1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Disp; use Exp_Disp;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
35 with Lib.Xref; use Lib.Xref;
36 with Namet; use Namet;
37 with Nlists; use Nlists;
38 with Nmake; use Nmake;
40 with Restrict; use Restrict;
41 with Rident; use Rident;
42 with Rtsfind; use Rtsfind;
44 with Sem_Aux; use Sem_Aux;
45 with Sem_Ch3; use Sem_Ch3;
46 with Sem_Ch8; use Sem_Ch8;
47 with Sem_Eval; use Sem_Eval;
48 with Sem_Res; use Sem_Res;
49 with Sem_Type; use Sem_Type;
50 with Sem_Util; use Sem_Util;
51 with Sem_Warn; use Sem_Warn;
52 with Snames; use Snames;
53 with Stand; use Stand;
54 with Sinfo; use Sinfo;
56 with Targparm; use Targparm;
57 with Ttypes; use Ttypes;
58 with Tbuild; use Tbuild;
59 with Urealp; use Urealp;
61 with GNAT.Heap_Sort_G;
63 package body Sem_Ch13 is
65 SSU : constant Pos := System_Storage_Unit;
66 -- Convenient short hand for commonly used constant
68 -----------------------
69 -- Local Subprograms --
70 -----------------------
72 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
73 -- This routine is called after setting the Esize of type entity Typ.
74 -- The purpose is to deal with the situation where an alignment has been
75 -- inherited from a derived type that is no longer appropriate for the
76 -- new Esize value. In this case, we reset the Alignment to unknown.
78 function Get_Alignment_Value (Expr : Node_Id) return Uint;
79 -- Given the expression for an alignment value, returns the corresponding
80 -- Uint value. If the value is inappropriate, then error messages are
81 -- posted as required, and a value of No_Uint is returned.
83 function Is_Operational_Item (N : Node_Id) return Boolean;
84 -- A specification for a stream attribute is allowed before the full
85 -- type is declared, as explained in AI-00137 and the corrigendum.
86 -- Attributes that do not specify a representation characteristic are
87 -- operational attributes.
89 procedure New_Stream_Subprogram
94 -- Create a subprogram renaming of a given stream attribute to the
95 -- designated subprogram and then in the tagged case, provide this as a
96 -- primitive operation, or in the non-tagged case make an appropriate TSS
97 -- entry. This is more properly an expansion activity than just semantics,
98 -- but the presence of user-defined stream functions for limited types is a
99 -- legality check, which is why this takes place here rather than in
100 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
101 -- function to be generated.
103 -- To avoid elaboration anomalies with freeze nodes, for untagged types
104 -- we generate both a subprogram declaration and a subprogram renaming
105 -- declaration, so that the attribute specification is handled as a
106 -- renaming_as_body. For tagged types, the specification is one of the
113 Biased : Boolean := True);
114 -- If Biased is True, sets Has_Biased_Representation flag for E, and
115 -- outputs a warning message at node N if Warn_On_Biased_Representation is
116 -- is True. This warning inserts the string Msg to describe the construct
119 ----------------------------------------------
120 -- Table for Validate_Unchecked_Conversions --
121 ----------------------------------------------
123 -- The following table collects unchecked conversions for validation.
124 -- Entries are made by Validate_Unchecked_Conversion and then the
125 -- call to Validate_Unchecked_Conversions does the actual error
126 -- checking and posting of warnings. The reason for this delayed
127 -- processing is to take advantage of back-annotations of size and
128 -- alignment values performed by the back end.
130 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
131 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
132 -- will already have modified all Sloc values if the -gnatD option is set.
134 type UC_Entry is record
135 Eloc : Source_Ptr; -- node used for posting warnings
136 Source : Entity_Id; -- source type for unchecked conversion
137 Target : Entity_Id; -- target type for unchecked conversion
140 package Unchecked_Conversions is new Table.Table (
141 Table_Component_Type => UC_Entry,
142 Table_Index_Type => Int,
143 Table_Low_Bound => 1,
145 Table_Increment => 200,
146 Table_Name => "Unchecked_Conversions");
148 ----------------------------------------
149 -- Table for Validate_Address_Clauses --
150 ----------------------------------------
152 -- If an address clause has the form
154 -- for X'Address use Expr
156 -- where Expr is of the form Y'Address or recursively is a reference
157 -- to a constant of either of these forms, and X and Y are entities of
158 -- objects, then if Y has a smaller alignment than X, that merits a
159 -- warning about possible bad alignment. The following table collects
160 -- address clauses of this kind. We put these in a table so that they
161 -- can be checked after the back end has completed annotation of the
162 -- alignments of objects, since we can catch more cases that way.
164 type Address_Clause_Check_Record is record
166 -- The address clause
169 -- The entity of the object overlaying Y
172 -- The entity of the object being overlaid
175 -- Whether the address is offseted within Y
178 package Address_Clause_Checks is new Table.Table (
179 Table_Component_Type => Address_Clause_Check_Record,
180 Table_Index_Type => Int,
181 Table_Low_Bound => 1,
183 Table_Increment => 200,
184 Table_Name => "Address_Clause_Checks");
186 -----------------------------------------
187 -- Adjust_Record_For_Reverse_Bit_Order --
188 -----------------------------------------
190 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
195 -- Processing depends on version of Ada
197 -- For Ada 95, we just renumber bits within a storage unit. We do the
198 -- same for Ada 83 mode, since we recognize pragma Bit_Order in Ada 83,
199 -- and are free to add this extension.
201 if Ada_Version < Ada_2005 then
202 Comp := First_Component_Or_Discriminant (R);
203 while Present (Comp) loop
204 CC := Component_Clause (Comp);
206 -- If component clause is present, then deal with the non-default
207 -- bit order case for Ada 95 mode.
209 -- We only do this processing for the base type, and in fact that
210 -- is important, since otherwise if there are record subtypes, we
211 -- could reverse the bits once for each subtype, which is wrong.
214 and then Ekind (R) = E_Record_Type
217 CFB : constant Uint := Component_Bit_Offset (Comp);
218 CSZ : constant Uint := Esize (Comp);
219 CLC : constant Node_Id := Component_Clause (Comp);
220 Pos : constant Node_Id := Position (CLC);
221 FB : constant Node_Id := First_Bit (CLC);
223 Storage_Unit_Offset : constant Uint :=
224 CFB / System_Storage_Unit;
226 Start_Bit : constant Uint :=
227 CFB mod System_Storage_Unit;
230 -- Cases where field goes over storage unit boundary
232 if Start_Bit + CSZ > System_Storage_Unit then
234 -- Allow multi-byte field but generate warning
236 if Start_Bit mod System_Storage_Unit = 0
237 and then CSZ mod System_Storage_Unit = 0
240 ("multi-byte field specified with non-standard"
241 & " Bit_Order?", CLC);
243 if Bytes_Big_Endian then
245 ("bytes are not reversed "
246 & "(component is big-endian)?", CLC);
249 ("bytes are not reversed "
250 & "(component is little-endian)?", CLC);
253 -- Do not allow non-contiguous field
257 ("attempt to specify non-contiguous field "
258 & "not permitted", CLC);
260 ("\caused by non-standard Bit_Order "
263 ("\consider possibility of using "
264 & "Ada 2005 mode here", CLC);
267 -- Case where field fits in one storage unit
270 -- Give warning if suspicious component clause
272 if Intval (FB) >= System_Storage_Unit
273 and then Warn_On_Reverse_Bit_Order
276 ("?Bit_Order clause does not affect " &
277 "byte ordering", Pos);
279 Intval (Pos) + Intval (FB) /
282 ("?position normalized to ^ before bit " &
283 "order interpreted", Pos);
286 -- Here is where we fix up the Component_Bit_Offset value
287 -- to account for the reverse bit order. Some examples of
288 -- what needs to be done are:
290 -- First_Bit .. Last_Bit Component_Bit_Offset
302 -- The rule is that the first bit is is obtained by
303 -- subtracting the old ending bit from storage_unit - 1.
305 Set_Component_Bit_Offset
307 (Storage_Unit_Offset * System_Storage_Unit) +
308 (System_Storage_Unit - 1) -
309 (Start_Bit + CSZ - 1));
311 Set_Normalized_First_Bit
313 Component_Bit_Offset (Comp) mod
314 System_Storage_Unit);
319 Next_Component_Or_Discriminant (Comp);
322 -- For Ada 2005, we do machine scalar processing, as fully described In
323 -- AI-133. This involves gathering all components which start at the
324 -- same byte offset and processing them together. Same approach is still
325 -- valid in later versions including Ada 2012.
329 Max_Machine_Scalar_Size : constant Uint :=
331 (Standard_Long_Long_Integer_Size);
332 -- We use this as the maximum machine scalar size
335 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
338 -- This first loop through components does two things. First it
339 -- deals with the case of components with component clauses whose
340 -- length is greater than the maximum machine scalar size (either
341 -- accepting them or rejecting as needed). Second, it counts the
342 -- number of components with component clauses whose length does
343 -- not exceed this maximum for later processing.
346 Comp := First_Component_Or_Discriminant (R);
347 while Present (Comp) loop
348 CC := Component_Clause (Comp);
352 Fbit : constant Uint :=
353 Static_Integer (First_Bit (CC));
356 -- Case of component with size > max machine scalar
358 if Esize (Comp) > Max_Machine_Scalar_Size then
360 -- Must begin on byte boundary
362 if Fbit mod SSU /= 0 then
364 ("illegal first bit value for "
365 & "reverse bit order",
367 Error_Msg_Uint_1 := SSU;
368 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
371 ("\must be a multiple of ^ "
372 & "if size greater than ^",
375 -- Must end on byte boundary
377 elsif Esize (Comp) mod SSU /= 0 then
379 ("illegal last bit value for "
380 & "reverse bit order",
382 Error_Msg_Uint_1 := SSU;
383 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
386 ("\must be a multiple of ^ if size "
390 -- OK, give warning if enabled
392 elsif Warn_On_Reverse_Bit_Order then
394 ("multi-byte field specified with "
395 & " non-standard Bit_Order?", CC);
397 if Bytes_Big_Endian then
399 ("\bytes are not reversed "
400 & "(component is big-endian)?", CC);
403 ("\bytes are not reversed "
404 & "(component is little-endian)?", CC);
408 -- Case where size is not greater than max machine
409 -- scalar. For now, we just count these.
412 Num_CC := Num_CC + 1;
417 Next_Component_Or_Discriminant (Comp);
420 -- We need to sort the component clauses on the basis of the
421 -- Position values in the clause, so we can group clauses with
422 -- the same Position. together to determine the relevant machine
426 Comps : array (0 .. Num_CC) of Entity_Id;
427 -- Array to collect component and discriminant entities. The
428 -- data starts at index 1, the 0'th entry is for the sort
431 function CP_Lt (Op1, Op2 : Natural) return Boolean;
432 -- Compare routine for Sort
434 procedure CP_Move (From : Natural; To : Natural);
435 -- Move routine for Sort
437 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
441 -- Start and stop positions in the component list of the set of
442 -- components with the same starting position (that constitute
443 -- components in a single machine scalar).
446 -- Maximum last bit value of any component in this set
449 -- Corresponding machine scalar size
455 function CP_Lt (Op1, Op2 : Natural) return Boolean is
457 return Position (Component_Clause (Comps (Op1))) <
458 Position (Component_Clause (Comps (Op2)));
465 procedure CP_Move (From : Natural; To : Natural) is
467 Comps (To) := Comps (From);
470 -- Start of processing for Sort_CC
473 -- Collect the component clauses
476 Comp := First_Component_Or_Discriminant (R);
477 while Present (Comp) loop
478 if Present (Component_Clause (Comp))
479 and then Esize (Comp) <= Max_Machine_Scalar_Size
481 Num_CC := Num_CC + 1;
482 Comps (Num_CC) := Comp;
485 Next_Component_Or_Discriminant (Comp);
488 -- Sort by ascending position number
490 Sorting.Sort (Num_CC);
492 -- We now have all the components whose size does not exceed
493 -- the max machine scalar value, sorted by starting position.
494 -- In this loop we gather groups of clauses starting at the
495 -- same position, to process them in accordance with AI-133.
498 while Stop < Num_CC loop
503 (Last_Bit (Component_Clause (Comps (Start))));
504 while Stop < Num_CC loop
506 (Position (Component_Clause (Comps (Stop + 1)))) =
508 (Position (Component_Clause (Comps (Stop))))
516 (Component_Clause (Comps (Stop)))));
522 -- Now we have a group of component clauses from Start to
523 -- Stop whose positions are identical, and MaxL is the
524 -- maximum last bit value of any of these components.
526 -- We need to determine the corresponding machine scalar
527 -- size. This loop assumes that machine scalar sizes are
528 -- even, and that each possible machine scalar has twice
529 -- as many bits as the next smaller one.
531 MSS := Max_Machine_Scalar_Size;
533 and then (MSS / 2) >= SSU
534 and then (MSS / 2) > MaxL
539 -- Here is where we fix up the Component_Bit_Offset value
540 -- to account for the reverse bit order. Some examples of
541 -- what needs to be done for the case of a machine scalar
544 -- First_Bit .. Last_Bit Component_Bit_Offset
556 -- The rule is that the first bit is obtained by subtracting
557 -- the old ending bit from machine scalar size - 1.
559 for C in Start .. Stop loop
561 Comp : constant Entity_Id := Comps (C);
562 CC : constant Node_Id :=
563 Component_Clause (Comp);
564 LB : constant Uint :=
565 Static_Integer (Last_Bit (CC));
566 NFB : constant Uint := MSS - Uint_1 - LB;
567 NLB : constant Uint := NFB + Esize (Comp) - 1;
568 Pos : constant Uint :=
569 Static_Integer (Position (CC));
572 if Warn_On_Reverse_Bit_Order then
573 Error_Msg_Uint_1 := MSS;
575 ("info: reverse bit order in machine " &
576 "scalar of length^?", First_Bit (CC));
577 Error_Msg_Uint_1 := NFB;
578 Error_Msg_Uint_2 := NLB;
580 if Bytes_Big_Endian then
582 ("?\info: big-endian range for "
583 & "component & is ^ .. ^",
584 First_Bit (CC), Comp);
587 ("?\info: little-endian range "
588 & "for component & is ^ .. ^",
589 First_Bit (CC), Comp);
593 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
594 Set_Normalized_First_Bit (Comp, NFB mod SSU);
601 end Adjust_Record_For_Reverse_Bit_Order;
603 --------------------------------------
604 -- Alignment_Check_For_Esize_Change --
605 --------------------------------------
607 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
609 -- If the alignment is known, and not set by a rep clause, and is
610 -- inconsistent with the size being set, then reset it to unknown,
611 -- we assume in this case that the size overrides the inherited
612 -- alignment, and that the alignment must be recomputed.
614 if Known_Alignment (Typ)
615 and then not Has_Alignment_Clause (Typ)
616 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
618 Init_Alignment (Typ);
620 end Alignment_Check_For_Esize_Change;
622 -----------------------
623 -- Analyze_At_Clause --
624 -----------------------
626 -- An at clause is replaced by the corresponding Address attribute
627 -- definition clause that is the preferred approach in Ada 95.
629 procedure Analyze_At_Clause (N : Node_Id) is
630 CS : constant Boolean := Comes_From_Source (N);
633 -- This is an obsolescent feature
635 Check_Restriction (No_Obsolescent_Features, N);
637 if Warn_On_Obsolescent_Feature then
639 ("at clause is an obsolescent feature (RM J.7(2))?", N);
641 ("\use address attribute definition clause instead?", N);
644 -- Rewrite as address clause
647 Make_Attribute_Definition_Clause (Sloc (N),
648 Name => Identifier (N),
649 Chars => Name_Address,
650 Expression => Expression (N)));
652 -- We preserve Comes_From_Source, since logically the clause still
653 -- comes from the source program even though it is changed in form.
655 Set_Comes_From_Source (N, CS);
657 -- Analyze rewritten clause
659 Analyze_Attribute_Definition_Clause (N);
660 end Analyze_At_Clause;
662 -----------------------------------------
663 -- Analyze_Attribute_Definition_Clause --
664 -----------------------------------------
666 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
667 Loc : constant Source_Ptr := Sloc (N);
668 Nam : constant Node_Id := Name (N);
669 Attr : constant Name_Id := Chars (N);
670 Expr : constant Node_Id := Expression (N);
671 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
675 FOnly : Boolean := False;
676 -- Reset to True for subtype specific attribute (Alignment, Size)
677 -- and for stream attributes, i.e. those cases where in the call
678 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
679 -- rules are checked. Note that the case of stream attributes is not
680 -- clear from the RM, but see AI95-00137. Also, the RM seems to
681 -- disallow Storage_Size for derived task types, but that is also
682 -- clearly unintentional.
684 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
685 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
686 -- definition clauses.
688 -----------------------------------
689 -- Analyze_Stream_TSS_Definition --
690 -----------------------------------
692 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
693 Subp : Entity_Id := Empty;
698 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
700 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
701 -- Return true if the entity is a subprogram with an appropriate
702 -- profile for the attribute being defined.
704 ----------------------
705 -- Has_Good_Profile --
706 ----------------------
708 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
710 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
711 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
712 (False => E_Procedure, True => E_Function);
716 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
720 F := First_Formal (Subp);
723 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
724 or else Designated_Type (Etype (F)) /=
725 Class_Wide_Type (RTE (RE_Root_Stream_Type))
730 if not Is_Function then
734 Expected_Mode : constant array (Boolean) of Entity_Kind :=
735 (False => E_In_Parameter,
736 True => E_Out_Parameter);
738 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
749 return Base_Type (Typ) = Base_Type (Ent)
750 and then No (Next_Formal (F));
751 end Has_Good_Profile;
753 -- Start of processing for Analyze_Stream_TSS_Definition
758 if not Is_Type (U_Ent) then
759 Error_Msg_N ("local name must be a subtype", Nam);
763 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
765 -- If Pnam is present, it can be either inherited from an ancestor
766 -- type (in which case it is legal to redefine it for this type), or
767 -- be a previous definition of the attribute for the same type (in
768 -- which case it is illegal).
770 -- In the first case, it will have been analyzed already, and we
771 -- can check that its profile does not match the expected profile
772 -- for a stream attribute of U_Ent. In the second case, either Pnam
773 -- has been analyzed (and has the expected profile), or it has not
774 -- been analyzed yet (case of a type that has not been frozen yet
775 -- and for which the stream attribute has been set using Set_TSS).
778 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
780 Error_Msg_Sloc := Sloc (Pnam);
781 Error_Msg_Name_1 := Attr;
782 Error_Msg_N ("% attribute already defined #", Nam);
788 if Is_Entity_Name (Expr) then
789 if not Is_Overloaded (Expr) then
790 if Has_Good_Profile (Entity (Expr)) then
791 Subp := Entity (Expr);
795 Get_First_Interp (Expr, I, It);
796 while Present (It.Nam) loop
797 if Has_Good_Profile (It.Nam) then
802 Get_Next_Interp (I, It);
807 if Present (Subp) then
808 if Is_Abstract_Subprogram (Subp) then
809 Error_Msg_N ("stream subprogram must not be abstract", Expr);
813 Set_Entity (Expr, Subp);
814 Set_Etype (Expr, Etype (Subp));
816 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
819 Error_Msg_Name_1 := Attr;
820 Error_Msg_N ("incorrect expression for% attribute", Expr);
822 end Analyze_Stream_TSS_Definition;
824 -- Start of processing for Analyze_Attribute_Definition_Clause
827 -- Process Ignore_Rep_Clauses option
829 if Ignore_Rep_Clauses then
832 -- The following should be ignored. They do not affect legality
833 -- and may be target dependent. The basic idea of -gnatI is to
834 -- ignore any rep clauses that may be target dependent but do not
835 -- affect legality (except possibly to be rejected because they
836 -- are incompatible with the compilation target).
838 when Attribute_Alignment |
839 Attribute_Bit_Order |
840 Attribute_Component_Size |
841 Attribute_Machine_Radix |
842 Attribute_Object_Size |
845 Attribute_Stream_Size |
846 Attribute_Value_Size =>
848 Rewrite (N, Make_Null_Statement (Sloc (N)));
851 -- The following should not be ignored, because in the first place
852 -- they are reasonably portable, and should not cause problems in
853 -- compiling code from another target, and also they do affect
854 -- legality, e.g. failing to provide a stream attribute for a
855 -- type may make a program illegal.
857 when Attribute_External_Tag |
861 Attribute_Storage_Pool |
862 Attribute_Storage_Size |
866 -- Other cases are errors ("attribute& cannot be set with
867 -- definition clause"), which will be caught below.
877 if Rep_Item_Too_Early (Ent, N) then
881 -- Rep clause applies to full view of incomplete type or private type if
882 -- we have one (if not, this is a premature use of the type). However,
883 -- certain semantic checks need to be done on the specified entity (i.e.
884 -- the private view), so we save it in Ent.
886 if Is_Private_Type (Ent)
887 and then Is_Derived_Type (Ent)
888 and then not Is_Tagged_Type (Ent)
889 and then No (Full_View (Ent))
891 -- If this is a private type whose completion is a derivation from
892 -- another private type, there is no full view, and the attribute
893 -- belongs to the type itself, not its underlying parent.
897 elsif Ekind (Ent) = E_Incomplete_Type then
899 -- The attribute applies to the full view, set the entity of the
900 -- attribute definition accordingly.
902 Ent := Underlying_Type (Ent);
904 Set_Entity (Nam, Ent);
907 U_Ent := Underlying_Type (Ent);
910 -- Complete other routine error checks
912 if Etype (Nam) = Any_Type then
915 elsif Scope (Ent) /= Current_Scope then
916 Error_Msg_N ("entity must be declared in this scope", Nam);
919 elsif No (U_Ent) then
922 elsif Is_Type (U_Ent)
923 and then not Is_First_Subtype (U_Ent)
924 and then Id /= Attribute_Object_Size
925 and then Id /= Attribute_Value_Size
926 and then not From_At_Mod (N)
928 Error_Msg_N ("cannot specify attribute for subtype", Nam);
932 -- Switch on particular attribute
940 -- Address attribute definition clause
942 when Attribute_Address => Address : begin
944 -- A little error check, catch for X'Address use X'Address;
946 if Nkind (Nam) = N_Identifier
947 and then Nkind (Expr) = N_Attribute_Reference
948 and then Attribute_Name (Expr) = Name_Address
949 and then Nkind (Prefix (Expr)) = N_Identifier
950 and then Chars (Nam) = Chars (Prefix (Expr))
953 ("address for & is self-referencing", Prefix (Expr), Ent);
957 -- Not that special case, carry on with analysis of expression
959 Analyze_And_Resolve (Expr, RTE (RE_Address));
961 -- Even when ignoring rep clauses we need to indicate that the
962 -- entity has an address clause and thus it is legal to declare
965 if Ignore_Rep_Clauses then
966 if Ekind_In (U_Ent, E_Variable, E_Constant) then
967 Record_Rep_Item (U_Ent, N);
973 if Present (Address_Clause (U_Ent)) then
974 Error_Msg_N ("address already given for &", Nam);
976 -- Case of address clause for subprogram
978 elsif Is_Subprogram (U_Ent) then
979 if Has_Homonym (U_Ent) then
981 ("address clause cannot be given " &
982 "for overloaded subprogram",
987 -- For subprograms, all address clauses are permitted, and we
988 -- mark the subprogram as having a deferred freeze so that Gigi
989 -- will not elaborate it too soon.
991 -- Above needs more comments, what is too soon about???
993 Set_Has_Delayed_Freeze (U_Ent);
995 -- Case of address clause for entry
997 elsif Ekind (U_Ent) = E_Entry then
998 if Nkind (Parent (N)) = N_Task_Body then
1000 ("entry address must be specified in task spec", Nam);
1004 -- For entries, we require a constant address
1006 Check_Constant_Address_Clause (Expr, U_Ent);
1008 -- Special checks for task types
1010 if Is_Task_Type (Scope (U_Ent))
1011 and then Comes_From_Source (Scope (U_Ent))
1014 ("?entry address declared for entry in task type", N);
1016 ("\?only one task can be declared of this type", N);
1019 -- Entry address clauses are obsolescent
1021 Check_Restriction (No_Obsolescent_Features, N);
1023 if Warn_On_Obsolescent_Feature then
1025 ("attaching interrupt to task entry is an " &
1026 "obsolescent feature (RM J.7.1)?", N);
1028 ("\use interrupt procedure instead?", N);
1031 -- Case of an address clause for a controlled object which we
1032 -- consider to be erroneous.
1034 elsif Is_Controlled (Etype (U_Ent))
1035 or else Has_Controlled_Component (Etype (U_Ent))
1038 ("?controlled object& must not be overlaid", Nam, U_Ent);
1040 ("\?Program_Error will be raised at run time", Nam);
1041 Insert_Action (Declaration_Node (U_Ent),
1042 Make_Raise_Program_Error (Loc,
1043 Reason => PE_Overlaid_Controlled_Object));
1046 -- Case of address clause for a (non-controlled) object
1049 Ekind (U_Ent) = E_Variable
1051 Ekind (U_Ent) = E_Constant
1054 Expr : constant Node_Id := Expression (N);
1059 -- Exported variables cannot have an address clause, because
1060 -- this cancels the effect of the pragma Export.
1062 if Is_Exported (U_Ent) then
1064 ("cannot export object with address clause", Nam);
1068 Find_Overlaid_Entity (N, O_Ent, Off);
1070 -- Overlaying controlled objects is erroneous
1073 and then (Has_Controlled_Component (Etype (O_Ent))
1074 or else Is_Controlled (Etype (O_Ent)))
1077 ("?cannot overlay with controlled object", Expr);
1079 ("\?Program_Error will be raised at run time", Expr);
1080 Insert_Action (Declaration_Node (U_Ent),
1081 Make_Raise_Program_Error (Loc,
1082 Reason => PE_Overlaid_Controlled_Object));
1085 elsif Present (O_Ent)
1086 and then Ekind (U_Ent) = E_Constant
1087 and then not Is_Constant_Object (O_Ent)
1089 Error_Msg_N ("constant overlays a variable?", Expr);
1091 elsif Present (Renamed_Object (U_Ent)) then
1093 ("address clause not allowed"
1094 & " for a renaming declaration (RM 13.1(6))", Nam);
1097 -- Imported variables can have an address clause, but then
1098 -- the import is pretty meaningless except to suppress
1099 -- initializations, so we do not need such variables to
1100 -- be statically allocated (and in fact it causes trouble
1101 -- if the address clause is a local value).
1103 elsif Is_Imported (U_Ent) then
1104 Set_Is_Statically_Allocated (U_Ent, False);
1107 -- We mark a possible modification of a variable with an
1108 -- address clause, since it is likely aliasing is occurring.
1110 Note_Possible_Modification (Nam, Sure => False);
1112 -- Here we are checking for explicit overlap of one variable
1113 -- by another, and if we find this then mark the overlapped
1114 -- variable as also being volatile to prevent unwanted
1115 -- optimizations. This is a significant pessimization so
1116 -- avoid it when there is an offset, i.e. when the object
1117 -- is composite; they cannot be optimized easily anyway.
1120 and then Is_Object (O_Ent)
1123 Set_Treat_As_Volatile (O_Ent);
1126 -- Legality checks on the address clause for initialized
1127 -- objects is deferred until the freeze point, because
1128 -- a subsequent pragma might indicate that the object is
1129 -- imported and thus not initialized.
1131 Set_Has_Delayed_Freeze (U_Ent);
1133 -- If an initialization call has been generated for this
1134 -- object, it needs to be deferred to after the freeze node
1135 -- we have just now added, otherwise GIGI will see a
1136 -- reference to the variable (as actual to the IP call)
1137 -- before its definition.
1140 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1142 if Present (Init_Call) then
1144 Append_Freeze_Action (U_Ent, Init_Call);
1148 if Is_Exported (U_Ent) then
1150 ("& cannot be exported if an address clause is given",
1153 ("\define and export a variable " &
1154 "that holds its address instead",
1158 -- Entity has delayed freeze, so we will generate an
1159 -- alignment check at the freeze point unless suppressed.
1161 if not Range_Checks_Suppressed (U_Ent)
1162 and then not Alignment_Checks_Suppressed (U_Ent)
1164 Set_Check_Address_Alignment (N);
1167 -- Kill the size check code, since we are not allocating
1168 -- the variable, it is somewhere else.
1170 Kill_Size_Check_Code (U_Ent);
1172 -- If the address clause is of the form:
1174 -- for Y'Address use X'Address
1178 -- Const : constant Address := X'Address;
1180 -- for Y'Address use Const;
1182 -- then we make an entry in the table for checking the size
1183 -- and alignment of the overlaying variable. We defer this
1184 -- check till after code generation to take full advantage
1185 -- of the annotation done by the back end. This entry is
1186 -- only made if the address clause comes from source.
1187 -- If the entity has a generic type, the check will be
1188 -- performed in the instance if the actual type justifies
1189 -- it, and we do not insert the clause in the table to
1190 -- prevent spurious warnings.
1192 if Address_Clause_Overlay_Warnings
1193 and then Comes_From_Source (N)
1194 and then Present (O_Ent)
1195 and then Is_Object (O_Ent)
1197 if not Is_Generic_Type (Etype (U_Ent)) then
1198 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1201 -- If variable overlays a constant view, and we are
1202 -- warning on overlays, then mark the variable as
1203 -- overlaying a constant (we will give warnings later
1204 -- if this variable is assigned).
1206 if Is_Constant_Object (O_Ent)
1207 and then Ekind (U_Ent) = E_Variable
1209 Set_Overlays_Constant (U_Ent);
1214 -- Not a valid entity for an address clause
1217 Error_Msg_N ("address cannot be given for &", Nam);
1225 -- Alignment attribute definition clause
1227 when Attribute_Alignment => Alignment : declare
1228 Align : constant Uint := Get_Alignment_Value (Expr);
1233 if not Is_Type (U_Ent)
1234 and then Ekind (U_Ent) /= E_Variable
1235 and then Ekind (U_Ent) /= E_Constant
1237 Error_Msg_N ("alignment cannot be given for &", Nam);
1239 elsif Has_Alignment_Clause (U_Ent) then
1240 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1241 Error_Msg_N ("alignment clause previously given#", N);
1243 elsif Align /= No_Uint then
1244 Set_Has_Alignment_Clause (U_Ent);
1245 Set_Alignment (U_Ent, Align);
1247 -- For an array type, U_Ent is the first subtype. In that case,
1248 -- also set the alignment of the anonymous base type so that
1249 -- other subtypes (such as the itypes for aggregates of the
1250 -- type) also receive the expected alignment.
1252 if Is_Array_Type (U_Ent) then
1253 Set_Alignment (Base_Type (U_Ent), Align);
1262 -- Bit_Order attribute definition clause
1264 when Attribute_Bit_Order => Bit_Order : declare
1266 if not Is_Record_Type (U_Ent) then
1268 ("Bit_Order can only be defined for record type", Nam);
1271 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1273 if Etype (Expr) = Any_Type then
1276 elsif not Is_Static_Expression (Expr) then
1277 Flag_Non_Static_Expr
1278 ("Bit_Order requires static expression!", Expr);
1281 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1282 Set_Reverse_Bit_Order (U_Ent, True);
1288 --------------------
1289 -- Component_Size --
1290 --------------------
1292 -- Component_Size attribute definition clause
1294 when Attribute_Component_Size => Component_Size_Case : declare
1295 Csize : constant Uint := Static_Integer (Expr);
1299 New_Ctyp : Entity_Id;
1303 if not Is_Array_Type (U_Ent) then
1304 Error_Msg_N ("component size requires array type", Nam);
1308 Btype := Base_Type (U_Ent);
1309 Ctyp := Component_Type (Btype);
1311 if Has_Component_Size_Clause (Btype) then
1313 ("component size clause for& previously given", Nam);
1315 elsif Csize /= No_Uint then
1316 Check_Size (Expr, Ctyp, Csize, Biased);
1318 if Has_Aliased_Components (Btype)
1321 and then Csize /= 16
1324 ("component size incorrect for aliased components", N);
1328 -- For the biased case, build a declaration for a subtype
1329 -- that will be used to represent the biased subtype that
1330 -- reflects the biased representation of components. We need
1331 -- this subtype to get proper conversions on referencing
1332 -- elements of the array. Note that component size clauses
1333 -- are ignored in VM mode.
1335 if VM_Target = No_VM then
1338 Make_Defining_Identifier (Loc,
1340 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1343 Make_Subtype_Declaration (Loc,
1344 Defining_Identifier => New_Ctyp,
1345 Subtype_Indication =>
1346 New_Occurrence_Of (Component_Type (Btype), Loc));
1348 Set_Parent (Decl, N);
1349 Analyze (Decl, Suppress => All_Checks);
1351 Set_Has_Delayed_Freeze (New_Ctyp, False);
1352 Set_Esize (New_Ctyp, Csize);
1353 Set_RM_Size (New_Ctyp, Csize);
1354 Init_Alignment (New_Ctyp);
1355 Set_Is_Itype (New_Ctyp, True);
1356 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1358 Set_Component_Type (Btype, New_Ctyp);
1359 Set_Biased (New_Ctyp, N, "component size clause");
1362 Set_Component_Size (Btype, Csize);
1364 -- For VM case, we ignore component size clauses
1367 -- Give a warning unless we are in GNAT mode, in which case
1368 -- the warning is suppressed since it is not useful.
1370 if not GNAT_Mode then
1372 ("?component size ignored in this configuration", N);
1376 -- Deal with warning on overridden size
1378 if Warn_On_Overridden_Size
1379 and then Has_Size_Clause (Ctyp)
1380 and then RM_Size (Ctyp) /= Csize
1383 ("?component size overrides size clause for&",
1387 Set_Has_Component_Size_Clause (Btype, True);
1388 Set_Has_Non_Standard_Rep (Btype, True);
1390 end Component_Size_Case;
1396 when Attribute_External_Tag => External_Tag :
1398 if not Is_Tagged_Type (U_Ent) then
1399 Error_Msg_N ("should be a tagged type", Nam);
1402 Analyze_And_Resolve (Expr, Standard_String);
1404 if not Is_Static_Expression (Expr) then
1405 Flag_Non_Static_Expr
1406 ("static string required for tag name!", Nam);
1409 if VM_Target = No_VM then
1410 Set_Has_External_Tag_Rep_Clause (U_Ent);
1412 Error_Msg_Name_1 := Attr;
1414 ("% attribute unsupported in this configuration", Nam);
1417 if not Is_Library_Level_Entity (U_Ent) then
1419 ("?non-unique external tag supplied for &", N, U_Ent);
1421 ("?\same external tag applies to all subprogram calls", N);
1423 ("?\corresponding internal tag cannot be obtained", N);
1431 when Attribute_Input =>
1432 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1433 Set_Has_Specified_Stream_Input (Ent);
1439 -- Machine radix attribute definition clause
1441 when Attribute_Machine_Radix => Machine_Radix : declare
1442 Radix : constant Uint := Static_Integer (Expr);
1445 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1446 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1448 elsif Has_Machine_Radix_Clause (U_Ent) then
1449 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1450 Error_Msg_N ("machine radix clause previously given#", N);
1452 elsif Radix /= No_Uint then
1453 Set_Has_Machine_Radix_Clause (U_Ent);
1454 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1458 elsif Radix = 10 then
1459 Set_Machine_Radix_10 (U_Ent);
1461 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1470 -- Object_Size attribute definition clause
1472 when Attribute_Object_Size => Object_Size : declare
1473 Size : constant Uint := Static_Integer (Expr);
1476 pragma Warnings (Off, Biased);
1479 if not Is_Type (U_Ent) then
1480 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1482 elsif Has_Object_Size_Clause (U_Ent) then
1483 Error_Msg_N ("Object_Size already given for &", Nam);
1486 Check_Size (Expr, U_Ent, Size, Biased);
1494 UI_Mod (Size, 64) /= 0
1497 ("Object_Size must be 8, 16, 32, or multiple of 64",
1501 Set_Esize (U_Ent, Size);
1502 Set_Has_Object_Size_Clause (U_Ent);
1503 Alignment_Check_For_Esize_Change (U_Ent);
1511 when Attribute_Output =>
1512 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1513 Set_Has_Specified_Stream_Output (Ent);
1519 when Attribute_Read =>
1520 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1521 Set_Has_Specified_Stream_Read (Ent);
1527 -- Size attribute definition clause
1529 when Attribute_Size => Size : declare
1530 Size : constant Uint := Static_Integer (Expr);
1537 if Has_Size_Clause (U_Ent) then
1538 Error_Msg_N ("size already given for &", Nam);
1540 elsif not Is_Type (U_Ent)
1541 and then Ekind (U_Ent) /= E_Variable
1542 and then Ekind (U_Ent) /= E_Constant
1544 Error_Msg_N ("size cannot be given for &", Nam);
1546 elsif Is_Array_Type (U_Ent)
1547 and then not Is_Constrained (U_Ent)
1550 ("size cannot be given for unconstrained array", Nam);
1552 elsif Size /= No_Uint then
1554 if VM_Target /= No_VM and then not GNAT_Mode then
1556 -- Size clause is not handled properly on VM targets.
1557 -- Display a warning unless we are in GNAT mode, in which
1558 -- case this is useless.
1561 ("?size clauses are ignored in this configuration", N);
1564 if Is_Type (U_Ent) then
1567 Etyp := Etype (U_Ent);
1570 -- Check size, note that Gigi is in charge of checking that the
1571 -- size of an array or record type is OK. Also we do not check
1572 -- the size in the ordinary fixed-point case, since it is too
1573 -- early to do so (there may be subsequent small clause that
1574 -- affects the size). We can check the size if a small clause
1575 -- has already been given.
1577 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1578 or else Has_Small_Clause (U_Ent)
1580 Check_Size (Expr, Etyp, Size, Biased);
1581 Set_Biased (U_Ent, N, "size clause", Biased);
1584 -- For types set RM_Size and Esize if possible
1586 if Is_Type (U_Ent) then
1587 Set_RM_Size (U_Ent, Size);
1589 -- For scalar types, increase Object_Size to power of 2, but
1590 -- not less than a storage unit in any case (i.e., normally
1591 -- this means it will be byte addressable).
1593 if Is_Scalar_Type (U_Ent) then
1594 if Size <= System_Storage_Unit then
1595 Init_Esize (U_Ent, System_Storage_Unit);
1596 elsif Size <= 16 then
1597 Init_Esize (U_Ent, 16);
1598 elsif Size <= 32 then
1599 Init_Esize (U_Ent, 32);
1601 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1604 -- For all other types, object size = value size. The
1605 -- backend will adjust as needed.
1608 Set_Esize (U_Ent, Size);
1611 Alignment_Check_For_Esize_Change (U_Ent);
1613 -- For objects, set Esize only
1616 if Is_Elementary_Type (Etyp) then
1617 if Size /= System_Storage_Unit
1619 Size /= System_Storage_Unit * 2
1621 Size /= System_Storage_Unit * 4
1623 Size /= System_Storage_Unit * 8
1625 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1626 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1628 ("size for primitive object must be a power of 2"
1629 & " in the range ^-^", N);
1633 Set_Esize (U_Ent, Size);
1636 Set_Has_Size_Clause (U_Ent);
1644 -- Small attribute definition clause
1646 when Attribute_Small => Small : declare
1647 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1651 Analyze_And_Resolve (Expr, Any_Real);
1653 if Etype (Expr) = Any_Type then
1656 elsif not Is_Static_Expression (Expr) then
1657 Flag_Non_Static_Expr
1658 ("small requires static expression!", Expr);
1662 Small := Expr_Value_R (Expr);
1664 if Small <= Ureal_0 then
1665 Error_Msg_N ("small value must be greater than zero", Expr);
1671 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1673 ("small requires an ordinary fixed point type", Nam);
1675 elsif Has_Small_Clause (U_Ent) then
1676 Error_Msg_N ("small already given for &", Nam);
1678 elsif Small > Delta_Value (U_Ent) then
1680 ("small value must not be greater then delta value", Nam);
1683 Set_Small_Value (U_Ent, Small);
1684 Set_Small_Value (Implicit_Base, Small);
1685 Set_Has_Small_Clause (U_Ent);
1686 Set_Has_Small_Clause (Implicit_Base);
1687 Set_Has_Non_Standard_Rep (Implicit_Base);
1695 -- Storage_Pool attribute definition clause
1697 when Attribute_Storage_Pool => Storage_Pool : declare
1702 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1704 ("storage pool cannot be given for access-to-subprogram type",
1709 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
1712 ("storage pool can only be given for access types", Nam);
1715 elsif Is_Derived_Type (U_Ent) then
1717 ("storage pool cannot be given for a derived access type",
1720 elsif Has_Storage_Size_Clause (U_Ent) then
1721 Error_Msg_N ("storage size already given for &", Nam);
1724 elsif Present (Associated_Storage_Pool (U_Ent)) then
1725 Error_Msg_N ("storage pool already given for &", Nam);
1730 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1732 if not Denotes_Variable (Expr) then
1733 Error_Msg_N ("storage pool must be a variable", Expr);
1737 if Nkind (Expr) = N_Type_Conversion then
1738 T := Etype (Expression (Expr));
1743 -- The Stack_Bounded_Pool is used internally for implementing
1744 -- access types with a Storage_Size. Since it only work
1745 -- properly when used on one specific type, we need to check
1746 -- that it is not hijacked improperly:
1747 -- type T is access Integer;
1748 -- for T'Storage_Size use n;
1749 -- type Q is access Float;
1750 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1752 if RTE_Available (RE_Stack_Bounded_Pool)
1753 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1755 Error_Msg_N ("non-shareable internal Pool", Expr);
1759 -- If the argument is a name that is not an entity name, then
1760 -- we construct a renaming operation to define an entity of
1761 -- type storage pool.
1763 if not Is_Entity_Name (Expr)
1764 and then Is_Object_Reference (Expr)
1766 Pool := Make_Temporary (Loc, 'P', Expr);
1769 Rnode : constant Node_Id :=
1770 Make_Object_Renaming_Declaration (Loc,
1771 Defining_Identifier => Pool,
1773 New_Occurrence_Of (Etype (Expr), Loc),
1777 Insert_Before (N, Rnode);
1779 Set_Associated_Storage_Pool (U_Ent, Pool);
1782 elsif Is_Entity_Name (Expr) then
1783 Pool := Entity (Expr);
1785 -- If pool is a renamed object, get original one. This can
1786 -- happen with an explicit renaming, and within instances.
1788 while Present (Renamed_Object (Pool))
1789 and then Is_Entity_Name (Renamed_Object (Pool))
1791 Pool := Entity (Renamed_Object (Pool));
1794 if Present (Renamed_Object (Pool))
1795 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1796 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1798 Pool := Entity (Expression (Renamed_Object (Pool)));
1801 Set_Associated_Storage_Pool (U_Ent, Pool);
1803 elsif Nkind (Expr) = N_Type_Conversion
1804 and then Is_Entity_Name (Expression (Expr))
1805 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1807 Pool := Entity (Expression (Expr));
1808 Set_Associated_Storage_Pool (U_Ent, Pool);
1811 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1820 -- Storage_Size attribute definition clause
1822 when Attribute_Storage_Size => Storage_Size : declare
1823 Btype : constant Entity_Id := Base_Type (U_Ent);
1827 if Is_Task_Type (U_Ent) then
1828 Check_Restriction (No_Obsolescent_Features, N);
1830 if Warn_On_Obsolescent_Feature then
1832 ("storage size clause for task is an " &
1833 "obsolescent feature (RM J.9)?", N);
1834 Error_Msg_N ("\use Storage_Size pragma instead?", N);
1840 if not Is_Access_Type (U_Ent)
1841 and then Ekind (U_Ent) /= E_Task_Type
1843 Error_Msg_N ("storage size cannot be given for &", Nam);
1845 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1847 ("storage size cannot be given for a derived access type",
1850 elsif Has_Storage_Size_Clause (Btype) then
1851 Error_Msg_N ("storage size already given for &", Nam);
1854 Analyze_And_Resolve (Expr, Any_Integer);
1856 if Is_Access_Type (U_Ent) then
1857 if Present (Associated_Storage_Pool (U_Ent)) then
1858 Error_Msg_N ("storage pool already given for &", Nam);
1862 if Compile_Time_Known_Value (Expr)
1863 and then Expr_Value (Expr) = 0
1865 Set_No_Pool_Assigned (Btype);
1868 else -- Is_Task_Type (U_Ent)
1869 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1871 if Present (Sprag) then
1872 Error_Msg_Sloc := Sloc (Sprag);
1874 ("Storage_Size already specified#", Nam);
1879 Set_Has_Storage_Size_Clause (Btype);
1887 when Attribute_Stream_Size => Stream_Size : declare
1888 Size : constant Uint := Static_Integer (Expr);
1891 if Ada_Version <= Ada_95 then
1892 Check_Restriction (No_Implementation_Attributes, N);
1895 if Has_Stream_Size_Clause (U_Ent) then
1896 Error_Msg_N ("Stream_Size already given for &", Nam);
1898 elsif Is_Elementary_Type (U_Ent) then
1899 if Size /= System_Storage_Unit
1901 Size /= System_Storage_Unit * 2
1903 Size /= System_Storage_Unit * 4
1905 Size /= System_Storage_Unit * 8
1907 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1909 ("stream size for elementary type must be a"
1910 & " power of 2 and at least ^", N);
1912 elsif RM_Size (U_Ent) > Size then
1913 Error_Msg_Uint_1 := RM_Size (U_Ent);
1915 ("stream size for elementary type must be a"
1916 & " power of 2 and at least ^", N);
1919 Set_Has_Stream_Size_Clause (U_Ent);
1922 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1930 -- Value_Size attribute definition clause
1932 when Attribute_Value_Size => Value_Size : declare
1933 Size : constant Uint := Static_Integer (Expr);
1937 if not Is_Type (U_Ent) then
1938 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1941 (Get_Attribute_Definition_Clause
1942 (U_Ent, Attribute_Value_Size))
1944 Error_Msg_N ("Value_Size already given for &", Nam);
1946 elsif Is_Array_Type (U_Ent)
1947 and then not Is_Constrained (U_Ent)
1950 ("Value_Size cannot be given for unconstrained array", Nam);
1953 if Is_Elementary_Type (U_Ent) then
1954 Check_Size (Expr, U_Ent, Size, Biased);
1955 Set_Biased (U_Ent, N, "value size clause", Biased);
1958 Set_RM_Size (U_Ent, Size);
1966 when Attribute_Write =>
1967 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1968 Set_Has_Specified_Stream_Write (Ent);
1970 -- All other attributes cannot be set
1974 ("attribute& cannot be set with definition clause", N);
1977 -- The test for the type being frozen must be performed after
1978 -- any expression the clause has been analyzed since the expression
1979 -- itself might cause freezing that makes the clause illegal.
1981 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1984 end Analyze_Attribute_Definition_Clause;
1986 ----------------------------
1987 -- Analyze_Code_Statement --
1988 ----------------------------
1990 procedure Analyze_Code_Statement (N : Node_Id) is
1991 HSS : constant Node_Id := Parent (N);
1992 SBody : constant Node_Id := Parent (HSS);
1993 Subp : constant Entity_Id := Current_Scope;
2000 -- Analyze and check we get right type, note that this implements the
2001 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
2002 -- is the only way that Asm_Insn could possibly be visible.
2004 Analyze_And_Resolve (Expression (N));
2006 if Etype (Expression (N)) = Any_Type then
2008 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
2009 Error_Msg_N ("incorrect type for code statement", N);
2013 Check_Code_Statement (N);
2015 -- Make sure we appear in the handled statement sequence of a
2016 -- subprogram (RM 13.8(3)).
2018 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2019 or else Nkind (SBody) /= N_Subprogram_Body
2022 ("code statement can only appear in body of subprogram", N);
2026 -- Do remaining checks (RM 13.8(3)) if not already done
2028 if not Is_Machine_Code_Subprogram (Subp) then
2029 Set_Is_Machine_Code_Subprogram (Subp);
2031 -- No exception handlers allowed
2033 if Present (Exception_Handlers (HSS)) then
2035 ("exception handlers not permitted in machine code subprogram",
2036 First (Exception_Handlers (HSS)));
2039 -- No declarations other than use clauses and pragmas (we allow
2040 -- certain internally generated declarations as well).
2042 Decl := First (Declarations (SBody));
2043 while Present (Decl) loop
2044 DeclO := Original_Node (Decl);
2045 if Comes_From_Source (DeclO)
2046 and not Nkind_In (DeclO, N_Pragma,
2047 N_Use_Package_Clause,
2049 N_Implicit_Label_Declaration)
2052 ("this declaration not allowed in machine code subprogram",
2059 -- No statements other than code statements, pragmas, and labels.
2060 -- Again we allow certain internally generated statements.
2062 Stmt := First (Statements (HSS));
2063 while Present (Stmt) loop
2064 StmtO := Original_Node (Stmt);
2065 if Comes_From_Source (StmtO)
2066 and then not Nkind_In (StmtO, N_Pragma,
2071 ("this statement is not allowed in machine code subprogram",
2078 end Analyze_Code_Statement;
2080 -----------------------------------------------
2081 -- Analyze_Enumeration_Representation_Clause --
2082 -----------------------------------------------
2084 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2085 Ident : constant Node_Id := Identifier (N);
2086 Aggr : constant Node_Id := Array_Aggregate (N);
2087 Enumtype : Entity_Id;
2093 Err : Boolean := False;
2095 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2096 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2097 -- Allowed range of universal integer (= allowed range of enum lit vals)
2101 -- Minimum and maximum values of entries
2104 -- Pointer to node for literal providing max value
2107 if Ignore_Rep_Clauses then
2111 -- First some basic error checks
2114 Enumtype := Entity (Ident);
2116 if Enumtype = Any_Type
2117 or else Rep_Item_Too_Early (Enumtype, N)
2121 Enumtype := Underlying_Type (Enumtype);
2124 if not Is_Enumeration_Type (Enumtype) then
2126 ("enumeration type required, found}",
2127 Ident, First_Subtype (Enumtype));
2131 -- Ignore rep clause on generic actual type. This will already have
2132 -- been flagged on the template as an error, and this is the safest
2133 -- way to ensure we don't get a junk cascaded message in the instance.
2135 if Is_Generic_Actual_Type (Enumtype) then
2138 -- Type must be in current scope
2140 elsif Scope (Enumtype) /= Current_Scope then
2141 Error_Msg_N ("type must be declared in this scope", Ident);
2144 -- Type must be a first subtype
2146 elsif not Is_First_Subtype (Enumtype) then
2147 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2150 -- Ignore duplicate rep clause
2152 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2153 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2156 -- Don't allow rep clause for standard [wide_[wide_]]character
2158 elsif Is_Standard_Character_Type (Enumtype) then
2159 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2162 -- Check that the expression is a proper aggregate (no parentheses)
2164 elsif Paren_Count (Aggr) /= 0 then
2166 ("extra parentheses surrounding aggregate not allowed",
2170 -- All tests passed, so set rep clause in place
2173 Set_Has_Enumeration_Rep_Clause (Enumtype);
2174 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2177 -- Now we process the aggregate. Note that we don't use the normal
2178 -- aggregate code for this purpose, because we don't want any of the
2179 -- normal expansion activities, and a number of special semantic
2180 -- rules apply (including the component type being any integer type)
2182 Elit := First_Literal (Enumtype);
2184 -- First the positional entries if any
2186 if Present (Expressions (Aggr)) then
2187 Expr := First (Expressions (Aggr));
2188 while Present (Expr) loop
2190 Error_Msg_N ("too many entries in aggregate", Expr);
2194 Val := Static_Integer (Expr);
2196 -- Err signals that we found some incorrect entries processing
2197 -- the list. The final checks for completeness and ordering are
2198 -- skipped in this case.
2200 if Val = No_Uint then
2202 elsif Val < Lo or else Hi < Val then
2203 Error_Msg_N ("value outside permitted range", Expr);
2207 Set_Enumeration_Rep (Elit, Val);
2208 Set_Enumeration_Rep_Expr (Elit, Expr);
2214 -- Now process the named entries if present
2216 if Present (Component_Associations (Aggr)) then
2217 Assoc := First (Component_Associations (Aggr));
2218 while Present (Assoc) loop
2219 Choice := First (Choices (Assoc));
2221 if Present (Next (Choice)) then
2223 ("multiple choice not allowed here", Next (Choice));
2227 if Nkind (Choice) = N_Others_Choice then
2228 Error_Msg_N ("others choice not allowed here", Choice);
2231 elsif Nkind (Choice) = N_Range then
2232 -- ??? should allow zero/one element range here
2233 Error_Msg_N ("range not allowed here", Choice);
2237 Analyze_And_Resolve (Choice, Enumtype);
2239 if Is_Entity_Name (Choice)
2240 and then Is_Type (Entity (Choice))
2242 Error_Msg_N ("subtype name not allowed here", Choice);
2244 -- ??? should allow static subtype with zero/one entry
2246 elsif Etype (Choice) = Base_Type (Enumtype) then
2247 if not Is_Static_Expression (Choice) then
2248 Flag_Non_Static_Expr
2249 ("non-static expression used for choice!", Choice);
2253 Elit := Expr_Value_E (Choice);
2255 if Present (Enumeration_Rep_Expr (Elit)) then
2256 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2258 ("representation for& previously given#",
2263 Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
2265 Expr := Expression (Assoc);
2266 Val := Static_Integer (Expr);
2268 if Val = No_Uint then
2271 elsif Val < Lo or else Hi < Val then
2272 Error_Msg_N ("value outside permitted range", Expr);
2276 Set_Enumeration_Rep (Elit, Val);
2285 -- Aggregate is fully processed. Now we check that a full set of
2286 -- representations was given, and that they are in range and in order.
2287 -- These checks are only done if no other errors occurred.
2293 Elit := First_Literal (Enumtype);
2294 while Present (Elit) loop
2295 if No (Enumeration_Rep_Expr (Elit)) then
2296 Error_Msg_NE ("missing representation for&!", N, Elit);
2299 Val := Enumeration_Rep (Elit);
2301 if Min = No_Uint then
2305 if Val /= No_Uint then
2306 if Max /= No_Uint and then Val <= Max then
2308 ("enumeration value for& not ordered!",
2309 Enumeration_Rep_Expr (Elit), Elit);
2312 Max_Node := Enumeration_Rep_Expr (Elit);
2316 -- If there is at least one literal whose representation is not
2317 -- equal to the Pos value, then note that this enumeration type
2318 -- has a non-standard representation.
2320 if Val /= Enumeration_Pos (Elit) then
2321 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2328 -- Now set proper size information
2331 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2334 if Has_Size_Clause (Enumtype) then
2336 -- All OK, if size is OK now
2338 if RM_Size (Enumtype) >= Minsize then
2342 -- Try if we can get by with biasing
2345 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2347 -- Error message if even biasing does not work
2349 if RM_Size (Enumtype) < Minsize then
2350 Error_Msg_Uint_1 := RM_Size (Enumtype);
2351 Error_Msg_Uint_2 := Max;
2353 ("previously given size (^) is too small "
2354 & "for this value (^)", Max_Node);
2356 -- If biasing worked, indicate that we now have biased rep
2360 (Enumtype, Size_Clause (Enumtype), "size clause");
2365 Set_RM_Size (Enumtype, Minsize);
2366 Set_Enum_Esize (Enumtype);
2369 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2370 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2371 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2375 -- We repeat the too late test in case it froze itself!
2377 if Rep_Item_Too_Late (Enumtype, N) then
2380 end Analyze_Enumeration_Representation_Clause;
2382 ----------------------------
2383 -- Analyze_Free_Statement --
2384 ----------------------------
2386 procedure Analyze_Free_Statement (N : Node_Id) is
2388 Analyze (Expression (N));
2389 end Analyze_Free_Statement;
2391 ---------------------------
2392 -- Analyze_Freeze_Entity --
2393 ---------------------------
2395 procedure Analyze_Freeze_Entity (N : Node_Id) is
2396 E : constant Entity_Id := Entity (N);
2399 -- For tagged types covering interfaces add internal entities that link
2400 -- the primitives of the interfaces with the primitives that cover them.
2402 -- Note: These entities were originally generated only when generating
2403 -- code because their main purpose was to provide support to initialize
2404 -- the secondary dispatch tables. They are now generated also when
2405 -- compiling with no code generation to provide ASIS the relationship
2406 -- between interface primitives and tagged type primitives. They are
2407 -- also used to locate primitives covering interfaces when processing
2408 -- generics (see Derive_Subprograms).
2410 if Ada_Version >= Ada_05
2411 and then Ekind (E) = E_Record_Type
2412 and then Is_Tagged_Type (E)
2413 and then not Is_Interface (E)
2414 and then Has_Interfaces (E)
2416 -- This would be a good common place to call the routine that checks
2417 -- overriding of interface primitives (and thus factorize calls to
2418 -- Check_Abstract_Overriding located at different contexts in the
2419 -- compiler). However, this is not possible because it causes
2420 -- spurious errors in case of late overriding.
2422 Add_Internal_Interface_Entities (E);
2427 if Ekind (E) = E_Record_Type
2428 and then Is_CPP_Class (E)
2429 and then Is_Tagged_Type (E)
2430 and then Tagged_Type_Expansion
2431 and then Expander_Active
2433 if CPP_Num_Prims (E) = 0 then
2435 -- If the CPP type has user defined components then it must import
2436 -- primitives from C++. This is required because if the C++ class
2437 -- has no primitives then the C++ compiler does not added the _tag
2438 -- component to the type.
2440 pragma Assert (Chars (First_Entity (E)) = Name_uTag);
2442 if First_Entity (E) /= Last_Entity (E) then
2444 ("?'C'P'P type must import at least one primitive from C++",
2449 -- Check that all its primitives are abstract or imported from C++.
2450 -- Check also availability of the C++ constructor.
2453 Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
2455 Error_Reported : Boolean := False;
2459 Elmt := First_Elmt (Primitive_Operations (E));
2460 while Present (Elmt) loop
2461 Prim := Node (Elmt);
2463 if Comes_From_Source (Prim) then
2464 if Is_Abstract_Subprogram (Prim) then
2467 elsif not Is_Imported (Prim)
2468 or else Convention (Prim) /= Convention_CPP
2471 ("?primitives of 'C'P'P types must be imported from C++"
2472 & " or abstract", Prim);
2474 elsif not Has_Constructors
2475 and then not Error_Reported
2477 Error_Msg_Name_1 := Chars (E);
2479 ("?'C'P'P constructor required for type %", Prim);
2480 Error_Reported := True;
2488 end Analyze_Freeze_Entity;
2490 ------------------------------------------
2491 -- Analyze_Record_Representation_Clause --
2492 ------------------------------------------
2494 -- Note: we check as much as we can here, but we can't do any checks
2495 -- based on the position values (e.g. overlap checks) until freeze time
2496 -- because especially in Ada 2005 (machine scalar mode), the processing
2497 -- for non-standard bit order can substantially change the positions.
2498 -- See procedure Check_Record_Representation_Clause (called from Freeze)
2499 -- for the remainder of this processing.
2501 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2502 Ident : constant Node_Id := Identifier (N);
2503 Rectype : Entity_Id;
2508 Hbit : Uint := Uint_0;
2513 CR_Pragma : Node_Id := Empty;
2514 -- Points to N_Pragma node if Complete_Representation pragma present
2517 if Ignore_Rep_Clauses then
2522 Rectype := Entity (Ident);
2524 if Rectype = Any_Type
2525 or else Rep_Item_Too_Early (Rectype, N)
2529 Rectype := Underlying_Type (Rectype);
2532 -- First some basic error checks
2534 if not Is_Record_Type (Rectype) then
2536 ("record type required, found}", Ident, First_Subtype (Rectype));
2539 elsif Is_Unchecked_Union (Rectype) then
2541 ("record rep clause not allowed for Unchecked_Union", N);
2543 elsif Scope (Rectype) /= Current_Scope then
2544 Error_Msg_N ("type must be declared in this scope", N);
2547 elsif not Is_First_Subtype (Rectype) then
2548 Error_Msg_N ("cannot give record rep clause for subtype", N);
2551 elsif Has_Record_Rep_Clause (Rectype) then
2552 Error_Msg_N ("duplicate record rep clause ignored", N);
2555 elsif Rep_Item_Too_Late (Rectype, N) then
2559 if Present (Mod_Clause (N)) then
2561 Loc : constant Source_Ptr := Sloc (N);
2562 M : constant Node_Id := Mod_Clause (N);
2563 P : constant List_Id := Pragmas_Before (M);
2567 pragma Warnings (Off, Mod_Val);
2570 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2572 if Warn_On_Obsolescent_Feature then
2574 ("mod clause is an obsolescent feature (RM J.8)?", N);
2576 ("\use alignment attribute definition clause instead?", N);
2583 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2584 -- the Mod clause into an alignment clause anyway, so that the
2585 -- back-end can compute and back-annotate properly the size and
2586 -- alignment of types that may include this record.
2588 -- This seems dubious, this destroys the source tree in a manner
2589 -- not detectable by ASIS ???
2591 if Operating_Mode = Check_Semantics
2595 Make_Attribute_Definition_Clause (Loc,
2596 Name => New_Reference_To (Base_Type (Rectype), Loc),
2597 Chars => Name_Alignment,
2598 Expression => Relocate_Node (Expression (M)));
2600 Set_From_At_Mod (AtM_Nod);
2601 Insert_After (N, AtM_Nod);
2602 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2603 Set_Mod_Clause (N, Empty);
2606 -- Get the alignment value to perform error checking
2608 Mod_Val := Get_Alignment_Value (Expression (M));
2613 -- For untagged types, clear any existing component clauses for the
2614 -- type. If the type is derived, this is what allows us to override
2615 -- a rep clause for the parent. For type extensions, the representation
2616 -- of the inherited components is inherited, so we want to keep previous
2617 -- component clauses for completeness.
2619 if not Is_Tagged_Type (Rectype) then
2620 Comp := First_Component_Or_Discriminant (Rectype);
2621 while Present (Comp) loop
2622 Set_Component_Clause (Comp, Empty);
2623 Next_Component_Or_Discriminant (Comp);
2627 -- All done if no component clauses
2629 CC := First (Component_Clauses (N));
2635 -- A representation like this applies to the base type
2637 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2638 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2639 Set_Has_Specified_Layout (Base_Type (Rectype));
2641 -- Process the component clauses
2643 while Present (CC) loop
2647 if Nkind (CC) = N_Pragma then
2650 -- The only pragma of interest is Complete_Representation
2652 if Pragma_Name (CC) = Name_Complete_Representation then
2656 -- Processing for real component clause
2659 Posit := Static_Integer (Position (CC));
2660 Fbit := Static_Integer (First_Bit (CC));
2661 Lbit := Static_Integer (Last_Bit (CC));
2664 and then Fbit /= No_Uint
2665 and then Lbit /= No_Uint
2669 ("position cannot be negative", Position (CC));
2673 ("first bit cannot be negative", First_Bit (CC));
2675 -- The Last_Bit specified in a component clause must not be
2676 -- less than the First_Bit minus one (RM-13.5.1(10)).
2678 elsif Lbit < Fbit - 1 then
2680 ("last bit cannot be less than first bit minus one",
2683 -- Values look OK, so find the corresponding record component
2684 -- Even though the syntax allows an attribute reference for
2685 -- implementation-defined components, GNAT does not allow the
2686 -- tag to get an explicit position.
2688 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2689 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2690 Error_Msg_N ("position of tag cannot be specified", CC);
2692 Error_Msg_N ("illegal component name", CC);
2696 Comp := First_Entity (Rectype);
2697 while Present (Comp) loop
2698 exit when Chars (Comp) = Chars (Component_Name (CC));
2704 -- Maybe component of base type that is absent from
2705 -- statically constrained first subtype.
2707 Comp := First_Entity (Base_Type (Rectype));
2708 while Present (Comp) loop
2709 exit when Chars (Comp) = Chars (Component_Name (CC));
2716 ("component clause is for non-existent field", CC);
2718 elsif Present (Component_Clause (Comp)) then
2720 -- Diagnose duplicate rep clause, or check consistency
2721 -- if this is an inherited component. In a double fault,
2722 -- there may be a duplicate inconsistent clause for an
2723 -- inherited component.
2725 if Scope (Original_Record_Component (Comp)) = Rectype
2726 or else Parent (Component_Clause (Comp)) = N
2728 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2729 Error_Msg_N ("component clause previously given#", CC);
2733 Rep1 : constant Node_Id := Component_Clause (Comp);
2735 if Intval (Position (Rep1)) /=
2736 Intval (Position (CC))
2737 or else Intval (First_Bit (Rep1)) /=
2738 Intval (First_Bit (CC))
2739 or else Intval (Last_Bit (Rep1)) /=
2740 Intval (Last_Bit (CC))
2742 Error_Msg_N ("component clause inconsistent "
2743 & "with representation of ancestor", CC);
2744 elsif Warn_On_Redundant_Constructs then
2745 Error_Msg_N ("?redundant component clause "
2746 & "for inherited component!", CC);
2751 -- Normal case where this is the first component clause we
2752 -- have seen for this entity, so set it up properly.
2755 -- Make reference for field in record rep clause and set
2756 -- appropriate entity field in the field identifier.
2759 (Comp, Component_Name (CC), Set_Ref => False);
2760 Set_Entity (Component_Name (CC), Comp);
2762 -- Update Fbit and Lbit to the actual bit number
2764 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2765 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2767 if Has_Size_Clause (Rectype)
2768 and then Esize (Rectype) <= Lbit
2771 ("bit number out of range of specified size",
2774 Set_Component_Clause (Comp, CC);
2775 Set_Component_Bit_Offset (Comp, Fbit);
2776 Set_Esize (Comp, 1 + (Lbit - Fbit));
2777 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2778 Set_Normalized_Position (Comp, Fbit / SSU);
2780 if Warn_On_Overridden_Size
2781 and then Has_Size_Clause (Etype (Comp))
2782 and then RM_Size (Etype (Comp)) /= Esize (Comp)
2785 ("?component size overrides size clause for&",
2786 Component_Name (CC), Etype (Comp));
2789 -- This information is also set in the corresponding
2790 -- component of the base type, found by accessing the
2791 -- Original_Record_Component link if it is present.
2793 Ocomp := Original_Record_Component (Comp);
2800 (Component_Name (CC),
2806 (Comp, First_Node (CC), "component clause", Biased);
2808 if Present (Ocomp) then
2809 Set_Component_Clause (Ocomp, CC);
2810 Set_Component_Bit_Offset (Ocomp, Fbit);
2811 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2812 Set_Normalized_Position (Ocomp, Fbit / SSU);
2813 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2815 Set_Normalized_Position_Max
2816 (Ocomp, Normalized_Position (Ocomp));
2818 -- Note: we don't use Set_Biased here, because we
2819 -- already gave a warning above if needed, and we
2820 -- would get a duplicate for the same name here.
2822 Set_Has_Biased_Representation
2823 (Ocomp, Has_Biased_Representation (Comp));
2826 if Esize (Comp) < 0 then
2827 Error_Msg_N ("component size is negative", CC);
2838 -- Check missing components if Complete_Representation pragma appeared
2840 if Present (CR_Pragma) then
2841 Comp := First_Component_Or_Discriminant (Rectype);
2842 while Present (Comp) loop
2843 if No (Component_Clause (Comp)) then
2845 ("missing component clause for &", CR_Pragma, Comp);
2848 Next_Component_Or_Discriminant (Comp);
2851 -- If no Complete_Representation pragma, warn if missing components
2853 elsif Warn_On_Unrepped_Components then
2855 Num_Repped_Components : Nat := 0;
2856 Num_Unrepped_Components : Nat := 0;
2859 -- First count number of repped and unrepped components
2861 Comp := First_Component_Or_Discriminant (Rectype);
2862 while Present (Comp) loop
2863 if Present (Component_Clause (Comp)) then
2864 Num_Repped_Components := Num_Repped_Components + 1;
2866 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2869 Next_Component_Or_Discriminant (Comp);
2872 -- We are only interested in the case where there is at least one
2873 -- unrepped component, and at least half the components have rep
2874 -- clauses. We figure that if less than half have them, then the
2875 -- partial rep clause is really intentional. If the component
2876 -- type has no underlying type set at this point (as for a generic
2877 -- formal type), we don't know enough to give a warning on the
2880 if Num_Unrepped_Components > 0
2881 and then Num_Unrepped_Components < Num_Repped_Components
2883 Comp := First_Component_Or_Discriminant (Rectype);
2884 while Present (Comp) loop
2885 if No (Component_Clause (Comp))
2886 and then Comes_From_Source (Comp)
2887 and then Present (Underlying_Type (Etype (Comp)))
2888 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2889 or else Size_Known_At_Compile_Time
2890 (Underlying_Type (Etype (Comp))))
2891 and then not Has_Warnings_Off (Rectype)
2893 Error_Msg_Sloc := Sloc (Comp);
2895 ("?no component clause given for & declared #",
2899 Next_Component_Or_Discriminant (Comp);
2904 end Analyze_Record_Representation_Clause;
2906 -----------------------------------
2907 -- Check_Constant_Address_Clause --
2908 -----------------------------------
2910 procedure Check_Constant_Address_Clause
2914 procedure Check_At_Constant_Address (Nod : Node_Id);
2915 -- Checks that the given node N represents a name whose 'Address is
2916 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2917 -- address value is the same at the point of declaration of U_Ent and at
2918 -- the time of elaboration of the address clause.
2920 procedure Check_Expr_Constants (Nod : Node_Id);
2921 -- Checks that Nod meets the requirements for a constant address clause
2922 -- in the sense of the enclosing procedure.
2924 procedure Check_List_Constants (Lst : List_Id);
2925 -- Check that all elements of list Lst meet the requirements for a
2926 -- constant address clause in the sense of the enclosing procedure.
2928 -------------------------------
2929 -- Check_At_Constant_Address --
2930 -------------------------------
2932 procedure Check_At_Constant_Address (Nod : Node_Id) is
2934 if Is_Entity_Name (Nod) then
2935 if Present (Address_Clause (Entity ((Nod)))) then
2937 ("invalid address clause for initialized object &!",
2940 ("address for& cannot" &
2941 " depend on another address clause! (RM 13.1(22))!",
2944 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2945 and then Sloc (U_Ent) < Sloc (Entity (Nod))
2948 ("invalid address clause for initialized object &!",
2950 Error_Msg_Node_2 := U_Ent;
2952 ("\& must be defined before & (RM 13.1(22))!",
2956 elsif Nkind (Nod) = N_Selected_Component then
2958 T : constant Entity_Id := Etype (Prefix (Nod));
2961 if (Is_Record_Type (T)
2962 and then Has_Discriminants (T))
2965 and then Is_Record_Type (Designated_Type (T))
2966 and then Has_Discriminants (Designated_Type (T)))
2969 ("invalid address clause for initialized object &!",
2972 ("\address cannot depend on component" &
2973 " of discriminated record (RM 13.1(22))!",
2976 Check_At_Constant_Address (Prefix (Nod));
2980 elsif Nkind (Nod) = N_Indexed_Component then
2981 Check_At_Constant_Address (Prefix (Nod));
2982 Check_List_Constants (Expressions (Nod));
2985 Check_Expr_Constants (Nod);
2987 end Check_At_Constant_Address;
2989 --------------------------
2990 -- Check_Expr_Constants --
2991 --------------------------
2993 procedure Check_Expr_Constants (Nod : Node_Id) is
2994 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
2995 Ent : Entity_Id := Empty;
2998 if Nkind (Nod) in N_Has_Etype
2999 and then Etype (Nod) = Any_Type
3005 when N_Empty | N_Error =>
3008 when N_Identifier | N_Expanded_Name =>
3009 Ent := Entity (Nod);
3011 -- We need to look at the original node if it is different
3012 -- from the node, since we may have rewritten things and
3013 -- substituted an identifier representing the rewrite.
3015 if Original_Node (Nod) /= Nod then
3016 Check_Expr_Constants (Original_Node (Nod));
3018 -- If the node is an object declaration without initial
3019 -- value, some code has been expanded, and the expression
3020 -- is not constant, even if the constituents might be
3021 -- acceptable, as in A'Address + offset.
3023 if Ekind (Ent) = E_Variable
3025 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3027 No (Expression (Declaration_Node (Ent)))
3030 ("invalid address clause for initialized object &!",
3033 -- If entity is constant, it may be the result of expanding
3034 -- a check. We must verify that its declaration appears
3035 -- before the object in question, else we also reject the
3038 elsif Ekind (Ent) = E_Constant
3039 and then In_Same_Source_Unit (Ent, U_Ent)
3040 and then Sloc (Ent) > Loc_U_Ent
3043 ("invalid address clause for initialized object &!",
3050 -- Otherwise look at the identifier and see if it is OK
3052 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
3053 or else Is_Type (Ent)
3058 Ekind (Ent) = E_Constant
3060 Ekind (Ent) = E_In_Parameter
3062 -- This is the case where we must have Ent defined before
3063 -- U_Ent. Clearly if they are in different units this
3064 -- requirement is met since the unit containing Ent is
3065 -- already processed.
3067 if not In_Same_Source_Unit (Ent, U_Ent) then
3070 -- Otherwise location of Ent must be before the location
3071 -- of U_Ent, that's what prior defined means.
3073 elsif Sloc (Ent) < Loc_U_Ent then
3078 ("invalid address clause for initialized object &!",
3080 Error_Msg_Node_2 := U_Ent;
3082 ("\& must be defined before & (RM 13.1(22))!",
3086 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3087 Check_Expr_Constants (Original_Node (Nod));
3091 ("invalid address clause for initialized object &!",
3094 if Comes_From_Source (Ent) then
3096 ("\reference to variable& not allowed"
3097 & " (RM 13.1(22))!", Nod, Ent);
3100 ("non-static expression not allowed"
3101 & " (RM 13.1(22))!", Nod);
3105 when N_Integer_Literal =>
3107 -- If this is a rewritten unchecked conversion, in a system
3108 -- where Address is an integer type, always use the base type
3109 -- for a literal value. This is user-friendly and prevents
3110 -- order-of-elaboration issues with instances of unchecked
3113 if Nkind (Original_Node (Nod)) = N_Function_Call then
3114 Set_Etype (Nod, Base_Type (Etype (Nod)));
3117 when N_Real_Literal |
3119 N_Character_Literal =>
3123 Check_Expr_Constants (Low_Bound (Nod));
3124 Check_Expr_Constants (High_Bound (Nod));
3126 when N_Explicit_Dereference =>
3127 Check_Expr_Constants (Prefix (Nod));
3129 when N_Indexed_Component =>
3130 Check_Expr_Constants (Prefix (Nod));
3131 Check_List_Constants (Expressions (Nod));
3134 Check_Expr_Constants (Prefix (Nod));
3135 Check_Expr_Constants (Discrete_Range (Nod));
3137 when N_Selected_Component =>
3138 Check_Expr_Constants (Prefix (Nod));
3140 when N_Attribute_Reference =>
3141 if Attribute_Name (Nod) = Name_Address
3143 Attribute_Name (Nod) = Name_Access
3145 Attribute_Name (Nod) = Name_Unchecked_Access
3147 Attribute_Name (Nod) = Name_Unrestricted_Access
3149 Check_At_Constant_Address (Prefix (Nod));
3152 Check_Expr_Constants (Prefix (Nod));
3153 Check_List_Constants (Expressions (Nod));
3157 Check_List_Constants (Component_Associations (Nod));
3158 Check_List_Constants (Expressions (Nod));
3160 when N_Component_Association =>
3161 Check_Expr_Constants (Expression (Nod));
3163 when N_Extension_Aggregate =>
3164 Check_Expr_Constants (Ancestor_Part (Nod));
3165 Check_List_Constants (Component_Associations (Nod));
3166 Check_List_Constants (Expressions (Nod));
3171 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3172 Check_Expr_Constants (Left_Opnd (Nod));
3173 Check_Expr_Constants (Right_Opnd (Nod));
3176 Check_Expr_Constants (Right_Opnd (Nod));
3178 when N_Type_Conversion |
3179 N_Qualified_Expression |
3181 Check_Expr_Constants (Expression (Nod));
3183 when N_Unchecked_Type_Conversion =>
3184 Check_Expr_Constants (Expression (Nod));
3186 -- If this is a rewritten unchecked conversion, subtypes in
3187 -- this node are those created within the instance. To avoid
3188 -- order of elaboration issues, replace them with their base
3189 -- types. Note that address clauses can cause order of
3190 -- elaboration problems because they are elaborated by the
3191 -- back-end at the point of definition, and may mention
3192 -- entities declared in between (as long as everything is
3193 -- static). It is user-friendly to allow unchecked conversions
3196 if Nkind (Original_Node (Nod)) = N_Function_Call then
3197 Set_Etype (Expression (Nod),
3198 Base_Type (Etype (Expression (Nod))));
3199 Set_Etype (Nod, Base_Type (Etype (Nod)));
3202 when N_Function_Call =>
3203 if not Is_Pure (Entity (Name (Nod))) then
3205 ("invalid address clause for initialized object &!",
3209 ("\function & is not pure (RM 13.1(22))!",
3210 Nod, Entity (Name (Nod)));
3213 Check_List_Constants (Parameter_Associations (Nod));
3216 when N_Parameter_Association =>
3217 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3221 ("invalid address clause for initialized object &!",
3224 ("\must be constant defined before& (RM 13.1(22))!",
3227 end Check_Expr_Constants;
3229 --------------------------
3230 -- Check_List_Constants --
3231 --------------------------
3233 procedure Check_List_Constants (Lst : List_Id) is
3237 if Present (Lst) then
3238 Nod1 := First (Lst);
3239 while Present (Nod1) loop
3240 Check_Expr_Constants (Nod1);
3244 end Check_List_Constants;
3246 -- Start of processing for Check_Constant_Address_Clause
3249 -- If rep_clauses are to be ignored, no need for legality checks. In
3250 -- particular, no need to pester user about rep clauses that violate
3251 -- the rule on constant addresses, given that these clauses will be
3252 -- removed by Freeze before they reach the back end.
3254 if not Ignore_Rep_Clauses then
3255 Check_Expr_Constants (Expr);
3257 end Check_Constant_Address_Clause;
3259 ----------------------------------------
3260 -- Check_Record_Representation_Clause --
3261 ----------------------------------------
3263 procedure Check_Record_Representation_Clause (N : Node_Id) is
3264 Loc : constant Source_Ptr := Sloc (N);
3265 Ident : constant Node_Id := Identifier (N);
3266 Rectype : Entity_Id;
3271 Hbit : Uint := Uint_0;
3275 Max_Bit_So_Far : Uint;
3276 -- Records the maximum bit position so far. If all field positions
3277 -- are monotonically increasing, then we can skip the circuit for
3278 -- checking for overlap, since no overlap is possible.
3280 Tagged_Parent : Entity_Id := Empty;
3281 -- This is set in the case of a derived tagged type for which we have
3282 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
3283 -- positioned by record representation clauses). In this case we must
3284 -- check for overlap between components of this tagged type, and the
3285 -- components of its parent. Tagged_Parent will point to this parent
3286 -- type. For all other cases Tagged_Parent is left set to Empty.
3288 Parent_Last_Bit : Uint;
3289 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
3290 -- last bit position for any field in the parent type. We only need to
3291 -- check overlap for fields starting below this point.
3293 Overlap_Check_Required : Boolean;
3294 -- Used to keep track of whether or not an overlap check is required
3296 Overlap_Detected : Boolean := False;
3297 -- Set True if an overlap is detected
3299 Ccount : Natural := 0;
3300 -- Number of component clauses in record rep clause
3302 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
3303 -- Given two entities for record components or discriminants, checks
3304 -- if they have overlapping component clauses and issues errors if so.
3306 procedure Find_Component;
3307 -- Finds component entity corresponding to current component clause (in
3308 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
3309 -- start/stop bits for the field. If there is no matching component or
3310 -- if the matching component does not have a component clause, then
3311 -- that's an error and Comp is set to Empty, but no error message is
3312 -- issued, since the message was already given. Comp is also set to
3313 -- Empty if the current "component clause" is in fact a pragma.
3315 -----------------------------
3316 -- Check_Component_Overlap --
3317 -----------------------------
3319 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
3320 CC1 : constant Node_Id := Component_Clause (C1_Ent);
3321 CC2 : constant Node_Id := Component_Clause (C2_Ent);
3324 if Present (CC1) and then Present (CC2) then
3326 -- Exclude odd case where we have two tag fields in the same
3327 -- record, both at location zero. This seems a bit strange, but
3328 -- it seems to happen in some circumstances, perhaps on an error.
3330 if Chars (C1_Ent) = Name_uTag
3332 Chars (C2_Ent) = Name_uTag
3337 -- Here we check if the two fields overlap
3340 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
3341 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
3342 E1 : constant Uint := S1 + Esize (C1_Ent);
3343 E2 : constant Uint := S2 + Esize (C2_Ent);
3346 if E2 <= S1 or else E1 <= S2 then
3349 Error_Msg_Node_2 := Component_Name (CC2);
3350 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
3351 Error_Msg_Node_1 := Component_Name (CC1);
3353 ("component& overlaps & #", Component_Name (CC1));
3354 Overlap_Detected := True;
3358 end Check_Component_Overlap;
3360 --------------------
3361 -- Find_Component --
3362 --------------------
3364 procedure Find_Component is
3366 procedure Search_Component (R : Entity_Id);
3367 -- Search components of R for a match. If found, Comp is set.
3369 ----------------------
3370 -- Search_Component --
3371 ----------------------
3373 procedure Search_Component (R : Entity_Id) is
3375 Comp := First_Component_Or_Discriminant (R);
3376 while Present (Comp) loop
3378 -- Ignore error of attribute name for component name (we
3379 -- already gave an error message for this, so no need to
3382 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
3385 exit when Chars (Comp) = Chars (Component_Name (CC));
3388 Next_Component_Or_Discriminant (Comp);
3390 end Search_Component;
3392 -- Start of processing for Find_Component
3395 -- Return with Comp set to Empty if we have a pragma
3397 if Nkind (CC) = N_Pragma then
3402 -- Search current record for matching component
3404 Search_Component (Rectype);
3406 -- If not found, maybe component of base type that is absent from
3407 -- statically constrained first subtype.
3410 Search_Component (Base_Type (Rectype));
3413 -- If no component, or the component does not reference the component
3414 -- clause in question, then there was some previous error for which
3415 -- we already gave a message, so just return with Comp Empty.
3418 or else Component_Clause (Comp) /= CC
3422 -- Normal case where we have a component clause
3425 Fbit := Component_Bit_Offset (Comp);
3426 Lbit := Fbit + Esize (Comp) - 1;
3430 -- Start of processing for Check_Record_Representation_Clause
3434 Rectype := Entity (Ident);
3436 if Rectype = Any_Type then
3439 Rectype := Underlying_Type (Rectype);
3442 -- See if we have a fully repped derived tagged type
3445 PS : constant Entity_Id := Parent_Subtype (Rectype);
3448 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
3449 Tagged_Parent := PS;
3451 -- Find maximum bit of any component of the parent type
3453 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
3454 Pcomp := First_Entity (Tagged_Parent);
3455 while Present (Pcomp) loop
3456 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
3457 if Component_Bit_Offset (Pcomp) /= No_Uint
3458 and then Known_Static_Esize (Pcomp)
3463 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
3466 Next_Entity (Pcomp);
3472 -- All done if no component clauses
3474 CC := First (Component_Clauses (N));
3480 -- If a tag is present, then create a component clause that places it
3481 -- at the start of the record (otherwise gigi may place it after other
3482 -- fields that have rep clauses).
3484 Fent := First_Entity (Rectype);
3486 if Nkind (Fent) = N_Defining_Identifier
3487 and then Chars (Fent) = Name_uTag
3489 Set_Component_Bit_Offset (Fent, Uint_0);
3490 Set_Normalized_Position (Fent, Uint_0);
3491 Set_Normalized_First_Bit (Fent, Uint_0);
3492 Set_Normalized_Position_Max (Fent, Uint_0);
3493 Init_Esize (Fent, System_Address_Size);
3495 Set_Component_Clause (Fent,
3496 Make_Component_Clause (Loc,
3498 Make_Identifier (Loc,
3499 Chars => Name_uTag),
3502 Make_Integer_Literal (Loc,
3506 Make_Integer_Literal (Loc,
3510 Make_Integer_Literal (Loc,
3511 UI_From_Int (System_Address_Size))));
3513 Ccount := Ccount + 1;
3516 Max_Bit_So_Far := Uint_Minus_1;
3517 Overlap_Check_Required := False;
3519 -- Process the component clauses
3521 while Present (CC) loop
3524 if Present (Comp) then
3525 Ccount := Ccount + 1;
3527 -- We need a full overlap check if record positions non-monotonic
3529 if Fbit <= Max_Bit_So_Far then
3530 Overlap_Check_Required := True;
3533 Max_Bit_So_Far := Lbit;
3535 -- Check bit position out of range of specified size
3537 if Has_Size_Clause (Rectype)
3538 and then Esize (Rectype) <= Lbit
3541 ("bit number out of range of specified size",
3544 -- Check for overlap with tag field
3547 if Is_Tagged_Type (Rectype)
3548 and then Fbit < System_Address_Size
3551 ("component overlaps tag field of&",
3552 Component_Name (CC), Rectype);
3553 Overlap_Detected := True;
3561 -- Check parent overlap if component might overlap parent field
3563 if Present (Tagged_Parent)
3564 and then Fbit <= Parent_Last_Bit
3566 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
3567 while Present (Pcomp) loop
3568 if not Is_Tag (Pcomp)
3569 and then Chars (Pcomp) /= Name_uParent
3571 Check_Component_Overlap (Comp, Pcomp);
3574 Next_Component_Or_Discriminant (Pcomp);
3582 -- Now that we have processed all the component clauses, check for
3583 -- overlap. We have to leave this till last, since the components can
3584 -- appear in any arbitrary order in the representation clause.
3586 -- We do not need this check if all specified ranges were monotonic,
3587 -- as recorded by Overlap_Check_Required being False at this stage.
3589 -- This first section checks if there are any overlapping entries at
3590 -- all. It does this by sorting all entries and then seeing if there are
3591 -- any overlaps. If there are none, then that is decisive, but if there
3592 -- are overlaps, they may still be OK (they may result from fields in
3593 -- different variants).
3595 if Overlap_Check_Required then
3596 Overlap_Check1 : declare
3598 OC_Fbit : array (0 .. Ccount) of Uint;
3599 -- First-bit values for component clauses, the value is the offset
3600 -- of the first bit of the field from start of record. The zero
3601 -- entry is for use in sorting.
3603 OC_Lbit : array (0 .. Ccount) of Uint;
3604 -- Last-bit values for component clauses, the value is the offset
3605 -- of the last bit of the field from start of record. The zero
3606 -- entry is for use in sorting.
3608 OC_Count : Natural := 0;
3609 -- Count of entries in OC_Fbit and OC_Lbit
3611 function OC_Lt (Op1, Op2 : Natural) return Boolean;
3612 -- Compare routine for Sort
3614 procedure OC_Move (From : Natural; To : Natural);
3615 -- Move routine for Sort
3617 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
3623 function OC_Lt (Op1, Op2 : Natural) return Boolean is
3625 return OC_Fbit (Op1) < OC_Fbit (Op2);
3632 procedure OC_Move (From : Natural; To : Natural) is
3634 OC_Fbit (To) := OC_Fbit (From);
3635 OC_Lbit (To) := OC_Lbit (From);
3638 -- Start of processing for Overlap_Check
3641 CC := First (Component_Clauses (N));
3642 while Present (CC) loop
3644 -- Exclude component clause already marked in error
3646 if not Error_Posted (CC) then
3649 if Present (Comp) then
3650 OC_Count := OC_Count + 1;
3651 OC_Fbit (OC_Count) := Fbit;
3652 OC_Lbit (OC_Count) := Lbit;
3659 Sorting.Sort (OC_Count);
3661 Overlap_Check_Required := False;
3662 for J in 1 .. OC_Count - 1 loop
3663 if OC_Lbit (J) >= OC_Fbit (J + 1) then
3664 Overlap_Check_Required := True;
3671 -- If Overlap_Check_Required is still True, then we have to do the full
3672 -- scale overlap check, since we have at least two fields that do
3673 -- overlap, and we need to know if that is OK since they are in
3674 -- different variant, or whether we have a definite problem.
3676 if Overlap_Check_Required then
3677 Overlap_Check2 : declare
3678 C1_Ent, C2_Ent : Entity_Id;
3679 -- Entities of components being checked for overlap
3682 -- Component_List node whose Component_Items are being checked
3685 -- Component declaration for component being checked
3688 C1_Ent := First_Entity (Base_Type (Rectype));
3690 -- Loop through all components in record. For each component check
3691 -- for overlap with any of the preceding elements on the component
3692 -- list containing the component and also, if the component is in
3693 -- a variant, check against components outside the case structure.
3694 -- This latter test is repeated recursively up the variant tree.
3696 Main_Component_Loop : while Present (C1_Ent) loop
3697 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
3698 goto Continue_Main_Component_Loop;
3701 -- Skip overlap check if entity has no declaration node. This
3702 -- happens with discriminants in constrained derived types.
3703 -- Possibly we are missing some checks as a result, but that
3704 -- does not seem terribly serious.
3706 if No (Declaration_Node (C1_Ent)) then
3707 goto Continue_Main_Component_Loop;
3710 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
3712 -- Loop through component lists that need checking. Check the
3713 -- current component list and all lists in variants above us.
3715 Component_List_Loop : loop
3717 -- If derived type definition, go to full declaration
3718 -- If at outer level, check discriminants if there are any.
3720 if Nkind (Clist) = N_Derived_Type_Definition then
3721 Clist := Parent (Clist);
3724 -- Outer level of record definition, check discriminants
3726 if Nkind_In (Clist, N_Full_Type_Declaration,
3727 N_Private_Type_Declaration)
3729 if Has_Discriminants (Defining_Identifier (Clist)) then
3731 First_Discriminant (Defining_Identifier (Clist));
3732 while Present (C2_Ent) loop
3733 exit when C1_Ent = C2_Ent;
3734 Check_Component_Overlap (C1_Ent, C2_Ent);
3735 Next_Discriminant (C2_Ent);
3739 -- Record extension case
3741 elsif Nkind (Clist) = N_Derived_Type_Definition then
3744 -- Otherwise check one component list
3747 Citem := First (Component_Items (Clist));
3748 while Present (Citem) loop
3749 if Nkind (Citem) = N_Component_Declaration then
3750 C2_Ent := Defining_Identifier (Citem);
3751 exit when C1_Ent = C2_Ent;
3752 Check_Component_Overlap (C1_Ent, C2_Ent);
3759 -- Check for variants above us (the parent of the Clist can
3760 -- be a variant, in which case its parent is a variant part,
3761 -- and the parent of the variant part is a component list
3762 -- whose components must all be checked against the current
3763 -- component for overlap).
3765 if Nkind (Parent (Clist)) = N_Variant then
3766 Clist := Parent (Parent (Parent (Clist)));
3768 -- Check for possible discriminant part in record, this
3769 -- is treated essentially as another level in the
3770 -- recursion. For this case the parent of the component
3771 -- list is the record definition, and its parent is the
3772 -- full type declaration containing the discriminant
3775 elsif Nkind (Parent (Clist)) = N_Record_Definition then
3776 Clist := Parent (Parent ((Clist)));
3778 -- If neither of these two cases, we are at the top of
3782 exit Component_List_Loop;
3784 end loop Component_List_Loop;
3786 <<Continue_Main_Component_Loop>>
3787 Next_Entity (C1_Ent);
3789 end loop Main_Component_Loop;
3793 -- The following circuit deals with warning on record holes (gaps). We
3794 -- skip this check if overlap was detected, since it makes sense for the
3795 -- programmer to fix this illegality before worrying about warnings.
3797 if not Overlap_Detected and Warn_On_Record_Holes then
3798 Record_Hole_Check : declare
3799 Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype));
3800 -- Full declaration of record type
3802 procedure Check_Component_List
3806 -- Check component list CL for holes. The starting bit should be
3807 -- Sbit. which is zero for the main record component list and set
3808 -- appropriately for recursive calls for variants. DS is set to
3809 -- a list of discriminant specifications to be included in the
3810 -- consideration of components. It is No_List if none to consider.
3812 --------------------------
3813 -- Check_Component_List --
3814 --------------------------
3816 procedure Check_Component_List
3824 Compl := Integer (List_Length (Component_Items (CL)));
3826 if DS /= No_List then
3827 Compl := Compl + Integer (List_Length (DS));
3831 Comps : array (Natural range 0 .. Compl) of Entity_Id;
3832 -- Gather components (zero entry is for sort routine)
3834 Ncomps : Natural := 0;
3835 -- Number of entries stored in Comps (starting at Comps (1))
3838 -- One component item or discriminant specification
3841 -- Starting bit for next component
3849 function Lt (Op1, Op2 : Natural) return Boolean;
3850 -- Compare routine for Sort
3852 procedure Move (From : Natural; To : Natural);
3853 -- Move routine for Sort
3855 package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
3861 function Lt (Op1, Op2 : Natural) return Boolean is
3863 return Component_Bit_Offset (Comps (Op1))
3865 Component_Bit_Offset (Comps (Op2));
3872 procedure Move (From : Natural; To : Natural) is
3874 Comps (To) := Comps (From);
3878 -- Gather discriminants into Comp
3880 if DS /= No_List then
3881 Citem := First (DS);
3882 while Present (Citem) loop
3883 if Nkind (Citem) = N_Discriminant_Specification then
3885 Ent : constant Entity_Id :=
3886 Defining_Identifier (Citem);
3888 if Ekind (Ent) = E_Discriminant then
3889 Ncomps := Ncomps + 1;
3890 Comps (Ncomps) := Ent;
3899 -- Gather component entities into Comp
3901 Citem := First (Component_Items (CL));
3902 while Present (Citem) loop
3903 if Nkind (Citem) = N_Component_Declaration then
3904 Ncomps := Ncomps + 1;
3905 Comps (Ncomps) := Defining_Identifier (Citem);
3911 -- Now sort the component entities based on the first bit.
3912 -- Note we already know there are no overlapping components.
3914 Sorting.Sort (Ncomps);
3916 -- Loop through entries checking for holes
3919 for J in 1 .. Ncomps loop
3921 Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
3923 if Error_Msg_Uint_1 > 0 then
3925 ("?^-bit gap before component&",
3926 Component_Name (Component_Clause (CEnt)), CEnt);
3929 Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
3932 -- Process variant parts recursively if present
3934 if Present (Variant_Part (CL)) then
3935 Variant := First (Variants (Variant_Part (CL)));
3936 while Present (Variant) loop
3937 Check_Component_List
3938 (Component_List (Variant), Nbit, No_List);
3943 end Check_Component_List;
3945 -- Start of processing for Record_Hole_Check
3952 if Is_Tagged_Type (Rectype) then
3953 Sbit := UI_From_Int (System_Address_Size);
3958 if Nkind (Decl) = N_Full_Type_Declaration
3959 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
3961 Check_Component_List
3962 (Component_List (Type_Definition (Decl)),
3964 Discriminant_Specifications (Decl));
3967 end Record_Hole_Check;
3970 -- For records that have component clauses for all components, and whose
3971 -- size is less than or equal to 32, we need to know the size in the
3972 -- front end to activate possible packed array processing where the
3973 -- component type is a record.
3975 -- At this stage Hbit + 1 represents the first unused bit from all the
3976 -- component clauses processed, so if the component clauses are
3977 -- complete, then this is the length of the record.
3979 -- For records longer than System.Storage_Unit, and for those where not
3980 -- all components have component clauses, the back end determines the
3981 -- length (it may for example be appropriate to round up the size
3982 -- to some convenient boundary, based on alignment considerations, etc).
3984 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
3986 -- Nothing to do if at least one component has no component clause
3988 Comp := First_Component_Or_Discriminant (Rectype);
3989 while Present (Comp) loop
3990 exit when No (Component_Clause (Comp));
3991 Next_Component_Or_Discriminant (Comp);
3994 -- If we fall out of loop, all components have component clauses
3995 -- and so we can set the size to the maximum value.
3998 Set_RM_Size (Rectype, Hbit + 1);
4001 end Check_Record_Representation_Clause;
4007 procedure Check_Size
4011 Biased : out Boolean)
4013 UT : constant Entity_Id := Underlying_Type (T);
4019 -- Dismiss cases for generic types or types with previous errors
4022 or else UT = Any_Type
4023 or else Is_Generic_Type (UT)
4024 or else Is_Generic_Type (Root_Type (UT))
4028 -- Check case of bit packed array
4030 elsif Is_Array_Type (UT)
4031 and then Known_Static_Component_Size (UT)
4032 and then Is_Bit_Packed_Array (UT)
4040 Asiz := Component_Size (UT);
4041 Indx := First_Index (UT);
4043 Ityp := Etype (Indx);
4045 -- If non-static bound, then we are not in the business of
4046 -- trying to check the length, and indeed an error will be
4047 -- issued elsewhere, since sizes of non-static array types
4048 -- cannot be set implicitly or explicitly.
4050 if not Is_Static_Subtype (Ityp) then
4054 -- Otherwise accumulate next dimension
4056 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
4057 Expr_Value (Type_Low_Bound (Ityp)) +
4061 exit when No (Indx);
4067 Error_Msg_Uint_1 := Asiz;
4069 ("size for& too small, minimum allowed is ^", N, T);
4070 Set_Esize (T, Asiz);
4071 Set_RM_Size (T, Asiz);
4075 -- All other composite types are ignored
4077 elsif Is_Composite_Type (UT) then
4080 -- For fixed-point types, don't check minimum if type is not frozen,
4081 -- since we don't know all the characteristics of the type that can
4082 -- affect the size (e.g. a specified small) till freeze time.
4084 elsif Is_Fixed_Point_Type (UT)
4085 and then not Is_Frozen (UT)
4089 -- Cases for which a minimum check is required
4092 -- Ignore if specified size is correct for the type
4094 if Known_Esize (UT) and then Siz = Esize (UT) then
4098 -- Otherwise get minimum size
4100 M := UI_From_Int (Minimum_Size (UT));
4104 -- Size is less than minimum size, but one possibility remains
4105 -- that we can manage with the new size if we bias the type.
4107 M := UI_From_Int (Minimum_Size (UT, Biased => True));
4110 Error_Msg_Uint_1 := M;
4112 ("size for& too small, minimum allowed is ^", N, T);
4122 -------------------------
4123 -- Get_Alignment_Value --
4124 -------------------------
4126 function Get_Alignment_Value (Expr : Node_Id) return Uint is
4127 Align : constant Uint := Static_Integer (Expr);
4130 if Align = No_Uint then
4133 elsif Align <= 0 then
4134 Error_Msg_N ("alignment value must be positive", Expr);
4138 for J in Int range 0 .. 64 loop
4140 M : constant Uint := Uint_2 ** J;
4143 exit when M = Align;
4147 ("alignment value must be power of 2", Expr);
4155 end Get_Alignment_Value;
4161 procedure Initialize is
4163 Unchecked_Conversions.Init;
4166 -------------------------
4167 -- Is_Operational_Item --
4168 -------------------------
4170 function Is_Operational_Item (N : Node_Id) return Boolean is
4172 if Nkind (N) /= N_Attribute_Definition_Clause then
4176 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
4178 return Id = Attribute_Input
4179 or else Id = Attribute_Output
4180 or else Id = Attribute_Read
4181 or else Id = Attribute_Write
4182 or else Id = Attribute_External_Tag;
4185 end Is_Operational_Item;
4191 function Minimum_Size
4193 Biased : Boolean := False) return Nat
4195 Lo : Uint := No_Uint;
4196 Hi : Uint := No_Uint;
4197 LoR : Ureal := No_Ureal;
4198 HiR : Ureal := No_Ureal;
4199 LoSet : Boolean := False;
4200 HiSet : Boolean := False;
4204 R_Typ : constant Entity_Id := Root_Type (T);
4207 -- If bad type, return 0
4209 if T = Any_Type then
4212 -- For generic types, just return zero. There cannot be any legitimate
4213 -- need to know such a size, but this routine may be called with a
4214 -- generic type as part of normal processing.
4216 elsif Is_Generic_Type (R_Typ)
4217 or else R_Typ = Any_Type
4221 -- Access types. Normally an access type cannot have a size smaller
4222 -- than the size of System.Address. The exception is on VMS, where
4223 -- we have short and long addresses, and it is possible for an access
4224 -- type to have a short address size (and thus be less than the size
4225 -- of System.Address itself). We simply skip the check for VMS, and
4226 -- leave it to the back end to do the check.
4228 elsif Is_Access_Type (T) then
4229 if OpenVMS_On_Target then
4232 return System_Address_Size;
4235 -- Floating-point types
4237 elsif Is_Floating_Point_Type (T) then
4238 return UI_To_Int (Esize (R_Typ));
4242 elsif Is_Discrete_Type (T) then
4244 -- The following loop is looking for the nearest compile time known
4245 -- bounds following the ancestor subtype chain. The idea is to find
4246 -- the most restrictive known bounds information.
4250 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4255 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
4256 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
4263 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
4264 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
4270 Ancest := Ancestor_Subtype (Ancest);
4273 Ancest := Base_Type (T);
4275 if Is_Generic_Type (Ancest) then
4281 -- Fixed-point types. We can't simply use Expr_Value to get the
4282 -- Corresponding_Integer_Value values of the bounds, since these do not
4283 -- get set till the type is frozen, and this routine can be called
4284 -- before the type is frozen. Similarly the test for bounds being static
4285 -- needs to include the case where we have unanalyzed real literals for
4288 elsif Is_Fixed_Point_Type (T) then
4290 -- The following loop is looking for the nearest compile time known
4291 -- bounds following the ancestor subtype chain. The idea is to find
4292 -- the most restrictive known bounds information.
4296 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4300 -- Note: In the following two tests for LoSet and HiSet, it may
4301 -- seem redundant to test for N_Real_Literal here since normally
4302 -- one would assume that the test for the value being known at
4303 -- compile time includes this case. However, there is a glitch.
4304 -- If the real literal comes from folding a non-static expression,
4305 -- then we don't consider any non- static expression to be known
4306 -- at compile time if we are in configurable run time mode (needed
4307 -- in some cases to give a clearer definition of what is and what
4308 -- is not accepted). So the test is indeed needed. Without it, we
4309 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
4312 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
4313 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
4315 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
4322 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
4323 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
4325 HiR := Expr_Value_R (Type_High_Bound (Ancest));
4331 Ancest := Ancestor_Subtype (Ancest);
4334 Ancest := Base_Type (T);
4336 if Is_Generic_Type (Ancest) then
4342 Lo := UR_To_Uint (LoR / Small_Value (T));
4343 Hi := UR_To_Uint (HiR / Small_Value (T));
4345 -- No other types allowed
4348 raise Program_Error;
4351 -- Fall through with Hi and Lo set. Deal with biased case
4354 and then not Is_Fixed_Point_Type (T)
4355 and then not (Is_Enumeration_Type (T)
4356 and then Has_Non_Standard_Rep (T)))
4357 or else Has_Biased_Representation (T)
4363 -- Signed case. Note that we consider types like range 1 .. -1 to be
4364 -- signed for the purpose of computing the size, since the bounds have
4365 -- to be accommodated in the base type.
4367 if Lo < 0 or else Hi < 0 then
4371 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
4372 -- Note that we accommodate the case where the bounds cross. This
4373 -- can happen either because of the way the bounds are declared
4374 -- or because of the algorithm in Freeze_Fixed_Point_Type.
4388 -- If both bounds are positive, make sure that both are represen-
4389 -- table in the case where the bounds are crossed. This can happen
4390 -- either because of the way the bounds are declared, or because of
4391 -- the algorithm in Freeze_Fixed_Point_Type.
4397 -- S = size, (can accommodate 0 .. (2**size - 1))
4400 while Hi >= Uint_2 ** S loop
4408 ---------------------------
4409 -- New_Stream_Subprogram --
4410 ---------------------------
4412 procedure New_Stream_Subprogram
4416 Nam : TSS_Name_Type)
4418 Loc : constant Source_Ptr := Sloc (N);
4419 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
4420 Subp_Id : Entity_Id;
4421 Subp_Decl : Node_Id;
4425 Defer_Declaration : constant Boolean :=
4426 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
4427 -- For a tagged type, there is a declaration for each stream attribute
4428 -- at the freeze point, and we must generate only a completion of this
4429 -- declaration. We do the same for private types, because the full view
4430 -- might be tagged. Otherwise we generate a declaration at the point of
4431 -- the attribute definition clause.
4433 function Build_Spec return Node_Id;
4434 -- Used for declaration and renaming declaration, so that this is
4435 -- treated as a renaming_as_body.
4441 function Build_Spec return Node_Id is
4442 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
4445 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
4448 Subp_Id := Make_Defining_Identifier (Loc, Sname);
4450 -- S : access Root_Stream_Type'Class
4452 Formals := New_List (
4453 Make_Parameter_Specification (Loc,
4454 Defining_Identifier =>
4455 Make_Defining_Identifier (Loc, Name_S),
4457 Make_Access_Definition (Loc,
4460 Designated_Type (Etype (F)), Loc))));
4462 if Nam = TSS_Stream_Input then
4463 Spec := Make_Function_Specification (Loc,
4464 Defining_Unit_Name => Subp_Id,
4465 Parameter_Specifications => Formals,
4466 Result_Definition => T_Ref);
4471 Make_Parameter_Specification (Loc,
4472 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
4473 Out_Present => Out_P,
4474 Parameter_Type => T_Ref));
4477 Make_Procedure_Specification (Loc,
4478 Defining_Unit_Name => Subp_Id,
4479 Parameter_Specifications => Formals);
4485 -- Start of processing for New_Stream_Subprogram
4488 F := First_Formal (Subp);
4490 if Ekind (Subp) = E_Procedure then
4491 Etyp := Etype (Next_Formal (F));
4493 Etyp := Etype (Subp);
4496 -- Prepare subprogram declaration and insert it as an action on the
4497 -- clause node. The visibility for this entity is used to test for
4498 -- visibility of the attribute definition clause (in the sense of
4499 -- 8.3(23) as amended by AI-195).
4501 if not Defer_Declaration then
4503 Make_Subprogram_Declaration (Loc,
4504 Specification => Build_Spec);
4506 -- For a tagged type, there is always a visible declaration for each
4507 -- stream TSS (it is a predefined primitive operation), and the
4508 -- completion of this declaration occurs at the freeze point, which is
4509 -- not always visible at places where the attribute definition clause is
4510 -- visible. So, we create a dummy entity here for the purpose of
4511 -- tracking the visibility of the attribute definition clause itself.
4515 Make_Defining_Identifier (Loc,
4516 Chars => New_External_Name (Sname, 'V'));
4518 Make_Object_Declaration (Loc,
4519 Defining_Identifier => Subp_Id,
4520 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
4523 Insert_Action (N, Subp_Decl);
4524 Set_Entity (N, Subp_Id);
4527 Make_Subprogram_Renaming_Declaration (Loc,
4528 Specification => Build_Spec,
4529 Name => New_Reference_To (Subp, Loc));
4531 if Defer_Declaration then
4532 Set_TSS (Base_Type (Ent), Subp_Id);
4534 Insert_Action (N, Subp_Decl);
4535 Copy_TSS (Subp_Id, Base_Type (Ent));
4537 end New_Stream_Subprogram;
4539 ------------------------
4540 -- Rep_Item_Too_Early --
4541 ------------------------
4543 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
4545 -- Cannot apply non-operational rep items to generic types
4547 if Is_Operational_Item (N) then
4551 and then Is_Generic_Type (Root_Type (T))
4553 Error_Msg_N ("representation item not allowed for generic type", N);
4557 -- Otherwise check for incomplete type
4559 if Is_Incomplete_Or_Private_Type (T)
4560 and then No (Underlying_Type (T))
4563 ("representation item must be after full type declaration", N);
4566 -- If the type has incomplete components, a representation clause is
4567 -- illegal but stream attributes and Convention pragmas are correct.
4569 elsif Has_Private_Component (T) then
4570 if Nkind (N) = N_Pragma then
4574 ("representation item must appear after type is fully defined",
4581 end Rep_Item_Too_Early;
4583 -----------------------
4584 -- Rep_Item_Too_Late --
4585 -----------------------
4587 function Rep_Item_Too_Late
4590 FOnly : Boolean := False) return Boolean
4593 Parent_Type : Entity_Id;
4596 -- Output the too late message. Note that this is not considered a
4597 -- serious error, since the effect is simply that we ignore the
4598 -- representation clause in this case.
4604 procedure Too_Late is
4606 Error_Msg_N ("|representation item appears too late!", N);
4609 -- Start of processing for Rep_Item_Too_Late
4612 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
4613 -- types, which may be frozen if they appear in a representation clause
4614 -- for a local type.
4617 and then not From_With_Type (T)
4620 S := First_Subtype (T);
4622 if Present (Freeze_Node (S)) then
4624 ("?no more representation items for }", Freeze_Node (S), S);
4629 -- Check for case of non-tagged derived type whose parent either has
4630 -- primitive operations, or is a by reference type (RM 13.1(10)).
4634 and then Is_Derived_Type (T)
4635 and then not Is_Tagged_Type (T)
4637 Parent_Type := Etype (Base_Type (T));
4639 if Has_Primitive_Operations (Parent_Type) then
4642 ("primitive operations already defined for&!", N, Parent_Type);
4645 elsif Is_By_Reference_Type (Parent_Type) then
4648 ("parent type & is a by reference type!", N, Parent_Type);
4653 -- No error, link item into head of chain of rep items for the entity,
4654 -- but avoid chaining if we have an overloadable entity, and the pragma
4655 -- is one that can apply to multiple overloaded entities.
4657 if Is_Overloadable (T)
4658 and then Nkind (N) = N_Pragma
4661 Pname : constant Name_Id := Pragma_Name (N);
4663 if Pname = Name_Convention or else
4664 Pname = Name_Import or else
4665 Pname = Name_Export or else
4666 Pname = Name_External or else
4667 Pname = Name_Interface
4674 Record_Rep_Item (T, N);
4676 end Rep_Item_Too_Late;
4678 -------------------------
4679 -- Same_Representation --
4680 -------------------------
4682 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
4683 T1 : constant Entity_Id := Underlying_Type (Typ1);
4684 T2 : constant Entity_Id := Underlying_Type (Typ2);
4687 -- A quick check, if base types are the same, then we definitely have
4688 -- the same representation, because the subtype specific representation
4689 -- attributes (Size and Alignment) do not affect representation from
4690 -- the point of view of this test.
4692 if Base_Type (T1) = Base_Type (T2) then
4695 elsif Is_Private_Type (Base_Type (T2))
4696 and then Base_Type (T1) = Full_View (Base_Type (T2))
4701 -- Tagged types never have differing representations
4703 if Is_Tagged_Type (T1) then
4707 -- Representations are definitely different if conventions differ
4709 if Convention (T1) /= Convention (T2) then
4713 -- Representations are different if component alignments differ
4715 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4717 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4718 and then Component_Alignment (T1) /= Component_Alignment (T2)
4723 -- For arrays, the only real issue is component size. If we know the
4724 -- component size for both arrays, and it is the same, then that's
4725 -- good enough to know we don't have a change of representation.
4727 if Is_Array_Type (T1) then
4728 if Known_Component_Size (T1)
4729 and then Known_Component_Size (T2)
4730 and then Component_Size (T1) = Component_Size (T2)
4736 -- Types definitely have same representation if neither has non-standard
4737 -- representation since default representations are always consistent.
4738 -- If only one has non-standard representation, and the other does not,
4739 -- then we consider that they do not have the same representation. They
4740 -- might, but there is no way of telling early enough.
4742 if Has_Non_Standard_Rep (T1) then
4743 if not Has_Non_Standard_Rep (T2) then
4747 return not Has_Non_Standard_Rep (T2);
4750 -- Here the two types both have non-standard representation, and we need
4751 -- to determine if they have the same non-standard representation.
4753 -- For arrays, we simply need to test if the component sizes are the
4754 -- same. Pragma Pack is reflected in modified component sizes, so this
4755 -- check also deals with pragma Pack.
4757 if Is_Array_Type (T1) then
4758 return Component_Size (T1) = Component_Size (T2);
4760 -- Tagged types always have the same representation, because it is not
4761 -- possible to specify different representations for common fields.
4763 elsif Is_Tagged_Type (T1) then
4766 -- Case of record types
4768 elsif Is_Record_Type (T1) then
4770 -- Packed status must conform
4772 if Is_Packed (T1) /= Is_Packed (T2) then
4775 -- Otherwise we must check components. Typ2 maybe a constrained
4776 -- subtype with fewer components, so we compare the components
4777 -- of the base types.
4780 Record_Case : declare
4781 CD1, CD2 : Entity_Id;
4783 function Same_Rep return Boolean;
4784 -- CD1 and CD2 are either components or discriminants. This
4785 -- function tests whether the two have the same representation
4791 function Same_Rep return Boolean is
4793 if No (Component_Clause (CD1)) then
4794 return No (Component_Clause (CD2));
4798 Present (Component_Clause (CD2))
4800 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4802 Esize (CD1) = Esize (CD2);
4806 -- Start of processing for Record_Case
4809 if Has_Discriminants (T1) then
4810 CD1 := First_Discriminant (T1);
4811 CD2 := First_Discriminant (T2);
4813 -- The number of discriminants may be different if the
4814 -- derived type has fewer (constrained by values). The
4815 -- invisible discriminants retain the representation of
4816 -- the original, so the discrepancy does not per se
4817 -- indicate a different representation.
4820 and then Present (CD2)
4822 if not Same_Rep then
4825 Next_Discriminant (CD1);
4826 Next_Discriminant (CD2);
4831 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4832 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4834 while Present (CD1) loop
4835 if not Same_Rep then
4838 Next_Component (CD1);
4839 Next_Component (CD2);
4847 -- For enumeration types, we must check each literal to see if the
4848 -- representation is the same. Note that we do not permit enumeration
4849 -- representation clauses for Character and Wide_Character, so these
4850 -- cases were already dealt with.
4852 elsif Is_Enumeration_Type (T1) then
4853 Enumeration_Case : declare
4857 L1 := First_Literal (T1);
4858 L2 := First_Literal (T2);
4860 while Present (L1) loop
4861 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4871 end Enumeration_Case;
4873 -- Any other types have the same representation for these purposes
4878 end Same_Representation;
4884 procedure Set_Biased
4888 Biased : Boolean := True)
4892 Set_Has_Biased_Representation (E);
4894 if Warn_On_Biased_Representation then
4896 ("?" & Msg & " forces biased representation for&", N, E);
4901 --------------------
4902 -- Set_Enum_Esize --
4903 --------------------
4905 procedure Set_Enum_Esize (T : Entity_Id) is
4913 -- Find the minimum standard size (8,16,32,64) that fits
4915 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4916 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4919 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4920 Sz := Standard_Character_Size; -- May be > 8 on some targets
4922 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4925 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4928 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4933 if Hi < Uint_2**08 then
4934 Sz := Standard_Character_Size; -- May be > 8 on some targets
4936 elsif Hi < Uint_2**16 then
4939 elsif Hi < Uint_2**32 then
4942 else pragma Assert (Hi < Uint_2**63);
4947 -- That minimum is the proper size unless we have a foreign convention
4948 -- and the size required is 32 or less, in which case we bump the size
4949 -- up to 32. This is required for C and C++ and seems reasonable for
4950 -- all other foreign conventions.
4952 if Has_Foreign_Convention (T)
4953 and then Esize (T) < Standard_Integer_Size
4955 Init_Esize (T, Standard_Integer_Size);
4961 ------------------------------
4962 -- Validate_Address_Clauses --
4963 ------------------------------
4965 procedure Validate_Address_Clauses is
4967 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4969 ACCR : Address_Clause_Check_Record
4970 renames Address_Clause_Checks.Table (J);
4981 -- Skip processing of this entry if warning already posted
4983 if not Address_Warning_Posted (ACCR.N) then
4985 Expr := Original_Node (Expression (ACCR.N));
4989 X_Alignment := Alignment (ACCR.X);
4990 Y_Alignment := Alignment (ACCR.Y);
4992 -- Similarly obtain sizes
4994 X_Size := Esize (ACCR.X);
4995 Y_Size := Esize (ACCR.Y);
4997 -- Check for large object overlaying smaller one
5000 and then X_Size > Uint_0
5001 and then X_Size > Y_Size
5004 ("?& overlays smaller object", ACCR.N, ACCR.X);
5006 ("\?program execution may be erroneous", ACCR.N);
5007 Error_Msg_Uint_1 := X_Size;
5009 ("\?size of & is ^", ACCR.N, ACCR.X);
5010 Error_Msg_Uint_1 := Y_Size;
5012 ("\?size of & is ^", ACCR.N, ACCR.Y);
5014 -- Check for inadequate alignment, both of the base object
5015 -- and of the offset, if any.
5017 -- Note: we do not check the alignment if we gave a size
5018 -- warning, since it would likely be redundant.
5020 elsif Y_Alignment /= Uint_0
5021 and then (Y_Alignment < X_Alignment
5024 Nkind (Expr) = N_Attribute_Reference
5026 Attribute_Name (Expr) = Name_Address
5028 Has_Compatible_Alignment
5029 (ACCR.X, Prefix (Expr))
5030 /= Known_Compatible))
5033 ("?specified address for& may be inconsistent "
5037 ("\?program execution may be erroneous (RM 13.3(27))",
5039 Error_Msg_Uint_1 := X_Alignment;
5041 ("\?alignment of & is ^",
5043 Error_Msg_Uint_1 := Y_Alignment;
5045 ("\?alignment of & is ^",
5047 if Y_Alignment >= X_Alignment then
5049 ("\?but offset is not multiple of alignment",
5056 end Validate_Address_Clauses;
5058 -----------------------------------
5059 -- Validate_Unchecked_Conversion --
5060 -----------------------------------
5062 procedure Validate_Unchecked_Conversion
5064 Act_Unit : Entity_Id)
5071 -- Obtain source and target types. Note that we call Ancestor_Subtype
5072 -- here because the processing for generic instantiation always makes
5073 -- subtypes, and we want the original frozen actual types.
5075 -- If we are dealing with private types, then do the check on their
5076 -- fully declared counterparts if the full declarations have been
5077 -- encountered (they don't have to be visible, but they must exist!)
5079 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
5081 if Is_Private_Type (Source)
5082 and then Present (Underlying_Type (Source))
5084 Source := Underlying_Type (Source);
5087 Target := Ancestor_Subtype (Etype (Act_Unit));
5089 -- If either type is generic, the instantiation happens within a generic
5090 -- unit, and there is nothing to check. The proper check
5091 -- will happen when the enclosing generic is instantiated.
5093 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
5097 if Is_Private_Type (Target)
5098 and then Present (Underlying_Type (Target))
5100 Target := Underlying_Type (Target);
5103 -- Source may be unconstrained array, but not target
5105 if Is_Array_Type (Target)
5106 and then not Is_Constrained (Target)
5109 ("unchecked conversion to unconstrained array not allowed", N);
5113 -- Warn if conversion between two different convention pointers
5115 if Is_Access_Type (Target)
5116 and then Is_Access_Type (Source)
5117 and then Convention (Target) /= Convention (Source)
5118 and then Warn_On_Unchecked_Conversion
5120 -- Give warnings for subprogram pointers only on most targets. The
5121 -- exception is VMS, where data pointers can have different lengths
5122 -- depending on the pointer convention.
5124 if Is_Access_Subprogram_Type (Target)
5125 or else Is_Access_Subprogram_Type (Source)
5126 or else OpenVMS_On_Target
5129 ("?conversion between pointers with different conventions!", N);
5133 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
5134 -- warning when compiling GNAT-related sources.
5136 if Warn_On_Unchecked_Conversion
5137 and then not In_Predefined_Unit (N)
5138 and then RTU_Loaded (Ada_Calendar)
5140 (Chars (Source) = Name_Time
5142 Chars (Target) = Name_Time)
5144 -- If Ada.Calendar is loaded and the name of one of the operands is
5145 -- Time, there is a good chance that this is Ada.Calendar.Time.
5148 Calendar_Time : constant Entity_Id :=
5149 Full_View (RTE (RO_CA_Time));
5151 pragma Assert (Present (Calendar_Time));
5153 if Source = Calendar_Time
5154 or else Target = Calendar_Time
5157 ("?representation of 'Time values may change between " &
5158 "'G'N'A'T versions", N);
5163 -- Make entry in unchecked conversion table for later processing by
5164 -- Validate_Unchecked_Conversions, which will check sizes and alignments
5165 -- (using values set by the back-end where possible). This is only done
5166 -- if the appropriate warning is active.
5168 if Warn_On_Unchecked_Conversion then
5169 Unchecked_Conversions.Append
5170 (New_Val => UC_Entry'
5175 -- If both sizes are known statically now, then back end annotation
5176 -- is not required to do a proper check but if either size is not
5177 -- known statically, then we need the annotation.
5179 if Known_Static_RM_Size (Source)
5180 and then Known_Static_RM_Size (Target)
5184 Back_Annotate_Rep_Info := True;
5188 -- If unchecked conversion to access type, and access type is declared
5189 -- in the same unit as the unchecked conversion, then set the
5190 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
5193 if Is_Access_Type (Target) and then
5194 In_Same_Source_Unit (Target, N)
5196 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
5199 -- Generate N_Validate_Unchecked_Conversion node for back end in
5200 -- case the back end needs to perform special validation checks.
5202 -- Shouldn't this be in Exp_Ch13, since the check only gets done
5203 -- if we have full expansion and the back end is called ???
5206 Make_Validate_Unchecked_Conversion (Sloc (N));
5207 Set_Source_Type (Vnode, Source);
5208 Set_Target_Type (Vnode, Target);
5210 -- If the unchecked conversion node is in a list, just insert before it.
5211 -- If not we have some strange case, not worth bothering about.
5213 if Is_List_Member (N) then
5214 Insert_After (N, Vnode);
5216 end Validate_Unchecked_Conversion;
5218 ------------------------------------
5219 -- Validate_Unchecked_Conversions --
5220 ------------------------------------
5222 procedure Validate_Unchecked_Conversions is
5224 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
5226 T : UC_Entry renames Unchecked_Conversions.Table (N);
5228 Eloc : constant Source_Ptr := T.Eloc;
5229 Source : constant Entity_Id := T.Source;
5230 Target : constant Entity_Id := T.Target;
5236 -- This validation check, which warns if we have unequal sizes for
5237 -- unchecked conversion, and thus potentially implementation
5238 -- dependent semantics, is one of the few occasions on which we
5239 -- use the official RM size instead of Esize. See description in
5240 -- Einfo "Handling of Type'Size Values" for details.
5242 if Serious_Errors_Detected = 0
5243 and then Known_Static_RM_Size (Source)
5244 and then Known_Static_RM_Size (Target)
5246 -- Don't do the check if warnings off for either type, note the
5247 -- deliberate use of OR here instead of OR ELSE to get the flag
5248 -- Warnings_Off_Used set for both types if appropriate.
5250 and then not (Has_Warnings_Off (Source)
5252 Has_Warnings_Off (Target))
5254 Source_Siz := RM_Size (Source);
5255 Target_Siz := RM_Size (Target);
5257 if Source_Siz /= Target_Siz then
5259 ("?types for unchecked conversion have different sizes!",
5262 if All_Errors_Mode then
5263 Error_Msg_Name_1 := Chars (Source);
5264 Error_Msg_Uint_1 := Source_Siz;
5265 Error_Msg_Name_2 := Chars (Target);
5266 Error_Msg_Uint_2 := Target_Siz;
5267 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
5269 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
5271 if Is_Discrete_Type (Source)
5272 and then Is_Discrete_Type (Target)
5274 if Source_Siz > Target_Siz then
5276 ("\?^ high order bits of source will be ignored!",
5279 elsif Is_Unsigned_Type (Source) then
5281 ("\?source will be extended with ^ high order " &
5282 "zero bits?!", Eloc);
5286 ("\?source will be extended with ^ high order " &
5291 elsif Source_Siz < Target_Siz then
5292 if Is_Discrete_Type (Target) then
5293 if Bytes_Big_Endian then
5295 ("\?target value will include ^ undefined " &
5300 ("\?target value will include ^ undefined " &
5307 ("\?^ trailing bits of target value will be " &
5308 "undefined!", Eloc);
5311 else pragma Assert (Source_Siz > Target_Siz);
5313 ("\?^ trailing bits of source will be ignored!",
5320 -- If both types are access types, we need to check the alignment.
5321 -- If the alignment of both is specified, we can do it here.
5323 if Serious_Errors_Detected = 0
5324 and then Ekind (Source) in Access_Kind
5325 and then Ekind (Target) in Access_Kind
5326 and then Target_Strict_Alignment
5327 and then Present (Designated_Type (Source))
5328 and then Present (Designated_Type (Target))
5331 D_Source : constant Entity_Id := Designated_Type (Source);
5332 D_Target : constant Entity_Id := Designated_Type (Target);
5335 if Known_Alignment (D_Source)
5336 and then Known_Alignment (D_Target)
5339 Source_Align : constant Uint := Alignment (D_Source);
5340 Target_Align : constant Uint := Alignment (D_Target);
5343 if Source_Align < Target_Align
5344 and then not Is_Tagged_Type (D_Source)
5346 -- Suppress warning if warnings suppressed on either
5347 -- type or either designated type. Note the use of
5348 -- OR here instead of OR ELSE. That is intentional,
5349 -- we would like to set flag Warnings_Off_Used in
5350 -- all types for which warnings are suppressed.
5352 and then not (Has_Warnings_Off (D_Source)
5354 Has_Warnings_Off (D_Target)
5356 Has_Warnings_Off (Source)
5358 Has_Warnings_Off (Target))
5360 Error_Msg_Uint_1 := Target_Align;
5361 Error_Msg_Uint_2 := Source_Align;
5362 Error_Msg_Node_1 := D_Target;
5363 Error_Msg_Node_2 := D_Source;
5365 ("?alignment of & (^) is stricter than " &
5366 "alignment of & (^)!", Eloc);
5368 ("\?resulting access value may have invalid " &
5369 "alignment!", Eloc);
5377 end Validate_Unchecked_Conversions;
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