1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree
; use Atree
;
27 with Checks
; use Checks
;
28 with 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 procedure New_Stream_Subprogram
95 -- Create a subprogram renaming of a given stream attribute to the
96 -- designated subprogram and then in the tagged case, provide this as a
97 -- primitive operation, or in the non-tagged case make an appropriate TSS
98 -- entry. This is more properly an expansion activity than just semantics,
99 -- but the presence of user-defined stream functions for limited types is a
100 -- legality check, which is why this takes place here rather than in
101 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
102 -- function to be generated.
104 -- To avoid elaboration anomalies with freeze nodes, for untagged types
105 -- we generate both a subprogram declaration and a subprogram renaming
106 -- declaration, so that the attribute specification is handled as a
107 -- renaming_as_body. For tagged types, the specification is one of the
110 ----------------------------------------------
111 -- Table for Validate_Unchecked_Conversions --
112 ----------------------------------------------
114 -- The following table collects unchecked conversions for validation.
115 -- Entries are made by Validate_Unchecked_Conversion and then the
116 -- call to Validate_Unchecked_Conversions does the actual error
117 -- checking and posting of warnings. The reason for this delayed
118 -- processing is to take advantage of back-annotations of size and
119 -- alignment values performed by the back end.
121 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
122 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
123 -- will already have modified all Sloc values if the -gnatD option is set.
125 type UC_Entry
is record
126 Eloc
: Source_Ptr
; -- node used for posting warnings
127 Source
: Entity_Id
; -- source type for unchecked conversion
128 Target
: Entity_Id
; -- target type for unchecked conversion
131 package Unchecked_Conversions
is new Table
.Table
(
132 Table_Component_Type
=> UC_Entry
,
133 Table_Index_Type
=> Int
,
134 Table_Low_Bound
=> 1,
136 Table_Increment
=> 200,
137 Table_Name
=> "Unchecked_Conversions");
139 ----------------------------------------
140 -- Table for Validate_Address_Clauses --
141 ----------------------------------------
143 -- If an address clause has the form
145 -- for X'Address use Expr
147 -- where Expr is of the form Y'Address or recursively is a reference
148 -- to a constant of either of these forms, and X and Y are entities of
149 -- objects, then if Y has a smaller alignment than X, that merits a
150 -- warning about possible bad alignment. The following table collects
151 -- address clauses of this kind. We put these in a table so that they
152 -- can be checked after the back end has completed annotation of the
153 -- alignments of objects, since we can catch more cases that way.
155 type Address_Clause_Check_Record
is record
157 -- The address clause
160 -- The entity of the object overlaying Y
163 -- The entity of the object being overlaid
166 -- Whether the address is offseted within Y
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 -- Adjust_Record_For_Reverse_Bit_Order --
179 -----------------------------------------
181 procedure Adjust_Record_For_Reverse_Bit_Order
(R
: Entity_Id
) is
182 Max_Machine_Scalar_Size
: constant Uint
:=
184 (Standard_Long_Long_Integer_Size
);
185 -- We use this as the maximum machine scalar size in the sense of AI-133
189 SSU
: constant Uint
:= UI_From_Int
(System_Storage_Unit
);
192 -- This first loop through components does two things. First it deals
193 -- with the case of components with component clauses whose length is
194 -- greater than the maximum machine scalar size (either accepting them
195 -- or rejecting as needed). Second, it counts the number of components
196 -- with component clauses whose length does not exceed this maximum for
200 Comp
:= First_Component_Or_Discriminant
(R
);
201 while Present
(Comp
) loop
203 CC
: constant Node_Id
:= Component_Clause
(Comp
);
208 Fbit
: constant Uint
:= Static_Integer
(First_Bit
(CC
));
211 -- Case of component with size > max machine scalar
213 if Esize
(Comp
) > Max_Machine_Scalar_Size
then
215 -- Must begin on byte boundary
217 if Fbit
mod SSU
/= 0 then
219 ("illegal first bit value for reverse bit order",
221 Error_Msg_Uint_1
:= SSU
;
222 Error_Msg_Uint_2
:= Max_Machine_Scalar_Size
;
225 ("\must be a multiple of ^ if size greater than ^",
228 -- Must end on byte boundary
230 elsif Esize
(Comp
) mod SSU
/= 0 then
232 ("illegal last bit value for reverse bit order",
234 Error_Msg_Uint_1
:= SSU
;
235 Error_Msg_Uint_2
:= Max_Machine_Scalar_Size
;
238 ("\must be a multiple of ^ if size greater than ^",
241 -- OK, give warning if enabled
243 elsif Warn_On_Reverse_Bit_Order
then
245 ("multi-byte field specified with non-standard"
246 & " Bit_Order?", CC
);
248 if Bytes_Big_Endian
then
250 ("\bytes are not reversed "
251 & "(component is big-endian)?", CC
);
254 ("\bytes are not reversed "
255 & "(component is little-endian)?", CC
);
259 -- Case where size is not greater than max machine
260 -- scalar. For now, we just count these.
263 Num_CC
:= Num_CC
+ 1;
269 Next_Component_Or_Discriminant
(Comp
);
272 -- We need to sort the component clauses on the basis of the Position
273 -- values in the clause, so we can group clauses with the same Position.
274 -- together to determine the relevant machine scalar size.
277 Comps
: array (0 .. Num_CC
) of Entity_Id
;
278 -- Array to collect component and discriminant entities. The data
279 -- starts at index 1, the 0'th entry is for the sort routine.
281 function CP_Lt
(Op1
, Op2
: Natural) return Boolean;
282 -- Compare routine for Sort
284 procedure CP_Move
(From
: Natural; To
: Natural);
285 -- Move routine for Sort
287 package Sorting
is new GNAT
.Heap_Sort_G
(CP_Move
, CP_Lt
);
291 -- Start and stop positions in component list of set of components
292 -- with the same starting position (that constitute components in
293 -- a single machine scalar).
296 -- Maximum last bit value of any component in this set
299 -- Corresponding machine scalar size
305 function CP_Lt
(Op1
, Op2
: Natural) return Boolean is
307 return Position
(Component_Clause
(Comps
(Op1
))) <
308 Position
(Component_Clause
(Comps
(Op2
)));
315 procedure CP_Move
(From
: Natural; To
: Natural) is
317 Comps
(To
) := Comps
(From
);
321 -- Collect the component clauses
324 Comp
:= First_Component_Or_Discriminant
(R
);
325 while Present
(Comp
) loop
326 if Present
(Component_Clause
(Comp
))
327 and then Esize
(Comp
) <= Max_Machine_Scalar_Size
329 Num_CC
:= Num_CC
+ 1;
330 Comps
(Num_CC
) := Comp
;
333 Next_Component_Or_Discriminant
(Comp
);
336 -- Sort by ascending position number
338 Sorting
.Sort
(Num_CC
);
340 -- We now have all the components whose size does not exceed the max
341 -- machine scalar value, sorted by starting position. In this loop
342 -- we gather groups of clauses starting at the same position, to
343 -- process them in accordance with Ada 2005 AI-133.
346 while Stop
< Num_CC
loop
350 Static_Integer
(Last_Bit
(Component_Clause
(Comps
(Start
))));
351 while Stop
< Num_CC
loop
353 (Position
(Component_Clause
(Comps
(Stop
+ 1)))) =
355 (Position
(Component_Clause
(Comps
(Stop
))))
362 (Last_Bit
(Component_Clause
(Comps
(Stop
)))));
368 -- Now we have a group of component clauses from Start to Stop
369 -- whose positions are identical, and MaxL is the maximum last bit
370 -- value of any of these components.
372 -- We need to determine the corresponding machine scalar size.
373 -- This loop assumes that machine scalar sizes are even, and that
374 -- each possible machine scalar has twice as many bits as the
377 MSS
:= Max_Machine_Scalar_Size
;
379 and then (MSS
/ 2) >= SSU
380 and then (MSS
/ 2) > MaxL
385 -- Here is where we fix up the Component_Bit_Offset value to
386 -- account for the reverse bit order. Some examples of what needs
387 -- to be done for the case of a machine scalar size of 8 are:
389 -- First_Bit .. Last_Bit Component_Bit_Offset
401 -- The general rule is that the first bit is obtained by
402 -- subtracting the old ending bit from machine scalar size - 1.
404 for C
in Start
.. Stop
loop
406 Comp
: constant Entity_Id
:= Comps
(C
);
407 CC
: constant Node_Id
:= Component_Clause
(Comp
);
408 LB
: constant Uint
:= Static_Integer
(Last_Bit
(CC
));
409 NFB
: constant Uint
:= MSS
- Uint_1
- LB
;
410 NLB
: constant Uint
:= NFB
+ Esize
(Comp
) - 1;
411 Pos
: constant Uint
:= Static_Integer
(Position
(CC
));
414 if Warn_On_Reverse_Bit_Order
then
415 Error_Msg_Uint_1
:= MSS
;
417 ("info: reverse bit order in machine " &
418 "scalar of length^?", First_Bit
(CC
));
419 Error_Msg_Uint_1
:= NFB
;
420 Error_Msg_Uint_2
:= NLB
;
422 if Bytes_Big_Endian
then
424 ("?\info: big-endian range for "
425 & "component & is ^ .. ^",
426 First_Bit
(CC
), Comp
);
429 ("?\info: little-endian range "
430 & "for component & is ^ .. ^",
431 First_Bit
(CC
), Comp
);
435 Set_Component_Bit_Offset
(Comp
, Pos
* SSU
+ NFB
);
436 Set_Normalized_First_Bit
(Comp
, NFB
mod SSU
);
441 end Adjust_Record_For_Reverse_Bit_Order
;
443 --------------------------------------
444 -- Alignment_Check_For_Esize_Change --
445 --------------------------------------
447 procedure Alignment_Check_For_Esize_Change
(Typ
: Entity_Id
) is
449 -- If the alignment is known, and not set by a rep clause, and is
450 -- inconsistent with the size being set, then reset it to unknown,
451 -- we assume in this case that the size overrides the inherited
452 -- alignment, and that the alignment must be recomputed.
454 if Known_Alignment
(Typ
)
455 and then not Has_Alignment_Clause
(Typ
)
456 and then Esize
(Typ
) mod (Alignment
(Typ
) * SSU
) /= 0
458 Init_Alignment
(Typ
);
460 end Alignment_Check_For_Esize_Change
;
462 -----------------------
463 -- Analyze_At_Clause --
464 -----------------------
466 -- An at clause is replaced by the corresponding Address attribute
467 -- definition clause that is the preferred approach in Ada 95.
469 procedure Analyze_At_Clause
(N
: Node_Id
) is
470 CS
: constant Boolean := Comes_From_Source
(N
);
473 -- This is an obsolescent feature
475 Check_Restriction
(No_Obsolescent_Features
, N
);
477 if Warn_On_Obsolescent_Feature
then
479 ("at clause is an obsolescent feature (RM J.7(2))?", N
);
481 ("\use address attribute definition clause instead?", N
);
484 -- Rewrite as address clause
487 Make_Attribute_Definition_Clause
(Sloc
(N
),
488 Name
=> Identifier
(N
),
489 Chars
=> Name_Address
,
490 Expression
=> Expression
(N
)));
492 -- We preserve Comes_From_Source, since logically the clause still
493 -- comes from the source program even though it is changed in form.
495 Set_Comes_From_Source
(N
, CS
);
497 -- Analyze rewritten clause
499 Analyze_Attribute_Definition_Clause
(N
);
500 end Analyze_At_Clause
;
502 -----------------------------------------
503 -- Analyze_Attribute_Definition_Clause --
504 -----------------------------------------
506 procedure Analyze_Attribute_Definition_Clause
(N
: Node_Id
) is
507 Loc
: constant Source_Ptr
:= Sloc
(N
);
508 Nam
: constant Node_Id
:= Name
(N
);
509 Attr
: constant Name_Id
:= Chars
(N
);
510 Expr
: constant Node_Id
:= Expression
(N
);
511 Id
: constant Attribute_Id
:= Get_Attribute_Id
(Attr
);
515 FOnly
: Boolean := False;
516 -- Reset to True for subtype specific attribute (Alignment, Size)
517 -- and for stream attributes, i.e. those cases where in the call
518 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
519 -- rules are checked. Note that the case of stream attributes is not
520 -- clear from the RM, but see AI95-00137. Also, the RM seems to
521 -- disallow Storage_Size for derived task types, but that is also
522 -- clearly unintentional.
524 procedure Analyze_Stream_TSS_Definition
(TSS_Nam
: TSS_Name_Type
);
525 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
526 -- definition clauses.
528 -----------------------------------
529 -- Analyze_Stream_TSS_Definition --
530 -----------------------------------
532 procedure Analyze_Stream_TSS_Definition
(TSS_Nam
: TSS_Name_Type
) is
533 Subp
: Entity_Id
:= Empty
;
538 Is_Read
: constant Boolean := (TSS_Nam
= TSS_Stream_Read
);
540 function Has_Good_Profile
(Subp
: Entity_Id
) return Boolean;
541 -- Return true if the entity is a subprogram with an appropriate
542 -- profile for the attribute being defined.
544 ----------------------
545 -- Has_Good_Profile --
546 ----------------------
548 function Has_Good_Profile
(Subp
: Entity_Id
) return Boolean is
550 Is_Function
: constant Boolean := (TSS_Nam
= TSS_Stream_Input
);
551 Expected_Ekind
: constant array (Boolean) of Entity_Kind
:=
552 (False => E_Procedure
, True => E_Function
);
556 if Ekind
(Subp
) /= Expected_Ekind
(Is_Function
) then
560 F
:= First_Formal
(Subp
);
563 or else Ekind
(Etype
(F
)) /= E_Anonymous_Access_Type
564 or else Designated_Type
(Etype
(F
)) /=
565 Class_Wide_Type
(RTE
(RE_Root_Stream_Type
))
570 if not Is_Function
then
574 Expected_Mode
: constant array (Boolean) of Entity_Kind
:=
575 (False => E_In_Parameter
,
576 True => E_Out_Parameter
);
578 if Parameter_Mode
(F
) /= Expected_Mode
(Is_Read
) then
589 return Base_Type
(Typ
) = Base_Type
(Ent
)
590 and then No
(Next_Formal
(F
));
591 end Has_Good_Profile
;
593 -- Start of processing for Analyze_Stream_TSS_Definition
598 if not Is_Type
(U_Ent
) then
599 Error_Msg_N
("local name must be a subtype", Nam
);
603 Pnam
:= TSS
(Base_Type
(U_Ent
), TSS_Nam
);
605 -- If Pnam is present, it can be either inherited from an ancestor
606 -- type (in which case it is legal to redefine it for this type), or
607 -- be a previous definition of the attribute for the same type (in
608 -- which case it is illegal).
610 -- In the first case, it will have been analyzed already, and we
611 -- can check that its profile does not match the expected profile
612 -- for a stream attribute of U_Ent. In the second case, either Pnam
613 -- has been analyzed (and has the expected profile), or it has not
614 -- been analyzed yet (case of a type that has not been frozen yet
615 -- and for which the stream attribute has been set using Set_TSS).
618 and then (No
(First_Entity
(Pnam
)) or else Has_Good_Profile
(Pnam
))
620 Error_Msg_Sloc
:= Sloc
(Pnam
);
621 Error_Msg_Name_1
:= Attr
;
622 Error_Msg_N
("% attribute already defined #", Nam
);
628 if Is_Entity_Name
(Expr
) then
629 if not Is_Overloaded
(Expr
) then
630 if Has_Good_Profile
(Entity
(Expr
)) then
631 Subp
:= Entity
(Expr
);
635 Get_First_Interp
(Expr
, I
, It
);
636 while Present
(It
.Nam
) loop
637 if Has_Good_Profile
(It
.Nam
) then
642 Get_Next_Interp
(I
, It
);
647 if Present
(Subp
) then
648 if Is_Abstract_Subprogram
(Subp
) then
649 Error_Msg_N
("stream subprogram must not be abstract", Expr
);
653 Set_Entity
(Expr
, Subp
);
654 Set_Etype
(Expr
, Etype
(Subp
));
656 New_Stream_Subprogram
(N
, U_Ent
, Subp
, TSS_Nam
);
659 Error_Msg_Name_1
:= Attr
;
660 Error_Msg_N
("incorrect expression for% attribute", Expr
);
662 end Analyze_Stream_TSS_Definition
;
664 -- Start of processing for Analyze_Attribute_Definition_Clause
667 -- Process Ignore_Rep_Clauses option
669 if Ignore_Rep_Clauses
then
672 -- The following should be ignored. They do not affect legality
673 -- and may be target dependent. The basic idea of -gnatI is to
674 -- ignore any rep clauses that may be target dependent but do not
675 -- affect legality (except possibly to be rejected because they
676 -- are incompatible with the compilation target).
678 when Attribute_Address |
679 Attribute_Alignment |
680 Attribute_Bit_Order |
681 Attribute_Component_Size |
682 Attribute_Machine_Radix |
683 Attribute_Object_Size |
686 Attribute_Stream_Size |
687 Attribute_Value_Size
=>
689 Rewrite
(N
, Make_Null_Statement
(Sloc
(N
)));
692 -- The following should not be ignored, because in the first place
693 -- they are reasonably portable, and should not cause problems in
694 -- compiling code from another target, and also they do affect
695 -- legality, e.g. failing to provide a stream attribute for a
696 -- type may make a program illegal.
698 when Attribute_External_Tag |
702 Attribute_Storage_Pool |
703 Attribute_Storage_Size |
707 -- Other cases are errors, which will be caught below
717 if Rep_Item_Too_Early
(Ent
, N
) then
721 -- Rep clause applies to full view of incomplete type or private type if
722 -- we have one (if not, this is a premature use of the type). However,
723 -- certain semantic checks need to be done on the specified entity (i.e.
724 -- the private view), so we save it in Ent.
726 if Is_Private_Type
(Ent
)
727 and then Is_Derived_Type
(Ent
)
728 and then not Is_Tagged_Type
(Ent
)
729 and then No
(Full_View
(Ent
))
731 -- If this is a private type whose completion is a derivation from
732 -- another private type, there is no full view, and the attribute
733 -- belongs to the type itself, not its underlying parent.
737 elsif Ekind
(Ent
) = E_Incomplete_Type
then
739 -- The attribute applies to the full view, set the entity of the
740 -- attribute definition accordingly.
742 Ent
:= Underlying_Type
(Ent
);
744 Set_Entity
(Nam
, Ent
);
747 U_Ent
:= Underlying_Type
(Ent
);
750 -- Complete other routine error checks
752 if Etype
(Nam
) = Any_Type
then
755 elsif Scope
(Ent
) /= Current_Scope
then
756 Error_Msg_N
("entity must be declared in this scope", Nam
);
759 elsif No
(U_Ent
) then
762 elsif Is_Type
(U_Ent
)
763 and then not Is_First_Subtype
(U_Ent
)
764 and then Id
/= Attribute_Object_Size
765 and then Id
/= Attribute_Value_Size
766 and then not From_At_Mod
(N
)
768 Error_Msg_N
("cannot specify attribute for subtype", Nam
);
772 -- Switch on particular attribute
780 -- Address attribute definition clause
782 when Attribute_Address
=> Address
: begin
784 -- A little error check, catch for X'Address use X'Address;
786 if Nkind
(Nam
) = N_Identifier
787 and then Nkind
(Expr
) = N_Attribute_Reference
788 and then Attribute_Name
(Expr
) = Name_Address
789 and then Nkind
(Prefix
(Expr
)) = N_Identifier
790 and then Chars
(Nam
) = Chars
(Prefix
(Expr
))
793 ("address for & is self-referencing", Prefix
(Expr
), Ent
);
797 -- Not that special case, carry on with analysis of expression
799 Analyze_And_Resolve
(Expr
, RTE
(RE_Address
));
801 if Present
(Address_Clause
(U_Ent
)) then
802 Error_Msg_N
("address already given for &", Nam
);
804 -- Case of address clause for subprogram
806 elsif Is_Subprogram
(U_Ent
) then
807 if Has_Homonym
(U_Ent
) then
809 ("address clause cannot be given " &
810 "for overloaded subprogram",
815 -- For subprograms, all address clauses are permitted, and we
816 -- mark the subprogram as having a deferred freeze so that Gigi
817 -- will not elaborate it too soon.
819 -- Above needs more comments, what is too soon about???
821 Set_Has_Delayed_Freeze
(U_Ent
);
823 -- Case of address clause for entry
825 elsif Ekind
(U_Ent
) = E_Entry
then
826 if Nkind
(Parent
(N
)) = N_Task_Body
then
828 ("entry address must be specified in task spec", Nam
);
832 -- For entries, we require a constant address
834 Check_Constant_Address_Clause
(Expr
, U_Ent
);
836 -- Special checks for task types
838 if Is_Task_Type
(Scope
(U_Ent
))
839 and then Comes_From_Source
(Scope
(U_Ent
))
842 ("?entry address declared for entry in task type", N
);
844 ("\?only one task can be declared of this type", N
);
847 -- Entry address clauses are obsolescent
849 Check_Restriction
(No_Obsolescent_Features
, N
);
851 if Warn_On_Obsolescent_Feature
then
853 ("attaching interrupt to task entry is an " &
854 "obsolescent feature (RM J.7.1)?", N
);
856 ("\use interrupt procedure instead?", N
);
859 -- Case of an address clause for a controlled object which we
860 -- consider to be erroneous.
862 elsif Is_Controlled
(Etype
(U_Ent
))
863 or else Has_Controlled_Component
(Etype
(U_Ent
))
866 ("?controlled object& must not be overlaid", Nam
, U_Ent
);
868 ("\?Program_Error will be raised at run time", Nam
);
869 Insert_Action
(Declaration_Node
(U_Ent
),
870 Make_Raise_Program_Error
(Loc
,
871 Reason
=> PE_Overlaid_Controlled_Object
));
874 -- Case of address clause for a (non-controlled) object
877 Ekind
(U_Ent
) = E_Variable
879 Ekind
(U_Ent
) = E_Constant
882 Expr
: constant Node_Id
:= Expression
(N
);
888 -- Exported variables cannot have an address clause,
889 -- because this cancels the effect of the pragma Export
891 if Is_Exported
(U_Ent
) then
893 ("cannot export object with address clause", Nam
);
897 Find_Overlaid_Entity
(N
, O_Ent
, Off
);
899 -- Overlaying controlled objects is erroneous
902 and then (Has_Controlled_Component
(Etype
(O_Ent
))
903 or else Is_Controlled
(Etype
(O_Ent
)))
906 ("?cannot overlay with controlled object", Expr
);
908 ("\?Program_Error will be raised at run time", Expr
);
909 Insert_Action
(Declaration_Node
(U_Ent
),
910 Make_Raise_Program_Error
(Loc
,
911 Reason
=> PE_Overlaid_Controlled_Object
));
914 elsif Present
(O_Ent
)
915 and then Ekind
(U_Ent
) = E_Constant
916 and then not Is_Constant_Object
(O_Ent
)
918 Error_Msg_N
("constant overlays a variable?", Expr
);
920 elsif Present
(Renamed_Object
(U_Ent
)) then
922 ("address clause not allowed"
923 & " for a renaming declaration (RM 13.1(6))", Nam
);
926 -- Imported variables can have an address clause, but then
927 -- the import is pretty meaningless except to suppress
928 -- initializations, so we do not need such variables to
929 -- be statically allocated (and in fact it causes trouble
930 -- if the address clause is a local value).
932 elsif Is_Imported
(U_Ent
) then
933 Set_Is_Statically_Allocated
(U_Ent
, False);
936 -- We mark a possible modification of a variable with an
937 -- address clause, since it is likely aliasing is occurring.
939 Note_Possible_Modification
(Nam
, Sure
=> False);
941 -- Here we are checking for explicit overlap of one variable
942 -- by another, and if we find this then mark the overlapped
943 -- variable as also being volatile to prevent unwanted
944 -- optimizations. This is a significant pessimization so
945 -- avoid it when there is an offset, i.e. when the object
946 -- is composite; they cannot be optimized easily anyway.
949 and then Is_Object
(O_Ent
)
952 Set_Treat_As_Volatile
(O_Ent
);
955 -- Legality checks on the address clause for initialized
956 -- objects is deferred until the freeze point, because
957 -- a subsequent pragma might indicate that the object is
958 -- imported and thus not initialized.
960 Set_Has_Delayed_Freeze
(U_Ent
);
962 -- If an initialization call has been generated for this
963 -- object, it needs to be deferred to after the freeze node
964 -- we have just now added, otherwise GIGI will see a
965 -- reference to the variable (as actual to the IP call)
966 -- before its definition.
969 Init_Call
: constant Node_Id
:= Find_Init_Call
(U_Ent
, N
);
971 if Present
(Init_Call
) then
973 Append_Freeze_Action
(U_Ent
, Init_Call
);
977 if Is_Exported
(U_Ent
) then
979 ("& cannot be exported if an address clause is given",
982 ("\define and export a variable " &
983 "that holds its address instead",
987 -- Entity has delayed freeze, so we will generate an
988 -- alignment check at the freeze point unless suppressed.
990 if not Range_Checks_Suppressed
(U_Ent
)
991 and then not Alignment_Checks_Suppressed
(U_Ent
)
993 Set_Check_Address_Alignment
(N
);
996 -- Kill the size check code, since we are not allocating
997 -- the variable, it is somewhere else.
999 Kill_Size_Check_Code
(U_Ent
);
1001 -- If the address clause is of the form:
1003 -- for Y'Address use X'Address
1007 -- Const : constant Address := X'Address;
1009 -- for Y'Address use Const;
1011 -- then we make an entry in the table for checking the size
1012 -- and alignment of the overlaying variable. We defer this
1013 -- check till after code generation to take full advantage
1014 -- of the annotation done by the back end. This entry is
1015 -- only made if the address clause comes from source.
1017 if Address_Clause_Overlay_Warnings
1018 and then Comes_From_Source
(N
)
1019 and then Present
(O_Ent
)
1020 and then Is_Object
(O_Ent
)
1022 Address_Clause_Checks
.Append
((N
, U_Ent
, O_Ent
, Off
));
1024 -- If variable overlays a constant view, and we are
1025 -- warning on overlays, then mark the variable as
1026 -- overlaying a constant (we will give warnings later
1027 -- if this variable is assigned).
1029 if Is_Constant_Object
(O_Ent
)
1030 and then Ekind
(U_Ent
) = E_Variable
1032 Set_Overlays_Constant
(U_Ent
);
1037 -- Not a valid entity for an address clause
1040 Error_Msg_N
("address cannot be given for &", Nam
);
1048 -- Alignment attribute definition clause
1050 when Attribute_Alignment
=> Alignment_Block
: declare
1051 Align
: constant Uint
:= Get_Alignment_Value
(Expr
);
1056 if not Is_Type
(U_Ent
)
1057 and then Ekind
(U_Ent
) /= E_Variable
1058 and then Ekind
(U_Ent
) /= E_Constant
1060 Error_Msg_N
("alignment cannot be given for &", Nam
);
1062 elsif Has_Alignment_Clause
(U_Ent
) then
1063 Error_Msg_Sloc
:= Sloc
(Alignment_Clause
(U_Ent
));
1064 Error_Msg_N
("alignment clause previously given#", N
);
1066 elsif Align
/= No_Uint
then
1067 Set_Has_Alignment_Clause
(U_Ent
);
1068 Set_Alignment
(U_Ent
, Align
);
1070 end Alignment_Block
;
1076 -- Bit_Order attribute definition clause
1078 when Attribute_Bit_Order
=> Bit_Order
: declare
1080 if not Is_Record_Type
(U_Ent
) then
1082 ("Bit_Order can only be defined for record type", Nam
);
1085 Analyze_And_Resolve
(Expr
, RTE
(RE_Bit_Order
));
1087 if Etype
(Expr
) = Any_Type
then
1090 elsif not Is_Static_Expression
(Expr
) then
1091 Flag_Non_Static_Expr
1092 ("Bit_Order requires static expression!", Expr
);
1095 if (Expr_Value
(Expr
) = 0) /= Bytes_Big_Endian
then
1096 Set_Reverse_Bit_Order
(U_Ent
, True);
1102 --------------------
1103 -- Component_Size --
1104 --------------------
1106 -- Component_Size attribute definition clause
1108 when Attribute_Component_Size
=> Component_Size_Case
: declare
1109 Csize
: constant Uint
:= Static_Integer
(Expr
);
1112 New_Ctyp
: Entity_Id
;
1116 if not Is_Array_Type
(U_Ent
) then
1117 Error_Msg_N
("component size requires array type", Nam
);
1121 Btype
:= Base_Type
(U_Ent
);
1123 if Has_Component_Size_Clause
(Btype
) then
1125 ("component size clause for& previously given", Nam
);
1127 elsif Csize
/= No_Uint
then
1128 Check_Size
(Expr
, Component_Type
(Btype
), Csize
, Biased
);
1130 if Has_Aliased_Components
(Btype
)
1133 and then Csize
/= 16
1136 ("component size incorrect for aliased components", N
);
1140 -- For the biased case, build a declaration for a subtype
1141 -- that will be used to represent the biased subtype that
1142 -- reflects the biased representation of components. We need
1143 -- this subtype to get proper conversions on referencing
1144 -- elements of the array. Note that component size clauses
1145 -- are ignored in VM mode.
1147 if VM_Target
= No_VM
then
1150 Make_Defining_Identifier
(Loc
,
1152 New_External_Name
(Chars
(U_Ent
), 'C', 0, 'T'));
1155 Make_Subtype_Declaration
(Loc
,
1156 Defining_Identifier
=> New_Ctyp
,
1157 Subtype_Indication
=>
1158 New_Occurrence_Of
(Component_Type
(Btype
), Loc
));
1160 Set_Parent
(Decl
, N
);
1161 Analyze
(Decl
, Suppress
=> All_Checks
);
1163 Set_Has_Delayed_Freeze
(New_Ctyp
, False);
1164 Set_Esize
(New_Ctyp
, Csize
);
1165 Set_RM_Size
(New_Ctyp
, Csize
);
1166 Init_Alignment
(New_Ctyp
);
1167 Set_Has_Biased_Representation
(New_Ctyp
, True);
1168 Set_Is_Itype
(New_Ctyp
, True);
1169 Set_Associated_Node_For_Itype
(New_Ctyp
, U_Ent
);
1171 Set_Component_Type
(Btype
, New_Ctyp
);
1173 if Warn_On_Biased_Representation
then
1175 ("?component size clause forces biased "
1176 & "representation", N
);
1180 Set_Component_Size
(Btype
, Csize
);
1182 -- For VM case, we ignore component size clauses
1185 -- Give a warning unless we are in GNAT mode, in which case
1186 -- the warning is suppressed since it is not useful.
1188 if not GNAT_Mode
then
1190 ("?component size ignored in this configuration", N
);
1194 Set_Has_Component_Size_Clause
(Btype
, True);
1195 Set_Has_Non_Standard_Rep
(Btype
, True);
1197 end Component_Size_Case
;
1203 when Attribute_External_Tag
=> External_Tag
:
1205 if not Is_Tagged_Type
(U_Ent
) then
1206 Error_Msg_N
("should be a tagged type", Nam
);
1209 Analyze_And_Resolve
(Expr
, Standard_String
);
1211 if not Is_Static_Expression
(Expr
) then
1212 Flag_Non_Static_Expr
1213 ("static string required for tag name!", Nam
);
1216 if VM_Target
= No_VM
then
1217 Set_Has_External_Tag_Rep_Clause
(U_Ent
);
1219 Error_Msg_Name_1
:= Attr
;
1221 ("% attribute unsupported in this configuration", Nam
);
1224 if not Is_Library_Level_Entity
(U_Ent
) then
1226 ("?non-unique external tag supplied for &", N
, U_Ent
);
1228 ("?\same external tag applies to all subprogram calls", N
);
1230 ("?\corresponding internal tag cannot be obtained", N
);
1238 when Attribute_Input
=>
1239 Analyze_Stream_TSS_Definition
(TSS_Stream_Input
);
1240 Set_Has_Specified_Stream_Input
(Ent
);
1246 -- Machine radix attribute definition clause
1248 when Attribute_Machine_Radix
=> Machine_Radix
: declare
1249 Radix
: constant Uint
:= Static_Integer
(Expr
);
1252 if not Is_Decimal_Fixed_Point_Type
(U_Ent
) then
1253 Error_Msg_N
("decimal fixed-point type expected for &", Nam
);
1255 elsif Has_Machine_Radix_Clause
(U_Ent
) then
1256 Error_Msg_Sloc
:= Sloc
(Alignment_Clause
(U_Ent
));
1257 Error_Msg_N
("machine radix clause previously given#", N
);
1259 elsif Radix
/= No_Uint
then
1260 Set_Has_Machine_Radix_Clause
(U_Ent
);
1261 Set_Has_Non_Standard_Rep
(Base_Type
(U_Ent
));
1265 elsif Radix
= 10 then
1266 Set_Machine_Radix_10
(U_Ent
);
1268 Error_Msg_N
("machine radix value must be 2 or 10", Expr
);
1277 -- Object_Size attribute definition clause
1279 when Attribute_Object_Size
=> Object_Size
: declare
1280 Size
: constant Uint
:= Static_Integer
(Expr
);
1283 pragma Warnings
(Off
, Biased
);
1286 if not Is_Type
(U_Ent
) then
1287 Error_Msg_N
("Object_Size cannot be given for &", Nam
);
1289 elsif Has_Object_Size_Clause
(U_Ent
) then
1290 Error_Msg_N
("Object_Size already given for &", Nam
);
1293 Check_Size
(Expr
, U_Ent
, Size
, Biased
);
1301 UI_Mod
(Size
, 64) /= 0
1304 ("Object_Size must be 8, 16, 32, or multiple of 64",
1308 Set_Esize
(U_Ent
, Size
);
1309 Set_Has_Object_Size_Clause
(U_Ent
);
1310 Alignment_Check_For_Esize_Change
(U_Ent
);
1318 when Attribute_Output
=>
1319 Analyze_Stream_TSS_Definition
(TSS_Stream_Output
);
1320 Set_Has_Specified_Stream_Output
(Ent
);
1326 when Attribute_Read
=>
1327 Analyze_Stream_TSS_Definition
(TSS_Stream_Read
);
1328 Set_Has_Specified_Stream_Read
(Ent
);
1334 -- Size attribute definition clause
1336 when Attribute_Size
=> Size
: declare
1337 Size
: constant Uint
:= Static_Integer
(Expr
);
1344 if Has_Size_Clause
(U_Ent
) then
1345 Error_Msg_N
("size already given for &", Nam
);
1347 elsif not Is_Type
(U_Ent
)
1348 and then Ekind
(U_Ent
) /= E_Variable
1349 and then Ekind
(U_Ent
) /= E_Constant
1351 Error_Msg_N
("size cannot be given for &", Nam
);
1353 elsif Is_Array_Type
(U_Ent
)
1354 and then not Is_Constrained
(U_Ent
)
1357 ("size cannot be given for unconstrained array", Nam
);
1359 elsif Size
/= No_Uint
then
1360 if Is_Type
(U_Ent
) then
1363 Etyp
:= Etype
(U_Ent
);
1366 -- Check size, note that Gigi is in charge of checking that the
1367 -- size of an array or record type is OK. Also we do not check
1368 -- the size in the ordinary fixed-point case, since it is too
1369 -- early to do so (there may be subsequent small clause that
1370 -- affects the size). We can check the size if a small clause
1371 -- has already been given.
1373 if not Is_Ordinary_Fixed_Point_Type
(U_Ent
)
1374 or else Has_Small_Clause
(U_Ent
)
1376 Check_Size
(Expr
, Etyp
, Size
, Biased
);
1377 Set_Has_Biased_Representation
(U_Ent
, Biased
);
1379 if Biased
and Warn_On_Biased_Representation
then
1381 ("?size clause forces biased representation", N
);
1385 -- For types set RM_Size and Esize if possible
1387 if Is_Type
(U_Ent
) then
1388 Set_RM_Size
(U_Ent
, Size
);
1390 -- For scalar types, increase Object_Size to power of 2, but
1391 -- not less than a storage unit in any case (i.e., normally
1392 -- this means it will be byte addressable).
1394 if Is_Scalar_Type
(U_Ent
) then
1395 if Size
<= System_Storage_Unit
then
1396 Init_Esize
(U_Ent
, System_Storage_Unit
);
1397 elsif Size
<= 16 then
1398 Init_Esize
(U_Ent
, 16);
1399 elsif Size
<= 32 then
1400 Init_Esize
(U_Ent
, 32);
1402 Set_Esize
(U_Ent
, (Size
+ 63) / 64 * 64);
1405 -- For all other types, object size = value size. The
1406 -- backend will adjust as needed.
1409 Set_Esize
(U_Ent
, Size
);
1412 Alignment_Check_For_Esize_Change
(U_Ent
);
1414 -- For objects, set Esize only
1417 if Is_Elementary_Type
(Etyp
) then
1418 if Size
/= System_Storage_Unit
1420 Size
/= System_Storage_Unit
* 2
1422 Size
/= System_Storage_Unit
* 4
1424 Size
/= System_Storage_Unit
* 8
1426 Error_Msg_Uint_1
:= UI_From_Int
(System_Storage_Unit
);
1427 Error_Msg_Uint_2
:= Error_Msg_Uint_1
* 8;
1429 ("size for primitive object must be a power of 2"
1430 & " in the range ^-^", N
);
1434 Set_Esize
(U_Ent
, Size
);
1437 Set_Has_Size_Clause
(U_Ent
);
1445 -- Small attribute definition clause
1447 when Attribute_Small
=> Small
: declare
1448 Implicit_Base
: constant Entity_Id
:= Base_Type
(U_Ent
);
1452 Analyze_And_Resolve
(Expr
, Any_Real
);
1454 if Etype
(Expr
) = Any_Type
then
1457 elsif not Is_Static_Expression
(Expr
) then
1458 Flag_Non_Static_Expr
1459 ("small requires static expression!", Expr
);
1463 Small
:= Expr_Value_R
(Expr
);
1465 if Small
<= Ureal_0
then
1466 Error_Msg_N
("small value must be greater than zero", Expr
);
1472 if not Is_Ordinary_Fixed_Point_Type
(U_Ent
) then
1474 ("small requires an ordinary fixed point type", Nam
);
1476 elsif Has_Small_Clause
(U_Ent
) then
1477 Error_Msg_N
("small already given for &", Nam
);
1479 elsif Small
> Delta_Value
(U_Ent
) then
1481 ("small value must not be greater then delta value", Nam
);
1484 Set_Small_Value
(U_Ent
, Small
);
1485 Set_Small_Value
(Implicit_Base
, Small
);
1486 Set_Has_Small_Clause
(U_Ent
);
1487 Set_Has_Small_Clause
(Implicit_Base
);
1488 Set_Has_Non_Standard_Rep
(Implicit_Base
);
1496 -- Storage_Pool attribute definition clause
1498 when Attribute_Storage_Pool
=> Storage_Pool
: declare
1503 if Ekind
(U_Ent
) = E_Access_Subprogram_Type
then
1505 ("storage pool cannot be given for access-to-subprogram type",
1509 elsif Ekind
(U_Ent
) /= E_Access_Type
1510 and then Ekind
(U_Ent
) /= E_General_Access_Type
1513 ("storage pool can only be given for access types", Nam
);
1516 elsif Is_Derived_Type
(U_Ent
) then
1518 ("storage pool cannot be given for a derived access type",
1521 elsif Has_Storage_Size_Clause
(U_Ent
) then
1522 Error_Msg_N
("storage size already given for &", Nam
);
1525 elsif Present
(Associated_Storage_Pool
(U_Ent
)) then
1526 Error_Msg_N
("storage pool already given for &", Nam
);
1531 (Expr
, Class_Wide_Type
(RTE
(RE_Root_Storage_Pool
)));
1533 if not Denotes_Variable
(Expr
) then
1534 Error_Msg_N
("storage pool must be a variable", Expr
);
1538 if Nkind
(Expr
) = N_Type_Conversion
then
1539 T
:= Etype
(Expression
(Expr
));
1544 -- The Stack_Bounded_Pool is used internally for implementing
1545 -- access types with a Storage_Size. Since it only work
1546 -- properly when used on one specific type, we need to check
1547 -- that it is not hijacked improperly:
1548 -- type T is access Integer;
1549 -- for T'Storage_Size use n;
1550 -- type Q is access Float;
1551 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1553 if RTE_Available
(RE_Stack_Bounded_Pool
)
1554 and then Base_Type
(T
) = RTE
(RE_Stack_Bounded_Pool
)
1556 Error_Msg_N
("non-shareable internal Pool", Expr
);
1560 -- If the argument is a name that is not an entity name, then
1561 -- we construct a renaming operation to define an entity of
1562 -- type storage pool.
1564 if not Is_Entity_Name
(Expr
)
1565 and then Is_Object_Reference
(Expr
)
1568 Make_Defining_Identifier
(Loc
,
1569 Chars
=> New_Internal_Name
('P'));
1572 Rnode
: constant Node_Id
:=
1573 Make_Object_Renaming_Declaration
(Loc
,
1574 Defining_Identifier
=> Pool
,
1576 New_Occurrence_Of
(Etype
(Expr
), Loc
),
1580 Insert_Before
(N
, Rnode
);
1582 Set_Associated_Storage_Pool
(U_Ent
, Pool
);
1585 elsif Is_Entity_Name
(Expr
) then
1586 Pool
:= Entity
(Expr
);
1588 -- If pool is a renamed object, get original one. This can
1589 -- happen with an explicit renaming, and within instances.
1591 while Present
(Renamed_Object
(Pool
))
1592 and then Is_Entity_Name
(Renamed_Object
(Pool
))
1594 Pool
:= Entity
(Renamed_Object
(Pool
));
1597 if Present
(Renamed_Object
(Pool
))
1598 and then Nkind
(Renamed_Object
(Pool
)) = N_Type_Conversion
1599 and then Is_Entity_Name
(Expression
(Renamed_Object
(Pool
)))
1601 Pool
:= Entity
(Expression
(Renamed_Object
(Pool
)));
1604 Set_Associated_Storage_Pool
(U_Ent
, Pool
);
1606 elsif Nkind
(Expr
) = N_Type_Conversion
1607 and then Is_Entity_Name
(Expression
(Expr
))
1608 and then Nkind
(Original_Node
(Expr
)) = N_Attribute_Reference
1610 Pool
:= Entity
(Expression
(Expr
));
1611 Set_Associated_Storage_Pool
(U_Ent
, Pool
);
1614 Error_Msg_N
("incorrect reference to a Storage Pool", Expr
);
1623 -- Storage_Size attribute definition clause
1625 when Attribute_Storage_Size
=> Storage_Size
: declare
1626 Btype
: constant Entity_Id
:= Base_Type
(U_Ent
);
1630 if Is_Task_Type
(U_Ent
) then
1631 Check_Restriction
(No_Obsolescent_Features
, N
);
1633 if Warn_On_Obsolescent_Feature
then
1635 ("storage size clause for task is an " &
1636 "obsolescent feature (RM J.9)?", N
);
1638 ("\use Storage_Size pragma instead?", N
);
1644 if not Is_Access_Type
(U_Ent
)
1645 and then Ekind
(U_Ent
) /= E_Task_Type
1647 Error_Msg_N
("storage size cannot be given for &", Nam
);
1649 elsif Is_Access_Type
(U_Ent
) and Is_Derived_Type
(U_Ent
) then
1651 ("storage size cannot be given for a derived access type",
1654 elsif Has_Storage_Size_Clause
(Btype
) then
1655 Error_Msg_N
("storage size already given for &", Nam
);
1658 Analyze_And_Resolve
(Expr
, Any_Integer
);
1660 if Is_Access_Type
(U_Ent
) then
1661 if Present
(Associated_Storage_Pool
(U_Ent
)) then
1662 Error_Msg_N
("storage pool already given for &", Nam
);
1666 if Compile_Time_Known_Value
(Expr
)
1667 and then Expr_Value
(Expr
) = 0
1669 Set_No_Pool_Assigned
(Btype
);
1672 else -- Is_Task_Type (U_Ent)
1673 Sprag
:= Get_Rep_Pragma
(Btype
, Name_Storage_Size
);
1675 if Present
(Sprag
) then
1676 Error_Msg_Sloc
:= Sloc
(Sprag
);
1678 ("Storage_Size already specified#", Nam
);
1683 Set_Has_Storage_Size_Clause
(Btype
);
1691 when Attribute_Stream_Size
=> Stream_Size
: declare
1692 Size
: constant Uint
:= Static_Integer
(Expr
);
1695 if Ada_Version
<= Ada_95
then
1696 Check_Restriction
(No_Implementation_Attributes
, N
);
1699 if Has_Stream_Size_Clause
(U_Ent
) then
1700 Error_Msg_N
("Stream_Size already given for &", Nam
);
1702 elsif Is_Elementary_Type
(U_Ent
) then
1703 if Size
/= System_Storage_Unit
1705 Size
/= System_Storage_Unit
* 2
1707 Size
/= System_Storage_Unit
* 4
1709 Size
/= System_Storage_Unit
* 8
1711 Error_Msg_Uint_1
:= UI_From_Int
(System_Storage_Unit
);
1713 ("stream size for elementary type must be a"
1714 & " power of 2 and at least ^", N
);
1716 elsif RM_Size
(U_Ent
) > Size
then
1717 Error_Msg_Uint_1
:= RM_Size
(U_Ent
);
1719 ("stream size for elementary type must be a"
1720 & " power of 2 and at least ^", N
);
1723 Set_Has_Stream_Size_Clause
(U_Ent
);
1726 Error_Msg_N
("Stream_Size cannot be given for &", Nam
);
1734 -- Value_Size attribute definition clause
1736 when Attribute_Value_Size
=> Value_Size
: declare
1737 Size
: constant Uint
:= Static_Integer
(Expr
);
1741 if not Is_Type
(U_Ent
) then
1742 Error_Msg_N
("Value_Size cannot be given for &", Nam
);
1745 (Get_Attribute_Definition_Clause
1746 (U_Ent
, Attribute_Value_Size
))
1748 Error_Msg_N
("Value_Size already given for &", Nam
);
1750 elsif Is_Array_Type
(U_Ent
)
1751 and then not Is_Constrained
(U_Ent
)
1754 ("Value_Size cannot be given for unconstrained array", Nam
);
1757 if Is_Elementary_Type
(U_Ent
) then
1758 Check_Size
(Expr
, U_Ent
, Size
, Biased
);
1759 Set_Has_Biased_Representation
(U_Ent
, Biased
);
1761 if Biased
and Warn_On_Biased_Representation
then
1763 ("?value size clause forces biased representation", N
);
1767 Set_RM_Size
(U_Ent
, Size
);
1775 when Attribute_Write
=>
1776 Analyze_Stream_TSS_Definition
(TSS_Stream_Write
);
1777 Set_Has_Specified_Stream_Write
(Ent
);
1779 -- All other attributes cannot be set
1783 ("attribute& cannot be set with definition clause", N
);
1786 -- The test for the type being frozen must be performed after
1787 -- any expression the clause has been analyzed since the expression
1788 -- itself might cause freezing that makes the clause illegal.
1790 if Rep_Item_Too_Late
(U_Ent
, N
, FOnly
) then
1793 end Analyze_Attribute_Definition_Clause
;
1795 ----------------------------
1796 -- Analyze_Code_Statement --
1797 ----------------------------
1799 procedure Analyze_Code_Statement
(N
: Node_Id
) is
1800 HSS
: constant Node_Id
:= Parent
(N
);
1801 SBody
: constant Node_Id
:= Parent
(HSS
);
1802 Subp
: constant Entity_Id
:= Current_Scope
;
1809 -- Analyze and check we get right type, note that this implements the
1810 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1811 -- is the only way that Asm_Insn could possibly be visible.
1813 Analyze_And_Resolve
(Expression
(N
));
1815 if Etype
(Expression
(N
)) = Any_Type
then
1817 elsif Etype
(Expression
(N
)) /= RTE
(RE_Asm_Insn
) then
1818 Error_Msg_N
("incorrect type for code statement", N
);
1822 Check_Code_Statement
(N
);
1824 -- Make sure we appear in the handled statement sequence of a
1825 -- subprogram (RM 13.8(3)).
1827 if Nkind
(HSS
) /= N_Handled_Sequence_Of_Statements
1828 or else Nkind
(SBody
) /= N_Subprogram_Body
1831 ("code statement can only appear in body of subprogram", N
);
1835 -- Do remaining checks (RM 13.8(3)) if not already done
1837 if not Is_Machine_Code_Subprogram
(Subp
) then
1838 Set_Is_Machine_Code_Subprogram
(Subp
);
1840 -- No exception handlers allowed
1842 if Present
(Exception_Handlers
(HSS
)) then
1844 ("exception handlers not permitted in machine code subprogram",
1845 First
(Exception_Handlers
(HSS
)));
1848 -- No declarations other than use clauses and pragmas (we allow
1849 -- certain internally generated declarations as well).
1851 Decl
:= First
(Declarations
(SBody
));
1852 while Present
(Decl
) loop
1853 DeclO
:= Original_Node
(Decl
);
1854 if Comes_From_Source
(DeclO
)
1855 and not Nkind_In
(DeclO
, N_Pragma
,
1856 N_Use_Package_Clause
,
1858 N_Implicit_Label_Declaration
)
1861 ("this declaration not allowed in machine code subprogram",
1868 -- No statements other than code statements, pragmas, and labels.
1869 -- Again we allow certain internally generated statements.
1871 Stmt
:= First
(Statements
(HSS
));
1872 while Present
(Stmt
) loop
1873 StmtO
:= Original_Node
(Stmt
);
1874 if Comes_From_Source
(StmtO
)
1875 and then not Nkind_In
(StmtO
, N_Pragma
,
1880 ("this statement is not allowed in machine code subprogram",
1887 end Analyze_Code_Statement
;
1889 -----------------------------------------------
1890 -- Analyze_Enumeration_Representation_Clause --
1891 -----------------------------------------------
1893 procedure Analyze_Enumeration_Representation_Clause
(N
: Node_Id
) is
1894 Ident
: constant Node_Id
:= Identifier
(N
);
1895 Aggr
: constant Node_Id
:= Array_Aggregate
(N
);
1896 Enumtype
: Entity_Id
;
1902 Err
: Boolean := False;
1904 Lo
: constant Uint
:= Expr_Value
(Type_Low_Bound
(Universal_Integer
));
1905 Hi
: constant Uint
:= Expr_Value
(Type_High_Bound
(Universal_Integer
));
1910 if Ignore_Rep_Clauses
then
1914 -- First some basic error checks
1917 Enumtype
:= Entity
(Ident
);
1919 if Enumtype
= Any_Type
1920 or else Rep_Item_Too_Early
(Enumtype
, N
)
1924 Enumtype
:= Underlying_Type
(Enumtype
);
1927 if not Is_Enumeration_Type
(Enumtype
) then
1929 ("enumeration type required, found}",
1930 Ident
, First_Subtype
(Enumtype
));
1934 -- Ignore rep clause on generic actual type. This will already have
1935 -- been flagged on the template as an error, and this is the safest
1936 -- way to ensure we don't get a junk cascaded message in the instance.
1938 if Is_Generic_Actual_Type
(Enumtype
) then
1941 -- Type must be in current scope
1943 elsif Scope
(Enumtype
) /= Current_Scope
then
1944 Error_Msg_N
("type must be declared in this scope", Ident
);
1947 -- Type must be a first subtype
1949 elsif not Is_First_Subtype
(Enumtype
) then
1950 Error_Msg_N
("cannot give enumeration rep clause for subtype", N
);
1953 -- Ignore duplicate rep clause
1955 elsif Has_Enumeration_Rep_Clause
(Enumtype
) then
1956 Error_Msg_N
("duplicate enumeration rep clause ignored", N
);
1959 -- Don't allow rep clause for standard [wide_[wide_]]character
1961 elsif Is_Standard_Character_Type
(Enumtype
) then
1962 Error_Msg_N
("enumeration rep clause not allowed for this type", N
);
1965 -- Check that the expression is a proper aggregate (no parentheses)
1967 elsif Paren_Count
(Aggr
) /= 0 then
1969 ("extra parentheses surrounding aggregate not allowed",
1973 -- All tests passed, so set rep clause in place
1976 Set_Has_Enumeration_Rep_Clause
(Enumtype
);
1977 Set_Has_Enumeration_Rep_Clause
(Base_Type
(Enumtype
));
1980 -- Now we process the aggregate. Note that we don't use the normal
1981 -- aggregate code for this purpose, because we don't want any of the
1982 -- normal expansion activities, and a number of special semantic
1983 -- rules apply (including the component type being any integer type)
1985 Elit
:= First_Literal
(Enumtype
);
1987 -- First the positional entries if any
1989 if Present
(Expressions
(Aggr
)) then
1990 Expr
:= First
(Expressions
(Aggr
));
1991 while Present
(Expr
) loop
1993 Error_Msg_N
("too many entries in aggregate", Expr
);
1997 Val
:= Static_Integer
(Expr
);
1999 -- Err signals that we found some incorrect entries processing
2000 -- the list. The final checks for completeness and ordering are
2001 -- skipped in this case.
2003 if Val
= No_Uint
then
2005 elsif Val
< Lo
or else Hi
< Val
then
2006 Error_Msg_N
("value outside permitted range", Expr
);
2010 Set_Enumeration_Rep
(Elit
, Val
);
2011 Set_Enumeration_Rep_Expr
(Elit
, Expr
);
2017 -- Now process the named entries if present
2019 if Present
(Component_Associations
(Aggr
)) then
2020 Assoc
:= First
(Component_Associations
(Aggr
));
2021 while Present
(Assoc
) loop
2022 Choice
:= First
(Choices
(Assoc
));
2024 if Present
(Next
(Choice
)) then
2026 ("multiple choice not allowed here", Next
(Choice
));
2030 if Nkind
(Choice
) = N_Others_Choice
then
2031 Error_Msg_N
("others choice not allowed here", Choice
);
2034 elsif Nkind
(Choice
) = N_Range
then
2035 -- ??? should allow zero/one element range here
2036 Error_Msg_N
("range not allowed here", Choice
);
2040 Analyze_And_Resolve
(Choice
, Enumtype
);
2042 if Is_Entity_Name
(Choice
)
2043 and then Is_Type
(Entity
(Choice
))
2045 Error_Msg_N
("subtype name not allowed here", Choice
);
2047 -- ??? should allow static subtype with zero/one entry
2049 elsif Etype
(Choice
) = Base_Type
(Enumtype
) then
2050 if not Is_Static_Expression
(Choice
) then
2051 Flag_Non_Static_Expr
2052 ("non-static expression used for choice!", Choice
);
2056 Elit
:= Expr_Value_E
(Choice
);
2058 if Present
(Enumeration_Rep_Expr
(Elit
)) then
2059 Error_Msg_Sloc
:= Sloc
(Enumeration_Rep_Expr
(Elit
));
2061 ("representation for& previously given#",
2066 Set_Enumeration_Rep_Expr
(Elit
, Choice
);
2068 Expr
:= Expression
(Assoc
);
2069 Val
:= Static_Integer
(Expr
);
2071 if Val
= No_Uint
then
2074 elsif Val
< Lo
or else Hi
< Val
then
2075 Error_Msg_N
("value outside permitted range", Expr
);
2079 Set_Enumeration_Rep
(Elit
, Val
);
2088 -- Aggregate is fully processed. Now we check that a full set of
2089 -- representations was given, and that they are in range and in order.
2090 -- These checks are only done if no other errors occurred.
2096 Elit
:= First_Literal
(Enumtype
);
2097 while Present
(Elit
) loop
2098 if No
(Enumeration_Rep_Expr
(Elit
)) then
2099 Error_Msg_NE
("missing representation for&!", N
, Elit
);
2102 Val
:= Enumeration_Rep
(Elit
);
2104 if Min
= No_Uint
then
2108 if Val
/= No_Uint
then
2109 if Max
/= No_Uint
and then Val
<= Max
then
2111 ("enumeration value for& not ordered!",
2112 Enumeration_Rep_Expr
(Elit
), Elit
);
2118 -- If there is at least one literal whose representation
2119 -- is not equal to the Pos value, then note that this
2120 -- enumeration type has a non-standard representation.
2122 if Val
/= Enumeration_Pos
(Elit
) then
2123 Set_Has_Non_Standard_Rep
(Base_Type
(Enumtype
));
2130 -- Now set proper size information
2133 Minsize
: Uint
:= UI_From_Int
(Minimum_Size
(Enumtype
));
2136 if Has_Size_Clause
(Enumtype
) then
2137 if Esize
(Enumtype
) >= Minsize
then
2142 UI_From_Int
(Minimum_Size
(Enumtype
, Biased
=> True));
2144 if Esize
(Enumtype
) < Minsize
then
2145 Error_Msg_N
("previously given size is too small", N
);
2148 Set_Has_Biased_Representation
(Enumtype
);
2153 Set_RM_Size
(Enumtype
, Minsize
);
2154 Set_Enum_Esize
(Enumtype
);
2157 Set_RM_Size
(Base_Type
(Enumtype
), RM_Size
(Enumtype
));
2158 Set_Esize
(Base_Type
(Enumtype
), Esize
(Enumtype
));
2159 Set_Alignment
(Base_Type
(Enumtype
), Alignment
(Enumtype
));
2163 -- We repeat the too late test in case it froze itself!
2165 if Rep_Item_Too_Late
(Enumtype
, N
) then
2168 end Analyze_Enumeration_Representation_Clause
;
2170 ----------------------------
2171 -- Analyze_Free_Statement --
2172 ----------------------------
2174 procedure Analyze_Free_Statement
(N
: Node_Id
) is
2176 Analyze
(Expression
(N
));
2177 end Analyze_Free_Statement
;
2179 ------------------------------------------
2180 -- Analyze_Record_Representation_Clause --
2181 ------------------------------------------
2183 procedure Analyze_Record_Representation_Clause
(N
: Node_Id
) is
2184 Loc
: constant Source_Ptr
:= Sloc
(N
);
2185 Ident
: constant Node_Id
:= Identifier
(N
);
2186 Rectype
: Entity_Id
;
2192 Hbit
: Uint
:= Uint_0
;
2197 Max_Bit_So_Far
: Uint
;
2198 -- Records the maximum bit position so far. If all field positions
2199 -- are monotonically increasing, then we can skip the circuit for
2200 -- checking for overlap, since no overlap is possible.
2202 Overlap_Check_Required
: Boolean;
2203 -- Used to keep track of whether or not an overlap check is required
2205 Ccount
: Natural := 0;
2206 -- Number of component clauses in record rep clause
2208 CR_Pragma
: Node_Id
:= Empty
;
2209 -- Points to N_Pragma node if Complete_Representation pragma present
2212 if Ignore_Rep_Clauses
then
2217 Rectype
:= Entity
(Ident
);
2219 if Rectype
= Any_Type
2220 or else Rep_Item_Too_Early
(Rectype
, N
)
2224 Rectype
:= Underlying_Type
(Rectype
);
2227 -- First some basic error checks
2229 if not Is_Record_Type
(Rectype
) then
2231 ("record type required, found}", Ident
, First_Subtype
(Rectype
));
2234 elsif Is_Unchecked_Union
(Rectype
) then
2236 ("record rep clause not allowed for Unchecked_Union", N
);
2238 elsif Scope
(Rectype
) /= Current_Scope
then
2239 Error_Msg_N
("type must be declared in this scope", N
);
2242 elsif not Is_First_Subtype
(Rectype
) then
2243 Error_Msg_N
("cannot give record rep clause for subtype", N
);
2246 elsif Has_Record_Rep_Clause
(Rectype
) then
2247 Error_Msg_N
("duplicate record rep clause ignored", N
);
2250 elsif Rep_Item_Too_Late
(Rectype
, N
) then
2254 if Present
(Mod_Clause
(N
)) then
2256 Loc
: constant Source_Ptr
:= Sloc
(N
);
2257 M
: constant Node_Id
:= Mod_Clause
(N
);
2258 P
: constant List_Id
:= Pragmas_Before
(M
);
2262 pragma Warnings
(Off
, Mod_Val
);
2265 Check_Restriction
(No_Obsolescent_Features
, Mod_Clause
(N
));
2267 if Warn_On_Obsolescent_Feature
then
2269 ("mod clause is an obsolescent feature (RM J.8)?", N
);
2271 ("\use alignment attribute definition clause instead?", N
);
2278 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2279 -- the Mod clause into an alignment clause anyway, so that the
2280 -- back-end can compute and back-annotate properly the size and
2281 -- alignment of types that may include this record.
2283 -- This seems dubious, this destroys the source tree in a manner
2284 -- not detectable by ASIS ???
2286 if Operating_Mode
= Check_Semantics
2290 Make_Attribute_Definition_Clause
(Loc
,
2291 Name
=> New_Reference_To
(Base_Type
(Rectype
), Loc
),
2292 Chars
=> Name_Alignment
,
2293 Expression
=> Relocate_Node
(Expression
(M
)));
2295 Set_From_At_Mod
(AtM_Nod
);
2296 Insert_After
(N
, AtM_Nod
);
2297 Mod_Val
:= Get_Alignment_Value
(Expression
(AtM_Nod
));
2298 Set_Mod_Clause
(N
, Empty
);
2301 -- Get the alignment value to perform error checking
2303 Mod_Val
:= Get_Alignment_Value
(Expression
(M
));
2309 -- For untagged types, clear any existing component clauses for the
2310 -- type. If the type is derived, this is what allows us to override
2311 -- a rep clause for the parent. For type extensions, the representation
2312 -- of the inherited components is inherited, so we want to keep previous
2313 -- component clauses for completeness.
2315 if not Is_Tagged_Type
(Rectype
) then
2316 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2317 while Present
(Comp
) loop
2318 Set_Component_Clause
(Comp
, Empty
);
2319 Next_Component_Or_Discriminant
(Comp
);
2323 -- All done if no component clauses
2325 CC
:= First
(Component_Clauses
(N
));
2331 -- If a tag is present, then create a component clause that places it
2332 -- at the start of the record (otherwise gigi may place it after other
2333 -- fields that have rep clauses).
2335 Fent
:= First_Entity
(Rectype
);
2337 if Nkind
(Fent
) = N_Defining_Identifier
2338 and then Chars
(Fent
) = Name_uTag
2340 Set_Component_Bit_Offset
(Fent
, Uint_0
);
2341 Set_Normalized_Position
(Fent
, Uint_0
);
2342 Set_Normalized_First_Bit
(Fent
, Uint_0
);
2343 Set_Normalized_Position_Max
(Fent
, Uint_0
);
2344 Init_Esize
(Fent
, System_Address_Size
);
2346 Set_Component_Clause
(Fent
,
2347 Make_Component_Clause
(Loc
,
2349 Make_Identifier
(Loc
,
2350 Chars
=> Name_uTag
),
2353 Make_Integer_Literal
(Loc
,
2357 Make_Integer_Literal
(Loc
,
2361 Make_Integer_Literal
(Loc
,
2362 UI_From_Int
(System_Address_Size
))));
2364 Ccount
:= Ccount
+ 1;
2367 -- A representation like this applies to the base type
2369 Set_Has_Record_Rep_Clause
(Base_Type
(Rectype
));
2370 Set_Has_Non_Standard_Rep
(Base_Type
(Rectype
));
2371 Set_Has_Specified_Layout
(Base_Type
(Rectype
));
2373 Max_Bit_So_Far
:= Uint_Minus_1
;
2374 Overlap_Check_Required
:= False;
2376 -- Process the component clauses
2378 while Present
(CC
) loop
2382 if Nkind
(CC
) = N_Pragma
then
2385 -- The only pragma of interest is Complete_Representation
2387 if Pragma_Name
(CC
) = Name_Complete_Representation
then
2391 -- Processing for real component clause
2394 Ccount
:= Ccount
+ 1;
2395 Posit
:= Static_Integer
(Position
(CC
));
2396 Fbit
:= Static_Integer
(First_Bit
(CC
));
2397 Lbit
:= Static_Integer
(Last_Bit
(CC
));
2400 and then Fbit
/= No_Uint
2401 and then Lbit
/= No_Uint
2405 ("position cannot be negative", Position
(CC
));
2409 ("first bit cannot be negative", First_Bit
(CC
));
2411 -- The Last_Bit specified in a component clause must not be
2412 -- less than the First_Bit minus one (RM-13.5.1(10)).
2414 elsif Lbit
< Fbit
- 1 then
2416 ("last bit cannot be less than first bit minus one",
2419 -- Values look OK, so find the corresponding record component
2420 -- Even though the syntax allows an attribute reference for
2421 -- implementation-defined components, GNAT does not allow the
2422 -- tag to get an explicit position.
2424 elsif Nkind
(Component_Name
(CC
)) = N_Attribute_Reference
then
2425 if Attribute_Name
(Component_Name
(CC
)) = Name_Tag
then
2426 Error_Msg_N
("position of tag cannot be specified", CC
);
2428 Error_Msg_N
("illegal component name", CC
);
2432 Comp
:= First_Entity
(Rectype
);
2433 while Present
(Comp
) loop
2434 exit when Chars
(Comp
) = Chars
(Component_Name
(CC
));
2440 -- Maybe component of base type that is absent from
2441 -- statically constrained first subtype.
2443 Comp
:= First_Entity
(Base_Type
(Rectype
));
2444 while Present
(Comp
) loop
2445 exit when Chars
(Comp
) = Chars
(Component_Name
(CC
));
2452 ("component clause is for non-existent field", CC
);
2454 elsif Present
(Component_Clause
(Comp
)) then
2456 -- Diagnose duplicate rep clause, or check consistency
2457 -- if this is an inherited component. In a double fault,
2458 -- there may be a duplicate inconsistent clause for an
2459 -- inherited component.
2461 if Scope
(Original_Record_Component
(Comp
)) = Rectype
2462 or else Parent
(Component_Clause
(Comp
)) = N
2464 Error_Msg_Sloc
:= Sloc
(Component_Clause
(Comp
));
2465 Error_Msg_N
("component clause previously given#", CC
);
2469 Rep1
: constant Node_Id
:= Component_Clause
(Comp
);
2471 if Intval
(Position
(Rep1
)) /=
2472 Intval
(Position
(CC
))
2473 or else Intval
(First_Bit
(Rep1
)) /=
2474 Intval
(First_Bit
(CC
))
2475 or else Intval
(Last_Bit
(Rep1
)) /=
2476 Intval
(Last_Bit
(CC
))
2478 Error_Msg_N
("component clause inconsistent "
2479 & "with representation of ancestor", CC
);
2480 elsif Warn_On_Redundant_Constructs
then
2481 Error_Msg_N
("?redundant component clause "
2482 & "for inherited component!", CC
);
2488 -- Make reference for field in record rep clause and set
2489 -- appropriate entity field in the field identifier.
2492 (Comp
, Component_Name
(CC
), Set_Ref
=> False);
2493 Set_Entity
(Component_Name
(CC
), Comp
);
2495 -- Update Fbit and Lbit to the actual bit number
2497 Fbit
:= Fbit
+ UI_From_Int
(SSU
) * Posit
;
2498 Lbit
:= Lbit
+ UI_From_Int
(SSU
) * Posit
;
2500 if Fbit
<= Max_Bit_So_Far
then
2501 Overlap_Check_Required
:= True;
2503 Max_Bit_So_Far
:= Lbit
;
2506 if Has_Size_Clause
(Rectype
)
2507 and then Esize
(Rectype
) <= Lbit
2510 ("bit number out of range of specified size",
2513 Set_Component_Clause
(Comp
, CC
);
2514 Set_Component_Bit_Offset
(Comp
, Fbit
);
2515 Set_Esize
(Comp
, 1 + (Lbit
- Fbit
));
2516 Set_Normalized_First_Bit
(Comp
, Fbit
mod SSU
);
2517 Set_Normalized_Position
(Comp
, Fbit
/ SSU
);
2519 Set_Normalized_Position_Max
2520 (Fent
, Normalized_Position
(Fent
));
2522 if Is_Tagged_Type
(Rectype
)
2523 and then Fbit
< System_Address_Size
2526 ("component overlaps tag field of&",
2530 -- This information is also set in the corresponding
2531 -- component of the base type, found by accessing the
2532 -- Original_Record_Component link if it is present.
2534 Ocomp
:= Original_Record_Component
(Comp
);
2541 (Component_Name
(CC
),
2546 Set_Has_Biased_Representation
(Comp
, Biased
);
2548 if Biased
and Warn_On_Biased_Representation
then
2550 ("?component clause forces biased "
2551 & "representation", CC
);
2554 if Present
(Ocomp
) then
2555 Set_Component_Clause
(Ocomp
, CC
);
2556 Set_Component_Bit_Offset
(Ocomp
, Fbit
);
2557 Set_Normalized_First_Bit
(Ocomp
, Fbit
mod SSU
);
2558 Set_Normalized_Position
(Ocomp
, Fbit
/ SSU
);
2559 Set_Esize
(Ocomp
, 1 + (Lbit
- Fbit
));
2561 Set_Normalized_Position_Max
2562 (Ocomp
, Normalized_Position
(Ocomp
));
2564 Set_Has_Biased_Representation
2565 (Ocomp
, Has_Biased_Representation
(Comp
));
2568 if Esize
(Comp
) < 0 then
2569 Error_Msg_N
("component size is negative", CC
);
2580 -- Now that we have processed all the component clauses, check for
2581 -- overlap. We have to leave this till last, since the components can
2582 -- appear in any arbitrary order in the representation clause.
2584 -- We do not need this check if all specified ranges were monotonic,
2585 -- as recorded by Overlap_Check_Required being False at this stage.
2587 -- This first section checks if there are any overlapping entries at
2588 -- all. It does this by sorting all entries and then seeing if there are
2589 -- any overlaps. If there are none, then that is decisive, but if there
2590 -- are overlaps, they may still be OK (they may result from fields in
2591 -- different variants).
2593 if Overlap_Check_Required
then
2594 Overlap_Check1
: declare
2596 OC_Fbit
: array (0 .. Ccount
) of Uint
;
2597 -- First-bit values for component clauses, the value is the offset
2598 -- of the first bit of the field from start of record. The zero
2599 -- entry is for use in sorting.
2601 OC_Lbit
: array (0 .. Ccount
) of Uint
;
2602 -- Last-bit values for component clauses, the value is the offset
2603 -- of the last bit of the field from start of record. The zero
2604 -- entry is for use in sorting.
2606 OC_Count
: Natural := 0;
2607 -- Count of entries in OC_Fbit and OC_Lbit
2609 function OC_Lt
(Op1
, Op2
: Natural) return Boolean;
2610 -- Compare routine for Sort
2612 procedure OC_Move
(From
: Natural; To
: Natural);
2613 -- Move routine for Sort
2615 package Sorting
is new GNAT
.Heap_Sort_G
(OC_Move
, OC_Lt
);
2617 function OC_Lt
(Op1
, Op2
: Natural) return Boolean is
2619 return OC_Fbit
(Op1
) < OC_Fbit
(Op2
);
2622 procedure OC_Move
(From
: Natural; To
: Natural) is
2624 OC_Fbit
(To
) := OC_Fbit
(From
);
2625 OC_Lbit
(To
) := OC_Lbit
(From
);
2629 CC
:= First
(Component_Clauses
(N
));
2630 while Present
(CC
) loop
2631 if Nkind
(CC
) /= N_Pragma
then
2632 Posit
:= Static_Integer
(Position
(CC
));
2633 Fbit
:= Static_Integer
(First_Bit
(CC
));
2634 Lbit
:= Static_Integer
(Last_Bit
(CC
));
2637 and then Fbit
/= No_Uint
2638 and then Lbit
/= No_Uint
2640 OC_Count
:= OC_Count
+ 1;
2641 Posit
:= Posit
* SSU
;
2642 OC_Fbit
(OC_Count
) := Fbit
+ Posit
;
2643 OC_Lbit
(OC_Count
) := Lbit
+ Posit
;
2650 Sorting
.Sort
(OC_Count
);
2652 Overlap_Check_Required
:= False;
2653 for J
in 1 .. OC_Count
- 1 loop
2654 if OC_Lbit
(J
) >= OC_Fbit
(J
+ 1) then
2655 Overlap_Check_Required
:= True;
2662 -- If Overlap_Check_Required is still True, then we have to do the full
2663 -- scale overlap check, since we have at least two fields that do
2664 -- overlap, and we need to know if that is OK since they are in
2665 -- different variant, or whether we have a definite problem.
2667 if Overlap_Check_Required
then
2668 Overlap_Check2
: declare
2669 C1_Ent
, C2_Ent
: Entity_Id
;
2670 -- Entities of components being checked for overlap
2673 -- Component_List node whose Component_Items are being checked
2676 -- Component declaration for component being checked
2679 C1_Ent
:= First_Entity
(Base_Type
(Rectype
));
2681 -- Loop through all components in record. For each component check
2682 -- for overlap with any of the preceding elements on the component
2683 -- list containing the component and also, if the component is in
2684 -- a variant, check against components outside the case structure.
2685 -- This latter test is repeated recursively up the variant tree.
2687 Main_Component_Loop
: while Present
(C1_Ent
) loop
2688 if Ekind
(C1_Ent
) /= E_Component
2689 and then Ekind
(C1_Ent
) /= E_Discriminant
2691 goto Continue_Main_Component_Loop
;
2694 -- Skip overlap check if entity has no declaration node. This
2695 -- happens with discriminants in constrained derived types.
2696 -- Probably we are missing some checks as a result, but that
2697 -- does not seem terribly serious ???
2699 if No
(Declaration_Node
(C1_Ent
)) then
2700 goto Continue_Main_Component_Loop
;
2703 Clist
:= Parent
(List_Containing
(Declaration_Node
(C1_Ent
)));
2705 -- Loop through component lists that need checking. Check the
2706 -- current component list and all lists in variants above us.
2708 Component_List_Loop
: loop
2710 -- If derived type definition, go to full declaration
2711 -- If at outer level, check discriminants if there are any.
2713 if Nkind
(Clist
) = N_Derived_Type_Definition
then
2714 Clist
:= Parent
(Clist
);
2717 -- Outer level of record definition, check discriminants
2719 if Nkind_In
(Clist
, N_Full_Type_Declaration
,
2720 N_Private_Type_Declaration
)
2722 if Has_Discriminants
(Defining_Identifier
(Clist
)) then
2724 First_Discriminant
(Defining_Identifier
(Clist
));
2726 while Present
(C2_Ent
) loop
2727 exit when C1_Ent
= C2_Ent
;
2728 Check_Component_Overlap
(C1_Ent
, C2_Ent
);
2729 Next_Discriminant
(C2_Ent
);
2733 -- Record extension case
2735 elsif Nkind
(Clist
) = N_Derived_Type_Definition
then
2738 -- Otherwise check one component list
2741 Citem
:= First
(Component_Items
(Clist
));
2743 while Present
(Citem
) loop
2744 if Nkind
(Citem
) = N_Component_Declaration
then
2745 C2_Ent
:= Defining_Identifier
(Citem
);
2746 exit when C1_Ent
= C2_Ent
;
2747 Check_Component_Overlap
(C1_Ent
, C2_Ent
);
2754 -- Check for variants above us (the parent of the Clist can
2755 -- be a variant, in which case its parent is a variant part,
2756 -- and the parent of the variant part is a component list
2757 -- whose components must all be checked against the current
2758 -- component for overlap).
2760 if Nkind
(Parent
(Clist
)) = N_Variant
then
2761 Clist
:= Parent
(Parent
(Parent
(Clist
)));
2763 -- Check for possible discriminant part in record, this is
2764 -- treated essentially as another level in the recursion.
2765 -- For this case the parent of the component list is the
2766 -- record definition, and its parent is the full type
2767 -- declaration containing the discriminant specifications.
2769 elsif Nkind
(Parent
(Clist
)) = N_Record_Definition
then
2770 Clist
:= Parent
(Parent
((Clist
)));
2772 -- If neither of these two cases, we are at the top of
2776 exit Component_List_Loop
;
2778 end loop Component_List_Loop
;
2780 <<Continue_Main_Component_Loop
>>
2781 Next_Entity
(C1_Ent
);
2783 end loop Main_Component_Loop
;
2787 -- For records that have component clauses for all components, and whose
2788 -- size is less than or equal to 32, we need to know the size in the
2789 -- front end to activate possible packed array processing where the
2790 -- component type is a record.
2792 -- At this stage Hbit + 1 represents the first unused bit from all the
2793 -- component clauses processed, so if the component clauses are
2794 -- complete, then this is the length of the record.
2796 -- For records longer than System.Storage_Unit, and for those where not
2797 -- all components have component clauses, the back end determines the
2798 -- length (it may for example be appropriate to round up the size
2799 -- to some convenient boundary, based on alignment considerations, etc).
2801 if Unknown_RM_Size
(Rectype
) and then Hbit
+ 1 <= 32 then
2803 -- Nothing to do if at least one component has no component clause
2805 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2806 while Present
(Comp
) loop
2807 exit when No
(Component_Clause
(Comp
));
2808 Next_Component_Or_Discriminant
(Comp
);
2811 -- If we fall out of loop, all components have component clauses
2812 -- and so we can set the size to the maximum value.
2815 Set_RM_Size
(Rectype
, Hbit
+ 1);
2819 -- Check missing components if Complete_Representation pragma appeared
2821 if Present
(CR_Pragma
) then
2822 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2823 while Present
(Comp
) loop
2824 if No
(Component_Clause
(Comp
)) then
2826 ("missing component clause for &", CR_Pragma
, Comp
);
2829 Next_Component_Or_Discriminant
(Comp
);
2832 -- If no Complete_Representation pragma, warn if missing components
2834 elsif Warn_On_Unrepped_Components
then
2836 Num_Repped_Components
: Nat
:= 0;
2837 Num_Unrepped_Components
: Nat
:= 0;
2840 -- First count number of repped and unrepped components
2842 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2843 while Present
(Comp
) loop
2844 if Present
(Component_Clause
(Comp
)) then
2845 Num_Repped_Components
:= Num_Repped_Components
+ 1;
2847 Num_Unrepped_Components
:= Num_Unrepped_Components
+ 1;
2850 Next_Component_Or_Discriminant
(Comp
);
2853 -- We are only interested in the case where there is at least one
2854 -- unrepped component, and at least half the components have rep
2855 -- clauses. We figure that if less than half have them, then the
2856 -- partial rep clause is really intentional. If the component
2857 -- type has no underlying type set at this point (as for a generic
2858 -- formal type), we don't know enough to give a warning on the
2861 if Num_Unrepped_Components
> 0
2862 and then Num_Unrepped_Components
< Num_Repped_Components
2864 Comp
:= First_Component_Or_Discriminant
(Rectype
);
2865 while Present
(Comp
) loop
2866 if No
(Component_Clause
(Comp
))
2867 and then Comes_From_Source
(Comp
)
2868 and then Present
(Underlying_Type
(Etype
(Comp
)))
2869 and then (Is_Scalar_Type
(Underlying_Type
(Etype
(Comp
)))
2870 or else Size_Known_At_Compile_Time
2871 (Underlying_Type
(Etype
(Comp
))))
2872 and then not Has_Warnings_Off
(Rectype
)
2874 Error_Msg_Sloc
:= Sloc
(Comp
);
2876 ("?no component clause given for & declared #",
2880 Next_Component_Or_Discriminant
(Comp
);
2885 end Analyze_Record_Representation_Clause
;
2887 -----------------------------
2888 -- Check_Component_Overlap --
2889 -----------------------------
2891 procedure Check_Component_Overlap
(C1_Ent
, C2_Ent
: Entity_Id
) is
2893 if Present
(Component_Clause
(C1_Ent
))
2894 and then Present
(Component_Clause
(C2_Ent
))
2896 -- Exclude odd case where we have two tag fields in the same record,
2897 -- both at location zero. This seems a bit strange, but it seems to
2898 -- happen in some circumstances ???
2900 if Chars
(C1_Ent
) = Name_uTag
2901 and then Chars
(C2_Ent
) = Name_uTag
2906 -- Here we check if the two fields overlap
2909 S1
: constant Uint
:= Component_Bit_Offset
(C1_Ent
);
2910 S2
: constant Uint
:= Component_Bit_Offset
(C2_Ent
);
2911 E1
: constant Uint
:= S1
+ Esize
(C1_Ent
);
2912 E2
: constant Uint
:= S2
+ Esize
(C2_Ent
);
2915 if E2
<= S1
or else E1
<= S2
then
2919 Component_Name
(Component_Clause
(C2_Ent
));
2920 Error_Msg_Sloc
:= Sloc
(Error_Msg_Node_2
);
2922 Component_Name
(Component_Clause
(C1_Ent
));
2924 ("component& overlaps & #",
2925 Component_Name
(Component_Clause
(C1_Ent
)));
2929 end Check_Component_Overlap
;
2931 -----------------------------------
2932 -- Check_Constant_Address_Clause --
2933 -----------------------------------
2935 procedure Check_Constant_Address_Clause
2939 procedure Check_At_Constant_Address
(Nod
: Node_Id
);
2940 -- Checks that the given node N represents a name whose 'Address is
2941 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2942 -- address value is the same at the point of declaration of U_Ent and at
2943 -- the time of elaboration of the address clause.
2945 procedure Check_Expr_Constants
(Nod
: Node_Id
);
2946 -- Checks that Nod meets the requirements for a constant address clause
2947 -- in the sense of the enclosing procedure.
2949 procedure Check_List_Constants
(Lst
: List_Id
);
2950 -- Check that all elements of list Lst meet the requirements for a
2951 -- constant address clause in the sense of the enclosing procedure.
2953 -------------------------------
2954 -- Check_At_Constant_Address --
2955 -------------------------------
2957 procedure Check_At_Constant_Address
(Nod
: Node_Id
) is
2959 if Is_Entity_Name
(Nod
) then
2960 if Present
(Address_Clause
(Entity
((Nod
)))) then
2962 ("invalid address clause for initialized object &!",
2965 ("address for& cannot" &
2966 " depend on another address clause! (RM 13.1(22))!",
2969 elsif In_Same_Source_Unit
(Entity
(Nod
), U_Ent
)
2970 and then Sloc
(U_Ent
) < Sloc
(Entity
(Nod
))
2973 ("invalid address clause for initialized object &!",
2975 Error_Msg_Node_2
:= U_Ent
;
2977 ("\& must be defined before & (RM 13.1(22))!",
2981 elsif Nkind
(Nod
) = N_Selected_Component
then
2983 T
: constant Entity_Id
:= Etype
(Prefix
(Nod
));
2986 if (Is_Record_Type
(T
)
2987 and then Has_Discriminants
(T
))
2990 and then Is_Record_Type
(Designated_Type
(T
))
2991 and then Has_Discriminants
(Designated_Type
(T
)))
2994 ("invalid address clause for initialized object &!",
2997 ("\address cannot depend on component" &
2998 " of discriminated record (RM 13.1(22))!",
3001 Check_At_Constant_Address
(Prefix
(Nod
));
3005 elsif Nkind
(Nod
) = N_Indexed_Component
then
3006 Check_At_Constant_Address
(Prefix
(Nod
));
3007 Check_List_Constants
(Expressions
(Nod
));
3010 Check_Expr_Constants
(Nod
);
3012 end Check_At_Constant_Address
;
3014 --------------------------
3015 -- Check_Expr_Constants --
3016 --------------------------
3018 procedure Check_Expr_Constants
(Nod
: Node_Id
) is
3019 Loc_U_Ent
: constant Source_Ptr
:= Sloc
(U_Ent
);
3020 Ent
: Entity_Id
:= Empty
;
3023 if Nkind
(Nod
) in N_Has_Etype
3024 and then Etype
(Nod
) = Any_Type
3030 when N_Empty | N_Error
=>
3033 when N_Identifier | N_Expanded_Name
=>
3034 Ent
:= Entity
(Nod
);
3036 -- We need to look at the original node if it is different
3037 -- from the node, since we may have rewritten things and
3038 -- substituted an identifier representing the rewrite.
3040 if Original_Node
(Nod
) /= Nod
then
3041 Check_Expr_Constants
(Original_Node
(Nod
));
3043 -- If the node is an object declaration without initial
3044 -- value, some code has been expanded, and the expression
3045 -- is not constant, even if the constituents might be
3046 -- acceptable, as in A'Address + offset.
3048 if Ekind
(Ent
) = E_Variable
3050 Nkind
(Declaration_Node
(Ent
)) = N_Object_Declaration
3052 No
(Expression
(Declaration_Node
(Ent
)))
3055 ("invalid address clause for initialized object &!",
3058 -- If entity is constant, it may be the result of expanding
3059 -- a check. We must verify that its declaration appears
3060 -- before the object in question, else we also reject the
3063 elsif Ekind
(Ent
) = E_Constant
3064 and then In_Same_Source_Unit
(Ent
, U_Ent
)
3065 and then Sloc
(Ent
) > Loc_U_Ent
3068 ("invalid address clause for initialized object &!",
3075 -- Otherwise look at the identifier and see if it is OK
3077 if Ekind
(Ent
) = E_Named_Integer
3079 Ekind
(Ent
) = E_Named_Real
3086 Ekind
(Ent
) = E_Constant
3088 Ekind
(Ent
) = E_In_Parameter
3090 -- This is the case where we must have Ent defined before
3091 -- U_Ent. Clearly if they are in different units this
3092 -- requirement is met since the unit containing Ent is
3093 -- already processed.
3095 if not In_Same_Source_Unit
(Ent
, U_Ent
) then
3098 -- Otherwise location of Ent must be before the location
3099 -- of U_Ent, that's what prior defined means.
3101 elsif Sloc
(Ent
) < Loc_U_Ent
then
3106 ("invalid address clause for initialized object &!",
3108 Error_Msg_Node_2
:= U_Ent
;
3110 ("\& must be defined before & (RM 13.1(22))!",
3114 elsif Nkind
(Original_Node
(Nod
)) = N_Function_Call
then
3115 Check_Expr_Constants
(Original_Node
(Nod
));
3119 ("invalid address clause for initialized object &!",
3122 if Comes_From_Source
(Ent
) then
3124 ("\reference to variable& not allowed"
3125 & " (RM 13.1(22))!", Nod
, Ent
);
3128 ("non-static expression not allowed"
3129 & " (RM 13.1(22))!", Nod
);
3133 when N_Integer_Literal
=>
3135 -- If this is a rewritten unchecked conversion, in a system
3136 -- where Address is an integer type, always use the base type
3137 -- for a literal value. This is user-friendly and prevents
3138 -- order-of-elaboration issues with instances of unchecked
3141 if Nkind
(Original_Node
(Nod
)) = N_Function_Call
then
3142 Set_Etype
(Nod
, Base_Type
(Etype
(Nod
)));
3145 when N_Real_Literal |
3147 N_Character_Literal
=>
3151 Check_Expr_Constants
(Low_Bound
(Nod
));
3152 Check_Expr_Constants
(High_Bound
(Nod
));
3154 when N_Explicit_Dereference
=>
3155 Check_Expr_Constants
(Prefix
(Nod
));
3157 when N_Indexed_Component
=>
3158 Check_Expr_Constants
(Prefix
(Nod
));
3159 Check_List_Constants
(Expressions
(Nod
));
3162 Check_Expr_Constants
(Prefix
(Nod
));
3163 Check_Expr_Constants
(Discrete_Range
(Nod
));
3165 when N_Selected_Component
=>
3166 Check_Expr_Constants
(Prefix
(Nod
));
3168 when N_Attribute_Reference
=>
3169 if Attribute_Name
(Nod
) = Name_Address
3171 Attribute_Name
(Nod
) = Name_Access
3173 Attribute_Name
(Nod
) = Name_Unchecked_Access
3175 Attribute_Name
(Nod
) = Name_Unrestricted_Access
3177 Check_At_Constant_Address
(Prefix
(Nod
));
3180 Check_Expr_Constants
(Prefix
(Nod
));
3181 Check_List_Constants
(Expressions
(Nod
));
3185 Check_List_Constants
(Component_Associations
(Nod
));
3186 Check_List_Constants
(Expressions
(Nod
));
3188 when N_Component_Association
=>
3189 Check_Expr_Constants
(Expression
(Nod
));
3191 when N_Extension_Aggregate
=>
3192 Check_Expr_Constants
(Ancestor_Part
(Nod
));
3193 Check_List_Constants
(Component_Associations
(Nod
));
3194 Check_List_Constants
(Expressions
(Nod
));
3199 when N_Binary_Op | N_Short_Circuit | N_Membership_Test
=>
3200 Check_Expr_Constants
(Left_Opnd
(Nod
));
3201 Check_Expr_Constants
(Right_Opnd
(Nod
));
3204 Check_Expr_Constants
(Right_Opnd
(Nod
));
3206 when N_Type_Conversion |
3207 N_Qualified_Expression |
3209 Check_Expr_Constants
(Expression
(Nod
));
3211 when N_Unchecked_Type_Conversion
=>
3212 Check_Expr_Constants
(Expression
(Nod
));
3214 -- If this is a rewritten unchecked conversion, subtypes in
3215 -- this node are those created within the instance. To avoid
3216 -- order of elaboration issues, replace them with their base
3217 -- types. Note that address clauses can cause order of
3218 -- elaboration problems because they are elaborated by the
3219 -- back-end at the point of definition, and may mention
3220 -- entities declared in between (as long as everything is
3221 -- static). It is user-friendly to allow unchecked conversions
3224 if Nkind
(Original_Node
(Nod
)) = N_Function_Call
then
3225 Set_Etype
(Expression
(Nod
),
3226 Base_Type
(Etype
(Expression
(Nod
))));
3227 Set_Etype
(Nod
, Base_Type
(Etype
(Nod
)));
3230 when N_Function_Call
=>
3231 if not Is_Pure
(Entity
(Name
(Nod
))) then
3233 ("invalid address clause for initialized object &!",
3237 ("\function & is not pure (RM 13.1(22))!",
3238 Nod
, Entity
(Name
(Nod
)));
3241 Check_List_Constants
(Parameter_Associations
(Nod
));
3244 when N_Parameter_Association
=>
3245 Check_Expr_Constants
(Explicit_Actual_Parameter
(Nod
));
3249 ("invalid address clause for initialized object &!",
3252 ("\must be constant defined before& (RM 13.1(22))!",
3255 end Check_Expr_Constants
;
3257 --------------------------
3258 -- Check_List_Constants --
3259 --------------------------
3261 procedure Check_List_Constants
(Lst
: List_Id
) is
3265 if Present
(Lst
) then
3266 Nod1
:= First
(Lst
);
3267 while Present
(Nod1
) loop
3268 Check_Expr_Constants
(Nod1
);
3272 end Check_List_Constants
;
3274 -- Start of processing for Check_Constant_Address_Clause
3277 Check_Expr_Constants
(Expr
);
3278 end Check_Constant_Address_Clause
;
3284 procedure Check_Size
3288 Biased
: out Boolean)
3290 UT
: constant Entity_Id
:= Underlying_Type
(T
);
3296 -- Dismiss cases for generic types or types with previous errors
3299 or else UT
= Any_Type
3300 or else Is_Generic_Type
(UT
)
3301 or else Is_Generic_Type
(Root_Type
(UT
))
3305 -- Check case of bit packed array
3307 elsif Is_Array_Type
(UT
)
3308 and then Known_Static_Component_Size
(UT
)
3309 and then Is_Bit_Packed_Array
(UT
)
3317 Asiz
:= Component_Size
(UT
);
3318 Indx
:= First_Index
(UT
);
3320 Ityp
:= Etype
(Indx
);
3322 -- If non-static bound, then we are not in the business of
3323 -- trying to check the length, and indeed an error will be
3324 -- issued elsewhere, since sizes of non-static array types
3325 -- cannot be set implicitly or explicitly.
3327 if not Is_Static_Subtype
(Ityp
) then
3331 -- Otherwise accumulate next dimension
3333 Asiz
:= Asiz
* (Expr_Value
(Type_High_Bound
(Ityp
)) -
3334 Expr_Value
(Type_Low_Bound
(Ityp
)) +
3338 exit when No
(Indx
);
3344 Error_Msg_Uint_1
:= Asiz
;
3346 ("size for& too small, minimum allowed is ^", N
, T
);
3347 Set_Esize
(T
, Asiz
);
3348 Set_RM_Size
(T
, Asiz
);
3352 -- All other composite types are ignored
3354 elsif Is_Composite_Type
(UT
) then
3357 -- For fixed-point types, don't check minimum if type is not frozen,
3358 -- since we don't know all the characteristics of the type that can
3359 -- affect the size (e.g. a specified small) till freeze time.
3361 elsif Is_Fixed_Point_Type
(UT
)
3362 and then not Is_Frozen
(UT
)
3366 -- Cases for which a minimum check is required
3369 -- Ignore if specified size is correct for the type
3371 if Known_Esize
(UT
) and then Siz
= Esize
(UT
) then
3375 -- Otherwise get minimum size
3377 M
:= UI_From_Int
(Minimum_Size
(UT
));
3381 -- Size is less than minimum size, but one possibility remains
3382 -- that we can manage with the new size if we bias the type.
3384 M
:= UI_From_Int
(Minimum_Size
(UT
, Biased
=> True));
3387 Error_Msg_Uint_1
:= M
;
3389 ("size for& too small, minimum allowed is ^", N
, T
);
3399 -------------------------
3400 -- Get_Alignment_Value --
3401 -------------------------
3403 function Get_Alignment_Value
(Expr
: Node_Id
) return Uint
is
3404 Align
: constant Uint
:= Static_Integer
(Expr
);
3407 if Align
= No_Uint
then
3410 elsif Align
<= 0 then
3411 Error_Msg_N
("alignment value must be positive", Expr
);
3415 for J
in Int
range 0 .. 64 loop
3417 M
: constant Uint
:= Uint_2
** J
;
3420 exit when M
= Align
;
3424 ("alignment value must be power of 2", Expr
);
3432 end Get_Alignment_Value
;
3438 procedure Initialize
is
3440 Unchecked_Conversions
.Init
;
3443 -------------------------
3444 -- Is_Operational_Item --
3445 -------------------------
3447 function Is_Operational_Item
(N
: Node_Id
) return Boolean is
3449 if Nkind
(N
) /= N_Attribute_Definition_Clause
then
3453 Id
: constant Attribute_Id
:= Get_Attribute_Id
(Chars
(N
));
3455 return Id
= Attribute_Input
3456 or else Id
= Attribute_Output
3457 or else Id
= Attribute_Read
3458 or else Id
= Attribute_Write
3459 or else Id
= Attribute_External_Tag
;
3462 end Is_Operational_Item
;
3468 function Minimum_Size
3470 Biased
: Boolean := False) return Nat
3472 Lo
: Uint
:= No_Uint
;
3473 Hi
: Uint
:= No_Uint
;
3474 LoR
: Ureal
:= No_Ureal
;
3475 HiR
: Ureal
:= No_Ureal
;
3476 LoSet
: Boolean := False;
3477 HiSet
: Boolean := False;
3481 R_Typ
: constant Entity_Id
:= Root_Type
(T
);
3484 -- If bad type, return 0
3486 if T
= Any_Type
then
3489 -- For generic types, just return zero. There cannot be any legitimate
3490 -- need to know such a size, but this routine may be called with a
3491 -- generic type as part of normal processing.
3493 elsif Is_Generic_Type
(R_Typ
)
3494 or else R_Typ
= Any_Type
3498 -- Access types. Normally an access type cannot have a size smaller
3499 -- than the size of System.Address. The exception is on VMS, where
3500 -- we have short and long addresses, and it is possible for an access
3501 -- type to have a short address size (and thus be less than the size
3502 -- of System.Address itself). We simply skip the check for VMS, and
3503 -- leave it to the back end to do the check.
3505 elsif Is_Access_Type
(T
) then
3506 if OpenVMS_On_Target
then
3509 return System_Address_Size
;
3512 -- Floating-point types
3514 elsif Is_Floating_Point_Type
(T
) then
3515 return UI_To_Int
(Esize
(R_Typ
));
3519 elsif Is_Discrete_Type
(T
) then
3521 -- The following loop is looking for the nearest compile time known
3522 -- bounds following the ancestor subtype chain. The idea is to find
3523 -- the most restrictive known bounds information.
3527 if Ancest
= Any_Type
or else Etype
(Ancest
) = Any_Type
then
3532 if Compile_Time_Known_Value
(Type_Low_Bound
(Ancest
)) then
3533 Lo
:= Expr_Rep_Value
(Type_Low_Bound
(Ancest
));
3540 if Compile_Time_Known_Value
(Type_High_Bound
(Ancest
)) then
3541 Hi
:= Expr_Rep_Value
(Type_High_Bound
(Ancest
));
3547 Ancest
:= Ancestor_Subtype
(Ancest
);
3550 Ancest
:= Base_Type
(T
);
3552 if Is_Generic_Type
(Ancest
) then
3558 -- Fixed-point types. We can't simply use Expr_Value to get the
3559 -- Corresponding_Integer_Value values of the bounds, since these do not
3560 -- get set till the type is frozen, and this routine can be called
3561 -- before the type is frozen. Similarly the test for bounds being static
3562 -- needs to include the case where we have unanalyzed real literals for
3565 elsif Is_Fixed_Point_Type
(T
) then
3567 -- The following loop is looking for the nearest compile time known
3568 -- bounds following the ancestor subtype chain. The idea is to find
3569 -- the most restrictive known bounds information.
3573 if Ancest
= Any_Type
or else Etype
(Ancest
) = Any_Type
then
3577 -- Note: In the following two tests for LoSet and HiSet, it may
3578 -- seem redundant to test for N_Real_Literal here since normally
3579 -- one would assume that the test for the value being known at
3580 -- compile time includes this case. However, there is a glitch.
3581 -- If the real literal comes from folding a non-static expression,
3582 -- then we don't consider any non- static expression to be known
3583 -- at compile time if we are in configurable run time mode (needed
3584 -- in some cases to give a clearer definition of what is and what
3585 -- is not accepted). So the test is indeed needed. Without it, we
3586 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
3589 if Nkind
(Type_Low_Bound
(Ancest
)) = N_Real_Literal
3590 or else Compile_Time_Known_Value
(Type_Low_Bound
(Ancest
))
3592 LoR
:= Expr_Value_R
(Type_Low_Bound
(Ancest
));
3599 if Nkind
(Type_High_Bound
(Ancest
)) = N_Real_Literal
3600 or else Compile_Time_Known_Value
(Type_High_Bound
(Ancest
))
3602 HiR
:= Expr_Value_R
(Type_High_Bound
(Ancest
));
3608 Ancest
:= Ancestor_Subtype
(Ancest
);
3611 Ancest
:= Base_Type
(T
);
3613 if Is_Generic_Type
(Ancest
) then
3619 Lo
:= UR_To_Uint
(LoR
/ Small_Value
(T
));
3620 Hi
:= UR_To_Uint
(HiR
/ Small_Value
(T
));
3622 -- No other types allowed
3625 raise Program_Error
;
3628 -- Fall through with Hi and Lo set. Deal with biased case
3631 and then not Is_Fixed_Point_Type
(T
)
3632 and then not (Is_Enumeration_Type
(T
)
3633 and then Has_Non_Standard_Rep
(T
)))
3634 or else Has_Biased_Representation
(T
)
3640 -- Signed case. Note that we consider types like range 1 .. -1 to be
3641 -- signed for the purpose of computing the size, since the bounds have
3642 -- to be accommodated in the base type.
3644 if Lo
< 0 or else Hi
< 0 then
3648 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
3649 -- Note that we accommodate the case where the bounds cross. This
3650 -- can happen either because of the way the bounds are declared
3651 -- or because of the algorithm in Freeze_Fixed_Point_Type.
3665 -- If both bounds are positive, make sure that both are represen-
3666 -- table in the case where the bounds are crossed. This can happen
3667 -- either because of the way the bounds are declared, or because of
3668 -- the algorithm in Freeze_Fixed_Point_Type.
3674 -- S = size, (can accommodate 0 .. (2**size - 1))
3677 while Hi
>= Uint_2
** S
loop
3685 ---------------------------
3686 -- New_Stream_Subprogram --
3687 ---------------------------
3689 procedure New_Stream_Subprogram
3693 Nam
: TSS_Name_Type
)
3695 Loc
: constant Source_Ptr
:= Sloc
(N
);
3696 Sname
: constant Name_Id
:= Make_TSS_Name
(Base_Type
(Ent
), Nam
);
3697 Subp_Id
: Entity_Id
;
3698 Subp_Decl
: Node_Id
;
3702 Defer_Declaration
: constant Boolean :=
3703 Is_Tagged_Type
(Ent
) or else Is_Private_Type
(Ent
);
3704 -- For a tagged type, there is a declaration for each stream attribute
3705 -- at the freeze point, and we must generate only a completion of this
3706 -- declaration. We do the same for private types, because the full view
3707 -- might be tagged. Otherwise we generate a declaration at the point of
3708 -- the attribute definition clause.
3710 function Build_Spec
return Node_Id
;
3711 -- Used for declaration and renaming declaration, so that this is
3712 -- treated as a renaming_as_body.
3718 function Build_Spec
return Node_Id
is
3719 Out_P
: constant Boolean := (Nam
= TSS_Stream_Read
);
3722 T_Ref
: constant Node_Id
:= New_Reference_To
(Etyp
, Loc
);
3725 Subp_Id
:= Make_Defining_Identifier
(Loc
, Sname
);
3727 -- S : access Root_Stream_Type'Class
3729 Formals
:= New_List
(
3730 Make_Parameter_Specification
(Loc
,
3731 Defining_Identifier
=>
3732 Make_Defining_Identifier
(Loc
, Name_S
),
3734 Make_Access_Definition
(Loc
,
3737 Designated_Type
(Etype
(F
)), Loc
))));
3739 if Nam
= TSS_Stream_Input
then
3740 Spec
:= Make_Function_Specification
(Loc
,
3741 Defining_Unit_Name
=> Subp_Id
,
3742 Parameter_Specifications
=> Formals
,
3743 Result_Definition
=> T_Ref
);
3748 Make_Parameter_Specification
(Loc
,
3749 Defining_Identifier
=> Make_Defining_Identifier
(Loc
, Name_V
),
3750 Out_Present
=> Out_P
,
3751 Parameter_Type
=> T_Ref
));
3753 Spec
:= Make_Procedure_Specification
(Loc
,
3754 Defining_Unit_Name
=> Subp_Id
,
3755 Parameter_Specifications
=> Formals
);
3761 -- Start of processing for New_Stream_Subprogram
3764 F
:= First_Formal
(Subp
);
3766 if Ekind
(Subp
) = E_Procedure
then
3767 Etyp
:= Etype
(Next_Formal
(F
));
3769 Etyp
:= Etype
(Subp
);
3772 -- Prepare subprogram declaration and insert it as an action on the
3773 -- clause node. The visibility for this entity is used to test for
3774 -- visibility of the attribute definition clause (in the sense of
3775 -- 8.3(23) as amended by AI-195).
3777 if not Defer_Declaration
then
3779 Make_Subprogram_Declaration
(Loc
,
3780 Specification
=> Build_Spec
);
3782 -- For a tagged type, there is always a visible declaration for each
3783 -- stream TSS (it is a predefined primitive operation), and the
3784 -- completion of this declaration occurs at the freeze point, which is
3785 -- not always visible at places where the attribute definition clause is
3786 -- visible. So, we create a dummy entity here for the purpose of
3787 -- tracking the visibility of the attribute definition clause itself.
3791 Make_Defining_Identifier
(Loc
,
3792 Chars
=> New_External_Name
(Sname
, 'V'));
3794 Make_Object_Declaration
(Loc
,
3795 Defining_Identifier
=> Subp_Id
,
3796 Object_Definition
=> New_Occurrence_Of
(Standard_Boolean
, Loc
));
3799 Insert_Action
(N
, Subp_Decl
);
3800 Set_Entity
(N
, Subp_Id
);
3803 Make_Subprogram_Renaming_Declaration
(Loc
,
3804 Specification
=> Build_Spec
,
3805 Name
=> New_Reference_To
(Subp
, Loc
));
3807 if Defer_Declaration
then
3808 Set_TSS
(Base_Type
(Ent
), Subp_Id
);
3810 Insert_Action
(N
, Subp_Decl
);
3811 Copy_TSS
(Subp_Id
, Base_Type
(Ent
));
3813 end New_Stream_Subprogram
;
3815 ------------------------
3816 -- Rep_Item_Too_Early --
3817 ------------------------
3819 function Rep_Item_Too_Early
(T
: Entity_Id
; N
: Node_Id
) return Boolean is
3821 -- Cannot apply non-operational rep items to generic types
3823 if Is_Operational_Item
(N
) then
3827 and then Is_Generic_Type
(Root_Type
(T
))
3830 ("representation item not allowed for generic type", N
);
3834 -- Otherwise check for incomplete type
3836 if Is_Incomplete_Or_Private_Type
(T
)
3837 and then No
(Underlying_Type
(T
))
3840 ("representation item must be after full type declaration", N
);
3843 -- If the type has incomplete components, a representation clause is
3844 -- illegal but stream attributes and Convention pragmas are correct.
3846 elsif Has_Private_Component
(T
) then
3847 if Nkind
(N
) = N_Pragma
then
3851 ("representation item must appear after type is fully defined",
3858 end Rep_Item_Too_Early
;
3860 -----------------------
3861 -- Rep_Item_Too_Late --
3862 -----------------------
3864 function Rep_Item_Too_Late
3867 FOnly
: Boolean := False) return Boolean
3870 Parent_Type
: Entity_Id
;
3873 -- Output the too late message. Note that this is not considered a
3874 -- serious error, since the effect is simply that we ignore the
3875 -- representation clause in this case.
3881 procedure Too_Late
is
3883 Error_Msg_N
("|representation item appears too late!", N
);
3886 -- Start of processing for Rep_Item_Too_Late
3889 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
3890 -- types, which may be frozen if they appear in a representation clause
3891 -- for a local type.
3894 and then not From_With_Type
(T
)
3897 S
:= First_Subtype
(T
);
3899 if Present
(Freeze_Node
(S
)) then
3901 ("?no more representation items for }", Freeze_Node
(S
), S
);
3906 -- Check for case of non-tagged derived type whose parent either has
3907 -- primitive operations, or is a by reference type (RM 13.1(10)).
3911 and then Is_Derived_Type
(T
)
3912 and then not Is_Tagged_Type
(T
)
3914 Parent_Type
:= Etype
(Base_Type
(T
));
3916 if Has_Primitive_Operations
(Parent_Type
) then
3919 ("primitive operations already defined for&!", N
, Parent_Type
);
3922 elsif Is_By_Reference_Type
(Parent_Type
) then
3925 ("parent type & is a by reference type!", N
, Parent_Type
);
3930 -- No error, link item into head of chain of rep items for the entity,
3931 -- but avoid chaining if we have an overloadable entity, and the pragma
3932 -- is one that can apply to multiple overloaded entities.
3934 if Is_Overloadable
(T
)
3935 and then Nkind
(N
) = N_Pragma
3938 Pname
: constant Name_Id
:= Pragma_Name
(N
);
3940 if Pname
= Name_Convention
or else
3941 Pname
= Name_Import
or else
3942 Pname
= Name_Export
or else
3943 Pname
= Name_External
or else
3944 Pname
= Name_Interface
3951 Record_Rep_Item
(T
, N
);
3953 end Rep_Item_Too_Late
;
3955 -------------------------
3956 -- Same_Representation --
3957 -------------------------
3959 function Same_Representation
(Typ1
, Typ2
: Entity_Id
) return Boolean is
3960 T1
: constant Entity_Id
:= Underlying_Type
(Typ1
);
3961 T2
: constant Entity_Id
:= Underlying_Type
(Typ2
);
3964 -- A quick check, if base types are the same, then we definitely have
3965 -- the same representation, because the subtype specific representation
3966 -- attributes (Size and Alignment) do not affect representation from
3967 -- the point of view of this test.
3969 if Base_Type
(T1
) = Base_Type
(T2
) then
3972 elsif Is_Private_Type
(Base_Type
(T2
))
3973 and then Base_Type
(T1
) = Full_View
(Base_Type
(T2
))
3978 -- Tagged types never have differing representations
3980 if Is_Tagged_Type
(T1
) then
3984 -- Representations are definitely different if conventions differ
3986 if Convention
(T1
) /= Convention
(T2
) then
3990 -- Representations are different if component alignments differ
3992 if (Is_Record_Type
(T1
) or else Is_Array_Type
(T1
))
3994 (Is_Record_Type
(T2
) or else Is_Array_Type
(T2
))
3995 and then Component_Alignment
(T1
) /= Component_Alignment
(T2
)
4000 -- For arrays, the only real issue is component size. If we know the
4001 -- component size for both arrays, and it is the same, then that's
4002 -- good enough to know we don't have a change of representation.
4004 if Is_Array_Type
(T1
) then
4005 if Known_Component_Size
(T1
)
4006 and then Known_Component_Size
(T2
)
4007 and then Component_Size
(T1
) = Component_Size
(T2
)
4013 -- Types definitely have same representation if neither has non-standard
4014 -- representation since default representations are always consistent.
4015 -- If only one has non-standard representation, and the other does not,
4016 -- then we consider that they do not have the same representation. They
4017 -- might, but there is no way of telling early enough.
4019 if Has_Non_Standard_Rep
(T1
) then
4020 if not Has_Non_Standard_Rep
(T2
) then
4024 return not Has_Non_Standard_Rep
(T2
);
4027 -- Here the two types both have non-standard representation, and we need
4028 -- to determine if they have the same non-standard representation.
4030 -- For arrays, we simply need to test if the component sizes are the
4031 -- same. Pragma Pack is reflected in modified component sizes, so this
4032 -- check also deals with pragma Pack.
4034 if Is_Array_Type
(T1
) then
4035 return Component_Size
(T1
) = Component_Size
(T2
);
4037 -- Tagged types always have the same representation, because it is not
4038 -- possible to specify different representations for common fields.
4040 elsif Is_Tagged_Type
(T1
) then
4043 -- Case of record types
4045 elsif Is_Record_Type
(T1
) then
4047 -- Packed status must conform
4049 if Is_Packed
(T1
) /= Is_Packed
(T2
) then
4052 -- Otherwise we must check components. Typ2 maybe a constrained
4053 -- subtype with fewer components, so we compare the components
4054 -- of the base types.
4057 Record_Case
: declare
4058 CD1
, CD2
: Entity_Id
;
4060 function Same_Rep
return Boolean;
4061 -- CD1 and CD2 are either components or discriminants. This
4062 -- function tests whether the two have the same representation
4068 function Same_Rep
return Boolean is
4070 if No
(Component_Clause
(CD1
)) then
4071 return No
(Component_Clause
(CD2
));
4075 Present
(Component_Clause
(CD2
))
4077 Component_Bit_Offset
(CD1
) = Component_Bit_Offset
(CD2
)
4079 Esize
(CD1
) = Esize
(CD2
);
4083 -- Start of processing for Record_Case
4086 if Has_Discriminants
(T1
) then
4087 CD1
:= First_Discriminant
(T1
);
4088 CD2
:= First_Discriminant
(T2
);
4090 -- The number of discriminants may be different if the
4091 -- derived type has fewer (constrained by values). The
4092 -- invisible discriminants retain the representation of
4093 -- the original, so the discrepancy does not per se
4094 -- indicate a different representation.
4097 and then Present
(CD2
)
4099 if not Same_Rep
then
4102 Next_Discriminant
(CD1
);
4103 Next_Discriminant
(CD2
);
4108 CD1
:= First_Component
(Underlying_Type
(Base_Type
(T1
)));
4109 CD2
:= First_Component
(Underlying_Type
(Base_Type
(T2
)));
4111 while Present
(CD1
) loop
4112 if not Same_Rep
then
4115 Next_Component
(CD1
);
4116 Next_Component
(CD2
);
4124 -- For enumeration types, we must check each literal to see if the
4125 -- representation is the same. Note that we do not permit enumeration
4126 -- representation clauses for Character and Wide_Character, so these
4127 -- cases were already dealt with.
4129 elsif Is_Enumeration_Type
(T1
) then
4131 Enumeration_Case
: declare
4135 L1
:= First_Literal
(T1
);
4136 L2
:= First_Literal
(T2
);
4138 while Present
(L1
) loop
4139 if Enumeration_Rep
(L1
) /= Enumeration_Rep
(L2
) then
4149 end Enumeration_Case
;
4151 -- Any other types have the same representation for these purposes
4156 end Same_Representation
;
4158 --------------------
4159 -- Set_Enum_Esize --
4160 --------------------
4162 procedure Set_Enum_Esize
(T
: Entity_Id
) is
4170 -- Find the minimum standard size (8,16,32,64) that fits
4172 Lo
:= Enumeration_Rep
(Entity
(Type_Low_Bound
(T
)));
4173 Hi
:= Enumeration_Rep
(Entity
(Type_High_Bound
(T
)));
4176 if Lo
>= -Uint_2
**07 and then Hi
< Uint_2
**07 then
4177 Sz
:= Standard_Character_Size
; -- May be > 8 on some targets
4179 elsif Lo
>= -Uint_2
**15 and then Hi
< Uint_2
**15 then
4182 elsif Lo
>= -Uint_2
**31 and then Hi
< Uint_2
**31 then
4185 else pragma Assert
(Lo
>= -Uint_2
**63 and then Hi
< Uint_2
**63);
4190 if Hi
< Uint_2
**08 then
4191 Sz
:= Standard_Character_Size
; -- May be > 8 on some targets
4193 elsif Hi
< Uint_2
**16 then
4196 elsif Hi
< Uint_2
**32 then
4199 else pragma Assert
(Hi
< Uint_2
**63);
4204 -- That minimum is the proper size unless we have a foreign convention
4205 -- and the size required is 32 or less, in which case we bump the size
4206 -- up to 32. This is required for C and C++ and seems reasonable for
4207 -- all other foreign conventions.
4209 if Has_Foreign_Convention
(T
)
4210 and then Esize
(T
) < Standard_Integer_Size
4212 Init_Esize
(T
, Standard_Integer_Size
);
4218 ------------------------------
4219 -- Validate_Address_Clauses --
4220 ------------------------------
4222 procedure Validate_Address_Clauses
is
4224 for J
in Address_Clause_Checks
.First
.. Address_Clause_Checks
.Last
loop
4226 ACCR
: Address_Clause_Check_Record
4227 renames Address_Clause_Checks
.Table
(J
);
4238 -- Skip processing of this entry if warning already posted
4240 if not Address_Warning_Posted
(ACCR
.N
) then
4242 Expr
:= Original_Node
(Expression
(ACCR
.N
));
4246 X_Alignment
:= Alignment
(ACCR
.X
);
4247 Y_Alignment
:= Alignment
(ACCR
.Y
);
4249 -- Similarly obtain sizes
4251 X_Size
:= Esize
(ACCR
.X
);
4252 Y_Size
:= Esize
(ACCR
.Y
);
4254 -- Check for large object overlaying smaller one
4257 and then X_Size
> Uint_0
4258 and then X_Size
> Y_Size
4261 ("?& overlays smaller object", ACCR
.N
, ACCR
.X
);
4263 ("\?program execution may be erroneous", ACCR
.N
);
4264 Error_Msg_Uint_1
:= X_Size
;
4266 ("\?size of & is ^", ACCR
.N
, ACCR
.X
);
4267 Error_Msg_Uint_1
:= Y_Size
;
4269 ("\?size of & is ^", ACCR
.N
, ACCR
.Y
);
4271 -- Check for inadequate alignment, both of the base object
4272 -- and of the offset, if any.
4274 -- Note: we do not check the alignment if we gave a size
4275 -- warning, since it would likely be redundant.
4277 elsif Y_Alignment
/= Uint_0
4278 and then (Y_Alignment
< X_Alignment
4281 Nkind
(Expr
) = N_Attribute_Reference
4283 Attribute_Name
(Expr
) = Name_Address
4285 Has_Compatible_Alignment
4286 (ACCR
.X
, Prefix
(Expr
))
4287 /= Known_Compatible
))
4290 ("?specified address for& may be inconsistent "
4294 ("\?program execution may be erroneous (RM 13.3(27))",
4296 Error_Msg_Uint_1
:= X_Alignment
;
4298 ("\?alignment of & is ^",
4300 Error_Msg_Uint_1
:= Y_Alignment
;
4302 ("\?alignment of & is ^",
4304 if Y_Alignment
>= X_Alignment
then
4306 ("\?but offset is not multiple of alignment",
4313 end Validate_Address_Clauses
;
4315 -----------------------------------
4316 -- Validate_Unchecked_Conversion --
4317 -----------------------------------
4319 procedure Validate_Unchecked_Conversion
4321 Act_Unit
: Entity_Id
)
4328 -- Obtain source and target types. Note that we call Ancestor_Subtype
4329 -- here because the processing for generic instantiation always makes
4330 -- subtypes, and we want the original frozen actual types.
4332 -- If we are dealing with private types, then do the check on their
4333 -- fully declared counterparts if the full declarations have been
4334 -- encountered (they don't have to be visible, but they must exist!)
4336 Source
:= Ancestor_Subtype
(Etype
(First_Formal
(Act_Unit
)));
4338 if Is_Private_Type
(Source
)
4339 and then Present
(Underlying_Type
(Source
))
4341 Source
:= Underlying_Type
(Source
);
4344 Target
:= Ancestor_Subtype
(Etype
(Act_Unit
));
4346 -- If either type is generic, the instantiation happens within a generic
4347 -- unit, and there is nothing to check. The proper check
4348 -- will happen when the enclosing generic is instantiated.
4350 if Is_Generic_Type
(Source
) or else Is_Generic_Type
(Target
) then
4354 if Is_Private_Type
(Target
)
4355 and then Present
(Underlying_Type
(Target
))
4357 Target
:= Underlying_Type
(Target
);
4360 -- Source may be unconstrained array, but not target
4362 if Is_Array_Type
(Target
)
4363 and then not Is_Constrained
(Target
)
4366 ("unchecked conversion to unconstrained array not allowed", N
);
4370 -- Warn if conversion between two different convention pointers
4372 if Is_Access_Type
(Target
)
4373 and then Is_Access_Type
(Source
)
4374 and then Convention
(Target
) /= Convention
(Source
)
4375 and then Warn_On_Unchecked_Conversion
4377 -- Give warnings for subprogram pointers only on most targets. The
4378 -- exception is VMS, where data pointers can have different lengths
4379 -- depending on the pointer convention.
4381 if Is_Access_Subprogram_Type
(Target
)
4382 or else Is_Access_Subprogram_Type
(Source
)
4383 or else OpenVMS_On_Target
4386 ("?conversion between pointers with different conventions!", N
);
4390 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4391 -- warning when compiling GNAT-related sources.
4393 if Warn_On_Unchecked_Conversion
4394 and then not In_Predefined_Unit
(N
)
4395 and then RTU_Loaded
(Ada_Calendar
)
4397 (Chars
(Source
) = Name_Time
4399 Chars
(Target
) = Name_Time
)
4401 -- If Ada.Calendar is loaded and the name of one of the operands is
4402 -- Time, there is a good chance that this is Ada.Calendar.Time.
4405 Calendar_Time
: constant Entity_Id
:=
4406 Full_View
(RTE
(RO_CA_Time
));
4408 pragma Assert
(Present
(Calendar_Time
));
4410 if Source
= Calendar_Time
4411 or else Target
= Calendar_Time
4414 ("?representation of 'Time values may change between " &
4415 "'G'N'A'T versions", N
);
4420 -- Make entry in unchecked conversion table for later processing by
4421 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4422 -- (using values set by the back-end where possible). This is only done
4423 -- if the appropriate warning is active.
4425 if Warn_On_Unchecked_Conversion
then
4426 Unchecked_Conversions
.Append
4427 (New_Val
=> UC_Entry
'
4432 -- If both sizes are known statically now, then back end annotation
4433 -- is not required to do a proper check but if either size is not
4434 -- known statically, then we need the annotation.
4436 if Known_Static_RM_Size (Source)
4437 and then Known_Static_RM_Size (Target)
4441 Back_Annotate_Rep_Info := True;
4445 -- If unchecked conversion to access type, and access type is declared
4446 -- in the same unit as the unchecked conversion, then set the
4447 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4450 if Is_Access_Type (Target) and then
4451 In_Same_Source_Unit (Target, N)
4453 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4456 -- Generate N_Validate_Unchecked_Conversion node for back end in
4457 -- case the back end needs to perform special validation checks.
4459 -- Shouldn't this be in Exp_Ch13, since the check only gets done
4460 -- if we have full expansion and the back end is called ???
4463 Make_Validate_Unchecked_Conversion (Sloc (N));
4464 Set_Source_Type (Vnode, Source);
4465 Set_Target_Type (Vnode, Target);
4467 -- If the unchecked conversion node is in a list, just insert before it.
4468 -- If not we have some strange case, not worth bothering about.
4470 if Is_List_Member (N) then
4471 Insert_After (N, Vnode);
4473 end Validate_Unchecked_Conversion;
4475 ------------------------------------
4476 -- Validate_Unchecked_Conversions --
4477 ------------------------------------
4479 procedure Validate_Unchecked_Conversions is
4481 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4483 T : UC_Entry renames Unchecked_Conversions.Table (N);
4485 Eloc : constant Source_Ptr := T.Eloc;
4486 Source : constant Entity_Id := T.Source;
4487 Target : constant Entity_Id := T.Target;
4493 -- This validation check, which warns if we have unequal sizes for
4494 -- unchecked conversion, and thus potentially implementation
4495 -- dependent semantics, is one of the few occasions on which we
4496 -- use the official RM size instead of Esize. See description in
4497 -- Einfo "Handling of Type'Size Values" for details.
4499 if Serious_Errors_Detected = 0
4500 and then Known_Static_RM_Size (Source)
4501 and then Known_Static_RM_Size (Target)
4503 -- Don't do the check if warnings off for either type, note the
4504 -- deliberate use of OR here instead of OR ELSE to get the flag
4505 -- Warnings_Off_Used set for both types if appropriate.
4507 and then not (Has_Warnings_Off (Source)
4509 Has_Warnings_Off (Target))
4511 Source_Siz := RM_Size (Source);
4512 Target_Siz := RM_Size (Target);
4514 if Source_Siz /= Target_Siz then
4516 ("?types for unchecked conversion have different sizes!",
4519 if All_Errors_Mode then
4520 Error_Msg_Name_1 := Chars (Source);
4521 Error_Msg_Uint_1 := Source_Siz;
4522 Error_Msg_Name_2 := Chars (Target);
4523 Error_Msg_Uint_2 := Target_Siz;
4524 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
4526 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4528 if Is_Discrete_Type (Source)
4529 and then Is_Discrete_Type (Target)
4531 if Source_Siz > Target_Siz then
4533 ("\?^ high order bits of source will be ignored!",
4536 elsif Is_Unsigned_Type (Source) then
4538 ("\?source will be extended with ^ high order " &
4539 "zero bits?!", Eloc);
4543 ("\?source will be extended with ^ high order " &
4548 elsif Source_Siz < Target_Siz then
4549 if Is_Discrete_Type (Target) then
4550 if Bytes_Big_Endian then
4552 ("\?target value will include ^ undefined " &
4557 ("\?target value will include ^ undefined " &
4564 ("\?^ trailing bits of target value will be " &
4565 "undefined!", Eloc);
4568 else pragma Assert (Source_Siz > Target_Siz);
4570 ("\?^ trailing bits of source will be ignored!",
4577 -- If both types are access types, we need to check the alignment.
4578 -- If the alignment of both is specified, we can do it here.
4580 if Serious_Errors_Detected = 0
4581 and then Ekind (Source) in Access_Kind
4582 and then Ekind (Target) in Access_Kind
4583 and then Target_Strict_Alignment
4584 and then Present (Designated_Type (Source))
4585 and then Present (Designated_Type (Target))
4588 D_Source : constant Entity_Id := Designated_Type (Source);
4589 D_Target : constant Entity_Id := Designated_Type (Target);
4592 if Known_Alignment (D_Source)
4593 and then Known_Alignment (D_Target)
4596 Source_Align : constant Uint := Alignment (D_Source);
4597 Target_Align : constant Uint := Alignment (D_Target);
4600 if Source_Align < Target_Align
4601 and then not Is_Tagged_Type (D_Source)
4603 -- Suppress warning if warnings suppressed on either
4604 -- type or either designated type. Note the use of
4605 -- OR here instead of OR ELSE. That is intentional,
4606 -- we would like to set flag Warnings_Off_Used in
4607 -- all types for which warnings are suppressed.
4609 and then not (Has_Warnings_Off (D_Source)
4611 Has_Warnings_Off (D_Target)
4613 Has_Warnings_Off (Source)
4615 Has_Warnings_Off (Target))
4617 Error_Msg_Uint_1 := Target_Align;
4618 Error_Msg_Uint_2 := Source_Align;
4619 Error_Msg_Node_1 := D_Target;
4620 Error_Msg_Node_2 := D_Source;
4622 ("?alignment of & (^) is stricter than " &
4623 "alignment of & (^)!", Eloc);
4625 ("\?resulting access value may have invalid " &
4626 "alignment!", Eloc);
4634 end Validate_Unchecked_Conversions;