1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, 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 3, 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 COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Aggr; use Exp_Aggr;
33 with Exp_Ch6; use Exp_Ch6;
34 with Exp_Ch7; use Exp_Ch7;
35 with Inline; use Inline;
36 with Itypes; use Itypes;
38 with Nlists; use Nlists;
39 with Nmake; use Nmake;
41 with Restrict; use Restrict;
42 with Rident; use Rident;
44 with Sem_Ch8; use Sem_Ch8;
45 with Sem_Eval; use Sem_Eval;
46 with Sem_Res; use Sem_Res;
47 with Sem_Type; use Sem_Type;
48 with Sem_Util; use Sem_Util;
49 with Snames; use Snames;
50 with Stand; use Stand;
51 with Stringt; use Stringt;
52 with Targparm; use Targparm;
53 with Tbuild; use Tbuild;
54 with Ttypes; use Ttypes;
55 with Uintp; use Uintp;
56 with Urealp; use Urealp;
57 with Validsw; use Validsw;
59 package body Exp_Util is
61 -----------------------
62 -- Local Subprograms --
63 -----------------------
65 function Build_Task_Array_Image
69 Dyn : Boolean := False) return Node_Id;
70 -- Build function to generate the image string for a task that is an
71 -- array component, concatenating the images of each index. To avoid
72 -- storage leaks, the string is built with successive slice assignments.
73 -- The flag Dyn indicates whether this is called for the initialization
74 -- procedure of an array of tasks, or for the name of a dynamically
75 -- created task that is assigned to an indexed component.
77 function Build_Task_Image_Function
81 Res : Entity_Id) return Node_Id;
82 -- Common processing for Task_Array_Image and Task_Record_Image.
83 -- Build function body that computes image.
85 procedure Build_Task_Image_Prefix
94 -- Common processing for Task_Array_Image and Task_Record_Image.
95 -- Create local variables and assign prefix of name to result string.
97 function Build_Task_Record_Image
100 Dyn : Boolean := False) return Node_Id;
101 -- Build function to generate the image string for a task that is a
102 -- record component. Concatenate name of variable with that of selector.
103 -- The flag Dyn indicates whether this is called for the initialization
104 -- procedure of record with task components, or for a dynamically
105 -- created task that is assigned to a selected component.
107 function Make_CW_Equivalent_Type
109 E : Node_Id) return Entity_Id;
110 -- T is a class-wide type entity, E is the initial expression node that
111 -- constrains T in case such as: " X: T := E" or "new T'(E)"
112 -- This function returns the entity of the Equivalent type and inserts
113 -- on the fly the necessary declaration such as:
115 -- type anon is record
116 -- _parent : Root_Type (T); constrained with E discriminants (if any)
117 -- Extension : String (1 .. expr to match size of E);
120 -- This record is compatible with any object of the class of T thanks
121 -- to the first field and has the same size as E thanks to the second.
123 function Make_Literal_Range
125 Literal_Typ : Entity_Id) return Node_Id;
126 -- Produce a Range node whose bounds are:
127 -- Low_Bound (Literal_Type) ..
128 -- Low_Bound (Literal_Type) + (Length (Literal_Typ) - 1)
129 -- this is used for expanding declarations like X : String := "sdfgdfg";
131 -- If the index type of the target array is not integer, we generate:
132 -- Low_Bound (Literal_Type) ..
134 -- (Literal_Type'Pos (Low_Bound (Literal_Type))
135 -- + (Length (Literal_Typ) -1))
137 function New_Class_Wide_Subtype
139 N : Node_Id) return Entity_Id;
140 -- Create an implicit subtype of CW_Typ attached to node N
142 ----------------------
143 -- Adjust_Condition --
144 ----------------------
146 procedure Adjust_Condition (N : Node_Id) is
153 Loc : constant Source_Ptr := Sloc (N);
154 T : constant Entity_Id := Etype (N);
158 -- For now, we simply ignore a call where the argument has no
159 -- type (probably case of unanalyzed condition), or has a type
160 -- that is not Boolean. This is because this is a pretty marginal
161 -- piece of functionality, and violations of these rules are
162 -- likely to be truly marginal (how much code uses Fortran Logical
163 -- as the barrier to a protected entry?) and we do not want to
164 -- blow up existing programs. We can change this to an assertion
165 -- after 3.12a is released ???
167 if No (T) or else not Is_Boolean_Type (T) then
171 -- Apply validity checking if needed
173 if Validity_Checks_On and Validity_Check_Tests then
177 -- Immediate return if standard boolean, the most common case,
178 -- where nothing needs to be done.
180 if Base_Type (T) = Standard_Boolean then
184 -- Case of zero/non-zero semantics or non-standard enumeration
185 -- representation. In each case, we rewrite the node as:
187 -- ityp!(N) /= False'Enum_Rep
189 -- where ityp is an integer type with large enough size to hold
190 -- any value of type T.
192 if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then
193 if Esize (T) <= Esize (Standard_Integer) then
194 Ti := Standard_Integer;
196 Ti := Standard_Long_Long_Integer;
201 Left_Opnd => Unchecked_Convert_To (Ti, N),
203 Make_Attribute_Reference (Loc,
204 Attribute_Name => Name_Enum_Rep,
206 New_Occurrence_Of (First_Literal (T), Loc))));
207 Analyze_And_Resolve (N, Standard_Boolean);
210 Rewrite (N, Convert_To (Standard_Boolean, N));
211 Analyze_And_Resolve (N, Standard_Boolean);
214 end Adjust_Condition;
216 ------------------------
217 -- Adjust_Result_Type --
218 ------------------------
220 procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is
222 -- Ignore call if current type is not Standard.Boolean
224 if Etype (N) /= Standard_Boolean then
228 -- If result is already of correct type, nothing to do. Note that
229 -- this will get the most common case where everything has a type
230 -- of Standard.Boolean.
232 if Base_Type (T) = Standard_Boolean then
237 KP : constant Node_Kind := Nkind (Parent (N));
240 -- If result is to be used as a Condition in the syntax, no need
241 -- to convert it back, since if it was changed to Standard.Boolean
242 -- using Adjust_Condition, that is just fine for this usage.
244 if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then
247 -- If result is an operand of another logical operation, no need
248 -- to reset its type, since Standard.Boolean is just fine, and
249 -- such operations always do Adjust_Condition on their operands.
251 elsif KP in N_Op_Boolean
252 or else KP = N_And_Then
253 or else KP = N_Or_Else
254 or else KP = N_Op_Not
258 -- Otherwise we perform a conversion from the current type,
259 -- which must be Standard.Boolean, to the desired type.
263 Rewrite (N, Convert_To (T, N));
264 Analyze_And_Resolve (N, T);
268 end Adjust_Result_Type;
270 --------------------------
271 -- Append_Freeze_Action --
272 --------------------------
274 procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is
278 Ensure_Freeze_Node (T);
279 Fnode := Freeze_Node (T);
281 if No (Actions (Fnode)) then
282 Set_Actions (Fnode, New_List);
285 Append (N, Actions (Fnode));
286 end Append_Freeze_Action;
288 ---------------------------
289 -- Append_Freeze_Actions --
290 ---------------------------
292 procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is
293 Fnode : constant Node_Id := Freeze_Node (T);
300 if No (Actions (Fnode)) then
301 Set_Actions (Fnode, L);
304 Append_List (L, Actions (Fnode));
308 end Append_Freeze_Actions;
310 ------------------------
311 -- Build_Runtime_Call --
312 ------------------------
314 function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is
316 -- If entity is not available, we can skip making the call (this avoids
317 -- junk duplicated error messages in a number of cases).
319 if not RTE_Available (RE) then
320 return Make_Null_Statement (Loc);
323 Make_Procedure_Call_Statement (Loc,
324 Name => New_Reference_To (RTE (RE), Loc));
326 end Build_Runtime_Call;
328 ----------------------------
329 -- Build_Task_Array_Image --
330 ----------------------------
332 -- This function generates the body for a function that constructs the
333 -- image string for a task that is an array component. The function is
334 -- local to the init proc for the array type, and is called for each one
335 -- of the components. The constructed image has the form of an indexed
336 -- component, whose prefix is the outer variable of the array type.
337 -- The n-dimensional array type has known indices Index, Index2...
338 -- Id_Ref is an indexed component form created by the enclosing init proc.
339 -- Its successive indices are Val1, Val2,.. which are the loop variables
340 -- in the loops that call the individual task init proc on each component.
342 -- The generated function has the following structure:
344 -- function F return String is
345 -- Pref : string renames Task_Name;
346 -- T1 : String := Index1'Image (Val1);
348 -- Tn : String := indexn'image (Valn);
349 -- Len : Integer := T1'Length + ... + Tn'Length + n + 1;
350 -- -- Len includes commas and the end parentheses.
351 -- Res : String (1..Len);
352 -- Pos : Integer := Pref'Length;
355 -- Res (1 .. Pos) := Pref;
359 -- Res (Pos .. Pos + T1'Length - 1) := T1;
360 -- Pos := Pos + T1'Length;
364 -- Res (Pos .. Pos + Tn'Length - 1) := Tn;
370 -- Needless to say, multidimensional arrays of tasks are rare enough
371 -- that the bulkiness of this code is not really a concern.
373 function Build_Task_Array_Image
377 Dyn : Boolean := False) return Node_Id
379 Dims : constant Nat := Number_Dimensions (A_Type);
380 -- Number of dimensions for array of tasks
382 Temps : array (1 .. Dims) of Entity_Id;
383 -- Array of temporaries to hold string for each index
389 -- Total length of generated name
392 -- Running index for substring assignments
395 -- Name of enclosing variable, prefix of resulting name
398 -- String to hold result
401 -- Value of successive indices
404 -- Expression to compute total size of string
407 -- Entity for name at one index position
409 Decls : constant List_Id := New_List;
410 Stats : constant List_Id := New_List;
413 Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
415 -- For a dynamic task, the name comes from the target variable.
416 -- For a static one it is a formal of the enclosing init proc.
419 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
421 Make_Object_Declaration (Loc,
422 Defining_Identifier => Pref,
423 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
425 Make_String_Literal (Loc,
426 Strval => String_From_Name_Buffer)));
430 Make_Object_Renaming_Declaration (Loc,
431 Defining_Identifier => Pref,
432 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
433 Name => Make_Identifier (Loc, Name_uTask_Name)));
436 Indx := First_Index (A_Type);
437 Val := First (Expressions (Id_Ref));
439 for J in 1 .. Dims loop
440 T := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
444 Make_Object_Declaration (Loc,
445 Defining_Identifier => T,
446 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
448 Make_Attribute_Reference (Loc,
449 Attribute_Name => Name_Image,
451 New_Occurrence_Of (Etype (Indx), Loc),
452 Expressions => New_List (
453 New_Copy_Tree (Val)))));
459 Sum := Make_Integer_Literal (Loc, Dims + 1);
465 Make_Attribute_Reference (Loc,
466 Attribute_Name => Name_Length,
468 New_Occurrence_Of (Pref, Loc),
469 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
471 for J in 1 .. Dims loop
476 Make_Attribute_Reference (Loc,
477 Attribute_Name => Name_Length,
479 New_Occurrence_Of (Temps (J), Loc),
480 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
483 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
485 Set_Character_Literal_Name (Char_Code (Character'Pos ('(')));
488 Make_Assignment_Statement (Loc,
489 Name => Make_Indexed_Component (Loc,
490 Prefix => New_Occurrence_Of (Res, Loc),
491 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
493 Make_Character_Literal (Loc,
495 Char_Literal_Value =>
496 UI_From_Int (Character'Pos ('(')))));
499 Make_Assignment_Statement (Loc,
500 Name => New_Occurrence_Of (Pos, Loc),
503 Left_Opnd => New_Occurrence_Of (Pos, Loc),
504 Right_Opnd => Make_Integer_Literal (Loc, 1))));
506 for J in 1 .. Dims loop
509 Make_Assignment_Statement (Loc,
510 Name => Make_Slice (Loc,
511 Prefix => New_Occurrence_Of (Res, Loc),
514 Low_Bound => New_Occurrence_Of (Pos, Loc),
515 High_Bound => Make_Op_Subtract (Loc,
518 Left_Opnd => New_Occurrence_Of (Pos, Loc),
520 Make_Attribute_Reference (Loc,
521 Attribute_Name => Name_Length,
523 New_Occurrence_Of (Temps (J), Loc),
525 New_List (Make_Integer_Literal (Loc, 1)))),
526 Right_Opnd => Make_Integer_Literal (Loc, 1)))),
528 Expression => New_Occurrence_Of (Temps (J), Loc)));
532 Make_Assignment_Statement (Loc,
533 Name => New_Occurrence_Of (Pos, Loc),
536 Left_Opnd => New_Occurrence_Of (Pos, Loc),
538 Make_Attribute_Reference (Loc,
539 Attribute_Name => Name_Length,
540 Prefix => New_Occurrence_Of (Temps (J), Loc),
542 New_List (Make_Integer_Literal (Loc, 1))))));
544 Set_Character_Literal_Name (Char_Code (Character'Pos (',')));
547 Make_Assignment_Statement (Loc,
548 Name => Make_Indexed_Component (Loc,
549 Prefix => New_Occurrence_Of (Res, Loc),
550 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
552 Make_Character_Literal (Loc,
554 Char_Literal_Value =>
555 UI_From_Int (Character'Pos (',')))));
558 Make_Assignment_Statement (Loc,
559 Name => New_Occurrence_Of (Pos, Loc),
562 Left_Opnd => New_Occurrence_Of (Pos, Loc),
563 Right_Opnd => Make_Integer_Literal (Loc, 1))));
567 Set_Character_Literal_Name (Char_Code (Character'Pos (')')));
570 Make_Assignment_Statement (Loc,
571 Name => Make_Indexed_Component (Loc,
572 Prefix => New_Occurrence_Of (Res, Loc),
573 Expressions => New_List (New_Occurrence_Of (Len, Loc))),
575 Make_Character_Literal (Loc,
577 Char_Literal_Value =>
578 UI_From_Int (Character'Pos (')')))));
579 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
580 end Build_Task_Array_Image;
582 ----------------------------
583 -- Build_Task_Image_Decls --
584 ----------------------------
586 function Build_Task_Image_Decls
590 In_Init_Proc : Boolean := False) return List_Id
592 Decls : constant List_Id := New_List;
593 T_Id : Entity_Id := Empty;
595 Expr : Node_Id := Empty;
596 Fun : Node_Id := Empty;
597 Is_Dyn : constant Boolean :=
598 Nkind (Parent (Id_Ref)) = N_Assignment_Statement
600 Nkind (Expression (Parent (Id_Ref))) = N_Allocator;
603 -- If Discard_Names or No_Implicit_Heap_Allocations are in effect,
604 -- generate a dummy declaration only.
606 if Restriction_Active (No_Implicit_Heap_Allocations)
607 or else Global_Discard_Names
609 T_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
614 Make_Object_Declaration (Loc,
615 Defining_Identifier => T_Id,
616 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
618 Make_String_Literal (Loc,
619 Strval => String_From_Name_Buffer)));
622 if Nkind (Id_Ref) = N_Identifier
623 or else Nkind (Id_Ref) = N_Defining_Identifier
625 -- For a simple variable, the image of the task is built from
626 -- the name of the variable. To avoid possible conflict with
627 -- the anonymous type created for a single protected object,
628 -- add a numeric suffix.
631 Make_Defining_Identifier (Loc,
632 New_External_Name (Chars (Id_Ref), 'T', 1));
634 Get_Name_String (Chars (Id_Ref));
637 Make_String_Literal (Loc,
638 Strval => String_From_Name_Buffer);
640 elsif Nkind (Id_Ref) = N_Selected_Component then
642 Make_Defining_Identifier (Loc,
643 New_External_Name (Chars (Selector_Name (Id_Ref)), 'T'));
644 Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn);
646 elsif Nkind (Id_Ref) = N_Indexed_Component then
648 Make_Defining_Identifier (Loc,
649 New_External_Name (Chars (A_Type), 'N'));
651 Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn);
655 if Present (Fun) then
657 Expr := Make_Function_Call (Loc,
658 Name => New_Occurrence_Of (Defining_Entity (Fun), Loc));
660 if not In_Init_Proc and then VM_Target = No_VM then
661 Set_Uses_Sec_Stack (Defining_Entity (Fun));
665 Decl := Make_Object_Declaration (Loc,
666 Defining_Identifier => T_Id,
667 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
668 Constant_Present => True,
671 Append (Decl, Decls);
673 end Build_Task_Image_Decls;
675 -------------------------------
676 -- Build_Task_Image_Function --
677 -------------------------------
679 function Build_Task_Image_Function
683 Res : Entity_Id) return Node_Id
689 Make_Simple_Return_Statement (Loc,
690 Expression => New_Occurrence_Of (Res, Loc)));
692 Spec := Make_Function_Specification (Loc,
693 Defining_Unit_Name =>
694 Make_Defining_Identifier (Loc, New_Internal_Name ('F')),
695 Result_Definition => New_Occurrence_Of (Standard_String, Loc));
697 -- Calls to 'Image use the secondary stack, which must be cleaned
698 -- up after the task name is built.
700 return Make_Subprogram_Body (Loc,
701 Specification => Spec,
702 Declarations => Decls,
703 Handled_Statement_Sequence =>
704 Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats));
705 end Build_Task_Image_Function;
707 -----------------------------
708 -- Build_Task_Image_Prefix --
709 -----------------------------
711 procedure Build_Task_Image_Prefix
722 Len := Make_Defining_Identifier (Loc, New_Internal_Name ('L'));
725 Make_Object_Declaration (Loc,
726 Defining_Identifier => Len,
727 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
730 Res := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
733 Make_Object_Declaration (Loc,
734 Defining_Identifier => Res,
736 Make_Subtype_Indication (Loc,
737 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
739 Make_Index_Or_Discriminant_Constraint (Loc,
743 Low_Bound => Make_Integer_Literal (Loc, 1),
744 High_Bound => New_Occurrence_Of (Len, Loc)))))));
746 Pos := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
749 Make_Object_Declaration (Loc,
750 Defining_Identifier => Pos,
751 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc)));
753 -- Pos := Prefix'Length;
756 Make_Assignment_Statement (Loc,
757 Name => New_Occurrence_Of (Pos, Loc),
759 Make_Attribute_Reference (Loc,
760 Attribute_Name => Name_Length,
761 Prefix => New_Occurrence_Of (Prefix, Loc),
763 New_List (Make_Integer_Literal (Loc, 1)))));
765 -- Res (1 .. Pos) := Prefix;
768 Make_Assignment_Statement (Loc,
769 Name => Make_Slice (Loc,
770 Prefix => New_Occurrence_Of (Res, Loc),
773 Low_Bound => Make_Integer_Literal (Loc, 1),
774 High_Bound => New_Occurrence_Of (Pos, Loc))),
776 Expression => New_Occurrence_Of (Prefix, Loc)));
779 Make_Assignment_Statement (Loc,
780 Name => New_Occurrence_Of (Pos, Loc),
783 Left_Opnd => New_Occurrence_Of (Pos, Loc),
784 Right_Opnd => Make_Integer_Literal (Loc, 1))));
785 end Build_Task_Image_Prefix;
787 -----------------------------
788 -- Build_Task_Record_Image --
789 -----------------------------
791 function Build_Task_Record_Image
794 Dyn : Boolean := False) return Node_Id
797 -- Total length of generated name
803 -- String to hold result
806 -- Name of enclosing variable, prefix of resulting name
809 -- Expression to compute total size of string
812 -- Entity for selector name
814 Decls : constant List_Id := New_List;
815 Stats : constant List_Id := New_List;
818 Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
820 -- For a dynamic task, the name comes from the target variable.
821 -- For a static one it is a formal of the enclosing init proc.
824 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
826 Make_Object_Declaration (Loc,
827 Defining_Identifier => Pref,
828 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
830 Make_String_Literal (Loc,
831 Strval => String_From_Name_Buffer)));
835 Make_Object_Renaming_Declaration (Loc,
836 Defining_Identifier => Pref,
837 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
838 Name => Make_Identifier (Loc, Name_uTask_Name)));
841 Sel := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
843 Get_Name_String (Chars (Selector_Name (Id_Ref)));
846 Make_Object_Declaration (Loc,
847 Defining_Identifier => Sel,
848 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
850 Make_String_Literal (Loc,
851 Strval => String_From_Name_Buffer)));
853 Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1));
859 Make_Attribute_Reference (Loc,
860 Attribute_Name => Name_Length,
862 New_Occurrence_Of (Pref, Loc),
863 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
865 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
867 Set_Character_Literal_Name (Char_Code (Character'Pos ('.')));
872 Make_Assignment_Statement (Loc,
873 Name => Make_Indexed_Component (Loc,
874 Prefix => New_Occurrence_Of (Res, Loc),
875 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
877 Make_Character_Literal (Loc,
879 Char_Literal_Value =>
880 UI_From_Int (Character'Pos ('.')))));
883 Make_Assignment_Statement (Loc,
884 Name => New_Occurrence_Of (Pos, Loc),
887 Left_Opnd => New_Occurrence_Of (Pos, Loc),
888 Right_Opnd => Make_Integer_Literal (Loc, 1))));
890 -- Res (Pos .. Len) := Selector;
893 Make_Assignment_Statement (Loc,
894 Name => Make_Slice (Loc,
895 Prefix => New_Occurrence_Of (Res, Loc),
898 Low_Bound => New_Occurrence_Of (Pos, Loc),
899 High_Bound => New_Occurrence_Of (Len, Loc))),
900 Expression => New_Occurrence_Of (Sel, Loc)));
902 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
903 end Build_Task_Record_Image;
905 ----------------------------------
906 -- Component_May_Be_Bit_Aligned --
907 ----------------------------------
909 function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is
911 -- If no component clause, then everything is fine, since the
912 -- back end never bit-misaligns by default, even if there is
913 -- a pragma Packed for the record.
915 if No (Component_Clause (Comp)) then
919 -- It is only array and record types that cause trouble
921 if not Is_Record_Type (Etype (Comp))
922 and then not Is_Array_Type (Etype (Comp))
926 -- If we know that we have a small (64 bits or less) record
927 -- or bit-packed array, then everything is fine, since the
928 -- back end can handle these cases correctly.
930 elsif Esize (Comp) <= 64
931 and then (Is_Record_Type (Etype (Comp))
932 or else Is_Bit_Packed_Array (Etype (Comp)))
936 -- Otherwise if the component is not byte aligned, we
937 -- know we have the nasty unaligned case.
939 elsif Normalized_First_Bit (Comp) /= Uint_0
940 or else Esize (Comp) mod System_Storage_Unit /= Uint_0
944 -- If we are large and byte aligned, then OK at this level
949 end Component_May_Be_Bit_Aligned;
951 -------------------------------
952 -- Convert_To_Actual_Subtype --
953 -------------------------------
955 procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is
959 Act_ST := Get_Actual_Subtype (Exp);
961 if Act_ST = Etype (Exp) then
966 Convert_To (Act_ST, Relocate_Node (Exp)));
967 Analyze_And_Resolve (Exp, Act_ST);
969 end Convert_To_Actual_Subtype;
971 -----------------------------------
972 -- Current_Sem_Unit_Declarations --
973 -----------------------------------
975 function Current_Sem_Unit_Declarations return List_Id is
976 U : Node_Id := Unit (Cunit (Current_Sem_Unit));
980 -- If the current unit is a package body, locate the visible
981 -- declarations of the package spec.
983 if Nkind (U) = N_Package_Body then
984 U := Unit (Library_Unit (Cunit (Current_Sem_Unit)));
987 if Nkind (U) = N_Package_Declaration then
988 U := Specification (U);
989 Decls := Visible_Declarations (U);
993 Set_Visible_Declarations (U, Decls);
997 Decls := Declarations (U);
1001 Set_Declarations (U, Decls);
1006 end Current_Sem_Unit_Declarations;
1008 -----------------------
1009 -- Duplicate_Subexpr --
1010 -----------------------
1012 function Duplicate_Subexpr
1014 Name_Req : Boolean := False) return Node_Id
1017 Remove_Side_Effects (Exp, Name_Req);
1018 return New_Copy_Tree (Exp);
1019 end Duplicate_Subexpr;
1021 ---------------------------------
1022 -- Duplicate_Subexpr_No_Checks --
1023 ---------------------------------
1025 function Duplicate_Subexpr_No_Checks
1027 Name_Req : Boolean := False) return Node_Id
1032 Remove_Side_Effects (Exp, Name_Req);
1033 New_Exp := New_Copy_Tree (Exp);
1034 Remove_Checks (New_Exp);
1036 end Duplicate_Subexpr_No_Checks;
1038 -----------------------------------
1039 -- Duplicate_Subexpr_Move_Checks --
1040 -----------------------------------
1042 function Duplicate_Subexpr_Move_Checks
1044 Name_Req : Boolean := False) return Node_Id
1049 Remove_Side_Effects (Exp, Name_Req);
1050 New_Exp := New_Copy_Tree (Exp);
1051 Remove_Checks (Exp);
1053 end Duplicate_Subexpr_Move_Checks;
1055 --------------------
1056 -- Ensure_Defined --
1057 --------------------
1059 procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is
1063 -- An itype reference must only be created if this is a local
1064 -- itype, so that gigi can elaborate it on the proper objstack.
1067 and then Scope (Typ) = Current_Scope
1069 IR := Make_Itype_Reference (Sloc (N));
1070 Set_Itype (IR, Typ);
1071 Insert_Action (N, IR);
1075 ---------------------
1076 -- Evolve_And_Then --
1077 ---------------------
1079 procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is
1085 Make_And_Then (Sloc (Cond1),
1087 Right_Opnd => Cond1);
1089 end Evolve_And_Then;
1091 --------------------
1092 -- Evolve_Or_Else --
1093 --------------------
1095 procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is
1101 Make_Or_Else (Sloc (Cond1),
1103 Right_Opnd => Cond1);
1107 ------------------------------
1108 -- Expand_Subtype_From_Expr --
1109 ------------------------------
1111 -- This function is applicable for both static and dynamic allocation of
1112 -- objects which are constrained by an initial expression. Basically it
1113 -- transforms an unconstrained subtype indication into a constrained one.
1114 -- The expression may also be transformed in certain cases in order to
1115 -- avoid multiple evaluation. In the static allocation case, the general
1120 -- is transformed into
1122 -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr;
1124 -- Here are the main cases :
1126 -- <if Expr is a Slice>
1127 -- Val : T ([Index_Subtype (Expr)]) := Expr;
1129 -- <elsif Expr is a String Literal>
1130 -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
1132 -- <elsif Expr is Constrained>
1133 -- subtype T is Type_Of_Expr
1136 -- <elsif Expr is an entity_name>
1137 -- Val : T (constraints taken from Expr) := Expr;
1140 -- type Axxx is access all T;
1141 -- Rval : Axxx := Expr'ref;
1142 -- Val : T (constraints taken from Rval) := Rval.all;
1144 -- ??? note: when the Expression is allocated in the secondary stack
1145 -- we could use it directly instead of copying it by declaring
1146 -- Val : T (...) renames Rval.all
1148 procedure Expand_Subtype_From_Expr
1150 Unc_Type : Entity_Id;
1151 Subtype_Indic : Node_Id;
1154 Loc : constant Source_Ptr := Sloc (N);
1155 Exp_Typ : constant Entity_Id := Etype (Exp);
1159 -- In general we cannot build the subtype if expansion is disabled,
1160 -- because internal entities may not have been defined. However, to
1161 -- avoid some cascaded errors, we try to continue when the expression
1162 -- is an array (or string), because it is safe to compute the bounds.
1163 -- It is in fact required to do so even in a generic context, because
1164 -- there may be constants that depend on bounds of string literal.
1166 if not Expander_Active
1167 and then (No (Etype (Exp))
1168 or else Base_Type (Etype (Exp)) /= Standard_String)
1173 if Nkind (Exp) = N_Slice then
1175 Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ));
1178 Rewrite (Subtype_Indic,
1179 Make_Subtype_Indication (Loc,
1180 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1182 Make_Index_Or_Discriminant_Constraint (Loc,
1183 Constraints => New_List
1184 (New_Reference_To (Slice_Type, Loc)))));
1186 -- This subtype indication may be used later for contraint checks
1187 -- we better make sure that if a variable was used as a bound of
1188 -- of the original slice, its value is frozen.
1190 Force_Evaluation (Low_Bound (Scalar_Range (Slice_Type)));
1191 Force_Evaluation (High_Bound (Scalar_Range (Slice_Type)));
1194 elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then
1195 Rewrite (Subtype_Indic,
1196 Make_Subtype_Indication (Loc,
1197 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1199 Make_Index_Or_Discriminant_Constraint (Loc,
1200 Constraints => New_List (
1201 Make_Literal_Range (Loc,
1202 Literal_Typ => Exp_Typ)))));
1204 elsif Is_Constrained (Exp_Typ)
1205 and then not Is_Class_Wide_Type (Unc_Type)
1207 if Is_Itype (Exp_Typ) then
1209 -- Within an initialization procedure, a selected component
1210 -- denotes a component of the enclosing record, and it appears
1211 -- as an actual in a call to its own initialization procedure.
1212 -- If this component depends on the outer discriminant, we must
1213 -- generate the proper actual subtype for it.
1215 if Nkind (Exp) = N_Selected_Component
1216 and then Within_Init_Proc
1219 Decl : constant Node_Id :=
1220 Build_Actual_Subtype_Of_Component (Exp_Typ, Exp);
1222 if Present (Decl) then
1223 Insert_Action (N, Decl);
1224 T := Defining_Identifier (Decl);
1230 -- No need to generate a new one (new what???)
1238 Make_Defining_Identifier (Loc,
1239 Chars => New_Internal_Name ('T'));
1242 Make_Subtype_Declaration (Loc,
1243 Defining_Identifier => T,
1244 Subtype_Indication => New_Reference_To (Exp_Typ, Loc)));
1246 -- This type is marked as an itype even though it has an
1247 -- explicit declaration because otherwise it can be marked
1248 -- with Is_Generic_Actual_Type and generate spurious errors.
1249 -- (see sem_ch8.Analyze_Package_Renaming and sem_type.covers)
1252 Set_Associated_Node_For_Itype (T, Exp);
1255 Rewrite (Subtype_Indic, New_Reference_To (T, Loc));
1257 -- nothing needs to be done for private types with unknown discriminants
1258 -- if the underlying type is not an unconstrained composite type.
1260 elsif Is_Private_Type (Unc_Type)
1261 and then Has_Unknown_Discriminants (Unc_Type)
1262 and then (not Is_Composite_Type (Underlying_Type (Unc_Type))
1263 or else Is_Constrained (Underlying_Type (Unc_Type)))
1267 -- Nothing to be done for derived types with unknown discriminants if
1268 -- the parent type also has unknown discriminants.
1270 elsif Is_Record_Type (Unc_Type)
1271 and then not Is_Class_Wide_Type (Unc_Type)
1272 and then Has_Unknown_Discriminants (Unc_Type)
1273 and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type))
1277 -- In Ada95, Nothing to be done if the type of the expression is
1278 -- limited, because in this case the expression cannot be copied,
1279 -- and its use can only be by reference.
1281 -- In Ada2005, the context can be an object declaration whose expression
1282 -- is a function that returns in place. If the nominal subtype has
1283 -- unknown discriminants, the call still provides constraints on the
1284 -- object, and we have to create an actual subtype from it.
1286 -- If the type is class-wide, the expression is dynamically tagged and
1287 -- we do not create an actual subtype either. Ditto for an interface.
1289 elsif Is_Limited_Type (Exp_Typ)
1291 (Is_Class_Wide_Type (Exp_Typ)
1292 or else Is_Interface (Exp_Typ)
1293 or else not Has_Unknown_Discriminants (Exp_Typ)
1294 or else not Is_Composite_Type (Unc_Type))
1298 -- For limited interfaces, nothing to be done
1300 -- This branch may be redundant once the limited interface issue is
1303 elsif Is_Interface (Exp_Typ)
1304 and then Is_Limited_Interface (Exp_Typ)
1308 -- For limited objects initialized with build in place function calls,
1309 -- nothing to be done; otherwise we prematurely introduce an N_Reference
1310 -- node in the expression initializing the object, which breaks the
1311 -- circuitry that detects and adds the additional arguments to the
1314 elsif Is_Build_In_Place_Function_Call (Exp) then
1318 Remove_Side_Effects (Exp);
1319 Rewrite (Subtype_Indic,
1320 Make_Subtype_From_Expr (Exp, Unc_Type));
1322 end Expand_Subtype_From_Expr;
1324 ------------------------
1325 -- Find_Interface_ADT --
1326 ------------------------
1328 function Find_Interface_ADT
1330 Iface : Entity_Id) return Elmt_Id
1333 Found : Boolean := False;
1334 Typ : Entity_Id := T;
1336 procedure Find_Secondary_Table (Typ : Entity_Id);
1337 -- Internal subprogram used to recursively climb to the ancestors
1339 --------------------------
1340 -- Find_Secondary_Table --
1341 --------------------------
1343 procedure Find_Secondary_Table (Typ : Entity_Id) is
1348 pragma Assert (Typ /= Iface);
1350 -- Climb to the ancestor (if any) handling synchronized interface
1351 -- derivations and private types
1353 if Is_Concurrent_Record_Type (Typ) then
1355 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1358 if Is_Non_Empty_List (Iface_List) then
1359 Find_Secondary_Table (Etype (First (Iface_List)));
1363 elsif Present (Full_View (Etype (Typ))) then
1364 if Full_View (Etype (Typ)) /= Typ then
1365 Find_Secondary_Table (Full_View (Etype (Typ)));
1368 elsif Etype (Typ) /= Typ then
1369 Find_Secondary_Table (Etype (Typ));
1372 -- Traverse the list of interfaces implemented by the type
1375 and then Present (Abstract_Interfaces (Typ))
1376 and then not Is_Empty_Elmt_List (Abstract_Interfaces (Typ))
1378 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1379 while Present (AI_Elmt) loop
1380 AI := Node (AI_Elmt);
1382 if AI = Iface or else Is_Ancestor (Iface, AI) then
1389 Next_Elmt (AI_Elmt);
1392 end Find_Secondary_Table;
1394 -- Start of processing for Find_Interface_ADT
1397 pragma Assert (Is_Interface (Iface));
1399 -- Handle private types
1401 if Has_Private_Declaration (Typ)
1402 and then Present (Full_View (Typ))
1404 Typ := Full_View (Typ);
1407 -- Handle access types
1409 if Is_Access_Type (Typ) then
1410 Typ := Directly_Designated_Type (Typ);
1413 -- Handle task and protected types implementing interfaces
1415 if Is_Concurrent_Type (Typ) then
1416 Typ := Corresponding_Record_Type (Typ);
1420 (not Is_Class_Wide_Type (Typ)
1421 and then Ekind (Typ) /= E_Incomplete_Type);
1423 ADT := Next_Elmt (First_Elmt (Access_Disp_Table (Typ)));
1424 pragma Assert (Present (Node (ADT)));
1425 Find_Secondary_Table (Typ);
1426 pragma Assert (Found);
1428 end Find_Interface_ADT;
1430 ------------------------
1431 -- Find_Interface_Tag --
1432 ------------------------
1434 function Find_Interface_Tag
1436 Iface : Entity_Id) return Entity_Id
1439 Found : Boolean := False;
1440 Typ : Entity_Id := T;
1442 Is_Primary_Tag : Boolean := False;
1444 Is_Sync_Typ : Boolean := False;
1445 -- In case of non concurrent-record-types each parent-type has the
1446 -- tags associated with the interface types that are not implemented
1447 -- by the ancestors; concurrent-record-types have their whole list of
1448 -- interface tags (and this case requires some special management).
1450 procedure Find_Tag (Typ : Entity_Id);
1451 -- Internal subprogram used to recursively climb to the ancestors
1457 procedure Find_Tag (Typ : Entity_Id) is
1462 -- Check if the interface is an immediate ancestor of the type and
1463 -- therefore shares the main tag.
1467 Is_Primary_Tag := True;
1470 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1471 AI_Tag := First_Tag_Component (Typ);
1478 -- Handle synchronized interface derivations
1480 if Is_Concurrent_Record_Type (Typ) then
1482 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1484 if Is_Non_Empty_List (Iface_List) then
1485 Find_Tag (Etype (First (Iface_List)));
1489 -- Climb to the root type handling private types
1491 elsif Present (Full_View (Etype (Typ))) then
1492 if Full_View (Etype (Typ)) /= Typ then
1493 Find_Tag (Full_View (Etype (Typ)));
1496 elsif Etype (Typ) /= Typ then
1497 Find_Tag (Etype (Typ));
1500 -- Traverse the list of interfaces implemented by the type
1503 and then Present (Abstract_Interfaces (Typ))
1504 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1506 -- Skip the tag associated with the primary table
1508 if not Is_Sync_Typ then
1510 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1511 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1512 pragma Assert (Present (AI_Tag));
1515 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1516 while Present (AI_Elmt) loop
1517 AI := Node (AI_Elmt);
1519 if AI = Iface or else Is_Ancestor (Iface, AI) then
1524 AI_Tag := Next_Tag_Component (AI_Tag);
1525 Next_Elmt (AI_Elmt);
1530 -- Start of processing for Find_Interface_Tag
1533 pragma Assert (Is_Interface (Iface));
1535 -- Handle private types
1537 if Has_Private_Declaration (Typ)
1538 and then Present (Full_View (Typ))
1540 Typ := Full_View (Typ);
1543 -- Handle access types
1545 if Is_Access_Type (Typ) then
1546 Typ := Directly_Designated_Type (Typ);
1549 -- Handle task and protected types implementing interfaces
1551 if Is_Concurrent_Type (Typ) then
1552 Typ := Corresponding_Record_Type (Typ);
1555 if Is_Class_Wide_Type (Typ) then
1559 -- Handle entities from the limited view
1561 if Ekind (Typ) = E_Incomplete_Type then
1562 pragma Assert (Present (Non_Limited_View (Typ)));
1563 Typ := Non_Limited_View (Typ);
1566 if not Is_Concurrent_Record_Type (Typ) then
1568 pragma Assert (Found);
1571 -- Concurrent record types
1574 Is_Sync_Typ := True;
1575 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1577 pragma Assert (Found);
1579 if Is_Primary_Tag then
1580 return First_Tag_Component (Typ);
1585 end Find_Interface_Tag;
1587 --------------------
1588 -- Find_Interface --
1589 --------------------
1591 function Find_Interface
1593 Comp : Entity_Id) return Entity_Id
1596 Found : Boolean := False;
1598 Typ : Entity_Id := T;
1600 Is_Sync_Typ : Boolean := False;
1601 -- In case of non concurrent-record-types each parent-type has the
1602 -- tags associated with the interface types that are not implemented
1603 -- by the ancestors; concurrent-record-types have their whole list of
1604 -- interface tags (and this case requires some special management).
1606 procedure Find_Iface (Typ : Entity_Id);
1607 -- Internal subprogram used to recursively climb to the ancestors
1613 procedure Find_Iface (Typ : Entity_Id) is
1617 -- Climb to the root type
1619 -- Handle sychronized interface derivations
1621 if Is_Concurrent_Record_Type (Typ) then
1623 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1625 if Is_Non_Empty_List (Iface_List) then
1626 Find_Iface (Etype (First (Iface_List)));
1630 -- Handle the common case
1632 elsif Etype (Typ) /= Typ then
1633 pragma Assert (not Present (Full_View (Etype (Typ))));
1634 Find_Iface (Etype (Typ));
1637 -- Traverse the list of interfaces implemented by the type
1640 and then Present (Abstract_Interfaces (Typ))
1641 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1643 -- Skip the tag associated with the primary table
1645 if not Is_Sync_Typ then
1647 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1648 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1649 pragma Assert (Present (AI_Tag));
1652 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1653 while Present (AI_Elmt) loop
1654 if AI_Tag = Comp then
1655 Iface := Node (AI_Elmt);
1660 AI_Tag := Next_Tag_Component (AI_Tag);
1661 Next_Elmt (AI_Elmt);
1666 -- Start of processing for Find_Interface
1669 -- Handle private types
1671 if Has_Private_Declaration (Typ)
1672 and then Present (Full_View (Typ))
1674 Typ := Full_View (Typ);
1677 -- Handle access types
1679 if Is_Access_Type (Typ) then
1680 Typ := Directly_Designated_Type (Typ);
1683 -- Handle task and protected types implementing interfaces
1685 if Is_Concurrent_Type (Typ) then
1686 Typ := Corresponding_Record_Type (Typ);
1689 if Is_Class_Wide_Type (Typ) then
1693 -- Handle entities from the limited view
1695 if Ekind (Typ) = E_Incomplete_Type then
1696 pragma Assert (Present (Non_Limited_View (Typ)));
1697 Typ := Non_Limited_View (Typ);
1700 if Is_Concurrent_Record_Type (Typ) then
1701 Is_Sync_Typ := True;
1702 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1706 pragma Assert (Found);
1714 function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is
1716 Typ : Entity_Id := T;
1720 if Is_Class_Wide_Type (Typ) then
1721 Typ := Root_Type (Typ);
1724 Typ := Underlying_Type (Typ);
1726 -- Loop through primitive operations
1728 Prim := First_Elmt (Primitive_Operations (Typ));
1729 while Present (Prim) loop
1732 -- We can retrieve primitive operations by name if it is an internal
1733 -- name. For equality we must check that both of its operands have
1734 -- the same type, to avoid confusion with user-defined equalities
1735 -- than may have a non-symmetric signature.
1737 exit when Chars (Op) = Name
1740 or else Etype (First_Entity (Op)) = Etype (Last_Entity (Op)));
1743 pragma Assert (Present (Prim));
1753 function Find_Prim_Op
1755 Name : TSS_Name_Type) return Entity_Id
1758 Typ : Entity_Id := T;
1761 if Is_Class_Wide_Type (Typ) then
1762 Typ := Root_Type (Typ);
1765 Typ := Underlying_Type (Typ);
1767 Prim := First_Elmt (Primitive_Operations (Typ));
1768 while not Is_TSS (Node (Prim), Name) loop
1770 pragma Assert (Present (Prim));
1776 ----------------------
1777 -- Force_Evaluation --
1778 ----------------------
1780 procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is
1782 Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True);
1783 end Force_Evaluation;
1785 ------------------------
1786 -- Generate_Poll_Call --
1787 ------------------------
1789 procedure Generate_Poll_Call (N : Node_Id) is
1791 -- No poll call if polling not active
1793 if not Polling_Required then
1796 -- Otherwise generate require poll call
1799 Insert_Before_And_Analyze (N,
1800 Make_Procedure_Call_Statement (Sloc (N),
1801 Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N))));
1803 end Generate_Poll_Call;
1805 ---------------------------------
1806 -- Get_Current_Value_Condition --
1807 ---------------------------------
1809 -- Note: the implementation of this procedure is very closely tied to the
1810 -- implementation of Set_Current_Value_Condition. In the Get procedure, we
1811 -- interpret Current_Value fields set by the Set procedure, so the two
1812 -- procedures need to be closely coordinated.
1814 procedure Get_Current_Value_Condition
1819 Loc : constant Source_Ptr := Sloc (Var);
1820 Ent : constant Entity_Id := Entity (Var);
1822 procedure Process_Current_Value_Condition
1825 -- N is an expression which holds either True (S = True) or False (S =
1826 -- False) in the condition. This procedure digs out the expression and
1827 -- if it refers to Ent, sets Op and Val appropriately.
1829 -------------------------------------
1830 -- Process_Current_Value_Condition --
1831 -------------------------------------
1833 procedure Process_Current_Value_Condition
1844 -- Deal with NOT operators, inverting sense
1846 while Nkind (Cond) = N_Op_Not loop
1847 Cond := Right_Opnd (Cond);
1851 -- Deal with AND THEN and AND cases
1853 if Nkind (Cond) = N_And_Then
1854 or else Nkind (Cond) = N_Op_And
1856 -- Don't ever try to invert a condition that is of the form
1857 -- of an AND or AND THEN (since we are not doing sufficiently
1858 -- general processing to allow this).
1860 if Sens = False then
1866 -- Recursively process AND and AND THEN branches
1868 Process_Current_Value_Condition (Left_Opnd (Cond), True);
1870 if Op /= N_Empty then
1874 Process_Current_Value_Condition (Right_Opnd (Cond), True);
1877 -- Case of relational operator
1879 elsif Nkind (Cond) in N_Op_Compare then
1882 -- Invert sense of test if inverted test
1884 if Sens = False then
1886 when N_Op_Eq => Op := N_Op_Ne;
1887 when N_Op_Ne => Op := N_Op_Eq;
1888 when N_Op_Lt => Op := N_Op_Ge;
1889 when N_Op_Gt => Op := N_Op_Le;
1890 when N_Op_Le => Op := N_Op_Gt;
1891 when N_Op_Ge => Op := N_Op_Lt;
1892 when others => raise Program_Error;
1896 -- Case of entity op value
1898 if Is_Entity_Name (Left_Opnd (Cond))
1899 and then Ent = Entity (Left_Opnd (Cond))
1900 and then Compile_Time_Known_Value (Right_Opnd (Cond))
1902 Val := Right_Opnd (Cond);
1904 -- Case of value op entity
1906 elsif Is_Entity_Name (Right_Opnd (Cond))
1907 and then Ent = Entity (Right_Opnd (Cond))
1908 and then Compile_Time_Known_Value (Left_Opnd (Cond))
1910 Val := Left_Opnd (Cond);
1912 -- We are effectively swapping operands
1915 when N_Op_Eq => null;
1916 when N_Op_Ne => null;
1917 when N_Op_Lt => Op := N_Op_Gt;
1918 when N_Op_Gt => Op := N_Op_Lt;
1919 when N_Op_Le => Op := N_Op_Ge;
1920 when N_Op_Ge => Op := N_Op_Le;
1921 when others => raise Program_Error;
1930 -- Case of Boolean variable reference, return as though the
1931 -- reference had said var = True.
1934 if Is_Entity_Name (Cond)
1935 and then Ent = Entity (Cond)
1937 Val := New_Occurrence_Of (Standard_True, Sloc (Cond));
1939 if Sens = False then
1946 end Process_Current_Value_Condition;
1948 -- Start of processing for Get_Current_Value_Condition
1954 -- Immediate return, nothing doing, if this is not an object
1956 if Ekind (Ent) not in Object_Kind then
1960 -- Otherwise examine current value
1963 CV : constant Node_Id := Current_Value (Ent);
1968 -- If statement. Condition is known true in THEN section, known False
1969 -- in any ELSIF or ELSE part, and unknown outside the IF statement.
1971 if Nkind (CV) = N_If_Statement then
1973 -- Before start of IF statement
1975 if Loc < Sloc (CV) then
1978 -- After end of IF statement
1980 elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
1984 -- At this stage we know that we are within the IF statement, but
1985 -- unfortunately, the tree does not record the SLOC of the ELSE so
1986 -- we cannot use a simple SLOC comparison to distinguish between
1987 -- the then/else statements, so we have to climb the tree.
1994 while Parent (N) /= CV loop
1997 -- If we fall off the top of the tree, then that's odd, but
1998 -- perhaps it could occur in some error situation, and the
1999 -- safest response is simply to assume that the outcome of
2000 -- the condition is unknown. No point in bombing during an
2001 -- attempt to optimize things.
2008 -- Now we have N pointing to a node whose parent is the IF
2009 -- statement in question, so now we can tell if we are within
2010 -- the THEN statements.
2012 if Is_List_Member (N)
2013 and then List_Containing (N) = Then_Statements (CV)
2017 -- If the variable reference does not come from source, we
2018 -- cannot reliably tell whether it appears in the else part.
2019 -- In particular, if if appears in generated code for a node
2020 -- that requires finalization, it may be attached to a list
2021 -- that has not been yet inserted into the code. For now,
2022 -- treat it as unknown.
2024 elsif not Comes_From_Source (N) then
2027 -- Otherwise we must be in ELSIF or ELSE part
2034 -- ELSIF part. Condition is known true within the referenced
2035 -- ELSIF, known False in any subsequent ELSIF or ELSE part, and
2036 -- unknown before the ELSE part or after the IF statement.
2038 elsif Nkind (CV) = N_Elsif_Part then
2041 -- Before start of ELSIF part
2043 if Loc < Sloc (CV) then
2046 -- After end of IF statement
2048 elsif Loc >= Sloc (Stm) +
2049 Text_Ptr (UI_To_Int (End_Span (Stm)))
2054 -- Again we lack the SLOC of the ELSE, so we need to climb the
2055 -- tree to see if we are within the ELSIF part in question.
2062 while Parent (N) /= Stm loop
2065 -- If we fall off the top of the tree, then that's odd, but
2066 -- perhaps it could occur in some error situation, and the
2067 -- safest response is simply to assume that the outcome of
2068 -- the condition is unknown. No point in bombing during an
2069 -- attempt to optimize things.
2076 -- Now we have N pointing to a node whose parent is the IF
2077 -- statement in question, so see if is the ELSIF part we want.
2078 -- the THEN statements.
2083 -- Otherwise we must be in susbequent ELSIF or ELSE part
2090 -- Iteration scheme of while loop. The condition is known to be
2091 -- true within the body of the loop.
2093 elsif Nkind (CV) = N_Iteration_Scheme then
2095 Loop_Stmt : constant Node_Id := Parent (CV);
2098 -- Before start of body of loop
2100 if Loc < Sloc (Loop_Stmt) then
2103 -- After end of LOOP statement
2105 elsif Loc >= Sloc (End_Label (Loop_Stmt)) then
2108 -- We are within the body of the loop
2115 -- All other cases of Current_Value settings
2121 -- If we fall through here, then we have a reportable condition, Sens
2122 -- is True if the condition is true and False if it needs inverting.
2124 Process_Current_Value_Condition (Condition (CV), Sens);
2126 end Get_Current_Value_Condition;
2128 ---------------------------------
2129 -- Has_Controlled_Coextensions --
2130 ---------------------------------
2132 function Has_Controlled_Coextensions (Typ : Entity_Id) return Boolean is
2137 -- Only consider record types
2139 if Ekind (Typ) /= E_Record_Type
2140 and then Ekind (Typ) /= E_Record_Subtype
2145 if Has_Discriminants (Typ) then
2146 Discr := First_Discriminant (Typ);
2147 while Present (Discr) loop
2148 D_Typ := Etype (Discr);
2150 if Ekind (D_Typ) = E_Anonymous_Access_Type
2152 (Is_Controlled (Directly_Designated_Type (D_Typ))
2154 Is_Concurrent_Type (Directly_Designated_Type (D_Typ)))
2159 Next_Discriminant (Discr);
2164 end Has_Controlled_Coextensions;
2166 --------------------
2167 -- Homonym_Number --
2168 --------------------
2170 function Homonym_Number (Subp : Entity_Id) return Nat is
2176 Hom := Homonym (Subp);
2177 while Present (Hom) loop
2178 if Scope (Hom) = Scope (Subp) then
2182 Hom := Homonym (Hom);
2188 ------------------------------
2189 -- In_Unconditional_Context --
2190 ------------------------------
2192 function In_Unconditional_Context (Node : Node_Id) return Boolean is
2197 while Present (P) loop
2199 when N_Subprogram_Body =>
2202 when N_If_Statement =>
2205 when N_Loop_Statement =>
2208 when N_Case_Statement =>
2217 end In_Unconditional_Context;
2223 procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is
2225 if Present (Ins_Action) then
2226 Insert_Actions (Assoc_Node, New_List (Ins_Action));
2230 -- Version with check(s) suppressed
2232 procedure Insert_Action
2233 (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id)
2236 Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress);
2239 --------------------
2240 -- Insert_Actions --
2241 --------------------
2243 procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is
2247 Wrapped_Node : Node_Id := Empty;
2250 if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
2254 -- Ignore insert of actions from inside default expression in the
2255 -- special preliminary analyze mode. Any insertions at this point
2256 -- have no relevance, since we are only doing the analyze to freeze
2257 -- the types of any static expressions. See section "Handling of
2258 -- Default Expressions" in the spec of package Sem for further details.
2260 if In_Default_Expression then
2264 -- If the action derives from stuff inside a record, then the actions
2265 -- are attached to the current scope, to be inserted and analyzed on
2266 -- exit from the scope. The reason for this is that we may also
2267 -- be generating freeze actions at the same time, and they must
2268 -- eventually be elaborated in the correct order.
2270 if Is_Record_Type (Current_Scope)
2271 and then not Is_Frozen (Current_Scope)
2273 if No (Scope_Stack.Table
2274 (Scope_Stack.Last).Pending_Freeze_Actions)
2276 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
2281 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
2287 -- We now intend to climb up the tree to find the right point to
2288 -- insert the actions. We start at Assoc_Node, unless this node is
2289 -- a subexpression in which case we start with its parent. We do this
2290 -- for two reasons. First it speeds things up. Second, if Assoc_Node
2291 -- is itself one of the special nodes like N_And_Then, then we assume
2292 -- that an initial request to insert actions for such a node does not
2293 -- expect the actions to get deposited in the node for later handling
2294 -- when the node is expanded, since clearly the node is being dealt
2295 -- with by the caller. Note that in the subexpression case, N is
2296 -- always the child we came from.
2298 -- N_Raise_xxx_Error is an annoying special case, it is a statement
2299 -- if it has type Standard_Void_Type, and a subexpression otherwise.
2300 -- otherwise. Procedure attribute references are also statements.
2302 if Nkind (Assoc_Node) in N_Subexpr
2303 and then (Nkind (Assoc_Node) in N_Raise_xxx_Error
2304 or else Etype (Assoc_Node) /= Standard_Void_Type)
2305 and then (Nkind (Assoc_Node) /= N_Attribute_Reference
2307 not Is_Procedure_Attribute_Name
2308 (Attribute_Name (Assoc_Node)))
2310 P := Assoc_Node; -- ??? does not agree with above!
2311 N := Parent (Assoc_Node);
2313 -- Non-subexpression case. Note that N is initially Empty in this
2314 -- case (N is only guaranteed Non-Empty in the subexpr case).
2321 -- Capture root of the transient scope
2323 if Scope_Is_Transient then
2324 Wrapped_Node := Node_To_Be_Wrapped;
2328 pragma Assert (Present (P));
2332 -- Case of right operand of AND THEN or OR ELSE. Put the actions
2333 -- in the Actions field of the right operand. They will be moved
2334 -- out further when the AND THEN or OR ELSE operator is expanded.
2335 -- Nothing special needs to be done for the left operand since
2336 -- in that case the actions are executed unconditionally.
2338 when N_And_Then | N_Or_Else =>
2339 if N = Right_Opnd (P) then
2341 -- We are now going to either append the actions to the
2342 -- actions field of the short-circuit operation. We will
2343 -- also analyze the actions now.
2345 -- This analysis is really too early, the proper thing would
2346 -- be to just park them there now, and only analyze them if
2347 -- we find we really need them, and to it at the proper
2348 -- final insertion point. However attempting to this proved
2349 -- tricky, so for now we just kill current values before and
2350 -- after the analyze call to make sure we avoid peculiar
2351 -- optimizations from this out of order insertion.
2353 Kill_Current_Values;
2355 if Present (Actions (P)) then
2356 Insert_List_After_And_Analyze
2357 (Last (Actions (P)), Ins_Actions);
2359 Set_Actions (P, Ins_Actions);
2360 Analyze_List (Actions (P));
2363 Kill_Current_Values;
2368 -- Then or Else operand of conditional expression. Add actions to
2369 -- Then_Actions or Else_Actions field as appropriate. The actions
2370 -- will be moved further out when the conditional is expanded.
2372 when N_Conditional_Expression =>
2374 ThenX : constant Node_Id := Next (First (Expressions (P)));
2375 ElseX : constant Node_Id := Next (ThenX);
2378 -- Actions belong to the then expression, temporarily
2379 -- place them as Then_Actions of the conditional expr.
2380 -- They will be moved to the proper place later when
2381 -- the conditional expression is expanded.
2384 if Present (Then_Actions (P)) then
2385 Insert_List_After_And_Analyze
2386 (Last (Then_Actions (P)), Ins_Actions);
2388 Set_Then_Actions (P, Ins_Actions);
2389 Analyze_List (Then_Actions (P));
2394 -- Actions belong to the else expression, temporarily
2395 -- place them as Else_Actions of the conditional expr.
2396 -- They will be moved to the proper place later when
2397 -- the conditional expression is expanded.
2399 elsif N = ElseX then
2400 if Present (Else_Actions (P)) then
2401 Insert_List_After_And_Analyze
2402 (Last (Else_Actions (P)), Ins_Actions);
2404 Set_Else_Actions (P, Ins_Actions);
2405 Analyze_List (Else_Actions (P));
2410 -- Actions belong to the condition. In this case they are
2411 -- unconditionally executed, and so we can continue the
2412 -- search for the proper insert point.
2419 -- Case of appearing in the condition of a while expression or
2420 -- elsif. We insert the actions into the Condition_Actions field.
2421 -- They will be moved further out when the while loop or elsif
2424 when N_Iteration_Scheme |
2427 if N = Condition (P) then
2428 if Present (Condition_Actions (P)) then
2429 Insert_List_After_And_Analyze
2430 (Last (Condition_Actions (P)), Ins_Actions);
2432 Set_Condition_Actions (P, Ins_Actions);
2434 -- Set the parent of the insert actions explicitly.
2435 -- This is not a syntactic field, but we need the
2436 -- parent field set, in particular so that freeze
2437 -- can understand that it is dealing with condition
2438 -- actions, and properly insert the freezing actions.
2440 Set_Parent (Ins_Actions, P);
2441 Analyze_List (Condition_Actions (P));
2447 -- Statements, declarations, pragmas, representation clauses
2452 N_Procedure_Call_Statement |
2453 N_Statement_Other_Than_Procedure_Call |
2459 -- Representation_Clause
2462 N_Attribute_Definition_Clause |
2463 N_Enumeration_Representation_Clause |
2464 N_Record_Representation_Clause |
2468 N_Abstract_Subprogram_Declaration |
2470 N_Exception_Declaration |
2471 N_Exception_Renaming_Declaration |
2472 N_Formal_Abstract_Subprogram_Declaration |
2473 N_Formal_Concrete_Subprogram_Declaration |
2474 N_Formal_Object_Declaration |
2475 N_Formal_Type_Declaration |
2476 N_Full_Type_Declaration |
2477 N_Function_Instantiation |
2478 N_Generic_Function_Renaming_Declaration |
2479 N_Generic_Package_Declaration |
2480 N_Generic_Package_Renaming_Declaration |
2481 N_Generic_Procedure_Renaming_Declaration |
2482 N_Generic_Subprogram_Declaration |
2483 N_Implicit_Label_Declaration |
2484 N_Incomplete_Type_Declaration |
2485 N_Number_Declaration |
2486 N_Object_Declaration |
2487 N_Object_Renaming_Declaration |
2489 N_Package_Body_Stub |
2490 N_Package_Declaration |
2491 N_Package_Instantiation |
2492 N_Package_Renaming_Declaration |
2493 N_Private_Extension_Declaration |
2494 N_Private_Type_Declaration |
2495 N_Procedure_Instantiation |
2497 N_Protected_Body_Stub |
2498 N_Protected_Type_Declaration |
2499 N_Single_Task_Declaration |
2501 N_Subprogram_Body_Stub |
2502 N_Subprogram_Declaration |
2503 N_Subprogram_Renaming_Declaration |
2504 N_Subtype_Declaration |
2507 N_Task_Type_Declaration |
2509 -- Freeze entity behaves like a declaration or statement
2513 -- Do not insert here if the item is not a list member (this
2514 -- happens for example with a triggering statement, and the
2515 -- proper approach is to insert before the entire select).
2517 if not Is_List_Member (P) then
2520 -- Do not insert if parent of P is an N_Component_Association
2521 -- node (i.e. we are in the context of an N_Aggregate or
2522 -- N_Extension_Aggregate node. In this case we want to insert
2523 -- before the entire aggregate.
2525 elsif Nkind (Parent (P)) = N_Component_Association then
2528 -- Do not insert if the parent of P is either an N_Variant
2529 -- node or an N_Record_Definition node, meaning in either
2530 -- case that P is a member of a component list, and that
2531 -- therefore the actions should be inserted outside the
2532 -- complete record declaration.
2534 elsif Nkind (Parent (P)) = N_Variant
2535 or else Nkind (Parent (P)) = N_Record_Definition
2539 -- Do not insert freeze nodes within the loop generated for
2540 -- an aggregate, because they may be elaborated too late for
2541 -- subsequent use in the back end: within a package spec the
2542 -- loop is part of the elaboration procedure and is only
2543 -- elaborated during the second pass.
2544 -- If the loop comes from source, or the entity is local to
2545 -- the loop itself it must remain within.
2547 elsif Nkind (Parent (P)) = N_Loop_Statement
2548 and then not Comes_From_Source (Parent (P))
2549 and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
2551 Scope (Entity (First (Ins_Actions))) /= Current_Scope
2555 -- Otherwise we can go ahead and do the insertion
2557 elsif P = Wrapped_Node then
2558 Store_Before_Actions_In_Scope (Ins_Actions);
2562 Insert_List_Before_And_Analyze (P, Ins_Actions);
2566 -- A special case, N_Raise_xxx_Error can act either as a
2567 -- statement or a subexpression. We tell the difference
2568 -- by looking at the Etype. It is set to Standard_Void_Type
2569 -- in the statement case.
2572 N_Raise_xxx_Error =>
2573 if Etype (P) = Standard_Void_Type then
2574 if P = Wrapped_Node then
2575 Store_Before_Actions_In_Scope (Ins_Actions);
2577 Insert_List_Before_And_Analyze (P, Ins_Actions);
2582 -- In the subexpression case, keep climbing
2588 -- If a component association appears within a loop created for
2589 -- an array aggregate, attach the actions to the association so
2590 -- they can be subsequently inserted within the loop. For other
2591 -- component associations insert outside of the aggregate. For
2592 -- an association that will generate a loop, its Loop_Actions
2593 -- attribute is already initialized (see exp_aggr.adb).
2595 -- The list of loop_actions can in turn generate additional ones,
2596 -- that are inserted before the associated node. If the associated
2597 -- node is outside the aggregate, the new actions are collected
2598 -- at the end of the loop actions, to respect the order in which
2599 -- they are to be elaborated.
2602 N_Component_Association =>
2603 if Nkind (Parent (P)) = N_Aggregate
2604 and then Present (Loop_Actions (P))
2606 if Is_Empty_List (Loop_Actions (P)) then
2607 Set_Loop_Actions (P, Ins_Actions);
2608 Analyze_List (Ins_Actions);
2615 -- Check whether these actions were generated
2616 -- by a declaration that is part of the loop_
2617 -- actions for the component_association.
2620 while Present (Decl) loop
2621 exit when Parent (Decl) = P
2622 and then Is_List_Member (Decl)
2624 List_Containing (Decl) = Loop_Actions (P);
2625 Decl := Parent (Decl);
2628 if Present (Decl) then
2629 Insert_List_Before_And_Analyze
2630 (Decl, Ins_Actions);
2632 Insert_List_After_And_Analyze
2633 (Last (Loop_Actions (P)), Ins_Actions);
2644 -- Another special case, an attribute denoting a procedure call
2647 N_Attribute_Reference =>
2648 if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
2649 if P = Wrapped_Node then
2650 Store_Before_Actions_In_Scope (Ins_Actions);
2652 Insert_List_Before_And_Analyze (P, Ins_Actions);
2657 -- In the subexpression case, keep climbing
2663 -- For all other node types, keep climbing tree
2667 N_Accept_Alternative |
2668 N_Access_Definition |
2669 N_Access_Function_Definition |
2670 N_Access_Procedure_Definition |
2671 N_Access_To_Object_Definition |
2674 N_Case_Statement_Alternative |
2675 N_Character_Literal |
2676 N_Compilation_Unit |
2677 N_Compilation_Unit_Aux |
2678 N_Component_Clause |
2679 N_Component_Declaration |
2680 N_Component_Definition |
2682 N_Constrained_Array_Definition |
2683 N_Decimal_Fixed_Point_Definition |
2684 N_Defining_Character_Literal |
2685 N_Defining_Identifier |
2686 N_Defining_Operator_Symbol |
2687 N_Defining_Program_Unit_Name |
2688 N_Delay_Alternative |
2689 N_Delta_Constraint |
2690 N_Derived_Type_Definition |
2692 N_Digits_Constraint |
2693 N_Discriminant_Association |
2694 N_Discriminant_Specification |
2696 N_Entry_Body_Formal_Part |
2697 N_Entry_Call_Alternative |
2698 N_Entry_Declaration |
2699 N_Entry_Index_Specification |
2700 N_Enumeration_Type_Definition |
2702 N_Exception_Handler |
2704 N_Explicit_Dereference |
2705 N_Extension_Aggregate |
2706 N_Floating_Point_Definition |
2707 N_Formal_Decimal_Fixed_Point_Definition |
2708 N_Formal_Derived_Type_Definition |
2709 N_Formal_Discrete_Type_Definition |
2710 N_Formal_Floating_Point_Definition |
2711 N_Formal_Modular_Type_Definition |
2712 N_Formal_Ordinary_Fixed_Point_Definition |
2713 N_Formal_Package_Declaration |
2714 N_Formal_Private_Type_Definition |
2715 N_Formal_Signed_Integer_Type_Definition |
2717 N_Function_Specification |
2718 N_Generic_Association |
2719 N_Handled_Sequence_Of_Statements |
2722 N_Index_Or_Discriminant_Constraint |
2723 N_Indexed_Component |
2727 N_Loop_Parameter_Specification |
2729 N_Modular_Type_Definition |
2755 N_Op_Shift_Right_Arithmetic |
2759 N_Ordinary_Fixed_Point_Definition |
2761 N_Package_Specification |
2762 N_Parameter_Association |
2763 N_Parameter_Specification |
2764 N_Pop_Constraint_Error_Label |
2765 N_Pop_Program_Error_Label |
2766 N_Pop_Storage_Error_Label |
2767 N_Pragma_Argument_Association |
2768 N_Procedure_Specification |
2769 N_Protected_Definition |
2770 N_Push_Constraint_Error_Label |
2771 N_Push_Program_Error_Label |
2772 N_Push_Storage_Error_Label |
2773 N_Qualified_Expression |
2775 N_Range_Constraint |
2777 N_Real_Range_Specification |
2778 N_Record_Definition |
2780 N_Selected_Component |
2781 N_Signed_Integer_Type_Definition |
2782 N_Single_Protected_Declaration |
2786 N_Subtype_Indication |
2789 N_Terminate_Alternative |
2790 N_Triggering_Alternative |
2792 N_Unchecked_Expression |
2793 N_Unchecked_Type_Conversion |
2794 N_Unconstrained_Array_Definition |
2797 N_Use_Package_Clause |
2801 N_Validate_Unchecked_Conversion |
2808 -- Make sure that inserted actions stay in the transient scope
2810 if P = Wrapped_Node then
2811 Store_Before_Actions_In_Scope (Ins_Actions);
2815 -- If we fall through above tests, keep climbing tree
2819 if Nkind (Parent (N)) = N_Subunit then
2821 -- This is the proper body corresponding to a stub. Insertion
2822 -- must be done at the point of the stub, which is in the decla-
2823 -- tive part of the parent unit.
2825 P := Corresponding_Stub (Parent (N));
2833 -- Version with check(s) suppressed
2835 procedure Insert_Actions
2836 (Assoc_Node : Node_Id;
2837 Ins_Actions : List_Id;
2838 Suppress : Check_Id)
2841 if Suppress = All_Checks then
2843 Svg : constant Suppress_Array := Scope_Suppress;
2845 Scope_Suppress := (others => True);
2846 Insert_Actions (Assoc_Node, Ins_Actions);
2847 Scope_Suppress := Svg;
2852 Svg : constant Boolean := Scope_Suppress (Suppress);
2854 Scope_Suppress (Suppress) := True;
2855 Insert_Actions (Assoc_Node, Ins_Actions);
2856 Scope_Suppress (Suppress) := Svg;
2861 --------------------------
2862 -- Insert_Actions_After --
2863 --------------------------
2865 procedure Insert_Actions_After
2866 (Assoc_Node : Node_Id;
2867 Ins_Actions : List_Id)
2870 if Scope_Is_Transient
2871 and then Assoc_Node = Node_To_Be_Wrapped
2873 Store_After_Actions_In_Scope (Ins_Actions);
2875 Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
2877 end Insert_Actions_After;
2879 ---------------------------------
2880 -- Insert_Library_Level_Action --
2881 ---------------------------------
2883 procedure Insert_Library_Level_Action (N : Node_Id) is
2884 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2887 Push_Scope (Cunit_Entity (Main_Unit));
2888 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2890 if No (Actions (Aux)) then
2891 Set_Actions (Aux, New_List (N));
2893 Append (N, Actions (Aux));
2898 end Insert_Library_Level_Action;
2900 ----------------------------------
2901 -- Insert_Library_Level_Actions --
2902 ----------------------------------
2904 procedure Insert_Library_Level_Actions (L : List_Id) is
2905 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2908 if Is_Non_Empty_List (L) then
2909 Push_Scope (Cunit_Entity (Main_Unit));
2910 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2912 if No (Actions (Aux)) then
2913 Set_Actions (Aux, L);
2916 Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
2921 end Insert_Library_Level_Actions;
2923 ----------------------
2924 -- Inside_Init_Proc --
2925 ----------------------
2927 function Inside_Init_Proc return Boolean is
2933 and then S /= Standard_Standard
2935 if Is_Init_Proc (S) then
2943 end Inside_Init_Proc;
2945 ----------------------------
2946 -- Is_All_Null_Statements --
2947 ----------------------------
2949 function Is_All_Null_Statements (L : List_Id) return Boolean is
2954 while Present (Stm) loop
2955 if Nkind (Stm) /= N_Null_Statement then
2963 end Is_All_Null_Statements;
2965 ----------------------------------
2966 -- Is_Library_Level_Tagged_Type --
2967 ----------------------------------
2969 function Is_Library_Level_Tagged_Type (Typ : Entity_Id) return Boolean is
2971 return Is_Tagged_Type (Typ)
2972 and then Is_Library_Level_Entity (Typ);
2973 end Is_Library_Level_Tagged_Type;
2975 -----------------------------------------
2976 -- Is_Predefined_Dispatching_Operation --
2977 -----------------------------------------
2979 function Is_Predefined_Dispatching_Operation (E : Entity_Id) return Boolean
2981 TSS_Name : TSS_Name_Type;
2984 if not Is_Dispatching_Operation (E) then
2988 Get_Name_String (Chars (E));
2990 if Name_Len > TSS_Name_Type'Last then
2991 TSS_Name := TSS_Name_Type (Name_Buffer (Name_Len - TSS_Name'Length + 1
2993 if Chars (E) = Name_uSize
2994 or else Chars (E) = Name_uAlignment
2995 or else TSS_Name = TSS_Stream_Read
2996 or else TSS_Name = TSS_Stream_Write
2997 or else TSS_Name = TSS_Stream_Input
2998 or else TSS_Name = TSS_Stream_Output
3000 (Chars (E) = Name_Op_Eq
3001 and then Etype (First_Entity (E)) = Etype (Last_Entity (E)))
3002 or else Chars (E) = Name_uAssign
3003 or else TSS_Name = TSS_Deep_Adjust
3004 or else TSS_Name = TSS_Deep_Finalize
3005 or else (Ada_Version >= Ada_05
3006 and then (Chars (E) = Name_uDisp_Asynchronous_Select
3007 or else Chars (E) = Name_uDisp_Conditional_Select
3008 or else Chars (E) = Name_uDisp_Get_Prim_Op_Kind
3009 or else Chars (E) = Name_uDisp_Get_Task_Id
3010 or else Chars (E) = Name_uDisp_Requeue
3011 or else Chars (E) = Name_uDisp_Timed_Select))
3018 end Is_Predefined_Dispatching_Operation;
3020 ----------------------------------
3021 -- Is_Possibly_Unaligned_Object --
3022 ----------------------------------
3024 function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is
3025 T : constant Entity_Id := Etype (N);
3028 -- If renamed object, apply test to underlying object
3030 if Is_Entity_Name (N)
3031 and then Is_Object (Entity (N))
3032 and then Present (Renamed_Object (Entity (N)))
3034 return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N)));
3037 -- Tagged and controlled types and aliased types are always aligned,
3038 -- as are concurrent types.
3041 or else Has_Controlled_Component (T)
3042 or else Is_Concurrent_Type (T)
3043 or else Is_Tagged_Type (T)
3044 or else Is_Controlled (T)
3049 -- If this is an element of a packed array, may be unaligned
3051 if Is_Ref_To_Bit_Packed_Array (N) then
3055 -- Case of component reference
3057 if Nkind (N) = N_Selected_Component then
3059 P : constant Node_Id := Prefix (N);
3060 C : constant Entity_Id := Entity (Selector_Name (N));
3065 -- If component reference is for an array with non-static bounds,
3066 -- then it is always aligned: we can only process unaligned
3067 -- arrays with static bounds (more accurately bounds known at
3070 if Is_Array_Type (T)
3071 and then not Compile_Time_Known_Bounds (T)
3076 -- If component is aliased, it is definitely properly aligned
3078 if Is_Aliased (C) then
3082 -- If component is for a type implemented as a scalar, and the
3083 -- record is packed, and the component is other than the first
3084 -- component of the record, then the component may be unaligned.
3086 if Is_Packed (Etype (P))
3087 and then Represented_As_Scalar (Etype (C))
3088 and then First_Entity (Scope (C)) /= C
3093 -- Compute maximum possible alignment for T
3095 -- If alignment is known, then that settles things
3097 if Known_Alignment (T) then
3098 M := UI_To_Int (Alignment (T));
3100 -- If alignment is not known, tentatively set max alignment
3103 M := Ttypes.Maximum_Alignment;
3105 -- We can reduce this if the Esize is known since the default
3106 -- alignment will never be more than the smallest power of 2
3107 -- that does not exceed this Esize value.
3109 if Known_Esize (T) then
3110 S := UI_To_Int (Esize (T));
3112 while (M / 2) >= S loop
3118 -- If the component reference is for a record that has a specified
3119 -- alignment, and we either know it is too small, or cannot tell,
3120 -- then the component may be unaligned
3122 if Known_Alignment (Etype (P))
3123 and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment
3124 and then M > Alignment (Etype (P))
3129 -- Case of component clause present which may specify an
3130 -- unaligned position.
3132 if Present (Component_Clause (C)) then
3134 -- Otherwise we can do a test to make sure that the actual
3135 -- start position in the record, and the length, are both
3136 -- consistent with the required alignment. If not, we know
3137 -- that we are unaligned.
3140 Align_In_Bits : constant Nat := M * System_Storage_Unit;
3142 if Component_Bit_Offset (C) mod Align_In_Bits /= 0
3143 or else Esize (C) mod Align_In_Bits /= 0
3150 -- Otherwise, for a component reference, test prefix
3152 return Is_Possibly_Unaligned_Object (P);
3155 -- If not a component reference, must be aligned
3160 end Is_Possibly_Unaligned_Object;
3162 ---------------------------------
3163 -- Is_Possibly_Unaligned_Slice --
3164 ---------------------------------
3166 function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is
3168 -- Go to renamed object
3170 if Is_Entity_Name (N)
3171 and then Is_Object (Entity (N))
3172 and then Present (Renamed_Object (Entity (N)))
3174 return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N)));
3177 -- The reference must be a slice
3179 if Nkind (N) /= N_Slice then
3183 -- Always assume the worst for a nested record component with a
3184 -- component clause, which gigi/gcc does not appear to handle well.
3185 -- It is not clear why this special test is needed at all ???
3187 if Nkind (Prefix (N)) = N_Selected_Component
3188 and then Nkind (Prefix (Prefix (N))) = N_Selected_Component
3190 Present (Component_Clause (Entity (Selector_Name (Prefix (N)))))
3195 -- We only need to worry if the target has strict alignment
3197 if not Target_Strict_Alignment then
3201 -- If it is a slice, then look at the array type being sliced
3204 Sarr : constant Node_Id := Prefix (N);
3205 -- Prefix of the slice, i.e. the array being sliced
3207 Styp : constant Entity_Id := Etype (Prefix (N));
3208 -- Type of the array being sliced
3214 -- The problems arise if the array object that is being sliced
3215 -- is a component of a record or array, and we cannot guarantee
3216 -- the alignment of the array within its containing object.
3218 -- To investigate this, we look at successive prefixes to see
3219 -- if we have a worrisome indexed or selected component.
3223 -- Case of array is part of an indexed component reference
3225 if Nkind (Pref) = N_Indexed_Component then
3226 Ptyp := Etype (Prefix (Pref));
3228 -- The only problematic case is when the array is packed,
3229 -- in which case we really know nothing about the alignment
3230 -- of individual components.
3232 if Is_Bit_Packed_Array (Ptyp) then
3236 -- Case of array is part of a selected component reference
3238 elsif Nkind (Pref) = N_Selected_Component then
3239 Ptyp := Etype (Prefix (Pref));
3241 -- We are definitely in trouble if the record in question
3242 -- has an alignment, and either we know this alignment is
3243 -- inconsistent with the alignment of the slice, or we
3244 -- don't know what the alignment of the slice should be.
3246 if Known_Alignment (Ptyp)
3247 and then (Unknown_Alignment (Styp)
3248 or else Alignment (Styp) > Alignment (Ptyp))
3253 -- We are in potential trouble if the record type is packed.
3254 -- We could special case when we know that the array is the
3255 -- first component, but that's not such a simple case ???
3257 if Is_Packed (Ptyp) then
3261 -- We are in trouble if there is a component clause, and
3262 -- either we do not know the alignment of the slice, or
3263 -- the alignment of the slice is inconsistent with the
3264 -- bit position specified by the component clause.
3267 Field : constant Entity_Id := Entity (Selector_Name (Pref));
3269 if Present (Component_Clause (Field))
3271 (Unknown_Alignment (Styp)
3273 (Component_Bit_Offset (Field) mod
3274 (System_Storage_Unit * Alignment (Styp))) /= 0)
3280 -- For cases other than selected or indexed components we
3281 -- know we are OK, since no issues arise over alignment.
3287 -- We processed an indexed component or selected component
3288 -- reference that looked safe, so keep checking prefixes.
3290 Pref := Prefix (Pref);
3293 end Is_Possibly_Unaligned_Slice;
3295 --------------------------------
3296 -- Is_Ref_To_Bit_Packed_Array --
3297 --------------------------------
3299 function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is
3304 if Is_Entity_Name (N)
3305 and then Is_Object (Entity (N))
3306 and then Present (Renamed_Object (Entity (N)))
3308 return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N)));
3311 if Nkind (N) = N_Indexed_Component
3313 Nkind (N) = N_Selected_Component
3315 if Is_Bit_Packed_Array (Etype (Prefix (N))) then
3318 Result := Is_Ref_To_Bit_Packed_Array (Prefix (N));
3321 if Result and then Nkind (N) = N_Indexed_Component then
3322 Expr := First (Expressions (N));
3323 while Present (Expr) loop
3324 Force_Evaluation (Expr);
3334 end Is_Ref_To_Bit_Packed_Array;
3336 --------------------------------
3337 -- Is_Ref_To_Bit_Packed_Slice --
3338 --------------------------------
3340 function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is
3342 if Nkind (N) = N_Type_Conversion then
3343 return Is_Ref_To_Bit_Packed_Slice (Expression (N));
3345 elsif Is_Entity_Name (N)
3346 and then Is_Object (Entity (N))
3347 and then Present (Renamed_Object (Entity (N)))
3349 return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N)));
3351 elsif Nkind (N) = N_Slice
3352 and then Is_Bit_Packed_Array (Etype (Prefix (N)))
3356 elsif Nkind (N) = N_Indexed_Component
3358 Nkind (N) = N_Selected_Component
3360 return Is_Ref_To_Bit_Packed_Slice (Prefix (N));
3365 end Is_Ref_To_Bit_Packed_Slice;
3367 -----------------------
3368 -- Is_Renamed_Object --
3369 -----------------------
3371 function Is_Renamed_Object (N : Node_Id) return Boolean is
3372 Pnod : constant Node_Id := Parent (N);
3373 Kind : constant Node_Kind := Nkind (Pnod);
3376 if Kind = N_Object_Renaming_Declaration then
3379 elsif Kind = N_Indexed_Component
3380 or else Kind = N_Selected_Component
3382 return Is_Renamed_Object (Pnod);
3387 end Is_Renamed_Object;
3389 ----------------------------
3390 -- Is_Untagged_Derivation --
3391 ----------------------------
3393 function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
3395 return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
3397 (Is_Private_Type (T) and then Present (Full_View (T))
3398 and then not Is_Tagged_Type (Full_View (T))
3399 and then Is_Derived_Type (Full_View (T))
3400 and then Etype (Full_View (T)) /= T);
3401 end Is_Untagged_Derivation;
3403 --------------------
3404 -- Kill_Dead_Code --
3405 --------------------
3407 procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is
3410 Remove_Warning_Messages (N);
3414 ("?this code can never be executed and has been deleted!", N);
3417 -- Recurse into block statements and bodies to process declarations
3420 if Nkind (N) = N_Block_Statement
3421 or else Nkind (N) = N_Subprogram_Body
3422 or else Nkind (N) = N_Package_Body
3424 Kill_Dead_Code (Declarations (N), False);
3425 Kill_Dead_Code (Statements (Handled_Statement_Sequence (N)));
3427 if Nkind (N) = N_Subprogram_Body then
3428 Set_Is_Eliminated (Defining_Entity (N));
3431 elsif Nkind (N) = N_Package_Declaration then
3432 Kill_Dead_Code (Visible_Declarations (Specification (N)));
3433 Kill_Dead_Code (Private_Declarations (Specification (N)));
3435 -- ??? After this point, Delete_Tree has been called on all
3436 -- declarations in Specification (N), so references to
3437 -- entities therein look suspicious.
3440 E : Entity_Id := First_Entity (Defining_Entity (N));
3442 while Present (E) loop
3443 if Ekind (E) = E_Operator then
3444 Set_Is_Eliminated (E);
3451 -- Recurse into composite statement to kill individual statements,
3452 -- in particular instantiations.
3454 elsif Nkind (N) = N_If_Statement then
3455 Kill_Dead_Code (Then_Statements (N));
3456 Kill_Dead_Code (Elsif_Parts (N));
3457 Kill_Dead_Code (Else_Statements (N));
3459 elsif Nkind (N) = N_Loop_Statement then
3460 Kill_Dead_Code (Statements (N));
3462 elsif Nkind (N) = N_Case_Statement then
3466 Alt := First (Alternatives (N));
3467 while Present (Alt) loop
3468 Kill_Dead_Code (Statements (Alt));
3473 elsif Nkind (N) = N_Case_Statement_Alternative then
3474 Kill_Dead_Code (Statements (N));
3476 -- Deal with dead instances caused by deleting instantiations
3478 elsif Nkind (N) in N_Generic_Instantiation then
3479 Remove_Dead_Instance (N);
3484 -- Case where argument is a list of nodes to be killed
3486 procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is
3491 if Is_Non_Empty_List (L) then
3493 while Present (N) loop
3494 Kill_Dead_Code (N, W);
3501 ------------------------
3502 -- Known_Non_Negative --
3503 ------------------------
3505 function Known_Non_Negative (Opnd : Node_Id) return Boolean is
3507 if Is_OK_Static_Expression (Opnd)
3508 and then Expr_Value (Opnd) >= 0
3514 Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd));
3518 Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0;
3521 end Known_Non_Negative;
3523 --------------------
3524 -- Known_Non_Null --
3525 --------------------
3527 function Known_Non_Null (N : Node_Id) return Boolean is
3529 -- Checks for case where N is an entity reference
3531 if Is_Entity_Name (N) and then Present (Entity (N)) then
3533 E : constant Entity_Id := Entity (N);
3538 -- First check if we are in decisive conditional
3540 Get_Current_Value_Condition (N, Op, Val);
3542 if Known_Null (Val) then
3543 if Op = N_Op_Eq then
3545 elsif Op = N_Op_Ne then
3550 -- If OK to do replacement, test Is_Known_Non_Null flag
3552 if OK_To_Do_Constant_Replacement (E) then
3553 return Is_Known_Non_Null (E);
3555 -- Otherwise if not safe to do replacement, then say so
3562 -- True if access attribute
3564 elsif Nkind (N) = N_Attribute_Reference
3565 and then (Attribute_Name (N) = Name_Access
3567 Attribute_Name (N) = Name_Unchecked_Access
3569 Attribute_Name (N) = Name_Unrestricted_Access)
3573 -- True if allocator
3575 elsif Nkind (N) = N_Allocator then
3578 -- For a conversion, true if expression is known non-null
3580 elsif Nkind (N) = N_Type_Conversion then
3581 return Known_Non_Null (Expression (N));
3583 -- Above are all cases where the value could be determined to be
3584 -- non-null. In all other cases, we don't know, so return False.
3595 function Known_Null (N : Node_Id) return Boolean is
3597 -- Checks for case where N is an entity reference
3599 if Is_Entity_Name (N) and then Present (Entity (N)) then
3601 E : constant Entity_Id := Entity (N);
3606 -- Constant null value is for sure null
3608 if Ekind (E) = E_Constant
3609 and then Known_Null (Constant_Value (E))
3614 -- First check if we are in decisive conditional
3616 Get_Current_Value_Condition (N, Op, Val);
3618 if Known_Null (Val) then
3619 if Op = N_Op_Eq then
3621 elsif Op = N_Op_Ne then
3626 -- If OK to do replacement, test Is_Known_Null flag
3628 if OK_To_Do_Constant_Replacement (E) then
3629 return Is_Known_Null (E);
3631 -- Otherwise if not safe to do replacement, then say so
3638 -- True if explicit reference to null
3640 elsif Nkind (N) = N_Null then
3643 -- For a conversion, true if expression is known null
3645 elsif Nkind (N) = N_Type_Conversion then
3646 return Known_Null (Expression (N));
3648 -- Above are all cases where the value could be determined to be null.
3649 -- In all other cases, we don't know, so return False.
3656 -----------------------------
3657 -- Make_CW_Equivalent_Type --
3658 -----------------------------
3660 -- Create a record type used as an equivalent of any member
3661 -- of the class which takes its size from exp.
3663 -- Generate the following code:
3665 -- type Equiv_T is record
3666 -- _parent : T (List of discriminant constaints taken from Exp);
3667 -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
3670 -- ??? Note that this type does not guarantee same alignment as all
3673 function Make_CW_Equivalent_Type
3675 E : Node_Id) return Entity_Id
3677 Loc : constant Source_Ptr := Sloc (E);
3678 Root_Typ : constant Entity_Id := Root_Type (T);
3679 List_Def : constant List_Id := Empty_List;
3680 Comp_List : constant List_Id := New_List;
3681 Equiv_Type : Entity_Id;
3682 Range_Type : Entity_Id;
3683 Str_Type : Entity_Id;
3684 Constr_Root : Entity_Id;
3688 if not Has_Discriminants (Root_Typ) then
3689 Constr_Root := Root_Typ;
3692 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
3694 -- subtype cstr__n is T (List of discr constraints taken from Exp)
3696 Append_To (List_Def,
3697 Make_Subtype_Declaration (Loc,
3698 Defining_Identifier => Constr_Root,
3699 Subtype_Indication =>
3700 Make_Subtype_From_Expr (E, Root_Typ)));
3703 -- Generate the range subtype declaration
3705 Range_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('G'));
3707 if not Is_Interface (Root_Typ) then
3708 -- subtype rg__xx is
3709 -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit
3712 Make_Op_Subtract (Loc,
3714 Make_Attribute_Reference (Loc,
3716 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3717 Attribute_Name => Name_Size),
3719 Make_Attribute_Reference (Loc,
3720 Prefix => New_Reference_To (Constr_Root, Loc),
3721 Attribute_Name => Name_Object_Size));
3723 -- subtype rg__xx is
3724 -- Storage_Offset range 1 .. Expr'size / Storage_Unit
3727 Make_Attribute_Reference (Loc,
3729 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3730 Attribute_Name => Name_Size);
3733 Set_Paren_Count (Sizexpr, 1);
3735 Append_To (List_Def,
3736 Make_Subtype_Declaration (Loc,
3737 Defining_Identifier => Range_Type,
3738 Subtype_Indication =>
3739 Make_Subtype_Indication (Loc,
3740 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc),
3741 Constraint => Make_Range_Constraint (Loc,
3744 Low_Bound => Make_Integer_Literal (Loc, 1),
3746 Make_Op_Divide (Loc,
3747 Left_Opnd => Sizexpr,
3748 Right_Opnd => Make_Integer_Literal (Loc,
3749 Intval => System_Storage_Unit)))))));
3751 -- subtype str__nn is Storage_Array (rg__x);
3753 Str_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
3754 Append_To (List_Def,
3755 Make_Subtype_Declaration (Loc,
3756 Defining_Identifier => Str_Type,
3757 Subtype_Indication =>
3758 Make_Subtype_Indication (Loc,
3759 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc),
3761 Make_Index_Or_Discriminant_Constraint (Loc,
3763 New_List (New_Reference_To (Range_Type, Loc))))));
3765 -- type Equiv_T is record
3766 -- [ _parent : Tnn; ]
3770 Equiv_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
3772 -- When the target requires front-end layout, it's necessary to allow
3773 -- the equivalent type to be frozen so that layout can occur (when the
3774 -- associated class-wide subtype is frozen, the equivalent type will
3775 -- be frozen, see freeze.adb). For other targets, Gigi wants to have
3776 -- the equivalent type marked as frozen and deals with this type itself.
3777 -- In the Gigi case this will also avoid the generation of an init
3778 -- procedure for the type.
3780 if not Frontend_Layout_On_Target then
3781 Set_Is_Frozen (Equiv_Type);
3784 Set_Ekind (Equiv_Type, E_Record_Type);
3785 Set_Parent_Subtype (Equiv_Type, Constr_Root);
3787 if not Is_Interface (Root_Typ) then
3788 Append_To (Comp_List,
3789 Make_Component_Declaration (Loc,
3790 Defining_Identifier =>
3791 Make_Defining_Identifier (Loc, Name_uParent),
3792 Component_Definition =>
3793 Make_Component_Definition (Loc,
3794 Aliased_Present => False,
3795 Subtype_Indication => New_Reference_To (Constr_Root, Loc))));
3798 Append_To (Comp_List,
3799 Make_Component_Declaration (Loc,
3800 Defining_Identifier =>
3801 Make_Defining_Identifier (Loc,
3802 Chars => New_Internal_Name ('C')),
3803 Component_Definition =>
3804 Make_Component_Definition (Loc,
3805 Aliased_Present => False,
3806 Subtype_Indication => New_Reference_To (Str_Type, Loc))));
3808 Append_To (List_Def,
3809 Make_Full_Type_Declaration (Loc,
3810 Defining_Identifier => Equiv_Type,
3812 Make_Record_Definition (Loc,
3814 Make_Component_List (Loc,
3815 Component_Items => Comp_List,
3816 Variant_Part => Empty))));
3818 -- Suppress all checks during the analysis of the expanded code
3819 -- to avoid the generation of spurious warnings under ZFP run-time.
3821 Insert_Actions (E, List_Def, Suppress => All_Checks);
3823 end Make_CW_Equivalent_Type;
3825 ------------------------
3826 -- Make_Literal_Range --
3827 ------------------------
3829 function Make_Literal_Range
3831 Literal_Typ : Entity_Id) return Node_Id
3833 Lo : constant Node_Id :=
3834 New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
3835 Index : constant Entity_Id := Etype (Lo);
3838 Length_Expr : constant Node_Id :=
3839 Make_Op_Subtract (Loc,
3841 Make_Integer_Literal (Loc,
3842 Intval => String_Literal_Length (Literal_Typ)),
3844 Make_Integer_Literal (Loc, 1));
3847 Set_Analyzed (Lo, False);
3849 if Is_Integer_Type (Index) then
3852 Left_Opnd => New_Copy_Tree (Lo),
3853 Right_Opnd => Length_Expr);
3856 Make_Attribute_Reference (Loc,
3857 Attribute_Name => Name_Val,
3858 Prefix => New_Occurrence_Of (Index, Loc),
3859 Expressions => New_List (
3862 Make_Attribute_Reference (Loc,
3863 Attribute_Name => Name_Pos,
3864 Prefix => New_Occurrence_Of (Index, Loc),
3865 Expressions => New_List (New_Copy_Tree (Lo))),
3866 Right_Opnd => Length_Expr)));
3873 end Make_Literal_Range;
3875 ----------------------------
3876 -- Make_Subtype_From_Expr --
3877 ----------------------------
3879 -- 1. If Expr is an uncontrained array expression, creates
3880 -- Unc_Type(Expr'first(1)..Expr'Last(1),..., Expr'first(n)..Expr'last(n))
3882 -- 2. If Expr is a unconstrained discriminated type expression, creates
3883 -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
3885 -- 3. If Expr is class-wide, creates an implicit class wide subtype
3887 function Make_Subtype_From_Expr
3889 Unc_Typ : Entity_Id) return Node_Id
3891 Loc : constant Source_Ptr := Sloc (E);
3892 List_Constr : constant List_Id := New_List;
3895 Full_Subtyp : Entity_Id;
3896 Priv_Subtyp : Entity_Id;
3901 if Is_Private_Type (Unc_Typ)
3902 and then Has_Unknown_Discriminants (Unc_Typ)
3904 -- Prepare the subtype completion, Go to base type to
3905 -- find underlying type, because the type may be a generic
3906 -- actual or an explicit subtype.
3908 Utyp := Underlying_Type (Base_Type (Unc_Typ));
3909 Full_Subtyp := Make_Defining_Identifier (Loc,
3910 New_Internal_Name ('C'));
3912 Unchecked_Convert_To
3913 (Utyp, Duplicate_Subexpr_No_Checks (E));
3914 Set_Parent (Full_Exp, Parent (E));
3917 Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
3920 Make_Subtype_Declaration (Loc,
3921 Defining_Identifier => Full_Subtyp,
3922 Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
3924 -- Define the dummy private subtype
3926 Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
3927 Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ));
3928 Set_Scope (Priv_Subtyp, Full_Subtyp);
3929 Set_Is_Constrained (Priv_Subtyp);
3930 Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
3931 Set_Is_Itype (Priv_Subtyp);
3932 Set_Associated_Node_For_Itype (Priv_Subtyp, E);
3934 if Is_Tagged_Type (Priv_Subtyp) then
3936 (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
3937 Set_Primitive_Operations (Priv_Subtyp,
3938 Primitive_Operations (Unc_Typ));
3941 Set_Full_View (Priv_Subtyp, Full_Subtyp);
3943 return New_Reference_To (Priv_Subtyp, Loc);
3945 elsif Is_Array_Type (Unc_Typ) then
3946 for J in 1 .. Number_Dimensions (Unc_Typ) loop
3947 Append_To (List_Constr,
3950 Make_Attribute_Reference (Loc,
3951 Prefix => Duplicate_Subexpr_No_Checks (E),
3952 Attribute_Name => Name_First,
3953 Expressions => New_List (
3954 Make_Integer_Literal (Loc, J))),
3957 Make_Attribute_Reference (Loc,
3958 Prefix => Duplicate_Subexpr_No_Checks (E),
3959 Attribute_Name => Name_Last,
3960 Expressions => New_List (
3961 Make_Integer_Literal (Loc, J)))));
3964 elsif Is_Class_Wide_Type (Unc_Typ) then
3966 CW_Subtype : Entity_Id;
3967 EQ_Typ : Entity_Id := Empty;
3970 -- A class-wide equivalent type is not needed when VM_Target
3971 -- because the VM back-ends handle the class-wide object
3972 -- initialization itself (and doesn't need or want the
3973 -- additional intermediate type to handle the assignment).
3975 if Expander_Active and then VM_Target = No_VM then
3976 EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
3979 CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
3980 Set_Equivalent_Type (CW_Subtype, EQ_Typ);
3982 if Present (EQ_Typ) then
3983 Set_Is_Class_Wide_Equivalent_Type (EQ_Typ);
3986 Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
3988 return New_Occurrence_Of (CW_Subtype, Loc);
3991 -- Indefinite record type with discriminants
3994 D := First_Discriminant (Unc_Typ);
3995 while Present (D) loop
3996 Append_To (List_Constr,
3997 Make_Selected_Component (Loc,
3998 Prefix => Duplicate_Subexpr_No_Checks (E),
3999 Selector_Name => New_Reference_To (D, Loc)));
4001 Next_Discriminant (D);
4006 Make_Subtype_Indication (Loc,
4007 Subtype_Mark => New_Reference_To (Unc_Typ, Loc),
4009 Make_Index_Or_Discriminant_Constraint (Loc,
4010 Constraints => List_Constr));
4011 end Make_Subtype_From_Expr;
4013 -----------------------------
4014 -- May_Generate_Large_Temp --
4015 -----------------------------
4017 -- At the current time, the only types that we return False for (i.e.
4018 -- where we decide we know they cannot generate large temps) are ones
4019 -- where we know the size is 256 bits or less at compile time, and we
4020 -- are still not doing a thorough job on arrays and records ???
4022 function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
4024 if not Size_Known_At_Compile_Time (Typ) then
4027 elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then
4030 elsif Is_Array_Type (Typ)
4031 and then Present (Packed_Array_Type (Typ))
4033 return May_Generate_Large_Temp (Packed_Array_Type (Typ));
4035 -- We could do more here to find other small types ???
4040 end May_Generate_Large_Temp;
4042 ----------------------------
4043 -- New_Class_Wide_Subtype --
4044 ----------------------------
4046 function New_Class_Wide_Subtype
4047 (CW_Typ : Entity_Id;
4048 N : Node_Id) return Entity_Id
4050 Res : constant Entity_Id := Create_Itype (E_Void, N);
4051 Res_Name : constant Name_Id := Chars (Res);
4052 Res_Scope : constant Entity_Id := Scope (Res);
4055 Copy_Node (CW_Typ, Res);
4056 Set_Comes_From_Source (Res, False);
4057 Set_Sloc (Res, Sloc (N));
4059 Set_Associated_Node_For_Itype (Res, N);
4060 Set_Is_Public (Res, False); -- By default, may be changed below.
4061 Set_Public_Status (Res);
4062 Set_Chars (Res, Res_Name);
4063 Set_Scope (Res, Res_Scope);
4064 Set_Ekind (Res, E_Class_Wide_Subtype);
4065 Set_Next_Entity (Res, Empty);
4066 Set_Etype (Res, Base_Type (CW_Typ));
4068 -- For targets where front-end layout is required, reset the Is_Frozen
4069 -- status of the subtype to False (it can be implicitly set to true
4070 -- from the copy of the class-wide type). For other targets, Gigi
4071 -- doesn't want the class-wide subtype to go through the freezing
4072 -- process (though it's unclear why that causes problems and it would
4073 -- be nice to allow freezing to occur normally for all targets ???).
4075 if Frontend_Layout_On_Target then
4076 Set_Is_Frozen (Res, False);
4079 Set_Freeze_Node (Res, Empty);
4081 end New_Class_Wide_Subtype;
4083 --------------------------------
4084 -- Non_Limited_Designated_Type --
4085 ---------------------------------
4087 function Non_Limited_Designated_Type (T : Entity_Id) return Entity_Id is
4088 Desig : constant Entity_Id := Designated_Type (T);
4090 if Ekind (Desig) = E_Incomplete_Type
4091 and then Present (Non_Limited_View (Desig))
4093 return Non_Limited_View (Desig);
4097 end Non_Limited_Designated_Type;
4099 -----------------------------------
4100 -- OK_To_Do_Constant_Replacement --
4101 -----------------------------------
4103 function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is
4104 ES : constant Entity_Id := Scope (E);
4108 -- Do not replace statically allocated objects, because they may be
4109 -- modified outside the current scope.
4111 if Is_Statically_Allocated (E) then
4114 -- Do not replace aliased or volatile objects, since we don't know what
4115 -- else might change the value.
4117 elsif Is_Aliased (E) or else Treat_As_Volatile (E) then
4120 -- Debug flag -gnatdM disconnects this optimization
4122 elsif Debug_Flag_MM then
4125 -- Otherwise check scopes
4128 CS := Current_Scope;
4131 -- If we are in right scope, replacement is safe
4136 -- Packages do not affect the determination of safety
4138 elsif Ekind (CS) = E_Package then
4139 exit when CS = Standard_Standard;
4142 -- Blocks do not affect the determination of safety
4144 elsif Ekind (CS) = E_Block then
4147 -- Loops do not affect the determination of safety. Note that we
4148 -- kill all current values on entry to a loop, so we are just
4149 -- talking about processing within a loop here.
4151 elsif Ekind (CS) = E_Loop then
4154 -- Otherwise, the reference is dubious, and we cannot be sure that
4155 -- it is safe to do the replacement.
4164 end OK_To_Do_Constant_Replacement;
4166 ------------------------------------
4167 -- Possible_Bit_Aligned_Component --
4168 ------------------------------------
4170 function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is
4174 -- Case of indexed component
4176 when N_Indexed_Component =>
4178 P : constant Node_Id := Prefix (N);
4179 Ptyp : constant Entity_Id := Etype (P);
4182 -- If we know the component size and it is less than 64, then
4183 -- we are definitely OK. The back end always does assignment
4184 -- of misaligned small objects correctly.
4186 if Known_Static_Component_Size (Ptyp)
4187 and then Component_Size (Ptyp) <= 64
4191 -- Otherwise, we need to test the prefix, to see if we are
4192 -- indexing from a possibly unaligned component.
4195 return Possible_Bit_Aligned_Component (P);
4199 -- Case of selected component
4201 when N_Selected_Component =>
4203 P : constant Node_Id := Prefix (N);
4204 Comp : constant Entity_Id := Entity (Selector_Name (N));
4207 -- If there is no component clause, then we are in the clear
4208 -- since the back end will never misalign a large component
4209 -- unless it is forced to do so. In the clear means we need
4210 -- only the recursive test on the prefix.
4212 if Component_May_Be_Bit_Aligned (Comp) then
4215 return Possible_Bit_Aligned_Component (P);
4219 -- If we have neither a record nor array component, it means that we
4220 -- have fallen off the top testing prefixes recursively, and we now
4221 -- have a stand alone object, where we don't have a problem.
4227 end Possible_Bit_Aligned_Component;
4229 -------------------------
4230 -- Remove_Side_Effects --
4231 -------------------------
4233 procedure Remove_Side_Effects
4235 Name_Req : Boolean := False;
4236 Variable_Ref : Boolean := False)
4238 Loc : constant Source_Ptr := Sloc (Exp);
4239 Exp_Type : constant Entity_Id := Etype (Exp);
4240 Svg_Suppress : constant Suppress_Array := Scope_Suppress;
4242 Ref_Type : Entity_Id;
4244 Ptr_Typ_Decl : Node_Id;
4248 function Side_Effect_Free (N : Node_Id) return Boolean;
4249 -- Determines if the tree N represents an expression that is known not
4250 -- to have side effects, and for which no processing is required.
4252 function Side_Effect_Free (L : List_Id) return Boolean;
4253 -- Determines if all elements of the list L are side effect free
4255 function Safe_Prefixed_Reference (N : Node_Id) return Boolean;
4256 -- The argument N is a construct where the Prefix is dereferenced if it
4257 -- is an access type and the result is a variable. The call returns True
4258 -- if the construct is side effect free (not considering side effects in
4259 -- other than the prefix which are to be tested by the caller).
4261 function Within_In_Parameter (N : Node_Id) return Boolean;
4262 -- Determines if N is a subcomponent of a composite in-parameter. If so,
4263 -- N is not side-effect free when the actual is global and modifiable
4264 -- indirectly from within a subprogram, because it may be passed by
4265 -- reference. The front-end must be conservative here and assume that
4266 -- this may happen with any array or record type. On the other hand, we
4267 -- cannot create temporaries for all expressions for which this
4268 -- condition is true, for various reasons that might require clearing up
4269 -- ??? For example, descriminant references that appear out of place, or
4270 -- spurious type errors with class-wide expressions. As a result, we
4271 -- limit the transformation to loop bounds, which is so far the only
4272 -- case that requires it.
4274 -----------------------------
4275 -- Safe_Prefixed_Reference --
4276 -----------------------------
4278 function Safe_Prefixed_Reference (N : Node_Id) return Boolean is
4280 -- If prefix is not side effect free, definitely not safe
4282 if not Side_Effect_Free (Prefix (N)) then
4285 -- If the prefix is of an access type that is not access-to-constant,
4286 -- then this construct is a variable reference, which means it is to
4287 -- be considered to have side effects if Variable_Ref is set True
4288 -- Exception is an access to an entity that is a constant or an
4289 -- in-parameter which does not come from source, and is the result
4290 -- of a previous removal of side-effects.
4292 elsif Is_Access_Type (Etype (Prefix (N)))
4293 and then not Is_Access_Constant (Etype (Prefix (N)))
4294 and then Variable_Ref
4296 if not Is_Entity_Name (Prefix (N)) then
4299 return Ekind (Entity (Prefix (N))) = E_Constant
4300 or else Ekind (Entity (Prefix (N))) = E_In_Parameter;
4303 -- The following test is the simplest way of solving a complex
4304 -- problem uncovered by BB08-010: Side effect on loop bound that
4305 -- is a subcomponent of a global variable:
4306 -- If a loop bound is a subcomponent of a global variable, a
4307 -- modification of that variable within the loop may incorrectly
4308 -- affect the execution of the loop.
4311 (Nkind (Parent (Parent (N))) /= N_Loop_Parameter_Specification
4312 or else not Within_In_Parameter (Prefix (N)))
4316 -- All other cases are side effect free
4321 end Safe_Prefixed_Reference;
4323 ----------------------
4324 -- Side_Effect_Free --
4325 ----------------------
4327 function Side_Effect_Free (N : Node_Id) return Boolean is
4329 -- Note on checks that could raise Constraint_Error. Strictly, if
4330 -- we take advantage of 11.6, these checks do not count as side
4331 -- effects. However, we would just as soon consider that they are
4332 -- side effects, since the backend CSE does not work very well on
4333 -- expressions which can raise Constraint_Error. On the other
4334 -- hand, if we do not consider them to be side effect free, then
4335 -- we get some awkward expansions in -gnato mode, resulting in
4336 -- code insertions at a point where we do not have a clear model
4337 -- for performing the insertions. See 4908-002/comment for details.
4339 -- Special handling for entity names
4341 if Is_Entity_Name (N) then
4343 -- If the entity is a constant, it is definitely side effect
4344 -- free. Note that the test of Is_Variable (N) below might
4345 -- be expected to catch this case, but it does not, because
4346 -- this test goes to the original tree, and we may have
4347 -- already rewritten a variable node with a constant as
4348 -- a result of an earlier Force_Evaluation call.
4350 if Ekind (Entity (N)) = E_Constant
4351 or else Ekind (Entity (N)) = E_In_Parameter
4355 -- Functions are not side effect free
4357 elsif Ekind (Entity (N)) = E_Function then
4360 -- Variables are considered to be a side effect if Variable_Ref
4361 -- is set or if we have a volatile variable and Name_Req is off.
4362 -- If Name_Req is True then we can't help returning a name which
4363 -- effectively allows multiple references in any case.
4365 elsif Is_Variable (N) then
4366 return not Variable_Ref
4367 and then (not Treat_As_Volatile (Entity (N))
4370 -- Any other entity (e.g. a subtype name) is definitely side
4377 -- A value known at compile time is always side effect free
4379 elsif Compile_Time_Known_Value (N) then
4382 -- A variable renaming is not side-effet free, because the
4383 -- renaming will function like a macro in the front-end in
4384 -- some cases, and an assignment can modify the the component
4385 -- designated by N, so we need to create a temporary for it.
4387 elsif Is_Entity_Name (Original_Node (N))
4388 and then Is_Renaming_Of_Object (Entity (Original_Node (N)))
4389 and then Ekind (Entity (Original_Node (N))) /= E_Constant
4394 -- For other than entity names and compile time known values,
4395 -- check the node kind for special processing.
4399 -- An attribute reference is side effect free if its expressions
4400 -- are side effect free and its prefix is side effect free or
4401 -- is an entity reference.
4403 -- Is this right? what about x'first where x is a variable???
4405 when N_Attribute_Reference =>
4406 return Side_Effect_Free (Expressions (N))
4407 and then Attribute_Name (N) /= Name_Input
4408 and then (Is_Entity_Name (Prefix (N))
4409 or else Side_Effect_Free (Prefix (N)));
4411 -- A binary operator is side effect free if and both operands
4412 -- are side effect free. For this purpose binary operators
4413 -- include membership tests and short circuit forms
4419 return Side_Effect_Free (Left_Opnd (N))
4420 and then Side_Effect_Free (Right_Opnd (N));
4422 -- An explicit dereference is side effect free only if it is
4423 -- a side effect free prefixed reference.
4425 when N_Explicit_Dereference =>
4426 return Safe_Prefixed_Reference (N);
4428 -- A call to _rep_to_pos is side effect free, since we generate
4429 -- this pure function call ourselves. Moreover it is critically
4430 -- important to make this exception, since otherwise we can
4431 -- have discriminants in array components which don't look
4432 -- side effect free in the case of an array whose index type
4433 -- is an enumeration type with an enumeration rep clause.
4435 -- All other function calls are not side effect free
4437 when N_Function_Call =>
4438 return Nkind (Name (N)) = N_Identifier
4439 and then Is_TSS (Name (N), TSS_Rep_To_Pos)
4441 Side_Effect_Free (First (Parameter_Associations (N)));
4443 -- An indexed component is side effect free if it is a side
4444 -- effect free prefixed reference and all the indexing
4445 -- expressions are side effect free.
4447 when N_Indexed_Component =>
4448 return Side_Effect_Free (Expressions (N))
4449 and then Safe_Prefixed_Reference (N);
4451 -- A type qualification is side effect free if the expression
4452 -- is side effect free.
4454 when N_Qualified_Expression =>
4455 return Side_Effect_Free (Expression (N));
4457 -- A selected component is side effect free only if it is a
4458 -- side effect free prefixed reference. If it designates a
4459 -- component with a rep. clause it must be treated has having
4460 -- a potential side effect, because it may be modified through
4461 -- a renaming, and a subsequent use of the renaming as a macro
4462 -- will yield the wrong value. This complex interaction between
4463 -- renaming and removing side effects is a reminder that the
4464 -- latter has become a headache to maintain, and that it should
4465 -- be removed in favor of the gcc mechanism to capture values ???
4467 when N_Selected_Component =>
4468 if Nkind (Parent (N)) = N_Explicit_Dereference
4469 and then Has_Non_Standard_Rep (Designated_Type (Etype (N)))
4473 return Safe_Prefixed_Reference (N);
4476 -- A range is side effect free if the bounds are side effect free
4479 return Side_Effect_Free (Low_Bound (N))
4480 and then Side_Effect_Free (High_Bound (N));
4482 -- A slice is side effect free if it is a side effect free
4483 -- prefixed reference and the bounds are side effect free.
4486 return Side_Effect_Free (Discrete_Range (N))
4487 and then Safe_Prefixed_Reference (N);
4489 -- A type conversion is side effect free if the expression to be
4490 -- converted is side effect free.
4492 when N_Type_Conversion =>
4493 return Side_Effect_Free (Expression (N));
4495 -- A unary operator is side effect free if the operand
4496 -- is side effect free.
4499 return Side_Effect_Free (Right_Opnd (N));
4501 -- An unchecked type conversion is side effect free only if it
4502 -- is safe and its argument is side effect free.
4504 when N_Unchecked_Type_Conversion =>
4505 return Safe_Unchecked_Type_Conversion (N)
4506 and then Side_Effect_Free (Expression (N));
4508 -- An unchecked expression is side effect free if its expression
4509 -- is side effect free.
4511 when N_Unchecked_Expression =>
4512 return Side_Effect_Free (Expression (N));
4514 -- A literal is side effect free
4516 when N_Character_Literal |
4522 -- We consider that anything else has side effects. This is a bit
4523 -- crude, but we are pretty close for most common cases, and we
4524 -- are certainly correct (i.e. we never return True when the
4525 -- answer should be False).
4530 end Side_Effect_Free;
4532 -- A list is side effect free if all elements of the list are
4533 -- side effect free.
4535 function Side_Effect_Free (L : List_Id) return Boolean is
4539 if L = No_List or else L = Error_List then
4544 while Present (N) loop
4545 if not Side_Effect_Free (N) then
4554 end Side_Effect_Free;
4556 -------------------------
4557 -- Within_In_Parameter --
4558 -------------------------
4560 function Within_In_Parameter (N : Node_Id) return Boolean is
4562 if not Comes_From_Source (N) then
4565 elsif Is_Entity_Name (N) then
4566 return Ekind (Entity (N)) = E_In_Parameter;
4568 elsif Nkind (N) = N_Indexed_Component
4569 or else Nkind (N) = N_Selected_Component
4571 return Within_In_Parameter (Prefix (N));
4576 end Within_In_Parameter;
4578 -- Start of processing for Remove_Side_Effects
4581 -- If we are side effect free already or expansion is disabled,
4582 -- there is nothing to do.
4584 if Side_Effect_Free (Exp) or else not Expander_Active then
4588 -- All this must not have any checks
4590 Scope_Suppress := (others => True);
4592 -- If it is a scalar type and we need to capture the value, just make
4593 -- a copy. Likewise for a function or operator call. And if we have a
4594 -- volatile variable and Nam_Req is not set (see comments above for
4595 -- Side_Effect_Free).
4597 if Is_Elementary_Type (Exp_Type)
4598 and then (Variable_Ref
4599 or else Nkind (Exp) = N_Function_Call
4600 or else Nkind (Exp) in N_Op
4601 or else (not Name_Req
4602 and then Is_Entity_Name (Exp)
4603 and then Treat_As_Volatile (Entity (Exp))))
4605 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4606 Set_Etype (Def_Id, Exp_Type);
4607 Res := New_Reference_To (Def_Id, Loc);
4610 Make_Object_Declaration (Loc,
4611 Defining_Identifier => Def_Id,
4612 Object_Definition => New_Reference_To (Exp_Type, Loc),
4613 Constant_Present => True,
4614 Expression => Relocate_Node (Exp));
4616 Set_Assignment_OK (E);
4617 Insert_Action (Exp, E);
4619 -- If the expression has the form v.all then we can just capture
4620 -- the pointer, and then do an explicit dereference on the result.
4622 elsif Nkind (Exp) = N_Explicit_Dereference then
4624 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4626 Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc));
4629 Make_Object_Declaration (Loc,
4630 Defining_Identifier => Def_Id,
4631 Object_Definition =>
4632 New_Reference_To (Etype (Prefix (Exp)), Loc),
4633 Constant_Present => True,
4634 Expression => Relocate_Node (Prefix (Exp))));
4636 -- Similar processing for an unchecked conversion of an expression
4637 -- of the form v.all, where we want the same kind of treatment.
4639 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4640 and then Nkind (Expression (Exp)) = N_Explicit_Dereference
4642 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4643 Scope_Suppress := Svg_Suppress;
4646 -- If this is a type conversion, leave the type conversion and remove
4647 -- the side effects in the expression. This is important in several
4648 -- circumstances: for change of representations, and also when this
4649 -- is a view conversion to a smaller object, where gigi can end up
4650 -- creating its own temporary of the wrong size.
4652 elsif Nkind (Exp) = N_Type_Conversion then
4653 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4654 Scope_Suppress := Svg_Suppress;
4657 -- If this is an unchecked conversion that Gigi can't handle, make
4658 -- a copy or a use a renaming to capture the value.
4660 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4661 and then not Safe_Unchecked_Type_Conversion (Exp)
4663 if CW_Or_Controlled_Type (Exp_Type) then
4665 -- Use a renaming to capture the expression, rather than create
4666 -- a controlled temporary.
4668 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4669 Res := New_Reference_To (Def_Id, Loc);
4672 Make_Object_Renaming_Declaration (Loc,
4673 Defining_Identifier => Def_Id,
4674 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4675 Name => Relocate_Node (Exp)));
4678 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4679 Set_Etype (Def_Id, Exp_Type);
4680 Res := New_Reference_To (Def_Id, Loc);
4683 Make_Object_Declaration (Loc,
4684 Defining_Identifier => Def_Id,
4685 Object_Definition => New_Reference_To (Exp_Type, Loc),
4686 Constant_Present => not Is_Variable (Exp),
4687 Expression => Relocate_Node (Exp));
4689 Set_Assignment_OK (E);
4690 Insert_Action (Exp, E);
4693 -- For expressions that denote objects, we can use a renaming scheme.
4694 -- We skip using this if we have a volatile variable and we do not
4695 -- have Nam_Req set true (see comments above for Side_Effect_Free).
4697 elsif Is_Object_Reference (Exp)
4698 and then Nkind (Exp) /= N_Function_Call
4700 or else not Is_Entity_Name (Exp)
4701 or else not Treat_As_Volatile (Entity (Exp)))
4703 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4705 if Nkind (Exp) = N_Selected_Component
4706 and then Nkind (Prefix (Exp)) = N_Function_Call
4707 and then Is_Array_Type (Exp_Type)
4709 -- Avoid generating a variable-sized temporary, by generating
4710 -- the renaming declaration just for the function call. The
4711 -- transformation could be refined to apply only when the array
4712 -- component is constrained by a discriminant???
4715 Make_Selected_Component (Loc,
4716 Prefix => New_Occurrence_Of (Def_Id, Loc),
4717 Selector_Name => Selector_Name (Exp));
4720 Make_Object_Renaming_Declaration (Loc,
4721 Defining_Identifier => Def_Id,
4723 New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc),
4724 Name => Relocate_Node (Prefix (Exp))));
4727 Res := New_Reference_To (Def_Id, Loc);
4730 Make_Object_Renaming_Declaration (Loc,
4731 Defining_Identifier => Def_Id,
4732 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4733 Name => Relocate_Node (Exp)));
4737 -- If this is a packed reference, or a selected component with a
4738 -- non-standard representation, a reference to the temporary will
4739 -- be replaced by a copy of the original expression (see
4740 -- exp_ch2.Expand_Renaming). Otherwise the temporary must be
4741 -- elaborated by gigi, and is of course not to be replaced in-line
4742 -- by the expression it renames, which would defeat the purpose of
4743 -- removing the side-effect.
4745 if (Nkind (Exp) = N_Selected_Component
4746 or else Nkind (Exp) = N_Indexed_Component)
4747 and then Has_Non_Standard_Rep (Etype (Prefix (Exp)))
4751 Set_Is_Renaming_Of_Object (Def_Id, False);
4754 -- Otherwise we generate a reference to the value
4757 Ref_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
4760 Make_Full_Type_Declaration (Loc,
4761 Defining_Identifier => Ref_Type,
4763 Make_Access_To_Object_Definition (Loc,
4764 All_Present => True,
4765 Subtype_Indication =>
4766 New_Reference_To (Exp_Type, Loc)));
4769 Insert_Action (Exp, Ptr_Typ_Decl);
4771 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4772 Set_Etype (Def_Id, Exp_Type);
4775 Make_Explicit_Dereference (Loc,
4776 Prefix => New_Reference_To (Def_Id, Loc));
4778 if Nkind (E) = N_Explicit_Dereference then
4779 New_Exp := Relocate_Node (Prefix (E));
4781 E := Relocate_Node (E);
4782 New_Exp := Make_Reference (Loc, E);
4785 if Is_Delayed_Aggregate (E) then
4787 -- The expansion of nested aggregates is delayed until the
4788 -- enclosing aggregate is expanded. As aggregates are often
4789 -- qualified, the predicate applies to qualified expressions
4790 -- as well, indicating that the enclosing aggregate has not
4791 -- been expanded yet. At this point the aggregate is part of
4792 -- a stand-alone declaration, and must be fully expanded.
4794 if Nkind (E) = N_Qualified_Expression then
4795 Set_Expansion_Delayed (Expression (E), False);
4796 Set_Analyzed (Expression (E), False);
4798 Set_Expansion_Delayed (E, False);
4801 Set_Analyzed (E, False);
4805 Make_Object_Declaration (Loc,
4806 Defining_Identifier => Def_Id,
4807 Object_Definition => New_Reference_To (Ref_Type, Loc),
4808 Expression => New_Exp));
4811 -- Preserve the Assignment_OK flag in all copies, since at least
4812 -- one copy may be used in a context where this flag must be set
4813 -- (otherwise why would the flag be set in the first place).
4815 Set_Assignment_OK (Res, Assignment_OK (Exp));
4817 -- Finally rewrite the original expression and we are done
4820 Analyze_And_Resolve (Exp, Exp_Type);
4821 Scope_Suppress := Svg_Suppress;
4822 end Remove_Side_Effects;
4824 ---------------------------
4825 -- Represented_As_Scalar --
4826 ---------------------------
4828 function Represented_As_Scalar (T : Entity_Id) return Boolean is
4829 UT : constant Entity_Id := Underlying_Type (T);
4831 return Is_Scalar_Type (UT)
4832 or else (Is_Bit_Packed_Array (UT)
4833 and then Is_Scalar_Type (Packed_Array_Type (UT)));
4834 end Represented_As_Scalar;
4836 ------------------------------------
4837 -- Safe_Unchecked_Type_Conversion --
4838 ------------------------------------
4840 -- Note: this function knows quite a bit about the exact requirements
4841 -- of Gigi with respect to unchecked type conversions, and its code
4842 -- must be coordinated with any changes in Gigi in this area.
4844 -- The above requirements should be documented in Sinfo ???
4846 function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
4851 Pexp : constant Node_Id := Parent (Exp);
4854 -- If the expression is the RHS of an assignment or object declaration
4855 -- we are always OK because there will always be a target.
4857 -- Object renaming declarations, (generated for view conversions of
4858 -- actuals in inlined calls), like object declarations, provide an
4859 -- explicit type, and are safe as well.
4861 if (Nkind (Pexp) = N_Assignment_Statement
4862 and then Expression (Pexp) = Exp)
4863 or else Nkind (Pexp) = N_Object_Declaration
4864 or else Nkind (Pexp) = N_Object_Renaming_Declaration
4868 -- If the expression is the prefix of an N_Selected_Component
4869 -- we should also be OK because GCC knows to look inside the
4870 -- conversion except if the type is discriminated. We assume
4871 -- that we are OK anyway if the type is not set yet or if it is
4872 -- controlled since we can't afford to introduce a temporary in
4875 elsif Nkind (Pexp) = N_Selected_Component
4876 and then Prefix (Pexp) = Exp
4878 if No (Etype (Pexp)) then
4882 not Has_Discriminants (Etype (Pexp))
4883 or else Is_Constrained (Etype (Pexp));
4887 -- Set the output type, this comes from Etype if it is set, otherwise
4888 -- we take it from the subtype mark, which we assume was already
4891 if Present (Etype (Exp)) then
4892 Otyp := Etype (Exp);
4894 Otyp := Entity (Subtype_Mark (Exp));
4897 -- The input type always comes from the expression, and we assume
4898 -- this is indeed always analyzed, so we can simply get the Etype.
4900 Ityp := Etype (Expression (Exp));
4902 -- Initialize alignments to unknown so far
4907 -- Replace a concurrent type by its corresponding record type
4908 -- and each type by its underlying type and do the tests on those.
4909 -- The original type may be a private type whose completion is a
4910 -- concurrent type, so find the underlying type first.
4912 if Present (Underlying_Type (Otyp)) then
4913 Otyp := Underlying_Type (Otyp);
4916 if Present (Underlying_Type (Ityp)) then
4917 Ityp := Underlying_Type (Ityp);
4920 if Is_Concurrent_Type (Otyp) then
4921 Otyp := Corresponding_Record_Type (Otyp);
4924 if Is_Concurrent_Type (Ityp) then
4925 Ityp := Corresponding_Record_Type (Ityp);
4928 -- If the base types are the same, we know there is no problem since
4929 -- this conversion will be a noop.
4931 if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
4934 -- Same if this is an upwards conversion of an untagged type, and there
4935 -- are no constraints involved (could be more general???)
4937 elsif Etype (Ityp) = Otyp
4938 and then not Is_Tagged_Type (Ityp)
4939 and then not Has_Discriminants (Ityp)
4940 and then No (First_Rep_Item (Base_Type (Ityp)))
4944 -- If the size of output type is known at compile time, there is
4945 -- never a problem. Note that unconstrained records are considered
4946 -- to be of known size, but we can't consider them that way here,
4947 -- because we are talking about the actual size of the object.
4949 -- We also make sure that in addition to the size being known, we do
4950 -- not have a case which might generate an embarrassingly large temp
4951 -- in stack checking mode.
4953 elsif Size_Known_At_Compile_Time (Otyp)
4955 (not Stack_Checking_Enabled
4956 or else not May_Generate_Large_Temp (Otyp))
4957 and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
4961 -- If either type is tagged, then we know the alignment is OK so
4962 -- Gigi will be able to use pointer punning.
4964 elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
4967 -- If either type is a limited record type, we cannot do a copy, so
4968 -- say safe since there's nothing else we can do.
4970 elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
4973 -- Conversions to and from packed array types are always ignored and
4976 elsif Is_Packed_Array_Type (Otyp)
4977 or else Is_Packed_Array_Type (Ityp)
4982 -- The only other cases known to be safe is if the input type's
4983 -- alignment is known to be at least the maximum alignment for the
4984 -- target or if both alignments are known and the output type's
4985 -- alignment is no stricter than the input's. We can use the alignment
4986 -- of the component type of an array if a type is an unpacked
4989 if Present (Alignment_Clause (Otyp)) then
4990 Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
4992 elsif Is_Array_Type (Otyp)
4993 and then Present (Alignment_Clause (Component_Type (Otyp)))
4995 Oalign := Expr_Value (Expression (Alignment_Clause
4996 (Component_Type (Otyp))));
4999 if Present (Alignment_Clause (Ityp)) then
5000 Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
5002 elsif Is_Array_Type (Ityp)
5003 and then Present (Alignment_Clause (Component_Type (Ityp)))
5005 Ialign := Expr_Value (Expression (Alignment_Clause
5006 (Component_Type (Ityp))));
5009 if Ialign /= No_Uint and then Ialign > Maximum_Alignment then
5012 elsif Ialign /= No_Uint and then Oalign /= No_Uint
5013 and then Ialign <= Oalign
5017 -- Otherwise, Gigi cannot handle this and we must make a temporary
5022 end Safe_Unchecked_Type_Conversion;
5024 ---------------------------------
5025 -- Set_Current_Value_Condition --
5026 ---------------------------------
5028 -- Note: the implementation of this procedure is very closely tied to the
5029 -- implementation of Get_Current_Value_Condition. Here we set required
5030 -- Current_Value fields, and in Get_Current_Value_Condition, we interpret
5031 -- them, so they must have a consistent view.
5033 procedure Set_Current_Value_Condition (Cnode : Node_Id) is
5035 procedure Set_Entity_Current_Value (N : Node_Id);
5036 -- If N is an entity reference, where the entity is of an appropriate
5037 -- kind, then set the current value of this entity to Cnode, unless
5038 -- there is already a definite value set there.
5040 procedure Set_Expression_Current_Value (N : Node_Id);
5041 -- If N is of an appropriate form, sets an appropriate entry in current
5042 -- value fields of relevant entities. Multiple entities can be affected
5043 -- in the case of an AND or AND THEN.
5045 ------------------------------
5046 -- Set_Entity_Current_Value --
5047 ------------------------------
5049 procedure Set_Entity_Current_Value (N : Node_Id) is
5051 if Is_Entity_Name (N) then
5053 Ent : constant Entity_Id := Entity (N);
5056 -- Don't capture if not safe to do so
5058 if not Safe_To_Capture_Value (N, Ent, Cond => True) then
5062 -- Here we have a case where the Current_Value field may
5063 -- need to be set. We set it if it is not already set to a
5064 -- compile time expression value.
5066 -- Note that this represents a decision that one condition
5067 -- blots out another previous one. That's certainly right
5068 -- if they occur at the same level. If the second one is
5069 -- nested, then the decision is neither right nor wrong (it
5070 -- would be equally OK to leave the outer one in place, or
5071 -- take the new inner one. Really we should record both, but
5072 -- our data structures are not that elaborate.
5074 if Nkind (Current_Value (Ent)) not in N_Subexpr then
5075 Set_Current_Value (Ent, Cnode);
5079 end Set_Entity_Current_Value;
5081 ----------------------------------
5082 -- Set_Expression_Current_Value --
5083 ----------------------------------
5085 procedure Set_Expression_Current_Value (N : Node_Id) is
5091 -- Loop to deal with (ignore for now) any NOT operators present. The
5092 -- presence of NOT operators will be handled properly when we call
5093 -- Get_Current_Value_Condition.
5095 while Nkind (Cond) = N_Op_Not loop
5096 Cond := Right_Opnd (Cond);
5099 -- For an AND or AND THEN, recursively process operands
5101 if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then
5102 Set_Expression_Current_Value (Left_Opnd (Cond));
5103 Set_Expression_Current_Value (Right_Opnd (Cond));
5107 -- Check possible relational operator
5109 if Nkind (Cond) in N_Op_Compare then
5110 if Compile_Time_Known_Value (Right_Opnd (Cond)) then
5111 Set_Entity_Current_Value (Left_Opnd (Cond));
5112 elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then
5113 Set_Entity_Current_Value (Right_Opnd (Cond));
5116 -- Check possible boolean variable reference
5119 Set_Entity_Current_Value (Cond);
5121 end Set_Expression_Current_Value;
5123 -- Start of processing for Set_Current_Value_Condition
5126 Set_Expression_Current_Value (Condition (Cnode));
5127 end Set_Current_Value_Condition;
5129 --------------------------
5130 -- Set_Elaboration_Flag --
5131 --------------------------
5133 procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
5134 Loc : constant Source_Ptr := Sloc (N);
5135 Ent : constant Entity_Id := Elaboration_Entity (Spec_Id);
5139 if Present (Ent) then
5141 -- Nothing to do if at the compilation unit level, because in this
5142 -- case the flag is set by the binder generated elaboration routine.
5144 if Nkind (Parent (N)) = N_Compilation_Unit then
5147 -- Here we do need to generate an assignment statement
5150 Check_Restriction (No_Elaboration_Code, N);
5152 Make_Assignment_Statement (Loc,
5153 Name => New_Occurrence_Of (Ent, Loc),
5154 Expression => New_Occurrence_Of (Standard_True, Loc));
5156 if Nkind (Parent (N)) = N_Subunit then
5157 Insert_After (Corresponding_Stub (Parent (N)), Asn);
5159 Insert_After (N, Asn);
5164 -- Kill current value indication. This is necessary because
5165 -- the tests of this flag are inserted out of sequence and must
5166 -- not pick up bogus indications of the wrong constant value.
5168 Set_Current_Value (Ent, Empty);
5171 end Set_Elaboration_Flag;
5173 ----------------------------
5174 -- Set_Renamed_Subprogram --
5175 ----------------------------
5177 procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is
5179 -- If input node is an identifier, we can just reset it
5181 if Nkind (N) = N_Identifier then
5182 Set_Chars (N, Chars (E));
5185 -- Otherwise we have to do a rewrite, preserving Comes_From_Source
5189 CS : constant Boolean := Comes_From_Source (N);
5191 Rewrite (N, Make_Identifier (Sloc (N), Chars => Chars (E)));
5193 Set_Comes_From_Source (N, CS);
5194 Set_Analyzed (N, True);
5197 end Set_Renamed_Subprogram;
5199 --------------------------
5200 -- Target_Has_Fixed_Ops --
5201 --------------------------
5203 Integer_Sized_Small : Ureal;
5204 -- Set to 2.0 ** -(Integer'Size - 1) the first time that this
5205 -- function is called (we don't want to compute it more than once!)
5207 Long_Integer_Sized_Small : Ureal;
5208 -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this
5209 -- functoin is called (we don't want to compute it more than once)
5211 First_Time_For_THFO : Boolean := True;
5212 -- Set to False after first call (if Fractional_Fixed_Ops_On_Target)
5214 function Target_Has_Fixed_Ops
5215 (Left_Typ : Entity_Id;
5216 Right_Typ : Entity_Id;
5217 Result_Typ : Entity_Id) return Boolean
5219 function Is_Fractional_Type (Typ : Entity_Id) return Boolean;
5220 -- Return True if the given type is a fixed-point type with a small
5221 -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have
5222 -- an absolute value less than 1.0. This is currently limited
5223 -- to fixed-point types that map to Integer or Long_Integer.
5225 ------------------------
5226 -- Is_Fractional_Type --
5227 ------------------------
5229 function Is_Fractional_Type (Typ : Entity_Id) return Boolean is
5231 if Esize (Typ) = Standard_Integer_Size then
5232 return Small_Value (Typ) = Integer_Sized_Small;
5234 elsif Esize (Typ) = Standard_Long_Integer_Size then
5235 return Small_Value (Typ) = Long_Integer_Sized_Small;
5240 end Is_Fractional_Type;
5242 -- Start of processing for Target_Has_Fixed_Ops
5245 -- Return False if Fractional_Fixed_Ops_On_Target is false
5247 if not Fractional_Fixed_Ops_On_Target then
5251 -- Here the target has Fractional_Fixed_Ops, if first time, compute
5252 -- standard constants used by Is_Fractional_Type.
5254 if First_Time_For_THFO then
5255 First_Time_For_THFO := False;
5257 Integer_Sized_Small :=
5260 Den => UI_From_Int (Standard_Integer_Size - 1),
5263 Long_Integer_Sized_Small :=
5266 Den => UI_From_Int (Standard_Long_Integer_Size - 1),
5270 -- Return True if target supports fixed-by-fixed multiply/divide
5271 -- for fractional fixed-point types (see Is_Fractional_Type) and
5272 -- the operand and result types are equivalent fractional types.
5274 return Is_Fractional_Type (Base_Type (Left_Typ))
5275 and then Is_Fractional_Type (Base_Type (Right_Typ))
5276 and then Is_Fractional_Type (Base_Type (Result_Typ))
5277 and then Esize (Left_Typ) = Esize (Right_Typ)
5278 and then Esize (Left_Typ) = Esize (Result_Typ);
5279 end Target_Has_Fixed_Ops;
5281 ------------------------------------------
5282 -- Type_May_Have_Bit_Aligned_Components --
5283 ------------------------------------------
5285 function Type_May_Have_Bit_Aligned_Components
5286 (Typ : Entity_Id) return Boolean
5289 -- Array type, check component type
5291 if Is_Array_Type (Typ) then
5293 Type_May_Have_Bit_Aligned_Components (Component_Type (Typ));
5295 -- Record type, check components
5297 elsif Is_Record_Type (Typ) then
5302 E := First_Component_Or_Discriminant (Typ);
5303 while Present (E) loop
5304 if Component_May_Be_Bit_Aligned (E)
5305 or else Type_May_Have_Bit_Aligned_Components (Etype (E))
5310 Next_Component_Or_Discriminant (E);
5316 -- Type other than array or record is always OK
5321 end Type_May_Have_Bit_Aligned_Components;
5323 ----------------------------
5324 -- Wrap_Cleanup_Procedure --
5325 ----------------------------
5327 procedure Wrap_Cleanup_Procedure (N : Node_Id) is
5328 Loc : constant Source_Ptr := Sloc (N);
5329 Stseq : constant Node_Id := Handled_Statement_Sequence (N);
5330 Stmts : constant List_Id := Statements (Stseq);
5333 if Abort_Allowed then
5334 Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
5335 Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));
5337 end Wrap_Cleanup_Procedure;