1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Debug; use Debug;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Aggr; use Exp_Aggr;
33 with Exp_Ch6; use Exp_Ch6;
34 with Exp_Ch7; use Exp_Ch7;
35 with Inline; use Inline;
36 with Itypes; use Itypes;
38 with Nlists; use Nlists;
39 with Nmake; use Nmake;
41 with Restrict; use Restrict;
42 with Rident; use Rident;
44 with Sem_Aux; use Sem_Aux;
45 with Sem_Ch8; use Sem_Ch8;
46 with Sem_Eval; use Sem_Eval;
47 with Sem_Res; use Sem_Res;
48 with Sem_Type; use Sem_Type;
49 with Sem_Util; use Sem_Util;
50 with Snames; use Snames;
51 with Stand; use Stand;
52 with Stringt; use Stringt;
53 with Targparm; use Targparm;
54 with Tbuild; use Tbuild;
55 with Ttypes; use Ttypes;
56 with Uintp; use Uintp;
57 with Urealp; use Urealp;
58 with Validsw; use Validsw;
60 package body Exp_Util is
62 -----------------------
63 -- Local Subprograms --
64 -----------------------
66 function Build_Task_Array_Image
70 Dyn : Boolean := False) return Node_Id;
71 -- Build function to generate the image string for a task that is an
72 -- array component, concatenating the images of each index. To avoid
73 -- storage leaks, the string is built with successive slice assignments.
74 -- The flag Dyn indicates whether this is called for the initialization
75 -- procedure of an array of tasks, or for the name of a dynamically
76 -- created task that is assigned to an indexed component.
78 function Build_Task_Image_Function
82 Res : Entity_Id) return Node_Id;
83 -- Common processing for Task_Array_Image and Task_Record_Image.
84 -- Build function body that computes image.
86 procedure Build_Task_Image_Prefix
95 -- Common processing for Task_Array_Image and Task_Record_Image.
96 -- Create local variables and assign prefix of name to result string.
98 function Build_Task_Record_Image
101 Dyn : Boolean := False) return Node_Id;
102 -- Build function to generate the image string for a task that is a
103 -- record component. Concatenate name of variable with that of selector.
104 -- The flag Dyn indicates whether this is called for the initialization
105 -- procedure of record with task components, or for a dynamically
106 -- created task that is assigned to a selected component.
108 function Make_CW_Equivalent_Type
110 E : Node_Id) return Entity_Id;
111 -- T is a class-wide type entity, E is the initial expression node that
112 -- constrains T in case such as: " X: T := E" or "new T'(E)"
113 -- This function returns the entity of the Equivalent type and inserts
114 -- on the fly the necessary declaration such as:
116 -- type anon is record
117 -- _parent : Root_Type (T); constrained with E discriminants (if any)
118 -- Extension : String (1 .. expr to match size of E);
121 -- This record is compatible with any object of the class of T thanks
122 -- to the first field and has the same size as E thanks to the second.
124 function Make_Literal_Range
126 Literal_Typ : Entity_Id) return Node_Id;
127 -- Produce a Range node whose bounds are:
128 -- Low_Bound (Literal_Type) ..
129 -- Low_Bound (Literal_Type) + (Length (Literal_Typ) - 1)
130 -- this is used for expanding declarations like X : String := "sdfgdfg";
132 -- If the index type of the target array is not integer, we generate:
133 -- Low_Bound (Literal_Type) ..
135 -- (Literal_Type'Pos (Low_Bound (Literal_Type))
136 -- + (Length (Literal_Typ) -1))
138 function Make_Non_Empty_Check
140 N : Node_Id) return Node_Id;
141 -- Produce a boolean expression checking that the unidimensional array
142 -- node N is not empty.
144 function New_Class_Wide_Subtype
146 N : Node_Id) return Entity_Id;
147 -- Create an implicit subtype of CW_Typ attached to node N
149 ----------------------
150 -- Adjust_Condition --
151 ----------------------
153 procedure Adjust_Condition (N : Node_Id) is
160 Loc : constant Source_Ptr := Sloc (N);
161 T : constant Entity_Id := Etype (N);
165 -- For now, we simply ignore a call where the argument has no
166 -- type (probably case of unanalyzed condition), or has a type
167 -- that is not Boolean. This is because this is a pretty marginal
168 -- piece of functionality, and violations of these rules are
169 -- likely to be truly marginal (how much code uses Fortran Logical
170 -- as the barrier to a protected entry?) and we do not want to
171 -- blow up existing programs. We can change this to an assertion
172 -- after 3.12a is released ???
174 if No (T) or else not Is_Boolean_Type (T) then
178 -- Apply validity checking if needed
180 if Validity_Checks_On and Validity_Check_Tests then
184 -- Immediate return if standard boolean, the most common case,
185 -- where nothing needs to be done.
187 if Base_Type (T) = Standard_Boolean then
191 -- Case of zero/non-zero semantics or non-standard enumeration
192 -- representation. In each case, we rewrite the node as:
194 -- ityp!(N) /= False'Enum_Rep
196 -- where ityp is an integer type with large enough size to hold
197 -- any value of type T.
199 if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then
200 if Esize (T) <= Esize (Standard_Integer) then
201 Ti := Standard_Integer;
203 Ti := Standard_Long_Long_Integer;
208 Left_Opnd => Unchecked_Convert_To (Ti, N),
210 Make_Attribute_Reference (Loc,
211 Attribute_Name => Name_Enum_Rep,
213 New_Occurrence_Of (First_Literal (T), Loc))));
214 Analyze_And_Resolve (N, Standard_Boolean);
217 Rewrite (N, Convert_To (Standard_Boolean, N));
218 Analyze_And_Resolve (N, Standard_Boolean);
221 end Adjust_Condition;
223 ------------------------
224 -- Adjust_Result_Type --
225 ------------------------
227 procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is
229 -- Ignore call if current type is not Standard.Boolean
231 if Etype (N) /= Standard_Boolean then
235 -- If result is already of correct type, nothing to do. Note that
236 -- this will get the most common case where everything has a type
237 -- of Standard.Boolean.
239 if Base_Type (T) = Standard_Boolean then
244 KP : constant Node_Kind := Nkind (Parent (N));
247 -- If result is to be used as a Condition in the syntax, no need
248 -- to convert it back, since if it was changed to Standard.Boolean
249 -- using Adjust_Condition, that is just fine for this usage.
251 if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then
254 -- If result is an operand of another logical operation, no need
255 -- to reset its type, since Standard.Boolean is just fine, and
256 -- such operations always do Adjust_Condition on their operands.
258 elsif KP in N_Op_Boolean
259 or else KP in N_Short_Circuit
260 or else KP = N_Op_Not
264 -- Otherwise we perform a conversion from the current type,
265 -- which must be Standard.Boolean, to the desired type.
269 Rewrite (N, Convert_To (T, N));
270 Analyze_And_Resolve (N, T);
274 end Adjust_Result_Type;
276 --------------------------
277 -- Append_Freeze_Action --
278 --------------------------
280 procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is
284 Ensure_Freeze_Node (T);
285 Fnode := Freeze_Node (T);
287 if No (Actions (Fnode)) then
288 Set_Actions (Fnode, New_List);
291 Append (N, Actions (Fnode));
292 end Append_Freeze_Action;
294 ---------------------------
295 -- Append_Freeze_Actions --
296 ---------------------------
298 procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is
299 Fnode : constant Node_Id := Freeze_Node (T);
306 if No (Actions (Fnode)) then
307 Set_Actions (Fnode, L);
309 Append_List (L, Actions (Fnode));
312 end Append_Freeze_Actions;
314 ------------------------
315 -- Build_Runtime_Call --
316 ------------------------
318 function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is
320 -- If entity is not available, we can skip making the call (this avoids
321 -- junk duplicated error messages in a number of cases).
323 if not RTE_Available (RE) then
324 return Make_Null_Statement (Loc);
327 Make_Procedure_Call_Statement (Loc,
328 Name => New_Reference_To (RTE (RE), Loc));
330 end Build_Runtime_Call;
332 ----------------------------
333 -- Build_Task_Array_Image --
334 ----------------------------
336 -- This function generates the body for a function that constructs the
337 -- image string for a task that is an array component. The function is
338 -- local to the init proc for the array type, and is called for each one
339 -- of the components. The constructed image has the form of an indexed
340 -- component, whose prefix is the outer variable of the array type.
341 -- The n-dimensional array type has known indices Index, Index2...
342 -- Id_Ref is an indexed component form created by the enclosing init proc.
343 -- Its successive indices are Val1, Val2, ... which are the loop variables
344 -- in the loops that call the individual task init proc on each component.
346 -- The generated function has the following structure:
348 -- function F return String is
349 -- Pref : string renames Task_Name;
350 -- T1 : String := Index1'Image (Val1);
352 -- Tn : String := indexn'image (Valn);
353 -- Len : Integer := T1'Length + ... + Tn'Length + n + 1;
354 -- -- Len includes commas and the end parentheses.
355 -- Res : String (1..Len);
356 -- Pos : Integer := Pref'Length;
359 -- Res (1 .. Pos) := Pref;
363 -- Res (Pos .. Pos + T1'Length - 1) := T1;
364 -- Pos := Pos + T1'Length;
368 -- Res (Pos .. Pos + Tn'Length - 1) := Tn;
374 -- Needless to say, multidimensional arrays of tasks are rare enough
375 -- that the bulkiness of this code is not really a concern.
377 function Build_Task_Array_Image
381 Dyn : Boolean := False) return Node_Id
383 Dims : constant Nat := Number_Dimensions (A_Type);
384 -- Number of dimensions for array of tasks
386 Temps : array (1 .. Dims) of Entity_Id;
387 -- Array of temporaries to hold string for each index
393 -- Total length of generated name
396 -- Running index for substring assignments
398 Pref : constant Entity_Id := Make_Temporary (Loc, 'P');
399 -- Name of enclosing variable, prefix of resulting name
402 -- String to hold result
405 -- Value of successive indices
408 -- Expression to compute total size of string
411 -- Entity for name at one index position
413 Decls : constant List_Id := New_List;
414 Stats : constant List_Id := New_List;
417 -- For a dynamic task, the name comes from the target variable.
418 -- For a static one it is a formal of the enclosing init proc.
421 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
423 Make_Object_Declaration (Loc,
424 Defining_Identifier => Pref,
425 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
427 Make_String_Literal (Loc,
428 Strval => String_From_Name_Buffer)));
432 Make_Object_Renaming_Declaration (Loc,
433 Defining_Identifier => Pref,
434 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
435 Name => Make_Identifier (Loc, Name_uTask_Name)));
438 Indx := First_Index (A_Type);
439 Val := First (Expressions (Id_Ref));
441 for J in 1 .. Dims loop
442 T := Make_Temporary (Loc, 'T');
446 Make_Object_Declaration (Loc,
447 Defining_Identifier => T,
448 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
450 Make_Attribute_Reference (Loc,
451 Attribute_Name => Name_Image,
452 Prefix => New_Occurrence_Of (Etype (Indx), Loc),
453 Expressions => New_List (New_Copy_Tree (Val)))));
459 Sum := Make_Integer_Literal (Loc, Dims + 1);
465 Make_Attribute_Reference (Loc,
466 Attribute_Name => Name_Length,
468 New_Occurrence_Of (Pref, Loc),
469 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
471 for J in 1 .. Dims loop
476 Make_Attribute_Reference (Loc,
477 Attribute_Name => Name_Length,
479 New_Occurrence_Of (Temps (J), Loc),
480 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
483 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
485 Set_Character_Literal_Name (Char_Code (Character'Pos ('(')));
488 Make_Assignment_Statement (Loc,
489 Name => Make_Indexed_Component (Loc,
490 Prefix => New_Occurrence_Of (Res, Loc),
491 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
493 Make_Character_Literal (Loc,
495 Char_Literal_Value =>
496 UI_From_Int (Character'Pos ('(')))));
499 Make_Assignment_Statement (Loc,
500 Name => New_Occurrence_Of (Pos, Loc),
503 Left_Opnd => New_Occurrence_Of (Pos, Loc),
504 Right_Opnd => Make_Integer_Literal (Loc, 1))));
506 for J in 1 .. Dims loop
509 Make_Assignment_Statement (Loc,
510 Name => Make_Slice (Loc,
511 Prefix => New_Occurrence_Of (Res, Loc),
514 Low_Bound => New_Occurrence_Of (Pos, Loc),
515 High_Bound => Make_Op_Subtract (Loc,
518 Left_Opnd => New_Occurrence_Of (Pos, Loc),
520 Make_Attribute_Reference (Loc,
521 Attribute_Name => Name_Length,
523 New_Occurrence_Of (Temps (J), Loc),
525 New_List (Make_Integer_Literal (Loc, 1)))),
526 Right_Opnd => Make_Integer_Literal (Loc, 1)))),
528 Expression => New_Occurrence_Of (Temps (J), Loc)));
532 Make_Assignment_Statement (Loc,
533 Name => New_Occurrence_Of (Pos, Loc),
536 Left_Opnd => New_Occurrence_Of (Pos, Loc),
538 Make_Attribute_Reference (Loc,
539 Attribute_Name => Name_Length,
540 Prefix => New_Occurrence_Of (Temps (J), Loc),
542 New_List (Make_Integer_Literal (Loc, 1))))));
544 Set_Character_Literal_Name (Char_Code (Character'Pos (',')));
547 Make_Assignment_Statement (Loc,
548 Name => Make_Indexed_Component (Loc,
549 Prefix => New_Occurrence_Of (Res, Loc),
550 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
552 Make_Character_Literal (Loc,
554 Char_Literal_Value =>
555 UI_From_Int (Character'Pos (',')))));
558 Make_Assignment_Statement (Loc,
559 Name => New_Occurrence_Of (Pos, Loc),
562 Left_Opnd => New_Occurrence_Of (Pos, Loc),
563 Right_Opnd => Make_Integer_Literal (Loc, 1))));
567 Set_Character_Literal_Name (Char_Code (Character'Pos (')')));
570 Make_Assignment_Statement (Loc,
571 Name => Make_Indexed_Component (Loc,
572 Prefix => New_Occurrence_Of (Res, Loc),
573 Expressions => New_List (New_Occurrence_Of (Len, Loc))),
575 Make_Character_Literal (Loc,
577 Char_Literal_Value =>
578 UI_From_Int (Character'Pos (')')))));
579 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
580 end Build_Task_Array_Image;
582 ----------------------------
583 -- Build_Task_Image_Decls --
584 ----------------------------
586 function Build_Task_Image_Decls
590 In_Init_Proc : Boolean := False) return List_Id
592 Decls : constant List_Id := New_List;
593 T_Id : Entity_Id := Empty;
595 Expr : Node_Id := Empty;
596 Fun : Node_Id := Empty;
597 Is_Dyn : constant Boolean :=
598 Nkind (Parent (Id_Ref)) = N_Assignment_Statement
600 Nkind (Expression (Parent (Id_Ref))) = N_Allocator;
603 -- If Discard_Names or No_Implicit_Heap_Allocations are in effect,
604 -- generate a dummy declaration only.
606 if Restriction_Active (No_Implicit_Heap_Allocations)
607 or else Global_Discard_Names
609 T_Id := Make_Temporary (Loc, 'J');
614 Make_Object_Declaration (Loc,
615 Defining_Identifier => T_Id,
616 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
618 Make_String_Literal (Loc,
619 Strval => String_From_Name_Buffer)));
622 if Nkind (Id_Ref) = N_Identifier
623 or else Nkind (Id_Ref) = N_Defining_Identifier
625 -- For a simple variable, the image of the task is built from
626 -- the name of the variable. To avoid possible conflict with
627 -- the anonymous type created for a single protected object,
628 -- add a numeric suffix.
631 Make_Defining_Identifier (Loc,
632 New_External_Name (Chars (Id_Ref), 'T', 1));
634 Get_Name_String (Chars (Id_Ref));
637 Make_String_Literal (Loc,
638 Strval => String_From_Name_Buffer);
640 elsif Nkind (Id_Ref) = N_Selected_Component then
642 Make_Defining_Identifier (Loc,
643 New_External_Name (Chars (Selector_Name (Id_Ref)), 'T'));
644 Fun := Build_Task_Record_Image (Loc, Id_Ref, Is_Dyn);
646 elsif Nkind (Id_Ref) = N_Indexed_Component then
648 Make_Defining_Identifier (Loc,
649 New_External_Name (Chars (A_Type), 'N'));
651 Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn);
655 if Present (Fun) then
657 Expr := Make_Function_Call (Loc,
658 Name => New_Occurrence_Of (Defining_Entity (Fun), Loc));
660 if not In_Init_Proc and then VM_Target = No_VM then
661 Set_Uses_Sec_Stack (Defining_Entity (Fun));
665 Decl := Make_Object_Declaration (Loc,
666 Defining_Identifier => T_Id,
667 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
668 Constant_Present => True,
671 Append (Decl, Decls);
673 end Build_Task_Image_Decls;
675 -------------------------------
676 -- Build_Task_Image_Function --
677 -------------------------------
679 function Build_Task_Image_Function
683 Res : Entity_Id) return Node_Id
689 Make_Simple_Return_Statement (Loc,
690 Expression => New_Occurrence_Of (Res, Loc)));
692 Spec := Make_Function_Specification (Loc,
693 Defining_Unit_Name => Make_Temporary (Loc, 'F'),
694 Result_Definition => New_Occurrence_Of (Standard_String, Loc));
696 -- Calls to 'Image use the secondary stack, which must be cleaned
697 -- up after the task name is built.
699 return Make_Subprogram_Body (Loc,
700 Specification => Spec,
701 Declarations => Decls,
702 Handled_Statement_Sequence =>
703 Make_Handled_Sequence_Of_Statements (Loc, Statements => Stats));
704 end Build_Task_Image_Function;
706 -----------------------------
707 -- Build_Task_Image_Prefix --
708 -----------------------------
710 procedure Build_Task_Image_Prefix
721 Len := Make_Temporary (Loc, 'L', Sum);
724 Make_Object_Declaration (Loc,
725 Defining_Identifier => Len,
726 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
729 Res := Make_Temporary (Loc, 'R');
732 Make_Object_Declaration (Loc,
733 Defining_Identifier => Res,
735 Make_Subtype_Indication (Loc,
736 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
738 Make_Index_Or_Discriminant_Constraint (Loc,
742 Low_Bound => Make_Integer_Literal (Loc, 1),
743 High_Bound => New_Occurrence_Of (Len, Loc)))))));
745 Pos := Make_Temporary (Loc, 'P');
748 Make_Object_Declaration (Loc,
749 Defining_Identifier => Pos,
750 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc)));
752 -- Pos := Prefix'Length;
755 Make_Assignment_Statement (Loc,
756 Name => New_Occurrence_Of (Pos, Loc),
758 Make_Attribute_Reference (Loc,
759 Attribute_Name => Name_Length,
760 Prefix => New_Occurrence_Of (Prefix, Loc),
761 Expressions => New_List (Make_Integer_Literal (Loc, 1)))));
763 -- Res (1 .. Pos) := Prefix;
766 Make_Assignment_Statement (Loc,
769 Prefix => New_Occurrence_Of (Res, Loc),
772 Low_Bound => Make_Integer_Literal (Loc, 1),
773 High_Bound => New_Occurrence_Of (Pos, Loc))),
775 Expression => New_Occurrence_Of (Prefix, Loc)));
778 Make_Assignment_Statement (Loc,
779 Name => New_Occurrence_Of (Pos, Loc),
782 Left_Opnd => New_Occurrence_Of (Pos, Loc),
783 Right_Opnd => Make_Integer_Literal (Loc, 1))));
784 end Build_Task_Image_Prefix;
786 -----------------------------
787 -- Build_Task_Record_Image --
788 -----------------------------
790 function Build_Task_Record_Image
793 Dyn : Boolean := False) return Node_Id
796 -- Total length of generated name
802 -- String to hold result
804 Pref : constant Entity_Id := Make_Temporary (Loc, 'P');
805 -- Name of enclosing variable, prefix of resulting name
808 -- Expression to compute total size of string
811 -- Entity for selector name
813 Decls : constant List_Id := New_List;
814 Stats : constant List_Id := New_List;
817 -- For a dynamic task, the name comes from the target variable. For a
818 -- static one it is a formal of the enclosing init proc.
821 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
823 Make_Object_Declaration (Loc,
824 Defining_Identifier => Pref,
825 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
827 Make_String_Literal (Loc,
828 Strval => String_From_Name_Buffer)));
832 Make_Object_Renaming_Declaration (Loc,
833 Defining_Identifier => Pref,
834 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
835 Name => Make_Identifier (Loc, Name_uTask_Name)));
838 Sel := Make_Temporary (Loc, 'S');
840 Get_Name_String (Chars (Selector_Name (Id_Ref)));
843 Make_Object_Declaration (Loc,
844 Defining_Identifier => Sel,
845 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
847 Make_String_Literal (Loc,
848 Strval => String_From_Name_Buffer)));
850 Sum := Make_Integer_Literal (Loc, Nat (Name_Len + 1));
856 Make_Attribute_Reference (Loc,
857 Attribute_Name => Name_Length,
859 New_Occurrence_Of (Pref, Loc),
860 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
862 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
864 Set_Character_Literal_Name (Char_Code (Character'Pos ('.')));
869 Make_Assignment_Statement (Loc,
870 Name => Make_Indexed_Component (Loc,
871 Prefix => New_Occurrence_Of (Res, Loc),
872 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
874 Make_Character_Literal (Loc,
876 Char_Literal_Value =>
877 UI_From_Int (Character'Pos ('.')))));
880 Make_Assignment_Statement (Loc,
881 Name => New_Occurrence_Of (Pos, Loc),
884 Left_Opnd => New_Occurrence_Of (Pos, Loc),
885 Right_Opnd => Make_Integer_Literal (Loc, 1))));
887 -- Res (Pos .. Len) := Selector;
890 Make_Assignment_Statement (Loc,
891 Name => Make_Slice (Loc,
892 Prefix => New_Occurrence_Of (Res, Loc),
895 Low_Bound => New_Occurrence_Of (Pos, Loc),
896 High_Bound => New_Occurrence_Of (Len, Loc))),
897 Expression => New_Occurrence_Of (Sel, Loc)));
899 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
900 end Build_Task_Record_Image;
902 ----------------------------------
903 -- Component_May_Be_Bit_Aligned --
904 ----------------------------------
906 function Component_May_Be_Bit_Aligned (Comp : Entity_Id) return Boolean is
910 -- If no component clause, then everything is fine, since the back end
911 -- never bit-misaligns by default, even if there is a pragma Packed for
914 if No (Comp) or else No (Component_Clause (Comp)) then
918 UT := Underlying_Type (Etype (Comp));
920 -- It is only array and record types that cause trouble
922 if not Is_Record_Type (UT)
923 and then not Is_Array_Type (UT)
927 -- If we know that we have a small (64 bits or less) record or small
928 -- bit-packed array, then everything is fine, since the back end can
929 -- handle these cases correctly.
931 elsif Esize (Comp) <= 64
932 and then (Is_Record_Type (UT)
933 or else Is_Bit_Packed_Array (UT))
937 -- Otherwise if the component is not byte aligned, we know we have the
938 -- nasty unaligned case.
940 elsif Normalized_First_Bit (Comp) /= Uint_0
941 or else Esize (Comp) mod System_Storage_Unit /= Uint_0
945 -- If we are large and byte aligned, then OK at this level
950 end Component_May_Be_Bit_Aligned;
952 -----------------------------------
953 -- Corresponding_Runtime_Package --
954 -----------------------------------
956 function Corresponding_Runtime_Package (Typ : Entity_Id) return RTU_Id is
957 Pkg_Id : RTU_Id := RTU_Null;
960 pragma Assert (Is_Concurrent_Type (Typ));
962 if Ekind (Typ) in Protected_Kind then
964 or else Has_Interrupt_Handler (Typ)
965 or else (Has_Attach_Handler (Typ)
966 and then not Restricted_Profile)
968 -- A protected type without entries that covers an interface and
969 -- overrides the abstract routines with protected procedures is
970 -- considered equivalent to a protected type with entries in the
971 -- context of dispatching select statements. It is sufficient to
972 -- check for the presence of an interface list in the declaration
973 -- node to recognize this case.
975 or else Present (Interface_List (Parent (Typ)))
978 or else Restriction_Active (No_Entry_Queue) = False
979 or else Number_Entries (Typ) > 1
980 or else (Has_Attach_Handler (Typ)
981 and then not Restricted_Profile)
983 Pkg_Id := System_Tasking_Protected_Objects_Entries;
985 Pkg_Id := System_Tasking_Protected_Objects_Single_Entry;
989 Pkg_Id := System_Tasking_Protected_Objects;
994 end Corresponding_Runtime_Package;
996 -------------------------------
997 -- Convert_To_Actual_Subtype --
998 -------------------------------
1000 procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is
1004 Act_ST := Get_Actual_Subtype (Exp);
1006 if Act_ST = Etype (Exp) then
1011 Convert_To (Act_ST, Relocate_Node (Exp)));
1012 Analyze_And_Resolve (Exp, Act_ST);
1014 end Convert_To_Actual_Subtype;
1016 -----------------------------------
1017 -- Current_Sem_Unit_Declarations --
1018 -----------------------------------
1020 function Current_Sem_Unit_Declarations return List_Id is
1021 U : Node_Id := Unit (Cunit (Current_Sem_Unit));
1025 -- If the current unit is a package body, locate the visible
1026 -- declarations of the package spec.
1028 if Nkind (U) = N_Package_Body then
1029 U := Unit (Library_Unit (Cunit (Current_Sem_Unit)));
1032 if Nkind (U) = N_Package_Declaration then
1033 U := Specification (U);
1034 Decls := Visible_Declarations (U);
1038 Set_Visible_Declarations (U, Decls);
1042 Decls := Declarations (U);
1046 Set_Declarations (U, Decls);
1051 end Current_Sem_Unit_Declarations;
1053 -----------------------
1054 -- Duplicate_Subexpr --
1055 -----------------------
1057 function Duplicate_Subexpr
1059 Name_Req : Boolean := False) return Node_Id
1062 Remove_Side_Effects (Exp, Name_Req);
1063 return New_Copy_Tree (Exp);
1064 end Duplicate_Subexpr;
1066 ---------------------------------
1067 -- Duplicate_Subexpr_No_Checks --
1068 ---------------------------------
1070 function Duplicate_Subexpr_No_Checks
1072 Name_Req : Boolean := False) return Node_Id
1077 Remove_Side_Effects (Exp, Name_Req);
1078 New_Exp := New_Copy_Tree (Exp);
1079 Remove_Checks (New_Exp);
1081 end Duplicate_Subexpr_No_Checks;
1083 -----------------------------------
1084 -- Duplicate_Subexpr_Move_Checks --
1085 -----------------------------------
1087 function Duplicate_Subexpr_Move_Checks
1089 Name_Req : Boolean := False) return Node_Id
1094 Remove_Side_Effects (Exp, Name_Req);
1095 New_Exp := New_Copy_Tree (Exp);
1096 Remove_Checks (Exp);
1098 end Duplicate_Subexpr_Move_Checks;
1100 --------------------
1101 -- Ensure_Defined --
1102 --------------------
1104 procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is
1108 -- An itype reference must only be created if this is a local itype, so
1109 -- that gigi can elaborate it on the proper objstack.
1112 and then Scope (Typ) = Current_Scope
1114 IR := Make_Itype_Reference (Sloc (N));
1115 Set_Itype (IR, Typ);
1116 Insert_Action (N, IR);
1120 --------------------
1121 -- Entry_Names_OK --
1122 --------------------
1124 function Entry_Names_OK return Boolean is
1127 not Restricted_Profile
1128 and then not Global_Discard_Names
1129 and then not Restriction_Active (No_Implicit_Heap_Allocations)
1130 and then not Restriction_Active (No_Local_Allocators);
1133 ---------------------
1134 -- Evolve_And_Then --
1135 ---------------------
1137 procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is
1143 Make_And_Then (Sloc (Cond1),
1145 Right_Opnd => Cond1);
1147 end Evolve_And_Then;
1149 --------------------
1150 -- Evolve_Or_Else --
1151 --------------------
1153 procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is
1159 Make_Or_Else (Sloc (Cond1),
1161 Right_Opnd => Cond1);
1165 ------------------------------
1166 -- Expand_Subtype_From_Expr --
1167 ------------------------------
1169 -- This function is applicable for both static and dynamic allocation of
1170 -- objects which are constrained by an initial expression. Basically it
1171 -- transforms an unconstrained subtype indication into a constrained one.
1172 -- The expression may also be transformed in certain cases in order to
1173 -- avoid multiple evaluation. In the static allocation case, the general
1178 -- is transformed into
1180 -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr;
1182 -- Here are the main cases :
1184 -- <if Expr is a Slice>
1185 -- Val : T ([Index_Subtype (Expr)]) := Expr;
1187 -- <elsif Expr is a String Literal>
1188 -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
1190 -- <elsif Expr is Constrained>
1191 -- subtype T is Type_Of_Expr
1194 -- <elsif Expr is an entity_name>
1195 -- Val : T (constraints taken from Expr) := Expr;
1198 -- type Axxx is access all T;
1199 -- Rval : Axxx := Expr'ref;
1200 -- Val : T (constraints taken from Rval) := Rval.all;
1202 -- ??? note: when the Expression is allocated in the secondary stack
1203 -- we could use it directly instead of copying it by declaring
1204 -- Val : T (...) renames Rval.all
1206 procedure Expand_Subtype_From_Expr
1208 Unc_Type : Entity_Id;
1209 Subtype_Indic : Node_Id;
1212 Loc : constant Source_Ptr := Sloc (N);
1213 Exp_Typ : constant Entity_Id := Etype (Exp);
1217 -- In general we cannot build the subtype if expansion is disabled,
1218 -- because internal entities may not have been defined. However, to
1219 -- avoid some cascaded errors, we try to continue when the expression is
1220 -- an array (or string), because it is safe to compute the bounds. It is
1221 -- in fact required to do so even in a generic context, because there
1222 -- may be constants that depend on the bounds of a string literal, both
1223 -- standard string types and more generally arrays of characters.
1225 if not Expander_Active
1226 and then (No (Etype (Exp))
1227 or else not Is_String_Type (Etype (Exp)))
1232 if Nkind (Exp) = N_Slice then
1234 Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ));
1237 Rewrite (Subtype_Indic,
1238 Make_Subtype_Indication (Loc,
1239 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1241 Make_Index_Or_Discriminant_Constraint (Loc,
1242 Constraints => New_List
1243 (New_Reference_To (Slice_Type, Loc)))));
1245 -- This subtype indication may be used later for constraint checks
1246 -- we better make sure that if a variable was used as a bound of
1247 -- of the original slice, its value is frozen.
1249 Force_Evaluation (Low_Bound (Scalar_Range (Slice_Type)));
1250 Force_Evaluation (High_Bound (Scalar_Range (Slice_Type)));
1253 elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then
1254 Rewrite (Subtype_Indic,
1255 Make_Subtype_Indication (Loc,
1256 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1258 Make_Index_Or_Discriminant_Constraint (Loc,
1259 Constraints => New_List (
1260 Make_Literal_Range (Loc,
1261 Literal_Typ => Exp_Typ)))));
1263 elsif Is_Constrained (Exp_Typ)
1264 and then not Is_Class_Wide_Type (Unc_Type)
1266 if Is_Itype (Exp_Typ) then
1268 -- Within an initialization procedure, a selected component
1269 -- denotes a component of the enclosing record, and it appears
1270 -- as an actual in a call to its own initialization procedure.
1271 -- If this component depends on the outer discriminant, we must
1272 -- generate the proper actual subtype for it.
1274 if Nkind (Exp) = N_Selected_Component
1275 and then Within_Init_Proc
1278 Decl : constant Node_Id :=
1279 Build_Actual_Subtype_Of_Component (Exp_Typ, Exp);
1281 if Present (Decl) then
1282 Insert_Action (N, Decl);
1283 T := Defining_Identifier (Decl);
1289 -- No need to generate a new one (new what???)
1296 T := Make_Temporary (Loc, 'T');
1299 Make_Subtype_Declaration (Loc,
1300 Defining_Identifier => T,
1301 Subtype_Indication => New_Reference_To (Exp_Typ, Loc)));
1303 -- This type is marked as an itype even though it has an
1304 -- explicit declaration because otherwise it can be marked
1305 -- with Is_Generic_Actual_Type and generate spurious errors.
1306 -- (see sem_ch8.Analyze_Package_Renaming and sem_type.covers)
1309 Set_Associated_Node_For_Itype (T, Exp);
1312 Rewrite (Subtype_Indic, New_Reference_To (T, Loc));
1314 -- Nothing needs to be done for private types with unknown discriminants
1315 -- if the underlying type is not an unconstrained composite type or it
1316 -- is an unchecked union.
1318 elsif Is_Private_Type (Unc_Type)
1319 and then Has_Unknown_Discriminants (Unc_Type)
1320 and then (not Is_Composite_Type (Underlying_Type (Unc_Type))
1321 or else Is_Constrained (Underlying_Type (Unc_Type))
1322 or else Is_Unchecked_Union (Underlying_Type (Unc_Type)))
1326 -- Case of derived type with unknown discriminants where the parent type
1327 -- also has unknown discriminants.
1329 elsif Is_Record_Type (Unc_Type)
1330 and then not Is_Class_Wide_Type (Unc_Type)
1331 and then Has_Unknown_Discriminants (Unc_Type)
1332 and then Has_Unknown_Discriminants (Underlying_Type (Unc_Type))
1334 -- Nothing to be done if no underlying record view available
1336 if No (Underlying_Record_View (Unc_Type)) then
1339 -- Otherwise use the Underlying_Record_View to create the proper
1340 -- constrained subtype for an object of a derived type with unknown
1344 Remove_Side_Effects (Exp);
1345 Rewrite (Subtype_Indic,
1346 Make_Subtype_From_Expr (Exp, Underlying_Record_View (Unc_Type)));
1349 -- Renamings of class-wide interface types require no equivalent
1350 -- constrained type declarations because we only need to reference
1351 -- the tag component associated with the interface.
1354 and then Nkind (N) = N_Object_Renaming_Declaration
1355 and then Is_Interface (Unc_Type)
1357 pragma Assert (Is_Class_Wide_Type (Unc_Type));
1360 -- In Ada95 nothing to be done if the type of the expression is limited,
1361 -- because in this case the expression cannot be copied, and its use can
1362 -- only be by reference.
1364 -- In Ada2005, the context can be an object declaration whose expression
1365 -- is a function that returns in place. If the nominal subtype has
1366 -- unknown discriminants, the call still provides constraints on the
1367 -- object, and we have to create an actual subtype from it.
1369 -- If the type is class-wide, the expression is dynamically tagged and
1370 -- we do not create an actual subtype either. Ditto for an interface.
1372 elsif Is_Limited_Type (Exp_Typ)
1374 (Is_Class_Wide_Type (Exp_Typ)
1375 or else Is_Interface (Exp_Typ)
1376 or else not Has_Unknown_Discriminants (Exp_Typ)
1377 or else not Is_Composite_Type (Unc_Type))
1381 -- For limited objects initialized with build in place function calls,
1382 -- nothing to be done; otherwise we prematurely introduce an N_Reference
1383 -- node in the expression initializing the object, which breaks the
1384 -- circuitry that detects and adds the additional arguments to the
1387 elsif Is_Build_In_Place_Function_Call (Exp) then
1391 Remove_Side_Effects (Exp);
1392 Rewrite (Subtype_Indic,
1393 Make_Subtype_From_Expr (Exp, Unc_Type));
1395 end Expand_Subtype_From_Expr;
1397 --------------------
1398 -- Find_Init_Call --
1399 --------------------
1401 function Find_Init_Call
1403 Rep_Clause : Node_Id) return Node_Id
1405 Typ : constant Entity_Id := Etype (Var);
1407 Init_Proc : Entity_Id;
1408 -- Initialization procedure for Typ
1410 function Find_Init_Call_In_List (From : Node_Id) return Node_Id;
1411 -- Look for init call for Var starting at From and scanning the
1412 -- enclosing list until Rep_Clause or the end of the list is reached.
1414 ----------------------------
1415 -- Find_Init_Call_In_List --
1416 ----------------------------
1418 function Find_Init_Call_In_List (From : Node_Id) return Node_Id is
1419 Init_Call : Node_Id;
1423 while Present (Init_Call) and then Init_Call /= Rep_Clause loop
1424 if Nkind (Init_Call) = N_Procedure_Call_Statement
1425 and then Is_Entity_Name (Name (Init_Call))
1426 and then Entity (Name (Init_Call)) = Init_Proc
1434 end Find_Init_Call_In_List;
1436 Init_Call : Node_Id;
1438 -- Start of processing for Find_Init_Call
1441 if not Has_Non_Null_Base_Init_Proc (Typ) then
1442 -- No init proc for the type, so obviously no call to be found
1447 Init_Proc := Base_Init_Proc (Typ);
1449 -- First scan the list containing the declaration of Var
1451 Init_Call := Find_Init_Call_In_List (From => Next (Parent (Var)));
1453 -- If not found, also look on Var's freeze actions list, if any, since
1454 -- the init call may have been moved there (case of an address clause
1455 -- applying to Var).
1457 if No (Init_Call) and then Present (Freeze_Node (Var)) then
1458 Init_Call := Find_Init_Call_In_List
1459 (First (Actions (Freeze_Node (Var))));
1465 ------------------------
1466 -- Find_Interface_ADT --
1467 ------------------------
1469 function Find_Interface_ADT
1471 Iface : Entity_Id) return Elmt_Id
1474 Typ : Entity_Id := T;
1477 pragma Assert (Is_Interface (Iface));
1479 -- Handle private types
1481 if Has_Private_Declaration (Typ)
1482 and then Present (Full_View (Typ))
1484 Typ := Full_View (Typ);
1487 -- Handle access types
1489 if Is_Access_Type (Typ) then
1490 Typ := Designated_Type (Typ);
1493 -- Handle task and protected types implementing interfaces
1495 if Is_Concurrent_Type (Typ) then
1496 Typ := Corresponding_Record_Type (Typ);
1500 (not Is_Class_Wide_Type (Typ)
1501 and then Ekind (Typ) /= E_Incomplete_Type);
1503 if Is_Ancestor (Iface, Typ) then
1504 return First_Elmt (Access_Disp_Table (Typ));
1508 Next_Elmt (Next_Elmt (First_Elmt (Access_Disp_Table (Typ))));
1510 and then Present (Related_Type (Node (ADT)))
1511 and then Related_Type (Node (ADT)) /= Iface
1512 and then not Is_Ancestor (Iface, Related_Type (Node (ADT)))
1517 pragma Assert (Present (Related_Type (Node (ADT))));
1520 end Find_Interface_ADT;
1522 ------------------------
1523 -- Find_Interface_Tag --
1524 ------------------------
1526 function Find_Interface_Tag
1528 Iface : Entity_Id) return Entity_Id
1531 Found : Boolean := False;
1532 Typ : Entity_Id := T;
1534 procedure Find_Tag (Typ : Entity_Id);
1535 -- Internal subprogram used to recursively climb to the ancestors
1541 procedure Find_Tag (Typ : Entity_Id) is
1546 -- This routine does not handle the case in which the interface is an
1547 -- ancestor of Typ. That case is handled by the enclosing subprogram.
1549 pragma Assert (Typ /= Iface);
1551 -- Climb to the root type handling private types
1553 if Present (Full_View (Etype (Typ))) then
1554 if Full_View (Etype (Typ)) /= Typ then
1555 Find_Tag (Full_View (Etype (Typ)));
1558 elsif Etype (Typ) /= Typ then
1559 Find_Tag (Etype (Typ));
1562 -- Traverse the list of interfaces implemented by the type
1565 and then Present (Interfaces (Typ))
1566 and then not (Is_Empty_Elmt_List (Interfaces (Typ)))
1568 -- Skip the tag associated with the primary table
1570 pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1571 AI_Tag := Next_Tag_Component (First_Tag_Component (Typ));
1572 pragma Assert (Present (AI_Tag));
1574 AI_Elmt := First_Elmt (Interfaces (Typ));
1575 while Present (AI_Elmt) loop
1576 AI := Node (AI_Elmt);
1578 if AI = Iface or else Is_Ancestor (Iface, AI) then
1583 AI_Tag := Next_Tag_Component (AI_Tag);
1584 Next_Elmt (AI_Elmt);
1589 -- Start of processing for Find_Interface_Tag
1592 pragma Assert (Is_Interface (Iface));
1594 -- Handle access types
1596 if Is_Access_Type (Typ) then
1597 Typ := Designated_Type (Typ);
1600 -- Handle class-wide types
1602 if Is_Class_Wide_Type (Typ) then
1603 Typ := Root_Type (Typ);
1606 -- Handle private types
1608 if Has_Private_Declaration (Typ)
1609 and then Present (Full_View (Typ))
1611 Typ := Full_View (Typ);
1614 -- Handle entities from the limited view
1616 if Ekind (Typ) = E_Incomplete_Type then
1617 pragma Assert (Present (Non_Limited_View (Typ)));
1618 Typ := Non_Limited_View (Typ);
1621 -- Handle task and protected types implementing interfaces
1623 if Is_Concurrent_Type (Typ) then
1624 Typ := Corresponding_Record_Type (Typ);
1627 -- If the interface is an ancestor of the type, then it shared the
1628 -- primary dispatch table.
1630 if Is_Ancestor (Iface, Typ) then
1631 pragma Assert (Etype (First_Tag_Component (Typ)) = RTE (RE_Tag));
1632 return First_Tag_Component (Typ);
1634 -- Otherwise we need to search for its associated tag component
1638 pragma Assert (Found);
1641 end Find_Interface_Tag;
1647 function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is
1649 Typ : Entity_Id := T;
1653 if Is_Class_Wide_Type (Typ) then
1654 Typ := Root_Type (Typ);
1657 Typ := Underlying_Type (Typ);
1659 -- Loop through primitive operations
1661 Prim := First_Elmt (Primitive_Operations (Typ));
1662 while Present (Prim) loop
1665 -- We can retrieve primitive operations by name if it is an internal
1666 -- name. For equality we must check that both of its operands have
1667 -- the same type, to avoid confusion with user-defined equalities
1668 -- than may have a non-symmetric signature.
1670 exit when Chars (Op) = Name
1673 or else Etype (First_Formal (Op)) = Etype (Last_Formal (Op)));
1677 -- Raise Program_Error if no primitive found
1680 raise Program_Error;
1691 function Find_Prim_Op
1693 Name : TSS_Name_Type) return Entity_Id
1696 Typ : Entity_Id := T;
1699 if Is_Class_Wide_Type (Typ) then
1700 Typ := Root_Type (Typ);
1703 Typ := Underlying_Type (Typ);
1705 Prim := First_Elmt (Primitive_Operations (Typ));
1706 while not Is_TSS (Node (Prim), Name) loop
1709 -- Raise program error if no primitive found
1712 raise Program_Error;
1719 ----------------------------
1720 -- Find_Protection_Object --
1721 ----------------------------
1723 function Find_Protection_Object (Scop : Entity_Id) return Entity_Id is
1728 while Present (S) loop
1729 if (Ekind (S) = E_Entry
1730 or else Ekind (S) = E_Entry_Family
1731 or else Ekind (S) = E_Function
1732 or else Ekind (S) = E_Procedure)
1733 and then Present (Protection_Object (S))
1735 return Protection_Object (S);
1741 -- If we do not find a Protection object in the scope chain, then
1742 -- something has gone wrong, most likely the object was never created.
1744 raise Program_Error;
1745 end Find_Protection_Object;
1747 ----------------------
1748 -- Force_Evaluation --
1749 ----------------------
1751 procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is
1753 Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True);
1754 end Force_Evaluation;
1756 ------------------------
1757 -- Generate_Poll_Call --
1758 ------------------------
1760 procedure Generate_Poll_Call (N : Node_Id) is
1762 -- No poll call if polling not active
1764 if not Polling_Required then
1767 -- Otherwise generate require poll call
1770 Insert_Before_And_Analyze (N,
1771 Make_Procedure_Call_Statement (Sloc (N),
1772 Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N))));
1774 end Generate_Poll_Call;
1776 ---------------------------------
1777 -- Get_Current_Value_Condition --
1778 ---------------------------------
1780 -- Note: the implementation of this procedure is very closely tied to the
1781 -- implementation of Set_Current_Value_Condition. In the Get procedure, we
1782 -- interpret Current_Value fields set by the Set procedure, so the two
1783 -- procedures need to be closely coordinated.
1785 procedure Get_Current_Value_Condition
1790 Loc : constant Source_Ptr := Sloc (Var);
1791 Ent : constant Entity_Id := Entity (Var);
1793 procedure Process_Current_Value_Condition
1796 -- N is an expression which holds either True (S = True) or False (S =
1797 -- False) in the condition. This procedure digs out the expression and
1798 -- if it refers to Ent, sets Op and Val appropriately.
1800 -------------------------------------
1801 -- Process_Current_Value_Condition --
1802 -------------------------------------
1804 procedure Process_Current_Value_Condition
1815 -- Deal with NOT operators, inverting sense
1817 while Nkind (Cond) = N_Op_Not loop
1818 Cond := Right_Opnd (Cond);
1822 -- Deal with AND THEN and AND cases
1824 if Nkind (Cond) = N_And_Then
1825 or else Nkind (Cond) = N_Op_And
1827 -- Don't ever try to invert a condition that is of the form of an
1828 -- AND or AND THEN (since we are not doing sufficiently general
1829 -- processing to allow this).
1831 if Sens = False then
1837 -- Recursively process AND and AND THEN branches
1839 Process_Current_Value_Condition (Left_Opnd (Cond), True);
1841 if Op /= N_Empty then
1845 Process_Current_Value_Condition (Right_Opnd (Cond), True);
1848 -- Case of relational operator
1850 elsif Nkind (Cond) in N_Op_Compare then
1853 -- Invert sense of test if inverted test
1855 if Sens = False then
1857 when N_Op_Eq => Op := N_Op_Ne;
1858 when N_Op_Ne => Op := N_Op_Eq;
1859 when N_Op_Lt => Op := N_Op_Ge;
1860 when N_Op_Gt => Op := N_Op_Le;
1861 when N_Op_Le => Op := N_Op_Gt;
1862 when N_Op_Ge => Op := N_Op_Lt;
1863 when others => raise Program_Error;
1867 -- Case of entity op value
1869 if Is_Entity_Name (Left_Opnd (Cond))
1870 and then Ent = Entity (Left_Opnd (Cond))
1871 and then Compile_Time_Known_Value (Right_Opnd (Cond))
1873 Val := Right_Opnd (Cond);
1875 -- Case of value op entity
1877 elsif Is_Entity_Name (Right_Opnd (Cond))
1878 and then Ent = Entity (Right_Opnd (Cond))
1879 and then Compile_Time_Known_Value (Left_Opnd (Cond))
1881 Val := Left_Opnd (Cond);
1883 -- We are effectively swapping operands
1886 when N_Op_Eq => null;
1887 when N_Op_Ne => null;
1888 when N_Op_Lt => Op := N_Op_Gt;
1889 when N_Op_Gt => Op := N_Op_Lt;
1890 when N_Op_Le => Op := N_Op_Ge;
1891 when N_Op_Ge => Op := N_Op_Le;
1892 when others => raise Program_Error;
1901 -- Case of Boolean variable reference, return as though the
1902 -- reference had said var = True.
1905 if Is_Entity_Name (Cond)
1906 and then Ent = Entity (Cond)
1908 Val := New_Occurrence_Of (Standard_True, Sloc (Cond));
1910 if Sens = False then
1917 end Process_Current_Value_Condition;
1919 -- Start of processing for Get_Current_Value_Condition
1925 -- Immediate return, nothing doing, if this is not an object
1927 if Ekind (Ent) not in Object_Kind then
1931 -- Otherwise examine current value
1934 CV : constant Node_Id := Current_Value (Ent);
1939 -- If statement. Condition is known true in THEN section, known False
1940 -- in any ELSIF or ELSE part, and unknown outside the IF statement.
1942 if Nkind (CV) = N_If_Statement then
1944 -- Before start of IF statement
1946 if Loc < Sloc (CV) then
1949 -- After end of IF statement
1951 elsif Loc >= Sloc (CV) + Text_Ptr (UI_To_Int (End_Span (CV))) then
1955 -- At this stage we know that we are within the IF statement, but
1956 -- unfortunately, the tree does not record the SLOC of the ELSE so
1957 -- we cannot use a simple SLOC comparison to distinguish between
1958 -- the then/else statements, so we have to climb the tree.
1965 while Parent (N) /= CV loop
1968 -- If we fall off the top of the tree, then that's odd, but
1969 -- perhaps it could occur in some error situation, and the
1970 -- safest response is simply to assume that the outcome of
1971 -- the condition is unknown. No point in bombing during an
1972 -- attempt to optimize things.
1979 -- Now we have N pointing to a node whose parent is the IF
1980 -- statement in question, so now we can tell if we are within
1981 -- the THEN statements.
1983 if Is_List_Member (N)
1984 and then List_Containing (N) = Then_Statements (CV)
1988 -- If the variable reference does not come from source, we
1989 -- cannot reliably tell whether it appears in the else part.
1990 -- In particular, if it appears in generated code for a node
1991 -- that requires finalization, it may be attached to a list
1992 -- that has not been yet inserted into the code. For now,
1993 -- treat it as unknown.
1995 elsif not Comes_From_Source (N) then
1998 -- Otherwise we must be in ELSIF or ELSE part
2005 -- ELSIF part. Condition is known true within the referenced
2006 -- ELSIF, known False in any subsequent ELSIF or ELSE part,
2007 -- and unknown before the ELSE part or after the IF statement.
2009 elsif Nkind (CV) = N_Elsif_Part then
2011 -- if the Elsif_Part had condition_actions, the elsif has been
2012 -- rewritten as a nested if, and the original elsif_part is
2013 -- detached from the tree, so there is no way to obtain useful
2014 -- information on the current value of the variable.
2015 -- Can this be improved ???
2017 if No (Parent (CV)) then
2023 -- Before start of ELSIF part
2025 if Loc < Sloc (CV) then
2028 -- After end of IF statement
2030 elsif Loc >= Sloc (Stm) +
2031 Text_Ptr (UI_To_Int (End_Span (Stm)))
2036 -- Again we lack the SLOC of the ELSE, so we need to climb the
2037 -- tree to see if we are within the ELSIF part in question.
2044 while Parent (N) /= Stm loop
2047 -- If we fall off the top of the tree, then that's odd, but
2048 -- perhaps it could occur in some error situation, and the
2049 -- safest response is simply to assume that the outcome of
2050 -- the condition is unknown. No point in bombing during an
2051 -- attempt to optimize things.
2058 -- Now we have N pointing to a node whose parent is the IF
2059 -- statement in question, so see if is the ELSIF part we want.
2060 -- the THEN statements.
2065 -- Otherwise we must be in subsequent ELSIF or ELSE part
2072 -- Iteration scheme of while loop. The condition is known to be
2073 -- true within the body of the loop.
2075 elsif Nkind (CV) = N_Iteration_Scheme then
2077 Loop_Stmt : constant Node_Id := Parent (CV);
2080 -- Before start of body of loop
2082 if Loc < Sloc (Loop_Stmt) then
2085 -- After end of LOOP statement
2087 elsif Loc >= Sloc (End_Label (Loop_Stmt)) then
2090 -- We are within the body of the loop
2097 -- All other cases of Current_Value settings
2103 -- If we fall through here, then we have a reportable condition, Sens
2104 -- is True if the condition is true and False if it needs inverting.
2106 Process_Current_Value_Condition (Condition (CV), Sens);
2108 end Get_Current_Value_Condition;
2110 ---------------------------------
2111 -- Has_Controlled_Coextensions --
2112 ---------------------------------
2114 function Has_Controlled_Coextensions (Typ : Entity_Id) return Boolean is
2119 -- Only consider record types
2121 if not Ekind_In (Typ, E_Record_Type, E_Record_Subtype) then
2125 if Has_Discriminants (Typ) then
2126 Discr := First_Discriminant (Typ);
2127 while Present (Discr) loop
2128 D_Typ := Etype (Discr);
2130 if Ekind (D_Typ) = E_Anonymous_Access_Type
2132 (Is_Controlled (Designated_Type (D_Typ))
2134 Is_Concurrent_Type (Designated_Type (D_Typ)))
2139 Next_Discriminant (Discr);
2144 end Has_Controlled_Coextensions;
2146 ------------------------
2147 -- Has_Address_Clause --
2148 ------------------------
2150 -- Should this function check the private part in a package ???
2152 function Has_Following_Address_Clause (D : Node_Id) return Boolean is
2153 Id : constant Entity_Id := Defining_Identifier (D);
2158 while Present (Decl) loop
2159 if Nkind (Decl) = N_At_Clause
2160 and then Chars (Identifier (Decl)) = Chars (Id)
2164 elsif Nkind (Decl) = N_Attribute_Definition_Clause
2165 and then Chars (Decl) = Name_Address
2166 and then Chars (Name (Decl)) = Chars (Id)
2175 end Has_Following_Address_Clause;
2177 --------------------
2178 -- Homonym_Number --
2179 --------------------
2181 function Homonym_Number (Subp : Entity_Id) return Nat is
2187 Hom := Homonym (Subp);
2188 while Present (Hom) loop
2189 if Scope (Hom) = Scope (Subp) then
2193 Hom := Homonym (Hom);
2199 ------------------------------
2200 -- In_Unconditional_Context --
2201 ------------------------------
2203 function In_Unconditional_Context (Node : Node_Id) return Boolean is
2208 while Present (P) loop
2210 when N_Subprogram_Body =>
2213 when N_If_Statement =>
2216 when N_Loop_Statement =>
2219 when N_Case_Statement =>
2228 end In_Unconditional_Context;
2234 procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is
2236 if Present (Ins_Action) then
2237 Insert_Actions (Assoc_Node, New_List (Ins_Action));
2241 -- Version with check(s) suppressed
2243 procedure Insert_Action
2244 (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id)
2247 Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress);
2250 --------------------
2251 -- Insert_Actions --
2252 --------------------
2254 procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is
2258 Wrapped_Node : Node_Id := Empty;
2261 if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
2265 -- Ignore insert of actions from inside default expression (or other
2266 -- similar "spec expression") in the special spec-expression analyze
2267 -- mode. Any insertions at this point have no relevance, since we are
2268 -- only doing the analyze to freeze the types of any static expressions.
2269 -- See section "Handling of Default Expressions" in the spec of package
2270 -- Sem for further details.
2272 if In_Spec_Expression then
2276 -- If the action derives from stuff inside a record, then the actions
2277 -- are attached to the current scope, to be inserted and analyzed on
2278 -- exit from the scope. The reason for this is that we may also
2279 -- be generating freeze actions at the same time, and they must
2280 -- eventually be elaborated in the correct order.
2282 if Is_Record_Type (Current_Scope)
2283 and then not Is_Frozen (Current_Scope)
2285 if No (Scope_Stack.Table
2286 (Scope_Stack.Last).Pending_Freeze_Actions)
2288 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
2293 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
2299 -- We now intend to climb up the tree to find the right point to
2300 -- insert the actions. We start at Assoc_Node, unless this node is
2301 -- a subexpression in which case we start with its parent. We do this
2302 -- for two reasons. First it speeds things up. Second, if Assoc_Node
2303 -- is itself one of the special nodes like N_And_Then, then we assume
2304 -- that an initial request to insert actions for such a node does not
2305 -- expect the actions to get deposited in the node for later handling
2306 -- when the node is expanded, since clearly the node is being dealt
2307 -- with by the caller. Note that in the subexpression case, N is
2308 -- always the child we came from.
2310 -- N_Raise_xxx_Error is an annoying special case, it is a statement
2311 -- if it has type Standard_Void_Type, and a subexpression otherwise.
2312 -- otherwise. Procedure attribute references are also statements.
2314 if Nkind (Assoc_Node) in N_Subexpr
2315 and then (Nkind (Assoc_Node) in N_Raise_xxx_Error
2316 or else Etype (Assoc_Node) /= Standard_Void_Type)
2317 and then (Nkind (Assoc_Node) /= N_Attribute_Reference
2319 not Is_Procedure_Attribute_Name
2320 (Attribute_Name (Assoc_Node)))
2322 P := Assoc_Node; -- ??? does not agree with above!
2323 N := Parent (Assoc_Node);
2325 -- Non-subexpression case. Note that N is initially Empty in this
2326 -- case (N is only guaranteed Non-Empty in the subexpr case).
2333 -- Capture root of the transient scope
2335 if Scope_Is_Transient then
2336 Wrapped_Node := Node_To_Be_Wrapped;
2340 pragma Assert (Present (P));
2344 -- Case of right operand of AND THEN or OR ELSE. Put the actions
2345 -- in the Actions field of the right operand. They will be moved
2346 -- out further when the AND THEN or OR ELSE operator is expanded.
2347 -- Nothing special needs to be done for the left operand since
2348 -- in that case the actions are executed unconditionally.
2350 when N_Short_Circuit =>
2351 if N = Right_Opnd (P) then
2353 -- We are now going to either append the actions to the
2354 -- actions field of the short-circuit operation. We will
2355 -- also analyze the actions now.
2357 -- This analysis is really too early, the proper thing would
2358 -- be to just park them there now, and only analyze them if
2359 -- we find we really need them, and to it at the proper
2360 -- final insertion point. However attempting to this proved
2361 -- tricky, so for now we just kill current values before and
2362 -- after the analyze call to make sure we avoid peculiar
2363 -- optimizations from this out of order insertion.
2365 Kill_Current_Values;
2367 if Present (Actions (P)) then
2368 Insert_List_After_And_Analyze
2369 (Last (Actions (P)), Ins_Actions);
2371 Set_Actions (P, Ins_Actions);
2372 Analyze_List (Actions (P));
2375 Kill_Current_Values;
2380 -- Then or Else operand of conditional expression. Add actions to
2381 -- Then_Actions or Else_Actions field as appropriate. The actions
2382 -- will be moved further out when the conditional is expanded.
2384 when N_Conditional_Expression =>
2386 ThenX : constant Node_Id := Next (First (Expressions (P)));
2387 ElseX : constant Node_Id := Next (ThenX);
2390 -- If the enclosing expression is already analyzed, as
2391 -- is the case for nested elaboration checks, insert the
2392 -- conditional further out.
2394 if Analyzed (P) then
2397 -- Actions belong to the then expression, temporarily place
2398 -- them as Then_Actions of the conditional expr. They will
2399 -- be moved to the proper place later when the conditional
2400 -- expression is expanded.
2402 elsif N = ThenX then
2403 if Present (Then_Actions (P)) then
2404 Insert_List_After_And_Analyze
2405 (Last (Then_Actions (P)), Ins_Actions);
2407 Set_Then_Actions (P, Ins_Actions);
2408 Analyze_List (Then_Actions (P));
2413 -- Actions belong to the else expression, temporarily
2414 -- place them as Else_Actions of the conditional expr.
2415 -- They will be moved to the proper place later when
2416 -- the conditional expression is expanded.
2418 elsif N = ElseX then
2419 if Present (Else_Actions (P)) then
2420 Insert_List_After_And_Analyze
2421 (Last (Else_Actions (P)), Ins_Actions);
2423 Set_Else_Actions (P, Ins_Actions);
2424 Analyze_List (Else_Actions (P));
2429 -- Actions belong to the condition. In this case they are
2430 -- unconditionally executed, and so we can continue the
2431 -- search for the proper insert point.
2438 -- Alternative of case expression, we place the action in the
2439 -- Actions field of the case expression alternative, this will
2440 -- be handled when the case expression is expanded.
2442 when N_Case_Expression_Alternative =>
2443 if Present (Actions (P)) then
2444 Insert_List_After_And_Analyze
2445 (Last (Actions (P)), Ins_Actions);
2447 Set_Actions (P, Ins_Actions);
2448 Analyze_List (Then_Actions (P));
2453 -- Case of appearing within an Expressions_With_Actions node. We
2454 -- prepend the actions to the list of actions already there.
2456 when N_Expression_With_Actions =>
2457 Prepend_List (Ins_Actions, Actions (P));
2460 -- Case of appearing in the condition of a while expression or
2461 -- elsif. We insert the actions into the Condition_Actions field.
2462 -- They will be moved further out when the while loop or elsif
2465 when N_Iteration_Scheme |
2468 if N = Condition (P) then
2469 if Present (Condition_Actions (P)) then
2470 Insert_List_After_And_Analyze
2471 (Last (Condition_Actions (P)), Ins_Actions);
2473 Set_Condition_Actions (P, Ins_Actions);
2475 -- Set the parent of the insert actions explicitly. This
2476 -- is not a syntactic field, but we need the parent field
2477 -- set, in particular so that freeze can understand that
2478 -- it is dealing with condition actions, and properly
2479 -- insert the freezing actions.
2481 Set_Parent (Ins_Actions, P);
2482 Analyze_List (Condition_Actions (P));
2488 -- Statements, declarations, pragmas, representation clauses
2493 N_Procedure_Call_Statement |
2494 N_Statement_Other_Than_Procedure_Call |
2500 -- Representation_Clause
2503 N_Attribute_Definition_Clause |
2504 N_Enumeration_Representation_Clause |
2505 N_Record_Representation_Clause |
2509 N_Abstract_Subprogram_Declaration |
2511 N_Exception_Declaration |
2512 N_Exception_Renaming_Declaration |
2513 N_Formal_Abstract_Subprogram_Declaration |
2514 N_Formal_Concrete_Subprogram_Declaration |
2515 N_Formal_Object_Declaration |
2516 N_Formal_Type_Declaration |
2517 N_Full_Type_Declaration |
2518 N_Function_Instantiation |
2519 N_Generic_Function_Renaming_Declaration |
2520 N_Generic_Package_Declaration |
2521 N_Generic_Package_Renaming_Declaration |
2522 N_Generic_Procedure_Renaming_Declaration |
2523 N_Generic_Subprogram_Declaration |
2524 N_Implicit_Label_Declaration |
2525 N_Incomplete_Type_Declaration |
2526 N_Number_Declaration |
2527 N_Object_Declaration |
2528 N_Object_Renaming_Declaration |
2530 N_Package_Body_Stub |
2531 N_Package_Declaration |
2532 N_Package_Instantiation |
2533 N_Package_Renaming_Declaration |
2534 N_Private_Extension_Declaration |
2535 N_Private_Type_Declaration |
2536 N_Procedure_Instantiation |
2538 N_Protected_Body_Stub |
2539 N_Protected_Type_Declaration |
2540 N_Single_Task_Declaration |
2542 N_Subprogram_Body_Stub |
2543 N_Subprogram_Declaration |
2544 N_Subprogram_Renaming_Declaration |
2545 N_Subtype_Declaration |
2548 N_Task_Type_Declaration |
2550 -- Freeze entity behaves like a declaration or statement
2554 -- Do not insert here if the item is not a list member (this
2555 -- happens for example with a triggering statement, and the
2556 -- proper approach is to insert before the entire select).
2558 if not Is_List_Member (P) then
2561 -- Do not insert if parent of P is an N_Component_Association
2562 -- node (i.e. we are in the context of an N_Aggregate or
2563 -- N_Extension_Aggregate node. In this case we want to insert
2564 -- before the entire aggregate.
2566 elsif Nkind (Parent (P)) = N_Component_Association then
2569 -- Do not insert if the parent of P is either an N_Variant
2570 -- node or an N_Record_Definition node, meaning in either
2571 -- case that P is a member of a component list, and that
2572 -- therefore the actions should be inserted outside the
2573 -- complete record declaration.
2575 elsif Nkind (Parent (P)) = N_Variant
2576 or else Nkind (Parent (P)) = N_Record_Definition
2580 -- Do not insert freeze nodes within the loop generated for
2581 -- an aggregate, because they may be elaborated too late for
2582 -- subsequent use in the back end: within a package spec the
2583 -- loop is part of the elaboration procedure and is only
2584 -- elaborated during the second pass.
2586 -- If the loop comes from source, or the entity is local to
2587 -- the loop itself it must remain within.
2589 elsif Nkind (Parent (P)) = N_Loop_Statement
2590 and then not Comes_From_Source (Parent (P))
2591 and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
2593 Scope (Entity (First (Ins_Actions))) /= Current_Scope
2597 -- Otherwise we can go ahead and do the insertion
2599 elsif P = Wrapped_Node then
2600 Store_Before_Actions_In_Scope (Ins_Actions);
2604 Insert_List_Before_And_Analyze (P, Ins_Actions);
2608 -- A special case, N_Raise_xxx_Error can act either as a statement
2609 -- or a subexpression. We tell the difference by looking at the
2610 -- Etype. It is set to Standard_Void_Type in the statement case.
2613 N_Raise_xxx_Error =>
2614 if Etype (P) = Standard_Void_Type then
2615 if P = Wrapped_Node then
2616 Store_Before_Actions_In_Scope (Ins_Actions);
2618 Insert_List_Before_And_Analyze (P, Ins_Actions);
2623 -- In the subexpression case, keep climbing
2629 -- If a component association appears within a loop created for
2630 -- an array aggregate, attach the actions to the association so
2631 -- they can be subsequently inserted within the loop. For other
2632 -- component associations insert outside of the aggregate. For
2633 -- an association that will generate a loop, its Loop_Actions
2634 -- attribute is already initialized (see exp_aggr.adb).
2636 -- The list of loop_actions can in turn generate additional ones,
2637 -- that are inserted before the associated node. If the associated
2638 -- node is outside the aggregate, the new actions are collected
2639 -- at the end of the loop actions, to respect the order in which
2640 -- they are to be elaborated.
2643 N_Component_Association =>
2644 if Nkind (Parent (P)) = N_Aggregate
2645 and then Present (Loop_Actions (P))
2647 if Is_Empty_List (Loop_Actions (P)) then
2648 Set_Loop_Actions (P, Ins_Actions);
2649 Analyze_List (Ins_Actions);
2656 -- Check whether these actions were generated by a
2657 -- declaration that is part of the loop_ actions
2658 -- for the component_association.
2661 while Present (Decl) loop
2662 exit when Parent (Decl) = P
2663 and then Is_List_Member (Decl)
2665 List_Containing (Decl) = Loop_Actions (P);
2666 Decl := Parent (Decl);
2669 if Present (Decl) then
2670 Insert_List_Before_And_Analyze
2671 (Decl, Ins_Actions);
2673 Insert_List_After_And_Analyze
2674 (Last (Loop_Actions (P)), Ins_Actions);
2685 -- Another special case, an attribute denoting a procedure call
2688 N_Attribute_Reference =>
2689 if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
2690 if P = Wrapped_Node then
2691 Store_Before_Actions_In_Scope (Ins_Actions);
2693 Insert_List_Before_And_Analyze (P, Ins_Actions);
2698 -- In the subexpression case, keep climbing
2704 -- For all other node types, keep climbing tree
2708 N_Accept_Alternative |
2709 N_Access_Definition |
2710 N_Access_Function_Definition |
2711 N_Access_Procedure_Definition |
2712 N_Access_To_Object_Definition |
2716 N_Case_Statement_Alternative |
2717 N_Character_Literal |
2718 N_Compilation_Unit |
2719 N_Compilation_Unit_Aux |
2720 N_Component_Clause |
2721 N_Component_Declaration |
2722 N_Component_Definition |
2724 N_Constrained_Array_Definition |
2725 N_Decimal_Fixed_Point_Definition |
2726 N_Defining_Character_Literal |
2727 N_Defining_Identifier |
2728 N_Defining_Operator_Symbol |
2729 N_Defining_Program_Unit_Name |
2730 N_Delay_Alternative |
2731 N_Delta_Constraint |
2732 N_Derived_Type_Definition |
2734 N_Digits_Constraint |
2735 N_Discriminant_Association |
2736 N_Discriminant_Specification |
2738 N_Entry_Body_Formal_Part |
2739 N_Entry_Call_Alternative |
2740 N_Entry_Declaration |
2741 N_Entry_Index_Specification |
2742 N_Enumeration_Type_Definition |
2744 N_Exception_Handler |
2746 N_Explicit_Dereference |
2747 N_Extension_Aggregate |
2748 N_Floating_Point_Definition |
2749 N_Formal_Decimal_Fixed_Point_Definition |
2750 N_Formal_Derived_Type_Definition |
2751 N_Formal_Discrete_Type_Definition |
2752 N_Formal_Floating_Point_Definition |
2753 N_Formal_Modular_Type_Definition |
2754 N_Formal_Ordinary_Fixed_Point_Definition |
2755 N_Formal_Package_Declaration |
2756 N_Formal_Private_Type_Definition |
2757 N_Formal_Signed_Integer_Type_Definition |
2759 N_Function_Specification |
2760 N_Generic_Association |
2761 N_Handled_Sequence_Of_Statements |
2764 N_Index_Or_Discriminant_Constraint |
2765 N_Indexed_Component |
2769 N_Loop_Parameter_Specification |
2771 N_Modular_Type_Definition |
2797 N_Op_Shift_Right_Arithmetic |
2801 N_Ordinary_Fixed_Point_Definition |
2803 N_Package_Specification |
2804 N_Parameter_Association |
2805 N_Parameter_Specification |
2806 N_Pop_Constraint_Error_Label |
2807 N_Pop_Program_Error_Label |
2808 N_Pop_Storage_Error_Label |
2809 N_Pragma_Argument_Association |
2810 N_Procedure_Specification |
2811 N_Protected_Definition |
2812 N_Push_Constraint_Error_Label |
2813 N_Push_Program_Error_Label |
2814 N_Push_Storage_Error_Label |
2815 N_Qualified_Expression |
2817 N_Range_Constraint |
2819 N_Real_Range_Specification |
2820 N_Record_Definition |
2822 N_SCIL_Dispatch_Table_Tag_Init |
2823 N_SCIL_Dispatching_Call |
2824 N_SCIL_Membership_Test |
2825 N_Selected_Component |
2826 N_Signed_Integer_Type_Definition |
2827 N_Single_Protected_Declaration |
2831 N_Subtype_Indication |
2834 N_Terminate_Alternative |
2835 N_Triggering_Alternative |
2837 N_Unchecked_Expression |
2838 N_Unchecked_Type_Conversion |
2839 N_Unconstrained_Array_Definition |
2842 N_Use_Package_Clause |
2846 N_Validate_Unchecked_Conversion |
2853 -- Make sure that inserted actions stay in the transient scope
2855 if P = Wrapped_Node then
2856 Store_Before_Actions_In_Scope (Ins_Actions);
2860 -- If we fall through above tests, keep climbing tree
2864 if Nkind (Parent (N)) = N_Subunit then
2866 -- This is the proper body corresponding to a stub. Insertion must
2867 -- be done at the point of the stub, which is in the declarative
2868 -- part of the parent unit.
2870 P := Corresponding_Stub (Parent (N));
2878 -- Version with check(s) suppressed
2880 procedure Insert_Actions
2881 (Assoc_Node : Node_Id;
2882 Ins_Actions : List_Id;
2883 Suppress : Check_Id)
2886 if Suppress = All_Checks then
2888 Svg : constant Suppress_Array := Scope_Suppress;
2890 Scope_Suppress := (others => True);
2891 Insert_Actions (Assoc_Node, Ins_Actions);
2892 Scope_Suppress := Svg;
2897 Svg : constant Boolean := Scope_Suppress (Suppress);
2899 Scope_Suppress (Suppress) := True;
2900 Insert_Actions (Assoc_Node, Ins_Actions);
2901 Scope_Suppress (Suppress) := Svg;
2906 --------------------------
2907 -- Insert_Actions_After --
2908 --------------------------
2910 procedure Insert_Actions_After
2911 (Assoc_Node : Node_Id;
2912 Ins_Actions : List_Id)
2915 if Scope_Is_Transient
2916 and then Assoc_Node = Node_To_Be_Wrapped
2918 Store_After_Actions_In_Scope (Ins_Actions);
2920 Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
2922 end Insert_Actions_After;
2924 ---------------------------------
2925 -- Insert_Library_Level_Action --
2926 ---------------------------------
2928 procedure Insert_Library_Level_Action (N : Node_Id) is
2929 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2932 Push_Scope (Cunit_Entity (Main_Unit));
2933 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2935 if No (Actions (Aux)) then
2936 Set_Actions (Aux, New_List (N));
2938 Append (N, Actions (Aux));
2943 end Insert_Library_Level_Action;
2945 ----------------------------------
2946 -- Insert_Library_Level_Actions --
2947 ----------------------------------
2949 procedure Insert_Library_Level_Actions (L : List_Id) is
2950 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
2953 if Is_Non_Empty_List (L) then
2954 Push_Scope (Cunit_Entity (Main_Unit));
2955 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2957 if No (Actions (Aux)) then
2958 Set_Actions (Aux, L);
2961 Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
2966 end Insert_Library_Level_Actions;
2968 ----------------------
2969 -- Inside_Init_Proc --
2970 ----------------------
2972 function Inside_Init_Proc return Boolean is
2978 and then S /= Standard_Standard
2980 if Is_Init_Proc (S) then
2988 end Inside_Init_Proc;
2990 ----------------------------
2991 -- Is_All_Null_Statements --
2992 ----------------------------
2994 function Is_All_Null_Statements (L : List_Id) return Boolean is
2999 while Present (Stm) loop
3000 if Nkind (Stm) /= N_Null_Statement then
3008 end Is_All_Null_Statements;
3010 ---------------------------------
3011 -- Is_Fully_Repped_Tagged_Type --
3012 ---------------------------------
3014 function Is_Fully_Repped_Tagged_Type (T : Entity_Id) return Boolean is
3015 U : constant Entity_Id := Underlying_Type (T);
3019 if No (U) or else not Is_Tagged_Type (U) then
3021 elsif Has_Discriminants (U) then
3023 elsif not Has_Specified_Layout (U) then
3027 -- Here we have a tagged type, see if it has any unlayed out fields
3028 -- other than a possible tag and parent fields. If so, we return False.
3030 Comp := First_Component (U);
3031 while Present (Comp) loop
3032 if not Is_Tag (Comp)
3033 and then Chars (Comp) /= Name_uParent
3034 and then No (Component_Clause (Comp))
3038 Next_Component (Comp);
3042 -- All components are layed out
3045 end Is_Fully_Repped_Tagged_Type;
3047 ----------------------------------
3048 -- Is_Library_Level_Tagged_Type --
3049 ----------------------------------
3051 function Is_Library_Level_Tagged_Type (Typ : Entity_Id) return Boolean is
3053 return Is_Tagged_Type (Typ)
3054 and then Is_Library_Level_Entity (Typ);
3055 end Is_Library_Level_Tagged_Type;
3057 ----------------------------------
3058 -- Is_Possibly_Unaligned_Object --
3059 ----------------------------------
3061 function Is_Possibly_Unaligned_Object (N : Node_Id) return Boolean is
3062 T : constant Entity_Id := Etype (N);
3065 -- If renamed object, apply test to underlying object
3067 if Is_Entity_Name (N)
3068 and then Is_Object (Entity (N))
3069 and then Present (Renamed_Object (Entity (N)))
3071 return Is_Possibly_Unaligned_Object (Renamed_Object (Entity (N)));
3074 -- Tagged and controlled types and aliased types are always aligned,
3075 -- as are concurrent types.
3078 or else Has_Controlled_Component (T)
3079 or else Is_Concurrent_Type (T)
3080 or else Is_Tagged_Type (T)
3081 or else Is_Controlled (T)
3086 -- If this is an element of a packed array, may be unaligned
3088 if Is_Ref_To_Bit_Packed_Array (N) then
3092 -- Case of component reference
3094 if Nkind (N) = N_Selected_Component then
3096 P : constant Node_Id := Prefix (N);
3097 C : constant Entity_Id := Entity (Selector_Name (N));
3102 -- If component reference is for an array with non-static bounds,
3103 -- then it is always aligned: we can only process unaligned
3104 -- arrays with static bounds (more accurately bounds known at
3107 if Is_Array_Type (T)
3108 and then not Compile_Time_Known_Bounds (T)
3113 -- If component is aliased, it is definitely properly aligned
3115 if Is_Aliased (C) then
3119 -- If component is for a type implemented as a scalar, and the
3120 -- record is packed, and the component is other than the first
3121 -- component of the record, then the component may be unaligned.
3123 if Is_Packed (Etype (P))
3124 and then Represented_As_Scalar (Etype (C))
3125 and then First_Entity (Scope (C)) /= C
3130 -- Compute maximum possible alignment for T
3132 -- If alignment is known, then that settles things
3134 if Known_Alignment (T) then
3135 M := UI_To_Int (Alignment (T));
3137 -- If alignment is not known, tentatively set max alignment
3140 M := Ttypes.Maximum_Alignment;
3142 -- We can reduce this if the Esize is known since the default
3143 -- alignment will never be more than the smallest power of 2
3144 -- that does not exceed this Esize value.
3146 if Known_Esize (T) then
3147 S := UI_To_Int (Esize (T));
3149 while (M / 2) >= S loop
3155 -- The following code is historical, it used to be present but it
3156 -- is too cautious, because the front-end does not know the proper
3157 -- default alignments for the target. Also, if the alignment is
3158 -- not known, the front end can't know in any case! If a copy is
3159 -- needed, the back-end will take care of it. This whole section
3160 -- including this comment can be removed later ???
3162 -- If the component reference is for a record that has a specified
3163 -- alignment, and we either know it is too small, or cannot tell,
3164 -- then the component may be unaligned.
3166 -- if Known_Alignment (Etype (P))
3167 -- and then Alignment (Etype (P)) < Ttypes.Maximum_Alignment
3168 -- and then M > Alignment (Etype (P))
3173 -- Case of component clause present which may specify an
3174 -- unaligned position.
3176 if Present (Component_Clause (C)) then
3178 -- Otherwise we can do a test to make sure that the actual
3179 -- start position in the record, and the length, are both
3180 -- consistent with the required alignment. If not, we know
3181 -- that we are unaligned.
3184 Align_In_Bits : constant Nat := M * System_Storage_Unit;
3186 if Component_Bit_Offset (C) mod Align_In_Bits /= 0
3187 or else Esize (C) mod Align_In_Bits /= 0
3194 -- Otherwise, for a component reference, test prefix
3196 return Is_Possibly_Unaligned_Object (P);
3199 -- If not a component reference, must be aligned
3204 end Is_Possibly_Unaligned_Object;
3206 ---------------------------------
3207 -- Is_Possibly_Unaligned_Slice --
3208 ---------------------------------
3210 function Is_Possibly_Unaligned_Slice (N : Node_Id) return Boolean is
3212 -- Go to renamed object
3214 if Is_Entity_Name (N)
3215 and then Is_Object (Entity (N))
3216 and then Present (Renamed_Object (Entity (N)))
3218 return Is_Possibly_Unaligned_Slice (Renamed_Object (Entity (N)));
3221 -- The reference must be a slice
3223 if Nkind (N) /= N_Slice then
3227 -- Always assume the worst for a nested record component with a
3228 -- component clause, which gigi/gcc does not appear to handle well.
3229 -- It is not clear why this special test is needed at all ???
3231 if Nkind (Prefix (N)) = N_Selected_Component
3232 and then Nkind (Prefix (Prefix (N))) = N_Selected_Component
3234 Present (Component_Clause (Entity (Selector_Name (Prefix (N)))))
3239 -- We only need to worry if the target has strict alignment
3241 if not Target_Strict_Alignment then
3245 -- If it is a slice, then look at the array type being sliced
3248 Sarr : constant Node_Id := Prefix (N);
3249 -- Prefix of the slice, i.e. the array being sliced
3251 Styp : constant Entity_Id := Etype (Prefix (N));
3252 -- Type of the array being sliced
3258 -- The problems arise if the array object that is being sliced
3259 -- is a component of a record or array, and we cannot guarantee
3260 -- the alignment of the array within its containing object.
3262 -- To investigate this, we look at successive prefixes to see
3263 -- if we have a worrisome indexed or selected component.
3267 -- Case of array is part of an indexed component reference
3269 if Nkind (Pref) = N_Indexed_Component then
3270 Ptyp := Etype (Prefix (Pref));
3272 -- The only problematic case is when the array is packed,
3273 -- in which case we really know nothing about the alignment
3274 -- of individual components.
3276 if Is_Bit_Packed_Array (Ptyp) then
3280 -- Case of array is part of a selected component reference
3282 elsif Nkind (Pref) = N_Selected_Component then
3283 Ptyp := Etype (Prefix (Pref));
3285 -- We are definitely in trouble if the record in question
3286 -- has an alignment, and either we know this alignment is
3287 -- inconsistent with the alignment of the slice, or we
3288 -- don't know what the alignment of the slice should be.
3290 if Known_Alignment (Ptyp)
3291 and then (Unknown_Alignment (Styp)
3292 or else Alignment (Styp) > Alignment (Ptyp))
3297 -- We are in potential trouble if the record type is packed.
3298 -- We could special case when we know that the array is the
3299 -- first component, but that's not such a simple case ???
3301 if Is_Packed (Ptyp) then
3305 -- We are in trouble if there is a component clause, and
3306 -- either we do not know the alignment of the slice, or
3307 -- the alignment of the slice is inconsistent with the
3308 -- bit position specified by the component clause.
3311 Field : constant Entity_Id := Entity (Selector_Name (Pref));
3313 if Present (Component_Clause (Field))
3315 (Unknown_Alignment (Styp)
3317 (Component_Bit_Offset (Field) mod
3318 (System_Storage_Unit * Alignment (Styp))) /= 0)
3324 -- For cases other than selected or indexed components we
3325 -- know we are OK, since no issues arise over alignment.
3331 -- We processed an indexed component or selected component
3332 -- reference that looked safe, so keep checking prefixes.
3334 Pref := Prefix (Pref);
3337 end Is_Possibly_Unaligned_Slice;
3339 --------------------------------
3340 -- Is_Ref_To_Bit_Packed_Array --
3341 --------------------------------
3343 function Is_Ref_To_Bit_Packed_Array (N : Node_Id) return Boolean is
3348 if Is_Entity_Name (N)
3349 and then Is_Object (Entity (N))
3350 and then Present (Renamed_Object (Entity (N)))
3352 return Is_Ref_To_Bit_Packed_Array (Renamed_Object (Entity (N)));
3355 if Nkind (N) = N_Indexed_Component
3357 Nkind (N) = N_Selected_Component
3359 if Is_Bit_Packed_Array (Etype (Prefix (N))) then
3362 Result := Is_Ref_To_Bit_Packed_Array (Prefix (N));
3365 if Result and then Nkind (N) = N_Indexed_Component then
3366 Expr := First (Expressions (N));
3367 while Present (Expr) loop
3368 Force_Evaluation (Expr);
3378 end Is_Ref_To_Bit_Packed_Array;
3380 --------------------------------
3381 -- Is_Ref_To_Bit_Packed_Slice --
3382 --------------------------------
3384 function Is_Ref_To_Bit_Packed_Slice (N : Node_Id) return Boolean is
3386 if Nkind (N) = N_Type_Conversion then
3387 return Is_Ref_To_Bit_Packed_Slice (Expression (N));
3389 elsif Is_Entity_Name (N)
3390 and then Is_Object (Entity (N))
3391 and then Present (Renamed_Object (Entity (N)))
3393 return Is_Ref_To_Bit_Packed_Slice (Renamed_Object (Entity (N)));
3395 elsif Nkind (N) = N_Slice
3396 and then Is_Bit_Packed_Array (Etype (Prefix (N)))
3400 elsif Nkind (N) = N_Indexed_Component
3402 Nkind (N) = N_Selected_Component
3404 return Is_Ref_To_Bit_Packed_Slice (Prefix (N));
3409 end Is_Ref_To_Bit_Packed_Slice;
3411 -----------------------
3412 -- Is_Renamed_Object --
3413 -----------------------
3415 function Is_Renamed_Object (N : Node_Id) return Boolean is
3416 Pnod : constant Node_Id := Parent (N);
3417 Kind : constant Node_Kind := Nkind (Pnod);
3419 if Kind = N_Object_Renaming_Declaration then
3421 elsif Nkind_In (Kind, N_Indexed_Component, N_Selected_Component) then
3422 return Is_Renamed_Object (Pnod);
3426 end Is_Renamed_Object;
3428 ----------------------------
3429 -- Is_Untagged_Derivation --
3430 ----------------------------
3432 function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
3434 return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
3436 (Is_Private_Type (T) and then Present (Full_View (T))
3437 and then not Is_Tagged_Type (Full_View (T))
3438 and then Is_Derived_Type (Full_View (T))
3439 and then Etype (Full_View (T)) /= T);
3440 end Is_Untagged_Derivation;
3442 ---------------------------
3443 -- Is_Volatile_Reference --
3444 ---------------------------
3446 function Is_Volatile_Reference (N : Node_Id) return Boolean is
3448 if Nkind (N) in N_Has_Etype
3449 and then Present (Etype (N))
3450 and then Treat_As_Volatile (Etype (N))
3454 elsif Is_Entity_Name (N) then
3455 return Treat_As_Volatile (Entity (N));
3457 elsif Nkind (N) = N_Slice then
3458 return Is_Volatile_Reference (Prefix (N));
3460 elsif Nkind_In (N, N_Indexed_Component, N_Selected_Component) then
3461 if (Is_Entity_Name (Prefix (N))
3462 and then Has_Volatile_Components (Entity (Prefix (N))))
3463 or else (Present (Etype (Prefix (N)))
3464 and then Has_Volatile_Components (Etype (Prefix (N))))
3468 return Is_Volatile_Reference (Prefix (N));
3474 end Is_Volatile_Reference;
3476 --------------------
3477 -- Kill_Dead_Code --
3478 --------------------
3480 procedure Kill_Dead_Code (N : Node_Id; Warn : Boolean := False) is
3481 W : Boolean := Warn;
3482 -- Set False if warnings suppressed
3486 Remove_Warning_Messages (N);
3488 -- Generate warning if appropriate
3492 -- We suppress the warning if this code is under control of an
3493 -- if statement, whose condition is a simple identifier, and
3494 -- either we are in an instance, or warnings off is set for this
3495 -- identifier. The reason for killing it in the instance case is
3496 -- that it is common and reasonable for code to be deleted in
3497 -- instances for various reasons.
3499 if Nkind (Parent (N)) = N_If_Statement then
3501 C : constant Node_Id := Condition (Parent (N));
3503 if Nkind (C) = N_Identifier
3506 or else (Present (Entity (C))
3507 and then Has_Warnings_Off (Entity (C))))
3514 -- Generate warning if not suppressed
3518 ("?this code can never be executed and has been deleted!", N);
3522 -- Recurse into block statements and bodies to process declarations
3525 if Nkind (N) = N_Block_Statement
3526 or else Nkind (N) = N_Subprogram_Body
3527 or else Nkind (N) = N_Package_Body
3529 Kill_Dead_Code (Declarations (N), False);
3530 Kill_Dead_Code (Statements (Handled_Statement_Sequence (N)));
3532 if Nkind (N) = N_Subprogram_Body then
3533 Set_Is_Eliminated (Defining_Entity (N));
3536 elsif Nkind (N) = N_Package_Declaration then
3537 Kill_Dead_Code (Visible_Declarations (Specification (N)));
3538 Kill_Dead_Code (Private_Declarations (Specification (N)));
3540 -- ??? After this point, Delete_Tree has been called on all
3541 -- declarations in Specification (N), so references to
3542 -- entities therein look suspicious.
3545 E : Entity_Id := First_Entity (Defining_Entity (N));
3547 while Present (E) loop
3548 if Ekind (E) = E_Operator then
3549 Set_Is_Eliminated (E);
3556 -- Recurse into composite statement to kill individual statements,
3557 -- in particular instantiations.
3559 elsif Nkind (N) = N_If_Statement then
3560 Kill_Dead_Code (Then_Statements (N));
3561 Kill_Dead_Code (Elsif_Parts (N));
3562 Kill_Dead_Code (Else_Statements (N));
3564 elsif Nkind (N) = N_Loop_Statement then
3565 Kill_Dead_Code (Statements (N));
3567 elsif Nkind (N) = N_Case_Statement then
3571 Alt := First (Alternatives (N));
3572 while Present (Alt) loop
3573 Kill_Dead_Code (Statements (Alt));
3578 elsif Nkind (N) = N_Case_Statement_Alternative then
3579 Kill_Dead_Code (Statements (N));
3581 -- Deal with dead instances caused by deleting instantiations
3583 elsif Nkind (N) in N_Generic_Instantiation then
3584 Remove_Dead_Instance (N);
3589 -- Case where argument is a list of nodes to be killed
3591 procedure Kill_Dead_Code (L : List_Id; Warn : Boolean := False) is
3596 if Is_Non_Empty_List (L) then
3598 while Present (N) loop
3599 Kill_Dead_Code (N, W);
3606 ------------------------
3607 -- Known_Non_Negative --
3608 ------------------------
3610 function Known_Non_Negative (Opnd : Node_Id) return Boolean is
3612 if Is_OK_Static_Expression (Opnd)
3613 and then Expr_Value (Opnd) >= 0
3619 Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd));
3623 Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0;
3626 end Known_Non_Negative;
3628 --------------------
3629 -- Known_Non_Null --
3630 --------------------
3632 function Known_Non_Null (N : Node_Id) return Boolean is
3634 -- Checks for case where N is an entity reference
3636 if Is_Entity_Name (N) and then Present (Entity (N)) then
3638 E : constant Entity_Id := Entity (N);
3643 -- First check if we are in decisive conditional
3645 Get_Current_Value_Condition (N, Op, Val);
3647 if Known_Null (Val) then
3648 if Op = N_Op_Eq then
3650 elsif Op = N_Op_Ne then
3655 -- If OK to do replacement, test Is_Known_Non_Null flag
3657 if OK_To_Do_Constant_Replacement (E) then
3658 return Is_Known_Non_Null (E);
3660 -- Otherwise if not safe to do replacement, then say so
3667 -- True if access attribute
3669 elsif Nkind (N) = N_Attribute_Reference
3670 and then (Attribute_Name (N) = Name_Access
3672 Attribute_Name (N) = Name_Unchecked_Access
3674 Attribute_Name (N) = Name_Unrestricted_Access)
3678 -- True if allocator
3680 elsif Nkind (N) = N_Allocator then
3683 -- For a conversion, true if expression is known non-null
3685 elsif Nkind (N) = N_Type_Conversion then
3686 return Known_Non_Null (Expression (N));
3688 -- Above are all cases where the value could be determined to be
3689 -- non-null. In all other cases, we don't know, so return False.
3700 function Known_Null (N : Node_Id) return Boolean is
3702 -- Checks for case where N is an entity reference
3704 if Is_Entity_Name (N) and then Present (Entity (N)) then
3706 E : constant Entity_Id := Entity (N);
3711 -- Constant null value is for sure null
3713 if Ekind (E) = E_Constant
3714 and then Known_Null (Constant_Value (E))
3719 -- First check if we are in decisive conditional
3721 Get_Current_Value_Condition (N, Op, Val);
3723 if Known_Null (Val) then
3724 if Op = N_Op_Eq then
3726 elsif Op = N_Op_Ne then
3731 -- If OK to do replacement, test Is_Known_Null flag
3733 if OK_To_Do_Constant_Replacement (E) then
3734 return Is_Known_Null (E);
3736 -- Otherwise if not safe to do replacement, then say so
3743 -- True if explicit reference to null
3745 elsif Nkind (N) = N_Null then
3748 -- For a conversion, true if expression is known null
3750 elsif Nkind (N) = N_Type_Conversion then
3751 return Known_Null (Expression (N));
3753 -- Above are all cases where the value could be determined to be null.
3754 -- In all other cases, we don't know, so return False.
3761 -----------------------------
3762 -- Make_CW_Equivalent_Type --
3763 -----------------------------
3765 -- Create a record type used as an equivalent of any member of the class
3766 -- which takes its size from exp.
3768 -- Generate the following code:
3770 -- type Equiv_T is record
3771 -- _parent : T (List of discriminant constraints taken from Exp);
3772 -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
3775 -- ??? Note that this type does not guarantee same alignment as all
3778 function Make_CW_Equivalent_Type
3780 E : Node_Id) return Entity_Id
3782 Loc : constant Source_Ptr := Sloc (E);
3783 Root_Typ : constant Entity_Id := Root_Type (T);
3784 List_Def : constant List_Id := Empty_List;
3785 Comp_List : constant List_Id := New_List;
3786 Equiv_Type : Entity_Id;
3787 Range_Type : Entity_Id;
3788 Str_Type : Entity_Id;
3789 Constr_Root : Entity_Id;
3793 -- If the root type is already constrained, there are no discriminants
3794 -- in the expression.
3796 if not Has_Discriminants (Root_Typ)
3797 or else Is_Constrained (Root_Typ)
3799 Constr_Root := Root_Typ;
3801 Constr_Root := Make_Temporary (Loc, 'R');
3803 -- subtype cstr__n is T (List of discr constraints taken from Exp)
3805 Append_To (List_Def,
3806 Make_Subtype_Declaration (Loc,
3807 Defining_Identifier => Constr_Root,
3808 Subtype_Indication => Make_Subtype_From_Expr (E, Root_Typ)));
3811 -- Generate the range subtype declaration
3813 Range_Type := Make_Temporary (Loc, 'G');
3815 if not Is_Interface (Root_Typ) then
3817 -- subtype rg__xx is
3818 -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit
3821 Make_Op_Subtract (Loc,
3823 Make_Attribute_Reference (Loc,
3825 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3826 Attribute_Name => Name_Size),
3828 Make_Attribute_Reference (Loc,
3829 Prefix => New_Reference_To (Constr_Root, Loc),
3830 Attribute_Name => Name_Object_Size));
3832 -- subtype rg__xx is
3833 -- Storage_Offset range 1 .. Expr'size / Storage_Unit
3836 Make_Attribute_Reference (Loc,
3838 OK_Convert_To (T, Duplicate_Subexpr_No_Checks (E)),
3839 Attribute_Name => Name_Size);
3842 Set_Paren_Count (Sizexpr, 1);
3844 Append_To (List_Def,
3845 Make_Subtype_Declaration (Loc,
3846 Defining_Identifier => Range_Type,
3847 Subtype_Indication =>
3848 Make_Subtype_Indication (Loc,
3849 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc),
3850 Constraint => Make_Range_Constraint (Loc,
3853 Low_Bound => Make_Integer_Literal (Loc, 1),
3855 Make_Op_Divide (Loc,
3856 Left_Opnd => Sizexpr,
3857 Right_Opnd => Make_Integer_Literal (Loc,
3858 Intval => System_Storage_Unit)))))));
3860 -- subtype str__nn is Storage_Array (rg__x);
3862 Str_Type := Make_Temporary (Loc, 'S');
3863 Append_To (List_Def,
3864 Make_Subtype_Declaration (Loc,
3865 Defining_Identifier => Str_Type,
3866 Subtype_Indication =>
3867 Make_Subtype_Indication (Loc,
3868 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc),
3870 Make_Index_Or_Discriminant_Constraint (Loc,
3872 New_List (New_Reference_To (Range_Type, Loc))))));
3874 -- type Equiv_T is record
3875 -- [ _parent : Tnn; ]
3879 Equiv_Type := Make_Temporary (Loc, 'T');
3880 Set_Ekind (Equiv_Type, E_Record_Type);
3881 Set_Parent_Subtype (Equiv_Type, Constr_Root);
3883 -- Set Is_Class_Wide_Equivalent_Type very early to trigger the special
3884 -- treatment for this type. In particular, even though _parent's type
3885 -- is a controlled type or contains controlled components, we do not
3886 -- want to set Has_Controlled_Component on it to avoid making it gain
3887 -- an unwanted _controller component.
3889 Set_Is_Class_Wide_Equivalent_Type (Equiv_Type);
3891 if not Is_Interface (Root_Typ) then
3892 Append_To (Comp_List,
3893 Make_Component_Declaration (Loc,
3894 Defining_Identifier =>
3895 Make_Defining_Identifier (Loc, Name_uParent),
3896 Component_Definition =>
3897 Make_Component_Definition (Loc,
3898 Aliased_Present => False,
3899 Subtype_Indication => New_Reference_To (Constr_Root, Loc))));
3902 Append_To (Comp_List,
3903 Make_Component_Declaration (Loc,
3904 Defining_Identifier => Make_Temporary (Loc, 'C'),
3905 Component_Definition =>
3906 Make_Component_Definition (Loc,
3907 Aliased_Present => False,
3908 Subtype_Indication => New_Reference_To (Str_Type, Loc))));
3910 Append_To (List_Def,
3911 Make_Full_Type_Declaration (Loc,
3912 Defining_Identifier => Equiv_Type,
3914 Make_Record_Definition (Loc,
3916 Make_Component_List (Loc,
3917 Component_Items => Comp_List,
3918 Variant_Part => Empty))));
3920 -- Suppress all checks during the analysis of the expanded code
3921 -- to avoid the generation of spurious warnings under ZFP run-time.
3923 Insert_Actions (E, List_Def, Suppress => All_Checks);
3925 end Make_CW_Equivalent_Type;
3927 ------------------------
3928 -- Make_Literal_Range --
3929 ------------------------
3931 function Make_Literal_Range
3933 Literal_Typ : Entity_Id) return Node_Id
3935 Lo : constant Node_Id :=
3936 New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
3937 Index : constant Entity_Id := Etype (Lo);
3940 Length_Expr : constant Node_Id :=
3941 Make_Op_Subtract (Loc,
3943 Make_Integer_Literal (Loc,
3944 Intval => String_Literal_Length (Literal_Typ)),
3946 Make_Integer_Literal (Loc, 1));
3949 Set_Analyzed (Lo, False);
3951 if Is_Integer_Type (Index) then
3954 Left_Opnd => New_Copy_Tree (Lo),
3955 Right_Opnd => Length_Expr);
3958 Make_Attribute_Reference (Loc,
3959 Attribute_Name => Name_Val,
3960 Prefix => New_Occurrence_Of (Index, Loc),
3961 Expressions => New_List (
3964 Make_Attribute_Reference (Loc,
3965 Attribute_Name => Name_Pos,
3966 Prefix => New_Occurrence_Of (Index, Loc),
3967 Expressions => New_List (New_Copy_Tree (Lo))),
3968 Right_Opnd => Length_Expr)));
3975 end Make_Literal_Range;
3977 --------------------------
3978 -- Make_Non_Empty_Check --
3979 --------------------------
3981 function Make_Non_Empty_Check
3983 N : Node_Id) return Node_Id
3989 Make_Attribute_Reference (Loc,
3990 Attribute_Name => Name_Length,
3991 Prefix => Duplicate_Subexpr_No_Checks (N, Name_Req => True)),
3993 Make_Integer_Literal (Loc, 0));
3994 end Make_Non_Empty_Check;
3996 ----------------------------
3997 -- Make_Subtype_From_Expr --
3998 ----------------------------
4000 -- 1. If Expr is an unconstrained array expression, creates
4001 -- Unc_Type(Expr'first(1)..Expr'last(1),..., Expr'first(n)..Expr'last(n))
4003 -- 2. If Expr is a unconstrained discriminated type expression, creates
4004 -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
4006 -- 3. If Expr is class-wide, creates an implicit class wide subtype
4008 function Make_Subtype_From_Expr
4010 Unc_Typ : Entity_Id) return Node_Id
4012 Loc : constant Source_Ptr := Sloc (E);
4013 List_Constr : constant List_Id := New_List;
4016 Full_Subtyp : Entity_Id;
4017 Priv_Subtyp : Entity_Id;
4022 if Is_Private_Type (Unc_Typ)
4023 and then Has_Unknown_Discriminants (Unc_Typ)
4025 -- Prepare the subtype completion, Go to base type to
4026 -- find underlying type, because the type may be a generic
4027 -- actual or an explicit subtype.
4029 Utyp := Underlying_Type (Base_Type (Unc_Typ));
4030 Full_Subtyp := Make_Temporary (Loc, 'C');
4032 Unchecked_Convert_To (Utyp, Duplicate_Subexpr_No_Checks (E));
4033 Set_Parent (Full_Exp, Parent (E));
4035 Priv_Subtyp := Make_Temporary (Loc, 'P');
4038 Make_Subtype_Declaration (Loc,
4039 Defining_Identifier => Full_Subtyp,
4040 Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
4042 -- Define the dummy private subtype
4044 Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
4045 Set_Etype (Priv_Subtyp, Base_Type (Unc_Typ));
4046 Set_Scope (Priv_Subtyp, Full_Subtyp);
4047 Set_Is_Constrained (Priv_Subtyp);
4048 Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
4049 Set_Is_Itype (Priv_Subtyp);
4050 Set_Associated_Node_For_Itype (Priv_Subtyp, E);
4052 if Is_Tagged_Type (Priv_Subtyp) then
4054 (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
4055 Set_Primitive_Operations (Priv_Subtyp,
4056 Primitive_Operations (Unc_Typ));
4059 Set_Full_View (Priv_Subtyp, Full_Subtyp);
4061 return New_Reference_To (Priv_Subtyp, Loc);
4063 elsif Is_Array_Type (Unc_Typ) then
4064 for J in 1 .. Number_Dimensions (Unc_Typ) loop
4065 Append_To (List_Constr,
4068 Make_Attribute_Reference (Loc,
4069 Prefix => Duplicate_Subexpr_No_Checks (E),
4070 Attribute_Name => Name_First,
4071 Expressions => New_List (
4072 Make_Integer_Literal (Loc, J))),
4075 Make_Attribute_Reference (Loc,
4076 Prefix => Duplicate_Subexpr_No_Checks (E),
4077 Attribute_Name => Name_Last,
4078 Expressions => New_List (
4079 Make_Integer_Literal (Loc, J)))));
4082 elsif Is_Class_Wide_Type (Unc_Typ) then
4084 CW_Subtype : Entity_Id;
4085 EQ_Typ : Entity_Id := Empty;
4088 -- A class-wide equivalent type is not needed when VM_Target
4089 -- because the VM back-ends handle the class-wide object
4090 -- initialization itself (and doesn't need or want the
4091 -- additional intermediate type to handle the assignment).
4093 if Expander_Active and then Tagged_Type_Expansion then
4095 -- If this is the class_wide type of a completion that is
4096 -- a record subtype, set the type of the class_wide type
4097 -- to be the full base type, for use in the expanded code
4098 -- for the equivalent type. Should this be done earlier when
4099 -- the completion is analyzed ???
4101 if Is_Private_Type (Etype (Unc_Typ))
4103 Ekind (Full_View (Etype (Unc_Typ))) = E_Record_Subtype
4105 Set_Etype (Unc_Typ, Base_Type (Full_View (Etype (Unc_Typ))));
4108 EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
4111 CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
4112 Set_Equivalent_Type (CW_Subtype, EQ_Typ);
4113 Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
4115 return New_Occurrence_Of (CW_Subtype, Loc);
4118 -- Indefinite record type with discriminants
4121 D := First_Discriminant (Unc_Typ);
4122 while Present (D) loop
4123 Append_To (List_Constr,
4124 Make_Selected_Component (Loc,
4125 Prefix => Duplicate_Subexpr_No_Checks (E),
4126 Selector_Name => New_Reference_To (D, Loc)));
4128 Next_Discriminant (D);
4133 Make_Subtype_Indication (Loc,
4134 Subtype_Mark => New_Reference_To (Unc_Typ, Loc),
4136 Make_Index_Or_Discriminant_Constraint (Loc,
4137 Constraints => List_Constr));
4138 end Make_Subtype_From_Expr;
4140 -----------------------------
4141 -- May_Generate_Large_Temp --
4142 -----------------------------
4144 -- At the current time, the only types that we return False for (i.e.
4145 -- where we decide we know they cannot generate large temps) are ones
4146 -- where we know the size is 256 bits or less at compile time, and we
4147 -- are still not doing a thorough job on arrays and records ???
4149 function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
4151 if not Size_Known_At_Compile_Time (Typ) then
4154 elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then
4157 elsif Is_Array_Type (Typ)
4158 and then Present (Packed_Array_Type (Typ))
4160 return May_Generate_Large_Temp (Packed_Array_Type (Typ));
4162 -- We could do more here to find other small types ???
4167 end May_Generate_Large_Temp;
4169 ----------------------------
4170 -- Needs_Constant_Address --
4171 ----------------------------
4173 function Needs_Constant_Address
4175 Typ : Entity_Id) return Boolean
4179 -- If we have no initialization of any kind, then we don't need to
4180 -- place any restrictions on the address clause, because the object
4181 -- will be elaborated after the address clause is evaluated. This
4182 -- happens if the declaration has no initial expression, or the type
4183 -- has no implicit initialization, or the object is imported.
4185 -- The same holds for all initialized scalar types and all access
4186 -- types. Packed bit arrays of size up to 64 are represented using a
4187 -- modular type with an initialization (to zero) and can be processed
4188 -- like other initialized scalar types.
4190 -- If the type is controlled, code to attach the object to a
4191 -- finalization chain is generated at the point of declaration,
4192 -- and therefore the elaboration of the object cannot be delayed:
4193 -- the address expression must be a constant.
4195 if No (Expression (Decl))
4196 and then not Needs_Finalization (Typ)
4198 (not Has_Non_Null_Base_Init_Proc (Typ)
4199 or else Is_Imported (Defining_Identifier (Decl)))
4203 elsif (Present (Expression (Decl)) and then Is_Scalar_Type (Typ))
4204 or else Is_Access_Type (Typ)
4206 (Is_Bit_Packed_Array (Typ)
4207 and then Is_Modular_Integer_Type (Packed_Array_Type (Typ)))
4213 -- Otherwise, we require the address clause to be constant because
4214 -- the call to the initialization procedure (or the attach code) has
4215 -- to happen at the point of the declaration.
4217 -- Actually the IP call has been moved to the freeze actions
4218 -- anyway, so maybe we can relax this restriction???
4222 end Needs_Constant_Address;
4224 ----------------------------
4225 -- New_Class_Wide_Subtype --
4226 ----------------------------
4228 function New_Class_Wide_Subtype
4229 (CW_Typ : Entity_Id;
4230 N : Node_Id) return Entity_Id
4232 Res : constant Entity_Id := Create_Itype (E_Void, N);
4233 Res_Name : constant Name_Id := Chars (Res);
4234 Res_Scope : constant Entity_Id := Scope (Res);
4237 Copy_Node (CW_Typ, Res);
4238 Set_Comes_From_Source (Res, False);
4239 Set_Sloc (Res, Sloc (N));
4241 Set_Associated_Node_For_Itype (Res, N);
4242 Set_Is_Public (Res, False); -- By default, may be changed below.
4243 Set_Public_Status (Res);
4244 Set_Chars (Res, Res_Name);
4245 Set_Scope (Res, Res_Scope);
4246 Set_Ekind (Res, E_Class_Wide_Subtype);
4247 Set_Next_Entity (Res, Empty);
4248 Set_Etype (Res, Base_Type (CW_Typ));
4249 Set_Is_Frozen (Res, False);
4250 Set_Freeze_Node (Res, Empty);
4252 end New_Class_Wide_Subtype;
4254 --------------------------------
4255 -- Non_Limited_Designated_Type --
4256 ---------------------------------
4258 function Non_Limited_Designated_Type (T : Entity_Id) return Entity_Id is
4259 Desig : constant Entity_Id := Designated_Type (T);
4261 if Ekind (Desig) = E_Incomplete_Type
4262 and then Present (Non_Limited_View (Desig))
4264 return Non_Limited_View (Desig);
4268 end Non_Limited_Designated_Type;
4270 -----------------------------------
4271 -- OK_To_Do_Constant_Replacement --
4272 -----------------------------------
4274 function OK_To_Do_Constant_Replacement (E : Entity_Id) return Boolean is
4275 ES : constant Entity_Id := Scope (E);
4279 -- Do not replace statically allocated objects, because they may be
4280 -- modified outside the current scope.
4282 if Is_Statically_Allocated (E) then
4285 -- Do not replace aliased or volatile objects, since we don't know what
4286 -- else might change the value.
4288 elsif Is_Aliased (E) or else Treat_As_Volatile (E) then
4291 -- Debug flag -gnatdM disconnects this optimization
4293 elsif Debug_Flag_MM then
4296 -- Otherwise check scopes
4299 CS := Current_Scope;
4302 -- If we are in right scope, replacement is safe
4307 -- Packages do not affect the determination of safety
4309 elsif Ekind (CS) = E_Package then
4310 exit when CS = Standard_Standard;
4313 -- Blocks do not affect the determination of safety
4315 elsif Ekind (CS) = E_Block then
4318 -- Loops do not affect the determination of safety. Note that we
4319 -- kill all current values on entry to a loop, so we are just
4320 -- talking about processing within a loop here.
4322 elsif Ekind (CS) = E_Loop then
4325 -- Otherwise, the reference is dubious, and we cannot be sure that
4326 -- it is safe to do the replacement.
4335 end OK_To_Do_Constant_Replacement;
4337 ------------------------------------
4338 -- Possible_Bit_Aligned_Component --
4339 ------------------------------------
4341 function Possible_Bit_Aligned_Component (N : Node_Id) return Boolean is
4345 -- Case of indexed component
4347 when N_Indexed_Component =>
4349 P : constant Node_Id := Prefix (N);
4350 Ptyp : constant Entity_Id := Etype (P);
4353 -- If we know the component size and it is less than 64, then
4354 -- we are definitely OK. The back end always does assignment of
4355 -- misaligned small objects correctly.
4357 if Known_Static_Component_Size (Ptyp)
4358 and then Component_Size (Ptyp) <= 64
4362 -- Otherwise, we need to test the prefix, to see if we are
4363 -- indexing from a possibly unaligned component.
4366 return Possible_Bit_Aligned_Component (P);
4370 -- Case of selected component
4372 when N_Selected_Component =>
4374 P : constant Node_Id := Prefix (N);
4375 Comp : constant Entity_Id := Entity (Selector_Name (N));
4378 -- If there is no component clause, then we are in the clear
4379 -- since the back end will never misalign a large component
4380 -- unless it is forced to do so. In the clear means we need
4381 -- only the recursive test on the prefix.
4383 if Component_May_Be_Bit_Aligned (Comp) then
4386 return Possible_Bit_Aligned_Component (P);
4390 -- For a slice, test the prefix, if that is possibly misaligned,
4391 -- then for sure the slice is!
4394 return Possible_Bit_Aligned_Component (Prefix (N));
4396 -- If we have none of the above, it means that we have fallen off the
4397 -- top testing prefixes recursively, and we now have a stand alone
4398 -- object, where we don't have a problem.
4404 end Possible_Bit_Aligned_Component;
4406 -------------------------
4407 -- Remove_Side_Effects --
4408 -------------------------
4410 procedure Remove_Side_Effects
4412 Name_Req : Boolean := False;
4413 Variable_Ref : Boolean := False)
4415 Loc : constant Source_Ptr := Sloc (Exp);
4416 Exp_Type : constant Entity_Id := Etype (Exp);
4417 Svg_Suppress : constant Suppress_Array := Scope_Suppress;
4419 Ref_Type : Entity_Id;
4421 Ptr_Typ_Decl : Node_Id;
4425 function Side_Effect_Free (N : Node_Id) return Boolean;
4426 -- Determines if the tree N represents an expression that is known not
4427 -- to have side effects, and for which no processing is required.
4429 function Side_Effect_Free (L : List_Id) return Boolean;
4430 -- Determines if all elements of the list L are side effect free
4432 function Safe_Prefixed_Reference (N : Node_Id) return Boolean;
4433 -- The argument N is a construct where the Prefix is dereferenced if it
4434 -- is an access type and the result is a variable. The call returns True
4435 -- if the construct is side effect free (not considering side effects in
4436 -- other than the prefix which are to be tested by the caller).
4438 function Within_In_Parameter (N : Node_Id) return Boolean;
4439 -- Determines if N is a subcomponent of a composite in-parameter. If so,
4440 -- N is not side-effect free when the actual is global and modifiable
4441 -- indirectly from within a subprogram, because it may be passed by
4442 -- reference. The front-end must be conservative here and assume that
4443 -- this may happen with any array or record type. On the other hand, we
4444 -- cannot create temporaries for all expressions for which this
4445 -- condition is true, for various reasons that might require clearing up
4446 -- ??? For example, discriminant references that appear out of place, or
4447 -- spurious type errors with class-wide expressions. As a result, we
4448 -- limit the transformation to loop bounds, which is so far the only
4449 -- case that requires it.
4451 -----------------------------
4452 -- Safe_Prefixed_Reference --
4453 -----------------------------
4455 function Safe_Prefixed_Reference (N : Node_Id) return Boolean is
4457 -- If prefix is not side effect free, definitely not safe
4459 if not Side_Effect_Free (Prefix (N)) then
4462 -- If the prefix is of an access type that is not access-to-constant,
4463 -- then this construct is a variable reference, which means it is to
4464 -- be considered to have side effects if Variable_Ref is set True
4465 -- Exception is an access to an entity that is a constant or an
4466 -- in-parameter which does not come from source, and is the result
4467 -- of a previous removal of side-effects.
4469 elsif Is_Access_Type (Etype (Prefix (N)))
4470 and then not Is_Access_Constant (Etype (Prefix (N)))
4471 and then Variable_Ref
4473 if not Is_Entity_Name (Prefix (N)) then
4476 return Ekind (Entity (Prefix (N))) = E_Constant
4477 or else Ekind (Entity (Prefix (N))) = E_In_Parameter;
4480 -- The following test is the simplest way of solving a complex
4481 -- problem uncovered by BB08-010: Side effect on loop bound that
4482 -- is a subcomponent of a global variable:
4483 -- If a loop bound is a subcomponent of a global variable, a
4484 -- modification of that variable within the loop may incorrectly
4485 -- affect the execution of the loop.
4488 (Nkind (Parent (Parent (N))) /= N_Loop_Parameter_Specification
4489 or else not Within_In_Parameter (Prefix (N)))
4493 -- All other cases are side effect free
4498 end Safe_Prefixed_Reference;
4500 ----------------------
4501 -- Side_Effect_Free --
4502 ----------------------
4504 function Side_Effect_Free (N : Node_Id) return Boolean is
4506 -- Note on checks that could raise Constraint_Error. Strictly, if
4507 -- we take advantage of 11.6, these checks do not count as side
4508 -- effects. However, we would just as soon consider that they are
4509 -- side effects, since the backend CSE does not work very well on
4510 -- expressions which can raise Constraint_Error. On the other
4511 -- hand, if we do not consider them to be side effect free, then
4512 -- we get some awkward expansions in -gnato mode, resulting in
4513 -- code insertions at a point where we do not have a clear model
4514 -- for performing the insertions.
4516 -- Special handling for entity names
4518 if Is_Entity_Name (N) then
4520 -- If the entity is a constant, it is definitely side effect
4521 -- free. Note that the test of Is_Variable (N) below might
4522 -- be expected to catch this case, but it does not, because
4523 -- this test goes to the original tree, and we may have
4524 -- already rewritten a variable node with a constant as
4525 -- a result of an earlier Force_Evaluation call.
4527 if Ekind_In (Entity (N), E_Constant, E_In_Parameter) then
4530 -- Functions are not side effect free
4532 elsif Ekind (Entity (N)) = E_Function then
4535 -- Variables are considered to be a side effect if Variable_Ref
4536 -- is set or if we have a volatile reference and Name_Req is off.
4537 -- If Name_Req is True then we can't help returning a name which
4538 -- effectively allows multiple references in any case.
4540 elsif Is_Variable (N) then
4541 return not Variable_Ref
4542 and then (not Is_Volatile_Reference (N) or else Name_Req);
4544 -- Any other entity (e.g. a subtype name) is definitely side
4551 -- A value known at compile time is always side effect free
4553 elsif Compile_Time_Known_Value (N) then
4556 -- A variable renaming is not side-effect free, because the
4557 -- renaming will function like a macro in the front-end in
4558 -- some cases, and an assignment can modify the component
4559 -- designated by N, so we need to create a temporary for it.
4561 elsif Is_Entity_Name (Original_Node (N))
4562 and then Is_Renaming_Of_Object (Entity (Original_Node (N)))
4563 and then Ekind (Entity (Original_Node (N))) /= E_Constant
4568 -- For other than entity names and compile time known values,
4569 -- check the node kind for special processing.
4573 -- An attribute reference is side effect free if its expressions
4574 -- are side effect free and its prefix is side effect free or
4575 -- is an entity reference.
4577 -- Is this right? what about x'first where x is a variable???
4579 when N_Attribute_Reference =>
4580 return Side_Effect_Free (Expressions (N))
4581 and then Attribute_Name (N) /= Name_Input
4582 and then (Is_Entity_Name (Prefix (N))
4583 or else Side_Effect_Free (Prefix (N)));
4585 -- A binary operator is side effect free if and both operands
4586 -- are side effect free. For this purpose binary operators
4587 -- include membership tests and short circuit forms
4589 when N_Binary_Op | N_Membership_Test | N_Short_Circuit =>
4590 return Side_Effect_Free (Left_Opnd (N))
4592 Side_Effect_Free (Right_Opnd (N));
4594 -- An explicit dereference is side effect free only if it is
4595 -- a side effect free prefixed reference.
4597 when N_Explicit_Dereference =>
4598 return Safe_Prefixed_Reference (N);
4600 -- A call to _rep_to_pos is side effect free, since we generate
4601 -- this pure function call ourselves. Moreover it is critically
4602 -- important to make this exception, since otherwise we can
4603 -- have discriminants in array components which don't look
4604 -- side effect free in the case of an array whose index type
4605 -- is an enumeration type with an enumeration rep clause.
4607 -- All other function calls are not side effect free
4609 when N_Function_Call =>
4610 return Nkind (Name (N)) = N_Identifier
4611 and then Is_TSS (Name (N), TSS_Rep_To_Pos)
4613 Side_Effect_Free (First (Parameter_Associations (N)));
4615 -- An indexed component is side effect free if it is a side
4616 -- effect free prefixed reference and all the indexing
4617 -- expressions are side effect free.
4619 when N_Indexed_Component =>
4620 return Side_Effect_Free (Expressions (N))
4621 and then Safe_Prefixed_Reference (N);
4623 -- A type qualification is side effect free if the expression
4624 -- is side effect free.
4626 when N_Qualified_Expression =>
4627 return Side_Effect_Free (Expression (N));
4629 -- A selected component is side effect free only if it is a
4630 -- side effect free prefixed reference. If it designates a
4631 -- component with a rep. clause it must be treated has having
4632 -- a potential side effect, because it may be modified through
4633 -- a renaming, and a subsequent use of the renaming as a macro
4634 -- will yield the wrong value. This complex interaction between
4635 -- renaming and removing side effects is a reminder that the
4636 -- latter has become a headache to maintain, and that it should
4637 -- be removed in favor of the gcc mechanism to capture values ???
4639 when N_Selected_Component =>
4640 if Nkind (Parent (N)) = N_Explicit_Dereference
4641 and then Has_Non_Standard_Rep (Designated_Type (Etype (N)))
4645 return Safe_Prefixed_Reference (N);
4648 -- A range is side effect free if the bounds are side effect free
4651 return Side_Effect_Free (Low_Bound (N))
4652 and then Side_Effect_Free (High_Bound (N));
4654 -- A slice is side effect free if it is a side effect free
4655 -- prefixed reference and the bounds are side effect free.
4658 return Side_Effect_Free (Discrete_Range (N))
4659 and then Safe_Prefixed_Reference (N);
4661 -- A type conversion is side effect free if the expression to be
4662 -- converted is side effect free.
4664 when N_Type_Conversion =>
4665 return Side_Effect_Free (Expression (N));
4667 -- A unary operator is side effect free if the operand
4668 -- is side effect free.
4671 return Side_Effect_Free (Right_Opnd (N));
4673 -- An unchecked type conversion is side effect free only if it
4674 -- is safe and its argument is side effect free.
4676 when N_Unchecked_Type_Conversion =>
4677 return Safe_Unchecked_Type_Conversion (N)
4678 and then Side_Effect_Free (Expression (N));
4680 -- An unchecked expression is side effect free if its expression
4681 -- is side effect free.
4683 when N_Unchecked_Expression =>
4684 return Side_Effect_Free (Expression (N));
4686 -- A literal is side effect free
4688 when N_Character_Literal |
4694 -- We consider that anything else has side effects. This is a bit
4695 -- crude, but we are pretty close for most common cases, and we
4696 -- are certainly correct (i.e. we never return True when the
4697 -- answer should be False).
4702 end Side_Effect_Free;
4704 -- A list is side effect free if all elements of the list are
4705 -- side effect free.
4707 function Side_Effect_Free (L : List_Id) return Boolean is
4711 if L = No_List or else L = Error_List then
4716 while Present (N) loop
4717 if not Side_Effect_Free (N) then
4726 end Side_Effect_Free;
4728 -------------------------
4729 -- Within_In_Parameter --
4730 -------------------------
4732 function Within_In_Parameter (N : Node_Id) return Boolean is
4734 if not Comes_From_Source (N) then
4737 elsif Is_Entity_Name (N) then
4738 return Ekind (Entity (N)) = E_In_Parameter;
4740 elsif Nkind (N) = N_Indexed_Component
4741 or else Nkind (N) = N_Selected_Component
4743 return Within_In_Parameter (Prefix (N));
4748 end Within_In_Parameter;
4750 -- Start of processing for Remove_Side_Effects
4753 -- If we are side effect free already or expansion is disabled,
4754 -- there is nothing to do.
4756 if Side_Effect_Free (Exp) or else not Expander_Active then
4760 -- All this must not have any checks
4762 Scope_Suppress := (others => True);
4764 -- If it is a scalar type and we need to capture the value, just make
4765 -- a copy. Likewise for a function call, an attribute reference, an
4766 -- allocator, or an operator. And if we have a volatile reference and
4767 -- Name_Req is not set (see comments above for Side_Effect_Free).
4769 if Is_Elementary_Type (Exp_Type)
4770 and then (Variable_Ref
4771 or else Nkind (Exp) = N_Function_Call
4772 or else Nkind (Exp) = N_Attribute_Reference
4773 or else Nkind (Exp) = N_Allocator
4774 or else Nkind (Exp) in N_Op
4775 or else (not Name_Req and then Is_Volatile_Reference (Exp)))
4777 Def_Id := Make_Temporary (Loc, 'R', Exp);
4778 Set_Etype (Def_Id, Exp_Type);
4779 Res := New_Reference_To (Def_Id, Loc);
4781 -- If the expression is a packed reference, it must be reanalyzed
4782 -- and expanded, depending on context. This is the case for actuals
4783 -- where a constraint check may capture the actual before expansion
4784 -- of the call is complete.
4786 if Nkind (Exp) = N_Indexed_Component
4787 and then Is_Packed (Etype (Prefix (Exp)))
4789 Set_Analyzed (Exp, False);
4790 Set_Analyzed (Prefix (Exp), False);
4794 Make_Object_Declaration (Loc,
4795 Defining_Identifier => Def_Id,
4796 Object_Definition => New_Reference_To (Exp_Type, Loc),
4797 Constant_Present => True,
4798 Expression => Relocate_Node (Exp));
4800 Set_Assignment_OK (E);
4801 Insert_Action (Exp, E);
4803 -- If the expression has the form v.all then we can just capture
4804 -- the pointer, and then do an explicit dereference on the result.
4806 elsif Nkind (Exp) = N_Explicit_Dereference then
4807 Def_Id := Make_Temporary (Loc, 'R', Exp);
4809 Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc));
4812 Make_Object_Declaration (Loc,
4813 Defining_Identifier => Def_Id,
4814 Object_Definition =>
4815 New_Reference_To (Etype (Prefix (Exp)), Loc),
4816 Constant_Present => True,
4817 Expression => Relocate_Node (Prefix (Exp))));
4819 -- Similar processing for an unchecked conversion of an expression
4820 -- of the form v.all, where we want the same kind of treatment.
4822 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4823 and then Nkind (Expression (Exp)) = N_Explicit_Dereference
4825 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4826 Scope_Suppress := Svg_Suppress;
4829 -- If this is a type conversion, leave the type conversion and remove
4830 -- the side effects in the expression. This is important in several
4831 -- circumstances: for change of representations, and also when this is
4832 -- a view conversion to a smaller object, where gigi can end up creating
4833 -- its own temporary of the wrong size.
4835 elsif Nkind (Exp) = N_Type_Conversion then
4836 Remove_Side_Effects (Expression (Exp), Name_Req, Variable_Ref);
4837 Scope_Suppress := Svg_Suppress;
4840 -- If this is an unchecked conversion that Gigi can't handle, make
4841 -- a copy or a use a renaming to capture the value.
4843 elsif Nkind (Exp) = N_Unchecked_Type_Conversion
4844 and then not Safe_Unchecked_Type_Conversion (Exp)
4846 if CW_Or_Has_Controlled_Part (Exp_Type) then
4848 -- Use a renaming to capture the expression, rather than create
4849 -- a controlled temporary.
4851 Def_Id := Make_Temporary (Loc, 'R', Exp);
4852 Res := New_Reference_To (Def_Id, Loc);
4855 Make_Object_Renaming_Declaration (Loc,
4856 Defining_Identifier => Def_Id,
4857 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4858 Name => Relocate_Node (Exp)));
4861 Def_Id := Make_Temporary (Loc, 'R', Exp);
4862 Set_Etype (Def_Id, Exp_Type);
4863 Res := New_Reference_To (Def_Id, Loc);
4866 Make_Object_Declaration (Loc,
4867 Defining_Identifier => Def_Id,
4868 Object_Definition => New_Reference_To (Exp_Type, Loc),
4869 Constant_Present => not Is_Variable (Exp),
4870 Expression => Relocate_Node (Exp));
4872 Set_Assignment_OK (E);
4873 Insert_Action (Exp, E);
4876 -- For expressions that denote objects, we can use a renaming scheme.
4877 -- This is needed for correctness in the case of a volatile object
4878 -- of a non-volatile type because the Make_Reference call of the
4879 -- "default" approach would generate an illegal access value (an access
4880 -- value cannot designate such an object - see Analyze_Reference).
4881 -- We skip using this scheme if we have an object of a volatile type
4882 -- and we do not have Name_Req set true (see comments above for
4883 -- Side_Effect_Free).
4885 elsif Is_Object_Reference (Exp)
4886 and then Nkind (Exp) /= N_Function_Call
4887 and then (Name_Req or else not Treat_As_Volatile (Exp_Type))
4889 Def_Id := Make_Temporary (Loc, 'R', Exp);
4891 if Nkind (Exp) = N_Selected_Component
4892 and then Nkind (Prefix (Exp)) = N_Function_Call
4893 and then Is_Array_Type (Exp_Type)
4895 -- Avoid generating a variable-sized temporary, by generating
4896 -- the renaming declaration just for the function call. The
4897 -- transformation could be refined to apply only when the array
4898 -- component is constrained by a discriminant???
4901 Make_Selected_Component (Loc,
4902 Prefix => New_Occurrence_Of (Def_Id, Loc),
4903 Selector_Name => Selector_Name (Exp));
4906 Make_Object_Renaming_Declaration (Loc,
4907 Defining_Identifier => Def_Id,
4909 New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc),
4910 Name => Relocate_Node (Prefix (Exp))));
4913 Res := New_Reference_To (Def_Id, Loc);
4916 Make_Object_Renaming_Declaration (Loc,
4917 Defining_Identifier => Def_Id,
4918 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
4919 Name => Relocate_Node (Exp)));
4922 -- If this is a packed reference, or a selected component with a
4923 -- non-standard representation, a reference to the temporary will
4924 -- be replaced by a copy of the original expression (see
4925 -- Exp_Ch2.Expand_Renaming). Otherwise the temporary must be
4926 -- elaborated by gigi, and is of course not to be replaced in-line
4927 -- by the expression it renames, which would defeat the purpose of
4928 -- removing the side-effect.
4930 if (Nkind (Exp) = N_Selected_Component
4931 or else Nkind (Exp) = N_Indexed_Component)
4932 and then Has_Non_Standard_Rep (Etype (Prefix (Exp)))
4936 Set_Is_Renaming_Of_Object (Def_Id, False);
4939 -- Otherwise we generate a reference to the value
4942 -- Special processing for function calls that return a limited type.
4943 -- We need to build a declaration that will enable build-in-place
4944 -- expansion of the call. This is not done if the context is already
4945 -- an object declaration, to prevent infinite recursion.
4947 -- This is relevant only in Ada 2005 mode. In Ada 95 programs we have
4948 -- to accommodate functions returning limited objects by reference.
4950 if Nkind (Exp) = N_Function_Call
4951 and then Is_Inherently_Limited_Type (Etype (Exp))
4952 and then Nkind (Parent (Exp)) /= N_Object_Declaration
4953 and then Ada_Version >= Ada_05
4956 Obj : constant Entity_Id := Make_Temporary (Loc, 'F', Exp);
4961 Make_Object_Declaration (Loc,
4962 Defining_Identifier => Obj,
4963 Object_Definition => New_Occurrence_Of (Exp_Type, Loc),
4964 Expression => Relocate_Node (Exp));
4966 Insert_Action (Exp, Decl);
4967 Set_Etype (Obj, Exp_Type);
4968 Rewrite (Exp, New_Occurrence_Of (Obj, Loc));
4973 Ref_Type := Make_Temporary (Loc, 'A');
4976 Make_Full_Type_Declaration (Loc,
4977 Defining_Identifier => Ref_Type,
4979 Make_Access_To_Object_Definition (Loc,
4980 All_Present => True,
4981 Subtype_Indication =>
4982 New_Reference_To (Exp_Type, Loc)));
4985 Insert_Action (Exp, Ptr_Typ_Decl);
4987 Def_Id := Make_Temporary (Loc, 'R', Exp);
4988 Set_Etype (Def_Id, Exp_Type);
4991 Make_Explicit_Dereference (Loc,
4992 Prefix => New_Reference_To (Def_Id, Loc));
4994 if Nkind (E) = N_Explicit_Dereference then
4995 New_Exp := Relocate_Node (Prefix (E));
4997 E := Relocate_Node (E);
4998 New_Exp := Make_Reference (Loc, E);
5001 if Is_Delayed_Aggregate (E) then
5003 -- The expansion of nested aggregates is delayed until the
5004 -- enclosing aggregate is expanded. As aggregates are often
5005 -- qualified, the predicate applies to qualified expressions
5006 -- as well, indicating that the enclosing aggregate has not
5007 -- been expanded yet. At this point the aggregate is part of
5008 -- a stand-alone declaration, and must be fully expanded.
5010 if Nkind (E) = N_Qualified_Expression then
5011 Set_Expansion_Delayed (Expression (E), False);
5012 Set_Analyzed (Expression (E), False);
5014 Set_Expansion_Delayed (E, False);
5017 Set_Analyzed (E, False);
5021 Make_Object_Declaration (Loc,
5022 Defining_Identifier => Def_Id,
5023 Object_Definition => New_Reference_To (Ref_Type, Loc),
5024 Constant_Present => True,
5025 Expression => New_Exp));
5028 -- Preserve the Assignment_OK flag in all copies, since at least
5029 -- one copy may be used in a context where this flag must be set
5030 -- (otherwise why would the flag be set in the first place).
5032 Set_Assignment_OK (Res, Assignment_OK (Exp));
5034 -- Finally rewrite the original expression and we are done
5037 Analyze_And_Resolve (Exp, Exp_Type);
5038 Scope_Suppress := Svg_Suppress;
5039 end Remove_Side_Effects;
5041 ---------------------------
5042 -- Represented_As_Scalar --
5043 ---------------------------
5045 function Represented_As_Scalar (T : Entity_Id) return Boolean is
5046 UT : constant Entity_Id := Underlying_Type (T);
5048 return Is_Scalar_Type (UT)
5049 or else (Is_Bit_Packed_Array (UT)
5050 and then Is_Scalar_Type (Packed_Array_Type (UT)));
5051 end Represented_As_Scalar;
5053 ------------------------------------
5054 -- Safe_Unchecked_Type_Conversion --
5055 ------------------------------------
5057 -- Note: this function knows quite a bit about the exact requirements
5058 -- of Gigi with respect to unchecked type conversions, and its code
5059 -- must be coordinated with any changes in Gigi in this area.
5061 -- The above requirements should be documented in Sinfo ???
5063 function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
5068 Pexp : constant Node_Id := Parent (Exp);
5071 -- If the expression is the RHS of an assignment or object declaration
5072 -- we are always OK because there will always be a target.
5074 -- Object renaming declarations, (generated for view conversions of
5075 -- actuals in inlined calls), like object declarations, provide an
5076 -- explicit type, and are safe as well.
5078 if (Nkind (Pexp) = N_Assignment_Statement
5079 and then Expression (Pexp) = Exp)
5080 or else Nkind (Pexp) = N_Object_Declaration
5081 or else Nkind (Pexp) = N_Object_Renaming_Declaration
5085 -- If the expression is the prefix of an N_Selected_Component
5086 -- we should also be OK because GCC knows to look inside the
5087 -- conversion except if the type is discriminated. We assume
5088 -- that we are OK anyway if the type is not set yet or if it is
5089 -- controlled since we can't afford to introduce a temporary in
5092 elsif Nkind (Pexp) = N_Selected_Component
5093 and then Prefix (Pexp) = Exp
5095 if No (Etype (Pexp)) then
5099 not Has_Discriminants (Etype (Pexp))
5100 or else Is_Constrained (Etype (Pexp));
5104 -- Set the output type, this comes from Etype if it is set, otherwise
5105 -- we take it from the subtype mark, which we assume was already
5108 if Present (Etype (Exp)) then
5109 Otyp := Etype (Exp);
5111 Otyp := Entity (Subtype_Mark (Exp));
5114 -- The input type always comes from the expression, and we assume
5115 -- this is indeed always analyzed, so we can simply get the Etype.
5117 Ityp := Etype (Expression (Exp));
5119 -- Initialize alignments to unknown so far
5124 -- Replace a concurrent type by its corresponding record type
5125 -- and each type by its underlying type and do the tests on those.
5126 -- The original type may be a private type whose completion is a
5127 -- concurrent type, so find the underlying type first.
5129 if Present (Underlying_Type (Otyp)) then
5130 Otyp := Underlying_Type (Otyp);
5133 if Present (Underlying_Type (Ityp)) then
5134 Ityp := Underlying_Type (Ityp);
5137 if Is_Concurrent_Type (Otyp) then
5138 Otyp := Corresponding_Record_Type (Otyp);
5141 if Is_Concurrent_Type (Ityp) then
5142 Ityp := Corresponding_Record_Type (Ityp);
5145 -- If the base types are the same, we know there is no problem since
5146 -- this conversion will be a noop.
5148 if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
5151 -- Same if this is an upwards conversion of an untagged type, and there
5152 -- are no constraints involved (could be more general???)
5154 elsif Etype (Ityp) = Otyp
5155 and then not Is_Tagged_Type (Ityp)
5156 and then not Has_Discriminants (Ityp)
5157 and then No (First_Rep_Item (Base_Type (Ityp)))
5161 -- If the expression has an access type (object or subprogram) we
5162 -- assume that the conversion is safe, because the size of the target
5163 -- is safe, even if it is a record (which might be treated as having
5164 -- unknown size at this point).
5166 elsif Is_Access_Type (Ityp) then
5169 -- If the size of output type is known at compile time, there is
5170 -- never a problem. Note that unconstrained records are considered
5171 -- to be of known size, but we can't consider them that way here,
5172 -- because we are talking about the actual size of the object.
5174 -- We also make sure that in addition to the size being known, we do
5175 -- not have a case which might generate an embarrassingly large temp
5176 -- in stack checking mode.
5178 elsif Size_Known_At_Compile_Time (Otyp)
5180 (not Stack_Checking_Enabled
5181 or else not May_Generate_Large_Temp (Otyp))
5182 and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
5186 -- If either type is tagged, then we know the alignment is OK so
5187 -- Gigi will be able to use pointer punning.
5189 elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
5192 -- If either type is a limited record type, we cannot do a copy, so
5193 -- say safe since there's nothing else we can do.
5195 elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
5198 -- Conversions to and from packed array types are always ignored and
5201 elsif Is_Packed_Array_Type (Otyp)
5202 or else Is_Packed_Array_Type (Ityp)
5207 -- The only other cases known to be safe is if the input type's
5208 -- alignment is known to be at least the maximum alignment for the
5209 -- target or if both alignments are known and the output type's
5210 -- alignment is no stricter than the input's. We can use the alignment
5211 -- of the component type of an array if a type is an unpacked
5214 if Present (Alignment_Clause (Otyp)) then
5215 Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
5217 elsif Is_Array_Type (Otyp)
5218 and then Present (Alignment_Clause (Component_Type (Otyp)))
5220 Oalign := Expr_Value (Expression (Alignment_Clause
5221 (Component_Type (Otyp))));
5224 if Present (Alignment_Clause (Ityp)) then
5225 Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
5227 elsif Is_Array_Type (Ityp)
5228 and then Present (Alignment_Clause (Component_Type (Ityp)))
5230 Ialign := Expr_Value (Expression (Alignment_Clause
5231 (Component_Type (Ityp))));
5234 if Ialign /= No_Uint and then Ialign > Maximum_Alignment then
5237 elsif Ialign /= No_Uint and then Oalign /= No_Uint
5238 and then Ialign <= Oalign
5242 -- Otherwise, Gigi cannot handle this and we must make a temporary
5247 end Safe_Unchecked_Type_Conversion;
5249 ---------------------------------
5250 -- Set_Current_Value_Condition --
5251 ---------------------------------
5253 -- Note: the implementation of this procedure is very closely tied to the
5254 -- implementation of Get_Current_Value_Condition. Here we set required
5255 -- Current_Value fields, and in Get_Current_Value_Condition, we interpret
5256 -- them, so they must have a consistent view.
5258 procedure Set_Current_Value_Condition (Cnode : Node_Id) is
5260 procedure Set_Entity_Current_Value (N : Node_Id);
5261 -- If N is an entity reference, where the entity is of an appropriate
5262 -- kind, then set the current value of this entity to Cnode, unless
5263 -- there is already a definite value set there.
5265 procedure Set_Expression_Current_Value (N : Node_Id);
5266 -- If N is of an appropriate form, sets an appropriate entry in current
5267 -- value fields of relevant entities. Multiple entities can be affected
5268 -- in the case of an AND or AND THEN.
5270 ------------------------------
5271 -- Set_Entity_Current_Value --
5272 ------------------------------
5274 procedure Set_Entity_Current_Value (N : Node_Id) is
5276 if Is_Entity_Name (N) then
5278 Ent : constant Entity_Id := Entity (N);
5281 -- Don't capture if not safe to do so
5283 if not Safe_To_Capture_Value (N, Ent, Cond => True) then
5287 -- Here we have a case where the Current_Value field may
5288 -- need to be set. We set it if it is not already set to a
5289 -- compile time expression value.
5291 -- Note that this represents a decision that one condition
5292 -- blots out another previous one. That's certainly right
5293 -- if they occur at the same level. If the second one is
5294 -- nested, then the decision is neither right nor wrong (it
5295 -- would be equally OK to leave the outer one in place, or
5296 -- take the new inner one. Really we should record both, but
5297 -- our data structures are not that elaborate.
5299 if Nkind (Current_Value (Ent)) not in N_Subexpr then
5300 Set_Current_Value (Ent, Cnode);
5304 end Set_Entity_Current_Value;
5306 ----------------------------------
5307 -- Set_Expression_Current_Value --
5308 ----------------------------------
5310 procedure Set_Expression_Current_Value (N : Node_Id) is
5316 -- Loop to deal with (ignore for now) any NOT operators present. The
5317 -- presence of NOT operators will be handled properly when we call
5318 -- Get_Current_Value_Condition.
5320 while Nkind (Cond) = N_Op_Not loop
5321 Cond := Right_Opnd (Cond);
5324 -- For an AND or AND THEN, recursively process operands
5326 if Nkind (Cond) = N_Op_And or else Nkind (Cond) = N_And_Then then
5327 Set_Expression_Current_Value (Left_Opnd (Cond));
5328 Set_Expression_Current_Value (Right_Opnd (Cond));
5332 -- Check possible relational operator
5334 if Nkind (Cond) in N_Op_Compare then
5335 if Compile_Time_Known_Value (Right_Opnd (Cond)) then
5336 Set_Entity_Current_Value (Left_Opnd (Cond));
5337 elsif Compile_Time_Known_Value (Left_Opnd (Cond)) then
5338 Set_Entity_Current_Value (Right_Opnd (Cond));
5341 -- Check possible boolean variable reference
5344 Set_Entity_Current_Value (Cond);
5346 end Set_Expression_Current_Value;
5348 -- Start of processing for Set_Current_Value_Condition
5351 Set_Expression_Current_Value (Condition (Cnode));
5352 end Set_Current_Value_Condition;
5354 --------------------------
5355 -- Set_Elaboration_Flag --
5356 --------------------------
5358 procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
5359 Loc : constant Source_Ptr := Sloc (N);
5360 Ent : constant Entity_Id := Elaboration_Entity (Spec_Id);
5364 if Present (Ent) then
5366 -- Nothing to do if at the compilation unit level, because in this
5367 -- case the flag is set by the binder generated elaboration routine.
5369 if Nkind (Parent (N)) = N_Compilation_Unit then
5372 -- Here we do need to generate an assignment statement
5375 Check_Restriction (No_Elaboration_Code, N);
5377 Make_Assignment_Statement (Loc,
5378 Name => New_Occurrence_Of (Ent, Loc),
5379 Expression => New_Occurrence_Of (Standard_True, Loc));
5381 if Nkind (Parent (N)) = N_Subunit then
5382 Insert_After (Corresponding_Stub (Parent (N)), Asn);
5384 Insert_After (N, Asn);
5389 -- Kill current value indication. This is necessary because the
5390 -- tests of this flag are inserted out of sequence and must not
5391 -- pick up bogus indications of the wrong constant value.
5393 Set_Current_Value (Ent, Empty);
5396 end Set_Elaboration_Flag;
5398 ----------------------------
5399 -- Set_Renamed_Subprogram --
5400 ----------------------------
5402 procedure Set_Renamed_Subprogram (N : Node_Id; E : Entity_Id) is
5404 -- If input node is an identifier, we can just reset it
5406 if Nkind (N) = N_Identifier then
5407 Set_Chars (N, Chars (E));
5410 -- Otherwise we have to do a rewrite, preserving Comes_From_Source
5414 CS : constant Boolean := Comes_From_Source (N);
5416 Rewrite (N, Make_Identifier (Sloc (N), Chars => Chars (E)));
5418 Set_Comes_From_Source (N, CS);
5419 Set_Analyzed (N, True);
5422 end Set_Renamed_Subprogram;
5424 ----------------------------------
5425 -- Silly_Boolean_Array_Not_Test --
5426 ----------------------------------
5428 -- This procedure implements an odd and silly test. We explicitly check
5429 -- for the case where the 'First of the component type is equal to the
5430 -- 'Last of this component type, and if this is the case, we make sure
5431 -- that constraint error is raised. The reason is that the NOT is bound
5432 -- to cause CE in this case, and we will not otherwise catch it.
5434 -- No such check is required for AND and OR, since for both these cases
5435 -- False op False = False, and True op True = True. For the XOR case,
5436 -- see Silly_Boolean_Array_Xor_Test.
5438 -- Believe it or not, this was reported as a bug. Note that nearly
5439 -- always, the test will evaluate statically to False, so the code will
5440 -- be statically removed, and no extra overhead caused.
5442 procedure Silly_Boolean_Array_Not_Test (N : Node_Id; T : Entity_Id) is
5443 Loc : constant Source_Ptr := Sloc (N);
5444 CT : constant Entity_Id := Component_Type (T);
5447 -- The check we install is
5449 -- constraint_error when
5450 -- component_type'first = component_type'last
5451 -- and then array_type'Length /= 0)
5453 -- We need the last guard because we don't want to raise CE for empty
5454 -- arrays since no out of range values result. (Empty arrays with a
5455 -- component type of True .. True -- very useful -- even the ACATS
5456 -- does not test that marginal case!)
5459 Make_Raise_Constraint_Error (Loc,
5465 Make_Attribute_Reference (Loc,
5466 Prefix => New_Occurrence_Of (CT, Loc),
5467 Attribute_Name => Name_First),
5470 Make_Attribute_Reference (Loc,
5471 Prefix => New_Occurrence_Of (CT, Loc),
5472 Attribute_Name => Name_Last)),
5474 Right_Opnd => Make_Non_Empty_Check (Loc, Right_Opnd (N))),
5475 Reason => CE_Range_Check_Failed));
5476 end Silly_Boolean_Array_Not_Test;
5478 ----------------------------------
5479 -- Silly_Boolean_Array_Xor_Test --
5480 ----------------------------------
5482 -- This procedure implements an odd and silly test. We explicitly check
5483 -- for the XOR case where the component type is True .. True, since this
5484 -- will raise constraint error. A special check is required since CE
5485 -- will not be generated otherwise (cf Expand_Packed_Not).
5487 -- No such check is required for AND and OR, since for both these cases
5488 -- False op False = False, and True op True = True, and no check is
5489 -- required for the case of False .. False, since False xor False = False.
5490 -- See also Silly_Boolean_Array_Not_Test
5492 procedure Silly_Boolean_Array_Xor_Test (N : Node_Id; T : Entity_Id) is
5493 Loc : constant Source_Ptr := Sloc (N);
5494 CT : constant Entity_Id := Component_Type (T);
5497 -- The check we install is
5499 -- constraint_error when
5500 -- Boolean (component_type'First)
5501 -- and then Boolean (component_type'Last)
5502 -- and then array_type'Length /= 0)
5504 -- We need the last guard because we don't want to raise CE for empty
5505 -- arrays since no out of range values result (Empty arrays with a
5506 -- component type of True .. True -- very useful -- even the ACATS
5507 -- does not test that marginal case!).
5510 Make_Raise_Constraint_Error (Loc,
5516 Convert_To (Standard_Boolean,
5517 Make_Attribute_Reference (Loc,
5518 Prefix => New_Occurrence_Of (CT, Loc),
5519 Attribute_Name => Name_First)),
5522 Convert_To (Standard_Boolean,
5523 Make_Attribute_Reference (Loc,
5524 Prefix => New_Occurrence_Of (CT, Loc),
5525 Attribute_Name => Name_Last))),
5527 Right_Opnd => Make_Non_Empty_Check (Loc, Right_Opnd (N))),
5528 Reason => CE_Range_Check_Failed));
5529 end Silly_Boolean_Array_Xor_Test;
5531 --------------------------
5532 -- Target_Has_Fixed_Ops --
5533 --------------------------
5535 Integer_Sized_Small : Ureal;
5536 -- Set to 2.0 ** -(Integer'Size - 1) the first time that this
5537 -- function is called (we don't want to compute it more than once!)
5539 Long_Integer_Sized_Small : Ureal;
5540 -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this
5541 -- function is called (we don't want to compute it more than once)
5543 First_Time_For_THFO : Boolean := True;
5544 -- Set to False after first call (if Fractional_Fixed_Ops_On_Target)
5546 function Target_Has_Fixed_Ops
5547 (Left_Typ : Entity_Id;
5548 Right_Typ : Entity_Id;
5549 Result_Typ : Entity_Id) return Boolean
5551 function Is_Fractional_Type (Typ : Entity_Id) return Boolean;
5552 -- Return True if the given type is a fixed-point type with a small
5553 -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have
5554 -- an absolute value less than 1.0. This is currently limited
5555 -- to fixed-point types that map to Integer or Long_Integer.
5557 ------------------------
5558 -- Is_Fractional_Type --
5559 ------------------------
5561 function Is_Fractional_Type (Typ : Entity_Id) return Boolean is
5563 if Esize (Typ) = Standard_Integer_Size then
5564 return Small_Value (Typ) = Integer_Sized_Small;
5566 elsif Esize (Typ) = Standard_Long_Integer_Size then
5567 return Small_Value (Typ) = Long_Integer_Sized_Small;
5572 end Is_Fractional_Type;
5574 -- Start of processing for Target_Has_Fixed_Ops
5577 -- Return False if Fractional_Fixed_Ops_On_Target is false
5579 if not Fractional_Fixed_Ops_On_Target then
5583 -- Here the target has Fractional_Fixed_Ops, if first time, compute
5584 -- standard constants used by Is_Fractional_Type.
5586 if First_Time_For_THFO then
5587 First_Time_For_THFO := False;
5589 Integer_Sized_Small :=
5592 Den => UI_From_Int (Standard_Integer_Size - 1),
5595 Long_Integer_Sized_Small :=
5598 Den => UI_From_Int (Standard_Long_Integer_Size - 1),
5602 -- Return True if target supports fixed-by-fixed multiply/divide
5603 -- for fractional fixed-point types (see Is_Fractional_Type) and
5604 -- the operand and result types are equivalent fractional types.
5606 return Is_Fractional_Type (Base_Type (Left_Typ))
5607 and then Is_Fractional_Type (Base_Type (Right_Typ))
5608 and then Is_Fractional_Type (Base_Type (Result_Typ))
5609 and then Esize (Left_Typ) = Esize (Right_Typ)
5610 and then Esize (Left_Typ) = Esize (Result_Typ);
5611 end Target_Has_Fixed_Ops;
5613 ------------------------------------------
5614 -- Type_May_Have_Bit_Aligned_Components --
5615 ------------------------------------------
5617 function Type_May_Have_Bit_Aligned_Components
5618 (Typ : Entity_Id) return Boolean
5621 -- Array type, check component type
5623 if Is_Array_Type (Typ) then
5625 Type_May_Have_Bit_Aligned_Components (Component_Type (Typ));
5627 -- Record type, check components
5629 elsif Is_Record_Type (Typ) then
5634 E := First_Component_Or_Discriminant (Typ);
5635 while Present (E) loop
5636 if Component_May_Be_Bit_Aligned (E)
5637 or else Type_May_Have_Bit_Aligned_Components (Etype (E))
5642 Next_Component_Or_Discriminant (E);
5648 -- Type other than array or record is always OK
5653 end Type_May_Have_Bit_Aligned_Components;
5655 ----------------------------
5656 -- Wrap_Cleanup_Procedure --
5657 ----------------------------
5659 procedure Wrap_Cleanup_Procedure (N : Node_Id) is
5660 Loc : constant Source_Ptr := Sloc (N);
5661 Stseq : constant Node_Id := Handled_Statement_Sequence (N);
5662 Stmts : constant List_Id := Statements (Stseq);
5665 if Abort_Allowed then
5666 Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
5667 Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));
5669 end Wrap_Cleanup_Procedure;