1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Disp; use Exp_Disp;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
35 with Lib.Xref; use Lib.Xref;
36 with Namet; use Namet;
37 with Nlists; use Nlists;
38 with Nmake; use Nmake;
40 with Restrict; use Restrict;
41 with Rident; use Rident;
42 with Rtsfind; use Rtsfind;
44 with Sem_Aux; use Sem_Aux;
45 with Sem_Ch3; use Sem_Ch3;
46 with Sem_Ch8; use Sem_Ch8;
47 with Sem_Disp; use Sem_Disp;
48 with Sem_Eval; use Sem_Eval;
49 with Sem_Res; use Sem_Res;
50 with Sem_Type; use Sem_Type;
51 with Sem_Util; use Sem_Util;
52 with Sem_Warn; use Sem_Warn;
53 with Snames; use Snames;
54 with Stand; use Stand;
55 with Sinfo; use Sinfo;
57 with Targparm; use Targparm;
58 with Ttypes; use Ttypes;
59 with Tbuild; use Tbuild;
60 with Urealp; use Urealp;
62 with GNAT.Heap_Sort_G;
64 package body Sem_Ch13 is
66 SSU : constant Pos := System_Storage_Unit;
67 -- Convenient short hand for commonly used constant
69 -----------------------
70 -- Local Subprograms --
71 -----------------------
73 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
74 -- This routine is called after setting the Esize of type entity Typ.
75 -- The purpose is to deal with the situation where an alignment has been
76 -- inherited from a derived type that is no longer appropriate for the
77 -- new Esize value. In this case, we reset the Alignment to unknown.
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
186 -- Processing depends on version of Ada
188 -- For Ada 95, we just renumber bits within a storage unit. We do the
189 -- same for Ada 83 mode, since we recognize pragma Bit_Order in Ada 83,
190 -- and are free to add this extension.
192 if Ada_Version < Ada_2005 then
193 Comp := First_Component_Or_Discriminant (R);
194 while Present (Comp) loop
195 CC := Component_Clause (Comp);
197 -- If component clause is present, then deal with the non-default
198 -- bit order case for Ada 95 mode.
200 -- We only do this processing for the base type, and in fact that
201 -- is important, since otherwise if there are record subtypes, we
202 -- could reverse the bits once for each subtype, which is wrong.
205 and then Ekind (R) = E_Record_Type
208 CFB : constant Uint := Component_Bit_Offset (Comp);
209 CSZ : constant Uint := Esize (Comp);
210 CLC : constant Node_Id := Component_Clause (Comp);
211 Pos : constant Node_Id := Position (CLC);
212 FB : constant Node_Id := First_Bit (CLC);
214 Storage_Unit_Offset : constant Uint :=
215 CFB / System_Storage_Unit;
217 Start_Bit : constant Uint :=
218 CFB mod System_Storage_Unit;
221 -- Cases where field goes over storage unit boundary
223 if Start_Bit + CSZ > System_Storage_Unit then
225 -- Allow multi-byte field but generate warning
227 if Start_Bit mod System_Storage_Unit = 0
228 and then CSZ mod System_Storage_Unit = 0
231 ("multi-byte field specified with non-standard"
232 & " Bit_Order?", CLC);
234 if Bytes_Big_Endian then
236 ("bytes are not reversed "
237 & "(component is big-endian)?", CLC);
240 ("bytes are not reversed "
241 & "(component is little-endian)?", CLC);
244 -- Do not allow non-contiguous field
248 ("attempt to specify non-contiguous field "
249 & "not permitted", CLC);
251 ("\caused by non-standard Bit_Order "
254 ("\consider possibility of using "
255 & "Ada 2005 mode here", CLC);
258 -- Case where field fits in one storage unit
261 -- Give warning if suspicious component clause
263 if Intval (FB) >= System_Storage_Unit
264 and then Warn_On_Reverse_Bit_Order
267 ("?Bit_Order clause does not affect " &
268 "byte ordering", Pos);
270 Intval (Pos) + Intval (FB) /
273 ("?position normalized to ^ before bit " &
274 "order interpreted", Pos);
277 -- Here is where we fix up the Component_Bit_Offset value
278 -- to account for the reverse bit order. Some examples of
279 -- what needs to be done are:
281 -- First_Bit .. Last_Bit Component_Bit_Offset
293 -- The rule is that the first bit is is obtained by
294 -- subtracting the old ending bit from storage_unit - 1.
296 Set_Component_Bit_Offset
298 (Storage_Unit_Offset * System_Storage_Unit) +
299 (System_Storage_Unit - 1) -
300 (Start_Bit + CSZ - 1));
302 Set_Normalized_First_Bit
304 Component_Bit_Offset (Comp) mod
305 System_Storage_Unit);
310 Next_Component_Or_Discriminant (Comp);
313 -- For Ada 2005, we do machine scalar processing, as fully described In
314 -- AI-133. This involves gathering all components which start at the
315 -- same byte offset and processing them together. Same approach is still
316 -- valid in later versions including Ada 2012.
320 Max_Machine_Scalar_Size : constant Uint :=
322 (Standard_Long_Long_Integer_Size);
323 -- We use this as the maximum machine scalar size
326 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
329 -- This first loop through components does two things. First it
330 -- deals with the case of components with component clauses whose
331 -- length is greater than the maximum machine scalar size (either
332 -- accepting them or rejecting as needed). Second, it counts the
333 -- number of components with component clauses whose length does
334 -- not exceed this maximum for later processing.
337 Comp := First_Component_Or_Discriminant (R);
338 while Present (Comp) loop
339 CC := Component_Clause (Comp);
343 Fbit : constant Uint :=
344 Static_Integer (First_Bit (CC));
347 -- Case of component with size > max machine scalar
349 if Esize (Comp) > Max_Machine_Scalar_Size then
351 -- Must begin on byte boundary
353 if Fbit mod SSU /= 0 then
355 ("illegal first bit value for "
356 & "reverse bit order",
358 Error_Msg_Uint_1 := SSU;
359 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
362 ("\must be a multiple of ^ "
363 & "if size greater than ^",
366 -- Must end on byte boundary
368 elsif Esize (Comp) mod SSU /= 0 then
370 ("illegal last bit value for "
371 & "reverse bit order",
373 Error_Msg_Uint_1 := SSU;
374 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
377 ("\must be a multiple of ^ if size "
381 -- OK, give warning if enabled
383 elsif Warn_On_Reverse_Bit_Order then
385 ("multi-byte field specified with "
386 & " non-standard Bit_Order?", CC);
388 if Bytes_Big_Endian then
390 ("\bytes are not reversed "
391 & "(component is big-endian)?", CC);
394 ("\bytes are not reversed "
395 & "(component is little-endian)?", CC);
399 -- Case where size is not greater than max machine
400 -- scalar. For now, we just count these.
403 Num_CC := Num_CC + 1;
408 Next_Component_Or_Discriminant (Comp);
411 -- We need to sort the component clauses on the basis of the
412 -- Position values in the clause, so we can group clauses with
413 -- the same Position. together to determine the relevant machine
417 Comps : array (0 .. Num_CC) of Entity_Id;
418 -- Array to collect component and discriminant entities. The
419 -- data starts at index 1, the 0'th entry is for the sort
422 function CP_Lt (Op1, Op2 : Natural) return Boolean;
423 -- Compare routine for Sort
425 procedure CP_Move (From : Natural; To : Natural);
426 -- Move routine for Sort
428 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
432 -- Start and stop positions in the component list of the set of
433 -- components with the same starting position (that constitute
434 -- components in a single machine scalar).
437 -- Maximum last bit value of any component in this set
440 -- Corresponding machine scalar size
446 function CP_Lt (Op1, Op2 : Natural) return Boolean is
448 return Position (Component_Clause (Comps (Op1))) <
449 Position (Component_Clause (Comps (Op2)));
456 procedure CP_Move (From : Natural; To : Natural) is
458 Comps (To) := Comps (From);
461 -- Start of processing for Sort_CC
464 -- Collect the component clauses
467 Comp := First_Component_Or_Discriminant (R);
468 while Present (Comp) loop
469 if Present (Component_Clause (Comp))
470 and then Esize (Comp) <= Max_Machine_Scalar_Size
472 Num_CC := Num_CC + 1;
473 Comps (Num_CC) := Comp;
476 Next_Component_Or_Discriminant (Comp);
479 -- Sort by ascending position number
481 Sorting.Sort (Num_CC);
483 -- We now have all the components whose size does not exceed
484 -- the max machine scalar value, sorted by starting position.
485 -- In this loop we gather groups of clauses starting at the
486 -- same position, to process them in accordance with AI-133.
489 while Stop < Num_CC loop
494 (Last_Bit (Component_Clause (Comps (Start))));
495 while Stop < Num_CC loop
497 (Position (Component_Clause (Comps (Stop + 1)))) =
499 (Position (Component_Clause (Comps (Stop))))
507 (Component_Clause (Comps (Stop)))));
513 -- Now we have a group of component clauses from Start to
514 -- Stop whose positions are identical, and MaxL is the
515 -- maximum last bit value of any of these components.
517 -- We need to determine the corresponding machine scalar
518 -- size. This loop assumes that machine scalar sizes are
519 -- even, and that each possible machine scalar has twice
520 -- as many bits as the next smaller one.
522 MSS := Max_Machine_Scalar_Size;
524 and then (MSS / 2) >= SSU
525 and then (MSS / 2) > MaxL
530 -- Here is where we fix up the Component_Bit_Offset value
531 -- to account for the reverse bit order. Some examples of
532 -- what needs to be done for the case of a machine scalar
535 -- First_Bit .. Last_Bit Component_Bit_Offset
547 -- The rule is that the first bit is obtained by subtracting
548 -- the old ending bit from machine scalar size - 1.
550 for C in Start .. Stop loop
552 Comp : constant Entity_Id := Comps (C);
553 CC : constant Node_Id :=
554 Component_Clause (Comp);
555 LB : constant Uint :=
556 Static_Integer (Last_Bit (CC));
557 NFB : constant Uint := MSS - Uint_1 - LB;
558 NLB : constant Uint := NFB + Esize (Comp) - 1;
559 Pos : constant Uint :=
560 Static_Integer (Position (CC));
563 if Warn_On_Reverse_Bit_Order then
564 Error_Msg_Uint_1 := MSS;
566 ("info: reverse bit order in machine " &
567 "scalar of length^?", First_Bit (CC));
568 Error_Msg_Uint_1 := NFB;
569 Error_Msg_Uint_2 := NLB;
571 if Bytes_Big_Endian then
573 ("?\info: big-endian range for "
574 & "component & is ^ .. ^",
575 First_Bit (CC), Comp);
578 ("?\info: little-endian range "
579 & "for component & is ^ .. ^",
580 First_Bit (CC), Comp);
584 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
585 Set_Normalized_First_Bit (Comp, NFB mod SSU);
592 end Adjust_Record_For_Reverse_Bit_Order;
594 --------------------------------------
595 -- Alignment_Check_For_Esize_Change --
596 --------------------------------------
598 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
600 -- If the alignment is known, and not set by a rep clause, and is
601 -- inconsistent with the size being set, then reset it to unknown,
602 -- we assume in this case that the size overrides the inherited
603 -- alignment, and that the alignment must be recomputed.
605 if Known_Alignment (Typ)
606 and then not Has_Alignment_Clause (Typ)
607 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
609 Init_Alignment (Typ);
611 end Alignment_Check_For_Esize_Change;
613 -----------------------
614 -- Analyze_At_Clause --
615 -----------------------
617 -- An at clause is replaced by the corresponding Address attribute
618 -- definition clause that is the preferred approach in Ada 95.
620 procedure Analyze_At_Clause (N : Node_Id) is
621 CS : constant Boolean := Comes_From_Source (N);
624 -- This is an obsolescent feature
626 Check_Restriction (No_Obsolescent_Features, N);
628 if Warn_On_Obsolescent_Feature then
630 ("at clause is an obsolescent feature (RM J.7(2))?", N);
632 ("\use address attribute definition clause instead?", N);
635 -- Rewrite as address clause
638 Make_Attribute_Definition_Clause (Sloc (N),
639 Name => Identifier (N),
640 Chars => Name_Address,
641 Expression => Expression (N)));
643 -- We preserve Comes_From_Source, since logically the clause still
644 -- comes from the source program even though it is changed in form.
646 Set_Comes_From_Source (N, CS);
648 -- Analyze rewritten clause
650 Analyze_Attribute_Definition_Clause (N);
651 end Analyze_At_Clause;
653 -----------------------------------------
654 -- Analyze_Attribute_Definition_Clause --
655 -----------------------------------------
657 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
658 Loc : constant Source_Ptr := Sloc (N);
659 Nam : constant Node_Id := Name (N);
660 Attr : constant Name_Id := Chars (N);
661 Expr : constant Node_Id := Expression (N);
662 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
666 FOnly : Boolean := False;
667 -- Reset to True for subtype specific attribute (Alignment, Size)
668 -- and for stream attributes, i.e. those cases where in the call
669 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
670 -- rules are checked. Note that the case of stream attributes is not
671 -- clear from the RM, but see AI95-00137. Also, the RM seems to
672 -- disallow Storage_Size for derived task types, but that is also
673 -- clearly unintentional.
675 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
676 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
677 -- definition clauses.
679 -----------------------------------
680 -- Analyze_Stream_TSS_Definition --
681 -----------------------------------
683 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
684 Subp : Entity_Id := Empty;
689 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
691 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
692 -- Return true if the entity is a subprogram with an appropriate
693 -- profile for the attribute being defined.
695 ----------------------
696 -- Has_Good_Profile --
697 ----------------------
699 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
701 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
702 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
703 (False => E_Procedure, True => E_Function);
707 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
711 F := First_Formal (Subp);
714 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
715 or else Designated_Type (Etype (F)) /=
716 Class_Wide_Type (RTE (RE_Root_Stream_Type))
721 if not Is_Function then
725 Expected_Mode : constant array (Boolean) of Entity_Kind :=
726 (False => E_In_Parameter,
727 True => E_Out_Parameter);
729 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
740 return Base_Type (Typ) = Base_Type (Ent)
741 and then No (Next_Formal (F));
742 end Has_Good_Profile;
744 -- Start of processing for Analyze_Stream_TSS_Definition
749 if not Is_Type (U_Ent) then
750 Error_Msg_N ("local name must be a subtype", Nam);
754 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
756 -- If Pnam is present, it can be either inherited from an ancestor
757 -- type (in which case it is legal to redefine it for this type), or
758 -- be a previous definition of the attribute for the same type (in
759 -- which case it is illegal).
761 -- In the first case, it will have been analyzed already, and we
762 -- can check that its profile does not match the expected profile
763 -- for a stream attribute of U_Ent. In the second case, either Pnam
764 -- has been analyzed (and has the expected profile), or it has not
765 -- been analyzed yet (case of a type that has not been frozen yet
766 -- and for which the stream attribute has been set using Set_TSS).
769 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
771 Error_Msg_Sloc := Sloc (Pnam);
772 Error_Msg_Name_1 := Attr;
773 Error_Msg_N ("% attribute already defined #", Nam);
779 if Is_Entity_Name (Expr) then
780 if not Is_Overloaded (Expr) then
781 if Has_Good_Profile (Entity (Expr)) then
782 Subp := Entity (Expr);
786 Get_First_Interp (Expr, I, It);
787 while Present (It.Nam) loop
788 if Has_Good_Profile (It.Nam) then
793 Get_Next_Interp (I, It);
798 if Present (Subp) then
799 if Is_Abstract_Subprogram (Subp) then
800 Error_Msg_N ("stream subprogram must not be abstract", Expr);
804 Set_Entity (Expr, Subp);
805 Set_Etype (Expr, Etype (Subp));
807 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
810 Error_Msg_Name_1 := Attr;
811 Error_Msg_N ("incorrect expression for% attribute", Expr);
813 end Analyze_Stream_TSS_Definition;
815 -- Start of processing for Analyze_Attribute_Definition_Clause
818 -- Process Ignore_Rep_Clauses option
820 if Ignore_Rep_Clauses then
823 -- The following should be ignored. They do not affect legality
824 -- and may be target dependent. The basic idea of -gnatI is to
825 -- ignore any rep clauses that may be target dependent but do not
826 -- affect legality (except possibly to be rejected because they
827 -- are incompatible with the compilation target).
829 when Attribute_Alignment |
830 Attribute_Bit_Order |
831 Attribute_Component_Size |
832 Attribute_Machine_Radix |
833 Attribute_Object_Size |
836 Attribute_Stream_Size |
837 Attribute_Value_Size =>
839 Rewrite (N, Make_Null_Statement (Sloc (N)));
842 -- The following should not be ignored, because in the first place
843 -- they are reasonably portable, and should not cause problems in
844 -- compiling code from another target, and also they do affect
845 -- legality, e.g. failing to provide a stream attribute for a
846 -- type may make a program illegal.
848 when Attribute_External_Tag |
852 Attribute_Storage_Pool |
853 Attribute_Storage_Size |
857 -- Other cases are errors ("attribute& cannot be set with
858 -- definition clause"), which will be caught below.
868 if Rep_Item_Too_Early (Ent, N) then
872 -- Rep clause applies to full view of incomplete type or private type if
873 -- we have one (if not, this is a premature use of the type). However,
874 -- certain semantic checks need to be done on the specified entity (i.e.
875 -- the private view), so we save it in Ent.
877 if Is_Private_Type (Ent)
878 and then Is_Derived_Type (Ent)
879 and then not Is_Tagged_Type (Ent)
880 and then No (Full_View (Ent))
882 -- If this is a private type whose completion is a derivation from
883 -- another private type, there is no full view, and the attribute
884 -- belongs to the type itself, not its underlying parent.
888 elsif Ekind (Ent) = E_Incomplete_Type then
890 -- The attribute applies to the full view, set the entity of the
891 -- attribute definition accordingly.
893 Ent := Underlying_Type (Ent);
895 Set_Entity (Nam, Ent);
898 U_Ent := Underlying_Type (Ent);
901 -- Complete other routine error checks
903 if Etype (Nam) = Any_Type then
906 elsif Scope (Ent) /= Current_Scope then
907 Error_Msg_N ("entity must be declared in this scope", Nam);
910 elsif No (U_Ent) then
913 elsif Is_Type (U_Ent)
914 and then not Is_First_Subtype (U_Ent)
915 and then Id /= Attribute_Object_Size
916 and then Id /= Attribute_Value_Size
917 and then not From_At_Mod (N)
919 Error_Msg_N ("cannot specify attribute for subtype", Nam);
923 -- Switch on particular attribute
931 -- Address attribute definition clause
933 when Attribute_Address => Address : begin
935 -- A little error check, catch for X'Address use X'Address;
937 if Nkind (Nam) = N_Identifier
938 and then Nkind (Expr) = N_Attribute_Reference
939 and then Attribute_Name (Expr) = Name_Address
940 and then Nkind (Prefix (Expr)) = N_Identifier
941 and then Chars (Nam) = Chars (Prefix (Expr))
944 ("address for & is self-referencing", Prefix (Expr), Ent);
948 -- Not that special case, carry on with analysis of expression
950 Analyze_And_Resolve (Expr, RTE (RE_Address));
952 -- Even when ignoring rep clauses we need to indicate that the
953 -- entity has an address clause and thus it is legal to declare
956 if Ignore_Rep_Clauses then
957 if Ekind_In (U_Ent, E_Variable, E_Constant) then
958 Record_Rep_Item (U_Ent, N);
964 if Present (Address_Clause (U_Ent)) then
965 Error_Msg_N ("address already given for &", Nam);
967 -- Case of address clause for subprogram
969 elsif Is_Subprogram (U_Ent) then
970 if Has_Homonym (U_Ent) then
972 ("address clause cannot be given " &
973 "for overloaded subprogram",
978 -- For subprograms, all address clauses are permitted, and we
979 -- mark the subprogram as having a deferred freeze so that Gigi
980 -- will not elaborate it too soon.
982 -- Above needs more comments, what is too soon about???
984 Set_Has_Delayed_Freeze (U_Ent);
986 -- Case of address clause for entry
988 elsif Ekind (U_Ent) = E_Entry then
989 if Nkind (Parent (N)) = N_Task_Body then
991 ("entry address must be specified in task spec", Nam);
995 -- For entries, we require a constant address
997 Check_Constant_Address_Clause (Expr, U_Ent);
999 -- Special checks for task types
1001 if Is_Task_Type (Scope (U_Ent))
1002 and then Comes_From_Source (Scope (U_Ent))
1005 ("?entry address declared for entry in task type", N);
1007 ("\?only one task can be declared of this type", N);
1010 -- Entry address clauses are obsolescent
1012 Check_Restriction (No_Obsolescent_Features, N);
1014 if Warn_On_Obsolescent_Feature then
1016 ("attaching interrupt to task entry is an " &
1017 "obsolescent feature (RM J.7.1)?", N);
1019 ("\use interrupt procedure instead?", N);
1022 -- Case of an address clause for a controlled object which we
1023 -- consider to be erroneous.
1025 elsif Is_Controlled (Etype (U_Ent))
1026 or else Has_Controlled_Component (Etype (U_Ent))
1029 ("?controlled object& must not be overlaid", Nam, U_Ent);
1031 ("\?Program_Error will be raised at run time", Nam);
1032 Insert_Action (Declaration_Node (U_Ent),
1033 Make_Raise_Program_Error (Loc,
1034 Reason => PE_Overlaid_Controlled_Object));
1037 -- Case of address clause for a (non-controlled) object
1040 Ekind (U_Ent) = E_Variable
1042 Ekind (U_Ent) = E_Constant
1045 Expr : constant Node_Id := Expression (N);
1050 -- Exported variables cannot have an address clause, because
1051 -- this cancels the effect of the pragma Export.
1053 if Is_Exported (U_Ent) then
1055 ("cannot export object with address clause", Nam);
1059 Find_Overlaid_Entity (N, O_Ent, Off);
1061 -- Overlaying controlled objects is erroneous
1064 and then (Has_Controlled_Component (Etype (O_Ent))
1065 or else Is_Controlled (Etype (O_Ent)))
1068 ("?cannot overlay with controlled object", Expr);
1070 ("\?Program_Error will be raised at run time", Expr);
1071 Insert_Action (Declaration_Node (U_Ent),
1072 Make_Raise_Program_Error (Loc,
1073 Reason => PE_Overlaid_Controlled_Object));
1076 elsif Present (O_Ent)
1077 and then Ekind (U_Ent) = E_Constant
1078 and then not Is_Constant_Object (O_Ent)
1080 Error_Msg_N ("constant overlays a variable?", Expr);
1082 elsif Present (Renamed_Object (U_Ent)) then
1084 ("address clause not allowed"
1085 & " for a renaming declaration (RM 13.1(6))", Nam);
1088 -- Imported variables can have an address clause, but then
1089 -- the import is pretty meaningless except to suppress
1090 -- initializations, so we do not need such variables to
1091 -- be statically allocated (and in fact it causes trouble
1092 -- if the address clause is a local value).
1094 elsif Is_Imported (U_Ent) then
1095 Set_Is_Statically_Allocated (U_Ent, False);
1098 -- We mark a possible modification of a variable with an
1099 -- address clause, since it is likely aliasing is occurring.
1101 Note_Possible_Modification (Nam, Sure => False);
1103 -- Here we are checking for explicit overlap of one variable
1104 -- by another, and if we find this then mark the overlapped
1105 -- variable as also being volatile to prevent unwanted
1106 -- optimizations. This is a significant pessimization so
1107 -- avoid it when there is an offset, i.e. when the object
1108 -- is composite; they cannot be optimized easily anyway.
1111 and then Is_Object (O_Ent)
1114 Set_Treat_As_Volatile (O_Ent);
1117 -- Legality checks on the address clause for initialized
1118 -- objects is deferred until the freeze point, because
1119 -- a subsequent pragma might indicate that the object is
1120 -- imported and thus not initialized.
1122 Set_Has_Delayed_Freeze (U_Ent);
1124 -- If an initialization call has been generated for this
1125 -- object, it needs to be deferred to after the freeze node
1126 -- we have just now added, otherwise GIGI will see a
1127 -- reference to the variable (as actual to the IP call)
1128 -- before its definition.
1131 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1133 if Present (Init_Call) then
1135 Append_Freeze_Action (U_Ent, Init_Call);
1139 if Is_Exported (U_Ent) then
1141 ("& cannot be exported if an address clause is given",
1144 ("\define and export a variable " &
1145 "that holds its address instead",
1149 -- Entity has delayed freeze, so we will generate an
1150 -- alignment check at the freeze point unless suppressed.
1152 if not Range_Checks_Suppressed (U_Ent)
1153 and then not Alignment_Checks_Suppressed (U_Ent)
1155 Set_Check_Address_Alignment (N);
1158 -- Kill the size check code, since we are not allocating
1159 -- the variable, it is somewhere else.
1161 Kill_Size_Check_Code (U_Ent);
1163 -- If the address clause is of the form:
1165 -- for Y'Address use X'Address
1169 -- Const : constant Address := X'Address;
1171 -- for Y'Address use Const;
1173 -- then we make an entry in the table for checking the size
1174 -- and alignment of the overlaying variable. We defer this
1175 -- check till after code generation to take full advantage
1176 -- of the annotation done by the back end. This entry is
1177 -- only made if the address clause comes from source.
1178 -- If the entity has a generic type, the check will be
1179 -- performed in the instance if the actual type justifies
1180 -- it, and we do not insert the clause in the table to
1181 -- prevent spurious warnings.
1183 if Address_Clause_Overlay_Warnings
1184 and then Comes_From_Source (N)
1185 and then Present (O_Ent)
1186 and then Is_Object (O_Ent)
1188 if not Is_Generic_Type (Etype (U_Ent)) then
1189 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1192 -- If variable overlays a constant view, and we are
1193 -- warning on overlays, then mark the variable as
1194 -- overlaying a constant (we will give warnings later
1195 -- if this variable is assigned).
1197 if Is_Constant_Object (O_Ent)
1198 and then Ekind (U_Ent) = E_Variable
1200 Set_Overlays_Constant (U_Ent);
1205 -- Not a valid entity for an address clause
1208 Error_Msg_N ("address cannot be given for &", Nam);
1216 -- Alignment attribute definition clause
1218 when Attribute_Alignment => Alignment : declare
1219 Align : constant Uint := Get_Alignment_Value (Expr);
1224 if not Is_Type (U_Ent)
1225 and then Ekind (U_Ent) /= E_Variable
1226 and then Ekind (U_Ent) /= E_Constant
1228 Error_Msg_N ("alignment cannot be given for &", Nam);
1230 elsif Has_Alignment_Clause (U_Ent) then
1231 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1232 Error_Msg_N ("alignment clause previously given#", N);
1234 elsif Align /= No_Uint then
1235 Set_Has_Alignment_Clause (U_Ent);
1236 Set_Alignment (U_Ent, Align);
1238 -- For an array type, U_Ent is the first subtype. In that case,
1239 -- also set the alignment of the anonymous base type so that
1240 -- other subtypes (such as the itypes for aggregates of the
1241 -- type) also receive the expected alignment.
1243 if Is_Array_Type (U_Ent) then
1244 Set_Alignment (Base_Type (U_Ent), Align);
1253 -- Bit_Order attribute definition clause
1255 when Attribute_Bit_Order => Bit_Order : declare
1257 if not Is_Record_Type (U_Ent) then
1259 ("Bit_Order can only be defined for record type", Nam);
1262 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1264 if Etype (Expr) = Any_Type then
1267 elsif not Is_Static_Expression (Expr) then
1268 Flag_Non_Static_Expr
1269 ("Bit_Order requires static expression!", Expr);
1272 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1273 Set_Reverse_Bit_Order (U_Ent, True);
1279 --------------------
1280 -- Component_Size --
1281 --------------------
1283 -- Component_Size attribute definition clause
1285 when Attribute_Component_Size => Component_Size_Case : declare
1286 Csize : constant Uint := Static_Integer (Expr);
1289 New_Ctyp : Entity_Id;
1293 if not Is_Array_Type (U_Ent) then
1294 Error_Msg_N ("component size requires array type", Nam);
1298 Btype := Base_Type (U_Ent);
1300 if Has_Component_Size_Clause (Btype) then
1302 ("component size clause for& previously given", Nam);
1304 elsif Csize /= No_Uint then
1305 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
1307 if Has_Aliased_Components (Btype)
1310 and then Csize /= 16
1313 ("component size incorrect for aliased components", N);
1317 -- For the biased case, build a declaration for a subtype
1318 -- that will be used to represent the biased subtype that
1319 -- reflects the biased representation of components. We need
1320 -- this subtype to get proper conversions on referencing
1321 -- elements of the array. Note that component size clauses
1322 -- are ignored in VM mode.
1324 if VM_Target = No_VM then
1327 Make_Defining_Identifier (Loc,
1329 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1332 Make_Subtype_Declaration (Loc,
1333 Defining_Identifier => New_Ctyp,
1334 Subtype_Indication =>
1335 New_Occurrence_Of (Component_Type (Btype), Loc));
1337 Set_Parent (Decl, N);
1338 Analyze (Decl, Suppress => All_Checks);
1340 Set_Has_Delayed_Freeze (New_Ctyp, False);
1341 Set_Esize (New_Ctyp, Csize);
1342 Set_RM_Size (New_Ctyp, Csize);
1343 Init_Alignment (New_Ctyp);
1344 Set_Has_Biased_Representation (New_Ctyp, True);
1345 Set_Is_Itype (New_Ctyp, True);
1346 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1348 Set_Component_Type (Btype, New_Ctyp);
1350 if Warn_On_Biased_Representation then
1352 ("?component size clause forces biased "
1353 & "representation", N);
1357 Set_Component_Size (Btype, Csize);
1359 -- For VM case, we ignore component size clauses
1362 -- Give a warning unless we are in GNAT mode, in which case
1363 -- the warning is suppressed since it is not useful.
1365 if not GNAT_Mode then
1367 ("?component size ignored in this configuration", N);
1371 Set_Has_Component_Size_Clause (Btype, True);
1372 Set_Has_Non_Standard_Rep (Btype, True);
1374 end Component_Size_Case;
1380 when Attribute_External_Tag => External_Tag :
1382 if not Is_Tagged_Type (U_Ent) then
1383 Error_Msg_N ("should be a tagged type", Nam);
1386 Analyze_And_Resolve (Expr, Standard_String);
1388 if not Is_Static_Expression (Expr) then
1389 Flag_Non_Static_Expr
1390 ("static string required for tag name!", Nam);
1393 if VM_Target = No_VM then
1394 Set_Has_External_Tag_Rep_Clause (U_Ent);
1396 Error_Msg_Name_1 := Attr;
1398 ("% attribute unsupported in this configuration", Nam);
1401 if not Is_Library_Level_Entity (U_Ent) then
1403 ("?non-unique external tag supplied for &", N, U_Ent);
1405 ("?\same external tag applies to all subprogram calls", N);
1407 ("?\corresponding internal tag cannot be obtained", N);
1415 when Attribute_Input =>
1416 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1417 Set_Has_Specified_Stream_Input (Ent);
1423 -- Machine radix attribute definition clause
1425 when Attribute_Machine_Radix => Machine_Radix : declare
1426 Radix : constant Uint := Static_Integer (Expr);
1429 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1430 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1432 elsif Has_Machine_Radix_Clause (U_Ent) then
1433 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1434 Error_Msg_N ("machine radix clause previously given#", N);
1436 elsif Radix /= No_Uint then
1437 Set_Has_Machine_Radix_Clause (U_Ent);
1438 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1442 elsif Radix = 10 then
1443 Set_Machine_Radix_10 (U_Ent);
1445 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1454 -- Object_Size attribute definition clause
1456 when Attribute_Object_Size => Object_Size : declare
1457 Size : constant Uint := Static_Integer (Expr);
1460 pragma Warnings (Off, Biased);
1463 if not Is_Type (U_Ent) then
1464 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1466 elsif Has_Object_Size_Clause (U_Ent) then
1467 Error_Msg_N ("Object_Size already given for &", Nam);
1470 Check_Size (Expr, U_Ent, Size, Biased);
1478 UI_Mod (Size, 64) /= 0
1481 ("Object_Size must be 8, 16, 32, or multiple of 64",
1485 Set_Esize (U_Ent, Size);
1486 Set_Has_Object_Size_Clause (U_Ent);
1487 Alignment_Check_For_Esize_Change (U_Ent);
1495 when Attribute_Output =>
1496 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1497 Set_Has_Specified_Stream_Output (Ent);
1503 when Attribute_Read =>
1504 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1505 Set_Has_Specified_Stream_Read (Ent);
1511 -- Size attribute definition clause
1513 when Attribute_Size => Size : declare
1514 Size : constant Uint := Static_Integer (Expr);
1521 if Has_Size_Clause (U_Ent) then
1522 Error_Msg_N ("size already given for &", Nam);
1524 elsif not Is_Type (U_Ent)
1525 and then Ekind (U_Ent) /= E_Variable
1526 and then Ekind (U_Ent) /= E_Constant
1528 Error_Msg_N ("size cannot be given for &", Nam);
1530 elsif Is_Array_Type (U_Ent)
1531 and then not Is_Constrained (U_Ent)
1534 ("size cannot be given for unconstrained array", Nam);
1536 elsif Size /= No_Uint then
1537 if Is_Type (U_Ent) then
1540 Etyp := Etype (U_Ent);
1543 -- Check size, note that Gigi is in charge of checking that the
1544 -- size of an array or record type is OK. Also we do not check
1545 -- the size in the ordinary fixed-point case, since it is too
1546 -- early to do so (there may be subsequent small clause that
1547 -- affects the size). We can check the size if a small clause
1548 -- has already been given.
1550 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1551 or else Has_Small_Clause (U_Ent)
1553 Check_Size (Expr, Etyp, Size, Biased);
1554 Set_Has_Biased_Representation (U_Ent, Biased);
1556 if Biased and Warn_On_Biased_Representation then
1558 ("?size clause forces biased representation", N);
1562 -- For types set RM_Size and Esize if possible
1564 if Is_Type (U_Ent) then
1565 Set_RM_Size (U_Ent, Size);
1567 -- For scalar types, increase Object_Size to power of 2, but
1568 -- not less than a storage unit in any case (i.e., normally
1569 -- this means it will be byte addressable).
1571 if Is_Scalar_Type (U_Ent) then
1572 if Size <= System_Storage_Unit then
1573 Init_Esize (U_Ent, System_Storage_Unit);
1574 elsif Size <= 16 then
1575 Init_Esize (U_Ent, 16);
1576 elsif Size <= 32 then
1577 Init_Esize (U_Ent, 32);
1579 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1582 -- For all other types, object size = value size. The
1583 -- backend will adjust as needed.
1586 Set_Esize (U_Ent, Size);
1589 Alignment_Check_For_Esize_Change (U_Ent);
1591 -- For objects, set Esize only
1594 if Is_Elementary_Type (Etyp) then
1595 if Size /= System_Storage_Unit
1597 Size /= System_Storage_Unit * 2
1599 Size /= System_Storage_Unit * 4
1601 Size /= System_Storage_Unit * 8
1603 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1604 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1606 ("size for primitive object must be a power of 2"
1607 & " in the range ^-^", N);
1611 Set_Esize (U_Ent, Size);
1614 Set_Has_Size_Clause (U_Ent);
1622 -- Small attribute definition clause
1624 when Attribute_Small => Small : declare
1625 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1629 Analyze_And_Resolve (Expr, Any_Real);
1631 if Etype (Expr) = Any_Type then
1634 elsif not Is_Static_Expression (Expr) then
1635 Flag_Non_Static_Expr
1636 ("small requires static expression!", Expr);
1640 Small := Expr_Value_R (Expr);
1642 if Small <= Ureal_0 then
1643 Error_Msg_N ("small value must be greater than zero", Expr);
1649 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1651 ("small requires an ordinary fixed point type", Nam);
1653 elsif Has_Small_Clause (U_Ent) then
1654 Error_Msg_N ("small already given for &", Nam);
1656 elsif Small > Delta_Value (U_Ent) then
1658 ("small value must not be greater then delta value", Nam);
1661 Set_Small_Value (U_Ent, Small);
1662 Set_Small_Value (Implicit_Base, Small);
1663 Set_Has_Small_Clause (U_Ent);
1664 Set_Has_Small_Clause (Implicit_Base);
1665 Set_Has_Non_Standard_Rep (Implicit_Base);
1673 -- Storage_Pool attribute definition clause
1675 when Attribute_Storage_Pool => Storage_Pool : declare
1680 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1682 ("storage pool cannot be given for access-to-subprogram type",
1687 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
1690 ("storage pool can only be given for access types", Nam);
1693 elsif Is_Derived_Type (U_Ent) then
1695 ("storage pool cannot be given for a derived access type",
1698 elsif Has_Storage_Size_Clause (U_Ent) then
1699 Error_Msg_N ("storage size already given for &", Nam);
1702 elsif Present (Associated_Storage_Pool (U_Ent)) then
1703 Error_Msg_N ("storage pool already given for &", Nam);
1708 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1710 if not Denotes_Variable (Expr) then
1711 Error_Msg_N ("storage pool must be a variable", Expr);
1715 if Nkind (Expr) = N_Type_Conversion then
1716 T := Etype (Expression (Expr));
1721 -- The Stack_Bounded_Pool is used internally for implementing
1722 -- access types with a Storage_Size. Since it only work
1723 -- properly when used on one specific type, we need to check
1724 -- that it is not hijacked improperly:
1725 -- type T is access Integer;
1726 -- for T'Storage_Size use n;
1727 -- type Q is access Float;
1728 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1730 if RTE_Available (RE_Stack_Bounded_Pool)
1731 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1733 Error_Msg_N ("non-shareable internal Pool", Expr);
1737 -- If the argument is a name that is not an entity name, then
1738 -- we construct a renaming operation to define an entity of
1739 -- type storage pool.
1741 if not Is_Entity_Name (Expr)
1742 and then Is_Object_Reference (Expr)
1744 Pool := Make_Temporary (Loc, 'P', Expr);
1747 Rnode : constant Node_Id :=
1748 Make_Object_Renaming_Declaration (Loc,
1749 Defining_Identifier => Pool,
1751 New_Occurrence_Of (Etype (Expr), Loc),
1755 Insert_Before (N, Rnode);
1757 Set_Associated_Storage_Pool (U_Ent, Pool);
1760 elsif Is_Entity_Name (Expr) then
1761 Pool := Entity (Expr);
1763 -- If pool is a renamed object, get original one. This can
1764 -- happen with an explicit renaming, and within instances.
1766 while Present (Renamed_Object (Pool))
1767 and then Is_Entity_Name (Renamed_Object (Pool))
1769 Pool := Entity (Renamed_Object (Pool));
1772 if Present (Renamed_Object (Pool))
1773 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1774 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1776 Pool := Entity (Expression (Renamed_Object (Pool)));
1779 Set_Associated_Storage_Pool (U_Ent, Pool);
1781 elsif Nkind (Expr) = N_Type_Conversion
1782 and then Is_Entity_Name (Expression (Expr))
1783 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1785 Pool := Entity (Expression (Expr));
1786 Set_Associated_Storage_Pool (U_Ent, Pool);
1789 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1798 -- Storage_Size attribute definition clause
1800 when Attribute_Storage_Size => Storage_Size : declare
1801 Btype : constant Entity_Id := Base_Type (U_Ent);
1805 if Is_Task_Type (U_Ent) then
1806 Check_Restriction (No_Obsolescent_Features, N);
1808 if Warn_On_Obsolescent_Feature then
1810 ("storage size clause for task is an " &
1811 "obsolescent feature (RM J.9)?", N);
1812 Error_Msg_N ("\use Storage_Size pragma instead?", N);
1818 if not Is_Access_Type (U_Ent)
1819 and then Ekind (U_Ent) /= E_Task_Type
1821 Error_Msg_N ("storage size cannot be given for &", Nam);
1823 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1825 ("storage size cannot be given for a derived access type",
1828 elsif Has_Storage_Size_Clause (Btype) then
1829 Error_Msg_N ("storage size already given for &", Nam);
1832 Analyze_And_Resolve (Expr, Any_Integer);
1834 if Is_Access_Type (U_Ent) then
1835 if Present (Associated_Storage_Pool (U_Ent)) then
1836 Error_Msg_N ("storage pool already given for &", Nam);
1840 if Compile_Time_Known_Value (Expr)
1841 and then Expr_Value (Expr) = 0
1843 Set_No_Pool_Assigned (Btype);
1846 else -- Is_Task_Type (U_Ent)
1847 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1849 if Present (Sprag) then
1850 Error_Msg_Sloc := Sloc (Sprag);
1852 ("Storage_Size already specified#", Nam);
1857 Set_Has_Storage_Size_Clause (Btype);
1865 when Attribute_Stream_Size => Stream_Size : declare
1866 Size : constant Uint := Static_Integer (Expr);
1869 if Ada_Version <= Ada_95 then
1870 Check_Restriction (No_Implementation_Attributes, N);
1873 if Has_Stream_Size_Clause (U_Ent) then
1874 Error_Msg_N ("Stream_Size already given for &", Nam);
1876 elsif Is_Elementary_Type (U_Ent) then
1877 if Size /= System_Storage_Unit
1879 Size /= System_Storage_Unit * 2
1881 Size /= System_Storage_Unit * 4
1883 Size /= System_Storage_Unit * 8
1885 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1887 ("stream size for elementary type must be a"
1888 & " power of 2 and at least ^", N);
1890 elsif RM_Size (U_Ent) > Size then
1891 Error_Msg_Uint_1 := RM_Size (U_Ent);
1893 ("stream size for elementary type must be a"
1894 & " power of 2 and at least ^", N);
1897 Set_Has_Stream_Size_Clause (U_Ent);
1900 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1908 -- Value_Size attribute definition clause
1910 when Attribute_Value_Size => Value_Size : declare
1911 Size : constant Uint := Static_Integer (Expr);
1915 if not Is_Type (U_Ent) then
1916 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1919 (Get_Attribute_Definition_Clause
1920 (U_Ent, Attribute_Value_Size))
1922 Error_Msg_N ("Value_Size already given for &", Nam);
1924 elsif Is_Array_Type (U_Ent)
1925 and then not Is_Constrained (U_Ent)
1928 ("Value_Size cannot be given for unconstrained array", Nam);
1931 if Is_Elementary_Type (U_Ent) then
1932 Check_Size (Expr, U_Ent, Size, Biased);
1933 Set_Has_Biased_Representation (U_Ent, Biased);
1935 if Biased and Warn_On_Biased_Representation then
1937 ("?value size clause forces biased representation", N);
1941 Set_RM_Size (U_Ent, Size);
1949 when Attribute_Write =>
1950 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1951 Set_Has_Specified_Stream_Write (Ent);
1953 -- All other attributes cannot be set
1957 ("attribute& cannot be set with definition clause", N);
1960 -- The test for the type being frozen must be performed after
1961 -- any expression the clause has been analyzed since the expression
1962 -- itself might cause freezing that makes the clause illegal.
1964 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1967 end Analyze_Attribute_Definition_Clause;
1969 ----------------------------
1970 -- Analyze_Code_Statement --
1971 ----------------------------
1973 procedure Analyze_Code_Statement (N : Node_Id) is
1974 HSS : constant Node_Id := Parent (N);
1975 SBody : constant Node_Id := Parent (HSS);
1976 Subp : constant Entity_Id := Current_Scope;
1983 -- Analyze and check we get right type, note that this implements the
1984 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1985 -- is the only way that Asm_Insn could possibly be visible.
1987 Analyze_And_Resolve (Expression (N));
1989 if Etype (Expression (N)) = Any_Type then
1991 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1992 Error_Msg_N ("incorrect type for code statement", N);
1996 Check_Code_Statement (N);
1998 -- Make sure we appear in the handled statement sequence of a
1999 -- subprogram (RM 13.8(3)).
2001 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2002 or else Nkind (SBody) /= N_Subprogram_Body
2005 ("code statement can only appear in body of subprogram", N);
2009 -- Do remaining checks (RM 13.8(3)) if not already done
2011 if not Is_Machine_Code_Subprogram (Subp) then
2012 Set_Is_Machine_Code_Subprogram (Subp);
2014 -- No exception handlers allowed
2016 if Present (Exception_Handlers (HSS)) then
2018 ("exception handlers not permitted in machine code subprogram",
2019 First (Exception_Handlers (HSS)));
2022 -- No declarations other than use clauses and pragmas (we allow
2023 -- certain internally generated declarations as well).
2025 Decl := First (Declarations (SBody));
2026 while Present (Decl) loop
2027 DeclO := Original_Node (Decl);
2028 if Comes_From_Source (DeclO)
2029 and not Nkind_In (DeclO, N_Pragma,
2030 N_Use_Package_Clause,
2032 N_Implicit_Label_Declaration)
2035 ("this declaration not allowed in machine code subprogram",
2042 -- No statements other than code statements, pragmas, and labels.
2043 -- Again we allow certain internally generated statements.
2045 Stmt := First (Statements (HSS));
2046 while Present (Stmt) loop
2047 StmtO := Original_Node (Stmt);
2048 if Comes_From_Source (StmtO)
2049 and then not Nkind_In (StmtO, N_Pragma,
2054 ("this statement is not allowed in machine code subprogram",
2061 end Analyze_Code_Statement;
2063 -----------------------------------------------
2064 -- Analyze_Enumeration_Representation_Clause --
2065 -----------------------------------------------
2067 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2068 Ident : constant Node_Id := Identifier (N);
2069 Aggr : constant Node_Id := Array_Aggregate (N);
2070 Enumtype : Entity_Id;
2076 Err : Boolean := False;
2078 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2079 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2084 if Ignore_Rep_Clauses then
2088 -- First some basic error checks
2091 Enumtype := Entity (Ident);
2093 if Enumtype = Any_Type
2094 or else Rep_Item_Too_Early (Enumtype, N)
2098 Enumtype := Underlying_Type (Enumtype);
2101 if not Is_Enumeration_Type (Enumtype) then
2103 ("enumeration type required, found}",
2104 Ident, First_Subtype (Enumtype));
2108 -- Ignore rep clause on generic actual type. This will already have
2109 -- been flagged on the template as an error, and this is the safest
2110 -- way to ensure we don't get a junk cascaded message in the instance.
2112 if Is_Generic_Actual_Type (Enumtype) then
2115 -- Type must be in current scope
2117 elsif Scope (Enumtype) /= Current_Scope then
2118 Error_Msg_N ("type must be declared in this scope", Ident);
2121 -- Type must be a first subtype
2123 elsif not Is_First_Subtype (Enumtype) then
2124 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2127 -- Ignore duplicate rep clause
2129 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2130 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2133 -- Don't allow rep clause for standard [wide_[wide_]]character
2135 elsif Is_Standard_Character_Type (Enumtype) then
2136 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2139 -- Check that the expression is a proper aggregate (no parentheses)
2141 elsif Paren_Count (Aggr) /= 0 then
2143 ("extra parentheses surrounding aggregate not allowed",
2147 -- All tests passed, so set rep clause in place
2150 Set_Has_Enumeration_Rep_Clause (Enumtype);
2151 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2154 -- Now we process the aggregate. Note that we don't use the normal
2155 -- aggregate code for this purpose, because we don't want any of the
2156 -- normal expansion activities, and a number of special semantic
2157 -- rules apply (including the component type being any integer type)
2159 Elit := First_Literal (Enumtype);
2161 -- First the positional entries if any
2163 if Present (Expressions (Aggr)) then
2164 Expr := First (Expressions (Aggr));
2165 while Present (Expr) loop
2167 Error_Msg_N ("too many entries in aggregate", Expr);
2171 Val := Static_Integer (Expr);
2173 -- Err signals that we found some incorrect entries processing
2174 -- the list. The final checks for completeness and ordering are
2175 -- skipped in this case.
2177 if Val = No_Uint then
2179 elsif Val < Lo or else Hi < Val then
2180 Error_Msg_N ("value outside permitted range", Expr);
2184 Set_Enumeration_Rep (Elit, Val);
2185 Set_Enumeration_Rep_Expr (Elit, Expr);
2191 -- Now process the named entries if present
2193 if Present (Component_Associations (Aggr)) then
2194 Assoc := First (Component_Associations (Aggr));
2195 while Present (Assoc) loop
2196 Choice := First (Choices (Assoc));
2198 if Present (Next (Choice)) then
2200 ("multiple choice not allowed here", Next (Choice));
2204 if Nkind (Choice) = N_Others_Choice then
2205 Error_Msg_N ("others choice not allowed here", Choice);
2208 elsif Nkind (Choice) = N_Range then
2209 -- ??? should allow zero/one element range here
2210 Error_Msg_N ("range not allowed here", Choice);
2214 Analyze_And_Resolve (Choice, Enumtype);
2216 if Is_Entity_Name (Choice)
2217 and then Is_Type (Entity (Choice))
2219 Error_Msg_N ("subtype name not allowed here", Choice);
2221 -- ??? should allow static subtype with zero/one entry
2223 elsif Etype (Choice) = Base_Type (Enumtype) then
2224 if not Is_Static_Expression (Choice) then
2225 Flag_Non_Static_Expr
2226 ("non-static expression used for choice!", Choice);
2230 Elit := Expr_Value_E (Choice);
2232 if Present (Enumeration_Rep_Expr (Elit)) then
2233 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2235 ("representation for& previously given#",
2240 Set_Enumeration_Rep_Expr (Elit, Choice);
2242 Expr := Expression (Assoc);
2243 Val := Static_Integer (Expr);
2245 if Val = No_Uint then
2248 elsif Val < Lo or else Hi < Val then
2249 Error_Msg_N ("value outside permitted range", Expr);
2253 Set_Enumeration_Rep (Elit, Val);
2262 -- Aggregate is fully processed. Now we check that a full set of
2263 -- representations was given, and that they are in range and in order.
2264 -- These checks are only done if no other errors occurred.
2270 Elit := First_Literal (Enumtype);
2271 while Present (Elit) loop
2272 if No (Enumeration_Rep_Expr (Elit)) then
2273 Error_Msg_NE ("missing representation for&!", N, Elit);
2276 Val := Enumeration_Rep (Elit);
2278 if Min = No_Uint then
2282 if Val /= No_Uint then
2283 if Max /= No_Uint and then Val <= Max then
2285 ("enumeration value for& not ordered!",
2286 Enumeration_Rep_Expr (Elit), Elit);
2292 -- If there is at least one literal whose representation
2293 -- is not equal to the Pos value, then note that this
2294 -- enumeration type has a non-standard representation.
2296 if Val /= Enumeration_Pos (Elit) then
2297 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2304 -- Now set proper size information
2307 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2310 if Has_Size_Clause (Enumtype) then
2311 if Esize (Enumtype) >= Minsize then
2316 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2318 if Esize (Enumtype) < Minsize then
2319 Error_Msg_N ("previously given size is too small", N);
2322 Set_Has_Biased_Representation (Enumtype);
2327 Set_RM_Size (Enumtype, Minsize);
2328 Set_Enum_Esize (Enumtype);
2331 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2332 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2333 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2337 -- We repeat the too late test in case it froze itself!
2339 if Rep_Item_Too_Late (Enumtype, N) then
2342 end Analyze_Enumeration_Representation_Clause;
2344 ----------------------------
2345 -- Analyze_Free_Statement --
2346 ----------------------------
2348 procedure Analyze_Free_Statement (N : Node_Id) is
2350 Analyze (Expression (N));
2351 end Analyze_Free_Statement;
2353 ---------------------------
2354 -- Analyze_Freeze_Entity --
2355 ---------------------------
2357 procedure Analyze_Freeze_Entity (N : Node_Id) is
2358 E : constant Entity_Id := Entity (N);
2360 function Make_Null_Procedure_Specs (Tag_Typ : Entity_Id) return List_Id;
2361 -- Ada 2005 (AI-251): Makes specs for null procedures associated with
2362 -- null procedures inherited from interface types that have not been
2363 -- overridden. Only one null procedure will be created for a given
2364 -- set of inherited null procedures with homographic profiles.
2366 -------------------------------
2367 -- Make_Null_Procedure_Specs --
2368 -------------------------------
2370 function Make_Null_Procedure_Specs (Tag_Typ : Entity_Id) return List_Id
2372 Decl_List : constant List_Id := New_List;
2373 Loc : constant Source_Ptr := Sloc (Tag_Typ);
2375 Formal_List : List_Id;
2376 New_Param_Spec : Node_Id;
2377 Parent_Subp : Entity_Id;
2378 Prim_Elmt : Elmt_Id;
2379 Proc_Decl : Node_Id;
2383 Prim_Elmt := First_Elmt (Primitive_Operations (Tag_Typ));
2384 while Present (Prim_Elmt) loop
2385 Subp := Node (Prim_Elmt);
2387 -- If a null procedure inherited from an interface has not been
2388 -- overridden, then we build a null procedure declaration to
2389 -- override the inherited procedure.
2391 Parent_Subp := Alias (Subp);
2393 if Present (Parent_Subp)
2394 and then Is_Null_Interface_Primitive (Parent_Subp)
2396 Formal_List := No_List;
2397 Formal := First_Formal (Subp);
2399 if Present (Formal) then
2400 Formal_List := New_List;
2402 while Present (Formal) loop
2404 -- Copy the parameter spec including default expressions
2407 New_Copy_Tree (Parent (Formal), New_Sloc => Loc);
2409 -- Generate a new defining identifier for the new formal.
2410 -- required because New_Copy_Tree does not duplicate
2411 -- semantic fields (except itypes).
2413 Set_Defining_Identifier (New_Param_Spec,
2414 Make_Defining_Identifier (Sloc (Formal),
2415 Chars => Chars (Formal)));
2417 -- For controlling arguments we must change their
2418 -- parameter type to reference the tagged type (instead
2419 -- of the interface type)
2421 if Is_Controlling_Formal (Formal) then
2422 if Nkind (Parameter_Type (Parent (Formal)))
2425 Set_Parameter_Type (New_Param_Spec,
2426 New_Occurrence_Of (Tag_Typ, Loc));
2429 (Nkind (Parameter_Type (Parent (Formal)))
2430 = N_Access_Definition);
2431 Set_Subtype_Mark (Parameter_Type (New_Param_Spec),
2432 New_Occurrence_Of (Tag_Typ, Loc));
2436 Append (New_Param_Spec, Formal_List);
2438 Next_Formal (Formal);
2443 Make_Subprogram_Declaration (Loc,
2444 Make_Procedure_Specification (Loc,
2445 Defining_Unit_Name =>
2446 Make_Defining_Identifier (Loc, Chars (Subp)),
2447 Parameter_Specifications => Formal_List,
2448 Null_Present => True));
2449 Append_To (Decl_List, Proc_Decl);
2452 Next_Elmt (Prim_Elmt);
2456 end Make_Null_Procedure_Specs;
2458 -- Start of processing for Analyze_Freeze_Entity
2461 -- For tagged types covering interfaces add internal entities that link
2462 -- the primitives of the interfaces with the primitives that cover them.
2464 -- Note: These entities were originally generated only when generating
2465 -- code because their main purpose was to provide support to initialize
2466 -- the secondary dispatch tables. They are now generated also when
2467 -- compiling with no code generation to provide ASIS the relationship
2468 -- between interface primitives and tagged type primitives. They are
2469 -- also used to locate primitives covering interfaces when processing
2470 -- generics (see Derive_Subprograms).
2472 if Ada_Version >= Ada_05
2473 and then Ekind (E) = E_Record_Type
2474 and then Is_Tagged_Type (E)
2475 and then not Is_Interface (E)
2476 and then Has_Interfaces (E)
2478 -- Add specs of non-overridden null interface primitives. During
2479 -- semantic analysis this is required to ensure consistency of the
2480 -- contents of the list of primitives of the tagged type. Routine
2481 -- Add_Internal_Interface_Entities will take care of adding to such
2482 -- list the internal entities that link each interface primitive with
2483 -- the primitive of Tagged_Type that covers it; hence these specs
2484 -- must be added before invoking Add_Internal_Interface_Entities.
2485 -- In the expansion this consistency is required to ensure that the
2486 -- dispatch table slots associated with non-overridden null interface
2487 -- primitives are properly filled.
2489 if not Is_Abstract_Type (E) then
2490 Insert_Actions (N, Make_Null_Procedure_Specs (E));
2493 -- This would be a good common place to call the routine that checks
2494 -- overriding of interface primitives (and thus factorize calls to
2495 -- Check_Abstract_Overriding located at different contexts in the
2496 -- compiler). However, this is not possible because it causes
2497 -- spurious errors in case of late overriding.
2499 Add_Internal_Interface_Entities (E);
2504 if Ekind (E) = E_Record_Type
2505 and then Is_CPP_Class (E)
2506 and then Is_Tagged_Type (E)
2507 and then Tagged_Type_Expansion
2508 and then Expander_Active
2510 if CPP_Num_Prims (E) = 0 then
2512 -- If the CPP type has user defined components then it must import
2513 -- primitives from C++. This is required because if the C++ class
2514 -- has no primitives then the C++ compiler does not added the _tag
2515 -- component to the type.
2517 pragma Assert (Chars (First_Entity (E)) = Name_uTag);
2519 if First_Entity (E) /= Last_Entity (E) then
2521 ("?'C'P'P type must import at least one primitive from C++",
2526 -- Check that all its primitives are abstract or imported from C++.
2527 -- Check also availability of the C++ constructor.
2530 Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
2532 Error_Reported : Boolean := False;
2536 Elmt := First_Elmt (Primitive_Operations (E));
2537 while Present (Elmt) loop
2538 Prim := Node (Elmt);
2540 if Comes_From_Source (Prim) then
2541 if Is_Abstract_Subprogram (Prim) then
2544 elsif not Is_Imported (Prim)
2545 or else Convention (Prim) /= Convention_CPP
2548 ("?primitives of 'C'P'P types must be imported from C++"
2549 & " or abstract", Prim);
2551 elsif not Has_Constructors
2552 and then not Error_Reported
2554 Error_Msg_Name_1 := Chars (E);
2556 ("?'C'P'P constructor required for type %", Prim);
2557 Error_Reported := True;
2565 end Analyze_Freeze_Entity;
2567 ------------------------------------------
2568 -- Analyze_Record_Representation_Clause --
2569 ------------------------------------------
2571 -- Note: we check as much as we can here, but we can't do any checks
2572 -- based on the position values (e.g. overlap checks) until freeze time
2573 -- because especially in Ada 2005 (machine scalar mode), the processing
2574 -- for non-standard bit order can substantially change the positions.
2575 -- See procedure Check_Record_Representation_Clause (called from Freeze)
2576 -- for the remainder of this processing.
2578 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2579 Ident : constant Node_Id := Identifier (N);
2580 Rectype : Entity_Id;
2585 Hbit : Uint := Uint_0;
2590 CR_Pragma : Node_Id := Empty;
2591 -- Points to N_Pragma node if Complete_Representation pragma present
2594 if Ignore_Rep_Clauses then
2599 Rectype := Entity (Ident);
2601 if Rectype = Any_Type
2602 or else Rep_Item_Too_Early (Rectype, N)
2606 Rectype := Underlying_Type (Rectype);
2609 -- First some basic error checks
2611 if not Is_Record_Type (Rectype) then
2613 ("record type required, found}", Ident, First_Subtype (Rectype));
2616 elsif Is_Unchecked_Union (Rectype) then
2618 ("record rep clause not allowed for Unchecked_Union", N);
2620 elsif Scope (Rectype) /= Current_Scope then
2621 Error_Msg_N ("type must be declared in this scope", N);
2624 elsif not Is_First_Subtype (Rectype) then
2625 Error_Msg_N ("cannot give record rep clause for subtype", N);
2628 elsif Has_Record_Rep_Clause (Rectype) then
2629 Error_Msg_N ("duplicate record rep clause ignored", N);
2632 elsif Rep_Item_Too_Late (Rectype, N) then
2636 if Present (Mod_Clause (N)) then
2638 Loc : constant Source_Ptr := Sloc (N);
2639 M : constant Node_Id := Mod_Clause (N);
2640 P : constant List_Id := Pragmas_Before (M);
2644 pragma Warnings (Off, Mod_Val);
2647 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2649 if Warn_On_Obsolescent_Feature then
2651 ("mod clause is an obsolescent feature (RM J.8)?", N);
2653 ("\use alignment attribute definition clause instead?", N);
2660 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2661 -- the Mod clause into an alignment clause anyway, so that the
2662 -- back-end can compute and back-annotate properly the size and
2663 -- alignment of types that may include this record.
2665 -- This seems dubious, this destroys the source tree in a manner
2666 -- not detectable by ASIS ???
2668 if Operating_Mode = Check_Semantics
2672 Make_Attribute_Definition_Clause (Loc,
2673 Name => New_Reference_To (Base_Type (Rectype), Loc),
2674 Chars => Name_Alignment,
2675 Expression => Relocate_Node (Expression (M)));
2677 Set_From_At_Mod (AtM_Nod);
2678 Insert_After (N, AtM_Nod);
2679 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2680 Set_Mod_Clause (N, Empty);
2683 -- Get the alignment value to perform error checking
2685 Mod_Val := Get_Alignment_Value (Expression (M));
2690 -- For untagged types, clear any existing component clauses for the
2691 -- type. If the type is derived, this is what allows us to override
2692 -- a rep clause for the parent. For type extensions, the representation
2693 -- of the inherited components is inherited, so we want to keep previous
2694 -- component clauses for completeness.
2696 if not Is_Tagged_Type (Rectype) then
2697 Comp := First_Component_Or_Discriminant (Rectype);
2698 while Present (Comp) loop
2699 Set_Component_Clause (Comp, Empty);
2700 Next_Component_Or_Discriminant (Comp);
2704 -- All done if no component clauses
2706 CC := First (Component_Clauses (N));
2712 -- A representation like this applies to the base type
2714 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2715 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2716 Set_Has_Specified_Layout (Base_Type (Rectype));
2718 -- Process the component clauses
2720 while Present (CC) loop
2724 if Nkind (CC) = N_Pragma then
2727 -- The only pragma of interest is Complete_Representation
2729 if Pragma_Name (CC) = Name_Complete_Representation then
2733 -- Processing for real component clause
2736 Posit := Static_Integer (Position (CC));
2737 Fbit := Static_Integer (First_Bit (CC));
2738 Lbit := Static_Integer (Last_Bit (CC));
2741 and then Fbit /= No_Uint
2742 and then Lbit /= No_Uint
2746 ("position cannot be negative", Position (CC));
2750 ("first bit cannot be negative", First_Bit (CC));
2752 -- The Last_Bit specified in a component clause must not be
2753 -- less than the First_Bit minus one (RM-13.5.1(10)).
2755 elsif Lbit < Fbit - 1 then
2757 ("last bit cannot be less than first bit minus one",
2760 -- Values look OK, so find the corresponding record component
2761 -- Even though the syntax allows an attribute reference for
2762 -- implementation-defined components, GNAT does not allow the
2763 -- tag to get an explicit position.
2765 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2766 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2767 Error_Msg_N ("position of tag cannot be specified", CC);
2769 Error_Msg_N ("illegal component name", CC);
2773 Comp := First_Entity (Rectype);
2774 while Present (Comp) loop
2775 exit when Chars (Comp) = Chars (Component_Name (CC));
2781 -- Maybe component of base type that is absent from
2782 -- statically constrained first subtype.
2784 Comp := First_Entity (Base_Type (Rectype));
2785 while Present (Comp) loop
2786 exit when Chars (Comp) = Chars (Component_Name (CC));
2793 ("component clause is for non-existent field", CC);
2795 elsif Present (Component_Clause (Comp)) then
2797 -- Diagnose duplicate rep clause, or check consistency
2798 -- if this is an inherited component. In a double fault,
2799 -- there may be a duplicate inconsistent clause for an
2800 -- inherited component.
2802 if Scope (Original_Record_Component (Comp)) = Rectype
2803 or else Parent (Component_Clause (Comp)) = N
2805 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2806 Error_Msg_N ("component clause previously given#", CC);
2810 Rep1 : constant Node_Id := Component_Clause (Comp);
2812 if Intval (Position (Rep1)) /=
2813 Intval (Position (CC))
2814 or else Intval (First_Bit (Rep1)) /=
2815 Intval (First_Bit (CC))
2816 or else Intval (Last_Bit (Rep1)) /=
2817 Intval (Last_Bit (CC))
2819 Error_Msg_N ("component clause inconsistent "
2820 & "with representation of ancestor", CC);
2821 elsif Warn_On_Redundant_Constructs then
2822 Error_Msg_N ("?redundant component clause "
2823 & "for inherited component!", CC);
2828 -- Normal case where this is the first component clause we
2829 -- have seen for this entity, so set it up properly.
2832 -- Make reference for field in record rep clause and set
2833 -- appropriate entity field in the field identifier.
2836 (Comp, Component_Name (CC), Set_Ref => False);
2837 Set_Entity (Component_Name (CC), Comp);
2839 -- Update Fbit and Lbit to the actual bit number
2841 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2842 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2844 if Has_Size_Clause (Rectype)
2845 and then Esize (Rectype) <= Lbit
2848 ("bit number out of range of specified size",
2851 Set_Component_Clause (Comp, CC);
2852 Set_Component_Bit_Offset (Comp, Fbit);
2853 Set_Esize (Comp, 1 + (Lbit - Fbit));
2854 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2855 Set_Normalized_Position (Comp, Fbit / SSU);
2857 -- This information is also set in the corresponding
2858 -- component of the base type, found by accessing the
2859 -- Original_Record_Component link if it is present.
2861 Ocomp := Original_Record_Component (Comp);
2868 (Component_Name (CC),
2873 Set_Has_Biased_Representation (Comp, Biased);
2875 if Biased and Warn_On_Biased_Representation then
2877 ("?component clause forces biased "
2878 & "representation", CC);
2881 if Present (Ocomp) then
2882 Set_Component_Clause (Ocomp, CC);
2883 Set_Component_Bit_Offset (Ocomp, Fbit);
2884 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2885 Set_Normalized_Position (Ocomp, Fbit / SSU);
2886 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2888 Set_Normalized_Position_Max
2889 (Ocomp, Normalized_Position (Ocomp));
2891 Set_Has_Biased_Representation
2892 (Ocomp, Has_Biased_Representation (Comp));
2895 if Esize (Comp) < 0 then
2896 Error_Msg_N ("component size is negative", CC);
2907 -- Check missing components if Complete_Representation pragma appeared
2909 if Present (CR_Pragma) then
2910 Comp := First_Component_Or_Discriminant (Rectype);
2911 while Present (Comp) loop
2912 if No (Component_Clause (Comp)) then
2914 ("missing component clause for &", CR_Pragma, Comp);
2917 Next_Component_Or_Discriminant (Comp);
2920 -- If no Complete_Representation pragma, warn if missing components
2922 elsif Warn_On_Unrepped_Components then
2924 Num_Repped_Components : Nat := 0;
2925 Num_Unrepped_Components : Nat := 0;
2928 -- First count number of repped and unrepped components
2930 Comp := First_Component_Or_Discriminant (Rectype);
2931 while Present (Comp) loop
2932 if Present (Component_Clause (Comp)) then
2933 Num_Repped_Components := Num_Repped_Components + 1;
2935 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2938 Next_Component_Or_Discriminant (Comp);
2941 -- We are only interested in the case where there is at least one
2942 -- unrepped component, and at least half the components have rep
2943 -- clauses. We figure that if less than half have them, then the
2944 -- partial rep clause is really intentional. If the component
2945 -- type has no underlying type set at this point (as for a generic
2946 -- formal type), we don't know enough to give a warning on the
2949 if Num_Unrepped_Components > 0
2950 and then Num_Unrepped_Components < Num_Repped_Components
2952 Comp := First_Component_Or_Discriminant (Rectype);
2953 while Present (Comp) loop
2954 if No (Component_Clause (Comp))
2955 and then Comes_From_Source (Comp)
2956 and then Present (Underlying_Type (Etype (Comp)))
2957 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2958 or else Size_Known_At_Compile_Time
2959 (Underlying_Type (Etype (Comp))))
2960 and then not Has_Warnings_Off (Rectype)
2962 Error_Msg_Sloc := Sloc (Comp);
2964 ("?no component clause given for & declared #",
2968 Next_Component_Or_Discriminant (Comp);
2973 end Analyze_Record_Representation_Clause;
2975 -----------------------------------
2976 -- Check_Constant_Address_Clause --
2977 -----------------------------------
2979 procedure Check_Constant_Address_Clause
2983 procedure Check_At_Constant_Address (Nod : Node_Id);
2984 -- Checks that the given node N represents a name whose 'Address is
2985 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2986 -- address value is the same at the point of declaration of U_Ent and at
2987 -- the time of elaboration of the address clause.
2989 procedure Check_Expr_Constants (Nod : Node_Id);
2990 -- Checks that Nod meets the requirements for a constant address clause
2991 -- in the sense of the enclosing procedure.
2993 procedure Check_List_Constants (Lst : List_Id);
2994 -- Check that all elements of list Lst meet the requirements for a
2995 -- constant address clause in the sense of the enclosing procedure.
2997 -------------------------------
2998 -- Check_At_Constant_Address --
2999 -------------------------------
3001 procedure Check_At_Constant_Address (Nod : Node_Id) is
3003 if Is_Entity_Name (Nod) then
3004 if Present (Address_Clause (Entity ((Nod)))) then
3006 ("invalid address clause for initialized object &!",
3009 ("address for& cannot" &
3010 " depend on another address clause! (RM 13.1(22))!",
3013 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
3014 and then Sloc (U_Ent) < Sloc (Entity (Nod))
3017 ("invalid address clause for initialized object &!",
3019 Error_Msg_Node_2 := U_Ent;
3021 ("\& must be defined before & (RM 13.1(22))!",
3025 elsif Nkind (Nod) = N_Selected_Component then
3027 T : constant Entity_Id := Etype (Prefix (Nod));
3030 if (Is_Record_Type (T)
3031 and then Has_Discriminants (T))
3034 and then Is_Record_Type (Designated_Type (T))
3035 and then Has_Discriminants (Designated_Type (T)))
3038 ("invalid address clause for initialized object &!",
3041 ("\address cannot depend on component" &
3042 " of discriminated record (RM 13.1(22))!",
3045 Check_At_Constant_Address (Prefix (Nod));
3049 elsif Nkind (Nod) = N_Indexed_Component then
3050 Check_At_Constant_Address (Prefix (Nod));
3051 Check_List_Constants (Expressions (Nod));
3054 Check_Expr_Constants (Nod);
3056 end Check_At_Constant_Address;
3058 --------------------------
3059 -- Check_Expr_Constants --
3060 --------------------------
3062 procedure Check_Expr_Constants (Nod : Node_Id) is
3063 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
3064 Ent : Entity_Id := Empty;
3067 if Nkind (Nod) in N_Has_Etype
3068 and then Etype (Nod) = Any_Type
3074 when N_Empty | N_Error =>
3077 when N_Identifier | N_Expanded_Name =>
3078 Ent := Entity (Nod);
3080 -- We need to look at the original node if it is different
3081 -- from the node, since we may have rewritten things and
3082 -- substituted an identifier representing the rewrite.
3084 if Original_Node (Nod) /= Nod then
3085 Check_Expr_Constants (Original_Node (Nod));
3087 -- If the node is an object declaration without initial
3088 -- value, some code has been expanded, and the expression
3089 -- is not constant, even if the constituents might be
3090 -- acceptable, as in A'Address + offset.
3092 if Ekind (Ent) = E_Variable
3094 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3096 No (Expression (Declaration_Node (Ent)))
3099 ("invalid address clause for initialized object &!",
3102 -- If entity is constant, it may be the result of expanding
3103 -- a check. We must verify that its declaration appears
3104 -- before the object in question, else we also reject the
3107 elsif Ekind (Ent) = E_Constant
3108 and then In_Same_Source_Unit (Ent, U_Ent)
3109 and then Sloc (Ent) > Loc_U_Ent
3112 ("invalid address clause for initialized object &!",
3119 -- Otherwise look at the identifier and see if it is OK
3121 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
3122 or else Is_Type (Ent)
3127 Ekind (Ent) = E_Constant
3129 Ekind (Ent) = E_In_Parameter
3131 -- This is the case where we must have Ent defined before
3132 -- U_Ent. Clearly if they are in different units this
3133 -- requirement is met since the unit containing Ent is
3134 -- already processed.
3136 if not In_Same_Source_Unit (Ent, U_Ent) then
3139 -- Otherwise location of Ent must be before the location
3140 -- of U_Ent, that's what prior defined means.
3142 elsif Sloc (Ent) < Loc_U_Ent then
3147 ("invalid address clause for initialized object &!",
3149 Error_Msg_Node_2 := U_Ent;
3151 ("\& must be defined before & (RM 13.1(22))!",
3155 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3156 Check_Expr_Constants (Original_Node (Nod));
3160 ("invalid address clause for initialized object &!",
3163 if Comes_From_Source (Ent) then
3165 ("\reference to variable& not allowed"
3166 & " (RM 13.1(22))!", Nod, Ent);
3169 ("non-static expression not allowed"
3170 & " (RM 13.1(22))!", Nod);
3174 when N_Integer_Literal =>
3176 -- If this is a rewritten unchecked conversion, in a system
3177 -- where Address is an integer type, always use the base type
3178 -- for a literal value. This is user-friendly and prevents
3179 -- order-of-elaboration issues with instances of unchecked
3182 if Nkind (Original_Node (Nod)) = N_Function_Call then
3183 Set_Etype (Nod, Base_Type (Etype (Nod)));
3186 when N_Real_Literal |
3188 N_Character_Literal =>
3192 Check_Expr_Constants (Low_Bound (Nod));
3193 Check_Expr_Constants (High_Bound (Nod));
3195 when N_Explicit_Dereference =>
3196 Check_Expr_Constants (Prefix (Nod));
3198 when N_Indexed_Component =>
3199 Check_Expr_Constants (Prefix (Nod));
3200 Check_List_Constants (Expressions (Nod));
3203 Check_Expr_Constants (Prefix (Nod));
3204 Check_Expr_Constants (Discrete_Range (Nod));
3206 when N_Selected_Component =>
3207 Check_Expr_Constants (Prefix (Nod));
3209 when N_Attribute_Reference =>
3210 if Attribute_Name (Nod) = Name_Address
3212 Attribute_Name (Nod) = Name_Access
3214 Attribute_Name (Nod) = Name_Unchecked_Access
3216 Attribute_Name (Nod) = Name_Unrestricted_Access
3218 Check_At_Constant_Address (Prefix (Nod));
3221 Check_Expr_Constants (Prefix (Nod));
3222 Check_List_Constants (Expressions (Nod));
3226 Check_List_Constants (Component_Associations (Nod));
3227 Check_List_Constants (Expressions (Nod));
3229 when N_Component_Association =>
3230 Check_Expr_Constants (Expression (Nod));
3232 when N_Extension_Aggregate =>
3233 Check_Expr_Constants (Ancestor_Part (Nod));
3234 Check_List_Constants (Component_Associations (Nod));
3235 Check_List_Constants (Expressions (Nod));
3240 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3241 Check_Expr_Constants (Left_Opnd (Nod));
3242 Check_Expr_Constants (Right_Opnd (Nod));
3245 Check_Expr_Constants (Right_Opnd (Nod));
3247 when N_Type_Conversion |
3248 N_Qualified_Expression |
3250 Check_Expr_Constants (Expression (Nod));
3252 when N_Unchecked_Type_Conversion =>
3253 Check_Expr_Constants (Expression (Nod));
3255 -- If this is a rewritten unchecked conversion, subtypes in
3256 -- this node are those created within the instance. To avoid
3257 -- order of elaboration issues, replace them with their base
3258 -- types. Note that address clauses can cause order of
3259 -- elaboration problems because they are elaborated by the
3260 -- back-end at the point of definition, and may mention
3261 -- entities declared in between (as long as everything is
3262 -- static). It is user-friendly to allow unchecked conversions
3265 if Nkind (Original_Node (Nod)) = N_Function_Call then
3266 Set_Etype (Expression (Nod),
3267 Base_Type (Etype (Expression (Nod))));
3268 Set_Etype (Nod, Base_Type (Etype (Nod)));
3271 when N_Function_Call =>
3272 if not Is_Pure (Entity (Name (Nod))) then
3274 ("invalid address clause for initialized object &!",
3278 ("\function & is not pure (RM 13.1(22))!",
3279 Nod, Entity (Name (Nod)));
3282 Check_List_Constants (Parameter_Associations (Nod));
3285 when N_Parameter_Association =>
3286 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3290 ("invalid address clause for initialized object &!",
3293 ("\must be constant defined before& (RM 13.1(22))!",
3296 end Check_Expr_Constants;
3298 --------------------------
3299 -- Check_List_Constants --
3300 --------------------------
3302 procedure Check_List_Constants (Lst : List_Id) is
3306 if Present (Lst) then
3307 Nod1 := First (Lst);
3308 while Present (Nod1) loop
3309 Check_Expr_Constants (Nod1);
3313 end Check_List_Constants;
3315 -- Start of processing for Check_Constant_Address_Clause
3318 -- If rep_clauses are to be ignored, no need for legality checks. In
3319 -- particular, no need to pester user about rep clauses that violate
3320 -- the rule on constant addresses, given that these clauses will be
3321 -- removed by Freeze before they reach the back end.
3323 if not Ignore_Rep_Clauses then
3324 Check_Expr_Constants (Expr);
3326 end Check_Constant_Address_Clause;
3328 ----------------------------------------
3329 -- Check_Record_Representation_Clause --
3330 ----------------------------------------
3332 procedure Check_Record_Representation_Clause (N : Node_Id) is
3333 Loc : constant Source_Ptr := Sloc (N);
3334 Ident : constant Node_Id := Identifier (N);
3335 Rectype : Entity_Id;
3340 Hbit : Uint := Uint_0;
3344 Max_Bit_So_Far : Uint;
3345 -- Records the maximum bit position so far. If all field positions
3346 -- are monotonically increasing, then we can skip the circuit for
3347 -- checking for overlap, since no overlap is possible.
3349 Tagged_Parent : Entity_Id := Empty;
3350 -- This is set in the case of a derived tagged type for which we have
3351 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
3352 -- positioned by record representation clauses). In this case we must
3353 -- check for overlap between components of this tagged type, and the
3354 -- components of its parent. Tagged_Parent will point to this parent
3355 -- type. For all other cases Tagged_Parent is left set to Empty.
3357 Parent_Last_Bit : Uint;
3358 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
3359 -- last bit position for any field in the parent type. We only need to
3360 -- check overlap for fields starting below this point.
3362 Overlap_Check_Required : Boolean;
3363 -- Used to keep track of whether or not an overlap check is required
3365 Ccount : Natural := 0;
3366 -- Number of component clauses in record rep clause
3368 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
3369 -- Given two entities for record components or discriminants, checks
3370 -- if they have overlapping component clauses and issues errors if so.
3372 procedure Find_Component;
3373 -- Finds component entity corresponding to current component clause (in
3374 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
3375 -- start/stop bits for the field. If there is no matching component or
3376 -- if the matching component does not have a component clause, then
3377 -- that's an error and Comp is set to Empty, but no error message is
3378 -- issued, since the message was already given. Comp is also set to
3379 -- Empty if the current "component clause" is in fact a pragma.
3381 -----------------------------
3382 -- Check_Component_Overlap --
3383 -----------------------------
3385 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
3386 CC1 : constant Node_Id := Component_Clause (C1_Ent);
3387 CC2 : constant Node_Id := Component_Clause (C2_Ent);
3389 if Present (CC1) and then Present (CC2) then
3391 -- Exclude odd case where we have two tag fields in the same
3392 -- record, both at location zero. This seems a bit strange, but
3393 -- it seems to happen in some circumstances, perhaps on an error.
3395 if Chars (C1_Ent) = Name_uTag
3397 Chars (C2_Ent) = Name_uTag
3402 -- Here we check if the two fields overlap
3405 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
3406 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
3407 E1 : constant Uint := S1 + Esize (C1_Ent);
3408 E2 : constant Uint := S2 + Esize (C2_Ent);
3411 if E2 <= S1 or else E1 <= S2 then
3414 Error_Msg_Node_2 := Component_Name (CC2);
3415 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
3416 Error_Msg_Node_1 := Component_Name (CC1);
3418 ("component& overlaps & #", Component_Name (CC1));
3422 end Check_Component_Overlap;
3424 --------------------
3425 -- Find_Component --
3426 --------------------
3428 procedure Find_Component is
3430 procedure Search_Component (R : Entity_Id);
3431 -- Search components of R for a match. If found, Comp is set.
3433 ----------------------
3434 -- Search_Component --
3435 ----------------------
3437 procedure Search_Component (R : Entity_Id) is
3439 Comp := First_Component_Or_Discriminant (R);
3440 while Present (Comp) loop
3442 -- Ignore error of attribute name for component name (we
3443 -- already gave an error message for this, so no need to
3446 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
3449 exit when Chars (Comp) = Chars (Component_Name (CC));
3452 Next_Component_Or_Discriminant (Comp);
3454 end Search_Component;
3456 -- Start of processing for Find_Component
3459 -- Return with Comp set to Empty if we have a pragma
3461 if Nkind (CC) = N_Pragma then
3466 -- Search current record for matching component
3468 Search_Component (Rectype);
3470 -- If not found, maybe component of base type that is absent from
3471 -- statically constrained first subtype.
3474 Search_Component (Base_Type (Rectype));
3477 -- If no component, or the component does not reference the component
3478 -- clause in question, then there was some previous error for which
3479 -- we already gave a message, so just return with Comp Empty.
3482 or else Component_Clause (Comp) /= CC
3486 -- Normal case where we have a component clause
3489 Fbit := Component_Bit_Offset (Comp);
3490 Lbit := Fbit + Esize (Comp) - 1;
3494 -- Start of processing for Check_Record_Representation_Clause
3498 Rectype := Entity (Ident);
3500 if Rectype = Any_Type then
3503 Rectype := Underlying_Type (Rectype);
3506 -- See if we have a fully repped derived tagged type
3509 PS : constant Entity_Id := Parent_Subtype (Rectype);
3512 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
3513 Tagged_Parent := PS;
3515 -- Find maximum bit of any component of the parent type
3517 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
3518 Pcomp := First_Entity (Tagged_Parent);
3519 while Present (Pcomp) loop
3520 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
3521 if Component_Bit_Offset (Pcomp) /= No_Uint
3522 and then Known_Static_Esize (Pcomp)
3527 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
3530 Next_Entity (Pcomp);
3536 -- All done if no component clauses
3538 CC := First (Component_Clauses (N));
3544 -- If a tag is present, then create a component clause that places it
3545 -- at the start of the record (otherwise gigi may place it after other
3546 -- fields that have rep clauses).
3548 Fent := First_Entity (Rectype);
3550 if Nkind (Fent) = N_Defining_Identifier
3551 and then Chars (Fent) = Name_uTag
3553 Set_Component_Bit_Offset (Fent, Uint_0);
3554 Set_Normalized_Position (Fent, Uint_0);
3555 Set_Normalized_First_Bit (Fent, Uint_0);
3556 Set_Normalized_Position_Max (Fent, Uint_0);
3557 Init_Esize (Fent, System_Address_Size);
3559 Set_Component_Clause (Fent,
3560 Make_Component_Clause (Loc,
3562 Make_Identifier (Loc,
3563 Chars => Name_uTag),
3566 Make_Integer_Literal (Loc,
3570 Make_Integer_Literal (Loc,
3574 Make_Integer_Literal (Loc,
3575 UI_From_Int (System_Address_Size))));
3577 Ccount := Ccount + 1;
3580 Max_Bit_So_Far := Uint_Minus_1;
3581 Overlap_Check_Required := False;
3583 -- Process the component clauses
3585 while Present (CC) loop
3588 if Present (Comp) then
3589 Ccount := Ccount + 1;
3591 if Fbit <= Max_Bit_So_Far then
3592 Overlap_Check_Required := True;
3594 Max_Bit_So_Far := Lbit;
3597 -- Check bit position out of range of specified size
3599 if Has_Size_Clause (Rectype)
3600 and then Esize (Rectype) <= Lbit
3603 ("bit number out of range of specified size",
3606 -- Check for overlap with tag field
3609 if Is_Tagged_Type (Rectype)
3610 and then Fbit < System_Address_Size
3613 ("component overlaps tag field of&",
3614 Component_Name (CC), Rectype);
3622 -- Check parent overlap if component might overlap parent field
3624 if Present (Tagged_Parent)
3625 and then Fbit <= Parent_Last_Bit
3627 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
3628 while Present (Pcomp) loop
3629 if not Is_Tag (Pcomp)
3630 and then Chars (Pcomp) /= Name_uParent
3632 Check_Component_Overlap (Comp, Pcomp);
3635 Next_Component_Or_Discriminant (Pcomp);
3643 -- Now that we have processed all the component clauses, check for
3644 -- overlap. We have to leave this till last, since the components can
3645 -- appear in any arbitrary order in the representation clause.
3647 -- We do not need this check if all specified ranges were monotonic,
3648 -- as recorded by Overlap_Check_Required being False at this stage.
3650 -- This first section checks if there are any overlapping entries at
3651 -- all. It does this by sorting all entries and then seeing if there are
3652 -- any overlaps. If there are none, then that is decisive, but if there
3653 -- are overlaps, they may still be OK (they may result from fields in
3654 -- different variants).
3656 if Overlap_Check_Required then
3657 Overlap_Check1 : declare
3659 OC_Fbit : array (0 .. Ccount) of Uint;
3660 -- First-bit values for component clauses, the value is the offset
3661 -- of the first bit of the field from start of record. The zero
3662 -- entry is for use in sorting.
3664 OC_Lbit : array (0 .. Ccount) of Uint;
3665 -- Last-bit values for component clauses, the value is the offset
3666 -- of the last bit of the field from start of record. The zero
3667 -- entry is for use in sorting.
3669 OC_Count : Natural := 0;
3670 -- Count of entries in OC_Fbit and OC_Lbit
3672 function OC_Lt (Op1, Op2 : Natural) return Boolean;
3673 -- Compare routine for Sort
3675 procedure OC_Move (From : Natural; To : Natural);
3676 -- Move routine for Sort
3678 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
3684 function OC_Lt (Op1, Op2 : Natural) return Boolean is
3686 return OC_Fbit (Op1) < OC_Fbit (Op2);
3693 procedure OC_Move (From : Natural; To : Natural) is
3695 OC_Fbit (To) := OC_Fbit (From);
3696 OC_Lbit (To) := OC_Lbit (From);
3699 -- Start of processing for Overlap_Check
3702 CC := First (Component_Clauses (N));
3703 while Present (CC) loop
3705 -- Exclude component clause already marked in error
3707 if not Error_Posted (CC) then
3710 if Present (Comp) then
3711 OC_Count := OC_Count + 1;
3712 OC_Fbit (OC_Count) := Fbit;
3713 OC_Lbit (OC_Count) := Lbit;
3720 Sorting.Sort (OC_Count);
3722 Overlap_Check_Required := False;
3723 for J in 1 .. OC_Count - 1 loop
3724 if OC_Lbit (J) >= OC_Fbit (J + 1) then
3725 Overlap_Check_Required := True;
3732 -- If Overlap_Check_Required is still True, then we have to do the full
3733 -- scale overlap check, since we have at least two fields that do
3734 -- overlap, and we need to know if that is OK since they are in
3735 -- different variant, or whether we have a definite problem.
3737 if Overlap_Check_Required then
3738 Overlap_Check2 : declare
3739 C1_Ent, C2_Ent : Entity_Id;
3740 -- Entities of components being checked for overlap
3743 -- Component_List node whose Component_Items are being checked
3746 -- Component declaration for component being checked
3749 C1_Ent := First_Entity (Base_Type (Rectype));
3751 -- Loop through all components in record. For each component check
3752 -- for overlap with any of the preceding elements on the component
3753 -- list containing the component and also, if the component is in
3754 -- a variant, check against components outside the case structure.
3755 -- This latter test is repeated recursively up the variant tree.
3757 Main_Component_Loop : while Present (C1_Ent) loop
3758 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
3759 goto Continue_Main_Component_Loop;
3762 -- Skip overlap check if entity has no declaration node. This
3763 -- happens with discriminants in constrained derived types.
3764 -- Probably we are missing some checks as a result, but that
3765 -- does not seem terribly serious ???
3767 if No (Declaration_Node (C1_Ent)) then
3768 goto Continue_Main_Component_Loop;
3771 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
3773 -- Loop through component lists that need checking. Check the
3774 -- current component list and all lists in variants above us.
3776 Component_List_Loop : loop
3778 -- If derived type definition, go to full declaration
3779 -- If at outer level, check discriminants if there are any.
3781 if Nkind (Clist) = N_Derived_Type_Definition then
3782 Clist := Parent (Clist);
3785 -- Outer level of record definition, check discriminants
3787 if Nkind_In (Clist, N_Full_Type_Declaration,
3788 N_Private_Type_Declaration)
3790 if Has_Discriminants (Defining_Identifier (Clist)) then
3792 First_Discriminant (Defining_Identifier (Clist));
3793 while Present (C2_Ent) loop
3794 exit when C1_Ent = C2_Ent;
3795 Check_Component_Overlap (C1_Ent, C2_Ent);
3796 Next_Discriminant (C2_Ent);
3800 -- Record extension case
3802 elsif Nkind (Clist) = N_Derived_Type_Definition then
3805 -- Otherwise check one component list
3808 Citem := First (Component_Items (Clist));
3810 while Present (Citem) loop
3811 if Nkind (Citem) = N_Component_Declaration then
3812 C2_Ent := Defining_Identifier (Citem);
3813 exit when C1_Ent = C2_Ent;
3814 Check_Component_Overlap (C1_Ent, C2_Ent);
3821 -- Check for variants above us (the parent of the Clist can
3822 -- be a variant, in which case its parent is a variant part,
3823 -- and the parent of the variant part is a component list
3824 -- whose components must all be checked against the current
3825 -- component for overlap).
3827 if Nkind (Parent (Clist)) = N_Variant then
3828 Clist := Parent (Parent (Parent (Clist)));
3830 -- Check for possible discriminant part in record, this
3831 -- is treated essentially as another level in the
3832 -- recursion. For this case the parent of the component
3833 -- list is the record definition, and its parent is the
3834 -- full type declaration containing the discriminant
3837 elsif Nkind (Parent (Clist)) = N_Record_Definition then
3838 Clist := Parent (Parent ((Clist)));
3840 -- If neither of these two cases, we are at the top of
3844 exit Component_List_Loop;
3846 end loop Component_List_Loop;
3848 <<Continue_Main_Component_Loop>>
3849 Next_Entity (C1_Ent);
3851 end loop Main_Component_Loop;
3855 -- For records that have component clauses for all components, and whose
3856 -- size is less than or equal to 32, we need to know the size in the
3857 -- front end to activate possible packed array processing where the
3858 -- component type is a record.
3860 -- At this stage Hbit + 1 represents the first unused bit from all the
3861 -- component clauses processed, so if the component clauses are
3862 -- complete, then this is the length of the record.
3864 -- For records longer than System.Storage_Unit, and for those where not
3865 -- all components have component clauses, the back end determines the
3866 -- length (it may for example be appropriate to round up the size
3867 -- to some convenient boundary, based on alignment considerations, etc).
3869 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
3871 -- Nothing to do if at least one component has no component clause
3873 Comp := First_Component_Or_Discriminant (Rectype);
3874 while Present (Comp) loop
3875 exit when No (Component_Clause (Comp));
3876 Next_Component_Or_Discriminant (Comp);
3879 -- If we fall out of loop, all components have component clauses
3880 -- and so we can set the size to the maximum value.
3883 Set_RM_Size (Rectype, Hbit + 1);
3886 end Check_Record_Representation_Clause;
3892 procedure Check_Size
3896 Biased : out Boolean)
3898 UT : constant Entity_Id := Underlying_Type (T);
3904 -- Dismiss cases for generic types or types with previous errors
3907 or else UT = Any_Type
3908 or else Is_Generic_Type (UT)
3909 or else Is_Generic_Type (Root_Type (UT))
3913 -- Check case of bit packed array
3915 elsif Is_Array_Type (UT)
3916 and then Known_Static_Component_Size (UT)
3917 and then Is_Bit_Packed_Array (UT)
3925 Asiz := Component_Size (UT);
3926 Indx := First_Index (UT);
3928 Ityp := Etype (Indx);
3930 -- If non-static bound, then we are not in the business of
3931 -- trying to check the length, and indeed an error will be
3932 -- issued elsewhere, since sizes of non-static array types
3933 -- cannot be set implicitly or explicitly.
3935 if not Is_Static_Subtype (Ityp) then
3939 -- Otherwise accumulate next dimension
3941 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
3942 Expr_Value (Type_Low_Bound (Ityp)) +
3946 exit when No (Indx);
3952 Error_Msg_Uint_1 := Asiz;
3954 ("size for& too small, minimum allowed is ^", N, T);
3955 Set_Esize (T, Asiz);
3956 Set_RM_Size (T, Asiz);
3960 -- All other composite types are ignored
3962 elsif Is_Composite_Type (UT) then
3965 -- For fixed-point types, don't check minimum if type is not frozen,
3966 -- since we don't know all the characteristics of the type that can
3967 -- affect the size (e.g. a specified small) till freeze time.
3969 elsif Is_Fixed_Point_Type (UT)
3970 and then not Is_Frozen (UT)
3974 -- Cases for which a minimum check is required
3977 -- Ignore if specified size is correct for the type
3979 if Known_Esize (UT) and then Siz = Esize (UT) then
3983 -- Otherwise get minimum size
3985 M := UI_From_Int (Minimum_Size (UT));
3989 -- Size is less than minimum size, but one possibility remains
3990 -- that we can manage with the new size if we bias the type.
3992 M := UI_From_Int (Minimum_Size (UT, Biased => True));
3995 Error_Msg_Uint_1 := M;
3997 ("size for& too small, minimum allowed is ^", N, T);
4007 -------------------------
4008 -- Get_Alignment_Value --
4009 -------------------------
4011 function Get_Alignment_Value (Expr : Node_Id) return Uint is
4012 Align : constant Uint := Static_Integer (Expr);
4015 if Align = No_Uint then
4018 elsif Align <= 0 then
4019 Error_Msg_N ("alignment value must be positive", Expr);
4023 for J in Int range 0 .. 64 loop
4025 M : constant Uint := Uint_2 ** J;
4028 exit when M = Align;
4032 ("alignment value must be power of 2", Expr);
4040 end Get_Alignment_Value;
4046 procedure Initialize is
4048 Unchecked_Conversions.Init;
4051 -------------------------
4052 -- Is_Operational_Item --
4053 -------------------------
4055 function Is_Operational_Item (N : Node_Id) return Boolean is
4057 if Nkind (N) /= N_Attribute_Definition_Clause then
4061 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
4063 return Id = Attribute_Input
4064 or else Id = Attribute_Output
4065 or else Id = Attribute_Read
4066 or else Id = Attribute_Write
4067 or else Id = Attribute_External_Tag;
4070 end Is_Operational_Item;
4076 function Minimum_Size
4078 Biased : Boolean := False) return Nat
4080 Lo : Uint := No_Uint;
4081 Hi : Uint := No_Uint;
4082 LoR : Ureal := No_Ureal;
4083 HiR : Ureal := No_Ureal;
4084 LoSet : Boolean := False;
4085 HiSet : Boolean := False;
4089 R_Typ : constant Entity_Id := Root_Type (T);
4092 -- If bad type, return 0
4094 if T = Any_Type then
4097 -- For generic types, just return zero. There cannot be any legitimate
4098 -- need to know such a size, but this routine may be called with a
4099 -- generic type as part of normal processing.
4101 elsif Is_Generic_Type (R_Typ)
4102 or else R_Typ = Any_Type
4106 -- Access types. Normally an access type cannot have a size smaller
4107 -- than the size of System.Address. The exception is on VMS, where
4108 -- we have short and long addresses, and it is possible for an access
4109 -- type to have a short address size (and thus be less than the size
4110 -- of System.Address itself). We simply skip the check for VMS, and
4111 -- leave it to the back end to do the check.
4113 elsif Is_Access_Type (T) then
4114 if OpenVMS_On_Target then
4117 return System_Address_Size;
4120 -- Floating-point types
4122 elsif Is_Floating_Point_Type (T) then
4123 return UI_To_Int (Esize (R_Typ));
4127 elsif Is_Discrete_Type (T) then
4129 -- The following loop is looking for the nearest compile time known
4130 -- bounds following the ancestor subtype chain. The idea is to find
4131 -- the most restrictive known bounds information.
4135 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4140 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
4141 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
4148 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
4149 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
4155 Ancest := Ancestor_Subtype (Ancest);
4158 Ancest := Base_Type (T);
4160 if Is_Generic_Type (Ancest) then
4166 -- Fixed-point types. We can't simply use Expr_Value to get the
4167 -- Corresponding_Integer_Value values of the bounds, since these do not
4168 -- get set till the type is frozen, and this routine can be called
4169 -- before the type is frozen. Similarly the test for bounds being static
4170 -- needs to include the case where we have unanalyzed real literals for
4173 elsif Is_Fixed_Point_Type (T) then
4175 -- The following loop is looking for the nearest compile time known
4176 -- bounds following the ancestor subtype chain. The idea is to find
4177 -- the most restrictive known bounds information.
4181 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4185 -- Note: In the following two tests for LoSet and HiSet, it may
4186 -- seem redundant to test for N_Real_Literal here since normally
4187 -- one would assume that the test for the value being known at
4188 -- compile time includes this case. However, there is a glitch.
4189 -- If the real literal comes from folding a non-static expression,
4190 -- then we don't consider any non- static expression to be known
4191 -- at compile time if we are in configurable run time mode (needed
4192 -- in some cases to give a clearer definition of what is and what
4193 -- is not accepted). So the test is indeed needed. Without it, we
4194 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
4197 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
4198 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
4200 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
4207 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
4208 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
4210 HiR := Expr_Value_R (Type_High_Bound (Ancest));
4216 Ancest := Ancestor_Subtype (Ancest);
4219 Ancest := Base_Type (T);
4221 if Is_Generic_Type (Ancest) then
4227 Lo := UR_To_Uint (LoR / Small_Value (T));
4228 Hi := UR_To_Uint (HiR / Small_Value (T));
4230 -- No other types allowed
4233 raise Program_Error;
4236 -- Fall through with Hi and Lo set. Deal with biased case
4239 and then not Is_Fixed_Point_Type (T)
4240 and then not (Is_Enumeration_Type (T)
4241 and then Has_Non_Standard_Rep (T)))
4242 or else Has_Biased_Representation (T)
4248 -- Signed case. Note that we consider types like range 1 .. -1 to be
4249 -- signed for the purpose of computing the size, since the bounds have
4250 -- to be accommodated in the base type.
4252 if Lo < 0 or else Hi < 0 then
4256 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
4257 -- Note that we accommodate the case where the bounds cross. This
4258 -- can happen either because of the way the bounds are declared
4259 -- or because of the algorithm in Freeze_Fixed_Point_Type.
4273 -- If both bounds are positive, make sure that both are represen-
4274 -- table in the case where the bounds are crossed. This can happen
4275 -- either because of the way the bounds are declared, or because of
4276 -- the algorithm in Freeze_Fixed_Point_Type.
4282 -- S = size, (can accommodate 0 .. (2**size - 1))
4285 while Hi >= Uint_2 ** S loop
4293 ---------------------------
4294 -- New_Stream_Subprogram --
4295 ---------------------------
4297 procedure New_Stream_Subprogram
4301 Nam : TSS_Name_Type)
4303 Loc : constant Source_Ptr := Sloc (N);
4304 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
4305 Subp_Id : Entity_Id;
4306 Subp_Decl : Node_Id;
4310 Defer_Declaration : constant Boolean :=
4311 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
4312 -- For a tagged type, there is a declaration for each stream attribute
4313 -- at the freeze point, and we must generate only a completion of this
4314 -- declaration. We do the same for private types, because the full view
4315 -- might be tagged. Otherwise we generate a declaration at the point of
4316 -- the attribute definition clause.
4318 function Build_Spec return Node_Id;
4319 -- Used for declaration and renaming declaration, so that this is
4320 -- treated as a renaming_as_body.
4326 function Build_Spec return Node_Id is
4327 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
4330 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
4333 Subp_Id := Make_Defining_Identifier (Loc, Sname);
4335 -- S : access Root_Stream_Type'Class
4337 Formals := New_List (
4338 Make_Parameter_Specification (Loc,
4339 Defining_Identifier =>
4340 Make_Defining_Identifier (Loc, Name_S),
4342 Make_Access_Definition (Loc,
4345 Designated_Type (Etype (F)), Loc))));
4347 if Nam = TSS_Stream_Input then
4348 Spec := Make_Function_Specification (Loc,
4349 Defining_Unit_Name => Subp_Id,
4350 Parameter_Specifications => Formals,
4351 Result_Definition => T_Ref);
4356 Make_Parameter_Specification (Loc,
4357 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
4358 Out_Present => Out_P,
4359 Parameter_Type => T_Ref));
4362 Make_Procedure_Specification (Loc,
4363 Defining_Unit_Name => Subp_Id,
4364 Parameter_Specifications => Formals);
4370 -- Start of processing for New_Stream_Subprogram
4373 F := First_Formal (Subp);
4375 if Ekind (Subp) = E_Procedure then
4376 Etyp := Etype (Next_Formal (F));
4378 Etyp := Etype (Subp);
4381 -- Prepare subprogram declaration and insert it as an action on the
4382 -- clause node. The visibility for this entity is used to test for
4383 -- visibility of the attribute definition clause (in the sense of
4384 -- 8.3(23) as amended by AI-195).
4386 if not Defer_Declaration then
4388 Make_Subprogram_Declaration (Loc,
4389 Specification => Build_Spec);
4391 -- For a tagged type, there is always a visible declaration for each
4392 -- stream TSS (it is a predefined primitive operation), and the
4393 -- completion of this declaration occurs at the freeze point, which is
4394 -- not always visible at places where the attribute definition clause is
4395 -- visible. So, we create a dummy entity here for the purpose of
4396 -- tracking the visibility of the attribute definition clause itself.
4400 Make_Defining_Identifier (Loc,
4401 Chars => New_External_Name (Sname, 'V'));
4403 Make_Object_Declaration (Loc,
4404 Defining_Identifier => Subp_Id,
4405 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
4408 Insert_Action (N, Subp_Decl);
4409 Set_Entity (N, Subp_Id);
4412 Make_Subprogram_Renaming_Declaration (Loc,
4413 Specification => Build_Spec,
4414 Name => New_Reference_To (Subp, Loc));
4416 if Defer_Declaration then
4417 Set_TSS (Base_Type (Ent), Subp_Id);
4419 Insert_Action (N, Subp_Decl);
4420 Copy_TSS (Subp_Id, Base_Type (Ent));
4422 end New_Stream_Subprogram;
4424 ------------------------
4425 -- Rep_Item_Too_Early --
4426 ------------------------
4428 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
4430 -- Cannot apply non-operational rep items to generic types
4432 if Is_Operational_Item (N) then
4436 and then Is_Generic_Type (Root_Type (T))
4438 Error_Msg_N ("representation item not allowed for generic type", N);
4442 -- Otherwise check for incomplete type
4444 if Is_Incomplete_Or_Private_Type (T)
4445 and then No (Underlying_Type (T))
4448 ("representation item must be after full type declaration", N);
4451 -- If the type has incomplete components, a representation clause is
4452 -- illegal but stream attributes and Convention pragmas are correct.
4454 elsif Has_Private_Component (T) then
4455 if Nkind (N) = N_Pragma then
4459 ("representation item must appear after type is fully defined",
4466 end Rep_Item_Too_Early;
4468 -----------------------
4469 -- Rep_Item_Too_Late --
4470 -----------------------
4472 function Rep_Item_Too_Late
4475 FOnly : Boolean := False) return Boolean
4478 Parent_Type : Entity_Id;
4481 -- Output the too late message. Note that this is not considered a
4482 -- serious error, since the effect is simply that we ignore the
4483 -- representation clause in this case.
4489 procedure Too_Late is
4491 Error_Msg_N ("|representation item appears too late!", N);
4494 -- Start of processing for Rep_Item_Too_Late
4497 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
4498 -- types, which may be frozen if they appear in a representation clause
4499 -- for a local type.
4502 and then not From_With_Type (T)
4505 S := First_Subtype (T);
4507 if Present (Freeze_Node (S)) then
4509 ("?no more representation items for }", Freeze_Node (S), S);
4514 -- Check for case of non-tagged derived type whose parent either has
4515 -- primitive operations, or is a by reference type (RM 13.1(10)).
4519 and then Is_Derived_Type (T)
4520 and then not Is_Tagged_Type (T)
4522 Parent_Type := Etype (Base_Type (T));
4524 if Has_Primitive_Operations (Parent_Type) then
4527 ("primitive operations already defined for&!", N, Parent_Type);
4530 elsif Is_By_Reference_Type (Parent_Type) then
4533 ("parent type & is a by reference type!", N, Parent_Type);
4538 -- No error, link item into head of chain of rep items for the entity,
4539 -- but avoid chaining if we have an overloadable entity, and the pragma
4540 -- is one that can apply to multiple overloaded entities.
4542 if Is_Overloadable (T)
4543 and then Nkind (N) = N_Pragma
4546 Pname : constant Name_Id := Pragma_Name (N);
4548 if Pname = Name_Convention or else
4549 Pname = Name_Import or else
4550 Pname = Name_Export or else
4551 Pname = Name_External or else
4552 Pname = Name_Interface
4559 Record_Rep_Item (T, N);
4561 end Rep_Item_Too_Late;
4563 -------------------------
4564 -- Same_Representation --
4565 -------------------------
4567 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
4568 T1 : constant Entity_Id := Underlying_Type (Typ1);
4569 T2 : constant Entity_Id := Underlying_Type (Typ2);
4572 -- A quick check, if base types are the same, then we definitely have
4573 -- the same representation, because the subtype specific representation
4574 -- attributes (Size and Alignment) do not affect representation from
4575 -- the point of view of this test.
4577 if Base_Type (T1) = Base_Type (T2) then
4580 elsif Is_Private_Type (Base_Type (T2))
4581 and then Base_Type (T1) = Full_View (Base_Type (T2))
4586 -- Tagged types never have differing representations
4588 if Is_Tagged_Type (T1) then
4592 -- Representations are definitely different if conventions differ
4594 if Convention (T1) /= Convention (T2) then
4598 -- Representations are different if component alignments differ
4600 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4602 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4603 and then Component_Alignment (T1) /= Component_Alignment (T2)
4608 -- For arrays, the only real issue is component size. If we know the
4609 -- component size for both arrays, and it is the same, then that's
4610 -- good enough to know we don't have a change of representation.
4612 if Is_Array_Type (T1) then
4613 if Known_Component_Size (T1)
4614 and then Known_Component_Size (T2)
4615 and then Component_Size (T1) = Component_Size (T2)
4621 -- Types definitely have same representation if neither has non-standard
4622 -- representation since default representations are always consistent.
4623 -- If only one has non-standard representation, and the other does not,
4624 -- then we consider that they do not have the same representation. They
4625 -- might, but there is no way of telling early enough.
4627 if Has_Non_Standard_Rep (T1) then
4628 if not Has_Non_Standard_Rep (T2) then
4632 return not Has_Non_Standard_Rep (T2);
4635 -- Here the two types both have non-standard representation, and we need
4636 -- to determine if they have the same non-standard representation.
4638 -- For arrays, we simply need to test if the component sizes are the
4639 -- same. Pragma Pack is reflected in modified component sizes, so this
4640 -- check also deals with pragma Pack.
4642 if Is_Array_Type (T1) then
4643 return Component_Size (T1) = Component_Size (T2);
4645 -- Tagged types always have the same representation, because it is not
4646 -- possible to specify different representations for common fields.
4648 elsif Is_Tagged_Type (T1) then
4651 -- Case of record types
4653 elsif Is_Record_Type (T1) then
4655 -- Packed status must conform
4657 if Is_Packed (T1) /= Is_Packed (T2) then
4660 -- Otherwise we must check components. Typ2 maybe a constrained
4661 -- subtype with fewer components, so we compare the components
4662 -- of the base types.
4665 Record_Case : declare
4666 CD1, CD2 : Entity_Id;
4668 function Same_Rep return Boolean;
4669 -- CD1 and CD2 are either components or discriminants. This
4670 -- function tests whether the two have the same representation
4676 function Same_Rep return Boolean is
4678 if No (Component_Clause (CD1)) then
4679 return No (Component_Clause (CD2));
4683 Present (Component_Clause (CD2))
4685 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4687 Esize (CD1) = Esize (CD2);
4691 -- Start of processing for Record_Case
4694 if Has_Discriminants (T1) then
4695 CD1 := First_Discriminant (T1);
4696 CD2 := First_Discriminant (T2);
4698 -- The number of discriminants may be different if the
4699 -- derived type has fewer (constrained by values). The
4700 -- invisible discriminants retain the representation of
4701 -- the original, so the discrepancy does not per se
4702 -- indicate a different representation.
4705 and then Present (CD2)
4707 if not Same_Rep then
4710 Next_Discriminant (CD1);
4711 Next_Discriminant (CD2);
4716 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4717 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4719 while Present (CD1) loop
4720 if not Same_Rep then
4723 Next_Component (CD1);
4724 Next_Component (CD2);
4732 -- For enumeration types, we must check each literal to see if the
4733 -- representation is the same. Note that we do not permit enumeration
4734 -- representation clauses for Character and Wide_Character, so these
4735 -- cases were already dealt with.
4737 elsif Is_Enumeration_Type (T1) then
4739 Enumeration_Case : declare
4743 L1 := First_Literal (T1);
4744 L2 := First_Literal (T2);
4746 while Present (L1) loop
4747 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4757 end Enumeration_Case;
4759 -- Any other types have the same representation for these purposes
4764 end Same_Representation;
4766 --------------------
4767 -- Set_Enum_Esize --
4768 --------------------
4770 procedure Set_Enum_Esize (T : Entity_Id) is
4778 -- Find the minimum standard size (8,16,32,64) that fits
4780 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4781 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4784 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4785 Sz := Standard_Character_Size; -- May be > 8 on some targets
4787 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4790 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4793 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4798 if Hi < Uint_2**08 then
4799 Sz := Standard_Character_Size; -- May be > 8 on some targets
4801 elsif Hi < Uint_2**16 then
4804 elsif Hi < Uint_2**32 then
4807 else pragma Assert (Hi < Uint_2**63);
4812 -- That minimum is the proper size unless we have a foreign convention
4813 -- and the size required is 32 or less, in which case we bump the size
4814 -- up to 32. This is required for C and C++ and seems reasonable for
4815 -- all other foreign conventions.
4817 if Has_Foreign_Convention (T)
4818 and then Esize (T) < Standard_Integer_Size
4820 Init_Esize (T, Standard_Integer_Size);
4826 ------------------------------
4827 -- Validate_Address_Clauses --
4828 ------------------------------
4830 procedure Validate_Address_Clauses is
4832 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4834 ACCR : Address_Clause_Check_Record
4835 renames Address_Clause_Checks.Table (J);
4846 -- Skip processing of this entry if warning already posted
4848 if not Address_Warning_Posted (ACCR.N) then
4850 Expr := Original_Node (Expression (ACCR.N));
4854 X_Alignment := Alignment (ACCR.X);
4855 Y_Alignment := Alignment (ACCR.Y);
4857 -- Similarly obtain sizes
4859 X_Size := Esize (ACCR.X);
4860 Y_Size := Esize (ACCR.Y);
4862 -- Check for large object overlaying smaller one
4865 and then X_Size > Uint_0
4866 and then X_Size > Y_Size
4869 ("?& overlays smaller object", ACCR.N, ACCR.X);
4871 ("\?program execution may be erroneous", ACCR.N);
4872 Error_Msg_Uint_1 := X_Size;
4874 ("\?size of & is ^", ACCR.N, ACCR.X);
4875 Error_Msg_Uint_1 := Y_Size;
4877 ("\?size of & is ^", ACCR.N, ACCR.Y);
4879 -- Check for inadequate alignment, both of the base object
4880 -- and of the offset, if any.
4882 -- Note: we do not check the alignment if we gave a size
4883 -- warning, since it would likely be redundant.
4885 elsif Y_Alignment /= Uint_0
4886 and then (Y_Alignment < X_Alignment
4889 Nkind (Expr) = N_Attribute_Reference
4891 Attribute_Name (Expr) = Name_Address
4893 Has_Compatible_Alignment
4894 (ACCR.X, Prefix (Expr))
4895 /= Known_Compatible))
4898 ("?specified address for& may be inconsistent "
4902 ("\?program execution may be erroneous (RM 13.3(27))",
4904 Error_Msg_Uint_1 := X_Alignment;
4906 ("\?alignment of & is ^",
4908 Error_Msg_Uint_1 := Y_Alignment;
4910 ("\?alignment of & is ^",
4912 if Y_Alignment >= X_Alignment then
4914 ("\?but offset is not multiple of alignment",
4921 end Validate_Address_Clauses;
4923 -----------------------------------
4924 -- Validate_Unchecked_Conversion --
4925 -----------------------------------
4927 procedure Validate_Unchecked_Conversion
4929 Act_Unit : Entity_Id)
4936 -- Obtain source and target types. Note that we call Ancestor_Subtype
4937 -- here because the processing for generic instantiation always makes
4938 -- subtypes, and we want the original frozen actual types.
4940 -- If we are dealing with private types, then do the check on their
4941 -- fully declared counterparts if the full declarations have been
4942 -- encountered (they don't have to be visible, but they must exist!)
4944 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
4946 if Is_Private_Type (Source)
4947 and then Present (Underlying_Type (Source))
4949 Source := Underlying_Type (Source);
4952 Target := Ancestor_Subtype (Etype (Act_Unit));
4954 -- If either type is generic, the instantiation happens within a generic
4955 -- unit, and there is nothing to check. The proper check
4956 -- will happen when the enclosing generic is instantiated.
4958 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
4962 if Is_Private_Type (Target)
4963 and then Present (Underlying_Type (Target))
4965 Target := Underlying_Type (Target);
4968 -- Source may be unconstrained array, but not target
4970 if Is_Array_Type (Target)
4971 and then not Is_Constrained (Target)
4974 ("unchecked conversion to unconstrained array not allowed", N);
4978 -- Warn if conversion between two different convention pointers
4980 if Is_Access_Type (Target)
4981 and then Is_Access_Type (Source)
4982 and then Convention (Target) /= Convention (Source)
4983 and then Warn_On_Unchecked_Conversion
4985 -- Give warnings for subprogram pointers only on most targets. The
4986 -- exception is VMS, where data pointers can have different lengths
4987 -- depending on the pointer convention.
4989 if Is_Access_Subprogram_Type (Target)
4990 or else Is_Access_Subprogram_Type (Source)
4991 or else OpenVMS_On_Target
4994 ("?conversion between pointers with different conventions!", N);
4998 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4999 -- warning when compiling GNAT-related sources.
5001 if Warn_On_Unchecked_Conversion
5002 and then not In_Predefined_Unit (N)
5003 and then RTU_Loaded (Ada_Calendar)
5005 (Chars (Source) = Name_Time
5007 Chars (Target) = Name_Time)
5009 -- If Ada.Calendar is loaded and the name of one of the operands is
5010 -- Time, there is a good chance that this is Ada.Calendar.Time.
5013 Calendar_Time : constant Entity_Id :=
5014 Full_View (RTE (RO_CA_Time));
5016 pragma Assert (Present (Calendar_Time));
5018 if Source = Calendar_Time
5019 or else Target = Calendar_Time
5022 ("?representation of 'Time values may change between " &
5023 "'G'N'A'T versions", N);
5028 -- Make entry in unchecked conversion table for later processing by
5029 -- Validate_Unchecked_Conversions, which will check sizes and alignments
5030 -- (using values set by the back-end where possible). This is only done
5031 -- if the appropriate warning is active.
5033 if Warn_On_Unchecked_Conversion then
5034 Unchecked_Conversions.Append
5035 (New_Val => UC_Entry'
5040 -- If both sizes are known statically now, then back end annotation
5041 -- is not required to do a proper check but if either size is not
5042 -- known statically, then we need the annotation.
5044 if Known_Static_RM_Size (Source)
5045 and then Known_Static_RM_Size (Target)
5049 Back_Annotate_Rep_Info := True;
5053 -- If unchecked conversion to access type, and access type is declared
5054 -- in the same unit as the unchecked conversion, then set the
5055 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
5058 if Is_Access_Type (Target) and then
5059 In_Same_Source_Unit (Target, N)
5061 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
5064 -- Generate N_Validate_Unchecked_Conversion node for back end in
5065 -- case the back end needs to perform special validation checks.
5067 -- Shouldn't this be in Exp_Ch13, since the check only gets done
5068 -- if we have full expansion and the back end is called ???
5071 Make_Validate_Unchecked_Conversion (Sloc (N));
5072 Set_Source_Type (Vnode, Source);
5073 Set_Target_Type (Vnode, Target);
5075 -- If the unchecked conversion node is in a list, just insert before it.
5076 -- If not we have some strange case, not worth bothering about.
5078 if Is_List_Member (N) then
5079 Insert_After (N, Vnode);
5081 end Validate_Unchecked_Conversion;
5083 ------------------------------------
5084 -- Validate_Unchecked_Conversions --
5085 ------------------------------------
5087 procedure Validate_Unchecked_Conversions is
5089 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
5091 T : UC_Entry renames Unchecked_Conversions.Table (N);
5093 Eloc : constant Source_Ptr := T.Eloc;
5094 Source : constant Entity_Id := T.Source;
5095 Target : constant Entity_Id := T.Target;
5101 -- This validation check, which warns if we have unequal sizes for
5102 -- unchecked conversion, and thus potentially implementation
5103 -- dependent semantics, is one of the few occasions on which we
5104 -- use the official RM size instead of Esize. See description in
5105 -- Einfo "Handling of Type'Size Values" for details.
5107 if Serious_Errors_Detected = 0
5108 and then Known_Static_RM_Size (Source)
5109 and then Known_Static_RM_Size (Target)
5111 -- Don't do the check if warnings off for either type, note the
5112 -- deliberate use of OR here instead of OR ELSE to get the flag
5113 -- Warnings_Off_Used set for both types if appropriate.
5115 and then not (Has_Warnings_Off (Source)
5117 Has_Warnings_Off (Target))
5119 Source_Siz := RM_Size (Source);
5120 Target_Siz := RM_Size (Target);
5122 if Source_Siz /= Target_Siz then
5124 ("?types for unchecked conversion have different sizes!",
5127 if All_Errors_Mode then
5128 Error_Msg_Name_1 := Chars (Source);
5129 Error_Msg_Uint_1 := Source_Siz;
5130 Error_Msg_Name_2 := Chars (Target);
5131 Error_Msg_Uint_2 := Target_Siz;
5132 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
5134 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
5136 if Is_Discrete_Type (Source)
5137 and then Is_Discrete_Type (Target)
5139 if Source_Siz > Target_Siz then
5141 ("\?^ high order bits of source will be ignored!",
5144 elsif Is_Unsigned_Type (Source) then
5146 ("\?source will be extended with ^ high order " &
5147 "zero bits?!", Eloc);
5151 ("\?source will be extended with ^ high order " &
5156 elsif Source_Siz < Target_Siz then
5157 if Is_Discrete_Type (Target) then
5158 if Bytes_Big_Endian then
5160 ("\?target value will include ^ undefined " &
5165 ("\?target value will include ^ undefined " &
5172 ("\?^ trailing bits of target value will be " &
5173 "undefined!", Eloc);
5176 else pragma Assert (Source_Siz > Target_Siz);
5178 ("\?^ trailing bits of source will be ignored!",
5185 -- If both types are access types, we need to check the alignment.
5186 -- If the alignment of both is specified, we can do it here.
5188 if Serious_Errors_Detected = 0
5189 and then Ekind (Source) in Access_Kind
5190 and then Ekind (Target) in Access_Kind
5191 and then Target_Strict_Alignment
5192 and then Present (Designated_Type (Source))
5193 and then Present (Designated_Type (Target))
5196 D_Source : constant Entity_Id := Designated_Type (Source);
5197 D_Target : constant Entity_Id := Designated_Type (Target);
5200 if Known_Alignment (D_Source)
5201 and then Known_Alignment (D_Target)
5204 Source_Align : constant Uint := Alignment (D_Source);
5205 Target_Align : constant Uint := Alignment (D_Target);
5208 if Source_Align < Target_Align
5209 and then not Is_Tagged_Type (D_Source)
5211 -- Suppress warning if warnings suppressed on either
5212 -- type or either designated type. Note the use of
5213 -- OR here instead of OR ELSE. That is intentional,
5214 -- we would like to set flag Warnings_Off_Used in
5215 -- all types for which warnings are suppressed.
5217 and then not (Has_Warnings_Off (D_Source)
5219 Has_Warnings_Off (D_Target)
5221 Has_Warnings_Off (Source)
5223 Has_Warnings_Off (Target))
5225 Error_Msg_Uint_1 := Target_Align;
5226 Error_Msg_Uint_2 := Source_Align;
5227 Error_Msg_Node_1 := D_Target;
5228 Error_Msg_Node_2 := D_Source;
5230 ("?alignment of & (^) is stricter than " &
5231 "alignment of & (^)!", Eloc);
5233 ("\?resulting access value may have invalid " &
5234 "alignment!", Eloc);
5242 end Validate_Unchecked_Conversions;
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