1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2003, 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 Rtsfind; use Rtsfind;
56 with Sem_Ch6; use Sem_Ch6;
57 with Sem_Ch8; use Sem_Ch8;
58 with Sem_Ch12; use Sem_Ch12;
59 with Sem_Ch13; use Sem_Ch13;
60 with Sem_Disp; use Sem_Disp;
61 with Sem_Dist; use Sem_Dist;
62 with Sem_Eval; use Sem_Eval;
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 procedure Expand_Inlined_Call
130 Orig_Subp : Entity_Id);
131 -- If called subprogram can be inlined by the front-end, retrieve the
132 -- analyzed body, replace formals with actuals and expand call in place.
133 -- Generate thunks for actuals that are expressions, and insert the
134 -- corresponding constant declarations before the call. If the original
135 -- call is to a derived operation, the return type is the one of the
136 -- derived operation, but the body is that of the original, so return
137 -- expressions in the body must be converted to the desired type (which
138 -- is simply not noted in the tree without inline expansion).
140 function Expand_Protected_Object_Reference
145 procedure Expand_Protected_Subprogram_Call
149 -- A call to a protected subprogram within the protected object may appear
150 -- as a regular call. The list of actuals must be expanded to contain a
151 -- reference to the object itself, and the call becomes a call to the
152 -- corresponding protected subprogram.
154 --------------------------------
155 -- Check_Overriding_Operation --
156 --------------------------------
158 procedure Check_Overriding_Operation (Subp : Entity_Id) is
159 Typ : constant Entity_Id := Find_Dispatching_Type (Subp);
160 Op_List : constant Elist_Id := Primitive_Operations (Typ);
166 if Is_Derived_Type (Typ)
167 and then not Is_Private_Type (Typ)
168 and then In_Open_Scopes (Scope (Etype (Typ)))
169 and then Typ = Base_Type (Typ)
171 -- Subp overrides an inherited private operation if there is
172 -- an inherited operation with a different name than Subp (see
173 -- Derive_Subprogram) whose Alias is a hidden subprogram with
174 -- the same name as Subp.
176 Op_Elmt := First_Elmt (Op_List);
177 while Present (Op_Elmt) loop
178 Prim_Op := Node (Op_Elmt);
179 Par_Op := Alias (Prim_Op);
182 and then not Comes_From_Source (Prim_Op)
183 and then Chars (Prim_Op) /= Chars (Par_Op)
184 and then Chars (Par_Op) = Chars (Subp)
185 and then Is_Hidden (Par_Op)
186 and then Type_Conformant (Prim_Op, Subp)
188 Set_DT_Position (Subp, DT_Position (Prim_Op));
194 end Check_Overriding_Operation;
196 -------------------------------
197 -- Detect_Infinite_Recursion --
198 -------------------------------
200 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id) is
201 Loc : constant Source_Ptr := Sloc (N);
203 Var_List : constant Elist_Id := New_Elmt_List;
204 -- List of globals referenced by body of procedure
206 Call_List : constant Elist_Id := New_Elmt_List;
207 -- List of recursive calls in body of procedure
209 Shad_List : constant Elist_Id := New_Elmt_List;
210 -- List of entity id's for entities created to capture the
211 -- value of referenced globals on entry to the procedure.
213 Scop : constant Uint := Scope_Depth (Spec);
214 -- This is used to record the scope depth of the current
215 -- procedure, so that we can identify global references.
217 Max_Vars : constant := 4;
218 -- Do not test more than four global variables
220 Count_Vars : Natural := 0;
221 -- Count variables found so far
233 function Process (Nod : Node_Id) return Traverse_Result;
234 -- Function to traverse the subprogram body (using Traverse_Func)
240 function Process (Nod : Node_Id) return Traverse_Result is
244 if Nkind (Nod) = N_Procedure_Call_Statement then
246 -- Case of one of the detected recursive calls
248 if Is_Entity_Name (Name (Nod))
249 and then Has_Recursive_Call (Entity (Name (Nod)))
250 and then Entity (Name (Nod)) = Spec
252 Append_Elmt (Nod, Call_List);
255 -- Any other procedure call may have side effects
261 -- A call to a pure function can always be ignored
263 elsif Nkind (Nod) = N_Function_Call
264 and then Is_Entity_Name (Name (Nod))
265 and then Is_Pure (Entity (Name (Nod)))
269 -- Case of an identifier reference
271 elsif Nkind (Nod) = N_Identifier then
274 -- If no entity, then ignore the reference
276 -- Not clear why this can happen. To investigate, remove this
277 -- test and look at the crash that occurs here in 3401-004 ???
282 -- Ignore entities with no Scope, again not clear how this
283 -- can happen, to investigate, look at 4108-008 ???
285 elsif No (Scope (Ent)) then
288 -- Ignore the reference if not to a more global object
290 elsif Scope_Depth (Scope (Ent)) >= Scop then
293 -- References to types, exceptions and constants are always OK
296 or else Ekind (Ent) = E_Exception
297 or else Ekind (Ent) = E_Constant
301 -- If other than a non-volatile scalar variable, we have some
302 -- kind of global reference (e.g. to a function) that we cannot
303 -- deal with so we forget the attempt.
305 elsif Ekind (Ent) /= E_Variable
306 or else not Is_Scalar_Type (Etype (Ent))
307 or else Treat_As_Volatile (Ent)
311 -- Otherwise we have a reference to a global scalar
314 -- Loop through global entities already detected
316 Elm := First_Elmt (Var_List);
318 -- If not detected before, record this new global reference
321 Count_Vars := Count_Vars + 1;
323 if Count_Vars <= Max_Vars then
324 Append_Elmt (Entity (Nod), Var_List);
331 -- If recorded before, ignore
333 elsif Node (Elm) = Entity (Nod) then
336 -- Otherwise keep looking
346 -- For all other node kinds, recursively visit syntactic children
353 function Traverse_Body is new Traverse_Func;
355 -- Start of processing for Detect_Infinite_Recursion
358 -- Do not attempt detection in No_Implicit_Conditional mode,
359 -- since we won't be able to generate the code to handle the
360 -- recursion in any case.
362 if Restrictions (No_Implicit_Conditionals) then
366 -- Otherwise do traversal and quit if we get abandon signal
368 if Traverse_Body (N) = Abandon then
371 -- We must have a call, since Has_Recursive_Call was set. If not
372 -- just ignore (this is only an error check, so if we have a funny
373 -- situation, due to bugs or errors, we do not want to bomb!)
375 elsif Is_Empty_Elmt_List (Call_List) then
379 -- Here is the case where we detect recursion at compile time
381 -- Push our current scope for analyzing the declarations and
382 -- code that we will insert for the checking.
386 -- This loop builds temporary variables for each of the
387 -- referenced globals, so that at the end of the loop the
388 -- list Shad_List contains these temporaries in one-to-one
389 -- correspondence with the elements in Var_List.
392 Elm := First_Elmt (Var_List);
393 while Present (Elm) loop
396 Make_Defining_Identifier (Loc,
397 Chars => New_Internal_Name ('S'));
398 Append_Elmt (Ent, Shad_List);
400 -- Insert a declaration for this temporary at the start of
401 -- the declarations for the procedure. The temporaries are
402 -- declared as constant objects initialized to the current
403 -- values of the corresponding temporaries.
406 Make_Object_Declaration (Loc,
407 Defining_Identifier => Ent,
408 Object_Definition => New_Occurrence_Of (Etype (Var), Loc),
409 Constant_Present => True,
410 Expression => New_Occurrence_Of (Var, Loc));
413 Prepend (Decl, Declarations (N));
415 Insert_After (Last, Decl);
423 -- Loop through calls
425 Call := First_Elmt (Call_List);
426 while Present (Call) loop
428 -- Build a predicate expression of the form
431 -- and then global1 = temp1
432 -- and then global2 = temp2
435 -- This predicate determines if any of the global values
436 -- referenced by the procedure have changed since the
437 -- current call, if not an infinite recursion is assured.
439 Test := New_Occurrence_Of (Standard_True, Loc);
441 Elm1 := First_Elmt (Var_List);
442 Elm2 := First_Elmt (Shad_List);
443 while Present (Elm1) loop
449 Left_Opnd => New_Occurrence_Of (Node (Elm1), Loc),
450 Right_Opnd => New_Occurrence_Of (Node (Elm2), Loc)));
456 -- Now we replace the call with the sequence
458 -- if no-changes (see above) then
459 -- raise Storage_Error;
464 Rewrite (Node (Call),
465 Make_If_Statement (Loc,
467 Then_Statements => New_List (
468 Make_Raise_Storage_Error (Loc,
469 Reason => SE_Infinite_Recursion)),
471 Else_Statements => New_List (
472 Relocate_Node (Node (Call)))));
474 Analyze (Node (Call));
479 -- Remove temporary scope stack entry used for analysis
482 end Detect_Infinite_Recursion;
488 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id) is
489 Loc : constant Source_Ptr := Sloc (N);
494 E_Formal : Entity_Id;
496 procedure Add_Call_By_Copy_Code;
497 -- For cases where the parameter must be passed by copy, this routine
498 -- generates a temporary variable into which the actual is copied and
499 -- then passes this as the parameter. For an OUT or IN OUT parameter,
500 -- an assignment is also generated to copy the result back. The call
501 -- also takes care of any constraint checks required for the type
502 -- conversion case (on both the way in and the way out).
504 procedure Add_Packed_Call_By_Copy_Code;
505 -- This is used when the actual involves a reference to an element
506 -- of a packed array, where we can appropriately use a simpler
507 -- approach than the full call by copy code. We just copy the value
508 -- in and out of an appropriate temporary.
510 procedure Check_Fortran_Logical;
511 -- A value of type Logical that is passed through a formal parameter
512 -- must be normalized because .TRUE. usually does not have the same
513 -- representation as True. We assume that .FALSE. = False = 0.
514 -- What about functions that return a logical type ???
516 function Make_Var (Actual : Node_Id) return Entity_Id;
517 -- Returns an entity that refers to the given actual parameter,
518 -- Actual (not including any type conversion). If Actual is an
519 -- entity name, then this entity is returned unchanged, otherwise
520 -- a renaming is created to provide an entity for the actual.
522 procedure Reset_Packed_Prefix;
523 -- The expansion of a packed array component reference is delayed in
524 -- the context of a call. Now we need to complete the expansion, so we
525 -- unmark the analyzed bits in all prefixes.
527 ---------------------------
528 -- Add_Call_By_Copy_Code --
529 ---------------------------
531 procedure Add_Call_By_Copy_Code is
540 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
542 if Nkind (Actual) = N_Type_Conversion then
543 V_Typ := Etype (Expression (Actual));
545 -- If the formal is an (in-)out parameter, capture the name
546 -- of the variable in order to build the post-call assignment.
548 Var := Make_Var (Expression (Actual));
550 Crep := not Same_Representation
551 (Etype (Formal), Etype (Expression (Actual)));
554 V_Typ := Etype (Actual);
555 Var := Make_Var (Actual);
559 -- Setup initialization for case of in out parameter, or an out
560 -- parameter where the formal is an unconstrained array (in the
561 -- latter case, we have to pass in an object with bounds).
563 if Ekind (Formal) = E_In_Out_Parameter
564 or else (Is_Array_Type (Etype (Formal))
566 not Is_Constrained (Etype (Formal)))
568 if Nkind (Actual) = N_Type_Conversion then
569 if Conversion_OK (Actual) then
570 Init := OK_Convert_To
571 (Etype (Formal), New_Occurrence_Of (Var, Loc));
574 (Etype (Formal), New_Occurrence_Of (Var, Loc));
577 Init := New_Occurrence_Of (Var, Loc);
580 -- An initialization is created for packed conversions as
581 -- actuals for out parameters to enable Make_Object_Declaration
582 -- to determine the proper subtype for N_Node. Note that this
583 -- is wasteful because the extra copying on the call side is
584 -- not required for such out parameters. ???
586 elsif Ekind (Formal) = E_Out_Parameter
587 and then Nkind (Actual) = N_Type_Conversion
588 and then (Is_Bit_Packed_Array (Etype (Formal))
590 Is_Bit_Packed_Array (Etype (Expression (Actual))))
592 if Conversion_OK (Actual) then
594 OK_Convert_To (Etype (Formal), New_Occurrence_Of (Var, Loc));
597 Convert_To (Etype (Formal), New_Occurrence_Of (Var, Loc));
604 Make_Object_Declaration (Loc,
605 Defining_Identifier => Temp,
607 New_Occurrence_Of (Etype (Formal), Loc),
609 Set_Assignment_OK (N_Node);
610 Insert_Action (N, N_Node);
612 -- Now, normally the deal here is that we use the defining
613 -- identifier created by that object declaration. There is
614 -- one exception to this. In the change of representation case
615 -- the above declaration will end up looking like:
617 -- temp : type := identifier;
619 -- And in this case we might as well use the identifier directly
620 -- and eliminate the temporary. Note that the analysis of the
621 -- declaration was not a waste of time in that case, since it is
622 -- what generated the necessary change of representation code. If
623 -- the change of representation introduced additional code, as in
624 -- a fixed-integer conversion, the expression is not an identifier
628 and then Present (Expression (N_Node))
629 and then Is_Entity_Name (Expression (N_Node))
631 Temp := Entity (Expression (N_Node));
632 Rewrite (N_Node, Make_Null_Statement (Loc));
635 -- For IN parameter, all we do is to replace the actual
637 if Ekind (Formal) = E_In_Parameter then
638 Rewrite (Actual, New_Reference_To (Temp, Loc));
641 -- Processing for OUT or IN OUT parameter
644 -- If type conversion, use reverse conversion on exit
646 if Nkind (Actual) = N_Type_Conversion then
647 if Conversion_OK (Actual) then
648 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
650 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
653 Expr := New_Occurrence_Of (Temp, Loc);
656 Rewrite (Actual, New_Reference_To (Temp, Loc));
659 Append_To (Post_Call,
660 Make_Assignment_Statement (Loc,
661 Name => New_Occurrence_Of (Var, Loc),
662 Expression => Expr));
664 Set_Assignment_OK (Name (Last (Post_Call)));
666 end Add_Call_By_Copy_Code;
668 ----------------------------------
669 -- Add_Packed_Call_By_Copy_Code --
670 ----------------------------------
672 procedure Add_Packed_Call_By_Copy_Code is
682 -- Prepare to generate code
684 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
685 Incod := Relocate_Node (Actual);
686 Outcod := New_Copy_Tree (Incod);
688 -- Generate declaration of temporary variable, initializing it
689 -- with the input parameter unless we have an OUT variable.
691 if Ekind (Formal) = E_Out_Parameter then
696 Make_Object_Declaration (Loc,
697 Defining_Identifier => Temp,
699 New_Occurrence_Of (Etype (Formal), Loc),
700 Expression => Incod));
702 -- The actual is simply a reference to the temporary
704 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
706 -- Generate copy out if OUT or IN OUT parameter
708 if Ekind (Formal) /= E_In_Parameter then
710 Rhs := New_Occurrence_Of (Temp, Loc);
712 -- Deal with conversion
714 if Nkind (Lhs) = N_Type_Conversion then
715 Lhs := Expression (Lhs);
716 Rhs := Convert_To (Etype (Actual), Rhs);
719 Append_To (Post_Call,
720 Make_Assignment_Statement (Loc,
724 end Add_Packed_Call_By_Copy_Code;
726 ---------------------------
727 -- Check_Fortran_Logical --
728 ---------------------------
730 procedure Check_Fortran_Logical is
731 Logical : constant Entity_Id := Etype (Formal);
734 -- Note: this is very incomplete, e.g. it does not handle arrays
735 -- of logical values. This is really not the right approach at all???)
738 if Convention (Subp) = Convention_Fortran
739 and then Root_Type (Etype (Formal)) = Standard_Boolean
740 and then Ekind (Formal) /= E_In_Parameter
742 Var := Make_Var (Actual);
743 Append_To (Post_Call,
744 Make_Assignment_Statement (Loc,
745 Name => New_Occurrence_Of (Var, Loc),
747 Unchecked_Convert_To (
750 Left_Opnd => New_Occurrence_Of (Var, Loc),
752 Unchecked_Convert_To (
754 New_Occurrence_Of (Standard_False, Loc))))));
756 end Check_Fortran_Logical;
762 function Make_Var (Actual : Node_Id) return Entity_Id is
766 if Is_Entity_Name (Actual) then
767 return Entity (Actual);
770 Var := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
773 Make_Object_Renaming_Declaration (Loc,
774 Defining_Identifier => Var,
776 New_Occurrence_Of (Etype (Actual), Loc),
777 Name => Relocate_Node (Actual));
779 Insert_Action (N, N_Node);
784 -------------------------
785 -- Reset_Packed_Prefix --
786 -------------------------
788 procedure Reset_Packed_Prefix is
789 Pfx : Node_Id := Actual;
793 Set_Analyzed (Pfx, False);
794 exit when Nkind (Pfx) /= N_Selected_Component
795 and then Nkind (Pfx) /= N_Indexed_Component;
798 end Reset_Packed_Prefix;
800 -- Start of processing for Expand_Actuals
803 Formal := First_Formal (Subp);
804 Actual := First_Actual (N);
806 Post_Call := New_List;
808 while Present (Formal) loop
809 E_Formal := Etype (Formal);
811 if Is_Scalar_Type (E_Formal)
812 or else Nkind (Actual) = N_Slice
814 Check_Fortran_Logical;
818 elsif Ekind (Formal) /= E_Out_Parameter then
820 -- The unusual case of the current instance of a protected type
821 -- requires special handling. This can only occur in the context
822 -- of a call within the body of a protected operation.
824 if Is_Entity_Name (Actual)
825 and then Ekind (Entity (Actual)) = E_Protected_Type
826 and then In_Open_Scopes (Entity (Actual))
828 if Scope (Subp) /= Entity (Actual) then
829 Error_Msg_N ("operation outside protected type may not "
830 & "call back its protected operations?", Actual);
834 Expand_Protected_Object_Reference (N, Entity (Actual)));
837 Apply_Constraint_Check (Actual, E_Formal);
839 -- Out parameter case. No constraint checks on access type
842 elsif Is_Access_Type (E_Formal) then
847 elsif Has_Discriminants (Base_Type (E_Formal))
848 or else Has_Non_Null_Base_Init_Proc (E_Formal)
850 Apply_Constraint_Check (Actual, E_Formal);
855 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
858 -- Processing for IN-OUT and OUT parameters
860 if Ekind (Formal) /= E_In_Parameter then
862 -- For type conversions of arrays, apply length/range checks
864 if Is_Array_Type (E_Formal)
865 and then Nkind (Actual) = N_Type_Conversion
867 if Is_Constrained (E_Formal) then
868 Apply_Length_Check (Expression (Actual), E_Formal);
870 Apply_Range_Check (Expression (Actual), E_Formal);
874 -- If argument is a type conversion for a type that is passed
875 -- by copy, then we must pass the parameter by copy.
877 if Nkind (Actual) = N_Type_Conversion
879 (Is_Numeric_Type (E_Formal)
880 or else Is_Access_Type (E_Formal)
881 or else Is_Enumeration_Type (E_Formal)
882 or else Is_Bit_Packed_Array (Etype (Formal))
883 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
885 -- Also pass by copy if change of representation
887 or else not Same_Representation
889 Etype (Expression (Actual))))
891 Add_Call_By_Copy_Code;
893 -- References to components of bit packed arrays are expanded
894 -- at this point, rather than at the point of analysis of the
895 -- actuals, to handle the expansion of the assignment to
896 -- [in] out parameters.
898 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
899 Add_Packed_Call_By_Copy_Code;
901 -- References to slices of bit packed arrays are expanded
903 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
904 Add_Call_By_Copy_Code;
906 -- References to possibly unaligned slices of arrays are expanded
908 elsif Is_Possibly_Unaligned_Slice (Actual) then
909 Add_Call_By_Copy_Code;
911 -- Deal with access types where the actual subtpe and the
912 -- formal subtype are not the same, requiring a check.
914 -- It is necessary to exclude tagged types because of "downward
915 -- conversion" errors and a strange assertion error in namet
916 -- from gnatf in bug 1215-001 ???
918 elsif Is_Access_Type (E_Formal)
919 and then not Same_Type (E_Formal, Etype (Actual))
920 and then not Is_Tagged_Type (Designated_Type (E_Formal))
922 Add_Call_By_Copy_Code;
924 elsif Is_Entity_Name (Actual)
925 and then Treat_As_Volatile (Entity (Actual))
926 and then not Is_Scalar_Type (Etype (Entity (Actual)))
927 and then not Treat_As_Volatile (E_Formal)
929 Add_Call_By_Copy_Code;
931 elsif Nkind (Actual) = N_Indexed_Component
932 and then Is_Entity_Name (Prefix (Actual))
933 and then Has_Volatile_Components (Entity (Prefix (Actual)))
935 Add_Call_By_Copy_Code;
938 -- Processing for IN parameters
941 -- For IN parameters is in the packed array case, we expand an
942 -- indexed component (the circuit in Exp_Ch4 deliberately left
943 -- indexed components appearing as actuals untouched, so that
944 -- the special processing above for the OUT and IN OUT cases
945 -- could be performed. We could make the test in Exp_Ch4 more
946 -- complex and have it detect the parameter mode, but it is
947 -- easier simply to handle all cases here.
949 if Nkind (Actual) = N_Indexed_Component
950 and then Is_Packed (Etype (Prefix (Actual)))
953 Expand_Packed_Element_Reference (Actual);
955 -- If we have a reference to a bit packed array, we copy it,
956 -- since the actual must be byte aligned.
958 -- Is this really necessary in all cases???
960 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
961 Add_Packed_Call_By_Copy_Code;
963 -- Similarly, we have to expand slices of packed arrays here
964 -- because the result must be byte aligned.
966 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
967 Add_Call_By_Copy_Code;
969 -- Only processing remaining is to pass by copy if this is a
970 -- reference to a possibly unaligned slice, since the caller
971 -- expects an appropriately aligned argument.
973 elsif Is_Possibly_Unaligned_Slice (Actual) then
974 Add_Call_By_Copy_Code;
978 Next_Formal (Formal);
979 Next_Actual (Actual);
982 -- Find right place to put post call stuff if it is present
984 if not Is_Empty_List (Post_Call) then
986 -- If call is not a list member, it must be the triggering
987 -- statement of a triggering alternative or an entry call
988 -- alternative, and we can add the post call stuff to the
989 -- corresponding statement list.
991 if not Is_List_Member (N) then
993 P : constant Node_Id := Parent (N);
996 pragma Assert (Nkind (P) = N_Triggering_Alternative
997 or else Nkind (P) = N_Entry_Call_Alternative);
999 if Is_Non_Empty_List (Statements (P)) then
1000 Insert_List_Before_And_Analyze
1001 (First (Statements (P)), Post_Call);
1003 Set_Statements (P, Post_Call);
1007 -- Otherwise, normal case where N is in a statement sequence,
1008 -- just put the post-call stuff after the call statement.
1011 Insert_Actions_After (N, Post_Call);
1015 -- The call node itself is re-analyzed in Expand_Call.
1023 -- This procedure handles expansion of function calls and procedure call
1024 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1025 -- Expand_N_Procedure_Call_Statement. Processing for calls includes:
1027 -- Replace call to Raise_Exception by Raise_Exception always if possible
1028 -- Provide values of actuals for all formals in Extra_Formals list
1029 -- Replace "call" to enumeration literal function by literal itself
1030 -- Rewrite call to predefined operator as operator
1031 -- Replace actuals to in-out parameters that are numeric conversions,
1032 -- with explicit assignment to temporaries before and after the call.
1033 -- Remove optional actuals if First_Optional_Parameter specified.
1035 -- Note that the list of actuals has been filled with default expressions
1036 -- during semantic analysis of the call. Only the extra actuals required
1037 -- for the 'Constrained attribute and for accessibility checks are added
1040 procedure Expand_Call (N : Node_Id) is
1041 Loc : constant Source_Ptr := Sloc (N);
1042 Remote : constant Boolean := Is_Remote_Call (N);
1044 Orig_Subp : Entity_Id := Empty;
1045 Parent_Subp : Entity_Id;
1046 Parent_Formal : Entity_Id;
1049 Prev : Node_Id := Empty;
1050 Prev_Orig : Node_Id;
1052 Extra_Actuals : List_Id := No_List;
1055 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1056 -- Adds one entry to the end of the actual parameter list. Used for
1057 -- default parameters and for extra actuals (for Extra_Formals).
1058 -- The argument is an N_Parameter_Association node.
1060 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1061 -- Adds an extra actual to the list of extra actuals. Expr
1062 -- is the expression for the value of the actual, EF is the
1063 -- entity for the extra formal.
1065 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1066 -- Within an instance, a type derived from a non-tagged formal derived
1067 -- type inherits from the original parent, not from the actual. This is
1068 -- tested in 4723-003. The current derivation mechanism has the derived
1069 -- type inherit from the actual, which is only correct outside of the
1070 -- instance. If the subprogram is inherited, we test for this particular
1071 -- case through a convoluted tree traversal before setting the proper
1072 -- subprogram to be called.
1074 --------------------------
1075 -- Add_Actual_Parameter --
1076 --------------------------
1078 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1079 Actual_Expr : constant Node_Id :=
1080 Explicit_Actual_Parameter (Insert_Param);
1083 -- Case of insertion is first named actual
1085 if No (Prev) or else
1086 Nkind (Parent (Prev)) /= N_Parameter_Association
1088 Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
1089 Set_First_Named_Actual (N, Actual_Expr);
1092 if not Present (Parameter_Associations (N)) then
1093 Set_Parameter_Associations (N, New_List);
1094 Append (Insert_Param, Parameter_Associations (N));
1097 Insert_After (Prev, Insert_Param);
1100 -- Case of insertion is not first named actual
1103 Set_Next_Named_Actual
1104 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1105 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1106 Append (Insert_Param, Parameter_Associations (N));
1109 Prev := Actual_Expr;
1110 end Add_Actual_Parameter;
1112 ----------------------
1113 -- Add_Extra_Actual --
1114 ----------------------
1116 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1117 Loc : constant Source_Ptr := Sloc (Expr);
1120 if Extra_Actuals = No_List then
1121 Extra_Actuals := New_List;
1122 Set_Parent (Extra_Actuals, N);
1125 Append_To (Extra_Actuals,
1126 Make_Parameter_Association (Loc,
1127 Explicit_Actual_Parameter => Expr,
1129 Make_Identifier (Loc, Chars (EF))));
1131 Analyze_And_Resolve (Expr, Etype (EF));
1132 end Add_Extra_Actual;
1134 ---------------------------
1135 -- Inherited_From_Formal --
1136 ---------------------------
1138 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1140 Gen_Par : Entity_Id;
1141 Gen_Prim : Elist_Id;
1146 -- If the operation is inherited, it is attached to the corresponding
1147 -- type derivation. If the parent in the derivation is a generic
1148 -- actual, it is a subtype of the actual, and we have to recover the
1149 -- original derived type declaration to find the proper parent.
1151 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1152 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1153 or else Nkind (Type_Definition (Original_Node (Parent (S))))
1154 /= N_Derived_Type_Definition
1155 or else not In_Instance
1162 (Type_Definition (Original_Node (Parent (S)))));
1164 if Nkind (Indic) = N_Subtype_Indication then
1165 Par := Entity (Subtype_Mark (Indic));
1167 Par := Entity (Indic);
1171 if not Is_Generic_Actual_Type (Par)
1172 or else Is_Tagged_Type (Par)
1173 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1174 or else not In_Open_Scopes (Scope (Par))
1179 Gen_Par := Generic_Parent_Type (Parent (Par));
1182 -- If the generic parent type is still the generic type, this
1183 -- is a private formal, not a derived formal, and there are no
1184 -- operations inherited from the formal.
1186 if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
1190 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
1191 Elmt := First_Elmt (Gen_Prim);
1193 while Present (Elmt) loop
1194 if Chars (Node (Elmt)) = Chars (S) then
1200 F1 := First_Formal (S);
1201 F2 := First_Formal (Node (Elmt));
1204 and then Present (F2)
1207 if Etype (F1) = Etype (F2)
1208 or else Etype (F2) = Gen_Par
1214 exit; -- not the right subprogram
1226 raise Program_Error;
1227 end Inherited_From_Formal;
1229 -- Start of processing for Expand_Call
1232 -- Ignore if previous error
1234 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1238 -- Call using access to subprogram with explicit dereference
1240 if Nkind (Name (N)) = N_Explicit_Dereference then
1241 Subp := Etype (Name (N));
1242 Parent_Subp := Empty;
1244 -- Case of call to simple entry, where the Name is a selected component
1245 -- whose prefix is the task, and whose selector name is the entry name
1247 elsif Nkind (Name (N)) = N_Selected_Component then
1248 Subp := Entity (Selector_Name (Name (N)));
1249 Parent_Subp := Empty;
1251 -- Case of call to member of entry family, where Name is an indexed
1252 -- component, with the prefix being a selected component giving the
1253 -- task and entry family name, and the index being the entry index.
1255 elsif Nkind (Name (N)) = N_Indexed_Component then
1256 Subp := Entity (Selector_Name (Prefix (Name (N))));
1257 Parent_Subp := Empty;
1262 Subp := Entity (Name (N));
1263 Parent_Subp := Alias (Subp);
1265 -- Replace call to Raise_Exception by call to Raise_Exception_Always
1266 -- if we can tell that the first parameter cannot possibly be null.
1267 -- This helps optimization and also generation of warnings.
1269 if not Restrictions (No_Exception_Handlers)
1270 and then Is_RTE (Subp, RE_Raise_Exception)
1273 FA : constant Node_Id := Original_Node (First_Actual (N));
1276 -- The case we catch is where the first argument is obtained
1277 -- using the Identity attribute (which must always be non-null)
1279 if Nkind (FA) = N_Attribute_Reference
1280 and then Attribute_Name (FA) = Name_Identity
1282 Subp := RTE (RE_Raise_Exception_Always);
1283 Set_Entity (Name (N), Subp);
1288 if Ekind (Subp) = E_Entry then
1289 Parent_Subp := Empty;
1293 -- First step, compute extra actuals, corresponding to any
1294 -- Extra_Formals present. Note that we do not access Extra_Formals
1295 -- directly, instead we simply note the presence of the extra
1296 -- formals as we process the regular formals and collect the
1297 -- corresponding actuals in Extra_Actuals.
1299 -- We also generate any required range checks for actuals as we go
1300 -- through the loop, since this is a convenient place to do this.
1302 Formal := First_Formal (Subp);
1303 Actual := First_Actual (N);
1304 while Present (Formal) loop
1306 -- Generate range check if required (not activated yet ???)
1308 -- if Do_Range_Check (Actual) then
1309 -- Set_Do_Range_Check (Actual, False);
1310 -- Generate_Range_Check
1311 -- (Actual, Etype (Formal), CE_Range_Check_Failed);
1314 -- Prepare to examine current entry
1317 Prev_Orig := Original_Node (Prev);
1319 -- Create possible extra actual for constrained case. Usually,
1320 -- the extra actual is of the form actual'constrained, but since
1321 -- this attribute is only available for unconstrained records,
1322 -- TRUE is expanded if the type of the formal happens to be
1323 -- constrained (for instance when this procedure is inherited
1324 -- from an unconstrained record to a constrained one) or if the
1325 -- actual has no discriminant (its type is constrained). An
1326 -- exception to this is the case of a private type without
1327 -- discriminants. In this case we pass FALSE because the
1328 -- object has underlying discriminants with defaults.
1330 if Present (Extra_Constrained (Formal)) then
1331 if Ekind (Etype (Prev)) in Private_Kind
1332 and then not Has_Discriminants (Base_Type (Etype (Prev)))
1335 New_Occurrence_Of (Standard_False, Loc),
1336 Extra_Constrained (Formal));
1338 elsif Is_Constrained (Etype (Formal))
1339 or else not Has_Discriminants (Etype (Prev))
1342 New_Occurrence_Of (Standard_True, Loc),
1343 Extra_Constrained (Formal));
1346 -- If the actual is a type conversion, then the constrained
1347 -- test applies to the actual, not the target type.
1350 Act_Prev : Node_Id := Prev;
1353 -- Test for unchecked conversions as well, which can
1354 -- occur as out parameter actuals on calls to stream
1357 while Nkind (Act_Prev) = N_Type_Conversion
1358 or else Nkind (Act_Prev) = N_Unchecked_Type_Conversion
1360 Act_Prev := Expression (Act_Prev);
1364 Make_Attribute_Reference (Sloc (Prev),
1366 Duplicate_Subexpr_No_Checks
1367 (Act_Prev, Name_Req => True),
1368 Attribute_Name => Name_Constrained),
1369 Extra_Constrained (Formal));
1374 -- Create possible extra actual for accessibility level
1376 if Present (Extra_Accessibility (Formal)) then
1377 if Is_Entity_Name (Prev_Orig) then
1379 -- When passing an access parameter as the actual to another
1380 -- access parameter we need to pass along the actual's own
1381 -- associated access level parameter. This is done is we are
1382 -- in the scope of the formal access parameter (if this is an
1383 -- inlined body the extra formal is irrelevant).
1385 if Ekind (Entity (Prev_Orig)) in Formal_Kind
1386 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
1387 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
1390 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
1393 pragma Assert (Present (Parm_Ent));
1395 if Present (Extra_Accessibility (Parm_Ent)) then
1398 (Extra_Accessibility (Parm_Ent), Loc),
1399 Extra_Accessibility (Formal));
1401 -- If the actual access parameter does not have an
1402 -- associated extra formal providing its scope level,
1403 -- then treat the actual as having library-level
1408 Make_Integer_Literal (Loc,
1409 Intval => Scope_Depth (Standard_Standard)),
1410 Extra_Accessibility (Formal));
1414 -- The actual is a normal access value, so just pass the
1415 -- level of the actual's access type.
1419 Make_Integer_Literal (Loc,
1420 Intval => Type_Access_Level (Etype (Prev_Orig))),
1421 Extra_Accessibility (Formal));
1425 case Nkind (Prev_Orig) is
1427 when N_Attribute_Reference =>
1429 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
1431 -- For X'Access, pass on the level of the prefix X
1433 when Attribute_Access =>
1435 Make_Integer_Literal (Loc,
1437 Object_Access_Level (Prefix (Prev_Orig))),
1438 Extra_Accessibility (Formal));
1440 -- Treat the unchecked attributes as library-level
1442 when Attribute_Unchecked_Access |
1443 Attribute_Unrestricted_Access =>
1445 Make_Integer_Literal (Loc,
1446 Intval => Scope_Depth (Standard_Standard)),
1447 Extra_Accessibility (Formal));
1449 -- No other cases of attributes returning access
1450 -- values that can be passed to access parameters
1453 raise Program_Error;
1457 -- For allocators we pass the level of the execution of
1458 -- the called subprogram, which is one greater than the
1459 -- current scope level.
1463 Make_Integer_Literal (Loc,
1464 Scope_Depth (Current_Scope) + 1),
1465 Extra_Accessibility (Formal));
1467 -- For other cases we simply pass the level of the
1468 -- actual's access type.
1472 Make_Integer_Literal (Loc,
1473 Intval => Type_Access_Level (Etype (Prev_Orig))),
1474 Extra_Accessibility (Formal));
1480 -- Perform the check of 4.6(49) that prevents a null value
1481 -- from being passed as an actual to an access parameter.
1482 -- Note that the check is elided in the common cases of
1483 -- passing an access attribute or access parameter as an
1484 -- actual. Also, we currently don't enforce this check for
1485 -- expander-generated actuals and when -gnatdj is set.
1487 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
1488 or else Access_Checks_Suppressed (Subp)
1492 elsif Debug_Flag_J then
1495 elsif not Comes_From_Source (Prev) then
1498 elsif Is_Entity_Name (Prev)
1499 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
1503 elsif Nkind (Prev) = N_Allocator
1504 or else Nkind (Prev) = N_Attribute_Reference
1508 -- Suppress null checks when passing to access parameters
1509 -- of Java subprograms. (Should this be done for other
1510 -- foreign conventions as well ???)
1512 elsif Convention (Subp) = Convention_Java then
1518 Left_Opnd => Duplicate_Subexpr_No_Checks (Prev),
1519 Right_Opnd => Make_Null (Loc));
1520 Insert_Action (Prev,
1521 Make_Raise_Constraint_Error (Loc,
1523 Reason => CE_Access_Parameter_Is_Null));
1526 -- Perform appropriate validity checks on parameters that
1529 if Validity_Checks_On then
1530 if Ekind (Formal) = E_In_Parameter
1531 and then Validity_Check_In_Params
1533 -- If the actual is an indexed component of a packed
1534 -- type, it has not been expanded yet. It will be
1535 -- copied in the validity code that follows, and has
1536 -- to be expanded appropriately, so reanalyze it.
1538 if Nkind (Actual) = N_Indexed_Component then
1539 Set_Analyzed (Actual, False);
1542 Ensure_Valid (Actual);
1544 elsif Ekind (Formal) = E_In_Out_Parameter
1545 and then Validity_Check_In_Out_Params
1547 Ensure_Valid (Actual);
1551 -- For IN OUT and OUT parameters, ensure that subscripts are valid
1552 -- since this is a left side reference. We only do this for calls
1553 -- from the source program since we assume that compiler generated
1554 -- calls explicitly generate any required checks. We also need it
1555 -- only if we are doing standard validity checks, since clearly it
1556 -- is not needed if validity checks are off, and in subscript
1557 -- validity checking mode, all indexed components are checked with
1558 -- a call directly from Expand_N_Indexed_Component.
1560 if Comes_From_Source (N)
1561 and then Ekind (Formal) /= E_In_Parameter
1562 and then Validity_Checks_On
1563 and then Validity_Check_Default
1564 and then not Validity_Check_Subscripts
1566 Check_Valid_Lvalue_Subscripts (Actual);
1569 -- Mark any scalar OUT parameter that is a simple variable
1570 -- as no longer known to be valid (unless the type is always
1571 -- valid). This reflects the fact that if an OUT parameter
1572 -- is never set in a procedure, then it can become invalid
1573 -- on return from the procedure.
1575 if Ekind (Formal) = E_Out_Parameter
1576 and then Is_Entity_Name (Actual)
1577 and then Ekind (Entity (Actual)) = E_Variable
1578 and then not Is_Known_Valid (Etype (Actual))
1580 Set_Is_Known_Valid (Entity (Actual), False);
1583 -- For an OUT or IN OUT parameter of an access type, if the
1584 -- actual is an entity, then it is no longer known to be non-null.
1586 if Ekind (Formal) /= E_In_Parameter
1587 and then Is_Entity_Name (Actual)
1588 and then Is_Access_Type (Etype (Actual))
1590 Set_Is_Known_Non_Null (Entity (Actual), False);
1593 -- If the formal is class wide and the actual is an aggregate, force
1594 -- evaluation so that the back end who does not know about class-wide
1595 -- type, does not generate a temporary of the wrong size.
1597 if not Is_Class_Wide_Type (Etype (Formal)) then
1600 elsif Nkind (Actual) = N_Aggregate
1601 or else (Nkind (Actual) = N_Qualified_Expression
1602 and then Nkind (Expression (Actual)) = N_Aggregate)
1604 Force_Evaluation (Actual);
1607 -- In a remote call, if the formal is of a class-wide type, check
1608 -- that the actual meets the requirements described in E.4(18).
1611 and then Is_Class_Wide_Type (Etype (Formal))
1613 Insert_Action (Actual,
1614 Make_Implicit_If_Statement (N,
1617 Get_Remotely_Callable
1618 (Duplicate_Subexpr_Move_Checks (Actual))),
1619 Then_Statements => New_List (
1620 Make_Procedure_Call_Statement (Loc,
1621 New_Occurrence_Of (RTE
1622 (RE_Raise_Program_Error_For_E_4_18), Loc)))));
1625 Next_Actual (Actual);
1626 Next_Formal (Formal);
1629 -- If we are expanding a rhs of an assignement we need to check if
1630 -- tag propagation is needed. This code belongs theorically in Analyze
1631 -- Assignment but has to be done earlier (bottom-up) because the
1632 -- assignment might be transformed into a declaration for an uncons-
1633 -- trained value, if the expression is classwide.
1635 if Nkind (N) = N_Function_Call
1636 and then Is_Tag_Indeterminate (N)
1637 and then Is_Entity_Name (Name (N))
1640 Ass : Node_Id := Empty;
1643 if Nkind (Parent (N)) = N_Assignment_Statement then
1646 elsif Nkind (Parent (N)) = N_Qualified_Expression
1647 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
1649 Ass := Parent (Parent (N));
1653 and then Is_Class_Wide_Type (Etype (Name (Ass)))
1655 if Etype (N) /= Root_Type (Etype (Name (Ass))) then
1657 ("tag-indeterminate expression must have type&"
1658 & "('R'M 5.2 (6))", N, Root_Type (Etype (Name (Ass))));
1660 Propagate_Tag (Name (Ass), N);
1663 -- The call will be rewritten as a dispatching call, and
1664 -- expanded as such.
1671 -- Deals with Dispatch_Call if we still have a call, before expanding
1672 -- extra actuals since this will be done on the re-analysis of the
1673 -- dispatching call. Note that we do not try to shorten the actual
1674 -- list for a dispatching call, it would not make sense to do so.
1675 -- Expansion of dispatching calls is suppressed when Java_VM, because
1676 -- the JVM back end directly handles the generation of dispatching
1677 -- calls and would have to undo any expansion to an indirect call.
1679 if (Nkind (N) = N_Function_Call
1680 or else Nkind (N) = N_Procedure_Call_Statement)
1681 and then Present (Controlling_Argument (N))
1682 and then not Java_VM
1684 Expand_Dispatch_Call (N);
1686 -- The following return is worrisome. Is it really OK to
1687 -- skip all remaining processing in this procedure ???
1691 -- Similarly, expand calls to RCI subprograms on which pragma
1692 -- All_Calls_Remote applies. The rewriting will be reanalyzed
1693 -- later. Do this only when the call comes from source since we do
1694 -- not want such a rewritting to occur in expanded code.
1696 elsif Is_All_Remote_Call (N) then
1697 Expand_All_Calls_Remote_Subprogram_Call (N);
1699 -- Similarly, do not add extra actuals for an entry call whose entity
1700 -- is a protected procedure, or for an internal protected subprogram
1701 -- call, because it will be rewritten as a protected subprogram call
1702 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
1704 elsif Is_Protected_Type (Scope (Subp))
1705 and then (Ekind (Subp) = E_Procedure
1706 or else Ekind (Subp) = E_Function)
1710 -- During that loop we gathered the extra actuals (the ones that
1711 -- correspond to Extra_Formals), so now they can be appended.
1714 while Is_Non_Empty_List (Extra_Actuals) loop
1715 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
1719 if Ekind (Subp) = E_Procedure
1720 or else (Ekind (Subp) = E_Subprogram_Type
1721 and then Etype (Subp) = Standard_Void_Type)
1722 or else Is_Entry (Subp)
1724 Expand_Actuals (N, Subp);
1727 -- If the subprogram is a renaming, or if it is inherited, replace it
1728 -- in the call with the name of the actual subprogram being called.
1729 -- If this is a dispatching call, the run-time decides what to call.
1730 -- The Alias attribute does not apply to entries.
1732 if Nkind (N) /= N_Entry_Call_Statement
1733 and then No (Controlling_Argument (N))
1734 and then Present (Parent_Subp)
1736 if Present (Inherited_From_Formal (Subp)) then
1737 Parent_Subp := Inherited_From_Formal (Subp);
1739 while Present (Alias (Parent_Subp)) loop
1740 Parent_Subp := Alias (Parent_Subp);
1744 Set_Entity (Name (N), Parent_Subp);
1746 if Is_Abstract (Parent_Subp)
1747 and then not In_Instance
1750 ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
1753 -- Add an explicit conversion for parameter of the derived type.
1754 -- This is only done for scalar and access in-parameters. Others
1755 -- have been expanded in expand_actuals.
1757 Formal := First_Formal (Subp);
1758 Parent_Formal := First_Formal (Parent_Subp);
1759 Actual := First_Actual (N);
1761 -- It is not clear that conversion is needed for intrinsic
1762 -- subprograms, but it certainly is for those that are user-
1763 -- defined, and that can be inherited on derivation, namely
1764 -- unchecked conversion and deallocation.
1765 -- General case needs study ???
1767 if not Is_Intrinsic_Subprogram (Parent_Subp)
1768 or else Is_Generic_Instance (Parent_Subp)
1770 while Present (Formal) loop
1772 if Etype (Formal) /= Etype (Parent_Formal)
1773 and then Is_Scalar_Type (Etype (Formal))
1774 and then Ekind (Formal) = E_In_Parameter
1775 and then not Raises_Constraint_Error (Actual)
1778 OK_Convert_To (Etype (Parent_Formal),
1779 Relocate_Node (Actual)));
1782 Resolve (Actual, Etype (Parent_Formal));
1783 Enable_Range_Check (Actual);
1785 elsif Is_Access_Type (Etype (Formal))
1786 and then Base_Type (Etype (Parent_Formal))
1787 /= Base_Type (Etype (Actual))
1789 if Ekind (Formal) /= E_In_Parameter then
1791 Convert_To (Etype (Parent_Formal),
1792 Relocate_Node (Actual)));
1795 Resolve (Actual, Etype (Parent_Formal));
1798 Ekind (Etype (Parent_Formal)) = E_Anonymous_Access_Type
1799 and then Designated_Type (Etype (Parent_Formal))
1801 Designated_Type (Etype (Actual))
1802 and then not Is_Controlling_Formal (Formal)
1804 -- This unchecked conversion is not necessary unless
1805 -- inlining is enabled, because in that case the type
1806 -- mismatch may become visible in the body about to be
1810 Unchecked_Convert_To (Etype (Parent_Formal),
1811 Relocate_Node (Actual)));
1814 Resolve (Actual, Etype (Parent_Formal));
1818 Next_Formal (Formal);
1819 Next_Formal (Parent_Formal);
1820 Next_Actual (Actual);
1825 Subp := Parent_Subp;
1828 if Is_RTE (Subp, RE_Abort_Task) then
1829 Check_Restriction (No_Abort_Statements, N);
1832 -- Some more special cases for cases other than explicit dereference
1834 if Nkind (Name (N)) /= N_Explicit_Dereference then
1836 -- Calls to an enumeration literal are replaced by the literal
1837 -- This case occurs only when we have a call to a function that
1838 -- is a renaming of an enumeration literal. The normal case of
1839 -- a direct reference to an enumeration literal has already been
1840 -- been dealt with by Resolve_Call. If the function is itself
1841 -- inherited (see 7423-001) the literal of the parent type must
1842 -- be explicitly converted to the return type of the function.
1844 if Ekind (Subp) = E_Enumeration_Literal then
1845 if Base_Type (Etype (Subp)) /= Base_Type (Etype (N)) then
1847 (N, Convert_To (Etype (N), New_Occurrence_Of (Subp, Loc)));
1849 Rewrite (N, New_Occurrence_Of (Subp, Loc));
1855 -- Handle case of access to protected subprogram type
1858 if Ekind (Base_Type (Etype (Prefix (Name (N))))) =
1859 E_Access_Protected_Subprogram_Type
1861 -- If this is a call through an access to protected operation,
1862 -- the prefix has the form (object'address, operation'access).
1863 -- Rewrite as a for other protected calls: the object is the
1864 -- first parameter of the list of actuals.
1871 Ptr : constant Node_Id := Prefix (Name (N));
1873 T : constant Entity_Id :=
1874 Equivalent_Type (Base_Type (Etype (Ptr)));
1876 D_T : constant Entity_Id :=
1877 Designated_Type (Base_Type (Etype (Ptr)));
1880 Obj := Make_Selected_Component (Loc,
1881 Prefix => Unchecked_Convert_To (T, Ptr),
1882 Selector_Name => New_Occurrence_Of (First_Entity (T), Loc));
1884 Nam := Make_Selected_Component (Loc,
1885 Prefix => Unchecked_Convert_To (T, Ptr),
1886 Selector_Name => New_Occurrence_Of (
1887 Next_Entity (First_Entity (T)), Loc));
1889 Nam := Make_Explicit_Dereference (Loc, Nam);
1891 if Present (Parameter_Associations (N)) then
1892 Parm := Parameter_Associations (N);
1897 Prepend (Obj, Parm);
1899 if Etype (D_T) = Standard_Void_Type then
1900 Call := Make_Procedure_Call_Statement (Loc,
1902 Parameter_Associations => Parm);
1904 Call := Make_Function_Call (Loc,
1906 Parameter_Associations => Parm);
1909 Set_First_Named_Actual (Call, First_Named_Actual (N));
1910 Set_Etype (Call, Etype (D_T));
1912 -- We do not re-analyze the call to avoid infinite recursion.
1913 -- We analyze separately the prefix and the object, and set
1914 -- the checks on the prefix that would otherwise be emitted
1915 -- when resolving a call.
1919 Apply_Access_Check (Nam);
1926 -- If this is a call to an intrinsic subprogram, then perform the
1927 -- appropriate expansion to the corresponding tree node and we
1928 -- are all done (since after that the call is gone!)
1930 if Is_Intrinsic_Subprogram (Subp) then
1931 Expand_Intrinsic_Call (N, Subp);
1935 if Ekind (Subp) = E_Function
1936 or else Ekind (Subp) = E_Procedure
1938 if Is_Inlined (Subp) then
1942 Must_Inline : Boolean := False;
1943 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
1944 Scop : constant Entity_Id := Scope (Subp);
1947 -- Verify that the body to inline has already been seen,
1948 -- and that if the body is in the current unit the inlining
1949 -- does not occur earlier. This avoids order-of-elaboration
1950 -- problems in gigi.
1953 or else Nkind (Spec) /= N_Subprogram_Declaration
1954 or else No (Body_To_Inline (Spec))
1956 Must_Inline := False;
1958 -- If this an inherited function that returns a private
1959 -- type, do not inline if the full view is an unconstrained
1960 -- array, because such calls cannot be inlined.
1962 elsif Present (Orig_Subp)
1963 and then Is_Array_Type (Etype (Orig_Subp))
1964 and then not Is_Constrained (Etype (Orig_Subp))
1966 Must_Inline := False;
1968 -- If the subprogram comes from an instance in the same
1969 -- unit, and the instance is not yet frozen, inlining might
1970 -- trigger order-of-elaboration problems in gigi.
1972 elsif Is_Generic_Instance (Scop)
1973 and then Present (Freeze_Node (Scop))
1974 and then not Analyzed (Freeze_Node (Scop))
1976 Must_Inline := False;
1979 Bod := Body_To_Inline (Spec);
1981 if (In_Extended_Main_Code_Unit (N)
1982 or else In_Extended_Main_Code_Unit (Parent (N))
1983 or else Is_Always_Inlined (Subp))
1984 and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
1986 Earlier_In_Extended_Unit (Sloc (Bod), Loc))
1988 Must_Inline := True;
1990 -- If we are compiling a package body that is not the main
1991 -- unit, it must be for inlining/instantiation purposes,
1992 -- in which case we inline the call to insure that the same
1993 -- temporaries are generated when compiling the body by
1994 -- itself. Otherwise link errors can occur.
1996 elsif not (In_Extended_Main_Code_Unit (N))
1997 and then In_Package_Body
1999 Must_Inline := True;
2004 Expand_Inlined_Call (N, Subp, Orig_Subp);
2007 -- Let the back end handle it
2009 Add_Inlined_Body (Subp);
2011 if Front_End_Inlining
2012 and then Nkind (Spec) = N_Subprogram_Declaration
2013 and then (In_Extended_Main_Code_Unit (N))
2014 and then No (Body_To_Inline (Spec))
2015 and then not Has_Completion (Subp)
2016 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
2019 ("cannot inline& (body not seen yet)?",
2027 -- Check for a protected subprogram. This is either an intra-object
2028 -- call, or a protected function call. Protected procedure calls are
2029 -- rewritten as entry calls and handled accordingly.
2031 Scop := Scope (Subp);
2033 if Nkind (N) /= N_Entry_Call_Statement
2034 and then Is_Protected_Type (Scop)
2036 -- If the call is an internal one, it is rewritten as a call to
2037 -- to the corresponding unprotected subprogram.
2039 Expand_Protected_Subprogram_Call (N, Subp, Scop);
2042 -- Functions returning controlled objects need special attention
2044 if Controlled_Type (Etype (Subp))
2045 and then not Is_Return_By_Reference_Type (Etype (Subp))
2047 Expand_Ctrl_Function_Call (N);
2050 -- Test for First_Optional_Parameter, and if so, truncate parameter
2051 -- list if there are optional parameters at the trailing end.
2052 -- Note we never delete procedures for call via a pointer.
2054 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
2055 and then Present (First_Optional_Parameter (Subp))
2058 Last_Keep_Arg : Node_Id;
2061 -- Last_Keep_Arg will hold the last actual that should be
2062 -- retained. If it remains empty at the end, it means that
2063 -- all parameters are optional.
2065 Last_Keep_Arg := Empty;
2067 -- Find first optional parameter, must be present since we
2068 -- checked the validity of the parameter before setting it.
2070 Formal := First_Formal (Subp);
2071 Actual := First_Actual (N);
2072 while Formal /= First_Optional_Parameter (Subp) loop
2073 Last_Keep_Arg := Actual;
2074 Next_Formal (Formal);
2075 Next_Actual (Actual);
2078 -- We have Formal and Actual pointing to the first potentially
2079 -- droppable argument. We can drop all the trailing arguments
2080 -- whose actual matches the default. Note that we know that all
2081 -- remaining formals have defaults, because we checked that this
2082 -- requirement was met before setting First_Optional_Parameter.
2084 -- We use Fully_Conformant_Expressions to check for identity
2085 -- between formals and actuals, which may miss some cases, but
2086 -- on the other hand, this is only an optimization (if we fail
2087 -- to truncate a parameter it does not affect functionality).
2088 -- So if the default is 3 and the actual is 1+2, we consider
2089 -- them unequal, which hardly seems worrisome.
2091 while Present (Formal) loop
2092 if not Fully_Conformant_Expressions
2093 (Actual, Default_Value (Formal))
2095 Last_Keep_Arg := Actual;
2098 Next_Formal (Formal);
2099 Next_Actual (Actual);
2102 -- If no arguments, delete entire list, this is the easy case
2104 if No (Last_Keep_Arg) then
2105 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2106 Delete_Tree (Remove_Head (Parameter_Associations (N)));
2109 Set_Parameter_Associations (N, No_List);
2110 Set_First_Named_Actual (N, Empty);
2112 -- Case where at the last retained argument is positional. This
2113 -- is also an easy case, since the retained arguments are already
2114 -- in the right form, and we don't need to worry about the order
2115 -- of arguments that get eliminated.
2117 elsif Is_List_Member (Last_Keep_Arg) then
2118 while Present (Next (Last_Keep_Arg)) loop
2119 Delete_Tree (Remove_Next (Last_Keep_Arg));
2122 Set_First_Named_Actual (N, Empty);
2124 -- This is the annoying case where the last retained argument
2125 -- is a named parameter. Since the original arguments are not
2126 -- in declaration order, we may have to delete some fairly
2127 -- random collection of arguments.
2135 pragma Warnings (Off, Discard);
2138 -- First step, remove all the named parameters from the
2139 -- list (they are still chained using First_Named_Actual
2140 -- and Next_Named_Actual, so we have not lost them!)
2142 Temp := First (Parameter_Associations (N));
2144 -- Case of all parameters named, remove them all
2146 if Nkind (Temp) = N_Parameter_Association then
2147 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2148 Temp := Remove_Head (Parameter_Associations (N));
2151 -- Case of mixed positional/named, remove named parameters
2154 while Nkind (Next (Temp)) /= N_Parameter_Association loop
2158 while Present (Next (Temp)) loop
2159 Discard := Remove_Next (Temp);
2163 -- Now we loop through the named parameters, till we get
2164 -- to the last one to be retained, adding them to the list.
2165 -- Note that the Next_Named_Actual list does not need to be
2166 -- touched since we are only reordering them on the actual
2167 -- parameter association list.
2169 Passoc := Parent (First_Named_Actual (N));
2171 Temp := Relocate_Node (Passoc);
2173 (Parameter_Associations (N), Temp);
2175 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
2176 Passoc := Parent (Next_Named_Actual (Passoc));
2179 Set_Next_Named_Actual (Temp, Empty);
2182 Temp := Next_Named_Actual (Passoc);
2183 exit when No (Temp);
2184 Set_Next_Named_Actual
2185 (Passoc, Next_Named_Actual (Parent (Temp)));
2194 --------------------------
2195 -- Expand_Inlined_Call --
2196 --------------------------
2198 procedure Expand_Inlined_Call
2201 Orig_Subp : Entity_Id)
2203 Loc : constant Source_Ptr := Sloc (N);
2204 Is_Predef : constant Boolean :=
2205 Is_Predefined_File_Name
2206 (Unit_File_Name (Get_Source_Unit (Subp)));
2207 Orig_Bod : constant Node_Id :=
2208 Body_To_Inline (Unit_Declaration_Node (Subp));
2213 Exit_Lab : Entity_Id := Empty;
2220 Ret_Type : Entity_Id;
2223 Temp_Typ : Entity_Id;
2225 procedure Make_Exit_Label;
2226 -- Build declaration for exit label to be used in Return statements.
2228 function Process_Formals (N : Node_Id) return Traverse_Result;
2229 -- Replace occurrence of a formal with the corresponding actual, or
2230 -- the thunk generated for it.
2232 function Process_Sloc (Nod : Node_Id) return Traverse_Result;
2233 -- If the call being expanded is that of an internal subprogram,
2234 -- set the sloc of the generated block to that of the call itself,
2235 -- so that the expansion is skipped by the -next- command in gdb.
2236 -- Same processing for a subprogram in a predefined file, e.g.
2237 -- Ada.Tags. If Debug_Generated_Code is true, suppress this change
2238 -- to simplify our own development.
2240 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
2241 -- If the function body is a single expression, replace call with
2242 -- expression, else insert block appropriately.
2244 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
2245 -- If procedure body has no local variables, inline body without
2246 -- creating block, otherwise rewrite call with block.
2248 ---------------------
2249 -- Make_Exit_Label --
2250 ---------------------
2252 procedure Make_Exit_Label is
2254 -- Create exit label for subprogram, if one doesn't exist yet.
2256 if No (Exit_Lab) then
2257 Lab_Id := Make_Identifier (Loc, New_Internal_Name ('L'));
2259 Make_Defining_Identifier (Loc, Chars (Lab_Id)));
2260 Exit_Lab := Make_Label (Loc, Lab_Id);
2263 Make_Implicit_Label_Declaration (Loc,
2264 Defining_Identifier => Entity (Lab_Id),
2265 Label_Construct => Exit_Lab);
2267 end Make_Exit_Label;
2269 ---------------------
2270 -- Process_Formals --
2271 ---------------------
2273 function Process_Formals (N : Node_Id) return Traverse_Result is
2279 if Is_Entity_Name (N)
2280 and then Present (Entity (N))
2285 and then Scope (E) = Subp
2287 A := Renamed_Object (E);
2289 if Is_Entity_Name (A) then
2290 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
2292 elsif Nkind (A) = N_Defining_Identifier then
2293 Rewrite (N, New_Occurrence_Of (A, Loc));
2295 else -- numeric literal
2296 Rewrite (N, New_Copy (A));
2302 elsif Nkind (N) = N_Return_Statement then
2304 if No (Expression (N)) then
2306 Rewrite (N, Make_Goto_Statement (Loc,
2307 Name => New_Copy (Lab_Id)));
2310 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
2311 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
2313 -- Function body is a single expression. No need for
2319 Num_Ret := Num_Ret + 1;
2323 -- Because of the presence of private types, the views of the
2324 -- expression and the context may be different, so place an
2325 -- unchecked conversion to the context type to avoid spurious
2326 -- errors, eg. when the expression is a numeric literal and
2327 -- the context is private. If the expression is an aggregate,
2328 -- use a qualified expression, because an aggregate is not a
2329 -- legal argument of a conversion.
2331 if Nkind (Expression (N)) = N_Aggregate
2332 or else Nkind (Expression (N)) = N_Null
2335 Make_Qualified_Expression (Sloc (N),
2336 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
2337 Expression => Relocate_Node (Expression (N)));
2340 Unchecked_Convert_To
2341 (Ret_Type, Relocate_Node (Expression (N)));
2344 if Nkind (Targ) = N_Defining_Identifier then
2346 Make_Assignment_Statement (Loc,
2347 Name => New_Occurrence_Of (Targ, Loc),
2348 Expression => Ret));
2351 Make_Assignment_Statement (Loc,
2352 Name => New_Copy (Targ),
2353 Expression => Ret));
2356 Set_Assignment_OK (Name (N));
2358 if Present (Exit_Lab) then
2360 Make_Goto_Statement (Loc,
2361 Name => New_Copy (Lab_Id)));
2367 -- Remove pragma Unreferenced since it may refer to formals that
2368 -- are not visible in the inlined body, and in any case we will
2369 -- not be posting warnings on the inlined body so it is unneeded.
2371 elsif Nkind (N) = N_Pragma
2372 and then Chars (N) = Name_Unreferenced
2374 Rewrite (N, Make_Null_Statement (Sloc (N)));
2380 end Process_Formals;
2382 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
2388 function Process_Sloc (Nod : Node_Id) return Traverse_Result is
2390 if not Debug_Generated_Code then
2391 Set_Sloc (Nod, Sloc (N));
2392 Set_Comes_From_Source (Nod, False);
2398 procedure Reset_Slocs is new Traverse_Proc (Process_Sloc);
2400 ---------------------------
2401 -- Rewrite_Function_Call --
2402 ---------------------------
2404 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
2405 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
2406 Fst : constant Node_Id := First (Statements (HSS));
2409 -- Optimize simple case: function body is a single return statement,
2410 -- which has been expanded into an assignment.
2412 if Is_Empty_List (Declarations (Blk))
2413 and then Nkind (Fst) = N_Assignment_Statement
2414 and then No (Next (Fst))
2417 -- The function call may have been rewritten as the temporary
2418 -- that holds the result of the call, in which case remove the
2419 -- now useless declaration.
2421 if Nkind (N) = N_Identifier
2422 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2424 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
2427 Rewrite (N, Expression (Fst));
2429 elsif Nkind (N) = N_Identifier
2430 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2433 -- The block assigns the result of the call to the temporary.
2435 Insert_After (Parent (Entity (N)), Blk);
2437 elsif Nkind (Parent (N)) = N_Assignment_Statement
2438 and then Is_Entity_Name (Name (Parent (N)))
2441 -- Replace assignment with the block
2443 Rewrite (Parent (N), Blk);
2445 elsif Nkind (Parent (N)) = N_Object_Declaration then
2446 Set_Expression (Parent (N), Empty);
2447 Insert_After (Parent (N), Blk);
2449 end Rewrite_Function_Call;
2451 ----------------------------
2452 -- Rewrite_Procedure_Call --
2453 ----------------------------
2455 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
2456 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
2459 if Is_Empty_List (Declarations (Blk)) then
2460 Insert_List_After (N, Statements (HSS));
2461 Rewrite (N, Make_Null_Statement (Loc));
2465 end Rewrite_Procedure_Call;
2467 -- Start of processing for Expand_Inlined_Call
2470 -- Check for special case of To_Address call, and if so, just
2471 -- do an unchecked conversion instead of expanding the call.
2472 -- Not only is this more efficient, but it also avoids a
2473 -- problem with order of elaboration when address clauses
2474 -- are inlined (address expr elaborated at wrong point).
2476 if Subp = RTE (RE_To_Address) then
2478 Unchecked_Convert_To
2480 Relocate_Node (First_Actual (N))));
2484 if Nkind (Orig_Bod) = N_Defining_Identifier then
2486 -- Subprogram is a renaming_as_body. Calls appearing after the
2487 -- renaming can be replaced with calls to the renamed entity
2488 -- directly, because the subprograms are subtype conformant.
2490 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
2494 -- Use generic machinery to copy body of inlined subprogram, as if it
2495 -- were an instantiation, resetting source locations appropriately, so
2496 -- that nested inlined calls appear in the main unit.
2498 Save_Env (Subp, Empty);
2499 Set_Copied_Sloc_For_Inlined_Body (N, Defining_Entity (Orig_Bod));
2501 Bod := Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
2503 Make_Block_Statement (Loc,
2504 Declarations => Declarations (Bod),
2505 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
2507 if No (Declarations (Bod)) then
2508 Set_Declarations (Blk, New_List);
2511 -- If this is a derived function, establish the proper return type.
2513 if Present (Orig_Subp)
2514 and then Orig_Subp /= Subp
2516 Ret_Type := Etype (Orig_Subp);
2518 Ret_Type := Etype (Subp);
2521 F := First_Formal (Subp);
2522 A := First_Actual (N);
2524 -- Create temporaries for the actuals that are expressions, or that
2525 -- are scalars and require copying to preserve semantics.
2527 while Present (F) loop
2528 if Present (Renamed_Object (F)) then
2529 Error_Msg_N (" cannot inline call to recursive subprogram", N);
2533 -- If the argument may be a controlling argument in a call within
2534 -- the inlined body, we must preserve its classwide nature to
2535 -- insure that dynamic dispatching take place subsequently.
2536 -- If the formal has a constraint it must be preserved to retain
2537 -- the semantics of the body.
2539 if Is_Class_Wide_Type (Etype (F))
2540 or else (Is_Access_Type (Etype (F))
2542 Is_Class_Wide_Type (Designated_Type (Etype (F))))
2544 Temp_Typ := Etype (F);
2546 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
2547 and then Etype (F) /= Base_Type (Etype (F))
2549 Temp_Typ := Etype (F);
2552 Temp_Typ := Etype (A);
2555 -- If the actual is a simple name or a literal, no need to
2556 -- create a temporary, object can be used directly.
2558 if (Is_Entity_Name (A)
2560 (not Is_Scalar_Type (Etype (A))
2561 or else Ekind (Entity (A)) = E_Enumeration_Literal))
2563 or else Nkind (A) = N_Real_Literal
2564 or else Nkind (A) = N_Integer_Literal
2565 or else Nkind (A) = N_Character_Literal
2567 if Etype (F) /= Etype (A) then
2569 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
2571 Set_Renamed_Object (F, A);
2576 Make_Defining_Identifier (Loc,
2577 Chars => New_Internal_Name ('C'));
2579 -- If the actual for an in/in-out parameter is a view conversion,
2580 -- make it into an unchecked conversion, given that an untagged
2581 -- type conversion is not a proper object for a renaming.
2583 -- In-out conversions that involve real conversions have already
2584 -- been transformed in Expand_Actuals.
2586 if Nkind (A) = N_Type_Conversion
2587 and then Ekind (F) /= E_In_Parameter
2589 New_A := Make_Unchecked_Type_Conversion (Loc,
2590 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
2591 Expression => Relocate_Node (Expression (A)));
2593 elsif Etype (F) /= Etype (A) then
2594 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
2595 Temp_Typ := Etype (F);
2598 New_A := Relocate_Node (A);
2601 Set_Sloc (New_A, Sloc (N));
2603 if Ekind (F) = E_In_Parameter
2604 and then not Is_Limited_Type (Etype (A))
2607 Make_Object_Declaration (Loc,
2608 Defining_Identifier => Temp,
2609 Constant_Present => True,
2610 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
2611 Expression => New_A);
2614 Make_Object_Renaming_Declaration (Loc,
2615 Defining_Identifier => Temp,
2616 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
2620 Prepend (Decl, Declarations (Blk));
2621 Set_Renamed_Object (F, Temp);
2628 -- Establish target of function call. If context is not assignment or
2629 -- declaration, create a temporary as a target. The declaration for
2630 -- the temporary may be subsequently optimized away if the body is a
2631 -- single expression, or if the left-hand side of the assignment is
2634 if Ekind (Subp) = E_Function then
2635 if Nkind (Parent (N)) = N_Assignment_Statement
2636 and then Is_Entity_Name (Name (Parent (N)))
2638 Targ := Name (Parent (N));
2641 -- Replace call with temporary, and create its declaration.
2644 Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
2647 Make_Object_Declaration (Loc,
2648 Defining_Identifier => Temp,
2649 Object_Definition =>
2650 New_Occurrence_Of (Ret_Type, Loc));
2652 Set_No_Initialization (Decl);
2653 Insert_Action (N, Decl);
2654 Rewrite (N, New_Occurrence_Of (Temp, Loc));
2659 -- Traverse the tree and replace formals with actuals or their thunks.
2660 -- Attach block to tree before analysis and rewriting.
2662 Replace_Formals (Blk);
2663 Set_Parent (Blk, N);
2665 if not Comes_From_Source (Subp)
2671 if Present (Exit_Lab) then
2673 -- If the body was a single expression, the single return statement
2674 -- and the corresponding label are useless.
2678 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
2681 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
2683 Append (Lab_Decl, (Declarations (Blk)));
2684 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
2688 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
2689 -- conflicting private views that Gigi would ignore. If this is a
2690 -- predefined unit, analyze with checks off, as is done in the non-
2691 -- inlined run-time units.
2694 I_Flag : constant Boolean := In_Inlined_Body;
2697 In_Inlined_Body := True;
2701 Style : constant Boolean := Style_Check;
2703 Style_Check := False;
2704 Analyze (Blk, Suppress => All_Checks);
2705 Style_Check := Style;
2712 In_Inlined_Body := I_Flag;
2715 if Ekind (Subp) = E_Procedure then
2716 Rewrite_Procedure_Call (N, Blk);
2718 Rewrite_Function_Call (N, Blk);
2723 -- Cleanup mapping between formals and actuals, for other expansions.
2725 F := First_Formal (Subp);
2727 while Present (F) loop
2728 Set_Renamed_Object (F, Empty);
2731 end Expand_Inlined_Call;
2733 ----------------------------
2734 -- Expand_N_Function_Call --
2735 ----------------------------
2737 procedure Expand_N_Function_Call (N : Node_Id) is
2738 Typ : constant Entity_Id := Etype (N);
2740 function Returned_By_Reference return Boolean;
2741 -- If the return type is returned through the secondary stack. that is
2742 -- by reference, we don't want to create a temp to force stack checking.
2744 function Returned_By_Reference return Boolean is
2745 S : Entity_Id := Current_Scope;
2748 if Is_Return_By_Reference_Type (Typ) then
2751 elsif Nkind (Parent (N)) /= N_Return_Statement then
2754 elsif Requires_Transient_Scope (Typ) then
2756 -- Verify that the return type of the enclosing function has
2757 -- the same constrained status as that of the expression.
2759 while Ekind (S) /= E_Function loop
2763 return Is_Constrained (Typ) = Is_Constrained (Etype (S));
2767 end Returned_By_Reference;
2769 -- Start of processing for Expand_N_Function_Call
2772 -- A special check. If stack checking is enabled, and the return type
2773 -- might generate a large temporary, and the call is not the right
2774 -- side of an assignment, then generate an explicit temporary. We do
2775 -- this because otherwise gigi may generate a large temporary on the
2776 -- fly and this can cause trouble with stack checking.
2778 if May_Generate_Large_Temp (Typ)
2779 and then Nkind (Parent (N)) /= N_Assignment_Statement
2781 (Nkind (Parent (N)) /= N_Qualified_Expression
2782 or else Nkind (Parent (Parent (N))) /= N_Assignment_Statement)
2784 (Nkind (Parent (N)) /= N_Object_Declaration
2785 or else Expression (Parent (N)) /= N)
2786 and then not Returned_By_Reference
2788 -- Note: it might be thought that it would be OK to use a call to
2789 -- Force_Evaluation here, but that's not good enough, because that
2790 -- results in a 'Reference construct that may still need a temporary.
2793 Loc : constant Source_Ptr := Sloc (N);
2794 Temp_Obj : constant Entity_Id :=
2795 Make_Defining_Identifier (Loc,
2796 Chars => New_Internal_Name ('F'));
2797 Temp_Typ : Entity_Id := Typ;
2804 if Is_Tagged_Type (Typ)
2805 and then Present (Controlling_Argument (N))
2807 if Nkind (Parent (N)) /= N_Procedure_Call_Statement
2808 and then Nkind (Parent (N)) /= N_Function_Call
2810 -- If this is a tag-indeterminate call, the object must
2813 if Is_Tag_Indeterminate (N) then
2814 Temp_Typ := Class_Wide_Type (Typ);
2818 -- If this is a dispatching call that is itself the
2819 -- controlling argument of an enclosing call, the nominal
2820 -- subtype of the object that replaces it must be classwide,
2821 -- so that dispatching will take place properly. If it is
2822 -- not a controlling argument, the object is not classwide.
2824 Proc := Entity (Name (Parent (N)));
2825 F := First_Formal (Proc);
2826 A := First_Actual (Parent (N));
2833 if Is_Controlling_Formal (F) then
2834 Temp_Typ := Class_Wide_Type (Typ);
2840 Make_Object_Declaration (Loc,
2841 Defining_Identifier => Temp_Obj,
2842 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
2843 Constant_Present => True,
2844 Expression => Relocate_Node (N));
2845 Set_Assignment_OK (Decl);
2847 Insert_Actions (N, New_List (Decl));
2848 Rewrite (N, New_Occurrence_Of (Temp_Obj, Loc));
2851 -- Normal case, expand the call
2856 end Expand_N_Function_Call;
2858 ---------------------------------------
2859 -- Expand_N_Procedure_Call_Statement --
2860 ---------------------------------------
2862 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
2865 end Expand_N_Procedure_Call_Statement;
2867 ------------------------------
2868 -- Expand_N_Subprogram_Body --
2869 ------------------------------
2871 -- Add poll call if ATC polling is enabled
2873 -- Add return statement if last statement in body is not a return
2874 -- statement (this makes things easier on Gigi which does not want
2875 -- to have to handle a missing return).
2877 -- Add call to Activate_Tasks if body is a task activator
2879 -- Deal with possible detection of infinite recursion
2881 -- Eliminate body completely if convention stubbed
2883 -- Encode entity names within body, since we will not need to reference
2884 -- these entities any longer in the front end.
2886 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
2888 -- Reset Pure indication if any parameter has root type System.Address
2892 procedure Expand_N_Subprogram_Body (N : Node_Id) is
2893 Loc : constant Source_Ptr := Sloc (N);
2894 H : constant Node_Id := Handled_Statement_Sequence (N);
2895 Body_Id : Entity_Id;
2896 Spec_Id : Entity_Id;
2903 procedure Add_Return (S : List_Id);
2904 -- Append a return statement to the statement sequence S if the last
2905 -- statement is not already a return or a goto statement. Note that
2906 -- the latter test is not critical, it does not matter if we add a
2907 -- few extra returns, since they get eliminated anyway later on.
2909 procedure Expand_Thread_Body;
2910 -- Perform required expansion of a thread body
2916 procedure Add_Return (S : List_Id) is
2918 if not Is_Transfer (Last (S)) then
2920 -- The source location for the return is the end label
2921 -- of the procedure in all cases. This is a bit odd when
2922 -- there are exception handlers, but not much else we can do.
2924 Append_To (S, Make_Return_Statement (Sloc (End_Label (H))));
2928 ------------------------
2929 -- Expand_Thread_Body --
2930 ------------------------
2932 -- The required expansion of a thread body is as follows
2934 -- procedure <thread body procedure name> is
2936 -- _Secondary_Stack : aliased
2937 -- Storage_Elements.Storage_Array
2938 -- (1 .. Storage_Offset (Sec_Stack_Size));
2939 -- for _Secondary_Stack'Alignment use Standard'Maximum_Alignment;
2941 -- _Process_ATSD : aliased System.Threads.ATSD;
2944 -- System.Threads.Thread_Body_Enter;
2945 -- (_Secondary_Stack'Address,
2946 -- _Secondary_Stack'Length,
2947 -- _Process_ATSD'Address);
2950 -- <user declarations>
2952 -- <user statements>
2953 -- <user exception handlers>
2956 -- System.Threads.Thread_Body_Leave;
2959 -- when E : others =>
2960 -- System.Threads.Thread_Body_Exceptional_Exit (E);
2963 -- Note the exception handler is omitted if pragma Restriction
2964 -- No_Exception_Handlers is currently active.
2966 procedure Expand_Thread_Body is
2967 User_Decls : constant List_Id := Declarations (N);
2968 Sec_Stack_Len : Node_Id;
2970 TB_Pragma : constant Node_Id :=
2971 Get_Rep_Pragma (Spec_Id, Name_Thread_Body);
2974 Ent_ATSD : Entity_Id;
2978 Decl_ATSD : Node_Id;
2980 Excep_Handlers : List_Id;
2983 New_Scope (Spec_Id);
2985 -- Get proper setting for secondary stack size
2987 if List_Length (Pragma_Argument_Associations (TB_Pragma)) = 2 then
2989 Expression (Last (Pragma_Argument_Associations (TB_Pragma)));
2992 Make_Integer_Literal (Loc,
2995 (Constant_Value (RTE (RE_Default_Secondary_Stack_Size))));
2998 Sec_Stack_Len := Convert_To (RTE (RE_Storage_Offset), Sec_Stack_Len);
3000 -- Build and set declarations for the wrapped thread body
3002 Ent_SS := Make_Defining_Identifier (Loc, Name_uSecondary_Stack);
3003 Ent_ATSD := Make_Defining_Identifier (Loc, Name_uProcess_ATSD);
3006 Make_Object_Declaration (Loc,
3007 Defining_Identifier => Ent_SS,
3008 Aliased_Present => True,
3009 Object_Definition =>
3010 Make_Subtype_Indication (Loc,
3012 New_Occurrence_Of (RTE (RE_Storage_Array), Loc),
3014 Make_Index_Or_Discriminant_Constraint (Loc,
3015 Constraints => New_List (
3017 Low_Bound => Make_Integer_Literal (Loc, 1),
3018 High_Bound => Sec_Stack_Len)))));
3021 Make_Object_Declaration (Loc,
3022 Defining_Identifier => Ent_ATSD,
3023 Aliased_Present => True,
3024 Object_Definition => New_Occurrence_Of (RTE (RE_ATSD), Loc));
3026 Set_Declarations (N, New_List (Decl_SS, Decl_ATSD));
3028 Analyze (Decl_ATSD);
3029 Set_Alignment (Ent_SS, UI_From_Int (Maximum_Alignment));
3031 -- Create new exception handler
3033 if Restrictions (No_Exception_Handlers) then
3034 Excep_Handlers := No_List;
3037 Check_Restriction (No_Exception_Handlers, N);
3039 Ent_EO := Make_Defining_Identifier (Loc, Name_uE);
3041 Excep_Handlers := New_List (
3042 Make_Exception_Handler (Loc,
3043 Choice_Parameter => Ent_EO,
3044 Exception_Choices => New_List (
3045 Make_Others_Choice (Loc)),
3046 Statements => New_List (
3047 Make_Procedure_Call_Statement (Loc,
3050 (RTE (RE_Thread_Body_Exceptional_Exit), Loc),
3051 Parameter_Associations => New_List (
3052 New_Occurrence_Of (Ent_EO, Loc))))));
3055 -- Now build new handled statement sequence and analyze it
3057 Set_Handled_Statement_Sequence (N,
3058 Make_Handled_Sequence_Of_Statements (Loc,
3059 Statements => New_List (
3061 Make_Procedure_Call_Statement (Loc,
3062 Name => New_Occurrence_Of (RTE (RE_Thread_Body_Enter), Loc),
3063 Parameter_Associations => New_List (
3065 Make_Attribute_Reference (Loc,
3066 Prefix => New_Occurrence_Of (Ent_SS, Loc),
3067 Attribute_Name => Name_Address),
3069 Make_Attribute_Reference (Loc,
3070 Prefix => New_Occurrence_Of (Ent_SS, Loc),
3071 Attribute_Name => Name_Length),
3073 Make_Attribute_Reference (Loc,
3074 Prefix => New_Occurrence_Of (Ent_ATSD, Loc),
3075 Attribute_Name => Name_Address))),
3077 Make_Block_Statement (Loc,
3078 Declarations => User_Decls,
3079 Handled_Statement_Sequence => H),
3081 Make_Procedure_Call_Statement (Loc,
3082 Name => New_Occurrence_Of (RTE (RE_Thread_Body_Leave), Loc))),
3084 Exception_Handlers => Excep_Handlers));
3086 Analyze (Handled_Statement_Sequence (N));
3088 end Expand_Thread_Body;
3090 -- Start of processing for Expand_N_Subprogram_Body
3093 -- Set L to either the list of declarations if present, or
3094 -- to the list of statements if no declarations are present.
3095 -- This is used to insert new stuff at the start.
3097 if Is_Non_Empty_List (Declarations (N)) then
3098 L := Declarations (N);
3100 L := Statements (Handled_Statement_Sequence (N));
3103 -- Need poll on entry to subprogram if polling enabled. We only
3104 -- do this for non-empty subprograms, since it does not seem
3105 -- necessary to poll for a dummy null subprogram.
3107 if Is_Non_Empty_List (L) then
3108 Generate_Poll_Call (First (L));
3111 -- Find entity for subprogram
3113 Body_Id := Defining_Entity (N);
3115 if Present (Corresponding_Spec (N)) then
3116 Spec_Id := Corresponding_Spec (N);
3121 -- If this is a Pure function which has any parameters whose root
3122 -- type is System.Address, reset the Pure indication, since it will
3123 -- likely cause incorrect code to be generated.
3125 if Is_Pure (Spec_Id)
3126 and then Is_Subprogram (Spec_Id)
3127 and then not Has_Pragma_Pure_Function (Spec_Id)
3130 F : Entity_Id := First_Formal (Spec_Id);
3133 while Present (F) loop
3134 if Is_RTE (Root_Type (Etype (F)), RE_Address) then
3135 Set_Is_Pure (Spec_Id, False);
3137 if Spec_Id /= Body_Id then
3138 Set_Is_Pure (Body_Id, False);
3149 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
3151 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
3153 F : Entity_Id := First_Formal (Spec_Id);
3154 V : constant Boolean := Validity_Checks_On;
3157 -- We turn off validity checking, since we do not want any
3158 -- check on the initializing value itself (which we know
3159 -- may well be invalid!)
3161 Validity_Checks_On := False;
3163 -- Loop through formals
3165 while Present (F) loop
3166 if Is_Scalar_Type (Etype (F))
3167 and then Ekind (F) = E_Out_Parameter
3169 Insert_Before_And_Analyze (First (L),
3170 Make_Assignment_Statement (Loc,
3171 Name => New_Occurrence_Of (F, Loc),
3172 Expression => Get_Simple_Init_Val (Etype (F), Loc)));
3178 Validity_Checks_On := V;
3182 -- Clear out statement list for stubbed procedure
3184 if Present (Corresponding_Spec (N)) then
3185 Set_Elaboration_Flag (N, Spec_Id);
3187 if Convention (Spec_Id) = Convention_Stubbed
3188 or else Is_Eliminated (Spec_Id)
3190 Set_Declarations (N, Empty_List);
3191 Set_Handled_Statement_Sequence (N,
3192 Make_Handled_Sequence_Of_Statements (Loc,
3193 Statements => New_List (
3194 Make_Null_Statement (Loc))));
3199 Scop := Scope (Spec_Id);
3201 -- Returns_By_Ref flag is normally set when the subprogram is frozen
3202 -- but subprograms with no specs are not frozen
3205 Typ : constant Entity_Id := Etype (Spec_Id);
3206 Utyp : constant Entity_Id := Underlying_Type (Typ);
3209 if not Acts_As_Spec (N)
3210 and then Nkind (Parent (Parent (Spec_Id))) /=
3211 N_Subprogram_Body_Stub
3215 elsif Is_Return_By_Reference_Type (Typ) then
3216 Set_Returns_By_Ref (Spec_Id);
3218 elsif Present (Utyp) and then Controlled_Type (Utyp) then
3219 Set_Returns_By_Ref (Spec_Id);
3223 -- For a procedure, we add a return for all possible syntactic ends
3224 -- of the subprogram. Note that reanalysis is not necessary in this
3225 -- case since it would require a lot of work and accomplish nothing.
3227 if Ekind (Spec_Id) = E_Procedure
3228 or else Ekind (Spec_Id) = E_Generic_Procedure
3230 Add_Return (Statements (H));
3232 if Present (Exception_Handlers (H)) then
3233 Except_H := First_Non_Pragma (Exception_Handlers (H));
3235 while Present (Except_H) loop
3236 Add_Return (Statements (Except_H));
3237 Next_Non_Pragma (Except_H);
3241 -- For a function, we must deal with the case where there is at
3242 -- least one missing return. What we do is to wrap the entire body
3243 -- of the function in a block:
3256 -- raise Program_Error;
3259 -- This approach is necessary because the raise must be signalled
3260 -- to the caller, not handled by any local handler (RM 6.4(11)).
3262 -- Note: we do not need to analyze the constructed sequence here,
3263 -- since it has no handler, and an attempt to analyze the handled
3264 -- statement sequence twice is risky in various ways (e.g. the
3265 -- issue of expanding cleanup actions twice).
3267 elsif Has_Missing_Return (Spec_Id) then
3269 Hloc : constant Source_Ptr := Sloc (H);
3270 Blok : constant Node_Id :=
3271 Make_Block_Statement (Hloc,
3272 Handled_Statement_Sequence => H);
3273 Rais : constant Node_Id :=
3274 Make_Raise_Program_Error (Hloc,
3275 Reason => PE_Missing_Return);
3278 Set_Handled_Statement_Sequence (N,
3279 Make_Handled_Sequence_Of_Statements (Hloc,
3280 Statements => New_List (Blok, Rais)));
3282 New_Scope (Spec_Id);
3289 -- Add discriminal renamings to protected subprograms.
3290 -- Install new discriminals for expansion of the next
3291 -- subprogram of this protected type, if any.
3293 if Is_List_Member (N)
3294 and then Present (Parent (List_Containing (N)))
3295 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
3297 Add_Discriminal_Declarations
3298 (Declarations (N), Scop, Name_uObject, Loc);
3299 Add_Private_Declarations (Declarations (N), Scop, Name_uObject, Loc);
3301 -- Associate privals and discriminals with the next protected
3302 -- operation body to be expanded. These are used to expand
3303 -- references to private data objects and discriminants,
3306 Next_Op := Next_Protected_Operation (N);
3308 if Present (Next_Op) then
3309 Dec := Parent (Base_Type (Scop));
3310 Set_Privals (Dec, Next_Op, Loc);
3311 Set_Discriminals (Dec);
3315 -- If subprogram contains a parameterless recursive call, then we may
3316 -- have an infinite recursion, so see if we can generate code to check
3317 -- for this possibility if storage checks are not suppressed.
3319 if Ekind (Spec_Id) = E_Procedure
3320 and then Has_Recursive_Call (Spec_Id)
3321 and then not Storage_Checks_Suppressed (Spec_Id)
3323 Detect_Infinite_Recursion (N, Spec_Id);
3326 -- Finally, if we are in Normalize_Scalars mode, then any scalar out
3327 -- parameters must be initialized to the appropriate default value.
3329 if Ekind (Spec_Id) = E_Procedure and then Normalize_Scalars then
3336 Formal := First_Formal (Spec_Id);
3338 while Present (Formal) loop
3339 Floc := Sloc (Formal);
3341 if Ekind (Formal) = E_Out_Parameter
3342 and then Is_Scalar_Type (Etype (Formal))
3345 Make_Assignment_Statement (Floc,
3346 Name => New_Occurrence_Of (Formal, Floc),
3348 Get_Simple_Init_Val (Etype (Formal), Floc));
3349 Prepend (Stm, Declarations (N));
3353 Next_Formal (Formal);
3358 -- Deal with thread body
3360 if Is_Thread_Body (Spec_Id) then
3364 -- If the subprogram does not have pending instantiations, then we
3365 -- must generate the subprogram descriptor now, since the code for
3366 -- the subprogram is complete, and this is our last chance. However
3367 -- if there are pending instantiations, then the code is not
3368 -- complete, and we will delay the generation.
3370 if Is_Subprogram (Spec_Id)
3371 and then not Delay_Subprogram_Descriptors (Spec_Id)
3373 Generate_Subprogram_Descriptor_For_Subprogram (N, Spec_Id);
3376 -- Set to encode entity names in package body before gigi is called
3378 Qualify_Entity_Names (N);
3379 end Expand_N_Subprogram_Body;
3381 -----------------------------------
3382 -- Expand_N_Subprogram_Body_Stub --
3383 -----------------------------------
3385 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
3387 if Present (Corresponding_Body (N)) then
3388 Expand_N_Subprogram_Body (
3389 Unit_Declaration_Node (Corresponding_Body (N)));
3391 end Expand_N_Subprogram_Body_Stub;
3393 -------------------------------------
3394 -- Expand_N_Subprogram_Declaration --
3395 -------------------------------------
3397 -- If the declaration appears within a protected body, it is a private
3398 -- operation of the protected type. We must create the corresponding
3399 -- protected subprogram an associated formals. For a normal protected
3400 -- operation, this is done when expanding the protected type declaration.
3402 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
3403 Loc : constant Source_Ptr := Sloc (N);
3404 Subp : constant Entity_Id := Defining_Entity (N);
3405 Scop : constant Entity_Id := Scope (Subp);
3406 Prot_Decl : Node_Id;
3408 Prot_Id : Entity_Id;
3411 -- Deal with case of protected subprogram
3413 if Is_List_Member (N)
3414 and then Present (Parent (List_Containing (N)))
3415 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
3416 and then Is_Protected_Type (Scop)
3418 if No (Protected_Body_Subprogram (Subp)) then
3420 Make_Subprogram_Declaration (Loc,
3422 Build_Protected_Sub_Specification
3423 (N, Scop, Unprotected => True));
3425 -- The protected subprogram is declared outside of the protected
3426 -- body. Given that the body has frozen all entities so far, we
3427 -- analyze the subprogram and perform freezing actions explicitly.
3428 -- If the body is a subunit, the insertion point is before the
3429 -- stub in the parent.
3431 Prot_Bod := Parent (List_Containing (N));
3433 if Nkind (Parent (Prot_Bod)) = N_Subunit then
3434 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
3437 Insert_Before (Prot_Bod, Prot_Decl);
3438 Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
3440 New_Scope (Scope (Scop));
3441 Analyze (Prot_Decl);
3442 Create_Extra_Formals (Prot_Id);
3443 Set_Protected_Body_Subprogram (Subp, Prot_Id);
3447 end Expand_N_Subprogram_Declaration;
3449 ---------------------------------------
3450 -- Expand_Protected_Object_Reference --
3451 ---------------------------------------
3453 function Expand_Protected_Object_Reference
3458 Loc : constant Source_Ptr := Sloc (N);
3465 Rec := Make_Identifier (Loc, Name_uObject);
3466 Set_Etype (Rec, Corresponding_Record_Type (Scop));
3468 -- Find enclosing protected operation, and retrieve its first
3469 -- parameter, which denotes the enclosing protected object.
3470 -- If the enclosing operation is an entry, we are immediately
3471 -- within the protected body, and we can retrieve the object
3472 -- from the service entries procedure. A barrier function has
3473 -- has the same signature as an entry. A barrier function is
3474 -- compiled within the protected object, but unlike protected
3475 -- operations its never needs locks, so that its protected body
3476 -- subprogram points to itself.
3478 Proc := Current_Scope;
3480 while Present (Proc)
3481 and then Scope (Proc) /= Scop
3483 Proc := Scope (Proc);
3486 Corr := Protected_Body_Subprogram (Proc);
3490 -- Previous error left expansion incomplete.
3491 -- Nothing to do on this call.
3498 (First (Parameter_Specifications (Parent (Corr))));
3500 if Is_Subprogram (Proc)
3501 and then Proc /= Corr
3503 -- Protected function or procedure.
3505 Set_Entity (Rec, Param);
3507 -- Rec is a reference to an entity which will not be in scope
3508 -- when the call is reanalyzed, and needs no further analysis.
3513 -- Entry or barrier function for entry body.
3514 -- The first parameter of the entry body procedure is a
3515 -- pointer to the object. We create a local variable
3516 -- of the proper type, duplicating what is done to define
3517 -- _object later on.
3521 Obj_Ptr : constant Entity_Id := Make_Defining_Identifier (Loc,
3523 New_Internal_Name ('T'));
3527 Make_Full_Type_Declaration (Loc,
3528 Defining_Identifier => Obj_Ptr,
3530 Make_Access_To_Object_Definition (Loc,
3531 Subtype_Indication =>
3533 (Corresponding_Record_Type (Scop), Loc))));
3535 Insert_Actions (N, Decls);
3536 Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
3539 Make_Explicit_Dereference (Loc,
3540 Unchecked_Convert_To (Obj_Ptr,
3541 New_Occurrence_Of (Param, Loc)));
3543 -- Analyze new actual. Other actuals in calls are already
3544 -- analyzed and the list of actuals is not renalyzed after
3547 Set_Parent (Rec, N);
3553 end Expand_Protected_Object_Reference;
3555 --------------------------------------
3556 -- Expand_Protected_Subprogram_Call --
3557 --------------------------------------
3559 procedure Expand_Protected_Subprogram_Call
3567 -- If the protected object is not an enclosing scope, this is
3568 -- an inter-object function call. Inter-object procedure
3569 -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
3570 -- The call is intra-object only if the subprogram being
3571 -- called is in the protected body being compiled, and if the
3572 -- protected object in the call is statically the enclosing type.
3573 -- The object may be an component of some other data structure,
3574 -- in which case this must be handled as an inter-object call.
3576 if not In_Open_Scopes (Scop)
3577 or else not Is_Entity_Name (Name (N))
3579 if Nkind (Name (N)) = N_Selected_Component then
3580 Rec := Prefix (Name (N));
3583 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
3584 Rec := Prefix (Prefix (Name (N)));
3587 Build_Protected_Subprogram_Call (N,
3588 Name => New_Occurrence_Of (Subp, Sloc (N)),
3589 Rec => Convert_Concurrent (Rec, Etype (Rec)),
3593 Rec := Expand_Protected_Object_Reference (N, Scop);
3599 Build_Protected_Subprogram_Call (N,
3608 -- If it is a function call it can appear in elaboration code and
3609 -- the called entity must be frozen here.
3611 if Ekind (Subp) = E_Function then
3612 Freeze_Expression (Name (N));
3614 end Expand_Protected_Subprogram_Call;
3616 -----------------------
3617 -- Freeze_Subprogram --
3618 -----------------------
3620 procedure Freeze_Subprogram (N : Node_Id) is
3621 E : constant Entity_Id := Entity (N);
3624 -- When a primitive is frozen, enter its name in the corresponding
3625 -- dispatch table. If the DTC_Entity field is not set this is an
3626 -- overridden primitive that can be ignored. We suppress the
3627 -- initialization of the dispatch table entry when Java_VM because
3628 -- the dispatching mechanism is handled internally by the JVM.
3630 if Is_Dispatching_Operation (E)
3631 and then not Is_Abstract (E)
3632 and then Present (DTC_Entity (E))
3633 and then not Is_CPP_Class (Scope (DTC_Entity (E)))
3634 and then not Java_VM
3636 Check_Overriding_Operation (E);
3637 Insert_After (N, Fill_DT_Entry (Sloc (N), E));
3640 -- Mark functions that return by reference. Note that it cannot be
3641 -- part of the normal semantic analysis of the spec since the
3642 -- underlying returned type may not be known yet (for private types)
3645 Typ : constant Entity_Id := Etype (E);
3646 Utyp : constant Entity_Id := Underlying_Type (Typ);
3649 if Is_Return_By_Reference_Type (Typ) then
3650 Set_Returns_By_Ref (E);
3652 elsif Present (Utyp) and then Controlled_Type (Utyp) then
3653 Set_Returns_By_Ref (E);
3656 end Freeze_Subprogram;
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