1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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 Einfo
; use Einfo
;
29 with Errout
; use Errout
;
30 with Exp_Tss
; use Exp_Tss
;
31 with Exp_Util
; use Exp_Util
;
33 with Lib
.Xref
; use Lib
.Xref
;
34 with Namet
; use Namet
;
35 with Nlists
; use Nlists
;
36 with Nmake
; use Nmake
;
38 with Restrict
; use Restrict
;
39 with Rident
; use Rident
;
40 with Rtsfind
; use Rtsfind
;
42 with Sem_Aux
; use Sem_Aux
;
43 with Sem_Ch8
; use Sem_Ch8
;
44 with Sem_Eval
; use Sem_Eval
;
45 with Sem_Res
; use Sem_Res
;
46 with Sem_Type
; use Sem_Type
;
47 with Sem_Util
; use Sem_Util
;
48 with Sem_Warn
; use Sem_Warn
;
49 with Snames
; use Snames
;
50 with Stand
; use Stand
;
51 with Sinfo
; use Sinfo
;
53 with Targparm
; use Targparm
;
54 with Ttypes
; use Ttypes
;
55 with Tbuild
; use Tbuild
;
56 with Urealp
; use Urealp
;
58 with GNAT
.Heap_Sort_G
;
60 package body Sem_Ch13
is
62 SSU
: constant Pos
:= System_Storage_Unit
;
63 -- Convenient short hand for commonly used constant
65 -----------------------
66 -- Local Subprograms --
67 -----------------------
69 procedure Alignment_Check_For_Esize_Change
(Typ
: Entity_Id
);
70 -- This routine is called after setting the Esize of type entity Typ.
71 -- The purpose is to deal with the situation where an alignment has been
72 -- inherited from a derived type that is no longer appropriate for the
73 -- new Esize value. In this case, we reset the Alignment to unknown.
75 procedure Check_Component_Overlap
(C1_Ent
, C2_Ent
: Entity_Id
);
76 -- Given two entities for record components or discriminants, checks
77 -- if they have overlapping component clauses and issues errors if so.
79 function Get_Alignment_Value
(Expr
: Node_Id
) return Uint
;
80 -- Given the expression for an alignment value, returns the corresponding
81 -- Uint value. If the value is inappropriate, then error messages are
82 -- posted as required, and a value of No_Uint is returned.
84 function Is_Operational_Item
(N
: Node_Id
) return Boolean;
85 -- A specification for a stream attribute is allowed before the full
86 -- type is declared, as explained in AI-00137 and the corrigendum.
87 -- Attributes that do not specify a representation characteristic are
88 -- operational attributes.
90 function Address_Aliased_Entity
(N
: Node_Id
) return Entity_Id
;
91 -- If expression N is of the form E'Address, return E
93 procedure New_Stream_Subprogram
98 -- Create a subprogram renaming of a given stream attribute to the
99 -- designated subprogram and then in the tagged case, provide this as a
100 -- primitive operation, or in the non-tagged case make an appropriate TSS
101 -- entry. This is more properly an expansion activity than just semantics,
102 -- but the presence of user-defined stream functions for limited types is a
103 -- legality check, which is why this takes place here rather than in
104 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
105 -- function to be generated.
107 -- To avoid elaboration anomalies with freeze nodes, for untagged types
108 -- we generate both a subprogram declaration and a subprogram renaming
109 -- declaration, so that the attribute specification is handled as a
110 -- renaming_as_body. For tagged types, the specification is one of the
113 ----------------------------------------------
114 -- Table for Validate_Unchecked_Conversions --
115 ----------------------------------------------
117 -- The following table collects unchecked conversions for validation.
118 -- Entries are made by Validate_Unchecked_Conversion and then the
119 -- call to Validate_Unchecked_Conversions does the actual error
120 -- checking and posting of warnings. The reason for this delayed
121 -- processing is to take advantage of back-annotations of size and
122 -- alignment values performed by the back end.
124 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
125 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
126 -- will already have modified all Sloc values if the -gnatD option is set.
128 type UC_Entry
is record
129 Eloc
: Source_Ptr
; -- node used for posting warnings
130 Source
: Entity_Id
; -- source type for unchecked conversion
131 Target
: Entity_Id
; -- target type for unchecked conversion
134 package Unchecked_Conversions
is new Table
.Table
(
135 Table_Component_Type
=> UC_Entry
,
136 Table_Index_Type
=> Int
,
137 Table_Low_Bound
=> 1,
139 Table_Increment
=> 200,
140 Table_Name
=> "Unchecked_Conversions");
142 ----------------------------------------
143 -- Table for Validate_Address_Clauses --
144 ----------------------------------------
146 -- If an address clause has the form
148 -- for X'Address use Expr
150 -- where Expr is of the form Y'Address or recursively is a reference
151 -- to a constant of either of these forms, and X and Y are entities of
152 -- objects, then if Y has a smaller alignment than X, that merits a
153 -- warning about possible bad alignment. The following table collects
154 -- address clauses of this kind. We put these in a table so that they
155 -- can be checked after the back end has completed annotation of the
156 -- alignments of objects, since we can catch more cases that way.
158 type Address_Clause_Check_Record
is record
160 -- The address clause
163 -- The entity of the object overlaying Y
166 -- The entity of the object being overlaid
169 package Address_Clause_Checks
is new Table
.Table
(
170 Table_Component_Type
=> Address_Clause_Check_Record
,
171 Table_Index_Type
=> Int
,
172 Table_Low_Bound
=> 1,
174 Table_Increment
=> 200,
175 Table_Name
=> "Address_Clause_Checks");
177 ----------------------------
178 -- Address_Aliased_Entity --
179 ----------------------------
181 function Address_Aliased_Entity
(N
: Node_Id
) return Entity_Id
is
183 if Nkind
(N
) = N_Attribute_Reference
184 and then Attribute_Name
(N
) = Name_Address
191 while Nkind_In
(P
, N_Selected_Component
, N_Indexed_Component
) loop
195 if Is_Entity_Name
(P
) then
202 end Address_Aliased_Entity
;
204 -----------------------------------------
205 -- Adjust_Record_For_Reverse_Bit_Order --
206 -----------------------------------------
208 procedure Adjust_Record_For_Reverse_Bit_Order
(R
: Entity_Id
) is
209 Max_Machine_Scalar_Size
: constant Uint
:=
211 (Standard_Long_Long_Integer_Size
);
212 -- We use this as the maximum machine scalar size in the sense of AI-133
216 SSU
: constant Uint
:= UI_From_Int
(System_Storage_Unit
);
219 -- This first loop through components does two things. First it deals
220 -- with the case of components with component clauses whose length is
221 -- greater than the maximum machine scalar size (either accepting them
222 -- or rejecting as needed). Second, it counts the number of components
223 -- with component clauses whose length does not exceed this maximum for
227 Comp
:= First_Component_Or_Discriminant
(R
);
228 while Present
(Comp
) loop
230 CC
: constant Node_Id
:= Component_Clause
(Comp
);
235 Fbit
: constant Uint
:= Static_Integer
(First_Bit
(CC
));
238 -- Case of component with size > max machine scalar
240 if Esize
(Comp
) > Max_Machine_Scalar_Size
then
242 -- Must begin on byte boundary
244 if Fbit
mod SSU
/= 0 then
246 ("illegal first bit value for reverse bit order",
248 Error_Msg_Uint_1
:= SSU
;
249 Error_Msg_Uint_2
:= Max_Machine_Scalar_Size
;
252 ("\must be a multiple of ^ if size greater than ^",
255 -- Must end on byte boundary
257 elsif Esize
(Comp
) mod SSU
/= 0 then
259 ("illegal last bit value for reverse bit order",
261 Error_Msg_Uint_1
:= SSU
;
262 Error_Msg_Uint_2
:= Max_Machine_Scalar_Size
;
265 ("\must be a multiple of ^ if size greater than ^",
268 -- OK, give warning if enabled
270 elsif Warn_On_Reverse_Bit_Order
then
272 ("multi-byte field specified with non-standard"
273 & " Bit_Order?", CC
);
275 if Bytes_Big_Endian
then
277 ("\bytes are not reversed "
278 & "(component is big-endian)?", CC
);
281 ("\bytes are not reversed "
282 & "(component is little-endian)?", CC
);
286 -- Case where size is not greater than max machine
287 -- scalar. For now, we just count these.
290 Num_CC
:= Num_CC
+ 1;
296 Next_Component_Or_Discriminant
(Comp
);
299 -- We need to sort the component clauses on the basis of the Position
300 -- values in the clause, so we can group clauses with the same Position.
301 -- together to determine the relevant machine scalar size.
304 Comps
: array (0 .. Num_CC
) of Entity_Id
;
305 -- Array to collect component and discriminant entities. The data
306 -- starts at index 1, the 0'th entry is for the sort routine.
308 function CP_Lt
(Op1
, Op2
: Natural) return Boolean;
309 -- Compare routine for Sort
311 procedure CP_Move
(From
: Natural; To
: Natural);
312 -- Move routine for Sort
314 package Sorting
is new GNAT
.Heap_Sort_G
(CP_Move
, CP_Lt
);
318 -- Start and stop positions in component list of set of components
319 -- with the same starting position (that constitute components in
320 -- a single machine scalar).
323 -- Maximum last bit value of any component in this set
326 -- Corresponding machine scalar size
332 function CP_Lt
(Op1
, Op2
: Natural) return Boolean is
334 return Position
(Component_Clause
(Comps
(Op1
))) <
335 Position
(Component_Clause
(Comps
(Op2
)));
342 procedure CP_Move
(From
: Natural; To
: Natural) is
344 Comps
(To
) := Comps
(From
);
348 -- Collect the component clauses
351 Comp
:= First_Component_Or_Discriminant
(R
);
352 while Present
(Comp
) loop
353 if Present
(Component_Clause
(Comp
))
354 and then Esize
(Comp
) <= Max_Machine_Scalar_Size
356 Num_CC
:= Num_CC
+ 1;
357 Comps
(Num_CC
) := Comp
;
360 Next_Component_Or_Discriminant
(Comp
);
363 -- Sort by ascending position number
365 Sorting
.Sort
(Num_CC
);
367 -- We now have all the components whose size does not exceed the max
368 -- machine scalar value, sorted by starting position. In this loop
369 -- we gather groups of clauses starting at the same position, to
370 -- process them in accordance with Ada 2005 AI-133.
373 while Stop
< Num_CC
loop
377 Static_Integer
(Last_Bit
(Component_Clause
(Comps
(Start
))));
378 while Stop
< Num_CC
loop
380 (Position
(Component_Clause
(Comps
(Stop
+ 1)))) =
382 (Position
(Component_Clause
(Comps
(Stop
))))
389 (Last_Bit
(Component_Clause
(Comps
(Stop
)))));
395 -- Now we have a group of component clauses from Start to Stop
396 -- whose positions are identical, and MaxL is the maximum last bit
397 -- value of any of these components.
399 -- We need to determine the corresponding machine scalar size.
400 -- This loop assumes that machine scalar sizes are even, and that
401 -- each possible machine scalar has twice as many bits as the
404 MSS
:= Max_Machine_Scalar_Size
;
406 and then (MSS
/ 2) >= SSU
407 and then (MSS
/ 2) > MaxL
412 -- Here is where we fix up the Component_Bit_Offset value to
413 -- account for the reverse bit order. Some examples of what needs
414 -- to be done for the case of a machine scalar size of 8 are:
416 -- First_Bit .. Last_Bit Component_Bit_Offset
428 -- The general rule is that the first bit is obtained by
429 -- subtracting the old ending bit from machine scalar size - 1.
431 for C
in Start
.. Stop
loop
433 Comp
: constant Entity_Id
:= Comps
(C
);
434 CC
: constant Node_Id
:= Component_Clause
(Comp
);
435 LB
: constant Uint
:= Static_Integer
(Last_Bit
(CC
));
436 NFB
: constant Uint
:= MSS
- Uint_1
- LB
;
437 NLB
: constant Uint
:= NFB
+ Esize
(Comp
) - 1;
438 Pos
: constant Uint
:= Static_Integer
(Position
(CC
));
441 if Warn_On_Reverse_Bit_Order
then
442 Error_Msg_Uint_1
:= MSS
;
444 ("info: reverse bit order in machine " &
445 "scalar of length^?", First_Bit
(CC
));
446 Error_Msg_Uint_1
:= NFB
;
447 Error_Msg_Uint_2
:= NLB
;
449 if Bytes_Big_Endian
then
451 ("?\info: big-endian range for "
452 & "component & is ^ .. ^",
453 First_Bit
(CC
), Comp
);
456 ("?\info: little-endian range "
457 & "for component & is ^ .. ^",
458 First_Bit
(CC
), Comp
);
462 Set_Component_Bit_Offset
(Comp
, Pos
* SSU
+ NFB
);
463 Set_Normalized_First_Bit
(Comp
, NFB
mod SSU
);
468 end Adjust_Record_For_Reverse_Bit_Order
;
470 --------------------------------------
471 -- Alignment_Check_For_Esize_Change --
472 --------------------------------------
474 procedure Alignment_Check_For_Esize_Change
(Typ
: Entity_Id
) is
476 -- If the alignment is known, and not set by a rep clause, and is
477 -- inconsistent with the size being set, then reset it to unknown,
478 -- we assume in this case that the size overrides the inherited
479 -- alignment, and that the alignment must be recomputed.
481 if Known_Alignment
(Typ
)
482 and then not Has_Alignment_Clause
(Typ
)
483 and then Esize
(Typ
) mod (Alignment
(Typ
) * SSU
) /= 0
485 Init_Alignment
(Typ
);
487 end Alignment_Check_For_Esize_Change
;
489 -----------------------
490 -- Analyze_At_Clause --
491 -----------------------
493 -- An at clause is replaced by the corresponding Address attribute
494 -- definition clause that is the preferred approach in Ada 95.
496 procedure Analyze_At_Clause
(N
: Node_Id
) is
497 CS
: constant Boolean := Comes_From_Source
(N
);
500 -- This is an obsolescent feature
502 Check_Restriction
(No_Obsolescent_Features
, N
);
504 if Warn_On_Obsolescent_Feature
then
506 ("at clause is an obsolescent feature (RM J.7(2))?", N
);
508 ("\use address attribute definition clause instead?", N
);
511 -- Rewrite as address clause
514 Make_Attribute_Definition_Clause
(Sloc
(N
),
515 Name
=> Identifier
(N
),
516 Chars
=> Name_Address
,
517 Expression
=> Expression
(N
)));
519 -- We preserve Comes_From_Source, since logically the clause still
520 -- comes from the source program even though it is changed in form.
522 Set_Comes_From_Source
(N
, CS
);
524 -- Analyze rewritten clause
526 Analyze_Attribute_Definition_Clause
(N
);
527 end Analyze_At_Clause
;
529 -----------------------------------------
530 -- Analyze_Attribute_Definition_Clause --
531 -----------------------------------------
533 procedure Analyze_Attribute_Definition_Clause
(N
: Node_Id
) is
534 Loc
: constant Source_Ptr
:= Sloc
(N
);
535 Nam
: constant Node_Id
:= Name
(N
);
536 Attr
: constant Name_Id
:= Chars
(N
);
537 Expr
: constant Node_Id
:= Expression
(N
);
538 Id
: constant Attribute_Id
:= Get_Attribute_Id
(Attr
);
542 FOnly
: Boolean := False;
543 -- Reset to True for subtype specific attribute (Alignment, Size)
544 -- and for stream attributes, i.e. those cases where in the call
545 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
546 -- rules are checked. Note that the case of stream attributes is not
547 -- clear from the RM, but see AI95-00137. Also, the RM seems to
548 -- disallow Storage_Size for derived task types, but that is also
549 -- clearly unintentional.
551 procedure Analyze_Stream_TSS_Definition
(TSS_Nam
: TSS_Name_Type
);
552 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
553 -- definition clauses.
555 -----------------------------------
556 -- Analyze_Stream_TSS_Definition --
557 -----------------------------------
559 procedure Analyze_Stream_TSS_Definition
(TSS_Nam
: TSS_Name_Type
) is
560 Subp
: Entity_Id
:= Empty
;
565 Is_Read
: constant Boolean := (TSS_Nam
= TSS_Stream_Read
);
567 function Has_Good_Profile
(Subp
: Entity_Id
) return Boolean;
568 -- Return true if the entity is a subprogram with an appropriate
569 -- profile for the attribute being defined.
571 ----------------------
572 -- Has_Good_Profile --
573 ----------------------
575 function Has_Good_Profile
(Subp
: Entity_Id
) return Boolean is
577 Is_Function
: constant Boolean := (TSS_Nam
= TSS_Stream_Input
);
578 Expected_Ekind
: constant array (Boolean) of Entity_Kind
:=
579 (False => E_Procedure
, True => E_Function
);
583 if Ekind
(Subp
) /= Expected_Ekind
(Is_Function
) then
587 F
:= First_Formal
(Subp
);
590 or else Ekind
(Etype
(F
)) /= E_Anonymous_Access_Type
591 or else Designated_Type
(Etype
(F
)) /=
592 Class_Wide_Type
(RTE
(RE_Root_Stream_Type
))
597 if not Is_Function
then
601 Expected_Mode
: constant array (Boolean) of Entity_Kind
:=
602 (False => E_In_Parameter
,
603 True => E_Out_Parameter
);
605 if Parameter_Mode
(F
) /= Expected_Mode
(Is_Read
) then
616 return Base_Type
(Typ
) = Base_Type
(Ent
)
617 and then No
(Next_Formal
(F
));
618 end Has_Good_Profile
;
620 -- Start of processing for Analyze_Stream_TSS_Definition
625 if not Is_Type
(U_Ent
) then
626 Error_Msg_N
("local name must be a subtype", Nam
);
630 Pnam
:= TSS
(Base_Type
(U_Ent
), TSS_Nam
);
632 -- If Pnam is present, it can be either inherited from an ancestor
633 -- type (in which case it is legal to redefine it for this type), or
634 -- be a previous definition of the attribute for the same type (in
635 -- which case it is illegal).
637 -- In the first case, it will have been analyzed already, and we
638 -- can check that its profile does not match the expected profile
639 -- for a stream attribute of U_Ent. In the second case, either Pnam
640 -- has been analyzed (and has the expected profile), or it has not
641 -- been analyzed yet (case of a type that has not been frozen yet
642 -- and for which the stream attribute has been set using Set_TSS).
645 and then (No
(First_Entity
(Pnam
)) or else Has_Good_Profile
(Pnam
))
647 Error_Msg_Sloc
:= Sloc
(Pnam
);
648 Error_Msg_Name_1
:= Attr
;
649 Error_Msg_N
("% attribute already defined #", Nam
);
655 if Is_Entity_Name
(Expr
) then
656 if not Is_Overloaded
(Expr
) then
657 if Has_Good_Profile
(Entity
(Expr
)) then
658 Subp
:= Entity
(Expr
);
662 Get_First_Interp
(Expr
, I
, It
);
663 while Present
(It
.Nam
) loop
664 if Has_Good_Profile
(It
.Nam
) then
669 Get_Next_Interp
(I
, It
);
674 if Present
(Subp
) then
675 if Is_Abstract_Subprogram
(Subp
) then
676 Error_Msg_N
("stream subprogram must not be abstract", Expr
);
680 Set_Entity
(Expr
, Subp
);
681 Set_Etype
(Expr
, Etype
(Subp
));
683 New_Stream_Subprogram
(N
, U_Ent
, Subp
, TSS_Nam
);
686 Error_Msg_Name_1
:= Attr
;
687 Error_Msg_N
("incorrect expression for% attribute", Expr
);
689 end Analyze_Stream_TSS_Definition
;
691 -- Start of processing for Analyze_Attribute_Definition_Clause
694 if Ignore_Rep_Clauses
then
697 -- The following should be ignored
699 when Attribute_Address |
700 Attribute_Alignment |
701 Attribute_Bit_Order |
702 Attribute_Component_Size |
703 Attribute_Machine_Radix |
704 Attribute_Object_Size |
707 Attribute_Stream_Size |
708 Attribute_Value_Size
=>
710 Rewrite
(N
, Make_Null_Statement
(Sloc
(N
)));
713 -- The following should not be ignored
715 when Attribute_External_Tag |
719 Attribute_Storage_Pool |
720 Attribute_Storage_Size |
724 -- Other cases are errors, which will be caught below
734 if Rep_Item_Too_Early
(Ent
, N
) then
738 -- Rep clause applies to full view of incomplete type or private type if
739 -- we have one (if not, this is a premature use of the type). However,
740 -- certain semantic checks need to be done on the specified entity (i.e.
741 -- the private view), so we save it in Ent.
743 if Is_Private_Type
(Ent
)
744 and then Is_Derived_Type
(Ent
)
745 and then not Is_Tagged_Type
(Ent
)
746 and then No
(Full_View
(Ent
))
748 -- If this is a private type whose completion is a derivation from
749 -- another private type, there is no full view, and the attribute
750 -- belongs to the type itself, not its underlying parent.
754 elsif Ekind
(Ent
) = E_Incomplete_Type
then
756 -- The attribute applies to the full view, set the entity of the
757 -- attribute definition accordingly.
759 Ent
:= Underlying_Type
(Ent
);
761 Set_Entity
(Nam
, Ent
);
764 U_Ent
:= Underlying_Type
(Ent
);
767 -- Complete other routine error checks
769 if Etype
(Nam
) = Any_Type
then
772 elsif Scope
(Ent
) /= Current_Scope
then
773 Error_Msg_N
("entity must be declared in this scope", Nam
);
776 elsif No
(U_Ent
) then
779 elsif Is_Type
(U_Ent
)
780 and then not Is_First_Subtype
(U_Ent
)
781 and then Id
/= Attribute_Object_Size
782 and then Id
/= Attribute_Value_Size
783 and then not From_At_Mod
(N
)
785 Error_Msg_N
("cannot specify attribute for subtype", Nam
);
789 -- Switch on particular attribute
797 -- Address attribute definition clause
799 when Attribute_Address
=> Address
: begin
801 -- A little error check, catch for X'Address use X'Address;
803 if Nkind
(Nam
) = N_Identifier
804 and then Nkind
(Expr
) = N_Attribute_Reference
805 and then Attribute_Name
(Expr
) = Name_Address
806 and then Nkind
(Prefix
(Expr
)) = N_Identifier
807 and then Chars
(Nam
) = Chars
(Prefix
(Expr
))
810 ("address for & is self-referencing", Prefix
(Expr
), Ent
);
814 -- Not that special case, carry on with analysis of expression
816 Analyze_And_Resolve
(Expr
, RTE
(RE_Address
));
818 if Present
(Address_Clause
(U_Ent
)) then
819 Error_Msg_N
("address already given for &", Nam
);
821 -- Case of address clause for subprogram
823 elsif Is_Subprogram
(U_Ent
) then
824 if Has_Homonym
(U_Ent
) then
826 ("address clause cannot be given " &
827 "for overloaded subprogram",
832 -- For subprograms, all address clauses are permitted, and we
833 -- mark the subprogram as having a deferred freeze so that Gigi
834 -- will not elaborate it too soon.
836 -- Above needs more comments, what is too soon about???
838 Set_Has_Delayed_Freeze
(U_Ent
);
840 -- Case of address clause for entry
842 elsif Ekind
(U_Ent
) = E_Entry
then
843 if Nkind
(Parent
(N
)) = N_Task_Body
then
845 ("entry address must be specified in task spec", Nam
);
849 -- For entries, we require a constant address
851 Check_Constant_Address_Clause
(Expr
, U_Ent
);
853 -- Special checks for task types
855 if Is_Task_Type
(Scope
(U_Ent
))
856 and then Comes_From_Source
(Scope
(U_Ent
))
859 ("?entry address declared for entry in task type", N
);
861 ("\?only one task can be declared of this type", N
);
864 -- Entry address clauses are obsolescent
866 Check_Restriction
(No_Obsolescent_Features
, N
);
868 if Warn_On_Obsolescent_Feature
then
870 ("attaching interrupt to task entry is an " &
871 "obsolescent feature (RM J.7.1)?", N
);
873 ("\use interrupt procedure instead?", N
);
876 -- Case of an address clause for a controlled object which we
877 -- consider to be erroneous.
879 elsif Is_Controlled
(Etype
(U_Ent
))
880 or else Has_Controlled_Component
(Etype
(U_Ent
))
883 ("?controlled object& must not be overlaid", Nam
, U_Ent
);
885 ("\?Program_Error will be raised at run time", Nam
);
886 Insert_Action
(Declaration_Node
(U_Ent
),
887 Make_Raise_Program_Error
(Loc
,
888 Reason
=> PE_Overlaid_Controlled_Object
));
891 -- Case of address clause for a (non-controlled) object
894 Ekind
(U_Ent
) = E_Variable
896 Ekind
(U_Ent
) = E_Constant
899 Expr
: constant Node_Id
:= Expression
(N
);
900 Aent
: constant Entity_Id
:= Address_Aliased_Entity
(Expr
);
901 Ent_Y
: constant Entity_Id
:= Find_Overlaid_Object
(N
);
904 -- Exported variables cannot have an address clause,
905 -- because this cancels the effect of the pragma Export
907 if Is_Exported
(U_Ent
) then
909 ("cannot export object with address clause", Nam
);
912 -- Overlaying controlled objects is erroneous
915 and then (Has_Controlled_Component
(Etype
(Aent
))
916 or else Is_Controlled
(Etype
(Aent
)))
919 ("?cannot overlay with controlled object", Expr
);
921 ("\?Program_Error will be raised at run time", Expr
);
922 Insert_Action
(Declaration_Node
(U_Ent
),
923 Make_Raise_Program_Error
(Loc
,
924 Reason
=> PE_Overlaid_Controlled_Object
));
928 and then Ekind
(U_Ent
) = E_Constant
929 and then Ekind
(Aent
) /= E_Constant
931 Error_Msg_N
("constant overlays a variable?", Expr
);
933 elsif Present
(Renamed_Object
(U_Ent
)) then
935 ("address clause not allowed"
936 & " for a renaming declaration (RM 13.1(6))", Nam
);
939 -- Imported variables can have an address clause, but then
940 -- the import is pretty meaningless except to suppress
941 -- initializations, so we do not need such variables to
942 -- be statically allocated (and in fact it causes trouble
943 -- if the address clause is a local value).
945 elsif Is_Imported
(U_Ent
) then
946 Set_Is_Statically_Allocated
(U_Ent
, False);
949 -- We mark a possible modification of a variable with an
950 -- address clause, since it is likely aliasing is occurring.
952 Note_Possible_Modification
(Nam
, Sure
=> False);
954 -- Here we are checking for explicit overlap of one variable
955 -- by another, and if we find this then mark the overlapped
956 -- variable as also being volatile to prevent unwanted
959 if Present
(Ent_Y
) then
960 Set_Treat_As_Volatile
(Ent_Y
);
963 -- Legality checks on the address clause for initialized
964 -- objects is deferred until the freeze point, because
965 -- a subsequent pragma might indicate that the object is
966 -- imported and thus not initialized.
968 Set_Has_Delayed_Freeze
(U_Ent
);
970 if Is_Exported
(U_Ent
) then
972 ("& cannot be exported if an address clause is given",
975 ("\define and export a variable " &
976 "that holds its address instead",
980 -- Entity has delayed freeze, so we will generate an
981 -- alignment check at the freeze point unless suppressed.
983 if not Range_Checks_Suppressed
(U_Ent
)
984 and then not Alignment_Checks_Suppressed
(U_Ent
)
986 Set_Check_Address_Alignment
(N
);
989 -- Kill the size check code, since we are not allocating
990 -- the variable, it is somewhere else.
992 Kill_Size_Check_Code
(U_Ent
);
995 -- If the address clause is of the form:
997 -- for Y'Address use X'Address
1001 -- Const : constant Address := X'Address;
1003 -- for Y'Address use Const;
1005 -- then we make an entry in the table for checking the size and
1006 -- alignment of the overlaying variable. We defer this check
1007 -- till after code generation to take full advantage of the
1008 -- annotation done by the back end. This entry is only made if
1009 -- we have not already posted a warning about size/alignment
1010 -- (some warnings of this type are posted in Checks), and if
1011 -- the address clause comes from source.
1013 if Address_Clause_Overlay_Warnings
1014 and then Comes_From_Source
(N
)
1017 Ent_X
: Entity_Id
:= Empty
;
1018 Ent_Y
: Entity_Id
:= Empty
;
1021 Ent_Y
:= Find_Overlaid_Object
(N
);
1023 if Present
(Ent_Y
) and then Is_Entity_Name
(Name
(N
)) then
1024 Ent_X
:= Entity
(Name
(N
));
1025 Address_Clause_Checks
.Append
((N
, Ent_X
, Ent_Y
));
1027 -- If variable overlays a constant view, and we are
1028 -- warning on overlays, then mark the variable as
1029 -- overlaying a constant (we will give warnings later
1030 -- if this variable is assigned).
1032 if Is_Constant_Object
(Ent_Y
)
1033 and then Ekind
(Ent_X
) = E_Variable
1035 Set_Overlays_Constant
(Ent_X
);
1041 -- Not a valid entity for an address clause
1044 Error_Msg_N
("address cannot be given for &", Nam
);
1052 -- Alignment attribute definition clause
1054 when Attribute_Alignment
=> Alignment_Block
: declare
1055 Align
: constant Uint
:= Get_Alignment_Value
(Expr
);
1060 if not Is_Type
(U_Ent
)
1061 and then Ekind
(U_Ent
) /= E_Variable
1062 and then Ekind
(U_Ent
) /= E_Constant
1064 Error_Msg_N
("alignment cannot be given for &", Nam
);
1066 elsif Has_Alignment_Clause
(U_Ent
) then
1067 Error_Msg_Sloc
:= Sloc
(Alignment_Clause
(U_Ent
));
1068 Error_Msg_N
("alignment clause previously given#", N
);
1070 elsif Align
/= No_Uint
then
1071 Set_Has_Alignment_Clause
(U_Ent
);
1072 Set_Alignment
(U_Ent
, Align
);
1074 end Alignment_Block
;
1080 -- Bit_Order attribute definition clause
1082 when Attribute_Bit_Order
=> Bit_Order
: declare
1084 if not Is_Record_Type
(U_Ent
) then
1086 ("Bit_Order can only be defined for record type", Nam
);
1089 Analyze_And_Resolve
(Expr
, RTE
(RE_Bit_Order
));
1091 if Etype
(Expr
) = Any_Type
then
1094 elsif not Is_Static_Expression
(Expr
) then
1095 Flag_Non_Static_Expr
1096 ("Bit_Order requires static expression!", Expr
);
1099 if (Expr_Value
(Expr
) = 0) /= Bytes_Big_Endian
then
1100 Set_Reverse_Bit_Order
(U_Ent
, True);
1106 --------------------
1107 -- Component_Size --
1108 --------------------
1110 -- Component_Size attribute definition clause
1112 when Attribute_Component_Size
=> Component_Size_Case
: declare
1113 Csize
: constant Uint
:= Static_Integer
(Expr
);
1116 New_Ctyp
: Entity_Id
;
1120 if not Is_Array_Type
(U_Ent
) then
1121 Error_Msg_N
("component size requires array type", Nam
);
1125 Btype
:= Base_Type
(U_Ent
);
1127 if Has_Component_Size_Clause
(Btype
) then
1129 ("component size clause for& previously given", Nam
);
1131 elsif Csize
/= No_Uint
then
1132 Check_Size
(Expr
, Component_Type
(Btype
), Csize
, Biased
);
1134 if Has_Aliased_Components
(Btype
)
1137 and then Csize
/= 16
1140 ("component size incorrect for aliased components", N
);
1144 -- For the biased case, build a declaration for a subtype
1145 -- that will be used to represent the biased subtype that
1146 -- reflects the biased representation of components. We need
1147 -- this subtype to get proper conversions on referencing
1148 -- elements of the array. Note that component size clauses
1149 -- are ignored in VM mode.
1151 if VM_Target
= No_VM
then
1154 Make_Defining_Identifier
(Loc
,
1156 New_External_Name
(Chars
(U_Ent
), 'C', 0, 'T'));
1159 Make_Subtype_Declaration
(Loc
,
1160 Defining_Identifier
=> New_Ctyp
,
1161 Subtype_Indication
=>
1162 New_Occurrence_Of
(Component_Type
(Btype
), Loc
));
1164 Set_Parent
(Decl
, N
);
1165 Analyze
(Decl
, Suppress
=> All_Checks
);
1167 Set_Has_Delayed_Freeze
(New_Ctyp
, False);
1168 Set_Esize
(New_Ctyp
, Csize
);
1169 Set_RM_Size
(New_Ctyp
, Csize
);
1170 Init_Alignment
(New_Ctyp
);
1171 Set_Has_Biased_Representation
(New_Ctyp
, True);
1172 Set_Is_Itype
(New_Ctyp
, True);
1173 Set_Associated_Node_For_Itype
(New_Ctyp
, U_Ent
);
1175 Set_Component_Type
(Btype
, New_Ctyp
);
1177 if Warn_On_Biased_Representation
then
1179 ("?component size clause forces biased "
1180 & "representation", N
);
1184 Set_Component_Size
(Btype
, Csize
);
1186 -- For VM case, we ignore component size clauses
1189 -- Give a warning unless we are in GNAT mode, in which case
1190 -- the warning is suppressed since it is not useful.
1192 if not GNAT_Mode
then
1194 ("?component size ignored in this configuration", N
);
1198 Set_Has_Component_Size_Clause
(Btype
, True);
1199 Set_Has_Non_Standard_Rep
(Btype
, True);
1201 end Component_Size_Case
;
1207 when Attribute_External_Tag
=> External_Tag
:
1209 if not Is_Tagged_Type
(U_Ent
) then
1210 Error_Msg_N
("should be a tagged type", Nam
);
1213 Analyze_And_Resolve
(Expr
, Standard_String
);
1215 if not Is_Static_Expression
(Expr
) then
1216 Flag_Non_Static_Expr
1217 ("static string required for tag name!", Nam
);
1220 if VM_Target
= No_VM
then
1221 Set_Has_External_Tag_Rep_Clause
(U_Ent
);
1222 elsif not Inspector_Mode
then
1223 Error_Msg_Name_1
:= Attr
;
1225 ("% attribute unsupported in this configuration", Nam
);
1228 if not Is_Library_Level_Entity
(U_Ent
) then
1230 ("?non-unique external tag supplied for &", N
, U_Ent
);
1232 ("?\same external tag applies to all subprogram calls", N
);
1234 ("?\corresponding internal tag cannot be obtained", N
);
1242 when Attribute_Input
=>
1243 Analyze_Stream_TSS_Definition
(TSS_Stream_Input
);
1244 Set_Has_Specified_Stream_Input
(Ent
);
1250 -- Machine radix attribute definition clause
1252 when Attribute_Machine_Radix
=> Machine_Radix
: declare
1253 Radix
: constant Uint
:= Static_Integer
(Expr
);
1256 if not Is_Decimal_Fixed_Point_Type
(U_Ent
) then
1257 Error_Msg_N
("decimal fixed-point type expected for &", Nam
);
1259 elsif Has_Machine_Radix_Clause
(U_Ent
) then
1260 Error_Msg_Sloc
:= Sloc
(Alignment_Clause
(U_Ent
));
1261 Error_Msg_N
("machine radix clause previously given#", N
);
1263 elsif Radix
/= No_Uint
then
1264 Set_Has_Machine_Radix_Clause
(U_Ent
);
1265 Set_Has_Non_Standard_Rep
(Base_Type
(U_Ent
));
1269 elsif Radix
= 10 then
1270 Set_Machine_Radix_10
(U_Ent
);
1272 Error_Msg_N
("machine radix value must be 2 or 10", Expr
);
1281 -- Object_Size attribute definition clause
1283 when Attribute_Object_Size
=> Object_Size
: declare
1284 Size
: constant Uint
:= Static_Integer
(Expr
);
1287 pragma Warnings
(Off
, Biased
);
1290 if not Is_Type
(U_Ent
) then
1291 Error_Msg_N
("Object_Size cannot be given for &", Nam
);
1293 elsif Has_Object_Size_Clause
(U_Ent
) then
1294 Error_Msg_N
("Object_Size already given for &", Nam
);
1297 Check_Size
(Expr
, U_Ent
, Size
, Biased
);
1305 UI_Mod
(Size
, 64) /= 0
1308 ("Object_Size must be 8, 16, 32, or multiple of 64",
1312 Set_Esize
(U_Ent
, Size
);
1313 Set_Has_Object_Size_Clause
(U_Ent
);
1314 Alignment_Check_For_Esize_Change
(U_Ent
);
1322 when Attribute_Output
=>
1323 Analyze_Stream_TSS_Definition
(TSS_Stream_Output
);
1324 Set_Has_Specified_Stream_Output
(Ent
);
1330 when Attribute_Read
=>
1331 Analyze_Stream_TSS_Definition
(TSS_Stream_Read
);
1332 Set_Has_Specified_Stream_Read
(Ent
);
1338 -- Size attribute definition clause
1340 when Attribute_Size
=> Size
: declare
1341 Size
: constant Uint
:= Static_Integer
(Expr
);
1348 if Has_Size_Clause
(U_Ent
) then
1349 Error_Msg_N
("size already given for &", Nam
);
1351 elsif not Is_Type
(U_Ent
)
1352 and then Ekind
(U_Ent
) /= E_Variable
1353 and then Ekind
(U_Ent
) /= E_Constant
1355 Error_Msg_N
("size cannot be given for &", Nam
);
1357 elsif Is_Array_Type
(U_Ent
)
1358 and then not Is_Constrained
(U_Ent
)
1361 ("size cannot be given for unconstrained array", Nam
);
1363 elsif Size
/= No_Uint
then
1364 if Is_Type
(U_Ent
) then
1367 Etyp
:= Etype
(U_Ent
);
1370 -- Check size, note that Gigi is in charge of checking that the
1371 -- size of an array or record type is OK. Also we do not check
1372 -- the size in the ordinary fixed-point case, since it is too
1373 -- early to do so (there may be subsequent small clause that
1374 -- affects the size). We can check the size if a small clause
1375 -- has already been given.
1377 if not Is_Ordinary_Fixed_Point_Type
(U_Ent
)
1378 or else Has_Small_Clause
(U_Ent
)
1380 Check_Size
(Expr
, Etyp
, Size
, Biased
);
1381 Set_Has_Biased_Representation
(U_Ent
, Biased
);
1383 if Biased
and Warn_On_Biased_Representation
then
1385 ("?size clause forces biased representation", N
);
1389 -- For types set RM_Size and Esize if possible
1391 if Is_Type
(U_Ent
) then
1392 Set_RM_Size
(U_Ent
, Size
);
1394 -- For scalar types, increase Object_Size to power of 2, but
1395 -- not less than a storage unit in any case (i.e., normally
1396 -- this means it will be byte addressable).
1398 if Is_Scalar_Type
(U_Ent
) then
1399 if Size
<= System_Storage_Unit
then
1400 Init_Esize
(U_Ent
, System_Storage_Unit
);
1401 elsif Size
<= 16 then
1402 Init_Esize
(U_Ent
, 16);
1403 elsif Size
<= 32 then
1404 Init_Esize
(U_Ent
, 32);
1406 Set_Esize
(U_Ent
, (Size
+ 63) / 64 * 64);
1409 -- For all other types, object size = value size. The
1410 -- backend will adjust as needed.
1413 Set_Esize
(U_Ent
, Size
);
1416 Alignment_Check_For_Esize_Change
(U_Ent
);
1418 -- For objects, set Esize only
1421 if Is_Elementary_Type
(Etyp
) then
1422 if Size
/= System_Storage_Unit
1424 Size
/= System_Storage_Unit
* 2
1426 Size
/= System_Storage_Unit
* 4
1428 Size
/= System_Storage_Unit
* 8
1430 Error_Msg_Uint_1
:= UI_From_Int
(System_Storage_Unit
);
1431 Error_Msg_Uint_2
:= Error_Msg_Uint_1
* 8;
1433 ("size for primitive object must be a power of 2"
1434 & " in the range ^-^", N
);
1438 Set_Esize
(U_Ent
, Size
);
1441 Set_Has_Size_Clause
(U_Ent
);
1449 -- Small attribute definition clause
1451 when Attribute_Small
=> Small
: declare
1452 Implicit_Base
: constant Entity_Id
:= Base_Type
(U_Ent
);
1456 Analyze_And_Resolve
(Expr
, Any_Real
);
1458 if Etype
(Expr
) = Any_Type
then
1461 elsif not Is_Static_Expression
(Expr
) then
1462 Flag_Non_Static_Expr
1463 ("small requires static expression!", Expr
);
1467 Small
:= Expr_Value_R
(Expr
);
1469 if Small
<= Ureal_0
then
1470 Error_Msg_N
("small value must be greater than zero", Expr
);
1476 if not Is_Ordinary_Fixed_Point_Type
(U_Ent
) then
1478 ("small requires an ordinary fixed point type", Nam
);
1480 elsif Has_Small_Clause
(U_Ent
) then
1481 Error_Msg_N
("small already given for &", Nam
);
1483 elsif Small
> Delta_Value
(U_Ent
) then
1485 ("small value must not be greater then delta value", Nam
);
1488 Set_Small_Value
(U_Ent
, Small
);
1489 Set_Small_Value
(Implicit_Base
, Small
);
1490 Set_Has_Small_Clause
(U_Ent
);
1491 Set_Has_Small_Clause
(Implicit_Base
);
1492 Set_Has_Non_Standard_Rep
(Implicit_Base
);
1500 -- Storage_Pool attribute definition clause
1502 when Attribute_Storage_Pool
=> Storage_Pool
: declare
1507 if Ekind
(U_Ent
) = E_Access_Subprogram_Type
then
1509 ("storage pool cannot be given for access-to-subprogram type",
1513 elsif Ekind
(U_Ent
) /= E_Access_Type
1514 and then Ekind
(U_Ent
) /= E_General_Access_Type
1517 ("storage pool can only be given for access types", Nam
);
1520 elsif Is_Derived_Type
(U_Ent
) then
1522 ("storage pool cannot be given for a derived access type",
1525 elsif Has_Storage_Size_Clause
(U_Ent
) then
1526 Error_Msg_N
("storage size already given for &", Nam
);
1529 elsif Present
(Associated_Storage_Pool
(U_Ent
)) then
1530 Error_Msg_N
("storage pool already given for &", Nam
);
1535 (Expr
, Class_Wide_Type
(RTE
(RE_Root_Storage_Pool
)));
1537 if not Denotes_Variable
(Expr
) then
1538 Error_Msg_N
("storage pool must be a variable", Expr
);
1542 if Nkind
(Expr
) = N_Type_Conversion
then
1543 T
:= Etype
(Expression
(Expr
));
1548 -- The Stack_Bounded_Pool is used internally for implementing
1549 -- access types with a Storage_Size. Since it only work
1550 -- properly when used on one specific type, we need to check
1551 -- that it is not hijacked improperly:
1552 -- type T is access Integer;
1553 -- for T'Storage_Size use n;
1554 -- type Q is access Float;
1555 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1557 if RTE_Available
(RE_Stack_Bounded_Pool
)
1558 and then Base_Type
(T
) = RTE
(RE_Stack_Bounded_Pool
)
1560 Error_Msg_N
("non-shareable internal Pool", Expr
);
1564 -- If the argument is a name that is not an entity name, then
1565 -- we construct a renaming operation to define an entity of
1566 -- type storage pool.
1568 if not Is_Entity_Name
(Expr
)
1569 and then Is_Object_Reference
(Expr
)
1572 Make_Defining_Identifier
(Loc
,
1573 Chars
=> New_Internal_Name
('P'));
1576 Rnode
: constant Node_Id
:=
1577 Make_Object_Renaming_Declaration
(Loc
,
1578 Defining_Identifier
=> Pool
,
1580 New_Occurrence_Of
(Etype
(Expr
), Loc
),
1584 Insert_Before
(N
, Rnode
);
1586 Set_Associated_Storage_Pool
(U_Ent
, Pool
);
1589 elsif Is_Entity_Name
(Expr
) then
1590 Pool
:= Entity
(Expr
);
1592 -- If pool is a renamed object, get original one. This can
1593 -- happen with an explicit renaming, and within instances.
1595 while Present
(Renamed_Object
(Pool
))
1596 and then Is_Entity_Name
(Renamed_Object
(Pool
))
1598 Pool
:= Entity
(Renamed_Object
(Pool
));
1601 if Present
(Renamed_Object
(Pool
))
1602 and then Nkind
(Renamed_Object
(Pool
)) = N_Type_Conversion
1603 and then Is_Entity_Name
(Expression
(Renamed_Object
(Pool
)))
1605 Pool
:= Entity
(Expression
(Renamed_Object
(Pool
)));
1608 Set_Associated_Storage_Pool
(U_Ent
, Pool
);
1610 elsif Nkind
(Expr
) = N_Type_Conversion
1611 and then Is_Entity_Name
(Expression
(Expr
))
1612 and then Nkind
(Original_Node
(Expr
)) = N_Attribute_Reference
1614 Pool
:= Entity
(Expression
(Expr
));
1615 Set_Associated_Storage_Pool
(U_Ent
, Pool
);
1618 Error_Msg_N
("incorrect reference to a Storage Pool", Expr
);
1627 -- Storage_Size attribute definition clause
1629 when Attribute_Storage_Size
=> Storage_Size
: declare
1630 Btype
: constant Entity_Id
:= Base_Type
(U_Ent
);
1634 if Is_Task_Type
(U_Ent
) then
1635 Check_Restriction
(No_Obsolescent_Features
, N
);
1637 if Warn_On_Obsolescent_Feature
then
1639 ("storage size clause for task is an " &
1640 "obsolescent feature (RM J.9)?", N
);
1642 ("\use Storage_Size pragma instead?", N
);
1648 if not Is_Access_Type
(U_Ent
)
1649 and then Ekind
(U_Ent
) /= E_Task_Type
1651 Error_Msg_N
("storage size cannot be given for &", Nam
);
1653 elsif Is_Access_Type
(U_Ent
) and Is_Derived_Type
(U_Ent
) then
1655 ("storage size cannot be given for a derived access type",
1658 elsif Has_Storage_Size_Clause
(Btype
) then
1659 Error_Msg_N
("storage size already given for &", Nam
);
1662 Analyze_And_Resolve
(Expr
, Any_Integer
);
1664 if Is_Access_Type
(U_Ent
) then
1665 if Present
(Associated_Storage_Pool
(U_Ent
)) then
1666 Error_Msg_N
("storage pool already given for &", Nam
);
1670 if Compile_Time_Known_Value
(Expr
)
1671 and then Expr_Value
(Expr
) = 0
1673 Set_No_Pool_Assigned
(Btype
);
1676 else -- Is_Task_Type (U_Ent)
1677 Sprag
:= Get_Rep_Pragma
(Btype
, Name_Storage_Size
);
1679 if Present
(Sprag
) then
1680 Error_Msg_Sloc
:= Sloc
(Sprag
);
1682 ("Storage_Size already specified#", Nam
);
1687 Set_Has_Storage_Size_Clause
(Btype
);
1695 when Attribute_Stream_Size
=> Stream_Size
: declare
1696 Size
: constant Uint
:= Static_Integer
(Expr
);
1699 if Ada_Version
<= Ada_95
then
1700 Check_Restriction
(No_Implementation_Attributes
, N
);
1703 if Has_Stream_Size_Clause
(U_Ent
) then
1704 Error_Msg_N
("Stream_Size already given for &", Nam
);
1706 elsif Is_Elementary_Type
(U_Ent
) then
1707 if Size
/= System_Storage_Unit
1709 Size
/= System_Storage_Unit
* 2
1711 Size
/= System_Storage_Unit
* 4
1713 Size
/= System_Storage_Unit
* 8
1715 Error_Msg_Uint_1
:= UI_From_Int
(System_Storage_Unit
);
1717 ("stream size for elementary type must be a"
1718 & " power of 2 and at least ^", N
);
1720 elsif RM_Size
(U_Ent
) > Size
then
1721 Error_Msg_Uint_1
:= RM_Size
(U_Ent
);
1723 ("stream size for elementary type must be a"
1724 & " power of 2 and at least ^", N
);
1727 Set_Has_Stream_Size_Clause
(U_Ent
);
1730 Error_Msg_N
("Stream_Size cannot be given for &", Nam
);
1738 -- Value_Size attribute definition clause
1740 when Attribute_Value_Size
=> Value_Size
: declare
1741 Size
: constant Uint
:= Static_Integer
(Expr
);
1745 if not Is_Type
(U_Ent
) then
1746 Error_Msg_N
("Value_Size cannot be given for &", Nam
);
1749 (Get_Attribute_Definition_Clause
1750 (U_Ent
, Attribute_Value_Size
))
1752 Error_Msg_N
("Value_Size already given for &", Nam
);
1754 elsif Is_Array_Type
(U_Ent
)
1755 and then not Is_Constrained
(U_Ent
)
1758 ("Value_Size cannot be given for unconstrained array", Nam
);
1761 if Is_Elementary_Type
(U_Ent
) then
1762 Check_Size
(Expr
, U_Ent
, Size
, Biased
);
1763 Set_Has_Biased_Representation
(U_Ent
, Biased
);
1765 if Biased
and Warn_On_Biased_Representation
then
1767 ("?value size clause forces biased representation", N
);
1771 Set_RM_Size
(U_Ent
, Size
);
1779 when Attribute_Write
=>
1780 Analyze_Stream_TSS_Definition
(TSS_Stream_Write
);
1781 Set_Has_Specified_Stream_Write
(Ent
);
1783 -- All other attributes cannot be set
1787 ("attribute& cannot be set with definition clause", N
);
1790 -- The test for the type being frozen must be performed after
1791 -- any expression the clause has been analyzed since the expression
1792 -- itself might cause freezing that makes the clause illegal.
1794 if Rep_Item_Too_Late
(U_Ent
, N
, FOnly
) then
1797 end Analyze_Attribute_Definition_Clause
;
1799 ----------------------------
1800 -- Analyze_Code_Statement --
1801 ----------------------------
1803 procedure Analyze_Code_Statement
(N
: Node_Id
) is
1804 HSS
: constant Node_Id
:= Parent
(N
);
1805 SBody
: constant Node_Id
:= Parent
(HSS
);
1806 Subp
: constant Entity_Id
:= Current_Scope
;
1813 -- Analyze and check we get right type, note that this implements the
1814 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1815 -- is the only way that Asm_Insn could possibly be visible.
1817 Analyze_And_Resolve
(Expression
(N
));
1819 if Etype
(Expression
(N
)) = Any_Type
then
1821 elsif Etype
(Expression
(N
)) /= RTE
(RE_Asm_Insn
) then
1822 Error_Msg_N
("incorrect type for code statement", N
);
1826 Check_Code_Statement
(N
);
1828 -- Make sure we appear in the handled statement sequence of a
1829 -- subprogram (RM 13.8(3)).
1831 if Nkind
(HSS
) /= N_Handled_Sequence_Of_Statements
1832 or else Nkind
(SBody
) /= N_Subprogram_Body
1835 ("code statement can only appear in body of subprogram", N
);
1839 -- Do remaining checks (RM 13.8(3)) if not already done
1841 if not Is_Machine_Code_Subprogram
(Subp
) then
1842 Set_Is_Machine_Code_Subprogram
(Subp
);
1844 -- No exception handlers allowed
1846 if Present
(Exception_Handlers
(HSS
)) then
1848 ("exception handlers not permitted in machine code subprogram",
1849 First
(Exception_Handlers
(HSS
)));
1852 -- No declarations other than use clauses and pragmas (we allow
1853 -- certain internally generated declarations as well).
1855 Decl
:= First
(Declarations
(SBody
));
1856 while Present
(Decl
) loop
1857 DeclO
:= Original_Node
(Decl
);
1858 if Comes_From_Source
(DeclO
)
1859 and not Nkind_In
(DeclO
, N_Pragma
,
1860 N_Use_Package_Clause
,
1862 N_Implicit_Label_Declaration
)
1865 ("this declaration not allowed in machine code subprogram",
1872 -- No statements other than code statements, pragmas, and labels.
1873 -- Again we allow certain internally generated statements.
1875 Stmt
:= First
(Statements
(HSS
));
1876 while Present
(Stmt
) loop
1877 StmtO
:= Original_Node
(Stmt
);
1878 if Comes_From_Source
(StmtO
)
1879 and then not Nkind_In
(StmtO
, N_Pragma
,
1884 ("this statement is not allowed in machine code subprogram",
1891 end Analyze_Code_Statement
;
1893 -----------------------------------------------
1894 -- Analyze_Enumeration_Representation_Clause --
1895 -----------------------------------------------
1897 procedure Analyze_Enumeration_Representation_Clause
(N
: Node_Id
) is
1898 Ident
: constant Node_Id
:= Identifier
(N
);
1899 Aggr
: constant Node_Id
:= Array_Aggregate
(N
);
1900 Enumtype
: Entity_Id
;
1906 Err
: Boolean := False;
1908 Lo
: constant Uint
:= Expr_Value
(Type_Low_Bound
(Universal_Integer
));
1909 Hi
: constant Uint
:= Expr_Value
(Type_High_Bound
(Universal_Integer
));
1914 if Ignore_Rep_Clauses
then
1918 -- First some basic error checks
1921 Enumtype
:= Entity
(Ident
);
1923 if Enumtype
= Any_Type
1924 or else Rep_Item_Too_Early
(Enumtype
, N
)
1928 Enumtype
:= Underlying_Type
(Enumtype
);
1931 if not Is_Enumeration_Type
(Enumtype
) then
1933 ("enumeration type required, found}",
1934 Ident
, First_Subtype
(Enumtype
));
1938 -- Ignore rep clause on generic actual type. This will already have
1939 -- been flagged on the template as an error, and this is the safest
1940 -- way to ensure we don't get a junk cascaded message in the instance.
1942 if Is_Generic_Actual_Type
(Enumtype
) then
1945 -- Type must be in current scope
1947 elsif Scope
(Enumtype
) /= Current_Scope
then
1948 Error_Msg_N
("type must be declared in this scope", Ident
);
1951 -- Type must be a first subtype
1953 elsif not Is_First_Subtype
(Enumtype
) then
1954 Error_Msg_N
("cannot give enumeration rep clause for subtype", N
);
1957 -- Ignore duplicate rep clause
1959 elsif Has_Enumeration_Rep_Clause
(Enumtype
) then
1960 Error_Msg_N
("duplicate enumeration rep clause ignored", N
);
1963 -- Don't allow rep clause for standard [wide_[wide_]]character
1965 elsif Is_Standard_Character_Type
(Enumtype
) then
1966 Error_Msg_N
("enumeration rep clause not allowed for this type", N
);
1969 -- Check that the expression is a proper aggregate (no parentheses)
1971 elsif Paren_Count
(Aggr
) /= 0 then
1973 ("extra parentheses surrounding aggregate not allowed",
1977 -- All tests passed, so set rep clause in place
1980 Set_Has_Enumeration_Rep_Clause
(Enumtype
);
1981 Set_Has_Enumeration_Rep_Clause
(Base_Type
(Enumtype
));
1984 -- Now we process the aggregate. Note that we don't use the normal
1985 -- aggregate code for this purpose, because we don't want any of the
1986 -- normal expansion activities, and a number of special semantic
1987 -- rules apply (including the component type being any integer type)
1989 Elit
:= First_Literal
(Enumtype
);
1991 -- First the positional entries if any
1993 if Present
(Expressions
(Aggr
)) then
1994 Expr
:= First
(Expressions
(Aggr
));
1995 while Present
(Expr
) loop
1997 Error_Msg_N
("too many entries in aggregate", Expr
);
2001 Val
:= Static_Integer
(Expr
);
2003 -- Err signals that we found some incorrect entries processing
2004 -- the list. The final checks for completeness and ordering are
2005 -- skipped in this case.
2007 if Val
= No_Uint
then
2009 elsif Val
< Lo
or else Hi
< Val
then
2010 Error_Msg_N
("value outside permitted range", Expr
);
2014 Set_Enumeration_Rep
(Elit
, Val
);
2015 Set_Enumeration_Rep_Expr
(Elit
, Expr
);
2021 -- Now process the named entries if present
2023 if Present
(Component_Associations
(Aggr
)) then
2024 Assoc
:= First
(Component_Associations
(Aggr
));
2025 while Present
(Assoc
) loop
2026 Choice
:= First
(Choices
(Assoc
));
2028 if Present
(Next
(Choice
)) then
2030 ("multiple choice not allowed here", Next
(Choice
));
2034 if Nkind
(Choice
) = N_Others_Choice
then
2035 Error_Msg_N
("others choice not allowed here", Choice
);
2038 elsif Nkind
(Choice
) = N_Range
then
2039 -- ??? should allow zero/one element range here
2040 Error_Msg_N
("range not allowed here", Choice
);
2044 Analyze_And_Resolve
(Choice
, Enumtype
);
2046 if Is_Entity_Name
(Choice
)
2047 and then Is_Type
(Entity
(Choice
))
2049 Error_Msg_N
("subtype name not allowed here", Choice
);
2051 -- ??? should allow static subtype with zero/one entry
2053 elsif Etype
(Choice
) = Base_Type
(Enumtype
) then
2054 if not Is_Static_Expression
(Choice
) then
2055 Flag_Non_Static_Expr
2056 ("non-static expression used for choice!", Choice
);
2060 Elit
:= Expr_Value_E
(Choice
);
2062 if Present
(Enumeration_Rep_Expr
(Elit
)) then
2063 Error_Msg_Sloc
:= Sloc
(Enumeration_Rep_Expr
(Elit
));
2065 ("representation for& previously given#",
2070 Set_Enumeration_Rep_Expr
(Elit
, Choice
);
2072 Expr
:= Expression
(Assoc
);
2073 Val
:= Static_Integer
(Expr
);
2075 if Val
= No_Uint
then
2078 elsif Val
< Lo
or else Hi
< Val
then
2079 Error_Msg_N
("value outside permitted range", Expr
);
2083 Set_Enumeration_Rep
(Elit
, Val
);
2092 -- Aggregate is fully processed. Now we check that a full set of
2093 -- representations was given, and that they are in range and in order.
2094 -- These checks are only done if no other errors occurred.
2100 Elit
:= First_Literal
(Enumtype
);
2101 while Present
(Elit
) loop
2102 if No
(Enumeration_Rep_Expr
(Elit
)) then
2103 Error_Msg_NE
("missing representation for&!", N
, Elit
);
2106 Val
:= Enumeration_Rep
(Elit
);
2108 if Min
= No_Uint
then
2112 if Val
/= No_Uint
then
2113 if Max
/= No_Uint
and then Val
<= Max
then
2115 ("enumeration value for& not ordered!",
2116 Enumeration_Rep_Expr
(Elit
), Elit
);
2122 -- If there is at least one literal whose representation
2123 -- is not equal to the Pos value, then note that this
2124 -- enumeration type has a non-standard representation.
2126 if Val
/= Enumeration_Pos
(Elit
) then
2127 Set_Has_Non_Standard_Rep
(Base_Type
(Enumtype
));
2134 -- Now set proper size information
2137 Minsize
: Uint
:= UI_From_Int
(Minimum_Size
(Enumtype
));
2140 if Has_Size_Clause
(Enumtype
) then
2141 if Esize
(Enumtype
) >= Minsize
then
2146 UI_From_Int
(Minimum_Size
(Enumtype
, Biased
=> True));
2148 if Esize
(Enumtype
) < Minsize
then
2149 Error_Msg_N
("previously given size is too small", N
);
2152 Set_Has_Biased_Representation
(Enumtype
);
2157 Set_RM_Size
(Enumtype
, Minsize
);
2158 Set_Enum_Esize
(Enumtype
);
2161 Set_RM_Size
(Base_Type
(Enumtype
), RM_Size
(Enumtype
));
2162 Set_Esize
(Base_Type
(Enumtype
), Esize
(Enumtype
));
2163 Set_Alignment
(Base_Type
(Enumtype
), Alignment
(Enumtype
));
2167 -- We repeat the too late test in case it froze itself!
2169 if Rep_Item_Too_Late
(Enumtype
, N
) then
2172 end Analyze_Enumeration_Representation_Clause
;
2174 ----------------------------
2175 -- Analyze_Free_Statement --
2176 ----------------------------
2178 procedure Analyze_Free_Statement
(N
: Node_Id
) is
2180 Analyze
(Expression
(N
));
2181 end Analyze_Free_Statement
;
2183 ------------------------------------------
2184 -- Analyze_Record_Representation_Clause --
2185 ------------------------------------------
2187 procedure Analyze_Record_Representation_Clause
(N
: Node_Id
) is
2188 Loc
: constant Source_Ptr
:= Sloc
(N
);
2189 Ident
: constant Node_Id
:= Identifier
(N
);
2190 Rectype
: Entity_Id
;
2196 Hbit
: Uint
:= Uint_0
;
2201 Max_Bit_So_Far
: Uint
;
2202 -- Records the maximum bit position so far. If all field positions
2203 -- are monotonically increasing, then we can skip the circuit for
2204 -- checking for overlap, since no overlap is possible.
2206 Overlap_Check_Required
: Boolean;
2207 -- Used to keep track of whether or not an overlap check is required
2209 Ccount
: Natural := 0;
2210 -- Number of component clauses in record rep clause
2212 CR_Pragma
: Node_Id
:= Empty
;
2213 -- Points to N_Pragma node if Complete_Representation pragma present
2216 if Ignore_Rep_Clauses
then
2221 Rectype
:= Entity
(Ident
);
2223 if Rectype
= Any_Type
2224 or else Rep_Item_Too_Early
(Rectype
, N
)
2228 Rectype
:= Underlying_Type
(Rectype
);
2231 -- First some basic error checks
2233 if not Is_Record_Type
(Rectype
) then
2235 ("record type required, found}", Ident
, First_Subtype
(Rectype
));
2238 elsif Is_Unchecked_Union
(Rectype
) then
2240 ("record rep clause not allowed for Unchecked_Union", N
);
2242 elsif Scope
(Rectype
) /= Current_Scope
then
2243 Error_Msg_N
("type must be declared in this scope", N
);
2246 elsif not Is_First_Subtype
(Rectype
) then
2247 Error_Msg_N
("cannot give record rep clause for subtype", N
);
2250 elsif Has_Record_Rep_Clause
(Rectype
) then
2251 Error_Msg_N
("duplicate record rep clause ignored", N
);
2254 elsif Rep_Item_Too_Late
(Rectype
, N
) then
2258 if Present
(Mod_Clause
(N
)) then
2260 Loc
: constant Source_Ptr
:= Sloc
(N
);
2261 M
: constant Node_Id
:= Mod_Clause
(N
);
2262 P
: constant List_Id
:= Pragmas_Before
(M
);
2266 pragma Warnings
(Off
, Mod_Val
);
2269 Check_Restriction
(No_Obsolescent_Features
, Mod_Clause
(N
));
2271 if Warn_On_Obsolescent_Feature
then
2273 ("mod clause is an obsolescent feature (RM J.8)?", N
);
2275 ("\use alignment attribute definition clause instead?", N
);
2282 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2283 -- the Mod clause into an alignment clause anyway, so that the
2284 -- back-end can compute and back-annotate properly the size and
2285 -- alignment of types that may include this record.
2287 -- This seems dubious, this destroys the source tree in a manner
2288 -- not detectable by ASIS ???
2290 if Operating_Mode
= Check_Semantics
2294 Make_Attribute_Definition_Clause
(Loc
,
2295 Name
=> New_Reference_To
(Base_Type
(Rectype
), Loc
),
2296 Chars
=> Name_Alignment
,
2297 Expression
=> Relocate_Node
(Expression
(M
)));
2299 Set_From_At_Mod
(AtM_Nod
);
2300 Insert_After
(N
, AtM_Nod
);
2301 Mod_Val
:= Get_Alignment_Value
(Expression
(AtM_Nod
));
2302 Set_Mod_Clause
(N
, Empty
);
2305 -- Get the alignment value to perform error checking
2307 Mod_Val
:= Get_Alignment_Value
(Expression
(M
));
2313 -- For untagged types, clear any existing component clauses for the
2314 -- type. If the type is derived, this is what allows us to override
2315 -- a rep clause for the parent. For type extensions, the representation
2316 -- of the inherited components is inherited, so we want to keep previous
2317 -- component clauses for completeness.
2319 if not Is_Tagged_Type
(Rectype
) then
2320 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2321 while Present
(Comp
) loop
2322 Set_Component_Clause
(Comp
, Empty
);
2323 Next_Component_Or_Discriminant
(Comp
);
2327 -- All done if no component clauses
2329 CC
:= First
(Component_Clauses
(N
));
2335 -- If a tag is present, then create a component clause that places it
2336 -- at the start of the record (otherwise gigi may place it after other
2337 -- fields that have rep clauses).
2339 Fent
:= First_Entity
(Rectype
);
2341 if Nkind
(Fent
) = N_Defining_Identifier
2342 and then Chars
(Fent
) = Name_uTag
2344 Set_Component_Bit_Offset
(Fent
, Uint_0
);
2345 Set_Normalized_Position
(Fent
, Uint_0
);
2346 Set_Normalized_First_Bit
(Fent
, Uint_0
);
2347 Set_Normalized_Position_Max
(Fent
, Uint_0
);
2348 Init_Esize
(Fent
, System_Address_Size
);
2350 Set_Component_Clause
(Fent
,
2351 Make_Component_Clause
(Loc
,
2353 Make_Identifier
(Loc
,
2354 Chars
=> Name_uTag
),
2357 Make_Integer_Literal
(Loc
,
2361 Make_Integer_Literal
(Loc
,
2365 Make_Integer_Literal
(Loc
,
2366 UI_From_Int
(System_Address_Size
))));
2368 Ccount
:= Ccount
+ 1;
2371 -- A representation like this applies to the base type
2373 Set_Has_Record_Rep_Clause
(Base_Type
(Rectype
));
2374 Set_Has_Non_Standard_Rep
(Base_Type
(Rectype
));
2375 Set_Has_Specified_Layout
(Base_Type
(Rectype
));
2377 Max_Bit_So_Far
:= Uint_Minus_1
;
2378 Overlap_Check_Required
:= False;
2380 -- Process the component clauses
2382 while Present
(CC
) loop
2386 if Nkind
(CC
) = N_Pragma
then
2389 -- The only pragma of interest is Complete_Representation
2391 if Pragma_Name
(CC
) = Name_Complete_Representation
then
2395 -- Processing for real component clause
2398 Ccount
:= Ccount
+ 1;
2399 Posit
:= Static_Integer
(Position
(CC
));
2400 Fbit
:= Static_Integer
(First_Bit
(CC
));
2401 Lbit
:= Static_Integer
(Last_Bit
(CC
));
2404 and then Fbit
/= No_Uint
2405 and then Lbit
/= No_Uint
2409 ("position cannot be negative", Position
(CC
));
2413 ("first bit cannot be negative", First_Bit
(CC
));
2415 -- The Last_Bit specified in a component clause must not be
2416 -- less than the First_Bit minus one (RM-13.5.1(10)).
2418 elsif Lbit
< Fbit
- 1 then
2420 ("last bit cannot be less than first bit minus one",
2423 -- Values look OK, so find the corresponding record component
2424 -- Even though the syntax allows an attribute reference for
2425 -- implementation-defined components, GNAT does not allow the
2426 -- tag to get an explicit position.
2428 elsif Nkind
(Component_Name
(CC
)) = N_Attribute_Reference
then
2429 if Attribute_Name
(Component_Name
(CC
)) = Name_Tag
then
2430 Error_Msg_N
("position of tag cannot be specified", CC
);
2432 Error_Msg_N
("illegal component name", CC
);
2436 Comp
:= First_Entity
(Rectype
);
2437 while Present
(Comp
) loop
2438 exit when Chars
(Comp
) = Chars
(Component_Name
(CC
));
2444 -- Maybe component of base type that is absent from
2445 -- statically constrained first subtype.
2447 Comp
:= First_Entity
(Base_Type
(Rectype
));
2448 while Present
(Comp
) loop
2449 exit when Chars
(Comp
) = Chars
(Component_Name
(CC
));
2456 ("component clause is for non-existent field", CC
);
2458 elsif Present
(Component_Clause
(Comp
)) then
2460 -- Diagnose duplicate rep clause, or check consistency
2461 -- if this is an inherited component. In a double fault,
2462 -- there may be a duplicate inconsistent clause for an
2463 -- inherited component.
2465 if Scope
(Original_Record_Component
(Comp
)) = Rectype
2466 or else Parent
(Component_Clause
(Comp
)) = N
2468 Error_Msg_Sloc
:= Sloc
(Component_Clause
(Comp
));
2469 Error_Msg_N
("component clause previously given#", CC
);
2473 Rep1
: constant Node_Id
:= Component_Clause
(Comp
);
2475 if Intval
(Position
(Rep1
)) /=
2476 Intval
(Position
(CC
))
2477 or else Intval
(First_Bit
(Rep1
)) /=
2478 Intval
(First_Bit
(CC
))
2479 or else Intval
(Last_Bit
(Rep1
)) /=
2480 Intval
(Last_Bit
(CC
))
2482 Error_Msg_N
("component clause inconsistent "
2483 & "with representation of ancestor", CC
);
2484 elsif Warn_On_Redundant_Constructs
then
2485 Error_Msg_N
("?redundant component clause "
2486 & "for inherited component!", CC
);
2492 -- Make reference for field in record rep clause and set
2493 -- appropriate entity field in the field identifier.
2496 (Comp
, Component_Name
(CC
), Set_Ref
=> False);
2497 Set_Entity
(Component_Name
(CC
), Comp
);
2499 -- Update Fbit and Lbit to the actual bit number
2501 Fbit
:= Fbit
+ UI_From_Int
(SSU
) * Posit
;
2502 Lbit
:= Lbit
+ UI_From_Int
(SSU
) * Posit
;
2504 if Fbit
<= Max_Bit_So_Far
then
2505 Overlap_Check_Required
:= True;
2507 Max_Bit_So_Far
:= Lbit
;
2510 if Has_Size_Clause
(Rectype
)
2511 and then Esize
(Rectype
) <= Lbit
2514 ("bit number out of range of specified size",
2517 Set_Component_Clause
(Comp
, CC
);
2518 Set_Component_Bit_Offset
(Comp
, Fbit
);
2519 Set_Esize
(Comp
, 1 + (Lbit
- Fbit
));
2520 Set_Normalized_First_Bit
(Comp
, Fbit
mod SSU
);
2521 Set_Normalized_Position
(Comp
, Fbit
/ SSU
);
2523 Set_Normalized_Position_Max
2524 (Fent
, Normalized_Position
(Fent
));
2526 if Is_Tagged_Type
(Rectype
)
2527 and then Fbit
< System_Address_Size
2530 ("component overlaps tag field of&",
2534 -- This information is also set in the corresponding
2535 -- component of the base type, found by accessing the
2536 -- Original_Record_Component link if it is present.
2538 Ocomp
:= Original_Record_Component
(Comp
);
2545 (Component_Name
(CC
),
2550 Set_Has_Biased_Representation
(Comp
, Biased
);
2552 if Biased
and Warn_On_Biased_Representation
then
2554 ("?component clause forces biased "
2555 & "representation", CC
);
2558 if Present
(Ocomp
) then
2559 Set_Component_Clause
(Ocomp
, CC
);
2560 Set_Component_Bit_Offset
(Ocomp
, Fbit
);
2561 Set_Normalized_First_Bit
(Ocomp
, Fbit
mod SSU
);
2562 Set_Normalized_Position
(Ocomp
, Fbit
/ SSU
);
2563 Set_Esize
(Ocomp
, 1 + (Lbit
- Fbit
));
2565 Set_Normalized_Position_Max
2566 (Ocomp
, Normalized_Position
(Ocomp
));
2568 Set_Has_Biased_Representation
2569 (Ocomp
, Has_Biased_Representation
(Comp
));
2572 if Esize
(Comp
) < 0 then
2573 Error_Msg_N
("component size is negative", CC
);
2584 -- Now that we have processed all the component clauses, check for
2585 -- overlap. We have to leave this till last, since the components can
2586 -- appear in any arbitrary order in the representation clause.
2588 -- We do not need this check if all specified ranges were monotonic,
2589 -- as recorded by Overlap_Check_Required being False at this stage.
2591 -- This first section checks if there are any overlapping entries at
2592 -- all. It does this by sorting all entries and then seeing if there are
2593 -- any overlaps. If there are none, then that is decisive, but if there
2594 -- are overlaps, they may still be OK (they may result from fields in
2595 -- different variants).
2597 if Overlap_Check_Required
then
2598 Overlap_Check1
: declare
2600 OC_Fbit
: array (0 .. Ccount
) of Uint
;
2601 -- First-bit values for component clauses, the value is the offset
2602 -- of the first bit of the field from start of record. The zero
2603 -- entry is for use in sorting.
2605 OC_Lbit
: array (0 .. Ccount
) of Uint
;
2606 -- Last-bit values for component clauses, the value is the offset
2607 -- of the last bit of the field from start of record. The zero
2608 -- entry is for use in sorting.
2610 OC_Count
: Natural := 0;
2611 -- Count of entries in OC_Fbit and OC_Lbit
2613 function OC_Lt
(Op1
, Op2
: Natural) return Boolean;
2614 -- Compare routine for Sort
2616 procedure OC_Move
(From
: Natural; To
: Natural);
2617 -- Move routine for Sort
2619 package Sorting
is new GNAT
.Heap_Sort_G
(OC_Move
, OC_Lt
);
2621 function OC_Lt
(Op1
, Op2
: Natural) return Boolean is
2623 return OC_Fbit
(Op1
) < OC_Fbit
(Op2
);
2626 procedure OC_Move
(From
: Natural; To
: Natural) is
2628 OC_Fbit
(To
) := OC_Fbit
(From
);
2629 OC_Lbit
(To
) := OC_Lbit
(From
);
2633 CC
:= First
(Component_Clauses
(N
));
2634 while Present
(CC
) loop
2635 if Nkind
(CC
) /= N_Pragma
then
2636 Posit
:= Static_Integer
(Position
(CC
));
2637 Fbit
:= Static_Integer
(First_Bit
(CC
));
2638 Lbit
:= Static_Integer
(Last_Bit
(CC
));
2641 and then Fbit
/= No_Uint
2642 and then Lbit
/= No_Uint
2644 OC_Count
:= OC_Count
+ 1;
2645 Posit
:= Posit
* SSU
;
2646 OC_Fbit
(OC_Count
) := Fbit
+ Posit
;
2647 OC_Lbit
(OC_Count
) := Lbit
+ Posit
;
2654 Sorting
.Sort
(OC_Count
);
2656 Overlap_Check_Required
:= False;
2657 for J
in 1 .. OC_Count
- 1 loop
2658 if OC_Lbit
(J
) >= OC_Fbit
(J
+ 1) then
2659 Overlap_Check_Required
:= True;
2666 -- If Overlap_Check_Required is still True, then we have to do the full
2667 -- scale overlap check, since we have at least two fields that do
2668 -- overlap, and we need to know if that is OK since they are in
2669 -- different variant, or whether we have a definite problem.
2671 if Overlap_Check_Required
then
2672 Overlap_Check2
: declare
2673 C1_Ent
, C2_Ent
: Entity_Id
;
2674 -- Entities of components being checked for overlap
2677 -- Component_List node whose Component_Items are being checked
2680 -- Component declaration for component being checked
2683 C1_Ent
:= First_Entity
(Base_Type
(Rectype
));
2685 -- Loop through all components in record. For each component check
2686 -- for overlap with any of the preceding elements on the component
2687 -- list containing the component and also, if the component is in
2688 -- a variant, check against components outside the case structure.
2689 -- This latter test is repeated recursively up the variant tree.
2691 Main_Component_Loop
: while Present
(C1_Ent
) loop
2692 if Ekind
(C1_Ent
) /= E_Component
2693 and then Ekind
(C1_Ent
) /= E_Discriminant
2695 goto Continue_Main_Component_Loop
;
2698 -- Skip overlap check if entity has no declaration node. This
2699 -- happens with discriminants in constrained derived types.
2700 -- Probably we are missing some checks as a result, but that
2701 -- does not seem terribly serious ???
2703 if No
(Declaration_Node
(C1_Ent
)) then
2704 goto Continue_Main_Component_Loop
;
2707 Clist
:= Parent
(List_Containing
(Declaration_Node
(C1_Ent
)));
2709 -- Loop through component lists that need checking. Check the
2710 -- current component list and all lists in variants above us.
2712 Component_List_Loop
: loop
2714 -- If derived type definition, go to full declaration
2715 -- If at outer level, check discriminants if there are any.
2717 if Nkind
(Clist
) = N_Derived_Type_Definition
then
2718 Clist
:= Parent
(Clist
);
2721 -- Outer level of record definition, check discriminants
2723 if Nkind_In
(Clist
, N_Full_Type_Declaration
,
2724 N_Private_Type_Declaration
)
2726 if Has_Discriminants
(Defining_Identifier
(Clist
)) then
2728 First_Discriminant
(Defining_Identifier
(Clist
));
2730 while Present
(C2_Ent
) loop
2731 exit when C1_Ent
= C2_Ent
;
2732 Check_Component_Overlap
(C1_Ent
, C2_Ent
);
2733 Next_Discriminant
(C2_Ent
);
2737 -- Record extension case
2739 elsif Nkind
(Clist
) = N_Derived_Type_Definition
then
2742 -- Otherwise check one component list
2745 Citem
:= First
(Component_Items
(Clist
));
2747 while Present
(Citem
) loop
2748 if Nkind
(Citem
) = N_Component_Declaration
then
2749 C2_Ent
:= Defining_Identifier
(Citem
);
2750 exit when C1_Ent
= C2_Ent
;
2751 Check_Component_Overlap
(C1_Ent
, C2_Ent
);
2758 -- Check for variants above us (the parent of the Clist can
2759 -- be a variant, in which case its parent is a variant part,
2760 -- and the parent of the variant part is a component list
2761 -- whose components must all be checked against the current
2762 -- component for overlap).
2764 if Nkind
(Parent
(Clist
)) = N_Variant
then
2765 Clist
:= Parent
(Parent
(Parent
(Clist
)));
2767 -- Check for possible discriminant part in record, this is
2768 -- treated essentially as another level in the recursion.
2769 -- For this case the parent of the component list is the
2770 -- record definition, and its parent is the full type
2771 -- declaration containing the discriminant specifications.
2773 elsif Nkind
(Parent
(Clist
)) = N_Record_Definition
then
2774 Clist
:= Parent
(Parent
((Clist
)));
2776 -- If neither of these two cases, we are at the top of
2780 exit Component_List_Loop
;
2782 end loop Component_List_Loop
;
2784 <<Continue_Main_Component_Loop
>>
2785 Next_Entity
(C1_Ent
);
2787 end loop Main_Component_Loop
;
2791 -- For records that have component clauses for all components, and whose
2792 -- size is less than or equal to 32, we need to know the size in the
2793 -- front end to activate possible packed array processing where the
2794 -- component type is a record.
2796 -- At this stage Hbit + 1 represents the first unused bit from all the
2797 -- component clauses processed, so if the component clauses are
2798 -- complete, then this is the length of the record.
2800 -- For records longer than System.Storage_Unit, and for those where not
2801 -- all components have component clauses, the back end determines the
2802 -- length (it may for example be appropriate to round up the size
2803 -- to some convenient boundary, based on alignment considerations, etc).
2805 if Unknown_RM_Size
(Rectype
) and then Hbit
+ 1 <= 32 then
2807 -- Nothing to do if at least one component has no component clause
2809 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2810 while Present
(Comp
) loop
2811 exit when No
(Component_Clause
(Comp
));
2812 Next_Component_Or_Discriminant
(Comp
);
2815 -- If we fall out of loop, all components have component clauses
2816 -- and so we can set the size to the maximum value.
2819 Set_RM_Size
(Rectype
, Hbit
+ 1);
2823 -- Check missing components if Complete_Representation pragma appeared
2825 if Present
(CR_Pragma
) then
2826 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2827 while Present
(Comp
) loop
2828 if No
(Component_Clause
(Comp
)) then
2830 ("missing component clause for &", CR_Pragma
, Comp
);
2833 Next_Component_Or_Discriminant
(Comp
);
2836 -- If no Complete_Representation pragma, warn if missing components
2838 elsif Warn_On_Unrepped_Components
then
2840 Num_Repped_Components
: Nat
:= 0;
2841 Num_Unrepped_Components
: Nat
:= 0;
2844 -- First count number of repped and unrepped components
2846 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2847 while Present
(Comp
) loop
2848 if Present
(Component_Clause
(Comp
)) then
2849 Num_Repped_Components
:= Num_Repped_Components
+ 1;
2851 Num_Unrepped_Components
:= Num_Unrepped_Components
+ 1;
2854 Next_Component_Or_Discriminant
(Comp
);
2857 -- We are only interested in the case where there is at least one
2858 -- unrepped component, and at least half the components have rep
2859 -- clauses. We figure that if less than half have them, then the
2860 -- partial rep clause is really intentional. If the component
2861 -- type has no underlying type set at this point (as for a generic
2862 -- formal type), we don't know enough to give a warning on the
2865 if Num_Unrepped_Components
> 0
2866 and then Num_Unrepped_Components
< Num_Repped_Components
2868 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2869 while Present
(Comp
) loop
2870 if No
(Component_Clause
(Comp
))
2871 and then Comes_From_Source
(Comp
)
2872 and then Present
(Underlying_Type
(Etype
(Comp
)))
2873 and then (Is_Scalar_Type
(Underlying_Type
(Etype
(Comp
)))
2874 or else Size_Known_At_Compile_Time
2875 (Underlying_Type
(Etype
(Comp
))))
2876 and then not Has_Warnings_Off
(Rectype
)
2878 Error_Msg_Sloc
:= Sloc
(Comp
);
2880 ("?no component clause given for & declared #",
2884 Next_Component_Or_Discriminant
(Comp
);
2889 end Analyze_Record_Representation_Clause
;
2891 -----------------------------
2892 -- Check_Component_Overlap --
2893 -----------------------------
2895 procedure Check_Component_Overlap
(C1_Ent
, C2_Ent
: Entity_Id
) is
2897 if Present
(Component_Clause
(C1_Ent
))
2898 and then Present
(Component_Clause
(C2_Ent
))
2900 -- Exclude odd case where we have two tag fields in the same record,
2901 -- both at location zero. This seems a bit strange, but it seems to
2902 -- happen in some circumstances ???
2904 if Chars
(C1_Ent
) = Name_uTag
2905 and then Chars
(C2_Ent
) = Name_uTag
2910 -- Here we check if the two fields overlap
2913 S1
: constant Uint
:= Component_Bit_Offset
(C1_Ent
);
2914 S2
: constant Uint
:= Component_Bit_Offset
(C2_Ent
);
2915 E1
: constant Uint
:= S1
+ Esize
(C1_Ent
);
2916 E2
: constant Uint
:= S2
+ Esize
(C2_Ent
);
2919 if E2
<= S1
or else E1
<= S2
then
2923 Component_Name
(Component_Clause
(C2_Ent
));
2924 Error_Msg_Sloc
:= Sloc
(Error_Msg_Node_2
);
2926 Component_Name
(Component_Clause
(C1_Ent
));
2928 ("component& overlaps & #",
2929 Component_Name
(Component_Clause
(C1_Ent
)));
2933 end Check_Component_Overlap
;
2935 -----------------------------------
2936 -- Check_Constant_Address_Clause --
2937 -----------------------------------
2939 procedure Check_Constant_Address_Clause
2943 procedure Check_At_Constant_Address
(Nod
: Node_Id
);
2944 -- Checks that the given node N represents a name whose 'Address is
2945 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2946 -- address value is the same at the point of declaration of U_Ent and at
2947 -- the time of elaboration of the address clause.
2949 procedure Check_Expr_Constants
(Nod
: Node_Id
);
2950 -- Checks that Nod meets the requirements for a constant address clause
2951 -- in the sense of the enclosing procedure.
2953 procedure Check_List_Constants
(Lst
: List_Id
);
2954 -- Check that all elements of list Lst meet the requirements for a
2955 -- constant address clause in the sense of the enclosing procedure.
2957 -------------------------------
2958 -- Check_At_Constant_Address --
2959 -------------------------------
2961 procedure Check_At_Constant_Address
(Nod
: Node_Id
) is
2963 if Is_Entity_Name
(Nod
) then
2964 if Present
(Address_Clause
(Entity
((Nod
)))) then
2966 ("invalid address clause for initialized object &!",
2969 ("address for& cannot" &
2970 " depend on another address clause! (RM 13.1(22))!",
2973 elsif In_Same_Source_Unit
(Entity
(Nod
), U_Ent
)
2974 and then Sloc
(U_Ent
) < Sloc
(Entity
(Nod
))
2977 ("invalid address clause for initialized object &!",
2979 Error_Msg_Name_1
:= Chars
(Entity
(Nod
));
2980 Error_Msg_Name_2
:= Chars
(U_Ent
);
2982 ("\% must be defined before % (RM 13.1(22))!",
2986 elsif Nkind
(Nod
) = N_Selected_Component
then
2988 T
: constant Entity_Id
:= Etype
(Prefix
(Nod
));
2991 if (Is_Record_Type
(T
)
2992 and then Has_Discriminants
(T
))
2995 and then Is_Record_Type
(Designated_Type
(T
))
2996 and then Has_Discriminants
(Designated_Type
(T
)))
2999 ("invalid address clause for initialized object &!",
3002 ("\address cannot depend on component" &
3003 " of discriminated record (RM 13.1(22))!",
3006 Check_At_Constant_Address
(Prefix
(Nod
));
3010 elsif Nkind
(Nod
) = N_Indexed_Component
then
3011 Check_At_Constant_Address
(Prefix
(Nod
));
3012 Check_List_Constants
(Expressions
(Nod
));
3015 Check_Expr_Constants
(Nod
);
3017 end Check_At_Constant_Address
;
3019 --------------------------
3020 -- Check_Expr_Constants --
3021 --------------------------
3023 procedure Check_Expr_Constants
(Nod
: Node_Id
) is
3024 Loc_U_Ent
: constant Source_Ptr
:= Sloc
(U_Ent
);
3025 Ent
: Entity_Id
:= Empty
;
3028 if Nkind
(Nod
) in N_Has_Etype
3029 and then Etype
(Nod
) = Any_Type
3035 when N_Empty | N_Error
=>
3038 when N_Identifier | N_Expanded_Name
=>
3039 Ent
:= Entity
(Nod
);
3041 -- We need to look at the original node if it is different
3042 -- from the node, since we may have rewritten things and
3043 -- substituted an identifier representing the rewrite.
3045 if Original_Node
(Nod
) /= Nod
then
3046 Check_Expr_Constants
(Original_Node
(Nod
));
3048 -- If the node is an object declaration without initial
3049 -- value, some code has been expanded, and the expression
3050 -- is not constant, even if the constituents might be
3051 -- acceptable, as in A'Address + offset.
3053 if Ekind
(Ent
) = E_Variable
3055 Nkind
(Declaration_Node
(Ent
)) = N_Object_Declaration
3057 No
(Expression
(Declaration_Node
(Ent
)))
3060 ("invalid address clause for initialized object &!",
3063 -- If entity is constant, it may be the result of expanding
3064 -- a check. We must verify that its declaration appears
3065 -- before the object in question, else we also reject the
3068 elsif Ekind
(Ent
) = E_Constant
3069 and then In_Same_Source_Unit
(Ent
, U_Ent
)
3070 and then Sloc
(Ent
) > Loc_U_Ent
3073 ("invalid address clause for initialized object &!",
3080 -- Otherwise look at the identifier and see if it is OK
3082 if Ekind
(Ent
) = E_Named_Integer
3084 Ekind
(Ent
) = E_Named_Real
3091 Ekind
(Ent
) = E_Constant
3093 Ekind
(Ent
) = E_In_Parameter
3095 -- This is the case where we must have Ent defined before
3096 -- U_Ent. Clearly if they are in different units this
3097 -- requirement is met since the unit containing Ent is
3098 -- already processed.
3100 if not In_Same_Source_Unit
(Ent
, U_Ent
) then
3103 -- Otherwise location of Ent must be before the location
3104 -- of U_Ent, that's what prior defined means.
3106 elsif Sloc
(Ent
) < Loc_U_Ent
then
3111 ("invalid address clause for initialized object &!",
3113 Error_Msg_Name_1
:= Chars
(Ent
);
3114 Error_Msg_Name_2
:= Chars
(U_Ent
);
3116 ("\% must be defined before % (RM 13.1(22))!",
3120 elsif Nkind
(Original_Node
(Nod
)) = N_Function_Call
then
3121 Check_Expr_Constants
(Original_Node
(Nod
));
3125 ("invalid address clause for initialized object &!",
3128 if Comes_From_Source
(Ent
) then
3129 Error_Msg_Name_1
:= Chars
(Ent
);
3131 ("\reference to variable% not allowed"
3132 & " (RM 13.1(22))!", Nod
);
3135 ("non-static expression not allowed"
3136 & " (RM 13.1(22))!", Nod
);
3140 when N_Integer_Literal
=>
3142 -- If this is a rewritten unchecked conversion, in a system
3143 -- where Address is an integer type, always use the base type
3144 -- for a literal value. This is user-friendly and prevents
3145 -- order-of-elaboration issues with instances of unchecked
3148 if Nkind
(Original_Node
(Nod
)) = N_Function_Call
then
3149 Set_Etype
(Nod
, Base_Type
(Etype
(Nod
)));
3152 when N_Real_Literal |
3154 N_Character_Literal
=>
3158 Check_Expr_Constants
(Low_Bound
(Nod
));
3159 Check_Expr_Constants
(High_Bound
(Nod
));
3161 when N_Explicit_Dereference
=>
3162 Check_Expr_Constants
(Prefix
(Nod
));
3164 when N_Indexed_Component
=>
3165 Check_Expr_Constants
(Prefix
(Nod
));
3166 Check_List_Constants
(Expressions
(Nod
));
3169 Check_Expr_Constants
(Prefix
(Nod
));
3170 Check_Expr_Constants
(Discrete_Range
(Nod
));
3172 when N_Selected_Component
=>
3173 Check_Expr_Constants
(Prefix
(Nod
));
3175 when N_Attribute_Reference
=>
3176 if Attribute_Name
(Nod
) = Name_Address
3178 Attribute_Name
(Nod
) = Name_Access
3180 Attribute_Name
(Nod
) = Name_Unchecked_Access
3182 Attribute_Name
(Nod
) = Name_Unrestricted_Access
3184 Check_At_Constant_Address
(Prefix
(Nod
));
3187 Check_Expr_Constants
(Prefix
(Nod
));
3188 Check_List_Constants
(Expressions
(Nod
));
3192 Check_List_Constants
(Component_Associations
(Nod
));
3193 Check_List_Constants
(Expressions
(Nod
));
3195 when N_Component_Association
=>
3196 Check_Expr_Constants
(Expression
(Nod
));
3198 when N_Extension_Aggregate
=>
3199 Check_Expr_Constants
(Ancestor_Part
(Nod
));
3200 Check_List_Constants
(Component_Associations
(Nod
));
3201 Check_List_Constants
(Expressions
(Nod
));
3206 when N_Binary_Op | N_And_Then | N_Or_Else | N_Membership_Test
=>
3207 Check_Expr_Constants
(Left_Opnd
(Nod
));
3208 Check_Expr_Constants
(Right_Opnd
(Nod
));
3211 Check_Expr_Constants
(Right_Opnd
(Nod
));
3213 when N_Type_Conversion |
3214 N_Qualified_Expression |
3216 Check_Expr_Constants
(Expression
(Nod
));
3218 when N_Unchecked_Type_Conversion
=>
3219 Check_Expr_Constants
(Expression
(Nod
));
3221 -- If this is a rewritten unchecked conversion, subtypes in
3222 -- this node are those created within the instance. To avoid
3223 -- order of elaboration issues, replace them with their base
3224 -- types. Note that address clauses can cause order of
3225 -- elaboration problems because they are elaborated by the
3226 -- back-end at the point of definition, and may mention
3227 -- entities declared in between (as long as everything is
3228 -- static). It is user-friendly to allow unchecked conversions
3231 if Nkind
(Original_Node
(Nod
)) = N_Function_Call
then
3232 Set_Etype
(Expression
(Nod
),
3233 Base_Type
(Etype
(Expression
(Nod
))));
3234 Set_Etype
(Nod
, Base_Type
(Etype
(Nod
)));
3237 when N_Function_Call
=>
3238 if not Is_Pure
(Entity
(Name
(Nod
))) then
3240 ("invalid address clause for initialized object &!",
3244 ("\function & is not pure (RM 13.1(22))!",
3245 Nod
, Entity
(Name
(Nod
)));
3248 Check_List_Constants
(Parameter_Associations
(Nod
));
3251 when N_Parameter_Association
=>
3252 Check_Expr_Constants
(Explicit_Actual_Parameter
(Nod
));
3256 ("invalid address clause for initialized object &!",
3259 ("\must be constant defined before& (RM 13.1(22))!",
3262 end Check_Expr_Constants
;
3264 --------------------------
3265 -- Check_List_Constants --
3266 --------------------------
3268 procedure Check_List_Constants
(Lst
: List_Id
) is
3272 if Present
(Lst
) then
3273 Nod1
:= First
(Lst
);
3274 while Present
(Nod1
) loop
3275 Check_Expr_Constants
(Nod1
);
3279 end Check_List_Constants
;
3281 -- Start of processing for Check_Constant_Address_Clause
3284 Check_Expr_Constants
(Expr
);
3285 end Check_Constant_Address_Clause
;
3291 procedure Check_Size
3295 Biased
: out Boolean)
3297 UT
: constant Entity_Id
:= Underlying_Type
(T
);
3303 -- Dismiss cases for generic types or types with previous errors
3306 or else UT
= Any_Type
3307 or else Is_Generic_Type
(UT
)
3308 or else Is_Generic_Type
(Root_Type
(UT
))
3312 -- Check case of bit packed array
3314 elsif Is_Array_Type
(UT
)
3315 and then Known_Static_Component_Size
(UT
)
3316 and then Is_Bit_Packed_Array
(UT
)
3324 Asiz
:= Component_Size
(UT
);
3325 Indx
:= First_Index
(UT
);
3327 Ityp
:= Etype
(Indx
);
3329 -- If non-static bound, then we are not in the business of
3330 -- trying to check the length, and indeed an error will be
3331 -- issued elsewhere, since sizes of non-static array types
3332 -- cannot be set implicitly or explicitly.
3334 if not Is_Static_Subtype
(Ityp
) then
3338 -- Otherwise accumulate next dimension
3340 Asiz
:= Asiz
* (Expr_Value
(Type_High_Bound
(Ityp
)) -
3341 Expr_Value
(Type_Low_Bound
(Ityp
)) +
3345 exit when No
(Indx
);
3351 Error_Msg_Uint_1
:= Asiz
;
3353 ("size for& too small, minimum allowed is ^", N
, T
);
3354 Set_Esize
(T
, Asiz
);
3355 Set_RM_Size
(T
, Asiz
);
3359 -- All other composite types are ignored
3361 elsif Is_Composite_Type
(UT
) then
3364 -- For fixed-point types, don't check minimum if type is not frozen,
3365 -- since we don't know all the characteristics of the type that can
3366 -- affect the size (e.g. a specified small) till freeze time.
3368 elsif Is_Fixed_Point_Type
(UT
)
3369 and then not Is_Frozen
(UT
)
3373 -- Cases for which a minimum check is required
3376 -- Ignore if specified size is correct for the type
3378 if Known_Esize
(UT
) and then Siz
= Esize
(UT
) then
3382 -- Otherwise get minimum size
3384 M
:= UI_From_Int
(Minimum_Size
(UT
));
3388 -- Size is less than minimum size, but one possibility remains
3389 -- that we can manage with the new size if we bias the type.
3391 M
:= UI_From_Int
(Minimum_Size
(UT
, Biased
=> True));
3394 Error_Msg_Uint_1
:= M
;
3396 ("size for& too small, minimum allowed is ^", N
, T
);
3406 -------------------------
3407 -- Get_Alignment_Value --
3408 -------------------------
3410 function Get_Alignment_Value
(Expr
: Node_Id
) return Uint
is
3411 Align
: constant Uint
:= Static_Integer
(Expr
);
3414 if Align
= No_Uint
then
3417 elsif Align
<= 0 then
3418 Error_Msg_N
("alignment value must be positive", Expr
);
3422 for J
in Int
range 0 .. 64 loop
3424 M
: constant Uint
:= Uint_2
** J
;
3427 exit when M
= Align
;
3431 ("alignment value must be power of 2", Expr
);
3439 end Get_Alignment_Value
;
3445 procedure Initialize
is
3447 Unchecked_Conversions
.Init
;
3450 -------------------------
3451 -- Is_Operational_Item --
3452 -------------------------
3454 function Is_Operational_Item
(N
: Node_Id
) return Boolean is
3456 if Nkind
(N
) /= N_Attribute_Definition_Clause
then
3460 Id
: constant Attribute_Id
:= Get_Attribute_Id
(Chars
(N
));
3462 return Id
= Attribute_Input
3463 or else Id
= Attribute_Output
3464 or else Id
= Attribute_Read
3465 or else Id
= Attribute_Write
3466 or else Id
= Attribute_External_Tag
;
3469 end Is_Operational_Item
;
3475 function Minimum_Size
3477 Biased
: Boolean := False) return Nat
3479 Lo
: Uint
:= No_Uint
;
3480 Hi
: Uint
:= No_Uint
;
3481 LoR
: Ureal
:= No_Ureal
;
3482 HiR
: Ureal
:= No_Ureal
;
3483 LoSet
: Boolean := False;
3484 HiSet
: Boolean := False;
3488 R_Typ
: constant Entity_Id
:= Root_Type
(T
);
3491 -- If bad type, return 0
3493 if T
= Any_Type
then
3496 -- For generic types, just return zero. There cannot be any legitimate
3497 -- need to know such a size, but this routine may be called with a
3498 -- generic type as part of normal processing.
3500 elsif Is_Generic_Type
(R_Typ
)
3501 or else R_Typ
= Any_Type
3505 -- Access types. Normally an access type cannot have a size smaller
3506 -- than the size of System.Address. The exception is on VMS, where
3507 -- we have short and long addresses, and it is possible for an access
3508 -- type to have a short address size (and thus be less than the size
3509 -- of System.Address itself). We simply skip the check for VMS, and
3510 -- leave it to the back end to do the check.
3512 elsif Is_Access_Type
(T
) then
3513 if OpenVMS_On_Target
then
3516 return System_Address_Size
;
3519 -- Floating-point types
3521 elsif Is_Floating_Point_Type
(T
) then
3522 return UI_To_Int
(Esize
(R_Typ
));
3526 elsif Is_Discrete_Type
(T
) then
3528 -- The following loop is looking for the nearest compile time known
3529 -- bounds following the ancestor subtype chain. The idea is to find
3530 -- the most restrictive known bounds information.
3534 if Ancest
= Any_Type
or else Etype
(Ancest
) = Any_Type
then
3539 if Compile_Time_Known_Value
(Type_Low_Bound
(Ancest
)) then
3540 Lo
:= Expr_Rep_Value
(Type_Low_Bound
(Ancest
));
3547 if Compile_Time_Known_Value
(Type_High_Bound
(Ancest
)) then
3548 Hi
:= Expr_Rep_Value
(Type_High_Bound
(Ancest
));
3554 Ancest
:= Ancestor_Subtype
(Ancest
);
3557 Ancest
:= Base_Type
(T
);
3559 if Is_Generic_Type
(Ancest
) then
3565 -- Fixed-point types. We can't simply use Expr_Value to get the
3566 -- Corresponding_Integer_Value values of the bounds, since these do not
3567 -- get set till the type is frozen, and this routine can be called
3568 -- before the type is frozen. Similarly the test for bounds being static
3569 -- needs to include the case where we have unanalyzed real literals for
3572 elsif Is_Fixed_Point_Type
(T
) then
3574 -- The following loop is looking for the nearest compile time known
3575 -- bounds following the ancestor subtype chain. The idea is to find
3576 -- the most restrictive known bounds information.
3580 if Ancest
= Any_Type
or else Etype
(Ancest
) = Any_Type
then
3584 -- Note: In the following two tests for LoSet and HiSet, it may
3585 -- seem redundant to test for N_Real_Literal here since normally
3586 -- one would assume that the test for the value being known at
3587 -- compile time includes this case. However, there is a glitch.
3588 -- If the real literal comes from folding a non-static expression,
3589 -- then we don't consider any non- static expression to be known
3590 -- at compile time if we are in configurable run time mode (needed
3591 -- in some cases to give a clearer definition of what is and what
3592 -- is not accepted). So the test is indeed needed. Without it, we
3593 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
3596 if Nkind
(Type_Low_Bound
(Ancest
)) = N_Real_Literal
3597 or else Compile_Time_Known_Value
(Type_Low_Bound
(Ancest
))
3599 LoR
:= Expr_Value_R
(Type_Low_Bound
(Ancest
));
3606 if Nkind
(Type_High_Bound
(Ancest
)) = N_Real_Literal
3607 or else Compile_Time_Known_Value
(Type_High_Bound
(Ancest
))
3609 HiR
:= Expr_Value_R
(Type_High_Bound
(Ancest
));
3615 Ancest
:= Ancestor_Subtype
(Ancest
);
3618 Ancest
:= Base_Type
(T
);
3620 if Is_Generic_Type
(Ancest
) then
3626 Lo
:= UR_To_Uint
(LoR
/ Small_Value
(T
));
3627 Hi
:= UR_To_Uint
(HiR
/ Small_Value
(T
));
3629 -- No other types allowed
3632 raise Program_Error
;
3635 -- Fall through with Hi and Lo set. Deal with biased case
3638 and then not Is_Fixed_Point_Type
(T
)
3639 and then not (Is_Enumeration_Type
(T
)
3640 and then Has_Non_Standard_Rep
(T
)))
3641 or else Has_Biased_Representation
(T
)
3647 -- Signed case. Note that we consider types like range 1 .. -1 to be
3648 -- signed for the purpose of computing the size, since the bounds have
3649 -- to be accommodated in the base type.
3651 if Lo
< 0 or else Hi
< 0 then
3655 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
3656 -- Note that we accommodate the case where the bounds cross. This
3657 -- can happen either because of the way the bounds are declared
3658 -- or because of the algorithm in Freeze_Fixed_Point_Type.
3672 -- If both bounds are positive, make sure that both are represen-
3673 -- table in the case where the bounds are crossed. This can happen
3674 -- either because of the way the bounds are declared, or because of
3675 -- the algorithm in Freeze_Fixed_Point_Type.
3681 -- S = size, (can accommodate 0 .. (2**size - 1))
3684 while Hi
>= Uint_2
** S
loop
3692 ---------------------------
3693 -- New_Stream_Subprogram --
3694 ---------------------------
3696 procedure New_Stream_Subprogram
3700 Nam
: TSS_Name_Type
)
3702 Loc
: constant Source_Ptr
:= Sloc
(N
);
3703 Sname
: constant Name_Id
:= Make_TSS_Name
(Base_Type
(Ent
), Nam
);
3704 Subp_Id
: Entity_Id
;
3705 Subp_Decl
: Node_Id
;
3709 Defer_Declaration
: constant Boolean :=
3710 Is_Tagged_Type
(Ent
) or else Is_Private_Type
(Ent
);
3711 -- For a tagged type, there is a declaration for each stream attribute
3712 -- at the freeze point, and we must generate only a completion of this
3713 -- declaration. We do the same for private types, because the full view
3714 -- might be tagged. Otherwise we generate a declaration at the point of
3715 -- the attribute definition clause.
3717 function Build_Spec
return Node_Id
;
3718 -- Used for declaration and renaming declaration, so that this is
3719 -- treated as a renaming_as_body.
3725 function Build_Spec
return Node_Id
is
3726 Out_P
: constant Boolean := (Nam
= TSS_Stream_Read
);
3729 T_Ref
: constant Node_Id
:= New_Reference_To
(Etyp
, Loc
);
3732 Subp_Id
:= Make_Defining_Identifier
(Loc
, Sname
);
3734 -- S : access Root_Stream_Type'Class
3736 Formals
:= New_List
(
3737 Make_Parameter_Specification
(Loc
,
3738 Defining_Identifier
=>
3739 Make_Defining_Identifier
(Loc
, Name_S
),
3741 Make_Access_Definition
(Loc
,
3744 Designated_Type
(Etype
(F
)), Loc
))));
3746 if Nam
= TSS_Stream_Input
then
3747 Spec
:= Make_Function_Specification
(Loc
,
3748 Defining_Unit_Name
=> Subp_Id
,
3749 Parameter_Specifications
=> Formals
,
3750 Result_Definition
=> T_Ref
);
3755 Make_Parameter_Specification
(Loc
,
3756 Defining_Identifier
=> Make_Defining_Identifier
(Loc
, Name_V
),
3757 Out_Present
=> Out_P
,
3758 Parameter_Type
=> T_Ref
));
3760 Spec
:= Make_Procedure_Specification
(Loc
,
3761 Defining_Unit_Name
=> Subp_Id
,
3762 Parameter_Specifications
=> Formals
);
3768 -- Start of processing for New_Stream_Subprogram
3771 F
:= First_Formal
(Subp
);
3773 if Ekind
(Subp
) = E_Procedure
then
3774 Etyp
:= Etype
(Next_Formal
(F
));
3776 Etyp
:= Etype
(Subp
);
3779 -- Prepare subprogram declaration and insert it as an action on the
3780 -- clause node. The visibility for this entity is used to test for
3781 -- visibility of the attribute definition clause (in the sense of
3782 -- 8.3(23) as amended by AI-195).
3784 if not Defer_Declaration
then
3786 Make_Subprogram_Declaration
(Loc
,
3787 Specification
=> Build_Spec
);
3789 -- For a tagged type, there is always a visible declaration for each
3790 -- stream TSS (it is a predefined primitive operation), and the
3791 -- completion of this declaration occurs at the freeze point, which is
3792 -- not always visible at places where the attribute definition clause is
3793 -- visible. So, we create a dummy entity here for the purpose of
3794 -- tracking the visibility of the attribute definition clause itself.
3798 Make_Defining_Identifier
(Loc
,
3799 Chars
=> New_External_Name
(Sname
, 'V'));
3801 Make_Object_Declaration
(Loc
,
3802 Defining_Identifier
=> Subp_Id
,
3803 Object_Definition
=> New_Occurrence_Of
(Standard_Boolean
, Loc
));
3806 Insert_Action
(N
, Subp_Decl
);
3807 Set_Entity
(N
, Subp_Id
);
3810 Make_Subprogram_Renaming_Declaration
(Loc
,
3811 Specification
=> Build_Spec
,
3812 Name
=> New_Reference_To
(Subp
, Loc
));
3814 if Defer_Declaration
then
3815 Set_TSS
(Base_Type
(Ent
), Subp_Id
);
3817 Insert_Action
(N
, Subp_Decl
);
3818 Copy_TSS
(Subp_Id
, Base_Type
(Ent
));
3820 end New_Stream_Subprogram
;
3822 ------------------------
3823 -- Rep_Item_Too_Early --
3824 ------------------------
3826 function Rep_Item_Too_Early
(T
: Entity_Id
; N
: Node_Id
) return Boolean is
3828 -- Cannot apply non-operational rep items to generic types
3830 if Is_Operational_Item
(N
) then
3834 and then Is_Generic_Type
(Root_Type
(T
))
3837 ("representation item not allowed for generic type", N
);
3841 -- Otherwise check for incomplete type
3843 if Is_Incomplete_Or_Private_Type
(T
)
3844 and then No
(Underlying_Type
(T
))
3847 ("representation item must be after full type declaration", N
);
3850 -- If the type has incomplete components, a representation clause is
3851 -- illegal but stream attributes and Convention pragmas are correct.
3853 elsif Has_Private_Component
(T
) then
3854 if Nkind
(N
) = N_Pragma
then
3858 ("representation item must appear after type is fully defined",
3865 end Rep_Item_Too_Early
;
3867 -----------------------
3868 -- Rep_Item_Too_Late --
3869 -----------------------
3871 function Rep_Item_Too_Late
3874 FOnly
: Boolean := False) return Boolean
3877 Parent_Type
: Entity_Id
;
3880 -- Output the too late message. Note that this is not considered a
3881 -- serious error, since the effect is simply that we ignore the
3882 -- representation clause in this case.
3888 procedure Too_Late
is
3890 Error_Msg_N
("|representation item appears too late!", N
);
3893 -- Start of processing for Rep_Item_Too_Late
3896 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
3897 -- types, which may be frozen if they appear in a representation clause
3898 -- for a local type.
3901 and then not From_With_Type
(T
)
3904 S
:= First_Subtype
(T
);
3906 if Present
(Freeze_Node
(S
)) then
3908 ("?no more representation items for }", Freeze_Node
(S
), S
);
3913 -- Check for case of non-tagged derived type whose parent either has
3914 -- primitive operations, or is a by reference type (RM 13.1(10)).
3918 and then Is_Derived_Type
(T
)
3919 and then not Is_Tagged_Type
(T
)
3921 Parent_Type
:= Etype
(Base_Type
(T
));
3923 if Has_Primitive_Operations
(Parent_Type
) then
3926 ("primitive operations already defined for&!", N
, Parent_Type
);
3929 elsif Is_By_Reference_Type
(Parent_Type
) then
3932 ("parent type & is a by reference type!", N
, Parent_Type
);
3937 -- No error, link item into head of chain of rep items for the entity,
3938 -- but avoid chaining if we have an overloadable entity, and the pragma
3939 -- is one that can apply to multiple overloaded entities.
3941 if Is_Overloadable
(T
)
3942 and then Nkind
(N
) = N_Pragma
3945 Pname
: constant Name_Id
:= Pragma_Name
(N
);
3947 if Pname
= Name_Convention
or else
3948 Pname
= Name_Import
or else
3949 Pname
= Name_Export
or else
3950 Pname
= Name_External
or else
3951 Pname
= Name_Interface
3958 Record_Rep_Item
(T
, N
);
3960 end Rep_Item_Too_Late
;
3962 -------------------------
3963 -- Same_Representation --
3964 -------------------------
3966 function Same_Representation
(Typ1
, Typ2
: Entity_Id
) return Boolean is
3967 T1
: constant Entity_Id
:= Underlying_Type
(Typ1
);
3968 T2
: constant Entity_Id
:= Underlying_Type
(Typ2
);
3971 -- A quick check, if base types are the same, then we definitely have
3972 -- the same representation, because the subtype specific representation
3973 -- attributes (Size and Alignment) do not affect representation from
3974 -- the point of view of this test.
3976 if Base_Type
(T1
) = Base_Type
(T2
) then
3979 elsif Is_Private_Type
(Base_Type
(T2
))
3980 and then Base_Type
(T1
) = Full_View
(Base_Type
(T2
))
3985 -- Tagged types never have differing representations
3987 if Is_Tagged_Type
(T1
) then
3991 -- Representations are definitely different if conventions differ
3993 if Convention
(T1
) /= Convention
(T2
) then
3997 -- Representations are different if component alignments differ
3999 if (Is_Record_Type
(T1
) or else Is_Array_Type
(T1
))
4001 (Is_Record_Type
(T2
) or else Is_Array_Type
(T2
))
4002 and then Component_Alignment
(T1
) /= Component_Alignment
(T2
)
4007 -- For arrays, the only real issue is component size. If we know the
4008 -- component size for both arrays, and it is the same, then that's
4009 -- good enough to know we don't have a change of representation.
4011 if Is_Array_Type
(T1
) then
4012 if Known_Component_Size
(T1
)
4013 and then Known_Component_Size
(T2
)
4014 and then Component_Size
(T1
) = Component_Size
(T2
)
4020 -- Types definitely have same representation if neither has non-standard
4021 -- representation since default representations are always consistent.
4022 -- If only one has non-standard representation, and the other does not,
4023 -- then we consider that they do not have the same representation. They
4024 -- might, but there is no way of telling early enough.
4026 if Has_Non_Standard_Rep
(T1
) then
4027 if not Has_Non_Standard_Rep
(T2
) then
4031 return not Has_Non_Standard_Rep
(T2
);
4034 -- Here the two types both have non-standard representation, and we need
4035 -- to determine if they have the same non-standard representation.
4037 -- For arrays, we simply need to test if the component sizes are the
4038 -- same. Pragma Pack is reflected in modified component sizes, so this
4039 -- check also deals with pragma Pack.
4041 if Is_Array_Type
(T1
) then
4042 return Component_Size
(T1
) = Component_Size
(T2
);
4044 -- Tagged types always have the same representation, because it is not
4045 -- possible to specify different representations for common fields.
4047 elsif Is_Tagged_Type
(T1
) then
4050 -- Case of record types
4052 elsif Is_Record_Type
(T1
) then
4054 -- Packed status must conform
4056 if Is_Packed
(T1
) /= Is_Packed
(T2
) then
4059 -- Otherwise we must check components. Typ2 maybe a constrained
4060 -- subtype with fewer components, so we compare the components
4061 -- of the base types.
4064 Record_Case
: declare
4065 CD1
, CD2
: Entity_Id
;
4067 function Same_Rep
return Boolean;
4068 -- CD1 and CD2 are either components or discriminants. This
4069 -- function tests whether the two have the same representation
4075 function Same_Rep
return Boolean is
4077 if No
(Component_Clause
(CD1
)) then
4078 return No
(Component_Clause
(CD2
));
4082 Present
(Component_Clause
(CD2
))
4084 Component_Bit_Offset
(CD1
) = Component_Bit_Offset
(CD2
)
4086 Esize
(CD1
) = Esize
(CD2
);
4090 -- Start of processing for Record_Case
4093 if Has_Discriminants
(T1
) then
4094 CD1
:= First_Discriminant
(T1
);
4095 CD2
:= First_Discriminant
(T2
);
4097 -- The number of discriminants may be different if the
4098 -- derived type has fewer (constrained by values). The
4099 -- invisible discriminants retain the representation of
4100 -- the original, so the discrepancy does not per se
4101 -- indicate a different representation.
4104 and then Present
(CD2
)
4106 if not Same_Rep
then
4109 Next_Discriminant
(CD1
);
4110 Next_Discriminant
(CD2
);
4115 CD1
:= First_Component
(Underlying_Type
(Base_Type
(T1
)));
4116 CD2
:= First_Component
(Underlying_Type
(Base_Type
(T2
)));
4118 while Present
(CD1
) loop
4119 if not Same_Rep
then
4122 Next_Component
(CD1
);
4123 Next_Component
(CD2
);
4131 -- For enumeration types, we must check each literal to see if the
4132 -- representation is the same. Note that we do not permit enumeration
4133 -- representation clauses for Character and Wide_Character, so these
4134 -- cases were already dealt with.
4136 elsif Is_Enumeration_Type
(T1
) then
4138 Enumeration_Case
: declare
4142 L1
:= First_Literal
(T1
);
4143 L2
:= First_Literal
(T2
);
4145 while Present
(L1
) loop
4146 if Enumeration_Rep
(L1
) /= Enumeration_Rep
(L2
) then
4156 end Enumeration_Case
;
4158 -- Any other types have the same representation for these purposes
4163 end Same_Representation
;
4165 --------------------
4166 -- Set_Enum_Esize --
4167 --------------------
4169 procedure Set_Enum_Esize
(T
: Entity_Id
) is
4177 -- Find the minimum standard size (8,16,32,64) that fits
4179 Lo
:= Enumeration_Rep
(Entity
(Type_Low_Bound
(T
)));
4180 Hi
:= Enumeration_Rep
(Entity
(Type_High_Bound
(T
)));
4183 if Lo
>= -Uint_2
**07 and then Hi
< Uint_2
**07 then
4184 Sz
:= Standard_Character_Size
; -- May be > 8 on some targets
4186 elsif Lo
>= -Uint_2
**15 and then Hi
< Uint_2
**15 then
4189 elsif Lo
>= -Uint_2
**31 and then Hi
< Uint_2
**31 then
4192 else pragma Assert
(Lo
>= -Uint_2
**63 and then Hi
< Uint_2
**63);
4197 if Hi
< Uint_2
**08 then
4198 Sz
:= Standard_Character_Size
; -- May be > 8 on some targets
4200 elsif Hi
< Uint_2
**16 then
4203 elsif Hi
< Uint_2
**32 then
4206 else pragma Assert
(Hi
< Uint_2
**63);
4211 -- That minimum is the proper size unless we have a foreign convention
4212 -- and the size required is 32 or less, in which case we bump the size
4213 -- up to 32. This is required for C and C++ and seems reasonable for
4214 -- all other foreign conventions.
4216 if Has_Foreign_Convention
(T
)
4217 and then Esize
(T
) < Standard_Integer_Size
4219 Init_Esize
(T
, Standard_Integer_Size
);
4225 ------------------------------
4226 -- Validate_Address_Clauses --
4227 ------------------------------
4229 procedure Validate_Address_Clauses
is
4231 for J
in Address_Clause_Checks
.First
.. Address_Clause_Checks
.Last
loop
4233 ACCR
: Address_Clause_Check_Record
4234 renames Address_Clause_Checks
.Table
(J
);
4243 -- Skip processing of this entry if warning already posted
4245 if not Address_Warning_Posted
(ACCR
.N
) then
4247 -- Get alignments. Really we should always have the alignment
4248 -- of the objects properly back annotated, but right now the
4249 -- back end fails to back annotate for address clauses???
4251 if Known_Alignment
(ACCR
.X
) then
4252 X_Alignment
:= Alignment
(ACCR
.X
);
4254 X_Alignment
:= Alignment
(Etype
(ACCR
.X
));
4257 if Known_Alignment
(ACCR
.Y
) then
4258 Y_Alignment
:= Alignment
(ACCR
.Y
);
4260 Y_Alignment
:= Alignment
(Etype
(ACCR
.Y
));
4263 -- Similarly obtain sizes
4265 if Known_Esize
(ACCR
.X
) then
4266 X_Size
:= Esize
(ACCR
.X
);
4268 X_Size
:= Esize
(Etype
(ACCR
.X
));
4271 if Known_Esize
(ACCR
.Y
) then
4272 Y_Size
:= Esize
(ACCR
.Y
);
4274 Y_Size
:= Esize
(Etype
(ACCR
.Y
));
4277 -- Check for large object overlaying smaller one
4280 and then X_Size
> Uint_0
4281 and then X_Size
> Y_Size
4284 ("?size for overlaid object is too small", ACCR
.N
);
4285 Error_Msg_Uint_1
:= X_Size
;
4287 ("\?size of & is ^", ACCR
.N
, ACCR
.X
);
4288 Error_Msg_Uint_1
:= Y_Size
;
4290 ("\?size of & is ^", ACCR
.N
, ACCR
.Y
);
4292 -- Check for inadequate alignment. Again the defensive check
4293 -- on Y_Alignment should not be needed, but because of the
4294 -- failure in back end annotation, we can have an alignment
4297 -- Note: we do not check alignments if we gave a size
4298 -- warning, since it would likely be redundant.
4300 elsif Y_Alignment
/= Uint_0
4301 and then Y_Alignment
< X_Alignment
4304 ("?specified address for& may be inconsistent "
4308 ("\?program execution may be erroneous (RM 13.3(27))",
4310 Error_Msg_Uint_1
:= X_Alignment
;
4312 ("\?alignment of & is ^",
4314 Error_Msg_Uint_1
:= Y_Alignment
;
4316 ("\?alignment of & is ^",
4322 end Validate_Address_Clauses
;
4324 -----------------------------------
4325 -- Validate_Unchecked_Conversion --
4326 -----------------------------------
4328 procedure Validate_Unchecked_Conversion
4330 Act_Unit
: Entity_Id
)
4337 -- Obtain source and target types. Note that we call Ancestor_Subtype
4338 -- here because the processing for generic instantiation always makes
4339 -- subtypes, and we want the original frozen actual types.
4341 -- If we are dealing with private types, then do the check on their
4342 -- fully declared counterparts if the full declarations have been
4343 -- encountered (they don't have to be visible, but they must exist!)
4345 Source
:= Ancestor_Subtype
(Etype
(First_Formal
(Act_Unit
)));
4347 if Is_Private_Type
(Source
)
4348 and then Present
(Underlying_Type
(Source
))
4350 Source
:= Underlying_Type
(Source
);
4353 Target
:= Ancestor_Subtype
(Etype
(Act_Unit
));
4355 -- If either type is generic, the instantiation happens within a generic
4356 -- unit, and there is nothing to check. The proper check
4357 -- will happen when the enclosing generic is instantiated.
4359 if Is_Generic_Type
(Source
) or else Is_Generic_Type
(Target
) then
4363 if Is_Private_Type
(Target
)
4364 and then Present
(Underlying_Type
(Target
))
4366 Target
:= Underlying_Type
(Target
);
4369 -- Source may be unconstrained array, but not target
4371 if Is_Array_Type
(Target
)
4372 and then not Is_Constrained
(Target
)
4375 ("unchecked conversion to unconstrained array not allowed", N
);
4379 -- Warn if conversion between two different convention pointers
4381 if Is_Access_Type
(Target
)
4382 and then Is_Access_Type
(Source
)
4383 and then Convention
(Target
) /= Convention
(Source
)
4384 and then Warn_On_Unchecked_Conversion
4386 -- Give warnings for subprogram pointers only on most targets. The
4387 -- exception is VMS, where data pointers can have different lengths
4388 -- depending on the pointer convention.
4390 if Is_Access_Subprogram_Type
(Target
)
4391 or else Is_Access_Subprogram_Type
(Source
)
4392 or else OpenVMS_On_Target
4395 ("?conversion between pointers with different conventions!", N
);
4399 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4400 -- warning when compiling GNAT-related sources.
4402 if Warn_On_Unchecked_Conversion
4403 and then not In_Predefined_Unit
(N
)
4404 and then RTU_Loaded
(Ada_Calendar
)
4406 (Chars
(Source
) = Name_Time
4408 Chars
(Target
) = Name_Time
)
4410 -- If Ada.Calendar is loaded and the name of one of the operands is
4411 -- Time, there is a good chance that this is Ada.Calendar.Time.
4414 Calendar_Time
: constant Entity_Id
:=
4415 Full_View
(RTE
(RO_CA_Time
));
4417 pragma Assert
(Present
(Calendar_Time
));
4419 if Source
= Calendar_Time
4420 or else Target
= Calendar_Time
4423 ("?representation of 'Time values may change between " &
4424 "'G'N'A'T versions", N
);
4429 -- Make entry in unchecked conversion table for later processing by
4430 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4431 -- (using values set by the back-end where possible). This is only done
4432 -- if the appropriate warning is active.
4434 if Warn_On_Unchecked_Conversion
then
4435 Unchecked_Conversions
.Append
4436 (New_Val
=> UC_Entry
'
4441 -- If both sizes are known statically now, then back end annotation
4442 -- is not required to do a proper check but if either size is not
4443 -- known statically, then we need the annotation.
4445 if Known_Static_RM_Size (Source)
4446 and then Known_Static_RM_Size (Target)
4450 Back_Annotate_Rep_Info := True;
4454 -- If unchecked conversion to access type, and access type is declared
4455 -- in the same unit as the unchecked conversion, then set the
4456 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4459 if Is_Access_Type (Target) and then
4460 In_Same_Source_Unit (Target, N)
4462 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4465 -- Generate N_Validate_Unchecked_Conversion node for back end in
4466 -- case the back end needs to perform special validation checks.
4468 -- Shouldn't this be in Exp_Ch13, since the check only gets done
4469 -- if we have full expansion and the back end is called ???
4472 Make_Validate_Unchecked_Conversion (Sloc (N));
4473 Set_Source_Type (Vnode, Source);
4474 Set_Target_Type (Vnode, Target);
4476 -- If the unchecked conversion node is in a list, just insert before it.
4477 -- If not we have some strange case, not worth bothering about.
4479 if Is_List_Member (N) then
4480 Insert_After (N, Vnode);
4482 end Validate_Unchecked_Conversion;
4484 ------------------------------------
4485 -- Validate_Unchecked_Conversions --
4486 ------------------------------------
4488 procedure Validate_Unchecked_Conversions is
4490 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4492 T : UC_Entry renames Unchecked_Conversions.Table (N);
4494 Eloc : constant Source_Ptr := T.Eloc;
4495 Source : constant Entity_Id := T.Source;
4496 Target : constant Entity_Id := T.Target;
4502 -- This validation check, which warns if we have unequal sizes for
4503 -- unchecked conversion, and thus potentially implementation
4504 -- dependent semantics, is one of the few occasions on which we
4505 -- use the official RM size instead of Esize. See description in
4506 -- Einfo "Handling of Type'Size Values" for details.
4508 if Serious_Errors_Detected = 0
4509 and then Known_Static_RM_Size (Source)
4510 and then Known_Static_RM_Size (Target)
4512 -- Don't do the check if warnings off for either type, note the
4513 -- deliberate use of OR here instead of OR ELSE to get the flag
4514 -- Warnings_Off_Used set for both types if appropriate.
4516 and then not (Has_Warnings_Off (Source)
4518 Has_Warnings_Off (Target))
4520 Source_Siz := RM_Size (Source);
4521 Target_Siz := RM_Size (Target);
4523 if Source_Siz /= Target_Siz then
4525 ("?types for unchecked conversion have different sizes!",
4528 if All_Errors_Mode then
4529 Error_Msg_Name_1 := Chars (Source);
4530 Error_Msg_Uint_1 := Source_Siz;
4531 Error_Msg_Name_2 := Chars (Target);
4532 Error_Msg_Uint_2 := Target_Siz;
4533 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
4535 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4537 if Is_Discrete_Type (Source)
4538 and then Is_Discrete_Type (Target)
4540 if Source_Siz > Target_Siz then
4542 ("\?^ high order bits of source will be ignored!",
4545 elsif Is_Unsigned_Type (Source) then
4547 ("\?source will be extended with ^ high order " &
4548 "zero bits?!", Eloc);
4552 ("\?source will be extended with ^ high order " &
4557 elsif Source_Siz < Target_Siz then
4558 if Is_Discrete_Type (Target) then
4559 if Bytes_Big_Endian then
4561 ("\?target value will include ^ undefined " &
4566 ("\?target value will include ^ undefined " &
4573 ("\?^ trailing bits of target value will be " &
4574 "undefined!", Eloc);
4577 else pragma Assert (Source_Siz > Target_Siz);
4579 ("\?^ trailing bits of source will be ignored!",
4586 -- If both types are access types, we need to check the alignment.
4587 -- If the alignment of both is specified, we can do it here.
4589 if Serious_Errors_Detected = 0
4590 and then Ekind (Source) in Access_Kind
4591 and then Ekind (Target) in Access_Kind
4592 and then Target_Strict_Alignment
4593 and then Present (Designated_Type (Source))
4594 and then Present (Designated_Type (Target))
4597 D_Source : constant Entity_Id := Designated_Type (Source);
4598 D_Target : constant Entity_Id := Designated_Type (Target);
4601 if Known_Alignment (D_Source)
4602 and then Known_Alignment (D_Target)
4605 Source_Align : constant Uint := Alignment (D_Source);
4606 Target_Align : constant Uint := Alignment (D_Target);
4609 if Source_Align < Target_Align
4610 and then not Is_Tagged_Type (D_Source)
4612 -- Suppress warning if warnings suppressed on either
4613 -- type or either designated type. Note the use of
4614 -- OR here instead of OR ELSE. That is intentional,
4615 -- we would like to set flag Warnings_Off_Used in
4616 -- all types for which warnings are suppressed.
4618 and then not (Has_Warnings_Off (D_Source)
4620 Has_Warnings_Off (D_Target)
4622 Has_Warnings_Off (Source)
4624 Has_Warnings_Off (Target))
4626 Error_Msg_Uint_1 := Target_Align;
4627 Error_Msg_Uint_2 := Source_Align;
4628 Error_Msg_Node_1 := D_Target;
4629 Error_Msg_Node_2 := D_Source;
4631 ("?alignment of & (^) is stricter than " &
4632 "alignment of & (^)!", Eloc);
4634 ("\?resulting access value may have invalid " &
4635 "alignment!", Eloc);
4643 end Validate_Unchecked_Conversions;