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