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 Errout; use Errout;
30 with Exp_Tss; use Exp_Tss;
31 with Exp_Util; use Exp_Util;
33 with Lib.Xref; use Lib.Xref;
34 with Namet; use Namet;
35 with Nlists; use Nlists;
36 with Nmake; use Nmake;
38 with Restrict; use Restrict;
39 with Rident; use Rident;
40 with Rtsfind; use Rtsfind;
42 with Sem_Aux; use Sem_Aux;
43 with Sem_Ch3; use Sem_Ch3;
44 with Sem_Ch8; use Sem_Ch8;
45 with Sem_Eval; use Sem_Eval;
46 with Sem_Res; use Sem_Res;
47 with Sem_Type; use Sem_Type;
48 with Sem_Util; use Sem_Util;
49 with Sem_Warn; use Sem_Warn;
50 with Snames; use Snames;
51 with Stand; use Stand;
52 with Sinfo; use Sinfo;
54 with Targparm; use Targparm;
55 with Ttypes; use Ttypes;
56 with Tbuild; use Tbuild;
57 with Urealp; use Urealp;
59 with GNAT.Heap_Sort_G;
61 package body Sem_Ch13 is
63 SSU : constant Pos := System_Storage_Unit;
64 -- Convenient short hand for commonly used constant
66 -----------------------
67 -- Local Subprograms --
68 -----------------------
70 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
71 -- This routine is called after setting the Esize of type entity Typ.
72 -- The purpose is to deal with the situation where an alignment has been
73 -- inherited from a derived type that is no longer appropriate for the
74 -- new Esize value. In this case, we reset the Alignment to unknown.
76 function Get_Alignment_Value (Expr : Node_Id) return Uint;
77 -- Given the expression for an alignment value, returns the corresponding
78 -- Uint value. If the value is inappropriate, then error messages are
79 -- posted as required, and a value of No_Uint is returned.
81 function Is_Operational_Item (N : Node_Id) return Boolean;
82 -- A specification for a stream attribute is allowed before the full
83 -- type is declared, as explained in AI-00137 and the corrigendum.
84 -- Attributes that do not specify a representation characteristic are
85 -- operational attributes.
87 procedure New_Stream_Subprogram
92 -- Create a subprogram renaming of a given stream attribute to the
93 -- designated subprogram and then in the tagged case, provide this as a
94 -- primitive operation, or in the non-tagged case make an appropriate TSS
95 -- entry. This is more properly an expansion activity than just semantics,
96 -- but the presence of user-defined stream functions for limited types is a
97 -- legality check, which is why this takes place here rather than in
98 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
99 -- function to be generated.
101 -- To avoid elaboration anomalies with freeze nodes, for untagged types
102 -- we generate both a subprogram declaration and a subprogram renaming
103 -- declaration, so that the attribute specification is handled as a
104 -- renaming_as_body. For tagged types, the specification is one of the
107 ----------------------------------------------
108 -- Table for Validate_Unchecked_Conversions --
109 ----------------------------------------------
111 -- The following table collects unchecked conversions for validation.
112 -- Entries are made by Validate_Unchecked_Conversion and then the
113 -- call to Validate_Unchecked_Conversions does the actual error
114 -- checking and posting of warnings. The reason for this delayed
115 -- processing is to take advantage of back-annotations of size and
116 -- alignment values performed by the back end.
118 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
119 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
120 -- will already have modified all Sloc values if the -gnatD option is set.
122 type UC_Entry is record
123 Eloc : Source_Ptr; -- node used for posting warnings
124 Source : Entity_Id; -- source type for unchecked conversion
125 Target : Entity_Id; -- target type for unchecked conversion
128 package Unchecked_Conversions is new Table.Table (
129 Table_Component_Type => UC_Entry,
130 Table_Index_Type => Int,
131 Table_Low_Bound => 1,
133 Table_Increment => 200,
134 Table_Name => "Unchecked_Conversions");
136 ----------------------------------------
137 -- Table for Validate_Address_Clauses --
138 ----------------------------------------
140 -- If an address clause has the form
142 -- for X'Address use Expr
144 -- where Expr is of the form Y'Address or recursively is a reference
145 -- to a constant of either of these forms, and X and Y are entities of
146 -- objects, then if Y has a smaller alignment than X, that merits a
147 -- warning about possible bad alignment. The following table collects
148 -- address clauses of this kind. We put these in a table so that they
149 -- can be checked after the back end has completed annotation of the
150 -- alignments of objects, since we can catch more cases that way.
152 type Address_Clause_Check_Record is record
154 -- The address clause
157 -- The entity of the object overlaying Y
160 -- The entity of the object being overlaid
163 -- Whether the address is offseted within Y
166 package Address_Clause_Checks is new Table.Table (
167 Table_Component_Type => Address_Clause_Check_Record,
168 Table_Index_Type => Int,
169 Table_Low_Bound => 1,
171 Table_Increment => 200,
172 Table_Name => "Address_Clause_Checks");
174 -----------------------------------------
175 -- Adjust_Record_For_Reverse_Bit_Order --
176 -----------------------------------------
178 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
183 -- Processing depends on version of Ada
187 -- For Ada 95, we just renumber bits within a storage unit. We do
188 -- the same for Ada 83 mode, since we recognize pragma Bit_Order
189 -- in Ada 83, and are free to add this extension.
191 when Ada_83 | Ada_95 =>
192 Comp := First_Component_Or_Discriminant (R);
193 while Present (Comp) loop
194 CC := Component_Clause (Comp);
196 -- If component clause is present, then deal with the non-
197 -- default bit order case for Ada 95 mode.
199 -- We only do this processing for the base type, and in
200 -- fact that's important, since otherwise if there are
201 -- record subtypes, we could reverse the bits once for
202 -- each subtype, which would be incorrect.
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
278 -- value to account for the reverse bit order.
279 -- Some examples of what needs to be done are:
281 -- First_Bit .. Last_Bit Component_Bit_Offset
293 -- The general rule is that the first bit is
294 -- is obtained by subtracting the old ending bit
295 -- from storage_unit - 1.
297 Set_Component_Bit_Offset
299 (Storage_Unit_Offset * System_Storage_Unit) +
300 (System_Storage_Unit - 1) -
301 (Start_Bit + CSZ - 1));
303 Set_Normalized_First_Bit
305 Component_Bit_Offset (Comp) mod
306 System_Storage_Unit);
311 Next_Component_Or_Discriminant (Comp);
314 -- For Ada 2005, we do machine scalar processing, as fully described
315 -- In AI-133. This involves gathering all components which start at
316 -- the same byte offset and processing them together
318 when Ada_05 .. Ada_Version_Type'Last =>
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
331 -- whose length is greater than the maximum machine scalar size
332 -- (either accepting them or rejecting as needed). Second, it
333 -- counts the number of components with component clauses whose
334 -- length does 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
414 -- machine scalar size.
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 component list of set of
433 -- components with the same starting position (that
434 -- constitute 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
485 -- position. In this loop we gather groups of clauses
486 -- starting at the same position, to process them in
487 -- accordance with Ada 2005 AI-133.
490 while Stop < Num_CC loop
495 (Last_Bit (Component_Clause (Comps (Start))));
496 while Stop < Num_CC loop
498 (Position (Component_Clause (Comps (Stop + 1)))) =
500 (Position (Component_Clause (Comps (Stop))))
508 (Component_Clause (Comps (Stop)))));
514 -- Now we have a group of component clauses from Start to
515 -- Stop whose positions are identical, and MaxL is the
516 -- maximum last bit value of any of these components.
518 -- We need to determine the corresponding machine scalar
519 -- size. This loop assumes that machine scalar sizes are
520 -- even, and that each possible machine scalar has twice
521 -- as many bits as the next smaller one.
523 MSS := Max_Machine_Scalar_Size;
525 and then (MSS / 2) >= SSU
526 and then (MSS / 2) > MaxL
531 -- Here is where we fix up the Component_Bit_Offset value
532 -- to account for the reverse bit order. Some examples of
533 -- what needs to be done for the case of a machine scalar
536 -- First_Bit .. Last_Bit Component_Bit_Offset
548 -- The general rule is that the first bit is obtained by
549 -- subtracting the old ending bit from machine scalar
552 for C in Start .. Stop loop
554 Comp : constant Entity_Id := Comps (C);
555 CC : constant Node_Id :=
556 Component_Clause (Comp);
557 LB : constant Uint :=
558 Static_Integer (Last_Bit (CC));
559 NFB : constant Uint := MSS - Uint_1 - LB;
560 NLB : constant Uint := NFB + Esize (Comp) - 1;
561 Pos : constant Uint :=
562 Static_Integer (Position (CC));
565 if Warn_On_Reverse_Bit_Order then
566 Error_Msg_Uint_1 := MSS;
568 ("info: reverse bit order in machine " &
569 "scalar of length^?", First_Bit (CC));
570 Error_Msg_Uint_1 := NFB;
571 Error_Msg_Uint_2 := NLB;
573 if Bytes_Big_Endian then
575 ("?\info: big-endian range for "
576 & "component & is ^ .. ^",
577 First_Bit (CC), Comp);
580 ("?\info: little-endian range "
581 & "for component & is ^ .. ^",
582 First_Bit (CC), Comp);
586 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
587 Set_Normalized_First_Bit (Comp, NFB mod SSU);
594 end Adjust_Record_For_Reverse_Bit_Order;
596 --------------------------------------
597 -- Alignment_Check_For_Esize_Change --
598 --------------------------------------
600 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
602 -- If the alignment is known, and not set by a rep clause, and is
603 -- inconsistent with the size being set, then reset it to unknown,
604 -- we assume in this case that the size overrides the inherited
605 -- alignment, and that the alignment must be recomputed.
607 if Known_Alignment (Typ)
608 and then not Has_Alignment_Clause (Typ)
609 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
611 Init_Alignment (Typ);
613 end Alignment_Check_For_Esize_Change;
615 -----------------------
616 -- Analyze_At_Clause --
617 -----------------------
619 -- An at clause is replaced by the corresponding Address attribute
620 -- definition clause that is the preferred approach in Ada 95.
622 procedure Analyze_At_Clause (N : Node_Id) is
623 CS : constant Boolean := Comes_From_Source (N);
626 -- This is an obsolescent feature
628 Check_Restriction (No_Obsolescent_Features, N);
630 if Warn_On_Obsolescent_Feature then
632 ("at clause is an obsolescent feature (RM J.7(2))?", N);
634 ("\use address attribute definition clause instead?", N);
637 -- Rewrite as address clause
640 Make_Attribute_Definition_Clause (Sloc (N),
641 Name => Identifier (N),
642 Chars => Name_Address,
643 Expression => Expression (N)));
645 -- We preserve Comes_From_Source, since logically the clause still
646 -- comes from the source program even though it is changed in form.
648 Set_Comes_From_Source (N, CS);
650 -- Analyze rewritten clause
652 Analyze_Attribute_Definition_Clause (N);
653 end Analyze_At_Clause;
655 -----------------------------------------
656 -- Analyze_Attribute_Definition_Clause --
657 -----------------------------------------
659 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
660 Loc : constant Source_Ptr := Sloc (N);
661 Nam : constant Node_Id := Name (N);
662 Attr : constant Name_Id := Chars (N);
663 Expr : constant Node_Id := Expression (N);
664 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
668 FOnly : Boolean := False;
669 -- Reset to True for subtype specific attribute (Alignment, Size)
670 -- and for stream attributes, i.e. those cases where in the call
671 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
672 -- rules are checked. Note that the case of stream attributes is not
673 -- clear from the RM, but see AI95-00137. Also, the RM seems to
674 -- disallow Storage_Size for derived task types, but that is also
675 -- clearly unintentional.
677 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
678 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
679 -- definition clauses.
681 -----------------------------------
682 -- Analyze_Stream_TSS_Definition --
683 -----------------------------------
685 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
686 Subp : Entity_Id := Empty;
691 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
693 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
694 -- Return true if the entity is a subprogram with an appropriate
695 -- profile for the attribute being defined.
697 ----------------------
698 -- Has_Good_Profile --
699 ----------------------
701 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
703 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
704 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
705 (False => E_Procedure, True => E_Function);
709 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
713 F := First_Formal (Subp);
716 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
717 or else Designated_Type (Etype (F)) /=
718 Class_Wide_Type (RTE (RE_Root_Stream_Type))
723 if not Is_Function then
727 Expected_Mode : constant array (Boolean) of Entity_Kind :=
728 (False => E_In_Parameter,
729 True => E_Out_Parameter);
731 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
742 return Base_Type (Typ) = Base_Type (Ent)
743 and then No (Next_Formal (F));
744 end Has_Good_Profile;
746 -- Start of processing for Analyze_Stream_TSS_Definition
751 if not Is_Type (U_Ent) then
752 Error_Msg_N ("local name must be a subtype", Nam);
756 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
758 -- If Pnam is present, it can be either inherited from an ancestor
759 -- type (in which case it is legal to redefine it for this type), or
760 -- be a previous definition of the attribute for the same type (in
761 -- which case it is illegal).
763 -- In the first case, it will have been analyzed already, and we
764 -- can check that its profile does not match the expected profile
765 -- for a stream attribute of U_Ent. In the second case, either Pnam
766 -- has been analyzed (and has the expected profile), or it has not
767 -- been analyzed yet (case of a type that has not been frozen yet
768 -- and for which the stream attribute has been set using Set_TSS).
771 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
773 Error_Msg_Sloc := Sloc (Pnam);
774 Error_Msg_Name_1 := Attr;
775 Error_Msg_N ("% attribute already defined #", Nam);
781 if Is_Entity_Name (Expr) then
782 if not Is_Overloaded (Expr) then
783 if Has_Good_Profile (Entity (Expr)) then
784 Subp := Entity (Expr);
788 Get_First_Interp (Expr, I, It);
789 while Present (It.Nam) loop
790 if Has_Good_Profile (It.Nam) then
795 Get_Next_Interp (I, It);
800 if Present (Subp) then
801 if Is_Abstract_Subprogram (Subp) then
802 Error_Msg_N ("stream subprogram must not be abstract", Expr);
806 Set_Entity (Expr, Subp);
807 Set_Etype (Expr, Etype (Subp));
809 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
812 Error_Msg_Name_1 := Attr;
813 Error_Msg_N ("incorrect expression for% attribute", Expr);
815 end Analyze_Stream_TSS_Definition;
817 -- Start of processing for Analyze_Attribute_Definition_Clause
820 -- Process Ignore_Rep_Clauses option
822 if Ignore_Rep_Clauses then
825 -- The following should be ignored. They do not affect legality
826 -- and may be target dependent. The basic idea of -gnatI is to
827 -- ignore any rep clauses that may be target dependent but do not
828 -- affect legality (except possibly to be rejected because they
829 -- are incompatible with the compilation target).
831 when Attribute_Alignment |
832 Attribute_Bit_Order |
833 Attribute_Component_Size |
834 Attribute_Machine_Radix |
835 Attribute_Object_Size |
838 Attribute_Stream_Size |
839 Attribute_Value_Size =>
841 Rewrite (N, Make_Null_Statement (Sloc (N)));
844 -- The following should not be ignored, because in the first place
845 -- they are reasonably portable, and should not cause problems in
846 -- compiling code from another target, and also they do affect
847 -- legality, e.g. failing to provide a stream attribute for a
848 -- type may make a program illegal.
850 when Attribute_External_Tag |
854 Attribute_Storage_Pool |
855 Attribute_Storage_Size |
859 -- Other cases are errors ("attribute& cannot be set with
860 -- definition clause"), which will be caught below.
870 if Rep_Item_Too_Early (Ent, N) then
874 -- Rep clause applies to full view of incomplete type or private type if
875 -- we have one (if not, this is a premature use of the type). However,
876 -- certain semantic checks need to be done on the specified entity (i.e.
877 -- the private view), so we save it in Ent.
879 if Is_Private_Type (Ent)
880 and then Is_Derived_Type (Ent)
881 and then not Is_Tagged_Type (Ent)
882 and then No (Full_View (Ent))
884 -- If this is a private type whose completion is a derivation from
885 -- another private type, there is no full view, and the attribute
886 -- belongs to the type itself, not its underlying parent.
890 elsif Ekind (Ent) = E_Incomplete_Type then
892 -- The attribute applies to the full view, set the entity of the
893 -- attribute definition accordingly.
895 Ent := Underlying_Type (Ent);
897 Set_Entity (Nam, Ent);
900 U_Ent := Underlying_Type (Ent);
903 -- Complete other routine error checks
905 if Etype (Nam) = Any_Type then
908 elsif Scope (Ent) /= Current_Scope then
909 Error_Msg_N ("entity must be declared in this scope", Nam);
912 elsif No (U_Ent) then
915 elsif Is_Type (U_Ent)
916 and then not Is_First_Subtype (U_Ent)
917 and then Id /= Attribute_Object_Size
918 and then Id /= Attribute_Value_Size
919 and then not From_At_Mod (N)
921 Error_Msg_N ("cannot specify attribute for subtype", Nam);
925 -- Switch on particular attribute
933 -- Address attribute definition clause
935 when Attribute_Address => Address : begin
937 -- A little error check, catch for X'Address use X'Address;
939 if Nkind (Nam) = N_Identifier
940 and then Nkind (Expr) = N_Attribute_Reference
941 and then Attribute_Name (Expr) = Name_Address
942 and then Nkind (Prefix (Expr)) = N_Identifier
943 and then Chars (Nam) = Chars (Prefix (Expr))
946 ("address for & is self-referencing", Prefix (Expr), Ent);
950 -- Not that special case, carry on with analysis of expression
952 Analyze_And_Resolve (Expr, RTE (RE_Address));
954 -- Even when ignoring rep clauses we need to indicate that the
955 -- entity has an address clause and thus it is legal to declare
958 if Ignore_Rep_Clauses then
959 if Ekind_In (U_Ent, E_Variable, E_Constant) then
960 Record_Rep_Item (U_Ent, N);
966 if Present (Address_Clause (U_Ent)) then
967 Error_Msg_N ("address already given for &", Nam);
969 -- Case of address clause for subprogram
971 elsif Is_Subprogram (U_Ent) then
972 if Has_Homonym (U_Ent) then
974 ("address clause cannot be given " &
975 "for overloaded subprogram",
980 -- For subprograms, all address clauses are permitted, and we
981 -- mark the subprogram as having a deferred freeze so that Gigi
982 -- will not elaborate it too soon.
984 -- Above needs more comments, what is too soon about???
986 Set_Has_Delayed_Freeze (U_Ent);
988 -- Case of address clause for entry
990 elsif Ekind (U_Ent) = E_Entry then
991 if Nkind (Parent (N)) = N_Task_Body then
993 ("entry address must be specified in task spec", Nam);
997 -- For entries, we require a constant address
999 Check_Constant_Address_Clause (Expr, U_Ent);
1001 -- Special checks for task types
1003 if Is_Task_Type (Scope (U_Ent))
1004 and then Comes_From_Source (Scope (U_Ent))
1007 ("?entry address declared for entry in task type", N);
1009 ("\?only one task can be declared of this type", N);
1012 -- Entry address clauses are obsolescent
1014 Check_Restriction (No_Obsolescent_Features, N);
1016 if Warn_On_Obsolescent_Feature then
1018 ("attaching interrupt to task entry is an " &
1019 "obsolescent feature (RM J.7.1)?", N);
1021 ("\use interrupt procedure instead?", N);
1024 -- Case of an address clause for a controlled object which we
1025 -- consider to be erroneous.
1027 elsif Is_Controlled (Etype (U_Ent))
1028 or else Has_Controlled_Component (Etype (U_Ent))
1031 ("?controlled object& must not be overlaid", Nam, U_Ent);
1033 ("\?Program_Error will be raised at run time", Nam);
1034 Insert_Action (Declaration_Node (U_Ent),
1035 Make_Raise_Program_Error (Loc,
1036 Reason => PE_Overlaid_Controlled_Object));
1039 -- Case of address clause for a (non-controlled) object
1042 Ekind (U_Ent) = E_Variable
1044 Ekind (U_Ent) = E_Constant
1047 Expr : constant Node_Id := Expression (N);
1052 -- Exported variables cannot have an address clause, because
1053 -- this cancels the effect of the pragma Export.
1055 if Is_Exported (U_Ent) then
1057 ("cannot export object with address clause", Nam);
1061 Find_Overlaid_Entity (N, O_Ent, Off);
1063 -- Overlaying controlled objects is erroneous
1066 and then (Has_Controlled_Component (Etype (O_Ent))
1067 or else Is_Controlled (Etype (O_Ent)))
1070 ("?cannot overlay with controlled object", Expr);
1072 ("\?Program_Error will be raised at run time", Expr);
1073 Insert_Action (Declaration_Node (U_Ent),
1074 Make_Raise_Program_Error (Loc,
1075 Reason => PE_Overlaid_Controlled_Object));
1078 elsif Present (O_Ent)
1079 and then Ekind (U_Ent) = E_Constant
1080 and then not Is_Constant_Object (O_Ent)
1082 Error_Msg_N ("constant overlays a variable?", Expr);
1084 elsif Present (Renamed_Object (U_Ent)) then
1086 ("address clause not allowed"
1087 & " for a renaming declaration (RM 13.1(6))", Nam);
1090 -- Imported variables can have an address clause, but then
1091 -- the import is pretty meaningless except to suppress
1092 -- initializations, so we do not need such variables to
1093 -- be statically allocated (and in fact it causes trouble
1094 -- if the address clause is a local value).
1096 elsif Is_Imported (U_Ent) then
1097 Set_Is_Statically_Allocated (U_Ent, False);
1100 -- We mark a possible modification of a variable with an
1101 -- address clause, since it is likely aliasing is occurring.
1103 Note_Possible_Modification (Nam, Sure => False);
1105 -- Here we are checking for explicit overlap of one variable
1106 -- by another, and if we find this then mark the overlapped
1107 -- variable as also being volatile to prevent unwanted
1108 -- optimizations. This is a significant pessimization so
1109 -- avoid it when there is an offset, i.e. when the object
1110 -- is composite; they cannot be optimized easily anyway.
1113 and then Is_Object (O_Ent)
1116 Set_Treat_As_Volatile (O_Ent);
1119 -- Legality checks on the address clause for initialized
1120 -- objects is deferred until the freeze point, because
1121 -- a subsequent pragma might indicate that the object is
1122 -- imported and thus not initialized.
1124 Set_Has_Delayed_Freeze (U_Ent);
1126 -- If an initialization call has been generated for this
1127 -- object, it needs to be deferred to after the freeze node
1128 -- we have just now added, otherwise GIGI will see a
1129 -- reference to the variable (as actual to the IP call)
1130 -- before its definition.
1133 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1135 if Present (Init_Call) then
1137 Append_Freeze_Action (U_Ent, Init_Call);
1141 if Is_Exported (U_Ent) then
1143 ("& cannot be exported if an address clause is given",
1146 ("\define and export a variable " &
1147 "that holds its address instead",
1151 -- Entity has delayed freeze, so we will generate an
1152 -- alignment check at the freeze point unless suppressed.
1154 if not Range_Checks_Suppressed (U_Ent)
1155 and then not Alignment_Checks_Suppressed (U_Ent)
1157 Set_Check_Address_Alignment (N);
1160 -- Kill the size check code, since we are not allocating
1161 -- the variable, it is somewhere else.
1163 Kill_Size_Check_Code (U_Ent);
1165 -- If the address clause is of the form:
1167 -- for Y'Address use X'Address
1171 -- Const : constant Address := X'Address;
1173 -- for Y'Address use Const;
1175 -- then we make an entry in the table for checking the size
1176 -- and alignment of the overlaying variable. We defer this
1177 -- check till after code generation to take full advantage
1178 -- of the annotation done by the back end. This entry is
1179 -- only made if the address clause comes from source.
1180 -- If the entity has a generic type, the check will be
1181 -- performed in the instance if the actual type justifies
1182 -- it, and we do not insert the clause in the table to
1183 -- prevent spurious warnings.
1185 if Address_Clause_Overlay_Warnings
1186 and then Comes_From_Source (N)
1187 and then Present (O_Ent)
1188 and then Is_Object (O_Ent)
1190 if not Is_Generic_Type (Etype (U_Ent)) then
1191 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1194 -- If variable overlays a constant view, and we are
1195 -- warning on overlays, then mark the variable as
1196 -- overlaying a constant (we will give warnings later
1197 -- if this variable is assigned).
1199 if Is_Constant_Object (O_Ent)
1200 and then Ekind (U_Ent) = E_Variable
1202 Set_Overlays_Constant (U_Ent);
1207 -- Not a valid entity for an address clause
1210 Error_Msg_N ("address cannot be given for &", Nam);
1218 -- Alignment attribute definition clause
1220 when Attribute_Alignment => Alignment : declare
1221 Align : constant Uint := Get_Alignment_Value (Expr);
1226 if not Is_Type (U_Ent)
1227 and then Ekind (U_Ent) /= E_Variable
1228 and then Ekind (U_Ent) /= E_Constant
1230 Error_Msg_N ("alignment cannot be given for &", Nam);
1232 elsif Has_Alignment_Clause (U_Ent) then
1233 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1234 Error_Msg_N ("alignment clause previously given#", N);
1236 elsif Align /= No_Uint then
1237 Set_Has_Alignment_Clause (U_Ent);
1238 Set_Alignment (U_Ent, Align);
1240 -- For an array type, U_Ent is the first subtype. In that case,
1241 -- also set the alignment of the anonymous base type so that
1242 -- other subtypes (such as the itypes for aggregates of the
1243 -- type) also receive the expected alignment.
1245 if Is_Array_Type (U_Ent) then
1246 Set_Alignment (Base_Type (U_Ent), Align);
1255 -- Bit_Order attribute definition clause
1257 when Attribute_Bit_Order => Bit_Order : declare
1259 if not Is_Record_Type (U_Ent) then
1261 ("Bit_Order can only be defined for record type", Nam);
1264 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1266 if Etype (Expr) = Any_Type then
1269 elsif not Is_Static_Expression (Expr) then
1270 Flag_Non_Static_Expr
1271 ("Bit_Order requires static expression!", Expr);
1274 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1275 Set_Reverse_Bit_Order (U_Ent, True);
1281 --------------------
1282 -- Component_Size --
1283 --------------------
1285 -- Component_Size attribute definition clause
1287 when Attribute_Component_Size => Component_Size_Case : declare
1288 Csize : constant Uint := Static_Integer (Expr);
1291 New_Ctyp : Entity_Id;
1295 if not Is_Array_Type (U_Ent) then
1296 Error_Msg_N ("component size requires array type", Nam);
1300 Btype := Base_Type (U_Ent);
1302 if Has_Component_Size_Clause (Btype) then
1304 ("component size clause for& previously given", Nam);
1306 elsif Csize /= No_Uint then
1307 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
1309 if Has_Aliased_Components (Btype)
1312 and then Csize /= 16
1315 ("component size incorrect for aliased components", N);
1319 -- For the biased case, build a declaration for a subtype
1320 -- that will be used to represent the biased subtype that
1321 -- reflects the biased representation of components. We need
1322 -- this subtype to get proper conversions on referencing
1323 -- elements of the array. Note that component size clauses
1324 -- are ignored in VM mode.
1326 if VM_Target = No_VM then
1329 Make_Defining_Identifier (Loc,
1331 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1334 Make_Subtype_Declaration (Loc,
1335 Defining_Identifier => New_Ctyp,
1336 Subtype_Indication =>
1337 New_Occurrence_Of (Component_Type (Btype), Loc));
1339 Set_Parent (Decl, N);
1340 Analyze (Decl, Suppress => All_Checks);
1342 Set_Has_Delayed_Freeze (New_Ctyp, False);
1343 Set_Esize (New_Ctyp, Csize);
1344 Set_RM_Size (New_Ctyp, Csize);
1345 Init_Alignment (New_Ctyp);
1346 Set_Has_Biased_Representation (New_Ctyp, True);
1347 Set_Is_Itype (New_Ctyp, True);
1348 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1350 Set_Component_Type (Btype, New_Ctyp);
1352 if Warn_On_Biased_Representation then
1354 ("?component size clause forces biased "
1355 & "representation", N);
1359 Set_Component_Size (Btype, Csize);
1361 -- For VM case, we ignore component size clauses
1364 -- Give a warning unless we are in GNAT mode, in which case
1365 -- the warning is suppressed since it is not useful.
1367 if not GNAT_Mode then
1369 ("?component size ignored in this configuration", N);
1373 Set_Has_Component_Size_Clause (Btype, True);
1374 Set_Has_Non_Standard_Rep (Btype, True);
1376 end Component_Size_Case;
1382 when Attribute_External_Tag => External_Tag :
1384 if not Is_Tagged_Type (U_Ent) then
1385 Error_Msg_N ("should be a tagged type", Nam);
1388 Analyze_And_Resolve (Expr, Standard_String);
1390 if not Is_Static_Expression (Expr) then
1391 Flag_Non_Static_Expr
1392 ("static string required for tag name!", Nam);
1395 if VM_Target = No_VM then
1396 Set_Has_External_Tag_Rep_Clause (U_Ent);
1398 Error_Msg_Name_1 := Attr;
1400 ("% attribute unsupported in this configuration", Nam);
1403 if not Is_Library_Level_Entity (U_Ent) then
1405 ("?non-unique external tag supplied for &", N, U_Ent);
1407 ("?\same external tag applies to all subprogram calls", N);
1409 ("?\corresponding internal tag cannot be obtained", N);
1417 when Attribute_Input =>
1418 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1419 Set_Has_Specified_Stream_Input (Ent);
1425 -- Machine radix attribute definition clause
1427 when Attribute_Machine_Radix => Machine_Radix : declare
1428 Radix : constant Uint := Static_Integer (Expr);
1431 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1432 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1434 elsif Has_Machine_Radix_Clause (U_Ent) then
1435 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1436 Error_Msg_N ("machine radix clause previously given#", N);
1438 elsif Radix /= No_Uint then
1439 Set_Has_Machine_Radix_Clause (U_Ent);
1440 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1444 elsif Radix = 10 then
1445 Set_Machine_Radix_10 (U_Ent);
1447 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1456 -- Object_Size attribute definition clause
1458 when Attribute_Object_Size => Object_Size : declare
1459 Size : constant Uint := Static_Integer (Expr);
1462 pragma Warnings (Off, Biased);
1465 if not Is_Type (U_Ent) then
1466 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1468 elsif Has_Object_Size_Clause (U_Ent) then
1469 Error_Msg_N ("Object_Size already given for &", Nam);
1472 Check_Size (Expr, U_Ent, Size, Biased);
1480 UI_Mod (Size, 64) /= 0
1483 ("Object_Size must be 8, 16, 32, or multiple of 64",
1487 Set_Esize (U_Ent, Size);
1488 Set_Has_Object_Size_Clause (U_Ent);
1489 Alignment_Check_For_Esize_Change (U_Ent);
1497 when Attribute_Output =>
1498 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1499 Set_Has_Specified_Stream_Output (Ent);
1505 when Attribute_Read =>
1506 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1507 Set_Has_Specified_Stream_Read (Ent);
1513 -- Size attribute definition clause
1515 when Attribute_Size => Size : declare
1516 Size : constant Uint := Static_Integer (Expr);
1523 if Has_Size_Clause (U_Ent) then
1524 Error_Msg_N ("size already given for &", Nam);
1526 elsif not Is_Type (U_Ent)
1527 and then Ekind (U_Ent) /= E_Variable
1528 and then Ekind (U_Ent) /= E_Constant
1530 Error_Msg_N ("size cannot be given for &", Nam);
1532 elsif Is_Array_Type (U_Ent)
1533 and then not Is_Constrained (U_Ent)
1536 ("size cannot be given for unconstrained array", Nam);
1538 elsif Size /= No_Uint then
1539 if Is_Type (U_Ent) then
1542 Etyp := Etype (U_Ent);
1545 -- Check size, note that Gigi is in charge of checking that the
1546 -- size of an array or record type is OK. Also we do not check
1547 -- the size in the ordinary fixed-point case, since it is too
1548 -- early to do so (there may be subsequent small clause that
1549 -- affects the size). We can check the size if a small clause
1550 -- has already been given.
1552 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1553 or else Has_Small_Clause (U_Ent)
1555 Check_Size (Expr, Etyp, Size, Biased);
1556 Set_Has_Biased_Representation (U_Ent, Biased);
1558 if Biased and Warn_On_Biased_Representation then
1560 ("?size clause forces biased representation", N);
1564 -- For types set RM_Size and Esize if possible
1566 if Is_Type (U_Ent) then
1567 Set_RM_Size (U_Ent, Size);
1569 -- For scalar types, increase Object_Size to power of 2, but
1570 -- not less than a storage unit in any case (i.e., normally
1571 -- this means it will be byte addressable).
1573 if Is_Scalar_Type (U_Ent) then
1574 if Size <= System_Storage_Unit then
1575 Init_Esize (U_Ent, System_Storage_Unit);
1576 elsif Size <= 16 then
1577 Init_Esize (U_Ent, 16);
1578 elsif Size <= 32 then
1579 Init_Esize (U_Ent, 32);
1581 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1584 -- For all other types, object size = value size. The
1585 -- backend will adjust as needed.
1588 Set_Esize (U_Ent, Size);
1591 Alignment_Check_For_Esize_Change (U_Ent);
1593 -- For objects, set Esize only
1596 if Is_Elementary_Type (Etyp) then
1597 if Size /= System_Storage_Unit
1599 Size /= System_Storage_Unit * 2
1601 Size /= System_Storage_Unit * 4
1603 Size /= System_Storage_Unit * 8
1605 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1606 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1608 ("size for primitive object must be a power of 2"
1609 & " in the range ^-^", N);
1613 Set_Esize (U_Ent, Size);
1616 Set_Has_Size_Clause (U_Ent);
1624 -- Small attribute definition clause
1626 when Attribute_Small => Small : declare
1627 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1631 Analyze_And_Resolve (Expr, Any_Real);
1633 if Etype (Expr) = Any_Type then
1636 elsif not Is_Static_Expression (Expr) then
1637 Flag_Non_Static_Expr
1638 ("small requires static expression!", Expr);
1642 Small := Expr_Value_R (Expr);
1644 if Small <= Ureal_0 then
1645 Error_Msg_N ("small value must be greater than zero", Expr);
1651 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1653 ("small requires an ordinary fixed point type", Nam);
1655 elsif Has_Small_Clause (U_Ent) then
1656 Error_Msg_N ("small already given for &", Nam);
1658 elsif Small > Delta_Value (U_Ent) then
1660 ("small value must not be greater then delta value", Nam);
1663 Set_Small_Value (U_Ent, Small);
1664 Set_Small_Value (Implicit_Base, Small);
1665 Set_Has_Small_Clause (U_Ent);
1666 Set_Has_Small_Clause (Implicit_Base);
1667 Set_Has_Non_Standard_Rep (Implicit_Base);
1675 -- Storage_Pool attribute definition clause
1677 when Attribute_Storage_Pool => Storage_Pool : declare
1682 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1684 ("storage pool cannot be given for access-to-subprogram type",
1689 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
1692 ("storage pool can only be given for access types", Nam);
1695 elsif Is_Derived_Type (U_Ent) then
1697 ("storage pool cannot be given for a derived access type",
1700 elsif Has_Storage_Size_Clause (U_Ent) then
1701 Error_Msg_N ("storage size already given for &", Nam);
1704 elsif Present (Associated_Storage_Pool (U_Ent)) then
1705 Error_Msg_N ("storage pool already given for &", Nam);
1710 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1712 if not Denotes_Variable (Expr) then
1713 Error_Msg_N ("storage pool must be a variable", Expr);
1717 if Nkind (Expr) = N_Type_Conversion then
1718 T := Etype (Expression (Expr));
1723 -- The Stack_Bounded_Pool is used internally for implementing
1724 -- access types with a Storage_Size. Since it only work
1725 -- properly when used on one specific type, we need to check
1726 -- that it is not hijacked improperly:
1727 -- type T is access Integer;
1728 -- for T'Storage_Size use n;
1729 -- type Q is access Float;
1730 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1732 if RTE_Available (RE_Stack_Bounded_Pool)
1733 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1735 Error_Msg_N ("non-shareable internal Pool", Expr);
1739 -- If the argument is a name that is not an entity name, then
1740 -- we construct a renaming operation to define an entity of
1741 -- type storage pool.
1743 if not Is_Entity_Name (Expr)
1744 and then Is_Object_Reference (Expr)
1746 Pool := Make_Temporary (Loc, 'P', Expr);
1749 Rnode : constant Node_Id :=
1750 Make_Object_Renaming_Declaration (Loc,
1751 Defining_Identifier => Pool,
1753 New_Occurrence_Of (Etype (Expr), Loc),
1757 Insert_Before (N, Rnode);
1759 Set_Associated_Storage_Pool (U_Ent, Pool);
1762 elsif Is_Entity_Name (Expr) then
1763 Pool := Entity (Expr);
1765 -- If pool is a renamed object, get original one. This can
1766 -- happen with an explicit renaming, and within instances.
1768 while Present (Renamed_Object (Pool))
1769 and then Is_Entity_Name (Renamed_Object (Pool))
1771 Pool := Entity (Renamed_Object (Pool));
1774 if Present (Renamed_Object (Pool))
1775 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1776 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1778 Pool := Entity (Expression (Renamed_Object (Pool)));
1781 Set_Associated_Storage_Pool (U_Ent, Pool);
1783 elsif Nkind (Expr) = N_Type_Conversion
1784 and then Is_Entity_Name (Expression (Expr))
1785 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1787 Pool := Entity (Expression (Expr));
1788 Set_Associated_Storage_Pool (U_Ent, Pool);
1791 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1800 -- Storage_Size attribute definition clause
1802 when Attribute_Storage_Size => Storage_Size : declare
1803 Btype : constant Entity_Id := Base_Type (U_Ent);
1807 if Is_Task_Type (U_Ent) then
1808 Check_Restriction (No_Obsolescent_Features, N);
1810 if Warn_On_Obsolescent_Feature then
1812 ("storage size clause for task is an " &
1813 "obsolescent feature (RM J.9)?", N);
1814 Error_Msg_N ("\use Storage_Size pragma instead?", N);
1820 if not Is_Access_Type (U_Ent)
1821 and then Ekind (U_Ent) /= E_Task_Type
1823 Error_Msg_N ("storage size cannot be given for &", Nam);
1825 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1827 ("storage size cannot be given for a derived access type",
1830 elsif Has_Storage_Size_Clause (Btype) then
1831 Error_Msg_N ("storage size already given for &", Nam);
1834 Analyze_And_Resolve (Expr, Any_Integer);
1836 if Is_Access_Type (U_Ent) then
1837 if Present (Associated_Storage_Pool (U_Ent)) then
1838 Error_Msg_N ("storage pool already given for &", Nam);
1842 if Compile_Time_Known_Value (Expr)
1843 and then Expr_Value (Expr) = 0
1845 Set_No_Pool_Assigned (Btype);
1848 else -- Is_Task_Type (U_Ent)
1849 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1851 if Present (Sprag) then
1852 Error_Msg_Sloc := Sloc (Sprag);
1854 ("Storage_Size already specified#", Nam);
1859 Set_Has_Storage_Size_Clause (Btype);
1867 when Attribute_Stream_Size => Stream_Size : declare
1868 Size : constant Uint := Static_Integer (Expr);
1871 if Ada_Version <= Ada_95 then
1872 Check_Restriction (No_Implementation_Attributes, N);
1875 if Has_Stream_Size_Clause (U_Ent) then
1876 Error_Msg_N ("Stream_Size already given for &", Nam);
1878 elsif Is_Elementary_Type (U_Ent) then
1879 if Size /= System_Storage_Unit
1881 Size /= System_Storage_Unit * 2
1883 Size /= System_Storage_Unit * 4
1885 Size /= System_Storage_Unit * 8
1887 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1889 ("stream size for elementary type must be a"
1890 & " power of 2 and at least ^", N);
1892 elsif RM_Size (U_Ent) > Size then
1893 Error_Msg_Uint_1 := RM_Size (U_Ent);
1895 ("stream size for elementary type must be a"
1896 & " power of 2 and at least ^", N);
1899 Set_Has_Stream_Size_Clause (U_Ent);
1902 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1910 -- Value_Size attribute definition clause
1912 when Attribute_Value_Size => Value_Size : declare
1913 Size : constant Uint := Static_Integer (Expr);
1917 if not Is_Type (U_Ent) then
1918 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1921 (Get_Attribute_Definition_Clause
1922 (U_Ent, Attribute_Value_Size))
1924 Error_Msg_N ("Value_Size already given for &", Nam);
1926 elsif Is_Array_Type (U_Ent)
1927 and then not Is_Constrained (U_Ent)
1930 ("Value_Size cannot be given for unconstrained array", Nam);
1933 if Is_Elementary_Type (U_Ent) then
1934 Check_Size (Expr, U_Ent, Size, Biased);
1935 Set_Has_Biased_Representation (U_Ent, Biased);
1937 if Biased and Warn_On_Biased_Representation then
1939 ("?value size clause forces biased representation", N);
1943 Set_RM_Size (U_Ent, Size);
1951 when Attribute_Write =>
1952 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1953 Set_Has_Specified_Stream_Write (Ent);
1955 -- All other attributes cannot be set
1959 ("attribute& cannot be set with definition clause", N);
1962 -- The test for the type being frozen must be performed after
1963 -- any expression the clause has been analyzed since the expression
1964 -- itself might cause freezing that makes the clause illegal.
1966 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1969 end Analyze_Attribute_Definition_Clause;
1971 ----------------------------
1972 -- Analyze_Code_Statement --
1973 ----------------------------
1975 procedure Analyze_Code_Statement (N : Node_Id) is
1976 HSS : constant Node_Id := Parent (N);
1977 SBody : constant Node_Id := Parent (HSS);
1978 Subp : constant Entity_Id := Current_Scope;
1985 -- Analyze and check we get right type, note that this implements the
1986 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1987 -- is the only way that Asm_Insn could possibly be visible.
1989 Analyze_And_Resolve (Expression (N));
1991 if Etype (Expression (N)) = Any_Type then
1993 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1994 Error_Msg_N ("incorrect type for code statement", N);
1998 Check_Code_Statement (N);
2000 -- Make sure we appear in the handled statement sequence of a
2001 -- subprogram (RM 13.8(3)).
2003 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2004 or else Nkind (SBody) /= N_Subprogram_Body
2007 ("code statement can only appear in body of subprogram", N);
2011 -- Do remaining checks (RM 13.8(3)) if not already done
2013 if not Is_Machine_Code_Subprogram (Subp) then
2014 Set_Is_Machine_Code_Subprogram (Subp);
2016 -- No exception handlers allowed
2018 if Present (Exception_Handlers (HSS)) then
2020 ("exception handlers not permitted in machine code subprogram",
2021 First (Exception_Handlers (HSS)));
2024 -- No declarations other than use clauses and pragmas (we allow
2025 -- certain internally generated declarations as well).
2027 Decl := First (Declarations (SBody));
2028 while Present (Decl) loop
2029 DeclO := Original_Node (Decl);
2030 if Comes_From_Source (DeclO)
2031 and not Nkind_In (DeclO, N_Pragma,
2032 N_Use_Package_Clause,
2034 N_Implicit_Label_Declaration)
2037 ("this declaration not allowed in machine code subprogram",
2044 -- No statements other than code statements, pragmas, and labels.
2045 -- Again we allow certain internally generated statements.
2047 Stmt := First (Statements (HSS));
2048 while Present (Stmt) loop
2049 StmtO := Original_Node (Stmt);
2050 if Comes_From_Source (StmtO)
2051 and then not Nkind_In (StmtO, N_Pragma,
2056 ("this statement is not allowed in machine code subprogram",
2063 end Analyze_Code_Statement;
2065 -----------------------------------------------
2066 -- Analyze_Enumeration_Representation_Clause --
2067 -----------------------------------------------
2069 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2070 Ident : constant Node_Id := Identifier (N);
2071 Aggr : constant Node_Id := Array_Aggregate (N);
2072 Enumtype : Entity_Id;
2078 Err : Boolean := False;
2080 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2081 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2086 if Ignore_Rep_Clauses then
2090 -- First some basic error checks
2093 Enumtype := Entity (Ident);
2095 if Enumtype = Any_Type
2096 or else Rep_Item_Too_Early (Enumtype, N)
2100 Enumtype := Underlying_Type (Enumtype);
2103 if not Is_Enumeration_Type (Enumtype) then
2105 ("enumeration type required, found}",
2106 Ident, First_Subtype (Enumtype));
2110 -- Ignore rep clause on generic actual type. This will already have
2111 -- been flagged on the template as an error, and this is the safest
2112 -- way to ensure we don't get a junk cascaded message in the instance.
2114 if Is_Generic_Actual_Type (Enumtype) then
2117 -- Type must be in current scope
2119 elsif Scope (Enumtype) /= Current_Scope then
2120 Error_Msg_N ("type must be declared in this scope", Ident);
2123 -- Type must be a first subtype
2125 elsif not Is_First_Subtype (Enumtype) then
2126 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2129 -- Ignore duplicate rep clause
2131 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2132 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2135 -- Don't allow rep clause for standard [wide_[wide_]]character
2137 elsif Is_Standard_Character_Type (Enumtype) then
2138 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2141 -- Check that the expression is a proper aggregate (no parentheses)
2143 elsif Paren_Count (Aggr) /= 0 then
2145 ("extra parentheses surrounding aggregate not allowed",
2149 -- All tests passed, so set rep clause in place
2152 Set_Has_Enumeration_Rep_Clause (Enumtype);
2153 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2156 -- Now we process the aggregate. Note that we don't use the normal
2157 -- aggregate code for this purpose, because we don't want any of the
2158 -- normal expansion activities, and a number of special semantic
2159 -- rules apply (including the component type being any integer type)
2161 Elit := First_Literal (Enumtype);
2163 -- First the positional entries if any
2165 if Present (Expressions (Aggr)) then
2166 Expr := First (Expressions (Aggr));
2167 while Present (Expr) loop
2169 Error_Msg_N ("too many entries in aggregate", Expr);
2173 Val := Static_Integer (Expr);
2175 -- Err signals that we found some incorrect entries processing
2176 -- the list. The final checks for completeness and ordering are
2177 -- skipped in this case.
2179 if Val = No_Uint then
2181 elsif Val < Lo or else Hi < Val then
2182 Error_Msg_N ("value outside permitted range", Expr);
2186 Set_Enumeration_Rep (Elit, Val);
2187 Set_Enumeration_Rep_Expr (Elit, Expr);
2193 -- Now process the named entries if present
2195 if Present (Component_Associations (Aggr)) then
2196 Assoc := First (Component_Associations (Aggr));
2197 while Present (Assoc) loop
2198 Choice := First (Choices (Assoc));
2200 if Present (Next (Choice)) then
2202 ("multiple choice not allowed here", Next (Choice));
2206 if Nkind (Choice) = N_Others_Choice then
2207 Error_Msg_N ("others choice not allowed here", Choice);
2210 elsif Nkind (Choice) = N_Range then
2211 -- ??? should allow zero/one element range here
2212 Error_Msg_N ("range not allowed here", Choice);
2216 Analyze_And_Resolve (Choice, Enumtype);
2218 if Is_Entity_Name (Choice)
2219 and then Is_Type (Entity (Choice))
2221 Error_Msg_N ("subtype name not allowed here", Choice);
2223 -- ??? should allow static subtype with zero/one entry
2225 elsif Etype (Choice) = Base_Type (Enumtype) then
2226 if not Is_Static_Expression (Choice) then
2227 Flag_Non_Static_Expr
2228 ("non-static expression used for choice!", Choice);
2232 Elit := Expr_Value_E (Choice);
2234 if Present (Enumeration_Rep_Expr (Elit)) then
2235 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2237 ("representation for& previously given#",
2242 Set_Enumeration_Rep_Expr (Elit, Choice);
2244 Expr := Expression (Assoc);
2245 Val := Static_Integer (Expr);
2247 if Val = No_Uint then
2250 elsif Val < Lo or else Hi < Val then
2251 Error_Msg_N ("value outside permitted range", Expr);
2255 Set_Enumeration_Rep (Elit, Val);
2264 -- Aggregate is fully processed. Now we check that a full set of
2265 -- representations was given, and that they are in range and in order.
2266 -- These checks are only done if no other errors occurred.
2272 Elit := First_Literal (Enumtype);
2273 while Present (Elit) loop
2274 if No (Enumeration_Rep_Expr (Elit)) then
2275 Error_Msg_NE ("missing representation for&!", N, Elit);
2278 Val := Enumeration_Rep (Elit);
2280 if Min = No_Uint then
2284 if Val /= No_Uint then
2285 if Max /= No_Uint and then Val <= Max then
2287 ("enumeration value for& not ordered!",
2288 Enumeration_Rep_Expr (Elit), Elit);
2294 -- If there is at least one literal whose representation
2295 -- is not equal to the Pos value, then note that this
2296 -- enumeration type has a non-standard representation.
2298 if Val /= Enumeration_Pos (Elit) then
2299 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2306 -- Now set proper size information
2309 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2312 if Has_Size_Clause (Enumtype) then
2313 if Esize (Enumtype) >= Minsize then
2318 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2320 if Esize (Enumtype) < Minsize then
2321 Error_Msg_N ("previously given size is too small", N);
2324 Set_Has_Biased_Representation (Enumtype);
2329 Set_RM_Size (Enumtype, Minsize);
2330 Set_Enum_Esize (Enumtype);
2333 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2334 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2335 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2339 -- We repeat the too late test in case it froze itself!
2341 if Rep_Item_Too_Late (Enumtype, N) then
2344 end Analyze_Enumeration_Representation_Clause;
2346 ----------------------------
2347 -- Analyze_Free_Statement --
2348 ----------------------------
2350 procedure Analyze_Free_Statement (N : Node_Id) is
2352 Analyze (Expression (N));
2353 end Analyze_Free_Statement;
2355 ---------------------------
2356 -- Analyze_Freeze_Entity --
2357 ---------------------------
2359 procedure Analyze_Freeze_Entity (N : Node_Id) is
2360 E : constant Entity_Id := Entity (N);
2363 -- For tagged types covering interfaces add internal entities that link
2364 -- the primitives of the interfaces with the primitives that cover them.
2366 -- Note: These entities were originally generated only when generating
2367 -- code because their main purpose was to provide support to initialize
2368 -- the secondary dispatch tables. They are now generated also when
2369 -- compiling with no code generation to provide ASIS the relationship
2370 -- between interface primitives and tagged type primitives. They are
2371 -- also used to locate primitives covering interfaces when processing
2372 -- generics (see Derive_Subprograms).
2374 if Ada_Version >= Ada_05
2375 and then Ekind (E) = E_Record_Type
2376 and then Is_Tagged_Type (E)
2377 and then not Is_Interface (E)
2378 and then Has_Interfaces (E)
2380 -- This would be a good common place to call the routine that checks
2381 -- overriding of interface primitives (and thus factorize calls to
2382 -- Check_Abstract_Overriding located at different contexts in the
2383 -- compiler). However, this is not possible because it causes
2384 -- spurious errors in case of late overriding.
2386 Add_Internal_Interface_Entities (E);
2388 end Analyze_Freeze_Entity;
2390 ------------------------------------------
2391 -- Analyze_Record_Representation_Clause --
2392 ------------------------------------------
2394 -- Note: we check as much as we can here, but we can't do any checks
2395 -- based on the position values (e.g. overlap checks) until freeze time
2396 -- because especially in Ada 2005 (machine scalar mode), the processing
2397 -- for non-standard bit order can substantially change the positions.
2398 -- See procedure Check_Record_Representation_Clause (called from Freeze)
2399 -- for the remainder of this processing.
2401 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2402 Ident : constant Node_Id := Identifier (N);
2403 Rectype : Entity_Id;
2408 Hbit : Uint := Uint_0;
2413 CR_Pragma : Node_Id := Empty;
2414 -- Points to N_Pragma node if Complete_Representation pragma present
2417 if Ignore_Rep_Clauses then
2422 Rectype := Entity (Ident);
2424 if Rectype = Any_Type
2425 or else Rep_Item_Too_Early (Rectype, N)
2429 Rectype := Underlying_Type (Rectype);
2432 -- First some basic error checks
2434 if not Is_Record_Type (Rectype) then
2436 ("record type required, found}", Ident, First_Subtype (Rectype));
2439 elsif Is_Unchecked_Union (Rectype) then
2441 ("record rep clause not allowed for Unchecked_Union", N);
2443 elsif Scope (Rectype) /= Current_Scope then
2444 Error_Msg_N ("type must be declared in this scope", N);
2447 elsif not Is_First_Subtype (Rectype) then
2448 Error_Msg_N ("cannot give record rep clause for subtype", N);
2451 elsif Has_Record_Rep_Clause (Rectype) then
2452 Error_Msg_N ("duplicate record rep clause ignored", N);
2455 elsif Rep_Item_Too_Late (Rectype, N) then
2459 if Present (Mod_Clause (N)) then
2461 Loc : constant Source_Ptr := Sloc (N);
2462 M : constant Node_Id := Mod_Clause (N);
2463 P : constant List_Id := Pragmas_Before (M);
2467 pragma Warnings (Off, Mod_Val);
2470 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2472 if Warn_On_Obsolescent_Feature then
2474 ("mod clause is an obsolescent feature (RM J.8)?", N);
2476 ("\use alignment attribute definition clause instead?", N);
2483 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2484 -- the Mod clause into an alignment clause anyway, so that the
2485 -- back-end can compute and back-annotate properly the size and
2486 -- alignment of types that may include this record.
2488 -- This seems dubious, this destroys the source tree in a manner
2489 -- not detectable by ASIS ???
2491 if Operating_Mode = Check_Semantics
2495 Make_Attribute_Definition_Clause (Loc,
2496 Name => New_Reference_To (Base_Type (Rectype), Loc),
2497 Chars => Name_Alignment,
2498 Expression => Relocate_Node (Expression (M)));
2500 Set_From_At_Mod (AtM_Nod);
2501 Insert_After (N, AtM_Nod);
2502 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2503 Set_Mod_Clause (N, Empty);
2506 -- Get the alignment value to perform error checking
2508 Mod_Val := Get_Alignment_Value (Expression (M));
2513 -- For untagged types, clear any existing component clauses for the
2514 -- type. If the type is derived, this is what allows us to override
2515 -- a rep clause for the parent. For type extensions, the representation
2516 -- of the inherited components is inherited, so we want to keep previous
2517 -- component clauses for completeness.
2519 if not Is_Tagged_Type (Rectype) then
2520 Comp := First_Component_Or_Discriminant (Rectype);
2521 while Present (Comp) loop
2522 Set_Component_Clause (Comp, Empty);
2523 Next_Component_Or_Discriminant (Comp);
2527 -- All done if no component clauses
2529 CC := First (Component_Clauses (N));
2535 -- A representation like this applies to the base type
2537 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2538 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2539 Set_Has_Specified_Layout (Base_Type (Rectype));
2541 -- Process the component clauses
2543 while Present (CC) loop
2547 if Nkind (CC) = N_Pragma then
2550 -- The only pragma of interest is Complete_Representation
2552 if Pragma_Name (CC) = Name_Complete_Representation then
2556 -- Processing for real component clause
2559 Posit := Static_Integer (Position (CC));
2560 Fbit := Static_Integer (First_Bit (CC));
2561 Lbit := Static_Integer (Last_Bit (CC));
2564 and then Fbit /= No_Uint
2565 and then Lbit /= No_Uint
2569 ("position cannot be negative", Position (CC));
2573 ("first bit cannot be negative", First_Bit (CC));
2575 -- The Last_Bit specified in a component clause must not be
2576 -- less than the First_Bit minus one (RM-13.5.1(10)).
2578 elsif Lbit < Fbit - 1 then
2580 ("last bit cannot be less than first bit minus one",
2583 -- Values look OK, so find the corresponding record component
2584 -- Even though the syntax allows an attribute reference for
2585 -- implementation-defined components, GNAT does not allow the
2586 -- tag to get an explicit position.
2588 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2589 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2590 Error_Msg_N ("position of tag cannot be specified", CC);
2592 Error_Msg_N ("illegal component name", CC);
2596 Comp := First_Entity (Rectype);
2597 while Present (Comp) loop
2598 exit when Chars (Comp) = Chars (Component_Name (CC));
2604 -- Maybe component of base type that is absent from
2605 -- statically constrained first subtype.
2607 Comp := First_Entity (Base_Type (Rectype));
2608 while Present (Comp) loop
2609 exit when Chars (Comp) = Chars (Component_Name (CC));
2616 ("component clause is for non-existent field", CC);
2618 elsif Present (Component_Clause (Comp)) then
2620 -- Diagnose duplicate rep clause, or check consistency
2621 -- if this is an inherited component. In a double fault,
2622 -- there may be a duplicate inconsistent clause for an
2623 -- inherited component.
2625 if Scope (Original_Record_Component (Comp)) = Rectype
2626 or else Parent (Component_Clause (Comp)) = N
2628 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2629 Error_Msg_N ("component clause previously given#", CC);
2633 Rep1 : constant Node_Id := Component_Clause (Comp);
2635 if Intval (Position (Rep1)) /=
2636 Intval (Position (CC))
2637 or else Intval (First_Bit (Rep1)) /=
2638 Intval (First_Bit (CC))
2639 or else Intval (Last_Bit (Rep1)) /=
2640 Intval (Last_Bit (CC))
2642 Error_Msg_N ("component clause inconsistent "
2643 & "with representation of ancestor", CC);
2644 elsif Warn_On_Redundant_Constructs then
2645 Error_Msg_N ("?redundant component clause "
2646 & "for inherited component!", CC);
2651 -- Normal case where this is the first component clause we
2652 -- have seen for this entity, so set it up properly.
2655 -- Make reference for field in record rep clause and set
2656 -- appropriate entity field in the field identifier.
2659 (Comp, Component_Name (CC), Set_Ref => False);
2660 Set_Entity (Component_Name (CC), Comp);
2662 -- Update Fbit and Lbit to the actual bit number
2664 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2665 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2667 if Has_Size_Clause (Rectype)
2668 and then Esize (Rectype) <= Lbit
2671 ("bit number out of range of specified size",
2674 Set_Component_Clause (Comp, CC);
2675 Set_Component_Bit_Offset (Comp, Fbit);
2676 Set_Esize (Comp, 1 + (Lbit - Fbit));
2677 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2678 Set_Normalized_Position (Comp, Fbit / SSU);
2680 -- This information is also set in the corresponding
2681 -- component of the base type, found by accessing the
2682 -- Original_Record_Component link if it is present.
2684 Ocomp := Original_Record_Component (Comp);
2691 (Component_Name (CC),
2696 Set_Has_Biased_Representation (Comp, Biased);
2698 if Biased and Warn_On_Biased_Representation then
2700 ("?component clause forces biased "
2701 & "representation", CC);
2704 if Present (Ocomp) then
2705 Set_Component_Clause (Ocomp, CC);
2706 Set_Component_Bit_Offset (Ocomp, Fbit);
2707 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2708 Set_Normalized_Position (Ocomp, Fbit / SSU);
2709 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2711 Set_Normalized_Position_Max
2712 (Ocomp, Normalized_Position (Ocomp));
2714 Set_Has_Biased_Representation
2715 (Ocomp, Has_Biased_Representation (Comp));
2718 if Esize (Comp) < 0 then
2719 Error_Msg_N ("component size is negative", CC);
2730 -- Check missing components if Complete_Representation pragma appeared
2732 if Present (CR_Pragma) then
2733 Comp := First_Component_Or_Discriminant (Rectype);
2734 while Present (Comp) loop
2735 if No (Component_Clause (Comp)) then
2737 ("missing component clause for &", CR_Pragma, Comp);
2740 Next_Component_Or_Discriminant (Comp);
2743 -- If no Complete_Representation pragma, warn if missing components
2745 elsif Warn_On_Unrepped_Components then
2747 Num_Repped_Components : Nat := 0;
2748 Num_Unrepped_Components : Nat := 0;
2751 -- First count number of repped and unrepped components
2753 Comp := First_Component_Or_Discriminant (Rectype);
2754 while Present (Comp) loop
2755 if Present (Component_Clause (Comp)) then
2756 Num_Repped_Components := Num_Repped_Components + 1;
2758 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2761 Next_Component_Or_Discriminant (Comp);
2764 -- We are only interested in the case where there is at least one
2765 -- unrepped component, and at least half the components have rep
2766 -- clauses. We figure that if less than half have them, then the
2767 -- partial rep clause is really intentional. If the component
2768 -- type has no underlying type set at this point (as for a generic
2769 -- formal type), we don't know enough to give a warning on the
2772 if Num_Unrepped_Components > 0
2773 and then Num_Unrepped_Components < Num_Repped_Components
2775 Comp := First_Component_Or_Discriminant (Rectype);
2776 while Present (Comp) loop
2777 if No (Component_Clause (Comp))
2778 and then Comes_From_Source (Comp)
2779 and then Present (Underlying_Type (Etype (Comp)))
2780 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2781 or else Size_Known_At_Compile_Time
2782 (Underlying_Type (Etype (Comp))))
2783 and then not Has_Warnings_Off (Rectype)
2785 Error_Msg_Sloc := Sloc (Comp);
2787 ("?no component clause given for & declared #",
2791 Next_Component_Or_Discriminant (Comp);
2796 end Analyze_Record_Representation_Clause;
2798 -----------------------------------
2799 -- Check_Constant_Address_Clause --
2800 -----------------------------------
2802 procedure Check_Constant_Address_Clause
2806 procedure Check_At_Constant_Address (Nod : Node_Id);
2807 -- Checks that the given node N represents a name whose 'Address is
2808 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2809 -- address value is the same at the point of declaration of U_Ent and at
2810 -- the time of elaboration of the address clause.
2812 procedure Check_Expr_Constants (Nod : Node_Id);
2813 -- Checks that Nod meets the requirements for a constant address clause
2814 -- in the sense of the enclosing procedure.
2816 procedure Check_List_Constants (Lst : List_Id);
2817 -- Check that all elements of list Lst meet the requirements for a
2818 -- constant address clause in the sense of the enclosing procedure.
2820 -------------------------------
2821 -- Check_At_Constant_Address --
2822 -------------------------------
2824 procedure Check_At_Constant_Address (Nod : Node_Id) is
2826 if Is_Entity_Name (Nod) then
2827 if Present (Address_Clause (Entity ((Nod)))) then
2829 ("invalid address clause for initialized object &!",
2832 ("address for& cannot" &
2833 " depend on another address clause! (RM 13.1(22))!",
2836 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2837 and then Sloc (U_Ent) < Sloc (Entity (Nod))
2840 ("invalid address clause for initialized object &!",
2842 Error_Msg_Node_2 := U_Ent;
2844 ("\& must be defined before & (RM 13.1(22))!",
2848 elsif Nkind (Nod) = N_Selected_Component then
2850 T : constant Entity_Id := Etype (Prefix (Nod));
2853 if (Is_Record_Type (T)
2854 and then Has_Discriminants (T))
2857 and then Is_Record_Type (Designated_Type (T))
2858 and then Has_Discriminants (Designated_Type (T)))
2861 ("invalid address clause for initialized object &!",
2864 ("\address cannot depend on component" &
2865 " of discriminated record (RM 13.1(22))!",
2868 Check_At_Constant_Address (Prefix (Nod));
2872 elsif Nkind (Nod) = N_Indexed_Component then
2873 Check_At_Constant_Address (Prefix (Nod));
2874 Check_List_Constants (Expressions (Nod));
2877 Check_Expr_Constants (Nod);
2879 end Check_At_Constant_Address;
2881 --------------------------
2882 -- Check_Expr_Constants --
2883 --------------------------
2885 procedure Check_Expr_Constants (Nod : Node_Id) is
2886 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
2887 Ent : Entity_Id := Empty;
2890 if Nkind (Nod) in N_Has_Etype
2891 and then Etype (Nod) = Any_Type
2897 when N_Empty | N_Error =>
2900 when N_Identifier | N_Expanded_Name =>
2901 Ent := Entity (Nod);
2903 -- We need to look at the original node if it is different
2904 -- from the node, since we may have rewritten things and
2905 -- substituted an identifier representing the rewrite.
2907 if Original_Node (Nod) /= Nod then
2908 Check_Expr_Constants (Original_Node (Nod));
2910 -- If the node is an object declaration without initial
2911 -- value, some code has been expanded, and the expression
2912 -- is not constant, even if the constituents might be
2913 -- acceptable, as in A'Address + offset.
2915 if Ekind (Ent) = E_Variable
2917 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
2919 No (Expression (Declaration_Node (Ent)))
2922 ("invalid address clause for initialized object &!",
2925 -- If entity is constant, it may be the result of expanding
2926 -- a check. We must verify that its declaration appears
2927 -- before the object in question, else we also reject the
2930 elsif Ekind (Ent) = E_Constant
2931 and then In_Same_Source_Unit (Ent, U_Ent)
2932 and then Sloc (Ent) > Loc_U_Ent
2935 ("invalid address clause for initialized object &!",
2942 -- Otherwise look at the identifier and see if it is OK
2944 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
2945 or else Is_Type (Ent)
2950 Ekind (Ent) = E_Constant
2952 Ekind (Ent) = E_In_Parameter
2954 -- This is the case where we must have Ent defined before
2955 -- U_Ent. Clearly if they are in different units this
2956 -- requirement is met since the unit containing Ent is
2957 -- already processed.
2959 if not In_Same_Source_Unit (Ent, U_Ent) then
2962 -- Otherwise location of Ent must be before the location
2963 -- of U_Ent, that's what prior defined means.
2965 elsif Sloc (Ent) < Loc_U_Ent then
2970 ("invalid address clause for initialized object &!",
2972 Error_Msg_Node_2 := U_Ent;
2974 ("\& must be defined before & (RM 13.1(22))!",
2978 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
2979 Check_Expr_Constants (Original_Node (Nod));
2983 ("invalid address clause for initialized object &!",
2986 if Comes_From_Source (Ent) then
2988 ("\reference to variable& not allowed"
2989 & " (RM 13.1(22))!", Nod, Ent);
2992 ("non-static expression not allowed"
2993 & " (RM 13.1(22))!", Nod);
2997 when N_Integer_Literal =>
2999 -- If this is a rewritten unchecked conversion, in a system
3000 -- where Address is an integer type, always use the base type
3001 -- for a literal value. This is user-friendly and prevents
3002 -- order-of-elaboration issues with instances of unchecked
3005 if Nkind (Original_Node (Nod)) = N_Function_Call then
3006 Set_Etype (Nod, Base_Type (Etype (Nod)));
3009 when N_Real_Literal |
3011 N_Character_Literal =>
3015 Check_Expr_Constants (Low_Bound (Nod));
3016 Check_Expr_Constants (High_Bound (Nod));
3018 when N_Explicit_Dereference =>
3019 Check_Expr_Constants (Prefix (Nod));
3021 when N_Indexed_Component =>
3022 Check_Expr_Constants (Prefix (Nod));
3023 Check_List_Constants (Expressions (Nod));
3026 Check_Expr_Constants (Prefix (Nod));
3027 Check_Expr_Constants (Discrete_Range (Nod));
3029 when N_Selected_Component =>
3030 Check_Expr_Constants (Prefix (Nod));
3032 when N_Attribute_Reference =>
3033 if Attribute_Name (Nod) = Name_Address
3035 Attribute_Name (Nod) = Name_Access
3037 Attribute_Name (Nod) = Name_Unchecked_Access
3039 Attribute_Name (Nod) = Name_Unrestricted_Access
3041 Check_At_Constant_Address (Prefix (Nod));
3044 Check_Expr_Constants (Prefix (Nod));
3045 Check_List_Constants (Expressions (Nod));
3049 Check_List_Constants (Component_Associations (Nod));
3050 Check_List_Constants (Expressions (Nod));
3052 when N_Component_Association =>
3053 Check_Expr_Constants (Expression (Nod));
3055 when N_Extension_Aggregate =>
3056 Check_Expr_Constants (Ancestor_Part (Nod));
3057 Check_List_Constants (Component_Associations (Nod));
3058 Check_List_Constants (Expressions (Nod));
3063 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3064 Check_Expr_Constants (Left_Opnd (Nod));
3065 Check_Expr_Constants (Right_Opnd (Nod));
3068 Check_Expr_Constants (Right_Opnd (Nod));
3070 when N_Type_Conversion |
3071 N_Qualified_Expression |
3073 Check_Expr_Constants (Expression (Nod));
3075 when N_Unchecked_Type_Conversion =>
3076 Check_Expr_Constants (Expression (Nod));
3078 -- If this is a rewritten unchecked conversion, subtypes in
3079 -- this node are those created within the instance. To avoid
3080 -- order of elaboration issues, replace them with their base
3081 -- types. Note that address clauses can cause order of
3082 -- elaboration problems because they are elaborated by the
3083 -- back-end at the point of definition, and may mention
3084 -- entities declared in between (as long as everything is
3085 -- static). It is user-friendly to allow unchecked conversions
3088 if Nkind (Original_Node (Nod)) = N_Function_Call then
3089 Set_Etype (Expression (Nod),
3090 Base_Type (Etype (Expression (Nod))));
3091 Set_Etype (Nod, Base_Type (Etype (Nod)));
3094 when N_Function_Call =>
3095 if not Is_Pure (Entity (Name (Nod))) then
3097 ("invalid address clause for initialized object &!",
3101 ("\function & is not pure (RM 13.1(22))!",
3102 Nod, Entity (Name (Nod)));
3105 Check_List_Constants (Parameter_Associations (Nod));
3108 when N_Parameter_Association =>
3109 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3113 ("invalid address clause for initialized object &!",
3116 ("\must be constant defined before& (RM 13.1(22))!",
3119 end Check_Expr_Constants;
3121 --------------------------
3122 -- Check_List_Constants --
3123 --------------------------
3125 procedure Check_List_Constants (Lst : List_Id) is
3129 if Present (Lst) then
3130 Nod1 := First (Lst);
3131 while Present (Nod1) loop
3132 Check_Expr_Constants (Nod1);
3136 end Check_List_Constants;
3138 -- Start of processing for Check_Constant_Address_Clause
3141 Check_Expr_Constants (Expr);
3142 end Check_Constant_Address_Clause;
3144 ----------------------------------------
3145 -- Check_Record_Representation_Clause --
3146 ----------------------------------------
3148 procedure Check_Record_Representation_Clause (N : Node_Id) is
3149 Loc : constant Source_Ptr := Sloc (N);
3150 Ident : constant Node_Id := Identifier (N);
3151 Rectype : Entity_Id;
3156 Hbit : Uint := Uint_0;
3160 Max_Bit_So_Far : Uint;
3161 -- Records the maximum bit position so far. If all field positions
3162 -- are monotonically increasing, then we can skip the circuit for
3163 -- checking for overlap, since no overlap is possible.
3165 Tagged_Parent : Entity_Id := Empty;
3166 -- This is set in the case of a derived tagged type for which we have
3167 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
3168 -- positioned by record representation clauses). In this case we must
3169 -- check for overlap between components of this tagged type, and the
3170 -- components of its parent. Tagged_Parent will point to this parent
3171 -- type. For all other cases Tagged_Parent is left set to Empty.
3173 Parent_Last_Bit : Uint;
3174 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
3175 -- last bit position for any field in the parent type. We only need to
3176 -- check overlap for fields starting below this point.
3178 Overlap_Check_Required : Boolean;
3179 -- Used to keep track of whether or not an overlap check is required
3181 Ccount : Natural := 0;
3182 -- Number of component clauses in record rep clause
3184 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
3185 -- Given two entities for record components or discriminants, checks
3186 -- if they have overlapping component clauses and issues errors if so.
3188 procedure Find_Component;
3189 -- Finds component entity corresponding to current component clause (in
3190 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
3191 -- start/stop bits for the field. If there is no matching component or
3192 -- if the matching component does not have a component clause, then
3193 -- that's an error and Comp is set to Empty, but no error message is
3194 -- issued, since the message was already given. Comp is also set to
3195 -- Empty if the current "component clause" is in fact a pragma.
3197 -----------------------------
3198 -- Check_Component_Overlap --
3199 -----------------------------
3201 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
3202 CC1 : constant Node_Id := Component_Clause (C1_Ent);
3203 CC2 : constant Node_Id := Component_Clause (C2_Ent);
3205 if Present (CC1) and then Present (CC2) then
3207 -- Exclude odd case where we have two tag fields in the same
3208 -- record, both at location zero. This seems a bit strange, but
3209 -- it seems to happen in some circumstances, perhaps on an error.
3211 if Chars (C1_Ent) = Name_uTag
3213 Chars (C2_Ent) = Name_uTag
3218 -- Here we check if the two fields overlap
3221 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
3222 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
3223 E1 : constant Uint := S1 + Esize (C1_Ent);
3224 E2 : constant Uint := S2 + Esize (C2_Ent);
3227 if E2 <= S1 or else E1 <= S2 then
3230 Error_Msg_Node_2 := Component_Name (CC2);
3231 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
3232 Error_Msg_Node_1 := Component_Name (CC1);
3234 ("component& overlaps & #", Component_Name (CC1));
3238 end Check_Component_Overlap;
3240 --------------------
3241 -- Find_Component --
3242 --------------------
3244 procedure Find_Component is
3246 procedure Search_Component (R : Entity_Id);
3247 -- Search components of R for a match. If found, Comp is set.
3249 ----------------------
3250 -- Search_Component --
3251 ----------------------
3253 procedure Search_Component (R : Entity_Id) is
3255 Comp := First_Component_Or_Discriminant (R);
3256 while Present (Comp) loop
3258 -- Ignore error of attribute name for component name (we
3259 -- already gave an error message for this, so no need to
3262 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
3265 exit when Chars (Comp) = Chars (Component_Name (CC));
3268 Next_Component_Or_Discriminant (Comp);
3270 end Search_Component;
3272 -- Start of processing for Find_Component
3275 -- Return with Comp set to Empty if we have a pragma
3277 if Nkind (CC) = N_Pragma then
3282 -- Search current record for matching component
3284 Search_Component (Rectype);
3286 -- If not found, maybe component of base type that is absent from
3287 -- statically constrained first subtype.
3290 Search_Component (Base_Type (Rectype));
3293 -- If no component, or the component does not reference the component
3294 -- clause in question, then there was some previous error for which
3295 -- we already gave a message, so just return with Comp Empty.
3298 or else Component_Clause (Comp) /= CC
3302 -- Normal case where we have a component clause
3305 Fbit := Component_Bit_Offset (Comp);
3306 Lbit := Fbit + Esize (Comp) - 1;
3310 -- Start of processing for Check_Record_Representation_Clause
3314 Rectype := Entity (Ident);
3316 if Rectype = Any_Type then
3319 Rectype := Underlying_Type (Rectype);
3322 -- See if we have a fully repped derived tagged type
3325 PS : constant Entity_Id := Parent_Subtype (Rectype);
3328 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
3329 Tagged_Parent := PS;
3331 -- Find maximum bit of any component of the parent type
3333 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
3334 Pcomp := First_Entity (Tagged_Parent);
3335 while Present (Pcomp) loop
3336 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
3337 if Component_Bit_Offset (Pcomp) /= No_Uint
3338 and then Known_Static_Esize (Pcomp)
3343 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
3346 Next_Entity (Pcomp);
3352 -- All done if no component clauses
3354 CC := First (Component_Clauses (N));
3360 -- If a tag is present, then create a component clause that places it
3361 -- at the start of the record (otherwise gigi may place it after other
3362 -- fields that have rep clauses).
3364 Fent := First_Entity (Rectype);
3366 if Nkind (Fent) = N_Defining_Identifier
3367 and then Chars (Fent) = Name_uTag
3369 Set_Component_Bit_Offset (Fent, Uint_0);
3370 Set_Normalized_Position (Fent, Uint_0);
3371 Set_Normalized_First_Bit (Fent, Uint_0);
3372 Set_Normalized_Position_Max (Fent, Uint_0);
3373 Init_Esize (Fent, System_Address_Size);
3375 Set_Component_Clause (Fent,
3376 Make_Component_Clause (Loc,
3378 Make_Identifier (Loc,
3379 Chars => Name_uTag),
3382 Make_Integer_Literal (Loc,
3386 Make_Integer_Literal (Loc,
3390 Make_Integer_Literal (Loc,
3391 UI_From_Int (System_Address_Size))));
3393 Ccount := Ccount + 1;
3396 Max_Bit_So_Far := Uint_Minus_1;
3397 Overlap_Check_Required := False;
3399 -- Process the component clauses
3401 while Present (CC) loop
3404 if Present (Comp) then
3405 Ccount := Ccount + 1;
3407 if Fbit <= Max_Bit_So_Far then
3408 Overlap_Check_Required := True;
3410 Max_Bit_So_Far := Lbit;
3413 -- Check bit position out of range of specified size
3415 if Has_Size_Clause (Rectype)
3416 and then Esize (Rectype) <= Lbit
3419 ("bit number out of range of specified size",
3422 -- Check for overlap with tag field
3425 if Is_Tagged_Type (Rectype)
3426 and then Fbit < System_Address_Size
3429 ("component overlaps tag field of&",
3430 Component_Name (CC), Rectype);
3438 -- Check parent overlap if component might overlap parent field
3440 if Present (Tagged_Parent)
3441 and then Fbit <= Parent_Last_Bit
3443 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
3444 while Present (Pcomp) loop
3445 if not Is_Tag (Pcomp)
3446 and then Chars (Pcomp) /= Name_uParent
3448 Check_Component_Overlap (Comp, Pcomp);
3451 Next_Component_Or_Discriminant (Pcomp);
3459 -- Now that we have processed all the component clauses, check for
3460 -- overlap. We have to leave this till last, since the components can
3461 -- appear in any arbitrary order in the representation clause.
3463 -- We do not need this check if all specified ranges were monotonic,
3464 -- as recorded by Overlap_Check_Required being False at this stage.
3466 -- This first section checks if there are any overlapping entries at
3467 -- all. It does this by sorting all entries and then seeing if there are
3468 -- any overlaps. If there are none, then that is decisive, but if there
3469 -- are overlaps, they may still be OK (they may result from fields in
3470 -- different variants).
3472 if Overlap_Check_Required then
3473 Overlap_Check1 : declare
3475 OC_Fbit : array (0 .. Ccount) of Uint;
3476 -- First-bit values for component clauses, the value is the offset
3477 -- of the first bit of the field from start of record. The zero
3478 -- entry is for use in sorting.
3480 OC_Lbit : array (0 .. Ccount) of Uint;
3481 -- Last-bit values for component clauses, the value is the offset
3482 -- of the last bit of the field from start of record. The zero
3483 -- entry is for use in sorting.
3485 OC_Count : Natural := 0;
3486 -- Count of entries in OC_Fbit and OC_Lbit
3488 function OC_Lt (Op1, Op2 : Natural) return Boolean;
3489 -- Compare routine for Sort
3491 procedure OC_Move (From : Natural; To : Natural);
3492 -- Move routine for Sort
3494 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
3500 function OC_Lt (Op1, Op2 : Natural) return Boolean is
3502 return OC_Fbit (Op1) < OC_Fbit (Op2);
3509 procedure OC_Move (From : Natural; To : Natural) is
3511 OC_Fbit (To) := OC_Fbit (From);
3512 OC_Lbit (To) := OC_Lbit (From);
3515 -- Start of processing for Overlap_Check
3518 CC := First (Component_Clauses (N));
3519 while Present (CC) loop
3521 -- Exclude component clause already marked in error
3523 if not Error_Posted (CC) then
3526 if Present (Comp) then
3527 OC_Count := OC_Count + 1;
3528 OC_Fbit (OC_Count) := Fbit;
3529 OC_Lbit (OC_Count) := Lbit;
3536 Sorting.Sort (OC_Count);
3538 Overlap_Check_Required := False;
3539 for J in 1 .. OC_Count - 1 loop
3540 if OC_Lbit (J) >= OC_Fbit (J + 1) then
3541 Overlap_Check_Required := True;
3548 -- If Overlap_Check_Required is still True, then we have to do the full
3549 -- scale overlap check, since we have at least two fields that do
3550 -- overlap, and we need to know if that is OK since they are in
3551 -- different variant, or whether we have a definite problem.
3553 if Overlap_Check_Required then
3554 Overlap_Check2 : declare
3555 C1_Ent, C2_Ent : Entity_Id;
3556 -- Entities of components being checked for overlap
3559 -- Component_List node whose Component_Items are being checked
3562 -- Component declaration for component being checked
3565 C1_Ent := First_Entity (Base_Type (Rectype));
3567 -- Loop through all components in record. For each component check
3568 -- for overlap with any of the preceding elements on the component
3569 -- list containing the component and also, if the component is in
3570 -- a variant, check against components outside the case structure.
3571 -- This latter test is repeated recursively up the variant tree.
3573 Main_Component_Loop : while Present (C1_Ent) loop
3574 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
3575 goto Continue_Main_Component_Loop;
3578 -- Skip overlap check if entity has no declaration node. This
3579 -- happens with discriminants in constrained derived types.
3580 -- Probably we are missing some checks as a result, but that
3581 -- does not seem terribly serious ???
3583 if No (Declaration_Node (C1_Ent)) then
3584 goto Continue_Main_Component_Loop;
3587 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
3589 -- Loop through component lists that need checking. Check the
3590 -- current component list and all lists in variants above us.
3592 Component_List_Loop : loop
3594 -- If derived type definition, go to full declaration
3595 -- If at outer level, check discriminants if there are any.
3597 if Nkind (Clist) = N_Derived_Type_Definition then
3598 Clist := Parent (Clist);
3601 -- Outer level of record definition, check discriminants
3603 if Nkind_In (Clist, N_Full_Type_Declaration,
3604 N_Private_Type_Declaration)
3606 if Has_Discriminants (Defining_Identifier (Clist)) then
3608 First_Discriminant (Defining_Identifier (Clist));
3609 while Present (C2_Ent) loop
3610 exit when C1_Ent = C2_Ent;
3611 Check_Component_Overlap (C1_Ent, C2_Ent);
3612 Next_Discriminant (C2_Ent);
3616 -- Record extension case
3618 elsif Nkind (Clist) = N_Derived_Type_Definition then
3621 -- Otherwise check one component list
3624 Citem := First (Component_Items (Clist));
3626 while Present (Citem) loop
3627 if Nkind (Citem) = N_Component_Declaration then
3628 C2_Ent := Defining_Identifier (Citem);
3629 exit when C1_Ent = C2_Ent;
3630 Check_Component_Overlap (C1_Ent, C2_Ent);
3637 -- Check for variants above us (the parent of the Clist can
3638 -- be a variant, in which case its parent is a variant part,
3639 -- and the parent of the variant part is a component list
3640 -- whose components must all be checked against the current
3641 -- component for overlap).
3643 if Nkind (Parent (Clist)) = N_Variant then
3644 Clist := Parent (Parent (Parent (Clist)));
3646 -- Check for possible discriminant part in record, this
3647 -- is treated essentially as another level in the
3648 -- recursion. For this case the parent of the component
3649 -- list is the record definition, and its parent is the
3650 -- full type declaration containing the discriminant
3653 elsif Nkind (Parent (Clist)) = N_Record_Definition then
3654 Clist := Parent (Parent ((Clist)));
3656 -- If neither of these two cases, we are at the top of
3660 exit Component_List_Loop;
3662 end loop Component_List_Loop;
3664 <<Continue_Main_Component_Loop>>
3665 Next_Entity (C1_Ent);
3667 end loop Main_Component_Loop;
3671 -- For records that have component clauses for all components, and whose
3672 -- size is less than or equal to 32, we need to know the size in the
3673 -- front end to activate possible packed array processing where the
3674 -- component type is a record.
3676 -- At this stage Hbit + 1 represents the first unused bit from all the
3677 -- component clauses processed, so if the component clauses are
3678 -- complete, then this is the length of the record.
3680 -- For records longer than System.Storage_Unit, and for those where not
3681 -- all components have component clauses, the back end determines the
3682 -- length (it may for example be appropriate to round up the size
3683 -- to some convenient boundary, based on alignment considerations, etc).
3685 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
3687 -- Nothing to do if at least one component has no component clause
3689 Comp := First_Component_Or_Discriminant (Rectype);
3690 while Present (Comp) loop
3691 exit when No (Component_Clause (Comp));
3692 Next_Component_Or_Discriminant (Comp);
3695 -- If we fall out of loop, all components have component clauses
3696 -- and so we can set the size to the maximum value.
3699 Set_RM_Size (Rectype, Hbit + 1);
3702 end Check_Record_Representation_Clause;
3708 procedure Check_Size
3712 Biased : out Boolean)
3714 UT : constant Entity_Id := Underlying_Type (T);
3720 -- Dismiss cases for generic types or types with previous errors
3723 or else UT = Any_Type
3724 or else Is_Generic_Type (UT)
3725 or else Is_Generic_Type (Root_Type (UT))
3729 -- Check case of bit packed array
3731 elsif Is_Array_Type (UT)
3732 and then Known_Static_Component_Size (UT)
3733 and then Is_Bit_Packed_Array (UT)
3741 Asiz := Component_Size (UT);
3742 Indx := First_Index (UT);
3744 Ityp := Etype (Indx);
3746 -- If non-static bound, then we are not in the business of
3747 -- trying to check the length, and indeed an error will be
3748 -- issued elsewhere, since sizes of non-static array types
3749 -- cannot be set implicitly or explicitly.
3751 if not Is_Static_Subtype (Ityp) then
3755 -- Otherwise accumulate next dimension
3757 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
3758 Expr_Value (Type_Low_Bound (Ityp)) +
3762 exit when No (Indx);
3768 Error_Msg_Uint_1 := Asiz;
3770 ("size for& too small, minimum allowed is ^", N, T);
3771 Set_Esize (T, Asiz);
3772 Set_RM_Size (T, Asiz);
3776 -- All other composite types are ignored
3778 elsif Is_Composite_Type (UT) then
3781 -- For fixed-point types, don't check minimum if type is not frozen,
3782 -- since we don't know all the characteristics of the type that can
3783 -- affect the size (e.g. a specified small) till freeze time.
3785 elsif Is_Fixed_Point_Type (UT)
3786 and then not Is_Frozen (UT)
3790 -- Cases for which a minimum check is required
3793 -- Ignore if specified size is correct for the type
3795 if Known_Esize (UT) and then Siz = Esize (UT) then
3799 -- Otherwise get minimum size
3801 M := UI_From_Int (Minimum_Size (UT));
3805 -- Size is less than minimum size, but one possibility remains
3806 -- that we can manage with the new size if we bias the type.
3808 M := UI_From_Int (Minimum_Size (UT, Biased => True));
3811 Error_Msg_Uint_1 := M;
3813 ("size for& too small, minimum allowed is ^", N, T);
3823 -------------------------
3824 -- Get_Alignment_Value --
3825 -------------------------
3827 function Get_Alignment_Value (Expr : Node_Id) return Uint is
3828 Align : constant Uint := Static_Integer (Expr);
3831 if Align = No_Uint then
3834 elsif Align <= 0 then
3835 Error_Msg_N ("alignment value must be positive", Expr);
3839 for J in Int range 0 .. 64 loop
3841 M : constant Uint := Uint_2 ** J;
3844 exit when M = Align;
3848 ("alignment value must be power of 2", Expr);
3856 end Get_Alignment_Value;
3862 procedure Initialize is
3864 Unchecked_Conversions.Init;
3867 -------------------------
3868 -- Is_Operational_Item --
3869 -------------------------
3871 function Is_Operational_Item (N : Node_Id) return Boolean is
3873 if Nkind (N) /= N_Attribute_Definition_Clause then
3877 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
3879 return Id = Attribute_Input
3880 or else Id = Attribute_Output
3881 or else Id = Attribute_Read
3882 or else Id = Attribute_Write
3883 or else Id = Attribute_External_Tag;
3886 end Is_Operational_Item;
3892 function Minimum_Size
3894 Biased : Boolean := False) return Nat
3896 Lo : Uint := No_Uint;
3897 Hi : Uint := No_Uint;
3898 LoR : Ureal := No_Ureal;
3899 HiR : Ureal := No_Ureal;
3900 LoSet : Boolean := False;
3901 HiSet : Boolean := False;
3905 R_Typ : constant Entity_Id := Root_Type (T);
3908 -- If bad type, return 0
3910 if T = Any_Type then
3913 -- For generic types, just return zero. There cannot be any legitimate
3914 -- need to know such a size, but this routine may be called with a
3915 -- generic type as part of normal processing.
3917 elsif Is_Generic_Type (R_Typ)
3918 or else R_Typ = Any_Type
3922 -- Access types. Normally an access type cannot have a size smaller
3923 -- than the size of System.Address. The exception is on VMS, where
3924 -- we have short and long addresses, and it is possible for an access
3925 -- type to have a short address size (and thus be less than the size
3926 -- of System.Address itself). We simply skip the check for VMS, and
3927 -- leave it to the back end to do the check.
3929 elsif Is_Access_Type (T) then
3930 if OpenVMS_On_Target then
3933 return System_Address_Size;
3936 -- Floating-point types
3938 elsif Is_Floating_Point_Type (T) then
3939 return UI_To_Int (Esize (R_Typ));
3943 elsif Is_Discrete_Type (T) then
3945 -- The following loop is looking for the nearest compile time known
3946 -- bounds following the ancestor subtype chain. The idea is to find
3947 -- the most restrictive known bounds information.
3951 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3956 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
3957 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
3964 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
3965 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
3971 Ancest := Ancestor_Subtype (Ancest);
3974 Ancest := Base_Type (T);
3976 if Is_Generic_Type (Ancest) then
3982 -- Fixed-point types. We can't simply use Expr_Value to get the
3983 -- Corresponding_Integer_Value values of the bounds, since these do not
3984 -- get set till the type is frozen, and this routine can be called
3985 -- before the type is frozen. Similarly the test for bounds being static
3986 -- needs to include the case where we have unanalyzed real literals for
3989 elsif Is_Fixed_Point_Type (T) then
3991 -- The following loop is looking for the nearest compile time known
3992 -- bounds following the ancestor subtype chain. The idea is to find
3993 -- the most restrictive known bounds information.
3997 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4001 -- Note: In the following two tests for LoSet and HiSet, it may
4002 -- seem redundant to test for N_Real_Literal here since normally
4003 -- one would assume that the test for the value being known at
4004 -- compile time includes this case. However, there is a glitch.
4005 -- If the real literal comes from folding a non-static expression,
4006 -- then we don't consider any non- static expression to be known
4007 -- at compile time if we are in configurable run time mode (needed
4008 -- in some cases to give a clearer definition of what is and what
4009 -- is not accepted). So the test is indeed needed. Without it, we
4010 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
4013 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
4014 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
4016 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
4023 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
4024 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
4026 HiR := Expr_Value_R (Type_High_Bound (Ancest));
4032 Ancest := Ancestor_Subtype (Ancest);
4035 Ancest := Base_Type (T);
4037 if Is_Generic_Type (Ancest) then
4043 Lo := UR_To_Uint (LoR / Small_Value (T));
4044 Hi := UR_To_Uint (HiR / Small_Value (T));
4046 -- No other types allowed
4049 raise Program_Error;
4052 -- Fall through with Hi and Lo set. Deal with biased case
4055 and then not Is_Fixed_Point_Type (T)
4056 and then not (Is_Enumeration_Type (T)
4057 and then Has_Non_Standard_Rep (T)))
4058 or else Has_Biased_Representation (T)
4064 -- Signed case. Note that we consider types like range 1 .. -1 to be
4065 -- signed for the purpose of computing the size, since the bounds have
4066 -- to be accommodated in the base type.
4068 if Lo < 0 or else Hi < 0 then
4072 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
4073 -- Note that we accommodate the case where the bounds cross. This
4074 -- can happen either because of the way the bounds are declared
4075 -- or because of the algorithm in Freeze_Fixed_Point_Type.
4089 -- If both bounds are positive, make sure that both are represen-
4090 -- table in the case where the bounds are crossed. This can happen
4091 -- either because of the way the bounds are declared, or because of
4092 -- the algorithm in Freeze_Fixed_Point_Type.
4098 -- S = size, (can accommodate 0 .. (2**size - 1))
4101 while Hi >= Uint_2 ** S loop
4109 ---------------------------
4110 -- New_Stream_Subprogram --
4111 ---------------------------
4113 procedure New_Stream_Subprogram
4117 Nam : TSS_Name_Type)
4119 Loc : constant Source_Ptr := Sloc (N);
4120 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
4121 Subp_Id : Entity_Id;
4122 Subp_Decl : Node_Id;
4126 Defer_Declaration : constant Boolean :=
4127 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
4128 -- For a tagged type, there is a declaration for each stream attribute
4129 -- at the freeze point, and we must generate only a completion of this
4130 -- declaration. We do the same for private types, because the full view
4131 -- might be tagged. Otherwise we generate a declaration at the point of
4132 -- the attribute definition clause.
4134 function Build_Spec return Node_Id;
4135 -- Used for declaration and renaming declaration, so that this is
4136 -- treated as a renaming_as_body.
4142 function Build_Spec return Node_Id is
4143 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
4146 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
4149 Subp_Id := Make_Defining_Identifier (Loc, Sname);
4151 -- S : access Root_Stream_Type'Class
4153 Formals := New_List (
4154 Make_Parameter_Specification (Loc,
4155 Defining_Identifier =>
4156 Make_Defining_Identifier (Loc, Name_S),
4158 Make_Access_Definition (Loc,
4161 Designated_Type (Etype (F)), Loc))));
4163 if Nam = TSS_Stream_Input then
4164 Spec := Make_Function_Specification (Loc,
4165 Defining_Unit_Name => Subp_Id,
4166 Parameter_Specifications => Formals,
4167 Result_Definition => T_Ref);
4172 Make_Parameter_Specification (Loc,
4173 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
4174 Out_Present => Out_P,
4175 Parameter_Type => T_Ref));
4178 Make_Procedure_Specification (Loc,
4179 Defining_Unit_Name => Subp_Id,
4180 Parameter_Specifications => Formals);
4186 -- Start of processing for New_Stream_Subprogram
4189 F := First_Formal (Subp);
4191 if Ekind (Subp) = E_Procedure then
4192 Etyp := Etype (Next_Formal (F));
4194 Etyp := Etype (Subp);
4197 -- Prepare subprogram declaration and insert it as an action on the
4198 -- clause node. The visibility for this entity is used to test for
4199 -- visibility of the attribute definition clause (in the sense of
4200 -- 8.3(23) as amended by AI-195).
4202 if not Defer_Declaration then
4204 Make_Subprogram_Declaration (Loc,
4205 Specification => Build_Spec);
4207 -- For a tagged type, there is always a visible declaration for each
4208 -- stream TSS (it is a predefined primitive operation), and the
4209 -- completion of this declaration occurs at the freeze point, which is
4210 -- not always visible at places where the attribute definition clause is
4211 -- visible. So, we create a dummy entity here for the purpose of
4212 -- tracking the visibility of the attribute definition clause itself.
4216 Make_Defining_Identifier (Loc,
4217 Chars => New_External_Name (Sname, 'V'));
4219 Make_Object_Declaration (Loc,
4220 Defining_Identifier => Subp_Id,
4221 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
4224 Insert_Action (N, Subp_Decl);
4225 Set_Entity (N, Subp_Id);
4228 Make_Subprogram_Renaming_Declaration (Loc,
4229 Specification => Build_Spec,
4230 Name => New_Reference_To (Subp, Loc));
4232 if Defer_Declaration then
4233 Set_TSS (Base_Type (Ent), Subp_Id);
4235 Insert_Action (N, Subp_Decl);
4236 Copy_TSS (Subp_Id, Base_Type (Ent));
4238 end New_Stream_Subprogram;
4240 ------------------------
4241 -- Rep_Item_Too_Early --
4242 ------------------------
4244 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
4246 -- Cannot apply non-operational rep items to generic types
4248 if Is_Operational_Item (N) then
4252 and then Is_Generic_Type (Root_Type (T))
4254 Error_Msg_N ("representation item not allowed for generic type", N);
4258 -- Otherwise check for incomplete type
4260 if Is_Incomplete_Or_Private_Type (T)
4261 and then No (Underlying_Type (T))
4264 ("representation item must be after full type declaration", N);
4267 -- If the type has incomplete components, a representation clause is
4268 -- illegal but stream attributes and Convention pragmas are correct.
4270 elsif Has_Private_Component (T) then
4271 if Nkind (N) = N_Pragma then
4275 ("representation item must appear after type is fully defined",
4282 end Rep_Item_Too_Early;
4284 -----------------------
4285 -- Rep_Item_Too_Late --
4286 -----------------------
4288 function Rep_Item_Too_Late
4291 FOnly : Boolean := False) return Boolean
4294 Parent_Type : Entity_Id;
4297 -- Output the too late message. Note that this is not considered a
4298 -- serious error, since the effect is simply that we ignore the
4299 -- representation clause in this case.
4305 procedure Too_Late is
4307 Error_Msg_N ("|representation item appears too late!", N);
4310 -- Start of processing for Rep_Item_Too_Late
4313 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
4314 -- types, which may be frozen if they appear in a representation clause
4315 -- for a local type.
4318 and then not From_With_Type (T)
4321 S := First_Subtype (T);
4323 if Present (Freeze_Node (S)) then
4325 ("?no more representation items for }", Freeze_Node (S), S);
4330 -- Check for case of non-tagged derived type whose parent either has
4331 -- primitive operations, or is a by reference type (RM 13.1(10)).
4335 and then Is_Derived_Type (T)
4336 and then not Is_Tagged_Type (T)
4338 Parent_Type := Etype (Base_Type (T));
4340 if Has_Primitive_Operations (Parent_Type) then
4343 ("primitive operations already defined for&!", N, Parent_Type);
4346 elsif Is_By_Reference_Type (Parent_Type) then
4349 ("parent type & is a by reference type!", N, Parent_Type);
4354 -- No error, link item into head of chain of rep items for the entity,
4355 -- but avoid chaining if we have an overloadable entity, and the pragma
4356 -- is one that can apply to multiple overloaded entities.
4358 if Is_Overloadable (T)
4359 and then Nkind (N) = N_Pragma
4362 Pname : constant Name_Id := Pragma_Name (N);
4364 if Pname = Name_Convention or else
4365 Pname = Name_Import or else
4366 Pname = Name_Export or else
4367 Pname = Name_External or else
4368 Pname = Name_Interface
4375 Record_Rep_Item (T, N);
4377 end Rep_Item_Too_Late;
4379 -------------------------
4380 -- Same_Representation --
4381 -------------------------
4383 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
4384 T1 : constant Entity_Id := Underlying_Type (Typ1);
4385 T2 : constant Entity_Id := Underlying_Type (Typ2);
4388 -- A quick check, if base types are the same, then we definitely have
4389 -- the same representation, because the subtype specific representation
4390 -- attributes (Size and Alignment) do not affect representation from
4391 -- the point of view of this test.
4393 if Base_Type (T1) = Base_Type (T2) then
4396 elsif Is_Private_Type (Base_Type (T2))
4397 and then Base_Type (T1) = Full_View (Base_Type (T2))
4402 -- Tagged types never have differing representations
4404 if Is_Tagged_Type (T1) then
4408 -- Representations are definitely different if conventions differ
4410 if Convention (T1) /= Convention (T2) then
4414 -- Representations are different if component alignments differ
4416 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4418 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4419 and then Component_Alignment (T1) /= Component_Alignment (T2)
4424 -- For arrays, the only real issue is component size. If we know the
4425 -- component size for both arrays, and it is the same, then that's
4426 -- good enough to know we don't have a change of representation.
4428 if Is_Array_Type (T1) then
4429 if Known_Component_Size (T1)
4430 and then Known_Component_Size (T2)
4431 and then Component_Size (T1) = Component_Size (T2)
4437 -- Types definitely have same representation if neither has non-standard
4438 -- representation since default representations are always consistent.
4439 -- If only one has non-standard representation, and the other does not,
4440 -- then we consider that they do not have the same representation. They
4441 -- might, but there is no way of telling early enough.
4443 if Has_Non_Standard_Rep (T1) then
4444 if not Has_Non_Standard_Rep (T2) then
4448 return not Has_Non_Standard_Rep (T2);
4451 -- Here the two types both have non-standard representation, and we need
4452 -- to determine if they have the same non-standard representation.
4454 -- For arrays, we simply need to test if the component sizes are the
4455 -- same. Pragma Pack is reflected in modified component sizes, so this
4456 -- check also deals with pragma Pack.
4458 if Is_Array_Type (T1) then
4459 return Component_Size (T1) = Component_Size (T2);
4461 -- Tagged types always have the same representation, because it is not
4462 -- possible to specify different representations for common fields.
4464 elsif Is_Tagged_Type (T1) then
4467 -- Case of record types
4469 elsif Is_Record_Type (T1) then
4471 -- Packed status must conform
4473 if Is_Packed (T1) /= Is_Packed (T2) then
4476 -- Otherwise we must check components. Typ2 maybe a constrained
4477 -- subtype with fewer components, so we compare the components
4478 -- of the base types.
4481 Record_Case : declare
4482 CD1, CD2 : Entity_Id;
4484 function Same_Rep return Boolean;
4485 -- CD1 and CD2 are either components or discriminants. This
4486 -- function tests whether the two have the same representation
4492 function Same_Rep return Boolean is
4494 if No (Component_Clause (CD1)) then
4495 return No (Component_Clause (CD2));
4499 Present (Component_Clause (CD2))
4501 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4503 Esize (CD1) = Esize (CD2);
4507 -- Start of processing for Record_Case
4510 if Has_Discriminants (T1) then
4511 CD1 := First_Discriminant (T1);
4512 CD2 := First_Discriminant (T2);
4514 -- The number of discriminants may be different if the
4515 -- derived type has fewer (constrained by values). The
4516 -- invisible discriminants retain the representation of
4517 -- the original, so the discrepancy does not per se
4518 -- indicate a different representation.
4521 and then Present (CD2)
4523 if not Same_Rep then
4526 Next_Discriminant (CD1);
4527 Next_Discriminant (CD2);
4532 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4533 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4535 while Present (CD1) loop
4536 if not Same_Rep then
4539 Next_Component (CD1);
4540 Next_Component (CD2);
4548 -- For enumeration types, we must check each literal to see if the
4549 -- representation is the same. Note that we do not permit enumeration
4550 -- representation clauses for Character and Wide_Character, so these
4551 -- cases were already dealt with.
4553 elsif Is_Enumeration_Type (T1) then
4555 Enumeration_Case : declare
4559 L1 := First_Literal (T1);
4560 L2 := First_Literal (T2);
4562 while Present (L1) loop
4563 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4573 end Enumeration_Case;
4575 -- Any other types have the same representation for these purposes
4580 end Same_Representation;
4582 --------------------
4583 -- Set_Enum_Esize --
4584 --------------------
4586 procedure Set_Enum_Esize (T : Entity_Id) is
4594 -- Find the minimum standard size (8,16,32,64) that fits
4596 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4597 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4600 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4601 Sz := Standard_Character_Size; -- May be > 8 on some targets
4603 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4606 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4609 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4614 if Hi < Uint_2**08 then
4615 Sz := Standard_Character_Size; -- May be > 8 on some targets
4617 elsif Hi < Uint_2**16 then
4620 elsif Hi < Uint_2**32 then
4623 else pragma Assert (Hi < Uint_2**63);
4628 -- That minimum is the proper size unless we have a foreign convention
4629 -- and the size required is 32 or less, in which case we bump the size
4630 -- up to 32. This is required for C and C++ and seems reasonable for
4631 -- all other foreign conventions.
4633 if Has_Foreign_Convention (T)
4634 and then Esize (T) < Standard_Integer_Size
4636 Init_Esize (T, Standard_Integer_Size);
4642 ------------------------------
4643 -- Validate_Address_Clauses --
4644 ------------------------------
4646 procedure Validate_Address_Clauses is
4648 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4650 ACCR : Address_Clause_Check_Record
4651 renames Address_Clause_Checks.Table (J);
4662 -- Skip processing of this entry if warning already posted
4664 if not Address_Warning_Posted (ACCR.N) then
4666 Expr := Original_Node (Expression (ACCR.N));
4670 X_Alignment := Alignment (ACCR.X);
4671 Y_Alignment := Alignment (ACCR.Y);
4673 -- Similarly obtain sizes
4675 X_Size := Esize (ACCR.X);
4676 Y_Size := Esize (ACCR.Y);
4678 -- Check for large object overlaying smaller one
4681 and then X_Size > Uint_0
4682 and then X_Size > Y_Size
4685 ("?& overlays smaller object", ACCR.N, ACCR.X);
4687 ("\?program execution may be erroneous", ACCR.N);
4688 Error_Msg_Uint_1 := X_Size;
4690 ("\?size of & is ^", ACCR.N, ACCR.X);
4691 Error_Msg_Uint_1 := Y_Size;
4693 ("\?size of & is ^", ACCR.N, ACCR.Y);
4695 -- Check for inadequate alignment, both of the base object
4696 -- and of the offset, if any.
4698 -- Note: we do not check the alignment if we gave a size
4699 -- warning, since it would likely be redundant.
4701 elsif Y_Alignment /= Uint_0
4702 and then (Y_Alignment < X_Alignment
4705 Nkind (Expr) = N_Attribute_Reference
4707 Attribute_Name (Expr) = Name_Address
4709 Has_Compatible_Alignment
4710 (ACCR.X, Prefix (Expr))
4711 /= Known_Compatible))
4714 ("?specified address for& may be inconsistent "
4718 ("\?program execution may be erroneous (RM 13.3(27))",
4720 Error_Msg_Uint_1 := X_Alignment;
4722 ("\?alignment of & is ^",
4724 Error_Msg_Uint_1 := Y_Alignment;
4726 ("\?alignment of & is ^",
4728 if Y_Alignment >= X_Alignment then
4730 ("\?but offset is not multiple of alignment",
4737 end Validate_Address_Clauses;
4739 -----------------------------------
4740 -- Validate_Unchecked_Conversion --
4741 -----------------------------------
4743 procedure Validate_Unchecked_Conversion
4745 Act_Unit : Entity_Id)
4752 -- Obtain source and target types. Note that we call Ancestor_Subtype
4753 -- here because the processing for generic instantiation always makes
4754 -- subtypes, and we want the original frozen actual types.
4756 -- If we are dealing with private types, then do the check on their
4757 -- fully declared counterparts if the full declarations have been
4758 -- encountered (they don't have to be visible, but they must exist!)
4760 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
4762 if Is_Private_Type (Source)
4763 and then Present (Underlying_Type (Source))
4765 Source := Underlying_Type (Source);
4768 Target := Ancestor_Subtype (Etype (Act_Unit));
4770 -- If either type is generic, the instantiation happens within a generic
4771 -- unit, and there is nothing to check. The proper check
4772 -- will happen when the enclosing generic is instantiated.
4774 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
4778 if Is_Private_Type (Target)
4779 and then Present (Underlying_Type (Target))
4781 Target := Underlying_Type (Target);
4784 -- Source may be unconstrained array, but not target
4786 if Is_Array_Type (Target)
4787 and then not Is_Constrained (Target)
4790 ("unchecked conversion to unconstrained array not allowed", N);
4794 -- Warn if conversion between two different convention pointers
4796 if Is_Access_Type (Target)
4797 and then Is_Access_Type (Source)
4798 and then Convention (Target) /= Convention (Source)
4799 and then Warn_On_Unchecked_Conversion
4801 -- Give warnings for subprogram pointers only on most targets. The
4802 -- exception is VMS, where data pointers can have different lengths
4803 -- depending on the pointer convention.
4805 if Is_Access_Subprogram_Type (Target)
4806 or else Is_Access_Subprogram_Type (Source)
4807 or else OpenVMS_On_Target
4810 ("?conversion between pointers with different conventions!", N);
4814 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4815 -- warning when compiling GNAT-related sources.
4817 if Warn_On_Unchecked_Conversion
4818 and then not In_Predefined_Unit (N)
4819 and then RTU_Loaded (Ada_Calendar)
4821 (Chars (Source) = Name_Time
4823 Chars (Target) = Name_Time)
4825 -- If Ada.Calendar is loaded and the name of one of the operands is
4826 -- Time, there is a good chance that this is Ada.Calendar.Time.
4829 Calendar_Time : constant Entity_Id :=
4830 Full_View (RTE (RO_CA_Time));
4832 pragma Assert (Present (Calendar_Time));
4834 if Source = Calendar_Time
4835 or else Target = Calendar_Time
4838 ("?representation of 'Time values may change between " &
4839 "'G'N'A'T versions", N);
4844 -- Make entry in unchecked conversion table for later processing by
4845 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4846 -- (using values set by the back-end where possible). This is only done
4847 -- if the appropriate warning is active.
4849 if Warn_On_Unchecked_Conversion then
4850 Unchecked_Conversions.Append
4851 (New_Val => UC_Entry'
4856 -- If both sizes are known statically now, then back end annotation
4857 -- is not required to do a proper check but if either size is not
4858 -- known statically, then we need the annotation.
4860 if Known_Static_RM_Size (Source)
4861 and then Known_Static_RM_Size (Target)
4865 Back_Annotate_Rep_Info := True;
4869 -- If unchecked conversion to access type, and access type is declared
4870 -- in the same unit as the unchecked conversion, then set the
4871 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4874 if Is_Access_Type (Target) and then
4875 In_Same_Source_Unit (Target, N)
4877 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4880 -- Generate N_Validate_Unchecked_Conversion node for back end in
4881 -- case the back end needs to perform special validation checks.
4883 -- Shouldn't this be in Exp_Ch13, since the check only gets done
4884 -- if we have full expansion and the back end is called ???
4887 Make_Validate_Unchecked_Conversion (Sloc (N));
4888 Set_Source_Type (Vnode, Source);
4889 Set_Target_Type (Vnode, Target);
4891 -- If the unchecked conversion node is in a list, just insert before it.
4892 -- If not we have some strange case, not worth bothering about.
4894 if Is_List_Member (N) then
4895 Insert_After (N, Vnode);
4897 end Validate_Unchecked_Conversion;
4899 ------------------------------------
4900 -- Validate_Unchecked_Conversions --
4901 ------------------------------------
4903 procedure Validate_Unchecked_Conversions is
4905 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4907 T : UC_Entry renames Unchecked_Conversions.Table (N);
4909 Eloc : constant Source_Ptr := T.Eloc;
4910 Source : constant Entity_Id := T.Source;
4911 Target : constant Entity_Id := T.Target;
4917 -- This validation check, which warns if we have unequal sizes for
4918 -- unchecked conversion, and thus potentially implementation
4919 -- dependent semantics, is one of the few occasions on which we
4920 -- use the official RM size instead of Esize. See description in
4921 -- Einfo "Handling of Type'Size Values" for details.
4923 if Serious_Errors_Detected = 0
4924 and then Known_Static_RM_Size (Source)
4925 and then Known_Static_RM_Size (Target)
4927 -- Don't do the check if warnings off for either type, note the
4928 -- deliberate use of OR here instead of OR ELSE to get the flag
4929 -- Warnings_Off_Used set for both types if appropriate.
4931 and then not (Has_Warnings_Off (Source)
4933 Has_Warnings_Off (Target))
4935 Source_Siz := RM_Size (Source);
4936 Target_Siz := RM_Size (Target);
4938 if Source_Siz /= Target_Siz then
4940 ("?types for unchecked conversion have different sizes!",
4943 if All_Errors_Mode then
4944 Error_Msg_Name_1 := Chars (Source);
4945 Error_Msg_Uint_1 := Source_Siz;
4946 Error_Msg_Name_2 := Chars (Target);
4947 Error_Msg_Uint_2 := Target_Siz;
4948 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
4950 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4952 if Is_Discrete_Type (Source)
4953 and then Is_Discrete_Type (Target)
4955 if Source_Siz > Target_Siz then
4957 ("\?^ high order bits of source will be ignored!",
4960 elsif Is_Unsigned_Type (Source) then
4962 ("\?source will be extended with ^ high order " &
4963 "zero bits?!", Eloc);
4967 ("\?source will be extended with ^ high order " &
4972 elsif Source_Siz < Target_Siz then
4973 if Is_Discrete_Type (Target) then
4974 if Bytes_Big_Endian then
4976 ("\?target value will include ^ undefined " &
4981 ("\?target value will include ^ undefined " &
4988 ("\?^ trailing bits of target value will be " &
4989 "undefined!", Eloc);
4992 else pragma Assert (Source_Siz > Target_Siz);
4994 ("\?^ trailing bits of source will be ignored!",
5001 -- If both types are access types, we need to check the alignment.
5002 -- If the alignment of both is specified, we can do it here.
5004 if Serious_Errors_Detected = 0
5005 and then Ekind (Source) in Access_Kind
5006 and then Ekind (Target) in Access_Kind
5007 and then Target_Strict_Alignment
5008 and then Present (Designated_Type (Source))
5009 and then Present (Designated_Type (Target))
5012 D_Source : constant Entity_Id := Designated_Type (Source);
5013 D_Target : constant Entity_Id := Designated_Type (Target);
5016 if Known_Alignment (D_Source)
5017 and then Known_Alignment (D_Target)
5020 Source_Align : constant Uint := Alignment (D_Source);
5021 Target_Align : constant Uint := Alignment (D_Target);
5024 if Source_Align < Target_Align
5025 and then not Is_Tagged_Type (D_Source)
5027 -- Suppress warning if warnings suppressed on either
5028 -- type or either designated type. Note the use of
5029 -- OR here instead of OR ELSE. That is intentional,
5030 -- we would like to set flag Warnings_Off_Used in
5031 -- all types for which warnings are suppressed.
5033 and then not (Has_Warnings_Off (D_Source)
5035 Has_Warnings_Off (D_Target)
5037 Has_Warnings_Off (Source)
5039 Has_Warnings_Off (Target))
5041 Error_Msg_Uint_1 := Target_Align;
5042 Error_Msg_Uint_2 := Source_Align;
5043 Error_Msg_Node_1 := D_Target;
5044 Error_Msg_Node_2 := D_Source;
5046 ("?alignment of & (^) is stricter than " &
5047 "alignment of & (^)!", Eloc);
5049 ("\?resulting access value may have invalid " &
5050 "alignment!", Eloc);
5058 end Validate_Unchecked_Conversions;
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