1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2001, 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)),
469 Else_Statements => New_List (
470 Relocate_Node (Node (Call)))));
472 Analyze (Node (Call));
477 -- Remove temporary scope stack entry used for analysis
480 end Detect_Infinite_Recursion;
486 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id) is
487 Loc : constant Source_Ptr := Sloc (N);
492 E_Formal : Entity_Id;
494 procedure Add_Call_By_Copy_Code;
495 -- For In and In-Out parameters, where the parameter must be passed
496 -- by copy, this routine generates a temporary variable into which
497 -- the actual is copied, and then passes this as the parameter. This
498 -- routine also takes care of any constraint checks required for the
499 -- type conversion case (on both the way in and the way out).
501 procedure Add_Packed_Call_By_Copy_Code;
502 -- This is used when the actual involves a reference to an element
503 -- of a packed array, where we can appropriately use a simpler
504 -- approach than the full call by copy code. We just copy the value
505 -- in and out of an apropriate temporary.
507 procedure Check_Fortran_Logical;
508 -- A value of type Logical that is passed through a formal parameter
509 -- must be normalized because .TRUE. usually does not have the same
510 -- representation as True. We assume that .FALSE. = False = 0.
511 -- What about functions that return a logical type ???
513 function Make_Var (Actual : Node_Id) return Entity_Id;
514 -- Returns an entity that refers to the given actual parameter,
515 -- Actual (not including any type conversion). If Actual is an
516 -- entity name, then this entity is returned unchanged, otherwise
517 -- a renaming is created to provide an entity for the actual.
519 procedure Reset_Packed_Prefix;
520 -- The expansion of a packed array component reference is delayed in
521 -- the context of a call. Now we need to complete the expansion, so we
522 -- unmark the analyzed bits in all prefixes.
524 ---------------------------
525 -- Add_Call_By_Copy_Code --
526 ---------------------------
528 procedure Add_Call_By_Copy_Code is
537 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
539 if Nkind (Actual) = N_Type_Conversion then
540 V_Typ := Etype (Expression (Actual));
541 Var := Make_Var (Expression (Actual));
542 Crep := not Same_Representation
543 (Etype (Formal), Etype (Expression (Actual)));
545 V_Typ := Etype (Actual);
546 Var := Make_Var (Actual);
550 -- Setup initialization for case of in out parameter, or an out
551 -- parameter where the formal is an unconstrained array (in the
552 -- latter case, we have to pass in an object with bounds).
554 if Ekind (Formal) = E_In_Out_Parameter
555 or else (Is_Array_Type (Etype (Formal))
557 not Is_Constrained (Etype (Formal)))
559 if Nkind (Actual) = N_Type_Conversion then
560 if Conversion_OK (Actual) then
561 Init := OK_Convert_To
562 (Etype (Formal), New_Occurrence_Of (Var, Loc));
565 (Etype (Formal), New_Occurrence_Of (Var, Loc));
568 Init := New_Occurrence_Of (Var, Loc);
571 -- An initialization is created for packed conversions as
572 -- actuals for out parameters to enable Make_Object_Declaration
573 -- to determine the proper subtype for N_Node. Note that this
574 -- is wasteful because the extra copying on the call side is
575 -- not required for such out parameters. ???
577 elsif Ekind (Formal) = E_Out_Parameter
578 and then Nkind (Actual) = N_Type_Conversion
579 and then (Is_Bit_Packed_Array (Etype (Formal))
581 Is_Bit_Packed_Array (Etype (Expression (Actual))))
583 if Conversion_OK (Actual) then
585 OK_Convert_To (Etype (Formal), New_Occurrence_Of (Var, Loc));
588 Convert_To (Etype (Formal), New_Occurrence_Of (Var, Loc));
595 Make_Object_Declaration (Loc,
596 Defining_Identifier => Temp,
598 New_Occurrence_Of (Etype (Formal), Loc),
600 Set_Assignment_OK (N_Node);
601 Insert_Action (N, N_Node);
603 -- Now, normally the deal here is that we use the defining
604 -- identifier created by that object declaration. There is
605 -- one exception to this. In the change of representation case
606 -- the above declaration will end up looking like:
608 -- temp : type := identifier;
610 -- And in this case we might as well use the identifier directly
611 -- and eliminate the temporary. Note that the analysis of the
612 -- declaration was not a waste of time in that case, since it is
613 -- what generated the necessary change of representation code. If
614 -- the change of representation introduced additional code, as in
615 -- a fixed-integer conversion, the expression is not an identifier
619 and then Present (Expression (N_Node))
620 and then Is_Entity_Name (Expression (N_Node))
622 Temp := Entity (Expression (N_Node));
623 Rewrite (N_Node, Make_Null_Statement (Loc));
626 -- If type conversion, use reverse conversion on exit
628 if Nkind (Actual) = N_Type_Conversion then
629 if Conversion_OK (Actual) then
630 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
632 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
635 Expr := New_Occurrence_Of (Temp, Loc);
638 Rewrite (Actual, New_Reference_To (Temp, Loc));
641 Append_To (Post_Call,
642 Make_Assignment_Statement (Loc,
643 Name => New_Occurrence_Of (Var, Loc),
644 Expression => Expr));
646 Set_Assignment_OK (Name (Last (Post_Call)));
647 end Add_Call_By_Copy_Code;
649 ----------------------------------
650 -- Add_Packed_Call_By_Copy_Code --
651 ----------------------------------
653 procedure Add_Packed_Call_By_Copy_Code is
663 -- Prepare to generate code
665 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
666 Incod := Relocate_Node (Actual);
667 Outcod := New_Copy_Tree (Incod);
669 -- Generate declaration of temporary variable, initializing it
670 -- with the input parameter unless we have an OUT variable.
672 if Ekind (Formal) = E_Out_Parameter then
677 Make_Object_Declaration (Loc,
678 Defining_Identifier => Temp,
680 New_Occurrence_Of (Etype (Formal), Loc),
681 Expression => Incod));
683 -- The actual is simply a reference to the temporary
685 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
687 -- Generate copy out if OUT or IN OUT parameter
689 if Ekind (Formal) /= E_In_Parameter then
691 Rhs := New_Occurrence_Of (Temp, Loc);
693 -- Deal with conversion
695 if Nkind (Lhs) = N_Type_Conversion then
696 Lhs := Expression (Lhs);
697 Rhs := Convert_To (Etype (Actual), Rhs);
700 Append_To (Post_Call,
701 Make_Assignment_Statement (Loc,
705 end Add_Packed_Call_By_Copy_Code;
707 ---------------------------
708 -- Check_Fortran_Logical --
709 ---------------------------
711 procedure Check_Fortran_Logical is
712 Logical : Entity_Id := Etype (Formal);
715 -- Note: this is very incomplete, e.g. it does not handle arrays
716 -- of logical values. This is really not the right approach at all???)
719 if Convention (Subp) = Convention_Fortran
720 and then Root_Type (Etype (Formal)) = Standard_Boolean
721 and then Ekind (Formal) /= E_In_Parameter
723 Var := Make_Var (Actual);
724 Append_To (Post_Call,
725 Make_Assignment_Statement (Loc,
726 Name => New_Occurrence_Of (Var, Loc),
728 Unchecked_Convert_To (
731 Left_Opnd => New_Occurrence_Of (Var, Loc),
733 Unchecked_Convert_To (
735 New_Occurrence_Of (Standard_False, Loc))))));
737 end Check_Fortran_Logical;
743 function Make_Var (Actual : Node_Id) return Entity_Id is
747 if Is_Entity_Name (Actual) then
748 return Entity (Actual);
751 Var := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
754 Make_Object_Renaming_Declaration (Loc,
755 Defining_Identifier => Var,
757 New_Occurrence_Of (Etype (Actual), Loc),
758 Name => Relocate_Node (Actual));
760 Insert_Action (N, N_Node);
765 -------------------------
766 -- Reset_Packed_Prefix --
767 -------------------------
769 procedure Reset_Packed_Prefix is
770 Pfx : Node_Id := Actual;
774 Set_Analyzed (Pfx, False);
775 exit when Nkind (Pfx) /= N_Selected_Component
776 and then Nkind (Pfx) /= N_Indexed_Component;
779 end Reset_Packed_Prefix;
781 -- Start of processing for Expand_Actuals
784 Formal := First_Formal (Subp);
785 Actual := First_Actual (N);
787 Post_Call := New_List;
789 while Present (Formal) loop
790 E_Formal := Etype (Formal);
792 if Is_Scalar_Type (E_Formal)
793 or else Nkind (Actual) = N_Slice
795 Check_Fortran_Logical;
799 elsif Ekind (Formal) /= E_Out_Parameter then
801 -- The unusual case of the current instance of a protected type
802 -- requires special handling. This can only occur in the context
803 -- of a call within the body of a protected operation.
805 if Is_Entity_Name (Actual)
806 and then Ekind (Entity (Actual)) = E_Protected_Type
807 and then In_Open_Scopes (Entity (Actual))
809 if Scope (Subp) /= Entity (Actual) then
810 Error_Msg_N ("operation outside protected type may not "
811 & "call back its protected operations?", Actual);
815 Expand_Protected_Object_Reference (N, Entity (Actual)));
818 Apply_Constraint_Check (Actual, E_Formal);
820 -- Out parameter case. No constraint checks on access type
823 elsif Is_Access_Type (E_Formal) then
828 elsif Has_Discriminants (Base_Type (E_Formal))
829 or else Has_Non_Null_Base_Init_Proc (E_Formal)
831 Apply_Constraint_Check (Actual, E_Formal);
836 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
839 -- Processing for IN-OUT and OUT parameters
841 if Ekind (Formal) /= E_In_Parameter then
843 -- For type conversions of arrays, apply length/range checks
845 if Is_Array_Type (E_Formal)
846 and then Nkind (Actual) = N_Type_Conversion
848 if Is_Constrained (E_Formal) then
849 Apply_Length_Check (Expression (Actual), E_Formal);
851 Apply_Range_Check (Expression (Actual), E_Formal);
855 -- If argument is a type conversion for a type that is passed
856 -- by copy, then we must pass the parameter by copy.
858 if Nkind (Actual) = N_Type_Conversion
860 (Is_Numeric_Type (E_Formal)
861 or else Is_Access_Type (E_Formal)
862 or else Is_Enumeration_Type (E_Formal)
863 or else Is_Bit_Packed_Array (Etype (Formal))
864 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
866 -- Also pass by copy if change of representation
868 or else not Same_Representation
870 Etype (Expression (Actual))))
872 Add_Call_By_Copy_Code;
874 -- References to components of bit packed arrays are expanded
875 -- at this point, rather than at the point of analysis of the
876 -- actuals, to handle the expansion of the assignment to
877 -- [in] out parameters.
879 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
880 Add_Packed_Call_By_Copy_Code;
882 -- References to slices of bit packed arrays are expanded
884 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
885 Add_Call_By_Copy_Code;
887 -- Deal with access types where the actual subtpe and the
888 -- formal subtype are not the same, requiring a check.
890 -- It is neccessary to exclude tagged types because of "downward
891 -- conversion" errors and a strange assertion error in namet
892 -- from gnatf in bug 1215-001 ???
894 elsif Is_Access_Type (E_Formal)
895 and then not Same_Type (E_Formal, Etype (Actual))
896 and then not Is_Tagged_Type (Designated_Type (E_Formal))
898 Add_Call_By_Copy_Code;
900 elsif Is_Entity_Name (Actual)
901 and then Is_Volatile (Entity (Actual))
902 and then not Is_Scalar_Type (Etype (Entity (Actual)))
903 and then not Is_Volatile (E_Formal)
905 Add_Call_By_Copy_Code;
907 elsif Nkind (Actual) = N_Indexed_Component
908 and then Is_Entity_Name (Prefix (Actual))
909 and then Has_Volatile_Components (Entity (Prefix (Actual)))
911 Add_Call_By_Copy_Code;
914 -- The only processing required for IN parameters is in the packed
915 -- array case, where we expand the indexed component (the circuit
916 -- in Exp_Ch4 deliberately left indexed components appearing as
917 -- actuals untouched, so that the special processing above for
918 -- the OUT and IN OUT cases could be performed. We could make the
919 -- test in Exp_Ch4 more complex and have it detect the parameter
920 -- mode, but it is easier simply to handle all cases here.
922 -- Similarly, we have to expand slices of packed arrays here
925 if Nkind (Actual) = N_Indexed_Component
926 and then Is_Packed (Etype (Prefix (Actual)))
929 Expand_Packed_Element_Reference (Actual);
931 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
932 Add_Packed_Call_By_Copy_Code;
934 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
936 Typ : constant Entity_Id := Etype (Actual);
938 Ent : constant Entity_Id :=
939 Make_Defining_Identifier (Loc,
940 Chars => New_Internal_Name ('T'));
942 Decl : constant Node_Id :=
943 Make_Object_Declaration (Loc,
944 Defining_Identifier => Ent,
946 New_Occurrence_Of (Typ, Loc));
949 Set_No_Initialization (Decl);
951 Insert_Actions (N, New_List (
953 Make_Assignment_Statement (Loc,
954 Name => New_Occurrence_Of (Ent, Loc),
955 Expression => Relocate_Node (Actual))));
958 (Actual, New_Occurrence_Of (Ent, Loc));
959 Analyze_And_Resolve (Actual, Typ);
964 Next_Formal (Formal);
965 Next_Actual (Actual);
968 -- Find right place to put post call stuff if it is present
970 if not Is_Empty_List (Post_Call) then
972 -- If call is not a list member, it must be the triggering
973 -- statement of a triggering alternative or an entry call
974 -- alternative, and we can add the post call stuff to the
975 -- corresponding statement list.
977 if not Is_List_Member (N) then
979 P : constant Node_Id := Parent (N);
982 pragma Assert (Nkind (P) = N_Triggering_Alternative
983 or else Nkind (P) = N_Entry_Call_Alternative);
985 if Is_Non_Empty_List (Statements (P)) then
986 Insert_List_Before_And_Analyze
987 (First (Statements (P)), Post_Call);
989 Set_Statements (P, Post_Call);
993 -- Otherwise, normal case where N is in a statement sequence,
994 -- just put the post-call stuff after the call statement.
997 Insert_Actions_After (N, Post_Call);
1001 -- The call node itself is re-analyzed in Expand_Call.
1009 -- This procedure handles expansion of function calls and procedure call
1010 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1011 -- Expand_N_Procedure_Call_Statement. Processing for calls includes:
1013 -- Replace call to Raise_Exception by Raise_Exception always if possible
1014 -- Provide values of actuals for all formals in Extra_Formals list
1015 -- Replace "call" to enumeration literal function by literal itself
1016 -- Rewrite call to predefined operator as operator
1017 -- Replace actuals to in-out parameters that are numeric conversions,
1018 -- with explicit assignment to temporaries before and after the call.
1019 -- Remove optional actuals if First_Optional_Parameter specified.
1021 -- Note that the list of actuals has been filled with default expressions
1022 -- during semantic analysis of the call. Only the extra actuals required
1023 -- for the 'Constrained attribute and for accessibility checks are added
1026 procedure Expand_Call (N : Node_Id) is
1027 Loc : constant Source_Ptr := Sloc (N);
1028 Remote : constant Boolean := Is_Remote_Call (N);
1030 Orig_Subp : Entity_Id := Empty;
1031 Parent_Subp : Entity_Id;
1032 Parent_Formal : Entity_Id;
1035 Prev : Node_Id := Empty;
1036 Prev_Orig : Node_Id;
1038 Extra_Actuals : List_Id := No_List;
1041 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1042 -- Adds one entry to the end of the actual parameter list. Used for
1043 -- default parameters and for extra actuals (for Extra_Formals).
1044 -- The argument is an N_Parameter_Association node.
1046 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1047 -- Adds an extra actual to the list of extra actuals. Expr
1048 -- is the expression for the value of the actual, EF is the
1049 -- entity for the extra formal.
1051 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1052 -- Within an instance, a type derived from a non-tagged formal derived
1053 -- type inherits from the original parent, not from the actual. This is
1054 -- tested in 4723-003. The current derivation mechanism has the derived
1055 -- type inherit from the actual, which is only correct outside of the
1056 -- instance. If the subprogram is inherited, we test for this particular
1057 -- case through a convoluted tree traversal before setting the proper
1058 -- subprogram to be called.
1060 --------------------------
1061 -- Add_Actual_Parameter --
1062 --------------------------
1064 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1065 Actual_Expr : constant Node_Id :=
1066 Explicit_Actual_Parameter (Insert_Param);
1069 -- Case of insertion is first named actual
1071 if No (Prev) or else
1072 Nkind (Parent (Prev)) /= N_Parameter_Association
1074 Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
1075 Set_First_Named_Actual (N, Actual_Expr);
1078 if not Present (Parameter_Associations (N)) then
1079 Set_Parameter_Associations (N, New_List);
1080 Append (Insert_Param, Parameter_Associations (N));
1083 Insert_After (Prev, Insert_Param);
1086 -- Case of insertion is not first named actual
1089 Set_Next_Named_Actual
1090 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1091 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1092 Append (Insert_Param, Parameter_Associations (N));
1095 Prev := Actual_Expr;
1096 end Add_Actual_Parameter;
1098 ----------------------
1099 -- Add_Extra_Actual --
1100 ----------------------
1102 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1103 Loc : constant Source_Ptr := Sloc (Expr);
1106 if Extra_Actuals = No_List then
1107 Extra_Actuals := New_List;
1108 Set_Parent (Extra_Actuals, N);
1111 Append_To (Extra_Actuals,
1112 Make_Parameter_Association (Loc,
1113 Explicit_Actual_Parameter => Expr,
1115 Make_Identifier (Loc, Chars (EF))));
1117 Analyze_And_Resolve (Expr, Etype (EF));
1119 end Add_Extra_Actual;
1121 ---------------------------
1122 -- Inherited_From_Formal --
1123 ---------------------------
1125 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1127 Gen_Par : Entity_Id;
1128 Gen_Prim : Elist_Id;
1133 -- If the operation is inherited, it is attached to the corresponding
1134 -- type derivation. If the parent in the derivation is a generic
1135 -- actual, it is a subtype of the actual, and we have to recover the
1136 -- original derived type declaration to find the proper parent.
1138 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1139 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1140 or else Nkind (Type_Definition (Original_Node (Parent (S))))
1141 /= N_Derived_Type_Definition
1148 (Type_Definition (Original_Node (Parent (S)))));
1150 if Nkind (Indic) = N_Subtype_Indication then
1151 Par := Entity (Subtype_Mark (Indic));
1153 Par := Entity (Indic);
1157 if not Is_Generic_Actual_Type (Par)
1158 or else Is_Tagged_Type (Par)
1159 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1160 or else not In_Open_Scopes (Scope (Par))
1161 or else not In_Instance
1166 Gen_Par := Generic_Parent_Type (Parent (Par));
1169 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
1170 Elmt := First_Elmt (Gen_Prim);
1172 while Present (Elmt) loop
1173 if Chars (Node (Elmt)) = Chars (S) then
1179 F1 := First_Formal (S);
1180 F2 := First_Formal (Node (Elmt));
1183 and then Present (F2)
1186 if Etype (F1) = Etype (F2)
1187 or else Etype (F2) = Gen_Par
1193 exit; -- not the right subprogram
1205 raise Program_Error;
1206 end Inherited_From_Formal;
1208 -- Start of processing for Expand_Call
1211 -- Call using access to subprogram with explicit dereference
1213 if Nkind (Name (N)) = N_Explicit_Dereference then
1214 Subp := Etype (Name (N));
1215 Parent_Subp := Empty;
1217 -- Case of call to simple entry, where the Name is a selected component
1218 -- whose prefix is the task, and whose selector name is the entry name
1220 elsif Nkind (Name (N)) = N_Selected_Component then
1221 Subp := Entity (Selector_Name (Name (N)));
1222 Parent_Subp := Empty;
1224 -- Case of call to member of entry family, where Name is an indexed
1225 -- component, with the prefix being a selected component giving the
1226 -- task and entry family name, and the index being the entry index.
1228 elsif Nkind (Name (N)) = N_Indexed_Component then
1229 Subp := Entity (Selector_Name (Prefix (Name (N))));
1230 Parent_Subp := Empty;
1235 Subp := Entity (Name (N));
1236 Parent_Subp := Alias (Subp);
1238 -- Replace call to Raise_Exception by call to Raise_Exception_Always
1239 -- if we can tell that the first parameter cannot possibly be null.
1241 if not Restrictions (No_Exception_Handlers)
1242 and then Is_RTE (Subp, RE_Raise_Exception)
1245 FA : constant Node_Id := Original_Node (First_Actual (N));
1248 -- The case we catch is where the first argument is obtained
1249 -- using the Identity attribute (which must always be non-null)
1251 if Nkind (FA) = N_Attribute_Reference
1252 and then Attribute_Name (FA) = Name_Identity
1254 Subp := RTE (RE_Raise_Exception_Always);
1255 Set_Entity (Name (N), Subp);
1260 if Ekind (Subp) = E_Entry then
1261 Parent_Subp := Empty;
1265 -- First step, compute extra actuals, corresponding to any
1266 -- Extra_Formals present. Note that we do not access Extra_Formals
1267 -- directly, instead we simply note the presence of the extra
1268 -- formals as we process the regular formals and collect the
1269 -- corresponding actuals in Extra_Actuals.
1271 Formal := First_Formal (Subp);
1272 Actual := First_Actual (N);
1274 while Present (Formal) loop
1276 Prev_Orig := Original_Node (Prev);
1278 -- Create possible extra actual for constrained case. Usually,
1279 -- the extra actual is of the form actual'constrained, but since
1280 -- this attribute is only available for unconstrained records,
1281 -- TRUE is expanded if the type of the formal happens to be
1282 -- constrained (for instance when this procedure is inherited
1283 -- from an unconstrained record to a constrained one) or if the
1284 -- actual has no discriminant (its type is constrained). An
1285 -- exception to this is the case of a private type without
1286 -- discriminants. In this case we pass FALSE because the
1287 -- object has underlying discriminants with defaults.
1289 if Present (Extra_Constrained (Formal)) then
1290 if Ekind (Etype (Prev)) in Private_Kind
1291 and then not Has_Discriminants (Base_Type (Etype (Prev)))
1294 New_Occurrence_Of (Standard_False, Loc),
1295 Extra_Constrained (Formal));
1297 elsif Is_Constrained (Etype (Formal))
1298 or else not Has_Discriminants (Etype (Prev))
1301 New_Occurrence_Of (Standard_True, Loc),
1302 Extra_Constrained (Formal));
1305 -- If the actual is a type conversion, then the constrained
1306 -- test applies to the actual, not the target type.
1309 Act_Prev : Node_Id := Prev;
1312 -- Test for unchecked conversions as well, which can
1313 -- occur as out parameter actuals on calls to stream
1316 if Nkind (Act_Prev) = N_Type_Conversion
1317 or else Nkind (Act_Prev) = N_Unchecked_Type_Conversion
1319 Act_Prev := Expression (Act_Prev);
1323 Make_Attribute_Reference (Sloc (Prev),
1324 Prefix => Duplicate_Subexpr (Act_Prev, Name_Req => True),
1325 Attribute_Name => Name_Constrained),
1326 Extra_Constrained (Formal));
1331 -- Create possible extra actual for accessibility level
1333 if Present (Extra_Accessibility (Formal)) then
1334 if Is_Entity_Name (Prev_Orig) then
1336 -- When passing an access parameter as the actual to another
1337 -- access parameter we need to pass along the actual's own
1338 -- associated access level parameter. This is done is we are
1339 -- in the scope of the formal access parameter (if this is an
1340 -- inlined body the extra formal is irrelevant).
1342 if Ekind (Entity (Prev_Orig)) in Formal_Kind
1343 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
1344 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
1347 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
1350 pragma Assert (Present (Parm_Ent));
1352 if Present (Extra_Accessibility (Parm_Ent)) then
1355 (Extra_Accessibility (Parm_Ent), Loc),
1356 Extra_Accessibility (Formal));
1358 -- If the actual access parameter does not have an
1359 -- associated extra formal providing its scope level,
1360 -- then treat the actual as having library-level
1365 Make_Integer_Literal (Loc,
1366 Intval => Scope_Depth (Standard_Standard)),
1367 Extra_Accessibility (Formal));
1371 -- The actual is a normal access value, so just pass the
1372 -- level of the actual's access type.
1376 Make_Integer_Literal (Loc,
1377 Intval => Type_Access_Level (Etype (Prev_Orig))),
1378 Extra_Accessibility (Formal));
1382 case Nkind (Prev_Orig) is
1384 when N_Attribute_Reference =>
1386 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
1388 -- For X'Access, pass on the level of the prefix X
1390 when Attribute_Access =>
1392 Make_Integer_Literal (Loc,
1394 Object_Access_Level (Prefix (Prev_Orig))),
1395 Extra_Accessibility (Formal));
1397 -- Treat the unchecked attributes as library-level
1399 when Attribute_Unchecked_Access |
1400 Attribute_Unrestricted_Access =>
1402 Make_Integer_Literal (Loc,
1403 Intval => Scope_Depth (Standard_Standard)),
1404 Extra_Accessibility (Formal));
1406 -- No other cases of attributes returning access
1407 -- values that can be passed to access parameters
1410 raise Program_Error;
1414 -- For allocators we pass the level of the execution of
1415 -- the called subprogram, which is one greater than the
1416 -- current scope level.
1420 Make_Integer_Literal (Loc,
1421 Scope_Depth (Current_Scope) + 1),
1422 Extra_Accessibility (Formal));
1424 -- For other cases we simply pass the level of the
1425 -- actual's access type.
1429 Make_Integer_Literal (Loc,
1430 Intval => Type_Access_Level (Etype (Prev_Orig))),
1431 Extra_Accessibility (Formal));
1437 -- Perform the check of 4.6(49) that prevents a null value
1438 -- from being passed as an actual to an access parameter.
1439 -- Note that the check is elided in the common cases of
1440 -- passing an access attribute or access parameter as an
1441 -- actual. Also, we currently don't enforce this check for
1442 -- expander-generated actuals and when -gnatdj is set.
1444 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
1445 or else Suppress_Accessibility_Checks (Subp)
1449 elsif Debug_Flag_J then
1452 elsif not Comes_From_Source (Prev) then
1455 elsif Is_Entity_Name (Prev)
1456 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
1460 elsif Nkind (Prev) = N_Allocator
1461 or else Nkind (Prev) = N_Attribute_Reference
1465 -- Suppress null checks when passing to access parameters
1466 -- of Java subprograms. (Should this be done for other
1467 -- foreign conventions as well ???)
1469 elsif Convention (Subp) = Convention_Java then
1475 Left_Opnd => Duplicate_Subexpr (Prev),
1476 Right_Opnd => Make_Null (Loc));
1477 Insert_Action (Prev, Make_Raise_Constraint_Error (Loc, Cond));
1480 -- Perform apropriate validity checks on parameters
1482 if Validity_Checks_On then
1484 if Ekind (Formal) = E_In_Parameter
1485 and then Validity_Check_In_Params
1487 Ensure_Valid (Actual);
1489 elsif Ekind (Formal) = E_In_Out_Parameter
1490 and then Validity_Check_In_Out_Params
1492 Ensure_Valid (Actual);
1496 -- For IN OUT and OUT parameters, ensure that subscripts are valid
1497 -- since this is a left side reference. We only do this for calls
1498 -- from the source program since we assume that compiler generated
1499 -- calls explicitly generate any required checks. We also need it
1500 -- only if we are doing standard validity checks, since clearly it
1501 -- is not needed if validity checks are off, and in subscript
1502 -- validity checking mode, all indexed components are checked with
1503 -- a call directly from Expand_N_Indexed_Component.
1505 if Comes_From_Source (N)
1506 and then Ekind (Formal) /= E_In_Parameter
1507 and then Validity_Checks_On
1508 and then Validity_Check_Default
1509 and then not Validity_Check_Subscripts
1511 Check_Valid_Lvalue_Subscripts (Actual);
1514 -- If the formal is class wide and the actual is an aggregate, force
1515 -- evaluation so that the back end who does not know about class-wide
1516 -- type, does not generate a temporary of the wrong size.
1518 if not Is_Class_Wide_Type (Etype (Formal)) then
1521 elsif Nkind (Actual) = N_Aggregate
1522 or else (Nkind (Actual) = N_Qualified_Expression
1523 and then Nkind (Expression (Actual)) = N_Aggregate)
1525 Force_Evaluation (Actual);
1528 -- In a remote call, if the formal is of a class-wide type, check
1529 -- that the actual meets the requirements described in E.4(18).
1532 and then Is_Class_Wide_Type (Etype (Formal))
1534 Insert_Action (Actual,
1535 Make_Implicit_If_Statement (N,
1538 Get_Remotely_Callable (Duplicate_Subexpr (Actual))),
1539 Then_Statements => New_List (
1540 Make_Procedure_Call_Statement (Loc,
1541 New_Occurrence_Of (RTE
1542 (RE_Raise_Program_Error_For_E_4_18), Loc)))));
1545 Next_Actual (Actual);
1546 Next_Formal (Formal);
1549 -- If we are expanding a rhs of an assignement we need to check if
1550 -- tag propagation is needed. This code belongs theorically in Analyze
1551 -- Assignment but has to be done earlier (bottom-up) because the
1552 -- assignment might be transformed into a declaration for an uncons-
1553 -- trained value, if the expression is classwide.
1555 if Nkind (N) = N_Function_Call
1556 and then Is_Tag_Indeterminate (N)
1557 and then Is_Entity_Name (Name (N))
1560 Ass : Node_Id := Empty;
1563 if Nkind (Parent (N)) = N_Assignment_Statement then
1566 elsif Nkind (Parent (N)) = N_Qualified_Expression
1567 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
1569 Ass := Parent (Parent (N));
1573 and then Is_Class_Wide_Type (Etype (Name (Ass)))
1575 Propagate_Tag (Name (Ass), N);
1581 -- Deals with Dispatch_Call if we still have a call, before expanding
1582 -- extra actuals since this will be done on the re-analysis of the
1583 -- dispatching call. Note that we do not try to shorten the actual
1584 -- list for a dispatching call, it would not make sense to do so.
1585 -- Expansion of dispatching calls is suppressed when Java_VM, because
1586 -- the JVM back end directly handles the generation of dispatching
1587 -- calls and would have to undo any expansion to an indirect call.
1589 if (Nkind (N) = N_Function_Call
1590 or else Nkind (N) = N_Procedure_Call_Statement)
1591 and then Present (Controlling_Argument (N))
1592 and then not Java_VM
1594 Expand_Dispatch_Call (N);
1597 -- Similarly, expand calls to RCI subprograms on which pragma
1598 -- All_Calls_Remote applies. The rewriting will be reanalyzed
1599 -- later. Do this only when the call comes from source since we do
1600 -- not want such a rewritting to occur in expanded code.
1602 elsif Is_All_Remote_Call (N) then
1603 Expand_All_Calls_Remote_Subprogram_Call (N);
1605 -- Similarly, do not add extra actuals for an entry call whose entity
1606 -- is a protected procedure, or for an internal protected subprogram
1607 -- call, because it will be rewritten as a protected subprogram call
1608 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
1610 elsif Is_Protected_Type (Scope (Subp))
1611 and then (Ekind (Subp) = E_Procedure
1612 or else Ekind (Subp) = E_Function)
1616 -- During that loop we gathered the extra actuals (the ones that
1617 -- correspond to Extra_Formals), so now they can be appended.
1620 while Is_Non_Empty_List (Extra_Actuals) loop
1621 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
1625 if Ekind (Subp) = E_Procedure
1626 or else (Ekind (Subp) = E_Subprogram_Type
1627 and then Etype (Subp) = Standard_Void_Type)
1628 or else Is_Entry (Subp)
1630 Expand_Actuals (N, Subp);
1633 -- If the subprogram is a renaming, or if it is inherited, replace it
1634 -- in the call with the name of the actual subprogram being called.
1635 -- If this is a dispatching call, the run-time decides what to call.
1636 -- The Alias attribute does not apply to entries.
1638 if Nkind (N) /= N_Entry_Call_Statement
1639 and then No (Controlling_Argument (N))
1640 and then Present (Parent_Subp)
1642 if Present (Inherited_From_Formal (Subp)) then
1643 Parent_Subp := Inherited_From_Formal (Subp);
1645 while Present (Alias (Parent_Subp)) loop
1646 Parent_Subp := Alias (Parent_Subp);
1650 Set_Entity (Name (N), Parent_Subp);
1652 if Is_Abstract (Parent_Subp)
1653 and then not In_Instance
1656 ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
1659 -- Add an explicit conversion for parameter of the derived type.
1660 -- This is only done for scalar and access in-parameters. Others
1661 -- have been expanded in expand_actuals.
1663 Formal := First_Formal (Subp);
1664 Parent_Formal := First_Formal (Parent_Subp);
1665 Actual := First_Actual (N);
1667 -- It is not clear that conversion is needed for intrinsic
1668 -- subprograms, but it certainly is for those that are user-
1669 -- defined, and that can be inherited on derivation, namely
1670 -- unchecked conversion and deallocation.
1671 -- General case needs study ???
1673 if not Is_Intrinsic_Subprogram (Parent_Subp)
1674 or else Is_Generic_Instance (Parent_Subp)
1676 while Present (Formal) loop
1678 if Etype (Formal) /= Etype (Parent_Formal)
1679 and then Is_Scalar_Type (Etype (Formal))
1680 and then Ekind (Formal) = E_In_Parameter
1683 OK_Convert_To (Etype (Parent_Formal),
1684 Relocate_Node (Actual)));
1687 Resolve (Actual, Etype (Parent_Formal));
1688 Enable_Range_Check (Actual);
1690 elsif Is_Access_Type (Etype (Formal))
1691 and then Base_Type (Etype (Parent_Formal))
1692 /= Base_Type (Etype (Actual))
1694 if Ekind (Formal) /= E_In_Parameter then
1696 Convert_To (Etype (Parent_Formal),
1697 Relocate_Node (Actual)));
1700 Resolve (Actual, Etype (Parent_Formal));
1703 Ekind (Etype (Parent_Formal)) = E_Anonymous_Access_Type
1705 Designated_Type (Etype (Parent_Formal))
1706 /= Designated_Type (Etype (Actual))
1707 and then not Is_Controlling_Formal (Formal)
1710 -- This unchecked conversion is not necessary unless
1711 -- inlining is unabled, because in that case the type
1712 -- mismatch may become visible in the body about to be
1716 Unchecked_Convert_To (Etype (Parent_Formal),
1717 Relocate_Node (Actual)));
1720 Resolve (Actual, Etype (Parent_Formal));
1724 Next_Formal (Formal);
1725 Next_Formal (Parent_Formal);
1726 Next_Actual (Actual);
1731 Subp := Parent_Subp;
1734 -- Some more special cases for cases other than explicit dereference
1736 if Nkind (Name (N)) /= N_Explicit_Dereference then
1738 -- Calls to an enumeration literal are replaced by the literal
1739 -- This case occurs only when we have a call to a function that
1740 -- is a renaming of an enumeration literal. The normal case of
1741 -- a direct reference to an enumeration literal has already been
1742 -- been dealt with by Resolve_Call. If the function is itself
1743 -- inherited (see 7423-001) the literal of the parent type must
1744 -- be explicitly converted to the return type of the function.
1746 if Ekind (Subp) = E_Enumeration_Literal then
1747 if Base_Type (Etype (Subp)) /= Base_Type (Etype (N)) then
1749 (N, Convert_To (Etype (N), New_Occurrence_Of (Subp, Loc)));
1751 Rewrite (N, New_Occurrence_Of (Subp, Loc));
1752 Resolve (N, Etype (N));
1756 -- Handle case of access to protected subprogram type
1759 if Ekind (Base_Type (Etype (Prefix (Name (N))))) =
1760 E_Access_Protected_Subprogram_Type
1762 -- If this is a call through an access to protected operation,
1763 -- the prefix has the form (object'address, operation'access).
1764 -- Rewrite as a for other protected calls: the object is the
1765 -- first parameter of the list of actuals.
1772 Ptr : Node_Id := Prefix (Name (N));
1773 T : Entity_Id := Equivalent_Type (Base_Type (Etype (Ptr)));
1774 D_T : Entity_Id := Designated_Type (Base_Type (Etype (Ptr)));
1777 Obj := Make_Selected_Component (Loc,
1778 Prefix => Unchecked_Convert_To (T, Ptr),
1779 Selector_Name => New_Occurrence_Of (First_Entity (T), Loc));
1781 Nam := Make_Selected_Component (Loc,
1782 Prefix => Unchecked_Convert_To (T, Ptr),
1783 Selector_Name => New_Occurrence_Of (
1784 Next_Entity (First_Entity (T)), Loc));
1786 Nam := Make_Explicit_Dereference (Loc, Nam);
1788 if Present (Parameter_Associations (N)) then
1789 Parm := Parameter_Associations (N);
1794 Prepend (Obj, Parm);
1796 if Etype (D_T) = Standard_Void_Type then
1797 Call := Make_Procedure_Call_Statement (Loc,
1799 Parameter_Associations => Parm);
1801 Call := Make_Function_Call (Loc,
1803 Parameter_Associations => Parm);
1806 Set_First_Named_Actual (Call, First_Named_Actual (N));
1808 Set_Etype (Call, Etype (D_T));
1810 -- We do not re-analyze the call to avoid infinite recursion.
1811 -- We analyze separately the prefix and the object, and set
1812 -- the checks on the prefix that would otherwise be emitted
1813 -- when resolving a call.
1817 Apply_Access_Check (Nam);
1824 -- If this is a call to an intrinsic subprogram, then perform the
1825 -- appropriate expansion to the corresponding tree node and we
1826 -- are all done (since after that the call is gone!)
1828 if Is_Intrinsic_Subprogram (Subp) then
1829 Expand_Intrinsic_Call (N, Subp);
1833 if Ekind (Subp) = E_Function
1834 or else Ekind (Subp) = E_Procedure
1836 if Is_Inlined (Subp) then
1839 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
1842 -- Verify that the body to inline has already been seen,
1843 -- and that if the body is in the current unit the inlining
1844 -- does not occur earlier. This avoids order-of-elaboration
1845 -- problems in gigi.
1848 and then Nkind (Spec) = N_Subprogram_Declaration
1849 and then Present (Body_To_Inline (Spec))
1850 and then (In_Extended_Main_Code_Unit (N)
1851 or else In_Extended_Main_Code_Unit (Parent (N)))
1852 and then (not In_Same_Extended_Unit
1853 (Sloc (Body_To_Inline (Spec)), Loc)
1855 Earlier_In_Extended_Unit
1856 (Sloc (Body_To_Inline (Spec)), Loc))
1858 Expand_Inlined_Call (N, Subp, Orig_Subp);
1861 -- Let the back-end handle it.
1863 Add_Inlined_Body (Subp);
1865 if Front_End_Inlining
1866 and then Nkind (Spec) = N_Subprogram_Declaration
1867 and then (In_Extended_Main_Code_Unit (N))
1868 and then No (Body_To_Inline (Spec))
1869 and then not Has_Completion (Subp)
1870 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
1871 and then Ineffective_Inline_Warnings
1874 ("call cannot be inlined before body is seen?", N);
1881 -- Check for a protected subprogram. This is either an intra-object
1882 -- call, or a protected function call. Protected procedure calls are
1883 -- rewritten as entry calls and handled accordingly.
1885 Scop := Scope (Subp);
1887 if Nkind (N) /= N_Entry_Call_Statement
1888 and then Is_Protected_Type (Scop)
1890 -- If the call is an internal one, it is rewritten as a call to
1891 -- to the corresponding unprotected subprogram.
1893 Expand_Protected_Subprogram_Call (N, Subp, Scop);
1896 -- Functions returning controlled objects need special attention
1898 if Controlled_Type (Etype (Subp))
1899 and then not Is_Return_By_Reference_Type (Etype (Subp))
1901 Expand_Ctrl_Function_Call (N);
1904 -- Test for First_Optional_Parameter, and if so, truncate parameter
1905 -- list if there are optional parameters at the trailing end.
1906 -- Note we never delete procedures for call via a pointer.
1908 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
1909 and then Present (First_Optional_Parameter (Subp))
1912 Last_Keep_Arg : Node_Id;
1915 -- Last_Keep_Arg will hold the last actual that should be
1916 -- retained. If it remains empty at the end, it means that
1917 -- all parameters are optional.
1919 Last_Keep_Arg := Empty;
1921 -- Find first optional parameter, must be present since we
1922 -- checked the validity of the parameter before setting it.
1924 Formal := First_Formal (Subp);
1925 Actual := First_Actual (N);
1926 while Formal /= First_Optional_Parameter (Subp) loop
1927 Last_Keep_Arg := Actual;
1928 Next_Formal (Formal);
1929 Next_Actual (Actual);
1932 -- Now we have Formal and Actual pointing to the first
1933 -- potentially droppable argument. We can drop all the
1934 -- trailing arguments whose actual matches the default.
1935 -- Note that we know that all remaining formals have
1936 -- defaults, because we checked that this requirement
1937 -- was met before setting First_Optional_Parameter.
1939 -- We use Fully_Conformant_Expressions to check for identity
1940 -- between formals and actuals, which may miss some cases, but
1941 -- on the other hand, this is only an optimization (if we fail
1942 -- to truncate a parameter it does not affect functionality).
1943 -- So if the default is 3 and the actual is 1+2, we consider
1944 -- them unequal, which hardly seems worrisome.
1946 while Present (Formal) loop
1947 if not Fully_Conformant_Expressions
1948 (Actual, Default_Value (Formal))
1950 Last_Keep_Arg := Actual;
1953 Next_Formal (Formal);
1954 Next_Actual (Actual);
1957 -- If no arguments, delete entire list, this is the easy case
1959 if No (Last_Keep_Arg) then
1960 while Is_Non_Empty_List (Parameter_Associations (N)) loop
1961 Delete_Tree (Remove_Head (Parameter_Associations (N)));
1964 Set_Parameter_Associations (N, No_List);
1965 Set_First_Named_Actual (N, Empty);
1967 -- Case where at the last retained argument is positional. This
1968 -- is also an easy case, since the retained arguments are already
1969 -- in the right form, and we don't need to worry about the order
1970 -- of arguments that get eliminated.
1972 elsif Is_List_Member (Last_Keep_Arg) then
1973 while Present (Next (Last_Keep_Arg)) loop
1974 Delete_Tree (Remove_Next (Last_Keep_Arg));
1977 Set_First_Named_Actual (N, Empty);
1979 -- This is the annoying case where the last retained argument
1980 -- is a named parameter. Since the original arguments are not
1981 -- in declaration order, we may have to delete some fairly
1982 -- random collection of arguments.
1991 -- First step, remove all the named parameters from the
1992 -- list (they are still chained using First_Named_Actual
1993 -- and Next_Named_Actual, so we have not lost them!)
1995 Temp := First (Parameter_Associations (N));
1997 -- Case of all parameters named, remove them all
1999 if Nkind (Temp) = N_Parameter_Association then
2000 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2001 Temp := Remove_Head (Parameter_Associations (N));
2004 -- Case of mixed positional/named, remove named parameters
2007 while Nkind (Next (Temp)) /= N_Parameter_Association loop
2011 while Present (Next (Temp)) loop
2012 Junk := Remove_Next (Temp);
2016 -- Now we loop through the named parameters, till we get
2017 -- to the last one to be retained, adding them to the list.
2018 -- Note that the Next_Named_Actual list does not need to be
2019 -- touched since we are only reordering them on the actual
2020 -- parameter association list.
2022 Passoc := Parent (First_Named_Actual (N));
2024 Temp := Relocate_Node (Passoc);
2026 (Parameter_Associations (N), Temp);
2028 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
2029 Passoc := Parent (Next_Named_Actual (Passoc));
2032 Set_Next_Named_Actual (Temp, Empty);
2035 Temp := Next_Named_Actual (Passoc);
2036 exit when No (Temp);
2037 Set_Next_Named_Actual
2038 (Passoc, Next_Named_Actual (Parent (Temp)));
2048 --------------------------
2049 -- Expand_Inlined_Call --
2050 --------------------------
2052 procedure Expand_Inlined_Call
2055 Orig_Subp : Entity_Id)
2057 Loc : constant Source_Ptr := Sloc (N);
2061 Exit_Lab : Entity_Id := Empty;
2068 Orig_Bod : constant Node_Id :=
2069 Body_To_Inline (Unit_Declaration_Node (Subp));
2070 Ret_Type : Entity_Id;
2073 Temp_Typ : Entity_Id;
2075 procedure Make_Exit_Label;
2076 -- Build declaration for exit label to be used in Return statements.
2078 function Process_Formals (N : Node_Id) return Traverse_Result;
2079 -- Replace occurrence of a formal with the corresponding actual, or
2080 -- the thunk generated for it.
2082 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
2083 -- If the function body is a single expression, replace call with
2084 -- expression, else insert block appropriately.
2086 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
2087 -- If procedure body has no local variables, inline body without
2088 -- creating block, otherwise rewrite call with block.
2090 ---------------------
2091 -- Make_Exit_Label --
2092 ---------------------
2094 procedure Make_Exit_Label is
2096 -- Create exit label for subprogram, if one doesn't exist yet.
2098 if No (Exit_Lab) then
2099 Lab_Id := Make_Identifier (Loc, New_Internal_Name ('L'));
2101 Make_Defining_Identifier (Loc, Chars (Lab_Id)));
2102 Exit_Lab := Make_Label (Loc, Lab_Id);
2105 Make_Implicit_Label_Declaration (Loc,
2106 Defining_Identifier => Entity (Lab_Id),
2107 Label_Construct => Exit_Lab);
2109 end Make_Exit_Label;
2111 ---------------------
2112 -- Process_Formals --
2113 ---------------------
2115 function Process_Formals (N : Node_Id) return Traverse_Result is
2121 if Is_Entity_Name (N)
2122 and then Present (Entity (N))
2127 and then Scope (E) = Subp
2129 A := Renamed_Object (E);
2131 if Is_Entity_Name (A) then
2132 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
2134 elsif Nkind (A) = N_Defining_Identifier then
2135 Rewrite (N, New_Occurrence_Of (A, Loc));
2137 else -- numeric literal
2138 Rewrite (N, New_Copy (A));
2144 elsif Nkind (N) = N_Return_Statement then
2146 if No (Expression (N)) then
2148 Rewrite (N, Make_Goto_Statement (Loc,
2149 Name => New_Copy (Lab_Id)));
2152 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
2153 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
2155 -- function body is a single expression. No need for
2160 Num_Ret := Num_Ret + 1;
2164 -- Because of the presence of private types, the views of the
2165 -- expression and the context may be different, so place an
2166 -- unchecked conversion to the context type to avoid spurious
2167 -- errors, eg. when the expression is a numeric literal and
2168 -- the context is private. If the expression is an aggregate,
2169 -- use a qualified expression, because an aggregate is not a
2170 -- legal argument of a conversion.
2172 if Nkind (Expression (N)) = N_Aggregate then
2174 Make_Qualified_Expression (Sloc (N),
2175 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
2176 Expression => Relocate_Node (Expression (N)));
2179 Unchecked_Convert_To
2180 (Ret_Type, Relocate_Node (Expression (N)));
2183 if Nkind (Targ) = N_Defining_Identifier then
2185 Make_Assignment_Statement (Loc,
2186 Name => New_Occurrence_Of (Targ, Loc),
2187 Expression => Ret));
2190 Make_Assignment_Statement (Loc,
2191 Name => New_Copy (Targ),
2192 Expression => Ret));
2195 Set_Assignment_OK (Name (N));
2197 if Present (Exit_Lab) then
2199 Make_Goto_Statement (Loc,
2200 Name => New_Copy (Lab_Id)));
2209 end Process_Formals;
2211 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
2213 ---------------------------
2214 -- Rewrite_Function_Call --
2215 ---------------------------
2217 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
2218 HSS : Node_Id := Handled_Statement_Sequence (Blk);
2219 Fst : Node_Id := First (Statements (HSS));
2223 -- Optimize simple case: function body is a single return statement,
2224 -- which has been expanded into an assignment.
2226 if Is_Empty_List (Declarations (Blk))
2227 and then Nkind (Fst) = N_Assignment_Statement
2228 and then No (Next (Fst))
2231 -- The function call may have been rewritten as the temporary
2232 -- that holds the result of the call, in which case remove the
2233 -- now useless declaration.
2235 if Nkind (N) = N_Identifier
2236 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2238 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
2241 Rewrite (N, Expression (Fst));
2243 elsif Nkind (N) = N_Identifier
2244 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2247 -- The block assigns the result of the call to the temporary.
2249 Insert_After (Parent (Entity (N)), Blk);
2251 elsif Nkind (Parent (N)) = N_Assignment_Statement
2252 and then Is_Entity_Name (Name (Parent (N)))
2255 -- replace assignment with the block.
2257 Rewrite (Parent (N), Blk);
2259 elsif Nkind (Parent (N)) = N_Object_Declaration then
2260 Set_Expression (Parent (N), Empty);
2261 Insert_After (Parent (N), Blk);
2263 end Rewrite_Function_Call;
2265 ----------------------------
2266 -- Rewrite_Procedure_Call --
2267 ----------------------------
2269 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
2270 HSS : Node_Id := Handled_Statement_Sequence (Blk);
2273 if Is_Empty_List (Declarations (Blk)) then
2274 Insert_List_After (N, Statements (HSS));
2275 Rewrite (N, Make_Null_Statement (Loc));
2279 end Rewrite_Procedure_Call;
2281 -- Start of processing for Expand_Inlined_Call
2284 if Nkind (Orig_Bod) = N_Defining_Identifier then
2286 -- Subprogram is a renaming_as_body. Calls appearing after the
2287 -- renaming can be replaced with calls to the renamed entity
2288 -- directly, because the subprograms are subtype conformant.
2290 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
2294 -- Use generic machinery to copy body of inlined subprogram, as if it
2295 -- were an instantiation, resetting source locations appropriately, so
2296 -- that nested inlined calls appear in the main unit.
2298 Save_Env (Subp, Empty);
2299 Set_Copied_Sloc (N, Defining_Entity (Orig_Bod));
2302 Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
2305 Make_Block_Statement (Loc,
2306 Declarations => Declarations (Bod),
2307 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
2309 if No (Declarations (Bod)) then
2310 Set_Declarations (Blk, New_List);
2313 -- If this is a derived function, establish the proper return type.
2315 if Present (Orig_Subp)
2316 and then Orig_Subp /= Subp
2318 Ret_Type := Etype (Orig_Subp);
2320 Ret_Type := Etype (Subp);
2323 F := First_Formal (Subp);
2324 A := First_Actual (N);
2326 -- Create temporaries for the actuals that are expressions, or that
2327 -- are scalars and require copying to preserve semantics.
2329 while Present (F) loop
2331 if Present (Renamed_Object (F)) then
2332 Error_Msg_N (" cannot inline call to recursive subprogram", N);
2336 -- If the argument may be a controlling argument in a call within
2337 -- the inlined body, we must preserve its classwide nature to
2338 -- insure that dynamic dispatching take place subsequently.
2339 -- If the formal has a constraint it must be preserved to retain
2340 -- the semantics of the body.
2342 if Is_Class_Wide_Type (Etype (F))
2343 or else (Is_Access_Type (Etype (F))
2345 Is_Class_Wide_Type (Designated_Type (Etype (F))))
2347 Temp_Typ := Etype (F);
2349 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
2350 and then Etype (F) /= Base_Type (Etype (F))
2352 Temp_Typ := Etype (F);
2355 Temp_Typ := Etype (A);
2358 if (not Is_Entity_Name (A)
2359 and then Nkind (A) /= N_Integer_Literal
2360 and then Nkind (A) /= N_Real_Literal)
2362 or else Is_Scalar_Type (Etype (A))
2365 Make_Defining_Identifier (Loc,
2366 Chars => New_Internal_Name ('C'));
2368 -- If the actual for an in/in-out parameter is a view conversion,
2369 -- make it into an unchecked conversion, given that an untagged
2370 -- type conversion is not a proper object for a renaming.
2371 -- In-out conversions that involve real conversions have already
2372 -- been transformed in Expand_Actuals.
2374 if Nkind (A) = N_Type_Conversion
2376 (Ekind (F) = E_In_Out_Parameter
2377 or else not Is_Tagged_Type (Etype (F)))
2379 New_A := Make_Unchecked_Type_Conversion (Loc,
2380 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
2381 Expression => Relocate_Node (Expression (A)));
2383 elsif Etype (F) /= Etype (A) then
2384 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
2385 Temp_Typ := Etype (F);
2388 New_A := Relocate_Node (A);
2391 Set_Sloc (New_A, Sloc (N));
2393 if Ekind (F) = E_In_Parameter
2394 and then not Is_Limited_Type (Etype (A))
2397 Make_Object_Declaration (Loc,
2398 Defining_Identifier => Temp,
2399 Constant_Present => True,
2400 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
2401 Expression => New_A);
2404 Make_Object_Renaming_Declaration (Loc,
2405 Defining_Identifier => Temp,
2406 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
2410 Prepend (Decl, Declarations (Blk));
2411 Set_Renamed_Object (F, Temp);
2414 if Etype (F) /= Etype (A) then
2416 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
2418 Set_Renamed_Object (F, A);
2426 -- Establish target of function call. If context is not assignment or
2427 -- declaration, create a temporary as a target. The declaration for
2428 -- the temporary may be subsequently optimized away if the body is a
2429 -- single expression, or if the left-hand side of the assignment is
2432 if Ekind (Subp) = E_Function then
2433 if Nkind (Parent (N)) = N_Assignment_Statement
2434 and then Is_Entity_Name (Name (Parent (N)))
2436 Targ := Name (Parent (N));
2439 -- Replace call with temporary, and create its declaration.
2442 Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
2445 Make_Object_Declaration (Loc,
2446 Defining_Identifier => Temp,
2447 Object_Definition =>
2448 New_Occurrence_Of (Ret_Type, Loc));
2450 Set_No_Initialization (Decl);
2451 Insert_Action (N, Decl);
2452 Rewrite (N, New_Occurrence_Of (Temp, Loc));
2457 -- Traverse the tree and replace formals with actuals or their thunks.
2458 -- Attach block to tree before analysis and rewriting.
2460 Replace_Formals (Blk);
2461 Set_Parent (Blk, N);
2463 if Present (Exit_Lab) then
2465 -- If the body was a single expression, the single return statement
2466 -- and the corresponding label are useless.
2470 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
2473 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
2475 Append (Lab_Decl, (Declarations (Blk)));
2476 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
2480 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
2481 -- conflicting private views that Gigi would ignore.
2484 I_Flag : constant Boolean := In_Inlined_Body;
2487 In_Inlined_Body := True;
2489 In_Inlined_Body := I_Flag;
2492 if Ekind (Subp) = E_Procedure then
2493 Rewrite_Procedure_Call (N, Blk);
2495 Rewrite_Function_Call (N, Blk);
2500 -- Cleanup mapping between formals and actuals, for other expansions.
2502 F := First_Formal (Subp);
2504 while Present (F) loop
2505 Set_Renamed_Object (F, Empty);
2508 end Expand_Inlined_Call;
2510 ----------------------------
2511 -- Expand_N_Function_Call --
2512 ----------------------------
2514 procedure Expand_N_Function_Call (N : Node_Id) is
2515 Typ : constant Entity_Id := Etype (N);
2517 function Returned_By_Reference return Boolean;
2518 -- If the return type is returned through the secondary stack. i.e.
2519 -- by reference, we don't want to create a temporary to force stack
2522 function Returned_By_Reference return Boolean is
2523 S : Entity_Id := Current_Scope;
2526 if Is_Return_By_Reference_Type (Typ) then
2529 elsif Nkind (Parent (N)) /= N_Return_Statement then
2532 elsif Requires_Transient_Scope (Typ) then
2534 -- Verify that the return type of the enclosing function has
2535 -- the same constrained status as that of the expression.
2537 while Ekind (S) /= E_Function loop
2541 return Is_Constrained (Typ) = Is_Constrained (Etype (S));
2545 end Returned_By_Reference;
2547 -- Start of processing for Expand_N_Function_Call
2550 -- A special check. If stack checking is enabled, and the return type
2551 -- might generate a large temporary, and the call is not the right
2552 -- side of an assignment, then generate an explicit temporary. We do
2553 -- this because otherwise gigi may generate a large temporary on the
2554 -- fly and this can cause trouble with stack checking.
2556 if May_Generate_Large_Temp (Typ)
2557 and then Nkind (Parent (N)) /= N_Assignment_Statement
2559 (Nkind (Parent (N)) /= N_Object_Declaration
2560 or else Expression (Parent (N)) /= N)
2561 and then not Returned_By_Reference
2563 -- Note: it might be thought that it would be OK to use a call to
2564 -- Force_Evaluation here, but that's not good enough, because that
2565 -- results in a 'Reference construct that may still need a temporary.
2568 Loc : constant Source_Ptr := Sloc (N);
2569 Temp_Obj : constant Entity_Id := Make_Defining_Identifier (Loc,
2570 New_Internal_Name ('F'));
2571 Temp_Typ : Entity_Id := Typ;
2578 if Is_Tagged_Type (Typ)
2579 and then Present (Controlling_Argument (N))
2581 if Nkind (Parent (N)) /= N_Procedure_Call_Statement
2582 and then Nkind (Parent (N)) /= N_Function_Call
2584 -- If this is a tag-indeterminate call, the object must
2587 if Is_Tag_Indeterminate (N) then
2588 Temp_Typ := Class_Wide_Type (Typ);
2592 -- If this is a dispatching call that is itself the
2593 -- controlling argument of an enclosing call, the nominal
2594 -- subtype of the object that replaces it must be classwide,
2595 -- so that dispatching will take place properly. If it is
2596 -- not a controlling argument, the object is not classwide.
2598 Proc := Entity (Name (Parent (N)));
2599 F := First_Formal (Proc);
2600 A := First_Actual (Parent (N));
2607 if Is_Controlling_Formal (F) then
2608 Temp_Typ := Class_Wide_Type (Typ);
2614 Make_Object_Declaration (Loc,
2615 Defining_Identifier => Temp_Obj,
2616 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
2617 Constant_Present => True,
2618 Expression => Relocate_Node (N));
2619 Set_Assignment_OK (Decl);
2621 Insert_Actions (N, New_List (Decl));
2622 Rewrite (N, New_Occurrence_Of (Temp_Obj, Loc));
2625 -- Normal case, expand the call
2630 end Expand_N_Function_Call;
2632 ---------------------------------------
2633 -- Expand_N_Procedure_Call_Statement --
2634 ---------------------------------------
2636 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
2639 end Expand_N_Procedure_Call_Statement;
2641 ------------------------------
2642 -- Expand_N_Subprogram_Body --
2643 ------------------------------
2645 -- Add poll call if ATC polling is enabled
2647 -- Add return statement if last statement in body is not a return
2648 -- statement (this makes things easier on Gigi which does not want
2649 -- to have to handle a missing return).
2651 -- Add call to Activate_Tasks if body is a task activator
2653 -- Deal with possible detection of infinite recursion
2655 -- Eliminate body completely if convention stubbed
2657 -- Encode entity names within body, since we will not need to reference
2658 -- these entities any longer in the front end.
2660 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
2662 procedure Expand_N_Subprogram_Body (N : Node_Id) is
2663 Loc : constant Source_Ptr := Sloc (N);
2664 H : constant Node_Id := Handled_Statement_Sequence (N);
2665 Spec_Id : Entity_Id;
2672 procedure Add_Return (S : List_Id);
2673 -- Append a return statement to the statement sequence S if the last
2674 -- statement is not already a return or a goto statement. Note that
2675 -- the latter test is not critical, it does not matter if we add a
2676 -- few extra returns, since they get eliminated anyway later on.
2682 procedure Add_Return (S : List_Id) is
2683 Last_S : constant Node_Id := Last (S);
2684 -- Get original node, in case raise has been rewritten
2687 if not Is_Transfer (Last_S) then
2688 Append_To (S, Make_Return_Statement (Sloc (Last_S)));
2692 -- Start of processing for Expand_N_Subprogram_Body
2695 -- Set L to either the list of declarations if present, or
2696 -- to the list of statements if no declarations are present.
2697 -- This is used to insert new stuff at the start.
2699 if Is_Non_Empty_List (Declarations (N)) then
2700 L := Declarations (N);
2702 L := Statements (Handled_Statement_Sequence (N));
2705 -- Need poll on entry to subprogram if polling enabled. We only
2706 -- do this for non-empty subprograms, since it does not seem
2707 -- necessary to poll for a dummy null subprogram.
2709 if Is_Non_Empty_List (L) then
2710 Generate_Poll_Call (First (L));
2713 -- Find entity for subprogram
2715 if Present (Corresponding_Spec (N)) then
2716 Spec_Id := Corresponding_Spec (N);
2718 Spec_Id := Defining_Entity (N);
2721 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
2723 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
2725 F : Entity_Id := First_Formal (Spec_Id);
2726 V : constant Boolean := Validity_Checks_On;
2729 -- We turn off validity checking, since we do not want any
2730 -- check on the initializing value itself (which we know
2731 -- may well be invalid!)
2733 Validity_Checks_On := False;
2735 -- Loop through formals
2737 while Present (F) loop
2738 if Is_Scalar_Type (Etype (F))
2739 and then Ekind (F) = E_Out_Parameter
2741 Insert_Before_And_Analyze (First (L),
2742 Make_Assignment_Statement (Loc,
2743 Name => New_Occurrence_Of (F, Loc),
2744 Expression => Get_Simple_Init_Val (Etype (F), Loc)));
2750 Validity_Checks_On := V;
2754 -- Clear out statement list for stubbed procedure
2756 if Present (Corresponding_Spec (N)) then
2757 Set_Elaboration_Flag (N, Spec_Id);
2759 if Convention (Spec_Id) = Convention_Stubbed
2760 or else Is_Eliminated (Spec_Id)
2762 Set_Declarations (N, Empty_List);
2763 Set_Handled_Statement_Sequence (N,
2764 Make_Handled_Sequence_Of_Statements (Loc,
2765 Statements => New_List (
2766 Make_Null_Statement (Loc))));
2771 Scop := Scope (Spec_Id);
2773 -- Returns_By_Ref flag is normally set when the subprogram is frozen
2774 -- but subprograms with no specs are not frozen
2777 Typ : constant Entity_Id := Etype (Spec_Id);
2778 Utyp : constant Entity_Id := Underlying_Type (Typ);
2781 if not Acts_As_Spec (N)
2782 and then Nkind (Parent (Parent (Spec_Id))) /=
2783 N_Subprogram_Body_Stub
2787 elsif Is_Return_By_Reference_Type (Typ) then
2788 Set_Returns_By_Ref (Spec_Id);
2790 elsif Present (Utyp) and then Controlled_Type (Utyp) then
2791 Set_Returns_By_Ref (Spec_Id);
2795 -- For a procedure, we add a return for all possible syntactic ends
2796 -- of the subprogram. Note that reanalysis is not necessary in this
2797 -- case since it would require a lot of work and accomplish nothing.
2799 if Ekind (Spec_Id) = E_Procedure
2800 or else Ekind (Spec_Id) = E_Generic_Procedure
2802 Add_Return (Statements (H));
2804 if Present (Exception_Handlers (H)) then
2805 Except_H := First_Non_Pragma (Exception_Handlers (H));
2807 while Present (Except_H) loop
2808 Add_Return (Statements (Except_H));
2809 Next_Non_Pragma (Except_H);
2813 -- For a function, we must deal with the case where there is at
2814 -- least one missing return. What we do is to wrap the entire body
2815 -- of the function in a block:
2828 -- raise Program_Error;
2831 -- This approach is necessary because the raise must be signalled
2832 -- to the caller, not handled by any local handler (RM 6.4(11)).
2834 -- Note: we do not need to analyze the constructed sequence here,
2835 -- since it has no handler, and an attempt to analyze the handled
2836 -- statement sequence twice is risky in various ways (e.g. the
2837 -- issue of expanding cleanup actions twice).
2839 elsif Has_Missing_Return (Spec_Id) then
2841 Hloc : constant Source_Ptr := Sloc (H);
2842 Blok : constant Node_Id :=
2843 Make_Block_Statement (Hloc,
2844 Handled_Statement_Sequence => H);
2845 Rais : constant Node_Id :=
2846 Make_Raise_Program_Error (Hloc);
2849 Set_Handled_Statement_Sequence (N,
2850 Make_Handled_Sequence_Of_Statements (Hloc,
2851 Statements => New_List (Blok, Rais)));
2853 New_Scope (Spec_Id);
2860 -- Add discriminal renamings to protected subprograms.
2861 -- Install new discriminals for expansion of the next
2862 -- subprogram of this protected type, if any.
2864 if Is_List_Member (N)
2865 and then Present (Parent (List_Containing (N)))
2866 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
2868 Add_Discriminal_Declarations
2869 (Declarations (N), Scop, Name_uObject, Loc);
2870 Add_Private_Declarations (Declarations (N), Scop, Name_uObject, Loc);
2872 -- Associate privals and discriminals with the next protected
2873 -- operation body to be expanded. These are used to expand
2874 -- references to private data objects and discriminants,
2877 Next_Op := Next_Protected_Operation (N);
2879 if Present (Next_Op) then
2880 Dec := Parent (Base_Type (Scop));
2881 Set_Privals (Dec, Next_Op, Loc);
2882 Set_Discriminals (Dec, Next_Op, Loc);
2887 -- If subprogram contains a parameterless recursive call, then we may
2888 -- have an infinite recursion, so see if we can generate code to check
2889 -- for this possibility if storage checks are not suppressed.
2891 if Ekind (Spec_Id) = E_Procedure
2892 and then Has_Recursive_Call (Spec_Id)
2893 and then not Storage_Checks_Suppressed (Spec_Id)
2895 Detect_Infinite_Recursion (N, Spec_Id);
2898 -- Finally, if we are in Normalize_Scalars mode, then any scalar out
2899 -- parameters must be initialized to the appropriate default value.
2901 if Ekind (Spec_Id) = E_Procedure and then Normalize_Scalars then
2908 Formal := First_Formal (Spec_Id);
2910 while Present (Formal) loop
2911 Floc := Sloc (Formal);
2913 if Ekind (Formal) = E_Out_Parameter
2914 and then Is_Scalar_Type (Etype (Formal))
2917 Make_Assignment_Statement (Floc,
2918 Name => New_Occurrence_Of (Formal, Floc),
2920 Get_Simple_Init_Val (Etype (Formal), Floc));
2921 Prepend (Stm, Declarations (N));
2925 Next_Formal (Formal);
2930 -- If the subprogram does not have pending instantiations, then we
2931 -- must generate the subprogram descriptor now, since the code for
2932 -- the subprogram is complete, and this is our last chance. However
2933 -- if there are pending instantiations, then the code is not
2934 -- complete, and we will delay the generation.
2936 if Is_Subprogram (Spec_Id)
2937 and then not Delay_Subprogram_Descriptors (Spec_Id)
2939 Generate_Subprogram_Descriptor_For_Subprogram (N, Spec_Id);
2942 -- Set to encode entity names in package body before gigi is called
2944 Qualify_Entity_Names (N);
2945 end Expand_N_Subprogram_Body;
2947 -----------------------------------
2948 -- Expand_N_Subprogram_Body_Stub --
2949 -----------------------------------
2951 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
2953 if Present (Corresponding_Body (N)) then
2954 Expand_N_Subprogram_Body (
2955 Unit_Declaration_Node (Corresponding_Body (N)));
2958 end Expand_N_Subprogram_Body_Stub;
2960 -------------------------------------
2961 -- Expand_N_Subprogram_Declaration --
2962 -------------------------------------
2964 -- The first task to be performed is the construction of default
2965 -- expression functions for in parameters with default values. These
2966 -- are parameterless inlined functions that are used to evaluate
2967 -- default expressions that are more complicated than simple literals
2968 -- or identifiers referencing constants and variables.
2970 -- If the declaration appears within a protected body, it is a private
2971 -- operation of the protected type. We must create the corresponding
2972 -- protected subprogram an associated formals. For a normal protected
2973 -- operation, this is done when expanding the protected type declaration.
2975 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
2976 Loc : constant Source_Ptr := Sloc (N);
2977 Subp : Entity_Id := Defining_Entity (N);
2978 Scop : Entity_Id := Scope (Subp);
2979 Prot_Sub : Entity_Id;
2983 -- Deal with case of protected subprogram
2985 if Is_List_Member (N)
2986 and then Present (Parent (List_Containing (N)))
2987 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
2988 and then Is_Protected_Type (Scop)
2990 if No (Protected_Body_Subprogram (Subp)) then
2992 Make_Subprogram_Declaration (Loc,
2994 Build_Protected_Sub_Specification
2995 (N, Scop, Unprotected => True));
2997 -- The protected subprogram is declared outside of the protected
2998 -- body. Given that the body has frozen all entities so far, we
2999 -- freeze the subprogram explicitly. If the body is a subunit,
3000 -- the insertion point is before the stub in the parent.
3002 Prot_Bod := Parent (List_Containing (N));
3004 if Nkind (Parent (Prot_Bod)) = N_Subunit then
3005 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
3008 Insert_Before (Prot_Bod, Prot_Sub);
3010 New_Scope (Scope (Scop));
3012 Set_Protected_Body_Subprogram (Subp,
3013 Defining_Unit_Name (Specification (Prot_Sub)));
3017 end Expand_N_Subprogram_Declaration;
3019 ---------------------------------------
3020 -- Expand_Protected_Object_Reference --
3021 ---------------------------------------
3023 function Expand_Protected_Object_Reference
3028 Loc : constant Source_Ptr := Sloc (N);
3035 Rec := Make_Identifier (Loc, Name_uObject);
3036 Set_Etype (Rec, Corresponding_Record_Type (Scop));
3038 -- Find enclosing protected operation, and retrieve its first
3039 -- parameter, which denotes the enclosing protected object.
3040 -- If the enclosing operation is an entry, we are immediately
3041 -- within the protected body, and we can retrieve the object
3042 -- from the service entries procedure. A barrier function has
3043 -- has the same signature as an entry. A barrier function is
3044 -- compiled within the protected object, but unlike protected
3045 -- operations its never needs locks, so that its protected body
3046 -- subprogram points to itself.
3048 Proc := Current_Scope;
3050 while Present (Proc)
3051 and then Scope (Proc) /= Scop
3053 Proc := Scope (Proc);
3056 Corr := Protected_Body_Subprogram (Proc);
3060 -- Previous error left expansion incomplete.
3061 -- Nothing to do on this call.
3068 (First (Parameter_Specifications (Parent (Corr))));
3070 if Is_Subprogram (Proc)
3071 and then Proc /= Corr
3073 -- Protected function or procedure.
3075 Set_Entity (Rec, Param);
3077 -- Rec is a reference to an entity which will not be in scope
3078 -- when the call is reanalyzed, and needs no further analysis.
3083 -- Entry or barrier function for entry body.
3084 -- The first parameter of the entry body procedure is a
3085 -- pointer to the object. We create a local variable
3086 -- of the proper type, duplicating what is done to define
3087 -- _object later on.
3091 Obj_Ptr : Entity_Id := Make_Defining_Identifier
3092 (Loc, New_Internal_Name ('T'));
3095 Make_Full_Type_Declaration (Loc,
3096 Defining_Identifier => Obj_Ptr,
3098 Make_Access_To_Object_Definition (Loc,
3099 Subtype_Indication =>
3101 (Corresponding_Record_Type (Scop), Loc))));
3103 Insert_Actions (N, Decls);
3104 Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
3107 Make_Explicit_Dereference (Loc,
3108 Unchecked_Convert_To (Obj_Ptr,
3109 New_Occurrence_Of (Param, Loc)));
3111 -- Analyze new actual. Other actuals in calls are already
3112 -- analyzed and the list of actuals is not renalyzed after
3115 Set_Parent (Rec, N);
3121 end Expand_Protected_Object_Reference;
3123 --------------------------------------
3124 -- Expand_Protected_Subprogram_Call --
3125 --------------------------------------
3127 procedure Expand_Protected_Subprogram_Call
3135 -- If the protected object is not an enclosing scope, this is
3136 -- an inter-object function call. Inter-object procedure
3137 -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
3138 -- The call is intra-object only if the subprogram being
3139 -- called is in the protected body being compiled, and if the
3140 -- protected object in the call is statically the enclosing type.
3141 -- The object may be an component of some other data structure,
3142 -- in which case this must be handled as an inter-object call.
3144 if not In_Open_Scopes (Scop)
3145 or else not Is_Entity_Name (Name (N))
3147 if Nkind (Name (N)) = N_Selected_Component then
3148 Rec := Prefix (Name (N));
3151 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
3152 Rec := Prefix (Prefix (Name (N)));
3155 Build_Protected_Subprogram_Call (N,
3156 Name => New_Occurrence_Of (Subp, Sloc (N)),
3157 Rec => Convert_Concurrent (Rec, Etype (Rec)),
3161 Rec := Expand_Protected_Object_Reference (N, Scop);
3167 Build_Protected_Subprogram_Call (N,
3176 -- If it is a function call it can appear in elaboration code and
3177 -- the called entity must be frozen here.
3179 if Ekind (Subp) = E_Function then
3180 Freeze_Expression (Name (N));
3182 end Expand_Protected_Subprogram_Call;
3184 -----------------------
3185 -- Freeze_Subprogram --
3186 -----------------------
3188 procedure Freeze_Subprogram (N : Node_Id) is
3189 E : constant Entity_Id := Entity (N);
3192 -- When a primitive is frozen, enter its name in the corresponding
3193 -- dispatch table. If the DTC_Entity field is not set this is an
3194 -- overridden primitive that can be ignored. We suppress the
3195 -- initialization of the dispatch table entry when Java_VM because
3196 -- the dispatching mechanism is handled internally by the JVM.
3198 if Is_Dispatching_Operation (E)
3199 and then not Is_Abstract (E)
3200 and then Present (DTC_Entity (E))
3201 and then not Is_CPP_Class (Scope (DTC_Entity (E)))
3202 and then not Java_VM
3204 Check_Overriding_Operation (E);
3205 Insert_After (N, Fill_DT_Entry (Sloc (N), E));
3208 -- Mark functions that return by reference. Note that it cannot be
3209 -- part of the normal semantic analysis of the spec since the
3210 -- underlying returned type may not be known yet (for private types)
3213 Typ : constant Entity_Id := Etype (E);
3214 Utyp : constant Entity_Id := Underlying_Type (Typ);
3217 if Is_Return_By_Reference_Type (Typ) then
3218 Set_Returns_By_Ref (E);
3220 elsif Present (Utyp) and then Controlled_Type (Utyp) then
3221 Set_Returns_By_Ref (E);
3225 end Freeze_Subprogram;
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