1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2008, 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_Ch8; use Sem_Ch8;
43 with Sem_Eval; use Sem_Eval;
44 with Sem_Res; use Sem_Res;
45 with Sem_Type; use Sem_Type;
46 with Sem_Util; use Sem_Util;
47 with Sem_Warn; use Sem_Warn;
48 with Snames; use Snames;
49 with Stand; use Stand;
50 with Sinfo; use Sinfo;
52 with Targparm; use Targparm;
53 with Ttypes; use Ttypes;
54 with Tbuild; use Tbuild;
55 with Urealp; use Urealp;
57 with GNAT.Heap_Sort_G;
59 package body Sem_Ch13 is
61 SSU : constant Pos := System_Storage_Unit;
62 -- Convenient short hand for commonly used constant
64 -----------------------
65 -- Local Subprograms --
66 -----------------------
68 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
69 -- This routine is called after setting the Esize of type entity Typ.
70 -- The purpose is to deal with the situation where an alignment has been
71 -- inherited from a derived type that is no longer appropriate for the
72 -- new Esize value. In this case, we reset the Alignment to unknown.
74 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
75 -- Given two entities for record components or discriminants, checks
76 -- if they have overlapping component clauses and issues errors if so.
78 function Get_Alignment_Value (Expr : Node_Id) return Uint;
79 -- Given the expression for an alignment value, returns the corresponding
80 -- Uint value. If the value is inappropriate, then error messages are
81 -- posted as required, and a value of No_Uint is returned.
83 function Is_Operational_Item (N : Node_Id) return Boolean;
84 -- A specification for a stream attribute is allowed before the full
85 -- type is declared, as explained in AI-00137 and the corrigendum.
86 -- Attributes that do not specify a representation characteristic are
87 -- operational attributes.
89 function Address_Aliased_Entity (N : Node_Id) return Entity_Id;
90 -- If expression N is of the form E'Address, return E
92 procedure New_Stream_Subprogram
97 -- Create a subprogram renaming of a given stream attribute to the
98 -- designated subprogram and then in the tagged case, provide this as a
99 -- primitive operation, or in the non-tagged case make an appropriate TSS
100 -- entry. This is more properly an expansion activity than just semantics,
101 -- but the presence of user-defined stream functions for limited types is a
102 -- legality check, which is why this takes place here rather than in
103 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
104 -- function to be generated.
106 -- To avoid elaboration anomalies with freeze nodes, for untagged types
107 -- we generate both a subprogram declaration and a subprogram renaming
108 -- declaration, so that the attribute specification is handled as a
109 -- renaming_as_body. For tagged types, the specification is one of the
112 ----------------------------------------------
113 -- Table for Validate_Unchecked_Conversions --
114 ----------------------------------------------
116 -- The following table collects unchecked conversions for validation.
117 -- Entries are made by Validate_Unchecked_Conversion and then the
118 -- call to Validate_Unchecked_Conversions does the actual error
119 -- checking and posting of warnings. The reason for this delayed
120 -- processing is to take advantage of back-annotations of size and
121 -- alignment values performed by the back end.
123 type UC_Entry is record
124 Enode : Node_Id; -- node used for posting warnings
125 Source : Entity_Id; -- source type for unchecked conversion
126 Target : Entity_Id; -- target type for unchecked conversion
129 package Unchecked_Conversions is new Table.Table (
130 Table_Component_Type => UC_Entry,
131 Table_Index_Type => Int,
132 Table_Low_Bound => 1,
134 Table_Increment => 200,
135 Table_Name => "Unchecked_Conversions");
137 ----------------------------------------
138 -- Table for Validate_Address_Clauses --
139 ----------------------------------------
141 -- If an address clause has the form
143 -- for X'Address use Expr
145 -- where Expr is of the form Y'Address or recursively is a reference
146 -- to a constant of either of these forms, and X and Y are entities of
147 -- objects, then if Y has a smaller alignment than X, that merits a
148 -- warning about possible bad alignment. The following table collects
149 -- address clauses of this kind. We put these in a table so that they
150 -- can be checked after the back end has completed annotation of the
151 -- alignments of objects, since we can catch more cases that way.
153 type Address_Clause_Check_Record is record
155 -- The address clause
158 -- The entity of the object overlaying Y
161 -- The entity of the object being overlaid
164 package Address_Clause_Checks is new Table.Table (
165 Table_Component_Type => Address_Clause_Check_Record,
166 Table_Index_Type => Int,
167 Table_Low_Bound => 1,
169 Table_Increment => 200,
170 Table_Name => "Address_Clause_Checks");
172 ----------------------------
173 -- Address_Aliased_Entity --
174 ----------------------------
176 function Address_Aliased_Entity (N : Node_Id) return Entity_Id is
178 if Nkind (N) = N_Attribute_Reference
179 and then Attribute_Name (N) = Name_Address
186 while Nkind_In (P, N_Selected_Component, N_Indexed_Component) loop
190 if Is_Entity_Name (P) then
197 end Address_Aliased_Entity;
199 -----------------------------------------
200 -- Adjust_Record_For_Reverse_Bit_Order --
201 -----------------------------------------
203 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
204 Max_Machine_Scalar_Size : constant Uint :=
206 (Standard_Long_Long_Integer_Size);
207 -- We use this as the maximum machine scalar size in the sense of AI-133
211 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
214 -- This first loop through components does two things. First it deals
215 -- with the case of components with component clauses whose length is
216 -- greater than the maximum machine scalar size (either accepting them
217 -- or rejecting as needed). Second, it counts the number of components
218 -- with component clauses whose length does not exceed this maximum for
222 Comp := First_Component_Or_Discriminant (R);
223 while Present (Comp) loop
225 CC : constant Node_Id := Component_Clause (Comp);
226 Fbit : constant Uint := Static_Integer (First_Bit (CC));
231 -- Case of component with size > max machine scalar
233 if Esize (Comp) > Max_Machine_Scalar_Size then
235 -- Must begin on byte boundary
237 if Fbit mod SSU /= 0 then
239 ("illegal first bit value for reverse bit order",
241 Error_Msg_Uint_1 := SSU;
242 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
245 ("\must be a multiple of ^ if size greater than ^",
248 -- Must end on byte boundary
250 elsif Esize (Comp) mod SSU /= 0 then
252 ("illegal last bit value for reverse bit order",
254 Error_Msg_Uint_1 := SSU;
255 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
258 ("\must be a multiple of ^ if size greater than ^",
261 -- OK, give warning if enabled
263 elsif Warn_On_Reverse_Bit_Order then
265 ("multi-byte field specified with non-standard"
266 & " Bit_Order?", CC);
268 if Bytes_Big_Endian then
270 ("\bytes are not reversed "
271 & "(component is big-endian)?", CC);
274 ("\bytes are not reversed "
275 & "(component is little-endian)?", CC);
279 -- Case where size is not greater than max machine scalar.
280 -- For now, we just count these.
283 Num_CC := Num_CC + 1;
288 Next_Component_Or_Discriminant (Comp);
291 -- We need to sort the component clauses on the basis of the Position
292 -- values in the clause, so we can group clauses with the same Position.
293 -- together to determine the relevant machine scalar size.
296 Comps : array (0 .. Num_CC) of Entity_Id;
297 -- Array to collect component and discriminant entities. The data
298 -- starts at index 1, the 0'th entry is for the sort routine.
300 function CP_Lt (Op1, Op2 : Natural) return Boolean;
301 -- Compare routine for Sort
303 procedure CP_Move (From : Natural; To : Natural);
304 -- Move routine for Sort
306 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
310 -- Start and stop positions in component list of set of components
311 -- with the same starting position (that constitute components in
312 -- a single machine scalar).
315 -- Maximum last bit value of any component in this set
318 -- Corresponding machine scalar size
324 function CP_Lt (Op1, Op2 : Natural) return Boolean is
326 return Position (Component_Clause (Comps (Op1))) <
327 Position (Component_Clause (Comps (Op2)));
334 procedure CP_Move (From : Natural; To : Natural) is
336 Comps (To) := Comps (From);
340 -- Collect the component clauses
343 Comp := First_Component_Or_Discriminant (R);
344 while Present (Comp) loop
345 if Present (Component_Clause (Comp))
346 and then Esize (Comp) <= Max_Machine_Scalar_Size
348 Num_CC := Num_CC + 1;
349 Comps (Num_CC) := Comp;
352 Next_Component_Or_Discriminant (Comp);
355 -- Sort by ascending position number
357 Sorting.Sort (Num_CC);
359 -- We now have all the components whose size does not exceed the max
360 -- machine scalar value, sorted by starting position. In this loop
361 -- we gather groups of clauses starting at the same position, to
362 -- process them in accordance with Ada 2005 AI-133.
365 while Stop < Num_CC loop
369 Static_Integer (Last_Bit (Component_Clause (Comps (Start))));
370 while Stop < Num_CC loop
372 (Position (Component_Clause (Comps (Stop + 1)))) =
374 (Position (Component_Clause (Comps (Stop))))
381 (Last_Bit (Component_Clause (Comps (Stop)))));
387 -- Now we have a group of component clauses from Start to Stop
388 -- whose positions are identical, and MaxL is the maximum last bit
389 -- value of any of these components.
391 -- We need to determine the corresponding machine scalar size.
392 -- This loop assumes that machine scalar sizes are even, and that
393 -- each possible machine scalar has twice as many bits as the
396 MSS := Max_Machine_Scalar_Size;
398 and then (MSS / 2) >= SSU
399 and then (MSS / 2) > MaxL
404 -- Here is where we fix up the Component_Bit_Offset value to
405 -- account for the reverse bit order. Some examples of what needs
406 -- to be done for the case of a machine scalar size of 8 are:
408 -- First_Bit .. Last_Bit Component_Bit_Offset
420 -- The general rule is that the first bit is is obtained by
421 -- subtracting the old ending bit from machine scalar size - 1.
423 for C in Start .. Stop loop
425 Comp : constant Entity_Id := Comps (C);
426 CC : constant Node_Id := Component_Clause (Comp);
427 LB : constant Uint := Static_Integer (Last_Bit (CC));
428 NFB : constant Uint := MSS - Uint_1 - LB;
429 NLB : constant Uint := NFB + Esize (Comp) - 1;
430 Pos : constant Uint := Static_Integer (Position (CC));
433 if Warn_On_Reverse_Bit_Order then
434 Error_Msg_Uint_1 := MSS;
436 ("?reverse bit order in machine " &
437 "scalar of length^", First_Bit (CC));
438 Error_Msg_Uint_1 := NFB;
439 Error_Msg_Uint_2 := NLB;
441 if Bytes_Big_Endian then
443 ("?\big-endian range for component & is ^ .. ^",
444 First_Bit (CC), Comp);
447 ("?\little-endian range for component & is ^ .. ^",
448 First_Bit (CC), Comp);
452 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
453 Set_Normalized_First_Bit (Comp, NFB mod SSU);
458 end Adjust_Record_For_Reverse_Bit_Order;
460 --------------------------------------
461 -- Alignment_Check_For_Esize_Change --
462 --------------------------------------
464 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
466 -- If the alignment is known, and not set by a rep clause, and is
467 -- inconsistent with the size being set, then reset it to unknown,
468 -- we assume in this case that the size overrides the inherited
469 -- alignment, and that the alignment must be recomputed.
471 if Known_Alignment (Typ)
472 and then not Has_Alignment_Clause (Typ)
473 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
475 Init_Alignment (Typ);
477 end Alignment_Check_For_Esize_Change;
479 -----------------------
480 -- Analyze_At_Clause --
481 -----------------------
483 -- An at clause is replaced by the corresponding Address attribute
484 -- definition clause that is the preferred approach in Ada 95.
486 procedure Analyze_At_Clause (N : Node_Id) is
487 CS : constant Boolean := Comes_From_Source (N);
490 -- This is an obsolescent feature
492 Check_Restriction (No_Obsolescent_Features, N);
494 if Warn_On_Obsolescent_Feature then
496 ("at clause is an obsolescent feature (RM J.7(2))?", N);
498 ("\use address attribute definition clause instead?", N);
501 -- Rewrite as address clause
504 Make_Attribute_Definition_Clause (Sloc (N),
505 Name => Identifier (N),
506 Chars => Name_Address,
507 Expression => Expression (N)));
509 -- We preserve Comes_From_Source, since logically the clause still
510 -- comes from the source program even though it is changed in form.
512 Set_Comes_From_Source (N, CS);
514 -- Analyze rewritten clause
516 Analyze_Attribute_Definition_Clause (N);
517 end Analyze_At_Clause;
519 -----------------------------------------
520 -- Analyze_Attribute_Definition_Clause --
521 -----------------------------------------
523 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
524 Loc : constant Source_Ptr := Sloc (N);
525 Nam : constant Node_Id := Name (N);
526 Attr : constant Name_Id := Chars (N);
527 Expr : constant Node_Id := Expression (N);
528 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
532 FOnly : Boolean := False;
533 -- Reset to True for subtype specific attribute (Alignment, Size)
534 -- and for stream attributes, i.e. those cases where in the call
535 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
536 -- rules are checked. Note that the case of stream attributes is not
537 -- clear from the RM, but see AI95-00137. Also, the RM seems to
538 -- disallow Storage_Size for derived task types, but that is also
539 -- clearly unintentional.
541 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
542 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
543 -- definition clauses.
545 -----------------------------------
546 -- Analyze_Stream_TSS_Definition --
547 -----------------------------------
549 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
550 Subp : Entity_Id := Empty;
555 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
557 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
558 -- Return true if the entity is a subprogram with an appropriate
559 -- profile for the attribute being defined.
561 ----------------------
562 -- Has_Good_Profile --
563 ----------------------
565 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
567 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
568 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
569 (False => E_Procedure, True => E_Function);
573 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
577 F := First_Formal (Subp);
580 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
581 or else Designated_Type (Etype (F)) /=
582 Class_Wide_Type (RTE (RE_Root_Stream_Type))
587 if not Is_Function then
591 Expected_Mode : constant array (Boolean) of Entity_Kind :=
592 (False => E_In_Parameter,
593 True => E_Out_Parameter);
595 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
606 return Base_Type (Typ) = Base_Type (Ent)
607 and then No (Next_Formal (F));
608 end Has_Good_Profile;
610 -- Start of processing for Analyze_Stream_TSS_Definition
615 if not Is_Type (U_Ent) then
616 Error_Msg_N ("local name must be a subtype", Nam);
620 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
622 -- If Pnam is present, it can be either inherited from an ancestor
623 -- type (in which case it is legal to redefine it for this type), or
624 -- be a previous definition of the attribute for the same type (in
625 -- which case it is illegal).
627 -- In the first case, it will have been analyzed already, and we
628 -- can check that its profile does not match the expected profile
629 -- for a stream attribute of U_Ent. In the second case, either Pnam
630 -- has been analyzed (and has the expected profile), or it has not
631 -- been analyzed yet (case of a type that has not been frozen yet
632 -- and for which the stream attribute has been set using Set_TSS).
635 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
637 Error_Msg_Sloc := Sloc (Pnam);
638 Error_Msg_Name_1 := Attr;
639 Error_Msg_N ("% attribute already defined #", Nam);
645 if Is_Entity_Name (Expr) then
646 if not Is_Overloaded (Expr) then
647 if Has_Good_Profile (Entity (Expr)) then
648 Subp := Entity (Expr);
652 Get_First_Interp (Expr, I, It);
653 while Present (It.Nam) loop
654 if Has_Good_Profile (It.Nam) then
659 Get_Next_Interp (I, It);
664 if Present (Subp) then
665 if Is_Abstract_Subprogram (Subp) then
666 Error_Msg_N ("stream subprogram must not be abstract", Expr);
670 Set_Entity (Expr, Subp);
671 Set_Etype (Expr, Etype (Subp));
673 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
676 Error_Msg_Name_1 := Attr;
677 Error_Msg_N ("incorrect expression for% attribute", Expr);
679 end Analyze_Stream_TSS_Definition;
681 -- Start of processing for Analyze_Attribute_Definition_Clause
684 if Ignore_Rep_Clauses then
685 Rewrite (N, Make_Null_Statement (Sloc (N)));
692 if Rep_Item_Too_Early (Ent, N) then
696 -- Rep clause applies to full view of incomplete type or private type if
697 -- we have one (if not, this is a premature use of the type). However,
698 -- certain semantic checks need to be done on the specified entity (i.e.
699 -- the private view), so we save it in Ent.
701 if Is_Private_Type (Ent)
702 and then Is_Derived_Type (Ent)
703 and then not Is_Tagged_Type (Ent)
704 and then No (Full_View (Ent))
706 -- If this is a private type whose completion is a derivation from
707 -- another private type, there is no full view, and the attribute
708 -- belongs to the type itself, not its underlying parent.
712 elsif Ekind (Ent) = E_Incomplete_Type then
714 -- The attribute applies to the full view, set the entity of the
715 -- attribute definition accordingly.
717 Ent := Underlying_Type (Ent);
719 Set_Entity (Nam, Ent);
722 U_Ent := Underlying_Type (Ent);
725 -- Complete other routine error checks
727 if Etype (Nam) = Any_Type then
730 elsif Scope (Ent) /= Current_Scope then
731 Error_Msg_N ("entity must be declared in this scope", Nam);
734 elsif No (U_Ent) then
737 elsif Is_Type (U_Ent)
738 and then not Is_First_Subtype (U_Ent)
739 and then Id /= Attribute_Object_Size
740 and then Id /= Attribute_Value_Size
741 and then not From_At_Mod (N)
743 Error_Msg_N ("cannot specify attribute for subtype", Nam);
747 -- Switch on particular attribute
755 -- Address attribute definition clause
757 when Attribute_Address => Address : begin
759 -- A little error check, catch for X'Address use X'Address;
761 if Nkind (Nam) = N_Identifier
762 and then Nkind (Expr) = N_Attribute_Reference
763 and then Attribute_Name (Expr) = Name_Address
764 and then Nkind (Prefix (Expr)) = N_Identifier
765 and then Chars (Nam) = Chars (Prefix (Expr))
768 ("address for & is self-referencing", Prefix (Expr), Ent);
772 -- Not that special case, carry on with analysis of expression
774 Analyze_And_Resolve (Expr, RTE (RE_Address));
776 if Present (Address_Clause (U_Ent)) then
777 Error_Msg_N ("address already given for &", Nam);
779 -- Case of address clause for subprogram
781 elsif Is_Subprogram (U_Ent) then
782 if Has_Homonym (U_Ent) then
784 ("address clause cannot be given " &
785 "for overloaded subprogram",
790 -- For subprograms, all address clauses are permitted, and we
791 -- mark the subprogram as having a deferred freeze so that Gigi
792 -- will not elaborate it too soon.
794 -- Above needs more comments, what is too soon about???
796 Set_Has_Delayed_Freeze (U_Ent);
798 -- Case of address clause for entry
800 elsif Ekind (U_Ent) = E_Entry then
801 if Nkind (Parent (N)) = N_Task_Body then
803 ("entry address must be specified in task spec", Nam);
807 -- For entries, we require a constant address
809 Check_Constant_Address_Clause (Expr, U_Ent);
811 -- Special checks for task types
813 if Is_Task_Type (Scope (U_Ent))
814 and then Comes_From_Source (Scope (U_Ent))
817 ("?entry address declared for entry in task type", N);
819 ("\?only one task can be declared of this type", N);
822 -- Entry address clauses are obsolescent
824 Check_Restriction (No_Obsolescent_Features, N);
826 if Warn_On_Obsolescent_Feature then
828 ("attaching interrupt to task entry is an " &
829 "obsolescent feature (RM J.7.1)?", N);
831 ("\use interrupt procedure instead?", N);
834 -- Case of an address clause for a controlled object which we
835 -- consider to be erroneous.
837 elsif Is_Controlled (Etype (U_Ent))
838 or else Has_Controlled_Component (Etype (U_Ent))
841 ("?controlled object& must not be overlaid", Nam, U_Ent);
843 ("\?Program_Error will be raised at run time", Nam);
844 Insert_Action (Declaration_Node (U_Ent),
845 Make_Raise_Program_Error (Loc,
846 Reason => PE_Overlaid_Controlled_Object));
849 -- Case of address clause for a (non-controlled) object
852 Ekind (U_Ent) = E_Variable
854 Ekind (U_Ent) = E_Constant
857 Expr : constant Node_Id := Expression (N);
858 Aent : constant Entity_Id := Address_Aliased_Entity (Expr);
859 Ent_Y : constant Entity_Id := Find_Overlaid_Object (N);
862 -- Exported variables cannot have an address clause,
863 -- because this cancels the effect of the pragma Export
865 if Is_Exported (U_Ent) then
867 ("cannot export object with address clause", Nam);
870 -- Overlaying controlled objects is erroneous
873 and then (Has_Controlled_Component (Etype (Aent))
874 or else Is_Controlled (Etype (Aent)))
877 ("?cannot overlay with controlled object", Expr);
879 ("\?Program_Error will be raised at run time", Expr);
880 Insert_Action (Declaration_Node (U_Ent),
881 Make_Raise_Program_Error (Loc,
882 Reason => PE_Overlaid_Controlled_Object));
886 and then Ekind (U_Ent) = E_Constant
887 and then Ekind (Aent) /= E_Constant
889 Error_Msg_N ("constant overlays a variable?", Expr);
891 elsif Present (Renamed_Object (U_Ent)) then
893 ("address clause not allowed"
894 & " for a renaming declaration (RM 13.1(6))", Nam);
897 -- Imported variables can have an address clause, but then
898 -- the import is pretty meaningless except to suppress
899 -- initializations, so we do not need such variables to
900 -- be statically allocated (and in fact it causes trouble
901 -- if the address clause is a local value).
903 elsif Is_Imported (U_Ent) then
904 Set_Is_Statically_Allocated (U_Ent, False);
907 -- We mark a possible modification of a variable with an
908 -- address clause, since it is likely aliasing is occurring.
910 Note_Possible_Modification (Nam, Sure => False);
912 -- Here we are checking for explicit overlap of one variable
913 -- by another, and if we find this then mark the overlapped
914 -- variable as also being volatile to prevent unwanted
917 if Present (Ent_Y) then
918 Set_Treat_As_Volatile (Ent_Y);
921 -- Legality checks on the address clause for initialized
922 -- objects is deferred until the freeze point, because
923 -- a subsequent pragma might indicate that the object is
924 -- imported and thus not initialized.
926 Set_Has_Delayed_Freeze (U_Ent);
928 if Is_Exported (U_Ent) then
930 ("& cannot be exported if an address clause is given",
933 ("\define and export a variable " &
934 "that holds its address instead",
938 -- Entity has delayed freeze, so we will generate an
939 -- alignment check at the freeze point unless suppressed.
941 if not Range_Checks_Suppressed (U_Ent)
942 and then not Alignment_Checks_Suppressed (U_Ent)
944 Set_Check_Address_Alignment (N);
947 -- Kill the size check code, since we are not allocating
948 -- the variable, it is somewhere else.
950 Kill_Size_Check_Code (U_Ent);
953 -- If the address clause is of the form:
955 -- for Y'Address use X'Address
959 -- Const : constant Address := X'Address;
961 -- for Y'Address use Const;
963 -- then we make an entry in the table for checking the size and
964 -- alignment of the overlaying variable. We defer this check
965 -- till after code generation to take full advantage of the
966 -- annotation done by the back end. This entry is only made if
967 -- we have not already posted a warning about size/alignment
968 -- (some warnings of this type are posted in Checks), and if
969 -- the address clause comes from source.
971 if Address_Clause_Overlay_Warnings
972 and then Comes_From_Source (N)
975 Ent_X : Entity_Id := Empty;
976 Ent_Y : Entity_Id := Empty;
979 Ent_Y := Find_Overlaid_Object (N);
981 if Present (Ent_Y) and then Is_Entity_Name (Name (N)) then
982 Ent_X := Entity (Name (N));
983 Address_Clause_Checks.Append ((N, Ent_X, Ent_Y));
985 -- If variable overlays a constant view, and we are
986 -- warning on overlays, then mark the variable as
987 -- overlaying a constant (we will give warnings later
988 -- if this variable is assigned).
990 if Is_Constant_Object (Ent_Y)
991 and then Ekind (Ent_X) = E_Variable
993 Set_Overlays_Constant (Ent_X);
999 -- Not a valid entity for an address clause
1002 Error_Msg_N ("address cannot be given for &", Nam);
1010 -- Alignment attribute definition clause
1012 when Attribute_Alignment => Alignment_Block : declare
1013 Align : constant Uint := Get_Alignment_Value (Expr);
1018 if not Is_Type (U_Ent)
1019 and then Ekind (U_Ent) /= E_Variable
1020 and then Ekind (U_Ent) /= E_Constant
1022 Error_Msg_N ("alignment cannot be given for &", Nam);
1024 elsif Has_Alignment_Clause (U_Ent) then
1025 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1026 Error_Msg_N ("alignment clause previously given#", N);
1028 elsif Align /= No_Uint then
1029 Set_Has_Alignment_Clause (U_Ent);
1030 Set_Alignment (U_Ent, Align);
1032 end Alignment_Block;
1038 -- Bit_Order attribute definition clause
1040 when Attribute_Bit_Order => Bit_Order : declare
1042 if not Is_Record_Type (U_Ent) then
1044 ("Bit_Order can only be defined for record type", Nam);
1047 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1049 if Etype (Expr) = Any_Type then
1052 elsif not Is_Static_Expression (Expr) then
1053 Flag_Non_Static_Expr
1054 ("Bit_Order requires static expression!", Expr);
1057 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1058 Set_Reverse_Bit_Order (U_Ent, True);
1064 --------------------
1065 -- Component_Size --
1066 --------------------
1068 -- Component_Size attribute definition clause
1070 when Attribute_Component_Size => Component_Size_Case : declare
1071 Csize : constant Uint := Static_Integer (Expr);
1074 New_Ctyp : Entity_Id;
1078 if not Is_Array_Type (U_Ent) then
1079 Error_Msg_N ("component size requires array type", Nam);
1083 Btype := Base_Type (U_Ent);
1085 if Has_Component_Size_Clause (Btype) then
1087 ("component size clause for& previously given", Nam);
1089 elsif Csize /= No_Uint then
1090 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
1092 if Has_Aliased_Components (Btype)
1095 and then Csize /= 16
1098 ("component size incorrect for aliased components", N);
1102 -- For the biased case, build a declaration for a subtype
1103 -- that will be used to represent the biased subtype that
1104 -- reflects the biased representation of components. We need
1105 -- this subtype to get proper conversions on referencing
1106 -- elements of the array. Note that component size clauses
1107 -- are ignored in VM mode.
1109 if VM_Target = No_VM then
1112 Make_Defining_Identifier (Loc,
1114 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1117 Make_Subtype_Declaration (Loc,
1118 Defining_Identifier => New_Ctyp,
1119 Subtype_Indication =>
1120 New_Occurrence_Of (Component_Type (Btype), Loc));
1122 Set_Parent (Decl, N);
1123 Analyze (Decl, Suppress => All_Checks);
1125 Set_Has_Delayed_Freeze (New_Ctyp, False);
1126 Set_Esize (New_Ctyp, Csize);
1127 Set_RM_Size (New_Ctyp, Csize);
1128 Init_Alignment (New_Ctyp);
1129 Set_Has_Biased_Representation (New_Ctyp, True);
1130 Set_Is_Itype (New_Ctyp, True);
1131 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1133 Set_Component_Type (Btype, New_Ctyp);
1136 Set_Component_Size (Btype, Csize);
1138 -- For VM case, we ignore component size clauses
1141 -- Give a warning unless we are in GNAT mode, in which case
1142 -- the warning is suppressed since it is not useful.
1144 if not GNAT_Mode then
1146 ("?component size ignored in this configuration", N);
1150 Set_Has_Component_Size_Clause (Btype, True);
1151 Set_Has_Non_Standard_Rep (Btype, True);
1153 end Component_Size_Case;
1159 when Attribute_External_Tag => External_Tag :
1161 if not Is_Tagged_Type (U_Ent) then
1162 Error_Msg_N ("should be a tagged type", Nam);
1165 Analyze_And_Resolve (Expr, Standard_String);
1167 if not Is_Static_Expression (Expr) then
1168 Flag_Non_Static_Expr
1169 ("static string required for tag name!", Nam);
1172 if VM_Target = No_VM then
1173 Set_Has_External_Tag_Rep_Clause (U_Ent);
1174 elsif not Inspector_Mode then
1175 Error_Msg_Name_1 := Attr;
1177 ("% attribute unsupported in this configuration", Nam);
1180 if not Is_Library_Level_Entity (U_Ent) then
1182 ("?non-unique external tag supplied for &", N, U_Ent);
1184 ("?\same external tag applies to all subprogram calls", N);
1186 ("?\corresponding internal tag cannot be obtained", N);
1194 when Attribute_Input =>
1195 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1196 Set_Has_Specified_Stream_Input (Ent);
1202 -- Machine radix attribute definition clause
1204 when Attribute_Machine_Radix => Machine_Radix : declare
1205 Radix : constant Uint := Static_Integer (Expr);
1208 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1209 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1211 elsif Has_Machine_Radix_Clause (U_Ent) then
1212 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1213 Error_Msg_N ("machine radix clause previously given#", N);
1215 elsif Radix /= No_Uint then
1216 Set_Has_Machine_Radix_Clause (U_Ent);
1217 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1221 elsif Radix = 10 then
1222 Set_Machine_Radix_10 (U_Ent);
1224 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1233 -- Object_Size attribute definition clause
1235 when Attribute_Object_Size => Object_Size : declare
1236 Size : constant Uint := Static_Integer (Expr);
1239 pragma Warnings (Off, Biased);
1242 if not Is_Type (U_Ent) then
1243 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1245 elsif Has_Object_Size_Clause (U_Ent) then
1246 Error_Msg_N ("Object_Size already given for &", Nam);
1249 Check_Size (Expr, U_Ent, Size, Biased);
1257 UI_Mod (Size, 64) /= 0
1260 ("Object_Size must be 8, 16, 32, or multiple of 64",
1264 Set_Esize (U_Ent, Size);
1265 Set_Has_Object_Size_Clause (U_Ent);
1266 Alignment_Check_For_Esize_Change (U_Ent);
1274 when Attribute_Output =>
1275 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1276 Set_Has_Specified_Stream_Output (Ent);
1282 when Attribute_Read =>
1283 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1284 Set_Has_Specified_Stream_Read (Ent);
1290 -- Size attribute definition clause
1292 when Attribute_Size => Size : declare
1293 Size : constant Uint := Static_Integer (Expr);
1300 if Has_Size_Clause (U_Ent) then
1301 Error_Msg_N ("size already given for &", Nam);
1303 elsif not Is_Type (U_Ent)
1304 and then Ekind (U_Ent) /= E_Variable
1305 and then Ekind (U_Ent) /= E_Constant
1307 Error_Msg_N ("size cannot be given for &", Nam);
1309 elsif Is_Array_Type (U_Ent)
1310 and then not Is_Constrained (U_Ent)
1313 ("size cannot be given for unconstrained array", Nam);
1315 elsif Size /= No_Uint then
1316 if Is_Type (U_Ent) then
1319 Etyp := Etype (U_Ent);
1322 -- Check size, note that Gigi is in charge of checking that the
1323 -- size of an array or record type is OK. Also we do not check
1324 -- the size in the ordinary fixed-point case, since it is too
1325 -- early to do so (there may be subsequent small clause that
1326 -- affects the size). We can check the size if a small clause
1327 -- has already been given.
1329 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1330 or else Has_Small_Clause (U_Ent)
1332 Check_Size (Expr, Etyp, Size, Biased);
1333 Set_Has_Biased_Representation (U_Ent, Biased);
1336 -- For types set RM_Size and Esize if possible
1338 if Is_Type (U_Ent) then
1339 Set_RM_Size (U_Ent, Size);
1341 -- For scalar types, increase Object_Size to power of 2, but
1342 -- not less than a storage unit in any case (i.e., normally
1343 -- this means it will be byte addressable).
1345 if Is_Scalar_Type (U_Ent) then
1346 if Size <= System_Storage_Unit then
1347 Init_Esize (U_Ent, System_Storage_Unit);
1348 elsif Size <= 16 then
1349 Init_Esize (U_Ent, 16);
1350 elsif Size <= 32 then
1351 Init_Esize (U_Ent, 32);
1353 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1356 -- For all other types, object size = value size. The
1357 -- backend will adjust as needed.
1360 Set_Esize (U_Ent, Size);
1363 Alignment_Check_For_Esize_Change (U_Ent);
1365 -- For objects, set Esize only
1368 if Is_Elementary_Type (Etyp) then
1369 if Size /= System_Storage_Unit
1371 Size /= System_Storage_Unit * 2
1373 Size /= System_Storage_Unit * 4
1375 Size /= System_Storage_Unit * 8
1377 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1378 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1380 ("size for primitive object must be a power of 2"
1381 & " in the range ^-^", N);
1385 Set_Esize (U_Ent, Size);
1388 Set_Has_Size_Clause (U_Ent);
1396 -- Small attribute definition clause
1398 when Attribute_Small => Small : declare
1399 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1403 Analyze_And_Resolve (Expr, Any_Real);
1405 if Etype (Expr) = Any_Type then
1408 elsif not Is_Static_Expression (Expr) then
1409 Flag_Non_Static_Expr
1410 ("small requires static expression!", Expr);
1414 Small := Expr_Value_R (Expr);
1416 if Small <= Ureal_0 then
1417 Error_Msg_N ("small value must be greater than zero", Expr);
1423 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1425 ("small requires an ordinary fixed point type", Nam);
1427 elsif Has_Small_Clause (U_Ent) then
1428 Error_Msg_N ("small already given for &", Nam);
1430 elsif Small > Delta_Value (U_Ent) then
1432 ("small value must not be greater then delta value", Nam);
1435 Set_Small_Value (U_Ent, Small);
1436 Set_Small_Value (Implicit_Base, Small);
1437 Set_Has_Small_Clause (U_Ent);
1438 Set_Has_Small_Clause (Implicit_Base);
1439 Set_Has_Non_Standard_Rep (Implicit_Base);
1447 -- Storage_Pool attribute definition clause
1449 when Attribute_Storage_Pool => Storage_Pool : declare
1454 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1456 ("storage pool cannot be given for access-to-subprogram type",
1460 elsif Ekind (U_Ent) /= E_Access_Type
1461 and then Ekind (U_Ent) /= E_General_Access_Type
1464 ("storage pool can only be given for access types", Nam);
1467 elsif Is_Derived_Type (U_Ent) then
1469 ("storage pool cannot be given for a derived access type",
1472 elsif Has_Storage_Size_Clause (U_Ent) then
1473 Error_Msg_N ("storage size already given for &", Nam);
1476 elsif Present (Associated_Storage_Pool (U_Ent)) then
1477 Error_Msg_N ("storage pool already given for &", Nam);
1482 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1484 if not Denotes_Variable (Expr) then
1485 Error_Msg_N ("storage pool must be a variable", Expr);
1489 if Nkind (Expr) = N_Type_Conversion then
1490 T := Etype (Expression (Expr));
1495 -- The Stack_Bounded_Pool is used internally for implementing
1496 -- access types with a Storage_Size. Since it only work
1497 -- properly when used on one specific type, we need to check
1498 -- that it is not hijacked improperly:
1499 -- type T is access Integer;
1500 -- for T'Storage_Size use n;
1501 -- type Q is access Float;
1502 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1504 if RTE_Available (RE_Stack_Bounded_Pool)
1505 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1507 Error_Msg_N ("non-shareable internal Pool", Expr);
1511 -- If the argument is a name that is not an entity name, then
1512 -- we construct a renaming operation to define an entity of
1513 -- type storage pool.
1515 if not Is_Entity_Name (Expr)
1516 and then Is_Object_Reference (Expr)
1519 Make_Defining_Identifier (Loc,
1520 Chars => New_Internal_Name ('P'));
1523 Rnode : constant Node_Id :=
1524 Make_Object_Renaming_Declaration (Loc,
1525 Defining_Identifier => Pool,
1527 New_Occurrence_Of (Etype (Expr), Loc),
1531 Insert_Before (N, Rnode);
1533 Set_Associated_Storage_Pool (U_Ent, Pool);
1536 elsif Is_Entity_Name (Expr) then
1537 Pool := Entity (Expr);
1539 -- If pool is a renamed object, get original one. This can
1540 -- happen with an explicit renaming, and within instances.
1542 while Present (Renamed_Object (Pool))
1543 and then Is_Entity_Name (Renamed_Object (Pool))
1545 Pool := Entity (Renamed_Object (Pool));
1548 if Present (Renamed_Object (Pool))
1549 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1550 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1552 Pool := Entity (Expression (Renamed_Object (Pool)));
1555 Set_Associated_Storage_Pool (U_Ent, Pool);
1557 elsif Nkind (Expr) = N_Type_Conversion
1558 and then Is_Entity_Name (Expression (Expr))
1559 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1561 Pool := Entity (Expression (Expr));
1562 Set_Associated_Storage_Pool (U_Ent, Pool);
1565 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1574 -- Storage_Size attribute definition clause
1576 when Attribute_Storage_Size => Storage_Size : declare
1577 Btype : constant Entity_Id := Base_Type (U_Ent);
1581 if Is_Task_Type (U_Ent) then
1582 Check_Restriction (No_Obsolescent_Features, N);
1584 if Warn_On_Obsolescent_Feature then
1586 ("storage size clause for task is an " &
1587 "obsolescent feature (RM J.9)?", N);
1589 ("\use Storage_Size pragma instead?", N);
1595 if not Is_Access_Type (U_Ent)
1596 and then Ekind (U_Ent) /= E_Task_Type
1598 Error_Msg_N ("storage size cannot be given for &", Nam);
1600 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1602 ("storage size cannot be given for a derived access type",
1605 elsif Has_Storage_Size_Clause (Btype) then
1606 Error_Msg_N ("storage size already given for &", Nam);
1609 Analyze_And_Resolve (Expr, Any_Integer);
1611 if Is_Access_Type (U_Ent) then
1612 if Present (Associated_Storage_Pool (U_Ent)) then
1613 Error_Msg_N ("storage pool already given for &", Nam);
1617 if Compile_Time_Known_Value (Expr)
1618 and then Expr_Value (Expr) = 0
1620 Set_No_Pool_Assigned (Btype);
1623 else -- Is_Task_Type (U_Ent)
1624 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1626 if Present (Sprag) then
1627 Error_Msg_Sloc := Sloc (Sprag);
1629 ("Storage_Size already specified#", Nam);
1634 Set_Has_Storage_Size_Clause (Btype);
1642 when Attribute_Stream_Size => Stream_Size : declare
1643 Size : constant Uint := Static_Integer (Expr);
1646 if Ada_Version <= Ada_95 then
1647 Check_Restriction (No_Implementation_Attributes, N);
1650 if Has_Stream_Size_Clause (U_Ent) then
1651 Error_Msg_N ("Stream_Size already given for &", Nam);
1653 elsif Is_Elementary_Type (U_Ent) then
1654 if Size /= System_Storage_Unit
1656 Size /= System_Storage_Unit * 2
1658 Size /= System_Storage_Unit * 4
1660 Size /= System_Storage_Unit * 8
1662 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1664 ("stream size for elementary type must be a"
1665 & " power of 2 and at least ^", N);
1667 elsif RM_Size (U_Ent) > Size then
1668 Error_Msg_Uint_1 := RM_Size (U_Ent);
1670 ("stream size for elementary type must be a"
1671 & " power of 2 and at least ^", N);
1674 Set_Has_Stream_Size_Clause (U_Ent);
1677 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1685 -- Value_Size attribute definition clause
1687 when Attribute_Value_Size => Value_Size : declare
1688 Size : constant Uint := Static_Integer (Expr);
1692 if not Is_Type (U_Ent) then
1693 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1696 (Get_Attribute_Definition_Clause
1697 (U_Ent, Attribute_Value_Size))
1699 Error_Msg_N ("Value_Size already given for &", Nam);
1701 elsif Is_Array_Type (U_Ent)
1702 and then not Is_Constrained (U_Ent)
1705 ("Value_Size cannot be given for unconstrained array", Nam);
1708 if Is_Elementary_Type (U_Ent) then
1709 Check_Size (Expr, U_Ent, Size, Biased);
1710 Set_Has_Biased_Representation (U_Ent, Biased);
1713 Set_RM_Size (U_Ent, Size);
1721 when Attribute_Write =>
1722 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1723 Set_Has_Specified_Stream_Write (Ent);
1725 -- All other attributes cannot be set
1729 ("attribute& cannot be set with definition clause", N);
1732 -- The test for the type being frozen must be performed after
1733 -- any expression the clause has been analyzed since the expression
1734 -- itself might cause freezing that makes the clause illegal.
1736 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1739 end Analyze_Attribute_Definition_Clause;
1741 ----------------------------
1742 -- Analyze_Code_Statement --
1743 ----------------------------
1745 procedure Analyze_Code_Statement (N : Node_Id) is
1746 HSS : constant Node_Id := Parent (N);
1747 SBody : constant Node_Id := Parent (HSS);
1748 Subp : constant Entity_Id := Current_Scope;
1755 -- Analyze and check we get right type, note that this implements the
1756 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1757 -- is the only way that Asm_Insn could possibly be visible.
1759 Analyze_And_Resolve (Expression (N));
1761 if Etype (Expression (N)) = Any_Type then
1763 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1764 Error_Msg_N ("incorrect type for code statement", N);
1768 Check_Code_Statement (N);
1770 -- Make sure we appear in the handled statement sequence of a
1771 -- subprogram (RM 13.8(3)).
1773 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
1774 or else Nkind (SBody) /= N_Subprogram_Body
1777 ("code statement can only appear in body of subprogram", N);
1781 -- Do remaining checks (RM 13.8(3)) if not already done
1783 if not Is_Machine_Code_Subprogram (Subp) then
1784 Set_Is_Machine_Code_Subprogram (Subp);
1786 -- No exception handlers allowed
1788 if Present (Exception_Handlers (HSS)) then
1790 ("exception handlers not permitted in machine code subprogram",
1791 First (Exception_Handlers (HSS)));
1794 -- No declarations other than use clauses and pragmas (we allow
1795 -- certain internally generated declarations as well).
1797 Decl := First (Declarations (SBody));
1798 while Present (Decl) loop
1799 DeclO := Original_Node (Decl);
1800 if Comes_From_Source (DeclO)
1801 and not Nkind_In (DeclO, N_Pragma,
1802 N_Use_Package_Clause,
1804 N_Implicit_Label_Declaration)
1807 ("this declaration not allowed in machine code subprogram",
1814 -- No statements other than code statements, pragmas, and labels.
1815 -- Again we allow certain internally generated statements.
1817 Stmt := First (Statements (HSS));
1818 while Present (Stmt) loop
1819 StmtO := Original_Node (Stmt);
1820 if Comes_From_Source (StmtO)
1821 and then not Nkind_In (StmtO, N_Pragma,
1826 ("this statement is not allowed in machine code subprogram",
1833 end Analyze_Code_Statement;
1835 -----------------------------------------------
1836 -- Analyze_Enumeration_Representation_Clause --
1837 -----------------------------------------------
1839 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
1840 Ident : constant Node_Id := Identifier (N);
1841 Aggr : constant Node_Id := Array_Aggregate (N);
1842 Enumtype : Entity_Id;
1848 Err : Boolean := False;
1850 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
1851 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
1856 if Ignore_Rep_Clauses then
1860 -- First some basic error checks
1863 Enumtype := Entity (Ident);
1865 if Enumtype = Any_Type
1866 or else Rep_Item_Too_Early (Enumtype, N)
1870 Enumtype := Underlying_Type (Enumtype);
1873 if not Is_Enumeration_Type (Enumtype) then
1875 ("enumeration type required, found}",
1876 Ident, First_Subtype (Enumtype));
1880 -- Ignore rep clause on generic actual type. This will already have
1881 -- been flagged on the template as an error, and this is the safest
1882 -- way to ensure we don't get a junk cascaded message in the instance.
1884 if Is_Generic_Actual_Type (Enumtype) then
1887 -- Type must be in current scope
1889 elsif Scope (Enumtype) /= Current_Scope then
1890 Error_Msg_N ("type must be declared in this scope", Ident);
1893 -- Type must be a first subtype
1895 elsif not Is_First_Subtype (Enumtype) then
1896 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
1899 -- Ignore duplicate rep clause
1901 elsif Has_Enumeration_Rep_Clause (Enumtype) then
1902 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
1905 -- Don't allow rep clause for standard [wide_[wide_]]character
1907 elsif Is_Standard_Character_Type (Enumtype) then
1908 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
1911 -- Check that the expression is a proper aggregate (no parentheses)
1913 elsif Paren_Count (Aggr) /= 0 then
1915 ("extra parentheses surrounding aggregate not allowed",
1919 -- All tests passed, so set rep clause in place
1922 Set_Has_Enumeration_Rep_Clause (Enumtype);
1923 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
1926 -- Now we process the aggregate. Note that we don't use the normal
1927 -- aggregate code for this purpose, because we don't want any of the
1928 -- normal expansion activities, and a number of special semantic
1929 -- rules apply (including the component type being any integer type)
1931 Elit := First_Literal (Enumtype);
1933 -- First the positional entries if any
1935 if Present (Expressions (Aggr)) then
1936 Expr := First (Expressions (Aggr));
1937 while Present (Expr) loop
1939 Error_Msg_N ("too many entries in aggregate", Expr);
1943 Val := Static_Integer (Expr);
1945 -- Err signals that we found some incorrect entries processing
1946 -- the list. The final checks for completeness and ordering are
1947 -- skipped in this case.
1949 if Val = No_Uint then
1951 elsif Val < Lo or else Hi < Val then
1952 Error_Msg_N ("value outside permitted range", Expr);
1956 Set_Enumeration_Rep (Elit, Val);
1957 Set_Enumeration_Rep_Expr (Elit, Expr);
1963 -- Now process the named entries if present
1965 if Present (Component_Associations (Aggr)) then
1966 Assoc := First (Component_Associations (Aggr));
1967 while Present (Assoc) loop
1968 Choice := First (Choices (Assoc));
1970 if Present (Next (Choice)) then
1972 ("multiple choice not allowed here", Next (Choice));
1976 if Nkind (Choice) = N_Others_Choice then
1977 Error_Msg_N ("others choice not allowed here", Choice);
1980 elsif Nkind (Choice) = N_Range then
1981 -- ??? should allow zero/one element range here
1982 Error_Msg_N ("range not allowed here", Choice);
1986 Analyze_And_Resolve (Choice, Enumtype);
1988 if Is_Entity_Name (Choice)
1989 and then Is_Type (Entity (Choice))
1991 Error_Msg_N ("subtype name not allowed here", Choice);
1993 -- ??? should allow static subtype with zero/one entry
1995 elsif Etype (Choice) = Base_Type (Enumtype) then
1996 if not Is_Static_Expression (Choice) then
1997 Flag_Non_Static_Expr
1998 ("non-static expression used for choice!", Choice);
2002 Elit := Expr_Value_E (Choice);
2004 if Present (Enumeration_Rep_Expr (Elit)) then
2005 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2007 ("representation for& previously given#",
2012 Set_Enumeration_Rep_Expr (Elit, Choice);
2014 Expr := Expression (Assoc);
2015 Val := Static_Integer (Expr);
2017 if Val = No_Uint then
2020 elsif Val < Lo or else Hi < Val then
2021 Error_Msg_N ("value outside permitted range", Expr);
2025 Set_Enumeration_Rep (Elit, Val);
2034 -- Aggregate is fully processed. Now we check that a full set of
2035 -- representations was given, and that they are in range and in order.
2036 -- These checks are only done if no other errors occurred.
2042 Elit := First_Literal (Enumtype);
2043 while Present (Elit) loop
2044 if No (Enumeration_Rep_Expr (Elit)) then
2045 Error_Msg_NE ("missing representation for&!", N, Elit);
2048 Val := Enumeration_Rep (Elit);
2050 if Min = No_Uint then
2054 if Val /= No_Uint then
2055 if Max /= No_Uint and then Val <= Max then
2057 ("enumeration value for& not ordered!",
2058 Enumeration_Rep_Expr (Elit), Elit);
2064 -- If there is at least one literal whose representation
2065 -- is not equal to the Pos value, then note that this
2066 -- enumeration type has a non-standard representation.
2068 if Val /= Enumeration_Pos (Elit) then
2069 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2076 -- Now set proper size information
2079 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2082 if Has_Size_Clause (Enumtype) then
2083 if Esize (Enumtype) >= Minsize then
2088 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2090 if Esize (Enumtype) < Minsize then
2091 Error_Msg_N ("previously given size is too small", N);
2094 Set_Has_Biased_Representation (Enumtype);
2099 Set_RM_Size (Enumtype, Minsize);
2100 Set_Enum_Esize (Enumtype);
2103 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2104 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2105 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2109 -- We repeat the too late test in case it froze itself!
2111 if Rep_Item_Too_Late (Enumtype, N) then
2114 end Analyze_Enumeration_Representation_Clause;
2116 ----------------------------
2117 -- Analyze_Free_Statement --
2118 ----------------------------
2120 procedure Analyze_Free_Statement (N : Node_Id) is
2122 Analyze (Expression (N));
2123 end Analyze_Free_Statement;
2125 ------------------------------------------
2126 -- Analyze_Record_Representation_Clause --
2127 ------------------------------------------
2129 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2130 Loc : constant Source_Ptr := Sloc (N);
2131 Ident : constant Node_Id := Identifier (N);
2132 Rectype : Entity_Id;
2138 Hbit : Uint := Uint_0;
2143 Max_Bit_So_Far : Uint;
2144 -- Records the maximum bit position so far. If all field positions
2145 -- are monotonically increasing, then we can skip the circuit for
2146 -- checking for overlap, since no overlap is possible.
2148 Overlap_Check_Required : Boolean;
2149 -- Used to keep track of whether or not an overlap check is required
2151 Ccount : Natural := 0;
2152 -- Number of component clauses in record rep clause
2154 CR_Pragma : Node_Id := Empty;
2155 -- Points to N_Pragma node if Complete_Representation pragma present
2158 if Ignore_Rep_Clauses then
2163 Rectype := Entity (Ident);
2165 if Rectype = Any_Type
2166 or else Rep_Item_Too_Early (Rectype, N)
2170 Rectype := Underlying_Type (Rectype);
2173 -- First some basic error checks
2175 if not Is_Record_Type (Rectype) then
2177 ("record type required, found}", Ident, First_Subtype (Rectype));
2180 elsif Is_Unchecked_Union (Rectype) then
2182 ("record rep clause not allowed for Unchecked_Union", N);
2184 elsif Scope (Rectype) /= Current_Scope then
2185 Error_Msg_N ("type must be declared in this scope", N);
2188 elsif not Is_First_Subtype (Rectype) then
2189 Error_Msg_N ("cannot give record rep clause for subtype", N);
2192 elsif Has_Record_Rep_Clause (Rectype) then
2193 Error_Msg_N ("duplicate record rep clause ignored", N);
2196 elsif Rep_Item_Too_Late (Rectype, N) then
2200 if Present (Mod_Clause (N)) then
2202 Loc : constant Source_Ptr := Sloc (N);
2203 M : constant Node_Id := Mod_Clause (N);
2204 P : constant List_Id := Pragmas_Before (M);
2208 pragma Warnings (Off, Mod_Val);
2211 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2213 if Warn_On_Obsolescent_Feature then
2215 ("mod clause is an obsolescent feature (RM J.8)?", N);
2217 ("\use alignment attribute definition clause instead?", N);
2224 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2225 -- the Mod clause into an alignment clause anyway, so that the
2226 -- back-end can compute and back-annotate properly the size and
2227 -- alignment of types that may include this record.
2229 -- This seems dubious, this destroys the source tree in a manner
2230 -- not detectable by ASIS ???
2232 if Operating_Mode = Check_Semantics
2236 Make_Attribute_Definition_Clause (Loc,
2237 Name => New_Reference_To (Base_Type (Rectype), Loc),
2238 Chars => Name_Alignment,
2239 Expression => Relocate_Node (Expression (M)));
2241 Set_From_At_Mod (AtM_Nod);
2242 Insert_After (N, AtM_Nod);
2243 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2244 Set_Mod_Clause (N, Empty);
2247 -- Get the alignment value to perform error checking
2249 Mod_Val := Get_Alignment_Value (Expression (M));
2255 -- For untagged types, clear any existing component clauses for the
2256 -- type. If the type is derived, this is what allows us to override
2257 -- a rep clause for the parent. For type extensions, the representation
2258 -- of the inherited components is inherited, so we want to keep previous
2259 -- component clauses for completeness.
2261 if not Is_Tagged_Type (Rectype) then
2262 Comp := First_Component_Or_Discriminant (Rectype);
2263 while Present (Comp) loop
2264 Set_Component_Clause (Comp, Empty);
2265 Next_Component_Or_Discriminant (Comp);
2269 -- All done if no component clauses
2271 CC := First (Component_Clauses (N));
2277 -- If a tag is present, then create a component clause that places it
2278 -- at the start of the record (otherwise gigi may place it after other
2279 -- fields that have rep clauses).
2281 Fent := First_Entity (Rectype);
2283 if Nkind (Fent) = N_Defining_Identifier
2284 and then Chars (Fent) = Name_uTag
2286 Set_Component_Bit_Offset (Fent, Uint_0);
2287 Set_Normalized_Position (Fent, Uint_0);
2288 Set_Normalized_First_Bit (Fent, Uint_0);
2289 Set_Normalized_Position_Max (Fent, Uint_0);
2290 Init_Esize (Fent, System_Address_Size);
2292 Set_Component_Clause (Fent,
2293 Make_Component_Clause (Loc,
2295 Make_Identifier (Loc,
2296 Chars => Name_uTag),
2299 Make_Integer_Literal (Loc,
2303 Make_Integer_Literal (Loc,
2307 Make_Integer_Literal (Loc,
2308 UI_From_Int (System_Address_Size))));
2310 Ccount := Ccount + 1;
2313 -- A representation like this applies to the base type
2315 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2316 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2317 Set_Has_Specified_Layout (Base_Type (Rectype));
2319 Max_Bit_So_Far := Uint_Minus_1;
2320 Overlap_Check_Required := False;
2322 -- Process the component clauses
2324 while Present (CC) loop
2328 if Nkind (CC) = N_Pragma then
2331 -- The only pragma of interest is Complete_Representation
2333 if Pragma_Name (CC) = Name_Complete_Representation then
2337 -- Processing for real component clause
2340 Ccount := Ccount + 1;
2341 Posit := Static_Integer (Position (CC));
2342 Fbit := Static_Integer (First_Bit (CC));
2343 Lbit := Static_Integer (Last_Bit (CC));
2346 and then Fbit /= No_Uint
2347 and then Lbit /= No_Uint
2351 ("position cannot be negative", Position (CC));
2355 ("first bit cannot be negative", First_Bit (CC));
2357 -- The Last_Bit specified in a component clause must not be
2358 -- less than the First_Bit minus one (RM-13.5.1(10)).
2360 elsif Lbit < Fbit - 1 then
2362 ("last bit cannot be less than first bit minus one",
2365 -- Values look OK, so find the corresponding record component
2366 -- Even though the syntax allows an attribute reference for
2367 -- implementation-defined components, GNAT does not allow the
2368 -- tag to get an explicit position.
2370 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2371 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2372 Error_Msg_N ("position of tag cannot be specified", CC);
2374 Error_Msg_N ("illegal component name", CC);
2378 Comp := First_Entity (Rectype);
2379 while Present (Comp) loop
2380 exit when Chars (Comp) = Chars (Component_Name (CC));
2386 -- Maybe component of base type that is absent from
2387 -- statically constrained first subtype.
2389 Comp := First_Entity (Base_Type (Rectype));
2390 while Present (Comp) loop
2391 exit when Chars (Comp) = Chars (Component_Name (CC));
2398 ("component clause is for non-existent field", CC);
2400 elsif Present (Component_Clause (Comp)) then
2402 -- Diagnose duplicate rep clause, or check consistency
2403 -- if this is an inherited component. In a double fault,
2404 -- there may be a duplicate inconsistent clause for an
2405 -- inherited component.
2407 if Scope (Original_Record_Component (Comp)) = Rectype
2408 or else Parent (Component_Clause (Comp)) = N
2410 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2411 Error_Msg_N ("component clause previously given#", CC);
2415 Rep1 : constant Node_Id := Component_Clause (Comp);
2417 if Intval (Position (Rep1)) /=
2418 Intval (Position (CC))
2419 or else Intval (First_Bit (Rep1)) /=
2420 Intval (First_Bit (CC))
2421 or else Intval (Last_Bit (Rep1)) /=
2422 Intval (Last_Bit (CC))
2424 Error_Msg_N ("component clause inconsistent "
2425 & "with representation of ancestor", CC);
2426 elsif Warn_On_Redundant_Constructs then
2427 Error_Msg_N ("?redundant component clause "
2428 & "for inherited component!", CC);
2434 -- Make reference for field in record rep clause and set
2435 -- appropriate entity field in the field identifier.
2438 (Comp, Component_Name (CC), Set_Ref => False);
2439 Set_Entity (Component_Name (CC), Comp);
2441 -- Update Fbit and Lbit to the actual bit number
2443 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2444 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2446 if Fbit <= Max_Bit_So_Far then
2447 Overlap_Check_Required := True;
2449 Max_Bit_So_Far := Lbit;
2452 if Has_Size_Clause (Rectype)
2453 and then Esize (Rectype) <= Lbit
2456 ("bit number out of range of specified size",
2459 Set_Component_Clause (Comp, CC);
2460 Set_Component_Bit_Offset (Comp, Fbit);
2461 Set_Esize (Comp, 1 + (Lbit - Fbit));
2462 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2463 Set_Normalized_Position (Comp, Fbit / SSU);
2465 Set_Normalized_Position_Max
2466 (Fent, Normalized_Position (Fent));
2468 if Is_Tagged_Type (Rectype)
2469 and then Fbit < System_Address_Size
2472 ("component overlaps tag field of&",
2476 -- This information is also set in the corresponding
2477 -- component of the base type, found by accessing the
2478 -- Original_Record_Component link if it is present.
2480 Ocomp := Original_Record_Component (Comp);
2487 (Component_Name (CC),
2492 Set_Has_Biased_Representation (Comp, Biased);
2494 if Present (Ocomp) then
2495 Set_Component_Clause (Ocomp, CC);
2496 Set_Component_Bit_Offset (Ocomp, Fbit);
2497 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2498 Set_Normalized_Position (Ocomp, Fbit / SSU);
2499 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2501 Set_Normalized_Position_Max
2502 (Ocomp, Normalized_Position (Ocomp));
2504 Set_Has_Biased_Representation
2505 (Ocomp, Has_Biased_Representation (Comp));
2508 if Esize (Comp) < 0 then
2509 Error_Msg_N ("component size is negative", CC);
2520 -- Now that we have processed all the component clauses, check for
2521 -- overlap. We have to leave this till last, since the components can
2522 -- appear in any arbitrary order in the representation clause.
2524 -- We do not need this check if all specified ranges were monotonic,
2525 -- as recorded by Overlap_Check_Required being False at this stage.
2527 -- This first section checks if there are any overlapping entries at
2528 -- all. It does this by sorting all entries and then seeing if there are
2529 -- any overlaps. If there are none, then that is decisive, but if there
2530 -- are overlaps, they may still be OK (they may result from fields in
2531 -- different variants).
2533 if Overlap_Check_Required then
2534 Overlap_Check1 : declare
2536 OC_Fbit : array (0 .. Ccount) of Uint;
2537 -- First-bit values for component clauses, the value is the offset
2538 -- of the first bit of the field from start of record. The zero
2539 -- entry is for use in sorting.
2541 OC_Lbit : array (0 .. Ccount) of Uint;
2542 -- Last-bit values for component clauses, the value is the offset
2543 -- of the last bit of the field from start of record. The zero
2544 -- entry is for use in sorting.
2546 OC_Count : Natural := 0;
2547 -- Count of entries in OC_Fbit and OC_Lbit
2549 function OC_Lt (Op1, Op2 : Natural) return Boolean;
2550 -- Compare routine for Sort
2552 procedure OC_Move (From : Natural; To : Natural);
2553 -- Move routine for Sort
2555 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
2557 function OC_Lt (Op1, Op2 : Natural) return Boolean is
2559 return OC_Fbit (Op1) < OC_Fbit (Op2);
2562 procedure OC_Move (From : Natural; To : Natural) is
2564 OC_Fbit (To) := OC_Fbit (From);
2565 OC_Lbit (To) := OC_Lbit (From);
2569 CC := First (Component_Clauses (N));
2570 while Present (CC) loop
2571 if Nkind (CC) /= N_Pragma then
2572 Posit := Static_Integer (Position (CC));
2573 Fbit := Static_Integer (First_Bit (CC));
2574 Lbit := Static_Integer (Last_Bit (CC));
2577 and then Fbit /= No_Uint
2578 and then Lbit /= No_Uint
2580 OC_Count := OC_Count + 1;
2581 Posit := Posit * SSU;
2582 OC_Fbit (OC_Count) := Fbit + Posit;
2583 OC_Lbit (OC_Count) := Lbit + Posit;
2590 Sorting.Sort (OC_Count);
2592 Overlap_Check_Required := False;
2593 for J in 1 .. OC_Count - 1 loop
2594 if OC_Lbit (J) >= OC_Fbit (J + 1) then
2595 Overlap_Check_Required := True;
2602 -- If Overlap_Check_Required is still True, then we have to do the full
2603 -- scale overlap check, since we have at least two fields that do
2604 -- overlap, and we need to know if that is OK since they are in
2605 -- different variant, or whether we have a definite problem.
2607 if Overlap_Check_Required then
2608 Overlap_Check2 : declare
2609 C1_Ent, C2_Ent : Entity_Id;
2610 -- Entities of components being checked for overlap
2613 -- Component_List node whose Component_Items are being checked
2616 -- Component declaration for component being checked
2619 C1_Ent := First_Entity (Base_Type (Rectype));
2621 -- Loop through all components in record. For each component check
2622 -- for overlap with any of the preceding elements on the component
2623 -- list containing the component and also, if the component is in
2624 -- a variant, check against components outside the case structure.
2625 -- This latter test is repeated recursively up the variant tree.
2627 Main_Component_Loop : while Present (C1_Ent) loop
2628 if Ekind (C1_Ent) /= E_Component
2629 and then Ekind (C1_Ent) /= E_Discriminant
2631 goto Continue_Main_Component_Loop;
2634 -- Skip overlap check if entity has no declaration node. This
2635 -- happens with discriminants in constrained derived types.
2636 -- Probably we are missing some checks as a result, but that
2637 -- does not seem terribly serious ???
2639 if No (Declaration_Node (C1_Ent)) then
2640 goto Continue_Main_Component_Loop;
2643 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
2645 -- Loop through component lists that need checking. Check the
2646 -- current component list and all lists in variants above us.
2648 Component_List_Loop : loop
2650 -- If derived type definition, go to full declaration
2651 -- If at outer level, check discriminants if there are any.
2653 if Nkind (Clist) = N_Derived_Type_Definition then
2654 Clist := Parent (Clist);
2657 -- Outer level of record definition, check discriminants
2659 if Nkind_In (Clist, N_Full_Type_Declaration,
2660 N_Private_Type_Declaration)
2662 if Has_Discriminants (Defining_Identifier (Clist)) then
2664 First_Discriminant (Defining_Identifier (Clist));
2666 while Present (C2_Ent) loop
2667 exit when C1_Ent = C2_Ent;
2668 Check_Component_Overlap (C1_Ent, C2_Ent);
2669 Next_Discriminant (C2_Ent);
2673 -- Record extension case
2675 elsif Nkind (Clist) = N_Derived_Type_Definition then
2678 -- Otherwise check one component list
2681 Citem := First (Component_Items (Clist));
2683 while Present (Citem) loop
2684 if Nkind (Citem) = N_Component_Declaration then
2685 C2_Ent := Defining_Identifier (Citem);
2686 exit when C1_Ent = C2_Ent;
2687 Check_Component_Overlap (C1_Ent, C2_Ent);
2694 -- Check for variants above us (the parent of the Clist can
2695 -- be a variant, in which case its parent is a variant part,
2696 -- and the parent of the variant part is a component list
2697 -- whose components must all be checked against the current
2698 -- component for overlap).
2700 if Nkind (Parent (Clist)) = N_Variant then
2701 Clist := Parent (Parent (Parent (Clist)));
2703 -- Check for possible discriminant part in record, this is
2704 -- treated essentially as another level in the recursion.
2705 -- For this case the parent of the component list is the
2706 -- record definition, and its parent is the full type
2707 -- declaration containing the discriminant specifications.
2709 elsif Nkind (Parent (Clist)) = N_Record_Definition then
2710 Clist := Parent (Parent ((Clist)));
2712 -- If neither of these two cases, we are at the top of
2716 exit Component_List_Loop;
2718 end loop Component_List_Loop;
2720 <<Continue_Main_Component_Loop>>
2721 Next_Entity (C1_Ent);
2723 end loop Main_Component_Loop;
2727 -- For records that have component clauses for all components, and whose
2728 -- size is less than or equal to 32, we need to know the size in the
2729 -- front end to activate possible packed array processing where the
2730 -- component type is a record.
2732 -- At this stage Hbit + 1 represents the first unused bit from all the
2733 -- component clauses processed, so if the component clauses are
2734 -- complete, then this is the length of the record.
2736 -- For records longer than System.Storage_Unit, and for those where not
2737 -- all components have component clauses, the back end determines the
2738 -- length (it may for example be appropriate to round up the size
2739 -- to some convenient boundary, based on alignment considerations, etc).
2741 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
2743 -- Nothing to do if at least one component has no component clause
2745 Comp := First_Component_Or_Discriminant (Rectype);
2746 while Present (Comp) loop
2747 exit when No (Component_Clause (Comp));
2748 Next_Component_Or_Discriminant (Comp);
2751 -- If we fall out of loop, all components have component clauses
2752 -- and so we can set the size to the maximum value.
2755 Set_RM_Size (Rectype, Hbit + 1);
2759 -- Check missing components if Complete_Representation pragma appeared
2761 if Present (CR_Pragma) then
2762 Comp := First_Component_Or_Discriminant (Rectype);
2763 while Present (Comp) loop
2764 if No (Component_Clause (Comp)) then
2766 ("missing component clause for &", CR_Pragma, Comp);
2769 Next_Component_Or_Discriminant (Comp);
2772 -- If no Complete_Representation pragma, warn if missing components
2774 elsif Warn_On_Unrepped_Components then
2776 Num_Repped_Components : Nat := 0;
2777 Num_Unrepped_Components : Nat := 0;
2780 -- First count number of repped and unrepped components
2782 Comp := First_Component_Or_Discriminant (Rectype);
2783 while Present (Comp) loop
2784 if Present (Component_Clause (Comp)) then
2785 Num_Repped_Components := Num_Repped_Components + 1;
2787 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2790 Next_Component_Or_Discriminant (Comp);
2793 -- We are only interested in the case where there is at least one
2794 -- unrepped component, and at least half the components have rep
2795 -- clauses. We figure that if less than half have them, then the
2796 -- partial rep clause is really intentional. If the component
2797 -- type has no underlying type set at this point (as for a generic
2798 -- formal type), we don't know enough to give a warning on the
2801 if Num_Unrepped_Components > 0
2802 and then Num_Unrepped_Components < Num_Repped_Components
2804 Comp := First_Component_Or_Discriminant (Rectype);
2805 while Present (Comp) loop
2806 if No (Component_Clause (Comp))
2807 and then Comes_From_Source (Comp)
2808 and then Present (Underlying_Type (Etype (Comp)))
2809 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2810 or else Size_Known_At_Compile_Time
2811 (Underlying_Type (Etype (Comp))))
2812 and then not Has_Warnings_Off (Rectype)
2814 Error_Msg_Sloc := Sloc (Comp);
2816 ("?no component clause given for & declared #",
2820 Next_Component_Or_Discriminant (Comp);
2825 end Analyze_Record_Representation_Clause;
2827 -----------------------------
2828 -- Check_Component_Overlap --
2829 -----------------------------
2831 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
2833 if Present (Component_Clause (C1_Ent))
2834 and then Present (Component_Clause (C2_Ent))
2836 -- Exclude odd case where we have two tag fields in the same record,
2837 -- both at location zero. This seems a bit strange, but it seems to
2838 -- happen in some circumstances ???
2840 if Chars (C1_Ent) = Name_uTag
2841 and then Chars (C2_Ent) = Name_uTag
2846 -- Here we check if the two fields overlap
2849 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
2850 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
2851 E1 : constant Uint := S1 + Esize (C1_Ent);
2852 E2 : constant Uint := S2 + Esize (C2_Ent);
2855 if E2 <= S1 or else E1 <= S2 then
2859 Component_Name (Component_Clause (C2_Ent));
2860 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
2862 Component_Name (Component_Clause (C1_Ent));
2864 ("component& overlaps & #",
2865 Component_Name (Component_Clause (C1_Ent)));
2869 end Check_Component_Overlap;
2871 -----------------------------------
2872 -- Check_Constant_Address_Clause --
2873 -----------------------------------
2875 procedure Check_Constant_Address_Clause
2879 procedure Check_At_Constant_Address (Nod : Node_Id);
2880 -- Checks that the given node N represents a name whose 'Address is
2881 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2882 -- address value is the same at the point of declaration of U_Ent and at
2883 -- the time of elaboration of the address clause.
2885 procedure Check_Expr_Constants (Nod : Node_Id);
2886 -- Checks that Nod meets the requirements for a constant address clause
2887 -- in the sense of the enclosing procedure.
2889 procedure Check_List_Constants (Lst : List_Id);
2890 -- Check that all elements of list Lst meet the requirements for a
2891 -- constant address clause in the sense of the enclosing procedure.
2893 -------------------------------
2894 -- Check_At_Constant_Address --
2895 -------------------------------
2897 procedure Check_At_Constant_Address (Nod : Node_Id) is
2899 if Is_Entity_Name (Nod) then
2900 if Present (Address_Clause (Entity ((Nod)))) then
2902 ("invalid address clause for initialized object &!",
2905 ("address for& cannot" &
2906 " depend on another address clause! (RM 13.1(22))!",
2909 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2910 and then Sloc (U_Ent) < Sloc (Entity (Nod))
2913 ("invalid address clause for initialized object &!",
2915 Error_Msg_Name_1 := Chars (Entity (Nod));
2916 Error_Msg_Name_2 := Chars (U_Ent);
2918 ("\% must be defined before % (RM 13.1(22))!",
2922 elsif Nkind (Nod) = N_Selected_Component then
2924 T : constant Entity_Id := Etype (Prefix (Nod));
2927 if (Is_Record_Type (T)
2928 and then Has_Discriminants (T))
2931 and then Is_Record_Type (Designated_Type (T))
2932 and then Has_Discriminants (Designated_Type (T)))
2935 ("invalid address clause for initialized object &!",
2938 ("\address cannot depend on component" &
2939 " of discriminated record (RM 13.1(22))!",
2942 Check_At_Constant_Address (Prefix (Nod));
2946 elsif Nkind (Nod) = N_Indexed_Component then
2947 Check_At_Constant_Address (Prefix (Nod));
2948 Check_List_Constants (Expressions (Nod));
2951 Check_Expr_Constants (Nod);
2953 end Check_At_Constant_Address;
2955 --------------------------
2956 -- Check_Expr_Constants --
2957 --------------------------
2959 procedure Check_Expr_Constants (Nod : Node_Id) is
2960 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
2961 Ent : Entity_Id := Empty;
2964 if Nkind (Nod) in N_Has_Etype
2965 and then Etype (Nod) = Any_Type
2971 when N_Empty | N_Error =>
2974 when N_Identifier | N_Expanded_Name =>
2975 Ent := Entity (Nod);
2977 -- We need to look at the original node if it is different
2978 -- from the node, since we may have rewritten things and
2979 -- substituted an identifier representing the rewrite.
2981 if Original_Node (Nod) /= Nod then
2982 Check_Expr_Constants (Original_Node (Nod));
2984 -- If the node is an object declaration without initial
2985 -- value, some code has been expanded, and the expression
2986 -- is not constant, even if the constituents might be
2987 -- acceptable, as in A'Address + offset.
2989 if Ekind (Ent) = E_Variable
2991 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
2993 No (Expression (Declaration_Node (Ent)))
2996 ("invalid address clause for initialized object &!",
2999 -- If entity is constant, it may be the result of expanding
3000 -- a check. We must verify that its declaration appears
3001 -- before the object in question, else we also reject the
3004 elsif Ekind (Ent) = E_Constant
3005 and then In_Same_Source_Unit (Ent, U_Ent)
3006 and then Sloc (Ent) > Loc_U_Ent
3009 ("invalid address clause for initialized object &!",
3016 -- Otherwise look at the identifier and see if it is OK
3018 if Ekind (Ent) = E_Named_Integer
3020 Ekind (Ent) = E_Named_Real
3027 Ekind (Ent) = E_Constant
3029 Ekind (Ent) = E_In_Parameter
3031 -- This is the case where we must have Ent defined before
3032 -- U_Ent. Clearly if they are in different units this
3033 -- requirement is met since the unit containing Ent is
3034 -- already processed.
3036 if not In_Same_Source_Unit (Ent, U_Ent) then
3039 -- Otherwise location of Ent must be before the location
3040 -- of U_Ent, that's what prior defined means.
3042 elsif Sloc (Ent) < Loc_U_Ent then
3047 ("invalid address clause for initialized object &!",
3049 Error_Msg_Name_1 := Chars (Ent);
3050 Error_Msg_Name_2 := Chars (U_Ent);
3052 ("\% must be defined before % (RM 13.1(22))!",
3056 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3057 Check_Expr_Constants (Original_Node (Nod));
3061 ("invalid address clause for initialized object &!",
3064 if Comes_From_Source (Ent) then
3065 Error_Msg_Name_1 := Chars (Ent);
3067 ("\reference to variable% not allowed"
3068 & " (RM 13.1(22))!", Nod);
3071 ("non-static expression not allowed"
3072 & " (RM 13.1(22))!", Nod);
3076 when N_Integer_Literal =>
3078 -- If this is a rewritten unchecked conversion, in a system
3079 -- where Address is an integer type, always use the base type
3080 -- for a literal value. This is user-friendly and prevents
3081 -- order-of-elaboration issues with instances of unchecked
3084 if Nkind (Original_Node (Nod)) = N_Function_Call then
3085 Set_Etype (Nod, Base_Type (Etype (Nod)));
3088 when N_Real_Literal |
3090 N_Character_Literal =>
3094 Check_Expr_Constants (Low_Bound (Nod));
3095 Check_Expr_Constants (High_Bound (Nod));
3097 when N_Explicit_Dereference =>
3098 Check_Expr_Constants (Prefix (Nod));
3100 when N_Indexed_Component =>
3101 Check_Expr_Constants (Prefix (Nod));
3102 Check_List_Constants (Expressions (Nod));
3105 Check_Expr_Constants (Prefix (Nod));
3106 Check_Expr_Constants (Discrete_Range (Nod));
3108 when N_Selected_Component =>
3109 Check_Expr_Constants (Prefix (Nod));
3111 when N_Attribute_Reference =>
3112 if Attribute_Name (Nod) = Name_Address
3114 Attribute_Name (Nod) = Name_Access
3116 Attribute_Name (Nod) = Name_Unchecked_Access
3118 Attribute_Name (Nod) = Name_Unrestricted_Access
3120 Check_At_Constant_Address (Prefix (Nod));
3123 Check_Expr_Constants (Prefix (Nod));
3124 Check_List_Constants (Expressions (Nod));
3128 Check_List_Constants (Component_Associations (Nod));
3129 Check_List_Constants (Expressions (Nod));
3131 when N_Component_Association =>
3132 Check_Expr_Constants (Expression (Nod));
3134 when N_Extension_Aggregate =>
3135 Check_Expr_Constants (Ancestor_Part (Nod));
3136 Check_List_Constants (Component_Associations (Nod));
3137 Check_List_Constants (Expressions (Nod));
3142 when N_Binary_Op | N_And_Then | N_Or_Else | N_Membership_Test =>
3143 Check_Expr_Constants (Left_Opnd (Nod));
3144 Check_Expr_Constants (Right_Opnd (Nod));
3147 Check_Expr_Constants (Right_Opnd (Nod));
3149 when N_Type_Conversion |
3150 N_Qualified_Expression |
3152 Check_Expr_Constants (Expression (Nod));
3154 when N_Unchecked_Type_Conversion =>
3155 Check_Expr_Constants (Expression (Nod));
3157 -- If this is a rewritten unchecked conversion, subtypes in
3158 -- this node are those created within the instance. To avoid
3159 -- order of elaboration issues, replace them with their base
3160 -- types. Note that address clauses can cause order of
3161 -- elaboration problems because they are elaborated by the
3162 -- back-end at the point of definition, and may mention
3163 -- entities declared in between (as long as everything is
3164 -- static). It is user-friendly to allow unchecked conversions
3167 if Nkind (Original_Node (Nod)) = N_Function_Call then
3168 Set_Etype (Expression (Nod),
3169 Base_Type (Etype (Expression (Nod))));
3170 Set_Etype (Nod, Base_Type (Etype (Nod)));
3173 when N_Function_Call =>
3174 if not Is_Pure (Entity (Name (Nod))) then
3176 ("invalid address clause for initialized object &!",
3180 ("\function & is not pure (RM 13.1(22))!",
3181 Nod, Entity (Name (Nod)));
3184 Check_List_Constants (Parameter_Associations (Nod));
3187 when N_Parameter_Association =>
3188 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3192 ("invalid address clause for initialized object &!",
3195 ("\must be constant defined before& (RM 13.1(22))!",
3198 end Check_Expr_Constants;
3200 --------------------------
3201 -- Check_List_Constants --
3202 --------------------------
3204 procedure Check_List_Constants (Lst : List_Id) is
3208 if Present (Lst) then
3209 Nod1 := First (Lst);
3210 while Present (Nod1) loop
3211 Check_Expr_Constants (Nod1);
3215 end Check_List_Constants;
3217 -- Start of processing for Check_Constant_Address_Clause
3220 Check_Expr_Constants (Expr);
3221 end Check_Constant_Address_Clause;
3227 procedure Check_Size
3231 Biased : out Boolean)
3233 UT : constant Entity_Id := Underlying_Type (T);
3239 -- Dismiss cases for generic types or types with previous errors
3242 or else UT = Any_Type
3243 or else Is_Generic_Type (UT)
3244 or else Is_Generic_Type (Root_Type (UT))
3248 -- Check case of bit packed array
3250 elsif Is_Array_Type (UT)
3251 and then Known_Static_Component_Size (UT)
3252 and then Is_Bit_Packed_Array (UT)
3260 Asiz := Component_Size (UT);
3261 Indx := First_Index (UT);
3263 Ityp := Etype (Indx);
3265 -- If non-static bound, then we are not in the business of
3266 -- trying to check the length, and indeed an error will be
3267 -- issued elsewhere, since sizes of non-static array types
3268 -- cannot be set implicitly or explicitly.
3270 if not Is_Static_Subtype (Ityp) then
3274 -- Otherwise accumulate next dimension
3276 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
3277 Expr_Value (Type_Low_Bound (Ityp)) +
3281 exit when No (Indx);
3287 Error_Msg_Uint_1 := Asiz;
3289 ("size for& too small, minimum allowed is ^", N, T);
3290 Set_Esize (T, Asiz);
3291 Set_RM_Size (T, Asiz);
3295 -- All other composite types are ignored
3297 elsif Is_Composite_Type (UT) then
3300 -- For fixed-point types, don't check minimum if type is not frozen,
3301 -- since we don't know all the characteristics of the type that can
3302 -- affect the size (e.g. a specified small) till freeze time.
3304 elsif Is_Fixed_Point_Type (UT)
3305 and then not Is_Frozen (UT)
3309 -- Cases for which a minimum check is required
3312 -- Ignore if specified size is correct for the type
3314 if Known_Esize (UT) and then Siz = Esize (UT) then
3318 -- Otherwise get minimum size
3320 M := UI_From_Int (Minimum_Size (UT));
3324 -- Size is less than minimum size, but one possibility remains
3325 -- that we can manage with the new size if we bias the type.
3327 M := UI_From_Int (Minimum_Size (UT, Biased => True));
3330 Error_Msg_Uint_1 := M;
3332 ("size for& too small, minimum allowed is ^", N, T);
3342 -------------------------
3343 -- Get_Alignment_Value --
3344 -------------------------
3346 function Get_Alignment_Value (Expr : Node_Id) return Uint is
3347 Align : constant Uint := Static_Integer (Expr);
3350 if Align = No_Uint then
3353 elsif Align <= 0 then
3354 Error_Msg_N ("alignment value must be positive", Expr);
3358 for J in Int range 0 .. 64 loop
3360 M : constant Uint := Uint_2 ** J;
3363 exit when M = Align;
3367 ("alignment value must be power of 2", Expr);
3375 end Get_Alignment_Value;
3381 procedure Initialize is
3383 Unchecked_Conversions.Init;
3386 -------------------------
3387 -- Is_Operational_Item --
3388 -------------------------
3390 function Is_Operational_Item (N : Node_Id) return Boolean is
3392 if Nkind (N) /= N_Attribute_Definition_Clause then
3396 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
3398 return Id = Attribute_Input
3399 or else Id = Attribute_Output
3400 or else Id = Attribute_Read
3401 or else Id = Attribute_Write
3402 or else Id = Attribute_External_Tag;
3405 end Is_Operational_Item;
3411 function Minimum_Size
3413 Biased : Boolean := False) return Nat
3415 Lo : Uint := No_Uint;
3416 Hi : Uint := No_Uint;
3417 LoR : Ureal := No_Ureal;
3418 HiR : Ureal := No_Ureal;
3419 LoSet : Boolean := False;
3420 HiSet : Boolean := False;
3424 R_Typ : constant Entity_Id := Root_Type (T);
3427 -- If bad type, return 0
3429 if T = Any_Type then
3432 -- For generic types, just return zero. There cannot be any legitimate
3433 -- need to know such a size, but this routine may be called with a
3434 -- generic type as part of normal processing.
3436 elsif Is_Generic_Type (R_Typ)
3437 or else R_Typ = Any_Type
3441 -- Access types. Normally an access type cannot have a size smaller
3442 -- than the size of System.Address. The exception is on VMS, where
3443 -- we have short and long addresses, and it is possible for an access
3444 -- type to have a short address size (and thus be less than the size
3445 -- of System.Address itself). We simply skip the check for VMS, and
3446 -- leave it to the back end to do the check.
3448 elsif Is_Access_Type (T) then
3449 if OpenVMS_On_Target then
3452 return System_Address_Size;
3455 -- Floating-point types
3457 elsif Is_Floating_Point_Type (T) then
3458 return UI_To_Int (Esize (R_Typ));
3462 elsif Is_Discrete_Type (T) then
3464 -- The following loop is looking for the nearest compile time known
3465 -- bounds following the ancestor subtype chain. The idea is to find
3466 -- the most restrictive known bounds information.
3470 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3475 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
3476 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
3483 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
3484 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
3490 Ancest := Ancestor_Subtype (Ancest);
3493 Ancest := Base_Type (T);
3495 if Is_Generic_Type (Ancest) then
3501 -- Fixed-point types. We can't simply use Expr_Value to get the
3502 -- Corresponding_Integer_Value values of the bounds, since these do not
3503 -- get set till the type is frozen, and this routine can be called
3504 -- before the type is frozen. Similarly the test for bounds being static
3505 -- needs to include the case where we have unanalyzed real literals for
3508 elsif Is_Fixed_Point_Type (T) then
3510 -- The following loop is looking for the nearest compile time known
3511 -- bounds following the ancestor subtype chain. The idea is to find
3512 -- the most restrictive known bounds information.
3516 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3520 -- Note: In the following two tests for LoSet and HiSet, it may
3521 -- seem redundant to test for N_Real_Literal here since normally
3522 -- one would assume that the test for the value being known at
3523 -- compile time includes this case. However, there is a glitch.
3524 -- If the real literal comes from folding a non-static expression,
3525 -- then we don't consider any non- static expression to be known
3526 -- at compile time if we are in configurable run time mode (needed
3527 -- in some cases to give a clearer definition of what is and what
3528 -- is not accepted). So the test is indeed needed. Without it, we
3529 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
3532 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
3533 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
3535 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
3542 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
3543 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
3545 HiR := Expr_Value_R (Type_High_Bound (Ancest));
3551 Ancest := Ancestor_Subtype (Ancest);
3554 Ancest := Base_Type (T);
3556 if Is_Generic_Type (Ancest) then
3562 Lo := UR_To_Uint (LoR / Small_Value (T));
3563 Hi := UR_To_Uint (HiR / Small_Value (T));
3565 -- No other types allowed
3568 raise Program_Error;
3571 -- Fall through with Hi and Lo set. Deal with biased case
3573 if (Biased and then not Is_Fixed_Point_Type (T))
3574 or else Has_Biased_Representation (T)
3580 -- Signed case. Note that we consider types like range 1 .. -1 to be
3581 -- signed for the purpose of computing the size, since the bounds have
3582 -- to be accommodated in the base type.
3584 if Lo < 0 or else Hi < 0 then
3588 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
3589 -- Note that we accommodate the case where the bounds cross. This
3590 -- can happen either because of the way the bounds are declared
3591 -- or because of the algorithm in Freeze_Fixed_Point_Type.
3605 -- If both bounds are positive, make sure that both are represen-
3606 -- table in the case where the bounds are crossed. This can happen
3607 -- either because of the way the bounds are declared, or because of
3608 -- the algorithm in Freeze_Fixed_Point_Type.
3614 -- S = size, (can accommodate 0 .. (2**size - 1))
3617 while Hi >= Uint_2 ** S loop
3625 ---------------------------
3626 -- New_Stream_Subprogram --
3627 ---------------------------
3629 procedure New_Stream_Subprogram
3633 Nam : TSS_Name_Type)
3635 Loc : constant Source_Ptr := Sloc (N);
3636 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
3637 Subp_Id : Entity_Id;
3638 Subp_Decl : Node_Id;
3642 Defer_Declaration : constant Boolean :=
3643 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
3644 -- For a tagged type, there is a declaration for each stream attribute
3645 -- at the freeze point, and we must generate only a completion of this
3646 -- declaration. We do the same for private types, because the full view
3647 -- might be tagged. Otherwise we generate a declaration at the point of
3648 -- the attribute definition clause.
3650 function Build_Spec return Node_Id;
3651 -- Used for declaration and renaming declaration, so that this is
3652 -- treated as a renaming_as_body.
3658 function Build_Spec return Node_Id is
3659 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
3662 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
3665 Subp_Id := Make_Defining_Identifier (Loc, Sname);
3667 -- S : access Root_Stream_Type'Class
3669 Formals := New_List (
3670 Make_Parameter_Specification (Loc,
3671 Defining_Identifier =>
3672 Make_Defining_Identifier (Loc, Name_S),
3674 Make_Access_Definition (Loc,
3677 Designated_Type (Etype (F)), Loc))));
3679 if Nam = TSS_Stream_Input then
3680 Spec := Make_Function_Specification (Loc,
3681 Defining_Unit_Name => Subp_Id,
3682 Parameter_Specifications => Formals,
3683 Result_Definition => T_Ref);
3688 Make_Parameter_Specification (Loc,
3689 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
3690 Out_Present => Out_P,
3691 Parameter_Type => T_Ref));
3693 Spec := Make_Procedure_Specification (Loc,
3694 Defining_Unit_Name => Subp_Id,
3695 Parameter_Specifications => Formals);
3701 -- Start of processing for New_Stream_Subprogram
3704 F := First_Formal (Subp);
3706 if Ekind (Subp) = E_Procedure then
3707 Etyp := Etype (Next_Formal (F));
3709 Etyp := Etype (Subp);
3712 -- Prepare subprogram declaration and insert it as an action on the
3713 -- clause node. The visibility for this entity is used to test for
3714 -- visibility of the attribute definition clause (in the sense of
3715 -- 8.3(23) as amended by AI-195).
3717 if not Defer_Declaration then
3719 Make_Subprogram_Declaration (Loc,
3720 Specification => Build_Spec);
3722 -- For a tagged type, there is always a visible declaration for each
3723 -- stream TSS (it is a predefined primitive operation), and the
3724 -- completion of this declaration occurs at the freeze point, which is
3725 -- not always visible at places where the attribute definition clause is
3726 -- visible. So, we create a dummy entity here for the purpose of
3727 -- tracking the visibility of the attribute definition clause itself.
3731 Make_Defining_Identifier (Loc,
3732 Chars => New_External_Name (Sname, 'V'));
3734 Make_Object_Declaration (Loc,
3735 Defining_Identifier => Subp_Id,
3736 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
3739 Insert_Action (N, Subp_Decl);
3740 Set_Entity (N, Subp_Id);
3743 Make_Subprogram_Renaming_Declaration (Loc,
3744 Specification => Build_Spec,
3745 Name => New_Reference_To (Subp, Loc));
3747 if Defer_Declaration then
3748 Set_TSS (Base_Type (Ent), Subp_Id);
3750 Insert_Action (N, Subp_Decl);
3751 Copy_TSS (Subp_Id, Base_Type (Ent));
3753 end New_Stream_Subprogram;
3755 ------------------------
3756 -- Rep_Item_Too_Early --
3757 ------------------------
3759 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
3761 -- Cannot apply non-operational rep items to generic types
3763 if Is_Operational_Item (N) then
3767 and then Is_Generic_Type (Root_Type (T))
3770 ("representation item not allowed for generic type", N);
3774 -- Otherwise check for incomplete type
3776 if Is_Incomplete_Or_Private_Type (T)
3777 and then No (Underlying_Type (T))
3780 ("representation item must be after full type declaration", N);
3783 -- If the type has incomplete components, a representation clause is
3784 -- illegal but stream attributes and Convention pragmas are correct.
3786 elsif Has_Private_Component (T) then
3787 if Nkind (N) = N_Pragma then
3791 ("representation item must appear after type is fully defined",
3798 end Rep_Item_Too_Early;
3800 -----------------------
3801 -- Rep_Item_Too_Late --
3802 -----------------------
3804 function Rep_Item_Too_Late
3807 FOnly : Boolean := False) return Boolean
3810 Parent_Type : Entity_Id;
3813 -- Output the too late message. Note that this is not considered a
3814 -- serious error, since the effect is simply that we ignore the
3815 -- representation clause in this case.
3821 procedure Too_Late is
3823 Error_Msg_N ("|representation item appears too late!", N);
3826 -- Start of processing for Rep_Item_Too_Late
3829 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
3830 -- types, which may be frozen if they appear in a representation clause
3831 -- for a local type.
3834 and then not From_With_Type (T)
3837 S := First_Subtype (T);
3839 if Present (Freeze_Node (S)) then
3841 ("?no more representation items for }", Freeze_Node (S), S);
3846 -- Check for case of non-tagged derived type whose parent either has
3847 -- primitive operations, or is a by reference type (RM 13.1(10)).
3851 and then Is_Derived_Type (T)
3852 and then not Is_Tagged_Type (T)
3854 Parent_Type := Etype (Base_Type (T));
3856 if Has_Primitive_Operations (Parent_Type) then
3859 ("primitive operations already defined for&!", N, Parent_Type);
3862 elsif Is_By_Reference_Type (Parent_Type) then
3865 ("parent type & is a by reference type!", N, Parent_Type);
3870 -- No error, link item into head of chain of rep items for the entity,
3871 -- but avoid chaining if we have an overloadable entity, and the pragma
3872 -- is one that can apply to multiple overloaded entities.
3874 if Is_Overloadable (T)
3875 and then Nkind (N) = N_Pragma
3878 Pname : constant Name_Id := Pragma_Name (N);
3880 if Pname = Name_Convention or else
3881 Pname = Name_Import or else
3882 Pname = Name_Export or else
3883 Pname = Name_External or else
3884 Pname = Name_Interface
3891 Record_Rep_Item (T, N);
3893 end Rep_Item_Too_Late;
3895 -------------------------
3896 -- Same_Representation --
3897 -------------------------
3899 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
3900 T1 : constant Entity_Id := Underlying_Type (Typ1);
3901 T2 : constant Entity_Id := Underlying_Type (Typ2);
3904 -- A quick check, if base types are the same, then we definitely have
3905 -- the same representation, because the subtype specific representation
3906 -- attributes (Size and Alignment) do not affect representation from
3907 -- the point of view of this test.
3909 if Base_Type (T1) = Base_Type (T2) then
3912 elsif Is_Private_Type (Base_Type (T2))
3913 and then Base_Type (T1) = Full_View (Base_Type (T2))
3918 -- Tagged types never have differing representations
3920 if Is_Tagged_Type (T1) then
3924 -- Representations are definitely different if conventions differ
3926 if Convention (T1) /= Convention (T2) then
3930 -- Representations are different if component alignments differ
3932 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
3934 (Is_Record_Type (T2) or else Is_Array_Type (T2))
3935 and then Component_Alignment (T1) /= Component_Alignment (T2)
3940 -- For arrays, the only real issue is component size. If we know the
3941 -- component size for both arrays, and it is the same, then that's
3942 -- good enough to know we don't have a change of representation.
3944 if Is_Array_Type (T1) then
3945 if Known_Component_Size (T1)
3946 and then Known_Component_Size (T2)
3947 and then Component_Size (T1) = Component_Size (T2)
3953 -- Types definitely have same representation if neither has non-standard
3954 -- representation since default representations are always consistent.
3955 -- If only one has non-standard representation, and the other does not,
3956 -- then we consider that they do not have the same representation. They
3957 -- might, but there is no way of telling early enough.
3959 if Has_Non_Standard_Rep (T1) then
3960 if not Has_Non_Standard_Rep (T2) then
3964 return not Has_Non_Standard_Rep (T2);
3967 -- Here the two types both have non-standard representation, and we need
3968 -- to determine if they have the same non-standard representation.
3970 -- For arrays, we simply need to test if the component sizes are the
3971 -- same. Pragma Pack is reflected in modified component sizes, so this
3972 -- check also deals with pragma Pack.
3974 if Is_Array_Type (T1) then
3975 return Component_Size (T1) = Component_Size (T2);
3977 -- Tagged types always have the same representation, because it is not
3978 -- possible to specify different representations for common fields.
3980 elsif Is_Tagged_Type (T1) then
3983 -- Case of record types
3985 elsif Is_Record_Type (T1) then
3987 -- Packed status must conform
3989 if Is_Packed (T1) /= Is_Packed (T2) then
3992 -- Otherwise we must check components. Typ2 maybe a constrained
3993 -- subtype with fewer components, so we compare the components
3994 -- of the base types.
3997 Record_Case : declare
3998 CD1, CD2 : Entity_Id;
4000 function Same_Rep return Boolean;
4001 -- CD1 and CD2 are either components or discriminants. This
4002 -- function tests whether the two have the same representation
4008 function Same_Rep return Boolean is
4010 if No (Component_Clause (CD1)) then
4011 return No (Component_Clause (CD2));
4015 Present (Component_Clause (CD2))
4017 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4019 Esize (CD1) = Esize (CD2);
4023 -- Start processing for Record_Case
4026 if Has_Discriminants (T1) then
4027 CD1 := First_Discriminant (T1);
4028 CD2 := First_Discriminant (T2);
4030 -- The number of discriminants may be different if the
4031 -- derived type has fewer (constrained by values). The
4032 -- invisible discriminants retain the representation of
4033 -- the original, so the discrepancy does not per se
4034 -- indicate a different representation.
4037 and then Present (CD2)
4039 if not Same_Rep then
4042 Next_Discriminant (CD1);
4043 Next_Discriminant (CD2);
4048 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4049 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4051 while Present (CD1) loop
4052 if not Same_Rep then
4055 Next_Component (CD1);
4056 Next_Component (CD2);
4064 -- For enumeration types, we must check each literal to see if the
4065 -- representation is the same. Note that we do not permit enumeration
4066 -- representation clauses for Character and Wide_Character, so these
4067 -- cases were already dealt with.
4069 elsif Is_Enumeration_Type (T1) then
4071 Enumeration_Case : declare
4075 L1 := First_Literal (T1);
4076 L2 := First_Literal (T2);
4078 while Present (L1) loop
4079 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4089 end Enumeration_Case;
4091 -- Any other types have the same representation for these purposes
4096 end Same_Representation;
4098 --------------------
4099 -- Set_Enum_Esize --
4100 --------------------
4102 procedure Set_Enum_Esize (T : Entity_Id) is
4110 -- Find the minimum standard size (8,16,32,64) that fits
4112 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4113 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4116 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4117 Sz := Standard_Character_Size; -- May be > 8 on some targets
4119 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4122 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4125 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4130 if Hi < Uint_2**08 then
4131 Sz := Standard_Character_Size; -- May be > 8 on some targets
4133 elsif Hi < Uint_2**16 then
4136 elsif Hi < Uint_2**32 then
4139 else pragma Assert (Hi < Uint_2**63);
4144 -- That minimum is the proper size unless we have a foreign convention
4145 -- and the size required is 32 or less, in which case we bump the size
4146 -- up to 32. This is required for C and C++ and seems reasonable for
4147 -- all other foreign conventions.
4149 if Has_Foreign_Convention (T)
4150 and then Esize (T) < Standard_Integer_Size
4152 Init_Esize (T, Standard_Integer_Size);
4158 ------------------------------
4159 -- Validate_Address_Clauses --
4160 ------------------------------
4162 procedure Validate_Address_Clauses is
4164 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4166 ACCR : Address_Clause_Check_Record
4167 renames Address_Clause_Checks.Table (J);
4176 -- Skip processing of this entry if warning already posted
4178 if not Address_Warning_Posted (ACCR.N) then
4180 -- Get alignments. Really we should always have the alignment
4181 -- of the objects properly back annotated, but right now the
4182 -- back end fails to back annotate for address clauses???
4184 if Known_Alignment (ACCR.X) then
4185 X_Alignment := Alignment (ACCR.X);
4187 X_Alignment := Alignment (Etype (ACCR.X));
4190 if Known_Alignment (ACCR.Y) then
4191 Y_Alignment := Alignment (ACCR.Y);
4193 Y_Alignment := Alignment (Etype (ACCR.Y));
4196 -- Similarly obtain sizes
4198 if Known_Esize (ACCR.X) then
4199 X_Size := Esize (ACCR.X);
4201 X_Size := Esize (Etype (ACCR.X));
4204 if Known_Esize (ACCR.Y) then
4205 Y_Size := Esize (ACCR.Y);
4207 Y_Size := Esize (Etype (ACCR.Y));
4210 -- Check for large object overlaying smaller one
4213 and then X_Size > Uint_0
4214 and then X_Size > Y_Size
4217 ("?size for overlaid object is too small", ACCR.N);
4218 Error_Msg_Uint_1 := X_Size;
4220 ("\?size of & is ^", ACCR.N, ACCR.X);
4221 Error_Msg_Uint_1 := Y_Size;
4223 ("\?size of & is ^", ACCR.N, ACCR.Y);
4225 -- Check for inadequate alignment. Again the defensive check
4226 -- on Y_Alignment should not be needed, but because of the
4227 -- failure in back end annotation, we can have an alignment
4230 -- Note: we do not check alignments if we gave a size
4231 -- warning, since it would likely be redundant.
4233 elsif Y_Alignment /= Uint_0
4234 and then Y_Alignment < X_Alignment
4237 ("?specified address for& may be inconsistent "
4241 ("\?program execution may be erroneous (RM 13.3(27))",
4243 Error_Msg_Uint_1 := X_Alignment;
4245 ("\?alignment of & is ^",
4247 Error_Msg_Uint_1 := Y_Alignment;
4249 ("\?alignment of & is ^",
4255 end Validate_Address_Clauses;
4257 -----------------------------------
4258 -- Validate_Unchecked_Conversion --
4259 -----------------------------------
4261 procedure Validate_Unchecked_Conversion
4263 Act_Unit : Entity_Id)
4270 -- Obtain source and target types. Note that we call Ancestor_Subtype
4271 -- here because the processing for generic instantiation always makes
4272 -- subtypes, and we want the original frozen actual types.
4274 -- If we are dealing with private types, then do the check on their
4275 -- fully declared counterparts if the full declarations have been
4276 -- encountered (they don't have to be visible, but they must exist!)
4278 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
4280 if Is_Private_Type (Source)
4281 and then Present (Underlying_Type (Source))
4283 Source := Underlying_Type (Source);
4286 Target := Ancestor_Subtype (Etype (Act_Unit));
4288 -- If either type is generic, the instantiation happens within a generic
4289 -- unit, and there is nothing to check. The proper check
4290 -- will happen when the enclosing generic is instantiated.
4292 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
4296 if Is_Private_Type (Target)
4297 and then Present (Underlying_Type (Target))
4299 Target := Underlying_Type (Target);
4302 -- Source may be unconstrained array, but not target
4304 if Is_Array_Type (Target)
4305 and then not Is_Constrained (Target)
4308 ("unchecked conversion to unconstrained array not allowed", N);
4312 -- Warn if conversion between two different convention pointers
4314 if Is_Access_Type (Target)
4315 and then Is_Access_Type (Source)
4316 and then Convention (Target) /= Convention (Source)
4317 and then Warn_On_Unchecked_Conversion
4319 -- Give warnings for subprogram pointers only on most targets. The
4320 -- exception is VMS, where data pointers can have different lengths
4321 -- depending on the pointer convention.
4323 if Is_Access_Subprogram_Type (Target)
4324 or else Is_Access_Subprogram_Type (Source)
4325 or else OpenVMS_On_Target
4328 ("?conversion between pointers with different conventions!", N);
4332 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4333 -- warning when compiling GNAT-related sources.
4335 if Warn_On_Unchecked_Conversion
4336 and then not In_Predefined_Unit (N)
4337 and then RTU_Loaded (Ada_Calendar)
4339 (Chars (Source) = Name_Time
4341 Chars (Target) = Name_Time)
4343 -- If Ada.Calendar is loaded and the name of one of the operands is
4344 -- Time, there is a good chance that this is Ada.Calendar.Time.
4347 Calendar_Time : constant Entity_Id :=
4348 Full_View (RTE (RO_CA_Time));
4350 pragma Assert (Present (Calendar_Time));
4352 if Source = Calendar_Time
4353 or else Target = Calendar_Time
4356 ("?representation of 'Time values may change between " &
4357 "'G'N'A'T versions", N);
4362 -- Make entry in unchecked conversion table for later processing by
4363 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4364 -- (using values set by the back-end where possible). This is only done
4365 -- if the appropriate warning is active.
4367 if Warn_On_Unchecked_Conversion then
4368 Unchecked_Conversions.Append
4369 (New_Val => UC_Entry'
4374 -- If both sizes are known statically now, then back end annotation
4375 -- is not required to do a proper check but if either size is not
4376 -- known statically, then we need the annotation.
4378 if Known_Static_RM_Size (Source)
4379 and then Known_Static_RM_Size (Target)
4383 Back_Annotate_Rep_Info := True;
4387 -- If unchecked conversion to access type, and access type is declared
4388 -- in the same unit as the unchecked conversion, then set the
4389 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4392 if Is_Access_Type (Target) and then
4393 In_Same_Source_Unit (Target, N)
4395 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4398 -- Generate N_Validate_Unchecked_Conversion node for back end in
4399 -- case the back end needs to perform special validation checks.
4401 -- Shouldn't this be in Exp_Ch13, since the check only gets done
4402 -- if we have full expansion and the back end is called ???
4405 Make_Validate_Unchecked_Conversion (Sloc (N));
4406 Set_Source_Type (Vnode, Source);
4407 Set_Target_Type (Vnode, Target);
4409 -- If the unchecked conversion node is in a list, just insert before it.
4410 -- If not we have some strange case, not worth bothering about.
4412 if Is_List_Member (N) then
4413 Insert_After (N, Vnode);
4415 end Validate_Unchecked_Conversion;
4417 ------------------------------------
4418 -- Validate_Unchecked_Conversions --
4419 ------------------------------------
4421 procedure Validate_Unchecked_Conversions is
4423 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4425 T : UC_Entry renames Unchecked_Conversions.Table (N);
4427 Enode : constant Node_Id := T.Enode;
4428 Source : constant Entity_Id := T.Source;
4429 Target : constant Entity_Id := T.Target;
4435 -- This validation check, which warns if we have unequal sizes for
4436 -- unchecked conversion, and thus potentially implementation
4437 -- dependent semantics, is one of the few occasions on which we
4438 -- use the official RM size instead of Esize. See description in
4439 -- Einfo "Handling of Type'Size Values" for details.
4441 if Serious_Errors_Detected = 0
4442 and then Known_Static_RM_Size (Source)
4443 and then Known_Static_RM_Size (Target)
4445 Source_Siz := RM_Size (Source);
4446 Target_Siz := RM_Size (Target);
4448 if Source_Siz /= Target_Siz then
4450 ("?types for unchecked conversion have different sizes!",
4453 if All_Errors_Mode then
4454 Error_Msg_Name_1 := Chars (Source);
4455 Error_Msg_Uint_1 := Source_Siz;
4456 Error_Msg_Name_2 := Chars (Target);
4457 Error_Msg_Uint_2 := Target_Siz;
4459 ("\size of % is ^, size of % is ^?", Enode);
4461 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4463 if Is_Discrete_Type (Source)
4464 and then Is_Discrete_Type (Target)
4466 if Source_Siz > Target_Siz then
4468 ("\?^ high order bits of source will be ignored!",
4471 elsif Is_Unsigned_Type (Source) then
4473 ("\?source will be extended with ^ high order " &
4474 "zero bits?!", Enode);
4478 ("\?source will be extended with ^ high order " &
4483 elsif Source_Siz < Target_Siz then
4484 if Is_Discrete_Type (Target) then
4485 if Bytes_Big_Endian then
4487 ("\?target value will include ^ undefined " &
4492 ("\?target value will include ^ undefined " &
4499 ("\?^ trailing bits of target value will be " &
4500 "undefined!", Enode);
4503 else pragma Assert (Source_Siz > Target_Siz);
4505 ("\?^ trailing bits of source will be ignored!",
4512 -- If both types are access types, we need to check the alignment.
4513 -- If the alignment of both is specified, we can do it here.
4515 if Serious_Errors_Detected = 0
4516 and then Ekind (Source) in Access_Kind
4517 and then Ekind (Target) in Access_Kind
4518 and then Target_Strict_Alignment
4519 and then Present (Designated_Type (Source))
4520 and then Present (Designated_Type (Target))
4523 D_Source : constant Entity_Id := Designated_Type (Source);
4524 D_Target : constant Entity_Id := Designated_Type (Target);
4527 if Known_Alignment (D_Source)
4528 and then Known_Alignment (D_Target)
4531 Source_Align : constant Uint := Alignment (D_Source);
4532 Target_Align : constant Uint := Alignment (D_Target);
4535 if Source_Align < Target_Align
4536 and then not Is_Tagged_Type (D_Source)
4538 Error_Msg_Uint_1 := Target_Align;
4539 Error_Msg_Uint_2 := Source_Align;
4540 Error_Msg_Node_2 := D_Source;
4542 ("?alignment of & (^) is stricter than " &
4543 "alignment of & (^)!", Enode, D_Target);
4545 if All_Errors_Mode then
4547 ("\?resulting access value may have invalid " &
4548 "alignment!", Enode);
4557 end Validate_Unchecked_Conversions;