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 Entity_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
1388 Next_Elmt (AI_Elmt);
1391 end Find_Secondary_Table;
1393 -- Start of processing for Find_Interface_ADT
1396 pragma Assert (Is_Interface (Iface));
1398 -- Handle private types
1400 if Has_Private_Declaration (Typ)
1401 and then Present (Full_View (Typ))
1403 Typ := Full_View (Typ);
1406 -- Handle access types
1408 if Is_Access_Type (Typ) then
1409 Typ := Directly_Designated_Type (Typ);
1412 -- Handle task and protected types implementing interfaces
1414 if Is_Concurrent_Type (Typ) then
1415 Typ := Corresponding_Record_Type (Typ);
1419 (not Is_Class_Wide_Type (Typ)
1420 and then Ekind (Typ) /= E_Incomplete_Type);
1422 ADT := Next_Elmt (First_Elmt (Access_Disp_Table (Typ)));
1423 pragma Assert (Present (Node (ADT)));
1424 Find_Secondary_Table (Typ);
1425 pragma Assert (Found);
1427 end Find_Interface_ADT;
1429 ------------------------
1430 -- Find_Interface_Tag --
1431 ------------------------
1433 function Find_Interface_Tag
1435 Iface : Entity_Id) return Entity_Id
1438 Found : Boolean := False;
1439 Typ : Entity_Id := T;
1441 Is_Primary_Tag : Boolean := False;
1443 Is_Sync_Typ : Boolean := False;
1444 -- In case of non concurrent-record-types each parent-type has the
1445 -- tags associated with the interface types that are not implemented
1446 -- by the ancestors; concurrent-record-types have their whole list of
1447 -- interface tags (and this case requires some special management).
1449 procedure Find_Tag (Typ : Entity_Id);
1450 -- Internal subprogram used to recursively climb to the ancestors
1456 procedure Find_Tag (Typ : Entity_Id) is
1461 -- Check if the interface is an immediate ancestor of the type and
1462 -- therefore shares the main tag.
1466 Is_Primary_Tag := True;
1469 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1470 AI_Tag := First_Tag_Component (Typ);
1477 -- Handle synchronized interface derivations
1479 if Is_Concurrent_Record_Type (Typ) then
1481 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1483 if Is_Non_Empty_List (Iface_List) then
1484 Find_Tag (Etype (First (Iface_List)));
1488 -- Climb to the root type handling private types
1490 elsif Present (Full_View (Etype (Typ))) then
1491 if Full_View (Etype (Typ)) /= Typ then
1492 Find_Tag (Full_View (Etype (Typ)));
1495 elsif Etype (Typ) /= Typ then
1496 Find_Tag (Etype (Typ));
1499 -- Traverse the list of interfaces implemented by the type
1502 and then Present (Abstract_Interfaces (Typ))
1503 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1505 -- Skip the tag associated with the primary table
1507 if not Is_Sync_Typ then
1509 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1510 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1511 pragma Assert (Present (AI_Tag));
1514 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1515 while Present (AI_Elmt) loop
1516 AI := Node (AI_Elmt);
1518 if AI = Iface or else Is_Ancestor (Iface, AI) then
1523 AI_Tag := Next_Tag_Component (AI_Tag);
1524 Next_Elmt (AI_Elmt);
1529 -- Start of processing for Find_Interface_Tag
1532 pragma Assert (Is_Interface (Iface));
1534 -- Handle private types
1536 if Has_Private_Declaration (Typ)
1537 and then Present (Full_View (Typ))
1539 Typ := Full_View (Typ);
1542 -- Handle access types
1544 if Is_Access_Type (Typ) then
1545 Typ := Directly_Designated_Type (Typ);
1548 -- Handle task and protected types implementing interfaces
1550 if Is_Concurrent_Type (Typ) then
1551 Typ := Corresponding_Record_Type (Typ);
1554 if Is_Class_Wide_Type (Typ) then
1558 -- Handle entities from the limited view
1560 if Ekind (Typ) = E_Incomplete_Type then
1561 pragma Assert (Present (Non_Limited_View (Typ)));
1562 Typ := Non_Limited_View (Typ);
1565 if not Is_Concurrent_Record_Type (Typ) then
1567 pragma Assert (Found);
1570 -- Concurrent record types
1573 Is_Sync_Typ := True;
1574 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1576 pragma Assert (Found);
1578 if Is_Primary_Tag then
1579 return First_Tag_Component (Typ);
1584 end Find_Interface_Tag;
1586 --------------------
1587 -- Find_Interface --
1588 --------------------
1590 function Find_Interface
1592 Comp : Entity_Id) return Entity_Id
1595 Found : Boolean := False;
1597 Typ : Entity_Id := T;
1599 Is_Sync_Typ : Boolean := False;
1600 -- In case of non concurrent-record-types each parent-type has the
1601 -- tags associated with the interface types that are not implemented
1602 -- by the ancestors; concurrent-record-types have their whole list of
1603 -- interface tags (and this case requires some special management).
1605 procedure Find_Iface (Typ : Entity_Id);
1606 -- Internal subprogram used to recursively climb to the ancestors
1612 procedure Find_Iface (Typ : Entity_Id) is
1616 -- Climb to the root type
1618 -- Handle sychronized interface derivations
1620 if Is_Concurrent_Record_Type (Typ) then
1622 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1624 if Is_Non_Empty_List (Iface_List) then
1625 Find_Iface (Etype (First (Iface_List)));
1629 -- Handle the common case
1631 elsif Etype (Typ) /= Typ then
1632 pragma Assert (not Present (Full_View (Etype (Typ))));
1633 Find_Iface (Etype (Typ));
1636 -- Traverse the list of interfaces implemented by the type
1639 and then Present (Abstract_Interfaces (Typ))
1640 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1642 -- Skip the tag associated with the primary table
1644 if not Is_Sync_Typ then
1646 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1647 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1648 pragma Assert (Present (AI_Tag));
1651 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1652 while Present (AI_Elmt) loop
1653 if AI_Tag = Comp then
1654 Iface := Node (AI_Elmt);
1659 AI_Tag := Next_Tag_Component (AI_Tag);
1660 Next_Elmt (AI_Elmt);
1665 -- Start of processing for Find_Interface
1668 -- Handle private types
1670 if Has_Private_Declaration (Typ)
1671 and then Present (Full_View (Typ))
1673 Typ := Full_View (Typ);
1676 -- Handle access types
1678 if Is_Access_Type (Typ) then
1679 Typ := Directly_Designated_Type (Typ);
1682 -- Handle task and protected types implementing interfaces
1684 if Is_Concurrent_Type (Typ) then
1685 Typ := Corresponding_Record_Type (Typ);
1688 if Is_Class_Wide_Type (Typ) then
1692 -- Handle entities from the limited view
1694 if Ekind (Typ) = E_Incomplete_Type then
1695 pragma Assert (Present (Non_Limited_View (Typ)));
1696 Typ := Non_Limited_View (Typ);
1699 if Is_Concurrent_Record_Type (Typ) then
1700 Is_Sync_Typ := True;
1701 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1705 pragma Assert (Found);
1713 function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is
1715 Typ : Entity_Id := T;
1719 if Is_Class_Wide_Type (Typ) then
1720 Typ := Root_Type (Typ);
1723 Typ := Underlying_Type (Typ);
1725 -- Loop through primitive operations
1727 Prim := First_Elmt (Primitive_Operations (Typ));
1728 while Present (Prim) loop
1731 -- We can retrieve primitive operations by name if it is an internal
1732 -- name. For equality we must check that both of its operands have
1733 -- the same type, to avoid confusion with user-defined equalities
1734 -- than may have a non-symmetric signature.
1736 exit when Chars (Op) = Name
1739 or else Etype (First_Entity (Op)) = Etype (Last_Entity (Op)));
1742 pragma Assert (Present (Prim));
1752 function Find_Prim_Op
1754 Name : TSS_Name_Type) return Entity_Id
1757 Typ : Entity_Id := T;
1760 if Is_Class_Wide_Type (Typ) then
1761 Typ := Root_Type (Typ);
1764 Typ := Underlying_Type (Typ);
1766 Prim := First_Elmt (Primitive_Operations (Typ));
1767 while not Is_TSS (Node (Prim), Name) loop
1769 pragma Assert (Present (Prim));
1775 ----------------------
1776 -- Force_Evaluation --
1777 ----------------------
1779 procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is
1781 Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True);
1782 end Force_Evaluation;
1784 ------------------------
1785 -- Generate_Poll_Call --
1786 ------------------------
1788 procedure Generate_Poll_Call (N : Node_Id) is
1790 -- No poll call if polling not active
1792 if not Polling_Required then
1795 -- Otherwise generate require poll call
1798 Insert_Before_And_Analyze (N,
1799 Make_Procedure_Call_Statement (Sloc (N),
1800 Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N))));
1802 end Generate_Poll_Call;
1804 ---------------------------------
1805 -- Get_Current_Value_Condition --
1806 ---------------------------------
1808 -- Note: the implementation of this procedure is very closely tied to the
1809 -- implementation of Set_Current_Value_Condition. In the Get procedure, we
1810 -- interpret Current_Value fields set by the Set procedure, so the two
1811 -- procedures need to be closely coordinated.
1813 procedure Get_Current_Value_Condition
1818 Loc : constant Source_Ptr := Sloc (Var);
1819 Ent : constant Entity_Id := Entity (Var);
1821 procedure Process_Current_Value_Condition
1824 -- N is an expression which holds either True (S = True) or False (S =
1825 -- False) in the condition. This procedure digs out the expression and
1826 -- if it refers to Ent, sets Op and Val appropriately.
1828 -------------------------------------
1829 -- Process_Current_Value_Condition --
1830 -------------------------------------
1832 procedure Process_Current_Value_Condition
1843 -- Deal with NOT operators, inverting sense
1845 while Nkind (Cond) = N_Op_Not loop
1846 Cond := Right_Opnd (Cond);
1850 -- Deal with AND THEN and AND cases
1852 if Nkind (Cond) = N_And_Then
1853 or else Nkind (Cond) = N_Op_And
1855 -- Don't ever try to invert a condition that is of the form
1856 -- of an AND or AND THEN (since we are not doing sufficiently
1857 -- general processing to allow this).
1859 if Sens = False then
1865 -- Recursively process AND and AND THEN branches
1867 Process_Current_Value_Condition (Left_Opnd (Cond), True);
1869 if Op /= N_Empty then
1873 Process_Current_Value_Condition (Right_Opnd (Cond), True);
1876 -- Case of relational operator
1878 elsif Nkind (Cond) in N_Op_Compare then
1881 -- Invert sense of test if inverted test
1883 if Sens = False then
1885 when N_Op_Eq => Op := N_Op_Ne;
1886 when N_Op_Ne => Op := N_Op_Eq;
1887 when N_Op_Lt => Op := N_Op_Ge;
1888 when N_Op_Gt => Op := N_Op_Le;
1889 when N_Op_Le => Op := N_Op_Gt;
1890 when N_Op_Ge => Op := N_Op_Lt;
1891 when others => raise Program_Error;
1895 -- Case of entity op value
1897 if Is_Entity_Name (Left_Opnd (Cond))
1898 and then Ent = Entity (Left_Opnd (Cond))
1899 and then Compile_Time_Known_Value (Right_Opnd (Cond))
1901 Val := Right_Opnd (Cond);
1903 -- Case of value op entity
1905 elsif Is_Entity_Name (Right_Opnd (Cond))
1906 and then Ent = Entity (Right_Opnd (Cond))
1907 and then Compile_Time_Known_Value (Left_Opnd (Cond))
1909 Val := Left_Opnd (Cond);
1911 -- We are effectively swapping operands
1914 when N_Op_Eq => null;
1915 when N_Op_Ne => null;
1916 when N_Op_Lt => Op := N_Op_Gt;
1917 when N_Op_Gt => Op := N_Op_Lt;
1918 when N_Op_Le => Op := N_Op_Ge;
1919 when N_Op_Ge => Op := N_Op_Le;
1920 when others => raise Program_Error;
1929 -- Case of Boolean variable reference, return as though the
1930 -- reference had said var = True.
1933 if Is_Entity_Name (Cond)
1934 and then Ent = Entity (Cond)
1936 Val := New_Occurrence_Of (Standard_True, Sloc (Cond));
1938 if Sens = False then
1945 end Process_Current_Value_Condition;
1947 -- Start of processing for Get_Current_Value_Condition
1953 -- Immediate return, nothing doing, if this is not an object
1955 if Ekind (Ent) not in Object_Kind then
1959 -- Otherwise examine current value
1962 CV : constant Node_Id := Current_Value (Ent);
1967 -- If statement. Condition is known true in THEN section, known False
1968 -- in any ELSIF or ELSE part, and unknown outside the IF statement.
1970 if Nkind (CV) = N_If_Statement then
1972 -- Before start of IF statement
1974 if Loc < Sloc (CV) then
1977 -- After end of IF statement
1979 elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
1983 -- At this stage we know that we are within the IF statement, but
1984 -- unfortunately, the tree does not record the SLOC of the ELSE so
1985 -- we cannot use a simple SLOC comparison to distinguish between
1986 -- the then/else statements, so we have to climb the tree.
1993 while Parent (N) /= CV loop
1996 -- If we fall off the top of the tree, then that's odd, but
1997 -- perhaps it could occur in some error situation, and the
1998 -- safest response is simply to assume that the outcome of
1999 -- the condition is unknown. No point in bombing during an
2000 -- attempt to optimize things.
2007 -- Now we have N pointing to a node whose parent is the IF
2008 -- statement in question, so now we can tell if we are within
2009 -- the THEN statements.
2011 if Is_List_Member (N)
2012 and then List_Containing (N) = Then_Statements (CV)
2016 -- If the variable reference does not come from source, we
2017 -- cannot reliably tell whether it appears in the else part.
2018 -- In particular, if if appears in generated code for a node
2019 -- that requires finalization, it may be attached to a list
2020 -- that has not been yet inserted into the code. For now,
2021 -- treat it as unknown.
2023 elsif not Comes_From_Source (N) then
2026 -- Otherwise we must be in ELSIF or ELSE part
2033 -- ELSIF part. Condition is known true within the referenced
2034 -- ELSIF, known False in any subsequent ELSIF or ELSE part, and
2035 -- unknown before the ELSE part or after the IF statement.
2037 elsif Nkind (CV) = N_Elsif_Part then
2040 -- Before start of ELSIF part
2042 if Loc < Sloc (CV) then
2045 -- After end of IF statement
2047 elsif Loc >= Sloc (Stm) +
2048 Text_Ptr (UI_To_Int (End_Span (Stm)))
2053 -- Again we lack the SLOC of the ELSE, so we need to climb the
2054 -- tree to see if we are within the ELSIF part in question.
2061 while Parent (N) /= Stm loop
2064 -- If we fall off the top of the tree, then that's odd, but
2065 -- perhaps it could occur in some error situation, and the
2066 -- safest response is simply to assume that the outcome of
2067 -- the condition is unknown. No point in bombing during an
2068 -- attempt to optimize things.
2075 -- Now we have N pointing to a node whose parent is the IF
2076 -- statement in question, so see if is the ELSIF part we want.
2077 -- the THEN statements.
2082 -- Otherwise we must be in susbequent ELSIF or ELSE part
2089 -- Iteration scheme of while loop. The condition is known to be
2090 -- true within the body of the loop.
2092 elsif Nkind (CV) = N_Iteration_Scheme then
2094 Loop_Stmt : constant Node_Id := Parent (CV);
2097 -- Before start of body of loop
2099 if Loc < Sloc (Loop_Stmt) then
2102 -- After end of LOOP statement
2104 elsif Loc >= Sloc (End_Label (Loop_Stmt)) then
2107 -- We are within the body of the loop
2114 -- All other cases of Current_Value settings
2120 -- If we fall through here, then we have a reportable condition, Sens
2121 -- is True if the condition is true and False if it needs inverting.
2123 Process_Current_Value_Condition (Condition (CV), Sens);
2125 end Get_Current_Value_Condition;
2127 ---------------------------------
2128 -- Has_Controlled_Coextensions --
2129 ---------------------------------
2131 function Has_Controlled_Coextensions (Typ : Entity_Id) return Boolean is
2136 -- Only consider record types
2138 if Ekind (Typ) /= E_Record_Type
2139 and then Ekind (Typ) /= E_Record_Subtype
2144 if Has_Discriminants (Typ) then
2145 Discr := First_Discriminant (Typ);
2146 while Present (Discr) loop
2147 D_Typ := Etype (Discr);
2149 if Ekind (D_Typ) = E_Anonymous_Access_Type
2151 (Is_Controlled (Directly_Designated_Type (D_Typ))
2153 Is_Concurrent_Type (Directly_Designated_Type (D_Typ)))
2158 Next_Discriminant (Discr);
2163 end Has_Controlled_Coextensions;
2165 --------------------
2166 -- Homonym_Number --
2167 --------------------
2169 function Homonym_Number (Subp : Entity_Id) return Nat is
2175 Hom := Homonym (Subp);
2176 while Present (Hom) loop
2177 if Scope (Hom) = Scope (Subp) then
2181 Hom := Homonym (Hom);
2187 ------------------------------
2188 -- In_Unconditional_Context --
2189 ------------------------------
2191 function In_Unconditional_Context (Node : Node_Id) return Boolean is
2196 while Present (P) loop
2198 when N_Subprogram_Body =>
2201 when N_If_Statement =>
2204 when N_Loop_Statement =>
2207 when N_Case_Statement =>
2216 end In_Unconditional_Context;
2222 procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is
2224 if Present (Ins_Action) then
2225 Insert_Actions (Assoc_Node, New_List (Ins_Action));
2229 -- Version with check(s) suppressed
2231 procedure Insert_Action
2232 (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id)
2235 Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress);
2238 --------------------
2239 -- Insert_Actions --
2240 --------------------
2242 procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is
2246 Wrapped_Node : Node_Id := Empty;
2249 if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
2253 -- Ignore insert of actions from inside default expression in the
2254 -- special preliminary analyze mode. Any insertions at this point
2255 -- have no relevance, since we are only doing the analyze to freeze
2256 -- the types of any static expressions. See section "Handling of
2257 -- Default Expressions" in the spec of package Sem for further details.
2259 if In_Default_Expression then
2263 -- If the action derives from stuff inside a record, then the actions
2264 -- are attached to the current scope, to be inserted and analyzed on
2265 -- exit from the scope. The reason for this is that we may also
2266 -- be generating freeze actions at the same time, and they must
2267 -- eventually be elaborated in the correct order.
2269 if Is_Record_Type (Current_Scope)
2270 and then not Is_Frozen (Current_Scope)
2272 if No (Scope_Stack.Table
2273 (Scope_Stack.Last).Pending_Freeze_Actions)
2275 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
2280 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
2286 -- We now intend to climb up the tree to find the right point to
2287 -- insert the actions. We start at Assoc_Node, unless this node is
2288 -- a subexpression in which case we start with its parent. We do this
2289 -- for two reasons. First it speeds things up. Second, if Assoc_Node
2290 -- is itself one of the special nodes like N_And_Then, then we assume
2291 -- that an initial request to insert actions for such a node does not
2292 -- expect the actions to get deposited in the node for later handling
2293 -- when the node is expanded, since clearly the node is being dealt
2294 -- with by the caller. Note that in the subexpression case, N is
2295 -- always the child we came from.
2297 -- N_Raise_xxx_Error is an annoying special case, it is a statement
2298 -- if it has type Standard_Void_Type, and a subexpression otherwise.
2299 -- otherwise. Procedure attribute references are also statements.
2301 if Nkind (Assoc_Node) in N_Subexpr
2302 and then (Nkind (Assoc_Node) in N_Raise_xxx_Error
2303 or else Etype (Assoc_Node) /= Standard_Void_Type)
2304 and then (Nkind (Assoc_Node) /= N_Attribute_Reference
2306 not Is_Procedure_Attribute_Name
2307 (Attribute_Name (Assoc_Node)))
2309 P := Assoc_Node; -- ??? does not agree with above!
2310 N := Parent (Assoc_Node);
2312 -- Non-subexpression case. Note that N is initially Empty in this
2313 -- case (N is only guaranteed Non-Empty in the subexpr case).
2320 -- Capture root of the transient scope
2322 if Scope_Is_Transient then
2323 Wrapped_Node := Node_To_Be_Wrapped;
2327 pragma Assert (Present (P));
2331 -- Case of right operand of AND THEN or OR ELSE. Put the actions
2332 -- in the Actions field of the right operand. They will be moved
2333 -- out further when the AND THEN or OR ELSE operator is expanded.
2334 -- Nothing special needs to be done for the left operand since
2335 -- in that case the actions are executed unconditionally.
2337 when N_And_Then | N_Or_Else =>
2338 if N = Right_Opnd (P) then
2339 if Present (Actions (P)) then
2340 Insert_List_After_And_Analyze
2341 (Last (Actions (P)), Ins_Actions);
2343 Set_Actions (P, Ins_Actions);
2344 Analyze_List (Actions (P));
2350 -- Then or Else operand of conditional expression. Add actions to
2351 -- Then_Actions or Else_Actions field as appropriate. The actions
2352 -- will be moved further out when the conditional is expanded.
2354 when N_Conditional_Expression =>
2356 ThenX : constant Node_Id := Next (First (Expressions (P)));
2357 ElseX : constant Node_Id := Next (ThenX);
2360 -- Actions belong to the then expression, temporarily
2361 -- place them as Then_Actions of the conditional expr.
2362 -- They will be moved to the proper place later when
2363 -- the conditional expression is expanded.
2366 if Present (Then_Actions (P)) then
2367 Insert_List_After_And_Analyze
2368 (Last (Then_Actions (P)), Ins_Actions);
2370 Set_Then_Actions (P, Ins_Actions);
2371 Analyze_List (Then_Actions (P));
2376 -- Actions belong to the else expression, temporarily
2377 -- place them as Else_Actions of the conditional expr.
2378 -- They will be moved to the proper place later when
2379 -- the conditional expression is expanded.
2381 elsif N = ElseX then
2382 if Present (Else_Actions (P)) then
2383 Insert_List_After_And_Analyze
2384 (Last (Else_Actions (P)), Ins_Actions);
2386 Set_Else_Actions (P, Ins_Actions);
2387 Analyze_List (Else_Actions (P));
2392 -- Actions belong to the condition. In this case they are
2393 -- unconditionally executed, and so we can continue the
2394 -- search for the proper insert point.
2401 -- Case of appearing in the condition of a while expression or
2402 -- elsif. We insert the actions into the Condition_Actions field.
2403 -- They will be moved further out when the while loop or elsif
2406 when N_Iteration_Scheme |
2409 if N = Condition (P) then
2410 if Present (Condition_Actions (P)) then
2411 Insert_List_After_And_Analyze
2412 (Last (Condition_Actions (P)), Ins_Actions);
2414 Set_Condition_Actions (P, Ins_Actions);
2416 -- Set the parent of the insert actions explicitly.
2417 -- This is not a syntactic field, but we need the
2418 -- parent field set, in particular so that freeze
2419 -- can understand that it is dealing with condition
2420 -- actions, and properly insert the freezing actions.
2422 Set_Parent (Ins_Actions, P);
2423 Analyze_List (Condition_Actions (P));
2429 -- Statements, declarations, pragmas, representation clauses
2434 N_Procedure_Call_Statement |
2435 N_Statement_Other_Than_Procedure_Call |
2441 -- Representation_Clause
2444 N_Attribute_Definition_Clause |
2445 N_Enumeration_Representation_Clause |
2446 N_Record_Representation_Clause |
2450 N_Abstract_Subprogram_Declaration |
2452 N_Exception_Declaration |
2453 N_Exception_Renaming_Declaration |
2454 N_Formal_Abstract_Subprogram_Declaration |
2455 N_Formal_Concrete_Subprogram_Declaration |
2456 N_Formal_Object_Declaration |
2457 N_Formal_Type_Declaration |
2458 N_Full_Type_Declaration |
2459 N_Function_Instantiation |
2460 N_Generic_Function_Renaming_Declaration |
2461 N_Generic_Package_Declaration |
2462 N_Generic_Package_Renaming_Declaration |
2463 N_Generic_Procedure_Renaming_Declaration |
2464 N_Generic_Subprogram_Declaration |
2465 N_Implicit_Label_Declaration |
2466 N_Incomplete_Type_Declaration |
2467 N_Number_Declaration |
2468 N_Object_Declaration |
2469 N_Object_Renaming_Declaration |
2471 N_Package_Body_Stub |
2472 N_Package_Declaration |
2473 N_Package_Instantiation |
2474 N_Package_Renaming_Declaration |
2475 N_Private_Extension_Declaration |
2476 N_Private_Type_Declaration |
2477 N_Procedure_Instantiation |
2479 N_Protected_Body_Stub |
2480 N_Protected_Type_Declaration |
2481 N_Single_Task_Declaration |
2483 N_Subprogram_Body_Stub |
2484 N_Subprogram_Declaration |
2485 N_Subprogram_Renaming_Declaration |
2486 N_Subtype_Declaration |
2489 N_Task_Type_Declaration |
2491 -- Freeze entity behaves like a declaration or statement
2495 -- Do not insert here if the item is not a list member (this
2496 -- happens for example with a triggering statement, and the
2497 -- proper approach is to insert before the entire select).
2499 if not Is_List_Member (P) then
2502 -- Do not insert if parent of P is an N_Component_Association
2503 -- node (i.e. we are in the context of an N_Aggregate or
2504 -- N_Extension_Aggregate node. In this case we want to insert
2505 -- before the entire aggregate.
2507 elsif Nkind (Parent (P)) = N_Component_Association then
2510 -- Do not insert if the parent of P is either an N_Variant
2511 -- node or an N_Record_Definition node, meaning in either
2512 -- case that P is a member of a component list, and that
2513 -- therefore the actions should be inserted outside the
2514 -- complete record declaration.
2516 elsif Nkind (Parent (P)) = N_Variant
2517 or else Nkind (Parent (P)) = N_Record_Definition
2521 -- Do not insert freeze nodes within the loop generated for
2522 -- an aggregate, because they may be elaborated too late for
2523 -- subsequent use in the back end: within a package spec the
2524 -- loop is part of the elaboration procedure and is only
2525 -- elaborated during the second pass.
2526 -- If the loop comes from source, or the entity is local to
2527 -- the loop itself it must remain within.
2529 elsif Nkind (Parent (P)) = N_Loop_Statement
2530 and then not Comes_From_Source (Parent (P))
2531 and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
2533 Scope (Entity (First (Ins_Actions))) /= Current_Scope
2537 -- Otherwise we can go ahead and do the insertion
2539 elsif P = Wrapped_Node then
2540 Store_Before_Actions_In_Scope (Ins_Actions);
2544 Insert_List_Before_And_Analyze (P, Ins_Actions);
2548 -- A special case, N_Raise_xxx_Error can act either as a
2549 -- statement or a subexpression. We tell the difference
2550 -- by looking at the Etype. It is set to Standard_Void_Type
2551 -- in the statement case.
2554 N_Raise_xxx_Error =>
2555 if Etype (P) = Standard_Void_Type then
2556 if P = Wrapped_Node then
2557 Store_Before_Actions_In_Scope (Ins_Actions);
2559 Insert_List_Before_And_Analyze (P, Ins_Actions);
2564 -- In the subexpression case, keep climbing
2570 -- If a component association appears within a loop created for
2571 -- an array aggregate, attach the actions to the association so
2572 -- they can be subsequently inserted within the loop. For other
2573 -- component associations insert outside of the aggregate. For
2574 -- an association that will generate a loop, its Loop_Actions
2575 -- attribute is already initialized (see exp_aggr.adb).
2577 -- The list of loop_actions can in turn generate additional ones,
2578 -- that are inserted before the associated node. If the associated
2579 -- node is outside the aggregate, the new actions are collected
2580 -- at the end of the loop actions, to respect the order in which
2581 -- they are to be elaborated.
2584 N_Component_Association =>
2585 if Nkind (Parent (P)) = N_Aggregate
2586 and then Present (Loop_Actions (P))
2588 if Is_Empty_List (Loop_Actions (P)) then
2589 Set_Loop_Actions (P, Ins_Actions);
2590 Analyze_List (Ins_Actions);
2597 -- Check whether these actions were generated
2598 -- by a declaration that is part of the loop_
2599 -- actions for the component_association.
2602 while Present (Decl) loop
2603 exit when Parent (Decl) = P
2604 and then Is_List_Member (Decl)
2606 List_Containing (Decl) = Loop_Actions (P);
2607 Decl := Parent (Decl);
2610 if Present (Decl) then
2611 Insert_List_Before_And_Analyze
2612 (Decl, Ins_Actions);
2614 Insert_List_After_And_Analyze
2615 (Last (Loop_Actions (P)), Ins_Actions);
2626 -- Another special case, an attribute denoting a procedure call
2629 N_Attribute_Reference =>
2630 if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
2631 if P = Wrapped_Node then
2632 Store_Before_Actions_In_Scope (Ins_Actions);
2634 Insert_List_Before_And_Analyze (P, Ins_Actions);
2639 -- In the subexpression case, keep climbing
2645 -- For all other node types, keep climbing tree
2649 N_Accept_Alternative |
2650 N_Access_Definition |
2651 N_Access_Function_Definition |
2652 N_Access_Procedure_Definition |
2653 N_Access_To_Object_Definition |
2656 N_Case_Statement_Alternative |
2657 N_Character_Literal |
2658 N_Compilation_Unit |
2659 N_Compilation_Unit_Aux |
2660 N_Component_Clause |
2661 N_Component_Declaration |
2662 N_Component_Definition |
2664 N_Constrained_Array_Definition |
2665 N_Decimal_Fixed_Point_Definition |
2666 N_Defining_Character_Literal |
2667 N_Defining_Identifier |
2668 N_Defining_Operator_Symbol |
2669 N_Defining_Program_Unit_Name |
2670 N_Delay_Alternative |
2671 N_Delta_Constraint |
2672 N_Derived_Type_Definition |
2674 N_Digits_Constraint |
2675 N_Discriminant_Association |
2676 N_Discriminant_Specification |
2678 N_Entry_Body_Formal_Part |
2679 N_Entry_Call_Alternative |
2680 N_Entry_Declaration |
2681 N_Entry_Index_Specification |
2682 N_Enumeration_Type_Definition |
2684 N_Exception_Handler |
2686 N_Explicit_Dereference |
2687 N_Extension_Aggregate |
2688 N_Floating_Point_Definition |
2689 N_Formal_Decimal_Fixed_Point_Definition |
2690 N_Formal_Derived_Type_Definition |
2691 N_Formal_Discrete_Type_Definition |
2692 N_Formal_Floating_Point_Definition |
2693 N_Formal_Modular_Type_Definition |
2694 N_Formal_Ordinary_Fixed_Point_Definition |
2695 N_Formal_Package_Declaration |
2696 N_Formal_Private_Type_Definition |
2697 N_Formal_Signed_Integer_Type_Definition |
2699 N_Function_Specification |
2700 N_Generic_Association |
2701 N_Handled_Sequence_Of_Statements |
2704 N_Index_Or_Discriminant_Constraint |
2705 N_Indexed_Component |
2709 N_Loop_Parameter_Specification |
2711 N_Modular_Type_Definition |
2737 N_Op_Shift_Right_Arithmetic |
2741 N_Ordinary_Fixed_Point_Definition |
2743 N_Package_Specification |
2744 N_Parameter_Association |
2745 N_Parameter_Specification |
2746 N_Pop_Constraint_Error_Label |
2747 N_Pop_Program_Error_Label |
2748 N_Pop_Storage_Error_Label |
2749 N_Pragma_Argument_Association |
2750 N_Procedure_Specification |
2751 N_Protected_Definition |
2752 N_Push_Constraint_Error_Label |
2753 N_Push_Program_Error_Label |
2754 N_Push_Storage_Error_Label |
2755 N_Qualified_Expression |
2757 N_Range_Constraint |
2759 N_Real_Range_Specification |
2760 N_Record_Definition |
2762 N_Selected_Component |
2763 N_Signed_Integer_Type_Definition |
2764 N_Single_Protected_Declaration |
2768 N_Subtype_Indication |
2771 N_Terminate_Alternative |
2772 N_Triggering_Alternative |
2774 N_Unchecked_Expression |
2775 N_Unchecked_Type_Conversion |
2776 N_Unconstrained_Array_Definition |
2779 N_Use_Package_Clause |
2783 N_Validate_Unchecked_Conversion |
2790 -- Make sure that inserted actions stay in the transient scope
2792 if P = Wrapped_Node then
2793 Store_Before_Actions_In_Scope (Ins_Actions);
2797 -- If we fall through above tests, keep climbing tree
2801 if Nkind (Parent (N)) = N_Subunit then
2803 -- This is the proper body corresponding to a stub. Insertion
2804 -- must be done at the point of the stub, which is in the decla-
2805 -- tive part of the parent unit.
2807 P := Corresponding_Stub (Parent (N));
2815 -- Version with check(s) suppressed
2817 procedure Insert_Actions
2818 (Assoc_Node : Node_Id;
2819 Ins_Actions : List_Id;
2820 Suppress : Check_Id)
2823 if Suppress = All_Checks then
2825 Svg : constant Suppress_Array := Scope_Suppress;
2827 Scope_Suppress := (others => True);
2828 Insert_Actions (Assoc_Node, Ins_Actions);
2829 Scope_Suppress := Svg;
2834 Svg : constant Boolean := Scope_Suppress (Suppress);
2836 Scope_Suppress (Suppress) := True;
2837 Insert_Actions (Assoc_Node, Ins_Actions);
2838 Scope_Suppress (Suppress) := Svg;
2843 --------------------------
2844 -- Insert_Actions_After --
2845 --------------------------
2847 procedure Insert_Actions_After
2848 (Assoc_Node : Node_Id;
2849 Ins_Actions : List_Id)
2852 if Scope_Is_Transient
2853 and then Assoc_Node = Node_To_Be_Wrapped
2855 Store_After_Actions_In_Scope (Ins_Actions);
2857 Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
2859 end Insert_Actions_After;
2861 ---------------------------------
2862 -- Insert_Library_Level_Action --
2863 ---------------------------------
2865 procedure Insert_Library_Level_Action (N : Node_Id) is
2866 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2869 Push_Scope (Cunit_Entity (Main_Unit));
2870 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2872 if No (Actions (Aux)) then
2873 Set_Actions (Aux, New_List (N));
2875 Append (N, Actions (Aux));
2880 end Insert_Library_Level_Action;
2882 ----------------------------------
2883 -- Insert_Library_Level_Actions --
2884 ----------------------------------
2886 procedure Insert_Library_Level_Actions (L : List_Id) is
2887 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2890 if Is_Non_Empty_List (L) then
2891 Push_Scope (Cunit_Entity (Main_Unit));
2892 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2894 if No (Actions (Aux)) then
2895 Set_Actions (Aux, L);
2898 Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
2903 end Insert_Library_Level_Actions;
2905 ----------------------
2906 -- Inside_Init_Proc --
2907 ----------------------
2909 function Inside_Init_Proc return Boolean is
2915 and then S /= Standard_Standard
2917 if Is_Init_Proc (S) then
2925 end Inside_Init_Proc;
2927 ----------------------------
2928 -- Is_All_Null_Statements --
2929 ----------------------------
2931 function Is_All_Null_Statements (L : List_Id) return Boolean is
2936 while Present (Stm) loop
2937 if Nkind (Stm) /= N_Null_Statement then
2945 end Is_All_Null_Statements;
2947 ----------------------------------
2948 -- Is_Library_Level_Tagged_Type --
2949 ----------------------------------
2951 function Is_Library_Level_Tagged_Type (Typ : Entity_Id) return Boolean is
2953 return Is_Tagged_Type (Typ)
2954 and then Is_Library_Level_Entity (Typ);
2955 end Is_Library_Level_Tagged_Type;
2957 -----------------------------------------
2958 -- Is_Predefined_Dispatching_Operation --
2959 -----------------------------------------
2961 function Is_Predefined_Dispatching_Operation (E : Entity_Id) return Boolean
2963 TSS_Name : TSS_Name_Type;
2966 if not Is_Dispatching_Operation (E) then
2970 Get_Name_String (Chars (E));
2972 if Name_Len > TSS_Name_Type'Last then
2973 TSS_Name := TSS_Name_Type (Name_Buffer (Name_Len - TSS_Name'Length + 1
2975 if Chars (E) = Name_uSize
2976 or else Chars (E) = Name_uAlignment
2977 or else TSS_Name = TSS_Stream_Read
2978 or else TSS_Name = TSS_Stream_Write
2979 or else TSS_Name = TSS_Stream_Input
2980 or else TSS_Name = TSS_Stream_Output
2982 (Chars (E) = Name_Op_Eq
2983 and then Etype (First_Entity (E)) = Etype (Last_Entity (E)))
2984 or else Chars (E) = Name_uAssign
2985 or else TSS_Name = TSS_Deep_Adjust
2986 or else TSS_Name = TSS_Deep_Finalize
2987 or else (Ada_Version >= Ada_05
2988 and then (Chars (E) = Name_uDisp_Asynchronous_Select
2989 or else Chars (E) = Name_uDisp_Conditional_Select
2990 or else Chars (E) = Name_uDisp_Get_Prim_Op_Kind
2991 or else Chars (E) = Name_uDisp_Get_Task_Id
2992 or else Chars (E) = Name_uDisp_Timed_Select))
2999 end Is_Predefined_Dispatching_Operation;
3001 ----------------------------------
3002 -- Is_Possibly_Unaligned_Object --
3003 ----------------------------------
3005 function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is
3006 T : constant Entity_Id := Etype (N);
3009 -- If renamed object, apply test to underlying object
3011 if Is_Entity_Name (N)
3012 and then Is_Object (Entity (N))
3013 and then Present (Renamed_Object (Entity (N)))
3015 return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N)));
3018 -- Tagged and controlled types and aliased types are always aligned,
3019 -- as are concurrent types.
3022 or else Has_Controlled_Component (T)
3023 or else Is_Concurrent_Type (T)
3024 or else Is_Tagged_Type (T)
3025 or else Is_Controlled (T)
3030 -- If this is an element of a packed array, may be unaligned
3032 if Is_Ref_To_Bit_Packed_Array (N) then
3036 -- Case of component reference
3038 if Nkind (N) = N_Selected_Component then
3040 P : constant Node_Id := Prefix (N);
3041 C : constant Entity_Id := Entity (Selector_Name (N));
3046 -- If component reference is for an array with non-static bounds,
3047 -- then it is always aligned: we can only process unaligned
3048 -- arrays with static bounds (more accurately bounds known at
3051 if Is_Array_Type (T)
3052 and then not Compile_Time_Known_Bounds (T)
3057 -- If component is aliased, it is definitely properly aligned
3059 if Is_Aliased (C) then
3063 -- If component is for a type implemented as a scalar, and the
3064 -- record is packed, and the component is other than the first
3065 -- component of the record, then the component may be unaligned.
3067 if Is_Packed (Etype (P))
3068 and then Represented_As_Scalar (Etype (C))
3069 and then First_Entity (Scope (C)) /= C
3074 -- Compute maximum possible alignment for T
3076 -- If alignment is known, then that settles things
3078 if Known_Alignment (T) then
3079 M := UI_To_Int (Alignment (T));
3081 -- If alignment is not known, tentatively set max alignment
3084 M := Ttypes.Maximum_Alignment;
3086 -- We can reduce this if the Esize is known since the default
3087 -- alignment will never be more than the smallest power of 2
3088 -- that does not exceed this Esize value.
3090 if Known_Esize (T) then
3091 S := UI_To_Int (Esize (T));
3093 while (M / 2) >= S loop
3099 -- If the component reference is for a record that has a specified
3100 -- alignment, and we either know it is too small, or cannot tell,
3101 -- then the component may be unaligned
3103 if Known_Alignment (Etype (P))
3104 and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment
3105 and then M > Alignment (Etype (P))
3110 -- Case of component clause present which may specify an
3111 -- unaligned position.
3113 if Present (Component_Clause (C)) then
3115 -- Otherwise we can do a test to make sure that the actual
3116 -- start position in the record, and the length, are both
3117 -- consistent with the required alignment. If not, we know
3118 -- that we are unaligned.
3121 Align_In_Bits : constant Nat := M * System_Storage_Unit;
3123 if Component_Bit_Offset (C) mod Align_In_Bits /= 0
3124 or else Esize (C) mod Align_In_Bits /= 0
3131 -- Otherwise, for a component reference, test prefix
3133 return Is_Possibly_Unaligned_Object (P);
3136 -- If not a component reference, must be aligned
3141 end Is_Possibly_Unaligned_Object;
3143 ---------------------------------
3144 -- Is_Possibly_Unaligned_Slice --
3145 ---------------------------------
3147 function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is
3149 -- Go to renamed object
3151 if Is_Entity_Name (N)
3152 and then Is_Object (Entity (N))
3153 and then Present (Renamed_Object (Entity (N)))
3155 return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N)));
3158 -- The reference must be a slice
3160 if Nkind (N) /= N_Slice then
3164 -- Always assume the worst for a nested record component with a
3165 -- component clause, which gigi/gcc does not appear to handle well.
3166 -- It is not clear why this special test is needed at all ???
3168 if Nkind (Prefix (N)) = N_Selected_Component
3169 and then Nkind (Prefix (Prefix (N))) = N_Selected_Component
3171 Present (Component_Clause (Entity (Selector_Name (Prefix (N)))))
3176 -- We only need to worry if the target has strict alignment
3178 if not Target_Strict_Alignment then
3182 -- If it is a slice, then look at the array type being sliced
3185 Sarr : constant Node_Id := Prefix (N);
3186 -- Prefix of the slice, i.e. the array being sliced
3188 Styp : constant Entity_Id := Etype (Prefix (N));
3189 -- Type of the array being sliced
3195 -- The problems arise if the array object that is being sliced
3196 -- is a component of a record or array, and we cannot guarantee
3197 -- the alignment of the array within its containing object.
3199 -- To investigate this, we look at successive prefixes to see
3200 -- if we have a worrisome indexed or selected component.
3204 -- Case of array is part of an indexed component reference
3206 if Nkind (Pref) = N_Indexed_Component then
3207 Ptyp := Etype (Prefix (Pref));
3209 -- The only problematic case is when the array is packed,
3210 -- in which case we really know nothing about the alignment
3211 -- of individual components.
3213 if Is_Bit_Packed_Array (Ptyp) then
3217 -- Case of array is part of a selected component reference
3219 elsif Nkind (Pref) = N_Selected_Component then
3220 Ptyp := Etype (Prefix (Pref));
3222 -- We are definitely in trouble if the record in question
3223 -- has an alignment, and either we know this alignment is
3224 -- inconsistent with the alignment of the slice, or we
3225 -- don't know what the alignment of the slice should be.
3227 if Known_Alignment (Ptyp)
3228 and then (Unknown_Alignment (Styp)
3229 or else Alignment (Styp) > Alignment (Ptyp))
3234 -- We are in potential trouble if the record type is packed.
3235 -- We could special case when we know that the array is the
3236 -- first component, but that's not such a simple case ???
3238 if Is_Packed (Ptyp) then
3242 -- We are in trouble if there is a component clause, and
3243 -- either we do not know the alignment of the slice, or
3244 -- the alignment of the slice is inconsistent with the
3245 -- bit position specified by the component clause.
3248 Field : constant Entity_Id := Entity (Selector_Name (Pref));
3250 if Present (Component_Clause (Field))
3252 (Unknown_Alignment (Styp)
3254 (Component_Bit_Offset (Field) mod
3255 (System_Storage_Unit * Alignment (Styp))) /= 0)
3261 -- For cases other than selected or indexed components we
3262 -- know we are OK, since no issues arise over alignment.
3268 -- We processed an indexed component or selected component
3269 -- reference that looked safe, so keep checking prefixes.
3271 Pref := Prefix (Pref);
3274 end Is_Possibly_Unaligned_Slice;
3276 --------------------------------
3277 -- Is_Ref_To_Bit_Packed_Array --
3278 --------------------------------
3280 function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is
3285 if Is_Entity_Name (N)
3286 and then Is_Object (Entity (N))
3287 and then Present (Renamed_Object (Entity (N)))
3289 return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N)));
3292 if Nkind (N) = N_Indexed_Component
3294 Nkind (N) = N_Selected_Component
3296 if Is_Bit_Packed_Array (Etype (Prefix (N))) then
3299 Result := Is_Ref_To_Bit_Packed_Array (Prefix (N));
3302 if Result and then Nkind (N) = N_Indexed_Component then
3303 Expr := First (Expressions (N));
3304 while Present (Expr) loop
3305 Force_Evaluation (Expr);
3315 end Is_Ref_To_Bit_Packed_Array;
3317 --------------------------------
3318 -- Is_Ref_To_Bit_Packed_Slice --
3319 --------------------------------
3321 function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is
3323 if Nkind (N) = N_Type_Conversion then
3324 return Is_Ref_To_Bit_Packed_Slice (Expression (N));
3326 elsif Is_Entity_Name (N)
3327 and then Is_Object (Entity (N))
3328 and then Present (Renamed_Object (Entity (N)))
3330 return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N)));
3332 elsif Nkind (N) = N_Slice
3333 and then Is_Bit_Packed_Array (Etype (Prefix (N)))
3337 elsif Nkind (N) = N_Indexed_Component
3339 Nkind (N) = N_Selected_Component
3341 return Is_Ref_To_Bit_Packed_Slice (Prefix (N));
3346 end Is_Ref_To_Bit_Packed_Slice;
3348 -----------------------
3349 -- Is_Renamed_Object --
3350 -----------------------
3352 function Is_Renamed_Object (N : Node_Id) return Boolean is
3353 Pnod : constant Node_Id := Parent (N);
3354 Kind : constant Node_Kind := Nkind (Pnod);
3357 if Kind = N_Object_Renaming_Declaration then
3360 elsif Kind = N_Indexed_Component
3361 or else Kind = N_Selected_Component
3363 return Is_Renamed_Object (Pnod);
3368 end Is_Renamed_Object;
3370 ----------------------------
3371 -- Is_Untagged_Derivation --
3372 ----------------------------
3374 function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
3376 return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
3378 (Is_Private_Type (T) and then Present (Full_View (T))
3379 and then not Is_Tagged_Type (Full_View (T))
3380 and then Is_Derived_Type (Full_View (T))
3381 and then Etype (Full_View (T)) /= T);
3382 end Is_Untagged_Derivation;
3384 --------------------
3385 -- Kill_Dead_Code --
3386 --------------------
3388 procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is
3391 Remove_Warning_Messages (N);
3395 ("?this code can never be executed and has been deleted!", N);
3398 -- Recurse into block statements and bodies to process declarations
3401 if Nkind (N) = N_Block_Statement
3402 or else Nkind (N) = N_Subprogram_Body
3403 or else Nkind (N) = N_Package_Body
3405 Kill_Dead_Code (Declarations (N), False);
3406 Kill_Dead_Code (Statements (Handled_Statement_Sequence (N)));
3408 if Nkind (N) = N_Subprogram_Body then
3409 Set_Is_Eliminated (Defining_Entity (N));
3412 elsif Nkind (N) = N_Package_Declaration then
3413 Kill_Dead_Code (Visible_Declarations (Specification (N)));
3414 Kill_Dead_Code (Private_Declarations (Specification (N)));
3416 -- ??? After this point, Delete_Tree has been called on all
3417 -- declarations in Specification (N), so references to
3418 -- entities therein look suspicious.
3421 E : Entity_Id := First_Entity (Defining_Entity (N));
3423 while Present (E) loop
3424 if Ekind (E) = E_Operator then
3425 Set_Is_Eliminated (E);
3432 -- Recurse into composite statement to kill individual statements,
3433 -- in particular instantiations.
3435 elsif Nkind (N) = N_If_Statement then
3436 Kill_Dead_Code (Then_Statements (N));
3437 Kill_Dead_Code (Elsif_Parts (N));
3438 Kill_Dead_Code (Else_Statements (N));
3440 elsif Nkind (N) = N_Loop_Statement then
3441 Kill_Dead_Code (Statements (N));
3443 elsif Nkind (N) = N_Case_Statement then
3447 Alt := First (Alternatives (N));
3448 while Present (Alt) loop
3449 Kill_Dead_Code (Statements (Alt));
3454 elsif Nkind (N) = N_Case_Statement_Alternative then
3455 Kill_Dead_Code (Statements (N));
3457 -- Deal with dead instances caused by deleting instantiations
3459 elsif Nkind (N) in N_Generic_Instantiation then
3460 Remove_Dead_Instance (N);
3467 -- Case where argument is a list of nodes to be killed
3469 procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is
3474 if Is_Non_Empty_List (L) then
3476 N := Remove_Head (L);
3478 Kill_Dead_Code (N, W);
3484 ------------------------
3485 -- Known_Non_Negative --
3486 ------------------------
3488 function Known_Non_Negative (Opnd : Node_Id) return Boolean is
3490 if Is_OK_Static_Expression (Opnd)
3491 and then Expr_Value (Opnd) >= 0
3497 Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd));
3501 Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0;
3504 end Known_Non_Negative;
3506 --------------------
3507 -- Known_Non_Null --
3508 --------------------
3510 function Known_Non_Null (N : Node_Id) return Boolean is
3512 -- Checks for case where N is an entity reference
3514 if Is_Entity_Name (N) and then Present (Entity (N)) then
3516 E : constant Entity_Id := Entity (N);
3521 -- First check if we are in decisive conditional
3523 Get_Current_Value_Condition (N, Op, Val);
3525 if Known_Null (Val) then
3526 if Op = N_Op_Eq then
3528 elsif Op = N_Op_Ne then
3533 -- If OK to do replacement, test Is_Known_Non_Null flag
3535 if OK_To_Do_Constant_Replacement (E) then
3536 return Is_Known_Non_Null (E);
3538 -- Otherwise if not safe to do replacement, then say so
3545 -- True if access attribute
3547 elsif Nkind (N) = N_Attribute_Reference
3548 and then (Attribute_Name (N) = Name_Access
3550 Attribute_Name (N) = Name_Unchecked_Access
3552 Attribute_Name (N) = Name_Unrestricted_Access)
3556 -- True if allocator
3558 elsif Nkind (N) = N_Allocator then
3561 -- For a conversion, true if expression is known non-null
3563 elsif Nkind (N) = N_Type_Conversion then
3564 return Known_Non_Null (Expression (N));
3566 -- Above are all cases where the value could be determined to be
3567 -- non-null. In all other cases, we don't know, so return False.
3578 function Known_Null (N : Node_Id) return Boolean is
3580 -- Checks for case where N is an entity reference
3582 if Is_Entity_Name (N) and then Present (Entity (N)) then
3584 E : constant Entity_Id := Entity (N);
3589 -- Constant null value is for sure null
3591 if Ekind (E) = E_Constant
3592 and then Known_Null (Constant_Value (E))
3597 -- First check if we are in decisive conditional
3599 Get_Current_Value_Condition (N, Op, Val);
3601 if Known_Null (Val) then
3602 if Op = N_Op_Eq then
3604 elsif Op = N_Op_Ne then
3609 -- If OK to do replacement, test Is_Known_Null flag
3611 if OK_To_Do_Constant_Replacement (E) then
3612 return Is_Known_Null (E);
3614 -- Otherwise if not safe to do replacement, then say so
3621 -- True if explicit reference to null
3623 elsif Nkind (N) = N_Null then
3626 -- For a conversion, true if expression is known null
3628 elsif Nkind (N) = N_Type_Conversion then
3629 return Known_Null (Expression (N));
3631 -- Above are all cases where the value could be determined to be null.
3632 -- In all other cases, we don't know, so return False.
3639 -----------------------------
3640 -- Make_CW_Equivalent_Type --
3641 -----------------------------
3643 -- Create a record type used as an equivalent of any member
3644 -- of the class which takes its size from exp.
3646 -- Generate the following code:
3648 -- type Equiv_T is record
3649 -- _parent : T (List of discriminant constaints taken from Exp);
3650 -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
3653 -- ??? Note that this type does not guarantee same alignment as all
3656 function Make_CW_Equivalent_Type
3658 E : Node_Id) return Entity_Id
3660 Loc : constant Source_Ptr := Sloc (E);
3661 Root_Typ : constant Entity_Id := Root_Type (T);
3662 List_Def : constant List_Id := Empty_List;
3663 Comp_List : constant List_Id := New_List;
3664 Equiv_Type : Entity_Id;
3665 Range_Type : Entity_Id;
3666 Str_Type : Entity_Id;
3667 Constr_Root : Entity_Id;
3671 if not Has_Discriminants (Root_Typ) then
3672 Constr_Root := Root_Typ;
3675 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
3677 -- subtype cstr__n is T (List of discr constraints taken from Exp)
3679 Append_To (List_Def,
3680 Make_Subtype_Declaration (Loc,
3681 Defining_Identifier => Constr_Root,
3682 Subtype_Indication =>
3683 Make_Subtype_From_Expr (E, Root_Typ)));
3686 -- Generate the range subtype declaration
3688 Range_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('G'));
3690 if not Is_Interface (Root_Typ) then
3691 -- subtype rg__xx is
3692 -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit
3695 Make_Op_Subtract (Loc,
3697 Make_Attribute_Reference (Loc,
3699 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3700 Attribute_Name => Name_Size),
3702 Make_Attribute_Reference (Loc,
3703 Prefix => New_Reference_To (Constr_Root, Loc),
3704 Attribute_Name => Name_Object_Size));
3706 -- subtype rg__xx is
3707 -- Storage_Offset range 1 .. Expr'size / Storage_Unit
3710 Make_Attribute_Reference (Loc,
3712 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3713 Attribute_Name => Name_Size);
3716 Set_Paren_Count (Sizexpr, 1);
3718 Append_To (List_Def,
3719 Make_Subtype_Declaration (Loc,
3720 Defining_Identifier => Range_Type,
3721 Subtype_Indication =>
3722 Make_Subtype_Indication (Loc,
3723 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc),
3724 Constraint => Make_Range_Constraint (Loc,
3727 Low_Bound => Make_Integer_Literal (Loc, 1),
3729 Make_Op_Divide (Loc,
3730 Left_Opnd => Sizexpr,
3731 Right_Opnd => Make_Integer_Literal (Loc,
3732 Intval => System_Storage_Unit)))))));
3734 -- subtype str__nn is Storage_Array (rg__x);
3736 Str_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
3737 Append_To (List_Def,
3738 Make_Subtype_Declaration (Loc,
3739 Defining_Identifier => Str_Type,
3740 Subtype_Indication =>
3741 Make_Subtype_Indication (Loc,
3742 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc),
3744 Make_Index_Or_Discriminant_Constraint (Loc,
3746 New_List (New_Reference_To (Range_Type, Loc))))));
3748 -- type Equiv_T is record
3749 -- [ _parent : Tnn; ]
3753 Equiv_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
3755 -- When the target requires front-end layout, it's necessary to allow
3756 -- the equivalent type to be frozen so that layout can occur (when the
3757 -- associated class-wide subtype is frozen, the equivalent type will
3758 -- be frozen, see freeze.adb). For other targets, Gigi wants to have
3759 -- the equivalent type marked as frozen and deals with this type itself.
3760 -- In the Gigi case this will also avoid the generation of an init
3761 -- procedure for the type.
3763 if not Frontend_Layout_On_Target then
3764 Set_Is_Frozen (Equiv_Type);
3767 Set_Ekind (Equiv_Type, E_Record_Type);
3768 Set_Parent_Subtype (Equiv_Type, Constr_Root);
3770 if not Is_Interface (Root_Typ) then
3771 Append_To (Comp_List,
3772 Make_Component_Declaration (Loc,
3773 Defining_Identifier =>
3774 Make_Defining_Identifier (Loc, Name_uParent),
3775 Component_Definition =>
3776 Make_Component_Definition (Loc,
3777 Aliased_Present => False,
3778 Subtype_Indication => New_Reference_To (Constr_Root, Loc))));
3781 Append_To (Comp_List,
3782 Make_Component_Declaration (Loc,
3783 Defining_Identifier =>
3784 Make_Defining_Identifier (Loc,
3785 Chars => New_Internal_Name ('C')),
3786 Component_Definition =>
3787 Make_Component_Definition (Loc,
3788 Aliased_Present => False,
3789 Subtype_Indication => New_Reference_To (Str_Type, Loc))));
3791 Append_To (List_Def,
3792 Make_Full_Type_Declaration (Loc,
3793 Defining_Identifier => Equiv_Type,
3795 Make_Record_Definition (Loc,
3797 Make_Component_List (Loc,
3798 Component_Items => Comp_List,
3799 Variant_Part => Empty))));
3801 -- Suppress all checks during the analysis of the expanded code
3802 -- to avoid the generation of spurious warnings under ZFP run-time.
3804 Insert_Actions (E, List_Def, Suppress => All_Checks);
3806 end Make_CW_Equivalent_Type;
3808 ------------------------
3809 -- Make_Literal_Range --
3810 ------------------------
3812 function Make_Literal_Range
3814 Literal_Typ : Entity_Id) return Node_Id
3816 Lo : constant Node_Id :=
3817 New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
3818 Index : constant Entity_Id := Etype (Lo);
3821 Length_Expr : constant Node_Id :=
3822 Make_Op_Subtract (Loc,
3824 Make_Integer_Literal (Loc,
3825 Intval => String_Literal_Length (Literal_Typ)),
3827 Make_Integer_Literal (Loc, 1));
3830 Set_Analyzed (Lo, False);
3832 if Is_Integer_Type (Index) then
3835 Left_Opnd => New_Copy_Tree (Lo),
3836 Right_Opnd => Length_Expr);
3839 Make_Attribute_Reference (Loc,
3840 Attribute_Name => Name_Val,
3841 Prefix => New_Occurrence_Of (Index, Loc),
3842 Expressions => New_List (
3845 Make_Attribute_Reference (Loc,
3846 Attribute_Name => Name_Pos,
3847 Prefix => New_Occurrence_Of (Index, Loc),
3848 Expressions => New_List (New_Copy_Tree (Lo))),
3849 Right_Opnd => Length_Expr)));
3856 end Make_Literal_Range;
3858 ----------------------------
3859 -- Make_Subtype_From_Expr --
3860 ----------------------------
3862 -- 1. If Expr is an uncontrained array expression, creates
3863 -- Unc_Type(Expr'first(1)..Expr'Last(1),..., Expr'first(n)..Expr'last(n))
3865 -- 2. If Expr is a unconstrained discriminated type expression, creates
3866 -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
3868 -- 3. If Expr is class-wide, creates an implicit class wide subtype
3870 function Make_Subtype_From_Expr
3872 Unc_Typ : Entity_Id) return Node_Id
3874 Loc : constant Source_Ptr := Sloc (E);
3875 List_Constr : constant List_Id := New_List;
3878 Full_Subtyp : Entity_Id;
3879 Priv_Subtyp : Entity_Id;
3884 if Is_Private_Type (Unc_Typ)
3885 and then Has_Unknown_Discriminants (Unc_Typ)
3887 -- Prepare the subtype completion, Go to base type to
3888 -- find underlying type, because the type may be a generic
3889 -- actual or an explicit subtype.
3891 Utyp := Underlying_Type (Base_Type (Unc_Typ));
3892 Full_Subtyp := Make_Defining_Identifier (Loc,
3893 New_Internal_Name ('C'));
3895 Unchecked_Convert_To
3896 (Utyp, Duplicate_Subexpr_No_Checks (E));
3897 Set_Parent (Full_Exp, Parent (E));
3900 Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
3903 Make_Subtype_Declaration (Loc,
3904 Defining_Identifier => Full_Subtyp,
3905 Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
3907 -- Define the dummy private subtype
3909 Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
3910 Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ));
3911 Set_Scope (Priv_Subtyp, Full_Subtyp);
3912 Set_Is_Constrained (Priv_Subtyp);
3913 Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
3914 Set_Is_Itype (Priv_Subtyp);
3915 Set_Associated_Node_For_Itype (Priv_Subtyp, E);
3917 if Is_Tagged_Type (Priv_Subtyp) then
3919 (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
3920 Set_Primitive_Operations (Priv_Subtyp,
3921 Primitive_Operations (Unc_Typ));
3924 Set_Full_View (Priv_Subtyp, Full_Subtyp);
3926 return New_Reference_To (Priv_Subtyp, Loc);
3928 elsif Is_Array_Type (Unc_Typ) then
3929 for J in 1 .. Number_Dimensions (Unc_Typ) loop
3930 Append_To (List_Constr,
3933 Make_Attribute_Reference (Loc,
3934 Prefix => Duplicate_Subexpr_No_Checks (E),
3935 Attribute_Name => Name_First,
3936 Expressions => New_List (
3937 Make_Integer_Literal (Loc, J))),
3940 Make_Attribute_Reference (Loc,
3941 Prefix => Duplicate_Subexpr_No_Checks (E),
3942 Attribute_Name => Name_Last,
3943 Expressions => New_List (
3944 Make_Integer_Literal (Loc, J)))));
3947 elsif Is_Class_Wide_Type (Unc_Typ) then
3949 CW_Subtype : Entity_Id;
3950 EQ_Typ : Entity_Id := Empty;
3953 -- A class-wide equivalent type is not needed when VM_Target
3954 -- because the VM back-ends handle the class-wide object
3955 -- initialization itself (and doesn't need or want the
3956 -- additional intermediate type to handle the assignment).
3958 if Expander_Active and then VM_Target = No_VM then
3959 EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
3962 CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
3963 Set_Equivalent_Type (CW_Subtype, EQ_Typ);
3965 if Present (EQ_Typ) then
3966 Set_Is_Class_Wide_Equivalent_Type (EQ_Typ);
3969 Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
3971 return New_Occurrence_Of (CW_Subtype, Loc);
3974 -- Indefinite record type with discriminants
3977 D := First_Discriminant (Unc_Typ);
3978 while Present (D) loop
3979 Append_To (List_Constr,
3980 Make_Selected_Component (Loc,
3981 Prefix => Duplicate_Subexpr_No_Checks (E),
3982 Selector_Name => New_Reference_To (D, Loc)));
3984 Next_Discriminant (D);
3989 Make_Subtype_Indication (Loc,
3990 Subtype_Mark => New_Reference_To (Unc_Typ, Loc),
3992 Make_Index_Or_Discriminant_Constraint (Loc,
3993 Constraints => List_Constr));
3994 end Make_Subtype_From_Expr;
3996 -----------------------------
3997 -- May_Generate_Large_Temp --
3998 -----------------------------
4000 -- At the current time, the only types that we return False for (i.e.
4001 -- where we decide we know they cannot generate large temps) are ones
4002 -- where we know the size is 256 bits or less at compile time, and we
4003 -- are still not doing a thorough job on arrays and records ???
4005 function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
4007 if not Size_Known_At_Compile_Time (Typ) then
4010 elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then
4013 elsif Is_Array_Type (Typ)
4014 and then Present (Packed_Array_Type (Typ))
4016 return May_Generate_Large_Temp (Packed_Array_Type (Typ));
4018 -- We could do more here to find other small types ???
4023 end May_Generate_Large_Temp;
4025 ----------------------------
4026 -- New_Class_Wide_Subtype --
4027 ----------------------------
4029 function New_Class_Wide_Subtype
4030 (CW_Typ : Entity_Id;
4031 N : Node_Id) return Entity_Id
4033 Res : constant Entity_Id := Create_Itype (E_Void, N);
4034 Res_Name : constant Name_Id := Chars (Res);
4035 Res_Scope : constant Entity_Id := Scope (Res);
4038 Copy_Node (CW_Typ, Res);
4039 Set_Comes_From_Source (Res, False);
4040 Set_Sloc (Res, Sloc (N));
4042 Set_Associated_Node_For_Itype (Res, N);
4043 Set_Is_Public (Res, False); -- By default, may be changed below.
4044 Set_Public_Status (Res);
4045 Set_Chars (Res, Res_Name);
4046 Set_Scope (Res, Res_Scope);
4047 Set_Ekind (Res, E_Class_Wide_Subtype);
4048 Set_Next_Entity (Res, Empty);
4049 Set_Etype (Res, Base_Type (CW_Typ));
4051 -- For targets where front-end layout is required, reset the Is_Frozen
4052 -- status of the subtype to False (it can be implicitly set to true
4053 -- from the copy of the class-wide type). For other targets, Gigi
4054 -- doesn't want the class-wide subtype to go through the freezing
4055 -- process (though it's unclear why that causes problems and it would
4056 -- be nice to allow freezing to occur normally for all targets ???).
4058 if Frontend_Layout_On_Target then
4059 Set_Is_Frozen (Res, False);
4062 Set_Freeze_Node (Res, Empty);
4064 end New_Class_Wide_Subtype;
4066 --------------------------------
4067 -- Non_Limited_Designated_Type --
4068 ---------------------------------
4070 function Non_Limited_Designated_Type (T : Entity_Id) return Entity_Id is
4071 Desig : constant Entity_Id := Designated_Type (T);
4073 if Ekind (Desig) = E_Incomplete_Type
4074 and then Present (Non_Limited_View (Desig))
4076 return Non_Limited_View (Desig);
4080 end Non_Limited_Designated_Type;
4082 -----------------------------------
4083 -- OK_To_Do_Constant_Replacement --
4084 -----------------------------------
4086 function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is
4087 ES : constant Entity_Id := Scope (E);
4091 -- Do not replace statically allocated objects, because they may be
4092 -- modified outside the current scope.
4094 if Is_Statically_Allocated (E) then
4097 -- Do not replace aliased or volatile objects, since we don't know what
4098 -- else might change the value.
4100 elsif Is_Aliased (E) or else Treat_As_Volatile (E) then
4103 -- Debug flag -gnatdM disconnects this optimization
4105 elsif Debug_Flag_MM then
4108 -- Otherwise check scopes
4111 CS := Current_Scope;
4114 -- If we are in right scope, replacement is safe
4119 -- Packages do not affect the determination of safety
4121 elsif Ekind (CS) = E_Package then
4122 exit when CS = Standard_Standard;
4125 -- Blocks do not affect the determination of safety
4127 elsif Ekind (CS) = E_Block then
4130 -- Loops do not affect the determination of safety. Note that we
4131 -- kill all current values on entry to a loop, so we are just
4132 -- talking about processing within a loop here.
4134 elsif Ekind (CS) = E_Loop then
4137 -- Otherwise, the reference is dubious, and we cannot be sure that
4138 -- it is safe to do the replacement.
4147 end OK_To_Do_Constant_Replacement;
4149 ------------------------------------
4150 -- Possible_Bit_Aligned_Component --
4151 ------------------------------------
4153 function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is
4157 -- Case of indexed component
4159 when N_Indexed_Component =>
4161 P : constant Node_Id := Prefix (N);
4162 Ptyp : constant Entity_Id := Etype (P);
4165 -- If we know the component size and it is less than 64, then
4166 -- we are definitely OK. The back end always does assignment
4167 -- of misaligned small objects correctly.
4169 if Known_Static_Component_Size (Ptyp)
4170 and then Component_Size (Ptyp) <= 64
4174 -- Otherwise, we need to test the prefix, to see if we are
4175 -- indexing from a possibly unaligned component.
4178 return Possible_Bit_Aligned_Component (P);
4182 -- Case of selected component
4184 when N_Selected_Component =>
4186 P : constant Node_Id := Prefix (N);
4187 Comp : constant Entity_Id := Entity (Selector_Name (N));
4190 -- If there is no component clause, then we are in the clear
4191 -- since the back end will never misalign a large component
4192 -- unless it is forced to do so. In the clear means we need
4193 -- only the recursive test on the prefix.
4195 if Component_May_Be_Bit_Aligned (Comp) then
4198 return Possible_Bit_Aligned_Component (P);
4202 -- If we have neither a record nor array component, it means that we
4203 -- have fallen off the top testing prefixes recursively, and we now
4204 -- have a stand alone object, where we don't have a problem.
4210 end Possible_Bit_Aligned_Component;
4212 -------------------------
4213 -- Remove_Side_Effects --
4214 -------------------------
4216 procedure Remove_Side_Effects
4218 Name_Req : Boolean := False;
4219 Variable_Ref : Boolean := False)
4221 Loc : constant Source_Ptr := Sloc (Exp);
4222 Exp_Type : constant Entity_Id := Etype (Exp);
4223 Svg_Suppress : constant Suppress_Array := Scope_Suppress;
4225 Ref_Type : Entity_Id;
4227 Ptr_Typ_Decl : Node_Id;
4231 function Side_Effect_Free (N : Node_Id) return Boolean;
4232 -- Determines if the tree N represents an expression that is known not
4233 -- to have side effects, and for which no processing is required.
4235 function Side_Effect_Free (L : List_Id) return Boolean;
4236 -- Determines if all elements of the list L are side effect free
4238 function Safe_Prefixed_Reference (N : Node_Id) return Boolean;
4239 -- The argument N is a construct where the Prefix is dereferenced if it
4240 -- is an access type and the result is a variable. The call returns True
4241 -- if the construct is side effect free (not considering side effects in
4242 -- other than the prefix which are to be tested by the caller).
4244 function Within_In_Parameter (N : Node_Id) return Boolean;
4245 -- Determines if N is a subcomponent of a composite in-parameter. If so,
4246 -- N is not side-effect free when the actual is global and modifiable
4247 -- indirectly from within a subprogram, because it may be passed by
4248 -- reference. The front-end must be conservative here and assume that
4249 -- this may happen with any array or record type. On the other hand, we
4250 -- cannot create temporaries for all expressions for which this
4251 -- condition is true, for various reasons that might require clearing up
4252 -- ??? For example, descriminant references that appear out of place, or
4253 -- spurious type errors with class-wide expressions. As a result, we
4254 -- limit the transformation to loop bounds, which is so far the only
4255 -- case that requires it.
4257 -----------------------------
4258 -- Safe_Prefixed_Reference --
4259 -----------------------------
4261 function Safe_Prefixed_Reference (N : Node_Id) return Boolean is
4263 -- If prefix is not side effect free, definitely not safe
4265 if not Side_Effect_Free (Prefix (N)) then
4268 -- If the prefix is of an access type that is not access-to-constant,
4269 -- then this construct is a variable reference, which means it is to
4270 -- be considered to have side effects if Variable_Ref is set True
4271 -- Exception is an access to an entity that is a constant or an
4272 -- in-parameter which does not come from source, and is the result
4273 -- of a previous removal of side-effects.
4275 elsif Is_Access_Type (Etype (Prefix (N)))
4276 and then not Is_Access_Constant (Etype (Prefix (N)))
4277 and then Variable_Ref
4279 if not Is_Entity_Name (Prefix (N)) then
4282 return Ekind (Entity (Prefix (N))) = E_Constant
4283 or else Ekind (Entity (Prefix (N))) = E_In_Parameter;
4286 -- The following test is the simplest way of solving a complex
4287 -- problem uncovered by BB08-010: Side effect on loop bound that
4288 -- is a subcomponent of a global variable:
4289 -- If a loop bound is a subcomponent of a global variable, a
4290 -- modification of that variable within the loop may incorrectly
4291 -- affect the execution of the loop.
4294 (Nkind (Parent (Parent (N))) /= N_Loop_Parameter_Specification
4295 or else not Within_In_Parameter (Prefix (N)))
4299 -- All other cases are side effect free
4304 end Safe_Prefixed_Reference;
4306 ----------------------
4307 -- Side_Effect_Free --
4308 ----------------------
4310 function Side_Effect_Free (N : Node_Id) return Boolean is
4312 -- Note on checks that could raise Constraint_Error. Strictly, if
4313 -- we take advantage of 11.6, these checks do not count as side
4314 -- effects. However, we would just as soon consider that they are
4315 -- side effects, since the backend CSE does not work very well on
4316 -- expressions which can raise Constraint_Error. On the other
4317 -- hand, if we do not consider them to be side effect free, then
4318 -- we get some awkward expansions in -gnato mode, resulting in
4319 -- code insertions at a point where we do not have a clear model
4320 -- for performing the insertions. See 4908-002/comment for details.
4322 -- Special handling for entity names
4324 if Is_Entity_Name (N) then
4326 -- If the entity is a constant, it is definitely side effect
4327 -- free. Note that the test of Is_Variable (N) below might
4328 -- be expected to catch this case, but it does not, because
4329 -- this test goes to the original tree, and we may have
4330 -- already rewritten a variable node with a constant as
4331 -- a result of an earlier Force_Evaluation call.
4333 if Ekind (Entity (N)) = E_Constant
4334 or else Ekind (Entity (N)) = E_In_Parameter
4338 -- Functions are not side effect free
4340 elsif Ekind (Entity (N)) = E_Function then
4343 -- Variables are considered to be a side effect if Variable_Ref
4344 -- is set or if we have a volatile variable and Name_Req is off.
4345 -- If Name_Req is True then we can't help returning a name which
4346 -- effectively allows multiple references in any case.
4348 elsif Is_Variable (N) then
4349 return not Variable_Ref
4350 and then (not Treat_As_Volatile (Entity (N))
4353 -- Any other entity (e.g. a subtype name) is definitely side
4360 -- A value known at compile time is always side effect free
4362 elsif Compile_Time_Known_Value (N) then
4365 -- A variable renaming is not side-effet free, because the
4366 -- renaming will function like a macro in the front-end in
4367 -- some cases, and an assignment can modify the the component
4368 -- designated by N, so we need to create a temporary for it.
4370 elsif Is_Entity_Name (Original_Node (N))
4371 and then Is_Renaming_Of_Object (Entity (Original_Node (N)))
4372 and then Ekind (Entity (Original_Node (N))) /= E_Constant
4377 -- For other than entity names and compile time known values,
4378 -- check the node kind for special processing.
4382 -- An attribute reference is side effect free if its expressions
4383 -- are side effect free and its prefix is side effect free or
4384 -- is an entity reference.
4386 -- Is this right? what about x'first where x is a variable???
4388 when N_Attribute_Reference =>
4389 return Side_Effect_Free (Expressions (N))
4390 and then Attribute_Name (N) /= Name_Input
4391 and then (Is_Entity_Name (Prefix (N))
4392 or else Side_Effect_Free (Prefix (N)));
4394 -- A binary operator is side effect free if and both operands
4395 -- are side effect free. For this purpose binary operators
4396 -- include membership tests and short circuit forms
4402 return Side_Effect_Free (Left_Opnd (N))
4403 and then Side_Effect_Free (Right_Opnd (N));
4405 -- An explicit dereference is side effect free only if it is
4406 -- a side effect free prefixed reference.
4408 when N_Explicit_Dereference =>
4409 return Safe_Prefixed_Reference (N);
4411 -- A call to _rep_to_pos is side effect free, since we generate
4412 -- this pure function call ourselves. Moreover it is critically
4413 -- important to make this exception, since otherwise we can
4414 -- have discriminants in array components which don't look
4415 -- side effect free in the case of an array whose index type
4416 -- is an enumeration type with an enumeration rep clause.
4418 -- All other function calls are not side effect free
4420 when N_Function_Call =>
4421 return Nkind (Name (N)) = N_Identifier
4422 and then Is_TSS (Name (N), TSS_Rep_To_Pos)
4424 Side_Effect_Free (First (Parameter_Associations (N)));
4426 -- An indexed component is side effect free if it is a side
4427 -- effect free prefixed reference and all the indexing
4428 -- expressions are side effect free.
4430 when N_Indexed_Component =>
4431 return Side_Effect_Free (Expressions (N))
4432 and then Safe_Prefixed_Reference (N);
4434 -- A type qualification is side effect free if the expression
4435 -- is side effect free.
4437 when N_Qualified_Expression =>
4438 return Side_Effect_Free (Expression (N));
4440 -- A selected component is side effect free only if it is a
4441 -- side effect free prefixed reference. If it designates a
4442 -- component with a rep. clause it must be treated has having
4443 -- a potential side effect, because it may be modified through
4444 -- a renaming, and a subsequent use of the renaming as a macro
4445 -- will yield the wrong value. This complex interaction between
4446 -- renaming and removing side effects is a reminder that the
4447 -- latter has become a headache to maintain, and that it should
4448 -- be removed in favor of the gcc mechanism to capture values ???
4450 when N_Selected_Component =>
4451 if Nkind (Parent (N)) = N_Explicit_Dereference
4452 and then Has_Non_Standard_Rep (Designated_Type (Etype (N)))
4456 return Safe_Prefixed_Reference (N);
4459 -- A range is side effect free if the bounds are side effect free
4462 return Side_Effect_Free (Low_Bound (N))
4463 and then Side_Effect_Free (High_Bound (N));
4465 -- A slice is side effect free if it is a side effect free
4466 -- prefixed reference and the bounds are side effect free.
4469 return Side_Effect_Free (Discrete_Range (N))
4470 and then Safe_Prefixed_Reference (N);
4472 -- A type conversion is side effect free if the expression to be
4473 -- converted is side effect free.
4475 when N_Type_Conversion =>
4476 return Side_Effect_Free (Expression (N));
4478 -- A unary operator is side effect free if the operand
4479 -- is side effect free.
4482 return Side_Effect_Free (Right_Opnd (N));
4484 -- An unchecked type conversion is side effect free only if it
4485 -- is safe and its argument is side effect free.
4487 when N_Unchecked_Type_Conversion =>
4488 return Safe_Unchecked_Type_Conversion (N)
4489 and then Side_Effect_Free (Expression (N));
4491 -- An unchecked expression is side effect free if its expression
4492 -- is side effect free.
4494 when N_Unchecked_Expression =>
4495 return Side_Effect_Free (Expression (N));
4497 -- A literal is side effect free
4499 when N_Character_Literal |
4505 -- We consider that anything else has side effects. This is a bit
4506 -- crude, but we are pretty close for most common cases, and we
4507 -- are certainly correct (i.e. we never return True when the
4508 -- answer should be False).
4513 end Side_Effect_Free;
4515 -- A list is side effect free if all elements of the list are
4516 -- side effect free.
4518 function Side_Effect_Free (L : List_Id) return Boolean is
4522 if L = No_List or else L = Error_List then
4527 while Present (N) loop
4528 if not Side_Effect_Free (N) then
4537 end Side_Effect_Free;
4539 -------------------------
4540 -- Within_In_Parameter --
4541 -------------------------
4543 function Within_In_Parameter (N : Node_Id) return Boolean is
4545 if not Comes_From_Source (N) then
4548 elsif Is_Entity_Name (N) then
4549 return Ekind (Entity (N)) = E_In_Parameter;
4551 elsif Nkind (N) = N_Indexed_Component
4552 or else Nkind (N) = N_Selected_Component
4554 return Within_In_Parameter (Prefix (N));
4559 end Within_In_Parameter;
4561 -- Start of processing for Remove_Side_Effects
4564 -- If we are side effect free already or expansion is disabled,
4565 -- there is nothing to do.
4567 if Side_Effect_Free (Exp) or else not Expander_Active then
4571 -- All this must not have any checks
4573 Scope_Suppress := (others => True);
4575 -- If it is a scalar type and we need to capture the value, just make
4576 -- a copy. Likewise for a function or operator call. And if we have a
4577 -- volatile variable and Nam_Req is not set (see comments above for
4578 -- Side_Effect_Free).
4580 if Is_Elementary_Type (Exp_Type)
4581 and then (Variable_Ref
4582 or else Nkind (Exp) = N_Function_Call
4583 or else Nkind (Exp) in N_Op
4584 or else (not Name_Req
4585 and then Is_Entity_Name (Exp)
4586 and then Treat_As_Volatile (Entity (Exp))))
4588 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4589 Set_Etype (Def_Id, Exp_Type);
4590 Res := New_Reference_To (Def_Id, Loc);
4593 Make_Object_Declaration (Loc,
4594 Defining_Identifier => Def_Id,
4595 Object_Definition => New_Reference_To (Exp_Type, Loc),
4596 Constant_Present => True,
4597 Expression => Relocate_Node (Exp));
4599 Set_Assignment_OK (E);
4600 Insert_Action (Exp, E);
4602 -- If the expression has the form v.all then we can just capture
4603 -- the pointer, and then do an explicit dereference on the result.
4605 elsif Nkind (Exp) = N_Explicit_Dereference then
4607 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4609 Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc));
4612 Make_Object_Declaration (Loc,
4613 Defining_Identifier => Def_Id,
4614 Object_Definition =>
4615 New_Reference_To (Etype (Prefix (Exp)), Loc),
4616 Constant_Present => True,
4617 Expression => Relocate_Node (Prefix (Exp))));
4619 -- Similar processing for an unchecked conversion of an expression
4620 -- of the form v.all, where we want the same kind of treatment.
4622 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4623 and then Nkind (Expression (Exp)) = N_Explicit_Dereference
4625 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4626 Scope_Suppress := Svg_Suppress;
4629 -- If this is a type conversion, leave the type conversion and remove
4630 -- the side effects in the expression. This is important in several
4631 -- circumstances: for change of representations, and also when this
4632 -- is a view conversion to a smaller object, where gigi can end up
4633 -- creating its own temporary of the wrong size.
4635 elsif Nkind (Exp) = N_Type_Conversion then
4636 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4637 Scope_Suppress := Svg_Suppress;
4640 -- If this is an unchecked conversion that Gigi can't handle, make
4641 -- a copy or a use a renaming to capture the value.
4643 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4644 and then not Safe_Unchecked_Type_Conversion (Exp)
4646 if CW_Or_Controlled_Type (Exp_Type) then
4648 -- Use a renaming to capture the expression, rather than create
4649 -- a controlled temporary.
4651 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4652 Res := New_Reference_To (Def_Id, Loc);
4655 Make_Object_Renaming_Declaration (Loc,
4656 Defining_Identifier => Def_Id,
4657 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4658 Name => Relocate_Node (Exp)));
4661 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4662 Set_Etype (Def_Id, Exp_Type);
4663 Res := New_Reference_To (Def_Id, Loc);
4666 Make_Object_Declaration (Loc,
4667 Defining_Identifier => Def_Id,
4668 Object_Definition => New_Reference_To (Exp_Type, Loc),
4669 Constant_Present => not Is_Variable (Exp),
4670 Expression => Relocate_Node (Exp));
4672 Set_Assignment_OK (E);
4673 Insert_Action (Exp, E);
4676 -- For expressions that denote objects, we can use a renaming scheme.
4677 -- We skip using this if we have a volatile variable and we do not
4678 -- have Nam_Req set true (see comments above for Side_Effect_Free).
4680 elsif Is_Object_Reference (Exp)
4681 and then Nkind (Exp) /= N_Function_Call
4683 or else not Is_Entity_Name (Exp)
4684 or else not Treat_As_Volatile (Entity (Exp)))
4686 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4688 if Nkind (Exp) = N_Selected_Component
4689 and then Nkind (Prefix (Exp)) = N_Function_Call
4690 and then Is_Array_Type (Exp_Type)
4692 -- Avoid generating a variable-sized temporary, by generating
4693 -- the renaming declaration just for the function call. The
4694 -- transformation could be refined to apply only when the array
4695 -- component is constrained by a discriminant???
4698 Make_Selected_Component (Loc,
4699 Prefix => New_Occurrence_Of (Def_Id, Loc),
4700 Selector_Name => Selector_Name (Exp));
4703 Make_Object_Renaming_Declaration (Loc,
4704 Defining_Identifier => Def_Id,
4706 New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc),
4707 Name => Relocate_Node (Prefix (Exp))));
4710 Res := New_Reference_To (Def_Id, Loc);
4713 Make_Object_Renaming_Declaration (Loc,
4714 Defining_Identifier => Def_Id,
4715 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4716 Name => Relocate_Node (Exp)));
4720 -- If this is a packed reference, or a selected component with a
4721 -- non-standard representation, a reference to the temporary will
4722 -- be replaced by a copy of the original expression (see
4723 -- exp_ch2.Expand_Renaming). Otherwise the temporary must be
4724 -- elaborated by gigi, and is of course not to be replaced in-line
4725 -- by the expression it renames, which would defeat the purpose of
4726 -- removing the side-effect.
4728 if (Nkind (Exp) = N_Selected_Component
4729 or else Nkind (Exp) = N_Indexed_Component)
4730 and then Has_Non_Standard_Rep (Etype (Prefix (Exp)))
4734 Set_Is_Renaming_Of_Object (Def_Id, False);
4737 -- Otherwise we generate a reference to the value
4740 Ref_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
4743 Make_Full_Type_Declaration (Loc,
4744 Defining_Identifier => Ref_Type,
4746 Make_Access_To_Object_Definition (Loc,
4747 All_Present => True,
4748 Subtype_Indication =>
4749 New_Reference_To (Exp_Type, Loc)));
4752 Insert_Action (Exp, Ptr_Typ_Decl);
4754 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4755 Set_Etype (Def_Id, Exp_Type);
4758 Make_Explicit_Dereference (Loc,
4759 Prefix => New_Reference_To (Def_Id, Loc));
4761 if Nkind (E) = N_Explicit_Dereference then
4762 New_Exp := Relocate_Node (Prefix (E));
4764 E := Relocate_Node (E);
4765 New_Exp := Make_Reference (Loc, E);
4768 if Is_Delayed_Aggregate (E) then
4770 -- The expansion of nested aggregates is delayed until the
4771 -- enclosing aggregate is expanded. As aggregates are often
4772 -- qualified, the predicate applies to qualified expressions
4773 -- as well, indicating that the enclosing aggregate has not
4774 -- been expanded yet. At this point the aggregate is part of
4775 -- a stand-alone declaration, and must be fully expanded.
4777 if Nkind (E) = N_Qualified_Expression then
4778 Set_Expansion_Delayed (Expression (E), False);
4779 Set_Analyzed (Expression (E), False);
4781 Set_Expansion_Delayed (E, False);
4784 Set_Analyzed (E, False);
4788 Make_Object_Declaration (Loc,
4789 Defining_Identifier => Def_Id,
4790 Object_Definition => New_Reference_To (Ref_Type, Loc),
4791 Expression => New_Exp));
4794 -- Preserve the Assignment_OK flag in all copies, since at least
4795 -- one copy may be used in a context where this flag must be set
4796 -- (otherwise why would the flag be set in the first place).
4798 Set_Assignment_OK (Res, Assignment_OK (Exp));
4800 -- Finally rewrite the original expression and we are done
4803 Analyze_And_Resolve (Exp, Exp_Type);
4804 Scope_Suppress := Svg_Suppress;
4805 end Remove_Side_Effects;
4807 ---------------------------
4808 -- Represented_As_Scalar --
4809 ---------------------------
4811 function Represented_As_Scalar (T : Entity_Id) return Boolean is
4812 UT : constant Entity_Id := Underlying_Type (T);
4814 return Is_Scalar_Type (UT)
4815 or else (Is_Bit_Packed_Array (UT)
4816 and then Is_Scalar_Type (Packed_Array_Type (UT)));
4817 end Represented_As_Scalar;
4819 ------------------------------------
4820 -- Safe_Unchecked_Type_Conversion --
4821 ------------------------------------
4823 -- Note: this function knows quite a bit about the exact requirements
4824 -- of Gigi with respect to unchecked type conversions, and its code
4825 -- must be coordinated with any changes in Gigi in this area.
4827 -- The above requirements should be documented in Sinfo ???
4829 function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
4834 Pexp : constant Node_Id := Parent (Exp);
4837 -- If the expression is the RHS of an assignment or object declaration
4838 -- we are always OK because there will always be a target.
4840 -- Object renaming declarations, (generated for view conversions of
4841 -- actuals in inlined calls), like object declarations, provide an
4842 -- explicit type, and are safe as well.
4844 if (Nkind (Pexp) = N_Assignment_Statement
4845 and then Expression (Pexp) = Exp)
4846 or else Nkind (Pexp) = N_Object_Declaration
4847 or else Nkind (Pexp) = N_Object_Renaming_Declaration
4851 -- If the expression is the prefix of an N_Selected_Component
4852 -- we should also be OK because GCC knows to look inside the
4853 -- conversion except if the type is discriminated. We assume
4854 -- that we are OK anyway if the type is not set yet or if it is
4855 -- controlled since we can't afford to introduce a temporary in
4858 elsif Nkind (Pexp) = N_Selected_Component
4859 and then Prefix (Pexp) = Exp
4861 if No (Etype (Pexp)) then
4865 not Has_Discriminants (Etype (Pexp))
4866 or else Is_Constrained (Etype (Pexp));
4870 -- Set the output type, this comes from Etype if it is set, otherwise
4871 -- we take it from the subtype mark, which we assume was already
4874 if Present (Etype (Exp)) then
4875 Otyp := Etype (Exp);
4877 Otyp := Entity (Subtype_Mark (Exp));
4880 -- The input type always comes from the expression, and we assume
4881 -- this is indeed always analyzed, so we can simply get the Etype.
4883 Ityp := Etype (Expression (Exp));
4885 -- Initialize alignments to unknown so far
4890 -- Replace a concurrent type by its corresponding record type
4891 -- and each type by its underlying type and do the tests on those.
4892 -- The original type may be a private type whose completion is a
4893 -- concurrent type, so find the underlying type first.
4895 if Present (Underlying_Type (Otyp)) then
4896 Otyp := Underlying_Type (Otyp);
4899 if Present (Underlying_Type (Ityp)) then
4900 Ityp := Underlying_Type (Ityp);
4903 if Is_Concurrent_Type (Otyp) then
4904 Otyp := Corresponding_Record_Type (Otyp);
4907 if Is_Concurrent_Type (Ityp) then
4908 Ityp := Corresponding_Record_Type (Ityp);
4911 -- If the base types are the same, we know there is no problem since
4912 -- this conversion will be a noop.
4914 if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
4917 -- Same if this is an upwards conversion of an untagged type, and there
4918 -- are no constraints involved (could be more general???)
4920 elsif Etype (Ityp) = Otyp
4921 and then not Is_Tagged_Type (Ityp)
4922 and then not Has_Discriminants (Ityp)
4923 and then No (First_Rep_Item (Base_Type (Ityp)))
4927 -- If the size of output type is known at compile time, there is
4928 -- never a problem. Note that unconstrained records are considered
4929 -- to be of known size, but we can't consider them that way here,
4930 -- because we are talking about the actual size of the object.
4932 -- We also make sure that in addition to the size being known, we do
4933 -- not have a case which might generate an embarrassingly large temp
4934 -- in stack checking mode.
4936 elsif Size_Known_At_Compile_Time (Otyp)
4938 (not Stack_Checking_Enabled
4939 or else not May_Generate_Large_Temp (Otyp))
4940 and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
4944 -- If either type is tagged, then we know the alignment is OK so
4945 -- Gigi will be able to use pointer punning.
4947 elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
4950 -- If either type is a limited record type, we cannot do a copy, so
4951 -- say safe since there's nothing else we can do.
4953 elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
4956 -- Conversions to and from packed array types are always ignored and
4959 elsif Is_Packed_Array_Type (Otyp)
4960 or else Is_Packed_Array_Type (Ityp)
4965 -- The only other cases known to be safe is if the input type's
4966 -- alignment is known to be at least the maximum alignment for the
4967 -- target or if both alignments are known and the output type's
4968 -- alignment is no stricter than the input's. We can use the alignment
4969 -- of the component type of an array if a type is an unpacked
4972 if Present (Alignment_Clause (Otyp)) then
4973 Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
4975 elsif Is_Array_Type (Otyp)
4976 and then Present (Alignment_Clause (Component_Type (Otyp)))
4978 Oalign := Expr_Value (Expression (Alignment_Clause
4979 (Component_Type (Otyp))));
4982 if Present (Alignment_Clause (Ityp)) then
4983 Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
4985 elsif Is_Array_Type (Ityp)
4986 and then Present (Alignment_Clause (Component_Type (Ityp)))
4988 Ialign := Expr_Value (Expression (Alignment_Clause
4989 (Component_Type (Ityp))));
4992 if Ialign /= No_Uint and then Ialign > Maximum_Alignment then
4995 elsif Ialign /= No_Uint and then Oalign /= No_Uint
4996 and then Ialign <= Oalign
5000 -- Otherwise, Gigi cannot handle this and we must make a temporary
5005 end Safe_Unchecked_Type_Conversion;
5007 ---------------------------------
5008 -- Set_Current_Value_Condition --
5009 ---------------------------------
5011 -- Note: the implementation of this procedure is very closely tied to the
5012 -- implementation of Get_Current_Value_Condition. Here we set required
5013 -- Current_Value fields, and in Get_Current_Value_Condition, we interpret
5014 -- them, so they must have a consistent view.
5016 procedure Set_Current_Value_Condition (Cnode : Node_Id) is
5018 procedure Set_Entity_Current_Value (N : Node_Id);
5019 -- If N is an entity reference, where the entity is of an appropriate
5020 -- kind, then set the current value of this entity to Cnode, unless
5021 -- there is already a definite value set there.
5023 procedure Set_Expression_Current_Value (N : Node_Id);
5024 -- If N is of an appropriate form, sets an appropriate entry in current
5025 -- value fields of relevant entities. Multiple entities can be affected
5026 -- in the case of an AND or AND THEN.
5028 ------------------------------
5029 -- Set_Entity_Current_Value --
5030 ------------------------------
5032 procedure Set_Entity_Current_Value (N : Node_Id) is
5034 if Is_Entity_Name (N) then
5036 Ent : constant Entity_Id := Entity (N);
5039 -- Don't capture if not safe to do so
5041 if not Safe_To_Capture_Value (N, Ent, Cond => True) then
5045 -- Here we have a case where the Current_Value field may
5046 -- need to be set. We set it if it is not already set to a
5047 -- compile time expression value.
5049 -- Note that this represents a decision that one condition
5050 -- blots out another previous one. That's certainly right
5051 -- if they occur at the same level. If the second one is
5052 -- nested, then the decision is neither right nor wrong (it
5053 -- would be equally OK to leave the outer one in place, or
5054 -- take the new inner one. Really we should record both, but
5055 -- our data structures are not that elaborate.
5057 if Nkind (Current_Value (Ent)) not in N_Subexpr then
5058 Set_Current_Value (Ent, Cnode);
5062 end Set_Entity_Current_Value;
5064 ----------------------------------
5065 -- Set_Expression_Current_Value --
5066 ----------------------------------
5068 procedure Set_Expression_Current_Value (N : Node_Id) is
5074 -- Loop to deal with (ignore for now) any NOT operators present. The
5075 -- presence of NOT operators will be handled properly when we call
5076 -- Get_Current_Value_Condition.
5078 while Nkind (Cond) = N_Op_Not loop
5079 Cond := Right_Opnd (Cond);
5082 -- For an AND or AND THEN, recursively process operands
5084 if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then
5085 Set_Expression_Current_Value (Left_Opnd (Cond));
5086 Set_Expression_Current_Value (Right_Opnd (Cond));
5090 -- Check possible relational operator
5092 if Nkind (Cond) in N_Op_Compare then
5093 if Compile_Time_Known_Value (Right_Opnd (Cond)) then
5094 Set_Entity_Current_Value (Left_Opnd (Cond));
5095 elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then
5096 Set_Entity_Current_Value (Right_Opnd (Cond));
5099 -- Check possible boolean variable reference
5102 Set_Entity_Current_Value (Cond);
5104 end Set_Expression_Current_Value;
5106 -- Start of processing for Set_Current_Value_Condition
5109 Set_Expression_Current_Value (Condition (Cnode));
5110 end Set_Current_Value_Condition;
5112 --------------------------
5113 -- Set_Elaboration_Flag --
5114 --------------------------
5116 procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
5117 Loc : constant Source_Ptr := Sloc (N);
5118 Ent : constant Entity_Id := Elaboration_Entity (Spec_Id);
5122 if Present (Ent) then
5124 -- Nothing to do if at the compilation unit level, because in this
5125 -- case the flag is set by the binder generated elaboration routine.
5127 if Nkind (Parent (N)) = N_Compilation_Unit then
5130 -- Here we do need to generate an assignment statement
5133 Check_Restriction (No_Elaboration_Code, N);
5135 Make_Assignment_Statement (Loc,
5136 Name => New_Occurrence_Of (Ent, Loc),
5137 Expression => New_Occurrence_Of (Standard_True, Loc));
5139 if Nkind (Parent (N)) = N_Subunit then
5140 Insert_After (Corresponding_Stub (Parent (N)), Asn);
5142 Insert_After (N, Asn);
5147 -- Kill current value indication. This is necessary because
5148 -- the tests of this flag are inserted out of sequence and must
5149 -- not pick up bogus indications of the wrong constant value.
5151 Set_Current_Value (Ent, Empty);
5154 end Set_Elaboration_Flag;
5156 ----------------------------
5157 -- Set_Renamed_Subprogram --
5158 ----------------------------
5160 procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is
5162 -- If input node is an identifier, we can just reset it
5164 if Nkind (N) = N_Identifier then
5165 Set_Chars (N, Chars (E));
5168 -- Otherwise we have to do a rewrite, preserving Comes_From_Source
5172 CS : constant Boolean := Comes_From_Source (N);
5174 Rewrite (N, Make_Identifier (Sloc (N), Chars => Chars (E)));
5176 Set_Comes_From_Source (N, CS);
5177 Set_Analyzed (N, True);
5180 end Set_Renamed_Subprogram;
5182 --------------------------
5183 -- Target_Has_Fixed_Ops --
5184 --------------------------
5186 Integer_Sized_Small : Ureal;
5187 -- Set to 2.0 ** -(Integer'Size - 1) the first time that this
5188 -- function is called (we don't want to compute it more than once!)
5190 Long_Integer_Sized_Small : Ureal;
5191 -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this
5192 -- functoin is called (we don't want to compute it more than once)
5194 First_Time_For_THFO : Boolean := True;
5195 -- Set to False after first call (if Fractional_Fixed_Ops_On_Target)
5197 function Target_Has_Fixed_Ops
5198 (Left_Typ : Entity_Id;
5199 Right_Typ : Entity_Id;
5200 Result_Typ : Entity_Id) return Boolean
5202 function Is_Fractional_Type (Typ : Entity_Id) return Boolean;
5203 -- Return True if the given type is a fixed-point type with a small
5204 -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have
5205 -- an absolute value less than 1.0. This is currently limited
5206 -- to fixed-point types that map to Integer or Long_Integer.
5208 ------------------------
5209 -- Is_Fractional_Type --
5210 ------------------------
5212 function Is_Fractional_Type (Typ : Entity_Id) return Boolean is
5214 if Esize (Typ) = Standard_Integer_Size then
5215 return Small_Value (Typ) = Integer_Sized_Small;
5217 elsif Esize (Typ) = Standard_Long_Integer_Size then
5218 return Small_Value (Typ) = Long_Integer_Sized_Small;
5223 end Is_Fractional_Type;
5225 -- Start of processing for Target_Has_Fixed_Ops
5228 -- Return False if Fractional_Fixed_Ops_On_Target is false
5230 if not Fractional_Fixed_Ops_On_Target then
5234 -- Here the target has Fractional_Fixed_Ops, if first time, compute
5235 -- standard constants used by Is_Fractional_Type.
5237 if First_Time_For_THFO then
5238 First_Time_For_THFO := False;
5240 Integer_Sized_Small :=
5243 Den => UI_From_Int (Standard_Integer_Size - 1),
5246 Long_Integer_Sized_Small :=
5249 Den => UI_From_Int (Standard_Long_Integer_Size - 1),
5253 -- Return True if target supports fixed-by-fixed multiply/divide
5254 -- for fractional fixed-point types (see Is_Fractional_Type) and
5255 -- the operand and result types are equivalent fractional types.
5257 return Is_Fractional_Type (Base_Type (Left_Typ))
5258 and then Is_Fractional_Type (Base_Type (Right_Typ))
5259 and then Is_Fractional_Type (Base_Type (Result_Typ))
5260 and then Esize (Left_Typ) = Esize (Right_Typ)
5261 and then Esize (Left_Typ) = Esize (Result_Typ);
5262 end Target_Has_Fixed_Ops;
5264 ------------------------------------------
5265 -- Type_May_Have_Bit_Aligned_Components --
5266 ------------------------------------------
5268 function Type_May_Have_Bit_Aligned_Components
5269 (Typ : Entity_Id) return Boolean
5272 -- Array type, check component type
5274 if Is_Array_Type (Typ) then
5276 Type_May_Have_Bit_Aligned_Components (Component_Type (Typ));
5278 -- Record type, check components
5280 elsif Is_Record_Type (Typ) then
5285 E := First_Component_Or_Discriminant (Typ);
5286 while Present (E) loop
5287 if Component_May_Be_Bit_Aligned (E)
5288 or else Type_May_Have_Bit_Aligned_Components (Etype (E))
5293 Next_Component_Or_Discriminant (E);
5299 -- Type other than array or record is always OK
5304 end Type_May_Have_Bit_Aligned_Components;
5306 ----------------------------
5307 -- Wrap_Cleanup_Procedure --
5308 ----------------------------
5310 procedure Wrap_Cleanup_Procedure (N : Node_Id) is
5311 Loc : constant Source_Ptr := Sloc (N);
5312 Stseq : constant Node_Id := Handled_Statement_Sequence (N);
5313 Stmts : constant List_Id := Statements (Stseq);
5316 if Abort_Allowed then
5317 Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
5318 Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));
5320 end Wrap_Cleanup_Procedure;