1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Disp; use Exp_Disp;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
35 with Lib.Xref; use Lib.Xref;
36 with Namet; use Namet;
37 with Nlists; use Nlists;
38 with Nmake; use Nmake;
40 with Restrict; use Restrict;
41 with Rident; use Rident;
42 with Rtsfind; use Rtsfind;
44 with Sem_Aux; use Sem_Aux;
45 with Sem_Ch3; use Sem_Ch3;
46 with Sem_Ch8; use Sem_Ch8;
47 with Sem_Eval; use Sem_Eval;
48 with Sem_Res; use Sem_Res;
49 with Sem_Type; use Sem_Type;
50 with Sem_Util; use Sem_Util;
51 with Sem_Warn; use Sem_Warn;
52 with Snames; use Snames;
53 with Stand; use Stand;
54 with Sinfo; use Sinfo;
56 with Targparm; use Targparm;
57 with Ttypes; use Ttypes;
58 with Tbuild; use Tbuild;
59 with Urealp; use Urealp;
61 with GNAT.Heap_Sort_G;
63 package body Sem_Ch13 is
65 SSU : constant Pos := System_Storage_Unit;
66 -- Convenient short hand for commonly used constant
68 -----------------------
69 -- Local Subprograms --
70 -----------------------
72 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
73 -- This routine is called after setting the Esize of type entity Typ.
74 -- The purpose is to deal with the situation where an alignment has been
75 -- inherited from a derived type that is no longer appropriate for the
76 -- new Esize value. In this case, we reset the Alignment to unknown.
78 function Get_Alignment_Value (Expr : Node_Id) return Uint;
79 -- Given the expression for an alignment value, returns the corresponding
80 -- Uint value. If the value is inappropriate, then error messages are
81 -- posted as required, and a value of No_Uint is returned.
83 function Is_Operational_Item (N : Node_Id) return Boolean;
84 -- A specification for a stream attribute is allowed before the full
85 -- type is declared, as explained in AI-00137 and the corrigendum.
86 -- Attributes that do not specify a representation characteristic are
87 -- operational attributes.
89 procedure New_Stream_Subprogram
94 -- Create a subprogram renaming of a given stream attribute to the
95 -- designated subprogram and then in the tagged case, provide this as a
96 -- primitive operation, or in the non-tagged case make an appropriate TSS
97 -- entry. This is more properly an expansion activity than just semantics,
98 -- but the presence of user-defined stream functions for limited types is a
99 -- legality check, which is why this takes place here rather than in
100 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
101 -- function to be generated.
103 -- To avoid elaboration anomalies with freeze nodes, for untagged types
104 -- we generate both a subprogram declaration and a subprogram renaming
105 -- declaration, so that the attribute specification is handled as a
106 -- renaming_as_body. For tagged types, the specification is one of the
113 Biased : Boolean := True);
114 -- If Biased is True, sets Has_Biased_Representation flag for E, and
115 -- outputs a warning message at node N if Warn_On_Biased_Representation is
116 -- is True. This warning inserts the string Msg to describe the construct
119 ----------------------------------------------
120 -- Table for Validate_Unchecked_Conversions --
121 ----------------------------------------------
123 -- The following table collects unchecked conversions for validation.
124 -- Entries are made by Validate_Unchecked_Conversion and then the
125 -- call to Validate_Unchecked_Conversions does the actual error
126 -- checking and posting of warnings. The reason for this delayed
127 -- processing is to take advantage of back-annotations of size and
128 -- alignment values performed by the back end.
130 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
131 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
132 -- will already have modified all Sloc values if the -gnatD option is set.
134 type UC_Entry is record
135 Eloc : Source_Ptr; -- node used for posting warnings
136 Source : Entity_Id; -- source type for unchecked conversion
137 Target : Entity_Id; -- target type for unchecked conversion
140 package Unchecked_Conversions is new Table.Table (
141 Table_Component_Type => UC_Entry,
142 Table_Index_Type => Int,
143 Table_Low_Bound => 1,
145 Table_Increment => 200,
146 Table_Name => "Unchecked_Conversions");
148 ----------------------------------------
149 -- Table for Validate_Address_Clauses --
150 ----------------------------------------
152 -- If an address clause has the form
154 -- for X'Address use Expr
156 -- where Expr is of the form Y'Address or recursively is a reference
157 -- to a constant of either of these forms, and X and Y are entities of
158 -- objects, then if Y has a smaller alignment than X, that merits a
159 -- warning about possible bad alignment. The following table collects
160 -- address clauses of this kind. We put these in a table so that they
161 -- can be checked after the back end has completed annotation of the
162 -- alignments of objects, since we can catch more cases that way.
164 type Address_Clause_Check_Record is record
166 -- The address clause
169 -- The entity of the object overlaying Y
172 -- The entity of the object being overlaid
175 -- Whether the address is offseted within Y
178 package Address_Clause_Checks is new Table.Table (
179 Table_Component_Type => Address_Clause_Check_Record,
180 Table_Index_Type => Int,
181 Table_Low_Bound => 1,
183 Table_Increment => 200,
184 Table_Name => "Address_Clause_Checks");
186 -----------------------------------------
187 -- Adjust_Record_For_Reverse_Bit_Order --
188 -----------------------------------------
190 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
195 -- Processing depends on version of Ada
197 -- For Ada 95, we just renumber bits within a storage unit. We do the
198 -- same for Ada 83 mode, since we recognize pragma Bit_Order in Ada 83,
199 -- and are free to add this extension.
201 if Ada_Version < Ada_2005 then
202 Comp := First_Component_Or_Discriminant (R);
203 while Present (Comp) loop
204 CC := Component_Clause (Comp);
206 -- If component clause is present, then deal with the non-default
207 -- bit order case for Ada 95 mode.
209 -- We only do this processing for the base type, and in fact that
210 -- is important, since otherwise if there are record subtypes, we
211 -- could reverse the bits once for each subtype, which is wrong.
214 and then Ekind (R) = E_Record_Type
217 CFB : constant Uint := Component_Bit_Offset (Comp);
218 CSZ : constant Uint := Esize (Comp);
219 CLC : constant Node_Id := Component_Clause (Comp);
220 Pos : constant Node_Id := Position (CLC);
221 FB : constant Node_Id := First_Bit (CLC);
223 Storage_Unit_Offset : constant Uint :=
224 CFB / System_Storage_Unit;
226 Start_Bit : constant Uint :=
227 CFB mod System_Storage_Unit;
230 -- Cases where field goes over storage unit boundary
232 if Start_Bit + CSZ > System_Storage_Unit then
234 -- Allow multi-byte field but generate warning
236 if Start_Bit mod System_Storage_Unit = 0
237 and then CSZ mod System_Storage_Unit = 0
240 ("multi-byte field specified with non-standard"
241 & " Bit_Order?", CLC);
243 if Bytes_Big_Endian then
245 ("bytes are not reversed "
246 & "(component is big-endian)?", CLC);
249 ("bytes are not reversed "
250 & "(component is little-endian)?", CLC);
253 -- Do not allow non-contiguous field
257 ("attempt to specify non-contiguous field "
258 & "not permitted", CLC);
260 ("\caused by non-standard Bit_Order "
263 ("\consider possibility of using "
264 & "Ada 2005 mode here", CLC);
267 -- Case where field fits in one storage unit
270 -- Give warning if suspicious component clause
272 if Intval (FB) >= System_Storage_Unit
273 and then Warn_On_Reverse_Bit_Order
276 ("?Bit_Order clause does not affect " &
277 "byte ordering", Pos);
279 Intval (Pos) + Intval (FB) /
282 ("?position normalized to ^ before bit " &
283 "order interpreted", Pos);
286 -- Here is where we fix up the Component_Bit_Offset value
287 -- to account for the reverse bit order. Some examples of
288 -- what needs to be done are:
290 -- First_Bit .. Last_Bit Component_Bit_Offset
302 -- The rule is that the first bit is is obtained by
303 -- subtracting the old ending bit from storage_unit - 1.
305 Set_Component_Bit_Offset
307 (Storage_Unit_Offset * System_Storage_Unit) +
308 (System_Storage_Unit - 1) -
309 (Start_Bit + CSZ - 1));
311 Set_Normalized_First_Bit
313 Component_Bit_Offset (Comp) mod
314 System_Storage_Unit);
319 Next_Component_Or_Discriminant (Comp);
322 -- For Ada 2005, we do machine scalar processing, as fully described In
323 -- AI-133. This involves gathering all components which start at the
324 -- same byte offset and processing them together. Same approach is still
325 -- valid in later versions including Ada 2012.
329 Max_Machine_Scalar_Size : constant Uint :=
331 (Standard_Long_Long_Integer_Size);
332 -- We use this as the maximum machine scalar size
335 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
338 -- This first loop through components does two things. First it
339 -- deals with the case of components with component clauses whose
340 -- length is greater than the maximum machine scalar size (either
341 -- accepting them or rejecting as needed). Second, it counts the
342 -- number of components with component clauses whose length does
343 -- not exceed this maximum for later processing.
346 Comp := First_Component_Or_Discriminant (R);
347 while Present (Comp) loop
348 CC := Component_Clause (Comp);
352 Fbit : constant Uint :=
353 Static_Integer (First_Bit (CC));
356 -- Case of component with size > max machine scalar
358 if Esize (Comp) > Max_Machine_Scalar_Size then
360 -- Must begin on byte boundary
362 if Fbit mod SSU /= 0 then
364 ("illegal first bit value for "
365 & "reverse bit order",
367 Error_Msg_Uint_1 := SSU;
368 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
371 ("\must be a multiple of ^ "
372 & "if size greater than ^",
375 -- Must end on byte boundary
377 elsif Esize (Comp) mod SSU /= 0 then
379 ("illegal last bit value for "
380 & "reverse bit order",
382 Error_Msg_Uint_1 := SSU;
383 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
386 ("\must be a multiple of ^ if size "
390 -- OK, give warning if enabled
392 elsif Warn_On_Reverse_Bit_Order then
394 ("multi-byte field specified with "
395 & " non-standard Bit_Order?", CC);
397 if Bytes_Big_Endian then
399 ("\bytes are not reversed "
400 & "(component is big-endian)?", CC);
403 ("\bytes are not reversed "
404 & "(component is little-endian)?", CC);
408 -- Case where size is not greater than max machine
409 -- scalar. For now, we just count these.
412 Num_CC := Num_CC + 1;
417 Next_Component_Or_Discriminant (Comp);
420 -- We need to sort the component clauses on the basis of the
421 -- Position values in the clause, so we can group clauses with
422 -- the same Position. together to determine the relevant machine
426 Comps : array (0 .. Num_CC) of Entity_Id;
427 -- Array to collect component and discriminant entities. The
428 -- data starts at index 1, the 0'th entry is for the sort
431 function CP_Lt (Op1, Op2 : Natural) return Boolean;
432 -- Compare routine for Sort
434 procedure CP_Move (From : Natural; To : Natural);
435 -- Move routine for Sort
437 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
441 -- Start and stop positions in the component list of the set of
442 -- components with the same starting position (that constitute
443 -- components in a single machine scalar).
446 -- Maximum last bit value of any component in this set
449 -- Corresponding machine scalar size
455 function CP_Lt (Op1, Op2 : Natural) return Boolean is
457 return Position (Component_Clause (Comps (Op1))) <
458 Position (Component_Clause (Comps (Op2)));
465 procedure CP_Move (From : Natural; To : Natural) is
467 Comps (To) := Comps (From);
470 -- Start of processing for Sort_CC
473 -- Collect the component clauses
476 Comp := First_Component_Or_Discriminant (R);
477 while Present (Comp) loop
478 if Present (Component_Clause (Comp))
479 and then Esize (Comp) <= Max_Machine_Scalar_Size
481 Num_CC := Num_CC + 1;
482 Comps (Num_CC) := Comp;
485 Next_Component_Or_Discriminant (Comp);
488 -- Sort by ascending position number
490 Sorting.Sort (Num_CC);
492 -- We now have all the components whose size does not exceed
493 -- the max machine scalar value, sorted by starting position.
494 -- In this loop we gather groups of clauses starting at the
495 -- same position, to process them in accordance with AI-133.
498 while Stop < Num_CC loop
503 (Last_Bit (Component_Clause (Comps (Start))));
504 while Stop < Num_CC loop
506 (Position (Component_Clause (Comps (Stop + 1)))) =
508 (Position (Component_Clause (Comps (Stop))))
516 (Component_Clause (Comps (Stop)))));
522 -- Now we have a group of component clauses from Start to
523 -- Stop whose positions are identical, and MaxL is the
524 -- maximum last bit value of any of these components.
526 -- We need to determine the corresponding machine scalar
527 -- size. This loop assumes that machine scalar sizes are
528 -- even, and that each possible machine scalar has twice
529 -- as many bits as the next smaller one.
531 MSS := Max_Machine_Scalar_Size;
533 and then (MSS / 2) >= SSU
534 and then (MSS / 2) > MaxL
539 -- Here is where we fix up the Component_Bit_Offset value
540 -- to account for the reverse bit order. Some examples of
541 -- what needs to be done for the case of a machine scalar
544 -- First_Bit .. Last_Bit Component_Bit_Offset
556 -- The rule is that the first bit is obtained by subtracting
557 -- the old ending bit from machine scalar size - 1.
559 for C in Start .. Stop loop
561 Comp : constant Entity_Id := Comps (C);
562 CC : constant Node_Id :=
563 Component_Clause (Comp);
564 LB : constant Uint :=
565 Static_Integer (Last_Bit (CC));
566 NFB : constant Uint := MSS - Uint_1 - LB;
567 NLB : constant Uint := NFB + Esize (Comp) - 1;
568 Pos : constant Uint :=
569 Static_Integer (Position (CC));
572 if Warn_On_Reverse_Bit_Order then
573 Error_Msg_Uint_1 := MSS;
575 ("info: reverse bit order in machine " &
576 "scalar of length^?", First_Bit (CC));
577 Error_Msg_Uint_1 := NFB;
578 Error_Msg_Uint_2 := NLB;
580 if Bytes_Big_Endian then
582 ("?\info: big-endian range for "
583 & "component & is ^ .. ^",
584 First_Bit (CC), Comp);
587 ("?\info: little-endian range "
588 & "for component & is ^ .. ^",
589 First_Bit (CC), Comp);
593 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
594 Set_Normalized_First_Bit (Comp, NFB mod SSU);
601 end Adjust_Record_For_Reverse_Bit_Order;
603 --------------------------------------
604 -- Alignment_Check_For_Esize_Change --
605 --------------------------------------
607 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
609 -- If the alignment is known, and not set by a rep clause, and is
610 -- inconsistent with the size being set, then reset it to unknown,
611 -- we assume in this case that the size overrides the inherited
612 -- alignment, and that the alignment must be recomputed.
614 if Known_Alignment (Typ)
615 and then not Has_Alignment_Clause (Typ)
616 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
618 Init_Alignment (Typ);
620 end Alignment_Check_For_Esize_Change;
622 -----------------------
623 -- Analyze_At_Clause --
624 -----------------------
626 -- An at clause is replaced by the corresponding Address attribute
627 -- definition clause that is the preferred approach in Ada 95.
629 procedure Analyze_At_Clause (N : Node_Id) is
630 CS : constant Boolean := Comes_From_Source (N);
633 -- This is an obsolescent feature
635 Check_Restriction (No_Obsolescent_Features, N);
637 if Warn_On_Obsolescent_Feature then
639 ("at clause is an obsolescent feature (RM J.7(2))?", N);
641 ("\use address attribute definition clause instead?", N);
644 -- Rewrite as address clause
647 Make_Attribute_Definition_Clause (Sloc (N),
648 Name => Identifier (N),
649 Chars => Name_Address,
650 Expression => Expression (N)));
652 -- We preserve Comes_From_Source, since logically the clause still
653 -- comes from the source program even though it is changed in form.
655 Set_Comes_From_Source (N, CS);
657 -- Analyze rewritten clause
659 Analyze_Attribute_Definition_Clause (N);
660 end Analyze_At_Clause;
662 -----------------------------------------
663 -- Analyze_Attribute_Definition_Clause --
664 -----------------------------------------
666 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
667 Loc : constant Source_Ptr := Sloc (N);
668 Nam : constant Node_Id := Name (N);
669 Attr : constant Name_Id := Chars (N);
670 Expr : constant Node_Id := Expression (N);
671 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
675 FOnly : Boolean := False;
676 -- Reset to True for subtype specific attribute (Alignment, Size)
677 -- and for stream attributes, i.e. those cases where in the call
678 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
679 -- rules are checked. Note that the case of stream attributes is not
680 -- clear from the RM, but see AI95-00137. Also, the RM seems to
681 -- disallow Storage_Size for derived task types, but that is also
682 -- clearly unintentional.
684 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
685 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
686 -- definition clauses.
688 -----------------------------------
689 -- Analyze_Stream_TSS_Definition --
690 -----------------------------------
692 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
693 Subp : Entity_Id := Empty;
698 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
700 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
701 -- Return true if the entity is a subprogram with an appropriate
702 -- profile for the attribute being defined.
704 ----------------------
705 -- Has_Good_Profile --
706 ----------------------
708 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
710 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
711 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
712 (False => E_Procedure, True => E_Function);
716 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
720 F := First_Formal (Subp);
723 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
724 or else Designated_Type (Etype (F)) /=
725 Class_Wide_Type (RTE (RE_Root_Stream_Type))
730 if not Is_Function then
734 Expected_Mode : constant array (Boolean) of Entity_Kind :=
735 (False => E_In_Parameter,
736 True => E_Out_Parameter);
738 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
749 return Base_Type (Typ) = Base_Type (Ent)
750 and then No (Next_Formal (F));
751 end Has_Good_Profile;
753 -- Start of processing for Analyze_Stream_TSS_Definition
758 if not Is_Type (U_Ent) then
759 Error_Msg_N ("local name must be a subtype", Nam);
763 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
765 -- If Pnam is present, it can be either inherited from an ancestor
766 -- type (in which case it is legal to redefine it for this type), or
767 -- be a previous definition of the attribute for the same type (in
768 -- which case it is illegal).
770 -- In the first case, it will have been analyzed already, and we
771 -- can check that its profile does not match the expected profile
772 -- for a stream attribute of U_Ent. In the second case, either Pnam
773 -- has been analyzed (and has the expected profile), or it has not
774 -- been analyzed yet (case of a type that has not been frozen yet
775 -- and for which the stream attribute has been set using Set_TSS).
778 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
780 Error_Msg_Sloc := Sloc (Pnam);
781 Error_Msg_Name_1 := Attr;
782 Error_Msg_N ("% attribute already defined #", Nam);
788 if Is_Entity_Name (Expr) then
789 if not Is_Overloaded (Expr) then
790 if Has_Good_Profile (Entity (Expr)) then
791 Subp := Entity (Expr);
795 Get_First_Interp (Expr, I, It);
796 while Present (It.Nam) loop
797 if Has_Good_Profile (It.Nam) then
802 Get_Next_Interp (I, It);
807 if Present (Subp) then
808 if Is_Abstract_Subprogram (Subp) then
809 Error_Msg_N ("stream subprogram must not be abstract", Expr);
813 Set_Entity (Expr, Subp);
814 Set_Etype (Expr, Etype (Subp));
816 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
819 Error_Msg_Name_1 := Attr;
820 Error_Msg_N ("incorrect expression for% attribute", Expr);
822 end Analyze_Stream_TSS_Definition;
824 -- Start of processing for Analyze_Attribute_Definition_Clause
827 -- Process Ignore_Rep_Clauses option
829 if Ignore_Rep_Clauses then
832 -- The following should be ignored. They do not affect legality
833 -- and may be target dependent. The basic idea of -gnatI is to
834 -- ignore any rep clauses that may be target dependent but do not
835 -- affect legality (except possibly to be rejected because they
836 -- are incompatible with the compilation target).
838 when Attribute_Alignment |
839 Attribute_Bit_Order |
840 Attribute_Component_Size |
841 Attribute_Machine_Radix |
842 Attribute_Object_Size |
845 Attribute_Stream_Size |
846 Attribute_Value_Size =>
848 Rewrite (N, Make_Null_Statement (Sloc (N)));
851 -- The following should not be ignored, because in the first place
852 -- they are reasonably portable, and should not cause problems in
853 -- compiling code from another target, and also they do affect
854 -- legality, e.g. failing to provide a stream attribute for a
855 -- type may make a program illegal.
857 when Attribute_External_Tag |
861 Attribute_Storage_Pool |
862 Attribute_Storage_Size |
866 -- Other cases are errors ("attribute& cannot be set with
867 -- definition clause"), which will be caught below.
877 if Rep_Item_Too_Early (Ent, N) then
881 -- Rep clause applies to full view of incomplete type or private type if
882 -- we have one (if not, this is a premature use of the type). However,
883 -- certain semantic checks need to be done on the specified entity (i.e.
884 -- the private view), so we save it in Ent.
886 if Is_Private_Type (Ent)
887 and then Is_Derived_Type (Ent)
888 and then not Is_Tagged_Type (Ent)
889 and then No (Full_View (Ent))
891 -- If this is a private type whose completion is a derivation from
892 -- another private type, there is no full view, and the attribute
893 -- belongs to the type itself, not its underlying parent.
897 elsif Ekind (Ent) = E_Incomplete_Type then
899 -- The attribute applies to the full view, set the entity of the
900 -- attribute definition accordingly.
902 Ent := Underlying_Type (Ent);
904 Set_Entity (Nam, Ent);
907 U_Ent := Underlying_Type (Ent);
910 -- Complete other routine error checks
912 if Etype (Nam) = Any_Type then
915 elsif Scope (Ent) /= Current_Scope then
916 Error_Msg_N ("entity must be declared in this scope", Nam);
919 elsif No (U_Ent) then
922 elsif Is_Type (U_Ent)
923 and then not Is_First_Subtype (U_Ent)
924 and then Id /= Attribute_Object_Size
925 and then Id /= Attribute_Value_Size
926 and then not From_At_Mod (N)
928 Error_Msg_N ("cannot specify attribute for subtype", Nam);
932 -- Switch on particular attribute
940 -- Address attribute definition clause
942 when Attribute_Address => Address : begin
944 -- A little error check, catch for X'Address use X'Address;
946 if Nkind (Nam) = N_Identifier
947 and then Nkind (Expr) = N_Attribute_Reference
948 and then Attribute_Name (Expr) = Name_Address
949 and then Nkind (Prefix (Expr)) = N_Identifier
950 and then Chars (Nam) = Chars (Prefix (Expr))
953 ("address for & is self-referencing", Prefix (Expr), Ent);
957 -- Not that special case, carry on with analysis of expression
959 Analyze_And_Resolve (Expr, RTE (RE_Address));
961 -- Even when ignoring rep clauses we need to indicate that the
962 -- entity has an address clause and thus it is legal to declare
965 if Ignore_Rep_Clauses then
966 if Ekind_In (U_Ent, E_Variable, E_Constant) then
967 Record_Rep_Item (U_Ent, N);
973 if Present (Address_Clause (U_Ent)) then
974 Error_Msg_N ("address already given for &", Nam);
976 -- Case of address clause for subprogram
978 elsif Is_Subprogram (U_Ent) then
979 if Has_Homonym (U_Ent) then
981 ("address clause cannot be given " &
982 "for overloaded subprogram",
987 -- For subprograms, all address clauses are permitted, and we
988 -- mark the subprogram as having a deferred freeze so that Gigi
989 -- will not elaborate it too soon.
991 -- Above needs more comments, what is too soon about???
993 Set_Has_Delayed_Freeze (U_Ent);
995 -- Case of address clause for entry
997 elsif Ekind (U_Ent) = E_Entry then
998 if Nkind (Parent (N)) = N_Task_Body then
1000 ("entry address must be specified in task spec", Nam);
1004 -- For entries, we require a constant address
1006 Check_Constant_Address_Clause (Expr, U_Ent);
1008 -- Special checks for task types
1010 if Is_Task_Type (Scope (U_Ent))
1011 and then Comes_From_Source (Scope (U_Ent))
1014 ("?entry address declared for entry in task type", N);
1016 ("\?only one task can be declared of this type", N);
1019 -- Entry address clauses are obsolescent
1021 Check_Restriction (No_Obsolescent_Features, N);
1023 if Warn_On_Obsolescent_Feature then
1025 ("attaching interrupt to task entry is an " &
1026 "obsolescent feature (RM J.7.1)?", N);
1028 ("\use interrupt procedure instead?", N);
1031 -- Case of an address clause for a controlled object which we
1032 -- consider to be erroneous.
1034 elsif Is_Controlled (Etype (U_Ent))
1035 or else Has_Controlled_Component (Etype (U_Ent))
1038 ("?controlled object& must not be overlaid", Nam, U_Ent);
1040 ("\?Program_Error will be raised at run time", Nam);
1041 Insert_Action (Declaration_Node (U_Ent),
1042 Make_Raise_Program_Error (Loc,
1043 Reason => PE_Overlaid_Controlled_Object));
1046 -- Case of address clause for a (non-controlled) object
1049 Ekind (U_Ent) = E_Variable
1051 Ekind (U_Ent) = E_Constant
1054 Expr : constant Node_Id := Expression (N);
1059 -- Exported variables cannot have an address clause, because
1060 -- this cancels the effect of the pragma Export.
1062 if Is_Exported (U_Ent) then
1064 ("cannot export object with address clause", Nam);
1068 Find_Overlaid_Entity (N, O_Ent, Off);
1070 -- Overlaying controlled objects is erroneous
1073 and then (Has_Controlled_Component (Etype (O_Ent))
1074 or else Is_Controlled (Etype (O_Ent)))
1077 ("?cannot overlay with controlled object", Expr);
1079 ("\?Program_Error will be raised at run time", Expr);
1080 Insert_Action (Declaration_Node (U_Ent),
1081 Make_Raise_Program_Error (Loc,
1082 Reason => PE_Overlaid_Controlled_Object));
1085 elsif Present (O_Ent)
1086 and then Ekind (U_Ent) = E_Constant
1087 and then not Is_Constant_Object (O_Ent)
1089 Error_Msg_N ("constant overlays a variable?", Expr);
1091 elsif Present (Renamed_Object (U_Ent)) then
1093 ("address clause not allowed"
1094 & " for a renaming declaration (RM 13.1(6))", Nam);
1097 -- Imported variables can have an address clause, but then
1098 -- the import is pretty meaningless except to suppress
1099 -- initializations, so we do not need such variables to
1100 -- be statically allocated (and in fact it causes trouble
1101 -- if the address clause is a local value).
1103 elsif Is_Imported (U_Ent) then
1104 Set_Is_Statically_Allocated (U_Ent, False);
1107 -- We mark a possible modification of a variable with an
1108 -- address clause, since it is likely aliasing is occurring.
1110 Note_Possible_Modification (Nam, Sure => False);
1112 -- Here we are checking for explicit overlap of one variable
1113 -- by another, and if we find this then mark the overlapped
1114 -- variable as also being volatile to prevent unwanted
1115 -- optimizations. This is a significant pessimization so
1116 -- avoid it when there is an offset, i.e. when the object
1117 -- is composite; they cannot be optimized easily anyway.
1120 and then Is_Object (O_Ent)
1123 Set_Treat_As_Volatile (O_Ent);
1126 -- Legality checks on the address clause for initialized
1127 -- objects is deferred until the freeze point, because
1128 -- a subsequent pragma might indicate that the object is
1129 -- imported and thus not initialized.
1131 Set_Has_Delayed_Freeze (U_Ent);
1133 -- If an initialization call has been generated for this
1134 -- object, it needs to be deferred to after the freeze node
1135 -- we have just now added, otherwise GIGI will see a
1136 -- reference to the variable (as actual to the IP call)
1137 -- before its definition.
1140 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1142 if Present (Init_Call) then
1144 Append_Freeze_Action (U_Ent, Init_Call);
1148 if Is_Exported (U_Ent) then
1150 ("& cannot be exported if an address clause is given",
1153 ("\define and export a variable " &
1154 "that holds its address instead",
1158 -- Entity has delayed freeze, so we will generate an
1159 -- alignment check at the freeze point unless suppressed.
1161 if not Range_Checks_Suppressed (U_Ent)
1162 and then not Alignment_Checks_Suppressed (U_Ent)
1164 Set_Check_Address_Alignment (N);
1167 -- Kill the size check code, since we are not allocating
1168 -- the variable, it is somewhere else.
1170 Kill_Size_Check_Code (U_Ent);
1172 -- If the address clause is of the form:
1174 -- for Y'Address use X'Address
1178 -- Const : constant Address := X'Address;
1180 -- for Y'Address use Const;
1182 -- then we make an entry in the table for checking the size
1183 -- and alignment of the overlaying variable. We defer this
1184 -- check till after code generation to take full advantage
1185 -- of the annotation done by the back end. This entry is
1186 -- only made if the address clause comes from source.
1187 -- If the entity has a generic type, the check will be
1188 -- performed in the instance if the actual type justifies
1189 -- it, and we do not insert the clause in the table to
1190 -- prevent spurious warnings.
1192 if Address_Clause_Overlay_Warnings
1193 and then Comes_From_Source (N)
1194 and then Present (O_Ent)
1195 and then Is_Object (O_Ent)
1197 if not Is_Generic_Type (Etype (U_Ent)) then
1198 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1201 -- If variable overlays a constant view, and we are
1202 -- warning on overlays, then mark the variable as
1203 -- overlaying a constant (we will give warnings later
1204 -- if this variable is assigned).
1206 if Is_Constant_Object (O_Ent)
1207 and then Ekind (U_Ent) = E_Variable
1209 Set_Overlays_Constant (U_Ent);
1214 -- Not a valid entity for an address clause
1217 Error_Msg_N ("address cannot be given for &", Nam);
1225 -- Alignment attribute definition clause
1227 when Attribute_Alignment => Alignment : declare
1228 Align : constant Uint := Get_Alignment_Value (Expr);
1233 if not Is_Type (U_Ent)
1234 and then Ekind (U_Ent) /= E_Variable
1235 and then Ekind (U_Ent) /= E_Constant
1237 Error_Msg_N ("alignment cannot be given for &", Nam);
1239 elsif Has_Alignment_Clause (U_Ent) then
1240 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1241 Error_Msg_N ("alignment clause previously given#", N);
1243 elsif Align /= No_Uint then
1244 Set_Has_Alignment_Clause (U_Ent);
1245 Set_Alignment (U_Ent, Align);
1247 -- For an array type, U_Ent is the first subtype. In that case,
1248 -- also set the alignment of the anonymous base type so that
1249 -- other subtypes (such as the itypes for aggregates of the
1250 -- type) also receive the expected alignment.
1252 if Is_Array_Type (U_Ent) then
1253 Set_Alignment (Base_Type (U_Ent), Align);
1262 -- Bit_Order attribute definition clause
1264 when Attribute_Bit_Order => Bit_Order : declare
1266 if not Is_Record_Type (U_Ent) then
1268 ("Bit_Order can only be defined for record type", Nam);
1271 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1273 if Etype (Expr) = Any_Type then
1276 elsif not Is_Static_Expression (Expr) then
1277 Flag_Non_Static_Expr
1278 ("Bit_Order requires static expression!", Expr);
1281 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1282 Set_Reverse_Bit_Order (U_Ent, True);
1288 --------------------
1289 -- Component_Size --
1290 --------------------
1292 -- Component_Size attribute definition clause
1294 when Attribute_Component_Size => Component_Size_Case : declare
1295 Csize : constant Uint := Static_Integer (Expr);
1299 New_Ctyp : Entity_Id;
1303 if not Is_Array_Type (U_Ent) then
1304 Error_Msg_N ("component size requires array type", Nam);
1308 Btype := Base_Type (U_Ent);
1309 Ctyp := Component_Type (Btype);
1311 if Has_Component_Size_Clause (Btype) then
1313 ("component size clause for& previously given", Nam);
1315 elsif Rep_Item_Too_Early (Btype, N) then
1318 elsif Csize /= No_Uint then
1319 Check_Size (Expr, Ctyp, Csize, Biased);
1321 -- For the biased case, build a declaration for a subtype
1322 -- that will be used to represent the biased subtype that
1323 -- reflects the biased representation of components. We need
1324 -- this subtype to get proper conversions on referencing
1325 -- elements of the array. Note that component size clauses
1326 -- are ignored in VM mode.
1328 if VM_Target = No_VM then
1331 Make_Defining_Identifier (Loc,
1333 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1336 Make_Subtype_Declaration (Loc,
1337 Defining_Identifier => New_Ctyp,
1338 Subtype_Indication =>
1339 New_Occurrence_Of (Component_Type (Btype), Loc));
1341 Set_Parent (Decl, N);
1342 Analyze (Decl, Suppress => All_Checks);
1344 Set_Has_Delayed_Freeze (New_Ctyp, False);
1345 Set_Esize (New_Ctyp, Csize);
1346 Set_RM_Size (New_Ctyp, Csize);
1347 Init_Alignment (New_Ctyp);
1348 Set_Is_Itype (New_Ctyp, True);
1349 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1351 Set_Component_Type (Btype, New_Ctyp);
1352 Set_Biased (New_Ctyp, N, "component size clause");
1355 Set_Component_Size (Btype, Csize);
1357 -- For VM case, we ignore component size clauses
1360 -- Give a warning unless we are in GNAT mode, in which case
1361 -- the warning is suppressed since it is not useful.
1363 if not GNAT_Mode then
1365 ("?component size ignored in this configuration", N);
1369 -- Deal with warning on overridden size
1371 if Warn_On_Overridden_Size
1372 and then Has_Size_Clause (Ctyp)
1373 and then RM_Size (Ctyp) /= Csize
1376 ("?component size overrides size clause for&",
1380 Set_Has_Component_Size_Clause (Btype, True);
1381 Set_Has_Non_Standard_Rep (Btype, True);
1383 end Component_Size_Case;
1389 when Attribute_External_Tag => External_Tag :
1391 if not Is_Tagged_Type (U_Ent) then
1392 Error_Msg_N ("should be a tagged type", Nam);
1395 Analyze_And_Resolve (Expr, Standard_String);
1397 if not Is_Static_Expression (Expr) then
1398 Flag_Non_Static_Expr
1399 ("static string required for tag name!", Nam);
1402 if VM_Target = No_VM then
1403 Set_Has_External_Tag_Rep_Clause (U_Ent);
1405 Error_Msg_Name_1 := Attr;
1407 ("% attribute unsupported in this configuration", Nam);
1410 if not Is_Library_Level_Entity (U_Ent) then
1412 ("?non-unique external tag supplied for &", N, U_Ent);
1414 ("?\same external tag applies to all subprogram calls", N);
1416 ("?\corresponding internal tag cannot be obtained", N);
1424 when Attribute_Input =>
1425 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1426 Set_Has_Specified_Stream_Input (Ent);
1432 -- Machine radix attribute definition clause
1434 when Attribute_Machine_Radix => Machine_Radix : declare
1435 Radix : constant Uint := Static_Integer (Expr);
1438 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1439 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1441 elsif Has_Machine_Radix_Clause (U_Ent) then
1442 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1443 Error_Msg_N ("machine radix clause previously given#", N);
1445 elsif Radix /= No_Uint then
1446 Set_Has_Machine_Radix_Clause (U_Ent);
1447 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1451 elsif Radix = 10 then
1452 Set_Machine_Radix_10 (U_Ent);
1454 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1463 -- Object_Size attribute definition clause
1465 when Attribute_Object_Size => Object_Size : declare
1466 Size : constant Uint := Static_Integer (Expr);
1469 pragma Warnings (Off, Biased);
1472 if not Is_Type (U_Ent) then
1473 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1475 elsif Has_Object_Size_Clause (U_Ent) then
1476 Error_Msg_N ("Object_Size already given for &", Nam);
1479 Check_Size (Expr, U_Ent, Size, Biased);
1487 UI_Mod (Size, 64) /= 0
1490 ("Object_Size must be 8, 16, 32, or multiple of 64",
1494 Set_Esize (U_Ent, Size);
1495 Set_Has_Object_Size_Clause (U_Ent);
1496 Alignment_Check_For_Esize_Change (U_Ent);
1504 when Attribute_Output =>
1505 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1506 Set_Has_Specified_Stream_Output (Ent);
1512 when Attribute_Read =>
1513 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1514 Set_Has_Specified_Stream_Read (Ent);
1520 -- Size attribute definition clause
1522 when Attribute_Size => Size : declare
1523 Size : constant Uint := Static_Integer (Expr);
1530 if Has_Size_Clause (U_Ent) then
1531 Error_Msg_N ("size already given for &", Nam);
1533 elsif not Is_Type (U_Ent)
1534 and then Ekind (U_Ent) /= E_Variable
1535 and then Ekind (U_Ent) /= E_Constant
1537 Error_Msg_N ("size cannot be given for &", Nam);
1539 elsif Is_Array_Type (U_Ent)
1540 and then not Is_Constrained (U_Ent)
1543 ("size cannot be given for unconstrained array", Nam);
1545 elsif Size /= No_Uint then
1547 if VM_Target /= No_VM and then not GNAT_Mode then
1549 -- Size clause is not handled properly on VM targets.
1550 -- Display a warning unless we are in GNAT mode, in which
1551 -- case this is useless.
1554 ("?size clauses are ignored in this configuration", N);
1557 if Is_Type (U_Ent) then
1560 Etyp := Etype (U_Ent);
1563 -- Check size, note that Gigi is in charge of checking that the
1564 -- size of an array or record type is OK. Also we do not check
1565 -- the size in the ordinary fixed-point case, since it is too
1566 -- early to do so (there may be subsequent small clause that
1567 -- affects the size). We can check the size if a small clause
1568 -- has already been given.
1570 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1571 or else Has_Small_Clause (U_Ent)
1573 Check_Size (Expr, Etyp, Size, Biased);
1574 Set_Biased (U_Ent, N, "size clause", Biased);
1577 -- For types set RM_Size and Esize if possible
1579 if Is_Type (U_Ent) then
1580 Set_RM_Size (U_Ent, Size);
1582 -- For scalar types, increase Object_Size to power of 2, but
1583 -- not less than a storage unit in any case (i.e., normally
1584 -- this means it will be byte addressable).
1586 if Is_Scalar_Type (U_Ent) then
1587 if Size <= System_Storage_Unit then
1588 Init_Esize (U_Ent, System_Storage_Unit);
1589 elsif Size <= 16 then
1590 Init_Esize (U_Ent, 16);
1591 elsif Size <= 32 then
1592 Init_Esize (U_Ent, 32);
1594 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1597 -- For all other types, object size = value size. The
1598 -- backend will adjust as needed.
1601 Set_Esize (U_Ent, Size);
1604 Alignment_Check_For_Esize_Change (U_Ent);
1606 -- For objects, set Esize only
1609 if Is_Elementary_Type (Etyp) then
1610 if Size /= System_Storage_Unit
1612 Size /= System_Storage_Unit * 2
1614 Size /= System_Storage_Unit * 4
1616 Size /= System_Storage_Unit * 8
1618 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1619 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1621 ("size for primitive object must be a power of 2"
1622 & " in the range ^-^", N);
1626 Set_Esize (U_Ent, Size);
1629 Set_Has_Size_Clause (U_Ent);
1637 -- Small attribute definition clause
1639 when Attribute_Small => Small : declare
1640 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1644 Analyze_And_Resolve (Expr, Any_Real);
1646 if Etype (Expr) = Any_Type then
1649 elsif not Is_Static_Expression (Expr) then
1650 Flag_Non_Static_Expr
1651 ("small requires static expression!", Expr);
1655 Small := Expr_Value_R (Expr);
1657 if Small <= Ureal_0 then
1658 Error_Msg_N ("small value must be greater than zero", Expr);
1664 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1666 ("small requires an ordinary fixed point type", Nam);
1668 elsif Has_Small_Clause (U_Ent) then
1669 Error_Msg_N ("small already given for &", Nam);
1671 elsif Small > Delta_Value (U_Ent) then
1673 ("small value must not be greater then delta value", Nam);
1676 Set_Small_Value (U_Ent, Small);
1677 Set_Small_Value (Implicit_Base, Small);
1678 Set_Has_Small_Clause (U_Ent);
1679 Set_Has_Small_Clause (Implicit_Base);
1680 Set_Has_Non_Standard_Rep (Implicit_Base);
1688 -- Storage_Pool attribute definition clause
1690 when Attribute_Storage_Pool => Storage_Pool : declare
1695 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1697 ("storage pool cannot be given for access-to-subprogram type",
1702 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
1705 ("storage pool can only be given for access types", Nam);
1708 elsif Is_Derived_Type (U_Ent) then
1710 ("storage pool cannot be given for a derived access type",
1713 elsif Has_Storage_Size_Clause (U_Ent) then
1714 Error_Msg_N ("storage size already given for &", Nam);
1717 elsif Present (Associated_Storage_Pool (U_Ent)) then
1718 Error_Msg_N ("storage pool already given for &", Nam);
1723 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1725 if not Denotes_Variable (Expr) then
1726 Error_Msg_N ("storage pool must be a variable", Expr);
1730 if Nkind (Expr) = N_Type_Conversion then
1731 T := Etype (Expression (Expr));
1736 -- The Stack_Bounded_Pool is used internally for implementing
1737 -- access types with a Storage_Size. Since it only work
1738 -- properly when used on one specific type, we need to check
1739 -- that it is not hijacked improperly:
1740 -- type T is access Integer;
1741 -- for T'Storage_Size use n;
1742 -- type Q is access Float;
1743 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1745 if RTE_Available (RE_Stack_Bounded_Pool)
1746 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1748 Error_Msg_N ("non-shareable internal Pool", Expr);
1752 -- If the argument is a name that is not an entity name, then
1753 -- we construct a renaming operation to define an entity of
1754 -- type storage pool.
1756 if not Is_Entity_Name (Expr)
1757 and then Is_Object_Reference (Expr)
1759 Pool := Make_Temporary (Loc, 'P', Expr);
1762 Rnode : constant Node_Id :=
1763 Make_Object_Renaming_Declaration (Loc,
1764 Defining_Identifier => Pool,
1766 New_Occurrence_Of (Etype (Expr), Loc),
1770 Insert_Before (N, Rnode);
1772 Set_Associated_Storage_Pool (U_Ent, Pool);
1775 elsif Is_Entity_Name (Expr) then
1776 Pool := Entity (Expr);
1778 -- If pool is a renamed object, get original one. This can
1779 -- happen with an explicit renaming, and within instances.
1781 while Present (Renamed_Object (Pool))
1782 and then Is_Entity_Name (Renamed_Object (Pool))
1784 Pool := Entity (Renamed_Object (Pool));
1787 if Present (Renamed_Object (Pool))
1788 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1789 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1791 Pool := Entity (Expression (Renamed_Object (Pool)));
1794 Set_Associated_Storage_Pool (U_Ent, Pool);
1796 elsif Nkind (Expr) = N_Type_Conversion
1797 and then Is_Entity_Name (Expression (Expr))
1798 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1800 Pool := Entity (Expression (Expr));
1801 Set_Associated_Storage_Pool (U_Ent, Pool);
1804 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1813 -- Storage_Size attribute definition clause
1815 when Attribute_Storage_Size => Storage_Size : declare
1816 Btype : constant Entity_Id := Base_Type (U_Ent);
1820 if Is_Task_Type (U_Ent) then
1821 Check_Restriction (No_Obsolescent_Features, N);
1823 if Warn_On_Obsolescent_Feature then
1825 ("storage size clause for task is an " &
1826 "obsolescent feature (RM J.9)?", N);
1827 Error_Msg_N ("\use Storage_Size pragma instead?", N);
1833 if not Is_Access_Type (U_Ent)
1834 and then Ekind (U_Ent) /= E_Task_Type
1836 Error_Msg_N ("storage size cannot be given for &", Nam);
1838 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1840 ("storage size cannot be given for a derived access type",
1843 elsif Has_Storage_Size_Clause (Btype) then
1844 Error_Msg_N ("storage size already given for &", Nam);
1847 Analyze_And_Resolve (Expr, Any_Integer);
1849 if Is_Access_Type (U_Ent) then
1850 if Present (Associated_Storage_Pool (U_Ent)) then
1851 Error_Msg_N ("storage pool already given for &", Nam);
1855 if Is_OK_Static_Expression (Expr)
1856 and then Expr_Value (Expr) = 0
1858 Set_No_Pool_Assigned (Btype);
1861 else -- Is_Task_Type (U_Ent)
1862 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1864 if Present (Sprag) then
1865 Error_Msg_Sloc := Sloc (Sprag);
1867 ("Storage_Size already specified#", Nam);
1872 Set_Has_Storage_Size_Clause (Btype);
1880 when Attribute_Stream_Size => Stream_Size : declare
1881 Size : constant Uint := Static_Integer (Expr);
1884 if Ada_Version <= Ada_95 then
1885 Check_Restriction (No_Implementation_Attributes, N);
1888 if Has_Stream_Size_Clause (U_Ent) then
1889 Error_Msg_N ("Stream_Size already given for &", Nam);
1891 elsif Is_Elementary_Type (U_Ent) then
1892 if Size /= System_Storage_Unit
1894 Size /= System_Storage_Unit * 2
1896 Size /= System_Storage_Unit * 4
1898 Size /= System_Storage_Unit * 8
1900 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1902 ("stream size for elementary type must be a"
1903 & " power of 2 and at least ^", N);
1905 elsif RM_Size (U_Ent) > Size then
1906 Error_Msg_Uint_1 := RM_Size (U_Ent);
1908 ("stream size for elementary type must be a"
1909 & " power of 2 and at least ^", N);
1912 Set_Has_Stream_Size_Clause (U_Ent);
1915 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1923 -- Value_Size attribute definition clause
1925 when Attribute_Value_Size => Value_Size : declare
1926 Size : constant Uint := Static_Integer (Expr);
1930 if not Is_Type (U_Ent) then
1931 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1934 (Get_Attribute_Definition_Clause
1935 (U_Ent, Attribute_Value_Size))
1937 Error_Msg_N ("Value_Size already given for &", Nam);
1939 elsif Is_Array_Type (U_Ent)
1940 and then not Is_Constrained (U_Ent)
1943 ("Value_Size cannot be given for unconstrained array", Nam);
1946 if Is_Elementary_Type (U_Ent) then
1947 Check_Size (Expr, U_Ent, Size, Biased);
1948 Set_Biased (U_Ent, N, "value size clause", Biased);
1951 Set_RM_Size (U_Ent, Size);
1959 when Attribute_Write =>
1960 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1961 Set_Has_Specified_Stream_Write (Ent);
1963 -- All other attributes cannot be set
1967 ("attribute& cannot be set with definition clause", N);
1970 -- The test for the type being frozen must be performed after
1971 -- any expression the clause has been analyzed since the expression
1972 -- itself might cause freezing that makes the clause illegal.
1974 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1977 end Analyze_Attribute_Definition_Clause;
1979 ----------------------------
1980 -- Analyze_Code_Statement --
1981 ----------------------------
1983 procedure Analyze_Code_Statement (N : Node_Id) is
1984 HSS : constant Node_Id := Parent (N);
1985 SBody : constant Node_Id := Parent (HSS);
1986 Subp : constant Entity_Id := Current_Scope;
1993 -- Analyze and check we get right type, note that this implements the
1994 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1995 -- is the only way that Asm_Insn could possibly be visible.
1997 Analyze_And_Resolve (Expression (N));
1999 if Etype (Expression (N)) = Any_Type then
2001 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
2002 Error_Msg_N ("incorrect type for code statement", N);
2006 Check_Code_Statement (N);
2008 -- Make sure we appear in the handled statement sequence of a
2009 -- subprogram (RM 13.8(3)).
2011 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2012 or else Nkind (SBody) /= N_Subprogram_Body
2015 ("code statement can only appear in body of subprogram", N);
2019 -- Do remaining checks (RM 13.8(3)) if not already done
2021 if not Is_Machine_Code_Subprogram (Subp) then
2022 Set_Is_Machine_Code_Subprogram (Subp);
2024 -- No exception handlers allowed
2026 if Present (Exception_Handlers (HSS)) then
2028 ("exception handlers not permitted in machine code subprogram",
2029 First (Exception_Handlers (HSS)));
2032 -- No declarations other than use clauses and pragmas (we allow
2033 -- certain internally generated declarations as well).
2035 Decl := First (Declarations (SBody));
2036 while Present (Decl) loop
2037 DeclO := Original_Node (Decl);
2038 if Comes_From_Source (DeclO)
2039 and not Nkind_In (DeclO, N_Pragma,
2040 N_Use_Package_Clause,
2042 N_Implicit_Label_Declaration)
2045 ("this declaration not allowed in machine code subprogram",
2052 -- No statements other than code statements, pragmas, and labels.
2053 -- Again we allow certain internally generated statements.
2055 Stmt := First (Statements (HSS));
2056 while Present (Stmt) loop
2057 StmtO := Original_Node (Stmt);
2058 if Comes_From_Source (StmtO)
2059 and then not Nkind_In (StmtO, N_Pragma,
2064 ("this statement is not allowed in machine code subprogram",
2071 end Analyze_Code_Statement;
2073 -----------------------------------------------
2074 -- Analyze_Enumeration_Representation_Clause --
2075 -----------------------------------------------
2077 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2078 Ident : constant Node_Id := Identifier (N);
2079 Aggr : constant Node_Id := Array_Aggregate (N);
2080 Enumtype : Entity_Id;
2086 Err : Boolean := False;
2088 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2089 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2090 -- Allowed range of universal integer (= allowed range of enum lit vals)
2094 -- Minimum and maximum values of entries
2097 -- Pointer to node for literal providing max value
2100 if Ignore_Rep_Clauses then
2104 -- First some basic error checks
2107 Enumtype := Entity (Ident);
2109 if Enumtype = Any_Type
2110 or else Rep_Item_Too_Early (Enumtype, N)
2114 Enumtype := Underlying_Type (Enumtype);
2117 if not Is_Enumeration_Type (Enumtype) then
2119 ("enumeration type required, found}",
2120 Ident, First_Subtype (Enumtype));
2124 -- Ignore rep clause on generic actual type. This will already have
2125 -- been flagged on the template as an error, and this is the safest
2126 -- way to ensure we don't get a junk cascaded message in the instance.
2128 if Is_Generic_Actual_Type (Enumtype) then
2131 -- Type must be in current scope
2133 elsif Scope (Enumtype) /= Current_Scope then
2134 Error_Msg_N ("type must be declared in this scope", Ident);
2137 -- Type must be a first subtype
2139 elsif not Is_First_Subtype (Enumtype) then
2140 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2143 -- Ignore duplicate rep clause
2145 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2146 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2149 -- Don't allow rep clause for standard [wide_[wide_]]character
2151 elsif Is_Standard_Character_Type (Enumtype) then
2152 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2155 -- Check that the expression is a proper aggregate (no parentheses)
2157 elsif Paren_Count (Aggr) /= 0 then
2159 ("extra parentheses surrounding aggregate not allowed",
2163 -- All tests passed, so set rep clause in place
2166 Set_Has_Enumeration_Rep_Clause (Enumtype);
2167 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2170 -- Now we process the aggregate. Note that we don't use the normal
2171 -- aggregate code for this purpose, because we don't want any of the
2172 -- normal expansion activities, and a number of special semantic
2173 -- rules apply (including the component type being any integer type)
2175 Elit := First_Literal (Enumtype);
2177 -- First the positional entries if any
2179 if Present (Expressions (Aggr)) then
2180 Expr := First (Expressions (Aggr));
2181 while Present (Expr) loop
2183 Error_Msg_N ("too many entries in aggregate", Expr);
2187 Val := Static_Integer (Expr);
2189 -- Err signals that we found some incorrect entries processing
2190 -- the list. The final checks for completeness and ordering are
2191 -- skipped in this case.
2193 if Val = No_Uint then
2195 elsif Val < Lo or else Hi < Val then
2196 Error_Msg_N ("value outside permitted range", Expr);
2200 Set_Enumeration_Rep (Elit, Val);
2201 Set_Enumeration_Rep_Expr (Elit, Expr);
2207 -- Now process the named entries if present
2209 if Present (Component_Associations (Aggr)) then
2210 Assoc := First (Component_Associations (Aggr));
2211 while Present (Assoc) loop
2212 Choice := First (Choices (Assoc));
2214 if Present (Next (Choice)) then
2216 ("multiple choice not allowed here", Next (Choice));
2220 if Nkind (Choice) = N_Others_Choice then
2221 Error_Msg_N ("others choice not allowed here", Choice);
2224 elsif Nkind (Choice) = N_Range then
2225 -- ??? should allow zero/one element range here
2226 Error_Msg_N ("range not allowed here", Choice);
2230 Analyze_And_Resolve (Choice, Enumtype);
2232 if Is_Entity_Name (Choice)
2233 and then Is_Type (Entity (Choice))
2235 Error_Msg_N ("subtype name not allowed here", Choice);
2237 -- ??? should allow static subtype with zero/one entry
2239 elsif Etype (Choice) = Base_Type (Enumtype) then
2240 if not Is_Static_Expression (Choice) then
2241 Flag_Non_Static_Expr
2242 ("non-static expression used for choice!", Choice);
2246 Elit := Expr_Value_E (Choice);
2248 if Present (Enumeration_Rep_Expr (Elit)) then
2249 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2251 ("representation for& previously given#",
2256 Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
2258 Expr := Expression (Assoc);
2259 Val := Static_Integer (Expr);
2261 if Val = No_Uint then
2264 elsif Val < Lo or else Hi < Val then
2265 Error_Msg_N ("value outside permitted range", Expr);
2269 Set_Enumeration_Rep (Elit, Val);
2278 -- Aggregate is fully processed. Now we check that a full set of
2279 -- representations was given, and that they are in range and in order.
2280 -- These checks are only done if no other errors occurred.
2286 Elit := First_Literal (Enumtype);
2287 while Present (Elit) loop
2288 if No (Enumeration_Rep_Expr (Elit)) then
2289 Error_Msg_NE ("missing representation for&!", N, Elit);
2292 Val := Enumeration_Rep (Elit);
2294 if Min = No_Uint then
2298 if Val /= No_Uint then
2299 if Max /= No_Uint and then Val <= Max then
2301 ("enumeration value for& not ordered!",
2302 Enumeration_Rep_Expr (Elit), Elit);
2305 Max_Node := Enumeration_Rep_Expr (Elit);
2309 -- If there is at least one literal whose representation is not
2310 -- equal to the Pos value, then note that this enumeration type
2311 -- has a non-standard representation.
2313 if Val /= Enumeration_Pos (Elit) then
2314 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2321 -- Now set proper size information
2324 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2327 if Has_Size_Clause (Enumtype) then
2329 -- All OK, if size is OK now
2331 if RM_Size (Enumtype) >= Minsize then
2335 -- Try if we can get by with biasing
2338 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2340 -- Error message if even biasing does not work
2342 if RM_Size (Enumtype) < Minsize then
2343 Error_Msg_Uint_1 := RM_Size (Enumtype);
2344 Error_Msg_Uint_2 := Max;
2346 ("previously given size (^) is too small "
2347 & "for this value (^)", Max_Node);
2349 -- If biasing worked, indicate that we now have biased rep
2353 (Enumtype, Size_Clause (Enumtype), "size clause");
2358 Set_RM_Size (Enumtype, Minsize);
2359 Set_Enum_Esize (Enumtype);
2362 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2363 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2364 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2368 -- We repeat the too late test in case it froze itself!
2370 if Rep_Item_Too_Late (Enumtype, N) then
2373 end Analyze_Enumeration_Representation_Clause;
2375 ----------------------------
2376 -- Analyze_Free_Statement --
2377 ----------------------------
2379 procedure Analyze_Free_Statement (N : Node_Id) is
2381 Analyze (Expression (N));
2382 end Analyze_Free_Statement;
2384 ---------------------------
2385 -- Analyze_Freeze_Entity --
2386 ---------------------------
2388 procedure Analyze_Freeze_Entity (N : Node_Id) is
2389 E : constant Entity_Id := Entity (N);
2392 -- Remember that we are processing a freezing entity. Required to
2393 -- ensure correct decoration of internal entities associated with
2394 -- interfaces (see New_Overloaded_Entity).
2396 Inside_Freezing_Actions := Inside_Freezing_Actions + 1;
2398 -- For tagged types covering interfaces add internal entities that link
2399 -- the primitives of the interfaces with the primitives that cover them.
2400 -- Note: These entities were originally generated only when generating
2401 -- code because their main purpose was to provide support to initialize
2402 -- the secondary dispatch tables. They are now generated also when
2403 -- compiling with no code generation to provide ASIS the relationship
2404 -- between interface primitives and tagged type primitives. They are
2405 -- also used to locate primitives covering interfaces when processing
2406 -- generics (see Derive_Subprograms).
2408 if Ada_Version >= Ada_05
2409 and then Ekind (E) = E_Record_Type
2410 and then Is_Tagged_Type (E)
2411 and then not Is_Interface (E)
2412 and then Has_Interfaces (E)
2414 -- This would be a good common place to call the routine that checks
2415 -- overriding of interface primitives (and thus factorize calls to
2416 -- Check_Abstract_Overriding located at different contexts in the
2417 -- compiler). However, this is not possible because it causes
2418 -- spurious errors in case of late overriding.
2420 Add_Internal_Interface_Entities (E);
2425 if Ekind (E) = E_Record_Type
2426 and then Is_CPP_Class (E)
2427 and then Is_Tagged_Type (E)
2428 and then Tagged_Type_Expansion
2429 and then Expander_Active
2431 if CPP_Num_Prims (E) = 0 then
2433 -- If the CPP type has user defined components then it must import
2434 -- primitives from C++. This is required because if the C++ class
2435 -- has no primitives then the C++ compiler does not added the _tag
2436 -- component to the type.
2438 pragma Assert (Chars (First_Entity (E)) = Name_uTag);
2440 if First_Entity (E) /= Last_Entity (E) then
2442 ("?'C'P'P type must import at least one primitive from C++",
2447 -- Check that all its primitives are abstract or imported from C++.
2448 -- Check also availability of the C++ constructor.
2451 Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
2453 Error_Reported : Boolean := False;
2457 Elmt := First_Elmt (Primitive_Operations (E));
2458 while Present (Elmt) loop
2459 Prim := Node (Elmt);
2461 if Comes_From_Source (Prim) then
2462 if Is_Abstract_Subprogram (Prim) then
2465 elsif not Is_Imported (Prim)
2466 or else Convention (Prim) /= Convention_CPP
2469 ("?primitives of 'C'P'P types must be imported from C++"
2470 & " or abstract", Prim);
2472 elsif not Has_Constructors
2473 and then not Error_Reported
2475 Error_Msg_Name_1 := Chars (E);
2477 ("?'C'P'P constructor required for type %", Prim);
2478 Error_Reported := True;
2487 Inside_Freezing_Actions := Inside_Freezing_Actions - 1;
2488 end Analyze_Freeze_Entity;
2490 ------------------------------------------
2491 -- Analyze_Record_Representation_Clause --
2492 ------------------------------------------
2494 -- Note: we check as much as we can here, but we can't do any checks
2495 -- based on the position values (e.g. overlap checks) until freeze time
2496 -- because especially in Ada 2005 (machine scalar mode), the processing
2497 -- for non-standard bit order can substantially change the positions.
2498 -- See procedure Check_Record_Representation_Clause (called from Freeze)
2499 -- for the remainder of this processing.
2501 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2502 Ident : constant Node_Id := Identifier (N);
2507 Hbit : Uint := Uint_0;
2511 Rectype : Entity_Id;
2513 CR_Pragma : Node_Id := Empty;
2514 -- Points to N_Pragma node if Complete_Representation pragma present
2517 if Ignore_Rep_Clauses then
2522 Rectype := Entity (Ident);
2524 if Rectype = Any_Type
2525 or else Rep_Item_Too_Early (Rectype, N)
2529 Rectype := Underlying_Type (Rectype);
2532 -- First some basic error checks
2534 if not Is_Record_Type (Rectype) then
2536 ("record type required, found}", Ident, First_Subtype (Rectype));
2539 elsif Scope (Rectype) /= Current_Scope then
2540 Error_Msg_N ("type must be declared in this scope", N);
2543 elsif not Is_First_Subtype (Rectype) then
2544 Error_Msg_N ("cannot give record rep clause for subtype", N);
2547 elsif Has_Record_Rep_Clause (Rectype) then
2548 Error_Msg_N ("duplicate record rep clause ignored", N);
2551 elsif Rep_Item_Too_Late (Rectype, N) then
2555 if Present (Mod_Clause (N)) then
2557 Loc : constant Source_Ptr := Sloc (N);
2558 M : constant Node_Id := Mod_Clause (N);
2559 P : constant List_Id := Pragmas_Before (M);
2563 pragma Warnings (Off, Mod_Val);
2566 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2568 if Warn_On_Obsolescent_Feature then
2570 ("mod clause is an obsolescent feature (RM J.8)?", N);
2572 ("\use alignment attribute definition clause instead?", N);
2579 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2580 -- the Mod clause into an alignment clause anyway, so that the
2581 -- back-end can compute and back-annotate properly the size and
2582 -- alignment of types that may include this record.
2584 -- This seems dubious, this destroys the source tree in a manner
2585 -- not detectable by ASIS ???
2587 if Operating_Mode = Check_Semantics
2591 Make_Attribute_Definition_Clause (Loc,
2592 Name => New_Reference_To (Base_Type (Rectype), Loc),
2593 Chars => Name_Alignment,
2594 Expression => Relocate_Node (Expression (M)));
2596 Set_From_At_Mod (AtM_Nod);
2597 Insert_After (N, AtM_Nod);
2598 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2599 Set_Mod_Clause (N, Empty);
2602 -- Get the alignment value to perform error checking
2604 Mod_Val := Get_Alignment_Value (Expression (M));
2609 -- For untagged types, clear any existing component clauses for the
2610 -- type. If the type is derived, this is what allows us to override
2611 -- a rep clause for the parent. For type extensions, the representation
2612 -- of the inherited components is inherited, so we want to keep previous
2613 -- component clauses for completeness.
2615 if not Is_Tagged_Type (Rectype) then
2616 Comp := First_Component_Or_Discriminant (Rectype);
2617 while Present (Comp) loop
2618 Set_Component_Clause (Comp, Empty);
2619 Next_Component_Or_Discriminant (Comp);
2623 -- All done if no component clauses
2625 CC := First (Component_Clauses (N));
2631 -- A representation like this applies to the base type
2633 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2634 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2635 Set_Has_Specified_Layout (Base_Type (Rectype));
2637 -- Process the component clauses
2639 while Present (CC) loop
2643 if Nkind (CC) = N_Pragma then
2646 -- The only pragma of interest is Complete_Representation
2648 if Pragma_Name (CC) = Name_Complete_Representation then
2652 -- Processing for real component clause
2655 Posit := Static_Integer (Position (CC));
2656 Fbit := Static_Integer (First_Bit (CC));
2657 Lbit := Static_Integer (Last_Bit (CC));
2660 and then Fbit /= No_Uint
2661 and then Lbit /= No_Uint
2665 ("position cannot be negative", Position (CC));
2669 ("first bit cannot be negative", First_Bit (CC));
2671 -- The Last_Bit specified in a component clause must not be
2672 -- less than the First_Bit minus one (RM-13.5.1(10)).
2674 elsif Lbit < Fbit - 1 then
2676 ("last bit cannot be less than first bit minus one",
2679 -- Values look OK, so find the corresponding record component
2680 -- Even though the syntax allows an attribute reference for
2681 -- implementation-defined components, GNAT does not allow the
2682 -- tag to get an explicit position.
2684 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2685 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2686 Error_Msg_N ("position of tag cannot be specified", CC);
2688 Error_Msg_N ("illegal component name", CC);
2692 Comp := First_Entity (Rectype);
2693 while Present (Comp) loop
2694 exit when Chars (Comp) = Chars (Component_Name (CC));
2700 -- Maybe component of base type that is absent from
2701 -- statically constrained first subtype.
2703 Comp := First_Entity (Base_Type (Rectype));
2704 while Present (Comp) loop
2705 exit when Chars (Comp) = Chars (Component_Name (CC));
2712 ("component clause is for non-existent field", CC);
2714 -- Ada 2012 (AI05-0026): Any name that denotes a
2715 -- discriminant of an object of an unchecked union type
2716 -- shall not occur within a record_representation_clause.
2718 -- The general restriction of using record rep clauses on
2719 -- Unchecked_Union types has now been lifted. Since it is
2720 -- possible to introduce a record rep clause which mentions
2721 -- the discriminant of an Unchecked_Union in non-Ada 2012
2722 -- code, this check is applied to all versions of the
2725 elsif Ekind (Comp) = E_Discriminant
2726 and then Is_Unchecked_Union (Rectype)
2729 ("cannot reference discriminant of Unchecked_Union",
2730 Component_Name (CC));
2732 elsif Present (Component_Clause (Comp)) then
2734 -- Diagnose duplicate rep clause, or check consistency
2735 -- if this is an inherited component. In a double fault,
2736 -- there may be a duplicate inconsistent clause for an
2737 -- inherited component.
2739 if Scope (Original_Record_Component (Comp)) = Rectype
2740 or else Parent (Component_Clause (Comp)) = N
2742 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2743 Error_Msg_N ("component clause previously given#", CC);
2747 Rep1 : constant Node_Id := Component_Clause (Comp);
2749 if Intval (Position (Rep1)) /=
2750 Intval (Position (CC))
2751 or else Intval (First_Bit (Rep1)) /=
2752 Intval (First_Bit (CC))
2753 or else Intval (Last_Bit (Rep1)) /=
2754 Intval (Last_Bit (CC))
2756 Error_Msg_N ("component clause inconsistent "
2757 & "with representation of ancestor", CC);
2758 elsif Warn_On_Redundant_Constructs then
2759 Error_Msg_N ("?redundant component clause "
2760 & "for inherited component!", CC);
2765 -- Normal case where this is the first component clause we
2766 -- have seen for this entity, so set it up properly.
2769 -- Make reference for field in record rep clause and set
2770 -- appropriate entity field in the field identifier.
2773 (Comp, Component_Name (CC), Set_Ref => False);
2774 Set_Entity (Component_Name (CC), Comp);
2776 -- Update Fbit and Lbit to the actual bit number
2778 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2779 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2781 if Has_Size_Clause (Rectype)
2782 and then Esize (Rectype) <= Lbit
2785 ("bit number out of range of specified size",
2788 Set_Component_Clause (Comp, CC);
2789 Set_Component_Bit_Offset (Comp, Fbit);
2790 Set_Esize (Comp, 1 + (Lbit - Fbit));
2791 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2792 Set_Normalized_Position (Comp, Fbit / SSU);
2794 if Warn_On_Overridden_Size
2795 and then Has_Size_Clause (Etype (Comp))
2796 and then RM_Size (Etype (Comp)) /= Esize (Comp)
2799 ("?component size overrides size clause for&",
2800 Component_Name (CC), Etype (Comp));
2803 -- This information is also set in the corresponding
2804 -- component of the base type, found by accessing the
2805 -- Original_Record_Component link if it is present.
2807 Ocomp := Original_Record_Component (Comp);
2814 (Component_Name (CC),
2820 (Comp, First_Node (CC), "component clause", Biased);
2822 if Present (Ocomp) then
2823 Set_Component_Clause (Ocomp, CC);
2824 Set_Component_Bit_Offset (Ocomp, Fbit);
2825 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2826 Set_Normalized_Position (Ocomp, Fbit / SSU);
2827 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2829 Set_Normalized_Position_Max
2830 (Ocomp, Normalized_Position (Ocomp));
2832 -- Note: we don't use Set_Biased here, because we
2833 -- already gave a warning above if needed, and we
2834 -- would get a duplicate for the same name here.
2836 Set_Has_Biased_Representation
2837 (Ocomp, Has_Biased_Representation (Comp));
2840 if Esize (Comp) < 0 then
2841 Error_Msg_N ("component size is negative", CC);
2852 -- Check missing components if Complete_Representation pragma appeared
2854 if Present (CR_Pragma) then
2855 Comp := First_Component_Or_Discriminant (Rectype);
2856 while Present (Comp) loop
2857 if No (Component_Clause (Comp)) then
2859 ("missing component clause for &", CR_Pragma, Comp);
2862 Next_Component_Or_Discriminant (Comp);
2865 -- If no Complete_Representation pragma, warn if missing components
2867 elsif Warn_On_Unrepped_Components then
2869 Num_Repped_Components : Nat := 0;
2870 Num_Unrepped_Components : Nat := 0;
2873 -- First count number of repped and unrepped components
2875 Comp := First_Component_Or_Discriminant (Rectype);
2876 while Present (Comp) loop
2877 if Present (Component_Clause (Comp)) then
2878 Num_Repped_Components := Num_Repped_Components + 1;
2880 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2883 Next_Component_Or_Discriminant (Comp);
2886 -- We are only interested in the case where there is at least one
2887 -- unrepped component, and at least half the components have rep
2888 -- clauses. We figure that if less than half have them, then the
2889 -- partial rep clause is really intentional. If the component
2890 -- type has no underlying type set at this point (as for a generic
2891 -- formal type), we don't know enough to give a warning on the
2894 if Num_Unrepped_Components > 0
2895 and then Num_Unrepped_Components < Num_Repped_Components
2897 Comp := First_Component_Or_Discriminant (Rectype);
2898 while Present (Comp) loop
2899 if No (Component_Clause (Comp))
2900 and then Comes_From_Source (Comp)
2901 and then Present (Underlying_Type (Etype (Comp)))
2902 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2903 or else Size_Known_At_Compile_Time
2904 (Underlying_Type (Etype (Comp))))
2905 and then not Has_Warnings_Off (Rectype)
2907 Error_Msg_Sloc := Sloc (Comp);
2909 ("?no component clause given for & declared #",
2913 Next_Component_Or_Discriminant (Comp);
2918 end Analyze_Record_Representation_Clause;
2920 -----------------------------------
2921 -- Check_Constant_Address_Clause --
2922 -----------------------------------
2924 procedure Check_Constant_Address_Clause
2928 procedure Check_At_Constant_Address (Nod : Node_Id);
2929 -- Checks that the given node N represents a name whose 'Address is
2930 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2931 -- address value is the same at the point of declaration of U_Ent and at
2932 -- the time of elaboration of the address clause.
2934 procedure Check_Expr_Constants (Nod : Node_Id);
2935 -- Checks that Nod meets the requirements for a constant address clause
2936 -- in the sense of the enclosing procedure.
2938 procedure Check_List_Constants (Lst : List_Id);
2939 -- Check that all elements of list Lst meet the requirements for a
2940 -- constant address clause in the sense of the enclosing procedure.
2942 -------------------------------
2943 -- Check_At_Constant_Address --
2944 -------------------------------
2946 procedure Check_At_Constant_Address (Nod : Node_Id) is
2948 if Is_Entity_Name (Nod) then
2949 if Present (Address_Clause (Entity ((Nod)))) then
2951 ("invalid address clause for initialized object &!",
2954 ("address for& cannot" &
2955 " depend on another address clause! (RM 13.1(22))!",
2958 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2959 and then Sloc (U_Ent) < Sloc (Entity (Nod))
2962 ("invalid address clause for initialized object &!",
2964 Error_Msg_Node_2 := U_Ent;
2966 ("\& must be defined before & (RM 13.1(22))!",
2970 elsif Nkind (Nod) = N_Selected_Component then
2972 T : constant Entity_Id := Etype (Prefix (Nod));
2975 if (Is_Record_Type (T)
2976 and then Has_Discriminants (T))
2979 and then Is_Record_Type (Designated_Type (T))
2980 and then Has_Discriminants (Designated_Type (T)))
2983 ("invalid address clause for initialized object &!",
2986 ("\address cannot depend on component" &
2987 " of discriminated record (RM 13.1(22))!",
2990 Check_At_Constant_Address (Prefix (Nod));
2994 elsif Nkind (Nod) = N_Indexed_Component then
2995 Check_At_Constant_Address (Prefix (Nod));
2996 Check_List_Constants (Expressions (Nod));
2999 Check_Expr_Constants (Nod);
3001 end Check_At_Constant_Address;
3003 --------------------------
3004 -- Check_Expr_Constants --
3005 --------------------------
3007 procedure Check_Expr_Constants (Nod : Node_Id) is
3008 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
3009 Ent : Entity_Id := Empty;
3012 if Nkind (Nod) in N_Has_Etype
3013 and then Etype (Nod) = Any_Type
3019 when N_Empty | N_Error =>
3022 when N_Identifier | N_Expanded_Name =>
3023 Ent := Entity (Nod);
3025 -- We need to look at the original node if it is different
3026 -- from the node, since we may have rewritten things and
3027 -- substituted an identifier representing the rewrite.
3029 if Original_Node (Nod) /= Nod then
3030 Check_Expr_Constants (Original_Node (Nod));
3032 -- If the node is an object declaration without initial
3033 -- value, some code has been expanded, and the expression
3034 -- is not constant, even if the constituents might be
3035 -- acceptable, as in A'Address + offset.
3037 if Ekind (Ent) = E_Variable
3039 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3041 No (Expression (Declaration_Node (Ent)))
3044 ("invalid address clause for initialized object &!",
3047 -- If entity is constant, it may be the result of expanding
3048 -- a check. We must verify that its declaration appears
3049 -- before the object in question, else we also reject the
3052 elsif Ekind (Ent) = E_Constant
3053 and then In_Same_Source_Unit (Ent, U_Ent)
3054 and then Sloc (Ent) > Loc_U_Ent
3057 ("invalid address clause for initialized object &!",
3064 -- Otherwise look at the identifier and see if it is OK
3066 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
3067 or else Is_Type (Ent)
3072 Ekind (Ent) = E_Constant
3074 Ekind (Ent) = E_In_Parameter
3076 -- This is the case where we must have Ent defined before
3077 -- U_Ent. Clearly if they are in different units this
3078 -- requirement is met since the unit containing Ent is
3079 -- already processed.
3081 if not In_Same_Source_Unit (Ent, U_Ent) then
3084 -- Otherwise location of Ent must be before the location
3085 -- of U_Ent, that's what prior defined means.
3087 elsif Sloc (Ent) < Loc_U_Ent then
3092 ("invalid address clause for initialized object &!",
3094 Error_Msg_Node_2 := U_Ent;
3096 ("\& must be defined before & (RM 13.1(22))!",
3100 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3101 Check_Expr_Constants (Original_Node (Nod));
3105 ("invalid address clause for initialized object &!",
3108 if Comes_From_Source (Ent) then
3110 ("\reference to variable& not allowed"
3111 & " (RM 13.1(22))!", Nod, Ent);
3114 ("non-static expression not allowed"
3115 & " (RM 13.1(22))!", Nod);
3119 when N_Integer_Literal =>
3121 -- If this is a rewritten unchecked conversion, in a system
3122 -- where Address is an integer type, always use the base type
3123 -- for a literal value. This is user-friendly and prevents
3124 -- order-of-elaboration issues with instances of unchecked
3127 if Nkind (Original_Node (Nod)) = N_Function_Call then
3128 Set_Etype (Nod, Base_Type (Etype (Nod)));
3131 when N_Real_Literal |
3133 N_Character_Literal =>
3137 Check_Expr_Constants (Low_Bound (Nod));
3138 Check_Expr_Constants (High_Bound (Nod));
3140 when N_Explicit_Dereference =>
3141 Check_Expr_Constants (Prefix (Nod));
3143 when N_Indexed_Component =>
3144 Check_Expr_Constants (Prefix (Nod));
3145 Check_List_Constants (Expressions (Nod));
3148 Check_Expr_Constants (Prefix (Nod));
3149 Check_Expr_Constants (Discrete_Range (Nod));
3151 when N_Selected_Component =>
3152 Check_Expr_Constants (Prefix (Nod));
3154 when N_Attribute_Reference =>
3155 if Attribute_Name (Nod) = Name_Address
3157 Attribute_Name (Nod) = Name_Access
3159 Attribute_Name (Nod) = Name_Unchecked_Access
3161 Attribute_Name (Nod) = Name_Unrestricted_Access
3163 Check_At_Constant_Address (Prefix (Nod));
3166 Check_Expr_Constants (Prefix (Nod));
3167 Check_List_Constants (Expressions (Nod));
3171 Check_List_Constants (Component_Associations (Nod));
3172 Check_List_Constants (Expressions (Nod));
3174 when N_Component_Association =>
3175 Check_Expr_Constants (Expression (Nod));
3177 when N_Extension_Aggregate =>
3178 Check_Expr_Constants (Ancestor_Part (Nod));
3179 Check_List_Constants (Component_Associations (Nod));
3180 Check_List_Constants (Expressions (Nod));
3185 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3186 Check_Expr_Constants (Left_Opnd (Nod));
3187 Check_Expr_Constants (Right_Opnd (Nod));
3190 Check_Expr_Constants (Right_Opnd (Nod));
3192 when N_Type_Conversion |
3193 N_Qualified_Expression |
3195 Check_Expr_Constants (Expression (Nod));
3197 when N_Unchecked_Type_Conversion =>
3198 Check_Expr_Constants (Expression (Nod));
3200 -- If this is a rewritten unchecked conversion, subtypes in
3201 -- this node are those created within the instance. To avoid
3202 -- order of elaboration issues, replace them with their base
3203 -- types. Note that address clauses can cause order of
3204 -- elaboration problems because they are elaborated by the
3205 -- back-end at the point of definition, and may mention
3206 -- entities declared in between (as long as everything is
3207 -- static). It is user-friendly to allow unchecked conversions
3210 if Nkind (Original_Node (Nod)) = N_Function_Call then
3211 Set_Etype (Expression (Nod),
3212 Base_Type (Etype (Expression (Nod))));
3213 Set_Etype (Nod, Base_Type (Etype (Nod)));
3216 when N_Function_Call =>
3217 if not Is_Pure (Entity (Name (Nod))) then
3219 ("invalid address clause for initialized object &!",
3223 ("\function & is not pure (RM 13.1(22))!",
3224 Nod, Entity (Name (Nod)));
3227 Check_List_Constants (Parameter_Associations (Nod));
3230 when N_Parameter_Association =>
3231 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3235 ("invalid address clause for initialized object &!",
3238 ("\must be constant defined before& (RM 13.1(22))!",
3241 end Check_Expr_Constants;
3243 --------------------------
3244 -- Check_List_Constants --
3245 --------------------------
3247 procedure Check_List_Constants (Lst : List_Id) is
3251 if Present (Lst) then
3252 Nod1 := First (Lst);
3253 while Present (Nod1) loop
3254 Check_Expr_Constants (Nod1);
3258 end Check_List_Constants;
3260 -- Start of processing for Check_Constant_Address_Clause
3263 -- If rep_clauses are to be ignored, no need for legality checks. In
3264 -- particular, no need to pester user about rep clauses that violate
3265 -- the rule on constant addresses, given that these clauses will be
3266 -- removed by Freeze before they reach the back end.
3268 if not Ignore_Rep_Clauses then
3269 Check_Expr_Constants (Expr);
3271 end Check_Constant_Address_Clause;
3273 ----------------------------------------
3274 -- Check_Record_Representation_Clause --
3275 ----------------------------------------
3277 procedure Check_Record_Representation_Clause (N : Node_Id) is
3278 Loc : constant Source_Ptr := Sloc (N);
3279 Ident : constant Node_Id := Identifier (N);
3280 Rectype : Entity_Id;
3285 Hbit : Uint := Uint_0;
3289 Max_Bit_So_Far : Uint;
3290 -- Records the maximum bit position so far. If all field positions
3291 -- are monotonically increasing, then we can skip the circuit for
3292 -- checking for overlap, since no overlap is possible.
3294 Tagged_Parent : Entity_Id := Empty;
3295 -- This is set in the case of a derived tagged type for which we have
3296 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
3297 -- positioned by record representation clauses). In this case we must
3298 -- check for overlap between components of this tagged type, and the
3299 -- components of its parent. Tagged_Parent will point to this parent
3300 -- type. For all other cases Tagged_Parent is left set to Empty.
3302 Parent_Last_Bit : Uint;
3303 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
3304 -- last bit position for any field in the parent type. We only need to
3305 -- check overlap for fields starting below this point.
3307 Overlap_Check_Required : Boolean;
3308 -- Used to keep track of whether or not an overlap check is required
3310 Overlap_Detected : Boolean := False;
3311 -- Set True if an overlap is detected
3313 Ccount : Natural := 0;
3314 -- Number of component clauses in record rep clause
3316 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
3317 -- Given two entities for record components or discriminants, checks
3318 -- if they have overlapping component clauses and issues errors if so.
3320 procedure Find_Component;
3321 -- Finds component entity corresponding to current component clause (in
3322 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
3323 -- start/stop bits for the field. If there is no matching component or
3324 -- if the matching component does not have a component clause, then
3325 -- that's an error and Comp is set to Empty, but no error message is
3326 -- issued, since the message was already given. Comp is also set to
3327 -- Empty if the current "component clause" is in fact a pragma.
3329 -----------------------------
3330 -- Check_Component_Overlap --
3331 -----------------------------
3333 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
3334 CC1 : constant Node_Id := Component_Clause (C1_Ent);
3335 CC2 : constant Node_Id := Component_Clause (C2_Ent);
3338 if Present (CC1) and then Present (CC2) then
3340 -- Exclude odd case where we have two tag fields in the same
3341 -- record, both at location zero. This seems a bit strange, but
3342 -- it seems to happen in some circumstances, perhaps on an error.
3344 if Chars (C1_Ent) = Name_uTag
3346 Chars (C2_Ent) = Name_uTag
3351 -- Here we check if the two fields overlap
3354 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
3355 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
3356 E1 : constant Uint := S1 + Esize (C1_Ent);
3357 E2 : constant Uint := S2 + Esize (C2_Ent);
3360 if E2 <= S1 or else E1 <= S2 then
3363 Error_Msg_Node_2 := Component_Name (CC2);
3364 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
3365 Error_Msg_Node_1 := Component_Name (CC1);
3367 ("component& overlaps & #", Component_Name (CC1));
3368 Overlap_Detected := True;
3372 end Check_Component_Overlap;
3374 --------------------
3375 -- Find_Component --
3376 --------------------
3378 procedure Find_Component is
3380 procedure Search_Component (R : Entity_Id);
3381 -- Search components of R for a match. If found, Comp is set.
3383 ----------------------
3384 -- Search_Component --
3385 ----------------------
3387 procedure Search_Component (R : Entity_Id) is
3389 Comp := First_Component_Or_Discriminant (R);
3390 while Present (Comp) loop
3392 -- Ignore error of attribute name for component name (we
3393 -- already gave an error message for this, so no need to
3396 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
3399 exit when Chars (Comp) = Chars (Component_Name (CC));
3402 Next_Component_Or_Discriminant (Comp);
3404 end Search_Component;
3406 -- Start of processing for Find_Component
3409 -- Return with Comp set to Empty if we have a pragma
3411 if Nkind (CC) = N_Pragma then
3416 -- Search current record for matching component
3418 Search_Component (Rectype);
3420 -- If not found, maybe component of base type that is absent from
3421 -- statically constrained first subtype.
3424 Search_Component (Base_Type (Rectype));
3427 -- If no component, or the component does not reference the component
3428 -- clause in question, then there was some previous error for which
3429 -- we already gave a message, so just return with Comp Empty.
3432 or else Component_Clause (Comp) /= CC
3436 -- Normal case where we have a component clause
3439 Fbit := Component_Bit_Offset (Comp);
3440 Lbit := Fbit + Esize (Comp) - 1;
3444 -- Start of processing for Check_Record_Representation_Clause
3448 Rectype := Entity (Ident);
3450 if Rectype = Any_Type then
3453 Rectype := Underlying_Type (Rectype);
3456 -- See if we have a fully repped derived tagged type
3459 PS : constant Entity_Id := Parent_Subtype (Rectype);
3462 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
3463 Tagged_Parent := PS;
3465 -- Find maximum bit of any component of the parent type
3467 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
3468 Pcomp := First_Entity (Tagged_Parent);
3469 while Present (Pcomp) loop
3470 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
3471 if Component_Bit_Offset (Pcomp) /= No_Uint
3472 and then Known_Static_Esize (Pcomp)
3477 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
3480 Next_Entity (Pcomp);
3486 -- All done if no component clauses
3488 CC := First (Component_Clauses (N));
3494 -- If a tag is present, then create a component clause that places it
3495 -- at the start of the record (otherwise gigi may place it after other
3496 -- fields that have rep clauses).
3498 Fent := First_Entity (Rectype);
3500 if Nkind (Fent) = N_Defining_Identifier
3501 and then Chars (Fent) = Name_uTag
3503 Set_Component_Bit_Offset (Fent, Uint_0);
3504 Set_Normalized_Position (Fent, Uint_0);
3505 Set_Normalized_First_Bit (Fent, Uint_0);
3506 Set_Normalized_Position_Max (Fent, Uint_0);
3507 Init_Esize (Fent, System_Address_Size);
3509 Set_Component_Clause (Fent,
3510 Make_Component_Clause (Loc,
3512 Make_Identifier (Loc,
3513 Chars => Name_uTag),
3516 Make_Integer_Literal (Loc,
3520 Make_Integer_Literal (Loc,
3524 Make_Integer_Literal (Loc,
3525 UI_From_Int (System_Address_Size))));
3527 Ccount := Ccount + 1;
3530 Max_Bit_So_Far := Uint_Minus_1;
3531 Overlap_Check_Required := False;
3533 -- Process the component clauses
3535 while Present (CC) loop
3538 if Present (Comp) then
3539 Ccount := Ccount + 1;
3541 -- We need a full overlap check if record positions non-monotonic
3543 if Fbit <= Max_Bit_So_Far then
3544 Overlap_Check_Required := True;
3547 Max_Bit_So_Far := Lbit;
3549 -- Check bit position out of range of specified size
3551 if Has_Size_Clause (Rectype)
3552 and then Esize (Rectype) <= Lbit
3555 ("bit number out of range of specified size",
3558 -- Check for overlap with tag field
3561 if Is_Tagged_Type (Rectype)
3562 and then Fbit < System_Address_Size
3565 ("component overlaps tag field of&",
3566 Component_Name (CC), Rectype);
3567 Overlap_Detected := True;
3575 -- Check parent overlap if component might overlap parent field
3577 if Present (Tagged_Parent)
3578 and then Fbit <= Parent_Last_Bit
3580 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
3581 while Present (Pcomp) loop
3582 if not Is_Tag (Pcomp)
3583 and then Chars (Pcomp) /= Name_uParent
3585 Check_Component_Overlap (Comp, Pcomp);
3588 Next_Component_Or_Discriminant (Pcomp);
3596 -- Now that we have processed all the component clauses, check for
3597 -- overlap. We have to leave this till last, since the components can
3598 -- appear in any arbitrary order in the representation clause.
3600 -- We do not need this check if all specified ranges were monotonic,
3601 -- as recorded by Overlap_Check_Required being False at this stage.
3603 -- This first section checks if there are any overlapping entries at
3604 -- all. It does this by sorting all entries and then seeing if there are
3605 -- any overlaps. If there are none, then that is decisive, but if there
3606 -- are overlaps, they may still be OK (they may result from fields in
3607 -- different variants).
3609 if Overlap_Check_Required then
3610 Overlap_Check1 : declare
3612 OC_Fbit : array (0 .. Ccount) of Uint;
3613 -- First-bit values for component clauses, the value is the offset
3614 -- of the first bit of the field from start of record. The zero
3615 -- entry is for use in sorting.
3617 OC_Lbit : array (0 .. Ccount) of Uint;
3618 -- Last-bit values for component clauses, the value is the offset
3619 -- of the last bit of the field from start of record. The zero
3620 -- entry is for use in sorting.
3622 OC_Count : Natural := 0;
3623 -- Count of entries in OC_Fbit and OC_Lbit
3625 function OC_Lt (Op1, Op2 : Natural) return Boolean;
3626 -- Compare routine for Sort
3628 procedure OC_Move (From : Natural; To : Natural);
3629 -- Move routine for Sort
3631 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
3637 function OC_Lt (Op1, Op2 : Natural) return Boolean is
3639 return OC_Fbit (Op1) < OC_Fbit (Op2);
3646 procedure OC_Move (From : Natural; To : Natural) is
3648 OC_Fbit (To) := OC_Fbit (From);
3649 OC_Lbit (To) := OC_Lbit (From);
3652 -- Start of processing for Overlap_Check
3655 CC := First (Component_Clauses (N));
3656 while Present (CC) loop
3658 -- Exclude component clause already marked in error
3660 if not Error_Posted (CC) then
3663 if Present (Comp) then
3664 OC_Count := OC_Count + 1;
3665 OC_Fbit (OC_Count) := Fbit;
3666 OC_Lbit (OC_Count) := Lbit;
3673 Sorting.Sort (OC_Count);
3675 Overlap_Check_Required := False;
3676 for J in 1 .. OC_Count - 1 loop
3677 if OC_Lbit (J) >= OC_Fbit (J + 1) then
3678 Overlap_Check_Required := True;
3685 -- If Overlap_Check_Required is still True, then we have to do the full
3686 -- scale overlap check, since we have at least two fields that do
3687 -- overlap, and we need to know if that is OK since they are in
3688 -- different variant, or whether we have a definite problem.
3690 if Overlap_Check_Required then
3691 Overlap_Check2 : declare
3692 C1_Ent, C2_Ent : Entity_Id;
3693 -- Entities of components being checked for overlap
3696 -- Component_List node whose Component_Items are being checked
3699 -- Component declaration for component being checked
3702 C1_Ent := First_Entity (Base_Type (Rectype));
3704 -- Loop through all components in record. For each component check
3705 -- for overlap with any of the preceding elements on the component
3706 -- list containing the component and also, if the component is in
3707 -- a variant, check against components outside the case structure.
3708 -- This latter test is repeated recursively up the variant tree.
3710 Main_Component_Loop : while Present (C1_Ent) loop
3711 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
3712 goto Continue_Main_Component_Loop;
3715 -- Skip overlap check if entity has no declaration node. This
3716 -- happens with discriminants in constrained derived types.
3717 -- Possibly we are missing some checks as a result, but that
3718 -- does not seem terribly serious.
3720 if No (Declaration_Node (C1_Ent)) then
3721 goto Continue_Main_Component_Loop;
3724 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
3726 -- Loop through component lists that need checking. Check the
3727 -- current component list and all lists in variants above us.
3729 Component_List_Loop : loop
3731 -- If derived type definition, go to full declaration
3732 -- If at outer level, check discriminants if there are any.
3734 if Nkind (Clist) = N_Derived_Type_Definition then
3735 Clist := Parent (Clist);
3738 -- Outer level of record definition, check discriminants
3740 if Nkind_In (Clist, N_Full_Type_Declaration,
3741 N_Private_Type_Declaration)
3743 if Has_Discriminants (Defining_Identifier (Clist)) then
3745 First_Discriminant (Defining_Identifier (Clist));
3746 while Present (C2_Ent) loop
3747 exit when C1_Ent = C2_Ent;
3748 Check_Component_Overlap (C1_Ent, C2_Ent);
3749 Next_Discriminant (C2_Ent);
3753 -- Record extension case
3755 elsif Nkind (Clist) = N_Derived_Type_Definition then
3758 -- Otherwise check one component list
3761 Citem := First (Component_Items (Clist));
3762 while Present (Citem) loop
3763 if Nkind (Citem) = N_Component_Declaration then
3764 C2_Ent := Defining_Identifier (Citem);
3765 exit when C1_Ent = C2_Ent;
3766 Check_Component_Overlap (C1_Ent, C2_Ent);
3773 -- Check for variants above us (the parent of the Clist can
3774 -- be a variant, in which case its parent is a variant part,
3775 -- and the parent of the variant part is a component list
3776 -- whose components must all be checked against the current
3777 -- component for overlap).
3779 if Nkind (Parent (Clist)) = N_Variant then
3780 Clist := Parent (Parent (Parent (Clist)));
3782 -- Check for possible discriminant part in record, this
3783 -- is treated essentially as another level in the
3784 -- recursion. For this case the parent of the component
3785 -- list is the record definition, and its parent is the
3786 -- full type declaration containing the discriminant
3789 elsif Nkind (Parent (Clist)) = N_Record_Definition then
3790 Clist := Parent (Parent ((Clist)));
3792 -- If neither of these two cases, we are at the top of
3796 exit Component_List_Loop;
3798 end loop Component_List_Loop;
3800 <<Continue_Main_Component_Loop>>
3801 Next_Entity (C1_Ent);
3803 end loop Main_Component_Loop;
3807 -- The following circuit deals with warning on record holes (gaps). We
3808 -- skip this check if overlap was detected, since it makes sense for the
3809 -- programmer to fix this illegality before worrying about warnings.
3811 if not Overlap_Detected and Warn_On_Record_Holes then
3812 Record_Hole_Check : declare
3813 Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype));
3814 -- Full declaration of record type
3816 procedure Check_Component_List
3820 -- Check component list CL for holes. The starting bit should be
3821 -- Sbit. which is zero for the main record component list and set
3822 -- appropriately for recursive calls for variants. DS is set to
3823 -- a list of discriminant specifications to be included in the
3824 -- consideration of components. It is No_List if none to consider.
3826 --------------------------
3827 -- Check_Component_List --
3828 --------------------------
3830 procedure Check_Component_List
3838 Compl := Integer (List_Length (Component_Items (CL)));
3840 if DS /= No_List then
3841 Compl := Compl + Integer (List_Length (DS));
3845 Comps : array (Natural range 0 .. Compl) of Entity_Id;
3846 -- Gather components (zero entry is for sort routine)
3848 Ncomps : Natural := 0;
3849 -- Number of entries stored in Comps (starting at Comps (1))
3852 -- One component item or discriminant specification
3855 -- Starting bit for next component
3863 function Lt (Op1, Op2 : Natural) return Boolean;
3864 -- Compare routine for Sort
3866 procedure Move (From : Natural; To : Natural);
3867 -- Move routine for Sort
3869 package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
3875 function Lt (Op1, Op2 : Natural) return Boolean is
3877 return Component_Bit_Offset (Comps (Op1))
3879 Component_Bit_Offset (Comps (Op2));
3886 procedure Move (From : Natural; To : Natural) is
3888 Comps (To) := Comps (From);
3892 -- Gather discriminants into Comp
3894 if DS /= No_List then
3895 Citem := First (DS);
3896 while Present (Citem) loop
3897 if Nkind (Citem) = N_Discriminant_Specification then
3899 Ent : constant Entity_Id :=
3900 Defining_Identifier (Citem);
3902 if Ekind (Ent) = E_Discriminant then
3903 Ncomps := Ncomps + 1;
3904 Comps (Ncomps) := Ent;
3913 -- Gather component entities into Comp
3915 Citem := First (Component_Items (CL));
3916 while Present (Citem) loop
3917 if Nkind (Citem) = N_Component_Declaration then
3918 Ncomps := Ncomps + 1;
3919 Comps (Ncomps) := Defining_Identifier (Citem);
3925 -- Now sort the component entities based on the first bit.
3926 -- Note we already know there are no overlapping components.
3928 Sorting.Sort (Ncomps);
3930 -- Loop through entries checking for holes
3933 for J in 1 .. Ncomps loop
3935 Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
3937 if Error_Msg_Uint_1 > 0 then
3939 ("?^-bit gap before component&",
3940 Component_Name (Component_Clause (CEnt)), CEnt);
3943 Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
3946 -- Process variant parts recursively if present
3948 if Present (Variant_Part (CL)) then
3949 Variant := First (Variants (Variant_Part (CL)));
3950 while Present (Variant) loop
3951 Check_Component_List
3952 (Component_List (Variant), Nbit, No_List);
3957 end Check_Component_List;
3959 -- Start of processing for Record_Hole_Check
3966 if Is_Tagged_Type (Rectype) then
3967 Sbit := UI_From_Int (System_Address_Size);
3972 if Nkind (Decl) = N_Full_Type_Declaration
3973 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
3975 Check_Component_List
3976 (Component_List (Type_Definition (Decl)),
3978 Discriminant_Specifications (Decl));
3981 end Record_Hole_Check;
3984 -- For records that have component clauses for all components, and whose
3985 -- size is less than or equal to 32, we need to know the size in the
3986 -- front end to activate possible packed array processing where the
3987 -- component type is a record.
3989 -- At this stage Hbit + 1 represents the first unused bit from all the
3990 -- component clauses processed, so if the component clauses are
3991 -- complete, then this is the length of the record.
3993 -- For records longer than System.Storage_Unit, and for those where not
3994 -- all components have component clauses, the back end determines the
3995 -- length (it may for example be appropriate to round up the size
3996 -- to some convenient boundary, based on alignment considerations, etc).
3998 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
4000 -- Nothing to do if at least one component has no component clause
4002 Comp := First_Component_Or_Discriminant (Rectype);
4003 while Present (Comp) loop
4004 exit when No (Component_Clause (Comp));
4005 Next_Component_Or_Discriminant (Comp);
4008 -- If we fall out of loop, all components have component clauses
4009 -- and so we can set the size to the maximum value.
4012 Set_RM_Size (Rectype, Hbit + 1);
4015 end Check_Record_Representation_Clause;
4021 procedure Check_Size
4025 Biased : out Boolean)
4027 UT : constant Entity_Id := Underlying_Type (T);
4033 -- Dismiss cases for generic types or types with previous errors
4036 or else UT = Any_Type
4037 or else Is_Generic_Type (UT)
4038 or else Is_Generic_Type (Root_Type (UT))
4042 -- Check case of bit packed array
4044 elsif Is_Array_Type (UT)
4045 and then Known_Static_Component_Size (UT)
4046 and then Is_Bit_Packed_Array (UT)
4054 Asiz := Component_Size (UT);
4055 Indx := First_Index (UT);
4057 Ityp := Etype (Indx);
4059 -- If non-static bound, then we are not in the business of
4060 -- trying to check the length, and indeed an error will be
4061 -- issued elsewhere, since sizes of non-static array types
4062 -- cannot be set implicitly or explicitly.
4064 if not Is_Static_Subtype (Ityp) then
4068 -- Otherwise accumulate next dimension
4070 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
4071 Expr_Value (Type_Low_Bound (Ityp)) +
4075 exit when No (Indx);
4081 Error_Msg_Uint_1 := Asiz;
4083 ("size for& too small, minimum allowed is ^", N, T);
4084 Set_Esize (T, Asiz);
4085 Set_RM_Size (T, Asiz);
4089 -- All other composite types are ignored
4091 elsif Is_Composite_Type (UT) then
4094 -- For fixed-point types, don't check minimum if type is not frozen,
4095 -- since we don't know all the characteristics of the type that can
4096 -- affect the size (e.g. a specified small) till freeze time.
4098 elsif Is_Fixed_Point_Type (UT)
4099 and then not Is_Frozen (UT)
4103 -- Cases for which a minimum check is required
4106 -- Ignore if specified size is correct for the type
4108 if Known_Esize (UT) and then Siz = Esize (UT) then
4112 -- Otherwise get minimum size
4114 M := UI_From_Int (Minimum_Size (UT));
4118 -- Size is less than minimum size, but one possibility remains
4119 -- that we can manage with the new size if we bias the type.
4121 M := UI_From_Int (Minimum_Size (UT, Biased => True));
4124 Error_Msg_Uint_1 := M;
4126 ("size for& too small, minimum allowed is ^", N, T);
4136 -------------------------
4137 -- Get_Alignment_Value --
4138 -------------------------
4140 function Get_Alignment_Value (Expr : Node_Id) return Uint is
4141 Align : constant Uint := Static_Integer (Expr);
4144 if Align = No_Uint then
4147 elsif Align <= 0 then
4148 Error_Msg_N ("alignment value must be positive", Expr);
4152 for J in Int range 0 .. 64 loop
4154 M : constant Uint := Uint_2 ** J;
4157 exit when M = Align;
4161 ("alignment value must be power of 2", Expr);
4169 end Get_Alignment_Value;
4175 procedure Initialize is
4177 Unchecked_Conversions.Init;
4180 -------------------------
4181 -- Is_Operational_Item --
4182 -------------------------
4184 function Is_Operational_Item (N : Node_Id) return Boolean is
4186 if Nkind (N) /= N_Attribute_Definition_Clause then
4190 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
4192 return Id = Attribute_Input
4193 or else Id = Attribute_Output
4194 or else Id = Attribute_Read
4195 or else Id = Attribute_Write
4196 or else Id = Attribute_External_Tag;
4199 end Is_Operational_Item;
4205 function Minimum_Size
4207 Biased : Boolean := False) return Nat
4209 Lo : Uint := No_Uint;
4210 Hi : Uint := No_Uint;
4211 LoR : Ureal := No_Ureal;
4212 HiR : Ureal := No_Ureal;
4213 LoSet : Boolean := False;
4214 HiSet : Boolean := False;
4218 R_Typ : constant Entity_Id := Root_Type (T);
4221 -- If bad type, return 0
4223 if T = Any_Type then
4226 -- For generic types, just return zero. There cannot be any legitimate
4227 -- need to know such a size, but this routine may be called with a
4228 -- generic type as part of normal processing.
4230 elsif Is_Generic_Type (R_Typ)
4231 or else R_Typ = Any_Type
4235 -- Access types. Normally an access type cannot have a size smaller
4236 -- than the size of System.Address. The exception is on VMS, where
4237 -- we have short and long addresses, and it is possible for an access
4238 -- type to have a short address size (and thus be less than the size
4239 -- of System.Address itself). We simply skip the check for VMS, and
4240 -- leave it to the back end to do the check.
4242 elsif Is_Access_Type (T) then
4243 if OpenVMS_On_Target then
4246 return System_Address_Size;
4249 -- Floating-point types
4251 elsif Is_Floating_Point_Type (T) then
4252 return UI_To_Int (Esize (R_Typ));
4256 elsif Is_Discrete_Type (T) then
4258 -- The following loop is looking for the nearest compile time known
4259 -- bounds following the ancestor subtype chain. The idea is to find
4260 -- the most restrictive known bounds information.
4264 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4269 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
4270 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
4277 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
4278 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
4284 Ancest := Ancestor_Subtype (Ancest);
4287 Ancest := Base_Type (T);
4289 if Is_Generic_Type (Ancest) then
4295 -- Fixed-point types. We can't simply use Expr_Value to get the
4296 -- Corresponding_Integer_Value values of the bounds, since these do not
4297 -- get set till the type is frozen, and this routine can be called
4298 -- before the type is frozen. Similarly the test for bounds being static
4299 -- needs to include the case where we have unanalyzed real literals for
4302 elsif Is_Fixed_Point_Type (T) then
4304 -- The following loop is looking for the nearest compile time known
4305 -- bounds following the ancestor subtype chain. The idea is to find
4306 -- the most restrictive known bounds information.
4310 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4314 -- Note: In the following two tests for LoSet and HiSet, it may
4315 -- seem redundant to test for N_Real_Literal here since normally
4316 -- one would assume that the test for the value being known at
4317 -- compile time includes this case. However, there is a glitch.
4318 -- If the real literal comes from folding a non-static expression,
4319 -- then we don't consider any non- static expression to be known
4320 -- at compile time if we are in configurable run time mode (needed
4321 -- in some cases to give a clearer definition of what is and what
4322 -- is not accepted). So the test is indeed needed. Without it, we
4323 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
4326 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
4327 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
4329 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
4336 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
4337 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
4339 HiR := Expr_Value_R (Type_High_Bound (Ancest));
4345 Ancest := Ancestor_Subtype (Ancest);
4348 Ancest := Base_Type (T);
4350 if Is_Generic_Type (Ancest) then
4356 Lo := UR_To_Uint (LoR / Small_Value (T));
4357 Hi := UR_To_Uint (HiR / Small_Value (T));
4359 -- No other types allowed
4362 raise Program_Error;
4365 -- Fall through with Hi and Lo set. Deal with biased case
4368 and then not Is_Fixed_Point_Type (T)
4369 and then not (Is_Enumeration_Type (T)
4370 and then Has_Non_Standard_Rep (T)))
4371 or else Has_Biased_Representation (T)
4377 -- Signed case. Note that we consider types like range 1 .. -1 to be
4378 -- signed for the purpose of computing the size, since the bounds have
4379 -- to be accommodated in the base type.
4381 if Lo < 0 or else Hi < 0 then
4385 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
4386 -- Note that we accommodate the case where the bounds cross. This
4387 -- can happen either because of the way the bounds are declared
4388 -- or because of the algorithm in Freeze_Fixed_Point_Type.
4402 -- If both bounds are positive, make sure that both are represen-
4403 -- table in the case where the bounds are crossed. This can happen
4404 -- either because of the way the bounds are declared, or because of
4405 -- the algorithm in Freeze_Fixed_Point_Type.
4411 -- S = size, (can accommodate 0 .. (2**size - 1))
4414 while Hi >= Uint_2 ** S loop
4422 ---------------------------
4423 -- New_Stream_Subprogram --
4424 ---------------------------
4426 procedure New_Stream_Subprogram
4430 Nam : TSS_Name_Type)
4432 Loc : constant Source_Ptr := Sloc (N);
4433 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
4434 Subp_Id : Entity_Id;
4435 Subp_Decl : Node_Id;
4439 Defer_Declaration : constant Boolean :=
4440 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
4441 -- For a tagged type, there is a declaration for each stream attribute
4442 -- at the freeze point, and we must generate only a completion of this
4443 -- declaration. We do the same for private types, because the full view
4444 -- might be tagged. Otherwise we generate a declaration at the point of
4445 -- the attribute definition clause.
4447 function Build_Spec return Node_Id;
4448 -- Used for declaration and renaming declaration, so that this is
4449 -- treated as a renaming_as_body.
4455 function Build_Spec return Node_Id is
4456 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
4459 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
4462 Subp_Id := Make_Defining_Identifier (Loc, Sname);
4464 -- S : access Root_Stream_Type'Class
4466 Formals := New_List (
4467 Make_Parameter_Specification (Loc,
4468 Defining_Identifier =>
4469 Make_Defining_Identifier (Loc, Name_S),
4471 Make_Access_Definition (Loc,
4474 Designated_Type (Etype (F)), Loc))));
4476 if Nam = TSS_Stream_Input then
4477 Spec := Make_Function_Specification (Loc,
4478 Defining_Unit_Name => Subp_Id,
4479 Parameter_Specifications => Formals,
4480 Result_Definition => T_Ref);
4485 Make_Parameter_Specification (Loc,
4486 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
4487 Out_Present => Out_P,
4488 Parameter_Type => T_Ref));
4491 Make_Procedure_Specification (Loc,
4492 Defining_Unit_Name => Subp_Id,
4493 Parameter_Specifications => Formals);
4499 -- Start of processing for New_Stream_Subprogram
4502 F := First_Formal (Subp);
4504 if Ekind (Subp) = E_Procedure then
4505 Etyp := Etype (Next_Formal (F));
4507 Etyp := Etype (Subp);
4510 -- Prepare subprogram declaration and insert it as an action on the
4511 -- clause node. The visibility for this entity is used to test for
4512 -- visibility of the attribute definition clause (in the sense of
4513 -- 8.3(23) as amended by AI-195).
4515 if not Defer_Declaration then
4517 Make_Subprogram_Declaration (Loc,
4518 Specification => Build_Spec);
4520 -- For a tagged type, there is always a visible declaration for each
4521 -- stream TSS (it is a predefined primitive operation), and the
4522 -- completion of this declaration occurs at the freeze point, which is
4523 -- not always visible at places where the attribute definition clause is
4524 -- visible. So, we create a dummy entity here for the purpose of
4525 -- tracking the visibility of the attribute definition clause itself.
4529 Make_Defining_Identifier (Loc,
4530 Chars => New_External_Name (Sname, 'V'));
4532 Make_Object_Declaration (Loc,
4533 Defining_Identifier => Subp_Id,
4534 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
4537 Insert_Action (N, Subp_Decl);
4538 Set_Entity (N, Subp_Id);
4541 Make_Subprogram_Renaming_Declaration (Loc,
4542 Specification => Build_Spec,
4543 Name => New_Reference_To (Subp, Loc));
4545 if Defer_Declaration then
4546 Set_TSS (Base_Type (Ent), Subp_Id);
4548 Insert_Action (N, Subp_Decl);
4549 Copy_TSS (Subp_Id, Base_Type (Ent));
4551 end New_Stream_Subprogram;
4553 ------------------------
4554 -- Rep_Item_Too_Early --
4555 ------------------------
4557 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
4559 -- Cannot apply non-operational rep items to generic types
4561 if Is_Operational_Item (N) then
4565 and then Is_Generic_Type (Root_Type (T))
4567 Error_Msg_N ("representation item not allowed for generic type", N);
4571 -- Otherwise check for incomplete type
4573 if Is_Incomplete_Or_Private_Type (T)
4574 and then No (Underlying_Type (T))
4577 ("representation item must be after full type declaration", N);
4580 -- If the type has incomplete components, a representation clause is
4581 -- illegal but stream attributes and Convention pragmas are correct.
4583 elsif Has_Private_Component (T) then
4584 if Nkind (N) = N_Pragma then
4588 ("representation item must appear after type is fully defined",
4595 end Rep_Item_Too_Early;
4597 -----------------------
4598 -- Rep_Item_Too_Late --
4599 -----------------------
4601 function Rep_Item_Too_Late
4604 FOnly : Boolean := False) return Boolean
4607 Parent_Type : Entity_Id;
4610 -- Output the too late message. Note that this is not considered a
4611 -- serious error, since the effect is simply that we ignore the
4612 -- representation clause in this case.
4618 procedure Too_Late is
4620 Error_Msg_N ("|representation item appears too late!", N);
4623 -- Start of processing for Rep_Item_Too_Late
4626 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
4627 -- types, which may be frozen if they appear in a representation clause
4628 -- for a local type.
4631 and then not From_With_Type (T)
4634 S := First_Subtype (T);
4636 if Present (Freeze_Node (S)) then
4638 ("?no more representation items for }", Freeze_Node (S), S);
4643 -- Check for case of non-tagged derived type whose parent either has
4644 -- primitive operations, or is a by reference type (RM 13.1(10)).
4648 and then Is_Derived_Type (T)
4649 and then not Is_Tagged_Type (T)
4651 Parent_Type := Etype (Base_Type (T));
4653 if Has_Primitive_Operations (Parent_Type) then
4656 ("primitive operations already defined for&!", N, Parent_Type);
4659 elsif Is_By_Reference_Type (Parent_Type) then
4662 ("parent type & is a by reference type!", N, Parent_Type);
4667 -- No error, link item into head of chain of rep items for the entity,
4668 -- but avoid chaining if we have an overloadable entity, and the pragma
4669 -- is one that can apply to multiple overloaded entities.
4671 if Is_Overloadable (T)
4672 and then Nkind (N) = N_Pragma
4675 Pname : constant Name_Id := Pragma_Name (N);
4677 if Pname = Name_Convention or else
4678 Pname = Name_Import or else
4679 Pname = Name_Export or else
4680 Pname = Name_External or else
4681 Pname = Name_Interface
4688 Record_Rep_Item (T, N);
4690 end Rep_Item_Too_Late;
4692 -------------------------
4693 -- Same_Representation --
4694 -------------------------
4696 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
4697 T1 : constant Entity_Id := Underlying_Type (Typ1);
4698 T2 : constant Entity_Id := Underlying_Type (Typ2);
4701 -- A quick check, if base types are the same, then we definitely have
4702 -- the same representation, because the subtype specific representation
4703 -- attributes (Size and Alignment) do not affect representation from
4704 -- the point of view of this test.
4706 if Base_Type (T1) = Base_Type (T2) then
4709 elsif Is_Private_Type (Base_Type (T2))
4710 and then Base_Type (T1) = Full_View (Base_Type (T2))
4715 -- Tagged types never have differing representations
4717 if Is_Tagged_Type (T1) then
4721 -- Representations are definitely different if conventions differ
4723 if Convention (T1) /= Convention (T2) then
4727 -- Representations are different if component alignments differ
4729 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4731 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4732 and then Component_Alignment (T1) /= Component_Alignment (T2)
4737 -- For arrays, the only real issue is component size. If we know the
4738 -- component size for both arrays, and it is the same, then that's
4739 -- good enough to know we don't have a change of representation.
4741 if Is_Array_Type (T1) then
4742 if Known_Component_Size (T1)
4743 and then Known_Component_Size (T2)
4744 and then Component_Size (T1) = Component_Size (T2)
4750 -- Types definitely have same representation if neither has non-standard
4751 -- representation since default representations are always consistent.
4752 -- If only one has non-standard representation, and the other does not,
4753 -- then we consider that they do not have the same representation. They
4754 -- might, but there is no way of telling early enough.
4756 if Has_Non_Standard_Rep (T1) then
4757 if not Has_Non_Standard_Rep (T2) then
4761 return not Has_Non_Standard_Rep (T2);
4764 -- Here the two types both have non-standard representation, and we need
4765 -- to determine if they have the same non-standard representation.
4767 -- For arrays, we simply need to test if the component sizes are the
4768 -- same. Pragma Pack is reflected in modified component sizes, so this
4769 -- check also deals with pragma Pack.
4771 if Is_Array_Type (T1) then
4772 return Component_Size (T1) = Component_Size (T2);
4774 -- Tagged types always have the same representation, because it is not
4775 -- possible to specify different representations for common fields.
4777 elsif Is_Tagged_Type (T1) then
4780 -- Case of record types
4782 elsif Is_Record_Type (T1) then
4784 -- Packed status must conform
4786 if Is_Packed (T1) /= Is_Packed (T2) then
4789 -- Otherwise we must check components. Typ2 maybe a constrained
4790 -- subtype with fewer components, so we compare the components
4791 -- of the base types.
4794 Record_Case : declare
4795 CD1, CD2 : Entity_Id;
4797 function Same_Rep return Boolean;
4798 -- CD1 and CD2 are either components or discriminants. This
4799 -- function tests whether the two have the same representation
4805 function Same_Rep return Boolean is
4807 if No (Component_Clause (CD1)) then
4808 return No (Component_Clause (CD2));
4812 Present (Component_Clause (CD2))
4814 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4816 Esize (CD1) = Esize (CD2);
4820 -- Start of processing for Record_Case
4823 if Has_Discriminants (T1) then
4824 CD1 := First_Discriminant (T1);
4825 CD2 := First_Discriminant (T2);
4827 -- The number of discriminants may be different if the
4828 -- derived type has fewer (constrained by values). The
4829 -- invisible discriminants retain the representation of
4830 -- the original, so the discrepancy does not per se
4831 -- indicate a different representation.
4834 and then Present (CD2)
4836 if not Same_Rep then
4839 Next_Discriminant (CD1);
4840 Next_Discriminant (CD2);
4845 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4846 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4848 while Present (CD1) loop
4849 if not Same_Rep then
4852 Next_Component (CD1);
4853 Next_Component (CD2);
4861 -- For enumeration types, we must check each literal to see if the
4862 -- representation is the same. Note that we do not permit enumeration
4863 -- representation clauses for Character and Wide_Character, so these
4864 -- cases were already dealt with.
4866 elsif Is_Enumeration_Type (T1) then
4867 Enumeration_Case : declare
4871 L1 := First_Literal (T1);
4872 L2 := First_Literal (T2);
4874 while Present (L1) loop
4875 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4885 end Enumeration_Case;
4887 -- Any other types have the same representation for these purposes
4892 end Same_Representation;
4898 procedure Set_Biased
4902 Biased : Boolean := True)
4906 Set_Has_Biased_Representation (E);
4908 if Warn_On_Biased_Representation then
4910 ("?" & Msg & " forces biased representation for&", N, E);
4915 --------------------
4916 -- Set_Enum_Esize --
4917 --------------------
4919 procedure Set_Enum_Esize (T : Entity_Id) is
4927 -- Find the minimum standard size (8,16,32,64) that fits
4929 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4930 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4933 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4934 Sz := Standard_Character_Size; -- May be > 8 on some targets
4936 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4939 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4942 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4947 if Hi < Uint_2**08 then
4948 Sz := Standard_Character_Size; -- May be > 8 on some targets
4950 elsif Hi < Uint_2**16 then
4953 elsif Hi < Uint_2**32 then
4956 else pragma Assert (Hi < Uint_2**63);
4961 -- That minimum is the proper size unless we have a foreign convention
4962 -- and the size required is 32 or less, in which case we bump the size
4963 -- up to 32. This is required for C and C++ and seems reasonable for
4964 -- all other foreign conventions.
4966 if Has_Foreign_Convention (T)
4967 and then Esize (T) < Standard_Integer_Size
4969 Init_Esize (T, Standard_Integer_Size);
4975 ------------------------------
4976 -- Validate_Address_Clauses --
4977 ------------------------------
4979 procedure Validate_Address_Clauses is
4981 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4983 ACCR : Address_Clause_Check_Record
4984 renames Address_Clause_Checks.Table (J);
4995 -- Skip processing of this entry if warning already posted
4997 if not Address_Warning_Posted (ACCR.N) then
4999 Expr := Original_Node (Expression (ACCR.N));
5003 X_Alignment := Alignment (ACCR.X);
5004 Y_Alignment := Alignment (ACCR.Y);
5006 -- Similarly obtain sizes
5008 X_Size := Esize (ACCR.X);
5009 Y_Size := Esize (ACCR.Y);
5011 -- Check for large object overlaying smaller one
5014 and then X_Size > Uint_0
5015 and then X_Size > Y_Size
5018 ("?& overlays smaller object", ACCR.N, ACCR.X);
5020 ("\?program execution may be erroneous", ACCR.N);
5021 Error_Msg_Uint_1 := X_Size;
5023 ("\?size of & is ^", ACCR.N, ACCR.X);
5024 Error_Msg_Uint_1 := Y_Size;
5026 ("\?size of & is ^", ACCR.N, ACCR.Y);
5028 -- Check for inadequate alignment, both of the base object
5029 -- and of the offset, if any.
5031 -- Note: we do not check the alignment if we gave a size
5032 -- warning, since it would likely be redundant.
5034 elsif Y_Alignment /= Uint_0
5035 and then (Y_Alignment < X_Alignment
5038 Nkind (Expr) = N_Attribute_Reference
5040 Attribute_Name (Expr) = Name_Address
5042 Has_Compatible_Alignment
5043 (ACCR.X, Prefix (Expr))
5044 /= Known_Compatible))
5047 ("?specified address for& may be inconsistent "
5051 ("\?program execution may be erroneous (RM 13.3(27))",
5053 Error_Msg_Uint_1 := X_Alignment;
5055 ("\?alignment of & is ^",
5057 Error_Msg_Uint_1 := Y_Alignment;
5059 ("\?alignment of & is ^",
5061 if Y_Alignment >= X_Alignment then
5063 ("\?but offset is not multiple of alignment",
5070 end Validate_Address_Clauses;
5072 -----------------------------------
5073 -- Validate_Unchecked_Conversion --
5074 -----------------------------------
5076 procedure Validate_Unchecked_Conversion
5078 Act_Unit : Entity_Id)
5085 -- Obtain source and target types. Note that we call Ancestor_Subtype
5086 -- here because the processing for generic instantiation always makes
5087 -- subtypes, and we want the original frozen actual types.
5089 -- If we are dealing with private types, then do the check on their
5090 -- fully declared counterparts if the full declarations have been
5091 -- encountered (they don't have to be visible, but they must exist!)
5093 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
5095 if Is_Private_Type (Source)
5096 and then Present (Underlying_Type (Source))
5098 Source := Underlying_Type (Source);
5101 Target := Ancestor_Subtype (Etype (Act_Unit));
5103 -- If either type is generic, the instantiation happens within a generic
5104 -- unit, and there is nothing to check. The proper check
5105 -- will happen when the enclosing generic is instantiated.
5107 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
5111 if Is_Private_Type (Target)
5112 and then Present (Underlying_Type (Target))
5114 Target := Underlying_Type (Target);
5117 -- Source may be unconstrained array, but not target
5119 if Is_Array_Type (Target)
5120 and then not Is_Constrained (Target)
5123 ("unchecked conversion to unconstrained array not allowed", N);
5127 -- Warn if conversion between two different convention pointers
5129 if Is_Access_Type (Target)
5130 and then Is_Access_Type (Source)
5131 and then Convention (Target) /= Convention (Source)
5132 and then Warn_On_Unchecked_Conversion
5134 -- Give warnings for subprogram pointers only on most targets. The
5135 -- exception is VMS, where data pointers can have different lengths
5136 -- depending on the pointer convention.
5138 if Is_Access_Subprogram_Type (Target)
5139 or else Is_Access_Subprogram_Type (Source)
5140 or else OpenVMS_On_Target
5143 ("?conversion between pointers with different conventions!", N);
5147 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
5148 -- warning when compiling GNAT-related sources.
5150 if Warn_On_Unchecked_Conversion
5151 and then not In_Predefined_Unit (N)
5152 and then RTU_Loaded (Ada_Calendar)
5154 (Chars (Source) = Name_Time
5156 Chars (Target) = Name_Time)
5158 -- If Ada.Calendar is loaded and the name of one of the operands is
5159 -- Time, there is a good chance that this is Ada.Calendar.Time.
5162 Calendar_Time : constant Entity_Id :=
5163 Full_View (RTE (RO_CA_Time));
5165 pragma Assert (Present (Calendar_Time));
5167 if Source = Calendar_Time
5168 or else Target = Calendar_Time
5171 ("?representation of 'Time values may change between " &
5172 "'G'N'A'T versions", N);
5177 -- Make entry in unchecked conversion table for later processing by
5178 -- Validate_Unchecked_Conversions, which will check sizes and alignments
5179 -- (using values set by the back-end where possible). This is only done
5180 -- if the appropriate warning is active.
5182 if Warn_On_Unchecked_Conversion then
5183 Unchecked_Conversions.Append
5184 (New_Val => UC_Entry'
5189 -- If both sizes are known statically now, then back end annotation
5190 -- is not required to do a proper check but if either size is not
5191 -- known statically, then we need the annotation.
5193 if Known_Static_RM_Size (Source)
5194 and then Known_Static_RM_Size (Target)
5198 Back_Annotate_Rep_Info := True;
5202 -- If unchecked conversion to access type, and access type is declared
5203 -- in the same unit as the unchecked conversion, then set the
5204 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
5207 if Is_Access_Type (Target) and then
5208 In_Same_Source_Unit (Target, N)
5210 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
5213 -- Generate N_Validate_Unchecked_Conversion node for back end in
5214 -- case the back end needs to perform special validation checks.
5216 -- Shouldn't this be in Exp_Ch13, since the check only gets done
5217 -- if we have full expansion and the back end is called ???
5220 Make_Validate_Unchecked_Conversion (Sloc (N));
5221 Set_Source_Type (Vnode, Source);
5222 Set_Target_Type (Vnode, Target);
5224 -- If the unchecked conversion node is in a list, just insert before it.
5225 -- If not we have some strange case, not worth bothering about.
5227 if Is_List_Member (N) then
5228 Insert_After (N, Vnode);
5230 end Validate_Unchecked_Conversion;
5232 ------------------------------------
5233 -- Validate_Unchecked_Conversions --
5234 ------------------------------------
5236 procedure Validate_Unchecked_Conversions is
5238 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
5240 T : UC_Entry renames Unchecked_Conversions.Table (N);
5242 Eloc : constant Source_Ptr := T.Eloc;
5243 Source : constant Entity_Id := T.Source;
5244 Target : constant Entity_Id := T.Target;
5250 -- This validation check, which warns if we have unequal sizes for
5251 -- unchecked conversion, and thus potentially implementation
5252 -- dependent semantics, is one of the few occasions on which we
5253 -- use the official RM size instead of Esize. See description in
5254 -- Einfo "Handling of Type'Size Values" for details.
5256 if Serious_Errors_Detected = 0
5257 and then Known_Static_RM_Size (Source)
5258 and then Known_Static_RM_Size (Target)
5260 -- Don't do the check if warnings off for either type, note the
5261 -- deliberate use of OR here instead of OR ELSE to get the flag
5262 -- Warnings_Off_Used set for both types if appropriate.
5264 and then not (Has_Warnings_Off (Source)
5266 Has_Warnings_Off (Target))
5268 Source_Siz := RM_Size (Source);
5269 Target_Siz := RM_Size (Target);
5271 if Source_Siz /= Target_Siz then
5273 ("?types for unchecked conversion have different sizes!",
5276 if All_Errors_Mode then
5277 Error_Msg_Name_1 := Chars (Source);
5278 Error_Msg_Uint_1 := Source_Siz;
5279 Error_Msg_Name_2 := Chars (Target);
5280 Error_Msg_Uint_2 := Target_Siz;
5281 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
5283 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
5285 if Is_Discrete_Type (Source)
5286 and then Is_Discrete_Type (Target)
5288 if Source_Siz > Target_Siz then
5290 ("\?^ high order bits of source will be ignored!",
5293 elsif Is_Unsigned_Type (Source) then
5295 ("\?source will be extended with ^ high order " &
5296 "zero bits?!", Eloc);
5300 ("\?source will be extended with ^ high order " &
5305 elsif Source_Siz < Target_Siz then
5306 if Is_Discrete_Type (Target) then
5307 if Bytes_Big_Endian then
5309 ("\?target value will include ^ undefined " &
5314 ("\?target value will include ^ undefined " &
5321 ("\?^ trailing bits of target value will be " &
5322 "undefined!", Eloc);
5325 else pragma Assert (Source_Siz > Target_Siz);
5327 ("\?^ trailing bits of source will be ignored!",
5334 -- If both types are access types, we need to check the alignment.
5335 -- If the alignment of both is specified, we can do it here.
5337 if Serious_Errors_Detected = 0
5338 and then Ekind (Source) in Access_Kind
5339 and then Ekind (Target) in Access_Kind
5340 and then Target_Strict_Alignment
5341 and then Present (Designated_Type (Source))
5342 and then Present (Designated_Type (Target))
5345 D_Source : constant Entity_Id := Designated_Type (Source);
5346 D_Target : constant Entity_Id := Designated_Type (Target);
5349 if Known_Alignment (D_Source)
5350 and then Known_Alignment (D_Target)
5353 Source_Align : constant Uint := Alignment (D_Source);
5354 Target_Align : constant Uint := Alignment (D_Target);
5357 if Source_Align < Target_Align
5358 and then not Is_Tagged_Type (D_Source)
5360 -- Suppress warning if warnings suppressed on either
5361 -- type or either designated type. Note the use of
5362 -- OR here instead of OR ELSE. That is intentional,
5363 -- we would like to set flag Warnings_Off_Used in
5364 -- all types for which warnings are suppressed.
5366 and then not (Has_Warnings_Off (D_Source)
5368 Has_Warnings_Off (D_Target)
5370 Has_Warnings_Off (Source)
5372 Has_Warnings_Off (Target))
5374 Error_Msg_Uint_1 := Target_Align;
5375 Error_Msg_Uint_2 := Source_Align;
5376 Error_Msg_Node_1 := D_Target;
5377 Error_Msg_Node_2 := D_Source;
5379 ("?alignment of & (^) is stricter than " &
5380 "alignment of & (^)!", Eloc);
5382 ("\?resulting access value may have invalid " &
5383 "alignment!", Eloc);
5391 end Validate_Unchecked_Conversions;