1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Atree; use Atree;
27 with Checks; use Checks;
28 with Einfo; use Einfo;
29 with Errout; use Errout;
30 with Exp_Tss; use Exp_Tss;
31 with Exp_Util; use Exp_Util;
33 with Lib.Xref; use Lib.Xref;
34 with Namet; use Namet;
35 with Nlists; use Nlists;
36 with Nmake; use Nmake;
38 with Restrict; use Restrict;
39 with Rident; use Rident;
40 with Rtsfind; use Rtsfind;
42 with Sem_Aux; use Sem_Aux;
43 with Sem_Ch8; use Sem_Ch8;
44 with Sem_Eval; use Sem_Eval;
45 with Sem_Res; use Sem_Res;
46 with Sem_Type; use Sem_Type;
47 with Sem_Util; use Sem_Util;
48 with Sem_Warn; use Sem_Warn;
49 with Snames; use Snames;
50 with Stand; use Stand;
51 with Sinfo; use Sinfo;
53 with Targparm; use Targparm;
54 with Ttypes; use Ttypes;
55 with Tbuild; use Tbuild;
56 with Urealp; use Urealp;
58 with GNAT.Heap_Sort_G;
60 package body Sem_Ch13 is
62 SSU : constant Pos := System_Storage_Unit;
63 -- Convenient short hand for commonly used constant
65 -----------------------
66 -- Local Subprograms --
67 -----------------------
69 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
70 -- This routine is called after setting the Esize of type entity Typ.
71 -- The purpose is to deal with the situation where an alignment has been
72 -- inherited from a derived type that is no longer appropriate for the
73 -- new Esize value. In this case, we reset the Alignment to unknown.
75 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
76 -- Given two entities for record components or discriminants, checks
77 -- if they have overlapping component clauses and issues errors if so.
79 function Get_Alignment_Value (Expr : Node_Id) return Uint;
80 -- Given the expression for an alignment value, returns the corresponding
81 -- Uint value. If the value is inappropriate, then error messages are
82 -- posted as required, and a value of No_Uint is returned.
84 function Is_Operational_Item (N : Node_Id) return Boolean;
85 -- A specification for a stream attribute is allowed before the full
86 -- type is declared, as explained in AI-00137 and the corrigendum.
87 -- Attributes that do not specify a representation characteristic are
88 -- operational attributes.
90 procedure New_Stream_Subprogram
95 -- Create a subprogram renaming of a given stream attribute to the
96 -- designated subprogram and then in the tagged case, provide this as a
97 -- primitive operation, or in the non-tagged case make an appropriate TSS
98 -- entry. This is more properly an expansion activity than just semantics,
99 -- but the presence of user-defined stream functions for limited types is a
100 -- legality check, which is why this takes place here rather than in
101 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
102 -- function to be generated.
104 -- To avoid elaboration anomalies with freeze nodes, for untagged types
105 -- we generate both a subprogram declaration and a subprogram renaming
106 -- declaration, so that the attribute specification is handled as a
107 -- renaming_as_body. For tagged types, the specification is one of the
110 ----------------------------------------------
111 -- Table for Validate_Unchecked_Conversions --
112 ----------------------------------------------
114 -- The following table collects unchecked conversions for validation.
115 -- Entries are made by Validate_Unchecked_Conversion and then the
116 -- call to Validate_Unchecked_Conversions does the actual error
117 -- checking and posting of warnings. The reason for this delayed
118 -- processing is to take advantage of back-annotations of size and
119 -- alignment values performed by the back end.
121 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
122 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
123 -- will already have modified all Sloc values if the -gnatD option is set.
125 type UC_Entry is record
126 Eloc : Source_Ptr; -- node used for posting warnings
127 Source : Entity_Id; -- source type for unchecked conversion
128 Target : Entity_Id; -- target type for unchecked conversion
131 package Unchecked_Conversions is new Table.Table (
132 Table_Component_Type => UC_Entry,
133 Table_Index_Type => Int,
134 Table_Low_Bound => 1,
136 Table_Increment => 200,
137 Table_Name => "Unchecked_Conversions");
139 ----------------------------------------
140 -- Table for Validate_Address_Clauses --
141 ----------------------------------------
143 -- If an address clause has the form
145 -- for X'Address use Expr
147 -- where Expr is of the form Y'Address or recursively is a reference
148 -- to a constant of either of these forms, and X and Y are entities of
149 -- objects, then if Y has a smaller alignment than X, that merits a
150 -- warning about possible bad alignment. The following table collects
151 -- address clauses of this kind. We put these in a table so that they
152 -- can be checked after the back end has completed annotation of the
153 -- alignments of objects, since we can catch more cases that way.
155 type Address_Clause_Check_Record is record
157 -- The address clause
160 -- The entity of the object overlaying Y
163 -- The entity of the object being overlaid
166 -- Whether the address is offseted within Y
169 package Address_Clause_Checks is new Table.Table (
170 Table_Component_Type => Address_Clause_Check_Record,
171 Table_Index_Type => Int,
172 Table_Low_Bound => 1,
174 Table_Increment => 200,
175 Table_Name => "Address_Clause_Checks");
177 -----------------------------------------
178 -- Adjust_Record_For_Reverse_Bit_Order --
179 -----------------------------------------
181 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
182 Max_Machine_Scalar_Size : constant Uint :=
184 (Standard_Long_Long_Integer_Size);
185 -- We use this as the maximum machine scalar size in the sense of AI-133
189 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
192 -- This first loop through components does two things. First it deals
193 -- with the case of components with component clauses whose length is
194 -- greater than the maximum machine scalar size (either accepting them
195 -- or rejecting as needed). Second, it counts the number of components
196 -- with component clauses whose length does not exceed this maximum for
200 Comp := First_Component_Or_Discriminant (R);
201 while Present (Comp) loop
203 CC : constant Node_Id := Component_Clause (Comp);
208 Fbit : constant Uint := Static_Integer (First_Bit (CC));
211 -- Case of component with size > max machine scalar
213 if Esize (Comp) > Max_Machine_Scalar_Size then
215 -- Must begin on byte boundary
217 if Fbit mod SSU /= 0 then
219 ("illegal first bit value for reverse bit order",
221 Error_Msg_Uint_1 := SSU;
222 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
225 ("\must be a multiple of ^ if size greater than ^",
228 -- Must end on byte boundary
230 elsif Esize (Comp) mod SSU /= 0 then
232 ("illegal last bit value for reverse bit order",
234 Error_Msg_Uint_1 := SSU;
235 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
238 ("\must be a multiple of ^ if size greater than ^",
241 -- OK, give warning if enabled
243 elsif Warn_On_Reverse_Bit_Order then
245 ("multi-byte field specified with non-standard"
246 & " Bit_Order?", CC);
248 if Bytes_Big_Endian then
250 ("\bytes are not reversed "
251 & "(component is big-endian)?", CC);
254 ("\bytes are not reversed "
255 & "(component is little-endian)?", CC);
259 -- Case where size is not greater than max machine
260 -- scalar. For now, we just count these.
263 Num_CC := Num_CC + 1;
269 Next_Component_Or_Discriminant (Comp);
272 -- We need to sort the component clauses on the basis of the Position
273 -- values in the clause, so we can group clauses with the same Position.
274 -- together to determine the relevant machine scalar size.
277 Comps : array (0 .. Num_CC) of Entity_Id;
278 -- Array to collect component and discriminant entities. The data
279 -- starts at index 1, the 0'th entry is for the sort routine.
281 function CP_Lt (Op1, Op2 : Natural) return Boolean;
282 -- Compare routine for Sort
284 procedure CP_Move (From : Natural; To : Natural);
285 -- Move routine for Sort
287 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
291 -- Start and stop positions in component list of set of components
292 -- with the same starting position (that constitute components in
293 -- a single machine scalar).
296 -- Maximum last bit value of any component in this set
299 -- Corresponding machine scalar size
305 function CP_Lt (Op1, Op2 : Natural) return Boolean is
307 return Position (Component_Clause (Comps (Op1))) <
308 Position (Component_Clause (Comps (Op2)));
315 procedure CP_Move (From : Natural; To : Natural) is
317 Comps (To) := Comps (From);
321 -- Collect the component clauses
324 Comp := First_Component_Or_Discriminant (R);
325 while Present (Comp) loop
326 if Present (Component_Clause (Comp))
327 and then Esize (Comp) <= Max_Machine_Scalar_Size
329 Num_CC := Num_CC + 1;
330 Comps (Num_CC) := Comp;
333 Next_Component_Or_Discriminant (Comp);
336 -- Sort by ascending position number
338 Sorting.Sort (Num_CC);
340 -- We now have all the components whose size does not exceed the max
341 -- machine scalar value, sorted by starting position. In this loop
342 -- we gather groups of clauses starting at the same position, to
343 -- process them in accordance with Ada 2005 AI-133.
346 while Stop < Num_CC loop
350 Static_Integer (Last_Bit (Component_Clause (Comps (Start))));
351 while Stop < Num_CC loop
353 (Position (Component_Clause (Comps (Stop + 1)))) =
355 (Position (Component_Clause (Comps (Stop))))
362 (Last_Bit (Component_Clause (Comps (Stop)))));
368 -- Now we have a group of component clauses from Start to Stop
369 -- whose positions are identical, and MaxL is the maximum last bit
370 -- value of any of these components.
372 -- We need to determine the corresponding machine scalar size.
373 -- This loop assumes that machine scalar sizes are even, and that
374 -- each possible machine scalar has twice as many bits as the
377 MSS := Max_Machine_Scalar_Size;
379 and then (MSS / 2) >= SSU
380 and then (MSS / 2) > MaxL
385 -- Here is where we fix up the Component_Bit_Offset value to
386 -- account for the reverse bit order. Some examples of what needs
387 -- to be done for the case of a machine scalar size of 8 are:
389 -- First_Bit .. Last_Bit Component_Bit_Offset
401 -- The general rule is that the first bit is obtained by
402 -- subtracting the old ending bit from machine scalar size - 1.
404 for C in Start .. Stop loop
406 Comp : constant Entity_Id := Comps (C);
407 CC : constant Node_Id := Component_Clause (Comp);
408 LB : constant Uint := Static_Integer (Last_Bit (CC));
409 NFB : constant Uint := MSS - Uint_1 - LB;
410 NLB : constant Uint := NFB + Esize (Comp) - 1;
411 Pos : constant Uint := Static_Integer (Position (CC));
414 if Warn_On_Reverse_Bit_Order then
415 Error_Msg_Uint_1 := MSS;
417 ("info: reverse bit order in machine " &
418 "scalar of length^?", First_Bit (CC));
419 Error_Msg_Uint_1 := NFB;
420 Error_Msg_Uint_2 := NLB;
422 if Bytes_Big_Endian then
424 ("?\info: big-endian range for "
425 & "component & is ^ .. ^",
426 First_Bit (CC), Comp);
429 ("?\info: little-endian range "
430 & "for component & is ^ .. ^",
431 First_Bit (CC), Comp);
435 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
436 Set_Normalized_First_Bit (Comp, NFB mod SSU);
441 end Adjust_Record_For_Reverse_Bit_Order;
443 --------------------------------------
444 -- Alignment_Check_For_Esize_Change --
445 --------------------------------------
447 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
449 -- If the alignment is known, and not set by a rep clause, and is
450 -- inconsistent with the size being set, then reset it to unknown,
451 -- we assume in this case that the size overrides the inherited
452 -- alignment, and that the alignment must be recomputed.
454 if Known_Alignment (Typ)
455 and then not Has_Alignment_Clause (Typ)
456 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
458 Init_Alignment (Typ);
460 end Alignment_Check_For_Esize_Change;
462 -----------------------
463 -- Analyze_At_Clause --
464 -----------------------
466 -- An at clause is replaced by the corresponding Address attribute
467 -- definition clause that is the preferred approach in Ada 95.
469 procedure Analyze_At_Clause (N : Node_Id) is
470 CS : constant Boolean := Comes_From_Source (N);
473 -- This is an obsolescent feature
475 Check_Restriction (No_Obsolescent_Features, N);
477 if Warn_On_Obsolescent_Feature then
479 ("at clause is an obsolescent feature (RM J.7(2))?", N);
481 ("\use address attribute definition clause instead?", N);
484 -- Rewrite as address clause
487 Make_Attribute_Definition_Clause (Sloc (N),
488 Name => Identifier (N),
489 Chars => Name_Address,
490 Expression => Expression (N)));
492 -- We preserve Comes_From_Source, since logically the clause still
493 -- comes from the source program even though it is changed in form.
495 Set_Comes_From_Source (N, CS);
497 -- Analyze rewritten clause
499 Analyze_Attribute_Definition_Clause (N);
500 end Analyze_At_Clause;
502 -----------------------------------------
503 -- Analyze_Attribute_Definition_Clause --
504 -----------------------------------------
506 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
507 Loc : constant Source_Ptr := Sloc (N);
508 Nam : constant Node_Id := Name (N);
509 Attr : constant Name_Id := Chars (N);
510 Expr : constant Node_Id := Expression (N);
511 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
515 FOnly : Boolean := False;
516 -- Reset to True for subtype specific attribute (Alignment, Size)
517 -- and for stream attributes, i.e. those cases where in the call
518 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
519 -- rules are checked. Note that the case of stream attributes is not
520 -- clear from the RM, but see AI95-00137. Also, the RM seems to
521 -- disallow Storage_Size for derived task types, but that is also
522 -- clearly unintentional.
524 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
525 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
526 -- definition clauses.
528 -----------------------------------
529 -- Analyze_Stream_TSS_Definition --
530 -----------------------------------
532 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
533 Subp : Entity_Id := Empty;
538 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
540 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
541 -- Return true if the entity is a subprogram with an appropriate
542 -- profile for the attribute being defined.
544 ----------------------
545 -- Has_Good_Profile --
546 ----------------------
548 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
550 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
551 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
552 (False => E_Procedure, True => E_Function);
556 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
560 F := First_Formal (Subp);
563 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
564 or else Designated_Type (Etype (F)) /=
565 Class_Wide_Type (RTE (RE_Root_Stream_Type))
570 if not Is_Function then
574 Expected_Mode : constant array (Boolean) of Entity_Kind :=
575 (False => E_In_Parameter,
576 True => E_Out_Parameter);
578 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
589 return Base_Type (Typ) = Base_Type (Ent)
590 and then No (Next_Formal (F));
591 end Has_Good_Profile;
593 -- Start of processing for Analyze_Stream_TSS_Definition
598 if not Is_Type (U_Ent) then
599 Error_Msg_N ("local name must be a subtype", Nam);
603 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
605 -- If Pnam is present, it can be either inherited from an ancestor
606 -- type (in which case it is legal to redefine it for this type), or
607 -- be a previous definition of the attribute for the same type (in
608 -- which case it is illegal).
610 -- In the first case, it will have been analyzed already, and we
611 -- can check that its profile does not match the expected profile
612 -- for a stream attribute of U_Ent. In the second case, either Pnam
613 -- has been analyzed (and has the expected profile), or it has not
614 -- been analyzed yet (case of a type that has not been frozen yet
615 -- and for which the stream attribute has been set using Set_TSS).
618 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
620 Error_Msg_Sloc := Sloc (Pnam);
621 Error_Msg_Name_1 := Attr;
622 Error_Msg_N ("% attribute already defined #", Nam);
628 if Is_Entity_Name (Expr) then
629 if not Is_Overloaded (Expr) then
630 if Has_Good_Profile (Entity (Expr)) then
631 Subp := Entity (Expr);
635 Get_First_Interp (Expr, I, It);
636 while Present (It.Nam) loop
637 if Has_Good_Profile (It.Nam) then
642 Get_Next_Interp (I, It);
647 if Present (Subp) then
648 if Is_Abstract_Subprogram (Subp) then
649 Error_Msg_N ("stream subprogram must not be abstract", Expr);
653 Set_Entity (Expr, Subp);
654 Set_Etype (Expr, Etype (Subp));
656 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
659 Error_Msg_Name_1 := Attr;
660 Error_Msg_N ("incorrect expression for% attribute", Expr);
662 end Analyze_Stream_TSS_Definition;
664 -- Start of processing for Analyze_Attribute_Definition_Clause
667 -- Process Ignore_Rep_Clauses option
669 if Ignore_Rep_Clauses then
672 -- The following should be ignored. They do not affect legality
673 -- and may be target dependent. The basic idea of -gnatI is to
674 -- ignore any rep clauses that may be target dependent but do not
675 -- affect legality (except possibly to be rejected because they
676 -- are incompatible with the compilation target).
678 when Attribute_Address |
679 Attribute_Alignment |
680 Attribute_Bit_Order |
681 Attribute_Component_Size |
682 Attribute_Machine_Radix |
683 Attribute_Object_Size |
686 Attribute_Stream_Size |
687 Attribute_Value_Size =>
689 Rewrite (N, Make_Null_Statement (Sloc (N)));
692 -- The following should not be ignored, because in the first place
693 -- they are reasonably portable, and should not cause problems in
694 -- compiling code from another target, and also they do affect
695 -- legality, e.g. failing to provide a stream attribute for a
696 -- type may make a program illegal.
698 when Attribute_External_Tag |
702 Attribute_Storage_Pool |
703 Attribute_Storage_Size |
707 -- Other cases are errors, which will be caught below
717 if Rep_Item_Too_Early (Ent, N) then
721 -- Rep clause applies to full view of incomplete type or private type if
722 -- we have one (if not, this is a premature use of the type). However,
723 -- certain semantic checks need to be done on the specified entity (i.e.
724 -- the private view), so we save it in Ent.
726 if Is_Private_Type (Ent)
727 and then Is_Derived_Type (Ent)
728 and then not Is_Tagged_Type (Ent)
729 and then No (Full_View (Ent))
731 -- If this is a private type whose completion is a derivation from
732 -- another private type, there is no full view, and the attribute
733 -- belongs to the type itself, not its underlying parent.
737 elsif Ekind (Ent) = E_Incomplete_Type then
739 -- The attribute applies to the full view, set the entity of the
740 -- attribute definition accordingly.
742 Ent := Underlying_Type (Ent);
744 Set_Entity (Nam, Ent);
747 U_Ent := Underlying_Type (Ent);
750 -- Complete other routine error checks
752 if Etype (Nam) = Any_Type then
755 elsif Scope (Ent) /= Current_Scope then
756 Error_Msg_N ("entity must be declared in this scope", Nam);
759 elsif No (U_Ent) then
762 elsif Is_Type (U_Ent)
763 and then not Is_First_Subtype (U_Ent)
764 and then Id /= Attribute_Object_Size
765 and then Id /= Attribute_Value_Size
766 and then not From_At_Mod (N)
768 Error_Msg_N ("cannot specify attribute for subtype", Nam);
772 -- Switch on particular attribute
780 -- Address attribute definition clause
782 when Attribute_Address => Address : begin
784 -- A little error check, catch for X'Address use X'Address;
786 if Nkind (Nam) = N_Identifier
787 and then Nkind (Expr) = N_Attribute_Reference
788 and then Attribute_Name (Expr) = Name_Address
789 and then Nkind (Prefix (Expr)) = N_Identifier
790 and then Chars (Nam) = Chars (Prefix (Expr))
793 ("address for & is self-referencing", Prefix (Expr), Ent);
797 -- Not that special case, carry on with analysis of expression
799 Analyze_And_Resolve (Expr, RTE (RE_Address));
801 if Present (Address_Clause (U_Ent)) then
802 Error_Msg_N ("address already given for &", Nam);
804 -- Case of address clause for subprogram
806 elsif Is_Subprogram (U_Ent) then
807 if Has_Homonym (U_Ent) then
809 ("address clause cannot be given " &
810 "for overloaded subprogram",
815 -- For subprograms, all address clauses are permitted, and we
816 -- mark the subprogram as having a deferred freeze so that Gigi
817 -- will not elaborate it too soon.
819 -- Above needs more comments, what is too soon about???
821 Set_Has_Delayed_Freeze (U_Ent);
823 -- Case of address clause for entry
825 elsif Ekind (U_Ent) = E_Entry then
826 if Nkind (Parent (N)) = N_Task_Body then
828 ("entry address must be specified in task spec", Nam);
832 -- For entries, we require a constant address
834 Check_Constant_Address_Clause (Expr, U_Ent);
836 -- Special checks for task types
838 if Is_Task_Type (Scope (U_Ent))
839 and then Comes_From_Source (Scope (U_Ent))
842 ("?entry address declared for entry in task type", N);
844 ("\?only one task can be declared of this type", N);
847 -- Entry address clauses are obsolescent
849 Check_Restriction (No_Obsolescent_Features, N);
851 if Warn_On_Obsolescent_Feature then
853 ("attaching interrupt to task entry is an " &
854 "obsolescent feature (RM J.7.1)?", N);
856 ("\use interrupt procedure instead?", N);
859 -- Case of an address clause for a controlled object which we
860 -- consider to be erroneous.
862 elsif Is_Controlled (Etype (U_Ent))
863 or else Has_Controlled_Component (Etype (U_Ent))
866 ("?controlled object& must not be overlaid", Nam, U_Ent);
868 ("\?Program_Error will be raised at run time", Nam);
869 Insert_Action (Declaration_Node (U_Ent),
870 Make_Raise_Program_Error (Loc,
871 Reason => PE_Overlaid_Controlled_Object));
874 -- Case of address clause for a (non-controlled) object
877 Ekind (U_Ent) = E_Variable
879 Ekind (U_Ent) = E_Constant
882 Expr : constant Node_Id := Expression (N);
888 -- Exported variables cannot have an address clause,
889 -- because this cancels the effect of the pragma Export
891 if Is_Exported (U_Ent) then
893 ("cannot export object with address clause", Nam);
897 Find_Overlaid_Entity (N, O_Ent, Off);
899 -- Overlaying controlled objects is erroneous
902 and then (Has_Controlled_Component (Etype (O_Ent))
903 or else Is_Controlled (Etype (O_Ent)))
906 ("?cannot overlay with controlled object", Expr);
908 ("\?Program_Error will be raised at run time", Expr);
909 Insert_Action (Declaration_Node (U_Ent),
910 Make_Raise_Program_Error (Loc,
911 Reason => PE_Overlaid_Controlled_Object));
914 elsif Present (O_Ent)
915 and then Ekind (U_Ent) = E_Constant
916 and then not Is_Constant_Object (O_Ent)
918 Error_Msg_N ("constant overlays a variable?", Expr);
920 elsif Present (Renamed_Object (U_Ent)) then
922 ("address clause not allowed"
923 & " for a renaming declaration (RM 13.1(6))", Nam);
926 -- Imported variables can have an address clause, but then
927 -- the import is pretty meaningless except to suppress
928 -- initializations, so we do not need such variables to
929 -- be statically allocated (and in fact it causes trouble
930 -- if the address clause is a local value).
932 elsif Is_Imported (U_Ent) then
933 Set_Is_Statically_Allocated (U_Ent, False);
936 -- We mark a possible modification of a variable with an
937 -- address clause, since it is likely aliasing is occurring.
939 Note_Possible_Modification (Nam, Sure => False);
941 -- Here we are checking for explicit overlap of one variable
942 -- by another, and if we find this then mark the overlapped
943 -- variable as also being volatile to prevent unwanted
944 -- optimizations. This is a significant pessimization so
945 -- avoid it when there is an offset, i.e. when the object
946 -- is composite; they cannot be optimized easily anyway.
949 and then Is_Object (O_Ent)
952 Set_Treat_As_Volatile (O_Ent);
955 -- Legality checks on the address clause for initialized
956 -- objects is deferred until the freeze point, because
957 -- a subsequent pragma might indicate that the object is
958 -- imported and thus not initialized.
960 Set_Has_Delayed_Freeze (U_Ent);
962 -- If an initialization call has been generated for this
963 -- object, it needs to be deferred to after the freeze node
964 -- we have just now added, otherwise GIGI will see a
965 -- reference to the variable (as actual to the IP call)
966 -- before its definition.
969 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
971 if Present (Init_Call) then
973 Append_Freeze_Action (U_Ent, Init_Call);
977 if Is_Exported (U_Ent) then
979 ("& cannot be exported if an address clause is given",
982 ("\define and export a variable " &
983 "that holds its address instead",
987 -- Entity has delayed freeze, so we will generate an
988 -- alignment check at the freeze point unless suppressed.
990 if not Range_Checks_Suppressed (U_Ent)
991 and then not Alignment_Checks_Suppressed (U_Ent)
993 Set_Check_Address_Alignment (N);
996 -- Kill the size check code, since we are not allocating
997 -- the variable, it is somewhere else.
999 Kill_Size_Check_Code (U_Ent);
1001 -- If the address clause is of the form:
1003 -- for Y'Address use X'Address
1007 -- Const : constant Address := X'Address;
1009 -- for Y'Address use Const;
1011 -- then we make an entry in the table for checking the size
1012 -- and alignment of the overlaying variable. We defer this
1013 -- check till after code generation to take full advantage
1014 -- of the annotation done by the back end. This entry is
1015 -- only made if the address clause comes from source.
1017 if Address_Clause_Overlay_Warnings
1018 and then Comes_From_Source (N)
1019 and then Present (O_Ent)
1020 and then Is_Object (O_Ent)
1022 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1024 -- If variable overlays a constant view, and we are
1025 -- warning on overlays, then mark the variable as
1026 -- overlaying a constant (we will give warnings later
1027 -- if this variable is assigned).
1029 if Is_Constant_Object (O_Ent)
1030 and then Ekind (U_Ent) = E_Variable
1032 Set_Overlays_Constant (U_Ent);
1037 -- Not a valid entity for an address clause
1040 Error_Msg_N ("address cannot be given for &", Nam);
1048 -- Alignment attribute definition clause
1050 when Attribute_Alignment => Alignment_Block : declare
1051 Align : constant Uint := Get_Alignment_Value (Expr);
1056 if not Is_Type (U_Ent)
1057 and then Ekind (U_Ent) /= E_Variable
1058 and then Ekind (U_Ent) /= E_Constant
1060 Error_Msg_N ("alignment cannot be given for &", Nam);
1062 elsif Has_Alignment_Clause (U_Ent) then
1063 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1064 Error_Msg_N ("alignment clause previously given#", N);
1066 elsif Align /= No_Uint then
1067 Set_Has_Alignment_Clause (U_Ent);
1068 Set_Alignment (U_Ent, Align);
1070 end Alignment_Block;
1076 -- Bit_Order attribute definition clause
1078 when Attribute_Bit_Order => Bit_Order : declare
1080 if not Is_Record_Type (U_Ent) then
1082 ("Bit_Order can only be defined for record type", Nam);
1085 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1087 if Etype (Expr) = Any_Type then
1090 elsif not Is_Static_Expression (Expr) then
1091 Flag_Non_Static_Expr
1092 ("Bit_Order requires static expression!", Expr);
1095 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1096 Set_Reverse_Bit_Order (U_Ent, True);
1102 --------------------
1103 -- Component_Size --
1104 --------------------
1106 -- Component_Size attribute definition clause
1108 when Attribute_Component_Size => Component_Size_Case : declare
1109 Csize : constant Uint := Static_Integer (Expr);
1112 New_Ctyp : Entity_Id;
1116 if not Is_Array_Type (U_Ent) then
1117 Error_Msg_N ("component size requires array type", Nam);
1121 Btype := Base_Type (U_Ent);
1123 if Has_Component_Size_Clause (Btype) then
1125 ("component size clause for& previously given", Nam);
1127 elsif Csize /= No_Uint then
1128 Check_Size (Expr, Component_Type (Btype), Csize, Biased);
1130 if Has_Aliased_Components (Btype)
1133 and then Csize /= 16
1136 ("component size incorrect for aliased components", N);
1140 -- For the biased case, build a declaration for a subtype
1141 -- that will be used to represent the biased subtype that
1142 -- reflects the biased representation of components. We need
1143 -- this subtype to get proper conversions on referencing
1144 -- elements of the array. Note that component size clauses
1145 -- are ignored in VM mode.
1147 if VM_Target = No_VM then
1150 Make_Defining_Identifier (Loc,
1152 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1155 Make_Subtype_Declaration (Loc,
1156 Defining_Identifier => New_Ctyp,
1157 Subtype_Indication =>
1158 New_Occurrence_Of (Component_Type (Btype), Loc));
1160 Set_Parent (Decl, N);
1161 Analyze (Decl, Suppress => All_Checks);
1163 Set_Has_Delayed_Freeze (New_Ctyp, False);
1164 Set_Esize (New_Ctyp, Csize);
1165 Set_RM_Size (New_Ctyp, Csize);
1166 Init_Alignment (New_Ctyp);
1167 Set_Has_Biased_Representation (New_Ctyp, True);
1168 Set_Is_Itype (New_Ctyp, True);
1169 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1171 Set_Component_Type (Btype, New_Ctyp);
1173 if Warn_On_Biased_Representation then
1175 ("?component size clause forces biased "
1176 & "representation", N);
1180 Set_Component_Size (Btype, Csize);
1182 -- For VM case, we ignore component size clauses
1185 -- Give a warning unless we are in GNAT mode, in which case
1186 -- the warning is suppressed since it is not useful.
1188 if not GNAT_Mode then
1190 ("?component size ignored in this configuration", N);
1194 Set_Has_Component_Size_Clause (Btype, True);
1195 Set_Has_Non_Standard_Rep (Btype, True);
1197 end Component_Size_Case;
1203 when Attribute_External_Tag => External_Tag :
1205 if not Is_Tagged_Type (U_Ent) then
1206 Error_Msg_N ("should be a tagged type", Nam);
1209 Analyze_And_Resolve (Expr, Standard_String);
1211 if not Is_Static_Expression (Expr) then
1212 Flag_Non_Static_Expr
1213 ("static string required for tag name!", Nam);
1216 if VM_Target = No_VM then
1217 Set_Has_External_Tag_Rep_Clause (U_Ent);
1219 Error_Msg_Name_1 := Attr;
1221 ("% attribute unsupported in this configuration", Nam);
1224 if not Is_Library_Level_Entity (U_Ent) then
1226 ("?non-unique external tag supplied for &", N, U_Ent);
1228 ("?\same external tag applies to all subprogram calls", N);
1230 ("?\corresponding internal tag cannot be obtained", N);
1238 when Attribute_Input =>
1239 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1240 Set_Has_Specified_Stream_Input (Ent);
1246 -- Machine radix attribute definition clause
1248 when Attribute_Machine_Radix => Machine_Radix : declare
1249 Radix : constant Uint := Static_Integer (Expr);
1252 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1253 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1255 elsif Has_Machine_Radix_Clause (U_Ent) then
1256 Error_Msg_Sloc := Sloc (Alignment_Clause (U_Ent));
1257 Error_Msg_N ("machine radix clause previously given#", N);
1259 elsif Radix /= No_Uint then
1260 Set_Has_Machine_Radix_Clause (U_Ent);
1261 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
1265 elsif Radix = 10 then
1266 Set_Machine_Radix_10 (U_Ent);
1268 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
1277 -- Object_Size attribute definition clause
1279 when Attribute_Object_Size => Object_Size : declare
1280 Size : constant Uint := Static_Integer (Expr);
1283 pragma Warnings (Off, Biased);
1286 if not Is_Type (U_Ent) then
1287 Error_Msg_N ("Object_Size cannot be given for &", Nam);
1289 elsif Has_Object_Size_Clause (U_Ent) then
1290 Error_Msg_N ("Object_Size already given for &", Nam);
1293 Check_Size (Expr, U_Ent, Size, Biased);
1301 UI_Mod (Size, 64) /= 0
1304 ("Object_Size must be 8, 16, 32, or multiple of 64",
1308 Set_Esize (U_Ent, Size);
1309 Set_Has_Object_Size_Clause (U_Ent);
1310 Alignment_Check_For_Esize_Change (U_Ent);
1318 when Attribute_Output =>
1319 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
1320 Set_Has_Specified_Stream_Output (Ent);
1326 when Attribute_Read =>
1327 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
1328 Set_Has_Specified_Stream_Read (Ent);
1334 -- Size attribute definition clause
1336 when Attribute_Size => Size : declare
1337 Size : constant Uint := Static_Integer (Expr);
1344 if Has_Size_Clause (U_Ent) then
1345 Error_Msg_N ("size already given for &", Nam);
1347 elsif not Is_Type (U_Ent)
1348 and then Ekind (U_Ent) /= E_Variable
1349 and then Ekind (U_Ent) /= E_Constant
1351 Error_Msg_N ("size cannot be given for &", Nam);
1353 elsif Is_Array_Type (U_Ent)
1354 and then not Is_Constrained (U_Ent)
1357 ("size cannot be given for unconstrained array", Nam);
1359 elsif Size /= No_Uint then
1360 if Is_Type (U_Ent) then
1363 Etyp := Etype (U_Ent);
1366 -- Check size, note that Gigi is in charge of checking that the
1367 -- size of an array or record type is OK. Also we do not check
1368 -- the size in the ordinary fixed-point case, since it is too
1369 -- early to do so (there may be subsequent small clause that
1370 -- affects the size). We can check the size if a small clause
1371 -- has already been given.
1373 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
1374 or else Has_Small_Clause (U_Ent)
1376 Check_Size (Expr, Etyp, Size, Biased);
1377 Set_Has_Biased_Representation (U_Ent, Biased);
1379 if Biased and Warn_On_Biased_Representation then
1381 ("?size clause forces biased representation", N);
1385 -- For types set RM_Size and Esize if possible
1387 if Is_Type (U_Ent) then
1388 Set_RM_Size (U_Ent, Size);
1390 -- For scalar types, increase Object_Size to power of 2, but
1391 -- not less than a storage unit in any case (i.e., normally
1392 -- this means it will be byte addressable).
1394 if Is_Scalar_Type (U_Ent) then
1395 if Size <= System_Storage_Unit then
1396 Init_Esize (U_Ent, System_Storage_Unit);
1397 elsif Size <= 16 then
1398 Init_Esize (U_Ent, 16);
1399 elsif Size <= 32 then
1400 Init_Esize (U_Ent, 32);
1402 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
1405 -- For all other types, object size = value size. The
1406 -- backend will adjust as needed.
1409 Set_Esize (U_Ent, Size);
1412 Alignment_Check_For_Esize_Change (U_Ent);
1414 -- For objects, set Esize only
1417 if Is_Elementary_Type (Etyp) then
1418 if Size /= System_Storage_Unit
1420 Size /= System_Storage_Unit * 2
1422 Size /= System_Storage_Unit * 4
1424 Size /= System_Storage_Unit * 8
1426 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1427 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
1429 ("size for primitive object must be a power of 2"
1430 & " in the range ^-^", N);
1434 Set_Esize (U_Ent, Size);
1437 Set_Has_Size_Clause (U_Ent);
1445 -- Small attribute definition clause
1447 when Attribute_Small => Small : declare
1448 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
1452 Analyze_And_Resolve (Expr, Any_Real);
1454 if Etype (Expr) = Any_Type then
1457 elsif not Is_Static_Expression (Expr) then
1458 Flag_Non_Static_Expr
1459 ("small requires static expression!", Expr);
1463 Small := Expr_Value_R (Expr);
1465 if Small <= Ureal_0 then
1466 Error_Msg_N ("small value must be greater than zero", Expr);
1472 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
1474 ("small requires an ordinary fixed point type", Nam);
1476 elsif Has_Small_Clause (U_Ent) then
1477 Error_Msg_N ("small already given for &", Nam);
1479 elsif Small > Delta_Value (U_Ent) then
1481 ("small value must not be greater then delta value", Nam);
1484 Set_Small_Value (U_Ent, Small);
1485 Set_Small_Value (Implicit_Base, Small);
1486 Set_Has_Small_Clause (U_Ent);
1487 Set_Has_Small_Clause (Implicit_Base);
1488 Set_Has_Non_Standard_Rep (Implicit_Base);
1496 -- Storage_Pool attribute definition clause
1498 when Attribute_Storage_Pool => Storage_Pool : declare
1503 if Ekind (U_Ent) = E_Access_Subprogram_Type then
1505 ("storage pool cannot be given for access-to-subprogram type",
1509 elsif Ekind (U_Ent) /= E_Access_Type
1510 and then Ekind (U_Ent) /= E_General_Access_Type
1513 ("storage pool can only be given for access types", Nam);
1516 elsif Is_Derived_Type (U_Ent) then
1518 ("storage pool cannot be given for a derived access type",
1521 elsif Has_Storage_Size_Clause (U_Ent) then
1522 Error_Msg_N ("storage size already given for &", Nam);
1525 elsif Present (Associated_Storage_Pool (U_Ent)) then
1526 Error_Msg_N ("storage pool already given for &", Nam);
1531 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
1533 if not Denotes_Variable (Expr) then
1534 Error_Msg_N ("storage pool must be a variable", Expr);
1538 if Nkind (Expr) = N_Type_Conversion then
1539 T := Etype (Expression (Expr));
1544 -- The Stack_Bounded_Pool is used internally for implementing
1545 -- access types with a Storage_Size. Since it only work
1546 -- properly when used on one specific type, we need to check
1547 -- that it is not hijacked improperly:
1548 -- type T is access Integer;
1549 -- for T'Storage_Size use n;
1550 -- type Q is access Float;
1551 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
1553 if RTE_Available (RE_Stack_Bounded_Pool)
1554 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
1556 Error_Msg_N ("non-shareable internal Pool", Expr);
1560 -- If the argument is a name that is not an entity name, then
1561 -- we construct a renaming operation to define an entity of
1562 -- type storage pool.
1564 if not Is_Entity_Name (Expr)
1565 and then Is_Object_Reference (Expr)
1568 Make_Defining_Identifier (Loc,
1569 Chars => New_Internal_Name ('P'));
1572 Rnode : constant Node_Id :=
1573 Make_Object_Renaming_Declaration (Loc,
1574 Defining_Identifier => Pool,
1576 New_Occurrence_Of (Etype (Expr), Loc),
1580 Insert_Before (N, Rnode);
1582 Set_Associated_Storage_Pool (U_Ent, Pool);
1585 elsif Is_Entity_Name (Expr) then
1586 Pool := Entity (Expr);
1588 -- If pool is a renamed object, get original one. This can
1589 -- happen with an explicit renaming, and within instances.
1591 while Present (Renamed_Object (Pool))
1592 and then Is_Entity_Name (Renamed_Object (Pool))
1594 Pool := Entity (Renamed_Object (Pool));
1597 if Present (Renamed_Object (Pool))
1598 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
1599 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
1601 Pool := Entity (Expression (Renamed_Object (Pool)));
1604 Set_Associated_Storage_Pool (U_Ent, Pool);
1606 elsif Nkind (Expr) = N_Type_Conversion
1607 and then Is_Entity_Name (Expression (Expr))
1608 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
1610 Pool := Entity (Expression (Expr));
1611 Set_Associated_Storage_Pool (U_Ent, Pool);
1614 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
1623 -- Storage_Size attribute definition clause
1625 when Attribute_Storage_Size => Storage_Size : declare
1626 Btype : constant Entity_Id := Base_Type (U_Ent);
1630 if Is_Task_Type (U_Ent) then
1631 Check_Restriction (No_Obsolescent_Features, N);
1633 if Warn_On_Obsolescent_Feature then
1635 ("storage size clause for task is an " &
1636 "obsolescent feature (RM J.9)?", N);
1638 ("\use Storage_Size pragma instead?", N);
1644 if not Is_Access_Type (U_Ent)
1645 and then Ekind (U_Ent) /= E_Task_Type
1647 Error_Msg_N ("storage size cannot be given for &", Nam);
1649 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
1651 ("storage size cannot be given for a derived access type",
1654 elsif Has_Storage_Size_Clause (Btype) then
1655 Error_Msg_N ("storage size already given for &", Nam);
1658 Analyze_And_Resolve (Expr, Any_Integer);
1660 if Is_Access_Type (U_Ent) then
1661 if Present (Associated_Storage_Pool (U_Ent)) then
1662 Error_Msg_N ("storage pool already given for &", Nam);
1666 if Compile_Time_Known_Value (Expr)
1667 and then Expr_Value (Expr) = 0
1669 Set_No_Pool_Assigned (Btype);
1672 else -- Is_Task_Type (U_Ent)
1673 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
1675 if Present (Sprag) then
1676 Error_Msg_Sloc := Sloc (Sprag);
1678 ("Storage_Size already specified#", Nam);
1683 Set_Has_Storage_Size_Clause (Btype);
1691 when Attribute_Stream_Size => Stream_Size : declare
1692 Size : constant Uint := Static_Integer (Expr);
1695 if Ada_Version <= Ada_95 then
1696 Check_Restriction (No_Implementation_Attributes, N);
1699 if Has_Stream_Size_Clause (U_Ent) then
1700 Error_Msg_N ("Stream_Size already given for &", Nam);
1702 elsif Is_Elementary_Type (U_Ent) then
1703 if Size /= System_Storage_Unit
1705 Size /= System_Storage_Unit * 2
1707 Size /= System_Storage_Unit * 4
1709 Size /= System_Storage_Unit * 8
1711 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
1713 ("stream size for elementary type must be a"
1714 & " power of 2 and at least ^", N);
1716 elsif RM_Size (U_Ent) > Size then
1717 Error_Msg_Uint_1 := RM_Size (U_Ent);
1719 ("stream size for elementary type must be a"
1720 & " power of 2 and at least ^", N);
1723 Set_Has_Stream_Size_Clause (U_Ent);
1726 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
1734 -- Value_Size attribute definition clause
1736 when Attribute_Value_Size => Value_Size : declare
1737 Size : constant Uint := Static_Integer (Expr);
1741 if not Is_Type (U_Ent) then
1742 Error_Msg_N ("Value_Size cannot be given for &", Nam);
1745 (Get_Attribute_Definition_Clause
1746 (U_Ent, Attribute_Value_Size))
1748 Error_Msg_N ("Value_Size already given for &", Nam);
1750 elsif Is_Array_Type (U_Ent)
1751 and then not Is_Constrained (U_Ent)
1754 ("Value_Size cannot be given for unconstrained array", Nam);
1757 if Is_Elementary_Type (U_Ent) then
1758 Check_Size (Expr, U_Ent, Size, Biased);
1759 Set_Has_Biased_Representation (U_Ent, Biased);
1761 if Biased and Warn_On_Biased_Representation then
1763 ("?value size clause forces biased representation", N);
1767 Set_RM_Size (U_Ent, Size);
1775 when Attribute_Write =>
1776 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
1777 Set_Has_Specified_Stream_Write (Ent);
1779 -- All other attributes cannot be set
1783 ("attribute& cannot be set with definition clause", N);
1786 -- The test for the type being frozen must be performed after
1787 -- any expression the clause has been analyzed since the expression
1788 -- itself might cause freezing that makes the clause illegal.
1790 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
1793 end Analyze_Attribute_Definition_Clause;
1795 ----------------------------
1796 -- Analyze_Code_Statement --
1797 ----------------------------
1799 procedure Analyze_Code_Statement (N : Node_Id) is
1800 HSS : constant Node_Id := Parent (N);
1801 SBody : constant Node_Id := Parent (HSS);
1802 Subp : constant Entity_Id := Current_Scope;
1809 -- Analyze and check we get right type, note that this implements the
1810 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
1811 -- is the only way that Asm_Insn could possibly be visible.
1813 Analyze_And_Resolve (Expression (N));
1815 if Etype (Expression (N)) = Any_Type then
1817 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
1818 Error_Msg_N ("incorrect type for code statement", N);
1822 Check_Code_Statement (N);
1824 -- Make sure we appear in the handled statement sequence of a
1825 -- subprogram (RM 13.8(3)).
1827 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
1828 or else Nkind (SBody) /= N_Subprogram_Body
1831 ("code statement can only appear in body of subprogram", N);
1835 -- Do remaining checks (RM 13.8(3)) if not already done
1837 if not Is_Machine_Code_Subprogram (Subp) then
1838 Set_Is_Machine_Code_Subprogram (Subp);
1840 -- No exception handlers allowed
1842 if Present (Exception_Handlers (HSS)) then
1844 ("exception handlers not permitted in machine code subprogram",
1845 First (Exception_Handlers (HSS)));
1848 -- No declarations other than use clauses and pragmas (we allow
1849 -- certain internally generated declarations as well).
1851 Decl := First (Declarations (SBody));
1852 while Present (Decl) loop
1853 DeclO := Original_Node (Decl);
1854 if Comes_From_Source (DeclO)
1855 and not Nkind_In (DeclO, N_Pragma,
1856 N_Use_Package_Clause,
1858 N_Implicit_Label_Declaration)
1861 ("this declaration not allowed in machine code subprogram",
1868 -- No statements other than code statements, pragmas, and labels.
1869 -- Again we allow certain internally generated statements.
1871 Stmt := First (Statements (HSS));
1872 while Present (Stmt) loop
1873 StmtO := Original_Node (Stmt);
1874 if Comes_From_Source (StmtO)
1875 and then not Nkind_In (StmtO, N_Pragma,
1880 ("this statement is not allowed in machine code subprogram",
1887 end Analyze_Code_Statement;
1889 -----------------------------------------------
1890 -- Analyze_Enumeration_Representation_Clause --
1891 -----------------------------------------------
1893 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
1894 Ident : constant Node_Id := Identifier (N);
1895 Aggr : constant Node_Id := Array_Aggregate (N);
1896 Enumtype : Entity_Id;
1902 Err : Boolean := False;
1904 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
1905 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
1910 if Ignore_Rep_Clauses then
1914 -- First some basic error checks
1917 Enumtype := Entity (Ident);
1919 if Enumtype = Any_Type
1920 or else Rep_Item_Too_Early (Enumtype, N)
1924 Enumtype := Underlying_Type (Enumtype);
1927 if not Is_Enumeration_Type (Enumtype) then
1929 ("enumeration type required, found}",
1930 Ident, First_Subtype (Enumtype));
1934 -- Ignore rep clause on generic actual type. This will already have
1935 -- been flagged on the template as an error, and this is the safest
1936 -- way to ensure we don't get a junk cascaded message in the instance.
1938 if Is_Generic_Actual_Type (Enumtype) then
1941 -- Type must be in current scope
1943 elsif Scope (Enumtype) /= Current_Scope then
1944 Error_Msg_N ("type must be declared in this scope", Ident);
1947 -- Type must be a first subtype
1949 elsif not Is_First_Subtype (Enumtype) then
1950 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
1953 -- Ignore duplicate rep clause
1955 elsif Has_Enumeration_Rep_Clause (Enumtype) then
1956 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
1959 -- Don't allow rep clause for standard [wide_[wide_]]character
1961 elsif Is_Standard_Character_Type (Enumtype) then
1962 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
1965 -- Check that the expression is a proper aggregate (no parentheses)
1967 elsif Paren_Count (Aggr) /= 0 then
1969 ("extra parentheses surrounding aggregate not allowed",
1973 -- All tests passed, so set rep clause in place
1976 Set_Has_Enumeration_Rep_Clause (Enumtype);
1977 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
1980 -- Now we process the aggregate. Note that we don't use the normal
1981 -- aggregate code for this purpose, because we don't want any of the
1982 -- normal expansion activities, and a number of special semantic
1983 -- rules apply (including the component type being any integer type)
1985 Elit := First_Literal (Enumtype);
1987 -- First the positional entries if any
1989 if Present (Expressions (Aggr)) then
1990 Expr := First (Expressions (Aggr));
1991 while Present (Expr) loop
1993 Error_Msg_N ("too many entries in aggregate", Expr);
1997 Val := Static_Integer (Expr);
1999 -- Err signals that we found some incorrect entries processing
2000 -- the list. The final checks for completeness and ordering are
2001 -- skipped in this case.
2003 if Val = No_Uint then
2005 elsif Val < Lo or else Hi < Val then
2006 Error_Msg_N ("value outside permitted range", Expr);
2010 Set_Enumeration_Rep (Elit, Val);
2011 Set_Enumeration_Rep_Expr (Elit, Expr);
2017 -- Now process the named entries if present
2019 if Present (Component_Associations (Aggr)) then
2020 Assoc := First (Component_Associations (Aggr));
2021 while Present (Assoc) loop
2022 Choice := First (Choices (Assoc));
2024 if Present (Next (Choice)) then
2026 ("multiple choice not allowed here", Next (Choice));
2030 if Nkind (Choice) = N_Others_Choice then
2031 Error_Msg_N ("others choice not allowed here", Choice);
2034 elsif Nkind (Choice) = N_Range then
2035 -- ??? should allow zero/one element range here
2036 Error_Msg_N ("range not allowed here", Choice);
2040 Analyze_And_Resolve (Choice, Enumtype);
2042 if Is_Entity_Name (Choice)
2043 and then Is_Type (Entity (Choice))
2045 Error_Msg_N ("subtype name not allowed here", Choice);
2047 -- ??? should allow static subtype with zero/one entry
2049 elsif Etype (Choice) = Base_Type (Enumtype) then
2050 if not Is_Static_Expression (Choice) then
2051 Flag_Non_Static_Expr
2052 ("non-static expression used for choice!", Choice);
2056 Elit := Expr_Value_E (Choice);
2058 if Present (Enumeration_Rep_Expr (Elit)) then
2059 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2061 ("representation for& previously given#",
2066 Set_Enumeration_Rep_Expr (Elit, Choice);
2068 Expr := Expression (Assoc);
2069 Val := Static_Integer (Expr);
2071 if Val = No_Uint then
2074 elsif Val < Lo or else Hi < Val then
2075 Error_Msg_N ("value outside permitted range", Expr);
2079 Set_Enumeration_Rep (Elit, Val);
2088 -- Aggregate is fully processed. Now we check that a full set of
2089 -- representations was given, and that they are in range and in order.
2090 -- These checks are only done if no other errors occurred.
2096 Elit := First_Literal (Enumtype);
2097 while Present (Elit) loop
2098 if No (Enumeration_Rep_Expr (Elit)) then
2099 Error_Msg_NE ("missing representation for&!", N, Elit);
2102 Val := Enumeration_Rep (Elit);
2104 if Min = No_Uint then
2108 if Val /= No_Uint then
2109 if Max /= No_Uint and then Val <= Max then
2111 ("enumeration value for& not ordered!",
2112 Enumeration_Rep_Expr (Elit), Elit);
2118 -- If there is at least one literal whose representation
2119 -- is not equal to the Pos value, then note that this
2120 -- enumeration type has a non-standard representation.
2122 if Val /= Enumeration_Pos (Elit) then
2123 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2130 -- Now set proper size information
2133 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2136 if Has_Size_Clause (Enumtype) then
2137 if Esize (Enumtype) >= Minsize then
2142 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2144 if Esize (Enumtype) < Minsize then
2145 Error_Msg_N ("previously given size is too small", N);
2148 Set_Has_Biased_Representation (Enumtype);
2153 Set_RM_Size (Enumtype, Minsize);
2154 Set_Enum_Esize (Enumtype);
2157 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2158 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2159 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2163 -- We repeat the too late test in case it froze itself!
2165 if Rep_Item_Too_Late (Enumtype, N) then
2168 end Analyze_Enumeration_Representation_Clause;
2170 ----------------------------
2171 -- Analyze_Free_Statement --
2172 ----------------------------
2174 procedure Analyze_Free_Statement (N : Node_Id) is
2176 Analyze (Expression (N));
2177 end Analyze_Free_Statement;
2179 ------------------------------------------
2180 -- Analyze_Record_Representation_Clause --
2181 ------------------------------------------
2183 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
2184 Loc : constant Source_Ptr := Sloc (N);
2185 Ident : constant Node_Id := Identifier (N);
2186 Rectype : Entity_Id;
2192 Hbit : Uint := Uint_0;
2197 Max_Bit_So_Far : Uint;
2198 -- Records the maximum bit position so far. If all field positions
2199 -- are monotonically increasing, then we can skip the circuit for
2200 -- checking for overlap, since no overlap is possible.
2202 Overlap_Check_Required : Boolean;
2203 -- Used to keep track of whether or not an overlap check is required
2205 Ccount : Natural := 0;
2206 -- Number of component clauses in record rep clause
2208 CR_Pragma : Node_Id := Empty;
2209 -- Points to N_Pragma node if Complete_Representation pragma present
2212 if Ignore_Rep_Clauses then
2217 Rectype := Entity (Ident);
2219 if Rectype = Any_Type
2220 or else Rep_Item_Too_Early (Rectype, N)
2224 Rectype := Underlying_Type (Rectype);
2227 -- First some basic error checks
2229 if not Is_Record_Type (Rectype) then
2231 ("record type required, found}", Ident, First_Subtype (Rectype));
2234 elsif Is_Unchecked_Union (Rectype) then
2236 ("record rep clause not allowed for Unchecked_Union", N);
2238 elsif Scope (Rectype) /= Current_Scope then
2239 Error_Msg_N ("type must be declared in this scope", N);
2242 elsif not Is_First_Subtype (Rectype) then
2243 Error_Msg_N ("cannot give record rep clause for subtype", N);
2246 elsif Has_Record_Rep_Clause (Rectype) then
2247 Error_Msg_N ("duplicate record rep clause ignored", N);
2250 elsif Rep_Item_Too_Late (Rectype, N) then
2254 if Present (Mod_Clause (N)) then
2256 Loc : constant Source_Ptr := Sloc (N);
2257 M : constant Node_Id := Mod_Clause (N);
2258 P : constant List_Id := Pragmas_Before (M);
2262 pragma Warnings (Off, Mod_Val);
2265 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
2267 if Warn_On_Obsolescent_Feature then
2269 ("mod clause is an obsolescent feature (RM J.8)?", N);
2271 ("\use alignment attribute definition clause instead?", N);
2278 -- In ASIS_Mode mode, expansion is disabled, but we must convert
2279 -- the Mod clause into an alignment clause anyway, so that the
2280 -- back-end can compute and back-annotate properly the size and
2281 -- alignment of types that may include this record.
2283 -- This seems dubious, this destroys the source tree in a manner
2284 -- not detectable by ASIS ???
2286 if Operating_Mode = Check_Semantics
2290 Make_Attribute_Definition_Clause (Loc,
2291 Name => New_Reference_To (Base_Type (Rectype), Loc),
2292 Chars => Name_Alignment,
2293 Expression => Relocate_Node (Expression (M)));
2295 Set_From_At_Mod (AtM_Nod);
2296 Insert_After (N, AtM_Nod);
2297 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
2298 Set_Mod_Clause (N, Empty);
2301 -- Get the alignment value to perform error checking
2303 Mod_Val := Get_Alignment_Value (Expression (M));
2309 -- For untagged types, clear any existing component clauses for the
2310 -- type. If the type is derived, this is what allows us to override
2311 -- a rep clause for the parent. For type extensions, the representation
2312 -- of the inherited components is inherited, so we want to keep previous
2313 -- component clauses for completeness.
2315 if not Is_Tagged_Type (Rectype) then
2316 Comp := First_Component_Or_Discriminant (Rectype);
2317 while Present (Comp) loop
2318 Set_Component_Clause (Comp, Empty);
2319 Next_Component_Or_Discriminant (Comp);
2323 -- All done if no component clauses
2325 CC := First (Component_Clauses (N));
2331 -- If a tag is present, then create a component clause that places it
2332 -- at the start of the record (otherwise gigi may place it after other
2333 -- fields that have rep clauses).
2335 Fent := First_Entity (Rectype);
2337 if Nkind (Fent) = N_Defining_Identifier
2338 and then Chars (Fent) = Name_uTag
2340 Set_Component_Bit_Offset (Fent, Uint_0);
2341 Set_Normalized_Position (Fent, Uint_0);
2342 Set_Normalized_First_Bit (Fent, Uint_0);
2343 Set_Normalized_Position_Max (Fent, Uint_0);
2344 Init_Esize (Fent, System_Address_Size);
2346 Set_Component_Clause (Fent,
2347 Make_Component_Clause (Loc,
2349 Make_Identifier (Loc,
2350 Chars => Name_uTag),
2353 Make_Integer_Literal (Loc,
2357 Make_Integer_Literal (Loc,
2361 Make_Integer_Literal (Loc,
2362 UI_From_Int (System_Address_Size))));
2364 Ccount := Ccount + 1;
2367 -- A representation like this applies to the base type
2369 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
2370 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
2371 Set_Has_Specified_Layout (Base_Type (Rectype));
2373 Max_Bit_So_Far := Uint_Minus_1;
2374 Overlap_Check_Required := False;
2376 -- Process the component clauses
2378 while Present (CC) loop
2382 if Nkind (CC) = N_Pragma then
2385 -- The only pragma of interest is Complete_Representation
2387 if Pragma_Name (CC) = Name_Complete_Representation then
2391 -- Processing for real component clause
2394 Ccount := Ccount + 1;
2395 Posit := Static_Integer (Position (CC));
2396 Fbit := Static_Integer (First_Bit (CC));
2397 Lbit := Static_Integer (Last_Bit (CC));
2400 and then Fbit /= No_Uint
2401 and then Lbit /= No_Uint
2405 ("position cannot be negative", Position (CC));
2409 ("first bit cannot be negative", First_Bit (CC));
2411 -- The Last_Bit specified in a component clause must not be
2412 -- less than the First_Bit minus one (RM-13.5.1(10)).
2414 elsif Lbit < Fbit - 1 then
2416 ("last bit cannot be less than first bit minus one",
2419 -- Values look OK, so find the corresponding record component
2420 -- Even though the syntax allows an attribute reference for
2421 -- implementation-defined components, GNAT does not allow the
2422 -- tag to get an explicit position.
2424 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
2425 if Attribute_Name (Component_Name (CC)) = Name_Tag then
2426 Error_Msg_N ("position of tag cannot be specified", CC);
2428 Error_Msg_N ("illegal component name", CC);
2432 Comp := First_Entity (Rectype);
2433 while Present (Comp) loop
2434 exit when Chars (Comp) = Chars (Component_Name (CC));
2440 -- Maybe component of base type that is absent from
2441 -- statically constrained first subtype.
2443 Comp := First_Entity (Base_Type (Rectype));
2444 while Present (Comp) loop
2445 exit when Chars (Comp) = Chars (Component_Name (CC));
2452 ("component clause is for non-existent field", CC);
2454 elsif Present (Component_Clause (Comp)) then
2456 -- Diagnose duplicate rep clause, or check consistency
2457 -- if this is an inherited component. In a double fault,
2458 -- there may be a duplicate inconsistent clause for an
2459 -- inherited component.
2461 if Scope (Original_Record_Component (Comp)) = Rectype
2462 or else Parent (Component_Clause (Comp)) = N
2464 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
2465 Error_Msg_N ("component clause previously given#", CC);
2469 Rep1 : constant Node_Id := Component_Clause (Comp);
2471 if Intval (Position (Rep1)) /=
2472 Intval (Position (CC))
2473 or else Intval (First_Bit (Rep1)) /=
2474 Intval (First_Bit (CC))
2475 or else Intval (Last_Bit (Rep1)) /=
2476 Intval (Last_Bit (CC))
2478 Error_Msg_N ("component clause inconsistent "
2479 & "with representation of ancestor", CC);
2480 elsif Warn_On_Redundant_Constructs then
2481 Error_Msg_N ("?redundant component clause "
2482 & "for inherited component!", CC);
2488 -- Make reference for field in record rep clause and set
2489 -- appropriate entity field in the field identifier.
2492 (Comp, Component_Name (CC), Set_Ref => False);
2493 Set_Entity (Component_Name (CC), Comp);
2495 -- Update Fbit and Lbit to the actual bit number
2497 Fbit := Fbit + UI_From_Int (SSU) * Posit;
2498 Lbit := Lbit + UI_From_Int (SSU) * Posit;
2500 if Fbit <= Max_Bit_So_Far then
2501 Overlap_Check_Required := True;
2503 Max_Bit_So_Far := Lbit;
2506 if Has_Size_Clause (Rectype)
2507 and then Esize (Rectype) <= Lbit
2510 ("bit number out of range of specified size",
2513 Set_Component_Clause (Comp, CC);
2514 Set_Component_Bit_Offset (Comp, Fbit);
2515 Set_Esize (Comp, 1 + (Lbit - Fbit));
2516 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
2517 Set_Normalized_Position (Comp, Fbit / SSU);
2519 Set_Normalized_Position_Max
2520 (Fent, Normalized_Position (Fent));
2522 if Is_Tagged_Type (Rectype)
2523 and then Fbit < System_Address_Size
2526 ("component overlaps tag field of&",
2530 -- This information is also set in the corresponding
2531 -- component of the base type, found by accessing the
2532 -- Original_Record_Component link if it is present.
2534 Ocomp := Original_Record_Component (Comp);
2541 (Component_Name (CC),
2546 Set_Has_Biased_Representation (Comp, Biased);
2548 if Biased and Warn_On_Biased_Representation then
2550 ("?component clause forces biased "
2551 & "representation", CC);
2554 if Present (Ocomp) then
2555 Set_Component_Clause (Ocomp, CC);
2556 Set_Component_Bit_Offset (Ocomp, Fbit);
2557 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
2558 Set_Normalized_Position (Ocomp, Fbit / SSU);
2559 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
2561 Set_Normalized_Position_Max
2562 (Ocomp, Normalized_Position (Ocomp));
2564 Set_Has_Biased_Representation
2565 (Ocomp, Has_Biased_Representation (Comp));
2568 if Esize (Comp) < 0 then
2569 Error_Msg_N ("component size is negative", CC);
2580 -- Now that we have processed all the component clauses, check for
2581 -- overlap. We have to leave this till last, since the components can
2582 -- appear in any arbitrary order in the representation clause.
2584 -- We do not need this check if all specified ranges were monotonic,
2585 -- as recorded by Overlap_Check_Required being False at this stage.
2587 -- This first section checks if there are any overlapping entries at
2588 -- all. It does this by sorting all entries and then seeing if there are
2589 -- any overlaps. If there are none, then that is decisive, but if there
2590 -- are overlaps, they may still be OK (they may result from fields in
2591 -- different variants).
2593 if Overlap_Check_Required then
2594 Overlap_Check1 : declare
2596 OC_Fbit : array (0 .. Ccount) of Uint;
2597 -- First-bit values for component clauses, the value is the offset
2598 -- of the first bit of the field from start of record. The zero
2599 -- entry is for use in sorting.
2601 OC_Lbit : array (0 .. Ccount) of Uint;
2602 -- Last-bit values for component clauses, the value is the offset
2603 -- of the last bit of the field from start of record. The zero
2604 -- entry is for use in sorting.
2606 OC_Count : Natural := 0;
2607 -- Count of entries in OC_Fbit and OC_Lbit
2609 function OC_Lt (Op1, Op2 : Natural) return Boolean;
2610 -- Compare routine for Sort
2612 procedure OC_Move (From : Natural; To : Natural);
2613 -- Move routine for Sort
2615 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
2617 function OC_Lt (Op1, Op2 : Natural) return Boolean is
2619 return OC_Fbit (Op1) < OC_Fbit (Op2);
2622 procedure OC_Move (From : Natural; To : Natural) is
2624 OC_Fbit (To) := OC_Fbit (From);
2625 OC_Lbit (To) := OC_Lbit (From);
2629 CC := First (Component_Clauses (N));
2630 while Present (CC) loop
2631 if Nkind (CC) /= N_Pragma then
2632 Posit := Static_Integer (Position (CC));
2633 Fbit := Static_Integer (First_Bit (CC));
2634 Lbit := Static_Integer (Last_Bit (CC));
2637 and then Fbit /= No_Uint
2638 and then Lbit /= No_Uint
2640 OC_Count := OC_Count + 1;
2641 Posit := Posit * SSU;
2642 OC_Fbit (OC_Count) := Fbit + Posit;
2643 OC_Lbit (OC_Count) := Lbit + Posit;
2650 Sorting.Sort (OC_Count);
2652 Overlap_Check_Required := False;
2653 for J in 1 .. OC_Count - 1 loop
2654 if OC_Lbit (J) >= OC_Fbit (J + 1) then
2655 Overlap_Check_Required := True;
2662 -- If Overlap_Check_Required is still True, then we have to do the full
2663 -- scale overlap check, since we have at least two fields that do
2664 -- overlap, and we need to know if that is OK since they are in
2665 -- different variant, or whether we have a definite problem.
2667 if Overlap_Check_Required then
2668 Overlap_Check2 : declare
2669 C1_Ent, C2_Ent : Entity_Id;
2670 -- Entities of components being checked for overlap
2673 -- Component_List node whose Component_Items are being checked
2676 -- Component declaration for component being checked
2679 C1_Ent := First_Entity (Base_Type (Rectype));
2681 -- Loop through all components in record. For each component check
2682 -- for overlap with any of the preceding elements on the component
2683 -- list containing the component and also, if the component is in
2684 -- a variant, check against components outside the case structure.
2685 -- This latter test is repeated recursively up the variant tree.
2687 Main_Component_Loop : while Present (C1_Ent) loop
2688 if Ekind (C1_Ent) /= E_Component
2689 and then Ekind (C1_Ent) /= E_Discriminant
2691 goto Continue_Main_Component_Loop;
2694 -- Skip overlap check if entity has no declaration node. This
2695 -- happens with discriminants in constrained derived types.
2696 -- Probably we are missing some checks as a result, but that
2697 -- does not seem terribly serious ???
2699 if No (Declaration_Node (C1_Ent)) then
2700 goto Continue_Main_Component_Loop;
2703 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
2705 -- Loop through component lists that need checking. Check the
2706 -- current component list and all lists in variants above us.
2708 Component_List_Loop : loop
2710 -- If derived type definition, go to full declaration
2711 -- If at outer level, check discriminants if there are any.
2713 if Nkind (Clist) = N_Derived_Type_Definition then
2714 Clist := Parent (Clist);
2717 -- Outer level of record definition, check discriminants
2719 if Nkind_In (Clist, N_Full_Type_Declaration,
2720 N_Private_Type_Declaration)
2722 if Has_Discriminants (Defining_Identifier (Clist)) then
2724 First_Discriminant (Defining_Identifier (Clist));
2726 while Present (C2_Ent) loop
2727 exit when C1_Ent = C2_Ent;
2728 Check_Component_Overlap (C1_Ent, C2_Ent);
2729 Next_Discriminant (C2_Ent);
2733 -- Record extension case
2735 elsif Nkind (Clist) = N_Derived_Type_Definition then
2738 -- Otherwise check one component list
2741 Citem := First (Component_Items (Clist));
2743 while Present (Citem) loop
2744 if Nkind (Citem) = N_Component_Declaration then
2745 C2_Ent := Defining_Identifier (Citem);
2746 exit when C1_Ent = C2_Ent;
2747 Check_Component_Overlap (C1_Ent, C2_Ent);
2754 -- Check for variants above us (the parent of the Clist can
2755 -- be a variant, in which case its parent is a variant part,
2756 -- and the parent of the variant part is a component list
2757 -- whose components must all be checked against the current
2758 -- component for overlap).
2760 if Nkind (Parent (Clist)) = N_Variant then
2761 Clist := Parent (Parent (Parent (Clist)));
2763 -- Check for possible discriminant part in record, this is
2764 -- treated essentially as another level in the recursion.
2765 -- For this case the parent of the component list is the
2766 -- record definition, and its parent is the full type
2767 -- declaration containing the discriminant specifications.
2769 elsif Nkind (Parent (Clist)) = N_Record_Definition then
2770 Clist := Parent (Parent ((Clist)));
2772 -- If neither of these two cases, we are at the top of
2776 exit Component_List_Loop;
2778 end loop Component_List_Loop;
2780 <<Continue_Main_Component_Loop>>
2781 Next_Entity (C1_Ent);
2783 end loop Main_Component_Loop;
2787 -- For records that have component clauses for all components, and whose
2788 -- size is less than or equal to 32, we need to know the size in the
2789 -- front end to activate possible packed array processing where the
2790 -- component type is a record.
2792 -- At this stage Hbit + 1 represents the first unused bit from all the
2793 -- component clauses processed, so if the component clauses are
2794 -- complete, then this is the length of the record.
2796 -- For records longer than System.Storage_Unit, and for those where not
2797 -- all components have component clauses, the back end determines the
2798 -- length (it may for example be appropriate to round up the size
2799 -- to some convenient boundary, based on alignment considerations, etc).
2801 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
2803 -- Nothing to do if at least one component has no component clause
2805 Comp := First_Component_Or_Discriminant (Rectype);
2806 while Present (Comp) loop
2807 exit when No (Component_Clause (Comp));
2808 Next_Component_Or_Discriminant (Comp);
2811 -- If we fall out of loop, all components have component clauses
2812 -- and so we can set the size to the maximum value.
2815 Set_RM_Size (Rectype, Hbit + 1);
2819 -- Check missing components if Complete_Representation pragma appeared
2821 if Present (CR_Pragma) then
2822 Comp := First_Component_Or_Discriminant (Rectype);
2823 while Present (Comp) loop
2824 if No (Component_Clause (Comp)) then
2826 ("missing component clause for &", CR_Pragma, Comp);
2829 Next_Component_Or_Discriminant (Comp);
2832 -- If no Complete_Representation pragma, warn if missing components
2834 elsif Warn_On_Unrepped_Components then
2836 Num_Repped_Components : Nat := 0;
2837 Num_Unrepped_Components : Nat := 0;
2840 -- First count number of repped and unrepped components
2842 Comp := First_Component_Or_Discriminant (Rectype);
2843 while Present (Comp) loop
2844 if Present (Component_Clause (Comp)) then
2845 Num_Repped_Components := Num_Repped_Components + 1;
2847 Num_Unrepped_Components := Num_Unrepped_Components + 1;
2850 Next_Component_Or_Discriminant (Comp);
2853 -- We are only interested in the case where there is at least one
2854 -- unrepped component, and at least half the components have rep
2855 -- clauses. We figure that if less than half have them, then the
2856 -- partial rep clause is really intentional. If the component
2857 -- type has no underlying type set at this point (as for a generic
2858 -- formal type), we don't know enough to give a warning on the
2861 if Num_Unrepped_Components > 0
2862 and then Num_Unrepped_Components < Num_Repped_Components
2864 Comp := First_Component_Or_Discriminant (Rectype);
2865 while Present (Comp) loop
2866 if No (Component_Clause (Comp))
2867 and then Comes_From_Source (Comp)
2868 and then Present (Underlying_Type (Etype (Comp)))
2869 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
2870 or else Size_Known_At_Compile_Time
2871 (Underlying_Type (Etype (Comp))))
2872 and then not Has_Warnings_Off (Rectype)
2874 Error_Msg_Sloc := Sloc (Comp);
2876 ("?no component clause given for & declared #",
2880 Next_Component_Or_Discriminant (Comp);
2885 end Analyze_Record_Representation_Clause;
2887 -----------------------------
2888 -- Check_Component_Overlap --
2889 -----------------------------
2891 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
2893 if Present (Component_Clause (C1_Ent))
2894 and then Present (Component_Clause (C2_Ent))
2896 -- Exclude odd case where we have two tag fields in the same record,
2897 -- both at location zero. This seems a bit strange, but it seems to
2898 -- happen in some circumstances ???
2900 if Chars (C1_Ent) = Name_uTag
2901 and then Chars (C2_Ent) = Name_uTag
2906 -- Here we check if the two fields overlap
2909 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
2910 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
2911 E1 : constant Uint := S1 + Esize (C1_Ent);
2912 E2 : constant Uint := S2 + Esize (C2_Ent);
2915 if E2 <= S1 or else E1 <= S2 then
2919 Component_Name (Component_Clause (C2_Ent));
2920 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
2922 Component_Name (Component_Clause (C1_Ent));
2924 ("component& overlaps & #",
2925 Component_Name (Component_Clause (C1_Ent)));
2929 end Check_Component_Overlap;
2931 -----------------------------------
2932 -- Check_Constant_Address_Clause --
2933 -----------------------------------
2935 procedure Check_Constant_Address_Clause
2939 procedure Check_At_Constant_Address (Nod : Node_Id);
2940 -- Checks that the given node N represents a name whose 'Address is
2941 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
2942 -- address value is the same at the point of declaration of U_Ent and at
2943 -- the time of elaboration of the address clause.
2945 procedure Check_Expr_Constants (Nod : Node_Id);
2946 -- Checks that Nod meets the requirements for a constant address clause
2947 -- in the sense of the enclosing procedure.
2949 procedure Check_List_Constants (Lst : List_Id);
2950 -- Check that all elements of list Lst meet the requirements for a
2951 -- constant address clause in the sense of the enclosing procedure.
2953 -------------------------------
2954 -- Check_At_Constant_Address --
2955 -------------------------------
2957 procedure Check_At_Constant_Address (Nod : Node_Id) is
2959 if Is_Entity_Name (Nod) then
2960 if Present (Address_Clause (Entity ((Nod)))) then
2962 ("invalid address clause for initialized object &!",
2965 ("address for& cannot" &
2966 " depend on another address clause! (RM 13.1(22))!",
2969 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
2970 and then Sloc (U_Ent) < Sloc (Entity (Nod))
2973 ("invalid address clause for initialized object &!",
2975 Error_Msg_Node_2 := U_Ent;
2977 ("\& must be defined before & (RM 13.1(22))!",
2981 elsif Nkind (Nod) = N_Selected_Component then
2983 T : constant Entity_Id := Etype (Prefix (Nod));
2986 if (Is_Record_Type (T)
2987 and then Has_Discriminants (T))
2990 and then Is_Record_Type (Designated_Type (T))
2991 and then Has_Discriminants (Designated_Type (T)))
2994 ("invalid address clause for initialized object &!",
2997 ("\address cannot depend on component" &
2998 " of discriminated record (RM 13.1(22))!",
3001 Check_At_Constant_Address (Prefix (Nod));
3005 elsif Nkind (Nod) = N_Indexed_Component then
3006 Check_At_Constant_Address (Prefix (Nod));
3007 Check_List_Constants (Expressions (Nod));
3010 Check_Expr_Constants (Nod);
3012 end Check_At_Constant_Address;
3014 --------------------------
3015 -- Check_Expr_Constants --
3016 --------------------------
3018 procedure Check_Expr_Constants (Nod : Node_Id) is
3019 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
3020 Ent : Entity_Id := Empty;
3023 if Nkind (Nod) in N_Has_Etype
3024 and then Etype (Nod) = Any_Type
3030 when N_Empty | N_Error =>
3033 when N_Identifier | N_Expanded_Name =>
3034 Ent := Entity (Nod);
3036 -- We need to look at the original node if it is different
3037 -- from the node, since we may have rewritten things and
3038 -- substituted an identifier representing the rewrite.
3040 if Original_Node (Nod) /= Nod then
3041 Check_Expr_Constants (Original_Node (Nod));
3043 -- If the node is an object declaration without initial
3044 -- value, some code has been expanded, and the expression
3045 -- is not constant, even if the constituents might be
3046 -- acceptable, as in A'Address + offset.
3048 if Ekind (Ent) = E_Variable
3050 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
3052 No (Expression (Declaration_Node (Ent)))
3055 ("invalid address clause for initialized object &!",
3058 -- If entity is constant, it may be the result of expanding
3059 -- a check. We must verify that its declaration appears
3060 -- before the object in question, else we also reject the
3063 elsif Ekind (Ent) = E_Constant
3064 and then In_Same_Source_Unit (Ent, U_Ent)
3065 and then Sloc (Ent) > Loc_U_Ent
3068 ("invalid address clause for initialized object &!",
3075 -- Otherwise look at the identifier and see if it is OK
3077 if Ekind (Ent) = E_Named_Integer
3079 Ekind (Ent) = E_Named_Real
3086 Ekind (Ent) = E_Constant
3088 Ekind (Ent) = E_In_Parameter
3090 -- This is the case where we must have Ent defined before
3091 -- U_Ent. Clearly if they are in different units this
3092 -- requirement is met since the unit containing Ent is
3093 -- already processed.
3095 if not In_Same_Source_Unit (Ent, U_Ent) then
3098 -- Otherwise location of Ent must be before the location
3099 -- of U_Ent, that's what prior defined means.
3101 elsif Sloc (Ent) < Loc_U_Ent then
3106 ("invalid address clause for initialized object &!",
3108 Error_Msg_Node_2 := U_Ent;
3110 ("\& must be defined before & (RM 13.1(22))!",
3114 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
3115 Check_Expr_Constants (Original_Node (Nod));
3119 ("invalid address clause for initialized object &!",
3122 if Comes_From_Source (Ent) then
3124 ("\reference to variable& not allowed"
3125 & " (RM 13.1(22))!", Nod, Ent);
3128 ("non-static expression not allowed"
3129 & " (RM 13.1(22))!", Nod);
3133 when N_Integer_Literal =>
3135 -- If this is a rewritten unchecked conversion, in a system
3136 -- where Address is an integer type, always use the base type
3137 -- for a literal value. This is user-friendly and prevents
3138 -- order-of-elaboration issues with instances of unchecked
3141 if Nkind (Original_Node (Nod)) = N_Function_Call then
3142 Set_Etype (Nod, Base_Type (Etype (Nod)));
3145 when N_Real_Literal |
3147 N_Character_Literal =>
3151 Check_Expr_Constants (Low_Bound (Nod));
3152 Check_Expr_Constants (High_Bound (Nod));
3154 when N_Explicit_Dereference =>
3155 Check_Expr_Constants (Prefix (Nod));
3157 when N_Indexed_Component =>
3158 Check_Expr_Constants (Prefix (Nod));
3159 Check_List_Constants (Expressions (Nod));
3162 Check_Expr_Constants (Prefix (Nod));
3163 Check_Expr_Constants (Discrete_Range (Nod));
3165 when N_Selected_Component =>
3166 Check_Expr_Constants (Prefix (Nod));
3168 when N_Attribute_Reference =>
3169 if Attribute_Name (Nod) = Name_Address
3171 Attribute_Name (Nod) = Name_Access
3173 Attribute_Name (Nod) = Name_Unchecked_Access
3175 Attribute_Name (Nod) = Name_Unrestricted_Access
3177 Check_At_Constant_Address (Prefix (Nod));
3180 Check_Expr_Constants (Prefix (Nod));
3181 Check_List_Constants (Expressions (Nod));
3185 Check_List_Constants (Component_Associations (Nod));
3186 Check_List_Constants (Expressions (Nod));
3188 when N_Component_Association =>
3189 Check_Expr_Constants (Expression (Nod));
3191 when N_Extension_Aggregate =>
3192 Check_Expr_Constants (Ancestor_Part (Nod));
3193 Check_List_Constants (Component_Associations (Nod));
3194 Check_List_Constants (Expressions (Nod));
3199 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
3200 Check_Expr_Constants (Left_Opnd (Nod));
3201 Check_Expr_Constants (Right_Opnd (Nod));
3204 Check_Expr_Constants (Right_Opnd (Nod));
3206 when N_Type_Conversion |
3207 N_Qualified_Expression |
3209 Check_Expr_Constants (Expression (Nod));
3211 when N_Unchecked_Type_Conversion =>
3212 Check_Expr_Constants (Expression (Nod));
3214 -- If this is a rewritten unchecked conversion, subtypes in
3215 -- this node are those created within the instance. To avoid
3216 -- order of elaboration issues, replace them with their base
3217 -- types. Note that address clauses can cause order of
3218 -- elaboration problems because they are elaborated by the
3219 -- back-end at the point of definition, and may mention
3220 -- entities declared in between (as long as everything is
3221 -- static). It is user-friendly to allow unchecked conversions
3224 if Nkind (Original_Node (Nod)) = N_Function_Call then
3225 Set_Etype (Expression (Nod),
3226 Base_Type (Etype (Expression (Nod))));
3227 Set_Etype (Nod, Base_Type (Etype (Nod)));
3230 when N_Function_Call =>
3231 if not Is_Pure (Entity (Name (Nod))) then
3233 ("invalid address clause for initialized object &!",
3237 ("\function & is not pure (RM 13.1(22))!",
3238 Nod, Entity (Name (Nod)));
3241 Check_List_Constants (Parameter_Associations (Nod));
3244 when N_Parameter_Association =>
3245 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
3249 ("invalid address clause for initialized object &!",
3252 ("\must be constant defined before& (RM 13.1(22))!",
3255 end Check_Expr_Constants;
3257 --------------------------
3258 -- Check_List_Constants --
3259 --------------------------
3261 procedure Check_List_Constants (Lst : List_Id) is
3265 if Present (Lst) then
3266 Nod1 := First (Lst);
3267 while Present (Nod1) loop
3268 Check_Expr_Constants (Nod1);
3272 end Check_List_Constants;
3274 -- Start of processing for Check_Constant_Address_Clause
3277 Check_Expr_Constants (Expr);
3278 end Check_Constant_Address_Clause;
3284 procedure Check_Size
3288 Biased : out Boolean)
3290 UT : constant Entity_Id := Underlying_Type (T);
3296 -- Dismiss cases for generic types or types with previous errors
3299 or else UT = Any_Type
3300 or else Is_Generic_Type (UT)
3301 or else Is_Generic_Type (Root_Type (UT))
3305 -- Check case of bit packed array
3307 elsif Is_Array_Type (UT)
3308 and then Known_Static_Component_Size (UT)
3309 and then Is_Bit_Packed_Array (UT)
3317 Asiz := Component_Size (UT);
3318 Indx := First_Index (UT);
3320 Ityp := Etype (Indx);
3322 -- If non-static bound, then we are not in the business of
3323 -- trying to check the length, and indeed an error will be
3324 -- issued elsewhere, since sizes of non-static array types
3325 -- cannot be set implicitly or explicitly.
3327 if not Is_Static_Subtype (Ityp) then
3331 -- Otherwise accumulate next dimension
3333 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
3334 Expr_Value (Type_Low_Bound (Ityp)) +
3338 exit when No (Indx);
3344 Error_Msg_Uint_1 := Asiz;
3346 ("size for& too small, minimum allowed is ^", N, T);
3347 Set_Esize (T, Asiz);
3348 Set_RM_Size (T, Asiz);
3352 -- All other composite types are ignored
3354 elsif Is_Composite_Type (UT) then
3357 -- For fixed-point types, don't check minimum if type is not frozen,
3358 -- since we don't know all the characteristics of the type that can
3359 -- affect the size (e.g. a specified small) till freeze time.
3361 elsif Is_Fixed_Point_Type (UT)
3362 and then not Is_Frozen (UT)
3366 -- Cases for which a minimum check is required
3369 -- Ignore if specified size is correct for the type
3371 if Known_Esize (UT) and then Siz = Esize (UT) then
3375 -- Otherwise get minimum size
3377 M := UI_From_Int (Minimum_Size (UT));
3381 -- Size is less than minimum size, but one possibility remains
3382 -- that we can manage with the new size if we bias the type.
3384 M := UI_From_Int (Minimum_Size (UT, Biased => True));
3387 Error_Msg_Uint_1 := M;
3389 ("size for& too small, minimum allowed is ^", N, T);
3399 -------------------------
3400 -- Get_Alignment_Value --
3401 -------------------------
3403 function Get_Alignment_Value (Expr : Node_Id) return Uint is
3404 Align : constant Uint := Static_Integer (Expr);
3407 if Align = No_Uint then
3410 elsif Align <= 0 then
3411 Error_Msg_N ("alignment value must be positive", Expr);
3415 for J in Int range 0 .. 64 loop
3417 M : constant Uint := Uint_2 ** J;
3420 exit when M = Align;
3424 ("alignment value must be power of 2", Expr);
3432 end Get_Alignment_Value;
3438 procedure Initialize is
3440 Unchecked_Conversions.Init;
3443 -------------------------
3444 -- Is_Operational_Item --
3445 -------------------------
3447 function Is_Operational_Item (N : Node_Id) return Boolean is
3449 if Nkind (N) /= N_Attribute_Definition_Clause then
3453 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
3455 return Id = Attribute_Input
3456 or else Id = Attribute_Output
3457 or else Id = Attribute_Read
3458 or else Id = Attribute_Write
3459 or else Id = Attribute_External_Tag;
3462 end Is_Operational_Item;
3468 function Minimum_Size
3470 Biased : Boolean := False) return Nat
3472 Lo : Uint := No_Uint;
3473 Hi : Uint := No_Uint;
3474 LoR : Ureal := No_Ureal;
3475 HiR : Ureal := No_Ureal;
3476 LoSet : Boolean := False;
3477 HiSet : Boolean := False;
3481 R_Typ : constant Entity_Id := Root_Type (T);
3484 -- If bad type, return 0
3486 if T = Any_Type then
3489 -- For generic types, just return zero. There cannot be any legitimate
3490 -- need to know such a size, but this routine may be called with a
3491 -- generic type as part of normal processing.
3493 elsif Is_Generic_Type (R_Typ)
3494 or else R_Typ = Any_Type
3498 -- Access types. Normally an access type cannot have a size smaller
3499 -- than the size of System.Address. The exception is on VMS, where
3500 -- we have short and long addresses, and it is possible for an access
3501 -- type to have a short address size (and thus be less than the size
3502 -- of System.Address itself). We simply skip the check for VMS, and
3503 -- leave it to the back end to do the check.
3505 elsif Is_Access_Type (T) then
3506 if OpenVMS_On_Target then
3509 return System_Address_Size;
3512 -- Floating-point types
3514 elsif Is_Floating_Point_Type (T) then
3515 return UI_To_Int (Esize (R_Typ));
3519 elsif Is_Discrete_Type (T) then
3521 -- The following loop is looking for the nearest compile time known
3522 -- bounds following the ancestor subtype chain. The idea is to find
3523 -- the most restrictive known bounds information.
3527 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3532 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
3533 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
3540 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
3541 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
3547 Ancest := Ancestor_Subtype (Ancest);
3550 Ancest := Base_Type (T);
3552 if Is_Generic_Type (Ancest) then
3558 -- Fixed-point types. We can't simply use Expr_Value to get the
3559 -- Corresponding_Integer_Value values of the bounds, since these do not
3560 -- get set till the type is frozen, and this routine can be called
3561 -- before the type is frozen. Similarly the test for bounds being static
3562 -- needs to include the case where we have unanalyzed real literals for
3565 elsif Is_Fixed_Point_Type (T) then
3567 -- The following loop is looking for the nearest compile time known
3568 -- bounds following the ancestor subtype chain. The idea is to find
3569 -- the most restrictive known bounds information.
3573 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
3577 -- Note: In the following two tests for LoSet and HiSet, it may
3578 -- seem redundant to test for N_Real_Literal here since normally
3579 -- one would assume that the test for the value being known at
3580 -- compile time includes this case. However, there is a glitch.
3581 -- If the real literal comes from folding a non-static expression,
3582 -- then we don't consider any non- static expression to be known
3583 -- at compile time if we are in configurable run time mode (needed
3584 -- in some cases to give a clearer definition of what is and what
3585 -- is not accepted). So the test is indeed needed. Without it, we
3586 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
3589 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
3590 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
3592 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
3599 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
3600 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
3602 HiR := Expr_Value_R (Type_High_Bound (Ancest));
3608 Ancest := Ancestor_Subtype (Ancest);
3611 Ancest := Base_Type (T);
3613 if Is_Generic_Type (Ancest) then
3619 Lo := UR_To_Uint (LoR / Small_Value (T));
3620 Hi := UR_To_Uint (HiR / Small_Value (T));
3622 -- No other types allowed
3625 raise Program_Error;
3628 -- Fall through with Hi and Lo set. Deal with biased case
3631 and then not Is_Fixed_Point_Type (T)
3632 and then not (Is_Enumeration_Type (T)
3633 and then Has_Non_Standard_Rep (T)))
3634 or else Has_Biased_Representation (T)
3640 -- Signed case. Note that we consider types like range 1 .. -1 to be
3641 -- signed for the purpose of computing the size, since the bounds have
3642 -- to be accommodated in the base type.
3644 if Lo < 0 or else Hi < 0 then
3648 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
3649 -- Note that we accommodate the case where the bounds cross. This
3650 -- can happen either because of the way the bounds are declared
3651 -- or because of the algorithm in Freeze_Fixed_Point_Type.
3665 -- If both bounds are positive, make sure that both are represen-
3666 -- table in the case where the bounds are crossed. This can happen
3667 -- either because of the way the bounds are declared, or because of
3668 -- the algorithm in Freeze_Fixed_Point_Type.
3674 -- S = size, (can accommodate 0 .. (2**size - 1))
3677 while Hi >= Uint_2 ** S loop
3685 ---------------------------
3686 -- New_Stream_Subprogram --
3687 ---------------------------
3689 procedure New_Stream_Subprogram
3693 Nam : TSS_Name_Type)
3695 Loc : constant Source_Ptr := Sloc (N);
3696 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
3697 Subp_Id : Entity_Id;
3698 Subp_Decl : Node_Id;
3702 Defer_Declaration : constant Boolean :=
3703 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
3704 -- For a tagged type, there is a declaration for each stream attribute
3705 -- at the freeze point, and we must generate only a completion of this
3706 -- declaration. We do the same for private types, because the full view
3707 -- might be tagged. Otherwise we generate a declaration at the point of
3708 -- the attribute definition clause.
3710 function Build_Spec return Node_Id;
3711 -- Used for declaration and renaming declaration, so that this is
3712 -- treated as a renaming_as_body.
3718 function Build_Spec return Node_Id is
3719 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
3722 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
3725 Subp_Id := Make_Defining_Identifier (Loc, Sname);
3727 -- S : access Root_Stream_Type'Class
3729 Formals := New_List (
3730 Make_Parameter_Specification (Loc,
3731 Defining_Identifier =>
3732 Make_Defining_Identifier (Loc, Name_S),
3734 Make_Access_Definition (Loc,
3737 Designated_Type (Etype (F)), Loc))));
3739 if Nam = TSS_Stream_Input then
3740 Spec := Make_Function_Specification (Loc,
3741 Defining_Unit_Name => Subp_Id,
3742 Parameter_Specifications => Formals,
3743 Result_Definition => T_Ref);
3748 Make_Parameter_Specification (Loc,
3749 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
3750 Out_Present => Out_P,
3751 Parameter_Type => T_Ref));
3753 Spec := Make_Procedure_Specification (Loc,
3754 Defining_Unit_Name => Subp_Id,
3755 Parameter_Specifications => Formals);
3761 -- Start of processing for New_Stream_Subprogram
3764 F := First_Formal (Subp);
3766 if Ekind (Subp) = E_Procedure then
3767 Etyp := Etype (Next_Formal (F));
3769 Etyp := Etype (Subp);
3772 -- Prepare subprogram declaration and insert it as an action on the
3773 -- clause node. The visibility for this entity is used to test for
3774 -- visibility of the attribute definition clause (in the sense of
3775 -- 8.3(23) as amended by AI-195).
3777 if not Defer_Declaration then
3779 Make_Subprogram_Declaration (Loc,
3780 Specification => Build_Spec);
3782 -- For a tagged type, there is always a visible declaration for each
3783 -- stream TSS (it is a predefined primitive operation), and the
3784 -- completion of this declaration occurs at the freeze point, which is
3785 -- not always visible at places where the attribute definition clause is
3786 -- visible. So, we create a dummy entity here for the purpose of
3787 -- tracking the visibility of the attribute definition clause itself.
3791 Make_Defining_Identifier (Loc,
3792 Chars => New_External_Name (Sname, 'V'));
3794 Make_Object_Declaration (Loc,
3795 Defining_Identifier => Subp_Id,
3796 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
3799 Insert_Action (N, Subp_Decl);
3800 Set_Entity (N, Subp_Id);
3803 Make_Subprogram_Renaming_Declaration (Loc,
3804 Specification => Build_Spec,
3805 Name => New_Reference_To (Subp, Loc));
3807 if Defer_Declaration then
3808 Set_TSS (Base_Type (Ent), Subp_Id);
3810 Insert_Action (N, Subp_Decl);
3811 Copy_TSS (Subp_Id, Base_Type (Ent));
3813 end New_Stream_Subprogram;
3815 ------------------------
3816 -- Rep_Item_Too_Early --
3817 ------------------------
3819 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
3821 -- Cannot apply non-operational rep items to generic types
3823 if Is_Operational_Item (N) then
3827 and then Is_Generic_Type (Root_Type (T))
3830 ("representation item not allowed for generic type", N);
3834 -- Otherwise check for incomplete type
3836 if Is_Incomplete_Or_Private_Type (T)
3837 and then No (Underlying_Type (T))
3840 ("representation item must be after full type declaration", N);
3843 -- If the type has incomplete components, a representation clause is
3844 -- illegal but stream attributes and Convention pragmas are correct.
3846 elsif Has_Private_Component (T) then
3847 if Nkind (N) = N_Pragma then
3851 ("representation item must appear after type is fully defined",
3858 end Rep_Item_Too_Early;
3860 -----------------------
3861 -- Rep_Item_Too_Late --
3862 -----------------------
3864 function Rep_Item_Too_Late
3867 FOnly : Boolean := False) return Boolean
3870 Parent_Type : Entity_Id;
3873 -- Output the too late message. Note that this is not considered a
3874 -- serious error, since the effect is simply that we ignore the
3875 -- representation clause in this case.
3881 procedure Too_Late is
3883 Error_Msg_N ("|representation item appears too late!", N);
3886 -- Start of processing for Rep_Item_Too_Late
3889 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
3890 -- types, which may be frozen if they appear in a representation clause
3891 -- for a local type.
3894 and then not From_With_Type (T)
3897 S := First_Subtype (T);
3899 if Present (Freeze_Node (S)) then
3901 ("?no more representation items for }", Freeze_Node (S), S);
3906 -- Check for case of non-tagged derived type whose parent either has
3907 -- primitive operations, or is a by reference type (RM 13.1(10)).
3911 and then Is_Derived_Type (T)
3912 and then not Is_Tagged_Type (T)
3914 Parent_Type := Etype (Base_Type (T));
3916 if Has_Primitive_Operations (Parent_Type) then
3919 ("primitive operations already defined for&!", N, Parent_Type);
3922 elsif Is_By_Reference_Type (Parent_Type) then
3925 ("parent type & is a by reference type!", N, Parent_Type);
3930 -- No error, link item into head of chain of rep items for the entity,
3931 -- but avoid chaining if we have an overloadable entity, and the pragma
3932 -- is one that can apply to multiple overloaded entities.
3934 if Is_Overloadable (T)
3935 and then Nkind (N) = N_Pragma
3938 Pname : constant Name_Id := Pragma_Name (N);
3940 if Pname = Name_Convention or else
3941 Pname = Name_Import or else
3942 Pname = Name_Export or else
3943 Pname = Name_External or else
3944 Pname = Name_Interface
3951 Record_Rep_Item (T, N);
3953 end Rep_Item_Too_Late;
3955 -------------------------
3956 -- Same_Representation --
3957 -------------------------
3959 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
3960 T1 : constant Entity_Id := Underlying_Type (Typ1);
3961 T2 : constant Entity_Id := Underlying_Type (Typ2);
3964 -- A quick check, if base types are the same, then we definitely have
3965 -- the same representation, because the subtype specific representation
3966 -- attributes (Size and Alignment) do not affect representation from
3967 -- the point of view of this test.
3969 if Base_Type (T1) = Base_Type (T2) then
3972 elsif Is_Private_Type (Base_Type (T2))
3973 and then Base_Type (T1) = Full_View (Base_Type (T2))
3978 -- Tagged types never have differing representations
3980 if Is_Tagged_Type (T1) then
3984 -- Representations are definitely different if conventions differ
3986 if Convention (T1) /= Convention (T2) then
3990 -- Representations are different if component alignments differ
3992 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
3994 (Is_Record_Type (T2) or else Is_Array_Type (T2))
3995 and then Component_Alignment (T1) /= Component_Alignment (T2)
4000 -- For arrays, the only real issue is component size. If we know the
4001 -- component size for both arrays, and it is the same, then that's
4002 -- good enough to know we don't have a change of representation.
4004 if Is_Array_Type (T1) then
4005 if Known_Component_Size (T1)
4006 and then Known_Component_Size (T2)
4007 and then Component_Size (T1) = Component_Size (T2)
4013 -- Types definitely have same representation if neither has non-standard
4014 -- representation since default representations are always consistent.
4015 -- If only one has non-standard representation, and the other does not,
4016 -- then we consider that they do not have the same representation. They
4017 -- might, but there is no way of telling early enough.
4019 if Has_Non_Standard_Rep (T1) then
4020 if not Has_Non_Standard_Rep (T2) then
4024 return not Has_Non_Standard_Rep (T2);
4027 -- Here the two types both have non-standard representation, and we need
4028 -- to determine if they have the same non-standard representation.
4030 -- For arrays, we simply need to test if the component sizes are the
4031 -- same. Pragma Pack is reflected in modified component sizes, so this
4032 -- check also deals with pragma Pack.
4034 if Is_Array_Type (T1) then
4035 return Component_Size (T1) = Component_Size (T2);
4037 -- Tagged types always have the same representation, because it is not
4038 -- possible to specify different representations for common fields.
4040 elsif Is_Tagged_Type (T1) then
4043 -- Case of record types
4045 elsif Is_Record_Type (T1) then
4047 -- Packed status must conform
4049 if Is_Packed (T1) /= Is_Packed (T2) then
4052 -- Otherwise we must check components. Typ2 maybe a constrained
4053 -- subtype with fewer components, so we compare the components
4054 -- of the base types.
4057 Record_Case : declare
4058 CD1, CD2 : Entity_Id;
4060 function Same_Rep return Boolean;
4061 -- CD1 and CD2 are either components or discriminants. This
4062 -- function tests whether the two have the same representation
4068 function Same_Rep return Boolean is
4070 if No (Component_Clause (CD1)) then
4071 return No (Component_Clause (CD2));
4075 Present (Component_Clause (CD2))
4077 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
4079 Esize (CD1) = Esize (CD2);
4083 -- Start of processing for Record_Case
4086 if Has_Discriminants (T1) then
4087 CD1 := First_Discriminant (T1);
4088 CD2 := First_Discriminant (T2);
4090 -- The number of discriminants may be different if the
4091 -- derived type has fewer (constrained by values). The
4092 -- invisible discriminants retain the representation of
4093 -- the original, so the discrepancy does not per se
4094 -- indicate a different representation.
4097 and then Present (CD2)
4099 if not Same_Rep then
4102 Next_Discriminant (CD1);
4103 Next_Discriminant (CD2);
4108 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
4109 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
4111 while Present (CD1) loop
4112 if not Same_Rep then
4115 Next_Component (CD1);
4116 Next_Component (CD2);
4124 -- For enumeration types, we must check each literal to see if the
4125 -- representation is the same. Note that we do not permit enumeration
4126 -- representation clauses for Character and Wide_Character, so these
4127 -- cases were already dealt with.
4129 elsif Is_Enumeration_Type (T1) then
4131 Enumeration_Case : declare
4135 L1 := First_Literal (T1);
4136 L2 := First_Literal (T2);
4138 while Present (L1) loop
4139 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
4149 end Enumeration_Case;
4151 -- Any other types have the same representation for these purposes
4156 end Same_Representation;
4158 --------------------
4159 -- Set_Enum_Esize --
4160 --------------------
4162 procedure Set_Enum_Esize (T : Entity_Id) is
4170 -- Find the minimum standard size (8,16,32,64) that fits
4172 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
4173 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
4176 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
4177 Sz := Standard_Character_Size; -- May be > 8 on some targets
4179 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
4182 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
4185 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
4190 if Hi < Uint_2**08 then
4191 Sz := Standard_Character_Size; -- May be > 8 on some targets
4193 elsif Hi < Uint_2**16 then
4196 elsif Hi < Uint_2**32 then
4199 else pragma Assert (Hi < Uint_2**63);
4204 -- That minimum is the proper size unless we have a foreign convention
4205 -- and the size required is 32 or less, in which case we bump the size
4206 -- up to 32. This is required for C and C++ and seems reasonable for
4207 -- all other foreign conventions.
4209 if Has_Foreign_Convention (T)
4210 and then Esize (T) < Standard_Integer_Size
4212 Init_Esize (T, Standard_Integer_Size);
4218 ------------------------------
4219 -- Validate_Address_Clauses --
4220 ------------------------------
4222 procedure Validate_Address_Clauses is
4224 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
4226 ACCR : Address_Clause_Check_Record
4227 renames Address_Clause_Checks.Table (J);
4238 -- Skip processing of this entry if warning already posted
4240 if not Address_Warning_Posted (ACCR.N) then
4242 Expr := Original_Node (Expression (ACCR.N));
4246 X_Alignment := Alignment (ACCR.X);
4247 Y_Alignment := Alignment (ACCR.Y);
4249 -- Similarly obtain sizes
4251 X_Size := Esize (ACCR.X);
4252 Y_Size := Esize (ACCR.Y);
4254 -- Check for large object overlaying smaller one
4257 and then X_Size > Uint_0
4258 and then X_Size > Y_Size
4261 ("?& overlays smaller object", ACCR.N, ACCR.X);
4263 ("\?program execution may be erroneous", ACCR.N);
4264 Error_Msg_Uint_1 := X_Size;
4266 ("\?size of & is ^", ACCR.N, ACCR.X);
4267 Error_Msg_Uint_1 := Y_Size;
4269 ("\?size of & is ^", ACCR.N, ACCR.Y);
4271 -- Check for inadequate alignment, both of the base object
4272 -- and of the offset, if any.
4274 -- Note: we do not check the alignment if we gave a size
4275 -- warning, since it would likely be redundant.
4277 elsif Y_Alignment /= Uint_0
4278 and then (Y_Alignment < X_Alignment
4281 Nkind (Expr) = N_Attribute_Reference
4283 Attribute_Name (Expr) = Name_Address
4285 Has_Compatible_Alignment
4286 (ACCR.X, Prefix (Expr))
4287 /= Known_Compatible))
4290 ("?specified address for& may be inconsistent "
4294 ("\?program execution may be erroneous (RM 13.3(27))",
4296 Error_Msg_Uint_1 := X_Alignment;
4298 ("\?alignment of & is ^",
4300 Error_Msg_Uint_1 := Y_Alignment;
4302 ("\?alignment of & is ^",
4304 if Y_Alignment >= X_Alignment then
4306 ("\?but offset is not multiple of alignment",
4313 end Validate_Address_Clauses;
4315 -----------------------------------
4316 -- Validate_Unchecked_Conversion --
4317 -----------------------------------
4319 procedure Validate_Unchecked_Conversion
4321 Act_Unit : Entity_Id)
4328 -- Obtain source and target types. Note that we call Ancestor_Subtype
4329 -- here because the processing for generic instantiation always makes
4330 -- subtypes, and we want the original frozen actual types.
4332 -- If we are dealing with private types, then do the check on their
4333 -- fully declared counterparts if the full declarations have been
4334 -- encountered (they don't have to be visible, but they must exist!)
4336 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
4338 if Is_Private_Type (Source)
4339 and then Present (Underlying_Type (Source))
4341 Source := Underlying_Type (Source);
4344 Target := Ancestor_Subtype (Etype (Act_Unit));
4346 -- If either type is generic, the instantiation happens within a generic
4347 -- unit, and there is nothing to check. The proper check
4348 -- will happen when the enclosing generic is instantiated.
4350 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
4354 if Is_Private_Type (Target)
4355 and then Present (Underlying_Type (Target))
4357 Target := Underlying_Type (Target);
4360 -- Source may be unconstrained array, but not target
4362 if Is_Array_Type (Target)
4363 and then not Is_Constrained (Target)
4366 ("unchecked conversion to unconstrained array not allowed", N);
4370 -- Warn if conversion between two different convention pointers
4372 if Is_Access_Type (Target)
4373 and then Is_Access_Type (Source)
4374 and then Convention (Target) /= Convention (Source)
4375 and then Warn_On_Unchecked_Conversion
4377 -- Give warnings for subprogram pointers only on most targets. The
4378 -- exception is VMS, where data pointers can have different lengths
4379 -- depending on the pointer convention.
4381 if Is_Access_Subprogram_Type (Target)
4382 or else Is_Access_Subprogram_Type (Source)
4383 or else OpenVMS_On_Target
4386 ("?conversion between pointers with different conventions!", N);
4390 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
4391 -- warning when compiling GNAT-related sources.
4393 if Warn_On_Unchecked_Conversion
4394 and then not In_Predefined_Unit (N)
4395 and then RTU_Loaded (Ada_Calendar)
4397 (Chars (Source) = Name_Time
4399 Chars (Target) = Name_Time)
4401 -- If Ada.Calendar is loaded and the name of one of the operands is
4402 -- Time, there is a good chance that this is Ada.Calendar.Time.
4405 Calendar_Time : constant Entity_Id :=
4406 Full_View (RTE (RO_CA_Time));
4408 pragma Assert (Present (Calendar_Time));
4410 if Source = Calendar_Time
4411 or else Target = Calendar_Time
4414 ("?representation of 'Time values may change between " &
4415 "'G'N'A'T versions", N);
4420 -- Make entry in unchecked conversion table for later processing by
4421 -- Validate_Unchecked_Conversions, which will check sizes and alignments
4422 -- (using values set by the back-end where possible). This is only done
4423 -- if the appropriate warning is active.
4425 if Warn_On_Unchecked_Conversion then
4426 Unchecked_Conversions.Append
4427 (New_Val => UC_Entry'
4432 -- If both sizes are known statically now, then back end annotation
4433 -- is not required to do a proper check but if either size is not
4434 -- known statically, then we need the annotation.
4436 if Known_Static_RM_Size (Source)
4437 and then Known_Static_RM_Size (Target)
4441 Back_Annotate_Rep_Info := True;
4445 -- If unchecked conversion to access type, and access type is declared
4446 -- in the same unit as the unchecked conversion, then set the
4447 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
4450 if Is_Access_Type (Target) and then
4451 In_Same_Source_Unit (Target, N)
4453 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
4456 -- Generate N_Validate_Unchecked_Conversion node for back end in
4457 -- case the back end needs to perform special validation checks.
4459 -- Shouldn't this be in Exp_Ch13, since the check only gets done
4460 -- if we have full expansion and the back end is called ???
4463 Make_Validate_Unchecked_Conversion (Sloc (N));
4464 Set_Source_Type (Vnode, Source);
4465 Set_Target_Type (Vnode, Target);
4467 -- If the unchecked conversion node is in a list, just insert before it.
4468 -- If not we have some strange case, not worth bothering about.
4470 if Is_List_Member (N) then
4471 Insert_After (N, Vnode);
4473 end Validate_Unchecked_Conversion;
4475 ------------------------------------
4476 -- Validate_Unchecked_Conversions --
4477 ------------------------------------
4479 procedure Validate_Unchecked_Conversions is
4481 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
4483 T : UC_Entry renames Unchecked_Conversions.Table (N);
4485 Eloc : constant Source_Ptr := T.Eloc;
4486 Source : constant Entity_Id := T.Source;
4487 Target : constant Entity_Id := T.Target;
4493 -- This validation check, which warns if we have unequal sizes for
4494 -- unchecked conversion, and thus potentially implementation
4495 -- dependent semantics, is one of the few occasions on which we
4496 -- use the official RM size instead of Esize. See description in
4497 -- Einfo "Handling of Type'Size Values" for details.
4499 if Serious_Errors_Detected = 0
4500 and then Known_Static_RM_Size (Source)
4501 and then Known_Static_RM_Size (Target)
4503 -- Don't do the check if warnings off for either type, note the
4504 -- deliberate use of OR here instead of OR ELSE to get the flag
4505 -- Warnings_Off_Used set for both types if appropriate.
4507 and then not (Has_Warnings_Off (Source)
4509 Has_Warnings_Off (Target))
4511 Source_Siz := RM_Size (Source);
4512 Target_Siz := RM_Size (Target);
4514 if Source_Siz /= Target_Siz then
4516 ("?types for unchecked conversion have different sizes!",
4519 if All_Errors_Mode then
4520 Error_Msg_Name_1 := Chars (Source);
4521 Error_Msg_Uint_1 := Source_Siz;
4522 Error_Msg_Name_2 := Chars (Target);
4523 Error_Msg_Uint_2 := Target_Siz;
4524 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
4526 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
4528 if Is_Discrete_Type (Source)
4529 and then Is_Discrete_Type (Target)
4531 if Source_Siz > Target_Siz then
4533 ("\?^ high order bits of source will be ignored!",
4536 elsif Is_Unsigned_Type (Source) then
4538 ("\?source will be extended with ^ high order " &
4539 "zero bits?!", Eloc);
4543 ("\?source will be extended with ^ high order " &
4548 elsif Source_Siz < Target_Siz then
4549 if Is_Discrete_Type (Target) then
4550 if Bytes_Big_Endian then
4552 ("\?target value will include ^ undefined " &
4557 ("\?target value will include ^ undefined " &
4564 ("\?^ trailing bits of target value will be " &
4565 "undefined!", Eloc);
4568 else pragma Assert (Source_Siz > Target_Siz);
4570 ("\?^ trailing bits of source will be ignored!",
4577 -- If both types are access types, we need to check the alignment.
4578 -- If the alignment of both is specified, we can do it here.
4580 if Serious_Errors_Detected = 0
4581 and then Ekind (Source) in Access_Kind
4582 and then Ekind (Target) in Access_Kind
4583 and then Target_Strict_Alignment
4584 and then Present (Designated_Type (Source))
4585 and then Present (Designated_Type (Target))
4588 D_Source : constant Entity_Id := Designated_Type (Source);
4589 D_Target : constant Entity_Id := Designated_Type (Target);
4592 if Known_Alignment (D_Source)
4593 and then Known_Alignment (D_Target)
4596 Source_Align : constant Uint := Alignment (D_Source);
4597 Target_Align : constant Uint := Alignment (D_Target);
4600 if Source_Align < Target_Align
4601 and then not Is_Tagged_Type (D_Source)
4603 -- Suppress warning if warnings suppressed on either
4604 -- type or either designated type. Note the use of
4605 -- OR here instead of OR ELSE. That is intentional,
4606 -- we would like to set flag Warnings_Off_Used in
4607 -- all types for which warnings are suppressed.
4609 and then not (Has_Warnings_Off (D_Source)
4611 Has_Warnings_Off (D_Target)
4613 Has_Warnings_Off (Source)
4615 Has_Warnings_Off (Target))
4617 Error_Msg_Uint_1 := Target_Align;
4618 Error_Msg_Uint_2 := Source_Align;
4619 Error_Msg_Node_1 := D_Target;
4620 Error_Msg_Node_2 := D_Source;
4622 ("?alignment of & (^) is stricter than " &
4623 "alignment of & (^)!", Eloc);
4625 ("\?resulting access value may have invalid " &
4626 "alignment!", Eloc);
4634 end Validate_Unchecked_Conversions;