No_List;
1666 CW_Interface_Formals_Present : Boolean := False;
1668 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1669 -- Adds one entry to the end of the actual parameter list. Used for
1670 -- default parameters and for extra actuals (for Extra_Formals). The
1671 -- argument is an N_Parameter_Association node.
1673 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1674 -- Adds an extra actual to the list of extra actuals. Expr is the
1675 -- expression for the value of the actual, EF is the entity for the
1678 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1679 -- Within an instance, a type derived from a non-tagged formal derived
1680 -- type inherits from the original parent, not from the actual. This is
1681 -- tested in 4723-003. The current derivation mechanism has the derived
1682 -- type inherit from the actual, which is only correct outside of the
1683 -- instance. If the subprogram is inherited, we test for this particular
1684 -- case through a convoluted tree traversal before setting the proper
1685 -- subprogram to be called.
1687 --------------------------
1688 -- Add_Actual_Parameter --
1689 --------------------------
1691 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1692 Actual_Expr : constant Node_Id :=
1693 Explicit_Actual_Parameter (Insert_Param);
1696 -- Case of insertion is first named actual
1698 if No (Prev) or else
1699 Nkind (Parent (Prev)) /= N_Parameter_Association
1701 Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
1702 Set_First_Named_Actual (N, Actual_Expr);
1705 if No (Parameter_Associations (N)) then
1706 Set_Parameter_Associations (N, New_List);
1707 Append (Insert_Param, Parameter_Associations (N));
1710 Insert_After (Prev, Insert_Param);
1713 -- Case of insertion is not first named actual
1716 Set_Next_Named_Actual
1717 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1718 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1719 Append (Insert_Param, Parameter_Associations (N));
1722 Prev := Actual_Expr;
1723 end Add_Actual_Parameter;
1725 ----------------------
1726 -- Add_Extra_Actual --
1727 ----------------------
1729 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1730 Loc : constant Source_Ptr := Sloc (Expr);
1733 if Extra_Actuals = No_List then
1734 Extra_Actuals := New_List;
1735 Set_Parent (Extra_Actuals, N);
1738 Append_To (Extra_Actuals,
1739 Make_Parameter_Association (Loc,
1740 Explicit_Actual_Parameter => Expr,
1742 Make_Identifier (Loc, Chars (EF))));
1744 Analyze_And_Resolve (Expr, Etype (EF));
1745 end Add_Extra_Actual;
1747 ---------------------------
1748 -- Inherited_From_Formal --
1749 ---------------------------
1751 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1753 Gen_Par : Entity_Id;
1754 Gen_Prim : Elist_Id;
1759 -- If the operation is inherited, it is attached to the corresponding
1760 -- type derivation. If the parent in the derivation is a generic
1761 -- actual, it is a subtype of the actual, and we have to recover the
1762 -- original derived type declaration to find the proper parent.
1764 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1765 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1766 or else Nkind (Type_Definition (Original_Node (Parent (S)))) /=
1767 N_Derived_Type_Definition
1768 or else not In_Instance
1775 (Type_Definition (Original_Node (Parent (S)))));
1777 if Nkind (Indic) = N_Subtype_Indication then
1778 Par := Entity (Subtype_Mark (Indic));
1780 Par := Entity (Indic);
1784 if not Is_Generic_Actual_Type (Par)
1785 or else Is_Tagged_Type (Par)
1786 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1787 or else not In_Open_Scopes (Scope (Par))
1792 Gen_Par := Generic_Parent_Type (Parent (Par));
1795 -- If the actual has no generic parent type, the formal is not
1796 -- a formal derived type, so nothing to inherit.
1798 if No (Gen_Par) then
1802 -- If the generic parent type is still the generic type, this is a
1803 -- private formal, not a derived formal, and there are no operations
1804 -- inherited from the formal.
1806 if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
1810 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
1812 Elmt := First_Elmt (Gen_Prim);
1813 while Present (Elmt) loop
1814 if Chars (Node (Elmt)) = Chars (S) then
1820 F1 := First_Formal (S);
1821 F2 := First_Formal (Node (Elmt));
1823 and then Present (F2)
1825 if Etype (F1) = Etype (F2)
1826 or else Etype (F2) = Gen_Par
1832 exit; -- not the right subprogram
1844 raise Program_Error;
1845 end Inherited_From_Formal;
1847 -- Start of processing for Expand_Call
1850 -- Ignore if previous error
1852 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1856 -- Call using access to subprogram with explicit dereference
1858 if Nkind (Name (N)) = N_Explicit_Dereference then
1859 Subp := Etype (Name (N));
1860 Parent_Subp := Empty;
1862 -- Case of call to simple entry, where the Name is a selected component
1863 -- whose prefix is the task, and whose selector name is the entry name
1865 elsif Nkind (Name (N)) = N_Selected_Component then
1866 Subp := Entity (Selector_Name (Name (N)));
1867 Parent_Subp := Empty;
1869 -- Case of call to member of entry family, where Name is an indexed
1870 -- component, with the prefix being a selected component giving the
1871 -- task and entry family name, and the index being the entry index.
1873 elsif Nkind (Name (N)) = N_Indexed_Component then
1874 Subp := Entity (Selector_Name (Prefix (Name (N))));
1875 Parent_Subp := Empty;
1880 Subp := Entity (Name (N));
1881 Parent_Subp := Alias (Subp);
1883 -- Replace call to Raise_Exception by call to Raise_Exception_Always
1884 -- if we can tell that the first parameter cannot possibly be null.
1885 -- This helps optimization and also generation of warnings.
1887 -- We do not do this if Raise_Exception_Always does not exist, which
1888 -- can happen in configurable run time profiles which provide only a
1889 -- Raise_Exception, which is in fact an unconditional raise anyway.
1891 if Is_RTE (Subp, RE_Raise_Exception)
1892 and then RTE_Available (RE_Raise_Exception_Always)
1895 FA : constant Node_Id := Original_Node (First_Actual (N));
1898 -- The case we catch is where the first argument is obtained
1899 -- using the Identity attribute (which must always be
1902 if Nkind (FA) = N_Attribute_Reference
1903 and then Attribute_Name (FA) = Name_Identity
1905 Subp := RTE (RE_Raise_Exception_Always);
1906 Set_Name (N, New_Occurrence_Of (Subp, Loc));
1911 if Ekind (Subp) = E_Entry then
1912 Parent_Subp := Empty;
1916 -- Ada 2005 (AI-345): We have a procedure call as a triggering
1917 -- alternative in an asynchronous select or as an entry call in
1918 -- a conditional or timed select. Check whether the procedure call
1919 -- is a renaming of an entry and rewrite it as an entry call.
1921 if Ada_Version >= Ada_05
1922 and then Nkind (N) = N_Procedure_Call_Statement
1924 ((Nkind (Parent (N)) = N_Triggering_Alternative
1925 and then Triggering_Statement (Parent (N)) = N)
1927 (Nkind (Parent (N)) = N_Entry_Call_Alternative
1928 and then Entry_Call_Statement (Parent (N)) = N))
1932 Ren_Root : Entity_Id := Subp;
1935 -- This may be a chain of renamings, find the root
1937 if Present (Alias (Ren_Root)) then
1938 Ren_Root := Alias (Ren_Root);
1941 if Present (Original_Node (Parent (Parent (Ren_Root)))) then
1942 Ren_Decl := Original_Node (Parent (Parent (Ren_Root)));
1944 if Nkind (Ren_Decl) = N_Subprogram_Renaming_Declaration then
1946 Make_Entry_Call_Statement (Loc,
1948 New_Copy_Tree (Name (Ren_Decl)),
1949 Parameter_Associations =>
1950 New_Copy_List_Tree (Parameter_Associations (N))));
1958 -- First step, compute extra actuals, corresponding to any
1959 -- Extra_Formals present. Note that we do not access Extra_Formals
1960 -- directly, instead we simply note the presence of the extra
1961 -- formals as we process the regular formals and collect the
1962 -- corresponding actuals in Extra_Actuals.
1964 -- We also generate any required range checks for actuals as we go
1965 -- through the loop, since this is a convenient place to do this.
1967 Formal := First_Formal (Subp);
1968 Actual := First_Actual (N);
1969 while Present (Formal) loop
1971 -- Generate range check if required (not activated yet ???)
1973 -- if Do_Range_Check (Actual) then
1974 -- Set_Do_Range_Check (Actual, False);
1975 -- Generate_Range_Check
1976 -- (Actual, Etype (Formal), CE_Range_Check_Failed);
1979 -- Prepare to examine current entry
1982 Prev_Orig := Original_Node (Prev);
1984 -- The original actual may have been a call written in prefix
1985 -- form, and rewritten before analysis.
1987 if not Analyzed (Prev_Orig)
1989 (Nkind (Actual) = N_Function_Call
1991 Nkind (Actual) = N_Identifier)
1996 -- Ada 2005 (AI-251): Check if any formal is a class-wide interface
1997 -- to expand it in a further round.
1999 CW_Interface_Formals_Present :=
2000 CW_Interface_Formals_Present
2002 (Ekind (Etype (Formal)) = E_Class_Wide_Type
2003 and then Is_Interface (Etype (Etype (Formal))))
2005 (Ekind (Etype (Formal)) = E_Anonymous_Access_Type
2006 and then Is_Interface (Directly_Designated_Type
2007 (Etype (Etype (Formal)))));
2009 -- Create possible extra actual for constrained case. Usually, the
2010 -- extra actual is of the form actual'constrained, but since this
2011 -- attribute is only available for unconstrained records, TRUE is
2012 -- expanded if the type of the formal happens to be constrained (for
2013 -- instance when this procedure is inherited from an unconstrained
2014 -- record to a constrained one) or if the actual has no discriminant
2015 -- (its type is constrained). An exception to this is the case of a
2016 -- private type without discriminants. In this case we pass FALSE
2017 -- because the object has underlying discriminants with defaults.
2019 if Present (Extra_Constrained (Formal)) then
2020 if Ekind (Etype (Prev)) in Private_Kind
2021 and then not Has_Discriminants (Base_Type (Etype (Prev)))
2024 New_Occurrence_Of (Standard_False, Loc),
2025 Extra_Constrained (Formal));
2027 elsif Is_Constrained (Etype (Formal))
2028 or else not Has_Discriminants (Etype (Prev))
2031 New_Occurrence_Of (Standard_True, Loc),
2032 Extra_Constrained (Formal));
2034 -- Do not produce extra actuals for Unchecked_Union parameters.
2035 -- Jump directly to the end of the loop.
2037 elsif Is_Unchecked_Union (Base_Type (Etype (Actual))) then
2038 goto Skip_Extra_Actual_Generation;
2041 -- If the actual is a type conversion, then the constrained
2042 -- test applies to the actual, not the target type.
2048 -- Test for unchecked conversions as well, which can occur
2049 -- as out parameter actuals on calls to stream procedures.
2052 while Nkind (Act_Prev) = N_Type_Conversion
2053 or else Nkind (Act_Prev) = N_Unchecked_Type_Conversion
2055 Act_Prev := Expression (Act_Prev);
2058 -- If the expression is a conversion of a dereference,
2059 -- this is internally generated code that manipulates
2060 -- addresses, e.g. when building interface tables. No
2061 -- check should occur in this case, and the discriminated
2062 -- object is not directly a hand.
2064 if not Comes_From_Source (Actual)
2065 and then Nkind (Actual) = N_Unchecked_Type_Conversion
2066 and then Nkind (Act_Prev) = N_Explicit_Dereference
2069 (New_Occurrence_Of (Standard_False, Loc),
2070 Extra_Constrained (Formal));
2074 (Make_Attribute_Reference (Sloc (Prev),
2076 Duplicate_Subexpr_No_Checks
2077 (Act_Prev, Name_Req => True),
2078 Attribute_Name => Name_Constrained),
2079 Extra_Constrained (Formal));
2085 -- Create possible extra actual for accessibility level
2087 if Present (Extra_Accessibility (Formal)) then
2089 -- Ada 2005 (AI-252): If the actual was rewritten as an Access
2090 -- attribute, then the original actual may be an aliased object
2091 -- occurring as the prefix in a call using "Object.Operation"
2092 -- notation. In that case we must pass the level of the object,
2093 -- so Prev_Orig is reset to Prev and the attribute will be
2094 -- processed by the code for Access attributes further below.
2096 if Prev_Orig /= Prev
2097 and then Nkind (Prev) = N_Attribute_Reference
2099 Get_Attribute_Id (Attribute_Name (Prev)) = Attribute_Access
2100 and then Is_Aliased_View (Prev_Orig)
2105 if Is_Entity_Name (Prev_Orig) then
2107 -- When passing an access parameter as the actual to another
2108 -- access parameter we need to pass along the actual's own
2109 -- associated access level parameter. This is done if we are
2110 -- in the scope of the formal access parameter (if this is an
2111 -- inlined body the extra formal is irrelevant).
2113 if Ekind (Entity (Prev_Orig)) in Formal_Kind
2114 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
2115 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
2118 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
2121 pragma Assert (Present (Parm_Ent));
2123 if Present (Extra_Accessibility (Parm_Ent)) then
2126 (Extra_Accessibility (Parm_Ent), Loc),
2127 Extra_Accessibility (Formal));
2129 -- If the actual access parameter does not have an
2130 -- associated extra formal providing its scope level,
2131 -- then treat the actual as having library-level
2136 (Make_Integer_Literal (Loc,
2137 Intval => Scope_Depth (Standard_Standard)),
2138 Extra_Accessibility (Formal));
2142 -- The actual is a normal access value, so just pass the level
2143 -- of the actual's access type.
2147 (Make_Integer_Literal (Loc,
2148 Intval => Type_Access_Level (Etype (Prev_Orig))),
2149 Extra_Accessibility (Formal));
2153 case Nkind (Prev_Orig) is
2155 when N_Attribute_Reference =>
2157 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
2159 -- For X'Access, pass on the level of the prefix X
2161 when Attribute_Access =>
2163 Make_Integer_Literal (Loc,
2165 Object_Access_Level (Prefix (Prev_Orig))),
2166 Extra_Accessibility (Formal));
2168 -- Treat the unchecked attributes as library-level
2170 when Attribute_Unchecked_Access |
2171 Attribute_Unrestricted_Access =>
2173 Make_Integer_Literal (Loc,
2174 Intval => Scope_Depth (Standard_Standard)),
2175 Extra_Accessibility (Formal));
2177 -- No other cases of attributes returning access
2178 -- values that can be passed to access parameters
2181 raise Program_Error;
2185 -- For allocators we pass the level of the execution of
2186 -- the called subprogram, which is one greater than the
2187 -- current scope level.
2191 Make_Integer_Literal (Loc,
2192 Scope_Depth (Current_Scope) + 1),
2193 Extra_Accessibility (Formal));
2195 -- For other cases we simply pass the level of the
2196 -- actual's access type.
2200 Make_Integer_Literal (Loc,
2201 Intval => Type_Access_Level (Etype (Prev_Orig))),
2202 Extra_Accessibility (Formal));
2208 -- Perform the check of 4.6(49) that prevents a null value from being
2209 -- passed as an actual to an access parameter. Note that the check is
2210 -- elided in the common cases of passing an access attribute or
2211 -- access parameter as an actual. Also, we currently don't enforce
2212 -- this check for expander-generated actuals and when -gnatdj is set.
2214 if Ada_Version >= Ada_05 then
2216 -- Ada 2005 (AI-231): Check null-excluding access types
2218 if Is_Access_Type (Etype (Formal))
2219 and then Can_Never_Be_Null (Etype (Formal))
2220 and then Nkind (Prev) /= N_Raise_Constraint_Error
2221 and then (Nkind (Prev) = N_Null
2222 or else not Can_Never_Be_Null (Etype (Prev)))
2224 Install_Null_Excluding_Check (Prev);
2227 -- Ada_Version < Ada_05
2230 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
2231 or else Access_Checks_Suppressed (Subp)
2235 elsif Debug_Flag_J then
2238 elsif not Comes_From_Source (Prev) then
2241 elsif Is_Entity_Name (Prev)
2242 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
2246 elsif Nkind (Prev) = N_Allocator
2247 or else Nkind (Prev) = N_Attribute_Reference
2251 -- Suppress null checks when passing to access parameters of Java
2252 -- and CIL subprograms. (Should this be done for other foreign
2253 -- conventions as well ???)
2255 elsif Convention (Subp) = Convention_Java
2256 or else Convention (Subp) = Convention_CIL
2261 Install_Null_Excluding_Check (Prev);
2265 -- Perform appropriate validity checks on parameters that
2268 if Validity_Checks_On then
2269 if (Ekind (Formal) = E_In_Parameter
2270 and then Validity_Check_In_Params)
2272 (Ekind (Formal) = E_In_Out_Parameter
2273 and then Validity_Check_In_Out_Params)
2275 -- If the actual is an indexed component of a packed type (or
2276 -- is an indexed or selected component whose prefix recursively
2277 -- meets this condition), it has not been expanded yet. It will
2278 -- be copied in the validity code that follows, and has to be
2279 -- expanded appropriately, so reanalyze it.
2281 -- What we do is just to unset analyzed bits on prefixes till
2282 -- we reach something that does not have a prefix.
2289 while Nkind (Nod) = N_Indexed_Component
2291 Nkind (Nod) = N_Selected_Component
2293 Set_Analyzed (Nod, False);
2294 Nod := Prefix (Nod);
2298 Ensure_Valid (Actual);
2302 -- For IN OUT and OUT parameters, ensure that subscripts are valid
2303 -- since this is a left side reference. We only do this for calls
2304 -- from the source program since we assume that compiler generated
2305 -- calls explicitly generate any required checks. We also need it
2306 -- only if we are doing standard validity checks, since clearly it
2307 -- is not needed if validity checks are off, and in subscript
2308 -- validity checking mode, all indexed components are checked with
2309 -- a call directly from Expand_N_Indexed_Component.
2311 if Comes_From_Source (N)
2312 and then Ekind (Formal) /= E_In_Parameter
2313 and then Validity_Checks_On
2314 and then Validity_Check_Default
2315 and then not Validity_Check_Subscripts
2317 Check_Valid_Lvalue_Subscripts (Actual);
2320 -- Mark any scalar OUT parameter that is a simple variable as no
2321 -- longer known to be valid (unless the type is always valid). This
2322 -- reflects the fact that if an OUT parameter is never set in a
2323 -- procedure, then it can become invalid on the procedure return.
2325 if Ekind (Formal) = E_Out_Parameter
2326 and then Is_Entity_Name (Actual)
2327 and then Ekind (Entity (Actual)) = E_Variable
2328 and then not Is_Known_Valid (Etype (Actual))
2330 Set_Is_Known_Valid (Entity (Actual), False);
2333 -- For an OUT or IN OUT parameter, if the actual is an entity, then
2334 -- clear current values, since they can be clobbered. We are probably
2335 -- doing this in more places than we need to, but better safe than
2336 -- sorry when it comes to retaining bad current values!
2338 if Ekind (Formal) /= E_In_Parameter
2339 and then Is_Entity_Name (Actual)
2341 Kill_Current_Values (Entity (Actual));
2344 -- If the formal is class wide and the actual is an aggregate, force
2345 -- evaluation so that the back end who does not know about class-wide
2346 -- type, does not generate a temporary of the wrong size.
2348 if not Is_Class_Wide_Type (Etype (Formal)) then
2351 elsif Nkind (Actual) = N_Aggregate
2352 or else (Nkind (Actual) = N_Qualified_Expression
2353 and then Nkind (Expression (Actual)) = N_Aggregate)
2355 Force_Evaluation (Actual);
2358 -- In a remote call, if the formal is of a class-wide type, check
2359 -- that the actual meets the requirements described in E.4(18).
2361 if Remote and then Is_Class_Wide_Type (Etype (Formal)) then
2362 Insert_Action (Actual,
2363 Make_Transportable_Check (Loc,
2364 Duplicate_Subexpr_Move_Checks (Actual)));
2367 -- This label is required when skipping extra actual generation for
2368 -- Unchecked_Union parameters.
2370 <<Skip_Extra_Actual_Generation>>
2372 Next_Actual (Actual);
2373 Next_Formal (Formal);
2376 -- If we are expanding a rhs of an assignment we need to check if tag
2377 -- propagation is needed. You might expect this processing to be in
2378 -- Analyze_Assignment but has to be done earlier (bottom-up) because the
2379 -- assignment might be transformed to a declaration for an unconstrained
2380 -- value if the expression is classwide.
2382 if Nkind (N) = N_Function_Call
2383 and then Is_Tag_Indeterminate (N)
2384 and then Is_Entity_Name (Name (N))
2387 Ass : Node_Id := Empty;
2390 if Nkind (Parent (N)) = N_Assignment_Statement then
2393 elsif Nkind (Parent (N)) = N_Qualified_Expression
2394 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
2396 Ass := Parent (Parent (N));
2398 elsif Nkind (Parent (N)) = N_Explicit_Dereference
2399 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
2401 Ass := Parent (Parent (N));
2405 and then Is_Class_Wide_Type (Etype (Name (Ass)))
2407 if Is_Access_Type (Etype (N)) then
2408 if Designated_Type (Etype (N)) /=
2409 Root_Type (Etype (Name (Ass)))
2412 ("tag-indeterminate expression "
2413 & " must have designated type& ('R'M 5.2 (6))",
2414 N, Root_Type (Etype (Name (Ass))));
2416 Propagate_Tag (Name (Ass), N);
2419 elsif Etype (N) /= Root_Type (Etype (Name (Ass))) then
2421 ("tag-indeterminate expression must have type&"
2422 & "('R'M 5.2 (6))", N, Root_Type (Etype (Name (Ass))));
2425 Propagate_Tag (Name (Ass), N);
2428 -- The call will be rewritten as a dispatching call, and
2429 -- expanded as such.
2436 -- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
2437 -- it to point to the correct secondary virtual table
2439 if (Nkind (N) = N_Function_Call
2440 or else Nkind (N) = N_Procedure_Call_Statement)
2441 and then CW_Interface_Formals_Present
2443 Expand_Interface_Actuals (N);
2446 -- Deals with Dispatch_Call if we still have a call, before expanding
2447 -- extra actuals since this will be done on the re-analysis of the
2448 -- dispatching call. Note that we do not try to shorten the actual
2449 -- list for a dispatching call, it would not make sense to do so.
2450 -- Expansion of dispatching calls is suppressed when VM_Target, because
2451 -- the VM back-ends directly handle the generation of dispatching
2452 -- calls and would have to undo any expansion to an indirect call.
2454 if (Nkind (N) = N_Function_Call
2455 or else Nkind (N) = N_Procedure_Call_Statement)
2456 and then Present (Controlling_Argument (N))
2457 and then VM_Target = No_VM
2459 Expand_Dispatching_Call (N);
2461 -- The following return is worrisome. Is it really OK to
2462 -- skip all remaining processing in this procedure ???
2466 -- Similarly, expand calls to RCI subprograms on which pragma
2467 -- All_Calls_Remote applies. The rewriting will be reanalyzed
2468 -- later. Do this only when the call comes from source since we do
2469 -- not want such a rewritting to occur in expanded code.
2471 elsif Is_All_Remote_Call (N) then
2472 Expand_All_Calls_Remote_Subprogram_Call (N);
2474 -- Similarly, do not add extra actuals for an entry call whose entity
2475 -- is a protected procedure, or for an internal protected subprogram
2476 -- call, because it will be rewritten as a protected subprogram call
2477 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
2479 elsif Is_Protected_Type (Scope (Subp))
2480 and then (Ekind (Subp) = E_Procedure
2481 or else Ekind (Subp) = E_Function)
2485 -- During that loop we gathered the extra actuals (the ones that
2486 -- correspond to Extra_Formals), so now they can be appended.
2489 while Is_Non_Empty_List (Extra_Actuals) loop
2490 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
2494 -- At this point we have all the actuals, so this is the point at
2495 -- which the various expansion activities for actuals is carried out.
2497 Expand_Actuals (N, Subp);
2499 -- If the subprogram is a renaming, or if it is inherited, replace it
2500 -- in the call with the name of the actual subprogram being called.
2501 -- If this is a dispatching call, the run-time decides what to call.
2502 -- The Alias attribute does not apply to entries.
2504 if Nkind (N) /= N_Entry_Call_Statement
2505 and then No (Controlling_Argument (N))
2506 and then Present (Parent_Subp)
2508 if Present (Inherited_From_Formal (Subp)) then
2509 Parent_Subp := Inherited_From_Formal (Subp);
2511 while Present (Alias (Parent_Subp)) loop
2512 Parent_Subp := Alias (Parent_Subp);
2516 -- The below setting of Entity is suspect, see F109-018 discussion???
2518 Set_Entity (Name (N), Parent_Subp);
2520 if Is_Abstract_Subprogram (Parent_Subp)
2521 and then not In_Instance
2524 ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
2527 -- Add an explicit conversion for parameter of the derived type.
2528 -- This is only done for scalar and access in-parameters. Others
2529 -- have been expanded in expand_actuals.
2531 Formal := First_Formal (Subp);
2532 Parent_Formal := First_Formal (Parent_Subp);
2533 Actual := First_Actual (N);
2535 -- It is not clear that conversion is needed for intrinsic
2536 -- subprograms, but it certainly is for those that are user-
2537 -- defined, and that can be inherited on derivation, namely
2538 -- unchecked conversion and deallocation.
2539 -- General case needs study ???
2541 if not Is_Intrinsic_Subprogram (Parent_Subp)
2542 or else Is_Generic_Instance (Parent_Subp)
2544 while Present (Formal) loop
2545 if Etype (Formal) /= Etype (Parent_Formal)
2546 and then Is_Scalar_Type (Etype (Formal))
2547 and then Ekind (Formal) = E_In_Parameter
2549 not Subtypes_Statically_Match
2550 (Etype (Parent_Formal), Etype (Actual))
2551 and then not Raises_Constraint_Error (Actual)
2554 OK_Convert_To (Etype (Parent_Formal),
2555 Relocate_Node (Actual)));
2558 Resolve (Actual, Etype (Parent_Formal));
2559 Enable_Range_Check (Actual);
2561 elsif Is_Access_Type (Etype (Formal))
2562 and then Base_Type (Etype (Parent_Formal)) /=
2563 Base_Type (Etype (Actual))
2565 if Ekind (Formal) /= E_In_Parameter then
2567 Convert_To (Etype (Parent_Formal),
2568 Relocate_Node (Actual)));
2571 Resolve (Actual, Etype (Parent_Formal));
2574 Ekind (Etype (Parent_Formal)) = E_Anonymous_Access_Type
2575 and then Designated_Type (Etype (Parent_Formal))
2577 Designated_Type (Etype (Actual))
2578 and then not Is_Controlling_Formal (Formal)
2580 -- This unchecked conversion is not necessary unless
2581 -- inlining is enabled, because in that case the type
2582 -- mismatch may become visible in the body about to be
2586 Unchecked_Convert_To (Etype (Parent_Formal),
2587 Relocate_Node (Actual)));
2590 Resolve (Actual, Etype (Parent_Formal));
2594 Next_Formal (Formal);
2595 Next_Formal (Parent_Formal);
2596 Next_Actual (Actual);
2601 Subp := Parent_Subp;
2604 -- Check for violation of No_Abort_Statements
2606 if Is_RTE (Subp, RE_Abort_Task) then
2607 Check_Restriction (No_Abort_Statements, N);
2609 -- Check for violation of No_Dynamic_Attachment
2611 elsif RTU_Loaded (Ada_Interrupts)
2612 and then (Is_RTE (Subp, RE_Is_Reserved) or else
2613 Is_RTE (Subp, RE_Is_Attached) or else
2614 Is_RTE (Subp, RE_Current_Handler) or else
2615 Is_RTE (Subp, RE_Attach_Handler) or else
2616 Is_RTE (Subp, RE_Exchange_Handler) or else
2617 Is_RTE (Subp, RE_Detach_Handler) or else
2618 Is_RTE (Subp, RE_Reference))
2620 Check_Restriction (No_Dynamic_Attachment, N);
2623 -- Deal with case where call is an explicit dereference
2625 if Nkind (Name (N)) = N_Explicit_Dereference then
2627 -- Handle case of access to protected subprogram type
2629 if Is_Access_Protected_Subprogram_Type
2630 (Base_Type (Etype (Prefix (Name (N)))))
2632 -- If this is a call through an access to protected operation,
2633 -- the prefix has the form (object'address, operation'access).
2634 -- Rewrite as a for other protected calls: the object is the
2635 -- first parameter of the list of actuals.
2642 Ptr : constant Node_Id := Prefix (Name (N));
2644 T : constant Entity_Id :=
2645 Equivalent_Type (Base_Type (Etype (Ptr)));
2647 D_T : constant Entity_Id :=
2648 Designated_Type (Base_Type (Etype (Ptr)));
2652 Make_Selected_Component (Loc,
2653 Prefix => Unchecked_Convert_To (T, Ptr),
2655 New_Occurrence_Of (First_Entity (T), Loc));
2658 Make_Selected_Component (Loc,
2659 Prefix => Unchecked_Convert_To (T, Ptr),
2661 New_Occurrence_Of (Next_Entity (First_Entity (T)), Loc));
2664 Make_Explicit_Dereference (Loc,
2667 if Present (Parameter_Associations (N)) then
2668 Parm := Parameter_Associations (N);
2673 Prepend (Obj, Parm);
2675 if Etype (D_T) = Standard_Void_Type then
2677 Make_Procedure_Call_Statement (Loc,
2679 Parameter_Associations => Parm);
2682 Make_Function_Call (Loc,
2684 Parameter_Associations => Parm);
2687 Set_First_Named_Actual (Call, First_Named_Actual (N));
2688 Set_Etype (Call, Etype (D_T));
2690 -- We do not re-analyze the call to avoid infinite recursion.
2691 -- We analyze separately the prefix and the object, and set
2692 -- the checks on the prefix that would otherwise be emitted
2693 -- when resolving a call.
2697 Apply_Access_Check (Nam);
2704 -- If this is a call to an intrinsic subprogram, then perform the
2705 -- appropriate expansion to the corresponding tree node and we
2706 -- are all done (since after that the call is gone!)
2708 -- In the case where the intrinsic is to be processed by the back end,
2709 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
2710 -- since the idea in this case is to pass the call unchanged.
2712 if Is_Intrinsic_Subprogram (Subp) then
2713 Expand_Intrinsic_Call (N, Subp);
2717 if Ekind (Subp) = E_Function
2718 or else Ekind (Subp) = E_Procedure
2720 if Is_Inlined (Subp) then
2722 Inlined_Subprogram : declare
2724 Must_Inline : Boolean := False;
2725 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
2726 Scop : constant Entity_Id := Scope (Subp);
2728 function In_Unfrozen_Instance return Boolean;
2729 -- If the subprogram comes from an instance in the same
2730 -- unit, and the instance is not yet frozen, inlining might
2731 -- trigger order-of-elaboration problems in gigi.
2733 --------------------------
2734 -- In_Unfrozen_Instance --
2735 --------------------------
2737 function In_Unfrozen_Instance return Boolean is
2743 and then S /= Standard_Standard
2745 if Is_Generic_Instance (S)
2746 and then Present (Freeze_Node (S))
2747 and then not Analyzed (Freeze_Node (S))
2756 end In_Unfrozen_Instance;
2758 -- Start of processing for Inlined_Subprogram
2761 -- Verify that the body to inline has already been seen, and
2762 -- that if the body is in the current unit the inlining does
2763 -- not occur earlier. This avoids order-of-elaboration problems
2766 -- This should be documented in sinfo/einfo ???
2769 or else Nkind (Spec) /= N_Subprogram_Declaration
2770 or else No (Body_To_Inline (Spec))
2772 Must_Inline := False;
2774 -- If this an inherited function that returns a private
2775 -- type, do not inline if the full view is an unconstrained
2776 -- array, because such calls cannot be inlined.
2778 elsif Present (Orig_Subp)
2779 and then Is_Array_Type (Etype (Orig_Subp))
2780 and then not Is_Constrained (Etype (Orig_Subp))
2782 Must_Inline := False;
2784 elsif In_Unfrozen_Instance then
2785 Must_Inline := False;
2788 Bod := Body_To_Inline (Spec);
2790 if (In_Extended_Main_Code_Unit (N)
2791 or else In_Extended_Main_Code_Unit (Parent (N))
2792 or else Is_Always_Inlined (Subp))
2793 and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
2795 Earlier_In_Extended_Unit (Sloc (Bod), Loc))
2797 Must_Inline := True;
2799 -- If we are compiling a package body that is not the main
2800 -- unit, it must be for inlining/instantiation purposes,
2801 -- in which case we inline the call to insure that the same
2802 -- temporaries are generated when compiling the body by
2803 -- itself. Otherwise link errors can occur.
2805 -- If the function being called is itself in the main unit,
2806 -- we cannot inline, because there is a risk of double
2807 -- elaboration and/or circularity: the inlining can make
2808 -- visible a private entity in the body of the main unit,
2809 -- that gigi will see before its sees its proper definition.
2811 elsif not (In_Extended_Main_Code_Unit (N))
2812 and then In_Package_Body
2814 Must_Inline := not In_Extended_Main_Source_Unit (Subp);
2819 Expand_Inlined_Call (N, Subp, Orig_Subp);
2822 -- Let the back end handle it
2824 Add_Inlined_Body (Subp);
2826 if Front_End_Inlining
2827 and then Nkind (Spec) = N_Subprogram_Declaration
2828 and then (In_Extended_Main_Code_Unit (N))
2829 and then No (Body_To_Inline (Spec))
2830 and then not Has_Completion (Subp)
2831 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
2834 ("cannot inline& (body not seen yet)?",
2838 end Inlined_Subprogram;
2842 -- Check for a protected subprogram. This is either an intra-object
2843 -- call, or a protected function call. Protected procedure calls are
2844 -- rewritten as entry calls and handled accordingly.
2846 -- In Ada 2005, this may be an indirect call to an access parameter
2847 -- that is an access_to_subprogram. In that case the anonymous type
2848 -- has a scope that is a protected operation, but the call is a
2851 Scop := Scope (Subp);
2853 if Nkind (N) /= N_Entry_Call_Statement
2854 and then Is_Protected_Type (Scop)
2855 and then Ekind (Subp) /= E_Subprogram_Type
2857 -- If the call is an internal one, it is rewritten as a call to
2858 -- to the corresponding unprotected subprogram.
2860 Expand_Protected_Subprogram_Call (N, Subp, Scop);
2863 -- Functions returning controlled objects need special attention
2864 -- If the return type is limited the context is an initialization
2865 -- and different processing applies.
2867 if Controlled_Type (Etype (Subp))
2868 and then not Is_Inherently_Limited_Type (Etype (Subp))
2869 and then not Is_Limited_Interface (Etype (Subp))
2871 Expand_Ctrl_Function_Call (N);
2874 -- Test for First_Optional_Parameter, and if so, truncate parameter
2875 -- list if there are optional parameters at the trailing end.
2876 -- Note we never delete procedures for call via a pointer.
2878 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
2879 and then Present (First_Optional_Parameter (Subp))
2882 Last_Keep_Arg : Node_Id;
2885 -- Last_Keep_Arg will hold the last actual that should be
2886 -- retained. If it remains empty at the end, it means that
2887 -- all parameters are optional.
2889 Last_Keep_Arg := Empty;
2891 -- Find first optional parameter, must be present since we
2892 -- checked the validity of the parameter before setting it.
2894 Formal := First_Formal (Subp);
2895 Actual := First_Actual (N);
2896 while Formal /= First_Optional_Parameter (Subp) loop
2897 Last_Keep_Arg := Actual;
2898 Next_Formal (Formal);
2899 Next_Actual (Actual);
2902 -- We have Formal and Actual pointing to the first potentially
2903 -- droppable argument. We can drop all the trailing arguments
2904 -- whose actual matches the default. Note that we know that all
2905 -- remaining formals have defaults, because we checked that this
2906 -- requirement was met before setting First_Optional_Parameter.
2908 -- We use Fully_Conformant_Expressions to check for identity
2909 -- between formals and actuals, which may miss some cases, but
2910 -- on the other hand, this is only an optimization (if we fail
2911 -- to truncate a parameter it does not affect functionality).
2912 -- So if the default is 3 and the actual is 1+2, we consider
2913 -- them unequal, which hardly seems worrisome.
2915 while Present (Formal) loop
2916 if not Fully_Conformant_Expressions
2917 (Actual, Default_Value (Formal))
2919 Last_Keep_Arg := Actual;
2922 Next_Formal (Formal);
2923 Next_Actual (Actual);
2926 -- If no arguments, delete entire list, this is the easy case
2928 if No (Last_Keep_Arg) then
2929 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2930 Delete_Tree (Remove_Head (Parameter_Associations (N)));
2933 Set_Parameter_Associations (N, No_List);
2934 Set_First_Named_Actual (N, Empty);
2936 -- Case where at the last retained argument is positional. This
2937 -- is also an easy case, since the retained arguments are already
2938 -- in the right form, and we don't need to worry about the order
2939 -- of arguments that get eliminated.
2941 elsif Is_List_Member (Last_Keep_Arg) then
2942 while Present (Next (Last_Keep_Arg)) loop
2943 Delete_Tree (Remove_Next (Last_Keep_Arg));
2946 Set_First_Named_Actual (N, Empty);
2948 -- This is the annoying case where the last retained argument
2949 -- is a named parameter. Since the original arguments are not
2950 -- in declaration order, we may have to delete some fairly
2951 -- random collection of arguments.
2959 -- First step, remove all the named parameters from the
2960 -- list (they are still chained using First_Named_Actual
2961 -- and Next_Named_Actual, so we have not lost them!)
2963 Temp := First (Parameter_Associations (N));
2965 -- Case of all parameters named, remove them all
2967 if Nkind (Temp) = N_Parameter_Association then
2968 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2969 Temp := Remove_Head (Parameter_Associations (N));
2972 -- Case of mixed positional/named, remove named parameters
2975 while Nkind (Next (Temp)) /= N_Parameter_Association loop
2979 while Present (Next (Temp)) loop
2980 Remove (Next (Temp));
2984 -- Now we loop through the named parameters, till we get
2985 -- to the last one to be retained, adding them to the list.
2986 -- Note that the Next_Named_Actual list does not need to be
2987 -- touched since we are only reordering them on the actual
2988 -- parameter association list.
2990 Passoc := Parent (First_Named_Actual (N));
2992 Temp := Relocate_Node (Passoc);
2994 (Parameter_Associations (N), Temp);
2996 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
2997 Passoc := Parent (Next_Named_Actual (Passoc));
3000 Set_Next_Named_Actual (Temp, Empty);
3003 Temp := Next_Named_Actual (Passoc);
3004 exit when No (Temp);
3005 Set_Next_Named_Actual
3006 (Passoc, Next_Named_Actual (Parent (Temp)));
3014 -- Special processing for Ada 2005 AI-329, which requires a call to
3015 -- Raise_Exception to raise Constraint_Error if the Exception_Id is
3016 -- null. Note that we never need to do this in GNAT mode, or if the
3017 -- parameter to Raise_Exception is a use of Identity, since in these
3018 -- cases we know that the parameter is never null.
3020 -- Note: We must check that the node has not been inlined. This is
3021 -- required because under zfp the Raise_Exception subprogram has the
3022 -- pragma inline_always (and hence the call has been expanded above
3023 -- into a block containing the code of the subprogram).
3025 if Ada_Version >= Ada_05
3026 and then not GNAT_Mode
3027 and then Is_RTE (Subp, RE_Raise_Exception)
3028 and then Nkind (N) = N_Procedure_Call_Statement
3029 and then (Nkind (First_Actual (N)) /= N_Attribute_Reference
3030 or else Attribute_Name (First_Actual (N)) /= Name_Identity)
3033 RCE : constant Node_Id :=
3034 Make_Raise_Constraint_Error (Loc,
3035 Reason => CE_Null_Exception_Id);
3037 Insert_After (N, RCE);
3043 --------------------------
3044 -- Expand_Inlined_Call --
3045 --------------------------
3047 procedure Expand_Inlined_Call
3050 Orig_Subp : Entity_Id)
3052 Loc : constant Source_Ptr := Sloc (N);
3053 Is_Predef : constant Boolean :=
3054 Is_Predefined_File_Name
3055 (Unit_File_Name (Get_Source_Unit (Subp)));
3056 Orig_Bod : constant Node_Id :=
3057 Body_To_Inline (Unit_Declaration_Node (Subp));
3062 Decls : constant List_Id := New_List;
3063 Exit_Lab : Entity_Id := Empty;
3070 Ret_Type : Entity_Id;
3074 Temp_Typ : Entity_Id;
3076 Is_Unc : constant Boolean :=
3077 Is_Array_Type (Etype (Subp))
3078 and then not Is_Constrained (Etype (Subp));
3079 -- If the type returned by the function is unconstrained and the
3080 -- call can be inlined, special processing is required.
3082 function Is_Null_Procedure return Boolean;
3083 -- Predicate to recognize stubbed procedures and null procedures, for
3084 -- which there is no need for the full inlining mechanism.
3086 procedure Make_Exit_Label;
3087 -- Build declaration for exit label to be used in Return statements
3089 function Process_Formals (N : Node_Id) return Traverse_Result;
3090 -- Replace occurrence of a formal with the corresponding actual, or
3091 -- the thunk generated for it.
3093 function Process_Sloc (Nod : Node_Id) return Traverse_Result;
3094 -- If the call being expanded is that of an internal subprogram,
3095 -- set the sloc of the generated block to that of the call itself,
3096 -- so that the expansion is skipped by the -next- command in gdb.
3097 -- Same processing for a subprogram in a predefined file, e.g.
3098 -- Ada.Tags. If Debug_Generated_Code is true, suppress this change
3099 -- to simplify our own development.
3101 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
3102 -- If the function body is a single expression, replace call with
3103 -- expression, else insert block appropriately.
3105 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
3106 -- If procedure body has no local variables, inline body without
3107 -- creating block, otherwise rewrite call with block.
3109 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean;
3110 -- Determine whether a formal parameter is used only once in Orig_Bod
3112 -----------------------
3113 -- Is_Null_Procedure --
3114 -----------------------
3116 function Is_Null_Procedure return Boolean is
3117 Decl : constant Node_Id := Unit_Declaration_Node (Subp);
3120 if Ekind (Subp) /= E_Procedure then
3123 elsif Nkind (Orig_Bod) /= N_Subprogram_Body then
3126 -- Check if this is an Ada 2005 null procedure
3128 elsif Nkind (Decl) = N_Subprogram_Declaration
3129 and then Null_Present (Specification (Decl))
3133 -- Check if the body contains only a null statement, followed by the
3134 -- return statement added during expansion.
3138 Stat : constant Node_Id :=
3140 (Statements (Handled_Statement_Sequence (Orig_Bod)));
3142 Stat2 : constant Node_Id := Next (Stat);
3146 Nkind (Stat) = N_Null_Statement
3150 (Nkind (Stat2) = N_Return_Statement
3151 and then No (Next (Stat2))));
3154 end Is_Null_Procedure;
3156 ---------------------
3157 -- Make_Exit_Label --
3158 ---------------------
3160 procedure Make_Exit_Label is
3162 -- Create exit label for subprogram if one does not exist yet
3164 if No (Exit_Lab) then
3166 Make_Identifier (Loc,
3167 Chars => New_Internal_Name ('L'));
3169 Make_Defining_Identifier (Loc, Chars (Lab_Id)));
3170 Exit_Lab := Make_Label (Loc, Lab_Id);
3173 Make_Implicit_Label_Declaration (Loc,
3174 Defining_Identifier => Entity (Lab_Id),
3175 Label_Construct => Exit_Lab);
3177 end Make_Exit_Label;
3179 ---------------------
3180 -- Process_Formals --
3181 ---------------------
3183 function Process_Formals (N : Node_Id) return Traverse_Result is
3189 if Is_Entity_Name (N)
3190 and then Present (Entity (N))
3195 and then Scope (E) = Subp
3197 A := Renamed_Object (E);
3199 -- Rewrite the occurrence of the formal into an occurrence of
3200 -- the actual. Also establish visibility on the proper view of
3201 -- the actual's subtype for the body's context (if the actual's
3202 -- subtype is private at the call point but its full view is
3203 -- visible to the body, then the inlined tree here must be
3204 -- analyzed with the full view).
3206 if Is_Entity_Name (A) then
3207 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
3208 Check_Private_View (N);
3210 elsif Nkind (A) = N_Defining_Identifier then
3211 Rewrite (N, New_Occurrence_Of (A, Loc));
3212 Check_Private_View (N);
3214 else -- numeric literal
3215 Rewrite (N, New_Copy (A));
3221 elsif Nkind (N) = N_Return_Statement then
3223 if No (Expression (N)) then
3225 Rewrite (N, Make_Goto_Statement (Loc,
3226 Name => New_Copy (Lab_Id)));
3229 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
3230 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
3232 -- Function body is a single expression. No need for
3238 Num_Ret := Num_Ret + 1;
3242 -- Because of the presence of private types, the views of the
3243 -- expression and the context may be different, so place an
3244 -- unchecked conversion to the context type to avoid spurious
3245 -- errors, eg. when the expression is a numeric literal and
3246 -- the context is private. If the expression is an aggregate,
3247 -- use a qualified expression, because an aggregate is not a
3248 -- legal argument of a conversion.
3250 if Nkind (Expression (N)) = N_Aggregate
3251 or else Nkind (Expression (N)) = N_Null
3254 Make_Qualified_Expression (Sloc (N),
3255 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
3256 Expression => Relocate_Node (Expression (N)));
3259 Unchecked_Convert_To
3260 (Ret_Type, Relocate_Node (Expression (N)));
3263 if Nkind (Targ) = N_Defining_Identifier then
3265 Make_Assignment_Statement (Loc,
3266 Name => New_Occurrence_Of (Targ, Loc),
3267 Expression => Ret));
3270 Make_Assignment_Statement (Loc,
3271 Name => New_Copy (Targ),
3272 Expression => Ret));
3275 Set_Assignment_OK (Name (N));
3277 if Present (Exit_Lab) then
3279 Make_Goto_Statement (Loc,
3280 Name => New_Copy (Lab_Id)));
3286 -- Remove pragma Unreferenced since it may refer to formals that
3287 -- are not visible in the inlined body, and in any case we will
3288 -- not be posting warnings on the inlined body so it is unneeded.
3290 elsif Nkind (N) = N_Pragma
3291 and then Chars (N) = Name_Unreferenced
3293 Rewrite (N, Make_Null_Statement (Sloc (N)));
3299 end Process_Formals;
3301 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
3307 function Process_Sloc (Nod : Node_Id) return Traverse_Result is
3309 if not Debug_Generated_Code then
3310 Set_Sloc (Nod, Sloc (N));
3311 Set_Comes_From_Source (Nod, False);
3317 procedure Reset_Slocs is new Traverse_Proc (Process_Sloc);
3319 ---------------------------
3320 -- Rewrite_Function_Call --
3321 ---------------------------
3323 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
3324 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
3325 Fst : constant Node_Id := First (Statements (HSS));
3328 -- Optimize simple case: function body is a single return statement,
3329 -- which has been expanded into an assignment.
3331 if Is_Empty_List (Declarations (Blk))
3332 and then Nkind (Fst) = N_Assignment_Statement
3333 and then No (Next (Fst))
3336 -- The function call may have been rewritten as the temporary
3337 -- that holds the result of the call, in which case remove the
3338 -- now useless declaration.
3340 if Nkind (N) = N_Identifier
3341 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
3343 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
3346 Rewrite (N, Expression (Fst));
3348 elsif Nkind (N) = N_Identifier
3349 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
3351 -- The block assigns the result of the call to the temporary
3353 Insert_After (Parent (Entity (N)), Blk);
3355 elsif Nkind (Parent (N)) = N_Assignment_Statement
3357 (Is_Entity_Name (Name (Parent (N)))
3359 (Nkind (Name (Parent (N))) = N_Explicit_Dereference
3360 and then Is_Entity_Name (Prefix (Name (Parent (N))))))
3362 -- Replace assignment with the block
3365 Original_Assignment : constant Node_Id := Parent (N);
3368 -- Preserve the original assignment node to keep the complete
3369 -- assignment subtree consistent enough for Analyze_Assignment
3370 -- to proceed (specifically, the original Lhs node must still
3371 -- have an assignment statement as its parent).
3373 -- We cannot rely on Original_Node to go back from the block
3374 -- node to the assignment node, because the assignment might
3375 -- already be a rewrite substitution.
3377 Discard_Node (Relocate_Node (Original_Assignment));
3378 Rewrite (Original_Assignment, Blk);
3381 elsif Nkind (Parent (N)) = N_Object_Declaration then
3382 Set_Expression (Parent (N), Empty);
3383 Insert_After (Parent (N), Blk);
3386 Insert_Before (Parent (N), Blk);
3388 end Rewrite_Function_Call;
3390 ----------------------------
3391 -- Rewrite_Procedure_Call --
3392 ----------------------------
3394 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
3395 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
3397 -- If there is a transient scope for N, this will be the scope of the
3398 -- actions for N, and the statements in Blk need to be within this
3399 -- scope. For example, they need to have visibility on the constant
3400 -- declarations created for the formals.
3402 -- If N needs no transient scope, and if there are no declarations in
3403 -- the inlined body, we can do a little optimization and insert the
3404 -- statements for the body directly after N, and rewrite N to a
3405 -- null statement, instead of rewriting N into a full-blown block
3408 if not Scope_Is_Transient
3409 and then Is_Empty_List (Declarations (Blk))
3411 Insert_List_After (N, Statements (HSS));
3412 Rewrite (N, Make_Null_Statement (Loc));
3416 end Rewrite_Procedure_Call;
3418 -------------------------
3419 -- Formal_Is_Used_Once --
3420 -------------------------
3422 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean is
3423 Use_Counter : Int := 0;
3425 function Count_Uses (N : Node_Id) return Traverse_Result;
3426 -- Traverse the tree and count the uses of the formal parameter.
3427 -- In this case, for optimization purposes, we do not need to
3428 -- continue the traversal once more than one use is encountered.
3434 function Count_Uses (N : Node_Id) return Traverse_Result is
3436 -- The original node is an identifier
3438 if Nkind (N) = N_Identifier
3439 and then Present (Entity (N))
3441 -- Original node's entity points to the one in the copied body
3443 and then Nkind (Entity (N)) = N_Identifier
3444 and then Present (Entity (Entity (N)))
3446 -- The entity of the copied node is the formal parameter
3448 and then Entity (Entity (N)) = Formal
3450 Use_Counter := Use_Counter + 1;
3452 if Use_Counter > 1 then
3454 -- Denote more than one use and abandon the traversal
3465 procedure Count_Formal_Uses is new Traverse_Proc (Count_Uses);
3467 -- Start of processing for Formal_Is_Used_Once
3470 Count_Formal_Uses (Orig_Bod);
3471 return Use_Counter = 1;
3472 end Formal_Is_Used_Once;
3474 -- Start of processing for Expand_Inlined_Call
3477 -- Check for special case of To_Address call, and if so, just do an
3478 -- unchecked conversion instead of expanding the call. Not only is this
3479 -- more efficient, but it also avoids problem with order of elaboration
3480 -- when address clauses are inlined (address expression elaborated at
3483 if Subp = RTE (RE_To_Address) then
3485 Unchecked_Convert_To
3487 Relocate_Node (First_Actual (N))));
3490 elsif Is_Null_Procedure then
3491 Rewrite (N, Make_Null_Statement (Loc));
3495 -- Check for an illegal attempt to inline a recursive procedure. If the
3496 -- subprogram has parameters this is detected when trying to supply a
3497 -- binding for parameters that already have one. For parameterless
3498 -- subprograms this must be done explicitly.
3500 if In_Open_Scopes (Subp) then
3501 Error_Msg_N ("call to recursive subprogram cannot be inlined?", N);
3502 Set_Is_Inlined (Subp, False);
3506 if Nkind (Orig_Bod) = N_Defining_Identifier
3507 or else Nkind (Orig_Bod) = N_Defining_Operator_Symbol
3509 -- Subprogram is a renaming_as_body. Calls appearing after the
3510 -- renaming can be replaced with calls to the renamed entity
3511 -- directly, because the subprograms are subtype conformant. If
3512 -- the renamed subprogram is an inherited operation, we must redo
3513 -- the expansion because implicit conversions may be needed.
3515 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
3517 if Present (Alias (Orig_Bod)) then
3524 -- Use generic machinery to copy body of inlined subprogram, as if it
3525 -- were an instantiation, resetting source locations appropriately, so
3526 -- that nested inlined calls appear in the main unit.
3528 Save_Env (Subp, Empty);
3529 Set_Copied_Sloc_For_Inlined_Body (N, Defining_Entity (Orig_Bod));
3531 Bod := Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
3533 Make_Block_Statement (Loc,
3534 Declarations => Declarations (Bod),
3535 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
3537 if No (Declarations (Bod)) then
3538 Set_Declarations (Blk, New_List);
3541 -- For the unconstrained case, capture the name of the local
3542 -- variable that holds the result. This must be the first declaration
3543 -- in the block, because its bounds cannot depend on local variables.
3544 -- Otherwise there is no way to declare the result outside of the
3545 -- block. Needless to say, in general the bounds will depend on the
3546 -- actuals in the call.
3549 Targ1 := Defining_Identifier (First (Declarations (Blk)));
3552 -- If this is a derived function, establish the proper return type
3554 if Present (Orig_Subp)
3555 and then Orig_Subp /= Subp
3557 Ret_Type := Etype (Orig_Subp);
3559 Ret_Type := Etype (Subp);
3562 -- Create temporaries for the actuals that are expressions, or that
3563 -- are scalars and require copying to preserve semantics.
3565 F := First_Formal (Subp);
3566 A := First_Actual (N);
3567 while Present (F) loop
3568 if Present (Renamed_Object (F)) then
3569 Error_Msg_N ("cannot inline call to recursive subprogram", N);
3573 -- If the argument may be a controlling argument in a call within
3574 -- the inlined body, we must preserve its classwide nature to insure
3575 -- that dynamic dispatching take place subsequently. If the formal
3576 -- has a constraint it must be preserved to retain the semantics of
3579 if Is_Class_Wide_Type (Etype (F))
3580 or else (Is_Access_Type (Etype (F))
3582 Is_Class_Wide_Type (Designated_Type (Etype (F))))
3584 Temp_Typ := Etype (F);
3586 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
3587 and then Etype (F) /= Base_Type (Etype (F))
3589 Temp_Typ := Etype (F);
3592 Temp_Typ := Etype (A);
3595 -- If the actual is a simple name or a literal, no need to
3596 -- create a temporary, object can be used directly.
3598 -- If the actual is a literal and the formal has its address taken,
3599 -- we cannot pass the literal itself as an argument, so its value
3600 -- must be captured in a temporary.
3602 if (Is_Entity_Name (A)
3604 (not Is_Scalar_Type (Etype (A))
3605 or else Ekind (Entity (A)) = E_Enumeration_Literal))
3607 -- When the actual is an identifier and the corresponding formal
3608 -- is used only once in the original body, the formal can be
3609 -- substituted directly with the actual parameter.
3611 or else (Nkind (A) = N_Identifier
3612 and then Formal_Is_Used_Once (F))
3615 ((Nkind (A) = N_Real_Literal or else
3616 Nkind (A) = N_Integer_Literal or else
3617 Nkind (A) = N_Character_Literal)
3618 and then not Address_Taken (F))
3620 if Etype (F) /= Etype (A) then
3622 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
3624 Set_Renamed_Object (F, A);
3629 Make_Defining_Identifier (Loc,
3630 Chars => New_Internal_Name ('C'));
3632 -- If the actual for an in/in-out parameter is a view conversion,
3633 -- make it into an unchecked conversion, given that an untagged
3634 -- type conversion is not a proper object for a renaming.
3636 -- In-out conversions that involve real conversions have already
3637 -- been transformed in Expand_Actuals.
3639 if Nkind (A) = N_Type_Conversion
3640 and then Ekind (F) /= E_In_Parameter
3643 Make_Unchecked_Type_Conversion (Loc,
3644 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
3645 Expression => Relocate_Node (Expression (A)));
3647 elsif Etype (F) /= Etype (A) then
3648 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
3649 Temp_Typ := Etype (F);
3652 New_A := Relocate_Node (A);
3655 Set_Sloc (New_A, Sloc (N));
3657 -- If the actual has a by-reference type, it cannot be copied, so
3658 -- its value is captured in a renaming declaration. Otherwise
3659 -- declare a local constant initialized with the actual.
3661 if Ekind (F) = E_In_Parameter
3662 and then not Is_Limited_Type (Etype (A))
3663 and then not Is_Tagged_Type (Etype (A))
3666 Make_Object_Declaration (Loc,
3667 Defining_Identifier => Temp,
3668 Constant_Present => True,
3669 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
3670 Expression => New_A);
3673 Make_Object_Renaming_Declaration (Loc,
3674 Defining_Identifier => Temp,
3675 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
3679 Append (Decl, Decls);
3680 Set_Renamed_Object (F, Temp);
3687 -- Establish target of function call. If context is not assignment or
3688 -- declaration, create a temporary as a target. The declaration for
3689 -- the temporary may be subsequently optimized away if the body is a
3690 -- single expression, or if the left-hand side of the assignment is
3691 -- simple enough, i.e. an entity or an explicit dereference of one.
3693 if Ekind (Subp) = E_Function then
3694 if Nkind (Parent (N)) = N_Assignment_Statement
3695 and then Is_Entity_Name (Name (Parent (N)))
3697 Targ := Name (Parent (N));
3699 elsif Nkind (Parent (N)) = N_Assignment_Statement
3700 and then Nkind (Name (Parent (N))) = N_Explicit_Dereference
3701 and then Is_Entity_Name (Prefix (Name (Parent (N))))
3703 Targ := Name (Parent (N));
3706 -- Replace call with temporary and create its declaration
3709 Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
3710 Set_Is_Internal (Temp);
3712 -- For the unconstrained case. the generated temporary has the
3713 -- same constrained declaration as the result variable.
3714 -- It may eventually be possible to remove that temporary and
3715 -- use the result variable directly.
3719 Make_Object_Declaration (Loc,
3720 Defining_Identifier => Temp,
3721 Object_Definition =>
3722 New_Copy_Tree (Object_Definition (Parent (Targ1))));
3724 Replace_Formals (Decl);
3728 Make_Object_Declaration (Loc,
3729 Defining_Identifier => Temp,
3730 Object_Definition =>
3731 New_Occurrence_Of (Ret_Type, Loc));
3733 Set_Etype (Temp, Ret_Type);
3736 Set_No_Initialization (Decl);
3737 Append (Decl, Decls);
3738 Rewrite (N, New_Occurrence_Of (Temp, Loc));
3743 Insert_Actions (N, Decls);
3745 -- Traverse the tree and replace formals with actuals or their thunks.
3746 -- Attach block to tree before analysis and rewriting.
3748 Replace_Formals (Blk);
3749 Set_Parent (Blk, N);
3751 if not Comes_From_Source (Subp)
3757 if Present (Exit_Lab) then
3759 -- If the body was a single expression, the single return statement
3760 -- and the corresponding label are useless.
3764 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
3767 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
3769 Append (Lab_Decl, (Declarations (Blk)));
3770 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
3774 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
3775 -- conflicting private views that Gigi would ignore. If this is
3776 -- predefined unit, analyze with checks off, as is done in the non-
3777 -- inlined run-time units.
3780 I_Flag : constant Boolean := In_Inlined_Body;
3783 In_Inlined_Body := True;
3787 Style : constant Boolean := Style_Check;
3789 Style_Check := False;
3790 Analyze (Blk, Suppress => All_Checks);
3791 Style_Check := Style;
3798 In_Inlined_Body := I_Flag;
3801 if Ekind (Subp) = E_Procedure then
3802 Rewrite_Procedure_Call (N, Blk);
3804 Rewrite_Function_Call (N, Blk);
3806 -- For the unconstrained case, the replacement of the call has been
3807 -- made prior to the complete analysis of the generated declarations.
3808 -- Propagate the proper type now.
3811 if Nkind (N) = N_Identifier then
3812 Set_Etype (N, Etype (Entity (N)));
3814 Set_Etype (N, Etype (Targ1));
3821 -- Cleanup mapping between formals and actuals for other expansions
3823 F := First_Formal (Subp);
3824 while Present (F) loop
3825 Set_Renamed_Object (F, Empty);
3828 end Expand_Inlined_Call;
3830 ----------------------------
3831 -- Expand_N_Function_Call --
3832 ----------------------------
3834 procedure Expand_N_Function_Call (N : Node_Id) is
3835 Typ : constant Entity_Id := Etype (N);
3837 function Returned_By_Reference return Boolean;
3838 -- If the return type is returned through the secondary stack; that is
3839 -- by reference, we don't want to create a temp to force stack checking.
3840 -- ???"sec stack" is not right -- Ada 95 return-by-reference object are
3841 -- returned wherever they are.
3842 -- Shouldn't this function be moved to exp_util???
3844 function Rhs_Of_Assign_Or_Decl (N : Node_Id) return Boolean;
3845 -- If the call is the right side of an assignment or the expression in
3846 -- an object declaration, we don't need to create a temp as the left
3847 -- side will already trigger stack checking if necessary.
3849 -- If the call is a component in an extension aggregate, it will be
3850 -- expanded into assignments as well, so no temporary is needed. This
3851 -- also solves the problem of functions returning types with unknown
3852 -- discriminants, where it is not possible to declare an object of the
3855 ---------------------------
3856 -- Returned_By_Reference --
3857 ---------------------------
3859 function Returned_By_Reference return Boolean is
3863 if Is_Inherently_Limited_Type (Typ) then
3866 elsif Nkind (Parent (N)) /= N_Return_Statement then
3869 elsif Requires_Transient_Scope (Typ) then
3871 -- Verify that the return type of the enclosing function has the
3872 -- same constrained status as that of the expression.
3875 while Ekind (S) /= E_Function loop
3879 return Is_Constrained (Typ) = Is_Constrained (Etype (S));
3883 end Returned_By_Reference;
3885 ---------------------------
3886 -- Rhs_Of_Assign_Or_Decl --
3887 ---------------------------
3889 function Rhs_Of_Assign_Or_Decl (N : Node_Id) return Boolean is
3891 if (Nkind (Parent (N)) = N_Assignment_Statement
3892 and then Expression (Parent (N)) = N)
3894 (Nkind (Parent (N)) = N_Qualified_Expression
3895 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
3896 and then Expression (Parent (Parent (N))) = Parent (N))
3898 (Nkind (Parent (N)) = N_Object_Declaration
3899 and then Expression (Parent (N)) = N)
3901 (Nkind (Parent (N)) = N_Component_Association
3902 and then Expression (Parent (N)) = N
3903 and then Nkind (Parent (Parent (N))) = N_Aggregate
3904 and then Rhs_Of_Assign_Or_Decl (Parent (Parent (N))))
3906 (Nkind (Parent (N)) = N_Extension_Aggregate
3907 and then Is_Private_Type (Etype (Typ)))
3913 end Rhs_Of_Assign_Or_Decl;
3915 -- Start of processing for Expand_N_Function_Call
3918 -- A special check. If stack checking is enabled, and the return type
3919 -- might generate a large temporary, and the call is not the right side
3920 -- of an assignment, then generate an explicit temporary. We do this
3921 -- because otherwise gigi may generate a large temporary on the fly and
3922 -- this can cause trouble with stack checking.
3924 -- This is unnecessary if the call is the expression in an object
3925 -- declaration, or if it appears outside of any library unit. This can
3926 -- only happen if it appears as an actual in a library-level instance,
3927 -- in which case a temporary will be generated for it once the instance
3928 -- itself is installed.
3930 if May_Generate_Large_Temp (Typ)
3931 and then not Rhs_Of_Assign_Or_Decl (N)
3932 and then not Returned_By_Reference
3933 and then Current_Scope /= Standard_Standard
3935 if Stack_Checking_Enabled then
3937 -- Note: it might be thought that it would be OK to use a call to
3938 -- Force_Evaluation here, but that's not good enough, because
3939 -- that can results in a 'Reference construct that may still need
3943 Loc : constant Source_Ptr := Sloc (N);
3944 Temp_Obj : constant Entity_Id :=
3945 Make_Defining_Identifier (Loc,
3946 Chars => New_Internal_Name ('F'));
3947 Temp_Typ : Entity_Id := Typ;
3954 if Is_Tagged_Type (Typ)
3955 and then Present (Controlling_Argument (N))
3957 if Nkind (Parent (N)) /= N_Procedure_Call_Statement
3958 and then Nkind (Parent (N)) /= N_Function_Call
3960 -- If this is a tag-indeterminate call, the object must
3963 if Is_Tag_Indeterminate (N) then
3964 Temp_Typ := Class_Wide_Type (Typ);
3968 -- If this is a dispatching call that is itself the
3969 -- controlling argument of an enclosing call, the
3970 -- nominal subtype of the object that replaces it must
3971 -- be classwide, so that dispatching will take place
3972 -- properly. If it is not a controlling argument, the
3973 -- object is not classwide.
3975 Proc := Entity (Name (Parent (N)));
3977 F := First_Formal (Proc);
3978 A := First_Actual (Parent (N));
3984 if Is_Controlling_Formal (F) then
3985 Temp_Typ := Class_Wide_Type (Typ);
3991 Make_Object_Declaration (Loc,
3992 Defining_Identifier => Temp_Obj,
3993 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
3994 Constant_Present => True,
3995 Expression => Relocate_Node (N));
3996 Set_Assignment_OK (Decl);
3998 Insert_Actions (N, New_List (Decl));
3999 Rewrite (N, New_Occurrence_Of (Temp_Obj, Loc));
4003 -- If stack-checking is not enabled, increment serial number
4004 -- for internal names, so that subsequent symbols are consistent
4005 -- with and without stack-checking.
4007 Synchronize_Serial_Number;
4009 -- Now we can expand the call with consistent symbol names
4014 -- Normal case, expand the call
4019 end Expand_N_Function_Call;
4021 ---------------------------------------
4022 -- Expand_N_Procedure_Call_Statement --
4023 ---------------------------------------
4025 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
4028 end Expand_N_Procedure_Call_Statement;
4030 ------------------------------
4031 -- Expand_N_Subprogram_Body --
4032 ------------------------------
4034 -- Add poll call if ATC polling is enabled, unless the body will be
4035 -- inlined by the back-end.
4037 -- Add dummy push/pop label nodes at start and end to clear any local
4038 -- exception indications if local-exception-to-goto optimization active.
4040 -- Add return statement if last statement in body is not a return statement
4041 -- (this makes things easier on Gigi which does not want to have to handle
4042 -- a missing return).
4044 -- Add call to Activate_Tasks if body is a task activator
4046 -- Deal with possible detection of infinite recursion
4048 -- Eliminate body completely if convention stubbed
4050 -- Encode entity names within body, since we will not need to reference
4051 -- these entities any longer in the front end.
4053 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
4055 -- Reset Pure indication if any parameter has root type System.Address
4059 procedure Expand_N_Subprogram_Body (N : Node_Id) is
4060 Loc : constant Source_Ptr := Sloc (N);
4061 H : constant Node_Id := Handled_Statement_Sequence (N);
4062 Body_Id : Entity_Id;
4063 Spec_Id : Entity_Id;
4070 procedure Add_Return (S : List_Id);
4071 -- Append a return statement to the statement sequence S if the last
4072 -- statement is not already a return or a goto statement. Note that
4073 -- the latter test is not critical, it does not matter if we add a
4074 -- few extra returns, since they get eliminated anyway later on.
4080 procedure Add_Return (S : List_Id) is
4085 -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
4086 -- not relevant in this context since they are not executable.
4088 Last_Stm := Last (S);
4089 while Nkind (Last_Stm) in N_Pop_xxx_Label loop
4093 -- Now insert return unless last statement is a transfer
4095 if not Is_Transfer (Last_Stm) then
4097 -- The source location for the return is the end label of the
4098 -- procedure if present. Otherwise use the sloc of the last
4099 -- statement in the list. If the list comes from a generated
4100 -- exception handler and we are not debugging generated code,
4101 -- all the statements within the handler are made invisible
4104 if Nkind (Parent (S)) = N_Exception_Handler
4105 and then not Comes_From_Source (Parent (S))
4107 Loc := Sloc (Last_Stm);
4109 elsif Present (End_Label (H)) then
4110 Loc := Sloc (End_Label (H));
4113 Loc := Sloc (Last_Stm);
4116 Append_To (S, Make_Return_Statement (Loc));
4120 -- Start of processing for Expand_N_Subprogram_Body
4123 -- Set L to either the list of declarations if present, or
4124 -- to the list of statements if no declarations are present.
4125 -- This is used to insert new stuff at the start.
4127 if Is_Non_Empty_List (Declarations (N)) then
4128 L := Declarations (N);
4130 L := Statements (H);
4133 -- If local-exception-to-goto optimization active, insert dummy push
4134 -- statements at start, and dummy pop statements at end.
4136 if (Debug_Flag_Dot_G
4137 or else Restriction_Active (No_Exception_Propagation))
4138 and then Is_Non_Empty_List (L)
4141 FS : constant Node_Id := First (L);
4142 FL : constant Source_Ptr := Sloc (FS);
4147 -- LS points to either last statement, if statements are present
4148 -- or to the last declaration if there are no statements present.
4149 -- It is the node after which the pop's are generated.
4151 if Is_Non_Empty_List (Statements (H)) then
4152 LS := Last (Statements (H));
4159 Insert_List_Before_And_Analyze (FS, New_List (
4160 Make_Push_Constraint_Error_Label (FL),
4161 Make_Push_Program_Error_Label (FL),
4162 Make_Push_Storage_Error_Label (FL)));
4164 Insert_List_After_And_Analyze (LS, New_List (
4165 Make_Pop_Constraint_Error_Label (LL),
4166 Make_Pop_Program_Error_Label (LL),
4167 Make_Pop_Storage_Error_Label (LL)));
4171 -- Find entity for subprogram
4173 Body_Id := Defining_Entity (N);
4175 if Present (Corresponding_Spec (N)) then
4176 Spec_Id := Corresponding_Spec (N);
4181 -- Need poll on entry to subprogram if polling enabled. We only do this
4182 -- for non-empty subprograms, since it does not seem necessary to poll
4183 -- for a dummy null subprogram. Do not add polling point if calls to
4184 -- this subprogram will be inlined by the back-end, to avoid repeated
4185 -- polling points in nested inlinings.
4187 if Is_Non_Empty_List (L) then
4188 if Is_Inlined (Spec_Id)
4189 and then Front_End_Inlining
4190 and then Optimization_Level > 1
4194 Generate_Poll_Call (First (L));
4198 -- If this is a Pure function which has any parameters whose root
4199 -- type is System.Address, reset the Pure indication, since it will
4200 -- likely cause incorrect code to be generated as the parameter is
4201 -- probably a pointer, and the fact that the same pointer is passed
4202 -- does not mean that the same value is being referenced.
4204 -- Note that if the programmer gave an explicit Pure_Function pragma,
4205 -- then we believe the programmer, and leave the subprogram Pure.
4207 -- This code should probably be at the freeze point, so that it
4208 -- happens even on a -gnatc (or more importantly -gnatt) compile
4209 -- so that the semantic tree has Is_Pure set properly ???
4211 if Is_Pure (Spec_Id)
4212 and then Is_Subprogram (Spec_Id)
4213 and then not Has_Pragma_Pure_Function (Spec_Id)
4219 F := First_Formal (Spec_Id);
4220 while Present (F) loop
4221 if Is_Descendent_Of_Address (Etype (F)) then
4222 Set_Is_Pure (Spec_Id, False);
4224 if Spec_Id /= Body_Id then
4225 Set_Is_Pure (Body_Id, False);
4236 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
4238 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
4243 -- Loop through formals
4245 F := First_Formal (Spec_Id);
4246 while Present (F) loop
4247 if Is_Scalar_Type (Etype (F))
4248 and then Ekind (F) = E_Out_Parameter
4250 -- Insert the initialization. We turn off validity checks
4251 -- for this assignment, since we do not want any check on
4252 -- the initial value itself (which may well be invalid).
4254 Insert_Before_And_Analyze (First (L),
4255 Make_Assignment_Statement (Loc,
4256 Name => New_Occurrence_Of (F, Loc),
4257 Expression => Get_Simple_Init_Val (Etype (F), Loc)),
4258 Suppress => Validity_Check);
4266 Scop := Scope (Spec_Id);
4268 -- Add discriminal renamings to protected subprograms. Install new
4269 -- discriminals for expansion of the next subprogram of this protected
4272 if Is_List_Member (N)
4273 and then Present (Parent (List_Containing (N)))
4274 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
4276 Add_Discriminal_Declarations
4277 (Declarations (N), Scop, Name_uObject, Loc);
4278 Add_Private_Declarations (Declarations (N), Scop, Name_uObject, Loc);
4280 -- Associate privals and discriminals with the next protected
4281 -- operation body to be expanded. These are used to expand references
4282 -- to private data objects and discriminants, respectively.
4284 Next_Op := Next_Protected_Operation (N);
4286 if Present (Next_Op) then
4287 Dec := Parent (Base_Type (Scop));
4288 Set_Privals (Dec, Next_Op, Loc);
4289 Set_Discriminals (Dec);
4293 -- Clear out statement list for stubbed procedure
4295 if Present (Corresponding_Spec (N)) then
4296 Set_Elaboration_Flag (N, Spec_Id);
4298 if Convention (Spec_Id) = Convention_Stubbed
4299 or else Is_Eliminated (Spec_Id)
4301 Set_Declarations (N, Empty_List);
4302 Set_Handled_Statement_Sequence (N,
4303 Make_Handled_Sequence_Of_Statements (Loc,
4304 Statements => New_List (
4305 Make_Null_Statement (Loc))));
4310 -- Returns_By_Ref flag is normally set when the subprogram is frozen
4311 -- but subprograms with no specs are not frozen.
4314 Typ : constant Entity_Id := Etype (Spec_Id);
4315 Utyp : constant Entity_Id := Underlying_Type (Typ);
4318 if not Acts_As_Spec (N)
4319 and then Nkind (Parent (Parent (Spec_Id))) /=
4320 N_Subprogram_Body_Stub
4324 elsif Is_Inherently_Limited_Type (Typ) then
4325 Set_Returns_By_Ref (Spec_Id);
4327 elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
4328 Set_Returns_By_Ref (Spec_Id);
4332 -- For a procedure, we add a return for all possible syntactic ends
4333 -- of the subprogram. Note that reanalysis is not necessary in this
4334 -- case since it would require a lot of work and accomplish nothing.
4336 if Ekind (Spec_Id) = E_Procedure
4337 or else Ekind (Spec_Id) = E_Generic_Procedure
4339 Add_Return (Statements (H));
4341 if Present (Exception_Handlers (H)) then
4342 Except_H := First_Non_Pragma (Exception_Handlers (H));
4343 while Present (Except_H) loop
4344 Add_Return (Statements (Except_H));
4345 Next_Non_Pragma (Except_H);
4349 -- For a function, we must deal with the case where there is at least
4350 -- one missing return. What we do is to wrap the entire body of the
4351 -- function in a block:
4364 -- raise Program_Error;
4367 -- This approach is necessary because the raise must be signalled
4368 -- to the caller, not handled by any local handler (RM 6.4(11)).
4370 -- Note: we do not need to analyze the constructed sequence here,
4371 -- since it has no handler, and an attempt to analyze the handled
4372 -- statement sequence twice is risky in various ways (e.g. the
4373 -- issue of expanding cleanup actions twice).
4375 elsif Has_Missing_Return (Spec_Id) then
4377 Hloc : constant Source_Ptr := Sloc (H);
4378 Blok : constant Node_Id :=
4379 Make_Block_Statement (Hloc,
4380 Handled_Statement_Sequence => H);
4381 Rais : constant Node_Id :=
4382 Make_Raise_Program_Error (Hloc,
4383 Reason => PE_Missing_Return);
4386 Set_Handled_Statement_Sequence (N,
4387 Make_Handled_Sequence_Of_Statements (Hloc,
4388 Statements => New_List (Blok, Rais)));
4390 Push_Scope (Spec_Id);
4397 -- If subprogram contains a parameterless recursive call, then we may
4398 -- have an infinite recursion, so see if we can generate code to check
4399 -- for this possibility if storage checks are not suppressed.
4401 if Ekind (Spec_Id) = E_Procedure
4402 and then Has_Recursive_Call (Spec_Id)
4403 and then not Storage_Checks_Suppressed (Spec_Id)
4405 Detect_Infinite_Recursion (N, Spec_Id);
4408 -- Finally, if we are in Normalize_Scalars mode, then any scalar out
4409 -- parameters must be initialized to the appropriate default value.
4411 if Ekind (Spec_Id) = E_Procedure and then Normalize_Scalars then
4418 Formal := First_Formal (Spec_Id);
4419 while Present (Formal) loop
4420 Floc := Sloc (Formal);
4422 if Ekind (Formal) = E_Out_Parameter
4423 and then Is_Scalar_Type (Etype (Formal))
4426 Make_Assignment_Statement (Floc,
4427 Name => New_Occurrence_Of (Formal, Floc),
4429 Get_Simple_Init_Val (Etype (Formal), Floc));
4430 Prepend (Stm, Declarations (N));
4434 Next_Formal (Formal);
4439 -- Set to encode entity names in package body before gigi is called
4441 Qualify_Entity_Names (N);
4442 end Expand_N_Subprogram_Body;
4444 -----------------------------------
4445 -- Expand_N_Subprogram_Body_Stub --
4446 -----------------------------------
4448 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
4450 if Present (Corresponding_Body (N)) then
4451 Expand_N_Subprogram_Body (
4452 Unit_Declaration_Node (Corresponding_Body (N)));
4454 end Expand_N_Subprogram_Body_Stub;
4456 -------------------------------------
4457 -- Expand_N_Subprogram_Declaration --
4458 -------------------------------------
4460 -- If the declaration appears within a protected body, it is a private
4461 -- operation of the protected type. We must create the corresponding
4462 -- protected subprogram an associated formals. For a normal protected
4463 -- operation, this is done when expanding the protected type declaration.
4465 -- If the declaration is for a null procedure, emit null body
4467 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
4468 Loc : constant Source_Ptr := Sloc (N);
4469 Subp : constant Entity_Id := Defining_Entity (N);
4470 Scop : constant Entity_Id := Scope (Subp);
4471 Prot_Decl : Node_Id;
4473 Prot_Id : Entity_Id;
4476 -- Deal with case of protected subprogram. Do not generate protected
4477 -- operation if operation is flagged as eliminated.
4479 if Is_List_Member (N)
4480 and then Present (Parent (List_Containing (N)))
4481 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
4482 and then Is_Protected_Type (Scop)
4484 if No (Protected_Body_Subprogram (Subp))
4485 and then not Is_Eliminated (Subp)
4488 Make_Subprogram_Declaration (Loc,
4490 Build_Protected_Sub_Specification
4491 (N, Scop, Unprotected_Mode));
4493 -- The protected subprogram is declared outside of the protected
4494 -- body. Given that the body has frozen all entities so far, we
4495 -- analyze the subprogram and perform freezing actions explicitly.
4496 -- If the body is a subunit, the insertion point is before the
4497 -- stub in the parent.
4499 Prot_Bod := Parent (List_Containing (N));
4501 if Nkind (Parent (Prot_Bod)) = N_Subunit then
4502 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
4505 Insert_Before (Prot_Bod, Prot_Decl);
4506 Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
4508 Push_Scope (Scope (Scop));
4509 Analyze (Prot_Decl);
4510 Create_Extra_Formals (Prot_Id);
4511 Set_Protected_Body_Subprogram (Subp, Prot_Id);
4515 -- Ada 2005 (AI-348): Generation of the null body
4517 elsif Nkind (Specification (N)) = N_Procedure_Specification
4518 and then Null_Present (Specification (N))
4521 Bod : constant Node_Id :=
4522 Make_Subprogram_Body (Loc,
4524 New_Copy_Tree (Specification (N)),
4525 Declarations => New_List,
4526 Handled_Statement_Sequence =>
4527 Make_Handled_Sequence_Of_Statements (Loc,
4528 Statements => New_List (Make_Null_Statement (Loc))));
4530 Set_Body_To_Inline (N, Bod);
4531 Insert_After (N, Bod);
4534 -- Corresponding_Spec isn't being set by Analyze_Subprogram_Body,
4535 -- evidently because Set_Has_Completion is called earlier for null
4536 -- procedures in Analyze_Subprogram_Declaration, so we force its
4537 -- setting here. If the setting of Has_Completion is not set
4538 -- earlier, then it can result in missing body errors if other
4539 -- errors were already reported (since expansion is turned off).
4541 -- Should creation of the empty body be moved to the analyzer???
4543 Set_Corresponding_Spec (Bod, Defining_Entity (Specification (N)));
4546 end Expand_N_Subprogram_Declaration;
4548 ---------------------------------------
4549 -- Expand_Protected_Object_Reference --
4550 ---------------------------------------
4552 function Expand_Protected_Object_Reference
4554 Scop : Entity_Id) return Node_Id
4556 Loc : constant Source_Ptr := Sloc (N);
4564 Make_Identifier (Loc,
4565 Chars => Name_uObject);
4566 Set_Etype (Rec, Corresponding_Record_Type (Scop));
4568 -- Find enclosing protected operation, and retrieve its first parameter,
4569 -- which denotes the enclosing protected object. If the enclosing
4570 -- operation is an entry, we are immediately within the protected body,
4571 -- and we can retrieve the object from the service entries procedure. A
4572 -- barrier function has has the same signature as an entry. A barrier
4573 -- function is compiled within the protected object, but unlike
4574 -- protected operations its never needs locks, so that its protected
4575 -- body subprogram points to itself.
4577 Proc := Current_Scope;
4578 while Present (Proc)
4579 and then Scope (Proc) /= Scop
4581 Proc := Scope (Proc);
4584 Corr := Protected_Body_Subprogram (Proc);
4588 -- Previous error left expansion incomplete.
4589 -- Nothing to do on this call.
4596 (First (Parameter_Specifications (Parent (Corr))));
4598 if Is_Subprogram (Proc)
4599 and then Proc /= Corr
4601 -- Protected function or procedure
4603 Set_Entity (Rec, Param);
4605 -- Rec is a reference to an entity which will not be in scope when
4606 -- the call is reanalyzed, and needs no further analysis.
4611 -- Entry or barrier function for entry body. The first parameter of
4612 -- the entry body procedure is pointer to the object. We create a
4613 -- local variable of the proper type, duplicating what is done to
4614 -- define _object later on.
4618 Obj_Ptr : constant Entity_Id := Make_Defining_Identifier (Loc,
4620 New_Internal_Name ('T'));
4624 Make_Full_Type_Declaration (Loc,
4625 Defining_Identifier => Obj_Ptr,
4627 Make_Access_To_Object_Definition (Loc,
4628 Subtype_Indication =>
4630 (Corresponding_Record_Type (Scop), Loc))));
4632 Insert_Actions (N, Decls);
4633 Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
4636 Make_Explicit_Dereference (Loc,
4637 Unchecked_Convert_To (Obj_Ptr,
4638 New_Occurrence_Of (Param, Loc)));
4640 -- Analyze new actual. Other actuals in calls are already analyzed
4641 -- and the list of actuals is not reanalyzed after rewriting.
4643 Set_Parent (Rec, N);
4649 end Expand_Protected_Object_Reference;
4651 --------------------------------------
4652 -- Expand_Protected_Subprogram_Call --
4653 --------------------------------------
4655 procedure Expand_Protected_Subprogram_Call
4663 -- If the protected object is not an enclosing scope, this is
4664 -- an inter-object function call. Inter-object procedure
4665 -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
4666 -- The call is intra-object only if the subprogram being
4667 -- called is in the protected body being compiled, and if the
4668 -- protected object in the call is statically the enclosing type.
4669 -- The object may be an component of some other data structure,
4670 -- in which case this must be handled as an inter-object call.
4672 if not In_Open_Scopes (Scop)
4673 or else not Is_Entity_Name (Name (N))
4675 if Nkind (Name (N)) = N_Selected_Component then
4676 Rec := Prefix (Name (N));
4679 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
4680 Rec := Prefix (Prefix (Name (N)));
4683 Build_Protected_Subprogram_Call (N,
4684 Name => New_Occurrence_Of (Subp, Sloc (N)),
4685 Rec => Convert_Concurrent (Rec, Etype (Rec)),
4689 Rec := Expand_Protected_Object_Reference (N, Scop);
4695 Build_Protected_Subprogram_Call (N,
4704 -- If it is a function call it can appear in elaboration code and
4705 -- the called entity must be frozen here.
4707 if Ekind (Subp) = E_Function then
4708 Freeze_Expression (Name (N));
4710 end Expand_Protected_Subprogram_Call;
4712 --------------------------------
4713 -- Is_Build_In_Place_Function --
4714 --------------------------------
4716 function Is_Build_In_Place_Function (E : Entity_Id) return Boolean is
4718 -- For now we test whether E denotes a function or access-to-function
4719 -- type whose result subtype is inherently limited. Later this test may
4720 -- be revised to allow composite nonlimited types. Functions with a
4721 -- foreign convention or whose result type has a foreign convention
4724 if Ekind (E) = E_Function
4725 or else Ekind (E) = E_Generic_Function
4726 or else (Ekind (E) = E_Subprogram_Type
4727 and then Etype (E) /= Standard_Void_Type)
4729 -- Note: If you have Convention (C) on an inherently limited type,
4730 -- you're on your own. That is, the C code will have to be carefully
4731 -- written to know about the Ada conventions.
4733 if Has_Foreign_Convention (E)
4734 or else Has_Foreign_Convention (Etype (E))
4738 -- If the return type is a limited interface it has to be treated
4739 -- as a return in place, even if the actual object is some non-
4740 -- limited descendant.
4742 elsif Is_Limited_Interface (Etype (E)) then
4746 return Is_Inherently_Limited_Type (Etype (E))
4747 and then Ada_Version >= Ada_05
4748 and then not Debug_Flag_Dot_L;
4754 end Is_Build_In_Place_Function;
4756 -------------------------------------
4757 -- Is_Build_In_Place_Function_Call --
4758 -------------------------------------
4760 function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean is
4761 Exp_Node : Node_Id := N;
4762 Function_Id : Entity_Id;
4765 if Nkind (Exp_Node) = N_Qualified_Expression then
4766 Exp_Node := Expression (N);
4769 if Nkind (Exp_Node) /= N_Function_Call then
4773 if Is_Entity_Name (Name (Exp_Node)) then
4774 Function_Id := Entity (Name (Exp_Node));
4776 elsif Nkind (Name (Exp_Node)) = N_Explicit_Dereference then
4777 Function_Id := Etype (Name (Exp_Node));
4780 return Is_Build_In_Place_Function (Function_Id);
4782 end Is_Build_In_Place_Function_Call;
4784 ---------------------------------------
4785 -- Is_Build_In_Place_Function_Return --
4786 ---------------------------------------
4788 function Is_Build_In_Place_Function_Return (N : Node_Id) return Boolean is
4790 if Nkind (N) = N_Return_Statement
4791 or else Nkind (N) = N_Extended_Return_Statement
4793 return Is_Build_In_Place_Function
4794 (Return_Applies_To (Return_Statement_Entity (N)));
4798 end Is_Build_In_Place_Function_Return;
4800 -----------------------
4801 -- Freeze_Subprogram --
4802 -----------------------
4804 procedure Freeze_Subprogram (N : Node_Id) is
4805 Loc : constant Source_Ptr := Sloc (N);
4807 procedure Register_Predefined_DT_Entry (Prim : Entity_Id);
4808 -- (Ada 2005): Register a predefined primitive in all the secondary
4809 -- dispatch tables of its primitive type.
4811 ----------------------------------
4812 -- Register_Predefined_DT_Entry --
4813 ----------------------------------
4815 procedure Register_Predefined_DT_Entry (Prim : Entity_Id) is
4816 Iface_DT_Ptr : Elmt_Id;
4817 Tagged_Typ : Entity_Id;
4818 Thunk_Id : Entity_Id;
4819 Thunk_Code : Node_Id;
4822 Tagged_Typ := Find_Dispatching_Type (Prim);
4824 if No (Access_Disp_Table (Tagged_Typ))
4825 or else not Has_Abstract_Interfaces (Tagged_Typ)
4826 or else not RTE_Available (RE_Interface_Tag)
4827 or else Restriction_Active (No_Dispatching_Calls)
4832 -- Skip the first access-to-dispatch-table pointer since it leads
4833 -- to the primary dispatch table. We are only concerned with the
4834 -- secondary dispatch table pointers. Note that the access-to-
4835 -- dispatch-table pointer corresponds to the first implemented
4836 -- interface retrieved below.
4839 Next_Elmt (First_Elmt (Access_Disp_Table (Tagged_Typ)));
4841 while Present (Iface_DT_Ptr)
4842 and then Ekind (Node (Iface_DT_Ptr)) = E_Constant
4844 Expand_Interface_Thunk
4846 Thunk_Alias => Prim,
4847 Thunk_Id => Thunk_Id,
4848 Thunk_Code => Thunk_Code);
4850 if Present (Thunk_Code) then
4851 Insert_Actions (N, New_List (
4854 Build_Set_Predefined_Prim_Op_Address (Loc,
4855 Tag_Node => New_Reference_To (Node (Iface_DT_Ptr), Loc),
4856 Position => DT_Position (Prim),
4858 Make_Attribute_Reference (Loc,
4859 Prefix => New_Reference_To (Thunk_Id, Loc),
4860 Attribute_Name => Name_Address))));
4863 Next_Elmt (Iface_DT_Ptr);
4865 end Register_Predefined_DT_Entry;
4869 Subp : constant Entity_Id := Entity (N);
4870 Typ : constant Entity_Id := Etype (Subp);
4871 Utyp : constant Entity_Id := Underlying_Type (Typ);
4874 if not Static_Dispatch_Tables then
4876 E : constant Entity_Id := Subp;
4880 -- We assume that imported CPP primitives correspond with objects
4881 -- whose constructor is in the CPP side (and therefore we don't
4882 -- need to generate code to register them in the dispatch table).
4885 and then Convention (E) = Convention_CPP
4890 -- When a primitive is frozen, enter its name in the corresponding
4891 -- dispatch table. If the DTC_Entity field is not set this is
4892 -- an overridden primitive that can be ignored. We suppress the
4893 -- initialization of the dispatch table entry when VM_Target
4894 -- because the dispatching mechanism is handled internally by
4897 if Is_Dispatching_Operation (E)
4898 and then not Is_Abstract_Subprogram (E)
4899 and then Present (DTC_Entity (E))
4900 and then VM_Target = No_VM
4901 and then not Is_CPP_Class (Scope (DTC_Entity (E)))
4903 Check_Overriding_Operation (E);
4905 -- Register the primitive in its dispatch table if we are not
4906 -- compiling under No_Dispatching_Calls restriction
4908 if not Restriction_Active (No_Dispatching_Calls)
4909 and then RTE_Available (RE_Tag)
4911 Typ := Scope (DTC_Entity (E));
4913 if not Is_Interface (Typ)
4914 or else Present (Abstract_Interface_Alias (E))
4916 if Is_Predefined_Dispatching_Operation (E) then
4917 Register_Predefined_DT_Entry (E);
4920 Register_Primitive (Loc,
4931 -- Handle private overriden primitives
4933 if Is_Dispatching_Operation (Subp)
4934 and then not Is_Abstract_Subprogram (Subp)
4935 and then Present (DTC_Entity (Subp))
4936 and then VM_Target = No_VM
4937 and then not Is_CPP_Class (Scope (DTC_Entity (Subp)))
4939 Check_Overriding_Operation (Subp);
4943 -- Mark functions that return by reference. Note that it cannot be part
4944 -- of the normal semantic analysis of the spec since the underlying
4945 -- returned type may not be known yet (for private types).
4947 if Is_Inherently_Limited_Type (Typ) then
4948 Set_Returns_By_Ref (Subp);
4950 elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
4951 Set_Returns_By_Ref (Subp);
4953 end Freeze_Subprogram;
4955 -------------------------------------------
4956 -- Make_Build_In_Place_Call_In_Allocator --
4957 -------------------------------------------
4959 procedure Make_Build_In_Place_Call_In_Allocator
4960 (Allocator : Node_Id;
4961 Function_Call : Node_Id)
4964 Func_Call : Node_Id := Function_Call;
4965 Function_Id : Entity_Id;
4966 Result_Subt : Entity_Id;
4967 Acc_Type : constant Entity_Id := Etype (Allocator);
4968 New_Allocator : Node_Id;
4969 Return_Obj_Access : Entity_Id;
4972 if Nkind (Func_Call) = N_Qualified_Expression then
4973 Func_Call := Expression (Func_Call);
4976 Loc := Sloc (Function_Call);
4978 if Is_Entity_Name (Name (Func_Call)) then
4979 Function_Id := Entity (Name (Func_Call));
4981 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
4982 Function_Id := Etype (Name (Func_Call));
4985 raise Program_Error;
4988 Result_Subt := Etype (Function_Id);
4990 -- When the result subtype is constrained, the return object must be
4991 -- allocated on the caller side, and access to it is passed to the
4994 -- Here and in related routines, we must examine the full view of the
4995 -- type, because the view at the point of call may differ from that
4996 -- that in the function body, and the expansion mechanism depends on
4997 -- the characteristics of the full view.
4999 if Is_Constrained (Underlying_Type (Result_Subt)) then
5001 -- Replace the initialized allocator of form "new T'(Func (...))"
5002 -- with an uninitialized allocator of form "new T", where T is the
5003 -- result subtype of the called function. The call to the function
5004 -- is handled separately further below.
5007 Make_Allocator (Loc, New_Reference_To (Result_Subt, Loc));
5009 Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
5010 Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
5011 Set_No_Initialization (New_Allocator);
5013 Rewrite (Allocator, New_Allocator);
5015 -- Create a new access object and initialize it to the result of the
5016 -- new uninitialized allocator.
5018 Return_Obj_Access :=
5019 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
5020 Set_Etype (Return_Obj_Access, Acc_Type);
5022 Insert_Action (Allocator,
5023 Make_Object_Declaration (Loc,
5024 Defining_Identifier => Return_Obj_Access,
5025 Object_Definition => New_Reference_To (Acc_Type, Loc),
5026 Expression => Relocate_Node (Allocator)));
5028 -- When the function has a controlling result, an allocation-form
5029 -- parameter must be passed indicating that the caller is allocating
5030 -- the result object. This is needed because such a function can be
5031 -- called as a dispatching operation and must be treated similarly
5032 -- to functions with unconstrained result subtypes.
5034 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5035 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5037 Add_Final_List_Actual_To_Build_In_Place_Call
5038 (Func_Call, Function_Id, Acc_Type);
5040 Add_Task_Actuals_To_Build_In_Place_Call
5041 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
5043 -- Add an implicit actual to the function call that provides access
5044 -- to the allocated object. An unchecked conversion to the (specific)
5045 -- result subtype of the function is inserted to handle cases where
5046 -- the access type of the allocator has a class-wide designated type.
5048 Add_Access_Actual_To_Build_In_Place_Call
5051 Make_Unchecked_Type_Conversion (Loc,
5052 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5054 Make_Explicit_Dereference (Loc,
5055 Prefix => New_Reference_To (Return_Obj_Access, Loc))));
5057 -- When the result subtype is unconstrained, the function itself must
5058 -- perform the allocation of the return object, so we pass parameters
5059 -- indicating that. We don't yet handle the case where the allocation
5060 -- must be done in a user-defined storage pool, which will require
5061 -- passing another actual or two to provide allocation/deallocation
5066 -- Pass an allocation parameter indicating that the function should
5067 -- allocate its result on the heap.
5069 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5070 (Func_Call, Function_Id, Alloc_Form => Global_Heap);
5072 Add_Final_List_Actual_To_Build_In_Place_Call
5073 (Func_Call, Function_Id, Acc_Type);
5075 Add_Task_Actuals_To_Build_In_Place_Call
5076 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
5078 -- The caller does not provide the return object in this case, so we
5079 -- have to pass null for the object access actual.
5081 Add_Access_Actual_To_Build_In_Place_Call
5082 (Func_Call, Function_Id, Return_Object => Empty);
5085 -- Finally, replace the allocator node with a reference to the result
5086 -- of the function call itself (which will effectively be an access
5087 -- to the object created by the allocator).
5089 Rewrite (Allocator, Make_Reference (Loc, Relocate_Node (Function_Call)));
5090 Analyze_And_Resolve (Allocator, Acc_Type);
5091 end Make_Build_In_Place_Call_In_Allocator;
5093 ---------------------------------------------------
5094 -- Make_Build_In_Place_Call_In_Anonymous_Context --
5095 ---------------------------------------------------
5097 procedure Make_Build_In_Place_Call_In_Anonymous_Context
5098 (Function_Call : Node_Id)
5101 Func_Call : Node_Id := Function_Call;
5102 Function_Id : Entity_Id;
5103 Result_Subt : Entity_Id;
5104 Return_Obj_Id : Entity_Id;
5105 Return_Obj_Decl : Entity_Id;
5108 if Nkind (Func_Call) = N_Qualified_Expression then
5109 Func_Call := Expression (Func_Call);
5112 Loc := Sloc (Function_Call);
5114 if Is_Entity_Name (Name (Func_Call)) then
5115 Function_Id := Entity (Name (Func_Call));
5117 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5118 Function_Id := Etype (Name (Func_Call));
5121 raise Program_Error;
5124 Result_Subt := Etype (Function_Id);
5126 -- When the result subtype is constrained, an object of the subtype is
5127 -- declared and an access value designating it is passed as an actual.
5129 if Is_Constrained (Underlying_Type (Result_Subt)) then
5131 -- Create a temporary object to hold the function result
5134 Make_Defining_Identifier (Loc,
5135 Chars => New_Internal_Name ('R'));
5136 Set_Etype (Return_Obj_Id, Result_Subt);
5139 Make_Object_Declaration (Loc,
5140 Defining_Identifier => Return_Obj_Id,
5141 Aliased_Present => True,
5142 Object_Definition => New_Reference_To (Result_Subt, Loc));
5144 Set_No_Initialization (Return_Obj_Decl);
5146 Insert_Action (Func_Call, Return_Obj_Decl);
5148 -- When the function has a controlling result, an allocation-form
5149 -- parameter must be passed indicating that the caller is allocating
5150 -- the result object. This is needed because such a function can be
5151 -- called as a dispatching operation and must be treated similarly
5152 -- to functions with unconstrained result subtypes.
5154 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5155 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5157 Add_Final_List_Actual_To_Build_In_Place_Call
5158 (Func_Call, Function_Id, Acc_Type => Empty);
5160 Add_Task_Actuals_To_Build_In_Place_Call
5161 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5163 -- Add an implicit actual to the function call that provides access
5164 -- to the caller's return object.
5166 Add_Access_Actual_To_Build_In_Place_Call
5167 (Func_Call, Function_Id, New_Reference_To (Return_Obj_Id, Loc));
5169 -- When the result subtype is unconstrained, the function must allocate
5170 -- the return object in the secondary stack, so appropriate implicit
5171 -- parameters are added to the call to indicate that. A transient
5172 -- scope is established to ensure eventual cleanup of the result.
5176 -- Pass an allocation parameter indicating that the function should
5177 -- allocate its result on the secondary stack.
5179 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5180 (Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
5182 Add_Final_List_Actual_To_Build_In_Place_Call
5183 (Func_Call, Function_Id, Acc_Type => Empty);
5185 Add_Task_Actuals_To_Build_In_Place_Call
5186 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5188 -- Pass a null value to the function since no return object is
5189 -- available on the caller side.
5191 Add_Access_Actual_To_Build_In_Place_Call
5192 (Func_Call, Function_Id, Empty);
5194 Establish_Transient_Scope (Func_Call, Sec_Stack => True);
5196 end Make_Build_In_Place_Call_In_Anonymous_Context;
5198 ---------------------------------------------------
5199 -- Make_Build_In_Place_Call_In_Assignment --
5200 ---------------------------------------------------
5202 procedure Make_Build_In_Place_Call_In_Assignment
5204 Function_Call : Node_Id)
5206 Lhs : constant Node_Id := Name (Assign);
5208 Func_Call : Node_Id := Function_Call;
5209 Function_Id : Entity_Id;
5210 Result_Subt : Entity_Id;
5211 Ref_Type : Entity_Id;
5212 Ptr_Typ_Decl : Node_Id;
5217 if Nkind (Func_Call) = N_Qualified_Expression then
5218 Func_Call := Expression (Func_Call);
5221 Loc := Sloc (Function_Call);
5223 if Is_Entity_Name (Name (Func_Call)) then
5224 Function_Id := Entity (Name (Func_Call));
5226 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5227 Function_Id := Etype (Name (Func_Call));
5230 raise Program_Error;
5233 Result_Subt := Etype (Function_Id);
5235 -- When the result subtype is unconstrained, an additional actual must
5236 -- be passed to indicate that the caller is providing the return object.
5237 -- This parameter must also be passed when the called function has a
5238 -- controlling result, because dispatching calls to the function needs
5239 -- to be treated effectively the same as calls to class-wide functions.
5241 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5242 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5244 Add_Final_List_Actual_To_Build_In_Place_Call
5245 (Func_Call, Function_Id, Acc_Type => Empty);
5247 Add_Task_Actuals_To_Build_In_Place_Call
5248 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5250 -- Add an implicit actual to the function call that provides access to
5251 -- the caller's return object.
5253 Add_Access_Actual_To_Build_In_Place_Call
5256 Make_Unchecked_Type_Conversion (Loc,
5257 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5258 Expression => Relocate_Node (Lhs)));
5260 -- Create an access type designating the function's result subtype
5263 Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
5266 Make_Full_Type_Declaration (Loc,
5267 Defining_Identifier => Ref_Type,
5269 Make_Access_To_Object_Definition (Loc,
5270 All_Present => True,
5271 Subtype_Indication =>
5272 New_Reference_To (Result_Subt, Loc)));
5274 Insert_After_And_Analyze (Assign, Ptr_Typ_Decl);
5276 -- Finally, create an access object initialized to a reference to the
5280 Make_Defining_Identifier (Loc,
5281 Chars => New_Internal_Name ('R'));
5282 Set_Etype (Def_Id, Ref_Type);
5285 Make_Reference (Loc,
5286 Prefix => Relocate_Node (Func_Call));
5288 Insert_After_And_Analyze (Ptr_Typ_Decl,
5289 Make_Object_Declaration (Loc,
5290 Defining_Identifier => Def_Id,
5291 Object_Definition => New_Reference_To (Ref_Type, Loc),
5292 Expression => New_Expr));
5294 Rewrite (Assign, Make_Null_Statement (Loc));
5295 end Make_Build_In_Place_Call_In_Assignment;
5297 ----------------------------------------------------
5298 -- Make_Build_In_Place_Call_In_Object_Declaration --
5299 ----------------------------------------------------
5301 procedure Make_Build_In_Place_Call_In_Object_Declaration
5302 (Object_Decl : Node_Id;
5303 Function_Call : Node_Id)
5306 Obj_Def_Id : constant Entity_Id :=
5307 Defining_Identifier (Object_Decl);
5309 Func_Call : Node_Id := Function_Call;
5310 Function_Id : Entity_Id;
5311 Result_Subt : Entity_Id;
5312 Caller_Object : Node_Id;
5313 Call_Deref : Node_Id;
5314 Ref_Type : Entity_Id;
5315 Ptr_Typ_Decl : Node_Id;
5318 Enclosing_Func : Entity_Id;
5319 Pass_Caller_Acc : Boolean := False;
5322 if Nkind (Func_Call) = N_Qualified_Expression then
5323 Func_Call := Expression (Func_Call);
5326 Loc := Sloc (Function_Call);
5328 if Is_Entity_Name (Name (Func_Call)) then
5329 Function_Id := Entity (Name (Func_Call));
5331 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5332 Function_Id := Etype (Name (Func_Call));
5335 raise Program_Error;
5338 Result_Subt := Etype (Function_Id);
5340 -- In the constrained case, add an implicit actual to the function call
5341 -- that provides access to the declared object. An unchecked conversion
5342 -- to the (specific) result type of the function is inserted to handle
5343 -- the case where the object is declared with a class-wide type.
5345 if Is_Constrained (Underlying_Type (Result_Subt)) then
5347 Make_Unchecked_Type_Conversion (Loc,
5348 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5349 Expression => New_Reference_To (Obj_Def_Id, Loc));
5351 -- When the function has a controlling result, an allocation-form
5352 -- parameter must be passed indicating that the caller is allocating
5353 -- the result object. This is needed because such a function can be
5354 -- called as a dispatching operation and must be treated similarly
5355 -- to functions with unconstrained result subtypes.
5357 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5358 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5360 -- If the function's result subtype is unconstrained and the object is
5361 -- a return object of an enclosing build-in-place function, then the
5362 -- implicit build-in-place parameters of the enclosing function must be
5363 -- passed along to the called function.
5365 elsif Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement then
5366 Pass_Caller_Acc := True;
5368 Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
5370 -- If the enclosing function has a constrained result type, then
5371 -- caller allocation will be used.
5373 if Is_Constrained (Etype (Enclosing_Func)) then
5374 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5375 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5377 -- Otherwise, when the enclosing function has an unconstrained result
5378 -- type, the BIP_Alloc_Form formal of the enclosing function must be
5379 -- passed along to the callee.
5382 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5387 (Build_In_Place_Formal (Enclosing_Func, BIP_Alloc_Form),
5391 -- Retrieve the BIPacc formal from the enclosing function and convert
5392 -- it to the access type of the callee's BIP_Object_Access formal.
5395 Make_Unchecked_Type_Conversion (Loc,
5399 (Build_In_Place_Formal (Function_Id, BIP_Object_Access)),
5403 (Build_In_Place_Formal (Enclosing_Func, BIP_Object_Access),
5406 -- In other unconstrained cases, pass an indication to do the allocation
5407 -- on the secondary stack and set Caller_Object to Empty so that a null
5408 -- value will be passed for the caller's object address. A transient
5409 -- scope is established to ensure eventual cleanup of the result.
5412 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5415 Alloc_Form => Secondary_Stack);
5416 Caller_Object := Empty;
5418 Establish_Transient_Scope (Object_Decl, Sec_Stack => True);
5421 Add_Final_List_Actual_To_Build_In_Place_Call
5422 (Func_Call, Function_Id, Acc_Type => Empty);
5424 if Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement
5425 and then Has_Task (Result_Subt)
5427 Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
5429 -- Here we're passing along the master that was passed in to this
5432 Add_Task_Actuals_To_Build_In_Place_Call
5433 (Func_Call, Function_Id,
5436 (Build_In_Place_Formal (Enclosing_Func, BIP_Master), Loc));
5439 Add_Task_Actuals_To_Build_In_Place_Call
5440 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5443 Add_Access_Actual_To_Build_In_Place_Call
5444 (Func_Call, Function_Id, Caller_Object, Is_Access => Pass_Caller_Acc);
5446 -- Create an access type designating the function's result subtype
5449 Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
5452 Make_Full_Type_Declaration (Loc,
5453 Defining_Identifier => Ref_Type,
5455 Make_Access_To_Object_Definition (Loc,
5456 All_Present => True,
5457 Subtype_Indication =>
5458 New_Reference_To (Result_Subt, Loc)));
5460 -- The access type and its accompanying object must be inserted after
5461 -- the object declaration in the constrained case, so that the function
5462 -- call can be passed access to the object. In the unconstrained case,
5463 -- the access type and object must be inserted before the object, since
5464 -- the object declaration is rewritten to be a renaming of a dereference
5465 -- of the access object.
5467 if Is_Constrained (Underlying_Type (Result_Subt)) then
5468 Insert_After_And_Analyze (Object_Decl, Ptr_Typ_Decl);
5470 Insert_Before_And_Analyze (Object_Decl, Ptr_Typ_Decl);
5473 -- Finally, create an access object initialized to a reference to the
5477 Make_Defining_Identifier (Loc,
5478 Chars => New_Internal_Name ('R'));
5479 Set_Etype (Def_Id, Ref_Type);
5482 Make_Reference (Loc,
5483 Prefix => Relocate_Node (Func_Call));
5485 Insert_After_And_Analyze (Ptr_Typ_Decl,
5486 Make_Object_Declaration (Loc,
5487 Defining_Identifier => Def_Id,
5488 Object_Definition => New_Reference_To (Ref_Type, Loc),
5489 Expression => New_Expr));
5491 if Is_Constrained (Underlying_Type (Result_Subt)) then
5492 Set_Expression (Object_Decl, Empty);
5493 Set_No_Initialization (Object_Decl);
5495 -- In case of an unconstrained result subtype, rewrite the object
5496 -- declaration as an object renaming where the renamed object is a
5497 -- dereference of <function_Call>'reference:
5499 -- Obj : Subt renames <function_call>'Ref.all;
5503 Make_Explicit_Dereference (Loc,
5504 Prefix => New_Reference_To (Def_Id, Loc));
5506 Rewrite (Object_Decl,
5507 Make_Object_Renaming_Declaration (Loc,
5508 Defining_Identifier => Make_Defining_Identifier (Loc,
5509 New_Internal_Name ('D')),
5510 Access_Definition => Empty,
5511 Subtype_Mark => New_Occurrence_Of (Result_Subt, Loc),
5512 Name => Call_Deref));
5514 Set_Renamed_Object (Defining_Identifier (Object_Decl), Call_Deref);
5516 Analyze (Object_Decl);
5518 -- Replace the internal identifier of the renaming declaration's
5519 -- entity with identifier of the original object entity. We also have
5520 -- to exchange the entities containing their defining identifiers to
5521 -- ensure the correct replacement of the object declaration by the
5522 -- object renaming declaration to avoid homograph conflicts (since
5523 -- the object declaration's defining identifier was already entered
5524 -- in current scope).
5526 Set_Chars (Defining_Identifier (Object_Decl), Chars (Obj_Def_Id));
5527 Exchange_Entities (Defining_Identifier (Object_Decl), Obj_Def_Id);
5530 -- If the object entity has a class-wide Etype, then we need to change
5531 -- it to the result subtype of the function call, because otherwise the
5532 -- object will be class-wide without an explicit intialization and won't
5533 -- be allocated properly by the back end. It seems unclean to make such
5534 -- a revision to the type at this point, and we should try to improve
5535 -- this treatment when build-in-place functions with class-wide results
5536 -- are implemented. ???
5538 if Is_Class_Wide_Type (Etype (Defining_Identifier (Object_Decl))) then
5539 Set_Etype (Defining_Identifier (Object_Decl), Result_Subt);
5541 end Make_Build_In_Place_Call_In_Object_Declaration;