1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Errout; use Errout;
30 with Exp_Tss; use Exp_Tss;
31 with Exp_Util; use Exp_Util;
33 with Lib.Xref; use Lib.Xref;
34 with Namet; use Namet;
35 with Nlists; use Nlists;
36 with Nmake; use Nmake;
38 with Restrict; use Restrict;
39 with Rident; use Rident;
40 with Rtsfind; use Rtsfind;
42 with Sem_Aux; use Sem_Aux;
43 with Sem_Ch8; use Sem_Ch8;
44 with Sem_Eval; use Sem_Eval;
45 with Sem_Res; use Sem_Res;
46 with Sem_Type; use Sem_Type;
47 with Sem_Util; use Sem_Util;
48 with Sem_Warn; use Sem_Warn;
49 with Snames; use Snames;
50 with Stand; use Stand;
51 with Sinfo; use Sinfo;
53 with Targparm; use Targparm;
54 with Ttypes; use Ttypes;
55 with Tbuild; use Tbuild;
56 with Urealp; use Urealp;
58 with GNAT.Heap_Sort_G;
60 package body Sem_Ch13 is
62 SSU : constant Pos := System_Storage_Unit;
63 -- Convenient short hand for commonly used constant
65 -----------------------
66 -- Local Subprograms --
67 -----------------------
69 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
70 -- This routine is called after setting the Esize of type entity Typ.
71 -- The purpose is to deal with the situation where an alignment has been
72 -- inherited from a derived type that is no longer appropriate for the
73 -- new Esize value. In this case, we reset the Alignment to unknown.
75 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
76 -- Given two entities for record components or discriminants, checks
77 -- if they have overlapping component clauses and issues errors if so.
79 function Get_Alignment_Value (Expr : Node_Id) return Uint;
80 -- Given the expression for an alignment value, returns the corresponding
81 -- Uint value. If the value is inappropriate, then error messages are
82 -- posted as required, and a value of No_Uint is returned.
84 function Is_Operational_Item (N : Node_Id) return Boolean;
85 -- A specification for a stream attribute is allowed before the full
86 -- type is declared, as explained in AI-00137 and the corrigendum.
87 -- Attributes that do not specify a representation characteristic are
88 -- operational attributes.
90 function Address_Aliased_Entity (N : Node_Id) return Entity_Id;
91 -- If expression N is of the form E'Address, return E
93 procedure New_Stream_Subprogram
98 -- Create a subprogram renaming of a given stream attribute to the
99 -- designated subprogram and then in the tagged case, provide this as a
100 -- primitive operation, or in the non-tagged case make an appropriate TSS
101 -- entry. This is more properly an expansion activity than just semantics,
102 -- but the presence of user-defined stream functions for limited types is a
103 -- legality check, which is why this takes place here rather than in
104 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
105 -- function to be generated.
107 -- To avoid elaboration anomalies with freeze nodes, for untagged types
108 -- we generate both a subprogram declaration and a subprogram renaming
109 -- declaration, so that the attribute specification is handled as a
110 -- renaming_as_body. For tagged types, the specification is one of the
113 ----------------------------------------------
114 -- Table for Validate_Unchecked_Conversions --
115 ----------------------------------------------
117 -- The following table collects unchecked conversions for validation.
118 -- Entries are made by Validate_Unchecked_Conversion and then the
119 -- call to Validate_Unchecked_Conversions does the actual error
120 -- checking and posting of warnings. The reason for this delayed
121 -- processing is to take advantage of back-annotations of size and
122 -- alignment values performed by the back end.
124 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
125 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
126 -- will already have modified all Sloc values if the -gnatD option is set.
128 type UC_Entry is record
129 Eloc : Source_Ptr; -- node used for posting warnings
130 Source : Entity_Id; -- source type for unchecked conversion
131 Target : Entity_Id; -- target type for unchecked conversion
134 package Unchecked_Conversions is new Table.Table (
135 Table_Component_Type => UC_Entry,
136 Table_Index_Type => Int,
137 Table_Low_Bound => 1,
139 Table_Increment => 200,
140 Table_Name => "Unchecked_Conversions");
142 ----------------------------------------
143 -- Table for Validate_Address_Clauses --
144 ----------------------------------------
146 -- If an address clause has the form
148 -- for X'Address use Expr
150 -- where Expr is of the form Y'Address or recursively is a reference
151 -- to a constant of either of these forms, and X and Y are entities of
152 -- objects, then if Y has a smaller alignment than X, that merits a
153 -- warning about possible bad alignment. The following table collects
154 -- address clauses of this kind. We put these in a table so that they
155 -- can be checked after the back end has completed annotation of the
156 -- alignments of objects, since we can catch more cases that way.
158 type Address_Clause_Check_Record is record
160 -- The address clause
163 -- The entity of the object overlaying Y
166 -- The entity of the object being overlaid
169 package Address_Clause_Checks is new Table.Table (
170 Table_Component_Type => Address_Clause_Check_Record,
171 Table_Index_Type => Int,
172 Table_Low_Bound => 1,
174 Table_Increment => 200,
175 Table_Name => "Address_Clause_Checks");
177 ----------------------------
178 -- Address_Aliased_Entity --
179 ----------------------------
181 function Address_Aliased_Entity (N : Node_Id) return Entity_Id is
183 if Nkind (N) = N_Attribute_Reference
184 and then Attribute_Name (N) = Name_Address
191 while Nkind_In (P, N_Selected_Component, N_Indexed_Component) loop
195 if Is_Entity_Name (P) then
202 end Address_Aliased_Entity;
204 -----------------------------------------
205 -- Adjust_Record_For_Reverse_Bit_Order --
206 -----------------------------------------
208 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
209 Max_Machine_Scalar_Size : constant Uint :=
211 (Standard_Long_Long_Integer_Size);
212 -- We use this as the maximum machine scalar size in the sense of AI-133
216 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
219 -- This first loop through components does two things. First it deals
220 -- with the case of components with component clauses whose length is
221 -- greater than the maximum machine scalar size (either accepting them
222 -- or rejecting as needed). Second, it counts the number of components
223 -- with component clauses whose length does not exceed this maximum for
227 Comp := First_Component_Or_Discriminant (R);
228 while Present (Comp) loop
230 CC : constant Node_Id := Component_Clause (Comp);
235 Fbit : constant Uint := Static_Integer (First_Bit (CC));
238 -- Case of component with size > max machine scalar
240 if Esize (Comp) > Max_Machine_Scalar_Size then
242 -- Must begin on byte boundary
244 if Fbit mod SSU /= 0 then
246 ("illegal first bit value for reverse bit order",
248 Error_Msg_Uint_1 := SSU;
249 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
252 ("\must be a multiple of ^ if size greater than ^",
255 -- Must end on byte boundary
257 elsif Esize (Comp) mod SSU /= 0 then
259 ("illegal last bit value for reverse bit order",
261 Error_Msg_Uint_1 := SSU;
262 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
265 ("\must be a multiple of ^ if size greater than ^",
268 -- OK, give warning if enabled
270 elsif Warn_On_Reverse_Bit_Order then
272 ("multi-byte field specified with non-standard"
273 & " Bit_Order?", CC);
275 if Bytes_Big_Endian then
277 ("\bytes are not reversed "
278 & "(component is big-endian)?", CC);
281 ("\bytes are not reversed "
282 & "(component is little-endian)?", CC);
286 -- Case where size is not greater than max machine
287 -- scalar. For now, we just count these.
290 Num_CC := Num_CC + 1;
296 Next_Component_Or_Discriminant (Comp);
299 -- We need to sort the component clauses on the basis of the Position
300 -- values in the clause, so we can group clauses with the same Position.
301 -- together to determine the relevant machine scalar size.
304 Comps : array (0 .. Num_CC) of Entity_Id;
305 -- Array to collect component and discriminant entities. The data
306 -- starts at index 1, the 0'th entry is for the sort routine.
308 function CP_Lt (Op1, Op2 : Natural) return Boolean;
309 -- Compare routine for Sort
311 procedure CP_Move (From : Natural; To : Natural);
312 -- Move routine for Sort
314 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
318 -- Start and stop positions in component list of set of components
319 -- with the same starting position (that constitute components in
320 -- a single machine scalar).
323 -- Maximum last bit value of any component in this set
326 -- Corresponding machine scalar size
332 function CP_Lt (Op1, Op2 : Natural) return Boolean is
334 return Position (Component_Clause (Comps (Op1))) <
335 Position (Component_Clause (Comps (Op2)));
342 procedure CP_Move (From : Natural; To : Natural) is
344 Comps (To) := Comps (From);
348 -- Collect the component clauses
351 Comp := First_Component_Or_Discriminant (R);
352 while Present (Comp) loop
353 if Present (Component_Clause (Comp))
354 and then Esize (Comp) <= Max_Machine_Scalar_Size
356 Num_CC := Num_CC + 1;
357 Comps (Num_CC) := Comp;
360 Next_Component_Or_Discriminant (Comp);
363 -- Sort by ascending position number
365 Sorting.Sort (Num_CC);
367 -- We now have all the components whose size does not exceed the max
368 -- machine scalar value, sorted by starting position. In this loop
369 -- we gather groups of clauses starting at the same position, to
370 -- process them in accordance with Ada 2005 AI-133.
373 while Stop < Num_CC loop
377 Static_Integer (Last_Bit (Component_Clause (Comps (Start))));
378 while Stop < Num_CC loop
380 (Position (Component_Clause (Comps (Stop + 1)))) =
382 (Position (Component_Clause (Comps (Stop))))
389 (Last_Bit (Component_Clause (Comps (Stop)))));
395 -- Now we have a group of component clauses from Start to Stop
396 -- whose positions are identical, and MaxL is the maximum last bit
397 -- value of any of these components.
399 -- We need to determine the corresponding machine scalar size.
400 -- This loop assumes that machine scalar sizes are even, and that
401 -- each possible machine scalar has twice as many bits as the
404 MSS := Max_Machine_Scalar_Size;
406 and then (MSS / 2) >= SSU
407 and then (MSS / 2) > MaxL
412 -- Here is where we fix up the Component_Bit_Offset value to
413 -- account for the reverse bit order. Some examples of what needs
414 -- to be done for the case of a machine scalar size of 8 are:
416 -- First_Bit .. Last_Bit Component_Bit_Offset
428 -- The general rule is that the first bit is obtained by
429 -- subtracting the old ending bit from machine scalar size - 1.
431 for C in Start .. Stop loop
433 Comp : constant Entity_Id := Comps (C);
434 CC : constant Node_Id := Component_Clause (Comp);
435 LB : constant Uint := Static_Integer (Last_Bit (CC));
436 NFB : constant Uint := MSS - Uint_1 - LB;
437 NLB : constant Uint := NFB + Esize (Comp) - 1;
438 Pos : constant Uint := Static_Integer (Position (CC));
441 if Warn_On_Reverse_Bit_Order then
442 Error_Msg_Uint_1 := MSS;
444 ("info: reverse bit order in machine " &
445 "scalar of length^?", First_Bit (CC));
446 Error_Msg_Uint_1 := NFB;
447 Error_Msg_Uint_2 := NLB;
449 if Bytes_Big_Endian then
451 ("?\info: big-endian range for "
452 & "component & is ^ .. ^",
453 First_Bit (CC), Comp);
456 ("?\info: little-endian range "
457 & "for component & is ^ .. ^",
458 First_Bit (CC), Comp);
462 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
463 Set_Normalized_First_Bit (Comp, NFB mod SSU);
468 end Adjust_Record_For_Reverse_Bit_Order;
470 --------------------------------------
471 -- Alignment_Check_For_Esize_Change --
472 --------------------------------------
474 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
476 -- If the alignment is known, and not set by a rep clause, and is
477 -- inconsistent with the size being set, then reset it to unknown,
478 -- we assume in this case that the size overrides the inherited
479 -- alignment, and that the alignment must be recomputed.
481 if Known_Alignment (Typ)
482 and then not Has_Alignment_Clause (Typ)
483 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
485 Init_Alignment (Typ);
487 end Alignment_Check_For_Esize_Change;
489 -----------------------
490 -- Analyze_At_Clause --
491 -----------------------
493 -- An at clause is replaced by the corresponding Address attribute
494 -- definition clause that is the preferred approach in Ada 95.
496 procedure Analyze_At_Clause (N : Node_Id) is
497 CS : constant Boolean := Comes_From_Source (N);
500 -- This is an obsolescent feature
502 Check_Restriction (No_Obsolescent_Features, N);
504 if Warn_On_Obsolescent_Feature then
506 ("at clause is an obsolescent feature (RM J.7(2))?", N);
508 ("\use address attribute definition clause instead?", N);
511 -- Rewrite as address clause
514 Make_Attribute_Definition_Clause (Sloc (N),
515 Name => Identifier (N),
516 Chars => Name_Address,
517 Expression => Expression (N)));
519 -- We preserve Comes_From_Source, since logically the clause still
520 -- comes from the source program even though it is changed in form.
522 Set_Comes_From_Source (N, CS);
524 -- Analyze rewritten clause
526 Analyze_Attribute_Definition_Clause (N);
527 end Analyze_At_Clause;
529 -----------------------------------------
530 -- Analyze_Attribute_Definition_Clause --
531 -----------------------------------------
533 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
534 Loc : constant Source_Ptr := Sloc (N);
535 Nam : constant Node_Id := Name (N);
536 Attr : constant Name_Id := Chars (N);
537 Expr : constant Node_Id := Expression (N);
538 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
542 FOnly : Boolean := False;
543 -- Reset to True for subtype specific attribute (Alignment, Size)
544 -- and for stream attributes, i.e. those cases where in the call
545 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
546 -- rules are checked. Note that the case of stream attributes is not
547 -- clear from the RM, but see AI95-00137. Also, the RM seems to
548 -- disallow Storage_Size for derived task types, but that is also
549 -- clearly unintentional.
551 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
552 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
553 -- definition clauses.
555 -----------------------------------
556 -- Analyze_Stream_TSS_Definition --
557 -----------------------------------
559 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
560 Subp : Entity_Id := Empty;
565 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
567 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
568 -- Return true if the entity is a subprogram with an appropriate
569 -- profile for the attribute being defined.
571 ----------------------
572 -- Has_Good_Profile --
573 ----------------------
575 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
577 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
578 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
579 (False => E_Procedure, True => E_Function);
583 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
587 F := First_Formal (Subp);
590 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
591 or else Designated_Type (Etype (F)) /=
592 Class_Wide_Type (RTE (RE_Root_Stream_Type))
597 if not Is_Function then
601 Expected_Mode : constant array (Boolean) of Entity_Kind :=
602 (False => E_In_Parameter,
603 True => E_Out_Parameter);
605 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
616 return Base_Type (Typ) = Base_Type (Ent)
617 and then No (Next_Formal (F));
618 end Has_Good_Profile;
620 -- Start of processing for Analyze_Stream_TSS_Definition
625 if not Is_Type (U_Ent) then
626 Error_Msg_N ("local name must be a subtype", Nam);
630 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
632 -- If Pnam is present, it can be either inherited from an ancestor
633 -- type (in which case it is legal to redefine it for this type), or
634 -- be a previous definition of the attribute for the same type (in
635 -- which case it is illegal).
637 -- In the first case, it will have been analyzed already, and we
638 -- can check that its profile does not match the expected profile
639 -- for a stream attribute of U_Ent. In the second case, either Pnam
640 -- has been analyzed (and has the expected profile), or it has not
641 -- been analyzed yet (case of a type that has not been frozen yet
642 -- and for which the stream attribute has been set using Set_TSS).
645 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
647 Error_Msg_Sloc := Sloc (Pnam);
648 Error_Msg_Name_1 := Attr;
649 Error_Msg_N ("% attribute already defined #", Nam);
655 if Is_Entity_Name (Expr) then
656 if not Is_Overloaded (Expr) then
657 if Has_Good_Profile (Entity (Expr)) then
658 Subp := Entity (Expr);
662 Get_First_Interp (Expr, I, It);
663 while Present (It.Nam) loop
664 if Has_Good_Profile (It.Nam) then
669 Get_Next_Interp (I, It);
674 if Present (Subp) then
675 if Is_Abstract_Subprogram (Subp) then
676 Error_Msg_N ("stream subprogram must not be abstract", Expr);
680 Set_Entity (Expr, Subp);
681 Set_Etype (Expr, Etype (Subp));
683 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
686 Error_Msg_Name_1 := Attr;
687 Error_Msg_N ("incorrect expression for% attribute", Expr);
689 end Analyze_Stream_TSS_Definition;
691 -- Start of processing for Analyze_Attribute_Definition_Clause
694 -- Process Ignore_Rep_Clauses option
696 if Ignore_Rep_Clauses then
699 -- The following should be ignored. They do not affect legality
700 -- and may be target dependent. The basic idea of -gnatI is to
701 -- ignore any rep clauses that may be target dependent but do not
702 -- affect legality (except possibly to be rejected because they
703 -- are incompatible with the compilation target).
705 when Attribute_Address |
706 Attribute_Alignment |
707 Attribute_Bit_Order |
708 Attribute_Component_Size |
709 Attribute_Machine_Radix |
710 Attribute_Object_Size |
713 Attribute_Stream_Size |
714 Attribute_Value_Size =>
716 Rewrite (N, Make_Null_Statement (Sloc (N)));
719 -- The following should not be ignored, because in the first place
720 -- they are reasonably portable, and should not cause problems in
721 -- compiling code from another target, and also they do affect
722 -- legality, e.g. failing to provide a stream attribute for a
723 -- type may make a program illegal.
725 when Attribute_External_Tag |
729 Attribute_Storage_Pool |
730 Attribute_Storage_Size |
734 -- Other cases are errors, which will be caught below
744 if Rep_Item_Too_Early (Ent, N) then
748 -- Rep clause applies to full view of incomplete type or private type if
749 -- we have one (if not, this is a premature use of the type). However,
750 -- certain semantic checks need to be done on the specified entity (i.e.
751 -- the private view), so we save it in Ent.
753 if Is_Private_Type (Ent)
754 and then Is_Derived_Type (Ent)
755 and then not Is_Tagged_Type (Ent)
756 and then No (Full_View (Ent))
758 -- If this is a private type whose completion is a derivation from
759 -- another private type, there is no full view, and the attribute
760 -- belongs to the type itself, not its underlying parent.
764 elsif Ekind (Ent) = E_Incomplete_Type then
766 -- The attribute applies to the full view, set the entity of the
767 -- attribute definition accordingly.
769 Ent := Underlying_Type (Ent);
771 Set_Entity (Nam, Ent);
774 U_Ent := Underlying_Type (Ent);
777 -- Complete other routine error checks
779 if Etype (Nam) = Any_Type then
782 elsif Scope (Ent) /= Current_Scope then
783 Error_Msg_N ("entity must be declared in this scope", Nam);
786 elsif No (U_Ent) then
789 elsif Is_Type (U_Ent)
790 and then not Is_First_Subtype (U_Ent)
791 and then Id /= Attribute_Object_Size
792 and then Id /= Attribute_Value_Size
793 and then not From_At_Mod (N)
795 Error_Msg_N ("cannot specify attribute for subtype", Nam);
799 -- Switch on particular attribute
807 -- Address attribute definition clause
809 when Attribute_Address => Address : begin
811 -- A little error check, catch for X'Address use X'Address;
813 if Nkind (Nam) = N_Identifier
814 and then Nkind (Expr) = N_Attribute_Reference
815 and then Attribute_Name (Expr) = Name_Address
816 and then Nkind (Prefix (Expr)) = N_Identifier
817 and then Chars (Nam) = Chars (Prefix (Expr))
820 ("address for & is self-referencing", Prefix (Expr), Ent);
824 -- Not that special case, carry on with analysis of expression
826 Analyze_And_Resolve (Expr, RTE (RE_Address));
828 if Present (Address_Clause (U_Ent)) then
829 Error_Msg_N ("address already given for &", Nam);
831 -- Case of address clause for subprogram
833 elsif Is_Subprogram (U_Ent) then
834 if Has_Homonym (U_Ent) then
836 ("address clause cannot be given " &
837 "for overloaded subprogram",
842 -- For subprograms, all address clauses are permitted, and we
843 -- mark the subprogram as having a deferred freeze so that Gigi
844 -- will not elaborate it too soon.
846 -- Above needs more comments, what is too soon about???
848 Set_Has_Delayed_Freeze (U_Ent);
850 -- Case of address clause for entry
852 elsif Ekind (U_Ent) = E_Entry then
853 if Nkind (Parent (N)) = N_Task_Body then
855 ("entry address must be specified in task spec", Nam);
859 -- For entries, we require a constant address
861 Check_Constant_Address_Clause (Expr, U_Ent);
863 -- Special checks for task types
865 if Is_Task_Type (Scope (U_Ent))
866 and then Comes_From_Source (Scope (U_Ent))
869 ("?entry address declared for entry in task type", N);
871 ("\?only one task can be declared of this type", N);
874 -- Entry address clauses are obsolescent
876 Check_Restriction (No_Obsolescent_Features, N);
878 if Warn_On_Obsolescent_Feature then
880 ("attaching interrupt to task entry is an " &
881 "obsolescent feature (RM J.7.1)?", N);
883 ("\use interrupt procedure instead?", N);
886 -- Case of an address clause for a controlled object which we
887 -- consider to be erroneous.
889 elsif Is_Controlled (Etype (U_Ent))
890 or else Has_Controlled_Component (Etype (U_Ent))
893 ("?controlled object& must not be overlaid", Nam, U_Ent);
895 ("\?Program_Error will be raised at run time", Nam);
896 Insert_Action (Declaration_Node (U_Ent),
897 Make_Raise_Program_Error (Loc,
898 Reason => PE_Overlaid_Controlled_Object));
901 -- Case of address clause for a (non-controlled) object
904 Ekind (U_Ent) = E_Variable
906 Ekind (U_Ent) = E_Constant
909 Expr : constant Node_Id := Expression (N);
910 Aent : constant Entity_Id := Address_Aliased_Entity (Expr);
911 Ent_Y : constant Entity_Id := Find_Overlaid_Object (N);
914 -- Exported variables cannot have an address clause,
915 -- because this cancels the effect of the pragma Export
917 if Is_Exported (U_Ent) then
919 ("cannot export object with address clause", Nam);
922 -- Overlaying controlled objects is erroneous
925 and then (Has_Controlled_Component (Etype (Aent))
926 or else Is_Controlled (Etype (Aent)))
929 ("?cannot overlay with controlled object", Expr);
931 ("\?Program_Error will be raised at run time", Expr);
932 Insert_Action (Declaration_Node (U_Ent),
933 Make_Raise_Program_Error (Loc,
934 Reason => PE_Overlaid_Controlled_Object));
938 and then Ekind (U_Ent) = E_Constant
939 and then not Is_Constant_Object (Aent)
941 Error_Msg_N ("constant overlays a variable?", Expr);
943 elsif Present (Renamed_Object (U_Ent)) then
945 ("address clause not allowed"
946 & " for a renaming declaration (RM 13.1(6))", Nam);
949 -- Imported variables can have an address clause, but then
950 -- the import is pretty meaningless except to suppress
951 -- initializations, so we do not need such variables to
952 -- be statically allocated (and in fact it causes trouble
953 -- if the address clause is a local value).
955 elsif Is_Imported (U_Ent) then
956 Set_Is_Statically_Allocated (U_Ent, False);
959 -- We mark a possible modification of a variable with an
960 -- address clause, since it is likely aliasing is occurring.
962 Note_Possible_Modification (Nam, Sure => False);
964 -- Here we are checking for explicit overlap of one variable
965 -- by another, and if we find this then mark the overlapped
966 -- variable as also being volatile to prevent unwanted
969 if Present (Ent_Y) then
970 Set_Treat_As_Volatile (Ent_Y);
973 -- Legality checks on the address clause for initialized
974 -- objects is deferred until the freeze point, because
975 -- a subsequent pragma might indicate that the object is
976 -- imported and thus not initialized.
978 Set_Has_Delayed_Freeze (U_Ent);
980 -- If an initialization call has been generated for this
981 -- object, it needs to be deferred to after the freeze node
982 -- we have just now added, otherwise GIGI will see a
983 -- reference to the variable (as actual to the IP call)
984 -- before its definition.
987 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
989 if Present (Init_Call) then
991 Append_Freeze_Action (U_Ent, Init_Call);
995 if Is_Exported (U_Ent) then
997 ("& cannot be exported if an address clause is given",
1000 ("\define and export a variable " &
1001 "that holds its address instead",
1005 -- Entity has delayed freeze, so we will generate an
1006 -- alignment check at the freeze point unless suppressed.
1008 if not Range_Checks_Suppressed (U_Ent)
1009 and then not Alignment_Checks_Suppressed (U_Ent)
1011 Set_Check_Address_Alignment (N);
1014 -- Kill the size check code, since we are not allocating
1015 -- the variable, it is somewhere else.
1017 Kill_Size_Check_Code (U_Ent);
1020 -- If the address clause is of the form:
1022 -- for Y'Address use X'Address
1026 -- Const : constant Address := X'Address;
1028 -- for Y'Address use Const;
1030 -- then we make an entry in the table for checking the size and
1031 -- alignment of the overlaying variable. We defer this check
1032 -- till after code generation to take full advantage of the
1033 -- annotation done by the back end. This entry is only made if
1034 -- we have not already posted a warning about size/alignment
1035 -- (some warnings of this type are posted in Checks), and if
1036 -- the address clause comes from source.
1038 if Address_Clause_Overlay_Warnings
1039 and then Comes_From_Source (N)
1042 Ent_X : Entity_Id := Empty;
1043 Ent_Y : Entity_Id := Empty;
1046 Ent_Y := Find_Overlaid_Object (N);
1048 if Present (Ent_Y) and then Is_Entity_Name (Name (N)) then
1049 Ent_X := Entity (Name (N));
1050 Address_Clause_Checks.Append ((N, Ent_X, Ent_Y));
1052 -- If variable overlays a constant view, and we are
1053 -- warning on overlays, then mark the variable as
1054 -- overlaying a constant (we will give warnings later
1055 -- if this variable is assigned).
1057 if Is_Constant_Object (Ent_Y)
1058 and then Ekind (Ent_X) = E_Variable
1060 Set_Overlays_Constant (Ent_X);
1066 -- Not a valid entity for an address clause
1069 Error_Msg_N ("address cannot be given for &", Nam);
1077 -- Alignment attribute definition clause
1079 when Attribute_Alignment => Alignment_Block : declare
1080 Align : constant Uint := Get_Alignment_Value (Expr);
1085 if not Is_Type (U_Ent)
1086 and then Ekind (U_Ent) /= E_Variable
1087 and then Ekind (U_Ent) /= E_Constant
1089 Error_Msg_N ("alignment cannot be given for &", Nam);
1091 elsif Has_Alignment_Clause (U_Ent) then
1092 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1093 Error_Msg_N ("alignment clause previously given#", N);
1095 elsif Align /= No_Uint then
1096 Set_Has_Alignment_Clause (U_Ent);
1097 Set_Alignment (U_Ent, Align);
1099 end Alignment_Block;
1105 -- Bit_Order attribute definition clause
1107 when Attribute_Bit_Order => Bit_Order : declare
1109 if not Is_Record_Type (U_Ent) then
1111 ("Bit_Order can only be defined for record type", Nam);
1114 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1116 if Etype (Expr) = Any_Type then
1119 elsif not Is_Static_Expression (Expr) then
1120 Flag_Non_Static_Expr
1121 ("Bit_Order requires static expression!", Expr);
1124 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1125 Set_Reverse_Bit_Order (U_Ent, True);
1131 --------------------
1132 -- Component_Size --
1133 --------------------
1135 -- Component_Size attribute definition clause
1137 when Attribute_Component_Size => Component_Size_Case : declare
1138 Csize : constant Uint := Static_Integer (Expr);
1141 New_Ctyp : Entity_Id;
1145 if not Is_Array_Type (U_Ent) then
1146 Error_Msg_N ("component size requires array type", Nam);
1150 Btype := Base_Type (U_Ent);
1152 if Has_Component_Size_Clause (Btype) then
1154 ("component size clause for& previously given", Nam);
1156 elsif Csize /= No_Uint then
1157 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
1159 if Has_Aliased_Components (Btype)
1162 and then Csize /= 16
1165 ("component size incorrect for aliased components", N);
1169 -- For the biased case, build a declaration for a subtype
1170 -- that will be used to represent the biased subtype that
1171 -- reflects the biased representation of components. We need
1172 -- this subtype to get proper conversions on referencing
1173 -- elements of the array. Note that component size clauses
1174 -- are ignored in VM mode.
1176 if VM_Target = No_VM then
1179 Make_Defining_Identifier (Loc,
1181 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1184 Make_Subtype_Declaration (Loc,
1185 Defining_Identifier => New_Ctyp,
1186 Subtype_Indication =>
1187 New_Occurrence_Of (Component_Type (Btype), Loc));
1189 Set_Parent (Decl, N);
1190 Analyze (Decl, Suppress => All_Checks);
1192 Set_Has_Delayed_Freeze (New_Ctyp, False);
1193 Set_Esize (New_Ctyp, Csize);
1194 Set_RM_Size (New_Ctyp, Csize);
1195 Init_Alignment (New_Ctyp);
1196 Set_Has_Biased_Representation (New_Ctyp, True);
1197 Set_Is_Itype (New_Ctyp, True);
1198 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1200 Set_Component_Type (Btype, New_Ctyp);
1202 if Warn_On_Biased_Representation then
1204 ("?component size clause forces biased "
1205 & "representation", N);
1209 Set_Component_Size (Btype, Csize);
1211 -- For VM case, we ignore component size clauses
1214 -- Give a warning unless we are in GNAT mode, in which case
1215 -- the warning is suppressed since it is not useful.
1217 if not GNAT_Mode then
1219 ("?component size ignored in this configuration", N);
1223 Set_Has_Component_Size_Clause (Btype, True);
1224 Set_Has_Non_Standard_Rep (Btype, True);
1226 end Component_Size_Case;
1232 when Attribute_External_Tag => External_Tag :
1234 if not Is_Tagged_Type (U_Ent) then
1235 Error_Msg_N ("should be a tagged type", Nam);
1238 Analyze_And_Resolve (Expr, Standard_String);
1240 if not Is_Static_Expression (Expr) then
1241 Flag_Non_Static_Expr
1242 ("static string required for tag name!", Nam);
1245 if VM_Target = No_VM then
1246 Set_Has_External_Tag_Rep_Clause (U_Ent);
1247 elsif not Inspector_Mode then
1248 Error_Msg_Name_1 := Attr;
1250 ("% attribute unsupported in this configuration", Nam);
1253 if not Is_Library_Level_Entity (U_Ent) then
1255 ("?non-unique external tag supplied for &", N, U_Ent);
1257 ("?\same external tag applies to all subprogram calls", N);
1259 ("?\corresponding internal tag cannot be obtained", N);
1267 when Attribute_Input =>
1268 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1269 Set_Has_Specified_Stream_Input (Ent);
1275 -- Machine radix attribute definition clause
1277 when Attribute_Machine_Radix => Machine_Radix : declare
1278 Radix : constant Uint := Static_Integer (Expr);
1281 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1282 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1284 elsif Has_Machine_Radix_Clause (U_Ent) then
1285 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1286 Error_Msg_N ("machine radix clause previously given#", N);
1288 elsif Radix /= No_Uint then
1289 Set_Has_Machine_Radix_Clause (U_Ent);
1290 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1294 elsif Radix = 10 then
1295 Set_Machine_Radix_10 (U_Ent);
1297 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1306 -- Object_Size attribute definition clause
1308 when Attribute_Object_Size => Object_Size : declare
1309 Size : constant Uint := Static_Integer (Expr);
1312 pragma Warnings (Off, Biased);
1315 if not Is_Type (U_Ent) then
1316 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1318 elsif Has_Object_Size_Clause (U_Ent) then
1319 Error_Msg_N ("Object_Size already given for &", Nam);
1322 Check_Size (Expr, U_Ent, Size, Biased);
1330 UI_Mod (Size, 64) /= 0
1333 ("Object_Size must be 8, 16, 32, or multiple of 64",
1337 Set_Esize (U_Ent, Size);
1338 Set_Has_Object_Size_Clause (U_Ent);
1339 Alignment_Check_For_Esize_Change (U_Ent);
1347 when Attribute_Output =>
1348 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1349 Set_Has_Specified_Stream_Output (Ent);
1355 when Attribute_Read =>
1356 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1357 Set_Has_Specified_Stream_Read (Ent);
1363 -- Size attribute definition clause
1365 when Attribute_Size => Size : declare
1366 Size : constant Uint := Static_Integer (Expr);
1373 if Has_Size_Clause (U_Ent) then
1374 Error_Msg_N ("size already given for &", Nam);
1376 elsif not Is_Type (U_Ent)
1377 and then Ekind (U_Ent) /= E_Variable
1378 and then Ekind (U_Ent) /= E_Constant
1380 Error_Msg_N ("size cannot be given for &", Nam);
1382 elsif Is_Array_Type (U_Ent)
1383 and then not Is_Constrained (U_Ent)
1386 ("size cannot be given for unconstrained array", Nam);
1388 elsif Size /= No_Uint then
1389 if Is_Type (U_Ent) then
1392 Etyp := Etype (U_Ent);
1395 -- Check size, note that Gigi is in charge of checking that the
1396 -- size of an array or record type is OK. Also we do not check
1397 -- the size in the ordinary fixed-point case, since it is too
1398 -- early to do so (there may be subsequent small clause that
1399 -- affects the size). We can check the size if a small clause
1400 -- has already been given.
1402 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1403 or else Has_Small_Clause (U_Ent)
1405 Check_Size (Expr, Etyp, Size, Biased);
1406 Set_Has_Biased_Representation (U_Ent, Biased);
1408 if Biased and Warn_On_Biased_Representation then
1410 ("?size clause forces biased representation", N);
1414 -- For types set RM_Size and Esize if possible
1416 if Is_Type (U_Ent) then
1417 Set_RM_Size (U_Ent, Size);
1419 -- For scalar types, increase Object_Size to power of 2, but
1420 -- not less than a storage unit in any case (i.e., normally
1421 -- this means it will be byte addressable).
1423 if Is_Scalar_Type (U_Ent) then
1424 if Size <= System_Storage_Unit then
1425 Init_Esize (U_Ent, System_Storage_Unit);
1426 elsif Size <= 16 then
1427 Init_Esize (U_Ent, 16);
1428 elsif Size <= 32 then
1429 Init_Esize (U_Ent, 32);
1431 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1434 -- For all other types, object size = value size. The
1435 -- backend will adjust as needed.
1438 Set_Esize (U_Ent, Size);
1441 Alignment_Check_For_Esize_Change (U_Ent);
1443 -- For objects, set Esize only
1446 if Is_Elementary_Type (Etyp) then
1447 if Size /= System_Storage_Unit
1449 Size /= System_Storage_Unit * 2
1451 Size /= System_Storage_Unit * 4
1453 Size /= System_Storage_Unit * 8
1455 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1456 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1458 ("size for primitive object must be a power of 2"
1459 & " in the range ^-^", N);
1463 Set_Esize (U_Ent, Size);
1466 Set_Has_Size_Clause (U_Ent);
1474 -- Small attribute definition clause
1476 when Attribute_Small => Small : declare
1477 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1481 Analyze_And_Resolve (Expr, Any_Real);
1483 if Etype (Expr) = Any_Type then
1486 elsif not Is_Static_Expression (Expr) then
1487 Flag_Non_Static_Expr
1488 ("small requires static expression!", Expr);
1492 Small := Expr_Value_R (Expr);
1494 if Small <= Ureal_0 then
1495 Error_Msg_N ("small value must be greater than zero", Expr);
1501 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1503 ("small requires an ordinary fixed point type", Nam);
1505 elsif Has_Small_Clause (U_Ent) then
1506 Error_Msg_N ("small already given for &", Nam);
1508 elsif Small > Delta_Value (U_Ent) then
1510 ("small value must not be greater then delta value", Nam);
1513 Set_Small_Value (U_Ent, Small);
1514 Set_Small_Value (Implicit_Base, Small);
1515 Set_Has_Small_Clause (U_Ent);
1516 Set_Has_Small_Clause (Implicit_Base);
1517 Set_Has_Non_Standard_Rep (Implicit_Base);
1525 -- Storage_Pool attribute definition clause
1527 when Attribute_Storage_Pool => Storage_Pool : declare
1532 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1534 ("storage pool cannot be given for access-to-subprogram type",
1538 elsif Ekind (U_Ent) /= E_Access_Type
1539 and then Ekind (U_Ent) /= E_General_Access_Type
1542 ("storage pool can only be given for access types", Nam);
1545 elsif Is_Derived_Type (U_Ent) then
1547 ("storage pool cannot be given for a derived access type",
1550 elsif Has_Storage_Size_Clause (U_Ent) then
1551 Error_Msg_N ("storage size already given for &", Nam);
1554 elsif Present (Associated_Storage_Pool (U_Ent)) then
1555 Error_Msg_N ("storage pool already given for &", Nam);
1560 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1562 if not Denotes_Variable (Expr) then
1563 Error_Msg_N ("storage pool must be a variable", Expr);
1567 if Nkind (Expr) = N_Type_Conversion then
1568 T := Etype (Expression (Expr));
1573 -- The Stack_Bounded_Pool is used internally for implementing
1574 -- access types with a Storage_Size. Since it only work
1575 -- properly when used on one specific type, we need to check
1576 -- that it is not hijacked improperly:
1577 -- type T is access Integer;
1578 -- for T'Storage_Size use n;
1579 -- type Q is access Float;
1580 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1582 if RTE_Available (RE_Stack_Bounded_Pool)
1583 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1585 Error_Msg_N ("non-shareable internal Pool", Expr);
1589 -- If the argument is a name that is not an entity name, then
1590 -- we construct a renaming operation to define an entity of
1591 -- type storage pool.
1593 if not Is_Entity_Name (Expr)
1594 and then Is_Object_Reference (Expr)
1597 Make_Defining_Identifier (Loc,
1598 Chars => New_Internal_Name ('P'));
1601 Rnode : constant Node_Id :=
1602 Make_Object_Renaming_Declaration (Loc,
1603 Defining_Identifier => Pool,
1605 New_Occurrence_Of (Etype (Expr), Loc),
1609 Insert_Before (N, Rnode);
1611 Set_Associated_Storage_Pool (U_Ent, Pool);
1614 elsif Is_Entity_Name (Expr) then
1615 Pool := Entity (Expr);
1617 -- If pool is a renamed object, get original one. This can
1618 -- happen with an explicit renaming, and within instances.
1620 while Present (Renamed_Object (Pool))
1621 and then Is_Entity_Name (Renamed_Object (Pool))
1623 Pool := Entity (Renamed_Object (Pool));
1626 if Present (Renamed_Object (Pool))
1627 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1628 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1630 Pool := Entity (Expression (Renamed_Object (Pool)));
1633 Set_Associated_Storage_Pool (U_Ent, Pool);
1635 elsif Nkind (Expr) = N_Type_Conversion
1636 and then Is_Entity_Name (Expression (Expr))
1637 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1639 Pool := Entity (Expression (Expr));
1640 Set_Associated_Storage_Pool (U_Ent, Pool);
1643 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1652 -- Storage_Size attribute definition clause
1654 when Attribute_Storage_Size => Storage_Size : declare
1655 Btype : constant Entity_Id := Base_Type (U_Ent);
1659 if Is_Task_Type (U_Ent) then
1660 Check_Restriction (No_Obsolescent_Features, N);
1662 if Warn_On_Obsolescent_Feature then
1664 ("storage size clause for task is an " &
1665 "obsolescent feature (RM J.9)?", N);
1667 ("\use Storage_Size pragma instead?", N);
1673 if not Is_Access_Type (U_Ent)
1674 and then Ekind (U_Ent) /= E_Task_Type
1676 Error_Msg_N ("storage size cannot be given for &", Nam);
1678 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1680 ("storage size cannot be given for a derived access type",
1683 elsif Has_Storage_Size_Clause (Btype) then
1684 Error_Msg_N ("storage size already given for &", Nam);
1687 Analyze_And_Resolve (Expr, Any_Integer);
1689 if Is_Access_Type (U_Ent) then
1690 if Present (Associated_Storage_Pool (U_Ent)) then
1691 Error_Msg_N ("storage pool already given for &", Nam);
1695 if Compile_Time_Known_Value (Expr)
1696 and then Expr_Value (Expr) = 0
1698 Set_No_Pool_Assigned (Btype);
1701 else -- Is_Task_Type (U_Ent)
1702 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1704 if Present (Sprag) then
1705 Error_Msg_Sloc := Sloc (Sprag);
1707 ("Storage_Size already specified#", Nam);
1712 Set_Has_Storage_Size_Clause (Btype);
1720 when Attribute_Stream_Size => Stream_Size : declare
1721 Size : constant Uint := Static_Integer (Expr);
1724 if Ada_Version <= Ada_95 then
1725 Check_Restriction (No_Implementation_Attributes, N);
1728 if Has_Stream_Size_Clause (U_Ent) then
1729 Error_Msg_N ("Stream_Size already given for &", Nam);
1731 elsif Is_Elementary_Type (U_Ent) then
1732 if Size /= System_Storage_Unit
1734 Size /= System_Storage_Unit * 2
1736 Size /= System_Storage_Unit * 4
1738 Size /= System_Storage_Unit * 8
1740 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1742 ("stream size for elementary type must be a"
1743 & " power of 2 and at least ^", N);
1745 elsif RM_Size (U_Ent) > Size then
1746 Error_Msg_Uint_1 := RM_Size (U_Ent);
1748 ("stream size for elementary type must be a"
1749 & " power of 2 and at least ^", N);
1752 Set_Has_Stream_Size_Clause (U_Ent);
1755 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1763 -- Value_Size attribute definition clause
1765 when Attribute_Value_Size => Value_Size : declare
1766 Size : constant Uint := Static_Integer (Expr);
1770 if not Is_Type (U_Ent) then
1771 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1774 (Get_Attribute_Definition_Clause
1775 (U_Ent, Attribute_Value_Size))
1777 Error_Msg_N ("Value_Size already given for &", Nam);
1779 elsif Is_Array_Type (U_Ent)
1780 and then not Is_Constrained (U_Ent)
1783 ("Value_Size cannot be given for unconstrained array", Nam);
1786 if Is_Elementary_Type (U_Ent) then
1787 Check_Size (Expr, U_Ent, Size, Biased);
1788 Set_Has_Biased_Representation (U_Ent, Biased);
1790 if Biased and Warn_On_Biased_Representation then
1792 ("?value size clause forces biased representation", N);
1796 Set_RM_Size (U_Ent, Size);
1804 when Attribute_Write =>
1805 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1806 Set_Has_Specified_Stream_Write (Ent);
1808 -- All other attributes cannot be set
1812 ("attribute& cannot be set with definition clause", N);
1815 -- The test for the type being frozen must be performed after
1816 -- any expression the clause has been analyzed since the expression
1817 -- itself might cause freezing that makes the clause illegal.
1819 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1822 end Analyze_Attribute_Definition_Clause;
1824 ----------------------------
1825 -- Analyze_Code_Statement --
1826 ----------------------------
1828 procedure Analyze_Code_Statement (N : Node_Id) is
1829 HSS : constant Node_Id := Parent (N);
1830 SBody : constant Node_Id := Parent (HSS);
1831 Subp : constant Entity_Id := Current_Scope;
1838 -- Analyze and check we get right type, note that this implements the
1839 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1840 -- is the only way that Asm_Insn could possibly be visible.
1842 Analyze_And_Resolve (Expression (N));
1844 if Etype (Expression (N)) = Any_Type then
1846 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1847 Error_Msg_N ("incorrect type for code statement", N);
1851 Check_Code_Statement (N);
1853 -- Make sure we appear in the handled statement sequence of a
1854 -- subprogram (RM 13.8(3)).
1856 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
1857 or else Nkind (SBody) /= N_Subprogram_Body
1860 ("code statement can only appear in body of subprogram", N);
1864 -- Do remaining checks (RM 13.8(3)) if not already done
1866 if not Is_Machine_Code_Subprogram (Subp) then
1867 Set_Is_Machine_Code_Subprogram (Subp);
1869 -- No exception handlers allowed
1871 if Present (Exception_Handlers (HSS)) then
1873 ("exception handlers not permitted in machine code subprogram",
1874 First (Exception_Handlers (HSS)));
1877 -- No declarations other than use clauses and pragmas (we allow
1878 -- certain internally generated declarations as well).
1880 Decl := First (Declarations (SBody));
1881 while Present (Decl) loop
1882 DeclO := Original_Node (Decl);
1883 if Comes_From_Source (DeclO)
1884 and not Nkind_In (DeclO, N_Pragma,
1885 N_Use_Package_Clause,
1887 N_Implicit_Label_Declaration)
1890 ("this declaration not allowed in machine code subprogram",
1897 -- No statements other than code statements, pragmas, and labels.
1898 -- Again we allow certain internally generated statements.
1900 Stmt := First (Statements (HSS));
1901 while Present (Stmt) loop
1902 StmtO := Original_Node (Stmt);
1903 if Comes_From_Source (StmtO)
1904 and then not Nkind_In (StmtO, N_Pragma,
1909 ("this statement is not allowed in machine code subprogram",
1916 end Analyze_Code_Statement;
1918 -----------------------------------------------
1919 -- Analyze_Enumeration_Representation_Clause --
1920 -----------------------------------------------
1922 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
1923 Ident : constant Node_Id := Identifier (N);
1924 Aggr : constant Node_Id := Array_Aggregate (N);
1925 Enumtype : Entity_Id;
1931 Err : Boolean := False;
1933 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
1934 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
1939 if Ignore_Rep_Clauses then
1943 -- First some basic error checks
1946 Enumtype := Entity (Ident);
1948 if Enumtype = Any_Type
1949 or else Rep_Item_Too_Early (Enumtype, N)
1953 Enumtype := Underlying_Type (Enumtype);
1956 if not Is_Enumeration_Type (Enumtype) then
1958 ("enumeration type required, found}",
1959 Ident, First_Subtype (Enumtype));
1963 -- Ignore rep clause on generic actual type. This will already have
1964 -- been flagged on the template as an error, and this is the safest
1965 -- way to ensure we don't get a junk cascaded message in the instance.
1967 if Is_Generic_Actual_Type (Enumtype) then
1970 -- Type must be in current scope
1972 elsif Scope (Enumtype) /= Current_Scope then
1973 Error_Msg_N ("type must be declared in this scope", Ident);
1976 -- Type must be a first subtype
1978 elsif not Is_First_Subtype (Enumtype) then
1979 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
1982 -- Ignore duplicate rep clause
1984 elsif Has_Enumeration_Rep_Clause (Enumtype) then
1985 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
1988 -- Don't allow rep clause for standard [wide_[wide_]]character
1990 elsif Is_Standard_Character_Type (Enumtype) then
1991 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
1994 -- Check that the expression is a proper aggregate (no parentheses)
1996 elsif Paren_Count (Aggr) /= 0 then
1998 ("extra parentheses surrounding aggregate not allowed",
2002 -- All tests passed, so set rep clause in place
2005 Set_Has_Enumeration_Rep_Clause (Enumtype);
2006 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2009 -- Now we process the aggregate. Note that we don't use the normal
2010 -- aggregate code for this purpose, because we don't want any of the
2011 -- normal expansion activities, and a number of special semantic
2012 -- rules apply (including the component type being any integer type)
2014 Elit := First_Literal (Enumtype);
2016 -- First the positional entries if any
2018 if Present (Expressions (Aggr)) then
2019 Expr := First (Expressions (Aggr));
2020 while Present (Expr) loop
2022 Error_Msg_N ("too many entries in aggregate", Expr);
2026 Val := Static_Integer (Expr);
2028 -- Err signals that we found some incorrect entries processing
2029 -- the list. The final checks for completeness and ordering are
2030 -- skipped in this case.
2032 if Val = No_Uint then
2034 elsif Val < Lo or else Hi < Val then
2035 Error_Msg_N ("value outside permitted range", Expr);
2039 Set_Enumeration_Rep (Elit, Val);
2040 Set_Enumeration_Rep_Expr (Elit, Expr);
2046 -- Now process the named entries if present
2048 if Present (Component_Associations (Aggr)) then
2049 Assoc := First (Component_Associations (Aggr));
2050 while Present (Assoc) loop
2051 Choice := First (Choices (Assoc));
2053 if Present (Next (Choice)) then
2055 ("multiple choice not allowed here", Next (Choice));
2059 if Nkind (Choice) = N_Others_Choice then
2060 Error_Msg_N ("others choice not allowed here", Choice);
2063 elsif Nkind (Choice) = N_Range then
2064 -- ??? should allow zero/one element range here
2065 Error_Msg_N ("range not allowed here", Choice);
2069 Analyze_And_Resolve (Choice, Enumtype);
2071 if Is_Entity_Name (Choice)
2072 and then Is_Type (Entity (Choice))
2074 Error_Msg_N ("subtype name not allowed here", Choice);
2076 -- ??? should allow static subtype with zero/one entry
2078 elsif Etype (Choice) = Base_Type (Enumtype) then
2079 if not Is_Static_Expression (Choice) then
2080 Flag_Non_Static_Expr
2081 ("non-static expression used for choice!", Choice);
2085 Elit := Expr_Value_E (Choice);
2087 if Present (Enumeration_Rep_Expr (Elit)) then
2088 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2090 ("representation for& previously given#",
2095 Set_Enumeration_Rep_Expr (Elit, Choice);
2097 Expr := Expression (Assoc);
2098 Val := Static_Integer (Expr);
2100 if Val = No_Uint then
2103 elsif Val < Lo or else Hi < Val then
2104 Error_Msg_N ("value outside permitted range", Expr);
2108 Set_Enumeration_Rep (Elit, Val);
2117 -- Aggregate is fully processed. Now we check that a full set of
2118 -- representations was given, and that they are in range and in order.
2119 -- These checks are only done if no other errors occurred.
2125 Elit := First_Literal (Enumtype);
2126 while Present (Elit) loop
2127 if No (Enumeration_Rep_Expr (Elit)) then
2128 Error_Msg_NE ("missing representation for&!", N, Elit);
2131 Val := Enumeration_Rep (Elit);
2133 if Min = No_Uint then
2137 if Val /= No_Uint then
2138 if Max /= No_Uint and then Val <= Max then
2140 ("enumeration value for& not ordered!",
2141 Enumeration_Rep_Expr (Elit), Elit);
2147 -- If there is at least one literal whose representation
2148 -- is not equal to the Pos value, then note that this
2149 -- enumeration type has a non-standard representation.
2151 if Val /= Enumeration_Pos (Elit) then
2152 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2159 -- Now set proper size information
2162 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2165 if Has_Size_Clause (Enumtype) then
2166 if Esize (Enumtype) >= Minsize then
2171 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2173 if Esize (Enumtype) < Minsize then
2174 Error_Msg_N ("previously given size is too small", N);
2177 Set_Has_Biased_Representation (Enumtype);
2182 Set_RM_Size (Enumtype, Minsize);
2183 Set_Enum_Esize (Enumtype);
2186 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2187 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2188 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2192 -- We repeat the too late test in case it froze itself!
2194 if Rep_Item_Too_Late (Enumtype, N) then
2197 end Analyze_Enumeration_Representation_Clause;
2199 ----------------------------
2200 -- Analyze_Free_Statement --
2201 ----------------------------
2203 procedure Analyze_Free_Statement (N : Node_Id) is
2205 Analyze (Expression (N));
2206 end Analyze_Free_Statement;
2208 ------------------------------------------
2209 -- Analyze_Record_Representation_Clause --
2210 ------------------------------------------
2212 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2213 Loc : constant Source_Ptr := Sloc (N);
2214 Ident : constant Node_Id := Identifier (N);
2215 Rectype : Entity_Id;
2221 Hbit : Uint := Uint_0;
2226 Max_Bit_So_Far : Uint;
2227 -- Records the maximum bit position so far. If all field positions
2228 -- are monotonically increasing, then we can skip the circuit for
2229 -- checking for overlap, since no overlap is possible.
2231 Overlap_Check_Required : Boolean;
2232 -- Used to keep track of whether or not an overlap check is required
2234 Ccount : Natural := 0;
2235 -- Number of component clauses in record rep clause
2237 CR_Pragma : Node_Id := Empty;
2238 -- Points to N_Pragma node if Complete_Representation pragma present
2241 if Ignore_Rep_Clauses then
2246 Rectype := Entity (Ident);
2248 if Rectype = Any_Type
2249 or else Rep_Item_Too_Early (Rectype, N)
2253 Rectype := Underlying_Type (Rectype);
2256 -- First some basic error checks
2258 if not Is_Record_Type (Rectype) then
2260 ("record type required, found}", Ident, First_Subtype (Rectype));
2263 elsif Is_Unchecked_Union (Rectype) then
2265 ("record rep clause not allowed for Unchecked_Union", N);
2267 elsif Scope (Rectype) /= Current_Scope then
2268 Error_Msg_N ("type must be declared in this scope", N);
2271 elsif not Is_First_Subtype (Rectype) then
2272 Error_Msg_N ("cannot give record rep clause for subtype", N);
2275 elsif Has_Record_Rep_Clause (Rectype) then
2276 Error_Msg_N ("duplicate record rep clause ignored", N);
2279 elsif Rep_Item_Too_Late (Rectype, N) then
2283 if Present (Mod_Clause (N)) then
2285 Loc : constant Source_Ptr := Sloc (N);
2286 M : constant Node_Id := Mod_Clause (N);
2287 P : constant List_Id := Pragmas_Before (M);
2291 pragma Warnings (Off, Mod_Val);
2294 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2296 if Warn_On_Obsolescent_Feature then
2298 ("mod clause is an obsolescent feature (RM J.8)?", N);
2300 ("\use alignment attribute definition clause instead?", N);
2307 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2308 -- the Mod clause into an alignment clause anyway, so that the
2309 -- back-end can compute and back-annotate properly the size and
2310 -- alignment of types that may include this record.
2312 -- This seems dubious, this destroys the source tree in a manner
2313 -- not detectable by ASIS ???
2315 if Operating_Mode = Check_Semantics
2319 Make_Attribute_Definition_Clause (Loc,
2320 Name => New_Reference_To (Base_Type (Rectype), Loc),
2321 Chars => Name_Alignment,
2322 Expression => Relocate_Node (Expression (M)));
2324 Set_From_At_Mod (AtM_Nod);
2325 Insert_After (N, AtM_Nod);
2326 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2327 Set_Mod_Clause (N, Empty);
2330 -- Get the alignment value to perform error checking
2332 Mod_Val := Get_Alignment_Value (Expression (M));
2338 -- For untagged types, clear any existing component clauses for the
2339 -- type. If the type is derived, this is what allows us to override
2340 -- a rep clause for the parent. For type extensions, the representation
2341 -- of the inherited components is inherited, so we want to keep previous
2342 -- component clauses for completeness.
2344 if not Is_Tagged_Type (Rectype) then
2345 Comp := First_Component_Or_Discriminant (Rectype);
2346 while Present (Comp) loop
2347 Set_Component_Clause (Comp, Empty);
2348 Next_Component_Or_Discriminant (Comp);
2352 -- All done if no component clauses
2354 CC := First (Component_Clauses (N));
2360 -- If a tag is present, then create a component clause that places it
2361 -- at the start of the record (otherwise gigi may place it after other
2362 -- fields that have rep clauses).
2364 Fent := First_Entity (Rectype);
2366 if Nkind (Fent) = N_Defining_Identifier
2367 and then Chars (Fent) = Name_uTag
2369 Set_Component_Bit_Offset (Fent, Uint_0);
2370 Set_Normalized_Position (Fent, Uint_0);
2371 Set_Normalized_First_Bit (Fent, Uint_0);
2372 Set_Normalized_Position_Max (Fent, Uint_0);
2373 Init_Esize (Fent, System_Address_Size);
2375 Set_Component_Clause (Fent,
2376 Make_Component_Clause (Loc,
2378 Make_Identifier (Loc,
2379 Chars => Name_uTag),
2382 Make_Integer_Literal (Loc,
2386 Make_Integer_Literal (Loc,
2390 Make_Integer_Literal (Loc,
2391 UI_From_Int (System_Address_Size))));
2393 Ccount := Ccount + 1;
2396 -- A representation like this applies to the base type
2398 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2399 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2400 Set_Has_Specified_Layout (Base_Type (Rectype));
2402 Max_Bit_So_Far := Uint_Minus_1;
2403 Overlap_Check_Required := False;
2405 -- Process the component clauses
2407 while Present (CC) loop
2411 if Nkind (CC) = N_Pragma then
2414 -- The only pragma of interest is Complete_Representation
2416 if Pragma_Name (CC) = Name_Complete_Representation then
2420 -- Processing for real component clause
2423 Ccount := Ccount + 1;
2424 Posit := Static_Integer (Position (CC));
2425 Fbit := Static_Integer (First_Bit (CC));
2426 Lbit := Static_Integer (Last_Bit (CC));
2429 and then Fbit /= No_Uint
2430 and then Lbit /= No_Uint
2434 ("position cannot be negative", Position (CC));
2438 ("first bit cannot be negative", First_Bit (CC));
2440 -- The Last_Bit specified in a component clause must not be
2441 -- less than the First_Bit minus one (RM-13.5.1(10)).
2443 elsif Lbit < Fbit - 1 then
2445 ("last bit cannot be less than first bit minus one",
2448 -- Values look OK, so find the corresponding record component
2449 -- Even though the syntax allows an attribute reference for
2450 -- implementation-defined components, GNAT does not allow the
2451 -- tag to get an explicit position.
2453 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2454 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2455 Error_Msg_N ("position of tag cannot be specified", CC);
2457 Error_Msg_N ("illegal component name", CC);
2461 Comp := First_Entity (Rectype);
2462 while Present (Comp) loop
2463 exit when Chars (Comp) = Chars (Component_Name (CC));
2469 -- Maybe component of base type that is absent from
2470 -- statically constrained first subtype.
2472 Comp := First_Entity (Base_Type (Rectype));
2473 while Present (Comp) loop
2474 exit when Chars (Comp) = Chars (Component_Name (CC));
2481 ("component clause is for non-existent field", CC);
2483 elsif Present (Component_Clause (Comp)) then
2485 -- Diagnose duplicate rep clause, or check consistency
2486 -- if this is an inherited component. In a double fault,
2487 -- there may be a duplicate inconsistent clause for an
2488 -- inherited component.
2490 if Scope (Original_Record_Component (Comp)) = Rectype
2491 or else Parent (Component_Clause (Comp)) = N
2493 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2494 Error_Msg_N ("component clause previously given#", CC);
2498 Rep1 : constant Node_Id := Component_Clause (Comp);
2500 if Intval (Position (Rep1)) /=
2501 Intval (Position (CC))
2502 or else Intval (First_Bit (Rep1)) /=
2503 Intval (First_Bit (CC))
2504 or else Intval (Last_Bit (Rep1)) /=
2505 Intval (Last_Bit (CC))
2507 Error_Msg_N ("component clause inconsistent "
2508 & "with representation of ancestor", CC);
2509 elsif Warn_On_Redundant_Constructs then
2510 Error_Msg_N ("?redundant component clause "
2511 & "for inherited component!", CC);
2517 -- Make reference for field in record rep clause and set
2518 -- appropriate entity field in the field identifier.
2521 (Comp, Component_Name (CC), Set_Ref => False);
2522 Set_Entity (Component_Name (CC), Comp);
2524 -- Update Fbit and Lbit to the actual bit number
2526 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2527 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2529 if Fbit <= Max_Bit_So_Far then
2530 Overlap_Check_Required := True;
2532 Max_Bit_So_Far := Lbit;
2535 if Has_Size_Clause (Rectype)
2536 and then Esize (Rectype) <= Lbit
2539 ("bit number out of range of specified size",
2542 Set_Component_Clause (Comp, CC);
2543 Set_Component_Bit_Offset (Comp, Fbit);
2544 Set_Esize (Comp, 1 + (Lbit - Fbit));
2545 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2546 Set_Normalized_Position (Comp, Fbit / SSU);
2548 Set_Normalized_Position_Max
2549 (Fent, Normalized_Position (Fent));
2551 if Is_Tagged_Type (Rectype)
2552 and then Fbit < System_Address_Size
2555 ("component overlaps tag field of&",
2559 -- This information is also set in the corresponding
2560 -- component of the base type, found by accessing the
2561 -- Original_Record_Component link if it is present.
2563 Ocomp := Original_Record_Component (Comp);
2570 (Component_Name (CC),
2575 Set_Has_Biased_Representation (Comp, Biased);
2577 if Biased and Warn_On_Biased_Representation then
2579 ("?component clause forces biased "
2580 & "representation", CC);
2583 if Present (Ocomp) then
2584 Set_Component_Clause (Ocomp, CC);
2585 Set_Component_Bit_Offset (Ocomp, Fbit);
2586 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2587 Set_Normalized_Position (Ocomp, Fbit / SSU);
2588 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2590 Set_Normalized_Position_Max
2591 (Ocomp, Normalized_Position (Ocomp));
2593 Set_Has_Biased_Representation
2594 (Ocomp, Has_Biased_Representation (Comp));
2597 if Esize (Comp) < 0 then
2598 Error_Msg_N ("component size is negative", CC);
2609 -- Now that we have processed all the component clauses, check for
2610 -- overlap. We have to leave this till last, since the components can
2611 -- appear in any arbitrary order in the representation clause.
2613 -- We do not need this check if all specified ranges were monotonic,
2614 -- as recorded by Overlap_Check_Required being False at this stage.
2616 -- This first section checks if there are any overlapping entries at
2617 -- all. It does this by sorting all entries and then seeing if there are
2618 -- any overlaps. If there are none, then that is decisive, but if there
2619 -- are overlaps, they may still be OK (they may result from fields in
2620 -- different variants).
2622 if Overlap_Check_Required then
2623 Overlap_Check1 : declare
2625 OC_Fbit : array (0 .. Ccount) of Uint;
2626 -- First-bit values for component clauses, the value is the offset
2627 -- of the first bit of the field from start of record. The zero
2628 -- entry is for use in sorting.
2630 OC_Lbit : array (0 .. Ccount) of Uint;
2631 -- Last-bit values for component clauses, the value is the offset
2632 -- of the last bit of the field from start of record. The zero
2633 -- entry is for use in sorting.
2635 OC_Count : Natural := 0;
2636 -- Count of entries in OC_Fbit and OC_Lbit
2638 function OC_Lt (Op1, Op2 : Natural) return Boolean;
2639 -- Compare routine for Sort
2641 procedure OC_Move (From : Natural; To : Natural);
2642 -- Move routine for Sort
2644 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
2646 function OC_Lt (Op1, Op2 : Natural) return Boolean is
2648 return OC_Fbit (Op1) < OC_Fbit (Op2);
2651 procedure OC_Move (From : Natural; To : Natural) is
2653 OC_Fbit (To) := OC_Fbit (From);
2654 OC_Lbit (To) := OC_Lbit (From);
2658 CC := First (Component_Clauses (N));
2659 while Present (CC) loop
2660 if Nkind (CC) /= N_Pragma then
2661 Posit := Static_Integer (Position (CC));
2662 Fbit := Static_Integer (First_Bit (CC));
2663 Lbit := Static_Integer (Last_Bit (CC));
2666 and then Fbit /= No_Uint
2667 and then Lbit /= No_Uint
2669 OC_Count := OC_Count + 1;
2670 Posit := Posit * SSU;
2671 OC_Fbit (OC_Count) := Fbit + Posit;
2672 OC_Lbit (OC_Count) := Lbit + Posit;
2679 Sorting.Sort (OC_Count);
2681 Overlap_Check_Required := False;
2682 for J in 1 .. OC_Count - 1 loop
2683 if OC_Lbit (J) >= OC_Fbit (J + 1) then
2684 Overlap_Check_Required := True;
2691 -- If Overlap_Check_Required is still True, then we have to do the full
2692 -- scale overlap check, since we have at least two fields that do
2693 -- overlap, and we need to know if that is OK since they are in
2694 -- different variant, or whether we have a definite problem.
2696 if Overlap_Check_Required then
2697 Overlap_Check2 : declare
2698 C1_Ent, C2_Ent : Entity_Id;
2699 -- Entities of components being checked for overlap
2702 -- Component_List node whose Component_Items are being checked
2705 -- Component declaration for component being checked
2708 C1_Ent := First_Entity (Base_Type (Rectype));
2710 -- Loop through all components in record. For each component check
2711 -- for overlap with any of the preceding elements on the component
2712 -- list containing the component and also, if the component is in
2713 -- a variant, check against components outside the case structure.
2714 -- This latter test is repeated recursively up the variant tree.
2716 Main_Component_Loop : while Present (C1_Ent) loop
2717 if Ekind (C1_Ent) /= E_Component
2718 and then Ekind (C1_Ent) /= E_Discriminant
2720 goto Continue_Main_Component_Loop;
2723 -- Skip overlap check if entity has no declaration node. This
2724 -- happens with discriminants in constrained derived types.
2725 -- Probably we are missing some checks as a result, but that
2726 -- does not seem terribly serious ???
2728 if No (Declaration_Node (C1_Ent)) then
2729 goto Continue_Main_Component_Loop;
2732 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
2734 -- Loop through component lists that need checking. Check the
2735 -- current component list and all lists in variants above us.
2737 Component_List_Loop : loop
2739 -- If derived type definition, go to full declaration
2740 -- If at outer level, check discriminants if there are any.
2742 if Nkind (Clist) = N_Derived_Type_Definition then
2743 Clist := Parent (Clist);
2746 -- Outer level of record definition, check discriminants
2748 if Nkind_In (Clist, N_Full_Type_Declaration,
2749 N_Private_Type_Declaration)
2751 if Has_Discriminants (Defining_Identifier (Clist)) then
2753 First_Discriminant (Defining_Identifier (Clist));
2755 while Present (C2_Ent) loop
2756 exit when C1_Ent = C2_Ent;
2757 Check_Component_Overlap (C1_Ent, C2_Ent);
2758 Next_Discriminant (C2_Ent);
2762 -- Record extension case
2764 elsif Nkind (Clist) = N_Derived_Type_Definition then
2767 -- Otherwise check one component list
2770 Citem := First (Component_Items (Clist));
2772 while Present (Citem) loop
2773 if Nkind (Citem) = N_Component_Declaration then
2774 C2_Ent := Defining_Identifier (Citem);
2775 exit when C1_Ent = C2_Ent;
2776 Check_Component_Overlap (C1_Ent, C2_Ent);
2783 -- Check for variants above us (the parent of the Clist can
2784 -- be a variant, in which case its parent is a variant part,
2785 -- and the parent of the variant part is a component list
2786 -- whose components must all be checked against the current
2787 -- component for overlap).
2789 if Nkind (Parent (Clist)) = N_Variant then
2790 Clist := Parent (Parent (Parent (Clist)));
2792 -- Check for possible discriminant part in record, this is
2793 -- treated essentially as another level in the recursion.
2794 -- For this case the parent of the component list is the
2795 -- record definition, and its parent is the full type
2796 -- declaration containing the discriminant specifications.
2798 elsif Nkind (Parent (Clist)) = N_Record_Definition then
2799 Clist := Parent (Parent ((Clist)));
2801 -- If neither of these two cases, we are at the top of
2805 exit Component_List_Loop;
2807 end loop Component_List_Loop;
2809 <<Continue_Main_Component_Loop>>
2810 Next_Entity (C1_Ent);
2812 end loop Main_Component_Loop;
2816 -- For records that have component clauses for all components, and whose
2817 -- size is less than or equal to 32, we need to know the size in the
2818 -- front end to activate possible packed array processing where the
2819 -- component type is a record.
2821 -- At this stage Hbit + 1 represents the first unused bit from all the
2822 -- component clauses processed, so if the component clauses are
2823 -- complete, then this is the length of the record.
2825 -- For records longer than System.Storage_Unit, and for those where not
2826 -- all components have component clauses, the back end determines the
2827 -- length (it may for example be appropriate to round up the size
2828 -- to some convenient boundary, based on alignment considerations, etc).
2830 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
2832 -- Nothing to do if at least one component has no component clause
2834 Comp := First_Component_Or_Discriminant (Rectype);
2835 while Present (Comp) loop
2836 exit when No (Component_Clause (Comp));
2837 Next_Component_Or_Discriminant (Comp);
2840 -- If we fall out of loop, all components have component clauses
2841 -- and so we can set the size to the maximum value.
2844 Set_RM_Size (Rectype, Hbit + 1);
2848 -- Check missing components if Complete_Representation pragma appeared
2850 if Present (CR_Pragma) then
2851 Comp := First_Component_Or_Discriminant (Rectype);
2852 while Present (Comp) loop
2853 if No (Component_Clause (Comp)) then
2855 ("missing component clause for &", CR_Pragma, Comp);
2858 Next_Component_Or_Discriminant (Comp);
2861 -- If no Complete_Representation pragma, warn if missing components
2863 elsif Warn_On_Unrepped_Components then
2865 Num_Repped_Components : Nat := 0;
2866 Num_Unrepped_Components : Nat := 0;
2869 -- First count number of repped and unrepped components
2871 Comp := First_Component_Or_Discriminant (Rectype);
2872 while Present (Comp) loop
2873 if Present (Component_Clause (Comp)) then
2874 Num_Repped_Components := Num_Repped_Components + 1;
2876 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2879 Next_Component_Or_Discriminant (Comp);
2882 -- We are only interested in the case where there is at least one
2883 -- unrepped component, and at least half the components have rep
2884 -- clauses. We figure that if less than half have them, then the
2885 -- partial rep clause is really intentional. If the component
2886 -- type has no underlying type set at this point (as for a generic
2887 -- formal type), we don't know enough to give a warning on the
2890 if Num_Unrepped_Components > 0
2891 and then Num_Unrepped_Components < Num_Repped_Components
2893 Comp := First_Component_Or_Discriminant (Rectype);
2894 while Present (Comp) loop
2895 if No (Component_Clause (Comp))
2896 and then Comes_From_Source (Comp)
2897 and then Present (Underlying_Type (Etype (Comp)))
2898 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2899 or else Size_Known_At_Compile_Time
2900 (Underlying_Type (Etype (Comp))))
2901 and then not Has_Warnings_Off (Rectype)
2903 Error_Msg_Sloc := Sloc (Comp);
2905 ("?no component clause given for & declared #",
2909 Next_Component_Or_Discriminant (Comp);
2914 end Analyze_Record_Representation_Clause;
2916 -----------------------------
2917 -- Check_Component_Overlap --
2918 -----------------------------
2920 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
2922 if Present (Component_Clause (C1_Ent))
2923 and then Present (Component_Clause (C2_Ent))
2925 -- Exclude odd case where we have two tag fields in the same record,
2926 -- both at location zero. This seems a bit strange, but it seems to
2927 -- happen in some circumstances ???
2929 if Chars (C1_Ent) = Name_uTag
2930 and then Chars (C2_Ent) = Name_uTag
2935 -- Here we check if the two fields overlap
2938 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
2939 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
2940 E1 : constant Uint := S1 + Esize (C1_Ent);
2941 E2 : constant Uint := S2 + Esize (C2_Ent);
2944 if E2 <= S1 or else E1 <= S2 then
2948 Component_Name (Component_Clause (C2_Ent));
2949 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
2951 Component_Name (Component_Clause (C1_Ent));
2953 ("component& overlaps & #",
2954 Component_Name (Component_Clause (C1_Ent)));
2958 end Check_Component_Overlap;
2960 -----------------------------------
2961 -- Check_Constant_Address_Clause --
2962 -----------------------------------
2964 procedure Check_Constant_Address_Clause
2968 procedure Check_At_Constant_Address (Nod : Node_Id);
2969 -- Checks that the given node N represents a name whose 'Address is
2970 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2971 -- address value is the same at the point of declaration of U_Ent and at
2972 -- the time of elaboration of the address clause.
2974 procedure Check_Expr_Constants (Nod : Node_Id);
2975 -- Checks that Nod meets the requirements for a constant address clause
2976 -- in the sense of the enclosing procedure.
2978 procedure Check_List_Constants (Lst : List_Id);
2979 -- Check that all elements of list Lst meet the requirements for a
2980 -- constant address clause in the sense of the enclosing procedure.
2982 -------------------------------
2983 -- Check_At_Constant_Address --
2984 -------------------------------
2986 procedure Check_At_Constant_Address (Nod : Node_Id) is
2988 if Is_Entity_Name (Nod) then
2989 if Present (Address_Clause (Entity ((Nod)))) then
2991 ("invalid address clause for initialized object &!",
2994 ("address for& cannot" &
2995 " depend on another address clause! (RM 13.1(22))!",
2998 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2999 and then Sloc (U_Ent) < Sloc (Entity (Nod))
3002 ("invalid address clause for initialized object &!",
3004 Error_Msg_Node_2 := U_Ent;
3006 ("\& must be defined before & (RM 13.1(22))!",
3010 elsif Nkind (Nod) = N_Selected_Component then
3012 T : constant Entity_Id := Etype (Prefix (Nod));
3015 if (Is_Record_Type (T)
3016 and then Has_Discriminants (T))
3019 and then Is_Record_Type (Designated_Type (T))
3020 and then Has_Discriminants (Designated_Type (T)))
3023 ("invalid address clause for initialized object &!",
3026 ("\address cannot depend on component" &
3027 " of discriminated record (RM 13.1(22))!",
3030 Check_At_Constant_Address (Prefix (Nod));
3034 elsif Nkind (Nod) = N_Indexed_Component then
3035 Check_At_Constant_Address (Prefix (Nod));
3036 Check_List_Constants (Expressions (Nod));
3039 Check_Expr_Constants (Nod);
3041 end Check_At_Constant_Address;
3043 --------------------------
3044 -- Check_Expr_Constants --
3045 --------------------------
3047 procedure Check_Expr_Constants (Nod : Node_Id) is
3048 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
3049 Ent : Entity_Id := Empty;
3052 if Nkind (Nod) in N_Has_Etype
3053 and then Etype (Nod) = Any_Type
3059 when N_Empty | N_Error =>
3062 when N_Identifier | N_Expanded_Name =>
3063 Ent := Entity (Nod);
3065 -- We need to look at the original node if it is different
3066 -- from the node, since we may have rewritten things and
3067 -- substituted an identifier representing the rewrite.
3069 if Original_Node (Nod) /= Nod then
3070 Check_Expr_Constants (Original_Node (Nod));
3072 -- If the node is an object declaration without initial
3073 -- value, some code has been expanded, and the expression
3074 -- is not constant, even if the constituents might be
3075 -- acceptable, as in A'Address + offset.
3077 if Ekind (Ent) = E_Variable
3079 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3081 No (Expression (Declaration_Node (Ent)))
3084 ("invalid address clause for initialized object &!",
3087 -- If entity is constant, it may be the result of expanding
3088 -- a check. We must verify that its declaration appears
3089 -- before the object in question, else we also reject the
3092 elsif Ekind (Ent) = E_Constant
3093 and then In_Same_Source_Unit (Ent, U_Ent)
3094 and then Sloc (Ent) > Loc_U_Ent
3097 ("invalid address clause for initialized object &!",
3104 -- Otherwise look at the identifier and see if it is OK
3106 if Ekind (Ent) = E_Named_Integer
3108 Ekind (Ent) = E_Named_Real
3115 Ekind (Ent) = E_Constant
3117 Ekind (Ent) = E_In_Parameter
3119 -- This is the case where we must have Ent defined before
3120 -- U_Ent. Clearly if they are in different units this
3121 -- requirement is met since the unit containing Ent is
3122 -- already processed.
3124 if not In_Same_Source_Unit (Ent, U_Ent) then
3127 -- Otherwise location of Ent must be before the location
3128 -- of U_Ent, that's what prior defined means.
3130 elsif Sloc (Ent) < Loc_U_Ent then
3135 ("invalid address clause for initialized object &!",
3137 Error_Msg_Node_2 := U_Ent;
3139 ("\& must be defined before & (RM 13.1(22))!",
3143 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3144 Check_Expr_Constants (Original_Node (Nod));
3148 ("invalid address clause for initialized object &!",
3151 if Comes_From_Source (Ent) then
3153 ("\reference to variable& not allowed"
3154 & " (RM 13.1(22))!", Nod, Ent);
3157 ("non-static expression not allowed"
3158 & " (RM 13.1(22))!", Nod);
3162 when N_Integer_Literal =>
3164 -- If this is a rewritten unchecked conversion, in a system
3165 -- where Address is an integer type, always use the base type
3166 -- for a literal value. This is user-friendly and prevents
3167 -- order-of-elaboration issues with instances of unchecked
3170 if Nkind (Original_Node (Nod)) = N_Function_Call then
3171 Set_Etype (Nod, Base_Type (Etype (Nod)));
3174 when N_Real_Literal |
3176 N_Character_Literal =>
3180 Check_Expr_Constants (Low_Bound (Nod));
3181 Check_Expr_Constants (High_Bound (Nod));
3183 when N_Explicit_Dereference =>
3184 Check_Expr_Constants (Prefix (Nod));
3186 when N_Indexed_Component =>
3187 Check_Expr_Constants (Prefix (Nod));
3188 Check_List_Constants (Expressions (Nod));
3191 Check_Expr_Constants (Prefix (Nod));
3192 Check_Expr_Constants (Discrete_Range (Nod));
3194 when N_Selected_Component =>
3195 Check_Expr_Constants (Prefix (Nod));
3197 when N_Attribute_Reference =>
3198 if Attribute_Name (Nod) = Name_Address
3200 Attribute_Name (Nod) = Name_Access
3202 Attribute_Name (Nod) = Name_Unchecked_Access
3204 Attribute_Name (Nod) = Name_Unrestricted_Access
3206 Check_At_Constant_Address (Prefix (Nod));
3209 Check_Expr_Constants (Prefix (Nod));
3210 Check_List_Constants (Expressions (Nod));
3214 Check_List_Constants (Component_Associations (Nod));
3215 Check_List_Constants (Expressions (Nod));
3217 when N_Component_Association =>
3218 Check_Expr_Constants (Expression (Nod));
3220 when N_Extension_Aggregate =>
3221 Check_Expr_Constants (Ancestor_Part (Nod));
3222 Check_List_Constants (Component_Associations (Nod));
3223 Check_List_Constants (Expressions (Nod));
3228 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3229 Check_Expr_Constants (Left_Opnd (Nod));
3230 Check_Expr_Constants (Right_Opnd (Nod));
3233 Check_Expr_Constants (Right_Opnd (Nod));
3235 when N_Type_Conversion |
3236 N_Qualified_Expression |
3238 Check_Expr_Constants (Expression (Nod));
3240 when N_Unchecked_Type_Conversion =>
3241 Check_Expr_Constants (Expression (Nod));
3243 -- If this is a rewritten unchecked conversion, subtypes in
3244 -- this node are those created within the instance. To avoid
3245 -- order of elaboration issues, replace them with their base
3246 -- types. Note that address clauses can cause order of
3247 -- elaboration problems because they are elaborated by the
3248 -- back-end at the point of definition, and may mention
3249 -- entities declared in between (as long as everything is
3250 -- static). It is user-friendly to allow unchecked conversions
3253 if Nkind (Original_Node (Nod)) = N_Function_Call then
3254 Set_Etype (Expression (Nod),
3255 Base_Type (Etype (Expression (Nod))));
3256 Set_Etype (Nod, Base_Type (Etype (Nod)));
3259 when N_Function_Call =>
3260 if not Is_Pure (Entity (Name (Nod))) then
3262 ("invalid address clause for initialized object &!",
3266 ("\function & is not pure (RM 13.1(22))!",
3267 Nod, Entity (Name (Nod)));
3270 Check_List_Constants (Parameter_Associations (Nod));
3273 when N_Parameter_Association =>
3274 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3278 ("invalid address clause for initialized object &!",
3281 ("\must be constant defined before& (RM 13.1(22))!",
3284 end Check_Expr_Constants;
3286 --------------------------
3287 -- Check_List_Constants --
3288 --------------------------
3290 procedure Check_List_Constants (Lst : List_Id) is
3294 if Present (Lst) then
3295 Nod1 := First (Lst);
3296 while Present (Nod1) loop
3297 Check_Expr_Constants (Nod1);
3301 end Check_List_Constants;
3303 -- Start of processing for Check_Constant_Address_Clause
3306 Check_Expr_Constants (Expr);
3307 end Check_Constant_Address_Clause;
3313 procedure Check_Size
3317 Biased : out Boolean)
3319 UT : constant Entity_Id := Underlying_Type (T);
3325 -- Dismiss cases for generic types or types with previous errors
3328 or else UT = Any_Type
3329 or else Is_Generic_Type (UT)
3330 or else Is_Generic_Type (Root_Type (UT))
3334 -- Check case of bit packed array
3336 elsif Is_Array_Type (UT)
3337 and then Known_Static_Component_Size (UT)
3338 and then Is_Bit_Packed_Array (UT)
3346 Asiz := Component_Size (UT);
3347 Indx := First_Index (UT);
3349 Ityp := Etype (Indx);
3351 -- If non-static bound, then we are not in the business of
3352 -- trying to check the length, and indeed an error will be
3353 -- issued elsewhere, since sizes of non-static array types
3354 -- cannot be set implicitly or explicitly.
3356 if not Is_Static_Subtype (Ityp) then
3360 -- Otherwise accumulate next dimension
3362 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
3363 Expr_Value (Type_Low_Bound (Ityp)) +
3367 exit when No (Indx);
3373 Error_Msg_Uint_1 := Asiz;
3375 ("size for& too small, minimum allowed is ^", N, T);
3376 Set_Esize (T, Asiz);
3377 Set_RM_Size (T, Asiz);
3381 -- All other composite types are ignored
3383 elsif Is_Composite_Type (UT) then
3386 -- For fixed-point types, don't check minimum if type is not frozen,
3387 -- since we don't know all the characteristics of the type that can
3388 -- affect the size (e.g. a specified small) till freeze time.
3390 elsif Is_Fixed_Point_Type (UT)
3391 and then not Is_Frozen (UT)
3395 -- Cases for which a minimum check is required
3398 -- Ignore if specified size is correct for the type
3400 if Known_Esize (UT) and then Siz = Esize (UT) then
3404 -- Otherwise get minimum size
3406 M := UI_From_Int (Minimum_Size (UT));
3410 -- Size is less than minimum size, but one possibility remains
3411 -- that we can manage with the new size if we bias the type.
3413 M := UI_From_Int (Minimum_Size (UT, Biased => True));
3416 Error_Msg_Uint_1 := M;
3418 ("size for& too small, minimum allowed is ^", N, T);
3428 -------------------------
3429 -- Get_Alignment_Value --
3430 -------------------------
3432 function Get_Alignment_Value (Expr : Node_Id) return Uint is
3433 Align : constant Uint := Static_Integer (Expr);
3436 if Align = No_Uint then
3439 elsif Align <= 0 then
3440 Error_Msg_N ("alignment value must be positive", Expr);
3444 for J in Int range 0 .. 64 loop
3446 M : constant Uint := Uint_2 ** J;
3449 exit when M = Align;
3453 ("alignment value must be power of 2", Expr);
3461 end Get_Alignment_Value;
3467 procedure Initialize is
3469 Unchecked_Conversions.Init;
3472 -------------------------
3473 -- Is_Operational_Item --
3474 -------------------------
3476 function Is_Operational_Item (N : Node_Id) return Boolean is
3478 if Nkind (N) /= N_Attribute_Definition_Clause then
3482 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
3484 return Id = Attribute_Input
3485 or else Id = Attribute_Output
3486 or else Id = Attribute_Read
3487 or else Id = Attribute_Write
3488 or else Id = Attribute_External_Tag;
3491 end Is_Operational_Item;
3497 function Minimum_Size
3499 Biased : Boolean := False) return Nat
3501 Lo : Uint := No_Uint;
3502 Hi : Uint := No_Uint;
3503 LoR : Ureal := No_Ureal;
3504 HiR : Ureal := No_Ureal;
3505 LoSet : Boolean := False;
3506 HiSet : Boolean := False;
3510 R_Typ : constant Entity_Id := Root_Type (T);
3513 -- If bad type, return 0
3515 if T = Any_Type then
3518 -- For generic types, just return zero. There cannot be any legitimate
3519 -- need to know such a size, but this routine may be called with a
3520 -- generic type as part of normal processing.
3522 elsif Is_Generic_Type (R_Typ)
3523 or else R_Typ = Any_Type
3527 -- Access types. Normally an access type cannot have a size smaller
3528 -- than the size of System.Address. The exception is on VMS, where
3529 -- we have short and long addresses, and it is possible for an access
3530 -- type to have a short address size (and thus be less than the size
3531 -- of System.Address itself). We simply skip the check for VMS, and
3532 -- leave it to the back end to do the check.
3534 elsif Is_Access_Type (T) then
3535 if OpenVMS_On_Target then
3538 return System_Address_Size;
3541 -- Floating-point types
3543 elsif Is_Floating_Point_Type (T) then
3544 return UI_To_Int (Esize (R_Typ));
3548 elsif Is_Discrete_Type (T) then
3550 -- The following loop is looking for the nearest compile time known
3551 -- bounds following the ancestor subtype chain. The idea is to find
3552 -- the most restrictive known bounds information.
3556 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3561 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
3562 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
3569 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
3570 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
3576 Ancest := Ancestor_Subtype (Ancest);
3579 Ancest := Base_Type (T);
3581 if Is_Generic_Type (Ancest) then
3587 -- Fixed-point types. We can't simply use Expr_Value to get the
3588 -- Corresponding_Integer_Value values of the bounds, since these do not
3589 -- get set till the type is frozen, and this routine can be called
3590 -- before the type is frozen. Similarly the test for bounds being static
3591 -- needs to include the case where we have unanalyzed real literals for
3594 elsif Is_Fixed_Point_Type (T) then
3596 -- The following loop is looking for the nearest compile time known
3597 -- bounds following the ancestor subtype chain. The idea is to find
3598 -- the most restrictive known bounds information.
3602 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3606 -- Note: In the following two tests for LoSet and HiSet, it may
3607 -- seem redundant to test for N_Real_Literal here since normally
3608 -- one would assume that the test for the value being known at
3609 -- compile time includes this case. However, there is a glitch.
3610 -- If the real literal comes from folding a non-static expression,
3611 -- then we don't consider any non- static expression to be known
3612 -- at compile time if we are in configurable run time mode (needed
3613 -- in some cases to give a clearer definition of what is and what
3614 -- is not accepted). So the test is indeed needed. Without it, we
3615 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
3618 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
3619 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
3621 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
3628 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
3629 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
3631 HiR := Expr_Value_R (Type_High_Bound (Ancest));
3637 Ancest := Ancestor_Subtype (Ancest);
3640 Ancest := Base_Type (T);
3642 if Is_Generic_Type (Ancest) then
3648 Lo := UR_To_Uint (LoR / Small_Value (T));
3649 Hi := UR_To_Uint (HiR / Small_Value (T));
3651 -- No other types allowed
3654 raise Program_Error;
3657 -- Fall through with Hi and Lo set. Deal with biased case
3660 and then not Is_Fixed_Point_Type (T)
3661 and then not (Is_Enumeration_Type (T)
3662 and then Has_Non_Standard_Rep (T)))
3663 or else Has_Biased_Representation (T)
3669 -- Signed case. Note that we consider types like range 1 .. -1 to be
3670 -- signed for the purpose of computing the size, since the bounds have
3671 -- to be accommodated in the base type.
3673 if Lo < 0 or else Hi < 0 then
3677 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
3678 -- Note that we accommodate the case where the bounds cross. This
3679 -- can happen either because of the way the bounds are declared
3680 -- or because of the algorithm in Freeze_Fixed_Point_Type.
3694 -- If both bounds are positive, make sure that both are represen-
3695 -- table in the case where the bounds are crossed. This can happen
3696 -- either because of the way the bounds are declared, or because of
3697 -- the algorithm in Freeze_Fixed_Point_Type.
3703 -- S = size, (can accommodate 0 .. (2**size - 1))
3706 while Hi >= Uint_2 ** S loop
3714 ---------------------------
3715 -- New_Stream_Subprogram --
3716 ---------------------------
3718 procedure New_Stream_Subprogram
3722 Nam : TSS_Name_Type)
3724 Loc : constant Source_Ptr := Sloc (N);
3725 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
3726 Subp_Id : Entity_Id;
3727 Subp_Decl : Node_Id;
3731 Defer_Declaration : constant Boolean :=
3732 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
3733 -- For a tagged type, there is a declaration for each stream attribute
3734 -- at the freeze point, and we must generate only a completion of this
3735 -- declaration. We do the same for private types, because the full view
3736 -- might be tagged. Otherwise we generate a declaration at the point of
3737 -- the attribute definition clause.
3739 function Build_Spec return Node_Id;
3740 -- Used for declaration and renaming declaration, so that this is
3741 -- treated as a renaming_as_body.
3747 function Build_Spec return Node_Id is
3748 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
3751 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
3754 Subp_Id := Make_Defining_Identifier (Loc, Sname);
3756 -- S : access Root_Stream_Type'Class
3758 Formals := New_List (
3759 Make_Parameter_Specification (Loc,
3760 Defining_Identifier =>
3761 Make_Defining_Identifier (Loc, Name_S),
3763 Make_Access_Definition (Loc,
3766 Designated_Type (Etype (F)), Loc))));
3768 if Nam = TSS_Stream_Input then
3769 Spec := Make_Function_Specification (Loc,
3770 Defining_Unit_Name => Subp_Id,
3771 Parameter_Specifications => Formals,
3772 Result_Definition => T_Ref);
3777 Make_Parameter_Specification (Loc,
3778 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
3779 Out_Present => Out_P,
3780 Parameter_Type => T_Ref));
3782 Spec := Make_Procedure_Specification (Loc,
3783 Defining_Unit_Name => Subp_Id,
3784 Parameter_Specifications => Formals);
3790 -- Start of processing for New_Stream_Subprogram
3793 F := First_Formal (Subp);
3795 if Ekind (Subp) = E_Procedure then
3796 Etyp := Etype (Next_Formal (F));
3798 Etyp := Etype (Subp);
3801 -- Prepare subprogram declaration and insert it as an action on the
3802 -- clause node. The visibility for this entity is used to test for
3803 -- visibility of the attribute definition clause (in the sense of
3804 -- 8.3(23) as amended by AI-195).
3806 if not Defer_Declaration then
3808 Make_Subprogram_Declaration (Loc,
3809 Specification => Build_Spec);
3811 -- For a tagged type, there is always a visible declaration for each
3812 -- stream TSS (it is a predefined primitive operation), and the
3813 -- completion of this declaration occurs at the freeze point, which is
3814 -- not always visible at places where the attribute definition clause is
3815 -- visible. So, we create a dummy entity here for the purpose of
3816 -- tracking the visibility of the attribute definition clause itself.
3820 Make_Defining_Identifier (Loc,
3821 Chars => New_External_Name (Sname, 'V'));
3823 Make_Object_Declaration (Loc,
3824 Defining_Identifier => Subp_Id,
3825 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
3828 Insert_Action (N, Subp_Decl);
3829 Set_Entity (N, Subp_Id);
3832 Make_Subprogram_Renaming_Declaration (Loc,
3833 Specification => Build_Spec,
3834 Name => New_Reference_To (Subp, Loc));
3836 if Defer_Declaration then
3837 Set_TSS (Base_Type (Ent), Subp_Id);
3839 Insert_Action (N, Subp_Decl);
3840 Copy_TSS (Subp_Id, Base_Type (Ent));
3842 end New_Stream_Subprogram;
3844 ------------------------
3845 -- Rep_Item_Too_Early --
3846 ------------------------
3848 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
3850 -- Cannot apply non-operational rep items to generic types
3852 if Is_Operational_Item (N) then
3856 and then Is_Generic_Type (Root_Type (T))
3859 ("representation item not allowed for generic type", N);
3863 -- Otherwise check for incomplete type
3865 if Is_Incomplete_Or_Private_Type (T)
3866 and then No (Underlying_Type (T))
3869 ("representation item must be after full type declaration", N);
3872 -- If the type has incomplete components, a representation clause is
3873 -- illegal but stream attributes and Convention pragmas are correct.
3875 elsif Has_Private_Component (T) then
3876 if Nkind (N) = N_Pragma then
3880 ("representation item must appear after type is fully defined",
3887 end Rep_Item_Too_Early;
3889 -----------------------
3890 -- Rep_Item_Too_Late --
3891 -----------------------
3893 function Rep_Item_Too_Late
3896 FOnly : Boolean := False) return Boolean
3899 Parent_Type : Entity_Id;
3902 -- Output the too late message. Note that this is not considered a
3903 -- serious error, since the effect is simply that we ignore the
3904 -- representation clause in this case.
3910 procedure Too_Late is
3912 Error_Msg_N ("|representation item appears too late!", N);
3915 -- Start of processing for Rep_Item_Too_Late
3918 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
3919 -- types, which may be frozen if they appear in a representation clause
3920 -- for a local type.
3923 and then not From_With_Type (T)
3926 S := First_Subtype (T);
3928 if Present (Freeze_Node (S)) then
3930 ("?no more representation items for }", Freeze_Node (S), S);
3935 -- Check for case of non-tagged derived type whose parent either has
3936 -- primitive operations, or is a by reference type (RM 13.1(10)).
3940 and then Is_Derived_Type (T)
3941 and then not Is_Tagged_Type (T)
3943 Parent_Type := Etype (Base_Type (T));
3945 if Has_Primitive_Operations (Parent_Type) then
3948 ("primitive operations already defined for&!", N, Parent_Type);
3951 elsif Is_By_Reference_Type (Parent_Type) then
3954 ("parent type & is a by reference type!", N, Parent_Type);
3959 -- No error, link item into head of chain of rep items for the entity,
3960 -- but avoid chaining if we have an overloadable entity, and the pragma
3961 -- is one that can apply to multiple overloaded entities.
3963 if Is_Overloadable (T)
3964 and then Nkind (N) = N_Pragma
3967 Pname : constant Name_Id := Pragma_Name (N);
3969 if Pname = Name_Convention or else
3970 Pname = Name_Import or else
3971 Pname = Name_Export or else
3972 Pname = Name_External or else
3973 Pname = Name_Interface
3980 Record_Rep_Item (T, N);
3982 end Rep_Item_Too_Late;
3984 -------------------------
3985 -- Same_Representation --
3986 -------------------------
3988 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
3989 T1 : constant Entity_Id := Underlying_Type (Typ1);
3990 T2 : constant Entity_Id := Underlying_Type (Typ2);
3993 -- A quick check, if base types are the same, then we definitely have
3994 -- the same representation, because the subtype specific representation
3995 -- attributes (Size and Alignment) do not affect representation from
3996 -- the point of view of this test.
3998 if Base_Type (T1) = Base_Type (T2) then
4001 elsif Is_Private_Type (Base_Type (T2))
4002 and then Base_Type (T1) = Full_View (Base_Type (T2))
4007 -- Tagged types never have differing representations
4009 if Is_Tagged_Type (T1) then
4013 -- Representations are definitely different if conventions differ
4015 if Convention (T1) /= Convention (T2) then
4019 -- Representations are different if component alignments differ
4021 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4023 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4024 and then Component_Alignment (T1) /= Component_Alignment (T2)
4029 -- For arrays, the only real issue is component size. If we know the
4030 -- component size for both arrays, and it is the same, then that's
4031 -- good enough to know we don't have a change of representation.
4033 if Is_Array_Type (T1) then
4034 if Known_Component_Size (T1)
4035 and then Known_Component_Size (T2)
4036 and then Component_Size (T1) = Component_Size (T2)
4042 -- Types definitely have same representation if neither has non-standard
4043 -- representation since default representations are always consistent.
4044 -- If only one has non-standard representation, and the other does not,
4045 -- then we consider that they do not have the same representation. They
4046 -- might, but there is no way of telling early enough.
4048 if Has_Non_Standard_Rep (T1) then
4049 if not Has_Non_Standard_Rep (T2) then
4053 return not Has_Non_Standard_Rep (T2);
4056 -- Here the two types both have non-standard representation, and we need
4057 -- to determine if they have the same non-standard representation.
4059 -- For arrays, we simply need to test if the component sizes are the
4060 -- same. Pragma Pack is reflected in modified component sizes, so this
4061 -- check also deals with pragma Pack.
4063 if Is_Array_Type (T1) then
4064 return Component_Size (T1) = Component_Size (T2);
4066 -- Tagged types always have the same representation, because it is not
4067 -- possible to specify different representations for common fields.
4069 elsif Is_Tagged_Type (T1) then
4072 -- Case of record types
4074 elsif Is_Record_Type (T1) then
4076 -- Packed status must conform
4078 if Is_Packed (T1) /= Is_Packed (T2) then
4081 -- Otherwise we must check components. Typ2 maybe a constrained
4082 -- subtype with fewer components, so we compare the components
4083 -- of the base types.
4086 Record_Case : declare
4087 CD1, CD2 : Entity_Id;
4089 function Same_Rep return Boolean;
4090 -- CD1 and CD2 are either components or discriminants. This
4091 -- function tests whether the two have the same representation
4097 function Same_Rep return Boolean is
4099 if No (Component_Clause (CD1)) then
4100 return No (Component_Clause (CD2));
4104 Present (Component_Clause (CD2))
4106 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4108 Esize (CD1) = Esize (CD2);
4112 -- Start of processing for Record_Case
4115 if Has_Discriminants (T1) then
4116 CD1 := First_Discriminant (T1);
4117 CD2 := First_Discriminant (T2);
4119 -- The number of discriminants may be different if the
4120 -- derived type has fewer (constrained by values). The
4121 -- invisible discriminants retain the representation of
4122 -- the original, so the discrepancy does not per se
4123 -- indicate a different representation.
4126 and then Present (CD2)
4128 if not Same_Rep then
4131 Next_Discriminant (CD1);
4132 Next_Discriminant (CD2);
4137 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4138 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4140 while Present (CD1) loop
4141 if not Same_Rep then
4144 Next_Component (CD1);
4145 Next_Component (CD2);
4153 -- For enumeration types, we must check each literal to see if the
4154 -- representation is the same. Note that we do not permit enumeration
4155 -- representation clauses for Character and Wide_Character, so these
4156 -- cases were already dealt with.
4158 elsif Is_Enumeration_Type (T1) then
4160 Enumeration_Case : declare
4164 L1 := First_Literal (T1);
4165 L2 := First_Literal (T2);
4167 while Present (L1) loop
4168 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4178 end Enumeration_Case;
4180 -- Any other types have the same representation for these purposes
4185 end Same_Representation;
4187 --------------------
4188 -- Set_Enum_Esize --
4189 --------------------
4191 procedure Set_Enum_Esize (T : Entity_Id) is
4199 -- Find the minimum standard size (8,16,32,64) that fits
4201 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4202 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4205 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4206 Sz := Standard_Character_Size; -- May be > 8 on some targets
4208 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4211 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4214 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4219 if Hi < Uint_2**08 then
4220 Sz := Standard_Character_Size; -- May be > 8 on some targets
4222 elsif Hi < Uint_2**16 then
4225 elsif Hi < Uint_2**32 then
4228 else pragma Assert (Hi < Uint_2**63);
4233 -- That minimum is the proper size unless we have a foreign convention
4234 -- and the size required is 32 or less, in which case we bump the size
4235 -- up to 32. This is required for C and C++ and seems reasonable for
4236 -- all other foreign conventions.
4238 if Has_Foreign_Convention (T)
4239 and then Esize (T) < Standard_Integer_Size
4241 Init_Esize (T, Standard_Integer_Size);
4247 ------------------------------
4248 -- Validate_Address_Clauses --
4249 ------------------------------
4251 procedure Validate_Address_Clauses is
4253 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4255 ACCR : Address_Clause_Check_Record
4256 renames Address_Clause_Checks.Table (J);
4265 -- Skip processing of this entry if warning already posted
4267 if not Address_Warning_Posted (ACCR.N) then
4269 -- Get alignments. Really we should always have the alignment
4270 -- of the objects properly back annotated, but right now the
4271 -- back end fails to back annotate for address clauses???
4273 if Known_Alignment (ACCR.X) then
4274 X_Alignment := Alignment (ACCR.X);
4276 X_Alignment := Alignment (Etype (ACCR.X));
4279 if Known_Alignment (ACCR.Y) then
4280 Y_Alignment := Alignment (ACCR.Y);
4282 Y_Alignment := Alignment (Etype (ACCR.Y));
4285 -- Similarly obtain sizes
4287 if Known_Esize (ACCR.X) then
4288 X_Size := Esize (ACCR.X);
4290 X_Size := Esize (Etype (ACCR.X));
4293 if Known_Esize (ACCR.Y) then
4294 Y_Size := Esize (ACCR.Y);
4296 Y_Size := Esize (Etype (ACCR.Y));
4299 -- Check for large object overlaying smaller one
4302 and then X_Size > Uint_0
4303 and then X_Size > Y_Size
4306 ("?size for overlaid object is too small", ACCR.N);
4307 Error_Msg_Uint_1 := X_Size;
4309 ("\?size of & is ^", ACCR.N, ACCR.X);
4310 Error_Msg_Uint_1 := Y_Size;
4312 ("\?size of & is ^", ACCR.N, ACCR.Y);
4314 -- Check for inadequate alignment. Again the defensive check
4315 -- on Y_Alignment should not be needed, but because of the
4316 -- failure in back end annotation, we can have an alignment
4319 -- Note: we do not check alignments if we gave a size
4320 -- warning, since it would likely be redundant.
4322 elsif Y_Alignment /= Uint_0
4323 and then Y_Alignment < X_Alignment
4326 ("?specified address for& may be inconsistent "
4330 ("\?program execution may be erroneous (RM 13.3(27))",
4332 Error_Msg_Uint_1 := X_Alignment;
4334 ("\?alignment of & is ^",
4336 Error_Msg_Uint_1 := Y_Alignment;
4338 ("\?alignment of & is ^",
4344 end Validate_Address_Clauses;
4346 -----------------------------------
4347 -- Validate_Unchecked_Conversion --
4348 -----------------------------------
4350 procedure Validate_Unchecked_Conversion
4352 Act_Unit : Entity_Id)
4359 -- Obtain source and target types. Note that we call Ancestor_Subtype
4360 -- here because the processing for generic instantiation always makes
4361 -- subtypes, and we want the original frozen actual types.
4363 -- If we are dealing with private types, then do the check on their
4364 -- fully declared counterparts if the full declarations have been
4365 -- encountered (they don't have to be visible, but they must exist!)
4367 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
4369 if Is_Private_Type (Source)
4370 and then Present (Underlying_Type (Source))
4372 Source := Underlying_Type (Source);
4375 Target := Ancestor_Subtype (Etype (Act_Unit));
4377 -- If either type is generic, the instantiation happens within a generic
4378 -- unit, and there is nothing to check. The proper check
4379 -- will happen when the enclosing generic is instantiated.
4381 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
4385 if Is_Private_Type (Target)
4386 and then Present (Underlying_Type (Target))
4388 Target := Underlying_Type (Target);
4391 -- Source may be unconstrained array, but not target
4393 if Is_Array_Type (Target)
4394 and then not Is_Constrained (Target)
4397 ("unchecked conversion to unconstrained array not allowed", N);
4401 -- Warn if conversion between two different convention pointers
4403 if Is_Access_Type (Target)
4404 and then Is_Access_Type (Source)
4405 and then Convention (Target) /= Convention (Source)
4406 and then Warn_On_Unchecked_Conversion
4408 -- Give warnings for subprogram pointers only on most targets. The
4409 -- exception is VMS, where data pointers can have different lengths
4410 -- depending on the pointer convention.
4412 if Is_Access_Subprogram_Type (Target)
4413 or else Is_Access_Subprogram_Type (Source)
4414 or else OpenVMS_On_Target
4417 ("?conversion between pointers with different conventions!", N);
4421 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4422 -- warning when compiling GNAT-related sources.
4424 if Warn_On_Unchecked_Conversion
4425 and then not In_Predefined_Unit (N)
4426 and then RTU_Loaded (Ada_Calendar)
4428 (Chars (Source) = Name_Time
4430 Chars (Target) = Name_Time)
4432 -- If Ada.Calendar is loaded and the name of one of the operands is
4433 -- Time, there is a good chance that this is Ada.Calendar.Time.
4436 Calendar_Time : constant Entity_Id :=
4437 Full_View (RTE (RO_CA_Time));
4439 pragma Assert (Present (Calendar_Time));
4441 if Source = Calendar_Time
4442 or else Target = Calendar_Time
4445 ("?representation of 'Time values may change between " &
4446 "'G'N'A'T versions", N);
4451 -- Make entry in unchecked conversion table for later processing by
4452 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4453 -- (using values set by the back-end where possible). This is only done
4454 -- if the appropriate warning is active.
4456 if Warn_On_Unchecked_Conversion then
4457 Unchecked_Conversions.Append
4458 (New_Val => UC_Entry'
4463 -- If both sizes are known statically now, then back end annotation
4464 -- is not required to do a proper check but if either size is not
4465 -- known statically, then we need the annotation.
4467 if Known_Static_RM_Size (Source)
4468 and then Known_Static_RM_Size (Target)
4472 Back_Annotate_Rep_Info := True;
4476 -- If unchecked conversion to access type, and access type is declared
4477 -- in the same unit as the unchecked conversion, then set the
4478 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4481 if Is_Access_Type (Target) and then
4482 In_Same_Source_Unit (Target, N)
4484 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4487 -- Generate N_Validate_Unchecked_Conversion node for back end in
4488 -- case the back end needs to perform special validation checks.
4490 -- Shouldn't this be in Exp_Ch13, since the check only gets done
4491 -- if we have full expansion and the back end is called ???
4494 Make_Validate_Unchecked_Conversion (Sloc (N));
4495 Set_Source_Type (Vnode, Source);
4496 Set_Target_Type (Vnode, Target);
4498 -- If the unchecked conversion node is in a list, just insert before it.
4499 -- If not we have some strange case, not worth bothering about.
4501 if Is_List_Member (N) then
4502 Insert_After (N, Vnode);
4504 end Validate_Unchecked_Conversion;
4506 ------------------------------------
4507 -- Validate_Unchecked_Conversions --
4508 ------------------------------------
4510 procedure Validate_Unchecked_Conversions is
4512 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4514 T : UC_Entry renames Unchecked_Conversions.Table (N);
4516 Eloc : constant Source_Ptr := T.Eloc;
4517 Source : constant Entity_Id := T.Source;
4518 Target : constant Entity_Id := T.Target;
4524 -- This validation check, which warns if we have unequal sizes for
4525 -- unchecked conversion, and thus potentially implementation
4526 -- dependent semantics, is one of the few occasions on which we
4527 -- use the official RM size instead of Esize. See description in
4528 -- Einfo "Handling of Type'Size Values" for details.
4530 if Serious_Errors_Detected = 0
4531 and then Known_Static_RM_Size (Source)
4532 and then Known_Static_RM_Size (Target)
4534 -- Don't do the check if warnings off for either type, note the
4535 -- deliberate use of OR here instead of OR ELSE to get the flag
4536 -- Warnings_Off_Used set for both types if appropriate.
4538 and then not (Has_Warnings_Off (Source)
4540 Has_Warnings_Off (Target))
4542 Source_Siz := RM_Size (Source);
4543 Target_Siz := RM_Size (Target);
4545 if Source_Siz /= Target_Siz then
4547 ("?types for unchecked conversion have different sizes!",
4550 if All_Errors_Mode then
4551 Error_Msg_Name_1 := Chars (Source);
4552 Error_Msg_Uint_1 := Source_Siz;
4553 Error_Msg_Name_2 := Chars (Target);
4554 Error_Msg_Uint_2 := Target_Siz;
4555 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
4557 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4559 if Is_Discrete_Type (Source)
4560 and then Is_Discrete_Type (Target)
4562 if Source_Siz > Target_Siz then
4564 ("\?^ high order bits of source will be ignored!",
4567 elsif Is_Unsigned_Type (Source) then
4569 ("\?source will be extended with ^ high order " &
4570 "zero bits?!", Eloc);
4574 ("\?source will be extended with ^ high order " &
4579 elsif Source_Siz < Target_Siz then
4580 if Is_Discrete_Type (Target) then
4581 if Bytes_Big_Endian then
4583 ("\?target value will include ^ undefined " &
4588 ("\?target value will include ^ undefined " &
4595 ("\?^ trailing bits of target value will be " &
4596 "undefined!", Eloc);
4599 else pragma Assert (Source_Siz > Target_Siz);
4601 ("\?^ trailing bits of source will be ignored!",
4608 -- If both types are access types, we need to check the alignment.
4609 -- If the alignment of both is specified, we can do it here.
4611 if Serious_Errors_Detected = 0
4612 and then Ekind (Source) in Access_Kind
4613 and then Ekind (Target) in Access_Kind
4614 and then Target_Strict_Alignment
4615 and then Present (Designated_Type (Source))
4616 and then Present (Designated_Type (Target))
4619 D_Source : constant Entity_Id := Designated_Type (Source);
4620 D_Target : constant Entity_Id := Designated_Type (Target);
4623 if Known_Alignment (D_Source)
4624 and then Known_Alignment (D_Target)
4627 Source_Align : constant Uint := Alignment (D_Source);
4628 Target_Align : constant Uint := Alignment (D_Target);
4631 if Source_Align < Target_Align
4632 and then not Is_Tagged_Type (D_Source)
4634 -- Suppress warning if warnings suppressed on either
4635 -- type or either designated type. Note the use of
4636 -- OR here instead of OR ELSE. That is intentional,
4637 -- we would like to set flag Warnings_Off_Used in
4638 -- all types for which warnings are suppressed.
4640 and then not (Has_Warnings_Off (D_Source)
4642 Has_Warnings_Off (D_Target)
4644 Has_Warnings_Off (Source)
4646 Has_Warnings_Off (Target))
4648 Error_Msg_Uint_1 := Target_Align;
4649 Error_Msg_Uint_2 := Source_Align;
4650 Error_Msg_Node_1 := D_Target;
4651 Error_Msg_Node_2 := D_Source;
4653 ("?alignment of & (^) is stricter than " &
4654 "alignment of & (^)!", Eloc);
4656 ("\?resulting access value may have invalid " &
4657 "alignment!", Eloc);
4665 end Validate_Unchecked_Conversions;