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_Ch3; use Sem_Ch3;
44 with Sem_Ch8; use Sem_Ch8;
45 with Sem_Eval; use Sem_Eval;
46 with Sem_Res; use Sem_Res;
47 with Sem_Type; use Sem_Type;
48 with Sem_Util; use Sem_Util;
49 with Sem_Warn; use Sem_Warn;
50 with Snames; use Snames;
51 with Stand; use Stand;
52 with Sinfo; use Sinfo;
54 with Targparm; use Targparm;
55 with Ttypes; use Ttypes;
56 with Tbuild; use Tbuild;
57 with Urealp; use Urealp;
59 with GNAT.Heap_Sort_G;
61 package body Sem_Ch13 is
63 SSU : constant Pos := System_Storage_Unit;
64 -- Convenient short hand for commonly used constant
66 -----------------------
67 -- Local Subprograms --
68 -----------------------
70 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
71 -- This routine is called after setting the Esize of type entity Typ.
72 -- The purpose is to deal with the situation where an alignment has been
73 -- inherited from a derived type that is no longer appropriate for the
74 -- new Esize value. In this case, we reset the Alignment to unknown.
76 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
77 -- Given two entities for record components or discriminants, checks
78 -- if they have overlapping component clauses and issues errors if so.
80 function Get_Alignment_Value (Expr : Node_Id) return Uint;
81 -- Given the expression for an alignment value, returns the corresponding
82 -- Uint value. If the value is inappropriate, then error messages are
83 -- posted as required, and a value of No_Uint is returned.
85 function Is_Operational_Item (N : Node_Id) return Boolean;
86 -- A specification for a stream attribute is allowed before the full
87 -- type is declared, as explained in AI-00137 and the corrigendum.
88 -- Attributes that do not specify a representation characteristic are
89 -- operational attributes.
91 procedure New_Stream_Subprogram
96 -- Create a subprogram renaming of a given stream attribute to the
97 -- designated subprogram and then in the tagged case, provide this as a
98 -- primitive operation, or in the non-tagged case make an appropriate TSS
99 -- entry. This is more properly an expansion activity than just semantics,
100 -- but the presence of user-defined stream functions for limited types is a
101 -- legality check, which is why this takes place here rather than in
102 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
103 -- function to be generated.
105 -- To avoid elaboration anomalies with freeze nodes, for untagged types
106 -- we generate both a subprogram declaration and a subprogram renaming
107 -- declaration, so that the attribute specification is handled as a
108 -- renaming_as_body. For tagged types, the specification is one of the
111 ----------------------------------------------
112 -- Table for Validate_Unchecked_Conversions --
113 ----------------------------------------------
115 -- The following table collects unchecked conversions for validation.
116 -- Entries are made by Validate_Unchecked_Conversion and then the
117 -- call to Validate_Unchecked_Conversions does the actual error
118 -- checking and posting of warnings. The reason for this delayed
119 -- processing is to take advantage of back-annotations of size and
120 -- alignment values performed by the back end.
122 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
123 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
124 -- will already have modified all Sloc values if the -gnatD option is set.
126 type UC_Entry is record
127 Eloc : Source_Ptr; -- node used for posting warnings
128 Source : Entity_Id; -- source type for unchecked conversion
129 Target : Entity_Id; -- target type for unchecked conversion
132 package Unchecked_Conversions is new Table.Table (
133 Table_Component_Type => UC_Entry,
134 Table_Index_Type => Int,
135 Table_Low_Bound => 1,
137 Table_Increment => 200,
138 Table_Name => "Unchecked_Conversions");
140 ----------------------------------------
141 -- Table for Validate_Address_Clauses --
142 ----------------------------------------
144 -- If an address clause has the form
146 -- for X'Address use Expr
148 -- where Expr is of the form Y'Address or recursively is a reference
149 -- to a constant of either of these forms, and X and Y are entities of
150 -- objects, then if Y has a smaller alignment than X, that merits a
151 -- warning about possible bad alignment. The following table collects
152 -- address clauses of this kind. We put these in a table so that they
153 -- can be checked after the back end has completed annotation of the
154 -- alignments of objects, since we can catch more cases that way.
156 type Address_Clause_Check_Record is record
158 -- The address clause
161 -- The entity of the object overlaying Y
164 -- The entity of the object being overlaid
167 -- Whether the address is offseted within Y
170 package Address_Clause_Checks is new Table.Table (
171 Table_Component_Type => Address_Clause_Check_Record,
172 Table_Index_Type => Int,
173 Table_Low_Bound => 1,
175 Table_Increment => 200,
176 Table_Name => "Address_Clause_Checks");
178 -----------------------------------------
179 -- Adjust_Record_For_Reverse_Bit_Order --
180 -----------------------------------------
182 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
183 Max_Machine_Scalar_Size : constant Uint :=
185 (Standard_Long_Long_Integer_Size);
186 -- We use this as the maximum machine scalar size in the sense of AI-133
190 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
193 -- This first loop through components does two things. First it deals
194 -- with the case of components with component clauses whose length is
195 -- greater than the maximum machine scalar size (either accepting them
196 -- or rejecting as needed). Second, it counts the number of components
197 -- with component clauses whose length does not exceed this maximum for
201 Comp := First_Component_Or_Discriminant (R);
202 while Present (Comp) loop
204 CC : constant Node_Id := Component_Clause (Comp);
209 Fbit : constant Uint := Static_Integer (First_Bit (CC));
212 -- Case of component with size > max machine scalar
214 if Esize (Comp) > Max_Machine_Scalar_Size then
216 -- Must begin on byte boundary
218 if Fbit mod SSU /= 0 then
220 ("illegal first bit value for reverse bit order",
222 Error_Msg_Uint_1 := SSU;
223 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
226 ("\must be a multiple of ^ if size greater than ^",
229 -- Must end on byte boundary
231 elsif Esize (Comp) mod SSU /= 0 then
233 ("illegal last bit value for reverse bit order",
235 Error_Msg_Uint_1 := SSU;
236 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
239 ("\must be a multiple of ^ if size greater than ^",
242 -- OK, give warning if enabled
244 elsif Warn_On_Reverse_Bit_Order then
246 ("multi-byte field specified with non-standard"
247 & " Bit_Order?", CC);
249 if Bytes_Big_Endian then
251 ("\bytes are not reversed "
252 & "(component is big-endian)?", CC);
255 ("\bytes are not reversed "
256 & "(component is little-endian)?", CC);
260 -- Case where size is not greater than max machine
261 -- scalar. For now, we just count these.
264 Num_CC := Num_CC + 1;
270 Next_Component_Or_Discriminant (Comp);
273 -- We need to sort the component clauses on the basis of the Position
274 -- values in the clause, so we can group clauses with the same Position.
275 -- together to determine the relevant machine scalar size.
278 Comps : array (0 .. Num_CC) of Entity_Id;
279 -- Array to collect component and discriminant entities. The data
280 -- starts at index 1, the 0'th entry is for the sort routine.
282 function CP_Lt (Op1, Op2 : Natural) return Boolean;
283 -- Compare routine for Sort
285 procedure CP_Move (From : Natural; To : Natural);
286 -- Move routine for Sort
288 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
292 -- Start and stop positions in component list of set of components
293 -- with the same starting position (that constitute components in
294 -- a single machine scalar).
297 -- Maximum last bit value of any component in this set
300 -- Corresponding machine scalar size
306 function CP_Lt (Op1, Op2 : Natural) return Boolean is
308 return Position (Component_Clause (Comps (Op1))) <
309 Position (Component_Clause (Comps (Op2)));
316 procedure CP_Move (From : Natural; To : Natural) is
318 Comps (To) := Comps (From);
322 -- Collect the component clauses
325 Comp := First_Component_Or_Discriminant (R);
326 while Present (Comp) loop
327 if Present (Component_Clause (Comp))
328 and then Esize (Comp) <= Max_Machine_Scalar_Size
330 Num_CC := Num_CC + 1;
331 Comps (Num_CC) := Comp;
334 Next_Component_Or_Discriminant (Comp);
337 -- Sort by ascending position number
339 Sorting.Sort (Num_CC);
341 -- We now have all the components whose size does not exceed the max
342 -- machine scalar value, sorted by starting position. In this loop
343 -- we gather groups of clauses starting at the same position, to
344 -- process them in accordance with Ada 2005 AI-133.
347 while Stop < Num_CC loop
351 Static_Integer (Last_Bit (Component_Clause (Comps (Start))));
352 while Stop < Num_CC loop
354 (Position (Component_Clause (Comps (Stop + 1)))) =
356 (Position (Component_Clause (Comps (Stop))))
363 (Last_Bit (Component_Clause (Comps (Stop)))));
369 -- Now we have a group of component clauses from Start to Stop
370 -- whose positions are identical, and MaxL is the maximum last bit
371 -- value of any of these components.
373 -- We need to determine the corresponding machine scalar size.
374 -- This loop assumes that machine scalar sizes are even, and that
375 -- each possible machine scalar has twice as many bits as the
378 MSS := Max_Machine_Scalar_Size;
380 and then (MSS / 2) >= SSU
381 and then (MSS / 2) > MaxL
386 -- Here is where we fix up the Component_Bit_Offset value to
387 -- account for the reverse bit order. Some examples of what needs
388 -- to be done for the case of a machine scalar size of 8 are:
390 -- First_Bit .. Last_Bit Component_Bit_Offset
402 -- The general rule is that the first bit is obtained by
403 -- subtracting the old ending bit from machine scalar size - 1.
405 for C in Start .. Stop loop
407 Comp : constant Entity_Id := Comps (C);
408 CC : constant Node_Id := Component_Clause (Comp);
409 LB : constant Uint := Static_Integer (Last_Bit (CC));
410 NFB : constant Uint := MSS - Uint_1 - LB;
411 NLB : constant Uint := NFB + Esize (Comp) - 1;
412 Pos : constant Uint := Static_Integer (Position (CC));
415 if Warn_On_Reverse_Bit_Order then
416 Error_Msg_Uint_1 := MSS;
418 ("info: reverse bit order in machine " &
419 "scalar of length^?", First_Bit (CC));
420 Error_Msg_Uint_1 := NFB;
421 Error_Msg_Uint_2 := NLB;
423 if Bytes_Big_Endian then
425 ("?\info: big-endian range for "
426 & "component & is ^ .. ^",
427 First_Bit (CC), Comp);
430 ("?\info: little-endian range "
431 & "for component & is ^ .. ^",
432 First_Bit (CC), Comp);
436 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
437 Set_Normalized_First_Bit (Comp, NFB mod SSU);
442 end Adjust_Record_For_Reverse_Bit_Order;
444 --------------------------------------
445 -- Alignment_Check_For_Esize_Change --
446 --------------------------------------
448 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
450 -- If the alignment is known, and not set by a rep clause, and is
451 -- inconsistent with the size being set, then reset it to unknown,
452 -- we assume in this case that the size overrides the inherited
453 -- alignment, and that the alignment must be recomputed.
455 if Known_Alignment (Typ)
456 and then not Has_Alignment_Clause (Typ)
457 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
459 Init_Alignment (Typ);
461 end Alignment_Check_For_Esize_Change;
463 -----------------------
464 -- Analyze_At_Clause --
465 -----------------------
467 -- An at clause is replaced by the corresponding Address attribute
468 -- definition clause that is the preferred approach in Ada 95.
470 procedure Analyze_At_Clause (N : Node_Id) is
471 CS : constant Boolean := Comes_From_Source (N);
474 -- This is an obsolescent feature
476 Check_Restriction (No_Obsolescent_Features, N);
478 if Warn_On_Obsolescent_Feature then
480 ("at clause is an obsolescent feature (RM J.7(2))?", N);
482 ("\use address attribute definition clause instead?", N);
485 -- Rewrite as address clause
488 Make_Attribute_Definition_Clause (Sloc (N),
489 Name => Identifier (N),
490 Chars => Name_Address,
491 Expression => Expression (N)));
493 -- We preserve Comes_From_Source, since logically the clause still
494 -- comes from the source program even though it is changed in form.
496 Set_Comes_From_Source (N, CS);
498 -- Analyze rewritten clause
500 Analyze_Attribute_Definition_Clause (N);
501 end Analyze_At_Clause;
503 -----------------------------------------
504 -- Analyze_Attribute_Definition_Clause --
505 -----------------------------------------
507 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
508 Loc : constant Source_Ptr := Sloc (N);
509 Nam : constant Node_Id := Name (N);
510 Attr : constant Name_Id := Chars (N);
511 Expr : constant Node_Id := Expression (N);
512 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
516 FOnly : Boolean := False;
517 -- Reset to True for subtype specific attribute (Alignment, Size)
518 -- and for stream attributes, i.e. those cases where in the call
519 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
520 -- rules are checked. Note that the case of stream attributes is not
521 -- clear from the RM, but see AI95-00137. Also, the RM seems to
522 -- disallow Storage_Size for derived task types, but that is also
523 -- clearly unintentional.
525 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
526 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
527 -- definition clauses.
529 -----------------------------------
530 -- Analyze_Stream_TSS_Definition --
531 -----------------------------------
533 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
534 Subp : Entity_Id := Empty;
539 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
541 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
542 -- Return true if the entity is a subprogram with an appropriate
543 -- profile for the attribute being defined.
545 ----------------------
546 -- Has_Good_Profile --
547 ----------------------
549 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
551 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
552 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
553 (False => E_Procedure, True => E_Function);
557 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
561 F := First_Formal (Subp);
564 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
565 or else Designated_Type (Etype (F)) /=
566 Class_Wide_Type (RTE (RE_Root_Stream_Type))
571 if not Is_Function then
575 Expected_Mode : constant array (Boolean) of Entity_Kind :=
576 (False => E_In_Parameter,
577 True => E_Out_Parameter);
579 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
590 return Base_Type (Typ) = Base_Type (Ent)
591 and then No (Next_Formal (F));
592 end Has_Good_Profile;
594 -- Start of processing for Analyze_Stream_TSS_Definition
599 if not Is_Type (U_Ent) then
600 Error_Msg_N ("local name must be a subtype", Nam);
604 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
606 -- If Pnam is present, it can be either inherited from an ancestor
607 -- type (in which case it is legal to redefine it for this type), or
608 -- be a previous definition of the attribute for the same type (in
609 -- which case it is illegal).
611 -- In the first case, it will have been analyzed already, and we
612 -- can check that its profile does not match the expected profile
613 -- for a stream attribute of U_Ent. In the second case, either Pnam
614 -- has been analyzed (and has the expected profile), or it has not
615 -- been analyzed yet (case of a type that has not been frozen yet
616 -- and for which the stream attribute has been set using Set_TSS).
619 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
621 Error_Msg_Sloc := Sloc (Pnam);
622 Error_Msg_Name_1 := Attr;
623 Error_Msg_N ("% attribute already defined #", Nam);
629 if Is_Entity_Name (Expr) then
630 if not Is_Overloaded (Expr) then
631 if Has_Good_Profile (Entity (Expr)) then
632 Subp := Entity (Expr);
636 Get_First_Interp (Expr, I, It);
637 while Present (It.Nam) loop
638 if Has_Good_Profile (It.Nam) then
643 Get_Next_Interp (I, It);
648 if Present (Subp) then
649 if Is_Abstract_Subprogram (Subp) then
650 Error_Msg_N ("stream subprogram must not be abstract", Expr);
654 Set_Entity (Expr, Subp);
655 Set_Etype (Expr, Etype (Subp));
657 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
660 Error_Msg_Name_1 := Attr;
661 Error_Msg_N ("incorrect expression for% attribute", Expr);
663 end Analyze_Stream_TSS_Definition;
665 -- Start of processing for Analyze_Attribute_Definition_Clause
668 -- Process Ignore_Rep_Clauses option
670 if Ignore_Rep_Clauses then
673 -- The following should be ignored. They do not affect legality
674 -- and may be target dependent. The basic idea of -gnatI is to
675 -- ignore any rep clauses that may be target dependent but do not
676 -- affect legality (except possibly to be rejected because they
677 -- are incompatible with the compilation target).
679 when Attribute_Alignment |
680 Attribute_Bit_Order |
681 Attribute_Component_Size |
682 Attribute_Machine_Radix |
683 Attribute_Object_Size |
686 Attribute_Stream_Size |
687 Attribute_Value_Size =>
689 Rewrite (N, Make_Null_Statement (Sloc (N)));
692 -- The following should not be ignored, because in the first place
693 -- they are reasonably portable, and should not cause problems in
694 -- compiling code from another target, and also they do affect
695 -- legality, e.g. failing to provide a stream attribute for a
696 -- type may make a program illegal.
698 when Attribute_External_Tag |
702 Attribute_Storage_Pool |
703 Attribute_Storage_Size |
707 -- Other cases are errors, which will be caught below
717 if Rep_Item_Too_Early (Ent, N) then
721 -- Rep clause applies to full view of incomplete type or private type if
722 -- we have one (if not, this is a premature use of the type). However,
723 -- certain semantic checks need to be done on the specified entity (i.e.
724 -- the private view), so we save it in Ent.
726 if Is_Private_Type (Ent)
727 and then Is_Derived_Type (Ent)
728 and then not Is_Tagged_Type (Ent)
729 and then No (Full_View (Ent))
731 -- If this is a private type whose completion is a derivation from
732 -- another private type, there is no full view, and the attribute
733 -- belongs to the type itself, not its underlying parent.
737 elsif Ekind (Ent) = E_Incomplete_Type then
739 -- The attribute applies to the full view, set the entity of the
740 -- attribute definition accordingly.
742 Ent := Underlying_Type (Ent);
744 Set_Entity (Nam, Ent);
747 U_Ent := Underlying_Type (Ent);
750 -- Complete other routine error checks
752 if Etype (Nam) = Any_Type then
755 elsif Scope (Ent) /= Current_Scope then
756 Error_Msg_N ("entity must be declared in this scope", Nam);
759 elsif No (U_Ent) then
762 elsif Is_Type (U_Ent)
763 and then not Is_First_Subtype (U_Ent)
764 and then Id /= Attribute_Object_Size
765 and then Id /= Attribute_Value_Size
766 and then not From_At_Mod (N)
768 Error_Msg_N ("cannot specify attribute for subtype", Nam);
772 -- Switch on particular attribute
780 -- Address attribute definition clause
782 when Attribute_Address => Address : begin
784 -- A little error check, catch for X'Address use X'Address;
786 if Nkind (Nam) = N_Identifier
787 and then Nkind (Expr) = N_Attribute_Reference
788 and then Attribute_Name (Expr) = Name_Address
789 and then Nkind (Prefix (Expr)) = N_Identifier
790 and then Chars (Nam) = Chars (Prefix (Expr))
793 ("address for & is self-referencing", Prefix (Expr), Ent);
797 -- Not that special case, carry on with analysis of expression
799 Analyze_And_Resolve (Expr, RTE (RE_Address));
801 -- Even when ignoring rep clauses we need to indicate that the
802 -- entity has an address clause and thus it is legal to declare
805 if Ignore_Rep_Clauses then
806 if Ekind (U_Ent) = E_Variable
807 or else Ekind (U_Ent) = E_Constant
809 Record_Rep_Item (U_Ent, N);
815 if Present (Address_Clause (U_Ent)) then
816 Error_Msg_N ("address already given for &", Nam);
818 -- Case of address clause for subprogram
820 elsif Is_Subprogram (U_Ent) then
821 if Has_Homonym (U_Ent) then
823 ("address clause cannot be given " &
824 "for overloaded subprogram",
829 -- For subprograms, all address clauses are permitted, and we
830 -- mark the subprogram as having a deferred freeze so that Gigi
831 -- will not elaborate it too soon.
833 -- Above needs more comments, what is too soon about???
835 Set_Has_Delayed_Freeze (U_Ent);
837 -- Case of address clause for entry
839 elsif Ekind (U_Ent) = E_Entry then
840 if Nkind (Parent (N)) = N_Task_Body then
842 ("entry address must be specified in task spec", Nam);
846 -- For entries, we require a constant address
848 Check_Constant_Address_Clause (Expr, U_Ent);
850 -- Special checks for task types
852 if Is_Task_Type (Scope (U_Ent))
853 and then Comes_From_Source (Scope (U_Ent))
856 ("?entry address declared for entry in task type", N);
858 ("\?only one task can be declared of this type", N);
861 -- Entry address clauses are obsolescent
863 Check_Restriction (No_Obsolescent_Features, N);
865 if Warn_On_Obsolescent_Feature then
867 ("attaching interrupt to task entry is an " &
868 "obsolescent feature (RM J.7.1)?", N);
870 ("\use interrupt procedure instead?", N);
873 -- Case of an address clause for a controlled object which we
874 -- consider to be erroneous.
876 elsif Is_Controlled (Etype (U_Ent))
877 or else Has_Controlled_Component (Etype (U_Ent))
880 ("?controlled object& must not be overlaid", Nam, U_Ent);
882 ("\?Program_Error will be raised at run time", Nam);
883 Insert_Action (Declaration_Node (U_Ent),
884 Make_Raise_Program_Error (Loc,
885 Reason => PE_Overlaid_Controlled_Object));
888 -- Case of address clause for a (non-controlled) object
891 Ekind (U_Ent) = E_Variable
893 Ekind (U_Ent) = E_Constant
896 Expr : constant Node_Id := Expression (N);
901 -- Exported variables cannot have an address clause, because
902 -- this cancels the effect of the pragma Export.
904 if Is_Exported (U_Ent) then
906 ("cannot export object with address clause", Nam);
910 Find_Overlaid_Entity (N, O_Ent, Off);
912 -- Overlaying controlled objects is erroneous
915 and then (Has_Controlled_Component (Etype (O_Ent))
916 or else Is_Controlled (Etype (O_Ent)))
919 ("?cannot overlay with controlled object", Expr);
921 ("\?Program_Error will be raised at run time", Expr);
922 Insert_Action (Declaration_Node (U_Ent),
923 Make_Raise_Program_Error (Loc,
924 Reason => PE_Overlaid_Controlled_Object));
927 elsif Present (O_Ent)
928 and then Ekind (U_Ent) = E_Constant
929 and then not Is_Constant_Object (O_Ent)
931 Error_Msg_N ("constant overlays a variable?", Expr);
933 elsif Present (Renamed_Object (U_Ent)) then
935 ("address clause not allowed"
936 & " for a renaming declaration (RM 13.1(6))", Nam);
939 -- Imported variables can have an address clause, but then
940 -- the import is pretty meaningless except to suppress
941 -- initializations, so we do not need such variables to
942 -- be statically allocated (and in fact it causes trouble
943 -- if the address clause is a local value).
945 elsif Is_Imported (U_Ent) then
946 Set_Is_Statically_Allocated (U_Ent, False);
949 -- We mark a possible modification of a variable with an
950 -- address clause, since it is likely aliasing is occurring.
952 Note_Possible_Modification (Nam, Sure => False);
954 -- Here we are checking for explicit overlap of one variable
955 -- by another, and if we find this then mark the overlapped
956 -- variable as also being volatile to prevent unwanted
957 -- optimizations. This is a significant pessimization so
958 -- avoid it when there is an offset, i.e. when the object
959 -- is composite; they cannot be optimized easily anyway.
962 and then Is_Object (O_Ent)
965 Set_Treat_As_Volatile (O_Ent);
968 -- Legality checks on the address clause for initialized
969 -- objects is deferred until the freeze point, because
970 -- a subsequent pragma might indicate that the object is
971 -- imported and thus not initialized.
973 Set_Has_Delayed_Freeze (U_Ent);
975 -- If an initialization call has been generated for this
976 -- object, it needs to be deferred to after the freeze node
977 -- we have just now added, otherwise GIGI will see a
978 -- reference to the variable (as actual to the IP call)
979 -- before its definition.
982 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
984 if Present (Init_Call) then
986 Append_Freeze_Action (U_Ent, Init_Call);
990 if Is_Exported (U_Ent) then
992 ("& cannot be exported if an address clause is given",
995 ("\define and export a variable " &
996 "that holds its address instead",
1000 -- Entity has delayed freeze, so we will generate an
1001 -- alignment check at the freeze point unless suppressed.
1003 if not Range_Checks_Suppressed (U_Ent)
1004 and then not Alignment_Checks_Suppressed (U_Ent)
1006 Set_Check_Address_Alignment (N);
1009 -- Kill the size check code, since we are not allocating
1010 -- the variable, it is somewhere else.
1012 Kill_Size_Check_Code (U_Ent);
1014 -- If the address clause is of the form:
1016 -- for Y'Address use X'Address
1020 -- Const : constant Address := X'Address;
1022 -- for Y'Address use Const;
1024 -- then we make an entry in the table for checking the size
1025 -- and alignment of the overlaying variable. We defer this
1026 -- check till after code generation to take full advantage
1027 -- of the annotation done by the back end. This entry is
1028 -- only made if the address clause comes from source.
1030 if Address_Clause_Overlay_Warnings
1031 and then Comes_From_Source (N)
1032 and then Present (O_Ent)
1033 and then Is_Object (O_Ent)
1035 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1037 -- If variable overlays a constant view, and we are
1038 -- warning on overlays, then mark the variable as
1039 -- overlaying a constant (we will give warnings later
1040 -- if this variable is assigned).
1042 if Is_Constant_Object (O_Ent)
1043 and then Ekind (U_Ent) = E_Variable
1045 Set_Overlays_Constant (U_Ent);
1050 -- Not a valid entity for an address clause
1053 Error_Msg_N ("address cannot be given for &", Nam);
1061 -- Alignment attribute definition clause
1063 when Attribute_Alignment => Alignment : declare
1064 Align : constant Uint := Get_Alignment_Value (Expr);
1069 if not Is_Type (U_Ent)
1070 and then Ekind (U_Ent) /= E_Variable
1071 and then Ekind (U_Ent) /= E_Constant
1073 Error_Msg_N ("alignment cannot be given for &", Nam);
1075 elsif Has_Alignment_Clause (U_Ent) then
1076 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1077 Error_Msg_N ("alignment clause previously given#", N);
1079 elsif Align /= No_Uint then
1080 Set_Has_Alignment_Clause (U_Ent);
1081 Set_Alignment (U_Ent, Align);
1083 -- For an array type, U_Ent is the first subtype. In that case,
1084 -- also set the alignment of the anonymous base type so that
1085 -- other subtypes (such as the itypes for aggregates of the
1086 -- type) also receive the expected alignment.
1088 if Is_Array_Type (U_Ent) then
1089 Set_Alignment (Base_Type (U_Ent), Align);
1098 -- Bit_Order attribute definition clause
1100 when Attribute_Bit_Order => Bit_Order : declare
1102 if not Is_Record_Type (U_Ent) then
1104 ("Bit_Order can only be defined for record type", Nam);
1107 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1109 if Etype (Expr) = Any_Type then
1112 elsif not Is_Static_Expression (Expr) then
1113 Flag_Non_Static_Expr
1114 ("Bit_Order requires static expression!", Expr);
1117 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1118 Set_Reverse_Bit_Order (U_Ent, True);
1124 --------------------
1125 -- Component_Size --
1126 --------------------
1128 -- Component_Size attribute definition clause
1130 when Attribute_Component_Size => Component_Size_Case : declare
1131 Csize : constant Uint := Static_Integer (Expr);
1134 New_Ctyp : Entity_Id;
1138 if not Is_Array_Type (U_Ent) then
1139 Error_Msg_N ("component size requires array type", Nam);
1143 Btype := Base_Type (U_Ent);
1145 if Has_Component_Size_Clause (Btype) then
1147 ("component size clause for& previously given", Nam);
1149 elsif Csize /= No_Uint then
1150 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
1152 if Has_Aliased_Components (Btype)
1155 and then Csize /= 16
1158 ("component size incorrect for aliased components", N);
1162 -- For the biased case, build a declaration for a subtype
1163 -- that will be used to represent the biased subtype that
1164 -- reflects the biased representation of components. We need
1165 -- this subtype to get proper conversions on referencing
1166 -- elements of the array. Note that component size clauses
1167 -- are ignored in VM mode.
1169 if VM_Target = No_VM then
1172 Make_Defining_Identifier (Loc,
1174 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1177 Make_Subtype_Declaration (Loc,
1178 Defining_Identifier => New_Ctyp,
1179 Subtype_Indication =>
1180 New_Occurrence_Of (Component_Type (Btype), Loc));
1182 Set_Parent (Decl, N);
1183 Analyze (Decl, Suppress => All_Checks);
1185 Set_Has_Delayed_Freeze (New_Ctyp, False);
1186 Set_Esize (New_Ctyp, Csize);
1187 Set_RM_Size (New_Ctyp, Csize);
1188 Init_Alignment (New_Ctyp);
1189 Set_Has_Biased_Representation (New_Ctyp, True);
1190 Set_Is_Itype (New_Ctyp, True);
1191 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1193 Set_Component_Type (Btype, New_Ctyp);
1195 if Warn_On_Biased_Representation then
1197 ("?component size clause forces biased "
1198 & "representation", N);
1202 Set_Component_Size (Btype, Csize);
1204 -- For VM case, we ignore component size clauses
1207 -- Give a warning unless we are in GNAT mode, in which case
1208 -- the warning is suppressed since it is not useful.
1210 if not GNAT_Mode then
1212 ("?component size ignored in this configuration", N);
1216 Set_Has_Component_Size_Clause (Btype, True);
1217 Set_Has_Non_Standard_Rep (Btype, True);
1219 end Component_Size_Case;
1225 when Attribute_External_Tag => External_Tag :
1227 if not Is_Tagged_Type (U_Ent) then
1228 Error_Msg_N ("should be a tagged type", Nam);
1231 Analyze_And_Resolve (Expr, Standard_String);
1233 if not Is_Static_Expression (Expr) then
1234 Flag_Non_Static_Expr
1235 ("static string required for tag name!", Nam);
1238 if VM_Target = No_VM then
1239 Set_Has_External_Tag_Rep_Clause (U_Ent);
1241 Error_Msg_Name_1 := Attr;
1243 ("% attribute unsupported in this configuration", Nam);
1246 if not Is_Library_Level_Entity (U_Ent) then
1248 ("?non-unique external tag supplied for &", N, U_Ent);
1250 ("?\same external tag applies to all subprogram calls", N);
1252 ("?\corresponding internal tag cannot be obtained", N);
1260 when Attribute_Input =>
1261 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1262 Set_Has_Specified_Stream_Input (Ent);
1268 -- Machine radix attribute definition clause
1270 when Attribute_Machine_Radix => Machine_Radix : declare
1271 Radix : constant Uint := Static_Integer (Expr);
1274 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1275 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1277 elsif Has_Machine_Radix_Clause (U_Ent) then
1278 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1279 Error_Msg_N ("machine radix clause previously given#", N);
1281 elsif Radix /= No_Uint then
1282 Set_Has_Machine_Radix_Clause (U_Ent);
1283 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1287 elsif Radix = 10 then
1288 Set_Machine_Radix_10 (U_Ent);
1290 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1299 -- Object_Size attribute definition clause
1301 when Attribute_Object_Size => Object_Size : declare
1302 Size : constant Uint := Static_Integer (Expr);
1305 pragma Warnings (Off, Biased);
1308 if not Is_Type (U_Ent) then
1309 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1311 elsif Has_Object_Size_Clause (U_Ent) then
1312 Error_Msg_N ("Object_Size already given for &", Nam);
1315 Check_Size (Expr, U_Ent, Size, Biased);
1323 UI_Mod (Size, 64) /= 0
1326 ("Object_Size must be 8, 16, 32, or multiple of 64",
1330 Set_Esize (U_Ent, Size);
1331 Set_Has_Object_Size_Clause (U_Ent);
1332 Alignment_Check_For_Esize_Change (U_Ent);
1340 when Attribute_Output =>
1341 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1342 Set_Has_Specified_Stream_Output (Ent);
1348 when Attribute_Read =>
1349 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1350 Set_Has_Specified_Stream_Read (Ent);
1356 -- Size attribute definition clause
1358 when Attribute_Size => Size : declare
1359 Size : constant Uint := Static_Integer (Expr);
1366 if Has_Size_Clause (U_Ent) then
1367 Error_Msg_N ("size already given for &", Nam);
1369 elsif not Is_Type (U_Ent)
1370 and then Ekind (U_Ent) /= E_Variable
1371 and then Ekind (U_Ent) /= E_Constant
1373 Error_Msg_N ("size cannot be given for &", Nam);
1375 elsif Is_Array_Type (U_Ent)
1376 and then not Is_Constrained (U_Ent)
1379 ("size cannot be given for unconstrained array", Nam);
1381 elsif Size /= No_Uint then
1382 if Is_Type (U_Ent) then
1385 Etyp := Etype (U_Ent);
1388 -- Check size, note that Gigi is in charge of checking that the
1389 -- size of an array or record type is OK. Also we do not check
1390 -- the size in the ordinary fixed-point case, since it is too
1391 -- early to do so (there may be subsequent small clause that
1392 -- affects the size). We can check the size if a small clause
1393 -- has already been given.
1395 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1396 or else Has_Small_Clause (U_Ent)
1398 Check_Size (Expr, Etyp, Size, Biased);
1399 Set_Has_Biased_Representation (U_Ent, Biased);
1401 if Biased and Warn_On_Biased_Representation then
1403 ("?size clause forces biased representation", N);
1407 -- For types set RM_Size and Esize if possible
1409 if Is_Type (U_Ent) then
1410 Set_RM_Size (U_Ent, Size);
1412 -- For scalar types, increase Object_Size to power of 2, but
1413 -- not less than a storage unit in any case (i.e., normally
1414 -- this means it will be byte addressable).
1416 if Is_Scalar_Type (U_Ent) then
1417 if Size <= System_Storage_Unit then
1418 Init_Esize (U_Ent, System_Storage_Unit);
1419 elsif Size <= 16 then
1420 Init_Esize (U_Ent, 16);
1421 elsif Size <= 32 then
1422 Init_Esize (U_Ent, 32);
1424 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1427 -- For all other types, object size = value size. The
1428 -- backend will adjust as needed.
1431 Set_Esize (U_Ent, Size);
1434 Alignment_Check_For_Esize_Change (U_Ent);
1436 -- For objects, set Esize only
1439 if Is_Elementary_Type (Etyp) then
1440 if Size /= System_Storage_Unit
1442 Size /= System_Storage_Unit * 2
1444 Size /= System_Storage_Unit * 4
1446 Size /= System_Storage_Unit * 8
1448 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1449 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1451 ("size for primitive object must be a power of 2"
1452 & " in the range ^-^", N);
1456 Set_Esize (U_Ent, Size);
1459 Set_Has_Size_Clause (U_Ent);
1467 -- Small attribute definition clause
1469 when Attribute_Small => Small : declare
1470 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1474 Analyze_And_Resolve (Expr, Any_Real);
1476 if Etype (Expr) = Any_Type then
1479 elsif not Is_Static_Expression (Expr) then
1480 Flag_Non_Static_Expr
1481 ("small requires static expression!", Expr);
1485 Small := Expr_Value_R (Expr);
1487 if Small <= Ureal_0 then
1488 Error_Msg_N ("small value must be greater than zero", Expr);
1494 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1496 ("small requires an ordinary fixed point type", Nam);
1498 elsif Has_Small_Clause (U_Ent) then
1499 Error_Msg_N ("small already given for &", Nam);
1501 elsif Small > Delta_Value (U_Ent) then
1503 ("small value must not be greater then delta value", Nam);
1506 Set_Small_Value (U_Ent, Small);
1507 Set_Small_Value (Implicit_Base, Small);
1508 Set_Has_Small_Clause (U_Ent);
1509 Set_Has_Small_Clause (Implicit_Base);
1510 Set_Has_Non_Standard_Rep (Implicit_Base);
1518 -- Storage_Pool attribute definition clause
1520 when Attribute_Storage_Pool => Storage_Pool : declare
1525 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1527 ("storage pool cannot be given for access-to-subprogram type",
1531 elsif Ekind (U_Ent) /= E_Access_Type
1532 and then Ekind (U_Ent) /= E_General_Access_Type
1535 ("storage pool can only be given for access types", Nam);
1538 elsif Is_Derived_Type (U_Ent) then
1540 ("storage pool cannot be given for a derived access type",
1543 elsif Has_Storage_Size_Clause (U_Ent) then
1544 Error_Msg_N ("storage size already given for &", Nam);
1547 elsif Present (Associated_Storage_Pool (U_Ent)) then
1548 Error_Msg_N ("storage pool already given for &", Nam);
1553 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1555 if not Denotes_Variable (Expr) then
1556 Error_Msg_N ("storage pool must be a variable", Expr);
1560 if Nkind (Expr) = N_Type_Conversion then
1561 T := Etype (Expression (Expr));
1566 -- The Stack_Bounded_Pool is used internally for implementing
1567 -- access types with a Storage_Size. Since it only work
1568 -- properly when used on one specific type, we need to check
1569 -- that it is not hijacked improperly:
1570 -- type T is access Integer;
1571 -- for T'Storage_Size use n;
1572 -- type Q is access Float;
1573 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1575 if RTE_Available (RE_Stack_Bounded_Pool)
1576 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1578 Error_Msg_N ("non-shareable internal Pool", Expr);
1582 -- If the argument is a name that is not an entity name, then
1583 -- we construct a renaming operation to define an entity of
1584 -- type storage pool.
1586 if not Is_Entity_Name (Expr)
1587 and then Is_Object_Reference (Expr)
1590 Make_Defining_Identifier (Loc,
1591 Chars => New_Internal_Name ('P'));
1594 Rnode : constant Node_Id :=
1595 Make_Object_Renaming_Declaration (Loc,
1596 Defining_Identifier => Pool,
1598 New_Occurrence_Of (Etype (Expr), Loc),
1602 Insert_Before (N, Rnode);
1604 Set_Associated_Storage_Pool (U_Ent, Pool);
1607 elsif Is_Entity_Name (Expr) then
1608 Pool := Entity (Expr);
1610 -- If pool is a renamed object, get original one. This can
1611 -- happen with an explicit renaming, and within instances.
1613 while Present (Renamed_Object (Pool))
1614 and then Is_Entity_Name (Renamed_Object (Pool))
1616 Pool := Entity (Renamed_Object (Pool));
1619 if Present (Renamed_Object (Pool))
1620 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1621 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1623 Pool := Entity (Expression (Renamed_Object (Pool)));
1626 Set_Associated_Storage_Pool (U_Ent, Pool);
1628 elsif Nkind (Expr) = N_Type_Conversion
1629 and then Is_Entity_Name (Expression (Expr))
1630 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1632 Pool := Entity (Expression (Expr));
1633 Set_Associated_Storage_Pool (U_Ent, Pool);
1636 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1645 -- Storage_Size attribute definition clause
1647 when Attribute_Storage_Size => Storage_Size : declare
1648 Btype : constant Entity_Id := Base_Type (U_Ent);
1652 if Is_Task_Type (U_Ent) then
1653 Check_Restriction (No_Obsolescent_Features, N);
1655 if Warn_On_Obsolescent_Feature then
1657 ("storage size clause for task is an " &
1658 "obsolescent feature (RM J.9)?", N);
1660 ("\use Storage_Size pragma instead?", N);
1666 if not Is_Access_Type (U_Ent)
1667 and then Ekind (U_Ent) /= E_Task_Type
1669 Error_Msg_N ("storage size cannot be given for &", Nam);
1671 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1673 ("storage size cannot be given for a derived access type",
1676 elsif Has_Storage_Size_Clause (Btype) then
1677 Error_Msg_N ("storage size already given for &", Nam);
1680 Analyze_And_Resolve (Expr, Any_Integer);
1682 if Is_Access_Type (U_Ent) then
1683 if Present (Associated_Storage_Pool (U_Ent)) then
1684 Error_Msg_N ("storage pool already given for &", Nam);
1688 if Compile_Time_Known_Value (Expr)
1689 and then Expr_Value (Expr) = 0
1691 Set_No_Pool_Assigned (Btype);
1694 else -- Is_Task_Type (U_Ent)
1695 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1697 if Present (Sprag) then
1698 Error_Msg_Sloc := Sloc (Sprag);
1700 ("Storage_Size already specified#", Nam);
1705 Set_Has_Storage_Size_Clause (Btype);
1713 when Attribute_Stream_Size => Stream_Size : declare
1714 Size : constant Uint := Static_Integer (Expr);
1717 if Ada_Version <= Ada_95 then
1718 Check_Restriction (No_Implementation_Attributes, N);
1721 if Has_Stream_Size_Clause (U_Ent) then
1722 Error_Msg_N ("Stream_Size already given for &", Nam);
1724 elsif Is_Elementary_Type (U_Ent) then
1725 if Size /= System_Storage_Unit
1727 Size /= System_Storage_Unit * 2
1729 Size /= System_Storage_Unit * 4
1731 Size /= System_Storage_Unit * 8
1733 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1735 ("stream size for elementary type must be a"
1736 & " power of 2 and at least ^", N);
1738 elsif RM_Size (U_Ent) > Size then
1739 Error_Msg_Uint_1 := RM_Size (U_Ent);
1741 ("stream size for elementary type must be a"
1742 & " power of 2 and at least ^", N);
1745 Set_Has_Stream_Size_Clause (U_Ent);
1748 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1756 -- Value_Size attribute definition clause
1758 when Attribute_Value_Size => Value_Size : declare
1759 Size : constant Uint := Static_Integer (Expr);
1763 if not Is_Type (U_Ent) then
1764 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1767 (Get_Attribute_Definition_Clause
1768 (U_Ent, Attribute_Value_Size))
1770 Error_Msg_N ("Value_Size already given for &", Nam);
1772 elsif Is_Array_Type (U_Ent)
1773 and then not Is_Constrained (U_Ent)
1776 ("Value_Size cannot be given for unconstrained array", Nam);
1779 if Is_Elementary_Type (U_Ent) then
1780 Check_Size (Expr, U_Ent, Size, Biased);
1781 Set_Has_Biased_Representation (U_Ent, Biased);
1783 if Biased and Warn_On_Biased_Representation then
1785 ("?value size clause forces biased representation", N);
1789 Set_RM_Size (U_Ent, Size);
1797 when Attribute_Write =>
1798 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1799 Set_Has_Specified_Stream_Write (Ent);
1801 -- All other attributes cannot be set
1805 ("attribute& cannot be set with definition clause", N);
1808 -- The test for the type being frozen must be performed after
1809 -- any expression the clause has been analyzed since the expression
1810 -- itself might cause freezing that makes the clause illegal.
1812 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1815 end Analyze_Attribute_Definition_Clause;
1817 ----------------------------
1818 -- Analyze_Code_Statement --
1819 ----------------------------
1821 procedure Analyze_Code_Statement (N : Node_Id) is
1822 HSS : constant Node_Id := Parent (N);
1823 SBody : constant Node_Id := Parent (HSS);
1824 Subp : constant Entity_Id := Current_Scope;
1831 -- Analyze and check we get right type, note that this implements the
1832 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1833 -- is the only way that Asm_Insn could possibly be visible.
1835 Analyze_And_Resolve (Expression (N));
1837 if Etype (Expression (N)) = Any_Type then
1839 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1840 Error_Msg_N ("incorrect type for code statement", N);
1844 Check_Code_Statement (N);
1846 -- Make sure we appear in the handled statement sequence of a
1847 -- subprogram (RM 13.8(3)).
1849 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
1850 or else Nkind (SBody) /= N_Subprogram_Body
1853 ("code statement can only appear in body of subprogram", N);
1857 -- Do remaining checks (RM 13.8(3)) if not already done
1859 if not Is_Machine_Code_Subprogram (Subp) then
1860 Set_Is_Machine_Code_Subprogram (Subp);
1862 -- No exception handlers allowed
1864 if Present (Exception_Handlers (HSS)) then
1866 ("exception handlers not permitted in machine code subprogram",
1867 First (Exception_Handlers (HSS)));
1870 -- No declarations other than use clauses and pragmas (we allow
1871 -- certain internally generated declarations as well).
1873 Decl := First (Declarations (SBody));
1874 while Present (Decl) loop
1875 DeclO := Original_Node (Decl);
1876 if Comes_From_Source (DeclO)
1877 and not Nkind_In (DeclO, N_Pragma,
1878 N_Use_Package_Clause,
1880 N_Implicit_Label_Declaration)
1883 ("this declaration not allowed in machine code subprogram",
1890 -- No statements other than code statements, pragmas, and labels.
1891 -- Again we allow certain internally generated statements.
1893 Stmt := First (Statements (HSS));
1894 while Present (Stmt) loop
1895 StmtO := Original_Node (Stmt);
1896 if Comes_From_Source (StmtO)
1897 and then not Nkind_In (StmtO, N_Pragma,
1902 ("this statement is not allowed in machine code subprogram",
1909 end Analyze_Code_Statement;
1911 -----------------------------------------------
1912 -- Analyze_Enumeration_Representation_Clause --
1913 -----------------------------------------------
1915 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
1916 Ident : constant Node_Id := Identifier (N);
1917 Aggr : constant Node_Id := Array_Aggregate (N);
1918 Enumtype : Entity_Id;
1924 Err : Boolean := False;
1926 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
1927 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
1932 if Ignore_Rep_Clauses then
1936 -- First some basic error checks
1939 Enumtype := Entity (Ident);
1941 if Enumtype = Any_Type
1942 or else Rep_Item_Too_Early (Enumtype, N)
1946 Enumtype := Underlying_Type (Enumtype);
1949 if not Is_Enumeration_Type (Enumtype) then
1951 ("enumeration type required, found}",
1952 Ident, First_Subtype (Enumtype));
1956 -- Ignore rep clause on generic actual type. This will already have
1957 -- been flagged on the template as an error, and this is the safest
1958 -- way to ensure we don't get a junk cascaded message in the instance.
1960 if Is_Generic_Actual_Type (Enumtype) then
1963 -- Type must be in current scope
1965 elsif Scope (Enumtype) /= Current_Scope then
1966 Error_Msg_N ("type must be declared in this scope", Ident);
1969 -- Type must be a first subtype
1971 elsif not Is_First_Subtype (Enumtype) then
1972 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
1975 -- Ignore duplicate rep clause
1977 elsif Has_Enumeration_Rep_Clause (Enumtype) then
1978 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
1981 -- Don't allow rep clause for standard [wide_[wide_]]character
1983 elsif Is_Standard_Character_Type (Enumtype) then
1984 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
1987 -- Check that the expression is a proper aggregate (no parentheses)
1989 elsif Paren_Count (Aggr) /= 0 then
1991 ("extra parentheses surrounding aggregate not allowed",
1995 -- All tests passed, so set rep clause in place
1998 Set_Has_Enumeration_Rep_Clause (Enumtype);
1999 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2002 -- Now we process the aggregate. Note that we don't use the normal
2003 -- aggregate code for this purpose, because we don't want any of the
2004 -- normal expansion activities, and a number of special semantic
2005 -- rules apply (including the component type being any integer type)
2007 Elit := First_Literal (Enumtype);
2009 -- First the positional entries if any
2011 if Present (Expressions (Aggr)) then
2012 Expr := First (Expressions (Aggr));
2013 while Present (Expr) loop
2015 Error_Msg_N ("too many entries in aggregate", Expr);
2019 Val := Static_Integer (Expr);
2021 -- Err signals that we found some incorrect entries processing
2022 -- the list. The final checks for completeness and ordering are
2023 -- skipped in this case.
2025 if Val = No_Uint then
2027 elsif Val < Lo or else Hi < Val then
2028 Error_Msg_N ("value outside permitted range", Expr);
2032 Set_Enumeration_Rep (Elit, Val);
2033 Set_Enumeration_Rep_Expr (Elit, Expr);
2039 -- Now process the named entries if present
2041 if Present (Component_Associations (Aggr)) then
2042 Assoc := First (Component_Associations (Aggr));
2043 while Present (Assoc) loop
2044 Choice := First (Choices (Assoc));
2046 if Present (Next (Choice)) then
2048 ("multiple choice not allowed here", Next (Choice));
2052 if Nkind (Choice) = N_Others_Choice then
2053 Error_Msg_N ("others choice not allowed here", Choice);
2056 elsif Nkind (Choice) = N_Range then
2057 -- ??? should allow zero/one element range here
2058 Error_Msg_N ("range not allowed here", Choice);
2062 Analyze_And_Resolve (Choice, Enumtype);
2064 if Is_Entity_Name (Choice)
2065 and then Is_Type (Entity (Choice))
2067 Error_Msg_N ("subtype name not allowed here", Choice);
2069 -- ??? should allow static subtype with zero/one entry
2071 elsif Etype (Choice) = Base_Type (Enumtype) then
2072 if not Is_Static_Expression (Choice) then
2073 Flag_Non_Static_Expr
2074 ("non-static expression used for choice!", Choice);
2078 Elit := Expr_Value_E (Choice);
2080 if Present (Enumeration_Rep_Expr (Elit)) then
2081 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2083 ("representation for& previously given#",
2088 Set_Enumeration_Rep_Expr (Elit, Choice);
2090 Expr := Expression (Assoc);
2091 Val := Static_Integer (Expr);
2093 if Val = No_Uint then
2096 elsif Val < Lo or else Hi < Val then
2097 Error_Msg_N ("value outside permitted range", Expr);
2101 Set_Enumeration_Rep (Elit, Val);
2110 -- Aggregate is fully processed. Now we check that a full set of
2111 -- representations was given, and that they are in range and in order.
2112 -- These checks are only done if no other errors occurred.
2118 Elit := First_Literal (Enumtype);
2119 while Present (Elit) loop
2120 if No (Enumeration_Rep_Expr (Elit)) then
2121 Error_Msg_NE ("missing representation for&!", N, Elit);
2124 Val := Enumeration_Rep (Elit);
2126 if Min = No_Uint then
2130 if Val /= No_Uint then
2131 if Max /= No_Uint and then Val <= Max then
2133 ("enumeration value for& not ordered!",
2134 Enumeration_Rep_Expr (Elit), Elit);
2140 -- If there is at least one literal whose representation
2141 -- is not equal to the Pos value, then note that this
2142 -- enumeration type has a non-standard representation.
2144 if Val /= Enumeration_Pos (Elit) then
2145 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2152 -- Now set proper size information
2155 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2158 if Has_Size_Clause (Enumtype) then
2159 if Esize (Enumtype) >= Minsize then
2164 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2166 if Esize (Enumtype) < Minsize then
2167 Error_Msg_N ("previously given size is too small", N);
2170 Set_Has_Biased_Representation (Enumtype);
2175 Set_RM_Size (Enumtype, Minsize);
2176 Set_Enum_Esize (Enumtype);
2179 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2180 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2181 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2185 -- We repeat the too late test in case it froze itself!
2187 if Rep_Item_Too_Late (Enumtype, N) then
2190 end Analyze_Enumeration_Representation_Clause;
2192 ----------------------------
2193 -- Analyze_Free_Statement --
2194 ----------------------------
2196 procedure Analyze_Free_Statement (N : Node_Id) is
2198 Analyze (Expression (N));
2199 end Analyze_Free_Statement;
2201 ---------------------------
2202 -- Analyze_Freeze_Entity --
2203 ---------------------------
2205 -- This does not belong in sem_ch13, and I don't like the big new
2206 -- dependency on sem_ch3, I would in fact move this to sem_ch3 or
2207 -- somewhere else, and then Add_Internal_Interface_Entitites can be
2208 -- private to sem_ch3.adb. ???
2210 procedure Analyze_Freeze_Entity (N : Node_Id) is
2211 E : constant Entity_Id := Entity (N);
2214 -- For tagged types covering interfaces add internal entities that link
2215 -- the primitives of the interfaces with the primitives that cover them.
2217 -- Note: These entities were originally generated only when generating
2218 -- code because their main purpose was to provide support to initialize
2219 -- the secondary dispatch tables. They are now generated also when
2220 -- compiling with no code generation to provide ASIS the relationship
2221 -- between interface primitives and tagged type primitives.
2223 if Ada_Version >= Ada_05
2224 and then Ekind (E) = E_Record_Type
2225 and then Is_Tagged_Type (E)
2226 and then not Is_Interface (E)
2227 and then Has_Interfaces (E)
2229 Add_Internal_Interface_Entities (E);
2231 end Analyze_Freeze_Entity;
2233 ------------------------------------------
2234 -- Analyze_Record_Representation_Clause --
2235 ------------------------------------------
2237 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2238 Loc : constant Source_Ptr := Sloc (N);
2239 Ident : constant Node_Id := Identifier (N);
2240 Rectype : Entity_Id;
2246 Hbit : Uint := Uint_0;
2252 Max_Bit_So_Far : Uint;
2253 -- Records the maximum bit position so far. If all field positions
2254 -- are monotonically increasing, then we can skip the circuit for
2255 -- checking for overlap, since no overlap is possible.
2257 Tagged_Parent : Entity_Id := Empty;
2258 -- This is set in the case of a derived tagged type for which we have
2259 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
2260 -- positioned by record representation clauses). In this case we must
2261 -- check for overlap between components of this tagged type, and the
2262 -- components of its parent. Tagged_Parent will point to this parent
2263 -- type. For all other cases Tagged_Parent is left set to Empty.
2265 Parent_Last_Bit : Uint;
2266 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
2267 -- last bit position for any field in the parent type. We only need to
2268 -- check overlap for fields starting below this point.
2270 Overlap_Check_Required : Boolean;
2271 -- Used to keep track of whether or not an overlap check is required
2273 Ccount : Natural := 0;
2274 -- Number of component clauses in record rep clause
2276 CR_Pragma : Node_Id := Empty;
2277 -- Points to N_Pragma node if Complete_Representation pragma present
2280 if Ignore_Rep_Clauses then
2285 Rectype := Entity (Ident);
2287 if Rectype = Any_Type
2288 or else Rep_Item_Too_Early (Rectype, N)
2292 Rectype := Underlying_Type (Rectype);
2295 -- First some basic error checks
2297 if not Is_Record_Type (Rectype) then
2299 ("record type required, found}", Ident, First_Subtype (Rectype));
2302 elsif Is_Unchecked_Union (Rectype) then
2304 ("record rep clause not allowed for Unchecked_Union", N);
2306 elsif Scope (Rectype) /= Current_Scope then
2307 Error_Msg_N ("type must be declared in this scope", N);
2310 elsif not Is_First_Subtype (Rectype) then
2311 Error_Msg_N ("cannot give record rep clause for subtype", N);
2314 elsif Has_Record_Rep_Clause (Rectype) then
2315 Error_Msg_N ("duplicate record rep clause ignored", N);
2318 elsif Rep_Item_Too_Late (Rectype, N) then
2322 if Present (Mod_Clause (N)) then
2324 Loc : constant Source_Ptr := Sloc (N);
2325 M : constant Node_Id := Mod_Clause (N);
2326 P : constant List_Id := Pragmas_Before (M);
2330 pragma Warnings (Off, Mod_Val);
2333 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2335 if Warn_On_Obsolescent_Feature then
2337 ("mod clause is an obsolescent feature (RM J.8)?", N);
2339 ("\use alignment attribute definition clause instead?", N);
2346 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2347 -- the Mod clause into an alignment clause anyway, so that the
2348 -- back-end can compute and back-annotate properly the size and
2349 -- alignment of types that may include this record.
2351 -- This seems dubious, this destroys the source tree in a manner
2352 -- not detectable by ASIS ???
2354 if Operating_Mode = Check_Semantics
2358 Make_Attribute_Definition_Clause (Loc,
2359 Name => New_Reference_To (Base_Type (Rectype), Loc),
2360 Chars => Name_Alignment,
2361 Expression => Relocate_Node (Expression (M)));
2363 Set_From_At_Mod (AtM_Nod);
2364 Insert_After (N, AtM_Nod);
2365 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2366 Set_Mod_Clause (N, Empty);
2369 -- Get the alignment value to perform error checking
2371 Mod_Val := Get_Alignment_Value (Expression (M));
2377 -- For untagged types, clear any existing component clauses for the
2378 -- type. If the type is derived, this is what allows us to override
2379 -- a rep clause for the parent. For type extensions, the representation
2380 -- of the inherited components is inherited, so we want to keep previous
2381 -- component clauses for completeness.
2383 if not Is_Tagged_Type (Rectype) then
2384 Comp := First_Component_Or_Discriminant (Rectype);
2385 while Present (Comp) loop
2386 Set_Component_Clause (Comp, Empty);
2387 Next_Component_Or_Discriminant (Comp);
2391 -- See if we have a fully repped derived tagged type
2394 PS : constant Entity_Id := Parent_Subtype (Rectype);
2397 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
2398 Tagged_Parent := PS;
2400 -- Find maximum bit of any component of the parent type
2402 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
2403 Pcomp := First_Entity (Tagged_Parent);
2404 while Present (Pcomp) loop
2405 if Ekind (Pcomp) = E_Discriminant
2407 Ekind (Pcomp) = E_Component
2409 if Component_Bit_Offset (Pcomp) /= No_Uint
2410 and then Known_Static_Esize (Pcomp)
2415 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
2418 Next_Entity (Pcomp);
2424 -- All done if no component clauses
2426 CC := First (Component_Clauses (N));
2432 -- If a tag is present, then create a component clause that places it
2433 -- at the start of the record (otherwise gigi may place it after other
2434 -- fields that have rep clauses).
2436 Fent := First_Entity (Rectype);
2438 if Nkind (Fent) = N_Defining_Identifier
2439 and then Chars (Fent) = Name_uTag
2441 Set_Component_Bit_Offset (Fent, Uint_0);
2442 Set_Normalized_Position (Fent, Uint_0);
2443 Set_Normalized_First_Bit (Fent, Uint_0);
2444 Set_Normalized_Position_Max (Fent, Uint_0);
2445 Init_Esize (Fent, System_Address_Size);
2447 Set_Component_Clause (Fent,
2448 Make_Component_Clause (Loc,
2450 Make_Identifier (Loc,
2451 Chars => Name_uTag),
2454 Make_Integer_Literal (Loc,
2458 Make_Integer_Literal (Loc,
2462 Make_Integer_Literal (Loc,
2463 UI_From_Int (System_Address_Size))));
2465 Ccount := Ccount + 1;
2468 -- A representation like this applies to the base type
2470 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2471 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2472 Set_Has_Specified_Layout (Base_Type (Rectype));
2474 Max_Bit_So_Far := Uint_Minus_1;
2475 Overlap_Check_Required := False;
2477 -- Process the component clauses
2479 while Present (CC) loop
2483 if Nkind (CC) = N_Pragma then
2486 -- The only pragma of interest is Complete_Representation
2488 if Pragma_Name (CC) = Name_Complete_Representation then
2492 -- Processing for real component clause
2495 Ccount := Ccount + 1;
2496 Posit := Static_Integer (Position (CC));
2497 Fbit := Static_Integer (First_Bit (CC));
2498 Lbit := Static_Integer (Last_Bit (CC));
2501 and then Fbit /= No_Uint
2502 and then Lbit /= No_Uint
2506 ("position cannot be negative", Position (CC));
2510 ("first bit cannot be negative", First_Bit (CC));
2512 -- The Last_Bit specified in a component clause must not be
2513 -- less than the First_Bit minus one (RM-13.5.1(10)).
2515 elsif Lbit < Fbit - 1 then
2517 ("last bit cannot be less than first bit minus one",
2520 -- Values look OK, so find the corresponding record component
2521 -- Even though the syntax allows an attribute reference for
2522 -- implementation-defined components, GNAT does not allow the
2523 -- tag to get an explicit position.
2525 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2526 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2527 Error_Msg_N ("position of tag cannot be specified", CC);
2529 Error_Msg_N ("illegal component name", CC);
2533 Comp := First_Entity (Rectype);
2534 while Present (Comp) loop
2535 exit when Chars (Comp) = Chars (Component_Name (CC));
2541 -- Maybe component of base type that is absent from
2542 -- statically constrained first subtype.
2544 Comp := First_Entity (Base_Type (Rectype));
2545 while Present (Comp) loop
2546 exit when Chars (Comp) = Chars (Component_Name (CC));
2553 ("component clause is for non-existent field", CC);
2555 elsif Present (Component_Clause (Comp)) then
2557 -- Diagnose duplicate rep clause, or check consistency
2558 -- if this is an inherited component. In a double fault,
2559 -- there may be a duplicate inconsistent clause for an
2560 -- inherited component.
2562 if Scope (Original_Record_Component (Comp)) = Rectype
2563 or else Parent (Component_Clause (Comp)) = N
2565 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2566 Error_Msg_N ("component clause previously given#", CC);
2570 Rep1 : constant Node_Id := Component_Clause (Comp);
2572 if Intval (Position (Rep1)) /=
2573 Intval (Position (CC))
2574 or else Intval (First_Bit (Rep1)) /=
2575 Intval (First_Bit (CC))
2576 or else Intval (Last_Bit (Rep1)) /=
2577 Intval (Last_Bit (CC))
2579 Error_Msg_N ("component clause inconsistent "
2580 & "with representation of ancestor", CC);
2581 elsif Warn_On_Redundant_Constructs then
2582 Error_Msg_N ("?redundant component clause "
2583 & "for inherited component!", CC);
2588 -- Normal case where this is the first component clause we
2589 -- have seen for this entity, so set it up properly.
2592 -- Make reference for field in record rep clause and set
2593 -- appropriate entity field in the field identifier.
2596 (Comp, Component_Name (CC), Set_Ref => False);
2597 Set_Entity (Component_Name (CC), Comp);
2599 -- Update Fbit and Lbit to the actual bit number
2601 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2602 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2604 if Fbit <= Max_Bit_So_Far then
2605 Overlap_Check_Required := True;
2607 Max_Bit_So_Far := Lbit;
2610 if Has_Size_Clause (Rectype)
2611 and then Esize (Rectype) <= Lbit
2614 ("bit number out of range of specified size",
2617 Set_Component_Clause (Comp, CC);
2618 Set_Component_Bit_Offset (Comp, Fbit);
2619 Set_Esize (Comp, 1 + (Lbit - Fbit));
2620 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2621 Set_Normalized_Position (Comp, Fbit / SSU);
2623 Set_Normalized_Position_Max
2624 (Fent, Normalized_Position (Fent));
2626 if Is_Tagged_Type (Rectype)
2627 and then Fbit < System_Address_Size
2630 ("component overlaps tag field of&",
2631 Component_Name (CC), Rectype);
2634 -- This information is also set in the corresponding
2635 -- component of the base type, found by accessing the
2636 -- Original_Record_Component link if it is present.
2638 Ocomp := Original_Record_Component (Comp);
2645 (Component_Name (CC),
2650 Set_Has_Biased_Representation (Comp, Biased);
2652 if Biased and Warn_On_Biased_Representation then
2654 ("?component clause forces biased "
2655 & "representation", CC);
2658 if Present (Ocomp) then
2659 Set_Component_Clause (Ocomp, CC);
2660 Set_Component_Bit_Offset (Ocomp, Fbit);
2661 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2662 Set_Normalized_Position (Ocomp, Fbit / SSU);
2663 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2665 Set_Normalized_Position_Max
2666 (Ocomp, Normalized_Position (Ocomp));
2668 Set_Has_Biased_Representation
2669 (Ocomp, Has_Biased_Representation (Comp));
2672 if Esize (Comp) < 0 then
2673 Error_Msg_N ("component size is negative", CC);
2677 -- If OK component size, check parent type overlap if
2678 -- this component might overlap a parent field.
2680 if Present (Tagged_Parent)
2681 and then Fbit <= Parent_Last_Bit
2683 Pcomp := First_Entity (Tagged_Parent);
2684 while Present (Pcomp) loop
2685 if (Ekind (Pcomp) = E_Discriminant
2687 Ekind (Pcomp) = E_Component)
2688 and then not Is_Tag (Pcomp)
2689 and then Chars (Pcomp) /= Name_uParent
2691 Check_Component_Overlap (Comp, Pcomp);
2694 Next_Entity (Pcomp);
2705 -- Now that we have processed all the component clauses, check for
2706 -- overlap. We have to leave this till last, since the components can
2707 -- appear in any arbitrary order in the representation clause.
2709 -- We do not need this check if all specified ranges were monotonic,
2710 -- as recorded by Overlap_Check_Required being False at this stage.
2712 -- This first section checks if there are any overlapping entries at
2713 -- all. It does this by sorting all entries and then seeing if there are
2714 -- any overlaps. If there are none, then that is decisive, but if there
2715 -- are overlaps, they may still be OK (they may result from fields in
2716 -- different variants).
2718 if Overlap_Check_Required then
2719 Overlap_Check1 : declare
2721 OC_Fbit : array (0 .. Ccount) of Uint;
2722 -- First-bit values for component clauses, the value is the offset
2723 -- of the first bit of the field from start of record. The zero
2724 -- entry is for use in sorting.
2726 OC_Lbit : array (0 .. Ccount) of Uint;
2727 -- Last-bit values for component clauses, the value is the offset
2728 -- of the last bit of the field from start of record. The zero
2729 -- entry is for use in sorting.
2731 OC_Count : Natural := 0;
2732 -- Count of entries in OC_Fbit and OC_Lbit
2734 function OC_Lt (Op1, Op2 : Natural) return Boolean;
2735 -- Compare routine for Sort
2737 procedure OC_Move (From : Natural; To : Natural);
2738 -- Move routine for Sort
2740 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
2746 function OC_Lt (Op1, Op2 : Natural) return Boolean is
2748 return OC_Fbit (Op1) < OC_Fbit (Op2);
2755 procedure OC_Move (From : Natural; To : Natural) is
2757 OC_Fbit (To) := OC_Fbit (From);
2758 OC_Lbit (To) := OC_Lbit (From);
2761 -- Start of processing for Overlap_Check
2764 CC := First (Component_Clauses (N));
2765 while Present (CC) loop
2766 if Nkind (CC) /= N_Pragma then
2767 Posit := Static_Integer (Position (CC));
2768 Fbit := Static_Integer (First_Bit (CC));
2769 Lbit := Static_Integer (Last_Bit (CC));
2772 and then Fbit /= No_Uint
2773 and then Lbit /= No_Uint
2775 OC_Count := OC_Count + 1;
2776 Posit := Posit * SSU;
2777 OC_Fbit (OC_Count) := Fbit + Posit;
2778 OC_Lbit (OC_Count) := Lbit + Posit;
2785 Sorting.Sort (OC_Count);
2787 Overlap_Check_Required := False;
2788 for J in 1 .. OC_Count - 1 loop
2789 if OC_Lbit (J) >= OC_Fbit (J + 1) then
2790 Overlap_Check_Required := True;
2797 -- If Overlap_Check_Required is still True, then we have to do the full
2798 -- scale overlap check, since we have at least two fields that do
2799 -- overlap, and we need to know if that is OK since they are in
2800 -- different variant, or whether we have a definite problem.
2802 if Overlap_Check_Required then
2803 Overlap_Check2 : declare
2804 C1_Ent, C2_Ent : Entity_Id;
2805 -- Entities of components being checked for overlap
2808 -- Component_List node whose Component_Items are being checked
2811 -- Component declaration for component being checked
2814 C1_Ent := First_Entity (Base_Type (Rectype));
2816 -- Loop through all components in record. For each component check
2817 -- for overlap with any of the preceding elements on the component
2818 -- list containing the component and also, if the component is in
2819 -- a variant, check against components outside the case structure.
2820 -- This latter test is repeated recursively up the variant tree.
2822 Main_Component_Loop : while Present (C1_Ent) loop
2823 if Ekind (C1_Ent) /= E_Component
2824 and then Ekind (C1_Ent) /= E_Discriminant
2826 goto Continue_Main_Component_Loop;
2829 -- Skip overlap check if entity has no declaration node. This
2830 -- happens with discriminants in constrained derived types.
2831 -- Probably we are missing some checks as a result, but that
2832 -- does not seem terribly serious ???
2834 if No (Declaration_Node (C1_Ent)) then
2835 goto Continue_Main_Component_Loop;
2838 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
2840 -- Loop through component lists that need checking. Check the
2841 -- current component list and all lists in variants above us.
2843 Component_List_Loop : loop
2845 -- If derived type definition, go to full declaration
2846 -- If at outer level, check discriminants if there are any.
2848 if Nkind (Clist) = N_Derived_Type_Definition then
2849 Clist := Parent (Clist);
2852 -- Outer level of record definition, check discriminants
2854 if Nkind_In (Clist, N_Full_Type_Declaration,
2855 N_Private_Type_Declaration)
2857 if Has_Discriminants (Defining_Identifier (Clist)) then
2859 First_Discriminant (Defining_Identifier (Clist));
2860 while Present (C2_Ent) loop
2861 exit when C1_Ent = C2_Ent;
2862 Check_Component_Overlap (C1_Ent, C2_Ent);
2863 Next_Discriminant (C2_Ent);
2867 -- Record extension case
2869 elsif Nkind (Clist) = N_Derived_Type_Definition then
2872 -- Otherwise check one component list
2875 Citem := First (Component_Items (Clist));
2877 while Present (Citem) loop
2878 if Nkind (Citem) = N_Component_Declaration then
2879 C2_Ent := Defining_Identifier (Citem);
2880 exit when C1_Ent = C2_Ent;
2881 Check_Component_Overlap (C1_Ent, C2_Ent);
2888 -- Check for variants above us (the parent of the Clist can
2889 -- be a variant, in which case its parent is a variant part,
2890 -- and the parent of the variant part is a component list
2891 -- whose components must all be checked against the current
2892 -- component for overlap).
2894 if Nkind (Parent (Clist)) = N_Variant then
2895 Clist := Parent (Parent (Parent (Clist)));
2897 -- Check for possible discriminant part in record, this is
2898 -- treated essentially as another level in the recursion.
2899 -- For this case the parent of the component list is the
2900 -- record definition, and its parent is the full type
2901 -- declaration containing the discriminant specifications.
2903 elsif Nkind (Parent (Clist)) = N_Record_Definition then
2904 Clist := Parent (Parent ((Clist)));
2906 -- If neither of these two cases, we are at the top of
2910 exit Component_List_Loop;
2912 end loop Component_List_Loop;
2914 <<Continue_Main_Component_Loop>>
2915 Next_Entity (C1_Ent);
2917 end loop Main_Component_Loop;
2921 -- For records that have component clauses for all components, and whose
2922 -- size is less than or equal to 32, we need to know the size in the
2923 -- front end to activate possible packed array processing where the
2924 -- component type is a record.
2926 -- At this stage Hbit + 1 represents the first unused bit from all the
2927 -- component clauses processed, so if the component clauses are
2928 -- complete, then this is the length of the record.
2930 -- For records longer than System.Storage_Unit, and for those where not
2931 -- all components have component clauses, the back end determines the
2932 -- length (it may for example be appropriate to round up the size
2933 -- to some convenient boundary, based on alignment considerations, etc).
2935 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
2937 -- Nothing to do if at least one component has no component clause
2939 Comp := First_Component_Or_Discriminant (Rectype);
2940 while Present (Comp) loop
2941 exit when No (Component_Clause (Comp));
2942 Next_Component_Or_Discriminant (Comp);
2945 -- If we fall out of loop, all components have component clauses
2946 -- and so we can set the size to the maximum value.
2949 Set_RM_Size (Rectype, Hbit + 1);
2953 -- Check missing components if Complete_Representation pragma appeared
2955 if Present (CR_Pragma) then
2956 Comp := First_Component_Or_Discriminant (Rectype);
2957 while Present (Comp) loop
2958 if No (Component_Clause (Comp)) then
2960 ("missing component clause for &", CR_Pragma, Comp);
2963 Next_Component_Or_Discriminant (Comp);
2966 -- If no Complete_Representation pragma, warn if missing components
2968 elsif Warn_On_Unrepped_Components then
2970 Num_Repped_Components : Nat := 0;
2971 Num_Unrepped_Components : Nat := 0;
2974 -- First count number of repped and unrepped components
2976 Comp := First_Component_Or_Discriminant (Rectype);
2977 while Present (Comp) loop
2978 if Present (Component_Clause (Comp)) then
2979 Num_Repped_Components := Num_Repped_Components + 1;
2981 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2984 Next_Component_Or_Discriminant (Comp);
2987 -- We are only interested in the case where there is at least one
2988 -- unrepped component, and at least half the components have rep
2989 -- clauses. We figure that if less than half have them, then the
2990 -- partial rep clause is really intentional. If the component
2991 -- type has no underlying type set at this point (as for a generic
2992 -- formal type), we don't know enough to give a warning on the
2995 if Num_Unrepped_Components > 0
2996 and then Num_Unrepped_Components < Num_Repped_Components
2998 Comp := First_Component_Or_Discriminant (Rectype);
2999 while Present (Comp) loop
3000 if No (Component_Clause (Comp))
3001 and then Comes_From_Source (Comp)
3002 and then Present (Underlying_Type (Etype (Comp)))
3003 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
3004 or else Size_Known_At_Compile_Time
3005 (Underlying_Type (Etype (Comp))))
3006 and then not Has_Warnings_Off (Rectype)
3008 Error_Msg_Sloc := Sloc (Comp);
3010 ("?no component clause given for & declared #",
3014 Next_Component_Or_Discriminant (Comp);
3019 end Analyze_Record_Representation_Clause;
3021 -----------------------------
3022 -- Check_Component_Overlap --
3023 -----------------------------
3025 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
3027 if Present (Component_Clause (C1_Ent))
3028 and then Present (Component_Clause (C2_Ent))
3030 -- Exclude odd case where we have two tag fields in the same record,
3031 -- both at location zero. This seems a bit strange, but it seems to
3032 -- happen in some circumstances ???
3034 if Chars (C1_Ent) = Name_uTag
3035 and then Chars (C2_Ent) = Name_uTag
3040 -- Here we check if the two fields overlap
3043 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
3044 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
3045 E1 : constant Uint := S1 + Esize (C1_Ent);
3046 E2 : constant Uint := S2 + Esize (C2_Ent);
3049 if E2 <= S1 or else E1 <= S2 then
3053 Component_Name (Component_Clause (C2_Ent));
3054 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
3056 Component_Name (Component_Clause (C1_Ent));
3058 ("component& overlaps & #",
3059 Component_Name (Component_Clause (C1_Ent)));
3063 end Check_Component_Overlap;
3065 -----------------------------------
3066 -- Check_Constant_Address_Clause --
3067 -----------------------------------
3069 procedure Check_Constant_Address_Clause
3073 procedure Check_At_Constant_Address (Nod : Node_Id);
3074 -- Checks that the given node N represents a name whose 'Address is
3075 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
3076 -- address value is the same at the point of declaration of U_Ent and at
3077 -- the time of elaboration of the address clause.
3079 procedure Check_Expr_Constants (Nod : Node_Id);
3080 -- Checks that Nod meets the requirements for a constant address clause
3081 -- in the sense of the enclosing procedure.
3083 procedure Check_List_Constants (Lst : List_Id);
3084 -- Check that all elements of list Lst meet the requirements for a
3085 -- constant address clause in the sense of the enclosing procedure.
3087 -------------------------------
3088 -- Check_At_Constant_Address --
3089 -------------------------------
3091 procedure Check_At_Constant_Address (Nod : Node_Id) is
3093 if Is_Entity_Name (Nod) then
3094 if Present (Address_Clause (Entity ((Nod)))) then
3096 ("invalid address clause for initialized object &!",
3099 ("address for& cannot" &
3100 " depend on another address clause! (RM 13.1(22))!",
3103 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
3104 and then Sloc (U_Ent) < Sloc (Entity (Nod))
3107 ("invalid address clause for initialized object &!",
3109 Error_Msg_Node_2 := U_Ent;
3111 ("\& must be defined before & (RM 13.1(22))!",
3115 elsif Nkind (Nod) = N_Selected_Component then
3117 T : constant Entity_Id := Etype (Prefix (Nod));
3120 if (Is_Record_Type (T)
3121 and then Has_Discriminants (T))
3124 and then Is_Record_Type (Designated_Type (T))
3125 and then Has_Discriminants (Designated_Type (T)))
3128 ("invalid address clause for initialized object &!",
3131 ("\address cannot depend on component" &
3132 " of discriminated record (RM 13.1(22))!",
3135 Check_At_Constant_Address (Prefix (Nod));
3139 elsif Nkind (Nod) = N_Indexed_Component then
3140 Check_At_Constant_Address (Prefix (Nod));
3141 Check_List_Constants (Expressions (Nod));
3144 Check_Expr_Constants (Nod);
3146 end Check_At_Constant_Address;
3148 --------------------------
3149 -- Check_Expr_Constants --
3150 --------------------------
3152 procedure Check_Expr_Constants (Nod : Node_Id) is
3153 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
3154 Ent : Entity_Id := Empty;
3157 if Nkind (Nod) in N_Has_Etype
3158 and then Etype (Nod) = Any_Type
3164 when N_Empty | N_Error =>
3167 when N_Identifier | N_Expanded_Name =>
3168 Ent := Entity (Nod);
3170 -- We need to look at the original node if it is different
3171 -- from the node, since we may have rewritten things and
3172 -- substituted an identifier representing the rewrite.
3174 if Original_Node (Nod) /= Nod then
3175 Check_Expr_Constants (Original_Node (Nod));
3177 -- If the node is an object declaration without initial
3178 -- value, some code has been expanded, and the expression
3179 -- is not constant, even if the constituents might be
3180 -- acceptable, as in A'Address + offset.
3182 if Ekind (Ent) = E_Variable
3184 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3186 No (Expression (Declaration_Node (Ent)))
3189 ("invalid address clause for initialized object &!",
3192 -- If entity is constant, it may be the result of expanding
3193 -- a check. We must verify that its declaration appears
3194 -- before the object in question, else we also reject the
3197 elsif Ekind (Ent) = E_Constant
3198 and then In_Same_Source_Unit (Ent, U_Ent)
3199 and then Sloc (Ent) > Loc_U_Ent
3202 ("invalid address clause for initialized object &!",
3209 -- Otherwise look at the identifier and see if it is OK
3211 if Ekind (Ent) = E_Named_Integer
3213 Ekind (Ent) = E_Named_Real
3220 Ekind (Ent) = E_Constant
3222 Ekind (Ent) = E_In_Parameter
3224 -- This is the case where we must have Ent defined before
3225 -- U_Ent. Clearly if they are in different units this
3226 -- requirement is met since the unit containing Ent is
3227 -- already processed.
3229 if not In_Same_Source_Unit (Ent, U_Ent) then
3232 -- Otherwise location of Ent must be before the location
3233 -- of U_Ent, that's what prior defined means.
3235 elsif Sloc (Ent) < Loc_U_Ent then
3240 ("invalid address clause for initialized object &!",
3242 Error_Msg_Node_2 := U_Ent;
3244 ("\& must be defined before & (RM 13.1(22))!",
3248 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3249 Check_Expr_Constants (Original_Node (Nod));
3253 ("invalid address clause for initialized object &!",
3256 if Comes_From_Source (Ent) then
3258 ("\reference to variable& not allowed"
3259 & " (RM 13.1(22))!", Nod, Ent);
3262 ("non-static expression not allowed"
3263 & " (RM 13.1(22))!", Nod);
3267 when N_Integer_Literal =>
3269 -- If this is a rewritten unchecked conversion, in a system
3270 -- where Address is an integer type, always use the base type
3271 -- for a literal value. This is user-friendly and prevents
3272 -- order-of-elaboration issues with instances of unchecked
3275 if Nkind (Original_Node (Nod)) = N_Function_Call then
3276 Set_Etype (Nod, Base_Type (Etype (Nod)));
3279 when N_Real_Literal |
3281 N_Character_Literal =>
3285 Check_Expr_Constants (Low_Bound (Nod));
3286 Check_Expr_Constants (High_Bound (Nod));
3288 when N_Explicit_Dereference =>
3289 Check_Expr_Constants (Prefix (Nod));
3291 when N_Indexed_Component =>
3292 Check_Expr_Constants (Prefix (Nod));
3293 Check_List_Constants (Expressions (Nod));
3296 Check_Expr_Constants (Prefix (Nod));
3297 Check_Expr_Constants (Discrete_Range (Nod));
3299 when N_Selected_Component =>
3300 Check_Expr_Constants (Prefix (Nod));
3302 when N_Attribute_Reference =>
3303 if Attribute_Name (Nod) = Name_Address
3305 Attribute_Name (Nod) = Name_Access
3307 Attribute_Name (Nod) = Name_Unchecked_Access
3309 Attribute_Name (Nod) = Name_Unrestricted_Access
3311 Check_At_Constant_Address (Prefix (Nod));
3314 Check_Expr_Constants (Prefix (Nod));
3315 Check_List_Constants (Expressions (Nod));
3319 Check_List_Constants (Component_Associations (Nod));
3320 Check_List_Constants (Expressions (Nod));
3322 when N_Component_Association =>
3323 Check_Expr_Constants (Expression (Nod));
3325 when N_Extension_Aggregate =>
3326 Check_Expr_Constants (Ancestor_Part (Nod));
3327 Check_List_Constants (Component_Associations (Nod));
3328 Check_List_Constants (Expressions (Nod));
3333 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3334 Check_Expr_Constants (Left_Opnd (Nod));
3335 Check_Expr_Constants (Right_Opnd (Nod));
3338 Check_Expr_Constants (Right_Opnd (Nod));
3340 when N_Type_Conversion |
3341 N_Qualified_Expression |
3343 Check_Expr_Constants (Expression (Nod));
3345 when N_Unchecked_Type_Conversion =>
3346 Check_Expr_Constants (Expression (Nod));
3348 -- If this is a rewritten unchecked conversion, subtypes in
3349 -- this node are those created within the instance. To avoid
3350 -- order of elaboration issues, replace them with their base
3351 -- types. Note that address clauses can cause order of
3352 -- elaboration problems because they are elaborated by the
3353 -- back-end at the point of definition, and may mention
3354 -- entities declared in between (as long as everything is
3355 -- static). It is user-friendly to allow unchecked conversions
3358 if Nkind (Original_Node (Nod)) = N_Function_Call then
3359 Set_Etype (Expression (Nod),
3360 Base_Type (Etype (Expression (Nod))));
3361 Set_Etype (Nod, Base_Type (Etype (Nod)));
3364 when N_Function_Call =>
3365 if not Is_Pure (Entity (Name (Nod))) then
3367 ("invalid address clause for initialized object &!",
3371 ("\function & is not pure (RM 13.1(22))!",
3372 Nod, Entity (Name (Nod)));
3375 Check_List_Constants (Parameter_Associations (Nod));
3378 when N_Parameter_Association =>
3379 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3383 ("invalid address clause for initialized object &!",
3386 ("\must be constant defined before& (RM 13.1(22))!",
3389 end Check_Expr_Constants;
3391 --------------------------
3392 -- Check_List_Constants --
3393 --------------------------
3395 procedure Check_List_Constants (Lst : List_Id) is
3399 if Present (Lst) then
3400 Nod1 := First (Lst);
3401 while Present (Nod1) loop
3402 Check_Expr_Constants (Nod1);
3406 end Check_List_Constants;
3408 -- Start of processing for Check_Constant_Address_Clause
3411 Check_Expr_Constants (Expr);
3412 end Check_Constant_Address_Clause;
3418 procedure Check_Size
3422 Biased : out Boolean)
3424 UT : constant Entity_Id := Underlying_Type (T);
3430 -- Dismiss cases for generic types or types with previous errors
3433 or else UT = Any_Type
3434 or else Is_Generic_Type (UT)
3435 or else Is_Generic_Type (Root_Type (UT))
3439 -- Check case of bit packed array
3441 elsif Is_Array_Type (UT)
3442 and then Known_Static_Component_Size (UT)
3443 and then Is_Bit_Packed_Array (UT)
3451 Asiz := Component_Size (UT);
3452 Indx := First_Index (UT);
3454 Ityp := Etype (Indx);
3456 -- If non-static bound, then we are not in the business of
3457 -- trying to check the length, and indeed an error will be
3458 -- issued elsewhere, since sizes of non-static array types
3459 -- cannot be set implicitly or explicitly.
3461 if not Is_Static_Subtype (Ityp) then
3465 -- Otherwise accumulate next dimension
3467 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
3468 Expr_Value (Type_Low_Bound (Ityp)) +
3472 exit when No (Indx);
3478 Error_Msg_Uint_1 := Asiz;
3480 ("size for& too small, minimum allowed is ^", N, T);
3481 Set_Esize (T, Asiz);
3482 Set_RM_Size (T, Asiz);
3486 -- All other composite types are ignored
3488 elsif Is_Composite_Type (UT) then
3491 -- For fixed-point types, don't check minimum if type is not frozen,
3492 -- since we don't know all the characteristics of the type that can
3493 -- affect the size (e.g. a specified small) till freeze time.
3495 elsif Is_Fixed_Point_Type (UT)
3496 and then not Is_Frozen (UT)
3500 -- Cases for which a minimum check is required
3503 -- Ignore if specified size is correct for the type
3505 if Known_Esize (UT) and then Siz = Esize (UT) then
3509 -- Otherwise get minimum size
3511 M := UI_From_Int (Minimum_Size (UT));
3515 -- Size is less than minimum size, but one possibility remains
3516 -- that we can manage with the new size if we bias the type.
3518 M := UI_From_Int (Minimum_Size (UT, Biased => True));
3521 Error_Msg_Uint_1 := M;
3523 ("size for& too small, minimum allowed is ^", N, T);
3533 -------------------------
3534 -- Get_Alignment_Value --
3535 -------------------------
3537 function Get_Alignment_Value (Expr : Node_Id) return Uint is
3538 Align : constant Uint := Static_Integer (Expr);
3541 if Align = No_Uint then
3544 elsif Align <= 0 then
3545 Error_Msg_N ("alignment value must be positive", Expr);
3549 for J in Int range 0 .. 64 loop
3551 M : constant Uint := Uint_2 ** J;
3554 exit when M = Align;
3558 ("alignment value must be power of 2", Expr);
3566 end Get_Alignment_Value;
3572 procedure Initialize is
3574 Unchecked_Conversions.Init;
3577 -------------------------
3578 -- Is_Operational_Item --
3579 -------------------------
3581 function Is_Operational_Item (N : Node_Id) return Boolean is
3583 if Nkind (N) /= N_Attribute_Definition_Clause then
3587 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
3589 return Id = Attribute_Input
3590 or else Id = Attribute_Output
3591 or else Id = Attribute_Read
3592 or else Id = Attribute_Write
3593 or else Id = Attribute_External_Tag;
3596 end Is_Operational_Item;
3602 function Minimum_Size
3604 Biased : Boolean := False) return Nat
3606 Lo : Uint := No_Uint;
3607 Hi : Uint := No_Uint;
3608 LoR : Ureal := No_Ureal;
3609 HiR : Ureal := No_Ureal;
3610 LoSet : Boolean := False;
3611 HiSet : Boolean := False;
3615 R_Typ : constant Entity_Id := Root_Type (T);
3618 -- If bad type, return 0
3620 if T = Any_Type then
3623 -- For generic types, just return zero. There cannot be any legitimate
3624 -- need to know such a size, but this routine may be called with a
3625 -- generic type as part of normal processing.
3627 elsif Is_Generic_Type (R_Typ)
3628 or else R_Typ = Any_Type
3632 -- Access types. Normally an access type cannot have a size smaller
3633 -- than the size of System.Address. The exception is on VMS, where
3634 -- we have short and long addresses, and it is possible for an access
3635 -- type to have a short address size (and thus be less than the size
3636 -- of System.Address itself). We simply skip the check for VMS, and
3637 -- leave it to the back end to do the check.
3639 elsif Is_Access_Type (T) then
3640 if OpenVMS_On_Target then
3643 return System_Address_Size;
3646 -- Floating-point types
3648 elsif Is_Floating_Point_Type (T) then
3649 return UI_To_Int (Esize (R_Typ));
3653 elsif Is_Discrete_Type (T) then
3655 -- The following loop is looking for the nearest compile time known
3656 -- bounds following the ancestor subtype chain. The idea is to find
3657 -- the most restrictive known bounds information.
3661 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3666 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
3667 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
3674 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
3675 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
3681 Ancest := Ancestor_Subtype (Ancest);
3684 Ancest := Base_Type (T);
3686 if Is_Generic_Type (Ancest) then
3692 -- Fixed-point types. We can't simply use Expr_Value to get the
3693 -- Corresponding_Integer_Value values of the bounds, since these do not
3694 -- get set till the type is frozen, and this routine can be called
3695 -- before the type is frozen. Similarly the test for bounds being static
3696 -- needs to include the case where we have unanalyzed real literals for
3699 elsif Is_Fixed_Point_Type (T) then
3701 -- The following loop is looking for the nearest compile time known
3702 -- bounds following the ancestor subtype chain. The idea is to find
3703 -- the most restrictive known bounds information.
3707 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3711 -- Note: In the following two tests for LoSet and HiSet, it may
3712 -- seem redundant to test for N_Real_Literal here since normally
3713 -- one would assume that the test for the value being known at
3714 -- compile time includes this case. However, there is a glitch.
3715 -- If the real literal comes from folding a non-static expression,
3716 -- then we don't consider any non- static expression to be known
3717 -- at compile time if we are in configurable run time mode (needed
3718 -- in some cases to give a clearer definition of what is and what
3719 -- is not accepted). So the test is indeed needed. Without it, we
3720 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
3723 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
3724 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
3726 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
3733 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
3734 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
3736 HiR := Expr_Value_R (Type_High_Bound (Ancest));
3742 Ancest := Ancestor_Subtype (Ancest);
3745 Ancest := Base_Type (T);
3747 if Is_Generic_Type (Ancest) then
3753 Lo := UR_To_Uint (LoR / Small_Value (T));
3754 Hi := UR_To_Uint (HiR / Small_Value (T));
3756 -- No other types allowed
3759 raise Program_Error;
3762 -- Fall through with Hi and Lo set. Deal with biased case
3765 and then not Is_Fixed_Point_Type (T)
3766 and then not (Is_Enumeration_Type (T)
3767 and then Has_Non_Standard_Rep (T)))
3768 or else Has_Biased_Representation (T)
3774 -- Signed case. Note that we consider types like range 1 .. -1 to be
3775 -- signed for the purpose of computing the size, since the bounds have
3776 -- to be accommodated in the base type.
3778 if Lo < 0 or else Hi < 0 then
3782 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
3783 -- Note that we accommodate the case where the bounds cross. This
3784 -- can happen either because of the way the bounds are declared
3785 -- or because of the algorithm in Freeze_Fixed_Point_Type.
3799 -- If both bounds are positive, make sure that both are represen-
3800 -- table in the case where the bounds are crossed. This can happen
3801 -- either because of the way the bounds are declared, or because of
3802 -- the algorithm in Freeze_Fixed_Point_Type.
3808 -- S = size, (can accommodate 0 .. (2**size - 1))
3811 while Hi >= Uint_2 ** S loop
3819 ---------------------------
3820 -- New_Stream_Subprogram --
3821 ---------------------------
3823 procedure New_Stream_Subprogram
3827 Nam : TSS_Name_Type)
3829 Loc : constant Source_Ptr := Sloc (N);
3830 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
3831 Subp_Id : Entity_Id;
3832 Subp_Decl : Node_Id;
3836 Defer_Declaration : constant Boolean :=
3837 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
3838 -- For a tagged type, there is a declaration for each stream attribute
3839 -- at the freeze point, and we must generate only a completion of this
3840 -- declaration. We do the same for private types, because the full view
3841 -- might be tagged. Otherwise we generate a declaration at the point of
3842 -- the attribute definition clause.
3844 function Build_Spec return Node_Id;
3845 -- Used for declaration and renaming declaration, so that this is
3846 -- treated as a renaming_as_body.
3852 function Build_Spec return Node_Id is
3853 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
3856 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
3859 Subp_Id := Make_Defining_Identifier (Loc, Sname);
3861 -- S : access Root_Stream_Type'Class
3863 Formals := New_List (
3864 Make_Parameter_Specification (Loc,
3865 Defining_Identifier =>
3866 Make_Defining_Identifier (Loc, Name_S),
3868 Make_Access_Definition (Loc,
3871 Designated_Type (Etype (F)), Loc))));
3873 if Nam = TSS_Stream_Input then
3874 Spec := Make_Function_Specification (Loc,
3875 Defining_Unit_Name => Subp_Id,
3876 Parameter_Specifications => Formals,
3877 Result_Definition => T_Ref);
3882 Make_Parameter_Specification (Loc,
3883 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
3884 Out_Present => Out_P,
3885 Parameter_Type => T_Ref));
3887 Spec := Make_Procedure_Specification (Loc,
3888 Defining_Unit_Name => Subp_Id,
3889 Parameter_Specifications => Formals);
3895 -- Start of processing for New_Stream_Subprogram
3898 F := First_Formal (Subp);
3900 if Ekind (Subp) = E_Procedure then
3901 Etyp := Etype (Next_Formal (F));
3903 Etyp := Etype (Subp);
3906 -- Prepare subprogram declaration and insert it as an action on the
3907 -- clause node. The visibility for this entity is used to test for
3908 -- visibility of the attribute definition clause (in the sense of
3909 -- 8.3(23) as amended by AI-195).
3911 if not Defer_Declaration then
3913 Make_Subprogram_Declaration (Loc,
3914 Specification => Build_Spec);
3916 -- For a tagged type, there is always a visible declaration for each
3917 -- stream TSS (it is a predefined primitive operation), and the
3918 -- completion of this declaration occurs at the freeze point, which is
3919 -- not always visible at places where the attribute definition clause is
3920 -- visible. So, we create a dummy entity here for the purpose of
3921 -- tracking the visibility of the attribute definition clause itself.
3925 Make_Defining_Identifier (Loc,
3926 Chars => New_External_Name (Sname, 'V'));
3928 Make_Object_Declaration (Loc,
3929 Defining_Identifier => Subp_Id,
3930 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
3933 Insert_Action (N, Subp_Decl);
3934 Set_Entity (N, Subp_Id);
3937 Make_Subprogram_Renaming_Declaration (Loc,
3938 Specification => Build_Spec,
3939 Name => New_Reference_To (Subp, Loc));
3941 if Defer_Declaration then
3942 Set_TSS (Base_Type (Ent), Subp_Id);
3944 Insert_Action (N, Subp_Decl);
3945 Copy_TSS (Subp_Id, Base_Type (Ent));
3947 end New_Stream_Subprogram;
3949 ------------------------
3950 -- Rep_Item_Too_Early --
3951 ------------------------
3953 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
3955 -- Cannot apply non-operational rep items to generic types
3957 if Is_Operational_Item (N) then
3961 and then Is_Generic_Type (Root_Type (T))
3964 ("representation item not allowed for generic type", N);
3968 -- Otherwise check for incomplete type
3970 if Is_Incomplete_Or_Private_Type (T)
3971 and then No (Underlying_Type (T))
3974 ("representation item must be after full type declaration", N);
3977 -- If the type has incomplete components, a representation clause is
3978 -- illegal but stream attributes and Convention pragmas are correct.
3980 elsif Has_Private_Component (T) then
3981 if Nkind (N) = N_Pragma then
3985 ("representation item must appear after type is fully defined",
3992 end Rep_Item_Too_Early;
3994 -----------------------
3995 -- Rep_Item_Too_Late --
3996 -----------------------
3998 function Rep_Item_Too_Late
4001 FOnly : Boolean := False) return Boolean
4004 Parent_Type : Entity_Id;
4007 -- Output the too late message. Note that this is not considered a
4008 -- serious error, since the effect is simply that we ignore the
4009 -- representation clause in this case.
4015 procedure Too_Late is
4017 Error_Msg_N ("|representation item appears too late!", N);
4020 -- Start of processing for Rep_Item_Too_Late
4023 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
4024 -- types, which may be frozen if they appear in a representation clause
4025 -- for a local type.
4028 and then not From_With_Type (T)
4031 S := First_Subtype (T);
4033 if Present (Freeze_Node (S)) then
4035 ("?no more representation items for }", Freeze_Node (S), S);
4040 -- Check for case of non-tagged derived type whose parent either has
4041 -- primitive operations, or is a by reference type (RM 13.1(10)).
4045 and then Is_Derived_Type (T)
4046 and then not Is_Tagged_Type (T)
4048 Parent_Type := Etype (Base_Type (T));
4050 if Has_Primitive_Operations (Parent_Type) then
4053 ("primitive operations already defined for&!", N, Parent_Type);
4056 elsif Is_By_Reference_Type (Parent_Type) then
4059 ("parent type & is a by reference type!", N, Parent_Type);
4064 -- No error, link item into head of chain of rep items for the entity,
4065 -- but avoid chaining if we have an overloadable entity, and the pragma
4066 -- is one that can apply to multiple overloaded entities.
4068 if Is_Overloadable (T)
4069 and then Nkind (N) = N_Pragma
4072 Pname : constant Name_Id := Pragma_Name (N);
4074 if Pname = Name_Convention or else
4075 Pname = Name_Import or else
4076 Pname = Name_Export or else
4077 Pname = Name_External or else
4078 Pname = Name_Interface
4085 Record_Rep_Item (T, N);
4087 end Rep_Item_Too_Late;
4089 -------------------------
4090 -- Same_Representation --
4091 -------------------------
4093 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
4094 T1 : constant Entity_Id := Underlying_Type (Typ1);
4095 T2 : constant Entity_Id := Underlying_Type (Typ2);
4098 -- A quick check, if base types are the same, then we definitely have
4099 -- the same representation, because the subtype specific representation
4100 -- attributes (Size and Alignment) do not affect representation from
4101 -- the point of view of this test.
4103 if Base_Type (T1) = Base_Type (T2) then
4106 elsif Is_Private_Type (Base_Type (T2))
4107 and then Base_Type (T1) = Full_View (Base_Type (T2))
4112 -- Tagged types never have differing representations
4114 if Is_Tagged_Type (T1) then
4118 -- Representations are definitely different if conventions differ
4120 if Convention (T1) /= Convention (T2) then
4124 -- Representations are different if component alignments differ
4126 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4128 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4129 and then Component_Alignment (T1) /= Component_Alignment (T2)
4134 -- For arrays, the only real issue is component size. If we know the
4135 -- component size for both arrays, and it is the same, then that's
4136 -- good enough to know we don't have a change of representation.
4138 if Is_Array_Type (T1) then
4139 if Known_Component_Size (T1)
4140 and then Known_Component_Size (T2)
4141 and then Component_Size (T1) = Component_Size (T2)
4147 -- Types definitely have same representation if neither has non-standard
4148 -- representation since default representations are always consistent.
4149 -- If only one has non-standard representation, and the other does not,
4150 -- then we consider that they do not have the same representation. They
4151 -- might, but there is no way of telling early enough.
4153 if Has_Non_Standard_Rep (T1) then
4154 if not Has_Non_Standard_Rep (T2) then
4158 return not Has_Non_Standard_Rep (T2);
4161 -- Here the two types both have non-standard representation, and we need
4162 -- to determine if they have the same non-standard representation.
4164 -- For arrays, we simply need to test if the component sizes are the
4165 -- same. Pragma Pack is reflected in modified component sizes, so this
4166 -- check also deals with pragma Pack.
4168 if Is_Array_Type (T1) then
4169 return Component_Size (T1) = Component_Size (T2);
4171 -- Tagged types always have the same representation, because it is not
4172 -- possible to specify different representations for common fields.
4174 elsif Is_Tagged_Type (T1) then
4177 -- Case of record types
4179 elsif Is_Record_Type (T1) then
4181 -- Packed status must conform
4183 if Is_Packed (T1) /= Is_Packed (T2) then
4186 -- Otherwise we must check components. Typ2 maybe a constrained
4187 -- subtype with fewer components, so we compare the components
4188 -- of the base types.
4191 Record_Case : declare
4192 CD1, CD2 : Entity_Id;
4194 function Same_Rep return Boolean;
4195 -- CD1 and CD2 are either components or discriminants. This
4196 -- function tests whether the two have the same representation
4202 function Same_Rep return Boolean is
4204 if No (Component_Clause (CD1)) then
4205 return No (Component_Clause (CD2));
4209 Present (Component_Clause (CD2))
4211 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4213 Esize (CD1) = Esize (CD2);
4217 -- Start of processing for Record_Case
4220 if Has_Discriminants (T1) then
4221 CD1 := First_Discriminant (T1);
4222 CD2 := First_Discriminant (T2);
4224 -- The number of discriminants may be different if the
4225 -- derived type has fewer (constrained by values). The
4226 -- invisible discriminants retain the representation of
4227 -- the original, so the discrepancy does not per se
4228 -- indicate a different representation.
4231 and then Present (CD2)
4233 if not Same_Rep then
4236 Next_Discriminant (CD1);
4237 Next_Discriminant (CD2);
4242 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4243 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4245 while Present (CD1) loop
4246 if not Same_Rep then
4249 Next_Component (CD1);
4250 Next_Component (CD2);
4258 -- For enumeration types, we must check each literal to see if the
4259 -- representation is the same. Note that we do not permit enumeration
4260 -- representation clauses for Character and Wide_Character, so these
4261 -- cases were already dealt with.
4263 elsif Is_Enumeration_Type (T1) then
4265 Enumeration_Case : declare
4269 L1 := First_Literal (T1);
4270 L2 := First_Literal (T2);
4272 while Present (L1) loop
4273 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4283 end Enumeration_Case;
4285 -- Any other types have the same representation for these purposes
4290 end Same_Representation;
4292 --------------------
4293 -- Set_Enum_Esize --
4294 --------------------
4296 procedure Set_Enum_Esize (T : Entity_Id) is
4304 -- Find the minimum standard size (8,16,32,64) that fits
4306 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4307 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4310 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4311 Sz := Standard_Character_Size; -- May be > 8 on some targets
4313 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4316 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4319 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4324 if Hi < Uint_2**08 then
4325 Sz := Standard_Character_Size; -- May be > 8 on some targets
4327 elsif Hi < Uint_2**16 then
4330 elsif Hi < Uint_2**32 then
4333 else pragma Assert (Hi < Uint_2**63);
4338 -- That minimum is the proper size unless we have a foreign convention
4339 -- and the size required is 32 or less, in which case we bump the size
4340 -- up to 32. This is required for C and C++ and seems reasonable for
4341 -- all other foreign conventions.
4343 if Has_Foreign_Convention (T)
4344 and then Esize (T) < Standard_Integer_Size
4346 Init_Esize (T, Standard_Integer_Size);
4352 ------------------------------
4353 -- Validate_Address_Clauses --
4354 ------------------------------
4356 procedure Validate_Address_Clauses is
4358 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4360 ACCR : Address_Clause_Check_Record
4361 renames Address_Clause_Checks.Table (J);
4372 -- Skip processing of this entry if warning already posted
4374 if not Address_Warning_Posted (ACCR.N) then
4376 Expr := Original_Node (Expression (ACCR.N));
4380 X_Alignment := Alignment (ACCR.X);
4381 Y_Alignment := Alignment (ACCR.Y);
4383 -- Similarly obtain sizes
4385 X_Size := Esize (ACCR.X);
4386 Y_Size := Esize (ACCR.Y);
4388 -- Check for large object overlaying smaller one
4391 and then X_Size > Uint_0
4392 and then X_Size > Y_Size
4395 ("?& overlays smaller object", ACCR.N, ACCR.X);
4397 ("\?program execution may be erroneous", ACCR.N);
4398 Error_Msg_Uint_1 := X_Size;
4400 ("\?size of & is ^", ACCR.N, ACCR.X);
4401 Error_Msg_Uint_1 := Y_Size;
4403 ("\?size of & is ^", ACCR.N, ACCR.Y);
4405 -- Check for inadequate alignment, both of the base object
4406 -- and of the offset, if any.
4408 -- Note: we do not check the alignment if we gave a size
4409 -- warning, since it would likely be redundant.
4411 elsif Y_Alignment /= Uint_0
4412 and then (Y_Alignment < X_Alignment
4415 Nkind (Expr) = N_Attribute_Reference
4417 Attribute_Name (Expr) = Name_Address
4419 Has_Compatible_Alignment
4420 (ACCR.X, Prefix (Expr))
4421 /= Known_Compatible))
4424 ("?specified address for& may be inconsistent "
4428 ("\?program execution may be erroneous (RM 13.3(27))",
4430 Error_Msg_Uint_1 := X_Alignment;
4432 ("\?alignment of & is ^",
4434 Error_Msg_Uint_1 := Y_Alignment;
4436 ("\?alignment of & is ^",
4438 if Y_Alignment >= X_Alignment then
4440 ("\?but offset is not multiple of alignment",
4447 end Validate_Address_Clauses;
4449 -----------------------------------
4450 -- Validate_Unchecked_Conversion --
4451 -----------------------------------
4453 procedure Validate_Unchecked_Conversion
4455 Act_Unit : Entity_Id)
4462 -- Obtain source and target types. Note that we call Ancestor_Subtype
4463 -- here because the processing for generic instantiation always makes
4464 -- subtypes, and we want the original frozen actual types.
4466 -- If we are dealing with private types, then do the check on their
4467 -- fully declared counterparts if the full declarations have been
4468 -- encountered (they don't have to be visible, but they must exist!)
4470 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
4472 if Is_Private_Type (Source)
4473 and then Present (Underlying_Type (Source))
4475 Source := Underlying_Type (Source);
4478 Target := Ancestor_Subtype (Etype (Act_Unit));
4480 -- If either type is generic, the instantiation happens within a generic
4481 -- unit, and there is nothing to check. The proper check
4482 -- will happen when the enclosing generic is instantiated.
4484 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
4488 if Is_Private_Type (Target)
4489 and then Present (Underlying_Type (Target))
4491 Target := Underlying_Type (Target);
4494 -- Source may be unconstrained array, but not target
4496 if Is_Array_Type (Target)
4497 and then not Is_Constrained (Target)
4500 ("unchecked conversion to unconstrained array not allowed", N);
4504 -- Warn if conversion between two different convention pointers
4506 if Is_Access_Type (Target)
4507 and then Is_Access_Type (Source)
4508 and then Convention (Target) /= Convention (Source)
4509 and then Warn_On_Unchecked_Conversion
4511 -- Give warnings for subprogram pointers only on most targets. The
4512 -- exception is VMS, where data pointers can have different lengths
4513 -- depending on the pointer convention.
4515 if Is_Access_Subprogram_Type (Target)
4516 or else Is_Access_Subprogram_Type (Source)
4517 or else OpenVMS_On_Target
4520 ("?conversion between pointers with different conventions!", N);
4524 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4525 -- warning when compiling GNAT-related sources.
4527 if Warn_On_Unchecked_Conversion
4528 and then not In_Predefined_Unit (N)
4529 and then RTU_Loaded (Ada_Calendar)
4531 (Chars (Source) = Name_Time
4533 Chars (Target) = Name_Time)
4535 -- If Ada.Calendar is loaded and the name of one of the operands is
4536 -- Time, there is a good chance that this is Ada.Calendar.Time.
4539 Calendar_Time : constant Entity_Id :=
4540 Full_View (RTE (RO_CA_Time));
4542 pragma Assert (Present (Calendar_Time));
4544 if Source = Calendar_Time
4545 or else Target = Calendar_Time
4548 ("?representation of 'Time values may change between " &
4549 "'G'N'A'T versions", N);
4554 -- Make entry in unchecked conversion table for later processing by
4555 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4556 -- (using values set by the back-end where possible). This is only done
4557 -- if the appropriate warning is active.
4559 if Warn_On_Unchecked_Conversion then
4560 Unchecked_Conversions.Append
4561 (New_Val => UC_Entry'
4566 -- If both sizes are known statically now, then back end annotation
4567 -- is not required to do a proper check but if either size is not
4568 -- known statically, then we need the annotation.
4570 if Known_Static_RM_Size (Source)
4571 and then Known_Static_RM_Size (Target)
4575 Back_Annotate_Rep_Info := True;
4579 -- If unchecked conversion to access type, and access type is declared
4580 -- in the same unit as the unchecked conversion, then set the
4581 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4584 if Is_Access_Type (Target) and then
4585 In_Same_Source_Unit (Target, N)
4587 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4590 -- Generate N_Validate_Unchecked_Conversion node for back end in
4591 -- case the back end needs to perform special validation checks.
4593 -- Shouldn't this be in Exp_Ch13, since the check only gets done
4594 -- if we have full expansion and the back end is called ???
4597 Make_Validate_Unchecked_Conversion (Sloc (N));
4598 Set_Source_Type (Vnode, Source);
4599 Set_Target_Type (Vnode, Target);
4601 -- If the unchecked conversion node is in a list, just insert before it.
4602 -- If not we have some strange case, not worth bothering about.
4604 if Is_List_Member (N) then
4605 Insert_After (N, Vnode);
4607 end Validate_Unchecked_Conversion;
4609 ------------------------------------
4610 -- Validate_Unchecked_Conversions --
4611 ------------------------------------
4613 procedure Validate_Unchecked_Conversions is
4615 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4617 T : UC_Entry renames Unchecked_Conversions.Table (N);
4619 Eloc : constant Source_Ptr := T.Eloc;
4620 Source : constant Entity_Id := T.Source;
4621 Target : constant Entity_Id := T.Target;
4627 -- This validation check, which warns if we have unequal sizes for
4628 -- unchecked conversion, and thus potentially implementation
4629 -- dependent semantics, is one of the few occasions on which we
4630 -- use the official RM size instead of Esize. See description in
4631 -- Einfo "Handling of Type'Size Values" for details.
4633 if Serious_Errors_Detected = 0
4634 and then Known_Static_RM_Size (Source)
4635 and then Known_Static_RM_Size (Target)
4637 -- Don't do the check if warnings off for either type, note the
4638 -- deliberate use of OR here instead of OR ELSE to get the flag
4639 -- Warnings_Off_Used set for both types if appropriate.
4641 and then not (Has_Warnings_Off (Source)
4643 Has_Warnings_Off (Target))
4645 Source_Siz := RM_Size (Source);
4646 Target_Siz := RM_Size (Target);
4648 if Source_Siz /= Target_Siz then
4650 ("?types for unchecked conversion have different sizes!",
4653 if All_Errors_Mode then
4654 Error_Msg_Name_1 := Chars (Source);
4655 Error_Msg_Uint_1 := Source_Siz;
4656 Error_Msg_Name_2 := Chars (Target);
4657 Error_Msg_Uint_2 := Target_Siz;
4658 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
4660 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4662 if Is_Discrete_Type (Source)
4663 and then Is_Discrete_Type (Target)
4665 if Source_Siz > Target_Siz then
4667 ("\?^ high order bits of source will be ignored!",
4670 elsif Is_Unsigned_Type (Source) then
4672 ("\?source will be extended with ^ high order " &
4673 "zero bits?!", Eloc);
4677 ("\?source will be extended with ^ high order " &
4682 elsif Source_Siz < Target_Siz then
4683 if Is_Discrete_Type (Target) then
4684 if Bytes_Big_Endian then
4686 ("\?target value will include ^ undefined " &
4691 ("\?target value will include ^ undefined " &
4698 ("\?^ trailing bits of target value will be " &
4699 "undefined!", Eloc);
4702 else pragma Assert (Source_Siz > Target_Siz);
4704 ("\?^ trailing bits of source will be ignored!",
4711 -- If both types are access types, we need to check the alignment.
4712 -- If the alignment of both is specified, we can do it here.
4714 if Serious_Errors_Detected = 0
4715 and then Ekind (Source) in Access_Kind
4716 and then Ekind (Target) in Access_Kind
4717 and then Target_Strict_Alignment
4718 and then Present (Designated_Type (Source))
4719 and then Present (Designated_Type (Target))
4722 D_Source : constant Entity_Id := Designated_Type (Source);
4723 D_Target : constant Entity_Id := Designated_Type (Target);
4726 if Known_Alignment (D_Source)
4727 and then Known_Alignment (D_Target)
4730 Source_Align : constant Uint := Alignment (D_Source);
4731 Target_Align : constant Uint := Alignment (D_Target);
4734 if Source_Align < Target_Align
4735 and then not Is_Tagged_Type (D_Source)
4737 -- Suppress warning if warnings suppressed on either
4738 -- type or either designated type. Note the use of
4739 -- OR here instead of OR ELSE. That is intentional,
4740 -- we would like to set flag Warnings_Off_Used in
4741 -- all types for which warnings are suppressed.
4743 and then not (Has_Warnings_Off (D_Source)
4745 Has_Warnings_Off (D_Target)
4747 Has_Warnings_Off (Source)
4749 Has_Warnings_Off (Target))
4751 Error_Msg_Uint_1 := Target_Align;
4752 Error_Msg_Uint_2 := Source_Align;
4753 Error_Msg_Node_1 := D_Target;
4754 Error_Msg_Node_2 := D_Source;
4756 ("?alignment of & (^) is stricter than " &
4757 "alignment of & (^)!", Eloc);
4759 ("\?resulting access value may have invalid " &
4760 "alignment!", Eloc);
4768 end Validate_Unchecked_Conversions;