1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, 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_SCIL
; use Sem_SCIL
;
47 with Sem_Eval
; use Sem_Eval
;
48 with Sem_Res
; use Sem_Res
;
49 with Sem_Type
; use Sem_Type
;
50 with Sem_Util
; use Sem_Util
;
51 with Snames
; use Snames
;
52 with Stand
; use Stand
;
53 with Stringt
; use Stringt
;
54 with Targparm
; use Targparm
;
55 with Tbuild
; use Tbuild
;
56 with Ttypes
; use Ttypes
;
57 with Uintp
; use Uintp
;
58 with Urealp
; use Urealp
;
59 with Validsw
; use Validsw
;
61 package body Exp_Util
is
63 -----------------------
64 -- Local Subprograms --
65 -----------------------
67 function Build_Task_Array_Image
71 Dyn
: Boolean := False) return Node_Id
;
72 -- Build function to generate the image string for a task that is an
73 -- array component, concatenating the images of each index. To avoid
74 -- storage leaks, the string is built with successive slice assignments.
75 -- The flag Dyn indicates whether this is called for the initialization
76 -- procedure of an array of tasks, or for the name of a dynamically
77 -- created task that is assigned to an indexed component.
79 function Build_Task_Image_Function
83 Res
: Entity_Id
) return Node_Id
;
84 -- Common processing for Task_Array_Image and Task_Record_Image.
85 -- Build function body that computes image.
87 procedure Build_Task_Image_Prefix
96 -- Common processing for Task_Array_Image and Task_Record_Image.
97 -- Create local variables and assign prefix of name to result string.
99 function Build_Task_Record_Image
102 Dyn
: Boolean := False) return Node_Id
;
103 -- Build function to generate the image string for a task that is a
104 -- record component. Concatenate name of variable with that of selector.
105 -- The flag Dyn indicates whether this is called for the initialization
106 -- procedure of record with task components, or for a dynamically
107 -- created task that is assigned to a selected component.
109 function Make_CW_Equivalent_Type
111 E
: Node_Id
) return Entity_Id
;
112 -- T is a class-wide type entity, E is the initial expression node that
113 -- constrains T in case such as: " X: T := E" or "new T'(E)"
114 -- This function returns the entity of the Equivalent type and inserts
115 -- on the fly the necessary declaration such as:
117 -- type anon is record
118 -- _parent : Root_Type (T); constrained with E discriminants (if any)
119 -- Extension : String (1 .. expr to match size of E);
122 -- This record is compatible with any object of the class of T thanks
123 -- to the first field and has the same size as E thanks to the second.
125 function Make_Literal_Range
127 Literal_Typ
: Entity_Id
) return Node_Id
;
128 -- Produce a Range node whose bounds are:
129 -- Low_Bound (Literal_Type) ..
130 -- Low_Bound (Literal_Type) + (Length (Literal_Typ) - 1)
131 -- this is used for expanding declarations like X : String := "sdfgdfg";
133 -- If the index type of the target array is not integer, we generate:
134 -- Low_Bound (Literal_Type) ..
136 -- (Literal_Type'Pos (Low_Bound (Literal_Type))
137 -- + (Length (Literal_Typ) -1))
139 function Make_Non_Empty_Check
141 N
: Node_Id
) return Node_Id
;
142 -- Produce a boolean expression checking that the unidimensional array
143 -- node N is not empty.
145 function New_Class_Wide_Subtype
147 N
: Node_Id
) return Entity_Id
;
148 -- Create an implicit subtype of CW_Typ attached to node N
150 ----------------------
151 -- Adjust_Condition --
152 ----------------------
154 procedure Adjust_Condition
(N
: Node_Id
) is
161 Loc
: constant Source_Ptr
:= Sloc
(N
);
162 T
: constant Entity_Id
:= Etype
(N
);
166 -- For now, we simply ignore a call where the argument has no
167 -- type (probably case of unanalyzed condition), or has a type
168 -- that is not Boolean. This is because this is a pretty marginal
169 -- piece of functionality, and violations of these rules are
170 -- likely to be truly marginal (how much code uses Fortran Logical
171 -- as the barrier to a protected entry?) and we do not want to
172 -- blow up existing programs. We can change this to an assertion
173 -- after 3.12a is released ???
175 if No
(T
) or else not Is_Boolean_Type
(T
) then
179 -- Apply validity checking if needed
181 if Validity_Checks_On
and Validity_Check_Tests
then
185 -- Immediate return if standard boolean, the most common case,
186 -- where nothing needs to be done.
188 if Base_Type
(T
) = Standard_Boolean
then
192 -- Case of zero/non-zero semantics or non-standard enumeration
193 -- representation. In each case, we rewrite the node as:
195 -- ityp!(N) /= False'Enum_Rep
197 -- where ityp is an integer type with large enough size to hold
198 -- any value of type T.
200 if Nonzero_Is_True
(T
) or else Has_Non_Standard_Rep
(T
) then
201 if Esize
(T
) <= Esize
(Standard_Integer
) then
202 Ti
:= Standard_Integer
;
204 Ti
:= Standard_Long_Long_Integer
;
209 Left_Opnd
=> Unchecked_Convert_To
(Ti
, N
),
211 Make_Attribute_Reference
(Loc
,
212 Attribute_Name
=> Name_Enum_Rep
,
214 New_Occurrence_Of
(First_Literal
(T
), Loc
))));
215 Analyze_And_Resolve
(N
, Standard_Boolean
);
218 Rewrite
(N
, Convert_To
(Standard_Boolean
, N
));
219 Analyze_And_Resolve
(N
, Standard_Boolean
);
222 end Adjust_Condition
;
224 ------------------------
225 -- Adjust_Result_Type --
226 ------------------------
228 procedure Adjust_Result_Type
(N
: Node_Id
; T
: Entity_Id
) is
230 -- Ignore call if current type is not Standard.Boolean
232 if Etype
(N
) /= Standard_Boolean
then
236 -- If result is already of correct type, nothing to do. Note that
237 -- this will get the most common case where everything has a type
238 -- of Standard.Boolean.
240 if Base_Type
(T
) = Standard_Boolean
then
245 KP
: constant Node_Kind
:= Nkind
(Parent
(N
));
248 -- If result is to be used as a Condition in the syntax, no need
249 -- to convert it back, since if it was changed to Standard.Boolean
250 -- using Adjust_Condition, that is just fine for this usage.
252 if KP
in N_Raise_xxx_Error
or else KP
in N_Has_Condition
then
255 -- If result is an operand of another logical operation, no need
256 -- to reset its type, since Standard.Boolean is just fine, and
257 -- such operations always do Adjust_Condition on their operands.
259 elsif KP
in N_Op_Boolean
260 or else KP
in N_Short_Circuit
261 or else KP
= N_Op_Not
265 -- Otherwise we perform a conversion from the current type,
266 -- which must be Standard.Boolean, to the desired type.
270 Rewrite
(N
, Convert_To
(T
, N
));
271 Analyze_And_Resolve
(N
, T
);
275 end Adjust_Result_Type
;
277 --------------------------
278 -- Append_Freeze_Action --
279 --------------------------
281 procedure Append_Freeze_Action
(T
: Entity_Id
; N
: Node_Id
) is
285 Ensure_Freeze_Node
(T
);
286 Fnode
:= Freeze_Node
(T
);
288 if No
(Actions
(Fnode
)) then
289 Set_Actions
(Fnode
, New_List
);
292 Append
(N
, Actions
(Fnode
));
293 end Append_Freeze_Action
;
295 ---------------------------
296 -- Append_Freeze_Actions --
297 ---------------------------
299 procedure Append_Freeze_Actions
(T
: Entity_Id
; L
: List_Id
) is
300 Fnode
: constant Node_Id
:= Freeze_Node
(T
);
307 if No
(Actions
(Fnode
)) then
308 Set_Actions
(Fnode
, L
);
311 Append_List
(L
, Actions
(Fnode
));
315 end Append_Freeze_Actions
;
317 ------------------------
318 -- Build_Runtime_Call --
319 ------------------------
321 function Build_Runtime_Call
(Loc
: Source_Ptr
; RE
: RE_Id
) return Node_Id
is
323 -- If entity is not available, we can skip making the call (this avoids
324 -- junk duplicated error messages in a number of cases).
326 if not RTE_Available
(RE
) then
327 return Make_Null_Statement
(Loc
);
330 Make_Procedure_Call_Statement
(Loc
,
331 Name
=> New_Reference_To
(RTE
(RE
), Loc
));
333 end Build_Runtime_Call
;
335 ----------------------------
336 -- Build_Task_Array_Image --
337 ----------------------------
339 -- This function generates the body for a function that constructs the
340 -- image string for a task that is an array component. The function is
341 -- local to the init proc for the array type, and is called for each one
342 -- of the components. The constructed image has the form of an indexed
343 -- component, whose prefix is the outer variable of the array type.
344 -- The n-dimensional array type has known indices Index, Index2...
345 -- Id_Ref is an indexed component form created by the enclosing init proc.
346 -- Its successive indices are Val1, Val2, ... which are the loop variables
347 -- in the loops that call the individual task init proc on each component.
349 -- The generated function has the following structure:
351 -- function F return String is
352 -- Pref : string renames Task_Name;
353 -- T1 : String := Index1'Image (Val1);
355 -- Tn : String := indexn'image (Valn);
356 -- Len : Integer := T1'Length + ... + Tn'Length + n + 1;
357 -- -- Len includes commas and the end parentheses.
358 -- Res : String (1..Len);
359 -- Pos : Integer := Pref'Length;
362 -- Res (1 .. Pos) := Pref;
366 -- Res (Pos .. Pos + T1'Length - 1) := T1;
367 -- Pos := Pos + T1'Length;
371 -- Res (Pos .. Pos + Tn'Length - 1) := Tn;
377 -- Needless to say, multidimensional arrays of tasks are rare enough
378 -- that the bulkiness of this code is not really a concern.
380 function Build_Task_Array_Image
384 Dyn
: Boolean := False) return Node_Id
386 Dims
: constant Nat
:= Number_Dimensions
(A_Type
);
387 -- Number of dimensions for array of tasks
389 Temps
: array (1 .. Dims
) of Entity_Id
;
390 -- Array of temporaries to hold string for each index
396 -- Total length of generated name
399 -- Running index for substring assignments
402 -- Name of enclosing variable, prefix of resulting name
405 -- String to hold result
408 -- Value of successive indices
411 -- Expression to compute total size of string
414 -- Entity for name at one index position
416 Decls
: constant List_Id
:= New_List
;
417 Stats
: constant List_Id
:= New_List
;
420 Pref
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('P'));
422 -- For a dynamic task, the name comes from the target variable.
423 -- For a static one it is a formal of the enclosing init proc.
426 Get_Name_String
(Chars
(Entity
(Prefix
(Id_Ref
))));
428 Make_Object_Declaration
(Loc
,
429 Defining_Identifier
=> Pref
,
430 Object_Definition
=> New_Occurrence_Of
(Standard_String
, Loc
),
432 Make_String_Literal
(Loc
,
433 Strval
=> String_From_Name_Buffer
)));
437 Make_Object_Renaming_Declaration
(Loc
,
438 Defining_Identifier
=> Pref
,
439 Subtype_Mark
=> New_Occurrence_Of
(Standard_String
, Loc
),
440 Name
=> Make_Identifier
(Loc
, Name_uTask_Name
)));
443 Indx
:= First_Index
(A_Type
);
444 Val
:= First
(Expressions
(Id_Ref
));
446 for J
in 1 .. Dims
loop
447 T
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('T'));
451 Make_Object_Declaration
(Loc
,
452 Defining_Identifier
=> T
,
453 Object_Definition
=> New_Occurrence_Of
(Standard_String
, Loc
),
455 Make_Attribute_Reference
(Loc
,
456 Attribute_Name
=> Name_Image
,
458 New_Occurrence_Of
(Etype
(Indx
), Loc
),
459 Expressions
=> New_List
(
460 New_Copy_Tree
(Val
)))));
466 Sum
:= Make_Integer_Literal
(Loc
, Dims
+ 1);
472 Make_Attribute_Reference
(Loc
,
473 Attribute_Name
=> Name_Length
,
475 New_Occurrence_Of
(Pref
, Loc
),
476 Expressions
=> New_List
(Make_Integer_Literal
(Loc
, 1))));
478 for J
in 1 .. Dims
loop
483 Make_Attribute_Reference
(Loc
,
484 Attribute_Name
=> Name_Length
,
486 New_Occurrence_Of
(Temps
(J
), Loc
),
487 Expressions
=> New_List
(Make_Integer_Literal
(Loc
, 1))));
490 Build_Task_Image_Prefix
(Loc
, Len
, Res
, Pos
, Pref
, Sum
, Decls
, Stats
);
492 Set_Character_Literal_Name
(Char_Code
(Character'Pos ('(')));
495 Make_Assignment_Statement
(Loc
,
496 Name
=> Make_Indexed_Component
(Loc
,
497 Prefix
=> New_Occurrence_Of
(Res
, Loc
),
498 Expressions
=> New_List
(New_Occurrence_Of
(Pos
, Loc
))),
500 Make_Character_Literal
(Loc
,
502 Char_Literal_Value
=>
503 UI_From_Int
(Character'Pos ('(')))));
506 Make_Assignment_Statement
(Loc
,
507 Name
=> New_Occurrence_Of
(Pos
, Loc
),
510 Left_Opnd
=> New_Occurrence_Of
(Pos
, Loc
),
511 Right_Opnd
=> Make_Integer_Literal
(Loc
, 1))));
513 for J
in 1 .. Dims
loop
516 Make_Assignment_Statement
(Loc
,
517 Name
=> Make_Slice
(Loc
,
518 Prefix
=> New_Occurrence_Of
(Res
, Loc
),
521 Low_Bound
=> New_Occurrence_Of
(Pos
, Loc
),
522 High_Bound
=> Make_Op_Subtract
(Loc
,
525 Left_Opnd
=> New_Occurrence_Of
(Pos
, Loc
),
527 Make_Attribute_Reference
(Loc
,
528 Attribute_Name
=> Name_Length
,
530 New_Occurrence_Of
(Temps
(J
), Loc
),
532 New_List
(Make_Integer_Literal
(Loc
, 1)))),
533 Right_Opnd
=> Make_Integer_Literal
(Loc
, 1)))),
535 Expression
=> New_Occurrence_Of
(Temps
(J
), Loc
)));
539 Make_Assignment_Statement
(Loc
,
540 Name
=> New_Occurrence_Of
(Pos
, Loc
),
543 Left_Opnd
=> New_Occurrence_Of
(Pos
, Loc
),
545 Make_Attribute_Reference
(Loc
,
546 Attribute_Name
=> Name_Length
,
547 Prefix
=> New_Occurrence_Of
(Temps
(J
), Loc
),
549 New_List
(Make_Integer_Literal
(Loc
, 1))))));
551 Set_Character_Literal_Name
(Char_Code
(Character'Pos (',')));
554 Make_Assignment_Statement
(Loc
,
555 Name
=> Make_Indexed_Component
(Loc
,
556 Prefix
=> New_Occurrence_Of
(Res
, Loc
),
557 Expressions
=> New_List
(New_Occurrence_Of
(Pos
, Loc
))),
559 Make_Character_Literal
(Loc
,
561 Char_Literal_Value
=>
562 UI_From_Int
(Character'Pos (',')))));
565 Make_Assignment_Statement
(Loc
,
566 Name
=> New_Occurrence_Of
(Pos
, Loc
),
569 Left_Opnd
=> New_Occurrence_Of
(Pos
, Loc
),
570 Right_Opnd
=> Make_Integer_Literal
(Loc
, 1))));
574 Set_Character_Literal_Name
(Char_Code
(Character'Pos (')')));
577 Make_Assignment_Statement
(Loc
,
578 Name
=> Make_Indexed_Component
(Loc
,
579 Prefix
=> New_Occurrence_Of
(Res
, Loc
),
580 Expressions
=> New_List
(New_Occurrence_Of
(Len
, Loc
))),
582 Make_Character_Literal
(Loc
,
584 Char_Literal_Value
=>
585 UI_From_Int
(Character'Pos (')')))));
586 return Build_Task_Image_Function
(Loc
, Decls
, Stats
, Res
);
587 end Build_Task_Array_Image
;
589 ----------------------------
590 -- Build_Task_Image_Decls --
591 ----------------------------
593 function Build_Task_Image_Decls
597 In_Init_Proc
: Boolean := False) return List_Id
599 Decls
: constant List_Id
:= New_List
;
600 T_Id
: Entity_Id
:= Empty
;
602 Expr
: Node_Id
:= Empty
;
603 Fun
: Node_Id
:= Empty
;
604 Is_Dyn
: constant Boolean :=
605 Nkind
(Parent
(Id_Ref
)) = N_Assignment_Statement
607 Nkind
(Expression
(Parent
(Id_Ref
))) = N_Allocator
;
610 -- If Discard_Names or No_Implicit_Heap_Allocations are in effect,
611 -- generate a dummy declaration only.
613 if Restriction_Active
(No_Implicit_Heap_Allocations
)
614 or else Global_Discard_Names
616 T_Id
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('J'));
621 Make_Object_Declaration
(Loc
,
622 Defining_Identifier
=> T_Id
,
623 Object_Definition
=> New_Occurrence_Of
(Standard_String
, Loc
),
625 Make_String_Literal
(Loc
,
626 Strval
=> String_From_Name_Buffer
)));
629 if Nkind
(Id_Ref
) = N_Identifier
630 or else Nkind
(Id_Ref
) = N_Defining_Identifier
632 -- For a simple variable, the image of the task is built from
633 -- the name of the variable. To avoid possible conflict with
634 -- the anonymous type created for a single protected object,
635 -- add a numeric suffix.
638 Make_Defining_Identifier
(Loc
,
639 New_External_Name
(Chars
(Id_Ref
), 'T', 1));
641 Get_Name_String
(Chars
(Id_Ref
));
644 Make_String_Literal
(Loc
,
645 Strval
=> String_From_Name_Buffer
);
647 elsif Nkind
(Id_Ref
) = N_Selected_Component
then
649 Make_Defining_Identifier
(Loc
,
650 New_External_Name
(Chars
(Selector_Name
(Id_Ref
)), 'T'));
651 Fun
:= Build_Task_Record_Image
(Loc
, Id_Ref
, Is_Dyn
);
653 elsif Nkind
(Id_Ref
) = N_Indexed_Component
then
655 Make_Defining_Identifier
(Loc
,
656 New_External_Name
(Chars
(A_Type
), 'N'));
658 Fun
:= Build_Task_Array_Image
(Loc
, Id_Ref
, A_Type
, Is_Dyn
);
662 if Present
(Fun
) then
664 Expr
:= Make_Function_Call
(Loc
,
665 Name
=> New_Occurrence_Of
(Defining_Entity
(Fun
), Loc
));
667 if not In_Init_Proc
and then VM_Target
= No_VM
then
668 Set_Uses_Sec_Stack
(Defining_Entity
(Fun
));
672 Decl
:= Make_Object_Declaration
(Loc
,
673 Defining_Identifier
=> T_Id
,
674 Object_Definition
=> New_Occurrence_Of
(Standard_String
, Loc
),
675 Constant_Present
=> True,
678 Append
(Decl
, Decls
);
680 end Build_Task_Image_Decls
;
682 -------------------------------
683 -- Build_Task_Image_Function --
684 -------------------------------
686 function Build_Task_Image_Function
690 Res
: Entity_Id
) return Node_Id
696 Make_Simple_Return_Statement
(Loc
,
697 Expression
=> New_Occurrence_Of
(Res
, Loc
)));
699 Spec
:= Make_Function_Specification
(Loc
,
700 Defining_Unit_Name
=>
701 Make_Defining_Identifier
(Loc
, New_Internal_Name
('F')),
702 Result_Definition
=> New_Occurrence_Of
(Standard_String
, Loc
));
704 -- Calls to 'Image use the secondary stack, which must be cleaned
705 -- up after the task name is built.
707 return Make_Subprogram_Body
(Loc
,
708 Specification
=> Spec
,
709 Declarations
=> Decls
,
710 Handled_Statement_Sequence
=>
711 Make_Handled_Sequence_Of_Statements
(Loc
, Statements
=> Stats
));
712 end Build_Task_Image_Function
;
714 -----------------------------
715 -- Build_Task_Image_Prefix --
716 -----------------------------
718 procedure Build_Task_Image_Prefix
729 Len
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('L'));
732 Make_Object_Declaration
(Loc
,
733 Defining_Identifier
=> Len
,
734 Object_Definition
=> New_Occurrence_Of
(Standard_Integer
, Loc
),
737 Res
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('R'));
740 Make_Object_Declaration
(Loc
,
741 Defining_Identifier
=> Res
,
743 Make_Subtype_Indication
(Loc
,
744 Subtype_Mark
=> New_Occurrence_Of
(Standard_String
, Loc
),
746 Make_Index_Or_Discriminant_Constraint
(Loc
,
750 Low_Bound
=> Make_Integer_Literal
(Loc
, 1),
751 High_Bound
=> New_Occurrence_Of
(Len
, Loc
)))))));
753 Pos
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('P'));
756 Make_Object_Declaration
(Loc
,
757 Defining_Identifier
=> Pos
,
758 Object_Definition
=> New_Occurrence_Of
(Standard_Integer
, Loc
)));
760 -- Pos := Prefix'Length;
763 Make_Assignment_Statement
(Loc
,
764 Name
=> New_Occurrence_Of
(Pos
, Loc
),
766 Make_Attribute_Reference
(Loc
,
767 Attribute_Name
=> Name_Length
,
768 Prefix
=> New_Occurrence_Of
(Prefix
, Loc
),
770 New_List
(Make_Integer_Literal
(Loc
, 1)))));
772 -- Res (1 .. Pos) := Prefix;
775 Make_Assignment_Statement
(Loc
,
776 Name
=> Make_Slice
(Loc
,
777 Prefix
=> New_Occurrence_Of
(Res
, Loc
),
780 Low_Bound
=> Make_Integer_Literal
(Loc
, 1),
781 High_Bound
=> New_Occurrence_Of
(Pos
, Loc
))),
783 Expression
=> New_Occurrence_Of
(Prefix
, Loc
)));
786 Make_Assignment_Statement
(Loc
,
787 Name
=> New_Occurrence_Of
(Pos
, Loc
),
790 Left_Opnd
=> New_Occurrence_Of
(Pos
, Loc
),
791 Right_Opnd
=> Make_Integer_Literal
(Loc
, 1))));
792 end Build_Task_Image_Prefix
;
794 -----------------------------
795 -- Build_Task_Record_Image --
796 -----------------------------
798 function Build_Task_Record_Image
801 Dyn
: Boolean := False) return Node_Id
804 -- Total length of generated name
810 -- String to hold result
813 -- Name of enclosing variable, prefix of resulting name
816 -- Expression to compute total size of string
819 -- Entity for selector name
821 Decls
: constant List_Id
:= New_List
;
822 Stats
: constant List_Id
:= New_List
;
825 Pref
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('P'));
827 -- For a dynamic task, the name comes from the target variable.
828 -- For a static one it is a formal of the enclosing init proc.
831 Get_Name_String
(Chars
(Entity
(Prefix
(Id_Ref
))));
833 Make_Object_Declaration
(Loc
,
834 Defining_Identifier
=> Pref
,
835 Object_Definition
=> New_Occurrence_Of
(Standard_String
, Loc
),
837 Make_String_Literal
(Loc
,
838 Strval
=> String_From_Name_Buffer
)));
842 Make_Object_Renaming_Declaration
(Loc
,
843 Defining_Identifier
=> Pref
,
844 Subtype_Mark
=> New_Occurrence_Of
(Standard_String
, Loc
),
845 Name
=> Make_Identifier
(Loc
, Name_uTask_Name
)));
848 Sel
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('S'));
850 Get_Name_String
(Chars
(Selector_Name
(Id_Ref
)));
853 Make_Object_Declaration
(Loc
,
854 Defining_Identifier
=> Sel
,
855 Object_Definition
=> New_Occurrence_Of
(Standard_String
, Loc
),
857 Make_String_Literal
(Loc
,
858 Strval
=> String_From_Name_Buffer
)));
860 Sum
:= Make_Integer_Literal
(Loc
, Nat
(Name_Len
+ 1));
866 Make_Attribute_Reference
(Loc
,
867 Attribute_Name
=> Name_Length
,
869 New_Occurrence_Of
(Pref
, Loc
),
870 Expressions
=> New_List
(Make_Integer_Literal
(Loc
, 1))));
872 Build_Task_Image_Prefix
(Loc
, Len
, Res
, Pos
, Pref
, Sum
, Decls
, Stats
);
874 Set_Character_Literal_Name
(Char_Code
(Character'Pos ('.')));
879 Make_Assignment_Statement
(Loc
,
880 Name
=> Make_Indexed_Component
(Loc
,
881 Prefix
=> New_Occurrence_Of
(Res
, Loc
),
882 Expressions
=> New_List
(New_Occurrence_Of
(Pos
, Loc
))),
884 Make_Character_Literal
(Loc
,
886 Char_Literal_Value
=>
887 UI_From_Int
(Character'Pos ('.')))));
890 Make_Assignment_Statement
(Loc
,
891 Name
=> New_Occurrence_Of
(Pos
, Loc
),
894 Left_Opnd
=> New_Occurrence_Of
(Pos
, Loc
),
895 Right_Opnd
=> Make_Integer_Literal
(Loc
, 1))));
897 -- Res (Pos .. Len) := Selector;
900 Make_Assignment_Statement
(Loc
,
901 Name
=> Make_Slice
(Loc
,
902 Prefix
=> New_Occurrence_Of
(Res
, Loc
),
905 Low_Bound
=> New_Occurrence_Of
(Pos
, Loc
),
906 High_Bound
=> New_Occurrence_Of
(Len
, Loc
))),
907 Expression
=> New_Occurrence_Of
(Sel
, Loc
)));
909 return Build_Task_Image_Function
(Loc
, Decls
, Stats
, Res
);
910 end Build_Task_Record_Image
;
912 ----------------------------------
913 -- Component_May_Be_Bit_Aligned --
914 ----------------------------------
916 function Component_May_Be_Bit_Aligned
(Comp
: Entity_Id
) return Boolean is
917 UT
: constant Entity_Id
:= Underlying_Type
(Etype
(Comp
));
920 -- If no component clause, then everything is fine, since the back end
921 -- never bit-misaligns by default, even if there is a pragma Packed for
924 if No
(Component_Clause
(Comp
)) then
928 -- It is only array and record types that cause trouble
930 if not Is_Record_Type
(UT
)
931 and then not Is_Array_Type
(UT
)
935 -- If we know that we have a small (64 bits or less) record or small
936 -- bit-packed array, then everything is fine, since the back end can
937 -- handle these cases correctly.
939 elsif Esize
(Comp
) <= 64
940 and then (Is_Record_Type
(UT
)
941 or else Is_Bit_Packed_Array
(UT
))
945 -- Otherwise if the component is not byte aligned, we know we have the
946 -- nasty unaligned case.
948 elsif Normalized_First_Bit
(Comp
) /= Uint_0
949 or else Esize
(Comp
) mod System_Storage_Unit
/= Uint_0
953 -- If we are large and byte aligned, then OK at this level
958 end Component_May_Be_Bit_Aligned
;
960 -----------------------------------
961 -- Corresponding_Runtime_Package --
962 -----------------------------------
964 function Corresponding_Runtime_Package
(Typ
: Entity_Id
) return RTU_Id
is
965 Pkg_Id
: RTU_Id
:= RTU_Null
;
968 pragma Assert
(Is_Concurrent_Type
(Typ
));
970 if Ekind
(Typ
) in Protected_Kind
then
972 or else Has_Interrupt_Handler
(Typ
)
973 or else (Has_Attach_Handler
(Typ
)
974 and then not Restricted_Profile
)
976 -- A protected type without entries that covers an interface and
977 -- overrides the abstract routines with protected procedures is
978 -- considered equivalent to a protected type with entries in the
979 -- context of dispatching select statements. It is sufficient to
980 -- check for the presence of an interface list in the declaration
981 -- node to recognize this case.
983 or else Present
(Interface_List
(Parent
(Typ
)))
986 or else Restriction_Active
(No_Entry_Queue
) = False
987 or else Number_Entries
(Typ
) > 1
988 or else (Has_Attach_Handler
(Typ
)
989 and then not Restricted_Profile
)
991 Pkg_Id
:= System_Tasking_Protected_Objects_Entries
;
993 Pkg_Id
:= System_Tasking_Protected_Objects_Single_Entry
;
997 Pkg_Id
:= System_Tasking_Protected_Objects
;
1002 end Corresponding_Runtime_Package
;
1004 -------------------------------
1005 -- Convert_To_Actual_Subtype --
1006 -------------------------------
1008 procedure Convert_To_Actual_Subtype
(Exp
: Entity_Id
) is
1012 Act_ST
:= Get_Actual_Subtype
(Exp
);
1014 if Act_ST
= Etype
(Exp
) then
1019 Convert_To
(Act_ST
, Relocate_Node
(Exp
)));
1020 Analyze_And_Resolve
(Exp
, Act_ST
);
1022 end Convert_To_Actual_Subtype
;
1024 -----------------------------------
1025 -- Current_Sem_Unit_Declarations --
1026 -----------------------------------
1028 function Current_Sem_Unit_Declarations
return List_Id
is
1029 U
: Node_Id
:= Unit
(Cunit
(Current_Sem_Unit
));
1033 -- If the current unit is a package body, locate the visible
1034 -- declarations of the package spec.
1036 if Nkind
(U
) = N_Package_Body
then
1037 U
:= Unit
(Library_Unit
(Cunit
(Current_Sem_Unit
)));
1040 if Nkind
(U
) = N_Package_Declaration
then
1041 U
:= Specification
(U
);
1042 Decls
:= Visible_Declarations
(U
);
1046 Set_Visible_Declarations
(U
, Decls
);
1050 Decls
:= Declarations
(U
);
1054 Set_Declarations
(U
, Decls
);
1059 end Current_Sem_Unit_Declarations
;
1061 -----------------------
1062 -- Duplicate_Subexpr --
1063 -----------------------
1065 function Duplicate_Subexpr
1067 Name_Req
: Boolean := False) return Node_Id
1070 Remove_Side_Effects
(Exp
, Name_Req
);
1071 return New_Copy_Tree
(Exp
);
1072 end Duplicate_Subexpr
;
1074 ---------------------------------
1075 -- Duplicate_Subexpr_No_Checks --
1076 ---------------------------------
1078 function Duplicate_Subexpr_No_Checks
1080 Name_Req
: Boolean := False) return Node_Id
1085 Remove_Side_Effects
(Exp
, Name_Req
);
1086 New_Exp
:= New_Copy_Tree
(Exp
);
1087 Remove_Checks
(New_Exp
);
1089 end Duplicate_Subexpr_No_Checks
;
1091 -----------------------------------
1092 -- Duplicate_Subexpr_Move_Checks --
1093 -----------------------------------
1095 function Duplicate_Subexpr_Move_Checks
1097 Name_Req
: Boolean := False) return Node_Id
1102 Remove_Side_Effects
(Exp
, Name_Req
);
1103 New_Exp
:= New_Copy_Tree
(Exp
);
1104 Remove_Checks
(Exp
);
1106 end Duplicate_Subexpr_Move_Checks
;
1108 --------------------
1109 -- Ensure_Defined --
1110 --------------------
1112 procedure Ensure_Defined
(Typ
: Entity_Id
; N
: Node_Id
) is
1116 -- An itype reference must only be created if this is a local
1117 -- itype, so that gigi can elaborate it on the proper objstack.
1120 and then Scope
(Typ
) = Current_Scope
1122 IR
:= Make_Itype_Reference
(Sloc
(N
));
1123 Set_Itype
(IR
, Typ
);
1124 Insert_Action
(N
, IR
);
1128 --------------------
1129 -- Entry_Names_OK --
1130 --------------------
1132 function Entry_Names_OK
return Boolean is
1135 not Restricted_Profile
1136 and then not Global_Discard_Names
1137 and then not Restriction_Active
(No_Implicit_Heap_Allocations
)
1138 and then not Restriction_Active
(No_Local_Allocators
);
1141 ---------------------
1142 -- Evolve_And_Then --
1143 ---------------------
1145 procedure Evolve_And_Then
(Cond
: in out Node_Id
; Cond1
: Node_Id
) is
1151 Make_And_Then
(Sloc
(Cond1
),
1153 Right_Opnd
=> Cond1
);
1155 end Evolve_And_Then
;
1157 --------------------
1158 -- Evolve_Or_Else --
1159 --------------------
1161 procedure Evolve_Or_Else
(Cond
: in out Node_Id
; Cond1
: Node_Id
) is
1167 Make_Or_Else
(Sloc
(Cond1
),
1169 Right_Opnd
=> Cond1
);
1173 ------------------------------
1174 -- Expand_Subtype_From_Expr --
1175 ------------------------------
1177 -- This function is applicable for both static and dynamic allocation of
1178 -- objects which are constrained by an initial expression. Basically it
1179 -- transforms an unconstrained subtype indication into a constrained one.
1180 -- The expression may also be transformed in certain cases in order to
1181 -- avoid multiple evaluation. In the static allocation case, the general
1186 -- is transformed into
1188 -- Val : Constrained_Subtype_of_T := Maybe_Modified_Expr;
1190 -- Here are the main cases :
1192 -- <if Expr is a Slice>
1193 -- Val : T ([Index_Subtype (Expr)]) := Expr;
1195 -- <elsif Expr is a String Literal>
1196 -- Val : T (T'First .. T'First + Length (string literal) - 1) := Expr;
1198 -- <elsif Expr is Constrained>
1199 -- subtype T is Type_Of_Expr
1202 -- <elsif Expr is an entity_name>
1203 -- Val : T (constraints taken from Expr) := Expr;
1206 -- type Axxx is access all T;
1207 -- Rval : Axxx := Expr'ref;
1208 -- Val : T (constraints taken from Rval) := Rval.all;
1210 -- ??? note: when the Expression is allocated in the secondary stack
1211 -- we could use it directly instead of copying it by declaring
1212 -- Val : T (...) renames Rval.all
1214 procedure Expand_Subtype_From_Expr
1216 Unc_Type
: Entity_Id
;
1217 Subtype_Indic
: Node_Id
;
1220 Loc
: constant Source_Ptr
:= Sloc
(N
);
1221 Exp_Typ
: constant Entity_Id
:= Etype
(Exp
);
1225 -- In general we cannot build the subtype if expansion is disabled,
1226 -- because internal entities may not have been defined. However, to
1227 -- avoid some cascaded errors, we try to continue when the expression
1228 -- is an array (or string), because it is safe to compute the bounds.
1229 -- It is in fact required to do so even in a generic context, because
1230 -- there may be constants that depend on bounds of string literal.
1232 if not Expander_Active
1233 and then (No
(Etype
(Exp
))
1234 or else Base_Type
(Etype
(Exp
)) /= Standard_String
)
1239 if Nkind
(Exp
) = N_Slice
then
1241 Slice_Type
: constant Entity_Id
:= Etype
(First_Index
(Exp_Typ
));
1244 Rewrite
(Subtype_Indic
,
1245 Make_Subtype_Indication
(Loc
,
1246 Subtype_Mark
=> New_Reference_To
(Unc_Type
, Loc
),
1248 Make_Index_Or_Discriminant_Constraint
(Loc
,
1249 Constraints
=> New_List
1250 (New_Reference_To
(Slice_Type
, Loc
)))));
1252 -- This subtype indication may be used later for constraint checks
1253 -- we better make sure that if a variable was used as a bound of
1254 -- of the original slice, its value is frozen.
1256 Force_Evaluation
(Low_Bound
(Scalar_Range
(Slice_Type
)));
1257 Force_Evaluation
(High_Bound
(Scalar_Range
(Slice_Type
)));
1260 elsif Ekind
(Exp_Typ
) = E_String_Literal_Subtype
then
1261 Rewrite
(Subtype_Indic
,
1262 Make_Subtype_Indication
(Loc
,
1263 Subtype_Mark
=> New_Reference_To
(Unc_Type
, Loc
),
1265 Make_Index_Or_Discriminant_Constraint
(Loc
,
1266 Constraints
=> New_List
(
1267 Make_Literal_Range
(Loc
,
1268 Literal_Typ
=> Exp_Typ
)))));
1270 elsif Is_Constrained
(Exp_Typ
)
1271 and then not Is_Class_Wide_Type
(Unc_Type
)
1273 if Is_Itype
(Exp_Typ
) then
1275 -- Within an initialization procedure, a selected component
1276 -- denotes a component of the enclosing record, and it appears
1277 -- as an actual in a call to its own initialization procedure.
1278 -- If this component depends on the outer discriminant, we must
1279 -- generate the proper actual subtype for it.
1281 if Nkind
(Exp
) = N_Selected_Component
1282 and then Within_Init_Proc
1285 Decl
: constant Node_Id
:=
1286 Build_Actual_Subtype_Of_Component
(Exp_Typ
, Exp
);
1288 if Present
(Decl
) then
1289 Insert_Action
(N
, Decl
);
1290 T
:= Defining_Identifier
(Decl
);
1296 -- No need to generate a new one (new what???)
1304 Make_Defining_Identifier
(Loc
,
1305 Chars
=> New_Internal_Name
('T'));
1308 Make_Subtype_Declaration
(Loc
,
1309 Defining_Identifier
=> T
,
1310 Subtype_Indication
=> New_Reference_To
(Exp_Typ
, Loc
)));
1312 -- This type is marked as an itype even though it has an
1313 -- explicit declaration because otherwise it can be marked
1314 -- with Is_Generic_Actual_Type and generate spurious errors.
1315 -- (see sem_ch8.Analyze_Package_Renaming and sem_type.covers)
1318 Set_Associated_Node_For_Itype
(T
, Exp
);
1321 Rewrite
(Subtype_Indic
, New_Reference_To
(T
, Loc
));
1323 -- Nothing needs to be done for private types with unknown discriminants
1324 -- if the underlying type is not an unconstrained composite type or it
1325 -- is an unchecked union.
1327 elsif Is_Private_Type
(Unc_Type
)
1328 and then Has_Unknown_Discriminants
(Unc_Type
)
1329 and then (not Is_Composite_Type
(Underlying_Type
(Unc_Type
))
1330 or else Is_Constrained
(Underlying_Type
(Unc_Type
))
1331 or else Is_Unchecked_Union
(Underlying_Type
(Unc_Type
)))
1335 -- Case of derived type with unknown discriminants where the parent type
1336 -- also has unknown discriminants.
1338 elsif Is_Record_Type
(Unc_Type
)
1339 and then not Is_Class_Wide_Type
(Unc_Type
)
1340 and then Has_Unknown_Discriminants
(Unc_Type
)
1341 and then Has_Unknown_Discriminants
(Underlying_Type
(Unc_Type
))
1343 -- Nothing to be done if no underlying record view available
1345 if No
(Underlying_Record_View
(Unc_Type
)) then
1348 -- Otherwise use the Underlying_Record_View to create the proper
1349 -- constrained subtype for an object of a derived type with unknown
1353 Remove_Side_Effects
(Exp
);
1354 Rewrite
(Subtype_Indic
,
1355 Make_Subtype_From_Expr
(Exp
, Underlying_Record_View
(Unc_Type
)));
1358 -- Renamings of class-wide interface types require no equivalent
1359 -- constrained type declarations because we only need to reference
1360 -- the tag component associated with the interface.
1363 and then Nkind
(N
) = N_Object_Renaming_Declaration
1364 and then Is_Interface
(Unc_Type
)
1366 pragma Assert
(Is_Class_Wide_Type
(Unc_Type
));
1369 -- In Ada95, nothing to be done if the type of the expression is
1370 -- limited, because in this case the expression cannot be copied,
1371 -- and its use can only be by reference.
1373 -- In Ada2005, the context can be an object declaration whose expression
1374 -- is a function that returns in place. If the nominal subtype has
1375 -- unknown discriminants, the call still provides constraints on the
1376 -- object, and we have to create an actual subtype from it.
1378 -- If the type is class-wide, the expression is dynamically tagged and
1379 -- we do not create an actual subtype either. Ditto for an interface.
1381 elsif Is_Limited_Type
(Exp_Typ
)
1383 (Is_Class_Wide_Type
(Exp_Typ
)
1384 or else Is_Interface
(Exp_Typ
)
1385 or else not Has_Unknown_Discriminants
(Exp_Typ
)
1386 or else not Is_Composite_Type
(Unc_Type
))
1390 -- For limited objects initialized with build in place function calls,
1391 -- nothing to be done; otherwise we prematurely introduce an N_Reference
1392 -- node in the expression initializing the object, which breaks the
1393 -- circuitry that detects and adds the additional arguments to the
1396 elsif Is_Build_In_Place_Function_Call
(Exp
) then
1400 Remove_Side_Effects
(Exp
);
1401 Rewrite
(Subtype_Indic
,
1402 Make_Subtype_From_Expr
(Exp
, Unc_Type
));
1404 end Expand_Subtype_From_Expr
;
1406 --------------------
1407 -- Find_Init_Call --
1408 --------------------
1410 function Find_Init_Call
1412 Rep_Clause
: Node_Id
) return Node_Id
1414 Typ
: constant Entity_Id
:= Etype
(Var
);
1416 Init_Proc
: Entity_Id
;
1417 -- Initialization procedure for Typ
1419 function Find_Init_Call_In_List
(From
: Node_Id
) return Node_Id
;
1420 -- Look for init call for Var starting at From and scanning the
1421 -- enclosing list until Rep_Clause or the end of the list is reached.
1423 ----------------------------
1424 -- Find_Init_Call_In_List --
1425 ----------------------------
1427 function Find_Init_Call_In_List
(From
: Node_Id
) return Node_Id
is
1428 Init_Call
: Node_Id
;
1432 while Present
(Init_Call
) and then Init_Call
/= Rep_Clause
loop
1433 if Nkind
(Init_Call
) = N_Procedure_Call_Statement
1434 and then Is_Entity_Name
(Name
(Init_Call
))
1435 and then Entity
(Name
(Init_Call
)) = Init_Proc
1443 end Find_Init_Call_In_List
;
1445 Init_Call
: Node_Id
;
1447 -- Start of processing for Find_Init_Call
1450 if not Has_Non_Null_Base_Init_Proc
(Typ
) then
1451 -- No init proc for the type, so obviously no call to be found
1456 Init_Proc
:= Base_Init_Proc
(Typ
);
1458 -- First scan the list containing the declaration of Var
1460 Init_Call
:= Find_Init_Call_In_List
(From
=> Next
(Parent
(Var
)));
1462 -- If not found, also look on Var's freeze actions list, if any, since
1463 -- the init call may have been moved there (case of an address clause
1464 -- applying to Var).
1466 if No
(Init_Call
) and then Present
(Freeze_Node
(Var
)) then
1467 Init_Call
:= Find_Init_Call_In_List
1468 (First
(Actions
(Freeze_Node
(Var
))));
1474 ------------------------
1475 -- Find_Interface_ADT --
1476 ------------------------
1478 function Find_Interface_ADT
1480 Iface
: Entity_Id
) return Elmt_Id
1483 Typ
: Entity_Id
:= T
;
1486 pragma Assert
(Is_Interface
(Iface
));
1488 -- Handle private types
1490 if Has_Private_Declaration
(Typ
)
1491 and then Present
(Full_View
(Typ
))
1493 Typ
:= Full_View
(Typ
);
1496 -- Handle access types
1498 if Is_Access_Type
(Typ
) then
1499 Typ
:= Directly_Designated_Type
(Typ
);
1502 -- Handle task and protected types implementing interfaces
1504 if Is_Concurrent_Type
(Typ
) then
1505 Typ
:= Corresponding_Record_Type
(Typ
);
1509 (not Is_Class_Wide_Type
(Typ
)
1510 and then Ekind
(Typ
) /= E_Incomplete_Type
);
1512 if Is_Ancestor
(Iface
, Typ
) then
1513 return First_Elmt
(Access_Disp_Table
(Typ
));
1517 Next_Elmt
(Next_Elmt
(First_Elmt
(Access_Disp_Table
(Typ
))));
1519 and then Present
(Related_Type
(Node
(ADT
)))
1520 and then Related_Type
(Node
(ADT
)) /= Iface
1521 and then not Is_Ancestor
(Iface
, Related_Type
(Node
(ADT
)))
1526 pragma Assert
(Present
(Related_Type
(Node
(ADT
))));
1529 end Find_Interface_ADT
;
1531 ------------------------
1532 -- Find_Interface_Tag --
1533 ------------------------
1535 function Find_Interface_Tag
1537 Iface
: Entity_Id
) return Entity_Id
1540 Found
: Boolean := False;
1541 Typ
: Entity_Id
:= T
;
1543 procedure Find_Tag
(Typ
: Entity_Id
);
1544 -- Internal subprogram used to recursively climb to the ancestors
1550 procedure Find_Tag
(Typ
: Entity_Id
) is
1555 -- This routine does not handle the case in which the interface is an
1556 -- ancestor of Typ. That case is handled by the enclosing subprogram.
1558 pragma Assert
(Typ
/= Iface
);
1560 -- Climb to the root type handling private types
1562 if Present
(Full_View
(Etype
(Typ
))) then
1563 if Full_View
(Etype
(Typ
)) /= Typ
then
1564 Find_Tag
(Full_View
(Etype
(Typ
)));
1567 elsif Etype
(Typ
) /= Typ
then
1568 Find_Tag
(Etype
(Typ
));
1571 -- Traverse the list of interfaces implemented by the type
1574 and then Present
(Interfaces
(Typ
))
1575 and then not (Is_Empty_Elmt_List
(Interfaces
(Typ
)))
1577 -- Skip the tag associated with the primary table
1579 pragma Assert
(Etype
(First_Tag_Component
(Typ
)) = RTE
(RE_Tag
));
1580 AI_Tag
:= Next_Tag_Component
(First_Tag_Component
(Typ
));
1581 pragma Assert
(Present
(AI_Tag
));
1583 AI_Elmt
:= First_Elmt
(Interfaces
(Typ
));
1584 while Present
(AI_Elmt
) loop
1585 AI
:= Node
(AI_Elmt
);
1587 if AI
= Iface
or else Is_Ancestor
(Iface
, AI
) then
1592 AI_Tag
:= Next_Tag_Component
(AI_Tag
);
1593 Next_Elmt
(AI_Elmt
);
1598 -- Start of processing for Find_Interface_Tag
1601 pragma Assert
(Is_Interface
(Iface
));
1603 -- Handle access types
1605 if Is_Access_Type
(Typ
) then
1606 Typ
:= Directly_Designated_Type
(Typ
);
1609 -- Handle class-wide types
1611 if Is_Class_Wide_Type
(Typ
) then
1612 Typ
:= Root_Type
(Typ
);
1615 -- Handle private types
1617 if Has_Private_Declaration
(Typ
)
1618 and then Present
(Full_View
(Typ
))
1620 Typ
:= Full_View
(Typ
);
1623 -- Handle entities from the limited view
1625 if Ekind
(Typ
) = E_Incomplete_Type
then
1626 pragma Assert
(Present
(Non_Limited_View
(Typ
)));
1627 Typ
:= Non_Limited_View
(Typ
);
1630 -- Handle task and protected types implementing interfaces
1632 if Is_Concurrent_Type
(Typ
) then
1633 Typ
:= Corresponding_Record_Type
(Typ
);
1636 -- If the interface is an ancestor of the type, then it shared the
1637 -- primary dispatch table.
1639 if Is_Ancestor
(Iface
, Typ
) then
1640 pragma Assert
(Etype
(First_Tag_Component
(Typ
)) = RTE
(RE_Tag
));
1641 return First_Tag_Component
(Typ
);
1643 -- Otherwise we need to search for its associated tag component
1647 pragma Assert
(Found
);
1650 end Find_Interface_Tag
;
1656 function Find_Prim_Op
(T
: Entity_Id
; Name
: Name_Id
) return Entity_Id
is
1658 Typ
: Entity_Id
:= T
;
1662 if Is_Class_Wide_Type
(Typ
) then
1663 Typ
:= Root_Type
(Typ
);
1666 Typ
:= Underlying_Type
(Typ
);
1668 -- Loop through primitive operations
1670 Prim
:= First_Elmt
(Primitive_Operations
(Typ
));
1671 while Present
(Prim
) loop
1674 -- We can retrieve primitive operations by name if it is an internal
1675 -- name. For equality we must check that both of its operands have
1676 -- the same type, to avoid confusion with user-defined equalities
1677 -- than may have a non-symmetric signature.
1679 exit when Chars
(Op
) = Name
1682 or else Etype
(First_Entity
(Op
)) = Etype
(Last_Entity
(Op
)));
1686 -- Raise Program_Error if no primitive found
1689 raise Program_Error
;
1700 function Find_Prim_Op
1702 Name
: TSS_Name_Type
) return Entity_Id
1705 Typ
: Entity_Id
:= T
;
1708 if Is_Class_Wide_Type
(Typ
) then
1709 Typ
:= Root_Type
(Typ
);
1712 Typ
:= Underlying_Type
(Typ
);
1714 Prim
:= First_Elmt
(Primitive_Operations
(Typ
));
1715 while not Is_TSS
(Node
(Prim
), Name
) loop
1718 -- Raise program error if no primitive found
1721 raise Program_Error
;
1728 ----------------------------
1729 -- Find_Protection_Object --
1730 ----------------------------
1732 function Find_Protection_Object
(Scop
: Entity_Id
) return Entity_Id
is
1737 while Present
(S
) loop
1738 if (Ekind
(S
) = E_Entry
1739 or else Ekind
(S
) = E_Entry_Family
1740 or else Ekind
(S
) = E_Function
1741 or else Ekind
(S
) = E_Procedure
)
1742 and then Present
(Protection_Object
(S
))
1744 return Protection_Object
(S
);
1750 -- If we do not find a Protection object in the scope chain, then
1751 -- something has gone wrong, most likely the object was never created.
1753 raise Program_Error
;
1754 end Find_Protection_Object
;
1756 ----------------------
1757 -- Force_Evaluation --
1758 ----------------------
1760 procedure Force_Evaluation
(Exp
: Node_Id
; Name_Req
: Boolean := False) is
1762 Remove_Side_Effects
(Exp
, Name_Req
, Variable_Ref
=> True);
1763 end Force_Evaluation
;
1765 ------------------------
1766 -- Generate_Poll_Call --
1767 ------------------------
1769 procedure Generate_Poll_Call
(N
: Node_Id
) is
1771 -- No poll call if polling not active
1773 if not Polling_Required
then
1776 -- Otherwise generate require poll call
1779 Insert_Before_And_Analyze
(N
,
1780 Make_Procedure_Call_Statement
(Sloc
(N
),
1781 Name
=> New_Occurrence_Of
(RTE
(RE_Poll
), Sloc
(N
))));
1783 end Generate_Poll_Call
;
1785 ---------------------------------
1786 -- Get_Current_Value_Condition --
1787 ---------------------------------
1789 -- Note: the implementation of this procedure is very closely tied to the
1790 -- implementation of Set_Current_Value_Condition. In the Get procedure, we
1791 -- interpret Current_Value fields set by the Set procedure, so the two
1792 -- procedures need to be closely coordinated.
1794 procedure Get_Current_Value_Condition
1799 Loc
: constant Source_Ptr
:= Sloc
(Var
);
1800 Ent
: constant Entity_Id
:= Entity
(Var
);
1802 procedure Process_Current_Value_Condition
1805 -- N is an expression which holds either True (S = True) or False (S =
1806 -- False) in the condition. This procedure digs out the expression and
1807 -- if it refers to Ent, sets Op and Val appropriately.
1809 -------------------------------------
1810 -- Process_Current_Value_Condition --
1811 -------------------------------------
1813 procedure Process_Current_Value_Condition
1824 -- Deal with NOT operators, inverting sense
1826 while Nkind
(Cond
) = N_Op_Not
loop
1827 Cond
:= Right_Opnd
(Cond
);
1831 -- Deal with AND THEN and AND cases
1833 if Nkind
(Cond
) = N_And_Then
1834 or else Nkind
(Cond
) = N_Op_And
1836 -- Don't ever try to invert a condition that is of the form
1837 -- of an AND or AND THEN (since we are not doing sufficiently
1838 -- general processing to allow this).
1840 if Sens
= False then
1846 -- Recursively process AND and AND THEN branches
1848 Process_Current_Value_Condition
(Left_Opnd
(Cond
), True);
1850 if Op
/= N_Empty
then
1854 Process_Current_Value_Condition
(Right_Opnd
(Cond
), True);
1857 -- Case of relational operator
1859 elsif Nkind
(Cond
) in N_Op_Compare
then
1862 -- Invert sense of test if inverted test
1864 if Sens
= False then
1866 when N_Op_Eq
=> Op
:= N_Op_Ne
;
1867 when N_Op_Ne
=> Op
:= N_Op_Eq
;
1868 when N_Op_Lt
=> Op
:= N_Op_Ge
;
1869 when N_Op_Gt
=> Op
:= N_Op_Le
;
1870 when N_Op_Le
=> Op
:= N_Op_Gt
;
1871 when N_Op_Ge
=> Op
:= N_Op_Lt
;
1872 when others => raise Program_Error
;
1876 -- Case of entity op value
1878 if Is_Entity_Name
(Left_Opnd
(Cond
))
1879 and then Ent
= Entity
(Left_Opnd
(Cond
))
1880 and then Compile_Time_Known_Value
(Right_Opnd
(Cond
))
1882 Val
:= Right_Opnd
(Cond
);
1884 -- Case of value op entity
1886 elsif Is_Entity_Name
(Right_Opnd
(Cond
))
1887 and then Ent
= Entity
(Right_Opnd
(Cond
))
1888 and then Compile_Time_Known_Value
(Left_Opnd
(Cond
))
1890 Val
:= Left_Opnd
(Cond
);
1892 -- We are effectively swapping operands
1895 when N_Op_Eq
=> null;
1896 when N_Op_Ne
=> null;
1897 when N_Op_Lt
=> Op
:= N_Op_Gt
;
1898 when N_Op_Gt
=> Op
:= N_Op_Lt
;
1899 when N_Op_Le
=> Op
:= N_Op_Ge
;
1900 when N_Op_Ge
=> Op
:= N_Op_Le
;
1901 when others => raise Program_Error
;
1910 -- Case of Boolean variable reference, return as though the
1911 -- reference had said var = True.
1914 if Is_Entity_Name
(Cond
)
1915 and then Ent
= Entity
(Cond
)
1917 Val
:= New_Occurrence_Of
(Standard_True
, Sloc
(Cond
));
1919 if Sens
= False then
1926 end Process_Current_Value_Condition
;
1928 -- Start of processing for Get_Current_Value_Condition
1934 -- Immediate return, nothing doing, if this is not an object
1936 if Ekind
(Ent
) not in Object_Kind
then
1940 -- Otherwise examine current value
1943 CV
: constant Node_Id
:= Current_Value
(Ent
);
1948 -- If statement. Condition is known true in THEN section, known False
1949 -- in any ELSIF or ELSE part, and unknown outside the IF statement.
1951 if Nkind
(CV
) = N_If_Statement
then
1953 -- Before start of IF statement
1955 if Loc
< Sloc
(CV
) then
1958 -- After end of IF statement
1960 elsif Loc
>= Sloc
(CV
) + Text_Ptr
(UI_To_Int
(End_Span
(CV
))) then
1964 -- At this stage we know that we are within the IF statement, but
1965 -- unfortunately, the tree does not record the SLOC of the ELSE so
1966 -- we cannot use a simple SLOC comparison to distinguish between
1967 -- the then/else statements, so we have to climb the tree.
1974 while Parent
(N
) /= CV
loop
1977 -- If we fall off the top of the tree, then that's odd, but
1978 -- perhaps it could occur in some error situation, and the
1979 -- safest response is simply to assume that the outcome of
1980 -- the condition is unknown. No point in bombing during an
1981 -- attempt to optimize things.
1988 -- Now we have N pointing to a node whose parent is the IF
1989 -- statement in question, so now we can tell if we are within
1990 -- the THEN statements.
1992 if Is_List_Member
(N
)
1993 and then List_Containing
(N
) = Then_Statements
(CV
)
1997 -- If the variable reference does not come from source, we
1998 -- cannot reliably tell whether it appears in the else part.
1999 -- In particular, if it appears in generated code for a node
2000 -- that requires finalization, it may be attached to a list
2001 -- that has not been yet inserted into the code. For now,
2002 -- treat it as unknown.
2004 elsif not Comes_From_Source
(N
) then
2007 -- Otherwise we must be in ELSIF or ELSE part
2014 -- ELSIF part. Condition is known true within the referenced
2015 -- ELSIF, known False in any subsequent ELSIF or ELSE part, and
2016 -- unknown before the ELSE part or after the IF statement.
2018 elsif Nkind
(CV
) = N_Elsif_Part
then
2021 -- Before start of ELSIF part
2023 if Loc
< Sloc
(CV
) then
2026 -- After end of IF statement
2028 elsif Loc
>= Sloc
(Stm
) +
2029 Text_Ptr
(UI_To_Int
(End_Span
(Stm
)))
2034 -- Again we lack the SLOC of the ELSE, so we need to climb the
2035 -- tree to see if we are within the ELSIF part in question.
2042 while Parent
(N
) /= Stm
loop
2045 -- If we fall off the top of the tree, then that's odd, but
2046 -- perhaps it could occur in some error situation, and the
2047 -- safest response is simply to assume that the outcome of
2048 -- the condition is unknown. No point in bombing during an
2049 -- attempt to optimize things.
2056 -- Now we have N pointing to a node whose parent is the IF
2057 -- statement in question, so see if is the ELSIF part we want.
2058 -- the THEN statements.
2063 -- Otherwise we must be in subsequent ELSIF or ELSE part
2070 -- Iteration scheme of while loop. The condition is known to be
2071 -- true within the body of the loop.
2073 elsif Nkind
(CV
) = N_Iteration_Scheme
then
2075 Loop_Stmt
: constant Node_Id
:= Parent
(CV
);
2078 -- Before start of body of loop
2080 if Loc
< Sloc
(Loop_Stmt
) then
2083 -- After end of LOOP statement
2085 elsif Loc
>= Sloc
(End_Label
(Loop_Stmt
)) then
2088 -- We are within the body of the loop
2095 -- All other cases of Current_Value settings
2101 -- If we fall through here, then we have a reportable condition, Sens
2102 -- is True if the condition is true and False if it needs inverting.
2104 Process_Current_Value_Condition
(Condition
(CV
), Sens
);
2106 end Get_Current_Value_Condition
;
2108 ---------------------------------
2109 -- Has_Controlled_Coextensions --
2110 ---------------------------------
2112 function Has_Controlled_Coextensions
(Typ
: Entity_Id
) return Boolean is
2117 -- Only consider record types
2119 if Ekind
(Typ
) /= E_Record_Type
2120 and then Ekind
(Typ
) /= E_Record_Subtype
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
(Directly_Designated_Type
(D_Typ
))
2134 Is_Concurrent_Type
(Directly_Designated_Type
(D_Typ
)))
2139 Next_Discriminant
(Discr
);
2144 end Has_Controlled_Coextensions
;
2146 --------------------
2147 -- Homonym_Number --
2148 --------------------
2150 function Homonym_Number
(Subp
: Entity_Id
) return Nat
is
2156 Hom
:= Homonym
(Subp
);
2157 while Present
(Hom
) loop
2158 if Scope
(Hom
) = Scope
(Subp
) then
2162 Hom
:= Homonym
(Hom
);
2168 ------------------------------
2169 -- In_Unconditional_Context --
2170 ------------------------------
2172 function In_Unconditional_Context
(Node
: Node_Id
) return Boolean is
2177 while Present
(P
) loop
2179 when N_Subprogram_Body
=>
2182 when N_If_Statement
=>
2185 when N_Loop_Statement
=>
2188 when N_Case_Statement
=>
2197 end In_Unconditional_Context
;
2203 procedure Insert_Action
(Assoc_Node
: Node_Id
; Ins_Action
: Node_Id
) is
2205 if Present
(Ins_Action
) then
2206 Insert_Actions
(Assoc_Node
, New_List
(Ins_Action
));
2210 -- Version with check(s) suppressed
2212 procedure Insert_Action
2213 (Assoc_Node
: Node_Id
; Ins_Action
: Node_Id
; Suppress
: Check_Id
)
2216 Insert_Actions
(Assoc_Node
, New_List
(Ins_Action
), Suppress
);
2219 --------------------
2220 -- Insert_Actions --
2221 --------------------
2223 procedure Insert_Actions
(Assoc_Node
: Node_Id
; Ins_Actions
: List_Id
) is
2227 Wrapped_Node
: Node_Id
:= Empty
;
2230 if No
(Ins_Actions
) or else Is_Empty_List
(Ins_Actions
) then
2234 -- Ignore insert of actions from inside default expression (or other
2235 -- similar "spec expression") in the special spec-expression analyze
2236 -- mode. Any insertions at this point have no relevance, since we are
2237 -- only doing the analyze to freeze the types of any static expressions.
2238 -- See section "Handling of Default Expressions" in the spec of package
2239 -- Sem for further details.
2241 if In_Spec_Expression
then
2245 -- If the action derives from stuff inside a record, then the actions
2246 -- are attached to the current scope, to be inserted and analyzed on
2247 -- exit from the scope. The reason for this is that we may also
2248 -- be generating freeze actions at the same time, and they must
2249 -- eventually be elaborated in the correct order.
2251 if Is_Record_Type
(Current_Scope
)
2252 and then not Is_Frozen
(Current_Scope
)
2254 if No
(Scope_Stack
.Table
2255 (Scope_Stack
.Last
).Pending_Freeze_Actions
)
2257 Scope_Stack
.Table
(Scope_Stack
.Last
).Pending_Freeze_Actions
:=
2262 Scope_Stack
.Table
(Scope_Stack
.Last
).Pending_Freeze_Actions
);
2268 -- We now intend to climb up the tree to find the right point to
2269 -- insert the actions. We start at Assoc_Node, unless this node is
2270 -- a subexpression in which case we start with its parent. We do this
2271 -- for two reasons. First it speeds things up. Second, if Assoc_Node
2272 -- is itself one of the special nodes like N_And_Then, then we assume
2273 -- that an initial request to insert actions for such a node does not
2274 -- expect the actions to get deposited in the node for later handling
2275 -- when the node is expanded, since clearly the node is being dealt
2276 -- with by the caller. Note that in the subexpression case, N is
2277 -- always the child we came from.
2279 -- N_Raise_xxx_Error is an annoying special case, it is a statement
2280 -- if it has type Standard_Void_Type, and a subexpression otherwise.
2281 -- otherwise. Procedure attribute references are also statements.
2283 if Nkind
(Assoc_Node
) in N_Subexpr
2284 and then (Nkind
(Assoc_Node
) in N_Raise_xxx_Error
2285 or else Etype
(Assoc_Node
) /= Standard_Void_Type
)
2286 and then (Nkind
(Assoc_Node
) /= N_Attribute_Reference
2288 not Is_Procedure_Attribute_Name
2289 (Attribute_Name
(Assoc_Node
)))
2291 P
:= Assoc_Node
; -- ??? does not agree with above!
2292 N
:= Parent
(Assoc_Node
);
2294 -- Non-subexpression case. Note that N is initially Empty in this
2295 -- case (N is only guaranteed Non-Empty in the subexpr case).
2302 -- Capture root of the transient scope
2304 if Scope_Is_Transient
then
2305 Wrapped_Node
:= Node_To_Be_Wrapped
;
2309 pragma Assert
(Present
(P
));
2313 -- Case of right operand of AND THEN or OR ELSE. Put the actions
2314 -- in the Actions field of the right operand. They will be moved
2315 -- out further when the AND THEN or OR ELSE operator is expanded.
2316 -- Nothing special needs to be done for the left operand since
2317 -- in that case the actions are executed unconditionally.
2319 when N_Short_Circuit
=>
2320 if N
= Right_Opnd
(P
) then
2322 -- We are now going to either append the actions to the
2323 -- actions field of the short-circuit operation. We will
2324 -- also analyze the actions now.
2326 -- This analysis is really too early, the proper thing would
2327 -- be to just park them there now, and only analyze them if
2328 -- we find we really need them, and to it at the proper
2329 -- final insertion point. However attempting to this proved
2330 -- tricky, so for now we just kill current values before and
2331 -- after the analyze call to make sure we avoid peculiar
2332 -- optimizations from this out of order insertion.
2334 Kill_Current_Values
;
2336 if Present
(Actions
(P
)) then
2337 Insert_List_After_And_Analyze
2338 (Last
(Actions
(P
)), Ins_Actions
);
2340 Set_Actions
(P
, Ins_Actions
);
2341 Analyze_List
(Actions
(P
));
2344 Kill_Current_Values
;
2349 -- Then or Else operand of conditional expression. Add actions to
2350 -- Then_Actions or Else_Actions field as appropriate. The actions
2351 -- will be moved further out when the conditional is expanded.
2353 when N_Conditional_Expression
=>
2355 ThenX
: constant Node_Id
:= Next
(First
(Expressions
(P
)));
2356 ElseX
: constant Node_Id
:= Next
(ThenX
);
2359 -- Actions belong to the then expression, temporarily
2360 -- place them as Then_Actions of the conditional expr.
2361 -- They will be moved to the proper place later when
2362 -- the conditional expression is expanded.
2365 if Present
(Then_Actions
(P
)) then
2366 Insert_List_After_And_Analyze
2367 (Last
(Then_Actions
(P
)), Ins_Actions
);
2369 Set_Then_Actions
(P
, Ins_Actions
);
2370 Analyze_List
(Then_Actions
(P
));
2375 -- Actions belong to the else expression, temporarily
2376 -- place them as Else_Actions of the conditional expr.
2377 -- They will be moved to the proper place later when
2378 -- the conditional expression is expanded.
2380 elsif N
= ElseX
then
2381 if Present
(Else_Actions
(P
)) then
2382 Insert_List_After_And_Analyze
2383 (Last
(Else_Actions
(P
)), Ins_Actions
);
2385 Set_Else_Actions
(P
, Ins_Actions
);
2386 Analyze_List
(Else_Actions
(P
));
2391 -- Actions belong to the condition. In this case they are
2392 -- unconditionally executed, and so we can continue the
2393 -- search for the proper insert point.
2400 -- Case of appearing in the condition of a while expression or
2401 -- elsif. We insert the actions into the Condition_Actions field.
2402 -- They will be moved further out when the while loop or elsif
2405 when N_Iteration_Scheme |
2408 if N
= Condition
(P
) then
2409 if Present
(Condition_Actions
(P
)) then
2410 Insert_List_After_And_Analyze
2411 (Last
(Condition_Actions
(P
)), Ins_Actions
);
2413 Set_Condition_Actions
(P
, Ins_Actions
);
2415 -- Set the parent of the insert actions explicitly.
2416 -- This is not a syntactic field, but we need the
2417 -- parent field set, in particular so that freeze
2418 -- can understand that it is dealing with condition
2419 -- actions, and properly insert the freezing actions.
2421 Set_Parent
(Ins_Actions
, P
);
2422 Analyze_List
(Condition_Actions
(P
));
2428 -- Statements, declarations, pragmas, representation clauses
2433 N_Procedure_Call_Statement |
2434 N_Statement_Other_Than_Procedure_Call |
2440 -- Representation_Clause
2443 N_Attribute_Definition_Clause |
2444 N_Enumeration_Representation_Clause |
2445 N_Record_Representation_Clause |
2449 N_Abstract_Subprogram_Declaration |
2451 N_Exception_Declaration |
2452 N_Exception_Renaming_Declaration |
2453 N_Formal_Abstract_Subprogram_Declaration |
2454 N_Formal_Concrete_Subprogram_Declaration |
2455 N_Formal_Object_Declaration |
2456 N_Formal_Type_Declaration |
2457 N_Full_Type_Declaration |
2458 N_Function_Instantiation |
2459 N_Generic_Function_Renaming_Declaration |
2460 N_Generic_Package_Declaration |
2461 N_Generic_Package_Renaming_Declaration |
2462 N_Generic_Procedure_Renaming_Declaration |
2463 N_Generic_Subprogram_Declaration |
2464 N_Implicit_Label_Declaration |
2465 N_Incomplete_Type_Declaration |
2466 N_Number_Declaration |
2467 N_Object_Declaration |
2468 N_Object_Renaming_Declaration |
2470 N_Package_Body_Stub |
2471 N_Package_Declaration |
2472 N_Package_Instantiation |
2473 N_Package_Renaming_Declaration |
2474 N_Private_Extension_Declaration |
2475 N_Private_Type_Declaration |
2476 N_Procedure_Instantiation |
2478 N_Protected_Body_Stub |
2479 N_Protected_Type_Declaration |
2480 N_Single_Task_Declaration |
2482 N_Subprogram_Body_Stub |
2483 N_Subprogram_Declaration |
2484 N_Subprogram_Renaming_Declaration |
2485 N_Subtype_Declaration |
2488 N_Task_Type_Declaration |
2490 -- Freeze entity behaves like a declaration or statement
2494 -- Do not insert here if the item is not a list member (this
2495 -- happens for example with a triggering statement, and the
2496 -- proper approach is to insert before the entire select).
2498 if not Is_List_Member
(P
) then
2501 -- Do not insert if parent of P is an N_Component_Association
2502 -- node (i.e. we are in the context of an N_Aggregate or
2503 -- N_Extension_Aggregate node. In this case we want to insert
2504 -- before the entire aggregate.
2506 elsif Nkind
(Parent
(P
)) = N_Component_Association
then
2509 -- Do not insert if the parent of P is either an N_Variant
2510 -- node or an N_Record_Definition node, meaning in either
2511 -- case that P is a member of a component list, and that
2512 -- therefore the actions should be inserted outside the
2513 -- complete record declaration.
2515 elsif Nkind
(Parent
(P
)) = N_Variant
2516 or else Nkind
(Parent
(P
)) = N_Record_Definition
2520 -- Do not insert freeze nodes within the loop generated for
2521 -- an aggregate, because they may be elaborated too late for
2522 -- subsequent use in the back end: within a package spec the
2523 -- loop is part of the elaboration procedure and is only
2524 -- elaborated during the second pass.
2525 -- If the loop comes from source, or the entity is local to
2526 -- the loop itself it must remain within.
2528 elsif Nkind
(Parent
(P
)) = N_Loop_Statement
2529 and then not Comes_From_Source
(Parent
(P
))
2530 and then Nkind
(First
(Ins_Actions
)) = N_Freeze_Entity
2532 Scope
(Entity
(First
(Ins_Actions
))) /= Current_Scope
2536 -- Otherwise we can go ahead and do the insertion
2538 elsif P
= Wrapped_Node
then
2539 Store_Before_Actions_In_Scope
(Ins_Actions
);
2543 Insert_List_Before_And_Analyze
(P
, Ins_Actions
);
2547 -- A special case, N_Raise_xxx_Error can act either as a
2548 -- statement or a subexpression. We tell the difference
2549 -- by looking at the Etype. It is set to Standard_Void_Type
2550 -- in the statement case.
2553 N_Raise_xxx_Error
=>
2554 if Etype
(P
) = Standard_Void_Type
then
2555 if P
= Wrapped_Node
then
2556 Store_Before_Actions_In_Scope
(Ins_Actions
);
2558 Insert_List_Before_And_Analyze
(P
, Ins_Actions
);
2563 -- In the subexpression case, keep climbing
2569 -- If a component association appears within a loop created for
2570 -- an array aggregate, attach the actions to the association so
2571 -- they can be subsequently inserted within the loop. For other
2572 -- component associations insert outside of the aggregate. For
2573 -- an association that will generate a loop, its Loop_Actions
2574 -- attribute is already initialized (see exp_aggr.adb).
2576 -- The list of loop_actions can in turn generate additional ones,
2577 -- that are inserted before the associated node. If the associated
2578 -- node is outside the aggregate, the new actions are collected
2579 -- at the end of the loop actions, to respect the order in which
2580 -- they are to be elaborated.
2583 N_Component_Association
=>
2584 if Nkind
(Parent
(P
)) = N_Aggregate
2585 and then Present
(Loop_Actions
(P
))
2587 if Is_Empty_List
(Loop_Actions
(P
)) then
2588 Set_Loop_Actions
(P
, Ins_Actions
);
2589 Analyze_List
(Ins_Actions
);
2596 -- Check whether these actions were generated
2597 -- by a declaration that is part of the loop_
2598 -- actions for the component_association.
2601 while Present
(Decl
) loop
2602 exit when Parent
(Decl
) = P
2603 and then Is_List_Member
(Decl
)
2605 List_Containing
(Decl
) = Loop_Actions
(P
);
2606 Decl
:= Parent
(Decl
);
2609 if Present
(Decl
) then
2610 Insert_List_Before_And_Analyze
2611 (Decl
, Ins_Actions
);
2613 Insert_List_After_And_Analyze
2614 (Last
(Loop_Actions
(P
)), Ins_Actions
);
2625 -- Another special case, an attribute denoting a procedure call
2628 N_Attribute_Reference
=>
2629 if Is_Procedure_Attribute_Name
(Attribute_Name
(P
)) then
2630 if P
= Wrapped_Node
then
2631 Store_Before_Actions_In_Scope
(Ins_Actions
);
2633 Insert_List_Before_And_Analyze
(P
, Ins_Actions
);
2638 -- In the subexpression case, keep climbing
2644 -- For all other node types, keep climbing tree
2648 N_Accept_Alternative |
2649 N_Access_Definition |
2650 N_Access_Function_Definition |
2651 N_Access_Procedure_Definition |
2652 N_Access_To_Object_Definition |
2655 N_Case_Statement_Alternative |
2656 N_Character_Literal |
2657 N_Compilation_Unit |
2658 N_Compilation_Unit_Aux |
2659 N_Component_Clause |
2660 N_Component_Declaration |
2661 N_Component_Definition |
2663 N_Constrained_Array_Definition |
2664 N_Decimal_Fixed_Point_Definition |
2665 N_Defining_Character_Literal |
2666 N_Defining_Identifier |
2667 N_Defining_Operator_Symbol |
2668 N_Defining_Program_Unit_Name |
2669 N_Delay_Alternative |
2670 N_Delta_Constraint |
2671 N_Derived_Type_Definition |
2673 N_Digits_Constraint |
2674 N_Discriminant_Association |
2675 N_Discriminant_Specification |
2677 N_Entry_Body_Formal_Part |
2678 N_Entry_Call_Alternative |
2679 N_Entry_Declaration |
2680 N_Entry_Index_Specification |
2681 N_Enumeration_Type_Definition |
2683 N_Exception_Handler |
2685 N_Explicit_Dereference |
2686 N_Extension_Aggregate |
2687 N_Floating_Point_Definition |
2688 N_Formal_Decimal_Fixed_Point_Definition |
2689 N_Formal_Derived_Type_Definition |
2690 N_Formal_Discrete_Type_Definition |
2691 N_Formal_Floating_Point_Definition |
2692 N_Formal_Modular_Type_Definition |
2693 N_Formal_Ordinary_Fixed_Point_Definition |
2694 N_Formal_Package_Declaration |
2695 N_Formal_Private_Type_Definition |
2696 N_Formal_Signed_Integer_Type_Definition |
2698 N_Function_Specification |
2699 N_Generic_Association |
2700 N_Handled_Sequence_Of_Statements |
2703 N_Index_Or_Discriminant_Constraint |
2704 N_Indexed_Component |
2708 N_Loop_Parameter_Specification |
2710 N_Modular_Type_Definition |
2736 N_Op_Shift_Right_Arithmetic |
2740 N_Ordinary_Fixed_Point_Definition |
2742 N_Package_Specification |
2743 N_Parameter_Association |
2744 N_Parameter_Specification |
2745 N_Pop_Constraint_Error_Label |
2746 N_Pop_Program_Error_Label |
2747 N_Pop_Storage_Error_Label |
2748 N_Pragma_Argument_Association |
2749 N_Procedure_Specification |
2750 N_Protected_Definition |
2751 N_Push_Constraint_Error_Label |
2752 N_Push_Program_Error_Label |
2753 N_Push_Storage_Error_Label |
2754 N_Qualified_Expression |
2756 N_Range_Constraint |
2758 N_Real_Range_Specification |
2759 N_Record_Definition |
2761 N_SCIL_Dispatch_Table_Object_Init |
2762 N_SCIL_Dispatch_Table_Tag_Init |
2763 N_SCIL_Dispatching_Call |
2764 N_SCIL_Membership_Test |
2766 N_Selected_Component |
2767 N_Signed_Integer_Type_Definition |
2768 N_Single_Protected_Declaration |
2772 N_Subtype_Indication |
2775 N_Terminate_Alternative |
2776 N_Triggering_Alternative |
2778 N_Unchecked_Expression |
2779 N_Unchecked_Type_Conversion |
2780 N_Unconstrained_Array_Definition |
2783 N_Use_Package_Clause |
2787 N_Validate_Unchecked_Conversion |
2794 -- Make sure that inserted actions stay in the transient scope
2796 if P
= Wrapped_Node
then
2797 Store_Before_Actions_In_Scope
(Ins_Actions
);
2801 -- If we fall through above tests, keep climbing tree
2805 if Nkind
(Parent
(N
)) = N_Subunit
then
2807 -- This is the proper body corresponding to a stub. Insertion
2808 -- must be done at the point of the stub, which is in the decla-
2809 -- rative part of the parent unit.
2811 P
:= Corresponding_Stub
(Parent
(N
));
2819 -- Version with check(s) suppressed
2821 procedure Insert_Actions
2822 (Assoc_Node
: Node_Id
;
2823 Ins_Actions
: List_Id
;
2824 Suppress
: Check_Id
)
2827 if Suppress
= All_Checks
then
2829 Svg
: constant Suppress_Array
:= Scope_Suppress
;
2831 Scope_Suppress
:= (others => True);
2832 Insert_Actions
(Assoc_Node
, Ins_Actions
);
2833 Scope_Suppress
:= Svg
;
2838 Svg
: constant Boolean := Scope_Suppress
(Suppress
);
2840 Scope_Suppress
(Suppress
) := True;
2841 Insert_Actions
(Assoc_Node
, Ins_Actions
);
2842 Scope_Suppress
(Suppress
) := Svg
;
2847 --------------------------
2848 -- Insert_Actions_After --
2849 --------------------------
2851 procedure Insert_Actions_After
2852 (Assoc_Node
: Node_Id
;
2853 Ins_Actions
: List_Id
)
2856 if Scope_Is_Transient
2857 and then Assoc_Node
= Node_To_Be_Wrapped
2859 Store_After_Actions_In_Scope
(Ins_Actions
);
2861 Insert_List_After_And_Analyze
(Assoc_Node
, Ins_Actions
);
2863 end Insert_Actions_After
;
2865 ---------------------------------
2866 -- Insert_Library_Level_Action --
2867 ---------------------------------
2869 procedure Insert_Library_Level_Action
(N
: Node_Id
) is
2870 Aux
: constant Node_Id
:= Aux_Decls_Node
(Cunit
(Main_Unit
));
2873 Push_Scope
(Cunit_Entity
(Main_Unit
));
2874 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2876 if No
(Actions
(Aux
)) then
2877 Set_Actions
(Aux
, New_List
(N
));
2879 Append
(N
, Actions
(Aux
));
2884 end Insert_Library_Level_Action
;
2886 ----------------------------------
2887 -- Insert_Library_Level_Actions --
2888 ----------------------------------
2890 procedure Insert_Library_Level_Actions
(L
: List_Id
) is
2891 Aux
: constant Node_Id
:= Aux_Decls_Node
(Cunit
(Main_Unit
));
2894 if Is_Non_Empty_List
(L
) then
2895 Push_Scope
(Cunit_Entity
(Main_Unit
));
2896 -- ??? should this be Current_Sem_Unit instead of Main_Unit?
2898 if No
(Actions
(Aux
)) then
2899 Set_Actions
(Aux
, L
);
2902 Insert_List_After_And_Analyze
(Last
(Actions
(Aux
)), L
);
2907 end Insert_Library_Level_Actions
;
2909 ----------------------
2910 -- Inside_Init_Proc --
2911 ----------------------
2913 function Inside_Init_Proc
return Boolean is
2919 and then S
/= Standard_Standard
2921 if Is_Init_Proc
(S
) then
2929 end Inside_Init_Proc
;
2931 ----------------------------
2932 -- Is_All_Null_Statements --
2933 ----------------------------
2935 function Is_All_Null_Statements
(L
: List_Id
) return Boolean is
2940 while Present
(Stm
) loop
2941 if Nkind
(Stm
) /= N_Null_Statement
then
2949 end Is_All_Null_Statements
;
2951 ---------------------------------
2952 -- Is_Fully_Repped_Tagged_Type --
2953 ---------------------------------
2955 function Is_Fully_Repped_Tagged_Type
(T
: Entity_Id
) return Boolean is
2956 U
: constant Entity_Id
:= Underlying_Type
(T
);
2960 if No
(U
) or else not Is_Tagged_Type
(U
) then
2962 elsif Has_Discriminants
(U
) then
2964 elsif not Has_Specified_Layout
(U
) then
2968 -- Here we have a tagged type, see if it has any unlayed out fields
2969 -- other than a possible tag and parent fields. If so, we return False.
2971 Comp
:= First_Component
(U
);
2972 while Present
(Comp
) loop
2973 if not Is_Tag
(Comp
)
2974 and then Chars
(Comp
) /= Name_uParent
2975 and then No
(Component_Clause
(Comp
))
2979 Next_Component
(Comp
);
2983 -- All components are layed out
2986 end Is_Fully_Repped_Tagged_Type
;
2988 ----------------------------------
2989 -- Is_Library_Level_Tagged_Type --
2990 ----------------------------------
2992 function Is_Library_Level_Tagged_Type
(Typ
: Entity_Id
) return Boolean is
2994 return Is_Tagged_Type
(Typ
)
2995 and then Is_Library_Level_Entity
(Typ
);
2996 end Is_Library_Level_Tagged_Type
;
2998 ----------------------------------
2999 -- Is_Possibly_Unaligned_Object --
3000 ----------------------------------
3002 function Is_Possibly_Unaligned_Object
(N
: Node_Id
) return Boolean is
3003 T
: constant Entity_Id
:= Etype
(N
);
3006 -- If renamed object, apply test to underlying object
3008 if Is_Entity_Name
(N
)
3009 and then Is_Object
(Entity
(N
))
3010 and then Present
(Renamed_Object
(Entity
(N
)))
3012 return Is_Possibly_Unaligned_Object
(Renamed_Object
(Entity
(N
)));
3015 -- Tagged and controlled types and aliased types are always aligned,
3016 -- as are concurrent types.
3019 or else Has_Controlled_Component
(T
)
3020 or else Is_Concurrent_Type
(T
)
3021 or else Is_Tagged_Type
(T
)
3022 or else Is_Controlled
(T
)
3027 -- If this is an element of a packed array, may be unaligned
3029 if Is_Ref_To_Bit_Packed_Array
(N
) then
3033 -- Case of component reference
3035 if Nkind
(N
) = N_Selected_Component
then
3037 P
: constant Node_Id
:= Prefix
(N
);
3038 C
: constant Entity_Id
:= Entity
(Selector_Name
(N
));
3043 -- If component reference is for an array with non-static bounds,
3044 -- then it is always aligned: we can only process unaligned
3045 -- arrays with static bounds (more accurately bounds known at
3048 if Is_Array_Type
(T
)
3049 and then not Compile_Time_Known_Bounds
(T
)
3054 -- If component is aliased, it is definitely properly aligned
3056 if Is_Aliased
(C
) then
3060 -- If component is for a type implemented as a scalar, and the
3061 -- record is packed, and the component is other than the first
3062 -- component of the record, then the component may be unaligned.
3064 if Is_Packed
(Etype
(P
))
3065 and then Represented_As_Scalar
(Etype
(C
))
3066 and then First_Entity
(Scope
(C
)) /= C
3071 -- Compute maximum possible alignment for T
3073 -- If alignment is known, then that settles things
3075 if Known_Alignment
(T
) then
3076 M
:= UI_To_Int
(Alignment
(T
));
3078 -- If alignment is not known, tentatively set max alignment
3081 M
:= Ttypes
.Maximum_Alignment
;
3083 -- We can reduce this if the Esize is known since the default
3084 -- alignment will never be more than the smallest power of 2
3085 -- that does not exceed this Esize value.
3087 if Known_Esize
(T
) then
3088 S
:= UI_To_Int
(Esize
(T
));
3090 while (M
/ 2) >= S
loop
3096 -- If the component reference is for a record that has a specified
3097 -- alignment, and we either know it is too small, or cannot tell,
3098 -- then the component may be unaligned
3100 if Known_Alignment
(Etype
(P
))
3101 and then Alignment
(Etype
(P
)) < Ttypes
.Maximum_Alignment
3102 and then M
> Alignment
(Etype
(P
))
3107 -- Case of component clause present which may specify an
3108 -- unaligned position.
3110 if Present
(Component_Clause
(C
)) then
3112 -- Otherwise we can do a test to make sure that the actual
3113 -- start position in the record, and the length, are both
3114 -- consistent with the required alignment. If not, we know
3115 -- that we are unaligned.
3118 Align_In_Bits
: constant Nat
:= M
* System_Storage_Unit
;
3120 if Component_Bit_Offset
(C
) mod Align_In_Bits
/= 0
3121 or else Esize
(C
) mod Align_In_Bits
/= 0
3128 -- Otherwise, for a component reference, test prefix
3130 return Is_Possibly_Unaligned_Object
(P
);
3133 -- If not a component reference, must be aligned
3138 end Is_Possibly_Unaligned_Object
;
3140 ---------------------------------
3141 -- Is_Possibly_Unaligned_Slice --
3142 ---------------------------------
3144 function Is_Possibly_Unaligned_Slice
(N
: Node_Id
) return Boolean is
3146 -- Go to renamed object
3148 if Is_Entity_Name
(N
)
3149 and then Is_Object
(Entity
(N
))
3150 and then Present
(Renamed_Object
(Entity
(N
)))
3152 return Is_Possibly_Unaligned_Slice
(Renamed_Object
(Entity
(N
)));
3155 -- The reference must be a slice
3157 if Nkind
(N
) /= N_Slice
then
3161 -- Always assume the worst for a nested record component with a
3162 -- component clause, which gigi/gcc does not appear to handle well.
3163 -- It is not clear why this special test is needed at all ???
3165 if Nkind
(Prefix
(N
)) = N_Selected_Component
3166 and then Nkind
(Prefix
(Prefix
(N
))) = N_Selected_Component
3168 Present
(Component_Clause
(Entity
(Selector_Name
(Prefix
(N
)))))
3173 -- We only need to worry if the target has strict alignment
3175 if not Target_Strict_Alignment
then
3179 -- If it is a slice, then look at the array type being sliced
3182 Sarr
: constant Node_Id
:= Prefix
(N
);
3183 -- Prefix of the slice, i.e. the array being sliced
3185 Styp
: constant Entity_Id
:= Etype
(Prefix
(N
));
3186 -- Type of the array being sliced
3192 -- The problems arise if the array object that is being sliced
3193 -- is a component of a record or array, and we cannot guarantee
3194 -- the alignment of the array within its containing object.
3196 -- To investigate this, we look at successive prefixes to see
3197 -- if we have a worrisome indexed or selected component.
3201 -- Case of array is part of an indexed component reference
3203 if Nkind
(Pref
) = N_Indexed_Component
then
3204 Ptyp
:= Etype
(Prefix
(Pref
));
3206 -- The only problematic case is when the array is packed,
3207 -- in which case we really know nothing about the alignment
3208 -- of individual components.
3210 if Is_Bit_Packed_Array
(Ptyp
) then
3214 -- Case of array is part of a selected component reference
3216 elsif Nkind
(Pref
) = N_Selected_Component
then
3217 Ptyp
:= Etype
(Prefix
(Pref
));
3219 -- We are definitely in trouble if the record in question
3220 -- has an alignment, and either we know this alignment is
3221 -- inconsistent with the alignment of the slice, or we
3222 -- don't know what the alignment of the slice should be.
3224 if Known_Alignment
(Ptyp
)
3225 and then (Unknown_Alignment
(Styp
)
3226 or else Alignment
(Styp
) > Alignment
(Ptyp
))
3231 -- We are in potential trouble if the record type is packed.
3232 -- We could special case when we know that the array is the
3233 -- first component, but that's not such a simple case ???
3235 if Is_Packed
(Ptyp
) then
3239 -- We are in trouble if there is a component clause, and
3240 -- either we do not know the alignment of the slice, or
3241 -- the alignment of the slice is inconsistent with the
3242 -- bit position specified by the component clause.
3245 Field
: constant Entity_Id
:= Entity
(Selector_Name
(Pref
));
3247 if Present
(Component_Clause
(Field
))
3249 (Unknown_Alignment
(Styp
)
3251 (Component_Bit_Offset
(Field
) mod
3252 (System_Storage_Unit
* Alignment
(Styp
))) /= 0)
3258 -- For cases other than selected or indexed components we
3259 -- know we are OK, since no issues arise over alignment.
3265 -- We processed an indexed component or selected component
3266 -- reference that looked safe, so keep checking prefixes.
3268 Pref
:= Prefix
(Pref
);
3271 end Is_Possibly_Unaligned_Slice
;
3273 --------------------------------
3274 -- Is_Ref_To_Bit_Packed_Array --
3275 --------------------------------
3277 function Is_Ref_To_Bit_Packed_Array
(N
: Node_Id
) return Boolean is
3282 if Is_Entity_Name
(N
)
3283 and then Is_Object
(Entity
(N
))
3284 and then Present
(Renamed_Object
(Entity
(N
)))
3286 return Is_Ref_To_Bit_Packed_Array
(Renamed_Object
(Entity
(N
)));
3289 if Nkind
(N
) = N_Indexed_Component
3291 Nkind
(N
) = N_Selected_Component
3293 if Is_Bit_Packed_Array
(Etype
(Prefix
(N
))) then
3296 Result
:= Is_Ref_To_Bit_Packed_Array
(Prefix
(N
));
3299 if Result
and then Nkind
(N
) = N_Indexed_Component
then
3300 Expr
:= First
(Expressions
(N
));
3301 while Present
(Expr
) loop
3302 Force_Evaluation
(Expr
);
3312 end Is_Ref_To_Bit_Packed_Array
;
3314 --------------------------------
3315 -- Is_Ref_To_Bit_Packed_Slice --
3316 --------------------------------
3318 function Is_Ref_To_Bit_Packed_Slice
(N
: Node_Id
) return Boolean is
3320 if Nkind
(N
) = N_Type_Conversion
then
3321 return Is_Ref_To_Bit_Packed_Slice
(Expression
(N
));
3323 elsif Is_Entity_Name
(N
)
3324 and then Is_Object
(Entity
(N
))
3325 and then Present
(Renamed_Object
(Entity
(N
)))
3327 return Is_Ref_To_Bit_Packed_Slice
(Renamed_Object
(Entity
(N
)));
3329 elsif Nkind
(N
) = N_Slice
3330 and then Is_Bit_Packed_Array
(Etype
(Prefix
(N
)))
3334 elsif Nkind
(N
) = N_Indexed_Component
3336 Nkind
(N
) = N_Selected_Component
3338 return Is_Ref_To_Bit_Packed_Slice
(Prefix
(N
));
3343 end Is_Ref_To_Bit_Packed_Slice
;
3345 -----------------------
3346 -- Is_Renamed_Object --
3347 -----------------------
3349 function Is_Renamed_Object
(N
: Node_Id
) return Boolean is
3350 Pnod
: constant Node_Id
:= Parent
(N
);
3351 Kind
: constant Node_Kind
:= Nkind
(Pnod
);
3353 if Kind
= N_Object_Renaming_Declaration
then
3355 elsif Nkind_In
(Kind
, N_Indexed_Component
, N_Selected_Component
) then
3356 return Is_Renamed_Object
(Pnod
);
3360 end Is_Renamed_Object
;
3362 ----------------------------
3363 -- Is_Untagged_Derivation --
3364 ----------------------------
3366 function Is_Untagged_Derivation
(T
: Entity_Id
) return Boolean is
3368 return (not Is_Tagged_Type
(T
) and then Is_Derived_Type
(T
))
3370 (Is_Private_Type
(T
) and then Present
(Full_View
(T
))
3371 and then not Is_Tagged_Type
(Full_View
(T
))
3372 and then Is_Derived_Type
(Full_View
(T
))
3373 and then Etype
(Full_View
(T
)) /= T
);
3374 end Is_Untagged_Derivation
;
3376 ---------------------------
3377 -- Is_Volatile_Reference --
3378 ---------------------------
3380 function Is_Volatile_Reference
(N
: Node_Id
) return Boolean is
3382 if Nkind
(N
) in N_Has_Etype
3383 and then Present
(Etype
(N
))
3384 and then Treat_As_Volatile
(Etype
(N
))
3388 elsif Is_Entity_Name
(N
) then
3389 return Treat_As_Volatile
(Entity
(N
));
3391 elsif Nkind
(N
) = N_Slice
then
3392 return Is_Volatile_Reference
(Prefix
(N
));
3394 elsif Nkind_In
(N
, N_Indexed_Component
, N_Selected_Component
) then
3395 if (Is_Entity_Name
(Prefix
(N
))
3396 and then Has_Volatile_Components
(Entity
(Prefix
(N
))))
3397 or else (Present
(Etype
(Prefix
(N
)))
3398 and then Has_Volatile_Components
(Etype
(Prefix
(N
))))
3402 return Is_Volatile_Reference
(Prefix
(N
));
3408 end Is_Volatile_Reference
;
3410 --------------------
3411 -- Kill_Dead_Code --
3412 --------------------
3414 procedure Kill_Dead_Code
(N
: Node_Id
; Warn
: Boolean := False) is
3415 W
: Boolean := Warn
;
3416 -- Set False if warnings suppressed
3420 Remove_Warning_Messages
(N
);
3422 -- Generate warning if appropriate
3426 -- We suppress the warning if this code is under control of an
3427 -- if statement, whose condition is a simple identifier, and
3428 -- either we are in an instance, or warnings off is set for this
3429 -- identifier. The reason for killing it in the instance case is
3430 -- that it is common and reasonable for code to be deleted in
3431 -- instances for various reasons.
3433 if Nkind
(Parent
(N
)) = N_If_Statement
then
3435 C
: constant Node_Id
:= Condition
(Parent
(N
));
3437 if Nkind
(C
) = N_Identifier
3440 or else (Present
(Entity
(C
))
3441 and then Has_Warnings_Off
(Entity
(C
))))
3448 -- Generate warning if not suppressed
3452 ("?this code can never be executed and has been deleted!", N
);
3456 -- Recurse into block statements and bodies to process declarations
3459 if Nkind
(N
) = N_Block_Statement
3460 or else Nkind
(N
) = N_Subprogram_Body
3461 or else Nkind
(N
) = N_Package_Body
3463 Kill_Dead_Code
(Declarations
(N
), False);
3464 Kill_Dead_Code
(Statements
(Handled_Statement_Sequence
(N
)));
3466 if Nkind
(N
) = N_Subprogram_Body
then
3467 Set_Is_Eliminated
(Defining_Entity
(N
));
3470 elsif Nkind
(N
) = N_Package_Declaration
then
3471 Kill_Dead_Code
(Visible_Declarations
(Specification
(N
)));
3472 Kill_Dead_Code
(Private_Declarations
(Specification
(N
)));
3474 -- ??? After this point, Delete_Tree has been called on all
3475 -- declarations in Specification (N), so references to
3476 -- entities therein look suspicious.
3479 E
: Entity_Id
:= First_Entity
(Defining_Entity
(N
));
3481 while Present
(E
) loop
3482 if Ekind
(E
) = E_Operator
then
3483 Set_Is_Eliminated
(E
);
3490 -- Recurse into composite statement to kill individual statements,
3491 -- in particular instantiations.
3493 elsif Nkind
(N
) = N_If_Statement
then
3494 Kill_Dead_Code
(Then_Statements
(N
));
3495 Kill_Dead_Code
(Elsif_Parts
(N
));
3496 Kill_Dead_Code
(Else_Statements
(N
));
3498 elsif Nkind
(N
) = N_Loop_Statement
then
3499 Kill_Dead_Code
(Statements
(N
));
3501 elsif Nkind
(N
) = N_Case_Statement
then
3505 Alt
:= First
(Alternatives
(N
));
3506 while Present
(Alt
) loop
3507 Kill_Dead_Code
(Statements
(Alt
));
3512 elsif Nkind
(N
) = N_Case_Statement_Alternative
then
3513 Kill_Dead_Code
(Statements
(N
));
3515 -- Deal with dead instances caused by deleting instantiations
3517 elsif Nkind
(N
) in N_Generic_Instantiation
then
3518 Remove_Dead_Instance
(N
);
3523 -- Case where argument is a list of nodes to be killed
3525 procedure Kill_Dead_Code
(L
: List_Id
; Warn
: Boolean := False) is
3530 if Is_Non_Empty_List
(L
) then
3532 while Present
(N
) loop
3533 Kill_Dead_Code
(N
, W
);
3540 ------------------------
3541 -- Known_Non_Negative --
3542 ------------------------
3544 function Known_Non_Negative
(Opnd
: Node_Id
) return Boolean is
3546 if Is_OK_Static_Expression
(Opnd
)
3547 and then Expr_Value
(Opnd
) >= 0
3553 Lo
: constant Node_Id
:= Type_Low_Bound
(Etype
(Opnd
));
3557 Is_OK_Static_Expression
(Lo
) and then Expr_Value
(Lo
) >= 0;
3560 end Known_Non_Negative
;
3562 --------------------
3563 -- Known_Non_Null --
3564 --------------------
3566 function Known_Non_Null
(N
: Node_Id
) return Boolean is
3568 -- Checks for case where N is an entity reference
3570 if Is_Entity_Name
(N
) and then Present
(Entity
(N
)) then
3572 E
: constant Entity_Id
:= Entity
(N
);
3577 -- First check if we are in decisive conditional
3579 Get_Current_Value_Condition
(N
, Op
, Val
);
3581 if Known_Null
(Val
) then
3582 if Op
= N_Op_Eq
then
3584 elsif Op
= N_Op_Ne
then
3589 -- If OK to do replacement, test Is_Known_Non_Null flag
3591 if OK_To_Do_Constant_Replacement
(E
) then
3592 return Is_Known_Non_Null
(E
);
3594 -- Otherwise if not safe to do replacement, then say so
3601 -- True if access attribute
3603 elsif Nkind
(N
) = N_Attribute_Reference
3604 and then (Attribute_Name
(N
) = Name_Access
3606 Attribute_Name
(N
) = Name_Unchecked_Access
3608 Attribute_Name
(N
) = Name_Unrestricted_Access
)
3612 -- True if allocator
3614 elsif Nkind
(N
) = N_Allocator
then
3617 -- For a conversion, true if expression is known non-null
3619 elsif Nkind
(N
) = N_Type_Conversion
then
3620 return Known_Non_Null
(Expression
(N
));
3622 -- Above are all cases where the value could be determined to be
3623 -- non-null. In all other cases, we don't know, so return False.
3634 function Known_Null
(N
: Node_Id
) return Boolean is
3636 -- Checks for case where N is an entity reference
3638 if Is_Entity_Name
(N
) and then Present
(Entity
(N
)) then
3640 E
: constant Entity_Id
:= Entity
(N
);
3645 -- Constant null value is for sure null
3647 if Ekind
(E
) = E_Constant
3648 and then Known_Null
(Constant_Value
(E
))
3653 -- First check if we are in decisive conditional
3655 Get_Current_Value_Condition
(N
, Op
, Val
);
3657 if Known_Null
(Val
) then
3658 if Op
= N_Op_Eq
then
3660 elsif Op
= N_Op_Ne
then
3665 -- If OK to do replacement, test Is_Known_Null flag
3667 if OK_To_Do_Constant_Replacement
(E
) then
3668 return Is_Known_Null
(E
);
3670 -- Otherwise if not safe to do replacement, then say so
3677 -- True if explicit reference to null
3679 elsif Nkind
(N
) = N_Null
then
3682 -- For a conversion, true if expression is known null
3684 elsif Nkind
(N
) = N_Type_Conversion
then
3685 return Known_Null
(Expression
(N
));
3687 -- Above are all cases where the value could be determined to be null.
3688 -- In all other cases, we don't know, so return False.
3695 -----------------------------
3696 -- Make_CW_Equivalent_Type --
3697 -----------------------------
3699 -- Create a record type used as an equivalent of any member of the class
3700 -- which takes its size from exp.
3702 -- Generate the following code:
3704 -- type Equiv_T is record
3705 -- _parent : T (List of discriminant constraints taken from Exp);
3706 -- Ext__50 : Storage_Array (1 .. (Exp'size - Typ'object_size)/8);
3709 -- ??? Note that this type does not guarantee same alignment as all
3712 function Make_CW_Equivalent_Type
3714 E
: Node_Id
) return Entity_Id
3716 Loc
: constant Source_Ptr
:= Sloc
(E
);
3717 Root_Typ
: constant Entity_Id
:= Root_Type
(T
);
3718 List_Def
: constant List_Id
:= Empty_List
;
3719 Comp_List
: constant List_Id
:= New_List
;
3720 Equiv_Type
: Entity_Id
;
3721 Range_Type
: Entity_Id
;
3722 Str_Type
: Entity_Id
;
3723 Constr_Root
: Entity_Id
;
3727 if not Has_Discriminants
(Root_Typ
) then
3728 Constr_Root
:= Root_Typ
;
3731 Make_Defining_Identifier
(Loc
, New_Internal_Name
('R'));
3733 -- subtype cstr__n is T (List of discr constraints taken from Exp)
3735 Append_To
(List_Def
,
3736 Make_Subtype_Declaration
(Loc
,
3737 Defining_Identifier
=> Constr_Root
,
3738 Subtype_Indication
=>
3739 Make_Subtype_From_Expr
(E
, Root_Typ
)));
3742 -- Generate the range subtype declaration
3744 Range_Type
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('G'));
3746 if not Is_Interface
(Root_Typ
) then
3748 -- subtype rg__xx is
3749 -- Storage_Offset range 1 .. (Expr'size - typ'size) / Storage_Unit
3752 Make_Op_Subtract
(Loc
,
3754 Make_Attribute_Reference
(Loc
,
3756 OK_Convert_To
(T
, Duplicate_Subexpr_No_Checks
(E
)),
3757 Attribute_Name
=> Name_Size
),
3759 Make_Attribute_Reference
(Loc
,
3760 Prefix
=> New_Reference_To
(Constr_Root
, Loc
),
3761 Attribute_Name
=> Name_Object_Size
));
3763 -- subtype rg__xx is
3764 -- Storage_Offset range 1 .. Expr'size / Storage_Unit
3767 Make_Attribute_Reference
(Loc
,
3769 OK_Convert_To
(T
, Duplicate_Subexpr_No_Checks
(E
)),
3770 Attribute_Name
=> Name_Size
);
3773 Set_Paren_Count
(Sizexpr
, 1);
3775 Append_To
(List_Def
,
3776 Make_Subtype_Declaration
(Loc
,
3777 Defining_Identifier
=> Range_Type
,
3778 Subtype_Indication
=>
3779 Make_Subtype_Indication
(Loc
,
3780 Subtype_Mark
=> New_Reference_To
(RTE
(RE_Storage_Offset
), Loc
),
3781 Constraint
=> Make_Range_Constraint
(Loc
,
3784 Low_Bound
=> Make_Integer_Literal
(Loc
, 1),
3786 Make_Op_Divide
(Loc
,
3787 Left_Opnd
=> Sizexpr
,
3788 Right_Opnd
=> Make_Integer_Literal
(Loc
,
3789 Intval
=> System_Storage_Unit
)))))));
3791 -- subtype str__nn is Storage_Array (rg__x);
3793 Str_Type
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('S'));
3794 Append_To
(List_Def
,
3795 Make_Subtype_Declaration
(Loc
,
3796 Defining_Identifier
=> Str_Type
,
3797 Subtype_Indication
=>
3798 Make_Subtype_Indication
(Loc
,
3799 Subtype_Mark
=> New_Reference_To
(RTE
(RE_Storage_Array
), Loc
),
3801 Make_Index_Or_Discriminant_Constraint
(Loc
,
3803 New_List
(New_Reference_To
(Range_Type
, Loc
))))));
3805 -- type Equiv_T is record
3806 -- [ _parent : Tnn; ]
3810 Equiv_Type
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('T'));
3811 Set_Ekind
(Equiv_Type
, E_Record_Type
);
3812 Set_Parent_Subtype
(Equiv_Type
, Constr_Root
);
3814 -- Set Is_Class_Wide_Equivalent_Type very early to trigger the special
3815 -- treatment for this type. In particular, even though _parent's type
3816 -- is a controlled type or contains controlled components, we do not
3817 -- want to set Has_Controlled_Component on it to avoid making it gain
3818 -- an unwanted _controller component.
3820 Set_Is_Class_Wide_Equivalent_Type
(Equiv_Type
);
3822 if not Is_Interface
(Root_Typ
) then
3823 Append_To
(Comp_List
,
3824 Make_Component_Declaration
(Loc
,
3825 Defining_Identifier
=>
3826 Make_Defining_Identifier
(Loc
, Name_uParent
),
3827 Component_Definition
=>
3828 Make_Component_Definition
(Loc
,
3829 Aliased_Present
=> False,
3830 Subtype_Indication
=> New_Reference_To
(Constr_Root
, Loc
))));
3833 Append_To
(Comp_List
,
3834 Make_Component_Declaration
(Loc
,
3835 Defining_Identifier
=>
3836 Make_Defining_Identifier
(Loc
,
3837 Chars
=> New_Internal_Name
('C')),
3838 Component_Definition
=>
3839 Make_Component_Definition
(Loc
,
3840 Aliased_Present
=> False,
3841 Subtype_Indication
=> New_Reference_To
(Str_Type
, Loc
))));
3843 Append_To
(List_Def
,
3844 Make_Full_Type_Declaration
(Loc
,
3845 Defining_Identifier
=> Equiv_Type
,
3847 Make_Record_Definition
(Loc
,
3849 Make_Component_List
(Loc
,
3850 Component_Items
=> Comp_List
,
3851 Variant_Part
=> Empty
))));
3853 -- Suppress all checks during the analysis of the expanded code
3854 -- to avoid the generation of spurious warnings under ZFP run-time.
3856 Insert_Actions
(E
, List_Def
, Suppress
=> All_Checks
);
3858 end Make_CW_Equivalent_Type
;
3860 ------------------------
3861 -- Make_Literal_Range --
3862 ------------------------
3864 function Make_Literal_Range
3866 Literal_Typ
: Entity_Id
) return Node_Id
3868 Lo
: constant Node_Id
:=
3869 New_Copy_Tree
(String_Literal_Low_Bound
(Literal_Typ
));
3870 Index
: constant Entity_Id
:= Etype
(Lo
);
3873 Length_Expr
: constant Node_Id
:=
3874 Make_Op_Subtract
(Loc
,
3876 Make_Integer_Literal
(Loc
,
3877 Intval
=> String_Literal_Length
(Literal_Typ
)),
3879 Make_Integer_Literal
(Loc
, 1));
3882 Set_Analyzed
(Lo
, False);
3884 if Is_Integer_Type
(Index
) then
3887 Left_Opnd
=> New_Copy_Tree
(Lo
),
3888 Right_Opnd
=> Length_Expr
);
3891 Make_Attribute_Reference
(Loc
,
3892 Attribute_Name
=> Name_Val
,
3893 Prefix
=> New_Occurrence_Of
(Index
, Loc
),
3894 Expressions
=> New_List
(
3897 Make_Attribute_Reference
(Loc
,
3898 Attribute_Name
=> Name_Pos
,
3899 Prefix
=> New_Occurrence_Of
(Index
, Loc
),
3900 Expressions
=> New_List
(New_Copy_Tree
(Lo
))),
3901 Right_Opnd
=> Length_Expr
)));
3908 end Make_Literal_Range
;
3910 --------------------------
3911 -- Make_Non_Empty_Check --
3912 --------------------------
3914 function Make_Non_Empty_Check
3916 N
: Node_Id
) return Node_Id
3922 Make_Attribute_Reference
(Loc
,
3923 Attribute_Name
=> Name_Length
,
3924 Prefix
=> Duplicate_Subexpr_No_Checks
(N
, Name_Req
=> True)),
3926 Make_Integer_Literal
(Loc
, 0));
3927 end Make_Non_Empty_Check
;
3929 ----------------------------
3930 -- Make_Subtype_From_Expr --
3931 ----------------------------
3933 -- 1. If Expr is an unconstrained array expression, creates
3934 -- Unc_Type(Expr'first(1)..Expr'last(1),..., Expr'first(n)..Expr'last(n))
3936 -- 2. If Expr is a unconstrained discriminated type expression, creates
3937 -- Unc_Type(Expr.Discr1, ... , Expr.Discr_n)
3939 -- 3. If Expr is class-wide, creates an implicit class wide subtype
3941 function Make_Subtype_From_Expr
3943 Unc_Typ
: Entity_Id
) return Node_Id
3945 Loc
: constant Source_Ptr
:= Sloc
(E
);
3946 List_Constr
: constant List_Id
:= New_List
;
3949 Full_Subtyp
: Entity_Id
;
3950 Priv_Subtyp
: Entity_Id
;
3955 if Is_Private_Type
(Unc_Typ
)
3956 and then Has_Unknown_Discriminants
(Unc_Typ
)
3958 -- Prepare the subtype completion, Go to base type to
3959 -- find underlying type, because the type may be a generic
3960 -- actual or an explicit subtype.
3962 Utyp
:= Underlying_Type
(Base_Type
(Unc_Typ
));
3963 Full_Subtyp
:= Make_Defining_Identifier
(Loc
,
3964 New_Internal_Name
('C'));
3966 Unchecked_Convert_To
3967 (Utyp
, Duplicate_Subexpr_No_Checks
(E
));
3968 Set_Parent
(Full_Exp
, Parent
(E
));
3971 Make_Defining_Identifier
(Loc
, New_Internal_Name
('P'));
3974 Make_Subtype_Declaration
(Loc
,
3975 Defining_Identifier
=> Full_Subtyp
,
3976 Subtype_Indication
=> Make_Subtype_From_Expr
(Full_Exp
, Utyp
)));
3978 -- Define the dummy private subtype
3980 Set_Ekind
(Priv_Subtyp
, Subtype_Kind
(Ekind
(Unc_Typ
)));
3981 Set_Etype
(Priv_Subtyp
, Base_Type
(Unc_Typ
));
3982 Set_Scope
(Priv_Subtyp
, Full_Subtyp
);
3983 Set_Is_Constrained
(Priv_Subtyp
);
3984 Set_Is_Tagged_Type
(Priv_Subtyp
, Is_Tagged_Type
(Unc_Typ
));
3985 Set_Is_Itype
(Priv_Subtyp
);
3986 Set_Associated_Node_For_Itype
(Priv_Subtyp
, E
);
3988 if Is_Tagged_Type
(Priv_Subtyp
) then
3990 (Base_Type
(Priv_Subtyp
), Class_Wide_Type
(Unc_Typ
));
3991 Set_Primitive_Operations
(Priv_Subtyp
,
3992 Primitive_Operations
(Unc_Typ
));
3995 Set_Full_View
(Priv_Subtyp
, Full_Subtyp
);
3997 return New_Reference_To
(Priv_Subtyp
, Loc
);
3999 elsif Is_Array_Type
(Unc_Typ
) then
4000 for J
in 1 .. Number_Dimensions
(Unc_Typ
) loop
4001 Append_To
(List_Constr
,
4004 Make_Attribute_Reference
(Loc
,
4005 Prefix
=> Duplicate_Subexpr_No_Checks
(E
),
4006 Attribute_Name
=> Name_First
,
4007 Expressions
=> New_List
(
4008 Make_Integer_Literal
(Loc
, J
))),
4011 Make_Attribute_Reference
(Loc
,
4012 Prefix
=> Duplicate_Subexpr_No_Checks
(E
),
4013 Attribute_Name
=> Name_Last
,
4014 Expressions
=> New_List
(
4015 Make_Integer_Literal
(Loc
, J
)))));
4018 elsif Is_Class_Wide_Type
(Unc_Typ
) then
4020 CW_Subtype
: Entity_Id
;
4021 EQ_Typ
: Entity_Id
:= Empty
;
4024 -- A class-wide equivalent type is not needed when VM_Target
4025 -- because the VM back-ends handle the class-wide object
4026 -- initialization itself (and doesn't need or want the
4027 -- additional intermediate type to handle the assignment).
4029 if Expander_Active
and then Tagged_Type_Expansion
then
4030 EQ_Typ
:= Make_CW_Equivalent_Type
(Unc_Typ
, E
);
4033 CW_Subtype
:= New_Class_Wide_Subtype
(Unc_Typ
, E
);
4034 Set_Equivalent_Type
(CW_Subtype
, EQ_Typ
);
4035 Set_Cloned_Subtype
(CW_Subtype
, Base_Type
(Unc_Typ
));
4037 return New_Occurrence_Of
(CW_Subtype
, Loc
);
4040 -- Indefinite record type with discriminants
4043 D
:= First_Discriminant
(Unc_Typ
);
4044 while Present
(D
) loop
4045 Append_To
(List_Constr
,
4046 Make_Selected_Component
(Loc
,
4047 Prefix
=> Duplicate_Subexpr_No_Checks
(E
),
4048 Selector_Name
=> New_Reference_To
(D
, Loc
)));
4050 Next_Discriminant
(D
);
4055 Make_Subtype_Indication
(Loc
,
4056 Subtype_Mark
=> New_Reference_To
(Unc_Typ
, Loc
),
4058 Make_Index_Or_Discriminant_Constraint
(Loc
,
4059 Constraints
=> List_Constr
));
4060 end Make_Subtype_From_Expr
;
4062 -----------------------------
4063 -- May_Generate_Large_Temp --
4064 -----------------------------
4066 -- At the current time, the only types that we return False for (i.e.
4067 -- where we decide we know they cannot generate large temps) are ones
4068 -- where we know the size is 256 bits or less at compile time, and we
4069 -- are still not doing a thorough job on arrays and records ???
4071 function May_Generate_Large_Temp
(Typ
: Entity_Id
) return Boolean is
4073 if not Size_Known_At_Compile_Time
(Typ
) then
4076 elsif Esize
(Typ
) /= 0 and then Esize
(Typ
) <= 256 then
4079 elsif Is_Array_Type
(Typ
)
4080 and then Present
(Packed_Array_Type
(Typ
))
4082 return May_Generate_Large_Temp
(Packed_Array_Type
(Typ
));
4084 -- We could do more here to find other small types ???
4089 end May_Generate_Large_Temp
;
4091 ----------------------------
4092 -- New_Class_Wide_Subtype --
4093 ----------------------------
4095 function New_Class_Wide_Subtype
4096 (CW_Typ
: Entity_Id
;
4097 N
: Node_Id
) return Entity_Id
4099 Res
: constant Entity_Id
:= Create_Itype
(E_Void
, N
);
4100 Res_Name
: constant Name_Id
:= Chars
(Res
);
4101 Res_Scope
: constant Entity_Id
:= Scope
(Res
);
4104 Copy_Node
(CW_Typ
, Res
);
4105 Set_Comes_From_Source
(Res
, False);
4106 Set_Sloc
(Res
, Sloc
(N
));
4108 Set_Associated_Node_For_Itype
(Res
, N
);
4109 Set_Is_Public
(Res
, False); -- By default, may be changed below.
4110 Set_Public_Status
(Res
);
4111 Set_Chars
(Res
, Res_Name
);
4112 Set_Scope
(Res
, Res_Scope
);
4113 Set_Ekind
(Res
, E_Class_Wide_Subtype
);
4114 Set_Next_Entity
(Res
, Empty
);
4115 Set_Etype
(Res
, Base_Type
(CW_Typ
));
4116 Set_Is_Frozen
(Res
, False);
4117 Set_Freeze_Node
(Res
, Empty
);
4119 end New_Class_Wide_Subtype
;
4121 --------------------------------
4122 -- Non_Limited_Designated_Type --
4123 ---------------------------------
4125 function Non_Limited_Designated_Type
(T
: Entity_Id
) return Entity_Id
is
4126 Desig
: constant Entity_Id
:= Designated_Type
(T
);
4128 if Ekind
(Desig
) = E_Incomplete_Type
4129 and then Present
(Non_Limited_View
(Desig
))
4131 return Non_Limited_View
(Desig
);
4135 end Non_Limited_Designated_Type
;
4137 -----------------------------------
4138 -- OK_To_Do_Constant_Replacement --
4139 -----------------------------------
4141 function OK_To_Do_Constant_Replacement
(E
: Entity_Id
) return Boolean is
4142 ES
: constant Entity_Id
:= Scope
(E
);
4146 -- Do not replace statically allocated objects, because they may be
4147 -- modified outside the current scope.
4149 if Is_Statically_Allocated
(E
) then
4152 -- Do not replace aliased or volatile objects, since we don't know what
4153 -- else might change the value.
4155 elsif Is_Aliased
(E
) or else Treat_As_Volatile
(E
) then
4158 -- Debug flag -gnatdM disconnects this optimization
4160 elsif Debug_Flag_MM
then
4163 -- Otherwise check scopes
4166 CS
:= Current_Scope
;
4169 -- If we are in right scope, replacement is safe
4174 -- Packages do not affect the determination of safety
4176 elsif Ekind
(CS
) = E_Package
then
4177 exit when CS
= Standard_Standard
;
4180 -- Blocks do not affect the determination of safety
4182 elsif Ekind
(CS
) = E_Block
then
4185 -- Loops do not affect the determination of safety. Note that we
4186 -- kill all current values on entry to a loop, so we are just
4187 -- talking about processing within a loop here.
4189 elsif Ekind
(CS
) = E_Loop
then
4192 -- Otherwise, the reference is dubious, and we cannot be sure that
4193 -- it is safe to do the replacement.
4202 end OK_To_Do_Constant_Replacement
;
4204 ------------------------------------
4205 -- Possible_Bit_Aligned_Component --
4206 ------------------------------------
4208 function Possible_Bit_Aligned_Component
(N
: Node_Id
) return Boolean is
4212 -- Case of indexed component
4214 when N_Indexed_Component
=>
4216 P
: constant Node_Id
:= Prefix
(N
);
4217 Ptyp
: constant Entity_Id
:= Etype
(P
);
4220 -- If we know the component size and it is less than 64, then
4221 -- we are definitely OK. The back end always does assignment of
4222 -- misaligned small objects correctly.
4224 if Known_Static_Component_Size
(Ptyp
)
4225 and then Component_Size
(Ptyp
) <= 64
4229 -- Otherwise, we need to test the prefix, to see if we are
4230 -- indexing from a possibly unaligned component.
4233 return Possible_Bit_Aligned_Component
(P
);
4237 -- Case of selected component
4239 when N_Selected_Component
=>
4241 P
: constant Node_Id
:= Prefix
(N
);
4242 Comp
: constant Entity_Id
:= Entity
(Selector_Name
(N
));
4245 -- If there is no component clause, then we are in the clear
4246 -- since the back end will never misalign a large component
4247 -- unless it is forced to do so. In the clear means we need
4248 -- only the recursive test on the prefix.
4250 if Component_May_Be_Bit_Aligned
(Comp
) then
4253 return Possible_Bit_Aligned_Component
(P
);
4257 -- For a slice, test the prefix, if that is possibly misaligned,
4258 -- then for sure the slice is!
4261 return Possible_Bit_Aligned_Component
(Prefix
(N
));
4263 -- If we have none of the above, it means that we have fallen off the
4264 -- top testing prefixes recursively, and we now have a stand alone
4265 -- object, where we don't have a problem.
4271 end Possible_Bit_Aligned_Component
;
4273 -------------------------
4274 -- Remove_Side_Effects --
4275 -------------------------
4277 procedure Remove_Side_Effects
4279 Name_Req
: Boolean := False;
4280 Variable_Ref
: Boolean := False)
4282 Loc
: constant Source_Ptr
:= Sloc
(Exp
);
4283 Exp_Type
: constant Entity_Id
:= Etype
(Exp
);
4284 Svg_Suppress
: constant Suppress_Array
:= Scope_Suppress
;
4286 Ref_Type
: Entity_Id
;
4288 Ptr_Typ_Decl
: Node_Id
;
4292 function Side_Effect_Free
(N
: Node_Id
) return Boolean;
4293 -- Determines if the tree N represents an expression that is known not
4294 -- to have side effects, and for which no processing is required.
4296 function Side_Effect_Free
(L
: List_Id
) return Boolean;
4297 -- Determines if all elements of the list L are side effect free
4299 function Safe_Prefixed_Reference
(N
: Node_Id
) return Boolean;
4300 -- The argument N is a construct where the Prefix is dereferenced if it
4301 -- is an access type and the result is a variable. The call returns True
4302 -- if the construct is side effect free (not considering side effects in
4303 -- other than the prefix which are to be tested by the caller).
4305 function Within_In_Parameter
(N
: Node_Id
) return Boolean;
4306 -- Determines if N is a subcomponent of a composite in-parameter. If so,
4307 -- N is not side-effect free when the actual is global and modifiable
4308 -- indirectly from within a subprogram, because it may be passed by
4309 -- reference. The front-end must be conservative here and assume that
4310 -- this may happen with any array or record type. On the other hand, we
4311 -- cannot create temporaries for all expressions for which this
4312 -- condition is true, for various reasons that might require clearing up
4313 -- ??? For example, discriminant references that appear out of place, or
4314 -- spurious type errors with class-wide expressions. As a result, we
4315 -- limit the transformation to loop bounds, which is so far the only
4316 -- case that requires it.
4318 -----------------------------
4319 -- Safe_Prefixed_Reference --
4320 -----------------------------
4322 function Safe_Prefixed_Reference
(N
: Node_Id
) return Boolean is
4324 -- If prefix is not side effect free, definitely not safe
4326 if not Side_Effect_Free
(Prefix
(N
)) then
4329 -- If the prefix is of an access type that is not access-to-constant,
4330 -- then this construct is a variable reference, which means it is to
4331 -- be considered to have side effects if Variable_Ref is set True
4332 -- Exception is an access to an entity that is a constant or an
4333 -- in-parameter which does not come from source, and is the result
4334 -- of a previous removal of side-effects.
4336 elsif Is_Access_Type
(Etype
(Prefix
(N
)))
4337 and then not Is_Access_Constant
(Etype
(Prefix
(N
)))
4338 and then Variable_Ref
4340 if not Is_Entity_Name
(Prefix
(N
)) then
4343 return Ekind
(Entity
(Prefix
(N
))) = E_Constant
4344 or else Ekind
(Entity
(Prefix
(N
))) = E_In_Parameter
;
4347 -- The following test is the simplest way of solving a complex
4348 -- problem uncovered by BB08-010: Side effect on loop bound that
4349 -- is a subcomponent of a global variable:
4350 -- If a loop bound is a subcomponent of a global variable, a
4351 -- modification of that variable within the loop may incorrectly
4352 -- affect the execution of the loop.
4355 (Nkind
(Parent
(Parent
(N
))) /= N_Loop_Parameter_Specification
4356 or else not Within_In_Parameter
(Prefix
(N
)))
4360 -- All other cases are side effect free
4365 end Safe_Prefixed_Reference
;
4367 ----------------------
4368 -- Side_Effect_Free --
4369 ----------------------
4371 function Side_Effect_Free
(N
: Node_Id
) return Boolean is
4373 -- Note on checks that could raise Constraint_Error. Strictly, if
4374 -- we take advantage of 11.6, these checks do not count as side
4375 -- effects. However, we would just as soon consider that they are
4376 -- side effects, since the backend CSE does not work very well on
4377 -- expressions which can raise Constraint_Error. On the other
4378 -- hand, if we do not consider them to be side effect free, then
4379 -- we get some awkward expansions in -gnato mode, resulting in
4380 -- code insertions at a point where we do not have a clear model
4381 -- for performing the insertions.
4383 -- Special handling for entity names
4385 if Is_Entity_Name
(N
) then
4387 -- If the entity is a constant, it is definitely side effect
4388 -- free. Note that the test of Is_Variable (N) below might
4389 -- be expected to catch this case, but it does not, because
4390 -- this test goes to the original tree, and we may have
4391 -- already rewritten a variable node with a constant as
4392 -- a result of an earlier Force_Evaluation call.
4394 if Ekind
(Entity
(N
)) = E_Constant
4395 or else Ekind
(Entity
(N
)) = E_In_Parameter
4399 -- Functions are not side effect free
4401 elsif Ekind
(Entity
(N
)) = E_Function
then
4404 -- Variables are considered to be a side effect if Variable_Ref
4405 -- is set or if we have a volatile reference and Name_Req is off.
4406 -- If Name_Req is True then we can't help returning a name which
4407 -- effectively allows multiple references in any case.
4409 elsif Is_Variable
(N
) then
4410 return not Variable_Ref
4411 and then (not Is_Volatile_Reference
(N
) or else Name_Req
);
4413 -- Any other entity (e.g. a subtype name) is definitely side
4420 -- A value known at compile time is always side effect free
4422 elsif Compile_Time_Known_Value
(N
) then
4425 -- A variable renaming is not side-effect free, because the
4426 -- renaming will function like a macro in the front-end in
4427 -- some cases, and an assignment can modify the component
4428 -- designated by N, so we need to create a temporary for it.
4430 elsif Is_Entity_Name
(Original_Node
(N
))
4431 and then Is_Renaming_Of_Object
(Entity
(Original_Node
(N
)))
4432 and then Ekind
(Entity
(Original_Node
(N
))) /= E_Constant
4437 -- For other than entity names and compile time known values,
4438 -- check the node kind for special processing.
4442 -- An attribute reference is side effect free if its expressions
4443 -- are side effect free and its prefix is side effect free or
4444 -- is an entity reference.
4446 -- Is this right? what about x'first where x is a variable???
4448 when N_Attribute_Reference
=>
4449 return Side_Effect_Free
(Expressions
(N
))
4450 and then Attribute_Name
(N
) /= Name_Input
4451 and then (Is_Entity_Name
(Prefix
(N
))
4452 or else Side_Effect_Free
(Prefix
(N
)));
4454 -- A binary operator is side effect free if and both operands
4455 -- are side effect free. For this purpose binary operators
4456 -- include membership tests and short circuit forms
4458 when N_Binary_Op | N_Membership_Test | N_Short_Circuit
=>
4459 return Side_Effect_Free
(Left_Opnd
(N
))
4461 Side_Effect_Free
(Right_Opnd
(N
));
4463 -- An explicit dereference is side effect free only if it is
4464 -- a side effect free prefixed reference.
4466 when N_Explicit_Dereference
=>
4467 return Safe_Prefixed_Reference
(N
);
4469 -- A call to _rep_to_pos is side effect free, since we generate
4470 -- this pure function call ourselves. Moreover it is critically
4471 -- important to make this exception, since otherwise we can
4472 -- have discriminants in array components which don't look
4473 -- side effect free in the case of an array whose index type
4474 -- is an enumeration type with an enumeration rep clause.
4476 -- All other function calls are not side effect free
4478 when N_Function_Call
=>
4479 return Nkind
(Name
(N
)) = N_Identifier
4480 and then Is_TSS
(Name
(N
), TSS_Rep_To_Pos
)
4482 Side_Effect_Free
(First
(Parameter_Associations
(N
)));
4484 -- An indexed component is side effect free if it is a side
4485 -- effect free prefixed reference and all the indexing
4486 -- expressions are side effect free.
4488 when N_Indexed_Component
=>
4489 return Side_Effect_Free
(Expressions
(N
))
4490 and then Safe_Prefixed_Reference
(N
);
4492 -- A type qualification is side effect free if the expression
4493 -- is side effect free.
4495 when N_Qualified_Expression
=>
4496 return Side_Effect_Free
(Expression
(N
));
4498 -- A selected component is side effect free only if it is a
4499 -- side effect free prefixed reference. If it designates a
4500 -- component with a rep. clause it must be treated has having
4501 -- a potential side effect, because it may be modified through
4502 -- a renaming, and a subsequent use of the renaming as a macro
4503 -- will yield the wrong value. This complex interaction between
4504 -- renaming and removing side effects is a reminder that the
4505 -- latter has become a headache to maintain, and that it should
4506 -- be removed in favor of the gcc mechanism to capture values ???
4508 when N_Selected_Component
=>
4509 if Nkind
(Parent
(N
)) = N_Explicit_Dereference
4510 and then Has_Non_Standard_Rep
(Designated_Type
(Etype
(N
)))
4514 return Safe_Prefixed_Reference
(N
);
4517 -- A range is side effect free if the bounds are side effect free
4520 return Side_Effect_Free
(Low_Bound
(N
))
4521 and then Side_Effect_Free
(High_Bound
(N
));
4523 -- A slice is side effect free if it is a side effect free
4524 -- prefixed reference and the bounds are side effect free.
4527 return Side_Effect_Free
(Discrete_Range
(N
))
4528 and then Safe_Prefixed_Reference
(N
);
4530 -- A type conversion is side effect free if the expression to be
4531 -- converted is side effect free.
4533 when N_Type_Conversion
=>
4534 return Side_Effect_Free
(Expression
(N
));
4536 -- A unary operator is side effect free if the operand
4537 -- is side effect free.
4540 return Side_Effect_Free
(Right_Opnd
(N
));
4542 -- An unchecked type conversion is side effect free only if it
4543 -- is safe and its argument is side effect free.
4545 when N_Unchecked_Type_Conversion
=>
4546 return Safe_Unchecked_Type_Conversion
(N
)
4547 and then Side_Effect_Free
(Expression
(N
));
4549 -- An unchecked expression is side effect free if its expression
4550 -- is side effect free.
4552 when N_Unchecked_Expression
=>
4553 return Side_Effect_Free
(Expression
(N
));
4555 -- A literal is side effect free
4557 when N_Character_Literal |
4563 -- We consider that anything else has side effects. This is a bit
4564 -- crude, but we are pretty close for most common cases, and we
4565 -- are certainly correct (i.e. we never return True when the
4566 -- answer should be False).
4571 end Side_Effect_Free
;
4573 -- A list is side effect free if all elements of the list are
4574 -- side effect free.
4576 function Side_Effect_Free
(L
: List_Id
) return Boolean is
4580 if L
= No_List
or else L
= Error_List
then
4585 while Present
(N
) loop
4586 if not Side_Effect_Free
(N
) then
4595 end Side_Effect_Free
;
4597 -------------------------
4598 -- Within_In_Parameter --
4599 -------------------------
4601 function Within_In_Parameter
(N
: Node_Id
) return Boolean is
4603 if not Comes_From_Source
(N
) then
4606 elsif Is_Entity_Name
(N
) then
4607 return Ekind
(Entity
(N
)) = E_In_Parameter
;
4609 elsif Nkind
(N
) = N_Indexed_Component
4610 or else Nkind
(N
) = N_Selected_Component
4612 return Within_In_Parameter
(Prefix
(N
));
4617 end Within_In_Parameter
;
4619 -- Start of processing for Remove_Side_Effects
4622 -- If we are side effect free already or expansion is disabled,
4623 -- there is nothing to do.
4625 if Side_Effect_Free
(Exp
) or else not Expander_Active
then
4629 -- All this must not have any checks
4631 Scope_Suppress
:= (others => True);
4633 -- If it is a scalar type and we need to capture the value, just make
4634 -- a copy. Likewise for a function call, an attribute reference or an
4635 -- operator. And if we have a volatile reference and Name_Req is not
4636 -- set (see comments above for Side_Effect_Free).
4638 if Is_Elementary_Type
(Exp_Type
)
4639 and then (Variable_Ref
4640 or else Nkind
(Exp
) = N_Function_Call
4641 or else Nkind
(Exp
) = N_Attribute_Reference
4642 or else Nkind
(Exp
) in N_Op
4643 or else (not Name_Req
and then Is_Volatile_Reference
(Exp
)))
4645 Def_Id
:= Make_Temporary
(Loc
, 'R', Exp
);
4646 Set_Etype
(Def_Id
, Exp_Type
);
4647 Res
:= New_Reference_To
(Def_Id
, Loc
);
4650 Make_Object_Declaration
(Loc
,
4651 Defining_Identifier
=> Def_Id
,
4652 Object_Definition
=> New_Reference_To
(Exp_Type
, Loc
),
4653 Constant_Present
=> True,
4654 Expression
=> Relocate_Node
(Exp
));
4656 -- Check if the previous node relocation requires readjustment of
4657 -- some SCIL Dispatching node.
4660 and then Nkind
(Exp
) = N_Function_Call
4662 Adjust_SCIL_Node
(Exp
, Expression
(E
));
4665 Set_Assignment_OK
(E
);
4666 Insert_Action
(Exp
, E
);
4668 -- If the expression has the form v.all then we can just capture
4669 -- the pointer, and then do an explicit dereference on the result.
4671 elsif Nkind
(Exp
) = N_Explicit_Dereference
then
4672 Def_Id
:= Make_Temporary
(Loc
, 'R', Exp
);
4674 Make_Explicit_Dereference
(Loc
, New_Reference_To
(Def_Id
, Loc
));
4677 Make_Object_Declaration
(Loc
,
4678 Defining_Identifier
=> Def_Id
,
4679 Object_Definition
=>
4680 New_Reference_To
(Etype
(Prefix
(Exp
)), Loc
),
4681 Constant_Present
=> True,
4682 Expression
=> Relocate_Node
(Prefix
(Exp
))));
4684 -- Similar processing for an unchecked conversion of an expression
4685 -- of the form v.all, where we want the same kind of treatment.
4687 elsif Nkind
(Exp
) = N_Unchecked_Type_Conversion
4688 and then Nkind
(Expression
(Exp
)) = N_Explicit_Dereference
4690 Remove_Side_Effects
(Expression
(Exp
), Name_Req
, Variable_Ref
);
4691 Scope_Suppress
:= Svg_Suppress
;
4694 -- If this is a type conversion, leave the type conversion and remove
4695 -- the side effects in the expression. This is important in several
4696 -- circumstances: for change of representations, and also when this is
4697 -- a view conversion to a smaller object, where gigi can end up creating
4698 -- its own temporary of the wrong size.
4700 elsif Nkind
(Exp
) = N_Type_Conversion
then
4701 Remove_Side_Effects
(Expression
(Exp
), Name_Req
, Variable_Ref
);
4702 Scope_Suppress
:= Svg_Suppress
;
4705 -- If this is an unchecked conversion that Gigi can't handle, make
4706 -- a copy or a use a renaming to capture the value.
4708 elsif Nkind
(Exp
) = N_Unchecked_Type_Conversion
4709 and then not Safe_Unchecked_Type_Conversion
(Exp
)
4711 if CW_Or_Has_Controlled_Part
(Exp_Type
) then
4713 -- Use a renaming to capture the expression, rather than create
4714 -- a controlled temporary.
4716 Def_Id
:= Make_Temporary
(Loc
, 'R', Exp
);
4717 Res
:= New_Reference_To
(Def_Id
, Loc
);
4720 Make_Object_Renaming_Declaration
(Loc
,
4721 Defining_Identifier
=> Def_Id
,
4722 Subtype_Mark
=> New_Reference_To
(Exp_Type
, Loc
),
4723 Name
=> Relocate_Node
(Exp
)));
4726 Def_Id
:= Make_Temporary
(Loc
, 'R', Exp
);
4727 Set_Etype
(Def_Id
, Exp_Type
);
4728 Res
:= New_Reference_To
(Def_Id
, Loc
);
4731 Make_Object_Declaration
(Loc
,
4732 Defining_Identifier
=> Def_Id
,
4733 Object_Definition
=> New_Reference_To
(Exp_Type
, Loc
),
4734 Constant_Present
=> not Is_Variable
(Exp
),
4735 Expression
=> Relocate_Node
(Exp
));
4737 Set_Assignment_OK
(E
);
4738 Insert_Action
(Exp
, E
);
4741 -- For expressions that denote objects, we can use a renaming scheme.
4742 -- We skip using this if we have a volatile reference and we do not
4743 -- have Name_Req set true (see comments above for Side_Effect_Free).
4745 elsif Is_Object_Reference
(Exp
)
4746 and then Nkind
(Exp
) /= N_Function_Call
4747 and then (Name_Req
or else not Is_Volatile_Reference
(Exp
))
4749 Def_Id
:= Make_Temporary
(Loc
, 'R', Exp
);
4751 if Nkind
(Exp
) = N_Selected_Component
4752 and then Nkind
(Prefix
(Exp
)) = N_Function_Call
4753 and then Is_Array_Type
(Exp_Type
)
4755 -- Avoid generating a variable-sized temporary, by generating
4756 -- the renaming declaration just for the function call. The
4757 -- transformation could be refined to apply only when the array
4758 -- component is constrained by a discriminant???
4761 Make_Selected_Component
(Loc
,
4762 Prefix
=> New_Occurrence_Of
(Def_Id
, Loc
),
4763 Selector_Name
=> Selector_Name
(Exp
));
4766 Make_Object_Renaming_Declaration
(Loc
,
4767 Defining_Identifier
=> Def_Id
,
4769 New_Reference_To
(Base_Type
(Etype
(Prefix
(Exp
))), Loc
),
4770 Name
=> Relocate_Node
(Prefix
(Exp
))));
4773 Res
:= New_Reference_To
(Def_Id
, Loc
);
4776 Make_Object_Renaming_Declaration
(Loc
,
4777 Defining_Identifier
=> Def_Id
,
4778 Subtype_Mark
=> New_Reference_To
(Exp_Type
, Loc
),
4779 Name
=> Relocate_Node
(Exp
)));
4782 -- If this is a packed reference, or a selected component with a
4783 -- non-standard representation, a reference to the temporary will
4784 -- be replaced by a copy of the original expression (see
4785 -- Exp_Ch2.Expand_Renaming). Otherwise the temporary must be
4786 -- elaborated by gigi, and is of course not to be replaced in-line
4787 -- by the expression it renames, which would defeat the purpose of
4788 -- removing the side-effect.
4790 if (Nkind
(Exp
) = N_Selected_Component
4791 or else Nkind
(Exp
) = N_Indexed_Component
)
4792 and then Has_Non_Standard_Rep
(Etype
(Prefix
(Exp
)))
4796 Set_Is_Renaming_Of_Object
(Def_Id
, False);
4799 -- Otherwise we generate a reference to the value
4802 -- Special processing for function calls that return a limited type.
4803 -- We need to build a declaration that will enable build-in-place
4804 -- expansion of the call. This is not done if the context is already
4805 -- an object declaration, to prevent infinite recursion.
4807 -- This is relevant only in Ada 2005 mode. In Ada 95 programs we have
4808 -- to accommodate functions returning limited objects by reference.
4810 if Nkind
(Exp
) = N_Function_Call
4811 and then Is_Inherently_Limited_Type
(Etype
(Exp
))
4812 and then Nkind
(Parent
(Exp
)) /= N_Object_Declaration
4813 and then Ada_Version
>= Ada_05
4816 Obj
: constant Entity_Id
:= Make_Temporary
(Loc
, 'F', Exp
);
4821 Make_Object_Declaration
(Loc
,
4822 Defining_Identifier
=> Obj
,
4823 Object_Definition
=> New_Occurrence_Of
(Exp_Type
, Loc
),
4824 Expression
=> Relocate_Node
(Exp
));
4826 -- Check if the previous node relocation requires readjustment
4827 -- of some SCIL Dispatching node.
4830 and then Nkind
(Exp
) = N_Function_Call
4832 Adjust_SCIL_Node
(Exp
, Expression
(Decl
));
4835 Insert_Action
(Exp
, Decl
);
4836 Set_Etype
(Obj
, Exp_Type
);
4837 Rewrite
(Exp
, New_Occurrence_Of
(Obj
, Loc
));
4842 Ref_Type
:= Make_Defining_Identifier
(Loc
, New_Internal_Name
('A'));
4845 Make_Full_Type_Declaration
(Loc
,
4846 Defining_Identifier
=> Ref_Type
,
4848 Make_Access_To_Object_Definition
(Loc
,
4849 All_Present
=> True,
4850 Subtype_Indication
=>
4851 New_Reference_To
(Exp_Type
, Loc
)));
4854 Insert_Action
(Exp
, Ptr_Typ_Decl
);
4856 Def_Id
:= Make_Temporary
(Loc
, 'R', Exp
);
4857 Set_Etype
(Def_Id
, Exp_Type
);
4860 Make_Explicit_Dereference
(Loc
,
4861 Prefix
=> New_Reference_To
(Def_Id
, Loc
));
4863 if Nkind
(E
) = N_Explicit_Dereference
then
4864 New_Exp
:= Relocate_Node
(Prefix
(E
));
4866 E
:= Relocate_Node
(E
);
4867 New_Exp
:= Make_Reference
(Loc
, E
);
4870 if Is_Delayed_Aggregate
(E
) then
4872 -- The expansion of nested aggregates is delayed until the
4873 -- enclosing aggregate is expanded. As aggregates are often
4874 -- qualified, the predicate applies to qualified expressions
4875 -- as well, indicating that the enclosing aggregate has not
4876 -- been expanded yet. At this point the aggregate is part of
4877 -- a stand-alone declaration, and must be fully expanded.
4879 if Nkind
(E
) = N_Qualified_Expression
then
4880 Set_Expansion_Delayed
(Expression
(E
), False);
4881 Set_Analyzed
(Expression
(E
), False);
4883 Set_Expansion_Delayed
(E
, False);
4886 Set_Analyzed
(E
, False);
4890 Make_Object_Declaration
(Loc
,
4891 Defining_Identifier
=> Def_Id
,
4892 Object_Definition
=> New_Reference_To
(Ref_Type
, Loc
),
4893 Expression
=> New_Exp
));
4895 -- Check if the previous node relocation requires readjustment
4896 -- of some SCIL Dispatching node.
4899 and then Nkind
(Exp
) = N_Function_Call
4901 Adjust_SCIL_Node
(Exp
, Prefix
(New_Exp
));
4905 -- Preserve the Assignment_OK flag in all copies, since at least
4906 -- one copy may be used in a context where this flag must be set
4907 -- (otherwise why would the flag be set in the first place).
4909 Set_Assignment_OK
(Res
, Assignment_OK
(Exp
));
4911 -- Finally rewrite the original expression and we are done
4914 Analyze_And_Resolve
(Exp
, Exp_Type
);
4915 Scope_Suppress
:= Svg_Suppress
;
4916 end Remove_Side_Effects
;
4918 ---------------------------
4919 -- Represented_As_Scalar --
4920 ---------------------------
4922 function Represented_As_Scalar
(T
: Entity_Id
) return Boolean is
4923 UT
: constant Entity_Id
:= Underlying_Type
(T
);
4925 return Is_Scalar_Type
(UT
)
4926 or else (Is_Bit_Packed_Array
(UT
)
4927 and then Is_Scalar_Type
(Packed_Array_Type
(UT
)));
4928 end Represented_As_Scalar
;
4930 ------------------------------------
4931 -- Safe_Unchecked_Type_Conversion --
4932 ------------------------------------
4934 -- Note: this function knows quite a bit about the exact requirements
4935 -- of Gigi with respect to unchecked type conversions, and its code
4936 -- must be coordinated with any changes in Gigi in this area.
4938 -- The above requirements should be documented in Sinfo ???
4940 function Safe_Unchecked_Type_Conversion
(Exp
: Node_Id
) return Boolean is
4945 Pexp
: constant Node_Id
:= Parent
(Exp
);
4948 -- If the expression is the RHS of an assignment or object declaration
4949 -- we are always OK because there will always be a target.
4951 -- Object renaming declarations, (generated for view conversions of
4952 -- actuals in inlined calls), like object declarations, provide an
4953 -- explicit type, and are safe as well.
4955 if (Nkind
(Pexp
) = N_Assignment_Statement
4956 and then Expression
(Pexp
) = Exp
)
4957 or else Nkind
(Pexp
) = N_Object_Declaration
4958 or else Nkind
(Pexp
) = N_Object_Renaming_Declaration
4962 -- If the expression is the prefix of an N_Selected_Component
4963 -- we should also be OK because GCC knows to look inside the
4964 -- conversion except if the type is discriminated. We assume
4965 -- that we are OK anyway if the type is not set yet or if it is
4966 -- controlled since we can't afford to introduce a temporary in
4969 elsif Nkind
(Pexp
) = N_Selected_Component
4970 and then Prefix
(Pexp
) = Exp
4972 if No
(Etype
(Pexp
)) then
4976 not Has_Discriminants
(Etype
(Pexp
))
4977 or else Is_Constrained
(Etype
(Pexp
));
4981 -- Set the output type, this comes from Etype if it is set, otherwise
4982 -- we take it from the subtype mark, which we assume was already
4985 if Present
(Etype
(Exp
)) then
4986 Otyp
:= Etype
(Exp
);
4988 Otyp
:= Entity
(Subtype_Mark
(Exp
));
4991 -- The input type always comes from the expression, and we assume
4992 -- this is indeed always analyzed, so we can simply get the Etype.
4994 Ityp
:= Etype
(Expression
(Exp
));
4996 -- Initialize alignments to unknown so far
5001 -- Replace a concurrent type by its corresponding record type
5002 -- and each type by its underlying type and do the tests on those.
5003 -- The original type may be a private type whose completion is a
5004 -- concurrent type, so find the underlying type first.
5006 if Present
(Underlying_Type
(Otyp
)) then
5007 Otyp
:= Underlying_Type
(Otyp
);
5010 if Present
(Underlying_Type
(Ityp
)) then
5011 Ityp
:= Underlying_Type
(Ityp
);
5014 if Is_Concurrent_Type
(Otyp
) then
5015 Otyp
:= Corresponding_Record_Type
(Otyp
);
5018 if Is_Concurrent_Type
(Ityp
) then
5019 Ityp
:= Corresponding_Record_Type
(Ityp
);
5022 -- If the base types are the same, we know there is no problem since
5023 -- this conversion will be a noop.
5025 if Implementation_Base_Type
(Otyp
) = Implementation_Base_Type
(Ityp
) then
5028 -- Same if this is an upwards conversion of an untagged type, and there
5029 -- are no constraints involved (could be more general???)
5031 elsif Etype
(Ityp
) = Otyp
5032 and then not Is_Tagged_Type
(Ityp
)
5033 and then not Has_Discriminants
(Ityp
)
5034 and then No
(First_Rep_Item
(Base_Type
(Ityp
)))
5038 -- If the expression has an access type (object or subprogram) we
5039 -- assume that the conversion is safe, because the size of the target
5040 -- is safe, even if it is a record (which might be treated as having
5041 -- unknown size at this point).
5043 elsif Is_Access_Type
(Ityp
) then
5046 -- If the size of output type is known at compile time, there is
5047 -- never a problem. Note that unconstrained records are considered
5048 -- to be of known size, but we can't consider them that way here,
5049 -- because we are talking about the actual size of the object.
5051 -- We also make sure that in addition to the size being known, we do
5052 -- not have a case which might generate an embarrassingly large temp
5053 -- in stack checking mode.
5055 elsif Size_Known_At_Compile_Time
(Otyp
)
5057 (not Stack_Checking_Enabled
5058 or else not May_Generate_Large_Temp
(Otyp
))
5059 and then not (Is_Record_Type
(Otyp
) and then not Is_Constrained
(Otyp
))
5063 -- If either type is tagged, then we know the alignment is OK so
5064 -- Gigi will be able to use pointer punning.
5066 elsif Is_Tagged_Type
(Otyp
) or else Is_Tagged_Type
(Ityp
) then
5069 -- If either type is a limited record type, we cannot do a copy, so
5070 -- say safe since there's nothing else we can do.
5072 elsif Is_Limited_Record
(Otyp
) or else Is_Limited_Record
(Ityp
) then
5075 -- Conversions to and from packed array types are always ignored and
5078 elsif Is_Packed_Array_Type
(Otyp
)
5079 or else Is_Packed_Array_Type
(Ityp
)
5084 -- The only other cases known to be safe is if the input type's
5085 -- alignment is known to be at least the maximum alignment for the
5086 -- target or if both alignments are known and the output type's
5087 -- alignment is no stricter than the input's. We can use the alignment
5088 -- of the component type of an array if a type is an unpacked
5091 if Present
(Alignment_Clause
(Otyp
)) then
5092 Oalign
:= Expr_Value
(Expression
(Alignment_Clause
(Otyp
)));
5094 elsif Is_Array_Type
(Otyp
)
5095 and then Present
(Alignment_Clause
(Component_Type
(Otyp
)))
5097 Oalign
:= Expr_Value
(Expression
(Alignment_Clause
5098 (Component_Type
(Otyp
))));
5101 if Present
(Alignment_Clause
(Ityp
)) then
5102 Ialign
:= Expr_Value
(Expression
(Alignment_Clause
(Ityp
)));
5104 elsif Is_Array_Type
(Ityp
)
5105 and then Present
(Alignment_Clause
(Component_Type
(Ityp
)))
5107 Ialign
:= Expr_Value
(Expression
(Alignment_Clause
5108 (Component_Type
(Ityp
))));
5111 if Ialign
/= No_Uint
and then Ialign
> Maximum_Alignment
then
5114 elsif Ialign
/= No_Uint
and then Oalign
/= No_Uint
5115 and then Ialign
<= Oalign
5119 -- Otherwise, Gigi cannot handle this and we must make a temporary
5124 end Safe_Unchecked_Type_Conversion
;
5126 ---------------------------------
5127 -- Set_Current_Value_Condition --
5128 ---------------------------------
5130 -- Note: the implementation of this procedure is very closely tied to the
5131 -- implementation of Get_Current_Value_Condition. Here we set required
5132 -- Current_Value fields, and in Get_Current_Value_Condition, we interpret
5133 -- them, so they must have a consistent view.
5135 procedure Set_Current_Value_Condition
(Cnode
: Node_Id
) is
5137 procedure Set_Entity_Current_Value
(N
: Node_Id
);
5138 -- If N is an entity reference, where the entity is of an appropriate
5139 -- kind, then set the current value of this entity to Cnode, unless
5140 -- there is already a definite value set there.
5142 procedure Set_Expression_Current_Value
(N
: Node_Id
);
5143 -- If N is of an appropriate form, sets an appropriate entry in current
5144 -- value fields of relevant entities. Multiple entities can be affected
5145 -- in the case of an AND or AND THEN.
5147 ------------------------------
5148 -- Set_Entity_Current_Value --
5149 ------------------------------
5151 procedure Set_Entity_Current_Value
(N
: Node_Id
) is
5153 if Is_Entity_Name
(N
) then
5155 Ent
: constant Entity_Id
:= Entity
(N
);
5158 -- Don't capture if not safe to do so
5160 if not Safe_To_Capture_Value
(N
, Ent
, Cond
=> True) then
5164 -- Here we have a case where the Current_Value field may
5165 -- need to be set. We set it if it is not already set to a
5166 -- compile time expression value.
5168 -- Note that this represents a decision that one condition
5169 -- blots out another previous one. That's certainly right
5170 -- if they occur at the same level. If the second one is
5171 -- nested, then the decision is neither right nor wrong (it
5172 -- would be equally OK to leave the outer one in place, or
5173 -- take the new inner one. Really we should record both, but
5174 -- our data structures are not that elaborate.
5176 if Nkind
(Current_Value
(Ent
)) not in N_Subexpr
then
5177 Set_Current_Value
(Ent
, Cnode
);
5181 end Set_Entity_Current_Value
;
5183 ----------------------------------
5184 -- Set_Expression_Current_Value --
5185 ----------------------------------
5187 procedure Set_Expression_Current_Value
(N
: Node_Id
) is
5193 -- Loop to deal with (ignore for now) any NOT operators present. The
5194 -- presence of NOT operators will be handled properly when we call
5195 -- Get_Current_Value_Condition.
5197 while Nkind
(Cond
) = N_Op_Not
loop
5198 Cond
:= Right_Opnd
(Cond
);
5201 -- For an AND or AND THEN, recursively process operands
5203 if Nkind
(Cond
) = N_Op_And
or else Nkind
(Cond
) = N_And_Then
then
5204 Set_Expression_Current_Value
(Left_Opnd
(Cond
));
5205 Set_Expression_Current_Value
(Right_Opnd
(Cond
));
5209 -- Check possible relational operator
5211 if Nkind
(Cond
) in N_Op_Compare
then
5212 if Compile_Time_Known_Value
(Right_Opnd
(Cond
)) then
5213 Set_Entity_Current_Value
(Left_Opnd
(Cond
));
5214 elsif Compile_Time_Known_Value
(Left_Opnd
(Cond
)) then
5215 Set_Entity_Current_Value
(Right_Opnd
(Cond
));
5218 -- Check possible boolean variable reference
5221 Set_Entity_Current_Value
(Cond
);
5223 end Set_Expression_Current_Value
;
5225 -- Start of processing for Set_Current_Value_Condition
5228 Set_Expression_Current_Value
(Condition
(Cnode
));
5229 end Set_Current_Value_Condition
;
5231 --------------------------
5232 -- Set_Elaboration_Flag --
5233 --------------------------
5235 procedure Set_Elaboration_Flag
(N
: Node_Id
; Spec_Id
: Entity_Id
) is
5236 Loc
: constant Source_Ptr
:= Sloc
(N
);
5237 Ent
: constant Entity_Id
:= Elaboration_Entity
(Spec_Id
);
5241 if Present
(Ent
) then
5243 -- Nothing to do if at the compilation unit level, because in this
5244 -- case the flag is set by the binder generated elaboration routine.
5246 if Nkind
(Parent
(N
)) = N_Compilation_Unit
then
5249 -- Here we do need to generate an assignment statement
5252 Check_Restriction
(No_Elaboration_Code
, N
);
5254 Make_Assignment_Statement
(Loc
,
5255 Name
=> New_Occurrence_Of
(Ent
, Loc
),
5256 Expression
=> New_Occurrence_Of
(Standard_True
, Loc
));
5258 if Nkind
(Parent
(N
)) = N_Subunit
then
5259 Insert_After
(Corresponding_Stub
(Parent
(N
)), Asn
);
5261 Insert_After
(N
, Asn
);
5266 -- Kill current value indication. This is necessary because the
5267 -- tests of this flag are inserted out of sequence and must not
5268 -- pick up bogus indications of the wrong constant value.
5270 Set_Current_Value
(Ent
, Empty
);
5273 end Set_Elaboration_Flag
;
5275 ----------------------------
5276 -- Set_Renamed_Subprogram --
5277 ----------------------------
5279 procedure Set_Renamed_Subprogram
(N
: Node_Id
; E
: Entity_Id
) is
5281 -- If input node is an identifier, we can just reset it
5283 if Nkind
(N
) = N_Identifier
then
5284 Set_Chars
(N
, Chars
(E
));
5287 -- Otherwise we have to do a rewrite, preserving Comes_From_Source
5291 CS
: constant Boolean := Comes_From_Source
(N
);
5293 Rewrite
(N
, Make_Identifier
(Sloc
(N
), Chars
=> Chars
(E
)));
5295 Set_Comes_From_Source
(N
, CS
);
5296 Set_Analyzed
(N
, True);
5299 end Set_Renamed_Subprogram
;
5301 ----------------------------------
5302 -- Silly_Boolean_Array_Not_Test --
5303 ----------------------------------
5305 -- This procedure implements an odd and silly test. We explicitly check
5306 -- for the case where the 'First of the component type is equal to the
5307 -- 'Last of this component type, and if this is the case, we make sure
5308 -- that constraint error is raised. The reason is that the NOT is bound
5309 -- to cause CE in this case, and we will not otherwise catch it.
5311 -- No such check is required for AND and OR, since for both these cases
5312 -- False op False = False, and True op True = True. For the XOR case,
5313 -- see Silly_Boolean_Array_Xor_Test.
5315 -- Believe it or not, this was reported as a bug. Note that nearly
5316 -- always, the test will evaluate statically to False, so the code will
5317 -- be statically removed, and no extra overhead caused.
5319 procedure Silly_Boolean_Array_Not_Test
(N
: Node_Id
; T
: Entity_Id
) is
5320 Loc
: constant Source_Ptr
:= Sloc
(N
);
5321 CT
: constant Entity_Id
:= Component_Type
(T
);
5324 -- The check we install is
5326 -- constraint_error when
5327 -- component_type'first = component_type'last
5328 -- and then array_type'Length /= 0)
5330 -- We need the last guard because we don't want to raise CE for empty
5331 -- arrays since no out of range values result. (Empty arrays with a
5332 -- component type of True .. True -- very useful -- even the ACATS
5333 -- does not test that marginal case!)
5336 Make_Raise_Constraint_Error
(Loc
,
5342 Make_Attribute_Reference
(Loc
,
5343 Prefix
=> New_Occurrence_Of
(CT
, Loc
),
5344 Attribute_Name
=> Name_First
),
5347 Make_Attribute_Reference
(Loc
,
5348 Prefix
=> New_Occurrence_Of
(CT
, Loc
),
5349 Attribute_Name
=> Name_Last
)),
5351 Right_Opnd
=> Make_Non_Empty_Check
(Loc
, Right_Opnd
(N
))),
5352 Reason
=> CE_Range_Check_Failed
));
5353 end Silly_Boolean_Array_Not_Test
;
5355 ----------------------------------
5356 -- Silly_Boolean_Array_Xor_Test --
5357 ----------------------------------
5359 -- This procedure implements an odd and silly test. We explicitly check
5360 -- for the XOR case where the component type is True .. True, since this
5361 -- will raise constraint error. A special check is required since CE
5362 -- will not be generated otherwise (cf Expand_Packed_Not).
5364 -- No such check is required for AND and OR, since for both these cases
5365 -- False op False = False, and True op True = True, and no check is
5366 -- required for the case of False .. False, since False xor False = False.
5367 -- See also Silly_Boolean_Array_Not_Test
5369 procedure Silly_Boolean_Array_Xor_Test
(N
: Node_Id
; T
: Entity_Id
) is
5370 Loc
: constant Source_Ptr
:= Sloc
(N
);
5371 CT
: constant Entity_Id
:= Component_Type
(T
);
5374 -- The check we install is
5376 -- constraint_error when
5377 -- Boolean (component_type'First)
5378 -- and then Boolean (component_type'Last)
5379 -- and then array_type'Length /= 0)
5381 -- We need the last guard because we don't want to raise CE for empty
5382 -- arrays since no out of range values result (Empty arrays with a
5383 -- component type of True .. True -- very useful -- even the ACATS
5384 -- does not test that marginal case!).
5387 Make_Raise_Constraint_Error
(Loc
,
5393 Convert_To
(Standard_Boolean
,
5394 Make_Attribute_Reference
(Loc
,
5395 Prefix
=> New_Occurrence_Of
(CT
, Loc
),
5396 Attribute_Name
=> Name_First
)),
5399 Convert_To
(Standard_Boolean
,
5400 Make_Attribute_Reference
(Loc
,
5401 Prefix
=> New_Occurrence_Of
(CT
, Loc
),
5402 Attribute_Name
=> Name_Last
))),
5404 Right_Opnd
=> Make_Non_Empty_Check
(Loc
, Right_Opnd
(N
))),
5405 Reason
=> CE_Range_Check_Failed
));
5406 end Silly_Boolean_Array_Xor_Test
;
5408 --------------------------
5409 -- Target_Has_Fixed_Ops --
5410 --------------------------
5412 Integer_Sized_Small
: Ureal
;
5413 -- Set to 2.0 ** -(Integer'Size - 1) the first time that this
5414 -- function is called (we don't want to compute it more than once!)
5416 Long_Integer_Sized_Small
: Ureal
;
5417 -- Set to 2.0 ** -(Long_Integer'Size - 1) the first time that this
5418 -- function is called (we don't want to compute it more than once)
5420 First_Time_For_THFO
: Boolean := True;
5421 -- Set to False after first call (if Fractional_Fixed_Ops_On_Target)
5423 function Target_Has_Fixed_Ops
5424 (Left_Typ
: Entity_Id
;
5425 Right_Typ
: Entity_Id
;
5426 Result_Typ
: Entity_Id
) return Boolean
5428 function Is_Fractional_Type
(Typ
: Entity_Id
) return Boolean;
5429 -- Return True if the given type is a fixed-point type with a small
5430 -- value equal to 2 ** (-(T'Object_Size - 1)) and whose values have
5431 -- an absolute value less than 1.0. This is currently limited
5432 -- to fixed-point types that map to Integer or Long_Integer.
5434 ------------------------
5435 -- Is_Fractional_Type --
5436 ------------------------
5438 function Is_Fractional_Type
(Typ
: Entity_Id
) return Boolean is
5440 if Esize
(Typ
) = Standard_Integer_Size
then
5441 return Small_Value
(Typ
) = Integer_Sized_Small
;
5443 elsif Esize
(Typ
) = Standard_Long_Integer_Size
then
5444 return Small_Value
(Typ
) = Long_Integer_Sized_Small
;
5449 end Is_Fractional_Type
;
5451 -- Start of processing for Target_Has_Fixed_Ops
5454 -- Return False if Fractional_Fixed_Ops_On_Target is false
5456 if not Fractional_Fixed_Ops_On_Target
then
5460 -- Here the target has Fractional_Fixed_Ops, if first time, compute
5461 -- standard constants used by Is_Fractional_Type.
5463 if First_Time_For_THFO
then
5464 First_Time_For_THFO
:= False;
5466 Integer_Sized_Small
:=
5469 Den
=> UI_From_Int
(Standard_Integer_Size
- 1),
5472 Long_Integer_Sized_Small
:=
5475 Den
=> UI_From_Int
(Standard_Long_Integer_Size
- 1),
5479 -- Return True if target supports fixed-by-fixed multiply/divide
5480 -- for fractional fixed-point types (see Is_Fractional_Type) and
5481 -- the operand and result types are equivalent fractional types.
5483 return Is_Fractional_Type
(Base_Type
(Left_Typ
))
5484 and then Is_Fractional_Type
(Base_Type
(Right_Typ
))
5485 and then Is_Fractional_Type
(Base_Type
(Result_Typ
))
5486 and then Esize
(Left_Typ
) = Esize
(Right_Typ
)
5487 and then Esize
(Left_Typ
) = Esize
(Result_Typ
);
5488 end Target_Has_Fixed_Ops
;
5490 ------------------------------------------
5491 -- Type_May_Have_Bit_Aligned_Components --
5492 ------------------------------------------
5494 function Type_May_Have_Bit_Aligned_Components
5495 (Typ
: Entity_Id
) return Boolean
5498 -- Array type, check component type
5500 if Is_Array_Type
(Typ
) then
5502 Type_May_Have_Bit_Aligned_Components
(Component_Type
(Typ
));
5504 -- Record type, check components
5506 elsif Is_Record_Type
(Typ
) then
5511 E
:= First_Component_Or_Discriminant
(Typ
);
5512 while Present
(E
) loop
5513 if Component_May_Be_Bit_Aligned
(E
)
5514 or else Type_May_Have_Bit_Aligned_Components
(Etype
(E
))
5519 Next_Component_Or_Discriminant
(E
);
5525 -- Type other than array or record is always OK
5530 end Type_May_Have_Bit_Aligned_Components
;
5532 ----------------------------
5533 -- Wrap_Cleanup_Procedure --
5534 ----------------------------
5536 procedure Wrap_Cleanup_Procedure
(N
: Node_Id
) is
5537 Loc
: constant Source_Ptr
:= Sloc
(N
);
5538 Stseq
: constant Node_Id
:= Handled_Statement_Sequence
(N
);
5539 Stmts
: constant List_Id
:= Statements
(Stseq
);
5542 if Abort_Allowed
then
5543 Prepend_To
(Stmts
, Build_Runtime_Call
(Loc
, RE_Abort_Defer
));
5544 Append_To
(Stmts
, Build_Runtime_Call
(Loc
, RE_Abort_Undefer
));
5546 end Wrap_Cleanup_Procedure
;