1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Disp; use Exp_Disp;
33 with Exp_Tss; use Exp_Tss;
34 with Exp_Util; use Exp_Util;
36 with Lib.Xref; use Lib.Xref;
37 with Namet; use Namet;
38 with Nlists; use Nlists;
39 with Nmake; use Nmake;
41 with Restrict; use Restrict;
42 with Rident; use Rident;
43 with Rtsfind; use Rtsfind;
45 with Sem_Aux; use Sem_Aux;
46 with Sem_Ch3; use Sem_Ch3;
47 with Sem_Ch8; use Sem_Ch8;
48 with Sem_Eval; use Sem_Eval;
49 with Sem_Res; use Sem_Res;
50 with Sem_Type; use Sem_Type;
51 with Sem_Util; use Sem_Util;
52 with Sem_Warn; use Sem_Warn;
53 with Sinput; use Sinput;
54 with Snames; use Snames;
55 with Stand; use Stand;
56 with Sinfo; use Sinfo;
57 with Stringt; use Stringt;
58 with Targparm; use Targparm;
59 with Ttypes; use Ttypes;
60 with Tbuild; use Tbuild;
61 with Urealp; use Urealp;
63 with GNAT.Heap_Sort_G;
65 package body Sem_Ch13 is
67 SSU : constant Pos := System_Storage_Unit;
68 -- Convenient short hand for commonly used constant
70 -----------------------
71 -- Local Subprograms --
72 -----------------------
74 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
75 -- This routine is called after setting the Esize of type entity Typ.
76 -- The purpose is to deal with the situation where an alignment has been
77 -- inherited from a derived type that is no longer appropriate for the
78 -- new Esize value. In this case, we reset the Alignment to unknown.
80 procedure Build_Predicate_Function
84 -- If Typ has predicates (indicated by Has_Predicates being set for Typ,
85 -- then either there are pragma Invariant entries on the rep chain for the
86 -- type (note that Predicate aspects are converted to pragam Predicate), or
87 -- there are inherited aspects from a parent type, or ancestor subtypes,
88 -- or interfaces. This procedure builds the spec and body for the Predicate
89 -- function that tests these predicates, returning them in PDecl and Pbody
90 -- and setting Predicate_Procedure for Typ. In some error situations no
91 -- procedure is built, in which case PDecl/PBody are empty on return.
93 procedure Build_Static_Predicate
97 -- Given a predicated type Typ, where Typ is a discrete static subtype,
98 -- whose predicate expression is Expr, tests if Expr is a static predicate,
99 -- and if so, builds the predicate range list. Nam is the name of the one
100 -- argument to the predicate function. Occurrences of the type name in the
101 -- predicate expression have been replaced by identifer references to this
102 -- name, which is unique, so any identifier with Chars matching Nam must be
103 -- a reference to the type. If the predicate is non-static, this procedure
104 -- returns doing nothing. If the predicate is static, then the predicate
105 -- list is stored in Static_Predicate (Typ), and the Expr is rewritten as
106 -- a canonicalized membership operation.
108 function Get_Alignment_Value (Expr : Node_Id) return Uint;
109 -- Given the expression for an alignment value, returns the corresponding
110 -- Uint value. If the value is inappropriate, then error messages are
111 -- posted as required, and a value of No_Uint is returned.
113 function Is_Operational_Item (N : Node_Id) return Boolean;
114 -- A specification for a stream attribute is allowed before the full type
115 -- is declared, as explained in AI-00137 and the corrigendum. Attributes
116 -- that do not specify a representation characteristic are operational
119 procedure New_Stream_Subprogram
123 Nam : TSS_Name_Type);
124 -- Create a subprogram renaming of a given stream attribute to the
125 -- designated subprogram and then in the tagged case, provide this as a
126 -- primitive operation, or in the non-tagged case make an appropriate TSS
127 -- entry. This is more properly an expansion activity than just semantics,
128 -- but the presence of user-defined stream functions for limited types is a
129 -- legality check, which is why this takes place here rather than in
130 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
131 -- function to be generated.
133 -- To avoid elaboration anomalies with freeze nodes, for untagged types
134 -- we generate both a subprogram declaration and a subprogram renaming
135 -- declaration, so that the attribute specification is handled as a
136 -- renaming_as_body. For tagged types, the specification is one of the
143 Biased : Boolean := True);
144 -- If Biased is True, sets Has_Biased_Representation flag for E, and
145 -- outputs a warning message at node N if Warn_On_Biased_Representation is
146 -- is True. This warning inserts the string Msg to describe the construct
149 ----------------------------------------------
150 -- Table for Validate_Unchecked_Conversions --
151 ----------------------------------------------
153 -- The following table collects unchecked conversions for validation.
154 -- Entries are made by Validate_Unchecked_Conversion and then the
155 -- call to Validate_Unchecked_Conversions does the actual error
156 -- checking and posting of warnings. The reason for this delayed
157 -- processing is to take advantage of back-annotations of size and
158 -- alignment values performed by the back end.
160 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
161 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
162 -- will already have modified all Sloc values if the -gnatD option is set.
164 type UC_Entry is record
165 Eloc : Source_Ptr; -- node used for posting warnings
166 Source : Entity_Id; -- source type for unchecked conversion
167 Target : Entity_Id; -- target type for unchecked conversion
170 package Unchecked_Conversions is new Table.Table (
171 Table_Component_Type => UC_Entry,
172 Table_Index_Type => Int,
173 Table_Low_Bound => 1,
175 Table_Increment => 200,
176 Table_Name => "Unchecked_Conversions");
178 ----------------------------------------
179 -- Table for Validate_Address_Clauses --
180 ----------------------------------------
182 -- If an address clause has the form
184 -- for X'Address use Expr
186 -- where Expr is of the form Y'Address or recursively is a reference
187 -- to a constant of either of these forms, and X and Y are entities of
188 -- objects, then if Y has a smaller alignment than X, that merits a
189 -- warning about possible bad alignment. The following table collects
190 -- address clauses of this kind. We put these in a table so that they
191 -- can be checked after the back end has completed annotation of the
192 -- alignments of objects, since we can catch more cases that way.
194 type Address_Clause_Check_Record is record
196 -- The address clause
199 -- The entity of the object overlaying Y
202 -- The entity of the object being overlaid
205 -- Whether the address is offseted within Y
208 package Address_Clause_Checks is new Table.Table (
209 Table_Component_Type => Address_Clause_Check_Record,
210 Table_Index_Type => Int,
211 Table_Low_Bound => 1,
213 Table_Increment => 200,
214 Table_Name => "Address_Clause_Checks");
216 -----------------------------------------
217 -- Adjust_Record_For_Reverse_Bit_Order --
218 -----------------------------------------
220 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
225 -- Processing depends on version of Ada
227 -- For Ada 95, we just renumber bits within a storage unit. We do the
228 -- same for Ada 83 mode, since we recognize pragma Bit_Order in Ada 83,
229 -- and are free to add this extension.
231 if Ada_Version < Ada_2005 then
232 Comp := First_Component_Or_Discriminant (R);
233 while Present (Comp) loop
234 CC := Component_Clause (Comp);
236 -- If component clause is present, then deal with the non-default
237 -- bit order case for Ada 95 mode.
239 -- We only do this processing for the base type, and in fact that
240 -- is important, since otherwise if there are record subtypes, we
241 -- could reverse the bits once for each subtype, which is wrong.
244 and then Ekind (R) = E_Record_Type
247 CFB : constant Uint := Component_Bit_Offset (Comp);
248 CSZ : constant Uint := Esize (Comp);
249 CLC : constant Node_Id := Component_Clause (Comp);
250 Pos : constant Node_Id := Position (CLC);
251 FB : constant Node_Id := First_Bit (CLC);
253 Storage_Unit_Offset : constant Uint :=
254 CFB / System_Storage_Unit;
256 Start_Bit : constant Uint :=
257 CFB mod System_Storage_Unit;
260 -- Cases where field goes over storage unit boundary
262 if Start_Bit + CSZ > System_Storage_Unit then
264 -- Allow multi-byte field but generate warning
266 if Start_Bit mod System_Storage_Unit = 0
267 and then CSZ mod System_Storage_Unit = 0
270 ("multi-byte field specified with non-standard"
271 & " Bit_Order?", CLC);
273 if Bytes_Big_Endian then
275 ("bytes are not reversed "
276 & "(component is big-endian)?", CLC);
279 ("bytes are not reversed "
280 & "(component is little-endian)?", CLC);
283 -- Do not allow non-contiguous field
287 ("attempt to specify non-contiguous field "
288 & "not permitted", CLC);
290 ("\caused by non-standard Bit_Order "
293 ("\consider possibility of using "
294 & "Ada 2005 mode here", CLC);
297 -- Case where field fits in one storage unit
300 -- Give warning if suspicious component clause
302 if Intval (FB) >= System_Storage_Unit
303 and then Warn_On_Reverse_Bit_Order
306 ("?Bit_Order clause does not affect " &
307 "byte ordering", Pos);
309 Intval (Pos) + Intval (FB) /
312 ("?position normalized to ^ before bit " &
313 "order interpreted", Pos);
316 -- Here is where we fix up the Component_Bit_Offset value
317 -- to account for the reverse bit order. Some examples of
318 -- what needs to be done are:
320 -- First_Bit .. Last_Bit Component_Bit_Offset
332 -- The rule is that the first bit is is obtained by
333 -- subtracting the old ending bit from storage_unit - 1.
335 Set_Component_Bit_Offset
337 (Storage_Unit_Offset * System_Storage_Unit) +
338 (System_Storage_Unit - 1) -
339 (Start_Bit + CSZ - 1));
341 Set_Normalized_First_Bit
343 Component_Bit_Offset (Comp) mod
344 System_Storage_Unit);
349 Next_Component_Or_Discriminant (Comp);
352 -- For Ada 2005, we do machine scalar processing, as fully described In
353 -- AI-133. This involves gathering all components which start at the
354 -- same byte offset and processing them together. Same approach is still
355 -- valid in later versions including Ada 2012.
359 Max_Machine_Scalar_Size : constant Uint :=
361 (Standard_Long_Long_Integer_Size);
362 -- We use this as the maximum machine scalar size
365 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
368 -- This first loop through components does two things. First it
369 -- deals with the case of components with component clauses whose
370 -- length is greater than the maximum machine scalar size (either
371 -- accepting them or rejecting as needed). Second, it counts the
372 -- number of components with component clauses whose length does
373 -- not exceed this maximum for later processing.
376 Comp := First_Component_Or_Discriminant (R);
377 while Present (Comp) loop
378 CC := Component_Clause (Comp);
382 Fbit : constant Uint :=
383 Static_Integer (First_Bit (CC));
386 -- Case of component with size > max machine scalar
388 if Esize (Comp) > Max_Machine_Scalar_Size then
390 -- Must begin on byte boundary
392 if Fbit mod SSU /= 0 then
394 ("illegal first bit value for "
395 & "reverse bit order",
397 Error_Msg_Uint_1 := SSU;
398 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
401 ("\must be a multiple of ^ "
402 & "if size greater than ^",
405 -- Must end on byte boundary
407 elsif Esize (Comp) mod SSU /= 0 then
409 ("illegal last bit value for "
410 & "reverse bit order",
412 Error_Msg_Uint_1 := SSU;
413 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
416 ("\must be a multiple of ^ if size "
420 -- OK, give warning if enabled
422 elsif Warn_On_Reverse_Bit_Order then
424 ("multi-byte field specified with "
425 & " non-standard Bit_Order?", CC);
427 if Bytes_Big_Endian then
429 ("\bytes are not reversed "
430 & "(component is big-endian)?", CC);
433 ("\bytes are not reversed "
434 & "(component is little-endian)?", CC);
438 -- Case where size is not greater than max machine
439 -- scalar. For now, we just count these.
442 Num_CC := Num_CC + 1;
447 Next_Component_Or_Discriminant (Comp);
450 -- We need to sort the component clauses on the basis of the
451 -- Position values in the clause, so we can group clauses with
452 -- the same Position. together to determine the relevant machine
456 Comps : array (0 .. Num_CC) of Entity_Id;
457 -- Array to collect component and discriminant entities. The
458 -- data starts at index 1, the 0'th entry is for the sort
461 function CP_Lt (Op1, Op2 : Natural) return Boolean;
462 -- Compare routine for Sort
464 procedure CP_Move (From : Natural; To : Natural);
465 -- Move routine for Sort
467 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
471 -- Start and stop positions in the component list of the set of
472 -- components with the same starting position (that constitute
473 -- components in a single machine scalar).
476 -- Maximum last bit value of any component in this set
479 -- Corresponding machine scalar size
485 function CP_Lt (Op1, Op2 : Natural) return Boolean is
487 return Position (Component_Clause (Comps (Op1))) <
488 Position (Component_Clause (Comps (Op2)));
495 procedure CP_Move (From : Natural; To : Natural) is
497 Comps (To) := Comps (From);
500 -- Start of processing for Sort_CC
503 -- Collect the component clauses
506 Comp := First_Component_Or_Discriminant (R);
507 while Present (Comp) loop
508 if Present (Component_Clause (Comp))
509 and then Esize (Comp) <= Max_Machine_Scalar_Size
511 Num_CC := Num_CC + 1;
512 Comps (Num_CC) := Comp;
515 Next_Component_Or_Discriminant (Comp);
518 -- Sort by ascending position number
520 Sorting.Sort (Num_CC);
522 -- We now have all the components whose size does not exceed
523 -- the max machine scalar value, sorted by starting position.
524 -- In this loop we gather groups of clauses starting at the
525 -- same position, to process them in accordance with AI-133.
528 while Stop < Num_CC loop
533 (Last_Bit (Component_Clause (Comps (Start))));
534 while Stop < Num_CC loop
536 (Position (Component_Clause (Comps (Stop + 1)))) =
538 (Position (Component_Clause (Comps (Stop))))
546 (Component_Clause (Comps (Stop)))));
552 -- Now we have a group of component clauses from Start to
553 -- Stop whose positions are identical, and MaxL is the
554 -- maximum last bit value of any of these components.
556 -- We need to determine the corresponding machine scalar
557 -- size. This loop assumes that machine scalar sizes are
558 -- even, and that each possible machine scalar has twice
559 -- as many bits as the next smaller one.
561 MSS := Max_Machine_Scalar_Size;
563 and then (MSS / 2) >= SSU
564 and then (MSS / 2) > MaxL
569 -- Here is where we fix up the Component_Bit_Offset value
570 -- to account for the reverse bit order. Some examples of
571 -- what needs to be done for the case of a machine scalar
574 -- First_Bit .. Last_Bit Component_Bit_Offset
586 -- The rule is that the first bit is obtained by subtracting
587 -- the old ending bit from machine scalar size - 1.
589 for C in Start .. Stop loop
591 Comp : constant Entity_Id := Comps (C);
592 CC : constant Node_Id :=
593 Component_Clause (Comp);
594 LB : constant Uint :=
595 Static_Integer (Last_Bit (CC));
596 NFB : constant Uint := MSS - Uint_1 - LB;
597 NLB : constant Uint := NFB + Esize (Comp) - 1;
598 Pos : constant Uint :=
599 Static_Integer (Position (CC));
602 if Warn_On_Reverse_Bit_Order then
603 Error_Msg_Uint_1 := MSS;
605 ("info: reverse bit order in machine " &
606 "scalar of length^?", First_Bit (CC));
607 Error_Msg_Uint_1 := NFB;
608 Error_Msg_Uint_2 := NLB;
610 if Bytes_Big_Endian then
612 ("?\info: big-endian range for "
613 & "component & is ^ .. ^",
614 First_Bit (CC), Comp);
617 ("?\info: little-endian range "
618 & "for component & is ^ .. ^",
619 First_Bit (CC), Comp);
623 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
624 Set_Normalized_First_Bit (Comp, NFB mod SSU);
631 end Adjust_Record_For_Reverse_Bit_Order;
633 --------------------------------------
634 -- Alignment_Check_For_Esize_Change --
635 --------------------------------------
637 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
639 -- If the alignment is known, and not set by a rep clause, and is
640 -- inconsistent with the size being set, then reset it to unknown,
641 -- we assume in this case that the size overrides the inherited
642 -- alignment, and that the alignment must be recomputed.
644 if Known_Alignment (Typ)
645 and then not Has_Alignment_Clause (Typ)
646 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
648 Init_Alignment (Typ);
650 end Alignment_Check_For_Esize_Change;
652 -----------------------------------
653 -- Analyze_Aspect_Specifications --
654 -----------------------------------
656 procedure Analyze_Aspect_Specifications
665 Ins_Node : Node_Id := N;
666 -- Insert pragmas (except Pre/Post/Invariant/Predicate) after this node
668 -- The general processing involves building an attribute definition
669 -- clause or a pragma node that corresponds to the access type. Then
670 -- one of two things happens:
672 -- If we are required to delay the evaluation of this aspect to the
673 -- freeze point, we preanalyze the relevant argument, and then attach
674 -- the corresponding pragma/attribute definition clause to the aspect
675 -- specification node, which is then placed in the Rep Item chain.
676 -- In this case we mark the entity with the Has_Delayed_Aspects flag,
677 -- and we evaluate the rep item at the freeze point.
679 -- If no delay is required, we just insert the pragma or attribute
680 -- after the declaration, and it will get processed by the normal
681 -- circuit. The From_Aspect_Specification flag is set on the pragma
682 -- or attribute definition node in either case to activate special
683 -- processing (e.g. not traversing the list of homonyms for inline).
685 Delay_Required : Boolean;
686 -- Set True if delay is required
689 -- Return if no aspects
695 -- Return if already analyzed (avoids duplicate calls in some cases
696 -- where type declarations get rewritten and proessed twice).
702 -- Loop through apsects
705 while Present (Aspect) loop
707 Loc : constant Source_Ptr := Sloc (Aspect);
708 Id : constant Node_Id := Identifier (Aspect);
709 Expr : constant Node_Id := Expression (Aspect);
710 Nam : constant Name_Id := Chars (Id);
711 A_Id : constant Aspect_Id := Get_Aspect_Id (Nam);
715 Eloc : Source_Ptr := Sloc (Expr);
716 -- Source location of expression, modified when we split PPC's
719 Set_Entity (Aspect, E);
720 Ent := New_Occurrence_Of (E, Sloc (Id));
722 -- Check for duplicate aspect. Note that the Comes_From_Source
723 -- test allows duplicate Pre/Post's that we generate internally
724 -- to escape being flagged here.
727 while Anod /= Aspect loop
728 if Nam = Chars (Identifier (Anod))
729 and then Comes_From_Source (Aspect)
731 Error_Msg_Name_1 := Nam;
732 Error_Msg_Sloc := Sloc (Anod);
734 -- Case of same aspect specified twice
736 if Class_Present (Anod) = Class_Present (Aspect) then
737 if not Class_Present (Anod) then
739 ("aspect% for & previously given#",
743 ("aspect `%''Class` for & previously given#",
747 -- Case of Pre and Pre'Class both specified
749 elsif Nam = Name_Pre then
750 if Class_Present (Aspect) then
752 ("aspect `Pre''Class` for & is not allowed here",
755 ("\since aspect `Pre` previously given#",
760 ("aspect `Pre` for & is not allowed here",
763 ("\since aspect `Pre''Class` previously given#",
774 -- Processing based on specific aspect
778 -- No_Aspect should be impossible
783 -- Aspects taking an optional boolean argument. For all of
784 -- these we just create a matching pragma and insert it,
785 -- setting flag Cancel_Aspect if the expression is False.
787 when Aspect_Ada_2005 |
790 Aspect_Atomic_Components |
791 Aspect_Discard_Names |
792 Aspect_Favor_Top_Level |
794 Aspect_Inline_Always |
797 Aspect_Persistent_BSS |
798 Aspect_Preelaborable_Initialization |
799 Aspect_Pure_Function |
801 Aspect_Suppress_Debug_Info |
802 Aspect_Unchecked_Union |
803 Aspect_Universal_Aliasing |
805 Aspect_Unreferenced |
806 Aspect_Unreferenced_Objects |
808 Aspect_Volatile_Components =>
810 -- Build corresponding pragma node
814 Pragma_Argument_Associations => New_List (Ent),
816 Make_Identifier (Sloc (Id), Chars (Id)));
818 -- Deal with missing expression case, delay never needed
821 Delay_Required := False;
823 -- Expression is present
826 Preanalyze_Spec_Expression (Expr, Standard_Boolean);
828 -- If preanalysis gives a static expression, we don't
829 -- need to delay (this will happen often in practice).
831 if Is_OK_Static_Expression (Expr) then
832 Delay_Required := False;
834 if Is_False (Expr_Value (Expr)) then
835 Set_Aspect_Cancel (Aitem);
838 -- If we don't get a static expression, then delay, the
839 -- expression may turn out static by freeze time.
842 Delay_Required := True;
846 -- Aspects corresponding to attribute definition clauses
848 when Aspect_Address |
851 Aspect_Component_Size |
852 Aspect_External_Tag |
853 Aspect_Machine_Radix |
856 Aspect_Storage_Pool |
857 Aspect_Storage_Size |
861 -- Preanalyze the expression with the appropriate type
864 when Aspect_Address =>
865 T := RTE (RE_Address);
866 when Aspect_Bit_Order =>
867 T := RTE (RE_Bit_Order);
868 when Aspect_External_Tag =>
869 T := Standard_String;
870 when Aspect_Storage_Pool =>
871 T := Class_Wide_Type (RTE (RE_Root_Storage_Pool));
876 Preanalyze_Spec_Expression (Expr, T);
878 -- Construct the attribute definition clause
881 Make_Attribute_Definition_Clause (Loc,
884 Expression => Relocate_Node (Expr));
886 -- We do not need a delay if we have a static expression
888 if Is_OK_Static_Expression (Expression (Aitem)) then
889 Delay_Required := False;
891 -- Here a delay is required
894 Delay_Required := True;
897 -- Aspects corresponding to pragmas with two arguments, where
898 -- the first argument is a local name referring to the entity,
899 -- and the second argument is the aspect definition expression.
901 when Aspect_Suppress |
904 -- Construct the pragma
908 Pragma_Argument_Associations => New_List (
909 New_Occurrence_Of (E, Eloc),
910 Relocate_Node (Expr)),
912 Make_Identifier (Sloc (Id), Chars (Id)));
914 -- We don't have to play the delay game here, since the only
915 -- values are check names which don't get analyzed anyway.
917 Delay_Required := False;
919 -- Aspects corresponding to stream routines
926 -- Construct the attribute definition clause
929 Make_Attribute_Definition_Clause (Loc,
932 Expression => Relocate_Node (Expr));
934 -- These are always delayed (typically the subprogram that
935 -- is referenced cannot have been declared yet, since it has
936 -- a reference to the type for which this aspect is defined.
938 Delay_Required := True;
940 -- Aspects corresponding to pragmas with two arguments, where
941 -- the second argument is a local name referring to the entity,
942 -- and the first argument is the aspect definition expression.
944 when Aspect_Warnings =>
946 -- Construct the pragma
950 Pragma_Argument_Associations => New_List (
951 Relocate_Node (Expr),
952 New_Occurrence_Of (E, Eloc)),
954 Make_Identifier (Sloc (Id), Chars (Id)),
955 Class_Present => Class_Present (Aspect));
957 -- We don't have to play the delay game here, since the only
958 -- values are check names which don't get analyzed anyway.
960 Delay_Required := False;
962 -- Aspects Pre/Post generate Precondition/Postcondition pragmas
963 -- with a first argument that is the expression, and a second
964 -- argument that is an informative message if the test fails.
965 -- This is inserted right after the declaration, to get the
966 -- required pragma placement. The processing for the pragmas
967 -- takes care of the required delay.
969 when Aspect_Pre | Aspect_Post => declare
973 if A_Id = Aspect_Pre then
974 Pname := Name_Precondition;
976 Pname := Name_Postcondition;
979 -- If the expressions is of the form A and then B, then
980 -- we generate separate Pre/Post aspects for the separate
981 -- clauses. Since we allow multiple pragmas, there is no
982 -- problem in allowing multiple Pre/Post aspects internally.
984 -- We do not do this for Pre'Class, since we have to put
985 -- these conditions together in a complex OR expression
987 if Pname = Name_Postcondition
988 or else not Class_Present (Aspect)
990 while Nkind (Expr) = N_And_Then loop
991 Insert_After (Aspect,
992 Make_Aspect_Specification (Sloc (Right_Opnd (Expr)),
993 Identifier => Identifier (Aspect),
994 Expression => Relocate_Node (Right_Opnd (Expr)),
995 Class_Present => Class_Present (Aspect),
997 Rewrite (Expr, Relocate_Node (Left_Opnd (Expr)));
1002 -- Build the precondition/postcondition pragma
1006 Pragma_Identifier =>
1007 Make_Identifier (Sloc (Id),
1009 Class_Present => Class_Present (Aspect),
1010 Split_PPC => Split_PPC (Aspect),
1011 Pragma_Argument_Associations => New_List (
1012 Make_Pragma_Argument_Association (Eloc,
1013 Chars => Name_Check,
1014 Expression => Relocate_Node (Expr))));
1016 -- Add message unless exception messages are suppressed
1018 if not Opt.Exception_Locations_Suppressed then
1019 Append_To (Pragma_Argument_Associations (Aitem),
1020 Make_Pragma_Argument_Association (Eloc,
1021 Chars => Name_Message,
1023 Make_String_Literal (Eloc,
1025 & Get_Name_String (Pname)
1027 & Build_Location_String (Eloc))));
1030 Set_From_Aspect_Specification (Aitem, True);
1032 -- For Pre/Post cases, insert immediately after the entity
1033 -- declaration, since that is the required pragma placement.
1034 -- Note that for these aspects, we do not have to worry
1035 -- about delay issues, since the pragmas themselves deal
1036 -- with delay of visibility for the expression analysis.
1038 -- If the entity is a library-level subprogram, the pre/
1039 -- postconditions must be treated as late pragmas.
1041 if Nkind (Parent (N)) = N_Compilation_Unit then
1042 Add_Global_Declaration (Aitem);
1044 Insert_After (N, Aitem);
1050 -- Invariant aspects generate a corresponding pragma with a
1051 -- first argument that is the entity, and the second argument
1052 -- is the expression and anthird argument with an appropriate
1053 -- message. This is inserted right after the declaration, to
1054 -- get the required pragma placement. The pragma processing
1055 -- takes care of the required delay.
1057 when Aspect_Invariant =>
1059 -- Construct the pragma
1063 Pragma_Argument_Associations =>
1064 New_List (Ent, Relocate_Node (Expr)),
1065 Class_Present => Class_Present (Aspect),
1066 Pragma_Identifier =>
1067 Make_Identifier (Sloc (Id), Name_Invariant));
1069 -- Add message unless exception messages are suppressed
1071 if not Opt.Exception_Locations_Suppressed then
1072 Append_To (Pragma_Argument_Associations (Aitem),
1073 Make_Pragma_Argument_Association (Eloc,
1074 Chars => Name_Message,
1076 Make_String_Literal (Eloc,
1077 Strval => "failed invariant from "
1078 & Build_Location_String (Eloc))));
1081 Set_From_Aspect_Specification (Aitem, True);
1083 -- For Invariant case, insert immediately after the entity
1084 -- declaration. We do not have to worry about delay issues
1085 -- since the pragma processing takes care of this.
1087 Insert_After (N, Aitem);
1090 -- Predicate aspects generate a corresponding pragma with a
1091 -- first argument that is the entity, and the second argument
1092 -- is the expression. This is inserted immediately after the
1093 -- declaration, to get the required pragma placement. The
1094 -- pragma processing takes care of the required delay.
1096 when Aspect_Predicate =>
1098 -- Construct the pragma
1102 Pragma_Argument_Associations =>
1103 New_List (Ent, Relocate_Node (Expr)),
1104 Class_Present => Class_Present (Aspect),
1105 Pragma_Identifier =>
1106 Make_Identifier (Sloc (Id), Name_Predicate));
1108 Set_From_Aspect_Specification (Aitem, True);
1110 -- Make sure we have a freeze node (it might otherwise be
1111 -- missing in cases like subtype X is Y, and we would not
1112 -- have a place to build the predicate function).
1114 Ensure_Freeze_Node (E);
1116 -- For Predicate case, insert immediately after the entity
1117 -- declaration. We do not have to worry about delay issues
1118 -- since the pragma processing takes care of this.
1120 Insert_After (N, Aitem);
1124 Set_From_Aspect_Specification (Aitem, True);
1126 -- If a delay is required, we delay the freeze (not much point in
1127 -- delaying the aspect if we don't delay the freeze!). The pragma
1128 -- or clause is then attached to the aspect specification which
1129 -- is placed in the rep item list.
1131 if Delay_Required then
1132 Ensure_Freeze_Node (E);
1133 Set_Is_Delayed_Aspect (Aitem);
1134 Set_Has_Delayed_Aspects (E);
1135 Set_Aspect_Rep_Item (Aspect, Aitem);
1136 Record_Rep_Item (E, Aspect);
1138 -- If no delay required, insert the pragma/clause in the tree
1141 -- For Pre/Post cases, insert immediately after the entity
1142 -- declaration, since that is the required pragma placement.
1144 if A_Id = Aspect_Pre or else A_Id = Aspect_Post then
1145 Insert_After (N, Aitem);
1147 -- For all other cases, insert in sequence
1150 Insert_After (Ins_Node, Aitem);
1159 end Analyze_Aspect_Specifications;
1161 -----------------------
1162 -- Analyze_At_Clause --
1163 -----------------------
1165 -- An at clause is replaced by the corresponding Address attribute
1166 -- definition clause that is the preferred approach in Ada 95.
1168 procedure Analyze_At_Clause (N : Node_Id) is
1169 CS : constant Boolean := Comes_From_Source (N);
1172 -- This is an obsolescent feature
1174 Check_Restriction (No_Obsolescent_Features, N);
1176 if Warn_On_Obsolescent_Feature then
1178 ("at clause is an obsolescent feature (RM J.7(2))?", N);
1180 ("\use address attribute definition clause instead?", N);
1183 -- Rewrite as address clause
1186 Make_Attribute_Definition_Clause (Sloc (N),
1187 Name => Identifier (N),
1188 Chars => Name_Address,
1189 Expression => Expression (N)));
1191 -- We preserve Comes_From_Source, since logically the clause still
1192 -- comes from the source program even though it is changed in form.
1194 Set_Comes_From_Source (N, CS);
1196 -- Analyze rewritten clause
1198 Analyze_Attribute_Definition_Clause (N);
1199 end Analyze_At_Clause;
1201 -----------------------------------------
1202 -- Analyze_Attribute_Definition_Clause --
1203 -----------------------------------------
1205 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
1206 Loc : constant Source_Ptr := Sloc (N);
1207 Nam : constant Node_Id := Name (N);
1208 Attr : constant Name_Id := Chars (N);
1209 Expr : constant Node_Id := Expression (N);
1210 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
1214 FOnly : Boolean := False;
1215 -- Reset to True for subtype specific attribute (Alignment, Size)
1216 -- and for stream attributes, i.e. those cases where in the call
1217 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
1218 -- rules are checked. Note that the case of stream attributes is not
1219 -- clear from the RM, but see AI95-00137. Also, the RM seems to
1220 -- disallow Storage_Size for derived task types, but that is also
1221 -- clearly unintentional.
1223 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
1224 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
1225 -- definition clauses.
1227 function Duplicate_Clause return Boolean;
1228 -- This routine checks if the aspect for U_Ent being given by attribute
1229 -- definition clause N is for an aspect that has already been specified,
1230 -- and if so gives an error message. If there is a duplicate, True is
1231 -- returned, otherwise if there is no error, False is returned.
1233 -----------------------------------
1234 -- Analyze_Stream_TSS_Definition --
1235 -----------------------------------
1237 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
1238 Subp : Entity_Id := Empty;
1243 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
1245 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
1246 -- Return true if the entity is a subprogram with an appropriate
1247 -- profile for the attribute being defined.
1249 ----------------------
1250 -- Has_Good_Profile --
1251 ----------------------
1253 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
1255 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
1256 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
1257 (False => E_Procedure, True => E_Function);
1261 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
1265 F := First_Formal (Subp);
1268 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
1269 or else Designated_Type (Etype (F)) /=
1270 Class_Wide_Type (RTE (RE_Root_Stream_Type))
1275 if not Is_Function then
1279 Expected_Mode : constant array (Boolean) of Entity_Kind :=
1280 (False => E_In_Parameter,
1281 True => E_Out_Parameter);
1283 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
1291 Typ := Etype (Subp);
1294 return Base_Type (Typ) = Base_Type (Ent)
1295 and then No (Next_Formal (F));
1296 end Has_Good_Profile;
1298 -- Start of processing for Analyze_Stream_TSS_Definition
1303 if not Is_Type (U_Ent) then
1304 Error_Msg_N ("local name must be a subtype", Nam);
1308 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
1310 -- If Pnam is present, it can be either inherited from an ancestor
1311 -- type (in which case it is legal to redefine it for this type), or
1312 -- be a previous definition of the attribute for the same type (in
1313 -- which case it is illegal).
1315 -- In the first case, it will have been analyzed already, and we
1316 -- can check that its profile does not match the expected profile
1317 -- for a stream attribute of U_Ent. In the second case, either Pnam
1318 -- has been analyzed (and has the expected profile), or it has not
1319 -- been analyzed yet (case of a type that has not been frozen yet
1320 -- and for which the stream attribute has been set using Set_TSS).
1323 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
1325 Error_Msg_Sloc := Sloc (Pnam);
1326 Error_Msg_Name_1 := Attr;
1327 Error_Msg_N ("% attribute already defined #", Nam);
1333 if Is_Entity_Name (Expr) then
1334 if not Is_Overloaded (Expr) then
1335 if Has_Good_Profile (Entity (Expr)) then
1336 Subp := Entity (Expr);
1340 Get_First_Interp (Expr, I, It);
1341 while Present (It.Nam) loop
1342 if Has_Good_Profile (It.Nam) then
1347 Get_Next_Interp (I, It);
1352 if Present (Subp) then
1353 if Is_Abstract_Subprogram (Subp) then
1354 Error_Msg_N ("stream subprogram must not be abstract", Expr);
1358 Set_Entity (Expr, Subp);
1359 Set_Etype (Expr, Etype (Subp));
1361 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
1364 Error_Msg_Name_1 := Attr;
1365 Error_Msg_N ("incorrect expression for% attribute", Expr);
1367 end Analyze_Stream_TSS_Definition;
1369 ----------------------
1370 -- Duplicate_Clause --
1371 ----------------------
1373 function Duplicate_Clause return Boolean is
1377 -- Nothing to do if this attribute definition clause comes from
1378 -- an aspect specification, since we could not be duplicating an
1379 -- explicit clause, and we dealt with the case of duplicated aspects
1380 -- in Analyze_Aspect_Specifications.
1382 if From_Aspect_Specification (N) then
1386 -- Otherwise current clause may duplicate previous clause or a
1387 -- previously given aspect specification for the same aspect.
1389 A := Get_Rep_Item_For_Entity (U_Ent, Chars (N));
1392 if Entity (A) = U_Ent then
1393 Error_Msg_Name_1 := Chars (N);
1394 Error_Msg_Sloc := Sloc (A);
1395 Error_Msg_NE ("aspect% for & previously given#", N, U_Ent);
1401 end Duplicate_Clause;
1403 -- Start of processing for Analyze_Attribute_Definition_Clause
1406 -- Process Ignore_Rep_Clauses option
1408 if Ignore_Rep_Clauses then
1411 -- The following should be ignored. They do not affect legality
1412 -- and may be target dependent. The basic idea of -gnatI is to
1413 -- ignore any rep clauses that may be target dependent but do not
1414 -- affect legality (except possibly to be rejected because they
1415 -- are incompatible with the compilation target).
1417 when Attribute_Alignment |
1418 Attribute_Bit_Order |
1419 Attribute_Component_Size |
1420 Attribute_Machine_Radix |
1421 Attribute_Object_Size |
1424 Attribute_Stream_Size |
1425 Attribute_Value_Size =>
1427 Rewrite (N, Make_Null_Statement (Sloc (N)));
1430 -- The following should not be ignored, because in the first place
1431 -- they are reasonably portable, and should not cause problems in
1432 -- compiling code from another target, and also they do affect
1433 -- legality, e.g. failing to provide a stream attribute for a
1434 -- type may make a program illegal.
1436 when Attribute_External_Tag |
1440 Attribute_Storage_Pool |
1441 Attribute_Storage_Size |
1445 -- Other cases are errors ("attribute& cannot be set with
1446 -- definition clause"), which will be caught below.
1454 Ent := Entity (Nam);
1456 if Rep_Item_Too_Early (Ent, N) then
1460 -- Rep clause applies to full view of incomplete type or private type if
1461 -- we have one (if not, this is a premature use of the type). However,
1462 -- certain semantic checks need to be done on the specified entity (i.e.
1463 -- the private view), so we save it in Ent.
1465 if Is_Private_Type (Ent)
1466 and then Is_Derived_Type (Ent)
1467 and then not Is_Tagged_Type (Ent)
1468 and then No (Full_View (Ent))
1470 -- If this is a private type whose completion is a derivation from
1471 -- another private type, there is no full view, and the attribute
1472 -- belongs to the type itself, not its underlying parent.
1476 elsif Ekind (Ent) = E_Incomplete_Type then
1478 -- The attribute applies to the full view, set the entity of the
1479 -- attribute definition accordingly.
1481 Ent := Underlying_Type (Ent);
1483 Set_Entity (Nam, Ent);
1486 U_Ent := Underlying_Type (Ent);
1489 -- Complete other routine error checks
1491 if Etype (Nam) = Any_Type then
1494 elsif Scope (Ent) /= Current_Scope then
1495 Error_Msg_N ("entity must be declared in this scope", Nam);
1498 elsif No (U_Ent) then
1501 elsif Is_Type (U_Ent)
1502 and then not Is_First_Subtype (U_Ent)
1503 and then Id /= Attribute_Object_Size
1504 and then Id /= Attribute_Value_Size
1505 and then not From_At_Mod (N)
1507 Error_Msg_N ("cannot specify attribute for subtype", Nam);
1511 Set_Entity (N, U_Ent);
1513 -- Switch on particular attribute
1521 -- Address attribute definition clause
1523 when Attribute_Address => Address : begin
1525 -- A little error check, catch for X'Address use X'Address;
1527 if Nkind (Nam) = N_Identifier
1528 and then Nkind (Expr) = N_Attribute_Reference
1529 and then Attribute_Name (Expr) = Name_Address
1530 and then Nkind (Prefix (Expr)) = N_Identifier
1531 and then Chars (Nam) = Chars (Prefix (Expr))
1534 ("address for & is self-referencing", Prefix (Expr), Ent);
1538 -- Not that special case, carry on with analysis of expression
1540 Analyze_And_Resolve (Expr, RTE (RE_Address));
1542 -- Even when ignoring rep clauses we need to indicate that the
1543 -- entity has an address clause and thus it is legal to declare
1546 if Ignore_Rep_Clauses then
1547 if Ekind_In (U_Ent, E_Variable, E_Constant) then
1548 Record_Rep_Item (U_Ent, N);
1554 if Duplicate_Clause then
1557 -- Case of address clause for subprogram
1559 elsif Is_Subprogram (U_Ent) then
1560 if Has_Homonym (U_Ent) then
1562 ("address clause cannot be given " &
1563 "for overloaded subprogram",
1568 -- For subprograms, all address clauses are permitted, and we
1569 -- mark the subprogram as having a deferred freeze so that Gigi
1570 -- will not elaborate it too soon.
1572 -- Above needs more comments, what is too soon about???
1574 Set_Has_Delayed_Freeze (U_Ent);
1576 -- Case of address clause for entry
1578 elsif Ekind (U_Ent) = E_Entry then
1579 if Nkind (Parent (N)) = N_Task_Body then
1581 ("entry address must be specified in task spec", Nam);
1585 -- For entries, we require a constant address
1587 Check_Constant_Address_Clause (Expr, U_Ent);
1589 -- Special checks for task types
1591 if Is_Task_Type (Scope (U_Ent))
1592 and then Comes_From_Source (Scope (U_Ent))
1595 ("?entry address declared for entry in task type", N);
1597 ("\?only one task can be declared of this type", N);
1600 -- Entry address clauses are obsolescent
1602 Check_Restriction (No_Obsolescent_Features, N);
1604 if Warn_On_Obsolescent_Feature then
1606 ("attaching interrupt to task entry is an " &
1607 "obsolescent feature (RM J.7.1)?", N);
1609 ("\use interrupt procedure instead?", N);
1612 -- Case of an address clause for a controlled object which we
1613 -- consider to be erroneous.
1615 elsif Is_Controlled (Etype (U_Ent))
1616 or else Has_Controlled_Component (Etype (U_Ent))
1619 ("?controlled object& must not be overlaid", Nam, U_Ent);
1621 ("\?Program_Error will be raised at run time", Nam);
1622 Insert_Action (Declaration_Node (U_Ent),
1623 Make_Raise_Program_Error (Loc,
1624 Reason => PE_Overlaid_Controlled_Object));
1627 -- Case of address clause for a (non-controlled) object
1630 Ekind (U_Ent) = E_Variable
1632 Ekind (U_Ent) = E_Constant
1635 Expr : constant Node_Id := Expression (N);
1640 -- Exported variables cannot have an address clause, because
1641 -- this cancels the effect of the pragma Export.
1643 if Is_Exported (U_Ent) then
1645 ("cannot export object with address clause", Nam);
1649 Find_Overlaid_Entity (N, O_Ent, Off);
1651 -- Overlaying controlled objects is erroneous
1654 and then (Has_Controlled_Component (Etype (O_Ent))
1655 or else Is_Controlled (Etype (O_Ent)))
1658 ("?cannot overlay with controlled object", Expr);
1660 ("\?Program_Error will be raised at run time", Expr);
1661 Insert_Action (Declaration_Node (U_Ent),
1662 Make_Raise_Program_Error (Loc,
1663 Reason => PE_Overlaid_Controlled_Object));
1666 elsif Present (O_Ent)
1667 and then Ekind (U_Ent) = E_Constant
1668 and then not Is_Constant_Object (O_Ent)
1670 Error_Msg_N ("constant overlays a variable?", Expr);
1672 elsif Present (Renamed_Object (U_Ent)) then
1674 ("address clause not allowed"
1675 & " for a renaming declaration (RM 13.1(6))", Nam);
1678 -- Imported variables can have an address clause, but then
1679 -- the import is pretty meaningless except to suppress
1680 -- initializations, so we do not need such variables to
1681 -- be statically allocated (and in fact it causes trouble
1682 -- if the address clause is a local value).
1684 elsif Is_Imported (U_Ent) then
1685 Set_Is_Statically_Allocated (U_Ent, False);
1688 -- We mark a possible modification of a variable with an
1689 -- address clause, since it is likely aliasing is occurring.
1691 Note_Possible_Modification (Nam, Sure => False);
1693 -- Here we are checking for explicit overlap of one variable
1694 -- by another, and if we find this then mark the overlapped
1695 -- variable as also being volatile to prevent unwanted
1696 -- optimizations. This is a significant pessimization so
1697 -- avoid it when there is an offset, i.e. when the object
1698 -- is composite; they cannot be optimized easily anyway.
1701 and then Is_Object (O_Ent)
1704 Set_Treat_As_Volatile (O_Ent);
1707 -- Legality checks on the address clause for initialized
1708 -- objects is deferred until the freeze point, because
1709 -- a subsequent pragma might indicate that the object is
1710 -- imported and thus not initialized.
1712 Set_Has_Delayed_Freeze (U_Ent);
1714 -- If an initialization call has been generated for this
1715 -- object, it needs to be deferred to after the freeze node
1716 -- we have just now added, otherwise GIGI will see a
1717 -- reference to the variable (as actual to the IP call)
1718 -- before its definition.
1721 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1723 if Present (Init_Call) then
1725 Append_Freeze_Action (U_Ent, Init_Call);
1729 if Is_Exported (U_Ent) then
1731 ("& cannot be exported if an address clause is given",
1734 ("\define and export a variable " &
1735 "that holds its address instead",
1739 -- Entity has delayed freeze, so we will generate an
1740 -- alignment check at the freeze point unless suppressed.
1742 if not Range_Checks_Suppressed (U_Ent)
1743 and then not Alignment_Checks_Suppressed (U_Ent)
1745 Set_Check_Address_Alignment (N);
1748 -- Kill the size check code, since we are not allocating
1749 -- the variable, it is somewhere else.
1751 Kill_Size_Check_Code (U_Ent);
1753 -- If the address clause is of the form:
1755 -- for Y'Address use X'Address
1759 -- Const : constant Address := X'Address;
1761 -- for Y'Address use Const;
1763 -- then we make an entry in the table for checking the size
1764 -- and alignment of the overlaying variable. We defer this
1765 -- check till after code generation to take full advantage
1766 -- of the annotation done by the back end. This entry is
1767 -- only made if the address clause comes from source.
1768 -- If the entity has a generic type, the check will be
1769 -- performed in the instance if the actual type justifies
1770 -- it, and we do not insert the clause in the table to
1771 -- prevent spurious warnings.
1773 if Address_Clause_Overlay_Warnings
1774 and then Comes_From_Source (N)
1775 and then Present (O_Ent)
1776 and then Is_Object (O_Ent)
1778 if not Is_Generic_Type (Etype (U_Ent)) then
1779 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1782 -- If variable overlays a constant view, and we are
1783 -- warning on overlays, then mark the variable as
1784 -- overlaying a constant (we will give warnings later
1785 -- if this variable is assigned).
1787 if Is_Constant_Object (O_Ent)
1788 and then Ekind (U_Ent) = E_Variable
1790 Set_Overlays_Constant (U_Ent);
1795 -- Not a valid entity for an address clause
1798 Error_Msg_N ("address cannot be given for &", Nam);
1806 -- Alignment attribute definition clause
1808 when Attribute_Alignment => Alignment : declare
1809 Align : constant Uint := Get_Alignment_Value (Expr);
1814 if not Is_Type (U_Ent)
1815 and then Ekind (U_Ent) /= E_Variable
1816 and then Ekind (U_Ent) /= E_Constant
1818 Error_Msg_N ("alignment cannot be given for &", Nam);
1820 elsif Duplicate_Clause then
1823 elsif Align /= No_Uint then
1824 Set_Has_Alignment_Clause (U_Ent);
1825 Set_Alignment (U_Ent, Align);
1827 -- For an array type, U_Ent is the first subtype. In that case,
1828 -- also set the alignment of the anonymous base type so that
1829 -- other subtypes (such as the itypes for aggregates of the
1830 -- type) also receive the expected alignment.
1832 if Is_Array_Type (U_Ent) then
1833 Set_Alignment (Base_Type (U_Ent), Align);
1842 -- Bit_Order attribute definition clause
1844 when Attribute_Bit_Order => Bit_Order : declare
1846 if not Is_Record_Type (U_Ent) then
1848 ("Bit_Order can only be defined for record type", Nam);
1850 elsif Duplicate_Clause then
1854 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1856 if Etype (Expr) = Any_Type then
1859 elsif not Is_Static_Expression (Expr) then
1860 Flag_Non_Static_Expr
1861 ("Bit_Order requires static expression!", Expr);
1864 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1865 Set_Reverse_Bit_Order (U_Ent, True);
1871 --------------------
1872 -- Component_Size --
1873 --------------------
1875 -- Component_Size attribute definition clause
1877 when Attribute_Component_Size => Component_Size_Case : declare
1878 Csize : constant Uint := Static_Integer (Expr);
1882 New_Ctyp : Entity_Id;
1886 if not Is_Array_Type (U_Ent) then
1887 Error_Msg_N ("component size requires array type", Nam);
1891 Btype := Base_Type (U_Ent);
1892 Ctyp := Component_Type (Btype);
1894 if Duplicate_Clause then
1897 elsif Rep_Item_Too_Early (Btype, N) then
1900 elsif Csize /= No_Uint then
1901 Check_Size (Expr, Ctyp, Csize, Biased);
1903 -- For the biased case, build a declaration for a subtype that
1904 -- will be used to represent the biased subtype that reflects
1905 -- the biased representation of components. We need the subtype
1906 -- to get proper conversions on referencing elements of the
1907 -- array. Note: component size clauses are ignored in VM mode.
1909 if VM_Target = No_VM then
1912 Make_Defining_Identifier (Loc,
1914 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1917 Make_Subtype_Declaration (Loc,
1918 Defining_Identifier => New_Ctyp,
1919 Subtype_Indication =>
1920 New_Occurrence_Of (Component_Type (Btype), Loc));
1922 Set_Parent (Decl, N);
1923 Analyze (Decl, Suppress => All_Checks);
1925 Set_Has_Delayed_Freeze (New_Ctyp, False);
1926 Set_Esize (New_Ctyp, Csize);
1927 Set_RM_Size (New_Ctyp, Csize);
1928 Init_Alignment (New_Ctyp);
1929 Set_Is_Itype (New_Ctyp, True);
1930 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1932 Set_Component_Type (Btype, New_Ctyp);
1933 Set_Biased (New_Ctyp, N, "component size clause");
1936 Set_Component_Size (Btype, Csize);
1938 -- For VM case, we ignore component size clauses
1941 -- Give a warning unless we are in GNAT mode, in which case
1942 -- the warning is suppressed since it is not useful.
1944 if not GNAT_Mode then
1946 ("?component size ignored in this configuration", N);
1950 -- Deal with warning on overridden size
1952 if Warn_On_Overridden_Size
1953 and then Has_Size_Clause (Ctyp)
1954 and then RM_Size (Ctyp) /= Csize
1957 ("?component size overrides size clause for&",
1961 Set_Has_Component_Size_Clause (Btype, True);
1962 Set_Has_Non_Standard_Rep (Btype, True);
1964 end Component_Size_Case;
1970 when Attribute_External_Tag => External_Tag :
1972 if not Is_Tagged_Type (U_Ent) then
1973 Error_Msg_N ("should be a tagged type", Nam);
1976 if Duplicate_Clause then
1980 Analyze_And_Resolve (Expr, Standard_String);
1982 if not Is_Static_Expression (Expr) then
1983 Flag_Non_Static_Expr
1984 ("static string required for tag name!", Nam);
1987 if VM_Target = No_VM then
1988 Set_Has_External_Tag_Rep_Clause (U_Ent);
1990 Error_Msg_Name_1 := Attr;
1992 ("% attribute unsupported in this configuration", Nam);
1995 if not Is_Library_Level_Entity (U_Ent) then
1997 ("?non-unique external tag supplied for &", N, U_Ent);
1999 ("?\same external tag applies to all subprogram calls", N);
2001 ("?\corresponding internal tag cannot be obtained", N);
2010 when Attribute_Input =>
2011 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
2012 Set_Has_Specified_Stream_Input (Ent);
2018 -- Machine radix attribute definition clause
2020 when Attribute_Machine_Radix => Machine_Radix : declare
2021 Radix : constant Uint := Static_Integer (Expr);
2024 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
2025 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
2027 elsif Duplicate_Clause then
2030 elsif Radix /= No_Uint then
2031 Set_Has_Machine_Radix_Clause (U_Ent);
2032 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
2036 elsif Radix = 10 then
2037 Set_Machine_Radix_10 (U_Ent);
2039 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
2048 -- Object_Size attribute definition clause
2050 when Attribute_Object_Size => Object_Size : declare
2051 Size : constant Uint := Static_Integer (Expr);
2054 pragma Warnings (Off, Biased);
2057 if not Is_Type (U_Ent) then
2058 Error_Msg_N ("Object_Size cannot be given for &", Nam);
2060 elsif Duplicate_Clause then
2064 Check_Size (Expr, U_Ent, Size, Biased);
2072 UI_Mod (Size, 64) /= 0
2075 ("Object_Size must be 8, 16, 32, or multiple of 64",
2079 Set_Esize (U_Ent, Size);
2080 Set_Has_Object_Size_Clause (U_Ent);
2081 Alignment_Check_For_Esize_Change (U_Ent);
2089 when Attribute_Output =>
2090 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
2091 Set_Has_Specified_Stream_Output (Ent);
2097 when Attribute_Read =>
2098 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
2099 Set_Has_Specified_Stream_Read (Ent);
2105 -- Size attribute definition clause
2107 when Attribute_Size => Size : declare
2108 Size : constant Uint := Static_Integer (Expr);
2115 if Duplicate_Clause then
2118 elsif not Is_Type (U_Ent)
2119 and then Ekind (U_Ent) /= E_Variable
2120 and then Ekind (U_Ent) /= E_Constant
2122 Error_Msg_N ("size cannot be given for &", Nam);
2124 elsif Is_Array_Type (U_Ent)
2125 and then not Is_Constrained (U_Ent)
2128 ("size cannot be given for unconstrained array", Nam);
2130 elsif Size /= No_Uint then
2132 if VM_Target /= No_VM and then not GNAT_Mode then
2134 -- Size clause is not handled properly on VM targets.
2135 -- Display a warning unless we are in GNAT mode, in which
2136 -- case this is useless.
2139 ("?size clauses are ignored in this configuration", N);
2142 if Is_Type (U_Ent) then
2145 Etyp := Etype (U_Ent);
2148 -- Check size, note that Gigi is in charge of checking that the
2149 -- size of an array or record type is OK. Also we do not check
2150 -- the size in the ordinary fixed-point case, since it is too
2151 -- early to do so (there may be subsequent small clause that
2152 -- affects the size). We can check the size if a small clause
2153 -- has already been given.
2155 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
2156 or else Has_Small_Clause (U_Ent)
2158 Check_Size (Expr, Etyp, Size, Biased);
2159 Set_Biased (U_Ent, N, "size clause", Biased);
2162 -- For types set RM_Size and Esize if possible
2164 if Is_Type (U_Ent) then
2165 Set_RM_Size (U_Ent, Size);
2167 -- For scalar types, increase Object_Size to power of 2, but
2168 -- not less than a storage unit in any case (i.e., normally
2169 -- this means it will be byte addressable).
2171 if Is_Scalar_Type (U_Ent) then
2172 if Size <= System_Storage_Unit then
2173 Init_Esize (U_Ent, System_Storage_Unit);
2174 elsif Size <= 16 then
2175 Init_Esize (U_Ent, 16);
2176 elsif Size <= 32 then
2177 Init_Esize (U_Ent, 32);
2179 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
2182 -- For all other types, object size = value size. The
2183 -- backend will adjust as needed.
2186 Set_Esize (U_Ent, Size);
2189 Alignment_Check_For_Esize_Change (U_Ent);
2191 -- For objects, set Esize only
2194 if Is_Elementary_Type (Etyp) then
2195 if Size /= System_Storage_Unit
2197 Size /= System_Storage_Unit * 2
2199 Size /= System_Storage_Unit * 4
2201 Size /= System_Storage_Unit * 8
2203 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
2204 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
2206 ("size for primitive object must be a power of 2"
2207 & " in the range ^-^", N);
2211 Set_Esize (U_Ent, Size);
2214 Set_Has_Size_Clause (U_Ent);
2222 -- Small attribute definition clause
2224 when Attribute_Small => Small : declare
2225 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
2229 Analyze_And_Resolve (Expr, Any_Real);
2231 if Etype (Expr) = Any_Type then
2234 elsif not Is_Static_Expression (Expr) then
2235 Flag_Non_Static_Expr
2236 ("small requires static expression!", Expr);
2240 Small := Expr_Value_R (Expr);
2242 if Small <= Ureal_0 then
2243 Error_Msg_N ("small value must be greater than zero", Expr);
2249 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
2251 ("small requires an ordinary fixed point type", Nam);
2253 elsif Has_Small_Clause (U_Ent) then
2254 Error_Msg_N ("small already given for &", Nam);
2256 elsif Small > Delta_Value (U_Ent) then
2258 ("small value must not be greater then delta value", Nam);
2261 Set_Small_Value (U_Ent, Small);
2262 Set_Small_Value (Implicit_Base, Small);
2263 Set_Has_Small_Clause (U_Ent);
2264 Set_Has_Small_Clause (Implicit_Base);
2265 Set_Has_Non_Standard_Rep (Implicit_Base);
2273 -- Storage_Pool attribute definition clause
2275 when Attribute_Storage_Pool => Storage_Pool : declare
2280 if Ekind (U_Ent) = E_Access_Subprogram_Type then
2282 ("storage pool cannot be given for access-to-subprogram type",
2287 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
2290 ("storage pool can only be given for access types", Nam);
2293 elsif Is_Derived_Type (U_Ent) then
2295 ("storage pool cannot be given for a derived access type",
2298 elsif Duplicate_Clause then
2301 elsif Present (Associated_Storage_Pool (U_Ent)) then
2302 Error_Msg_N ("storage pool already given for &", Nam);
2307 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
2309 if not Denotes_Variable (Expr) then
2310 Error_Msg_N ("storage pool must be a variable", Expr);
2314 if Nkind (Expr) = N_Type_Conversion then
2315 T := Etype (Expression (Expr));
2320 -- The Stack_Bounded_Pool is used internally for implementing
2321 -- access types with a Storage_Size. Since it only work
2322 -- properly when used on one specific type, we need to check
2323 -- that it is not hijacked improperly:
2324 -- type T is access Integer;
2325 -- for T'Storage_Size use n;
2326 -- type Q is access Float;
2327 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
2329 if RTE_Available (RE_Stack_Bounded_Pool)
2330 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
2332 Error_Msg_N ("non-shareable internal Pool", Expr);
2336 -- If the argument is a name that is not an entity name, then
2337 -- we construct a renaming operation to define an entity of
2338 -- type storage pool.
2340 if not Is_Entity_Name (Expr)
2341 and then Is_Object_Reference (Expr)
2343 Pool := Make_Temporary (Loc, 'P', Expr);
2346 Rnode : constant Node_Id :=
2347 Make_Object_Renaming_Declaration (Loc,
2348 Defining_Identifier => Pool,
2350 New_Occurrence_Of (Etype (Expr), Loc),
2354 Insert_Before (N, Rnode);
2356 Set_Associated_Storage_Pool (U_Ent, Pool);
2359 elsif Is_Entity_Name (Expr) then
2360 Pool := Entity (Expr);
2362 -- If pool is a renamed object, get original one. This can
2363 -- happen with an explicit renaming, and within instances.
2365 while Present (Renamed_Object (Pool))
2366 and then Is_Entity_Name (Renamed_Object (Pool))
2368 Pool := Entity (Renamed_Object (Pool));
2371 if Present (Renamed_Object (Pool))
2372 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
2373 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
2375 Pool := Entity (Expression (Renamed_Object (Pool)));
2378 Set_Associated_Storage_Pool (U_Ent, Pool);
2380 elsif Nkind (Expr) = N_Type_Conversion
2381 and then Is_Entity_Name (Expression (Expr))
2382 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
2384 Pool := Entity (Expression (Expr));
2385 Set_Associated_Storage_Pool (U_Ent, Pool);
2388 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
2397 -- Storage_Size attribute definition clause
2399 when Attribute_Storage_Size => Storage_Size : declare
2400 Btype : constant Entity_Id := Base_Type (U_Ent);
2404 if Is_Task_Type (U_Ent) then
2405 Check_Restriction (No_Obsolescent_Features, N);
2407 if Warn_On_Obsolescent_Feature then
2409 ("storage size clause for task is an " &
2410 "obsolescent feature (RM J.9)?", N);
2411 Error_Msg_N ("\use Storage_Size pragma instead?", N);
2417 if not Is_Access_Type (U_Ent)
2418 and then Ekind (U_Ent) /= E_Task_Type
2420 Error_Msg_N ("storage size cannot be given for &", Nam);
2422 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
2424 ("storage size cannot be given for a derived access type",
2427 elsif Duplicate_Clause then
2431 Analyze_And_Resolve (Expr, Any_Integer);
2433 if Is_Access_Type (U_Ent) then
2434 if Present (Associated_Storage_Pool (U_Ent)) then
2435 Error_Msg_N ("storage pool already given for &", Nam);
2439 if Is_OK_Static_Expression (Expr)
2440 and then Expr_Value (Expr) = 0
2442 Set_No_Pool_Assigned (Btype);
2445 else -- Is_Task_Type (U_Ent)
2446 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
2448 if Present (Sprag) then
2449 Error_Msg_Sloc := Sloc (Sprag);
2451 ("Storage_Size already specified#", Nam);
2456 Set_Has_Storage_Size_Clause (Btype);
2464 when Attribute_Stream_Size => Stream_Size : declare
2465 Size : constant Uint := Static_Integer (Expr);
2468 if Ada_Version <= Ada_95 then
2469 Check_Restriction (No_Implementation_Attributes, N);
2472 if Duplicate_Clause then
2475 elsif Is_Elementary_Type (U_Ent) then
2476 if Size /= System_Storage_Unit
2478 Size /= System_Storage_Unit * 2
2480 Size /= System_Storage_Unit * 4
2482 Size /= System_Storage_Unit * 8
2484 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
2486 ("stream size for elementary type must be a"
2487 & " power of 2 and at least ^", N);
2489 elsif RM_Size (U_Ent) > Size then
2490 Error_Msg_Uint_1 := RM_Size (U_Ent);
2492 ("stream size for elementary type must be a"
2493 & " power of 2 and at least ^", N);
2496 Set_Has_Stream_Size_Clause (U_Ent);
2499 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
2507 -- Value_Size attribute definition clause
2509 when Attribute_Value_Size => Value_Size : declare
2510 Size : constant Uint := Static_Integer (Expr);
2514 if not Is_Type (U_Ent) then
2515 Error_Msg_N ("Value_Size cannot be given for &", Nam);
2517 elsif Duplicate_Clause then
2520 elsif Is_Array_Type (U_Ent)
2521 and then not Is_Constrained (U_Ent)
2524 ("Value_Size cannot be given for unconstrained array", Nam);
2527 if Is_Elementary_Type (U_Ent) then
2528 Check_Size (Expr, U_Ent, Size, Biased);
2529 Set_Biased (U_Ent, N, "value size clause", Biased);
2532 Set_RM_Size (U_Ent, Size);
2540 when Attribute_Write =>
2541 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
2542 Set_Has_Specified_Stream_Write (Ent);
2544 -- All other attributes cannot be set
2548 ("attribute& cannot be set with definition clause", N);
2551 -- The test for the type being frozen must be performed after
2552 -- any expression the clause has been analyzed since the expression
2553 -- itself might cause freezing that makes the clause illegal.
2555 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
2558 end Analyze_Attribute_Definition_Clause;
2560 ----------------------------
2561 -- Analyze_Code_Statement --
2562 ----------------------------
2564 procedure Analyze_Code_Statement (N : Node_Id) is
2565 HSS : constant Node_Id := Parent (N);
2566 SBody : constant Node_Id := Parent (HSS);
2567 Subp : constant Entity_Id := Current_Scope;
2574 -- Analyze and check we get right type, note that this implements the
2575 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
2576 -- is the only way that Asm_Insn could possibly be visible.
2578 Analyze_And_Resolve (Expression (N));
2580 if Etype (Expression (N)) = Any_Type then
2582 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
2583 Error_Msg_N ("incorrect type for code statement", N);
2587 Check_Code_Statement (N);
2589 -- Make sure we appear in the handled statement sequence of a
2590 -- subprogram (RM 13.8(3)).
2592 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2593 or else Nkind (SBody) /= N_Subprogram_Body
2596 ("code statement can only appear in body of subprogram", N);
2600 -- Do remaining checks (RM 13.8(3)) if not already done
2602 if not Is_Machine_Code_Subprogram (Subp) then
2603 Set_Is_Machine_Code_Subprogram (Subp);
2605 -- No exception handlers allowed
2607 if Present (Exception_Handlers (HSS)) then
2609 ("exception handlers not permitted in machine code subprogram",
2610 First (Exception_Handlers (HSS)));
2613 -- No declarations other than use clauses and pragmas (we allow
2614 -- certain internally generated declarations as well).
2616 Decl := First (Declarations (SBody));
2617 while Present (Decl) loop
2618 DeclO := Original_Node (Decl);
2619 if Comes_From_Source (DeclO)
2620 and not Nkind_In (DeclO, N_Pragma,
2621 N_Use_Package_Clause,
2623 N_Implicit_Label_Declaration)
2626 ("this declaration not allowed in machine code subprogram",
2633 -- No statements other than code statements, pragmas, and labels.
2634 -- Again we allow certain internally generated statements.
2636 Stmt := First (Statements (HSS));
2637 while Present (Stmt) loop
2638 StmtO := Original_Node (Stmt);
2639 if Comes_From_Source (StmtO)
2640 and then not Nkind_In (StmtO, N_Pragma,
2645 ("this statement is not allowed in machine code subprogram",
2652 end Analyze_Code_Statement;
2654 -----------------------------------------------
2655 -- Analyze_Enumeration_Representation_Clause --
2656 -----------------------------------------------
2658 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2659 Ident : constant Node_Id := Identifier (N);
2660 Aggr : constant Node_Id := Array_Aggregate (N);
2661 Enumtype : Entity_Id;
2667 Err : Boolean := False;
2669 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2670 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2671 -- Allowed range of universal integer (= allowed range of enum lit vals)
2675 -- Minimum and maximum values of entries
2678 -- Pointer to node for literal providing max value
2681 if Ignore_Rep_Clauses then
2685 -- First some basic error checks
2688 Enumtype := Entity (Ident);
2690 if Enumtype = Any_Type
2691 or else Rep_Item_Too_Early (Enumtype, N)
2695 Enumtype := Underlying_Type (Enumtype);
2698 if not Is_Enumeration_Type (Enumtype) then
2700 ("enumeration type required, found}",
2701 Ident, First_Subtype (Enumtype));
2705 -- Ignore rep clause on generic actual type. This will already have
2706 -- been flagged on the template as an error, and this is the safest
2707 -- way to ensure we don't get a junk cascaded message in the instance.
2709 if Is_Generic_Actual_Type (Enumtype) then
2712 -- Type must be in current scope
2714 elsif Scope (Enumtype) /= Current_Scope then
2715 Error_Msg_N ("type must be declared in this scope", Ident);
2718 -- Type must be a first subtype
2720 elsif not Is_First_Subtype (Enumtype) then
2721 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2724 -- Ignore duplicate rep clause
2726 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2727 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2730 -- Don't allow rep clause for standard [wide_[wide_]]character
2732 elsif Is_Standard_Character_Type (Enumtype) then
2733 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2736 -- Check that the expression is a proper aggregate (no parentheses)
2738 elsif Paren_Count (Aggr) /= 0 then
2740 ("extra parentheses surrounding aggregate not allowed",
2744 -- All tests passed, so set rep clause in place
2747 Set_Has_Enumeration_Rep_Clause (Enumtype);
2748 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2751 -- Now we process the aggregate. Note that we don't use the normal
2752 -- aggregate code for this purpose, because we don't want any of the
2753 -- normal expansion activities, and a number of special semantic
2754 -- rules apply (including the component type being any integer type)
2756 Elit := First_Literal (Enumtype);
2758 -- First the positional entries if any
2760 if Present (Expressions (Aggr)) then
2761 Expr := First (Expressions (Aggr));
2762 while Present (Expr) loop
2764 Error_Msg_N ("too many entries in aggregate", Expr);
2768 Val := Static_Integer (Expr);
2770 -- Err signals that we found some incorrect entries processing
2771 -- the list. The final checks for completeness and ordering are
2772 -- skipped in this case.
2774 if Val = No_Uint then
2776 elsif Val < Lo or else Hi < Val then
2777 Error_Msg_N ("value outside permitted range", Expr);
2781 Set_Enumeration_Rep (Elit, Val);
2782 Set_Enumeration_Rep_Expr (Elit, Expr);
2788 -- Now process the named entries if present
2790 if Present (Component_Associations (Aggr)) then
2791 Assoc := First (Component_Associations (Aggr));
2792 while Present (Assoc) loop
2793 Choice := First (Choices (Assoc));
2795 if Present (Next (Choice)) then
2797 ("multiple choice not allowed here", Next (Choice));
2801 if Nkind (Choice) = N_Others_Choice then
2802 Error_Msg_N ("others choice not allowed here", Choice);
2805 elsif Nkind (Choice) = N_Range then
2806 -- ??? should allow zero/one element range here
2807 Error_Msg_N ("range not allowed here", Choice);
2811 Analyze_And_Resolve (Choice, Enumtype);
2813 if Is_Entity_Name (Choice)
2814 and then Is_Type (Entity (Choice))
2816 Error_Msg_N ("subtype name not allowed here", Choice);
2818 -- ??? should allow static subtype with zero/one entry
2820 elsif Etype (Choice) = Base_Type (Enumtype) then
2821 if not Is_Static_Expression (Choice) then
2822 Flag_Non_Static_Expr
2823 ("non-static expression used for choice!", Choice);
2827 Elit := Expr_Value_E (Choice);
2829 if Present (Enumeration_Rep_Expr (Elit)) then
2830 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2832 ("representation for& previously given#",
2837 Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
2839 Expr := Expression (Assoc);
2840 Val := Static_Integer (Expr);
2842 if Val = No_Uint then
2845 elsif Val < Lo or else Hi < Val then
2846 Error_Msg_N ("value outside permitted range", Expr);
2850 Set_Enumeration_Rep (Elit, Val);
2859 -- Aggregate is fully processed. Now we check that a full set of
2860 -- representations was given, and that they are in range and in order.
2861 -- These checks are only done if no other errors occurred.
2867 Elit := First_Literal (Enumtype);
2868 while Present (Elit) loop
2869 if No (Enumeration_Rep_Expr (Elit)) then
2870 Error_Msg_NE ("missing representation for&!", N, Elit);
2873 Val := Enumeration_Rep (Elit);
2875 if Min = No_Uint then
2879 if Val /= No_Uint then
2880 if Max /= No_Uint and then Val <= Max then
2882 ("enumeration value for& not ordered!",
2883 Enumeration_Rep_Expr (Elit), Elit);
2886 Max_Node := Enumeration_Rep_Expr (Elit);
2890 -- If there is at least one literal whose representation is not
2891 -- equal to the Pos value, then note that this enumeration type
2892 -- has a non-standard representation.
2894 if Val /= Enumeration_Pos (Elit) then
2895 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2902 -- Now set proper size information
2905 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2908 if Has_Size_Clause (Enumtype) then
2910 -- All OK, if size is OK now
2912 if RM_Size (Enumtype) >= Minsize then
2916 -- Try if we can get by with biasing
2919 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2921 -- Error message if even biasing does not work
2923 if RM_Size (Enumtype) < Minsize then
2924 Error_Msg_Uint_1 := RM_Size (Enumtype);
2925 Error_Msg_Uint_2 := Max;
2927 ("previously given size (^) is too small "
2928 & "for this value (^)", Max_Node);
2930 -- If biasing worked, indicate that we now have biased rep
2934 (Enumtype, Size_Clause (Enumtype), "size clause");
2939 Set_RM_Size (Enumtype, Minsize);
2940 Set_Enum_Esize (Enumtype);
2943 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2944 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2945 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2949 -- We repeat the too late test in case it froze itself!
2951 if Rep_Item_Too_Late (Enumtype, N) then
2954 end Analyze_Enumeration_Representation_Clause;
2956 ----------------------------
2957 -- Analyze_Free_Statement --
2958 ----------------------------
2960 procedure Analyze_Free_Statement (N : Node_Id) is
2962 Analyze (Expression (N));
2963 end Analyze_Free_Statement;
2965 ---------------------------
2966 -- Analyze_Freeze_Entity --
2967 ---------------------------
2969 procedure Analyze_Freeze_Entity (N : Node_Id) is
2970 E : constant Entity_Id := Entity (N);
2973 -- Remember that we are processing a freezing entity. Required to
2974 -- ensure correct decoration of internal entities associated with
2975 -- interfaces (see New_Overloaded_Entity).
2977 Inside_Freezing_Actions := Inside_Freezing_Actions + 1;
2979 -- For tagged types covering interfaces add internal entities that link
2980 -- the primitives of the interfaces with the primitives that cover them.
2981 -- Note: These entities were originally generated only when generating
2982 -- code because their main purpose was to provide support to initialize
2983 -- the secondary dispatch tables. They are now generated also when
2984 -- compiling with no code generation to provide ASIS the relationship
2985 -- between interface primitives and tagged type primitives. They are
2986 -- also used to locate primitives covering interfaces when processing
2987 -- generics (see Derive_Subprograms).
2989 if Ada_Version >= Ada_2005
2990 and then Ekind (E) = E_Record_Type
2991 and then Is_Tagged_Type (E)
2992 and then not Is_Interface (E)
2993 and then Has_Interfaces (E)
2995 -- This would be a good common place to call the routine that checks
2996 -- overriding of interface primitives (and thus factorize calls to
2997 -- Check_Abstract_Overriding located at different contexts in the
2998 -- compiler). However, this is not possible because it causes
2999 -- spurious errors in case of late overriding.
3001 Add_Internal_Interface_Entities (E);
3006 if Ekind (E) = E_Record_Type
3007 and then Is_CPP_Class (E)
3008 and then Is_Tagged_Type (E)
3009 and then Tagged_Type_Expansion
3010 and then Expander_Active
3012 if CPP_Num_Prims (E) = 0 then
3014 -- If the CPP type has user defined components then it must import
3015 -- primitives from C++. This is required because if the C++ class
3016 -- has no primitives then the C++ compiler does not added the _tag
3017 -- component to the type.
3019 pragma Assert (Chars (First_Entity (E)) = Name_uTag);
3021 if First_Entity (E) /= Last_Entity (E) then
3023 ("?'C'P'P type must import at least one primitive from C++",
3028 -- Check that all its primitives are abstract or imported from C++.
3029 -- Check also availability of the C++ constructor.
3032 Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
3034 Error_Reported : Boolean := False;
3038 Elmt := First_Elmt (Primitive_Operations (E));
3039 while Present (Elmt) loop
3040 Prim := Node (Elmt);
3042 if Comes_From_Source (Prim) then
3043 if Is_Abstract_Subprogram (Prim) then
3046 elsif not Is_Imported (Prim)
3047 or else Convention (Prim) /= Convention_CPP
3050 ("?primitives of 'C'P'P types must be imported from C++"
3051 & " or abstract", Prim);
3053 elsif not Has_Constructors
3054 and then not Error_Reported
3056 Error_Msg_Name_1 := Chars (E);
3058 ("?'C'P'P constructor required for type %", Prim);
3059 Error_Reported := True;
3068 Inside_Freezing_Actions := Inside_Freezing_Actions - 1;
3070 -- If we have a type with predicates, build predicate function
3072 if Is_Type (E) and then Has_Predicates (E) then
3078 Build_Predicate_Function (E, FDecl, FBody);
3080 if Present (FDecl) then
3081 Insert_After (N, FBody);
3082 Insert_After (N, FDecl);
3086 end Analyze_Freeze_Entity;
3088 ------------------------------------------
3089 -- Analyze_Record_Representation_Clause --
3090 ------------------------------------------
3092 -- Note: we check as much as we can here, but we can't do any checks
3093 -- based on the position values (e.g. overlap checks) until freeze time
3094 -- because especially in Ada 2005 (machine scalar mode), the processing
3095 -- for non-standard bit order can substantially change the positions.
3096 -- See procedure Check_Record_Representation_Clause (called from Freeze)
3097 -- for the remainder of this processing.
3099 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
3100 Ident : constant Node_Id := Identifier (N);
3105 Hbit : Uint := Uint_0;
3109 Rectype : Entity_Id;
3111 CR_Pragma : Node_Id := Empty;
3112 -- Points to N_Pragma node if Complete_Representation pragma present
3115 if Ignore_Rep_Clauses then
3120 Rectype := Entity (Ident);
3122 if Rectype = Any_Type
3123 or else Rep_Item_Too_Early (Rectype, N)
3127 Rectype := Underlying_Type (Rectype);
3130 -- First some basic error checks
3132 if not Is_Record_Type (Rectype) then
3134 ("record type required, found}", Ident, First_Subtype (Rectype));
3137 elsif Scope (Rectype) /= Current_Scope then
3138 Error_Msg_N ("type must be declared in this scope", N);
3141 elsif not Is_First_Subtype (Rectype) then
3142 Error_Msg_N ("cannot give record rep clause for subtype", N);
3145 elsif Has_Record_Rep_Clause (Rectype) then
3146 Error_Msg_N ("duplicate record rep clause ignored", N);
3149 elsif Rep_Item_Too_Late (Rectype, N) then
3153 if Present (Mod_Clause (N)) then
3155 Loc : constant Source_Ptr := Sloc (N);
3156 M : constant Node_Id := Mod_Clause (N);
3157 P : constant List_Id := Pragmas_Before (M);
3161 pragma Warnings (Off, Mod_Val);
3164 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
3166 if Warn_On_Obsolescent_Feature then
3168 ("mod clause is an obsolescent feature (RM J.8)?", N);
3170 ("\use alignment attribute definition clause instead?", N);
3177 -- In ASIS_Mode mode, expansion is disabled, but we must convert
3178 -- the Mod clause into an alignment clause anyway, so that the
3179 -- back-end can compute and back-annotate properly the size and
3180 -- alignment of types that may include this record.
3182 -- This seems dubious, this destroys the source tree in a manner
3183 -- not detectable by ASIS ???
3185 if Operating_Mode = Check_Semantics
3189 Make_Attribute_Definition_Clause (Loc,
3190 Name => New_Reference_To (Base_Type (Rectype), Loc),
3191 Chars => Name_Alignment,
3192 Expression => Relocate_Node (Expression (M)));
3194 Set_From_At_Mod (AtM_Nod);
3195 Insert_After (N, AtM_Nod);
3196 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
3197 Set_Mod_Clause (N, Empty);
3200 -- Get the alignment value to perform error checking
3202 Mod_Val := Get_Alignment_Value (Expression (M));
3207 -- For untagged types, clear any existing component clauses for the
3208 -- type. If the type is derived, this is what allows us to override
3209 -- a rep clause for the parent. For type extensions, the representation
3210 -- of the inherited components is inherited, so we want to keep previous
3211 -- component clauses for completeness.
3213 if not Is_Tagged_Type (Rectype) then
3214 Comp := First_Component_Or_Discriminant (Rectype);
3215 while Present (Comp) loop
3216 Set_Component_Clause (Comp, Empty);
3217 Next_Component_Or_Discriminant (Comp);
3221 -- All done if no component clauses
3223 CC := First (Component_Clauses (N));
3229 -- A representation like this applies to the base type
3231 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
3232 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
3233 Set_Has_Specified_Layout (Base_Type (Rectype));
3235 -- Process the component clauses
3237 while Present (CC) loop
3241 if Nkind (CC) = N_Pragma then
3244 -- The only pragma of interest is Complete_Representation
3246 if Pragma_Name (CC) = Name_Complete_Representation then
3250 -- Processing for real component clause
3253 Posit := Static_Integer (Position (CC));
3254 Fbit := Static_Integer (First_Bit (CC));
3255 Lbit := Static_Integer (Last_Bit (CC));
3258 and then Fbit /= No_Uint
3259 and then Lbit /= No_Uint
3263 ("position cannot be negative", Position (CC));
3267 ("first bit cannot be negative", First_Bit (CC));
3269 -- The Last_Bit specified in a component clause must not be
3270 -- less than the First_Bit minus one (RM-13.5.1(10)).
3272 elsif Lbit < Fbit - 1 then
3274 ("last bit cannot be less than first bit minus one",
3277 -- Values look OK, so find the corresponding record component
3278 -- Even though the syntax allows an attribute reference for
3279 -- implementation-defined components, GNAT does not allow the
3280 -- tag to get an explicit position.
3282 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
3283 if Attribute_Name (Component_Name (CC)) = Name_Tag then
3284 Error_Msg_N ("position of tag cannot be specified", CC);
3286 Error_Msg_N ("illegal component name", CC);
3290 Comp := First_Entity (Rectype);
3291 while Present (Comp) loop
3292 exit when Chars (Comp) = Chars (Component_Name (CC));
3298 -- Maybe component of base type that is absent from
3299 -- statically constrained first subtype.
3301 Comp := First_Entity (Base_Type (Rectype));
3302 while Present (Comp) loop
3303 exit when Chars (Comp) = Chars (Component_Name (CC));
3310 ("component clause is for non-existent field", CC);
3312 -- Ada 2012 (AI05-0026): Any name that denotes a
3313 -- discriminant of an object of an unchecked union type
3314 -- shall not occur within a record_representation_clause.
3316 -- The general restriction of using record rep clauses on
3317 -- Unchecked_Union types has now been lifted. Since it is
3318 -- possible to introduce a record rep clause which mentions
3319 -- the discriminant of an Unchecked_Union in non-Ada 2012
3320 -- code, this check is applied to all versions of the
3323 elsif Ekind (Comp) = E_Discriminant
3324 and then Is_Unchecked_Union (Rectype)
3327 ("cannot reference discriminant of Unchecked_Union",
3328 Component_Name (CC));
3330 elsif Present (Component_Clause (Comp)) then
3332 -- Diagnose duplicate rep clause, or check consistency
3333 -- if this is an inherited component. In a double fault,
3334 -- there may be a duplicate inconsistent clause for an
3335 -- inherited component.
3337 if Scope (Original_Record_Component (Comp)) = Rectype
3338 or else Parent (Component_Clause (Comp)) = N
3340 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
3341 Error_Msg_N ("component clause previously given#", CC);
3345 Rep1 : constant Node_Id := Component_Clause (Comp);
3347 if Intval (Position (Rep1)) /=
3348 Intval (Position (CC))
3349 or else Intval (First_Bit (Rep1)) /=
3350 Intval (First_Bit (CC))
3351 or else Intval (Last_Bit (Rep1)) /=
3352 Intval (Last_Bit (CC))
3354 Error_Msg_N ("component clause inconsistent "
3355 & "with representation of ancestor", CC);
3356 elsif Warn_On_Redundant_Constructs then
3357 Error_Msg_N ("?redundant component clause "
3358 & "for inherited component!", CC);
3363 -- Normal case where this is the first component clause we
3364 -- have seen for this entity, so set it up properly.
3367 -- Make reference for field in record rep clause and set
3368 -- appropriate entity field in the field identifier.
3371 (Comp, Component_Name (CC), Set_Ref => False);
3372 Set_Entity (Component_Name (CC), Comp);
3374 -- Update Fbit and Lbit to the actual bit number
3376 Fbit := Fbit + UI_From_Int (SSU) * Posit;
3377 Lbit := Lbit + UI_From_Int (SSU) * Posit;
3379 if Has_Size_Clause (Rectype)
3380 and then Esize (Rectype) <= Lbit
3383 ("bit number out of range of specified size",
3386 Set_Component_Clause (Comp, CC);
3387 Set_Component_Bit_Offset (Comp, Fbit);
3388 Set_Esize (Comp, 1 + (Lbit - Fbit));
3389 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
3390 Set_Normalized_Position (Comp, Fbit / SSU);
3392 if Warn_On_Overridden_Size
3393 and then Has_Size_Clause (Etype (Comp))
3394 and then RM_Size (Etype (Comp)) /= Esize (Comp)
3397 ("?component size overrides size clause for&",
3398 Component_Name (CC), Etype (Comp));
3401 -- This information is also set in the corresponding
3402 -- component of the base type, found by accessing the
3403 -- Original_Record_Component link if it is present.
3405 Ocomp := Original_Record_Component (Comp);
3412 (Component_Name (CC),
3418 (Comp, First_Node (CC), "component clause", Biased);
3420 if Present (Ocomp) then
3421 Set_Component_Clause (Ocomp, CC);
3422 Set_Component_Bit_Offset (Ocomp, Fbit);
3423 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
3424 Set_Normalized_Position (Ocomp, Fbit / SSU);
3425 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
3427 Set_Normalized_Position_Max
3428 (Ocomp, Normalized_Position (Ocomp));
3430 -- Note: we don't use Set_Biased here, because we
3431 -- already gave a warning above if needed, and we
3432 -- would get a duplicate for the same name here.
3434 Set_Has_Biased_Representation
3435 (Ocomp, Has_Biased_Representation (Comp));
3438 if Esize (Comp) < 0 then
3439 Error_Msg_N ("component size is negative", CC);
3450 -- Check missing components if Complete_Representation pragma appeared
3452 if Present (CR_Pragma) then
3453 Comp := First_Component_Or_Discriminant (Rectype);
3454 while Present (Comp) loop
3455 if No (Component_Clause (Comp)) then
3457 ("missing component clause for &", CR_Pragma, Comp);
3460 Next_Component_Or_Discriminant (Comp);
3463 -- If no Complete_Representation pragma, warn if missing components
3465 elsif Warn_On_Unrepped_Components then
3467 Num_Repped_Components : Nat := 0;
3468 Num_Unrepped_Components : Nat := 0;
3471 -- First count number of repped and unrepped components
3473 Comp := First_Component_Or_Discriminant (Rectype);
3474 while Present (Comp) loop
3475 if Present (Component_Clause (Comp)) then
3476 Num_Repped_Components := Num_Repped_Components + 1;
3478 Num_Unrepped_Components := Num_Unrepped_Components + 1;
3481 Next_Component_Or_Discriminant (Comp);
3484 -- We are only interested in the case where there is at least one
3485 -- unrepped component, and at least half the components have rep
3486 -- clauses. We figure that if less than half have them, then the
3487 -- partial rep clause is really intentional. If the component
3488 -- type has no underlying type set at this point (as for a generic
3489 -- formal type), we don't know enough to give a warning on the
3492 if Num_Unrepped_Components > 0
3493 and then Num_Unrepped_Components < Num_Repped_Components
3495 Comp := First_Component_Or_Discriminant (Rectype);
3496 while Present (Comp) loop
3497 if No (Component_Clause (Comp))
3498 and then Comes_From_Source (Comp)
3499 and then Present (Underlying_Type (Etype (Comp)))
3500 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
3501 or else Size_Known_At_Compile_Time
3502 (Underlying_Type (Etype (Comp))))
3503 and then not Has_Warnings_Off (Rectype)
3505 Error_Msg_Sloc := Sloc (Comp);
3507 ("?no component clause given for & declared #",
3511 Next_Component_Or_Discriminant (Comp);
3516 end Analyze_Record_Representation_Clause;
3518 -------------------------------
3519 -- Build_Invariant_Procedure --
3520 -------------------------------
3522 -- The procedure that is constructed here has the form
3524 -- procedure typInvariant (Ixxx : typ) is
3526 -- pragma Check (Invariant, exp, "failed invariant from xxx");
3527 -- pragma Check (Invariant, exp, "failed invariant from xxx");
3529 -- pragma Check (Invariant, exp, "failed inherited invariant from xxx");
3531 -- end typInvariant;
3533 procedure Build_Invariant_Procedure
3535 PDecl : out Node_Id;
3536 PBody : out Node_Id)
3538 Loc : constant Source_Ptr := Sloc (Typ);
3543 procedure Add_Invariants (T : Entity_Id; Inherit : Boolean);
3544 -- Appends statements to Stmts for any invariants in the rep item chain
3545 -- of the given type. If Inherit is False, then we only process entries
3546 -- on the chain for the type Typ. If Inherit is True, then we ignore any
3547 -- Invariant aspects, but we process all Invariant'Class aspects, adding
3548 -- "inherited" to the exception message and generating an informational
3549 -- message about the inheritance of an invariant.
3551 Object_Name : constant Name_Id := New_Internal_Name ('I');
3552 -- Name for argument of invariant procedure
3554 --------------------
3555 -- Add_Invariants --
3556 --------------------
3558 procedure Add_Invariants (T : Entity_Id; Inherit : Boolean) is
3568 function Replace_Node (N : Node_Id) return Traverse_Result;
3569 -- Process single node for traversal to replace type references
3571 procedure Replace_Type is new Traverse_Proc (Replace_Node);
3572 -- Traverse an expression changing every occurrence of an entity
3573 -- reference to type T with a reference to the object argument.
3579 function Replace_Node (N : Node_Id) return Traverse_Result is
3581 -- Case of entity name referencing the type
3583 if Is_Entity_Name (N)
3584 and then Entity (N) = T
3586 -- Invariant'Class, replace with T'Class (obj)
3588 if Class_Present (Ritem) then
3590 Make_Type_Conversion (Loc,
3592 Make_Attribute_Reference (Loc,
3594 New_Occurrence_Of (T, Loc),
3595 Attribute_Name => Name_Class),
3597 Make_Identifier (Loc,
3598 Chars => Object_Name)));
3600 -- Invariant, replace with obj
3604 Make_Identifier (Loc,
3605 Chars => Object_Name));
3608 -- All done with this node
3612 -- Not an instance of the type entity, keep going
3619 -- Start of processing for Add_Invariants
3622 Ritem := First_Rep_Item (T);
3623 while Present (Ritem) loop
3624 if Nkind (Ritem) = N_Pragma
3625 and then Pragma_Name (Ritem) = Name_Invariant
3627 Arg1 := First (Pragma_Argument_Associations (Ritem));
3628 Arg2 := Next (Arg1);
3629 Arg3 := Next (Arg2);
3631 Arg1 := Get_Pragma_Arg (Arg1);
3632 Arg2 := Get_Pragma_Arg (Arg2);
3634 -- For Inherit case, ignore Invariant, process only Class case
3637 if not Class_Present (Ritem) then
3641 -- For Inherit false, process only item for right type
3644 if Entity (Arg1) /= Typ then
3650 Stmts := Empty_List;
3653 Exp := New_Copy_Tree (Arg2);
3656 -- We need to replace any occurrences of the name of the type
3657 -- with references to the object, converted to type'Class in
3658 -- the case of Invariant'Class aspects. We do this by first
3659 -- doing a preanalysis, to identify all the entities, then
3660 -- we traverse looking for the type entity, and doing the
3661 -- necessary substitution. The preanalysis is done with the
3662 -- special OK_To_Reference flag set on the type, so that if
3663 -- we get an occurrence of this type, it will be reognized
3666 Set_OK_To_Reference (T, True);
3667 Preanalyze_Spec_Expression (Exp, Standard_Boolean);
3668 Set_OK_To_Reference (T, False);
3674 -- Build first two arguments for Check pragma
3677 Make_Pragma_Argument_Association (Loc,
3679 Make_Identifier (Loc,
3680 Chars => Name_Invariant)),
3681 Make_Pragma_Argument_Association (Loc,
3682 Expression => Exp));
3684 -- Add message if present in Invariant pragma
3686 if Present (Arg3) then
3687 Str := Strval (Get_Pragma_Arg (Arg3));
3689 -- If inherited case, and message starts "failed invariant",
3690 -- change it to be "failed inherited invariant".
3693 String_To_Name_Buffer (Str);
3695 if Name_Buffer (1 .. 16) = "failed invariant" then
3696 Insert_Str_In_Name_Buffer ("inherited ", 8);
3697 Str := String_From_Name_Buffer;
3702 Make_Pragma_Argument_Association (Loc,
3703 Expression => Make_String_Literal (Loc, Str)));
3706 -- Add Check pragma to list of statements
3710 Pragma_Identifier =>
3711 Make_Identifier (Loc,
3712 Chars => Name_Check),
3713 Pragma_Argument_Associations => Assoc));
3715 -- If Inherited case and option enabled, output info msg. Note
3716 -- that we know this is a case of Invariant'Class.
3718 if Inherit and Opt.List_Inherited_Aspects then
3719 Error_Msg_Sloc := Sloc (Ritem);
3721 ("?info: & inherits `Invariant''Class` aspect from #",
3727 Next_Rep_Item (Ritem);
3731 -- Start of processing for Build_Invariant_Procedure
3738 -- Add invariants for the current type
3740 Add_Invariants (Typ, Inherit => False);
3742 -- Add invariants for parent types
3745 Current_Typ : Entity_Id;
3746 Parent_Typ : Entity_Id;
3751 Parent_Typ := Etype (Current_Typ);
3753 if Is_Private_Type (Parent_Typ)
3754 and then Present (Full_View (Base_Type (Parent_Typ)))
3756 Parent_Typ := Full_View (Base_Type (Parent_Typ));
3759 exit when Parent_Typ = Current_Typ;
3761 Current_Typ := Parent_Typ;
3762 Add_Invariants (Current_Typ, Inherit => True);
3766 -- Build the procedure if we generated at least one Check pragma
3768 if Stmts /= No_List then
3770 -- Build procedure declaration
3772 pragma Assert (Has_Invariants (Typ));
3774 Make_Defining_Identifier (Loc,
3775 Chars => New_External_Name (Chars (Typ), "Invariant"));
3776 Set_Has_Invariants (SId);
3777 Set_Invariant_Procedure (Typ, SId);
3780 Make_Procedure_Specification (Loc,
3781 Defining_Unit_Name => SId,
3782 Parameter_Specifications => New_List (
3783 Make_Parameter_Specification (Loc,
3784 Defining_Identifier =>
3785 Make_Defining_Identifier (Loc,
3786 Chars => Object_Name),
3788 New_Occurrence_Of (Typ, Loc))));
3791 Make_Subprogram_Declaration (Loc,
3792 Specification => Spec);
3794 -- Build procedure body
3797 Make_Defining_Identifier (Loc,
3798 Chars => New_External_Name (Chars (Typ), "Invariant"));
3801 Make_Procedure_Specification (Loc,
3802 Defining_Unit_Name => SId,
3803 Parameter_Specifications => New_List (
3804 Make_Parameter_Specification (Loc,
3805 Defining_Identifier =>
3806 Make_Defining_Identifier (Loc,
3807 Chars => Object_Name),
3809 New_Occurrence_Of (Typ, Loc))));
3812 Make_Subprogram_Body (Loc,
3813 Specification => Spec,
3814 Declarations => Empty_List,
3815 Handled_Statement_Sequence =>
3816 Make_Handled_Sequence_Of_Statements (Loc,
3817 Statements => Stmts));
3819 end Build_Invariant_Procedure;
3821 ------------------------------
3822 -- Build_Predicate_Function --
3823 ------------------------------
3825 -- The procedure that is constructed here has the form
3827 -- function typPredicate (Ixxx : typ) return Boolean is
3830 -- exp1 and then exp2 and then ...
3831 -- and then typ1Predicate (typ1 (Ixxx))
3832 -- and then typ2Predicate (typ2 (Ixxx))
3834 -- end typPredicate;
3836 -- Here exp1, and exp2 are expressions from Predicate pragmas. Note that
3837 -- this is the point at which these expressions get analyzed, providing the
3838 -- required delay, and typ1, typ2, are entities from which predicates are
3839 -- inherited. Note that we do NOT generate Check pragmas, that's because we
3840 -- use this function even if checks are off, e.g. for membership tests.
3842 procedure Build_Predicate_Function
3844 FDecl : out Node_Id;
3845 FBody : out Node_Id)
3847 Loc : constant Source_Ptr := Sloc (Typ);
3852 -- This is the expression for the return statement in the function. It
3853 -- is build by connecting the component predicates with AND THEN.
3855 procedure Add_Call (T : Entity_Id);
3856 -- Includes a call to the predicate function for type T in Expr if T
3857 -- has predicates and Predicate_Function (T) is non-empty.
3859 procedure Add_Predicates;
3860 -- Appends expressions for any Predicate pragmas in the rep item chain
3861 -- Typ to Expr. Note that we look only at items for this exact entity.
3862 -- Inheritance of predicates for the parent type is done by calling the
3863 -- Predicate_Function of the parent type, using Add_Call above.
3865 Object_Name : constant Name_Id := New_Internal_Name ('I');
3866 -- Name for argument of Predicate procedure
3872 procedure Add_Call (T : Entity_Id) is
3876 if Present (T) and then Present (Predicate_Function (T)) then
3877 Set_Has_Predicates (Typ);
3879 -- Build the call to the predicate function of T
3885 Make_Identifier (Loc, Chars => Object_Name)));
3887 -- Add call to evolving expression, using AND THEN if needed
3894 Left_Opnd => Relocate_Node (Expr),
3898 -- Output info message on inheritance if required. Note we do not
3899 -- give this information for generic actual types, since it is
3900 -- unwelcome noise in that case in instantiations. We also
3901 -- generally suppress the message in instantiations.
3903 if Opt.List_Inherited_Aspects
3904 and then not Is_Generic_Actual_Type (Typ)
3905 and then Instantiation_Depth (Sloc (Typ)) = 0
3907 Error_Msg_Sloc := Sloc (Predicate_Function (T));
3908 Error_Msg_Node_2 := T;
3909 Error_Msg_N ("?info: & inherits predicate from & #", Typ);
3914 --------------------
3915 -- Add_Predicates --
3916 --------------------
3918 procedure Add_Predicates is
3923 function Replace_Node (N : Node_Id) return Traverse_Result;
3924 -- Process single node for traversal to replace type references
3926 procedure Replace_Type is new Traverse_Proc (Replace_Node);
3927 -- Traverse an expression changing every occurrence of an entity
3928 -- reference to type T with a reference to the object argument.
3934 function Replace_Node (N : Node_Id) return Traverse_Result is
3936 -- Case of entity name referencing the type
3938 if Is_Entity_Name (N) and then Entity (N) = Typ then
3940 -- Replace with object
3943 Make_Identifier (Loc,
3944 Chars => Object_Name));
3946 -- All done with this node
3950 -- Not an occurrence of the type entity, keep going
3957 -- Start of processing for Add_Predicates
3960 Ritem := First_Rep_Item (Typ);
3961 while Present (Ritem) loop
3962 if Nkind (Ritem) = N_Pragma
3963 and then Pragma_Name (Ritem) = Name_Predicate
3965 Arg1 := First (Pragma_Argument_Associations (Ritem));
3966 Arg2 := Next (Arg1);
3968 Arg1 := Get_Pragma_Arg (Arg1);
3969 Arg2 := Get_Pragma_Arg (Arg2);
3971 -- See if this predicate pragma is for the current type
3973 if Entity (Arg1) = Typ then
3975 -- We have a match, this entry is for our subtype
3977 -- First We need to replace any occurrences of the name of
3978 -- the type with references to the object. We do this by
3979 -- first doing a preanalysis, to identify all the entities,
3980 -- then we traverse looking for the type entity, doing the
3981 -- needed substitution. The preanalysis is done with the
3982 -- special OK_To_Reference flag set on the type, so that if
3983 -- we get an occurrence of this type, it will be recognized
3986 Set_OK_To_Reference (Typ, True);
3987 Preanalyze_Spec_Expression (Arg2, Standard_Boolean);
3988 Set_OK_To_Reference (Typ, False);
3989 Replace_Type (Arg2);
3991 -- OK, replacement complete, now we can add the expression
3994 Expr := Relocate_Node (Arg2);
3996 -- There already was a predicate, so add to it
4001 Left_Opnd => Relocate_Node (Expr),
4002 Right_Opnd => Relocate_Node (Arg2));
4007 Next_Rep_Item (Ritem);
4011 -- Start of processing for Build_Predicate_Function
4014 -- Initialize for construction of statement list
4020 -- Return if already built or if type does not have predicates
4022 if not Has_Predicates (Typ)
4023 or else Present (Predicate_Function (Typ))
4028 -- Add Predicates for the current type
4032 -- Add predicates for ancestor if present
4035 Atyp : constant Entity_Id := Nearest_Ancestor (Typ);
4037 if Present (Atyp) then
4042 -- If we have predicates, build the function
4044 if Present (Expr) then
4046 -- Deal with static predicate case
4048 if Ekind_In (Typ, E_Enumeration_Subtype,
4049 E_Modular_Integer_Subtype,
4050 E_Signed_Integer_Subtype)
4051 and then Is_Static_Subtype (Typ)
4053 Build_Static_Predicate (Typ, Expr, Object_Name);
4056 -- Build function declaration
4058 pragma Assert (Has_Predicates (Typ));
4060 Make_Defining_Identifier (Loc,
4061 Chars => New_External_Name (Chars (Typ), "Predicate"));
4062 Set_Has_Predicates (SId);
4063 Set_Predicate_Function (Typ, SId);
4066 Make_Function_Specification (Loc,
4067 Defining_Unit_Name => SId,
4068 Parameter_Specifications => New_List (
4069 Make_Parameter_Specification (Loc,
4070 Defining_Identifier =>
4071 Make_Defining_Identifier (Loc, Chars => Object_Name),
4072 Parameter_Type => New_Occurrence_Of (Typ, Loc))),
4073 Result_Definition =>
4074 New_Occurrence_Of (Standard_Boolean, Loc));
4077 Make_Subprogram_Declaration (Loc,
4078 Specification => Spec);
4080 -- Build function body
4083 Make_Defining_Identifier (Loc,
4084 Chars => New_External_Name (Chars (Typ), "Predicate"));
4087 Make_Function_Specification (Loc,
4088 Defining_Unit_Name => SId,
4089 Parameter_Specifications => New_List (
4090 Make_Parameter_Specification (Loc,
4091 Defining_Identifier =>
4092 Make_Defining_Identifier (Loc, Chars => Object_Name),
4094 New_Occurrence_Of (Typ, Loc))),
4095 Result_Definition =>
4096 New_Occurrence_Of (Standard_Boolean, Loc));
4099 Make_Subprogram_Body (Loc,
4100 Specification => Spec,
4101 Declarations => Empty_List,
4102 Handled_Statement_Sequence =>
4103 Make_Handled_Sequence_Of_Statements (Loc,
4104 Statements => New_List (
4105 Make_Simple_Return_Statement (Loc,
4106 Expression => Expr))));
4108 end Build_Predicate_Function;
4110 ----------------------------
4111 -- Build_Static_Predicate --
4112 ----------------------------
4114 procedure Build_Static_Predicate
4119 Loc : constant Source_Ptr := Sloc (Expr);
4121 Non_Static : exception;
4122 -- Raised if something non-static is found
4124 Btyp : constant Entity_Id := Base_Type (Typ);
4126 BLo : constant Uint := Expr_Value (Type_Low_Bound (Btyp));
4127 BHi : constant Uint := Expr_Value (Type_High_Bound (Btyp));
4128 -- Low bound and high bound value of base type of Typ
4130 TLo : constant Uint := Expr_Value (Type_Low_Bound (Typ));
4131 THi : constant Uint := Expr_Value (Type_High_Bound (Typ));
4132 -- Low bound and high bound values of static subtype Typ
4137 -- One entry in a Rlist value, a single REnt (range entry) value
4138 -- denotes one range from Lo to Hi. To represent a single value
4139 -- range Lo = Hi = value.
4141 type RList is array (Nat range <>) of REnt;
4142 -- A list of ranges. The ranges are sorted in increasing order,
4143 -- and are disjoint (there is a gap of at least one value between
4144 -- each range in the table). A value is in the set of ranges in
4145 -- Rlist if it lies within one of these ranges
4147 False_Range : constant RList :=
4148 RList'(1 .. 0 => REnt'(No_Uint, No_Uint));
4149 -- An empty set of ranges represents a range list that can never be
4150 -- satisfied, since there are no ranges in which the value could lie,
4151 -- so it does not lie in any of them. False_Range is a canonical value
4152 -- for this empty set, but general processing should test for an Rlist
4153 -- with length zero (see Is_False predicate), since other null ranges
4154 -- may appear which must be treated as False.
4156 True_Range : constant RList := RList'(1 => REnt'(BLo, BHi));
4157 -- Range representing True, value must be in the base range
4159 function "and" (Left, Right : RList) return RList;
4160 -- And's together two range lists, returning a range list. This is
4161 -- a set intersection operation.
4163 function "or" (Left, Right : RList) return RList;
4164 -- Or's together two range lists, returning a range list. This is a
4165 -- set union operation.
4167 function "not" (Right : RList) return RList;
4168 -- Returns complement of a given range list, i.e. a range list
4169 -- representing all the values in TLo .. THi that are not in the
4170 -- input operand Right.
4172 function Build_Val (V : Uint) return Node_Id;
4173 -- Return an analyzed N_Identifier node referencing this value, suitable
4174 -- for use as an entry in the Static_Predicate list. This node is typed
4175 -- with the base type.
4177 function Build_Range (Lo, Hi : Uint) return Node_Id;
4178 -- Return an analyzed N_Range node referencing this range, suitable
4179 -- for use as an entry in the Static_Predicate list. This node is typed
4180 -- with the base type.
4182 function Get_RList (Exp : Node_Id) return RList;
4183 -- This is a recursive routine that converts the given expression into
4184 -- a list of ranges, suitable for use in building the static predicate.
4186 function Is_False (R : RList) return Boolean;
4187 pragma Inline (Is_False);
4188 -- Returns True if the given range list is empty, and thus represents
4189 -- a False list of ranges that can never be satsified.
4191 function Is_True (R : RList) return Boolean;
4192 -- Returns True if R trivially represents the True predicate by having
4193 -- a single range from BLo to BHi.
4195 function Is_Type_Ref (N : Node_Id) return Boolean;
4196 pragma Inline (Is_Type_Ref);
4197 -- Returns if True if N is a reference to the type for the predicate in
4198 -- the expression (i.e. if it is an identifier whose Chars field matches
4199 -- the Nam given in the call).
4201 function Lo_Val (N : Node_Id) return Uint;
4202 -- Given static expression or static range from a Static_Predicate list,
4203 -- gets expression value or low bound of range.
4205 function Hi_Val (N : Node_Id) return Uint;
4206 -- Given static expression or static range from a Static_Predicate list,
4207 -- gets expression value of high bound of range.
4209 function Membership_Entry (N : Node_Id) return RList;
4210 -- Given a single membership entry (range, value, or subtype), returns
4211 -- the corresponding range list. Raises Static_Error if not static.
4213 function Membership_Entries (N : Node_Id) return RList;
4214 -- Given an element on an alternatives list of a membership operation,
4215 -- returns the range list corresponding to this entry and all following
4216 -- entries (i.e. returns the "or" of this list of values).
4218 function Stat_Pred (Typ : Entity_Id) return RList;
4219 -- Given a type, if it has a static predicate, then return the predicate
4220 -- as a range list, otherwise raise Non_Static.
4226 function "and" (Left, Right : RList) return RList is
4228 -- First range of result
4230 SLeft : Nat := Left'First;
4231 -- Start of rest of left entries
4233 SRight : Nat := Right'First;
4234 -- Start of rest of right entries
4237 -- If either range is True, return the other
4239 if Is_True (Left) then
4241 elsif Is_True (Right) then
4245 -- If either range is False, return False
4247 if Is_False (Left) or else Is_False (Right) then
4251 -- Loop to remove entries at start that are disjoint, and thus
4252 -- just get discarded from the result entirely.
4255 -- If no operands left in either operand, result is false
4257 if SLeft > Left'Last or else SRight > Right'Last then
4260 -- Discard first left operand entry if disjoint with right
4262 elsif Left (SLeft).Hi < Right (SRight).Lo then
4265 -- Discard first right operand entry if disjoint with left
4267 elsif Right (SRight).Hi < Left (SLeft).Lo then
4268 SRight := SRight + 1;
4270 -- Otherwise we have an overlapping entry
4277 -- Now we have two non-null operands, and first entries overlap.
4278 -- The first entry in the result will be the overlapping part of
4279 -- these two entries.
4281 FEnt := REnt'(Lo => UI_Max (Left (SLeft).Lo, Right (SRight).Lo),
4282 Hi => UI_Min (Left (SLeft).Hi, Right (SRight).Hi));
4284 -- Now we can remove the entry that ended at a lower value, since
4285 -- its contribution is entirely contained in Fent.
4287 if Left (SLeft).Hi <= Right (SRight).Hi then
4290 SRight := SRight + 1;
4293 -- Compute result by concatenating this first entry with the "and"
4294 -- of the remaining parts of the left and right operands. Note that
4295 -- if either of these is empty, "and" will yield empty, so that we
4296 -- will end up with just Fent, which is what we want in that case.
4299 FEnt & (Left (SLeft .. Left'Last) and Right (SRight .. Right'Last));
4306 function "not" (Right : RList) return RList is
4308 -- Return True if False range
4310 if Is_False (Right) then
4314 -- Return False if True range
4316 if Is_True (Right) then
4320 -- Here if not trivial case
4323 Result : RList (1 .. Right'Length + 1);
4324 -- May need one more entry for gap at beginning and end
4327 -- Number of entries stored in Result
4332 if Right (Right'First).Lo > TLo then
4334 Result (Count) := REnt'(TLo, Right (Right'First).Lo - 1);
4337 -- Gaps between ranges
4339 for J in Right'First .. Right'Last - 1 loop
4342 REnt'(Right (J).Hi + 1, Right (J + 1).Lo - 1);
4347 if Right (Right'Last).Hi < THi then
4349 Result (Count) := REnt'(Right (Right'Last).Hi + 1, THi);
4352 return Result (1 .. Count);
4360 function "or" (Left, Right : RList) return RList is
4362 -- First range of result
4364 SLeft : Nat := Left'First;
4365 -- Start of rest of left entries
4367 SRight : Nat := Right'First;
4368 -- Start of rest of right entries
4371 -- If either range is True, return True
4373 if Is_True (Left) or else Is_True (Right) then
4377 -- If either range is False (empty), return the other
4379 if Is_False (Left) then
4381 elsif Is_False (Right) then
4385 -- Initialize result first entry from left or right operand
4386 -- depending on which starts with the lower range.
4388 if Left (SLeft).Lo < Right (SRight).Lo then
4389 FEnt := Left (SLeft);
4392 FEnt := Right (SRight);
4393 SRight := SRight + 1;
4396 -- This loop eats ranges from left and right operands that
4397 -- are contiguous with the first range we are gathering.
4400 -- Eat first entry in left operand if contiguous or
4401 -- overlapped by gathered first operand of result.
4403 if SLeft <= Left'Last
4404 and then Left (SLeft).Lo <= FEnt.Hi + 1
4406 FEnt.Hi := UI_Max (FEnt.Hi, Left (SLeft).Hi);
4409 -- Eat first entry in right operand if contiguous or
4410 -- overlapped by gathered right operand of result.
4412 elsif SRight <= Right'Last
4413 and then Right (SRight).Lo <= FEnt.Hi + 1
4415 FEnt.Hi := UI_Max (FEnt.Hi, Right (SRight).Hi);
4416 SRight := SRight + 1;
4418 -- All done if no more entries to eat!
4425 -- Obtain result as the first entry we just computed, concatenated
4426 -- to the "or" of the remaining results (if one operand is empty,
4427 -- this will just concatenate with the other
4430 FEnt & (Left (SLeft .. Left'Last) or Right (SRight .. Right'Last));
4437 function Build_Range (Lo, Hi : Uint) return Node_Id is
4441 return Build_Val (Hi);
4445 Low_Bound => Build_Val (Lo),
4446 High_Bound => Build_Val (Hi));
4447 Set_Etype (Result, Btyp);
4448 Set_Analyzed (Result);
4457 function Build_Val (V : Uint) return Node_Id is
4461 if Is_Enumeration_Type (Typ) then
4462 Result := Get_Enum_Lit_From_Pos (Typ, V, Loc);
4464 Result := Make_Integer_Literal (Loc, Intval => V);
4467 Set_Etype (Result, Btyp);
4468 Set_Is_Static_Expression (Result);
4469 Set_Analyzed (Result);
4477 function Get_RList (Exp : Node_Id) return RList is
4482 -- Static expression can only be true or false
4484 if Is_OK_Static_Expression (Exp) then
4488 if Expr_Value (Exp) = 0 then
4495 -- Otherwise test node type
4503 when N_Op_And | N_And_Then =>
4504 return Get_RList (Left_Opnd (Exp))
4506 Get_RList (Right_Opnd (Exp));
4510 when N_Op_Or | N_Or_Else =>
4511 return Get_RList (Left_Opnd (Exp))
4513 Get_RList (Right_Opnd (Exp));
4518 return not Get_RList (Right_Opnd (Exp));
4520 -- Comparisons of type with static value
4522 when N_Op_Compare =>
4523 -- Type is left operand
4525 if Is_Type_Ref (Left_Opnd (Exp))
4526 and then Is_OK_Static_Expression (Right_Opnd (Exp))
4528 Val := Expr_Value (Right_Opnd (Exp));
4530 -- Typ is right operand
4532 elsif Is_Type_Ref (Right_Opnd (Exp))
4533 and then Is_OK_Static_Expression (Left_Opnd (Exp))
4535 Val := Expr_Value (Left_Opnd (Exp));
4537 -- Invert sense of comparison
4540 when N_Op_Gt => Op := N_Op_Lt;
4541 when N_Op_Lt => Op := N_Op_Gt;
4542 when N_Op_Ge => Op := N_Op_Le;
4543 when N_Op_Le => Op := N_Op_Ge;
4544 when others => null;
4547 -- Other cases are non-static
4553 -- Construct range according to comparison operation
4557 return RList'(1 => REnt'(Val, Val));
4560 return RList'(1 => REnt'(Val, BHi));
4563 return RList'(1 => REnt'(Val + 1, BHi));
4566 return RList'(1 => REnt'(BLo, Val));
4569 return RList'(1 => REnt'(BLo, Val - 1));
4572 return RList'(REnt'(BLo, Val - 1),
4573 REnt'(Val + 1, BHi));
4576 raise Program_Error;
4582 if not Is_Type_Ref (Left_Opnd (Exp)) then
4586 if Present (Right_Opnd (Exp)) then
4587 return Membership_Entry (Right_Opnd (Exp));
4589 return Membership_Entries (First (Alternatives (Exp)));
4592 -- Negative membership (NOT IN)
4595 if not Is_Type_Ref (Left_Opnd (Exp)) then
4599 if Present (Right_Opnd (Exp)) then
4600 return not Membership_Entry (Right_Opnd (Exp));
4602 return not Membership_Entries (First (Alternatives (Exp)));
4605 -- Function call, may be call to static predicate
4607 when N_Function_Call =>
4608 if Is_Entity_Name (Name (Exp)) then
4610 Ent : constant Entity_Id := Entity (Name (Exp));
4612 if Has_Predicates (Ent) then
4613 return Stat_Pred (Etype (First_Formal (Ent)));
4618 -- Other function call cases are non-static
4622 -- Qualified expression, dig out the expression
4624 when N_Qualified_Expression =>
4625 return Get_RList (Expression (Exp));
4630 return (Get_RList (Left_Opnd (Exp))
4631 and not Get_RList (Right_Opnd (Exp)))
4632 or (Get_RList (Right_Opnd (Exp))
4633 and not Get_RList (Left_Opnd (Exp)));
4635 -- Any other node type is non-static
4646 function Hi_Val (N : Node_Id) return Uint is
4648 if Is_Static_Expression (N) then
4649 return Expr_Value (N);
4651 pragma Assert (Nkind (N) = N_Range);
4652 return Expr_Value (High_Bound (N));
4660 function Is_False (R : RList) return Boolean is
4662 return R'Length = 0;
4669 function Is_True (R : RList) return Boolean is
4672 and then R (R'First).Lo = BLo
4673 and then R (R'First).Hi = BHi;
4680 function Is_Type_Ref (N : Node_Id) return Boolean is
4682 return Nkind (N) = N_Identifier and then Chars (N) = Nam;
4689 function Lo_Val (N : Node_Id) return Uint is
4691 if Is_Static_Expression (N) then
4692 return Expr_Value (N);
4694 pragma Assert (Nkind (N) = N_Range);
4695 return Expr_Value (Low_Bound (N));
4699 ------------------------
4700 -- Membership_Entries --
4701 ------------------------
4703 function Membership_Entries (N : Node_Id) return RList is
4705 if No (Next (N)) then
4706 return Membership_Entry (N);
4708 return Membership_Entry (N) or Membership_Entries (Next (N));
4710 end Membership_Entries;
4712 ----------------------
4713 -- Membership_Entry --
4714 ----------------------
4716 function Membership_Entry (N : Node_Id) return RList is
4724 if Nkind (N) = N_Range then
4725 if not Is_Static_Expression (Low_Bound (N))
4727 not Is_Static_Expression (High_Bound (N))
4731 SLo := Expr_Value (Low_Bound (N));
4732 SHi := Expr_Value (High_Bound (N));
4733 return RList'(1 => REnt'(SLo, SHi));
4736 -- Static expression case
4738 elsif Is_Static_Expression (N) then
4739 Val := Expr_Value (N);
4740 return RList'(1 => REnt'(Val, Val));
4742 -- Identifier (other than static expression) case
4744 else pragma Assert (Nkind (N) = N_Identifier);
4748 if Is_Type (Entity (N)) then
4750 -- If type has predicates, process them
4752 if Has_Predicates (Entity (N)) then
4753 return Stat_Pred (Entity (N));
4755 -- For static subtype without predicates, get range
4757 elsif Is_Static_Subtype (Entity (N)) then
4758 SLo := Expr_Value (Type_Low_Bound (Entity (N)));
4759 SHi := Expr_Value (Type_High_Bound (Entity (N)));
4760 return RList'(1 => REnt'(SLo, SHi));
4762 -- Any other type makes us non-static
4768 -- Any other kind of identifier in predicate (e.g. a non-static
4769 -- expression value) means this is not a static predicate.
4775 end Membership_Entry;
4781 function Stat_Pred (Typ : Entity_Id) return RList is
4783 -- Not static if type does not have static predicates
4785 if not Has_Predicates (Typ)
4786 or else No (Static_Predicate (Typ))
4791 -- Otherwise we convert the predicate list to a range list
4794 Result : RList (1 .. List_Length (Static_Predicate (Typ)));
4798 P := First (Static_Predicate (Typ));
4799 for J in Result'Range loop
4800 Result (J) := REnt'(Lo_Val (P), Hi_Val (P));
4808 -- Start of processing for Build_Static_Predicate
4811 -- Now analyze the expression to see if it is a static predicate
4814 Ranges : constant RList := Get_RList (Expr);
4815 -- Range list from expression if it is static
4820 -- Convert range list into a form for the static predicate. In the
4821 -- Ranges array, we just have raw ranges, these must be converted
4822 -- to properly typed and analyzed static expressions or range nodes.
4824 -- Note: here we limit ranges to the ranges of the subtype, so that
4825 -- a predicate is always false for values outside the subtype. That
4826 -- seems fine, such values are invalid anyway, and considering them
4827 -- to fail the predicate seems allowed and friendly, and furthermore
4828 -- simplifies processing for case statements and loops.
4832 for J in Ranges'Range loop
4834 Lo : Uint := Ranges (J).Lo;
4835 Hi : Uint := Ranges (J).Hi;
4838 -- Ignore completely out of range entry
4840 if Hi < TLo or else Lo > THi then
4843 -- Otherwise process entry
4846 -- Adjust out of range value to subtype range
4856 -- Convert range into required form
4859 Append_To (Plist, Build_Val (Lo));
4861 Append_To (Plist, Build_Range (Lo, Hi));
4867 -- Processing was successful and all entries were static, so now we
4868 -- can store the result as the predicate list.
4870 Set_Static_Predicate (Typ, Plist);
4872 -- The processing for static predicates put the expression into
4873 -- canonical form as a series of ranges. It also eliminated
4874 -- duplicates and collapsed and combined ranges. We might as well
4875 -- replace the alternatives list of the right operand of the
4876 -- membership test with the static predicate list, which will
4877 -- usually be more efficient.
4880 New_Alts : constant List_Id := New_List;
4885 Old_Node := First (Plist);
4886 while Present (Old_Node) loop
4887 New_Node := New_Copy (Old_Node);
4889 if Nkind (New_Node) = N_Range then
4890 Set_Low_Bound (New_Node, New_Copy (Low_Bound (Old_Node)));
4891 Set_High_Bound (New_Node, New_Copy (High_Bound (Old_Node)));
4894 Append_To (New_Alts, New_Node);
4898 -- If empty list, replace by False
4900 if Is_Empty_List (New_Alts) then
4901 Rewrite (Expr, New_Occurrence_Of (Standard_False, Loc));
4903 -- Else replace by set membership test
4908 Left_Opnd => Make_Identifier (Loc, Nam),
4909 Right_Opnd => Empty,
4910 Alternatives => New_Alts));
4915 -- If non-static, return doing nothing
4920 end Build_Static_Predicate;
4922 -----------------------------------
4923 -- Check_Constant_Address_Clause --
4924 -----------------------------------
4926 procedure Check_Constant_Address_Clause
4930 procedure Check_At_Constant_Address (Nod : Node_Id);
4931 -- Checks that the given node N represents a name whose 'Address is
4932 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
4933 -- address value is the same at the point of declaration of U_Ent and at
4934 -- the time of elaboration of the address clause.
4936 procedure Check_Expr_Constants (Nod : Node_Id);
4937 -- Checks that Nod meets the requirements for a constant address clause
4938 -- in the sense of the enclosing procedure.
4940 procedure Check_List_Constants (Lst : List_Id);
4941 -- Check that all elements of list Lst meet the requirements for a
4942 -- constant address clause in the sense of the enclosing procedure.
4944 -------------------------------
4945 -- Check_At_Constant_Address --
4946 -------------------------------
4948 procedure Check_At_Constant_Address (Nod : Node_Id) is
4950 if Is_Entity_Name (Nod) then
4951 if Present (Address_Clause (Entity ((Nod)))) then
4953 ("invalid address clause for initialized object &!",
4956 ("address for& cannot" &
4957 " depend on another address clause! (RM 13.1(22))!",
4960 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
4961 and then Sloc (U_Ent) < Sloc (Entity (Nod))
4964 ("invalid address clause for initialized object &!",
4966 Error_Msg_Node_2 := U_Ent;
4968 ("\& must be defined before & (RM 13.1(22))!",
4972 elsif Nkind (Nod) = N_Selected_Component then
4974 T : constant Entity_Id := Etype (Prefix (Nod));
4977 if (Is_Record_Type (T)
4978 and then Has_Discriminants (T))
4981 and then Is_Record_Type (Designated_Type (T))
4982 and then Has_Discriminants (Designated_Type (T)))
4985 ("invalid address clause for initialized object &!",
4988 ("\address cannot depend on component" &
4989 " of discriminated record (RM 13.1(22))!",
4992 Check_At_Constant_Address (Prefix (Nod));
4996 elsif Nkind (Nod) = N_Indexed_Component then
4997 Check_At_Constant_Address (Prefix (Nod));
4998 Check_List_Constants (Expressions (Nod));
5001 Check_Expr_Constants (Nod);
5003 end Check_At_Constant_Address;
5005 --------------------------
5006 -- Check_Expr_Constants --
5007 --------------------------
5009 procedure Check_Expr_Constants (Nod : Node_Id) is
5010 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
5011 Ent : Entity_Id := Empty;
5014 if Nkind (Nod) in N_Has_Etype
5015 and then Etype (Nod) = Any_Type
5021 when N_Empty | N_Error =>
5024 when N_Identifier | N_Expanded_Name =>
5025 Ent := Entity (Nod);
5027 -- We need to look at the original node if it is different
5028 -- from the node, since we may have rewritten things and
5029 -- substituted an identifier representing the rewrite.
5031 if Original_Node (Nod) /= Nod then
5032 Check_Expr_Constants (Original_Node (Nod));
5034 -- If the node is an object declaration without initial
5035 -- value, some code has been expanded, and the expression
5036 -- is not constant, even if the constituents might be
5037 -- acceptable, as in A'Address + offset.
5039 if Ekind (Ent) = E_Variable
5041 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
5043 No (Expression (Declaration_Node (Ent)))
5046 ("invalid address clause for initialized object &!",
5049 -- If entity is constant, it may be the result of expanding
5050 -- a check. We must verify that its declaration appears
5051 -- before the object in question, else we also reject the
5054 elsif Ekind (Ent) = E_Constant
5055 and then In_Same_Source_Unit (Ent, U_Ent)
5056 and then Sloc (Ent) > Loc_U_Ent
5059 ("invalid address clause for initialized object &!",
5066 -- Otherwise look at the identifier and see if it is OK
5068 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
5069 or else Is_Type (Ent)
5074 Ekind (Ent) = E_Constant
5076 Ekind (Ent) = E_In_Parameter
5078 -- This is the case where we must have Ent defined before
5079 -- U_Ent. Clearly if they are in different units this
5080 -- requirement is met since the unit containing Ent is
5081 -- already processed.
5083 if not In_Same_Source_Unit (Ent, U_Ent) then
5086 -- Otherwise location of Ent must be before the location
5087 -- of U_Ent, that's what prior defined means.
5089 elsif Sloc (Ent) < Loc_U_Ent then
5094 ("invalid address clause for initialized object &!",
5096 Error_Msg_Node_2 := U_Ent;
5098 ("\& must be defined before & (RM 13.1(22))!",
5102 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
5103 Check_Expr_Constants (Original_Node (Nod));
5107 ("invalid address clause for initialized object &!",
5110 if Comes_From_Source (Ent) then
5112 ("\reference to variable& not allowed"
5113 & " (RM 13.1(22))!", Nod, Ent);
5116 ("non-static expression not allowed"
5117 & " (RM 13.1(22))!", Nod);
5121 when N_Integer_Literal =>
5123 -- If this is a rewritten unchecked conversion, in a system
5124 -- where Address is an integer type, always use the base type
5125 -- for a literal value. This is user-friendly and prevents
5126 -- order-of-elaboration issues with instances of unchecked
5129 if Nkind (Original_Node (Nod)) = N_Function_Call then
5130 Set_Etype (Nod, Base_Type (Etype (Nod)));
5133 when N_Real_Literal |
5135 N_Character_Literal =>
5139 Check_Expr_Constants (Low_Bound (Nod));
5140 Check_Expr_Constants (High_Bound (Nod));
5142 when N_Explicit_Dereference =>
5143 Check_Expr_Constants (Prefix (Nod));
5145 when N_Indexed_Component =>
5146 Check_Expr_Constants (Prefix (Nod));
5147 Check_List_Constants (Expressions (Nod));
5150 Check_Expr_Constants (Prefix (Nod));
5151 Check_Expr_Constants (Discrete_Range (Nod));
5153 when N_Selected_Component =>
5154 Check_Expr_Constants (Prefix (Nod));
5156 when N_Attribute_Reference =>
5157 if Attribute_Name (Nod) = Name_Address
5159 Attribute_Name (Nod) = Name_Access
5161 Attribute_Name (Nod) = Name_Unchecked_Access
5163 Attribute_Name (Nod) = Name_Unrestricted_Access
5165 Check_At_Constant_Address (Prefix (Nod));
5168 Check_Expr_Constants (Prefix (Nod));
5169 Check_List_Constants (Expressions (Nod));
5173 Check_List_Constants (Component_Associations (Nod));
5174 Check_List_Constants (Expressions (Nod));
5176 when N_Component_Association =>
5177 Check_Expr_Constants (Expression (Nod));
5179 when N_Extension_Aggregate =>
5180 Check_Expr_Constants (Ancestor_Part (Nod));
5181 Check_List_Constants (Component_Associations (Nod));
5182 Check_List_Constants (Expressions (Nod));
5187 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
5188 Check_Expr_Constants (Left_Opnd (Nod));
5189 Check_Expr_Constants (Right_Opnd (Nod));
5192 Check_Expr_Constants (Right_Opnd (Nod));
5194 when N_Type_Conversion |
5195 N_Qualified_Expression |
5197 Check_Expr_Constants (Expression (Nod));
5199 when N_Unchecked_Type_Conversion =>
5200 Check_Expr_Constants (Expression (Nod));
5202 -- If this is a rewritten unchecked conversion, subtypes in
5203 -- this node are those created within the instance. To avoid
5204 -- order of elaboration issues, replace them with their base
5205 -- types. Note that address clauses can cause order of
5206 -- elaboration problems because they are elaborated by the
5207 -- back-end at the point of definition, and may mention
5208 -- entities declared in between (as long as everything is
5209 -- static). It is user-friendly to allow unchecked conversions
5212 if Nkind (Original_Node (Nod)) = N_Function_Call then
5213 Set_Etype (Expression (Nod),
5214 Base_Type (Etype (Expression (Nod))));
5215 Set_Etype (Nod, Base_Type (Etype (Nod)));
5218 when N_Function_Call =>
5219 if not Is_Pure (Entity (Name (Nod))) then
5221 ("invalid address clause for initialized object &!",
5225 ("\function & is not pure (RM 13.1(22))!",
5226 Nod, Entity (Name (Nod)));
5229 Check_List_Constants (Parameter_Associations (Nod));
5232 when N_Parameter_Association =>
5233 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
5237 ("invalid address clause for initialized object &!",
5240 ("\must be constant defined before& (RM 13.1(22))!",
5243 end Check_Expr_Constants;
5245 --------------------------
5246 -- Check_List_Constants --
5247 --------------------------
5249 procedure Check_List_Constants (Lst : List_Id) is
5253 if Present (Lst) then
5254 Nod1 := First (Lst);
5255 while Present (Nod1) loop
5256 Check_Expr_Constants (Nod1);
5260 end Check_List_Constants;
5262 -- Start of processing for Check_Constant_Address_Clause
5265 -- If rep_clauses are to be ignored, no need for legality checks. In
5266 -- particular, no need to pester user about rep clauses that violate
5267 -- the rule on constant addresses, given that these clauses will be
5268 -- removed by Freeze before they reach the back end.
5270 if not Ignore_Rep_Clauses then
5271 Check_Expr_Constants (Expr);
5273 end Check_Constant_Address_Clause;
5275 ----------------------------------------
5276 -- Check_Record_Representation_Clause --
5277 ----------------------------------------
5279 procedure Check_Record_Representation_Clause (N : Node_Id) is
5280 Loc : constant Source_Ptr := Sloc (N);
5281 Ident : constant Node_Id := Identifier (N);
5282 Rectype : Entity_Id;
5287 Hbit : Uint := Uint_0;
5291 Max_Bit_So_Far : Uint;
5292 -- Records the maximum bit position so far. If all field positions
5293 -- are monotonically increasing, then we can skip the circuit for
5294 -- checking for overlap, since no overlap is possible.
5296 Tagged_Parent : Entity_Id := Empty;
5297 -- This is set in the case of a derived tagged type for which we have
5298 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
5299 -- positioned by record representation clauses). In this case we must
5300 -- check for overlap between components of this tagged type, and the
5301 -- components of its parent. Tagged_Parent will point to this parent
5302 -- type. For all other cases Tagged_Parent is left set to Empty.
5304 Parent_Last_Bit : Uint;
5305 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
5306 -- last bit position for any field in the parent type. We only need to
5307 -- check overlap for fields starting below this point.
5309 Overlap_Check_Required : Boolean;
5310 -- Used to keep track of whether or not an overlap check is required
5312 Overlap_Detected : Boolean := False;
5313 -- Set True if an overlap is detected
5315 Ccount : Natural := 0;
5316 -- Number of component clauses in record rep clause
5318 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
5319 -- Given two entities for record components or discriminants, checks
5320 -- if they have overlapping component clauses and issues errors if so.
5322 procedure Find_Component;
5323 -- Finds component entity corresponding to current component clause (in
5324 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
5325 -- start/stop bits for the field. If there is no matching component or
5326 -- if the matching component does not have a component clause, then
5327 -- that's an error and Comp is set to Empty, but no error message is
5328 -- issued, since the message was already given. Comp is also set to
5329 -- Empty if the current "component clause" is in fact a pragma.
5331 -----------------------------
5332 -- Check_Component_Overlap --
5333 -----------------------------
5335 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
5336 CC1 : constant Node_Id := Component_Clause (C1_Ent);
5337 CC2 : constant Node_Id := Component_Clause (C2_Ent);
5340 if Present (CC1) and then Present (CC2) then
5342 -- Exclude odd case where we have two tag fields in the same
5343 -- record, both at location zero. This seems a bit strange, but
5344 -- it seems to happen in some circumstances, perhaps on an error.
5346 if Chars (C1_Ent) = Name_uTag
5348 Chars (C2_Ent) = Name_uTag
5353 -- Here we check if the two fields overlap
5356 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
5357 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
5358 E1 : constant Uint := S1 + Esize (C1_Ent);
5359 E2 : constant Uint := S2 + Esize (C2_Ent);
5362 if E2 <= S1 or else E1 <= S2 then
5365 Error_Msg_Node_2 := Component_Name (CC2);
5366 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
5367 Error_Msg_Node_1 := Component_Name (CC1);
5369 ("component& overlaps & #", Component_Name (CC1));
5370 Overlap_Detected := True;
5374 end Check_Component_Overlap;
5376 --------------------
5377 -- Find_Component --
5378 --------------------
5380 procedure Find_Component is
5382 procedure Search_Component (R : Entity_Id);
5383 -- Search components of R for a match. If found, Comp is set.
5385 ----------------------
5386 -- Search_Component --
5387 ----------------------
5389 procedure Search_Component (R : Entity_Id) is
5391 Comp := First_Component_Or_Discriminant (R);
5392 while Present (Comp) loop
5394 -- Ignore error of attribute name for component name (we
5395 -- already gave an error message for this, so no need to
5398 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
5401 exit when Chars (Comp) = Chars (Component_Name (CC));
5404 Next_Component_Or_Discriminant (Comp);
5406 end Search_Component;
5408 -- Start of processing for Find_Component
5411 -- Return with Comp set to Empty if we have a pragma
5413 if Nkind (CC) = N_Pragma then
5418 -- Search current record for matching component
5420 Search_Component (Rectype);
5422 -- If not found, maybe component of base type that is absent from
5423 -- statically constrained first subtype.
5426 Search_Component (Base_Type (Rectype));
5429 -- If no component, or the component does not reference the component
5430 -- clause in question, then there was some previous error for which
5431 -- we already gave a message, so just return with Comp Empty.
5434 or else Component_Clause (Comp) /= CC
5438 -- Normal case where we have a component clause
5441 Fbit := Component_Bit_Offset (Comp);
5442 Lbit := Fbit + Esize (Comp) - 1;
5446 -- Start of processing for Check_Record_Representation_Clause
5450 Rectype := Entity (Ident);
5452 if Rectype = Any_Type then
5455 Rectype := Underlying_Type (Rectype);
5458 -- See if we have a fully repped derived tagged type
5461 PS : constant Entity_Id := Parent_Subtype (Rectype);
5464 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
5465 Tagged_Parent := PS;
5467 -- Find maximum bit of any component of the parent type
5469 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
5470 Pcomp := First_Entity (Tagged_Parent);
5471 while Present (Pcomp) loop
5472 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
5473 if Component_Bit_Offset (Pcomp) /= No_Uint
5474 and then Known_Static_Esize (Pcomp)
5479 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
5482 Next_Entity (Pcomp);
5488 -- All done if no component clauses
5490 CC := First (Component_Clauses (N));
5496 -- If a tag is present, then create a component clause that places it
5497 -- at the start of the record (otherwise gigi may place it after other
5498 -- fields that have rep clauses).
5500 Fent := First_Entity (Rectype);
5502 if Nkind (Fent) = N_Defining_Identifier
5503 and then Chars (Fent) = Name_uTag
5505 Set_Component_Bit_Offset (Fent, Uint_0);
5506 Set_Normalized_Position (Fent, Uint_0);
5507 Set_Normalized_First_Bit (Fent, Uint_0);
5508 Set_Normalized_Position_Max (Fent, Uint_0);
5509 Init_Esize (Fent, System_Address_Size);
5511 Set_Component_Clause (Fent,
5512 Make_Component_Clause (Loc,
5514 Make_Identifier (Loc,
5515 Chars => Name_uTag),
5518 Make_Integer_Literal (Loc,
5522 Make_Integer_Literal (Loc,
5526 Make_Integer_Literal (Loc,
5527 UI_From_Int (System_Address_Size))));
5529 Ccount := Ccount + 1;
5532 Max_Bit_So_Far := Uint_Minus_1;
5533 Overlap_Check_Required := False;
5535 -- Process the component clauses
5537 while Present (CC) loop
5540 if Present (Comp) then
5541 Ccount := Ccount + 1;
5543 -- We need a full overlap check if record positions non-monotonic
5545 if Fbit <= Max_Bit_So_Far then
5546 Overlap_Check_Required := True;
5549 Max_Bit_So_Far := Lbit;
5551 -- Check bit position out of range of specified size
5553 if Has_Size_Clause (Rectype)
5554 and then Esize (Rectype) <= Lbit
5557 ("bit number out of range of specified size",
5560 -- Check for overlap with tag field
5563 if Is_Tagged_Type (Rectype)
5564 and then Fbit < System_Address_Size
5567 ("component overlaps tag field of&",
5568 Component_Name (CC), Rectype);
5569 Overlap_Detected := True;
5577 -- Check parent overlap if component might overlap parent field
5579 if Present (Tagged_Parent)
5580 and then Fbit <= Parent_Last_Bit
5582 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
5583 while Present (Pcomp) loop
5584 if not Is_Tag (Pcomp)
5585 and then Chars (Pcomp) /= Name_uParent
5587 Check_Component_Overlap (Comp, Pcomp);
5590 Next_Component_Or_Discriminant (Pcomp);
5598 -- Now that we have processed all the component clauses, check for
5599 -- overlap. We have to leave this till last, since the components can
5600 -- appear in any arbitrary order in the representation clause.
5602 -- We do not need this check if all specified ranges were monotonic,
5603 -- as recorded by Overlap_Check_Required being False at this stage.
5605 -- This first section checks if there are any overlapping entries at
5606 -- all. It does this by sorting all entries and then seeing if there are
5607 -- any overlaps. If there are none, then that is decisive, but if there
5608 -- are overlaps, they may still be OK (they may result from fields in
5609 -- different variants).
5611 if Overlap_Check_Required then
5612 Overlap_Check1 : declare
5614 OC_Fbit : array (0 .. Ccount) of Uint;
5615 -- First-bit values for component clauses, the value is the offset
5616 -- of the first bit of the field from start of record. The zero
5617 -- entry is for use in sorting.
5619 OC_Lbit : array (0 .. Ccount) of Uint;
5620 -- Last-bit values for component clauses, the value is the offset
5621 -- of the last bit of the field from start of record. The zero
5622 -- entry is for use in sorting.
5624 OC_Count : Natural := 0;
5625 -- Count of entries in OC_Fbit and OC_Lbit
5627 function OC_Lt (Op1, Op2 : Natural) return Boolean;
5628 -- Compare routine for Sort
5630 procedure OC_Move (From : Natural; To : Natural);
5631 -- Move routine for Sort
5633 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
5639 function OC_Lt (Op1, Op2 : Natural) return Boolean is
5641 return OC_Fbit (Op1) < OC_Fbit (Op2);
5648 procedure OC_Move (From : Natural; To : Natural) is
5650 OC_Fbit (To) := OC_Fbit (From);
5651 OC_Lbit (To) := OC_Lbit (From);
5654 -- Start of processing for Overlap_Check
5657 CC := First (Component_Clauses (N));
5658 while Present (CC) loop
5660 -- Exclude component clause already marked in error
5662 if not Error_Posted (CC) then
5665 if Present (Comp) then
5666 OC_Count := OC_Count + 1;
5667 OC_Fbit (OC_Count) := Fbit;
5668 OC_Lbit (OC_Count) := Lbit;
5675 Sorting.Sort (OC_Count);
5677 Overlap_Check_Required := False;
5678 for J in 1 .. OC_Count - 1 loop
5679 if OC_Lbit (J) >= OC_Fbit (J + 1) then
5680 Overlap_Check_Required := True;
5687 -- If Overlap_Check_Required is still True, then we have to do the full
5688 -- scale overlap check, since we have at least two fields that do
5689 -- overlap, and we need to know if that is OK since they are in
5690 -- different variant, or whether we have a definite problem.
5692 if Overlap_Check_Required then
5693 Overlap_Check2 : declare
5694 C1_Ent, C2_Ent : Entity_Id;
5695 -- Entities of components being checked for overlap
5698 -- Component_List node whose Component_Items are being checked
5701 -- Component declaration for component being checked
5704 C1_Ent := First_Entity (Base_Type (Rectype));
5706 -- Loop through all components in record. For each component check
5707 -- for overlap with any of the preceding elements on the component
5708 -- list containing the component and also, if the component is in
5709 -- a variant, check against components outside the case structure.
5710 -- This latter test is repeated recursively up the variant tree.
5712 Main_Component_Loop : while Present (C1_Ent) loop
5713 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
5714 goto Continue_Main_Component_Loop;
5717 -- Skip overlap check if entity has no declaration node. This
5718 -- happens with discriminants in constrained derived types.
5719 -- Possibly we are missing some checks as a result, but that
5720 -- does not seem terribly serious.
5722 if No (Declaration_Node (C1_Ent)) then
5723 goto Continue_Main_Component_Loop;
5726 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
5728 -- Loop through component lists that need checking. Check the
5729 -- current component list and all lists in variants above us.
5731 Component_List_Loop : loop
5733 -- If derived type definition, go to full declaration
5734 -- If at outer level, check discriminants if there are any.
5736 if Nkind (Clist) = N_Derived_Type_Definition then
5737 Clist := Parent (Clist);
5740 -- Outer level of record definition, check discriminants
5742 if Nkind_In (Clist, N_Full_Type_Declaration,
5743 N_Private_Type_Declaration)
5745 if Has_Discriminants (Defining_Identifier (Clist)) then
5747 First_Discriminant (Defining_Identifier (Clist));
5748 while Present (C2_Ent) loop
5749 exit when C1_Ent = C2_Ent;
5750 Check_Component_Overlap (C1_Ent, C2_Ent);
5751 Next_Discriminant (C2_Ent);
5755 -- Record extension case
5757 elsif Nkind (Clist) = N_Derived_Type_Definition then
5760 -- Otherwise check one component list
5763 Citem := First (Component_Items (Clist));
5764 while Present (Citem) loop
5765 if Nkind (Citem) = N_Component_Declaration then
5766 C2_Ent := Defining_Identifier (Citem);
5767 exit when C1_Ent = C2_Ent;
5768 Check_Component_Overlap (C1_Ent, C2_Ent);
5775 -- Check for variants above us (the parent of the Clist can
5776 -- be a variant, in which case its parent is a variant part,
5777 -- and the parent of the variant part is a component list
5778 -- whose components must all be checked against the current
5779 -- component for overlap).
5781 if Nkind (Parent (Clist)) = N_Variant then
5782 Clist := Parent (Parent (Parent (Clist)));
5784 -- Check for possible discriminant part in record, this
5785 -- is treated essentially as another level in the
5786 -- recursion. For this case the parent of the component
5787 -- list is the record definition, and its parent is the
5788 -- full type declaration containing the discriminant
5791 elsif Nkind (Parent (Clist)) = N_Record_Definition then
5792 Clist := Parent (Parent ((Clist)));
5794 -- If neither of these two cases, we are at the top of
5798 exit Component_List_Loop;
5800 end loop Component_List_Loop;
5802 <<Continue_Main_Component_Loop>>
5803 Next_Entity (C1_Ent);
5805 end loop Main_Component_Loop;
5809 -- The following circuit deals with warning on record holes (gaps). We
5810 -- skip this check if overlap was detected, since it makes sense for the
5811 -- programmer to fix this illegality before worrying about warnings.
5813 if not Overlap_Detected and Warn_On_Record_Holes then
5814 Record_Hole_Check : declare
5815 Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype));
5816 -- Full declaration of record type
5818 procedure Check_Component_List
5822 -- Check component list CL for holes. The starting bit should be
5823 -- Sbit. which is zero for the main record component list and set
5824 -- appropriately for recursive calls for variants. DS is set to
5825 -- a list of discriminant specifications to be included in the
5826 -- consideration of components. It is No_List if none to consider.
5828 --------------------------
5829 -- Check_Component_List --
5830 --------------------------
5832 procedure Check_Component_List
5840 Compl := Integer (List_Length (Component_Items (CL)));
5842 if DS /= No_List then
5843 Compl := Compl + Integer (List_Length (DS));
5847 Comps : array (Natural range 0 .. Compl) of Entity_Id;
5848 -- Gather components (zero entry is for sort routine)
5850 Ncomps : Natural := 0;
5851 -- Number of entries stored in Comps (starting at Comps (1))
5854 -- One component item or discriminant specification
5857 -- Starting bit for next component
5865 function Lt (Op1, Op2 : Natural) return Boolean;
5866 -- Compare routine for Sort
5868 procedure Move (From : Natural; To : Natural);
5869 -- Move routine for Sort
5871 package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
5877 function Lt (Op1, Op2 : Natural) return Boolean is
5879 return Component_Bit_Offset (Comps (Op1))
5881 Component_Bit_Offset (Comps (Op2));
5888 procedure Move (From : Natural; To : Natural) is
5890 Comps (To) := Comps (From);
5894 -- Gather discriminants into Comp
5896 if DS /= No_List then
5897 Citem := First (DS);
5898 while Present (Citem) loop
5899 if Nkind (Citem) = N_Discriminant_Specification then
5901 Ent : constant Entity_Id :=
5902 Defining_Identifier (Citem);
5904 if Ekind (Ent) = E_Discriminant then
5905 Ncomps := Ncomps + 1;
5906 Comps (Ncomps) := Ent;
5915 -- Gather component entities into Comp
5917 Citem := First (Component_Items (CL));
5918 while Present (Citem) loop
5919 if Nkind (Citem) = N_Component_Declaration then
5920 Ncomps := Ncomps + 1;
5921 Comps (Ncomps) := Defining_Identifier (Citem);
5927 -- Now sort the component entities based on the first bit.
5928 -- Note we already know there are no overlapping components.
5930 Sorting.Sort (Ncomps);
5932 -- Loop through entries checking for holes
5935 for J in 1 .. Ncomps loop
5937 Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
5939 if Error_Msg_Uint_1 > 0 then
5941 ("?^-bit gap before component&",
5942 Component_Name (Component_Clause (CEnt)), CEnt);
5945 Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
5948 -- Process variant parts recursively if present
5950 if Present (Variant_Part (CL)) then
5951 Variant := First (Variants (Variant_Part (CL)));
5952 while Present (Variant) loop
5953 Check_Component_List
5954 (Component_List (Variant), Nbit, No_List);
5959 end Check_Component_List;
5961 -- Start of processing for Record_Hole_Check
5968 if Is_Tagged_Type (Rectype) then
5969 Sbit := UI_From_Int (System_Address_Size);
5974 if Nkind (Decl) = N_Full_Type_Declaration
5975 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
5977 Check_Component_List
5978 (Component_List (Type_Definition (Decl)),
5980 Discriminant_Specifications (Decl));
5983 end Record_Hole_Check;
5986 -- For records that have component clauses for all components, and whose
5987 -- size is less than or equal to 32, we need to know the size in the
5988 -- front end to activate possible packed array processing where the
5989 -- component type is a record.
5991 -- At this stage Hbit + 1 represents the first unused bit from all the
5992 -- component clauses processed, so if the component clauses are
5993 -- complete, then this is the length of the record.
5995 -- For records longer than System.Storage_Unit, and for those where not
5996 -- all components have component clauses, the back end determines the
5997 -- length (it may for example be appropriate to round up the size
5998 -- to some convenient boundary, based on alignment considerations, etc).
6000 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
6002 -- Nothing to do if at least one component has no component clause
6004 Comp := First_Component_Or_Discriminant (Rectype);
6005 while Present (Comp) loop
6006 exit when No (Component_Clause (Comp));
6007 Next_Component_Or_Discriminant (Comp);
6010 -- If we fall out of loop, all components have component clauses
6011 -- and so we can set the size to the maximum value.
6014 Set_RM_Size (Rectype, Hbit + 1);
6017 end Check_Record_Representation_Clause;
6023 procedure Check_Size
6027 Biased : out Boolean)
6029 UT : constant Entity_Id := Underlying_Type (T);
6035 -- Dismiss cases for generic types or types with previous errors
6038 or else UT = Any_Type
6039 or else Is_Generic_Type (UT)
6040 or else Is_Generic_Type (Root_Type (UT))
6044 -- Check case of bit packed array
6046 elsif Is_Array_Type (UT)
6047 and then Known_Static_Component_Size (UT)
6048 and then Is_Bit_Packed_Array (UT)
6056 Asiz := Component_Size (UT);
6057 Indx := First_Index (UT);
6059 Ityp := Etype (Indx);
6061 -- If non-static bound, then we are not in the business of
6062 -- trying to check the length, and indeed an error will be
6063 -- issued elsewhere, since sizes of non-static array types
6064 -- cannot be set implicitly or explicitly.
6066 if not Is_Static_Subtype (Ityp) then
6070 -- Otherwise accumulate next dimension
6072 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
6073 Expr_Value (Type_Low_Bound (Ityp)) +
6077 exit when No (Indx);
6083 Error_Msg_Uint_1 := Asiz;
6085 ("size for& too small, minimum allowed is ^", N, T);
6086 Set_Esize (T, Asiz);
6087 Set_RM_Size (T, Asiz);
6091 -- All other composite types are ignored
6093 elsif Is_Composite_Type (UT) then
6096 -- For fixed-point types, don't check minimum if type is not frozen,
6097 -- since we don't know all the characteristics of the type that can
6098 -- affect the size (e.g. a specified small) till freeze time.
6100 elsif Is_Fixed_Point_Type (UT)
6101 and then not Is_Frozen (UT)
6105 -- Cases for which a minimum check is required
6108 -- Ignore if specified size is correct for the type
6110 if Known_Esize (UT) and then Siz = Esize (UT) then
6114 -- Otherwise get minimum size
6116 M := UI_From_Int (Minimum_Size (UT));
6120 -- Size is less than minimum size, but one possibility remains
6121 -- that we can manage with the new size if we bias the type.
6123 M := UI_From_Int (Minimum_Size (UT, Biased => True));
6126 Error_Msg_Uint_1 := M;
6128 ("size for& too small, minimum allowed is ^", N, T);
6138 -------------------------
6139 -- Get_Alignment_Value --
6140 -------------------------
6142 function Get_Alignment_Value (Expr : Node_Id) return Uint is
6143 Align : constant Uint := Static_Integer (Expr);
6146 if Align = No_Uint then
6149 elsif Align <= 0 then
6150 Error_Msg_N ("alignment value must be positive", Expr);
6154 for J in Int range 0 .. 64 loop
6156 M : constant Uint := Uint_2 ** J;
6159 exit when M = Align;
6163 ("alignment value must be power of 2", Expr);
6171 end Get_Alignment_Value;
6177 procedure Initialize is
6179 Address_Clause_Checks.Init;
6180 Independence_Checks.Init;
6181 Unchecked_Conversions.Init;
6184 -------------------------
6185 -- Is_Operational_Item --
6186 -------------------------
6188 function Is_Operational_Item (N : Node_Id) return Boolean is
6190 if Nkind (N) /= N_Attribute_Definition_Clause then
6194 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
6196 return Id = Attribute_Input
6197 or else Id = Attribute_Output
6198 or else Id = Attribute_Read
6199 or else Id = Attribute_Write
6200 or else Id = Attribute_External_Tag;
6203 end Is_Operational_Item;
6209 function Minimum_Size
6211 Biased : Boolean := False) return Nat
6213 Lo : Uint := No_Uint;
6214 Hi : Uint := No_Uint;
6215 LoR : Ureal := No_Ureal;
6216 HiR : Ureal := No_Ureal;
6217 LoSet : Boolean := False;
6218 HiSet : Boolean := False;
6222 R_Typ : constant Entity_Id := Root_Type (T);
6225 -- If bad type, return 0
6227 if T = Any_Type then
6230 -- For generic types, just return zero. There cannot be any legitimate
6231 -- need to know such a size, but this routine may be called with a
6232 -- generic type as part of normal processing.
6234 elsif Is_Generic_Type (R_Typ)
6235 or else R_Typ = Any_Type
6239 -- Access types. Normally an access type cannot have a size smaller
6240 -- than the size of System.Address. The exception is on VMS, where
6241 -- we have short and long addresses, and it is possible for an access
6242 -- type to have a short address size (and thus be less than the size
6243 -- of System.Address itself). We simply skip the check for VMS, and
6244 -- leave it to the back end to do the check.
6246 elsif Is_Access_Type (T) then
6247 if OpenVMS_On_Target then
6250 return System_Address_Size;
6253 -- Floating-point types
6255 elsif Is_Floating_Point_Type (T) then
6256 return UI_To_Int (Esize (R_Typ));
6260 elsif Is_Discrete_Type (T) then
6262 -- The following loop is looking for the nearest compile time known
6263 -- bounds following the ancestor subtype chain. The idea is to find
6264 -- the most restrictive known bounds information.
6268 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
6273 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
6274 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
6281 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
6282 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
6288 Ancest := Ancestor_Subtype (Ancest);
6291 Ancest := Base_Type (T);
6293 if Is_Generic_Type (Ancest) then
6299 -- Fixed-point types. We can't simply use Expr_Value to get the
6300 -- Corresponding_Integer_Value values of the bounds, since these do not
6301 -- get set till the type is frozen, and this routine can be called
6302 -- before the type is frozen. Similarly the test for bounds being static
6303 -- needs to include the case where we have unanalyzed real literals for
6306 elsif Is_Fixed_Point_Type (T) then
6308 -- The following loop is looking for the nearest compile time known
6309 -- bounds following the ancestor subtype chain. The idea is to find
6310 -- the most restrictive known bounds information.
6314 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
6318 -- Note: In the following two tests for LoSet and HiSet, it may
6319 -- seem redundant to test for N_Real_Literal here since normally
6320 -- one would assume that the test for the value being known at
6321 -- compile time includes this case. However, there is a glitch.
6322 -- If the real literal comes from folding a non-static expression,
6323 -- then we don't consider any non- static expression to be known
6324 -- at compile time if we are in configurable run time mode (needed
6325 -- in some cases to give a clearer definition of what is and what
6326 -- is not accepted). So the test is indeed needed. Without it, we
6327 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
6330 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
6331 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
6333 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
6340 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
6341 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
6343 HiR := Expr_Value_R (Type_High_Bound (Ancest));
6349 Ancest := Ancestor_Subtype (Ancest);
6352 Ancest := Base_Type (T);
6354 if Is_Generic_Type (Ancest) then
6360 Lo := UR_To_Uint (LoR / Small_Value (T));
6361 Hi := UR_To_Uint (HiR / Small_Value (T));
6363 -- No other types allowed
6366 raise Program_Error;
6369 -- Fall through with Hi and Lo set. Deal with biased case
6372 and then not Is_Fixed_Point_Type (T)
6373 and then not (Is_Enumeration_Type (T)
6374 and then Has_Non_Standard_Rep (T)))
6375 or else Has_Biased_Representation (T)
6381 -- Signed case. Note that we consider types like range 1 .. -1 to be
6382 -- signed for the purpose of computing the size, since the bounds have
6383 -- to be accommodated in the base type.
6385 if Lo < 0 or else Hi < 0 then
6389 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
6390 -- Note that we accommodate the case where the bounds cross. This
6391 -- can happen either because of the way the bounds are declared
6392 -- or because of the algorithm in Freeze_Fixed_Point_Type.
6406 -- If both bounds are positive, make sure that both are represen-
6407 -- table in the case where the bounds are crossed. This can happen
6408 -- either because of the way the bounds are declared, or because of
6409 -- the algorithm in Freeze_Fixed_Point_Type.
6415 -- S = size, (can accommodate 0 .. (2**size - 1))
6418 while Hi >= Uint_2 ** S loop
6426 ---------------------------
6427 -- New_Stream_Subprogram --
6428 ---------------------------
6430 procedure New_Stream_Subprogram
6434 Nam : TSS_Name_Type)
6436 Loc : constant Source_Ptr := Sloc (N);
6437 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
6438 Subp_Id : Entity_Id;
6439 Subp_Decl : Node_Id;
6443 Defer_Declaration : constant Boolean :=
6444 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
6445 -- For a tagged type, there is a declaration for each stream attribute
6446 -- at the freeze point, and we must generate only a completion of this
6447 -- declaration. We do the same for private types, because the full view
6448 -- might be tagged. Otherwise we generate a declaration at the point of
6449 -- the attribute definition clause.
6451 function Build_Spec return Node_Id;
6452 -- Used for declaration and renaming declaration, so that this is
6453 -- treated as a renaming_as_body.
6459 function Build_Spec return Node_Id is
6460 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
6463 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
6466 Subp_Id := Make_Defining_Identifier (Loc, Sname);
6468 -- S : access Root_Stream_Type'Class
6470 Formals := New_List (
6471 Make_Parameter_Specification (Loc,
6472 Defining_Identifier =>
6473 Make_Defining_Identifier (Loc, Name_S),
6475 Make_Access_Definition (Loc,
6478 Designated_Type (Etype (F)), Loc))));
6480 if Nam = TSS_Stream_Input then
6481 Spec := Make_Function_Specification (Loc,
6482 Defining_Unit_Name => Subp_Id,
6483 Parameter_Specifications => Formals,
6484 Result_Definition => T_Ref);
6489 Make_Parameter_Specification (Loc,
6490 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
6491 Out_Present => Out_P,
6492 Parameter_Type => T_Ref));
6495 Make_Procedure_Specification (Loc,
6496 Defining_Unit_Name => Subp_Id,
6497 Parameter_Specifications => Formals);
6503 -- Start of processing for New_Stream_Subprogram
6506 F := First_Formal (Subp);
6508 if Ekind (Subp) = E_Procedure then
6509 Etyp := Etype (Next_Formal (F));
6511 Etyp := Etype (Subp);
6514 -- Prepare subprogram declaration and insert it as an action on the
6515 -- clause node. The visibility for this entity is used to test for
6516 -- visibility of the attribute definition clause (in the sense of
6517 -- 8.3(23) as amended by AI-195).
6519 if not Defer_Declaration then
6521 Make_Subprogram_Declaration (Loc,
6522 Specification => Build_Spec);
6524 -- For a tagged type, there is always a visible declaration for each
6525 -- stream TSS (it is a predefined primitive operation), and the
6526 -- completion of this declaration occurs at the freeze point, which is
6527 -- not always visible at places where the attribute definition clause is
6528 -- visible. So, we create a dummy entity here for the purpose of
6529 -- tracking the visibility of the attribute definition clause itself.
6533 Make_Defining_Identifier (Loc,
6534 Chars => New_External_Name (Sname, 'V'));
6536 Make_Object_Declaration (Loc,
6537 Defining_Identifier => Subp_Id,
6538 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
6541 Insert_Action (N, Subp_Decl);
6542 Set_Entity (N, Subp_Id);
6545 Make_Subprogram_Renaming_Declaration (Loc,
6546 Specification => Build_Spec,
6547 Name => New_Reference_To (Subp, Loc));
6549 if Defer_Declaration then
6550 Set_TSS (Base_Type (Ent), Subp_Id);
6552 Insert_Action (N, Subp_Decl);
6553 Copy_TSS (Subp_Id, Base_Type (Ent));
6555 end New_Stream_Subprogram;
6557 ------------------------
6558 -- Rep_Item_Too_Early --
6559 ------------------------
6561 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
6563 -- Cannot apply non-operational rep items to generic types
6565 if Is_Operational_Item (N) then
6569 and then Is_Generic_Type (Root_Type (T))
6571 Error_Msg_N ("representation item not allowed for generic type", N);
6575 -- Otherwise check for incomplete type
6577 if Is_Incomplete_Or_Private_Type (T)
6578 and then No (Underlying_Type (T))
6581 ("representation item must be after full type declaration", N);
6584 -- If the type has incomplete components, a representation clause is
6585 -- illegal but stream attributes and Convention pragmas are correct.
6587 elsif Has_Private_Component (T) then
6588 if Nkind (N) = N_Pragma then
6592 ("representation item must appear after type is fully defined",
6599 end Rep_Item_Too_Early;
6601 -----------------------
6602 -- Rep_Item_Too_Late --
6603 -----------------------
6605 function Rep_Item_Too_Late
6608 FOnly : Boolean := False) return Boolean
6611 Parent_Type : Entity_Id;
6614 -- Output the too late message. Note that this is not considered a
6615 -- serious error, since the effect is simply that we ignore the
6616 -- representation clause in this case.
6622 procedure Too_Late is
6624 Error_Msg_N ("|representation item appears too late!", N);
6627 -- Start of processing for Rep_Item_Too_Late
6630 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
6631 -- types, which may be frozen if they appear in a representation clause
6632 -- for a local type.
6635 and then not From_With_Type (T)
6638 S := First_Subtype (T);
6640 if Present (Freeze_Node (S)) then
6642 ("?no more representation items for }", Freeze_Node (S), S);
6647 -- Check for case of non-tagged derived type whose parent either has
6648 -- primitive operations, or is a by reference type (RM 13.1(10)).
6652 and then Is_Derived_Type (T)
6653 and then not Is_Tagged_Type (T)
6655 Parent_Type := Etype (Base_Type (T));
6657 if Has_Primitive_Operations (Parent_Type) then
6660 ("primitive operations already defined for&!", N, Parent_Type);
6663 elsif Is_By_Reference_Type (Parent_Type) then
6666 ("parent type & is a by reference type!", N, Parent_Type);
6671 -- No error, link item into head of chain of rep items for the entity,
6672 -- but avoid chaining if we have an overloadable entity, and the pragma
6673 -- is one that can apply to multiple overloaded entities.
6675 if Is_Overloadable (T)
6676 and then Nkind (N) = N_Pragma
6679 Pname : constant Name_Id := Pragma_Name (N);
6681 if Pname = Name_Convention or else
6682 Pname = Name_Import or else
6683 Pname = Name_Export or else
6684 Pname = Name_External or else
6685 Pname = Name_Interface
6692 Record_Rep_Item (T, N);
6694 end Rep_Item_Too_Late;
6696 -------------------------
6697 -- Same_Representation --
6698 -------------------------
6700 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
6701 T1 : constant Entity_Id := Underlying_Type (Typ1);
6702 T2 : constant Entity_Id := Underlying_Type (Typ2);
6705 -- A quick check, if base types are the same, then we definitely have
6706 -- the same representation, because the subtype specific representation
6707 -- attributes (Size and Alignment) do not affect representation from
6708 -- the point of view of this test.
6710 if Base_Type (T1) = Base_Type (T2) then
6713 elsif Is_Private_Type (Base_Type (T2))
6714 and then Base_Type (T1) = Full_View (Base_Type (T2))
6719 -- Tagged types never have differing representations
6721 if Is_Tagged_Type (T1) then
6725 -- Representations are definitely different if conventions differ
6727 if Convention (T1) /= Convention (T2) then
6731 -- Representations are different if component alignments differ
6733 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
6735 (Is_Record_Type (T2) or else Is_Array_Type (T2))
6736 and then Component_Alignment (T1) /= Component_Alignment (T2)
6741 -- For arrays, the only real issue is component size. If we know the
6742 -- component size for both arrays, and it is the same, then that's
6743 -- good enough to know we don't have a change of representation.
6745 if Is_Array_Type (T1) then
6746 if Known_Component_Size (T1)
6747 and then Known_Component_Size (T2)
6748 and then Component_Size (T1) = Component_Size (T2)
6754 -- Types definitely have same representation if neither has non-standard
6755 -- representation since default representations are always consistent.
6756 -- If only one has non-standard representation, and the other does not,
6757 -- then we consider that they do not have the same representation. They
6758 -- might, but there is no way of telling early enough.
6760 if Has_Non_Standard_Rep (T1) then
6761 if not Has_Non_Standard_Rep (T2) then
6765 return not Has_Non_Standard_Rep (T2);
6768 -- Here the two types both have non-standard representation, and we need
6769 -- to determine if they have the same non-standard representation.
6771 -- For arrays, we simply need to test if the component sizes are the
6772 -- same. Pragma Pack is reflected in modified component sizes, so this
6773 -- check also deals with pragma Pack.
6775 if Is_Array_Type (T1) then
6776 return Component_Size (T1) = Component_Size (T2);
6778 -- Tagged types always have the same representation, because it is not
6779 -- possible to specify different representations for common fields.
6781 elsif Is_Tagged_Type (T1) then
6784 -- Case of record types
6786 elsif Is_Record_Type (T1) then
6788 -- Packed status must conform
6790 if Is_Packed (T1) /= Is_Packed (T2) then
6793 -- Otherwise we must check components. Typ2 maybe a constrained
6794 -- subtype with fewer components, so we compare the components
6795 -- of the base types.
6798 Record_Case : declare
6799 CD1, CD2 : Entity_Id;
6801 function Same_Rep return Boolean;
6802 -- CD1 and CD2 are either components or discriminants. This
6803 -- function tests whether the two have the same representation
6809 function Same_Rep return Boolean is
6811 if No (Component_Clause (CD1)) then
6812 return No (Component_Clause (CD2));
6816 Present (Component_Clause (CD2))
6818 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
6820 Esize (CD1) = Esize (CD2);
6824 -- Start of processing for Record_Case
6827 if Has_Discriminants (T1) then
6828 CD1 := First_Discriminant (T1);
6829 CD2 := First_Discriminant (T2);
6831 -- The number of discriminants may be different if the
6832 -- derived type has fewer (constrained by values). The
6833 -- invisible discriminants retain the representation of
6834 -- the original, so the discrepancy does not per se
6835 -- indicate a different representation.
6838 and then Present (CD2)
6840 if not Same_Rep then
6843 Next_Discriminant (CD1);
6844 Next_Discriminant (CD2);
6849 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
6850 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
6852 while Present (CD1) loop
6853 if not Same_Rep then
6856 Next_Component (CD1);
6857 Next_Component (CD2);
6865 -- For enumeration types, we must check each literal to see if the
6866 -- representation is the same. Note that we do not permit enumeration
6867 -- representation clauses for Character and Wide_Character, so these
6868 -- cases were already dealt with.
6870 elsif Is_Enumeration_Type (T1) then
6871 Enumeration_Case : declare
6875 L1 := First_Literal (T1);
6876 L2 := First_Literal (T2);
6878 while Present (L1) loop
6879 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
6889 end Enumeration_Case;
6891 -- Any other types have the same representation for these purposes
6896 end Same_Representation;
6902 procedure Set_Biased
6906 Biased : Boolean := True)
6910 Set_Has_Biased_Representation (E);
6912 if Warn_On_Biased_Representation then
6914 ("?" & Msg & " forces biased representation for&", N, E);
6919 --------------------
6920 -- Set_Enum_Esize --
6921 --------------------
6923 procedure Set_Enum_Esize (T : Entity_Id) is
6931 -- Find the minimum standard size (8,16,32,64) that fits
6933 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
6934 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
6937 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
6938 Sz := Standard_Character_Size; -- May be > 8 on some targets
6940 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
6943 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
6946 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
6951 if Hi < Uint_2**08 then
6952 Sz := Standard_Character_Size; -- May be > 8 on some targets
6954 elsif Hi < Uint_2**16 then
6957 elsif Hi < Uint_2**32 then
6960 else pragma Assert (Hi < Uint_2**63);
6965 -- That minimum is the proper size unless we have a foreign convention
6966 -- and the size required is 32 or less, in which case we bump the size
6967 -- up to 32. This is required for C and C++ and seems reasonable for
6968 -- all other foreign conventions.
6970 if Has_Foreign_Convention (T)
6971 and then Esize (T) < Standard_Integer_Size
6973 Init_Esize (T, Standard_Integer_Size);
6979 ------------------------------
6980 -- Validate_Address_Clauses --
6981 ------------------------------
6983 procedure Validate_Address_Clauses is
6985 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
6987 ACCR : Address_Clause_Check_Record
6988 renames Address_Clause_Checks.Table (J);
6999 -- Skip processing of this entry if warning already posted
7001 if not Address_Warning_Posted (ACCR.N) then
7003 Expr := Original_Node (Expression (ACCR.N));
7007 X_Alignment := Alignment (ACCR.X);
7008 Y_Alignment := Alignment (ACCR.Y);
7010 -- Similarly obtain sizes
7012 X_Size := Esize (ACCR.X);
7013 Y_Size := Esize (ACCR.Y);
7015 -- Check for large object overlaying smaller one
7018 and then X_Size > Uint_0
7019 and then X_Size > Y_Size
7022 ("?& overlays smaller object", ACCR.N, ACCR.X);
7024 ("\?program execution may be erroneous", ACCR.N);
7025 Error_Msg_Uint_1 := X_Size;
7027 ("\?size of & is ^", ACCR.N, ACCR.X);
7028 Error_Msg_Uint_1 := Y_Size;
7030 ("\?size of & is ^", ACCR.N, ACCR.Y);
7032 -- Check for inadequate alignment, both of the base object
7033 -- and of the offset, if any.
7035 -- Note: we do not check the alignment if we gave a size
7036 -- warning, since it would likely be redundant.
7038 elsif Y_Alignment /= Uint_0
7039 and then (Y_Alignment < X_Alignment
7042 Nkind (Expr) = N_Attribute_Reference
7044 Attribute_Name (Expr) = Name_Address
7046 Has_Compatible_Alignment
7047 (ACCR.X, Prefix (Expr))
7048 /= Known_Compatible))
7051 ("?specified address for& may be inconsistent "
7055 ("\?program execution may be erroneous (RM 13.3(27))",
7057 Error_Msg_Uint_1 := X_Alignment;
7059 ("\?alignment of & is ^",
7061 Error_Msg_Uint_1 := Y_Alignment;
7063 ("\?alignment of & is ^",
7065 if Y_Alignment >= X_Alignment then
7067 ("\?but offset is not multiple of alignment",
7074 end Validate_Address_Clauses;
7076 ---------------------------
7077 -- Validate_Independence --
7078 ---------------------------
7080 procedure Validate_Independence is
7081 SU : constant Uint := UI_From_Int (System_Storage_Unit);
7089 procedure Check_Array_Type (Atyp : Entity_Id);
7090 -- Checks if the array type Atyp has independent components, and
7091 -- if not, outputs an appropriate set of error messages.
7093 procedure No_Independence;
7094 -- Output message that independence cannot be guaranteed
7096 function OK_Component (C : Entity_Id) return Boolean;
7097 -- Checks one component to see if it is independently accessible, and
7098 -- if so yields True, otherwise yields False if independent access
7099 -- cannot be guaranteed. This is a conservative routine, it only
7100 -- returns True if it knows for sure, it returns False if it knows
7101 -- there is a problem, or it cannot be sure there is no problem.
7103 procedure Reason_Bad_Component (C : Entity_Id);
7104 -- Outputs continuation message if a reason can be determined for
7105 -- the component C being bad.
7107 ----------------------
7108 -- Check_Array_Type --
7109 ----------------------
7111 procedure Check_Array_Type (Atyp : Entity_Id) is
7112 Ctyp : constant Entity_Id := Component_Type (Atyp);
7115 -- OK if no alignment clause, no pack, and no component size
7117 if not Has_Component_Size_Clause (Atyp)
7118 and then not Has_Alignment_Clause (Atyp)
7119 and then not Is_Packed (Atyp)
7124 -- Check actual component size
7126 if not Known_Component_Size (Atyp)
7127 or else not (Addressable (Component_Size (Atyp))
7128 and then Component_Size (Atyp) < 64)
7129 or else Component_Size (Atyp) mod Esize (Ctyp) /= 0
7133 -- Bad component size, check reason
7135 if Has_Component_Size_Clause (Atyp) then
7137 Get_Attribute_Definition_Clause
7138 (Atyp, Attribute_Component_Size);
7141 Error_Msg_Sloc := Sloc (P);
7142 Error_Msg_N ("\because of Component_Size clause#", N);
7147 if Is_Packed (Atyp) then
7148 P := Get_Rep_Pragma (Atyp, Name_Pack);
7151 Error_Msg_Sloc := Sloc (P);
7152 Error_Msg_N ("\because of pragma Pack#", N);
7157 -- No reason found, just return
7162 -- Array type is OK independence-wise
7165 end Check_Array_Type;
7167 ---------------------
7168 -- No_Independence --
7169 ---------------------
7171 procedure No_Independence is
7173 if Pragma_Name (N) = Name_Independent then
7175 ("independence cannot be guaranteed for&", N, E);
7178 ("independent components cannot be guaranteed for&", N, E);
7180 end No_Independence;
7186 function OK_Component (C : Entity_Id) return Boolean is
7187 Rec : constant Entity_Id := Scope (C);
7188 Ctyp : constant Entity_Id := Etype (C);
7191 -- OK if no component clause, no Pack, and no alignment clause
7193 if No (Component_Clause (C))
7194 and then not Is_Packed (Rec)
7195 and then not Has_Alignment_Clause (Rec)
7200 -- Here we look at the actual component layout. A component is
7201 -- addressable if its size is a multiple of the Esize of the
7202 -- component type, and its starting position in the record has
7203 -- appropriate alignment, and the record itself has appropriate
7204 -- alignment to guarantee the component alignment.
7206 -- Make sure sizes are static, always assume the worst for any
7207 -- cases where we cannot check static values.
7209 if not (Known_Static_Esize (C)
7210 and then Known_Static_Esize (Ctyp))
7215 -- Size of component must be addressable or greater than 64 bits
7216 -- and a multiple of bytes.
7218 if not Addressable (Esize (C))
7219 and then Esize (C) < Uint_64
7224 -- Check size is proper multiple
7226 if Esize (C) mod Esize (Ctyp) /= 0 then
7230 -- Check alignment of component is OK
7232 if not Known_Component_Bit_Offset (C)
7233 or else Component_Bit_Offset (C) < Uint_0
7234 or else Component_Bit_Offset (C) mod Esize (Ctyp) /= 0
7239 -- Check alignment of record type is OK
7241 if not Known_Alignment (Rec)
7242 or else (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
7247 -- All tests passed, component is addressable
7252 --------------------------
7253 -- Reason_Bad_Component --
7254 --------------------------
7256 procedure Reason_Bad_Component (C : Entity_Id) is
7257 Rec : constant Entity_Id := Scope (C);
7258 Ctyp : constant Entity_Id := Etype (C);
7261 -- If component clause present assume that's the problem
7263 if Present (Component_Clause (C)) then
7264 Error_Msg_Sloc := Sloc (Component_Clause (C));
7265 Error_Msg_N ("\because of Component_Clause#", N);
7269 -- If pragma Pack clause present, assume that's the problem
7271 if Is_Packed (Rec) then
7272 P := Get_Rep_Pragma (Rec, Name_Pack);
7275 Error_Msg_Sloc := Sloc (P);
7276 Error_Msg_N ("\because of pragma Pack#", N);
7281 -- See if record has bad alignment clause
7283 if Has_Alignment_Clause (Rec)
7284 and then Known_Alignment (Rec)
7285 and then (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
7287 P := Get_Attribute_Definition_Clause (Rec, Attribute_Alignment);
7290 Error_Msg_Sloc := Sloc (P);
7291 Error_Msg_N ("\because of Alignment clause#", N);
7295 -- Couldn't find a reason, so return without a message
7298 end Reason_Bad_Component;
7300 -- Start of processing for Validate_Independence
7303 for J in Independence_Checks.First .. Independence_Checks.Last loop
7304 N := Independence_Checks.Table (J).N;
7305 E := Independence_Checks.Table (J).E;
7306 IC := Pragma_Name (N) = Name_Independent_Components;
7308 -- Deal with component case
7310 if Ekind (E) = E_Discriminant or else Ekind (E) = E_Component then
7311 if not OK_Component (E) then
7313 Reason_Bad_Component (E);
7318 -- Deal with record with Independent_Components
7320 if IC and then Is_Record_Type (E) then
7321 Comp := First_Component_Or_Discriminant (E);
7322 while Present (Comp) loop
7323 if not OK_Component (Comp) then
7325 Reason_Bad_Component (Comp);
7329 Next_Component_Or_Discriminant (Comp);
7333 -- Deal with address clause case
7335 if Is_Object (E) then
7336 Addr := Address_Clause (E);
7338 if Present (Addr) then
7340 Error_Msg_Sloc := Sloc (Addr);
7341 Error_Msg_N ("\because of Address clause#", N);
7346 -- Deal with independent components for array type
7348 if IC and then Is_Array_Type (E) then
7349 Check_Array_Type (E);
7352 -- Deal with independent components for array object
7354 if IC and then Is_Object (E) and then Is_Array_Type (Etype (E)) then
7355 Check_Array_Type (Etype (E));
7360 end Validate_Independence;
7362 -----------------------------------
7363 -- Validate_Unchecked_Conversion --
7364 -----------------------------------
7366 procedure Validate_Unchecked_Conversion
7368 Act_Unit : Entity_Id)
7375 -- Obtain source and target types. Note that we call Ancestor_Subtype
7376 -- here because the processing for generic instantiation always makes
7377 -- subtypes, and we want the original frozen actual types.
7379 -- If we are dealing with private types, then do the check on their
7380 -- fully declared counterparts if the full declarations have been
7381 -- encountered (they don't have to be visible, but they must exist!)
7383 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
7385 if Is_Private_Type (Source)
7386 and then Present (Underlying_Type (Source))
7388 Source := Underlying_Type (Source);
7391 Target := Ancestor_Subtype (Etype (Act_Unit));
7393 -- If either type is generic, the instantiation happens within a generic
7394 -- unit, and there is nothing to check. The proper check
7395 -- will happen when the enclosing generic is instantiated.
7397 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
7401 if Is_Private_Type (Target)
7402 and then Present (Underlying_Type (Target))
7404 Target := Underlying_Type (Target);
7407 -- Source may be unconstrained array, but not target
7409 if Is_Array_Type (Target)
7410 and then not Is_Constrained (Target)
7413 ("unchecked conversion to unconstrained array not allowed", N);
7417 -- Warn if conversion between two different convention pointers
7419 if Is_Access_Type (Target)
7420 and then Is_Access_Type (Source)
7421 and then Convention (Target) /= Convention (Source)
7422 and then Warn_On_Unchecked_Conversion
7424 -- Give warnings for subprogram pointers only on most targets. The
7425 -- exception is VMS, where data pointers can have different lengths
7426 -- depending on the pointer convention.
7428 if Is_Access_Subprogram_Type (Target)
7429 or else Is_Access_Subprogram_Type (Source)
7430 or else OpenVMS_On_Target
7433 ("?conversion between pointers with different conventions!", N);
7437 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
7438 -- warning when compiling GNAT-related sources.
7440 if Warn_On_Unchecked_Conversion
7441 and then not In_Predefined_Unit (N)
7442 and then RTU_Loaded (Ada_Calendar)
7444 (Chars (Source) = Name_Time
7446 Chars (Target) = Name_Time)
7448 -- If Ada.Calendar is loaded and the name of one of the operands is
7449 -- Time, there is a good chance that this is Ada.Calendar.Time.
7452 Calendar_Time : constant Entity_Id :=
7453 Full_View (RTE (RO_CA_Time));
7455 pragma Assert (Present (Calendar_Time));
7457 if Source = Calendar_Time
7458 or else Target = Calendar_Time
7461 ("?representation of 'Time values may change between " &
7462 "'G'N'A'T versions", N);
7467 -- Make entry in unchecked conversion table for later processing by
7468 -- Validate_Unchecked_Conversions, which will check sizes and alignments
7469 -- (using values set by the back-end where possible). This is only done
7470 -- if the appropriate warning is active.
7472 if Warn_On_Unchecked_Conversion then
7473 Unchecked_Conversions.Append
7474 (New_Val => UC_Entry'
7479 -- If both sizes are known statically now, then back end annotation
7480 -- is not required to do a proper check but if either size is not
7481 -- known statically, then we need the annotation.
7483 if Known_Static_RM_Size (Source)
7484 and then Known_Static_RM_Size (Target)
7488 Back_Annotate_Rep_Info := True;
7492 -- If unchecked conversion to access type, and access type is declared
7493 -- in the same unit as the unchecked conversion, then set the
7494 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
7497 if Is_Access_Type (Target) and then
7498 In_Same_Source_Unit (Target, N)
7500 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
7503 -- Generate N_Validate_Unchecked_Conversion node for back end in
7504 -- case the back end needs to perform special validation checks.
7506 -- Shouldn't this be in Exp_Ch13, since the check only gets done
7507 -- if we have full expansion and the back end is called ???
7510 Make_Validate_Unchecked_Conversion (Sloc (N));
7511 Set_Source_Type (Vnode, Source);
7512 Set_Target_Type (Vnode, Target);
7514 -- If the unchecked conversion node is in a list, just insert before it.
7515 -- If not we have some strange case, not worth bothering about.
7517 if Is_List_Member (N) then
7518 Insert_After (N, Vnode);
7520 end Validate_Unchecked_Conversion;
7522 ------------------------------------
7523 -- Validate_Unchecked_Conversions --
7524 ------------------------------------
7526 procedure Validate_Unchecked_Conversions is
7528 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
7530 T : UC_Entry renames Unchecked_Conversions.Table (N);
7532 Eloc : constant Source_Ptr := T.Eloc;
7533 Source : constant Entity_Id := T.Source;
7534 Target : constant Entity_Id := T.Target;
7540 -- This validation check, which warns if we have unequal sizes for
7541 -- unchecked conversion, and thus potentially implementation
7542 -- dependent semantics, is one of the few occasions on which we
7543 -- use the official RM size instead of Esize. See description in
7544 -- Einfo "Handling of Type'Size Values" for details.
7546 if Serious_Errors_Detected = 0
7547 and then Known_Static_RM_Size (Source)
7548 and then Known_Static_RM_Size (Target)
7550 -- Don't do the check if warnings off for either type, note the
7551 -- deliberate use of OR here instead of OR ELSE to get the flag
7552 -- Warnings_Off_Used set for both types if appropriate.
7554 and then not (Has_Warnings_Off (Source)
7556 Has_Warnings_Off (Target))
7558 Source_Siz := RM_Size (Source);
7559 Target_Siz := RM_Size (Target);
7561 if Source_Siz /= Target_Siz then
7563 ("?types for unchecked conversion have different sizes!",
7566 if All_Errors_Mode then
7567 Error_Msg_Name_1 := Chars (Source);
7568 Error_Msg_Uint_1 := Source_Siz;
7569 Error_Msg_Name_2 := Chars (Target);
7570 Error_Msg_Uint_2 := Target_Siz;
7571 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
7573 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
7575 if Is_Discrete_Type (Source)
7576 and then Is_Discrete_Type (Target)
7578 if Source_Siz > Target_Siz then
7580 ("\?^ high order bits of source will be ignored!",
7583 elsif Is_Unsigned_Type (Source) then
7585 ("\?source will be extended with ^ high order " &
7586 "zero bits?!", Eloc);
7590 ("\?source will be extended with ^ high order " &
7595 elsif Source_Siz < Target_Siz then
7596 if Is_Discrete_Type (Target) then
7597 if Bytes_Big_Endian then
7599 ("\?target value will include ^ undefined " &
7604 ("\?target value will include ^ undefined " &
7611 ("\?^ trailing bits of target value will be " &
7612 "undefined!", Eloc);
7615 else pragma Assert (Source_Siz > Target_Siz);
7617 ("\?^ trailing bits of source will be ignored!",
7624 -- If both types are access types, we need to check the alignment.
7625 -- If the alignment of both is specified, we can do it here.
7627 if Serious_Errors_Detected = 0
7628 and then Ekind (Source) in Access_Kind
7629 and then Ekind (Target) in Access_Kind
7630 and then Target_Strict_Alignment
7631 and then Present (Designated_Type (Source))
7632 and then Present (Designated_Type (Target))
7635 D_Source : constant Entity_Id := Designated_Type (Source);
7636 D_Target : constant Entity_Id := Designated_Type (Target);
7639 if Known_Alignment (D_Source)
7640 and then Known_Alignment (D_Target)
7643 Source_Align : constant Uint := Alignment (D_Source);
7644 Target_Align : constant Uint := Alignment (D_Target);
7647 if Source_Align < Target_Align
7648 and then not Is_Tagged_Type (D_Source)
7650 -- Suppress warning if warnings suppressed on either
7651 -- type or either designated type. Note the use of
7652 -- OR here instead of OR ELSE. That is intentional,
7653 -- we would like to set flag Warnings_Off_Used in
7654 -- all types for which warnings are suppressed.
7656 and then not (Has_Warnings_Off (D_Source)
7658 Has_Warnings_Off (D_Target)
7660 Has_Warnings_Off (Source)
7662 Has_Warnings_Off (Target))
7664 Error_Msg_Uint_1 := Target_Align;
7665 Error_Msg_Uint_2 := Source_Align;
7666 Error_Msg_Node_1 := D_Target;
7667 Error_Msg_Node_2 := D_Source;
7669 ("?alignment of & (^) is stricter than " &
7670 "alignment of & (^)!", Eloc);
7672 ("\?resulting access value may have invalid " &
7673 "alignment!", Eloc);
7681 end Validate_Unchecked_Conversions;
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