1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Elists; use Elists;
33 with Exp_Ch2; use Exp_Ch2;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Ch11; use Exp_Ch11;
38 with Exp_Dbug; use Exp_Dbug;
39 with Exp_Disp; use Exp_Disp;
40 with Exp_Dist; use Exp_Dist;
41 with Exp_Intr; use Exp_Intr;
42 with Exp_Pakd; use Exp_Pakd;
43 with Exp_Tss; use Exp_Tss;
44 with Exp_Util; use Exp_Util;
45 with Fname; use Fname;
46 with Freeze; use Freeze;
47 with Hostparm; use Hostparm;
48 with Inline; use Inline;
50 with Nlists; use Nlists;
51 with Nmake; use Nmake;
53 with Restrict; use Restrict;
54 with Rident; use Rident;
55 with Rtsfind; use Rtsfind;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Ch12; use Sem_Ch12;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_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 Ttypes; use Ttypes;
70 with Uintp; use Uintp;
71 with Validsw; use Validsw;
73 package body Exp_Ch6 is
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
79 procedure Check_Overriding_Operation (Subp : Entity_Id);
80 -- Subp is a dispatching operation. Check whether it may override an
81 -- inherited private operation, in which case its DT entry is that of
82 -- the hidden operation, not the one it may have received earlier.
83 -- This must be done before emitting the code to set the corresponding
84 -- DT to the address of the subprogram. The actual placement of Subp in
85 -- the proper place in the list of primitive operations is done in
86 -- Declare_Inherited_Private_Subprograms, which also has to deal with
87 -- implicit operations. This duplication is unavoidable for now???
89 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
90 -- This procedure is called only if the subprogram body N, whose spec
91 -- has the given entity Spec, contains a parameterless recursive call.
92 -- It attempts to generate runtime code to detect if this a case of
93 -- infinite recursion.
95 -- The body is scanned to determine dependencies. If the only external
96 -- dependencies are on a small set of scalar variables, then the values
97 -- of these variables are captured on entry to the subprogram, and if
98 -- the values are not changed for the call, we know immediately that
99 -- we have an infinite recursion.
101 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id);
102 -- For each actual of an in-out parameter which is a numeric conversion
103 -- of the form T(A), where A denotes a variable, we insert the declaration:
105 -- Temp : T := T (A);
107 -- prior to the call. Then we replace the actual with a reference to Temp,
108 -- and append the assignment:
110 -- A := TypeA (Temp);
112 -- after the call. Here TypeA is the actual type of variable A.
113 -- For out parameters, the initial declaration has no expression.
114 -- If A is not an entity name, we generate instead:
116 -- Var : TypeA renames A;
117 -- Temp : T := Var; -- omitting expression for out parameter.
119 -- Var := TypeA (Temp);
121 -- For other in-out parameters, we emit the required constraint checks
122 -- before and/or after the call.
124 -- For all parameter modes, actuals that denote components and slices
125 -- of packed arrays are expanded into suitable temporaries.
127 -- For non-scalar objects that are possibly unaligned, add call by copy
128 -- code (copy in for IN and IN OUT, copy out for OUT and IN OUT).
130 procedure Expand_Inlined_Call
133 Orig_Subp : Entity_Id);
134 -- If called subprogram can be inlined by the front-end, retrieve the
135 -- analyzed body, replace formals with actuals and expand call in place.
136 -- Generate thunks for actuals that are expressions, and insert the
137 -- corresponding constant declarations before the call. If the original
138 -- call is to a derived operation, the return type is the one of the
139 -- derived operation, but the body is that of the original, so return
140 -- expressions in the body must be converted to the desired type (which
141 -- is simply not noted in the tree without inline expansion).
143 function Expand_Protected_Object_Reference
148 procedure Expand_Protected_Subprogram_Call
152 -- A call to a protected subprogram within the protected object may appear
153 -- as a regular call. The list of actuals must be expanded to contain a
154 -- reference to the object itself, and the call becomes a call to the
155 -- corresponding protected subprogram.
157 --------------------------------
158 -- Check_Overriding_Operation --
159 --------------------------------
161 procedure Check_Overriding_Operation (Subp : Entity_Id) is
162 Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
163 Op_List : constant Elist_Id := Primitive_Operations (Typ);
169 if Is_Derived_Type (Typ)
170 and then not Is_Private_Type (Typ)
171 and then In_Open_Scopes (Scope (Etype (Typ)))
172 and then Typ = Base_Type (Typ)
174 -- Subp overrides an inherited private operation if there is
175 -- an inherited operation with a different name than Subp (see
176 -- Derive_Subprogram) whose Alias is a hidden subprogram with
177 -- the same name as Subp.
179 Op_Elmt := First_Elmt (Op_List);
180 while Present (Op_Elmt) loop
181 Prim_Op := Node (Op_Elmt);
182 Par_Op := Alias (Prim_Op);
185 and then not Comes_From_Source (Prim_Op)
186 and then Chars (Prim_Op) /= Chars (Par_Op)
187 and then Chars (Par_Op) = Chars (Subp)
188 and then Is_Hidden (Par_Op)
189 and then Type_Conformant (Prim_Op, Subp)
191 Set_DT_Position (Subp, DT_Position (Prim_Op));
197 end Check_Overriding_Operation;
199 -------------------------------
200 -- Detect_Infinite_Recursion --
201 -------------------------------
203 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
204 Loc : constant Source_Ptr := Sloc (N);
206 Var_List : constant Elist_Id := New_Elmt_List;
207 -- List of globals referenced by body of procedure
209 Call_List : constant Elist_Id := New_Elmt_List;
210 -- List of recursive calls in body of procedure
212 Shad_List : constant Elist_Id := New_Elmt_List;
213 -- List of entity id's for entities created to capture the
214 -- value of referenced globals on entry to the procedure.
216 Scop : constant Uint := Scope_Depth (Spec);
217 -- This is used to record the scope depth of the current
218 -- procedure, so that we can identify global references.
220 Max_Vars : constant := 4;
221 -- Do not test more than four global variables
223 Count_Vars : Natural := 0;
224 -- Count variables found so far
236 function Process (Nod : Node_Id) return Traverse_Result;
237 -- Function to traverse the subprogram body (using Traverse_Func)
243 function Process (Nod : Node_Id) return Traverse_Result is
247 if Nkind (Nod) = N_Procedure_Call_Statement then
249 -- Case of one of the detected recursive calls
251 if Is_Entity_Name (Name (Nod))
252 and then Has_Recursive_Call (Entity (Name (Nod)))
253 and then Entity (Name (Nod)) = Spec
255 Append_Elmt (Nod, Call_List);
258 -- Any other procedure call may have side effects
264 -- A call to a pure function can always be ignored
266 elsif Nkind (Nod) = N_Function_Call
267 and then Is_Entity_Name (Name (Nod))
268 and then Is_Pure (Entity (Name (Nod)))
272 -- Case of an identifier reference
274 elsif Nkind (Nod) = N_Identifier then
277 -- If no entity, then ignore the reference
279 -- Not clear why this can happen. To investigate, remove this
280 -- test and look at the crash that occurs here in 3401-004 ???
285 -- Ignore entities with no Scope, again not clear how this
286 -- can happen, to investigate, look at 4108-008 ???
288 elsif No (Scope (Ent)) then
291 -- Ignore the reference if not to a more global object
293 elsif Scope_Depth (Scope (Ent)) >= Scop then
296 -- References to types, exceptions and constants are always OK
299 or else Ekind (Ent) = E_Exception
300 or else Ekind (Ent) = E_Constant
304 -- If other than a non-volatile scalar variable, we have some
305 -- kind of global reference (e.g. to a function) that we cannot
306 -- deal with so we forget the attempt.
308 elsif Ekind (Ent) /= E_Variable
309 or else not Is_Scalar_Type (Etype (Ent))
310 or else Treat_As_Volatile (Ent)
314 -- Otherwise we have a reference to a global scalar
317 -- Loop through global entities already detected
319 Elm := First_Elmt (Var_List);
321 -- If not detected before, record this new global reference
324 Count_Vars := Count_Vars + 1;
326 if Count_Vars <= Max_Vars then
327 Append_Elmt (Entity (Nod), Var_List);
334 -- If recorded before, ignore
336 elsif Node (Elm) = Entity (Nod) then
339 -- Otherwise keep looking
349 -- For all other node kinds, recursively visit syntactic children
356 function Traverse_Body is new Traverse_Func;
358 -- Start of processing for Detect_Infinite_Recursion
361 -- Do not attempt detection in No_Implicit_Conditional mode,
362 -- since we won't be able to generate the code to handle the
363 -- recursion in any case.
365 if Restriction_Active (No_Implicit_Conditionals) then
369 -- Otherwise do traversal and quit if we get abandon signal
371 if Traverse_Body (N) = Abandon then
374 -- We must have a call, since Has_Recursive_Call was set. If not
375 -- just ignore (this is only an error check, so if we have a funny
376 -- situation, due to bugs or errors, we do not want to bomb!)
378 elsif Is_Empty_Elmt_List (Call_List) then
382 -- Here is the case where we detect recursion at compile time
384 -- Push our current scope for analyzing the declarations and
385 -- code that we will insert for the checking.
389 -- This loop builds temporary variables for each of the
390 -- referenced globals, so that at the end of the loop the
391 -- list Shad_List contains these temporaries in one-to-one
392 -- correspondence with the elements in Var_List.
395 Elm := First_Elmt (Var_List);
396 while Present (Elm) loop
399 Make_Defining_Identifier (Loc,
400 Chars => New_Internal_Name ('S'));
401 Append_Elmt (Ent, Shad_List);
403 -- Insert a declaration for this temporary at the start of
404 -- the declarations for the procedure. The temporaries are
405 -- declared as constant objects initialized to the current
406 -- values of the corresponding temporaries.
409 Make_Object_Declaration (Loc,
410 Defining_Identifier => Ent,
411 Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
412 Constant_Present => True,
413 Expression => New_Occurrence_Of (Var, Loc));
416 Prepend (Decl, Declarations (N));
418 Insert_After (Last, Decl);
426 -- Loop through calls
428 Call := First_Elmt (Call_List);
429 while Present (Call) loop
431 -- Build a predicate expression of the form
434 -- and then global1 = temp1
435 -- and then global2 = temp2
438 -- This predicate determines if any of the global values
439 -- referenced by the procedure have changed since the
440 -- current call, if not an infinite recursion is assured.
442 Test := New_Occurrence_Of (Standard_True, Loc);
444 Elm1 := First_Elmt (Var_List);
445 Elm2 := First_Elmt (Shad_List);
446 while Present (Elm1) loop
452 Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
453 Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
459 -- Now we replace the call with the sequence
461 -- if no-changes (see above) then
462 -- raise Storage_Error;
467 Rewrite (Node (Call),
468 Make_If_Statement (Loc,
470 Then_Statements => New_List (
471 Make_Raise_Storage_Error (Loc,
472 Reason => SE_Infinite_Recursion)),
474 Else_Statements => New_List (
475 Relocate_Node (Node (Call)))));
477 Analyze (Node (Call));
482 -- Remove temporary scope stack entry used for analysis
485 end Detect_Infinite_Recursion;
491 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id) is
492 Loc : constant Source_Ptr := Sloc (N);
497 E_Formal : Entity_Id;
499 procedure Add_Call_By_Copy_Code;
500 -- For cases where the parameter must be passed by copy, this routine
501 -- generates a temporary variable into which the actual is copied and
502 -- then passes this as the parameter. For an OUT or IN OUT parameter,
503 -- an assignment is also generated to copy the result back. The call
504 -- also takes care of any constraint checks required for the type
505 -- conversion case (on both the way in and the way out).
507 procedure Add_Simple_Call_By_Copy_Code;
508 -- This is similar to the above, but is used in cases where we know
509 -- that all that is needed is to simply create a temporary and copy
510 -- the value in and out of the temporary.
512 procedure Check_Fortran_Logical;
513 -- A value of type Logical that is passed through a formal parameter
514 -- must be normalized because .TRUE. usually does not have the same
515 -- representation as True. We assume that .FALSE. = False = 0.
516 -- What about functions that return a logical type ???
518 function Make_Var (Actual : Node_Id) return Entity_Id;
519 -- Returns an entity that refers to the given actual parameter,
520 -- Actual (not including any type conversion). If Actual is an
521 -- entity name, then this entity is returned unchanged, otherwise
522 -- a renaming is created to provide an entity for the actual.
524 procedure Reset_Packed_Prefix;
525 -- The expansion of a packed array component reference is delayed in
526 -- the context of a call. Now we need to complete the expansion, so we
527 -- unmark the analyzed bits in all prefixes.
529 ---------------------------
530 -- Add_Call_By_Copy_Code --
531 ---------------------------
533 procedure Add_Call_By_Copy_Code is
539 F_Typ : constant Entity_Id := Etype (Formal);
544 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
546 -- Use formal type for temp, unless formal type is an unconstrained
547 -- array, in which case we don't have to worry about bounds checks,
548 -- and we use the actual type, since that has appropriate bonds.
550 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
551 Indic := New_Occurrence_Of (Etype (Actual), Loc);
553 Indic := New_Occurrence_Of (Etype (Formal), Loc);
557 if Nkind (Actual) = N_Type_Conversion then
558 V_Typ := Etype (Expression (Actual));
560 -- If the formal is an (in-)out parameter, capture the name
561 -- of the variable in order to build the post-call assignment.
563 Var := Make_Var (Expression (Actual));
565 Crep := not Same_Representation
566 (F_Typ, Etype (Expression (Actual)));
569 V_Typ := Etype (Actual);
570 Var := Make_Var (Actual);
574 -- Setup initialization for case of in out parameter, or an out
575 -- parameter where the formal is an unconstrained array (in the
576 -- latter case, we have to pass in an object with bounds).
578 -- If this is an out parameter, the initial copy is wasteful, so as
579 -- an optimization for the one-dimensional case we extract the
580 -- bounds of the actual and build an uninitialized temporary of the
583 if Ekind (Formal) = E_In_Out_Parameter
584 or else (Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ))
586 if Nkind (Actual) = N_Type_Conversion then
587 if Conversion_OK (Actual) then
588 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
590 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
593 elsif Ekind (Formal) = E_Out_Parameter
594 and then Is_Array_Type (F_Typ)
595 and then Number_Dimensions (F_Typ) = 1
596 and then not Has_Non_Null_Base_Init_Proc (F_Typ)
598 -- Actual is a one-dimensional array or slice, and the type
599 -- requires no initialization. Create a temporary of the
600 -- right size, but do not copy actual into it (optimization).
604 Make_Subtype_Indication (Loc,
606 New_Occurrence_Of (F_Typ, Loc),
608 Make_Index_Or_Discriminant_Constraint (Loc,
609 Constraints => New_List (
612 Make_Attribute_Reference (Loc,
613 Prefix => New_Occurrence_Of (Var, Loc),
614 Attribute_name => Name_First),
616 Make_Attribute_Reference (Loc,
617 Prefix => New_Occurrence_Of (Var, Loc),
618 Attribute_Name => Name_Last)))));
621 Init := New_Occurrence_Of (Var, Loc);
624 -- An initialization is created for packed conversions as
625 -- actuals for out parameters to enable Make_Object_Declaration
626 -- to determine the proper subtype for N_Node. Note that this
627 -- is wasteful because the extra copying on the call side is
628 -- not required for such out parameters. ???
630 elsif Ekind (Formal) = E_Out_Parameter
631 and then Nkind (Actual) = N_Type_Conversion
632 and then (Is_Bit_Packed_Array (F_Typ)
634 Is_Bit_Packed_Array (Etype (Expression (Actual))))
636 if Conversion_OK (Actual) then
637 Init := OK_Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
639 Init := Convert_To (F_Typ, New_Occurrence_Of (Var, Loc));
642 elsif Ekind (Formal) = E_In_Parameter then
643 Init := New_Occurrence_Of (Var, Loc);
650 Make_Object_Declaration (Loc,
651 Defining_Identifier => Temp,
652 Object_Definition => Indic,
654 Set_Assignment_OK (N_Node);
655 Insert_Action (N, N_Node);
657 -- Now, normally the deal here is that we use the defining
658 -- identifier created by that object declaration. There is
659 -- one exception to this. In the change of representation case
660 -- the above declaration will end up looking like:
662 -- temp : type := identifier;
664 -- And in this case we might as well use the identifier directly
665 -- and eliminate the temporary. Note that the analysis of the
666 -- declaration was not a waste of time in that case, since it is
667 -- what generated the necessary change of representation code. If
668 -- the change of representation introduced additional code, as in
669 -- a fixed-integer conversion, the expression is not an identifier
673 and then Present (Expression (N_Node))
674 and then Is_Entity_Name (Expression (N_Node))
676 Temp := Entity (Expression (N_Node));
677 Rewrite (N_Node, Make_Null_Statement (Loc));
680 -- For IN parameter, all we do is to replace the actual
682 if Ekind (Formal) = E_In_Parameter then
683 Rewrite (Actual, New_Reference_To (Temp, Loc));
686 -- Processing for OUT or IN OUT parameter
689 -- If type conversion, use reverse conversion on exit
691 if Nkind (Actual) = N_Type_Conversion then
692 if Conversion_OK (Actual) then
693 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
695 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
698 Expr := New_Occurrence_Of (Temp, Loc);
701 Rewrite (Actual, New_Reference_To (Temp, Loc));
704 Append_To (Post_Call,
705 Make_Assignment_Statement (Loc,
706 Name => New_Occurrence_Of (Var, Loc),
707 Expression => Expr));
709 Set_Assignment_OK (Name (Last (Post_Call)));
711 end Add_Call_By_Copy_Code;
713 ----------------------------------
714 -- Add_Simple_Call_By_Copy_Code --
715 ----------------------------------
717 procedure Add_Simple_Call_By_Copy_Code is
724 F_Typ : constant Entity_Id := Etype (Formal);
727 -- Use formal type for temp, unless formal type is an unconstrained
728 -- array, in which case we don't have to worry about bounds checks,
729 -- and we use the actual type, since that has appropriate bonds.
731 if Is_Array_Type (F_Typ) and then not Is_Constrained (F_Typ) then
732 Indic := New_Occurrence_Of (Etype (Actual), Loc);
734 Indic := New_Occurrence_Of (Etype (Formal), Loc);
737 -- Prepare to generate code
741 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
742 Incod := Relocate_Node (Actual);
743 Outcod := New_Copy_Tree (Incod);
745 -- Generate declaration of temporary variable, initializing it
746 -- with the input parameter unless we have an OUT variable.
748 if Ekind (Formal) = E_Out_Parameter then
753 Make_Object_Declaration (Loc,
754 Defining_Identifier => Temp,
755 Object_Definition => Indic,
756 Expression => Incod));
758 -- The actual is simply a reference to the temporary
760 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
762 -- Generate copy out if OUT or IN OUT parameter
764 if Ekind (Formal) /= E_In_Parameter then
766 Rhs := New_Occurrence_Of (Temp, Loc);
768 -- Deal with conversion
770 if Nkind (Lhs) = N_Type_Conversion then
771 Lhs := Expression (Lhs);
772 Rhs := Convert_To (Etype (Actual), Rhs);
775 Append_To (Post_Call,
776 Make_Assignment_Statement (Loc,
779 Set_Assignment_OK (Name (Last (Post_Call)));
781 end Add_Simple_Call_By_Copy_Code;
783 ---------------------------
784 -- Check_Fortran_Logical --
785 ---------------------------
787 procedure Check_Fortran_Logical is
788 Logical : constant Entity_Id := Etype (Formal);
791 -- Note: this is very incomplete, e.g. it does not handle arrays
792 -- of logical values. This is really not the right approach at all???)
795 if Convention (Subp) = Convention_Fortran
796 and then Root_Type (Etype (Formal)) = Standard_Boolean
797 and then Ekind (Formal) /= E_In_Parameter
799 Var := Make_Var (Actual);
800 Append_To (Post_Call,
801 Make_Assignment_Statement (Loc,
802 Name => New_Occurrence_Of (Var, Loc),
804 Unchecked_Convert_To (
807 Left_Opnd => New_Occurrence_Of (Var, Loc),
809 Unchecked_Convert_To (
811 New_Occurrence_Of (Standard_False, Loc))))));
813 end Check_Fortran_Logical;
819 function Make_Var (Actual : Node_Id) return Entity_Id is
823 if Is_Entity_Name (Actual) then
824 return Entity (Actual);
827 Var := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
830 Make_Object_Renaming_Declaration (Loc,
831 Defining_Identifier => Var,
833 New_Occurrence_Of (Etype (Actual), Loc),
834 Name => Relocate_Node (Actual));
836 Insert_Action (N, N_Node);
841 -------------------------
842 -- Reset_Packed_Prefix --
843 -------------------------
845 procedure Reset_Packed_Prefix is
846 Pfx : Node_Id := Actual;
850 Set_Analyzed (Pfx, False);
851 exit when Nkind (Pfx) /= N_Selected_Component
852 and then Nkind (Pfx) /= N_Indexed_Component;
855 end Reset_Packed_Prefix;
857 -- Start of processing for Expand_Actuals
860 Formal := First_Formal (Subp);
861 Actual := First_Actual (N);
863 Post_Call := New_List;
865 while Present (Formal) loop
866 E_Formal := Etype (Formal);
868 if Is_Scalar_Type (E_Formal)
869 or else Nkind (Actual) = N_Slice
871 Check_Fortran_Logical;
875 elsif Ekind (Formal) /= E_Out_Parameter then
877 -- The unusual case of the current instance of a protected type
878 -- requires special handling. This can only occur in the context
879 -- of a call within the body of a protected operation.
881 if Is_Entity_Name (Actual)
882 and then Ekind (Entity (Actual)) = E_Protected_Type
883 and then In_Open_Scopes (Entity (Actual))
885 if Scope (Subp) /= Entity (Actual) then
886 Error_Msg_N ("operation outside protected type may not "
887 & "call back its protected operations?", Actual);
891 Expand_Protected_Object_Reference (N, Entity (Actual)));
894 Apply_Constraint_Check (Actual, E_Formal);
896 -- Out parameter case. No constraint checks on access type
899 elsif Is_Access_Type (E_Formal) then
904 elsif Has_Discriminants (Base_Type (E_Formal))
905 or else Has_Non_Null_Base_Init_Proc (E_Formal)
907 Apply_Constraint_Check (Actual, E_Formal);
912 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
915 -- Processing for IN-OUT and OUT parameters
917 if Ekind (Formal) /= E_In_Parameter then
919 -- For type conversions of arrays, apply length/range checks
921 if Is_Array_Type (E_Formal)
922 and then Nkind (Actual) = N_Type_Conversion
924 if Is_Constrained (E_Formal) then
925 Apply_Length_Check (Expression (Actual), E_Formal);
927 Apply_Range_Check (Expression (Actual), E_Formal);
931 -- If argument is a type conversion for a type that is passed
932 -- by copy, then we must pass the parameter by copy.
934 if Nkind (Actual) = N_Type_Conversion
936 (Is_Numeric_Type (E_Formal)
937 or else Is_Access_Type (E_Formal)
938 or else Is_Enumeration_Type (E_Formal)
939 or else Is_Bit_Packed_Array (Etype (Formal))
940 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
942 -- Also pass by copy if change of representation
944 or else not Same_Representation
946 Etype (Expression (Actual))))
948 Add_Call_By_Copy_Code;
950 -- References to components of bit packed arrays are expanded
951 -- at this point, rather than at the point of analysis of the
952 -- actuals, to handle the expansion of the assignment to
953 -- [in] out parameters.
955 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
956 Add_Simple_Call_By_Copy_Code;
958 -- If a non-scalar actual is possibly unaligned, we need a copy
960 elsif Is_Possibly_Unaligned_Object (Actual)
961 and then not Represented_As_Scalar (Etype (Formal))
963 Add_Simple_Call_By_Copy_Code;
965 -- References to slices of bit packed arrays are expanded
967 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
968 Add_Call_By_Copy_Code;
970 -- References to possibly unaligned slices of arrays are expanded
972 elsif Is_Possibly_Unaligned_Slice (Actual) then
973 Add_Call_By_Copy_Code;
975 -- Deal with access types where the actual subtpe and the
976 -- formal subtype are not the same, requiring a check.
978 -- It is necessary to exclude tagged types because of "downward
979 -- conversion" errors and a strange assertion error in namet
980 -- from gnatf in bug 1215-001 ???
982 elsif Is_Access_Type (E_Formal)
983 and then not Same_Type (E_Formal, Etype (Actual))
984 and then not Is_Tagged_Type (Designated_Type (E_Formal))
986 Add_Call_By_Copy_Code;
988 -- If the actual is not a scalar and is marked for volatile
989 -- treatment, whereas the formal is not volatile, then pass
990 -- by copy unless it is a by-reference type.
992 elsif Is_Entity_Name (Actual)
993 and then Treat_As_Volatile (Entity (Actual))
994 and then not Is_By_Reference_Type (Etype (Actual))
995 and then not Is_Scalar_Type (Etype (Entity (Actual)))
996 and then not Treat_As_Volatile (E_Formal)
998 Add_Call_By_Copy_Code;
1000 elsif Nkind (Actual) = N_Indexed_Component
1001 and then Is_Entity_Name (Prefix (Actual))
1002 and then Has_Volatile_Components (Entity (Prefix (Actual)))
1004 Add_Call_By_Copy_Code;
1007 -- Processing for IN parameters
1010 -- For IN parameters is in the packed array case, we expand an
1011 -- indexed component (the circuit in Exp_Ch4 deliberately left
1012 -- indexed components appearing as actuals untouched, so that
1013 -- the special processing above for the OUT and IN OUT cases
1014 -- could be performed. We could make the test in Exp_Ch4 more
1015 -- complex and have it detect the parameter mode, but it is
1016 -- easier simply to handle all cases here.)
1018 if Nkind (Actual) = N_Indexed_Component
1019 and then Is_Packed (Etype (Prefix (Actual)))
1021 Reset_Packed_Prefix;
1022 Expand_Packed_Element_Reference (Actual);
1024 -- If we have a reference to a bit packed array, we copy it,
1025 -- since the actual must be byte aligned.
1027 -- Is this really necessary in all cases???
1029 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
1030 Add_Simple_Call_By_Copy_Code;
1032 -- If a non-scalar actual is possibly unaligned, we need a copy
1034 elsif Is_Possibly_Unaligned_Object (Actual)
1035 and then not Represented_As_Scalar (Etype (Formal))
1037 Add_Simple_Call_By_Copy_Code;
1039 -- Similarly, we have to expand slices of packed arrays here
1040 -- because the result must be byte aligned.
1042 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
1043 Add_Call_By_Copy_Code;
1045 -- Only processing remaining is to pass by copy if this is a
1046 -- reference to a possibly unaligned slice, since the caller
1047 -- expects an appropriately aligned argument.
1049 elsif Is_Possibly_Unaligned_Slice (Actual) then
1050 Add_Call_By_Copy_Code;
1054 Next_Formal (Formal);
1055 Next_Actual (Actual);
1058 -- Find right place to put post call stuff if it is present
1060 if not Is_Empty_List (Post_Call) then
1062 -- If call is not a list member, it must be the triggering
1063 -- statement of a triggering alternative or an entry call
1064 -- alternative, and we can add the post call stuff to the
1065 -- corresponding statement list.
1067 if not Is_List_Member (N) then
1069 P : constant Node_Id := Parent (N);
1072 pragma Assert (Nkind (P) = N_Triggering_Alternative
1073 or else Nkind (P) = N_Entry_Call_Alternative);
1075 if Is_Non_Empty_List (Statements (P)) then
1076 Insert_List_Before_And_Analyze
1077 (First (Statements (P)), Post_Call);
1079 Set_Statements (P, Post_Call);
1083 -- Otherwise, normal case where N is in a statement sequence,
1084 -- just put the post-call stuff after the call statement.
1087 Insert_Actions_After (N, Post_Call);
1091 -- The call node itself is re-analyzed in Expand_Call
1099 -- This procedure handles expansion of function calls and procedure call
1100 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1101 -- Expand_N_Procedure_Call_Statement. Processing for calls includes:
1103 -- Replace call to Raise_Exception by Raise_Exception always if possible
1104 -- Provide values of actuals for all formals in Extra_Formals list
1105 -- Replace "call" to enumeration literal function by literal itself
1106 -- Rewrite call to predefined operator as operator
1107 -- Replace actuals to in-out parameters that are numeric conversions,
1108 -- with explicit assignment to temporaries before and after the call.
1109 -- Remove optional actuals if First_Optional_Parameter specified.
1111 -- Note that the list of actuals has been filled with default expressions
1112 -- during semantic analysis of the call. Only the extra actuals required
1113 -- for the 'Constrained attribute and for accessibility checks are added
1116 procedure Expand_Call (N : Node_Id) is
1117 Loc : constant Source_Ptr := Sloc (N);
1118 Remote : constant Boolean := Is_Remote_Call (N);
1120 Orig_Subp : Entity_Id := Empty;
1121 Parent_Subp : Entity_Id;
1122 Parent_Formal : Entity_Id;
1125 Prev : Node_Id := Empty;
1126 Prev_Orig : Node_Id;
1128 Extra_Actuals : List_Id := No_List;
1131 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1132 -- Adds one entry to the end of the actual parameter list. Used for
1133 -- default parameters and for extra actuals (for Extra_Formals).
1134 -- The argument is an N_Parameter_Association node.
1136 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1137 -- Adds an extra actual to the list of extra actuals. Expr
1138 -- is the expression for the value of the actual, EF is the
1139 -- entity for the extra formal.
1141 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1142 -- Within an instance, a type derived from a non-tagged formal derived
1143 -- type inherits from the original parent, not from the actual. This is
1144 -- tested in 4723-003. The current derivation mechanism has the derived
1145 -- type inherit from the actual, which is only correct outside of the
1146 -- instance. If the subprogram is inherited, we test for this particular
1147 -- case through a convoluted tree traversal before setting the proper
1148 -- subprogram to be called.
1150 --------------------------
1151 -- Add_Actual_Parameter --
1152 --------------------------
1154 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1155 Actual_Expr : constant Node_Id :=
1156 Explicit_Actual_Parameter (Insert_Param);
1159 -- Case of insertion is first named actual
1161 if No (Prev) or else
1162 Nkind (Parent (Prev)) /= N_Parameter_Association
1164 Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
1165 Set_First_Named_Actual (N, Actual_Expr);
1168 if not Present (Parameter_Associations (N)) then
1169 Set_Parameter_Associations (N, New_List);
1170 Append (Insert_Param, Parameter_Associations (N));
1173 Insert_After (Prev, Insert_Param);
1176 -- Case of insertion is not first named actual
1179 Set_Next_Named_Actual
1180 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1181 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1182 Append (Insert_Param, Parameter_Associations (N));
1185 Prev := Actual_Expr;
1186 end Add_Actual_Parameter;
1188 ----------------------
1189 -- Add_Extra_Actual --
1190 ----------------------
1192 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1193 Loc : constant Source_Ptr := Sloc (Expr);
1196 if Extra_Actuals = No_List then
1197 Extra_Actuals := New_List;
1198 Set_Parent (Extra_Actuals, N);
1201 Append_To (Extra_Actuals,
1202 Make_Parameter_Association (Loc,
1203 Explicit_Actual_Parameter => Expr,
1205 Make_Identifier (Loc, Chars (EF))));
1207 Analyze_And_Resolve (Expr, Etype (EF));
1208 end Add_Extra_Actual;
1210 ---------------------------
1211 -- Inherited_From_Formal --
1212 ---------------------------
1214 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1216 Gen_Par : Entity_Id;
1217 Gen_Prim : Elist_Id;
1222 -- If the operation is inherited, it is attached to the corresponding
1223 -- type derivation. If the parent in the derivation is a generic
1224 -- actual, it is a subtype of the actual, and we have to recover the
1225 -- original derived type declaration to find the proper parent.
1227 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1228 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1229 or else Nkind (Type_Definition (Original_Node (Parent (S))))
1230 /= N_Derived_Type_Definition
1231 or else not In_Instance
1238 (Type_Definition (Original_Node (Parent (S)))));
1240 if Nkind (Indic) = N_Subtype_Indication then
1241 Par := Entity (Subtype_Mark (Indic));
1243 Par := Entity (Indic);
1247 if not Is_Generic_Actual_Type (Par)
1248 or else Is_Tagged_Type (Par)
1249 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1250 or else not In_Open_Scopes (Scope (Par))
1255 Gen_Par := Generic_Parent_Type (Parent (Par));
1258 -- If the generic parent type is still the generic type, this
1259 -- is a private formal, not a derived formal, and there are no
1260 -- operations inherited from the formal.
1262 if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
1266 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
1267 Elmt := First_Elmt (Gen_Prim);
1269 while Present (Elmt) loop
1270 if Chars (Node (Elmt)) = Chars (S) then
1276 F1 := First_Formal (S);
1277 F2 := First_Formal (Node (Elmt));
1280 and then Present (F2)
1283 if Etype (F1) = Etype (F2)
1284 or else Etype (F2) = Gen_Par
1290 exit; -- not the right subprogram
1302 raise Program_Error;
1303 end Inherited_From_Formal;
1305 -- Start of processing for Expand_Call
1308 -- Ignore if previous error
1310 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1314 -- Call using access to subprogram with explicit dereference
1316 if Nkind (Name (N)) = N_Explicit_Dereference then
1317 Subp := Etype (Name (N));
1318 Parent_Subp := Empty;
1320 -- Case of call to simple entry, where the Name is a selected component
1321 -- whose prefix is the task, and whose selector name is the entry name
1323 elsif Nkind (Name (N)) = N_Selected_Component then
1324 Subp := Entity (Selector_Name (Name (N)));
1325 Parent_Subp := Empty;
1327 -- Case of call to member of entry family, where Name is an indexed
1328 -- component, with the prefix being a selected component giving the
1329 -- task and entry family name, and the index being the entry index.
1331 elsif Nkind (Name (N)) = N_Indexed_Component then
1332 Subp := Entity (Selector_Name (Prefix (Name (N))));
1333 Parent_Subp := Empty;
1338 Subp := Entity (Name (N));
1339 Parent_Subp := Alias (Subp);
1341 -- Replace call to Raise_Exception by call to Raise_Exception_Always
1342 -- if we can tell that the first parameter cannot possibly be null.
1343 -- This helps optimization and also generation of warnings.
1345 if not Restriction_Active (No_Exception_Handlers)
1346 and then Is_RTE (Subp, RE_Raise_Exception)
1349 FA : constant Node_Id := Original_Node (First_Actual (N));
1352 -- The case we catch is where the first argument is obtained
1353 -- using the Identity attribute (which must always be non-null)
1355 if Nkind (FA) = N_Attribute_Reference
1356 and then Attribute_Name (FA) = Name_Identity
1358 Subp := RTE (RE_Raise_Exception_Always);
1359 Set_Entity (Name (N), Subp);
1364 if Ekind (Subp) = E_Entry then
1365 Parent_Subp := Empty;
1369 -- First step, compute extra actuals, corresponding to any
1370 -- Extra_Formals present. Note that we do not access Extra_Formals
1371 -- directly, instead we simply note the presence of the extra
1372 -- formals as we process the regular formals and collect the
1373 -- corresponding actuals in Extra_Actuals.
1375 -- We also generate any required range checks for actuals as we go
1376 -- through the loop, since this is a convenient place to do this.
1378 Formal := First_Formal (Subp);
1379 Actual := First_Actual (N);
1380 while Present (Formal) loop
1382 -- Generate range check if required (not activated yet ???)
1384 -- if Do_Range_Check (Actual) then
1385 -- Set_Do_Range_Check (Actual, False);
1386 -- Generate_Range_Check
1387 -- (Actual, Etype (Formal), CE_Range_Check_Failed);
1390 -- Prepare to examine current entry
1393 Prev_Orig := Original_Node (Prev);
1395 -- Create possible extra actual for constrained case. Usually,
1396 -- the extra actual is of the form actual'constrained, but since
1397 -- this attribute is only available for unconstrained records,
1398 -- TRUE is expanded if the type of the formal happens to be
1399 -- constrained (for instance when this procedure is inherited
1400 -- from an unconstrained record to a constrained one) or if the
1401 -- actual has no discriminant (its type is constrained). An
1402 -- exception to this is the case of a private type without
1403 -- discriminants. In this case we pass FALSE because the
1404 -- object has underlying discriminants with defaults.
1406 if Present (Extra_Constrained (Formal)) then
1407 if Ekind (Etype (Prev)) in Private_Kind
1408 and then not Has_Discriminants (Base_Type (Etype (Prev)))
1411 New_Occurrence_Of (Standard_False, Loc),
1412 Extra_Constrained (Formal));
1414 elsif Is_Constrained (Etype (Formal))
1415 or else not Has_Discriminants (Etype (Prev))
1418 New_Occurrence_Of (Standard_True, Loc),
1419 Extra_Constrained (Formal));
1421 -- Do not produce extra actuals for Unchecked_Union parameters.
1422 -- Jump directly to the end of the loop.
1424 elsif Is_Unchecked_Union (Base_Type (Etype (Actual))) then
1425 goto Skip_Extra_Actual_Generation;
1428 -- If the actual is a type conversion, then the constrained
1429 -- test applies to the actual, not the target type.
1432 Act_Prev : Node_Id := Prev;
1435 -- Test for unchecked conversions as well, which can
1436 -- occur as out parameter actuals on calls to stream
1439 while Nkind (Act_Prev) = N_Type_Conversion
1440 or else Nkind (Act_Prev) = N_Unchecked_Type_Conversion
1442 Act_Prev := Expression (Act_Prev);
1446 Make_Attribute_Reference (Sloc (Prev),
1448 Duplicate_Subexpr_No_Checks
1449 (Act_Prev, Name_Req => True),
1450 Attribute_Name => Name_Constrained),
1451 Extra_Constrained (Formal));
1456 -- Create possible extra actual for accessibility level
1458 if Present (Extra_Accessibility (Formal)) then
1459 if Is_Entity_Name (Prev_Orig) then
1461 -- When passing an access parameter as the actual to another
1462 -- access parameter we need to pass along the actual's own
1463 -- associated access level parameter. This is done if we are
1464 -- in the scope of the formal access parameter (if this is an
1465 -- inlined body the extra formal is irrelevant).
1467 if Ekind (Entity (Prev_Orig)) in Formal_Kind
1468 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
1469 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
1472 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
1475 pragma Assert (Present (Parm_Ent));
1477 if Present (Extra_Accessibility (Parm_Ent)) then
1480 (Extra_Accessibility (Parm_Ent), Loc),
1481 Extra_Accessibility (Formal));
1483 -- If the actual access parameter does not have an
1484 -- associated extra formal providing its scope level,
1485 -- then treat the actual as having library-level
1490 Make_Integer_Literal (Loc,
1491 Intval => Scope_Depth (Standard_Standard)),
1492 Extra_Accessibility (Formal));
1496 -- The actual is a normal access value, so just pass the
1497 -- level of the actual's access type.
1501 Make_Integer_Literal (Loc,
1502 Intval => Type_Access_Level (Etype (Prev_Orig))),
1503 Extra_Accessibility (Formal));
1507 case Nkind (Prev_Orig) is
1509 when N_Attribute_Reference =>
1511 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
1513 -- For X'Access, pass on the level of the prefix X
1515 when Attribute_Access =>
1517 Make_Integer_Literal (Loc,
1519 Object_Access_Level (Prefix (Prev_Orig))),
1520 Extra_Accessibility (Formal));
1522 -- Treat the unchecked attributes as library-level
1524 when Attribute_Unchecked_Access |
1525 Attribute_Unrestricted_Access =>
1527 Make_Integer_Literal (Loc,
1528 Intval => Scope_Depth (Standard_Standard)),
1529 Extra_Accessibility (Formal));
1531 -- No other cases of attributes returning access
1532 -- values that can be passed to access parameters
1535 raise Program_Error;
1539 -- For allocators we pass the level of the execution of
1540 -- the called subprogram, which is one greater than the
1541 -- current scope level.
1545 Make_Integer_Literal (Loc,
1546 Scope_Depth (Current_Scope) + 1),
1547 Extra_Accessibility (Formal));
1549 -- For other cases we simply pass the level of the
1550 -- actual's access type.
1554 Make_Integer_Literal (Loc,
1555 Intval => Type_Access_Level (Etype (Prev_Orig))),
1556 Extra_Accessibility (Formal));
1562 -- Perform the check of 4.6(49) that prevents a null value
1563 -- from being passed as an actual to an access parameter.
1564 -- Note that the check is elided in the common cases of
1565 -- passing an access attribute or access parameter as an
1566 -- actual. Also, we currently don't enforce this check for
1567 -- expander-generated actuals and when -gnatdj is set.
1569 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
1570 or else Access_Checks_Suppressed (Subp)
1574 elsif Debug_Flag_J then
1577 elsif not Comes_From_Source (Prev) then
1580 elsif Is_Entity_Name (Prev)
1581 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
1585 elsif Nkind (Prev) = N_Allocator
1586 or else Nkind (Prev) = N_Attribute_Reference
1590 -- Suppress null checks when passing to access parameters
1591 -- of Java subprograms. (Should this be done for other
1592 -- foreign conventions as well ???)
1594 elsif Convention (Subp) = Convention_Java then
1597 -- Ada 2005 (AI-231): do not force the check in case of Ada 2005
1598 -- unless it is a null-excluding type
1600 elsif Ada_Version < Ada_05
1601 or else Can_Never_Be_Null (Etype (Prev))
1605 Left_Opnd => Duplicate_Subexpr_No_Checks (Prev),
1606 Right_Opnd => Make_Null (Loc));
1607 Insert_Action (Prev,
1608 Make_Raise_Constraint_Error (Loc,
1610 Reason => CE_Access_Parameter_Is_Null));
1613 -- Perform appropriate validity checks on parameters that
1616 if Validity_Checks_On then
1617 if (Ekind (Formal) = E_In_Parameter
1618 and then Validity_Check_In_Params)
1620 (Ekind (Formal) = E_In_Out_Parameter
1621 and then Validity_Check_In_Out_Params)
1623 -- If the actual is an indexed component of a packed
1624 -- type, it has not been expanded yet. It will be
1625 -- copied in the validity code that follows, and has
1626 -- to be expanded appropriately, so reanalyze it.
1628 if Nkind (Actual) = N_Indexed_Component then
1629 Set_Analyzed (Actual, False);
1632 Ensure_Valid (Actual);
1636 -- For IN OUT and OUT parameters, ensure that subscripts are valid
1637 -- since this is a left side reference. We only do this for calls
1638 -- from the source program since we assume that compiler generated
1639 -- calls explicitly generate any required checks. We also need it
1640 -- only if we are doing standard validity checks, since clearly it
1641 -- is not needed if validity checks are off, and in subscript
1642 -- validity checking mode, all indexed components are checked with
1643 -- a call directly from Expand_N_Indexed_Component.
1645 if Comes_From_Source (N)
1646 and then Ekind (Formal) /= E_In_Parameter
1647 and then Validity_Checks_On
1648 and then Validity_Check_Default
1649 and then not Validity_Check_Subscripts
1651 Check_Valid_Lvalue_Subscripts (Actual);
1654 -- Mark any scalar OUT parameter that is a simple variable
1655 -- as no longer known to be valid (unless the type is always
1656 -- valid). This reflects the fact that if an OUT parameter
1657 -- is never set in a procedure, then it can become invalid
1658 -- on return from the procedure.
1660 if Ekind (Formal) = E_Out_Parameter
1661 and then Is_Entity_Name (Actual)
1662 and then Ekind (Entity (Actual)) = E_Variable
1663 and then not Is_Known_Valid (Etype (Actual))
1665 Set_Is_Known_Valid (Entity (Actual), False);
1668 -- For an OUT or IN OUT parameter of an access type, if the
1669 -- actual is an entity, then it is no longer known to be non-null.
1671 if Ekind (Formal) /= E_In_Parameter
1672 and then Is_Entity_Name (Actual)
1673 and then Is_Access_Type (Etype (Actual))
1675 Set_Is_Known_Non_Null (Entity (Actual), False);
1678 -- If the formal is class wide and the actual is an aggregate, force
1679 -- evaluation so that the back end who does not know about class-wide
1680 -- type, does not generate a temporary of the wrong size.
1682 if not Is_Class_Wide_Type (Etype (Formal)) then
1685 elsif Nkind (Actual) = N_Aggregate
1686 or else (Nkind (Actual) = N_Qualified_Expression
1687 and then Nkind (Expression (Actual)) = N_Aggregate)
1689 Force_Evaluation (Actual);
1692 -- In a remote call, if the formal is of a class-wide type, check
1693 -- that the actual meets the requirements described in E.4(18).
1696 and then Is_Class_Wide_Type (Etype (Formal))
1698 Insert_Action (Actual,
1699 Make_Implicit_If_Statement (N,
1702 Get_Remotely_Callable
1703 (Duplicate_Subexpr_Move_Checks (Actual))),
1704 Then_Statements => New_List (
1705 Make_Raise_Program_Error (Loc,
1706 Reason => PE_Illegal_RACW_E_4_18))));
1709 -- This label is required when skipping extra actual generation for
1710 -- Unchecked_Union parameters.
1712 <<Skip_Extra_Actual_Generation>>
1714 Next_Actual (Actual);
1715 Next_Formal (Formal);
1718 -- If we are expanding a rhs of an assignement we need to check if
1719 -- tag propagation is needed. This code belongs theorically in Analyze
1720 -- Assignment but has to be done earlier (bottom-up) because the
1721 -- assignment might be transformed into a declaration for an uncons-
1722 -- trained value, if the expression is classwide.
1724 if Nkind (N) = N_Function_Call
1725 and then Is_Tag_Indeterminate (N)
1726 and then Is_Entity_Name (Name (N))
1729 Ass : Node_Id := Empty;
1732 if Nkind (Parent (N)) = N_Assignment_Statement then
1735 elsif Nkind (Parent (N)) = N_Qualified_Expression
1736 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
1738 Ass := Parent (Parent (N));
1742 and then Is_Class_Wide_Type (Etype (Name (Ass)))
1744 if Etype (N) /= Root_Type (Etype (Name (Ass))) then
1746 ("tag-indeterminate expression must have type&"
1747 & "('R'M 5.2 (6))", N, Root_Type (Etype (Name (Ass))));
1749 Propagate_Tag (Name (Ass), N);
1752 -- The call will be rewritten as a dispatching call, and
1753 -- expanded as such.
1760 -- Deals with Dispatch_Call if we still have a call, before expanding
1761 -- extra actuals since this will be done on the re-analysis of the
1762 -- dispatching call. Note that we do not try to shorten the actual
1763 -- list for a dispatching call, it would not make sense to do so.
1764 -- Expansion of dispatching calls is suppressed when Java_VM, because
1765 -- the JVM back end directly handles the generation of dispatching
1766 -- calls and would have to undo any expansion to an indirect call.
1768 if (Nkind (N) = N_Function_Call
1769 or else Nkind (N) = N_Procedure_Call_Statement)
1770 and then Present (Controlling_Argument (N))
1771 and then not Java_VM
1773 Expand_Dispatching_Call (N);
1775 -- The following return is worrisome. Is it really OK to
1776 -- skip all remaining processing in this procedure ???
1780 -- Similarly, expand calls to RCI subprograms on which pragma
1781 -- All_Calls_Remote applies. The rewriting will be reanalyzed
1782 -- later. Do this only when the call comes from source since we do
1783 -- not want such a rewritting to occur in expanded code.
1785 elsif Is_All_Remote_Call (N) then
1786 Expand_All_Calls_Remote_Subprogram_Call (N);
1788 -- Similarly, do not add extra actuals for an entry call whose entity
1789 -- is a protected procedure, or for an internal protected subprogram
1790 -- call, because it will be rewritten as a protected subprogram call
1791 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
1793 elsif Is_Protected_Type (Scope (Subp))
1794 and then (Ekind (Subp) = E_Procedure
1795 or else Ekind (Subp) = E_Function)
1799 -- During that loop we gathered the extra actuals (the ones that
1800 -- correspond to Extra_Formals), so now they can be appended.
1803 while Is_Non_Empty_List (Extra_Actuals) loop
1804 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
1808 -- At this point we have all the actuals, so this is the point at
1809 -- which the various expansion activities for actuals is carried out.
1811 Expand_Actuals (N, Subp);
1813 -- If the subprogram is a renaming, or if it is inherited, replace it
1814 -- in the call with the name of the actual subprogram being called.
1815 -- If this is a dispatching call, the run-time decides what to call.
1816 -- The Alias attribute does not apply to entries.
1818 if Nkind (N) /= N_Entry_Call_Statement
1819 and then No (Controlling_Argument (N))
1820 and then Present (Parent_Subp)
1822 if Present (Inherited_From_Formal (Subp)) then
1823 Parent_Subp := Inherited_From_Formal (Subp);
1825 while Present (Alias (Parent_Subp)) loop
1826 Parent_Subp := Alias (Parent_Subp);
1830 Set_Entity (Name (N), Parent_Subp);
1832 if Is_Abstract (Parent_Subp)
1833 and then not In_Instance
1836 ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
1839 -- Add an explicit conversion for parameter of the derived type.
1840 -- This is only done for scalar and access in-parameters. Others
1841 -- have been expanded in expand_actuals.
1843 Formal := First_Formal (Subp);
1844 Parent_Formal := First_Formal (Parent_Subp);
1845 Actual := First_Actual (N);
1847 -- It is not clear that conversion is needed for intrinsic
1848 -- subprograms, but it certainly is for those that are user-
1849 -- defined, and that can be inherited on derivation, namely
1850 -- unchecked conversion and deallocation.
1851 -- General case needs study ???
1853 if not Is_Intrinsic_Subprogram (Parent_Subp)
1854 or else Is_Generic_Instance (Parent_Subp)
1856 while Present (Formal) loop
1858 if Etype (Formal) /= Etype (Parent_Formal)
1859 and then Is_Scalar_Type (Etype (Formal))
1860 and then Ekind (Formal) = E_In_Parameter
1861 and then not Raises_Constraint_Error (Actual)
1864 OK_Convert_To (Etype (Parent_Formal),
1865 Relocate_Node (Actual)));
1868 Resolve (Actual, Etype (Parent_Formal));
1869 Enable_Range_Check (Actual);
1871 elsif Is_Access_Type (Etype (Formal))
1872 and then Base_Type (Etype (Parent_Formal))
1873 /= Base_Type (Etype (Actual))
1875 if Ekind (Formal) /= E_In_Parameter then
1877 Convert_To (Etype (Parent_Formal),
1878 Relocate_Node (Actual)));
1881 Resolve (Actual, Etype (Parent_Formal));
1884 Ekind (Etype (Parent_Formal)) = E_Anonymous_Access_Type
1885 and then Designated_Type (Etype (Parent_Formal))
1887 Designated_Type (Etype (Actual))
1888 and then not Is_Controlling_Formal (Formal)
1890 -- This unchecked conversion is not necessary unless
1891 -- inlining is enabled, because in that case the type
1892 -- mismatch may become visible in the body about to be
1896 Unchecked_Convert_To (Etype (Parent_Formal),
1897 Relocate_Node (Actual)));
1900 Resolve (Actual, Etype (Parent_Formal));
1904 Next_Formal (Formal);
1905 Next_Formal (Parent_Formal);
1906 Next_Actual (Actual);
1911 Subp := Parent_Subp;
1914 -- Check for violation of No_Abort_Statements
1916 if Is_RTE (Subp, RE_Abort_Task) then
1917 Check_Restriction (No_Abort_Statements, N);
1919 -- Check for violation of No_Dynamic_Attachment
1921 elsif RTU_Loaded (Ada_Interrupts)
1922 and then (Is_RTE (Subp, RE_Is_Reserved) or else
1923 Is_RTE (Subp, RE_Is_Attached) or else
1924 Is_RTE (Subp, RE_Current_Handler) or else
1925 Is_RTE (Subp, RE_Attach_Handler) or else
1926 Is_RTE (Subp, RE_Exchange_Handler) or else
1927 Is_RTE (Subp, RE_Detach_Handler) or else
1928 Is_RTE (Subp, RE_Reference))
1930 Check_Restriction (No_Dynamic_Attachment, N);
1933 -- Deal with case where call is an explicit dereference
1935 if Nkind (Name (N)) = N_Explicit_Dereference then
1937 -- Handle case of access to protected subprogram type
1939 if Ekind (Base_Type (Etype (Prefix (Name (N))))) =
1940 E_Access_Protected_Subprogram_Type
1942 -- If this is a call through an access to protected operation,
1943 -- the prefix has the form (object'address, operation'access).
1944 -- Rewrite as a for other protected calls: the object is the
1945 -- first parameter of the list of actuals.
1952 Ptr : constant Node_Id := Prefix (Name (N));
1954 T : constant Entity_Id :=
1955 Equivalent_Type (Base_Type (Etype (Ptr)));
1957 D_T : constant Entity_Id :=
1958 Designated_Type (Base_Type (Etype (Ptr)));
1962 Make_Selected_Component (Loc,
1963 Prefix => Unchecked_Convert_To (T, Ptr),
1965 New_Occurrence_Of (First_Entity (T), Loc));
1968 Make_Selected_Component (Loc,
1969 Prefix => Unchecked_Convert_To (T, Ptr),
1971 New_Occurrence_Of (Next_Entity (First_Entity (T)), Loc));
1973 Nam := Make_Explicit_Dereference (Loc, Nam);
1975 if Present (Parameter_Associations (N)) then
1976 Parm := Parameter_Associations (N);
1981 Prepend (Obj, Parm);
1983 if Etype (D_T) = Standard_Void_Type then
1984 Call := Make_Procedure_Call_Statement (Loc,
1986 Parameter_Associations => Parm);
1988 Call := Make_Function_Call (Loc,
1990 Parameter_Associations => Parm);
1993 Set_First_Named_Actual (Call, First_Named_Actual (N));
1994 Set_Etype (Call, Etype (D_T));
1996 -- We do not re-analyze the call to avoid infinite recursion.
1997 -- We analyze separately the prefix and the object, and set
1998 -- the checks on the prefix that would otherwise be emitted
1999 -- when resolving a call.
2003 Apply_Access_Check (Nam);
2010 -- If this is a call to an intrinsic subprogram, then perform the
2011 -- appropriate expansion to the corresponding tree node and we
2012 -- are all done (since after that the call is gone!)
2014 -- In the case where the intrinsic is to be processed by the back end,
2015 -- the call to Expand_Intrinsic_Call will do nothing, which is fine,
2016 -- since the idea in this case is to pass the call unchanged.
2018 if Is_Intrinsic_Subprogram (Subp) then
2019 Expand_Intrinsic_Call (N, Subp);
2023 if Ekind (Subp) = E_Function
2024 or else Ekind (Subp) = E_Procedure
2026 if Is_Inlined (Subp) then
2028 Inlined_Subprogram : declare
2030 Must_Inline : Boolean := False;
2031 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
2032 Scop : constant Entity_Id := Scope (Subp);
2034 function In_Unfrozen_Instance return Boolean;
2035 -- If the subprogram comes from an instance in the same
2036 -- unit, and the instance is not yet frozen, inlining might
2037 -- trigger order-of-elaboration problems in gigi.
2039 --------------------------
2040 -- In_Unfrozen_Instance --
2041 --------------------------
2043 function In_Unfrozen_Instance return Boolean is
2044 S : Entity_Id := Scop;
2048 and then S /= Standard_Standard
2050 if Is_Generic_Instance (S)
2051 and then Present (Freeze_Node (S))
2052 and then not Analyzed (Freeze_Node (S))
2061 end In_Unfrozen_Instance;
2063 -- Start of processing for Inlined_Subprogram
2066 -- Verify that the body to inline has already been seen,
2067 -- and that if the body is in the current unit the inlining
2068 -- does not occur earlier. This avoids order-of-elaboration
2069 -- problems in gigi.
2072 or else Nkind (Spec) /= N_Subprogram_Declaration
2073 or else No (Body_To_Inline (Spec))
2075 Must_Inline := False;
2077 -- If this an inherited function that returns a private
2078 -- type, do not inline if the full view is an unconstrained
2079 -- array, because such calls cannot be inlined.
2081 elsif Present (Orig_Subp)
2082 and then Is_Array_Type (Etype (Orig_Subp))
2083 and then not Is_Constrained (Etype (Orig_Subp))
2085 Must_Inline := False;
2087 elsif In_Unfrozen_Instance then
2088 Must_Inline := False;
2091 Bod := Body_To_Inline (Spec);
2093 if (In_Extended_Main_Code_Unit (N)
2094 or else In_Extended_Main_Code_Unit (Parent (N))
2095 or else Is_Always_Inlined (Subp))
2096 and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
2098 Earlier_In_Extended_Unit (Sloc (Bod), Loc))
2100 Must_Inline := True;
2102 -- If we are compiling a package body that is not the main
2103 -- unit, it must be for inlining/instantiation purposes,
2104 -- in which case we inline the call to insure that the same
2105 -- temporaries are generated when compiling the body by
2106 -- itself. Otherwise link errors can occur.
2108 -- If the function being called is itself in the main unit,
2109 -- we cannot inline, because there is a risk of double
2110 -- elaboration and/or circularity: the inlining can make
2111 -- visible a private entity in the body of the main unit,
2112 -- that gigi will see before its sees its proper definition.
2114 elsif not (In_Extended_Main_Code_Unit (N))
2115 and then In_Package_Body
2117 Must_Inline := not In_Extended_Main_Source_Unit (Subp);
2122 Expand_Inlined_Call (N, Subp, Orig_Subp);
2125 -- Let the back end handle it
2127 Add_Inlined_Body (Subp);
2129 if Front_End_Inlining
2130 and then Nkind (Spec) = N_Subprogram_Declaration
2131 and then (In_Extended_Main_Code_Unit (N))
2132 and then No (Body_To_Inline (Spec))
2133 and then not Has_Completion (Subp)
2134 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
2137 ("cannot inline& (body not seen yet)?",
2141 end Inlined_Subprogram;
2145 -- Check for a protected subprogram. This is either an intra-object
2146 -- call, or a protected function call. Protected procedure calls are
2147 -- rewritten as entry calls and handled accordingly.
2149 Scop := Scope (Subp);
2151 if Nkind (N) /= N_Entry_Call_Statement
2152 and then Is_Protected_Type (Scop)
2154 -- If the call is an internal one, it is rewritten as a call to
2155 -- to the corresponding unprotected subprogram.
2157 Expand_Protected_Subprogram_Call (N, Subp, Scop);
2160 -- Functions returning controlled objects need special attention
2162 if Controlled_Type (Etype (Subp))
2163 and then not Is_Return_By_Reference_Type (Etype (Subp))
2165 Expand_Ctrl_Function_Call (N);
2168 -- Test for First_Optional_Parameter, and if so, truncate parameter
2169 -- list if there are optional parameters at the trailing end.
2170 -- Note we never delete procedures for call via a pointer.
2172 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
2173 and then Present (First_Optional_Parameter (Subp))
2176 Last_Keep_Arg : Node_Id;
2179 -- Last_Keep_Arg will hold the last actual that should be
2180 -- retained. If it remains empty at the end, it means that
2181 -- all parameters are optional.
2183 Last_Keep_Arg := Empty;
2185 -- Find first optional parameter, must be present since we
2186 -- checked the validity of the parameter before setting it.
2188 Formal := First_Formal (Subp);
2189 Actual := First_Actual (N);
2190 while Formal /= First_Optional_Parameter (Subp) loop
2191 Last_Keep_Arg := Actual;
2192 Next_Formal (Formal);
2193 Next_Actual (Actual);
2196 -- We have Formal and Actual pointing to the first potentially
2197 -- droppable argument. We can drop all the trailing arguments
2198 -- whose actual matches the default. Note that we know that all
2199 -- remaining formals have defaults, because we checked that this
2200 -- requirement was met before setting First_Optional_Parameter.
2202 -- We use Fully_Conformant_Expressions to check for identity
2203 -- between formals and actuals, which may miss some cases, but
2204 -- on the other hand, this is only an optimization (if we fail
2205 -- to truncate a parameter it does not affect functionality).
2206 -- So if the default is 3 and the actual is 1+2, we consider
2207 -- them unequal, which hardly seems worrisome.
2209 while Present (Formal) loop
2210 if not Fully_Conformant_Expressions
2211 (Actual, Default_Value (Formal))
2213 Last_Keep_Arg := Actual;
2216 Next_Formal (Formal);
2217 Next_Actual (Actual);
2220 -- If no arguments, delete entire list, this is the easy case
2222 if No (Last_Keep_Arg) then
2223 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2224 Delete_Tree (Remove_Head (Parameter_Associations (N)));
2227 Set_Parameter_Associations (N, No_List);
2228 Set_First_Named_Actual (N, Empty);
2230 -- Case where at the last retained argument is positional. This
2231 -- is also an easy case, since the retained arguments are already
2232 -- in the right form, and we don't need to worry about the order
2233 -- of arguments that get eliminated.
2235 elsif Is_List_Member (Last_Keep_Arg) then
2236 while Present (Next (Last_Keep_Arg)) loop
2237 Delete_Tree (Remove_Next (Last_Keep_Arg));
2240 Set_First_Named_Actual (N, Empty);
2242 -- This is the annoying case where the last retained argument
2243 -- is a named parameter. Since the original arguments are not
2244 -- in declaration order, we may have to delete some fairly
2245 -- random collection of arguments.
2253 pragma Warnings (Off, Discard);
2256 -- First step, remove all the named parameters from the
2257 -- list (they are still chained using First_Named_Actual
2258 -- and Next_Named_Actual, so we have not lost them!)
2260 Temp := First (Parameter_Associations (N));
2262 -- Case of all parameters named, remove them all
2264 if Nkind (Temp) = N_Parameter_Association then
2265 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2266 Temp := Remove_Head (Parameter_Associations (N));
2269 -- Case of mixed positional/named, remove named parameters
2272 while Nkind (Next (Temp)) /= N_Parameter_Association loop
2276 while Present (Next (Temp)) loop
2277 Discard := Remove_Next (Temp);
2281 -- Now we loop through the named parameters, till we get
2282 -- to the last one to be retained, adding them to the list.
2283 -- Note that the Next_Named_Actual list does not need to be
2284 -- touched since we are only reordering them on the actual
2285 -- parameter association list.
2287 Passoc := Parent (First_Named_Actual (N));
2289 Temp := Relocate_Node (Passoc);
2291 (Parameter_Associations (N), Temp);
2293 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
2294 Passoc := Parent (Next_Named_Actual (Passoc));
2297 Set_Next_Named_Actual (Temp, Empty);
2300 Temp := Next_Named_Actual (Passoc);
2301 exit when No (Temp);
2302 Set_Next_Named_Actual
2303 (Passoc, Next_Named_Actual (Parent (Temp)));
2312 --------------------------
2313 -- Expand_Inlined_Call --
2314 --------------------------
2316 procedure Expand_Inlined_Call
2319 Orig_Subp : Entity_Id)
2321 Loc : constant Source_Ptr := Sloc (N);
2322 Is_Predef : constant Boolean :=
2323 Is_Predefined_File_Name
2324 (Unit_File_Name (Get_Source_Unit (Subp)));
2325 Orig_Bod : constant Node_Id :=
2326 Body_To_Inline (Unit_Declaration_Node (Subp));
2331 Exit_Lab : Entity_Id := Empty;
2338 Ret_Type : Entity_Id;
2341 Temp_Typ : Entity_Id;
2343 procedure Make_Exit_Label;
2344 -- Build declaration for exit label to be used in Return statements
2346 function Process_Formals (N : Node_Id) return Traverse_Result;
2347 -- Replace occurrence of a formal with the corresponding actual, or
2348 -- the thunk generated for it.
2350 function Process_Sloc (Nod : Node_Id) return Traverse_Result;
2351 -- If the call being expanded is that of an internal subprogram,
2352 -- set the sloc of the generated block to that of the call itself,
2353 -- so that the expansion is skipped by the -next- command in gdb.
2354 -- Same processing for a subprogram in a predefined file, e.g.
2355 -- Ada.Tags. If Debug_Generated_Code is true, suppress this change
2356 -- to simplify our own development.
2358 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
2359 -- If the function body is a single expression, replace call with
2360 -- expression, else insert block appropriately.
2362 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
2363 -- If procedure body has no local variables, inline body without
2364 -- creating block, otherwise rewrite call with block.
2366 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean;
2367 -- Determine whether a formal parameter is used only once in Orig_Bod
2369 ---------------------
2370 -- Make_Exit_Label --
2371 ---------------------
2373 procedure Make_Exit_Label is
2375 -- Create exit label for subprogram if one does not exist yet
2377 if No (Exit_Lab) then
2378 Lab_Id := Make_Identifier (Loc, New_Internal_Name ('L'));
2380 Make_Defining_Identifier (Loc, Chars (Lab_Id)));
2381 Exit_Lab := Make_Label (Loc, Lab_Id);
2384 Make_Implicit_Label_Declaration (Loc,
2385 Defining_Identifier => Entity (Lab_Id),
2386 Label_Construct => Exit_Lab);
2388 end Make_Exit_Label;
2390 ---------------------
2391 -- Process_Formals --
2392 ---------------------
2394 function Process_Formals (N : Node_Id) return Traverse_Result is
2400 if Is_Entity_Name (N)
2401 and then Present (Entity (N))
2406 and then Scope (E) = Subp
2408 A := Renamed_Object (E);
2410 if Is_Entity_Name (A) then
2411 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
2413 elsif Nkind (A) = N_Defining_Identifier then
2414 Rewrite (N, New_Occurrence_Of (A, Loc));
2416 else -- numeric literal
2417 Rewrite (N, New_Copy (A));
2423 elsif Nkind (N) = N_Return_Statement then
2425 if No (Expression (N)) then
2427 Rewrite (N, Make_Goto_Statement (Loc,
2428 Name => New_Copy (Lab_Id)));
2431 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
2432 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
2434 -- Function body is a single expression. No need for
2440 Num_Ret := Num_Ret + 1;
2444 -- Because of the presence of private types, the views of the
2445 -- expression and the context may be different, so place an
2446 -- unchecked conversion to the context type to avoid spurious
2447 -- errors, eg. when the expression is a numeric literal and
2448 -- the context is private. If the expression is an aggregate,
2449 -- use a qualified expression, because an aggregate is not a
2450 -- legal argument of a conversion.
2452 if Nkind (Expression (N)) = N_Aggregate
2453 or else Nkind (Expression (N)) = N_Null
2456 Make_Qualified_Expression (Sloc (N),
2457 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
2458 Expression => Relocate_Node (Expression (N)));
2461 Unchecked_Convert_To
2462 (Ret_Type, Relocate_Node (Expression (N)));
2465 if Nkind (Targ) = N_Defining_Identifier then
2467 Make_Assignment_Statement (Loc,
2468 Name => New_Occurrence_Of (Targ, Loc),
2469 Expression => Ret));
2472 Make_Assignment_Statement (Loc,
2473 Name => New_Copy (Targ),
2474 Expression => Ret));
2477 Set_Assignment_OK (Name (N));
2479 if Present (Exit_Lab) then
2481 Make_Goto_Statement (Loc,
2482 Name => New_Copy (Lab_Id)));
2488 -- Remove pragma Unreferenced since it may refer to formals that
2489 -- are not visible in the inlined body, and in any case we will
2490 -- not be posting warnings on the inlined body so it is unneeded.
2492 elsif Nkind (N) = N_Pragma
2493 and then Chars (N) = Name_Unreferenced
2495 Rewrite (N, Make_Null_Statement (Sloc (N)));
2501 end Process_Formals;
2503 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
2509 function Process_Sloc (Nod : Node_Id) return Traverse_Result is
2511 if not Debug_Generated_Code then
2512 Set_Sloc (Nod, Sloc (N));
2513 Set_Comes_From_Source (Nod, False);
2519 procedure Reset_Slocs is new Traverse_Proc (Process_Sloc);
2521 ---------------------------
2522 -- Rewrite_Function_Call --
2523 ---------------------------
2525 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
2526 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
2527 Fst : constant Node_Id := First (Statements (HSS));
2530 -- Optimize simple case: function body is a single return statement,
2531 -- which has been expanded into an assignment.
2533 if Is_Empty_List (Declarations (Blk))
2534 and then Nkind (Fst) = N_Assignment_Statement
2535 and then No (Next (Fst))
2538 -- The function call may have been rewritten as the temporary
2539 -- that holds the result of the call, in which case remove the
2540 -- now useless declaration.
2542 if Nkind (N) = N_Identifier
2543 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2545 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
2548 Rewrite (N, Expression (Fst));
2550 elsif Nkind (N) = N_Identifier
2551 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2553 -- The block assigns the result of the call to the temporary
2555 Insert_After (Parent (Entity (N)), Blk);
2557 elsif Nkind (Parent (N)) = N_Assignment_Statement
2558 and then Is_Entity_Name (Name (Parent (N)))
2560 -- Replace assignment with the block
2563 Original_Assignment : constant Node_Id := Parent (N);
2566 -- Preserve the original assignment node to keep the
2567 -- complete assignment subtree consistent enough for
2568 -- Analyze_Assignment to proceed (specifically, the
2569 -- original Lhs node must still have an assignment
2570 -- statement as its parent).
2572 -- We cannot rely on Original_Node to go back from the
2573 -- block node to the assignment node, because the
2574 -- assignment might already be a rewrite substitution.
2576 Discard_Node (Relocate_Node (Original_Assignment));
2577 Rewrite (Original_Assignment, Blk);
2580 elsif Nkind (Parent (N)) = N_Object_Declaration then
2581 Set_Expression (Parent (N), Empty);
2582 Insert_After (Parent (N), Blk);
2584 end Rewrite_Function_Call;
2586 ----------------------------
2587 -- Rewrite_Procedure_Call --
2588 ----------------------------
2590 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
2591 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
2593 if Is_Empty_List (Declarations (Blk)) then
2594 Insert_List_After (N, Statements (HSS));
2595 Rewrite (N, Make_Null_Statement (Loc));
2599 end Rewrite_Procedure_Call;
2601 -------------------------
2602 -- Formal_Is_Used_Once --
2603 ------------------------
2605 function Formal_Is_Used_Once (Formal : Entity_Id) return Boolean is
2606 Use_Counter : Int := 0;
2608 function Count_Uses (N : Node_Id) return Traverse_Result;
2609 -- Traverse the tree and count the uses of the formal parameter.
2610 -- In this case, for optimization purposes, we do not need to
2611 -- continue the traversal once more than one use is encountered.
2617 function Count_Uses (N : Node_Id) return Traverse_Result is
2619 -- The original node is an identifier
2621 if Nkind (N) = N_Identifier
2622 and then Present (Entity (N))
2624 -- The original node's entity points to the one in the
2627 and then Nkind (Entity (N)) = N_Identifier
2628 and then Present (Entity (Entity (N)))
2630 -- The entity of the copied node is the formal parameter
2632 and then Entity (Entity (N)) = Formal
2634 Use_Counter := Use_Counter + 1;
2636 if Use_Counter > 1 then
2638 -- Denote more than one use and abandon the traversal
2649 procedure Count_Formal_Uses is new Traverse_Proc (Count_Uses);
2651 -- Start of processing for Formal_Is_Used_Once
2654 Count_Formal_Uses (Orig_Bod);
2655 return Use_Counter = 1;
2656 end Formal_Is_Used_Once;
2658 -- Start of processing for Expand_Inlined_Call
2661 -- Check for special case of To_Address call, and if so, just do an
2662 -- unchecked conversion instead of expanding the call. Not only is this
2663 -- more efficient, but it also avoids problem with order of elaboration
2664 -- when address clauses are inlined (address expr elaborated at wrong
2667 if Subp = RTE (RE_To_Address) then
2669 Unchecked_Convert_To
2671 Relocate_Node (First_Actual (N))));
2675 -- Check for an illegal attempt to inline a recursive procedure. If the
2676 -- subprogram has parameters this is detected when trying to supply a
2677 -- binding for parameters that already have one. For parameterless
2678 -- subprograms this must be done explicitly.
2680 if In_Open_Scopes (Subp) then
2681 Error_Msg_N ("call to recursive subprogram cannot be inlined?", N);
2682 Set_Is_Inlined (Subp, False);
2686 if Nkind (Orig_Bod) = N_Defining_Identifier then
2688 -- Subprogram is a renaming_as_body. Calls appearing after the
2689 -- renaming can be replaced with calls to the renamed entity
2690 -- directly, because the subprograms are subtype conformant. If
2691 -- the renamed subprogram is an inherited operation, we must redo
2692 -- the expansion because implicit conversions may be needed.
2694 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
2696 if Present (Alias (Orig_Bod)) then
2703 -- Use generic machinery to copy body of inlined subprogram, as if it
2704 -- were an instantiation, resetting source locations appropriately, so
2705 -- that nested inlined calls appear in the main unit.
2707 Save_Env (Subp, Empty);
2708 Set_Copied_Sloc_For_Inlined_Body (N, Defining_Entity (Orig_Bod));
2710 Bod := Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
2712 Make_Block_Statement (Loc,
2713 Declarations => Declarations (Bod),
2714 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
2716 if No (Declarations (Bod)) then
2717 Set_Declarations (Blk, New_List);
2720 -- If this is a derived function, establish the proper return type
2722 if Present (Orig_Subp)
2723 and then Orig_Subp /= Subp
2725 Ret_Type := Etype (Orig_Subp);
2727 Ret_Type := Etype (Subp);
2730 F := First_Formal (Subp);
2731 A := First_Actual (N);
2733 -- Create temporaries for the actuals that are expressions, or that
2734 -- are scalars and require copying to preserve semantics.
2736 while Present (F) loop
2737 if Present (Renamed_Object (F)) then
2738 Error_Msg_N (" cannot inline call to recursive subprogram", N);
2742 -- If the argument may be a controlling argument in a call within
2743 -- the inlined body, we must preserve its classwide nature to insure
2744 -- that dynamic dispatching take place subsequently. If the formal
2745 -- has a constraint it must be preserved to retain the semantics of
2748 if Is_Class_Wide_Type (Etype (F))
2749 or else (Is_Access_Type (Etype (F))
2751 Is_Class_Wide_Type (Designated_Type (Etype (F))))
2753 Temp_Typ := Etype (F);
2755 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
2756 and then Etype (F) /= Base_Type (Etype (F))
2758 Temp_Typ := Etype (F);
2761 Temp_Typ := Etype (A);
2764 -- If the actual is a simple name or a literal, no need to
2765 -- create a temporary, object can be used directly.
2767 if (Is_Entity_Name (A)
2769 (not Is_Scalar_Type (Etype (A))
2770 or else Ekind (Entity (A)) = E_Enumeration_Literal))
2772 -- When the actual is an identifier and the corresponding formal
2773 -- is used only once in the original body, the formal can be
2774 -- substituted directly with the actual parameter.
2776 or else (Nkind (A) = N_Identifier
2777 and then Formal_Is_Used_Once (F))
2779 or else Nkind (A) = N_Real_Literal
2780 or else Nkind (A) = N_Integer_Literal
2781 or else Nkind (A) = N_Character_Literal
2783 if Etype (F) /= Etype (A) then
2785 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
2787 Set_Renamed_Object (F, A);
2792 Make_Defining_Identifier (Loc,
2793 Chars => New_Internal_Name ('C'));
2795 -- If the actual for an in/in-out parameter is a view conversion,
2796 -- make it into an unchecked conversion, given that an untagged
2797 -- type conversion is not a proper object for a renaming.
2799 -- In-out conversions that involve real conversions have already
2800 -- been transformed in Expand_Actuals.
2802 if Nkind (A) = N_Type_Conversion
2803 and then Ekind (F) /= E_In_Parameter
2805 New_A := Make_Unchecked_Type_Conversion (Loc,
2806 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
2807 Expression => Relocate_Node (Expression (A)));
2809 elsif Etype (F) /= Etype (A) then
2810 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
2811 Temp_Typ := Etype (F);
2814 New_A := Relocate_Node (A);
2817 Set_Sloc (New_A, Sloc (N));
2819 if Ekind (F) = E_In_Parameter
2820 and then not Is_Limited_Type (Etype (A))
2823 Make_Object_Declaration (Loc,
2824 Defining_Identifier => Temp,
2825 Constant_Present => True,
2826 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
2827 Expression => New_A);
2830 Make_Object_Renaming_Declaration (Loc,
2831 Defining_Identifier => Temp,
2832 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
2836 Prepend (Decl, Declarations (Blk));
2837 Set_Renamed_Object (F, Temp);
2844 -- Establish target of function call. If context is not assignment or
2845 -- declaration, create a temporary as a target. The declaration for
2846 -- the temporary may be subsequently optimized away if the body is a
2847 -- single expression, or if the left-hand side of the assignment is
2850 if Ekind (Subp) = E_Function then
2851 if Nkind (Parent (N)) = N_Assignment_Statement
2852 and then Is_Entity_Name (Name (Parent (N)))
2854 Targ := Name (Parent (N));
2857 -- Replace call with temporary and create its declaration
2860 Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
2863 Make_Object_Declaration (Loc,
2864 Defining_Identifier => Temp,
2865 Object_Definition =>
2866 New_Occurrence_Of (Ret_Type, Loc));
2868 Set_No_Initialization (Decl);
2869 Insert_Action (N, Decl);
2870 Rewrite (N, New_Occurrence_Of (Temp, Loc));
2875 -- Traverse the tree and replace formals with actuals or their thunks.
2876 -- Attach block to tree before analysis and rewriting.
2878 Replace_Formals (Blk);
2879 Set_Parent (Blk, N);
2881 if not Comes_From_Source (Subp)
2887 if Present (Exit_Lab) then
2889 -- If the body was a single expression, the single return statement
2890 -- and the corresponding label are useless.
2894 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
2897 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
2899 Append (Lab_Decl, (Declarations (Blk)));
2900 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
2904 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
2905 -- conflicting private views that Gigi would ignore. If this is
2906 -- predefined unit, analyze with checks off, as is done in the non-
2907 -- inlined run-time units.
2910 I_Flag : constant Boolean := In_Inlined_Body;
2913 In_Inlined_Body := True;
2917 Style : constant Boolean := Style_Check;
2919 Style_Check := False;
2920 Analyze (Blk, Suppress => All_Checks);
2921 Style_Check := Style;
2928 In_Inlined_Body := I_Flag;
2931 if Ekind (Subp) = E_Procedure then
2932 Rewrite_Procedure_Call (N, Blk);
2934 Rewrite_Function_Call (N, Blk);
2939 -- Cleanup mapping between formals and actuals for other expansions
2941 F := First_Formal (Subp);
2943 while Present (F) loop
2944 Set_Renamed_Object (F, Empty);
2947 end Expand_Inlined_Call;
2949 ----------------------------
2950 -- Expand_N_Function_Call --
2951 ----------------------------
2953 procedure Expand_N_Function_Call (N : Node_Id) is
2954 Typ : constant Entity_Id := Etype (N);
2956 function Returned_By_Reference return Boolean;
2957 -- If the return type is returned through the secondary stack. that is
2958 -- by reference, we don't want to create a temp to force stack checking.
2959 -- Shouldn't this function be moved to exp_util???
2961 function Rhs_Of_Assign_Or_Decl (N : Node_Id) return Boolean;
2962 -- If the call is the right side of an assignment or the expression in
2963 -- an object declaration, we don't need to create a temp as the left
2964 -- side will already trigger stack checking if necessary.
2966 ---------------------------
2967 -- Returned_By_Reference --
2968 ---------------------------
2970 function Returned_By_Reference return Boolean is
2971 S : Entity_Id := Current_Scope;
2974 if Is_Return_By_Reference_Type (Typ) then
2977 elsif Nkind (Parent (N)) /= N_Return_Statement then
2980 elsif Requires_Transient_Scope (Typ) then
2982 -- Verify that the return type of the enclosing function has the
2983 -- same constrained status as that of the expression.
2985 while Ekind (S) /= E_Function loop
2989 return Is_Constrained (Typ) = Is_Constrained (Etype (S));
2993 end Returned_By_Reference;
2995 ---------------------------
2996 -- Rhs_Of_Assign_Or_Decl --
2997 ---------------------------
2999 function Rhs_Of_Assign_Or_Decl (N : Node_Id) return Boolean is
3001 if (Nkind (Parent (N)) = N_Assignment_Statement
3002 and then Expression (Parent (N)) = N)
3004 (Nkind (Parent (N)) = N_Qualified_Expression
3005 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
3006 and then Expression (Parent (Parent (N))) = Parent (N))
3008 (Nkind (Parent (N)) = N_Object_Declaration
3009 and then Expression (Parent (N)) = N)
3011 (Nkind (Parent (N)) = N_Component_Association
3012 and then Expression (Parent (N)) = N
3013 and then Nkind (Parent (Parent (N))) = N_Aggregate
3014 and then Rhs_Of_Assign_Or_Decl (Parent (Parent (N))))
3020 end Rhs_Of_Assign_Or_Decl;
3022 -- Start of processing for Expand_N_Function_Call
3025 -- A special check. If stack checking is enabled, and the return type
3026 -- might generate a large temporary, and the call is not the right side
3027 -- of an assignment, then generate an explicit temporary. We do this
3028 -- because otherwise gigi may generate a large temporary on the fly and
3029 -- this can cause trouble with stack checking.
3031 -- This is unecessary if the call is the expression in an object
3032 -- declaration, or if it appears outside of any library unit. This can
3033 -- only happen if it appears as an actual in a library-level instance,
3034 -- in which case a temporary will be generated for it once the instance
3035 -- itself is installed.
3037 if May_Generate_Large_Temp (Typ)
3038 and then not Rhs_Of_Assign_Or_Decl (N)
3039 and then not Returned_By_Reference
3040 and then Current_Scope /= Standard_Standard
3042 if Stack_Checking_Enabled then
3044 -- Note: it might be thought that it would be OK to use a call to
3045 -- Force_Evaluation here, but that's not good enough, because
3046 -- that can results in a 'Reference construct that may still need
3050 Loc : constant Source_Ptr := Sloc (N);
3051 Temp_Obj : constant Entity_Id :=
3052 Make_Defining_Identifier (Loc,
3053 Chars => New_Internal_Name ('F'));
3054 Temp_Typ : Entity_Id := Typ;
3061 if Is_Tagged_Type (Typ)
3062 and then Present (Controlling_Argument (N))
3064 if Nkind (Parent (N)) /= N_Procedure_Call_Statement
3065 and then Nkind (Parent (N)) /= N_Function_Call
3067 -- If this is a tag-indeterminate call, the object must
3070 if Is_Tag_Indeterminate (N) then
3071 Temp_Typ := Class_Wide_Type (Typ);
3075 -- If this is a dispatching call that is itself the
3076 -- controlling argument of an enclosing call, the
3077 -- nominal subtype of the object that replaces it must
3078 -- be classwide, so that dispatching will take place
3079 -- properly. If it is not a controlling argument, the
3080 -- object is not classwide.
3082 Proc := Entity (Name (Parent (N)));
3083 F := First_Formal (Proc);
3084 A := First_Actual (Parent (N));
3091 if Is_Controlling_Formal (F) then
3092 Temp_Typ := Class_Wide_Type (Typ);
3098 Make_Object_Declaration (Loc,
3099 Defining_Identifier => Temp_Obj,
3100 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
3101 Constant_Present => True,
3102 Expression => Relocate_Node (N));
3103 Set_Assignment_OK (Decl);
3105 Insert_Actions (N, New_List (Decl));
3106 Rewrite (N, New_Occurrence_Of (Temp_Obj, Loc));
3110 -- If stack-checking is not enabled, increment serial number
3111 -- for internal names, so that subsequent symbols are consistent
3112 -- with and without stack-checking.
3114 Synchronize_Serial_Number;
3116 -- Now we can expand the call with consistent symbol names
3121 -- Normal case, expand the call
3126 end Expand_N_Function_Call;
3128 ---------------------------------------
3129 -- Expand_N_Procedure_Call_Statement --
3130 ---------------------------------------
3132 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
3135 end Expand_N_Procedure_Call_Statement;
3137 ------------------------------
3138 -- Expand_N_Subprogram_Body --
3139 ------------------------------
3141 -- Add poll call if ATC polling is enabled, unless the body will be
3142 -- inlined by the back-end.
3144 -- Add return statement if last statement in body is not a return statement
3145 -- (this makes things easier on Gigi which does not want to have to handle
3146 -- a missing return).
3148 -- Add call to Activate_Tasks if body is a task activator
3150 -- Deal with possible detection of infinite recursion
3152 -- Eliminate body completely if convention stubbed
3154 -- Encode entity names within body, since we will not need to reference
3155 -- these entities any longer in the front end.
3157 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
3159 -- Reset Pure indication if any parameter has root type System.Address
3163 procedure Expand_N_Subprogram_Body (N : Node_Id) is
3164 Loc : constant Source_Ptr := Sloc (N);
3165 H : constant Node_Id := Handled_Statement_Sequence (N);
3166 Body_Id : Entity_Id;
3167 Spec_Id : Entity_Id;
3174 procedure Add_Return (S : List_Id);
3175 -- Append a return statement to the statement sequence S if the last
3176 -- statement is not already a return or a goto statement. Note that
3177 -- the latter test is not critical, it does not matter if we add a
3178 -- few extra returns, since they get eliminated anyway later on.
3180 procedure Expand_Thread_Body;
3181 -- Perform required expansion of a thread body
3187 procedure Add_Return (S : List_Id) is
3189 if not Is_Transfer (Last (S)) then
3191 -- The source location for the return is the end label
3192 -- of the procedure in all cases. This is a bit odd when
3193 -- there are exception handlers, but not much else we can do.
3195 Append_To (S, Make_Return_Statement (Sloc (End_Label (H))));
3199 ------------------------
3200 -- Expand_Thread_Body --
3201 ------------------------
3203 -- The required expansion of a thread body is as follows
3205 -- procedure <thread body procedure name> is
3207 -- _Secondary_Stack : aliased
3208 -- Storage_Elements.Storage_Array
3209 -- (1 .. Storage_Offset (Sec_Stack_Size));
3210 -- for _Secondary_Stack'Alignment use Standard'Maximum_Alignment;
3212 -- _Process_ATSD : aliased System.Threads.ATSD;
3215 -- System.Threads.Thread_Body_Enter;
3216 -- (_Secondary_Stack'Address,
3217 -- _Secondary_Stack'Length,
3218 -- _Process_ATSD'Address);
3221 -- <user declarations>
3223 -- <user statements>
3224 -- <user exception handlers>
3227 -- System.Threads.Thread_Body_Leave;
3230 -- when E : others =>
3231 -- System.Threads.Thread_Body_Exceptional_Exit (E);
3234 -- Note the exception handler is omitted if pragma Restriction
3235 -- No_Exception_Handlers is currently active.
3237 procedure Expand_Thread_Body is
3238 User_Decls : constant List_Id := Declarations (N);
3239 Sec_Stack_Len : Node_Id;
3241 TB_Pragma : constant Node_Id :=
3242 Get_Rep_Pragma (Spec_Id, Name_Thread_Body);
3245 Ent_ATSD : Entity_Id;
3249 Decl_ATSD : Node_Id;
3251 Excep_Handlers : List_Id;
3254 New_Scope (Spec_Id);
3256 -- Get proper setting for secondary stack size
3258 if List_Length (Pragma_Argument_Associations (TB_Pragma)) = 2 then
3260 Expression (Last (Pragma_Argument_Associations (TB_Pragma)));
3263 New_Occurrence_Of (RTE (RE_Default_Secondary_Stack_Size), Loc);
3266 Sec_Stack_Len := Convert_To (RTE (RE_Storage_Offset), Sec_Stack_Len);
3268 -- Build and set declarations for the wrapped thread body
3270 Ent_SS := Make_Defining_Identifier (Loc, Name_uSecondary_Stack);
3271 Ent_ATSD := Make_Defining_Identifier (Loc, Name_uProcess_ATSD);
3274 Make_Object_Declaration (Loc,
3275 Defining_Identifier => Ent_SS,
3276 Aliased_Present => True,
3277 Object_Definition =>
3278 Make_Subtype_Indication (Loc,
3280 New_Occurrence_Of (RTE (RE_Storage_Array), Loc),
3282 Make_Index_Or_Discriminant_Constraint (Loc,
3283 Constraints => New_List (
3285 Low_Bound => Make_Integer_Literal (Loc, 1),
3286 High_Bound => Sec_Stack_Len)))));
3289 Make_Object_Declaration (Loc,
3290 Defining_Identifier => Ent_ATSD,
3291 Aliased_Present => True,
3292 Object_Definition => New_Occurrence_Of (RTE (RE_ATSD), Loc));
3294 Set_Declarations (N, New_List (Decl_SS, Decl_ATSD));
3296 Analyze (Decl_ATSD);
3297 Set_Alignment (Ent_SS, UI_From_Int (Maximum_Alignment));
3299 -- Create new exception handler
3301 if Restriction_Active (No_Exception_Handlers) then
3302 Excep_Handlers := No_List;
3305 Check_Restriction (No_Exception_Handlers, N);
3307 Ent_EO := Make_Defining_Identifier (Loc, Name_uE);
3309 Excep_Handlers := New_List (
3310 Make_Exception_Handler (Loc,
3311 Choice_Parameter => Ent_EO,
3312 Exception_Choices => New_List (
3313 Make_Others_Choice (Loc)),
3314 Statements => New_List (
3315 Make_Procedure_Call_Statement (Loc,
3318 (RTE (RE_Thread_Body_Exceptional_Exit), Loc),
3319 Parameter_Associations => New_List (
3320 New_Occurrence_Of (Ent_EO, Loc))))));
3323 -- Now build new handled statement sequence and analyze it
3325 Set_Handled_Statement_Sequence (N,
3326 Make_Handled_Sequence_Of_Statements (Loc,
3327 Statements => New_List (
3329 Make_Procedure_Call_Statement (Loc,
3330 Name => New_Occurrence_Of (RTE (RE_Thread_Body_Enter), Loc),
3331 Parameter_Associations => New_List (
3333 Make_Attribute_Reference (Loc,
3334 Prefix => New_Occurrence_Of (Ent_SS, Loc),
3335 Attribute_Name => Name_Address),
3337 Make_Attribute_Reference (Loc,
3338 Prefix => New_Occurrence_Of (Ent_SS, Loc),
3339 Attribute_Name => Name_Length),
3341 Make_Attribute_Reference (Loc,
3342 Prefix => New_Occurrence_Of (Ent_ATSD, Loc),
3343 Attribute_Name => Name_Address))),
3345 Make_Block_Statement (Loc,
3346 Declarations => User_Decls,
3347 Handled_Statement_Sequence => H),
3349 Make_Procedure_Call_Statement (Loc,
3350 Name => New_Occurrence_Of (RTE (RE_Thread_Body_Leave), Loc))),
3352 Exception_Handlers => Excep_Handlers));
3354 Analyze (Handled_Statement_Sequence (N));
3356 end Expand_Thread_Body;
3358 -- Start of processing for Expand_N_Subprogram_Body
3361 -- Set L to either the list of declarations if present, or
3362 -- to the list of statements if no declarations are present.
3363 -- This is used to insert new stuff at the start.
3365 if Is_Non_Empty_List (Declarations (N)) then
3366 L := Declarations (N);
3368 L := Statements (Handled_Statement_Sequence (N));
3371 -- Find entity for subprogram
3373 Body_Id := Defining_Entity (N);
3375 if Present (Corresponding_Spec (N)) then
3376 Spec_Id := Corresponding_Spec (N);
3381 -- Need poll on entry to subprogram if polling enabled. We only
3382 -- do this for non-empty subprograms, since it does not seem
3383 -- necessary to poll for a dummy null subprogram. Do not add polling
3384 -- point if calls to this subprogram will be inlined by the back-end,
3385 -- to avoid repeated polling points in nested inlinings.
3387 if Is_Non_Empty_List (L) then
3388 if Is_Inlined (Spec_Id)
3389 and then Front_End_Inlining
3390 and then Optimization_Level > 1
3394 Generate_Poll_Call (First (L));
3398 -- If this is a Pure function which has any parameters whose root
3399 -- type is System.Address, reset the Pure indication, since it will
3400 -- likely cause incorrect code to be generated as the parameter is
3401 -- probably a pointer, and the fact that the same pointer is passed
3402 -- does not mean that the same value is being referenced.
3404 -- Note that if the programmer gave an explicit Pure_Function pragma,
3405 -- then we believe the programmer, and leave the subprogram Pure.
3407 -- This code should probably be at the freeze point, so that it
3408 -- happens even on a -gnatc (or more importantly -gnatt) compile
3409 -- so that the semantic tree has Is_Pure set properly ???
3411 if Is_Pure (Spec_Id)
3412 and then Is_Subprogram (Spec_Id)
3413 and then not Has_Pragma_Pure_Function (Spec_Id)
3416 F : Entity_Id := First_Formal (Spec_Id);
3419 while Present (F) loop
3420 if Is_Descendent_Of_Address (Etype (F)) then
3421 Set_Is_Pure (Spec_Id, False);
3423 if Spec_Id /= Body_Id then
3424 Set_Is_Pure (Body_Id, False);
3435 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
3437 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
3439 F : Entity_Id := First_Formal (Spec_Id);
3440 V : constant Boolean := Validity_Checks_On;
3443 -- We turn off validity checking, since we do not want any
3444 -- check on the initializing value itself (which we know
3445 -- may well be invalid!)
3447 Validity_Checks_On := False;
3449 -- Loop through formals
3451 while Present (F) loop
3452 if Is_Scalar_Type (Etype (F))
3453 and then Ekind (F) = E_Out_Parameter
3455 Insert_Before_And_Analyze (First (L),
3456 Make_Assignment_Statement (Loc,
3457 Name => New_Occurrence_Of (F, Loc),
3458 Expression => Get_Simple_Init_Val (Etype (F), Loc)));
3464 Validity_Checks_On := V;
3468 Scop := Scope (Spec_Id);
3470 -- Add discriminal renamings to protected subprograms.
3471 -- Install new discriminals for expansion of the next
3472 -- subprogram of this protected type, if any.
3474 if Is_List_Member (N)
3475 and then Present (Parent (List_Containing (N)))
3476 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
3478 Add_Discriminal_Declarations
3479 (Declarations (N), Scop, Name_uObject, Loc);
3480 Add_Private_Declarations (Declarations (N), Scop, Name_uObject, Loc);
3482 -- Associate privals and discriminals with the next protected
3483 -- operation body to be expanded. These are used to expand
3484 -- references to private data objects and discriminants,
3487 Next_Op := Next_Protected_Operation (N);
3489 if Present (Next_Op) then
3490 Dec := Parent (Base_Type (Scop));
3491 Set_Privals (Dec, Next_Op, Loc);
3492 Set_Discriminals (Dec);
3496 -- Clear out statement list for stubbed procedure
3498 if Present (Corresponding_Spec (N)) then
3499 Set_Elaboration_Flag (N, Spec_Id);
3501 if Convention (Spec_Id) = Convention_Stubbed
3502 or else Is_Eliminated (Spec_Id)
3504 Set_Declarations (N, Empty_List);
3505 Set_Handled_Statement_Sequence (N,
3506 Make_Handled_Sequence_Of_Statements (Loc,
3507 Statements => New_List (
3508 Make_Null_Statement (Loc))));
3513 -- Returns_By_Ref flag is normally set when the subprogram is frozen
3514 -- but subprograms with no specs are not frozen
3517 Typ : constant Entity_Id := Etype (Spec_Id);
3518 Utyp : constant Entity_Id := Underlying_Type (Typ);
3521 if not Acts_As_Spec (N)
3522 and then Nkind (Parent (Parent (Spec_Id))) /=
3523 N_Subprogram_Body_Stub
3527 elsif Is_Return_By_Reference_Type (Typ) then
3528 Set_Returns_By_Ref (Spec_Id);
3530 elsif Present (Utyp) and then Controlled_Type (Utyp) then
3531 Set_Returns_By_Ref (Spec_Id);
3535 -- For a procedure, we add a return for all possible syntactic ends
3536 -- of the subprogram. Note that reanalysis is not necessary in this
3537 -- case since it would require a lot of work and accomplish nothing.
3539 if Ekind (Spec_Id) = E_Procedure
3540 or else Ekind (Spec_Id) = E_Generic_Procedure
3542 Add_Return (Statements (H));
3544 if Present (Exception_Handlers (H)) then
3545 Except_H := First_Non_Pragma (Exception_Handlers (H));
3547 while Present (Except_H) loop
3548 Add_Return (Statements (Except_H));
3549 Next_Non_Pragma (Except_H);
3553 -- For a function, we must deal with the case where there is at least
3554 -- one missing return. What we do is to wrap the entire body of the
3555 -- function in a block:
3568 -- raise Program_Error;
3571 -- This approach is necessary because the raise must be signalled
3572 -- to the caller, not handled by any local handler (RM 6.4(11)).
3574 -- Note: we do not need to analyze the constructed sequence here,
3575 -- since it has no handler, and an attempt to analyze the handled
3576 -- statement sequence twice is risky in various ways (e.g. the
3577 -- issue of expanding cleanup actions twice).
3579 elsif Has_Missing_Return (Spec_Id) then
3581 Hloc : constant Source_Ptr := Sloc (H);
3582 Blok : constant Node_Id :=
3583 Make_Block_Statement (Hloc,
3584 Handled_Statement_Sequence => H);
3585 Rais : constant Node_Id :=
3586 Make_Raise_Program_Error (Hloc,
3587 Reason => PE_Missing_Return);
3590 Set_Handled_Statement_Sequence (N,
3591 Make_Handled_Sequence_Of_Statements (Hloc,
3592 Statements => New_List (Blok, Rais)));
3594 New_Scope (Spec_Id);
3601 -- If subprogram contains a parameterless recursive call, then we may
3602 -- have an infinite recursion, so see if we can generate code to check
3603 -- for this possibility if storage checks are not suppressed.
3605 if Ekind (Spec_Id) = E_Procedure
3606 and then Has_Recursive_Call (Spec_Id)
3607 and then not Storage_Checks_Suppressed (Spec_Id)
3609 Detect_Infinite_Recursion (N, Spec_Id);
3612 -- Finally, if we are in Normalize_Scalars mode, then any scalar out
3613 -- parameters must be initialized to the appropriate default value.
3615 if Ekind (Spec_Id) = E_Procedure and then Normalize_Scalars then
3622 Formal := First_Formal (Spec_Id);
3624 while Present (Formal) loop
3625 Floc := Sloc (Formal);
3627 if Ekind (Formal) = E_Out_Parameter
3628 and then Is_Scalar_Type (Etype (Formal))
3631 Make_Assignment_Statement (Floc,
3632 Name => New_Occurrence_Of (Formal, Floc),
3634 Get_Simple_Init_Val (Etype (Formal), Floc));
3635 Prepend (Stm, Declarations (N));
3639 Next_Formal (Formal);
3644 -- Deal with thread body
3646 if Is_Thread_Body (Spec_Id) then
3650 -- If the subprogram does not have pending instantiations, then we
3651 -- must generate the subprogram descriptor now, since the code for
3652 -- the subprogram is complete, and this is our last chance. However
3653 -- if there are pending instantiations, then the code is not
3654 -- complete, and we will delay the generation.
3656 if Is_Subprogram (Spec_Id)
3657 and then not Delay_Subprogram_Descriptors (Spec_Id)
3659 Generate_Subprogram_Descriptor_For_Subprogram (N, Spec_Id);
3662 -- Set to encode entity names in package body before gigi is called
3664 Qualify_Entity_Names (N);
3665 end Expand_N_Subprogram_Body;
3667 -----------------------------------
3668 -- Expand_N_Subprogram_Body_Stub --
3669 -----------------------------------
3671 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
3673 if Present (Corresponding_Body (N)) then
3674 Expand_N_Subprogram_Body (
3675 Unit_Declaration_Node (Corresponding_Body (N)));
3677 end Expand_N_Subprogram_Body_Stub;
3679 -------------------------------------
3680 -- Expand_N_Subprogram_Declaration --
3681 -------------------------------------
3683 -- If the declaration appears within a protected body, it is a private
3684 -- operation of the protected type. We must create the corresponding
3685 -- protected subprogram an associated formals. For a normal protected
3686 -- operation, this is done when expanding the protected type declaration.
3688 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
3689 Loc : constant Source_Ptr := Sloc (N);
3690 Subp : constant Entity_Id := Defining_Entity (N);
3691 Scop : constant Entity_Id := Scope (Subp);
3692 Prot_Decl : Node_Id;
3694 Prot_Id : Entity_Id;
3697 -- Deal with case of protected subprogram. Do not generate
3698 -- protected operation if operation is flagged as eliminated.
3700 if Is_List_Member (N)
3701 and then Present (Parent (List_Containing (N)))
3702 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
3703 and then Is_Protected_Type (Scop)
3705 if No (Protected_Body_Subprogram (Subp))
3706 and then not Is_Eliminated (Subp)
3709 Make_Subprogram_Declaration (Loc,
3711 Build_Protected_Sub_Specification
3712 (N, Scop, Unprotected => True));
3714 -- The protected subprogram is declared outside of the protected
3715 -- body. Given that the body has frozen all entities so far, we
3716 -- analyze the subprogram and perform freezing actions explicitly.
3717 -- If the body is a subunit, the insertion point is before the
3718 -- stub in the parent.
3720 Prot_Bod := Parent (List_Containing (N));
3722 if Nkind (Parent (Prot_Bod)) = N_Subunit then
3723 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
3726 Insert_Before (Prot_Bod, Prot_Decl);
3727 Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
3729 New_Scope (Scope (Scop));
3730 Analyze (Prot_Decl);
3731 Create_Extra_Formals (Prot_Id);
3732 Set_Protected_Body_Subprogram (Subp, Prot_Id);
3736 end Expand_N_Subprogram_Declaration;
3738 ---------------------------------------
3739 -- Expand_Protected_Object_Reference --
3740 ---------------------------------------
3742 function Expand_Protected_Object_Reference
3747 Loc : constant Source_Ptr := Sloc (N);
3754 Rec := Make_Identifier (Loc, Name_uObject);
3755 Set_Etype (Rec, Corresponding_Record_Type (Scop));
3757 -- Find enclosing protected operation, and retrieve its first
3758 -- parameter, which denotes the enclosing protected object.
3759 -- If the enclosing operation is an entry, we are immediately
3760 -- within the protected body, and we can retrieve the object
3761 -- from the service entries procedure. A barrier function has
3762 -- has the same signature as an entry. A barrier function is
3763 -- compiled within the protected object, but unlike protected
3764 -- operations its never needs locks, so that its protected body
3765 -- subprogram points to itself.
3767 Proc := Current_Scope;
3769 while Present (Proc)
3770 and then Scope (Proc) /= Scop
3772 Proc := Scope (Proc);
3775 Corr := Protected_Body_Subprogram (Proc);
3779 -- Previous error left expansion incomplete.
3780 -- Nothing to do on this call.
3787 (First (Parameter_Specifications (Parent (Corr))));
3789 if Is_Subprogram (Proc)
3790 and then Proc /= Corr
3792 -- Protected function or procedure
3794 Set_Entity (Rec, Param);
3796 -- Rec is a reference to an entity which will not be in scope
3797 -- when the call is reanalyzed, and needs no further analysis.
3802 -- Entry or barrier function for entry body.
3803 -- The first parameter of the entry body procedure is a
3804 -- pointer to the object. We create a local variable
3805 -- of the proper type, duplicating what is done to define
3806 -- _object later on.
3810 Obj_Ptr : constant Entity_Id := Make_Defining_Identifier (Loc,
3812 New_Internal_Name ('T'));
3816 Make_Full_Type_Declaration (Loc,
3817 Defining_Identifier => Obj_Ptr,
3819 Make_Access_To_Object_Definition (Loc,
3820 Subtype_Indication =>
3822 (Corresponding_Record_Type (Scop), Loc))));
3824 Insert_Actions (N, Decls);
3825 Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
3828 Make_Explicit_Dereference (Loc,
3829 Unchecked_Convert_To (Obj_Ptr,
3830 New_Occurrence_Of (Param, Loc)));
3832 -- Analyze new actual. Other actuals in calls are already
3833 -- analyzed and the list of actuals is not renalyzed after
3836 Set_Parent (Rec, N);
3842 end Expand_Protected_Object_Reference;
3844 --------------------------------------
3845 -- Expand_Protected_Subprogram_Call --
3846 --------------------------------------
3848 procedure Expand_Protected_Subprogram_Call
3856 -- If the protected object is not an enclosing scope, this is
3857 -- an inter-object function call. Inter-object procedure
3858 -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
3859 -- The call is intra-object only if the subprogram being
3860 -- called is in the protected body being compiled, and if the
3861 -- protected object in the call is statically the enclosing type.
3862 -- The object may be an component of some other data structure,
3863 -- in which case this must be handled as an inter-object call.
3865 if not In_Open_Scopes (Scop)
3866 or else not Is_Entity_Name (Name (N))
3868 if Nkind (Name (N)) = N_Selected_Component then
3869 Rec := Prefix (Name (N));
3872 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
3873 Rec := Prefix (Prefix (Name (N)));
3876 Build_Protected_Subprogram_Call (N,
3877 Name => New_Occurrence_Of (Subp, Sloc (N)),
3878 Rec => Convert_Concurrent (Rec, Etype (Rec)),
3882 Rec := Expand_Protected_Object_Reference (N, Scop);
3888 Build_Protected_Subprogram_Call (N,
3897 -- If it is a function call it can appear in elaboration code and
3898 -- the called entity must be frozen here.
3900 if Ekind (Subp) = E_Function then
3901 Freeze_Expression (Name (N));
3903 end Expand_Protected_Subprogram_Call;
3905 -----------------------
3906 -- Freeze_Subprogram --
3907 -----------------------
3909 procedure Freeze_Subprogram (N : Node_Id) is
3910 E : constant Entity_Id := Entity (N);
3913 -- When a primitive is frozen, enter its name in the corresponding
3914 -- dispatch table. If the DTC_Entity field is not set this is an
3915 -- overridden primitive that can be ignored. We suppress the
3916 -- initialization of the dispatch table entry when Java_VM because
3917 -- the dispatching mechanism is handled internally by the JVM.
3919 if Is_Dispatching_Operation (E)
3920 and then not Is_Abstract (E)
3921 and then Present (DTC_Entity (E))
3922 and then not Is_CPP_Class (Scope (DTC_Entity (E)))
3923 and then not Java_VM
3925 Check_Overriding_Operation (E);
3926 Insert_After (N, Fill_DT_Entry (Sloc (N), E));
3929 -- Mark functions that return by reference. Note that it cannot be
3930 -- part of the normal semantic analysis of the spec since the
3931 -- underlying returned type may not be known yet (for private types)
3934 Typ : constant Entity_Id := Etype (E);
3935 Utyp : constant Entity_Id := Underlying_Type (Typ);
3938 if Is_Return_By_Reference_Type (Typ) then
3939 Set_Returns_By_Ref (E);
3941 elsif Present (Utyp) and then Controlled_Type (Utyp) then
3942 Set_Returns_By_Ref (E);
3945 end Freeze_Subprogram;
OSDN Git Service
