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;
1301 Ignore : Boolean := False;
1303 procedure Complain_CS (T : String);
1304 -- Outputs error messages for incorrect CS clause for aliased or
1305 -- atomic components (T is "aliased" or "atomic");
1311 procedure Complain_CS (T : String) is
1313 if Known_Static_Esize (Ctyp) then
1315 ("incorrect component size for " & T & " components", N);
1316 Error_Msg_Uint_1 := Esize (Ctyp);
1317 Error_Msg_N ("\only allowed value is^", N);
1321 ("component size cannot be given for " & T & " components",
1328 -- Start of processing for Component_Size_Case
1331 if not Is_Array_Type (U_Ent) then
1332 Error_Msg_N ("component size requires array type", Nam);
1336 Btype := Base_Type (U_Ent);
1337 Ctyp := Component_Type (Btype);
1339 if Has_Component_Size_Clause (Btype) then
1341 ("component size clause for& previously given", Nam);
1343 elsif Csize /= No_Uint then
1344 Check_Size (Expr, Ctyp, Csize, Biased);
1346 -- Case where component size has no effect
1348 if Known_Static_Esize (Ctyp)
1349 and then Known_Static_RM_Size (Ctyp)
1350 and then Esize (Ctyp) = RM_Size (Ctyp)
1351 and then (Esize (Ctyp) = 8 or else
1352 Esize (Ctyp) = 16 or else
1353 Esize (Ctyp) = 32 or else
1358 -- Cannot give component size for aliased/atomic types
1360 elsif Has_Aliased_Components (Btype) then
1361 Complain_CS ("aliased");
1363 elsif Has_Atomic_Components (Btype) then
1364 Complain_CS ("atomic");
1367 -- For the biased case, build a declaration for a subtype
1368 -- that will be used to represent the biased subtype that
1369 -- reflects the biased representation of components. We need
1370 -- this subtype to get proper conversions on referencing
1371 -- elements of the array. Note that component size clauses
1372 -- are ignored in VM mode.
1374 if VM_Target = No_VM then
1377 Make_Defining_Identifier (Loc,
1379 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1382 Make_Subtype_Declaration (Loc,
1383 Defining_Identifier => New_Ctyp,
1384 Subtype_Indication =>
1385 New_Occurrence_Of (Component_Type (Btype), Loc));
1387 Set_Parent (Decl, N);
1388 Analyze (Decl, Suppress => All_Checks);
1390 Set_Has_Delayed_Freeze (New_Ctyp, False);
1391 Set_Esize (New_Ctyp, Csize);
1392 Set_RM_Size (New_Ctyp, Csize);
1393 Init_Alignment (New_Ctyp);
1394 Set_Is_Itype (New_Ctyp, True);
1395 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1397 Set_Component_Type (Btype, New_Ctyp);
1398 Set_Biased (New_Ctyp, N, "component size clause");
1401 Set_Component_Size (Btype, Csize);
1403 -- For VM case, we ignore component size clauses
1406 -- Give a warning unless we are in GNAT mode, in which case
1407 -- the warning is suppressed since it is not useful.
1409 if not GNAT_Mode then
1411 ("?component size ignored in this configuration", N);
1415 -- Deal with warning on overridden size
1417 if Warn_On_Overridden_Size
1418 and then Has_Size_Clause (Ctyp)
1419 and then RM_Size (Ctyp) /= Csize
1422 ("?component size overrides size clause for&",
1426 Set_Has_Component_Size_Clause (Btype, True);
1429 Set_Has_Non_Standard_Rep (Btype, True);
1432 end Component_Size_Case;
1438 when Attribute_External_Tag => External_Tag :
1440 if not Is_Tagged_Type (U_Ent) then
1441 Error_Msg_N ("should be a tagged type", Nam);
1444 Analyze_And_Resolve (Expr, Standard_String);
1446 if not Is_Static_Expression (Expr) then
1447 Flag_Non_Static_Expr
1448 ("static string required for tag name!", Nam);
1451 if VM_Target = No_VM then
1452 Set_Has_External_Tag_Rep_Clause (U_Ent);
1454 Error_Msg_Name_1 := Attr;
1456 ("% attribute unsupported in this configuration", Nam);
1459 if not Is_Library_Level_Entity (U_Ent) then
1461 ("?non-unique external tag supplied for &", N, U_Ent);
1463 ("?\same external tag applies to all subprogram calls", N);
1465 ("?\corresponding internal tag cannot be obtained", N);
1473 when Attribute_Input =>
1474 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1475 Set_Has_Specified_Stream_Input (Ent);
1481 -- Machine radix attribute definition clause
1483 when Attribute_Machine_Radix => Machine_Radix : declare
1484 Radix : constant Uint := Static_Integer (Expr);
1487 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1488 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1490 elsif Has_Machine_Radix_Clause (U_Ent) then
1491 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1492 Error_Msg_N ("machine radix clause previously given#", N);
1494 elsif Radix /= No_Uint then
1495 Set_Has_Machine_Radix_Clause (U_Ent);
1496 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1500 elsif Radix = 10 then
1501 Set_Machine_Radix_10 (U_Ent);
1503 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1512 -- Object_Size attribute definition clause
1514 when Attribute_Object_Size => Object_Size : declare
1515 Size : constant Uint := Static_Integer (Expr);
1518 pragma Warnings (Off, Biased);
1521 if not Is_Type (U_Ent) then
1522 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1524 elsif Has_Object_Size_Clause (U_Ent) then
1525 Error_Msg_N ("Object_Size already given for &", Nam);
1528 Check_Size (Expr, U_Ent, Size, Biased);
1536 UI_Mod (Size, 64) /= 0
1539 ("Object_Size must be 8, 16, 32, or multiple of 64",
1543 Set_Esize (U_Ent, Size);
1544 Set_Has_Object_Size_Clause (U_Ent);
1545 Alignment_Check_For_Esize_Change (U_Ent);
1553 when Attribute_Output =>
1554 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1555 Set_Has_Specified_Stream_Output (Ent);
1561 when Attribute_Read =>
1562 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1563 Set_Has_Specified_Stream_Read (Ent);
1569 -- Size attribute definition clause
1571 when Attribute_Size => Size : declare
1572 Size : constant Uint := Static_Integer (Expr);
1579 if Has_Size_Clause (U_Ent) then
1580 Error_Msg_N ("size already given for &", Nam);
1582 elsif not Is_Type (U_Ent)
1583 and then Ekind (U_Ent) /= E_Variable
1584 and then Ekind (U_Ent) /= E_Constant
1586 Error_Msg_N ("size cannot be given for &", Nam);
1588 elsif Is_Array_Type (U_Ent)
1589 and then not Is_Constrained (U_Ent)
1592 ("size cannot be given for unconstrained array", Nam);
1594 elsif Size /= No_Uint then
1596 if VM_Target /= No_VM and then not GNAT_Mode then
1598 -- Size clause is not handled properly on VM targets.
1599 -- Display a warning unless we are in GNAT mode, in which
1600 -- case this is useless.
1603 ("?size clauses are ignored in this configuration", N);
1606 if Is_Type (U_Ent) then
1609 Etyp := Etype (U_Ent);
1612 -- Check size, note that Gigi is in charge of checking that the
1613 -- size of an array or record type is OK. Also we do not check
1614 -- the size in the ordinary fixed-point case, since it is too
1615 -- early to do so (there may be subsequent small clause that
1616 -- affects the size). We can check the size if a small clause
1617 -- has already been given.
1619 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1620 or else Has_Small_Clause (U_Ent)
1622 Check_Size (Expr, Etyp, Size, Biased);
1623 Set_Biased (U_Ent, N, "size clause", Biased);
1626 -- For types set RM_Size and Esize if possible
1628 if Is_Type (U_Ent) then
1629 Set_RM_Size (U_Ent, Size);
1631 -- For scalar types, increase Object_Size to power of 2, but
1632 -- not less than a storage unit in any case (i.e., normally
1633 -- this means it will be byte addressable).
1635 if Is_Scalar_Type (U_Ent) then
1636 if Size <= System_Storage_Unit then
1637 Init_Esize (U_Ent, System_Storage_Unit);
1638 elsif Size <= 16 then
1639 Init_Esize (U_Ent, 16);
1640 elsif Size <= 32 then
1641 Init_Esize (U_Ent, 32);
1643 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1646 -- For all other types, object size = value size. The
1647 -- backend will adjust as needed.
1650 Set_Esize (U_Ent, Size);
1653 Alignment_Check_For_Esize_Change (U_Ent);
1655 -- For objects, set Esize only
1658 if Is_Elementary_Type (Etyp) then
1659 if Size /= System_Storage_Unit
1661 Size /= System_Storage_Unit * 2
1663 Size /= System_Storage_Unit * 4
1665 Size /= System_Storage_Unit * 8
1667 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1668 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1670 ("size for primitive object must be a power of 2"
1671 & " in the range ^-^", N);
1675 Set_Esize (U_Ent, Size);
1678 Set_Has_Size_Clause (U_Ent);
1686 -- Small attribute definition clause
1688 when Attribute_Small => Small : declare
1689 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1693 Analyze_And_Resolve (Expr, Any_Real);
1695 if Etype (Expr) = Any_Type then
1698 elsif not Is_Static_Expression (Expr) then
1699 Flag_Non_Static_Expr
1700 ("small requires static expression!", Expr);
1704 Small := Expr_Value_R (Expr);
1706 if Small <= Ureal_0 then
1707 Error_Msg_N ("small value must be greater than zero", Expr);
1713 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1715 ("small requires an ordinary fixed point type", Nam);
1717 elsif Has_Small_Clause (U_Ent) then
1718 Error_Msg_N ("small already given for &", Nam);
1720 elsif Small > Delta_Value (U_Ent) then
1722 ("small value must not be greater then delta value", Nam);
1725 Set_Small_Value (U_Ent, Small);
1726 Set_Small_Value (Implicit_Base, Small);
1727 Set_Has_Small_Clause (U_Ent);
1728 Set_Has_Small_Clause (Implicit_Base);
1729 Set_Has_Non_Standard_Rep (Implicit_Base);
1737 -- Storage_Pool attribute definition clause
1739 when Attribute_Storage_Pool => Storage_Pool : declare
1744 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1746 ("storage pool cannot be given for access-to-subprogram type",
1751 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
1754 ("storage pool can only be given for access types", Nam);
1757 elsif Is_Derived_Type (U_Ent) then
1759 ("storage pool cannot be given for a derived access type",
1762 elsif Has_Storage_Size_Clause (U_Ent) then
1763 Error_Msg_N ("storage size already given for &", Nam);
1766 elsif Present (Associated_Storage_Pool (U_Ent)) then
1767 Error_Msg_N ("storage pool already given for &", Nam);
1772 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1774 if not Denotes_Variable (Expr) then
1775 Error_Msg_N ("storage pool must be a variable", Expr);
1779 if Nkind (Expr) = N_Type_Conversion then
1780 T := Etype (Expression (Expr));
1785 -- The Stack_Bounded_Pool is used internally for implementing
1786 -- access types with a Storage_Size. Since it only work
1787 -- properly when used on one specific type, we need to check
1788 -- that it is not hijacked improperly:
1789 -- type T is access Integer;
1790 -- for T'Storage_Size use n;
1791 -- type Q is access Float;
1792 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1794 if RTE_Available (RE_Stack_Bounded_Pool)
1795 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1797 Error_Msg_N ("non-shareable internal Pool", Expr);
1801 -- If the argument is a name that is not an entity name, then
1802 -- we construct a renaming operation to define an entity of
1803 -- type storage pool.
1805 if not Is_Entity_Name (Expr)
1806 and then Is_Object_Reference (Expr)
1808 Pool := Make_Temporary (Loc, 'P', Expr);
1811 Rnode : constant Node_Id :=
1812 Make_Object_Renaming_Declaration (Loc,
1813 Defining_Identifier => Pool,
1815 New_Occurrence_Of (Etype (Expr), Loc),
1819 Insert_Before (N, Rnode);
1821 Set_Associated_Storage_Pool (U_Ent, Pool);
1824 elsif Is_Entity_Name (Expr) then
1825 Pool := Entity (Expr);
1827 -- If pool is a renamed object, get original one. This can
1828 -- happen with an explicit renaming, and within instances.
1830 while Present (Renamed_Object (Pool))
1831 and then Is_Entity_Name (Renamed_Object (Pool))
1833 Pool := Entity (Renamed_Object (Pool));
1836 if Present (Renamed_Object (Pool))
1837 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1838 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1840 Pool := Entity (Expression (Renamed_Object (Pool)));
1843 Set_Associated_Storage_Pool (U_Ent, Pool);
1845 elsif Nkind (Expr) = N_Type_Conversion
1846 and then Is_Entity_Name (Expression (Expr))
1847 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1849 Pool := Entity (Expression (Expr));
1850 Set_Associated_Storage_Pool (U_Ent, Pool);
1853 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1862 -- Storage_Size attribute definition clause
1864 when Attribute_Storage_Size => Storage_Size : declare
1865 Btype : constant Entity_Id := Base_Type (U_Ent);
1869 if Is_Task_Type (U_Ent) then
1870 Check_Restriction (No_Obsolescent_Features, N);
1872 if Warn_On_Obsolescent_Feature then
1874 ("storage size clause for task is an " &
1875 "obsolescent feature (RM J.9)?", N);
1876 Error_Msg_N ("\use Storage_Size pragma instead?", N);
1882 if not Is_Access_Type (U_Ent)
1883 and then Ekind (U_Ent) /= E_Task_Type
1885 Error_Msg_N ("storage size cannot be given for &", Nam);
1887 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1889 ("storage size cannot be given for a derived access type",
1892 elsif Has_Storage_Size_Clause (Btype) then
1893 Error_Msg_N ("storage size already given for &", Nam);
1896 Analyze_And_Resolve (Expr, Any_Integer);
1898 if Is_Access_Type (U_Ent) then
1899 if Present (Associated_Storage_Pool (U_Ent)) then
1900 Error_Msg_N ("storage pool already given for &", Nam);
1904 if Is_OK_Static_Expression (Expr)
1905 and then Expr_Value (Expr) = 0
1907 Set_No_Pool_Assigned (Btype);
1910 else -- Is_Task_Type (U_Ent)
1911 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1913 if Present (Sprag) then
1914 Error_Msg_Sloc := Sloc (Sprag);
1916 ("Storage_Size already specified#", Nam);
1921 Set_Has_Storage_Size_Clause (Btype);
1929 when Attribute_Stream_Size => Stream_Size : declare
1930 Size : constant Uint := Static_Integer (Expr);
1933 if Ada_Version <= Ada_95 then
1934 Check_Restriction (No_Implementation_Attributes, N);
1937 if Has_Stream_Size_Clause (U_Ent) then
1938 Error_Msg_N ("Stream_Size already given for &", Nam);
1940 elsif Is_Elementary_Type (U_Ent) then
1941 if Size /= System_Storage_Unit
1943 Size /= System_Storage_Unit * 2
1945 Size /= System_Storage_Unit * 4
1947 Size /= System_Storage_Unit * 8
1949 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1951 ("stream size for elementary type must be a"
1952 & " power of 2 and at least ^", N);
1954 elsif RM_Size (U_Ent) > Size then
1955 Error_Msg_Uint_1 := RM_Size (U_Ent);
1957 ("stream size for elementary type must be a"
1958 & " power of 2 and at least ^", N);
1961 Set_Has_Stream_Size_Clause (U_Ent);
1964 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1972 -- Value_Size attribute definition clause
1974 when Attribute_Value_Size => Value_Size : declare
1975 Size : constant Uint := Static_Integer (Expr);
1979 if not Is_Type (U_Ent) then
1980 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1983 (Get_Attribute_Definition_Clause
1984 (U_Ent, Attribute_Value_Size))
1986 Error_Msg_N ("Value_Size already given for &", Nam);
1988 elsif Is_Array_Type (U_Ent)
1989 and then not Is_Constrained (U_Ent)
1992 ("Value_Size cannot be given for unconstrained array", Nam);
1995 if Is_Elementary_Type (U_Ent) then
1996 Check_Size (Expr, U_Ent, Size, Biased);
1997 Set_Biased (U_Ent, N, "value size clause", Biased);
2000 Set_RM_Size (U_Ent, Size);
2008 when Attribute_Write =>
2009 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
2010 Set_Has_Specified_Stream_Write (Ent);
2012 -- All other attributes cannot be set
2016 ("attribute& cannot be set with definition clause", N);
2019 -- The test for the type being frozen must be performed after
2020 -- any expression the clause has been analyzed since the expression
2021 -- itself might cause freezing that makes the clause illegal.
2023 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
2026 end Analyze_Attribute_Definition_Clause;
2028 ----------------------------
2029 -- Analyze_Code_Statement --
2030 ----------------------------
2032 procedure Analyze_Code_Statement (N : Node_Id) is
2033 HSS : constant Node_Id := Parent (N);
2034 SBody : constant Node_Id := Parent (HSS);
2035 Subp : constant Entity_Id := Current_Scope;
2042 -- Analyze and check we get right type, note that this implements the
2043 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
2044 -- is the only way that Asm_Insn could possibly be visible.
2046 Analyze_And_Resolve (Expression (N));
2048 if Etype (Expression (N)) = Any_Type then
2050 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
2051 Error_Msg_N ("incorrect type for code statement", N);
2055 Check_Code_Statement (N);
2057 -- Make sure we appear in the handled statement sequence of a
2058 -- subprogram (RM 13.8(3)).
2060 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2061 or else Nkind (SBody) /= N_Subprogram_Body
2064 ("code statement can only appear in body of subprogram", N);
2068 -- Do remaining checks (RM 13.8(3)) if not already done
2070 if not Is_Machine_Code_Subprogram (Subp) then
2071 Set_Is_Machine_Code_Subprogram (Subp);
2073 -- No exception handlers allowed
2075 if Present (Exception_Handlers (HSS)) then
2077 ("exception handlers not permitted in machine code subprogram",
2078 First (Exception_Handlers (HSS)));
2081 -- No declarations other than use clauses and pragmas (we allow
2082 -- certain internally generated declarations as well).
2084 Decl := First (Declarations (SBody));
2085 while Present (Decl) loop
2086 DeclO := Original_Node (Decl);
2087 if Comes_From_Source (DeclO)
2088 and not Nkind_In (DeclO, N_Pragma,
2089 N_Use_Package_Clause,
2091 N_Implicit_Label_Declaration)
2094 ("this declaration not allowed in machine code subprogram",
2101 -- No statements other than code statements, pragmas, and labels.
2102 -- Again we allow certain internally generated statements.
2104 Stmt := First (Statements (HSS));
2105 while Present (Stmt) loop
2106 StmtO := Original_Node (Stmt);
2107 if Comes_From_Source (StmtO)
2108 and then not Nkind_In (StmtO, N_Pragma,
2113 ("this statement is not allowed in machine code subprogram",
2120 end Analyze_Code_Statement;
2122 -----------------------------------------------
2123 -- Analyze_Enumeration_Representation_Clause --
2124 -----------------------------------------------
2126 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2127 Ident : constant Node_Id := Identifier (N);
2128 Aggr : constant Node_Id := Array_Aggregate (N);
2129 Enumtype : Entity_Id;
2135 Err : Boolean := False;
2137 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2138 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2139 -- Allowed range of universal integer (= allowed range of enum lit vals)
2143 -- Minimum and maximum values of entries
2146 -- Pointer to node for literal providing max value
2149 if Ignore_Rep_Clauses then
2153 -- First some basic error checks
2156 Enumtype := Entity (Ident);
2158 if Enumtype = Any_Type
2159 or else Rep_Item_Too_Early (Enumtype, N)
2163 Enumtype := Underlying_Type (Enumtype);
2166 if not Is_Enumeration_Type (Enumtype) then
2168 ("enumeration type required, found}",
2169 Ident, First_Subtype (Enumtype));
2173 -- Ignore rep clause on generic actual type. This will already have
2174 -- been flagged on the template as an error, and this is the safest
2175 -- way to ensure we don't get a junk cascaded message in the instance.
2177 if Is_Generic_Actual_Type (Enumtype) then
2180 -- Type must be in current scope
2182 elsif Scope (Enumtype) /= Current_Scope then
2183 Error_Msg_N ("type must be declared in this scope", Ident);
2186 -- Type must be a first subtype
2188 elsif not Is_First_Subtype (Enumtype) then
2189 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2192 -- Ignore duplicate rep clause
2194 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2195 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2198 -- Don't allow rep clause for standard [wide_[wide_]]character
2200 elsif Is_Standard_Character_Type (Enumtype) then
2201 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2204 -- Check that the expression is a proper aggregate (no parentheses)
2206 elsif Paren_Count (Aggr) /= 0 then
2208 ("extra parentheses surrounding aggregate not allowed",
2212 -- All tests passed, so set rep clause in place
2215 Set_Has_Enumeration_Rep_Clause (Enumtype);
2216 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2219 -- Now we process the aggregate. Note that we don't use the normal
2220 -- aggregate code for this purpose, because we don't want any of the
2221 -- normal expansion activities, and a number of special semantic
2222 -- rules apply (including the component type being any integer type)
2224 Elit := First_Literal (Enumtype);
2226 -- First the positional entries if any
2228 if Present (Expressions (Aggr)) then
2229 Expr := First (Expressions (Aggr));
2230 while Present (Expr) loop
2232 Error_Msg_N ("too many entries in aggregate", Expr);
2236 Val := Static_Integer (Expr);
2238 -- Err signals that we found some incorrect entries processing
2239 -- the list. The final checks for completeness and ordering are
2240 -- skipped in this case.
2242 if Val = No_Uint then
2244 elsif Val < Lo or else Hi < Val then
2245 Error_Msg_N ("value outside permitted range", Expr);
2249 Set_Enumeration_Rep (Elit, Val);
2250 Set_Enumeration_Rep_Expr (Elit, Expr);
2256 -- Now process the named entries if present
2258 if Present (Component_Associations (Aggr)) then
2259 Assoc := First (Component_Associations (Aggr));
2260 while Present (Assoc) loop
2261 Choice := First (Choices (Assoc));
2263 if Present (Next (Choice)) then
2265 ("multiple choice not allowed here", Next (Choice));
2269 if Nkind (Choice) = N_Others_Choice then
2270 Error_Msg_N ("others choice not allowed here", Choice);
2273 elsif Nkind (Choice) = N_Range then
2274 -- ??? should allow zero/one element range here
2275 Error_Msg_N ("range not allowed here", Choice);
2279 Analyze_And_Resolve (Choice, Enumtype);
2281 if Is_Entity_Name (Choice)
2282 and then Is_Type (Entity (Choice))
2284 Error_Msg_N ("subtype name not allowed here", Choice);
2286 -- ??? should allow static subtype with zero/one entry
2288 elsif Etype (Choice) = Base_Type (Enumtype) then
2289 if not Is_Static_Expression (Choice) then
2290 Flag_Non_Static_Expr
2291 ("non-static expression used for choice!", Choice);
2295 Elit := Expr_Value_E (Choice);
2297 if Present (Enumeration_Rep_Expr (Elit)) then
2298 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2300 ("representation for& previously given#",
2305 Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
2307 Expr := Expression (Assoc);
2308 Val := Static_Integer (Expr);
2310 if Val = No_Uint then
2313 elsif Val < Lo or else Hi < Val then
2314 Error_Msg_N ("value outside permitted range", Expr);
2318 Set_Enumeration_Rep (Elit, Val);
2327 -- Aggregate is fully processed. Now we check that a full set of
2328 -- representations was given, and that they are in range and in order.
2329 -- These checks are only done if no other errors occurred.
2335 Elit := First_Literal (Enumtype);
2336 while Present (Elit) loop
2337 if No (Enumeration_Rep_Expr (Elit)) then
2338 Error_Msg_NE ("missing representation for&!", N, Elit);
2341 Val := Enumeration_Rep (Elit);
2343 if Min = No_Uint then
2347 if Val /= No_Uint then
2348 if Max /= No_Uint and then Val <= Max then
2350 ("enumeration value for& not ordered!",
2351 Enumeration_Rep_Expr (Elit), Elit);
2354 Max_Node := Enumeration_Rep_Expr (Elit);
2358 -- If there is at least one literal whose representation is not
2359 -- equal to the Pos value, then note that this enumeration type
2360 -- has a non-standard representation.
2362 if Val /= Enumeration_Pos (Elit) then
2363 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2370 -- Now set proper size information
2373 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2376 if Has_Size_Clause (Enumtype) then
2378 -- All OK, if size is OK now
2380 if RM_Size (Enumtype) >= Minsize then
2384 -- Try if we can get by with biasing
2387 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2389 -- Error message if even biasing does not work
2391 if RM_Size (Enumtype) < Minsize then
2392 Error_Msg_Uint_1 := RM_Size (Enumtype);
2393 Error_Msg_Uint_2 := Max;
2395 ("previously given size (^) is too small "
2396 & "for this value (^)", Max_Node);
2398 -- If biasing worked, indicate that we now have biased rep
2402 (Enumtype, Size_Clause (Enumtype), "size clause");
2407 Set_RM_Size (Enumtype, Minsize);
2408 Set_Enum_Esize (Enumtype);
2411 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2412 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2413 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2417 -- We repeat the too late test in case it froze itself!
2419 if Rep_Item_Too_Late (Enumtype, N) then
2422 end Analyze_Enumeration_Representation_Clause;
2424 ----------------------------
2425 -- Analyze_Free_Statement --
2426 ----------------------------
2428 procedure Analyze_Free_Statement (N : Node_Id) is
2430 Analyze (Expression (N));
2431 end Analyze_Free_Statement;
2433 ---------------------------
2434 -- Analyze_Freeze_Entity --
2435 ---------------------------
2437 procedure Analyze_Freeze_Entity (N : Node_Id) is
2438 E : constant Entity_Id := Entity (N);
2441 -- Remember that we are processing a freezing entity. Required to
2442 -- ensure correct decoration of internal entities associated with
2443 -- interfaces (see New_Overloaded_Entity).
2445 Inside_Freezing_Actions := Inside_Freezing_Actions + 1;
2447 -- For tagged types covering interfaces add internal entities that link
2448 -- the primitives of the interfaces with the primitives that cover them.
2449 -- Note: These entities were originally generated only when generating
2450 -- code because their main purpose was to provide support to initialize
2451 -- the secondary dispatch tables. They are now generated also when
2452 -- compiling with no code generation to provide ASIS the relationship
2453 -- between interface primitives and tagged type primitives. They are
2454 -- also used to locate primitives covering interfaces when processing
2455 -- generics (see Derive_Subprograms).
2457 if Ada_Version >= Ada_05
2458 and then Ekind (E) = E_Record_Type
2459 and then Is_Tagged_Type (E)
2460 and then not Is_Interface (E)
2461 and then Has_Interfaces (E)
2463 -- This would be a good common place to call the routine that checks
2464 -- overriding of interface primitives (and thus factorize calls to
2465 -- Check_Abstract_Overriding located at different contexts in the
2466 -- compiler). However, this is not possible because it causes
2467 -- spurious errors in case of late overriding.
2469 Add_Internal_Interface_Entities (E);
2474 if Ekind (E) = E_Record_Type
2475 and then Is_CPP_Class (E)
2476 and then Is_Tagged_Type (E)
2477 and then Tagged_Type_Expansion
2478 and then Expander_Active
2480 if CPP_Num_Prims (E) = 0 then
2482 -- If the CPP type has user defined components then it must import
2483 -- primitives from C++. This is required because if the C++ class
2484 -- has no primitives then the C++ compiler does not added the _tag
2485 -- component to the type.
2487 pragma Assert (Chars (First_Entity (E)) = Name_uTag);
2489 if First_Entity (E) /= Last_Entity (E) then
2491 ("?'C'P'P type must import at least one primitive from C++",
2496 -- Check that all its primitives are abstract or imported from C++.
2497 -- Check also availability of the C++ constructor.
2500 Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
2502 Error_Reported : Boolean := False;
2506 Elmt := First_Elmt (Primitive_Operations (E));
2507 while Present (Elmt) loop
2508 Prim := Node (Elmt);
2510 if Comes_From_Source (Prim) then
2511 if Is_Abstract_Subprogram (Prim) then
2514 elsif not Is_Imported (Prim)
2515 or else Convention (Prim) /= Convention_CPP
2518 ("?primitives of 'C'P'P types must be imported from C++"
2519 & " or abstract", Prim);
2521 elsif not Has_Constructors
2522 and then not Error_Reported
2524 Error_Msg_Name_1 := Chars (E);
2526 ("?'C'P'P constructor required for type %", Prim);
2527 Error_Reported := True;
2536 Inside_Freezing_Actions := Inside_Freezing_Actions - 1;
2537 end Analyze_Freeze_Entity;
2539 ------------------------------------------
2540 -- Analyze_Record_Representation_Clause --
2541 ------------------------------------------
2543 -- Note: we check as much as we can here, but we can't do any checks
2544 -- based on the position values (e.g. overlap checks) until freeze time
2545 -- because especially in Ada 2005 (machine scalar mode), the processing
2546 -- for non-standard bit order can substantially change the positions.
2547 -- See procedure Check_Record_Representation_Clause (called from Freeze)
2548 -- for the remainder of this processing.
2550 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2551 Ident : constant Node_Id := Identifier (N);
2556 Hbit : Uint := Uint_0;
2560 Rectype : Entity_Id;
2562 CR_Pragma : Node_Id := Empty;
2563 -- Points to N_Pragma node if Complete_Representation pragma present
2566 if Ignore_Rep_Clauses then
2571 Rectype := Entity (Ident);
2573 if Rectype = Any_Type
2574 or else Rep_Item_Too_Early (Rectype, N)
2578 Rectype := Underlying_Type (Rectype);
2581 -- First some basic error checks
2583 if not Is_Record_Type (Rectype) then
2585 ("record type required, found}", Ident, First_Subtype (Rectype));
2588 elsif Scope (Rectype) /= Current_Scope then
2589 Error_Msg_N ("type must be declared in this scope", N);
2592 elsif not Is_First_Subtype (Rectype) then
2593 Error_Msg_N ("cannot give record rep clause for subtype", N);
2596 elsif Has_Record_Rep_Clause (Rectype) then
2597 Error_Msg_N ("duplicate record rep clause ignored", N);
2600 elsif Rep_Item_Too_Late (Rectype, N) then
2604 if Present (Mod_Clause (N)) then
2606 Loc : constant Source_Ptr := Sloc (N);
2607 M : constant Node_Id := Mod_Clause (N);
2608 P : constant List_Id := Pragmas_Before (M);
2612 pragma Warnings (Off, Mod_Val);
2615 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2617 if Warn_On_Obsolescent_Feature then
2619 ("mod clause is an obsolescent feature (RM J.8)?", N);
2621 ("\use alignment attribute definition clause instead?", N);
2628 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2629 -- the Mod clause into an alignment clause anyway, so that the
2630 -- back-end can compute and back-annotate properly the size and
2631 -- alignment of types that may include this record.
2633 -- This seems dubious, this destroys the source tree in a manner
2634 -- not detectable by ASIS ???
2636 if Operating_Mode = Check_Semantics
2640 Make_Attribute_Definition_Clause (Loc,
2641 Name => New_Reference_To (Base_Type (Rectype), Loc),
2642 Chars => Name_Alignment,
2643 Expression => Relocate_Node (Expression (M)));
2645 Set_From_At_Mod (AtM_Nod);
2646 Insert_After (N, AtM_Nod);
2647 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2648 Set_Mod_Clause (N, Empty);
2651 -- Get the alignment value to perform error checking
2653 Mod_Val := Get_Alignment_Value (Expression (M));
2658 -- For untagged types, clear any existing component clauses for the
2659 -- type. If the type is derived, this is what allows us to override
2660 -- a rep clause for the parent. For type extensions, the representation
2661 -- of the inherited components is inherited, so we want to keep previous
2662 -- component clauses for completeness.
2664 if not Is_Tagged_Type (Rectype) then
2665 Comp := First_Component_Or_Discriminant (Rectype);
2666 while Present (Comp) loop
2667 Set_Component_Clause (Comp, Empty);
2668 Next_Component_Or_Discriminant (Comp);
2672 -- All done if no component clauses
2674 CC := First (Component_Clauses (N));
2680 -- A representation like this applies to the base type
2682 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2683 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2684 Set_Has_Specified_Layout (Base_Type (Rectype));
2686 -- Process the component clauses
2688 while Present (CC) loop
2692 if Nkind (CC) = N_Pragma then
2695 -- The only pragma of interest is Complete_Representation
2697 if Pragma_Name (CC) = Name_Complete_Representation then
2701 -- Processing for real component clause
2704 Posit := Static_Integer (Position (CC));
2705 Fbit := Static_Integer (First_Bit (CC));
2706 Lbit := Static_Integer (Last_Bit (CC));
2709 and then Fbit /= No_Uint
2710 and then Lbit /= No_Uint
2714 ("position cannot be negative", Position (CC));
2718 ("first bit cannot be negative", First_Bit (CC));
2720 -- The Last_Bit specified in a component clause must not be
2721 -- less than the First_Bit minus one (RM-13.5.1(10)).
2723 elsif Lbit < Fbit - 1 then
2725 ("last bit cannot be less than first bit minus one",
2728 -- Values look OK, so find the corresponding record component
2729 -- Even though the syntax allows an attribute reference for
2730 -- implementation-defined components, GNAT does not allow the
2731 -- tag to get an explicit position.
2733 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2734 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2735 Error_Msg_N ("position of tag cannot be specified", CC);
2737 Error_Msg_N ("illegal component name", CC);
2741 Comp := First_Entity (Rectype);
2742 while Present (Comp) loop
2743 exit when Chars (Comp) = Chars (Component_Name (CC));
2749 -- Maybe component of base type that is absent from
2750 -- statically constrained first subtype.
2752 Comp := First_Entity (Base_Type (Rectype));
2753 while Present (Comp) loop
2754 exit when Chars (Comp) = Chars (Component_Name (CC));
2761 ("component clause is for non-existent field", CC);
2763 -- Ada 2012 (AI05-0026): Any name that denotes a
2764 -- discriminant of an object of an unchecked union type
2765 -- shall not occur within a record_representation_clause.
2767 -- The general restriction of using record rep clauses on
2768 -- Unchecked_Union types has now been lifted. Since it is
2769 -- possible to introduce a record rep clause which mentions
2770 -- the discriminant of an Unchecked_Union in non-Ada 2012
2771 -- code, this check is applied to all versions of the
2774 elsif Ekind (Comp) = E_Discriminant
2775 and then Is_Unchecked_Union (Rectype)
2778 ("cannot reference discriminant of Unchecked_Union",
2779 Component_Name (CC));
2781 elsif Present (Component_Clause (Comp)) then
2783 -- Diagnose duplicate rep clause, or check consistency
2784 -- if this is an inherited component. In a double fault,
2785 -- there may be a duplicate inconsistent clause for an
2786 -- inherited component.
2788 if Scope (Original_Record_Component (Comp)) = Rectype
2789 or else Parent (Component_Clause (Comp)) = N
2791 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2792 Error_Msg_N ("component clause previously given#", CC);
2796 Rep1 : constant Node_Id := Component_Clause (Comp);
2798 if Intval (Position (Rep1)) /=
2799 Intval (Position (CC))
2800 or else Intval (First_Bit (Rep1)) /=
2801 Intval (First_Bit (CC))
2802 or else Intval (Last_Bit (Rep1)) /=
2803 Intval (Last_Bit (CC))
2805 Error_Msg_N ("component clause inconsistent "
2806 & "with representation of ancestor", CC);
2807 elsif Warn_On_Redundant_Constructs then
2808 Error_Msg_N ("?redundant component clause "
2809 & "for inherited component!", CC);
2814 -- Normal case where this is the first component clause we
2815 -- have seen for this entity, so set it up properly.
2818 -- Make reference for field in record rep clause and set
2819 -- appropriate entity field in the field identifier.
2822 (Comp, Component_Name (CC), Set_Ref => False);
2823 Set_Entity (Component_Name (CC), Comp);
2825 -- Update Fbit and Lbit to the actual bit number
2827 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2828 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2830 if Has_Size_Clause (Rectype)
2831 and then Esize (Rectype) <= Lbit
2834 ("bit number out of range of specified size",
2837 Set_Component_Clause (Comp, CC);
2838 Set_Component_Bit_Offset (Comp, Fbit);
2839 Set_Esize (Comp, 1 + (Lbit - Fbit));
2840 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2841 Set_Normalized_Position (Comp, Fbit / SSU);
2843 if Warn_On_Overridden_Size
2844 and then Has_Size_Clause (Etype (Comp))
2845 and then RM_Size (Etype (Comp)) /= Esize (Comp)
2848 ("?component size overrides size clause for&",
2849 Component_Name (CC), Etype (Comp));
2852 -- This information is also set in the corresponding
2853 -- component of the base type, found by accessing the
2854 -- Original_Record_Component link if it is present.
2856 Ocomp := Original_Record_Component (Comp);
2863 (Component_Name (CC),
2869 (Comp, First_Node (CC), "component clause", Biased);
2871 if Present (Ocomp) then
2872 Set_Component_Clause (Ocomp, CC);
2873 Set_Component_Bit_Offset (Ocomp, Fbit);
2874 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2875 Set_Normalized_Position (Ocomp, Fbit / SSU);
2876 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2878 Set_Normalized_Position_Max
2879 (Ocomp, Normalized_Position (Ocomp));
2881 -- Note: we don't use Set_Biased here, because we
2882 -- already gave a warning above if needed, and we
2883 -- would get a duplicate for the same name here.
2885 Set_Has_Biased_Representation
2886 (Ocomp, Has_Biased_Representation (Comp));
2889 if Esize (Comp) < 0 then
2890 Error_Msg_N ("component size is negative", CC);
2901 -- Check missing components if Complete_Representation pragma appeared
2903 if Present (CR_Pragma) then
2904 Comp := First_Component_Or_Discriminant (Rectype);
2905 while Present (Comp) loop
2906 if No (Component_Clause (Comp)) then
2908 ("missing component clause for &", CR_Pragma, Comp);
2911 Next_Component_Or_Discriminant (Comp);
2914 -- If no Complete_Representation pragma, warn if missing components
2916 elsif Warn_On_Unrepped_Components then
2918 Num_Repped_Components : Nat := 0;
2919 Num_Unrepped_Components : Nat := 0;
2922 -- First count number of repped and unrepped components
2924 Comp := First_Component_Or_Discriminant (Rectype);
2925 while Present (Comp) loop
2926 if Present (Component_Clause (Comp)) then
2927 Num_Repped_Components := Num_Repped_Components + 1;
2929 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2932 Next_Component_Or_Discriminant (Comp);
2935 -- We are only interested in the case where there is at least one
2936 -- unrepped component, and at least half the components have rep
2937 -- clauses. We figure that if less than half have them, then the
2938 -- partial rep clause is really intentional. If the component
2939 -- type has no underlying type set at this point (as for a generic
2940 -- formal type), we don't know enough to give a warning on the
2943 if Num_Unrepped_Components > 0
2944 and then Num_Unrepped_Components < Num_Repped_Components
2946 Comp := First_Component_Or_Discriminant (Rectype);
2947 while Present (Comp) loop
2948 if No (Component_Clause (Comp))
2949 and then Comes_From_Source (Comp)
2950 and then Present (Underlying_Type (Etype (Comp)))
2951 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2952 or else Size_Known_At_Compile_Time
2953 (Underlying_Type (Etype (Comp))))
2954 and then not Has_Warnings_Off (Rectype)
2956 Error_Msg_Sloc := Sloc (Comp);
2958 ("?no component clause given for & declared #",
2962 Next_Component_Or_Discriminant (Comp);
2967 end Analyze_Record_Representation_Clause;
2969 -----------------------------------
2970 -- Check_Constant_Address_Clause --
2971 -----------------------------------
2973 procedure Check_Constant_Address_Clause
2977 procedure Check_At_Constant_Address (Nod : Node_Id);
2978 -- Checks that the given node N represents a name whose 'Address is
2979 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2980 -- address value is the same at the point of declaration of U_Ent and at
2981 -- the time of elaboration of the address clause.
2983 procedure Check_Expr_Constants (Nod : Node_Id);
2984 -- Checks that Nod meets the requirements for a constant address clause
2985 -- in the sense of the enclosing procedure.
2987 procedure Check_List_Constants (Lst : List_Id);
2988 -- Check that all elements of list Lst meet the requirements for a
2989 -- constant address clause in the sense of the enclosing procedure.
2991 -------------------------------
2992 -- Check_At_Constant_Address --
2993 -------------------------------
2995 procedure Check_At_Constant_Address (Nod : Node_Id) is
2997 if Is_Entity_Name (Nod) then
2998 if Present (Address_Clause (Entity ((Nod)))) then
3000 ("invalid address clause for initialized object &!",
3003 ("address for& cannot" &
3004 " depend on another address clause! (RM 13.1(22))!",
3007 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
3008 and then Sloc (U_Ent) < Sloc (Entity (Nod))
3011 ("invalid address clause for initialized object &!",
3013 Error_Msg_Node_2 := U_Ent;
3015 ("\& must be defined before & (RM 13.1(22))!",
3019 elsif Nkind (Nod) = N_Selected_Component then
3021 T : constant Entity_Id := Etype (Prefix (Nod));
3024 if (Is_Record_Type (T)
3025 and then Has_Discriminants (T))
3028 and then Is_Record_Type (Designated_Type (T))
3029 and then Has_Discriminants (Designated_Type (T)))
3032 ("invalid address clause for initialized object &!",
3035 ("\address cannot depend on component" &
3036 " of discriminated record (RM 13.1(22))!",
3039 Check_At_Constant_Address (Prefix (Nod));
3043 elsif Nkind (Nod) = N_Indexed_Component then
3044 Check_At_Constant_Address (Prefix (Nod));
3045 Check_List_Constants (Expressions (Nod));
3048 Check_Expr_Constants (Nod);
3050 end Check_At_Constant_Address;
3052 --------------------------
3053 -- Check_Expr_Constants --
3054 --------------------------
3056 procedure Check_Expr_Constants (Nod : Node_Id) is
3057 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
3058 Ent : Entity_Id := Empty;
3061 if Nkind (Nod) in N_Has_Etype
3062 and then Etype (Nod) = Any_Type
3068 when N_Empty | N_Error =>
3071 when N_Identifier | N_Expanded_Name =>
3072 Ent := Entity (Nod);
3074 -- We need to look at the original node if it is different
3075 -- from the node, since we may have rewritten things and
3076 -- substituted an identifier representing the rewrite.
3078 if Original_Node (Nod) /= Nod then
3079 Check_Expr_Constants (Original_Node (Nod));
3081 -- If the node is an object declaration without initial
3082 -- value, some code has been expanded, and the expression
3083 -- is not constant, even if the constituents might be
3084 -- acceptable, as in A'Address + offset.
3086 if Ekind (Ent) = E_Variable
3088 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3090 No (Expression (Declaration_Node (Ent)))
3093 ("invalid address clause for initialized object &!",
3096 -- If entity is constant, it may be the result of expanding
3097 -- a check. We must verify that its declaration appears
3098 -- before the object in question, else we also reject the
3101 elsif Ekind (Ent) = E_Constant
3102 and then In_Same_Source_Unit (Ent, U_Ent)
3103 and then Sloc (Ent) > Loc_U_Ent
3106 ("invalid address clause for initialized object &!",
3113 -- Otherwise look at the identifier and see if it is OK
3115 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
3116 or else Is_Type (Ent)
3121 Ekind (Ent) = E_Constant
3123 Ekind (Ent) = E_In_Parameter
3125 -- This is the case where we must have Ent defined before
3126 -- U_Ent. Clearly if they are in different units this
3127 -- requirement is met since the unit containing Ent is
3128 -- already processed.
3130 if not In_Same_Source_Unit (Ent, U_Ent) then
3133 -- Otherwise location of Ent must be before the location
3134 -- of U_Ent, that's what prior defined means.
3136 elsif Sloc (Ent) < Loc_U_Ent then
3141 ("invalid address clause for initialized object &!",
3143 Error_Msg_Node_2 := U_Ent;
3145 ("\& must be defined before & (RM 13.1(22))!",
3149 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3150 Check_Expr_Constants (Original_Node (Nod));
3154 ("invalid address clause for initialized object &!",
3157 if Comes_From_Source (Ent) then
3159 ("\reference to variable& not allowed"
3160 & " (RM 13.1(22))!", Nod, Ent);
3163 ("non-static expression not allowed"
3164 & " (RM 13.1(22))!", Nod);
3168 when N_Integer_Literal =>
3170 -- If this is a rewritten unchecked conversion, in a system
3171 -- where Address is an integer type, always use the base type
3172 -- for a literal value. This is user-friendly and prevents
3173 -- order-of-elaboration issues with instances of unchecked
3176 if Nkind (Original_Node (Nod)) = N_Function_Call then
3177 Set_Etype (Nod, Base_Type (Etype (Nod)));
3180 when N_Real_Literal |
3182 N_Character_Literal =>
3186 Check_Expr_Constants (Low_Bound (Nod));
3187 Check_Expr_Constants (High_Bound (Nod));
3189 when N_Explicit_Dereference =>
3190 Check_Expr_Constants (Prefix (Nod));
3192 when N_Indexed_Component =>
3193 Check_Expr_Constants (Prefix (Nod));
3194 Check_List_Constants (Expressions (Nod));
3197 Check_Expr_Constants (Prefix (Nod));
3198 Check_Expr_Constants (Discrete_Range (Nod));
3200 when N_Selected_Component =>
3201 Check_Expr_Constants (Prefix (Nod));
3203 when N_Attribute_Reference =>
3204 if Attribute_Name (Nod) = Name_Address
3206 Attribute_Name (Nod) = Name_Access
3208 Attribute_Name (Nod) = Name_Unchecked_Access
3210 Attribute_Name (Nod) = Name_Unrestricted_Access
3212 Check_At_Constant_Address (Prefix (Nod));
3215 Check_Expr_Constants (Prefix (Nod));
3216 Check_List_Constants (Expressions (Nod));
3220 Check_List_Constants (Component_Associations (Nod));
3221 Check_List_Constants (Expressions (Nod));
3223 when N_Component_Association =>
3224 Check_Expr_Constants (Expression (Nod));
3226 when N_Extension_Aggregate =>
3227 Check_Expr_Constants (Ancestor_Part (Nod));
3228 Check_List_Constants (Component_Associations (Nod));
3229 Check_List_Constants (Expressions (Nod));
3234 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3235 Check_Expr_Constants (Left_Opnd (Nod));
3236 Check_Expr_Constants (Right_Opnd (Nod));
3239 Check_Expr_Constants (Right_Opnd (Nod));
3241 when N_Type_Conversion |
3242 N_Qualified_Expression |
3244 Check_Expr_Constants (Expression (Nod));
3246 when N_Unchecked_Type_Conversion =>
3247 Check_Expr_Constants (Expression (Nod));
3249 -- If this is a rewritten unchecked conversion, subtypes in
3250 -- this node are those created within the instance. To avoid
3251 -- order of elaboration issues, replace them with their base
3252 -- types. Note that address clauses can cause order of
3253 -- elaboration problems because they are elaborated by the
3254 -- back-end at the point of definition, and may mention
3255 -- entities declared in between (as long as everything is
3256 -- static). It is user-friendly to allow unchecked conversions
3259 if Nkind (Original_Node (Nod)) = N_Function_Call then
3260 Set_Etype (Expression (Nod),
3261 Base_Type (Etype (Expression (Nod))));
3262 Set_Etype (Nod, Base_Type (Etype (Nod)));
3265 when N_Function_Call =>
3266 if not Is_Pure (Entity (Name (Nod))) then
3268 ("invalid address clause for initialized object &!",
3272 ("\function & is not pure (RM 13.1(22))!",
3273 Nod, Entity (Name (Nod)));
3276 Check_List_Constants (Parameter_Associations (Nod));
3279 when N_Parameter_Association =>
3280 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3284 ("invalid address clause for initialized object &!",
3287 ("\must be constant defined before& (RM 13.1(22))!",
3290 end Check_Expr_Constants;
3292 --------------------------
3293 -- Check_List_Constants --
3294 --------------------------
3296 procedure Check_List_Constants (Lst : List_Id) is
3300 if Present (Lst) then
3301 Nod1 := First (Lst);
3302 while Present (Nod1) loop
3303 Check_Expr_Constants (Nod1);
3307 end Check_List_Constants;
3309 -- Start of processing for Check_Constant_Address_Clause
3312 -- If rep_clauses are to be ignored, no need for legality checks. In
3313 -- particular, no need to pester user about rep clauses that violate
3314 -- the rule on constant addresses, given that these clauses will be
3315 -- removed by Freeze before they reach the back end.
3317 if not Ignore_Rep_Clauses then
3318 Check_Expr_Constants (Expr);
3320 end Check_Constant_Address_Clause;
3322 ----------------------------------------
3323 -- Check_Record_Representation_Clause --
3324 ----------------------------------------
3326 procedure Check_Record_Representation_Clause (N : Node_Id) is
3327 Loc : constant Source_Ptr := Sloc (N);
3328 Ident : constant Node_Id := Identifier (N);
3329 Rectype : Entity_Id;
3334 Hbit : Uint := Uint_0;
3338 Max_Bit_So_Far : Uint;
3339 -- Records the maximum bit position so far. If all field positions
3340 -- are monotonically increasing, then we can skip the circuit for
3341 -- checking for overlap, since no overlap is possible.
3343 Tagged_Parent : Entity_Id := Empty;
3344 -- This is set in the case of a derived tagged type for which we have
3345 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
3346 -- positioned by record representation clauses). In this case we must
3347 -- check for overlap between components of this tagged type, and the
3348 -- components of its parent. Tagged_Parent will point to this parent
3349 -- type. For all other cases Tagged_Parent is left set to Empty.
3351 Parent_Last_Bit : Uint;
3352 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
3353 -- last bit position for any field in the parent type. We only need to
3354 -- check overlap for fields starting below this point.
3356 Overlap_Check_Required : Boolean;
3357 -- Used to keep track of whether or not an overlap check is required
3359 Overlap_Detected : Boolean := False;
3360 -- Set True if an overlap is detected
3362 Ccount : Natural := 0;
3363 -- Number of component clauses in record rep clause
3365 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
3366 -- Given two entities for record components or discriminants, checks
3367 -- if they have overlapping component clauses and issues errors if so.
3369 procedure Find_Component;
3370 -- Finds component entity corresponding to current component clause (in
3371 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
3372 -- start/stop bits for the field. If there is no matching component or
3373 -- if the matching component does not have a component clause, then
3374 -- that's an error and Comp is set to Empty, but no error message is
3375 -- issued, since the message was already given. Comp is also set to
3376 -- Empty if the current "component clause" is in fact a pragma.
3378 -----------------------------
3379 -- Check_Component_Overlap --
3380 -----------------------------
3382 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
3383 CC1 : constant Node_Id := Component_Clause (C1_Ent);
3384 CC2 : constant Node_Id := Component_Clause (C2_Ent);
3387 if Present (CC1) and then Present (CC2) then
3389 -- Exclude odd case where we have two tag fields in the same
3390 -- record, both at location zero. This seems a bit strange, but
3391 -- it seems to happen in some circumstances, perhaps on an error.
3393 if Chars (C1_Ent) = Name_uTag
3395 Chars (C2_Ent) = Name_uTag
3400 -- Here we check if the two fields overlap
3403 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
3404 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
3405 E1 : constant Uint := S1 + Esize (C1_Ent);
3406 E2 : constant Uint := S2 + Esize (C2_Ent);
3409 if E2 <= S1 or else E1 <= S2 then
3412 Error_Msg_Node_2 := Component_Name (CC2);
3413 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
3414 Error_Msg_Node_1 := Component_Name (CC1);
3416 ("component& overlaps & #", Component_Name (CC1));
3417 Overlap_Detected := True;
3421 end Check_Component_Overlap;
3423 --------------------
3424 -- Find_Component --
3425 --------------------
3427 procedure Find_Component is
3429 procedure Search_Component (R : Entity_Id);
3430 -- Search components of R for a match. If found, Comp is set.
3432 ----------------------
3433 -- Search_Component --
3434 ----------------------
3436 procedure Search_Component (R : Entity_Id) is
3438 Comp := First_Component_Or_Discriminant (R);
3439 while Present (Comp) loop
3441 -- Ignore error of attribute name for component name (we
3442 -- already gave an error message for this, so no need to
3445 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
3448 exit when Chars (Comp) = Chars (Component_Name (CC));
3451 Next_Component_Or_Discriminant (Comp);
3453 end Search_Component;
3455 -- Start of processing for Find_Component
3458 -- Return with Comp set to Empty if we have a pragma
3460 if Nkind (CC) = N_Pragma then
3465 -- Search current record for matching component
3467 Search_Component (Rectype);
3469 -- If not found, maybe component of base type that is absent from
3470 -- statically constrained first subtype.
3473 Search_Component (Base_Type (Rectype));
3476 -- If no component, or the component does not reference the component
3477 -- clause in question, then there was some previous error for which
3478 -- we already gave a message, so just return with Comp Empty.
3481 or else Component_Clause (Comp) /= CC
3485 -- Normal case where we have a component clause
3488 Fbit := Component_Bit_Offset (Comp);
3489 Lbit := Fbit + Esize (Comp) - 1;
3493 -- Start of processing for Check_Record_Representation_Clause
3497 Rectype := Entity (Ident);
3499 if Rectype = Any_Type then
3502 Rectype := Underlying_Type (Rectype);
3505 -- See if we have a fully repped derived tagged type
3508 PS : constant Entity_Id := Parent_Subtype (Rectype);
3511 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
3512 Tagged_Parent := PS;
3514 -- Find maximum bit of any component of the parent type
3516 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
3517 Pcomp := First_Entity (Tagged_Parent);
3518 while Present (Pcomp) loop
3519 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
3520 if Component_Bit_Offset (Pcomp) /= No_Uint
3521 and then Known_Static_Esize (Pcomp)
3526 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
3529 Next_Entity (Pcomp);
3535 -- All done if no component clauses
3537 CC := First (Component_Clauses (N));
3543 -- If a tag is present, then create a component clause that places it
3544 -- at the start of the record (otherwise gigi may place it after other
3545 -- fields that have rep clauses).
3547 Fent := First_Entity (Rectype);
3549 if Nkind (Fent) = N_Defining_Identifier
3550 and then Chars (Fent) = Name_uTag
3552 Set_Component_Bit_Offset (Fent, Uint_0);
3553 Set_Normalized_Position (Fent, Uint_0);
3554 Set_Normalized_First_Bit (Fent, Uint_0);
3555 Set_Normalized_Position_Max (Fent, Uint_0);
3556 Init_Esize (Fent, System_Address_Size);
3558 Set_Component_Clause (Fent,
3559 Make_Component_Clause (Loc,
3561 Make_Identifier (Loc,
3562 Chars => Name_uTag),
3565 Make_Integer_Literal (Loc,
3569 Make_Integer_Literal (Loc,
3573 Make_Integer_Literal (Loc,
3574 UI_From_Int (System_Address_Size))));
3576 Ccount := Ccount + 1;
3579 Max_Bit_So_Far := Uint_Minus_1;
3580 Overlap_Check_Required := False;
3582 -- Process the component clauses
3584 while Present (CC) loop
3587 if Present (Comp) then
3588 Ccount := Ccount + 1;
3590 -- We need a full overlap check if record positions non-monotonic
3592 if Fbit <= Max_Bit_So_Far then
3593 Overlap_Check_Required := True;
3596 Max_Bit_So_Far := Lbit;
3598 -- Check bit position out of range of specified size
3600 if Has_Size_Clause (Rectype)
3601 and then Esize (Rectype) <= Lbit
3604 ("bit number out of range of specified size",
3607 -- Check for overlap with tag field
3610 if Is_Tagged_Type (Rectype)
3611 and then Fbit < System_Address_Size
3614 ("component overlaps tag field of&",
3615 Component_Name (CC), Rectype);
3616 Overlap_Detected := True;
3624 -- Check parent overlap if component might overlap parent field
3626 if Present (Tagged_Parent)
3627 and then Fbit <= Parent_Last_Bit
3629 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
3630 while Present (Pcomp) loop
3631 if not Is_Tag (Pcomp)
3632 and then Chars (Pcomp) /= Name_uParent
3634 Check_Component_Overlap (Comp, Pcomp);
3637 Next_Component_Or_Discriminant (Pcomp);
3645 -- Now that we have processed all the component clauses, check for
3646 -- overlap. We have to leave this till last, since the components can
3647 -- appear in any arbitrary order in the representation clause.
3649 -- We do not need this check if all specified ranges were monotonic,
3650 -- as recorded by Overlap_Check_Required being False at this stage.
3652 -- This first section checks if there are any overlapping entries at
3653 -- all. It does this by sorting all entries and then seeing if there are
3654 -- any overlaps. If there are none, then that is decisive, but if there
3655 -- are overlaps, they may still be OK (they may result from fields in
3656 -- different variants).
3658 if Overlap_Check_Required then
3659 Overlap_Check1 : declare
3661 OC_Fbit : array (0 .. Ccount) of Uint;
3662 -- First-bit values for component clauses, the value is the offset
3663 -- of the first bit of the field from start of record. The zero
3664 -- entry is for use in sorting.
3666 OC_Lbit : array (0 .. Ccount) of Uint;
3667 -- Last-bit values for component clauses, the value is the offset
3668 -- of the last bit of the field from start of record. The zero
3669 -- entry is for use in sorting.
3671 OC_Count : Natural := 0;
3672 -- Count of entries in OC_Fbit and OC_Lbit
3674 function OC_Lt (Op1, Op2 : Natural) return Boolean;
3675 -- Compare routine for Sort
3677 procedure OC_Move (From : Natural; To : Natural);
3678 -- Move routine for Sort
3680 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
3686 function OC_Lt (Op1, Op2 : Natural) return Boolean is
3688 return OC_Fbit (Op1) < OC_Fbit (Op2);
3695 procedure OC_Move (From : Natural; To : Natural) is
3697 OC_Fbit (To) := OC_Fbit (From);
3698 OC_Lbit (To) := OC_Lbit (From);
3701 -- Start of processing for Overlap_Check
3704 CC := First (Component_Clauses (N));
3705 while Present (CC) loop
3707 -- Exclude component clause already marked in error
3709 if not Error_Posted (CC) then
3712 if Present (Comp) then
3713 OC_Count := OC_Count + 1;
3714 OC_Fbit (OC_Count) := Fbit;
3715 OC_Lbit (OC_Count) := Lbit;
3722 Sorting.Sort (OC_Count);
3724 Overlap_Check_Required := False;
3725 for J in 1 .. OC_Count - 1 loop
3726 if OC_Lbit (J) >= OC_Fbit (J + 1) then
3727 Overlap_Check_Required := True;
3734 -- If Overlap_Check_Required is still True, then we have to do the full
3735 -- scale overlap check, since we have at least two fields that do
3736 -- overlap, and we need to know if that is OK since they are in
3737 -- different variant, or whether we have a definite problem.
3739 if Overlap_Check_Required then
3740 Overlap_Check2 : declare
3741 C1_Ent, C2_Ent : Entity_Id;
3742 -- Entities of components being checked for overlap
3745 -- Component_List node whose Component_Items are being checked
3748 -- Component declaration for component being checked
3751 C1_Ent := First_Entity (Base_Type (Rectype));
3753 -- Loop through all components in record. For each component check
3754 -- for overlap with any of the preceding elements on the component
3755 -- list containing the component and also, if the component is in
3756 -- a variant, check against components outside the case structure.
3757 -- This latter test is repeated recursively up the variant tree.
3759 Main_Component_Loop : while Present (C1_Ent) loop
3760 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
3761 goto Continue_Main_Component_Loop;
3764 -- Skip overlap check if entity has no declaration node. This
3765 -- happens with discriminants in constrained derived types.
3766 -- Possibly we are missing some checks as a result, but that
3767 -- does not seem terribly serious.
3769 if No (Declaration_Node (C1_Ent)) then
3770 goto Continue_Main_Component_Loop;
3773 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
3775 -- Loop through component lists that need checking. Check the
3776 -- current component list and all lists in variants above us.
3778 Component_List_Loop : loop
3780 -- If derived type definition, go to full declaration
3781 -- If at outer level, check discriminants if there are any.
3783 if Nkind (Clist) = N_Derived_Type_Definition then
3784 Clist := Parent (Clist);
3787 -- Outer level of record definition, check discriminants
3789 if Nkind_In (Clist, N_Full_Type_Declaration,
3790 N_Private_Type_Declaration)
3792 if Has_Discriminants (Defining_Identifier (Clist)) then
3794 First_Discriminant (Defining_Identifier (Clist));
3795 while Present (C2_Ent) loop
3796 exit when C1_Ent = C2_Ent;
3797 Check_Component_Overlap (C1_Ent, C2_Ent);
3798 Next_Discriminant (C2_Ent);
3802 -- Record extension case
3804 elsif Nkind (Clist) = N_Derived_Type_Definition then
3807 -- Otherwise check one component list
3810 Citem := First (Component_Items (Clist));
3811 while Present (Citem) loop
3812 if Nkind (Citem) = N_Component_Declaration then
3813 C2_Ent := Defining_Identifier (Citem);
3814 exit when C1_Ent = C2_Ent;
3815 Check_Component_Overlap (C1_Ent, C2_Ent);
3822 -- Check for variants above us (the parent of the Clist can
3823 -- be a variant, in which case its parent is a variant part,
3824 -- and the parent of the variant part is a component list
3825 -- whose components must all be checked against the current
3826 -- component for overlap).
3828 if Nkind (Parent (Clist)) = N_Variant then
3829 Clist := Parent (Parent (Parent (Clist)));
3831 -- Check for possible discriminant part in record, this
3832 -- is treated essentially as another level in the
3833 -- recursion. For this case the parent of the component
3834 -- list is the record definition, and its parent is the
3835 -- full type declaration containing the discriminant
3838 elsif Nkind (Parent (Clist)) = N_Record_Definition then
3839 Clist := Parent (Parent ((Clist)));
3841 -- If neither of these two cases, we are at the top of
3845 exit Component_List_Loop;
3847 end loop Component_List_Loop;
3849 <<Continue_Main_Component_Loop>>
3850 Next_Entity (C1_Ent);
3852 end loop Main_Component_Loop;
3856 -- The following circuit deals with warning on record holes (gaps). We
3857 -- skip this check if overlap was detected, since it makes sense for the
3858 -- programmer to fix this illegality before worrying about warnings.
3860 if not Overlap_Detected and Warn_On_Record_Holes then
3861 Record_Hole_Check : declare
3862 Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype));
3863 -- Full declaration of record type
3865 procedure Check_Component_List
3869 -- Check component list CL for holes. The starting bit should be
3870 -- Sbit. which is zero for the main record component list and set
3871 -- appropriately for recursive calls for variants. DS is set to
3872 -- a list of discriminant specifications to be included in the
3873 -- consideration of components. It is No_List if none to consider.
3875 --------------------------
3876 -- Check_Component_List --
3877 --------------------------
3879 procedure Check_Component_List
3887 Compl := Integer (List_Length (Component_Items (CL)));
3889 if DS /= No_List then
3890 Compl := Compl + Integer (List_Length (DS));
3894 Comps : array (Natural range 0 .. Compl) of Entity_Id;
3895 -- Gather components (zero entry is for sort routine)
3897 Ncomps : Natural := 0;
3898 -- Number of entries stored in Comps (starting at Comps (1))
3901 -- One component item or discriminant specification
3904 -- Starting bit for next component
3912 function Lt (Op1, Op2 : Natural) return Boolean;
3913 -- Compare routine for Sort
3915 procedure Move (From : Natural; To : Natural);
3916 -- Move routine for Sort
3918 package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
3924 function Lt (Op1, Op2 : Natural) return Boolean is
3926 return Component_Bit_Offset (Comps (Op1))
3928 Component_Bit_Offset (Comps (Op2));
3935 procedure Move (From : Natural; To : Natural) is
3937 Comps (To) := Comps (From);
3941 -- Gather discriminants into Comp
3943 if DS /= No_List then
3944 Citem := First (DS);
3945 while Present (Citem) loop
3946 if Nkind (Citem) = N_Discriminant_Specification then
3948 Ent : constant Entity_Id :=
3949 Defining_Identifier (Citem);
3951 if Ekind (Ent) = E_Discriminant then
3952 Ncomps := Ncomps + 1;
3953 Comps (Ncomps) := Ent;
3962 -- Gather component entities into Comp
3964 Citem := First (Component_Items (CL));
3965 while Present (Citem) loop
3966 if Nkind (Citem) = N_Component_Declaration then
3967 Ncomps := Ncomps + 1;
3968 Comps (Ncomps) := Defining_Identifier (Citem);
3974 -- Now sort the component entities based on the first bit.
3975 -- Note we already know there are no overlapping components.
3977 Sorting.Sort (Ncomps);
3979 -- Loop through entries checking for holes
3982 for J in 1 .. Ncomps loop
3984 Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
3986 if Error_Msg_Uint_1 > 0 then
3988 ("?^-bit gap before component&",
3989 Component_Name (Component_Clause (CEnt)), CEnt);
3992 Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
3995 -- Process variant parts recursively if present
3997 if Present (Variant_Part (CL)) then
3998 Variant := First (Variants (Variant_Part (CL)));
3999 while Present (Variant) loop
4000 Check_Component_List
4001 (Component_List (Variant), Nbit, No_List);
4006 end Check_Component_List;
4008 -- Start of processing for Record_Hole_Check
4015 if Is_Tagged_Type (Rectype) then
4016 Sbit := UI_From_Int (System_Address_Size);
4021 if Nkind (Decl) = N_Full_Type_Declaration
4022 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
4024 Check_Component_List
4025 (Component_List (Type_Definition (Decl)),
4027 Discriminant_Specifications (Decl));
4030 end Record_Hole_Check;
4033 -- For records that have component clauses for all components, and whose
4034 -- size is less than or equal to 32, we need to know the size in the
4035 -- front end to activate possible packed array processing where the
4036 -- component type is a record.
4038 -- At this stage Hbit + 1 represents the first unused bit from all the
4039 -- component clauses processed, so if the component clauses are
4040 -- complete, then this is the length of the record.
4042 -- For records longer than System.Storage_Unit, and for those where not
4043 -- all components have component clauses, the back end determines the
4044 -- length (it may for example be appropriate to round up the size
4045 -- to some convenient boundary, based on alignment considerations, etc).
4047 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
4049 -- Nothing to do if at least one component has no component clause
4051 Comp := First_Component_Or_Discriminant (Rectype);
4052 while Present (Comp) loop
4053 exit when No (Component_Clause (Comp));
4054 Next_Component_Or_Discriminant (Comp);
4057 -- If we fall out of loop, all components have component clauses
4058 -- and so we can set the size to the maximum value.
4061 Set_RM_Size (Rectype, Hbit + 1);
4064 end Check_Record_Representation_Clause;
4070 procedure Check_Size
4074 Biased : out Boolean)
4076 UT : constant Entity_Id := Underlying_Type (T);
4082 -- Dismiss cases for generic types or types with previous errors
4085 or else UT = Any_Type
4086 or else Is_Generic_Type (UT)
4087 or else Is_Generic_Type (Root_Type (UT))
4091 -- Check case of bit packed array
4093 elsif Is_Array_Type (UT)
4094 and then Known_Static_Component_Size (UT)
4095 and then Is_Bit_Packed_Array (UT)
4103 Asiz := Component_Size (UT);
4104 Indx := First_Index (UT);
4106 Ityp := Etype (Indx);
4108 -- If non-static bound, then we are not in the business of
4109 -- trying to check the length, and indeed an error will be
4110 -- issued elsewhere, since sizes of non-static array types
4111 -- cannot be set implicitly or explicitly.
4113 if not Is_Static_Subtype (Ityp) then
4117 -- Otherwise accumulate next dimension
4119 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
4120 Expr_Value (Type_Low_Bound (Ityp)) +
4124 exit when No (Indx);
4130 Error_Msg_Uint_1 := Asiz;
4132 ("size for& too small, minimum allowed is ^", N, T);
4133 Set_Esize (T, Asiz);
4134 Set_RM_Size (T, Asiz);
4138 -- All other composite types are ignored
4140 elsif Is_Composite_Type (UT) then
4143 -- For fixed-point types, don't check minimum if type is not frozen,
4144 -- since we don't know all the characteristics of the type that can
4145 -- affect the size (e.g. a specified small) till freeze time.
4147 elsif Is_Fixed_Point_Type (UT)
4148 and then not Is_Frozen (UT)
4152 -- Cases for which a minimum check is required
4155 -- Ignore if specified size is correct for the type
4157 if Known_Esize (UT) and then Siz = Esize (UT) then
4161 -- Otherwise get minimum size
4163 M := UI_From_Int (Minimum_Size (UT));
4167 -- Size is less than minimum size, but one possibility remains
4168 -- that we can manage with the new size if we bias the type.
4170 M := UI_From_Int (Minimum_Size (UT, Biased => True));
4173 Error_Msg_Uint_1 := M;
4175 ("size for& too small, minimum allowed is ^", N, T);
4185 -------------------------
4186 -- Get_Alignment_Value --
4187 -------------------------
4189 function Get_Alignment_Value (Expr : Node_Id) return Uint is
4190 Align : constant Uint := Static_Integer (Expr);
4193 if Align = No_Uint then
4196 elsif Align <= 0 then
4197 Error_Msg_N ("alignment value must be positive", Expr);
4201 for J in Int range 0 .. 64 loop
4203 M : constant Uint := Uint_2 ** J;
4206 exit when M = Align;
4210 ("alignment value must be power of 2", Expr);
4218 end Get_Alignment_Value;
4224 procedure Initialize is
4226 Unchecked_Conversions.Init;
4229 -------------------------
4230 -- Is_Operational_Item --
4231 -------------------------
4233 function Is_Operational_Item (N : Node_Id) return Boolean is
4235 if Nkind (N) /= N_Attribute_Definition_Clause then
4239 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
4241 return Id = Attribute_Input
4242 or else Id = Attribute_Output
4243 or else Id = Attribute_Read
4244 or else Id = Attribute_Write
4245 or else Id = Attribute_External_Tag;
4248 end Is_Operational_Item;
4254 function Minimum_Size
4256 Biased : Boolean := False) return Nat
4258 Lo : Uint := No_Uint;
4259 Hi : Uint := No_Uint;
4260 LoR : Ureal := No_Ureal;
4261 HiR : Ureal := No_Ureal;
4262 LoSet : Boolean := False;
4263 HiSet : Boolean := False;
4267 R_Typ : constant Entity_Id := Root_Type (T);
4270 -- If bad type, return 0
4272 if T = Any_Type then
4275 -- For generic types, just return zero. There cannot be any legitimate
4276 -- need to know such a size, but this routine may be called with a
4277 -- generic type as part of normal processing.
4279 elsif Is_Generic_Type (R_Typ)
4280 or else R_Typ = Any_Type
4284 -- Access types. Normally an access type cannot have a size smaller
4285 -- than the size of System.Address. The exception is on VMS, where
4286 -- we have short and long addresses, and it is possible for an access
4287 -- type to have a short address size (and thus be less than the size
4288 -- of System.Address itself). We simply skip the check for VMS, and
4289 -- leave it to the back end to do the check.
4291 elsif Is_Access_Type (T) then
4292 if OpenVMS_On_Target then
4295 return System_Address_Size;
4298 -- Floating-point types
4300 elsif Is_Floating_Point_Type (T) then
4301 return UI_To_Int (Esize (R_Typ));
4305 elsif Is_Discrete_Type (T) then
4307 -- The following loop is looking for the nearest compile time known
4308 -- bounds following the ancestor subtype chain. The idea is to find
4309 -- the most restrictive known bounds information.
4313 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4318 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
4319 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
4326 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
4327 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
4333 Ancest := Ancestor_Subtype (Ancest);
4336 Ancest := Base_Type (T);
4338 if Is_Generic_Type (Ancest) then
4344 -- Fixed-point types. We can't simply use Expr_Value to get the
4345 -- Corresponding_Integer_Value values of the bounds, since these do not
4346 -- get set till the type is frozen, and this routine can be called
4347 -- before the type is frozen. Similarly the test for bounds being static
4348 -- needs to include the case where we have unanalyzed real literals for
4351 elsif Is_Fixed_Point_Type (T) then
4353 -- The following loop is looking for the nearest compile time known
4354 -- bounds following the ancestor subtype chain. The idea is to find
4355 -- the most restrictive known bounds information.
4359 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4363 -- Note: In the following two tests for LoSet and HiSet, it may
4364 -- seem redundant to test for N_Real_Literal here since normally
4365 -- one would assume that the test for the value being known at
4366 -- compile time includes this case. However, there is a glitch.
4367 -- If the real literal comes from folding a non-static expression,
4368 -- then we don't consider any non- static expression to be known
4369 -- at compile time if we are in configurable run time mode (needed
4370 -- in some cases to give a clearer definition of what is and what
4371 -- is not accepted). So the test is indeed needed. Without it, we
4372 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
4375 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
4376 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
4378 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
4385 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
4386 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
4388 HiR := Expr_Value_R (Type_High_Bound (Ancest));
4394 Ancest := Ancestor_Subtype (Ancest);
4397 Ancest := Base_Type (T);
4399 if Is_Generic_Type (Ancest) then
4405 Lo := UR_To_Uint (LoR / Small_Value (T));
4406 Hi := UR_To_Uint (HiR / Small_Value (T));
4408 -- No other types allowed
4411 raise Program_Error;
4414 -- Fall through with Hi and Lo set. Deal with biased case
4417 and then not Is_Fixed_Point_Type (T)
4418 and then not (Is_Enumeration_Type (T)
4419 and then Has_Non_Standard_Rep (T)))
4420 or else Has_Biased_Representation (T)
4426 -- Signed case. Note that we consider types like range 1 .. -1 to be
4427 -- signed for the purpose of computing the size, since the bounds have
4428 -- to be accommodated in the base type.
4430 if Lo < 0 or else Hi < 0 then
4434 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
4435 -- Note that we accommodate the case where the bounds cross. This
4436 -- can happen either because of the way the bounds are declared
4437 -- or because of the algorithm in Freeze_Fixed_Point_Type.
4451 -- If both bounds are positive, make sure that both are represen-
4452 -- table in the case where the bounds are crossed. This can happen
4453 -- either because of the way the bounds are declared, or because of
4454 -- the algorithm in Freeze_Fixed_Point_Type.
4460 -- S = size, (can accommodate 0 .. (2**size - 1))
4463 while Hi >= Uint_2 ** S loop
4471 ---------------------------
4472 -- New_Stream_Subprogram --
4473 ---------------------------
4475 procedure New_Stream_Subprogram
4479 Nam : TSS_Name_Type)
4481 Loc : constant Source_Ptr := Sloc (N);
4482 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
4483 Subp_Id : Entity_Id;
4484 Subp_Decl : Node_Id;
4488 Defer_Declaration : constant Boolean :=
4489 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
4490 -- For a tagged type, there is a declaration for each stream attribute
4491 -- at the freeze point, and we must generate only a completion of this
4492 -- declaration. We do the same for private types, because the full view
4493 -- might be tagged. Otherwise we generate a declaration at the point of
4494 -- the attribute definition clause.
4496 function Build_Spec return Node_Id;
4497 -- Used for declaration and renaming declaration, so that this is
4498 -- treated as a renaming_as_body.
4504 function Build_Spec return Node_Id is
4505 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
4508 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
4511 Subp_Id := Make_Defining_Identifier (Loc, Sname);
4513 -- S : access Root_Stream_Type'Class
4515 Formals := New_List (
4516 Make_Parameter_Specification (Loc,
4517 Defining_Identifier =>
4518 Make_Defining_Identifier (Loc, Name_S),
4520 Make_Access_Definition (Loc,
4523 Designated_Type (Etype (F)), Loc))));
4525 if Nam = TSS_Stream_Input then
4526 Spec := Make_Function_Specification (Loc,
4527 Defining_Unit_Name => Subp_Id,
4528 Parameter_Specifications => Formals,
4529 Result_Definition => T_Ref);
4534 Make_Parameter_Specification (Loc,
4535 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
4536 Out_Present => Out_P,
4537 Parameter_Type => T_Ref));
4540 Make_Procedure_Specification (Loc,
4541 Defining_Unit_Name => Subp_Id,
4542 Parameter_Specifications => Formals);
4548 -- Start of processing for New_Stream_Subprogram
4551 F := First_Formal (Subp);
4553 if Ekind (Subp) = E_Procedure then
4554 Etyp := Etype (Next_Formal (F));
4556 Etyp := Etype (Subp);
4559 -- Prepare subprogram declaration and insert it as an action on the
4560 -- clause node. The visibility for this entity is used to test for
4561 -- visibility of the attribute definition clause (in the sense of
4562 -- 8.3(23) as amended by AI-195).
4564 if not Defer_Declaration then
4566 Make_Subprogram_Declaration (Loc,
4567 Specification => Build_Spec);
4569 -- For a tagged type, there is always a visible declaration for each
4570 -- stream TSS (it is a predefined primitive operation), and the
4571 -- completion of this declaration occurs at the freeze point, which is
4572 -- not always visible at places where the attribute definition clause is
4573 -- visible. So, we create a dummy entity here for the purpose of
4574 -- tracking the visibility of the attribute definition clause itself.
4578 Make_Defining_Identifier (Loc,
4579 Chars => New_External_Name (Sname, 'V'));
4581 Make_Object_Declaration (Loc,
4582 Defining_Identifier => Subp_Id,
4583 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
4586 Insert_Action (N, Subp_Decl);
4587 Set_Entity (N, Subp_Id);
4590 Make_Subprogram_Renaming_Declaration (Loc,
4591 Specification => Build_Spec,
4592 Name => New_Reference_To (Subp, Loc));
4594 if Defer_Declaration then
4595 Set_TSS (Base_Type (Ent), Subp_Id);
4597 Insert_Action (N, Subp_Decl);
4598 Copy_TSS (Subp_Id, Base_Type (Ent));
4600 end New_Stream_Subprogram;
4602 ------------------------
4603 -- Rep_Item_Too_Early --
4604 ------------------------
4606 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
4608 -- Cannot apply non-operational rep items to generic types
4610 if Is_Operational_Item (N) then
4614 and then Is_Generic_Type (Root_Type (T))
4616 Error_Msg_N ("representation item not allowed for generic type", N);
4620 -- Otherwise check for incomplete type
4622 if Is_Incomplete_Or_Private_Type (T)
4623 and then No (Underlying_Type (T))
4626 ("representation item must be after full type declaration", N);
4629 -- If the type has incomplete components, a representation clause is
4630 -- illegal but stream attributes and Convention pragmas are correct.
4632 elsif Has_Private_Component (T) then
4633 if Nkind (N) = N_Pragma then
4637 ("representation item must appear after type is fully defined",
4644 end Rep_Item_Too_Early;
4646 -----------------------
4647 -- Rep_Item_Too_Late --
4648 -----------------------
4650 function Rep_Item_Too_Late
4653 FOnly : Boolean := False) return Boolean
4656 Parent_Type : Entity_Id;
4659 -- Output the too late message. Note that this is not considered a
4660 -- serious error, since the effect is simply that we ignore the
4661 -- representation clause in this case.
4667 procedure Too_Late is
4669 Error_Msg_N ("|representation item appears too late!", N);
4672 -- Start of processing for Rep_Item_Too_Late
4675 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
4676 -- types, which may be frozen if they appear in a representation clause
4677 -- for a local type.
4680 and then not From_With_Type (T)
4683 S := First_Subtype (T);
4685 if Present (Freeze_Node (S)) then
4687 ("?no more representation items for }", Freeze_Node (S), S);
4692 -- Check for case of non-tagged derived type whose parent either has
4693 -- primitive operations, or is a by reference type (RM 13.1(10)).
4697 and then Is_Derived_Type (T)
4698 and then not Is_Tagged_Type (T)
4700 Parent_Type := Etype (Base_Type (T));
4702 if Has_Primitive_Operations (Parent_Type) then
4705 ("primitive operations already defined for&!", N, Parent_Type);
4708 elsif Is_By_Reference_Type (Parent_Type) then
4711 ("parent type & is a by reference type!", N, Parent_Type);
4716 -- No error, link item into head of chain of rep items for the entity,
4717 -- but avoid chaining if we have an overloadable entity, and the pragma
4718 -- is one that can apply to multiple overloaded entities.
4720 if Is_Overloadable (T)
4721 and then Nkind (N) = N_Pragma
4724 Pname : constant Name_Id := Pragma_Name (N);
4726 if Pname = Name_Convention or else
4727 Pname = Name_Import or else
4728 Pname = Name_Export or else
4729 Pname = Name_External or else
4730 Pname = Name_Interface
4737 Record_Rep_Item (T, N);
4739 end Rep_Item_Too_Late;
4741 -------------------------
4742 -- Same_Representation --
4743 -------------------------
4745 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
4746 T1 : constant Entity_Id := Underlying_Type (Typ1);
4747 T2 : constant Entity_Id := Underlying_Type (Typ2);
4750 -- A quick check, if base types are the same, then we definitely have
4751 -- the same representation, because the subtype specific representation
4752 -- attributes (Size and Alignment) do not affect representation from
4753 -- the point of view of this test.
4755 if Base_Type (T1) = Base_Type (T2) then
4758 elsif Is_Private_Type (Base_Type (T2))
4759 and then Base_Type (T1) = Full_View (Base_Type (T2))
4764 -- Tagged types never have differing representations
4766 if Is_Tagged_Type (T1) then
4770 -- Representations are definitely different if conventions differ
4772 if Convention (T1) /= Convention (T2) then
4776 -- Representations are different if component alignments differ
4778 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4780 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4781 and then Component_Alignment (T1) /= Component_Alignment (T2)
4786 -- For arrays, the only real issue is component size. If we know the
4787 -- component size for both arrays, and it is the same, then that's
4788 -- good enough to know we don't have a change of representation.
4790 if Is_Array_Type (T1) then
4791 if Known_Component_Size (T1)
4792 and then Known_Component_Size (T2)
4793 and then Component_Size (T1) = Component_Size (T2)
4799 -- Types definitely have same representation if neither has non-standard
4800 -- representation since default representations are always consistent.
4801 -- If only one has non-standard representation, and the other does not,
4802 -- then we consider that they do not have the same representation. They
4803 -- might, but there is no way of telling early enough.
4805 if Has_Non_Standard_Rep (T1) then
4806 if not Has_Non_Standard_Rep (T2) then
4810 return not Has_Non_Standard_Rep (T2);
4813 -- Here the two types both have non-standard representation, and we need
4814 -- to determine if they have the same non-standard representation.
4816 -- For arrays, we simply need to test if the component sizes are the
4817 -- same. Pragma Pack is reflected in modified component sizes, so this
4818 -- check also deals with pragma Pack.
4820 if Is_Array_Type (T1) then
4821 return Component_Size (T1) = Component_Size (T2);
4823 -- Tagged types always have the same representation, because it is not
4824 -- possible to specify different representations for common fields.
4826 elsif Is_Tagged_Type (T1) then
4829 -- Case of record types
4831 elsif Is_Record_Type (T1) then
4833 -- Packed status must conform
4835 if Is_Packed (T1) /= Is_Packed (T2) then
4838 -- Otherwise we must check components. Typ2 maybe a constrained
4839 -- subtype with fewer components, so we compare the components
4840 -- of the base types.
4843 Record_Case : declare
4844 CD1, CD2 : Entity_Id;
4846 function Same_Rep return Boolean;
4847 -- CD1 and CD2 are either components or discriminants. This
4848 -- function tests whether the two have the same representation
4854 function Same_Rep return Boolean is
4856 if No (Component_Clause (CD1)) then
4857 return No (Component_Clause (CD2));
4861 Present (Component_Clause (CD2))
4863 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4865 Esize (CD1) = Esize (CD2);
4869 -- Start of processing for Record_Case
4872 if Has_Discriminants (T1) then
4873 CD1 := First_Discriminant (T1);
4874 CD2 := First_Discriminant (T2);
4876 -- The number of discriminants may be different if the
4877 -- derived type has fewer (constrained by values). The
4878 -- invisible discriminants retain the representation of
4879 -- the original, so the discrepancy does not per se
4880 -- indicate a different representation.
4883 and then Present (CD2)
4885 if not Same_Rep then
4888 Next_Discriminant (CD1);
4889 Next_Discriminant (CD2);
4894 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4895 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4897 while Present (CD1) loop
4898 if not Same_Rep then
4901 Next_Component (CD1);
4902 Next_Component (CD2);
4910 -- For enumeration types, we must check each literal to see if the
4911 -- representation is the same. Note that we do not permit enumeration
4912 -- representation clauses for Character and Wide_Character, so these
4913 -- cases were already dealt with.
4915 elsif Is_Enumeration_Type (T1) then
4916 Enumeration_Case : declare
4920 L1 := First_Literal (T1);
4921 L2 := First_Literal (T2);
4923 while Present (L1) loop
4924 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4934 end Enumeration_Case;
4936 -- Any other types have the same representation for these purposes
4941 end Same_Representation;
4947 procedure Set_Biased
4951 Biased : Boolean := True)
4955 Set_Has_Biased_Representation (E);
4957 if Warn_On_Biased_Representation then
4959 ("?" & Msg & " forces biased representation for&", N, E);
4964 --------------------
4965 -- Set_Enum_Esize --
4966 --------------------
4968 procedure Set_Enum_Esize (T : Entity_Id) is
4976 -- Find the minimum standard size (8,16,32,64) that fits
4978 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4979 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4982 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4983 Sz := Standard_Character_Size; -- May be > 8 on some targets
4985 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4988 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4991 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4996 if Hi < Uint_2**08 then
4997 Sz := Standard_Character_Size; -- May be > 8 on some targets
4999 elsif Hi < Uint_2**16 then
5002 elsif Hi < Uint_2**32 then
5005 else pragma Assert (Hi < Uint_2**63);
5010 -- That minimum is the proper size unless we have a foreign convention
5011 -- and the size required is 32 or less, in which case we bump the size
5012 -- up to 32. This is required for C and C++ and seems reasonable for
5013 -- all other foreign conventions.
5015 if Has_Foreign_Convention (T)
5016 and then Esize (T) < Standard_Integer_Size
5018 Init_Esize (T, Standard_Integer_Size);
5024 ------------------------------
5025 -- Validate_Address_Clauses --
5026 ------------------------------
5028 procedure Validate_Address_Clauses is
5030 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
5032 ACCR : Address_Clause_Check_Record
5033 renames Address_Clause_Checks.Table (J);
5044 -- Skip processing of this entry if warning already posted
5046 if not Address_Warning_Posted (ACCR.N) then
5048 Expr := Original_Node (Expression (ACCR.N));
5052 X_Alignment := Alignment (ACCR.X);
5053 Y_Alignment := Alignment (ACCR.Y);
5055 -- Similarly obtain sizes
5057 X_Size := Esize (ACCR.X);
5058 Y_Size := Esize (ACCR.Y);
5060 -- Check for large object overlaying smaller one
5063 and then X_Size > Uint_0
5064 and then X_Size > Y_Size
5067 ("?& overlays smaller object", ACCR.N, ACCR.X);
5069 ("\?program execution may be erroneous", ACCR.N);
5070 Error_Msg_Uint_1 := X_Size;
5072 ("\?size of & is ^", ACCR.N, ACCR.X);
5073 Error_Msg_Uint_1 := Y_Size;
5075 ("\?size of & is ^", ACCR.N, ACCR.Y);
5077 -- Check for inadequate alignment, both of the base object
5078 -- and of the offset, if any.
5080 -- Note: we do not check the alignment if we gave a size
5081 -- warning, since it would likely be redundant.
5083 elsif Y_Alignment /= Uint_0
5084 and then (Y_Alignment < X_Alignment
5087 Nkind (Expr) = N_Attribute_Reference
5089 Attribute_Name (Expr) = Name_Address
5091 Has_Compatible_Alignment
5092 (ACCR.X, Prefix (Expr))
5093 /= Known_Compatible))
5096 ("?specified address for& may be inconsistent "
5100 ("\?program execution may be erroneous (RM 13.3(27))",
5102 Error_Msg_Uint_1 := X_Alignment;
5104 ("\?alignment of & is ^",
5106 Error_Msg_Uint_1 := Y_Alignment;
5108 ("\?alignment of & is ^",
5110 if Y_Alignment >= X_Alignment then
5112 ("\?but offset is not multiple of alignment",
5119 end Validate_Address_Clauses;
5121 -----------------------------------
5122 -- Validate_Unchecked_Conversion --
5123 -----------------------------------
5125 procedure Validate_Unchecked_Conversion
5127 Act_Unit : Entity_Id)
5134 -- Obtain source and target types. Note that we call Ancestor_Subtype
5135 -- here because the processing for generic instantiation always makes
5136 -- subtypes, and we want the original frozen actual types.
5138 -- If we are dealing with private types, then do the check on their
5139 -- fully declared counterparts if the full declarations have been
5140 -- encountered (they don't have to be visible, but they must exist!)
5142 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
5144 if Is_Private_Type (Source)
5145 and then Present (Underlying_Type (Source))
5147 Source := Underlying_Type (Source);
5150 Target := Ancestor_Subtype (Etype (Act_Unit));
5152 -- If either type is generic, the instantiation happens within a generic
5153 -- unit, and there is nothing to check. The proper check
5154 -- will happen when the enclosing generic is instantiated.
5156 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
5160 if Is_Private_Type (Target)
5161 and then Present (Underlying_Type (Target))
5163 Target := Underlying_Type (Target);
5166 -- Source may be unconstrained array, but not target
5168 if Is_Array_Type (Target)
5169 and then not Is_Constrained (Target)
5172 ("unchecked conversion to unconstrained array not allowed", N);
5176 -- Warn if conversion between two different convention pointers
5178 if Is_Access_Type (Target)
5179 and then Is_Access_Type (Source)
5180 and then Convention (Target) /= Convention (Source)
5181 and then Warn_On_Unchecked_Conversion
5183 -- Give warnings for subprogram pointers only on most targets. The
5184 -- exception is VMS, where data pointers can have different lengths
5185 -- depending on the pointer convention.
5187 if Is_Access_Subprogram_Type (Target)
5188 or else Is_Access_Subprogram_Type (Source)
5189 or else OpenVMS_On_Target
5192 ("?conversion between pointers with different conventions!", N);
5196 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
5197 -- warning when compiling GNAT-related sources.
5199 if Warn_On_Unchecked_Conversion
5200 and then not In_Predefined_Unit (N)
5201 and then RTU_Loaded (Ada_Calendar)
5203 (Chars (Source) = Name_Time
5205 Chars (Target) = Name_Time)
5207 -- If Ada.Calendar is loaded and the name of one of the operands is
5208 -- Time, there is a good chance that this is Ada.Calendar.Time.
5211 Calendar_Time : constant Entity_Id :=
5212 Full_View (RTE (RO_CA_Time));
5214 pragma Assert (Present (Calendar_Time));
5216 if Source = Calendar_Time
5217 or else Target = Calendar_Time
5220 ("?representation of 'Time values may change between " &
5221 "'G'N'A'T versions", N);
5226 -- Make entry in unchecked conversion table for later processing by
5227 -- Validate_Unchecked_Conversions, which will check sizes and alignments
5228 -- (using values set by the back-end where possible). This is only done
5229 -- if the appropriate warning is active.
5231 if Warn_On_Unchecked_Conversion then
5232 Unchecked_Conversions.Append
5233 (New_Val => UC_Entry'
5238 -- If both sizes are known statically now, then back end annotation
5239 -- is not required to do a proper check but if either size is not
5240 -- known statically, then we need the annotation.
5242 if Known_Static_RM_Size (Source)
5243 and then Known_Static_RM_Size (Target)
5247 Back_Annotate_Rep_Info := True;
5251 -- If unchecked conversion to access type, and access type is declared
5252 -- in the same unit as the unchecked conversion, then set the
5253 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
5256 if Is_Access_Type (Target) and then
5257 In_Same_Source_Unit (Target, N)
5259 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
5262 -- Generate N_Validate_Unchecked_Conversion node for back end in
5263 -- case the back end needs to perform special validation checks.
5265 -- Shouldn't this be in Exp_Ch13, since the check only gets done
5266 -- if we have full expansion and the back end is called ???
5269 Make_Validate_Unchecked_Conversion (Sloc (N));
5270 Set_Source_Type (Vnode, Source);
5271 Set_Target_Type (Vnode, Target);
5273 -- If the unchecked conversion node is in a list, just insert before it.
5274 -- If not we have some strange case, not worth bothering about.
5276 if Is_List_Member (N) then
5277 Insert_After (N, Vnode);
5279 end Validate_Unchecked_Conversion;
5281 ------------------------------------
5282 -- Validate_Unchecked_Conversions --
5283 ------------------------------------
5285 procedure Validate_Unchecked_Conversions is
5287 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
5289 T : UC_Entry renames Unchecked_Conversions.Table (N);
5291 Eloc : constant Source_Ptr := T.Eloc;
5292 Source : constant Entity_Id := T.Source;
5293 Target : constant Entity_Id := T.Target;
5299 -- This validation check, which warns if we have unequal sizes for
5300 -- unchecked conversion, and thus potentially implementation
5301 -- dependent semantics, is one of the few occasions on which we
5302 -- use the official RM size instead of Esize. See description in
5303 -- Einfo "Handling of Type'Size Values" for details.
5305 if Serious_Errors_Detected = 0
5306 and then Known_Static_RM_Size (Source)
5307 and then Known_Static_RM_Size (Target)
5309 -- Don't do the check if warnings off for either type, note the
5310 -- deliberate use of OR here instead of OR ELSE to get the flag
5311 -- Warnings_Off_Used set for both types if appropriate.
5313 and then not (Has_Warnings_Off (Source)
5315 Has_Warnings_Off (Target))
5317 Source_Siz := RM_Size (Source);
5318 Target_Siz := RM_Size (Target);
5320 if Source_Siz /= Target_Siz then
5322 ("?types for unchecked conversion have different sizes!",
5325 if All_Errors_Mode then
5326 Error_Msg_Name_1 := Chars (Source);
5327 Error_Msg_Uint_1 := Source_Siz;
5328 Error_Msg_Name_2 := Chars (Target);
5329 Error_Msg_Uint_2 := Target_Siz;
5330 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
5332 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
5334 if Is_Discrete_Type (Source)
5335 and then Is_Discrete_Type (Target)
5337 if Source_Siz > Target_Siz then
5339 ("\?^ high order bits of source will be ignored!",
5342 elsif Is_Unsigned_Type (Source) then
5344 ("\?source will be extended with ^ high order " &
5345 "zero bits?!", Eloc);
5349 ("\?source will be extended with ^ high order " &
5354 elsif Source_Siz < Target_Siz then
5355 if Is_Discrete_Type (Target) then
5356 if Bytes_Big_Endian then
5358 ("\?target value will include ^ undefined " &
5363 ("\?target value will include ^ undefined " &
5370 ("\?^ trailing bits of target value will be " &
5371 "undefined!", Eloc);
5374 else pragma Assert (Source_Siz > Target_Siz);
5376 ("\?^ trailing bits of source will be ignored!",
5383 -- If both types are access types, we need to check the alignment.
5384 -- If the alignment of both is specified, we can do it here.
5386 if Serious_Errors_Detected = 0
5387 and then Ekind (Source) in Access_Kind
5388 and then Ekind (Target) in Access_Kind
5389 and then Target_Strict_Alignment
5390 and then Present (Designated_Type (Source))
5391 and then Present (Designated_Type (Target))
5394 D_Source : constant Entity_Id := Designated_Type (Source);
5395 D_Target : constant Entity_Id := Designated_Type (Target);
5398 if Known_Alignment (D_Source)
5399 and then Known_Alignment (D_Target)
5402 Source_Align : constant Uint := Alignment (D_Source);
5403 Target_Align : constant Uint := Alignment (D_Target);
5406 if Source_Align < Target_Align
5407 and then not Is_Tagged_Type (D_Source)
5409 -- Suppress warning if warnings suppressed on either
5410 -- type or either designated type. Note the use of
5411 -- OR here instead of OR ELSE. That is intentional,
5412 -- we would like to set flag Warnings_Off_Used in
5413 -- all types for which warnings are suppressed.
5415 and then not (Has_Warnings_Off (D_Source)
5417 Has_Warnings_Off (D_Target)
5419 Has_Warnings_Off (Source)
5421 Has_Warnings_Off (Target))
5423 Error_Msg_Uint_1 := Target_Align;
5424 Error_Msg_Uint_2 := Source_Align;
5425 Error_Msg_Node_1 := D_Target;
5426 Error_Msg_Node_2 := D_Source;
5428 ("?alignment of & (^) is stricter than " &
5429 "alignment of & (^)!", Eloc);
5431 ("\?resulting access value may have invalid " &
5432 "alignment!", Eloc);
5440 end Validate_Unchecked_Conversions;
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