1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2004, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Errout; use Errout;
32 with Elists; use Elists;
33 with Exp_Ch2; use Exp_Ch2;
34 with Exp_Ch3; use Exp_Ch3;
35 with Exp_Ch7; use Exp_Ch7;
36 with Exp_Ch9; use Exp_Ch9;
37 with Exp_Ch11; use Exp_Ch11;
38 with Exp_Dbug; use Exp_Dbug;
39 with Exp_Disp; use Exp_Disp;
40 with Exp_Dist; use Exp_Dist;
41 with Exp_Intr; use Exp_Intr;
42 with Exp_Pakd; use Exp_Pakd;
43 with Exp_Tss; use Exp_Tss;
44 with Exp_Util; use Exp_Util;
45 with Fname; use Fname;
46 with Freeze; use Freeze;
47 with Hostparm; use Hostparm;
48 with Inline; use Inline;
50 with Nlists; use Nlists;
51 with Nmake; use Nmake;
53 with Restrict; use Restrict;
54 with Rident; use Rident;
55 with Rtsfind; use Rtsfind;
57 with Sem_Ch6; use Sem_Ch6;
58 with Sem_Ch8; use Sem_Ch8;
59 with Sem_Ch12; use Sem_Ch12;
60 with Sem_Ch13; use Sem_Ch13;
61 with Sem_Disp; use Sem_Disp;
62 with Sem_Dist; use Sem_Dist;
63 with Sem_Res; use Sem_Res;
64 with Sem_Util; use Sem_Util;
65 with Sinfo; use Sinfo;
66 with Snames; use Snames;
67 with Stand; use Stand;
68 with Tbuild; use Tbuild;
69 with Ttypes; use Ttypes;
70 with Uintp; use Uintp;
71 with Validsw; use Validsw;
73 package body Exp_Ch6 is
75 -----------------------
76 -- Local Subprograms --
77 -----------------------
79 procedure Check_Overriding_Operation (Subp : Entity_Id);
80 -- Subp is a dispatching operation. Check whether it may override an
81 -- inherited private operation, in which case its DT entry is that of
82 -- the hidden operation, not the one it may have received earlier.
83 -- This must be done before emitting the code to set the corresponding
84 -- DT to the address of the subprogram. The actual placement of Subp in
85 -- the proper place in the list of primitive operations is done in
86 -- Declare_Inherited_Private_Subprograms, which also has to deal with
87 -- implicit operations. This duplication is unavoidable for now???
89 procedure Detect_Infinite_Recursion (N : Node_Id; Spec : Entity_Id);
90 -- This procedure is called only if the subprogram body N, whose spec
91 -- has the given entity Spec, contains a parameterless recursive call.
92 -- It attempts to generate runtime code to detect if this a case of
93 -- infinite recursion.
95 -- The body is scanned to determine dependencies. If the only external
96 -- dependencies are on a small set of scalar variables, then the values
97 -- of these variables are captured on entry to the subprogram, and if
98 -- the values are not changed for the call, we know immediately that
99 -- we have an infinite recursion.
101 procedure Expand_Actuals (N : Node_Id; Subp : Entity_Id);
102 -- For each actual of an in-out parameter which is a numeric conversion
103 -- of the form T(A), where A denotes a variable, we insert the declaration:
105 -- Temp : T := T (A);
107 -- prior to the call. Then we replace the actual with a reference to Temp,
108 -- and append the assignment:
110 -- A := TypeA (Temp);
112 -- after the call. Here TypeA is the actual type of variable A.
113 -- For out parameters, the initial declaration has no expression.
114 -- If A is not an entity name, we generate instead:
116 -- Var : TypeA renames A;
117 -- Temp : T := Var; -- omitting expression for out parameter.
119 -- Var := TypeA (Temp);
121 -- For other in-out parameters, we emit the required constraint checks
122 -- before and/or after the call.
124 -- For all parameter modes, actuals that denote components and slices
125 -- of packed arrays are expanded into suitable temporaries.
127 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 Restriction_Active (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));
600 elsif Ekind (Formal) = E_In_Parameter then
601 Init := New_Occurrence_Of (Var, Loc);
608 Make_Object_Declaration (Loc,
609 Defining_Identifier => Temp,
611 New_Occurrence_Of (Etype (Formal), Loc),
613 Set_Assignment_OK (N_Node);
614 Insert_Action (N, N_Node);
616 -- Now, normally the deal here is that we use the defining
617 -- identifier created by that object declaration. There is
618 -- one exception to this. In the change of representation case
619 -- the above declaration will end up looking like:
621 -- temp : type := identifier;
623 -- And in this case we might as well use the identifier directly
624 -- and eliminate the temporary. Note that the analysis of the
625 -- declaration was not a waste of time in that case, since it is
626 -- what generated the necessary change of representation code. If
627 -- the change of representation introduced additional code, as in
628 -- a fixed-integer conversion, the expression is not an identifier
632 and then Present (Expression (N_Node))
633 and then Is_Entity_Name (Expression (N_Node))
635 Temp := Entity (Expression (N_Node));
636 Rewrite (N_Node, Make_Null_Statement (Loc));
639 -- For IN parameter, all we do is to replace the actual
641 if Ekind (Formal) = E_In_Parameter then
642 Rewrite (Actual, New_Reference_To (Temp, Loc));
645 -- Processing for OUT or IN OUT parameter
648 -- If type conversion, use reverse conversion on exit
650 if Nkind (Actual) = N_Type_Conversion then
651 if Conversion_OK (Actual) then
652 Expr := OK_Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
654 Expr := Convert_To (V_Typ, New_Occurrence_Of (Temp, Loc));
657 Expr := New_Occurrence_Of (Temp, Loc);
660 Rewrite (Actual, New_Reference_To (Temp, Loc));
663 Append_To (Post_Call,
664 Make_Assignment_Statement (Loc,
665 Name => New_Occurrence_Of (Var, Loc),
666 Expression => Expr));
668 Set_Assignment_OK (Name (Last (Post_Call)));
670 end Add_Call_By_Copy_Code;
672 ----------------------------------
673 -- Add_Packed_Call_By_Copy_Code --
674 ----------------------------------
676 procedure Add_Packed_Call_By_Copy_Code is
686 -- Prepare to generate code
688 Temp := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
689 Incod := Relocate_Node (Actual);
690 Outcod := New_Copy_Tree (Incod);
692 -- Generate declaration of temporary variable, initializing it
693 -- with the input parameter unless we have an OUT variable.
695 if Ekind (Formal) = E_Out_Parameter then
700 Make_Object_Declaration (Loc,
701 Defining_Identifier => Temp,
703 New_Occurrence_Of (Etype (Formal), Loc),
704 Expression => Incod));
706 -- The actual is simply a reference to the temporary
708 Rewrite (Actual, New_Occurrence_Of (Temp, Loc));
710 -- Generate copy out if OUT or IN OUT parameter
712 if Ekind (Formal) /= E_In_Parameter then
714 Rhs := New_Occurrence_Of (Temp, Loc);
716 -- Deal with conversion
718 if Nkind (Lhs) = N_Type_Conversion then
719 Lhs := Expression (Lhs);
720 Rhs := Convert_To (Etype (Actual), Rhs);
723 Append_To (Post_Call,
724 Make_Assignment_Statement (Loc,
728 end Add_Packed_Call_By_Copy_Code;
730 ---------------------------
731 -- Check_Fortran_Logical --
732 ---------------------------
734 procedure Check_Fortran_Logical is
735 Logical : constant Entity_Id := Etype (Formal);
738 -- Note: this is very incomplete, e.g. it does not handle arrays
739 -- of logical values. This is really not the right approach at all???)
742 if Convention (Subp) = Convention_Fortran
743 and then Root_Type (Etype (Formal)) = Standard_Boolean
744 and then Ekind (Formal) /= E_In_Parameter
746 Var := Make_Var (Actual);
747 Append_To (Post_Call,
748 Make_Assignment_Statement (Loc,
749 Name => New_Occurrence_Of (Var, Loc),
751 Unchecked_Convert_To (
754 Left_Opnd => New_Occurrence_Of (Var, Loc),
756 Unchecked_Convert_To (
758 New_Occurrence_Of (Standard_False, Loc))))));
760 end Check_Fortran_Logical;
766 function Make_Var (Actual : Node_Id) return Entity_Id is
770 if Is_Entity_Name (Actual) then
771 return Entity (Actual);
774 Var := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
777 Make_Object_Renaming_Declaration (Loc,
778 Defining_Identifier => Var,
780 New_Occurrence_Of (Etype (Actual), Loc),
781 Name => Relocate_Node (Actual));
783 Insert_Action (N, N_Node);
788 -------------------------
789 -- Reset_Packed_Prefix --
790 -------------------------
792 procedure Reset_Packed_Prefix is
793 Pfx : Node_Id := Actual;
797 Set_Analyzed (Pfx, False);
798 exit when Nkind (Pfx) /= N_Selected_Component
799 and then Nkind (Pfx) /= N_Indexed_Component;
802 end Reset_Packed_Prefix;
804 -- Start of processing for Expand_Actuals
807 Formal := First_Formal (Subp);
808 Actual := First_Actual (N);
810 Post_Call := New_List;
812 while Present (Formal) loop
813 E_Formal := Etype (Formal);
815 if Is_Scalar_Type (E_Formal)
816 or else Nkind (Actual) = N_Slice
818 Check_Fortran_Logical;
822 elsif Ekind (Formal) /= E_Out_Parameter then
824 -- The unusual case of the current instance of a protected type
825 -- requires special handling. This can only occur in the context
826 -- of a call within the body of a protected operation.
828 if Is_Entity_Name (Actual)
829 and then Ekind (Entity (Actual)) = E_Protected_Type
830 and then In_Open_Scopes (Entity (Actual))
832 if Scope (Subp) /= Entity (Actual) then
833 Error_Msg_N ("operation outside protected type may not "
834 & "call back its protected operations?", Actual);
838 Expand_Protected_Object_Reference (N, Entity (Actual)));
841 Apply_Constraint_Check (Actual, E_Formal);
843 -- Out parameter case. No constraint checks on access type
846 elsif Is_Access_Type (E_Formal) then
851 elsif Has_Discriminants (Base_Type (E_Formal))
852 or else Has_Non_Null_Base_Init_Proc (E_Formal)
854 Apply_Constraint_Check (Actual, E_Formal);
859 Apply_Constraint_Check (Actual, Base_Type (E_Formal));
862 -- Processing for IN-OUT and OUT parameters
864 if Ekind (Formal) /= E_In_Parameter then
866 -- For type conversions of arrays, apply length/range checks
868 if Is_Array_Type (E_Formal)
869 and then Nkind (Actual) = N_Type_Conversion
871 if Is_Constrained (E_Formal) then
872 Apply_Length_Check (Expression (Actual), E_Formal);
874 Apply_Range_Check (Expression (Actual), E_Formal);
878 -- If argument is a type conversion for a type that is passed
879 -- by copy, then we must pass the parameter by copy.
881 if Nkind (Actual) = N_Type_Conversion
883 (Is_Numeric_Type (E_Formal)
884 or else Is_Access_Type (E_Formal)
885 or else Is_Enumeration_Type (E_Formal)
886 or else Is_Bit_Packed_Array (Etype (Formal))
887 or else Is_Bit_Packed_Array (Etype (Expression (Actual)))
889 -- Also pass by copy if change of representation
891 or else not Same_Representation
893 Etype (Expression (Actual))))
895 Add_Call_By_Copy_Code;
897 -- References to components of bit packed arrays are expanded
898 -- at this point, rather than at the point of analysis of the
899 -- actuals, to handle the expansion of the assignment to
900 -- [in] out parameters.
902 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
903 Add_Packed_Call_By_Copy_Code;
905 -- References to slices of bit packed arrays are expanded
907 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
908 Add_Call_By_Copy_Code;
910 -- References to possibly unaligned slices of arrays are expanded
912 elsif Is_Possibly_Unaligned_Slice (Actual) then
913 Add_Call_By_Copy_Code;
915 -- Deal with access types where the actual subtpe and the
916 -- formal subtype are not the same, requiring a check.
918 -- It is necessary to exclude tagged types because of "downward
919 -- conversion" errors and a strange assertion error in namet
920 -- from gnatf in bug 1215-001 ???
922 elsif Is_Access_Type (E_Formal)
923 and then not Same_Type (E_Formal, Etype (Actual))
924 and then not Is_Tagged_Type (Designated_Type (E_Formal))
926 Add_Call_By_Copy_Code;
928 elsif Is_Entity_Name (Actual)
929 and then Treat_As_Volatile (Entity (Actual))
930 and then not Is_Scalar_Type (Etype (Entity (Actual)))
931 and then not Treat_As_Volatile (E_Formal)
933 Add_Call_By_Copy_Code;
935 elsif Nkind (Actual) = N_Indexed_Component
936 and then Is_Entity_Name (Prefix (Actual))
937 and then Has_Volatile_Components (Entity (Prefix (Actual)))
939 Add_Call_By_Copy_Code;
942 -- Processing for IN parameters
945 -- For IN parameters is in the packed array case, we expand an
946 -- indexed component (the circuit in Exp_Ch4 deliberately left
947 -- indexed components appearing as actuals untouched, so that
948 -- the special processing above for the OUT and IN OUT cases
949 -- could be performed. We could make the test in Exp_Ch4 more
950 -- complex and have it detect the parameter mode, but it is
951 -- easier simply to handle all cases here.
953 if Nkind (Actual) = N_Indexed_Component
954 and then Is_Packed (Etype (Prefix (Actual)))
957 Expand_Packed_Element_Reference (Actual);
959 -- If we have a reference to a bit packed array, we copy it,
960 -- since the actual must be byte aligned.
962 -- Is this really necessary in all cases???
964 elsif Is_Ref_To_Bit_Packed_Array (Actual) then
965 Add_Packed_Call_By_Copy_Code;
967 -- Similarly, we have to expand slices of packed arrays here
968 -- because the result must be byte aligned.
970 elsif Is_Ref_To_Bit_Packed_Slice (Actual) then
971 Add_Call_By_Copy_Code;
973 -- Only processing remaining is to pass by copy if this is a
974 -- reference to a possibly unaligned slice, since the caller
975 -- expects an appropriately aligned argument.
977 elsif Is_Possibly_Unaligned_Slice (Actual) then
978 Add_Call_By_Copy_Code;
982 Next_Formal (Formal);
983 Next_Actual (Actual);
986 -- Find right place to put post call stuff if it is present
988 if not Is_Empty_List (Post_Call) then
990 -- If call is not a list member, it must be the triggering
991 -- statement of a triggering alternative or an entry call
992 -- alternative, and we can add the post call stuff to the
993 -- corresponding statement list.
995 if not Is_List_Member (N) then
997 P : constant Node_Id := Parent (N);
1000 pragma Assert (Nkind (P) = N_Triggering_Alternative
1001 or else Nkind (P) = N_Entry_Call_Alternative);
1003 if Is_Non_Empty_List (Statements (P)) then
1004 Insert_List_Before_And_Analyze
1005 (First (Statements (P)), Post_Call);
1007 Set_Statements (P, Post_Call);
1011 -- Otherwise, normal case where N is in a statement sequence,
1012 -- just put the post-call stuff after the call statement.
1015 Insert_Actions_After (N, Post_Call);
1019 -- The call node itself is re-analyzed in Expand_Call.
1027 -- This procedure handles expansion of function calls and procedure call
1028 -- statements (i.e. it serves as the body for Expand_N_Function_Call and
1029 -- Expand_N_Procedure_Call_Statement. Processing for calls includes:
1031 -- Replace call to Raise_Exception by Raise_Exception always if possible
1032 -- Provide values of actuals for all formals in Extra_Formals list
1033 -- Replace "call" to enumeration literal function by literal itself
1034 -- Rewrite call to predefined operator as operator
1035 -- Replace actuals to in-out parameters that are numeric conversions,
1036 -- with explicit assignment to temporaries before and after the call.
1037 -- Remove optional actuals if First_Optional_Parameter specified.
1039 -- Note that the list of actuals has been filled with default expressions
1040 -- during semantic analysis of the call. Only the extra actuals required
1041 -- for the 'Constrained attribute and for accessibility checks are added
1044 procedure Expand_Call (N : Node_Id) is
1045 Loc : constant Source_Ptr := Sloc (N);
1046 Remote : constant Boolean := Is_Remote_Call (N);
1048 Orig_Subp : Entity_Id := Empty;
1049 Parent_Subp : Entity_Id;
1050 Parent_Formal : Entity_Id;
1053 Prev : Node_Id := Empty;
1054 Prev_Orig : Node_Id;
1056 Extra_Actuals : List_Id := No_List;
1059 procedure Add_Actual_Parameter (Insert_Param : Node_Id);
1060 -- Adds one entry to the end of the actual parameter list. Used for
1061 -- default parameters and for extra actuals (for Extra_Formals).
1062 -- The argument is an N_Parameter_Association node.
1064 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id);
1065 -- Adds an extra actual to the list of extra actuals. Expr
1066 -- is the expression for the value of the actual, EF is the
1067 -- entity for the extra formal.
1069 function Inherited_From_Formal (S : Entity_Id) return Entity_Id;
1070 -- Within an instance, a type derived from a non-tagged formal derived
1071 -- type inherits from the original parent, not from the actual. This is
1072 -- tested in 4723-003. The current derivation mechanism has the derived
1073 -- type inherit from the actual, which is only correct outside of the
1074 -- instance. If the subprogram is inherited, we test for this particular
1075 -- case through a convoluted tree traversal before setting the proper
1076 -- subprogram to be called.
1078 --------------------------
1079 -- Add_Actual_Parameter --
1080 --------------------------
1082 procedure Add_Actual_Parameter (Insert_Param : Node_Id) is
1083 Actual_Expr : constant Node_Id :=
1084 Explicit_Actual_Parameter (Insert_Param);
1087 -- Case of insertion is first named actual
1089 if No (Prev) or else
1090 Nkind (Parent (Prev)) /= N_Parameter_Association
1092 Set_Next_Named_Actual (Insert_Param, First_Named_Actual (N));
1093 Set_First_Named_Actual (N, Actual_Expr);
1096 if not Present (Parameter_Associations (N)) then
1097 Set_Parameter_Associations (N, New_List);
1098 Append (Insert_Param, Parameter_Associations (N));
1101 Insert_After (Prev, Insert_Param);
1104 -- Case of insertion is not first named actual
1107 Set_Next_Named_Actual
1108 (Insert_Param, Next_Named_Actual (Parent (Prev)));
1109 Set_Next_Named_Actual (Parent (Prev), Actual_Expr);
1110 Append (Insert_Param, Parameter_Associations (N));
1113 Prev := Actual_Expr;
1114 end Add_Actual_Parameter;
1116 ----------------------
1117 -- Add_Extra_Actual --
1118 ----------------------
1120 procedure Add_Extra_Actual (Expr : Node_Id; EF : Entity_Id) is
1121 Loc : constant Source_Ptr := Sloc (Expr);
1124 if Extra_Actuals = No_List then
1125 Extra_Actuals := New_List;
1126 Set_Parent (Extra_Actuals, N);
1129 Append_To (Extra_Actuals,
1130 Make_Parameter_Association (Loc,
1131 Explicit_Actual_Parameter => Expr,
1133 Make_Identifier (Loc, Chars (EF))));
1135 Analyze_And_Resolve (Expr, Etype (EF));
1136 end Add_Extra_Actual;
1138 ---------------------------
1139 -- Inherited_From_Formal --
1140 ---------------------------
1142 function Inherited_From_Formal (S : Entity_Id) return Entity_Id is
1144 Gen_Par : Entity_Id;
1145 Gen_Prim : Elist_Id;
1150 -- If the operation is inherited, it is attached to the corresponding
1151 -- type derivation. If the parent in the derivation is a generic
1152 -- actual, it is a subtype of the actual, and we have to recover the
1153 -- original derived type declaration to find the proper parent.
1155 if Nkind (Parent (S)) /= N_Full_Type_Declaration
1156 or else not Is_Derived_Type (Defining_Identifier (Parent (S)))
1157 or else Nkind (Type_Definition (Original_Node (Parent (S))))
1158 /= N_Derived_Type_Definition
1159 or else not In_Instance
1166 (Type_Definition (Original_Node (Parent (S)))));
1168 if Nkind (Indic) = N_Subtype_Indication then
1169 Par := Entity (Subtype_Mark (Indic));
1171 Par := Entity (Indic);
1175 if not Is_Generic_Actual_Type (Par)
1176 or else Is_Tagged_Type (Par)
1177 or else Nkind (Parent (Par)) /= N_Subtype_Declaration
1178 or else not In_Open_Scopes (Scope (Par))
1183 Gen_Par := Generic_Parent_Type (Parent (Par));
1186 -- If the generic parent type is still the generic type, this
1187 -- is a private formal, not a derived formal, and there are no
1188 -- operations inherited from the formal.
1190 if Nkind (Parent (Gen_Par)) = N_Formal_Type_Declaration then
1194 Gen_Prim := Collect_Primitive_Operations (Gen_Par);
1195 Elmt := First_Elmt (Gen_Prim);
1197 while Present (Elmt) loop
1198 if Chars (Node (Elmt)) = Chars (S) then
1204 F1 := First_Formal (S);
1205 F2 := First_Formal (Node (Elmt));
1208 and then Present (F2)
1211 if Etype (F1) = Etype (F2)
1212 or else Etype (F2) = Gen_Par
1218 exit; -- not the right subprogram
1230 raise Program_Error;
1231 end Inherited_From_Formal;
1233 -- Start of processing for Expand_Call
1236 -- Ignore if previous error
1238 if Nkind (N) in N_Has_Etype and then Etype (N) = Any_Type then
1242 -- Call using access to subprogram with explicit dereference
1244 if Nkind (Name (N)) = N_Explicit_Dereference then
1245 Subp := Etype (Name (N));
1246 Parent_Subp := Empty;
1248 -- Case of call to simple entry, where the Name is a selected component
1249 -- whose prefix is the task, and whose selector name is the entry name
1251 elsif Nkind (Name (N)) = N_Selected_Component then
1252 Subp := Entity (Selector_Name (Name (N)));
1253 Parent_Subp := Empty;
1255 -- Case of call to member of entry family, where Name is an indexed
1256 -- component, with the prefix being a selected component giving the
1257 -- task and entry family name, and the index being the entry index.
1259 elsif Nkind (Name (N)) = N_Indexed_Component then
1260 Subp := Entity (Selector_Name (Prefix (Name (N))));
1261 Parent_Subp := Empty;
1266 Subp := Entity (Name (N));
1267 Parent_Subp := Alias (Subp);
1269 -- Replace call to Raise_Exception by call to Raise_Exception_Always
1270 -- if we can tell that the first parameter cannot possibly be null.
1271 -- This helps optimization and also generation of warnings.
1273 if not Restriction_Active (No_Exception_Handlers)
1274 and then Is_RTE (Subp, RE_Raise_Exception)
1277 FA : constant Node_Id := Original_Node (First_Actual (N));
1280 -- The case we catch is where the first argument is obtained
1281 -- using the Identity attribute (which must always be non-null)
1283 if Nkind (FA) = N_Attribute_Reference
1284 and then Attribute_Name (FA) = Name_Identity
1286 Subp := RTE (RE_Raise_Exception_Always);
1287 Set_Entity (Name (N), Subp);
1292 if Ekind (Subp) = E_Entry then
1293 Parent_Subp := Empty;
1297 -- First step, compute extra actuals, corresponding to any
1298 -- Extra_Formals present. Note that we do not access Extra_Formals
1299 -- directly, instead we simply note the presence of the extra
1300 -- formals as we process the regular formals and collect the
1301 -- corresponding actuals in Extra_Actuals.
1303 -- We also generate any required range checks for actuals as we go
1304 -- through the loop, since this is a convenient place to do this.
1306 Formal := First_Formal (Subp);
1307 Actual := First_Actual (N);
1308 while Present (Formal) loop
1310 -- Generate range check if required (not activated yet ???)
1312 -- if Do_Range_Check (Actual) then
1313 -- Set_Do_Range_Check (Actual, False);
1314 -- Generate_Range_Check
1315 -- (Actual, Etype (Formal), CE_Range_Check_Failed);
1318 -- Prepare to examine current entry
1321 Prev_Orig := Original_Node (Prev);
1323 -- Create possible extra actual for constrained case. Usually,
1324 -- the extra actual is of the form actual'constrained, but since
1325 -- this attribute is only available for unconstrained records,
1326 -- TRUE is expanded if the type of the formal happens to be
1327 -- constrained (for instance when this procedure is inherited
1328 -- from an unconstrained record to a constrained one) or if the
1329 -- actual has no discriminant (its type is constrained). An
1330 -- exception to this is the case of a private type without
1331 -- discriminants. In this case we pass FALSE because the
1332 -- object has underlying discriminants with defaults.
1334 if Present (Extra_Constrained (Formal)) then
1335 if Ekind (Etype (Prev)) in Private_Kind
1336 and then not Has_Discriminants (Base_Type (Etype (Prev)))
1339 New_Occurrence_Of (Standard_False, Loc),
1340 Extra_Constrained (Formal));
1342 elsif Is_Constrained (Etype (Formal))
1343 or else not Has_Discriminants (Etype (Prev))
1346 New_Occurrence_Of (Standard_True, Loc),
1347 Extra_Constrained (Formal));
1350 -- If the actual is a type conversion, then the constrained
1351 -- test applies to the actual, not the target type.
1354 Act_Prev : Node_Id := Prev;
1357 -- Test for unchecked conversions as well, which can
1358 -- occur as out parameter actuals on calls to stream
1361 while Nkind (Act_Prev) = N_Type_Conversion
1362 or else Nkind (Act_Prev) = N_Unchecked_Type_Conversion
1364 Act_Prev := Expression (Act_Prev);
1368 Make_Attribute_Reference (Sloc (Prev),
1370 Duplicate_Subexpr_No_Checks
1371 (Act_Prev, Name_Req => True),
1372 Attribute_Name => Name_Constrained),
1373 Extra_Constrained (Formal));
1378 -- Create possible extra actual for accessibility level
1380 if Present (Extra_Accessibility (Formal)) then
1381 if Is_Entity_Name (Prev_Orig) then
1383 -- When passing an access parameter as the actual to another
1384 -- access parameter we need to pass along the actual's own
1385 -- associated access level parameter. This is done is we are
1386 -- in the scope of the formal access parameter (if this is an
1387 -- inlined body the extra formal is irrelevant).
1389 if Ekind (Entity (Prev_Orig)) in Formal_Kind
1390 and then Ekind (Etype (Prev_Orig)) = E_Anonymous_Access_Type
1391 and then In_Open_Scopes (Scope (Entity (Prev_Orig)))
1394 Parm_Ent : constant Entity_Id := Param_Entity (Prev_Orig);
1397 pragma Assert (Present (Parm_Ent));
1399 if Present (Extra_Accessibility (Parm_Ent)) then
1402 (Extra_Accessibility (Parm_Ent), Loc),
1403 Extra_Accessibility (Formal));
1405 -- If the actual access parameter does not have an
1406 -- associated extra formal providing its scope level,
1407 -- then treat the actual as having library-level
1412 Make_Integer_Literal (Loc,
1413 Intval => Scope_Depth (Standard_Standard)),
1414 Extra_Accessibility (Formal));
1418 -- The actual is a normal access value, so just pass the
1419 -- level of the actual's access type.
1423 Make_Integer_Literal (Loc,
1424 Intval => Type_Access_Level (Etype (Prev_Orig))),
1425 Extra_Accessibility (Formal));
1429 case Nkind (Prev_Orig) is
1431 when N_Attribute_Reference =>
1433 case Get_Attribute_Id (Attribute_Name (Prev_Orig)) is
1435 -- For X'Access, pass on the level of the prefix X
1437 when Attribute_Access =>
1439 Make_Integer_Literal (Loc,
1441 Object_Access_Level (Prefix (Prev_Orig))),
1442 Extra_Accessibility (Formal));
1444 -- Treat the unchecked attributes as library-level
1446 when Attribute_Unchecked_Access |
1447 Attribute_Unrestricted_Access =>
1449 Make_Integer_Literal (Loc,
1450 Intval => Scope_Depth (Standard_Standard)),
1451 Extra_Accessibility (Formal));
1453 -- No other cases of attributes returning access
1454 -- values that can be passed to access parameters
1457 raise Program_Error;
1461 -- For allocators we pass the level of the execution of
1462 -- the called subprogram, which is one greater than the
1463 -- current scope level.
1467 Make_Integer_Literal (Loc,
1468 Scope_Depth (Current_Scope) + 1),
1469 Extra_Accessibility (Formal));
1471 -- For other cases we simply pass the level of the
1472 -- actual's access type.
1476 Make_Integer_Literal (Loc,
1477 Intval => Type_Access_Level (Etype (Prev_Orig))),
1478 Extra_Accessibility (Formal));
1484 -- Perform the check of 4.6(49) that prevents a null value
1485 -- from being passed as an actual to an access parameter.
1486 -- Note that the check is elided in the common cases of
1487 -- passing an access attribute or access parameter as an
1488 -- actual. Also, we currently don't enforce this check for
1489 -- expander-generated actuals and when -gnatdj is set.
1491 if Ekind (Etype (Formal)) /= E_Anonymous_Access_Type
1492 or else Access_Checks_Suppressed (Subp)
1496 elsif Debug_Flag_J then
1499 elsif not Comes_From_Source (Prev) then
1502 elsif Is_Entity_Name (Prev)
1503 and then Ekind (Etype (Prev)) = E_Anonymous_Access_Type
1507 elsif Nkind (Prev) = N_Allocator
1508 or else Nkind (Prev) = N_Attribute_Reference
1512 -- Suppress null checks when passing to access parameters
1513 -- of Java subprograms. (Should this be done for other
1514 -- foreign conventions as well ???)
1516 elsif Convention (Subp) = Convention_Java then
1522 Left_Opnd => Duplicate_Subexpr_No_Checks (Prev),
1523 Right_Opnd => Make_Null (Loc));
1524 Insert_Action (Prev,
1525 Make_Raise_Constraint_Error (Loc,
1527 Reason => CE_Access_Parameter_Is_Null));
1530 -- Perform appropriate validity checks on parameters that
1533 if Validity_Checks_On then
1534 if Ekind (Formal) = E_In_Parameter
1535 and then Validity_Check_In_Params
1537 -- If the actual is an indexed component of a packed
1538 -- type, it has not been expanded yet. It will be
1539 -- copied in the validity code that follows, and has
1540 -- to be expanded appropriately, so reanalyze it.
1542 if Nkind (Actual) = N_Indexed_Component then
1543 Set_Analyzed (Actual, False);
1546 Ensure_Valid (Actual);
1548 elsif Ekind (Formal) = E_In_Out_Parameter
1549 and then Validity_Check_In_Out_Params
1551 Ensure_Valid (Actual);
1555 -- For IN OUT and OUT parameters, ensure that subscripts are valid
1556 -- since this is a left side reference. We only do this for calls
1557 -- from the source program since we assume that compiler generated
1558 -- calls explicitly generate any required checks. We also need it
1559 -- only if we are doing standard validity checks, since clearly it
1560 -- is not needed if validity checks are off, and in subscript
1561 -- validity checking mode, all indexed components are checked with
1562 -- a call directly from Expand_N_Indexed_Component.
1564 if Comes_From_Source (N)
1565 and then Ekind (Formal) /= E_In_Parameter
1566 and then Validity_Checks_On
1567 and then Validity_Check_Default
1568 and then not Validity_Check_Subscripts
1570 Check_Valid_Lvalue_Subscripts (Actual);
1573 -- Mark any scalar OUT parameter that is a simple variable
1574 -- as no longer known to be valid (unless the type is always
1575 -- valid). This reflects the fact that if an OUT parameter
1576 -- is never set in a procedure, then it can become invalid
1577 -- on return from the procedure.
1579 if Ekind (Formal) = E_Out_Parameter
1580 and then Is_Entity_Name (Actual)
1581 and then Ekind (Entity (Actual)) = E_Variable
1582 and then not Is_Known_Valid (Etype (Actual))
1584 Set_Is_Known_Valid (Entity (Actual), False);
1587 -- For an OUT or IN OUT parameter of an access type, if the
1588 -- actual is an entity, then it is no longer known to be non-null.
1590 if Ekind (Formal) /= E_In_Parameter
1591 and then Is_Entity_Name (Actual)
1592 and then Is_Access_Type (Etype (Actual))
1594 Set_Is_Known_Non_Null (Entity (Actual), False);
1597 -- If the formal is class wide and the actual is an aggregate, force
1598 -- evaluation so that the back end who does not know about class-wide
1599 -- type, does not generate a temporary of the wrong size.
1601 if not Is_Class_Wide_Type (Etype (Formal)) then
1604 elsif Nkind (Actual) = N_Aggregate
1605 or else (Nkind (Actual) = N_Qualified_Expression
1606 and then Nkind (Expression (Actual)) = N_Aggregate)
1608 Force_Evaluation (Actual);
1611 -- In a remote call, if the formal is of a class-wide type, check
1612 -- that the actual meets the requirements described in E.4(18).
1615 and then Is_Class_Wide_Type (Etype (Formal))
1617 Insert_Action (Actual,
1618 Make_Implicit_If_Statement (N,
1621 Get_Remotely_Callable
1622 (Duplicate_Subexpr_Move_Checks (Actual))),
1623 Then_Statements => New_List (
1624 Make_Procedure_Call_Statement (Loc,
1625 New_Occurrence_Of (RTE
1626 (RE_Raise_Program_Error_For_E_4_18), Loc)))));
1629 Next_Actual (Actual);
1630 Next_Formal (Formal);
1633 -- If we are expanding a rhs of an assignement we need to check if
1634 -- tag propagation is needed. This code belongs theorically in Analyze
1635 -- Assignment but has to be done earlier (bottom-up) because the
1636 -- assignment might be transformed into a declaration for an uncons-
1637 -- trained value, if the expression is classwide.
1639 if Nkind (N) = N_Function_Call
1640 and then Is_Tag_Indeterminate (N)
1641 and then Is_Entity_Name (Name (N))
1644 Ass : Node_Id := Empty;
1647 if Nkind (Parent (N)) = N_Assignment_Statement then
1650 elsif Nkind (Parent (N)) = N_Qualified_Expression
1651 and then Nkind (Parent (Parent (N))) = N_Assignment_Statement
1653 Ass := Parent (Parent (N));
1657 and then Is_Class_Wide_Type (Etype (Name (Ass)))
1659 if Etype (N) /= Root_Type (Etype (Name (Ass))) then
1661 ("tag-indeterminate expression must have type&"
1662 & "('R'M 5.2 (6))", N, Root_Type (Etype (Name (Ass))));
1664 Propagate_Tag (Name (Ass), N);
1667 -- The call will be rewritten as a dispatching call, and
1668 -- expanded as such.
1675 -- Deals with Dispatch_Call if we still have a call, before expanding
1676 -- extra actuals since this will be done on the re-analysis of the
1677 -- dispatching call. Note that we do not try to shorten the actual
1678 -- list for a dispatching call, it would not make sense to do so.
1679 -- Expansion of dispatching calls is suppressed when Java_VM, because
1680 -- the JVM back end directly handles the generation of dispatching
1681 -- calls and would have to undo any expansion to an indirect call.
1683 if (Nkind (N) = N_Function_Call
1684 or else Nkind (N) = N_Procedure_Call_Statement)
1685 and then Present (Controlling_Argument (N))
1686 and then not Java_VM
1688 Expand_Dispatch_Call (N);
1690 -- The following return is worrisome. Is it really OK to
1691 -- skip all remaining processing in this procedure ???
1695 -- Similarly, expand calls to RCI subprograms on which pragma
1696 -- All_Calls_Remote applies. The rewriting will be reanalyzed
1697 -- later. Do this only when the call comes from source since we do
1698 -- not want such a rewritting to occur in expanded code.
1700 elsif Is_All_Remote_Call (N) then
1701 Expand_All_Calls_Remote_Subprogram_Call (N);
1703 -- Similarly, do not add extra actuals for an entry call whose entity
1704 -- is a protected procedure, or for an internal protected subprogram
1705 -- call, because it will be rewritten as a protected subprogram call
1706 -- and reanalyzed (see Expand_Protected_Subprogram_Call).
1708 elsif Is_Protected_Type (Scope (Subp))
1709 and then (Ekind (Subp) = E_Procedure
1710 or else Ekind (Subp) = E_Function)
1714 -- During that loop we gathered the extra actuals (the ones that
1715 -- correspond to Extra_Formals), so now they can be appended.
1718 while Is_Non_Empty_List (Extra_Actuals) loop
1719 Add_Actual_Parameter (Remove_Head (Extra_Actuals));
1723 if Ekind (Subp) = E_Procedure
1724 or else (Ekind (Subp) = E_Subprogram_Type
1725 and then Etype (Subp) = Standard_Void_Type)
1726 or else Is_Entry (Subp)
1728 Expand_Actuals (N, Subp);
1731 -- If the subprogram is a renaming, or if it is inherited, replace it
1732 -- in the call with the name of the actual subprogram being called.
1733 -- If this is a dispatching call, the run-time decides what to call.
1734 -- The Alias attribute does not apply to entries.
1736 if Nkind (N) /= N_Entry_Call_Statement
1737 and then No (Controlling_Argument (N))
1738 and then Present (Parent_Subp)
1740 if Present (Inherited_From_Formal (Subp)) then
1741 Parent_Subp := Inherited_From_Formal (Subp);
1743 while Present (Alias (Parent_Subp)) loop
1744 Parent_Subp := Alias (Parent_Subp);
1748 Set_Entity (Name (N), Parent_Subp);
1750 if Is_Abstract (Parent_Subp)
1751 and then not In_Instance
1754 ("cannot call abstract subprogram &!", Name (N), Parent_Subp);
1757 -- Add an explicit conversion for parameter of the derived type.
1758 -- This is only done for scalar and access in-parameters. Others
1759 -- have been expanded in expand_actuals.
1761 Formal := First_Formal (Subp);
1762 Parent_Formal := First_Formal (Parent_Subp);
1763 Actual := First_Actual (N);
1765 -- It is not clear that conversion is needed for intrinsic
1766 -- subprograms, but it certainly is for those that are user-
1767 -- defined, and that can be inherited on derivation, namely
1768 -- unchecked conversion and deallocation.
1769 -- General case needs study ???
1771 if not Is_Intrinsic_Subprogram (Parent_Subp)
1772 or else Is_Generic_Instance (Parent_Subp)
1774 while Present (Formal) loop
1776 if Etype (Formal) /= Etype (Parent_Formal)
1777 and then Is_Scalar_Type (Etype (Formal))
1778 and then Ekind (Formal) = E_In_Parameter
1779 and then not Raises_Constraint_Error (Actual)
1782 OK_Convert_To (Etype (Parent_Formal),
1783 Relocate_Node (Actual)));
1786 Resolve (Actual, Etype (Parent_Formal));
1787 Enable_Range_Check (Actual);
1789 elsif Is_Access_Type (Etype (Formal))
1790 and then Base_Type (Etype (Parent_Formal))
1791 /= Base_Type (Etype (Actual))
1793 if Ekind (Formal) /= E_In_Parameter then
1795 Convert_To (Etype (Parent_Formal),
1796 Relocate_Node (Actual)));
1799 Resolve (Actual, Etype (Parent_Formal));
1802 Ekind (Etype (Parent_Formal)) = E_Anonymous_Access_Type
1803 and then Designated_Type (Etype (Parent_Formal))
1805 Designated_Type (Etype (Actual))
1806 and then not Is_Controlling_Formal (Formal)
1808 -- This unchecked conversion is not necessary unless
1809 -- inlining is enabled, because in that case the type
1810 -- mismatch may become visible in the body about to be
1814 Unchecked_Convert_To (Etype (Parent_Formal),
1815 Relocate_Node (Actual)));
1818 Resolve (Actual, Etype (Parent_Formal));
1822 Next_Formal (Formal);
1823 Next_Formal (Parent_Formal);
1824 Next_Actual (Actual);
1829 Subp := Parent_Subp;
1832 if Is_RTE (Subp, RE_Abort_Task) then
1833 Check_Restriction (No_Abort_Statements, N);
1836 if Nkind (Name (N)) = N_Explicit_Dereference then
1838 -- Handle case of access to protected subprogram type
1840 if Ekind (Base_Type (Etype (Prefix (Name (N))))) =
1841 E_Access_Protected_Subprogram_Type
1843 -- If this is a call through an access to protected operation,
1844 -- the prefix has the form (object'address, operation'access).
1845 -- Rewrite as a for other protected calls: the object is the
1846 -- first parameter of the list of actuals.
1853 Ptr : constant Node_Id := Prefix (Name (N));
1855 T : constant Entity_Id :=
1856 Equivalent_Type (Base_Type (Etype (Ptr)));
1858 D_T : constant Entity_Id :=
1859 Designated_Type (Base_Type (Etype (Ptr)));
1862 Obj := Make_Selected_Component (Loc,
1863 Prefix => Unchecked_Convert_To (T, Ptr),
1864 Selector_Name => New_Occurrence_Of (First_Entity (T), Loc));
1866 Nam := Make_Selected_Component (Loc,
1867 Prefix => Unchecked_Convert_To (T, Ptr),
1868 Selector_Name => New_Occurrence_Of (
1869 Next_Entity (First_Entity (T)), Loc));
1871 Nam := Make_Explicit_Dereference (Loc, Nam);
1873 if Present (Parameter_Associations (N)) then
1874 Parm := Parameter_Associations (N);
1879 Prepend (Obj, Parm);
1881 if Etype (D_T) = Standard_Void_Type then
1882 Call := Make_Procedure_Call_Statement (Loc,
1884 Parameter_Associations => Parm);
1886 Call := Make_Function_Call (Loc,
1888 Parameter_Associations => Parm);
1891 Set_First_Named_Actual (Call, First_Named_Actual (N));
1892 Set_Etype (Call, Etype (D_T));
1894 -- We do not re-analyze the call to avoid infinite recursion.
1895 -- We analyze separately the prefix and the object, and set
1896 -- the checks on the prefix that would otherwise be emitted
1897 -- when resolving a call.
1901 Apply_Access_Check (Nam);
1908 -- If this is a call to an intrinsic subprogram, then perform the
1909 -- appropriate expansion to the corresponding tree node and we
1910 -- are all done (since after that the call is gone!)
1912 if Is_Intrinsic_Subprogram (Subp) then
1913 Expand_Intrinsic_Call (N, Subp);
1917 if Ekind (Subp) = E_Function
1918 or else Ekind (Subp) = E_Procedure
1920 if Is_Inlined (Subp) then
1922 Inlined_Subprogram : declare
1924 Must_Inline : Boolean := False;
1925 Spec : constant Node_Id := Unit_Declaration_Node (Subp);
1926 Scop : constant Entity_Id := Scope (Subp);
1928 function In_Unfrozen_Instance return Boolean;
1929 -- If the subprogram comes from an instance in the same
1930 -- unit, and the instance is not yet frozen, inlining might
1931 -- trigger order-of-elaboration problems in gigi.
1933 --------------------------
1934 -- In_Unfrozen_Instance --
1935 --------------------------
1937 function In_Unfrozen_Instance return Boolean is
1938 S : Entity_Id := Scop;
1942 and then S /= Standard_Standard
1944 if Is_Generic_Instance (S)
1945 and then Present (Freeze_Node (S))
1946 and then not Analyzed (Freeze_Node (S))
1955 end In_Unfrozen_Instance;
1957 -- Start of processing for Inlined_Subprogram
1960 -- Verify that the body to inline has already been seen,
1961 -- and that if the body is in the current unit the inlining
1962 -- does not occur earlier. This avoids order-of-elaboration
1963 -- problems in gigi.
1966 or else Nkind (Spec) /= N_Subprogram_Declaration
1967 or else No (Body_To_Inline (Spec))
1969 Must_Inline := False;
1971 -- If this an inherited function that returns a private
1972 -- type, do not inline if the full view is an unconstrained
1973 -- array, because such calls cannot be inlined.
1975 elsif Present (Orig_Subp)
1976 and then Is_Array_Type (Etype (Orig_Subp))
1977 and then not Is_Constrained (Etype (Orig_Subp))
1979 Must_Inline := False;
1981 elsif In_Unfrozen_Instance then
1982 Must_Inline := False;
1985 Bod := Body_To_Inline (Spec);
1987 if (In_Extended_Main_Code_Unit (N)
1988 or else In_Extended_Main_Code_Unit (Parent (N))
1989 or else Is_Always_Inlined (Subp))
1990 and then (not In_Same_Extended_Unit (Sloc (Bod), Loc)
1992 Earlier_In_Extended_Unit (Sloc (Bod), Loc))
1994 Must_Inline := True;
1996 -- If we are compiling a package body that is not the main
1997 -- unit, it must be for inlining/instantiation purposes,
1998 -- in which case we inline the call to insure that the same
1999 -- temporaries are generated when compiling the body by
2000 -- itself. Otherwise link errors can occur.
2002 elsif not (In_Extended_Main_Code_Unit (N))
2003 and then In_Package_Body
2005 Must_Inline := True;
2010 Expand_Inlined_Call (N, Subp, Orig_Subp);
2013 -- Let the back end handle it
2015 Add_Inlined_Body (Subp);
2017 if Front_End_Inlining
2018 and then Nkind (Spec) = N_Subprogram_Declaration
2019 and then (In_Extended_Main_Code_Unit (N))
2020 and then No (Body_To_Inline (Spec))
2021 and then not Has_Completion (Subp)
2022 and then In_Same_Extended_Unit (Sloc (Spec), Loc)
2025 ("cannot inline& (body not seen yet)?",
2029 end Inlined_Subprogram;
2033 -- Check for a protected subprogram. This is either an intra-object
2034 -- call, or a protected function call. Protected procedure calls are
2035 -- rewritten as entry calls and handled accordingly.
2037 Scop := Scope (Subp);
2039 if Nkind (N) /= N_Entry_Call_Statement
2040 and then Is_Protected_Type (Scop)
2042 -- If the call is an internal one, it is rewritten as a call to
2043 -- to the corresponding unprotected subprogram.
2045 Expand_Protected_Subprogram_Call (N, Subp, Scop);
2048 -- Functions returning controlled objects need special attention
2050 if Controlled_Type (Etype (Subp))
2051 and then not Is_Return_By_Reference_Type (Etype (Subp))
2053 Expand_Ctrl_Function_Call (N);
2056 -- Test for First_Optional_Parameter, and if so, truncate parameter
2057 -- list if there are optional parameters at the trailing end.
2058 -- Note we never delete procedures for call via a pointer.
2060 if (Ekind (Subp) = E_Procedure or else Ekind (Subp) = E_Function)
2061 and then Present (First_Optional_Parameter (Subp))
2064 Last_Keep_Arg : Node_Id;
2067 -- Last_Keep_Arg will hold the last actual that should be
2068 -- retained. If it remains empty at the end, it means that
2069 -- all parameters are optional.
2071 Last_Keep_Arg := Empty;
2073 -- Find first optional parameter, must be present since we
2074 -- checked the validity of the parameter before setting it.
2076 Formal := First_Formal (Subp);
2077 Actual := First_Actual (N);
2078 while Formal /= First_Optional_Parameter (Subp) loop
2079 Last_Keep_Arg := Actual;
2080 Next_Formal (Formal);
2081 Next_Actual (Actual);
2084 -- We have Formal and Actual pointing to the first potentially
2085 -- droppable argument. We can drop all the trailing arguments
2086 -- whose actual matches the default. Note that we know that all
2087 -- remaining formals have defaults, because we checked that this
2088 -- requirement was met before setting First_Optional_Parameter.
2090 -- We use Fully_Conformant_Expressions to check for identity
2091 -- between formals and actuals, which may miss some cases, but
2092 -- on the other hand, this is only an optimization (if we fail
2093 -- to truncate a parameter it does not affect functionality).
2094 -- So if the default is 3 and the actual is 1+2, we consider
2095 -- them unequal, which hardly seems worrisome.
2097 while Present (Formal) loop
2098 if not Fully_Conformant_Expressions
2099 (Actual, Default_Value (Formal))
2101 Last_Keep_Arg := Actual;
2104 Next_Formal (Formal);
2105 Next_Actual (Actual);
2108 -- If no arguments, delete entire list, this is the easy case
2110 if No (Last_Keep_Arg) then
2111 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2112 Delete_Tree (Remove_Head (Parameter_Associations (N)));
2115 Set_Parameter_Associations (N, No_List);
2116 Set_First_Named_Actual (N, Empty);
2118 -- Case where at the last retained argument is positional. This
2119 -- is also an easy case, since the retained arguments are already
2120 -- in the right form, and we don't need to worry about the order
2121 -- of arguments that get eliminated.
2123 elsif Is_List_Member (Last_Keep_Arg) then
2124 while Present (Next (Last_Keep_Arg)) loop
2125 Delete_Tree (Remove_Next (Last_Keep_Arg));
2128 Set_First_Named_Actual (N, Empty);
2130 -- This is the annoying case where the last retained argument
2131 -- is a named parameter. Since the original arguments are not
2132 -- in declaration order, we may have to delete some fairly
2133 -- random collection of arguments.
2141 pragma Warnings (Off, Discard);
2144 -- First step, remove all the named parameters from the
2145 -- list (they are still chained using First_Named_Actual
2146 -- and Next_Named_Actual, so we have not lost them!)
2148 Temp := First (Parameter_Associations (N));
2150 -- Case of all parameters named, remove them all
2152 if Nkind (Temp) = N_Parameter_Association then
2153 while Is_Non_Empty_List (Parameter_Associations (N)) loop
2154 Temp := Remove_Head (Parameter_Associations (N));
2157 -- Case of mixed positional/named, remove named parameters
2160 while Nkind (Next (Temp)) /= N_Parameter_Association loop
2164 while Present (Next (Temp)) loop
2165 Discard := Remove_Next (Temp);
2169 -- Now we loop through the named parameters, till we get
2170 -- to the last one to be retained, adding them to the list.
2171 -- Note that the Next_Named_Actual list does not need to be
2172 -- touched since we are only reordering them on the actual
2173 -- parameter association list.
2175 Passoc := Parent (First_Named_Actual (N));
2177 Temp := Relocate_Node (Passoc);
2179 (Parameter_Associations (N), Temp);
2181 Last_Keep_Arg = Explicit_Actual_Parameter (Passoc);
2182 Passoc := Parent (Next_Named_Actual (Passoc));
2185 Set_Next_Named_Actual (Temp, Empty);
2188 Temp := Next_Named_Actual (Passoc);
2189 exit when No (Temp);
2190 Set_Next_Named_Actual
2191 (Passoc, Next_Named_Actual (Parent (Temp)));
2200 --------------------------
2201 -- Expand_Inlined_Call --
2202 --------------------------
2204 procedure Expand_Inlined_Call
2207 Orig_Subp : Entity_Id)
2209 Loc : constant Source_Ptr := Sloc (N);
2210 Is_Predef : constant Boolean :=
2211 Is_Predefined_File_Name
2212 (Unit_File_Name (Get_Source_Unit (Subp)));
2213 Orig_Bod : constant Node_Id :=
2214 Body_To_Inline (Unit_Declaration_Node (Subp));
2219 Exit_Lab : Entity_Id := Empty;
2226 Ret_Type : Entity_Id;
2229 Temp_Typ : Entity_Id;
2231 procedure Make_Exit_Label;
2232 -- Build declaration for exit label to be used in Return statements.
2234 function Process_Formals (N : Node_Id) return Traverse_Result;
2235 -- Replace occurrence of a formal with the corresponding actual, or
2236 -- the thunk generated for it.
2238 function Process_Sloc (Nod : Node_Id) return Traverse_Result;
2239 -- If the call being expanded is that of an internal subprogram,
2240 -- set the sloc of the generated block to that of the call itself,
2241 -- so that the expansion is skipped by the -next- command in gdb.
2242 -- Same processing for a subprogram in a predefined file, e.g.
2243 -- Ada.Tags. If Debug_Generated_Code is true, suppress this change
2244 -- to simplify our own development.
2246 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id);
2247 -- If the function body is a single expression, replace call with
2248 -- expression, else insert block appropriately.
2250 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id);
2251 -- If procedure body has no local variables, inline body without
2252 -- creating block, otherwise rewrite call with block.
2254 ---------------------
2255 -- Make_Exit_Label --
2256 ---------------------
2258 procedure Make_Exit_Label is
2260 -- Create exit label for subprogram, if one doesn't exist yet.
2262 if No (Exit_Lab) then
2263 Lab_Id := Make_Identifier (Loc, New_Internal_Name ('L'));
2265 Make_Defining_Identifier (Loc, Chars (Lab_Id)));
2266 Exit_Lab := Make_Label (Loc, Lab_Id);
2269 Make_Implicit_Label_Declaration (Loc,
2270 Defining_Identifier => Entity (Lab_Id),
2271 Label_Construct => Exit_Lab);
2273 end Make_Exit_Label;
2275 ---------------------
2276 -- Process_Formals --
2277 ---------------------
2279 function Process_Formals (N : Node_Id) return Traverse_Result is
2285 if Is_Entity_Name (N)
2286 and then Present (Entity (N))
2291 and then Scope (E) = Subp
2293 A := Renamed_Object (E);
2295 if Is_Entity_Name (A) then
2296 Rewrite (N, New_Occurrence_Of (Entity (A), Loc));
2298 elsif Nkind (A) = N_Defining_Identifier then
2299 Rewrite (N, New_Occurrence_Of (A, Loc));
2301 else -- numeric literal
2302 Rewrite (N, New_Copy (A));
2308 elsif Nkind (N) = N_Return_Statement then
2310 if No (Expression (N)) then
2312 Rewrite (N, Make_Goto_Statement (Loc,
2313 Name => New_Copy (Lab_Id)));
2316 if Nkind (Parent (N)) = N_Handled_Sequence_Of_Statements
2317 and then Nkind (Parent (Parent (N))) = N_Subprogram_Body
2319 -- Function body is a single expression. No need for
2325 Num_Ret := Num_Ret + 1;
2329 -- Because of the presence of private types, the views of the
2330 -- expression and the context may be different, so place an
2331 -- unchecked conversion to the context type to avoid spurious
2332 -- errors, eg. when the expression is a numeric literal and
2333 -- the context is private. If the expression is an aggregate,
2334 -- use a qualified expression, because an aggregate is not a
2335 -- legal argument of a conversion.
2337 if Nkind (Expression (N)) = N_Aggregate
2338 or else Nkind (Expression (N)) = N_Null
2341 Make_Qualified_Expression (Sloc (N),
2342 Subtype_Mark => New_Occurrence_Of (Ret_Type, Sloc (N)),
2343 Expression => Relocate_Node (Expression (N)));
2346 Unchecked_Convert_To
2347 (Ret_Type, Relocate_Node (Expression (N)));
2350 if Nkind (Targ) = N_Defining_Identifier then
2352 Make_Assignment_Statement (Loc,
2353 Name => New_Occurrence_Of (Targ, Loc),
2354 Expression => Ret));
2357 Make_Assignment_Statement (Loc,
2358 Name => New_Copy (Targ),
2359 Expression => Ret));
2362 Set_Assignment_OK (Name (N));
2364 if Present (Exit_Lab) then
2366 Make_Goto_Statement (Loc,
2367 Name => New_Copy (Lab_Id)));
2373 -- Remove pragma Unreferenced since it may refer to formals that
2374 -- are not visible in the inlined body, and in any case we will
2375 -- not be posting warnings on the inlined body so it is unneeded.
2377 elsif Nkind (N) = N_Pragma
2378 and then Chars (N) = Name_Unreferenced
2380 Rewrite (N, Make_Null_Statement (Sloc (N)));
2386 end Process_Formals;
2388 procedure Replace_Formals is new Traverse_Proc (Process_Formals);
2394 function Process_Sloc (Nod : Node_Id) return Traverse_Result is
2396 if not Debug_Generated_Code then
2397 Set_Sloc (Nod, Sloc (N));
2398 Set_Comes_From_Source (Nod, False);
2404 procedure Reset_Slocs is new Traverse_Proc (Process_Sloc);
2406 ---------------------------
2407 -- Rewrite_Function_Call --
2408 ---------------------------
2410 procedure Rewrite_Function_Call (N : Node_Id; Blk : Node_Id) is
2411 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
2412 Fst : constant Node_Id := First (Statements (HSS));
2415 -- Optimize simple case: function body is a single return statement,
2416 -- which has been expanded into an assignment.
2418 if Is_Empty_List (Declarations (Blk))
2419 and then Nkind (Fst) = N_Assignment_Statement
2420 and then No (Next (Fst))
2423 -- The function call may have been rewritten as the temporary
2424 -- that holds the result of the call, in which case remove the
2425 -- now useless declaration.
2427 if Nkind (N) = N_Identifier
2428 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2430 Rewrite (Parent (Entity (N)), Make_Null_Statement (Loc));
2433 Rewrite (N, Expression (Fst));
2435 elsif Nkind (N) = N_Identifier
2436 and then Nkind (Parent (Entity (N))) = N_Object_Declaration
2439 -- The block assigns the result of the call to the temporary.
2441 Insert_After (Parent (Entity (N)), Blk);
2443 elsif Nkind (Parent (N)) = N_Assignment_Statement
2444 and then Is_Entity_Name (Name (Parent (N)))
2447 -- Replace assignment with the block
2449 Rewrite (Parent (N), Blk);
2451 elsif Nkind (Parent (N)) = N_Object_Declaration then
2452 Set_Expression (Parent (N), Empty);
2453 Insert_After (Parent (N), Blk);
2455 end Rewrite_Function_Call;
2457 ----------------------------
2458 -- Rewrite_Procedure_Call --
2459 ----------------------------
2461 procedure Rewrite_Procedure_Call (N : Node_Id; Blk : Node_Id) is
2462 HSS : constant Node_Id := Handled_Statement_Sequence (Blk);
2465 if Is_Empty_List (Declarations (Blk)) then
2466 Insert_List_After (N, Statements (HSS));
2467 Rewrite (N, Make_Null_Statement (Loc));
2471 end Rewrite_Procedure_Call;
2473 -- Start of processing for Expand_Inlined_Call
2476 -- Check for special case of To_Address call, and if so, just
2477 -- do an unchecked conversion instead of expanding the call.
2478 -- Not only is this more efficient, but it also avoids a
2479 -- problem with order of elaboration when address clauses
2480 -- are inlined (address expr elaborated at wrong point).
2482 if Subp = RTE (RE_To_Address) then
2484 Unchecked_Convert_To
2486 Relocate_Node (First_Actual (N))));
2490 if Nkind (Orig_Bod) = N_Defining_Identifier then
2492 -- Subprogram is a renaming_as_body. Calls appearing after the
2493 -- renaming can be replaced with calls to the renamed entity
2494 -- directly, because the subprograms are subtype conformant.
2496 Set_Name (N, New_Occurrence_Of (Orig_Bod, Loc));
2500 -- Use generic machinery to copy body of inlined subprogram, as if it
2501 -- were an instantiation, resetting source locations appropriately, so
2502 -- that nested inlined calls appear in the main unit.
2504 Save_Env (Subp, Empty);
2505 Set_Copied_Sloc_For_Inlined_Body (N, Defining_Entity (Orig_Bod));
2507 Bod := Copy_Generic_Node (Orig_Bod, Empty, Instantiating => True);
2509 Make_Block_Statement (Loc,
2510 Declarations => Declarations (Bod),
2511 Handled_Statement_Sequence => Handled_Statement_Sequence (Bod));
2513 if No (Declarations (Bod)) then
2514 Set_Declarations (Blk, New_List);
2517 -- If this is a derived function, establish the proper return type.
2519 if Present (Orig_Subp)
2520 and then Orig_Subp /= Subp
2522 Ret_Type := Etype (Orig_Subp);
2524 Ret_Type := Etype (Subp);
2527 F := First_Formal (Subp);
2528 A := First_Actual (N);
2530 -- Create temporaries for the actuals that are expressions, or that
2531 -- are scalars and require copying to preserve semantics.
2533 while Present (F) loop
2534 if Present (Renamed_Object (F)) then
2535 Error_Msg_N (" cannot inline call to recursive subprogram", N);
2539 -- If the argument may be a controlling argument in a call within
2540 -- the inlined body, we must preserve its classwide nature to
2541 -- insure that dynamic dispatching take place subsequently.
2542 -- If the formal has a constraint it must be preserved to retain
2543 -- the semantics of the body.
2545 if Is_Class_Wide_Type (Etype (F))
2546 or else (Is_Access_Type (Etype (F))
2548 Is_Class_Wide_Type (Designated_Type (Etype (F))))
2550 Temp_Typ := Etype (F);
2552 elsif Base_Type (Etype (F)) = Base_Type (Etype (A))
2553 and then Etype (F) /= Base_Type (Etype (F))
2555 Temp_Typ := Etype (F);
2558 Temp_Typ := Etype (A);
2561 -- If the actual is a simple name or a literal, no need to
2562 -- create a temporary, object can be used directly.
2564 if (Is_Entity_Name (A)
2566 (not Is_Scalar_Type (Etype (A))
2567 or else Ekind (Entity (A)) = E_Enumeration_Literal))
2569 or else Nkind (A) = N_Real_Literal
2570 or else Nkind (A) = N_Integer_Literal
2571 or else Nkind (A) = N_Character_Literal
2573 if Etype (F) /= Etype (A) then
2575 (F, Unchecked_Convert_To (Etype (F), Relocate_Node (A)));
2577 Set_Renamed_Object (F, A);
2582 Make_Defining_Identifier (Loc,
2583 Chars => New_Internal_Name ('C'));
2585 -- If the actual for an in/in-out parameter is a view conversion,
2586 -- make it into an unchecked conversion, given that an untagged
2587 -- type conversion is not a proper object for a renaming.
2589 -- In-out conversions that involve real conversions have already
2590 -- been transformed in Expand_Actuals.
2592 if Nkind (A) = N_Type_Conversion
2593 and then Ekind (F) /= E_In_Parameter
2595 New_A := Make_Unchecked_Type_Conversion (Loc,
2596 Subtype_Mark => New_Occurrence_Of (Etype (F), Loc),
2597 Expression => Relocate_Node (Expression (A)));
2599 elsif Etype (F) /= Etype (A) then
2600 New_A := Unchecked_Convert_To (Etype (F), Relocate_Node (A));
2601 Temp_Typ := Etype (F);
2604 New_A := Relocate_Node (A);
2607 Set_Sloc (New_A, Sloc (N));
2609 if Ekind (F) = E_In_Parameter
2610 and then not Is_Limited_Type (Etype (A))
2613 Make_Object_Declaration (Loc,
2614 Defining_Identifier => Temp,
2615 Constant_Present => True,
2616 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
2617 Expression => New_A);
2620 Make_Object_Renaming_Declaration (Loc,
2621 Defining_Identifier => Temp,
2622 Subtype_Mark => New_Occurrence_Of (Temp_Typ, Loc),
2626 Prepend (Decl, Declarations (Blk));
2627 Set_Renamed_Object (F, Temp);
2634 -- Establish target of function call. If context is not assignment or
2635 -- declaration, create a temporary as a target. The declaration for
2636 -- the temporary may be subsequently optimized away if the body is a
2637 -- single expression, or if the left-hand side of the assignment is
2640 if Ekind (Subp) = E_Function then
2641 if Nkind (Parent (N)) = N_Assignment_Statement
2642 and then Is_Entity_Name (Name (Parent (N)))
2644 Targ := Name (Parent (N));
2647 -- Replace call with temporary, and create its declaration.
2650 Make_Defining_Identifier (Loc, New_Internal_Name ('C'));
2653 Make_Object_Declaration (Loc,
2654 Defining_Identifier => Temp,
2655 Object_Definition =>
2656 New_Occurrence_Of (Ret_Type, Loc));
2658 Set_No_Initialization (Decl);
2659 Insert_Action (N, Decl);
2660 Rewrite (N, New_Occurrence_Of (Temp, Loc));
2665 -- Traverse the tree and replace formals with actuals or their thunks.
2666 -- Attach block to tree before analysis and rewriting.
2668 Replace_Formals (Blk);
2669 Set_Parent (Blk, N);
2671 if not Comes_From_Source (Subp)
2677 if Present (Exit_Lab) then
2679 -- If the body was a single expression, the single return statement
2680 -- and the corresponding label are useless.
2684 Nkind (Last (Statements (Handled_Statement_Sequence (Blk)))) =
2687 Remove (Last (Statements (Handled_Statement_Sequence (Blk))));
2689 Append (Lab_Decl, (Declarations (Blk)));
2690 Append (Exit_Lab, Statements (Handled_Statement_Sequence (Blk)));
2694 -- Analyze Blk with In_Inlined_Body set, to avoid spurious errors on
2695 -- conflicting private views that Gigi would ignore. If this is a
2696 -- predefined unit, analyze with checks off, as is done in the non-
2697 -- inlined run-time units.
2700 I_Flag : constant Boolean := In_Inlined_Body;
2703 In_Inlined_Body := True;
2707 Style : constant Boolean := Style_Check;
2709 Style_Check := False;
2710 Analyze (Blk, Suppress => All_Checks);
2711 Style_Check := Style;
2718 In_Inlined_Body := I_Flag;
2721 if Ekind (Subp) = E_Procedure then
2722 Rewrite_Procedure_Call (N, Blk);
2724 Rewrite_Function_Call (N, Blk);
2729 -- Cleanup mapping between formals and actuals, for other expansions.
2731 F := First_Formal (Subp);
2733 while Present (F) loop
2734 Set_Renamed_Object (F, Empty);
2737 end Expand_Inlined_Call;
2739 ----------------------------
2740 -- Expand_N_Function_Call --
2741 ----------------------------
2743 procedure Expand_N_Function_Call (N : Node_Id) is
2744 Typ : constant Entity_Id := Etype (N);
2746 function Returned_By_Reference return Boolean;
2747 -- If the return type is returned through the secondary stack. that is
2748 -- by reference, we don't want to create a temp to force stack checking.
2750 function Returned_By_Reference return Boolean is
2751 S : Entity_Id := Current_Scope;
2754 if Is_Return_By_Reference_Type (Typ) then
2757 elsif Nkind (Parent (N)) /= N_Return_Statement then
2760 elsif Requires_Transient_Scope (Typ) then
2762 -- Verify that the return type of the enclosing function has
2763 -- the same constrained status as that of the expression.
2765 while Ekind (S) /= E_Function loop
2769 return Is_Constrained (Typ) = Is_Constrained (Etype (S));
2773 end Returned_By_Reference;
2775 -- Start of processing for Expand_N_Function_Call
2778 -- A special check. If stack checking is enabled, and the return type
2779 -- might generate a large temporary, and the call is not the right
2780 -- side of an assignment, then generate an explicit temporary. We do
2781 -- this because otherwise gigi may generate a large temporary on the
2782 -- fly and this can cause trouble with stack checking.
2784 if May_Generate_Large_Temp (Typ)
2785 and then Nkind (Parent (N)) /= N_Assignment_Statement
2787 (Nkind (Parent (N)) /= N_Qualified_Expression
2788 or else Nkind (Parent (Parent (N))) /= N_Assignment_Statement)
2790 (Nkind (Parent (N)) /= N_Object_Declaration
2791 or else Expression (Parent (N)) /= N)
2792 and then not Returned_By_Reference
2794 -- Note: it might be thought that it would be OK to use a call to
2795 -- Force_Evaluation here, but that's not good enough, because that
2796 -- results in a 'Reference construct that may still need a temporary.
2799 Loc : constant Source_Ptr := Sloc (N);
2800 Temp_Obj : constant Entity_Id :=
2801 Make_Defining_Identifier (Loc,
2802 Chars => New_Internal_Name ('F'));
2803 Temp_Typ : Entity_Id := Typ;
2810 if Is_Tagged_Type (Typ)
2811 and then Present (Controlling_Argument (N))
2813 if Nkind (Parent (N)) /= N_Procedure_Call_Statement
2814 and then Nkind (Parent (N)) /= N_Function_Call
2816 -- If this is a tag-indeterminate call, the object must
2819 if Is_Tag_Indeterminate (N) then
2820 Temp_Typ := Class_Wide_Type (Typ);
2824 -- If this is a dispatching call that is itself the
2825 -- controlling argument of an enclosing call, the nominal
2826 -- subtype of the object that replaces it must be classwide,
2827 -- so that dispatching will take place properly. If it is
2828 -- not a controlling argument, the object is not classwide.
2830 Proc := Entity (Name (Parent (N)));
2831 F := First_Formal (Proc);
2832 A := First_Actual (Parent (N));
2839 if Is_Controlling_Formal (F) then
2840 Temp_Typ := Class_Wide_Type (Typ);
2846 Make_Object_Declaration (Loc,
2847 Defining_Identifier => Temp_Obj,
2848 Object_Definition => New_Occurrence_Of (Temp_Typ, Loc),
2849 Constant_Present => True,
2850 Expression => Relocate_Node (N));
2851 Set_Assignment_OK (Decl);
2853 Insert_Actions (N, New_List (Decl));
2854 Rewrite (N, New_Occurrence_Of (Temp_Obj, Loc));
2857 -- Normal case, expand the call
2862 end Expand_N_Function_Call;
2864 ---------------------------------------
2865 -- Expand_N_Procedure_Call_Statement --
2866 ---------------------------------------
2868 procedure Expand_N_Procedure_Call_Statement (N : Node_Id) is
2871 end Expand_N_Procedure_Call_Statement;
2873 ------------------------------
2874 -- Expand_N_Subprogram_Body --
2875 ------------------------------
2877 -- Add poll call if ATC polling is enabled
2879 -- Add return statement if last statement in body is not a return
2880 -- statement (this makes things easier on Gigi which does not want
2881 -- to have to handle a missing return).
2883 -- Add call to Activate_Tasks if body is a task activator
2885 -- Deal with possible detection of infinite recursion
2887 -- Eliminate body completely if convention stubbed
2889 -- Encode entity names within body, since we will not need to reference
2890 -- these entities any longer in the front end.
2892 -- Initialize scalar out parameters if Initialize/Normalize_Scalars
2894 -- Reset Pure indication if any parameter has root type System.Address
2898 procedure Expand_N_Subprogram_Body (N : Node_Id) is
2899 Loc : constant Source_Ptr := Sloc (N);
2900 H : constant Node_Id := Handled_Statement_Sequence (N);
2901 Body_Id : Entity_Id;
2902 Spec_Id : Entity_Id;
2909 procedure Add_Return (S : List_Id);
2910 -- Append a return statement to the statement sequence S if the last
2911 -- statement is not already a return or a goto statement. Note that
2912 -- the latter test is not critical, it does not matter if we add a
2913 -- few extra returns, since they get eliminated anyway later on.
2915 procedure Expand_Thread_Body;
2916 -- Perform required expansion of a thread body
2922 procedure Add_Return (S : List_Id) is
2924 if not Is_Transfer (Last (S)) then
2926 -- The source location for the return is the end label
2927 -- of the procedure in all cases. This is a bit odd when
2928 -- there are exception handlers, but not much else we can do.
2930 Append_To (S, Make_Return_Statement (Sloc (End_Label (H))));
2934 ------------------------
2935 -- Expand_Thread_Body --
2936 ------------------------
2938 -- The required expansion of a thread body is as follows
2940 -- procedure <thread body procedure name> is
2942 -- _Secondary_Stack : aliased
2943 -- Storage_Elements.Storage_Array
2944 -- (1 .. Storage_Offset (Sec_Stack_Size));
2945 -- for _Secondary_Stack'Alignment use Standard'Maximum_Alignment;
2947 -- _Process_ATSD : aliased System.Threads.ATSD;
2950 -- System.Threads.Thread_Body_Enter;
2951 -- (_Secondary_Stack'Address,
2952 -- _Secondary_Stack'Length,
2953 -- _Process_ATSD'Address);
2956 -- <user declarations>
2958 -- <user statements>
2959 -- <user exception handlers>
2962 -- System.Threads.Thread_Body_Leave;
2965 -- when E : others =>
2966 -- System.Threads.Thread_Body_Exceptional_Exit (E);
2969 -- Note the exception handler is omitted if pragma Restriction
2970 -- No_Exception_Handlers is currently active.
2972 procedure Expand_Thread_Body is
2973 User_Decls : constant List_Id := Declarations (N);
2974 Sec_Stack_Len : Node_Id;
2976 TB_Pragma : constant Node_Id :=
2977 Get_Rep_Pragma (Spec_Id, Name_Thread_Body);
2980 Ent_ATSD : Entity_Id;
2984 Decl_ATSD : Node_Id;
2986 Excep_Handlers : List_Id;
2989 New_Scope (Spec_Id);
2991 -- Get proper setting for secondary stack size
2993 if List_Length (Pragma_Argument_Associations (TB_Pragma)) = 2 then
2995 Expression (Last (Pragma_Argument_Associations (TB_Pragma)));
2998 New_Occurrence_Of (RTE (RE_Default_Secondary_Stack_Size), Loc);
3001 Sec_Stack_Len := Convert_To (RTE (RE_Storage_Offset), Sec_Stack_Len);
3003 -- Build and set declarations for the wrapped thread body
3005 Ent_SS := Make_Defining_Identifier (Loc, Name_uSecondary_Stack);
3006 Ent_ATSD := Make_Defining_Identifier (Loc, Name_uProcess_ATSD);
3009 Make_Object_Declaration (Loc,
3010 Defining_Identifier => Ent_SS,
3011 Aliased_Present => True,
3012 Object_Definition =>
3013 Make_Subtype_Indication (Loc,
3015 New_Occurrence_Of (RTE (RE_Storage_Array), Loc),
3017 Make_Index_Or_Discriminant_Constraint (Loc,
3018 Constraints => New_List (
3020 Low_Bound => Make_Integer_Literal (Loc, 1),
3021 High_Bound => Sec_Stack_Len)))));
3024 Make_Object_Declaration (Loc,
3025 Defining_Identifier => Ent_ATSD,
3026 Aliased_Present => True,
3027 Object_Definition => New_Occurrence_Of (RTE (RE_ATSD), Loc));
3029 Set_Declarations (N, New_List (Decl_SS, Decl_ATSD));
3031 Analyze (Decl_ATSD);
3032 Set_Alignment (Ent_SS, UI_From_Int (Maximum_Alignment));
3034 -- Create new exception handler
3036 if Restriction_Active (No_Exception_Handlers) then
3037 Excep_Handlers := No_List;
3040 Check_Restriction (No_Exception_Handlers, N);
3042 Ent_EO := Make_Defining_Identifier (Loc, Name_uE);
3044 Excep_Handlers := New_List (
3045 Make_Exception_Handler (Loc,
3046 Choice_Parameter => Ent_EO,
3047 Exception_Choices => New_List (
3048 Make_Others_Choice (Loc)),
3049 Statements => New_List (
3050 Make_Procedure_Call_Statement (Loc,
3053 (RTE (RE_Thread_Body_Exceptional_Exit), Loc),
3054 Parameter_Associations => New_List (
3055 New_Occurrence_Of (Ent_EO, Loc))))));
3058 -- Now build new handled statement sequence and analyze it
3060 Set_Handled_Statement_Sequence (N,
3061 Make_Handled_Sequence_Of_Statements (Loc,
3062 Statements => New_List (
3064 Make_Procedure_Call_Statement (Loc,
3065 Name => New_Occurrence_Of (RTE (RE_Thread_Body_Enter), Loc),
3066 Parameter_Associations => New_List (
3068 Make_Attribute_Reference (Loc,
3069 Prefix => New_Occurrence_Of (Ent_SS, Loc),
3070 Attribute_Name => Name_Address),
3072 Make_Attribute_Reference (Loc,
3073 Prefix => New_Occurrence_Of (Ent_SS, Loc),
3074 Attribute_Name => Name_Length),
3076 Make_Attribute_Reference (Loc,
3077 Prefix => New_Occurrence_Of (Ent_ATSD, Loc),
3078 Attribute_Name => Name_Address))),
3080 Make_Block_Statement (Loc,
3081 Declarations => User_Decls,
3082 Handled_Statement_Sequence => H),
3084 Make_Procedure_Call_Statement (Loc,
3085 Name => New_Occurrence_Of (RTE (RE_Thread_Body_Leave), Loc))),
3087 Exception_Handlers => Excep_Handlers));
3089 Analyze (Handled_Statement_Sequence (N));
3091 end Expand_Thread_Body;
3093 -- Start of processing for Expand_N_Subprogram_Body
3096 -- Set L to either the list of declarations if present, or
3097 -- to the list of statements if no declarations are present.
3098 -- This is used to insert new stuff at the start.
3100 if Is_Non_Empty_List (Declarations (N)) then
3101 L := Declarations (N);
3103 L := Statements (Handled_Statement_Sequence (N));
3106 -- Need poll on entry to subprogram if polling enabled. We only
3107 -- do this for non-empty subprograms, since it does not seem
3108 -- necessary to poll for a dummy null subprogram.
3110 if Is_Non_Empty_List (L) then
3111 Generate_Poll_Call (First (L));
3114 -- Find entity for subprogram
3116 Body_Id := Defining_Entity (N);
3118 if Present (Corresponding_Spec (N)) then
3119 Spec_Id := Corresponding_Spec (N);
3124 -- If this is a Pure function which has any parameters whose root
3125 -- type is System.Address, reset the Pure indication, since it will
3126 -- likely cause incorrect code to be generated as the parameter is
3127 -- probably a pointer, and the fact that the same pointer is passed
3128 -- does not mean that the same value is being referenced.
3130 -- Note that if the programmer gave an explicit Pure_Function pragma,
3131 -- then we believe the programmer, and leave the subprogram Pure.
3133 -- This code should probably be at the freeze point, so that it
3134 -- happens even on a -gnatc (or more importantly -gnatt) compile
3135 -- so that the semantic tree has Is_Pure set properly ???
3137 if Is_Pure (Spec_Id)
3138 and then Is_Subprogram (Spec_Id)
3139 and then not Has_Pragma_Pure_Function (Spec_Id)
3142 F : Entity_Id := First_Formal (Spec_Id);
3145 while Present (F) loop
3146 if Is_RTE (Root_Type (Etype (F)), RE_Address) then
3147 Set_Is_Pure (Spec_Id, False);
3149 if Spec_Id /= Body_Id then
3150 Set_Is_Pure (Body_Id, False);
3161 -- Initialize any scalar OUT args if Initialize/Normalize_Scalars
3163 if Init_Or_Norm_Scalars and then Is_Subprogram (Spec_Id) then
3165 F : Entity_Id := First_Formal (Spec_Id);
3166 V : constant Boolean := Validity_Checks_On;
3169 -- We turn off validity checking, since we do not want any
3170 -- check on the initializing value itself (which we know
3171 -- may well be invalid!)
3173 Validity_Checks_On := False;
3175 -- Loop through formals
3177 while Present (F) loop
3178 if Is_Scalar_Type (Etype (F))
3179 and then Ekind (F) = E_Out_Parameter
3181 Insert_Before_And_Analyze (First (L),
3182 Make_Assignment_Statement (Loc,
3183 Name => New_Occurrence_Of (F, Loc),
3184 Expression => Get_Simple_Init_Val (Etype (F), Loc)));
3190 Validity_Checks_On := V;
3194 -- Clear out statement list for stubbed procedure
3196 if Present (Corresponding_Spec (N)) then
3197 Set_Elaboration_Flag (N, Spec_Id);
3199 if Convention (Spec_Id) = Convention_Stubbed
3200 or else Is_Eliminated (Spec_Id)
3202 Set_Declarations (N, Empty_List);
3203 Set_Handled_Statement_Sequence (N,
3204 Make_Handled_Sequence_Of_Statements (Loc,
3205 Statements => New_List (
3206 Make_Null_Statement (Loc))));
3211 Scop := Scope (Spec_Id);
3213 -- Returns_By_Ref flag is normally set when the subprogram is frozen
3214 -- but subprograms with no specs are not frozen
3217 Typ : constant Entity_Id := Etype (Spec_Id);
3218 Utyp : constant Entity_Id := Underlying_Type (Typ);
3221 if not Acts_As_Spec (N)
3222 and then Nkind (Parent (Parent (Spec_Id))) /=
3223 N_Subprogram_Body_Stub
3227 elsif Is_Return_By_Reference_Type (Typ) then
3228 Set_Returns_By_Ref (Spec_Id);
3230 elsif Present (Utyp) and then Controlled_Type (Utyp) then
3231 Set_Returns_By_Ref (Spec_Id);
3235 -- For a procedure, we add a return for all possible syntactic ends
3236 -- of the subprogram. Note that reanalysis is not necessary in this
3237 -- case since it would require a lot of work and accomplish nothing.
3239 if Ekind (Spec_Id) = E_Procedure
3240 or else Ekind (Spec_Id) = E_Generic_Procedure
3242 Add_Return (Statements (H));
3244 if Present (Exception_Handlers (H)) then
3245 Except_H := First_Non_Pragma (Exception_Handlers (H));
3247 while Present (Except_H) loop
3248 Add_Return (Statements (Except_H));
3249 Next_Non_Pragma (Except_H);
3253 -- For a function, we must deal with the case where there is at
3254 -- least one missing return. What we do is to wrap the entire body
3255 -- of the function in a block:
3268 -- raise Program_Error;
3271 -- This approach is necessary because the raise must be signalled
3272 -- to the caller, not handled by any local handler (RM 6.4(11)).
3274 -- Note: we do not need to analyze the constructed sequence here,
3275 -- since it has no handler, and an attempt to analyze the handled
3276 -- statement sequence twice is risky in various ways (e.g. the
3277 -- issue of expanding cleanup actions twice).
3279 elsif Has_Missing_Return (Spec_Id) then
3281 Hloc : constant Source_Ptr := Sloc (H);
3282 Blok : constant Node_Id :=
3283 Make_Block_Statement (Hloc,
3284 Handled_Statement_Sequence => H);
3285 Rais : constant Node_Id :=
3286 Make_Raise_Program_Error (Hloc,
3287 Reason => PE_Missing_Return);
3290 Set_Handled_Statement_Sequence (N,
3291 Make_Handled_Sequence_Of_Statements (Hloc,
3292 Statements => New_List (Blok, Rais)));
3294 New_Scope (Spec_Id);
3301 -- Add discriminal renamings to protected subprograms.
3302 -- Install new discriminals for expansion of the next
3303 -- subprogram of this protected type, if any.
3305 if Is_List_Member (N)
3306 and then Present (Parent (List_Containing (N)))
3307 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
3309 Add_Discriminal_Declarations
3310 (Declarations (N), Scop, Name_uObject, Loc);
3311 Add_Private_Declarations (Declarations (N), Scop, Name_uObject, Loc);
3313 -- Associate privals and discriminals with the next protected
3314 -- operation body to be expanded. These are used to expand
3315 -- references to private data objects and discriminants,
3318 Next_Op := Next_Protected_Operation (N);
3320 if Present (Next_Op) then
3321 Dec := Parent (Base_Type (Scop));
3322 Set_Privals (Dec, Next_Op, Loc);
3323 Set_Discriminals (Dec);
3327 -- If subprogram contains a parameterless recursive call, then we may
3328 -- have an infinite recursion, so see if we can generate code to check
3329 -- for this possibility if storage checks are not suppressed.
3331 if Ekind (Spec_Id) = E_Procedure
3332 and then Has_Recursive_Call (Spec_Id)
3333 and then not Storage_Checks_Suppressed (Spec_Id)
3335 Detect_Infinite_Recursion (N, Spec_Id);
3338 -- Finally, if we are in Normalize_Scalars mode, then any scalar out
3339 -- parameters must be initialized to the appropriate default value.
3341 if Ekind (Spec_Id) = E_Procedure and then Normalize_Scalars then
3348 Formal := First_Formal (Spec_Id);
3350 while Present (Formal) loop
3351 Floc := Sloc (Formal);
3353 if Ekind (Formal) = E_Out_Parameter
3354 and then Is_Scalar_Type (Etype (Formal))
3357 Make_Assignment_Statement (Floc,
3358 Name => New_Occurrence_Of (Formal, Floc),
3360 Get_Simple_Init_Val (Etype (Formal), Floc));
3361 Prepend (Stm, Declarations (N));
3365 Next_Formal (Formal);
3370 -- Deal with thread body
3372 if Is_Thread_Body (Spec_Id) then
3376 -- If the subprogram does not have pending instantiations, then we
3377 -- must generate the subprogram descriptor now, since the code for
3378 -- the subprogram is complete, and this is our last chance. However
3379 -- if there are pending instantiations, then the code is not
3380 -- complete, and we will delay the generation.
3382 if Is_Subprogram (Spec_Id)
3383 and then not Delay_Subprogram_Descriptors (Spec_Id)
3385 Generate_Subprogram_Descriptor_For_Subprogram (N, Spec_Id);
3388 -- Set to encode entity names in package body before gigi is called
3390 Qualify_Entity_Names (N);
3391 end Expand_N_Subprogram_Body;
3393 -----------------------------------
3394 -- Expand_N_Subprogram_Body_Stub --
3395 -----------------------------------
3397 procedure Expand_N_Subprogram_Body_Stub (N : Node_Id) is
3399 if Present (Corresponding_Body (N)) then
3400 Expand_N_Subprogram_Body (
3401 Unit_Declaration_Node (Corresponding_Body (N)));
3403 end Expand_N_Subprogram_Body_Stub;
3405 -------------------------------------
3406 -- Expand_N_Subprogram_Declaration --
3407 -------------------------------------
3409 -- If the declaration appears within a protected body, it is a private
3410 -- operation of the protected type. We must create the corresponding
3411 -- protected subprogram an associated formals. For a normal protected
3412 -- operation, this is done when expanding the protected type declaration.
3414 procedure Expand_N_Subprogram_Declaration (N : Node_Id) is
3415 Loc : constant Source_Ptr := Sloc (N);
3416 Subp : constant Entity_Id := Defining_Entity (N);
3417 Scop : constant Entity_Id := Scope (Subp);
3418 Prot_Decl : Node_Id;
3420 Prot_Id : Entity_Id;
3423 -- Deal with case of protected subprogram
3425 if Is_List_Member (N)
3426 and then Present (Parent (List_Containing (N)))
3427 and then Nkind (Parent (List_Containing (N))) = N_Protected_Body
3428 and then Is_Protected_Type (Scop)
3430 if No (Protected_Body_Subprogram (Subp)) then
3432 Make_Subprogram_Declaration (Loc,
3434 Build_Protected_Sub_Specification
3435 (N, Scop, Unprotected => True));
3437 -- The protected subprogram is declared outside of the protected
3438 -- body. Given that the body has frozen all entities so far, we
3439 -- analyze the subprogram and perform freezing actions explicitly.
3440 -- If the body is a subunit, the insertion point is before the
3441 -- stub in the parent.
3443 Prot_Bod := Parent (List_Containing (N));
3445 if Nkind (Parent (Prot_Bod)) = N_Subunit then
3446 Prot_Bod := Corresponding_Stub (Parent (Prot_Bod));
3449 Insert_Before (Prot_Bod, Prot_Decl);
3450 Prot_Id := Defining_Unit_Name (Specification (Prot_Decl));
3452 New_Scope (Scope (Scop));
3453 Analyze (Prot_Decl);
3454 Create_Extra_Formals (Prot_Id);
3455 Set_Protected_Body_Subprogram (Subp, Prot_Id);
3459 end Expand_N_Subprogram_Declaration;
3461 ---------------------------------------
3462 -- Expand_Protected_Object_Reference --
3463 ---------------------------------------
3465 function Expand_Protected_Object_Reference
3470 Loc : constant Source_Ptr := Sloc (N);
3477 Rec := Make_Identifier (Loc, Name_uObject);
3478 Set_Etype (Rec, Corresponding_Record_Type (Scop));
3480 -- Find enclosing protected operation, and retrieve its first
3481 -- parameter, which denotes the enclosing protected object.
3482 -- If the enclosing operation is an entry, we are immediately
3483 -- within the protected body, and we can retrieve the object
3484 -- from the service entries procedure. A barrier function has
3485 -- has the same signature as an entry. A barrier function is
3486 -- compiled within the protected object, but unlike protected
3487 -- operations its never needs locks, so that its protected body
3488 -- subprogram points to itself.
3490 Proc := Current_Scope;
3492 while Present (Proc)
3493 and then Scope (Proc) /= Scop
3495 Proc := Scope (Proc);
3498 Corr := Protected_Body_Subprogram (Proc);
3502 -- Previous error left expansion incomplete.
3503 -- Nothing to do on this call.
3510 (First (Parameter_Specifications (Parent (Corr))));
3512 if Is_Subprogram (Proc)
3513 and then Proc /= Corr
3515 -- Protected function or procedure.
3517 Set_Entity (Rec, Param);
3519 -- Rec is a reference to an entity which will not be in scope
3520 -- when the call is reanalyzed, and needs no further analysis.
3525 -- Entry or barrier function for entry body.
3526 -- The first parameter of the entry body procedure is a
3527 -- pointer to the object. We create a local variable
3528 -- of the proper type, duplicating what is done to define
3529 -- _object later on.
3533 Obj_Ptr : constant Entity_Id := Make_Defining_Identifier (Loc,
3535 New_Internal_Name ('T'));
3539 Make_Full_Type_Declaration (Loc,
3540 Defining_Identifier => Obj_Ptr,
3542 Make_Access_To_Object_Definition (Loc,
3543 Subtype_Indication =>
3545 (Corresponding_Record_Type (Scop), Loc))));
3547 Insert_Actions (N, Decls);
3548 Insert_Actions (N, Freeze_Entity (Obj_Ptr, Sloc (N)));
3551 Make_Explicit_Dereference (Loc,
3552 Unchecked_Convert_To (Obj_Ptr,
3553 New_Occurrence_Of (Param, Loc)));
3555 -- Analyze new actual. Other actuals in calls are already
3556 -- analyzed and the list of actuals is not renalyzed after
3559 Set_Parent (Rec, N);
3565 end Expand_Protected_Object_Reference;
3567 --------------------------------------
3568 -- Expand_Protected_Subprogram_Call --
3569 --------------------------------------
3571 procedure Expand_Protected_Subprogram_Call
3579 -- If the protected object is not an enclosing scope, this is
3580 -- an inter-object function call. Inter-object procedure
3581 -- calls are expanded by Exp_Ch9.Build_Simple_Entry_Call.
3582 -- The call is intra-object only if the subprogram being
3583 -- called is in the protected body being compiled, and if the
3584 -- protected object in the call is statically the enclosing type.
3585 -- The object may be an component of some other data structure,
3586 -- in which case this must be handled as an inter-object call.
3588 if not In_Open_Scopes (Scop)
3589 or else not Is_Entity_Name (Name (N))
3591 if Nkind (Name (N)) = N_Selected_Component then
3592 Rec := Prefix (Name (N));
3595 pragma Assert (Nkind (Name (N)) = N_Indexed_Component);
3596 Rec := Prefix (Prefix (Name (N)));
3599 Build_Protected_Subprogram_Call (N,
3600 Name => New_Occurrence_Of (Subp, Sloc (N)),
3601 Rec => Convert_Concurrent (Rec, Etype (Rec)),
3605 Rec := Expand_Protected_Object_Reference (N, Scop);
3611 Build_Protected_Subprogram_Call (N,
3620 -- If it is a function call it can appear in elaboration code and
3621 -- the called entity must be frozen here.
3623 if Ekind (Subp) = E_Function then
3624 Freeze_Expression (Name (N));
3626 end Expand_Protected_Subprogram_Call;
3628 -----------------------
3629 -- Freeze_Subprogram --
3630 -----------------------
3632 procedure Freeze_Subprogram (N : Node_Id) is
3633 E : constant Entity_Id := Entity (N);
3636 -- When a primitive is frozen, enter its name in the corresponding
3637 -- dispatch table. If the DTC_Entity field is not set this is an
3638 -- overridden primitive that can be ignored. We suppress the
3639 -- initialization of the dispatch table entry when Java_VM because
3640 -- the dispatching mechanism is handled internally by the JVM.
3642 if Is_Dispatching_Operation (E)
3643 and then not Is_Abstract (E)
3644 and then Present (DTC_Entity (E))
3645 and then not Is_CPP_Class (Scope (DTC_Entity (E)))
3646 and then not Java_VM
3648 Check_Overriding_Operation (E);
3649 Insert_After (N, Fill_DT_Entry (Sloc (N), E));
3652 -- Mark functions that return by reference. Note that it cannot be
3653 -- part of the normal semantic analysis of the spec since the
3654 -- underlying returned type may not be known yet (for private types)
3657 Typ : constant Entity_Id := Etype (E);
3658 Utyp : constant Entity_Id := Underlying_Type (Typ);
3661 if Is_Return_By_Reference_Type (Typ) then
3662 Set_Returns_By_Ref (E);
3664 elsif Present (Utyp) and then Controlled_Type (Utyp) then
3665 Set_Returns_By_Ref (E);
3668 end Freeze_Subprogram;
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