1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Errout; use Errout;
30 with Exp_Tss; use Exp_Tss;
31 with Exp_Util; use Exp_Util;
33 with Lib.Xref; use Lib.Xref;
34 with Namet; use Namet;
35 with Nlists; use Nlists;
36 with Nmake; use Nmake;
38 with Restrict; use Restrict;
39 with Rident; use Rident;
40 with Rtsfind; use Rtsfind;
42 with Sem_Aux; use Sem_Aux;
43 with Sem_Ch8; use Sem_Ch8;
44 with Sem_Eval; use Sem_Eval;
45 with Sem_Res; use Sem_Res;
46 with Sem_Type; use Sem_Type;
47 with Sem_Util; use Sem_Util;
48 with Sem_Warn; use Sem_Warn;
49 with Snames; use Snames;
50 with Stand; use Stand;
51 with Sinfo; use Sinfo;
53 with Targparm; use Targparm;
54 with Ttypes; use Ttypes;
55 with Tbuild; use Tbuild;
56 with Urealp; use Urealp;
58 with GNAT.Heap_Sort_G;
60 package body Sem_Ch13 is
62 SSU : constant Pos := System_Storage_Unit;
63 -- Convenient short hand for commonly used constant
65 -----------------------
66 -- Local Subprograms --
67 -----------------------
69 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
70 -- This routine is called after setting the Esize of type entity Typ.
71 -- The purpose is to deal with the situation where an alignment has been
72 -- inherited from a derived type that is no longer appropriate for the
73 -- new Esize value. In this case, we reset the Alignment to unknown.
75 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
76 -- Given two entities for record components or discriminants, checks
77 -- if they have overlapping component clauses and issues errors if so.
79 function Get_Alignment_Value (Expr : Node_Id) return Uint;
80 -- Given the expression for an alignment value, returns the corresponding
81 -- Uint value. If the value is inappropriate, then error messages are
82 -- posted as required, and a value of No_Uint is returned.
84 function Is_Operational_Item (N : Node_Id) return Boolean;
85 -- A specification for a stream attribute is allowed before the full
86 -- type is declared, as explained in AI-00137 and the corrigendum.
87 -- Attributes that do not specify a representation characteristic are
88 -- operational attributes.
90 procedure New_Stream_Subprogram
95 -- Create a subprogram renaming of a given stream attribute to the
96 -- designated subprogram and then in the tagged case, provide this as a
97 -- primitive operation, or in the non-tagged case make an appropriate TSS
98 -- entry. This is more properly an expansion activity than just semantics,
99 -- but the presence of user-defined stream functions for limited types is a
100 -- legality check, which is why this takes place here rather than in
101 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
102 -- function to be generated.
104 -- To avoid elaboration anomalies with freeze nodes, for untagged types
105 -- we generate both a subprogram declaration and a subprogram renaming
106 -- declaration, so that the attribute specification is handled as a
107 -- renaming_as_body. For tagged types, the specification is one of the
110 ----------------------------------------------
111 -- Table for Validate_Unchecked_Conversions --
112 ----------------------------------------------
114 -- The following table collects unchecked conversions for validation.
115 -- Entries are made by Validate_Unchecked_Conversion and then the
116 -- call to Validate_Unchecked_Conversions does the actual error
117 -- checking and posting of warnings. The reason for this delayed
118 -- processing is to take advantage of back-annotations of size and
119 -- alignment values performed by the back end.
121 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
122 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
123 -- will already have modified all Sloc values if the -gnatD option is set.
125 type UC_Entry is record
126 Eloc : Source_Ptr; -- node used for posting warnings
127 Source : Entity_Id; -- source type for unchecked conversion
128 Target : Entity_Id; -- target type for unchecked conversion
131 package Unchecked_Conversions is new Table.Table (
132 Table_Component_Type => UC_Entry,
133 Table_Index_Type => Int,
134 Table_Low_Bound => 1,
136 Table_Increment => 200,
137 Table_Name => "Unchecked_Conversions");
139 ----------------------------------------
140 -- Table for Validate_Address_Clauses --
141 ----------------------------------------
143 -- If an address clause has the form
145 -- for X'Address use Expr
147 -- where Expr is of the form Y'Address or recursively is a reference
148 -- to a constant of either of these forms, and X and Y are entities of
149 -- objects, then if Y has a smaller alignment than X, that merits a
150 -- warning about possible bad alignment. The following table collects
151 -- address clauses of this kind. We put these in a table so that they
152 -- can be checked after the back end has completed annotation of the
153 -- alignments of objects, since we can catch more cases that way.
155 type Address_Clause_Check_Record is record
157 -- The address clause
160 -- The entity of the object overlaying Y
163 -- The entity of the object being overlaid
166 -- Whether the address is offseted within Y
169 package Address_Clause_Checks is new Table.Table (
170 Table_Component_Type => Address_Clause_Check_Record,
171 Table_Index_Type => Int,
172 Table_Low_Bound => 1,
174 Table_Increment => 200,
175 Table_Name => "Address_Clause_Checks");
177 -----------------------------------------
178 -- Adjust_Record_For_Reverse_Bit_Order --
179 -----------------------------------------
181 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
182 Max_Machine_Scalar_Size : constant Uint :=
184 (Standard_Long_Long_Integer_Size);
185 -- We use this as the maximum machine scalar size in the sense of AI-133
189 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
192 -- This first loop through components does two things. First it deals
193 -- with the case of components with component clauses whose length is
194 -- greater than the maximum machine scalar size (either accepting them
195 -- or rejecting as needed). Second, it counts the number of components
196 -- with component clauses whose length does not exceed this maximum for
200 Comp := First_Component_Or_Discriminant (R);
201 while Present (Comp) loop
203 CC : constant Node_Id := Component_Clause (Comp);
208 Fbit : constant Uint := Static_Integer (First_Bit (CC));
211 -- Case of component with size > max machine scalar
213 if Esize (Comp) > Max_Machine_Scalar_Size then
215 -- Must begin on byte boundary
217 if Fbit mod SSU /= 0 then
219 ("illegal first bit value for reverse bit order",
221 Error_Msg_Uint_1 := SSU;
222 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
225 ("\must be a multiple of ^ if size greater than ^",
228 -- Must end on byte boundary
230 elsif Esize (Comp) mod SSU /= 0 then
232 ("illegal last bit value for reverse bit order",
234 Error_Msg_Uint_1 := SSU;
235 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
238 ("\must be a multiple of ^ if size greater than ^",
241 -- OK, give warning if enabled
243 elsif Warn_On_Reverse_Bit_Order then
245 ("multi-byte field specified with non-standard"
246 & " Bit_Order?", CC);
248 if Bytes_Big_Endian then
250 ("\bytes are not reversed "
251 & "(component is big-endian)?", CC);
254 ("\bytes are not reversed "
255 & "(component is little-endian)?", CC);
259 -- Case where size is not greater than max machine
260 -- scalar. For now, we just count these.
263 Num_CC := Num_CC + 1;
269 Next_Component_Or_Discriminant (Comp);
272 -- We need to sort the component clauses on the basis of the Position
273 -- values in the clause, so we can group clauses with the same Position.
274 -- together to determine the relevant machine scalar size.
277 Comps : array (0 .. Num_CC) of Entity_Id;
278 -- Array to collect component and discriminant entities. The data
279 -- starts at index 1, the 0'th entry is for the sort routine.
281 function CP_Lt (Op1, Op2 : Natural) return Boolean;
282 -- Compare routine for Sort
284 procedure CP_Move (From : Natural; To : Natural);
285 -- Move routine for Sort
287 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
291 -- Start and stop positions in component list of set of components
292 -- with the same starting position (that constitute components in
293 -- a single machine scalar).
296 -- Maximum last bit value of any component in this set
299 -- Corresponding machine scalar size
305 function CP_Lt (Op1, Op2 : Natural) return Boolean is
307 return Position (Component_Clause (Comps (Op1))) <
308 Position (Component_Clause (Comps (Op2)));
315 procedure CP_Move (From : Natural; To : Natural) is
317 Comps (To) := Comps (From);
321 -- Collect the component clauses
324 Comp := First_Component_Or_Discriminant (R);
325 while Present (Comp) loop
326 if Present (Component_Clause (Comp))
327 and then Esize (Comp) <= Max_Machine_Scalar_Size
329 Num_CC := Num_CC + 1;
330 Comps (Num_CC) := Comp;
333 Next_Component_Or_Discriminant (Comp);
336 -- Sort by ascending position number
338 Sorting.Sort (Num_CC);
340 -- We now have all the components whose size does not exceed the max
341 -- machine scalar value, sorted by starting position. In this loop
342 -- we gather groups of clauses starting at the same position, to
343 -- process them in accordance with Ada 2005 AI-133.
346 while Stop < Num_CC loop
350 Static_Integer (Last_Bit (Component_Clause (Comps (Start))));
351 while Stop < Num_CC loop
353 (Position (Component_Clause (Comps (Stop + 1)))) =
355 (Position (Component_Clause (Comps (Stop))))
362 (Last_Bit (Component_Clause (Comps (Stop)))));
368 -- Now we have a group of component clauses from Start to Stop
369 -- whose positions are identical, and MaxL is the maximum last bit
370 -- value of any of these components.
372 -- We need to determine the corresponding machine scalar size.
373 -- This loop assumes that machine scalar sizes are even, and that
374 -- each possible machine scalar has twice as many bits as the
377 MSS := Max_Machine_Scalar_Size;
379 and then (MSS / 2) >= SSU
380 and then (MSS / 2) > MaxL
385 -- Here is where we fix up the Component_Bit_Offset value to
386 -- account for the reverse bit order. Some examples of what needs
387 -- to be done for the case of a machine scalar size of 8 are:
389 -- First_Bit .. Last_Bit Component_Bit_Offset
401 -- The general rule is that the first bit is obtained by
402 -- subtracting the old ending bit from machine scalar size - 1.
404 for C in Start .. Stop loop
406 Comp : constant Entity_Id := Comps (C);
407 CC : constant Node_Id := Component_Clause (Comp);
408 LB : constant Uint := Static_Integer (Last_Bit (CC));
409 NFB : constant Uint := MSS - Uint_1 - LB;
410 NLB : constant Uint := NFB + Esize (Comp) - 1;
411 Pos : constant Uint := Static_Integer (Position (CC));
414 if Warn_On_Reverse_Bit_Order then
415 Error_Msg_Uint_1 := MSS;
417 ("info: reverse bit order in machine " &
418 "scalar of length^?", First_Bit (CC));
419 Error_Msg_Uint_1 := NFB;
420 Error_Msg_Uint_2 := NLB;
422 if Bytes_Big_Endian then
424 ("?\info: big-endian range for "
425 & "component & is ^ .. ^",
426 First_Bit (CC), Comp);
429 ("?\info: little-endian range "
430 & "for component & is ^ .. ^",
431 First_Bit (CC), Comp);
435 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
436 Set_Normalized_First_Bit (Comp, NFB mod SSU);
441 end Adjust_Record_For_Reverse_Bit_Order;
443 --------------------------------------
444 -- Alignment_Check_For_Esize_Change --
445 --------------------------------------
447 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
449 -- If the alignment is known, and not set by a rep clause, and is
450 -- inconsistent with the size being set, then reset it to unknown,
451 -- we assume in this case that the size overrides the inherited
452 -- alignment, and that the alignment must be recomputed.
454 if Known_Alignment (Typ)
455 and then not Has_Alignment_Clause (Typ)
456 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
458 Init_Alignment (Typ);
460 end Alignment_Check_For_Esize_Change;
462 -----------------------
463 -- Analyze_At_Clause --
464 -----------------------
466 -- An at clause is replaced by the corresponding Address attribute
467 -- definition clause that is the preferred approach in Ada 95.
469 procedure Analyze_At_Clause (N : Node_Id) is
470 CS : constant Boolean := Comes_From_Source (N);
473 -- This is an obsolescent feature
475 Check_Restriction (No_Obsolescent_Features, N);
477 if Warn_On_Obsolescent_Feature then
479 ("at clause is an obsolescent feature (RM J.7(2))?", N);
481 ("\use address attribute definition clause instead?", N);
484 -- Rewrite as address clause
487 Make_Attribute_Definition_Clause (Sloc (N),
488 Name => Identifier (N),
489 Chars => Name_Address,
490 Expression => Expression (N)));
492 -- We preserve Comes_From_Source, since logically the clause still
493 -- comes from the source program even though it is changed in form.
495 Set_Comes_From_Source (N, CS);
497 -- Analyze rewritten clause
499 Analyze_Attribute_Definition_Clause (N);
500 end Analyze_At_Clause;
502 -----------------------------------------
503 -- Analyze_Attribute_Definition_Clause --
504 -----------------------------------------
506 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
507 Loc : constant Source_Ptr := Sloc (N);
508 Nam : constant Node_Id := Name (N);
509 Attr : constant Name_Id := Chars (N);
510 Expr : constant Node_Id := Expression (N);
511 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
515 FOnly : Boolean := False;
516 -- Reset to True for subtype specific attribute (Alignment, Size)
517 -- and for stream attributes, i.e. those cases where in the call
518 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
519 -- rules are checked. Note that the case of stream attributes is not
520 -- clear from the RM, but see AI95-00137. Also, the RM seems to
521 -- disallow Storage_Size for derived task types, but that is also
522 -- clearly unintentional.
524 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
525 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
526 -- definition clauses.
528 -----------------------------------
529 -- Analyze_Stream_TSS_Definition --
530 -----------------------------------
532 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
533 Subp : Entity_Id := Empty;
538 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
540 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
541 -- Return true if the entity is a subprogram with an appropriate
542 -- profile for the attribute being defined.
544 ----------------------
545 -- Has_Good_Profile --
546 ----------------------
548 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
550 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
551 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
552 (False => E_Procedure, True => E_Function);
556 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
560 F := First_Formal (Subp);
563 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
564 or else Designated_Type (Etype (F)) /=
565 Class_Wide_Type (RTE (RE_Root_Stream_Type))
570 if not Is_Function then
574 Expected_Mode : constant array (Boolean) of Entity_Kind :=
575 (False => E_In_Parameter,
576 True => E_Out_Parameter);
578 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
589 return Base_Type (Typ) = Base_Type (Ent)
590 and then No (Next_Formal (F));
591 end Has_Good_Profile;
593 -- Start of processing for Analyze_Stream_TSS_Definition
598 if not Is_Type (U_Ent) then
599 Error_Msg_N ("local name must be a subtype", Nam);
603 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
605 -- If Pnam is present, it can be either inherited from an ancestor
606 -- type (in which case it is legal to redefine it for this type), or
607 -- be a previous definition of the attribute for the same type (in
608 -- which case it is illegal).
610 -- In the first case, it will have been analyzed already, and we
611 -- can check that its profile does not match the expected profile
612 -- for a stream attribute of U_Ent. In the second case, either Pnam
613 -- has been analyzed (and has the expected profile), or it has not
614 -- been analyzed yet (case of a type that has not been frozen yet
615 -- and for which the stream attribute has been set using Set_TSS).
618 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
620 Error_Msg_Sloc := Sloc (Pnam);
621 Error_Msg_Name_1 := Attr;
622 Error_Msg_N ("% attribute already defined #", Nam);
628 if Is_Entity_Name (Expr) then
629 if not Is_Overloaded (Expr) then
630 if Has_Good_Profile (Entity (Expr)) then
631 Subp := Entity (Expr);
635 Get_First_Interp (Expr, I, It);
636 while Present (It.Nam) loop
637 if Has_Good_Profile (It.Nam) then
642 Get_Next_Interp (I, It);
647 if Present (Subp) then
648 if Is_Abstract_Subprogram (Subp) then
649 Error_Msg_N ("stream subprogram must not be abstract", Expr);
653 Set_Entity (Expr, Subp);
654 Set_Etype (Expr, Etype (Subp));
656 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
659 Error_Msg_Name_1 := Attr;
660 Error_Msg_N ("incorrect expression for% attribute", Expr);
662 end Analyze_Stream_TSS_Definition;
664 -- Start of processing for Analyze_Attribute_Definition_Clause
667 -- Process Ignore_Rep_Clauses option
669 if Ignore_Rep_Clauses then
672 -- The following should be ignored. They do not affect legality
673 -- and may be target dependent. The basic idea of -gnatI is to
674 -- ignore any rep clauses that may be target dependent but do not
675 -- affect legality (except possibly to be rejected because they
676 -- are incompatible with the compilation target).
678 when Attribute_Alignment |
679 Attribute_Bit_Order |
680 Attribute_Component_Size |
681 Attribute_Machine_Radix |
682 Attribute_Object_Size |
685 Attribute_Stream_Size |
686 Attribute_Value_Size =>
688 Rewrite (N, Make_Null_Statement (Sloc (N)));
691 -- The following should not be ignored, because in the first place
692 -- they are reasonably portable, and should not cause problems in
693 -- compiling code from another target, and also they do affect
694 -- legality, e.g. failing to provide a stream attribute for a
695 -- type may make a program illegal.
697 when Attribute_External_Tag |
701 Attribute_Storage_Pool |
702 Attribute_Storage_Size |
706 -- Other cases are errors, which will be caught below
716 if Rep_Item_Too_Early (Ent, N) then
720 -- Rep clause applies to full view of incomplete type or private type if
721 -- we have one (if not, this is a premature use of the type). However,
722 -- certain semantic checks need to be done on the specified entity (i.e.
723 -- the private view), so we save it in Ent.
725 if Is_Private_Type (Ent)
726 and then Is_Derived_Type (Ent)
727 and then not Is_Tagged_Type (Ent)
728 and then No (Full_View (Ent))
730 -- If this is a private type whose completion is a derivation from
731 -- another private type, there is no full view, and the attribute
732 -- belongs to the type itself, not its underlying parent.
736 elsif Ekind (Ent) = E_Incomplete_Type then
738 -- The attribute applies to the full view, set the entity of the
739 -- attribute definition accordingly.
741 Ent := Underlying_Type (Ent);
743 Set_Entity (Nam, Ent);
746 U_Ent := Underlying_Type (Ent);
749 -- Complete other routine error checks
751 if Etype (Nam) = Any_Type then
754 elsif Scope (Ent) /= Current_Scope then
755 Error_Msg_N ("entity must be declared in this scope", Nam);
758 elsif No (U_Ent) then
761 elsif Is_Type (U_Ent)
762 and then not Is_First_Subtype (U_Ent)
763 and then Id /= Attribute_Object_Size
764 and then Id /= Attribute_Value_Size
765 and then not From_At_Mod (N)
767 Error_Msg_N ("cannot specify attribute for subtype", Nam);
771 -- Switch on particular attribute
779 -- Address attribute definition clause
781 when Attribute_Address => Address : begin
783 -- A little error check, catch for X'Address use X'Address;
785 if Nkind (Nam) = N_Identifier
786 and then Nkind (Expr) = N_Attribute_Reference
787 and then Attribute_Name (Expr) = Name_Address
788 and then Nkind (Prefix (Expr)) = N_Identifier
789 and then Chars (Nam) = Chars (Prefix (Expr))
792 ("address for & is self-referencing", Prefix (Expr), Ent);
796 -- Not that special case, carry on with analysis of expression
798 Analyze_And_Resolve (Expr, RTE (RE_Address));
800 -- Even when ignoring rep clauses we need to indicate that the
801 -- entity has an address clause and thus it is legal to declare
804 if Ignore_Rep_Clauses then
805 if Ekind (U_Ent) = E_Variable
806 or else Ekind (U_Ent) = E_Constant
808 Record_Rep_Item (U_Ent, N);
814 if Present (Address_Clause (U_Ent)) then
815 Error_Msg_N ("address already given for &", Nam);
817 -- Case of address clause for subprogram
819 elsif Is_Subprogram (U_Ent) then
820 if Has_Homonym (U_Ent) then
822 ("address clause cannot be given " &
823 "for overloaded subprogram",
828 -- For subprograms, all address clauses are permitted, and we
829 -- mark the subprogram as having a deferred freeze so that Gigi
830 -- will not elaborate it too soon.
832 -- Above needs more comments, what is too soon about???
834 Set_Has_Delayed_Freeze (U_Ent);
836 -- Case of address clause for entry
838 elsif Ekind (U_Ent) = E_Entry then
839 if Nkind (Parent (N)) = N_Task_Body then
841 ("entry address must be specified in task spec", Nam);
845 -- For entries, we require a constant address
847 Check_Constant_Address_Clause (Expr, U_Ent);
849 -- Special checks for task types
851 if Is_Task_Type (Scope (U_Ent))
852 and then Comes_From_Source (Scope (U_Ent))
855 ("?entry address declared for entry in task type", N);
857 ("\?only one task can be declared of this type", N);
860 -- Entry address clauses are obsolescent
862 Check_Restriction (No_Obsolescent_Features, N);
864 if Warn_On_Obsolescent_Feature then
866 ("attaching interrupt to task entry is an " &
867 "obsolescent feature (RM J.7.1)?", N);
869 ("\use interrupt procedure instead?", N);
872 -- Case of an address clause for a controlled object which we
873 -- consider to be erroneous.
875 elsif Is_Controlled (Etype (U_Ent))
876 or else Has_Controlled_Component (Etype (U_Ent))
879 ("?controlled object& must not be overlaid", Nam, U_Ent);
881 ("\?Program_Error will be raised at run time", Nam);
882 Insert_Action (Declaration_Node (U_Ent),
883 Make_Raise_Program_Error (Loc,
884 Reason => PE_Overlaid_Controlled_Object));
887 -- Case of address clause for a (non-controlled) object
890 Ekind (U_Ent) = E_Variable
892 Ekind (U_Ent) = E_Constant
895 Expr : constant Node_Id := Expression (N);
900 -- Exported variables cannot have an address clause, because
901 -- this cancels the effect of the pragma Export.
903 if Is_Exported (U_Ent) then
905 ("cannot export object with address clause", Nam);
909 Find_Overlaid_Entity (N, O_Ent, Off);
911 -- Overlaying controlled objects is erroneous
914 and then (Has_Controlled_Component (Etype (O_Ent))
915 or else Is_Controlled (Etype (O_Ent)))
918 ("?cannot overlay with controlled object", Expr);
920 ("\?Program_Error will be raised at run time", Expr);
921 Insert_Action (Declaration_Node (U_Ent),
922 Make_Raise_Program_Error (Loc,
923 Reason => PE_Overlaid_Controlled_Object));
926 elsif Present (O_Ent)
927 and then Ekind (U_Ent) = E_Constant
928 and then not Is_Constant_Object (O_Ent)
930 Error_Msg_N ("constant overlays a variable?", Expr);
932 elsif Present (Renamed_Object (U_Ent)) then
934 ("address clause not allowed"
935 & " for a renaming declaration (RM 13.1(6))", Nam);
938 -- Imported variables can have an address clause, but then
939 -- the import is pretty meaningless except to suppress
940 -- initializations, so we do not need such variables to
941 -- be statically allocated (and in fact it causes trouble
942 -- if the address clause is a local value).
944 elsif Is_Imported (U_Ent) then
945 Set_Is_Statically_Allocated (U_Ent, False);
948 -- We mark a possible modification of a variable with an
949 -- address clause, since it is likely aliasing is occurring.
951 Note_Possible_Modification (Nam, Sure => False);
953 -- Here we are checking for explicit overlap of one variable
954 -- by another, and if we find this then mark the overlapped
955 -- variable as also being volatile to prevent unwanted
956 -- optimizations. This is a significant pessimization so
957 -- avoid it when there is an offset, i.e. when the object
958 -- is composite; they cannot be optimized easily anyway.
961 and then Is_Object (O_Ent)
964 Set_Treat_As_Volatile (O_Ent);
967 -- Legality checks on the address clause for initialized
968 -- objects is deferred until the freeze point, because
969 -- a subsequent pragma might indicate that the object is
970 -- imported and thus not initialized.
972 Set_Has_Delayed_Freeze (U_Ent);
974 -- If an initialization call has been generated for this
975 -- object, it needs to be deferred to after the freeze node
976 -- we have just now added, otherwise GIGI will see a
977 -- reference to the variable (as actual to the IP call)
978 -- before its definition.
981 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
983 if Present (Init_Call) then
985 Append_Freeze_Action (U_Ent, Init_Call);
989 if Is_Exported (U_Ent) then
991 ("& cannot be exported if an address clause is given",
994 ("\define and export a variable " &
995 "that holds its address instead",
999 -- Entity has delayed freeze, so we will generate an
1000 -- alignment check at the freeze point unless suppressed.
1002 if not Range_Checks_Suppressed (U_Ent)
1003 and then not Alignment_Checks_Suppressed (U_Ent)
1005 Set_Check_Address_Alignment (N);
1008 -- Kill the size check code, since we are not allocating
1009 -- the variable, it is somewhere else.
1011 Kill_Size_Check_Code (U_Ent);
1013 -- If the address clause is of the form:
1015 -- for Y'Address use X'Address
1019 -- Const : constant Address := X'Address;
1021 -- for Y'Address use Const;
1023 -- then we make an entry in the table for checking the size
1024 -- and alignment of the overlaying variable. We defer this
1025 -- check till after code generation to take full advantage
1026 -- of the annotation done by the back end. This entry is
1027 -- only made if the address clause comes from source.
1029 if Address_Clause_Overlay_Warnings
1030 and then Comes_From_Source (N)
1031 and then Present (O_Ent)
1032 and then Is_Object (O_Ent)
1034 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1036 -- If variable overlays a constant view, and we are
1037 -- warning on overlays, then mark the variable as
1038 -- overlaying a constant (we will give warnings later
1039 -- if this variable is assigned).
1041 if Is_Constant_Object (O_Ent)
1042 and then Ekind (U_Ent) = E_Variable
1044 Set_Overlays_Constant (U_Ent);
1049 -- Not a valid entity for an address clause
1052 Error_Msg_N ("address cannot be given for &", Nam);
1060 -- Alignment attribute definition clause
1062 when Attribute_Alignment => Alignment : declare
1063 Align : constant Uint := Get_Alignment_Value (Expr);
1068 if not Is_Type (U_Ent)
1069 and then Ekind (U_Ent) /= E_Variable
1070 and then Ekind (U_Ent) /= E_Constant
1072 Error_Msg_N ("alignment cannot be given for &", Nam);
1074 elsif Has_Alignment_Clause (U_Ent) then
1075 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1076 Error_Msg_N ("alignment clause previously given#", N);
1078 elsif Align /= No_Uint then
1079 Set_Has_Alignment_Clause (U_Ent);
1080 Set_Alignment (U_Ent, Align);
1082 -- For an array type, U_Ent is the first subtype. In that case,
1083 -- also set the alignment of the anonymous base type so that
1084 -- other subtypes (such as the itypes for aggregates of the
1085 -- type) also receive the expected alignment.
1087 if Is_Array_Type (U_Ent) then
1088 Set_Alignment (Base_Type (U_Ent), Align);
1097 -- Bit_Order attribute definition clause
1099 when Attribute_Bit_Order => Bit_Order : declare
1101 if not Is_Record_Type (U_Ent) then
1103 ("Bit_Order can only be defined for record type", Nam);
1106 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1108 if Etype (Expr) = Any_Type then
1111 elsif not Is_Static_Expression (Expr) then
1112 Flag_Non_Static_Expr
1113 ("Bit_Order requires static expression!", Expr);
1116 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1117 Set_Reverse_Bit_Order (U_Ent, True);
1123 --------------------
1124 -- Component_Size --
1125 --------------------
1127 -- Component_Size attribute definition clause
1129 when Attribute_Component_Size => Component_Size_Case : declare
1130 Csize : constant Uint := Static_Integer (Expr);
1133 New_Ctyp : Entity_Id;
1137 if not Is_Array_Type (U_Ent) then
1138 Error_Msg_N ("component size requires array type", Nam);
1142 Btype := Base_Type (U_Ent);
1144 if Has_Component_Size_Clause (Btype) then
1146 ("component size clause for& previously given", Nam);
1148 elsif Csize /= No_Uint then
1149 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
1151 if Has_Aliased_Components (Btype)
1154 and then Csize /= 16
1157 ("component size incorrect for aliased components", N);
1161 -- For the biased case, build a declaration for a subtype
1162 -- that will be used to represent the biased subtype that
1163 -- reflects the biased representation of components. We need
1164 -- this subtype to get proper conversions on referencing
1165 -- elements of the array. Note that component size clauses
1166 -- are ignored in VM mode.
1168 if VM_Target = No_VM then
1171 Make_Defining_Identifier (Loc,
1173 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1176 Make_Subtype_Declaration (Loc,
1177 Defining_Identifier => New_Ctyp,
1178 Subtype_Indication =>
1179 New_Occurrence_Of (Component_Type (Btype), Loc));
1181 Set_Parent (Decl, N);
1182 Analyze (Decl, Suppress => All_Checks);
1184 Set_Has_Delayed_Freeze (New_Ctyp, False);
1185 Set_Esize (New_Ctyp, Csize);
1186 Set_RM_Size (New_Ctyp, Csize);
1187 Init_Alignment (New_Ctyp);
1188 Set_Has_Biased_Representation (New_Ctyp, True);
1189 Set_Is_Itype (New_Ctyp, True);
1190 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1192 Set_Component_Type (Btype, New_Ctyp);
1194 if Warn_On_Biased_Representation then
1196 ("?component size clause forces biased "
1197 & "representation", N);
1201 Set_Component_Size (Btype, Csize);
1203 -- For VM case, we ignore component size clauses
1206 -- Give a warning unless we are in GNAT mode, in which case
1207 -- the warning is suppressed since it is not useful.
1209 if not GNAT_Mode then
1211 ("?component size ignored in this configuration", N);
1215 Set_Has_Component_Size_Clause (Btype, True);
1216 Set_Has_Non_Standard_Rep (Btype, True);
1218 end Component_Size_Case;
1224 when Attribute_External_Tag => External_Tag :
1226 if not Is_Tagged_Type (U_Ent) then
1227 Error_Msg_N ("should be a tagged type", Nam);
1230 Analyze_And_Resolve (Expr, Standard_String);
1232 if not Is_Static_Expression (Expr) then
1233 Flag_Non_Static_Expr
1234 ("static string required for tag name!", Nam);
1237 if VM_Target = No_VM then
1238 Set_Has_External_Tag_Rep_Clause (U_Ent);
1240 Error_Msg_Name_1 := Attr;
1242 ("% attribute unsupported in this configuration", Nam);
1245 if not Is_Library_Level_Entity (U_Ent) then
1247 ("?non-unique external tag supplied for &", N, U_Ent);
1249 ("?\same external tag applies to all subprogram calls", N);
1251 ("?\corresponding internal tag cannot be obtained", N);
1259 when Attribute_Input =>
1260 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1261 Set_Has_Specified_Stream_Input (Ent);
1267 -- Machine radix attribute definition clause
1269 when Attribute_Machine_Radix => Machine_Radix : declare
1270 Radix : constant Uint := Static_Integer (Expr);
1273 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1274 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1276 elsif Has_Machine_Radix_Clause (U_Ent) then
1277 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1278 Error_Msg_N ("machine radix clause previously given#", N);
1280 elsif Radix /= No_Uint then
1281 Set_Has_Machine_Radix_Clause (U_Ent);
1282 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1286 elsif Radix = 10 then
1287 Set_Machine_Radix_10 (U_Ent);
1289 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1298 -- Object_Size attribute definition clause
1300 when Attribute_Object_Size => Object_Size : declare
1301 Size : constant Uint := Static_Integer (Expr);
1304 pragma Warnings (Off, Biased);
1307 if not Is_Type (U_Ent) then
1308 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1310 elsif Has_Object_Size_Clause (U_Ent) then
1311 Error_Msg_N ("Object_Size already given for &", Nam);
1314 Check_Size (Expr, U_Ent, Size, Biased);
1322 UI_Mod (Size, 64) /= 0
1325 ("Object_Size must be 8, 16, 32, or multiple of 64",
1329 Set_Esize (U_Ent, Size);
1330 Set_Has_Object_Size_Clause (U_Ent);
1331 Alignment_Check_For_Esize_Change (U_Ent);
1339 when Attribute_Output =>
1340 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1341 Set_Has_Specified_Stream_Output (Ent);
1347 when Attribute_Read =>
1348 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1349 Set_Has_Specified_Stream_Read (Ent);
1355 -- Size attribute definition clause
1357 when Attribute_Size => Size : declare
1358 Size : constant Uint := Static_Integer (Expr);
1365 if Has_Size_Clause (U_Ent) then
1366 Error_Msg_N ("size already given for &", Nam);
1368 elsif not Is_Type (U_Ent)
1369 and then Ekind (U_Ent) /= E_Variable
1370 and then Ekind (U_Ent) /= E_Constant
1372 Error_Msg_N ("size cannot be given for &", Nam);
1374 elsif Is_Array_Type (U_Ent)
1375 and then not Is_Constrained (U_Ent)
1378 ("size cannot be given for unconstrained array", Nam);
1380 elsif Size /= No_Uint then
1381 if Is_Type (U_Ent) then
1384 Etyp := Etype (U_Ent);
1387 -- Check size, note that Gigi is in charge of checking that the
1388 -- size of an array or record type is OK. Also we do not check
1389 -- the size in the ordinary fixed-point case, since it is too
1390 -- early to do so (there may be subsequent small clause that
1391 -- affects the size). We can check the size if a small clause
1392 -- has already been given.
1394 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1395 or else Has_Small_Clause (U_Ent)
1397 Check_Size (Expr, Etyp, Size, Biased);
1398 Set_Has_Biased_Representation (U_Ent, Biased);
1400 if Biased and Warn_On_Biased_Representation then
1402 ("?size clause forces biased representation", N);
1406 -- For types set RM_Size and Esize if possible
1408 if Is_Type (U_Ent) then
1409 Set_RM_Size (U_Ent, Size);
1411 -- For scalar types, increase Object_Size to power of 2, but
1412 -- not less than a storage unit in any case (i.e., normally
1413 -- this means it will be byte addressable).
1415 if Is_Scalar_Type (U_Ent) then
1416 if Size <= System_Storage_Unit then
1417 Init_Esize (U_Ent, System_Storage_Unit);
1418 elsif Size <= 16 then
1419 Init_Esize (U_Ent, 16);
1420 elsif Size <= 32 then
1421 Init_Esize (U_Ent, 32);
1423 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1426 -- For all other types, object size = value size. The
1427 -- backend will adjust as needed.
1430 Set_Esize (U_Ent, Size);
1433 Alignment_Check_For_Esize_Change (U_Ent);
1435 -- For objects, set Esize only
1438 if Is_Elementary_Type (Etyp) then
1439 if Size /= System_Storage_Unit
1441 Size /= System_Storage_Unit * 2
1443 Size /= System_Storage_Unit * 4
1445 Size /= System_Storage_Unit * 8
1447 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1448 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1450 ("size for primitive object must be a power of 2"
1451 & " in the range ^-^", N);
1455 Set_Esize (U_Ent, Size);
1458 Set_Has_Size_Clause (U_Ent);
1466 -- Small attribute definition clause
1468 when Attribute_Small => Small : declare
1469 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1473 Analyze_And_Resolve (Expr, Any_Real);
1475 if Etype (Expr) = Any_Type then
1478 elsif not Is_Static_Expression (Expr) then
1479 Flag_Non_Static_Expr
1480 ("small requires static expression!", Expr);
1484 Small := Expr_Value_R (Expr);
1486 if Small <= Ureal_0 then
1487 Error_Msg_N ("small value must be greater than zero", Expr);
1493 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1495 ("small requires an ordinary fixed point type", Nam);
1497 elsif Has_Small_Clause (U_Ent) then
1498 Error_Msg_N ("small already given for &", Nam);
1500 elsif Small > Delta_Value (U_Ent) then
1502 ("small value must not be greater then delta value", Nam);
1505 Set_Small_Value (U_Ent, Small);
1506 Set_Small_Value (Implicit_Base, Small);
1507 Set_Has_Small_Clause (U_Ent);
1508 Set_Has_Small_Clause (Implicit_Base);
1509 Set_Has_Non_Standard_Rep (Implicit_Base);
1517 -- Storage_Pool attribute definition clause
1519 when Attribute_Storage_Pool => Storage_Pool : declare
1524 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1526 ("storage pool cannot be given for access-to-subprogram type",
1530 elsif Ekind (U_Ent) /= E_Access_Type
1531 and then Ekind (U_Ent) /= E_General_Access_Type
1534 ("storage pool can only be given for access types", Nam);
1537 elsif Is_Derived_Type (U_Ent) then
1539 ("storage pool cannot be given for a derived access type",
1542 elsif Has_Storage_Size_Clause (U_Ent) then
1543 Error_Msg_N ("storage size already given for &", Nam);
1546 elsif Present (Associated_Storage_Pool (U_Ent)) then
1547 Error_Msg_N ("storage pool already given for &", Nam);
1552 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1554 if not Denotes_Variable (Expr) then
1555 Error_Msg_N ("storage pool must be a variable", Expr);
1559 if Nkind (Expr) = N_Type_Conversion then
1560 T := Etype (Expression (Expr));
1565 -- The Stack_Bounded_Pool is used internally for implementing
1566 -- access types with a Storage_Size. Since it only work
1567 -- properly when used on one specific type, we need to check
1568 -- that it is not hijacked improperly:
1569 -- type T is access Integer;
1570 -- for T'Storage_Size use n;
1571 -- type Q is access Float;
1572 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1574 if RTE_Available (RE_Stack_Bounded_Pool)
1575 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1577 Error_Msg_N ("non-shareable internal Pool", Expr);
1581 -- If the argument is a name that is not an entity name, then
1582 -- we construct a renaming operation to define an entity of
1583 -- type storage pool.
1585 if not Is_Entity_Name (Expr)
1586 and then Is_Object_Reference (Expr)
1589 Make_Defining_Identifier (Loc,
1590 Chars => New_Internal_Name ('P'));
1593 Rnode : constant Node_Id :=
1594 Make_Object_Renaming_Declaration (Loc,
1595 Defining_Identifier => Pool,
1597 New_Occurrence_Of (Etype (Expr), Loc),
1601 Insert_Before (N, Rnode);
1603 Set_Associated_Storage_Pool (U_Ent, Pool);
1606 elsif Is_Entity_Name (Expr) then
1607 Pool := Entity (Expr);
1609 -- If pool is a renamed object, get original one. This can
1610 -- happen with an explicit renaming, and within instances.
1612 while Present (Renamed_Object (Pool))
1613 and then Is_Entity_Name (Renamed_Object (Pool))
1615 Pool := Entity (Renamed_Object (Pool));
1618 if Present (Renamed_Object (Pool))
1619 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1620 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1622 Pool := Entity (Expression (Renamed_Object (Pool)));
1625 Set_Associated_Storage_Pool (U_Ent, Pool);
1627 elsif Nkind (Expr) = N_Type_Conversion
1628 and then Is_Entity_Name (Expression (Expr))
1629 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1631 Pool := Entity (Expression (Expr));
1632 Set_Associated_Storage_Pool (U_Ent, Pool);
1635 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1644 -- Storage_Size attribute definition clause
1646 when Attribute_Storage_Size => Storage_Size : declare
1647 Btype : constant Entity_Id := Base_Type (U_Ent);
1651 if Is_Task_Type (U_Ent) then
1652 Check_Restriction (No_Obsolescent_Features, N);
1654 if Warn_On_Obsolescent_Feature then
1656 ("storage size clause for task is an " &
1657 "obsolescent feature (RM J.9)?", N);
1659 ("\use Storage_Size pragma instead?", N);
1665 if not Is_Access_Type (U_Ent)
1666 and then Ekind (U_Ent) /= E_Task_Type
1668 Error_Msg_N ("storage size cannot be given for &", Nam);
1670 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1672 ("storage size cannot be given for a derived access type",
1675 elsif Has_Storage_Size_Clause (Btype) then
1676 Error_Msg_N ("storage size already given for &", Nam);
1679 Analyze_And_Resolve (Expr, Any_Integer);
1681 if Is_Access_Type (U_Ent) then
1682 if Present (Associated_Storage_Pool (U_Ent)) then
1683 Error_Msg_N ("storage pool already given for &", Nam);
1687 if Compile_Time_Known_Value (Expr)
1688 and then Expr_Value (Expr) = 0
1690 Set_No_Pool_Assigned (Btype);
1693 else -- Is_Task_Type (U_Ent)
1694 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1696 if Present (Sprag) then
1697 Error_Msg_Sloc := Sloc (Sprag);
1699 ("Storage_Size already specified#", Nam);
1704 Set_Has_Storage_Size_Clause (Btype);
1712 when Attribute_Stream_Size => Stream_Size : declare
1713 Size : constant Uint := Static_Integer (Expr);
1716 if Ada_Version <= Ada_95 then
1717 Check_Restriction (No_Implementation_Attributes, N);
1720 if Has_Stream_Size_Clause (U_Ent) then
1721 Error_Msg_N ("Stream_Size already given for &", Nam);
1723 elsif Is_Elementary_Type (U_Ent) then
1724 if Size /= System_Storage_Unit
1726 Size /= System_Storage_Unit * 2
1728 Size /= System_Storage_Unit * 4
1730 Size /= System_Storage_Unit * 8
1732 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1734 ("stream size for elementary type must be a"
1735 & " power of 2 and at least ^", N);
1737 elsif RM_Size (U_Ent) > Size then
1738 Error_Msg_Uint_1 := RM_Size (U_Ent);
1740 ("stream size for elementary type must be a"
1741 & " power of 2 and at least ^", N);
1744 Set_Has_Stream_Size_Clause (U_Ent);
1747 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1755 -- Value_Size attribute definition clause
1757 when Attribute_Value_Size => Value_Size : declare
1758 Size : constant Uint := Static_Integer (Expr);
1762 if not Is_Type (U_Ent) then
1763 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1766 (Get_Attribute_Definition_Clause
1767 (U_Ent, Attribute_Value_Size))
1769 Error_Msg_N ("Value_Size already given for &", Nam);
1771 elsif Is_Array_Type (U_Ent)
1772 and then not Is_Constrained (U_Ent)
1775 ("Value_Size cannot be given for unconstrained array", Nam);
1778 if Is_Elementary_Type (U_Ent) then
1779 Check_Size (Expr, U_Ent, Size, Biased);
1780 Set_Has_Biased_Representation (U_Ent, Biased);
1782 if Biased and Warn_On_Biased_Representation then
1784 ("?value size clause forces biased representation", N);
1788 Set_RM_Size (U_Ent, Size);
1796 when Attribute_Write =>
1797 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1798 Set_Has_Specified_Stream_Write (Ent);
1800 -- All other attributes cannot be set
1804 ("attribute& cannot be set with definition clause", N);
1807 -- The test for the type being frozen must be performed after
1808 -- any expression the clause has been analyzed since the expression
1809 -- itself might cause freezing that makes the clause illegal.
1811 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1814 end Analyze_Attribute_Definition_Clause;
1816 ----------------------------
1817 -- Analyze_Code_Statement --
1818 ----------------------------
1820 procedure Analyze_Code_Statement (N : Node_Id) is
1821 HSS : constant Node_Id := Parent (N);
1822 SBody : constant Node_Id := Parent (HSS);
1823 Subp : constant Entity_Id := Current_Scope;
1830 -- Analyze and check we get right type, note that this implements the
1831 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1832 -- is the only way that Asm_Insn could possibly be visible.
1834 Analyze_And_Resolve (Expression (N));
1836 if Etype (Expression (N)) = Any_Type then
1838 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1839 Error_Msg_N ("incorrect type for code statement", N);
1843 Check_Code_Statement (N);
1845 -- Make sure we appear in the handled statement sequence of a
1846 -- subprogram (RM 13.8(3)).
1848 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
1849 or else Nkind (SBody) /= N_Subprogram_Body
1852 ("code statement can only appear in body of subprogram", N);
1856 -- Do remaining checks (RM 13.8(3)) if not already done
1858 if not Is_Machine_Code_Subprogram (Subp) then
1859 Set_Is_Machine_Code_Subprogram (Subp);
1861 -- No exception handlers allowed
1863 if Present (Exception_Handlers (HSS)) then
1865 ("exception handlers not permitted in machine code subprogram",
1866 First (Exception_Handlers (HSS)));
1869 -- No declarations other than use clauses and pragmas (we allow
1870 -- certain internally generated declarations as well).
1872 Decl := First (Declarations (SBody));
1873 while Present (Decl) loop
1874 DeclO := Original_Node (Decl);
1875 if Comes_From_Source (DeclO)
1876 and not Nkind_In (DeclO, N_Pragma,
1877 N_Use_Package_Clause,
1879 N_Implicit_Label_Declaration)
1882 ("this declaration not allowed in machine code subprogram",
1889 -- No statements other than code statements, pragmas, and labels.
1890 -- Again we allow certain internally generated statements.
1892 Stmt := First (Statements (HSS));
1893 while Present (Stmt) loop
1894 StmtO := Original_Node (Stmt);
1895 if Comes_From_Source (StmtO)
1896 and then not Nkind_In (StmtO, N_Pragma,
1901 ("this statement is not allowed in machine code subprogram",
1908 end Analyze_Code_Statement;
1910 -----------------------------------------------
1911 -- Analyze_Enumeration_Representation_Clause --
1912 -----------------------------------------------
1914 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
1915 Ident : constant Node_Id := Identifier (N);
1916 Aggr : constant Node_Id := Array_Aggregate (N);
1917 Enumtype : Entity_Id;
1923 Err : Boolean := False;
1925 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
1926 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
1931 if Ignore_Rep_Clauses then
1935 -- First some basic error checks
1938 Enumtype := Entity (Ident);
1940 if Enumtype = Any_Type
1941 or else Rep_Item_Too_Early (Enumtype, N)
1945 Enumtype := Underlying_Type (Enumtype);
1948 if not Is_Enumeration_Type (Enumtype) then
1950 ("enumeration type required, found}",
1951 Ident, First_Subtype (Enumtype));
1955 -- Ignore rep clause on generic actual type. This will already have
1956 -- been flagged on the template as an error, and this is the safest
1957 -- way to ensure we don't get a junk cascaded message in the instance.
1959 if Is_Generic_Actual_Type (Enumtype) then
1962 -- Type must be in current scope
1964 elsif Scope (Enumtype) /= Current_Scope then
1965 Error_Msg_N ("type must be declared in this scope", Ident);
1968 -- Type must be a first subtype
1970 elsif not Is_First_Subtype (Enumtype) then
1971 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
1974 -- Ignore duplicate rep clause
1976 elsif Has_Enumeration_Rep_Clause (Enumtype) then
1977 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
1980 -- Don't allow rep clause for standard [wide_[wide_]]character
1982 elsif Is_Standard_Character_Type (Enumtype) then
1983 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
1986 -- Check that the expression is a proper aggregate (no parentheses)
1988 elsif Paren_Count (Aggr) /= 0 then
1990 ("extra parentheses surrounding aggregate not allowed",
1994 -- All tests passed, so set rep clause in place
1997 Set_Has_Enumeration_Rep_Clause (Enumtype);
1998 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2001 -- Now we process the aggregate. Note that we don't use the normal
2002 -- aggregate code for this purpose, because we don't want any of the
2003 -- normal expansion activities, and a number of special semantic
2004 -- rules apply (including the component type being any integer type)
2006 Elit := First_Literal (Enumtype);
2008 -- First the positional entries if any
2010 if Present (Expressions (Aggr)) then
2011 Expr := First (Expressions (Aggr));
2012 while Present (Expr) loop
2014 Error_Msg_N ("too many entries in aggregate", Expr);
2018 Val := Static_Integer (Expr);
2020 -- Err signals that we found some incorrect entries processing
2021 -- the list. The final checks for completeness and ordering are
2022 -- skipped in this case.
2024 if Val = No_Uint then
2026 elsif Val < Lo or else Hi < Val then
2027 Error_Msg_N ("value outside permitted range", Expr);
2031 Set_Enumeration_Rep (Elit, Val);
2032 Set_Enumeration_Rep_Expr (Elit, Expr);
2038 -- Now process the named entries if present
2040 if Present (Component_Associations (Aggr)) then
2041 Assoc := First (Component_Associations (Aggr));
2042 while Present (Assoc) loop
2043 Choice := First (Choices (Assoc));
2045 if Present (Next (Choice)) then
2047 ("multiple choice not allowed here", Next (Choice));
2051 if Nkind (Choice) = N_Others_Choice then
2052 Error_Msg_N ("others choice not allowed here", Choice);
2055 elsif Nkind (Choice) = N_Range then
2056 -- ??? should allow zero/one element range here
2057 Error_Msg_N ("range not allowed here", Choice);
2061 Analyze_And_Resolve (Choice, Enumtype);
2063 if Is_Entity_Name (Choice)
2064 and then Is_Type (Entity (Choice))
2066 Error_Msg_N ("subtype name not allowed here", Choice);
2068 -- ??? should allow static subtype with zero/one entry
2070 elsif Etype (Choice) = Base_Type (Enumtype) then
2071 if not Is_Static_Expression (Choice) then
2072 Flag_Non_Static_Expr
2073 ("non-static expression used for choice!", Choice);
2077 Elit := Expr_Value_E (Choice);
2079 if Present (Enumeration_Rep_Expr (Elit)) then
2080 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2082 ("representation for& previously given#",
2087 Set_Enumeration_Rep_Expr (Elit, Choice);
2089 Expr := Expression (Assoc);
2090 Val := Static_Integer (Expr);
2092 if Val = No_Uint then
2095 elsif Val < Lo or else Hi < Val then
2096 Error_Msg_N ("value outside permitted range", Expr);
2100 Set_Enumeration_Rep (Elit, Val);
2109 -- Aggregate is fully processed. Now we check that a full set of
2110 -- representations was given, and that they are in range and in order.
2111 -- These checks are only done if no other errors occurred.
2117 Elit := First_Literal (Enumtype);
2118 while Present (Elit) loop
2119 if No (Enumeration_Rep_Expr (Elit)) then
2120 Error_Msg_NE ("missing representation for&!", N, Elit);
2123 Val := Enumeration_Rep (Elit);
2125 if Min = No_Uint then
2129 if Val /= No_Uint then
2130 if Max /= No_Uint and then Val <= Max then
2132 ("enumeration value for& not ordered!",
2133 Enumeration_Rep_Expr (Elit), Elit);
2139 -- If there is at least one literal whose representation
2140 -- is not equal to the Pos value, then note that this
2141 -- enumeration type has a non-standard representation.
2143 if Val /= Enumeration_Pos (Elit) then
2144 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2151 -- Now set proper size information
2154 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2157 if Has_Size_Clause (Enumtype) then
2158 if Esize (Enumtype) >= Minsize then
2163 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2165 if Esize (Enumtype) < Minsize then
2166 Error_Msg_N ("previously given size is too small", N);
2169 Set_Has_Biased_Representation (Enumtype);
2174 Set_RM_Size (Enumtype, Minsize);
2175 Set_Enum_Esize (Enumtype);
2178 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2179 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2180 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2184 -- We repeat the too late test in case it froze itself!
2186 if Rep_Item_Too_Late (Enumtype, N) then
2189 end Analyze_Enumeration_Representation_Clause;
2191 ----------------------------
2192 -- Analyze_Free_Statement --
2193 ----------------------------
2195 procedure Analyze_Free_Statement (N : Node_Id) is
2197 Analyze (Expression (N));
2198 end Analyze_Free_Statement;
2200 ------------------------------------------
2201 -- Analyze_Record_Representation_Clause --
2202 ------------------------------------------
2204 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2205 Loc : constant Source_Ptr := Sloc (N);
2206 Ident : constant Node_Id := Identifier (N);
2207 Rectype : Entity_Id;
2213 Hbit : Uint := Uint_0;
2219 Max_Bit_So_Far : Uint;
2220 -- Records the maximum bit position so far. If all field positions
2221 -- are monotonically increasing, then we can skip the circuit for
2222 -- checking for overlap, since no overlap is possible.
2224 Tagged_Parent : Entity_Id := Empty;
2225 -- This is set in the case of a derived tagged type for which we have
2226 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
2227 -- positioned by record representation clauses). In this case we must
2228 -- check for overlap between components of this tagged type, and the
2229 -- components of its parent. Tagged_Parent will point to this parent
2230 -- type. For all other cases Tagged_Parent is left set to Empty.
2232 Parent_Last_Bit : Uint;
2233 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
2234 -- last bit position for any field in the parent type. We only need to
2235 -- check overlap for fields starting below this point.
2237 Overlap_Check_Required : Boolean;
2238 -- Used to keep track of whether or not an overlap check is required
2240 Ccount : Natural := 0;
2241 -- Number of component clauses in record rep clause
2243 CR_Pragma : Node_Id := Empty;
2244 -- Points to N_Pragma node if Complete_Representation pragma present
2247 if Ignore_Rep_Clauses then
2252 Rectype := Entity (Ident);
2254 if Rectype = Any_Type
2255 or else Rep_Item_Too_Early (Rectype, N)
2259 Rectype := Underlying_Type (Rectype);
2262 -- First some basic error checks
2264 if not Is_Record_Type (Rectype) then
2266 ("record type required, found}", Ident, First_Subtype (Rectype));
2269 elsif Is_Unchecked_Union (Rectype) then
2271 ("record rep clause not allowed for Unchecked_Union", N);
2273 elsif Scope (Rectype) /= Current_Scope then
2274 Error_Msg_N ("type must be declared in this scope", N);
2277 elsif not Is_First_Subtype (Rectype) then
2278 Error_Msg_N ("cannot give record rep clause for subtype", N);
2281 elsif Has_Record_Rep_Clause (Rectype) then
2282 Error_Msg_N ("duplicate record rep clause ignored", N);
2285 elsif Rep_Item_Too_Late (Rectype, N) then
2289 if Present (Mod_Clause (N)) then
2291 Loc : constant Source_Ptr := Sloc (N);
2292 M : constant Node_Id := Mod_Clause (N);
2293 P : constant List_Id := Pragmas_Before (M);
2297 pragma Warnings (Off, Mod_Val);
2300 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2302 if Warn_On_Obsolescent_Feature then
2304 ("mod clause is an obsolescent feature (RM J.8)?", N);
2306 ("\use alignment attribute definition clause instead?", N);
2313 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2314 -- the Mod clause into an alignment clause anyway, so that the
2315 -- back-end can compute and back-annotate properly the size and
2316 -- alignment of types that may include this record.
2318 -- This seems dubious, this destroys the source tree in a manner
2319 -- not detectable by ASIS ???
2321 if Operating_Mode = Check_Semantics
2325 Make_Attribute_Definition_Clause (Loc,
2326 Name => New_Reference_To (Base_Type (Rectype), Loc),
2327 Chars => Name_Alignment,
2328 Expression => Relocate_Node (Expression (M)));
2330 Set_From_At_Mod (AtM_Nod);
2331 Insert_After (N, AtM_Nod);
2332 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2333 Set_Mod_Clause (N, Empty);
2336 -- Get the alignment value to perform error checking
2338 Mod_Val := Get_Alignment_Value (Expression (M));
2344 -- For untagged types, clear any existing component clauses for the
2345 -- type. If the type is derived, this is what allows us to override
2346 -- a rep clause for the parent. For type extensions, the representation
2347 -- of the inherited components is inherited, so we want to keep previous
2348 -- component clauses for completeness.
2350 if not Is_Tagged_Type (Rectype) then
2351 Comp := First_Component_Or_Discriminant (Rectype);
2352 while Present (Comp) loop
2353 Set_Component_Clause (Comp, Empty);
2354 Next_Component_Or_Discriminant (Comp);
2358 -- See if we have a fully repped derived tagged type
2361 PS : constant Entity_Id := Parent_Subtype (Rectype);
2364 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
2365 Tagged_Parent := PS;
2367 -- Find maximum bit of any component of the parent type
2369 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
2370 Pcomp := First_Entity (Tagged_Parent);
2371 while Present (Pcomp) loop
2372 if Ekind (Pcomp) = E_Discriminant
2374 Ekind (Pcomp) = E_Component
2376 if Component_Bit_Offset (Pcomp) /= No_Uint
2377 and then Known_Static_Esize (Pcomp)
2382 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
2385 Next_Entity (Pcomp);
2391 -- All done if no component clauses
2393 CC := First (Component_Clauses (N));
2399 -- If a tag is present, then create a component clause that places it
2400 -- at the start of the record (otherwise gigi may place it after other
2401 -- fields that have rep clauses).
2403 Fent := First_Entity (Rectype);
2405 if Nkind (Fent) = N_Defining_Identifier
2406 and then Chars (Fent) = Name_uTag
2408 Set_Component_Bit_Offset (Fent, Uint_0);
2409 Set_Normalized_Position (Fent, Uint_0);
2410 Set_Normalized_First_Bit (Fent, Uint_0);
2411 Set_Normalized_Position_Max (Fent, Uint_0);
2412 Init_Esize (Fent, System_Address_Size);
2414 Set_Component_Clause (Fent,
2415 Make_Component_Clause (Loc,
2417 Make_Identifier (Loc,
2418 Chars => Name_uTag),
2421 Make_Integer_Literal (Loc,
2425 Make_Integer_Literal (Loc,
2429 Make_Integer_Literal (Loc,
2430 UI_From_Int (System_Address_Size))));
2432 Ccount := Ccount + 1;
2435 -- A representation like this applies to the base type
2437 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2438 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2439 Set_Has_Specified_Layout (Base_Type (Rectype));
2441 Max_Bit_So_Far := Uint_Minus_1;
2442 Overlap_Check_Required := False;
2444 -- Process the component clauses
2446 while Present (CC) loop
2450 if Nkind (CC) = N_Pragma then
2453 -- The only pragma of interest is Complete_Representation
2455 if Pragma_Name (CC) = Name_Complete_Representation then
2459 -- Processing for real component clause
2462 Ccount := Ccount + 1;
2463 Posit := Static_Integer (Position (CC));
2464 Fbit := Static_Integer (First_Bit (CC));
2465 Lbit := Static_Integer (Last_Bit (CC));
2468 and then Fbit /= No_Uint
2469 and then Lbit /= No_Uint
2473 ("position cannot be negative", Position (CC));
2477 ("first bit cannot be negative", First_Bit (CC));
2479 -- The Last_Bit specified in a component clause must not be
2480 -- less than the First_Bit minus one (RM-13.5.1(10)).
2482 elsif Lbit < Fbit - 1 then
2484 ("last bit cannot be less than first bit minus one",
2487 -- Values look OK, so find the corresponding record component
2488 -- Even though the syntax allows an attribute reference for
2489 -- implementation-defined components, GNAT does not allow the
2490 -- tag to get an explicit position.
2492 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2493 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2494 Error_Msg_N ("position of tag cannot be specified", CC);
2496 Error_Msg_N ("illegal component name", CC);
2500 Comp := First_Entity (Rectype);
2501 while Present (Comp) loop
2502 exit when Chars (Comp) = Chars (Component_Name (CC));
2508 -- Maybe component of base type that is absent from
2509 -- statically constrained first subtype.
2511 Comp := First_Entity (Base_Type (Rectype));
2512 while Present (Comp) loop
2513 exit when Chars (Comp) = Chars (Component_Name (CC));
2520 ("component clause is for non-existent field", CC);
2522 elsif Present (Component_Clause (Comp)) then
2524 -- Diagnose duplicate rep clause, or check consistency
2525 -- if this is an inherited component. In a double fault,
2526 -- there may be a duplicate inconsistent clause for an
2527 -- inherited component.
2529 if Scope (Original_Record_Component (Comp)) = Rectype
2530 or else Parent (Component_Clause (Comp)) = N
2532 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2533 Error_Msg_N ("component clause previously given#", CC);
2537 Rep1 : constant Node_Id := Component_Clause (Comp);
2539 if Intval (Position (Rep1)) /=
2540 Intval (Position (CC))
2541 or else Intval (First_Bit (Rep1)) /=
2542 Intval (First_Bit (CC))
2543 or else Intval (Last_Bit (Rep1)) /=
2544 Intval (Last_Bit (CC))
2546 Error_Msg_N ("component clause inconsistent "
2547 & "with representation of ancestor", CC);
2548 elsif Warn_On_Redundant_Constructs then
2549 Error_Msg_N ("?redundant component clause "
2550 & "for inherited component!", CC);
2555 -- Normal case where this is the first component clause we
2556 -- have seen for this entity, so set it up properly.
2559 -- Make reference for field in record rep clause and set
2560 -- appropriate entity field in the field identifier.
2563 (Comp, Component_Name (CC), Set_Ref => False);
2564 Set_Entity (Component_Name (CC), Comp);
2566 -- Update Fbit and Lbit to the actual bit number
2568 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2569 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2571 if Fbit <= Max_Bit_So_Far then
2572 Overlap_Check_Required := True;
2574 Max_Bit_So_Far := Lbit;
2577 if Has_Size_Clause (Rectype)
2578 and then Esize (Rectype) <= Lbit
2581 ("bit number out of range of specified size",
2584 Set_Component_Clause (Comp, CC);
2585 Set_Component_Bit_Offset (Comp, Fbit);
2586 Set_Esize (Comp, 1 + (Lbit - Fbit));
2587 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2588 Set_Normalized_Position (Comp, Fbit / SSU);
2590 Set_Normalized_Position_Max
2591 (Fent, Normalized_Position (Fent));
2593 if Is_Tagged_Type (Rectype)
2594 and then Fbit < System_Address_Size
2597 ("component overlaps tag field of&",
2598 Component_Name (CC), Rectype);
2601 -- This information is also set in the corresponding
2602 -- component of the base type, found by accessing the
2603 -- Original_Record_Component link if it is present.
2605 Ocomp := Original_Record_Component (Comp);
2612 (Component_Name (CC),
2617 Set_Has_Biased_Representation (Comp, Biased);
2619 if Biased and Warn_On_Biased_Representation then
2621 ("?component clause forces biased "
2622 & "representation", CC);
2625 if Present (Ocomp) then
2626 Set_Component_Clause (Ocomp, CC);
2627 Set_Component_Bit_Offset (Ocomp, Fbit);
2628 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2629 Set_Normalized_Position (Ocomp, Fbit / SSU);
2630 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2632 Set_Normalized_Position_Max
2633 (Ocomp, Normalized_Position (Ocomp));
2635 Set_Has_Biased_Representation
2636 (Ocomp, Has_Biased_Representation (Comp));
2639 if Esize (Comp) < 0 then
2640 Error_Msg_N ("component size is negative", CC);
2644 -- If OK component size, check parent type overlap if
2645 -- this component might overlap a parent field.
2647 if Present (Tagged_Parent)
2648 and then Fbit <= Parent_Last_Bit
2650 Pcomp := First_Entity (Tagged_Parent);
2651 while Present (Pcomp) loop
2652 if (Ekind (Pcomp) = E_Discriminant
2654 Ekind (Pcomp) = E_Component)
2655 and then not Is_Tag (Pcomp)
2656 and then Chars (Pcomp) /= Name_uParent
2658 Check_Component_Overlap (Comp, Pcomp);
2661 Next_Entity (Pcomp);
2672 -- Now that we have processed all the component clauses, check for
2673 -- overlap. We have to leave this till last, since the components can
2674 -- appear in any arbitrary order in the representation clause.
2676 -- We do not need this check if all specified ranges were monotonic,
2677 -- as recorded by Overlap_Check_Required being False at this stage.
2679 -- This first section checks if there are any overlapping entries at
2680 -- all. It does this by sorting all entries and then seeing if there are
2681 -- any overlaps. If there are none, then that is decisive, but if there
2682 -- are overlaps, they may still be OK (they may result from fields in
2683 -- different variants).
2685 if Overlap_Check_Required then
2686 Overlap_Check1 : declare
2688 OC_Fbit : array (0 .. Ccount) of Uint;
2689 -- First-bit values for component clauses, the value is the offset
2690 -- of the first bit of the field from start of record. The zero
2691 -- entry is for use in sorting.
2693 OC_Lbit : array (0 .. Ccount) of Uint;
2694 -- Last-bit values for component clauses, the value is the offset
2695 -- of the last bit of the field from start of record. The zero
2696 -- entry is for use in sorting.
2698 OC_Count : Natural := 0;
2699 -- Count of entries in OC_Fbit and OC_Lbit
2701 function OC_Lt (Op1, Op2 : Natural) return Boolean;
2702 -- Compare routine for Sort
2704 procedure OC_Move (From : Natural; To : Natural);
2705 -- Move routine for Sort
2707 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
2713 function OC_Lt (Op1, Op2 : Natural) return Boolean is
2715 return OC_Fbit (Op1) < OC_Fbit (Op2);
2722 procedure OC_Move (From : Natural; To : Natural) is
2724 OC_Fbit (To) := OC_Fbit (From);
2725 OC_Lbit (To) := OC_Lbit (From);
2728 -- Start of processing for Overlap_Check
2731 CC := First (Component_Clauses (N));
2732 while Present (CC) loop
2733 if Nkind (CC) /= N_Pragma then
2734 Posit := Static_Integer (Position (CC));
2735 Fbit := Static_Integer (First_Bit (CC));
2736 Lbit := Static_Integer (Last_Bit (CC));
2739 and then Fbit /= No_Uint
2740 and then Lbit /= No_Uint
2742 OC_Count := OC_Count + 1;
2743 Posit := Posit * SSU;
2744 OC_Fbit (OC_Count) := Fbit + Posit;
2745 OC_Lbit (OC_Count) := Lbit + Posit;
2752 Sorting.Sort (OC_Count);
2754 Overlap_Check_Required := False;
2755 for J in 1 .. OC_Count - 1 loop
2756 if OC_Lbit (J) >= OC_Fbit (J + 1) then
2757 Overlap_Check_Required := True;
2764 -- If Overlap_Check_Required is still True, then we have to do the full
2765 -- scale overlap check, since we have at least two fields that do
2766 -- overlap, and we need to know if that is OK since they are in
2767 -- different variant, or whether we have a definite problem.
2769 if Overlap_Check_Required then
2770 Overlap_Check2 : declare
2771 C1_Ent, C2_Ent : Entity_Id;
2772 -- Entities of components being checked for overlap
2775 -- Component_List node whose Component_Items are being checked
2778 -- Component declaration for component being checked
2781 C1_Ent := First_Entity (Base_Type (Rectype));
2783 -- Loop through all components in record. For each component check
2784 -- for overlap with any of the preceding elements on the component
2785 -- list containing the component and also, if the component is in
2786 -- a variant, check against components outside the case structure.
2787 -- This latter test is repeated recursively up the variant tree.
2789 Main_Component_Loop : while Present (C1_Ent) loop
2790 if Ekind (C1_Ent) /= E_Component
2791 and then Ekind (C1_Ent) /= E_Discriminant
2793 goto Continue_Main_Component_Loop;
2796 -- Skip overlap check if entity has no declaration node. This
2797 -- happens with discriminants in constrained derived types.
2798 -- Probably we are missing some checks as a result, but that
2799 -- does not seem terribly serious ???
2801 if No (Declaration_Node (C1_Ent)) then
2802 goto Continue_Main_Component_Loop;
2805 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
2807 -- Loop through component lists that need checking. Check the
2808 -- current component list and all lists in variants above us.
2810 Component_List_Loop : loop
2812 -- If derived type definition, go to full declaration
2813 -- If at outer level, check discriminants if there are any.
2815 if Nkind (Clist) = N_Derived_Type_Definition then
2816 Clist := Parent (Clist);
2819 -- Outer level of record definition, check discriminants
2821 if Nkind_In (Clist, N_Full_Type_Declaration,
2822 N_Private_Type_Declaration)
2824 if Has_Discriminants (Defining_Identifier (Clist)) then
2826 First_Discriminant (Defining_Identifier (Clist));
2827 while Present (C2_Ent) loop
2828 exit when C1_Ent = C2_Ent;
2829 Check_Component_Overlap (C1_Ent, C2_Ent);
2830 Next_Discriminant (C2_Ent);
2834 -- Record extension case
2836 elsif Nkind (Clist) = N_Derived_Type_Definition then
2839 -- Otherwise check one component list
2842 Citem := First (Component_Items (Clist));
2844 while Present (Citem) loop
2845 if Nkind (Citem) = N_Component_Declaration then
2846 C2_Ent := Defining_Identifier (Citem);
2847 exit when C1_Ent = C2_Ent;
2848 Check_Component_Overlap (C1_Ent, C2_Ent);
2855 -- Check for variants above us (the parent of the Clist can
2856 -- be a variant, in which case its parent is a variant part,
2857 -- and the parent of the variant part is a component list
2858 -- whose components must all be checked against the current
2859 -- component for overlap).
2861 if Nkind (Parent (Clist)) = N_Variant then
2862 Clist := Parent (Parent (Parent (Clist)));
2864 -- Check for possible discriminant part in record, this is
2865 -- treated essentially as another level in the recursion.
2866 -- For this case the parent of the component list is the
2867 -- record definition, and its parent is the full type
2868 -- declaration containing the discriminant specifications.
2870 elsif Nkind (Parent (Clist)) = N_Record_Definition then
2871 Clist := Parent (Parent ((Clist)));
2873 -- If neither of these two cases, we are at the top of
2877 exit Component_List_Loop;
2879 end loop Component_List_Loop;
2881 <<Continue_Main_Component_Loop>>
2882 Next_Entity (C1_Ent);
2884 end loop Main_Component_Loop;
2888 -- For records that have component clauses for all components, and whose
2889 -- size is less than or equal to 32, we need to know the size in the
2890 -- front end to activate possible packed array processing where the
2891 -- component type is a record.
2893 -- At this stage Hbit + 1 represents the first unused bit from all the
2894 -- component clauses processed, so if the component clauses are
2895 -- complete, then this is the length of the record.
2897 -- For records longer than System.Storage_Unit, and for those where not
2898 -- all components have component clauses, the back end determines the
2899 -- length (it may for example be appropriate to round up the size
2900 -- to some convenient boundary, based on alignment considerations, etc).
2902 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
2904 -- Nothing to do if at least one component has no component clause
2906 Comp := First_Component_Or_Discriminant (Rectype);
2907 while Present (Comp) loop
2908 exit when No (Component_Clause (Comp));
2909 Next_Component_Or_Discriminant (Comp);
2912 -- If we fall out of loop, all components have component clauses
2913 -- and so we can set the size to the maximum value.
2916 Set_RM_Size (Rectype, Hbit + 1);
2920 -- Check missing components if Complete_Representation pragma appeared
2922 if Present (CR_Pragma) then
2923 Comp := First_Component_Or_Discriminant (Rectype);
2924 while Present (Comp) loop
2925 if No (Component_Clause (Comp)) then
2927 ("missing component clause for &", CR_Pragma, Comp);
2930 Next_Component_Or_Discriminant (Comp);
2933 -- If no Complete_Representation pragma, warn if missing components
2935 elsif Warn_On_Unrepped_Components then
2937 Num_Repped_Components : Nat := 0;
2938 Num_Unrepped_Components : Nat := 0;
2941 -- First count number of repped and unrepped components
2943 Comp := First_Component_Or_Discriminant (Rectype);
2944 while Present (Comp) loop
2945 if Present (Component_Clause (Comp)) then
2946 Num_Repped_Components := Num_Repped_Components + 1;
2948 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2951 Next_Component_Or_Discriminant (Comp);
2954 -- We are only interested in the case where there is at least one
2955 -- unrepped component, and at least half the components have rep
2956 -- clauses. We figure that if less than half have them, then the
2957 -- partial rep clause is really intentional. If the component
2958 -- type has no underlying type set at this point (as for a generic
2959 -- formal type), we don't know enough to give a warning on the
2962 if Num_Unrepped_Components > 0
2963 and then Num_Unrepped_Components < Num_Repped_Components
2965 Comp := First_Component_Or_Discriminant (Rectype);
2966 while Present (Comp) loop
2967 if No (Component_Clause (Comp))
2968 and then Comes_From_Source (Comp)
2969 and then Present (Underlying_Type (Etype (Comp)))
2970 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2971 or else Size_Known_At_Compile_Time
2972 (Underlying_Type (Etype (Comp))))
2973 and then not Has_Warnings_Off (Rectype)
2975 Error_Msg_Sloc := Sloc (Comp);
2977 ("?no component clause given for & declared #",
2981 Next_Component_Or_Discriminant (Comp);
2986 end Analyze_Record_Representation_Clause;
2988 -----------------------------
2989 -- Check_Component_Overlap --
2990 -----------------------------
2992 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
2994 if Present (Component_Clause (C1_Ent))
2995 and then Present (Component_Clause (C2_Ent))
2997 -- Exclude odd case where we have two tag fields in the same record,
2998 -- both at location zero. This seems a bit strange, but it seems to
2999 -- happen in some circumstances ???
3001 if Chars (C1_Ent) = Name_uTag
3002 and then Chars (C2_Ent) = Name_uTag
3007 -- Here we check if the two fields overlap
3010 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
3011 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
3012 E1 : constant Uint := S1 + Esize (C1_Ent);
3013 E2 : constant Uint := S2 + Esize (C2_Ent);
3016 if E2 <= S1 or else E1 <= S2 then
3020 Component_Name (Component_Clause (C2_Ent));
3021 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
3023 Component_Name (Component_Clause (C1_Ent));
3025 ("component& overlaps & #",
3026 Component_Name (Component_Clause (C1_Ent)));
3030 end Check_Component_Overlap;
3032 -----------------------------------
3033 -- Check_Constant_Address_Clause --
3034 -----------------------------------
3036 procedure Check_Constant_Address_Clause
3040 procedure Check_At_Constant_Address (Nod : Node_Id);
3041 -- Checks that the given node N represents a name whose 'Address is
3042 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
3043 -- address value is the same at the point of declaration of U_Ent and at
3044 -- the time of elaboration of the address clause.
3046 procedure Check_Expr_Constants (Nod : Node_Id);
3047 -- Checks that Nod meets the requirements for a constant address clause
3048 -- in the sense of the enclosing procedure.
3050 procedure Check_List_Constants (Lst : List_Id);
3051 -- Check that all elements of list Lst meet the requirements for a
3052 -- constant address clause in the sense of the enclosing procedure.
3054 -------------------------------
3055 -- Check_At_Constant_Address --
3056 -------------------------------
3058 procedure Check_At_Constant_Address (Nod : Node_Id) is
3060 if Is_Entity_Name (Nod) then
3061 if Present (Address_Clause (Entity ((Nod)))) then
3063 ("invalid address clause for initialized object &!",
3066 ("address for& cannot" &
3067 " depend on another address clause! (RM 13.1(22))!",
3070 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
3071 and then Sloc (U_Ent) < Sloc (Entity (Nod))
3074 ("invalid address clause for initialized object &!",
3076 Error_Msg_Node_2 := U_Ent;
3078 ("\& must be defined before & (RM 13.1(22))!",
3082 elsif Nkind (Nod) = N_Selected_Component then
3084 T : constant Entity_Id := Etype (Prefix (Nod));
3087 if (Is_Record_Type (T)
3088 and then Has_Discriminants (T))
3091 and then Is_Record_Type (Designated_Type (T))
3092 and then Has_Discriminants (Designated_Type (T)))
3095 ("invalid address clause for initialized object &!",
3098 ("\address cannot depend on component" &
3099 " of discriminated record (RM 13.1(22))!",
3102 Check_At_Constant_Address (Prefix (Nod));
3106 elsif Nkind (Nod) = N_Indexed_Component then
3107 Check_At_Constant_Address (Prefix (Nod));
3108 Check_List_Constants (Expressions (Nod));
3111 Check_Expr_Constants (Nod);
3113 end Check_At_Constant_Address;
3115 --------------------------
3116 -- Check_Expr_Constants --
3117 --------------------------
3119 procedure Check_Expr_Constants (Nod : Node_Id) is
3120 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
3121 Ent : Entity_Id := Empty;
3124 if Nkind (Nod) in N_Has_Etype
3125 and then Etype (Nod) = Any_Type
3131 when N_Empty | N_Error =>
3134 when N_Identifier | N_Expanded_Name =>
3135 Ent := Entity (Nod);
3137 -- We need to look at the original node if it is different
3138 -- from the node, since we may have rewritten things and
3139 -- substituted an identifier representing the rewrite.
3141 if Original_Node (Nod) /= Nod then
3142 Check_Expr_Constants (Original_Node (Nod));
3144 -- If the node is an object declaration without initial
3145 -- value, some code has been expanded, and the expression
3146 -- is not constant, even if the constituents might be
3147 -- acceptable, as in A'Address + offset.
3149 if Ekind (Ent) = E_Variable
3151 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3153 No (Expression (Declaration_Node (Ent)))
3156 ("invalid address clause for initialized object &!",
3159 -- If entity is constant, it may be the result of expanding
3160 -- a check. We must verify that its declaration appears
3161 -- before the object in question, else we also reject the
3164 elsif Ekind (Ent) = E_Constant
3165 and then In_Same_Source_Unit (Ent, U_Ent)
3166 and then Sloc (Ent) > Loc_U_Ent
3169 ("invalid address clause for initialized object &!",
3176 -- Otherwise look at the identifier and see if it is OK
3178 if Ekind (Ent) = E_Named_Integer
3180 Ekind (Ent) = E_Named_Real
3187 Ekind (Ent) = E_Constant
3189 Ekind (Ent) = E_In_Parameter
3191 -- This is the case where we must have Ent defined before
3192 -- U_Ent. Clearly if they are in different units this
3193 -- requirement is met since the unit containing Ent is
3194 -- already processed.
3196 if not In_Same_Source_Unit (Ent, U_Ent) then
3199 -- Otherwise location of Ent must be before the location
3200 -- of U_Ent, that's what prior defined means.
3202 elsif Sloc (Ent) < Loc_U_Ent then
3207 ("invalid address clause for initialized object &!",
3209 Error_Msg_Node_2 := U_Ent;
3211 ("\& must be defined before & (RM 13.1(22))!",
3215 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3216 Check_Expr_Constants (Original_Node (Nod));
3220 ("invalid address clause for initialized object &!",
3223 if Comes_From_Source (Ent) then
3225 ("\reference to variable& not allowed"
3226 & " (RM 13.1(22))!", Nod, Ent);
3229 ("non-static expression not allowed"
3230 & " (RM 13.1(22))!", Nod);
3234 when N_Integer_Literal =>
3236 -- If this is a rewritten unchecked conversion, in a system
3237 -- where Address is an integer type, always use the base type
3238 -- for a literal value. This is user-friendly and prevents
3239 -- order-of-elaboration issues with instances of unchecked
3242 if Nkind (Original_Node (Nod)) = N_Function_Call then
3243 Set_Etype (Nod, Base_Type (Etype (Nod)));
3246 when N_Real_Literal |
3248 N_Character_Literal =>
3252 Check_Expr_Constants (Low_Bound (Nod));
3253 Check_Expr_Constants (High_Bound (Nod));
3255 when N_Explicit_Dereference =>
3256 Check_Expr_Constants (Prefix (Nod));
3258 when N_Indexed_Component =>
3259 Check_Expr_Constants (Prefix (Nod));
3260 Check_List_Constants (Expressions (Nod));
3263 Check_Expr_Constants (Prefix (Nod));
3264 Check_Expr_Constants (Discrete_Range (Nod));
3266 when N_Selected_Component =>
3267 Check_Expr_Constants (Prefix (Nod));
3269 when N_Attribute_Reference =>
3270 if Attribute_Name (Nod) = Name_Address
3272 Attribute_Name (Nod) = Name_Access
3274 Attribute_Name (Nod) = Name_Unchecked_Access
3276 Attribute_Name (Nod) = Name_Unrestricted_Access
3278 Check_At_Constant_Address (Prefix (Nod));
3281 Check_Expr_Constants (Prefix (Nod));
3282 Check_List_Constants (Expressions (Nod));
3286 Check_List_Constants (Component_Associations (Nod));
3287 Check_List_Constants (Expressions (Nod));
3289 when N_Component_Association =>
3290 Check_Expr_Constants (Expression (Nod));
3292 when N_Extension_Aggregate =>
3293 Check_Expr_Constants (Ancestor_Part (Nod));
3294 Check_List_Constants (Component_Associations (Nod));
3295 Check_List_Constants (Expressions (Nod));
3300 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3301 Check_Expr_Constants (Left_Opnd (Nod));
3302 Check_Expr_Constants (Right_Opnd (Nod));
3305 Check_Expr_Constants (Right_Opnd (Nod));
3307 when N_Type_Conversion |
3308 N_Qualified_Expression |
3310 Check_Expr_Constants (Expression (Nod));
3312 when N_Unchecked_Type_Conversion =>
3313 Check_Expr_Constants (Expression (Nod));
3315 -- If this is a rewritten unchecked conversion, subtypes in
3316 -- this node are those created within the instance. To avoid
3317 -- order of elaboration issues, replace them with their base
3318 -- types. Note that address clauses can cause order of
3319 -- elaboration problems because they are elaborated by the
3320 -- back-end at the point of definition, and may mention
3321 -- entities declared in between (as long as everything is
3322 -- static). It is user-friendly to allow unchecked conversions
3325 if Nkind (Original_Node (Nod)) = N_Function_Call then
3326 Set_Etype (Expression (Nod),
3327 Base_Type (Etype (Expression (Nod))));
3328 Set_Etype (Nod, Base_Type (Etype (Nod)));
3331 when N_Function_Call =>
3332 if not Is_Pure (Entity (Name (Nod))) then
3334 ("invalid address clause for initialized object &!",
3338 ("\function & is not pure (RM 13.1(22))!",
3339 Nod, Entity (Name (Nod)));
3342 Check_List_Constants (Parameter_Associations (Nod));
3345 when N_Parameter_Association =>
3346 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3350 ("invalid address clause for initialized object &!",
3353 ("\must be constant defined before& (RM 13.1(22))!",
3356 end Check_Expr_Constants;
3358 --------------------------
3359 -- Check_List_Constants --
3360 --------------------------
3362 procedure Check_List_Constants (Lst : List_Id) is
3366 if Present (Lst) then
3367 Nod1 := First (Lst);
3368 while Present (Nod1) loop
3369 Check_Expr_Constants (Nod1);
3373 end Check_List_Constants;
3375 -- Start of processing for Check_Constant_Address_Clause
3378 Check_Expr_Constants (Expr);
3379 end Check_Constant_Address_Clause;
3385 procedure Check_Size
3389 Biased : out Boolean)
3391 UT : constant Entity_Id := Underlying_Type (T);
3397 -- Dismiss cases for generic types or types with previous errors
3400 or else UT = Any_Type
3401 or else Is_Generic_Type (UT)
3402 or else Is_Generic_Type (Root_Type (UT))
3406 -- Check case of bit packed array
3408 elsif Is_Array_Type (UT)
3409 and then Known_Static_Component_Size (UT)
3410 and then Is_Bit_Packed_Array (UT)
3418 Asiz := Component_Size (UT);
3419 Indx := First_Index (UT);
3421 Ityp := Etype (Indx);
3423 -- If non-static bound, then we are not in the business of
3424 -- trying to check the length, and indeed an error will be
3425 -- issued elsewhere, since sizes of non-static array types
3426 -- cannot be set implicitly or explicitly.
3428 if not Is_Static_Subtype (Ityp) then
3432 -- Otherwise accumulate next dimension
3434 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
3435 Expr_Value (Type_Low_Bound (Ityp)) +
3439 exit when No (Indx);
3445 Error_Msg_Uint_1 := Asiz;
3447 ("size for& too small, minimum allowed is ^", N, T);
3448 Set_Esize (T, Asiz);
3449 Set_RM_Size (T, Asiz);
3453 -- All other composite types are ignored
3455 elsif Is_Composite_Type (UT) then
3458 -- For fixed-point types, don't check minimum if type is not frozen,
3459 -- since we don't know all the characteristics of the type that can
3460 -- affect the size (e.g. a specified small) till freeze time.
3462 elsif Is_Fixed_Point_Type (UT)
3463 and then not Is_Frozen (UT)
3467 -- Cases for which a minimum check is required
3470 -- Ignore if specified size is correct for the type
3472 if Known_Esize (UT) and then Siz = Esize (UT) then
3476 -- Otherwise get minimum size
3478 M := UI_From_Int (Minimum_Size (UT));
3482 -- Size is less than minimum size, but one possibility remains
3483 -- that we can manage with the new size if we bias the type.
3485 M := UI_From_Int (Minimum_Size (UT, Biased => True));
3488 Error_Msg_Uint_1 := M;
3490 ("size for& too small, minimum allowed is ^", N, T);
3500 -------------------------
3501 -- Get_Alignment_Value --
3502 -------------------------
3504 function Get_Alignment_Value (Expr : Node_Id) return Uint is
3505 Align : constant Uint := Static_Integer (Expr);
3508 if Align = No_Uint then
3511 elsif Align <= 0 then
3512 Error_Msg_N ("alignment value must be positive", Expr);
3516 for J in Int range 0 .. 64 loop
3518 M : constant Uint := Uint_2 ** J;
3521 exit when M = Align;
3525 ("alignment value must be power of 2", Expr);
3533 end Get_Alignment_Value;
3539 procedure Initialize is
3541 Unchecked_Conversions.Init;
3544 -------------------------
3545 -- Is_Operational_Item --
3546 -------------------------
3548 function Is_Operational_Item (N : Node_Id) return Boolean is
3550 if Nkind (N) /= N_Attribute_Definition_Clause then
3554 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
3556 return Id = Attribute_Input
3557 or else Id = Attribute_Output
3558 or else Id = Attribute_Read
3559 or else Id = Attribute_Write
3560 or else Id = Attribute_External_Tag;
3563 end Is_Operational_Item;
3569 function Minimum_Size
3571 Biased : Boolean := False) return Nat
3573 Lo : Uint := No_Uint;
3574 Hi : Uint := No_Uint;
3575 LoR : Ureal := No_Ureal;
3576 HiR : Ureal := No_Ureal;
3577 LoSet : Boolean := False;
3578 HiSet : Boolean := False;
3582 R_Typ : constant Entity_Id := Root_Type (T);
3585 -- If bad type, return 0
3587 if T = Any_Type then
3590 -- For generic types, just return zero. There cannot be any legitimate
3591 -- need to know such a size, but this routine may be called with a
3592 -- generic type as part of normal processing.
3594 elsif Is_Generic_Type (R_Typ)
3595 or else R_Typ = Any_Type
3599 -- Access types. Normally an access type cannot have a size smaller
3600 -- than the size of System.Address. The exception is on VMS, where
3601 -- we have short and long addresses, and it is possible for an access
3602 -- type to have a short address size (and thus be less than the size
3603 -- of System.Address itself). We simply skip the check for VMS, and
3604 -- leave it to the back end to do the check.
3606 elsif Is_Access_Type (T) then
3607 if OpenVMS_On_Target then
3610 return System_Address_Size;
3613 -- Floating-point types
3615 elsif Is_Floating_Point_Type (T) then
3616 return UI_To_Int (Esize (R_Typ));
3620 elsif Is_Discrete_Type (T) then
3622 -- The following loop is looking for the nearest compile time known
3623 -- bounds following the ancestor subtype chain. The idea is to find
3624 -- the most restrictive known bounds information.
3628 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3633 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
3634 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
3641 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
3642 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
3648 Ancest := Ancestor_Subtype (Ancest);
3651 Ancest := Base_Type (T);
3653 if Is_Generic_Type (Ancest) then
3659 -- Fixed-point types. We can't simply use Expr_Value to get the
3660 -- Corresponding_Integer_Value values of the bounds, since these do not
3661 -- get set till the type is frozen, and this routine can be called
3662 -- before the type is frozen. Similarly the test for bounds being static
3663 -- needs to include the case where we have unanalyzed real literals for
3666 elsif Is_Fixed_Point_Type (T) then
3668 -- The following loop is looking for the nearest compile time known
3669 -- bounds following the ancestor subtype chain. The idea is to find
3670 -- the most restrictive known bounds information.
3674 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3678 -- Note: In the following two tests for LoSet and HiSet, it may
3679 -- seem redundant to test for N_Real_Literal here since normally
3680 -- one would assume that the test for the value being known at
3681 -- compile time includes this case. However, there is a glitch.
3682 -- If the real literal comes from folding a non-static expression,
3683 -- then we don't consider any non- static expression to be known
3684 -- at compile time if we are in configurable run time mode (needed
3685 -- in some cases to give a clearer definition of what is and what
3686 -- is not accepted). So the test is indeed needed. Without it, we
3687 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
3690 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
3691 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
3693 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
3700 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
3701 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
3703 HiR := Expr_Value_R (Type_High_Bound (Ancest));
3709 Ancest := Ancestor_Subtype (Ancest);
3712 Ancest := Base_Type (T);
3714 if Is_Generic_Type (Ancest) then
3720 Lo := UR_To_Uint (LoR / Small_Value (T));
3721 Hi := UR_To_Uint (HiR / Small_Value (T));
3723 -- No other types allowed
3726 raise Program_Error;
3729 -- Fall through with Hi and Lo set. Deal with biased case
3732 and then not Is_Fixed_Point_Type (T)
3733 and then not (Is_Enumeration_Type (T)
3734 and then Has_Non_Standard_Rep (T)))
3735 or else Has_Biased_Representation (T)
3741 -- Signed case. Note that we consider types like range 1 .. -1 to be
3742 -- signed for the purpose of computing the size, since the bounds have
3743 -- to be accommodated in the base type.
3745 if Lo < 0 or else Hi < 0 then
3749 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
3750 -- Note that we accommodate the case where the bounds cross. This
3751 -- can happen either because of the way the bounds are declared
3752 -- or because of the algorithm in Freeze_Fixed_Point_Type.
3766 -- If both bounds are positive, make sure that both are represen-
3767 -- table in the case where the bounds are crossed. This can happen
3768 -- either because of the way the bounds are declared, or because of
3769 -- the algorithm in Freeze_Fixed_Point_Type.
3775 -- S = size, (can accommodate 0 .. (2**size - 1))
3778 while Hi >= Uint_2 ** S loop
3786 ---------------------------
3787 -- New_Stream_Subprogram --
3788 ---------------------------
3790 procedure New_Stream_Subprogram
3794 Nam : TSS_Name_Type)
3796 Loc : constant Source_Ptr := Sloc (N);
3797 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
3798 Subp_Id : Entity_Id;
3799 Subp_Decl : Node_Id;
3803 Defer_Declaration : constant Boolean :=
3804 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
3805 -- For a tagged type, there is a declaration for each stream attribute
3806 -- at the freeze point, and we must generate only a completion of this
3807 -- declaration. We do the same for private types, because the full view
3808 -- might be tagged. Otherwise we generate a declaration at the point of
3809 -- the attribute definition clause.
3811 function Build_Spec return Node_Id;
3812 -- Used for declaration and renaming declaration, so that this is
3813 -- treated as a renaming_as_body.
3819 function Build_Spec return Node_Id is
3820 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
3823 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
3826 Subp_Id := Make_Defining_Identifier (Loc, Sname);
3828 -- S : access Root_Stream_Type'Class
3830 Formals := New_List (
3831 Make_Parameter_Specification (Loc,
3832 Defining_Identifier =>
3833 Make_Defining_Identifier (Loc, Name_S),
3835 Make_Access_Definition (Loc,
3838 Designated_Type (Etype (F)), Loc))));
3840 if Nam = TSS_Stream_Input then
3841 Spec := Make_Function_Specification (Loc,
3842 Defining_Unit_Name => Subp_Id,
3843 Parameter_Specifications => Formals,
3844 Result_Definition => T_Ref);
3849 Make_Parameter_Specification (Loc,
3850 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
3851 Out_Present => Out_P,
3852 Parameter_Type => T_Ref));
3854 Spec := Make_Procedure_Specification (Loc,
3855 Defining_Unit_Name => Subp_Id,
3856 Parameter_Specifications => Formals);
3862 -- Start of processing for New_Stream_Subprogram
3865 F := First_Formal (Subp);
3867 if Ekind (Subp) = E_Procedure then
3868 Etyp := Etype (Next_Formal (F));
3870 Etyp := Etype (Subp);
3873 -- Prepare subprogram declaration and insert it as an action on the
3874 -- clause node. The visibility for this entity is used to test for
3875 -- visibility of the attribute definition clause (in the sense of
3876 -- 8.3(23) as amended by AI-195).
3878 if not Defer_Declaration then
3880 Make_Subprogram_Declaration (Loc,
3881 Specification => Build_Spec);
3883 -- For a tagged type, there is always a visible declaration for each
3884 -- stream TSS (it is a predefined primitive operation), and the
3885 -- completion of this declaration occurs at the freeze point, which is
3886 -- not always visible at places where the attribute definition clause is
3887 -- visible. So, we create a dummy entity here for the purpose of
3888 -- tracking the visibility of the attribute definition clause itself.
3892 Make_Defining_Identifier (Loc,
3893 Chars => New_External_Name (Sname, 'V'));
3895 Make_Object_Declaration (Loc,
3896 Defining_Identifier => Subp_Id,
3897 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
3900 Insert_Action (N, Subp_Decl);
3901 Set_Entity (N, Subp_Id);
3904 Make_Subprogram_Renaming_Declaration (Loc,
3905 Specification => Build_Spec,
3906 Name => New_Reference_To (Subp, Loc));
3908 if Defer_Declaration then
3909 Set_TSS (Base_Type (Ent), Subp_Id);
3911 Insert_Action (N, Subp_Decl);
3912 Copy_TSS (Subp_Id, Base_Type (Ent));
3914 end New_Stream_Subprogram;
3916 ------------------------
3917 -- Rep_Item_Too_Early --
3918 ------------------------
3920 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
3922 -- Cannot apply non-operational rep items to generic types
3924 if Is_Operational_Item (N) then
3928 and then Is_Generic_Type (Root_Type (T))
3931 ("representation item not allowed for generic type", N);
3935 -- Otherwise check for incomplete type
3937 if Is_Incomplete_Or_Private_Type (T)
3938 and then No (Underlying_Type (T))
3941 ("representation item must be after full type declaration", N);
3944 -- If the type has incomplete components, a representation clause is
3945 -- illegal but stream attributes and Convention pragmas are correct.
3947 elsif Has_Private_Component (T) then
3948 if Nkind (N) = N_Pragma then
3952 ("representation item must appear after type is fully defined",
3959 end Rep_Item_Too_Early;
3961 -----------------------
3962 -- Rep_Item_Too_Late --
3963 -----------------------
3965 function Rep_Item_Too_Late
3968 FOnly : Boolean := False) return Boolean
3971 Parent_Type : Entity_Id;
3974 -- Output the too late message. Note that this is not considered a
3975 -- serious error, since the effect is simply that we ignore the
3976 -- representation clause in this case.
3982 procedure Too_Late is
3984 Error_Msg_N ("|representation item appears too late!", N);
3987 -- Start of processing for Rep_Item_Too_Late
3990 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
3991 -- types, which may be frozen if they appear in a representation clause
3992 -- for a local type.
3995 and then not From_With_Type (T)
3998 S := First_Subtype (T);
4000 if Present (Freeze_Node (S)) then
4002 ("?no more representation items for }", Freeze_Node (S), S);
4007 -- Check for case of non-tagged derived type whose parent either has
4008 -- primitive operations, or is a by reference type (RM 13.1(10)).
4012 and then Is_Derived_Type (T)
4013 and then not Is_Tagged_Type (T)
4015 Parent_Type := Etype (Base_Type (T));
4017 if Has_Primitive_Operations (Parent_Type) then
4020 ("primitive operations already defined for&!", N, Parent_Type);
4023 elsif Is_By_Reference_Type (Parent_Type) then
4026 ("parent type & is a by reference type!", N, Parent_Type);
4031 -- No error, link item into head of chain of rep items for the entity,
4032 -- but avoid chaining if we have an overloadable entity, and the pragma
4033 -- is one that can apply to multiple overloaded entities.
4035 if Is_Overloadable (T)
4036 and then Nkind (N) = N_Pragma
4039 Pname : constant Name_Id := Pragma_Name (N);
4041 if Pname = Name_Convention or else
4042 Pname = Name_Import or else
4043 Pname = Name_Export or else
4044 Pname = Name_External or else
4045 Pname = Name_Interface
4052 Record_Rep_Item (T, N);
4054 end Rep_Item_Too_Late;
4056 -------------------------
4057 -- Same_Representation --
4058 -------------------------
4060 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
4061 T1 : constant Entity_Id := Underlying_Type (Typ1);
4062 T2 : constant Entity_Id := Underlying_Type (Typ2);
4065 -- A quick check, if base types are the same, then we definitely have
4066 -- the same representation, because the subtype specific representation
4067 -- attributes (Size and Alignment) do not affect representation from
4068 -- the point of view of this test.
4070 if Base_Type (T1) = Base_Type (T2) then
4073 elsif Is_Private_Type (Base_Type (T2))
4074 and then Base_Type (T1) = Full_View (Base_Type (T2))
4079 -- Tagged types never have differing representations
4081 if Is_Tagged_Type (T1) then
4085 -- Representations are definitely different if conventions differ
4087 if Convention (T1) /= Convention (T2) then
4091 -- Representations are different if component alignments differ
4093 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4095 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4096 and then Component_Alignment (T1) /= Component_Alignment (T2)
4101 -- For arrays, the only real issue is component size. If we know the
4102 -- component size for both arrays, and it is the same, then that's
4103 -- good enough to know we don't have a change of representation.
4105 if Is_Array_Type (T1) then
4106 if Known_Component_Size (T1)
4107 and then Known_Component_Size (T2)
4108 and then Component_Size (T1) = Component_Size (T2)
4114 -- Types definitely have same representation if neither has non-standard
4115 -- representation since default representations are always consistent.
4116 -- If only one has non-standard representation, and the other does not,
4117 -- then we consider that they do not have the same representation. They
4118 -- might, but there is no way of telling early enough.
4120 if Has_Non_Standard_Rep (T1) then
4121 if not Has_Non_Standard_Rep (T2) then
4125 return not Has_Non_Standard_Rep (T2);
4128 -- Here the two types both have non-standard representation, and we need
4129 -- to determine if they have the same non-standard representation.
4131 -- For arrays, we simply need to test if the component sizes are the
4132 -- same. Pragma Pack is reflected in modified component sizes, so this
4133 -- check also deals with pragma Pack.
4135 if Is_Array_Type (T1) then
4136 return Component_Size (T1) = Component_Size (T2);
4138 -- Tagged types always have the same representation, because it is not
4139 -- possible to specify different representations for common fields.
4141 elsif Is_Tagged_Type (T1) then
4144 -- Case of record types
4146 elsif Is_Record_Type (T1) then
4148 -- Packed status must conform
4150 if Is_Packed (T1) /= Is_Packed (T2) then
4153 -- Otherwise we must check components. Typ2 maybe a constrained
4154 -- subtype with fewer components, so we compare the components
4155 -- of the base types.
4158 Record_Case : declare
4159 CD1, CD2 : Entity_Id;
4161 function Same_Rep return Boolean;
4162 -- CD1 and CD2 are either components or discriminants. This
4163 -- function tests whether the two have the same representation
4169 function Same_Rep return Boolean is
4171 if No (Component_Clause (CD1)) then
4172 return No (Component_Clause (CD2));
4176 Present (Component_Clause (CD2))
4178 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4180 Esize (CD1) = Esize (CD2);
4184 -- Start of processing for Record_Case
4187 if Has_Discriminants (T1) then
4188 CD1 := First_Discriminant (T1);
4189 CD2 := First_Discriminant (T2);
4191 -- The number of discriminants may be different if the
4192 -- derived type has fewer (constrained by values). The
4193 -- invisible discriminants retain the representation of
4194 -- the original, so the discrepancy does not per se
4195 -- indicate a different representation.
4198 and then Present (CD2)
4200 if not Same_Rep then
4203 Next_Discriminant (CD1);
4204 Next_Discriminant (CD2);
4209 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4210 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4212 while Present (CD1) loop
4213 if not Same_Rep then
4216 Next_Component (CD1);
4217 Next_Component (CD2);
4225 -- For enumeration types, we must check each literal to see if the
4226 -- representation is the same. Note that we do not permit enumeration
4227 -- representation clauses for Character and Wide_Character, so these
4228 -- cases were already dealt with.
4230 elsif Is_Enumeration_Type (T1) then
4232 Enumeration_Case : declare
4236 L1 := First_Literal (T1);
4237 L2 := First_Literal (T2);
4239 while Present (L1) loop
4240 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4250 end Enumeration_Case;
4252 -- Any other types have the same representation for these purposes
4257 end Same_Representation;
4259 --------------------
4260 -- Set_Enum_Esize --
4261 --------------------
4263 procedure Set_Enum_Esize (T : Entity_Id) is
4271 -- Find the minimum standard size (8,16,32,64) that fits
4273 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4274 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4277 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4278 Sz := Standard_Character_Size; -- May be > 8 on some targets
4280 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4283 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4286 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4291 if Hi < Uint_2**08 then
4292 Sz := Standard_Character_Size; -- May be > 8 on some targets
4294 elsif Hi < Uint_2**16 then
4297 elsif Hi < Uint_2**32 then
4300 else pragma Assert (Hi < Uint_2**63);
4305 -- That minimum is the proper size unless we have a foreign convention
4306 -- and the size required is 32 or less, in which case we bump the size
4307 -- up to 32. This is required for C and C++ and seems reasonable for
4308 -- all other foreign conventions.
4310 if Has_Foreign_Convention (T)
4311 and then Esize (T) < Standard_Integer_Size
4313 Init_Esize (T, Standard_Integer_Size);
4319 ------------------------------
4320 -- Validate_Address_Clauses --
4321 ------------------------------
4323 procedure Validate_Address_Clauses is
4325 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4327 ACCR : Address_Clause_Check_Record
4328 renames Address_Clause_Checks.Table (J);
4339 -- Skip processing of this entry if warning already posted
4341 if not Address_Warning_Posted (ACCR.N) then
4343 Expr := Original_Node (Expression (ACCR.N));
4347 X_Alignment := Alignment (ACCR.X);
4348 Y_Alignment := Alignment (ACCR.Y);
4350 -- Similarly obtain sizes
4352 X_Size := Esize (ACCR.X);
4353 Y_Size := Esize (ACCR.Y);
4355 -- Check for large object overlaying smaller one
4358 and then X_Size > Uint_0
4359 and then X_Size > Y_Size
4362 ("?& overlays smaller object", ACCR.N, ACCR.X);
4364 ("\?program execution may be erroneous", ACCR.N);
4365 Error_Msg_Uint_1 := X_Size;
4367 ("\?size of & is ^", ACCR.N, ACCR.X);
4368 Error_Msg_Uint_1 := Y_Size;
4370 ("\?size of & is ^", ACCR.N, ACCR.Y);
4372 -- Check for inadequate alignment, both of the base object
4373 -- and of the offset, if any.
4375 -- Note: we do not check the alignment if we gave a size
4376 -- warning, since it would likely be redundant.
4378 elsif Y_Alignment /= Uint_0
4379 and then (Y_Alignment < X_Alignment
4382 Nkind (Expr) = N_Attribute_Reference
4384 Attribute_Name (Expr) = Name_Address
4386 Has_Compatible_Alignment
4387 (ACCR.X, Prefix (Expr))
4388 /= Known_Compatible))
4391 ("?specified address for& may be inconsistent "
4395 ("\?program execution may be erroneous (RM 13.3(27))",
4397 Error_Msg_Uint_1 := X_Alignment;
4399 ("\?alignment of & is ^",
4401 Error_Msg_Uint_1 := Y_Alignment;
4403 ("\?alignment of & is ^",
4405 if Y_Alignment >= X_Alignment then
4407 ("\?but offset is not multiple of alignment",
4414 end Validate_Address_Clauses;
4416 -----------------------------------
4417 -- Validate_Unchecked_Conversion --
4418 -----------------------------------
4420 procedure Validate_Unchecked_Conversion
4422 Act_Unit : Entity_Id)
4429 -- Obtain source and target types. Note that we call Ancestor_Subtype
4430 -- here because the processing for generic instantiation always makes
4431 -- subtypes, and we want the original frozen actual types.
4433 -- If we are dealing with private types, then do the check on their
4434 -- fully declared counterparts if the full declarations have been
4435 -- encountered (they don't have to be visible, but they must exist!)
4437 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
4439 if Is_Private_Type (Source)
4440 and then Present (Underlying_Type (Source))
4442 Source := Underlying_Type (Source);
4445 Target := Ancestor_Subtype (Etype (Act_Unit));
4447 -- If either type is generic, the instantiation happens within a generic
4448 -- unit, and there is nothing to check. The proper check
4449 -- will happen when the enclosing generic is instantiated.
4451 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
4455 if Is_Private_Type (Target)
4456 and then Present (Underlying_Type (Target))
4458 Target := Underlying_Type (Target);
4461 -- Source may be unconstrained array, but not target
4463 if Is_Array_Type (Target)
4464 and then not Is_Constrained (Target)
4467 ("unchecked conversion to unconstrained array not allowed", N);
4471 -- Warn if conversion between two different convention pointers
4473 if Is_Access_Type (Target)
4474 and then Is_Access_Type (Source)
4475 and then Convention (Target) /= Convention (Source)
4476 and then Warn_On_Unchecked_Conversion
4478 -- Give warnings for subprogram pointers only on most targets. The
4479 -- exception is VMS, where data pointers can have different lengths
4480 -- depending on the pointer convention.
4482 if Is_Access_Subprogram_Type (Target)
4483 or else Is_Access_Subprogram_Type (Source)
4484 or else OpenVMS_On_Target
4487 ("?conversion between pointers with different conventions!", N);
4491 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4492 -- warning when compiling GNAT-related sources.
4494 if Warn_On_Unchecked_Conversion
4495 and then not In_Predefined_Unit (N)
4496 and then RTU_Loaded (Ada_Calendar)
4498 (Chars (Source) = Name_Time
4500 Chars (Target) = Name_Time)
4502 -- If Ada.Calendar is loaded and the name of one of the operands is
4503 -- Time, there is a good chance that this is Ada.Calendar.Time.
4506 Calendar_Time : constant Entity_Id :=
4507 Full_View (RTE (RO_CA_Time));
4509 pragma Assert (Present (Calendar_Time));
4511 if Source = Calendar_Time
4512 or else Target = Calendar_Time
4515 ("?representation of 'Time values may change between " &
4516 "'G'N'A'T versions", N);
4521 -- Make entry in unchecked conversion table for later processing by
4522 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4523 -- (using values set by the back-end where possible). This is only done
4524 -- if the appropriate warning is active.
4526 if Warn_On_Unchecked_Conversion then
4527 Unchecked_Conversions.Append
4528 (New_Val => UC_Entry'
4533 -- If both sizes are known statically now, then back end annotation
4534 -- is not required to do a proper check but if either size is not
4535 -- known statically, then we need the annotation.
4537 if Known_Static_RM_Size (Source)
4538 and then Known_Static_RM_Size (Target)
4542 Back_Annotate_Rep_Info := True;
4546 -- If unchecked conversion to access type, and access type is declared
4547 -- in the same unit as the unchecked conversion, then set the
4548 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4551 if Is_Access_Type (Target) and then
4552 In_Same_Source_Unit (Target, N)
4554 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4557 -- Generate N_Validate_Unchecked_Conversion node for back end in
4558 -- case the back end needs to perform special validation checks.
4560 -- Shouldn't this be in Exp_Ch13, since the check only gets done
4561 -- if we have full expansion and the back end is called ???
4564 Make_Validate_Unchecked_Conversion (Sloc (N));
4565 Set_Source_Type (Vnode, Source);
4566 Set_Target_Type (Vnode, Target);
4568 -- If the unchecked conversion node is in a list, just insert before it.
4569 -- If not we have some strange case, not worth bothering about.
4571 if Is_List_Member (N) then
4572 Insert_After (N, Vnode);
4574 end Validate_Unchecked_Conversion;
4576 ------------------------------------
4577 -- Validate_Unchecked_Conversions --
4578 ------------------------------------
4580 procedure Validate_Unchecked_Conversions is
4582 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4584 T : UC_Entry renames Unchecked_Conversions.Table (N);
4586 Eloc : constant Source_Ptr := T.Eloc;
4587 Source : constant Entity_Id := T.Source;
4588 Target : constant Entity_Id := T.Target;
4594 -- This validation check, which warns if we have unequal sizes for
4595 -- unchecked conversion, and thus potentially implementation
4596 -- dependent semantics, is one of the few occasions on which we
4597 -- use the official RM size instead of Esize. See description in
4598 -- Einfo "Handling of Type'Size Values" for details.
4600 if Serious_Errors_Detected = 0
4601 and then Known_Static_RM_Size (Source)
4602 and then Known_Static_RM_Size (Target)
4604 -- Don't do the check if warnings off for either type, note the
4605 -- deliberate use of OR here instead of OR ELSE to get the flag
4606 -- Warnings_Off_Used set for both types if appropriate.
4608 and then not (Has_Warnings_Off (Source)
4610 Has_Warnings_Off (Target))
4612 Source_Siz := RM_Size (Source);
4613 Target_Siz := RM_Size (Target);
4615 if Source_Siz /= Target_Siz then
4617 ("?types for unchecked conversion have different sizes!",
4620 if All_Errors_Mode then
4621 Error_Msg_Name_1 := Chars (Source);
4622 Error_Msg_Uint_1 := Source_Siz;
4623 Error_Msg_Name_2 := Chars (Target);
4624 Error_Msg_Uint_2 := Target_Siz;
4625 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
4627 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4629 if Is_Discrete_Type (Source)
4630 and then Is_Discrete_Type (Target)
4632 if Source_Siz > Target_Siz then
4634 ("\?^ high order bits of source will be ignored!",
4637 elsif Is_Unsigned_Type (Source) then
4639 ("\?source will be extended with ^ high order " &
4640 "zero bits?!", Eloc);
4644 ("\?source will be extended with ^ high order " &
4649 elsif Source_Siz < Target_Siz then
4650 if Is_Discrete_Type (Target) then
4651 if Bytes_Big_Endian then
4653 ("\?target value will include ^ undefined " &
4658 ("\?target value will include ^ undefined " &
4665 ("\?^ trailing bits of target value will be " &
4666 "undefined!", Eloc);
4669 else pragma Assert (Source_Siz > Target_Siz);
4671 ("\?^ trailing bits of source will be ignored!",
4678 -- If both types are access types, we need to check the alignment.
4679 -- If the alignment of both is specified, we can do it here.
4681 if Serious_Errors_Detected = 0
4682 and then Ekind (Source) in Access_Kind
4683 and then Ekind (Target) in Access_Kind
4684 and then Target_Strict_Alignment
4685 and then Present (Designated_Type (Source))
4686 and then Present (Designated_Type (Target))
4689 D_Source : constant Entity_Id := Designated_Type (Source);
4690 D_Target : constant Entity_Id := Designated_Type (Target);
4693 if Known_Alignment (D_Source)
4694 and then Known_Alignment (D_Target)
4697 Source_Align : constant Uint := Alignment (D_Source);
4698 Target_Align : constant Uint := Alignment (D_Target);
4701 if Source_Align < Target_Align
4702 and then not Is_Tagged_Type (D_Source)
4704 -- Suppress warning if warnings suppressed on either
4705 -- type or either designated type. Note the use of
4706 -- OR here instead of OR ELSE. That is intentional,
4707 -- we would like to set flag Warnings_Off_Used in
4708 -- all types for which warnings are suppressed.
4710 and then not (Has_Warnings_Off (D_Source)
4712 Has_Warnings_Off (D_Target)
4714 Has_Warnings_Off (Source)
4716 Has_Warnings_Off (Target))
4718 Error_Msg_Uint_1 := Target_Align;
4719 Error_Msg_Uint_2 := Source_Align;
4720 Error_Msg_Node_1 := D_Target;
4721 Error_Msg_Node_2 := D_Source;
4723 ("?alignment of & (^) is stricter than " &
4724 "alignment of & (^)!", Eloc);
4726 ("\?resulting access value may have invalid " &
4727 "alignment!", Eloc);
4735 end Validate_Unchecked_Conversions;