1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Errout; use Errout;
31 with Elists; use Elists;
32 with Exp_Atag; use Exp_Atag;
33 with Exp_Ch2; use Exp_Ch2;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Dbug; use Exp_Dbug;
38 with Exp_Disp; use Exp_Disp;
39 with Exp_Dist; use Exp_Dist;
40 with Exp_Intr; use Exp_Intr;
41 with Exp_Pakd; use Exp_Pakd;
42 with Exp_Tss; use Exp_Tss;
43 with Exp_Util; use Exp_Util;
44 with Fname; use Fname;
45 with Freeze; use Freeze;
46 with Inline; use Inline;
48 with Namet; use Namet;
49 with Nlists; use Nlists;
50 with Nmake; use Nmake;
52 with Restrict; use Restrict;
53 with Rident; use Rident;
54 with Rtsfind; use Rtsfind;
56 with Sem_Ch6; use Sem_Ch6;
57 with Sem_Ch8; use Sem_Ch8;
58 with Sem_Ch12; use Sem_Ch12;
59 with Sem_Ch13; use Sem_Ch13;
60 with Sem_Eval; use Sem_Eval;
61 with Sem_Disp; use Sem_Disp;
62 with Sem_Dist; use Sem_Dist;
63 with Sem_Mech; use Sem_Mech;
64 with Sem_Res; use Sem_Res;
65 with Sem_Util; use Sem_Util;
66 with Sinfo; use Sinfo;
67 with Snames; use Snames;
68 with Stand; use Stand;
69 with Targparm; use Targparm;
70 with Tbuild; use Tbuild;
71 with Uintp; use Uintp;
72 with Validsw; use Validsw;
74 package body Exp_Ch6 is
76 -----------------------
77 -- Local Subprograms --
78 -----------------------
80 procedure Add_Access_Actual_To_Build_In_Place_Call
81 (Function_Call : Node_Id;
82 Function_Id : Entity_Id;
83 Return_Object : Node_Id;
84 Is_Access : Boolean := False);
85 -- Ada 2005 (AI-318-02): Apply the Unrestricted_Access attribute to the
86 -- object name given by Return_Object and add the attribute to the end of
87 -- the actual parameter list associated with the build-in-place function
88 -- call denoted by Function_Call. However, if Is_Access is True, then
89 -- Return_Object is already an access expression, in which case it's passed
90 -- along directly to the build-in-place function. Finally, if Return_Object
91 -- is empty, then pass a null literal as the actual.
93 procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
94 (Function_Call : Node_Id;
95 Function_Id : Entity_Id;
96 Alloc_Form : BIP_Allocation_Form := Unspecified;
97 Alloc_Form_Exp : Node_Id := Empty);
98 -- Ada 2005 (AI-318-02): Add an actual indicating the form of allocation,
99 -- if any, to be done by a build-in-place function. If Alloc_Form_Exp is
100 -- present, then use it, otherwise pass a literal corresponding to the
101 -- Alloc_Form parameter (which must not be Unspecified in that case).
103 procedure Add_Extra_Actual_To_Call
104 (Subprogram_Call : Node_Id;
105 Extra_Formal : Entity_Id;
106 Extra_Actual : Node_Id);
107 -- Adds Extra_Actual as a named parameter association for the formal
108 -- Extra_Formal in Subprogram_Call.
110 procedure Add_Final_List_Actual_To_Build_In_Place_Call
111 (Function_Call : Node_Id;
112 Function_Id : Entity_Id;
113 Acc_Type : Entity_Id);
114 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type has
115 -- controlled parts, add an actual parameter that is a pointer to
116 -- appropriate finalization list. The finalization list is that of the
117 -- current scope, except for "new Acc'(F(...))" in which case it's the
118 -- finalization list of the access type returned by the allocator. Acc_Type
119 -- is that type in the allocator case; Empty otherwise.
121 procedure Add_Task_Actuals_To_Build_In_Place_Call
122 (Function_Call : Node_Id;
123 Function_Id : Entity_Id;
124 Master_Actual : Node_Id);
125 -- Ada 2005 (AI-318-02): For a build-in-place call, if the result type
126 -- contains tasks, add two actual parameters: the master, and a pointer to
127 -- the caller's activation chain. Master_Actual is the actual parameter
128 -- expression to pass for the master. In most cases, this is the current
129 -- master (_master). The two exceptions are: If the function call is the
130 -- initialization expression for an allocator, we pass the master of the
131 -- access type. If the function call is the initialization expression for
132 -- a return object, we pass along the master passed in by the caller. The
133 -- activation chain to pass is always the local one.
135 procedure Check_Overriding_Operation (Subp : Entity_Id);
136 -- Subp is a dispatching operation. Check whether it may override an
137 -- inherited private operation, in which case its DT entry is that of
138 -- the hidden operation, not the one it may have received earlier.
139 -- This must be done before emitting the code to set the corresponding
140 -- DT to the address of the subprogram. The actual placement of Subp in
141 -- the proper place in the list of primitive operations is done in
142 -- Declare_Inherited_Private_Subprograms, which also has to deal with
143 -- implicit operations. This duplication is unavoidable for now???
145 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
146 -- This procedure is called only if the subprogram body N, whose spec
147 -- has the given entity Spec, contains a parameterless recursive call.
148 -- It attempts to generate runtime code to detect if this a case of
149 -- infinite recursion.
151 -- The body is scanned to determine dependencies. If the only external
152 -- dependencies are on a small set of scalar variables, then the values
153 -- of these variables are captured on entry to the subprogram, and if
154 -- the values are not changed for the call, we know immediately that
155 -- we have an infinite recursion.
157 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id);
158 -- For each actual of an in-out or out parameter which is a numeric
159 -- (view) conversion of the form T (A), where A denotes a variable,
160 -- we insert the declaration:
162 -- Temp : T[ := T (A)];
164 -- prior to the call. Then we replace the actual with a reference to Temp,
165 -- and append the assignment:
167 -- A := TypeA (Temp);
169 -- after the call. Here TypeA is the actual type of variable A.
170 -- For out parameters, the initial declaration has no expression.
171 -- If A is not an entity name, we generate instead:
173 -- Var : TypeA renames A;
174 -- Temp : T := Var; -- omitting expression for out parameter.
176 -- Var := TypeA (Temp);
178 -- For other in-out parameters, we emit the required constraint checks
179 -- before and/or after the call.
181 -- For all parameter modes, actuals that denote components and slices
182 -- of packed arrays are expanded into suitable temporaries.
184 -- For non-scalar objects that are possibly unaligned, add call by copy
185 -- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
187 procedure Expand_Inlined_Call
190 Orig_Subp : Entity_Id);
191 -- If called subprogram can be inlined by the front-end, retrieve the
192 -- analyzed body, replace formals with actuals and expand call in place.
193 -- Generate thunks for actuals that are expressions, and insert the
194 -- corresponding constant declarations before the call. If the original
195 -- call is to a derived operation, the return type is the one of the
196 -- derived operation, but the body is that of the original, so return
197 -- expressions in the body must be converted to the desired type (which
198 -- is simply not noted in the tree without inline expansion).
200 function Expand_Protected_Object_Reference
202 Scop : Entity_Id) return Node_Id;
204 procedure Expand_Protected_Subprogram_Call
208 -- A call to a protected subprogram within the protected object may appear
209 -- as a regular call. The list of actuals must be expanded to contain a
210 -- reference to the object itself, and the call becomes a call to the
211 -- corresponding protected subprogram.
213 ----------------------------------------------
214 -- Add_Access_Actual_To_Build_In_Place_Call --
215 ----------------------------------------------
217 procedure Add_Access_Actual_To_Build_In_Place_Call
218 (Function_Call : Node_Id;
219 Function_Id : Entity_Id;
220 Return_Object : Node_Id;
221 Is_Access : Boolean := False)
223 Loc : constant Source_Ptr := Sloc (Function_Call);
224 Obj_Address : Node_Id;
225 Obj_Acc_Formal : Entity_Id;
228 -- Locate the implicit access parameter in the called function
230 Obj_Acc_Formal := Build_In_Place_Formal (Function_Id, BIP_Object_Access);
232 -- If no return object is provided, then pass null
234 if not Present (Return_Object) then
235 Obj_Address := Make_Null (Loc);
236 Set_Parent (Obj_Address, Function_Call);
238 -- If Return_Object is already an expression of an access type, then use
239 -- it directly, since it must be an access value denoting the return
240 -- object, and couldn't possibly be the return object itself.
243 Obj_Address := Return_Object;
244 Set_Parent (Obj_Address, Function_Call);
246 -- Apply Unrestricted_Access to caller's return object
250 Make_Attribute_Reference (Loc,
251 Prefix => Return_Object,
252 Attribute_Name => Name_Unrestricted_Access);
254 Set_Parent (Return_Object, Obj_Address);
255 Set_Parent (Obj_Address, Function_Call);
258 Analyze_And_Resolve (Obj_Address, Etype (Obj_Acc_Formal));
260 -- Build the parameter association for the new actual and add it to the
261 -- end of the function's actuals.
263 Add_Extra_Actual_To_Call (Function_Call, Obj_Acc_Formal, Obj_Address);
264 end Add_Access_Actual_To_Build_In_Place_Call;
266 --------------------------------------------------
267 -- Add_Alloc_Form_Actual_To_Build_In_Place_Call --
268 --------------------------------------------------
270 procedure Add_Alloc_Form_Actual_To_Build_In_Place_Call
271 (Function_Call : Node_Id;
272 Function_Id : Entity_Id;
273 Alloc_Form : BIP_Allocation_Form := Unspecified;
274 Alloc_Form_Exp : Node_Id := Empty)
276 Loc : constant Source_Ptr := Sloc (Function_Call);
277 Alloc_Form_Actual : Node_Id;
278 Alloc_Form_Formal : Node_Id;
281 -- The allocation form generally doesn't need to be passed in the case
282 -- of a constrained result subtype, since normally the caller performs
283 -- the allocation in that case. However this formal is still needed in
284 -- the case where the function has a tagged result, because generally
285 -- such functions can be called in a dispatching context and such calls
286 -- must be handled like calls to class-wide functions.
288 if Is_Constrained (Underlying_Type (Etype (Function_Id)))
289 and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
294 -- Locate the implicit allocation form parameter in the called function.
295 -- Maybe it would be better for each implicit formal of a build-in-place
296 -- function to have a flag or a Uint attribute to identify it. ???
298 Alloc_Form_Formal := Build_In_Place_Formal (Function_Id, BIP_Alloc_Form);
300 if Present (Alloc_Form_Exp) then
301 pragma Assert (Alloc_Form = Unspecified);
303 Alloc_Form_Actual := Alloc_Form_Exp;
306 pragma Assert (Alloc_Form /= Unspecified);
309 Make_Integer_Literal (Loc,
310 Intval => UI_From_Int (BIP_Allocation_Form'Pos (Alloc_Form)));
313 Analyze_And_Resolve (Alloc_Form_Actual, Etype (Alloc_Form_Formal));
315 -- Build the parameter association for the new actual and add it to the
316 -- end of the function's actuals.
318 Add_Extra_Actual_To_Call
319 (Function_Call, Alloc_Form_Formal, Alloc_Form_Actual);
320 end Add_Alloc_Form_Actual_To_Build_In_Place_Call;
322 ------------------------------
323 -- Add_Extra_Actual_To_Call --
324 ------------------------------
326 procedure Add_Extra_Actual_To_Call
327 (Subprogram_Call : Node_Id;
328 Extra_Formal : Entity_Id;
329 Extra_Actual : Node_Id)
331 Loc : constant Source_Ptr := Sloc (Subprogram_Call);
332 Param_Assoc : Node_Id;
336 Make_Parameter_Association (Loc,
337 Selector_Name => New_Occurrence_Of (Extra_Formal, Loc),
338 Explicit_Actual_Parameter => Extra_Actual);
340 Set_Parent (Param_Assoc, Subprogram_Call);
341 Set_Parent (Extra_Actual, Param_Assoc);
343 if Present (Parameter_Associations (Subprogram_Call)) then
344 if Nkind (Last (Parameter_Associations (Subprogram_Call))) =
345 N_Parameter_Association
348 -- Find last named actual, and append
353 L := First_Actual (Subprogram_Call);
354 while Present (L) loop
355 if No (Next_Actual (L)) then
356 Set_Next_Named_Actual (Parent (L), Extra_Actual);
364 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
367 Append (Param_Assoc, To => Parameter_Associations (Subprogram_Call));
370 Set_Parameter_Associations (Subprogram_Call, New_List (Param_Assoc));
371 Set_First_Named_Actual (Subprogram_Call, Extra_Actual);
373 end Add_Extra_Actual_To_Call;
375 --------------------------------------------------
376 -- Add_Final_List_Actual_To_Build_In_Place_Call --
377 --------------------------------------------------
379 procedure Add_Final_List_Actual_To_Build_In_Place_Call
380 (Function_Call : Node_Id;
381 Function_Id : Entity_Id;
382 Acc_Type : Entity_Id)
384 Loc : constant Source_Ptr := Sloc (Function_Call);
385 Final_List : Node_Id;
386 Final_List_Actual : Node_Id;
387 Final_List_Formal : Node_Id;
390 -- No such extra parameter is needed if there are no controlled parts.
391 -- The test for Controlled_Type accounts for class-wide results (which
392 -- potentially have controlled parts, even if the root type doesn't),
393 -- and the test for a tagged result type is needed because calls to
394 -- such a function can in general occur in dispatching contexts, which
395 -- must be treated the same as a call to class-wide functions. Both of
396 -- these situations require that a finalization list be passed.
398 if not Controlled_Type (Underlying_Type (Etype (Function_Id)))
399 and then not Is_Tagged_Type (Underlying_Type (Etype (Function_Id)))
404 -- Locate implicit finalization list parameter in the called function
406 Final_List_Formal := Build_In_Place_Formal (Function_Id, BIP_Final_List);
408 -- Create the actual which is a pointer to the appropriate finalization
409 -- list. Acc_Type is present if and only if this call is the
410 -- initialization of an allocator. Use the Current_Scope or the Acc_Type
413 if Present (Acc_Type)
414 and then (Ekind (Acc_Type) = E_Anonymous_Access_Type
416 Present (Associated_Final_Chain (Base_Type (Acc_Type))))
418 Final_List := Find_Final_List (Acc_Type);
420 Final_List := Find_Final_List (Current_Scope);
424 Make_Attribute_Reference (Loc,
425 Prefix => Final_List,
426 Attribute_Name => Name_Unrestricted_Access);
428 Analyze_And_Resolve (Final_List_Actual, Etype (Final_List_Formal));
430 -- Build the parameter association for the new actual and add it to the
431 -- end of the function's actuals.
433 Add_Extra_Actual_To_Call
434 (Function_Call, Final_List_Formal, Final_List_Actual);
435 end Add_Final_List_Actual_To_Build_In_Place_Call;
437 ---------------------------------------------
438 -- Add_Task_Actuals_To_Build_In_Place_Call --
439 ---------------------------------------------
441 procedure Add_Task_Actuals_To_Build_In_Place_Call
442 (Function_Call : Node_Id;
443 Function_Id : Entity_Id;
444 Master_Actual : Node_Id)
445 -- Note: Master_Actual can be Empty, but only if there are no tasks
447 Loc : constant Source_Ptr := Sloc (Function_Call);
450 -- No such extra parameters are needed if there are no tasks
452 if not Has_Task (Etype (Function_Id)) then
459 Master_Formal : Node_Id;
461 -- Locate implicit master parameter in the called function
463 Master_Formal := Build_In_Place_Formal (Function_Id, BIP_Master);
465 Analyze_And_Resolve (Master_Actual, Etype (Master_Formal));
467 -- Build the parameter association for the new actual and add it to
468 -- the end of the function's actuals.
470 Add_Extra_Actual_To_Call
471 (Function_Call, Master_Formal, Master_Actual);
474 -- The activation chain
477 Activation_Chain_Actual : Node_Id;
478 Activation_Chain_Formal : Node_Id;
480 -- Locate implicit activation chain parameter in the called function
482 Activation_Chain_Formal := Build_In_Place_Formal
483 (Function_Id, BIP_Activation_Chain);
485 -- Create the actual which is a pointer to the current activation
488 Activation_Chain_Actual :=
489 Make_Attribute_Reference (Loc,
490 Prefix => Make_Identifier (Loc, Name_uChain),
491 Attribute_Name => Name_Unrestricted_Access);
494 (Activation_Chain_Actual, Etype (Activation_Chain_Formal));
496 -- Build the parameter association for the new actual and add it to
497 -- the end of the function's actuals.
499 Add_Extra_Actual_To_Call
500 (Function_Call, Activation_Chain_Formal, Activation_Chain_Actual);
502 end Add_Task_Actuals_To_Build_In_Place_Call;
504 -----------------------
505 -- BIP_Formal_Suffix --
506 -----------------------
508 function BIP_Formal_Suffix (Kind : BIP_Formal_Kind) return String is
511 when BIP_Alloc_Form =>
513 when BIP_Final_List =>
514 return "BIPfinallist";
517 when BIP_Activation_Chain =>
518 return "BIPactivationchain";
519 when BIP_Object_Access =>
522 end BIP_Formal_Suffix;
524 ---------------------------
525 -- Build_In_Place_Formal --
526 ---------------------------
528 function Build_In_Place_Formal
530 Kind : BIP_Formal_Kind) return Entity_Id
532 Extra_Formal : Entity_Id := Extra_Formals (Func);
535 -- Maybe it would be better for each implicit formal of a build-in-place
536 -- function to have a flag or a Uint attribute to identify it. ???
539 pragma Assert (Present (Extra_Formal));
541 Chars (Extra_Formal) =
542 New_External_Name (Chars (Func), BIP_Formal_Suffix (Kind));
543 Next_Formal_With_Extras (Extra_Formal);
547 end Build_In_Place_Formal;
549 --------------------------------
550 -- Check_Overriding_Operation --
551 --------------------------------
553 procedure Check_Overriding_Operation (Subp : Entity_Id) is
554 Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
555 Op_List : constant Elist_Id := Primitive_Operations (Typ);
561 if Is_Derived_Type (Typ)
562 and then not Is_Private_Type (Typ)
563 and then In_Open_Scopes (Scope (Etype (Typ)))
564 and then Typ = Base_Type (Typ)
566 -- Subp overrides an inherited private operation if there is an
567 -- inherited operation with a different name than Subp (see
568 -- Derive_Subprogram) whose Alias is a hidden subprogram with the
569 -- same name as Subp.
571 Op_Elmt := First_Elmt (Op_List);
572 while Present (Op_Elmt) loop
573 Prim_Op := Node (Op_Elmt);
574 Par_Op := Alias (Prim_Op);
577 and then not Comes_From_Source (Prim_Op)
578 and then Chars (Prim_Op) /= Chars (Par_Op)
579 and then Chars (Par_Op) = Chars (Subp)
580 and then Is_Hidden (Par_Op)
581 and then Type_Conformant (Prim_Op, Subp)
583 Set_DT_Position (Subp, DT_Position (Prim_Op));
589 end Check_Overriding_Operation;
591 -------------------------------
592 -- Detect_Infinite_Recursion --
593 -------------------------------
595 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
596 Loc : constant Source_Ptr := Sloc (N);
598 Var_List : constant Elist_Id := New_Elmt_List;
599 -- List of globals referenced by body of procedure
601 Call_List : constant Elist_Id := New_Elmt_List;
602 -- List of recursive calls in body of procedure
604 Shad_List : constant Elist_Id := New_Elmt_List;
605 -- List of entity id's for entities created to capture the value of
606 -- referenced globals on entry to the procedure.
608 Scop : constant Uint := Scope_Depth (Spec);
609 -- This is used to record the scope depth of the current procedure, so
610 -- that we can identify global references.
612 Max_Vars : constant := 4;
613 -- Do not test more than four global variables
615 Count_Vars : Natural := 0;
616 -- Count variables found so far
628 function Process (Nod : Node_Id) return Traverse_Result;
629 -- Function to traverse the subprogram body (using Traverse_Func)
635 function Process (Nod : Node_Id) return Traverse_Result is
639 if Nkind (Nod) = N_Procedure_Call_Statement then
641 -- Case of one of the detected recursive calls
643 if Is_Entity_Name (Name (Nod))
644 and then Has_Recursive_Call (Entity (Name (Nod)))
645 and then Entity (Name (Nod)) = Spec
647 Append_Elmt (Nod, Call_List);
650 -- Any other procedure call may have side effects
656 -- A call to a pure function can always be ignored
658 elsif Nkind (Nod) = N_Function_Call
659 and then Is_Entity_Name (Name (Nod))
660 and then Is_Pure (Entity (Name (Nod)))
664 -- Case of an identifier reference
666 elsif Nkind (Nod) = N_Identifier then
669 -- If no entity, then ignore the reference
671 -- Not clear why this can happen. To investigate, remove this
672 -- test and look at the crash that occurs here in 3401-004 ???
677 -- Ignore entities with no Scope, again not clear how this
678 -- can happen, to investigate, look at 4108-008 ???
680 elsif No (Scope (Ent)) then
683 -- Ignore the reference if not to a more global object
685 elsif Scope_Depth (Scope (Ent)) >= Scop then
688 -- References to types, exceptions and constants are always OK
691 or else Ekind (Ent) = E_Exception
692 or else Ekind (Ent) = E_Constant
696 -- If other than a non-volatile scalar variable, we have some
697 -- kind of global reference (e.g. to a function) that we cannot
698 -- deal with so we forget the attempt.
700 elsif Ekind (Ent) /= E_Variable
701 or else not Is_Scalar_Type (Etype (Ent))
702 or else Treat_As_Volatile (Ent)
706 -- Otherwise we have a reference to a global scalar
709 -- Loop through global entities already detected
711 Elm := First_Elmt (Var_List);
713 -- If not detected before, record this new global reference
716 Count_Vars := Count_Vars + 1;
718 if Count_Vars <= Max_Vars then
719 Append_Elmt (Entity (Nod), Var_List);
726 -- If recorded before, ignore
728 elsif Node (Elm) = Entity (Nod) then
731 -- Otherwise keep looking
741 -- For all other node kinds, recursively visit syntactic children
748 function Traverse_Body is new Traverse_Func (Process);
750 -- Start of processing for Detect_Infinite_Recursion
753 -- Do not attempt detection in No_Implicit_Conditional mode, since we
754 -- won't be able to generate the code to handle the recursion in any
757 if Restriction_Active (No_Implicit_Conditionals) then
761 -- Otherwise do traversal and quit if we get abandon signal
763 if Traverse_Body (N) = Abandon then
766 -- We must have a call, since Has_Recursive_Call was set. If not just
767 -- ignore (this is only an error check, so if we have a funny situation,
768 -- due to bugs or errors, we do not want to bomb!)
770 elsif Is_Empty_Elmt_List (Call_List) then
774 -- Here is the case where we detect recursion at compile time
776 -- Push our current scope for analyzing the declarations and code that
777 -- we will insert for the checking.
781 -- This loop builds temporary variables for each of the referenced
782 -- globals, so that at the end of the loop the list Shad_List contains
783 -- these temporaries in one-to-one correspondence with the elements in
787 Elm := First_Elmt (Var_List);
788 while Present (Elm) loop
791 Make_Defining_Identifier (Loc,
792 Chars => New_Internal_Name ('S'));
793 Append_Elmt (Ent, Shad_List);
795 -- Insert a declaration for this temporary at the start of the
796 -- declarations for the procedure. The temporaries are declared as
797 -- constant objects initialized to the current values of the
798 -- corresponding temporaries.
801 Make_Object_Declaration (Loc,
802 Defining_Identifier => Ent,
803 Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
804 Constant_Present => True,
805 Expression => New_Occurrence_Of (Var, Loc));
808 Prepend (Decl, Declarations (N));
810 Insert_After (Last, Decl);
818 -- Loop through calls
820 Call := First_Elmt (Call_List);
821 while Present (Call) loop
823 -- Build a predicate expression of the form
826 -- and then global1 = temp1
827 -- and then global2 = temp2
830 -- This predicate determines if any of the global values
831 -- referenced by the procedure have changed since the
832 -- current call, if not an infinite recursion is assured.
834 Test := New_Occurrence_Of (Standard_True, Loc);
836 Elm1 := First_Elmt (Var_List);
837 Elm2 := First_Elmt (Shad_List);
838 while Present (Elm1) loop
844 Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
845 Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
851 -- Now we replace the call with the sequence
853 -- if no-changes (see above) then
854 -- raise Storage_Error;
859 Rewrite (Node (Call),
860 Make_If_Statement (Loc,
862 Then_Statements => New_List (
863 Make_Raise_Storage_Error (Loc,
864 Reason => SE_Infinite_Recursion)),
866 Else_Statements => New_List (
867 Relocate_Node (Node (Call)))));
869 Analyze (Node (Call));
874 -- Remove temporary scope stack entry used for analysis
877 end Detect_Infinite_Recursion;
883 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id) is
884 Loc : constant Source_Ptr := Sloc (N);
889 E_Formal : Entity_Id;
891 procedure Add_Call_By_Copy_Code;
892 -- For cases where the parameter must be passed by copy, this routine
893 -- generates a temporary variable into which the actual is copied and
894 -- then passes this as the parameter. For an OUT or IN OUT parameter,
895 -- an assignment is also generated to copy the result back. The call
896 -- also takes care of any constraint checks required for the type
897 -- conversion case (on both the way in and the way out).
899 procedure Add_Simple_Call_By_Copy_Code;
900 -- This is similar to the above, but is used in cases where we know
901 -- that all that is needed is to simply create a temporary and copy
902 -- the value in and out of the temporary.
904 procedure Check_Fortran_Logical;
905 -- A value of type Logical that is passed through a formal parameter
906 -- must be normalized because .TRUE. usually does not have the same
907 -- representation as True. We assume that .FALSE. = False = 0.
908 -- What about functions that return a logical type ???
910 function Is_Legal_Copy return Boolean;
911 -- Check that an actual can be copied before generating the temporary
912 -- to be used in the call. If the actual is of a by_reference type then
913 -- the program is illegal (this can only happen in the presence of
914 -- rep. clauses that force an incorrect alignment). If the formal is
915 -- a by_reference parameter imposed by a DEC pragma, emit a warning to
916 -- the effect that this might lead to unaligned arguments.
918 function Make_Var (Actual : Node_Id) return Entity_Id;
919 -- Returns an entity that refers to the given actual parameter,
920 -- Actual (not including any type conversion). If Actual is an
921 -- entity name, then this entity is returned unchanged, otherwise
922 -- a renaming is created to provide an entity for the actual.
924 procedure Reset_Packed_Prefix;
925 -- The expansion of a packed array component reference is delayed in
926 -- the context of a call. Now we need to complete the expansion, so we
927 -- unmark the analyzed bits in all prefixes.
929 ---------------------------
930 -- Add_Call_By_Copy_Code --
931 ---------------------------
933 procedure Add_Call_By_Copy_Code is
939 F_Typ : constant Entity_Id := Etype (Formal);
944 if not Is_Legal_Copy then
949 Make_Defining_Identifier (Loc,
950 Chars => New_Internal_Name ('T'));
952 -- Use formal type for temp, unless formal type is an unconstrained
953 -- array, in which case we don't have to worry about bounds checks,
954 -- and we use the actual type, since that has appropriate bounds.
956 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
957 Indic := New_Occurrence_Of (Etype (Actual), Loc);
959 Indic := New_Occurrence_Of (Etype (Formal), Loc);
962 if Nkind (Actual) = N_Type_Conversion then
963 V_Typ := Etype (Expression (Actual));
965 -- If the formal is an (in-)out parameter, capture the name
966 -- of the variable in order to build the post-call assignment.
968 Var := Make_Var (Expression (Actual));
970 Crep := not Same_Representation
971 (F_Typ, Etype (Expression (Actual)));
974 V_Typ := Etype (Actual);
975 Var := Make_Var (Actual);
979 -- Setup initialization for case of in out parameter, or an out
980 -- parameter where the formal is an unconstrained array (in the
981 -- latter case, we have to pass in an object with bounds).
983 -- If this is an out parameter, the initial copy is wasteful, so as
984 -- an optimization for the one-dimensional case we extract the
985 -- bounds of the actual and build an uninitialized temporary of the
988 if Ekind (Formal) = E_In_Out_Parameter
989 or else (Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ))
991 if Nkind (Actual) = N_Type_Conversion then
992 if Conversion_OK (Actual) then
993 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
995 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
998 elsif Ekind (Formal) = E_Out_Parameter
999 and then Is_Array_Type (F_Typ)
1000 and then Number_Dimensions (F_Typ) = 1
1001 and then not Has_Non_Null_Base_Init_Proc (F_Typ)
1003 -- Actual is a one-dimensional array or slice, and the type
1004 -- requires no initialization. Create a temporary of the
1005 -- right size, but do not copy actual into it (optimization).
1009 Make_Subtype_Indication (Loc,
1011 New_Occurrence_Of (F_Typ, Loc),
1013 Make_Index_Or_Discriminant_Constraint (Loc,
1014 Constraints => New_List (
1017 Make_Attribute_Reference (Loc,
1018 Prefix => New_Occurrence_Of (Var, Loc),
1019 Attribute_name => Name_First),
1021 Make_Attribute_Reference (Loc,
1022 Prefix => New_Occurrence_Of (Var, Loc),
1023 Attribute_Name => Name_Last)))));
1026 Init := New_Occurrence_Of (Var, Loc);
1029 -- An initialization is created for packed conversions as
1030 -- actuals for out parameters to enable Make_Object_Declaration
1031 -- to determine the proper subtype for N_Node. Note that this
1032 -- is wasteful because the extra copying on the call side is
1033 -- not required for such out parameters. ???
1035 elsif Ekind (Formal) = E_Out_Parameter
1036 and then Nkind (Actual) = N_Type_Conversion
1037 and then (Is_Bit_Packed_Array (F_Typ)
1039 Is_Bit_Packed_Array (Etype (Expression (Actual))))
1041 if Conversion_OK (Actual) then
1042 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1044 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1047 elsif Ekind (Formal) = E_In_Parameter then
1049 -- Handle the case in which the actual is a type conversion
1051 if Nkind (Actual) = N_Type_Conversion then
1052 if Conversion_OK (Actual) then
1053 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1055 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
1058 Init := New_Occurrence_Of (Var, Loc);
1066 Make_Object_Declaration (Loc,
1067 Defining_Identifier => Temp,
1068 Object_Definition => Indic,
1069 Expression => Init);
1070 Set_Assignment_OK (N_Node);
1071 Insert_Action (N, N_Node);
1073 -- Now, normally the deal here is that we use the defining
1074 -- identifier created by that object declaration. There is
1075 -- one exception to this. In the change of representation case
1076 -- the above declaration will end up looking like:
1078 -- temp : type := identifier;
1080 -- And in this case we might as well use the identifier directly
1081 -- and eliminate the temporary. Note that the analysis of the
1082 -- declaration was not a waste of time in that case, since it is
1083 -- what generated the necessary change of representation code. If
1084 -- the change of representation introduced additional code, as in
1085 -- a fixed-integer conversion, the expression is not an identifier
1086 -- and must be kept.
1089 and then Present (Expression (N_Node))
1090 and then Is_Entity_Name (Expression (N_Node))
1092 Temp := Entity (Expression (N_Node));
1093 Rewrite (N_Node, Make_Null_Statement (Loc));
1096 -- For IN parameter, all we do is to replace the actual
1098 if Ekind (Formal) = E_In_Parameter then
1099 Rewrite (Actual, New_Reference_To (Temp, Loc));
1102 -- Processing for OUT or IN OUT parameter
1105 -- Kill current value indications for the temporary variable we
1106 -- created, since we just passed it as an OUT parameter.
1108 Kill_Current_Values (Temp);
1110 -- If type conversion, use reverse conversion on exit
1112 if Nkind (Actual) = N_Type_Conversion then
1113 if Conversion_OK (Actual) then
1114 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1116 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
1119 Expr := New_Occurrence_Of (Temp, Loc);
1122 Rewrite (Actual, New_Reference_To (Temp, Loc));
1125 -- If the actual is a conversion of a packed reference, it may
1126 -- already have been expanded by Remove_Side_Effects, and the
1127 -- resulting variable is a temporary which does not designate
1128 -- the proper out-parameter, which may not be addressable. In
1129 -- that case, generate an assignment to the original expression
1130 -- (before expansion of the packed reference) so that the proper
1131 -- expansion of assignment to a packed component can take place.
1138 if Is_Renaming_Of_Object (Var)
1139 and then Nkind (Renamed_Object (Var)) = N_Selected_Component
1140 and then Is_Entity_Name (Prefix (Renamed_Object (Var)))
1141 and then Nkind (Original_Node (Prefix (Renamed_Object (Var))))
1142 = N_Indexed_Component
1144 Has_Non_Standard_Rep (Etype (Prefix (Renamed_Object (Var))))
1146 Obj := Renamed_Object (Var);
1148 Make_Selected_Component (Loc,
1150 New_Copy_Tree (Original_Node (Prefix (Obj))),
1151 Selector_Name => New_Copy (Selector_Name (Obj)));
1152 Reset_Analyzed_Flags (Lhs);
1155 Lhs := New_Occurrence_Of (Var, Loc);
1158 Set_Assignment_OK (Lhs);
1160 Append_To (Post_Call,
1161 Make_Assignment_Statement (Loc,
1163 Expression => Expr));
1167 end Add_Call_By_Copy_Code;
1169 ----------------------------------
1170 -- Add_Simple_Call_By_Copy_Code --
1171 ----------------------------------
1173 procedure Add_Simple_Call_By_Copy_Code is
1181 F_Typ : constant Entity_Id := Etype (Formal);
1184 if not Is_Legal_Copy then
1188 -- Use formal type for temp, unless formal type is an unconstrained
1189 -- array, in which case we don't have to worry about bounds checks,
1190 -- and we use the actual type, since that has appropriate bounds.
1192 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
1193 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1195 Indic := New_Occurrence_Of (Etype (Formal), Loc);
1198 -- Prepare to generate code
1200 Reset_Packed_Prefix;
1203 Make_Defining_Identifier (Loc,
1204 Chars => New_Internal_Name ('T'));
1205 Incod := Relocate_Node (Actual);
1206 Outcod := New_Copy_Tree (Incod);
1208 -- Generate declaration of temporary variable, initializing it
1209 -- with the input parameter unless we have an OUT formal or
1210 -- this is an initialization call.
1212 -- If the formal is an out parameter with discriminants, the
1213 -- discriminants must be captured even if the rest of the object
1214 -- is in principle uninitialized, because the discriminants may
1215 -- be read by the called subprogram.
1217 if Ekind (Formal) = E_Out_Parameter then
1220 if Has_Discriminants (Etype (Formal)) then
1221 Indic := New_Occurrence_Of (Etype (Actual), Loc);
1224 elsif Inside_Init_Proc then
1226 -- Could use a comment here to match comment below ???
1228 if Nkind (Actual) /= N_Selected_Component
1230 not Has_Discriminant_Dependent_Constraint
1231 (Entity (Selector_Name (Actual)))
1235 -- Otherwise, keep the component in order to generate the proper
1236 -- actual subtype, that depends on enclosing discriminants.
1244 Make_Object_Declaration (Loc,
1245 Defining_Identifier => Temp,
1246 Object_Definition => Indic,
1247 Expression => Incod);
1252 -- If the call is to initialize a component of a composite type,
1253 -- and the component does not depend on discriminants, use the
1254 -- actual type of the component. This is required in case the
1255 -- component is constrained, because in general the formal of the
1256 -- initialization procedure will be unconstrained. Note that if
1257 -- the component being initialized is constrained by an enclosing
1258 -- discriminant, the presence of the initialization in the
1259 -- declaration will generate an expression for the actual subtype.
1261 Set_No_Initialization (Decl);
1262 Set_Object_Definition (Decl,
1263 New_Occurrence_Of (Etype (Actual), Loc));
1266 Insert_Action (N, Decl);
1268 -- The actual is simply a reference to the temporary
1270 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
1272 -- Generate copy out if OUT or IN OUT parameter
1274 if Ekind (Formal) /= E_In_Parameter then
1276 Rhs := New_Occurrence_Of (Temp, Loc);
1278 -- Deal with conversion
1280 if Nkind (Lhs) = N_Type_Conversion then
1281 Lhs := Expression (Lhs);
1282 Rhs := Convert_To (Etype (Actual), Rhs);
1285 Append_To (Post_Call,
1286 Make_Assignment_Statement (Loc,
1288 Expression => Rhs));
1289 Set_Assignment_OK (Name (Last (Post_Call)));
1291 end Add_Simple_Call_By_Copy_Code;
1293 ---------------------------
1294 -- Check_Fortran_Logical --
1295 ---------------------------
1297 procedure Check_Fortran_Logical is
1298 Logical : constant Entity_Id := Etype (Formal);
1301 -- Note: this is very incomplete, e.g. it does not handle arrays
1302 -- of logical values. This is really not the right approach at all???)
1305 if Convention (Subp) = Convention_Fortran
1306 and then Root_Type (Etype (Formal)) = Standard_Boolean
1307 and then Ekind (Formal) /= E_In_Parameter
1309 Var := Make_Var (Actual);
1310 Append_To (Post_Call,
1311 Make_Assignment_Statement (Loc,
1312 Name => New_Occurrence_Of (Var, Loc),
1314 Unchecked_Convert_To (
1317 Left_Opnd => New_Occurrence_Of (Var, Loc),
1319 Unchecked_Convert_To (
1321 New_Occurrence_Of (Standard_False, Loc))))));
1323 end Check_Fortran_Logical;
1329 function Is_Legal_Copy return Boolean is
1331 -- An attempt to copy a value of such a type can only occur if
1332 -- representation clauses give the actual a misaligned address.
1334 if Is_By_Reference_Type (Etype (Formal)) then
1336 ("misaligned actual cannot be passed by reference", Actual);
1339 -- For users of Starlet, we assume that the specification of by-
1340 -- reference mechanism is mandatory. This may lead to unaligned
1341 -- objects but at least for DEC legacy code it is known to work.
1342 -- The warning will alert users of this code that a problem may
1345 elsif Mechanism (Formal) = By_Reference
1346 and then Is_Valued_Procedure (Scope (Formal))
1349 ("by_reference actual may be misaligned?", Actual);
1361 function Make_Var (Actual : Node_Id) return Entity_Id is
1365 if Is_Entity_Name (Actual) then
1366 return Entity (Actual);
1370 Make_Defining_Identifier (Loc,
1371 Chars => New_Internal_Name ('T'));
1374 Make_Object_Renaming_Declaration (Loc,
1375 Defining_Identifier => Var,
1377 New_Occurrence_Of (Etype (Actual), Loc),
1378 Name => Relocate_Node (Actual));
1380 Insert_Action (N, N_Node);
1385 -------------------------
1386 -- Reset_Packed_Prefix --
1387 -------------------------
1389 procedure Reset_Packed_Prefix is
1390 Pfx : Node_Id := Actual;
1393 Set_Analyzed (Pfx, False);
1395 not Nkind_In (Pfx, N_Selected_Component, N_Indexed_Component);
1396 Pfx := Prefix (Pfx);
1398 end Reset_Packed_Prefix;
1400 -- Start of processing for Expand_Actuals
1403 Post_Call := New_List;
1405 Formal := First_Formal (Subp);
1406 Actual := First_Actual (N);
1407 while Present (Formal) loop
1408 E_Formal := Etype (Formal);
1410 if Is_Scalar_Type (E_Formal)
1411 or else Nkind (Actual) = N_Slice
1413 Check_Fortran_Logical;
1417 elsif Ekind (Formal) /= E_Out_Parameter then
1419 -- The unusual case of the current instance of a protected type
1420 -- requires special handling. This can only occur in the context
1421 -- of a call within the body of a protected operation.
1423 if Is_Entity_Name (Actual)
1424 and then Ekind (Entity (Actual)) = E_Protected_Type
1425 and then In_Open_Scopes (Entity (Actual))
1427 if Scope (Subp) /= Entity (Actual) then
1428 Error_Msg_N ("operation outside protected type may not "
1429 & "call back its protected operations?", Actual);
1433 Expand_Protected_Object_Reference (N, Entity (Actual)));
1436 -- Ada 2005 (AI-318-02): If the actual parameter is a call to a
1437 -- build-in-place function, then a temporary return object needs
1438 -- to be created and access to it must be passed to the function.
1439 -- Currently we limit such functions to those with inherently
1440 -- limited result subtypes, but eventually we plan to expand the
1441 -- functions that are treated as build-in-place to include other
1442 -- composite result types.
1444 if Ada_Version >= Ada_05
1445 and then Is_Build_In_Place_Function_Call (Actual)
1447 Make_Build_In_Place_Call_In_Anonymous_Context (Actual);
1450 Apply_Constraint_Check (Actual, E_Formal);
1452 -- Out parameter case. No constraint checks on access type
1455 elsif Is_Access_Type (E_Formal) then
1460 elsif Has_Discriminants (Base_Type (E_Formal))
1461 or else Has_Non_Null_Base_Init_Proc (E_Formal)
1463 Apply_Constraint_Check (Actual, E_Formal);
1468 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
1471 -- Processing for IN-OUT and OUT parameters
1473 if Ekind (Formal) /= E_In_Parameter then
1475 -- For type conversions of arrays, apply length/range checks
1477 if Is_Array_Type (E_Formal)
1478 and then Nkind (Actual) = N_Type_Conversion
1480 if Is_Constrained (E_Formal) then
1481 Apply_Length_Check (Expression (Actual), E_Formal);
1483 Apply_Range_Check (Expression (Actual), E_Formal);
1487 -- If argument is a type conversion for a type that is passed
1488 -- by copy, then we must pass the parameter by copy.
1490 if Nkind (Actual) = N_Type_Conversion
1492 (Is_Numeric_Type (E_Formal)
1493 or else Is_Access_Type (E_Formal)
1494 or else Is_Enumeration_Type (E_Formal)
1495 or else Is_Bit_Packed_Array (Etype (Formal))
1496 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
1498 -- Also pass by copy if change of representation
1500 or else not Same_Representation
1502 Etype (Expression (Actual))))
1504 Add_Call_By_Copy_Code;
1506 -- References to components of bit packed arrays are expanded
1507 -- at this point, rather than at the point of analysis of the
1508 -- actuals, to handle the expansion of the assignment to
1509 -- [in] out parameters.
1511 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1512 Add_Simple_Call_By_Copy_Code;
1514 -- If a non-scalar actual is possibly bit-aligned, we need a copy
1515 -- because the back-end cannot cope with such objects. In other
1516 -- cases where alignment forces a copy, the back-end generates
1517 -- it properly. It should not be generated unconditionally in the
1518 -- front-end because it does not know precisely the alignment
1519 -- requirements of the target, and makes too conservative an
1520 -- estimate, leading to superfluous copies or spurious errors
1521 -- on by-reference parameters.
1523 elsif Nkind (Actual) = N_Selected_Component
1525 Component_May_Be_Bit_Aligned (Entity (Selector_Name (Actual)))
1526 and then not Represented_As_Scalar (Etype (Formal))
1528 Add_Simple_Call_By_Copy_Code;
1530 -- References to slices of bit packed arrays are expanded
1532 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1533 Add_Call_By_Copy_Code;
1535 -- References to possibly unaligned slices of arrays are expanded
1537 elsif Is_Possibly_Unaligned_Slice (Actual) then
1538 Add_Call_By_Copy_Code;
1540 -- Deal with access types where the actual subtype and the
1541 -- formal subtype are not the same, requiring a check.
1543 -- It is necessary to exclude tagged types because of "downward
1544 -- conversion" errors and a strange assertion error in namet
1545 -- from gnatf in bug 1215-001 ???
1547 elsif Is_Access_Type (E_Formal)
1548 and then not Same_Type (E_Formal, Etype (Actual))
1549 and then not Is_Tagged_Type (Designated_Type (E_Formal))
1551 Add_Call_By_Copy_Code;
1553 -- If the actual is not a scalar and is marked for volatile
1554 -- treatment, whereas the formal is not volatile, then pass
1555 -- by copy unless it is a by-reference type.
1557 elsif Is_Entity_Name (Actual)
1558 and then Treat_As_Volatile (Entity (Actual))
1559 and then not Is_By_Reference_Type (Etype (Actual))
1560 and then not Is_Scalar_Type (Etype (Entity (Actual)))
1561 and then not Treat_As_Volatile (E_Formal)
1563 Add_Call_By_Copy_Code;
1565 elsif Nkind (Actual) = N_Indexed_Component
1566 and then Is_Entity_Name (Prefix (Actual))
1567 and then Has_Volatile_Components (Entity (Prefix (Actual)))
1569 Add_Call_By_Copy_Code;
1572 -- Processing for IN parameters
1575 -- For IN parameters is in the packed array case, we expand an
1576 -- indexed component (the circuit in Exp_Ch4 deliberately left
1577 -- indexed components appearing as actuals untouched, so that
1578 -- the special processing above for the OUT and IN OUT cases
1579 -- could be performed. We could make the test in Exp_Ch4 more
1580 -- complex and have it detect the parameter mode, but it is
1581 -- easier simply to handle all cases here.)
1583 if Nkind (Actual) = N_Indexed_Component
1584 and then Is_Packed (Etype (Prefix (Actual)))
1586 Reset_Packed_Prefix;
1587 Expand_Packed_Element_Reference (Actual);
1589 -- If we have a reference to a bit packed array, we copy it,
1590 -- since the actual must be byte aligned.
1592 -- Is this really necessary in all cases???
1594 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1595 Add_Simple_Call_By_Copy_Code;
1597 -- If a non-scalar actual is possibly unaligned, we need a copy
1599 elsif Is_Possibly_Unaligned_Object (Actual)
1600 and then not Represented_As_Scalar (Etype (Formal))
1602 Add_Simple_Call_By_Copy_Code;
1604 -- Similarly, we have to expand slices of packed arrays here
1605 -- because the result must be byte aligned.
1607 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1608 Add_Call_By_Copy_Code;
1610 -- Only processing remaining is to pass by copy if this is a
1611 -- reference to a possibly unaligned slice, since the caller
1612 -- expects an appropriately aligned argument.
1614 elsif Is_Possibly_Unaligned_Slice (Actual) then
1615 Add_Call_By_Copy_Code;
1619 Next_Formal (Formal);
1620 Next_Actual (Actual);
1623 -- Find right place to put post call stuff if it is present
1625 if not Is_Empty_List (Post_Call) then
1627 -- If call is not a list member, it must be the triggering statement
1628 -- of a triggering alternative or an entry call alternative, and we
1629 -- can add the post call stuff to the corresponding statement list.
1631 if not Is_List_Member (N) then
1633 P : constant Node_Id := Parent (N);
1636 pragma Assert (Nkind_In (P, N_Triggering_Alternative,
1637 N_Entry_Call_Alternative));
1639 if Is_Non_Empty_List (Statements (P)) then
1640 Insert_List_Before_And_Analyze
1641 (First (Statements (P)), Post_Call);
1643 Set_Statements (P, Post_Call);
1647 -- Otherwise, normal case where N is in a statement sequence,
1648 -- just put the post-call stuff after the call statement.
1651 Insert_Actions_After (N, Post_Call);
1655 -- The call node itself is re-analyzed in Expand_Call
1663 -- This procedure handles expansion of function calls and procedure call
1664 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1665 -- Expand_N_Procedure_Call_Statement. Processing for calls includes:
1667 -- Replace call to Raise_Exception by Raise_Exception always if possible
1668 -- Provide values of actuals for all formals in Extra_Formals list
1669 -- Replace "call" to enumeration literal function by literal itself
1670 -- Rewrite call to predefined operator as operator
1671 -- Replace actuals to in-out parameters that are numeric conversions,
1672 -- with explicit assignment to temporaries before and after the call.
1673 -- Remove optional actuals if First_Optional_Parameter specified.
1675 -- Note that the list of actuals has been filled with default expressions
1676 -- during semantic analysis of the call. Only the extra actuals required
1677 -- for the 'Constrained attribute and for accessibility checks are added
1680 procedure Expand_Call (N : Node_Id) is
1681 Loc : constant Source_Ptr := Sloc (N);
1682 Extra_Actuals : List_Id := No_List;
1683 Prev : Node_Id := Empty;
1685 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1686 -- Adds one entry to the end of the actual parameter list. Used for
1687 -- default parameters and for extra actuals (for Extra_Formals). The
1688 -- argument is an N_Parameter_Association node.
1690 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1691 -- Adds an extra actual to the list of extra actuals. Expr is the
1692 -- expression for the value of the actual, EF is the entity for the
1695 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1696 -- Within an instance, a type derived from a non-tagged formal derived
1697 -- type inherits from the original parent, not from the actual. This is
1698 -- tested in 4723-003. The current derivation mechanism has the derived
1699 -- type inherit from the actual, which is only correct outside of the
1700 -- instance. If the subprogram is inherited, we test for this particular
1701 -- case through a convoluted tree traversal before setting the proper
1702 -- subprogram to be called.
1704 --------------------------
1705 -- Add_Actual_Parameter --
1706 --------------------------
1708 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1709 Actual_Expr : constant Node_Id :=
1710 Explicit_Actual_Parameter (Insert_Param);
1713 -- Case of insertion is first named actual
1715 if No (Prev) or else
1716 Nkind (Parent (Prev)) /= N_Parameter_Association
1718 Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
1719 Set_First_Named_Actual (N, Actual_Expr);
1722 if No (Parameter_Associations (N)) then
1723 Set_Parameter_Associations (N, New_List);
1724 Append (Insert_Param, Parameter_Associations (N));
1727 Insert_After (Prev, Insert_Param);
1730 -- Case of insertion is not first named actual
1733 Set_Next_Named_Actual
1734 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1735 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1736 Append (Insert_Param, Parameter_Associations (N));
1739 Prev := Actual_Expr;
1740 end Add_Actual_Parameter;
1742 ----------------------
1743 -- Add_Extra_Actual --
1744 ----------------------
1746 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1747 Loc : constant Source_Ptr := Sloc (Expr);
1750 if Extra_Actuals = No_List then
1751 Extra_Actuals := New_List;
1752 Set_Parent (Extra_Actuals, N);
1755 Append_To (Extra_Actuals,
1756 Make_Parameter_Association (Loc,
1757 Explicit_Actual_Parameter => Expr,
1759 Make_Identifier (Loc, Chars (EF))));
1761 Analyze_And_Resolve (Expr, Etype (EF));
1762 end Add_Extra_Actual;
1764 ---------------------------
1765 -- Inherited_From_Formal --
1766 ---------------------------
1768 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1770 Gen_Par : Entity_Id;
1771 Gen_Prim : Elist_Id;
1776 -- If the operation is inherited, it is attached to the corresponding
1777 -- type derivation. If the parent in the derivation is a generic
1778 -- actual, it is a subtype of the actual, and we have to recover the
1779 -- original derived type declaration to find the proper parent.
1781 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1782 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1783 or else Nkind (Type_Definition (Original_Node (Parent (S)))) /=
1784 N_Derived_Type_Definition
1785 or else not In_Instance
1792 (Type_Definition (Original_Node (Parent (S)))));
1794 if Nkind (Indic) = N_Subtype_Indication then
1795 Par := Entity (Subtype_Mark (Indic));
1797 Par := Entity (Indic);
1801 if not Is_Generic_Actual_Type (Par)
1802 or else Is_Tagged_Type (Par)
1803 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1804 or else not In_Open_Scopes (Scope (Par))
1809 Gen_Par := Generic_Parent_Type (Parent (Par));
1812 -- If the actual has no generic parent type, the formal is not
1813 -- a formal derived type, so nothing to inherit.
1815 if No (Gen_Par) then
1819 -- If the generic parent type is still the generic type, this is a
1820 -- private formal, not a derived formal, and there are no operations
1821 -- inherited from the formal.
1823 if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
1827 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
1829 Elmt := First_Elmt (Gen_Prim);
1830 while Present (Elmt) loop
1831 if Chars (Node (Elmt)) = Chars (S) then
1837 F1 := First_Formal (S);
1838 F2 := First_Formal (Node (Elmt));
1840 and then Present (F2)
1842 if Etype (F1) = Etype (F2)
1843 or else Etype (F2) = Gen_Par
1849 exit; -- not the right subprogram
1861 raise Program_Error;
1862 end Inherited_From_Formal;
1866 Remote : constant Boolean := Is_Remote_Call (N);
1869 Orig_Subp : Entity_Id := Empty;
1870 Param_Count : Natural := 0;
1871 Parent_Formal : Entity_Id;
1872 Parent_Subp : Entity_Id;
1876 Prev_Orig : Node_Id;
1877 -- Original node for an actual, which may have been rewritten. If the
1878 -- actual is a function call that has been transformed from a selected
1879 -- component, the original node is unanalyzed. Otherwise, it carries
1880 -- semantic information used to generate additional actuals.
1882 CW_Interface_Formals_Present : Boolean := False;
1884 -- Start of processing for Expand_Call
1887 -- Ignore if previous error
1889 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1893 -- Call using access to subprogram with explicit dereference
1895 if Nkind (Name (N)) = N_Explicit_Dereference then
1896 Subp := Etype (Name (N));
1897 Parent_Subp := Empty;
1899 -- Case of call to simple entry, where the Name is a selected component
1900 -- whose prefix is the task, and whose selector name is the entry name
1902 elsif Nkind (Name (N)) = N_Selected_Component then
1903 Subp := Entity (Selector_Name (Name (N)));
1904 Parent_Subp := Empty;
1906 -- Case of call to member of entry family, where Name is an indexed
1907 -- component, with the prefix being a selected component giving the
1908 -- task and entry family name, and the index being the entry index.
1910 elsif Nkind (Name (N)) = N_Indexed_Component then
1911 Subp := Entity (Selector_Name (Prefix (Name (N))));
1912 Parent_Subp := Empty;
1917 Subp := Entity (Name (N));
1918 Parent_Subp := Alias (Subp);
1920 -- Replace call to Raise_Exception by call to Raise_Exception_Always
1921 -- if we can tell that the first parameter cannot possibly be null.
1922 -- This helps optimization and also generation of warnings.
1924 -- We do not do this if Raise_Exception_Always does not exist, which
1925 -- can happen in configurable run time profiles which provide only a
1926 -- Raise_Exception, which is in fact an unconditional raise anyway.
1928 if Is_RTE (Subp, RE_Raise_Exception)
1929 and then RTE_Available (RE_Raise_Exception_Always)
1932 FA : constant Node_Id := Original_Node (First_Actual (N));
1935 -- The case we catch is where the first argument is obtained
1936 -- using the Identity attribute (which must always be
1939 if Nkind (FA) = N_Attribute_Reference
1940 and then Attribute_Name (FA) = Name_Identity
1942 Subp := RTE (RE_Raise_Exception_Always);
1943 Set_Name (N, New_Occurrence_Of (Subp, Loc));
1948 if Ekind (Subp) = E_Entry then
1949 Parent_Subp := Empty;
1953 -- Ada 2005 (AI-345): We have a procedure call as a triggering
1954 -- alternative in an asynchronous select or as an entry call in
1955 -- a conditional or timed select. Check whether the procedure call
1956 -- is a renaming of an entry and rewrite it as an entry call.
1958 if Ada_Version >= Ada_05
1959 and then Nkind (N) = N_Procedure_Call_Statement
1961 ((Nkind (Parent (N)) = N_Triggering_Alternative
1962 and then Triggering_Statement (Parent (N)) = N)
1964 (Nkind (Parent (N)) = N_Entry_Call_Alternative
1965 and then Entry_Call_Statement (Parent (N)) = N))
1969 Ren_Root : Entity_Id := Subp;
1972 -- This may be a chain of renamings, find the root
1974 if Present (Alias (Ren_Root)) then
1975 Ren_Root := Alias (Ren_Root);
1978 if Present (Original_Node (Parent (Parent (Ren_Root)))) then
1979 Ren_Decl := Original_Node (Parent (Parent (Ren_Root)));
1981 if Nkind (Ren_Decl) = N_Subprogram_Renaming_Declaration then
1983 Make_Entry_Call_Statement (Loc,
1985 New_Copy_Tree (Name (Ren_Decl)),
1986 Parameter_Associations =>
1987 New_Copy_List_Tree (Parameter_Associations (N))));
1995 -- First step, compute extra actuals, corresponding to any
1996 -- Extra_Formals present. Note that we do not access Extra_Formals
1997 -- directly, instead we simply note the presence of the extra
1998 -- formals as we process the regular formals and collect the
1999 -- corresponding actuals in Extra_Actuals.
2001 -- We also generate any required range checks for actuals as we go
2002 -- through the loop, since this is a convenient place to do this.
2004 Formal := First_Formal (Subp);
2005 Actual := First_Actual (N);
2007 while Present (Formal) loop
2009 -- Generate range check if required (not activated yet ???)
2011 -- if Do_Range_Check (Actual) then
2012 -- Set_Do_Range_Check (Actual, False);
2013 -- Generate_Range_Check
2014 -- (Actual, Etype (Formal), CE_Range_Check_Failed);
2017 -- Prepare to examine current entry
2020 Prev_Orig := Original_Node (Prev);
2022 -- The original actual may have been a call written in prefix
2023 -- form, and rewritten before analysis.
2025 if not Analyzed (Prev_Orig)
2026 and then Nkind_In (Actual, N_Function_Call, N_Identifier)
2031 -- Ada 2005 (AI-251): Check if any formal is a class-wide interface
2032 -- to expand it in a further round.
2034 CW_Interface_Formals_Present :=
2035 CW_Interface_Formals_Present
2037 (Ekind (Etype (Formal)) = E_Class_Wide_Type
2038 and then Is_Interface (Etype (Etype (Formal))))
2040 (Ekind (Etype (Formal)) = E_Anonymous_Access_Type
2041 and then Is_Interface (Directly_Designated_Type
2042 (Etype (Etype (Formal)))));
2044 -- Create possible extra actual for constrained case. Usually, the
2045 -- extra actual is of the form actual'constrained, but since this
2046 -- attribute is only available for unconstrained records, TRUE is
2047 -- expanded if the type of the formal happens to be constrained (for
2048 -- instance when this procedure is inherited from an unconstrained
2049 -- record to a constrained one) or if the actual has no discriminant
2050 -- (its type is constrained). An exception to this is the case of a
2051 -- private type without discriminants. In this case we pass FALSE
2052 -- because the object has underlying discriminants with defaults.
2054 if Present (Extra_Constrained (Formal)) then
2055 if Ekind (Etype (Prev)) in Private_Kind
2056 and then not Has_Discriminants (Base_Type (Etype (Prev)))
2059 New_Occurrence_Of (Standard_False, Loc),
2060 Extra_Constrained (Formal));
2062 elsif Is_Constrained (Etype (Formal))
2063 or else not Has_Discriminants (Etype (Prev))
2066 New_Occurrence_Of (Standard_True, Loc),
2067 Extra_Constrained (Formal));
2069 -- Do not produce extra actuals for Unchecked_Union parameters.
2070 -- Jump directly to the end of the loop.
2072 elsif Is_Unchecked_Union (Base_Type (Etype (Actual))) then
2073 goto Skip_Extra_Actual_Generation;
2076 -- If the actual is a type conversion, then the constrained
2077 -- test applies to the actual, not the target type.
2083 -- Test for unchecked conversions as well, which can occur
2084 -- as out parameter actuals on calls to stream procedures.
2087 while Nkind_In (Act_Prev, N_Type_Conversion,
2088 N_Unchecked_Type_Conversion)
2090 Act_Prev := Expression (Act_Prev);
2093 -- If the expression is a conversion of a dereference,
2094 -- this is internally generated code that manipulates
2095 -- addresses, e.g. when building interface tables. No
2096 -- check should occur in this case, and the discriminated
2097 -- object is not directly a hand.
2099 if not Comes_From_Source (Actual)
2100 and then Nkind (Actual) = N_Unchecked_Type_Conversion
2101 and then Nkind (Act_Prev) = N_Explicit_Dereference
2104 (New_Occurrence_Of (Standard_False, Loc),
2105 Extra_Constrained (Formal));
2109 (Make_Attribute_Reference (Sloc (Prev),
2111 Duplicate_Subexpr_No_Checks
2112 (Act_Prev, Name_Req => True),
2113 Attribute_Name => Name_Constrained),
2114 Extra_Constrained (Formal));
2120 -- Create possible extra actual for accessibility level
2122 if Present (Extra_Accessibility (Formal)) then
2124 -- Ada 2005 (AI-252): If the actual was rewritten as an Access
2125 -- attribute, then the original actual may be an aliased object
2126 -- occurring as the prefix in a call using "Object.Operation"
2127 -- notation. In that case we must pass the level of the object,
2128 -- so Prev_Orig is reset to Prev and the attribute will be
2129 -- processed by the code for Access attributes further below.
2131 if Prev_Orig /= Prev
2132 and then Nkind (Prev) = N_Attribute_Reference
2134 Get_Attribute_Id (Attribute_Name (Prev)) = Attribute_Access
2135 and then Is_Aliased_View (Prev_Orig)
2140 -- Ada 2005 (AI-251): Thunks must propagate the extra actuals
2141 -- of accessibility levels.
2143 if Ekind (Current_Scope) in Subprogram_Kind
2144 and then Is_Thunk (Current_Scope)
2147 Parm_Ent : Entity_Id;
2150 if Is_Controlling_Actual (Actual) then
2152 -- Find the corresponding actual of the thunk
2154 Parm_Ent := First_Entity (Current_Scope);
2155 for J in 2 .. Param_Count loop
2156 Next_Entity (Parm_Ent);
2159 else pragma Assert (Is_Entity_Name (Actual));
2160 Parm_Ent := Entity (Actual);
2164 (New_Occurrence_Of (Extra_Accessibility (Parm_Ent), Loc),
2165 Extra_Accessibility (Formal));
2168 elsif Is_Entity_Name (Prev_Orig) then
2170 -- When passing an access parameter, or a renaming of an access
2171 -- parameter, as the actual to another access parameter we need
2172 -- to pass along the actual's own access level parameter. This
2173 -- is done if we are within the scope of the formal access
2174 -- parameter (if this is an inlined body the extra formal is
2177 if (Is_Formal (Entity (Prev_Orig))
2179 (Present (Renamed_Object (Entity (Prev_Orig)))
2181 Is_Entity_Name (Renamed_Object (Entity (Prev_Orig)))
2184 (Entity (Renamed_Object (Entity (Prev_Orig))))))
2185 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
2186 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
2189 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
2192 pragma Assert (Present (Parm_Ent));
2194 if Present (Extra_Accessibility (Parm_Ent)) then
2197 (Extra_Accessibility (Parm_Ent), Loc),
2198 Extra_Accessibility (Formal));
2200 -- If the actual access parameter does not have an
2201 -- associated extra formal providing its scope level,
2202 -- then treat the actual as having library-level
2207 (Make_Integer_Literal (Loc,
2208 Intval => Scope_Depth (Standard_Standard)),
2209 Extra_Accessibility (Formal));
2213 -- The actual is a normal access value, so just pass the level
2214 -- of the actual's access type.
2218 (Make_Integer_Literal (Loc,
2219 Intval => Type_Access_Level (Etype (Prev_Orig))),
2220 Extra_Accessibility (Formal));
2223 -- All cases other than thunks
2226 case Nkind (Prev_Orig) is
2228 when N_Attribute_Reference =>
2229 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
2231 -- For X'Access, pass on the level of the prefix X
2233 when Attribute_Access =>
2235 Make_Integer_Literal (Loc,
2237 Object_Access_Level (Prefix (Prev_Orig))),
2238 Extra_Accessibility (Formal));
2240 -- Treat the unchecked attributes as library-level
2242 when Attribute_Unchecked_Access |
2243 Attribute_Unrestricted_Access =>
2245 Make_Integer_Literal (Loc,
2246 Intval => Scope_Depth (Standard_Standard)),
2247 Extra_Accessibility (Formal));
2249 -- No other cases of attributes returning access
2250 -- values that can be passed to access parameters
2253 raise Program_Error;
2257 -- For allocators we pass the level of the execution of
2258 -- the called subprogram, which is one greater than the
2259 -- current scope level.
2263 Make_Integer_Literal (Loc,
2264 Scope_Depth (Current_Scope) + 1),
2265 Extra_Accessibility (Formal));
2267 -- For other cases we simply pass the level of the
2268 -- actual's access type.
2272 Make_Integer_Literal (Loc,
2273 Intval => Type_Access_Level (Etype (Prev_Orig))),
2274 Extra_Accessibility (Formal));
2280 -- Perform the check of 4.6(49) that prevents a null value from being
2281 -- passed as an actual to an access parameter. Note that the check is
2282 -- elided in the common cases of passing an access attribute or
2283 -- access parameter as an actual. Also, we currently don't enforce
2284 -- this check for expander-generated actuals and when -gnatdj is set.
2286 if Ada_Version >= Ada_05 then
2288 -- Ada 2005 (AI-231): Check null-excluding access types
2290 if Is_Access_Type (Etype (Formal))
2291 and then Can_Never_Be_Null (Etype (Formal))
2292 and then Nkind (Prev) /= N_Raise_Constraint_Error
2293 and then (Known_Null (Prev)
2294 or else not Can_Never_Be_Null (Etype (Prev)))
2296 Install_Null_Excluding_Check (Prev);
2299 -- Ada_Version < Ada_05
2302 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
2303 or else Access_Checks_Suppressed (Subp)
2307 elsif Debug_Flag_J then
2310 elsif not Comes_From_Source (Prev) then
2313 elsif Is_Entity_Name (Prev)
2314 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
2318 elsif Nkind_In (Prev, N_Allocator, N_Attribute_Reference) then
2321 -- Suppress null checks when passing to access parameters of Java
2322 -- and CIL subprograms. (Should this be done for other foreign
2323 -- conventions as well ???)
2325 elsif Convention (Subp) = Convention_Java
2326 or else Convention (Subp) = Convention_CIL
2331 Install_Null_Excluding_Check (Prev);
2335 -- Perform appropriate validity checks on parameters that
2338 if Validity_Checks_On then
2339 if (Ekind (Formal) = E_In_Parameter
2340 and then Validity_Check_In_Params)
2342 (Ekind (Formal) = E_In_Out_Parameter
2343 and then Validity_Check_In_Out_Params)
2345 -- If the actual is an indexed component of a packed type (or
2346 -- is an indexed or selected component whose prefix recursively
2347 -- meets this condition), it has not been expanded yet. It will
2348 -- be copied in the validity code that follows, and has to be
2349 -- expanded appropriately, so reanalyze it.
2351 -- What we do is just to unset analyzed bits on prefixes till
2352 -- we reach something that does not have a prefix.
2359 while Nkind_In (Nod, N_Indexed_Component,
2360 N_Selected_Component)
2362 Set_Analyzed (Nod, False);
2363 Nod := Prefix (Nod);
2367 Ensure_Valid (Actual);
2371 -- For IN OUT and OUT parameters, ensure that subscripts are valid
2372 -- since this is a left side reference. We only do this for calls
2373 -- from the source program since we assume that compiler generated
2374 -- calls explicitly generate any required checks. We also need it
2375 -- only if we are doing standard validity checks, since clearly it
2376 -- is not needed if validity checks are off, and in subscript
2377 -- validity checking mode, all indexed components are checked with
2378 -- a call directly from Expand_N_Indexed_Component.
2380 if Comes_From_Source (N)
2381 and then Ekind (Formal) /= E_In_Parameter
2382 and then Validity_Checks_On
2383 and then Validity_Check_Default
2384 and then not Validity_Check_Subscripts
2386 Check_Valid_Lvalue_Subscripts (Actual);
2389 -- Mark any scalar OUT parameter that is a simple variable as no
2390 -- longer known to be valid (unless the type is always valid). This
2391 -- reflects the fact that if an OUT parameter is never set in a
2392 -- procedure, then it can become invalid on the procedure return.
2394 if Ekind (Formal) = E_Out_Parameter
2395 and then Is_Entity_Name (Actual)
2396 and then Ekind (Entity (Actual)) = E_Variable
2397 and then not Is_Known_Valid (Etype (Actual))
2399 Set_Is_Known_Valid (Entity (Actual), False);
2402 -- For an OUT or IN OUT parameter, if the actual is an entity, then
2403 -- clear current values, since they can be clobbered. We are probably
2404 -- doing this in more places than we need to, but better safe than
2405 -- sorry when it comes to retaining bad current values!
2407 if Ekind (Formal) /= E_In_Parameter
2408 and then Is_Entity_Name (Actual)
2409 and then Present (Entity (Actual))
2412 Ent : constant Entity_Id := Entity (Actual);
2416 -- For an OUT or IN OUT parameter that is an assignable entity,
2417 -- we do not want to clobber the Last_Assignment field, since
2418 -- if it is set, it was precisely because it is indeed an OUT
2419 -- or IN OUT parameter!
2421 if (Ekind (Formal) = E_Out_Parameter
2423 Ekind (Formal) = E_In_Out_Parameter)
2424 and then Is_Assignable (Ent)
2426 Sav := Last_Assignment (Ent);
2427 Kill_Current_Values (Ent);
2428 Set_Last_Assignment (Ent, Sav);
2430 -- For all other cases, just kill the current values
2433 Kill_Current_Values (Ent);
2438 -- If the formal is class wide and the actual is an aggregate, force
2439 -- evaluation so that the back end who does not know about class-wide
2440 -- type, does not generate a temporary of the wrong size.
2442 if not Is_Class_Wide_Type (Etype (Formal)) then
2445 elsif Nkind (Actual) = N_Aggregate
2446 or else (Nkind (Actual) = N_Qualified_Expression
2447 and then Nkind (Expression (Actual)) = N_Aggregate)
2449 Force_Evaluation (Actual);
2452 -- In a remote call, if the formal is of a class-wide type, check
2453 -- that the actual meets the requirements described in E.4(18).
2455 if Remote and then Is_Class_Wide_Type (Etype (Formal)) then
2456 Insert_Action (Actual,
2457 Make_Transportable_Check (Loc,
2458 Duplicate_Subexpr_Move_Checks (Actual)));
2461 -- This label is required when skipping extra actual generation for
2462 -- Unchecked_Union parameters.
2464 <<Skip_Extra_Actual_Generation>>
2466 Param_Count := Param_Count + 1;
2467 Next_Actual (Actual);
2468 Next_Formal (Formal);
2471 -- If we are expanding a rhs of an assignment we need to check if tag
2472 -- propagation is needed. You might expect this processing to be in
2473 -- Analyze_Assignment but has to be done earlier (bottom-up) because the
2474 -- assignment might be transformed to a declaration for an unconstrained
2475 -- value if the expression is classwide.
2477 if Nkind (N) = N_Function_Call
2478 and then Is_Tag_Indeterminate (N)
2479 and then Is_Entity_Name (Name (N))
2482 Ass : Node_Id := Empty;
2485 if Nkind (Parent (N)) = N_Assignment_Statement then
2488 elsif Nkind (Parent (N)) = N_Qualified_Expression
2489 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
2491 Ass := Parent (Parent (N));
2493 elsif Nkind (Parent (N)) = N_Explicit_Dereference
2494 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
2496 Ass := Parent (Parent (N));
2500 and then Is_Class_Wide_Type (Etype (Name (Ass)))
2502 if Is_Access_Type (Etype (N)) then
2503 if Designated_Type (Etype (N)) /=
2504 Root_Type (Etype (Name (Ass)))
2507 ("tag-indeterminate expression "
2508 & " must have designated type& (RM 5.2 (6))",
2509 N, Root_Type (Etype (Name (Ass))));
2511 Propagate_Tag (Name (Ass), N);
2514 elsif Etype (N) /= Root_Type (Etype (Name (Ass))) then
2516 ("tag-indeterminate expression must have type&"
2517 & "(RM 5.2 (6))", N, Root_Type (Etype (Name (Ass))));
2520 Propagate_Tag (Name (Ass), N);
2523 -- The call will be rewritten as a dispatching call, and
2524 -- expanded as such.
2531 -- Ada 2005 (AI-251): If some formal is a class-wide interface, expand
2532 -- it to point to the correct secondary virtual table
2534 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement)
2535 and then CW_Interface_Formals_Present
2537 Expand_Interface_Actuals (N);
2540 -- Deals with Dispatch_Call if we still have a call, before expanding
2541 -- extra actuals since this will be done on the re-analysis of the
2542 -- dispatching call. Note that we do not try to shorten the actual
2543 -- list for a dispatching call, it would not make sense to do so.
2544 -- Expansion of dispatching calls is suppressed when VM_Target, because
2545 -- the VM back-ends directly handle the generation of dispatching
2546 -- calls and would have to undo any expansion to an indirect call.
2548 if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement)
2549 and then Present (Controlling_Argument (N))
2550 and then VM_Target = No_VM
2552 Expand_Dispatching_Call (N);
2554 -- The following return is worrisome. Is it really OK to
2555 -- skip all remaining processing in this procedure ???
2559 -- Similarly, expand calls to RCI subprograms on which pragma
2560 -- All_Calls_Remote applies. The rewriting will be reanalyzed
2561 -- later. Do this only when the call comes from source since we do
2562 -- not want such a rewriting to occur in expanded code.
2564 elsif Is_All_Remote_Call (N) then
2565 Expand_All_Calls_Remote_Subprogram_Call (N);
2567 -- Similarly, do not add extra actuals for an entry call whose entity
2568 -- is a protected procedure, or for an internal protected subprogram
2569 -- call, because it will be rewritten as a protected subprogram call
2570 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
2572 elsif Is_Protected_Type (Scope (Subp))
2573 and then (Ekind (Subp) = E_Procedure
2574 or else Ekind (Subp) = E_Function)
2578 -- During that loop we gathered the extra actuals (the ones that
2579 -- correspond to Extra_Formals), so now they can be appended.
2582 while Is_Non_Empty_List (Extra_Actuals) loop
2583 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
2587 -- At this point we have all the actuals, so this is the point at
2588 -- which the various expansion activities for actuals is carried out.
2590 Expand_Actuals (N, Subp);
2592 -- If the subprogram is a renaming, or if it is inherited, replace it
2593 -- in the call with the name of the actual subprogram being called.
2594 -- If this is a dispatching call, the run-time decides what to call.
2595 -- The Alias attribute does not apply to entries.
2597 if Nkind (N) /= N_Entry_Call_Statement
2598 and then No (Controlling_Argument (N))
2599 and then Present (Parent_Subp)
2601 if Present (Inherited_From_Formal (Subp)) then
2602 Parent_Subp := Inherited_From_Formal (Subp);
2604 while Present (Alias (Parent_Subp)) loop
2605 Parent_Subp := Alias (Parent_Subp);
2609 -- The below setting of Entity is suspect, see F109-018 discussion???
2611 Set_Entity (Name (N), Parent_Subp);
2613 if Is_Abstract_Subprogram (Parent_Subp)
2614 and then not In_Instance
2617 ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
2620 -- Add an explicit conversion for parameter of the derived type.
2621 -- This is only done for scalar and access in-parameters. Others
2622 -- have been expanded in expand_actuals.
2624 Formal := First_Formal (Subp);
2625 Parent_Formal := First_Formal (Parent_Subp);
2626 Actual := First_Actual (N);
2628 -- It is not clear that conversion is needed for intrinsic
2629 -- subprograms, but it certainly is for those that are user-
2630 -- defined, and that can be inherited on derivation, namely
2631 -- unchecked conversion and deallocation.
2632 -- General case needs study ???
2634 if not Is_Intrinsic_Subprogram (Parent_Subp)
2635 or else Is_Generic_Instance (Parent_Subp)
2637 while Present (Formal) loop
2638 if Etype (Formal) /= Etype (Parent_Formal)
2639 and then Is_Scalar_Type (Etype (Formal))
2640 and then Ekind (Formal) = E_In_Parameter
2642 not Subtypes_Statically_Match
2643 (Etype (Parent_Formal), Etype (Actual))
2644 and then not Raises_Constraint_Error (Actual)
2647 OK_Convert_To (Etype (Parent_Formal),
2648 Relocate_Node (Actual)));
2651 Resolve (Actual, Etype (Parent_Formal));
2652 Enable_Range_Check (Actual);
2654 elsif Is_Access_Type (Etype (Formal))
2655 and then Base_Type (Etype (Parent_Formal)) /=
2656 Base_Type (Etype (Actual))
2658 if Ekind (Formal) /= E_In_Parameter then
2660 Convert_To (Etype (Parent_Formal),
2661 Relocate_Node (Actual)));
2664 Resolve (Actual, Etype (Parent_Formal));
2667 Ekind (Etype (Parent_Formal)) = E_Anonymous_Access_Type
2668 and then Designated_Type (Etype (Parent_Formal))
2670 Designated_Type (Etype (Actual))
2671 and then not Is_Controlling_Formal (Formal)
2673 -- This unchecked conversion is not necessary unless
2674 -- inlining is enabled, because in that case the type
2675 -- mismatch may become visible in the body about to be
2679 Unchecked_Convert_To (Etype (Parent_Formal),
2680 Relocate_Node (Actual)));
2683 Resolve (Actual, Etype (Parent_Formal));
2687 Next_Formal (Formal);
2688 Next_Formal (Parent_Formal);
2689 Next_Actual (Actual);
2694 Subp := Parent_Subp;
2697 -- Check for violation of No_Abort_Statements
2699 if Is_RTE (Subp, RE_Abort_Task) then
2700 Check_Restriction (No_Abort_Statements, N);
2702 -- Check for violation of No_Dynamic_Attachment
2704 elsif RTU_Loaded (Ada_Interrupts)
2705 and then (Is_RTE (Subp, RE_Is_Reserved) or else
2706 Is_RTE (Subp, RE_Is_Attached) or else
2707 Is_RTE (Subp, RE_Current_Handler) or else
2708 Is_RTE (Subp, RE_Attach_Handler) or else
2709 Is_RTE (Subp, RE_Exchange_Handler) or else
2710 Is_RTE (Subp, RE_Detach_Handler) or else
2711 Is_RTE (Subp, RE_Reference))
2713 Check_Restriction (No_Dynamic_Attachment, N);
2716 -- Deal with case where call is an explicit dereference
2718 if Nkind (Name (N)) = N_Explicit_Dereference then
2720 -- Handle case of access to protected subprogram type
2722 if Is_Access_Protected_Subprogram_Type
2723 (Base_Type (Etype (Prefix (Name (N)))))
2725 -- If this is a call through an access to protected operation,
2726 -- the prefix has the form (object'address, operation'access).
2727 -- Rewrite as a for other protected calls: the object is the
2728 -- first parameter of the list of actuals.
2735 Ptr : constant Node_Id := Prefix (Name (N));
2737 T : constant Entity_Id :=
2738 Equivalent_Type (Base_Type (Etype (Ptr)));
2740 D_T : constant Entity_Id :=
2741 Designated_Type (Base_Type (Etype (Ptr)));
2745 Make_Selected_Component (Loc,
2746 Prefix => Unchecked_Convert_To (T, Ptr),
2748 New_Occurrence_Of (First_Entity (T), Loc));
2751 Make_Selected_Component (Loc,
2752 Prefix => Unchecked_Convert_To (T, Ptr),
2754 New_Occurrence_Of (Next_Entity (First_Entity (T)), Loc));
2757 Make_Explicit_Dereference (Loc,
2760 if Present (Parameter_Associations (N)) then
2761 Parm := Parameter_Associations (N);
2766 Prepend (Obj, Parm);
2768 if Etype (D_T) = Standard_Void_Type then
2770 Make_Procedure_Call_Statement (Loc,
2772 Parameter_Associations => Parm);
2775 Make_Function_Call (Loc,
2777 Parameter_Associations => Parm);
2780 Set_First_Named_Actual (Call, First_Named_Actual (N));
2781 Set_Etype (Call, Etype (D_T));
2783 -- We do not re-analyze the call to avoid infinite recursion.
2784 -- We analyze separately the prefix and the object, and set
2785 -- the checks on the prefix that would otherwise be emitted
2786 -- when resolving a call.
2790 Apply_Access_Check (Nam);
2797 -- If this is a call to an intrinsic subprogram, then perform the
2798 -- appropriate expansion to the corresponding tree node and we
2799 -- are all done (since after that the call is gone!)
2801 -- In the case where the intrinsic is to be processed by the back end,
2802 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
2803 -- since the idea in this case is to pass the call unchanged.
2804 -- If the intrinsic is an inherited unchecked conversion, and the
2805 -- derived type is the target type of the conversion, we must retain
2806 -- it as the return type of the expression. Otherwise the expansion
2807 -- below, which uses the parent operation, will yield the wrong type.
2809 if Is_Intrinsic_Subprogram (Subp) then
2810 Expand_Intrinsic_Call (N, Subp);
2812 if Nkind (N) = N_Unchecked_Type_Conversion
2813 and then Parent_Subp /= Orig_Subp
2814 and then Etype (Parent_Subp) /= Etype (Orig_Subp)
2816 Set_Etype (N, Etype (Orig_Subp));
2822 if Ekind (Subp) = E_Function
2823 or else Ekind (Subp) = E_Procedure
2825 if Is_Inlined (Subp) then
2827 Inlined_Subprogram : declare
2829 Must_Inline : Boolean := False;
2830 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
2831 Scop : constant Entity_Id := Scope (Subp);
2833 function In_Unfrozen_Instance return Boolean;
2834 -- If the subprogram comes from an instance in the same
2835 -- unit, and the instance is not yet frozen, inlining might
2836 -- trigger order-of-elaboration problems in gigi.
2838 --------------------------
2839 -- In_Unfrozen_Instance --
2840 --------------------------
2842 function In_Unfrozen_Instance return Boolean is
2848 and then S /= Standard_Standard
2850 if Is_Generic_Instance (S)
2851 and then Present (Freeze_Node (S))
2852 and then not Analyzed (Freeze_Node (S))
2861 end In_Unfrozen_Instance;
2863 -- Start of processing for Inlined_Subprogram
2866 -- Verify that the body to inline has already been seen, and
2867 -- that if the body is in the current unit the inlining does
2868 -- not occur earlier. This avoids order-of-elaboration problems
2871 -- This should be documented in sinfo/einfo ???
2874 or else Nkind (Spec) /= N_Subprogram_Declaration
2875 or else No (Body_To_Inline (Spec))
2877 Must_Inline := False;
2879 -- If this an inherited function that returns a private
2880 -- type, do not inline if the full view is an unconstrained
2881 -- array, because such calls cannot be inlined.
2883 elsif Present (Orig_Subp)
2884 and then Is_Array_Type (Etype (Orig_Subp))
2885 and then not Is_Constrained (Etype (Orig_Subp))
2887 Must_Inline := False;
2889 elsif In_Unfrozen_Instance then
2890 Must_Inline := False;
2893 Bod := Body_To_Inline (Spec);
2895 if (In_Extended_Main_Code_Unit (N)
2896 or else In_Extended_Main_Code_Unit (Parent (N))
2897 or else Has_Pragma_Inline_Always (Subp))
2898 and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
2900 Earlier_In_Extended_Unit (Sloc (Bod), Loc))
2902 Must_Inline := True;
2904 -- If we are compiling a package body that is not the main
2905 -- unit, it must be for inlining/instantiation purposes,
2906 -- in which case we inline the call to insure that the same
2907 -- temporaries are generated when compiling the body by
2908 -- itself. Otherwise link errors can occur.
2910 -- If the function being called is itself in the main unit,
2911 -- we cannot inline, because there is a risk of double
2912 -- elaboration and/or circularity: the inlining can make
2913 -- visible a private entity in the body of the main unit,
2914 -- that gigi will see before its sees its proper definition.
2916 elsif not (In_Extended_Main_Code_Unit (N))
2917 and then In_Package_Body
2919 Must_Inline := not In_Extended_Main_Source_Unit (Subp);
2924 Expand_Inlined_Call (N, Subp, Orig_Subp);
2927 -- Let the back end handle it
2929 Add_Inlined_Body (Subp);
2931 if Front_End_Inlining
2932 and then Nkind (Spec) = N_Subprogram_Declaration
2933 and then (In_Extended_Main_Code_Unit (N))
2934 and then No (Body_To_Inline (Spec))
2935 and then not Has_Completion (Subp)
2936 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
2939 ("cannot inline& (body not seen yet)?",
2943 end Inlined_Subprogram;
2947 -- Check for a protected subprogram. This is either an intra-object
2948 -- call, or a protected function call. Protected procedure calls are
2949 -- rewritten as entry calls and handled accordingly.
2951 -- In Ada 2005, this may be an indirect call to an access parameter
2952 -- that is an access_to_subprogram. In that case the anonymous type
2953 -- has a scope that is a protected operation, but the call is a
2956 Scop := Scope (Subp);
2958 if Nkind (N) /= N_Entry_Call_Statement
2959 and then Is_Protected_Type (Scop)
2960 and then Ekind (Subp) /= E_Subprogram_Type
2962 -- If the call is an internal one, it is rewritten as a call to
2963 -- to the corresponding unprotected subprogram.
2965 Expand_Protected_Subprogram_Call (N, Subp, Scop);
2968 -- Functions returning controlled objects need special attention
2969 -- If the return type is limited the context is an initialization
2970 -- and different processing applies.
2972 if Controlled_Type (Etype (Subp))
2973 and then not Is_Inherently_Limited_Type (Etype (Subp))
2974 and then not Is_Limited_Interface (Etype (Subp))
2976 Expand_Ctrl_Function_Call (N);
2979 -- Test for First_Optional_Parameter, and if so, truncate parameter
2980 -- list if there are optional parameters at the trailing end.
2981 -- Note we never delete procedures for call via a pointer.
2983 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
2984 and then Present (First_Optional_Parameter (Subp))
2987 Last_Keep_Arg : Node_Id;
2990 -- Last_Keep_Arg will hold the last actual that should be
2991 -- retained. If it remains empty at the end, it means that
2992 -- all parameters are optional.
2994 Last_Keep_Arg := Empty;
2996 -- Find first optional parameter, must be present since we
2997 -- checked the validity of the parameter before setting it.
2999 Formal := First_Formal (Subp);
3000 Actual := First_Actual (N);
3001 while Formal /= First_Optional_Parameter (Subp) loop
3002 Last_Keep_Arg := Actual;
3003 Next_Formal (Formal);
3004 Next_Actual (Actual);
3007 -- We have Formal and Actual pointing to the first potentially
3008 -- droppable argument. We can drop all the trailing arguments
3009 -- whose actual matches the default. Note that we know that all
3010 -- remaining formals have defaults, because we checked that this
3011 -- requirement was met before setting First_Optional_Parameter.
3013 -- We use Fully_Conformant_Expressions to check for identity
3014 -- between formals and actuals, which may miss some cases, but
3015 -- on the other hand, this is only an optimization (if we fail
3016 -- to truncate a parameter it does not affect functionality).
3017 -- So if the default is 3 and the actual is 1+2, we consider
3018 -- them unequal, which hardly seems worrisome.
3020 while Present (Formal) loop
3021 if not Fully_Conformant_Expressions
3022 (Actual, Default_Value (Formal))
3024 Last_Keep_Arg := Actual;
3027 Next_Formal (Formal);
3028 Next_Actual (Actual);
3031 -- If no arguments, delete entire list, this is the easy case
3033 if No (Last_Keep_Arg) then
3034 Set_Parameter_Associations (N, No_List);
3035 Set_First_Named_Actual (N, Empty);
3037 -- Case where at the last retained argument is positional. This
3038 -- is also an easy case, since the retained arguments are already
3039 -- in the right form, and we don't need to worry about the order
3040 -- of arguments that get eliminated.
3042 elsif Is_List_Member (Last_Keep_Arg) then
3043 while Present (Next (Last_Keep_Arg)) loop
3044 Discard_Node (Remove_Next (Last_Keep_Arg));
3047 Set_First_Named_Actual (N, Empty);
3049 -- This is the annoying case where the last retained argument
3050 -- is a named parameter. Since the original arguments are not
3051 -- in declaration order, we may have to delete some fairly
3052 -- random collection of arguments.
3060 -- First step, remove all the named parameters from the
3061 -- list (they are still chained using First_Named_Actual
3062 -- and Next_Named_Actual, so we have not lost them!)
3064 Temp := First (Parameter_Associations (N));
3066 -- Case of all parameters named, remove them all
3068 if Nkind (Temp) = N_Parameter_Association then
3069 while Is_Non_Empty_List (Parameter_Associations (N)) loop
3070 Temp := Remove_Head (Parameter_Associations (N));
3073 -- Case of mixed positional/named, remove named parameters
3076 while Nkind (Next (Temp)) /= N_Parameter_Association loop
3080 while Present (Next (Temp)) loop
3081 Remove (Next (Temp));
3085 -- Now we loop through the named parameters, till we get
3086 -- to the last one to be retained, adding them to the list.
3087 -- Note that the Next_Named_Actual list does not need to be
3088 -- touched since we are only reordering them on the actual
3089 -- parameter association list.
3091 Passoc := Parent (First_Named_Actual (N));
3093 Temp := Relocate_Node (Passoc);
3095 (Parameter_Associations (N), Temp);
3097 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
3098 Passoc := Parent (Next_Named_Actual (Passoc));
3101 Set_Next_Named_Actual (Temp, Empty);
3104 Temp := Next_Named_Actual (Passoc);
3105 exit when No (Temp);
3106 Set_Next_Named_Actual
3107 (Passoc, Next_Named_Actual (Parent (Temp)));
3114 -- Special processing for Ada 2005 AI-329, which requires a call to
3115 -- Raise_Exception to raise Constraint_Error if the Exception_Id is
3116 -- null. Note that we never need to do this in GNAT mode, or if the
3117 -- parameter to Raise_Exception is a use of Identity, since in these
3118 -- cases we know that the parameter is never null.
3120 -- Note: We must check that the node has not been inlined. This is
3121 -- required because under zfp the Raise_Exception subprogram has the
3122 -- pragma inline_always (and hence the call has been expanded above
3123 -- into a block containing the code of the subprogram).
3125 if Ada_Version >= Ada_05
3126 and then not GNAT_Mode
3127 and then Is_RTE (Subp, RE_Raise_Exception)
3128 and then Nkind (N) = N_Procedure_Call_Statement
3129 and then (Nkind (First_Actual (N)) /= N_Attribute_Reference
3130 or else Attribute_Name (First_Actual (N)) /= Name_Identity)
3133 RCE : constant Node_Id :=
3134 Make_Raise_Constraint_Error (Loc,
3135 Reason => CE_Null_Exception_Id);
3137 Insert_After (N, RCE);
3143 --------------------------
3144 -- Expand_Inlined_Call --
3145 --------------------------
3147 procedure Expand_Inlined_Call
3150 Orig_Subp : Entity_Id)
3152 Loc : constant Source_Ptr := Sloc (N);
3153 Is_Predef : constant Boolean :=
3154 Is_Predefined_File_Name
3155 (Unit_File_Name (Get_Source_Unit (Subp)));
3156 Orig_Bod : constant Node_Id :=
3157 Body_To_Inline (Unit_Declaration_Node (Subp));
3162 Decls : constant List_Id := New_List;
3163 Exit_Lab : Entity_Id := Empty;
3170 Ret_Type : Entity_Id;
3174 Temp_Typ : Entity_Id;
3176 Is_Unc : constant Boolean :=
3177 Is_Array_Type (Etype (Subp))
3178 and then not Is_Constrained (Etype (Subp));
3179 -- If the type returned by the function is unconstrained and the
3180 -- call can be inlined, special processing is required.
3182 function Is_Null_Procedure return Boolean;
3183 -- Predicate to recognize stubbed procedures and null procedures, for
3184 -- which there is no need for the full inlining mechanism.
3186 procedure Make_Exit_Label;
3187 -- Build declaration for exit label to be used in Return statements
3189 function Process_Formals (N : Node_Id) return Traverse_Result;
3190 -- Replace occurrence of a formal with the corresponding actual, or
3191 -- the thunk generated for it.
3193 function Process_Sloc (Nod : Node_Id) return Traverse_Result;
3194 -- If the call being expanded is that of an internal subprogram,
3195 -- set the sloc of the generated block to that of the call itself,
3196 -- so that the expansion is skipped by the -next- command in gdb.
3197 -- Same processing for a subprogram in a predefined file, e.g.
3198 -- Ada.Tags. If Debug_Generated_Code is true, suppress this change
3199 -- to simplify our own development.
3201 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
3202 -- If the function body is a single expression, replace call with
3203 -- expression, else insert block appropriately.
3205 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
3206 -- If procedure body has no local variables, inline body without
3207 -- creating block, otherwise rewrite call with block.
3209 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean;
3210 -- Determine whether a formal parameter is used only once in Orig_Bod
3212 -----------------------
3213 -- Is_Null_Procedure --
3214 -----------------------
3216 function Is_Null_Procedure return Boolean is
3217 Decl : constant Node_Id := Unit_Declaration_Node (Subp);
3220 if Ekind (Subp) /= E_Procedure then
3223 elsif Nkind (Orig_Bod) /= N_Subprogram_Body then
3226 -- Check if this is an Ada 2005 null procedure
3228 elsif Nkind (Decl) = N_Subprogram_Declaration
3229 and then Null_Present (Specification (Decl))
3233 -- Check if the body contains only a null statement, followed by the
3234 -- return statement added during expansion.
3238 Stat : constant Node_Id :=
3240 (Statements (Handled_Statement_Sequence (Orig_Bod)));
3242 Stat2 : constant Node_Id := Next (Stat);
3246 Nkind (Stat) = N_Null_Statement
3250 (Nkind (Stat2) = N_Simple_Return_Statement
3251 and then No (Next (Stat2))));
3254 end Is_Null_Procedure;
3256 ---------------------
3257 -- Make_Exit_Label --
3258 ---------------------
3260 procedure Make_Exit_Label is
3262 -- Create exit label for subprogram if one does not exist yet
3264 if No (Exit_Lab) then
3266 Make_Identifier (Loc,
3267 Chars => New_Internal_Name ('L'));
3269 Make_Defining_Identifier (Loc, Chars (Lab_Id)));
3270 Exit_Lab := Make_Label (Loc, Lab_Id);
3273 Make_Implicit_Label_Declaration (Loc,
3274 Defining_Identifier => Entity (Lab_Id),
3275 Label_Construct => Exit_Lab);
3277 end Make_Exit_Label;
3279 ---------------------
3280 -- Process_Formals --
3281 ---------------------
3283 function Process_Formals (N : Node_Id) return Traverse_Result is
3289 if Is_Entity_Name (N)
3290 and then Present (Entity (N))
3295 and then Scope (E) = Subp
3297 A := Renamed_Object (E);
3299 -- Rewrite the occurrence of the formal into an occurrence of
3300 -- the actual. Also establish visibility on the proper view of
3301 -- the actual's subtype for the body's context (if the actual's
3302 -- subtype is private at the call point but its full view is
3303 -- visible to the body, then the inlined tree here must be
3304 -- analyzed with the full view).
3306 if Is_Entity_Name (A) then
3307 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
3308 Check_Private_View (N);
3310 elsif Nkind (A) = N_Defining_Identifier then
3311 Rewrite (N, New_Occurrence_Of (A, Loc));
3312 Check_Private_View (N);
3317 Rewrite (N, New_Copy (A));
3323 elsif Nkind (N) = N_Simple_Return_Statement then
3324 if No (Expression (N)) then
3327 Make_Goto_Statement (Loc,
3328 Name => New_Copy (Lab_Id)));
3331 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
3332 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
3334 -- Function body is a single expression. No need for
3340 Num_Ret := Num_Ret + 1;
3344 -- Because of the presence of private types, the views of the
3345 -- expression and the context may be different, so place an
3346 -- unchecked conversion to the context type to avoid spurious
3347 -- errors, e.g. when the expression is a numeric literal and
3348 -- the context is private. If the expression is an aggregate,
3349 -- use a qualified expression, because an aggregate is not a
3350 -- legal argument of a conversion.
3352 if Nkind_In (Expression (N), N_Aggregate, N_Null) then
3354 Make_Qualified_Expression (Sloc (N),
3355 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
3356 Expression => Relocate_Node (Expression (N)));
3359 Unchecked_Convert_To
3360 (Ret_Type, Relocate_Node (Expression (N)));
3363 if Nkind (Targ) = N_Defining_Identifier then
3365 Make_Assignment_Statement (Loc,
3366 Name => New_Occurrence_Of (Targ, Loc),
3367 Expression => Ret));
3370 Make_Assignment_Statement (Loc,
3371 Name => New_Copy (Targ),
3372 Expression => Ret));
3375 Set_Assignment_OK (Name (N));
3377 if Present (Exit_Lab) then
3379 Make_Goto_Statement (Loc,
3380 Name => New_Copy (Lab_Id)));
3386 -- Remove pragma Unreferenced since it may refer to formals that
3387 -- are not visible in the inlined body, and in any case we will
3388 -- not be posting warnings on the inlined body so it is unneeded.
3390 elsif Nkind (N) = N_Pragma
3391 and then Chars (N) = Name_Unreferenced
3393 Rewrite (N, Make_Null_Statement (Sloc (N)));
3399 end Process_Formals;
3401 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
3407 function Process_Sloc (Nod : Node_Id) return Traverse_Result is
3409 if not Debug_Generated_Code then
3410 Set_Sloc (Nod, Sloc (N));
3411 Set_Comes_From_Source (Nod, False);
3417 procedure Reset_Slocs is new Traverse_Proc (Process_Sloc);
3419 ---------------------------
3420 -- Rewrite_Function_Call --
3421 ---------------------------
3423 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
3424 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
3425 Fst : constant Node_Id := First (Statements (HSS));
3428 -- Optimize simple case: function body is a single return statement,
3429 -- which has been expanded into an assignment.
3431 if Is_Empty_List (Declarations (Blk))
3432 and then Nkind (Fst) = N_Assignment_Statement
3433 and then No (Next (Fst))
3436 -- The function call may have been rewritten as the temporary
3437 -- that holds the result of the call, in which case remove the
3438 -- now useless declaration.
3440 if Nkind (N) = N_Identifier
3441 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
3443 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
3446 Rewrite (N, Expression (Fst));
3448 elsif Nkind (N) = N_Identifier
3449 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
3451 -- The block assigns the result of the call to the temporary
3453 Insert_After (Parent (Entity (N)), Blk);
3455 elsif Nkind (Parent (N)) = N_Assignment_Statement
3457 (Is_Entity_Name (Name (Parent (N)))
3459 (Nkind (Name (Parent (N))) = N_Explicit_Dereference
3460 and then Is_Entity_Name (Prefix (Name (Parent (N))))))
3462 -- Replace assignment with the block
3465 Original_Assignment : constant Node_Id := Parent (N);
3468 -- Preserve the original assignment node to keep the complete
3469 -- assignment subtree consistent enough for Analyze_Assignment
3470 -- to proceed (specifically, the original Lhs node must still
3471 -- have an assignment statement as its parent).
3473 -- We cannot rely on Original_Node to go back from the block
3474 -- node to the assignment node, because the assignment might
3475 -- already be a rewrite substitution.
3477 Discard_Node (Relocate_Node (Original_Assignment));
3478 Rewrite (Original_Assignment, Blk);
3481 elsif Nkind (Parent (N)) = N_Object_Declaration then
3482 Set_Expression (Parent (N), Empty);
3483 Insert_After (Parent (N), Blk);
3486 Insert_Before (Parent (N), Blk);
3488 end Rewrite_Function_Call;
3490 ----------------------------
3491 -- Rewrite_Procedure_Call --
3492 ----------------------------
3494 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
3495 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
3497 -- If there is a transient scope for N, this will be the scope of the
3498 -- actions for N, and the statements in Blk need to be within this
3499 -- scope. For example, they need to have visibility on the constant
3500 -- declarations created for the formals.
3502 -- If N needs no transient scope, and if there are no declarations in
3503 -- the inlined body, we can do a little optimization and insert the
3504 -- statements for the body directly after N, and rewrite N to a
3505 -- null statement, instead of rewriting N into a full-blown block
3508 if not Scope_Is_Transient
3509 and then Is_Empty_List (Declarations (Blk))
3511 Insert_List_After (N, Statements (HSS));
3512 Rewrite (N, Make_Null_Statement (Loc));
3516 end Rewrite_Procedure_Call;
3518 -------------------------
3519 -- Formal_Is_Used_Once --
3520 -------------------------
3522 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean is
3523 Use_Counter : Int := 0;
3525 function Count_Uses (N : Node_Id) return Traverse_Result;
3526 -- Traverse the tree and count the uses of the formal parameter.
3527 -- In this case, for optimization purposes, we do not need to
3528 -- continue the traversal once more than one use is encountered.
3534 function Count_Uses (N : Node_Id) return Traverse_Result is
3536 -- The original node is an identifier
3538 if Nkind (N) = N_Identifier
3539 and then Present (Entity (N))
3541 -- Original node's entity points to the one in the copied body
3543 and then Nkind (Entity (N)) = N_Identifier
3544 and then Present (Entity (Entity (N)))
3546 -- The entity of the copied node is the formal parameter
3548 and then Entity (Entity (N)) = Formal
3550 Use_Counter := Use_Counter + 1;
3552 if Use_Counter > 1 then
3554 -- Denote more than one use and abandon the traversal
3565 procedure Count_Formal_Uses is new Traverse_Proc (Count_Uses);
3567 -- Start of processing for Formal_Is_Used_Once
3570 Count_Formal_Uses (Orig_Bod);
3571 return Use_Counter = 1;
3572 end Formal_Is_Used_Once;
3574 -- Start of processing for Expand_Inlined_Call
3577 -- Check for special case of To_Address call, and if so, just do an
3578 -- unchecked conversion instead of expanding the call. Not only is this
3579 -- more efficient, but it also avoids problem with order of elaboration
3580 -- when address clauses are inlined (address expression elaborated at
3583 if Subp = RTE (RE_To_Address) then
3585 Unchecked_Convert_To
3587 Relocate_Node (First_Actual (N))));
3590 elsif Is_Null_Procedure then
3591 Rewrite (N, Make_Null_Statement (Loc));
3595 -- Check for an illegal attempt to inline a recursive procedure. If the
3596 -- subprogram has parameters this is detected when trying to supply a
3597 -- binding for parameters that already have one. For parameterless
3598 -- subprograms this must be done explicitly.
3600 if In_Open_Scopes (Subp) then
3601 Error_Msg_N ("call to recursive subprogram cannot be inlined?", N);
3602 Set_Is_Inlined (Subp, False);
3606 if Nkind (Orig_Bod) = N_Defining_Identifier
3607 or else Nkind (Orig_Bod) = N_Defining_Operator_Symbol
3609 -- Subprogram is a renaming_as_body. Calls appearing after the
3610 -- renaming can be replaced with calls to the renamed entity
3611 -- directly, because the subprograms are subtype conformant. If
3612 -- the renamed subprogram is an inherited operation, we must redo
3613 -- the expansion because implicit conversions may be needed.
3615 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
3617 if Present (Alias (Orig_Bod)) then
3624 -- Use generic machinery to copy body of inlined subprogram, as if it
3625 -- were an instantiation, resetting source locations appropriately, so
3626 -- that nested inlined calls appear in the main unit.
3628 Save_Env (Subp, Empty);
3629 Set_Copied_Sloc_For_Inlined_Body (N, Defining_Entity (Orig_Bod));
3631 Bod := Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
3633 Make_Block_Statement (Loc,
3634 Declarations => Declarations (Bod),
3635 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
3637 if No (Declarations (Bod)) then
3638 Set_Declarations (Blk, New_List);
3641 -- For the unconstrained case, capture the name of the local
3642 -- variable that holds the result. This must be the first declaration
3643 -- in the block, because its bounds cannot depend on local variables.
3644 -- Otherwise there is no way to declare the result outside of the
3645 -- block. Needless to say, in general the bounds will depend on the
3646 -- actuals in the call.
3649 Targ1 := Defining_Identifier (First (Declarations (Blk)));
3652 -- If this is a derived function, establish the proper return type
3654 if Present (Orig_Subp)
3655 and then Orig_Subp /= Subp
3657 Ret_Type := Etype (Orig_Subp);
3659 Ret_Type := Etype (Subp);
3662 -- Create temporaries for the actuals that are expressions, or that
3663 -- are scalars and require copying to preserve semantics.
3665 F := First_Formal (Subp);
3666 A := First_Actual (N);
3667 while Present (F) loop
3668 if Present (Renamed_Object (F)) then
3669 Error_Msg_N ("cannot inline call to recursive subprogram", N);
3673 -- If the argument may be a controlling argument in a call within
3674 -- the inlined body, we must preserve its classwide nature to insure
3675 -- that dynamic dispatching take place subsequently. If the formal
3676 -- has a constraint it must be preserved to retain the semantics of
3679 if Is_Class_Wide_Type (Etype (F))
3680 or else (Is_Access_Type (Etype (F))
3682 Is_Class_Wide_Type (Designated_Type (Etype (F))))
3684 Temp_Typ := Etype (F);
3686 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
3687 and then Etype (F) /= Base_Type (Etype (F))
3689 Temp_Typ := Etype (F);
3692 Temp_Typ := Etype (A);
3695 -- If the actual is a simple name or a literal, no need to
3696 -- create a temporary, object can be used directly.
3698 -- If the actual is a literal and the formal has its address taken,
3699 -- we cannot pass the literal itself as an argument, so its value
3700 -- must be captured in a temporary.
3702 if (Is_Entity_Name (A)
3704 (not Is_Scalar_Type (Etype (A))
3705 or else Ekind (Entity (A)) = E_Enumeration_Literal))
3707 -- When the actual is an identifier and the corresponding formal
3708 -- is used only once in the original body, the formal can be
3709 -- substituted directly with the actual parameter.
3711 or else (Nkind (A) = N_Identifier
3712 and then Formal_Is_Used_Once (F))
3715 (Nkind_In (A, N_Real_Literal,
3717 N_Character_Literal)
3718 and then not Address_Taken (F))
3720 if Etype (F) /= Etype (A) then
3722 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
3724 Set_Renamed_Object (F, A);
3729 Make_Defining_Identifier (Loc,
3730 Chars => New_Internal_Name ('C'));
3732 -- If the actual for an in/in-out parameter is a view conversion,
3733 -- make it into an unchecked conversion, given that an untagged
3734 -- type conversion is not a proper object for a renaming.
3736 -- In-out conversions that involve real conversions have already
3737 -- been transformed in Expand_Actuals.
3739 if Nkind (A) = N_Type_Conversion
3740 and then Ekind (F) /= E_In_Parameter
3743 Make_Unchecked_Type_Conversion (Loc,
3744 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
3745 Expression => Relocate_Node (Expression (A)));
3747 elsif Etype (F) /= Etype (A) then
3748 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
3749 Temp_Typ := Etype (F);
3752 New_A := Relocate_Node (A);
3755 Set_Sloc (New_A, Sloc (N));
3757 -- If the actual has a by-reference type, it cannot be copied, so
3758 -- its value is captured in a renaming declaration. Otherwise
3759 -- declare a local constant initialized with the actual.
3761 if Ekind (F) = E_In_Parameter
3762 and then not Is_Limited_Type (Etype (A))
3763 and then not Is_Tagged_Type (Etype (A))
3766 Make_Object_Declaration (Loc,
3767 Defining_Identifier => Temp,
3768 Constant_Present => True,
3769 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
3770 Expression => New_A);
3773 Make_Object_Renaming_Declaration (Loc,
3774 Defining_Identifier => Temp,
3775 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
3779 Append (Decl, Decls);
3780 Set_Renamed_Object (F, Temp);
3787 -- Establish target of function call. If context is not assignment or
3788 -- declaration, create a temporary as a target. The declaration for
3789 -- the temporary may be subsequently optimized away if the body is a
3790 -- single expression, or if the left-hand side of the assignment is
3791 -- simple enough, i.e. an entity or an explicit dereference of one.
3793 if Ekind (Subp) = E_Function then
3794 if Nkind (Parent (N)) = N_Assignment_Statement
3795 and then Is_Entity_Name (Name (Parent (N)))
3797 Targ := Name (Parent (N));
3799 elsif Nkind (Parent (N)) = N_Assignment_Statement
3800 and then Nkind (Name (Parent (N))) = N_Explicit_Dereference
3801 and then Is_Entity_Name (Prefix (Name (Parent (N))))
3803 Targ := Name (Parent (N));
3806 -- Replace call with temporary and create its declaration
3809 Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
3810 Set_Is_Internal (Temp);
3812 -- For the unconstrained case. the generated temporary has the
3813 -- same constrained declaration as the result variable.
3814 -- It may eventually be possible to remove that temporary and
3815 -- use the result variable directly.
3819 Make_Object_Declaration (Loc,
3820 Defining_Identifier => Temp,
3821 Object_Definition =>
3822 New_Copy_Tree (Object_Definition (Parent (Targ1))));
3824 Replace_Formals (Decl);
3828 Make_Object_Declaration (Loc,
3829 Defining_Identifier => Temp,
3830 Object_Definition =>
3831 New_Occurrence_Of (Ret_Type, Loc));
3833 Set_Etype (Temp, Ret_Type);
3836 Set_No_Initialization (Decl);
3837 Append (Decl, Decls);
3838 Rewrite (N, New_Occurrence_Of (Temp, Loc));
3843 Insert_Actions (N, Decls);
3845 -- Traverse the tree and replace formals with actuals or their thunks.
3846 -- Attach block to tree before analysis and rewriting.
3848 Replace_Formals (Blk);
3849 Set_Parent (Blk, N);
3851 if not Comes_From_Source (Subp)
3857 if Present (Exit_Lab) then
3859 -- If the body was a single expression, the single return statement
3860 -- and the corresponding label are useless.
3864 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
3867 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
3869 Append (Lab_Decl, (Declarations (Blk)));
3870 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
3874 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
3875 -- conflicting private views that Gigi would ignore. If this is
3876 -- predefined unit, analyze with checks off, as is done in the non-
3877 -- inlined run-time units.
3880 I_Flag : constant Boolean := In_Inlined_Body;
3883 In_Inlined_Body := True;
3887 Style : constant Boolean := Style_Check;
3889 Style_Check := False;
3890 Analyze (Blk, Suppress => All_Checks);
3891 Style_Check := Style;
3898 In_Inlined_Body := I_Flag;
3901 if Ekind (Subp) = E_Procedure then
3902 Rewrite_Procedure_Call (N, Blk);
3904 Rewrite_Function_Call (N, Blk);
3906 -- For the unconstrained case, the replacement of the call has been
3907 -- made prior to the complete analysis of the generated declarations.
3908 -- Propagate the proper type now.
3911 if Nkind (N) = N_Identifier then
3912 Set_Etype (N, Etype (Entity (N)));
3914 Set_Etype (N, Etype (Targ1));
3921 -- Cleanup mapping between formals and actuals for other expansions
3923 F := First_Formal (Subp);
3924 while Present (F) loop
3925 Set_Renamed_Object (F, Empty);
3928 end Expand_Inlined_Call;
3930 ----------------------------
3931 -- Expand_N_Function_Call --
3932 ----------------------------
3934 procedure Expand_N_Function_Call (N : Node_Id) is
3937 end Expand_N_Function_Call;
3939 ---------------------------------------
3940 -- Expand_N_Procedure_Call_Statement --
3941 ---------------------------------------
3943 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
3946 end Expand_N_Procedure_Call_Statement;
3948 ------------------------------
3949 -- Expand_N_Subprogram_Body --
3950 ------------------------------
3952 -- Add poll call if ATC polling is enabled, unless the body will be
3953 -- inlined by the back-end.
3955 -- Add dummy push/pop label nodes at start and end to clear any local
3956 -- exception indications if local-exception-to-goto optimization active.
3958 -- Add return statement if last statement in body is not a return statement
3959 -- (this makes things easier on Gigi which does not want to have to handle
3960 -- a missing return).
3962 -- Add call to Activate_Tasks if body is a task activator
3964 -- Deal with possible detection of infinite recursion
3966 -- Eliminate body completely if convention stubbed
3968 -- Encode entity names within body, since we will not need to reference
3969 -- these entities any longer in the front end.
3971 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
3973 -- Reset Pure indication if any parameter has root type System.Address
3977 procedure Expand_N_Subprogram_Body (N : Node_Id) is
3978 Loc : constant Source_Ptr := Sloc (N);
3979 H : constant Node_Id := Handled_Statement_Sequence (N);
3980 Body_Id : Entity_Id;
3981 Spec_Id : Entity_Id;
3988 procedure Add_Return (S : List_Id);
3989 -- Append a return statement to the statement sequence S if the last
3990 -- statement is not already a return or a goto statement. Note that
3991 -- the latter test is not critical, it does not matter if we add a
3992 -- few extra returns, since they get eliminated anyway later on.
3998 procedure Add_Return (S : List_Id) is
4003 -- Get last statement, ignoring any Pop_xxx_Label nodes, which are
4004 -- not relevant in this context since they are not executable.
4006 Last_Stm := Last (S);
4007 while Nkind (Last_Stm) in N_Pop_xxx_Label loop
4011 -- Now insert return unless last statement is a transfer
4013 if not Is_Transfer (Last_Stm) then
4015 -- The source location for the return is the end label of the
4016 -- procedure if present. Otherwise use the sloc of the last
4017 -- statement in the list. If the list comes from a generated
4018 -- exception handler and we are not debugging generated code,
4019 -- all the statements within the handler are made invisible
4022 if Nkind (Parent (S)) = N_Exception_Handler
4023 and then not Comes_From_Source (Parent (S))
4025 Loc := Sloc (Last_Stm);
4027 elsif Present (End_Label (H)) then
4028 Loc := Sloc (End_Label (H));
4031 Loc := Sloc (Last_Stm);
4034 Append_To (S, Make_Simple_Return_Statement (Loc));
4038 -- Start of processing for Expand_N_Subprogram_Body
4041 -- Set L to either the list of declarations if present, or
4042 -- to the list of statements if no declarations are present.
4043 -- This is used to insert new stuff at the start.
4045 if Is_Non_Empty_List (Declarations (N)) then
4046 L := Declarations (N);
4048 L := Statements (H);
4051 -- If local-exception-to-goto optimization active, insert dummy push
4052 -- statements at start, and dummy pop statements at end.
4054 if (Debug_Flag_Dot_G
4055 or else Restriction_Active (No_Exception_Propagation))
4056 and then Is_Non_Empty_List (L)
4059 FS : constant Node_Id := First (L);
4060 FL : constant Source_Ptr := Sloc (FS);
4065 -- LS points to either last statement, if statements are present
4066 -- or to the last declaration if there are no statements present.
4067 -- It is the node after which the pop's are generated.
4069 if Is_Non_Empty_List (Statements (H)) then
4070 LS := Last (Statements (H));
4077 Insert_List_Before_And_Analyze (FS, New_List (
4078 Make_Push_Constraint_Error_Label (FL),
4079 Make_Push_Program_Error_Label (FL),
4080 Make_Push_Storage_Error_Label (FL)));
4082 Insert_List_After_And_Analyze (LS, New_List (
4083 Make_Pop_Constraint_Error_Label (LL),
4084 Make_Pop_Program_Error_Label (LL),
4085 Make_Pop_Storage_Error_Label (LL)));
4089 -- Find entity for subprogram
4091 Body_Id := Defining_Entity (N);
4093 if Present (Corresponding_Spec (N)) then
4094 Spec_Id := Corresponding_Spec (N);
4099 -- Need poll on entry to subprogram if polling enabled. We only do this
4100 -- for non-empty subprograms, since it does not seem necessary to poll
4101 -- for a dummy null subprogram. Do not add polling point if calls to
4102 -- this subprogram will be inlined by the back-end, to avoid repeated
4103 -- polling points in nested inlinings.
4105 if Is_Non_Empty_List (L) then
4106 if Is_Inlined (Spec_Id)
4107 and then Front_End_Inlining
4108 and then Optimization_Level > 1
4112 Generate_Poll_Call (First (L));
4116 -- If this is a Pure function which has any parameters whose root
4117 -- type is System.Address, reset the Pure indication, since it will
4118 -- likely cause incorrect code to be generated as the parameter is
4119 -- probably a pointer, and the fact that the same pointer is passed
4120 -- does not mean that the same value is being referenced.
4122 -- Note that if the programmer gave an explicit Pure_Function pragma,
4123 -- then we believe the programmer, and leave the subprogram Pure.
4125 -- This code should probably be at the freeze point, so that it
4126 -- happens even on a -gnatc (or more importantly -gnatt) compile
4127 -- so that the semantic tree has Is_Pure set properly ???
4129 if Is_Pure (Spec_Id)
4130 and then Is_Subprogram (Spec_Id)
4131 and then not Has_Pragma_Pure_Function (Spec_Id)
4137 F := First_Formal (Spec_Id);
4138 while Present (F) loop
4139 if Is_Descendent_Of_Address (Etype (F)) then
4140 Set_Is_Pure (Spec_Id, False);
4142 if Spec_Id /= Body_Id then
4143 Set_Is_Pure (Body_Id, False);
4154 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
4156 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
4161 -- Loop through formals
4163 F := First_Formal (Spec_Id);
4164 while Present (F) loop
4165 if Is_Scalar_Type (Etype (F))
4166 and then Ekind (F) = E_Out_Parameter
4168 -- Insert the initialization. We turn off validity checks
4169 -- for this assignment, since we do not want any check on
4170 -- the initial value itself (which may well be invalid).
4172 Insert_Before_And_Analyze (First (L),
4173 Make_Assignment_Statement (Loc,
4174 Name => New_Occurrence_Of (F, Loc),
4175 Expression => Get_Simple_Init_Val (Etype (F), Loc)),
4176 Suppress => Validity_Check);
4184 Scop := Scope (Spec_Id);
4186 -- Add discriminal renamings to protected subprograms. Install new
4187 -- discriminals for expansion of the next subprogram of this protected
4190 if Is_List_Member (N)
4191 and then Present (Parent (List_Containing (N)))
4192 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
4194 Add_Discriminal_Declarations
4195 (Declarations (N), Scop, Name_uObject, Loc);
4196 Add_Private_Declarations
4197 (Declarations (N), Scop, Name_uObject, Loc);
4199 -- Associate privals and discriminals with the next protected
4200 -- operation body to be expanded. These are used to expand references
4201 -- to private data objects and discriminants, respectively.
4203 Next_Op := Next_Protected_Operation (N);
4205 if Present (Next_Op) then
4206 Dec := Parent (Base_Type (Scop));
4207 Set_Privals (Dec, Next_Op, Loc);
4208 Set_Discriminals (Dec);
4212 -- Clear out statement list for stubbed procedure
4214 if Present (Corresponding_Spec (N)) then
4215 Set_Elaboration_Flag (N, Spec_Id);
4217 if Convention (Spec_Id) = Convention_Stubbed
4218 or else Is_Eliminated (Spec_Id)
4220 Set_Declarations (N, Empty_List);
4221 Set_Handled_Statement_Sequence (N,
4222 Make_Handled_Sequence_Of_Statements (Loc,
4223 Statements => New_List (
4224 Make_Null_Statement (Loc))));
4229 -- Returns_By_Ref flag is normally set when the subprogram is frozen
4230 -- but subprograms with no specs are not frozen.
4233 Typ : constant Entity_Id := Etype (Spec_Id);
4234 Utyp : constant Entity_Id := Underlying_Type (Typ);
4237 if not Acts_As_Spec (N)
4238 and then Nkind (Parent (Parent (Spec_Id))) /=
4239 N_Subprogram_Body_Stub
4243 elsif Is_Inherently_Limited_Type (Typ) then
4244 Set_Returns_By_Ref (Spec_Id);
4246 elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
4247 Set_Returns_By_Ref (Spec_Id);
4251 -- For a procedure, we add a return for all possible syntactic ends
4252 -- of the subprogram. Note that reanalysis is not necessary in this
4253 -- case since it would require a lot of work and accomplish nothing.
4255 if Ekind (Spec_Id) = E_Procedure
4256 or else Ekind (Spec_Id) = E_Generic_Procedure
4258 Add_Return (Statements (H));
4260 if Present (Exception_Handlers (H)) then
4261 Except_H := First_Non_Pragma (Exception_Handlers (H));
4262 while Present (Except_H) loop
4263 Add_Return (Statements (Except_H));
4264 Next_Non_Pragma (Except_H);
4268 -- For a function, we must deal with the case where there is at least
4269 -- one missing return. What we do is to wrap the entire body of the
4270 -- function in a block:
4283 -- raise Program_Error;
4286 -- This approach is necessary because the raise must be signalled
4287 -- to the caller, not handled by any local handler (RM 6.4(11)).
4289 -- Note: we do not need to analyze the constructed sequence here,
4290 -- since it has no handler, and an attempt to analyze the handled
4291 -- statement sequence twice is risky in various ways (e.g. the
4292 -- issue of expanding cleanup actions twice).
4294 elsif Has_Missing_Return (Spec_Id) then
4296 Hloc : constant Source_Ptr := Sloc (H);
4297 Blok : constant Node_Id :=
4298 Make_Block_Statement (Hloc,
4299 Handled_Statement_Sequence => H);
4300 Rais : constant Node_Id :=
4301 Make_Raise_Program_Error (Hloc,
4302 Reason => PE_Missing_Return);
4305 Set_Handled_Statement_Sequence (N,
4306 Make_Handled_Sequence_Of_Statements (Hloc,
4307 Statements => New_List (Blok, Rais)));
4309 Push_Scope (Spec_Id);
4316 -- If subprogram contains a parameterless recursive call, then we may
4317 -- have an infinite recursion, so see if we can generate code to check
4318 -- for this possibility if storage checks are not suppressed.
4320 if Ekind (Spec_Id) = E_Procedure
4321 and then Has_Recursive_Call (Spec_Id)
4322 and then not Storage_Checks_Suppressed (Spec_Id)
4324 Detect_Infinite_Recursion (N, Spec_Id);
4327 -- Finally, if we are in Normalize_Scalars mode, then any scalar out
4328 -- parameters must be initialized to the appropriate default value.
4330 if Ekind (Spec_Id) = E_Procedure and then Normalize_Scalars then
4337 Formal := First_Formal (Spec_Id);
4338 while Present (Formal) loop
4339 Floc := Sloc (Formal);
4341 if Ekind (Formal) = E_Out_Parameter
4342 and then Is_Scalar_Type (Etype (Formal))
4345 Make_Assignment_Statement (Floc,
4346 Name => New_Occurrence_Of (Formal, Floc),
4348 Get_Simple_Init_Val (Etype (Formal), Floc));
4349 Prepend (Stm, Declarations (N));
4353 Next_Formal (Formal);
4358 -- Set to encode entity names in package body before gigi is called
4360 Qualify_Entity_Names (N);
4361 end Expand_N_Subprogram_Body;
4363 -----------------------------------
4364 -- Expand_N_Subprogram_Body_Stub --
4365 -----------------------------------
4367 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
4369 if Present (Corresponding_Body (N)) then
4370 Expand_N_Subprogram_Body (
4371 Unit_Declaration_Node (Corresponding_Body (N)));
4373 end Expand_N_Subprogram_Body_Stub;
4375 -------------------------------------
4376 -- Expand_N_Subprogram_Declaration --
4377 -------------------------------------
4379 -- If the declaration appears within a protected body, it is a private
4380 -- operation of the protected type. We must create the corresponding
4381 -- protected subprogram an associated formals. For a normal protected
4382 -- operation, this is done when expanding the protected type declaration.
4384 -- If the declaration is for a null procedure, emit null body
4386 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
4387 Loc : constant Source_Ptr := Sloc (N);
4388 Subp : constant Entity_Id := Defining_Entity (N);
4389 Scop : constant Entity_Id := Scope (Subp);
4390 Prot_Decl : Node_Id;
4392 Prot_Id : Entity_Id;
4395 -- Deal with case of protected subprogram. Do not generate protected
4396 -- operation if operation is flagged as eliminated.
4398 if Is_List_Member (N)
4399 and then Present (Parent (List_Containing (N)))
4400 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
4401 and then Is_Protected_Type (Scop)
4403 if No (Protected_Body_Subprogram (Subp))
4404 and then not Is_Eliminated (Subp)
4407 Make_Subprogram_Declaration (Loc,
4409 Build_Protected_Sub_Specification
4410 (N, Scop, Unprotected_Mode));
4412 -- The protected subprogram is declared outside of the protected
4413 -- body. Given that the body has frozen all entities so far, we
4414 -- analyze the subprogram and perform freezing actions explicitly.
4415 -- including the generation of an explicit freeze node, to ensure
4416 -- that gigi has the proper order of elaboration.
4417 -- If the body is a subunit, the insertion point is before the
4418 -- stub in the parent.
4420 Prot_Bod := Parent (List_Containing (N));
4422 if Nkind (Parent (Prot_Bod)) = N_Subunit then
4423 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
4426 Insert_Before (Prot_Bod, Prot_Decl);
4427 Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
4428 Set_Has_Delayed_Freeze (Prot_Id);
4430 Push_Scope (Scope (Scop));
4431 Analyze (Prot_Decl);
4432 Insert_Actions (N, Freeze_Entity (Prot_Id, Loc));
4433 Set_Protected_Body_Subprogram (Subp, Prot_Id);
4437 -- Ada 2005 (AI-348): Generation of the null body
4439 elsif Nkind (Specification (N)) = N_Procedure_Specification
4440 and then Null_Present (Specification (N))
4443 Bod : constant Node_Id :=
4444 Make_Subprogram_Body (Loc,
4446 New_Copy_Tree (Specification (N)),
4447 Declarations => New_List,
4448 Handled_Statement_Sequence =>
4449 Make_Handled_Sequence_Of_Statements (Loc,
4450 Statements => New_List (Make_Null_Statement (Loc))));
4452 Set_Body_To_Inline (N, Bod);
4453 Insert_After (N, Bod);
4456 -- Corresponding_Spec isn't being set by Analyze_Subprogram_Body,
4457 -- evidently because Set_Has_Completion is called earlier for null
4458 -- procedures in Analyze_Subprogram_Declaration, so we force its
4459 -- setting here. If the setting of Has_Completion is not set
4460 -- earlier, then it can result in missing body errors if other
4461 -- errors were already reported (since expansion is turned off).
4463 -- Should creation of the empty body be moved to the analyzer???
4465 Set_Corresponding_Spec (Bod, Defining_Entity (Specification (N)));
4468 end Expand_N_Subprogram_Declaration;
4470 ---------------------------------------
4471 -- Expand_Protected_Object_Reference --
4472 ---------------------------------------
4474 function Expand_Protected_Object_Reference
4476 Scop : Entity_Id) return Node_Id
4478 Loc : constant Source_Ptr := Sloc (N);
4486 Make_Identifier (Loc,
4487 Chars => Name_uObject);
4488 Set_Etype (Rec, Corresponding_Record_Type (Scop));
4490 -- Find enclosing protected operation, and retrieve its first parameter,
4491 -- which denotes the enclosing protected object. If the enclosing
4492 -- operation is an entry, we are immediately within the protected body,
4493 -- and we can retrieve the object from the service entries procedure. A
4494 -- barrier function has has the same signature as an entry. A barrier
4495 -- function is compiled within the protected object, but unlike
4496 -- protected operations its never needs locks, so that its protected
4497 -- body subprogram points to itself.
4499 Proc := Current_Scope;
4500 while Present (Proc)
4501 and then Scope (Proc) /= Scop
4503 Proc := Scope (Proc);
4506 Corr := Protected_Body_Subprogram (Proc);
4510 -- Previous error left expansion incomplete.
4511 -- Nothing to do on this call.
4518 (First (Parameter_Specifications (Parent (Corr))));
4520 if Is_Subprogram (Proc)
4521 and then Proc /= Corr
4523 -- Protected function or procedure
4525 Set_Entity (Rec, Param);
4527 -- Rec is a reference to an entity which will not be in scope when
4528 -- the call is reanalyzed, and needs no further analysis.
4533 -- Entry or barrier function for entry body. The first parameter of
4534 -- the entry body procedure is pointer to the object. We create a
4535 -- local variable of the proper type, duplicating what is done to
4536 -- define _object later on.
4540 Obj_Ptr : constant Entity_Id := Make_Defining_Identifier (Loc,
4542 New_Internal_Name ('T'));
4546 Make_Full_Type_Declaration (Loc,
4547 Defining_Identifier => Obj_Ptr,
4549 Make_Access_To_Object_Definition (Loc,
4550 Subtype_Indication =>
4552 (Corresponding_Record_Type (Scop), Loc))));
4554 Insert_Actions (N, Decls);
4555 Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
4558 Make_Explicit_Dereference (Loc,
4559 Unchecked_Convert_To (Obj_Ptr,
4560 New_Occurrence_Of (Param, Loc)));
4562 -- Analyze new actual. Other actuals in calls are already analyzed
4563 -- and the list of actuals is not reanalyzed after rewriting.
4565 Set_Parent (Rec, N);
4571 end Expand_Protected_Object_Reference;
4573 --------------------------------------
4574 -- Expand_Protected_Subprogram_Call --
4575 --------------------------------------
4577 procedure Expand_Protected_Subprogram_Call
4585 -- If the protected object is not an enclosing scope, this is
4586 -- an inter-object function call. Inter-object procedure
4587 -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
4588 -- The call is intra-object only if the subprogram being
4589 -- called is in the protected body being compiled, and if the
4590 -- protected object in the call is statically the enclosing type.
4591 -- The object may be an component of some other data structure,
4592 -- in which case this must be handled as an inter-object call.
4594 if not In_Open_Scopes (Scop)
4595 or else not Is_Entity_Name (Name (N))
4597 if Nkind (Name (N)) = N_Selected_Component then
4598 Rec := Prefix (Name (N));
4601 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
4602 Rec := Prefix (Prefix (Name (N)));
4605 Build_Protected_Subprogram_Call (N,
4606 Name => New_Occurrence_Of (Subp, Sloc (N)),
4607 Rec => Convert_Concurrent (Rec, Etype (Rec)),
4611 Rec := Expand_Protected_Object_Reference (N, Scop);
4617 Build_Protected_Subprogram_Call (N,
4626 -- If it is a function call it can appear in elaboration code and
4627 -- the called entity must be frozen here.
4629 if Ekind (Subp) = E_Function then
4630 Freeze_Expression (Name (N));
4632 end Expand_Protected_Subprogram_Call;
4634 --------------------------------
4635 -- Is_Build_In_Place_Function --
4636 --------------------------------
4638 function Is_Build_In_Place_Function (E : Entity_Id) return Boolean is
4640 -- For now we test whether E denotes a function or access-to-function
4641 -- type whose result subtype is inherently limited. Later this test may
4642 -- be revised to allow composite nonlimited types. Functions with a
4643 -- foreign convention or whose result type has a foreign convention
4646 if Ekind (E) = E_Function
4647 or else Ekind (E) = E_Generic_Function
4648 or else (Ekind (E) = E_Subprogram_Type
4649 and then Etype (E) /= Standard_Void_Type)
4651 -- Note: If you have Convention (C) on an inherently limited type,
4652 -- you're on your own. That is, the C code will have to be carefully
4653 -- written to know about the Ada conventions.
4655 if Has_Foreign_Convention (E)
4656 or else Has_Foreign_Convention (Etype (E))
4660 -- If the return type is a limited interface it has to be treated
4661 -- as a return in place, even if the actual object is some non-
4662 -- limited descendant.
4664 elsif Is_Limited_Interface (Etype (E)) then
4668 return Is_Inherently_Limited_Type (Etype (E))
4669 and then Ada_Version >= Ada_05
4670 and then not Debug_Flag_Dot_L;
4676 end Is_Build_In_Place_Function;
4678 -------------------------------------
4679 -- Is_Build_In_Place_Function_Call --
4680 -------------------------------------
4682 function Is_Build_In_Place_Function_Call (N : Node_Id) return Boolean is
4683 Exp_Node : Node_Id := N;
4684 Function_Id : Entity_Id;
4687 -- Step past qualification or unchecked conversion (the latter can occur
4688 -- in cases of calls to 'Input).
4691 (Exp_Node, N_Qualified_Expression, N_Unchecked_Type_Conversion)
4693 Exp_Node := Expression (N);
4696 if Nkind (Exp_Node) /= N_Function_Call then
4700 if Is_Entity_Name (Name (Exp_Node)) then
4701 Function_Id := Entity (Name (Exp_Node));
4703 elsif Nkind (Name (Exp_Node)) = N_Explicit_Dereference then
4704 Function_Id := Etype (Name (Exp_Node));
4707 return Is_Build_In_Place_Function (Function_Id);
4709 end Is_Build_In_Place_Function_Call;
4711 ---------------------------------------
4712 -- Is_Build_In_Place_Function_Return --
4713 ---------------------------------------
4715 function Is_Build_In_Place_Function_Return (N : Node_Id) return Boolean is
4717 if Nkind_In (N, N_Simple_Return_Statement,
4718 N_Extended_Return_Statement)
4720 return Is_Build_In_Place_Function
4721 (Return_Applies_To (Return_Statement_Entity (N)));
4725 end Is_Build_In_Place_Function_Return;
4727 -----------------------
4728 -- Freeze_Subprogram --
4729 -----------------------
4731 procedure Freeze_Subprogram (N : Node_Id) is
4732 Loc : constant Source_Ptr := Sloc (N);
4734 procedure Register_Predefined_DT_Entry (Prim : Entity_Id);
4735 -- (Ada 2005): Register a predefined primitive in all the secondary
4736 -- dispatch tables of its primitive type.
4738 ----------------------------------
4739 -- Register_Predefined_DT_Entry --
4740 ----------------------------------
4742 procedure Register_Predefined_DT_Entry (Prim : Entity_Id) is
4743 Iface_DT_Ptr : Elmt_Id;
4744 Tagged_Typ : Entity_Id;
4745 Thunk_Id : Entity_Id;
4746 Thunk_Code : Node_Id;
4749 Tagged_Typ := Find_Dispatching_Type (Prim);
4751 if No (Access_Disp_Table (Tagged_Typ))
4752 or else not Has_Abstract_Interfaces (Tagged_Typ)
4753 or else not RTE_Available (RE_Interface_Tag)
4754 or else Restriction_Active (No_Dispatching_Calls)
4759 -- Skip the first access-to-dispatch-table pointer since it leads
4760 -- to the primary dispatch table. We are only concerned with the
4761 -- secondary dispatch table pointers. Note that the access-to-
4762 -- dispatch-table pointer corresponds to the first implemented
4763 -- interface retrieved below.
4766 Next_Elmt (First_Elmt (Access_Disp_Table (Tagged_Typ)));
4768 while Present (Iface_DT_Ptr)
4769 and then Ekind (Node (Iface_DT_Ptr)) = E_Constant
4771 pragma Assert (Has_Thunks (Node (Iface_DT_Ptr)));
4772 Expand_Interface_Thunk (Prim, Thunk_Id, Thunk_Code);
4774 if Present (Thunk_Code) then
4775 Insert_Actions_After (N, New_List (
4778 Build_Set_Predefined_Prim_Op_Address (Loc,
4779 Tag_Node => New_Reference_To (Node (Iface_DT_Ptr), Loc),
4780 Position => DT_Position (Prim),
4782 Make_Attribute_Reference (Loc,
4783 Prefix => New_Reference_To (Thunk_Id, Loc),
4784 Attribute_Name => Name_Address)),
4786 Build_Set_Predefined_Prim_Op_Address (Loc,
4787 Tag_Node => New_Reference_To
4788 (Node (Next_Elmt (Iface_DT_Ptr)), Loc),
4789 Position => DT_Position (Prim),
4791 Make_Attribute_Reference (Loc,
4792 Prefix => New_Reference_To (Prim, Loc),
4793 Attribute_Name => Name_Address))));
4796 Next_Elmt (Iface_DT_Ptr);
4797 pragma Assert (not Has_Thunks (Node (Iface_DT_Ptr)));
4799 Next_Elmt (Iface_DT_Ptr);
4801 end Register_Predefined_DT_Entry;
4805 Subp : constant Entity_Id := Entity (N);
4807 -- Start of processing for Freeze_Subprogram
4810 -- We suppress the initialization of the dispatch table entry when
4811 -- VM_Target because the dispatching mechanism is handled internally
4814 if Is_Dispatching_Operation (Subp)
4815 and then not Is_Abstract_Subprogram (Subp)
4816 and then Present (DTC_Entity (Subp))
4817 and then Present (Scope (DTC_Entity (Subp)))
4818 and then VM_Target = No_VM
4819 and then not Restriction_Active (No_Dispatching_Calls)
4820 and then RTE_Available (RE_Tag)
4823 Typ : constant Entity_Id := Scope (DTC_Entity (Subp));
4826 -- Handle private overridden primitives
4828 if not Is_CPP_Class (Typ) then
4829 Check_Overriding_Operation (Subp);
4832 -- We assume that imported CPP primitives correspond with objects
4833 -- whose constructor is in the CPP side; therefore we don't need
4834 -- to generate code to register them in the dispatch table.
4836 if Is_CPP_Class (Typ) then
4839 -- Handle CPP primitives found in derivations of CPP_Class types.
4840 -- These primitives must have been inherited from some parent, and
4841 -- there is no need to register them in the dispatch table because
4842 -- Build_Inherit_Prims takes care of the initialization of these
4845 elsif Is_Imported (Subp)
4846 and then (Convention (Subp) = Convention_CPP
4847 or else Convention (Subp) = Convention_C)
4851 -- Generate code to register the primitive in non statically
4852 -- allocated dispatch tables
4854 elsif not Static_Dispatch_Tables
4856 Is_Library_Level_Tagged_Type (Scope (DTC_Entity (Subp)))
4858 -- When a primitive is frozen, enter its name in its dispatch
4861 if not Is_Interface (Typ)
4862 or else Present (Abstract_Interface_Alias (Subp))
4864 if Is_Predefined_Dispatching_Operation (Subp) then
4865 Register_Predefined_DT_Entry (Subp);
4868 Register_Primitive (Loc,
4876 -- Mark functions that return by reference. Note that it cannot be part
4877 -- of the normal semantic analysis of the spec since the underlying
4878 -- returned type may not be known yet (for private types).
4881 Typ : constant Entity_Id := Etype (Subp);
4882 Utyp : constant Entity_Id := Underlying_Type (Typ);
4884 if Is_Inherently_Limited_Type (Typ) then
4885 Set_Returns_By_Ref (Subp);
4886 elsif Present (Utyp) and then CW_Or_Controlled_Type (Utyp) then
4887 Set_Returns_By_Ref (Subp);
4890 end Freeze_Subprogram;
4892 -------------------------------------------
4893 -- Make_Build_In_Place_Call_In_Allocator --
4894 -------------------------------------------
4896 procedure Make_Build_In_Place_Call_In_Allocator
4897 (Allocator : Node_Id;
4898 Function_Call : Node_Id)
4901 Func_Call : Node_Id := Function_Call;
4902 Function_Id : Entity_Id;
4903 Result_Subt : Entity_Id;
4904 Acc_Type : constant Entity_Id := Etype (Allocator);
4905 New_Allocator : Node_Id;
4906 Return_Obj_Access : Entity_Id;
4909 -- Step past qualification or unchecked conversion (the latter can occur
4910 -- in cases of calls to 'Input).
4912 if Nkind_In (Func_Call,
4913 N_Qualified_Expression,
4914 N_Unchecked_Type_Conversion)
4916 Func_Call := Expression (Func_Call);
4919 -- If the call has already been processed to add build-in-place actuals
4920 -- then return. This should not normally occur in an allocator context,
4921 -- but we add the protection as a defensive measure.
4923 if Is_Expanded_Build_In_Place_Call (Func_Call) then
4927 -- Mark the call as processed as a build-in-place call
4929 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
4931 Loc := Sloc (Function_Call);
4933 if Is_Entity_Name (Name (Func_Call)) then
4934 Function_Id := Entity (Name (Func_Call));
4936 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
4937 Function_Id := Etype (Name (Func_Call));
4940 raise Program_Error;
4943 Result_Subt := Etype (Function_Id);
4945 -- When the result subtype is constrained, the return object must be
4946 -- allocated on the caller side, and access to it is passed to the
4949 -- Here and in related routines, we must examine the full view of the
4950 -- type, because the view at the point of call may differ from that
4951 -- that in the function body, and the expansion mechanism depends on
4952 -- the characteristics of the full view.
4954 if Is_Constrained (Underlying_Type (Result_Subt)) then
4956 -- Replace the initialized allocator of form "new T'(Func (...))"
4957 -- with an uninitialized allocator of form "new T", where T is the
4958 -- result subtype of the called function. The call to the function
4959 -- is handled separately further below.
4962 Make_Allocator (Loc, New_Reference_To (Result_Subt, Loc));
4964 Set_Storage_Pool (New_Allocator, Storage_Pool (Allocator));
4965 Set_Procedure_To_Call (New_Allocator, Procedure_To_Call (Allocator));
4966 Set_No_Initialization (New_Allocator);
4968 Rewrite (Allocator, New_Allocator);
4970 -- Create a new access object and initialize it to the result of the
4971 -- new uninitialized allocator.
4973 Return_Obj_Access :=
4974 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4975 Set_Etype (Return_Obj_Access, Acc_Type);
4977 Insert_Action (Allocator,
4978 Make_Object_Declaration (Loc,
4979 Defining_Identifier => Return_Obj_Access,
4980 Object_Definition => New_Reference_To (Acc_Type, Loc),
4981 Expression => Relocate_Node (Allocator)));
4983 -- When the function has a controlling result, an allocation-form
4984 -- parameter must be passed indicating that the caller is allocating
4985 -- the result object. This is needed because such a function can be
4986 -- called as a dispatching operation and must be treated similarly
4987 -- to functions with unconstrained result subtypes.
4989 Add_Alloc_Form_Actual_To_Build_In_Place_Call
4990 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
4992 Add_Final_List_Actual_To_Build_In_Place_Call
4993 (Func_Call, Function_Id, Acc_Type);
4995 Add_Task_Actuals_To_Build_In_Place_Call
4996 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
4998 -- Add an implicit actual to the function call that provides access
4999 -- to the allocated object. An unchecked conversion to the (specific)
5000 -- result subtype of the function is inserted to handle cases where
5001 -- the access type of the allocator has a class-wide designated type.
5003 Add_Access_Actual_To_Build_In_Place_Call
5006 Make_Unchecked_Type_Conversion (Loc,
5007 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5009 Make_Explicit_Dereference (Loc,
5010 Prefix => New_Reference_To (Return_Obj_Access, Loc))));
5012 -- When the result subtype is unconstrained, the function itself must
5013 -- perform the allocation of the return object, so we pass parameters
5014 -- indicating that. We don't yet handle the case where the allocation
5015 -- must be done in a user-defined storage pool, which will require
5016 -- passing another actual or two to provide allocation/deallocation
5021 -- Pass an allocation parameter indicating that the function should
5022 -- allocate its result on the heap.
5024 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5025 (Func_Call, Function_Id, Alloc_Form => Global_Heap);
5027 Add_Final_List_Actual_To_Build_In_Place_Call
5028 (Func_Call, Function_Id, Acc_Type);
5030 Add_Task_Actuals_To_Build_In_Place_Call
5031 (Func_Call, Function_Id, Master_Actual => Master_Id (Acc_Type));
5033 -- The caller does not provide the return object in this case, so we
5034 -- have to pass null for the object access actual.
5036 Add_Access_Actual_To_Build_In_Place_Call
5037 (Func_Call, Function_Id, Return_Object => Empty);
5040 -- Finally, replace the allocator node with a reference to the result
5041 -- of the function call itself (which will effectively be an access
5042 -- to the object created by the allocator).
5044 Rewrite (Allocator, Make_Reference (Loc, Relocate_Node (Function_Call)));
5045 Analyze_And_Resolve (Allocator, Acc_Type);
5046 end Make_Build_In_Place_Call_In_Allocator;
5048 ---------------------------------------------------
5049 -- Make_Build_In_Place_Call_In_Anonymous_Context --
5050 ---------------------------------------------------
5052 procedure Make_Build_In_Place_Call_In_Anonymous_Context
5053 (Function_Call : Node_Id)
5056 Func_Call : Node_Id := Function_Call;
5057 Function_Id : Entity_Id;
5058 Result_Subt : Entity_Id;
5059 Return_Obj_Id : Entity_Id;
5060 Return_Obj_Decl : Entity_Id;
5063 -- Step past qualification or unchecked conversion (the latter can occur
5064 -- in cases of calls to 'Input).
5066 if Nkind_In (Func_Call, N_Qualified_Expression,
5067 N_Unchecked_Type_Conversion)
5069 Func_Call := Expression (Func_Call);
5072 -- If the call has already been processed to add build-in-place actuals
5073 -- then return. One place this can occur is for calls to build-in-place
5074 -- functions that occur within a call to a protected operation, where
5075 -- due to rewriting and expansion of the protected call there can be
5076 -- more than one call to Expand_Actuals for the same set of actuals.
5078 if Is_Expanded_Build_In_Place_Call (Func_Call) then
5082 -- Mark the call as processed as a build-in-place call
5084 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
5086 Loc := Sloc (Function_Call);
5088 if Is_Entity_Name (Name (Func_Call)) then
5089 Function_Id := Entity (Name (Func_Call));
5091 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5092 Function_Id := Etype (Name (Func_Call));
5095 raise Program_Error;
5098 Result_Subt := Etype (Function_Id);
5100 -- When the result subtype is constrained, an object of the subtype is
5101 -- declared and an access value designating it is passed as an actual.
5103 if Is_Constrained (Underlying_Type (Result_Subt)) then
5105 -- Create a temporary object to hold the function result
5108 Make_Defining_Identifier (Loc,
5109 Chars => New_Internal_Name ('R'));
5110 Set_Etype (Return_Obj_Id, Result_Subt);
5113 Make_Object_Declaration (Loc,
5114 Defining_Identifier => Return_Obj_Id,
5115 Aliased_Present => True,
5116 Object_Definition => New_Reference_To (Result_Subt, Loc));
5118 Set_No_Initialization (Return_Obj_Decl);
5120 Insert_Action (Func_Call, Return_Obj_Decl);
5122 -- When the function has a controlling result, an allocation-form
5123 -- parameter must be passed indicating that the caller is allocating
5124 -- the result object. This is needed because such a function can be
5125 -- called as a dispatching operation and must be treated similarly
5126 -- to functions with unconstrained result subtypes.
5128 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5129 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5131 Add_Final_List_Actual_To_Build_In_Place_Call
5132 (Func_Call, Function_Id, Acc_Type => Empty);
5134 Add_Task_Actuals_To_Build_In_Place_Call
5135 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5137 -- Add an implicit actual to the function call that provides access
5138 -- to the caller's return object.
5140 Add_Access_Actual_To_Build_In_Place_Call
5141 (Func_Call, Function_Id, New_Reference_To (Return_Obj_Id, Loc));
5143 -- When the result subtype is unconstrained, the function must allocate
5144 -- the return object in the secondary stack, so appropriate implicit
5145 -- parameters are added to the call to indicate that. A transient
5146 -- scope is established to ensure eventual cleanup of the result.
5150 -- Pass an allocation parameter indicating that the function should
5151 -- allocate its result on the secondary stack.
5153 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5154 (Func_Call, Function_Id, Alloc_Form => Secondary_Stack);
5156 Add_Final_List_Actual_To_Build_In_Place_Call
5157 (Func_Call, Function_Id, Acc_Type => Empty);
5159 Add_Task_Actuals_To_Build_In_Place_Call
5160 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5162 -- Pass a null value to the function since no return object is
5163 -- available on the caller side.
5165 Add_Access_Actual_To_Build_In_Place_Call
5166 (Func_Call, Function_Id, Empty);
5168 Establish_Transient_Scope (Func_Call, Sec_Stack => True);
5170 end Make_Build_In_Place_Call_In_Anonymous_Context;
5172 ---------------------------------------------------
5173 -- Make_Build_In_Place_Call_In_Assignment --
5174 ---------------------------------------------------
5176 procedure Make_Build_In_Place_Call_In_Assignment
5178 Function_Call : Node_Id)
5180 Lhs : constant Node_Id := Name (Assign);
5182 Func_Call : Node_Id := Function_Call;
5183 Function_Id : Entity_Id;
5184 Result_Subt : Entity_Id;
5185 Ref_Type : Entity_Id;
5186 Ptr_Typ_Decl : Node_Id;
5191 -- Step past qualification or unchecked conversion (the latter can occur
5192 -- in cases of calls to 'Input).
5194 if Nkind_In (Func_Call, N_Qualified_Expression,
5195 N_Unchecked_Type_Conversion)
5197 Func_Call := Expression (Func_Call);
5200 -- If the call has already been processed to add build-in-place actuals
5201 -- then return. This should not normally occur in an assignment context,
5202 -- but we add the protection as a defensive measure.
5204 if Is_Expanded_Build_In_Place_Call (Func_Call) then
5208 -- Mark the call as processed as a build-in-place call
5210 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
5212 Loc := Sloc (Function_Call);
5214 if Is_Entity_Name (Name (Func_Call)) then
5215 Function_Id := Entity (Name (Func_Call));
5217 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5218 Function_Id := Etype (Name (Func_Call));
5221 raise Program_Error;
5224 Result_Subt := Etype (Function_Id);
5226 -- When the result subtype is unconstrained, an additional actual must
5227 -- be passed to indicate that the caller is providing the return object.
5228 -- This parameter must also be passed when the called function has a
5229 -- controlling result, because dispatching calls to the function needs
5230 -- to be treated effectively the same as calls to class-wide functions.
5232 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5233 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5235 Add_Final_List_Actual_To_Build_In_Place_Call
5236 (Func_Call, Function_Id, Acc_Type => Empty);
5238 Add_Task_Actuals_To_Build_In_Place_Call
5239 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5241 -- Add an implicit actual to the function call that provides access to
5242 -- the caller's return object.
5244 Add_Access_Actual_To_Build_In_Place_Call
5247 Make_Unchecked_Type_Conversion (Loc,
5248 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5249 Expression => Relocate_Node (Lhs)));
5251 -- Create an access type designating the function's result subtype
5254 Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
5257 Make_Full_Type_Declaration (Loc,
5258 Defining_Identifier => Ref_Type,
5260 Make_Access_To_Object_Definition (Loc,
5261 All_Present => True,
5262 Subtype_Indication =>
5263 New_Reference_To (Result_Subt, Loc)));
5265 Insert_After_And_Analyze (Assign, Ptr_Typ_Decl);
5267 -- Finally, create an access object initialized to a reference to the
5271 Make_Defining_Identifier (Loc,
5272 Chars => New_Internal_Name ('R'));
5273 Set_Etype (Def_Id, Ref_Type);
5276 Make_Reference (Loc,
5277 Prefix => Relocate_Node (Func_Call));
5279 Insert_After_And_Analyze (Ptr_Typ_Decl,
5280 Make_Object_Declaration (Loc,
5281 Defining_Identifier => Def_Id,
5282 Object_Definition => New_Reference_To (Ref_Type, Loc),
5283 Expression => New_Expr));
5285 Rewrite (Assign, Make_Null_Statement (Loc));
5286 end Make_Build_In_Place_Call_In_Assignment;
5288 ----------------------------------------------------
5289 -- Make_Build_In_Place_Call_In_Object_Declaration --
5290 ----------------------------------------------------
5292 procedure Make_Build_In_Place_Call_In_Object_Declaration
5293 (Object_Decl : Node_Id;
5294 Function_Call : Node_Id)
5297 Obj_Def_Id : constant Entity_Id :=
5298 Defining_Identifier (Object_Decl);
5300 Func_Call : Node_Id := Function_Call;
5301 Function_Id : Entity_Id;
5302 Result_Subt : Entity_Id;
5303 Caller_Object : Node_Id;
5304 Call_Deref : Node_Id;
5305 Ref_Type : Entity_Id;
5306 Ptr_Typ_Decl : Node_Id;
5309 Enclosing_Func : Entity_Id;
5310 Pass_Caller_Acc : Boolean := False;
5313 -- Step past qualification or unchecked conversion (the latter can occur
5314 -- in cases of calls to 'Input).
5316 if Nkind_In (Func_Call, N_Qualified_Expression,
5317 N_Unchecked_Type_Conversion)
5319 Func_Call := Expression (Func_Call);
5322 -- If the call has already been processed to add build-in-place actuals
5323 -- then return. This should not normally occur in an object declaration,
5324 -- but we add the protection as a defensive measure.
5326 if Is_Expanded_Build_In_Place_Call (Func_Call) then
5330 -- Mark the call as processed as a build-in-place call
5332 Set_Is_Expanded_Build_In_Place_Call (Func_Call);
5334 Loc := Sloc (Function_Call);
5336 if Is_Entity_Name (Name (Func_Call)) then
5337 Function_Id := Entity (Name (Func_Call));
5339 elsif Nkind (Name (Func_Call)) = N_Explicit_Dereference then
5340 Function_Id := Etype (Name (Func_Call));
5343 raise Program_Error;
5346 Result_Subt := Etype (Function_Id);
5348 -- In the constrained case, add an implicit actual to the function call
5349 -- that provides access to the declared object. An unchecked conversion
5350 -- to the (specific) result type of the function is inserted to handle
5351 -- the case where the object is declared with a class-wide type.
5353 if Is_Constrained (Underlying_Type (Result_Subt)) then
5355 Make_Unchecked_Type_Conversion (Loc,
5356 Subtype_Mark => New_Reference_To (Result_Subt, Loc),
5357 Expression => New_Reference_To (Obj_Def_Id, Loc));
5359 -- When the function has a controlling result, an allocation-form
5360 -- parameter must be passed indicating that the caller is allocating
5361 -- the result object. This is needed because such a function can be
5362 -- called as a dispatching operation and must be treated similarly
5363 -- to functions with unconstrained result subtypes.
5365 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5366 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5368 -- If the function's result subtype is unconstrained and the object is
5369 -- a return object of an enclosing build-in-place function, then the
5370 -- implicit build-in-place parameters of the enclosing function must be
5371 -- passed along to the called function.
5373 elsif Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement then
5374 Pass_Caller_Acc := True;
5376 Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
5378 -- If the enclosing function has a constrained result type, then
5379 -- caller allocation will be used.
5381 if Is_Constrained (Etype (Enclosing_Func)) then
5382 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5383 (Func_Call, Function_Id, Alloc_Form => Caller_Allocation);
5385 -- Otherwise, when the enclosing function has an unconstrained result
5386 -- type, the BIP_Alloc_Form formal of the enclosing function must be
5387 -- passed along to the callee.
5390 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5395 (Build_In_Place_Formal (Enclosing_Func, BIP_Alloc_Form),
5399 -- Retrieve the BIPacc formal from the enclosing function and convert
5400 -- it to the access type of the callee's BIP_Object_Access formal.
5403 Make_Unchecked_Type_Conversion (Loc,
5407 (Build_In_Place_Formal (Function_Id, BIP_Object_Access)),
5411 (Build_In_Place_Formal (Enclosing_Func, BIP_Object_Access),
5414 -- In other unconstrained cases, pass an indication to do the allocation
5415 -- on the secondary stack and set Caller_Object to Empty so that a null
5416 -- value will be passed for the caller's object address. A transient
5417 -- scope is established to ensure eventual cleanup of the result.
5420 Add_Alloc_Form_Actual_To_Build_In_Place_Call
5423 Alloc_Form => Secondary_Stack);
5424 Caller_Object := Empty;
5426 Establish_Transient_Scope (Object_Decl, Sec_Stack => True);
5429 Add_Final_List_Actual_To_Build_In_Place_Call
5430 (Func_Call, Function_Id, Acc_Type => Empty);
5432 if Nkind (Parent (Object_Decl)) = N_Extended_Return_Statement
5433 and then Has_Task (Result_Subt)
5435 Enclosing_Func := Enclosing_Subprogram (Obj_Def_Id);
5437 -- Here we're passing along the master that was passed in to this
5440 Add_Task_Actuals_To_Build_In_Place_Call
5441 (Func_Call, Function_Id,
5444 (Build_In_Place_Formal (Enclosing_Func, BIP_Master), Loc));
5447 Add_Task_Actuals_To_Build_In_Place_Call
5448 (Func_Call, Function_Id, Make_Identifier (Loc, Name_uMaster));
5451 Add_Access_Actual_To_Build_In_Place_Call
5452 (Func_Call, Function_Id, Caller_Object, Is_Access => Pass_Caller_Acc);
5454 -- Create an access type designating the function's result subtype
5457 Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
5460 Make_Full_Type_Declaration (Loc,
5461 Defining_Identifier => Ref_Type,
5463 Make_Access_To_Object_Definition (Loc,
5464 All_Present => True,
5465 Subtype_Indication =>
5466 New_Reference_To (Result_Subt, Loc)));
5468 -- The access type and its accompanying object must be inserted after
5469 -- the object declaration in the constrained case, so that the function
5470 -- call can be passed access to the object. In the unconstrained case,
5471 -- the access type and object must be inserted before the object, since
5472 -- the object declaration is rewritten to be a renaming of a dereference
5473 -- of the access object.
5475 if Is_Constrained (Underlying_Type (Result_Subt)) then
5476 Insert_After_And_Analyze (Object_Decl, Ptr_Typ_Decl);
5478 Insert_Before_And_Analyze (Object_Decl, Ptr_Typ_Decl);
5481 -- Finally, create an access object initialized to a reference to the
5485 Make_Defining_Identifier (Loc,
5486 Chars => New_Internal_Name ('R'));
5487 Set_Etype (Def_Id, Ref_Type);
5490 Make_Reference (Loc,
5491 Prefix => Relocate_Node (Func_Call));
5493 Insert_After_And_Analyze (Ptr_Typ_Decl,
5494 Make_Object_Declaration (Loc,
5495 Defining_Identifier => Def_Id,
5496 Object_Definition => New_Reference_To (Ref_Type, Loc),
5497 Expression => New_Expr));
5499 if Is_Constrained (Underlying_Type (Result_Subt)) then
5500 Set_Expression (Object_Decl, Empty);
5501 Set_No_Initialization (Object_Decl);
5503 -- In case of an unconstrained result subtype, rewrite the object
5504 -- declaration as an object renaming where the renamed object is a
5505 -- dereference of <function_Call>'reference:
5507 -- Obj : Subt renames <function_call>'Ref.all;
5511 Make_Explicit_Dereference (Loc,
5512 Prefix => New_Reference_To (Def_Id, Loc));
5514 Rewrite (Object_Decl,
5515 Make_Object_Renaming_Declaration (Loc,
5516 Defining_Identifier => Make_Defining_Identifier (Loc,
5517 New_Internal_Name ('D')),
5518 Access_Definition => Empty,
5519 Subtype_Mark => New_Occurrence_Of (Result_Subt, Loc),
5520 Name => Call_Deref));
5522 Set_Renamed_Object (Defining_Identifier (Object_Decl), Call_Deref);
5524 Analyze (Object_Decl);
5526 -- Replace the internal identifier of the renaming declaration's
5527 -- entity with identifier of the original object entity. We also have
5528 -- to exchange the entities containing their defining identifiers to
5529 -- ensure the correct replacement of the object declaration by the
5530 -- object renaming declaration to avoid homograph conflicts (since
5531 -- the object declaration's defining identifier was already entered
5532 -- in current scope). The Next_Entity links of the two entities also
5533 -- have to be swapped since the entities are part of the return
5534 -- scope's entity list and the list structure would otherwise be
5538 Renaming_Def_Id : constant Entity_Id :=
5539 Defining_Identifier (Object_Decl);
5540 Next_Entity_Temp : constant Entity_Id :=
5541 Next_Entity (Renaming_Def_Id);
5543 Set_Chars (Renaming_Def_Id, Chars (Obj_Def_Id));
5545 -- Swap next entity links in preparation for exchanging entities
5547 Set_Next_Entity (Renaming_Def_Id, Next_Entity (Obj_Def_Id));
5548 Set_Next_Entity (Obj_Def_Id, Next_Entity_Temp);
5550 Exchange_Entities (Renaming_Def_Id, Obj_Def_Id);
5554 -- If the object entity has a class-wide Etype, then we need to change
5555 -- it to the result subtype of the function call, because otherwise the
5556 -- object will be class-wide without an explicit initialization and won't
5557 -- be allocated properly by the back end. It seems unclean to make such
5558 -- a revision to the type at this point, and we should try to improve
5559 -- this treatment when build-in-place functions with class-wide results
5560 -- are implemented. ???
5562 if Is_Class_Wide_Type (Etype (Defining_Identifier (Object_Decl))) then
5563 Set_Etype (Defining_Identifier (Object_Decl), Result_Subt);
5565 end Make_Build_In_Place_Call_In_Object_Declaration;