1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2002, Free Software Foundation, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- GNAT was originally developed by the GNAT team at New York University. --
25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
27 ------------------------------------------------------------------------------
29 with Atree; use Atree;
30 with Checks; use Checks;
31 with Debug; use Debug;
32 with Einfo; use Einfo;
33 with Errout; use Errout;
34 with Elists; use Elists;
35 with Exp_Ch2; use Exp_Ch2;
36 with Exp_Ch3; use Exp_Ch3;
37 with Exp_Ch7; use Exp_Ch7;
38 with Exp_Ch9; use Exp_Ch9;
39 with Exp_Ch11; use Exp_Ch11;
40 with Exp_Dbug; use Exp_Dbug;
41 with Exp_Disp; use Exp_Disp;
42 with Exp_Dist; use Exp_Dist;
43 with Exp_Intr; use Exp_Intr;
44 with Exp_Pakd; use Exp_Pakd;
45 with Exp_Tss; use Exp_Tss;
46 with Exp_Util; use Exp_Util;
47 with Freeze; use Freeze;
48 with Hostparm; use Hostparm;
49 with Inline; use Inline;
51 with Nlists; use Nlists;
52 with Nmake; use Nmake;
54 with Restrict; use Restrict;
55 with Rtsfind; use Rtsfind;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Ch12; use Sem_Ch12;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Disp; use Sem_Disp;
62 with Sem_Dist; use Sem_Dist;
63 with Sem_Res; use Sem_Res;
64 with Sem_Util; use Sem_Util;
65 with Sinfo; use Sinfo;
66 with Snames; use Snames;
67 with Stand; use Stand;
68 with Tbuild; use Tbuild;
69 with Uintp; use Uintp;
70 with Validsw; use Validsw;
72 package body Exp_Ch6 is
74 -----------------------
75 -- Local Subprograms --
76 -----------------------
78 procedure Check_Overriding_Operation (Subp : Entity_Id);
79 -- Subp is a dispatching operation. Check whether it may override an
80 -- inherited private operation, in which case its DT entry is that of
81 -- the hidden operation, not the one it may have received earlier.
82 -- This must be done before emitting the code to set the corresponding
83 -- DT to the address of the subprogram. The actual placement of Subp in
84 -- the proper place in the list of primitive operations is done in
85 -- Declare_Inherited_Private_Subprograms, which also has to deal with
86 -- implicit operations. This duplication is unavoidable for now???
88 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
89 -- This procedure is called only if the subprogram body N, whose spec
90 -- has the given entity Spec, contains a parameterless recursive call.
91 -- It attempts to generate runtime code to detect if this a case of
92 -- infinite recursion.
94 -- The body is scanned to determine dependencies. If the only external
95 -- dependencies are on a small set of scalar variables, then the values
96 -- of these variables are captured on entry to the subprogram, and if
97 -- the values are not changed for the call, we know immediately that
98 -- we have an infinite recursion.
100 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id);
101 -- For each actual of an in-out parameter which is a numeric conversion
102 -- of the form T(A), where A denotes a variable, we insert the declaration:
106 -- prior to the call. Then we replace the actual with a reference to Temp,
107 -- and append the assignment:
111 -- after the call. Here T' is the actual type of variable A.
112 -- For out parameters, the initial declaration has no expression.
113 -- If A is not an entity name, we generate instead:
115 -- Var : T' renames A;
116 -- Temp : T := Var; -- omitting expression for out parameter.
120 -- For other in-out parameters, we emit the required constraint checks
121 -- before and/or after the call.
123 -- For all parameter modes, actuals that denote components and slices
124 -- of packed arrays are expanded into suitable temporaries.
126 procedure Expand_Inlined_Call
129 Orig_Subp : Entity_Id);
130 -- If called subprogram can be inlined by the front-end, retrieve the
131 -- analyzed body, replace formals with actuals and expand call in place.
132 -- Generate thunks for actuals that are expressions, and insert the
133 -- corresponding constant declarations before the call. If the original
134 -- call is to a derived operation, the return type is the one of the
135 -- derived operation, but the body is that of the original, so return
136 -- expressions in the body must be converted to the desired type (which
137 -- is simply not noted in the tree without inline expansion).
139 function Expand_Protected_Object_Reference
144 procedure Expand_Protected_Subprogram_Call
148 -- A call to a protected subprogram within the protected object may appear
149 -- as a regular call. The list of actuals must be expanded to contain a
150 -- reference to the object itself, and the call becomes a call to the
151 -- corresponding protected subprogram.
153 --------------------------------
154 -- Check_Overriding_Operation --
155 --------------------------------
157 procedure Check_Overriding_Operation (Subp : Entity_Id) is
158 Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
159 Op_List : constant Elist_Id := Primitive_Operations (Typ);
165 if Is_Derived_Type (Typ)
166 and then not Is_Private_Type (Typ)
167 and then In_Open_Scopes (Scope (Etype (Typ)))
168 and then Typ = Base_Type (Typ)
170 -- Subp overrides an inherited private operation if there is
171 -- an inherited operation with a different name than Subp (see
172 -- Derive_Subprogram) whose Alias is a hidden subprogram with
173 -- the same name as Subp.
175 Op_Elmt := First_Elmt (Op_List);
176 while Present (Op_Elmt) loop
177 Prim_Op := Node (Op_Elmt);
178 Par_Op := Alias (Prim_Op);
181 and then not Comes_From_Source (Prim_Op)
182 and then Chars (Prim_Op) /= Chars (Par_Op)
183 and then Chars (Par_Op) = Chars (Subp)
184 and then Is_Hidden (Par_Op)
185 and then Type_Conformant (Prim_Op, Subp)
187 Set_DT_Position (Subp, DT_Position (Prim_Op));
193 end Check_Overriding_Operation;
195 -------------------------------
196 -- Detect_Infinite_Recursion --
197 -------------------------------
199 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
200 Loc : constant Source_Ptr := Sloc (N);
202 Var_List : Elist_Id := New_Elmt_List;
203 -- List of globals referenced by body of procedure
205 Call_List : Elist_Id := New_Elmt_List;
206 -- List of recursive calls in body of procedure
208 Shad_List : Elist_Id := New_Elmt_List;
209 -- List of entity id's for entities created to capture the
210 -- value of referenced globals on entry to the procedure.
212 Scop : constant Uint := Scope_Depth (Spec);
213 -- This is used to record the scope depth of the current
214 -- procedure, so that we can identify global references.
216 Max_Vars : constant := 4;
217 -- Do not test more than four global variables
219 Count_Vars : Natural := 0;
220 -- Count variables found so far
232 function Process (Nod : Node_Id) return Traverse_Result;
233 -- Function to traverse the subprogram body (using Traverse_Func)
239 function Process (Nod : Node_Id) return Traverse_Result is
243 if Nkind (Nod) = N_Procedure_Call_Statement then
245 -- Case of one of the detected recursive calls
247 if Is_Entity_Name (Name (Nod))
248 and then Has_Recursive_Call (Entity (Name (Nod)))
249 and then Entity (Name (Nod)) = Spec
251 Append_Elmt (Nod, Call_List);
254 -- Any other procedure call may have side effects
260 -- A call to a pure function can always be ignored
262 elsif Nkind (Nod) = N_Function_Call
263 and then Is_Entity_Name (Name (Nod))
264 and then Is_Pure (Entity (Name (Nod)))
268 -- Case of an identifier reference
270 elsif Nkind (Nod) = N_Identifier then
273 -- If no entity, then ignore the reference
275 -- Not clear why this can happen. To investigate, remove this
276 -- test and look at the crash that occurs here in 3401-004 ???
281 -- Ignore entities with no Scope, again not clear how this
282 -- can happen, to investigate, look at 4108-008 ???
284 elsif No (Scope (Ent)) then
287 -- Ignore the reference if not to a more global object
289 elsif Scope_Depth (Scope (Ent)) >= Scop then
292 -- References to types, exceptions and constants are always OK
295 or else Ekind (Ent) = E_Exception
296 or else Ekind (Ent) = E_Constant
300 -- If other than a non-volatile scalar variable, we have some
301 -- kind of global reference (e.g. to a function) that we cannot
302 -- deal with so we forget the attempt.
304 elsif Ekind (Ent) /= E_Variable
305 or else not Is_Scalar_Type (Etype (Ent))
306 or else Is_Volatile (Ent)
310 -- Otherwise we have a reference to a global scalar
313 -- Loop through global entities already detected
315 Elm := First_Elmt (Var_List);
317 -- If not detected before, record this new global reference
320 Count_Vars := Count_Vars + 1;
322 if Count_Vars <= Max_Vars then
323 Append_Elmt (Entity (Nod), Var_List);
330 -- If recorded before, ignore
332 elsif Node (Elm) = Entity (Nod) then
335 -- Otherwise keep looking
345 -- For all other node kinds, recursively visit syntactic children
352 function Traverse_Body is new Traverse_Func;
354 -- Start of processing for Detect_Infinite_Recursion
357 -- Do not attempt detection in No_Implicit_Conditional mode,
358 -- since we won't be able to generate the code to handle the
359 -- recursion in any case.
361 if Restrictions (No_Implicit_Conditionals) then
365 -- Otherwise do traversal and quit if we get abandon signal
367 if Traverse_Body (N) = Abandon then
370 -- We must have a call, since Has_Recursive_Call was set. If not
371 -- just ignore (this is only an error check, so if we have a funny
372 -- situation, due to bugs or errors, we do not want to bomb!)
374 elsif Is_Empty_Elmt_List (Call_List) then
378 -- Here is the case where we detect recursion at compile time
380 -- Push our current scope for analyzing the declarations and
381 -- code that we will insert for the checking.
385 -- This loop builds temporary variables for each of the
386 -- referenced globals, so that at the end of the loop the
387 -- list Shad_List contains these temporaries in one-to-one
388 -- correspondence with the elements in Var_List.
391 Elm := First_Elmt (Var_List);
392 while Present (Elm) loop
395 Make_Defining_Identifier (Loc,
396 Chars => New_Internal_Name ('S'));
397 Append_Elmt (Ent, Shad_List);
399 -- Insert a declaration for this temporary at the start of
400 -- the declarations for the procedure. The temporaries are
401 -- declared as constant objects initialized to the current
402 -- values of the corresponding temporaries.
405 Make_Object_Declaration (Loc,
406 Defining_Identifier => Ent,
407 Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
408 Constant_Present => True,
409 Expression => New_Occurrence_Of (Var, Loc));
412 Prepend (Decl, Declarations (N));
414 Insert_After (Last, Decl);
422 -- Loop through calls
424 Call := First_Elmt (Call_List);
425 while Present (Call) loop
427 -- Build a predicate expression of the form
430 -- and then global1 = temp1
431 -- and then global2 = temp2
434 -- This predicate determines if any of the global values
435 -- referenced by the procedure have changed since the
436 -- current call, if not an infinite recursion is assured.
438 Test := New_Occurrence_Of (Standard_True, Loc);
440 Elm1 := First_Elmt (Var_List);
441 Elm2 := First_Elmt (Shad_List);
442 while Present (Elm1) loop
448 Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
449 Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
455 -- Now we replace the call with the sequence
457 -- if no-changes (see above) then
458 -- raise Storage_Error;
463 Rewrite (Node (Call),
464 Make_If_Statement (Loc,
466 Then_Statements => New_List (
467 Make_Raise_Storage_Error (Loc,
468 Reason => SE_Infinite_Recursion)),
470 Else_Statements => New_List (
471 Relocate_Node (Node (Call)))));
473 Analyze (Node (Call));
478 -- Remove temporary scope stack entry used for analysis
481 end Detect_Infinite_Recursion;
487 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id) is
488 Loc : constant Source_Ptr := Sloc (N);
493 E_Formal : Entity_Id;
495 procedure Add_Call_By_Copy_Code;
496 -- For In and In-Out parameters, where the parameter must be passed
497 -- by copy, this routine generates a temporary variable into which
498 -- the actual is copied, and then passes this as the parameter. This
499 -- routine also takes care of any constraint checks required for the
500 -- type conversion case (on both the way in and the way out).
502 procedure Add_Packed_Call_By_Copy_Code;
503 -- This is used when the actual involves a reference to an element
504 -- of a packed array, where we can appropriately use a simpler
505 -- approach than the full call by copy code. We just copy the value
506 -- in and out of an appropriate temporary.
508 procedure Check_Fortran_Logical;
509 -- A value of type Logical that is passed through a formal parameter
510 -- must be normalized because .TRUE. usually does not have the same
511 -- representation as True. We assume that .FALSE. = False = 0.
512 -- What about functions that return a logical type ???
514 function Make_Var (Actual : Node_Id) return Entity_Id;
515 -- Returns an entity that refers to the given actual parameter,
516 -- Actual (not including any type conversion). If Actual is an
517 -- entity name, then this entity is returned unchanged, otherwise
518 -- a renaming is created to provide an entity for the actual.
520 procedure Reset_Packed_Prefix;
521 -- The expansion of a packed array component reference is delayed in
522 -- the context of a call. Now we need to complete the expansion, so we
523 -- unmark the analyzed bits in all prefixes.
525 ---------------------------
526 -- Add_Call_By_Copy_Code --
527 ---------------------------
529 procedure Add_Call_By_Copy_Code is
538 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
540 if Nkind (Actual) = N_Type_Conversion then
541 V_Typ := Etype (Expression (Actual));
542 Var := Make_Var (Expression (Actual));
543 Crep := not Same_Representation
544 (Etype (Formal), Etype (Expression (Actual)));
546 V_Typ := Etype (Actual);
547 Var := Make_Var (Actual);
551 -- Setup initialization for case of in out parameter, or an out
552 -- parameter where the formal is an unconstrained array (in the
553 -- latter case, we have to pass in an object with bounds).
555 if Ekind (Formal) = E_In_Out_Parameter
556 or else (Is_Array_Type (Etype (Formal))
558 not Is_Constrained (Etype (Formal)))
560 if Nkind (Actual) = N_Type_Conversion then
561 if Conversion_OK (Actual) then
562 Init := OK_Convert_To
563 (Etype (Formal), New_Occurrence_Of (Var, Loc));
566 (Etype (Formal), New_Occurrence_Of (Var, Loc));
569 Init := New_Occurrence_Of (Var, Loc);
572 -- An initialization is created for packed conversions as
573 -- actuals for out parameters to enable Make_Object_Declaration
574 -- to determine the proper subtype for N_Node. Note that this
575 -- is wasteful because the extra copying on the call side is
576 -- not required for such out parameters. ???
578 elsif Ekind (Formal) = E_Out_Parameter
579 and then Nkind (Actual) = N_Type_Conversion
580 and then (Is_Bit_Packed_Array (Etype (Formal))
582 Is_Bit_Packed_Array (Etype (Expression (Actual))))
584 if Conversion_OK (Actual) then
586 OK_Convert_To (Etype (Formal), New_Occurrence_Of (Var, Loc));
589 Convert_To (Etype (Formal), New_Occurrence_Of (Var, Loc));
596 Make_Object_Declaration (Loc,
597 Defining_Identifier => Temp,
599 New_Occurrence_Of (Etype (Formal), Loc),
601 Set_Assignment_OK (N_Node);
602 Insert_Action (N, N_Node);
604 -- Now, normally the deal here is that we use the defining
605 -- identifier created by that object declaration. There is
606 -- one exception to this. In the change of representation case
607 -- the above declaration will end up looking like:
609 -- temp : type := identifier;
611 -- And in this case we might as well use the identifier directly
612 -- and eliminate the temporary. Note that the analysis of the
613 -- declaration was not a waste of time in that case, since it is
614 -- what generated the necessary change of representation code. If
615 -- the change of representation introduced additional code, as in
616 -- a fixed-integer conversion, the expression is not an identifier
620 and then Present (Expression (N_Node))
621 and then Is_Entity_Name (Expression (N_Node))
623 Temp := Entity (Expression (N_Node));
624 Rewrite (N_Node, Make_Null_Statement (Loc));
627 -- If type conversion, use reverse conversion on exit
629 if Nkind (Actual) = N_Type_Conversion then
630 if Conversion_OK (Actual) then
631 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
633 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
636 Expr := New_Occurrence_Of (Temp, Loc);
639 Rewrite (Actual, New_Reference_To (Temp, Loc));
642 Append_To (Post_Call,
643 Make_Assignment_Statement (Loc,
644 Name => New_Occurrence_Of (Var, Loc),
645 Expression => Expr));
647 Set_Assignment_OK (Name (Last (Post_Call)));
648 end Add_Call_By_Copy_Code;
650 ----------------------------------
651 -- Add_Packed_Call_By_Copy_Code --
652 ----------------------------------
654 procedure Add_Packed_Call_By_Copy_Code is
664 -- Prepare to generate code
666 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
667 Incod := Relocate_Node (Actual);
668 Outcod := New_Copy_Tree (Incod);
670 -- Generate declaration of temporary variable, initializing it
671 -- with the input parameter unless we have an OUT variable.
673 if Ekind (Formal) = E_Out_Parameter then
678 Make_Object_Declaration (Loc,
679 Defining_Identifier => Temp,
681 New_Occurrence_Of (Etype (Formal), Loc),
682 Expression => Incod));
684 -- The actual is simply a reference to the temporary
686 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
688 -- Generate copy out if OUT or IN OUT parameter
690 if Ekind (Formal) /= E_In_Parameter then
692 Rhs := New_Occurrence_Of (Temp, Loc);
694 -- Deal with conversion
696 if Nkind (Lhs) = N_Type_Conversion then
697 Lhs := Expression (Lhs);
698 Rhs := Convert_To (Etype (Actual), Rhs);
701 Append_To (Post_Call,
702 Make_Assignment_Statement (Loc,
706 end Add_Packed_Call_By_Copy_Code;
708 ---------------------------
709 -- Check_Fortran_Logical --
710 ---------------------------
712 procedure Check_Fortran_Logical is
713 Logical : Entity_Id := Etype (Formal);
716 -- Note: this is very incomplete, e.g. it does not handle arrays
717 -- of logical values. This is really not the right approach at all???)
720 if Convention (Subp) = Convention_Fortran
721 and then Root_Type (Etype (Formal)) = Standard_Boolean
722 and then Ekind (Formal) /= E_In_Parameter
724 Var := Make_Var (Actual);
725 Append_To (Post_Call,
726 Make_Assignment_Statement (Loc,
727 Name => New_Occurrence_Of (Var, Loc),
729 Unchecked_Convert_To (
732 Left_Opnd => New_Occurrence_Of (Var, Loc),
734 Unchecked_Convert_To (
736 New_Occurrence_Of (Standard_False, Loc))))));
738 end Check_Fortran_Logical;
744 function Make_Var (Actual : Node_Id) return Entity_Id is
748 if Is_Entity_Name (Actual) then
749 return Entity (Actual);
752 Var := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
755 Make_Object_Renaming_Declaration (Loc,
756 Defining_Identifier => Var,
758 New_Occurrence_Of (Etype (Actual), Loc),
759 Name => Relocate_Node (Actual));
761 Insert_Action (N, N_Node);
766 -------------------------
767 -- Reset_Packed_Prefix --
768 -------------------------
770 procedure Reset_Packed_Prefix is
771 Pfx : Node_Id := Actual;
775 Set_Analyzed (Pfx, False);
776 exit when Nkind (Pfx) /= N_Selected_Component
777 and then Nkind (Pfx) /= N_Indexed_Component;
780 end Reset_Packed_Prefix;
782 -- Start of processing for Expand_Actuals
785 Formal := First_Formal (Subp);
786 Actual := First_Actual (N);
788 Post_Call := New_List;
790 while Present (Formal) loop
791 E_Formal := Etype (Formal);
793 if Is_Scalar_Type (E_Formal)
794 or else Nkind (Actual) = N_Slice
796 Check_Fortran_Logical;
800 elsif Ekind (Formal) /= E_Out_Parameter then
802 -- The unusual case of the current instance of a protected type
803 -- requires special handling. This can only occur in the context
804 -- of a call within the body of a protected operation.
806 if Is_Entity_Name (Actual)
807 and then Ekind (Entity (Actual)) = E_Protected_Type
808 and then In_Open_Scopes (Entity (Actual))
810 if Scope (Subp) /= Entity (Actual) then
811 Error_Msg_N ("operation outside protected type may not "
812 & "call back its protected operations?", Actual);
816 Expand_Protected_Object_Reference (N, Entity (Actual)));
819 Apply_Constraint_Check (Actual, E_Formal);
821 -- Out parameter case. No constraint checks on access type
824 elsif Is_Access_Type (E_Formal) then
829 elsif Has_Discriminants (Base_Type (E_Formal))
830 or else Has_Non_Null_Base_Init_Proc (E_Formal)
832 Apply_Constraint_Check (Actual, E_Formal);
837 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
840 -- Processing for IN-OUT and OUT parameters
842 if Ekind (Formal) /= E_In_Parameter then
844 -- For type conversions of arrays, apply length/range checks
846 if Is_Array_Type (E_Formal)
847 and then Nkind (Actual) = N_Type_Conversion
849 if Is_Constrained (E_Formal) then
850 Apply_Length_Check (Expression (Actual), E_Formal);
852 Apply_Range_Check (Expression (Actual), E_Formal);
856 -- If argument is a type conversion for a type that is passed
857 -- by copy, then we must pass the parameter by copy.
859 if Nkind (Actual) = N_Type_Conversion
861 (Is_Numeric_Type (E_Formal)
862 or else Is_Access_Type (E_Formal)
863 or else Is_Enumeration_Type (E_Formal)
864 or else Is_Bit_Packed_Array (Etype (Formal))
865 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
867 -- Also pass by copy if change of representation
869 or else not Same_Representation
871 Etype (Expression (Actual))))
873 Add_Call_By_Copy_Code;
875 -- References to components of bit packed arrays are expanded
876 -- at this point, rather than at the point of analysis of the
877 -- actuals, to handle the expansion of the assignment to
878 -- [in] out parameters.
880 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
881 Add_Packed_Call_By_Copy_Code;
883 -- References to slices of bit packed arrays are expanded
885 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
886 Add_Call_By_Copy_Code;
888 -- Deal with access types where the actual subtpe and the
889 -- formal subtype are not the same, requiring a check.
891 -- It is necessary to exclude tagged types because of "downward
892 -- conversion" errors and a strange assertion error in namet
893 -- from gnatf in bug 1215-001 ???
895 elsif Is_Access_Type (E_Formal)
896 and then not Same_Type (E_Formal, Etype (Actual))
897 and then not Is_Tagged_Type (Designated_Type (E_Formal))
899 Add_Call_By_Copy_Code;
901 elsif Is_Entity_Name (Actual)
902 and then Is_Volatile (Entity (Actual))
903 and then not Is_Scalar_Type (Etype (Entity (Actual)))
904 and then not Is_Volatile (E_Formal)
906 Add_Call_By_Copy_Code;
908 elsif Nkind (Actual) = N_Indexed_Component
909 and then Is_Entity_Name (Prefix (Actual))
910 and then Has_Volatile_Components (Entity (Prefix (Actual)))
912 Add_Call_By_Copy_Code;
915 -- The only processing required for IN parameters is in the packed
916 -- array case, where we expand the indexed component (the circuit
917 -- in Exp_Ch4 deliberately left indexed components appearing as
918 -- actuals untouched, so that the special processing above for
919 -- the OUT and IN OUT cases could be performed. We could make the
920 -- test in Exp_Ch4 more complex and have it detect the parameter
921 -- mode, but it is easier simply to handle all cases here.
923 -- Similarly, we have to expand slices of packed arrays here
926 if Nkind (Actual) = N_Indexed_Component
927 and then Is_Packed (Etype (Prefix (Actual)))
930 Expand_Packed_Element_Reference (Actual);
932 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
933 Add_Packed_Call_By_Copy_Code;
935 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
937 Typ : constant Entity_Id := Etype (Actual);
939 Ent : constant Entity_Id :=
940 Make_Defining_Identifier (Loc,
941 Chars => New_Internal_Name ('T'));
943 Decl : constant Node_Id :=
944 Make_Object_Declaration (Loc,
945 Defining_Identifier => Ent,
947 New_Occurrence_Of (Typ, Loc));
950 Set_No_Initialization (Decl);
952 Insert_Actions (N, New_List (
954 Make_Assignment_Statement (Loc,
955 Name => New_Occurrence_Of (Ent, Loc),
956 Expression => Relocate_Node (Actual))));
959 (Actual, New_Occurrence_Of (Ent, Loc));
960 Analyze_And_Resolve (Actual, Typ);
965 Next_Formal (Formal);
966 Next_Actual (Actual);
969 -- Find right place to put post call stuff if it is present
971 if not Is_Empty_List (Post_Call) then
973 -- If call is not a list member, it must be the triggering
974 -- statement of a triggering alternative or an entry call
975 -- alternative, and we can add the post call stuff to the
976 -- corresponding statement list.
978 if not Is_List_Member (N) then
980 P : constant Node_Id := Parent (N);
983 pragma Assert (Nkind (P) = N_Triggering_Alternative
984 or else Nkind (P) = N_Entry_Call_Alternative);
986 if Is_Non_Empty_List (Statements (P)) then
987 Insert_List_Before_And_Analyze
988 (First (Statements (P)), Post_Call);
990 Set_Statements (P, Post_Call);
994 -- Otherwise, normal case where N is in a statement sequence,
995 -- just put the post-call stuff after the call statement.
998 Insert_Actions_After (N, Post_Call);
1002 -- The call node itself is re-analyzed in Expand_Call.
1010 -- This procedure handles expansion of function calls and procedure call
1011 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1012 -- Expand_N_Procedure_Call_Statement. Processing for calls includes:
1014 -- Replace call to Raise_Exception by Raise_Exception always if possible
1015 -- Provide values of actuals for all formals in Extra_Formals list
1016 -- Replace "call" to enumeration literal function by literal itself
1017 -- Rewrite call to predefined operator as operator
1018 -- Replace actuals to in-out parameters that are numeric conversions,
1019 -- with explicit assignment to temporaries before and after the call.
1020 -- Remove optional actuals if First_Optional_Parameter specified.
1022 -- Note that the list of actuals has been filled with default expressions
1023 -- during semantic analysis of the call. Only the extra actuals required
1024 -- for the 'Constrained attribute and for accessibility checks are added
1027 procedure Expand_Call (N : Node_Id) is
1028 Loc : constant Source_Ptr := Sloc (N);
1029 Remote : constant Boolean := Is_Remote_Call (N);
1031 Orig_Subp : Entity_Id := Empty;
1032 Parent_Subp : Entity_Id;
1033 Parent_Formal : Entity_Id;
1036 Prev : Node_Id := Empty;
1037 Prev_Orig : Node_Id;
1039 Extra_Actuals : List_Id := No_List;
1042 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1043 -- Adds one entry to the end of the actual parameter list. Used for
1044 -- default parameters and for extra actuals (for Extra_Formals).
1045 -- The argument is an N_Parameter_Association node.
1047 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1048 -- Adds an extra actual to the list of extra actuals. Expr
1049 -- is the expression for the value of the actual, EF is the
1050 -- entity for the extra formal.
1052 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1053 -- Within an instance, a type derived from a non-tagged formal derived
1054 -- type inherits from the original parent, not from the actual. This is
1055 -- tested in 4723-003. The current derivation mechanism has the derived
1056 -- type inherit from the actual, which is only correct outside of the
1057 -- instance. If the subprogram is inherited, we test for this particular
1058 -- case through a convoluted tree traversal before setting the proper
1059 -- subprogram to be called.
1061 --------------------------
1062 -- Add_Actual_Parameter --
1063 --------------------------
1065 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1066 Actual_Expr : constant Node_Id :=
1067 Explicit_Actual_Parameter (Insert_Param);
1070 -- Case of insertion is first named actual
1072 if No (Prev) or else
1073 Nkind (Parent (Prev)) /= N_Parameter_Association
1075 Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
1076 Set_First_Named_Actual (N, Actual_Expr);
1079 if not Present (Parameter_Associations (N)) then
1080 Set_Parameter_Associations (N, New_List);
1081 Append (Insert_Param, Parameter_Associations (N));
1084 Insert_After (Prev, Insert_Param);
1087 -- Case of insertion is not first named actual
1090 Set_Next_Named_Actual
1091 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1092 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1093 Append (Insert_Param, Parameter_Associations (N));
1096 Prev := Actual_Expr;
1097 end Add_Actual_Parameter;
1099 ----------------------
1100 -- Add_Extra_Actual --
1101 ----------------------
1103 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1104 Loc : constant Source_Ptr := Sloc (Expr);
1107 if Extra_Actuals = No_List then
1108 Extra_Actuals := New_List;
1109 Set_Parent (Extra_Actuals, N);
1112 Append_To (Extra_Actuals,
1113 Make_Parameter_Association (Loc,
1114 Explicit_Actual_Parameter => Expr,
1116 Make_Identifier (Loc, Chars (EF))));
1118 Analyze_And_Resolve (Expr, Etype (EF));
1120 end Add_Extra_Actual;
1122 ---------------------------
1123 -- Inherited_From_Formal --
1124 ---------------------------
1126 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1128 Gen_Par : Entity_Id;
1129 Gen_Prim : Elist_Id;
1134 -- If the operation is inherited, it is attached to the corresponding
1135 -- type derivation. If the parent in the derivation is a generic
1136 -- actual, it is a subtype of the actual, and we have to recover the
1137 -- original derived type declaration to find the proper parent.
1139 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1140 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1141 or else Nkind (Type_Definition (Original_Node (Parent (S))))
1142 /= N_Derived_Type_Definition
1149 (Type_Definition (Original_Node (Parent (S)))));
1151 if Nkind (Indic) = N_Subtype_Indication then
1152 Par := Entity (Subtype_Mark (Indic));
1154 Par := Entity (Indic);
1158 if not Is_Generic_Actual_Type (Par)
1159 or else Is_Tagged_Type (Par)
1160 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1161 or else not In_Open_Scopes (Scope (Par))
1162 or else not In_Instance
1167 Gen_Par := Generic_Parent_Type (Parent (Par));
1170 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
1171 Elmt := First_Elmt (Gen_Prim);
1173 while Present (Elmt) loop
1174 if Chars (Node (Elmt)) = Chars (S) then
1180 F1 := First_Formal (S);
1181 F2 := First_Formal (Node (Elmt));
1184 and then Present (F2)
1187 if Etype (F1) = Etype (F2)
1188 or else Etype (F2) = Gen_Par
1194 exit; -- not the right subprogram
1206 raise Program_Error;
1207 end Inherited_From_Formal;
1209 -- Start of processing for Expand_Call
1212 -- Ignore if previous error
1214 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1218 -- Call using access to subprogram with explicit dereference
1220 if Nkind (Name (N)) = N_Explicit_Dereference then
1221 Subp := Etype (Name (N));
1222 Parent_Subp := Empty;
1224 -- Case of call to simple entry, where the Name is a selected component
1225 -- whose prefix is the task, and whose selector name is the entry name
1227 elsif Nkind (Name (N)) = N_Selected_Component then
1228 Subp := Entity (Selector_Name (Name (N)));
1229 Parent_Subp := Empty;
1231 -- Case of call to member of entry family, where Name is an indexed
1232 -- component, with the prefix being a selected component giving the
1233 -- task and entry family name, and the index being the entry index.
1235 elsif Nkind (Name (N)) = N_Indexed_Component then
1236 Subp := Entity (Selector_Name (Prefix (Name (N))));
1237 Parent_Subp := Empty;
1242 Subp := Entity (Name (N));
1243 Parent_Subp := Alias (Subp);
1245 -- Replace call to Raise_Exception by call to Raise_Exception_Always
1246 -- if we can tell that the first parameter cannot possibly be null.
1248 if not Restrictions (No_Exception_Handlers)
1249 and then Is_RTE (Subp, RE_Raise_Exception)
1252 FA : constant Node_Id := Original_Node (First_Actual (N));
1255 -- The case we catch is where the first argument is obtained
1256 -- using the Identity attribute (which must always be non-null)
1258 if Nkind (FA) = N_Attribute_Reference
1259 and then Attribute_Name (FA) = Name_Identity
1261 Subp := RTE (RE_Raise_Exception_Always);
1262 Set_Entity (Name (N), Subp);
1267 if Ekind (Subp) = E_Entry then
1268 Parent_Subp := Empty;
1272 -- First step, compute extra actuals, corresponding to any
1273 -- Extra_Formals present. Note that we do not access Extra_Formals
1274 -- directly, instead we simply note the presence of the extra
1275 -- formals as we process the regular formals and collect the
1276 -- corresponding actuals in Extra_Actuals.
1278 Formal := First_Formal (Subp);
1279 Actual := First_Actual (N);
1281 while Present (Formal) loop
1283 Prev_Orig := Original_Node (Prev);
1285 -- Create possible extra actual for constrained case. Usually,
1286 -- the extra actual is of the form actual'constrained, but since
1287 -- this attribute is only available for unconstrained records,
1288 -- TRUE is expanded if the type of the formal happens to be
1289 -- constrained (for instance when this procedure is inherited
1290 -- from an unconstrained record to a constrained one) or if the
1291 -- actual has no discriminant (its type is constrained). An
1292 -- exception to this is the case of a private type without
1293 -- discriminants. In this case we pass FALSE because the
1294 -- object has underlying discriminants with defaults.
1296 if Present (Extra_Constrained (Formal)) then
1297 if Ekind (Etype (Prev)) in Private_Kind
1298 and then not Has_Discriminants (Base_Type (Etype (Prev)))
1301 New_Occurrence_Of (Standard_False, Loc),
1302 Extra_Constrained (Formal));
1304 elsif Is_Constrained (Etype (Formal))
1305 or else not Has_Discriminants (Etype (Prev))
1308 New_Occurrence_Of (Standard_True, Loc),
1309 Extra_Constrained (Formal));
1312 -- If the actual is a type conversion, then the constrained
1313 -- test applies to the actual, not the target type.
1316 Act_Prev : Node_Id := Prev;
1319 -- Test for unchecked conversions as well, which can
1320 -- occur as out parameter actuals on calls to stream
1323 if Nkind (Act_Prev) = N_Type_Conversion
1324 or else Nkind (Act_Prev) = N_Unchecked_Type_Conversion
1326 Act_Prev := Expression (Act_Prev);
1330 Make_Attribute_Reference (Sloc (Prev),
1331 Prefix => Duplicate_Subexpr (Act_Prev, Name_Req => True),
1332 Attribute_Name => Name_Constrained),
1333 Extra_Constrained (Formal));
1338 -- Create possible extra actual for accessibility level
1340 if Present (Extra_Accessibility (Formal)) then
1341 if Is_Entity_Name (Prev_Orig) then
1343 -- When passing an access parameter as the actual to another
1344 -- access parameter we need to pass along the actual's own
1345 -- associated access level parameter. This is done is we are
1346 -- in the scope of the formal access parameter (if this is an
1347 -- inlined body the extra formal is irrelevant).
1349 if Ekind (Entity (Prev_Orig)) in Formal_Kind
1350 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
1351 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
1354 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
1357 pragma Assert (Present (Parm_Ent));
1359 if Present (Extra_Accessibility (Parm_Ent)) then
1362 (Extra_Accessibility (Parm_Ent), Loc),
1363 Extra_Accessibility (Formal));
1365 -- If the actual access parameter does not have an
1366 -- associated extra formal providing its scope level,
1367 -- then treat the actual as having library-level
1372 Make_Integer_Literal (Loc,
1373 Intval => Scope_Depth (Standard_Standard)),
1374 Extra_Accessibility (Formal));
1378 -- The actual is a normal access value, so just pass the
1379 -- level of the actual's access type.
1383 Make_Integer_Literal (Loc,
1384 Intval => Type_Access_Level (Etype (Prev_Orig))),
1385 Extra_Accessibility (Formal));
1389 case Nkind (Prev_Orig) is
1391 when N_Attribute_Reference =>
1393 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
1395 -- For X'Access, pass on the level of the prefix X
1397 when Attribute_Access =>
1399 Make_Integer_Literal (Loc,
1401 Object_Access_Level (Prefix (Prev_Orig))),
1402 Extra_Accessibility (Formal));
1404 -- Treat the unchecked attributes as library-level
1406 when Attribute_Unchecked_Access |
1407 Attribute_Unrestricted_Access =>
1409 Make_Integer_Literal (Loc,
1410 Intval => Scope_Depth (Standard_Standard)),
1411 Extra_Accessibility (Formal));
1413 -- No other cases of attributes returning access
1414 -- values that can be passed to access parameters
1417 raise Program_Error;
1421 -- For allocators we pass the level of the execution of
1422 -- the called subprogram, which is one greater than the
1423 -- current scope level.
1427 Make_Integer_Literal (Loc,
1428 Scope_Depth (Current_Scope) + 1),
1429 Extra_Accessibility (Formal));
1431 -- For other cases we simply pass the level of the
1432 -- actual's access type.
1436 Make_Integer_Literal (Loc,
1437 Intval => Type_Access_Level (Etype (Prev_Orig))),
1438 Extra_Accessibility (Formal));
1444 -- Perform the check of 4.6(49) that prevents a null value
1445 -- from being passed as an actual to an access parameter.
1446 -- Note that the check is elided in the common cases of
1447 -- passing an access attribute or access parameter as an
1448 -- actual. Also, we currently don't enforce this check for
1449 -- expander-generated actuals and when -gnatdj is set.
1451 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
1452 or else Suppress_Accessibility_Checks (Subp)
1456 elsif Debug_Flag_J then
1459 elsif not Comes_From_Source (Prev) then
1462 elsif Is_Entity_Name (Prev)
1463 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
1467 elsif Nkind (Prev) = N_Allocator
1468 or else Nkind (Prev) = N_Attribute_Reference
1472 -- Suppress null checks when passing to access parameters
1473 -- of Java subprograms. (Should this be done for other
1474 -- foreign conventions as well ???)
1476 elsif Convention (Subp) = Convention_Java then
1482 Left_Opnd => Duplicate_Subexpr (Prev),
1483 Right_Opnd => Make_Null (Loc));
1484 Insert_Action (Prev,
1485 Make_Raise_Constraint_Error (Loc,
1487 Reason => CE_Access_Parameter_Is_Null));
1490 -- Perform appropriate validity checks on parameters
1492 if Validity_Checks_On then
1494 if Ekind (Formal) = E_In_Parameter
1495 and then Validity_Check_In_Params
1497 Ensure_Valid (Actual);
1499 elsif Ekind (Formal) = E_In_Out_Parameter
1500 and then Validity_Check_In_Out_Params
1502 Ensure_Valid (Actual);
1506 -- For IN OUT and OUT parameters, ensure that subscripts are valid
1507 -- since this is a left side reference. We only do this for calls
1508 -- from the source program since we assume that compiler generated
1509 -- calls explicitly generate any required checks. We also need it
1510 -- only if we are doing standard validity checks, since clearly it
1511 -- is not needed if validity checks are off, and in subscript
1512 -- validity checking mode, all indexed components are checked with
1513 -- a call directly from Expand_N_Indexed_Component.
1515 if Comes_From_Source (N)
1516 and then Ekind (Formal) /= E_In_Parameter
1517 and then Validity_Checks_On
1518 and then Validity_Check_Default
1519 and then not Validity_Check_Subscripts
1521 Check_Valid_Lvalue_Subscripts (Actual);
1524 -- If the formal is class wide and the actual is an aggregate, force
1525 -- evaluation so that the back end who does not know about class-wide
1526 -- type, does not generate a temporary of the wrong size.
1528 if not Is_Class_Wide_Type (Etype (Formal)) then
1531 elsif Nkind (Actual) = N_Aggregate
1532 or else (Nkind (Actual) = N_Qualified_Expression
1533 and then Nkind (Expression (Actual)) = N_Aggregate)
1535 Force_Evaluation (Actual);
1538 -- In a remote call, if the formal is of a class-wide type, check
1539 -- that the actual meets the requirements described in E.4(18).
1542 and then Is_Class_Wide_Type (Etype (Formal))
1544 Insert_Action (Actual,
1545 Make_Implicit_If_Statement (N,
1548 Get_Remotely_Callable (Duplicate_Subexpr (Actual))),
1549 Then_Statements => New_List (
1550 Make_Procedure_Call_Statement (Loc,
1551 New_Occurrence_Of (RTE
1552 (RE_Raise_Program_Error_For_E_4_18), Loc)))));
1555 Next_Actual (Actual);
1556 Next_Formal (Formal);
1559 -- If we are expanding a rhs of an assignement we need to check if
1560 -- tag propagation is needed. This code belongs theorically in Analyze
1561 -- Assignment but has to be done earlier (bottom-up) because the
1562 -- assignment might be transformed into a declaration for an uncons-
1563 -- trained value, if the expression is classwide.
1565 if Nkind (N) = N_Function_Call
1566 and then Is_Tag_Indeterminate (N)
1567 and then Is_Entity_Name (Name (N))
1570 Ass : Node_Id := Empty;
1573 if Nkind (Parent (N)) = N_Assignment_Statement then
1576 elsif Nkind (Parent (N)) = N_Qualified_Expression
1577 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
1579 Ass := Parent (Parent (N));
1583 and then Is_Class_Wide_Type (Etype (Name (Ass)))
1585 Propagate_Tag (Name (Ass), N);
1591 -- Deals with Dispatch_Call if we still have a call, before expanding
1592 -- extra actuals since this will be done on the re-analysis of the
1593 -- dispatching call. Note that we do not try to shorten the actual
1594 -- list for a dispatching call, it would not make sense to do so.
1595 -- Expansion of dispatching calls is suppressed when Java_VM, because
1596 -- the JVM back end directly handles the generation of dispatching
1597 -- calls and would have to undo any expansion to an indirect call.
1599 if (Nkind (N) = N_Function_Call
1600 or else Nkind (N) = N_Procedure_Call_Statement)
1601 and then Present (Controlling_Argument (N))
1602 and then not Java_VM
1604 Expand_Dispatch_Call (N);
1607 -- Similarly, expand calls to RCI subprograms on which pragma
1608 -- All_Calls_Remote applies. The rewriting will be reanalyzed
1609 -- later. Do this only when the call comes from source since we do
1610 -- not want such a rewritting to occur in expanded code.
1612 elsif Is_All_Remote_Call (N) then
1613 Expand_All_Calls_Remote_Subprogram_Call (N);
1615 -- Similarly, do not add extra actuals for an entry call whose entity
1616 -- is a protected procedure, or for an internal protected subprogram
1617 -- call, because it will be rewritten as a protected subprogram call
1618 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
1620 elsif Is_Protected_Type (Scope (Subp))
1621 and then (Ekind (Subp) = E_Procedure
1622 or else Ekind (Subp) = E_Function)
1626 -- During that loop we gathered the extra actuals (the ones that
1627 -- correspond to Extra_Formals), so now they can be appended.
1630 while Is_Non_Empty_List (Extra_Actuals) loop
1631 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
1635 if Ekind (Subp) = E_Procedure
1636 or else (Ekind (Subp) = E_Subprogram_Type
1637 and then Etype (Subp) = Standard_Void_Type)
1638 or else Is_Entry (Subp)
1640 Expand_Actuals (N, Subp);
1643 -- If the subprogram is a renaming, or if it is inherited, replace it
1644 -- in the call with the name of the actual subprogram being called.
1645 -- If this is a dispatching call, the run-time decides what to call.
1646 -- The Alias attribute does not apply to entries.
1648 if Nkind (N) /= N_Entry_Call_Statement
1649 and then No (Controlling_Argument (N))
1650 and then Present (Parent_Subp)
1652 if Present (Inherited_From_Formal (Subp)) then
1653 Parent_Subp := Inherited_From_Formal (Subp);
1655 while Present (Alias (Parent_Subp)) loop
1656 Parent_Subp := Alias (Parent_Subp);
1660 Set_Entity (Name (N), Parent_Subp);
1662 if Is_Abstract (Parent_Subp)
1663 and then not In_Instance
1666 ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
1669 -- Add an explicit conversion for parameter of the derived type.
1670 -- This is only done for scalar and access in-parameters. Others
1671 -- have been expanded in expand_actuals.
1673 Formal := First_Formal (Subp);
1674 Parent_Formal := First_Formal (Parent_Subp);
1675 Actual := First_Actual (N);
1677 -- It is not clear that conversion is needed for intrinsic
1678 -- subprograms, but it certainly is for those that are user-
1679 -- defined, and that can be inherited on derivation, namely
1680 -- unchecked conversion and deallocation.
1681 -- General case needs study ???
1683 if not Is_Intrinsic_Subprogram (Parent_Subp)
1684 or else Is_Generic_Instance (Parent_Subp)
1686 while Present (Formal) loop
1688 if Etype (Formal) /= Etype (Parent_Formal)
1689 and then Is_Scalar_Type (Etype (Formal))
1690 and then Ekind (Formal) = E_In_Parameter
1691 and then not Raises_Constraint_Error (Actual)
1694 OK_Convert_To (Etype (Parent_Formal),
1695 Relocate_Node (Actual)));
1698 Resolve (Actual, Etype (Parent_Formal));
1699 Enable_Range_Check (Actual);
1701 elsif Is_Access_Type (Etype (Formal))
1702 and then Base_Type (Etype (Parent_Formal))
1703 /= Base_Type (Etype (Actual))
1705 if Ekind (Formal) /= E_In_Parameter then
1707 Convert_To (Etype (Parent_Formal),
1708 Relocate_Node (Actual)));
1711 Resolve (Actual, Etype (Parent_Formal));
1714 Ekind (Etype (Parent_Formal)) = E_Anonymous_Access_Type
1716 Designated_Type (Etype (Parent_Formal))
1717 /= Designated_Type (Etype (Actual))
1718 and then not Is_Controlling_Formal (Formal)
1721 -- This unchecked conversion is not necessary unless
1722 -- inlining is unabled, because in that case the type
1723 -- mismatch may become visible in the body about to be
1727 Unchecked_Convert_To (Etype (Parent_Formal),
1728 Relocate_Node (Actual)));
1731 Resolve (Actual, Etype (Parent_Formal));
1735 Next_Formal (Formal);
1736 Next_Formal (Parent_Formal);
1737 Next_Actual (Actual);
1742 Subp := Parent_Subp;
1745 -- Some more special cases for cases other than explicit dereference
1747 if Nkind (Name (N)) /= N_Explicit_Dereference then
1749 -- Calls to an enumeration literal are replaced by the literal
1750 -- This case occurs only when we have a call to a function that
1751 -- is a renaming of an enumeration literal. The normal case of
1752 -- a direct reference to an enumeration literal has already been
1753 -- been dealt with by Resolve_Call. If the function is itself
1754 -- inherited (see 7423-001) the literal of the parent type must
1755 -- be explicitly converted to the return type of the function.
1757 if Ekind (Subp) = E_Enumeration_Literal then
1758 if Base_Type (Etype (Subp)) /= Base_Type (Etype (N)) then
1760 (N, Convert_To (Etype (N), New_Occurrence_Of (Subp, Loc)));
1762 Rewrite (N, New_Occurrence_Of (Subp, Loc));
1763 Resolve (N, Etype (N));
1767 -- Handle case of access to protected subprogram type
1770 if Ekind (Base_Type (Etype (Prefix (Name (N))))) =
1771 E_Access_Protected_Subprogram_Type
1773 -- If this is a call through an access to protected operation,
1774 -- the prefix has the form (object'address, operation'access).
1775 -- Rewrite as a for other protected calls: the object is the
1776 -- first parameter of the list of actuals.
1783 Ptr : Node_Id := Prefix (Name (N));
1784 T : Entity_Id := Equivalent_Type (Base_Type (Etype (Ptr)));
1785 D_T : Entity_Id := Designated_Type (Base_Type (Etype (Ptr)));
1788 Obj := Make_Selected_Component (Loc,
1789 Prefix => Unchecked_Convert_To (T, Ptr),
1790 Selector_Name => New_Occurrence_Of (First_Entity (T), Loc));
1792 Nam := Make_Selected_Component (Loc,
1793 Prefix => Unchecked_Convert_To (T, Ptr),
1794 Selector_Name => New_Occurrence_Of (
1795 Next_Entity (First_Entity (T)), Loc));
1797 Nam := Make_Explicit_Dereference (Loc, Nam);
1799 if Present (Parameter_Associations (N)) then
1800 Parm := Parameter_Associations (N);
1805 Prepend (Obj, Parm);
1807 if Etype (D_T) = Standard_Void_Type then
1808 Call := Make_Procedure_Call_Statement (Loc,
1810 Parameter_Associations => Parm);
1812 Call := Make_Function_Call (Loc,
1814 Parameter_Associations => Parm);
1817 Set_First_Named_Actual (Call, First_Named_Actual (N));
1819 Set_Etype (Call, Etype (D_T));
1821 -- We do not re-analyze the call to avoid infinite recursion.
1822 -- We analyze separately the prefix and the object, and set
1823 -- the checks on the prefix that would otherwise be emitted
1824 -- when resolving a call.
1828 Apply_Access_Check (Nam);
1835 -- If this is a call to an intrinsic subprogram, then perform the
1836 -- appropriate expansion to the corresponding tree node and we
1837 -- are all done (since after that the call is gone!)
1839 if Is_Intrinsic_Subprogram (Subp) then
1840 Expand_Intrinsic_Call (N, Subp);
1844 if Ekind (Subp) = E_Function
1845 or else Ekind (Subp) = E_Procedure
1847 if Is_Inlined (Subp) then
1850 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
1853 -- Verify that the body to inline has already been seen,
1854 -- and that if the body is in the current unit the inlining
1855 -- does not occur earlier. This avoids order-of-elaboration
1856 -- problems in gigi.
1859 and then Nkind (Spec) = N_Subprogram_Declaration
1860 and then Present (Body_To_Inline (Spec))
1861 and then (In_Extended_Main_Code_Unit (N)
1862 or else In_Extended_Main_Code_Unit (Parent (N)))
1863 and then (not In_Same_Extended_Unit
1864 (Sloc (Body_To_Inline (Spec)), Loc)
1866 Earlier_In_Extended_Unit
1867 (Sloc (Body_To_Inline (Spec)), Loc))
1869 Expand_Inlined_Call (N, Subp, Orig_Subp);
1872 -- Let the back-end handle it.
1874 Add_Inlined_Body (Subp);
1876 if Front_End_Inlining
1877 and then Nkind (Spec) = N_Subprogram_Declaration
1878 and then (In_Extended_Main_Code_Unit (N))
1879 and then No (Body_To_Inline (Spec))
1880 and then not Has_Completion (Subp)
1881 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
1882 and then Ineffective_Inline_Warnings
1885 ("call cannot be inlined before body is seen?", N);
1892 -- Check for a protected subprogram. This is either an intra-object
1893 -- call, or a protected function call. Protected procedure calls are
1894 -- rewritten as entry calls and handled accordingly.
1896 Scop := Scope (Subp);
1898 if Nkind (N) /= N_Entry_Call_Statement
1899 and then Is_Protected_Type (Scop)
1901 -- If the call is an internal one, it is rewritten as a call to
1902 -- to the corresponding unprotected subprogram.
1904 Expand_Protected_Subprogram_Call (N, Subp, Scop);
1907 -- Functions returning controlled objects need special attention
1909 if Controlled_Type (Etype (Subp))
1910 and then not Is_Return_By_Reference_Type (Etype (Subp))
1912 Expand_Ctrl_Function_Call (N);
1915 -- Test for First_Optional_Parameter, and if so, truncate parameter
1916 -- list if there are optional parameters at the trailing end.
1917 -- Note we never delete procedures for call via a pointer.
1919 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
1920 and then Present (First_Optional_Parameter (Subp))
1923 Last_Keep_Arg : Node_Id;
1926 -- Last_Keep_Arg will hold the last actual that should be
1927 -- retained. If it remains empty at the end, it means that
1928 -- all parameters are optional.
1930 Last_Keep_Arg := Empty;
1932 -- Find first optional parameter, must be present since we
1933 -- checked the validity of the parameter before setting it.
1935 Formal := First_Formal (Subp);
1936 Actual := First_Actual (N);
1937 while Formal /= First_Optional_Parameter (Subp) loop
1938 Last_Keep_Arg := Actual;
1939 Next_Formal (Formal);
1940 Next_Actual (Actual);
1943 -- Now we have Formal and Actual pointing to the first
1944 -- potentially droppable argument. We can drop all the
1945 -- trailing arguments whose actual matches the default.
1946 -- Note that we know that all remaining formals have
1947 -- defaults, because we checked that this requirement
1948 -- was met before setting First_Optional_Parameter.
1950 -- We use Fully_Conformant_Expressions to check for identity
1951 -- between formals and actuals, which may miss some cases, but
1952 -- on the other hand, this is only an optimization (if we fail
1953 -- to truncate a parameter it does not affect functionality).
1954 -- So if the default is 3 and the actual is 1+2, we consider
1955 -- them unequal, which hardly seems worrisome.
1957 while Present (Formal) loop
1958 if not Fully_Conformant_Expressions
1959 (Actual, Default_Value (Formal))
1961 Last_Keep_Arg := Actual;
1964 Next_Formal (Formal);
1965 Next_Actual (Actual);
1968 -- If no arguments, delete entire list, this is the easy case
1970 if No (Last_Keep_Arg) then
1971 while Is_Non_Empty_List (Parameter_Associations (N)) loop
1972 Delete_Tree (Remove_Head (Parameter_Associations (N)));
1975 Set_Parameter_Associations (N, No_List);
1976 Set_First_Named_Actual (N, Empty);
1978 -- Case where at the last retained argument is positional. This
1979 -- is also an easy case, since the retained arguments are already
1980 -- in the right form, and we don't need to worry about the order
1981 -- of arguments that get eliminated.
1983 elsif Is_List_Member (Last_Keep_Arg) then
1984 while Present (Next (Last_Keep_Arg)) loop
1985 Delete_Tree (Remove_Next (Last_Keep_Arg));
1988 Set_First_Named_Actual (N, Empty);
1990 -- This is the annoying case where the last retained argument
1991 -- is a named parameter. Since the original arguments are not
1992 -- in declaration order, we may have to delete some fairly
1993 -- random collection of arguments.
2002 -- First step, remove all the named parameters from the
2003 -- list (they are still chained using First_Named_Actual
2004 -- and Next_Named_Actual, so we have not lost them!)
2006 Temp := First (Parameter_Associations (N));
2008 -- Case of all parameters named, remove them all
2010 if Nkind (Temp) = N_Parameter_Association then
2011 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2012 Temp := Remove_Head (Parameter_Associations (N));
2015 -- Case of mixed positional/named, remove named parameters
2018 while Nkind (Next (Temp)) /= N_Parameter_Association loop
2022 while Present (Next (Temp)) loop
2023 Junk := Remove_Next (Temp);
2027 -- Now we loop through the named parameters, till we get
2028 -- to the last one to be retained, adding them to the list.
2029 -- Note that the Next_Named_Actual list does not need to be
2030 -- touched since we are only reordering them on the actual
2031 -- parameter association list.
2033 Passoc := Parent (First_Named_Actual (N));
2035 Temp := Relocate_Node (Passoc);
2037 (Parameter_Associations (N), Temp);
2039 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
2040 Passoc := Parent (Next_Named_Actual (Passoc));
2043 Set_Next_Named_Actual (Temp, Empty);
2046 Temp := Next_Named_Actual (Passoc);
2047 exit when No (Temp);
2048 Set_Next_Named_Actual
2049 (Passoc, Next_Named_Actual (Parent (Temp)));
2059 --------------------------
2060 -- Expand_Inlined_Call --
2061 --------------------------
2063 procedure Expand_Inlined_Call
2066 Orig_Subp : Entity_Id)
2068 Loc : constant Source_Ptr := Sloc (N);
2072 Exit_Lab : Entity_Id := Empty;
2079 Orig_Bod : constant Node_Id :=
2080 Body_To_Inline (Unit_Declaration_Node (Subp));
2081 Ret_Type : Entity_Id;
2084 Temp_Typ : Entity_Id;
2086 procedure Make_Exit_Label;
2087 -- Build declaration for exit label to be used in Return statements.
2089 function Process_Formals (N : Node_Id) return Traverse_Result;
2090 -- Replace occurrence of a formal with the corresponding actual, or
2091 -- the thunk generated for it.
2093 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
2094 -- If the function body is a single expression, replace call with
2095 -- expression, else insert block appropriately.
2097 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
2098 -- If procedure body has no local variables, inline body without
2099 -- creating block, otherwise rewrite call with block.
2101 ---------------------
2102 -- Make_Exit_Label --
2103 ---------------------
2105 procedure Make_Exit_Label is
2107 -- Create exit label for subprogram, if one doesn't exist yet.
2109 if No (Exit_Lab) then
2110 Lab_Id := Make_Identifier (Loc, New_Internal_Name ('L'));
2112 Make_Defining_Identifier (Loc, Chars (Lab_Id)));
2113 Exit_Lab := Make_Label (Loc, Lab_Id);
2116 Make_Implicit_Label_Declaration (Loc,
2117 Defining_Identifier => Entity (Lab_Id),
2118 Label_Construct => Exit_Lab);
2120 end Make_Exit_Label;
2122 ---------------------
2123 -- Process_Formals --
2124 ---------------------
2126 function Process_Formals (N : Node_Id) return Traverse_Result is
2132 if Is_Entity_Name (N)
2133 and then Present (Entity (N))
2138 and then Scope (E) = Subp
2140 A := Renamed_Object (E);
2142 if Is_Entity_Name (A) then
2143 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
2145 elsif Nkind (A) = N_Defining_Identifier then
2146 Rewrite (N, New_Occurrence_Of (A, Loc));
2148 else -- numeric literal
2149 Rewrite (N, New_Copy (A));
2155 elsif Nkind (N) = N_Return_Statement then
2157 if No (Expression (N)) then
2159 Rewrite (N, Make_Goto_Statement (Loc,
2160 Name => New_Copy (Lab_Id)));
2163 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
2164 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
2166 -- function body is a single expression. No need for
2171 Num_Ret := Num_Ret + 1;
2175 -- Because of the presence of private types, the views of the
2176 -- expression and the context may be different, so place an
2177 -- unchecked conversion to the context type to avoid spurious
2178 -- errors, eg. when the expression is a numeric literal and
2179 -- the context is private. If the expression is an aggregate,
2180 -- use a qualified expression, because an aggregate is not a
2181 -- legal argument of a conversion.
2183 if Nkind (Expression (N)) = N_Aggregate
2184 or else Nkind (Expression (N)) = N_Null
2187 Make_Qualified_Expression (Sloc (N),
2188 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
2189 Expression => Relocate_Node (Expression (N)));
2192 Unchecked_Convert_To
2193 (Ret_Type, Relocate_Node (Expression (N)));
2196 if Nkind (Targ) = N_Defining_Identifier then
2198 Make_Assignment_Statement (Loc,
2199 Name => New_Occurrence_Of (Targ, Loc),
2200 Expression => Ret));
2203 Make_Assignment_Statement (Loc,
2204 Name => New_Copy (Targ),
2205 Expression => Ret));
2208 Set_Assignment_OK (Name (N));
2210 if Present (Exit_Lab) then
2212 Make_Goto_Statement (Loc,
2213 Name => New_Copy (Lab_Id)));
2222 end Process_Formals;
2224 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
2226 ---------------------------
2227 -- Rewrite_Function_Call --
2228 ---------------------------
2230 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
2231 HSS : Node_Id := Handled_Statement_Sequence (Blk);
2232 Fst : Node_Id := First (Statements (HSS));
2236 -- Optimize simple case: function body is a single return statement,
2237 -- which has been expanded into an assignment.
2239 if Is_Empty_List (Declarations (Blk))
2240 and then Nkind (Fst) = N_Assignment_Statement
2241 and then No (Next (Fst))
2244 -- The function call may have been rewritten as the temporary
2245 -- that holds the result of the call, in which case remove the
2246 -- now useless declaration.
2248 if Nkind (N) = N_Identifier
2249 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2251 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
2254 Rewrite (N, Expression (Fst));
2256 elsif Nkind (N) = N_Identifier
2257 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2260 -- The block assigns the result of the call to the temporary.
2262 Insert_After (Parent (Entity (N)), Blk);
2264 elsif Nkind (Parent (N)) = N_Assignment_Statement
2265 and then Is_Entity_Name (Name (Parent (N)))
2268 -- replace assignment with the block.
2270 Rewrite (Parent (N), Blk);
2272 elsif Nkind (Parent (N)) = N_Object_Declaration then
2273 Set_Expression (Parent (N), Empty);
2274 Insert_After (Parent (N), Blk);
2276 end Rewrite_Function_Call;
2278 ----------------------------
2279 -- Rewrite_Procedure_Call --
2280 ----------------------------
2282 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
2283 HSS : Node_Id := Handled_Statement_Sequence (Blk);
2286 if Is_Empty_List (Declarations (Blk)) then
2287 Insert_List_After (N, Statements (HSS));
2288 Rewrite (N, Make_Null_Statement (Loc));
2292 end Rewrite_Procedure_Call;
2294 -- Start of processing for Expand_Inlined_Call
2297 if Nkind (Orig_Bod) = N_Defining_Identifier then
2299 -- Subprogram is a renaming_as_body. Calls appearing after the
2300 -- renaming can be replaced with calls to the renamed entity
2301 -- directly, because the subprograms are subtype conformant.
2303 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
2307 -- Use generic machinery to copy body of inlined subprogram, as if it
2308 -- were an instantiation, resetting source locations appropriately, so
2309 -- that nested inlined calls appear in the main unit.
2311 Save_Env (Subp, Empty);
2312 Set_Copied_Sloc (N, Defining_Entity (Orig_Bod));
2315 Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
2318 Make_Block_Statement (Loc,
2319 Declarations => Declarations (Bod),
2320 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
2322 if No (Declarations (Bod)) then
2323 Set_Declarations (Blk, New_List);
2326 -- If this is a derived function, establish the proper return type.
2328 if Present (Orig_Subp)
2329 and then Orig_Subp /= Subp
2331 Ret_Type := Etype (Orig_Subp);
2333 Ret_Type := Etype (Subp);
2336 F := First_Formal (Subp);
2337 A := First_Actual (N);
2339 -- Create temporaries for the actuals that are expressions, or that
2340 -- are scalars and require copying to preserve semantics.
2342 while Present (F) loop
2344 if Present (Renamed_Object (F)) then
2345 Error_Msg_N (" cannot inline call to recursive subprogram", N);
2349 -- If the argument may be a controlling argument in a call within
2350 -- the inlined body, we must preserve its classwide nature to
2351 -- insure that dynamic dispatching take place subsequently.
2352 -- If the formal has a constraint it must be preserved to retain
2353 -- the semantics of the body.
2355 if Is_Class_Wide_Type (Etype (F))
2356 or else (Is_Access_Type (Etype (F))
2358 Is_Class_Wide_Type (Designated_Type (Etype (F))))
2360 Temp_Typ := Etype (F);
2362 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
2363 and then Etype (F) /= Base_Type (Etype (F))
2365 Temp_Typ := Etype (F);
2368 Temp_Typ := Etype (A);
2371 if (not Is_Entity_Name (A)
2372 and then Nkind (A) /= N_Integer_Literal
2373 and then Nkind (A) /= N_Real_Literal)
2375 or else Is_Scalar_Type (Etype (A))
2378 Make_Defining_Identifier (Loc,
2379 Chars => New_Internal_Name ('C'));
2381 -- If the actual for an in/in-out parameter is a view conversion,
2382 -- make it into an unchecked conversion, given that an untagged
2383 -- type conversion is not a proper object for a renaming.
2384 -- In-out conversions that involve real conversions have already
2385 -- been transformed in Expand_Actuals.
2387 if Nkind (A) = N_Type_Conversion
2389 (Ekind (F) = E_In_Out_Parameter
2390 or else not Is_Tagged_Type (Etype (F)))
2392 New_A := Make_Unchecked_Type_Conversion (Loc,
2393 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
2394 Expression => Relocate_Node (Expression (A)));
2396 elsif Etype (F) /= Etype (A) then
2397 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
2398 Temp_Typ := Etype (F);
2401 New_A := Relocate_Node (A);
2404 Set_Sloc (New_A, Sloc (N));
2406 if Ekind (F) = E_In_Parameter
2407 and then not Is_Limited_Type (Etype (A))
2410 Make_Object_Declaration (Loc,
2411 Defining_Identifier => Temp,
2412 Constant_Present => True,
2413 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
2414 Expression => New_A);
2417 Make_Object_Renaming_Declaration (Loc,
2418 Defining_Identifier => Temp,
2419 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
2423 Prepend (Decl, Declarations (Blk));
2424 Set_Renamed_Object (F, Temp);
2427 if Etype (F) /= Etype (A) then
2429 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
2431 Set_Renamed_Object (F, A);
2439 -- Establish target of function call. If context is not assignment or
2440 -- declaration, create a temporary as a target. The declaration for
2441 -- the temporary may be subsequently optimized away if the body is a
2442 -- single expression, or if the left-hand side of the assignment is
2445 if Ekind (Subp) = E_Function then
2446 if Nkind (Parent (N)) = N_Assignment_Statement
2447 and then Is_Entity_Name (Name (Parent (N)))
2449 Targ := Name (Parent (N));
2452 -- Replace call with temporary, and create its declaration.
2455 Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
2458 Make_Object_Declaration (Loc,
2459 Defining_Identifier => Temp,
2460 Object_Definition =>
2461 New_Occurrence_Of (Ret_Type, Loc));
2463 Set_No_Initialization (Decl);
2464 Insert_Action (N, Decl);
2465 Rewrite (N, New_Occurrence_Of (Temp, Loc));
2470 -- Traverse the tree and replace formals with actuals or their thunks.
2471 -- Attach block to tree before analysis and rewriting.
2473 Replace_Formals (Blk);
2474 Set_Parent (Blk, N);
2476 if Present (Exit_Lab) then
2478 -- If the body was a single expression, the single return statement
2479 -- and the corresponding label are useless.
2483 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
2486 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
2488 Append (Lab_Decl, (Declarations (Blk)));
2489 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
2493 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
2494 -- conflicting private views that Gigi would ignore.
2497 I_Flag : constant Boolean := In_Inlined_Body;
2500 In_Inlined_Body := True;
2502 In_Inlined_Body := I_Flag;
2505 if Ekind (Subp) = E_Procedure then
2506 Rewrite_Procedure_Call (N, Blk);
2508 Rewrite_Function_Call (N, Blk);
2513 -- Cleanup mapping between formals and actuals, for other expansions.
2515 F := First_Formal (Subp);
2517 while Present (F) loop
2518 Set_Renamed_Object (F, Empty);
2521 end Expand_Inlined_Call;
2523 ----------------------------
2524 -- Expand_N_Function_Call --
2525 ----------------------------
2527 procedure Expand_N_Function_Call (N : Node_Id) is
2528 Typ : constant Entity_Id := Etype (N);
2530 function Returned_By_Reference return Boolean;
2531 -- If the return type is returned through the secondary stack. i.e.
2532 -- by reference, we don't want to create a temporary to force stack
2535 function Returned_By_Reference return Boolean is
2536 S : Entity_Id := Current_Scope;
2539 if Is_Return_By_Reference_Type (Typ) then
2542 elsif Nkind (Parent (N)) /= N_Return_Statement then
2545 elsif Requires_Transient_Scope (Typ) then
2547 -- Verify that the return type of the enclosing function has
2548 -- the same constrained status as that of the expression.
2550 while Ekind (S) /= E_Function loop
2554 return Is_Constrained (Typ) = Is_Constrained (Etype (S));
2558 end Returned_By_Reference;
2560 -- Start of processing for Expand_N_Function_Call
2563 -- A special check. If stack checking is enabled, and the return type
2564 -- might generate a large temporary, and the call is not the right
2565 -- side of an assignment, then generate an explicit temporary. We do
2566 -- this because otherwise gigi may generate a large temporary on the
2567 -- fly and this can cause trouble with stack checking.
2569 if May_Generate_Large_Temp (Typ)
2570 and then Nkind (Parent (N)) /= N_Assignment_Statement
2572 (Nkind (Parent (N)) /= N_Object_Declaration
2573 or else Expression (Parent (N)) /= N)
2574 and then not Returned_By_Reference
2576 -- Note: it might be thought that it would be OK to use a call to
2577 -- Force_Evaluation here, but that's not good enough, because that
2578 -- results in a 'Reference construct that may still need a temporary.
2581 Loc : constant Source_Ptr := Sloc (N);
2582 Temp_Obj : constant Entity_Id := Make_Defining_Identifier (Loc,
2583 New_Internal_Name ('F'));
2584 Temp_Typ : Entity_Id := Typ;
2591 if Is_Tagged_Type (Typ)
2592 and then Present (Controlling_Argument (N))
2594 if Nkind (Parent (N)) /= N_Procedure_Call_Statement
2595 and then Nkind (Parent (N)) /= N_Function_Call
2597 -- If this is a tag-indeterminate call, the object must
2600 if Is_Tag_Indeterminate (N) then
2601 Temp_Typ := Class_Wide_Type (Typ);
2605 -- If this is a dispatching call that is itself the
2606 -- controlling argument of an enclosing call, the nominal
2607 -- subtype of the object that replaces it must be classwide,
2608 -- so that dispatching will take place properly. If it is
2609 -- not a controlling argument, the object is not classwide.
2611 Proc := Entity (Name (Parent (N)));
2612 F := First_Formal (Proc);
2613 A := First_Actual (Parent (N));
2620 if Is_Controlling_Formal (F) then
2621 Temp_Typ := Class_Wide_Type (Typ);
2627 Make_Object_Declaration (Loc,
2628 Defining_Identifier => Temp_Obj,
2629 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
2630 Constant_Present => True,
2631 Expression => Relocate_Node (N));
2632 Set_Assignment_OK (Decl);
2634 Insert_Actions (N, New_List (Decl));
2635 Rewrite (N, New_Occurrence_Of (Temp_Obj, Loc));
2638 -- Normal case, expand the call
2643 end Expand_N_Function_Call;
2645 ---------------------------------------
2646 -- Expand_N_Procedure_Call_Statement --
2647 ---------------------------------------
2649 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
2652 end Expand_N_Procedure_Call_Statement;
2654 ------------------------------
2655 -- Expand_N_Subprogram_Body --
2656 ------------------------------
2658 -- Add poll call if ATC polling is enabled
2660 -- Add return statement if last statement in body is not a return
2661 -- statement (this makes things easier on Gigi which does not want
2662 -- to have to handle a missing return).
2664 -- Add call to Activate_Tasks if body is a task activator
2666 -- Deal with possible detection of infinite recursion
2668 -- Eliminate body completely if convention stubbed
2670 -- Encode entity names within body, since we will not need to reference
2671 -- these entities any longer in the front end.
2673 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
2675 -- Reset Pure indication if any parameter has root type System.Address
2677 procedure Expand_N_Subprogram_Body (N : Node_Id) is
2678 Loc : constant Source_Ptr := Sloc (N);
2679 H : constant Node_Id := Handled_Statement_Sequence (N);
2680 Body_Id : Entity_Id;
2681 Spec_Id : Entity_Id;
2688 procedure Add_Return (S : List_Id);
2689 -- Append a return statement to the statement sequence S if the last
2690 -- statement is not already a return or a goto statement. Note that
2691 -- the latter test is not critical, it does not matter if we add a
2692 -- few extra returns, since they get eliminated anyway later on.
2698 procedure Add_Return (S : List_Id) is
2699 Last_S : constant Node_Id := Last (S);
2700 -- Get original node, in case raise has been rewritten
2703 if not Is_Transfer (Last_S) then
2704 Append_To (S, Make_Return_Statement (Sloc (Last_S)));
2708 -- Start of processing for Expand_N_Subprogram_Body
2711 -- Set L to either the list of declarations if present, or
2712 -- to the list of statements if no declarations are present.
2713 -- This is used to insert new stuff at the start.
2715 if Is_Non_Empty_List (Declarations (N)) then
2716 L := Declarations (N);
2718 L := Statements (Handled_Statement_Sequence (N));
2721 -- Need poll on entry to subprogram if polling enabled. We only
2722 -- do this for non-empty subprograms, since it does not seem
2723 -- necessary to poll for a dummy null subprogram.
2725 if Is_Non_Empty_List (L) then
2726 Generate_Poll_Call (First (L));
2729 -- Find entity for subprogram
2731 Body_Id := Defining_Entity (N);
2733 if Present (Corresponding_Spec (N)) then
2734 Spec_Id := Corresponding_Spec (N);
2739 -- If this is a Pure function which has any parameters whose root
2740 -- type is System.Address, reset the Pure indication, since it will
2741 -- likely cause incorrect code to be generated.
2743 if Is_Pure (Spec_Id)
2744 and then Is_Subprogram (Spec_Id)
2745 and then not Has_Pragma_Pure_Function (Spec_Id)
2748 F : Entity_Id := First_Formal (Spec_Id);
2751 while Present (F) loop
2752 if Is_RTE (Root_Type (Etype (F)), RE_Address) then
2753 Set_Is_Pure (Spec_Id, False);
2755 if Spec_Id /= Body_Id then
2756 Set_Is_Pure (Body_Id, False);
2767 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
2769 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
2771 F : Entity_Id := First_Formal (Spec_Id);
2772 V : constant Boolean := Validity_Checks_On;
2775 -- We turn off validity checking, since we do not want any
2776 -- check on the initializing value itself (which we know
2777 -- may well be invalid!)
2779 Validity_Checks_On := False;
2781 -- Loop through formals
2783 while Present (F) loop
2784 if Is_Scalar_Type (Etype (F))
2785 and then Ekind (F) = E_Out_Parameter
2787 Insert_Before_And_Analyze (First (L),
2788 Make_Assignment_Statement (Loc,
2789 Name => New_Occurrence_Of (F, Loc),
2790 Expression => Get_Simple_Init_Val (Etype (F), Loc)));
2796 Validity_Checks_On := V;
2800 -- Clear out statement list for stubbed procedure
2802 if Present (Corresponding_Spec (N)) then
2803 Set_Elaboration_Flag (N, Spec_Id);
2805 if Convention (Spec_Id) = Convention_Stubbed
2806 or else Is_Eliminated (Spec_Id)
2808 Set_Declarations (N, Empty_List);
2809 Set_Handled_Statement_Sequence (N,
2810 Make_Handled_Sequence_Of_Statements (Loc,
2811 Statements => New_List (
2812 Make_Null_Statement (Loc))));
2817 Scop := Scope (Spec_Id);
2819 -- Returns_By_Ref flag is normally set when the subprogram is frozen
2820 -- but subprograms with no specs are not frozen
2823 Typ : constant Entity_Id := Etype (Spec_Id);
2824 Utyp : constant Entity_Id := Underlying_Type (Typ);
2827 if not Acts_As_Spec (N)
2828 and then Nkind (Parent (Parent (Spec_Id))) /=
2829 N_Subprogram_Body_Stub
2833 elsif Is_Return_By_Reference_Type (Typ) then
2834 Set_Returns_By_Ref (Spec_Id);
2836 elsif Present (Utyp) and then Controlled_Type (Utyp) then
2837 Set_Returns_By_Ref (Spec_Id);
2841 -- For a procedure, we add a return for all possible syntactic ends
2842 -- of the subprogram. Note that reanalysis is not necessary in this
2843 -- case since it would require a lot of work and accomplish nothing.
2845 if Ekind (Spec_Id) = E_Procedure
2846 or else Ekind (Spec_Id) = E_Generic_Procedure
2848 Add_Return (Statements (H));
2850 if Present (Exception_Handlers (H)) then
2851 Except_H := First_Non_Pragma (Exception_Handlers (H));
2853 while Present (Except_H) loop
2854 Add_Return (Statements (Except_H));
2855 Next_Non_Pragma (Except_H);
2859 -- For a function, we must deal with the case where there is at
2860 -- least one missing return. What we do is to wrap the entire body
2861 -- of the function in a block:
2874 -- raise Program_Error;
2877 -- This approach is necessary because the raise must be signalled
2878 -- to the caller, not handled by any local handler (RM 6.4(11)).
2880 -- Note: we do not need to analyze the constructed sequence here,
2881 -- since it has no handler, and an attempt to analyze the handled
2882 -- statement sequence twice is risky in various ways (e.g. the
2883 -- issue of expanding cleanup actions twice).
2885 elsif Has_Missing_Return (Spec_Id) then
2887 Hloc : constant Source_Ptr := Sloc (H);
2888 Blok : constant Node_Id :=
2889 Make_Block_Statement (Hloc,
2890 Handled_Statement_Sequence => H);
2891 Rais : constant Node_Id :=
2892 Make_Raise_Program_Error (Hloc,
2893 Reason => PE_Missing_Return);
2896 Set_Handled_Statement_Sequence (N,
2897 Make_Handled_Sequence_Of_Statements (Hloc,
2898 Statements => New_List (Blok, Rais)));
2900 New_Scope (Spec_Id);
2907 -- Add discriminal renamings to protected subprograms.
2908 -- Install new discriminals for expansion of the next
2909 -- subprogram of this protected type, if any.
2911 if Is_List_Member (N)
2912 and then Present (Parent (List_Containing (N)))
2913 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
2915 Add_Discriminal_Declarations
2916 (Declarations (N), Scop, Name_uObject, Loc);
2917 Add_Private_Declarations (Declarations (N), Scop, Name_uObject, Loc);
2919 -- Associate privals and discriminals with the next protected
2920 -- operation body to be expanded. These are used to expand
2921 -- references to private data objects and discriminants,
2924 Next_Op := Next_Protected_Operation (N);
2926 if Present (Next_Op) then
2927 Dec := Parent (Base_Type (Scop));
2928 Set_Privals (Dec, Next_Op, Loc);
2929 Set_Discriminals (Dec);
2933 -- If subprogram contains a parameterless recursive call, then we may
2934 -- have an infinite recursion, so see if we can generate code to check
2935 -- for this possibility if storage checks are not suppressed.
2937 if Ekind (Spec_Id) = E_Procedure
2938 and then Has_Recursive_Call (Spec_Id)
2939 and then not Storage_Checks_Suppressed (Spec_Id)
2941 Detect_Infinite_Recursion (N, Spec_Id);
2944 -- Finally, if we are in Normalize_Scalars mode, then any scalar out
2945 -- parameters must be initialized to the appropriate default value.
2947 if Ekind (Spec_Id) = E_Procedure and then Normalize_Scalars then
2954 Formal := First_Formal (Spec_Id);
2956 while Present (Formal) loop
2957 Floc := Sloc (Formal);
2959 if Ekind (Formal) = E_Out_Parameter
2960 and then Is_Scalar_Type (Etype (Formal))
2963 Make_Assignment_Statement (Floc,
2964 Name => New_Occurrence_Of (Formal, Floc),
2966 Get_Simple_Init_Val (Etype (Formal), Floc));
2967 Prepend (Stm, Declarations (N));
2971 Next_Formal (Formal);
2976 -- If the subprogram does not have pending instantiations, then we
2977 -- must generate the subprogram descriptor now, since the code for
2978 -- the subprogram is complete, and this is our last chance. However
2979 -- if there are pending instantiations, then the code is not
2980 -- complete, and we will delay the generation.
2982 if Is_Subprogram (Spec_Id)
2983 and then not Delay_Subprogram_Descriptors (Spec_Id)
2985 Generate_Subprogram_Descriptor_For_Subprogram (N, Spec_Id);
2988 -- Set to encode entity names in package body before gigi is called
2990 Qualify_Entity_Names (N);
2991 end Expand_N_Subprogram_Body;
2993 -----------------------------------
2994 -- Expand_N_Subprogram_Body_Stub --
2995 -----------------------------------
2997 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
2999 if Present (Corresponding_Body (N)) then
3000 Expand_N_Subprogram_Body (
3001 Unit_Declaration_Node (Corresponding_Body (N)));
3004 end Expand_N_Subprogram_Body_Stub;
3006 -------------------------------------
3007 -- Expand_N_Subprogram_Declaration --
3008 -------------------------------------
3010 -- The first task to be performed is the construction of default
3011 -- expression functions for in parameters with default values. These
3012 -- are parameterless inlined functions that are used to evaluate
3013 -- default expressions that are more complicated than simple literals
3014 -- or identifiers referencing constants and variables.
3016 -- If the declaration appears within a protected body, it is a private
3017 -- operation of the protected type. We must create the corresponding
3018 -- protected subprogram an associated formals. For a normal protected
3019 -- operation, this is done when expanding the protected type declaration.
3021 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
3022 Loc : constant Source_Ptr := Sloc (N);
3023 Subp : Entity_Id := Defining_Entity (N);
3024 Scop : Entity_Id := Scope (Subp);
3025 Prot_Sub : Entity_Id;
3029 -- Deal with case of protected subprogram
3031 if Is_List_Member (N)
3032 and then Present (Parent (List_Containing (N)))
3033 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
3034 and then Is_Protected_Type (Scop)
3036 if No (Protected_Body_Subprogram (Subp)) then
3038 Make_Subprogram_Declaration (Loc,
3040 Build_Protected_Sub_Specification
3041 (N, Scop, Unprotected => True));
3043 -- The protected subprogram is declared outside of the protected
3044 -- body. Given that the body has frozen all entities so far, we
3045 -- freeze the subprogram explicitly. If the body is a subunit,
3046 -- the insertion point is before the stub in the parent.
3048 Prot_Bod := Parent (List_Containing (N));
3050 if Nkind (Parent (Prot_Bod)) = N_Subunit then
3051 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
3054 Insert_Before (Prot_Bod, Prot_Sub);
3056 New_Scope (Scope (Scop));
3058 Set_Protected_Body_Subprogram (Subp,
3059 Defining_Unit_Name (Specification (Prot_Sub)));
3063 end Expand_N_Subprogram_Declaration;
3065 ---------------------------------------
3066 -- Expand_Protected_Object_Reference --
3067 ---------------------------------------
3069 function Expand_Protected_Object_Reference
3074 Loc : constant Source_Ptr := Sloc (N);
3081 Rec := Make_Identifier (Loc, Name_uObject);
3082 Set_Etype (Rec, Corresponding_Record_Type (Scop));
3084 -- Find enclosing protected operation, and retrieve its first
3085 -- parameter, which denotes the enclosing protected object.
3086 -- If the enclosing operation is an entry, we are immediately
3087 -- within the protected body, and we can retrieve the object
3088 -- from the service entries procedure. A barrier function has
3089 -- has the same signature as an entry. A barrier function is
3090 -- compiled within the protected object, but unlike protected
3091 -- operations its never needs locks, so that its protected body
3092 -- subprogram points to itself.
3094 Proc := Current_Scope;
3096 while Present (Proc)
3097 and then Scope (Proc) /= Scop
3099 Proc := Scope (Proc);
3102 Corr := Protected_Body_Subprogram (Proc);
3106 -- Previous error left expansion incomplete.
3107 -- Nothing to do on this call.
3114 (First (Parameter_Specifications (Parent (Corr))));
3116 if Is_Subprogram (Proc)
3117 and then Proc /= Corr
3119 -- Protected function or procedure.
3121 Set_Entity (Rec, Param);
3123 -- Rec is a reference to an entity which will not be in scope
3124 -- when the call is reanalyzed, and needs no further analysis.
3129 -- Entry or barrier function for entry body.
3130 -- The first parameter of the entry body procedure is a
3131 -- pointer to the object. We create a local variable
3132 -- of the proper type, duplicating what is done to define
3133 -- _object later on.
3137 Obj_Ptr : Entity_Id := Make_Defining_Identifier
3138 (Loc, New_Internal_Name ('T'));
3141 Make_Full_Type_Declaration (Loc,
3142 Defining_Identifier => Obj_Ptr,
3144 Make_Access_To_Object_Definition (Loc,
3145 Subtype_Indication =>
3147 (Corresponding_Record_Type (Scop), Loc))));
3149 Insert_Actions (N, Decls);
3150 Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
3153 Make_Explicit_Dereference (Loc,
3154 Unchecked_Convert_To (Obj_Ptr,
3155 New_Occurrence_Of (Param, Loc)));
3157 -- Analyze new actual. Other actuals in calls are already
3158 -- analyzed and the list of actuals is not renalyzed after
3161 Set_Parent (Rec, N);
3167 end Expand_Protected_Object_Reference;
3169 --------------------------------------
3170 -- Expand_Protected_Subprogram_Call --
3171 --------------------------------------
3173 procedure Expand_Protected_Subprogram_Call
3181 -- If the protected object is not an enclosing scope, this is
3182 -- an inter-object function call. Inter-object procedure
3183 -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
3184 -- The call is intra-object only if the subprogram being
3185 -- called is in the protected body being compiled, and if the
3186 -- protected object in the call is statically the enclosing type.
3187 -- The object may be an component of some other data structure,
3188 -- in which case this must be handled as an inter-object call.
3190 if not In_Open_Scopes (Scop)
3191 or else not Is_Entity_Name (Name (N))
3193 if Nkind (Name (N)) = N_Selected_Component then
3194 Rec := Prefix (Name (N));
3197 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
3198 Rec := Prefix (Prefix (Name (N)));
3201 Build_Protected_Subprogram_Call (N,
3202 Name => New_Occurrence_Of (Subp, Sloc (N)),
3203 Rec => Convert_Concurrent (Rec, Etype (Rec)),
3207 Rec := Expand_Protected_Object_Reference (N, Scop);
3213 Build_Protected_Subprogram_Call (N,
3222 -- If it is a function call it can appear in elaboration code and
3223 -- the called entity must be frozen here.
3225 if Ekind (Subp) = E_Function then
3226 Freeze_Expression (Name (N));
3228 end Expand_Protected_Subprogram_Call;
3230 -----------------------
3231 -- Freeze_Subprogram --
3232 -----------------------
3234 procedure Freeze_Subprogram (N : Node_Id) is
3235 E : constant Entity_Id := Entity (N);
3238 -- When a primitive is frozen, enter its name in the corresponding
3239 -- dispatch table. If the DTC_Entity field is not set this is an
3240 -- overridden primitive that can be ignored. We suppress the
3241 -- initialization of the dispatch table entry when Java_VM because
3242 -- the dispatching mechanism is handled internally by the JVM.
3244 if Is_Dispatching_Operation (E)
3245 and then not Is_Abstract (E)
3246 and then Present (DTC_Entity (E))
3247 and then not Is_CPP_Class (Scope (DTC_Entity (E)))
3248 and then not Java_VM
3250 Check_Overriding_Operation (E);
3251 Insert_After (N, Fill_DT_Entry (Sloc (N), E));
3254 -- Mark functions that return by reference. Note that it cannot be
3255 -- part of the normal semantic analysis of the spec since the
3256 -- underlying returned type may not be known yet (for private types)
3259 Typ : constant Entity_Id := Etype (E);
3260 Utyp : constant Entity_Id := Underlying_Type (Typ);
3263 if Is_Return_By_Reference_Type (Typ) then
3264 Set_Returns_By_Ref (E);
3266 elsif Present (Utyp) and then Controlled_Type (Utyp) then
3267 Set_Returns_By_Ref (E);
3271 end Freeze_Subprogram;
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