1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
11 -- Copyright (C) 1992-2001, Free Software Foundation, Inc. --
13 -- GNAT is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNAT; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
24 -- GNAT was originally developed by the GNAT team at New York University. --
25 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
27 ------------------------------------------------------------------------------
29 with Atree; use Atree;
30 with Checks; use Checks;
31 with Einfo; use Einfo;
32 with Elists; use Elists;
33 with Errout; use Errout;
34 with Exp_Ch7; use Exp_Ch7;
35 with Exp_Ch11; use Exp_Ch11;
36 with Hostparm; use Hostparm;
37 with Inline; use Inline;
38 with Itypes; use Itypes;
40 with Namet; use Namet;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Restrict; use Restrict;
46 with Sem_Ch8; use Sem_Ch8;
47 with Sem_Eval; use Sem_Eval;
48 with Sem_Res; use Sem_Res;
49 with Sem_Util; use Sem_Util;
50 with Sinfo; use Sinfo;
51 with Stand; use Stand;
52 with Stringt; use Stringt;
53 with Tbuild; use Tbuild;
54 with Ttypes; use Ttypes;
55 with Uintp; use Uintp;
56 with Validsw; use Validsw;
58 package body Exp_Util is
60 -----------------------
61 -- Local Subprograms --
62 -----------------------
64 function Build_Task_Array_Image
68 Dyn : Boolean := False)
70 -- Build function to generate the image string for a task that is an
71 -- array component, concatenating the images of each index. To avoid
72 -- storage leaks, the string is built with successive slice assignments.
73 -- The flag Dyn indicates whether this is called for the initialization
74 -- procedure of an array of tasks, or for the name of a dynamically
75 -- created task that is assigned to an indexed component.
77 function Build_Task_Image_Function
83 -- Common processing for Task_Array_Image and Task_Record_Image.
84 -- Build function body that computes image.
86 procedure Build_Task_Image_Prefix
93 Decls : in out List_Id;
94 Stats : in out List_Id);
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
102 Dyn : Boolean := False)
104 -- Build function to generate the image string for a task that is a
105 -- record component. Concatenate name of variable with that of selector.
106 -- The flag Dyn indicates whether this is called for the initialization
107 -- procedure of record with task components, or for a dynamically
108 -- created task that is assigned to a selected component.
110 function Make_CW_Equivalent_Type
114 -- T is a class-wide type entity, E is the initial expression node that
115 -- constrains T in case such as: " X: T := E" or "new T'(E)"
116 -- This function returns the entity of the Equivalent type and inserts
117 -- on the fly the necessary declaration such as:
118 -- type anon is record
119 -- _parent : Root_Type (T); constrained with E discriminants (if any)
120 -- Extension : String (1 .. expr to match size of E);
123 -- This record is compatible with any object of the class of T thanks
124 -- to the first field and has the same size as E thanks to the second.
126 function Make_Literal_Range
128 Literal_Typ : Entity_Id)
130 -- Produce a Range node whose bounds are:
131 -- Low_Bound (Literal_Type) ..
132 -- Low_Bound (Literal_Type) + Length (Literal_Typ) - 1
133 -- this is used for expanding declarations like X : String := "sdfgdfg";
135 function New_Class_Wide_Subtype
139 -- Create an implicit subtype of CW_Typ attached to node N.
141 ----------------------
142 -- Adjust_Condition --
143 ----------------------
145 procedure Adjust_Condition (N : Node_Id) is
152 Loc : constant Source_Ptr := Sloc (N);
153 T : constant Entity_Id := Etype (N);
157 -- For now, we simply ignore a call where the argument has no
158 -- type (probably case of unanalyzed condition), or has a type
159 -- that is not Boolean. This is because this is a pretty marginal
160 -- piece of functionality, and violations of these rules are
161 -- likely to be truly marginal (how much code uses Fortran Logical
162 -- as the barrier to a protected entry?) and we do not want to
163 -- blow up existing programs. We can change this to an assertion
164 -- after 3.12a is released ???
166 if No (T) or else not Is_Boolean_Type (T) then
170 -- Apply validity checking if needed
172 if Validity_Checks_On and Validity_Check_Tests then
176 -- Immediate return if standard boolean, the most common case,
177 -- where nothing needs to be done.
179 if Base_Type (T) = Standard_Boolean then
183 -- Case of zero/non-zero semantics or non-standard enumeration
184 -- representation. In each case, we rewrite the node as:
186 -- ityp!(N) /= False'Enum_Rep
188 -- where ityp is an integer type with large enough size to hold
189 -- any value of type T.
191 if Nonzero_Is_True (T) or else Has_Non_Standard_Rep (T) then
192 if Esize (T) <= Esize (Standard_Integer) then
193 Ti := Standard_Integer;
195 Ti := Standard_Long_Long_Integer;
200 Left_Opnd => Unchecked_Convert_To (Ti, N),
202 Make_Attribute_Reference (Loc,
203 Attribute_Name => Name_Enum_Rep,
205 New_Occurrence_Of (First_Literal (T), Loc))));
206 Analyze_And_Resolve (N, Standard_Boolean);
209 Rewrite (N, Convert_To (Standard_Boolean, N));
210 Analyze_And_Resolve (N, Standard_Boolean);
213 end Adjust_Condition;
215 ------------------------
216 -- Adjust_Result_Type --
217 ------------------------
219 procedure Adjust_Result_Type (N : Node_Id; T : Entity_Id) is
221 -- Ignore call if current type is not Standard.Boolean
223 if Etype (N) /= Standard_Boolean then
227 -- If result is already of correct type, nothing to do. Note that
228 -- this will get the most common case where everything has a type
229 -- of Standard.Boolean.
231 if Base_Type (T) = Standard_Boolean then
236 KP : constant Node_Kind := Nkind (Parent (N));
239 -- If result is to be used as a Condition in the syntax, no need
240 -- to convert it back, since if it was changed to Standard.Boolean
241 -- using Adjust_Condition, that is just fine for this usage.
243 if KP in N_Raise_xxx_Error or else KP in N_Has_Condition then
246 -- If result is an operand of another logical operation, no need
247 -- to reset its type, since Standard.Boolean is just fine, and
248 -- such operations always do Adjust_Condition on their operands.
250 elsif KP in N_Op_Boolean
251 or else KP = N_And_Then
252 or else KP = N_Or_Else
253 or else KP = N_Op_Not
257 -- Otherwise we perform a conversion from the current type,
258 -- which must be Standard.Boolean, to the desired type.
262 Rewrite (N, Convert_To (T, N));
263 Analyze_And_Resolve (N, T);
267 end Adjust_Result_Type;
269 --------------------------
270 -- Append_Freeze_Action --
271 --------------------------
273 procedure Append_Freeze_Action (T : Entity_Id; N : Node_Id) is
274 Fnode : Node_Id := Freeze_Node (T);
277 Ensure_Freeze_Node (T);
278 Fnode := Freeze_Node (T);
280 if not Present (Actions (Fnode)) then
281 Set_Actions (Fnode, New_List);
284 Append (N, Actions (Fnode));
285 end Append_Freeze_Action;
287 ---------------------------
288 -- Append_Freeze_Actions --
289 ---------------------------
291 procedure Append_Freeze_Actions (T : Entity_Id; L : List_Id) is
292 Fnode : constant Node_Id := Freeze_Node (T);
299 if No (Actions (Fnode)) then
300 Set_Actions (Fnode, L);
303 Append_List (L, Actions (Fnode));
307 end Append_Freeze_Actions;
309 ------------------------
310 -- Build_Runtime_Call --
311 ------------------------
313 function Build_Runtime_Call (Loc : Source_Ptr; RE : RE_Id) return Node_Id is
316 Make_Procedure_Call_Statement (Loc,
317 Name => New_Reference_To (RTE (RE), Loc));
318 end Build_Runtime_Call;
320 -----------------------------
321 -- Build_Task_Array_Image --
322 -----------------------------
324 -- This function generates the body for a function that constructs the
325 -- image string for a task that is an array component. The function is
326 -- local to the init_proc for the array type, and is called for each one
327 -- of the components. The constructed image has the form of an indexed
328 -- component, whose prefix is the outer variable of the array type.
329 -- The n-dimensional array type has known indices Index, Index2...
330 -- Id_Ref is an indexed component form created by the enclosing init_proc.
331 -- Its successive indices are Val1, Val2,.. which are the loop variables
332 -- in the loops that call the individual task init_proc on each component.
334 -- The generated function has the following structure:
336 -- function F return Task_Image_Type is
337 -- Pref : string := Task_Id.all;
338 -- T1 : String := Index1'Image (Val1);
340 -- Tn : String := indexn'image (Valn);
341 -- Len : Integer := T1'Length + ... + Tn'Length + n + 1;
342 -- -- Len includes commas and the end parentheses.
343 -- Res : String (1..Len);
344 -- Pos : Integer := Pref'Length;
347 -- Res (1 .. Pos) := Pref;
351 -- Res (Pos .. Pos + T1'Length - 1) := T1;
352 -- Pos := Pos + T1'Length;
356 -- Res (Pos .. Pos + Tn'Length - 1) := Tn;
359 -- return new String (Res);
362 -- Needless to say, multidimensional arrays of tasks are rare enough
363 -- that the bulkiness of this code is not really a concern.
365 function Build_Task_Array_Image
369 Dyn : Boolean := False)
372 Dims : constant Nat := Number_Dimensions (A_Type);
373 -- Number of dimensions for array of tasks.
375 Temps : array (1 .. Dims) of Entity_Id;
376 -- Array of temporaries to hold string for each index.
382 -- Total length of generated name
385 -- Running index for substring assignments
388 -- Name of enclosing variable, prefix of resulting name
391 -- string expression for Pref.
394 -- String to hold result
397 -- Value of successive indices
400 -- Expression to compute total size of string
403 -- Entity for name at one index position
405 Decls : List_Id := New_List;
406 Stats : List_Id := New_List;
409 Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
411 -- For a dynamic task, the name comes from the target variable.
412 -- For a static one it is a formal of the enclosing init_proc.
415 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
417 Make_String_Literal (Loc, Strval => String_From_Name_Buffer);
420 Make_Explicit_Dereference (Loc,
421 Prefix => Make_Identifier (Loc, Name_uTask_Id));
425 Make_Object_Declaration (Loc,
426 Defining_Identifier => Pref,
427 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
428 Expression => P_Nam));
430 Indx := First_Index (A_Type);
431 Val := First (Expressions (Id_Ref));
433 for J in 1 .. Dims loop
434 T := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
438 Make_Object_Declaration (Loc,
439 Defining_Identifier => T,
440 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
442 Make_Attribute_Reference (Loc,
443 Attribute_Name => Name_Image,
445 New_Occurrence_Of (Etype (Indx), Loc),
446 Expressions => New_List (
447 New_Copy_Tree (Val)))));
453 Sum := Make_Integer_Literal (Loc, Dims + 1);
459 Make_Attribute_Reference (Loc,
460 Attribute_Name => Name_Length,
462 New_Occurrence_Of (Pref, Loc),
463 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
465 for J in 1 .. Dims loop
470 Make_Attribute_Reference (Loc,
471 Attribute_Name => Name_Length,
473 New_Occurrence_Of (Temps (J), Loc),
474 Expressions => New_List (Make_Integer_Literal (Loc, 1))));
477 Build_Task_Image_Prefix (Loc, Len, Res, Pos, Pref, Sum, Decls, Stats);
479 Set_Character_Literal_Name (Char_Code (Character'Pos ('(')));
482 Make_Assignment_Statement (Loc,
483 Name => Make_Indexed_Component (Loc,
484 Prefix => New_Occurrence_Of (Res, Loc),
485 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
487 Make_Character_Literal (Loc,
489 Char_Literal_Value =>
490 Char_Code (Character'Pos ('(')))));
493 Make_Assignment_Statement (Loc,
494 Name => New_Occurrence_Of (Pos, Loc),
497 Left_Opnd => New_Occurrence_Of (Pos, Loc),
498 Right_Opnd => Make_Integer_Literal (Loc, 1))));
500 for J in 1 .. Dims loop
503 Make_Assignment_Statement (Loc,
504 Name => Make_Slice (Loc,
505 Prefix => New_Occurrence_Of (Res, Loc),
508 Low_Bound => New_Occurrence_Of (Pos, Loc),
509 High_Bound => Make_Op_Subtract (Loc,
512 Left_Opnd => New_Occurrence_Of (Pos, Loc),
514 Make_Attribute_Reference (Loc,
515 Attribute_Name => Name_Length,
517 New_Occurrence_Of (Temps (J), Loc),
519 New_List (Make_Integer_Literal (Loc, 1)))),
520 Right_Opnd => Make_Integer_Literal (Loc, 1)))),
522 Expression => New_Occurrence_Of (Temps (J), Loc)));
526 Make_Assignment_Statement (Loc,
527 Name => New_Occurrence_Of (Pos, Loc),
530 Left_Opnd => New_Occurrence_Of (Pos, Loc),
532 Make_Attribute_Reference (Loc,
533 Attribute_Name => Name_Length,
534 Prefix => New_Occurrence_Of (Temps (J), Loc),
536 New_List (Make_Integer_Literal (Loc, 1))))));
538 Set_Character_Literal_Name (Char_Code (Character'Pos (',')));
541 Make_Assignment_Statement (Loc,
542 Name => Make_Indexed_Component (Loc,
543 Prefix => New_Occurrence_Of (Res, Loc),
544 Expressions => New_List (New_Occurrence_Of (Pos, Loc))),
546 Make_Character_Literal (Loc,
548 Char_Literal_Value =>
549 Char_Code (Character'Pos (',')))));
552 Make_Assignment_Statement (Loc,
553 Name => New_Occurrence_Of (Pos, Loc),
556 Left_Opnd => New_Occurrence_Of (Pos, Loc),
557 Right_Opnd => Make_Integer_Literal (Loc, 1))));
561 Set_Character_Literal_Name (Char_Code (Character'Pos (')')));
564 Make_Assignment_Statement (Loc,
565 Name => Make_Indexed_Component (Loc,
566 Prefix => New_Occurrence_Of (Res, Loc),
567 Expressions => New_List (New_Occurrence_Of (Len, Loc))),
569 Make_Character_Literal (Loc,
571 Char_Literal_Value =>
572 Char_Code (Character'Pos (')')))));
573 return Build_Task_Image_Function (Loc, Decls, Stats, Res);
574 end Build_Task_Array_Image;
576 ----------------------------
577 -- Build_Task_Image_Decls --
578 ----------------------------
580 function Build_Task_Image_Decls
586 T_Id : Entity_Id := Empty;
588 Decls : List_Id := New_List;
589 Expr : Node_Id := Empty;
590 Fun : Node_Id := Empty;
591 Is_Dyn : constant Boolean :=
592 Nkind (Parent (Id_Ref)) = N_Assignment_Statement
593 and then Nkind (Expression (Parent (Id_Ref))) = N_Allocator;
596 -- If Discard_Names is in effect, generate a dummy declaration only.
598 if Global_Discard_Names then
600 Make_Defining_Identifier (Loc, New_Internal_Name ('I'));
604 Make_Object_Declaration (Loc,
605 Defining_Identifier => T_Id,
607 New_Occurrence_Of (RTE (RE_Task_Image_Type), Loc)));
610 if Nkind (Id_Ref) = N_Identifier
611 or else Nkind (Id_Ref) = N_Defining_Identifier
613 -- For a simple variable, the image of the task is the name
617 Make_Defining_Identifier (Loc,
618 New_External_Name (Chars (Id_Ref), 'I'));
620 Get_Name_String (Chars (Id_Ref));
625 Make_Qualified_Expression (Loc,
627 New_Occurrence_Of (Standard_String, Loc),
630 (Loc, Strval => String_From_Name_Buffer)));
632 elsif Nkind (Id_Ref) = N_Selected_Component then
634 Make_Defining_Identifier (Loc,
635 New_External_Name (Chars (Selector_Name (Id_Ref)), 'I'));
636 Fun := Build_Task_Record_Image (Loc, Id_Ref, A_Type, Is_Dyn);
638 elsif Nkind (Id_Ref) = N_Indexed_Component then
640 Make_Defining_Identifier (Loc,
641 New_External_Name (Chars (A_Type), 'I'));
643 Fun := Build_Task_Array_Image (Loc, Id_Ref, A_Type, Is_Dyn);
647 if Present (Fun) then
651 Make_Function_Call (Loc,
652 Name => New_Occurrence_Of (Defining_Entity (Fun), Loc));
655 Decl := Make_Object_Declaration (Loc,
656 Defining_Identifier => T_Id,
658 New_Occurrence_Of (RTE (RE_Task_Image_Type), Loc),
661 Append (Decl, Decls);
663 end Build_Task_Image_Decls;
665 -------------------------------
666 -- Build_Task_Image_Function --
667 -------------------------------
669 function Build_Task_Image_Function
680 Make_Return_Statement (Loc,
684 Make_Qualified_Expression (Loc,
686 New_Occurrence_Of (Standard_String, Loc),
687 Expression => New_Occurrence_Of (Res, Loc)))));
689 Spec := Make_Function_Specification (Loc,
690 Defining_Unit_Name =>
691 Make_Defining_Identifier (Loc, New_Internal_Name ('F')),
692 Subtype_Mark => New_Occurrence_Of (RTE (RE_Task_Image_Type), Loc));
694 return Make_Subprogram_Body (Loc,
695 Specification => Spec,
696 Declarations => Decls,
697 Handled_Statement_Sequence =>
698 Make_Handled_Sequence_Of_Statements (Loc,
699 Statements => Stats));
700 end Build_Task_Image_Function;
702 -----------------------------
703 -- Build_Task_Image_Prefix --
704 -----------------------------
706 procedure Build_Task_Image_Prefix
713 Decls : in out List_Id;
714 Stats : in out List_Id)
717 Len := Make_Defining_Identifier (Loc, New_Internal_Name ('L'));
720 Make_Object_Declaration (Loc,
721 Defining_Identifier => Len,
722 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc),
725 Res := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
728 Make_Object_Declaration (Loc,
729 Defining_Identifier => Res,
731 Make_Subtype_Indication (Loc,
732 Subtype_Mark => New_Occurrence_Of (Standard_String, Loc),
734 Make_Index_Or_Discriminant_Constraint (Loc,
738 Low_Bound => Make_Integer_Literal (Loc, 1),
739 High_Bound => New_Occurrence_Of (Len, Loc)))))));
741 Pos := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
744 Make_Object_Declaration (Loc,
745 Defining_Identifier => Pos,
746 Object_Definition => New_Occurrence_Of (Standard_Integer, Loc)));
748 -- Pos := Prefix'Length;
751 Make_Assignment_Statement (Loc,
752 Name => New_Occurrence_Of (Pos, Loc),
754 Make_Attribute_Reference (Loc,
755 Attribute_Name => Name_Length,
756 Prefix => New_Occurrence_Of (Prefix, Loc),
758 New_List (Make_Integer_Literal (Loc, 1)))));
760 -- Res (1 .. Pos) := Prefix;
763 Make_Assignment_Statement (Loc,
764 Name => Make_Slice (Loc,
765 Prefix => New_Occurrence_Of (Res, Loc),
768 Low_Bound => Make_Integer_Literal (Loc, 1),
769 High_Bound => New_Occurrence_Of (Pos, Loc))),
771 Expression => New_Occurrence_Of (Prefix, Loc)));
774 Make_Assignment_Statement (Loc,
775 Name => New_Occurrence_Of (Pos, Loc),
778 Left_Opnd => New_Occurrence_Of (Pos, Loc),
779 Right_Opnd => Make_Integer_Literal (Loc, 1))));
780 end Build_Task_Image_Prefix;
782 -----------------------------
783 -- Build_Task_Record_Image --
784 -----------------------------
786 function Build_Task_Record_Image
790 Dyn : Boolean := False)
794 -- Total length of generated name
800 -- String to hold result
803 -- Name of enclosing variable, prefix of resulting name
806 -- string expression for Pref.
809 -- Expression to compute total size of string.
812 -- Entity for selector name
814 Decls : List_Id := New_List;
815 Stats : List_Id := New_List;
818 Pref := Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
820 -- For a dynamic task, the name comes from the target variable.
821 -- For a static one it is a formal of the enclosing init_proc.
824 Get_Name_String (Chars (Entity (Prefix (Id_Ref))));
826 Make_String_Literal (Loc, Strval => String_From_Name_Buffer);
829 Make_Explicit_Dereference (Loc,
830 Prefix => Make_Identifier (Loc, Name_uTask_Id));
834 Make_Object_Declaration (Loc,
835 Defining_Identifier => Pref,
836 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
837 Expression => P_Nam));
839 Sel := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
841 Get_Name_String (Chars (Selector_Name (Id_Ref)));
844 Make_Object_Declaration (Loc,
845 Defining_Identifier => Sel,
846 Object_Definition => New_Occurrence_Of (Standard_String, Loc),
848 Make_String_Literal (Loc, 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 Char_Code (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 -- Convert_To_Actual_Subtype --
904 -------------------------------
906 procedure Convert_To_Actual_Subtype (Exp : Entity_Id) is
910 Act_ST := Get_Actual_Subtype (Exp);
912 if Act_ST = Etype (Exp) then
917 Convert_To (Act_ST, Relocate_Node (Exp)));
918 Analyze_And_Resolve (Exp, Act_ST);
920 end Convert_To_Actual_Subtype;
922 -----------------------------------
923 -- Current_Sem_Unit_Declarations --
924 -----------------------------------
926 function Current_Sem_Unit_Declarations return List_Id is
927 U : Node_Id := Unit (Cunit (Current_Sem_Unit));
931 -- If the current unit is a package body, locate the visible
932 -- declarations of the package spec.
934 if Nkind (U) = N_Package_Body then
935 U := Unit (Library_Unit (Cunit (Current_Sem_Unit)));
938 if Nkind (U) = N_Package_Declaration then
939 U := Specification (U);
940 Decls := Visible_Declarations (U);
944 Set_Visible_Declarations (U, Decls);
948 Decls := Declarations (U);
952 Set_Declarations (U, Decls);
957 end Current_Sem_Unit_Declarations;
959 -----------------------
960 -- Duplicate_Subexpr --
961 -----------------------
963 function Duplicate_Subexpr
965 Name_Req : Boolean := False)
969 Remove_Side_Effects (Exp, Name_Req);
970 return New_Copy_Tree (Exp);
971 end Duplicate_Subexpr;
977 procedure Ensure_Defined (Typ : Entity_Id; N : Node_Id) is
982 if Is_Itype (Typ) then
983 IR := Make_Itype_Reference (Sloc (N));
986 if not In_Open_Scopes (Scope (Typ))
987 and then Is_Subprogram (Current_Scope)
988 and then Scope (Current_Scope) /= Standard_Standard
990 -- Insert node in front of subprogram, to avoid scope anomalies
996 and then Nkind (P) /= N_Subprogram_Body
1002 Insert_Action (P, IR);
1004 Insert_Action (N, IR);
1008 Insert_Action (N, IR);
1013 ---------------------
1014 -- Evolve_And_Then --
1015 ---------------------
1017 procedure Evolve_And_Then (Cond : in out Node_Id; Cond1 : Node_Id) is
1023 Make_And_Then (Sloc (Cond1),
1025 Right_Opnd => Cond1);
1027 end Evolve_And_Then;
1029 --------------------
1030 -- Evolve_Or_Else --
1031 --------------------
1033 procedure Evolve_Or_Else (Cond : in out Node_Id; Cond1 : Node_Id) is
1039 Make_Or_Else (Sloc (Cond1),
1041 Right_Opnd => Cond1);
1045 ------------------------------
1046 -- Expand_Subtype_From_Expr --
1047 ------------------------------
1049 -- This function is applicable for both static and dynamic allocation of
1050 -- objects which are constrained by an initial expression. Basically it
1051 -- transforms an unconstrained subtype indication into a constrained one.
1052 -- The expression may also be transformed in certain cases in order to
1053 -- avoid multiple evaulation. In the static allocation case, the general
1058 -- is transformed into
1060 -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr;
1062 -- Here are the main cases :
1064 -- <if Expr is a Slice>
1065 -- Val : T ([Index_Subtype (Expr)]) := Expr;
1067 -- <elsif Expr is a String Literal>
1068 -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
1070 -- <elsif Expr is Constrained>
1071 -- subtype T is Type_Of_Expr
1074 -- <elsif Expr is an entity_name>
1075 -- Val : T (constraints taken from Expr) := Expr;
1078 -- type Axxx is access all T;
1079 -- Rval : Axxx := Expr'ref;
1080 -- Val : T (constraints taken from Rval) := Rval.all;
1082 -- ??? note: when the Expression is allocated in the secondary stack
1083 -- we could use it directly instead of copying it by declaring
1084 -- Val : T (...) renames Rval.all
1086 procedure Expand_Subtype_From_Expr
1088 Unc_Type : Entity_Id;
1089 Subtype_Indic : Node_Id;
1092 Loc : constant Source_Ptr := Sloc (N);
1093 Exp_Typ : constant Entity_Id := Etype (Exp);
1097 -- In general we cannot build the subtype if expansion is disabled,
1098 -- because internal entities may not have been defined. However, to
1099 -- avoid some cascaded errors, we try to continue when the expression
1100 -- is an array (or string), because it is safe to compute the bounds.
1101 -- It is in fact required to do so even in a generic context, because
1102 -- there may be constants that depend on bounds of string literal.
1104 if not Expander_Active
1105 and then (No (Etype (Exp))
1106 or else Base_Type (Etype (Exp)) /= Standard_String)
1111 if Nkind (Exp) = N_Slice then
1113 Slice_Type : constant Entity_Id := Etype (First_Index (Exp_Typ));
1116 Rewrite (Subtype_Indic,
1117 Make_Subtype_Indication (Loc,
1118 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1120 Make_Index_Or_Discriminant_Constraint (Loc,
1121 Constraints => New_List
1122 (New_Reference_To (Slice_Type, Loc)))));
1124 -- This subtype indication may be used later for contraint checks
1125 -- we better make sure that if a variable was used as a bound of
1126 -- of the original slice, its value is frozen.
1128 Force_Evaluation (Low_Bound (Scalar_Range (Slice_Type)));
1129 Force_Evaluation (High_Bound (Scalar_Range (Slice_Type)));
1132 elsif Ekind (Exp_Typ) = E_String_Literal_Subtype then
1133 Rewrite (Subtype_Indic,
1134 Make_Subtype_Indication (Loc,
1135 Subtype_Mark => New_Reference_To (Unc_Type, Loc),
1137 Make_Index_Or_Discriminant_Constraint (Loc,
1138 Constraints => New_List (
1139 Make_Literal_Range (Loc,
1140 Literal_Typ => Exp_Typ)))));
1142 elsif Is_Constrained (Exp_Typ)
1143 and then not Is_Class_Wide_Type (Unc_Type)
1145 if Is_Itype (Exp_Typ) then
1147 -- No need to generate a new one.
1153 Make_Defining_Identifier (Loc,
1154 Chars => New_Internal_Name ('T'));
1157 Make_Subtype_Declaration (Loc,
1158 Defining_Identifier => T,
1159 Subtype_Indication => New_Reference_To (Exp_Typ, Loc)));
1161 -- This type is marked as an itype even though it has an
1162 -- explicit declaration because otherwise it can be marked
1163 -- with Is_Generic_Actual_Type and generate spurious errors.
1164 -- (see sem_ch8.Analyze_Package_Renaming and sem_type.covers)
1167 Set_Associated_Node_For_Itype (T, Exp);
1170 Rewrite (Subtype_Indic, New_Reference_To (T, Loc));
1172 -- nothing needs to be done for private types with unknown discriminants
1173 -- if the underlying type is not an unconstrained composite type.
1175 elsif Is_Private_Type (Unc_Type)
1176 and then Has_Unknown_Discriminants (Unc_Type)
1177 and then (not Is_Composite_Type (Underlying_Type (Unc_Type))
1178 or else Is_Constrained (Underlying_Type (Unc_Type)))
1183 Remove_Side_Effects (Exp);
1184 Rewrite (Subtype_Indic,
1185 Make_Subtype_From_Expr (Exp, Unc_Type));
1187 end Expand_Subtype_From_Expr;
1193 function Find_Prim_Op (T : Entity_Id; Name : Name_Id) return Entity_Id is
1195 Typ : Entity_Id := T;
1198 if Is_Class_Wide_Type (Typ) then
1199 Typ := Root_Type (Typ);
1202 Typ := Underlying_Type (Typ);
1204 Prim := First_Elmt (Primitive_Operations (Typ));
1205 while Chars (Node (Prim)) /= Name loop
1207 pragma Assert (Present (Prim));
1213 ----------------------
1214 -- Force_Evaluation --
1215 ----------------------
1217 procedure Force_Evaluation (Exp : Node_Id; Name_Req : Boolean := False) is
1219 Remove_Side_Effects (Exp, Name_Req, Variable_Ref => True);
1220 end Force_Evaluation;
1222 ------------------------
1223 -- Generate_Poll_Call --
1224 ------------------------
1226 procedure Generate_Poll_Call (N : Node_Id) is
1228 -- No poll call if polling not active
1230 if not Polling_Required then
1233 -- Otherwise generate require poll call
1236 Insert_Before_And_Analyze (N,
1237 Make_Procedure_Call_Statement (Sloc (N),
1238 Name => New_Occurrence_Of (RTE (RE_Poll), Sloc (N))));
1240 end Generate_Poll_Call;
1242 --------------------
1243 -- Homonym_Number --
1244 --------------------
1246 function Homonym_Number (Subp : Entity_Id) return Nat is
1252 Hom := Homonym (Subp);
1253 while Present (Hom) loop
1254 if Scope (Hom) = Scope (Subp) then
1258 Hom := Homonym (Hom);
1264 ------------------------------
1265 -- In_Unconditional_Context --
1266 ------------------------------
1268 function In_Unconditional_Context (Node : Node_Id) return Boolean is
1273 while Present (P) loop
1275 when N_Subprogram_Body =>
1278 when N_If_Statement =>
1281 when N_Loop_Statement =>
1284 when N_Case_Statement =>
1293 end In_Unconditional_Context;
1299 procedure Insert_Action (Assoc_Node : Node_Id; Ins_Action : Node_Id) is
1301 if Present (Ins_Action) then
1302 Insert_Actions (Assoc_Node, New_List (Ins_Action));
1306 -- Version with check(s) suppressed
1308 procedure Insert_Action
1309 (Assoc_Node : Node_Id; Ins_Action : Node_Id; Suppress : Check_Id)
1312 Insert_Actions (Assoc_Node, New_List (Ins_Action), Suppress);
1315 --------------------
1316 -- Insert_Actions --
1317 --------------------
1319 procedure Insert_Actions (Assoc_Node : Node_Id; Ins_Actions : List_Id) is
1323 Wrapped_Node : Node_Id := Empty;
1326 if No (Ins_Actions) or else Is_Empty_List (Ins_Actions) then
1330 -- Ignore insert of actions from inside default expression in the
1331 -- special preliminary analyze mode. Any insertions at this point
1332 -- have no relevance, since we are only doing the analyze to freeze
1333 -- the types of any static expressions. See section "Handling of
1334 -- Default Expressions" in the spec of package Sem for further details.
1336 if In_Default_Expression then
1340 -- If the action derives from stuff inside a record, then the actions
1341 -- are attached to the current scope, to be inserted and analyzed on
1342 -- exit from the scope. The reason for this is that we may also
1343 -- be generating freeze actions at the same time, and they must
1344 -- eventually be elaborated in the correct order.
1346 if Is_Record_Type (Current_Scope)
1347 and then not Is_Frozen (Current_Scope)
1349 if No (Scope_Stack.Table
1350 (Scope_Stack.Last).Pending_Freeze_Actions)
1352 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions :=
1357 Scope_Stack.Table (Scope_Stack.Last).Pending_Freeze_Actions);
1363 -- We now intend to climb up the tree to find the right point to
1364 -- insert the actions. We start at Assoc_Node, unless this node is
1365 -- a subexpression in which case we start with its parent. We do this
1366 -- for two reasons. First it speeds things up. Second, if Assoc_Node
1367 -- is itself one of the special nodes like N_And_Then, then we assume
1368 -- that an initial request to insert actions for such a node does not
1369 -- expect the actions to get deposited in the node for later handling
1370 -- when the node is expanded, since clearly the node is being dealt
1371 -- with by the caller. Note that in the subexpression case, N is
1372 -- always the child we came from.
1374 -- N_Raise_xxx_Error is an annoying special case, it is a statement
1375 -- if it has type Standard_Void_Type, and a subexpression otherwise.
1376 -- otherwise. Procedure attribute references are also statements.
1378 if Nkind (Assoc_Node) in N_Subexpr
1379 and then (Nkind (Assoc_Node) in N_Raise_xxx_Error
1380 or else Etype (Assoc_Node) /= Standard_Void_Type)
1381 and then (Nkind (Assoc_Node) /= N_Attribute_Reference
1383 not Is_Procedure_Attribute_Name
1384 (Attribute_Name (Assoc_Node)))
1386 P := Assoc_Node; -- ????? does not agree with above!
1387 N := Parent (Assoc_Node);
1389 -- Non-subexpression case. Note that N is initially Empty in this
1390 -- case (N is only guaranteed Non-Empty in the subexpr case).
1397 -- Capture root of the transient scope
1399 if Scope_Is_Transient then
1400 Wrapped_Node := Node_To_Be_Wrapped;
1404 pragma Assert (Present (P));
1408 -- Case of right operand of AND THEN or OR ELSE. Put the actions
1409 -- in the Actions field of the right operand. They will be moved
1410 -- out further when the AND THEN or OR ELSE operator is expanded.
1411 -- Nothing special needs to be done for the left operand since
1412 -- in that case the actions are executed unconditionally.
1414 when N_And_Then | N_Or_Else =>
1415 if N = Right_Opnd (P) then
1416 if Present (Actions (P)) then
1417 Insert_List_After_And_Analyze
1418 (Last (Actions (P)), Ins_Actions);
1420 Set_Actions (P, Ins_Actions);
1421 Analyze_List (Actions (P));
1427 -- Then or Else operand of conditional expression. Add actions to
1428 -- Then_Actions or Else_Actions field as appropriate. The actions
1429 -- will be moved further out when the conditional is expanded.
1431 when N_Conditional_Expression =>
1433 ThenX : constant Node_Id := Next (First (Expressions (P)));
1434 ElseX : constant Node_Id := Next (ThenX);
1437 -- Actions belong to the then expression, temporarily
1438 -- place them as Then_Actions of the conditional expr.
1439 -- They will be moved to the proper place later when
1440 -- the conditional expression is expanded.
1443 if Present (Then_Actions (P)) then
1444 Insert_List_After_And_Analyze
1445 (Last (Then_Actions (P)), Ins_Actions);
1447 Set_Then_Actions (P, Ins_Actions);
1448 Analyze_List (Then_Actions (P));
1453 -- Actions belong to the else expression, temporarily
1454 -- place them as Else_Actions of the conditional expr.
1455 -- They will be moved to the proper place later when
1456 -- the conditional expression is expanded.
1458 elsif N = ElseX then
1459 if Present (Else_Actions (P)) then
1460 Insert_List_After_And_Analyze
1461 (Last (Else_Actions (P)), Ins_Actions);
1463 Set_Else_Actions (P, Ins_Actions);
1464 Analyze_List (Else_Actions (P));
1469 -- Actions belong to the condition. In this case they are
1470 -- unconditionally executed, and so we can continue the
1471 -- search for the proper insert point.
1478 -- Case of appearing in the condition of a while expression or
1479 -- elsif. We insert the actions into the Condition_Actions field.
1480 -- They will be moved further out when the while loop or elsif
1483 when N_Iteration_Scheme |
1486 if N = Condition (P) then
1487 if Present (Condition_Actions (P)) then
1488 Insert_List_After_And_Analyze
1489 (Last (Condition_Actions (P)), Ins_Actions);
1491 Set_Condition_Actions (P, Ins_Actions);
1493 -- Set the parent of the insert actions explicitly.
1494 -- This is not a syntactic field, but we need the
1495 -- parent field set, in particular so that freeze
1496 -- can understand that it is dealing with condition
1497 -- actions, and properly insert the freezing actions.
1499 Set_Parent (Ins_Actions, P);
1500 Analyze_List (Condition_Actions (P));
1506 -- Statements, declarations, pragmas, representation clauses.
1511 N_Procedure_Call_Statement |
1512 N_Statement_Other_Than_Procedure_Call |
1518 -- Representation_Clause
1521 N_Attribute_Definition_Clause |
1522 N_Enumeration_Representation_Clause |
1523 N_Record_Representation_Clause |
1527 N_Abstract_Subprogram_Declaration |
1529 N_Exception_Declaration |
1530 N_Exception_Renaming_Declaration |
1531 N_Formal_Object_Declaration |
1532 N_Formal_Subprogram_Declaration |
1533 N_Formal_Type_Declaration |
1534 N_Full_Type_Declaration |
1535 N_Function_Instantiation |
1536 N_Generic_Function_Renaming_Declaration |
1537 N_Generic_Package_Declaration |
1538 N_Generic_Package_Renaming_Declaration |
1539 N_Generic_Procedure_Renaming_Declaration |
1540 N_Generic_Subprogram_Declaration |
1541 N_Implicit_Label_Declaration |
1542 N_Incomplete_Type_Declaration |
1543 N_Number_Declaration |
1544 N_Object_Declaration |
1545 N_Object_Renaming_Declaration |
1547 N_Package_Body_Stub |
1548 N_Package_Declaration |
1549 N_Package_Instantiation |
1550 N_Package_Renaming_Declaration |
1551 N_Private_Extension_Declaration |
1552 N_Private_Type_Declaration |
1553 N_Procedure_Instantiation |
1554 N_Protected_Body_Stub |
1555 N_Protected_Type_Declaration |
1556 N_Single_Task_Declaration |
1558 N_Subprogram_Body_Stub |
1559 N_Subprogram_Declaration |
1560 N_Subprogram_Renaming_Declaration |
1561 N_Subtype_Declaration |
1564 N_Task_Type_Declaration |
1566 -- Freeze entity behaves like a declaration or statement
1570 -- Do not insert here if the item is not a list member (this
1571 -- happens for example with a triggering statement, and the
1572 -- proper approach is to insert before the entire select).
1574 if not Is_List_Member (P) then
1577 -- Do not insert if parent of P is an N_Component_Association
1578 -- node (i.e. we are in the context of an N_Aggregate node.
1579 -- In this case we want to insert before the entire aggregate.
1581 elsif Nkind (Parent (P)) = N_Component_Association then
1584 -- Do not insert if the parent of P is either an N_Variant
1585 -- node or an N_Record_Definition node, meaning in either
1586 -- case that P is a member of a component list, and that
1587 -- therefore the actions should be inserted outside the
1588 -- complete record declaration.
1590 elsif Nkind (Parent (P)) = N_Variant
1591 or else Nkind (Parent (P)) = N_Record_Definition
1595 -- Do not insert freeze nodes within the loop generated for
1596 -- an aggregate, because they may be elaborated too late for
1597 -- subsequent use in the back end: within a package spec the
1598 -- loop is part of the elaboration procedure and is only
1599 -- elaborated during the second pass.
1600 -- If the loop comes from source, or the entity is local to
1601 -- the loop itself it must remain within.
1603 elsif Nkind (Parent (P)) = N_Loop_Statement
1604 and then not Comes_From_Source (Parent (P))
1605 and then Nkind (First (Ins_Actions)) = N_Freeze_Entity
1607 Scope (Entity (First (Ins_Actions))) /= Current_Scope
1611 -- Otherwise we can go ahead and do the insertion
1613 elsif P = Wrapped_Node then
1614 Store_Before_Actions_In_Scope (Ins_Actions);
1618 Insert_List_Before_And_Analyze (P, Ins_Actions);
1622 -- A special case, N_Raise_xxx_Error can act either as a
1623 -- statement or a subexpression. We tell the difference
1624 -- by looking at the Etype. It is set to Standard_Void_Type
1625 -- in the statement case.
1628 N_Raise_xxx_Error =>
1629 if Etype (P) = Standard_Void_Type then
1630 if P = Wrapped_Node then
1631 Store_Before_Actions_In_Scope (Ins_Actions);
1633 Insert_List_Before_And_Analyze (P, Ins_Actions);
1638 -- In the subexpression case, keep climbing
1644 -- If a component association appears within a loop created for
1645 -- an array aggregate, attach the actions to the association so
1646 -- they can be subsequently inserted within the loop. For other
1647 -- component associations insert outside of the aggregate.
1649 -- The list of loop_actions can in turn generate additional ones,
1650 -- that are inserted before the associated node. If the associated
1651 -- node is outside the aggregate, the new actions are collected
1652 -- at the end of the loop actions, to respect the order in which
1653 -- they are to be elaborated.
1656 N_Component_Association =>
1657 if Nkind (Parent (P)) = N_Aggregate
1658 and then Present (Aggregate_Bounds (Parent (P)))
1659 and then Nkind (First (Choices (P))) = N_Others_Choice
1660 and then Nkind (First (Ins_Actions)) /= N_Freeze_Entity
1662 if No (Loop_Actions (P)) then
1663 Set_Loop_Actions (P, Ins_Actions);
1664 Analyze_List (Ins_Actions);
1668 Decl : Node_Id := Assoc_Node;
1671 -- Check whether these actions were generated
1672 -- by a declaration that is part of the loop_
1673 -- actions for the component_association.
1675 while Present (Decl) loop
1676 exit when Parent (Decl) = P
1677 and then Is_List_Member (Decl)
1679 List_Containing (Decl) = Loop_Actions (P);
1680 Decl := Parent (Decl);
1683 if Present (Decl) then
1684 Insert_List_Before_And_Analyze
1685 (Decl, Ins_Actions);
1687 Insert_List_After_And_Analyze
1688 (Last (Loop_Actions (P)), Ins_Actions);
1699 -- Another special case, an attribute denoting a procedure call
1702 N_Attribute_Reference =>
1703 if Is_Procedure_Attribute_Name (Attribute_Name (P)) then
1704 if P = Wrapped_Node then
1705 Store_Before_Actions_In_Scope (Ins_Actions);
1707 Insert_List_Before_And_Analyze (P, Ins_Actions);
1712 -- In the subexpression case, keep climbing
1718 -- For all other node types, keep climbing tree
1722 N_Accept_Alternative |
1723 N_Access_Definition |
1724 N_Access_Function_Definition |
1725 N_Access_Procedure_Definition |
1726 N_Access_To_Object_Definition |
1729 N_Case_Statement_Alternative |
1730 N_Character_Literal |
1731 N_Compilation_Unit |
1732 N_Compilation_Unit_Aux |
1733 N_Component_Clause |
1734 N_Component_Declaration |
1736 N_Constrained_Array_Definition |
1737 N_Decimal_Fixed_Point_Definition |
1738 N_Defining_Character_Literal |
1739 N_Defining_Identifier |
1740 N_Defining_Operator_Symbol |
1741 N_Defining_Program_Unit_Name |
1742 N_Delay_Alternative |
1743 N_Delta_Constraint |
1744 N_Derived_Type_Definition |
1746 N_Digits_Constraint |
1747 N_Discriminant_Association |
1748 N_Discriminant_Specification |
1750 N_Entry_Body_Formal_Part |
1751 N_Entry_Call_Alternative |
1752 N_Entry_Declaration |
1753 N_Entry_Index_Specification |
1754 N_Enumeration_Type_Definition |
1756 N_Exception_Handler |
1758 N_Explicit_Dereference |
1759 N_Extension_Aggregate |
1760 N_Floating_Point_Definition |
1761 N_Formal_Decimal_Fixed_Point_Definition |
1762 N_Formal_Derived_Type_Definition |
1763 N_Formal_Discrete_Type_Definition |
1764 N_Formal_Floating_Point_Definition |
1765 N_Formal_Modular_Type_Definition |
1766 N_Formal_Ordinary_Fixed_Point_Definition |
1767 N_Formal_Package_Declaration |
1768 N_Formal_Private_Type_Definition |
1769 N_Formal_Signed_Integer_Type_Definition |
1771 N_Function_Specification |
1772 N_Generic_Association |
1773 N_Handled_Sequence_Of_Statements |
1776 N_Index_Or_Discriminant_Constraint |
1777 N_Indexed_Component |
1781 N_Loop_Parameter_Specification |
1783 N_Modular_Type_Definition |
1809 N_Op_Shift_Right_Arithmetic |
1813 N_Ordinary_Fixed_Point_Definition |
1815 N_Package_Specification |
1816 N_Parameter_Association |
1817 N_Parameter_Specification |
1818 N_Pragma_Argument_Association |
1819 N_Procedure_Specification |
1821 N_Protected_Definition |
1822 N_Qualified_Expression |
1824 N_Range_Constraint |
1826 N_Real_Range_Specification |
1827 N_Record_Definition |
1829 N_Selected_Component |
1830 N_Signed_Integer_Type_Definition |
1831 N_Single_Protected_Declaration |
1835 N_Subtype_Indication |
1838 N_Terminate_Alternative |
1839 N_Triggering_Alternative |
1841 N_Unchecked_Expression |
1842 N_Unchecked_Type_Conversion |
1843 N_Unconstrained_Array_Definition |
1846 N_Use_Package_Clause |
1850 N_Validate_Unchecked_Conversion |
1858 -- Make sure that inserted actions stay in the transient scope
1860 if P = Wrapped_Node then
1861 Store_Before_Actions_In_Scope (Ins_Actions);
1865 -- If we fall through above tests, keep climbing tree
1869 if Nkind (Parent (N)) = N_Subunit then
1871 -- This is the proper body corresponding to a stub. Insertion
1872 -- must be done at the point of the stub, which is in the decla-
1873 -- tive part of the parent unit.
1875 P := Corresponding_Stub (Parent (N));
1884 -- Version with check(s) suppressed
1886 procedure Insert_Actions
1887 (Assoc_Node : Node_Id; Ins_Actions : List_Id; Suppress : Check_Id)
1890 if Suppress = All_Checks then
1892 Svg : constant Suppress_Record := Scope_Suppress;
1895 Scope_Suppress := (others => True);
1896 Insert_Actions (Assoc_Node, Ins_Actions);
1897 Scope_Suppress := Svg;
1902 Svg : constant Boolean := Get_Scope_Suppress (Suppress);
1905 Set_Scope_Suppress (Suppress, True);
1906 Insert_Actions (Assoc_Node, Ins_Actions);
1907 Set_Scope_Suppress (Suppress, Svg);
1912 --------------------------
1913 -- Insert_Actions_After --
1914 --------------------------
1916 procedure Insert_Actions_After
1917 (Assoc_Node : Node_Id;
1918 Ins_Actions : List_Id)
1921 if Scope_Is_Transient
1922 and then Assoc_Node = Node_To_Be_Wrapped
1924 Store_After_Actions_In_Scope (Ins_Actions);
1926 Insert_List_After_And_Analyze (Assoc_Node, Ins_Actions);
1928 end Insert_Actions_After;
1930 ---------------------------------
1931 -- Insert_Library_Level_Action --
1932 ---------------------------------
1934 procedure Insert_Library_Level_Action (N : Node_Id) is
1935 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
1938 New_Scope (Cunit_Entity (Main_Unit));
1940 if No (Actions (Aux)) then
1941 Set_Actions (Aux, New_List (N));
1943 Append (N, Actions (Aux));
1948 end Insert_Library_Level_Action;
1950 ----------------------------------
1951 -- Insert_Library_Level_Actions --
1952 ----------------------------------
1954 procedure Insert_Library_Level_Actions (L : List_Id) is
1955 Aux : constant Node_Id := Aux_Decls_Node (Cunit (Main_Unit));
1958 if Is_Non_Empty_List (L) then
1959 New_Scope (Cunit_Entity (Main_Unit));
1961 if No (Actions (Aux)) then
1962 Set_Actions (Aux, L);
1965 Insert_List_After_And_Analyze (Last (Actions (Aux)), L);
1970 end Insert_Library_Level_Actions;
1972 ----------------------
1973 -- Inside_Init_Proc --
1974 ----------------------
1976 function Inside_Init_Proc return Boolean is
1981 while S /= Standard_Standard loop
1982 if Chars (S) = Name_uInit_Proc then
1990 end Inside_Init_Proc;
1992 --------------------------------
1993 -- Is_Ref_To_Bit_Packed_Array --
1994 --------------------------------
1996 function Is_Ref_To_Bit_Packed_Array (P : Node_Id) return Boolean is
2001 if Nkind (P) = N_Indexed_Component
2003 Nkind (P) = N_Selected_Component
2005 if Is_Bit_Packed_Array (Etype (Prefix (P))) then
2008 Result := Is_Ref_To_Bit_Packed_Array (Prefix (P));
2011 if Result and then Nkind (P) = N_Indexed_Component then
2012 Expr := First (Expressions (P));
2014 while Present (Expr) loop
2015 Force_Evaluation (Expr);
2025 end Is_Ref_To_Bit_Packed_Array;
2027 --------------------------------
2028 -- Is_Ref_To_Bit_Packed_Slce --
2029 --------------------------------
2031 function Is_Ref_To_Bit_Packed_Slice (P : Node_Id) return Boolean is
2033 if Nkind (P) = N_Slice
2034 and then Is_Bit_Packed_Array (Etype (Prefix (P)))
2038 elsif Nkind (P) = N_Indexed_Component
2040 Nkind (P) = N_Selected_Component
2042 return Is_Ref_To_Bit_Packed_Slice (Prefix (P));
2047 end Is_Ref_To_Bit_Packed_Slice;
2049 -----------------------
2050 -- Is_Renamed_Object --
2051 -----------------------
2053 function Is_Renamed_Object (N : Node_Id) return Boolean is
2054 Pnod : constant Node_Id := Parent (N);
2055 Kind : constant Node_Kind := Nkind (Pnod);
2058 if Kind = N_Object_Renaming_Declaration then
2061 elsif Kind = N_Indexed_Component
2062 or else Kind = N_Selected_Component
2064 return Is_Renamed_Object (Pnod);
2069 end Is_Renamed_Object;
2071 ----------------------------
2072 -- Is_Untagged_Derivation --
2073 ----------------------------
2075 function Is_Untagged_Derivation (T : Entity_Id) return Boolean is
2077 return (not Is_Tagged_Type (T) and then Is_Derived_Type (T))
2079 (Is_Private_Type (T) and then Present (Full_View (T))
2080 and then not Is_Tagged_Type (Full_View (T))
2081 and then Is_Derived_Type (Full_View (T))
2082 and then Etype (Full_View (T)) /= T);
2084 end Is_Untagged_Derivation;
2086 --------------------
2087 -- Kill_Dead_Code --
2088 --------------------
2090 procedure Kill_Dead_Code (N : Node_Id) is
2093 Remove_Handler_Entries (N);
2094 Remove_Warning_Messages (N);
2096 -- Recurse into block statements to process declarations/statements
2098 if Nkind (N) = N_Block_Statement then
2099 Kill_Dead_Code (Declarations (N));
2100 Kill_Dead_Code (Statements (Handled_Statement_Sequence (N)));
2102 -- Recurse into composite statement to kill individual statements,
2103 -- in particular instantiations.
2105 elsif Nkind (N) = N_If_Statement then
2106 Kill_Dead_Code (Then_Statements (N));
2107 Kill_Dead_Code (Elsif_Parts (N));
2108 Kill_Dead_Code (Else_Statements (N));
2110 elsif Nkind (N) = N_Loop_Statement then
2111 Kill_Dead_Code (Statements (N));
2113 elsif Nkind (N) = N_Case_Statement then
2115 Alt : Node_Id := First (Alternatives (N));
2118 while Present (Alt) loop
2119 Kill_Dead_Code (Statements (Alt));
2124 -- Deal with dead instances caused by deleting instantiations
2126 elsif Nkind (N) in N_Generic_Instantiation then
2127 Remove_Dead_Instance (N);
2134 -- Case where argument is a list of nodes to be killed
2136 procedure Kill_Dead_Code (L : List_Id) is
2140 if Is_Non_Empty_List (L) then
2142 N := Remove_Head (L);
2149 ------------------------
2150 -- Known_Non_Negative --
2151 ------------------------
2153 function Known_Non_Negative (Opnd : Node_Id) return Boolean is
2155 if Is_OK_Static_Expression (Opnd)
2156 and then Expr_Value (Opnd) >= 0
2162 Lo : constant Node_Id := Type_Low_Bound (Etype (Opnd));
2166 Is_OK_Static_Expression (Lo) and then Expr_Value (Lo) >= 0;
2169 end Known_Non_Negative;
2171 -----------------------------
2172 -- Make_CW_Equivalent_Type --
2173 -----------------------------
2175 -- Create a record type used as an equivalent of any member
2176 -- of the class which takes its size from exp.
2178 -- Generate the following code:
2180 -- type Equiv_T is record
2181 -- _parent : T (List of discriminant constaints taken from Exp);
2182 -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'size) / Storage_Unit);
2185 function Make_CW_Equivalent_Type
2190 Loc : constant Source_Ptr := Sloc (E);
2191 Root_Typ : constant Entity_Id := Root_Type (T);
2192 Equiv_Type : Entity_Id;
2193 Range_Type : Entity_Id;
2194 Str_Type : Entity_Id;
2195 List_Def : List_Id := Empty_List;
2196 Constr_Root : Entity_Id;
2200 if not Has_Discriminants (Root_Typ) then
2201 Constr_Root := Root_Typ;
2204 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2206 -- subtype cstr__n is T (List of discr constraints taken from Exp)
2208 Append_To (List_Def,
2209 Make_Subtype_Declaration (Loc,
2210 Defining_Identifier => Constr_Root,
2211 Subtype_Indication =>
2212 Make_Subtype_From_Expr (E, Root_Typ)));
2215 -- subtype rg__xx is Storage_Offset range
2216 -- (Expr'size - typ'size) / Storage_Unit
2218 Range_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('G'));
2221 Make_Op_Subtract (Loc,
2223 Make_Attribute_Reference (Loc,
2224 Prefix => OK_Convert_To (T, Duplicate_Subexpr (E)),
2225 Attribute_Name => Name_Size),
2227 Make_Attribute_Reference (Loc,
2228 Prefix => New_Reference_To (Constr_Root, Loc),
2229 Attribute_Name => Name_Size));
2231 Set_Paren_Count (Sizexpr, 1);
2233 Append_To (List_Def,
2234 Make_Subtype_Declaration (Loc,
2235 Defining_Identifier => Range_Type,
2236 Subtype_Indication =>
2237 Make_Subtype_Indication (Loc,
2238 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Offset), Loc),
2239 Constraint => Make_Range_Constraint (Loc,
2242 Low_Bound => Make_Integer_Literal (Loc, 1),
2244 Make_Op_Divide (Loc,
2245 Left_Opnd => Sizexpr,
2246 Right_Opnd => Make_Integer_Literal (Loc,
2247 Intval => System_Storage_Unit)))))));
2249 -- subtype str__nn is Storage_Array (rg__x);
2251 Str_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('S'));
2252 Append_To (List_Def,
2253 Make_Subtype_Declaration (Loc,
2254 Defining_Identifier => Str_Type,
2255 Subtype_Indication =>
2256 Make_Subtype_Indication (Loc,
2257 Subtype_Mark => New_Reference_To (RTE (RE_Storage_Array), Loc),
2259 Make_Index_Or_Discriminant_Constraint (Loc,
2261 New_List (New_Reference_To (Range_Type, Loc))))));
2263 -- type Equiv_T is record
2268 Equiv_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('T'));
2270 -- Avoid the generation of an init procedure
2272 Set_Is_Frozen (Equiv_Type);
2274 Set_Ekind (Equiv_Type, E_Record_Type);
2275 Set_Parent_Subtype (Equiv_Type, Constr_Root);
2277 Append_To (List_Def,
2278 Make_Full_Type_Declaration (Loc,
2279 Defining_Identifier => Equiv_Type,
2282 Make_Record_Definition (Loc,
2283 Component_List => Make_Component_List (Loc,
2284 Component_Items => New_List (
2285 Make_Component_Declaration (Loc,
2286 Defining_Identifier =>
2287 Make_Defining_Identifier (Loc, Name_uParent),
2288 Subtype_Indication => New_Reference_To (Constr_Root, Loc)),
2290 Make_Component_Declaration (Loc,
2291 Defining_Identifier =>
2292 Make_Defining_Identifier (Loc,
2293 Chars => New_Internal_Name ('C')),
2294 Subtype_Indication => New_Reference_To (Str_Type, Loc))),
2295 Variant_Part => Empty))));
2297 Insert_Actions (E, List_Def);
2299 end Make_CW_Equivalent_Type;
2301 ------------------------
2302 -- Make_Literal_Range --
2303 ------------------------
2305 function Make_Literal_Range
2307 Literal_Typ : Entity_Id)
2311 New_Copy_Tree (String_Literal_Low_Bound (Literal_Typ));
2314 Set_Analyzed (Lo, False);
2321 Make_Op_Subtract (Loc,
2324 Left_Opnd => New_Copy_Tree (Lo),
2326 Make_Integer_Literal (Loc,
2327 String_Literal_Length (Literal_Typ))),
2328 Right_Opnd => Make_Integer_Literal (Loc, 1)));
2329 end Make_Literal_Range;
2331 ----------------------------
2332 -- Make_Subtype_From_Expr --
2333 ----------------------------
2335 -- 1. If Expr is an uncontrained array expression, creates
2336 -- Unc_Type(Expr'first(1)..Expr'Last(1),..., Expr'first(n)..Expr'last(n))
2338 -- 2. If Expr is a unconstrained discriminated type expression, creates
2339 -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
2341 -- 3. If Expr is class-wide, creates an implicit class wide subtype
2343 function Make_Subtype_From_Expr
2345 Unc_Typ : Entity_Id)
2348 Loc : constant Source_Ptr := Sloc (E);
2349 List_Constr : List_Id := New_List;
2352 Full_Subtyp : Entity_Id;
2353 Priv_Subtyp : Entity_Id;
2358 if Is_Private_Type (Unc_Typ)
2359 and then Has_Unknown_Discriminants (Unc_Typ)
2361 -- Prepare the subtype completion
2363 Utyp := Underlying_Type (Unc_Typ);
2364 Full_Subtyp := Make_Defining_Identifier (Loc,
2365 New_Internal_Name ('C'));
2366 Full_Exp := Unchecked_Convert_To (Utyp, Duplicate_Subexpr (E));
2367 Set_Parent (Full_Exp, Parent (E));
2370 Make_Defining_Identifier (Loc, New_Internal_Name ('P'));
2373 Make_Subtype_Declaration (Loc,
2374 Defining_Identifier => Full_Subtyp,
2375 Subtype_Indication => Make_Subtype_From_Expr (Full_Exp, Utyp)));
2377 -- Define the dummy private subtype
2379 Set_Ekind (Priv_Subtyp, Subtype_Kind (Ekind (Unc_Typ)));
2380 Set_Etype (Priv_Subtyp, Unc_Typ);
2381 Set_Scope (Priv_Subtyp, Full_Subtyp);
2382 Set_Is_Constrained (Priv_Subtyp);
2383 Set_Is_Tagged_Type (Priv_Subtyp, Is_Tagged_Type (Unc_Typ));
2384 Set_Is_Itype (Priv_Subtyp);
2385 Set_Associated_Node_For_Itype (Priv_Subtyp, E);
2387 if Is_Tagged_Type (Priv_Subtyp) then
2389 (Base_Type (Priv_Subtyp), Class_Wide_Type (Unc_Typ));
2390 Set_Primitive_Operations (Priv_Subtyp,
2391 Primitive_Operations (Unc_Typ));
2394 Set_Full_View (Priv_Subtyp, Full_Subtyp);
2396 return New_Reference_To (Priv_Subtyp, Loc);
2398 elsif Is_Array_Type (Unc_Typ) then
2399 for J in 1 .. Number_Dimensions (Unc_Typ) loop
2400 Append_To (List_Constr,
2403 Make_Attribute_Reference (Loc,
2404 Prefix => Duplicate_Subexpr (E),
2405 Attribute_Name => Name_First,
2406 Expressions => New_List (
2407 Make_Integer_Literal (Loc, J))),
2409 Make_Attribute_Reference (Loc,
2410 Prefix => Duplicate_Subexpr (E),
2411 Attribute_Name => Name_Last,
2412 Expressions => New_List (
2413 Make_Integer_Literal (Loc, J)))));
2416 elsif Is_Class_Wide_Type (Unc_Typ) then
2418 CW_Subtype : Entity_Id;
2419 EQ_Typ : Entity_Id := Empty;
2422 -- A class-wide equivalent type is not needed when Java_VM
2423 -- because the JVM back end handles the class-wide object
2424 -- initialization itself (and doesn't need or want the
2425 -- additional intermediate type to handle the assignment).
2427 if Expander_Active and then not Java_VM then
2428 EQ_Typ := Make_CW_Equivalent_Type (Unc_Typ, E);
2431 CW_Subtype := New_Class_Wide_Subtype (Unc_Typ, E);
2432 Set_Equivalent_Type (CW_Subtype, EQ_Typ);
2433 Set_Cloned_Subtype (CW_Subtype, Base_Type (Unc_Typ));
2435 return New_Occurrence_Of (CW_Subtype, Loc);
2439 D := First_Discriminant (Unc_Typ);
2440 while (Present (D)) loop
2442 Append_To (List_Constr,
2443 Make_Selected_Component (Loc,
2444 Prefix => Duplicate_Subexpr (E),
2445 Selector_Name => New_Reference_To (D, Loc)));
2447 Next_Discriminant (D);
2452 Make_Subtype_Indication (Loc,
2453 Subtype_Mark => New_Reference_To (Unc_Typ, Loc),
2455 Make_Index_Or_Discriminant_Constraint (Loc,
2456 Constraints => List_Constr));
2457 end Make_Subtype_From_Expr;
2459 -----------------------------
2460 -- May_Generate_Large_Temp --
2461 -----------------------------
2463 -- At the current time, the only types that we return False for (i.e.
2464 -- where we decide we know they cannot generate large temps) are ones
2465 -- where we know the size is 128 bits or less at compile time, and we
2466 -- are still not doing a thorough job on arrays and records ???
2468 function May_Generate_Large_Temp (Typ : Entity_Id) return Boolean is
2470 if not Stack_Checking_Enabled then
2473 elsif not Size_Known_At_Compile_Time (Typ) then
2476 elsif Esize (Typ) /= 0 and then Esize (Typ) <= 256 then
2479 elsif Is_Array_Type (Typ)
2480 and then Present (Packed_Array_Type (Typ))
2482 return May_Generate_Large_Temp (Packed_Array_Type (Typ));
2484 -- We could do more here to find other small types ???
2489 end May_Generate_Large_Temp;
2491 ----------------------------
2492 -- New_Class_Wide_Subtype --
2493 ----------------------------
2495 function New_Class_Wide_Subtype
2496 (CW_Typ : Entity_Id;
2500 Res : Entity_Id := Create_Itype (E_Void, N);
2501 Res_Name : constant Name_Id := Chars (Res);
2502 Res_Scope : Entity_Id := Scope (Res);
2505 Copy_Node (CW_Typ, Res);
2506 Set_Sloc (Res, Sloc (N));
2508 Set_Associated_Node_For_Itype (Res, N);
2509 Set_Is_Public (Res, False); -- By default, may be changed below.
2510 Set_Public_Status (Res);
2511 Set_Chars (Res, Res_Name);
2512 Set_Scope (Res, Res_Scope);
2513 Set_Ekind (Res, E_Class_Wide_Subtype);
2514 Set_Next_Entity (Res, Empty);
2515 Set_Etype (Res, Base_Type (CW_Typ));
2516 Set_Freeze_Node (Res, Empty);
2518 end New_Class_Wide_Subtype;
2520 -------------------------
2521 -- Remove_Side_Effects --
2522 -------------------------
2524 procedure Remove_Side_Effects
2526 Name_Req : Boolean := False;
2527 Variable_Ref : Boolean := False)
2529 Loc : constant Source_Ptr := Sloc (Exp);
2530 Exp_Type : constant Entity_Id := Etype (Exp);
2531 Svg_Suppress : constant Suppress_Record := Scope_Suppress;
2533 Ref_Type : Entity_Id;
2535 Ptr_Typ_Decl : Node_Id;
2539 function Side_Effect_Free (N : Node_Id) return Boolean;
2540 -- Determines if the tree N represents an expession that is known
2541 -- not to have side effects, and for which no processing is required.
2543 function Side_Effect_Free (L : List_Id) return Boolean;
2544 -- Determines if all elements of the list L are side effect free
2546 function Mutable_Dereference (N : Node_Id) return Boolean;
2547 -- If a selected component involves an implicit dereference and
2548 -- the type of the prefix is not an_access_to_constant, the node
2549 -- must be evaluated because it may be affected by a subsequent
2552 -------------------------
2553 -- Mutable_Dereference --
2554 -------------------------
2556 function Mutable_Dereference (N : Node_Id) return Boolean is
2558 return Nkind (N) = N_Selected_Component
2559 and then Is_Access_Type (Etype (Prefix (N)))
2560 and then not Is_Access_Constant (Etype (Prefix (N)))
2561 and then Variable_Ref;
2562 end Mutable_Dereference;
2564 ----------------------
2565 -- Side_Effect_Free --
2566 ----------------------
2568 function Side_Effect_Free (N : Node_Id) return Boolean is
2569 K : constant Node_Kind := Nkind (N);
2572 -- Note on checks that could raise Constraint_Error. Strictly, if
2573 -- we take advantage of 11.6, these checks do not count as side
2574 -- effects. However, we would just as soon consider that they are
2575 -- side effects, since the backend CSE does not work very well on
2576 -- expressions which can raise Constraint_Error. On the other
2577 -- hand, if we do not consider them to be side effect free, then
2578 -- we get some awkward expansions in -gnato mode, resulting in
2579 -- code insertions at a point where we do not have a clear model
2580 -- for performing the insertions. See 4908-002/comment for details.
2582 -- An attribute reference is side effect free if its expressions
2583 -- are side effect free and its prefix is (could be a dereference
2584 -- or an indexed retrieval for example).
2586 if K = N_Attribute_Reference then
2587 return Side_Effect_Free (Expressions (N))
2588 and then (Is_Entity_Name (Prefix (N))
2589 or else Side_Effect_Free (Prefix (N)));
2591 -- An entity is side effect free unless it is a function call, or
2592 -- a reference to a volatile variable and Name_Req is False. If
2593 -- Name_Req is True then we can't help returning a name which
2594 -- effectively allows multiple references in any case.
2596 elsif Is_Entity_Name (N)
2597 and then Ekind (Entity (N)) /= E_Function
2598 and then (not Is_Volatile (Entity (N)) or else Name_Req)
2600 -- If the entity is a constant, it is definitely side effect
2601 -- free. Note that the test of Is_Variable (N) below might
2602 -- be expected to catch this case, but it does not, because
2603 -- this test goes to the original tree, and we may have
2604 -- already rewritten a variable node with a constant as
2605 -- a result of an earlier Force_Evaluation call.
2607 if Ekind (Entity (N)) = E_Constant then
2610 -- If the Variable_Ref flag is set, any variable reference is
2611 -- is considered a side-effect
2613 elsif Variable_Ref then
2614 return not Is_Variable (N);
2620 -- A value known at compile time is always side effect free
2622 elsif Compile_Time_Known_Value (N) then
2625 -- Literals are always side-effect free
2627 elsif (K = N_Integer_Literal
2628 or else K = N_Real_Literal
2629 or else K = N_Character_Literal
2630 or else K = N_String_Literal
2632 and then not Raises_Constraint_Error (N)
2636 -- A type conversion or qualification is side effect free if the
2637 -- expression to be converted is side effect free.
2639 elsif K = N_Type_Conversion or else K = N_Qualified_Expression then
2640 return Side_Effect_Free (Expression (N));
2642 -- An unchecked type conversion is never side effect free since we
2643 -- need to check whether it is safe.
2644 -- effect free if its argument is side effect free.
2646 elsif K = N_Unchecked_Type_Conversion then
2647 if Safe_Unchecked_Type_Conversion (N) then
2648 return Side_Effect_Free (Expression (N));
2653 -- A unary operator is side effect free if the operand
2654 -- is side effect free.
2656 elsif K in N_Unary_Op then
2657 return Side_Effect_Free (Right_Opnd (N));
2659 -- A binary operator is side effect free if and both operands
2660 -- are side effect free.
2662 elsif K in N_Binary_Op then
2663 return Side_Effect_Free (Left_Opnd (N))
2664 and then Side_Effect_Free (Right_Opnd (N));
2666 -- An explicit dereference or selected component is side effect
2667 -- free if its prefix is side effect free.
2669 elsif K = N_Explicit_Dereference
2670 or else K = N_Selected_Component
2672 return Side_Effect_Free (Prefix (N))
2673 and then not Mutable_Dereference (Prefix (N));
2675 -- An indexed component can be copied if the prefix is copyable
2676 -- and all the indexing expressions are copyable and there is
2677 -- no access check and no range checks.
2679 elsif K = N_Indexed_Component then
2680 return Side_Effect_Free (Prefix (N))
2681 and then Side_Effect_Free (Expressions (N));
2683 elsif K = N_Unchecked_Expression then
2684 return Side_Effect_Free (Expression (N));
2686 -- A call to _rep_to_pos is side effect free, since we generate
2687 -- this pure function call ourselves. Moreover it is critically
2688 -- important to make this exception, since otherwise we can
2689 -- have discriminants in array components which don't look
2690 -- side effect free in the case of an array whose index type
2691 -- is an enumeration type with an enumeration rep clause.
2693 elsif K = N_Function_Call
2694 and then Nkind (Name (N)) = N_Identifier
2695 and then Chars (Name (N)) = Name_uRep_To_Pos
2699 -- We consider that anything else has side effects. This is a bit
2700 -- crude, but we are pretty close for most common cases, and we
2701 -- are certainly correct (i.e. we never return True when the
2702 -- answer should be False).
2707 end Side_Effect_Free;
2709 function Side_Effect_Free (L : List_Id) return Boolean is
2713 if L = No_List or else L = Error_List then
2719 while Present (N) loop
2720 if not Side_Effect_Free (N) then
2729 end Side_Effect_Free;
2731 -- Start of processing for Remove_Side_Effects
2734 -- If we are side effect free already or expansion is disabled,
2735 -- there is nothing to do.
2737 if Side_Effect_Free (Exp) or else not Expander_Active then
2741 -- All the must not have any checks
2743 Scope_Suppress := (others => True);
2745 -- If the expression has the form v.all then we can just capture
2746 -- the pointer, and then do an explicit dereference on the result.
2748 if Nkind (Exp) = N_Explicit_Dereference then
2750 Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2752 Make_Explicit_Dereference (Loc, New_Reference_To (Def_Id, Loc));
2755 Make_Object_Declaration (Loc,
2756 Defining_Identifier => Def_Id,
2757 Object_Definition =>
2758 New_Reference_To (Etype (Prefix (Exp)), Loc),
2759 Constant_Present => True,
2760 Expression => Relocate_Node (Prefix (Exp))));
2762 -- If this is a type conversion, leave the type conversion and remove
2763 -- the side effects in the expression. This is important in several
2764 -- circumstances: for change of representations, and also when this
2765 -- is a view conversion to a smaller object, where gigi can end up
2766 -- its own temporary of the wrong size.
2768 -- ??? this transformation is inhibited for elementary types that are
2769 -- not involved in a change of representation because it causes
2770 -- regressions that are not fully understood yet.
2772 elsif Nkind (Exp) = N_Type_Conversion
2773 and then (not Is_Elementary_Type (Underlying_Type (Exp_Type))
2774 or else Nkind (Parent (Exp)) = N_Assignment_Statement)
2776 Remove_Side_Effects (Expression (Exp), Variable_Ref);
2777 Scope_Suppress := Svg_Suppress;
2780 -- For expressions that denote objects, we can use a renaming scheme.
2781 -- We skip using this if we have a volatile variable and we do not
2782 -- have Nam_Req set true (see comments above for Side_Effect_Free).
2783 -- We also skip this scheme for class-wide expressions in order to
2784 -- avoid recursive expension (see Expand_N_Object_Renaming_Declaration)
2785 -- If the object is a function call, we need to create a temporary and
2788 elsif Is_Object_Reference (Exp)
2789 and then Nkind (Exp) /= N_Function_Call
2790 and then not Variable_Ref
2792 or else not Is_Entity_Name (Exp)
2793 or else not Is_Volatile (Entity (Exp)))
2794 and then not Is_Class_Wide_Type (Exp_Type)
2796 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2798 if Nkind (Exp) = N_Selected_Component
2799 and then Nkind (Prefix (Exp)) = N_Function_Call
2800 and then Is_Array_Type (Etype (Exp))
2802 -- Avoid generating a variable-sized temporary, by generating
2803 -- the renaming declaration just for the function call. The
2804 -- transformation could be refined to apply only when the array
2805 -- component is constrained by a discriminant???
2808 Make_Selected_Component (Loc,
2809 Prefix => New_Occurrence_Of (Def_Id, Loc),
2810 Selector_Name => Selector_Name (Exp));
2813 Make_Object_Renaming_Declaration (Loc,
2814 Defining_Identifier => Def_Id,
2816 New_Reference_To (Base_Type (Etype (Prefix (Exp))), Loc),
2817 Name => Relocate_Node (Prefix (Exp))));
2819 Res := New_Reference_To (Def_Id, Loc);
2822 Make_Object_Renaming_Declaration (Loc,
2823 Defining_Identifier => Def_Id,
2824 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
2825 Name => Relocate_Node (Exp)));
2828 -- If it is a scalar type, just make a copy.
2830 elsif Is_Elementary_Type (Exp_Type) then
2831 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2832 Set_Etype (Def_Id, Exp_Type);
2833 Res := New_Reference_To (Def_Id, Loc);
2836 Make_Object_Declaration (Loc,
2837 Defining_Identifier => Def_Id,
2838 Object_Definition => New_Reference_To (Exp_Type, Loc),
2839 Constant_Present => True,
2840 Expression => Relocate_Node (Exp));
2842 Set_Assignment_OK (E);
2843 Insert_Action (Exp, E);
2845 -- If this is an unchecked conversion that Gigi can't handle, make
2846 -- a copy or a use a renaming to capture the value.
2848 elsif (Nkind (Exp) = N_Unchecked_Type_Conversion
2849 and then not Safe_Unchecked_Type_Conversion (Exp))
2851 if Controlled_Type (Etype (Exp)) then
2852 -- Use a renaming to capture the expression, rather than create
2853 -- a controlled temporary.
2855 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2856 Res := New_Reference_To (Def_Id, Loc);
2859 Make_Object_Renaming_Declaration (Loc,
2860 Defining_Identifier => Def_Id,
2861 Subtype_Mark => New_Reference_To (Exp_Type, Loc),
2862 Name => Relocate_Node (Exp)));
2865 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2866 Set_Etype (Def_Id, Exp_Type);
2867 Res := New_Reference_To (Def_Id, Loc);
2870 Make_Object_Declaration (Loc,
2871 Defining_Identifier => Def_Id,
2872 Object_Definition => New_Reference_To (Exp_Type, Loc),
2873 Constant_Present => True,
2874 Expression => Relocate_Node (Exp));
2876 Set_Assignment_OK (E);
2877 Insert_Action (Exp, E);
2880 -- Otherwise we generate a reference to the value
2883 Ref_Type := Make_Defining_Identifier (Loc, New_Internal_Name ('A'));
2886 Make_Full_Type_Declaration (Loc,
2887 Defining_Identifier => Ref_Type,
2889 Make_Access_To_Object_Definition (Loc,
2890 All_Present => True,
2891 Subtype_Indication =>
2892 New_Reference_To (Exp_Type, Loc)));
2895 Insert_Action (Exp, Ptr_Typ_Decl);
2897 Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('R'));
2898 Set_Etype (Def_Id, Exp_Type);
2901 Make_Explicit_Dereference (Loc,
2902 Prefix => New_Reference_To (Def_Id, Loc));
2904 if Nkind (E) = N_Explicit_Dereference then
2905 New_Exp := Relocate_Node (Prefix (E));
2907 E := Relocate_Node (E);
2908 New_Exp := Make_Reference (Loc, E);
2911 if Nkind (E) = N_Aggregate and then Expansion_Delayed (E) then
2912 Set_Expansion_Delayed (E, False);
2913 Set_Analyzed (E, False);
2917 Make_Object_Declaration (Loc,
2918 Defining_Identifier => Def_Id,
2919 Object_Definition => New_Reference_To (Ref_Type, Loc),
2920 Expression => New_Exp));
2923 -- Preserve the Assignment_OK flag in all copies, since at least
2924 -- one copy may be used in a context where this flag must be set
2925 -- (otherwise why would the flag be set in the first place).
2927 Set_Assignment_OK (Res, Assignment_OK (Exp));
2929 -- Finally rewrite the original expression and we are done
2932 Analyze_And_Resolve (Exp, Exp_Type);
2933 Scope_Suppress := Svg_Suppress;
2934 end Remove_Side_Effects;
2936 ------------------------------------
2937 -- Safe_Unchecked_Type_Conversion --
2938 ------------------------------------
2940 -- Note: this function knows quite a bit about the exact requirements
2941 -- of Gigi with respect to unchecked type conversions, and its code
2942 -- must be coordinated with any changes in Gigi in this area.
2944 -- The above requirements should be documented in Sinfo ???
2946 function Safe_Unchecked_Type_Conversion (Exp : Node_Id) return Boolean is
2951 Pexp : constant Node_Id := Parent (Exp);
2954 -- If the expression is the RHS of an assignment or object declaration
2955 -- we are always OK because there will always be a target.
2957 -- Object renaming declarations, (generated for view conversions of
2958 -- actuals in inlined calls), like object declarations, provide an
2959 -- explicit type, and are safe as well.
2961 if (Nkind (Pexp) = N_Assignment_Statement
2962 and then Expression (Pexp) = Exp)
2963 or else Nkind (Pexp) = N_Object_Declaration
2964 or else Nkind (Pexp) = N_Object_Renaming_Declaration
2968 -- If the expression is the prefix of an N_Selected_Component
2969 -- we should also be OK because GCC knows to look inside the
2970 -- conversion except if the type is discriminated. We assume
2971 -- that we are OK anyway if the type is not set yet or if it is
2972 -- controlled since we can't afford to introduce a temporary in
2975 elsif Nkind (Pexp) = N_Selected_Component
2976 and then Prefix (Pexp) = Exp
2978 if No (Etype (Pexp)) then
2982 not Has_Discriminants (Etype (Pexp))
2983 or else Is_Constrained (Etype (Pexp));
2987 -- Set the output type, this comes from Etype if it is set, otherwise
2988 -- we take it from the subtype mark, which we assume was already
2991 if Present (Etype (Exp)) then
2992 Otyp := Etype (Exp);
2994 Otyp := Entity (Subtype_Mark (Exp));
2997 -- The input type always comes from the expression, and we assume
2998 -- this is indeed always analyzed, so we can simply get the Etype.
3000 Ityp := Etype (Expression (Exp));
3002 -- Initialize alignments to unknown so far
3007 -- Replace a concurrent type by its corresponding record type
3008 -- and each type by its underlying type and do the tests on those.
3009 -- The original type may be a private type whose completion is a
3010 -- concurrent type, so find the underlying type first.
3012 if Present (Underlying_Type (Otyp)) then
3013 Otyp := Underlying_Type (Otyp);
3016 if Present (Underlying_Type (Ityp)) then
3017 Ityp := Underlying_Type (Ityp);
3020 if Is_Concurrent_Type (Otyp) then
3021 Otyp := Corresponding_Record_Type (Otyp);
3024 if Is_Concurrent_Type (Ityp) then
3025 Ityp := Corresponding_Record_Type (Ityp);
3028 -- If the base types are the same, we know there is no problem since
3029 -- this conversion will be a noop.
3031 if Implementation_Base_Type (Otyp) = Implementation_Base_Type (Ityp) then
3034 -- If the size of output type is known at compile time, there is
3035 -- never a problem. Note that unconstrained records are considered
3036 -- to be of known size, but we can't consider them that way here,
3037 -- because we are talking about the actual size of the object.
3039 -- We also make sure that in addition to the size being known, we do
3040 -- not have a case which might generate an embarrassingly large temp
3041 -- in stack checking mode.
3043 elsif Size_Known_At_Compile_Time (Otyp)
3044 and then not May_Generate_Large_Temp (Otyp)
3045 and then not (Is_Record_Type (Otyp) and then not Is_Constrained (Otyp))
3049 -- If either type is tagged, then we know the alignment is OK so
3050 -- Gigi will be able to use pointer punning.
3052 elsif Is_Tagged_Type (Otyp) or else Is_Tagged_Type (Ityp) then
3055 -- If either type is a limited record type, we cannot do a copy, so
3056 -- say safe since there's nothing else we can do.
3058 elsif Is_Limited_Record (Otyp) or else Is_Limited_Record (Ityp) then
3061 -- Conversions to and from packed array types are always ignored and
3064 elsif Is_Packed_Array_Type (Otyp)
3065 or else Is_Packed_Array_Type (Ityp)
3070 -- The only other cases known to be safe is if the input type's
3071 -- alignment is known to be at least the maximum alignment for the
3072 -- target or if both alignments are known and the output type's
3073 -- alignment is no stricter than the input's. We can use the alignment
3074 -- of the component type of an array if a type is an unpacked
3077 if Present (Alignment_Clause (Otyp)) then
3078 Oalign := Expr_Value (Expression (Alignment_Clause (Otyp)));
3080 elsif Is_Array_Type (Otyp)
3081 and then Present (Alignment_Clause (Component_Type (Otyp)))
3083 Oalign := Expr_Value (Expression (Alignment_Clause
3084 (Component_Type (Otyp))));
3087 if Present (Alignment_Clause (Ityp)) then
3088 Ialign := Expr_Value (Expression (Alignment_Clause (Ityp)));
3090 elsif Is_Array_Type (Ityp)
3091 and then Present (Alignment_Clause (Component_Type (Ityp)))
3093 Ialign := Expr_Value (Expression (Alignment_Clause
3094 (Component_Type (Ityp))));
3097 if Ialign /= No_Uint and then Ialign > Maximum_Alignment then
3100 elsif Ialign /= No_Uint and then Oalign /= No_Uint
3101 and then Ialign <= Oalign
3105 -- Otherwise, Gigi cannot handle this and we must make a temporary.
3111 end Safe_Unchecked_Type_Conversion;
3113 --------------------------
3114 -- Set_Elaboration_Flag --
3115 --------------------------
3117 procedure Set_Elaboration_Flag (N : Node_Id; Spec_Id : Entity_Id) is
3118 Loc : constant Source_Ptr := Sloc (N);
3122 if Present (Elaboration_Entity (Spec_Id)) then
3124 -- Nothing to do if at the compilation unit level, because in this
3125 -- case the flag is set by the binder generated elaboration routine.
3127 if Nkind (Parent (N)) = N_Compilation_Unit then
3130 -- Here we do need to generate an assignment statement
3133 Check_Restriction (No_Elaboration_Code, N);
3135 Make_Assignment_Statement (Loc,
3136 Name => New_Occurrence_Of (Elaboration_Entity (Spec_Id), Loc),
3137 Expression => New_Occurrence_Of (Standard_True, Loc));
3139 if Nkind (Parent (N)) = N_Subunit then
3140 Insert_After (Corresponding_Stub (Parent (N)), Asn);
3142 Insert_After (N, Asn);
3148 end Set_Elaboration_Flag;
3150 ----------------------------
3151 -- Wrap_Cleanup_Procedure --
3152 ----------------------------
3154 procedure Wrap_Cleanup_Procedure (N : Node_Id) is
3155 Loc : constant Source_Ptr := Sloc (N);
3156 Stseq : constant Node_Id := Handled_Statement_Sequence (N);
3157 Stmts : constant List_Id := Statements (Stseq);
3160 if Abort_Allowed then
3161 Prepend_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Defer));
3162 Append_To (Stmts, Build_Runtime_Call (Loc, RE_Abort_Undefer));
3164 end Wrap_Cleanup_Procedure;