1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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 -- Corresponding_Runtime_Package --
953 -----------------------------------
955 function Corresponding_Runtime_Package (Typ : Entity_Id) return RTU_Id is
956 Pkg_Id : RTU_Id := RTU_Null;
959 pragma Assert (Is_Concurrent_Type (Typ));
961 if Ekind (Typ) in Protected_Kind then
963 or else Has_Interrupt_Handler (Typ)
964 or else (Has_Attach_Handler (Typ)
965 and then not Restricted_Profile)
967 -- A protected type without entries that covers an interface and
968 -- overrides the abstract routines with protected procedures is
969 -- considered equivalent to a protected type with entries in the
970 -- context of dispatching select statements. It is sufficient to
971 -- check for the presence of an interface list in the declaration
972 -- node to recognize this case.
974 or else Present (Interface_List (Parent (Typ)))
977 or else Restriction_Active (No_Entry_Queue) = False
978 or else Number_Entries (Typ) > 1
979 or else (Has_Attach_Handler (Typ)
980 and then not Restricted_Profile)
982 Pkg_Id := System_Tasking_Protected_Objects_Entries;
984 Pkg_Id := System_Tasking_Protected_Objects_Single_Entry;
988 Pkg_Id := System_Tasking_Protected_Objects;
993 end Corresponding_Runtime_Package;
995 -------------------------------
996 -- Convert_To_Actual_Subtype --
997 -------------------------------
999 procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is
1003 Act_ST := Get_Actual_Subtype (Exp);
1005 if Act_ST = Etype (Exp) then
1010 Convert_To (Act_ST, Relocate_Node (Exp)));
1011 Analyze_And_Resolve (Exp, Act_ST);
1013 end Convert_To_Actual_Subtype;
1015 -----------------------------------
1016 -- Current_Sem_Unit_Declarations --
1017 -----------------------------------
1019 function Current_Sem_Unit_Declarations return List_Id is
1020 U : Node_Id := Unit (Cunit (Current_Sem_Unit));
1024 -- If the current unit is a package body, locate the visible
1025 -- declarations of the package spec.
1027 if Nkind (U) = N_Package_Body then
1028 U := Unit (Library_Unit (Cunit (Current_Sem_Unit)));
1031 if Nkind (U) = N_Package_Declaration then
1032 U := Specification (U);
1033 Decls := Visible_Declarations (U);
1037 Set_Visible_Declarations (U, Decls);
1041 Decls := Declarations (U);
1045 Set_Declarations (U, Decls);
1050 end Current_Sem_Unit_Declarations;
1052 -----------------------
1053 -- Duplicate_Subexpr --
1054 -----------------------
1056 function Duplicate_Subexpr
1058 Name_Req : Boolean := False) return Node_Id
1061 Remove_Side_Effects (Exp, Name_Req);
1062 return New_Copy_Tree (Exp);
1063 end Duplicate_Subexpr;
1065 ---------------------------------
1066 -- Duplicate_Subexpr_No_Checks --
1067 ---------------------------------
1069 function Duplicate_Subexpr_No_Checks
1071 Name_Req : Boolean := False) return Node_Id
1076 Remove_Side_Effects (Exp, Name_Req);
1077 New_Exp := New_Copy_Tree (Exp);
1078 Remove_Checks (New_Exp);
1080 end Duplicate_Subexpr_No_Checks;
1082 -----------------------------------
1083 -- Duplicate_Subexpr_Move_Checks --
1084 -----------------------------------
1086 function Duplicate_Subexpr_Move_Checks
1088 Name_Req : Boolean := False) return Node_Id
1093 Remove_Side_Effects (Exp, Name_Req);
1094 New_Exp := New_Copy_Tree (Exp);
1095 Remove_Checks (Exp);
1097 end Duplicate_Subexpr_Move_Checks;
1099 --------------------
1100 -- Ensure_Defined --
1101 --------------------
1103 procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is
1107 -- An itype reference must only be created if this is a local
1108 -- itype, so that gigi can elaborate it on the proper objstack.
1111 and then Scope (Typ) = Current_Scope
1113 IR := Make_Itype_Reference (Sloc (N));
1114 Set_Itype (IR, Typ);
1115 Insert_Action (N, IR);
1119 ---------------------
1120 -- Evolve_And_Then --
1121 ---------------------
1123 procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is
1129 Make_And_Then (Sloc (Cond1),
1131 Right_Opnd => Cond1);
1133 end Evolve_And_Then;
1135 --------------------
1136 -- Evolve_Or_Else --
1137 --------------------
1139 procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is
1145 Make_Or_Else (Sloc (Cond1),
1147 Right_Opnd => Cond1);
1151 ------------------------------
1152 -- Expand_Subtype_From_Expr --
1153 ------------------------------
1155 -- This function is applicable for both static and dynamic allocation of
1156 -- objects which are constrained by an initial expression. Basically it
1157 -- transforms an unconstrained subtype indication into a constrained one.
1158 -- The expression may also be transformed in certain cases in order to
1159 -- avoid multiple evaluation. In the static allocation case, the general
1164 -- is transformed into
1166 -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr;
1168 -- Here are the main cases :
1170 -- <if Expr is a Slice>
1171 -- Val : T ([Index_Subtype (Expr)]) := Expr;
1173 -- <elsif Expr is a String Literal>
1174 -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
1176 -- <elsif Expr is Constrained>
1177 -- subtype T is Type_Of_Expr
1180 -- <elsif Expr is an entity_name>
1181 -- Val : T (constraints taken from Expr) := Expr;
1184 -- type Axxx is access all T;
1185 -- Rval : Axxx := Expr'ref;
1186 -- Val : T (constraints taken from Rval) := Rval.all;
1188 -- ??? note: when the Expression is allocated in the secondary stack
1189 -- we could use it directly instead of copying it by declaring
1190 -- Val : T (...) renames Rval.all
1192 procedure Expand_Subtype_From_Expr
1194 Unc_Type : Entity_Id;
1195 Subtype_Indic : Node_Id;
1198 Loc : constant Source_Ptr := Sloc (N);
1199 Exp_Typ : constant Entity_Id := Etype (Exp);
1203 -- In general we cannot build the subtype if expansion is disabled,
1204 -- because internal entities may not have been defined. However, to
1205 -- avoid some cascaded errors, we try to continue when the expression
1206 -- is an array (or string), because it is safe to compute the bounds.
1207 -- It is in fact required to do so even in a generic context, because
1208 -- there may be constants that depend on bounds of string literal.
1210 if not Expander_Active
1211 and then (No (Etype (Exp))
1212 or else Base_Type (Etype (Exp)) /= Standard_String)
1217 if Nkind (Exp) = N_Slice then
1219 Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ));
1222 Rewrite (Subtype_Indic,
1223 Make_Subtype_Indication (Loc,
1224 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1226 Make_Index_Or_Discriminant_Constraint (Loc,
1227 Constraints => New_List
1228 (New_Reference_To (Slice_Type, Loc)))));
1230 -- This subtype indication may be used later for constraint checks
1231 -- we better make sure that if a variable was used as a bound of
1232 -- of the original slice, its value is frozen.
1234 Force_Evaluation (Low_Bound (Scalar_Range (Slice_Type)));
1235 Force_Evaluation (High_Bound (Scalar_Range (Slice_Type)));
1238 elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then
1239 Rewrite (Subtype_Indic,
1240 Make_Subtype_Indication (Loc,
1241 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1243 Make_Index_Or_Discriminant_Constraint (Loc,
1244 Constraints => New_List (
1245 Make_Literal_Range (Loc,
1246 Literal_Typ => Exp_Typ)))));
1248 elsif Is_Constrained (Exp_Typ)
1249 and then not Is_Class_Wide_Type (Unc_Type)
1251 if Is_Itype (Exp_Typ) then
1253 -- Within an initialization procedure, a selected component
1254 -- denotes a component of the enclosing record, and it appears
1255 -- as an actual in a call to its own initialization procedure.
1256 -- If this component depends on the outer discriminant, we must
1257 -- generate the proper actual subtype for it.
1259 if Nkind (Exp) = N_Selected_Component
1260 and then Within_Init_Proc
1263 Decl : constant Node_Id :=
1264 Build_Actual_Subtype_Of_Component (Exp_Typ, Exp);
1266 if Present (Decl) then
1267 Insert_Action (N, Decl);
1268 T := Defining_Identifier (Decl);
1274 -- No need to generate a new one (new what???)
1282 Make_Defining_Identifier (Loc,
1283 Chars => New_Internal_Name ('T'));
1286 Make_Subtype_Declaration (Loc,
1287 Defining_Identifier => T,
1288 Subtype_Indication => New_Reference_To (Exp_Typ, Loc)));
1290 -- This type is marked as an itype even though it has an
1291 -- explicit declaration because otherwise it can be marked
1292 -- with Is_Generic_Actual_Type and generate spurious errors.
1293 -- (see sem_ch8.Analyze_Package_Renaming and sem_type.covers)
1296 Set_Associated_Node_For_Itype (T, Exp);
1299 Rewrite (Subtype_Indic, New_Reference_To (T, Loc));
1301 -- nothing needs to be done for private types with unknown discriminants
1302 -- if the underlying type is not an unconstrained composite type.
1304 elsif Is_Private_Type (Unc_Type)
1305 and then Has_Unknown_Discriminants (Unc_Type)
1306 and then (not Is_Composite_Type (Underlying_Type (Unc_Type))
1307 or else Is_Constrained (Underlying_Type (Unc_Type)))
1311 -- Nothing to be done for derived types with unknown discriminants if
1312 -- the parent type also has unknown discriminants.
1314 elsif Is_Record_Type (Unc_Type)
1315 and then not Is_Class_Wide_Type (Unc_Type)
1316 and then Has_Unknown_Discriminants (Unc_Type)
1317 and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type))
1321 -- In Ada95, Nothing to be done if the type of the expression is
1322 -- limited, because in this case the expression cannot be copied,
1323 -- and its use can only be by reference.
1325 -- In Ada2005, the context can be an object declaration whose expression
1326 -- is a function that returns in place. If the nominal subtype has
1327 -- unknown discriminants, the call still provides constraints on the
1328 -- object, and we have to create an actual subtype from it.
1330 -- If the type is class-wide, the expression is dynamically tagged and
1331 -- we do not create an actual subtype either. Ditto for an interface.
1333 elsif Is_Limited_Type (Exp_Typ)
1335 (Is_Class_Wide_Type (Exp_Typ)
1336 or else Is_Interface (Exp_Typ)
1337 or else not Has_Unknown_Discriminants (Exp_Typ)
1338 or else not Is_Composite_Type (Unc_Type))
1342 -- For limited interfaces, nothing to be done
1344 -- This branch may be redundant once the limited interface issue is
1347 elsif Is_Interface (Exp_Typ)
1348 and then Is_Limited_Interface (Exp_Typ)
1352 -- For limited objects initialized with build in place function calls,
1353 -- nothing to be done; otherwise we prematurely introduce an N_Reference
1354 -- node in the expression initializing the object, which breaks the
1355 -- circuitry that detects and adds the additional arguments to the
1358 elsif Is_Build_In_Place_Function_Call (Exp) then
1362 Remove_Side_Effects (Exp);
1363 Rewrite (Subtype_Indic,
1364 Make_Subtype_From_Expr (Exp, Unc_Type));
1366 end Expand_Subtype_From_Expr;
1368 ------------------------
1369 -- Find_Interface_ADT --
1370 ------------------------
1372 function Find_Interface_ADT
1374 Iface : Entity_Id) return Elmt_Id
1377 Found : Boolean := False;
1378 Typ : Entity_Id := T;
1380 procedure Find_Secondary_Table (Typ : Entity_Id);
1381 -- Internal subprogram used to recursively climb to the ancestors
1383 --------------------------
1384 -- Find_Secondary_Table --
1385 --------------------------
1387 procedure Find_Secondary_Table (Typ : Entity_Id) is
1392 pragma Assert (Typ /= Iface);
1394 -- Climb to the ancestor (if any) handling synchronized interface
1395 -- derivations and private types
1397 if Is_Concurrent_Record_Type (Typ) then
1399 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1402 if Is_Non_Empty_List (Iface_List) then
1403 Find_Secondary_Table (Etype (First (Iface_List)));
1407 elsif Present (Full_View (Etype (Typ))) then
1408 if Full_View (Etype (Typ)) /= Typ then
1409 Find_Secondary_Table (Full_View (Etype (Typ)));
1412 elsif Etype (Typ) /= Typ then
1413 Find_Secondary_Table (Etype (Typ));
1416 -- Traverse the list of interfaces implemented by the type
1419 and then Present (Abstract_Interfaces (Typ))
1420 and then not Is_Empty_Elmt_List (Abstract_Interfaces (Typ))
1422 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1423 while Present (AI_Elmt) loop
1424 AI := Node (AI_Elmt);
1426 if AI = Iface or else Is_Ancestor (Iface, AI) then
1431 -- Document what is going on here, why four Next's???
1437 Next_Elmt (AI_Elmt);
1440 end Find_Secondary_Table;
1442 -- Start of processing for Find_Interface_ADT
1445 pragma Assert (Is_Interface (Iface));
1447 -- Handle private types
1449 if Has_Private_Declaration (Typ)
1450 and then Present (Full_View (Typ))
1452 Typ := Full_View (Typ);
1455 -- Handle access types
1457 if Is_Access_Type (Typ) then
1458 Typ := Directly_Designated_Type (Typ);
1461 -- Handle task and protected types implementing interfaces
1463 if Is_Concurrent_Type (Typ) then
1464 Typ := Corresponding_Record_Type (Typ);
1468 (not Is_Class_Wide_Type (Typ)
1469 and then Ekind (Typ) /= E_Incomplete_Type);
1471 ADT := Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Typ))));
1472 pragma Assert (Present (Node (ADT)));
1473 Find_Secondary_Table (Typ);
1474 pragma Assert (Found);
1476 end Find_Interface_ADT;
1478 ------------------------
1479 -- Find_Interface_Tag --
1480 ------------------------
1482 function Find_Interface_Tag
1484 Iface : Entity_Id) return Entity_Id
1487 Found : Boolean := False;
1488 Typ : Entity_Id := T;
1490 Is_Primary_Tag : Boolean := False;
1492 Is_Sync_Typ : Boolean := False;
1493 -- In case of non concurrent-record-types each parent-type has the
1494 -- tags associated with the interface types that are not implemented
1495 -- by the ancestors; concurrent-record-types have their whole list of
1496 -- interface tags (and this case requires some special management).
1498 procedure Find_Tag (Typ : Entity_Id);
1499 -- Internal subprogram used to recursively climb to the ancestors
1505 procedure Find_Tag (Typ : Entity_Id) is
1510 -- Check if the interface is an immediate ancestor of the type and
1511 -- therefore shares the main tag.
1515 Is_Primary_Tag := True;
1518 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1519 AI_Tag := First_Tag_Component (Typ);
1526 -- Handle synchronized interface derivations
1528 if Is_Concurrent_Record_Type (Typ) then
1530 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1532 if Is_Non_Empty_List (Iface_List) then
1533 Find_Tag (Etype (First (Iface_List)));
1537 -- Climb to the root type handling private types
1539 elsif Present (Full_View (Etype (Typ))) then
1540 if Full_View (Etype (Typ)) /= Typ then
1541 Find_Tag (Full_View (Etype (Typ)));
1544 elsif Etype (Typ) /= Typ then
1545 Find_Tag (Etype (Typ));
1548 -- Traverse the list of interfaces implemented by the type
1551 and then Present (Abstract_Interfaces (Typ))
1552 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1554 -- Skip the tag associated with the primary table
1556 if not Is_Sync_Typ then
1558 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1559 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1560 pragma Assert (Present (AI_Tag));
1563 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1564 while Present (AI_Elmt) loop
1565 AI := Node (AI_Elmt);
1567 if AI = Iface or else Is_Ancestor (Iface, AI) then
1572 AI_Tag := Next_Tag_Component (AI_Tag);
1573 Next_Elmt (AI_Elmt);
1578 -- Start of processing for Find_Interface_Tag
1581 pragma Assert (Is_Interface (Iface));
1583 -- Handle private types
1585 if Has_Private_Declaration (Typ)
1586 and then Present (Full_View (Typ))
1588 Typ := Full_View (Typ);
1591 -- Handle access types
1593 if Is_Access_Type (Typ) then
1594 Typ := Directly_Designated_Type (Typ);
1597 -- Handle task and protected types implementing interfaces
1599 if Is_Concurrent_Type (Typ) then
1600 Typ := Corresponding_Record_Type (Typ);
1603 if Is_Class_Wide_Type (Typ) then
1607 -- Handle entities from the limited view
1609 if Ekind (Typ) = E_Incomplete_Type then
1610 pragma Assert (Present (Non_Limited_View (Typ)));
1611 Typ := Non_Limited_View (Typ);
1614 if not Is_Concurrent_Record_Type (Typ) then
1616 pragma Assert (Found);
1619 -- Concurrent record types
1622 Is_Sync_Typ := True;
1623 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1625 pragma Assert (Found);
1627 if Is_Primary_Tag then
1628 return First_Tag_Component (Typ);
1633 end Find_Interface_Tag;
1635 --------------------
1636 -- Find_Interface --
1637 --------------------
1639 function Find_Interface
1641 Comp : Entity_Id) return Entity_Id
1644 Found : Boolean := False;
1646 Typ : Entity_Id := T;
1648 Is_Sync_Typ : Boolean := False;
1649 -- In case of non concurrent-record-types each parent-type has the
1650 -- tags associated with the interface types that are not implemented
1651 -- by the ancestors; concurrent-record-types have their whole list of
1652 -- interface tags (and this case requires some special management).
1654 procedure Find_Iface (Typ : Entity_Id);
1655 -- Internal subprogram used to recursively climb to the ancestors
1661 procedure Find_Iface (Typ : Entity_Id) is
1665 -- Climb to the root type
1667 -- Handle synchronized interface derivations
1669 if Is_Concurrent_Record_Type (Typ) then
1671 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1673 if Is_Non_Empty_List (Iface_List) then
1674 Find_Iface (Etype (First (Iface_List)));
1678 -- Handle the common case
1680 elsif Etype (Typ) /= Typ then
1681 pragma Assert (not Present (Full_View (Etype (Typ))));
1682 Find_Iface (Etype (Typ));
1685 -- Traverse the list of interfaces implemented by the type
1688 and then Present (Abstract_Interfaces (Typ))
1689 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1691 -- Skip the tag associated with the primary table
1693 if not Is_Sync_Typ then
1695 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1696 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1697 pragma Assert (Present (AI_Tag));
1700 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1701 while Present (AI_Elmt) loop
1702 if AI_Tag = Comp then
1703 Iface := Node (AI_Elmt);
1708 AI_Tag := Next_Tag_Component (AI_Tag);
1709 Next_Elmt (AI_Elmt);
1714 -- Start of processing for Find_Interface
1717 -- Handle private types
1719 if Has_Private_Declaration (Typ)
1720 and then Present (Full_View (Typ))
1722 Typ := Full_View (Typ);
1725 -- Handle access types
1727 if Is_Access_Type (Typ) then
1728 Typ := Directly_Designated_Type (Typ);
1731 -- Handle task and protected types implementing interfaces
1733 if Is_Concurrent_Type (Typ) then
1734 Typ := Corresponding_Record_Type (Typ);
1737 if Is_Class_Wide_Type (Typ) then
1741 -- Handle entities from the limited view
1743 if Ekind (Typ) = E_Incomplete_Type then
1744 pragma Assert (Present (Non_Limited_View (Typ)));
1745 Typ := Non_Limited_View (Typ);
1748 if Is_Concurrent_Record_Type (Typ) then
1749 Is_Sync_Typ := True;
1750 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1754 pragma Assert (Found);
1762 function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is
1764 Typ : Entity_Id := T;
1768 if Is_Class_Wide_Type (Typ) then
1769 Typ := Root_Type (Typ);
1772 Typ := Underlying_Type (Typ);
1774 -- Loop through primitive operations
1776 Prim := First_Elmt (Primitive_Operations (Typ));
1777 while Present (Prim) loop
1780 -- We can retrieve primitive operations by name if it is an internal
1781 -- name. For equality we must check that both of its operands have
1782 -- the same type, to avoid confusion with user-defined equalities
1783 -- than may have a non-symmetric signature.
1785 exit when Chars (Op) = Name
1788 or else Etype (First_Entity (Op)) = Etype (Last_Entity (Op)));
1791 pragma Assert (Present (Prim));
1801 function Find_Prim_Op
1803 Name : TSS_Name_Type) return Entity_Id
1806 Typ : Entity_Id := T;
1809 if Is_Class_Wide_Type (Typ) then
1810 Typ := Root_Type (Typ);
1813 Typ := Underlying_Type (Typ);
1815 Prim := First_Elmt (Primitive_Operations (Typ));
1816 while not Is_TSS (Node (Prim), Name) loop
1818 pragma Assert (Present (Prim));
1824 ----------------------------
1825 -- Find_Protection_Object --
1826 ----------------------------
1828 function Find_Protection_Object (Scop : Entity_Id) return Entity_Id is
1833 while Present (S) loop
1834 if (Ekind (S) = E_Entry
1835 or else Ekind (S) = E_Entry_Family
1836 or else Ekind (S) = E_Function
1837 or else Ekind (S) = E_Procedure)
1838 and then Present (Protection_Object (S))
1840 return Protection_Object (S);
1846 -- If we do not find a Protection object in the scope chain, then
1847 -- something has gone wrong, most likely the object was never created.
1849 raise Program_Error;
1850 end Find_Protection_Object;
1852 ----------------------
1853 -- Force_Evaluation --
1854 ----------------------
1856 procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is
1858 Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True);
1859 end Force_Evaluation;
1861 ------------------------
1862 -- Generate_Poll_Call --
1863 ------------------------
1865 procedure Generate_Poll_Call (N : Node_Id) is
1867 -- No poll call if polling not active
1869 if not Polling_Required then
1872 -- Otherwise generate require poll call
1875 Insert_Before_And_Analyze (N,
1876 Make_Procedure_Call_Statement (Sloc (N),
1877 Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N))));
1879 end Generate_Poll_Call;
1881 ---------------------------------
1882 -- Get_Current_Value_Condition --
1883 ---------------------------------
1885 -- Note: the implementation of this procedure is very closely tied to the
1886 -- implementation of Set_Current_Value_Condition. In the Get procedure, we
1887 -- interpret Current_Value fields set by the Set procedure, so the two
1888 -- procedures need to be closely coordinated.
1890 procedure Get_Current_Value_Condition
1895 Loc : constant Source_Ptr := Sloc (Var);
1896 Ent : constant Entity_Id := Entity (Var);
1898 procedure Process_Current_Value_Condition
1901 -- N is an expression which holds either True (S = True) or False (S =
1902 -- False) in the condition. This procedure digs out the expression and
1903 -- if it refers to Ent, sets Op and Val appropriately.
1905 -------------------------------------
1906 -- Process_Current_Value_Condition --
1907 -------------------------------------
1909 procedure Process_Current_Value_Condition
1920 -- Deal with NOT operators, inverting sense
1922 while Nkind (Cond) = N_Op_Not loop
1923 Cond := Right_Opnd (Cond);
1927 -- Deal with AND THEN and AND cases
1929 if Nkind (Cond) = N_And_Then
1930 or else Nkind (Cond) = N_Op_And
1932 -- Don't ever try to invert a condition that is of the form
1933 -- of an AND or AND THEN (since we are not doing sufficiently
1934 -- general processing to allow this).
1936 if Sens = False then
1942 -- Recursively process AND and AND THEN branches
1944 Process_Current_Value_Condition (Left_Opnd (Cond), True);
1946 if Op /= N_Empty then
1950 Process_Current_Value_Condition (Right_Opnd (Cond), True);
1953 -- Case of relational operator
1955 elsif Nkind (Cond) in N_Op_Compare then
1958 -- Invert sense of test if inverted test
1960 if Sens = False then
1962 when N_Op_Eq => Op := N_Op_Ne;
1963 when N_Op_Ne => Op := N_Op_Eq;
1964 when N_Op_Lt => Op := N_Op_Ge;
1965 when N_Op_Gt => Op := N_Op_Le;
1966 when N_Op_Le => Op := N_Op_Gt;
1967 when N_Op_Ge => Op := N_Op_Lt;
1968 when others => raise Program_Error;
1972 -- Case of entity op value
1974 if Is_Entity_Name (Left_Opnd (Cond))
1975 and then Ent = Entity (Left_Opnd (Cond))
1976 and then Compile_Time_Known_Value (Right_Opnd (Cond))
1978 Val := Right_Opnd (Cond);
1980 -- Case of value op entity
1982 elsif Is_Entity_Name (Right_Opnd (Cond))
1983 and then Ent = Entity (Right_Opnd (Cond))
1984 and then Compile_Time_Known_Value (Left_Opnd (Cond))
1986 Val := Left_Opnd (Cond);
1988 -- We are effectively swapping operands
1991 when N_Op_Eq => null;
1992 when N_Op_Ne => null;
1993 when N_Op_Lt => Op := N_Op_Gt;
1994 when N_Op_Gt => Op := N_Op_Lt;
1995 when N_Op_Le => Op := N_Op_Ge;
1996 when N_Op_Ge => Op := N_Op_Le;
1997 when others => raise Program_Error;
2006 -- Case of Boolean variable reference, return as though the
2007 -- reference had said var = True.
2010 if Is_Entity_Name (Cond)
2011 and then Ent = Entity (Cond)
2013 Val := New_Occurrence_Of (Standard_True, Sloc (Cond));
2015 if Sens = False then
2022 end Process_Current_Value_Condition;
2024 -- Start of processing for Get_Current_Value_Condition
2030 -- Immediate return, nothing doing, if this is not an object
2032 if Ekind (Ent) not in Object_Kind then
2036 -- Otherwise examine current value
2039 CV : constant Node_Id := Current_Value (Ent);
2044 -- If statement. Condition is known true in THEN section, known False
2045 -- in any ELSIF or ELSE part, and unknown outside the IF statement.
2047 if Nkind (CV) = N_If_Statement then
2049 -- Before start of IF statement
2051 if Loc < Sloc (CV) then
2054 -- After end of IF statement
2056 elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
2060 -- At this stage we know that we are within the IF statement, but
2061 -- unfortunately, the tree does not record the SLOC of the ELSE so
2062 -- we cannot use a simple SLOC comparison to distinguish between
2063 -- the then/else statements, so we have to climb the tree.
2070 while Parent (N) /= CV loop
2073 -- If we fall off the top of the tree, then that's odd, but
2074 -- perhaps it could occur in some error situation, and the
2075 -- safest response is simply to assume that the outcome of
2076 -- the condition is unknown. No point in bombing during an
2077 -- attempt to optimize things.
2084 -- Now we have N pointing to a node whose parent is the IF
2085 -- statement in question, so now we can tell if we are within
2086 -- the THEN statements.
2088 if Is_List_Member (N)
2089 and then List_Containing (N) = Then_Statements (CV)
2093 -- If the variable reference does not come from source, we
2094 -- cannot reliably tell whether it appears in the else part.
2095 -- In particular, if if appears in generated code for a node
2096 -- that requires finalization, it may be attached to a list
2097 -- that has not been yet inserted into the code. For now,
2098 -- treat it as unknown.
2100 elsif not Comes_From_Source (N) then
2103 -- Otherwise we must be in ELSIF or ELSE part
2110 -- ELSIF part. Condition is known true within the referenced
2111 -- ELSIF, known False in any subsequent ELSIF or ELSE part, and
2112 -- unknown before the ELSE part or after the IF statement.
2114 elsif Nkind (CV) = N_Elsif_Part then
2117 -- Before start of ELSIF part
2119 if Loc < Sloc (CV) then
2122 -- After end of IF statement
2124 elsif Loc >= Sloc (Stm) +
2125 Text_Ptr (UI_To_Int (End_Span (Stm)))
2130 -- Again we lack the SLOC of the ELSE, so we need to climb the
2131 -- tree to see if we are within the ELSIF part in question.
2138 while Parent (N) /= Stm loop
2141 -- If we fall off the top of the tree, then that's odd, but
2142 -- perhaps it could occur in some error situation, and the
2143 -- safest response is simply to assume that the outcome of
2144 -- the condition is unknown. No point in bombing during an
2145 -- attempt to optimize things.
2152 -- Now we have N pointing to a node whose parent is the IF
2153 -- statement in question, so see if is the ELSIF part we want.
2154 -- the THEN statements.
2159 -- Otherwise we must be in subsequent ELSIF or ELSE part
2166 -- Iteration scheme of while loop. The condition is known to be
2167 -- true within the body of the loop.
2169 elsif Nkind (CV) = N_Iteration_Scheme then
2171 Loop_Stmt : constant Node_Id := Parent (CV);
2174 -- Before start of body of loop
2176 if Loc < Sloc (Loop_Stmt) then
2179 -- After end of LOOP statement
2181 elsif Loc >= Sloc (End_Label (Loop_Stmt)) then
2184 -- We are within the body of the loop
2191 -- All other cases of Current_Value settings
2197 -- If we fall through here, then we have a reportable condition, Sens
2198 -- is True if the condition is true and False if it needs inverting.
2200 Process_Current_Value_Condition (Condition (CV), Sens);
2202 end Get_Current_Value_Condition;
2204 ---------------------------------
2205 -- Has_Controlled_Coextensions --
2206 ---------------------------------
2208 function Has_Controlled_Coextensions (Typ : Entity_Id) return Boolean is
2213 -- Only consider record types
2215 if Ekind (Typ) /= E_Record_Type
2216 and then Ekind (Typ) /= E_Record_Subtype
2221 if Has_Discriminants (Typ) then
2222 Discr := First_Discriminant (Typ);
2223 while Present (Discr) loop
2224 D_Typ := Etype (Discr);
2226 if Ekind (D_Typ) = E_Anonymous_Access_Type
2228 (Is_Controlled (Directly_Designated_Type (D_Typ))
2230 Is_Concurrent_Type (Directly_Designated_Type (D_Typ)))
2235 Next_Discriminant (Discr);
2240 end Has_Controlled_Coextensions;
2242 --------------------
2243 -- Homonym_Number --
2244 --------------------
2246 function Homonym_Number (Subp : Entity_Id) return Nat is
2252 Hom := Homonym (Subp);
2253 while Present (Hom) loop
2254 if Scope (Hom) = Scope (Subp) then
2258 Hom := Homonym (Hom);
2264 ------------------------------
2265 -- In_Unconditional_Context --
2266 ------------------------------
2268 function In_Unconditional_Context (Node : Node_Id) return Boolean is
2273 while Present (P) loop
2275 when N_Subprogram_Body =>
2278 when N_If_Statement =>
2281 when N_Loop_Statement =>
2284 when N_Case_Statement =>
2293 end In_Unconditional_Context;
2299 procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is
2301 if Present (Ins_Action) then
2302 Insert_Actions (Assoc_Node, New_List (Ins_Action));
2306 -- Version with check(s) suppressed
2308 procedure Insert_Action
2309 (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id)
2312 Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress);
2315 --------------------
2316 -- Insert_Actions --
2317 --------------------
2319 procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is
2323 Wrapped_Node : Node_Id := Empty;
2326 if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
2330 -- Ignore insert of actions from inside default expression (or other
2331 -- similar "spec expression") in the special spec-expression analyze
2332 -- mode. Any insertions at this point have no relevance, since we are
2333 -- only doing the analyze to freeze the types of any static expressions.
2334 -- See section "Handling of Default Expressions" in the spec of package
2335 -- Sem for further details.
2337 if In_Spec_Expression then
2341 -- If the action derives from stuff inside a record, then the actions
2342 -- are attached to the current scope, to be inserted and analyzed on
2343 -- exit from the scope. The reason for this is that we may also
2344 -- be generating freeze actions at the same time, and they must
2345 -- eventually be elaborated in the correct order.
2347 if Is_Record_Type (Current_Scope)
2348 and then not Is_Frozen (Current_Scope)
2350 if No (Scope_Stack.Table
2351 (Scope_Stack.Last).Pending_Freeze_Actions)
2353 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
2358 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
2364 -- We now intend to climb up the tree to find the right point to
2365 -- insert the actions. We start at Assoc_Node, unless this node is
2366 -- a subexpression in which case we start with its parent. We do this
2367 -- for two reasons. First it speeds things up. Second, if Assoc_Node
2368 -- is itself one of the special nodes like N_And_Then, then we assume
2369 -- that an initial request to insert actions for such a node does not
2370 -- expect the actions to get deposited in the node for later handling
2371 -- when the node is expanded, since clearly the node is being dealt
2372 -- with by the caller. Note that in the subexpression case, N is
2373 -- always the child we came from.
2375 -- N_Raise_xxx_Error is an annoying special case, it is a statement
2376 -- if it has type Standard_Void_Type, and a subexpression otherwise.
2377 -- otherwise. Procedure attribute references are also statements.
2379 if Nkind (Assoc_Node) in N_Subexpr
2380 and then (Nkind (Assoc_Node) in N_Raise_xxx_Error
2381 or else Etype (Assoc_Node) /= Standard_Void_Type)
2382 and then (Nkind (Assoc_Node) /= N_Attribute_Reference
2384 not Is_Procedure_Attribute_Name
2385 (Attribute_Name (Assoc_Node)))
2387 P := Assoc_Node; -- ??? does not agree with above!
2388 N := Parent (Assoc_Node);
2390 -- Non-subexpression case. Note that N is initially Empty in this
2391 -- case (N is only guaranteed Non-Empty in the subexpr case).
2398 -- Capture root of the transient scope
2400 if Scope_Is_Transient then
2401 Wrapped_Node := Node_To_Be_Wrapped;
2405 pragma Assert (Present (P));
2409 -- Case of right operand of AND THEN or OR ELSE. Put the actions
2410 -- in the Actions field of the right operand. They will be moved
2411 -- out further when the AND THEN or OR ELSE operator is expanded.
2412 -- Nothing special needs to be done for the left operand since
2413 -- in that case the actions are executed unconditionally.
2415 when N_And_Then | N_Or_Else =>
2416 if N = Right_Opnd (P) then
2418 -- We are now going to either append the actions to the
2419 -- actions field of the short-circuit operation. We will
2420 -- also analyze the actions now.
2422 -- This analysis is really too early, the proper thing would
2423 -- be to just park them there now, and only analyze them if
2424 -- we find we really need them, and to it at the proper
2425 -- final insertion point. However attempting to this proved
2426 -- tricky, so for now we just kill current values before and
2427 -- after the analyze call to make sure we avoid peculiar
2428 -- optimizations from this out of order insertion.
2430 Kill_Current_Values;
2432 if Present (Actions (P)) then
2433 Insert_List_After_And_Analyze
2434 (Last (Actions (P)), Ins_Actions);
2436 Set_Actions (P, Ins_Actions);
2437 Analyze_List (Actions (P));
2440 Kill_Current_Values;
2445 -- Then or Else operand of conditional expression. Add actions to
2446 -- Then_Actions or Else_Actions field as appropriate. The actions
2447 -- will be moved further out when the conditional is expanded.
2449 when N_Conditional_Expression =>
2451 ThenX : constant Node_Id := Next (First (Expressions (P)));
2452 ElseX : constant Node_Id := Next (ThenX);
2455 -- Actions belong to the then expression, temporarily
2456 -- place them as Then_Actions of the conditional expr.
2457 -- They will be moved to the proper place later when
2458 -- the conditional expression is expanded.
2461 if Present (Then_Actions (P)) then
2462 Insert_List_After_And_Analyze
2463 (Last (Then_Actions (P)), Ins_Actions);
2465 Set_Then_Actions (P, Ins_Actions);
2466 Analyze_List (Then_Actions (P));
2471 -- Actions belong to the else expression, temporarily
2472 -- place them as Else_Actions of the conditional expr.
2473 -- They will be moved to the proper place later when
2474 -- the conditional expression is expanded.
2476 elsif N = ElseX then
2477 if Present (Else_Actions (P)) then
2478 Insert_List_After_And_Analyze
2479 (Last (Else_Actions (P)), Ins_Actions);
2481 Set_Else_Actions (P, Ins_Actions);
2482 Analyze_List (Else_Actions (P));
2487 -- Actions belong to the condition. In this case they are
2488 -- unconditionally executed, and so we can continue the
2489 -- search for the proper insert point.
2496 -- Case of appearing in the condition of a while expression or
2497 -- elsif. We insert the actions into the Condition_Actions field.
2498 -- They will be moved further out when the while loop or elsif
2501 when N_Iteration_Scheme |
2504 if N = Condition (P) then
2505 if Present (Condition_Actions (P)) then
2506 Insert_List_After_And_Analyze
2507 (Last (Condition_Actions (P)), Ins_Actions);
2509 Set_Condition_Actions (P, Ins_Actions);
2511 -- Set the parent of the insert actions explicitly.
2512 -- This is not a syntactic field, but we need the
2513 -- parent field set, in particular so that freeze
2514 -- can understand that it is dealing with condition
2515 -- actions, and properly insert the freezing actions.
2517 Set_Parent (Ins_Actions, P);
2518 Analyze_List (Condition_Actions (P));
2524 -- Statements, declarations, pragmas, representation clauses
2529 N_Procedure_Call_Statement |
2530 N_Statement_Other_Than_Procedure_Call |
2536 -- Representation_Clause
2539 N_Attribute_Definition_Clause |
2540 N_Enumeration_Representation_Clause |
2541 N_Record_Representation_Clause |
2545 N_Abstract_Subprogram_Declaration |
2547 N_Exception_Declaration |
2548 N_Exception_Renaming_Declaration |
2549 N_Formal_Abstract_Subprogram_Declaration |
2550 N_Formal_Concrete_Subprogram_Declaration |
2551 N_Formal_Object_Declaration |
2552 N_Formal_Type_Declaration |
2553 N_Full_Type_Declaration |
2554 N_Function_Instantiation |
2555 N_Generic_Function_Renaming_Declaration |
2556 N_Generic_Package_Declaration |
2557 N_Generic_Package_Renaming_Declaration |
2558 N_Generic_Procedure_Renaming_Declaration |
2559 N_Generic_Subprogram_Declaration |
2560 N_Implicit_Label_Declaration |
2561 N_Incomplete_Type_Declaration |
2562 N_Number_Declaration |
2563 N_Object_Declaration |
2564 N_Object_Renaming_Declaration |
2566 N_Package_Body_Stub |
2567 N_Package_Declaration |
2568 N_Package_Instantiation |
2569 N_Package_Renaming_Declaration |
2570 N_Private_Extension_Declaration |
2571 N_Private_Type_Declaration |
2572 N_Procedure_Instantiation |
2574 N_Protected_Body_Stub |
2575 N_Protected_Type_Declaration |
2576 N_Single_Task_Declaration |
2578 N_Subprogram_Body_Stub |
2579 N_Subprogram_Declaration |
2580 N_Subprogram_Renaming_Declaration |
2581 N_Subtype_Declaration |
2584 N_Task_Type_Declaration |
2586 -- Freeze entity behaves like a declaration or statement
2590 -- Do not insert here if the item is not a list member (this
2591 -- happens for example with a triggering statement, and the
2592 -- proper approach is to insert before the entire select).
2594 if not Is_List_Member (P) then
2597 -- Do not insert if parent of P is an N_Component_Association
2598 -- node (i.e. we are in the context of an N_Aggregate or
2599 -- N_Extension_Aggregate node. In this case we want to insert
2600 -- before the entire aggregate.
2602 elsif Nkind (Parent (P)) = N_Component_Association then
2605 -- Do not insert if the parent of P is either an N_Variant
2606 -- node or an N_Record_Definition node, meaning in either
2607 -- case that P is a member of a component list, and that
2608 -- therefore the actions should be inserted outside the
2609 -- complete record declaration.
2611 elsif Nkind (Parent (P)) = N_Variant
2612 or else Nkind (Parent (P)) = N_Record_Definition
2616 -- Do not insert freeze nodes within the loop generated for
2617 -- an aggregate, because they may be elaborated too late for
2618 -- subsequent use in the back end: within a package spec the
2619 -- loop is part of the elaboration procedure and is only
2620 -- elaborated during the second pass.
2621 -- If the loop comes from source, or the entity is local to
2622 -- the loop itself it must remain within.
2624 elsif Nkind (Parent (P)) = N_Loop_Statement
2625 and then not Comes_From_Source (Parent (P))
2626 and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
2628 Scope (Entity (First (Ins_Actions))) /= Current_Scope
2632 -- Otherwise we can go ahead and do the insertion
2634 elsif P = Wrapped_Node then
2635 Store_Before_Actions_In_Scope (Ins_Actions);
2639 Insert_List_Before_And_Analyze (P, Ins_Actions);
2643 -- A special case, N_Raise_xxx_Error can act either as a
2644 -- statement or a subexpression. We tell the difference
2645 -- by looking at the Etype. It is set to Standard_Void_Type
2646 -- in the statement case.
2649 N_Raise_xxx_Error =>
2650 if Etype (P) = Standard_Void_Type then
2651 if P = Wrapped_Node then
2652 Store_Before_Actions_In_Scope (Ins_Actions);
2654 Insert_List_Before_And_Analyze (P, Ins_Actions);
2659 -- In the subexpression case, keep climbing
2665 -- If a component association appears within a loop created for
2666 -- an array aggregate, attach the actions to the association so
2667 -- they can be subsequently inserted within the loop. For other
2668 -- component associations insert outside of the aggregate. For
2669 -- an association that will generate a loop, its Loop_Actions
2670 -- attribute is already initialized (see exp_aggr.adb).
2672 -- The list of loop_actions can in turn generate additional ones,
2673 -- that are inserted before the associated node. If the associated
2674 -- node is outside the aggregate, the new actions are collected
2675 -- at the end of the loop actions, to respect the order in which
2676 -- they are to be elaborated.
2679 N_Component_Association =>
2680 if Nkind (Parent (P)) = N_Aggregate
2681 and then Present (Loop_Actions (P))
2683 if Is_Empty_List (Loop_Actions (P)) then
2684 Set_Loop_Actions (P, Ins_Actions);
2685 Analyze_List (Ins_Actions);
2692 -- Check whether these actions were generated
2693 -- by a declaration that is part of the loop_
2694 -- actions for the component_association.
2697 while Present (Decl) loop
2698 exit when Parent (Decl) = P
2699 and then Is_List_Member (Decl)
2701 List_Containing (Decl) = Loop_Actions (P);
2702 Decl := Parent (Decl);
2705 if Present (Decl) then
2706 Insert_List_Before_And_Analyze
2707 (Decl, Ins_Actions);
2709 Insert_List_After_And_Analyze
2710 (Last (Loop_Actions (P)), Ins_Actions);
2721 -- Another special case, an attribute denoting a procedure call
2724 N_Attribute_Reference =>
2725 if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
2726 if P = Wrapped_Node then
2727 Store_Before_Actions_In_Scope (Ins_Actions);
2729 Insert_List_Before_And_Analyze (P, Ins_Actions);
2734 -- In the subexpression case, keep climbing
2740 -- For all other node types, keep climbing tree
2744 N_Accept_Alternative |
2745 N_Access_Definition |
2746 N_Access_Function_Definition |
2747 N_Access_Procedure_Definition |
2748 N_Access_To_Object_Definition |
2751 N_Case_Statement_Alternative |
2752 N_Character_Literal |
2753 N_Compilation_Unit |
2754 N_Compilation_Unit_Aux |
2755 N_Component_Clause |
2756 N_Component_Declaration |
2757 N_Component_Definition |
2759 N_Constrained_Array_Definition |
2760 N_Decimal_Fixed_Point_Definition |
2761 N_Defining_Character_Literal |
2762 N_Defining_Identifier |
2763 N_Defining_Operator_Symbol |
2764 N_Defining_Program_Unit_Name |
2765 N_Delay_Alternative |
2766 N_Delta_Constraint |
2767 N_Derived_Type_Definition |
2769 N_Digits_Constraint |
2770 N_Discriminant_Association |
2771 N_Discriminant_Specification |
2773 N_Entry_Body_Formal_Part |
2774 N_Entry_Call_Alternative |
2775 N_Entry_Declaration |
2776 N_Entry_Index_Specification |
2777 N_Enumeration_Type_Definition |
2779 N_Exception_Handler |
2781 N_Explicit_Dereference |
2782 N_Extension_Aggregate |
2783 N_Floating_Point_Definition |
2784 N_Formal_Decimal_Fixed_Point_Definition |
2785 N_Formal_Derived_Type_Definition |
2786 N_Formal_Discrete_Type_Definition |
2787 N_Formal_Floating_Point_Definition |
2788 N_Formal_Modular_Type_Definition |
2789 N_Formal_Ordinary_Fixed_Point_Definition |
2790 N_Formal_Package_Declaration |
2791 N_Formal_Private_Type_Definition |
2792 N_Formal_Signed_Integer_Type_Definition |
2794 N_Function_Specification |
2795 N_Generic_Association |
2796 N_Handled_Sequence_Of_Statements |
2799 N_Index_Or_Discriminant_Constraint |
2800 N_Indexed_Component |
2804 N_Loop_Parameter_Specification |
2806 N_Modular_Type_Definition |
2832 N_Op_Shift_Right_Arithmetic |
2836 N_Ordinary_Fixed_Point_Definition |
2838 N_Package_Specification |
2839 N_Parameter_Association |
2840 N_Parameter_Specification |
2841 N_Pop_Constraint_Error_Label |
2842 N_Pop_Program_Error_Label |
2843 N_Pop_Storage_Error_Label |
2844 N_Pragma_Argument_Association |
2845 N_Procedure_Specification |
2846 N_Protected_Definition |
2847 N_Push_Constraint_Error_Label |
2848 N_Push_Program_Error_Label |
2849 N_Push_Storage_Error_Label |
2850 N_Qualified_Expression |
2852 N_Range_Constraint |
2854 N_Real_Range_Specification |
2855 N_Record_Definition |
2857 N_Selected_Component |
2858 N_Signed_Integer_Type_Definition |
2859 N_Single_Protected_Declaration |
2863 N_Subtype_Indication |
2866 N_Terminate_Alternative |
2867 N_Triggering_Alternative |
2869 N_Unchecked_Expression |
2870 N_Unchecked_Type_Conversion |
2871 N_Unconstrained_Array_Definition |
2874 N_Use_Package_Clause |
2878 N_Validate_Unchecked_Conversion |
2885 -- Make sure that inserted actions stay in the transient scope
2887 if P = Wrapped_Node then
2888 Store_Before_Actions_In_Scope (Ins_Actions);
2892 -- If we fall through above tests, keep climbing tree
2896 if Nkind (Parent (N)) = N_Subunit then
2898 -- This is the proper body corresponding to a stub. Insertion
2899 -- must be done at the point of the stub, which is in the decla-
2900 -- rative part of the parent unit.
2902 P := Corresponding_Stub (Parent (N));
2910 -- Version with check(s) suppressed
2912 procedure Insert_Actions
2913 (Assoc_Node : Node_Id;
2914 Ins_Actions : List_Id;
2915 Suppress : Check_Id)
2918 if Suppress = All_Checks then
2920 Svg : constant Suppress_Array := Scope_Suppress;
2922 Scope_Suppress := (others => True);
2923 Insert_Actions (Assoc_Node, Ins_Actions);
2924 Scope_Suppress := Svg;
2929 Svg : constant Boolean := Scope_Suppress (Suppress);
2931 Scope_Suppress (Suppress) := True;
2932 Insert_Actions (Assoc_Node, Ins_Actions);
2933 Scope_Suppress (Suppress) := Svg;
2938 --------------------------
2939 -- Insert_Actions_After --
2940 --------------------------
2942 procedure Insert_Actions_After
2943 (Assoc_Node : Node_Id;
2944 Ins_Actions : List_Id)
2947 if Scope_Is_Transient
2948 and then Assoc_Node = Node_To_Be_Wrapped
2950 Store_After_Actions_In_Scope (Ins_Actions);
2952 Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
2954 end Insert_Actions_After;
2956 ---------------------------------
2957 -- Insert_Library_Level_Action --
2958 ---------------------------------
2960 procedure Insert_Library_Level_Action (N : Node_Id) is
2961 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2964 Push_Scope (Cunit_Entity (Main_Unit));
2965 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2967 if No (Actions (Aux)) then
2968 Set_Actions (Aux, New_List (N));
2970 Append (N, Actions (Aux));
2975 end Insert_Library_Level_Action;
2977 ----------------------------------
2978 -- Insert_Library_Level_Actions --
2979 ----------------------------------
2981 procedure Insert_Library_Level_Actions (L : List_Id) is
2982 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2985 if Is_Non_Empty_List (L) then
2986 Push_Scope (Cunit_Entity (Main_Unit));
2987 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2989 if No (Actions (Aux)) then
2990 Set_Actions (Aux, L);
2993 Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
2998 end Insert_Library_Level_Actions;
3000 ----------------------
3001 -- Inside_Init_Proc --
3002 ----------------------
3004 function Inside_Init_Proc return Boolean is
3010 and then S /= Standard_Standard
3012 if Is_Init_Proc (S) then
3020 end Inside_Init_Proc;
3022 ----------------------------
3023 -- Is_All_Null_Statements --
3024 ----------------------------
3026 function Is_All_Null_Statements (L : List_Id) return Boolean is
3031 while Present (Stm) loop
3032 if Nkind (Stm) /= N_Null_Statement then
3040 end Is_All_Null_Statements;
3042 ----------------------------------
3043 -- Is_Library_Level_Tagged_Type --
3044 ----------------------------------
3046 function Is_Library_Level_Tagged_Type (Typ : Entity_Id) return Boolean is
3048 return Is_Tagged_Type (Typ)
3049 and then Is_Library_Level_Entity (Typ);
3050 end Is_Library_Level_Tagged_Type;
3052 -----------------------------------------
3053 -- Is_Predefined_Dispatching_Operation --
3054 -----------------------------------------
3056 function Is_Predefined_Dispatching_Operation (E : Entity_Id) return Boolean
3058 TSS_Name : TSS_Name_Type;
3061 if not Is_Dispatching_Operation (E) then
3065 Get_Name_String (Chars (E));
3067 -- Most predefined primitives have internally generated names. Equality
3068 -- must be treated differently; the predefined operation is recognized
3069 -- as a homogeneous binary operator that returns Boolean.
3071 if Name_Len > TSS_Name_Type'Last then
3072 TSS_Name := TSS_Name_Type (Name_Buffer (Name_Len - TSS_Name'Length + 1
3074 if Chars (E) = Name_uSize
3075 or else Chars (E) = Name_uAlignment
3076 or else TSS_Name = TSS_Stream_Read
3077 or else TSS_Name = TSS_Stream_Write
3078 or else TSS_Name = TSS_Stream_Input
3079 or else TSS_Name = TSS_Stream_Output
3081 (Chars (E) = Name_Op_Eq
3082 and then Etype (First_Entity (E)) = Etype (Last_Entity (E)))
3083 or else Chars (E) = Name_uAssign
3084 or else TSS_Name = TSS_Deep_Adjust
3085 or else TSS_Name = TSS_Deep_Finalize
3086 or else (Ada_Version >= Ada_05
3087 and then (Chars (E) = Name_uDisp_Asynchronous_Select
3088 or else Chars (E) = Name_uDisp_Conditional_Select
3089 or else Chars (E) = Name_uDisp_Get_Prim_Op_Kind
3090 or else Chars (E) = Name_uDisp_Get_Task_Id
3091 or else Chars (E) = Name_uDisp_Requeue
3092 or else Chars (E) = Name_uDisp_Timed_Select))
3099 end Is_Predefined_Dispatching_Operation;
3101 ----------------------------------
3102 -- Is_Possibly_Unaligned_Object --
3103 ----------------------------------
3105 function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is
3106 T : constant Entity_Id := Etype (N);
3109 -- If renamed object, apply test to underlying object
3111 if Is_Entity_Name (N)
3112 and then Is_Object (Entity (N))
3113 and then Present (Renamed_Object (Entity (N)))
3115 return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N)));
3118 -- Tagged and controlled types and aliased types are always aligned,
3119 -- as are concurrent types.
3122 or else Has_Controlled_Component (T)
3123 or else Is_Concurrent_Type (T)
3124 or else Is_Tagged_Type (T)
3125 or else Is_Controlled (T)
3130 -- If this is an element of a packed array, may be unaligned
3132 if Is_Ref_To_Bit_Packed_Array (N) then
3136 -- Case of component reference
3138 if Nkind (N) = N_Selected_Component then
3140 P : constant Node_Id := Prefix (N);
3141 C : constant Entity_Id := Entity (Selector_Name (N));
3146 -- If component reference is for an array with non-static bounds,
3147 -- then it is always aligned: we can only process unaligned
3148 -- arrays with static bounds (more accurately bounds known at
3151 if Is_Array_Type (T)
3152 and then not Compile_Time_Known_Bounds (T)
3157 -- If component is aliased, it is definitely properly aligned
3159 if Is_Aliased (C) then
3163 -- If component is for a type implemented as a scalar, and the
3164 -- record is packed, and the component is other than the first
3165 -- component of the record, then the component may be unaligned.
3167 if Is_Packed (Etype (P))
3168 and then Represented_As_Scalar (Etype (C))
3169 and then First_Entity (Scope (C)) /= C
3174 -- Compute maximum possible alignment for T
3176 -- If alignment is known, then that settles things
3178 if Known_Alignment (T) then
3179 M := UI_To_Int (Alignment (T));
3181 -- If alignment is not known, tentatively set max alignment
3184 M := Ttypes.Maximum_Alignment;
3186 -- We can reduce this if the Esize is known since the default
3187 -- alignment will never be more than the smallest power of 2
3188 -- that does not exceed this Esize value.
3190 if Known_Esize (T) then
3191 S := UI_To_Int (Esize (T));
3193 while (M / 2) >= S loop
3199 -- If the component reference is for a record that has a specified
3200 -- alignment, and we either know it is too small, or cannot tell,
3201 -- then the component may be unaligned
3203 if Known_Alignment (Etype (P))
3204 and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment
3205 and then M > Alignment (Etype (P))
3210 -- Case of component clause present which may specify an
3211 -- unaligned position.
3213 if Present (Component_Clause (C)) then
3215 -- Otherwise we can do a test to make sure that the actual
3216 -- start position in the record, and the length, are both
3217 -- consistent with the required alignment. If not, we know
3218 -- that we are unaligned.
3221 Align_In_Bits : constant Nat := M * System_Storage_Unit;
3223 if Component_Bit_Offset (C) mod Align_In_Bits /= 0
3224 or else Esize (C) mod Align_In_Bits /= 0
3231 -- Otherwise, for a component reference, test prefix
3233 return Is_Possibly_Unaligned_Object (P);
3236 -- If not a component reference, must be aligned
3241 end Is_Possibly_Unaligned_Object;
3243 ---------------------------------
3244 -- Is_Possibly_Unaligned_Slice --
3245 ---------------------------------
3247 function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is
3249 -- Go to renamed object
3251 if Is_Entity_Name (N)
3252 and then Is_Object (Entity (N))
3253 and then Present (Renamed_Object (Entity (N)))
3255 return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N)));
3258 -- The reference must be a slice
3260 if Nkind (N) /= N_Slice then
3264 -- Always assume the worst for a nested record component with a
3265 -- component clause, which gigi/gcc does not appear to handle well.
3266 -- It is not clear why this special test is needed at all ???
3268 if Nkind (Prefix (N)) = N_Selected_Component
3269 and then Nkind (Prefix (Prefix (N))) = N_Selected_Component
3271 Present (Component_Clause (Entity (Selector_Name (Prefix (N)))))
3276 -- We only need to worry if the target has strict alignment
3278 if not Target_Strict_Alignment then
3282 -- If it is a slice, then look at the array type being sliced
3285 Sarr : constant Node_Id := Prefix (N);
3286 -- Prefix of the slice, i.e. the array being sliced
3288 Styp : constant Entity_Id := Etype (Prefix (N));
3289 -- Type of the array being sliced
3295 -- The problems arise if the array object that is being sliced
3296 -- is a component of a record or array, and we cannot guarantee
3297 -- the alignment of the array within its containing object.
3299 -- To investigate this, we look at successive prefixes to see
3300 -- if we have a worrisome indexed or selected component.
3304 -- Case of array is part of an indexed component reference
3306 if Nkind (Pref) = N_Indexed_Component then
3307 Ptyp := Etype (Prefix (Pref));
3309 -- The only problematic case is when the array is packed,
3310 -- in which case we really know nothing about the alignment
3311 -- of individual components.
3313 if Is_Bit_Packed_Array (Ptyp) then
3317 -- Case of array is part of a selected component reference
3319 elsif Nkind (Pref) = N_Selected_Component then
3320 Ptyp := Etype (Prefix (Pref));
3322 -- We are definitely in trouble if the record in question
3323 -- has an alignment, and either we know this alignment is
3324 -- inconsistent with the alignment of the slice, or we
3325 -- don't know what the alignment of the slice should be.
3327 if Known_Alignment (Ptyp)
3328 and then (Unknown_Alignment (Styp)
3329 or else Alignment (Styp) > Alignment (Ptyp))
3334 -- We are in potential trouble if the record type is packed.
3335 -- We could special case when we know that the array is the
3336 -- first component, but that's not such a simple case ???
3338 if Is_Packed (Ptyp) then
3342 -- We are in trouble if there is a component clause, and
3343 -- either we do not know the alignment of the slice, or
3344 -- the alignment of the slice is inconsistent with the
3345 -- bit position specified by the component clause.
3348 Field : constant Entity_Id := Entity (Selector_Name (Pref));
3350 if Present (Component_Clause (Field))
3352 (Unknown_Alignment (Styp)
3354 (Component_Bit_Offset (Field) mod
3355 (System_Storage_Unit * Alignment (Styp))) /= 0)
3361 -- For cases other than selected or indexed components we
3362 -- know we are OK, since no issues arise over alignment.
3368 -- We processed an indexed component or selected component
3369 -- reference that looked safe, so keep checking prefixes.
3371 Pref := Prefix (Pref);
3374 end Is_Possibly_Unaligned_Slice;
3376 --------------------------------
3377 -- Is_Ref_To_Bit_Packed_Array --
3378 --------------------------------
3380 function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is
3385 if Is_Entity_Name (N)
3386 and then Is_Object (Entity (N))
3387 and then Present (Renamed_Object (Entity (N)))
3389 return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N)));
3392 if Nkind (N) = N_Indexed_Component
3394 Nkind (N) = N_Selected_Component
3396 if Is_Bit_Packed_Array (Etype (Prefix (N))) then
3399 Result := Is_Ref_To_Bit_Packed_Array (Prefix (N));
3402 if Result and then Nkind (N) = N_Indexed_Component then
3403 Expr := First (Expressions (N));
3404 while Present (Expr) loop
3405 Force_Evaluation (Expr);
3415 end Is_Ref_To_Bit_Packed_Array;
3417 --------------------------------
3418 -- Is_Ref_To_Bit_Packed_Slice --
3419 --------------------------------
3421 function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is
3423 if Nkind (N) = N_Type_Conversion then
3424 return Is_Ref_To_Bit_Packed_Slice (Expression (N));
3426 elsif Is_Entity_Name (N)
3427 and then Is_Object (Entity (N))
3428 and then Present (Renamed_Object (Entity (N)))
3430 return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N)));
3432 elsif Nkind (N) = N_Slice
3433 and then Is_Bit_Packed_Array (Etype (Prefix (N)))
3437 elsif Nkind (N) = N_Indexed_Component
3439 Nkind (N) = N_Selected_Component
3441 return Is_Ref_To_Bit_Packed_Slice (Prefix (N));
3446 end Is_Ref_To_Bit_Packed_Slice;
3448 -----------------------
3449 -- Is_Renamed_Object --
3450 -----------------------
3452 function Is_Renamed_Object (N : Node_Id) return Boolean is
3453 Pnod : constant Node_Id := Parent (N);
3454 Kind : constant Node_Kind := Nkind (Pnod);
3457 if Kind = N_Object_Renaming_Declaration then
3460 elsif Kind = N_Indexed_Component
3461 or else Kind = N_Selected_Component
3463 return Is_Renamed_Object (Pnod);
3468 end Is_Renamed_Object;
3470 ----------------------------
3471 -- Is_Untagged_Derivation --
3472 ----------------------------
3474 function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
3476 return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
3478 (Is_Private_Type (T) and then Present (Full_View (T))
3479 and then not Is_Tagged_Type (Full_View (T))
3480 and then Is_Derived_Type (Full_View (T))
3481 and then Etype (Full_View (T)) /= T);
3482 end Is_Untagged_Derivation;
3484 ---------------------------
3485 -- Is_Volatile_Reference --
3486 ---------------------------
3488 function Is_Volatile_Reference (N : Node_Id) return Boolean is
3490 if Nkind (N) in N_Has_Etype
3491 and then Present (Etype (N))
3492 and then Treat_As_Volatile (Etype (N))
3496 elsif Is_Entity_Name (N) then
3497 return Treat_As_Volatile (Entity (N));
3499 elsif Nkind (N) = N_Slice then
3500 return Is_Volatile_Reference (Prefix (N));
3502 elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then
3503 if (Is_Entity_Name (Prefix (N))
3504 and then Has_Volatile_Components (Entity (Prefix (N))))
3505 or else (Present (Etype (Prefix (N)))
3506 and then Has_Volatile_Components (Etype (Prefix (N))))
3510 return Is_Volatile_Reference (Prefix (N));
3516 end Is_Volatile_Reference;
3518 --------------------
3519 -- Kill_Dead_Code --
3520 --------------------
3522 procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is
3525 Remove_Warning_Messages (N);
3529 ("?this code can never be executed and has been deleted!", N);
3532 -- Recurse into block statements and bodies to process declarations
3535 if Nkind (N) = N_Block_Statement
3536 or else Nkind (N) = N_Subprogram_Body
3537 or else Nkind (N) = N_Package_Body
3539 Kill_Dead_Code (Declarations (N), False);
3540 Kill_Dead_Code (Statements (Handled_Statement_Sequence (N)));
3542 if Nkind (N) = N_Subprogram_Body then
3543 Set_Is_Eliminated (Defining_Entity (N));
3546 elsif Nkind (N) = N_Package_Declaration then
3547 Kill_Dead_Code (Visible_Declarations (Specification (N)));
3548 Kill_Dead_Code (Private_Declarations (Specification (N)));
3550 -- ??? After this point, Delete_Tree has been called on all
3551 -- declarations in Specification (N), so references to
3552 -- entities therein look suspicious.
3555 E : Entity_Id := First_Entity (Defining_Entity (N));
3557 while Present (E) loop
3558 if Ekind (E) = E_Operator then
3559 Set_Is_Eliminated (E);
3566 -- Recurse into composite statement to kill individual statements,
3567 -- in particular instantiations.
3569 elsif Nkind (N) = N_If_Statement then
3570 Kill_Dead_Code (Then_Statements (N));
3571 Kill_Dead_Code (Elsif_Parts (N));
3572 Kill_Dead_Code (Else_Statements (N));
3574 elsif Nkind (N) = N_Loop_Statement then
3575 Kill_Dead_Code (Statements (N));
3577 elsif Nkind (N) = N_Case_Statement then
3581 Alt := First (Alternatives (N));
3582 while Present (Alt) loop
3583 Kill_Dead_Code (Statements (Alt));
3588 elsif Nkind (N) = N_Case_Statement_Alternative then
3589 Kill_Dead_Code (Statements (N));
3591 -- Deal with dead instances caused by deleting instantiations
3593 elsif Nkind (N) in N_Generic_Instantiation then
3594 Remove_Dead_Instance (N);
3599 -- Case where argument is a list of nodes to be killed
3601 procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is
3606 if Is_Non_Empty_List (L) then
3608 while Present (N) loop
3609 Kill_Dead_Code (N, W);
3616 ------------------------
3617 -- Known_Non_Negative --
3618 ------------------------
3620 function Known_Non_Negative (Opnd : Node_Id) return Boolean is
3622 if Is_OK_Static_Expression (Opnd)
3623 and then Expr_Value (Opnd) >= 0
3629 Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd));
3633 Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0;
3636 end Known_Non_Negative;
3638 --------------------
3639 -- Known_Non_Null --
3640 --------------------
3642 function Known_Non_Null (N : Node_Id) return Boolean is
3644 -- Checks for case where N is an entity reference
3646 if Is_Entity_Name (N) and then Present (Entity (N)) then
3648 E : constant Entity_Id := Entity (N);
3653 -- First check if we are in decisive conditional
3655 Get_Current_Value_Condition (N, Op, Val);
3657 if Known_Null (Val) then
3658 if Op = N_Op_Eq then
3660 elsif Op = N_Op_Ne then
3665 -- If OK to do replacement, test Is_Known_Non_Null flag
3667 if OK_To_Do_Constant_Replacement (E) then
3668 return Is_Known_Non_Null (E);
3670 -- Otherwise if not safe to do replacement, then say so
3677 -- True if access attribute
3679 elsif Nkind (N) = N_Attribute_Reference
3680 and then (Attribute_Name (N) = Name_Access
3682 Attribute_Name (N) = Name_Unchecked_Access
3684 Attribute_Name (N) = Name_Unrestricted_Access)
3688 -- True if allocator
3690 elsif Nkind (N) = N_Allocator then
3693 -- For a conversion, true if expression is known non-null
3695 elsif Nkind (N) = N_Type_Conversion then
3696 return Known_Non_Null (Expression (N));
3698 -- Above are all cases where the value could be determined to be
3699 -- non-null. In all other cases, we don't know, so return False.
3710 function Known_Null (N : Node_Id) return Boolean is
3712 -- Checks for case where N is an entity reference
3714 if Is_Entity_Name (N) and then Present (Entity (N)) then
3716 E : constant Entity_Id := Entity (N);
3721 -- Constant null value is for sure null
3723 if Ekind (E) = E_Constant
3724 and then Known_Null (Constant_Value (E))
3729 -- First check if we are in decisive conditional
3731 Get_Current_Value_Condition (N, Op, Val);
3733 if Known_Null (Val) then
3734 if Op = N_Op_Eq then
3736 elsif Op = N_Op_Ne then
3741 -- If OK to do replacement, test Is_Known_Null flag
3743 if OK_To_Do_Constant_Replacement (E) then
3744 return Is_Known_Null (E);
3746 -- Otherwise if not safe to do replacement, then say so
3753 -- True if explicit reference to null
3755 elsif Nkind (N) = N_Null then
3758 -- For a conversion, true if expression is known null
3760 elsif Nkind (N) = N_Type_Conversion then
3761 return Known_Null (Expression (N));
3763 -- Above are all cases where the value could be determined to be null.
3764 -- In all other cases, we don't know, so return False.
3771 -----------------------------
3772 -- Make_CW_Equivalent_Type --
3773 -----------------------------
3775 -- Create a record type used as an equivalent of any member
3776 -- of the class which takes its size from exp.
3778 -- Generate the following code:
3780 -- type Equiv_T is record
3781 -- _parent : T (List of discriminant constraints taken from Exp);
3782 -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
3785 -- ??? Note that this type does not guarantee same alignment as all
3788 function Make_CW_Equivalent_Type
3790 E : Node_Id) return Entity_Id
3792 Loc : constant Source_Ptr := Sloc (E);
3793 Root_Typ : constant Entity_Id := Root_Type (T);
3794 List_Def : constant List_Id := Empty_List;
3795 Comp_List : constant List_Id := New_List;
3796 Equiv_Type : Entity_Id;
3797 Range_Type : Entity_Id;
3798 Str_Type : Entity_Id;
3799 Constr_Root : Entity_Id;
3803 if not Has_Discriminants (Root_Typ) then
3804 Constr_Root := Root_Typ;
3807 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
3809 -- subtype cstr__n is T (List of discr constraints taken from Exp)
3811 Append_To (List_Def,
3812 Make_Subtype_Declaration (Loc,
3813 Defining_Identifier => Constr_Root,
3814 Subtype_Indication =>
3815 Make_Subtype_From_Expr (E, Root_Typ)));
3818 -- Generate the range subtype declaration
3820 Range_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('G'));
3822 if not Is_Interface (Root_Typ) then
3823 -- subtype rg__xx is
3824 -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit
3827 Make_Op_Subtract (Loc,
3829 Make_Attribute_Reference (Loc,
3831 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3832 Attribute_Name => Name_Size),
3834 Make_Attribute_Reference (Loc,
3835 Prefix => New_Reference_To (Constr_Root, Loc),
3836 Attribute_Name => Name_Object_Size));
3838 -- subtype rg__xx is
3839 -- Storage_Offset range 1 .. Expr'size / Storage_Unit
3842 Make_Attribute_Reference (Loc,
3844 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3845 Attribute_Name => Name_Size);
3848 Set_Paren_Count (Sizexpr, 1);
3850 Append_To (List_Def,
3851 Make_Subtype_Declaration (Loc,
3852 Defining_Identifier => Range_Type,
3853 Subtype_Indication =>
3854 Make_Subtype_Indication (Loc,
3855 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc),
3856 Constraint => Make_Range_Constraint (Loc,
3859 Low_Bound => Make_Integer_Literal (Loc, 1),
3861 Make_Op_Divide (Loc,
3862 Left_Opnd => Sizexpr,
3863 Right_Opnd => Make_Integer_Literal (Loc,
3864 Intval => System_Storage_Unit)))))));
3866 -- subtype str__nn is Storage_Array (rg__x);
3868 Str_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
3869 Append_To (List_Def,
3870 Make_Subtype_Declaration (Loc,
3871 Defining_Identifier => Str_Type,
3872 Subtype_Indication =>
3873 Make_Subtype_Indication (Loc,
3874 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc),
3876 Make_Index_Or_Discriminant_Constraint (Loc,
3878 New_List (New_Reference_To (Range_Type, Loc))))));
3880 -- type Equiv_T is record
3881 -- [ _parent : Tnn; ]
3885 Equiv_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
3887 -- When the target requires front-end layout, it's necessary to allow
3888 -- the equivalent type to be frozen so that layout can occur (when the
3889 -- associated class-wide subtype is frozen, the equivalent type will
3890 -- be frozen, see freeze.adb). For other targets, Gigi wants to have
3891 -- the equivalent type marked as frozen and deals with this type itself.
3892 -- In the Gigi case this will also avoid the generation of an init
3893 -- procedure for the type.
3895 if not Frontend_Layout_On_Target then
3896 Set_Is_Frozen (Equiv_Type);
3899 Set_Ekind (Equiv_Type, E_Record_Type);
3900 Set_Parent_Subtype (Equiv_Type, Constr_Root);
3902 if not Is_Interface (Root_Typ) then
3903 Append_To (Comp_List,
3904 Make_Component_Declaration (Loc,
3905 Defining_Identifier =>
3906 Make_Defining_Identifier (Loc, Name_uParent),
3907 Component_Definition =>
3908 Make_Component_Definition (Loc,
3909 Aliased_Present => False,
3910 Subtype_Indication => New_Reference_To (Constr_Root, Loc))));
3913 Append_To (Comp_List,
3914 Make_Component_Declaration (Loc,
3915 Defining_Identifier =>
3916 Make_Defining_Identifier (Loc,
3917 Chars => New_Internal_Name ('C')),
3918 Component_Definition =>
3919 Make_Component_Definition (Loc,
3920 Aliased_Present => False,
3921 Subtype_Indication => New_Reference_To (Str_Type, Loc))));
3923 Append_To (List_Def,
3924 Make_Full_Type_Declaration (Loc,
3925 Defining_Identifier => Equiv_Type,
3927 Make_Record_Definition (Loc,
3929 Make_Component_List (Loc,
3930 Component_Items => Comp_List,
3931 Variant_Part => Empty))));
3933 -- Suppress all checks during the analysis of the expanded code
3934 -- to avoid the generation of spurious warnings under ZFP run-time.
3936 Insert_Actions (E, List_Def, Suppress => All_Checks);
3938 end Make_CW_Equivalent_Type;
3940 ------------------------
3941 -- Make_Literal_Range --
3942 ------------------------
3944 function Make_Literal_Range
3946 Literal_Typ : Entity_Id) return Node_Id
3948 Lo : constant Node_Id :=
3949 New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
3950 Index : constant Entity_Id := Etype (Lo);
3953 Length_Expr : constant Node_Id :=
3954 Make_Op_Subtract (Loc,
3956 Make_Integer_Literal (Loc,
3957 Intval => String_Literal_Length (Literal_Typ)),
3959 Make_Integer_Literal (Loc, 1));
3962 Set_Analyzed (Lo, False);
3964 if Is_Integer_Type (Index) then
3967 Left_Opnd => New_Copy_Tree (Lo),
3968 Right_Opnd => Length_Expr);
3971 Make_Attribute_Reference (Loc,
3972 Attribute_Name => Name_Val,
3973 Prefix => New_Occurrence_Of (Index, Loc),
3974 Expressions => New_List (
3977 Make_Attribute_Reference (Loc,
3978 Attribute_Name => Name_Pos,
3979 Prefix => New_Occurrence_Of (Index, Loc),
3980 Expressions => New_List (New_Copy_Tree (Lo))),
3981 Right_Opnd => Length_Expr)));
3988 end Make_Literal_Range;
3990 ----------------------------
3991 -- Make_Subtype_From_Expr --
3992 ----------------------------
3994 -- 1. If Expr is an unconstrained array expression, creates
3995 -- Unc_Type(Expr'first(1)..Expr'last(1),..., Expr'first(n)..Expr'last(n))
3997 -- 2. If Expr is a unconstrained discriminated type expression, creates
3998 -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
4000 -- 3. If Expr is class-wide, creates an implicit class wide subtype
4002 function Make_Subtype_From_Expr
4004 Unc_Typ : Entity_Id) return Node_Id
4006 Loc : constant Source_Ptr := Sloc (E);
4007 List_Constr : constant List_Id := New_List;
4010 Full_Subtyp : Entity_Id;
4011 Priv_Subtyp : Entity_Id;
4016 if Is_Private_Type (Unc_Typ)
4017 and then Has_Unknown_Discriminants (Unc_Typ)
4019 -- Prepare the subtype completion, Go to base type to
4020 -- find underlying type, because the type may be a generic
4021 -- actual or an explicit subtype.
4023 Utyp := Underlying_Type (Base_Type (Unc_Typ));
4024 Full_Subtyp := Make_Defining_Identifier (Loc,
4025 New_Internal_Name ('C'));
4027 Unchecked_Convert_To
4028 (Utyp, Duplicate_Subexpr_No_Checks (E));
4029 Set_Parent (Full_Exp, Parent (E));
4032 Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
4035 Make_Subtype_Declaration (Loc,
4036 Defining_Identifier => Full_Subtyp,
4037 Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
4039 -- Define the dummy private subtype
4041 Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
4042 Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ));
4043 Set_Scope (Priv_Subtyp, Full_Subtyp);
4044 Set_Is_Constrained (Priv_Subtyp);
4045 Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
4046 Set_Is_Itype (Priv_Subtyp);
4047 Set_Associated_Node_For_Itype (Priv_Subtyp, E);
4049 if Is_Tagged_Type (Priv_Subtyp) then
4051 (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
4052 Set_Primitive_Operations (Priv_Subtyp,
4053 Primitive_Operations (Unc_Typ));
4056 Set_Full_View (Priv_Subtyp, Full_Subtyp);
4058 return New_Reference_To (Priv_Subtyp, Loc);
4060 elsif Is_Array_Type (Unc_Typ) then
4061 for J in 1 .. Number_Dimensions (Unc_Typ) loop
4062 Append_To (List_Constr,
4065 Make_Attribute_Reference (Loc,
4066 Prefix => Duplicate_Subexpr_No_Checks (E),
4067 Attribute_Name => Name_First,
4068 Expressions => New_List (
4069 Make_Integer_Literal (Loc, J))),
4072 Make_Attribute_Reference (Loc,
4073 Prefix => Duplicate_Subexpr_No_Checks (E),
4074 Attribute_Name => Name_Last,
4075 Expressions => New_List (
4076 Make_Integer_Literal (Loc, J)))));
4079 elsif Is_Class_Wide_Type (Unc_Typ) then
4081 CW_Subtype : Entity_Id;
4082 EQ_Typ : Entity_Id := Empty;
4085 -- A class-wide equivalent type is not needed when VM_Target
4086 -- because the VM back-ends handle the class-wide object
4087 -- initialization itself (and doesn't need or want the
4088 -- additional intermediate type to handle the assignment).
4090 if Expander_Active and then VM_Target = No_VM then
4091 EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
4094 CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
4095 Set_Equivalent_Type (CW_Subtype, EQ_Typ);
4097 if Present (EQ_Typ) then
4098 Set_Is_Class_Wide_Equivalent_Type (EQ_Typ);
4101 Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
4103 return New_Occurrence_Of (CW_Subtype, Loc);
4106 -- Indefinite record type with discriminants
4109 D := First_Discriminant (Unc_Typ);
4110 while Present (D) loop
4111 Append_To (List_Constr,
4112 Make_Selected_Component (Loc,
4113 Prefix => Duplicate_Subexpr_No_Checks (E),
4114 Selector_Name => New_Reference_To (D, Loc)));
4116 Next_Discriminant (D);
4121 Make_Subtype_Indication (Loc,
4122 Subtype_Mark => New_Reference_To (Unc_Typ, Loc),
4124 Make_Index_Or_Discriminant_Constraint (Loc,
4125 Constraints => List_Constr));
4126 end Make_Subtype_From_Expr;
4128 -----------------------------
4129 -- May_Generate_Large_Temp --
4130 -----------------------------
4132 -- At the current time, the only types that we return False for (i.e.
4133 -- where we decide we know they cannot generate large temps) are ones
4134 -- where we know the size is 256 bits or less at compile time, and we
4135 -- are still not doing a thorough job on arrays and records ???
4137 function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
4139 if not Size_Known_At_Compile_Time (Typ) then
4142 elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then
4145 elsif Is_Array_Type (Typ)
4146 and then Present (Packed_Array_Type (Typ))
4148 return May_Generate_Large_Temp (Packed_Array_Type (Typ));
4150 -- We could do more here to find other small types ???
4155 end May_Generate_Large_Temp;
4157 ----------------------------
4158 -- New_Class_Wide_Subtype --
4159 ----------------------------
4161 function New_Class_Wide_Subtype
4162 (CW_Typ : Entity_Id;
4163 N : Node_Id) return Entity_Id
4165 Res : constant Entity_Id := Create_Itype (E_Void, N);
4166 Res_Name : constant Name_Id := Chars (Res);
4167 Res_Scope : constant Entity_Id := Scope (Res);
4170 Copy_Node (CW_Typ, Res);
4171 Set_Comes_From_Source (Res, False);
4172 Set_Sloc (Res, Sloc (N));
4174 Set_Associated_Node_For_Itype (Res, N);
4175 Set_Is_Public (Res, False); -- By default, may be changed below.
4176 Set_Public_Status (Res);
4177 Set_Chars (Res, Res_Name);
4178 Set_Scope (Res, Res_Scope);
4179 Set_Ekind (Res, E_Class_Wide_Subtype);
4180 Set_Next_Entity (Res, Empty);
4181 Set_Etype (Res, Base_Type (CW_Typ));
4183 -- For targets where front-end layout is required, reset the Is_Frozen
4184 -- status of the subtype to False (it can be implicitly set to true
4185 -- from the copy of the class-wide type). For other targets, Gigi
4186 -- doesn't want the class-wide subtype to go through the freezing
4187 -- process (though it's unclear why that causes problems and it would
4188 -- be nice to allow freezing to occur normally for all targets ???).
4190 if Frontend_Layout_On_Target then
4191 Set_Is_Frozen (Res, False);
4194 Set_Freeze_Node (Res, Empty);
4196 end New_Class_Wide_Subtype;
4198 --------------------------------
4199 -- Non_Limited_Designated_Type --
4200 ---------------------------------
4202 function Non_Limited_Designated_Type (T : Entity_Id) return Entity_Id is
4203 Desig : constant Entity_Id := Designated_Type (T);
4205 if Ekind (Desig) = E_Incomplete_Type
4206 and then Present (Non_Limited_View (Desig))
4208 return Non_Limited_View (Desig);
4212 end Non_Limited_Designated_Type;
4214 -----------------------------------
4215 -- OK_To_Do_Constant_Replacement --
4216 -----------------------------------
4218 function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is
4219 ES : constant Entity_Id := Scope (E);
4223 -- Do not replace statically allocated objects, because they may be
4224 -- modified outside the current scope.
4226 if Is_Statically_Allocated (E) then
4229 -- Do not replace aliased or volatile objects, since we don't know what
4230 -- else might change the value.
4232 elsif Is_Aliased (E) or else Treat_As_Volatile (E) then
4235 -- Debug flag -gnatdM disconnects this optimization
4237 elsif Debug_Flag_MM then
4240 -- Otherwise check scopes
4243 CS := Current_Scope;
4246 -- If we are in right scope, replacement is safe
4251 -- Packages do not affect the determination of safety
4253 elsif Ekind (CS) = E_Package then
4254 exit when CS = Standard_Standard;
4257 -- Blocks do not affect the determination of safety
4259 elsif Ekind (CS) = E_Block then
4262 -- Loops do not affect the determination of safety. Note that we
4263 -- kill all current values on entry to a loop, so we are just
4264 -- talking about processing within a loop here.
4266 elsif Ekind (CS) = E_Loop then
4269 -- Otherwise, the reference is dubious, and we cannot be sure that
4270 -- it is safe to do the replacement.
4279 end OK_To_Do_Constant_Replacement;
4281 ------------------------------------
4282 -- Possible_Bit_Aligned_Component --
4283 ------------------------------------
4285 function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is
4289 -- Case of indexed component
4291 when N_Indexed_Component =>
4293 P : constant Node_Id := Prefix (N);
4294 Ptyp : constant Entity_Id := Etype (P);
4297 -- If we know the component size and it is less than 64, then
4298 -- we are definitely OK. The back end always does assignment
4299 -- of misaligned small objects correctly.
4301 if Known_Static_Component_Size (Ptyp)
4302 and then Component_Size (Ptyp) <= 64
4306 -- Otherwise, we need to test the prefix, to see if we are
4307 -- indexing from a possibly unaligned component.
4310 return Possible_Bit_Aligned_Component (P);
4314 -- Case of selected component
4316 when N_Selected_Component =>
4318 P : constant Node_Id := Prefix (N);
4319 Comp : constant Entity_Id := Entity (Selector_Name (N));
4322 -- If there is no component clause, then we are in the clear
4323 -- since the back end will never misalign a large component
4324 -- unless it is forced to do so. In the clear means we need
4325 -- only the recursive test on the prefix.
4327 if Component_May_Be_Bit_Aligned (Comp) then
4330 return Possible_Bit_Aligned_Component (P);
4334 -- For a slice, test the prefix, if that is possibly misaligned,
4335 -- then for sure the slice is!
4338 return Possible_Bit_Aligned_Component (Prefix (N));
4340 -- If we have none of the above, it means that we have fallen off the
4341 -- top testing prefixes recursively, and we now have a stand alone
4342 -- object, where we don't have a problem.
4348 end Possible_Bit_Aligned_Component;
4350 -------------------------
4351 -- Remove_Side_Effects --
4352 -------------------------
4354 procedure Remove_Side_Effects
4356 Name_Req : Boolean := False;
4357 Variable_Ref : Boolean := False)
4359 Loc : constant Source_Ptr := Sloc (Exp);
4360 Exp_Type : constant Entity_Id := Etype (Exp);
4361 Svg_Suppress : constant Suppress_Array := Scope_Suppress;
4363 Ref_Type : Entity_Id;
4365 Ptr_Typ_Decl : Node_Id;
4369 function Side_Effect_Free (N : Node_Id) return Boolean;
4370 -- Determines if the tree N represents an expression that is known not
4371 -- to have side effects, and for which no processing is required.
4373 function Side_Effect_Free (L : List_Id) return Boolean;
4374 -- Determines if all elements of the list L are side effect free
4376 function Safe_Prefixed_Reference (N : Node_Id) return Boolean;
4377 -- The argument N is a construct where the Prefix is dereferenced if it
4378 -- is an access type and the result is a variable. The call returns True
4379 -- if the construct is side effect free (not considering side effects in
4380 -- other than the prefix which are to be tested by the caller).
4382 function Within_In_Parameter (N : Node_Id) return Boolean;
4383 -- Determines if N is a subcomponent of a composite in-parameter. If so,
4384 -- N is not side-effect free when the actual is global and modifiable
4385 -- indirectly from within a subprogram, because it may be passed by
4386 -- reference. The front-end must be conservative here and assume that
4387 -- this may happen with any array or record type. On the other hand, we
4388 -- cannot create temporaries for all expressions for which this
4389 -- condition is true, for various reasons that might require clearing up
4390 -- ??? For example, discriminant references that appear out of place, or
4391 -- spurious type errors with class-wide expressions. As a result, we
4392 -- limit the transformation to loop bounds, which is so far the only
4393 -- case that requires it.
4395 -----------------------------
4396 -- Safe_Prefixed_Reference --
4397 -----------------------------
4399 function Safe_Prefixed_Reference (N : Node_Id) return Boolean is
4401 -- If prefix is not side effect free, definitely not safe
4403 if not Side_Effect_Free (Prefix (N)) then
4406 -- If the prefix is of an access type that is not access-to-constant,
4407 -- then this construct is a variable reference, which means it is to
4408 -- be considered to have side effects if Variable_Ref is set True
4409 -- Exception is an access to an entity that is a constant or an
4410 -- in-parameter which does not come from source, and is the result
4411 -- of a previous removal of side-effects.
4413 elsif Is_Access_Type (Etype (Prefix (N)))
4414 and then not Is_Access_Constant (Etype (Prefix (N)))
4415 and then Variable_Ref
4417 if not Is_Entity_Name (Prefix (N)) then
4420 return Ekind (Entity (Prefix (N))) = E_Constant
4421 or else Ekind (Entity (Prefix (N))) = E_In_Parameter;
4424 -- The following test is the simplest way of solving a complex
4425 -- problem uncovered by BB08-010: Side effect on loop bound that
4426 -- is a subcomponent of a global variable:
4427 -- If a loop bound is a subcomponent of a global variable, a
4428 -- modification of that variable within the loop may incorrectly
4429 -- affect the execution of the loop.
4432 (Nkind (Parent (Parent (N))) /= N_Loop_Parameter_Specification
4433 or else not Within_In_Parameter (Prefix (N)))
4437 -- All other cases are side effect free
4442 end Safe_Prefixed_Reference;
4444 ----------------------
4445 -- Side_Effect_Free --
4446 ----------------------
4448 function Side_Effect_Free (N : Node_Id) return Boolean is
4450 -- Note on checks that could raise Constraint_Error. Strictly, if
4451 -- we take advantage of 11.6, these checks do not count as side
4452 -- effects. However, we would just as soon consider that they are
4453 -- side effects, since the backend CSE does not work very well on
4454 -- expressions which can raise Constraint_Error. On the other
4455 -- hand, if we do not consider them to be side effect free, then
4456 -- we get some awkward expansions in -gnato mode, resulting in
4457 -- code insertions at a point where we do not have a clear model
4458 -- for performing the insertions.
4460 -- Special handling for entity names
4462 if Is_Entity_Name (N) then
4464 -- If the entity is a constant, it is definitely side effect
4465 -- free. Note that the test of Is_Variable (N) below might
4466 -- be expected to catch this case, but it does not, because
4467 -- this test goes to the original tree, and we may have
4468 -- already rewritten a variable node with a constant as
4469 -- a result of an earlier Force_Evaluation call.
4471 if Ekind (Entity (N)) = E_Constant
4472 or else Ekind (Entity (N)) = E_In_Parameter
4476 -- Functions are not side effect free
4478 elsif Ekind (Entity (N)) = E_Function then
4481 -- Variables are considered to be a side effect if Variable_Ref
4482 -- is set or if we have a volatile reference and Name_Req is off.
4483 -- If Name_Req is True then we can't help returning a name which
4484 -- effectively allows multiple references in any case.
4486 elsif Is_Variable (N) then
4487 return not Variable_Ref
4488 and then (not Is_Volatile_Reference (N) or else Name_Req);
4490 -- Any other entity (e.g. a subtype name) is definitely side
4497 -- A value known at compile time is always side effect free
4499 elsif Compile_Time_Known_Value (N) then
4502 -- A variable renaming is not side-effect free, because the
4503 -- renaming will function like a macro in the front-end in
4504 -- some cases, and an assignment can modify the component
4505 -- designated by N, so we need to create a temporary for it.
4507 elsif Is_Entity_Name (Original_Node (N))
4508 and then Is_Renaming_Of_Object (Entity (Original_Node (N)))
4509 and then Ekind (Entity (Original_Node (N))) /= E_Constant
4514 -- For other than entity names and compile time known values,
4515 -- check the node kind for special processing.
4519 -- An attribute reference is side effect free if its expressions
4520 -- are side effect free and its prefix is side effect free or
4521 -- is an entity reference.
4523 -- Is this right? what about x'first where x is a variable???
4525 when N_Attribute_Reference =>
4526 return Side_Effect_Free (Expressions (N))
4527 and then Attribute_Name (N) /= Name_Input
4528 and then (Is_Entity_Name (Prefix (N))
4529 or else Side_Effect_Free (Prefix (N)));
4531 -- A binary operator is side effect free if and both operands
4532 -- are side effect free. For this purpose binary operators
4533 -- include membership tests and short circuit forms
4539 return Side_Effect_Free (Left_Opnd (N))
4540 and then Side_Effect_Free (Right_Opnd (N));
4542 -- An explicit dereference is side effect free only if it is
4543 -- a side effect free prefixed reference.
4545 when N_Explicit_Dereference =>
4546 return Safe_Prefixed_Reference (N);
4548 -- A call to _rep_to_pos is side effect free, since we generate
4549 -- this pure function call ourselves. Moreover it is critically
4550 -- important to make this exception, since otherwise we can
4551 -- have discriminants in array components which don't look
4552 -- side effect free in the case of an array whose index type
4553 -- is an enumeration type with an enumeration rep clause.
4555 -- All other function calls are not side effect free
4557 when N_Function_Call =>
4558 return Nkind (Name (N)) = N_Identifier
4559 and then Is_TSS (Name (N), TSS_Rep_To_Pos)
4561 Side_Effect_Free (First (Parameter_Associations (N)));
4563 -- An indexed component is side effect free if it is a side
4564 -- effect free prefixed reference and all the indexing
4565 -- expressions are side effect free.
4567 when N_Indexed_Component =>
4568 return Side_Effect_Free (Expressions (N))
4569 and then Safe_Prefixed_Reference (N);
4571 -- A type qualification is side effect free if the expression
4572 -- is side effect free.
4574 when N_Qualified_Expression =>
4575 return Side_Effect_Free (Expression (N));
4577 -- A selected component is side effect free only if it is a
4578 -- side effect free prefixed reference. If it designates a
4579 -- component with a rep. clause it must be treated has having
4580 -- a potential side effect, because it may be modified through
4581 -- a renaming, and a subsequent use of the renaming as a macro
4582 -- will yield the wrong value. This complex interaction between
4583 -- renaming and removing side effects is a reminder that the
4584 -- latter has become a headache to maintain, and that it should
4585 -- be removed in favor of the gcc mechanism to capture values ???
4587 when N_Selected_Component =>
4588 if Nkind (Parent (N)) = N_Explicit_Dereference
4589 and then Has_Non_Standard_Rep (Designated_Type (Etype (N)))
4593 return Safe_Prefixed_Reference (N);
4596 -- A range is side effect free if the bounds are side effect free
4599 return Side_Effect_Free (Low_Bound (N))
4600 and then Side_Effect_Free (High_Bound (N));
4602 -- A slice is side effect free if it is a side effect free
4603 -- prefixed reference and the bounds are side effect free.
4606 return Side_Effect_Free (Discrete_Range (N))
4607 and then Safe_Prefixed_Reference (N);
4609 -- A type conversion is side effect free if the expression to be
4610 -- converted is side effect free.
4612 when N_Type_Conversion =>
4613 return Side_Effect_Free (Expression (N));
4615 -- A unary operator is side effect free if the operand
4616 -- is side effect free.
4619 return Side_Effect_Free (Right_Opnd (N));
4621 -- An unchecked type conversion is side effect free only if it
4622 -- is safe and its argument is side effect free.
4624 when N_Unchecked_Type_Conversion =>
4625 return Safe_Unchecked_Type_Conversion (N)
4626 and then Side_Effect_Free (Expression (N));
4628 -- An unchecked expression is side effect free if its expression
4629 -- is side effect free.
4631 when N_Unchecked_Expression =>
4632 return Side_Effect_Free (Expression (N));
4634 -- A literal is side effect free
4636 when N_Character_Literal |
4642 -- We consider that anything else has side effects. This is a bit
4643 -- crude, but we are pretty close for most common cases, and we
4644 -- are certainly correct (i.e. we never return True when the
4645 -- answer should be False).
4650 end Side_Effect_Free;
4652 -- A list is side effect free if all elements of the list are
4653 -- side effect free.
4655 function Side_Effect_Free (L : List_Id) return Boolean is
4659 if L = No_List or else L = Error_List then
4664 while Present (N) loop
4665 if not Side_Effect_Free (N) then
4674 end Side_Effect_Free;
4676 -------------------------
4677 -- Within_In_Parameter --
4678 -------------------------
4680 function Within_In_Parameter (N : Node_Id) return Boolean is
4682 if not Comes_From_Source (N) then
4685 elsif Is_Entity_Name (N) then
4686 return Ekind (Entity (N)) = E_In_Parameter;
4688 elsif Nkind (N) = N_Indexed_Component
4689 or else Nkind (N) = N_Selected_Component
4691 return Within_In_Parameter (Prefix (N));
4696 end Within_In_Parameter;
4698 -- Start of processing for Remove_Side_Effects
4701 -- If we are side effect free already or expansion is disabled,
4702 -- there is nothing to do.
4704 if Side_Effect_Free (Exp) or else not Expander_Active then
4708 -- All this must not have any checks
4710 Scope_Suppress := (others => True);
4712 -- If it is a scalar type and we need to capture the value, just make
4713 -- a copy. Likewise for a function call, an attribute reference or an
4714 -- operator. And if we have a volatile reference and Name_Req is not
4715 -- set (see comments above for Side_Effect_Free).
4717 if Is_Elementary_Type (Exp_Type)
4718 and then (Variable_Ref
4719 or else Nkind (Exp) = N_Function_Call
4720 or else Nkind (Exp) = N_Attribute_Reference
4721 or else Nkind (Exp) in N_Op
4722 or else (not Name_Req and then Is_Volatile_Reference (Exp)))
4724 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4725 Set_Etype (Def_Id, Exp_Type);
4726 Res := New_Reference_To (Def_Id, Loc);
4729 Make_Object_Declaration (Loc,
4730 Defining_Identifier => Def_Id,
4731 Object_Definition => New_Reference_To (Exp_Type, Loc),
4732 Constant_Present => True,
4733 Expression => Relocate_Node (Exp));
4735 Set_Assignment_OK (E);
4736 Insert_Action (Exp, E);
4738 -- If the expression has the form v.all then we can just capture
4739 -- the pointer, and then do an explicit dereference on the result.
4741 elsif Nkind (Exp) = N_Explicit_Dereference then
4743 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4745 Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc));
4748 Make_Object_Declaration (Loc,
4749 Defining_Identifier => Def_Id,
4750 Object_Definition =>
4751 New_Reference_To (Etype (Prefix (Exp)), Loc),
4752 Constant_Present => True,
4753 Expression => Relocate_Node (Prefix (Exp))));
4755 -- Similar processing for an unchecked conversion of an expression
4756 -- of the form v.all, where we want the same kind of treatment.
4758 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4759 and then Nkind (Expression (Exp)) = N_Explicit_Dereference
4761 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4762 Scope_Suppress := Svg_Suppress;
4765 -- If this is a type conversion, leave the type conversion and remove
4766 -- the side effects in the expression. This is important in several
4767 -- circumstances: for change of representations, and also when this is
4768 -- a view conversion to a smaller object, where gigi can end up creating
4769 -- its own temporary of the wrong size.
4771 elsif Nkind (Exp) = N_Type_Conversion then
4772 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4773 Scope_Suppress := Svg_Suppress;
4776 -- If this is an unchecked conversion that Gigi can't handle, make
4777 -- a copy or a use a renaming to capture the value.
4779 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4780 and then not Safe_Unchecked_Type_Conversion (Exp)
4782 if CW_Or_Controlled_Type (Exp_Type) then
4784 -- Use a renaming to capture the expression, rather than create
4785 -- a controlled temporary.
4787 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4788 Res := New_Reference_To (Def_Id, Loc);
4791 Make_Object_Renaming_Declaration (Loc,
4792 Defining_Identifier => Def_Id,
4793 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4794 Name => Relocate_Node (Exp)));
4797 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4798 Set_Etype (Def_Id, Exp_Type);
4799 Res := New_Reference_To (Def_Id, Loc);
4802 Make_Object_Declaration (Loc,
4803 Defining_Identifier => Def_Id,
4804 Object_Definition => New_Reference_To (Exp_Type, Loc),
4805 Constant_Present => not Is_Variable (Exp),
4806 Expression => Relocate_Node (Exp));
4808 Set_Assignment_OK (E);
4809 Insert_Action (Exp, E);
4812 -- For expressions that denote objects, we can use a renaming scheme.
4813 -- We skip using this if we have a volatile reference and we do not
4814 -- have Name_Req set true (see comments above for Side_Effect_Free).
4816 elsif Is_Object_Reference (Exp)
4817 and then Nkind (Exp) /= N_Function_Call
4818 and then (Name_Req or else not Is_Volatile_Reference (Exp))
4820 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4822 if Nkind (Exp) = N_Selected_Component
4823 and then Nkind (Prefix (Exp)) = N_Function_Call
4824 and then Is_Array_Type (Exp_Type)
4826 -- Avoid generating a variable-sized temporary, by generating
4827 -- the renaming declaration just for the function call. The
4828 -- transformation could be refined to apply only when the array
4829 -- component is constrained by a discriminant???
4832 Make_Selected_Component (Loc,
4833 Prefix => New_Occurrence_Of (Def_Id, Loc),
4834 Selector_Name => Selector_Name (Exp));
4837 Make_Object_Renaming_Declaration (Loc,
4838 Defining_Identifier => Def_Id,
4840 New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc),
4841 Name => Relocate_Node (Prefix (Exp))));
4844 Res := New_Reference_To (Def_Id, Loc);
4847 Make_Object_Renaming_Declaration (Loc,
4848 Defining_Identifier => Def_Id,
4849 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4850 Name => Relocate_Node (Exp)));
4854 -- If this is a packed reference, or a selected component with a
4855 -- non-standard representation, a reference to the temporary will
4856 -- be replaced by a copy of the original expression (see
4857 -- Exp_Ch2.Expand_Renaming). Otherwise the temporary must be
4858 -- elaborated by gigi, and is of course not to be replaced in-line
4859 -- by the expression it renames, which would defeat the purpose of
4860 -- removing the side-effect.
4862 if (Nkind (Exp) = N_Selected_Component
4863 or else Nkind (Exp) = N_Indexed_Component)
4864 and then Has_Non_Standard_Rep (Etype (Prefix (Exp)))
4868 Set_Is_Renaming_Of_Object (Def_Id, False);
4871 -- Otherwise we generate a reference to the value
4874 -- Special processing for function calls that return a task. We need
4875 -- to build a declaration that will enable build-in-place expansion
4878 -- This is relevant only in Ada 2005 mode. In Ada 95 programs we have
4879 -- to accommodate functions returning limited objects by reference.
4881 if Nkind (Exp) = N_Function_Call
4882 and then Is_Task_Type (Etype (Exp))
4883 and then Ada_Version >= Ada_05
4886 Obj : constant Entity_Id :=
4887 Make_Defining_Identifier (Loc,
4888 Chars => New_Internal_Name ('F'));
4893 Make_Object_Declaration (Loc,
4894 Defining_Identifier => Obj,
4895 Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
4896 Expression => Relocate_Node (Exp));
4897 Insert_Action (Exp, Decl);
4898 Set_Etype (Obj, Exp_Type);
4899 Rewrite (Exp, New_Occurrence_Of (Obj, Loc));
4904 Ref_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
4907 Make_Full_Type_Declaration (Loc,
4908 Defining_Identifier => Ref_Type,
4910 Make_Access_To_Object_Definition (Loc,
4911 All_Present => True,
4912 Subtype_Indication =>
4913 New_Reference_To (Exp_Type, Loc)));
4916 Insert_Action (Exp, Ptr_Typ_Decl);
4918 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4919 Set_Etype (Def_Id, Exp_Type);
4922 Make_Explicit_Dereference (Loc,
4923 Prefix => New_Reference_To (Def_Id, Loc));
4925 if Nkind (E) = N_Explicit_Dereference then
4926 New_Exp := Relocate_Node (Prefix (E));
4928 E := Relocate_Node (E);
4929 New_Exp := Make_Reference (Loc, E);
4932 if Is_Delayed_Aggregate (E) then
4934 -- The expansion of nested aggregates is delayed until the
4935 -- enclosing aggregate is expanded. As aggregates are often
4936 -- qualified, the predicate applies to qualified expressions
4937 -- as well, indicating that the enclosing aggregate has not
4938 -- been expanded yet. At this point the aggregate is part of
4939 -- a stand-alone declaration, and must be fully expanded.
4941 if Nkind (E) = N_Qualified_Expression then
4942 Set_Expansion_Delayed (Expression (E), False);
4943 Set_Analyzed (Expression (E), False);
4945 Set_Expansion_Delayed (E, False);
4948 Set_Analyzed (E, False);
4952 Make_Object_Declaration (Loc,
4953 Defining_Identifier => Def_Id,
4954 Object_Definition => New_Reference_To (Ref_Type, Loc),
4955 Expression => New_Exp));
4958 -- Preserve the Assignment_OK flag in all copies, since at least
4959 -- one copy may be used in a context where this flag must be set
4960 -- (otherwise why would the flag be set in the first place).
4962 Set_Assignment_OK (Res, Assignment_OK (Exp));
4964 -- Finally rewrite the original expression and we are done
4967 Analyze_And_Resolve (Exp, Exp_Type);
4968 Scope_Suppress := Svg_Suppress;
4969 end Remove_Side_Effects;
4971 ---------------------------
4972 -- Represented_As_Scalar --
4973 ---------------------------
4975 function Represented_As_Scalar (T : Entity_Id) return Boolean is
4976 UT : constant Entity_Id := Underlying_Type (T);
4978 return Is_Scalar_Type (UT)
4979 or else (Is_Bit_Packed_Array (UT)
4980 and then Is_Scalar_Type (Packed_Array_Type (UT)));
4981 end Represented_As_Scalar;
4983 ------------------------------------
4984 -- Safe_Unchecked_Type_Conversion --
4985 ------------------------------------
4987 -- Note: this function knows quite a bit about the exact requirements
4988 -- of Gigi with respect to unchecked type conversions, and its code
4989 -- must be coordinated with any changes in Gigi in this area.
4991 -- The above requirements should be documented in Sinfo ???
4993 function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
4998 Pexp : constant Node_Id := Parent (Exp);
5001 -- If the expression is the RHS of an assignment or object declaration
5002 -- we are always OK because there will always be a target.
5004 -- Object renaming declarations, (generated for view conversions of
5005 -- actuals in inlined calls), like object declarations, provide an
5006 -- explicit type, and are safe as well.
5008 if (Nkind (Pexp) = N_Assignment_Statement
5009 and then Expression (Pexp) = Exp)
5010 or else Nkind (Pexp) = N_Object_Declaration
5011 or else Nkind (Pexp) = N_Object_Renaming_Declaration
5015 -- If the expression is the prefix of an N_Selected_Component
5016 -- we should also be OK because GCC knows to look inside the
5017 -- conversion except if the type is discriminated. We assume
5018 -- that we are OK anyway if the type is not set yet or if it is
5019 -- controlled since we can't afford to introduce a temporary in
5022 elsif Nkind (Pexp) = N_Selected_Component
5023 and then Prefix (Pexp) = Exp
5025 if No (Etype (Pexp)) then
5029 not Has_Discriminants (Etype (Pexp))
5030 or else Is_Constrained (Etype (Pexp));
5034 -- Set the output type, this comes from Etype if it is set, otherwise
5035 -- we take it from the subtype mark, which we assume was already
5038 if Present (Etype (Exp)) then
5039 Otyp := Etype (Exp);
5041 Otyp := Entity (Subtype_Mark (Exp));
5044 -- The input type always comes from the expression, and we assume
5045 -- this is indeed always analyzed, so we can simply get the Etype.
5047 Ityp := Etype (Expression (Exp));
5049 -- Initialize alignments to unknown so far
5054 -- Replace a concurrent type by its corresponding record type
5055 -- and each type by its underlying type and do the tests on those.
5056 -- The original type may be a private type whose completion is a
5057 -- concurrent type, so find the underlying type first.
5059 if Present (Underlying_Type (Otyp)) then
5060 Otyp := Underlying_Type (Otyp);
5063 if Present (Underlying_Type (Ityp)) then
5064 Ityp := Underlying_Type (Ityp);
5067 if Is_Concurrent_Type (Otyp) then
5068 Otyp := Corresponding_Record_Type (Otyp);
5071 if Is_Concurrent_Type (Ityp) then
5072 Ityp := Corresponding_Record_Type (Ityp);
5075 -- If the base types are the same, we know there is no problem since
5076 -- this conversion will be a noop.
5078 if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
5081 -- Same if this is an upwards conversion of an untagged type, and there
5082 -- are no constraints involved (could be more general???)
5084 elsif Etype (Ityp) = Otyp
5085 and then not Is_Tagged_Type (Ityp)
5086 and then not Has_Discriminants (Ityp)
5087 and then No (First_Rep_Item (Base_Type (Ityp)))
5091 -- If the size of output type is known at compile time, there is
5092 -- never a problem. Note that unconstrained records are considered
5093 -- to be of known size, but we can't consider them that way here,
5094 -- because we are talking about the actual size of the object.
5096 -- We also make sure that in addition to the size being known, we do
5097 -- not have a case which might generate an embarrassingly large temp
5098 -- in stack checking mode.
5100 elsif Size_Known_At_Compile_Time (Otyp)
5102 (not Stack_Checking_Enabled
5103 or else not May_Generate_Large_Temp (Otyp))
5104 and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
5108 -- If either type is tagged, then we know the alignment is OK so
5109 -- Gigi will be able to use pointer punning.
5111 elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
5114 -- If either type is a limited record type, we cannot do a copy, so
5115 -- say safe since there's nothing else we can do.
5117 elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
5120 -- Conversions to and from packed array types are always ignored and
5123 elsif Is_Packed_Array_Type (Otyp)
5124 or else Is_Packed_Array_Type (Ityp)
5129 -- The only other cases known to be safe is if the input type's
5130 -- alignment is known to be at least the maximum alignment for the
5131 -- target or if both alignments are known and the output type's
5132 -- alignment is no stricter than the input's. We can use the alignment
5133 -- of the component type of an array if a type is an unpacked
5136 if Present (Alignment_Clause (Otyp)) then
5137 Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
5139 elsif Is_Array_Type (Otyp)
5140 and then Present (Alignment_Clause (Component_Type (Otyp)))
5142 Oalign := Expr_Value (Expression (Alignment_Clause
5143 (Component_Type (Otyp))));
5146 if Present (Alignment_Clause (Ityp)) then
5147 Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
5149 elsif Is_Array_Type (Ityp)
5150 and then Present (Alignment_Clause (Component_Type (Ityp)))
5152 Ialign := Expr_Value (Expression (Alignment_Clause
5153 (Component_Type (Ityp))));
5156 if Ialign /= No_Uint and then Ialign > Maximum_Alignment then
5159 elsif Ialign /= No_Uint and then Oalign /= No_Uint
5160 and then Ialign <= Oalign
5164 -- Otherwise, Gigi cannot handle this and we must make a temporary
5169 end Safe_Unchecked_Type_Conversion;
5171 ---------------------------------
5172 -- Set_Current_Value_Condition --
5173 ---------------------------------
5175 -- Note: the implementation of this procedure is very closely tied to the
5176 -- implementation of Get_Current_Value_Condition. Here we set required
5177 -- Current_Value fields, and in Get_Current_Value_Condition, we interpret
5178 -- them, so they must have a consistent view.
5180 procedure Set_Current_Value_Condition (Cnode : Node_Id) is
5182 procedure Set_Entity_Current_Value (N : Node_Id);
5183 -- If N is an entity reference, where the entity is of an appropriate
5184 -- kind, then set the current value of this entity to Cnode, unless
5185 -- there is already a definite value set there.
5187 procedure Set_Expression_Current_Value (N : Node_Id);
5188 -- If N is of an appropriate form, sets an appropriate entry in current
5189 -- value fields of relevant entities. Multiple entities can be affected
5190 -- in the case of an AND or AND THEN.
5192 ------------------------------
5193 -- Set_Entity_Current_Value --
5194 ------------------------------
5196 procedure Set_Entity_Current_Value (N : Node_Id) is
5198 if Is_Entity_Name (N) then
5200 Ent : constant Entity_Id := Entity (N);
5203 -- Don't capture if not safe to do so
5205 if not Safe_To_Capture_Value (N, Ent, Cond => True) then
5209 -- Here we have a case where the Current_Value field may
5210 -- need to be set. We set it if it is not already set to a
5211 -- compile time expression value.
5213 -- Note that this represents a decision that one condition
5214 -- blots out another previous one. That's certainly right
5215 -- if they occur at the same level. If the second one is
5216 -- nested, then the decision is neither right nor wrong (it
5217 -- would be equally OK to leave the outer one in place, or
5218 -- take the new inner one. Really we should record both, but
5219 -- our data structures are not that elaborate.
5221 if Nkind (Current_Value (Ent)) not in N_Subexpr then
5222 Set_Current_Value (Ent, Cnode);
5226 end Set_Entity_Current_Value;
5228 ----------------------------------
5229 -- Set_Expression_Current_Value --
5230 ----------------------------------
5232 procedure Set_Expression_Current_Value (N : Node_Id) is
5238 -- Loop to deal with (ignore for now) any NOT operators present. The
5239 -- presence of NOT operators will be handled properly when we call
5240 -- Get_Current_Value_Condition.
5242 while Nkind (Cond) = N_Op_Not loop
5243 Cond := Right_Opnd (Cond);
5246 -- For an AND or AND THEN, recursively process operands
5248 if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then
5249 Set_Expression_Current_Value (Left_Opnd (Cond));
5250 Set_Expression_Current_Value (Right_Opnd (Cond));
5254 -- Check possible relational operator
5256 if Nkind (Cond) in N_Op_Compare then
5257 if Compile_Time_Known_Value (Right_Opnd (Cond)) then
5258 Set_Entity_Current_Value (Left_Opnd (Cond));
5259 elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then
5260 Set_Entity_Current_Value (Right_Opnd (Cond));
5263 -- Check possible boolean variable reference
5266 Set_Entity_Current_Value (Cond);
5268 end Set_Expression_Current_Value;
5270 -- Start of processing for Set_Current_Value_Condition
5273 Set_Expression_Current_Value (Condition (Cnode));
5274 end Set_Current_Value_Condition;
5276 --------------------------
5277 -- Set_Elaboration_Flag --
5278 --------------------------
5280 procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
5281 Loc : constant Source_Ptr := Sloc (N);
5282 Ent : constant Entity_Id := Elaboration_Entity (Spec_Id);
5286 if Present (Ent) then
5288 -- Nothing to do if at the compilation unit level, because in this
5289 -- case the flag is set by the binder generated elaboration routine.
5291 if Nkind (Parent (N)) = N_Compilation_Unit then
5294 -- Here we do need to generate an assignment statement
5297 Check_Restriction (No_Elaboration_Code, N);
5299 Make_Assignment_Statement (Loc,
5300 Name => New_Occurrence_Of (Ent, Loc),
5301 Expression => New_Occurrence_Of (Standard_True, Loc));
5303 if Nkind (Parent (N)) = N_Subunit then
5304 Insert_After (Corresponding_Stub (Parent (N)), Asn);
5306 Insert_After (N, Asn);
5311 -- Kill current value indication. This is necessary because the
5312 -- tests of this flag are inserted out of sequence and must not
5313 -- pick up bogus indications of the wrong constant value.
5315 Set_Current_Value (Ent, Empty);
5318 end Set_Elaboration_Flag;
5320 ----------------------------
5321 -- Set_Renamed_Subprogram --
5322 ----------------------------
5324 procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is
5326 -- If input node is an identifier, we can just reset it
5328 if Nkind (N) = N_Identifier then
5329 Set_Chars (N, Chars (E));
5332 -- Otherwise we have to do a rewrite, preserving Comes_From_Source
5336 CS : constant Boolean := Comes_From_Source (N);
5338 Rewrite (N, Make_Identifier (Sloc (N), Chars => Chars (E)));
5340 Set_Comes_From_Source (N, CS);
5341 Set_Analyzed (N, True);
5344 end Set_Renamed_Subprogram;
5346 ----------------------------------
5347 -- Silly_Boolean_Array_Not_Test --
5348 ----------------------------------
5350 -- This procedure implements an odd and silly test. We explicitly check
5351 -- for the case where the 'First of the component type is equal to the
5352 -- 'Last of this component type, and if this is the case, we make sure
5353 -- that constraint error is raised. The reason is that the NOT is bound
5354 -- to cause CE in this case, and we will not otherwise catch it.
5356 -- Believe it or not, this was reported as a bug. Note that nearly
5357 -- always, the test will evaluate statically to False, so the code will
5358 -- be statically removed, and no extra overhead caused.
5360 procedure Silly_Boolean_Array_Not_Test (N : Node_Id; T : Entity_Id) is
5361 Loc : constant Source_Ptr := Sloc (N);
5362 CT : constant Entity_Id := Component_Type (T);
5366 Make_Raise_Constraint_Error (Loc,
5370 Make_Attribute_Reference (Loc,
5371 Prefix => New_Occurrence_Of (CT, Loc),
5372 Attribute_Name => Name_First),
5375 Make_Attribute_Reference (Loc,
5376 Prefix => New_Occurrence_Of (CT, Loc),
5377 Attribute_Name => Name_Last)),
5378 Reason => CE_Range_Check_Failed));
5379 end Silly_Boolean_Array_Not_Test;
5381 ----------------------------------
5382 -- Silly_Boolean_Array_Xor_Test --
5383 ----------------------------------
5385 -- This procedure implements an odd and silly test. We explicitly check
5386 -- for the XOR case where the component type is True .. True, since this
5387 -- will raise constraint error. A special check is required since CE
5388 -- will not be required otherwise (cf Expand_Packed_Not).
5390 -- No such check is required for AND and OR, since for both these cases
5391 -- False op False = False, and True op True = True.
5393 procedure Silly_Boolean_Array_Xor_Test (N : Node_Id; T : Entity_Id) is
5394 Loc : constant Source_Ptr := Sloc (N);
5395 CT : constant Entity_Id := Component_Type (T);
5396 BT : constant Entity_Id := Base_Type (CT);
5400 Make_Raise_Constraint_Error (Loc,
5406 Make_Attribute_Reference (Loc,
5407 Prefix => New_Occurrence_Of (CT, Loc),
5408 Attribute_Name => Name_First),
5412 New_Occurrence_Of (Standard_True, Loc))),
5417 Make_Attribute_Reference (Loc,
5418 Prefix => New_Occurrence_Of (CT, Loc),
5419 Attribute_Name => Name_Last),
5423 New_Occurrence_Of (Standard_True, Loc)))),
5424 Reason => CE_Range_Check_Failed));
5425 end Silly_Boolean_Array_Xor_Test;
5427 --------------------------
5428 -- Target_Has_Fixed_Ops --
5429 --------------------------
5431 Integer_Sized_Small : Ureal;
5432 -- Set to 2.0 ** -(Integer'Size - 1) the first time that this
5433 -- function is called (we don't want to compute it more than once!)
5435 Long_Integer_Sized_Small : Ureal;
5436 -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this
5437 -- function is called (we don't want to compute it more than once)
5439 First_Time_For_THFO : Boolean := True;
5440 -- Set to False after first call (if Fractional_Fixed_Ops_On_Target)
5442 function Target_Has_Fixed_Ops
5443 (Left_Typ : Entity_Id;
5444 Right_Typ : Entity_Id;
5445 Result_Typ : Entity_Id) return Boolean
5447 function Is_Fractional_Type (Typ : Entity_Id) return Boolean;
5448 -- Return True if the given type is a fixed-point type with a small
5449 -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have
5450 -- an absolute value less than 1.0. This is currently limited
5451 -- to fixed-point types that map to Integer or Long_Integer.
5453 ------------------------
5454 -- Is_Fractional_Type --
5455 ------------------------
5457 function Is_Fractional_Type (Typ : Entity_Id) return Boolean is
5459 if Esize (Typ) = Standard_Integer_Size then
5460 return Small_Value (Typ) = Integer_Sized_Small;
5462 elsif Esize (Typ) = Standard_Long_Integer_Size then
5463 return Small_Value (Typ) = Long_Integer_Sized_Small;
5468 end Is_Fractional_Type;
5470 -- Start of processing for Target_Has_Fixed_Ops
5473 -- Return False if Fractional_Fixed_Ops_On_Target is false
5475 if not Fractional_Fixed_Ops_On_Target then
5479 -- Here the target has Fractional_Fixed_Ops, if first time, compute
5480 -- standard constants used by Is_Fractional_Type.
5482 if First_Time_For_THFO then
5483 First_Time_For_THFO := False;
5485 Integer_Sized_Small :=
5488 Den => UI_From_Int (Standard_Integer_Size - 1),
5491 Long_Integer_Sized_Small :=
5494 Den => UI_From_Int (Standard_Long_Integer_Size - 1),
5498 -- Return True if target supports fixed-by-fixed multiply/divide
5499 -- for fractional fixed-point types (see Is_Fractional_Type) and
5500 -- the operand and result types are equivalent fractional types.
5502 return Is_Fractional_Type (Base_Type (Left_Typ))
5503 and then Is_Fractional_Type (Base_Type (Right_Typ))
5504 and then Is_Fractional_Type (Base_Type (Result_Typ))
5505 and then Esize (Left_Typ) = Esize (Right_Typ)
5506 and then Esize (Left_Typ) = Esize (Result_Typ);
5507 end Target_Has_Fixed_Ops;
5509 ------------------------------------------
5510 -- Type_May_Have_Bit_Aligned_Components --
5511 ------------------------------------------
5513 function Type_May_Have_Bit_Aligned_Components
5514 (Typ : Entity_Id) return Boolean
5517 -- Array type, check component type
5519 if Is_Array_Type (Typ) then
5521 Type_May_Have_Bit_Aligned_Components (Component_Type (Typ));
5523 -- Record type, check components
5525 elsif Is_Record_Type (Typ) then
5530 E := First_Component_Or_Discriminant (Typ);
5531 while Present (E) loop
5532 if Component_May_Be_Bit_Aligned (E)
5533 or else Type_May_Have_Bit_Aligned_Components (Etype (E))
5538 Next_Component_Or_Discriminant (E);
5544 -- Type other than array or record is always OK
5549 end Type_May_Have_Bit_Aligned_Components;
5551 ----------------------------
5552 -- Wrap_Cleanup_Procedure --
5553 ----------------------------
5555 procedure Wrap_Cleanup_Procedure (N : Node_Id) is
5556 Loc : constant Source_Ptr := Sloc (N);
5557 Stseq : constant Node_Id := Handled_Statement_Sequence (N);
5558 Stmts : constant List_Id := Statements (Stseq);
5561 if Abort_Allowed then
5562 Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
5563 Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));
5565 end Wrap_Cleanup_Procedure;