1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Elists; use Elists;
30 with Errout; use Errout;
31 with Exp_Disp; use Exp_Disp;
32 with Exp_Tss; use Exp_Tss;
33 with Exp_Util; use Exp_Util;
35 with Lib.Xref; use Lib.Xref;
36 with Namet; use Namet;
37 with Nlists; use Nlists;
38 with Nmake; use Nmake;
40 with Restrict; use Restrict;
41 with Rident; use Rident;
42 with Rtsfind; use Rtsfind;
44 with Sem_Aux; use Sem_Aux;
45 with Sem_Ch3; use Sem_Ch3;
46 with Sem_Ch8; use Sem_Ch8;
47 with Sem_Eval; use Sem_Eval;
48 with Sem_Res; use Sem_Res;
49 with Sem_Type; use Sem_Type;
50 with Sem_Util; use Sem_Util;
51 with Sem_Warn; use Sem_Warn;
52 with Snames; use Snames;
53 with Stand; use Stand;
54 with Sinfo; use Sinfo;
56 with Targparm; use Targparm;
57 with Ttypes; use Ttypes;
58 with Tbuild; use Tbuild;
59 with Urealp; use Urealp;
61 with GNAT.Heap_Sort_G;
63 package body Sem_Ch13 is
65 SSU : constant Pos := System_Storage_Unit;
66 -- Convenient short hand for commonly used constant
68 -----------------------
69 -- Local Subprograms --
70 -----------------------
72 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
73 -- This routine is called after setting the Esize of type entity Typ.
74 -- The purpose is to deal with the situation where an alignment has been
75 -- inherited from a derived type that is no longer appropriate for the
76 -- new Esize value. In this case, we reset the Alignment to unknown.
78 function Get_Alignment_Value (Expr : Node_Id) return Uint;
79 -- Given the expression for an alignment value, returns the corresponding
80 -- Uint value. If the value is inappropriate, then error messages are
81 -- posted as required, and a value of No_Uint is returned.
83 function Is_Operational_Item (N : Node_Id) return Boolean;
84 -- A specification for a stream attribute is allowed before the full
85 -- type is declared, as explained in AI-00137 and the corrigendum.
86 -- Attributes that do not specify a representation characteristic are
87 -- operational attributes.
89 procedure New_Stream_Subprogram
94 -- Create a subprogram renaming of a given stream attribute to the
95 -- designated subprogram and then in the tagged case, provide this as a
96 -- primitive operation, or in the non-tagged case make an appropriate TSS
97 -- entry. This is more properly an expansion activity than just semantics,
98 -- but the presence of user-defined stream functions for limited types is a
99 -- legality check, which is why this takes place here rather than in
100 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
101 -- function to be generated.
103 -- To avoid elaboration anomalies with freeze nodes, for untagged types
104 -- we generate both a subprogram declaration and a subprogram renaming
105 -- declaration, so that the attribute specification is handled as a
106 -- renaming_as_body. For tagged types, the specification is one of the
109 ----------------------------------------------
110 -- Table for Validate_Unchecked_Conversions --
111 ----------------------------------------------
113 -- The following table collects unchecked conversions for validation.
114 -- Entries are made by Validate_Unchecked_Conversion and then the
115 -- call to Validate_Unchecked_Conversions does the actual error
116 -- checking and posting of warnings. The reason for this delayed
117 -- processing is to take advantage of back-annotations of size and
118 -- alignment values performed by the back end.
120 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
121 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
122 -- will already have modified all Sloc values if the -gnatD option is set.
124 type UC_Entry is record
125 Eloc : Source_Ptr; -- node used for posting warnings
126 Source : Entity_Id; -- source type for unchecked conversion
127 Target : Entity_Id; -- target type for unchecked conversion
130 package Unchecked_Conversions is new Table.Table (
131 Table_Component_Type => UC_Entry,
132 Table_Index_Type => Int,
133 Table_Low_Bound => 1,
135 Table_Increment => 200,
136 Table_Name => "Unchecked_Conversions");
138 ----------------------------------------
139 -- Table for Validate_Address_Clauses --
140 ----------------------------------------
142 -- If an address clause has the form
144 -- for X'Address use Expr
146 -- where Expr is of the form Y'Address or recursively is a reference
147 -- to a constant of either of these forms, and X and Y are entities of
148 -- objects, then if Y has a smaller alignment than X, that merits a
149 -- warning about possible bad alignment. The following table collects
150 -- address clauses of this kind. We put these in a table so that they
151 -- can be checked after the back end has completed annotation of the
152 -- alignments of objects, since we can catch more cases that way.
154 type Address_Clause_Check_Record is record
156 -- The address clause
159 -- The entity of the object overlaying Y
162 -- The entity of the object being overlaid
165 -- Whether the address is offseted within Y
168 package Address_Clause_Checks is new Table.Table (
169 Table_Component_Type => Address_Clause_Check_Record,
170 Table_Index_Type => Int,
171 Table_Low_Bound => 1,
173 Table_Increment => 200,
174 Table_Name => "Address_Clause_Checks");
176 -----------------------------------------
177 -- Adjust_Record_For_Reverse_Bit_Order --
178 -----------------------------------------
180 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
185 -- Processing depends on version of Ada
187 -- For Ada 95, we just renumber bits within a storage unit. We do the
188 -- same for Ada 83 mode, since we recognize pragma Bit_Order in Ada 83,
189 -- and are free to add this extension.
191 if Ada_Version < Ada_2005 then
192 Comp := First_Component_Or_Discriminant (R);
193 while Present (Comp) loop
194 CC := Component_Clause (Comp);
196 -- If component clause is present, then deal with the non-default
197 -- bit order case for Ada 95 mode.
199 -- We only do this processing for the base type, and in fact that
200 -- is important, since otherwise if there are record subtypes, we
201 -- could reverse the bits once for each subtype, which is wrong.
204 and then Ekind (R) = E_Record_Type
207 CFB : constant Uint := Component_Bit_Offset (Comp);
208 CSZ : constant Uint := Esize (Comp);
209 CLC : constant Node_Id := Component_Clause (Comp);
210 Pos : constant Node_Id := Position (CLC);
211 FB : constant Node_Id := First_Bit (CLC);
213 Storage_Unit_Offset : constant Uint :=
214 CFB / System_Storage_Unit;
216 Start_Bit : constant Uint :=
217 CFB mod System_Storage_Unit;
220 -- Cases where field goes over storage unit boundary
222 if Start_Bit + CSZ > System_Storage_Unit then
224 -- Allow multi-byte field but generate warning
226 if Start_Bit mod System_Storage_Unit = 0
227 and then CSZ mod System_Storage_Unit = 0
230 ("multi-byte field specified with non-standard"
231 & " Bit_Order?", CLC);
233 if Bytes_Big_Endian then
235 ("bytes are not reversed "
236 & "(component is big-endian)?", CLC);
239 ("bytes are not reversed "
240 & "(component is little-endian)?", CLC);
243 -- Do not allow non-contiguous field
247 ("attempt to specify non-contiguous field "
248 & "not permitted", CLC);
250 ("\caused by non-standard Bit_Order "
253 ("\consider possibility of using "
254 & "Ada 2005 mode here", CLC);
257 -- Case where field fits in one storage unit
260 -- Give warning if suspicious component clause
262 if Intval (FB) >= System_Storage_Unit
263 and then Warn_On_Reverse_Bit_Order
266 ("?Bit_Order clause does not affect " &
267 "byte ordering", Pos);
269 Intval (Pos) + Intval (FB) /
272 ("?position normalized to ^ before bit " &
273 "order interpreted", Pos);
276 -- Here is where we fix up the Component_Bit_Offset value
277 -- to account for the reverse bit order. Some examples of
278 -- what needs to be done are:
280 -- First_Bit .. Last_Bit Component_Bit_Offset
292 -- The rule is that the first bit is is obtained by
293 -- subtracting the old ending bit from storage_unit - 1.
295 Set_Component_Bit_Offset
297 (Storage_Unit_Offset * System_Storage_Unit) +
298 (System_Storage_Unit - 1) -
299 (Start_Bit + CSZ - 1));
301 Set_Normalized_First_Bit
303 Component_Bit_Offset (Comp) mod
304 System_Storage_Unit);
309 Next_Component_Or_Discriminant (Comp);
312 -- For Ada 2005, we do machine scalar processing, as fully described In
313 -- AI-133. This involves gathering all components which start at the
314 -- same byte offset and processing them together. Same approach is still
315 -- valid in later versions including Ada 2012.
319 Max_Machine_Scalar_Size : constant Uint :=
321 (Standard_Long_Long_Integer_Size);
322 -- We use this as the maximum machine scalar size
325 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
328 -- This first loop through components does two things. First it
329 -- deals with the case of components with component clauses whose
330 -- length is greater than the maximum machine scalar size (either
331 -- accepting them or rejecting as needed). Second, it counts the
332 -- number of components with component clauses whose length does
333 -- not exceed this maximum for later processing.
336 Comp := First_Component_Or_Discriminant (R);
337 while Present (Comp) loop
338 CC := Component_Clause (Comp);
342 Fbit : constant Uint :=
343 Static_Integer (First_Bit (CC));
346 -- Case of component with size > max machine scalar
348 if Esize (Comp) > Max_Machine_Scalar_Size then
350 -- Must begin on byte boundary
352 if Fbit mod SSU /= 0 then
354 ("illegal first bit value for "
355 & "reverse bit order",
357 Error_Msg_Uint_1 := SSU;
358 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
361 ("\must be a multiple of ^ "
362 & "if size greater than ^",
365 -- Must end on byte boundary
367 elsif Esize (Comp) mod SSU /= 0 then
369 ("illegal last bit value for "
370 & "reverse bit order",
372 Error_Msg_Uint_1 := SSU;
373 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
376 ("\must be a multiple of ^ if size "
380 -- OK, give warning if enabled
382 elsif Warn_On_Reverse_Bit_Order then
384 ("multi-byte field specified with "
385 & " non-standard Bit_Order?", CC);
387 if Bytes_Big_Endian then
389 ("\bytes are not reversed "
390 & "(component is big-endian)?", CC);
393 ("\bytes are not reversed "
394 & "(component is little-endian)?", CC);
398 -- Case where size is not greater than max machine
399 -- scalar. For now, we just count these.
402 Num_CC := Num_CC + 1;
407 Next_Component_Or_Discriminant (Comp);
410 -- We need to sort the component clauses on the basis of the
411 -- Position values in the clause, so we can group clauses with
412 -- the same Position. together to determine the relevant machine
416 Comps : array (0 .. Num_CC) of Entity_Id;
417 -- Array to collect component and discriminant entities. The
418 -- data starts at index 1, the 0'th entry is for the sort
421 function CP_Lt (Op1, Op2 : Natural) return Boolean;
422 -- Compare routine for Sort
424 procedure CP_Move (From : Natural; To : Natural);
425 -- Move routine for Sort
427 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
431 -- Start and stop positions in the component list of the set of
432 -- components with the same starting position (that constitute
433 -- components in a single machine scalar).
436 -- Maximum last bit value of any component in this set
439 -- Corresponding machine scalar size
445 function CP_Lt (Op1, Op2 : Natural) return Boolean is
447 return Position (Component_Clause (Comps (Op1))) <
448 Position (Component_Clause (Comps (Op2)));
455 procedure CP_Move (From : Natural; To : Natural) is
457 Comps (To) := Comps (From);
460 -- Start of processing for Sort_CC
463 -- Collect the component clauses
466 Comp := First_Component_Or_Discriminant (R);
467 while Present (Comp) loop
468 if Present (Component_Clause (Comp))
469 and then Esize (Comp) <= Max_Machine_Scalar_Size
471 Num_CC := Num_CC + 1;
472 Comps (Num_CC) := Comp;
475 Next_Component_Or_Discriminant (Comp);
478 -- Sort by ascending position number
480 Sorting.Sort (Num_CC);
482 -- We now have all the components whose size does not exceed
483 -- the max machine scalar value, sorted by starting position.
484 -- In this loop we gather groups of clauses starting at the
485 -- same position, to process them in accordance with AI-133.
488 while Stop < Num_CC loop
493 (Last_Bit (Component_Clause (Comps (Start))));
494 while Stop < Num_CC loop
496 (Position (Component_Clause (Comps (Stop + 1)))) =
498 (Position (Component_Clause (Comps (Stop))))
506 (Component_Clause (Comps (Stop)))));
512 -- Now we have a group of component clauses from Start to
513 -- Stop whose positions are identical, and MaxL is the
514 -- maximum last bit value of any of these components.
516 -- We need to determine the corresponding machine scalar
517 -- size. This loop assumes that machine scalar sizes are
518 -- even, and that each possible machine scalar has twice
519 -- as many bits as the next smaller one.
521 MSS := Max_Machine_Scalar_Size;
523 and then (MSS / 2) >= SSU
524 and then (MSS / 2) > MaxL
529 -- Here is where we fix up the Component_Bit_Offset value
530 -- to account for the reverse bit order. Some examples of
531 -- what needs to be done for the case of a machine scalar
534 -- First_Bit .. Last_Bit Component_Bit_Offset
546 -- The rule is that the first bit is obtained by subtracting
547 -- the old ending bit from machine scalar size - 1.
549 for C in Start .. Stop loop
551 Comp : constant Entity_Id := Comps (C);
552 CC : constant Node_Id :=
553 Component_Clause (Comp);
554 LB : constant Uint :=
555 Static_Integer (Last_Bit (CC));
556 NFB : constant Uint := MSS - Uint_1 - LB;
557 NLB : constant Uint := NFB + Esize (Comp) - 1;
558 Pos : constant Uint :=
559 Static_Integer (Position (CC));
562 if Warn_On_Reverse_Bit_Order then
563 Error_Msg_Uint_1 := MSS;
565 ("info: reverse bit order in machine " &
566 "scalar of length^?", First_Bit (CC));
567 Error_Msg_Uint_1 := NFB;
568 Error_Msg_Uint_2 := NLB;
570 if Bytes_Big_Endian then
572 ("?\info: big-endian range for "
573 & "component & is ^ .. ^",
574 First_Bit (CC), Comp);
577 ("?\info: little-endian range "
578 & "for component & is ^ .. ^",
579 First_Bit (CC), Comp);
583 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
584 Set_Normalized_First_Bit (Comp, NFB mod SSU);
591 end Adjust_Record_For_Reverse_Bit_Order;
593 --------------------------------------
594 -- Alignment_Check_For_Esize_Change --
595 --------------------------------------
597 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
599 -- If the alignment is known, and not set by a rep clause, and is
600 -- inconsistent with the size being set, then reset it to unknown,
601 -- we assume in this case that the size overrides the inherited
602 -- alignment, and that the alignment must be recomputed.
604 if Known_Alignment (Typ)
605 and then not Has_Alignment_Clause (Typ)
606 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
608 Init_Alignment (Typ);
610 end Alignment_Check_For_Esize_Change;
612 -----------------------
613 -- Analyze_At_Clause --
614 -----------------------
616 -- An at clause is replaced by the corresponding Address attribute
617 -- definition clause that is the preferred approach in Ada 95.
619 procedure Analyze_At_Clause (N : Node_Id) is
620 CS : constant Boolean := Comes_From_Source (N);
623 -- This is an obsolescent feature
625 Check_Restriction (No_Obsolescent_Features, N);
627 if Warn_On_Obsolescent_Feature then
629 ("at clause is an obsolescent feature (RM J.7(2))?", N);
631 ("\use address attribute definition clause instead?", N);
634 -- Rewrite as address clause
637 Make_Attribute_Definition_Clause (Sloc (N),
638 Name => Identifier (N),
639 Chars => Name_Address,
640 Expression => Expression (N)));
642 -- We preserve Comes_From_Source, since logically the clause still
643 -- comes from the source program even though it is changed in form.
645 Set_Comes_From_Source (N, CS);
647 -- Analyze rewritten clause
649 Analyze_Attribute_Definition_Clause (N);
650 end Analyze_At_Clause;
652 -----------------------------------------
653 -- Analyze_Attribute_Definition_Clause --
654 -----------------------------------------
656 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
657 Loc : constant Source_Ptr := Sloc (N);
658 Nam : constant Node_Id := Name (N);
659 Attr : constant Name_Id := Chars (N);
660 Expr : constant Node_Id := Expression (N);
661 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
665 FOnly : Boolean := False;
666 -- Reset to True for subtype specific attribute (Alignment, Size)
667 -- and for stream attributes, i.e. those cases where in the call
668 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
669 -- rules are checked. Note that the case of stream attributes is not
670 -- clear from the RM, but see AI95-00137. Also, the RM seems to
671 -- disallow Storage_Size for derived task types, but that is also
672 -- clearly unintentional.
674 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
675 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
676 -- definition clauses.
678 -----------------------------------
679 -- Analyze_Stream_TSS_Definition --
680 -----------------------------------
682 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
683 Subp : Entity_Id := Empty;
688 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
690 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
691 -- Return true if the entity is a subprogram with an appropriate
692 -- profile for the attribute being defined.
694 ----------------------
695 -- Has_Good_Profile --
696 ----------------------
698 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
700 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
701 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
702 (False => E_Procedure, True => E_Function);
706 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
710 F := First_Formal (Subp);
713 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
714 or else Designated_Type (Etype (F)) /=
715 Class_Wide_Type (RTE (RE_Root_Stream_Type))
720 if not Is_Function then
724 Expected_Mode : constant array (Boolean) of Entity_Kind :=
725 (False => E_In_Parameter,
726 True => E_Out_Parameter);
728 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
739 return Base_Type (Typ) = Base_Type (Ent)
740 and then No (Next_Formal (F));
741 end Has_Good_Profile;
743 -- Start of processing for Analyze_Stream_TSS_Definition
748 if not Is_Type (U_Ent) then
749 Error_Msg_N ("local name must be a subtype", Nam);
753 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
755 -- If Pnam is present, it can be either inherited from an ancestor
756 -- type (in which case it is legal to redefine it for this type), or
757 -- be a previous definition of the attribute for the same type (in
758 -- which case it is illegal).
760 -- In the first case, it will have been analyzed already, and we
761 -- can check that its profile does not match the expected profile
762 -- for a stream attribute of U_Ent. In the second case, either Pnam
763 -- has been analyzed (and has the expected profile), or it has not
764 -- been analyzed yet (case of a type that has not been frozen yet
765 -- and for which the stream attribute has been set using Set_TSS).
768 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
770 Error_Msg_Sloc := Sloc (Pnam);
771 Error_Msg_Name_1 := Attr;
772 Error_Msg_N ("% attribute already defined #", Nam);
778 if Is_Entity_Name (Expr) then
779 if not Is_Overloaded (Expr) then
780 if Has_Good_Profile (Entity (Expr)) then
781 Subp := Entity (Expr);
785 Get_First_Interp (Expr, I, It);
786 while Present (It.Nam) loop
787 if Has_Good_Profile (It.Nam) then
792 Get_Next_Interp (I, It);
797 if Present (Subp) then
798 if Is_Abstract_Subprogram (Subp) then
799 Error_Msg_N ("stream subprogram must not be abstract", Expr);
803 Set_Entity (Expr, Subp);
804 Set_Etype (Expr, Etype (Subp));
806 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
809 Error_Msg_Name_1 := Attr;
810 Error_Msg_N ("incorrect expression for% attribute", Expr);
812 end Analyze_Stream_TSS_Definition;
814 -- Start of processing for Analyze_Attribute_Definition_Clause
817 -- Process Ignore_Rep_Clauses option
819 if Ignore_Rep_Clauses then
822 -- The following should be ignored. They do not affect legality
823 -- and may be target dependent. The basic idea of -gnatI is to
824 -- ignore any rep clauses that may be target dependent but do not
825 -- affect legality (except possibly to be rejected because they
826 -- are incompatible with the compilation target).
828 when Attribute_Alignment |
829 Attribute_Bit_Order |
830 Attribute_Component_Size |
831 Attribute_Machine_Radix |
832 Attribute_Object_Size |
835 Attribute_Stream_Size |
836 Attribute_Value_Size =>
838 Rewrite (N, Make_Null_Statement (Sloc (N)));
841 -- The following should not be ignored, because in the first place
842 -- they are reasonably portable, and should not cause problems in
843 -- compiling code from another target, and also they do affect
844 -- legality, e.g. failing to provide a stream attribute for a
845 -- type may make a program illegal.
847 when Attribute_External_Tag |
851 Attribute_Storage_Pool |
852 Attribute_Storage_Size |
856 -- Other cases are errors ("attribute& cannot be set with
857 -- definition clause"), which will be caught below.
867 if Rep_Item_Too_Early (Ent, N) then
871 -- Rep clause applies to full view of incomplete type or private type if
872 -- we have one (if not, this is a premature use of the type). However,
873 -- certain semantic checks need to be done on the specified entity (i.e.
874 -- the private view), so we save it in Ent.
876 if Is_Private_Type (Ent)
877 and then Is_Derived_Type (Ent)
878 and then not Is_Tagged_Type (Ent)
879 and then No (Full_View (Ent))
881 -- If this is a private type whose completion is a derivation from
882 -- another private type, there is no full view, and the attribute
883 -- belongs to the type itself, not its underlying parent.
887 elsif Ekind (Ent) = E_Incomplete_Type then
889 -- The attribute applies to the full view, set the entity of the
890 -- attribute definition accordingly.
892 Ent := Underlying_Type (Ent);
894 Set_Entity (Nam, Ent);
897 U_Ent := Underlying_Type (Ent);
900 -- Complete other routine error checks
902 if Etype (Nam) = Any_Type then
905 elsif Scope (Ent) /= Current_Scope then
906 Error_Msg_N ("entity must be declared in this scope", Nam);
909 elsif No (U_Ent) then
912 elsif Is_Type (U_Ent)
913 and then not Is_First_Subtype (U_Ent)
914 and then Id /= Attribute_Object_Size
915 and then Id /= Attribute_Value_Size
916 and then not From_At_Mod (N)
918 Error_Msg_N ("cannot specify attribute for subtype", Nam);
922 -- Switch on particular attribute
930 -- Address attribute definition clause
932 when Attribute_Address => Address : begin
934 -- A little error check, catch for X'Address use X'Address;
936 if Nkind (Nam) = N_Identifier
937 and then Nkind (Expr) = N_Attribute_Reference
938 and then Attribute_Name (Expr) = Name_Address
939 and then Nkind (Prefix (Expr)) = N_Identifier
940 and then Chars (Nam) = Chars (Prefix (Expr))
943 ("address for & is self-referencing", Prefix (Expr), Ent);
947 -- Not that special case, carry on with analysis of expression
949 Analyze_And_Resolve (Expr, RTE (RE_Address));
951 -- Even when ignoring rep clauses we need to indicate that the
952 -- entity has an address clause and thus it is legal to declare
955 if Ignore_Rep_Clauses then
956 if Ekind_In (U_Ent, E_Variable, E_Constant) then
957 Record_Rep_Item (U_Ent, N);
963 if Present (Address_Clause (U_Ent)) then
964 Error_Msg_N ("address already given for &", Nam);
966 -- Case of address clause for subprogram
968 elsif Is_Subprogram (U_Ent) then
969 if Has_Homonym (U_Ent) then
971 ("address clause cannot be given " &
972 "for overloaded subprogram",
977 -- For subprograms, all address clauses are permitted, and we
978 -- mark the subprogram as having a deferred freeze so that Gigi
979 -- will not elaborate it too soon.
981 -- Above needs more comments, what is too soon about???
983 Set_Has_Delayed_Freeze (U_Ent);
985 -- Case of address clause for entry
987 elsif Ekind (U_Ent) = E_Entry then
988 if Nkind (Parent (N)) = N_Task_Body then
990 ("entry address must be specified in task spec", Nam);
994 -- For entries, we require a constant address
996 Check_Constant_Address_Clause (Expr, U_Ent);
998 -- Special checks for task types
1000 if Is_Task_Type (Scope (U_Ent))
1001 and then Comes_From_Source (Scope (U_Ent))
1004 ("?entry address declared for entry in task type", N);
1006 ("\?only one task can be declared of this type", N);
1009 -- Entry address clauses are obsolescent
1011 Check_Restriction (No_Obsolescent_Features, N);
1013 if Warn_On_Obsolescent_Feature then
1015 ("attaching interrupt to task entry is an " &
1016 "obsolescent feature (RM J.7.1)?", N);
1018 ("\use interrupt procedure instead?", N);
1021 -- Case of an address clause for a controlled object which we
1022 -- consider to be erroneous.
1024 elsif Is_Controlled (Etype (U_Ent))
1025 or else Has_Controlled_Component (Etype (U_Ent))
1028 ("?controlled object& must not be overlaid", Nam, U_Ent);
1030 ("\?Program_Error will be raised at run time", Nam);
1031 Insert_Action (Declaration_Node (U_Ent),
1032 Make_Raise_Program_Error (Loc,
1033 Reason => PE_Overlaid_Controlled_Object));
1036 -- Case of address clause for a (non-controlled) object
1039 Ekind (U_Ent) = E_Variable
1041 Ekind (U_Ent) = E_Constant
1044 Expr : constant Node_Id := Expression (N);
1049 -- Exported variables cannot have an address clause, because
1050 -- this cancels the effect of the pragma Export.
1052 if Is_Exported (U_Ent) then
1054 ("cannot export object with address clause", Nam);
1058 Find_Overlaid_Entity (N, O_Ent, Off);
1060 -- Overlaying controlled objects is erroneous
1063 and then (Has_Controlled_Component (Etype (O_Ent))
1064 or else Is_Controlled (Etype (O_Ent)))
1067 ("?cannot overlay with controlled object", Expr);
1069 ("\?Program_Error will be raised at run time", Expr);
1070 Insert_Action (Declaration_Node (U_Ent),
1071 Make_Raise_Program_Error (Loc,
1072 Reason => PE_Overlaid_Controlled_Object));
1075 elsif Present (O_Ent)
1076 and then Ekind (U_Ent) = E_Constant
1077 and then not Is_Constant_Object (O_Ent)
1079 Error_Msg_N ("constant overlays a variable?", Expr);
1081 elsif Present (Renamed_Object (U_Ent)) then
1083 ("address clause not allowed"
1084 & " for a renaming declaration (RM 13.1(6))", Nam);
1087 -- Imported variables can have an address clause, but then
1088 -- the import is pretty meaningless except to suppress
1089 -- initializations, so we do not need such variables to
1090 -- be statically allocated (and in fact it causes trouble
1091 -- if the address clause is a local value).
1093 elsif Is_Imported (U_Ent) then
1094 Set_Is_Statically_Allocated (U_Ent, False);
1097 -- We mark a possible modification of a variable with an
1098 -- address clause, since it is likely aliasing is occurring.
1100 Note_Possible_Modification (Nam, Sure => False);
1102 -- Here we are checking for explicit overlap of one variable
1103 -- by another, and if we find this then mark the overlapped
1104 -- variable as also being volatile to prevent unwanted
1105 -- optimizations. This is a significant pessimization so
1106 -- avoid it when there is an offset, i.e. when the object
1107 -- is composite; they cannot be optimized easily anyway.
1110 and then Is_Object (O_Ent)
1113 Set_Treat_As_Volatile (O_Ent);
1116 -- Legality checks on the address clause for initialized
1117 -- objects is deferred until the freeze point, because
1118 -- a subsequent pragma might indicate that the object is
1119 -- imported and thus not initialized.
1121 Set_Has_Delayed_Freeze (U_Ent);
1123 -- If an initialization call has been generated for this
1124 -- object, it needs to be deferred to after the freeze node
1125 -- we have just now added, otherwise GIGI will see a
1126 -- reference to the variable (as actual to the IP call)
1127 -- before its definition.
1130 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1132 if Present (Init_Call) then
1134 Append_Freeze_Action (U_Ent, Init_Call);
1138 if Is_Exported (U_Ent) then
1140 ("& cannot be exported if an address clause is given",
1143 ("\define and export a variable " &
1144 "that holds its address instead",
1148 -- Entity has delayed freeze, so we will generate an
1149 -- alignment check at the freeze point unless suppressed.
1151 if not Range_Checks_Suppressed (U_Ent)
1152 and then not Alignment_Checks_Suppressed (U_Ent)
1154 Set_Check_Address_Alignment (N);
1157 -- Kill the size check code, since we are not allocating
1158 -- the variable, it is somewhere else.
1160 Kill_Size_Check_Code (U_Ent);
1162 -- If the address clause is of the form:
1164 -- for Y'Address use X'Address
1168 -- Const : constant Address := X'Address;
1170 -- for Y'Address use Const;
1172 -- then we make an entry in the table for checking the size
1173 -- and alignment of the overlaying variable. We defer this
1174 -- check till after code generation to take full advantage
1175 -- of the annotation done by the back end. This entry is
1176 -- only made if the address clause comes from source.
1177 -- If the entity has a generic type, the check will be
1178 -- performed in the instance if the actual type justifies
1179 -- it, and we do not insert the clause in the table to
1180 -- prevent spurious warnings.
1182 if Address_Clause_Overlay_Warnings
1183 and then Comes_From_Source (N)
1184 and then Present (O_Ent)
1185 and then Is_Object (O_Ent)
1187 if not Is_Generic_Type (Etype (U_Ent)) then
1188 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1191 -- If variable overlays a constant view, and we are
1192 -- warning on overlays, then mark the variable as
1193 -- overlaying a constant (we will give warnings later
1194 -- if this variable is assigned).
1196 if Is_Constant_Object (O_Ent)
1197 and then Ekind (U_Ent) = E_Variable
1199 Set_Overlays_Constant (U_Ent);
1204 -- Not a valid entity for an address clause
1207 Error_Msg_N ("address cannot be given for &", Nam);
1215 -- Alignment attribute definition clause
1217 when Attribute_Alignment => Alignment : declare
1218 Align : constant Uint := Get_Alignment_Value (Expr);
1223 if not Is_Type (U_Ent)
1224 and then Ekind (U_Ent) /= E_Variable
1225 and then Ekind (U_Ent) /= E_Constant
1227 Error_Msg_N ("alignment cannot be given for &", Nam);
1229 elsif Has_Alignment_Clause (U_Ent) then
1230 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1231 Error_Msg_N ("alignment clause previously given#", N);
1233 elsif Align /= No_Uint then
1234 Set_Has_Alignment_Clause (U_Ent);
1235 Set_Alignment (U_Ent, Align);
1237 -- For an array type, U_Ent is the first subtype. In that case,
1238 -- also set the alignment of the anonymous base type so that
1239 -- other subtypes (such as the itypes for aggregates of the
1240 -- type) also receive the expected alignment.
1242 if Is_Array_Type (U_Ent) then
1243 Set_Alignment (Base_Type (U_Ent), Align);
1252 -- Bit_Order attribute definition clause
1254 when Attribute_Bit_Order => Bit_Order : declare
1256 if not Is_Record_Type (U_Ent) then
1258 ("Bit_Order can only be defined for record type", Nam);
1261 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1263 if Etype (Expr) = Any_Type then
1266 elsif not Is_Static_Expression (Expr) then
1267 Flag_Non_Static_Expr
1268 ("Bit_Order requires static expression!", Expr);
1271 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1272 Set_Reverse_Bit_Order (U_Ent, True);
1278 --------------------
1279 -- Component_Size --
1280 --------------------
1282 -- Component_Size attribute definition clause
1284 when Attribute_Component_Size => Component_Size_Case : declare
1285 Csize : constant Uint := Static_Integer (Expr);
1289 New_Ctyp : Entity_Id;
1293 if not Is_Array_Type (U_Ent) then
1294 Error_Msg_N ("component size requires array type", Nam);
1298 Btype := Base_Type (U_Ent);
1299 Ctyp := Component_Type (Btype);
1301 if Has_Component_Size_Clause (Btype) then
1303 ("component size clause for& previously given", Nam);
1305 elsif Csize /= No_Uint then
1306 Check_Size (Expr, Ctyp, Csize, Biased);
1308 if Has_Aliased_Components (Btype)
1311 and then Csize /= 16
1314 ("component size incorrect for aliased components", N);
1318 -- For the biased case, build a declaration for a subtype
1319 -- that will be used to represent the biased subtype that
1320 -- reflects the biased representation of components. We need
1321 -- this subtype to get proper conversions on referencing
1322 -- elements of the array. Note that component size clauses
1323 -- are ignored in VM mode.
1325 if VM_Target = No_VM then
1328 Make_Defining_Identifier (Loc,
1330 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1333 Make_Subtype_Declaration (Loc,
1334 Defining_Identifier => New_Ctyp,
1335 Subtype_Indication =>
1336 New_Occurrence_Of (Component_Type (Btype), Loc));
1338 Set_Parent (Decl, N);
1339 Analyze (Decl, Suppress => All_Checks);
1341 Set_Has_Delayed_Freeze (New_Ctyp, False);
1342 Set_Esize (New_Ctyp, Csize);
1343 Set_RM_Size (New_Ctyp, Csize);
1344 Init_Alignment (New_Ctyp);
1345 Set_Has_Biased_Representation (New_Ctyp, True);
1346 Set_Is_Itype (New_Ctyp, True);
1347 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1349 Set_Component_Type (Btype, New_Ctyp);
1351 if Warn_On_Biased_Representation then
1353 ("?component size clause forces biased "
1354 & "representation", N);
1358 Set_Component_Size (Btype, Csize);
1360 -- For VM case, we ignore component size clauses
1363 -- Give a warning unless we are in GNAT mode, in which case
1364 -- the warning is suppressed since it is not useful.
1366 if not GNAT_Mode then
1368 ("?component size ignored in this configuration", N);
1372 -- Deal with warning on overridden size
1374 if Warn_On_Overridden_Size
1375 and then Has_Size_Clause (Ctyp)
1376 and then RM_Size (Ctyp) /= Csize
1379 ("?component size overrides size clause for&",
1383 Set_Has_Component_Size_Clause (Btype, True);
1384 Set_Has_Non_Standard_Rep (Btype, True);
1386 end Component_Size_Case;
1392 when Attribute_External_Tag => External_Tag :
1394 if not Is_Tagged_Type (U_Ent) then
1395 Error_Msg_N ("should be a tagged type", Nam);
1398 Analyze_And_Resolve (Expr, Standard_String);
1400 if not Is_Static_Expression (Expr) then
1401 Flag_Non_Static_Expr
1402 ("static string required for tag name!", Nam);
1405 if VM_Target = No_VM then
1406 Set_Has_External_Tag_Rep_Clause (U_Ent);
1408 Error_Msg_Name_1 := Attr;
1410 ("% attribute unsupported in this configuration", Nam);
1413 if not Is_Library_Level_Entity (U_Ent) then
1415 ("?non-unique external tag supplied for &", N, U_Ent);
1417 ("?\same external tag applies to all subprogram calls", N);
1419 ("?\corresponding internal tag cannot be obtained", N);
1427 when Attribute_Input =>
1428 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1429 Set_Has_Specified_Stream_Input (Ent);
1435 -- Machine radix attribute definition clause
1437 when Attribute_Machine_Radix => Machine_Radix : declare
1438 Radix : constant Uint := Static_Integer (Expr);
1441 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1442 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1444 elsif Has_Machine_Radix_Clause (U_Ent) then
1445 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1446 Error_Msg_N ("machine radix clause previously given#", N);
1448 elsif Radix /= No_Uint then
1449 Set_Has_Machine_Radix_Clause (U_Ent);
1450 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1454 elsif Radix = 10 then
1455 Set_Machine_Radix_10 (U_Ent);
1457 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1466 -- Object_Size attribute definition clause
1468 when Attribute_Object_Size => Object_Size : declare
1469 Size : constant Uint := Static_Integer (Expr);
1472 pragma Warnings (Off, Biased);
1475 if not Is_Type (U_Ent) then
1476 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1478 elsif Has_Object_Size_Clause (U_Ent) then
1479 Error_Msg_N ("Object_Size already given for &", Nam);
1482 Check_Size (Expr, U_Ent, Size, Biased);
1490 UI_Mod (Size, 64) /= 0
1493 ("Object_Size must be 8, 16, 32, or multiple of 64",
1497 Set_Esize (U_Ent, Size);
1498 Set_Has_Object_Size_Clause (U_Ent);
1499 Alignment_Check_For_Esize_Change (U_Ent);
1507 when Attribute_Output =>
1508 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1509 Set_Has_Specified_Stream_Output (Ent);
1515 when Attribute_Read =>
1516 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1517 Set_Has_Specified_Stream_Read (Ent);
1523 -- Size attribute definition clause
1525 when Attribute_Size => Size : declare
1526 Size : constant Uint := Static_Integer (Expr);
1533 if Has_Size_Clause (U_Ent) then
1534 Error_Msg_N ("size already given for &", Nam);
1536 elsif not Is_Type (U_Ent)
1537 and then Ekind (U_Ent) /= E_Variable
1538 and then Ekind (U_Ent) /= E_Constant
1540 Error_Msg_N ("size cannot be given for &", Nam);
1542 elsif Is_Array_Type (U_Ent)
1543 and then not Is_Constrained (U_Ent)
1546 ("size cannot be given for unconstrained array", Nam);
1548 elsif Size /= No_Uint then
1550 if VM_Target /= No_VM and then not GNAT_Mode then
1552 -- Size clause is not handled properly on VM targets.
1553 -- Display a warning unless we are in GNAT mode, in which
1554 -- case this is useless.
1557 ("?size clauses are ignored in this configuration", N);
1560 if Is_Type (U_Ent) then
1563 Etyp := Etype (U_Ent);
1566 -- Check size, note that Gigi is in charge of checking that the
1567 -- size of an array or record type is OK. Also we do not check
1568 -- the size in the ordinary fixed-point case, since it is too
1569 -- early to do so (there may be subsequent small clause that
1570 -- affects the size). We can check the size if a small clause
1571 -- has already been given.
1573 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1574 or else Has_Small_Clause (U_Ent)
1576 Check_Size (Expr, Etyp, Size, Biased);
1577 Set_Has_Biased_Representation (U_Ent, Biased);
1579 if Biased and Warn_On_Biased_Representation then
1581 ("?size clause forces biased representation", N);
1585 -- For types set RM_Size and Esize if possible
1587 if Is_Type (U_Ent) then
1588 Set_RM_Size (U_Ent, Size);
1590 -- For scalar types, increase Object_Size to power of 2, but
1591 -- not less than a storage unit in any case (i.e., normally
1592 -- this means it will be byte addressable).
1594 if Is_Scalar_Type (U_Ent) then
1595 if Size <= System_Storage_Unit then
1596 Init_Esize (U_Ent, System_Storage_Unit);
1597 elsif Size <= 16 then
1598 Init_Esize (U_Ent, 16);
1599 elsif Size <= 32 then
1600 Init_Esize (U_Ent, 32);
1602 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1605 -- For all other types, object size = value size. The
1606 -- backend will adjust as needed.
1609 Set_Esize (U_Ent, Size);
1612 Alignment_Check_For_Esize_Change (U_Ent);
1614 -- For objects, set Esize only
1617 if Is_Elementary_Type (Etyp) then
1618 if Size /= System_Storage_Unit
1620 Size /= System_Storage_Unit * 2
1622 Size /= System_Storage_Unit * 4
1624 Size /= System_Storage_Unit * 8
1626 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1627 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1629 ("size for primitive object must be a power of 2"
1630 & " in the range ^-^", N);
1634 Set_Esize (U_Ent, Size);
1637 Set_Has_Size_Clause (U_Ent);
1645 -- Small attribute definition clause
1647 when Attribute_Small => Small : declare
1648 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1652 Analyze_And_Resolve (Expr, Any_Real);
1654 if Etype (Expr) = Any_Type then
1657 elsif not Is_Static_Expression (Expr) then
1658 Flag_Non_Static_Expr
1659 ("small requires static expression!", Expr);
1663 Small := Expr_Value_R (Expr);
1665 if Small <= Ureal_0 then
1666 Error_Msg_N ("small value must be greater than zero", Expr);
1672 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1674 ("small requires an ordinary fixed point type", Nam);
1676 elsif Has_Small_Clause (U_Ent) then
1677 Error_Msg_N ("small already given for &", Nam);
1679 elsif Small > Delta_Value (U_Ent) then
1681 ("small value must not be greater then delta value", Nam);
1684 Set_Small_Value (U_Ent, Small);
1685 Set_Small_Value (Implicit_Base, Small);
1686 Set_Has_Small_Clause (U_Ent);
1687 Set_Has_Small_Clause (Implicit_Base);
1688 Set_Has_Non_Standard_Rep (Implicit_Base);
1696 -- Storage_Pool attribute definition clause
1698 when Attribute_Storage_Pool => Storage_Pool : declare
1703 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1705 ("storage pool cannot be given for access-to-subprogram type",
1710 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
1713 ("storage pool can only be given for access types", Nam);
1716 elsif Is_Derived_Type (U_Ent) then
1718 ("storage pool cannot be given for a derived access type",
1721 elsif Has_Storage_Size_Clause (U_Ent) then
1722 Error_Msg_N ("storage size already given for &", Nam);
1725 elsif Present (Associated_Storage_Pool (U_Ent)) then
1726 Error_Msg_N ("storage pool already given for &", Nam);
1731 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1733 if not Denotes_Variable (Expr) then
1734 Error_Msg_N ("storage pool must be a variable", Expr);
1738 if Nkind (Expr) = N_Type_Conversion then
1739 T := Etype (Expression (Expr));
1744 -- The Stack_Bounded_Pool is used internally for implementing
1745 -- access types with a Storage_Size. Since it only work
1746 -- properly when used on one specific type, we need to check
1747 -- that it is not hijacked improperly:
1748 -- type T is access Integer;
1749 -- for T'Storage_Size use n;
1750 -- type Q is access Float;
1751 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1753 if RTE_Available (RE_Stack_Bounded_Pool)
1754 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1756 Error_Msg_N ("non-shareable internal Pool", Expr);
1760 -- If the argument is a name that is not an entity name, then
1761 -- we construct a renaming operation to define an entity of
1762 -- type storage pool.
1764 if not Is_Entity_Name (Expr)
1765 and then Is_Object_Reference (Expr)
1767 Pool := Make_Temporary (Loc, 'P', Expr);
1770 Rnode : constant Node_Id :=
1771 Make_Object_Renaming_Declaration (Loc,
1772 Defining_Identifier => Pool,
1774 New_Occurrence_Of (Etype (Expr), Loc),
1778 Insert_Before (N, Rnode);
1780 Set_Associated_Storage_Pool (U_Ent, Pool);
1783 elsif Is_Entity_Name (Expr) then
1784 Pool := Entity (Expr);
1786 -- If pool is a renamed object, get original one. This can
1787 -- happen with an explicit renaming, and within instances.
1789 while Present (Renamed_Object (Pool))
1790 and then Is_Entity_Name (Renamed_Object (Pool))
1792 Pool := Entity (Renamed_Object (Pool));
1795 if Present (Renamed_Object (Pool))
1796 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1797 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1799 Pool := Entity (Expression (Renamed_Object (Pool)));
1802 Set_Associated_Storage_Pool (U_Ent, Pool);
1804 elsif Nkind (Expr) = N_Type_Conversion
1805 and then Is_Entity_Name (Expression (Expr))
1806 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1808 Pool := Entity (Expression (Expr));
1809 Set_Associated_Storage_Pool (U_Ent, Pool);
1812 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1821 -- Storage_Size attribute definition clause
1823 when Attribute_Storage_Size => Storage_Size : declare
1824 Btype : constant Entity_Id := Base_Type (U_Ent);
1828 if Is_Task_Type (U_Ent) then
1829 Check_Restriction (No_Obsolescent_Features, N);
1831 if Warn_On_Obsolescent_Feature then
1833 ("storage size clause for task is an " &
1834 "obsolescent feature (RM J.9)?", N);
1835 Error_Msg_N ("\use Storage_Size pragma instead?", N);
1841 if not Is_Access_Type (U_Ent)
1842 and then Ekind (U_Ent) /= E_Task_Type
1844 Error_Msg_N ("storage size cannot be given for &", Nam);
1846 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1848 ("storage size cannot be given for a derived access type",
1851 elsif Has_Storage_Size_Clause (Btype) then
1852 Error_Msg_N ("storage size already given for &", Nam);
1855 Analyze_And_Resolve (Expr, Any_Integer);
1857 if Is_Access_Type (U_Ent) then
1858 if Present (Associated_Storage_Pool (U_Ent)) then
1859 Error_Msg_N ("storage pool already given for &", Nam);
1863 if Compile_Time_Known_Value (Expr)
1864 and then Expr_Value (Expr) = 0
1866 Set_No_Pool_Assigned (Btype);
1869 else -- Is_Task_Type (U_Ent)
1870 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1872 if Present (Sprag) then
1873 Error_Msg_Sloc := Sloc (Sprag);
1875 ("Storage_Size already specified#", Nam);
1880 Set_Has_Storage_Size_Clause (Btype);
1888 when Attribute_Stream_Size => Stream_Size : declare
1889 Size : constant Uint := Static_Integer (Expr);
1892 if Ada_Version <= Ada_95 then
1893 Check_Restriction (No_Implementation_Attributes, N);
1896 if Has_Stream_Size_Clause (U_Ent) then
1897 Error_Msg_N ("Stream_Size already given for &", Nam);
1899 elsif Is_Elementary_Type (U_Ent) then
1900 if Size /= System_Storage_Unit
1902 Size /= System_Storage_Unit * 2
1904 Size /= System_Storage_Unit * 4
1906 Size /= System_Storage_Unit * 8
1908 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1910 ("stream size for elementary type must be a"
1911 & " power of 2 and at least ^", N);
1913 elsif RM_Size (U_Ent) > Size then
1914 Error_Msg_Uint_1 := RM_Size (U_Ent);
1916 ("stream size for elementary type must be a"
1917 & " power of 2 and at least ^", N);
1920 Set_Has_Stream_Size_Clause (U_Ent);
1923 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1931 -- Value_Size attribute definition clause
1933 when Attribute_Value_Size => Value_Size : declare
1934 Size : constant Uint := Static_Integer (Expr);
1938 if not Is_Type (U_Ent) then
1939 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1942 (Get_Attribute_Definition_Clause
1943 (U_Ent, Attribute_Value_Size))
1945 Error_Msg_N ("Value_Size already given for &", Nam);
1947 elsif Is_Array_Type (U_Ent)
1948 and then not Is_Constrained (U_Ent)
1951 ("Value_Size cannot be given for unconstrained array", Nam);
1954 if Is_Elementary_Type (U_Ent) then
1955 Check_Size (Expr, U_Ent, Size, Biased);
1956 Set_Has_Biased_Representation (U_Ent, Biased);
1958 if Biased and Warn_On_Biased_Representation then
1960 ("?value size clause forces biased representation", N);
1964 Set_RM_Size (U_Ent, Size);
1972 when Attribute_Write =>
1973 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1974 Set_Has_Specified_Stream_Write (Ent);
1976 -- All other attributes cannot be set
1980 ("attribute& cannot be set with definition clause", N);
1983 -- The test for the type being frozen must be performed after
1984 -- any expression the clause has been analyzed since the expression
1985 -- itself might cause freezing that makes the clause illegal.
1987 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1990 end Analyze_Attribute_Definition_Clause;
1992 ----------------------------
1993 -- Analyze_Code_Statement --
1994 ----------------------------
1996 procedure Analyze_Code_Statement (N : Node_Id) is
1997 HSS : constant Node_Id := Parent (N);
1998 SBody : constant Node_Id := Parent (HSS);
1999 Subp : constant Entity_Id := Current_Scope;
2006 -- Analyze and check we get right type, note that this implements the
2007 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
2008 -- is the only way that Asm_Insn could possibly be visible.
2010 Analyze_And_Resolve (Expression (N));
2012 if Etype (Expression (N)) = Any_Type then
2014 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
2015 Error_Msg_N ("incorrect type for code statement", N);
2019 Check_Code_Statement (N);
2021 -- Make sure we appear in the handled statement sequence of a
2022 -- subprogram (RM 13.8(3)).
2024 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2025 or else Nkind (SBody) /= N_Subprogram_Body
2028 ("code statement can only appear in body of subprogram", N);
2032 -- Do remaining checks (RM 13.8(3)) if not already done
2034 if not Is_Machine_Code_Subprogram (Subp) then
2035 Set_Is_Machine_Code_Subprogram (Subp);
2037 -- No exception handlers allowed
2039 if Present (Exception_Handlers (HSS)) then
2041 ("exception handlers not permitted in machine code subprogram",
2042 First (Exception_Handlers (HSS)));
2045 -- No declarations other than use clauses and pragmas (we allow
2046 -- certain internally generated declarations as well).
2048 Decl := First (Declarations (SBody));
2049 while Present (Decl) loop
2050 DeclO := Original_Node (Decl);
2051 if Comes_From_Source (DeclO)
2052 and not Nkind_In (DeclO, N_Pragma,
2053 N_Use_Package_Clause,
2055 N_Implicit_Label_Declaration)
2058 ("this declaration not allowed in machine code subprogram",
2065 -- No statements other than code statements, pragmas, and labels.
2066 -- Again we allow certain internally generated statements.
2068 Stmt := First (Statements (HSS));
2069 while Present (Stmt) loop
2070 StmtO := Original_Node (Stmt);
2071 if Comes_From_Source (StmtO)
2072 and then not Nkind_In (StmtO, N_Pragma,
2077 ("this statement is not allowed in machine code subprogram",
2084 end Analyze_Code_Statement;
2086 -----------------------------------------------
2087 -- Analyze_Enumeration_Representation_Clause --
2088 -----------------------------------------------
2090 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2091 Ident : constant Node_Id := Identifier (N);
2092 Aggr : constant Node_Id := Array_Aggregate (N);
2093 Enumtype : Entity_Id;
2099 Err : Boolean := False;
2101 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2102 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2103 -- Allowed range of universal integer (= allowed range of enum lit vals)
2107 -- Minimum and maximum values of entries
2110 -- Pointer to node for literal providing max value
2113 if Ignore_Rep_Clauses then
2117 -- First some basic error checks
2120 Enumtype := Entity (Ident);
2122 if Enumtype = Any_Type
2123 or else Rep_Item_Too_Early (Enumtype, N)
2127 Enumtype := Underlying_Type (Enumtype);
2130 if not Is_Enumeration_Type (Enumtype) then
2132 ("enumeration type required, found}",
2133 Ident, First_Subtype (Enumtype));
2137 -- Ignore rep clause on generic actual type. This will already have
2138 -- been flagged on the template as an error, and this is the safest
2139 -- way to ensure we don't get a junk cascaded message in the instance.
2141 if Is_Generic_Actual_Type (Enumtype) then
2144 -- Type must be in current scope
2146 elsif Scope (Enumtype) /= Current_Scope then
2147 Error_Msg_N ("type must be declared in this scope", Ident);
2150 -- Type must be a first subtype
2152 elsif not Is_First_Subtype (Enumtype) then
2153 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2156 -- Ignore duplicate rep clause
2158 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2159 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2162 -- Don't allow rep clause for standard [wide_[wide_]]character
2164 elsif Is_Standard_Character_Type (Enumtype) then
2165 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2168 -- Check that the expression is a proper aggregate (no parentheses)
2170 elsif Paren_Count (Aggr) /= 0 then
2172 ("extra parentheses surrounding aggregate not allowed",
2176 -- All tests passed, so set rep clause in place
2179 Set_Has_Enumeration_Rep_Clause (Enumtype);
2180 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2183 -- Now we process the aggregate. Note that we don't use the normal
2184 -- aggregate code for this purpose, because we don't want any of the
2185 -- normal expansion activities, and a number of special semantic
2186 -- rules apply (including the component type being any integer type)
2188 Elit := First_Literal (Enumtype);
2190 -- First the positional entries if any
2192 if Present (Expressions (Aggr)) then
2193 Expr := First (Expressions (Aggr));
2194 while Present (Expr) loop
2196 Error_Msg_N ("too many entries in aggregate", Expr);
2200 Val := Static_Integer (Expr);
2202 -- Err signals that we found some incorrect entries processing
2203 -- the list. The final checks for completeness and ordering are
2204 -- skipped in this case.
2206 if Val = No_Uint then
2208 elsif Val < Lo or else Hi < Val then
2209 Error_Msg_N ("value outside permitted range", Expr);
2213 Set_Enumeration_Rep (Elit, Val);
2214 Set_Enumeration_Rep_Expr (Elit, Expr);
2220 -- Now process the named entries if present
2222 if Present (Component_Associations (Aggr)) then
2223 Assoc := First (Component_Associations (Aggr));
2224 while Present (Assoc) loop
2225 Choice := First (Choices (Assoc));
2227 if Present (Next (Choice)) then
2229 ("multiple choice not allowed here", Next (Choice));
2233 if Nkind (Choice) = N_Others_Choice then
2234 Error_Msg_N ("others choice not allowed here", Choice);
2237 elsif Nkind (Choice) = N_Range then
2238 -- ??? should allow zero/one element range here
2239 Error_Msg_N ("range not allowed here", Choice);
2243 Analyze_And_Resolve (Choice, Enumtype);
2245 if Is_Entity_Name (Choice)
2246 and then Is_Type (Entity (Choice))
2248 Error_Msg_N ("subtype name not allowed here", Choice);
2250 -- ??? should allow static subtype with zero/one entry
2252 elsif Etype (Choice) = Base_Type (Enumtype) then
2253 if not Is_Static_Expression (Choice) then
2254 Flag_Non_Static_Expr
2255 ("non-static expression used for choice!", Choice);
2259 Elit := Expr_Value_E (Choice);
2261 if Present (Enumeration_Rep_Expr (Elit)) then
2262 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2264 ("representation for& previously given#",
2269 Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
2271 Expr := Expression (Assoc);
2272 Val := Static_Integer (Expr);
2274 if Val = No_Uint then
2277 elsif Val < Lo or else Hi < Val then
2278 Error_Msg_N ("value outside permitted range", Expr);
2282 Set_Enumeration_Rep (Elit, Val);
2291 -- Aggregate is fully processed. Now we check that a full set of
2292 -- representations was given, and that they are in range and in order.
2293 -- These checks are only done if no other errors occurred.
2299 Elit := First_Literal (Enumtype);
2300 while Present (Elit) loop
2301 if No (Enumeration_Rep_Expr (Elit)) then
2302 Error_Msg_NE ("missing representation for&!", N, Elit);
2305 Val := Enumeration_Rep (Elit);
2307 if Min = No_Uint then
2311 if Val /= No_Uint then
2312 if Max /= No_Uint and then Val <= Max then
2314 ("enumeration value for& not ordered!",
2315 Enumeration_Rep_Expr (Elit), Elit);
2318 Max_Node := Enumeration_Rep_Expr (Elit);
2322 -- If there is at least one literal whose representation is not
2323 -- equal to the Pos value, then note that this enumeration type
2324 -- has a non-standard representation.
2326 if Val /= Enumeration_Pos (Elit) then
2327 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2334 -- Now set proper size information
2337 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2340 if Has_Size_Clause (Enumtype) then
2342 -- All OK, if size is OK now
2344 if RM_Size (Enumtype) >= Minsize then
2348 -- Try if we can get by with biasing
2351 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2353 -- Error message if even biasing does not work
2355 if RM_Size (Enumtype) < Minsize then
2356 Error_Msg_Uint_1 := RM_Size (Enumtype);
2357 Error_Msg_Uint_2 := Max;
2359 ("previously given size (^) is too small "
2360 & "for this value (^)", Max_Node);
2362 -- If biasing worked, indicate that we now have biased rep
2365 Set_Has_Biased_Representation (Enumtype);
2370 Set_RM_Size (Enumtype, Minsize);
2371 Set_Enum_Esize (Enumtype);
2374 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2375 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2376 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2380 -- We repeat the too late test in case it froze itself!
2382 if Rep_Item_Too_Late (Enumtype, N) then
2385 end Analyze_Enumeration_Representation_Clause;
2387 ----------------------------
2388 -- Analyze_Free_Statement --
2389 ----------------------------
2391 procedure Analyze_Free_Statement (N : Node_Id) is
2393 Analyze (Expression (N));
2394 end Analyze_Free_Statement;
2396 ---------------------------
2397 -- Analyze_Freeze_Entity --
2398 ---------------------------
2400 procedure Analyze_Freeze_Entity (N : Node_Id) is
2401 E : constant Entity_Id := Entity (N);
2404 -- For tagged types covering interfaces add internal entities that link
2405 -- the primitives of the interfaces with the primitives that cover them.
2407 -- Note: These entities were originally generated only when generating
2408 -- code because their main purpose was to provide support to initialize
2409 -- the secondary dispatch tables. They are now generated also when
2410 -- compiling with no code generation to provide ASIS the relationship
2411 -- between interface primitives and tagged type primitives. They are
2412 -- also used to locate primitives covering interfaces when processing
2413 -- generics (see Derive_Subprograms).
2415 if Ada_Version >= Ada_05
2416 and then Ekind (E) = E_Record_Type
2417 and then Is_Tagged_Type (E)
2418 and then not Is_Interface (E)
2419 and then Has_Interfaces (E)
2421 -- This would be a good common place to call the routine that checks
2422 -- overriding of interface primitives (and thus factorize calls to
2423 -- Check_Abstract_Overriding located at different contexts in the
2424 -- compiler). However, this is not possible because it causes
2425 -- spurious errors in case of late overriding.
2427 Add_Internal_Interface_Entities (E);
2432 if Ekind (E) = E_Record_Type
2433 and then Is_CPP_Class (E)
2434 and then Is_Tagged_Type (E)
2435 and then Tagged_Type_Expansion
2436 and then Expander_Active
2438 if CPP_Num_Prims (E) = 0 then
2440 -- If the CPP type has user defined components then it must import
2441 -- primitives from C++. This is required because if the C++ class
2442 -- has no primitives then the C++ compiler does not added the _tag
2443 -- component to the type.
2445 pragma Assert (Chars (First_Entity (E)) = Name_uTag);
2447 if First_Entity (E) /= Last_Entity (E) then
2449 ("?'C'P'P type must import at least one primitive from C++",
2454 -- Check that all its primitives are abstract or imported from C++.
2455 -- Check also availability of the C++ constructor.
2458 Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
2460 Error_Reported : Boolean := False;
2464 Elmt := First_Elmt (Primitive_Operations (E));
2465 while Present (Elmt) loop
2466 Prim := Node (Elmt);
2468 if Comes_From_Source (Prim) then
2469 if Is_Abstract_Subprogram (Prim) then
2472 elsif not Is_Imported (Prim)
2473 or else Convention (Prim) /= Convention_CPP
2476 ("?primitives of 'C'P'P types must be imported from C++"
2477 & " or abstract", Prim);
2479 elsif not Has_Constructors
2480 and then not Error_Reported
2482 Error_Msg_Name_1 := Chars (E);
2484 ("?'C'P'P constructor required for type %", Prim);
2485 Error_Reported := True;
2493 end Analyze_Freeze_Entity;
2495 ------------------------------------------
2496 -- Analyze_Record_Representation_Clause --
2497 ------------------------------------------
2499 -- Note: we check as much as we can here, but we can't do any checks
2500 -- based on the position values (e.g. overlap checks) until freeze time
2501 -- because especially in Ada 2005 (machine scalar mode), the processing
2502 -- for non-standard bit order can substantially change the positions.
2503 -- See procedure Check_Record_Representation_Clause (called from Freeze)
2504 -- for the remainder of this processing.
2506 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2507 Ident : constant Node_Id := Identifier (N);
2508 Rectype : Entity_Id;
2513 Hbit : Uint := Uint_0;
2518 CR_Pragma : Node_Id := Empty;
2519 -- Points to N_Pragma node if Complete_Representation pragma present
2522 if Ignore_Rep_Clauses then
2527 Rectype := Entity (Ident);
2529 if Rectype = Any_Type
2530 or else Rep_Item_Too_Early (Rectype, N)
2534 Rectype := Underlying_Type (Rectype);
2537 -- First some basic error checks
2539 if not Is_Record_Type (Rectype) then
2541 ("record type required, found}", Ident, First_Subtype (Rectype));
2544 elsif Is_Unchecked_Union (Rectype) then
2546 ("record rep clause not allowed for Unchecked_Union", N);
2548 elsif Scope (Rectype) /= Current_Scope then
2549 Error_Msg_N ("type must be declared in this scope", N);
2552 elsif not Is_First_Subtype (Rectype) then
2553 Error_Msg_N ("cannot give record rep clause for subtype", N);
2556 elsif Has_Record_Rep_Clause (Rectype) then
2557 Error_Msg_N ("duplicate record rep clause ignored", N);
2560 elsif Rep_Item_Too_Late (Rectype, N) then
2564 if Present (Mod_Clause (N)) then
2566 Loc : constant Source_Ptr := Sloc (N);
2567 M : constant Node_Id := Mod_Clause (N);
2568 P : constant List_Id := Pragmas_Before (M);
2572 pragma Warnings (Off, Mod_Val);
2575 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2577 if Warn_On_Obsolescent_Feature then
2579 ("mod clause is an obsolescent feature (RM J.8)?", N);
2581 ("\use alignment attribute definition clause instead?", N);
2588 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2589 -- the Mod clause into an alignment clause anyway, so that the
2590 -- back-end can compute and back-annotate properly the size and
2591 -- alignment of types that may include this record.
2593 -- This seems dubious, this destroys the source tree in a manner
2594 -- not detectable by ASIS ???
2596 if Operating_Mode = Check_Semantics
2600 Make_Attribute_Definition_Clause (Loc,
2601 Name => New_Reference_To (Base_Type (Rectype), Loc),
2602 Chars => Name_Alignment,
2603 Expression => Relocate_Node (Expression (M)));
2605 Set_From_At_Mod (AtM_Nod);
2606 Insert_After (N, AtM_Nod);
2607 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2608 Set_Mod_Clause (N, Empty);
2611 -- Get the alignment value to perform error checking
2613 Mod_Val := Get_Alignment_Value (Expression (M));
2618 -- For untagged types, clear any existing component clauses for the
2619 -- type. If the type is derived, this is what allows us to override
2620 -- a rep clause for the parent. For type extensions, the representation
2621 -- of the inherited components is inherited, so we want to keep previous
2622 -- component clauses for completeness.
2624 if not Is_Tagged_Type (Rectype) then
2625 Comp := First_Component_Or_Discriminant (Rectype);
2626 while Present (Comp) loop
2627 Set_Component_Clause (Comp, Empty);
2628 Next_Component_Or_Discriminant (Comp);
2632 -- All done if no component clauses
2634 CC := First (Component_Clauses (N));
2640 -- A representation like this applies to the base type
2642 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2643 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2644 Set_Has_Specified_Layout (Base_Type (Rectype));
2646 -- Process the component clauses
2648 while Present (CC) loop
2652 if Nkind (CC) = N_Pragma then
2655 -- The only pragma of interest is Complete_Representation
2657 if Pragma_Name (CC) = Name_Complete_Representation then
2661 -- Processing for real component clause
2664 Posit := Static_Integer (Position (CC));
2665 Fbit := Static_Integer (First_Bit (CC));
2666 Lbit := Static_Integer (Last_Bit (CC));
2669 and then Fbit /= No_Uint
2670 and then Lbit /= No_Uint
2674 ("position cannot be negative", Position (CC));
2678 ("first bit cannot be negative", First_Bit (CC));
2680 -- The Last_Bit specified in a component clause must not be
2681 -- less than the First_Bit minus one (RM-13.5.1(10)).
2683 elsif Lbit < Fbit - 1 then
2685 ("last bit cannot be less than first bit minus one",
2688 -- Values look OK, so find the corresponding record component
2689 -- Even though the syntax allows an attribute reference for
2690 -- implementation-defined components, GNAT does not allow the
2691 -- tag to get an explicit position.
2693 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2694 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2695 Error_Msg_N ("position of tag cannot be specified", CC);
2697 Error_Msg_N ("illegal component name", CC);
2701 Comp := First_Entity (Rectype);
2702 while Present (Comp) loop
2703 exit when Chars (Comp) = Chars (Component_Name (CC));
2709 -- Maybe component of base type that is absent from
2710 -- statically constrained first subtype.
2712 Comp := First_Entity (Base_Type (Rectype));
2713 while Present (Comp) loop
2714 exit when Chars (Comp) = Chars (Component_Name (CC));
2721 ("component clause is for non-existent field", CC);
2723 elsif Present (Component_Clause (Comp)) then
2725 -- Diagnose duplicate rep clause, or check consistency
2726 -- if this is an inherited component. In a double fault,
2727 -- there may be a duplicate inconsistent clause for an
2728 -- inherited component.
2730 if Scope (Original_Record_Component (Comp)) = Rectype
2731 or else Parent (Component_Clause (Comp)) = N
2733 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2734 Error_Msg_N ("component clause previously given#", CC);
2738 Rep1 : constant Node_Id := Component_Clause (Comp);
2740 if Intval (Position (Rep1)) /=
2741 Intval (Position (CC))
2742 or else Intval (First_Bit (Rep1)) /=
2743 Intval (First_Bit (CC))
2744 or else Intval (Last_Bit (Rep1)) /=
2745 Intval (Last_Bit (CC))
2747 Error_Msg_N ("component clause inconsistent "
2748 & "with representation of ancestor", CC);
2749 elsif Warn_On_Redundant_Constructs then
2750 Error_Msg_N ("?redundant component clause "
2751 & "for inherited component!", CC);
2756 -- Normal case where this is the first component clause we
2757 -- have seen for this entity, so set it up properly.
2760 -- Make reference for field in record rep clause and set
2761 -- appropriate entity field in the field identifier.
2764 (Comp, Component_Name (CC), Set_Ref => False);
2765 Set_Entity (Component_Name (CC), Comp);
2767 -- Update Fbit and Lbit to the actual bit number
2769 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2770 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2772 if Has_Size_Clause (Rectype)
2773 and then Esize (Rectype) <= Lbit
2776 ("bit number out of range of specified size",
2779 Set_Component_Clause (Comp, CC);
2780 Set_Component_Bit_Offset (Comp, Fbit);
2781 Set_Esize (Comp, 1 + (Lbit - Fbit));
2782 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2783 Set_Normalized_Position (Comp, Fbit / SSU);
2785 if Warn_On_Overridden_Size
2786 and then Has_Size_Clause (Etype (Comp))
2787 and then RM_Size (Etype (Comp)) /= Esize (Comp)
2790 ("?component size overrides size clause for&",
2791 Component_Name (CC), Etype (Comp));
2794 -- This information is also set in the corresponding
2795 -- component of the base type, found by accessing the
2796 -- Original_Record_Component link if it is present.
2798 Ocomp := Original_Record_Component (Comp);
2805 (Component_Name (CC),
2810 Set_Has_Biased_Representation (Comp, Biased);
2812 if Biased and Warn_On_Biased_Representation then
2814 ("?component clause forces biased "
2815 & "representation", CC);
2818 if Present (Ocomp) then
2819 Set_Component_Clause (Ocomp, CC);
2820 Set_Component_Bit_Offset (Ocomp, Fbit);
2821 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2822 Set_Normalized_Position (Ocomp, Fbit / SSU);
2823 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2825 Set_Normalized_Position_Max
2826 (Ocomp, Normalized_Position (Ocomp));
2828 Set_Has_Biased_Representation
2829 (Ocomp, Has_Biased_Representation (Comp));
2832 if Esize (Comp) < 0 then
2833 Error_Msg_N ("component size is negative", CC);
2844 -- Check missing components if Complete_Representation pragma appeared
2846 if Present (CR_Pragma) then
2847 Comp := First_Component_Or_Discriminant (Rectype);
2848 while Present (Comp) loop
2849 if No (Component_Clause (Comp)) then
2851 ("missing component clause for &", CR_Pragma, Comp);
2854 Next_Component_Or_Discriminant (Comp);
2857 -- If no Complete_Representation pragma, warn if missing components
2859 elsif Warn_On_Unrepped_Components then
2861 Num_Repped_Components : Nat := 0;
2862 Num_Unrepped_Components : Nat := 0;
2865 -- First count number of repped and unrepped components
2867 Comp := First_Component_Or_Discriminant (Rectype);
2868 while Present (Comp) loop
2869 if Present (Component_Clause (Comp)) then
2870 Num_Repped_Components := Num_Repped_Components + 1;
2872 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2875 Next_Component_Or_Discriminant (Comp);
2878 -- We are only interested in the case where there is at least one
2879 -- unrepped component, and at least half the components have rep
2880 -- clauses. We figure that if less than half have them, then the
2881 -- partial rep clause is really intentional. If the component
2882 -- type has no underlying type set at this point (as for a generic
2883 -- formal type), we don't know enough to give a warning on the
2886 if Num_Unrepped_Components > 0
2887 and then Num_Unrepped_Components < Num_Repped_Components
2889 Comp := First_Component_Or_Discriminant (Rectype);
2890 while Present (Comp) loop
2891 if No (Component_Clause (Comp))
2892 and then Comes_From_Source (Comp)
2893 and then Present (Underlying_Type (Etype (Comp)))
2894 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2895 or else Size_Known_At_Compile_Time
2896 (Underlying_Type (Etype (Comp))))
2897 and then not Has_Warnings_Off (Rectype)
2899 Error_Msg_Sloc := Sloc (Comp);
2901 ("?no component clause given for & declared #",
2905 Next_Component_Or_Discriminant (Comp);
2910 end Analyze_Record_Representation_Clause;
2912 -----------------------------------
2913 -- Check_Constant_Address_Clause --
2914 -----------------------------------
2916 procedure Check_Constant_Address_Clause
2920 procedure Check_At_Constant_Address (Nod : Node_Id);
2921 -- Checks that the given node N represents a name whose 'Address is
2922 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2923 -- address value is the same at the point of declaration of U_Ent and at
2924 -- the time of elaboration of the address clause.
2926 procedure Check_Expr_Constants (Nod : Node_Id);
2927 -- Checks that Nod meets the requirements for a constant address clause
2928 -- in the sense of the enclosing procedure.
2930 procedure Check_List_Constants (Lst : List_Id);
2931 -- Check that all elements of list Lst meet the requirements for a
2932 -- constant address clause in the sense of the enclosing procedure.
2934 -------------------------------
2935 -- Check_At_Constant_Address --
2936 -------------------------------
2938 procedure Check_At_Constant_Address (Nod : Node_Id) is
2940 if Is_Entity_Name (Nod) then
2941 if Present (Address_Clause (Entity ((Nod)))) then
2943 ("invalid address clause for initialized object &!",
2946 ("address for& cannot" &
2947 " depend on another address clause! (RM 13.1(22))!",
2950 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2951 and then Sloc (U_Ent) < Sloc (Entity (Nod))
2954 ("invalid address clause for initialized object &!",
2956 Error_Msg_Node_2 := U_Ent;
2958 ("\& must be defined before & (RM 13.1(22))!",
2962 elsif Nkind (Nod) = N_Selected_Component then
2964 T : constant Entity_Id := Etype (Prefix (Nod));
2967 if (Is_Record_Type (T)
2968 and then Has_Discriminants (T))
2971 and then Is_Record_Type (Designated_Type (T))
2972 and then Has_Discriminants (Designated_Type (T)))
2975 ("invalid address clause for initialized object &!",
2978 ("\address cannot depend on component" &
2979 " of discriminated record (RM 13.1(22))!",
2982 Check_At_Constant_Address (Prefix (Nod));
2986 elsif Nkind (Nod) = N_Indexed_Component then
2987 Check_At_Constant_Address (Prefix (Nod));
2988 Check_List_Constants (Expressions (Nod));
2991 Check_Expr_Constants (Nod);
2993 end Check_At_Constant_Address;
2995 --------------------------
2996 -- Check_Expr_Constants --
2997 --------------------------
2999 procedure Check_Expr_Constants (Nod : Node_Id) is
3000 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
3001 Ent : Entity_Id := Empty;
3004 if Nkind (Nod) in N_Has_Etype
3005 and then Etype (Nod) = Any_Type
3011 when N_Empty | N_Error =>
3014 when N_Identifier | N_Expanded_Name =>
3015 Ent := Entity (Nod);
3017 -- We need to look at the original node if it is different
3018 -- from the node, since we may have rewritten things and
3019 -- substituted an identifier representing the rewrite.
3021 if Original_Node (Nod) /= Nod then
3022 Check_Expr_Constants (Original_Node (Nod));
3024 -- If the node is an object declaration without initial
3025 -- value, some code has been expanded, and the expression
3026 -- is not constant, even if the constituents might be
3027 -- acceptable, as in A'Address + offset.
3029 if Ekind (Ent) = E_Variable
3031 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3033 No (Expression (Declaration_Node (Ent)))
3036 ("invalid address clause for initialized object &!",
3039 -- If entity is constant, it may be the result of expanding
3040 -- a check. We must verify that its declaration appears
3041 -- before the object in question, else we also reject the
3044 elsif Ekind (Ent) = E_Constant
3045 and then In_Same_Source_Unit (Ent, U_Ent)
3046 and then Sloc (Ent) > Loc_U_Ent
3049 ("invalid address clause for initialized object &!",
3056 -- Otherwise look at the identifier and see if it is OK
3058 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
3059 or else Is_Type (Ent)
3064 Ekind (Ent) = E_Constant
3066 Ekind (Ent) = E_In_Parameter
3068 -- This is the case where we must have Ent defined before
3069 -- U_Ent. Clearly if they are in different units this
3070 -- requirement is met since the unit containing Ent is
3071 -- already processed.
3073 if not In_Same_Source_Unit (Ent, U_Ent) then
3076 -- Otherwise location of Ent must be before the location
3077 -- of U_Ent, that's what prior defined means.
3079 elsif Sloc (Ent) < Loc_U_Ent then
3084 ("invalid address clause for initialized object &!",
3086 Error_Msg_Node_2 := U_Ent;
3088 ("\& must be defined before & (RM 13.1(22))!",
3092 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3093 Check_Expr_Constants (Original_Node (Nod));
3097 ("invalid address clause for initialized object &!",
3100 if Comes_From_Source (Ent) then
3102 ("\reference to variable& not allowed"
3103 & " (RM 13.1(22))!", Nod, Ent);
3106 ("non-static expression not allowed"
3107 & " (RM 13.1(22))!", Nod);
3111 when N_Integer_Literal =>
3113 -- If this is a rewritten unchecked conversion, in a system
3114 -- where Address is an integer type, always use the base type
3115 -- for a literal value. This is user-friendly and prevents
3116 -- order-of-elaboration issues with instances of unchecked
3119 if Nkind (Original_Node (Nod)) = N_Function_Call then
3120 Set_Etype (Nod, Base_Type (Etype (Nod)));
3123 when N_Real_Literal |
3125 N_Character_Literal =>
3129 Check_Expr_Constants (Low_Bound (Nod));
3130 Check_Expr_Constants (High_Bound (Nod));
3132 when N_Explicit_Dereference =>
3133 Check_Expr_Constants (Prefix (Nod));
3135 when N_Indexed_Component =>
3136 Check_Expr_Constants (Prefix (Nod));
3137 Check_List_Constants (Expressions (Nod));
3140 Check_Expr_Constants (Prefix (Nod));
3141 Check_Expr_Constants (Discrete_Range (Nod));
3143 when N_Selected_Component =>
3144 Check_Expr_Constants (Prefix (Nod));
3146 when N_Attribute_Reference =>
3147 if Attribute_Name (Nod) = Name_Address
3149 Attribute_Name (Nod) = Name_Access
3151 Attribute_Name (Nod) = Name_Unchecked_Access
3153 Attribute_Name (Nod) = Name_Unrestricted_Access
3155 Check_At_Constant_Address (Prefix (Nod));
3158 Check_Expr_Constants (Prefix (Nod));
3159 Check_List_Constants (Expressions (Nod));
3163 Check_List_Constants (Component_Associations (Nod));
3164 Check_List_Constants (Expressions (Nod));
3166 when N_Component_Association =>
3167 Check_Expr_Constants (Expression (Nod));
3169 when N_Extension_Aggregate =>
3170 Check_Expr_Constants (Ancestor_Part (Nod));
3171 Check_List_Constants (Component_Associations (Nod));
3172 Check_List_Constants (Expressions (Nod));
3177 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3178 Check_Expr_Constants (Left_Opnd (Nod));
3179 Check_Expr_Constants (Right_Opnd (Nod));
3182 Check_Expr_Constants (Right_Opnd (Nod));
3184 when N_Type_Conversion |
3185 N_Qualified_Expression |
3187 Check_Expr_Constants (Expression (Nod));
3189 when N_Unchecked_Type_Conversion =>
3190 Check_Expr_Constants (Expression (Nod));
3192 -- If this is a rewritten unchecked conversion, subtypes in
3193 -- this node are those created within the instance. To avoid
3194 -- order of elaboration issues, replace them with their base
3195 -- types. Note that address clauses can cause order of
3196 -- elaboration problems because they are elaborated by the
3197 -- back-end at the point of definition, and may mention
3198 -- entities declared in between (as long as everything is
3199 -- static). It is user-friendly to allow unchecked conversions
3202 if Nkind (Original_Node (Nod)) = N_Function_Call then
3203 Set_Etype (Expression (Nod),
3204 Base_Type (Etype (Expression (Nod))));
3205 Set_Etype (Nod, Base_Type (Etype (Nod)));
3208 when N_Function_Call =>
3209 if not Is_Pure (Entity (Name (Nod))) then
3211 ("invalid address clause for initialized object &!",
3215 ("\function & is not pure (RM 13.1(22))!",
3216 Nod, Entity (Name (Nod)));
3219 Check_List_Constants (Parameter_Associations (Nod));
3222 when N_Parameter_Association =>
3223 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3227 ("invalid address clause for initialized object &!",
3230 ("\must be constant defined before& (RM 13.1(22))!",
3233 end Check_Expr_Constants;
3235 --------------------------
3236 -- Check_List_Constants --
3237 --------------------------
3239 procedure Check_List_Constants (Lst : List_Id) is
3243 if Present (Lst) then
3244 Nod1 := First (Lst);
3245 while Present (Nod1) loop
3246 Check_Expr_Constants (Nod1);
3250 end Check_List_Constants;
3252 -- Start of processing for Check_Constant_Address_Clause
3255 -- If rep_clauses are to be ignored, no need for legality checks. In
3256 -- particular, no need to pester user about rep clauses that violate
3257 -- the rule on constant addresses, given that these clauses will be
3258 -- removed by Freeze before they reach the back end.
3260 if not Ignore_Rep_Clauses then
3261 Check_Expr_Constants (Expr);
3263 end Check_Constant_Address_Clause;
3265 ----------------------------------------
3266 -- Check_Record_Representation_Clause --
3267 ----------------------------------------
3269 procedure Check_Record_Representation_Clause (N : Node_Id) is
3270 Loc : constant Source_Ptr := Sloc (N);
3271 Ident : constant Node_Id := Identifier (N);
3272 Rectype : Entity_Id;
3277 Hbit : Uint := Uint_0;
3281 Max_Bit_So_Far : Uint;
3282 -- Records the maximum bit position so far. If all field positions
3283 -- are monotonically increasing, then we can skip the circuit for
3284 -- checking for overlap, since no overlap is possible.
3286 Tagged_Parent : Entity_Id := Empty;
3287 -- This is set in the case of a derived tagged type for which we have
3288 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
3289 -- positioned by record representation clauses). In this case we must
3290 -- check for overlap between components of this tagged type, and the
3291 -- components of its parent. Tagged_Parent will point to this parent
3292 -- type. For all other cases Tagged_Parent is left set to Empty.
3294 Parent_Last_Bit : Uint;
3295 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
3296 -- last bit position for any field in the parent type. We only need to
3297 -- check overlap for fields starting below this point.
3299 Overlap_Check_Required : Boolean;
3300 -- Used to keep track of whether or not an overlap check is required
3302 Overlap_Detected : Boolean := False;
3303 -- Set True if an overlap is detected
3305 Ccount : Natural := 0;
3306 -- Number of component clauses in record rep clause
3308 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
3309 -- Given two entities for record components or discriminants, checks
3310 -- if they have overlapping component clauses and issues errors if so.
3312 procedure Find_Component;
3313 -- Finds component entity corresponding to current component clause (in
3314 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
3315 -- start/stop bits for the field. If there is no matching component or
3316 -- if the matching component does not have a component clause, then
3317 -- that's an error and Comp is set to Empty, but no error message is
3318 -- issued, since the message was already given. Comp is also set to
3319 -- Empty if the current "component clause" is in fact a pragma.
3321 -----------------------------
3322 -- Check_Component_Overlap --
3323 -----------------------------
3325 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
3326 CC1 : constant Node_Id := Component_Clause (C1_Ent);
3327 CC2 : constant Node_Id := Component_Clause (C2_Ent);
3330 if Present (CC1) and then Present (CC2) then
3332 -- Exclude odd case where we have two tag fields in the same
3333 -- record, both at location zero. This seems a bit strange, but
3334 -- it seems to happen in some circumstances, perhaps on an error.
3336 if Chars (C1_Ent) = Name_uTag
3338 Chars (C2_Ent) = Name_uTag
3343 -- Here we check if the two fields overlap
3346 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
3347 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
3348 E1 : constant Uint := S1 + Esize (C1_Ent);
3349 E2 : constant Uint := S2 + Esize (C2_Ent);
3352 if E2 <= S1 or else E1 <= S2 then
3355 Error_Msg_Node_2 := Component_Name (CC2);
3356 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
3357 Error_Msg_Node_1 := Component_Name (CC1);
3359 ("component& overlaps & #", Component_Name (CC1));
3360 Overlap_Detected := True;
3364 end Check_Component_Overlap;
3366 --------------------
3367 -- Find_Component --
3368 --------------------
3370 procedure Find_Component is
3372 procedure Search_Component (R : Entity_Id);
3373 -- Search components of R for a match. If found, Comp is set.
3375 ----------------------
3376 -- Search_Component --
3377 ----------------------
3379 procedure Search_Component (R : Entity_Id) is
3381 Comp := First_Component_Or_Discriminant (R);
3382 while Present (Comp) loop
3384 -- Ignore error of attribute name for component name (we
3385 -- already gave an error message for this, so no need to
3388 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
3391 exit when Chars (Comp) = Chars (Component_Name (CC));
3394 Next_Component_Or_Discriminant (Comp);
3396 end Search_Component;
3398 -- Start of processing for Find_Component
3401 -- Return with Comp set to Empty if we have a pragma
3403 if Nkind (CC) = N_Pragma then
3408 -- Search current record for matching component
3410 Search_Component (Rectype);
3412 -- If not found, maybe component of base type that is absent from
3413 -- statically constrained first subtype.
3416 Search_Component (Base_Type (Rectype));
3419 -- If no component, or the component does not reference the component
3420 -- clause in question, then there was some previous error for which
3421 -- we already gave a message, so just return with Comp Empty.
3424 or else Component_Clause (Comp) /= CC
3428 -- Normal case where we have a component clause
3431 Fbit := Component_Bit_Offset (Comp);
3432 Lbit := Fbit + Esize (Comp) - 1;
3436 -- Start of processing for Check_Record_Representation_Clause
3440 Rectype := Entity (Ident);
3442 if Rectype = Any_Type then
3445 Rectype := Underlying_Type (Rectype);
3448 -- See if we have a fully repped derived tagged type
3451 PS : constant Entity_Id := Parent_Subtype (Rectype);
3454 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
3455 Tagged_Parent := PS;
3457 -- Find maximum bit of any component of the parent type
3459 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
3460 Pcomp := First_Entity (Tagged_Parent);
3461 while Present (Pcomp) loop
3462 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
3463 if Component_Bit_Offset (Pcomp) /= No_Uint
3464 and then Known_Static_Esize (Pcomp)
3469 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
3472 Next_Entity (Pcomp);
3478 -- All done if no component clauses
3480 CC := First (Component_Clauses (N));
3486 -- If a tag is present, then create a component clause that places it
3487 -- at the start of the record (otherwise gigi may place it after other
3488 -- fields that have rep clauses).
3490 Fent := First_Entity (Rectype);
3492 if Nkind (Fent) = N_Defining_Identifier
3493 and then Chars (Fent) = Name_uTag
3495 Set_Component_Bit_Offset (Fent, Uint_0);
3496 Set_Normalized_Position (Fent, Uint_0);
3497 Set_Normalized_First_Bit (Fent, Uint_0);
3498 Set_Normalized_Position_Max (Fent, Uint_0);
3499 Init_Esize (Fent, System_Address_Size);
3501 Set_Component_Clause (Fent,
3502 Make_Component_Clause (Loc,
3504 Make_Identifier (Loc,
3505 Chars => Name_uTag),
3508 Make_Integer_Literal (Loc,
3512 Make_Integer_Literal (Loc,
3516 Make_Integer_Literal (Loc,
3517 UI_From_Int (System_Address_Size))));
3519 Ccount := Ccount + 1;
3522 Max_Bit_So_Far := Uint_Minus_1;
3523 Overlap_Check_Required := False;
3525 -- Process the component clauses
3527 while Present (CC) loop
3530 if Present (Comp) then
3531 Ccount := Ccount + 1;
3533 -- We need a full overlap check if record positions non-monotonic
3535 if Fbit <= Max_Bit_So_Far then
3536 Overlap_Check_Required := True;
3539 Max_Bit_So_Far := Lbit;
3541 -- Check bit position out of range of specified size
3543 if Has_Size_Clause (Rectype)
3544 and then Esize (Rectype) <= Lbit
3547 ("bit number out of range of specified size",
3550 -- Check for overlap with tag field
3553 if Is_Tagged_Type (Rectype)
3554 and then Fbit < System_Address_Size
3557 ("component overlaps tag field of&",
3558 Component_Name (CC), Rectype);
3559 Overlap_Detected := True;
3567 -- Check parent overlap if component might overlap parent field
3569 if Present (Tagged_Parent)
3570 and then Fbit <= Parent_Last_Bit
3572 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
3573 while Present (Pcomp) loop
3574 if not Is_Tag (Pcomp)
3575 and then Chars (Pcomp) /= Name_uParent
3577 Check_Component_Overlap (Comp, Pcomp);
3580 Next_Component_Or_Discriminant (Pcomp);
3588 -- Now that we have processed all the component clauses, check for
3589 -- overlap. We have to leave this till last, since the components can
3590 -- appear in any arbitrary order in the representation clause.
3592 -- We do not need this check if all specified ranges were monotonic,
3593 -- as recorded by Overlap_Check_Required being False at this stage.
3595 -- This first section checks if there are any overlapping entries at
3596 -- all. It does this by sorting all entries and then seeing if there are
3597 -- any overlaps. If there are none, then that is decisive, but if there
3598 -- are overlaps, they may still be OK (they may result from fields in
3599 -- different variants).
3601 if Overlap_Check_Required then
3602 Overlap_Check1 : declare
3604 OC_Fbit : array (0 .. Ccount) of Uint;
3605 -- First-bit values for component clauses, the value is the offset
3606 -- of the first bit of the field from start of record. The zero
3607 -- entry is for use in sorting.
3609 OC_Lbit : array (0 .. Ccount) of Uint;
3610 -- Last-bit values for component clauses, the value is the offset
3611 -- of the last bit of the field from start of record. The zero
3612 -- entry is for use in sorting.
3614 OC_Count : Natural := 0;
3615 -- Count of entries in OC_Fbit and OC_Lbit
3617 function OC_Lt (Op1, Op2 : Natural) return Boolean;
3618 -- Compare routine for Sort
3620 procedure OC_Move (From : Natural; To : Natural);
3621 -- Move routine for Sort
3623 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
3629 function OC_Lt (Op1, Op2 : Natural) return Boolean is
3631 return OC_Fbit (Op1) < OC_Fbit (Op2);
3638 procedure OC_Move (From : Natural; To : Natural) is
3640 OC_Fbit (To) := OC_Fbit (From);
3641 OC_Lbit (To) := OC_Lbit (From);
3644 -- Start of processing for Overlap_Check
3647 CC := First (Component_Clauses (N));
3648 while Present (CC) loop
3650 -- Exclude component clause already marked in error
3652 if not Error_Posted (CC) then
3655 if Present (Comp) then
3656 OC_Count := OC_Count + 1;
3657 OC_Fbit (OC_Count) := Fbit;
3658 OC_Lbit (OC_Count) := Lbit;
3665 Sorting.Sort (OC_Count);
3667 Overlap_Check_Required := False;
3668 for J in 1 .. OC_Count - 1 loop
3669 if OC_Lbit (J) >= OC_Fbit (J + 1) then
3670 Overlap_Check_Required := True;
3677 -- If Overlap_Check_Required is still True, then we have to do the full
3678 -- scale overlap check, since we have at least two fields that do
3679 -- overlap, and we need to know if that is OK since they are in
3680 -- different variant, or whether we have a definite problem.
3682 if Overlap_Check_Required then
3683 Overlap_Check2 : declare
3684 C1_Ent, C2_Ent : Entity_Id;
3685 -- Entities of components being checked for overlap
3688 -- Component_List node whose Component_Items are being checked
3691 -- Component declaration for component being checked
3694 C1_Ent := First_Entity (Base_Type (Rectype));
3696 -- Loop through all components in record. For each component check
3697 -- for overlap with any of the preceding elements on the component
3698 -- list containing the component and also, if the component is in
3699 -- a variant, check against components outside the case structure.
3700 -- This latter test is repeated recursively up the variant tree.
3702 Main_Component_Loop : while Present (C1_Ent) loop
3703 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
3704 goto Continue_Main_Component_Loop;
3707 -- Skip overlap check if entity has no declaration node. This
3708 -- happens with discriminants in constrained derived types.
3709 -- Possibly we are missing some checks as a result, but that
3710 -- does not seem terribly serious.
3712 if No (Declaration_Node (C1_Ent)) then
3713 goto Continue_Main_Component_Loop;
3716 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
3718 -- Loop through component lists that need checking. Check the
3719 -- current component list and all lists in variants above us.
3721 Component_List_Loop : loop
3723 -- If derived type definition, go to full declaration
3724 -- If at outer level, check discriminants if there are any.
3726 if Nkind (Clist) = N_Derived_Type_Definition then
3727 Clist := Parent (Clist);
3730 -- Outer level of record definition, check discriminants
3732 if Nkind_In (Clist, N_Full_Type_Declaration,
3733 N_Private_Type_Declaration)
3735 if Has_Discriminants (Defining_Identifier (Clist)) then
3737 First_Discriminant (Defining_Identifier (Clist));
3738 while Present (C2_Ent) loop
3739 exit when C1_Ent = C2_Ent;
3740 Check_Component_Overlap (C1_Ent, C2_Ent);
3741 Next_Discriminant (C2_Ent);
3745 -- Record extension case
3747 elsif Nkind (Clist) = N_Derived_Type_Definition then
3750 -- Otherwise check one component list
3753 Citem := First (Component_Items (Clist));
3754 while Present (Citem) loop
3755 if Nkind (Citem) = N_Component_Declaration then
3756 C2_Ent := Defining_Identifier (Citem);
3757 exit when C1_Ent = C2_Ent;
3758 Check_Component_Overlap (C1_Ent, C2_Ent);
3765 -- Check for variants above us (the parent of the Clist can
3766 -- be a variant, in which case its parent is a variant part,
3767 -- and the parent of the variant part is a component list
3768 -- whose components must all be checked against the current
3769 -- component for overlap).
3771 if Nkind (Parent (Clist)) = N_Variant then
3772 Clist := Parent (Parent (Parent (Clist)));
3774 -- Check for possible discriminant part in record, this
3775 -- is treated essentially as another level in the
3776 -- recursion. For this case the parent of the component
3777 -- list is the record definition, and its parent is the
3778 -- full type declaration containing the discriminant
3781 elsif Nkind (Parent (Clist)) = N_Record_Definition then
3782 Clist := Parent (Parent ((Clist)));
3784 -- If neither of these two cases, we are at the top of
3788 exit Component_List_Loop;
3790 end loop Component_List_Loop;
3792 <<Continue_Main_Component_Loop>>
3793 Next_Entity (C1_Ent);
3795 end loop Main_Component_Loop;
3799 -- The following circuit deals with warning on record holes (gaps). We
3800 -- skip this check if overlap was detected, since it makes sense for the
3801 -- programmer to fix this illegality before worrying about warnings.
3803 if not Overlap_Detected and Warn_On_Record_Holes then
3804 Record_Hole_Check : declare
3805 Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype));
3806 -- Full declaration of record type
3808 procedure Check_Component_List
3812 -- Check component list CL for holes. The starting bit should be
3813 -- Sbit. which is zero for the main record component list and set
3814 -- appropriately for recursive calls for variants. DS is set to
3815 -- a list of discriminant specifications to be included in the
3816 -- consideration of components. It is No_List if none to consider.
3818 --------------------------
3819 -- Check_Component_List --
3820 --------------------------
3822 procedure Check_Component_List
3830 Compl := Integer (List_Length (Component_Items (CL)));
3832 if DS /= No_List then
3833 Compl := Compl + Integer (List_Length (DS));
3837 Comps : array (Natural range 0 .. Compl) of Entity_Id;
3838 -- Gather components (zero entry is for sort routine)
3840 Ncomps : Natural := 0;
3841 -- Number of entries stored in Comps (starting at Comps (1))
3844 -- One component item or discriminant specification
3847 -- Starting bit for next component
3855 function Lt (Op1, Op2 : Natural) return Boolean;
3856 -- Compare routine for Sort
3858 procedure Move (From : Natural; To : Natural);
3859 -- Move routine for Sort
3861 package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
3867 function Lt (Op1, Op2 : Natural) return Boolean is
3869 return Component_Bit_Offset (Comps (Op1))
3871 Component_Bit_Offset (Comps (Op2));
3878 procedure Move (From : Natural; To : Natural) is
3880 Comps (To) := Comps (From);
3884 -- Gather discriminants into Comp
3886 if DS /= No_List then
3887 Citem := First (DS);
3888 while Present (Citem) loop
3889 if Nkind (Citem) = N_Discriminant_Specification then
3891 Ent : constant Entity_Id :=
3892 Defining_Identifier (Citem);
3894 if Ekind (Ent) = E_Discriminant then
3895 Ncomps := Ncomps + 1;
3896 Comps (Ncomps) := Ent;
3905 -- Gather component entities into Comp
3907 Citem := First (Component_Items (CL));
3908 while Present (Citem) loop
3909 if Nkind (Citem) = N_Component_Declaration then
3910 Ncomps := Ncomps + 1;
3911 Comps (Ncomps) := Defining_Identifier (Citem);
3917 -- Now sort the component entities based on the first bit.
3918 -- Note we already know there are no overlapping components.
3920 Sorting.Sort (Ncomps);
3922 -- Loop through entries checking for holes
3925 for J in 1 .. Ncomps loop
3927 Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
3929 if Error_Msg_Uint_1 > 0 then
3931 ("?^-bit gap before component&",
3932 Component_Name (Component_Clause (CEnt)), CEnt);
3935 Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
3938 -- Process variant parts recursively if present
3940 if Present (Variant_Part (CL)) then
3941 Variant := First (Variants (Variant_Part (CL)));
3942 while Present (Variant) loop
3943 Check_Component_List
3944 (Component_List (Variant), Nbit, No_List);
3949 end Check_Component_List;
3951 -- Start of processing for Record_Hole_Check
3958 if Is_Tagged_Type (Rectype) then
3959 Sbit := UI_From_Int (System_Address_Size);
3964 if Nkind (Decl) = N_Full_Type_Declaration
3965 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
3967 Check_Component_List
3968 (Component_List (Type_Definition (Decl)),
3970 Discriminant_Specifications (Decl));
3973 end Record_Hole_Check;
3976 -- For records that have component clauses for all components, and whose
3977 -- size is less than or equal to 32, we need to know the size in the
3978 -- front end to activate possible packed array processing where the
3979 -- component type is a record.
3981 -- At this stage Hbit + 1 represents the first unused bit from all the
3982 -- component clauses processed, so if the component clauses are
3983 -- complete, then this is the length of the record.
3985 -- For records longer than System.Storage_Unit, and for those where not
3986 -- all components have component clauses, the back end determines the
3987 -- length (it may for example be appropriate to round up the size
3988 -- to some convenient boundary, based on alignment considerations, etc).
3990 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
3992 -- Nothing to do if at least one component has no component clause
3994 Comp := First_Component_Or_Discriminant (Rectype);
3995 while Present (Comp) loop
3996 exit when No (Component_Clause (Comp));
3997 Next_Component_Or_Discriminant (Comp);
4000 -- If we fall out of loop, all components have component clauses
4001 -- and so we can set the size to the maximum value.
4004 Set_RM_Size (Rectype, Hbit + 1);
4007 end Check_Record_Representation_Clause;
4013 procedure Check_Size
4017 Biased : out Boolean)
4019 UT : constant Entity_Id := Underlying_Type (T);
4025 -- Dismiss cases for generic types or types with previous errors
4028 or else UT = Any_Type
4029 or else Is_Generic_Type (UT)
4030 or else Is_Generic_Type (Root_Type (UT))
4034 -- Check case of bit packed array
4036 elsif Is_Array_Type (UT)
4037 and then Known_Static_Component_Size (UT)
4038 and then Is_Bit_Packed_Array (UT)
4046 Asiz := Component_Size (UT);
4047 Indx := First_Index (UT);
4049 Ityp := Etype (Indx);
4051 -- If non-static bound, then we are not in the business of
4052 -- trying to check the length, and indeed an error will be
4053 -- issued elsewhere, since sizes of non-static array types
4054 -- cannot be set implicitly or explicitly.
4056 if not Is_Static_Subtype (Ityp) then
4060 -- Otherwise accumulate next dimension
4062 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
4063 Expr_Value (Type_Low_Bound (Ityp)) +
4067 exit when No (Indx);
4073 Error_Msg_Uint_1 := Asiz;
4075 ("size for& too small, minimum allowed is ^", N, T);
4076 Set_Esize (T, Asiz);
4077 Set_RM_Size (T, Asiz);
4081 -- All other composite types are ignored
4083 elsif Is_Composite_Type (UT) then
4086 -- For fixed-point types, don't check minimum if type is not frozen,
4087 -- since we don't know all the characteristics of the type that can
4088 -- affect the size (e.g. a specified small) till freeze time.
4090 elsif Is_Fixed_Point_Type (UT)
4091 and then not Is_Frozen (UT)
4095 -- Cases for which a minimum check is required
4098 -- Ignore if specified size is correct for the type
4100 if Known_Esize (UT) and then Siz = Esize (UT) then
4104 -- Otherwise get minimum size
4106 M := UI_From_Int (Minimum_Size (UT));
4110 -- Size is less than minimum size, but one possibility remains
4111 -- that we can manage with the new size if we bias the type.
4113 M := UI_From_Int (Minimum_Size (UT, Biased => True));
4116 Error_Msg_Uint_1 := M;
4118 ("size for& too small, minimum allowed is ^", N, T);
4128 -------------------------
4129 -- Get_Alignment_Value --
4130 -------------------------
4132 function Get_Alignment_Value (Expr : Node_Id) return Uint is
4133 Align : constant Uint := Static_Integer (Expr);
4136 if Align = No_Uint then
4139 elsif Align <= 0 then
4140 Error_Msg_N ("alignment value must be positive", Expr);
4144 for J in Int range 0 .. 64 loop
4146 M : constant Uint := Uint_2 ** J;
4149 exit when M = Align;
4153 ("alignment value must be power of 2", Expr);
4161 end Get_Alignment_Value;
4167 procedure Initialize is
4169 Unchecked_Conversions.Init;
4172 -------------------------
4173 -- Is_Operational_Item --
4174 -------------------------
4176 function Is_Operational_Item (N : Node_Id) return Boolean is
4178 if Nkind (N) /= N_Attribute_Definition_Clause then
4182 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
4184 return Id = Attribute_Input
4185 or else Id = Attribute_Output
4186 or else Id = Attribute_Read
4187 or else Id = Attribute_Write
4188 or else Id = Attribute_External_Tag;
4191 end Is_Operational_Item;
4197 function Minimum_Size
4199 Biased : Boolean := False) return Nat
4201 Lo : Uint := No_Uint;
4202 Hi : Uint := No_Uint;
4203 LoR : Ureal := No_Ureal;
4204 HiR : Ureal := No_Ureal;
4205 LoSet : Boolean := False;
4206 HiSet : Boolean := False;
4210 R_Typ : constant Entity_Id := Root_Type (T);
4213 -- If bad type, return 0
4215 if T = Any_Type then
4218 -- For generic types, just return zero. There cannot be any legitimate
4219 -- need to know such a size, but this routine may be called with a
4220 -- generic type as part of normal processing.
4222 elsif Is_Generic_Type (R_Typ)
4223 or else R_Typ = Any_Type
4227 -- Access types. Normally an access type cannot have a size smaller
4228 -- than the size of System.Address. The exception is on VMS, where
4229 -- we have short and long addresses, and it is possible for an access
4230 -- type to have a short address size (and thus be less than the size
4231 -- of System.Address itself). We simply skip the check for VMS, and
4232 -- leave it to the back end to do the check.
4234 elsif Is_Access_Type (T) then
4235 if OpenVMS_On_Target then
4238 return System_Address_Size;
4241 -- Floating-point types
4243 elsif Is_Floating_Point_Type (T) then
4244 return UI_To_Int (Esize (R_Typ));
4248 elsif Is_Discrete_Type (T) then
4250 -- The following loop is looking for the nearest compile time known
4251 -- bounds following the ancestor subtype chain. The idea is to find
4252 -- the most restrictive known bounds information.
4256 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4261 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
4262 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
4269 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
4270 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
4276 Ancest := Ancestor_Subtype (Ancest);
4279 Ancest := Base_Type (T);
4281 if Is_Generic_Type (Ancest) then
4287 -- Fixed-point types. We can't simply use Expr_Value to get the
4288 -- Corresponding_Integer_Value values of the bounds, since these do not
4289 -- get set till the type is frozen, and this routine can be called
4290 -- before the type is frozen. Similarly the test for bounds being static
4291 -- needs to include the case where we have unanalyzed real literals for
4294 elsif Is_Fixed_Point_Type (T) then
4296 -- The following loop is looking for the nearest compile time known
4297 -- bounds following the ancestor subtype chain. The idea is to find
4298 -- the most restrictive known bounds information.
4302 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
4306 -- Note: In the following two tests for LoSet and HiSet, it may
4307 -- seem redundant to test for N_Real_Literal here since normally
4308 -- one would assume that the test for the value being known at
4309 -- compile time includes this case. However, there is a glitch.
4310 -- If the real literal comes from folding a non-static expression,
4311 -- then we don't consider any non- static expression to be known
4312 -- at compile time if we are in configurable run time mode (needed
4313 -- in some cases to give a clearer definition of what is and what
4314 -- is not accepted). So the test is indeed needed. Without it, we
4315 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
4318 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
4319 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
4321 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
4328 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
4329 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
4331 HiR := Expr_Value_R (Type_High_Bound (Ancest));
4337 Ancest := Ancestor_Subtype (Ancest);
4340 Ancest := Base_Type (T);
4342 if Is_Generic_Type (Ancest) then
4348 Lo := UR_To_Uint (LoR / Small_Value (T));
4349 Hi := UR_To_Uint (HiR / Small_Value (T));
4351 -- No other types allowed
4354 raise Program_Error;
4357 -- Fall through with Hi and Lo set. Deal with biased case
4360 and then not Is_Fixed_Point_Type (T)
4361 and then not (Is_Enumeration_Type (T)
4362 and then Has_Non_Standard_Rep (T)))
4363 or else Has_Biased_Representation (T)
4369 -- Signed case. Note that we consider types like range 1 .. -1 to be
4370 -- signed for the purpose of computing the size, since the bounds have
4371 -- to be accommodated in the base type.
4373 if Lo < 0 or else Hi < 0 then
4377 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
4378 -- Note that we accommodate the case where the bounds cross. This
4379 -- can happen either because of the way the bounds are declared
4380 -- or because of the algorithm in Freeze_Fixed_Point_Type.
4394 -- If both bounds are positive, make sure that both are represen-
4395 -- table in the case where the bounds are crossed. This can happen
4396 -- either because of the way the bounds are declared, or because of
4397 -- the algorithm in Freeze_Fixed_Point_Type.
4403 -- S = size, (can accommodate 0 .. (2**size - 1))
4406 while Hi >= Uint_2 ** S loop
4414 ---------------------------
4415 -- New_Stream_Subprogram --
4416 ---------------------------
4418 procedure New_Stream_Subprogram
4422 Nam : TSS_Name_Type)
4424 Loc : constant Source_Ptr := Sloc (N);
4425 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
4426 Subp_Id : Entity_Id;
4427 Subp_Decl : Node_Id;
4431 Defer_Declaration : constant Boolean :=
4432 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
4433 -- For a tagged type, there is a declaration for each stream attribute
4434 -- at the freeze point, and we must generate only a completion of this
4435 -- declaration. We do the same for private types, because the full view
4436 -- might be tagged. Otherwise we generate a declaration at the point of
4437 -- the attribute definition clause.
4439 function Build_Spec return Node_Id;
4440 -- Used for declaration and renaming declaration, so that this is
4441 -- treated as a renaming_as_body.
4447 function Build_Spec return Node_Id is
4448 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
4451 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
4454 Subp_Id := Make_Defining_Identifier (Loc, Sname);
4456 -- S : access Root_Stream_Type'Class
4458 Formals := New_List (
4459 Make_Parameter_Specification (Loc,
4460 Defining_Identifier =>
4461 Make_Defining_Identifier (Loc, Name_S),
4463 Make_Access_Definition (Loc,
4466 Designated_Type (Etype (F)), Loc))));
4468 if Nam = TSS_Stream_Input then
4469 Spec := Make_Function_Specification (Loc,
4470 Defining_Unit_Name => Subp_Id,
4471 Parameter_Specifications => Formals,
4472 Result_Definition => T_Ref);
4477 Make_Parameter_Specification (Loc,
4478 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
4479 Out_Present => Out_P,
4480 Parameter_Type => T_Ref));
4483 Make_Procedure_Specification (Loc,
4484 Defining_Unit_Name => Subp_Id,
4485 Parameter_Specifications => Formals);
4491 -- Start of processing for New_Stream_Subprogram
4494 F := First_Formal (Subp);
4496 if Ekind (Subp) = E_Procedure then
4497 Etyp := Etype (Next_Formal (F));
4499 Etyp := Etype (Subp);
4502 -- Prepare subprogram declaration and insert it as an action on the
4503 -- clause node. The visibility for this entity is used to test for
4504 -- visibility of the attribute definition clause (in the sense of
4505 -- 8.3(23) as amended by AI-195).
4507 if not Defer_Declaration then
4509 Make_Subprogram_Declaration (Loc,
4510 Specification => Build_Spec);
4512 -- For a tagged type, there is always a visible declaration for each
4513 -- stream TSS (it is a predefined primitive operation), and the
4514 -- completion of this declaration occurs at the freeze point, which is
4515 -- not always visible at places where the attribute definition clause is
4516 -- visible. So, we create a dummy entity here for the purpose of
4517 -- tracking the visibility of the attribute definition clause itself.
4521 Make_Defining_Identifier (Loc,
4522 Chars => New_External_Name (Sname, 'V'));
4524 Make_Object_Declaration (Loc,
4525 Defining_Identifier => Subp_Id,
4526 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
4529 Insert_Action (N, Subp_Decl);
4530 Set_Entity (N, Subp_Id);
4533 Make_Subprogram_Renaming_Declaration (Loc,
4534 Specification => Build_Spec,
4535 Name => New_Reference_To (Subp, Loc));
4537 if Defer_Declaration then
4538 Set_TSS (Base_Type (Ent), Subp_Id);
4540 Insert_Action (N, Subp_Decl);
4541 Copy_TSS (Subp_Id, Base_Type (Ent));
4543 end New_Stream_Subprogram;
4545 ------------------------
4546 -- Rep_Item_Too_Early --
4547 ------------------------
4549 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
4551 -- Cannot apply non-operational rep items to generic types
4553 if Is_Operational_Item (N) then
4557 and then Is_Generic_Type (Root_Type (T))
4559 Error_Msg_N ("representation item not allowed for generic type", N);
4563 -- Otherwise check for incomplete type
4565 if Is_Incomplete_Or_Private_Type (T)
4566 and then No (Underlying_Type (T))
4569 ("representation item must be after full type declaration", N);
4572 -- If the type has incomplete components, a representation clause is
4573 -- illegal but stream attributes and Convention pragmas are correct.
4575 elsif Has_Private_Component (T) then
4576 if Nkind (N) = N_Pragma then
4580 ("representation item must appear after type is fully defined",
4587 end Rep_Item_Too_Early;
4589 -----------------------
4590 -- Rep_Item_Too_Late --
4591 -----------------------
4593 function Rep_Item_Too_Late
4596 FOnly : Boolean := False) return Boolean
4599 Parent_Type : Entity_Id;
4602 -- Output the too late message. Note that this is not considered a
4603 -- serious error, since the effect is simply that we ignore the
4604 -- representation clause in this case.
4610 procedure Too_Late is
4612 Error_Msg_N ("|representation item appears too late!", N);
4615 -- Start of processing for Rep_Item_Too_Late
4618 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
4619 -- types, which may be frozen if they appear in a representation clause
4620 -- for a local type.
4623 and then not From_With_Type (T)
4626 S := First_Subtype (T);
4628 if Present (Freeze_Node (S)) then
4630 ("?no more representation items for }", Freeze_Node (S), S);
4635 -- Check for case of non-tagged derived type whose parent either has
4636 -- primitive operations, or is a by reference type (RM 13.1(10)).
4640 and then Is_Derived_Type (T)
4641 and then not Is_Tagged_Type (T)
4643 Parent_Type := Etype (Base_Type (T));
4645 if Has_Primitive_Operations (Parent_Type) then
4648 ("primitive operations already defined for&!", N, Parent_Type);
4651 elsif Is_By_Reference_Type (Parent_Type) then
4654 ("parent type & is a by reference type!", N, Parent_Type);
4659 -- No error, link item into head of chain of rep items for the entity,
4660 -- but avoid chaining if we have an overloadable entity, and the pragma
4661 -- is one that can apply to multiple overloaded entities.
4663 if Is_Overloadable (T)
4664 and then Nkind (N) = N_Pragma
4667 Pname : constant Name_Id := Pragma_Name (N);
4669 if Pname = Name_Convention or else
4670 Pname = Name_Import or else
4671 Pname = Name_Export or else
4672 Pname = Name_External or else
4673 Pname = Name_Interface
4680 Record_Rep_Item (T, N);
4682 end Rep_Item_Too_Late;
4684 -------------------------
4685 -- Same_Representation --
4686 -------------------------
4688 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
4689 T1 : constant Entity_Id := Underlying_Type (Typ1);
4690 T2 : constant Entity_Id := Underlying_Type (Typ2);
4693 -- A quick check, if base types are the same, then we definitely have
4694 -- the same representation, because the subtype specific representation
4695 -- attributes (Size and Alignment) do not affect representation from
4696 -- the point of view of this test.
4698 if Base_Type (T1) = Base_Type (T2) then
4701 elsif Is_Private_Type (Base_Type (T2))
4702 and then Base_Type (T1) = Full_View (Base_Type (T2))
4707 -- Tagged types never have differing representations
4709 if Is_Tagged_Type (T1) then
4713 -- Representations are definitely different if conventions differ
4715 if Convention (T1) /= Convention (T2) then
4719 -- Representations are different if component alignments differ
4721 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4723 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4724 and then Component_Alignment (T1) /= Component_Alignment (T2)
4729 -- For arrays, the only real issue is component size. If we know the
4730 -- component size for both arrays, and it is the same, then that's
4731 -- good enough to know we don't have a change of representation.
4733 if Is_Array_Type (T1) then
4734 if Known_Component_Size (T1)
4735 and then Known_Component_Size (T2)
4736 and then Component_Size (T1) = Component_Size (T2)
4742 -- Types definitely have same representation if neither has non-standard
4743 -- representation since default representations are always consistent.
4744 -- If only one has non-standard representation, and the other does not,
4745 -- then we consider that they do not have the same representation. They
4746 -- might, but there is no way of telling early enough.
4748 if Has_Non_Standard_Rep (T1) then
4749 if not Has_Non_Standard_Rep (T2) then
4753 return not Has_Non_Standard_Rep (T2);
4756 -- Here the two types both have non-standard representation, and we need
4757 -- to determine if they have the same non-standard representation.
4759 -- For arrays, we simply need to test if the component sizes are the
4760 -- same. Pragma Pack is reflected in modified component sizes, so this
4761 -- check also deals with pragma Pack.
4763 if Is_Array_Type (T1) then
4764 return Component_Size (T1) = Component_Size (T2);
4766 -- Tagged types always have the same representation, because it is not
4767 -- possible to specify different representations for common fields.
4769 elsif Is_Tagged_Type (T1) then
4772 -- Case of record types
4774 elsif Is_Record_Type (T1) then
4776 -- Packed status must conform
4778 if Is_Packed (T1) /= Is_Packed (T2) then
4781 -- Otherwise we must check components. Typ2 maybe a constrained
4782 -- subtype with fewer components, so we compare the components
4783 -- of the base types.
4786 Record_Case : declare
4787 CD1, CD2 : Entity_Id;
4789 function Same_Rep return Boolean;
4790 -- CD1 and CD2 are either components or discriminants. This
4791 -- function tests whether the two have the same representation
4797 function Same_Rep return Boolean is
4799 if No (Component_Clause (CD1)) then
4800 return No (Component_Clause (CD2));
4804 Present (Component_Clause (CD2))
4806 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4808 Esize (CD1) = Esize (CD2);
4812 -- Start of processing for Record_Case
4815 if Has_Discriminants (T1) then
4816 CD1 := First_Discriminant (T1);
4817 CD2 := First_Discriminant (T2);
4819 -- The number of discriminants may be different if the
4820 -- derived type has fewer (constrained by values). The
4821 -- invisible discriminants retain the representation of
4822 -- the original, so the discrepancy does not per se
4823 -- indicate a different representation.
4826 and then Present (CD2)
4828 if not Same_Rep then
4831 Next_Discriminant (CD1);
4832 Next_Discriminant (CD2);
4837 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4838 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4840 while Present (CD1) loop
4841 if not Same_Rep then
4844 Next_Component (CD1);
4845 Next_Component (CD2);
4853 -- For enumeration types, we must check each literal to see if the
4854 -- representation is the same. Note that we do not permit enumeration
4855 -- representation clauses for Character and Wide_Character, so these
4856 -- cases were already dealt with.
4858 elsif Is_Enumeration_Type (T1) then
4860 Enumeration_Case : declare
4864 L1 := First_Literal (T1);
4865 L2 := First_Literal (T2);
4867 while Present (L1) loop
4868 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4878 end Enumeration_Case;
4880 -- Any other types have the same representation for these purposes
4885 end Same_Representation;
4887 --------------------
4888 -- Set_Enum_Esize --
4889 --------------------
4891 procedure Set_Enum_Esize (T : Entity_Id) is
4899 -- Find the minimum standard size (8,16,32,64) that fits
4901 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4902 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4905 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4906 Sz := Standard_Character_Size; -- May be > 8 on some targets
4908 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4911 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4914 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4919 if Hi < Uint_2**08 then
4920 Sz := Standard_Character_Size; -- May be > 8 on some targets
4922 elsif Hi < Uint_2**16 then
4925 elsif Hi < Uint_2**32 then
4928 else pragma Assert (Hi < Uint_2**63);
4933 -- That minimum is the proper size unless we have a foreign convention
4934 -- and the size required is 32 or less, in which case we bump the size
4935 -- up to 32. This is required for C and C++ and seems reasonable for
4936 -- all other foreign conventions.
4938 if Has_Foreign_Convention (T)
4939 and then Esize (T) < Standard_Integer_Size
4941 Init_Esize (T, Standard_Integer_Size);
4947 ------------------------------
4948 -- Validate_Address_Clauses --
4949 ------------------------------
4951 procedure Validate_Address_Clauses is
4953 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4955 ACCR : Address_Clause_Check_Record
4956 renames Address_Clause_Checks.Table (J);
4967 -- Skip processing of this entry if warning already posted
4969 if not Address_Warning_Posted (ACCR.N) then
4971 Expr := Original_Node (Expression (ACCR.N));
4975 X_Alignment := Alignment (ACCR.X);
4976 Y_Alignment := Alignment (ACCR.Y);
4978 -- Similarly obtain sizes
4980 X_Size := Esize (ACCR.X);
4981 Y_Size := Esize (ACCR.Y);
4983 -- Check for large object overlaying smaller one
4986 and then X_Size > Uint_0
4987 and then X_Size > Y_Size
4990 ("?& overlays smaller object", ACCR.N, ACCR.X);
4992 ("\?program execution may be erroneous", ACCR.N);
4993 Error_Msg_Uint_1 := X_Size;
4995 ("\?size of & is ^", ACCR.N, ACCR.X);
4996 Error_Msg_Uint_1 := Y_Size;
4998 ("\?size of & is ^", ACCR.N, ACCR.Y);
5000 -- Check for inadequate alignment, both of the base object
5001 -- and of the offset, if any.
5003 -- Note: we do not check the alignment if we gave a size
5004 -- warning, since it would likely be redundant.
5006 elsif Y_Alignment /= Uint_0
5007 and then (Y_Alignment < X_Alignment
5010 Nkind (Expr) = N_Attribute_Reference
5012 Attribute_Name (Expr) = Name_Address
5014 Has_Compatible_Alignment
5015 (ACCR.X, Prefix (Expr))
5016 /= Known_Compatible))
5019 ("?specified address for& may be inconsistent "
5023 ("\?program execution may be erroneous (RM 13.3(27))",
5025 Error_Msg_Uint_1 := X_Alignment;
5027 ("\?alignment of & is ^",
5029 Error_Msg_Uint_1 := Y_Alignment;
5031 ("\?alignment of & is ^",
5033 if Y_Alignment >= X_Alignment then
5035 ("\?but offset is not multiple of alignment",
5042 end Validate_Address_Clauses;
5044 -----------------------------------
5045 -- Validate_Unchecked_Conversion --
5046 -----------------------------------
5048 procedure Validate_Unchecked_Conversion
5050 Act_Unit : Entity_Id)
5057 -- Obtain source and target types. Note that we call Ancestor_Subtype
5058 -- here because the processing for generic instantiation always makes
5059 -- subtypes, and we want the original frozen actual types.
5061 -- If we are dealing with private types, then do the check on their
5062 -- fully declared counterparts if the full declarations have been
5063 -- encountered (they don't have to be visible, but they must exist!)
5065 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
5067 if Is_Private_Type (Source)
5068 and then Present (Underlying_Type (Source))
5070 Source := Underlying_Type (Source);
5073 Target := Ancestor_Subtype (Etype (Act_Unit));
5075 -- If either type is generic, the instantiation happens within a generic
5076 -- unit, and there is nothing to check. The proper check
5077 -- will happen when the enclosing generic is instantiated.
5079 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
5083 if Is_Private_Type (Target)
5084 and then Present (Underlying_Type (Target))
5086 Target := Underlying_Type (Target);
5089 -- Source may be unconstrained array, but not target
5091 if Is_Array_Type (Target)
5092 and then not Is_Constrained (Target)
5095 ("unchecked conversion to unconstrained array not allowed", N);
5099 -- Warn if conversion between two different convention pointers
5101 if Is_Access_Type (Target)
5102 and then Is_Access_Type (Source)
5103 and then Convention (Target) /= Convention (Source)
5104 and then Warn_On_Unchecked_Conversion
5106 -- Give warnings for subprogram pointers only on most targets. The
5107 -- exception is VMS, where data pointers can have different lengths
5108 -- depending on the pointer convention.
5110 if Is_Access_Subprogram_Type (Target)
5111 or else Is_Access_Subprogram_Type (Source)
5112 or else OpenVMS_On_Target
5115 ("?conversion between pointers with different conventions!", N);
5119 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
5120 -- warning when compiling GNAT-related sources.
5122 if Warn_On_Unchecked_Conversion
5123 and then not In_Predefined_Unit (N)
5124 and then RTU_Loaded (Ada_Calendar)
5126 (Chars (Source) = Name_Time
5128 Chars (Target) = Name_Time)
5130 -- If Ada.Calendar is loaded and the name of one of the operands is
5131 -- Time, there is a good chance that this is Ada.Calendar.Time.
5134 Calendar_Time : constant Entity_Id :=
5135 Full_View (RTE (RO_CA_Time));
5137 pragma Assert (Present (Calendar_Time));
5139 if Source = Calendar_Time
5140 or else Target = Calendar_Time
5143 ("?representation of 'Time values may change between " &
5144 "'G'N'A'T versions", N);
5149 -- Make entry in unchecked conversion table for later processing by
5150 -- Validate_Unchecked_Conversions, which will check sizes and alignments
5151 -- (using values set by the back-end where possible). This is only done
5152 -- if the appropriate warning is active.
5154 if Warn_On_Unchecked_Conversion then
5155 Unchecked_Conversions.Append
5156 (New_Val => UC_Entry'
5161 -- If both sizes are known statically now, then back end annotation
5162 -- is not required to do a proper check but if either size is not
5163 -- known statically, then we need the annotation.
5165 if Known_Static_RM_Size (Source)
5166 and then Known_Static_RM_Size (Target)
5170 Back_Annotate_Rep_Info := True;
5174 -- If unchecked conversion to access type, and access type is declared
5175 -- in the same unit as the unchecked conversion, then set the
5176 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
5179 if Is_Access_Type (Target) and then
5180 In_Same_Source_Unit (Target, N)
5182 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
5185 -- Generate N_Validate_Unchecked_Conversion node for back end in
5186 -- case the back end needs to perform special validation checks.
5188 -- Shouldn't this be in Exp_Ch13, since the check only gets done
5189 -- if we have full expansion and the back end is called ???
5192 Make_Validate_Unchecked_Conversion (Sloc (N));
5193 Set_Source_Type (Vnode, Source);
5194 Set_Target_Type (Vnode, Target);
5196 -- If the unchecked conversion node is in a list, just insert before it.
5197 -- If not we have some strange case, not worth bothering about.
5199 if Is_List_Member (N) then
5200 Insert_After (N, Vnode);
5202 end Validate_Unchecked_Conversion;
5204 ------------------------------------
5205 -- Validate_Unchecked_Conversions --
5206 ------------------------------------
5208 procedure Validate_Unchecked_Conversions is
5210 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
5212 T : UC_Entry renames Unchecked_Conversions.Table (N);
5214 Eloc : constant Source_Ptr := T.Eloc;
5215 Source : constant Entity_Id := T.Source;
5216 Target : constant Entity_Id := T.Target;
5222 -- This validation check, which warns if we have unequal sizes for
5223 -- unchecked conversion, and thus potentially implementation
5224 -- dependent semantics, is one of the few occasions on which we
5225 -- use the official RM size instead of Esize. See description in
5226 -- Einfo "Handling of Type'Size Values" for details.
5228 if Serious_Errors_Detected = 0
5229 and then Known_Static_RM_Size (Source)
5230 and then Known_Static_RM_Size (Target)
5232 -- Don't do the check if warnings off for either type, note the
5233 -- deliberate use of OR here instead of OR ELSE to get the flag
5234 -- Warnings_Off_Used set for both types if appropriate.
5236 and then not (Has_Warnings_Off (Source)
5238 Has_Warnings_Off (Target))
5240 Source_Siz := RM_Size (Source);
5241 Target_Siz := RM_Size (Target);
5243 if Source_Siz /= Target_Siz then
5245 ("?types for unchecked conversion have different sizes!",
5248 if All_Errors_Mode then
5249 Error_Msg_Name_1 := Chars (Source);
5250 Error_Msg_Uint_1 := Source_Siz;
5251 Error_Msg_Name_2 := Chars (Target);
5252 Error_Msg_Uint_2 := Target_Siz;
5253 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
5255 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
5257 if Is_Discrete_Type (Source)
5258 and then Is_Discrete_Type (Target)
5260 if Source_Siz > Target_Siz then
5262 ("\?^ high order bits of source will be ignored!",
5265 elsif Is_Unsigned_Type (Source) then
5267 ("\?source will be extended with ^ high order " &
5268 "zero bits?!", Eloc);
5272 ("\?source will be extended with ^ high order " &
5277 elsif Source_Siz < Target_Siz then
5278 if Is_Discrete_Type (Target) then
5279 if Bytes_Big_Endian then
5281 ("\?target value will include ^ undefined " &
5286 ("\?target value will include ^ undefined " &
5293 ("\?^ trailing bits of target value will be " &
5294 "undefined!", Eloc);
5297 else pragma Assert (Source_Siz > Target_Siz);
5299 ("\?^ trailing bits of source will be ignored!",
5306 -- If both types are access types, we need to check the alignment.
5307 -- If the alignment of both is specified, we can do it here.
5309 if Serious_Errors_Detected = 0
5310 and then Ekind (Source) in Access_Kind
5311 and then Ekind (Target) in Access_Kind
5312 and then Target_Strict_Alignment
5313 and then Present (Designated_Type (Source))
5314 and then Present (Designated_Type (Target))
5317 D_Source : constant Entity_Id := Designated_Type (Source);
5318 D_Target : constant Entity_Id := Designated_Type (Target);
5321 if Known_Alignment (D_Source)
5322 and then Known_Alignment (D_Target)
5325 Source_Align : constant Uint := Alignment (D_Source);
5326 Target_Align : constant Uint := Alignment (D_Target);
5329 if Source_Align < Target_Align
5330 and then not Is_Tagged_Type (D_Source)
5332 -- Suppress warning if warnings suppressed on either
5333 -- type or either designated type. Note the use of
5334 -- OR here instead of OR ELSE. That is intentional,
5335 -- we would like to set flag Warnings_Off_Used in
5336 -- all types for which warnings are suppressed.
5338 and then not (Has_Warnings_Off (D_Source)
5340 Has_Warnings_Off (D_Target)
5342 Has_Warnings_Off (Source)
5344 Has_Warnings_Off (Target))
5346 Error_Msg_Uint_1 := Target_Align;
5347 Error_Msg_Uint_2 := Source_Align;
5348 Error_Msg_Node_1 := D_Target;
5349 Error_Msg_Node_2 := D_Source;
5351 ("?alignment of & (^) is stricter than " &
5352 "alignment of & (^)!", Eloc);
5354 ("\?resulting access value may have invalid " &
5355 "alignment!", Eloc);
5363 end Validate_Unchecked_Conversions;