1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 2001-2012, 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 Errout
; use Errout
;
31 with Exp_Ch3
; use Exp_Ch3
;
32 with Exp_Util
; use Exp_Util
;
33 with Namet
; use Namet
;
34 with Nlists
; use Nlists
;
35 with Nmake
; use Nmake
;
37 with Repinfo
; use Repinfo
;
39 with Sem_Aux
; use Sem_Aux
;
40 with Sem_Ch13
; use Sem_Ch13
;
41 with Sem_Eval
; use Sem_Eval
;
42 with Sem_Util
; use Sem_Util
;
43 with Sinfo
; use Sinfo
;
44 with Snames
; use Snames
;
45 with Stand
; use Stand
;
46 with Targparm
; use Targparm
;
47 with Tbuild
; use Tbuild
;
48 with Ttypes
; use Ttypes
;
49 with Uintp
; use Uintp
;
51 package body Layout
is
53 ------------------------
54 -- Local Declarations --
55 ------------------------
57 SSU
: constant Int
:= Ttypes
.System_Storage_Unit
;
58 -- Short hand for System_Storage_Unit
60 Vname
: constant Name_Id
:= Name_uV
;
61 -- Formal parameter name used for functions generated for size offset
62 -- values that depend on the discriminant. All such functions have the
65 -- function xxx (V : vtyp) return Unsigned is
67 -- return ... expression involving V.discrim
70 -----------------------
71 -- Local Subprograms --
72 -----------------------
77 Right_Opnd
: Node_Id
) return Node_Id
;
78 -- This is like Make_Op_Add except that it optimizes some cases knowing
79 -- that associative rearrangement is allowed for constant folding if one
80 -- of the operands is a compile time known value.
82 function Assoc_Multiply
85 Right_Opnd
: Node_Id
) return Node_Id
;
86 -- This is like Make_Op_Multiply except that it optimizes some cases
87 -- knowing that associative rearrangement is allowed for constant folding
88 -- if one of the operands is a compile time known value
90 function Assoc_Subtract
93 Right_Opnd
: Node_Id
) return Node_Id
;
94 -- This is like Make_Op_Subtract except that it optimizes some cases
95 -- knowing that associative rearrangement is allowed for constant folding
96 -- if one of the operands is a compile time known value
98 function Bits_To_SU
(N
: Node_Id
) return Node_Id
;
99 -- This is used when we cross the boundary from static sizes in bits to
100 -- dynamic sizes in storage units. If the argument N is anything other
101 -- than an integer literal, it is returned unchanged, but if it is an
102 -- integer literal, then it is taken as a size in bits, and is replaced
103 -- by the corresponding size in storage units.
105 function Compute_Length
(Lo
: Node_Id
; Hi
: Node_Id
) return Node_Id
;
106 -- Given expressions for the low bound (Lo) and the high bound (Hi),
107 -- Build an expression for the value hi-lo+1, converted to type
108 -- Standard.Unsigned. Takes care of the case where the operands
109 -- are of an enumeration type (so that the subtraction cannot be
110 -- done directly) by applying the Pos operator to Hi/Lo first.
112 procedure Compute_Size_Depends_On_Discriminant
(E
: Entity_Id
);
113 -- Given an array type or an array subtype E, compute whether its size
114 -- depends on the value of one or more discriminants and set the flag
115 -- Size_Depends_On_Discriminant accordingly. This need not be called
116 -- in front end layout mode since it does the computation on its own.
118 function Expr_From_SO_Ref
121 Comp
: Entity_Id
:= Empty
) return Node_Id
;
122 -- Given a value D from a size or offset field, return an expression
123 -- representing the value stored. If the value is known at compile time,
124 -- then an N_Integer_Literal is returned with the appropriate value. If
125 -- the value references a constant entity, then an N_Identifier node
126 -- referencing this entity is returned. If the value denotes a size
127 -- function, then returns a call node denoting the given function, with
128 -- a single actual parameter that either refers to the parameter V of
129 -- an enclosing size function (if Comp is Empty or its type doesn't match
130 -- the function's formal), or else is a selected component V.c when Comp
131 -- denotes a component c whose type matches that of the function formal.
132 -- The Loc value is used for the Sloc value of constructed notes.
134 function SO_Ref_From_Expr
136 Ins_Type
: Entity_Id
;
137 Vtype
: Entity_Id
:= Empty
;
138 Make_Func
: Boolean := False) return Dynamic_SO_Ref
;
139 -- This routine is used in the case where a size/offset value is dynamic
140 -- and is represented by the expression Expr. SO_Ref_From_Expr checks if
141 -- the Expr contains a reference to the identifier V, and if so builds
142 -- a function depending on discriminants of the formal parameter V which
143 -- is of type Vtype. Otherwise, if the parameter Make_Func is True, then
144 -- Expr will be encapsulated in a parameterless function; if Make_Func is
145 -- False, then a constant entity with the value Expr is built. The result
146 -- is a Dynamic_SO_Ref to the created entity. Note that Vtype can be
147 -- omitted if Expr does not contain any reference to V, the created entity.
148 -- The declaration created is inserted in the freeze actions of Ins_Type,
149 -- which also supplies the Sloc for created nodes. This function also takes
150 -- care of making sure that the expression is properly analyzed and
151 -- resolved (which may not be the case yet if we build the expression
154 function Get_Max_SU_Size
(E
: Entity_Id
) return Node_Id
;
155 -- E is an array type or subtype that has at least one index bound that
156 -- is the value of a record discriminant. For such an array, the function
157 -- computes an expression that yields the maximum possible size of the
158 -- array in storage units. The result is not defined for any other type,
159 -- or for arrays that do not depend on discriminants, and it is a fatal
160 -- error to call this unless Size_Depends_On_Discriminant (E) is True.
162 procedure Layout_Array_Type
(E
: Entity_Id
);
163 -- Front-end layout of non-bit-packed array type or subtype
165 procedure Layout_Record_Type
(E
: Entity_Id
);
166 -- Front-end layout of record type
168 procedure Rewrite_Integer
(N
: Node_Id
; V
: Uint
);
169 -- Rewrite node N with an integer literal whose value is V. The Sloc for
170 -- the new node is taken from N, and the type of the literal is set to a
171 -- copy of the type of N on entry.
173 procedure Set_And_Check_Static_Size
177 -- This procedure is called to check explicit given sizes (possibly stored
178 -- in the Esize and RM_Size fields of E) against computed Object_Size
179 -- (Esiz) and Value_Size (RM_Siz) values. Appropriate errors and warnings
180 -- are posted if specified sizes are inconsistent with specified sizes. On
181 -- return, Esize and RM_Size fields of E are set (either from previously
182 -- given values, or from the newly computed values, as appropriate).
184 procedure Set_Composite_Alignment
(E
: Entity_Id
);
185 -- This procedure is called for record types and subtypes, and also for
186 -- atomic array types and subtypes. If no alignment is set, and the size
187 -- is 2 or 4 (or 8 if the word size is 8), then the alignment is set to
190 ----------------------------
191 -- Adjust_Esize_Alignment --
192 ----------------------------
194 procedure Adjust_Esize_Alignment
(E
: Entity_Id
) is
199 -- Nothing to do if size unknown
201 if Unknown_Esize
(E
) then
205 -- Determine if size is constrained by an attribute definition clause
206 -- which must be obeyed. If so, we cannot increase the size in this
209 -- For a type, the issue is whether an object size clause has been set.
210 -- A normal size clause constrains only the value size (RM_Size)
213 Esize_Set
:= Has_Object_Size_Clause
(E
);
215 -- For an object, the issue is whether a size clause is present
218 Esize_Set
:= Has_Size_Clause
(E
);
221 -- If size is known it must be a multiple of the storage unit size
223 if Esize
(E
) mod SSU
/= 0 then
225 -- If not, and size specified, then give error
229 ("size for& not a multiple of storage unit size",
233 -- Otherwise bump up size to a storage unit boundary
236 Set_Esize
(E
, (Esize
(E
) + SSU
- 1) / SSU
* SSU
);
240 -- Now we have the size set, it must be a multiple of the alignment
241 -- nothing more we can do here if the alignment is unknown here.
243 if Unknown_Alignment
(E
) then
247 -- At this point both the Esize and Alignment are known, so we need
248 -- to make sure they are consistent.
250 Abits
:= UI_To_Int
(Alignment
(E
)) * SSU
;
252 if Esize
(E
) mod Abits
= 0 then
256 -- Here we have a situation where the Esize is not a multiple of the
257 -- alignment. We must either increase Esize or reduce the alignment to
258 -- correct this situation.
260 -- The case in which we can decrease the alignment is where the
261 -- alignment was not set by an alignment clause, and the type in
262 -- question is a discrete type, where it is definitely safe to reduce
263 -- the alignment. For example:
265 -- t : integer range 1 .. 2;
268 -- In this situation, the initial alignment of t is 4, copied from
269 -- the Integer base type, but it is safe to reduce it to 1 at this
270 -- stage, since we will only be loading a single storage unit.
272 if Is_Discrete_Type
(Etype
(E
))
273 and then not Has_Alignment_Clause
(E
)
277 exit when Esize
(E
) mod Abits
= 0;
280 Init_Alignment
(E
, Abits
/ SSU
);
284 -- Now the only possible approach left is to increase the Esize but we
285 -- can't do that if the size was set by a specific clause.
289 ("size for& is not a multiple of alignment",
292 -- Otherwise we can indeed increase the size to a multiple of alignment
295 Set_Esize
(E
, ((Esize
(E
) + (Abits
- 1)) / Abits
) * Abits
);
297 end Adjust_Esize_Alignment
;
306 Right_Opnd
: Node_Id
) return Node_Id
312 -- Case of right operand is a constant
314 if Compile_Time_Known_Value
(Right_Opnd
) then
316 R
:= Expr_Value
(Right_Opnd
);
318 -- Case of left operand is a constant
320 elsif Compile_Time_Known_Value
(Left_Opnd
) then
322 R
:= Expr_Value
(Left_Opnd
);
324 -- Neither operand is a constant, do the addition with no optimization
327 return Make_Op_Add
(Loc
, Left_Opnd
, Right_Opnd
);
330 -- Case of left operand is an addition
332 if Nkind
(L
) = N_Op_Add
then
334 -- (C1 + E) + C2 = (C1 + C2) + E
336 if Compile_Time_Known_Value
(Sinfo
.Left_Opnd
(L
)) then
338 (Sinfo
.Left_Opnd
(L
),
339 Expr_Value
(Sinfo
.Left_Opnd
(L
)) + R
);
342 -- (E + C1) + C2 = E + (C1 + C2)
344 elsif Compile_Time_Known_Value
(Sinfo
.Right_Opnd
(L
)) then
346 (Sinfo
.Right_Opnd
(L
),
347 Expr_Value
(Sinfo
.Right_Opnd
(L
)) + R
);
351 -- Case of left operand is a subtraction
353 elsif Nkind
(L
) = N_Op_Subtract
then
355 -- (C1 - E) + C2 = (C1 + C2) + E
357 if Compile_Time_Known_Value
(Sinfo
.Left_Opnd
(L
)) then
359 (Sinfo
.Left_Opnd
(L
),
360 Expr_Value
(Sinfo
.Left_Opnd
(L
)) + R
);
363 -- (E - C1) + C2 = E - (C1 - C2)
365 elsif Compile_Time_Known_Value
(Sinfo
.Right_Opnd
(L
)) then
367 (Sinfo
.Right_Opnd
(L
),
368 Expr_Value
(Sinfo
.Right_Opnd
(L
)) - R
);
373 -- Not optimizable, do the addition
375 return Make_Op_Add
(Loc
, Left_Opnd
, Right_Opnd
);
382 function Assoc_Multiply
385 Right_Opnd
: Node_Id
) return Node_Id
391 -- Case of right operand is a constant
393 if Compile_Time_Known_Value
(Right_Opnd
) then
395 R
:= Expr_Value
(Right_Opnd
);
397 -- Case of left operand is a constant
399 elsif Compile_Time_Known_Value
(Left_Opnd
) then
401 R
:= Expr_Value
(Left_Opnd
);
403 -- Neither operand is a constant, do the multiply with no optimization
406 return Make_Op_Multiply
(Loc
, Left_Opnd
, Right_Opnd
);
409 -- Case of left operand is an multiplication
411 if Nkind
(L
) = N_Op_Multiply
then
413 -- (C1 * E) * C2 = (C1 * C2) + E
415 if Compile_Time_Known_Value
(Sinfo
.Left_Opnd
(L
)) then
417 (Sinfo
.Left_Opnd
(L
),
418 Expr_Value
(Sinfo
.Left_Opnd
(L
)) * R
);
421 -- (E * C1) * C2 = E * (C1 * C2)
423 elsif Compile_Time_Known_Value
(Sinfo
.Right_Opnd
(L
)) then
425 (Sinfo
.Right_Opnd
(L
),
426 Expr_Value
(Sinfo
.Right_Opnd
(L
)) * R
);
431 -- Not optimizable, do the multiplication
433 return Make_Op_Multiply
(Loc
, Left_Opnd
, Right_Opnd
);
440 function Assoc_Subtract
443 Right_Opnd
: Node_Id
) return Node_Id
449 -- Case of right operand is a constant
451 if Compile_Time_Known_Value
(Right_Opnd
) then
453 R
:= Expr_Value
(Right_Opnd
);
455 -- Right operand is a constant, do the subtract with no optimization
458 return Make_Op_Subtract
(Loc
, Left_Opnd
, Right_Opnd
);
461 -- Case of left operand is an addition
463 if Nkind
(L
) = N_Op_Add
then
465 -- (C1 + E) - C2 = (C1 - C2) + E
467 if Compile_Time_Known_Value
(Sinfo
.Left_Opnd
(L
)) then
469 (Sinfo
.Left_Opnd
(L
),
470 Expr_Value
(Sinfo
.Left_Opnd
(L
)) - R
);
473 -- (E + C1) - C2 = E + (C1 - C2)
475 elsif Compile_Time_Known_Value
(Sinfo
.Right_Opnd
(L
)) then
477 (Sinfo
.Right_Opnd
(L
),
478 Expr_Value
(Sinfo
.Right_Opnd
(L
)) - R
);
482 -- Case of left operand is a subtraction
484 elsif Nkind
(L
) = N_Op_Subtract
then
486 -- (C1 - E) - C2 = (C1 - C2) + E
488 if Compile_Time_Known_Value
(Sinfo
.Left_Opnd
(L
)) then
490 (Sinfo
.Left_Opnd
(L
),
491 Expr_Value
(Sinfo
.Left_Opnd
(L
)) + R
);
494 -- (E - C1) - C2 = E - (C1 + C2)
496 elsif Compile_Time_Known_Value
(Sinfo
.Right_Opnd
(L
)) then
498 (Sinfo
.Right_Opnd
(L
),
499 Expr_Value
(Sinfo
.Right_Opnd
(L
)) + R
);
504 -- Not optimizable, do the subtraction
506 return Make_Op_Subtract
(Loc
, Left_Opnd
, Right_Opnd
);
513 function Bits_To_SU
(N
: Node_Id
) return Node_Id
is
515 if Nkind
(N
) = N_Integer_Literal
then
516 Set_Intval
(N
, (Intval
(N
) + (SSU
- 1)) / SSU
);
526 function Compute_Length
(Lo
: Node_Id
; Hi
: Node_Id
) return Node_Id
is
527 Loc
: constant Source_Ptr
:= Sloc
(Lo
);
528 Typ
: constant Entity_Id
:= Etype
(Lo
);
535 -- If the bounds are First and Last attributes for the same dimension
536 -- and both have prefixes that denotes the same entity, then we create
537 -- and return a Length attribute. This may allow the back end to
538 -- generate better code in cases where it already has the length.
540 if Nkind
(Lo
) = N_Attribute_Reference
541 and then Attribute_Name
(Lo
) = Name_First
542 and then Nkind
(Hi
) = N_Attribute_Reference
543 and then Attribute_Name
(Hi
) = Name_Last
544 and then Is_Entity_Name
(Prefix
(Lo
))
545 and then Is_Entity_Name
(Prefix
(Hi
))
546 and then Entity
(Prefix
(Lo
)) = Entity
(Prefix
(Hi
))
551 if Present
(First
(Expressions
(Lo
))) then
552 Lo_Dim
:= Expr_Value
(First
(Expressions
(Lo
)));
555 if Present
(First
(Expressions
(Hi
))) then
556 Hi_Dim
:= Expr_Value
(First
(Expressions
(Hi
)));
559 if Lo_Dim
= Hi_Dim
then
561 Make_Attribute_Reference
(Loc
,
562 Prefix
=> New_Occurrence_Of
563 (Entity
(Prefix
(Lo
)), Loc
),
564 Attribute_Name
=> Name_Length
,
565 Expressions
=> New_List
566 (Make_Integer_Literal
(Loc
, Lo_Dim
)));
570 Lo_Op
:= New_Copy_Tree
(Lo
);
571 Hi_Op
:= New_Copy_Tree
(Hi
);
573 -- If type is enumeration type, then use Pos attribute to convert
574 -- to integer type for which subtraction is a permitted operation.
576 if Is_Enumeration_Type
(Typ
) then
578 Make_Attribute_Reference
(Loc
,
579 Prefix
=> New_Occurrence_Of
(Typ
, Loc
),
580 Attribute_Name
=> Name_Pos
,
581 Expressions
=> New_List
(Lo_Op
));
584 Make_Attribute_Reference
(Loc
,
585 Prefix
=> New_Occurrence_Of
(Typ
, Loc
),
586 Attribute_Name
=> Name_Pos
,
587 Expressions
=> New_List
(Hi_Op
));
595 Right_Opnd
=> Lo_Op
),
596 Right_Opnd
=> Make_Integer_Literal
(Loc
, 1));
599 ----------------------
600 -- Expr_From_SO_Ref --
601 ----------------------
603 function Expr_From_SO_Ref
606 Comp
: Entity_Id
:= Empty
) return Node_Id
611 if Is_Dynamic_SO_Ref
(D
) then
612 Ent
:= Get_Dynamic_SO_Entity
(D
);
614 if Is_Discrim_SO_Function
(Ent
) then
616 -- If a component is passed in whose type matches the type of
617 -- the function formal, then select that component from the "V"
618 -- parameter rather than passing "V" directly.
621 and then Base_Type
(Etype
(Comp
))
622 = Base_Type
(Etype
(First_Formal
(Ent
)))
625 Make_Function_Call
(Loc
,
626 Name
=> New_Occurrence_Of
(Ent
, Loc
),
627 Parameter_Associations
=> New_List
(
628 Make_Selected_Component
(Loc
,
629 Prefix
=> Make_Identifier
(Loc
, Vname
),
630 Selector_Name
=> New_Occurrence_Of
(Comp
, Loc
))));
634 Make_Function_Call
(Loc
,
635 Name
=> New_Occurrence_Of
(Ent
, Loc
),
636 Parameter_Associations
=> New_List
(
637 Make_Identifier
(Loc
, Vname
)));
641 return New_Occurrence_Of
(Ent
, Loc
);
645 return Make_Integer_Literal
(Loc
, D
);
647 end Expr_From_SO_Ref
;
649 ---------------------
650 -- Get_Max_SU_Size --
651 ---------------------
653 function Get_Max_SU_Size
(E
: Entity_Id
) return Node_Id
is
654 Loc
: constant Source_Ptr
:= Sloc
(E
);
662 type Val_Status_Type
is (Const
, Dynamic
);
664 type Val_Type
(Status
: Val_Status_Type
:= Const
) is
667 when Const
=> Val
: Uint
;
668 when Dynamic
=> Nod
: Node_Id
;
671 -- Shows the status of the value so far. Const means that the value is
672 -- constant, and Val is the current constant value. Dynamic means that
673 -- the value is dynamic, and in this case Nod is the Node_Id of the
674 -- expression to compute the value.
677 -- Calculated value so far if Size.Status = Const,
678 -- or expression value so far if Size.Status = Dynamic.
680 SU_Convert_Required
: Boolean := False;
681 -- This is set to True if the final result must be converted from bits
682 -- to storage units (rounding up to a storage unit boundary).
684 -----------------------
685 -- Local Subprograms --
686 -----------------------
688 procedure Max_Discrim
(N
: in out Node_Id
);
689 -- If the node N represents a discriminant, replace it by the maximum
690 -- value of the discriminant.
692 procedure Min_Discrim
(N
: in out Node_Id
);
693 -- If the node N represents a discriminant, replace it by the minimum
694 -- value of the discriminant.
700 procedure Max_Discrim
(N
: in out Node_Id
) is
702 if Nkind
(N
) = N_Identifier
703 and then Ekind
(Entity
(N
)) = E_Discriminant
705 N
:= Type_High_Bound
(Etype
(N
));
713 procedure Min_Discrim
(N
: in out Node_Id
) is
715 if Nkind
(N
) = N_Identifier
716 and then Ekind
(Entity
(N
)) = E_Discriminant
718 N
:= Type_Low_Bound
(Etype
(N
));
722 -- Start of processing for Get_Max_SU_Size
725 pragma Assert
(Size_Depends_On_Discriminant
(E
));
727 -- Initialize status from component size
729 if Known_Static_Component_Size
(E
) then
730 Size
:= (Const
, Component_Size
(E
));
733 Size
:= (Dynamic
, Expr_From_SO_Ref
(Loc
, Component_Size
(E
)));
736 -- Loop through indexes
738 Indx
:= First_Index
(E
);
739 while Present
(Indx
) loop
740 Ityp
:= Etype
(Indx
);
741 Lo
:= Type_Low_Bound
(Ityp
);
742 Hi
:= Type_High_Bound
(Ityp
);
747 -- Value of the current subscript range is statically known
749 if Compile_Time_Known_Value
(Lo
)
750 and then Compile_Time_Known_Value
(Hi
)
752 S
:= Expr_Value
(Hi
) - Expr_Value
(Lo
) + 1;
754 -- If known flat bound, entire size of array is zero!
757 return Make_Integer_Literal
(Loc
, 0);
760 -- Current value is constant, evolve value
762 if Size
.Status
= Const
then
763 Size
.Val
:= Size
.Val
* S
;
765 -- Current value is dynamic
768 -- An interesting little optimization, if we have a pending
769 -- conversion from bits to storage units, and the current
770 -- length is a multiple of the storage unit size, then we
771 -- can take the factor out here statically, avoiding some
772 -- extra dynamic computations at the end.
774 if SU_Convert_Required
and then S
mod SSU
= 0 then
776 SU_Convert_Required
:= False;
781 Left_Opnd
=> Size
.Nod
,
783 Make_Integer_Literal
(Loc
, Intval
=> S
));
786 -- Value of the current subscript range is dynamic
789 -- If the current size value is constant, then here is where we
790 -- make a transition to dynamic values, which are always stored
791 -- in storage units, However, we do not want to convert to SU's
792 -- too soon, consider the case of a packed array of single bits,
793 -- we want to do the SU conversion after computing the size in
796 if Size
.Status
= Const
then
798 -- If the current value is a multiple of the storage unit,
799 -- then most certainly we can do the conversion now, simply
800 -- by dividing the current value by the storage unit value.
801 -- If this works, we set SU_Convert_Required to False.
803 if Size
.Val
mod SSU
= 0 then
806 (Dynamic
, Make_Integer_Literal
(Loc
, Size
.Val
/ SSU
));
807 SU_Convert_Required
:= False;
809 -- Otherwise, we go ahead and convert the value in bits, and
810 -- set SU_Convert_Required to True to ensure that the final
811 -- value is indeed properly converted.
814 Size
:= (Dynamic
, Make_Integer_Literal
(Loc
, Size
.Val
));
815 SU_Convert_Required
:= True;
821 Len
:= Compute_Length
(Lo
, Hi
);
823 -- Check possible range of Len
829 pragma Warnings
(Off
, LHi
);
833 Determine_Range
(Len
, OK
, LLo
, LHi
);
835 Len
:= Convert_To
(Standard_Unsigned
, Len
);
837 -- If we cannot verify that range cannot be super-flat, we need
838 -- a max with zero, since length must be non-negative.
840 if not OK
or else LLo
< 0 then
842 Make_Attribute_Reference
(Loc
,
844 New_Occurrence_Of
(Standard_Unsigned
, Loc
),
845 Attribute_Name
=> Name_Max
,
846 Expressions
=> New_List
(
847 Make_Integer_Literal
(Loc
, 0),
856 -- Here after processing all bounds to set sizes. If the value is a
857 -- constant, then it is bits, so we convert to storage units.
859 if Size
.Status
= Const
then
860 return Bits_To_SU
(Make_Integer_Literal
(Loc
, Size
.Val
));
862 -- Case where the value is dynamic
865 -- Do convert from bits to SU's if needed
867 if SU_Convert_Required
then
869 -- The expression required is (Size.Nod + SU - 1) / SU
875 Left_Opnd
=> Size
.Nod
,
876 Right_Opnd
=> Make_Integer_Literal
(Loc
, SSU
- 1)),
877 Right_Opnd
=> Make_Integer_Literal
(Loc
, SSU
));
884 -----------------------
885 -- Layout_Array_Type --
886 -----------------------
888 procedure Layout_Array_Type
(E
: Entity_Id
) is
889 Loc
: constant Source_Ptr
:= Sloc
(E
);
890 Ctyp
: constant Entity_Id
:= Component_Type
(E
);
898 Insert_Typ
: Entity_Id
;
899 -- This is the type with which any generated constants or functions
900 -- will be associated (i.e. inserted into the freeze actions). This
901 -- is normally the type being laid out. The exception occurs when
902 -- we are laying out Itype's which are local to a record type, and
903 -- whose scope is this record type. Such types do not have freeze
904 -- nodes (because we have no place to put them).
906 ------------------------------------
907 -- How An Array Type is Laid Out --
908 ------------------------------------
910 -- Here is what goes on. We need to multiply the component size of the
911 -- array (which has already been set) by the length of each of the
912 -- indexes. If all these values are known at compile time, then the
913 -- resulting size of the array is the appropriate constant value.
915 -- If the component size or at least one bound is dynamic (but no
916 -- discriminants are present), then the size will be computed as an
917 -- expression that calculates the proper size.
919 -- If there is at least one discriminant bound, then the size is also
920 -- computed as an expression, but this expression contains discriminant
921 -- values which are obtained by selecting from a function parameter, and
922 -- the size is given by a function that is passed the variant record in
923 -- question, and whose body is the expression.
925 type Val_Status_Type
is (Const
, Dynamic
, Discrim
);
927 type Val_Type
(Status
: Val_Status_Type
:= Const
) is
932 -- Calculated value so far if Val_Status = Const
934 when Dynamic | Discrim
=>
936 -- Expression value so far if Val_Status /= Const
940 -- Records the value or expression computed so far. Const means that
941 -- the value is constant, and Val is the current constant value.
942 -- Dynamic means that the value is dynamic, and in this case Nod is
943 -- the Node_Id of the expression to compute the value, and Discrim
944 -- means that at least one bound is a discriminant, in which case Nod
945 -- is the expression so far (which will be the body of the function).
948 -- Value of size computed so far. See comments above
950 Vtyp
: Entity_Id
:= Empty
;
951 -- Variant record type for the formal parameter of the discriminant
952 -- function V if Status = Discrim.
954 SU_Convert_Required
: Boolean := False;
955 -- This is set to True if the final result must be converted from
956 -- bits to storage units (rounding up to a storage unit boundary).
958 Storage_Divisor
: Uint
:= UI_From_Int
(SSU
);
959 -- This is the amount that a nonstatic computed size will be divided
960 -- by to convert it from bits to storage units. This is normally
961 -- equal to SSU, but can be reduced in the case of packed components
962 -- that fit evenly into a storage unit.
964 Make_Size_Function
: Boolean := False;
965 -- Indicates whether to request that SO_Ref_From_Expr should
966 -- encapsulate the array size expression in a function.
968 procedure Discrimify
(N
: in out Node_Id
);
969 -- If N represents a discriminant, then the Size.Status is set to
970 -- Discrim, and Vtyp is set. The parameter N is replaced with the
971 -- proper expression to extract the discriminant value from V.
977 procedure Discrimify
(N
: in out Node_Id
) is
982 if Nkind
(N
) = N_Identifier
983 and then Ekind
(Entity
(N
)) = E_Discriminant
985 Set_Size_Depends_On_Discriminant
(E
);
987 if Size
.Status
/= Discrim
then
988 Decl
:= Parent
(Parent
(Entity
(N
)));
989 Size
:= (Discrim
, Size
.Nod
);
990 Vtyp
:= Defining_Identifier
(Decl
);
996 Make_Selected_Component
(Loc
,
997 Prefix
=> Make_Identifier
(Loc
, Vname
),
998 Selector_Name
=> New_Occurrence_Of
(Entity
(N
), Loc
));
1000 -- Set the Etype attributes of the selected name and its prefix.
1001 -- Analyze_And_Resolve can't be called here because the Vname
1002 -- entity denoted by the prefix will not yet exist (it's created
1003 -- by SO_Ref_From_Expr, called at the end of Layout_Array_Type).
1005 Set_Etype
(Prefix
(N
), Vtyp
);
1010 -- Start of processing for Layout_Array_Type
1013 -- Default alignment is component alignment
1015 if Unknown_Alignment
(E
) then
1016 Set_Alignment
(E
, Alignment
(Ctyp
));
1019 -- Calculate proper type for insertions
1021 if Is_Record_Type
(Underlying_Type
(Scope
(E
))) then
1022 Insert_Typ
:= Underlying_Type
(Scope
(E
));
1027 -- If the component type is a generic formal type then there's no point
1028 -- in determining a size for the array type.
1030 if Is_Generic_Type
(Ctyp
) then
1034 -- Deal with component size if base type
1036 if Ekind
(E
) = E_Array_Type
then
1038 -- Cannot do anything if Esize of component type unknown
1040 if Unknown_Esize
(Ctyp
) then
1044 -- Set component size if not set already
1046 if Unknown_Component_Size
(E
) then
1047 Set_Component_Size
(E
, Esize
(Ctyp
));
1051 -- (RM 13.3 (48)) says that the size of an unconstrained array
1052 -- is implementation defined. We choose to leave it as Unknown
1053 -- here, and the actual behavior is determined by the back end.
1055 if not Is_Constrained
(E
) then
1059 -- Initialize status from component size
1061 if Known_Static_Component_Size
(E
) then
1062 Size
:= (Const
, Component_Size
(E
));
1065 Size
:= (Dynamic
, Expr_From_SO_Ref
(Loc
, Component_Size
(E
)));
1068 -- Loop to process array indexes
1070 Indx
:= First_Index
(E
);
1071 while Present
(Indx
) loop
1072 Ityp
:= Etype
(Indx
);
1074 -- If an index of the array is a generic formal type then there is
1075 -- no point in determining a size for the array type.
1077 if Is_Generic_Type
(Ityp
) then
1081 Lo
:= Type_Low_Bound
(Ityp
);
1082 Hi
:= Type_High_Bound
(Ityp
);
1084 -- Value of the current subscript range is statically known
1086 if Compile_Time_Known_Value
(Lo
)
1087 and then Compile_Time_Known_Value
(Hi
)
1089 S
:= Expr_Value
(Hi
) - Expr_Value
(Lo
) + 1;
1091 -- If known flat bound, entire size of array is zero!
1094 Set_Esize
(E
, Uint_0
);
1095 Set_RM_Size
(E
, Uint_0
);
1099 -- If constant, evolve value
1101 if Size
.Status
= Const
then
1102 Size
.Val
:= Size
.Val
* S
;
1104 -- Current value is dynamic
1107 -- An interesting little optimization, if we have a pending
1108 -- conversion from bits to storage units, and the current
1109 -- length is a multiple of the storage unit size, then we
1110 -- can take the factor out here statically, avoiding some
1111 -- extra dynamic computations at the end.
1113 if SU_Convert_Required
and then S
mod SSU
= 0 then
1115 SU_Convert_Required
:= False;
1118 -- Now go ahead and evolve the expression
1121 Assoc_Multiply
(Loc
,
1122 Left_Opnd
=> Size
.Nod
,
1124 Make_Integer_Literal
(Loc
, Intval
=> S
));
1127 -- Value of the current subscript range is dynamic
1130 -- If the current size value is constant, then here is where we
1131 -- make a transition to dynamic values, which are always stored
1132 -- in storage units, However, we do not want to convert to SU's
1133 -- too soon, consider the case of a packed array of single bits,
1134 -- we want to do the SU conversion after computing the size in
1137 if Size
.Status
= Const
then
1139 -- If the current value is a multiple of the storage unit,
1140 -- then most certainly we can do the conversion now, simply
1141 -- by dividing the current value by the storage unit value.
1142 -- If this works, we set SU_Convert_Required to False.
1144 if Size
.Val
mod SSU
= 0 then
1146 (Dynamic
, Make_Integer_Literal
(Loc
, Size
.Val
/ SSU
));
1147 SU_Convert_Required
:= False;
1149 -- If the current value is a factor of the storage unit, then
1150 -- we can use a value of one for the size and reduce the
1151 -- strength of the later division.
1153 elsif SSU
mod Size
.Val
= 0 then
1154 Storage_Divisor
:= SSU
/ Size
.Val
;
1155 Size
:= (Dynamic
, Make_Integer_Literal
(Loc
, Uint_1
));
1156 SU_Convert_Required
:= True;
1158 -- Otherwise, we go ahead and convert the value in bits, and
1159 -- set SU_Convert_Required to True to ensure that the final
1160 -- value is indeed properly converted.
1163 Size
:= (Dynamic
, Make_Integer_Literal
(Loc
, Size
.Val
));
1164 SU_Convert_Required
:= True;
1171 -- Length is hi-lo+1
1173 Len
:= Compute_Length
(Lo
, Hi
);
1175 -- If Len isn't a Length attribute, then its range needs to be
1176 -- checked a possible Max with zero needs to be computed.
1178 if Nkind
(Len
) /= N_Attribute_Reference
1179 or else Attribute_Name
(Len
) /= Name_Length
1187 -- Check possible range of Len
1189 Set_Parent
(Len
, E
);
1190 Determine_Range
(Len
, OK
, LLo
, LHi
);
1192 Len
:= Convert_To
(Standard_Unsigned
, Len
);
1194 -- If range definitely flat or superflat,
1195 -- result size is zero
1197 if OK
and then LHi
<= 0 then
1198 Set_Esize
(E
, Uint_0
);
1199 Set_RM_Size
(E
, Uint_0
);
1203 -- If we cannot verify that range cannot be super-flat, we
1204 -- need a max with zero, since length cannot be negative.
1206 if not OK
or else LLo
< 0 then
1208 Make_Attribute_Reference
(Loc
,
1210 New_Occurrence_Of
(Standard_Unsigned
, Loc
),
1211 Attribute_Name
=> Name_Max
,
1212 Expressions
=> New_List
(
1213 Make_Integer_Literal
(Loc
, 0),
1219 -- At this stage, Len has the expression for the length
1222 Assoc_Multiply
(Loc
,
1223 Left_Opnd
=> Size
.Nod
,
1230 -- Here after processing all bounds to set sizes. If the value is a
1231 -- constant, then it is bits, and the only thing we need to do is to
1232 -- check against explicit given size and do alignment adjust.
1234 if Size
.Status
= Const
then
1235 Set_And_Check_Static_Size
(E
, Size
.Val
, Size
.Val
);
1236 Adjust_Esize_Alignment
(E
);
1238 -- Case where the value is dynamic
1241 -- Do convert from bits to SU's if needed
1243 if SU_Convert_Required
then
1245 -- The expression required is:
1246 -- (Size.Nod + Storage_Divisor - 1) / Storage_Divisor
1249 Make_Op_Divide
(Loc
,
1252 Left_Opnd
=> Size
.Nod
,
1253 Right_Opnd
=> Make_Integer_Literal
1254 (Loc
, Storage_Divisor
- 1)),
1255 Right_Opnd
=> Make_Integer_Literal
(Loc
, Storage_Divisor
));
1258 -- If the array entity is not declared at the library level and its
1259 -- not nested within a subprogram that is marked for inlining, then
1260 -- we request that the size expression be encapsulated in a function.
1261 -- Since this expression is not needed in most cases, we prefer not
1262 -- to incur the overhead of the computation on calls to the enclosing
1263 -- subprogram except for subprograms that require the size.
1265 if not Is_Library_Level_Entity
(E
) then
1266 Make_Size_Function
:= True;
1269 Parent_Subp
: Entity_Id
:= Enclosing_Subprogram
(E
);
1272 while Present
(Parent_Subp
) loop
1273 if Is_Inlined
(Parent_Subp
) then
1274 Make_Size_Function
:= False;
1278 Parent_Subp
:= Enclosing_Subprogram
(Parent_Subp
);
1283 -- Now set the dynamic size (the Value_Size is always the same as the
1284 -- Object_Size for arrays whose length is dynamic).
1286 -- ??? If Size.Status = Dynamic, Vtyp will not have been set.
1287 -- The added initialization sets it to Empty now, but is this
1293 (Size
.Nod
, Insert_Typ
, Vtyp
, Make_Func
=> Make_Size_Function
));
1294 Set_RM_Size
(E
, Esize
(E
));
1296 end Layout_Array_Type
;
1298 ------------------------------------------
1299 -- Compute_Size_Depends_On_Discriminant --
1300 ------------------------------------------
1302 procedure Compute_Size_Depends_On_Discriminant
(E
: Entity_Id
) is
1307 Res
: Boolean := False;
1310 -- Loop to process array indexes
1312 Indx
:= First_Index
(E
);
1313 while Present
(Indx
) loop
1314 Ityp
:= Etype
(Indx
);
1316 -- If an index of the array is a generic formal type then there is
1317 -- no point in determining a size for the array type.
1319 if Is_Generic_Type
(Ityp
) then
1323 Lo
:= Type_Low_Bound
(Ityp
);
1324 Hi
:= Type_High_Bound
(Ityp
);
1326 if (Nkind
(Lo
) = N_Identifier
1327 and then Ekind
(Entity
(Lo
)) = E_Discriminant
)
1329 (Nkind
(Hi
) = N_Identifier
1330 and then Ekind
(Entity
(Hi
)) = E_Discriminant
)
1339 Set_Size_Depends_On_Discriminant
(E
);
1341 end Compute_Size_Depends_On_Discriminant
;
1347 procedure Layout_Object
(E
: Entity_Id
) is
1348 T
: constant Entity_Id
:= Etype
(E
);
1351 -- Nothing to do if backend does layout
1353 if not Frontend_Layout_On_Target
then
1357 -- Set size if not set for object and known for type. Use the RM_Size if
1358 -- that is known for the type and Esize is not.
1360 if Unknown_Esize
(E
) then
1361 if Known_Esize
(T
) then
1362 Set_Esize
(E
, Esize
(T
));
1364 elsif Known_RM_Size
(T
) then
1365 Set_Esize
(E
, RM_Size
(T
));
1369 -- Set alignment from type if unknown and type alignment known
1371 if Unknown_Alignment
(E
) and then Known_Alignment
(T
) then
1372 Set_Alignment
(E
, Alignment
(T
));
1375 -- Make sure size and alignment are consistent
1377 Adjust_Esize_Alignment
(E
);
1379 -- Final adjustment, if we don't know the alignment, and the Esize was
1380 -- not set by an explicit Object_Size attribute clause, then we reset
1381 -- the Esize to unknown, since we really don't know it.
1383 if Unknown_Alignment
(E
)
1384 and then not Has_Size_Clause
(E
)
1386 Set_Esize
(E
, Uint_0
);
1390 ------------------------
1391 -- Layout_Record_Type --
1392 ------------------------
1394 procedure Layout_Record_Type
(E
: Entity_Id
) is
1395 Loc
: constant Source_Ptr
:= Sloc
(E
);
1399 -- Current component being laid out
1401 Prev_Comp
: Entity_Id
;
1402 -- Previous laid out component
1404 procedure Get_Next_Component_Location
1405 (Prev_Comp
: Entity_Id
;
1407 New_Npos
: out SO_Ref
;
1408 New_Fbit
: out SO_Ref
;
1409 New_NPMax
: out SO_Ref
;
1410 Force_SU
: Boolean);
1411 -- Given the previous component in Prev_Comp, which is already laid
1412 -- out, and the alignment of the following component, lays out the
1413 -- following component, and returns its starting position in New_Npos
1414 -- (Normalized_Position value), New_Fbit (Normalized_First_Bit value),
1415 -- and New_NPMax (Normalized_Position_Max value). If Prev_Comp is empty
1416 -- (no previous component is present), then New_Npos, New_Fbit and
1417 -- New_NPMax are all set to zero on return. This procedure is also
1418 -- used to compute the size of a record or variant by giving it the
1419 -- last component, and the record alignment. Force_SU is used to force
1420 -- the new component location to be aligned on a storage unit boundary,
1421 -- even in a packed record, False means that the new position does not
1422 -- need to be bumped to a storage unit boundary, True means a storage
1423 -- unit boundary is always required.
1425 procedure Layout_Component
(Comp
: Entity_Id
; Prev_Comp
: Entity_Id
);
1426 -- Lays out component Comp, given Prev_Comp, the previously laid-out
1427 -- component (Prev_Comp = Empty if no components laid out yet). The
1428 -- alignment of the record itself is also updated if needed. Both
1429 -- Comp and Prev_Comp can be either components or discriminants.
1431 procedure Layout_Components
1435 RM_Siz
: out SO_Ref
);
1436 -- This procedure lays out the components of the given component list
1437 -- which contains the components starting with From and ending with To.
1438 -- The Next_Entity chain is used to traverse the components. On entry,
1439 -- Prev_Comp is set to the component preceding the list, so that the
1440 -- list is laid out after this component. Prev_Comp is set to Empty if
1441 -- the component list is to be laid out starting at the start of the
1442 -- record. On return, the components are all laid out, and Prev_Comp is
1443 -- set to the last laid out component. On return, Esiz is set to the
1444 -- resulting Object_Size value, which is the length of the record up
1445 -- to and including the last laid out entity. For Esiz, the value is
1446 -- adjusted to match the alignment of the record. RM_Siz is similarly
1447 -- set to the resulting Value_Size value, which is the same length, but
1448 -- not adjusted to meet the alignment. Note that in the case of variant
1449 -- records, Esiz represents the maximum size.
1451 procedure Layout_Non_Variant_Record
;
1452 -- Procedure called to lay out a non-variant record type or subtype
1454 procedure Layout_Variant_Record
;
1455 -- Procedure called to lay out a variant record type. Decl is set to the
1456 -- full type declaration for the variant record.
1458 ---------------------------------
1459 -- Get_Next_Component_Location --
1460 ---------------------------------
1462 procedure Get_Next_Component_Location
1463 (Prev_Comp
: Entity_Id
;
1465 New_Npos
: out SO_Ref
;
1466 New_Fbit
: out SO_Ref
;
1467 New_NPMax
: out SO_Ref
;
1471 -- No previous component, return zero position
1473 if No
(Prev_Comp
) then
1476 New_NPMax
:= Uint_0
;
1480 -- Here we have a previous component
1483 Loc
: constant Source_Ptr
:= Sloc
(Prev_Comp
);
1485 Old_Npos
: constant SO_Ref
:= Normalized_Position
(Prev_Comp
);
1486 Old_Fbit
: constant SO_Ref
:= Normalized_First_Bit
(Prev_Comp
);
1487 Old_NPMax
: constant SO_Ref
:= Normalized_Position_Max
(Prev_Comp
);
1488 Old_Esiz
: constant SO_Ref
:= Esize
(Prev_Comp
);
1490 Old_Maxsz
: Node_Id
;
1491 -- Expression representing maximum size of previous component
1494 -- Case where previous field had a dynamic size
1496 if Is_Dynamic_SO_Ref
(Esize
(Prev_Comp
)) then
1498 -- If the previous field had a dynamic length, then it is
1499 -- required to occupy an integral number of storage units,
1500 -- and start on a storage unit boundary. This means that
1501 -- the Normalized_First_Bit value is zero in the previous
1502 -- component, and the new value is also set to zero.
1506 -- In this case, the new position is given by an expression
1507 -- that is the sum of old normalized position and old size.
1513 Expr_From_SO_Ref
(Loc
, Old_Npos
),
1515 Expr_From_SO_Ref
(Loc
, Old_Esiz
, Prev_Comp
)),
1519 -- Get maximum size of previous component
1521 if Size_Depends_On_Discriminant
(Etype
(Prev_Comp
)) then
1522 Old_Maxsz
:= Get_Max_SU_Size
(Etype
(Prev_Comp
));
1524 Old_Maxsz
:= Expr_From_SO_Ref
(Loc
, Old_Esiz
, Prev_Comp
);
1527 -- Now we can compute the new max position. If the max size
1528 -- is static and the old position is static, then we can
1529 -- compute the new position statically.
1531 if Nkind
(Old_Maxsz
) = N_Integer_Literal
1532 and then Known_Static_Normalized_Position_Max
(Prev_Comp
)
1534 New_NPMax
:= Old_NPMax
+ Intval
(Old_Maxsz
);
1536 -- Otherwise new max position is dynamic
1542 Left_Opnd
=> Expr_From_SO_Ref
(Loc
, Old_NPMax
),
1543 Right_Opnd
=> Old_Maxsz
),
1548 -- Previous field has known static Esize
1551 New_Fbit
:= Old_Fbit
+ Old_Esiz
;
1553 -- Bump New_Fbit to storage unit boundary if required
1555 if New_Fbit
/= 0 and then Force_SU
then
1556 New_Fbit
:= (New_Fbit
+ SSU
- 1) / SSU
* SSU
;
1559 -- If old normalized position is static, we can go ahead and
1560 -- compute the new normalized position directly.
1562 if Known_Static_Normalized_Position
(Prev_Comp
) then
1563 New_Npos
:= Old_Npos
;
1565 if New_Fbit
>= SSU
then
1566 New_Npos
:= New_Npos
+ New_Fbit
/ SSU
;
1567 New_Fbit
:= New_Fbit
mod SSU
;
1570 -- Bump alignment if stricter than prev
1572 if Align
> Alignment
(Etype
(Prev_Comp
)) then
1573 New_Npos
:= (New_Npos
+ Align
- 1) / Align
* Align
;
1576 -- The max position is always equal to the position if
1577 -- the latter is static, since arrays depending on the
1578 -- values of discriminants never have static sizes.
1580 New_NPMax
:= New_Npos
;
1583 -- Case of old normalized position is dynamic
1586 -- If new bit position is within the current storage unit,
1587 -- we can just copy the old position as the result position
1588 -- (we have already set the new first bit value).
1590 if New_Fbit
< SSU
then
1591 New_Npos
:= Old_Npos
;
1592 New_NPMax
:= Old_NPMax
;
1594 -- If new bit position is past the current storage unit, we
1595 -- need to generate a new dynamic value for the position
1596 -- ??? need to deal with alignment
1602 Left_Opnd
=> Expr_From_SO_Ref
(Loc
, Old_Npos
),
1604 Make_Integer_Literal
(Loc
,
1605 Intval
=> New_Fbit
/ SSU
)),
1612 Left_Opnd
=> Expr_From_SO_Ref
(Loc
, Old_NPMax
),
1614 Make_Integer_Literal
(Loc
,
1615 Intval
=> New_Fbit
/ SSU
)),
1618 New_Fbit
:= New_Fbit
mod SSU
;
1623 end Get_Next_Component_Location
;
1625 ----------------------
1626 -- Layout_Component --
1627 ----------------------
1629 procedure Layout_Component
(Comp
: Entity_Id
; Prev_Comp
: Entity_Id
) is
1630 Ctyp
: constant Entity_Id
:= Etype
(Comp
);
1631 ORC
: constant Entity_Id
:= Original_Record_Component
(Comp
);
1638 -- Increase alignment of record if necessary. Note that we do not
1639 -- do this for packed records, which have an alignment of one by
1640 -- default, or for records for which an explicit alignment was
1641 -- specified with an alignment clause.
1643 if not Is_Packed
(E
)
1644 and then not Has_Alignment_Clause
(E
)
1645 and then Alignment
(Ctyp
) > Alignment
(E
)
1647 Set_Alignment
(E
, Alignment
(Ctyp
));
1650 -- If original component set, then use same layout
1652 if Present
(ORC
) and then ORC
/= Comp
then
1653 Set_Normalized_Position
(Comp
, Normalized_Position
(ORC
));
1654 Set_Normalized_First_Bit
(Comp
, Normalized_First_Bit
(ORC
));
1655 Set_Normalized_Position_Max
(Comp
, Normalized_Position_Max
(ORC
));
1656 Set_Component_Bit_Offset
(Comp
, Component_Bit_Offset
(ORC
));
1657 Set_Esize
(Comp
, Esize
(ORC
));
1661 -- Parent field is always at start of record, this will overlap
1662 -- the actual fields that are part of the parent, and that's fine
1664 if Chars
(Comp
) = Name_uParent
then
1665 Set_Normalized_Position
(Comp
, Uint_0
);
1666 Set_Normalized_First_Bit
(Comp
, Uint_0
);
1667 Set_Normalized_Position_Max
(Comp
, Uint_0
);
1668 Set_Component_Bit_Offset
(Comp
, Uint_0
);
1669 Set_Esize
(Comp
, Esize
(Ctyp
));
1673 -- Check case of type of component has a scope of the record we are
1674 -- laying out. When this happens, the type in question is an Itype
1675 -- that has not yet been laid out (that's because such types do not
1676 -- get frozen in the normal manner, because there is no place for
1677 -- the freeze nodes).
1679 if Scope
(Ctyp
) = E
then
1683 -- If component already laid out, then we are done
1685 if Known_Normalized_Position
(Comp
) then
1689 -- Set size of component from type. We use the Esize except in a
1690 -- packed record, where we use the RM_Size (since that is what the
1691 -- RM_Size value, as distinct from the Object_Size is useful for!)
1693 if Is_Packed
(E
) then
1694 Set_Esize
(Comp
, RM_Size
(Ctyp
));
1696 Set_Esize
(Comp
, Esize
(Ctyp
));
1699 -- Compute the component position from the previous one. See if
1700 -- current component requires being on a storage unit boundary.
1702 -- If record is not packed, we always go to a storage unit boundary
1704 if not Is_Packed
(E
) then
1710 -- Elementary types do not need SU boundary in packed record
1712 if Is_Elementary_Type
(Ctyp
) then
1715 -- Packed array types with a modular packed array type do not
1716 -- force a storage unit boundary (since the code generation
1717 -- treats these as equivalent to the underlying modular type),
1719 elsif Is_Array_Type
(Ctyp
)
1720 and then Is_Bit_Packed_Array
(Ctyp
)
1721 and then Is_Modular_Integer_Type
(Packed_Array_Type
(Ctyp
))
1725 -- Record types with known length less than or equal to the length
1726 -- of long long integer can also be unaligned, since they can be
1727 -- treated as scalars.
1729 elsif Is_Record_Type
(Ctyp
)
1730 and then not Is_Dynamic_SO_Ref
(Esize
(Ctyp
))
1731 and then Esize
(Ctyp
) <= Esize
(Standard_Long_Long_Integer
)
1735 -- All other cases force a storage unit boundary, even when packed
1742 -- Now get the next component location
1744 Get_Next_Component_Location
1745 (Prev_Comp
, Alignment
(Ctyp
), Npos
, Fbit
, NPMax
, Forc
);
1746 Set_Normalized_Position
(Comp
, Npos
);
1747 Set_Normalized_First_Bit
(Comp
, Fbit
);
1748 Set_Normalized_Position_Max
(Comp
, NPMax
);
1750 -- Set Component_Bit_Offset in the static case
1752 if Known_Static_Normalized_Position
(Comp
)
1753 and then Known_Normalized_First_Bit
(Comp
)
1755 Set_Component_Bit_Offset
(Comp
, SSU
* Npos
+ Fbit
);
1757 end Layout_Component
;
1759 -----------------------
1760 -- Layout_Components --
1761 -----------------------
1763 procedure Layout_Components
1767 RM_Siz
: out SO_Ref
)
1774 -- Only lay out components if there are some to lay out!
1776 if Present
(From
) then
1778 -- Lay out components with no component clauses
1782 if Ekind
(Comp
) = E_Component
1783 or else Ekind
(Comp
) = E_Discriminant
1785 -- The compatibility of component clauses with composite
1786 -- types isn't checked in Sem_Ch13, so we check it here.
1788 if Present
(Component_Clause
(Comp
)) then
1789 if Is_Composite_Type
(Etype
(Comp
))
1790 and then Esize
(Comp
) < RM_Size
(Etype
(Comp
))
1792 Error_Msg_Uint_1
:= RM_Size
(Etype
(Comp
));
1794 ("size for & too small, minimum allowed is ^",
1795 Component_Clause
(Comp
),
1800 Layout_Component
(Comp
, Prev_Comp
);
1805 exit when Comp
= To
;
1810 -- Set size fields, both are zero if no components
1812 if No
(Prev_Comp
) then
1816 -- If record subtype with non-static discriminants, then we don't
1817 -- know which variant will be the one which gets chosen. We don't
1818 -- just want to set the maximum size from the base, because the
1819 -- size should depend on the particular variant.
1821 -- What we do is to use the RM_Size of the base type, which has
1822 -- the necessary conditional computation of the size, using the
1823 -- size information for the particular variant chosen. Records
1824 -- with default discriminants for example have an Esize that is
1825 -- set to the maximum of all variants, but that's not what we
1826 -- want for a constrained subtype.
1828 elsif Ekind
(E
) = E_Record_Subtype
1829 and then not Has_Static_Discriminants
(E
)
1832 BT
: constant Node_Id
:= Base_Type
(E
);
1834 Esiz
:= RM_Size
(BT
);
1835 RM_Siz
:= RM_Size
(BT
);
1836 Set_Alignment
(E
, Alignment
(BT
));
1840 -- First the object size, for which we align past the last field
1841 -- to the alignment of the record (the object size is required to
1842 -- be a multiple of the alignment).
1844 Get_Next_Component_Location
1852 -- If the resulting normalized position is a dynamic reference,
1853 -- then the size is dynamic, and is stored in storage units. In
1854 -- this case, we set the RM_Size to the same value, it is simply
1855 -- not worth distinguishing Esize and RM_Size values in the
1856 -- dynamic case, since the RM has nothing to say about them.
1858 -- Note that a size cannot have been given in this case, since
1859 -- size specifications cannot be given for variable length types.
1862 Align
: constant Uint
:= Alignment
(E
);
1865 if Is_Dynamic_SO_Ref
(End_Npos
) then
1868 -- Set the Object_Size allowing for the alignment. In the
1869 -- dynamic case, we must do the actual runtime computation.
1870 -- We can skip this in the non-packed record case if the
1871 -- last component has a smaller alignment than the overall
1872 -- record alignment.
1874 if Is_Dynamic_SO_Ref
(End_NPMax
) then
1878 or else Alignment
(Etype
(Prev_Comp
)) < Align
1880 -- The expression we build is:
1881 -- (expr + align - 1) / align * align
1886 Make_Op_Multiply
(Loc
,
1888 Make_Op_Divide
(Loc
,
1892 Expr_From_SO_Ref
(Loc
, Esiz
),
1894 Make_Integer_Literal
(Loc
,
1895 Intval
=> Align
- 1)),
1897 Make_Integer_Literal
(Loc
, Align
)),
1899 Make_Integer_Literal
(Loc
, Align
)),
1904 -- Here Esiz is static, so we can adjust the alignment
1905 -- directly go give the required aligned value.
1908 Esiz
:= (End_NPMax
+ Align
- 1) / Align
* Align
* SSU
;
1911 -- Case where computed size is static
1914 -- The ending size was computed in Npos in storage units,
1915 -- but the actual size is stored in bits, so adjust
1916 -- accordingly. We also adjust the size to match the
1919 Esiz
:= (End_NPMax
+ Align
- 1) / Align
* Align
* SSU
;
1921 -- Compute the resulting Value_Size (RM_Size). For this
1922 -- purpose we do not force alignment of the record or
1923 -- storage size alignment of the result.
1925 Get_Next_Component_Location
1933 RM_Siz
:= End_Npos
* SSU
+ End_Fbit
;
1934 Set_And_Check_Static_Size
(E
, Esiz
, RM_Siz
);
1938 end Layout_Components
;
1940 -------------------------------
1941 -- Layout_Non_Variant_Record --
1942 -------------------------------
1944 procedure Layout_Non_Variant_Record
is
1948 Layout_Components
(First_Entity
(E
), Last_Entity
(E
), Esiz
, RM_Siz
);
1949 Set_Esize
(E
, Esiz
);
1950 Set_RM_Size
(E
, RM_Siz
);
1951 end Layout_Non_Variant_Record
;
1953 ---------------------------
1954 -- Layout_Variant_Record --
1955 ---------------------------
1957 procedure Layout_Variant_Record
is
1958 Tdef
: constant Node_Id
:= Type_Definition
(Decl
);
1959 First_Discr
: Entity_Id
;
1960 Last_Discr
: Entity_Id
;
1964 pragma Warnings
(Off
, SO_Ref
);
1966 RM_Siz_Expr
: Node_Id
:= Empty
;
1967 -- Expression for the evolving RM_Siz value. This is typically a
1968 -- conditional expression which involves tests of discriminant values
1969 -- that are formed as references to the entity V. At the end of
1970 -- scanning all the components, a suitable function is constructed
1971 -- in which V is the parameter.
1973 -----------------------
1974 -- Local Subprograms --
1975 -----------------------
1977 procedure Layout_Component_List
1980 RM_Siz_Expr
: out Node_Id
);
1981 -- Recursive procedure, called to lay out one component list Esiz
1982 -- and RM_Siz_Expr are set to the Object_Size and Value_Size values
1983 -- respectively representing the record size up to and including the
1984 -- last component in the component list (including any variants in
1985 -- this component list). RM_Siz_Expr is returned as an expression
1986 -- which may in the general case involve some references to the
1987 -- discriminants of the current record value, referenced by selecting
1988 -- from the entity V.
1990 ---------------------------
1991 -- Layout_Component_List --
1992 ---------------------------
1994 procedure Layout_Component_List
1997 RM_Siz_Expr
: out Node_Id
)
1999 Citems
: constant List_Id
:= Component_Items
(Clist
);
2000 Vpart
: constant Node_Id
:= Variant_Part
(Clist
);
2004 RMS_Ent
: Entity_Id
;
2007 if Is_Non_Empty_List
(Citems
) then
2009 (From
=> Defining_Identifier
(First
(Citems
)),
2010 To
=> Defining_Identifier
(Last
(Citems
)),
2014 Layout_Components
(Empty
, Empty
, Esiz
, RM_Siz
);
2017 -- Case where no variants are present in the component list
2021 -- The Esiz value has been correctly set by the call to
2022 -- Layout_Components, so there is nothing more to be done.
2024 -- For RM_Siz, we have an SO_Ref value, which we must convert
2025 -- to an appropriate expression.
2027 if Is_Static_SO_Ref
(RM_Siz
) then
2029 Make_Integer_Literal
(Loc
,
2033 RMS_Ent
:= Get_Dynamic_SO_Entity
(RM_Siz
);
2035 -- If the size is represented by a function, then we create
2036 -- an appropriate function call using V as the parameter to
2039 if Is_Discrim_SO_Function
(RMS_Ent
) then
2041 Make_Function_Call
(Loc
,
2042 Name
=> New_Occurrence_Of
(RMS_Ent
, Loc
),
2043 Parameter_Associations
=> New_List
(
2044 Make_Identifier
(Loc
, Vname
)));
2046 -- If the size is represented by a constant, then the
2047 -- expression we want is a reference to this constant
2050 RM_Siz_Expr
:= New_Occurrence_Of
(RMS_Ent
, Loc
);
2054 -- Case where variants are present in this component list
2064 D_Entity
: Entity_Id
;
2067 RM_Siz_Expr
:= Empty
;
2070 Var
:= Last
(Variants
(Vpart
));
2071 while Present
(Var
) loop
2073 Layout_Component_List
2074 (Component_List
(Var
), EsizV
, RM_SizV
);
2076 -- Set the Object_Size. If this is the first variant,
2077 -- we just set the size of this first variant.
2079 if Var
= Last
(Variants
(Vpart
)) then
2082 -- Otherwise the Object_Size is formed as a maximum
2083 -- of Esiz so far from previous variants, and the new
2084 -- Esiz value from the variant we just processed.
2086 -- If both values are static, we can just compute the
2087 -- maximum directly to save building junk nodes.
2089 elsif not Is_Dynamic_SO_Ref
(Esiz
)
2090 and then not Is_Dynamic_SO_Ref
(EsizV
)
2092 Esiz
:= UI_Max
(Esiz
, EsizV
);
2094 -- If either value is dynamic, then we have to generate
2095 -- an appropriate Standard_Unsigned'Max attribute call.
2096 -- If one of the values is static then it needs to be
2097 -- converted from bits to storage units to be compatible
2098 -- with the dynamic value.
2101 if Is_Static_SO_Ref
(Esiz
) then
2102 Esiz
:= (Esiz
+ SSU
- 1) / SSU
;
2105 if Is_Static_SO_Ref
(EsizV
) then
2106 EsizV
:= (EsizV
+ SSU
- 1) / SSU
;
2111 (Make_Attribute_Reference
(Loc
,
2112 Attribute_Name
=> Name_Max
,
2114 New_Occurrence_Of
(Standard_Unsigned
, Loc
),
2115 Expressions
=> New_List
(
2116 Expr_From_SO_Ref
(Loc
, Esiz
),
2117 Expr_From_SO_Ref
(Loc
, EsizV
))),
2122 -- Now deal with Value_Size (RM_Siz). We are aiming at
2123 -- an expression that looks like:
2125 -- if xxDx (V.disc) then rmsiz1
2126 -- else if xxDx (V.disc) then rmsiz2
2129 -- Where rmsiz1, rmsiz2... are the RM_Siz values for the
2130 -- individual variants, and xxDx are the discriminant
2131 -- checking functions generated for the variant type.
2133 -- If this is the first variant, we simply set the result
2134 -- as the expression. Note that this takes care of the
2137 if No
(RM_Siz_Expr
) then
2139 -- If this is the only variant and the size is a
2140 -- literal, then use bit size as is, otherwise convert
2141 -- to storage units and continue to the next variant.
2144 and then Nkind
(RM_SizV
) = N_Integer_Literal
2146 RM_Siz_Expr
:= RM_SizV
;
2148 RM_Siz_Expr
:= Bits_To_SU
(RM_SizV
);
2151 -- Otherwise construct the appropriate test
2154 -- The test to be used in general is a call to the
2155 -- discriminant checking function. However, it is
2156 -- definitely worth special casing the very common
2157 -- case where a single value is involved.
2159 Dchoice
:= First
(Discrete_Choices
(Var
));
2161 if No
(Next
(Dchoice
))
2162 and then Nkind
(Dchoice
) /= N_Range
2164 -- Discriminant to be tested
2167 Make_Selected_Component
(Loc
,
2169 Make_Identifier
(Loc
, Vname
),
2172 (Entity
(Name
(Vpart
)), Loc
));
2176 Left_Opnd
=> Discrim
,
2177 Right_Opnd
=> New_Copy
(Dchoice
));
2179 -- Generate a call to the discriminant-checking
2180 -- function for the variant. Note that the result
2181 -- has to be complemented since the function returns
2182 -- False when the passed discriminant value matches.
2185 -- The checking function takes all of the type's
2186 -- discriminants as parameters, so a list of all
2187 -- the selected discriminants must be constructed.
2190 D_Entity
:= First_Discriminant
(E
);
2191 while Present
(D_Entity
) loop
2193 Make_Selected_Component
(Loc
,
2195 Make_Identifier
(Loc
, Vname
),
2197 New_Occurrence_Of
(D_Entity
, Loc
)),
2200 D_Entity
:= Next_Discriminant
(D_Entity
);
2206 Make_Function_Call
(Loc
,
2209 (Dcheck_Function
(Var
), Loc
),
2210 Parameter_Associations
=>
2215 Make_Conditional_Expression
(Loc
,
2218 (Dtest
, Bits_To_SU
(RM_SizV
), RM_Siz_Expr
));
2225 end Layout_Component_List
;
2227 -- Start of processing for Layout_Variant_Record
2230 -- We need the discriminant checking functions, since we generate
2231 -- calls to these functions for the RM_Size expression, so make
2232 -- sure that these functions have been constructed in time.
2234 Build_Discr_Checking_Funcs
(Decl
);
2236 -- Lay out the discriminants
2238 First_Discr
:= First_Discriminant
(E
);
2239 Last_Discr
:= First_Discr
;
2240 while Present
(Next_Discriminant
(Last_Discr
)) loop
2241 Next_Discriminant
(Last_Discr
);
2245 (From
=> First_Discr
,
2250 -- Lay out the main component list (this will make recursive calls
2251 -- to lay out all component lists nested within variants).
2253 Layout_Component_List
(Component_List
(Tdef
), Esiz
, RM_Siz_Expr
);
2254 Set_Esize
(E
, Esiz
);
2256 -- If the RM_Size is a literal, set its value
2258 if Nkind
(RM_Siz_Expr
) = N_Integer_Literal
then
2259 Set_RM_Size
(E
, Intval
(RM_Siz_Expr
));
2261 -- Otherwise we construct a dynamic SO_Ref
2270 end Layout_Variant_Record
;
2272 -- Start of processing for Layout_Record_Type
2275 -- If this is a cloned subtype, just copy the size fields from the
2276 -- original, nothing else needs to be done in this case, since the
2277 -- components themselves are all shared.
2279 if (Ekind
(E
) = E_Record_Subtype
2281 Ekind
(E
) = E_Class_Wide_Subtype
)
2282 and then Present
(Cloned_Subtype
(E
))
2284 Set_Esize
(E
, Esize
(Cloned_Subtype
(E
)));
2285 Set_RM_Size
(E
, RM_Size
(Cloned_Subtype
(E
)));
2286 Set_Alignment
(E
, Alignment
(Cloned_Subtype
(E
)));
2288 -- Another special case, class-wide types. The RM says that the size
2289 -- of such types is implementation defined (RM 13.3(48)). What we do
2290 -- here is to leave the fields set as unknown values, and the backend
2291 -- determines the actual behavior.
2293 elsif Ekind
(E
) = E_Class_Wide_Type
then
2299 -- Initialize alignment conservatively to 1. This value will be
2300 -- increased as necessary during processing of the record.
2302 if Unknown_Alignment
(E
) then
2303 Set_Alignment
(E
, Uint_1
);
2306 -- Initialize previous component. This is Empty unless there are
2307 -- components which have already been laid out by component clauses.
2308 -- If there are such components, we start our lay out of the
2309 -- remaining components following the last such component.
2313 Comp
:= First_Component_Or_Discriminant
(E
);
2314 while Present
(Comp
) loop
2315 if Present
(Component_Clause
(Comp
)) then
2318 Component_Bit_Offset
(Comp
) >
2319 Component_Bit_Offset
(Prev_Comp
)
2325 Next_Component_Or_Discriminant
(Comp
);
2328 -- We have two separate circuits, one for non-variant records and
2329 -- one for variant records. For non-variant records, we simply go
2330 -- through the list of components. This handles all the non-variant
2331 -- cases including those cases of subtypes where there is no full
2332 -- type declaration, so the tree cannot be used to drive the layout.
2333 -- For variant records, we have to drive the layout from the tree
2334 -- since we need to understand the variant structure in this case.
2336 if Present
(Full_View
(E
)) then
2337 Decl
:= Declaration_Node
(Full_View
(E
));
2339 Decl
:= Declaration_Node
(E
);
2342 -- Scan all the components
2344 if Nkind
(Decl
) = N_Full_Type_Declaration
2345 and then Has_Discriminants
(E
)
2346 and then Nkind
(Type_Definition
(Decl
)) = N_Record_Definition
2347 and then Present
(Component_List
(Type_Definition
(Decl
)))
2349 Present
(Variant_Part
(Component_List
(Type_Definition
(Decl
))))
2351 Layout_Variant_Record
;
2353 Layout_Non_Variant_Record
;
2356 end Layout_Record_Type
;
2362 procedure Layout_Type
(E
: Entity_Id
) is
2363 Desig_Type
: Entity_Id
;
2366 -- For string literal types, for now, kill the size always, this is
2367 -- because gigi does not like or need the size to be set ???
2369 if Ekind
(E
) = E_String_Literal_Subtype
then
2370 Set_Esize
(E
, Uint_0
);
2371 Set_RM_Size
(E
, Uint_0
);
2375 -- For access types, set size/alignment. This is system address size,
2376 -- except for fat pointers (unconstrained array access types), where the
2377 -- size is two times the address size, to accommodate the two pointers
2378 -- that are required for a fat pointer (data and template). Note that
2379 -- E_Access_Protected_Subprogram_Type is not an access type for this
2380 -- purpose since it is not a pointer but is equivalent to a record. For
2381 -- access subtypes, copy the size from the base type since Gigi
2382 -- represents them the same way.
2384 if Is_Access_Type
(E
) then
2386 Desig_Type
:= Underlying_Type
(Designated_Type
(E
));
2388 -- If we only have a limited view of the type, see whether the
2389 -- non-limited view is available.
2391 if From_With_Type
(Designated_Type
(E
))
2392 and then Ekind
(Designated_Type
(E
)) = E_Incomplete_Type
2393 and then Present
(Non_Limited_View
(Designated_Type
(E
)))
2395 Desig_Type
:= Non_Limited_View
(Designated_Type
(E
));
2398 -- If Esize already set (e.g. by a size clause), then nothing further
2401 if Known_Esize
(E
) then
2404 -- Access to subprogram is a strange beast, and we let the backend
2405 -- figure out what is needed (it may be some kind of fat pointer,
2406 -- including the static link for example.
2408 elsif Is_Access_Protected_Subprogram_Type
(E
) then
2411 -- For access subtypes, copy the size information from base type
2413 elsif Ekind
(E
) = E_Access_Subtype
then
2414 Set_Size_Info
(E
, Base_Type
(E
));
2415 Set_RM_Size
(E
, RM_Size
(Base_Type
(E
)));
2417 -- For other access types, we use either address size, or, if a fat
2418 -- pointer is used (pointer-to-unconstrained array case), twice the
2419 -- address size to accommodate a fat pointer.
2421 elsif Present
(Desig_Type
)
2422 and then Is_Array_Type
(Desig_Type
)
2423 and then not Is_Constrained
(Desig_Type
)
2424 and then not Has_Completion_In_Body
(Desig_Type
)
2425 and then not Debug_Flag_6
2427 Init_Size
(E
, 2 * System_Address_Size
);
2429 -- Check for bad convention set
2431 if Warn_On_Export_Import
2433 (Convention
(E
) = Convention_C
2435 Convention
(E
) = Convention_CPP
)
2438 ("?this access type does not correspond to C pointer", E
);
2441 -- If the designated type is a limited view it is unanalyzed. We can
2442 -- examine the declaration itself to determine whether it will need a
2445 elsif Present
(Desig_Type
)
2446 and then Present
(Parent
(Desig_Type
))
2447 and then Nkind
(Parent
(Desig_Type
)) = N_Full_Type_Declaration
2449 Nkind
(Type_Definition
(Parent
(Desig_Type
)))
2450 = N_Unconstrained_Array_Definition
2452 Init_Size
(E
, 2 * System_Address_Size
);
2454 -- When the target is AAMP, access-to-subprogram types are fat
2455 -- pointers consisting of the subprogram address and a static link,
2456 -- with the exception of library-level access types (including
2457 -- library-level anonymous access types, such as for components),
2458 -- where a simple subprogram address is used.
2460 elsif AAMP_On_Target
2462 ((Ekind
(E
) = E_Access_Subprogram_Type
2463 and then Present
(Enclosing_Subprogram
(E
)))
2465 (Ekind
(E
) = E_Anonymous_Access_Subprogram_Type
2467 (not Is_Local_Anonymous_Access
(E
)
2468 or else Present
(Enclosing_Subprogram
(E
)))))
2470 Init_Size
(E
, 2 * System_Address_Size
);
2472 Init_Size
(E
, System_Address_Size
);
2475 -- On VMS, reset size to 32 for convention C access type if no
2476 -- explicit size clause is given and the default size is 64. Really
2477 -- we do not know the size, since depending on options for the VMS
2478 -- compiler, the size of a pointer type can be 32 or 64, but choosing
2479 -- 32 as the default improves compatibility with legacy VMS code.
2481 -- Note: we do not use Has_Size_Clause in the test below, because we
2482 -- want to catch the case of a derived type inheriting a size clause.
2483 -- We want to consider this to be an explicit size clause for this
2484 -- purpose, since it would be weird not to inherit the size in this
2487 -- We do NOT do this if we are in -gnatdm mode on a non-VMS target
2488 -- since in that case we want the normal pointer representation.
2490 if Opt
.True_VMS_Target
2491 and then (Convention
(E
) = Convention_C
2493 Convention
(E
) = Convention_CPP
)
2494 and then No
(Get_Attribute_Definition_Clause
(E
, Attribute_Size
))
2495 and then Esize
(E
) = 64
2500 Set_Elem_Alignment
(E
);
2502 -- Scalar types: set size and alignment
2504 elsif Is_Scalar_Type
(E
) then
2506 -- For discrete types, the RM_Size and Esize must be set already,
2507 -- since this is part of the earlier processing and the front end is
2508 -- always required to lay out the sizes of such types (since they are
2509 -- available as static attributes). All we do is to check that this
2510 -- rule is indeed obeyed!
2512 if Is_Discrete_Type
(E
) then
2514 -- If the RM_Size is not set, then here is where we set it
2516 -- Note: an RM_Size of zero looks like not set here, but this
2517 -- is a rare case, and we can simply reset it without any harm.
2519 if not Known_RM_Size
(E
) then
2520 Set_Discrete_RM_Size
(E
);
2523 -- If Esize for a discrete type is not set then set it
2525 if not Known_Esize
(E
) then
2531 -- If size is big enough, set it and exit
2533 if S
>= RM_Size
(E
) then
2537 -- If the RM_Size is greater than 64 (happens only when
2538 -- strange values are specified by the user, then Esize
2539 -- is simply a copy of RM_Size, it will be further
2540 -- refined later on)
2543 Set_Esize
(E
, RM_Size
(E
));
2546 -- Otherwise double possible size and keep trying
2555 -- For non-discrete scalar types, if the RM_Size is not set, then set
2556 -- it now to a copy of the Esize if the Esize is set.
2559 if Known_Esize
(E
) and then Unknown_RM_Size
(E
) then
2560 Set_RM_Size
(E
, Esize
(E
));
2564 Set_Elem_Alignment
(E
);
2566 -- Non-elementary (composite) types
2569 -- For packed arrays, take size and alignment values from the packed
2570 -- array type if a packed array type has been created and the fields
2571 -- are not currently set.
2573 if Is_Array_Type
(E
) and then Present
(Packed_Array_Type
(E
)) then
2575 PAT
: constant Entity_Id
:= Packed_Array_Type
(E
);
2578 if Unknown_Esize
(E
) then
2579 Set_Esize
(E
, Esize
(PAT
));
2582 if Unknown_RM_Size
(E
) then
2583 Set_RM_Size
(E
, RM_Size
(PAT
));
2586 if Unknown_Alignment
(E
) then
2587 Set_Alignment
(E
, Alignment
(PAT
));
2592 -- If Esize is set, and RM_Size is not, RM_Size is copied from Esize.
2593 -- At least for now this seems reasonable, and is in any case needed
2594 -- for compatibility with old versions of gigi.
2596 if Known_Esize
(E
) and then Unknown_RM_Size
(E
) then
2597 Set_RM_Size
(E
, Esize
(E
));
2600 -- For array base types, set component size if object size of the
2601 -- component type is known and is a small power of 2 (8, 16, 32, 64),
2602 -- since this is what will always be used.
2604 if Ekind
(E
) = E_Array_Type
2605 and then Unknown_Component_Size
(E
)
2608 CT
: constant Entity_Id
:= Component_Type
(E
);
2611 -- For some reasons, access types can cause trouble, So let's
2612 -- just do this for scalar types ???
2615 and then Is_Scalar_Type
(CT
)
2616 and then Known_Static_Esize
(CT
)
2619 S
: constant Uint
:= Esize
(CT
);
2621 if Addressable
(S
) then
2622 Set_Component_Size
(E
, S
);
2630 -- Lay out array and record types if front end layout set
2632 if Frontend_Layout_On_Target
then
2633 if Is_Array_Type
(E
) and then not Is_Bit_Packed_Array
(E
) then
2634 Layout_Array_Type
(E
);
2635 elsif Is_Record_Type
(E
) then
2636 Layout_Record_Type
(E
);
2639 -- Case of backend layout, we still do a little in the front end
2642 -- Processing for record types
2644 if Is_Record_Type
(E
) then
2646 -- Special remaining processing for record types with a known
2647 -- size of 16, 32, or 64 bits whose alignment is not yet set.
2648 -- For these types, we set a corresponding alignment matching
2649 -- the size if possible, or as large as possible if not.
2651 if Convention
(E
) = Convention_Ada
2652 and then not Debug_Flag_Q
2654 Set_Composite_Alignment
(E
);
2657 -- Processing for array types
2659 elsif Is_Array_Type
(E
) then
2661 -- For arrays that are required to be atomic, we do the same
2662 -- processing as described above for short records, since we
2663 -- really need to have the alignment set for the whole array.
2665 if Is_Atomic
(E
) and then not Debug_Flag_Q
then
2666 Set_Composite_Alignment
(E
);
2669 -- For unpacked array types, set an alignment of 1 if we know
2670 -- that the component alignment is not greater than 1. The reason
2671 -- we do this is to avoid unnecessary copying of slices of such
2672 -- arrays when passed to subprogram parameters (see special test
2673 -- in Exp_Ch6.Expand_Actuals).
2675 if not Is_Packed
(E
)
2676 and then Unknown_Alignment
(E
)
2678 if Known_Static_Component_Size
(E
)
2679 and then Component_Size
(E
) = 1
2681 Set_Alignment
(E
, Uint_1
);
2685 -- We need to know whether the size depends on the value of one
2686 -- or more discriminants to select the return mechanism. Skip if
2687 -- errors are present, to prevent cascaded messages.
2689 if Serious_Errors_Detected
= 0 then
2690 Compute_Size_Depends_On_Discriminant
(E
);
2696 -- Final step is to check that Esize and RM_Size are compatible
2698 if Known_Static_Esize
(E
) and then Known_Static_RM_Size
(E
) then
2699 if Esize
(E
) < RM_Size
(E
) then
2701 -- Esize is less than RM_Size. That's not good. First we test
2702 -- whether this was set deliberately with an Object_Size clause
2703 -- and if so, object to the clause.
2705 if Has_Object_Size_Clause
(E
) then
2706 Error_Msg_Uint_1
:= RM_Size
(E
);
2708 ("object size is too small, minimum allowed is ^",
2709 Expression
(Get_Attribute_Definition_Clause
2710 (E
, Attribute_Object_Size
)));
2713 -- Adjust Esize up to RM_Size value
2716 Size
: constant Uint
:= RM_Size
(E
);
2719 Set_Esize
(E
, RM_Size
(E
));
2721 -- For scalar types, increase Object_Size to power of 2, but
2722 -- not less than a storage unit in any case (i.e., normally
2723 -- this means it will be storage-unit addressable).
2725 if Is_Scalar_Type
(E
) then
2726 if Size
<= System_Storage_Unit
then
2727 Init_Esize
(E
, System_Storage_Unit
);
2728 elsif Size
<= 16 then
2730 elsif Size
<= 32 then
2733 Set_Esize
(E
, (Size
+ 63) / 64 * 64);
2736 -- Finally, make sure that alignment is consistent with
2737 -- the newly assigned size.
2739 while Alignment
(E
) * System_Storage_Unit
< Esize
(E
)
2740 and then Alignment
(E
) < Maximum_Alignment
2742 Set_Alignment
(E
, 2 * Alignment
(E
));
2750 ---------------------
2751 -- Rewrite_Integer --
2752 ---------------------
2754 procedure Rewrite_Integer
(N
: Node_Id
; V
: Uint
) is
2755 Loc
: constant Source_Ptr
:= Sloc
(N
);
2756 Typ
: constant Entity_Id
:= Etype
(N
);
2758 Rewrite
(N
, Make_Integer_Literal
(Loc
, Intval
=> V
));
2760 end Rewrite_Integer
;
2762 -------------------------------
2763 -- Set_And_Check_Static_Size --
2764 -------------------------------
2766 procedure Set_And_Check_Static_Size
2773 procedure Check_Size_Too_Small
(Spec
: Uint
; Min
: Uint
);
2774 -- Spec is the number of bit specified in the size clause, and Min is
2775 -- the minimum computed size. An error is given that the specified size
2776 -- is too small if Spec < Min, and in this case both Esize and RM_Size
2777 -- are set to unknown in E. The error message is posted on node SC.
2779 procedure Check_Unused_Bits
(Spec
: Uint
; Max
: Uint
);
2780 -- Spec is the number of bits specified in the size clause, and Max is
2781 -- the maximum computed size. A warning is given about unused bits if
2782 -- Spec > Max. This warning is posted on node SC.
2784 --------------------------
2785 -- Check_Size_Too_Small --
2786 --------------------------
2788 procedure Check_Size_Too_Small
(Spec
: Uint
; Min
: Uint
) is
2791 Error_Msg_Uint_1
:= Min
;
2792 Error_Msg_NE
("size for & too small, minimum allowed is ^", SC
, E
);
2796 end Check_Size_Too_Small
;
2798 -----------------------
2799 -- Check_Unused_Bits --
2800 -----------------------
2802 procedure Check_Unused_Bits
(Spec
: Uint
; Max
: Uint
) is
2805 Error_Msg_Uint_1
:= Spec
- Max
;
2806 Error_Msg_NE
("?^ bits of & unused", SC
, E
);
2808 end Check_Unused_Bits
;
2810 -- Start of processing for Set_And_Check_Static_Size
2813 -- Case where Object_Size (Esize) is already set by a size clause
2815 if Known_Static_Esize
(E
) then
2816 SC
:= Size_Clause
(E
);
2819 SC
:= Get_Attribute_Definition_Clause
(E
, Attribute_Object_Size
);
2822 -- Perform checks on specified size against computed sizes
2824 if Present
(SC
) then
2825 Check_Unused_Bits
(Esize
(E
), Esiz
);
2826 Check_Size_Too_Small
(Esize
(E
), RM_Siz
);
2830 -- Case where Value_Size (RM_Size) is set by specific Value_Size clause
2831 -- (we do not need to worry about Value_Size being set by a Size clause,
2832 -- since that will have set Esize as well, and we already took care of
2835 if Known_Static_RM_Size
(E
) then
2836 SC
:= Get_Attribute_Definition_Clause
(E
, Attribute_Value_Size
);
2838 -- Perform checks on specified size against computed sizes
2840 if Present
(SC
) then
2841 Check_Unused_Bits
(RM_Size
(E
), Esiz
);
2842 Check_Size_Too_Small
(RM_Size
(E
), RM_Siz
);
2846 -- Set sizes if unknown
2848 if Unknown_Esize
(E
) then
2849 Set_Esize
(E
, Esiz
);
2852 if Unknown_RM_Size
(E
) then
2853 Set_RM_Size
(E
, RM_Siz
);
2855 end Set_And_Check_Static_Size
;
2857 -----------------------------
2858 -- Set_Composite_Alignment --
2859 -----------------------------
2861 procedure Set_Composite_Alignment
(E
: Entity_Id
) is
2866 -- If alignment is already set, then nothing to do
2868 if Known_Alignment
(E
) then
2872 -- Alignment is not known, see if we can set it, taking into account
2873 -- the setting of the Optimize_Alignment mode.
2875 -- If Optimize_Alignment is set to Space, then packed records always
2876 -- have an alignment of 1. But don't do anything for atomic records
2877 -- since we may need higher alignment for indivisible access.
2879 if Optimize_Alignment_Space
(E
)
2880 and then Is_Record_Type
(E
)
2881 and then Is_Packed
(E
)
2882 and then not Is_Atomic
(E
)
2886 -- Not a record, or not packed
2889 -- The only other cases we worry about here are where the size is
2890 -- statically known at compile time.
2892 if Known_Static_Esize
(E
) then
2895 elsif Unknown_Esize
(E
)
2896 and then Known_Static_RM_Size
(E
)
2904 -- Size is known, alignment is not set
2906 -- Reset alignment to match size if the known size is exactly 2, 4,
2907 -- or 8 storage units.
2909 if Siz
= 2 * System_Storage_Unit
then
2911 elsif Siz
= 4 * System_Storage_Unit
then
2913 elsif Siz
= 8 * System_Storage_Unit
then
2916 -- If Optimize_Alignment is set to Space, then make sure the
2917 -- alignment matches the size, for example, if the size is 17
2918 -- bytes then we want an alignment of 1 for the type.
2920 elsif Optimize_Alignment_Space
(E
) then
2921 if Siz
mod (8 * System_Storage_Unit
) = 0 then
2923 elsif Siz
mod (4 * System_Storage_Unit
) = 0 then
2925 elsif Siz
mod (2 * System_Storage_Unit
) = 0 then
2931 -- If Optimize_Alignment is set to Time, then we reset for odd
2932 -- "in between sizes", for example a 17 bit record is given an
2933 -- alignment of 4. Note that this matches the old VMS behavior
2934 -- in versions of GNAT prior to 6.1.1.
2936 elsif Optimize_Alignment_Time
(E
)
2937 and then Siz
> System_Storage_Unit
2938 and then Siz
<= 8 * System_Storage_Unit
2940 if Siz
<= 2 * System_Storage_Unit
then
2942 elsif Siz
<= 4 * System_Storage_Unit
then
2944 else -- Siz <= 8 * System_Storage_Unit then
2948 -- No special alignment fiddling needed
2955 -- Here we have Set Align to the proposed improved value. Make sure the
2956 -- value set does not exceed Maximum_Alignment for the target.
2958 if Align
> Maximum_Alignment
then
2959 Align
:= Maximum_Alignment
;
2962 -- Further processing for record types only to reduce the alignment
2963 -- set by the above processing in some specific cases. We do not
2964 -- do this for atomic records, since we need max alignment there,
2966 if Is_Record_Type
(E
) and then not Is_Atomic
(E
) then
2968 -- For records, there is generally no point in setting alignment
2969 -- higher than word size since we cannot do better than move by
2970 -- words in any case. Omit this if we are optimizing for time,
2971 -- since conceivably we may be able to do better.
2973 if Align
> System_Word_Size
/ System_Storage_Unit
2974 and then not Optimize_Alignment_Time
(E
)
2976 Align
:= System_Word_Size
/ System_Storage_Unit
;
2979 -- Check components. If any component requires a higher alignment,
2980 -- then we set that higher alignment in any case. Don't do this if
2981 -- we have Optimize_Alignment set to Space. Note that that covers
2982 -- the case of packed records, where we already set alignment to 1.
2984 if not Optimize_Alignment_Space
(E
) then
2989 Comp
:= First_Component
(E
);
2990 while Present
(Comp
) loop
2991 if Known_Alignment
(Etype
(Comp
)) then
2993 Calign
: constant Uint
:= Alignment
(Etype
(Comp
));
2996 -- The cases to process are when the alignment of the
2997 -- component type is larger than the alignment we have
2998 -- so far, and either there is no component clause for
2999 -- the component, or the length set by the component
3000 -- clause matches the length of the component type.
3004 (Unknown_Esize
(Comp
)
3005 or else (Known_Static_Esize
(Comp
)
3008 Calign
* System_Storage_Unit
))
3010 Align
:= UI_To_Int
(Calign
);
3015 Next_Component
(Comp
);
3021 -- Set chosen alignment, and increase Esize if necessary to match the
3022 -- chosen alignment.
3024 Set_Alignment
(E
, UI_From_Int
(Align
));
3026 if Known_Static_Esize
(E
)
3027 and then Esize
(E
) < Align
* System_Storage_Unit
3029 Set_Esize
(E
, UI_From_Int
(Align
* System_Storage_Unit
));
3031 end Set_Composite_Alignment
;
3033 --------------------------
3034 -- Set_Discrete_RM_Size --
3035 --------------------------
3037 procedure Set_Discrete_RM_Size
(Def_Id
: Entity_Id
) is
3038 FST
: constant Entity_Id
:= First_Subtype
(Def_Id
);
3041 -- All discrete types except for the base types in standard are
3042 -- constrained, so indicate this by setting Is_Constrained.
3044 Set_Is_Constrained
(Def_Id
);
3046 -- Set generic types to have an unknown size, since the representation
3047 -- of a generic type is irrelevant, in view of the fact that they have
3048 -- nothing to do with code.
3050 if Is_Generic_Type
(Root_Type
(FST
)) then
3051 Set_RM_Size
(Def_Id
, Uint_0
);
3053 -- If the subtype statically matches the first subtype, then it is
3054 -- required to have exactly the same layout. This is required by
3055 -- aliasing considerations.
3057 elsif Def_Id
/= FST
and then
3058 Subtypes_Statically_Match
(Def_Id
, FST
)
3060 Set_RM_Size
(Def_Id
, RM_Size
(FST
));
3061 Set_Size_Info
(Def_Id
, FST
);
3063 -- In all other cases the RM_Size is set to the minimum size. Note that
3064 -- this routine is never called for subtypes for which the RM_Size is
3065 -- set explicitly by an attribute clause.
3068 Set_RM_Size
(Def_Id
, UI_From_Int
(Minimum_Size
(Def_Id
)));
3070 end Set_Discrete_RM_Size
;
3072 ------------------------
3073 -- Set_Elem_Alignment --
3074 ------------------------
3076 procedure Set_Elem_Alignment
(E
: Entity_Id
) is
3078 -- Do not set alignment for packed array types, unless we are doing
3079 -- front end layout, because otherwise this is always handled in the
3082 if Is_Packed_Array_Type
(E
) and then not Frontend_Layout_On_Target
then
3085 -- If there is an alignment clause, then we respect it
3087 elsif Has_Alignment_Clause
(E
) then
3090 -- If the size is not set, then don't attempt to set the alignment. This
3091 -- happens in the backend layout case for access-to-subprogram types.
3093 elsif not Known_Static_Esize
(E
) then
3096 -- For access types, do not set the alignment if the size is less than
3097 -- the allowed minimum size. This avoids cascaded error messages.
3099 elsif Is_Access_Type
(E
)
3100 and then Esize
(E
) < System_Address_Size
3105 -- Here we calculate the alignment as the largest power of two multiple
3106 -- of System.Storage_Unit that does not exceed either the object size of
3107 -- the type, or the maximum allowed alignment.
3113 Max_Alignment
: Nat
;
3116 -- The given Esize may be larger that int'last because of a previous
3117 -- error, and the call to UI_To_Int will fail, so use default.
3119 if Esize
(E
) / SSU
> Ttypes
.Maximum_Alignment
then
3120 S
:= Ttypes
.Maximum_Alignment
;
3122 S
:= UI_To_Int
(Esize
(E
)) / SSU
;
3125 -- If the default alignment of "double" floating-point types is
3126 -- specifically capped, enforce the cap.
3128 if Ttypes
.Target_Double_Float_Alignment
> 0
3130 and then Is_Floating_Point_Type
(E
)
3132 Max_Alignment
:= Ttypes
.Target_Double_Float_Alignment
;
3134 -- If the default alignment of "double" or larger scalar types is
3135 -- specifically capped, enforce the cap.
3137 elsif Ttypes
.Target_Double_Scalar_Alignment
> 0
3139 and then Is_Scalar_Type
(E
)
3141 Max_Alignment
:= Ttypes
.Target_Double_Scalar_Alignment
;
3143 -- Otherwise enforce the overall alignment cap
3146 Max_Alignment
:= Ttypes
.Maximum_Alignment
;
3150 while 2 * A
<= Max_Alignment
and then 2 * A
<= S
loop
3154 -- If alignment is currently not set, then we can safetly set it to
3155 -- this new calculated value.
3157 if Unknown_Alignment
(E
) then
3158 Init_Alignment
(E
, A
);
3160 -- Cases where we have inherited an alignment
3162 -- For constructed types, always reset the alignment, these are
3163 -- Generally invisible to the user anyway, and that way we are
3164 -- sure that no constructed types have weird alignments.
3166 elsif not Comes_From_Source
(E
) then
3167 Init_Alignment
(E
, A
);
3169 -- If this inherited alignment is the same as the one we computed,
3170 -- then obviously everything is fine, and we do not need to reset it.
3172 elsif Alignment
(E
) = A
then
3175 -- Now we come to the difficult cases where we have inherited an
3176 -- alignment and size, but overridden the size but not the alignment.
3178 elsif Has_Size_Clause
(E
) or else Has_Object_Size_Clause
(E
) then
3180 -- This is tricky, it might be thought that we should try to
3181 -- inherit the alignment, since that's what the RM implies, but
3182 -- that leads to complex rules and oddities. Consider for example:
3184 -- type R is new Character;
3185 -- for R'Size use 16;
3187 -- It seems quite bogus in this case to inherit an alignment of 1
3188 -- from the parent type Character. Furthermore, if that's what the
3189 -- programmer really wanted for some odd reason, then they could
3190 -- specify the alignment they wanted.
3192 -- Furthermore we really don't want to inherit the alignment in
3193 -- the case of a specified Object_Size for a subtype, since then
3194 -- there would be no way of overriding to give a reasonable value
3195 -- (we don't have an Object_Subtype attribute). Consider:
3197 -- subtype R is new Character;
3198 -- for R'Object_Size use 16;
3200 -- If we inherit the alignment of 1, then we have an odd
3201 -- inefficient alignment for the subtype, which cannot be fixed.
3203 -- So we make the decision that if Size (or Object_Size) is given
3204 -- (and, in the case of a first subtype, the alignment is not set
3205 -- with a specific alignment clause). We reset the alignment to
3206 -- the appropriate value for the specified size. This is a nice
3207 -- simple rule to implement and document.
3209 -- There is one slight glitch, which is that a confirming size
3210 -- clause can now change the alignment, which, if we really think
3211 -- that confirming rep clauses should have no effect, is a no-no.
3213 -- type R is new Character;
3214 -- for R'Alignment use 2;
3216 -- for S'Size use Character'Size;
3218 -- Now the alignment of S is 1 instead of 2, as a result of
3219 -- applying the above rule to the confirming rep clause for S. Not
3220 -- clear this is worth worrying about. If we recorded whether a
3221 -- size clause was confirming we could avoid this, but right now
3222 -- we have no way of doing that or easily figuring it out, so we
3225 -- Historical note. In versions of GNAT prior to Nov 6th, 2010, an
3226 -- odd distinction was made between inherited alignments greater
3227 -- than the computed alignment (where the larger alignment was
3228 -- inherited) and inherited alignments smaller than the computed
3229 -- alignment (where the smaller alignment was overridden). This
3230 -- was a dubious fix to get around an ACATS problem which seems
3231 -- to have disappeared anyway, and in any case, this peculiarity
3232 -- was never documented.
3234 Init_Alignment
(E
, A
);
3236 -- If no Size (or Object_Size) was specified, then we inherited the
3237 -- object size, so we should inherit the alignment as well and not
3238 -- modify it. This takes care of cases like:
3240 -- type R is new Integer;
3241 -- for R'Alignment use 1;
3244 -- Here we have R has a default Object_Size of 32, and a specified
3245 -- alignment of 1, and it seeems right for S to inherit both values.
3251 end Set_Elem_Alignment
;
3253 ----------------------
3254 -- SO_Ref_From_Expr --
3255 ----------------------
3257 function SO_Ref_From_Expr
3259 Ins_Type
: Entity_Id
;
3260 Vtype
: Entity_Id
:= Empty
;
3261 Make_Func
: Boolean := False) return Dynamic_SO_Ref
3263 Loc
: constant Source_Ptr
:= Sloc
(Ins_Type
);
3264 K
: constant Entity_Id
:= Make_Temporary
(Loc
, 'K');
3267 Vtype_Primary_View
: Entity_Id
;
3269 function Check_Node_V_Ref
(N
: Node_Id
) return Traverse_Result
;
3270 -- Function used to check one node for reference to V
3272 function Has_V_Ref
is new Traverse_Func
(Check_Node_V_Ref
);
3273 -- Function used to traverse tree to check for reference to V
3275 ----------------------
3276 -- Check_Node_V_Ref --
3277 ----------------------
3279 function Check_Node_V_Ref
(N
: Node_Id
) return Traverse_Result
is
3281 if Nkind
(N
) = N_Identifier
then
3282 if Chars
(N
) = Vname
then
3291 end Check_Node_V_Ref
;
3293 -- Start of processing for SO_Ref_From_Expr
3296 -- Case of expression is an integer literal, in this case we just
3297 -- return the value (which must always be non-negative, since size
3298 -- and offset values can never be negative).
3300 if Nkind
(Expr
) = N_Integer_Literal
then
3301 pragma Assert
(Intval
(Expr
) >= 0);
3302 return Intval
(Expr
);
3305 -- Case where there is a reference to V, create function
3307 if Has_V_Ref
(Expr
) = Abandon
then
3309 pragma Assert
(Present
(Vtype
));
3311 -- Check whether Vtype is a view of a private type and ensure that
3312 -- we use the primary view of the type (which is denoted by its
3313 -- Etype, whether it's the type's partial or full view entity).
3314 -- This is needed to make sure that we use the same (primary) view
3315 -- of the type for all V formals, whether the current view of the
3316 -- type is the partial or full view, so that types will always
3317 -- match on calls from one size function to another.
3319 if Has_Private_Declaration
(Vtype
) then
3320 Vtype_Primary_View
:= Etype
(Vtype
);
3322 Vtype_Primary_View
:= Vtype
;
3325 Set_Is_Discrim_SO_Function
(K
);
3328 Make_Subprogram_Body
(Loc
,
3331 Make_Function_Specification
(Loc
,
3332 Defining_Unit_Name
=> K
,
3333 Parameter_Specifications
=> New_List
(
3334 Make_Parameter_Specification
(Loc
,
3335 Defining_Identifier
=>
3336 Make_Defining_Identifier
(Loc
, Chars
=> Vname
),
3338 New_Occurrence_Of
(Vtype_Primary_View
, Loc
))),
3339 Result_Definition
=>
3340 New_Occurrence_Of
(Standard_Unsigned
, Loc
)),
3342 Declarations
=> Empty_List
,
3344 Handled_Statement_Sequence
=>
3345 Make_Handled_Sequence_Of_Statements
(Loc
,
3346 Statements
=> New_List
(
3347 Make_Simple_Return_Statement
(Loc
,
3348 Expression
=> Expr
))));
3350 -- The caller requests that the expression be encapsulated in a
3351 -- parameterless function.
3353 elsif Make_Func
then
3355 Make_Subprogram_Body
(Loc
,
3358 Make_Function_Specification
(Loc
,
3359 Defining_Unit_Name
=> K
,
3360 Parameter_Specifications
=> Empty_List
,
3361 Result_Definition
=>
3362 New_Occurrence_Of
(Standard_Unsigned
, Loc
)),
3364 Declarations
=> Empty_List
,
3366 Handled_Statement_Sequence
=>
3367 Make_Handled_Sequence_Of_Statements
(Loc
,
3368 Statements
=> New_List
(
3369 Make_Simple_Return_Statement
(Loc
, Expression
=> Expr
))));
3371 -- No reference to V and function not requested, so create a constant
3375 Make_Object_Declaration
(Loc
,
3376 Defining_Identifier
=> K
,
3377 Object_Definition
=>
3378 New_Occurrence_Of
(Standard_Unsigned
, Loc
),
3379 Constant_Present
=> True,
3380 Expression
=> Expr
);
3383 Append_Freeze_Action
(Ins_Type
, Decl
);
3385 return Create_Dynamic_SO_Ref
(K
);
3386 end SO_Ref_From_Expr
;