1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2007, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Debug; use Debug;
30 with Einfo; use Einfo;
31 with Elists; use Elists;
32 with Errout; use Errout;
33 with Exp_Aggr; use Exp_Aggr;
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
92 Decls : in out List_Id;
93 Stats : in out List_Id);
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 function New_Class_Wide_Subtype
133 N : Node_Id) return Entity_Id;
134 -- Create an implicit subtype of CW_Typ attached to node N
136 ----------------------
137 -- Adjust_Condition --
138 ----------------------
140 procedure Adjust_Condition (N : Node_Id) is
147 Loc : constant Source_Ptr := Sloc (N);
148 T : constant Entity_Id := Etype (N);
152 -- For now, we simply ignore a call where the argument has no
153 -- type (probably case of unanalyzed condition), or has a type
154 -- that is not Boolean. This is because this is a pretty marginal
155 -- piece of functionality, and violations of these rules are
156 -- likely to be truly marginal (how much code uses Fortran Logical
157 -- as the barrier to a protected entry?) and we do not want to
158 -- blow up existing programs. We can change this to an assertion
159 -- after 3.12a is released ???
161 if No (T) or else not Is_Boolean_Type (T) then
165 -- Apply validity checking if needed
167 if Validity_Checks_On and Validity_Check_Tests then
171 -- Immediate return if standard boolean, the most common case,
172 -- where nothing needs to be done.
174 if Base_Type (T) = Standard_Boolean then
178 -- Case of zero/non-zero semantics or non-standard enumeration
179 -- representation. In each case, we rewrite the node as:
181 -- ityp!(N) /= False'Enum_Rep
183 -- where ityp is an integer type with large enough size to hold
184 -- any value of type T.
186 if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then
187 if Esize (T) <= Esize (Standard_Integer) then
188 Ti := Standard_Integer;
190 Ti := Standard_Long_Long_Integer;
195 Left_Opnd => Unchecked_Convert_To (Ti, N),
197 Make_Attribute_Reference (Loc,
198 Attribute_Name => Name_Enum_Rep,
200 New_Occurrence_Of (First_Literal (T), Loc))));
201 Analyze_And_Resolve (N, Standard_Boolean);
204 Rewrite (N, Convert_To (Standard_Boolean, N));
205 Analyze_And_Resolve (N, Standard_Boolean);
208 end Adjust_Condition;
210 ------------------------
211 -- Adjust_Result_Type --
212 ------------------------
214 procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is
216 -- Ignore call if current type is not Standard.Boolean
218 if Etype (N) /= Standard_Boolean then
222 -- If result is already of correct type, nothing to do. Note that
223 -- this will get the most common case where everything has a type
224 -- of Standard.Boolean.
226 if Base_Type (T) = Standard_Boolean then
231 KP : constant Node_Kind := Nkind (Parent (N));
234 -- If result is to be used as a Condition in the syntax, no need
235 -- to convert it back, since if it was changed to Standard.Boolean
236 -- using Adjust_Condition, that is just fine for this usage.
238 if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then
241 -- If result is an operand of another logical operation, no need
242 -- to reset its type, since Standard.Boolean is just fine, and
243 -- such operations always do Adjust_Condition on their operands.
245 elsif KP in N_Op_Boolean
246 or else KP = N_And_Then
247 or else KP = N_Or_Else
248 or else KP = N_Op_Not
252 -- Otherwise we perform a conversion from the current type,
253 -- which must be Standard.Boolean, to the desired type.
257 Rewrite (N, Convert_To (T, N));
258 Analyze_And_Resolve (N, T);
262 end Adjust_Result_Type;
264 --------------------------
265 -- Append_Freeze_Action --
266 --------------------------
268 procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is
272 Ensure_Freeze_Node (T);
273 Fnode := Freeze_Node (T);
275 if No (Actions (Fnode)) then
276 Set_Actions (Fnode, New_List);
279 Append (N, Actions (Fnode));
280 end Append_Freeze_Action;
282 ---------------------------
283 -- Append_Freeze_Actions --
284 ---------------------------
286 procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is
287 Fnode : constant Node_Id := Freeze_Node (T);
294 if No (Actions (Fnode)) then
295 Set_Actions (Fnode, L);
298 Append_List (L, Actions (Fnode));
302 end Append_Freeze_Actions;
304 ------------------------
305 -- Build_Runtime_Call --
306 ------------------------
308 function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is
310 -- If entity is not available, we can skip making the call (this avoids
311 -- junk duplicated error messages in a number of cases).
313 if not RTE_Available (RE) then
314 return Make_Null_Statement (Loc);
317 Make_Procedure_Call_Statement (Loc,
318 Name => New_Reference_To (RTE (RE), Loc));
320 end Build_Runtime_Call;
322 ----------------------------
323 -- Build_Task_Array_Image --
324 ----------------------------
326 -- This function generates the body for a function that constructs the
327 -- image string for a task that is an array component. The function is
328 -- local to the init proc for the array type, and is called for each one
329 -- of the components. The constructed image has the form of an indexed
330 -- component, whose prefix is the outer variable of the array type.
331 -- The n-dimensional array type has known indices Index, Index2...
332 -- Id_Ref is an indexed component form created by the enclosing init proc.
333 -- Its successive indices are Val1, Val2,.. which are the loop variables
334 -- in the loops that call the individual task init proc on each component.
336 -- The generated function has the following structure:
338 -- function F return String is
339 -- Pref : string renames Task_Name;
340 -- T1 : String := Index1'Image (Val1);
342 -- Tn : String := indexn'image (Valn);
343 -- Len : Integer := T1'Length + ... + Tn'Length + n + 1;
344 -- -- Len includes commas and the end parentheses.
345 -- Res : String (1..Len);
346 -- Pos : Integer := Pref'Length;
349 -- Res (1 .. Pos) := Pref;
353 -- Res (Pos .. Pos + T1'Length - 1) := T1;
354 -- Pos := Pos + T1'Length;
358 -- Res (Pos .. Pos + Tn'Length - 1) := Tn;
364 -- Needless to say, multidimensional arrays of tasks are rare enough
365 -- that the bulkiness of this code is not really a concern.
367 function Build_Task_Array_Image
371 Dyn : Boolean := False) return Node_Id
373 Dims : constant Nat := Number_Dimensions (A_Type);
374 -- Number of dimensions for array of tasks
376 Temps : array (1 .. Dims) of Entity_Id;
377 -- Array of temporaries to hold string for each index
383 -- Total length of generated name
386 -- Running index for substring assignments
389 -- Name of enclosing variable, prefix of resulting name
392 -- String to hold result
395 -- Value of successive indices
398 -- Expression to compute total size of string
401 -- Entity for name at one index position
403 Decls : List_Id := New_List;
404 Stats : List_Id := New_List;
407 Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
409 -- For a dynamic task, the name comes from the target variable.
410 -- For a static one it is a formal of the enclosing init proc.
413 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
415 Make_Object_Declaration (Loc,
416 Defining_Identifier => Pref,
417 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
419 Make_String_Literal (Loc,
420 Strval => String_From_Name_Buffer)));
424 Make_Object_Renaming_Declaration (Loc,
425 Defining_Identifier => Pref,
426 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
427 Name => Make_Identifier (Loc, Name_uTask_Name)));
430 Indx := First_Index (A_Type);
431 Val := First (Expressions (Id_Ref));
433 for J in 1 .. Dims loop
434 T := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
438 Make_Object_Declaration (Loc,
439 Defining_Identifier => T,
440 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
442 Make_Attribute_Reference (Loc,
443 Attribute_Name => Name_Image,
445 New_Occurrence_Of (Etype (Indx), Loc),
446 Expressions => New_List (
447 New_Copy_Tree (Val)))));
453 Sum := Make_Integer_Literal (Loc, Dims + 1);
459 Make_Attribute_Reference (Loc,
460 Attribute_Name => Name_Length,
462 New_Occurrence_Of (Pref, Loc),
463 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
465 for J in 1 .. Dims loop
470 Make_Attribute_Reference (Loc,
471 Attribute_Name => Name_Length,
473 New_Occurrence_Of (Temps (J), Loc),
474 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
477 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
479 Set_Character_Literal_Name (Char_Code (Character'Pos ('(')));
482 Make_Assignment_Statement (Loc,
483 Name => Make_Indexed_Component (Loc,
484 Prefix => New_Occurrence_Of (Res, Loc),
485 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
487 Make_Character_Literal (Loc,
489 Char_Literal_Value =>
490 UI_From_Int (Character'Pos ('(')))));
493 Make_Assignment_Statement (Loc,
494 Name => New_Occurrence_Of (Pos, Loc),
497 Left_Opnd => New_Occurrence_Of (Pos, Loc),
498 Right_Opnd => Make_Integer_Literal (Loc, 1))));
500 for J in 1 .. Dims loop
503 Make_Assignment_Statement (Loc,
504 Name => Make_Slice (Loc,
505 Prefix => New_Occurrence_Of (Res, Loc),
508 Low_Bound => New_Occurrence_Of (Pos, Loc),
509 High_Bound => Make_Op_Subtract (Loc,
512 Left_Opnd => New_Occurrence_Of (Pos, Loc),
514 Make_Attribute_Reference (Loc,
515 Attribute_Name => Name_Length,
517 New_Occurrence_Of (Temps (J), Loc),
519 New_List (Make_Integer_Literal (Loc, 1)))),
520 Right_Opnd => Make_Integer_Literal (Loc, 1)))),
522 Expression => New_Occurrence_Of (Temps (J), Loc)));
526 Make_Assignment_Statement (Loc,
527 Name => New_Occurrence_Of (Pos, Loc),
530 Left_Opnd => New_Occurrence_Of (Pos, Loc),
532 Make_Attribute_Reference (Loc,
533 Attribute_Name => Name_Length,
534 Prefix => New_Occurrence_Of (Temps (J), Loc),
536 New_List (Make_Integer_Literal (Loc, 1))))));
538 Set_Character_Literal_Name (Char_Code (Character'Pos (',')));
541 Make_Assignment_Statement (Loc,
542 Name => Make_Indexed_Component (Loc,
543 Prefix => New_Occurrence_Of (Res, Loc),
544 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
546 Make_Character_Literal (Loc,
548 Char_Literal_Value =>
549 UI_From_Int (Character'Pos (',')))));
552 Make_Assignment_Statement (Loc,
553 Name => New_Occurrence_Of (Pos, Loc),
556 Left_Opnd => New_Occurrence_Of (Pos, Loc),
557 Right_Opnd => Make_Integer_Literal (Loc, 1))));
561 Set_Character_Literal_Name (Char_Code (Character'Pos (')')));
564 Make_Assignment_Statement (Loc,
565 Name => Make_Indexed_Component (Loc,
566 Prefix => New_Occurrence_Of (Res, Loc),
567 Expressions => New_List (New_Occurrence_Of (Len, Loc))),
569 Make_Character_Literal (Loc,
571 Char_Literal_Value =>
572 UI_From_Int (Character'Pos (')')))));
573 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
574 end Build_Task_Array_Image;
576 ----------------------------
577 -- Build_Task_Image_Decls --
578 ----------------------------
580 function Build_Task_Image_Decls
584 In_Init_Proc : Boolean := False) return List_Id
586 Decls : constant List_Id := New_List;
587 T_Id : Entity_Id := Empty;
589 Expr : Node_Id := Empty;
590 Fun : Node_Id := Empty;
591 Is_Dyn : constant Boolean :=
592 Nkind (Parent (Id_Ref)) = N_Assignment_Statement
594 Nkind (Expression (Parent (Id_Ref))) = N_Allocator;
597 -- If Discard_Names or No_Implicit_Heap_Allocations are in effect,
598 -- generate a dummy declaration only.
600 if Restriction_Active (No_Implicit_Heap_Allocations)
601 or else Global_Discard_Names
603 T_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('J'));
608 Make_Object_Declaration (Loc,
609 Defining_Identifier => T_Id,
610 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
612 Make_String_Literal (Loc,
613 Strval => String_From_Name_Buffer)));
616 if Nkind (Id_Ref) = N_Identifier
617 or else Nkind (Id_Ref) = N_Defining_Identifier
619 -- For a simple variable, the image of the task is built from
620 -- the name of the variable. To avoid possible conflict with
621 -- the anonymous type created for a single protected object,
622 -- add a numeric suffix.
625 Make_Defining_Identifier (Loc,
626 New_External_Name (Chars (Id_Ref), 'T', 1));
628 Get_Name_String (Chars (Id_Ref));
631 Make_String_Literal (Loc,
632 Strval => String_From_Name_Buffer);
634 elsif Nkind (Id_Ref) = N_Selected_Component then
636 Make_Defining_Identifier (Loc,
637 New_External_Name (Chars (Selector_Name (Id_Ref)), 'T'));
638 Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn);
640 elsif Nkind (Id_Ref) = N_Indexed_Component then
642 Make_Defining_Identifier (Loc,
643 New_External_Name (Chars (A_Type), 'N'));
645 Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn);
649 if Present (Fun) then
651 Expr := Make_Function_Call (Loc,
652 Name => New_Occurrence_Of (Defining_Entity (Fun), Loc));
654 if not In_Init_Proc and then VM_Target = No_VM then
655 Set_Uses_Sec_Stack (Defining_Entity (Fun));
659 Decl := Make_Object_Declaration (Loc,
660 Defining_Identifier => T_Id,
661 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
662 Constant_Present => True,
665 Append (Decl, Decls);
667 end Build_Task_Image_Decls;
669 -------------------------------
670 -- Build_Task_Image_Function --
671 -------------------------------
673 function Build_Task_Image_Function
677 Res : Entity_Id) return Node_Id
683 Make_Return_Statement (Loc,
684 Expression => New_Occurrence_Of (Res, Loc)));
686 Spec := Make_Function_Specification (Loc,
687 Defining_Unit_Name =>
688 Make_Defining_Identifier (Loc, New_Internal_Name ('F')),
689 Result_Definition => New_Occurrence_Of (Standard_String, Loc));
691 -- Calls to 'Image use the secondary stack, which must be cleaned
692 -- up after the task name is built.
694 return Make_Subprogram_Body (Loc,
695 Specification => Spec,
696 Declarations => Decls,
697 Handled_Statement_Sequence =>
698 Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats));
699 end Build_Task_Image_Function;
701 -----------------------------
702 -- Build_Task_Image_Prefix --
703 -----------------------------
705 procedure Build_Task_Image_Prefix
712 Decls : in out List_Id;
713 Stats : in out List_Id)
716 Len := Make_Defining_Identifier (Loc, New_Internal_Name ('L'));
719 Make_Object_Declaration (Loc,
720 Defining_Identifier => Len,
721 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
724 Res := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
727 Make_Object_Declaration (Loc,
728 Defining_Identifier => Res,
730 Make_Subtype_Indication (Loc,
731 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
733 Make_Index_Or_Discriminant_Constraint (Loc,
737 Low_Bound => Make_Integer_Literal (Loc, 1),
738 High_Bound => New_Occurrence_Of (Len, Loc)))))));
740 Pos := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
743 Make_Object_Declaration (Loc,
744 Defining_Identifier => Pos,
745 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc)));
747 -- Pos := Prefix'Length;
750 Make_Assignment_Statement (Loc,
751 Name => New_Occurrence_Of (Pos, Loc),
753 Make_Attribute_Reference (Loc,
754 Attribute_Name => Name_Length,
755 Prefix => New_Occurrence_Of (Prefix, Loc),
757 New_List (Make_Integer_Literal (Loc, 1)))));
759 -- Res (1 .. Pos) := Prefix;
762 Make_Assignment_Statement (Loc,
763 Name => Make_Slice (Loc,
764 Prefix => New_Occurrence_Of (Res, Loc),
767 Low_Bound => Make_Integer_Literal (Loc, 1),
768 High_Bound => New_Occurrence_Of (Pos, Loc))),
770 Expression => New_Occurrence_Of (Prefix, Loc)));
773 Make_Assignment_Statement (Loc,
774 Name => New_Occurrence_Of (Pos, Loc),
777 Left_Opnd => New_Occurrence_Of (Pos, Loc),
778 Right_Opnd => Make_Integer_Literal (Loc, 1))));
779 end Build_Task_Image_Prefix;
781 -----------------------------
782 -- Build_Task_Record_Image --
783 -----------------------------
785 function Build_Task_Record_Image
788 Dyn : Boolean := False) return Node_Id
791 -- Total length of generated name
797 -- String to hold result
800 -- Name of enclosing variable, prefix of resulting name
803 -- Expression to compute total size of string
806 -- Entity for selector name
808 Decls : List_Id := New_List;
809 Stats : List_Id := New_List;
812 Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
814 -- For a dynamic task, the name comes from the target variable.
815 -- For a static one it is a formal of the enclosing init proc.
818 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
820 Make_Object_Declaration (Loc,
821 Defining_Identifier => Pref,
822 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
824 Make_String_Literal (Loc,
825 Strval => String_From_Name_Buffer)));
829 Make_Object_Renaming_Declaration (Loc,
830 Defining_Identifier => Pref,
831 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
832 Name => Make_Identifier (Loc, Name_uTask_Name)));
835 Sel := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
837 Get_Name_String (Chars (Selector_Name (Id_Ref)));
840 Make_Object_Declaration (Loc,
841 Defining_Identifier => Sel,
842 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
844 Make_String_Literal (Loc,
845 Strval => String_From_Name_Buffer)));
847 Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1));
853 Make_Attribute_Reference (Loc,
854 Attribute_Name => Name_Length,
856 New_Occurrence_Of (Pref, Loc),
857 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
859 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
861 Set_Character_Literal_Name (Char_Code (Character'Pos ('.')));
866 Make_Assignment_Statement (Loc,
867 Name => Make_Indexed_Component (Loc,
868 Prefix => New_Occurrence_Of (Res, Loc),
869 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
871 Make_Character_Literal (Loc,
873 Char_Literal_Value =>
874 UI_From_Int (Character'Pos ('.')))));
877 Make_Assignment_Statement (Loc,
878 Name => New_Occurrence_Of (Pos, Loc),
881 Left_Opnd => New_Occurrence_Of (Pos, Loc),
882 Right_Opnd => Make_Integer_Literal (Loc, 1))));
884 -- Res (Pos .. Len) := Selector;
887 Make_Assignment_Statement (Loc,
888 Name => Make_Slice (Loc,
889 Prefix => New_Occurrence_Of (Res, Loc),
892 Low_Bound => New_Occurrence_Of (Pos, Loc),
893 High_Bound => New_Occurrence_Of (Len, Loc))),
894 Expression => New_Occurrence_Of (Sel, Loc)));
896 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
897 end Build_Task_Record_Image;
899 ----------------------------------
900 -- Component_May_Be_Bit_Aligned --
901 ----------------------------------
903 function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is
905 -- If no component clause, then everything is fine, since the
906 -- back end never bit-misaligns by default, even if there is
907 -- a pragma Packed for the record.
909 if No (Component_Clause (Comp)) then
913 -- It is only array and record types that cause trouble
915 if not Is_Record_Type (Etype (Comp))
916 and then not Is_Array_Type (Etype (Comp))
920 -- If we know that we have a small (64 bits or less) record
921 -- or bit-packed array, then everything is fine, since the
922 -- back end can handle these cases correctly.
924 elsif Esize (Comp) <= 64
925 and then (Is_Record_Type (Etype (Comp))
926 or else Is_Bit_Packed_Array (Etype (Comp)))
930 -- Otherwise if the component is not byte aligned, we
931 -- know we have the nasty unaligned case.
933 elsif Normalized_First_Bit (Comp) /= Uint_0
934 or else Esize (Comp) mod System_Storage_Unit /= Uint_0
938 -- If we are large and byte aligned, then OK at this level
943 end Component_May_Be_Bit_Aligned;
945 -------------------------------
946 -- Convert_To_Actual_Subtype --
947 -------------------------------
949 procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is
953 Act_ST := Get_Actual_Subtype (Exp);
955 if Act_ST = Etype (Exp) then
960 Convert_To (Act_ST, Relocate_Node (Exp)));
961 Analyze_And_Resolve (Exp, Act_ST);
963 end Convert_To_Actual_Subtype;
965 -----------------------------------
966 -- Current_Sem_Unit_Declarations --
967 -----------------------------------
969 function Current_Sem_Unit_Declarations return List_Id is
970 U : Node_Id := Unit (Cunit (Current_Sem_Unit));
974 -- If the current unit is a package body, locate the visible
975 -- declarations of the package spec.
977 if Nkind (U) = N_Package_Body then
978 U := Unit (Library_Unit (Cunit (Current_Sem_Unit)));
981 if Nkind (U) = N_Package_Declaration then
982 U := Specification (U);
983 Decls := Visible_Declarations (U);
987 Set_Visible_Declarations (U, Decls);
991 Decls := Declarations (U);
995 Set_Declarations (U, Decls);
1000 end Current_Sem_Unit_Declarations;
1002 -----------------------
1003 -- Duplicate_Subexpr --
1004 -----------------------
1006 function Duplicate_Subexpr
1008 Name_Req : Boolean := False) return Node_Id
1011 Remove_Side_Effects (Exp, Name_Req);
1012 return New_Copy_Tree (Exp);
1013 end Duplicate_Subexpr;
1015 ---------------------------------
1016 -- Duplicate_Subexpr_No_Checks --
1017 ---------------------------------
1019 function Duplicate_Subexpr_No_Checks
1021 Name_Req : Boolean := False) return Node_Id
1026 Remove_Side_Effects (Exp, Name_Req);
1027 New_Exp := New_Copy_Tree (Exp);
1028 Remove_Checks (New_Exp);
1030 end Duplicate_Subexpr_No_Checks;
1032 -----------------------------------
1033 -- Duplicate_Subexpr_Move_Checks --
1034 -----------------------------------
1036 function Duplicate_Subexpr_Move_Checks
1038 Name_Req : Boolean := False) return Node_Id
1043 Remove_Side_Effects (Exp, Name_Req);
1044 New_Exp := New_Copy_Tree (Exp);
1045 Remove_Checks (Exp);
1047 end Duplicate_Subexpr_Move_Checks;
1049 --------------------
1050 -- Ensure_Defined --
1051 --------------------
1053 procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is
1058 if Is_Itype (Typ) then
1059 IR := Make_Itype_Reference (Sloc (N));
1060 Set_Itype (IR, Typ);
1062 if not In_Open_Scopes (Scope (Typ))
1063 and then Is_Subprogram (Current_Scope)
1064 and then Scope (Current_Scope) /= Standard_Standard
1066 -- Insert node in front of subprogram, to avoid scope anomalies
1071 and then Nkind (P) /= N_Subprogram_Body
1077 Insert_Action (P, IR);
1079 Insert_Action (N, IR);
1083 Insert_Action (N, IR);
1088 ---------------------
1089 -- Evolve_And_Then --
1090 ---------------------
1092 procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is
1098 Make_And_Then (Sloc (Cond1),
1100 Right_Opnd => Cond1);
1102 end Evolve_And_Then;
1104 --------------------
1105 -- Evolve_Or_Else --
1106 --------------------
1108 procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is
1114 Make_Or_Else (Sloc (Cond1),
1116 Right_Opnd => Cond1);
1120 ------------------------------
1121 -- Expand_Subtype_From_Expr --
1122 ------------------------------
1124 -- This function is applicable for both static and dynamic allocation of
1125 -- objects which are constrained by an initial expression. Basically it
1126 -- transforms an unconstrained subtype indication into a constrained one.
1127 -- The expression may also be transformed in certain cases in order to
1128 -- avoid multiple evaluation. In the static allocation case, the general
1133 -- is transformed into
1135 -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr;
1137 -- Here are the main cases :
1139 -- <if Expr is a Slice>
1140 -- Val : T ([Index_Subtype (Expr)]) := Expr;
1142 -- <elsif Expr is a String Literal>
1143 -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
1145 -- <elsif Expr is Constrained>
1146 -- subtype T is Type_Of_Expr
1149 -- <elsif Expr is an entity_name>
1150 -- Val : T (constraints taken from Expr) := Expr;
1153 -- type Axxx is access all T;
1154 -- Rval : Axxx := Expr'ref;
1155 -- Val : T (constraints taken from Rval) := Rval.all;
1157 -- ??? note: when the Expression is allocated in the secondary stack
1158 -- we could use it directly instead of copying it by declaring
1159 -- Val : T (...) renames Rval.all
1161 procedure Expand_Subtype_From_Expr
1163 Unc_Type : Entity_Id;
1164 Subtype_Indic : Node_Id;
1167 Loc : constant Source_Ptr := Sloc (N);
1168 Exp_Typ : constant Entity_Id := Etype (Exp);
1172 -- In general we cannot build the subtype if expansion is disabled,
1173 -- because internal entities may not have been defined. However, to
1174 -- avoid some cascaded errors, we try to continue when the expression
1175 -- is an array (or string), because it is safe to compute the bounds.
1176 -- It is in fact required to do so even in a generic context, because
1177 -- there may be constants that depend on bounds of string literal.
1179 if not Expander_Active
1180 and then (No (Etype (Exp))
1181 or else Base_Type (Etype (Exp)) /= Standard_String)
1186 if Nkind (Exp) = N_Slice then
1188 Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ));
1191 Rewrite (Subtype_Indic,
1192 Make_Subtype_Indication (Loc,
1193 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1195 Make_Index_Or_Discriminant_Constraint (Loc,
1196 Constraints => New_List
1197 (New_Reference_To (Slice_Type, Loc)))));
1199 -- This subtype indication may be used later for contraint checks
1200 -- we better make sure that if a variable was used as a bound of
1201 -- of the original slice, its value is frozen.
1203 Force_Evaluation (Low_Bound (Scalar_Range (Slice_Type)));
1204 Force_Evaluation (High_Bound (Scalar_Range (Slice_Type)));
1207 elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then
1208 Rewrite (Subtype_Indic,
1209 Make_Subtype_Indication (Loc,
1210 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1212 Make_Index_Or_Discriminant_Constraint (Loc,
1213 Constraints => New_List (
1214 Make_Literal_Range (Loc,
1215 Literal_Typ => Exp_Typ)))));
1217 elsif Is_Constrained (Exp_Typ)
1218 and then not Is_Class_Wide_Type (Unc_Type)
1220 if Is_Itype (Exp_Typ) then
1222 -- Within an initialization procedure, a selected component
1223 -- denotes a component of the enclosing record, and it appears
1224 -- as an actual in a call to its own initialization procedure.
1225 -- If this component depends on the outer discriminant, we must
1226 -- generate the proper actual subtype for it.
1228 if Nkind (Exp) = N_Selected_Component
1229 and then Within_Init_Proc
1232 Decl : constant Node_Id :=
1233 Build_Actual_Subtype_Of_Component (Exp_Typ, Exp);
1235 if Present (Decl) then
1236 Insert_Action (N, Decl);
1237 T := Defining_Identifier (Decl);
1243 -- No need to generate a new one (new what???)
1251 Make_Defining_Identifier (Loc,
1252 Chars => New_Internal_Name ('T'));
1255 Make_Subtype_Declaration (Loc,
1256 Defining_Identifier => T,
1257 Subtype_Indication => New_Reference_To (Exp_Typ, Loc)));
1259 -- This type is marked as an itype even though it has an
1260 -- explicit declaration because otherwise it can be marked
1261 -- with Is_Generic_Actual_Type and generate spurious errors.
1262 -- (see sem_ch8.Analyze_Package_Renaming and sem_type.covers)
1265 Set_Associated_Node_For_Itype (T, Exp);
1268 Rewrite (Subtype_Indic, New_Reference_To (T, Loc));
1270 -- nothing needs to be done for private types with unknown discriminants
1271 -- if the underlying type is not an unconstrained composite type.
1273 elsif Is_Private_Type (Unc_Type)
1274 and then Has_Unknown_Discriminants (Unc_Type)
1275 and then (not Is_Composite_Type (Underlying_Type (Unc_Type))
1276 or else Is_Constrained (Underlying_Type (Unc_Type)))
1280 -- Nothing to be done for derived types with unknown discriminants if
1281 -- the parent type also has unknown discriminants.
1283 elsif Is_Record_Type (Unc_Type)
1284 and then not Is_Class_Wide_Type (Unc_Type)
1285 and then Has_Unknown_Discriminants (Unc_Type)
1286 and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type))
1290 -- In Ada95, Nothing to be done if the type of the expression is
1291 -- limited, because in this case the expression cannot be copied,
1292 -- and its use can only be by reference.
1294 -- In Ada2005, the context can be an object declaration whose expression
1295 -- is a function that returns in place. If the nominal subtype has
1296 -- unknown discriminants, the call still provides constraints on the
1297 -- object, and we have to create an actual subtype from it.
1299 -- If the type is class-wide, the expression is dynamically tagged and
1300 -- we do not create an actual subtype either. Ditto for an interface.
1302 elsif Is_Limited_Type (Exp_Typ)
1304 (Is_Class_Wide_Type (Exp_Typ)
1305 or else Is_Interface (Exp_Typ)
1306 or else not Has_Unknown_Discriminants (Exp_Typ)
1307 or else not Is_Composite_Type (Unc_Type))
1311 -- For limited interfaces, nothing to be done
1313 -- This branch may be redundant once the limited interface issue is
1316 elsif Is_Interface (Exp_Typ)
1317 and then Is_Limited_Interface (Exp_Typ)
1322 Remove_Side_Effects (Exp);
1323 Rewrite (Subtype_Indic,
1324 Make_Subtype_From_Expr (Exp, Unc_Type));
1326 end Expand_Subtype_From_Expr;
1328 ------------------------
1329 -- Find_Interface_ADT --
1330 ------------------------
1332 function Find_Interface_ADT
1334 Iface : Entity_Id) return Entity_Id
1337 Found : Boolean := False;
1338 Typ : Entity_Id := T;
1340 procedure Find_Secondary_Table (Typ : Entity_Id);
1341 -- Internal subprogram used to recursively climb to the ancestors
1343 --------------------------
1344 -- Find_Secondary_Table --
1345 --------------------------
1347 procedure Find_Secondary_Table (Typ : Entity_Id) is
1352 pragma Assert (Typ /= Iface);
1354 -- Climb to the ancestor (if any) handling synchronized interface
1355 -- derivations and private types
1357 if Is_Concurrent_Record_Type (Typ) then
1359 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1362 if Is_Non_Empty_List (Iface_List) then
1363 Find_Secondary_Table (Etype (First (Iface_List)));
1367 elsif Present (Full_View (Etype (Typ))) then
1368 if Full_View (Etype (Typ)) /= Typ then
1369 Find_Secondary_Table (Full_View (Etype (Typ)));
1372 elsif Etype (Typ) /= Typ then
1373 Find_Secondary_Table (Etype (Typ));
1376 -- Traverse the list of interfaces implemented by the type
1379 and then Present (Abstract_Interfaces (Typ))
1380 and then not Is_Empty_Elmt_List (Abstract_Interfaces (Typ))
1382 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1383 while Present (AI_Elmt) loop
1384 AI := Node (AI_Elmt);
1386 if AI = Iface or else Is_Ancestor (Iface, AI) then
1392 Next_Elmt (AI_Elmt);
1395 end Find_Secondary_Table;
1397 -- Start of processing for Find_Interface_ADT
1400 pragma Assert (Is_Interface (Iface));
1402 -- Handle private types
1404 if Has_Private_Declaration (Typ)
1405 and then Present (Full_View (Typ))
1407 Typ := Full_View (Typ);
1410 -- Handle access types
1412 if Is_Access_Type (Typ) then
1413 Typ := Directly_Designated_Type (Typ);
1416 -- Handle task and protected types implementing interfaces
1418 if Is_Concurrent_Type (Typ) then
1419 Typ := Corresponding_Record_Type (Typ);
1423 (not Is_Class_Wide_Type (Typ)
1424 and then Ekind (Typ) /= E_Incomplete_Type);
1426 ADT := Next_Elmt (First_Elmt (Access_Disp_Table (Typ)));
1427 pragma Assert (Present (Node (ADT)));
1428 Find_Secondary_Table (Typ);
1429 pragma Assert (Found);
1431 end Find_Interface_ADT;
1433 ------------------------
1434 -- Find_Interface_Tag --
1435 ------------------------
1437 function Find_Interface_Tag
1439 Iface : Entity_Id) return Entity_Id
1442 Found : Boolean := False;
1443 Typ : Entity_Id := T;
1445 Is_Primary_Tag : Boolean := False;
1447 Is_Sync_Typ : Boolean := False;
1448 -- In case of non concurrent-record-types each parent-type has the
1449 -- tags associated with the interface types that are not implemented
1450 -- by the ancestors; concurrent-record-types have their whole list of
1451 -- interface tags (and this case requires some special management).
1453 procedure Find_Tag (Typ : Entity_Id);
1454 -- Internal subprogram used to recursively climb to the ancestors
1460 procedure Find_Tag (Typ : Entity_Id) is
1465 -- Check if the interface is an immediate ancestor of the type and
1466 -- therefore shares the main tag.
1470 Is_Primary_Tag := True;
1473 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1474 AI_Tag := First_Tag_Component (Typ);
1481 -- Handle synchronized interface derivations
1483 if Is_Concurrent_Record_Type (Typ) then
1485 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1487 if Is_Non_Empty_List (Iface_List) then
1488 Find_Tag (Etype (First (Iface_List)));
1492 -- Climb to the root type handling private types
1494 elsif Present (Full_View (Etype (Typ))) then
1495 if Full_View (Etype (Typ)) /= Typ then
1496 Find_Tag (Full_View (Etype (Typ)));
1499 elsif Etype (Typ) /= Typ then
1500 Find_Tag (Etype (Typ));
1503 -- Traverse the list of interfaces implemented by the type
1506 and then Present (Abstract_Interfaces (Typ))
1507 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1509 -- Skip the tag associated with the primary table
1511 if not Is_Sync_Typ then
1513 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1514 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1515 pragma Assert (Present (AI_Tag));
1518 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1519 while Present (AI_Elmt) loop
1520 AI := Node (AI_Elmt);
1522 if AI = Iface or else Is_Ancestor (Iface, AI) then
1527 AI_Tag := Next_Tag_Component (AI_Tag);
1528 Next_Elmt (AI_Elmt);
1533 -- Start of processing for Find_Interface_Tag
1536 pragma Assert (Is_Interface (Iface));
1538 -- Handle private types
1540 if Has_Private_Declaration (Typ)
1541 and then Present (Full_View (Typ))
1543 Typ := Full_View (Typ);
1546 -- Handle access types
1548 if Is_Access_Type (Typ) then
1549 Typ := Directly_Designated_Type (Typ);
1552 -- Handle task and protected types implementing interfaces
1554 if Is_Concurrent_Type (Typ) then
1555 Typ := Corresponding_Record_Type (Typ);
1558 if Is_Class_Wide_Type (Typ) then
1562 -- Handle entities from the limited view
1564 if Ekind (Typ) = E_Incomplete_Type then
1565 pragma Assert (Present (Non_Limited_View (Typ)));
1566 Typ := Non_Limited_View (Typ);
1569 if not Is_Concurrent_Record_Type (Typ) then
1571 pragma Assert (Found);
1574 -- Concurrent record types
1577 Is_Sync_Typ := True;
1578 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1580 pragma Assert (Found);
1582 if Is_Primary_Tag then
1583 return First_Tag_Component (Typ);
1588 end Find_Interface_Tag;
1590 --------------------
1591 -- Find_Interface --
1592 --------------------
1594 function Find_Interface
1596 Comp : Entity_Id) return Entity_Id
1599 Found : Boolean := False;
1601 Typ : Entity_Id := T;
1603 Is_Sync_Typ : Boolean := False;
1604 -- In case of non concurrent-record-types each parent-type has the
1605 -- tags associated with the interface types that are not implemented
1606 -- by the ancestors; concurrent-record-types have their whole list of
1607 -- interface tags (and this case requires some special management).
1609 procedure Find_Iface (Typ : Entity_Id);
1610 -- Internal subprogram used to recursively climb to the ancestors
1616 procedure Find_Iface (Typ : Entity_Id) is
1620 -- Climb to the root type
1622 -- Handle sychronized interface derivations
1624 if Is_Concurrent_Record_Type (Typ) then
1626 Iface_List : constant List_Id := Abstract_Interface_List (Typ);
1628 if Is_Non_Empty_List (Iface_List) then
1629 Find_Iface (Etype (First (Iface_List)));
1633 -- Handle the common case
1635 elsif Etype (Typ) /= Typ then
1636 pragma Assert (not Present (Full_View (Etype (Typ))));
1637 Find_Iface (Etype (Typ));
1640 -- Traverse the list of interfaces implemented by the type
1643 and then Present (Abstract_Interfaces (Typ))
1644 and then not (Is_Empty_Elmt_List (Abstract_Interfaces (Typ)))
1646 -- Skip the tag associated with the primary table
1648 if not Is_Sync_Typ then
1650 (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1651 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1652 pragma Assert (Present (AI_Tag));
1655 AI_Elmt := First_Elmt (Abstract_Interfaces (Typ));
1656 while Present (AI_Elmt) loop
1657 if AI_Tag = Comp then
1658 Iface := Node (AI_Elmt);
1663 AI_Tag := Next_Tag_Component (AI_Tag);
1664 Next_Elmt (AI_Elmt);
1669 -- Start of processing for Find_Interface
1672 -- Handle private types
1674 if Has_Private_Declaration (Typ)
1675 and then Present (Full_View (Typ))
1677 Typ := Full_View (Typ);
1680 -- Handle access types
1682 if Is_Access_Type (Typ) then
1683 Typ := Directly_Designated_Type (Typ);
1686 -- Handle task and protected types implementing interfaces
1688 if Is_Concurrent_Type (Typ) then
1689 Typ := Corresponding_Record_Type (Typ);
1692 if Is_Class_Wide_Type (Typ) then
1696 -- Handle entities from the limited view
1698 if Ekind (Typ) = E_Incomplete_Type then
1699 pragma Assert (Present (Non_Limited_View (Typ)));
1700 Typ := Non_Limited_View (Typ);
1703 if Is_Concurrent_Record_Type (Typ) then
1704 Is_Sync_Typ := True;
1705 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1709 pragma Assert (Found);
1717 function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is
1719 Typ : Entity_Id := T;
1723 if Is_Class_Wide_Type (Typ) then
1724 Typ := Root_Type (Typ);
1727 Typ := Underlying_Type (Typ);
1729 -- Loop through primitive operations
1731 Prim := First_Elmt (Primitive_Operations (Typ));
1732 while Present (Prim) loop
1735 -- We can retrieve primitive operations by name if it is an internal
1736 -- name. For equality we must check that both of its operands have
1737 -- the same type, to avoid confusion with user-defined equalities
1738 -- than may have a non-symmetric signature.
1740 exit when Chars (Op) = Name
1743 or else Etype (First_Entity (Op)) = Etype (Last_Entity (Op)));
1746 pragma Assert (Present (Prim));
1756 function Find_Prim_Op
1758 Name : TSS_Name_Type) return Entity_Id
1761 Typ : Entity_Id := T;
1764 if Is_Class_Wide_Type (Typ) then
1765 Typ := Root_Type (Typ);
1768 Typ := Underlying_Type (Typ);
1770 Prim := First_Elmt (Primitive_Operations (Typ));
1771 while not Is_TSS (Node (Prim), Name) loop
1773 pragma Assert (Present (Prim));
1779 ----------------------
1780 -- Force_Evaluation --
1781 ----------------------
1783 procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is
1785 Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True);
1786 end Force_Evaluation;
1788 ------------------------
1789 -- Generate_Poll_Call --
1790 ------------------------
1792 procedure Generate_Poll_Call (N : Node_Id) is
1794 -- No poll call if polling not active
1796 if not Polling_Required then
1799 -- Otherwise generate require poll call
1802 Insert_Before_And_Analyze (N,
1803 Make_Procedure_Call_Statement (Sloc (N),
1804 Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N))));
1806 end Generate_Poll_Call;
1808 ---------------------------------
1809 -- Get_Current_Value_Condition --
1810 ---------------------------------
1812 -- Note: the implementation of this procedure is very closely tied to the
1813 -- implementation of Set_Current_Value_Condition. In the Get procedure, we
1814 -- interpret Current_Value fields set by the Set procedure, so the two
1815 -- procedures need to be closely coordinated.
1817 procedure Get_Current_Value_Condition
1822 Loc : constant Source_Ptr := Sloc (Var);
1823 Ent : constant Entity_Id := Entity (Var);
1825 procedure Process_Current_Value_Condition
1828 -- N is an expression which holds either True (S = True) or False (S =
1829 -- False) in the condition. This procedure digs out the expression and
1830 -- if it refers to Ent, sets Op and Val appropriately.
1832 -------------------------------------
1833 -- Process_Current_Value_Condition --
1834 -------------------------------------
1836 procedure Process_Current_Value_Condition
1847 -- Deal with NOT operators, inverting sense
1849 while Nkind (Cond) = N_Op_Not loop
1850 Cond := Right_Opnd (Cond);
1854 -- Deal with AND THEN and AND cases
1856 if Nkind (Cond) = N_And_Then
1857 or else Nkind (Cond) = N_Op_And
1859 -- Don't ever try to invert a condition that is of the form
1860 -- of an AND or AND THEN (since we are not doing sufficiently
1861 -- general processing to allow this).
1863 if Sens = False then
1869 -- Recursively process AND and AND THEN branches
1871 Process_Current_Value_Condition (Left_Opnd (Cond), True);
1873 if Op /= N_Empty then
1877 Process_Current_Value_Condition (Right_Opnd (Cond), True);
1880 -- Case of relational operator
1882 elsif Nkind (Cond) in N_Op_Compare then
1885 -- Invert sense of test if inverted test
1887 if Sens = False then
1889 when N_Op_Eq => Op := N_Op_Ne;
1890 when N_Op_Ne => Op := N_Op_Eq;
1891 when N_Op_Lt => Op := N_Op_Ge;
1892 when N_Op_Gt => Op := N_Op_Le;
1893 when N_Op_Le => Op := N_Op_Gt;
1894 when N_Op_Ge => Op := N_Op_Lt;
1895 when others => raise Program_Error;
1899 -- Case of entity op value
1901 if Is_Entity_Name (Left_Opnd (Cond))
1902 and then Ent = Entity (Left_Opnd (Cond))
1903 and then Compile_Time_Known_Value (Right_Opnd (Cond))
1905 Val := Right_Opnd (Cond);
1907 -- Case of value op entity
1909 elsif Is_Entity_Name (Right_Opnd (Cond))
1910 and then Ent = Entity (Right_Opnd (Cond))
1911 and then Compile_Time_Known_Value (Left_Opnd (Cond))
1913 Val := Left_Opnd (Cond);
1915 -- We are effectively swapping operands
1918 when N_Op_Eq => null;
1919 when N_Op_Ne => null;
1920 when N_Op_Lt => Op := N_Op_Gt;
1921 when N_Op_Gt => Op := N_Op_Lt;
1922 when N_Op_Le => Op := N_Op_Ge;
1923 when N_Op_Ge => Op := N_Op_Le;
1924 when others => raise Program_Error;
1933 -- Case of Boolean variable reference, return as though the
1934 -- reference had said var = True.
1937 if Is_Entity_Name (Cond)
1938 and then Ent = Entity (Cond)
1940 Val := New_Occurrence_Of (Standard_True, Sloc (Cond));
1942 if Sens = False then
1949 end Process_Current_Value_Condition;
1951 -- Start of processing for Get_Current_Value_Condition
1957 -- Immediate return, nothing doing, if this is not an object
1959 if Ekind (Ent) not in Object_Kind then
1963 -- Otherwise examine current value
1966 CV : constant Node_Id := Current_Value (Ent);
1971 -- If statement. Condition is known true in THEN section, known False
1972 -- in any ELSIF or ELSE part, and unknown outside the IF statement.
1974 if Nkind (CV) = N_If_Statement then
1976 -- Before start of IF statement
1978 if Loc < Sloc (CV) then
1981 -- After end of IF statement
1983 elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
1987 -- At this stage we know that we are within the IF statement, but
1988 -- unfortunately, the tree does not record the SLOC of the ELSE so
1989 -- we cannot use a simple SLOC comparison to distinguish between
1990 -- the then/else statements, so we have to climb the tree.
1997 while Parent (N) /= CV loop
2000 -- If we fall off the top of the tree, then that's odd, but
2001 -- perhaps it could occur in some error situation, and the
2002 -- safest response is simply to assume that the outcome of
2003 -- the condition is unknown. No point in bombing during an
2004 -- attempt to optimize things.
2011 -- Now we have N pointing to a node whose parent is the IF
2012 -- statement in question, so now we can tell if we are within
2013 -- the THEN statements.
2015 if Is_List_Member (N)
2016 and then List_Containing (N) = Then_Statements (CV)
2020 -- If the variable reference does not come from source, we
2021 -- cannot reliably tell whether it appears in the else part.
2022 -- In particular, if if appears in generated code for a node
2023 -- that requires finalization, it may be attached to a list
2024 -- that has not been yet inserted into the code. For now,
2025 -- treat it as unknown.
2027 elsif not Comes_From_Source (N) then
2030 -- Otherwise we must be in ELSIF or ELSE part
2037 -- ELSIF part. Condition is known true within the referenced
2038 -- ELSIF, known False in any subsequent ELSIF or ELSE part, and
2039 -- unknown before the ELSE part or after the IF statement.
2041 elsif Nkind (CV) = N_Elsif_Part then
2044 -- Before start of ELSIF part
2046 if Loc < Sloc (CV) then
2049 -- After end of IF statement
2051 elsif Loc >= Sloc (Stm) +
2052 Text_Ptr (UI_To_Int (End_Span (Stm)))
2057 -- Again we lack the SLOC of the ELSE, so we need to climb the
2058 -- tree to see if we are within the ELSIF part in question.
2065 while Parent (N) /= Stm loop
2068 -- If we fall off the top of the tree, then that's odd, but
2069 -- perhaps it could occur in some error situation, and the
2070 -- safest response is simply to assume that the outcome of
2071 -- the condition is unknown. No point in bombing during an
2072 -- attempt to optimize things.
2079 -- Now we have N pointing to a node whose parent is the IF
2080 -- statement in question, so see if is the ELSIF part we want.
2081 -- the THEN statements.
2086 -- Otherwise we must be in susbequent ELSIF or ELSE part
2093 -- Iteration scheme of while loop. The condition is known to be
2094 -- true within the body of the loop.
2096 elsif Nkind (CV) = N_Iteration_Scheme then
2098 Loop_Stmt : constant Node_Id := Parent (CV);
2101 -- Before start of body of loop
2103 if Loc < Sloc (Loop_Stmt) then
2106 -- After end of LOOP statement
2108 elsif Loc >= Sloc (End_Label (Loop_Stmt)) then
2111 -- We are within the body of the loop
2118 -- All other cases of Current_Value settings
2124 -- If we fall through here, then we have a reportable condition, Sens
2125 -- is True if the condition is true and False if it needs inverting.
2127 Process_Current_Value_Condition (Condition (CV), Sens);
2129 end Get_Current_Value_Condition;
2131 ---------------------------------
2132 -- Has_Controlled_Coextensions --
2133 ---------------------------------
2135 function Has_Controlled_Coextensions (Typ : Entity_Id) return Boolean is
2140 -- Only consider record types
2142 if Ekind (Typ) /= E_Record_Type
2143 and then Ekind (Typ) /= E_Record_Subtype
2148 if Has_Discriminants (Typ) then
2149 Discr := First_Discriminant (Typ);
2150 while Present (Discr) loop
2151 D_Typ := Etype (Discr);
2153 if Ekind (D_Typ) = E_Anonymous_Access_Type
2155 (Is_Controlled (Directly_Designated_Type (D_Typ))
2157 Is_Concurrent_Type (Directly_Designated_Type (D_Typ)))
2162 Next_Discriminant (Discr);
2167 end Has_Controlled_Coextensions;
2169 --------------------
2170 -- Homonym_Number --
2171 --------------------
2173 function Homonym_Number (Subp : Entity_Id) return Nat is
2179 Hom := Homonym (Subp);
2180 while Present (Hom) loop
2181 if Scope (Hom) = Scope (Subp) then
2185 Hom := Homonym (Hom);
2191 ------------------------------
2192 -- In_Unconditional_Context --
2193 ------------------------------
2195 function In_Unconditional_Context (Node : Node_Id) return Boolean is
2200 while Present (P) loop
2202 when N_Subprogram_Body =>
2205 when N_If_Statement =>
2208 when N_Loop_Statement =>
2211 when N_Case_Statement =>
2220 end In_Unconditional_Context;
2226 procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is
2228 if Present (Ins_Action) then
2229 Insert_Actions (Assoc_Node, New_List (Ins_Action));
2233 -- Version with check(s) suppressed
2235 procedure Insert_Action
2236 (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id)
2239 Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress);
2242 --------------------
2243 -- Insert_Actions --
2244 --------------------
2246 procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is
2250 Wrapped_Node : Node_Id := Empty;
2253 if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
2257 -- Ignore insert of actions from inside default expression in the
2258 -- special preliminary analyze mode. Any insertions at this point
2259 -- have no relevance, since we are only doing the analyze to freeze
2260 -- the types of any static expressions. See section "Handling of
2261 -- Default Expressions" in the spec of package Sem for further details.
2263 if In_Default_Expression then
2267 -- If the action derives from stuff inside a record, then the actions
2268 -- are attached to the current scope, to be inserted and analyzed on
2269 -- exit from the scope. The reason for this is that we may also
2270 -- be generating freeze actions at the same time, and they must
2271 -- eventually be elaborated in the correct order.
2273 if Is_Record_Type (Current_Scope)
2274 and then not Is_Frozen (Current_Scope)
2276 if No (Scope_Stack.Table
2277 (Scope_Stack.Last).Pending_Freeze_Actions)
2279 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
2284 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
2290 -- We now intend to climb up the tree to find the right point to
2291 -- insert the actions. We start at Assoc_Node, unless this node is
2292 -- a subexpression in which case we start with its parent. We do this
2293 -- for two reasons. First it speeds things up. Second, if Assoc_Node
2294 -- is itself one of the special nodes like N_And_Then, then we assume
2295 -- that an initial request to insert actions for such a node does not
2296 -- expect the actions to get deposited in the node for later handling
2297 -- when the node is expanded, since clearly the node is being dealt
2298 -- with by the caller. Note that in the subexpression case, N is
2299 -- always the child we came from.
2301 -- N_Raise_xxx_Error is an annoying special case, it is a statement
2302 -- if it has type Standard_Void_Type, and a subexpression otherwise.
2303 -- otherwise. Procedure attribute references are also statements.
2305 if Nkind (Assoc_Node) in N_Subexpr
2306 and then (Nkind (Assoc_Node) in N_Raise_xxx_Error
2307 or else Etype (Assoc_Node) /= Standard_Void_Type)
2308 and then (Nkind (Assoc_Node) /= N_Attribute_Reference
2310 not Is_Procedure_Attribute_Name
2311 (Attribute_Name (Assoc_Node)))
2313 P := Assoc_Node; -- ??? does not agree with above!
2314 N := Parent (Assoc_Node);
2316 -- Non-subexpression case. Note that N is initially Empty in this
2317 -- case (N is only guaranteed Non-Empty in the subexpr case).
2324 -- Capture root of the transient scope
2326 if Scope_Is_Transient then
2327 Wrapped_Node := Node_To_Be_Wrapped;
2331 pragma Assert (Present (P));
2335 -- Case of right operand of AND THEN or OR ELSE. Put the actions
2336 -- in the Actions field of the right operand. They will be moved
2337 -- out further when the AND THEN or OR ELSE operator is expanded.
2338 -- Nothing special needs to be done for the left operand since
2339 -- in that case the actions are executed unconditionally.
2341 when N_And_Then | N_Or_Else =>
2342 if N = Right_Opnd (P) then
2343 if Present (Actions (P)) then
2344 Insert_List_After_And_Analyze
2345 (Last (Actions (P)), Ins_Actions);
2347 Set_Actions (P, Ins_Actions);
2348 Analyze_List (Actions (P));
2354 -- Then or Else operand of conditional expression. Add actions to
2355 -- Then_Actions or Else_Actions field as appropriate. The actions
2356 -- will be moved further out when the conditional is expanded.
2358 when N_Conditional_Expression =>
2360 ThenX : constant Node_Id := Next (First (Expressions (P)));
2361 ElseX : constant Node_Id := Next (ThenX);
2364 -- Actions belong to the then expression, temporarily
2365 -- place them as Then_Actions of the conditional expr.
2366 -- They will be moved to the proper place later when
2367 -- the conditional expression is expanded.
2370 if Present (Then_Actions (P)) then
2371 Insert_List_After_And_Analyze
2372 (Last (Then_Actions (P)), Ins_Actions);
2374 Set_Then_Actions (P, Ins_Actions);
2375 Analyze_List (Then_Actions (P));
2380 -- Actions belong to the else expression, temporarily
2381 -- place them as Else_Actions of the conditional expr.
2382 -- They will be moved to the proper place later when
2383 -- the conditional expression is expanded.
2385 elsif N = ElseX then
2386 if Present (Else_Actions (P)) then
2387 Insert_List_After_And_Analyze
2388 (Last (Else_Actions (P)), Ins_Actions);
2390 Set_Else_Actions (P, Ins_Actions);
2391 Analyze_List (Else_Actions (P));
2396 -- Actions belong to the condition. In this case they are
2397 -- unconditionally executed, and so we can continue the
2398 -- search for the proper insert point.
2405 -- Case of appearing in the condition of a while expression or
2406 -- elsif. We insert the actions into the Condition_Actions field.
2407 -- They will be moved further out when the while loop or elsif
2410 when N_Iteration_Scheme |
2413 if N = Condition (P) then
2414 if Present (Condition_Actions (P)) then
2415 Insert_List_After_And_Analyze
2416 (Last (Condition_Actions (P)), Ins_Actions);
2418 Set_Condition_Actions (P, Ins_Actions);
2420 -- Set the parent of the insert actions explicitly.
2421 -- This is not a syntactic field, but we need the
2422 -- parent field set, in particular so that freeze
2423 -- can understand that it is dealing with condition
2424 -- actions, and properly insert the freezing actions.
2426 Set_Parent (Ins_Actions, P);
2427 Analyze_List (Condition_Actions (P));
2433 -- Statements, declarations, pragmas, representation clauses
2438 N_Procedure_Call_Statement |
2439 N_Statement_Other_Than_Procedure_Call |
2445 -- Representation_Clause
2448 N_Attribute_Definition_Clause |
2449 N_Enumeration_Representation_Clause |
2450 N_Record_Representation_Clause |
2454 N_Abstract_Subprogram_Declaration |
2456 N_Exception_Declaration |
2457 N_Exception_Renaming_Declaration |
2458 N_Formal_Abstract_Subprogram_Declaration |
2459 N_Formal_Concrete_Subprogram_Declaration |
2460 N_Formal_Object_Declaration |
2461 N_Formal_Type_Declaration |
2462 N_Full_Type_Declaration |
2463 N_Function_Instantiation |
2464 N_Generic_Function_Renaming_Declaration |
2465 N_Generic_Package_Declaration |
2466 N_Generic_Package_Renaming_Declaration |
2467 N_Generic_Procedure_Renaming_Declaration |
2468 N_Generic_Subprogram_Declaration |
2469 N_Implicit_Label_Declaration |
2470 N_Incomplete_Type_Declaration |
2471 N_Number_Declaration |
2472 N_Object_Declaration |
2473 N_Object_Renaming_Declaration |
2475 N_Package_Body_Stub |
2476 N_Package_Declaration |
2477 N_Package_Instantiation |
2478 N_Package_Renaming_Declaration |
2479 N_Private_Extension_Declaration |
2480 N_Private_Type_Declaration |
2481 N_Procedure_Instantiation |
2482 N_Protected_Body_Stub |
2483 N_Protected_Type_Declaration |
2484 N_Single_Task_Declaration |
2486 N_Subprogram_Body_Stub |
2487 N_Subprogram_Declaration |
2488 N_Subprogram_Renaming_Declaration |
2489 N_Subtype_Declaration |
2492 N_Task_Type_Declaration |
2494 -- Freeze entity behaves like a declaration or statement
2498 -- Do not insert here if the item is not a list member (this
2499 -- happens for example with a triggering statement, and the
2500 -- proper approach is to insert before the entire select).
2502 if not Is_List_Member (P) then
2505 -- Do not insert if parent of P is an N_Component_Association
2506 -- node (i.e. we are in the context of an N_Aggregate or
2507 -- N_Extension_Aggregate node. In this case we want to insert
2508 -- before the entire aggregate.
2510 elsif Nkind (Parent (P)) = N_Component_Association then
2513 -- Do not insert if the parent of P is either an N_Variant
2514 -- node or an N_Record_Definition node, meaning in either
2515 -- case that P is a member of a component list, and that
2516 -- therefore the actions should be inserted outside the
2517 -- complete record declaration.
2519 elsif Nkind (Parent (P)) = N_Variant
2520 or else Nkind (Parent (P)) = N_Record_Definition
2524 -- Do not insert freeze nodes within the loop generated for
2525 -- an aggregate, because they may be elaborated too late for
2526 -- subsequent use in the back end: within a package spec the
2527 -- loop is part of the elaboration procedure and is only
2528 -- elaborated during the second pass.
2529 -- If the loop comes from source, or the entity is local to
2530 -- the loop itself it must remain within.
2532 elsif Nkind (Parent (P)) = N_Loop_Statement
2533 and then not Comes_From_Source (Parent (P))
2534 and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
2536 Scope (Entity (First (Ins_Actions))) /= Current_Scope
2540 -- Otherwise we can go ahead and do the insertion
2542 elsif P = Wrapped_Node then
2543 Store_Before_Actions_In_Scope (Ins_Actions);
2547 Insert_List_Before_And_Analyze (P, Ins_Actions);
2551 -- A special case, N_Raise_xxx_Error can act either as a
2552 -- statement or a subexpression. We tell the difference
2553 -- by looking at the Etype. It is set to Standard_Void_Type
2554 -- in the statement case.
2557 N_Raise_xxx_Error =>
2558 if Etype (P) = Standard_Void_Type then
2559 if P = Wrapped_Node then
2560 Store_Before_Actions_In_Scope (Ins_Actions);
2562 Insert_List_Before_And_Analyze (P, Ins_Actions);
2567 -- In the subexpression case, keep climbing
2573 -- If a component association appears within a loop created for
2574 -- an array aggregate, attach the actions to the association so
2575 -- they can be subsequently inserted within the loop. For other
2576 -- component associations insert outside of the aggregate. For
2577 -- an association that will generate a loop, its Loop_Actions
2578 -- attribute is already initialized (see exp_aggr.adb).
2580 -- The list of loop_actions can in turn generate additional ones,
2581 -- that are inserted before the associated node. If the associated
2582 -- node is outside the aggregate, the new actions are collected
2583 -- at the end of the loop actions, to respect the order in which
2584 -- they are to be elaborated.
2587 N_Component_Association =>
2588 if Nkind (Parent (P)) = N_Aggregate
2589 and then Present (Loop_Actions (P))
2591 if Is_Empty_List (Loop_Actions (P)) then
2592 Set_Loop_Actions (P, Ins_Actions);
2593 Analyze_List (Ins_Actions);
2600 -- Check whether these actions were generated
2601 -- by a declaration that is part of the loop_
2602 -- actions for the component_association.
2605 while Present (Decl) loop
2606 exit when Parent (Decl) = P
2607 and then Is_List_Member (Decl)
2609 List_Containing (Decl) = Loop_Actions (P);
2610 Decl := Parent (Decl);
2613 if Present (Decl) then
2614 Insert_List_Before_And_Analyze
2615 (Decl, Ins_Actions);
2617 Insert_List_After_And_Analyze
2618 (Last (Loop_Actions (P)), Ins_Actions);
2629 -- Another special case, an attribute denoting a procedure call
2632 N_Attribute_Reference =>
2633 if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
2634 if P = Wrapped_Node then
2635 Store_Before_Actions_In_Scope (Ins_Actions);
2637 Insert_List_Before_And_Analyze (P, Ins_Actions);
2642 -- In the subexpression case, keep climbing
2648 -- For all other node types, keep climbing tree
2652 N_Accept_Alternative |
2653 N_Access_Definition |
2654 N_Access_Function_Definition |
2655 N_Access_Procedure_Definition |
2656 N_Access_To_Object_Definition |
2659 N_Case_Statement_Alternative |
2660 N_Character_Literal |
2661 N_Compilation_Unit |
2662 N_Compilation_Unit_Aux |
2663 N_Component_Clause |
2664 N_Component_Declaration |
2665 N_Component_Definition |
2667 N_Constrained_Array_Definition |
2668 N_Decimal_Fixed_Point_Definition |
2669 N_Defining_Character_Literal |
2670 N_Defining_Identifier |
2671 N_Defining_Operator_Symbol |
2672 N_Defining_Program_Unit_Name |
2673 N_Delay_Alternative |
2674 N_Delta_Constraint |
2675 N_Derived_Type_Definition |
2677 N_Digits_Constraint |
2678 N_Discriminant_Association |
2679 N_Discriminant_Specification |
2681 N_Entry_Body_Formal_Part |
2682 N_Entry_Call_Alternative |
2683 N_Entry_Declaration |
2684 N_Entry_Index_Specification |
2685 N_Enumeration_Type_Definition |
2687 N_Exception_Handler |
2689 N_Explicit_Dereference |
2690 N_Extension_Aggregate |
2691 N_Floating_Point_Definition |
2692 N_Formal_Decimal_Fixed_Point_Definition |
2693 N_Formal_Derived_Type_Definition |
2694 N_Formal_Discrete_Type_Definition |
2695 N_Formal_Floating_Point_Definition |
2696 N_Formal_Modular_Type_Definition |
2697 N_Formal_Ordinary_Fixed_Point_Definition |
2698 N_Formal_Package_Declaration |
2699 N_Formal_Private_Type_Definition |
2700 N_Formal_Signed_Integer_Type_Definition |
2702 N_Function_Specification |
2703 N_Generic_Association |
2704 N_Handled_Sequence_Of_Statements |
2707 N_Index_Or_Discriminant_Constraint |
2708 N_Indexed_Component |
2712 N_Loop_Parameter_Specification |
2714 N_Modular_Type_Definition |
2740 N_Op_Shift_Right_Arithmetic |
2744 N_Ordinary_Fixed_Point_Definition |
2746 N_Package_Specification |
2747 N_Parameter_Association |
2748 N_Parameter_Specification |
2749 N_Pop_Constraint_Error_Label |
2750 N_Pop_Program_Error_Label |
2751 N_Pop_Storage_Error_Label |
2752 N_Pragma_Argument_Association |
2753 N_Procedure_Specification |
2755 N_Protected_Definition |
2756 N_Push_Constraint_Error_Label |
2757 N_Push_Program_Error_Label |
2758 N_Push_Storage_Error_Label |
2759 N_Qualified_Expression |
2761 N_Range_Constraint |
2763 N_Real_Range_Specification |
2764 N_Record_Definition |
2766 N_Selected_Component |
2767 N_Signed_Integer_Type_Definition |
2768 N_Single_Protected_Declaration |
2772 N_Subtype_Indication |
2775 N_Terminate_Alternative |
2776 N_Triggering_Alternative |
2778 N_Unchecked_Expression |
2779 N_Unchecked_Type_Conversion |
2780 N_Unconstrained_Array_Definition |
2783 N_Use_Package_Clause |
2787 N_Validate_Unchecked_Conversion |
2794 -- Make sure that inserted actions stay in the transient scope
2796 if P = Wrapped_Node then
2797 Store_Before_Actions_In_Scope (Ins_Actions);
2801 -- If we fall through above tests, keep climbing tree
2805 if Nkind (Parent (N)) = N_Subunit then
2807 -- This is the proper body corresponding to a stub. Insertion
2808 -- must be done at the point of the stub, which is in the decla-
2809 -- tive part of the parent unit.
2811 P := Corresponding_Stub (Parent (N));
2819 -- Version with check(s) suppressed
2821 procedure Insert_Actions
2822 (Assoc_Node : Node_Id;
2823 Ins_Actions : List_Id;
2824 Suppress : Check_Id)
2827 if Suppress = All_Checks then
2829 Svg : constant Suppress_Array := Scope_Suppress;
2831 Scope_Suppress := (others => True);
2832 Insert_Actions (Assoc_Node, Ins_Actions);
2833 Scope_Suppress := Svg;
2838 Svg : constant Boolean := Scope_Suppress (Suppress);
2840 Scope_Suppress (Suppress) := True;
2841 Insert_Actions (Assoc_Node, Ins_Actions);
2842 Scope_Suppress (Suppress) := Svg;
2847 --------------------------
2848 -- Insert_Actions_After --
2849 --------------------------
2851 procedure Insert_Actions_After
2852 (Assoc_Node : Node_Id;
2853 Ins_Actions : List_Id)
2856 if Scope_Is_Transient
2857 and then Assoc_Node = Node_To_Be_Wrapped
2859 Store_After_Actions_In_Scope (Ins_Actions);
2861 Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
2863 end Insert_Actions_After;
2865 ---------------------------------
2866 -- Insert_Library_Level_Action --
2867 ---------------------------------
2869 procedure Insert_Library_Level_Action (N : Node_Id) is
2870 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2873 Push_Scope (Cunit_Entity (Main_Unit));
2874 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2876 if No (Actions (Aux)) then
2877 Set_Actions (Aux, New_List (N));
2879 Append (N, Actions (Aux));
2884 end Insert_Library_Level_Action;
2886 ----------------------------------
2887 -- Insert_Library_Level_Actions --
2888 ----------------------------------
2890 procedure Insert_Library_Level_Actions (L : List_Id) is
2891 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2894 if Is_Non_Empty_List (L) then
2895 Push_Scope (Cunit_Entity (Main_Unit));
2896 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2898 if No (Actions (Aux)) then
2899 Set_Actions (Aux, L);
2902 Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
2907 end Insert_Library_Level_Actions;
2909 ----------------------
2910 -- Inside_Init_Proc --
2911 ----------------------
2913 function Inside_Init_Proc return Boolean is
2919 and then S /= Standard_Standard
2921 if Is_Init_Proc (S) then
2929 end Inside_Init_Proc;
2931 ----------------------------
2932 -- Is_All_Null_Statements --
2933 ----------------------------
2935 function Is_All_Null_Statements (L : List_Id) return Boolean is
2940 while Present (Stm) loop
2941 if Nkind (Stm) /= N_Null_Statement then
2949 end Is_All_Null_Statements;
2951 -----------------------------------------
2952 -- Is_Predefined_Dispatching_Operation --
2953 -----------------------------------------
2955 function Is_Predefined_Dispatching_Operation (E : Entity_Id) return Boolean
2957 TSS_Name : TSS_Name_Type;
2960 if not Is_Dispatching_Operation (E) then
2964 Get_Name_String (Chars (E));
2966 if Name_Len > TSS_Name_Type'Last then
2967 TSS_Name := TSS_Name_Type (Name_Buffer (Name_Len - TSS_Name'Length + 1
2969 if Chars (E) = Name_uSize
2970 or else Chars (E) = Name_uAlignment
2971 or else TSS_Name = TSS_Stream_Read
2972 or else TSS_Name = TSS_Stream_Write
2973 or else TSS_Name = TSS_Stream_Input
2974 or else TSS_Name = TSS_Stream_Output
2976 (Chars (E) = Name_Op_Eq
2977 and then Etype (First_Entity (E)) = Etype (Last_Entity (E)))
2978 or else Chars (E) = Name_uAssign
2979 or else TSS_Name = TSS_Deep_Adjust
2980 or else TSS_Name = TSS_Deep_Finalize
2981 or else (Ada_Version >= Ada_05
2982 and then (Chars (E) = Name_uDisp_Asynchronous_Select
2983 or else Chars (E) = Name_uDisp_Conditional_Select
2984 or else Chars (E) = Name_uDisp_Get_Prim_Op_Kind
2985 or else Chars (E) = Name_uDisp_Get_Task_Id
2986 or else Chars (E) = Name_uDisp_Timed_Select))
2993 end Is_Predefined_Dispatching_Operation;
2995 ----------------------------------
2996 -- Is_Possibly_Unaligned_Object --
2997 ----------------------------------
2999 function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is
3000 T : constant Entity_Id := Etype (N);
3003 -- If renamed object, apply test to underlying object
3005 if Is_Entity_Name (N)
3006 and then Is_Object (Entity (N))
3007 and then Present (Renamed_Object (Entity (N)))
3009 return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N)));
3012 -- Tagged and controlled types and aliased types are always aligned,
3013 -- as are concurrent types.
3016 or else Has_Controlled_Component (T)
3017 or else Is_Concurrent_Type (T)
3018 or else Is_Tagged_Type (T)
3019 or else Is_Controlled (T)
3024 -- If this is an element of a packed array, may be unaligned
3026 if Is_Ref_To_Bit_Packed_Array (N) then
3030 -- Case of component reference
3032 if Nkind (N) = N_Selected_Component then
3034 P : constant Node_Id := Prefix (N);
3035 C : constant Entity_Id := Entity (Selector_Name (N));
3040 -- If component reference is for an array with non-static bounds,
3041 -- then it is always aligned: we can only process unaligned
3042 -- arrays with static bounds (more accurately bounds known at
3045 if Is_Array_Type (T)
3046 and then not Compile_Time_Known_Bounds (T)
3051 -- If component is aliased, it is definitely properly aligned
3053 if Is_Aliased (C) then
3057 -- If component is for a type implemented as a scalar, and the
3058 -- record is packed, and the component is other than the first
3059 -- component of the record, then the component may be unaligned.
3061 if Is_Packed (Etype (P))
3062 and then Represented_As_Scalar (Etype (C))
3063 and then First_Entity (Scope (C)) /= C
3068 -- Compute maximum possible alignment for T
3070 -- If alignment is known, then that settles things
3072 if Known_Alignment (T) then
3073 M := UI_To_Int (Alignment (T));
3075 -- If alignment is not known, tentatively set max alignment
3078 M := Ttypes.Maximum_Alignment;
3080 -- We can reduce this if the Esize is known since the default
3081 -- alignment will never be more than the smallest power of 2
3082 -- that does not exceed this Esize value.
3084 if Known_Esize (T) then
3085 S := UI_To_Int (Esize (T));
3087 while (M / 2) >= S loop
3093 -- If the component reference is for a record that has a specified
3094 -- alignment, and we either know it is too small, or cannot tell,
3095 -- then the component may be unaligned
3097 if Known_Alignment (Etype (P))
3098 and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment
3099 and then M > Alignment (Etype (P))
3104 -- Case of component clause present which may specify an
3105 -- unaligned position.
3107 if Present (Component_Clause (C)) then
3109 -- Otherwise we can do a test to make sure that the actual
3110 -- start position in the record, and the length, are both
3111 -- consistent with the required alignment. If not, we know
3112 -- that we are unaligned.
3115 Align_In_Bits : constant Nat := M * System_Storage_Unit;
3117 if Component_Bit_Offset (C) mod Align_In_Bits /= 0
3118 or else Esize (C) mod Align_In_Bits /= 0
3125 -- Otherwise, for a component reference, test prefix
3127 return Is_Possibly_Unaligned_Object (P);
3130 -- If not a component reference, must be aligned
3135 end Is_Possibly_Unaligned_Object;
3137 ---------------------------------
3138 -- Is_Possibly_Unaligned_Slice --
3139 ---------------------------------
3141 function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is
3143 -- Go to renamed object
3145 if Is_Entity_Name (N)
3146 and then Is_Object (Entity (N))
3147 and then Present (Renamed_Object (Entity (N)))
3149 return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N)));
3152 -- The reference must be a slice
3154 if Nkind (N) /= N_Slice then
3158 -- Always assume the worst for a nested record component with a
3159 -- component clause, which gigi/gcc does not appear to handle well.
3160 -- It is not clear why this special test is needed at all ???
3162 if Nkind (Prefix (N)) = N_Selected_Component
3163 and then Nkind (Prefix (Prefix (N))) = N_Selected_Component
3165 Present (Component_Clause (Entity (Selector_Name (Prefix (N)))))
3170 -- We only need to worry if the target has strict alignment
3172 if not Target_Strict_Alignment then
3176 -- If it is a slice, then look at the array type being sliced
3179 Sarr : constant Node_Id := Prefix (N);
3180 -- Prefix of the slice, i.e. the array being sliced
3182 Styp : constant Entity_Id := Etype (Prefix (N));
3183 -- Type of the array being sliced
3189 -- The problems arise if the array object that is being sliced
3190 -- is a component of a record or array, and we cannot guarantee
3191 -- the alignment of the array within its containing object.
3193 -- To investigate this, we look at successive prefixes to see
3194 -- if we have a worrisome indexed or selected component.
3198 -- Case of array is part of an indexed component reference
3200 if Nkind (Pref) = N_Indexed_Component then
3201 Ptyp := Etype (Prefix (Pref));
3203 -- The only problematic case is when the array is packed,
3204 -- in which case we really know nothing about the alignment
3205 -- of individual components.
3207 if Is_Bit_Packed_Array (Ptyp) then
3211 -- Case of array is part of a selected component reference
3213 elsif Nkind (Pref) = N_Selected_Component then
3214 Ptyp := Etype (Prefix (Pref));
3216 -- We are definitely in trouble if the record in question
3217 -- has an alignment, and either we know this alignment is
3218 -- inconsistent with the alignment of the slice, or we
3219 -- don't know what the alignment of the slice should be.
3221 if Known_Alignment (Ptyp)
3222 and then (Unknown_Alignment (Styp)
3223 or else Alignment (Styp) > Alignment (Ptyp))
3228 -- We are in potential trouble if the record type is packed.
3229 -- We could special case when we know that the array is the
3230 -- first component, but that's not such a simple case ???
3232 if Is_Packed (Ptyp) then
3236 -- We are in trouble if there is a component clause, and
3237 -- either we do not know the alignment of the slice, or
3238 -- the alignment of the slice is inconsistent with the
3239 -- bit position specified by the component clause.
3242 Field : constant Entity_Id := Entity (Selector_Name (Pref));
3244 if Present (Component_Clause (Field))
3246 (Unknown_Alignment (Styp)
3248 (Component_Bit_Offset (Field) mod
3249 (System_Storage_Unit * Alignment (Styp))) /= 0)
3255 -- For cases other than selected or indexed components we
3256 -- know we are OK, since no issues arise over alignment.
3262 -- We processed an indexed component or selected component
3263 -- reference that looked safe, so keep checking prefixes.
3265 Pref := Prefix (Pref);
3268 end Is_Possibly_Unaligned_Slice;
3270 --------------------------------
3271 -- Is_Ref_To_Bit_Packed_Array --
3272 --------------------------------
3274 function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is
3279 if Is_Entity_Name (N)
3280 and then Is_Object (Entity (N))
3281 and then Present (Renamed_Object (Entity (N)))
3283 return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N)));
3286 if Nkind (N) = N_Indexed_Component
3288 Nkind (N) = N_Selected_Component
3290 if Is_Bit_Packed_Array (Etype (Prefix (N))) then
3293 Result := Is_Ref_To_Bit_Packed_Array (Prefix (N));
3296 if Result and then Nkind (N) = N_Indexed_Component then
3297 Expr := First (Expressions (N));
3298 while Present (Expr) loop
3299 Force_Evaluation (Expr);
3309 end Is_Ref_To_Bit_Packed_Array;
3311 --------------------------------
3312 -- Is_Ref_To_Bit_Packed_Slice --
3313 --------------------------------
3315 function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is
3317 if Nkind (N) = N_Type_Conversion then
3318 return Is_Ref_To_Bit_Packed_Slice (Expression (N));
3320 elsif Is_Entity_Name (N)
3321 and then Is_Object (Entity (N))
3322 and then Present (Renamed_Object (Entity (N)))
3324 return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N)));
3326 elsif Nkind (N) = N_Slice
3327 and then Is_Bit_Packed_Array (Etype (Prefix (N)))
3331 elsif Nkind (N) = N_Indexed_Component
3333 Nkind (N) = N_Selected_Component
3335 return Is_Ref_To_Bit_Packed_Slice (Prefix (N));
3340 end Is_Ref_To_Bit_Packed_Slice;
3342 -----------------------
3343 -- Is_Renamed_Object --
3344 -----------------------
3346 function Is_Renamed_Object (N : Node_Id) return Boolean is
3347 Pnod : constant Node_Id := Parent (N);
3348 Kind : constant Node_Kind := Nkind (Pnod);
3351 if Kind = N_Object_Renaming_Declaration then
3354 elsif Kind = N_Indexed_Component
3355 or else Kind = N_Selected_Component
3357 return Is_Renamed_Object (Pnod);
3362 end Is_Renamed_Object;
3364 ----------------------------
3365 -- Is_Untagged_Derivation --
3366 ----------------------------
3368 function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
3370 return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
3372 (Is_Private_Type (T) and then Present (Full_View (T))
3373 and then not Is_Tagged_Type (Full_View (T))
3374 and then Is_Derived_Type (Full_View (T))
3375 and then Etype (Full_View (T)) /= T);
3376 end Is_Untagged_Derivation;
3378 --------------------
3379 -- Kill_Dead_Code --
3380 --------------------
3382 procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is
3385 Remove_Warning_Messages (N);
3389 ("?this code can never be executed and has been deleted", N);
3392 -- Recurse into block statements and bodies to process declarations
3395 if Nkind (N) = N_Block_Statement
3396 or else Nkind (N) = N_Subprogram_Body
3397 or else Nkind (N) = N_Package_Body
3400 (Declarations (N), False);
3402 (Statements (Handled_Statement_Sequence (N)));
3404 if Nkind (N) = N_Subprogram_Body then
3405 Set_Is_Eliminated (Defining_Entity (N));
3408 elsif Nkind (N) = N_Package_Declaration then
3409 Kill_Dead_Code (Visible_Declarations (Specification (N)));
3410 Kill_Dead_Code (Private_Declarations (Specification (N)));
3413 E : Entity_Id := First_Entity (Defining_Entity (N));
3415 while Present (E) loop
3416 if Ekind (E) = E_Operator then
3417 Set_Is_Eliminated (E);
3424 -- Recurse into composite statement to kill individual statements,
3425 -- in particular instantiations.
3427 elsif Nkind (N) = N_If_Statement then
3428 Kill_Dead_Code (Then_Statements (N));
3429 Kill_Dead_Code (Elsif_Parts (N));
3430 Kill_Dead_Code (Else_Statements (N));
3432 elsif Nkind (N) = N_Loop_Statement then
3433 Kill_Dead_Code (Statements (N));
3435 elsif Nkind (N) = N_Case_Statement then
3439 Alt := First (Alternatives (N));
3440 while Present (Alt) loop
3441 Kill_Dead_Code (Statements (Alt));
3446 elsif Nkind (N) = N_Case_Statement_Alternative then
3447 Kill_Dead_Code (Statements (N));
3449 -- Deal with dead instances caused by deleting instantiations
3451 elsif Nkind (N) in N_Generic_Instantiation then
3452 Remove_Dead_Instance (N);
3459 -- Case where argument is a list of nodes to be killed
3461 procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is
3466 if Is_Non_Empty_List (L) then
3468 N := Remove_Head (L);
3470 Kill_Dead_Code (N, W);
3476 ------------------------
3477 -- Known_Non_Negative --
3478 ------------------------
3480 function Known_Non_Negative (Opnd : Node_Id) return Boolean is
3482 if Is_OK_Static_Expression (Opnd)
3483 and then Expr_Value (Opnd) >= 0
3489 Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd));
3493 Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0;
3496 end Known_Non_Negative;
3498 --------------------
3499 -- Known_Non_Null --
3500 --------------------
3502 function Known_Non_Null (N : Node_Id) return Boolean is
3504 -- Checks for case where N is an entity reference
3506 if Is_Entity_Name (N) and then Present (Entity (N)) then
3508 E : constant Entity_Id := Entity (N);
3513 -- First check if we are in decisive conditional
3515 Get_Current_Value_Condition (N, Op, Val);
3517 if Nkind (Val) = N_Null then
3518 if Op = N_Op_Eq then
3520 elsif Op = N_Op_Ne then
3525 -- If OK to do replacement, test Is_Known_Non_Null flag
3527 if OK_To_Do_Constant_Replacement (E) then
3528 return Is_Known_Non_Null (E);
3530 -- Otherwise if not safe to do replacement, then say so
3537 -- True if access attribute
3539 elsif Nkind (N) = N_Attribute_Reference
3540 and then (Attribute_Name (N) = Name_Access
3542 Attribute_Name (N) = Name_Unchecked_Access
3544 Attribute_Name (N) = Name_Unrestricted_Access)
3548 -- True if allocator
3550 elsif Nkind (N) = N_Allocator then
3553 -- For a conversion, true if expression is known non-null
3555 elsif Nkind (N) = N_Type_Conversion then
3556 return Known_Non_Null (Expression (N));
3558 -- Above are all cases where the value could be determined to be
3559 -- non-null. In all other cases, we don't know, so return False.
3570 function Known_Null (N : Node_Id) return Boolean is
3572 -- Checks for case where N is an entity reference
3574 if Is_Entity_Name (N) and then Present (Entity (N)) then
3576 E : constant Entity_Id := Entity (N);
3581 -- First check if we are in decisive conditional
3583 Get_Current_Value_Condition (N, Op, Val);
3585 if Nkind (Val) = N_Null then
3586 if Op = N_Op_Eq then
3588 elsif Op = N_Op_Ne then
3593 -- If OK to do replacement, test Is_Known_Null flag
3595 if OK_To_Do_Constant_Replacement (E) then
3596 return Is_Known_Null (E);
3598 -- Otherwise if not safe to do replacement, then say so
3605 -- True if explicit reference to null
3607 elsif Nkind (N) = N_Null then
3610 -- For a conversion, true if expression is known null
3612 elsif Nkind (N) = N_Type_Conversion then
3613 return Known_Null (Expression (N));
3615 -- Above are all cases where the value could be determined to be null.
3616 -- In all other cases, we don't know, so return False.
3623 -----------------------------
3624 -- Make_CW_Equivalent_Type --
3625 -----------------------------
3627 -- Create a record type used as an equivalent of any member
3628 -- of the class which takes its size from exp.
3630 -- Generate the following code:
3632 -- type Equiv_T is record
3633 -- _parent : T (List of discriminant constaints taken from Exp);
3634 -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
3637 -- ??? Note that this type does not guarantee same alignment as all
3640 function Make_CW_Equivalent_Type
3642 E : Node_Id) return Entity_Id
3644 Loc : constant Source_Ptr := Sloc (E);
3645 Root_Typ : constant Entity_Id := Root_Type (T);
3646 List_Def : constant List_Id := Empty_List;
3647 Comp_List : constant List_Id := New_List;
3648 Equiv_Type : Entity_Id;
3649 Range_Type : Entity_Id;
3650 Str_Type : Entity_Id;
3651 Constr_Root : Entity_Id;
3655 if not Has_Discriminants (Root_Typ) then
3656 Constr_Root := Root_Typ;
3659 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
3661 -- subtype cstr__n is T (List of discr constraints taken from Exp)
3663 Append_To (List_Def,
3664 Make_Subtype_Declaration (Loc,
3665 Defining_Identifier => Constr_Root,
3666 Subtype_Indication =>
3667 Make_Subtype_From_Expr (E, Root_Typ)));
3670 -- Generate the range subtype declaration
3672 Range_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('G'));
3674 if not Is_Interface (Root_Typ) then
3675 -- subtype rg__xx is
3676 -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit
3679 Make_Op_Subtract (Loc,
3681 Make_Attribute_Reference (Loc,
3683 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3684 Attribute_Name => Name_Size),
3686 Make_Attribute_Reference (Loc,
3687 Prefix => New_Reference_To (Constr_Root, Loc),
3688 Attribute_Name => Name_Object_Size));
3690 -- subtype rg__xx is
3691 -- Storage_Offset range 1 .. Expr'size / Storage_Unit
3694 Make_Attribute_Reference (Loc,
3696 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3697 Attribute_Name => Name_Size);
3700 Set_Paren_Count (Sizexpr, 1);
3702 Append_To (List_Def,
3703 Make_Subtype_Declaration (Loc,
3704 Defining_Identifier => Range_Type,
3705 Subtype_Indication =>
3706 Make_Subtype_Indication (Loc,
3707 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc),
3708 Constraint => Make_Range_Constraint (Loc,
3711 Low_Bound => Make_Integer_Literal (Loc, 1),
3713 Make_Op_Divide (Loc,
3714 Left_Opnd => Sizexpr,
3715 Right_Opnd => Make_Integer_Literal (Loc,
3716 Intval => System_Storage_Unit)))))));
3718 -- subtype str__nn is Storage_Array (rg__x);
3720 Str_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
3721 Append_To (List_Def,
3722 Make_Subtype_Declaration (Loc,
3723 Defining_Identifier => Str_Type,
3724 Subtype_Indication =>
3725 Make_Subtype_Indication (Loc,
3726 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc),
3728 Make_Index_Or_Discriminant_Constraint (Loc,
3730 New_List (New_Reference_To (Range_Type, Loc))))));
3732 -- type Equiv_T is record
3733 -- [ _parent : Tnn; ]
3737 Equiv_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
3739 -- When the target requires front-end layout, it's necessary to allow
3740 -- the equivalent type to be frozen so that layout can occur (when the
3741 -- associated class-wide subtype is frozen, the equivalent type will
3742 -- be frozen, see freeze.adb). For other targets, Gigi wants to have
3743 -- the equivalent type marked as frozen and deals with this type itself.
3744 -- In the Gigi case this will also avoid the generation of an init
3745 -- procedure for the type.
3747 if not Frontend_Layout_On_Target then
3748 Set_Is_Frozen (Equiv_Type);
3751 Set_Ekind (Equiv_Type, E_Record_Type);
3752 Set_Parent_Subtype (Equiv_Type, Constr_Root);
3754 if not Is_Interface (Root_Typ) then
3755 Append_To (Comp_List,
3756 Make_Component_Declaration (Loc,
3757 Defining_Identifier =>
3758 Make_Defining_Identifier (Loc, Name_uParent),
3759 Component_Definition =>
3760 Make_Component_Definition (Loc,
3761 Aliased_Present => False,
3762 Subtype_Indication => New_Reference_To (Constr_Root, Loc))));
3765 Append_To (Comp_List,
3766 Make_Component_Declaration (Loc,
3767 Defining_Identifier =>
3768 Make_Defining_Identifier (Loc,
3769 Chars => New_Internal_Name ('C')),
3770 Component_Definition =>
3771 Make_Component_Definition (Loc,
3772 Aliased_Present => False,
3773 Subtype_Indication => New_Reference_To (Str_Type, Loc))));
3775 Append_To (List_Def,
3776 Make_Full_Type_Declaration (Loc,
3777 Defining_Identifier => Equiv_Type,
3779 Make_Record_Definition (Loc,
3781 Make_Component_List (Loc,
3782 Component_Items => Comp_List,
3783 Variant_Part => Empty))));
3785 -- Suppress all checks during the analysis of the expanded code
3786 -- to avoid the generation of spurious warnings under ZFP run-time.
3788 Insert_Actions (E, List_Def, Suppress => All_Checks);
3790 end Make_CW_Equivalent_Type;
3792 ------------------------
3793 -- Make_Literal_Range --
3794 ------------------------
3796 function Make_Literal_Range
3798 Literal_Typ : Entity_Id) return Node_Id
3800 Lo : constant Node_Id :=
3801 New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
3804 Set_Analyzed (Lo, False);
3811 Make_Op_Subtract (Loc,
3814 Left_Opnd => New_Copy_Tree (Lo),
3816 Make_Integer_Literal (Loc,
3817 String_Literal_Length (Literal_Typ))),
3818 Right_Opnd => Make_Integer_Literal (Loc, 1)));
3819 end Make_Literal_Range;
3821 ----------------------------
3822 -- Make_Subtype_From_Expr --
3823 ----------------------------
3825 -- 1. If Expr is an uncontrained array expression, creates
3826 -- Unc_Type(Expr'first(1)..Expr'Last(1),..., Expr'first(n)..Expr'last(n))
3828 -- 2. If Expr is a unconstrained discriminated type expression, creates
3829 -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
3831 -- 3. If Expr is class-wide, creates an implicit class wide subtype
3833 function Make_Subtype_From_Expr
3835 Unc_Typ : Entity_Id) return Node_Id
3837 Loc : constant Source_Ptr := Sloc (E);
3838 List_Constr : constant List_Id := New_List;
3841 Full_Subtyp : Entity_Id;
3842 Priv_Subtyp : Entity_Id;
3847 if Is_Private_Type (Unc_Typ)
3848 and then Has_Unknown_Discriminants (Unc_Typ)
3850 -- Prepare the subtype completion, Go to base type to
3851 -- find underlying type, because the type may be a generic
3852 -- actual or an explicit subtype.
3854 Utyp := Underlying_Type (Base_Type (Unc_Typ));
3855 Full_Subtyp := Make_Defining_Identifier (Loc,
3856 New_Internal_Name ('C'));
3858 Unchecked_Convert_To
3859 (Utyp, Duplicate_Subexpr_No_Checks (E));
3860 Set_Parent (Full_Exp, Parent (E));
3863 Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
3866 Make_Subtype_Declaration (Loc,
3867 Defining_Identifier => Full_Subtyp,
3868 Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
3870 -- Define the dummy private subtype
3872 Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
3873 Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ));
3874 Set_Scope (Priv_Subtyp, Full_Subtyp);
3875 Set_Is_Constrained (Priv_Subtyp);
3876 Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
3877 Set_Is_Itype (Priv_Subtyp);
3878 Set_Associated_Node_For_Itype (Priv_Subtyp, E);
3880 if Is_Tagged_Type (Priv_Subtyp) then
3882 (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
3883 Set_Primitive_Operations (Priv_Subtyp,
3884 Primitive_Operations (Unc_Typ));
3887 Set_Full_View (Priv_Subtyp, Full_Subtyp);
3889 return New_Reference_To (Priv_Subtyp, Loc);
3891 elsif Is_Array_Type (Unc_Typ) then
3892 for J in 1 .. Number_Dimensions (Unc_Typ) loop
3893 Append_To (List_Constr,
3896 Make_Attribute_Reference (Loc,
3897 Prefix => Duplicate_Subexpr_No_Checks (E),
3898 Attribute_Name => Name_First,
3899 Expressions => New_List (
3900 Make_Integer_Literal (Loc, J))),
3903 Make_Attribute_Reference (Loc,
3904 Prefix => Duplicate_Subexpr_No_Checks (E),
3905 Attribute_Name => Name_Last,
3906 Expressions => New_List (
3907 Make_Integer_Literal (Loc, J)))));
3910 elsif Is_Class_Wide_Type (Unc_Typ) then
3912 CW_Subtype : Entity_Id;
3913 EQ_Typ : Entity_Id := Empty;
3916 -- A class-wide equivalent type is not needed when VM_Target
3917 -- because the VM back-ends handle the class-wide object
3918 -- initialization itself (and doesn't need or want the
3919 -- additional intermediate type to handle the assignment).
3921 if Expander_Active and then VM_Target = No_VM then
3922 EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
3925 CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
3926 Set_Equivalent_Type (CW_Subtype, EQ_Typ);
3928 if Present (EQ_Typ) then
3929 Set_Is_Class_Wide_Equivalent_Type (EQ_Typ);
3932 Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
3934 return New_Occurrence_Of (CW_Subtype, Loc);
3937 -- Indefinite record type with discriminants
3940 D := First_Discriminant (Unc_Typ);
3941 while Present (D) loop
3942 Append_To (List_Constr,
3943 Make_Selected_Component (Loc,
3944 Prefix => Duplicate_Subexpr_No_Checks (E),
3945 Selector_Name => New_Reference_To (D, Loc)));
3947 Next_Discriminant (D);
3952 Make_Subtype_Indication (Loc,
3953 Subtype_Mark => New_Reference_To (Unc_Typ, Loc),
3955 Make_Index_Or_Discriminant_Constraint (Loc,
3956 Constraints => List_Constr));
3957 end Make_Subtype_From_Expr;
3959 -----------------------------
3960 -- May_Generate_Large_Temp --
3961 -----------------------------
3963 -- At the current time, the only types that we return False for (i.e.
3964 -- where we decide we know they cannot generate large temps) are ones
3965 -- where we know the size is 256 bits or less at compile time, and we
3966 -- are still not doing a thorough job on arrays and records ???
3968 function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
3970 if not Size_Known_At_Compile_Time (Typ) then
3973 elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then
3976 elsif Is_Array_Type (Typ)
3977 and then Present (Packed_Array_Type (Typ))
3979 return May_Generate_Large_Temp (Packed_Array_Type (Typ));
3981 -- We could do more here to find other small types ???
3986 end May_Generate_Large_Temp;
3988 ----------------------------
3989 -- New_Class_Wide_Subtype --
3990 ----------------------------
3992 function New_Class_Wide_Subtype
3993 (CW_Typ : Entity_Id;
3994 N : Node_Id) return Entity_Id
3996 Res : constant Entity_Id := Create_Itype (E_Void, N);
3997 Res_Name : constant Name_Id := Chars (Res);
3998 Res_Scope : constant Entity_Id := Scope (Res);
4001 Copy_Node (CW_Typ, Res);
4002 Set_Comes_From_Source (Res, False);
4003 Set_Sloc (Res, Sloc (N));
4005 Set_Associated_Node_For_Itype (Res, N);
4006 Set_Is_Public (Res, False); -- By default, may be changed below.
4007 Set_Public_Status (Res);
4008 Set_Chars (Res, Res_Name);
4009 Set_Scope (Res, Res_Scope);
4010 Set_Ekind (Res, E_Class_Wide_Subtype);
4011 Set_Next_Entity (Res, Empty);
4012 Set_Etype (Res, Base_Type (CW_Typ));
4014 -- For targets where front-end layout is required, reset the Is_Frozen
4015 -- status of the subtype to False (it can be implicitly set to true
4016 -- from the copy of the class-wide type). For other targets, Gigi
4017 -- doesn't want the class-wide subtype to go through the freezing
4018 -- process (though it's unclear why that causes problems and it would
4019 -- be nice to allow freezing to occur normally for all targets ???).
4021 if Frontend_Layout_On_Target then
4022 Set_Is_Frozen (Res, False);
4025 Set_Freeze_Node (Res, Empty);
4027 end New_Class_Wide_Subtype;
4029 --------------------------------
4030 -- Non_Limited_Designated_Type --
4031 ---------------------------------
4033 function Non_Limited_Designated_Type (T : Entity_Id) return Entity_Id is
4034 Desig : constant Entity_Id := Designated_Type (T);
4036 if Ekind (Desig) = E_Incomplete_Type
4037 and then Present (Non_Limited_View (Desig))
4039 return Non_Limited_View (Desig);
4043 end Non_Limited_Designated_Type;
4045 -----------------------------------
4046 -- OK_To_Do_Constant_Replacement --
4047 -----------------------------------
4049 function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is
4050 ES : constant Entity_Id := Scope (E);
4054 -- Do not replace statically allocated objects, because they may be
4055 -- modified outside the current scope.
4057 if Is_Statically_Allocated (E) then
4060 -- Do not replace aliased or volatile objects, since we don't know what
4061 -- else might change the value.
4063 elsif Is_Aliased (E) or else Treat_As_Volatile (E) then
4066 -- Debug flag -gnatdM disconnects this optimization
4068 elsif Debug_Flag_MM then
4071 -- Otherwise check scopes
4074 CS := Current_Scope;
4077 -- If we are in right scope, replacement is safe
4082 -- Packages do not affect the determination of safety
4084 elsif Ekind (CS) = E_Package then
4085 exit when CS = Standard_Standard;
4088 -- Blocks do not affect the determination of safety
4090 elsif Ekind (CS) = E_Block then
4093 -- Loops do not affect the determination of safety. Note that we
4094 -- kill all current values on entry to a loop, so we are just
4095 -- talking about processing within a loop here.
4097 elsif Ekind (CS) = E_Loop then
4100 -- Otherwise, the reference is dubious, and we cannot be sure that
4101 -- it is safe to do the replacement.
4110 end OK_To_Do_Constant_Replacement;
4112 ------------------------------------
4113 -- Possible_Bit_Aligned_Component --
4114 ------------------------------------
4116 function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is
4120 -- Case of indexed component
4122 when N_Indexed_Component =>
4124 P : constant Node_Id := Prefix (N);
4125 Ptyp : constant Entity_Id := Etype (P);
4128 -- If we know the component size and it is less than 64, then
4129 -- we are definitely OK. The back end always does assignment
4130 -- of misaligned small objects correctly.
4132 if Known_Static_Component_Size (Ptyp)
4133 and then Component_Size (Ptyp) <= 64
4137 -- Otherwise, we need to test the prefix, to see if we are
4138 -- indexing from a possibly unaligned component.
4141 return Possible_Bit_Aligned_Component (P);
4145 -- Case of selected component
4147 when N_Selected_Component =>
4149 P : constant Node_Id := Prefix (N);
4150 Comp : constant Entity_Id := Entity (Selector_Name (N));
4153 -- If there is no component clause, then we are in the clear
4154 -- since the back end will never misalign a large component
4155 -- unless it is forced to do so. In the clear means we need
4156 -- only the recursive test on the prefix.
4158 if Component_May_Be_Bit_Aligned (Comp) then
4161 return Possible_Bit_Aligned_Component (P);
4165 -- If we have neither a record nor array component, it means that we
4166 -- have fallen off the top testing prefixes recursively, and we now
4167 -- have a stand alone object, where we don't have a problem.
4173 end Possible_Bit_Aligned_Component;
4175 -------------------------
4176 -- Remove_Side_Effects --
4177 -------------------------
4179 procedure Remove_Side_Effects
4181 Name_Req : Boolean := False;
4182 Variable_Ref : Boolean := False)
4184 Loc : constant Source_Ptr := Sloc (Exp);
4185 Exp_Type : constant Entity_Id := Etype (Exp);
4186 Svg_Suppress : constant Suppress_Array := Scope_Suppress;
4188 Ref_Type : Entity_Id;
4190 Ptr_Typ_Decl : Node_Id;
4194 function Side_Effect_Free (N : Node_Id) return Boolean;
4195 -- Determines if the tree N represents an expression that is known not
4196 -- to have side effects, and for which no processing is required.
4198 function Side_Effect_Free (L : List_Id) return Boolean;
4199 -- Determines if all elements of the list L are side effect free
4201 function Safe_Prefixed_Reference (N : Node_Id) return Boolean;
4202 -- The argument N is a construct where the Prefix is dereferenced if it
4203 -- is an access type and the result is a variable. The call returns True
4204 -- if the construct is side effect free (not considering side effects in
4205 -- other than the prefix which are to be tested by the caller).
4207 function Within_In_Parameter (N : Node_Id) return Boolean;
4208 -- Determines if N is a subcomponent of a composite in-parameter. If so,
4209 -- N is not side-effect free when the actual is global and modifiable
4210 -- indirectly from within a subprogram, because it may be passed by
4211 -- reference. The front-end must be conservative here and assume that
4212 -- this may happen with any array or record type. On the other hand, we
4213 -- cannot create temporaries for all expressions for which this
4214 -- condition is true, for various reasons that might require clearing up
4215 -- ??? For example, descriminant references that appear out of place, or
4216 -- spurious type errors with class-wide expressions. As a result, we
4217 -- limit the transformation to loop bounds, which is so far the only
4218 -- case that requires it.
4220 -----------------------------
4221 -- Safe_Prefixed_Reference --
4222 -----------------------------
4224 function Safe_Prefixed_Reference (N : Node_Id) return Boolean is
4226 -- If prefix is not side effect free, definitely not safe
4228 if not Side_Effect_Free (Prefix (N)) then
4231 -- If the prefix is of an access type that is not access-to-constant,
4232 -- then this construct is a variable reference, which means it is to
4233 -- be considered to have side effects if Variable_Ref is set True
4234 -- Exception is an access to an entity that is a constant or an
4235 -- in-parameter which does not come from source, and is the result
4236 -- of a previous removal of side-effects.
4238 elsif Is_Access_Type (Etype (Prefix (N)))
4239 and then not Is_Access_Constant (Etype (Prefix (N)))
4240 and then Variable_Ref
4242 if not Is_Entity_Name (Prefix (N)) then
4245 return Ekind (Entity (Prefix (N))) = E_Constant
4246 or else Ekind (Entity (Prefix (N))) = E_In_Parameter;
4249 -- The following test is the simplest way of solving a complex
4250 -- problem uncovered by BB08-010: Side effect on loop bound that
4251 -- is a subcomponent of a global variable:
4252 -- If a loop bound is a subcomponent of a global variable, a
4253 -- modification of that variable within the loop may incorrectly
4254 -- affect the execution of the loop.
4257 (Nkind (Parent (Parent (N))) /= N_Loop_Parameter_Specification
4258 or else not Within_In_Parameter (Prefix (N)))
4262 -- All other cases are side effect free
4267 end Safe_Prefixed_Reference;
4269 ----------------------
4270 -- Side_Effect_Free --
4271 ----------------------
4273 function Side_Effect_Free (N : Node_Id) return Boolean is
4275 -- Note on checks that could raise Constraint_Error. Strictly, if
4276 -- we take advantage of 11.6, these checks do not count as side
4277 -- effects. However, we would just as soon consider that they are
4278 -- side effects, since the backend CSE does not work very well on
4279 -- expressions which can raise Constraint_Error. On the other
4280 -- hand, if we do not consider them to be side effect free, then
4281 -- we get some awkward expansions in -gnato mode, resulting in
4282 -- code insertions at a point where we do not have a clear model
4283 -- for performing the insertions. See 4908-002/comment for details.
4285 -- Special handling for entity names
4287 if Is_Entity_Name (N) then
4289 -- If the entity is a constant, it is definitely side effect
4290 -- free. Note that the test of Is_Variable (N) below might
4291 -- be expected to catch this case, but it does not, because
4292 -- this test goes to the original tree, and we may have
4293 -- already rewritten a variable node with a constant as
4294 -- a result of an earlier Force_Evaluation call.
4296 if Ekind (Entity (N)) = E_Constant
4297 or else Ekind (Entity (N)) = E_In_Parameter
4301 -- Functions are not side effect free
4303 elsif Ekind (Entity (N)) = E_Function then
4306 -- Variables are considered to be a side effect if Variable_Ref
4307 -- is set or if we have a volatile variable and Name_Req is off.
4308 -- If Name_Req is True then we can't help returning a name which
4309 -- effectively allows multiple references in any case.
4311 elsif Is_Variable (N) then
4312 return not Variable_Ref
4313 and then (not Treat_As_Volatile (Entity (N))
4316 -- Any other entity (e.g. a subtype name) is definitely side
4323 -- A value known at compile time is always side effect free
4325 elsif Compile_Time_Known_Value (N) then
4328 -- A variable renaming is not side-effet free, because the
4329 -- renaming will function like a macro in the front-end in
4330 -- some cases, and an assignment can modify the the component
4331 -- designated by N, so we need to create a temporary for it.
4333 elsif Is_Entity_Name (Original_Node (N))
4334 and then Is_Renaming_Of_Object (Entity (Original_Node (N)))
4335 and then Ekind (Entity (Original_Node (N))) /= E_Constant
4340 -- For other than entity names and compile time known values,
4341 -- check the node kind for special processing.
4345 -- An attribute reference is side effect free if its expressions
4346 -- are side effect free and its prefix is side effect free or
4347 -- is an entity reference.
4349 -- Is this right? what about x'first where x is a variable???
4351 when N_Attribute_Reference =>
4352 return Side_Effect_Free (Expressions (N))
4353 and then Attribute_Name (N) /= Name_Input
4354 and then (Is_Entity_Name (Prefix (N))
4355 or else Side_Effect_Free (Prefix (N)));
4357 -- A binary operator is side effect free if and both operands
4358 -- are side effect free. For this purpose binary operators
4359 -- include membership tests and short circuit forms
4365 return Side_Effect_Free (Left_Opnd (N))
4366 and then Side_Effect_Free (Right_Opnd (N));
4368 -- An explicit dereference is side effect free only if it is
4369 -- a side effect free prefixed reference.
4371 when N_Explicit_Dereference =>
4372 return Safe_Prefixed_Reference (N);
4374 -- A call to _rep_to_pos is side effect free, since we generate
4375 -- this pure function call ourselves. Moreover it is critically
4376 -- important to make this exception, since otherwise we can
4377 -- have discriminants in array components which don't look
4378 -- side effect free in the case of an array whose index type
4379 -- is an enumeration type with an enumeration rep clause.
4381 -- All other function calls are not side effect free
4383 when N_Function_Call =>
4384 return Nkind (Name (N)) = N_Identifier
4385 and then Is_TSS (Name (N), TSS_Rep_To_Pos)
4387 Side_Effect_Free (First (Parameter_Associations (N)));
4389 -- An indexed component is side effect free if it is a side
4390 -- effect free prefixed reference and all the indexing
4391 -- expressions are side effect free.
4393 when N_Indexed_Component =>
4394 return Side_Effect_Free (Expressions (N))
4395 and then Safe_Prefixed_Reference (N);
4397 -- A type qualification is side effect free if the expression
4398 -- is side effect free.
4400 when N_Qualified_Expression =>
4401 return Side_Effect_Free (Expression (N));
4403 -- A selected component is side effect free only if it is a
4404 -- side effect free prefixed reference.
4406 when N_Selected_Component =>
4407 return Safe_Prefixed_Reference (N);
4409 -- A range is side effect free if the bounds are side effect free
4412 return Side_Effect_Free (Low_Bound (N))
4413 and then Side_Effect_Free (High_Bound (N));
4415 -- A slice is side effect free if it is a side effect free
4416 -- prefixed reference and the bounds are side effect free.
4419 return Side_Effect_Free (Discrete_Range (N))
4420 and then Safe_Prefixed_Reference (N);
4422 -- A type conversion is side effect free if the expression
4423 -- to be converted is side effect free.
4425 when N_Type_Conversion =>
4426 return Side_Effect_Free (Expression (N));
4428 -- A unary operator is side effect free if the operand
4429 -- is side effect free.
4432 return Side_Effect_Free (Right_Opnd (N));
4434 -- An unchecked type conversion is side effect free only if it
4435 -- is safe and its argument is side effect free.
4437 when N_Unchecked_Type_Conversion =>
4438 return Safe_Unchecked_Type_Conversion (N)
4439 and then Side_Effect_Free (Expression (N));
4441 -- An unchecked expression is side effect free if its expression
4442 -- is side effect free.
4444 when N_Unchecked_Expression =>
4445 return Side_Effect_Free (Expression (N));
4447 -- A literal is side effect free
4449 when N_Character_Literal |
4455 -- We consider that anything else has side effects. This is a bit
4456 -- crude, but we are pretty close for most common cases, and we
4457 -- are certainly correct (i.e. we never return True when the
4458 -- answer should be False).
4463 end Side_Effect_Free;
4465 -- A list is side effect free if all elements of the list are
4466 -- side effect free.
4468 function Side_Effect_Free (L : List_Id) return Boolean is
4472 if L = No_List or else L = Error_List then
4477 while Present (N) loop
4478 if not Side_Effect_Free (N) then
4487 end Side_Effect_Free;
4489 -------------------------
4490 -- Within_In_Parameter --
4491 -------------------------
4493 function Within_In_Parameter (N : Node_Id) return Boolean is
4495 if not Comes_From_Source (N) then
4498 elsif Is_Entity_Name (N) then
4500 Ekind (Entity (N)) = E_In_Parameter;
4502 elsif Nkind (N) = N_Indexed_Component
4503 or else Nkind (N) = N_Selected_Component
4505 return Within_In_Parameter (Prefix (N));
4510 end Within_In_Parameter;
4512 -- Start of processing for Remove_Side_Effects
4515 -- If we are side effect free already or expansion is disabled,
4516 -- there is nothing to do.
4518 if Side_Effect_Free (Exp) or else not Expander_Active then
4522 -- All this must not have any checks
4524 Scope_Suppress := (others => True);
4526 -- If it is a scalar type and we need to capture the value, just
4527 -- make a copy. Likewise for a function call. And if we have a
4528 -- volatile variable and Nam_Req is not set (see comments above
4529 -- for Side_Effect_Free).
4531 if Is_Elementary_Type (Exp_Type)
4532 and then (Variable_Ref
4533 or else Nkind (Exp) = N_Function_Call
4534 or else (not Name_Req
4535 and then Is_Entity_Name (Exp)
4536 and then Treat_As_Volatile (Entity (Exp))))
4539 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4540 Set_Etype (Def_Id, Exp_Type);
4541 Res := New_Reference_To (Def_Id, Loc);
4544 Make_Object_Declaration (Loc,
4545 Defining_Identifier => Def_Id,
4546 Object_Definition => New_Reference_To (Exp_Type, Loc),
4547 Constant_Present => True,
4548 Expression => Relocate_Node (Exp));
4550 Set_Assignment_OK (E);
4551 Insert_Action (Exp, E);
4553 -- If the expression has the form v.all then we can just capture
4554 -- the pointer, and then do an explicit dereference on the result.
4556 elsif Nkind (Exp) = N_Explicit_Dereference then
4558 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4560 Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc));
4563 Make_Object_Declaration (Loc,
4564 Defining_Identifier => Def_Id,
4565 Object_Definition =>
4566 New_Reference_To (Etype (Prefix (Exp)), Loc),
4567 Constant_Present => True,
4568 Expression => Relocate_Node (Prefix (Exp))));
4570 -- Similar processing for an unchecked conversion of an expression
4571 -- of the form v.all, where we want the same kind of treatment.
4573 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4574 and then Nkind (Expression (Exp)) = N_Explicit_Dereference
4576 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4577 Scope_Suppress := Svg_Suppress;
4580 -- If this is a type conversion, leave the type conversion and remove
4581 -- the side effects in the expression. This is important in several
4582 -- circumstances: for change of representations, and also when this
4583 -- is a view conversion to a smaller object, where gigi can end up
4584 -- creating its own temporary of the wrong size.
4586 elsif Nkind (Exp) = N_Type_Conversion then
4587 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4588 Scope_Suppress := Svg_Suppress;
4591 -- If this is an unchecked conversion that Gigi can't handle, make
4592 -- a copy or a use a renaming to capture the value.
4594 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4595 and then not Safe_Unchecked_Type_Conversion (Exp)
4597 if CW_Or_Controlled_Type (Exp_Type) then
4599 -- Use a renaming to capture the expression, rather than create
4600 -- a controlled temporary.
4602 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4603 Res := New_Reference_To (Def_Id, Loc);
4606 Make_Object_Renaming_Declaration (Loc,
4607 Defining_Identifier => Def_Id,
4608 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4609 Name => Relocate_Node (Exp)));
4612 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4613 Set_Etype (Def_Id, Exp_Type);
4614 Res := New_Reference_To (Def_Id, Loc);
4617 Make_Object_Declaration (Loc,
4618 Defining_Identifier => Def_Id,
4619 Object_Definition => New_Reference_To (Exp_Type, Loc),
4620 Constant_Present => not Is_Variable (Exp),
4621 Expression => Relocate_Node (Exp));
4623 Set_Assignment_OK (E);
4624 Insert_Action (Exp, E);
4627 -- For expressions that denote objects, we can use a renaming scheme.
4628 -- We skip using this if we have a volatile variable and we do not
4629 -- have Nam_Req set true (see comments above for Side_Effect_Free).
4631 elsif Is_Object_Reference (Exp)
4632 and then Nkind (Exp) /= N_Function_Call
4634 or else not Is_Entity_Name (Exp)
4635 or else not Treat_As_Volatile (Entity (Exp)))
4637 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4639 if Nkind (Exp) = N_Selected_Component
4640 and then Nkind (Prefix (Exp)) = N_Function_Call
4641 and then Is_Array_Type (Exp_Type)
4643 -- Avoid generating a variable-sized temporary, by generating
4644 -- the renaming declaration just for the function call. The
4645 -- transformation could be refined to apply only when the array
4646 -- component is constrained by a discriminant???
4649 Make_Selected_Component (Loc,
4650 Prefix => New_Occurrence_Of (Def_Id, Loc),
4651 Selector_Name => Selector_Name (Exp));
4654 Make_Object_Renaming_Declaration (Loc,
4655 Defining_Identifier => Def_Id,
4657 New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc),
4658 Name => Relocate_Node (Prefix (Exp))));
4661 Res := New_Reference_To (Def_Id, Loc);
4664 Make_Object_Renaming_Declaration (Loc,
4665 Defining_Identifier => Def_Id,
4666 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4667 Name => Relocate_Node (Exp)));
4671 -- If this is a packed reference, or a selected component with a
4672 -- non-standard representation, a reference to the temporary will
4673 -- be replaced by a copy of the original expression (see
4674 -- exp_ch2.Expand_Renaming). Otherwise the temporary must be
4675 -- elaborated by gigi, and is of course not to be replaced in-line
4676 -- by the expression it renames, which would defeat the purpose of
4677 -- removing the side-effect.
4679 if (Nkind (Exp) = N_Selected_Component
4680 or else Nkind (Exp) = N_Indexed_Component)
4681 and then Has_Non_Standard_Rep (Etype (Prefix (Exp)))
4685 Set_Is_Renaming_Of_Object (Def_Id, False);
4688 -- Otherwise we generate a reference to the value
4691 Ref_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
4694 Make_Full_Type_Declaration (Loc,
4695 Defining_Identifier => Ref_Type,
4697 Make_Access_To_Object_Definition (Loc,
4698 All_Present => True,
4699 Subtype_Indication =>
4700 New_Reference_To (Exp_Type, Loc)));
4703 Insert_Action (Exp, Ptr_Typ_Decl);
4705 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
4706 Set_Etype (Def_Id, Exp_Type);
4709 Make_Explicit_Dereference (Loc,
4710 Prefix => New_Reference_To (Def_Id, Loc));
4712 if Nkind (E) = N_Explicit_Dereference then
4713 New_Exp := Relocate_Node (Prefix (E));
4715 E := Relocate_Node (E);
4716 New_Exp := Make_Reference (Loc, E);
4719 if Is_Delayed_Aggregate (E) then
4721 -- The expansion of nested aggregates is delayed until the
4722 -- enclosing aggregate is expanded. As aggregates are often
4723 -- qualified, the predicate applies to qualified expressions
4724 -- as well, indicating that the enclosing aggregate has not
4725 -- been expanded yet. At this point the aggregate is part of
4726 -- a stand-alone declaration, and must be fully expanded.
4728 if Nkind (E) = N_Qualified_Expression then
4729 Set_Expansion_Delayed (Expression (E), False);
4730 Set_Analyzed (Expression (E), False);
4732 Set_Expansion_Delayed (E, False);
4735 Set_Analyzed (E, False);
4739 Make_Object_Declaration (Loc,
4740 Defining_Identifier => Def_Id,
4741 Object_Definition => New_Reference_To (Ref_Type, Loc),
4742 Expression => New_Exp));
4745 -- Preserve the Assignment_OK flag in all copies, since at least
4746 -- one copy may be used in a context where this flag must be set
4747 -- (otherwise why would the flag be set in the first place).
4749 Set_Assignment_OK (Res, Assignment_OK (Exp));
4751 -- Finally rewrite the original expression and we are done
4754 Analyze_And_Resolve (Exp, Exp_Type);
4755 Scope_Suppress := Svg_Suppress;
4756 end Remove_Side_Effects;
4758 ---------------------------
4759 -- Represented_As_Scalar --
4760 ---------------------------
4762 function Represented_As_Scalar (T : Entity_Id) return Boolean is
4763 UT : constant Entity_Id := Underlying_Type (T);
4765 return Is_Scalar_Type (UT)
4766 or else (Is_Bit_Packed_Array (UT)
4767 and then Is_Scalar_Type (Packed_Array_Type (UT)));
4768 end Represented_As_Scalar;
4770 ------------------------------------
4771 -- Safe_Unchecked_Type_Conversion --
4772 ------------------------------------
4774 -- Note: this function knows quite a bit about the exact requirements
4775 -- of Gigi with respect to unchecked type conversions, and its code
4776 -- must be coordinated with any changes in Gigi in this area.
4778 -- The above requirements should be documented in Sinfo ???
4780 function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
4785 Pexp : constant Node_Id := Parent (Exp);
4788 -- If the expression is the RHS of an assignment or object declaration
4789 -- we are always OK because there will always be a target.
4791 -- Object renaming declarations, (generated for view conversions of
4792 -- actuals in inlined calls), like object declarations, provide an
4793 -- explicit type, and are safe as well.
4795 if (Nkind (Pexp) = N_Assignment_Statement
4796 and then Expression (Pexp) = Exp)
4797 or else Nkind (Pexp) = N_Object_Declaration
4798 or else Nkind (Pexp) = N_Object_Renaming_Declaration
4802 -- If the expression is the prefix of an N_Selected_Component
4803 -- we should also be OK because GCC knows to look inside the
4804 -- conversion except if the type is discriminated. We assume
4805 -- that we are OK anyway if the type is not set yet or if it is
4806 -- controlled since we can't afford to introduce a temporary in
4809 elsif Nkind (Pexp) = N_Selected_Component
4810 and then Prefix (Pexp) = Exp
4812 if No (Etype (Pexp)) then
4816 not Has_Discriminants (Etype (Pexp))
4817 or else Is_Constrained (Etype (Pexp));
4821 -- Set the output type, this comes from Etype if it is set, otherwise
4822 -- we take it from the subtype mark, which we assume was already
4825 if Present (Etype (Exp)) then
4826 Otyp := Etype (Exp);
4828 Otyp := Entity (Subtype_Mark (Exp));
4831 -- The input type always comes from the expression, and we assume
4832 -- this is indeed always analyzed, so we can simply get the Etype.
4834 Ityp := Etype (Expression (Exp));
4836 -- Initialize alignments to unknown so far
4841 -- Replace a concurrent type by its corresponding record type
4842 -- and each type by its underlying type and do the tests on those.
4843 -- The original type may be a private type whose completion is a
4844 -- concurrent type, so find the underlying type first.
4846 if Present (Underlying_Type (Otyp)) then
4847 Otyp := Underlying_Type (Otyp);
4850 if Present (Underlying_Type (Ityp)) then
4851 Ityp := Underlying_Type (Ityp);
4854 if Is_Concurrent_Type (Otyp) then
4855 Otyp := Corresponding_Record_Type (Otyp);
4858 if Is_Concurrent_Type (Ityp) then
4859 Ityp := Corresponding_Record_Type (Ityp);
4862 -- If the base types are the same, we know there is no problem since
4863 -- this conversion will be a noop.
4865 if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
4868 -- Same if this is an upwards conversion of an untagged type, and there
4869 -- are no constraints involved (could be more general???)
4871 elsif Etype (Ityp) = Otyp
4872 and then not Is_Tagged_Type (Ityp)
4873 and then not Has_Discriminants (Ityp)
4874 and then No (First_Rep_Item (Base_Type (Ityp)))
4878 -- If the size of output type is known at compile time, there is
4879 -- never a problem. Note that unconstrained records are considered
4880 -- to be of known size, but we can't consider them that way here,
4881 -- because we are talking about the actual size of the object.
4883 -- We also make sure that in addition to the size being known, we do
4884 -- not have a case which might generate an embarrassingly large temp
4885 -- in stack checking mode.
4887 elsif Size_Known_At_Compile_Time (Otyp)
4889 (not Stack_Checking_Enabled
4890 or else not May_Generate_Large_Temp (Otyp))
4891 and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
4895 -- If either type is tagged, then we know the alignment is OK so
4896 -- Gigi will be able to use pointer punning.
4898 elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
4901 -- If either type is a limited record type, we cannot do a copy, so
4902 -- say safe since there's nothing else we can do.
4904 elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
4907 -- Conversions to and from packed array types are always ignored and
4910 elsif Is_Packed_Array_Type (Otyp)
4911 or else Is_Packed_Array_Type (Ityp)
4916 -- The only other cases known to be safe is if the input type's
4917 -- alignment is known to be at least the maximum alignment for the
4918 -- target or if both alignments are known and the output type's
4919 -- alignment is no stricter than the input's. We can use the alignment
4920 -- of the component type of an array if a type is an unpacked
4923 if Present (Alignment_Clause (Otyp)) then
4924 Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
4926 elsif Is_Array_Type (Otyp)
4927 and then Present (Alignment_Clause (Component_Type (Otyp)))
4929 Oalign := Expr_Value (Expression (Alignment_Clause
4930 (Component_Type (Otyp))));
4933 if Present (Alignment_Clause (Ityp)) then
4934 Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
4936 elsif Is_Array_Type (Ityp)
4937 and then Present (Alignment_Clause (Component_Type (Ityp)))
4939 Ialign := Expr_Value (Expression (Alignment_Clause
4940 (Component_Type (Ityp))));
4943 if Ialign /= No_Uint and then Ialign > Maximum_Alignment then
4946 elsif Ialign /= No_Uint and then Oalign /= No_Uint
4947 and then Ialign <= Oalign
4951 -- Otherwise, Gigi cannot handle this and we must make a temporary
4956 end Safe_Unchecked_Type_Conversion;
4958 ---------------------------------
4959 -- Set_Current_Value_Condition --
4960 ---------------------------------
4962 -- Note: the implementation of this procedure is very closely tied to the
4963 -- implementation of Get_Current_Value_Condition. Here we set required
4964 -- Current_Value fields, and in Get_Current_Value_Condition, we interpret
4965 -- them, so they must have a consistent view.
4967 procedure Set_Current_Value_Condition (Cnode : Node_Id) is
4969 procedure Set_Entity_Current_Value (N : Node_Id);
4970 -- If N is an entity reference, where the entity is of an appropriate
4971 -- kind, then set the current value of this entity to Cnode, unless
4972 -- there is already a definite value set there.
4974 procedure Set_Expression_Current_Value (N : Node_Id);
4975 -- If N is of an appropriate form, sets an appropriate entry in current
4976 -- value fields of relevant entities. Multiple entities can be affected
4977 -- in the case of an AND or AND THEN.
4979 ------------------------------
4980 -- Set_Entity_Current_Value --
4981 ------------------------------
4983 procedure Set_Entity_Current_Value (N : Node_Id) is
4985 if Is_Entity_Name (N) then
4987 Ent : constant Entity_Id := Entity (N);
4990 -- Don't capture if not safe to do so
4992 if not Safe_To_Capture_Value (N, Ent, Cond => True) then
4996 -- Here we have a case where the Current_Value field may
4997 -- need to be set. We set it if it is not already set to a
4998 -- compile time expression value.
5000 -- Note that this represents a decision that one condition
5001 -- blots out another previous one. That's certainly right
5002 -- if they occur at the same level. If the second one is
5003 -- nested, then the decision is neither right nor wrong (it
5004 -- would be equally OK to leave the outer one in place, or
5005 -- take the new inner one. Really we should record both, but
5006 -- our data structures are not that elaborate.
5008 if Nkind (Current_Value (Ent)) not in N_Subexpr then
5009 Set_Current_Value (Ent, Cnode);
5013 end Set_Entity_Current_Value;
5015 ----------------------------------
5016 -- Set_Expression_Current_Value --
5017 ----------------------------------
5019 procedure Set_Expression_Current_Value (N : Node_Id) is
5025 -- Loop to deal with (ignore for now) any NOT operators present. The
5026 -- presence of NOT operators will be handled properly when we call
5027 -- Get_Current_Value_Condition.
5029 while Nkind (Cond) = N_Op_Not loop
5030 Cond := Right_Opnd (Cond);
5033 -- For an AND or AND THEN, recursively process operands
5035 if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then
5036 Set_Expression_Current_Value (Left_Opnd (Cond));
5037 Set_Expression_Current_Value (Right_Opnd (Cond));
5041 -- Check possible relational operator
5043 if Nkind (Cond) in N_Op_Compare then
5044 if Compile_Time_Known_Value (Right_Opnd (Cond)) then
5045 Set_Entity_Current_Value (Left_Opnd (Cond));
5046 elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then
5047 Set_Entity_Current_Value (Right_Opnd (Cond));
5050 -- Check possible boolean variable reference
5053 Set_Entity_Current_Value (Cond);
5055 end Set_Expression_Current_Value;
5057 -- Start of processing for Set_Current_Value_Condition
5060 Set_Expression_Current_Value (Condition (Cnode));
5061 end Set_Current_Value_Condition;
5063 --------------------------
5064 -- Set_Elaboration_Flag --
5065 --------------------------
5067 procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
5068 Loc : constant Source_Ptr := Sloc (N);
5069 Ent : constant Entity_Id := Elaboration_Entity (Spec_Id);
5073 if Present (Ent) then
5075 -- Nothing to do if at the compilation unit level, because in this
5076 -- case the flag is set by the binder generated elaboration routine.
5078 if Nkind (Parent (N)) = N_Compilation_Unit then
5081 -- Here we do need to generate an assignment statement
5084 Check_Restriction (No_Elaboration_Code, N);
5086 Make_Assignment_Statement (Loc,
5087 Name => New_Occurrence_Of (Ent, Loc),
5088 Expression => New_Occurrence_Of (Standard_True, Loc));
5090 if Nkind (Parent (N)) = N_Subunit then
5091 Insert_After (Corresponding_Stub (Parent (N)), Asn);
5093 Insert_After (N, Asn);
5098 -- Kill current value indication. This is necessary because
5099 -- the tests of this flag are inserted out of sequence and must
5100 -- not pick up bogus indications of the wrong constant value.
5102 Set_Current_Value (Ent, Empty);
5105 end Set_Elaboration_Flag;
5107 ----------------------------
5108 -- Set_Renamed_Subprogram --
5109 ----------------------------
5111 procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is
5113 -- If input node is an identifier, we can just reset it
5115 if Nkind (N) = N_Identifier then
5116 Set_Chars (N, Chars (E));
5119 -- Otherwise we have to do a rewrite, preserving Comes_From_Source
5123 CS : constant Boolean := Comes_From_Source (N);
5125 Rewrite (N, Make_Identifier (Sloc (N), Chars => Chars (E)));
5127 Set_Comes_From_Source (N, CS);
5128 Set_Analyzed (N, True);
5131 end Set_Renamed_Subprogram;
5133 --------------------------
5134 -- Target_Has_Fixed_Ops --
5135 --------------------------
5137 Integer_Sized_Small : Ureal;
5138 -- Set to 2.0 ** -(Integer'Size - 1) the first time that this
5139 -- function is called (we don't want to compute it more than once!)
5141 Long_Integer_Sized_Small : Ureal;
5142 -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this
5143 -- functoin is called (we don't want to compute it more than once)
5145 First_Time_For_THFO : Boolean := True;
5146 -- Set to False after first call (if Fractional_Fixed_Ops_On_Target)
5148 function Target_Has_Fixed_Ops
5149 (Left_Typ : Entity_Id;
5150 Right_Typ : Entity_Id;
5151 Result_Typ : Entity_Id) return Boolean
5153 function Is_Fractional_Type (Typ : Entity_Id) return Boolean;
5154 -- Return True if the given type is a fixed-point type with a small
5155 -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have
5156 -- an absolute value less than 1.0. This is currently limited
5157 -- to fixed-point types that map to Integer or Long_Integer.
5159 ------------------------
5160 -- Is_Fractional_Type --
5161 ------------------------
5163 function Is_Fractional_Type (Typ : Entity_Id) return Boolean is
5165 if Esize (Typ) = Standard_Integer_Size then
5166 return Small_Value (Typ) = Integer_Sized_Small;
5168 elsif Esize (Typ) = Standard_Long_Integer_Size then
5169 return Small_Value (Typ) = Long_Integer_Sized_Small;
5174 end Is_Fractional_Type;
5176 -- Start of processing for Target_Has_Fixed_Ops
5179 -- Return False if Fractional_Fixed_Ops_On_Target is false
5181 if not Fractional_Fixed_Ops_On_Target then
5185 -- Here the target has Fractional_Fixed_Ops, if first time, compute
5186 -- standard constants used by Is_Fractional_Type.
5188 if First_Time_For_THFO then
5189 First_Time_For_THFO := False;
5191 Integer_Sized_Small :=
5194 Den => UI_From_Int (Standard_Integer_Size - 1),
5197 Long_Integer_Sized_Small :=
5200 Den => UI_From_Int (Standard_Long_Integer_Size - 1),
5204 -- Return True if target supports fixed-by-fixed multiply/divide
5205 -- for fractional fixed-point types (see Is_Fractional_Type) and
5206 -- the operand and result types are equivalent fractional types.
5208 return Is_Fractional_Type (Base_Type (Left_Typ))
5209 and then Is_Fractional_Type (Base_Type (Right_Typ))
5210 and then Is_Fractional_Type (Base_Type (Result_Typ))
5211 and then Esize (Left_Typ) = Esize (Right_Typ)
5212 and then Esize (Left_Typ) = Esize (Result_Typ);
5213 end Target_Has_Fixed_Ops;
5215 ------------------------------------------
5216 -- Type_May_Have_Bit_Aligned_Components --
5217 ------------------------------------------
5219 function Type_May_Have_Bit_Aligned_Components
5220 (Typ : Entity_Id) return Boolean
5223 -- Array type, check component type
5225 if Is_Array_Type (Typ) then
5227 Type_May_Have_Bit_Aligned_Components (Component_Type (Typ));
5229 -- Record type, check components
5231 elsif Is_Record_Type (Typ) then
5236 E := First_Component_Or_Discriminant (Typ);
5237 while Present (E) loop
5238 if Component_May_Be_Bit_Aligned (E)
5239 or else Type_May_Have_Bit_Aligned_Components (Etype (E))
5244 Next_Component_Or_Discriminant (E);
5250 -- Type other than array or record is always OK
5255 end Type_May_Have_Bit_Aligned_Components;
5257 ----------------------------
5258 -- Wrap_Cleanup_Procedure --
5259 ----------------------------
5261 procedure Wrap_Cleanup_Procedure (N : Node_Id) is
5262 Loc : constant Source_Ptr := Sloc (N);
5263 Stseq : constant Node_Id := Handled_Statement_Sequence (N);
5264 Stmts : constant List_Id := Statements (Stseq);
5267 if Abort_Allowed then
5268 Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
5269 Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));
5271 end Wrap_Cleanup_Procedure;