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 Ekind (Aent) /= E_Constant
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 Is_Exported (U_Ent) then
982 ("& cannot be exported if an address clause is given",
985 ("\define and export a variable " &
986 "that holds its address instead",
990 -- Entity has delayed freeze, so we will generate an
991 -- alignment check at the freeze point unless suppressed.
993 if not Range_Checks_Suppressed (U_Ent)
994 and then not Alignment_Checks_Suppressed (U_Ent)
996 Set_Check_Address_Alignment (N);
999 -- Kill the size check code, since we are not allocating
1000 -- the variable, it is somewhere else.
1002 Kill_Size_Check_Code (U_Ent);
1005 -- If the address clause is of the form:
1007 -- for Y'Address use X'Address
1011 -- Const : constant Address := X'Address;
1013 -- for Y'Address use Const;
1015 -- then we make an entry in the table for checking the size and
1016 -- alignment of the overlaying variable. We defer this check
1017 -- till after code generation to take full advantage of the
1018 -- annotation done by the back end. This entry is only made if
1019 -- we have not already posted a warning about size/alignment
1020 -- (some warnings of this type are posted in Checks), and if
1021 -- the address clause comes from source.
1023 if Address_Clause_Overlay_Warnings
1024 and then Comes_From_Source (N)
1027 Ent_X : Entity_Id := Empty;
1028 Ent_Y : Entity_Id := Empty;
1031 Ent_Y := Find_Overlaid_Object (N);
1033 if Present (Ent_Y) and then Is_Entity_Name (Name (N)) then
1034 Ent_X := Entity (Name (N));
1035 Address_Clause_Checks.Append ((N, Ent_X, Ent_Y));
1037 -- If variable overlays a constant view, and we are
1038 -- warning on overlays, then mark the variable as
1039 -- overlaying a constant (we will give warnings later
1040 -- if this variable is assigned).
1042 if Is_Constant_Object (Ent_Y)
1043 and then Ekind (Ent_X) = E_Variable
1045 Set_Overlays_Constant (Ent_X);
1051 -- Not a valid entity for an address clause
1054 Error_Msg_N ("address cannot be given for &", Nam);
1062 -- Alignment attribute definition clause
1064 when Attribute_Alignment => Alignment_Block : declare
1065 Align : constant Uint := Get_Alignment_Value (Expr);
1070 if not Is_Type (U_Ent)
1071 and then Ekind (U_Ent) /= E_Variable
1072 and then Ekind (U_Ent) /= E_Constant
1074 Error_Msg_N ("alignment cannot be given for &", Nam);
1076 elsif Has_Alignment_Clause (U_Ent) then
1077 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1078 Error_Msg_N ("alignment clause previously given#", N);
1080 elsif Align /= No_Uint then
1081 Set_Has_Alignment_Clause (U_Ent);
1082 Set_Alignment (U_Ent, Align);
1084 end Alignment_Block;
1090 -- Bit_Order attribute definition clause
1092 when Attribute_Bit_Order => Bit_Order : declare
1094 if not Is_Record_Type (U_Ent) then
1096 ("Bit_Order can only be defined for record type", Nam);
1099 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1101 if Etype (Expr) = Any_Type then
1104 elsif not Is_Static_Expression (Expr) then
1105 Flag_Non_Static_Expr
1106 ("Bit_Order requires static expression!", Expr);
1109 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1110 Set_Reverse_Bit_Order (U_Ent, True);
1116 --------------------
1117 -- Component_Size --
1118 --------------------
1120 -- Component_Size attribute definition clause
1122 when Attribute_Component_Size => Component_Size_Case : declare
1123 Csize : constant Uint := Static_Integer (Expr);
1126 New_Ctyp : Entity_Id;
1130 if not Is_Array_Type (U_Ent) then
1131 Error_Msg_N ("component size requires array type", Nam);
1135 Btype := Base_Type (U_Ent);
1137 if Has_Component_Size_Clause (Btype) then
1139 ("component size clause for& previously given", Nam);
1141 elsif Csize /= No_Uint then
1142 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
1144 if Has_Aliased_Components (Btype)
1147 and then Csize /= 16
1150 ("component size incorrect for aliased components", N);
1154 -- For the biased case, build a declaration for a subtype
1155 -- that will be used to represent the biased subtype that
1156 -- reflects the biased representation of components. We need
1157 -- this subtype to get proper conversions on referencing
1158 -- elements of the array. Note that component size clauses
1159 -- are ignored in VM mode.
1161 if VM_Target = No_VM then
1164 Make_Defining_Identifier (Loc,
1166 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1169 Make_Subtype_Declaration (Loc,
1170 Defining_Identifier => New_Ctyp,
1171 Subtype_Indication =>
1172 New_Occurrence_Of (Component_Type (Btype), Loc));
1174 Set_Parent (Decl, N);
1175 Analyze (Decl, Suppress => All_Checks);
1177 Set_Has_Delayed_Freeze (New_Ctyp, False);
1178 Set_Esize (New_Ctyp, Csize);
1179 Set_RM_Size (New_Ctyp, Csize);
1180 Init_Alignment (New_Ctyp);
1181 Set_Has_Biased_Representation (New_Ctyp, True);
1182 Set_Is_Itype (New_Ctyp, True);
1183 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1185 Set_Component_Type (Btype, New_Ctyp);
1187 if Warn_On_Biased_Representation then
1189 ("?component size clause forces biased "
1190 & "representation", N);
1194 Set_Component_Size (Btype, Csize);
1196 -- For VM case, we ignore component size clauses
1199 -- Give a warning unless we are in GNAT mode, in which case
1200 -- the warning is suppressed since it is not useful.
1202 if not GNAT_Mode then
1204 ("?component size ignored in this configuration", N);
1208 Set_Has_Component_Size_Clause (Btype, True);
1209 Set_Has_Non_Standard_Rep (Btype, True);
1211 end Component_Size_Case;
1217 when Attribute_External_Tag => External_Tag :
1219 if not Is_Tagged_Type (U_Ent) then
1220 Error_Msg_N ("should be a tagged type", Nam);
1223 Analyze_And_Resolve (Expr, Standard_String);
1225 if not Is_Static_Expression (Expr) then
1226 Flag_Non_Static_Expr
1227 ("static string required for tag name!", Nam);
1230 if VM_Target = No_VM then
1231 Set_Has_External_Tag_Rep_Clause (U_Ent);
1232 elsif not Inspector_Mode then
1233 Error_Msg_Name_1 := Attr;
1235 ("% attribute unsupported in this configuration", Nam);
1238 if not Is_Library_Level_Entity (U_Ent) then
1240 ("?non-unique external tag supplied for &", N, U_Ent);
1242 ("?\same external tag applies to all subprogram calls", N);
1244 ("?\corresponding internal tag cannot be obtained", N);
1252 when Attribute_Input =>
1253 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1254 Set_Has_Specified_Stream_Input (Ent);
1260 -- Machine radix attribute definition clause
1262 when Attribute_Machine_Radix => Machine_Radix : declare
1263 Radix : constant Uint := Static_Integer (Expr);
1266 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1267 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1269 elsif Has_Machine_Radix_Clause (U_Ent) then
1270 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1271 Error_Msg_N ("machine radix clause previously given#", N);
1273 elsif Radix /= No_Uint then
1274 Set_Has_Machine_Radix_Clause (U_Ent);
1275 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1279 elsif Radix = 10 then
1280 Set_Machine_Radix_10 (U_Ent);
1282 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1291 -- Object_Size attribute definition clause
1293 when Attribute_Object_Size => Object_Size : declare
1294 Size : constant Uint := Static_Integer (Expr);
1297 pragma Warnings (Off, Biased);
1300 if not Is_Type (U_Ent) then
1301 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1303 elsif Has_Object_Size_Clause (U_Ent) then
1304 Error_Msg_N ("Object_Size already given for &", Nam);
1307 Check_Size (Expr, U_Ent, Size, Biased);
1315 UI_Mod (Size, 64) /= 0
1318 ("Object_Size must be 8, 16, 32, or multiple of 64",
1322 Set_Esize (U_Ent, Size);
1323 Set_Has_Object_Size_Clause (U_Ent);
1324 Alignment_Check_For_Esize_Change (U_Ent);
1332 when Attribute_Output =>
1333 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1334 Set_Has_Specified_Stream_Output (Ent);
1340 when Attribute_Read =>
1341 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1342 Set_Has_Specified_Stream_Read (Ent);
1348 -- Size attribute definition clause
1350 when Attribute_Size => Size : declare
1351 Size : constant Uint := Static_Integer (Expr);
1358 if Has_Size_Clause (U_Ent) then
1359 Error_Msg_N ("size already given for &", Nam);
1361 elsif not Is_Type (U_Ent)
1362 and then Ekind (U_Ent) /= E_Variable
1363 and then Ekind (U_Ent) /= E_Constant
1365 Error_Msg_N ("size cannot be given for &", Nam);
1367 elsif Is_Array_Type (U_Ent)
1368 and then not Is_Constrained (U_Ent)
1371 ("size cannot be given for unconstrained array", Nam);
1373 elsif Size /= No_Uint then
1374 if Is_Type (U_Ent) then
1377 Etyp := Etype (U_Ent);
1380 -- Check size, note that Gigi is in charge of checking that the
1381 -- size of an array or record type is OK. Also we do not check
1382 -- the size in the ordinary fixed-point case, since it is too
1383 -- early to do so (there may be subsequent small clause that
1384 -- affects the size). We can check the size if a small clause
1385 -- has already been given.
1387 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1388 or else Has_Small_Clause (U_Ent)
1390 Check_Size (Expr, Etyp, Size, Biased);
1391 Set_Has_Biased_Representation (U_Ent, Biased);
1393 if Biased and Warn_On_Biased_Representation then
1395 ("?size clause forces biased representation", N);
1399 -- For types set RM_Size and Esize if possible
1401 if Is_Type (U_Ent) then
1402 Set_RM_Size (U_Ent, Size);
1404 -- For scalar types, increase Object_Size to power of 2, but
1405 -- not less than a storage unit in any case (i.e., normally
1406 -- this means it will be byte addressable).
1408 if Is_Scalar_Type (U_Ent) then
1409 if Size <= System_Storage_Unit then
1410 Init_Esize (U_Ent, System_Storage_Unit);
1411 elsif Size <= 16 then
1412 Init_Esize (U_Ent, 16);
1413 elsif Size <= 32 then
1414 Init_Esize (U_Ent, 32);
1416 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1419 -- For all other types, object size = value size. The
1420 -- backend will adjust as needed.
1423 Set_Esize (U_Ent, Size);
1426 Alignment_Check_For_Esize_Change (U_Ent);
1428 -- For objects, set Esize only
1431 if Is_Elementary_Type (Etyp) then
1432 if Size /= System_Storage_Unit
1434 Size /= System_Storage_Unit * 2
1436 Size /= System_Storage_Unit * 4
1438 Size /= System_Storage_Unit * 8
1440 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1441 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1443 ("size for primitive object must be a power of 2"
1444 & " in the range ^-^", N);
1448 Set_Esize (U_Ent, Size);
1451 Set_Has_Size_Clause (U_Ent);
1459 -- Small attribute definition clause
1461 when Attribute_Small => Small : declare
1462 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1466 Analyze_And_Resolve (Expr, Any_Real);
1468 if Etype (Expr) = Any_Type then
1471 elsif not Is_Static_Expression (Expr) then
1472 Flag_Non_Static_Expr
1473 ("small requires static expression!", Expr);
1477 Small := Expr_Value_R (Expr);
1479 if Small <= Ureal_0 then
1480 Error_Msg_N ("small value must be greater than zero", Expr);
1486 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1488 ("small requires an ordinary fixed point type", Nam);
1490 elsif Has_Small_Clause (U_Ent) then
1491 Error_Msg_N ("small already given for &", Nam);
1493 elsif Small > Delta_Value (U_Ent) then
1495 ("small value must not be greater then delta value", Nam);
1498 Set_Small_Value (U_Ent, Small);
1499 Set_Small_Value (Implicit_Base, Small);
1500 Set_Has_Small_Clause (U_Ent);
1501 Set_Has_Small_Clause (Implicit_Base);
1502 Set_Has_Non_Standard_Rep (Implicit_Base);
1510 -- Storage_Pool attribute definition clause
1512 when Attribute_Storage_Pool => Storage_Pool : declare
1517 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1519 ("storage pool cannot be given for access-to-subprogram type",
1523 elsif Ekind (U_Ent) /= E_Access_Type
1524 and then Ekind (U_Ent) /= E_General_Access_Type
1527 ("storage pool can only be given for access types", Nam);
1530 elsif Is_Derived_Type (U_Ent) then
1532 ("storage pool cannot be given for a derived access type",
1535 elsif Has_Storage_Size_Clause (U_Ent) then
1536 Error_Msg_N ("storage size already given for &", Nam);
1539 elsif Present (Associated_Storage_Pool (U_Ent)) then
1540 Error_Msg_N ("storage pool already given for &", Nam);
1545 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1547 if not Denotes_Variable (Expr) then
1548 Error_Msg_N ("storage pool must be a variable", Expr);
1552 if Nkind (Expr) = N_Type_Conversion then
1553 T := Etype (Expression (Expr));
1558 -- The Stack_Bounded_Pool is used internally for implementing
1559 -- access types with a Storage_Size. Since it only work
1560 -- properly when used on one specific type, we need to check
1561 -- that it is not hijacked improperly:
1562 -- type T is access Integer;
1563 -- for T'Storage_Size use n;
1564 -- type Q is access Float;
1565 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1567 if RTE_Available (RE_Stack_Bounded_Pool)
1568 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1570 Error_Msg_N ("non-shareable internal Pool", Expr);
1574 -- If the argument is a name that is not an entity name, then
1575 -- we construct a renaming operation to define an entity of
1576 -- type storage pool.
1578 if not Is_Entity_Name (Expr)
1579 and then Is_Object_Reference (Expr)
1582 Make_Defining_Identifier (Loc,
1583 Chars => New_Internal_Name ('P'));
1586 Rnode : constant Node_Id :=
1587 Make_Object_Renaming_Declaration (Loc,
1588 Defining_Identifier => Pool,
1590 New_Occurrence_Of (Etype (Expr), Loc),
1594 Insert_Before (N, Rnode);
1596 Set_Associated_Storage_Pool (U_Ent, Pool);
1599 elsif Is_Entity_Name (Expr) then
1600 Pool := Entity (Expr);
1602 -- If pool is a renamed object, get original one. This can
1603 -- happen with an explicit renaming, and within instances.
1605 while Present (Renamed_Object (Pool))
1606 and then Is_Entity_Name (Renamed_Object (Pool))
1608 Pool := Entity (Renamed_Object (Pool));
1611 if Present (Renamed_Object (Pool))
1612 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1613 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1615 Pool := Entity (Expression (Renamed_Object (Pool)));
1618 Set_Associated_Storage_Pool (U_Ent, Pool);
1620 elsif Nkind (Expr) = N_Type_Conversion
1621 and then Is_Entity_Name (Expression (Expr))
1622 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1624 Pool := Entity (Expression (Expr));
1625 Set_Associated_Storage_Pool (U_Ent, Pool);
1628 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1637 -- Storage_Size attribute definition clause
1639 when Attribute_Storage_Size => Storage_Size : declare
1640 Btype : constant Entity_Id := Base_Type (U_Ent);
1644 if Is_Task_Type (U_Ent) then
1645 Check_Restriction (No_Obsolescent_Features, N);
1647 if Warn_On_Obsolescent_Feature then
1649 ("storage size clause for task is an " &
1650 "obsolescent feature (RM J.9)?", N);
1652 ("\use Storage_Size pragma instead?", N);
1658 if not Is_Access_Type (U_Ent)
1659 and then Ekind (U_Ent) /= E_Task_Type
1661 Error_Msg_N ("storage size cannot be given for &", Nam);
1663 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1665 ("storage size cannot be given for a derived access type",
1668 elsif Has_Storage_Size_Clause (Btype) then
1669 Error_Msg_N ("storage size already given for &", Nam);
1672 Analyze_And_Resolve (Expr, Any_Integer);
1674 if Is_Access_Type (U_Ent) then
1675 if Present (Associated_Storage_Pool (U_Ent)) then
1676 Error_Msg_N ("storage pool already given for &", Nam);
1680 if Compile_Time_Known_Value (Expr)
1681 and then Expr_Value (Expr) = 0
1683 Set_No_Pool_Assigned (Btype);
1686 else -- Is_Task_Type (U_Ent)
1687 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1689 if Present (Sprag) then
1690 Error_Msg_Sloc := Sloc (Sprag);
1692 ("Storage_Size already specified#", Nam);
1697 Set_Has_Storage_Size_Clause (Btype);
1705 when Attribute_Stream_Size => Stream_Size : declare
1706 Size : constant Uint := Static_Integer (Expr);
1709 if Ada_Version <= Ada_95 then
1710 Check_Restriction (No_Implementation_Attributes, N);
1713 if Has_Stream_Size_Clause (U_Ent) then
1714 Error_Msg_N ("Stream_Size already given for &", Nam);
1716 elsif Is_Elementary_Type (U_Ent) then
1717 if Size /= System_Storage_Unit
1719 Size /= System_Storage_Unit * 2
1721 Size /= System_Storage_Unit * 4
1723 Size /= System_Storage_Unit * 8
1725 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1727 ("stream size for elementary type must be a"
1728 & " power of 2 and at least ^", N);
1730 elsif RM_Size (U_Ent) > Size then
1731 Error_Msg_Uint_1 := RM_Size (U_Ent);
1733 ("stream size for elementary type must be a"
1734 & " power of 2 and at least ^", N);
1737 Set_Has_Stream_Size_Clause (U_Ent);
1740 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1748 -- Value_Size attribute definition clause
1750 when Attribute_Value_Size => Value_Size : declare
1751 Size : constant Uint := Static_Integer (Expr);
1755 if not Is_Type (U_Ent) then
1756 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1759 (Get_Attribute_Definition_Clause
1760 (U_Ent, Attribute_Value_Size))
1762 Error_Msg_N ("Value_Size already given for &", Nam);
1764 elsif Is_Array_Type (U_Ent)
1765 and then not Is_Constrained (U_Ent)
1768 ("Value_Size cannot be given for unconstrained array", Nam);
1771 if Is_Elementary_Type (U_Ent) then
1772 Check_Size (Expr, U_Ent, Size, Biased);
1773 Set_Has_Biased_Representation (U_Ent, Biased);
1775 if Biased and Warn_On_Biased_Representation then
1777 ("?value size clause forces biased representation", N);
1781 Set_RM_Size (U_Ent, Size);
1789 when Attribute_Write =>
1790 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1791 Set_Has_Specified_Stream_Write (Ent);
1793 -- All other attributes cannot be set
1797 ("attribute& cannot be set with definition clause", N);
1800 -- The test for the type being frozen must be performed after
1801 -- any expression the clause has been analyzed since the expression
1802 -- itself might cause freezing that makes the clause illegal.
1804 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1807 end Analyze_Attribute_Definition_Clause;
1809 ----------------------------
1810 -- Analyze_Code_Statement --
1811 ----------------------------
1813 procedure Analyze_Code_Statement (N : Node_Id) is
1814 HSS : constant Node_Id := Parent (N);
1815 SBody : constant Node_Id := Parent (HSS);
1816 Subp : constant Entity_Id := Current_Scope;
1823 -- Analyze and check we get right type, note that this implements the
1824 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1825 -- is the only way that Asm_Insn could possibly be visible.
1827 Analyze_And_Resolve (Expression (N));
1829 if Etype (Expression (N)) = Any_Type then
1831 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1832 Error_Msg_N ("incorrect type for code statement", N);
1836 Check_Code_Statement (N);
1838 -- Make sure we appear in the handled statement sequence of a
1839 -- subprogram (RM 13.8(3)).
1841 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
1842 or else Nkind (SBody) /= N_Subprogram_Body
1845 ("code statement can only appear in body of subprogram", N);
1849 -- Do remaining checks (RM 13.8(3)) if not already done
1851 if not Is_Machine_Code_Subprogram (Subp) then
1852 Set_Is_Machine_Code_Subprogram (Subp);
1854 -- No exception handlers allowed
1856 if Present (Exception_Handlers (HSS)) then
1858 ("exception handlers not permitted in machine code subprogram",
1859 First (Exception_Handlers (HSS)));
1862 -- No declarations other than use clauses and pragmas (we allow
1863 -- certain internally generated declarations as well).
1865 Decl := First (Declarations (SBody));
1866 while Present (Decl) loop
1867 DeclO := Original_Node (Decl);
1868 if Comes_From_Source (DeclO)
1869 and not Nkind_In (DeclO, N_Pragma,
1870 N_Use_Package_Clause,
1872 N_Implicit_Label_Declaration)
1875 ("this declaration not allowed in machine code subprogram",
1882 -- No statements other than code statements, pragmas, and labels.
1883 -- Again we allow certain internally generated statements.
1885 Stmt := First (Statements (HSS));
1886 while Present (Stmt) loop
1887 StmtO := Original_Node (Stmt);
1888 if Comes_From_Source (StmtO)
1889 and then not Nkind_In (StmtO, N_Pragma,
1894 ("this statement is not allowed in machine code subprogram",
1901 end Analyze_Code_Statement;
1903 -----------------------------------------------
1904 -- Analyze_Enumeration_Representation_Clause --
1905 -----------------------------------------------
1907 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
1908 Ident : constant Node_Id := Identifier (N);
1909 Aggr : constant Node_Id := Array_Aggregate (N);
1910 Enumtype : Entity_Id;
1916 Err : Boolean := False;
1918 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
1919 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
1924 if Ignore_Rep_Clauses then
1928 -- First some basic error checks
1931 Enumtype := Entity (Ident);
1933 if Enumtype = Any_Type
1934 or else Rep_Item_Too_Early (Enumtype, N)
1938 Enumtype := Underlying_Type (Enumtype);
1941 if not Is_Enumeration_Type (Enumtype) then
1943 ("enumeration type required, found}",
1944 Ident, First_Subtype (Enumtype));
1948 -- Ignore rep clause on generic actual type. This will already have
1949 -- been flagged on the template as an error, and this is the safest
1950 -- way to ensure we don't get a junk cascaded message in the instance.
1952 if Is_Generic_Actual_Type (Enumtype) then
1955 -- Type must be in current scope
1957 elsif Scope (Enumtype) /= Current_Scope then
1958 Error_Msg_N ("type must be declared in this scope", Ident);
1961 -- Type must be a first subtype
1963 elsif not Is_First_Subtype (Enumtype) then
1964 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
1967 -- Ignore duplicate rep clause
1969 elsif Has_Enumeration_Rep_Clause (Enumtype) then
1970 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
1973 -- Don't allow rep clause for standard [wide_[wide_]]character
1975 elsif Is_Standard_Character_Type (Enumtype) then
1976 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
1979 -- Check that the expression is a proper aggregate (no parentheses)
1981 elsif Paren_Count (Aggr) /= 0 then
1983 ("extra parentheses surrounding aggregate not allowed",
1987 -- All tests passed, so set rep clause in place
1990 Set_Has_Enumeration_Rep_Clause (Enumtype);
1991 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
1994 -- Now we process the aggregate. Note that we don't use the normal
1995 -- aggregate code for this purpose, because we don't want any of the
1996 -- normal expansion activities, and a number of special semantic
1997 -- rules apply (including the component type being any integer type)
1999 Elit := First_Literal (Enumtype);
2001 -- First the positional entries if any
2003 if Present (Expressions (Aggr)) then
2004 Expr := First (Expressions (Aggr));
2005 while Present (Expr) loop
2007 Error_Msg_N ("too many entries in aggregate", Expr);
2011 Val := Static_Integer (Expr);
2013 -- Err signals that we found some incorrect entries processing
2014 -- the list. The final checks for completeness and ordering are
2015 -- skipped in this case.
2017 if Val = No_Uint then
2019 elsif Val < Lo or else Hi < Val then
2020 Error_Msg_N ("value outside permitted range", Expr);
2024 Set_Enumeration_Rep (Elit, Val);
2025 Set_Enumeration_Rep_Expr (Elit, Expr);
2031 -- Now process the named entries if present
2033 if Present (Component_Associations (Aggr)) then
2034 Assoc := First (Component_Associations (Aggr));
2035 while Present (Assoc) loop
2036 Choice := First (Choices (Assoc));
2038 if Present (Next (Choice)) then
2040 ("multiple choice not allowed here", Next (Choice));
2044 if Nkind (Choice) = N_Others_Choice then
2045 Error_Msg_N ("others choice not allowed here", Choice);
2048 elsif Nkind (Choice) = N_Range then
2049 -- ??? should allow zero/one element range here
2050 Error_Msg_N ("range not allowed here", Choice);
2054 Analyze_And_Resolve (Choice, Enumtype);
2056 if Is_Entity_Name (Choice)
2057 and then Is_Type (Entity (Choice))
2059 Error_Msg_N ("subtype name not allowed here", Choice);
2061 -- ??? should allow static subtype with zero/one entry
2063 elsif Etype (Choice) = Base_Type (Enumtype) then
2064 if not Is_Static_Expression (Choice) then
2065 Flag_Non_Static_Expr
2066 ("non-static expression used for choice!", Choice);
2070 Elit := Expr_Value_E (Choice);
2072 if Present (Enumeration_Rep_Expr (Elit)) then
2073 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2075 ("representation for& previously given#",
2080 Set_Enumeration_Rep_Expr (Elit, Choice);
2082 Expr := Expression (Assoc);
2083 Val := Static_Integer (Expr);
2085 if Val = No_Uint then
2088 elsif Val < Lo or else Hi < Val then
2089 Error_Msg_N ("value outside permitted range", Expr);
2093 Set_Enumeration_Rep (Elit, Val);
2102 -- Aggregate is fully processed. Now we check that a full set of
2103 -- representations was given, and that they are in range and in order.
2104 -- These checks are only done if no other errors occurred.
2110 Elit := First_Literal (Enumtype);
2111 while Present (Elit) loop
2112 if No (Enumeration_Rep_Expr (Elit)) then
2113 Error_Msg_NE ("missing representation for&!", N, Elit);
2116 Val := Enumeration_Rep (Elit);
2118 if Min = No_Uint then
2122 if Val /= No_Uint then
2123 if Max /= No_Uint and then Val <= Max then
2125 ("enumeration value for& not ordered!",
2126 Enumeration_Rep_Expr (Elit), Elit);
2132 -- If there is at least one literal whose representation
2133 -- is not equal to the Pos value, then note that this
2134 -- enumeration type has a non-standard representation.
2136 if Val /= Enumeration_Pos (Elit) then
2137 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2144 -- Now set proper size information
2147 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2150 if Has_Size_Clause (Enumtype) then
2151 if Esize (Enumtype) >= Minsize then
2156 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2158 if Esize (Enumtype) < Minsize then
2159 Error_Msg_N ("previously given size is too small", N);
2162 Set_Has_Biased_Representation (Enumtype);
2167 Set_RM_Size (Enumtype, Minsize);
2168 Set_Enum_Esize (Enumtype);
2171 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2172 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2173 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2177 -- We repeat the too late test in case it froze itself!
2179 if Rep_Item_Too_Late (Enumtype, N) then
2182 end Analyze_Enumeration_Representation_Clause;
2184 ----------------------------
2185 -- Analyze_Free_Statement --
2186 ----------------------------
2188 procedure Analyze_Free_Statement (N : Node_Id) is
2190 Analyze (Expression (N));
2191 end Analyze_Free_Statement;
2193 ------------------------------------------
2194 -- Analyze_Record_Representation_Clause --
2195 ------------------------------------------
2197 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2198 Loc : constant Source_Ptr := Sloc (N);
2199 Ident : constant Node_Id := Identifier (N);
2200 Rectype : Entity_Id;
2206 Hbit : Uint := Uint_0;
2211 Max_Bit_So_Far : Uint;
2212 -- Records the maximum bit position so far. If all field positions
2213 -- are monotonically increasing, then we can skip the circuit for
2214 -- checking for overlap, since no overlap is possible.
2216 Overlap_Check_Required : Boolean;
2217 -- Used to keep track of whether or not an overlap check is required
2219 Ccount : Natural := 0;
2220 -- Number of component clauses in record rep clause
2222 CR_Pragma : Node_Id := Empty;
2223 -- Points to N_Pragma node if Complete_Representation pragma present
2226 if Ignore_Rep_Clauses then
2231 Rectype := Entity (Ident);
2233 if Rectype = Any_Type
2234 or else Rep_Item_Too_Early (Rectype, N)
2238 Rectype := Underlying_Type (Rectype);
2241 -- First some basic error checks
2243 if not Is_Record_Type (Rectype) then
2245 ("record type required, found}", Ident, First_Subtype (Rectype));
2248 elsif Is_Unchecked_Union (Rectype) then
2250 ("record rep clause not allowed for Unchecked_Union", N);
2252 elsif Scope (Rectype) /= Current_Scope then
2253 Error_Msg_N ("type must be declared in this scope", N);
2256 elsif not Is_First_Subtype (Rectype) then
2257 Error_Msg_N ("cannot give record rep clause for subtype", N);
2260 elsif Has_Record_Rep_Clause (Rectype) then
2261 Error_Msg_N ("duplicate record rep clause ignored", N);
2264 elsif Rep_Item_Too_Late (Rectype, N) then
2268 if Present (Mod_Clause (N)) then
2270 Loc : constant Source_Ptr := Sloc (N);
2271 M : constant Node_Id := Mod_Clause (N);
2272 P : constant List_Id := Pragmas_Before (M);
2276 pragma Warnings (Off, Mod_Val);
2279 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2281 if Warn_On_Obsolescent_Feature then
2283 ("mod clause is an obsolescent feature (RM J.8)?", N);
2285 ("\use alignment attribute definition clause instead?", N);
2292 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2293 -- the Mod clause into an alignment clause anyway, so that the
2294 -- back-end can compute and back-annotate properly the size and
2295 -- alignment of types that may include this record.
2297 -- This seems dubious, this destroys the source tree in a manner
2298 -- not detectable by ASIS ???
2300 if Operating_Mode = Check_Semantics
2304 Make_Attribute_Definition_Clause (Loc,
2305 Name => New_Reference_To (Base_Type (Rectype), Loc),
2306 Chars => Name_Alignment,
2307 Expression => Relocate_Node (Expression (M)));
2309 Set_From_At_Mod (AtM_Nod);
2310 Insert_After (N, AtM_Nod);
2311 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2312 Set_Mod_Clause (N, Empty);
2315 -- Get the alignment value to perform error checking
2317 Mod_Val := Get_Alignment_Value (Expression (M));
2323 -- For untagged types, clear any existing component clauses for the
2324 -- type. If the type is derived, this is what allows us to override
2325 -- a rep clause for the parent. For type extensions, the representation
2326 -- of the inherited components is inherited, so we want to keep previous
2327 -- component clauses for completeness.
2329 if not Is_Tagged_Type (Rectype) then
2330 Comp := First_Component_Or_Discriminant (Rectype);
2331 while Present (Comp) loop
2332 Set_Component_Clause (Comp, Empty);
2333 Next_Component_Or_Discriminant (Comp);
2337 -- All done if no component clauses
2339 CC := First (Component_Clauses (N));
2345 -- If a tag is present, then create a component clause that places it
2346 -- at the start of the record (otherwise gigi may place it after other
2347 -- fields that have rep clauses).
2349 Fent := First_Entity (Rectype);
2351 if Nkind (Fent) = N_Defining_Identifier
2352 and then Chars (Fent) = Name_uTag
2354 Set_Component_Bit_Offset (Fent, Uint_0);
2355 Set_Normalized_Position (Fent, Uint_0);
2356 Set_Normalized_First_Bit (Fent, Uint_0);
2357 Set_Normalized_Position_Max (Fent, Uint_0);
2358 Init_Esize (Fent, System_Address_Size);
2360 Set_Component_Clause (Fent,
2361 Make_Component_Clause (Loc,
2363 Make_Identifier (Loc,
2364 Chars => Name_uTag),
2367 Make_Integer_Literal (Loc,
2371 Make_Integer_Literal (Loc,
2375 Make_Integer_Literal (Loc,
2376 UI_From_Int (System_Address_Size))));
2378 Ccount := Ccount + 1;
2381 -- A representation like this applies to the base type
2383 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2384 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2385 Set_Has_Specified_Layout (Base_Type (Rectype));
2387 Max_Bit_So_Far := Uint_Minus_1;
2388 Overlap_Check_Required := False;
2390 -- Process the component clauses
2392 while Present (CC) loop
2396 if Nkind (CC) = N_Pragma then
2399 -- The only pragma of interest is Complete_Representation
2401 if Pragma_Name (CC) = Name_Complete_Representation then
2405 -- Processing for real component clause
2408 Ccount := Ccount + 1;
2409 Posit := Static_Integer (Position (CC));
2410 Fbit := Static_Integer (First_Bit (CC));
2411 Lbit := Static_Integer (Last_Bit (CC));
2414 and then Fbit /= No_Uint
2415 and then Lbit /= No_Uint
2419 ("position cannot be negative", Position (CC));
2423 ("first bit cannot be negative", First_Bit (CC));
2425 -- The Last_Bit specified in a component clause must not be
2426 -- less than the First_Bit minus one (RM-13.5.1(10)).
2428 elsif Lbit < Fbit - 1 then
2430 ("last bit cannot be less than first bit minus one",
2433 -- Values look OK, so find the corresponding record component
2434 -- Even though the syntax allows an attribute reference for
2435 -- implementation-defined components, GNAT does not allow the
2436 -- tag to get an explicit position.
2438 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2439 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2440 Error_Msg_N ("position of tag cannot be specified", CC);
2442 Error_Msg_N ("illegal component name", CC);
2446 Comp := First_Entity (Rectype);
2447 while Present (Comp) loop
2448 exit when Chars (Comp) = Chars (Component_Name (CC));
2454 -- Maybe component of base type that is absent from
2455 -- statically constrained first subtype.
2457 Comp := First_Entity (Base_Type (Rectype));
2458 while Present (Comp) loop
2459 exit when Chars (Comp) = Chars (Component_Name (CC));
2466 ("component clause is for non-existent field", CC);
2468 elsif Present (Component_Clause (Comp)) then
2470 -- Diagnose duplicate rep clause, or check consistency
2471 -- if this is an inherited component. In a double fault,
2472 -- there may be a duplicate inconsistent clause for an
2473 -- inherited component.
2475 if Scope (Original_Record_Component (Comp)) = Rectype
2476 or else Parent (Component_Clause (Comp)) = N
2478 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2479 Error_Msg_N ("component clause previously given#", CC);
2483 Rep1 : constant Node_Id := Component_Clause (Comp);
2485 if Intval (Position (Rep1)) /=
2486 Intval (Position (CC))
2487 or else Intval (First_Bit (Rep1)) /=
2488 Intval (First_Bit (CC))
2489 or else Intval (Last_Bit (Rep1)) /=
2490 Intval (Last_Bit (CC))
2492 Error_Msg_N ("component clause inconsistent "
2493 & "with representation of ancestor", CC);
2494 elsif Warn_On_Redundant_Constructs then
2495 Error_Msg_N ("?redundant component clause "
2496 & "for inherited component!", CC);
2502 -- Make reference for field in record rep clause and set
2503 -- appropriate entity field in the field identifier.
2506 (Comp, Component_Name (CC), Set_Ref => False);
2507 Set_Entity (Component_Name (CC), Comp);
2509 -- Update Fbit and Lbit to the actual bit number
2511 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2512 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2514 if Fbit <= Max_Bit_So_Far then
2515 Overlap_Check_Required := True;
2517 Max_Bit_So_Far := Lbit;
2520 if Has_Size_Clause (Rectype)
2521 and then Esize (Rectype) <= Lbit
2524 ("bit number out of range of specified size",
2527 Set_Component_Clause (Comp, CC);
2528 Set_Component_Bit_Offset (Comp, Fbit);
2529 Set_Esize (Comp, 1 + (Lbit - Fbit));
2530 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2531 Set_Normalized_Position (Comp, Fbit / SSU);
2533 Set_Normalized_Position_Max
2534 (Fent, Normalized_Position (Fent));
2536 if Is_Tagged_Type (Rectype)
2537 and then Fbit < System_Address_Size
2540 ("component overlaps tag field of&",
2544 -- This information is also set in the corresponding
2545 -- component of the base type, found by accessing the
2546 -- Original_Record_Component link if it is present.
2548 Ocomp := Original_Record_Component (Comp);
2555 (Component_Name (CC),
2560 Set_Has_Biased_Representation (Comp, Biased);
2562 if Biased and Warn_On_Biased_Representation then
2564 ("?component clause forces biased "
2565 & "representation", CC);
2568 if Present (Ocomp) then
2569 Set_Component_Clause (Ocomp, CC);
2570 Set_Component_Bit_Offset (Ocomp, Fbit);
2571 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2572 Set_Normalized_Position (Ocomp, Fbit / SSU);
2573 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2575 Set_Normalized_Position_Max
2576 (Ocomp, Normalized_Position (Ocomp));
2578 Set_Has_Biased_Representation
2579 (Ocomp, Has_Biased_Representation (Comp));
2582 if Esize (Comp) < 0 then
2583 Error_Msg_N ("component size is negative", CC);
2594 -- Now that we have processed all the component clauses, check for
2595 -- overlap. We have to leave this till last, since the components can
2596 -- appear in any arbitrary order in the representation clause.
2598 -- We do not need this check if all specified ranges were monotonic,
2599 -- as recorded by Overlap_Check_Required being False at this stage.
2601 -- This first section checks if there are any overlapping entries at
2602 -- all. It does this by sorting all entries and then seeing if there are
2603 -- any overlaps. If there are none, then that is decisive, but if there
2604 -- are overlaps, they may still be OK (they may result from fields in
2605 -- different variants).
2607 if Overlap_Check_Required then
2608 Overlap_Check1 : declare
2610 OC_Fbit : array (0 .. Ccount) of Uint;
2611 -- First-bit values for component clauses, the value is the offset
2612 -- of the first bit of the field from start of record. The zero
2613 -- entry is for use in sorting.
2615 OC_Lbit : array (0 .. Ccount) of Uint;
2616 -- Last-bit values for component clauses, the value is the offset
2617 -- of the last bit of the field from start of record. The zero
2618 -- entry is for use in sorting.
2620 OC_Count : Natural := 0;
2621 -- Count of entries in OC_Fbit and OC_Lbit
2623 function OC_Lt (Op1, Op2 : Natural) return Boolean;
2624 -- Compare routine for Sort
2626 procedure OC_Move (From : Natural; To : Natural);
2627 -- Move routine for Sort
2629 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
2631 function OC_Lt (Op1, Op2 : Natural) return Boolean is
2633 return OC_Fbit (Op1) < OC_Fbit (Op2);
2636 procedure OC_Move (From : Natural; To : Natural) is
2638 OC_Fbit (To) := OC_Fbit (From);
2639 OC_Lbit (To) := OC_Lbit (From);
2643 CC := First (Component_Clauses (N));
2644 while Present (CC) loop
2645 if Nkind (CC) /= N_Pragma then
2646 Posit := Static_Integer (Position (CC));
2647 Fbit := Static_Integer (First_Bit (CC));
2648 Lbit := Static_Integer (Last_Bit (CC));
2651 and then Fbit /= No_Uint
2652 and then Lbit /= No_Uint
2654 OC_Count := OC_Count + 1;
2655 Posit := Posit * SSU;
2656 OC_Fbit (OC_Count) := Fbit + Posit;
2657 OC_Lbit (OC_Count) := Lbit + Posit;
2664 Sorting.Sort (OC_Count);
2666 Overlap_Check_Required := False;
2667 for J in 1 .. OC_Count - 1 loop
2668 if OC_Lbit (J) >= OC_Fbit (J + 1) then
2669 Overlap_Check_Required := True;
2676 -- If Overlap_Check_Required is still True, then we have to do the full
2677 -- scale overlap check, since we have at least two fields that do
2678 -- overlap, and we need to know if that is OK since they are in
2679 -- different variant, or whether we have a definite problem.
2681 if Overlap_Check_Required then
2682 Overlap_Check2 : declare
2683 C1_Ent, C2_Ent : Entity_Id;
2684 -- Entities of components being checked for overlap
2687 -- Component_List node whose Component_Items are being checked
2690 -- Component declaration for component being checked
2693 C1_Ent := First_Entity (Base_Type (Rectype));
2695 -- Loop through all components in record. For each component check
2696 -- for overlap with any of the preceding elements on the component
2697 -- list containing the component and also, if the component is in
2698 -- a variant, check against components outside the case structure.
2699 -- This latter test is repeated recursively up the variant tree.
2701 Main_Component_Loop : while Present (C1_Ent) loop
2702 if Ekind (C1_Ent) /= E_Component
2703 and then Ekind (C1_Ent) /= E_Discriminant
2705 goto Continue_Main_Component_Loop;
2708 -- Skip overlap check if entity has no declaration node. This
2709 -- happens with discriminants in constrained derived types.
2710 -- Probably we are missing some checks as a result, but that
2711 -- does not seem terribly serious ???
2713 if No (Declaration_Node (C1_Ent)) then
2714 goto Continue_Main_Component_Loop;
2717 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
2719 -- Loop through component lists that need checking. Check the
2720 -- current component list and all lists in variants above us.
2722 Component_List_Loop : loop
2724 -- If derived type definition, go to full declaration
2725 -- If at outer level, check discriminants if there are any.
2727 if Nkind (Clist) = N_Derived_Type_Definition then
2728 Clist := Parent (Clist);
2731 -- Outer level of record definition, check discriminants
2733 if Nkind_In (Clist, N_Full_Type_Declaration,
2734 N_Private_Type_Declaration)
2736 if Has_Discriminants (Defining_Identifier (Clist)) then
2738 First_Discriminant (Defining_Identifier (Clist));
2740 while Present (C2_Ent) loop
2741 exit when C1_Ent = C2_Ent;
2742 Check_Component_Overlap (C1_Ent, C2_Ent);
2743 Next_Discriminant (C2_Ent);
2747 -- Record extension case
2749 elsif Nkind (Clist) = N_Derived_Type_Definition then
2752 -- Otherwise check one component list
2755 Citem := First (Component_Items (Clist));
2757 while Present (Citem) loop
2758 if Nkind (Citem) = N_Component_Declaration then
2759 C2_Ent := Defining_Identifier (Citem);
2760 exit when C1_Ent = C2_Ent;
2761 Check_Component_Overlap (C1_Ent, C2_Ent);
2768 -- Check for variants above us (the parent of the Clist can
2769 -- be a variant, in which case its parent is a variant part,
2770 -- and the parent of the variant part is a component list
2771 -- whose components must all be checked against the current
2772 -- component for overlap).
2774 if Nkind (Parent (Clist)) = N_Variant then
2775 Clist := Parent (Parent (Parent (Clist)));
2777 -- Check for possible discriminant part in record, this is
2778 -- treated essentially as another level in the recursion.
2779 -- For this case the parent of the component list is the
2780 -- record definition, and its parent is the full type
2781 -- declaration containing the discriminant specifications.
2783 elsif Nkind (Parent (Clist)) = N_Record_Definition then
2784 Clist := Parent (Parent ((Clist)));
2786 -- If neither of these two cases, we are at the top of
2790 exit Component_List_Loop;
2792 end loop Component_List_Loop;
2794 <<Continue_Main_Component_Loop>>
2795 Next_Entity (C1_Ent);
2797 end loop Main_Component_Loop;
2801 -- For records that have component clauses for all components, and whose
2802 -- size is less than or equal to 32, we need to know the size in the
2803 -- front end to activate possible packed array processing where the
2804 -- component type is a record.
2806 -- At this stage Hbit + 1 represents the first unused bit from all the
2807 -- component clauses processed, so if the component clauses are
2808 -- complete, then this is the length of the record.
2810 -- For records longer than System.Storage_Unit, and for those where not
2811 -- all components have component clauses, the back end determines the
2812 -- length (it may for example be appropriate to round up the size
2813 -- to some convenient boundary, based on alignment considerations, etc).
2815 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
2817 -- Nothing to do if at least one component has no component clause
2819 Comp := First_Component_Or_Discriminant (Rectype);
2820 while Present (Comp) loop
2821 exit when No (Component_Clause (Comp));
2822 Next_Component_Or_Discriminant (Comp);
2825 -- If we fall out of loop, all components have component clauses
2826 -- and so we can set the size to the maximum value.
2829 Set_RM_Size (Rectype, Hbit + 1);
2833 -- Check missing components if Complete_Representation pragma appeared
2835 if Present (CR_Pragma) then
2836 Comp := First_Component_Or_Discriminant (Rectype);
2837 while Present (Comp) loop
2838 if No (Component_Clause (Comp)) then
2840 ("missing component clause for &", CR_Pragma, Comp);
2843 Next_Component_Or_Discriminant (Comp);
2846 -- If no Complete_Representation pragma, warn if missing components
2848 elsif Warn_On_Unrepped_Components then
2850 Num_Repped_Components : Nat := 0;
2851 Num_Unrepped_Components : Nat := 0;
2854 -- First count number of repped and unrepped components
2856 Comp := First_Component_Or_Discriminant (Rectype);
2857 while Present (Comp) loop
2858 if Present (Component_Clause (Comp)) then
2859 Num_Repped_Components := Num_Repped_Components + 1;
2861 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2864 Next_Component_Or_Discriminant (Comp);
2867 -- We are only interested in the case where there is at least one
2868 -- unrepped component, and at least half the components have rep
2869 -- clauses. We figure that if less than half have them, then the
2870 -- partial rep clause is really intentional. If the component
2871 -- type has no underlying type set at this point (as for a generic
2872 -- formal type), we don't know enough to give a warning on the
2875 if Num_Unrepped_Components > 0
2876 and then Num_Unrepped_Components < Num_Repped_Components
2878 Comp := First_Component_Or_Discriminant (Rectype);
2879 while Present (Comp) loop
2880 if No (Component_Clause (Comp))
2881 and then Comes_From_Source (Comp)
2882 and then Present (Underlying_Type (Etype (Comp)))
2883 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2884 or else Size_Known_At_Compile_Time
2885 (Underlying_Type (Etype (Comp))))
2886 and then not Has_Warnings_Off (Rectype)
2888 Error_Msg_Sloc := Sloc (Comp);
2890 ("?no component clause given for & declared #",
2894 Next_Component_Or_Discriminant (Comp);
2899 end Analyze_Record_Representation_Clause;
2901 -----------------------------
2902 -- Check_Component_Overlap --
2903 -----------------------------
2905 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
2907 if Present (Component_Clause (C1_Ent))
2908 and then Present (Component_Clause (C2_Ent))
2910 -- Exclude odd case where we have two tag fields in the same record,
2911 -- both at location zero. This seems a bit strange, but it seems to
2912 -- happen in some circumstances ???
2914 if Chars (C1_Ent) = Name_uTag
2915 and then Chars (C2_Ent) = Name_uTag
2920 -- Here we check if the two fields overlap
2923 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
2924 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
2925 E1 : constant Uint := S1 + Esize (C1_Ent);
2926 E2 : constant Uint := S2 + Esize (C2_Ent);
2929 if E2 <= S1 or else E1 <= S2 then
2933 Component_Name (Component_Clause (C2_Ent));
2934 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
2936 Component_Name (Component_Clause (C1_Ent));
2938 ("component& overlaps & #",
2939 Component_Name (Component_Clause (C1_Ent)));
2943 end Check_Component_Overlap;
2945 -----------------------------------
2946 -- Check_Constant_Address_Clause --
2947 -----------------------------------
2949 procedure Check_Constant_Address_Clause
2953 procedure Check_At_Constant_Address (Nod : Node_Id);
2954 -- Checks that the given node N represents a name whose 'Address is
2955 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2956 -- address value is the same at the point of declaration of U_Ent and at
2957 -- the time of elaboration of the address clause.
2959 procedure Check_Expr_Constants (Nod : Node_Id);
2960 -- Checks that Nod meets the requirements for a constant address clause
2961 -- in the sense of the enclosing procedure.
2963 procedure Check_List_Constants (Lst : List_Id);
2964 -- Check that all elements of list Lst meet the requirements for a
2965 -- constant address clause in the sense of the enclosing procedure.
2967 -------------------------------
2968 -- Check_At_Constant_Address --
2969 -------------------------------
2971 procedure Check_At_Constant_Address (Nod : Node_Id) is
2973 if Is_Entity_Name (Nod) then
2974 if Present (Address_Clause (Entity ((Nod)))) then
2976 ("invalid address clause for initialized object &!",
2979 ("address for& cannot" &
2980 " depend on another address clause! (RM 13.1(22))!",
2983 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2984 and then Sloc (U_Ent) < Sloc (Entity (Nod))
2987 ("invalid address clause for initialized object &!",
2989 Error_Msg_Node_2 := U_Ent;
2991 ("\& must be defined before & (RM 13.1(22))!",
2995 elsif Nkind (Nod) = N_Selected_Component then
2997 T : constant Entity_Id := Etype (Prefix (Nod));
3000 if (Is_Record_Type (T)
3001 and then Has_Discriminants (T))
3004 and then Is_Record_Type (Designated_Type (T))
3005 and then Has_Discriminants (Designated_Type (T)))
3008 ("invalid address clause for initialized object &!",
3011 ("\address cannot depend on component" &
3012 " of discriminated record (RM 13.1(22))!",
3015 Check_At_Constant_Address (Prefix (Nod));
3019 elsif Nkind (Nod) = N_Indexed_Component then
3020 Check_At_Constant_Address (Prefix (Nod));
3021 Check_List_Constants (Expressions (Nod));
3024 Check_Expr_Constants (Nod);
3026 end Check_At_Constant_Address;
3028 --------------------------
3029 -- Check_Expr_Constants --
3030 --------------------------
3032 procedure Check_Expr_Constants (Nod : Node_Id) is
3033 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
3034 Ent : Entity_Id := Empty;
3037 if Nkind (Nod) in N_Has_Etype
3038 and then Etype (Nod) = Any_Type
3044 when N_Empty | N_Error =>
3047 when N_Identifier | N_Expanded_Name =>
3048 Ent := Entity (Nod);
3050 -- We need to look at the original node if it is different
3051 -- from the node, since we may have rewritten things and
3052 -- substituted an identifier representing the rewrite.
3054 if Original_Node (Nod) /= Nod then
3055 Check_Expr_Constants (Original_Node (Nod));
3057 -- If the node is an object declaration without initial
3058 -- value, some code has been expanded, and the expression
3059 -- is not constant, even if the constituents might be
3060 -- acceptable, as in A'Address + offset.
3062 if Ekind (Ent) = E_Variable
3064 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3066 No (Expression (Declaration_Node (Ent)))
3069 ("invalid address clause for initialized object &!",
3072 -- If entity is constant, it may be the result of expanding
3073 -- a check. We must verify that its declaration appears
3074 -- before the object in question, else we also reject the
3077 elsif Ekind (Ent) = E_Constant
3078 and then In_Same_Source_Unit (Ent, U_Ent)
3079 and then Sloc (Ent) > Loc_U_Ent
3082 ("invalid address clause for initialized object &!",
3089 -- Otherwise look at the identifier and see if it is OK
3091 if Ekind (Ent) = E_Named_Integer
3093 Ekind (Ent) = E_Named_Real
3100 Ekind (Ent) = E_Constant
3102 Ekind (Ent) = E_In_Parameter
3104 -- This is the case where we must have Ent defined before
3105 -- U_Ent. Clearly if they are in different units this
3106 -- requirement is met since the unit containing Ent is
3107 -- already processed.
3109 if not In_Same_Source_Unit (Ent, U_Ent) then
3112 -- Otherwise location of Ent must be before the location
3113 -- of U_Ent, that's what prior defined means.
3115 elsif Sloc (Ent) < Loc_U_Ent then
3120 ("invalid address clause for initialized object &!",
3122 Error_Msg_Node_2 := U_Ent;
3124 ("\& must be defined before & (RM 13.1(22))!",
3128 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3129 Check_Expr_Constants (Original_Node (Nod));
3133 ("invalid address clause for initialized object &!",
3136 if Comes_From_Source (Ent) then
3138 ("\reference to variable& not allowed"
3139 & " (RM 13.1(22))!", Nod, Ent);
3142 ("non-static expression not allowed"
3143 & " (RM 13.1(22))!", Nod);
3147 when N_Integer_Literal =>
3149 -- If this is a rewritten unchecked conversion, in a system
3150 -- where Address is an integer type, always use the base type
3151 -- for a literal value. This is user-friendly and prevents
3152 -- order-of-elaboration issues with instances of unchecked
3155 if Nkind (Original_Node (Nod)) = N_Function_Call then
3156 Set_Etype (Nod, Base_Type (Etype (Nod)));
3159 when N_Real_Literal |
3161 N_Character_Literal =>
3165 Check_Expr_Constants (Low_Bound (Nod));
3166 Check_Expr_Constants (High_Bound (Nod));
3168 when N_Explicit_Dereference =>
3169 Check_Expr_Constants (Prefix (Nod));
3171 when N_Indexed_Component =>
3172 Check_Expr_Constants (Prefix (Nod));
3173 Check_List_Constants (Expressions (Nod));
3176 Check_Expr_Constants (Prefix (Nod));
3177 Check_Expr_Constants (Discrete_Range (Nod));
3179 when N_Selected_Component =>
3180 Check_Expr_Constants (Prefix (Nod));
3182 when N_Attribute_Reference =>
3183 if Attribute_Name (Nod) = Name_Address
3185 Attribute_Name (Nod) = Name_Access
3187 Attribute_Name (Nod) = Name_Unchecked_Access
3189 Attribute_Name (Nod) = Name_Unrestricted_Access
3191 Check_At_Constant_Address (Prefix (Nod));
3194 Check_Expr_Constants (Prefix (Nod));
3195 Check_List_Constants (Expressions (Nod));
3199 Check_List_Constants (Component_Associations (Nod));
3200 Check_List_Constants (Expressions (Nod));
3202 when N_Component_Association =>
3203 Check_Expr_Constants (Expression (Nod));
3205 when N_Extension_Aggregate =>
3206 Check_Expr_Constants (Ancestor_Part (Nod));
3207 Check_List_Constants (Component_Associations (Nod));
3208 Check_List_Constants (Expressions (Nod));
3213 when N_Binary_Op | N_And_Then | N_Or_Else | N_Membership_Test =>
3214 Check_Expr_Constants (Left_Opnd (Nod));
3215 Check_Expr_Constants (Right_Opnd (Nod));
3218 Check_Expr_Constants (Right_Opnd (Nod));
3220 when N_Type_Conversion |
3221 N_Qualified_Expression |
3223 Check_Expr_Constants (Expression (Nod));
3225 when N_Unchecked_Type_Conversion =>
3226 Check_Expr_Constants (Expression (Nod));
3228 -- If this is a rewritten unchecked conversion, subtypes in
3229 -- this node are those created within the instance. To avoid
3230 -- order of elaboration issues, replace them with their base
3231 -- types. Note that address clauses can cause order of
3232 -- elaboration problems because they are elaborated by the
3233 -- back-end at the point of definition, and may mention
3234 -- entities declared in between (as long as everything is
3235 -- static). It is user-friendly to allow unchecked conversions
3238 if Nkind (Original_Node (Nod)) = N_Function_Call then
3239 Set_Etype (Expression (Nod),
3240 Base_Type (Etype (Expression (Nod))));
3241 Set_Etype (Nod, Base_Type (Etype (Nod)));
3244 when N_Function_Call =>
3245 if not Is_Pure (Entity (Name (Nod))) then
3247 ("invalid address clause for initialized object &!",
3251 ("\function & is not pure (RM 13.1(22))!",
3252 Nod, Entity (Name (Nod)));
3255 Check_List_Constants (Parameter_Associations (Nod));
3258 when N_Parameter_Association =>
3259 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3263 ("invalid address clause for initialized object &!",
3266 ("\must be constant defined before& (RM 13.1(22))!",
3269 end Check_Expr_Constants;
3271 --------------------------
3272 -- Check_List_Constants --
3273 --------------------------
3275 procedure Check_List_Constants (Lst : List_Id) is
3279 if Present (Lst) then
3280 Nod1 := First (Lst);
3281 while Present (Nod1) loop
3282 Check_Expr_Constants (Nod1);
3286 end Check_List_Constants;
3288 -- Start of processing for Check_Constant_Address_Clause
3291 Check_Expr_Constants (Expr);
3292 end Check_Constant_Address_Clause;
3298 procedure Check_Size
3302 Biased : out Boolean)
3304 UT : constant Entity_Id := Underlying_Type (T);
3310 -- Dismiss cases for generic types or types with previous errors
3313 or else UT = Any_Type
3314 or else Is_Generic_Type (UT)
3315 or else Is_Generic_Type (Root_Type (UT))
3319 -- Check case of bit packed array
3321 elsif Is_Array_Type (UT)
3322 and then Known_Static_Component_Size (UT)
3323 and then Is_Bit_Packed_Array (UT)
3331 Asiz := Component_Size (UT);
3332 Indx := First_Index (UT);
3334 Ityp := Etype (Indx);
3336 -- If non-static bound, then we are not in the business of
3337 -- trying to check the length, and indeed an error will be
3338 -- issued elsewhere, since sizes of non-static array types
3339 -- cannot be set implicitly or explicitly.
3341 if not Is_Static_Subtype (Ityp) then
3345 -- Otherwise accumulate next dimension
3347 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
3348 Expr_Value (Type_Low_Bound (Ityp)) +
3352 exit when No (Indx);
3358 Error_Msg_Uint_1 := Asiz;
3360 ("size for& too small, minimum allowed is ^", N, T);
3361 Set_Esize (T, Asiz);
3362 Set_RM_Size (T, Asiz);
3366 -- All other composite types are ignored
3368 elsif Is_Composite_Type (UT) then
3371 -- For fixed-point types, don't check minimum if type is not frozen,
3372 -- since we don't know all the characteristics of the type that can
3373 -- affect the size (e.g. a specified small) till freeze time.
3375 elsif Is_Fixed_Point_Type (UT)
3376 and then not Is_Frozen (UT)
3380 -- Cases for which a minimum check is required
3383 -- Ignore if specified size is correct for the type
3385 if Known_Esize (UT) and then Siz = Esize (UT) then
3389 -- Otherwise get minimum size
3391 M := UI_From_Int (Minimum_Size (UT));
3395 -- Size is less than minimum size, but one possibility remains
3396 -- that we can manage with the new size if we bias the type.
3398 M := UI_From_Int (Minimum_Size (UT, Biased => True));
3401 Error_Msg_Uint_1 := M;
3403 ("size for& too small, minimum allowed is ^", N, T);
3413 -------------------------
3414 -- Get_Alignment_Value --
3415 -------------------------
3417 function Get_Alignment_Value (Expr : Node_Id) return Uint is
3418 Align : constant Uint := Static_Integer (Expr);
3421 if Align = No_Uint then
3424 elsif Align <= 0 then
3425 Error_Msg_N ("alignment value must be positive", Expr);
3429 for J in Int range 0 .. 64 loop
3431 M : constant Uint := Uint_2 ** J;
3434 exit when M = Align;
3438 ("alignment value must be power of 2", Expr);
3446 end Get_Alignment_Value;
3452 procedure Initialize is
3454 Unchecked_Conversions.Init;
3457 -------------------------
3458 -- Is_Operational_Item --
3459 -------------------------
3461 function Is_Operational_Item (N : Node_Id) return Boolean is
3463 if Nkind (N) /= N_Attribute_Definition_Clause then
3467 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
3469 return Id = Attribute_Input
3470 or else Id = Attribute_Output
3471 or else Id = Attribute_Read
3472 or else Id = Attribute_Write
3473 or else Id = Attribute_External_Tag;
3476 end Is_Operational_Item;
3482 function Minimum_Size
3484 Biased : Boolean := False) return Nat
3486 Lo : Uint := No_Uint;
3487 Hi : Uint := No_Uint;
3488 LoR : Ureal := No_Ureal;
3489 HiR : Ureal := No_Ureal;
3490 LoSet : Boolean := False;
3491 HiSet : Boolean := False;
3495 R_Typ : constant Entity_Id := Root_Type (T);
3498 -- If bad type, return 0
3500 if T = Any_Type then
3503 -- For generic types, just return zero. There cannot be any legitimate
3504 -- need to know such a size, but this routine may be called with a
3505 -- generic type as part of normal processing.
3507 elsif Is_Generic_Type (R_Typ)
3508 or else R_Typ = Any_Type
3512 -- Access types. Normally an access type cannot have a size smaller
3513 -- than the size of System.Address. The exception is on VMS, where
3514 -- we have short and long addresses, and it is possible for an access
3515 -- type to have a short address size (and thus be less than the size
3516 -- of System.Address itself). We simply skip the check for VMS, and
3517 -- leave it to the back end to do the check.
3519 elsif Is_Access_Type (T) then
3520 if OpenVMS_On_Target then
3523 return System_Address_Size;
3526 -- Floating-point types
3528 elsif Is_Floating_Point_Type (T) then
3529 return UI_To_Int (Esize (R_Typ));
3533 elsif Is_Discrete_Type (T) then
3535 -- The following loop is looking for the nearest compile time known
3536 -- bounds following the ancestor subtype chain. The idea is to find
3537 -- the most restrictive known bounds information.
3541 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3546 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
3547 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
3554 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
3555 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
3561 Ancest := Ancestor_Subtype (Ancest);
3564 Ancest := Base_Type (T);
3566 if Is_Generic_Type (Ancest) then
3572 -- Fixed-point types. We can't simply use Expr_Value to get the
3573 -- Corresponding_Integer_Value values of the bounds, since these do not
3574 -- get set till the type is frozen, and this routine can be called
3575 -- before the type is frozen. Similarly the test for bounds being static
3576 -- needs to include the case where we have unanalyzed real literals for
3579 elsif Is_Fixed_Point_Type (T) then
3581 -- The following loop is looking for the nearest compile time known
3582 -- bounds following the ancestor subtype chain. The idea is to find
3583 -- the most restrictive known bounds information.
3587 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3591 -- Note: In the following two tests for LoSet and HiSet, it may
3592 -- seem redundant to test for N_Real_Literal here since normally
3593 -- one would assume that the test for the value being known at
3594 -- compile time includes this case. However, there is a glitch.
3595 -- If the real literal comes from folding a non-static expression,
3596 -- then we don't consider any non- static expression to be known
3597 -- at compile time if we are in configurable run time mode (needed
3598 -- in some cases to give a clearer definition of what is and what
3599 -- is not accepted). So the test is indeed needed. Without it, we
3600 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
3603 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
3604 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
3606 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
3613 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
3614 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
3616 HiR := Expr_Value_R (Type_High_Bound (Ancest));
3622 Ancest := Ancestor_Subtype (Ancest);
3625 Ancest := Base_Type (T);
3627 if Is_Generic_Type (Ancest) then
3633 Lo := UR_To_Uint (LoR / Small_Value (T));
3634 Hi := UR_To_Uint (HiR / Small_Value (T));
3636 -- No other types allowed
3639 raise Program_Error;
3642 -- Fall through with Hi and Lo set. Deal with biased case
3645 and then not Is_Fixed_Point_Type (T)
3646 and then not (Is_Enumeration_Type (T)
3647 and then Has_Non_Standard_Rep (T)))
3648 or else Has_Biased_Representation (T)
3654 -- Signed case. Note that we consider types like range 1 .. -1 to be
3655 -- signed for the purpose of computing the size, since the bounds have
3656 -- to be accommodated in the base type.
3658 if Lo < 0 or else Hi < 0 then
3662 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
3663 -- Note that we accommodate the case where the bounds cross. This
3664 -- can happen either because of the way the bounds are declared
3665 -- or because of the algorithm in Freeze_Fixed_Point_Type.
3679 -- If both bounds are positive, make sure that both are represen-
3680 -- table in the case where the bounds are crossed. This can happen
3681 -- either because of the way the bounds are declared, or because of
3682 -- the algorithm in Freeze_Fixed_Point_Type.
3688 -- S = size, (can accommodate 0 .. (2**size - 1))
3691 while Hi >= Uint_2 ** S loop
3699 ---------------------------
3700 -- New_Stream_Subprogram --
3701 ---------------------------
3703 procedure New_Stream_Subprogram
3707 Nam : TSS_Name_Type)
3709 Loc : constant Source_Ptr := Sloc (N);
3710 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
3711 Subp_Id : Entity_Id;
3712 Subp_Decl : Node_Id;
3716 Defer_Declaration : constant Boolean :=
3717 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
3718 -- For a tagged type, there is a declaration for each stream attribute
3719 -- at the freeze point, and we must generate only a completion of this
3720 -- declaration. We do the same for private types, because the full view
3721 -- might be tagged. Otherwise we generate a declaration at the point of
3722 -- the attribute definition clause.
3724 function Build_Spec return Node_Id;
3725 -- Used for declaration and renaming declaration, so that this is
3726 -- treated as a renaming_as_body.
3732 function Build_Spec return Node_Id is
3733 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
3736 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
3739 Subp_Id := Make_Defining_Identifier (Loc, Sname);
3741 -- S : access Root_Stream_Type'Class
3743 Formals := New_List (
3744 Make_Parameter_Specification (Loc,
3745 Defining_Identifier =>
3746 Make_Defining_Identifier (Loc, Name_S),
3748 Make_Access_Definition (Loc,
3751 Designated_Type (Etype (F)), Loc))));
3753 if Nam = TSS_Stream_Input then
3754 Spec := Make_Function_Specification (Loc,
3755 Defining_Unit_Name => Subp_Id,
3756 Parameter_Specifications => Formals,
3757 Result_Definition => T_Ref);
3762 Make_Parameter_Specification (Loc,
3763 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
3764 Out_Present => Out_P,
3765 Parameter_Type => T_Ref));
3767 Spec := Make_Procedure_Specification (Loc,
3768 Defining_Unit_Name => Subp_Id,
3769 Parameter_Specifications => Formals);
3775 -- Start of processing for New_Stream_Subprogram
3778 F := First_Formal (Subp);
3780 if Ekind (Subp) = E_Procedure then
3781 Etyp := Etype (Next_Formal (F));
3783 Etyp := Etype (Subp);
3786 -- Prepare subprogram declaration and insert it as an action on the
3787 -- clause node. The visibility for this entity is used to test for
3788 -- visibility of the attribute definition clause (in the sense of
3789 -- 8.3(23) as amended by AI-195).
3791 if not Defer_Declaration then
3793 Make_Subprogram_Declaration (Loc,
3794 Specification => Build_Spec);
3796 -- For a tagged type, there is always a visible declaration for each
3797 -- stream TSS (it is a predefined primitive operation), and the
3798 -- completion of this declaration occurs at the freeze point, which is
3799 -- not always visible at places where the attribute definition clause is
3800 -- visible. So, we create a dummy entity here for the purpose of
3801 -- tracking the visibility of the attribute definition clause itself.
3805 Make_Defining_Identifier (Loc,
3806 Chars => New_External_Name (Sname, 'V'));
3808 Make_Object_Declaration (Loc,
3809 Defining_Identifier => Subp_Id,
3810 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
3813 Insert_Action (N, Subp_Decl);
3814 Set_Entity (N, Subp_Id);
3817 Make_Subprogram_Renaming_Declaration (Loc,
3818 Specification => Build_Spec,
3819 Name => New_Reference_To (Subp, Loc));
3821 if Defer_Declaration then
3822 Set_TSS (Base_Type (Ent), Subp_Id);
3824 Insert_Action (N, Subp_Decl);
3825 Copy_TSS (Subp_Id, Base_Type (Ent));
3827 end New_Stream_Subprogram;
3829 ------------------------
3830 -- Rep_Item_Too_Early --
3831 ------------------------
3833 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
3835 -- Cannot apply non-operational rep items to generic types
3837 if Is_Operational_Item (N) then
3841 and then Is_Generic_Type (Root_Type (T))
3844 ("representation item not allowed for generic type", N);
3848 -- Otherwise check for incomplete type
3850 if Is_Incomplete_Or_Private_Type (T)
3851 and then No (Underlying_Type (T))
3854 ("representation item must be after full type declaration", N);
3857 -- If the type has incomplete components, a representation clause is
3858 -- illegal but stream attributes and Convention pragmas are correct.
3860 elsif Has_Private_Component (T) then
3861 if Nkind (N) = N_Pragma then
3865 ("representation item must appear after type is fully defined",
3872 end Rep_Item_Too_Early;
3874 -----------------------
3875 -- Rep_Item_Too_Late --
3876 -----------------------
3878 function Rep_Item_Too_Late
3881 FOnly : Boolean := False) return Boolean
3884 Parent_Type : Entity_Id;
3887 -- Output the too late message. Note that this is not considered a
3888 -- serious error, since the effect is simply that we ignore the
3889 -- representation clause in this case.
3895 procedure Too_Late is
3897 Error_Msg_N ("|representation item appears too late!", N);
3900 -- Start of processing for Rep_Item_Too_Late
3903 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
3904 -- types, which may be frozen if they appear in a representation clause
3905 -- for a local type.
3908 and then not From_With_Type (T)
3911 S := First_Subtype (T);
3913 if Present (Freeze_Node (S)) then
3915 ("?no more representation items for }", Freeze_Node (S), S);
3920 -- Check for case of non-tagged derived type whose parent either has
3921 -- primitive operations, or is a by reference type (RM 13.1(10)).
3925 and then Is_Derived_Type (T)
3926 and then not Is_Tagged_Type (T)
3928 Parent_Type := Etype (Base_Type (T));
3930 if Has_Primitive_Operations (Parent_Type) then
3933 ("primitive operations already defined for&!", N, Parent_Type);
3936 elsif Is_By_Reference_Type (Parent_Type) then
3939 ("parent type & is a by reference type!", N, Parent_Type);
3944 -- No error, link item into head of chain of rep items for the entity,
3945 -- but avoid chaining if we have an overloadable entity, and the pragma
3946 -- is one that can apply to multiple overloaded entities.
3948 if Is_Overloadable (T)
3949 and then Nkind (N) = N_Pragma
3952 Pname : constant Name_Id := Pragma_Name (N);
3954 if Pname = Name_Convention or else
3955 Pname = Name_Import or else
3956 Pname = Name_Export or else
3957 Pname = Name_External or else
3958 Pname = Name_Interface
3965 Record_Rep_Item (T, N);
3967 end Rep_Item_Too_Late;
3969 -------------------------
3970 -- Same_Representation --
3971 -------------------------
3973 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
3974 T1 : constant Entity_Id := Underlying_Type (Typ1);
3975 T2 : constant Entity_Id := Underlying_Type (Typ2);
3978 -- A quick check, if base types are the same, then we definitely have
3979 -- the same representation, because the subtype specific representation
3980 -- attributes (Size and Alignment) do not affect representation from
3981 -- the point of view of this test.
3983 if Base_Type (T1) = Base_Type (T2) then
3986 elsif Is_Private_Type (Base_Type (T2))
3987 and then Base_Type (T1) = Full_View (Base_Type (T2))
3992 -- Tagged types never have differing representations
3994 if Is_Tagged_Type (T1) then
3998 -- Representations are definitely different if conventions differ
4000 if Convention (T1) /= Convention (T2) then
4004 -- Representations are different if component alignments differ
4006 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
4008 (Is_Record_Type (T2) or else Is_Array_Type (T2))
4009 and then Component_Alignment (T1) /= Component_Alignment (T2)
4014 -- For arrays, the only real issue is component size. If we know the
4015 -- component size for both arrays, and it is the same, then that's
4016 -- good enough to know we don't have a change of representation.
4018 if Is_Array_Type (T1) then
4019 if Known_Component_Size (T1)
4020 and then Known_Component_Size (T2)
4021 and then Component_Size (T1) = Component_Size (T2)
4027 -- Types definitely have same representation if neither has non-standard
4028 -- representation since default representations are always consistent.
4029 -- If only one has non-standard representation, and the other does not,
4030 -- then we consider that they do not have the same representation. They
4031 -- might, but there is no way of telling early enough.
4033 if Has_Non_Standard_Rep (T1) then
4034 if not Has_Non_Standard_Rep (T2) then
4038 return not Has_Non_Standard_Rep (T2);
4041 -- Here the two types both have non-standard representation, and we need
4042 -- to determine if they have the same non-standard representation.
4044 -- For arrays, we simply need to test if the component sizes are the
4045 -- same. Pragma Pack is reflected in modified component sizes, so this
4046 -- check also deals with pragma Pack.
4048 if Is_Array_Type (T1) then
4049 return Component_Size (T1) = Component_Size (T2);
4051 -- Tagged types always have the same representation, because it is not
4052 -- possible to specify different representations for common fields.
4054 elsif Is_Tagged_Type (T1) then
4057 -- Case of record types
4059 elsif Is_Record_Type (T1) then
4061 -- Packed status must conform
4063 if Is_Packed (T1) /= Is_Packed (T2) then
4066 -- Otherwise we must check components. Typ2 maybe a constrained
4067 -- subtype with fewer components, so we compare the components
4068 -- of the base types.
4071 Record_Case : declare
4072 CD1, CD2 : Entity_Id;
4074 function Same_Rep return Boolean;
4075 -- CD1 and CD2 are either components or discriminants. This
4076 -- function tests whether the two have the same representation
4082 function Same_Rep return Boolean is
4084 if No (Component_Clause (CD1)) then
4085 return No (Component_Clause (CD2));
4089 Present (Component_Clause (CD2))
4091 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4093 Esize (CD1) = Esize (CD2);
4097 -- Start of processing for Record_Case
4100 if Has_Discriminants (T1) then
4101 CD1 := First_Discriminant (T1);
4102 CD2 := First_Discriminant (T2);
4104 -- The number of discriminants may be different if the
4105 -- derived type has fewer (constrained by values). The
4106 -- invisible discriminants retain the representation of
4107 -- the original, so the discrepancy does not per se
4108 -- indicate a different representation.
4111 and then Present (CD2)
4113 if not Same_Rep then
4116 Next_Discriminant (CD1);
4117 Next_Discriminant (CD2);
4122 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4123 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4125 while Present (CD1) loop
4126 if not Same_Rep then
4129 Next_Component (CD1);
4130 Next_Component (CD2);
4138 -- For enumeration types, we must check each literal to see if the
4139 -- representation is the same. Note that we do not permit enumeration
4140 -- representation clauses for Character and Wide_Character, so these
4141 -- cases were already dealt with.
4143 elsif Is_Enumeration_Type (T1) then
4145 Enumeration_Case : declare
4149 L1 := First_Literal (T1);
4150 L2 := First_Literal (T2);
4152 while Present (L1) loop
4153 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4163 end Enumeration_Case;
4165 -- Any other types have the same representation for these purposes
4170 end Same_Representation;
4172 --------------------
4173 -- Set_Enum_Esize --
4174 --------------------
4176 procedure Set_Enum_Esize (T : Entity_Id) is
4184 -- Find the minimum standard size (8,16,32,64) that fits
4186 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4187 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4190 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4191 Sz := Standard_Character_Size; -- May be > 8 on some targets
4193 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4196 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4199 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4204 if Hi < Uint_2**08 then
4205 Sz := Standard_Character_Size; -- May be > 8 on some targets
4207 elsif Hi < Uint_2**16 then
4210 elsif Hi < Uint_2**32 then
4213 else pragma Assert (Hi < Uint_2**63);
4218 -- That minimum is the proper size unless we have a foreign convention
4219 -- and the size required is 32 or less, in which case we bump the size
4220 -- up to 32. This is required for C and C++ and seems reasonable for
4221 -- all other foreign conventions.
4223 if Has_Foreign_Convention (T)
4224 and then Esize (T) < Standard_Integer_Size
4226 Init_Esize (T, Standard_Integer_Size);
4232 ------------------------------
4233 -- Validate_Address_Clauses --
4234 ------------------------------
4236 procedure Validate_Address_Clauses is
4238 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4240 ACCR : Address_Clause_Check_Record
4241 renames Address_Clause_Checks.Table (J);
4250 -- Skip processing of this entry if warning already posted
4252 if not Address_Warning_Posted (ACCR.N) then
4254 -- Get alignments. Really we should always have the alignment
4255 -- of the objects properly back annotated, but right now the
4256 -- back end fails to back annotate for address clauses???
4258 if Known_Alignment (ACCR.X) then
4259 X_Alignment := Alignment (ACCR.X);
4261 X_Alignment := Alignment (Etype (ACCR.X));
4264 if Known_Alignment (ACCR.Y) then
4265 Y_Alignment := Alignment (ACCR.Y);
4267 Y_Alignment := Alignment (Etype (ACCR.Y));
4270 -- Similarly obtain sizes
4272 if Known_Esize (ACCR.X) then
4273 X_Size := Esize (ACCR.X);
4275 X_Size := Esize (Etype (ACCR.X));
4278 if Known_Esize (ACCR.Y) then
4279 Y_Size := Esize (ACCR.Y);
4281 Y_Size := Esize (Etype (ACCR.Y));
4284 -- Check for large object overlaying smaller one
4287 and then X_Size > Uint_0
4288 and then X_Size > Y_Size
4291 ("?size for overlaid object is too small", ACCR.N);
4292 Error_Msg_Uint_1 := X_Size;
4294 ("\?size of & is ^", ACCR.N, ACCR.X);
4295 Error_Msg_Uint_1 := Y_Size;
4297 ("\?size of & is ^", ACCR.N, ACCR.Y);
4299 -- Check for inadequate alignment. Again the defensive check
4300 -- on Y_Alignment should not be needed, but because of the
4301 -- failure in back end annotation, we can have an alignment
4304 -- Note: we do not check alignments if we gave a size
4305 -- warning, since it would likely be redundant.
4307 elsif Y_Alignment /= Uint_0
4308 and then Y_Alignment < X_Alignment
4311 ("?specified address for& may be inconsistent "
4315 ("\?program execution may be erroneous (RM 13.3(27))",
4317 Error_Msg_Uint_1 := X_Alignment;
4319 ("\?alignment of & is ^",
4321 Error_Msg_Uint_1 := Y_Alignment;
4323 ("\?alignment of & is ^",
4329 end Validate_Address_Clauses;
4331 -----------------------------------
4332 -- Validate_Unchecked_Conversion --
4333 -----------------------------------
4335 procedure Validate_Unchecked_Conversion
4337 Act_Unit : Entity_Id)
4344 -- Obtain source and target types. Note that we call Ancestor_Subtype
4345 -- here because the processing for generic instantiation always makes
4346 -- subtypes, and we want the original frozen actual types.
4348 -- If we are dealing with private types, then do the check on their
4349 -- fully declared counterparts if the full declarations have been
4350 -- encountered (they don't have to be visible, but they must exist!)
4352 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
4354 if Is_Private_Type (Source)
4355 and then Present (Underlying_Type (Source))
4357 Source := Underlying_Type (Source);
4360 Target := Ancestor_Subtype (Etype (Act_Unit));
4362 -- If either type is generic, the instantiation happens within a generic
4363 -- unit, and there is nothing to check. The proper check
4364 -- will happen when the enclosing generic is instantiated.
4366 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
4370 if Is_Private_Type (Target)
4371 and then Present (Underlying_Type (Target))
4373 Target := Underlying_Type (Target);
4376 -- Source may be unconstrained array, but not target
4378 if Is_Array_Type (Target)
4379 and then not Is_Constrained (Target)
4382 ("unchecked conversion to unconstrained array not allowed", N);
4386 -- Warn if conversion between two different convention pointers
4388 if Is_Access_Type (Target)
4389 and then Is_Access_Type (Source)
4390 and then Convention (Target) /= Convention (Source)
4391 and then Warn_On_Unchecked_Conversion
4393 -- Give warnings for subprogram pointers only on most targets. The
4394 -- exception is VMS, where data pointers can have different lengths
4395 -- depending on the pointer convention.
4397 if Is_Access_Subprogram_Type (Target)
4398 or else Is_Access_Subprogram_Type (Source)
4399 or else OpenVMS_On_Target
4402 ("?conversion between pointers with different conventions!", N);
4406 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4407 -- warning when compiling GNAT-related sources.
4409 if Warn_On_Unchecked_Conversion
4410 and then not In_Predefined_Unit (N)
4411 and then RTU_Loaded (Ada_Calendar)
4413 (Chars (Source) = Name_Time
4415 Chars (Target) = Name_Time)
4417 -- If Ada.Calendar is loaded and the name of one of the operands is
4418 -- Time, there is a good chance that this is Ada.Calendar.Time.
4421 Calendar_Time : constant Entity_Id :=
4422 Full_View (RTE (RO_CA_Time));
4424 pragma Assert (Present (Calendar_Time));
4426 if Source = Calendar_Time
4427 or else Target = Calendar_Time
4430 ("?representation of 'Time values may change between " &
4431 "'G'N'A'T versions", N);
4436 -- Make entry in unchecked conversion table for later processing by
4437 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4438 -- (using values set by the back-end where possible). This is only done
4439 -- if the appropriate warning is active.
4441 if Warn_On_Unchecked_Conversion then
4442 Unchecked_Conversions.Append
4443 (New_Val => UC_Entry'
4448 -- If both sizes are known statically now, then back end annotation
4449 -- is not required to do a proper check but if either size is not
4450 -- known statically, then we need the annotation.
4452 if Known_Static_RM_Size (Source)
4453 and then Known_Static_RM_Size (Target)
4457 Back_Annotate_Rep_Info := True;
4461 -- If unchecked conversion to access type, and access type is declared
4462 -- in the same unit as the unchecked conversion, then set the
4463 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4466 if Is_Access_Type (Target) and then
4467 In_Same_Source_Unit (Target, N)
4469 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4472 -- Generate N_Validate_Unchecked_Conversion node for back end in
4473 -- case the back end needs to perform special validation checks.
4475 -- Shouldn't this be in Exp_Ch13, since the check only gets done
4476 -- if we have full expansion and the back end is called ???
4479 Make_Validate_Unchecked_Conversion (Sloc (N));
4480 Set_Source_Type (Vnode, Source);
4481 Set_Target_Type (Vnode, Target);
4483 -- If the unchecked conversion node is in a list, just insert before it.
4484 -- If not we have some strange case, not worth bothering about.
4486 if Is_List_Member (N) then
4487 Insert_After (N, Vnode);
4489 end Validate_Unchecked_Conversion;
4491 ------------------------------------
4492 -- Validate_Unchecked_Conversions --
4493 ------------------------------------
4495 procedure Validate_Unchecked_Conversions is
4497 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4499 T : UC_Entry renames Unchecked_Conversions.Table (N);
4501 Eloc : constant Source_Ptr := T.Eloc;
4502 Source : constant Entity_Id := T.Source;
4503 Target : constant Entity_Id := T.Target;
4509 -- This validation check, which warns if we have unequal sizes for
4510 -- unchecked conversion, and thus potentially implementation
4511 -- dependent semantics, is one of the few occasions on which we
4512 -- use the official RM size instead of Esize. See description in
4513 -- Einfo "Handling of Type'Size Values" for details.
4515 if Serious_Errors_Detected = 0
4516 and then Known_Static_RM_Size (Source)
4517 and then Known_Static_RM_Size (Target)
4519 -- Don't do the check if warnings off for either type, note the
4520 -- deliberate use of OR here instead of OR ELSE to get the flag
4521 -- Warnings_Off_Used set for both types if appropriate.
4523 and then not (Has_Warnings_Off (Source)
4525 Has_Warnings_Off (Target))
4527 Source_Siz := RM_Size (Source);
4528 Target_Siz := RM_Size (Target);
4530 if Source_Siz /= Target_Siz then
4532 ("?types for unchecked conversion have different sizes!",
4535 if All_Errors_Mode then
4536 Error_Msg_Name_1 := Chars (Source);
4537 Error_Msg_Uint_1 := Source_Siz;
4538 Error_Msg_Name_2 := Chars (Target);
4539 Error_Msg_Uint_2 := Target_Siz;
4540 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
4542 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4544 if Is_Discrete_Type (Source)
4545 and then Is_Discrete_Type (Target)
4547 if Source_Siz > Target_Siz then
4549 ("\?^ high order bits of source will be ignored!",
4552 elsif Is_Unsigned_Type (Source) then
4554 ("\?source will be extended with ^ high order " &
4555 "zero bits?!", Eloc);
4559 ("\?source will be extended with ^ high order " &
4564 elsif Source_Siz < Target_Siz then
4565 if Is_Discrete_Type (Target) then
4566 if Bytes_Big_Endian then
4568 ("\?target value will include ^ undefined " &
4573 ("\?target value will include ^ undefined " &
4580 ("\?^ trailing bits of target value will be " &
4581 "undefined!", Eloc);
4584 else pragma Assert (Source_Siz > Target_Siz);
4586 ("\?^ trailing bits of source will be ignored!",
4593 -- If both types are access types, we need to check the alignment.
4594 -- If the alignment of both is specified, we can do it here.
4596 if Serious_Errors_Detected = 0
4597 and then Ekind (Source) in Access_Kind
4598 and then Ekind (Target) in Access_Kind
4599 and then Target_Strict_Alignment
4600 and then Present (Designated_Type (Source))
4601 and then Present (Designated_Type (Target))
4604 D_Source : constant Entity_Id := Designated_Type (Source);
4605 D_Target : constant Entity_Id := Designated_Type (Target);
4608 if Known_Alignment (D_Source)
4609 and then Known_Alignment (D_Target)
4612 Source_Align : constant Uint := Alignment (D_Source);
4613 Target_Align : constant Uint := Alignment (D_Target);
4616 if Source_Align < Target_Align
4617 and then not Is_Tagged_Type (D_Source)
4619 -- Suppress warning if warnings suppressed on either
4620 -- type or either designated type. Note the use of
4621 -- OR here instead of OR ELSE. That is intentional,
4622 -- we would like to set flag Warnings_Off_Used in
4623 -- all types for which warnings are suppressed.
4625 and then not (Has_Warnings_Off (D_Source)
4627 Has_Warnings_Off (D_Target)
4629 Has_Warnings_Off (Source)
4631 Has_Warnings_Off (Target))
4633 Error_Msg_Uint_1 := Target_Align;
4634 Error_Msg_Uint_2 := Source_Align;
4635 Error_Msg_Node_1 := D_Target;
4636 Error_Msg_Node_2 := D_Source;
4638 ("?alignment of & (^) is stricter than " &
4639 "alignment of & (^)!", Eloc);
4641 ("\?resulting access value may have invalid " &
4642 "alignment!", Eloc);
4650 end Validate_Unchecked_Conversions;