1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, 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_Ch6; use Sem_Ch6;
48 with Sem_Ch8; use Sem_Ch8;
49 with Sem_Eval; use Sem_Eval;
50 with Sem_Res; use Sem_Res;
51 with Sem_Type; use Sem_Type;
52 with Sem_Util; use Sem_Util;
53 with Sem_Warn; use Sem_Warn;
54 with Sinput; use Sinput;
55 with Snames; use Snames;
56 with Stand; use Stand;
57 with Sinfo; use Sinfo;
58 with Stringt; use Stringt;
59 with Targparm; use Targparm;
60 with Ttypes; use Ttypes;
61 with Tbuild; use Tbuild;
62 with Urealp; use Urealp;
63 with Warnsw; use Warnsw;
65 with GNAT.Heap_Sort_G;
67 package body Sem_Ch13 is
69 SSU : constant Pos := System_Storage_Unit;
70 -- Convenient short hand for commonly used constant
72 -----------------------
73 -- Local Subprograms --
74 -----------------------
76 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
77 -- This routine is called after setting the Esize of type entity Typ.
78 -- The purpose is to deal with the situation where an alignment has been
79 -- inherited from a derived type that is no longer appropriate for the
80 -- new Esize value. In this case, we reset the Alignment to unknown.
82 procedure Build_Predicate_Function (Typ : Entity_Id; N : Node_Id);
83 -- If Typ has predicates (indicated by Has_Predicates being set for Typ,
84 -- then either there are pragma Invariant entries on the rep chain for the
85 -- type (note that Predicate aspects are converted to pragma Predicate), or
86 -- there are inherited aspects from a parent type, or ancestor subtypes.
87 -- This procedure builds the spec and body for the Predicate function that
88 -- tests these predicates. N is the freeze node for the type. The spec of
89 -- the function is inserted before the freeze node, and the body of the
90 -- function is inserted after the freeze node.
92 procedure Build_Static_Predicate
96 -- Given a predicated type Typ, where Typ is a discrete static subtype,
97 -- whose predicate expression is Expr, tests if Expr is a static predicate,
98 -- and if so, builds the predicate range list. Nam is the name of the one
99 -- argument to the predicate function. Occurrences of the type name in the
100 -- predicate expression have been replaced by identifier references to this
101 -- name, which is unique, so any identifier with Chars matching Nam must be
102 -- a reference to the type. If the predicate is non-static, this procedure
103 -- returns doing nothing. If the predicate is static, then the predicate
104 -- list is stored in Static_Predicate (Typ), and the Expr is rewritten as
105 -- a canonicalized membership operation.
107 function Get_Alignment_Value (Expr : Node_Id) return Uint;
108 -- Given the expression for an alignment value, returns the corresponding
109 -- Uint value. If the value is inappropriate, then error messages are
110 -- posted as required, and a value of No_Uint is returned.
112 function Is_Operational_Item (N : Node_Id) return Boolean;
113 -- A specification for a stream attribute is allowed before the full type
114 -- is declared, as explained in AI-00137 and the corrigendum. Attributes
115 -- that do not specify a representation characteristic are operational
118 procedure New_Stream_Subprogram
122 Nam : TSS_Name_Type);
123 -- Create a subprogram renaming of a given stream attribute to the
124 -- designated subprogram and then in the tagged case, provide this as a
125 -- primitive operation, or in the non-tagged case make an appropriate TSS
126 -- entry. This is more properly an expansion activity than just semantics,
127 -- but the presence of user-defined stream functions for limited types is a
128 -- legality check, which is why this takes place here rather than in
129 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
130 -- function to be generated.
132 -- To avoid elaboration anomalies with freeze nodes, for untagged types
133 -- we generate both a subprogram declaration and a subprogram renaming
134 -- declaration, so that the attribute specification is handled as a
135 -- renaming_as_body. For tagged types, the specification is one of the
139 with procedure Replace_Type_Reference (N : Node_Id);
140 procedure Replace_Type_References_Generic (N : Node_Id; TName : Name_Id);
141 -- This is used to scan an expression for a predicate or invariant aspect
142 -- replacing occurrences of the name TName (the name of the subtype to
143 -- which the aspect applies) with appropriate references to the parameter
144 -- of the predicate function or invariant procedure. The procedure passed
145 -- as a generic parameter does the actual replacement of node N, which is
146 -- either a simple direct reference to TName, or a selected component that
147 -- represents an appropriately qualified occurrence of TName.
153 Biased : Boolean := True);
154 -- If Biased is True, sets Has_Biased_Representation flag for E, and
155 -- outputs a warning message at node N if Warn_On_Biased_Representation is
156 -- is True. This warning inserts the string Msg to describe the construct
159 ----------------------------------------------
160 -- Table for Validate_Unchecked_Conversions --
161 ----------------------------------------------
163 -- The following table collects unchecked conversions for validation.
164 -- Entries are made by Validate_Unchecked_Conversion and then the
165 -- call to Validate_Unchecked_Conversions does the actual error
166 -- checking and posting of warnings. The reason for this delayed
167 -- processing is to take advantage of back-annotations of size and
168 -- alignment values performed by the back end.
170 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
171 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
172 -- will already have modified all Sloc values if the -gnatD option is set.
174 type UC_Entry is record
175 Eloc : Source_Ptr; -- node used for posting warnings
176 Source : Entity_Id; -- source type for unchecked conversion
177 Target : Entity_Id; -- target type for unchecked conversion
180 package Unchecked_Conversions is new Table.Table (
181 Table_Component_Type => UC_Entry,
182 Table_Index_Type => Int,
183 Table_Low_Bound => 1,
185 Table_Increment => 200,
186 Table_Name => "Unchecked_Conversions");
188 ----------------------------------------
189 -- Table for Validate_Address_Clauses --
190 ----------------------------------------
192 -- If an address clause has the form
194 -- for X'Address use Expr
196 -- where Expr is of the form Y'Address or recursively is a reference
197 -- to a constant of either of these forms, and X and Y are entities of
198 -- objects, then if Y has a smaller alignment than X, that merits a
199 -- warning about possible bad alignment. The following table collects
200 -- address clauses of this kind. We put these in a table so that they
201 -- can be checked after the back end has completed annotation of the
202 -- alignments of objects, since we can catch more cases that way.
204 type Address_Clause_Check_Record is record
206 -- The address clause
209 -- The entity of the object overlaying Y
212 -- The entity of the object being overlaid
215 -- Whether the address is offset within Y
218 package Address_Clause_Checks is new Table.Table (
219 Table_Component_Type => Address_Clause_Check_Record,
220 Table_Index_Type => Int,
221 Table_Low_Bound => 1,
223 Table_Increment => 200,
224 Table_Name => "Address_Clause_Checks");
226 -----------------------------------------
227 -- Adjust_Record_For_Reverse_Bit_Order --
228 -----------------------------------------
230 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
235 -- Processing depends on version of Ada
237 -- For Ada 95, we just renumber bits within a storage unit. We do the
238 -- same for Ada 83 mode, since we recognize pragma Bit_Order in Ada 83,
239 -- and are free to add this extension.
241 if Ada_Version < Ada_2005 then
242 Comp := First_Component_Or_Discriminant (R);
243 while Present (Comp) loop
244 CC := Component_Clause (Comp);
246 -- If component clause is present, then deal with the non-default
247 -- bit order case for Ada 95 mode.
249 -- We only do this processing for the base type, and in fact that
250 -- is important, since otherwise if there are record subtypes, we
251 -- could reverse the bits once for each subtype, which is wrong.
254 and then Ekind (R) = E_Record_Type
257 CFB : constant Uint := Component_Bit_Offset (Comp);
258 CSZ : constant Uint := Esize (Comp);
259 CLC : constant Node_Id := Component_Clause (Comp);
260 Pos : constant Node_Id := Position (CLC);
261 FB : constant Node_Id := First_Bit (CLC);
263 Storage_Unit_Offset : constant Uint :=
264 CFB / System_Storage_Unit;
266 Start_Bit : constant Uint :=
267 CFB mod System_Storage_Unit;
270 -- Cases where field goes over storage unit boundary
272 if Start_Bit + CSZ > System_Storage_Unit then
274 -- Allow multi-byte field but generate warning
276 if Start_Bit mod System_Storage_Unit = 0
277 and then CSZ mod System_Storage_Unit = 0
280 ("multi-byte field specified with non-standard"
281 & " Bit_Order?", CLC);
283 if Bytes_Big_Endian then
285 ("bytes are not reversed "
286 & "(component is big-endian)?", CLC);
289 ("bytes are not reversed "
290 & "(component is little-endian)?", CLC);
293 -- Do not allow non-contiguous field
297 ("attempt to specify non-contiguous field "
298 & "not permitted", CLC);
300 ("\caused by non-standard Bit_Order "
303 ("\consider possibility of using "
304 & "Ada 2005 mode here", CLC);
307 -- Case where field fits in one storage unit
310 -- Give warning if suspicious component clause
312 if Intval (FB) >= System_Storage_Unit
313 and then Warn_On_Reverse_Bit_Order
316 ("?Bit_Order clause does not affect " &
317 "byte ordering", Pos);
319 Intval (Pos) + Intval (FB) /
322 ("?position normalized to ^ before bit " &
323 "order interpreted", Pos);
326 -- Here is where we fix up the Component_Bit_Offset value
327 -- to account for the reverse bit order. Some examples of
328 -- what needs to be done are:
330 -- First_Bit .. Last_Bit Component_Bit_Offset
342 -- The rule is that the first bit is is obtained by
343 -- subtracting the old ending bit from storage_unit - 1.
345 Set_Component_Bit_Offset
347 (Storage_Unit_Offset * System_Storage_Unit) +
348 (System_Storage_Unit - 1) -
349 (Start_Bit + CSZ - 1));
351 Set_Normalized_First_Bit
353 Component_Bit_Offset (Comp) mod
354 System_Storage_Unit);
359 Next_Component_Or_Discriminant (Comp);
362 -- For Ada 2005, we do machine scalar processing, as fully described In
363 -- AI-133. This involves gathering all components which start at the
364 -- same byte offset and processing them together. Same approach is still
365 -- valid in later versions including Ada 2012.
369 Max_Machine_Scalar_Size : constant Uint :=
371 (Standard_Long_Long_Integer_Size);
372 -- We use this as the maximum machine scalar size
375 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
378 -- This first loop through components does two things. First it
379 -- deals with the case of components with component clauses whose
380 -- length is greater than the maximum machine scalar size (either
381 -- accepting them or rejecting as needed). Second, it counts the
382 -- number of components with component clauses whose length does
383 -- not exceed this maximum for later processing.
386 Comp := First_Component_Or_Discriminant (R);
387 while Present (Comp) loop
388 CC := Component_Clause (Comp);
392 Fbit : constant Uint :=
393 Static_Integer (First_Bit (CC));
394 Lbit : constant Uint :=
395 Static_Integer (Last_Bit (CC));
398 -- Case of component with last bit >= max machine scalar
400 if Lbit >= Max_Machine_Scalar_Size then
402 -- This is allowed only if first bit is zero, and
403 -- last bit + 1 is a multiple of storage unit size.
405 if Fbit = 0 and then (Lbit + 1) mod SSU = 0 then
407 -- This is the case to give a warning if enabled
409 if Warn_On_Reverse_Bit_Order then
411 ("multi-byte field specified with "
412 & " non-standard Bit_Order?", CC);
414 if Bytes_Big_Endian then
416 ("\bytes are not reversed "
417 & "(component is big-endian)?", CC);
420 ("\bytes are not reversed "
421 & "(component is little-endian)?", CC);
425 -- Give error message for RM 13.4.1(10) violation
429 ("machine scalar rules not followed for&",
430 First_Bit (CC), Comp);
432 Error_Msg_Uint_1 := Lbit;
433 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
435 ("\last bit (^) exceeds maximum machine "
439 if (Lbit + 1) mod SSU /= 0 then
440 Error_Msg_Uint_1 := SSU;
442 ("\and is not a multiple of Storage_Unit (^) "
447 Error_Msg_Uint_1 := Fbit;
449 ("\and first bit (^) is non-zero "
455 -- OK case of machine scalar related component clause,
456 -- For now, just count them.
459 Num_CC := Num_CC + 1;
464 Next_Component_Or_Discriminant (Comp);
467 -- We need to sort the component clauses on the basis of the
468 -- Position values in the clause, so we can group clauses with
469 -- the same Position. together to determine the relevant machine
473 Comps : array (0 .. Num_CC) of Entity_Id;
474 -- Array to collect component and discriminant entities. The
475 -- data starts at index 1, the 0'th entry is for the sort
478 function CP_Lt (Op1, Op2 : Natural) return Boolean;
479 -- Compare routine for Sort
481 procedure CP_Move (From : Natural; To : Natural);
482 -- Move routine for Sort
484 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
488 -- Start and stop positions in the component list of the set of
489 -- components with the same starting position (that constitute
490 -- components in a single machine scalar).
493 -- Maximum last bit value of any component in this set
496 -- Corresponding machine scalar size
502 function CP_Lt (Op1, Op2 : Natural) return Boolean is
504 return Position (Component_Clause (Comps (Op1))) <
505 Position (Component_Clause (Comps (Op2)));
512 procedure CP_Move (From : Natural; To : Natural) is
514 Comps (To) := Comps (From);
517 -- Start of processing for Sort_CC
520 -- Collect the machine scalar relevant component clauses
523 Comp := First_Component_Or_Discriminant (R);
524 while Present (Comp) loop
526 CC : constant Node_Id := Component_Clause (Comp);
529 -- Collect only component clauses whose last bit is less
530 -- than machine scalar size. Any component clause whose
531 -- last bit exceeds this value does not take part in
532 -- machine scalar layout considerations. The test for
533 -- Error_Posted makes sure we exclude component clauses
534 -- for which we already posted an error.
537 and then not Error_Posted (Last_Bit (CC))
538 and then Static_Integer (Last_Bit (CC)) <
539 Max_Machine_Scalar_Size
541 Num_CC := Num_CC + 1;
542 Comps (Num_CC) := Comp;
546 Next_Component_Or_Discriminant (Comp);
549 -- Sort by ascending position number
551 Sorting.Sort (Num_CC);
553 -- We now have all the components whose size does not exceed
554 -- the max machine scalar value, sorted by starting position.
555 -- In this loop we gather groups of clauses starting at the
556 -- same position, to process them in accordance with AI-133.
559 while Stop < Num_CC loop
564 (Last_Bit (Component_Clause (Comps (Start))));
565 while Stop < Num_CC loop
567 (Position (Component_Clause (Comps (Stop + 1)))) =
569 (Position (Component_Clause (Comps (Stop))))
577 (Component_Clause (Comps (Stop)))));
583 -- Now we have a group of component clauses from Start to
584 -- Stop whose positions are identical, and MaxL is the
585 -- maximum last bit value of any of these components.
587 -- We need to determine the corresponding machine scalar
588 -- size. This loop assumes that machine scalar sizes are
589 -- even, and that each possible machine scalar has twice
590 -- as many bits as the next smaller one.
592 MSS := Max_Machine_Scalar_Size;
594 and then (MSS / 2) >= SSU
595 and then (MSS / 2) > MaxL
600 -- Here is where we fix up the Component_Bit_Offset value
601 -- to account for the reverse bit order. Some examples of
602 -- what needs to be done for the case of a machine scalar
605 -- First_Bit .. Last_Bit Component_Bit_Offset
617 -- The rule is that the first bit is obtained by subtracting
618 -- the old ending bit from machine scalar size - 1.
620 for C in Start .. Stop loop
622 Comp : constant Entity_Id := Comps (C);
623 CC : constant Node_Id :=
624 Component_Clause (Comp);
625 LB : constant Uint :=
626 Static_Integer (Last_Bit (CC));
627 NFB : constant Uint := MSS - Uint_1 - LB;
628 NLB : constant Uint := NFB + Esize (Comp) - 1;
629 Pos : constant Uint :=
630 Static_Integer (Position (CC));
633 if Warn_On_Reverse_Bit_Order then
634 Error_Msg_Uint_1 := MSS;
636 ("info: reverse bit order in machine " &
637 "scalar of length^?", First_Bit (CC));
638 Error_Msg_Uint_1 := NFB;
639 Error_Msg_Uint_2 := NLB;
641 if Bytes_Big_Endian then
643 ("?\info: big-endian range for "
644 & "component & is ^ .. ^",
645 First_Bit (CC), Comp);
648 ("?\info: little-endian range "
649 & "for component & is ^ .. ^",
650 First_Bit (CC), Comp);
654 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
655 Set_Normalized_First_Bit (Comp, NFB mod SSU);
662 end Adjust_Record_For_Reverse_Bit_Order;
664 --------------------------------------
665 -- Alignment_Check_For_Esize_Change --
666 --------------------------------------
668 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
670 -- If the alignment is known, and not set by a rep clause, and is
671 -- inconsistent with the size being set, then reset it to unknown,
672 -- we assume in this case that the size overrides the inherited
673 -- alignment, and that the alignment must be recomputed.
675 if Known_Alignment (Typ)
676 and then not Has_Alignment_Clause (Typ)
677 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
679 Init_Alignment (Typ);
681 end Alignment_Check_For_Esize_Change;
683 -----------------------------------
684 -- Analyze_Aspect_Specifications --
685 -----------------------------------
687 procedure Analyze_Aspect_Specifications (N : Node_Id; E : Entity_Id) is
692 L : constant List_Id := Aspect_Specifications (N);
694 Ins_Node : Node_Id := N;
695 -- Insert pragmas (except Pre/Post/Invariant/Predicate) after this node
697 -- The general processing involves building an attribute definition
698 -- clause or a pragma node that corresponds to the aspect. Then one
699 -- of two things happens:
701 -- If we are required to delay the evaluation of this aspect to the
702 -- freeze point, we attach the corresponding pragma/attribute definition
703 -- clause to the aspect specification node, which is then placed in the
704 -- Rep Item chain. In this case we mark the entity by setting the flag
705 -- Has_Delayed_Aspects and we evaluate the rep item at the freeze point.
707 -- If no delay is required, we just insert the pragma or attribute
708 -- after the declaration, and it will get processed by the normal
709 -- circuit. The From_Aspect_Specification flag is set on the pragma
710 -- or attribute definition node in either case to activate special
711 -- processing (e.g. not traversing the list of homonyms for inline).
713 Delay_Required : Boolean;
714 -- Set True if delay is required
717 pragma Assert (Present (L));
719 -- Loop through aspects
722 Aspect_Loop : while Present (Aspect) loop
724 Loc : constant Source_Ptr := Sloc (Aspect);
725 Id : constant Node_Id := Identifier (Aspect);
726 Expr : constant Node_Id := Expression (Aspect);
727 Nam : constant Name_Id := Chars (Id);
728 A_Id : constant Aspect_Id := Get_Aspect_Id (Nam);
731 Eloc : Source_Ptr := Sloc (Expr);
732 -- Source location of expression, modified when we split PPC's
734 procedure Check_False_Aspect_For_Derived_Type;
735 -- This procedure checks for the case of a false aspect for a
736 -- derived type, which improperly tries to cancel an aspect
737 -- inherited from the parent;
739 -----------------------------------------
740 -- Check_False_Aspect_For_Derived_Type --
741 -----------------------------------------
743 procedure Check_False_Aspect_For_Derived_Type is
745 -- We are only checking derived types
747 if not Is_Derived_Type (E) then
752 when Aspect_Atomic | Aspect_Shared =>
753 if not Is_Atomic (E) then
757 when Aspect_Atomic_Components =>
758 if not Has_Atomic_Components (E) then
762 when Aspect_Discard_Names =>
763 if not Discard_Names (E) then
768 if not Is_Packed (E) then
772 when Aspect_Unchecked_Union =>
773 if not Is_Unchecked_Union (E) then
777 when Aspect_Volatile =>
778 if not Is_Volatile (E) then
782 when Aspect_Volatile_Components =>
783 if not Has_Volatile_Components (E) then
791 -- Fall through means we are canceling an inherited aspect
793 Error_Msg_Name_1 := Nam;
795 ("derived type& inherits aspect%, cannot cancel", Expr, E);
796 end Check_False_Aspect_For_Derived_Type;
798 -- Start of processing for Aspect_Loop
801 -- Skip aspect if already analyzed (not clear if this is needed)
803 if Analyzed (Aspect) then
807 Set_Analyzed (Aspect);
808 Set_Entity (Aspect, E);
809 Ent := New_Occurrence_Of (E, Sloc (Id));
811 -- Check for duplicate aspect. Note that the Comes_From_Source
812 -- test allows duplicate Pre/Post's that we generate internally
813 -- to escape being flagged here.
816 while Anod /= Aspect loop
817 if Same_Aspect (A_Id, Get_Aspect_Id (Chars (Identifier (Anod))))
818 and then Comes_From_Source (Aspect)
820 Error_Msg_Name_1 := Nam;
821 Error_Msg_Sloc := Sloc (Anod);
823 -- Case of same aspect specified twice
825 if Class_Present (Anod) = Class_Present (Aspect) then
826 if not Class_Present (Anod) then
828 ("aspect% for & previously given#",
832 ("aspect `%''Class` for & previously given#",
836 -- Case of Pre and Pre'Class both specified
838 elsif Nam = Name_Pre then
839 if Class_Present (Aspect) then
841 ("aspect `Pre''Class` for & is not allowed here",
844 ("\since aspect `Pre` previously given#",
849 ("aspect `Pre` for & is not allowed here",
852 ("\since aspect `Pre''Class` previously given#",
857 -- Allowed case of X and X'Class both specified
863 -- Copy expression for later processing by the procedures
864 -- Check_Aspect_At_[Freeze_Point | End_Of_Declarations]
866 Set_Entity (Id, New_Copy_Tree (Expr));
868 -- Processing based on specific aspect
872 -- No_Aspect should be impossible
877 -- Aspects taking an optional boolean argument. For all of
878 -- these we just create a matching pragma and insert it, if
879 -- the expression is missing or set to True. If the expression
880 -- is False, we can ignore the aspect with the exception that
881 -- in the case of a derived type, we must check for an illegal
882 -- attempt to cancel an inherited aspect.
884 when Boolean_Aspects =>
885 Set_Is_Boolean_Aspect (Aspect);
888 and then Is_False (Static_Boolean (Expr))
890 Check_False_Aspect_For_Derived_Type;
894 -- If True, build corresponding pragma node
898 Pragma_Argument_Associations => New_List (Ent),
900 Make_Identifier (Sloc (Id), Chars (Id)));
902 -- Never need to delay for boolean aspects
904 Delay_Required := False;
906 -- Library unit aspects. These are boolean aspects, but we
907 -- have to do special things with the insertion, since the
908 -- pragma belongs inside the declarations of a package.
910 when Library_Unit_Aspects =>
912 and then Is_False (Static_Boolean (Expr))
917 -- Build corresponding pragma node
921 Pragma_Argument_Associations => New_List (Ent),
923 Make_Identifier (Sloc (Id), Chars (Id)));
925 -- This requires special handling in the case of a package
926 -- declaration, the pragma needs to be inserted in the list
927 -- of declarations for the associated package. There is no
928 -- issue of visibility delay for these aspects.
930 if Nkind (N) = N_Package_Declaration then
931 if Nkind (Parent (N)) /= N_Compilation_Unit then
933 ("incorrect context for library unit aspect&", Id);
936 (Aitem, Visible_Declarations (Specification (N)));
942 -- If not package declaration, no delay is required
944 Delay_Required := False;
946 -- Aspects corresponding to attribute definition clauses
948 when Aspect_Address |
951 Aspect_Component_Size |
952 Aspect_External_Tag |
954 Aspect_Machine_Radix |
959 Aspect_Storage_Pool |
960 Aspect_Storage_Size |
965 -- Construct the attribute definition clause
968 Make_Attribute_Definition_Clause (Loc,
971 Expression => Relocate_Node (Expr));
973 -- A delay is required except in the common case where
974 -- the expression is a literal, in which case it is fine
975 -- to take care of it right away.
977 if Nkind_In (Expr, N_Integer_Literal, N_String_Literal) then
978 Delay_Required := False;
980 Delay_Required := True;
981 Set_Is_Delayed_Aspect (Aspect);
984 -- Aspects corresponding to pragmas with two arguments, where
985 -- the first argument is a local name referring to the entity,
986 -- and the second argument is the aspect definition expression
987 -- which is an expression that does not get analyzed.
989 when Aspect_Suppress |
992 -- Construct the pragma
996 Pragma_Argument_Associations => New_List (
997 New_Occurrence_Of (E, Loc),
998 Relocate_Node (Expr)),
1000 Make_Identifier (Sloc (Id), Chars (Id)));
1002 -- We don't have to play the delay game here, since the only
1003 -- values are check names which don't get analyzed anyway.
1005 Delay_Required := False;
1007 -- Aspects corresponding to pragmas with two arguments, where
1008 -- the second argument is a local name referring to the entity,
1009 -- and the first argument is the aspect definition expression.
1011 when Aspect_Warnings =>
1013 -- Construct the pragma
1017 Pragma_Argument_Associations => New_List (
1018 Relocate_Node (Expr),
1019 New_Occurrence_Of (E, Loc)),
1020 Pragma_Identifier =>
1021 Make_Identifier (Sloc (Id), Chars (Id)),
1022 Class_Present => Class_Present (Aspect));
1024 -- We don't have to play the delay game here, since the only
1025 -- values are ON/OFF which don't get analyzed anyway.
1027 Delay_Required := False;
1029 -- Default_Value and Default_Component_Value aspects. These
1030 -- are specially handled because they have no corresponding
1031 -- pragmas or attributes.
1033 when Aspect_Default_Value | Aspect_Default_Component_Value =>
1034 Error_Msg_Name_1 := Chars (Id);
1036 if not Is_Type (E) then
1037 Error_Msg_N ("aspect% can only apply to a type", Id);
1040 elsif not Is_First_Subtype (E) then
1041 Error_Msg_N ("aspect% cannot apply to subtype", Id);
1044 elsif A_Id = Aspect_Default_Value
1045 and then not Is_Scalar_Type (E)
1048 ("aspect% can only be applied to scalar type", Id);
1051 elsif A_Id = Aspect_Default_Component_Value then
1052 if not Is_Array_Type (E) then
1054 ("aspect% can only be applied to array type", Id);
1056 elsif not Is_Scalar_Type (Component_Type (E)) then
1058 ("aspect% requires scalar components", Id);
1064 Delay_Required := True;
1065 Set_Is_Delayed_Aspect (Aspect);
1066 Set_Has_Default_Aspect (Base_Type (Entity (Ent)));
1068 -- Aspects Pre/Post generate Precondition/Postcondition pragmas
1069 -- with a first argument that is the expression, and a second
1070 -- argument that is an informative message if the test fails.
1071 -- This is inserted right after the declaration, to get the
1072 -- required pragma placement. The processing for the pragmas
1073 -- takes care of the required delay.
1075 when Pre_Post_Aspects => declare
1079 if A_Id = Aspect_Pre or else A_Id = Aspect_Precondition then
1080 Pname := Name_Precondition;
1082 Pname := Name_Postcondition;
1085 -- If the expressions is of the form A and then B, then
1086 -- we generate separate Pre/Post aspects for the separate
1087 -- clauses. Since we allow multiple pragmas, there is no
1088 -- problem in allowing multiple Pre/Post aspects internally.
1090 -- We do not do this for Pre'Class, since we have to put
1091 -- these conditions together in a complex OR expression
1093 if Pname = Name_Postcondition
1094 or else not Class_Present (Aspect)
1096 while Nkind (Expr) = N_And_Then loop
1097 Insert_After (Aspect,
1098 Make_Aspect_Specification (Sloc (Right_Opnd (Expr)),
1099 Identifier => Identifier (Aspect),
1100 Expression => Relocate_Node (Right_Opnd (Expr)),
1101 Class_Present => Class_Present (Aspect),
1102 Split_PPC => True));
1103 Rewrite (Expr, Relocate_Node (Left_Opnd (Expr)));
1104 Eloc := Sloc (Expr);
1108 -- Build the precondition/postcondition pragma
1112 Pragma_Identifier =>
1113 Make_Identifier (Sloc (Id), Pname),
1114 Class_Present => Class_Present (Aspect),
1115 Split_PPC => Split_PPC (Aspect),
1116 Pragma_Argument_Associations => New_List (
1117 Make_Pragma_Argument_Association (Eloc,
1118 Chars => Name_Check,
1119 Expression => Relocate_Node (Expr))));
1121 -- Add message unless exception messages are suppressed
1123 if not Opt.Exception_Locations_Suppressed then
1124 Append_To (Pragma_Argument_Associations (Aitem),
1125 Make_Pragma_Argument_Association (Eloc,
1126 Chars => Name_Message,
1128 Make_String_Literal (Eloc,
1130 & Get_Name_String (Pname)
1132 & Build_Location_String (Eloc))));
1135 Set_From_Aspect_Specification (Aitem, True);
1136 Set_Is_Delayed_Aspect (Aspect);
1138 -- For Pre/Post cases, insert immediately after the entity
1139 -- declaration, since that is the required pragma placement.
1140 -- Note that for these aspects, we do not have to worry
1141 -- about delay issues, since the pragmas themselves deal
1142 -- with delay of visibility for the expression analysis.
1144 -- If the entity is a library-level subprogram, the pre/
1145 -- postconditions must be treated as late pragmas.
1147 if Nkind (Parent (N)) = N_Compilation_Unit then
1148 Add_Global_Declaration (Aitem);
1150 Insert_After (N, Aitem);
1156 -- Invariant aspects generate a corresponding pragma with a
1157 -- first argument that is the entity, a second argument that is
1158 -- the expression and a third argument that is an appropriate
1159 -- message. This is inserted right after the declaration, to
1160 -- get the required pragma placement. The pragma processing
1161 -- takes care of the required delay.
1163 when Aspect_Invariant |
1164 Aspect_Type_Invariant =>
1166 -- Check placement legality
1168 if not Nkind_In (N, N_Private_Type_Declaration,
1169 N_Private_Extension_Declaration)
1172 ("invariant aspect must apply to a private type", N);
1175 -- Construct the pragma
1179 Pragma_Argument_Associations =>
1180 New_List (Ent, Relocate_Node (Expr)),
1181 Class_Present => Class_Present (Aspect),
1182 Pragma_Identifier =>
1183 Make_Identifier (Sloc (Id), Name_Invariant));
1185 -- Add message unless exception messages are suppressed
1187 if not Opt.Exception_Locations_Suppressed then
1188 Append_To (Pragma_Argument_Associations (Aitem),
1189 Make_Pragma_Argument_Association (Eloc,
1190 Chars => Name_Message,
1192 Make_String_Literal (Eloc,
1193 Strval => "failed invariant from "
1194 & Build_Location_String (Eloc))));
1197 Set_From_Aspect_Specification (Aitem, True);
1198 Set_Is_Delayed_Aspect (Aspect);
1200 -- For Invariant case, insert immediately after the entity
1201 -- declaration. We do not have to worry about delay issues
1202 -- since the pragma processing takes care of this.
1204 Insert_After (N, Aitem);
1207 -- Predicate aspects generate a corresponding pragma with a
1208 -- first argument that is the entity, and the second argument
1209 -- is the expression.
1211 when Aspect_Dynamic_Predicate |
1213 Aspect_Static_Predicate =>
1215 -- Construct the pragma (always a pragma Predicate, with
1216 -- flags recording whether
1220 Pragma_Argument_Associations =>
1221 New_List (Ent, Relocate_Node (Expr)),
1222 Class_Present => Class_Present (Aspect),
1223 Pragma_Identifier =>
1224 Make_Identifier (Sloc (Id), Name_Predicate));
1226 Set_From_Aspect_Specification (Aitem, True);
1228 -- Set special flags for dynamic/static cases
1230 if A_Id = Aspect_Dynamic_Predicate then
1231 Set_From_Dynamic_Predicate (Aitem);
1232 elsif A_Id = Aspect_Static_Predicate then
1233 Set_From_Static_Predicate (Aitem);
1236 -- Make sure we have a freeze node (it might otherwise be
1237 -- missing in cases like subtype X is Y, and we would not
1238 -- have a place to build the predicate function).
1240 Set_Has_Predicates (E);
1242 if Is_Private_Type (E)
1243 and then Present (Full_View (E))
1245 Set_Has_Predicates (Full_View (E));
1246 Set_Has_Delayed_Aspects (Full_View (E));
1249 Ensure_Freeze_Node (E);
1250 Set_Is_Delayed_Aspect (Aspect);
1251 Delay_Required := True;
1254 -- If a delay is required, we delay the freeze (not much point in
1255 -- delaying the aspect if we don't delay the freeze!). The pragma
1256 -- or attribute clause if there is one is then attached to the
1257 -- aspect specification which is placed in the rep item list.
1259 if Delay_Required then
1260 if Present (Aitem) then
1261 Set_From_Aspect_Specification (Aitem, True);
1262 Set_Is_Delayed_Aspect (Aitem);
1263 Set_Aspect_Rep_Item (Aspect, Aitem);
1266 Ensure_Freeze_Node (E);
1267 Set_Has_Delayed_Aspects (E);
1268 Record_Rep_Item (E, Aspect);
1270 -- If no delay required, insert the pragma/clause in the tree
1273 Set_From_Aspect_Specification (Aitem, True);
1275 -- If this is a compilation unit, we will put the pragma in
1276 -- the Pragmas_After list of the N_Compilation_Unit_Aux node.
1278 if Nkind (Parent (Ins_Node)) = N_Compilation_Unit then
1280 Aux : constant Node_Id :=
1281 Aux_Decls_Node (Parent (Ins_Node));
1284 pragma Assert (Nkind (Aux) = N_Compilation_Unit_Aux);
1286 if No (Pragmas_After (Aux)) then
1287 Set_Pragmas_After (Aux, Empty_List);
1290 -- For Pre_Post put at start of list, otherwise at end
1292 if A_Id in Pre_Post_Aspects then
1293 Prepend (Aitem, Pragmas_After (Aux));
1295 Append (Aitem, Pragmas_After (Aux));
1299 -- Here if not compilation unit case
1302 -- For Pre/Post cases, insert immediately after the entity
1303 -- declaration, since that is the required pragma placement.
1305 if A_Id in Pre_Post_Aspects then
1306 Insert_After (N, Aitem);
1308 -- For all other cases, insert in sequence
1311 Insert_After (Ins_Node, Aitem);
1320 end loop Aspect_Loop;
1321 end Analyze_Aspect_Specifications;
1323 -----------------------
1324 -- Analyze_At_Clause --
1325 -----------------------
1327 -- An at clause is replaced by the corresponding Address attribute
1328 -- definition clause that is the preferred approach in Ada 95.
1330 procedure Analyze_At_Clause (N : Node_Id) is
1331 CS : constant Boolean := Comes_From_Source (N);
1334 -- This is an obsolescent feature
1336 Check_Restriction (No_Obsolescent_Features, N);
1338 if Warn_On_Obsolescent_Feature then
1340 ("at clause is an obsolescent feature (RM J.7(2))?", N);
1342 ("\use address attribute definition clause instead?", N);
1345 -- Rewrite as address clause
1348 Make_Attribute_Definition_Clause (Sloc (N),
1349 Name => Identifier (N),
1350 Chars => Name_Address,
1351 Expression => Expression (N)));
1353 -- We preserve Comes_From_Source, since logically the clause still
1354 -- comes from the source program even though it is changed in form.
1356 Set_Comes_From_Source (N, CS);
1358 -- Analyze rewritten clause
1360 Analyze_Attribute_Definition_Clause (N);
1361 end Analyze_At_Clause;
1363 -----------------------------------------
1364 -- Analyze_Attribute_Definition_Clause --
1365 -----------------------------------------
1367 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
1368 Loc : constant Source_Ptr := Sloc (N);
1369 Nam : constant Node_Id := Name (N);
1370 Attr : constant Name_Id := Chars (N);
1371 Expr : constant Node_Id := Expression (N);
1372 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
1375 -- The entity of Nam after it is analyzed. In the case of an incomplete
1376 -- type, this is the underlying type.
1379 -- The underlying entity to which the attribute applies. Generally this
1380 -- is the Underlying_Type of Ent, except in the case where the clause
1381 -- applies to full view of incomplete type or private type in which case
1382 -- U_Ent is just a copy of Ent.
1384 FOnly : Boolean := False;
1385 -- Reset to True for subtype specific attribute (Alignment, Size)
1386 -- and for stream attributes, i.e. those cases where in the call
1387 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
1388 -- rules are checked. Note that the case of stream attributes is not
1389 -- clear from the RM, but see AI95-00137. Also, the RM seems to
1390 -- disallow Storage_Size for derived task types, but that is also
1391 -- clearly unintentional.
1393 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
1394 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
1395 -- definition clauses.
1397 function Duplicate_Clause return Boolean;
1398 -- This routine checks if the aspect for U_Ent being given by attribute
1399 -- definition clause N is for an aspect that has already been specified,
1400 -- and if so gives an error message. If there is a duplicate, True is
1401 -- returned, otherwise if there is no error, False is returned.
1403 -----------------------------------
1404 -- Analyze_Stream_TSS_Definition --
1405 -----------------------------------
1407 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
1408 Subp : Entity_Id := Empty;
1413 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
1414 -- True for Read attribute, false for other attributes
1416 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
1417 -- Return true if the entity is a subprogram with an appropriate
1418 -- profile for the attribute being defined.
1420 ----------------------
1421 -- Has_Good_Profile --
1422 ----------------------
1424 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
1426 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
1427 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
1428 (False => E_Procedure, True => E_Function);
1432 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
1436 F := First_Formal (Subp);
1439 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
1440 or else Designated_Type (Etype (F)) /=
1441 Class_Wide_Type (RTE (RE_Root_Stream_Type))
1446 if not Is_Function then
1450 Expected_Mode : constant array (Boolean) of Entity_Kind :=
1451 (False => E_In_Parameter,
1452 True => E_Out_Parameter);
1454 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
1462 Typ := Etype (Subp);
1465 return Base_Type (Typ) = Base_Type (Ent)
1466 and then No (Next_Formal (F));
1467 end Has_Good_Profile;
1469 -- Start of processing for Analyze_Stream_TSS_Definition
1474 if not Is_Type (U_Ent) then
1475 Error_Msg_N ("local name must be a subtype", Nam);
1479 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
1481 -- If Pnam is present, it can be either inherited from an ancestor
1482 -- type (in which case it is legal to redefine it for this type), or
1483 -- be a previous definition of the attribute for the same type (in
1484 -- which case it is illegal).
1486 -- In the first case, it will have been analyzed already, and we
1487 -- can check that its profile does not match the expected profile
1488 -- for a stream attribute of U_Ent. In the second case, either Pnam
1489 -- has been analyzed (and has the expected profile), or it has not
1490 -- been analyzed yet (case of a type that has not been frozen yet
1491 -- and for which the stream attribute has been set using Set_TSS).
1494 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
1496 Error_Msg_Sloc := Sloc (Pnam);
1497 Error_Msg_Name_1 := Attr;
1498 Error_Msg_N ("% attribute already defined #", Nam);
1504 if Is_Entity_Name (Expr) then
1505 if not Is_Overloaded (Expr) then
1506 if Has_Good_Profile (Entity (Expr)) then
1507 Subp := Entity (Expr);
1511 Get_First_Interp (Expr, I, It);
1512 while Present (It.Nam) loop
1513 if Has_Good_Profile (It.Nam) then
1518 Get_Next_Interp (I, It);
1523 if Present (Subp) then
1524 if Is_Abstract_Subprogram (Subp) then
1525 Error_Msg_N ("stream subprogram must not be abstract", Expr);
1529 Set_Entity (Expr, Subp);
1530 Set_Etype (Expr, Etype (Subp));
1532 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
1535 Error_Msg_Name_1 := Attr;
1536 Error_Msg_N ("incorrect expression for% attribute", Expr);
1538 end Analyze_Stream_TSS_Definition;
1540 ----------------------
1541 -- Duplicate_Clause --
1542 ----------------------
1544 function Duplicate_Clause return Boolean is
1548 -- Nothing to do if this attribute definition clause comes from
1549 -- an aspect specification, since we could not be duplicating an
1550 -- explicit clause, and we dealt with the case of duplicated aspects
1551 -- in Analyze_Aspect_Specifications.
1553 if From_Aspect_Specification (N) then
1557 -- Otherwise current clause may duplicate previous clause or a
1558 -- previously given aspect specification for the same aspect.
1560 A := Get_Rep_Item_For_Entity (U_Ent, Chars (N));
1563 if Entity (A) = U_Ent then
1564 Error_Msg_Name_1 := Chars (N);
1565 Error_Msg_Sloc := Sloc (A);
1566 Error_Msg_NE ("aspect% for & previously given#", N, U_Ent);
1572 end Duplicate_Clause;
1574 -- Start of processing for Analyze_Attribute_Definition_Clause
1577 -- The following code is a defense against recursion. Not clear that
1578 -- this can happen legitimately, but perhaps some error situations
1579 -- can cause it, and we did see this recursion during testing.
1581 if Analyzed (N) then
1584 Set_Analyzed (N, True);
1587 -- Process Ignore_Rep_Clauses option (we also ignore rep clauses in
1588 -- CodePeer mode, since they are not relevant in that context).
1590 if Ignore_Rep_Clauses or CodePeer_Mode then
1593 -- The following should be ignored. They do not affect legality
1594 -- and may be target dependent. The basic idea of -gnatI is to
1595 -- ignore any rep clauses that may be target dependent but do not
1596 -- affect legality (except possibly to be rejected because they
1597 -- are incompatible with the compilation target).
1599 when Attribute_Alignment |
1600 Attribute_Bit_Order |
1601 Attribute_Component_Size |
1602 Attribute_Machine_Radix |
1603 Attribute_Object_Size |
1605 Attribute_Stream_Size |
1606 Attribute_Value_Size =>
1607 Rewrite (N, Make_Null_Statement (Sloc (N)));
1610 -- We do not want too ignore 'Small in CodePeer_Mode, since it
1611 -- has an impact on the exact computations performed.
1613 -- Perhaps 'Small should also not be ignored by
1614 -- Ignore_Rep_Clauses ???
1616 when Attribute_Small =>
1617 if Ignore_Rep_Clauses then
1618 Rewrite (N, Make_Null_Statement (Sloc (N)));
1622 -- The following should not be ignored, because in the first place
1623 -- they are reasonably portable, and should not cause problems in
1624 -- compiling code from another target, and also they do affect
1625 -- legality, e.g. failing to provide a stream attribute for a
1626 -- type may make a program illegal.
1628 when Attribute_External_Tag |
1632 Attribute_Storage_Pool |
1633 Attribute_Storage_Size |
1637 -- Other cases are errors ("attribute& cannot be set with
1638 -- definition clause"), which will be caught below.
1646 Ent := Entity (Nam);
1648 if Rep_Item_Too_Early (Ent, N) then
1652 -- Rep clause applies to full view of incomplete type or private type if
1653 -- we have one (if not, this is a premature use of the type). However,
1654 -- certain semantic checks need to be done on the specified entity (i.e.
1655 -- the private view), so we save it in Ent.
1657 if Is_Private_Type (Ent)
1658 and then Is_Derived_Type (Ent)
1659 and then not Is_Tagged_Type (Ent)
1660 and then No (Full_View (Ent))
1662 -- If this is a private type whose completion is a derivation from
1663 -- another private type, there is no full view, and the attribute
1664 -- belongs to the type itself, not its underlying parent.
1668 elsif Ekind (Ent) = E_Incomplete_Type then
1670 -- The attribute applies to the full view, set the entity of the
1671 -- attribute definition accordingly.
1673 Ent := Underlying_Type (Ent);
1675 Set_Entity (Nam, Ent);
1678 U_Ent := Underlying_Type (Ent);
1681 -- Complete other routine error checks
1683 if Etype (Nam) = Any_Type then
1686 elsif Scope (Ent) /= Current_Scope then
1687 Error_Msg_N ("entity must be declared in this scope", Nam);
1690 elsif No (U_Ent) then
1693 elsif Is_Type (U_Ent)
1694 and then not Is_First_Subtype (U_Ent)
1695 and then Id /= Attribute_Object_Size
1696 and then Id /= Attribute_Value_Size
1697 and then not From_At_Mod (N)
1699 Error_Msg_N ("cannot specify attribute for subtype", Nam);
1703 Set_Entity (N, U_Ent);
1705 -- Switch on particular attribute
1713 -- Address attribute definition clause
1715 when Attribute_Address => Address : begin
1717 -- A little error check, catch for X'Address use X'Address;
1719 if Nkind (Nam) = N_Identifier
1720 and then Nkind (Expr) = N_Attribute_Reference
1721 and then Attribute_Name (Expr) = Name_Address
1722 and then Nkind (Prefix (Expr)) = N_Identifier
1723 and then Chars (Nam) = Chars (Prefix (Expr))
1726 ("address for & is self-referencing", Prefix (Expr), Ent);
1730 -- Not that special case, carry on with analysis of expression
1732 Analyze_And_Resolve (Expr, RTE (RE_Address));
1734 -- Even when ignoring rep clauses we need to indicate that the
1735 -- entity has an address clause and thus it is legal to declare
1738 if Ignore_Rep_Clauses then
1739 if Ekind_In (U_Ent, E_Variable, E_Constant) then
1740 Record_Rep_Item (U_Ent, N);
1746 if Duplicate_Clause then
1749 -- Case of address clause for subprogram
1751 elsif Is_Subprogram (U_Ent) then
1752 if Has_Homonym (U_Ent) then
1754 ("address clause cannot be given " &
1755 "for overloaded subprogram",
1760 -- For subprograms, all address clauses are permitted, and we
1761 -- mark the subprogram as having a deferred freeze so that Gigi
1762 -- will not elaborate it too soon.
1764 -- Above needs more comments, what is too soon about???
1766 Set_Has_Delayed_Freeze (U_Ent);
1768 -- Case of address clause for entry
1770 elsif Ekind (U_Ent) = E_Entry then
1771 if Nkind (Parent (N)) = N_Task_Body then
1773 ("entry address must be specified in task spec", Nam);
1777 -- For entries, we require a constant address
1779 Check_Constant_Address_Clause (Expr, U_Ent);
1781 -- Special checks for task types
1783 if Is_Task_Type (Scope (U_Ent))
1784 and then Comes_From_Source (Scope (U_Ent))
1787 ("?entry address declared for entry in task type", N);
1789 ("\?only one task can be declared of this type", N);
1792 -- Entry address clauses are obsolescent
1794 Check_Restriction (No_Obsolescent_Features, N);
1796 if Warn_On_Obsolescent_Feature then
1798 ("attaching interrupt to task entry is an " &
1799 "obsolescent feature (RM J.7.1)?", N);
1801 ("\use interrupt procedure instead?", N);
1804 -- Case of an address clause for a controlled object which we
1805 -- consider to be erroneous.
1807 elsif Is_Controlled (Etype (U_Ent))
1808 or else Has_Controlled_Component (Etype (U_Ent))
1811 ("?controlled object& must not be overlaid", Nam, U_Ent);
1813 ("\?Program_Error will be raised at run time", Nam);
1814 Insert_Action (Declaration_Node (U_Ent),
1815 Make_Raise_Program_Error (Loc,
1816 Reason => PE_Overlaid_Controlled_Object));
1819 -- Case of address clause for a (non-controlled) object
1822 Ekind (U_Ent) = E_Variable
1824 Ekind (U_Ent) = E_Constant
1827 Expr : constant Node_Id := Expression (N);
1832 -- Exported variables cannot have an address clause, because
1833 -- this cancels the effect of the pragma Export.
1835 if Is_Exported (U_Ent) then
1837 ("cannot export object with address clause", Nam);
1841 Find_Overlaid_Entity (N, O_Ent, Off);
1843 -- Overlaying controlled objects is erroneous
1846 and then (Has_Controlled_Component (Etype (O_Ent))
1847 or else Is_Controlled (Etype (O_Ent)))
1850 ("?cannot overlay with controlled object", Expr);
1852 ("\?Program_Error will be raised at run time", Expr);
1853 Insert_Action (Declaration_Node (U_Ent),
1854 Make_Raise_Program_Error (Loc,
1855 Reason => PE_Overlaid_Controlled_Object));
1858 elsif Present (O_Ent)
1859 and then Ekind (U_Ent) = E_Constant
1860 and then not Is_Constant_Object (O_Ent)
1862 Error_Msg_N ("constant overlays a variable?", Expr);
1864 elsif Present (Renamed_Object (U_Ent)) then
1866 ("address clause not allowed"
1867 & " for a renaming declaration (RM 13.1(6))", Nam);
1870 -- Imported variables can have an address clause, but then
1871 -- the import is pretty meaningless except to suppress
1872 -- initializations, so we do not need such variables to
1873 -- be statically allocated (and in fact it causes trouble
1874 -- if the address clause is a local value).
1876 elsif Is_Imported (U_Ent) then
1877 Set_Is_Statically_Allocated (U_Ent, False);
1880 -- We mark a possible modification of a variable with an
1881 -- address clause, since it is likely aliasing is occurring.
1883 Note_Possible_Modification (Nam, Sure => False);
1885 -- Here we are checking for explicit overlap of one variable
1886 -- by another, and if we find this then mark the overlapped
1887 -- variable as also being volatile to prevent unwanted
1888 -- optimizations. This is a significant pessimization so
1889 -- avoid it when there is an offset, i.e. when the object
1890 -- is composite; they cannot be optimized easily anyway.
1893 and then Is_Object (O_Ent)
1896 Set_Treat_As_Volatile (O_Ent);
1899 -- Legality checks on the address clause for initialized
1900 -- objects is deferred until the freeze point, because
1901 -- a subsequent pragma might indicate that the object is
1902 -- imported and thus not initialized.
1904 Set_Has_Delayed_Freeze (U_Ent);
1906 -- If an initialization call has been generated for this
1907 -- object, it needs to be deferred to after the freeze node
1908 -- we have just now added, otherwise GIGI will see a
1909 -- reference to the variable (as actual to the IP call)
1910 -- before its definition.
1913 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1915 if Present (Init_Call) then
1917 Append_Freeze_Action (U_Ent, Init_Call);
1921 if Is_Exported (U_Ent) then
1923 ("& cannot be exported if an address clause is given",
1926 ("\define and export a variable " &
1927 "that holds its address instead",
1931 -- Entity has delayed freeze, so we will generate an
1932 -- alignment check at the freeze point unless suppressed.
1934 if not Range_Checks_Suppressed (U_Ent)
1935 and then not Alignment_Checks_Suppressed (U_Ent)
1937 Set_Check_Address_Alignment (N);
1940 -- Kill the size check code, since we are not allocating
1941 -- the variable, it is somewhere else.
1943 Kill_Size_Check_Code (U_Ent);
1945 -- If the address clause is of the form:
1947 -- for Y'Address use X'Address
1951 -- Const : constant Address := X'Address;
1953 -- for Y'Address use Const;
1955 -- then we make an entry in the table for checking the size
1956 -- and alignment of the overlaying variable. We defer this
1957 -- check till after code generation to take full advantage
1958 -- of the annotation done by the back end. This entry is
1959 -- only made if the address clause comes from source.
1961 -- If the entity has a generic type, the check will be
1962 -- performed in the instance if the actual type justifies
1963 -- it, and we do not insert the clause in the table to
1964 -- prevent spurious warnings.
1966 if Address_Clause_Overlay_Warnings
1967 and then Comes_From_Source (N)
1968 and then Present (O_Ent)
1969 and then Is_Object (O_Ent)
1971 if not Is_Generic_Type (Etype (U_Ent)) then
1972 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1975 -- If variable overlays a constant view, and we are
1976 -- warning on overlays, then mark the variable as
1977 -- overlaying a constant (we will give warnings later
1978 -- if this variable is assigned).
1980 if Is_Constant_Object (O_Ent)
1981 and then Ekind (U_Ent) = E_Variable
1983 Set_Overlays_Constant (U_Ent);
1988 -- Not a valid entity for an address clause
1991 Error_Msg_N ("address cannot be given for &", Nam);
1999 -- Alignment attribute definition clause
2001 when Attribute_Alignment => Alignment : declare
2002 Align : constant Uint := Get_Alignment_Value (Expr);
2007 if not Is_Type (U_Ent)
2008 and then Ekind (U_Ent) /= E_Variable
2009 and then Ekind (U_Ent) /= E_Constant
2011 Error_Msg_N ("alignment cannot be given for &", Nam);
2013 elsif Duplicate_Clause then
2016 elsif Align /= No_Uint then
2017 Set_Has_Alignment_Clause (U_Ent);
2018 Set_Alignment (U_Ent, Align);
2020 -- For an array type, U_Ent is the first subtype. In that case,
2021 -- also set the alignment of the anonymous base type so that
2022 -- other subtypes (such as the itypes for aggregates of the
2023 -- type) also receive the expected alignment.
2025 if Is_Array_Type (U_Ent) then
2026 Set_Alignment (Base_Type (U_Ent), Align);
2035 -- Bit_Order attribute definition clause
2037 when Attribute_Bit_Order => Bit_Order : declare
2039 if not Is_Record_Type (U_Ent) then
2041 ("Bit_Order can only be defined for record type", Nam);
2043 elsif Duplicate_Clause then
2047 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
2049 if Etype (Expr) = Any_Type then
2052 elsif not Is_Static_Expression (Expr) then
2053 Flag_Non_Static_Expr
2054 ("Bit_Order requires static expression!", Expr);
2057 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
2058 Set_Reverse_Bit_Order (U_Ent, True);
2064 --------------------
2065 -- Component_Size --
2066 --------------------
2068 -- Component_Size attribute definition clause
2070 when Attribute_Component_Size => Component_Size_Case : declare
2071 Csize : constant Uint := Static_Integer (Expr);
2075 New_Ctyp : Entity_Id;
2079 if not Is_Array_Type (U_Ent) then
2080 Error_Msg_N ("component size requires array type", Nam);
2084 Btype := Base_Type (U_Ent);
2085 Ctyp := Component_Type (Btype);
2087 if Duplicate_Clause then
2090 elsif Rep_Item_Too_Early (Btype, N) then
2093 elsif Csize /= No_Uint then
2094 Check_Size (Expr, Ctyp, Csize, Biased);
2096 -- For the biased case, build a declaration for a subtype that
2097 -- will be used to represent the biased subtype that reflects
2098 -- the biased representation of components. We need the subtype
2099 -- to get proper conversions on referencing elements of the
2100 -- array. Note: component size clauses are ignored in VM mode.
2102 if VM_Target = No_VM then
2105 Make_Defining_Identifier (Loc,
2107 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
2110 Make_Subtype_Declaration (Loc,
2111 Defining_Identifier => New_Ctyp,
2112 Subtype_Indication =>
2113 New_Occurrence_Of (Component_Type (Btype), Loc));
2115 Set_Parent (Decl, N);
2116 Analyze (Decl, Suppress => All_Checks);
2118 Set_Has_Delayed_Freeze (New_Ctyp, False);
2119 Set_Esize (New_Ctyp, Csize);
2120 Set_RM_Size (New_Ctyp, Csize);
2121 Init_Alignment (New_Ctyp);
2122 Set_Is_Itype (New_Ctyp, True);
2123 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
2125 Set_Component_Type (Btype, New_Ctyp);
2126 Set_Biased (New_Ctyp, N, "component size clause");
2129 Set_Component_Size (Btype, Csize);
2131 -- For VM case, we ignore component size clauses
2134 -- Give a warning unless we are in GNAT mode, in which case
2135 -- the warning is suppressed since it is not useful.
2137 if not GNAT_Mode then
2139 ("?component size ignored in this configuration", N);
2143 -- Deal with warning on overridden size
2145 if Warn_On_Overridden_Size
2146 and then Has_Size_Clause (Ctyp)
2147 and then RM_Size (Ctyp) /= Csize
2150 ("?component size overrides size clause for&",
2154 Set_Has_Component_Size_Clause (Btype, True);
2155 Set_Has_Non_Standard_Rep (Btype, True);
2157 end Component_Size_Case;
2163 when Attribute_External_Tag => External_Tag :
2165 if not Is_Tagged_Type (U_Ent) then
2166 Error_Msg_N ("should be a tagged type", Nam);
2169 if Duplicate_Clause then
2173 Analyze_And_Resolve (Expr, Standard_String);
2175 if not Is_Static_Expression (Expr) then
2176 Flag_Non_Static_Expr
2177 ("static string required for tag name!", Nam);
2180 if VM_Target = No_VM then
2181 Set_Has_External_Tag_Rep_Clause (U_Ent);
2183 Error_Msg_Name_1 := Attr;
2185 ("% attribute unsupported in this configuration", Nam);
2188 if not Is_Library_Level_Entity (U_Ent) then
2190 ("?non-unique external tag supplied for &", N, U_Ent);
2192 ("?\same external tag applies to all subprogram calls", N);
2194 ("?\corresponding internal tag cannot be obtained", N);
2203 when Attribute_Input =>
2204 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
2205 Set_Has_Specified_Stream_Input (Ent);
2211 -- Machine radix attribute definition clause
2213 when Attribute_Machine_Radix => Machine_Radix : declare
2214 Radix : constant Uint := Static_Integer (Expr);
2217 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
2218 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
2220 elsif Duplicate_Clause then
2223 elsif Radix /= No_Uint then
2224 Set_Has_Machine_Radix_Clause (U_Ent);
2225 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
2229 elsif Radix = 10 then
2230 Set_Machine_Radix_10 (U_Ent);
2232 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
2241 -- Object_Size attribute definition clause
2243 when Attribute_Object_Size => Object_Size : declare
2244 Size : constant Uint := Static_Integer (Expr);
2247 pragma Warnings (Off, Biased);
2250 if not Is_Type (U_Ent) then
2251 Error_Msg_N ("Object_Size cannot be given for &", Nam);
2253 elsif Duplicate_Clause then
2257 Check_Size (Expr, U_Ent, Size, Biased);
2265 UI_Mod (Size, 64) /= 0
2268 ("Object_Size must be 8, 16, 32, or multiple of 64",
2272 Set_Esize (U_Ent, Size);
2273 Set_Has_Object_Size_Clause (U_Ent);
2274 Alignment_Check_For_Esize_Change (U_Ent);
2282 when Attribute_Output =>
2283 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
2284 Set_Has_Specified_Stream_Output (Ent);
2290 when Attribute_Read =>
2291 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
2292 Set_Has_Specified_Stream_Read (Ent);
2298 -- Size attribute definition clause
2300 when Attribute_Size => Size : declare
2301 Size : constant Uint := Static_Integer (Expr);
2308 if Duplicate_Clause then
2311 elsif not Is_Type (U_Ent)
2312 and then Ekind (U_Ent) /= E_Variable
2313 and then Ekind (U_Ent) /= E_Constant
2315 Error_Msg_N ("size cannot be given for &", Nam);
2317 elsif Is_Array_Type (U_Ent)
2318 and then not Is_Constrained (U_Ent)
2321 ("size cannot be given for unconstrained array", Nam);
2323 elsif Size /= No_Uint then
2324 if VM_Target /= No_VM and then not GNAT_Mode then
2326 -- Size clause is not handled properly on VM targets.
2327 -- Display a warning unless we are in GNAT mode, in which
2328 -- case this is useless.
2331 ("?size clauses are ignored in this configuration", N);
2334 if Is_Type (U_Ent) then
2337 Etyp := Etype (U_Ent);
2340 -- Check size, note that Gigi is in charge of checking that the
2341 -- size of an array or record type is OK. Also we do not check
2342 -- the size in the ordinary fixed-point case, since it is too
2343 -- early to do so (there may be subsequent small clause that
2344 -- affects the size). We can check the size if a small clause
2345 -- has already been given.
2347 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
2348 or else Has_Small_Clause (U_Ent)
2350 Check_Size (Expr, Etyp, Size, Biased);
2351 Set_Biased (U_Ent, N, "size clause", Biased);
2354 -- For types set RM_Size and Esize if possible
2356 if Is_Type (U_Ent) then
2357 Set_RM_Size (U_Ent, Size);
2359 -- For elementary types, increase Object_Size to power of 2,
2360 -- but not less than a storage unit in any case (normally
2361 -- this means it will be byte addressable).
2363 -- For all other types, nothing else to do, we leave Esize
2364 -- (object size) unset, the back end will set it from the
2365 -- size and alignment in an appropriate manner.
2367 if Is_Elementary_Type (U_Ent) then
2368 if Size <= System_Storage_Unit then
2369 Init_Esize (U_Ent, System_Storage_Unit);
2370 elsif Size <= 16 then
2371 Init_Esize (U_Ent, 16);
2372 elsif Size <= 32 then
2373 Init_Esize (U_Ent, 32);
2375 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
2378 Alignment_Check_For_Esize_Change (U_Ent);
2381 -- For objects, set Esize only
2384 if Is_Elementary_Type (Etyp) then
2385 if Size /= System_Storage_Unit
2387 Size /= System_Storage_Unit * 2
2389 Size /= System_Storage_Unit * 4
2391 Size /= System_Storage_Unit * 8
2393 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
2394 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
2396 ("size for primitive object must be a power of 2"
2397 & " in the range ^-^", N);
2401 Set_Esize (U_Ent, Size);
2404 Set_Has_Size_Clause (U_Ent);
2412 -- Small attribute definition clause
2414 when Attribute_Small => Small : declare
2415 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
2419 Analyze_And_Resolve (Expr, Any_Real);
2421 if Etype (Expr) = Any_Type then
2424 elsif not Is_Static_Expression (Expr) then
2425 Flag_Non_Static_Expr
2426 ("small requires static expression!", Expr);
2430 Small := Expr_Value_R (Expr);
2432 if Small <= Ureal_0 then
2433 Error_Msg_N ("small value must be greater than zero", Expr);
2439 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
2441 ("small requires an ordinary fixed point type", Nam);
2443 elsif Has_Small_Clause (U_Ent) then
2444 Error_Msg_N ("small already given for &", Nam);
2446 elsif Small > Delta_Value (U_Ent) then
2448 ("small value must not be greater then delta value", Nam);
2451 Set_Small_Value (U_Ent, Small);
2452 Set_Small_Value (Implicit_Base, Small);
2453 Set_Has_Small_Clause (U_Ent);
2454 Set_Has_Small_Clause (Implicit_Base);
2455 Set_Has_Non_Standard_Rep (Implicit_Base);
2463 -- Storage_Pool attribute definition clause
2465 when Attribute_Storage_Pool => Storage_Pool : declare
2470 if Ekind (U_Ent) = E_Access_Subprogram_Type then
2472 ("storage pool cannot be given for access-to-subprogram type",
2477 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
2480 ("storage pool can only be given for access types", Nam);
2483 elsif Is_Derived_Type (U_Ent) then
2485 ("storage pool cannot be given for a derived access type",
2488 elsif Duplicate_Clause then
2491 elsif Present (Associated_Storage_Pool (U_Ent)) then
2492 Error_Msg_N ("storage pool already given for &", Nam);
2497 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
2499 if not Denotes_Variable (Expr) then
2500 Error_Msg_N ("storage pool must be a variable", Expr);
2504 if Nkind (Expr) = N_Type_Conversion then
2505 T := Etype (Expression (Expr));
2510 -- The Stack_Bounded_Pool is used internally for implementing
2511 -- access types with a Storage_Size. Since it only work properly
2512 -- when used on one specific type, we need to check that it is not
2513 -- hijacked improperly:
2515 -- type T is access Integer;
2516 -- for T'Storage_Size use n;
2517 -- type Q is access Float;
2518 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
2520 if RTE_Available (RE_Stack_Bounded_Pool)
2521 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
2523 Error_Msg_N ("non-shareable internal Pool", Expr);
2527 -- If the argument is a name that is not an entity name, then
2528 -- we construct a renaming operation to define an entity of
2529 -- type storage pool.
2531 if not Is_Entity_Name (Expr)
2532 and then Is_Object_Reference (Expr)
2534 Pool := Make_Temporary (Loc, 'P', Expr);
2537 Rnode : constant Node_Id :=
2538 Make_Object_Renaming_Declaration (Loc,
2539 Defining_Identifier => Pool,
2541 New_Occurrence_Of (Etype (Expr), Loc),
2545 Insert_Before (N, Rnode);
2547 Set_Associated_Storage_Pool (U_Ent, Pool);
2550 elsif Is_Entity_Name (Expr) then
2551 Pool := Entity (Expr);
2553 -- If pool is a renamed object, get original one. This can
2554 -- happen with an explicit renaming, and within instances.
2556 while Present (Renamed_Object (Pool))
2557 and then Is_Entity_Name (Renamed_Object (Pool))
2559 Pool := Entity (Renamed_Object (Pool));
2562 if Present (Renamed_Object (Pool))
2563 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
2564 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
2566 Pool := Entity (Expression (Renamed_Object (Pool)));
2569 Set_Associated_Storage_Pool (U_Ent, Pool);
2571 elsif Nkind (Expr) = N_Type_Conversion
2572 and then Is_Entity_Name (Expression (Expr))
2573 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
2575 Pool := Entity (Expression (Expr));
2576 Set_Associated_Storage_Pool (U_Ent, Pool);
2579 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
2588 -- Storage_Size attribute definition clause
2590 when Attribute_Storage_Size => Storage_Size : declare
2591 Btype : constant Entity_Id := Base_Type (U_Ent);
2595 if Is_Task_Type (U_Ent) then
2596 Check_Restriction (No_Obsolescent_Features, N);
2598 if Warn_On_Obsolescent_Feature then
2600 ("storage size clause for task is an " &
2601 "obsolescent feature (RM J.9)?", N);
2602 Error_Msg_N ("\use Storage_Size pragma instead?", N);
2608 if not Is_Access_Type (U_Ent)
2609 and then Ekind (U_Ent) /= E_Task_Type
2611 Error_Msg_N ("storage size cannot be given for &", Nam);
2613 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
2615 ("storage size cannot be given for a derived access type",
2618 elsif Duplicate_Clause then
2622 Analyze_And_Resolve (Expr, Any_Integer);
2624 if Is_Access_Type (U_Ent) then
2625 if Present (Associated_Storage_Pool (U_Ent)) then
2626 Error_Msg_N ("storage pool already given for &", Nam);
2630 if Is_OK_Static_Expression (Expr)
2631 and then Expr_Value (Expr) = 0
2633 Set_No_Pool_Assigned (Btype);
2636 else -- Is_Task_Type (U_Ent)
2637 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
2639 if Present (Sprag) then
2640 Error_Msg_Sloc := Sloc (Sprag);
2642 ("Storage_Size already specified#", Nam);
2647 Set_Has_Storage_Size_Clause (Btype);
2655 when Attribute_Stream_Size => Stream_Size : declare
2656 Size : constant Uint := Static_Integer (Expr);
2659 if Ada_Version <= Ada_95 then
2660 Check_Restriction (No_Implementation_Attributes, N);
2663 if Duplicate_Clause then
2666 elsif Is_Elementary_Type (U_Ent) then
2667 if Size /= System_Storage_Unit
2669 Size /= System_Storage_Unit * 2
2671 Size /= System_Storage_Unit * 4
2673 Size /= System_Storage_Unit * 8
2675 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
2677 ("stream size for elementary type must be a"
2678 & " power of 2 and at least ^", N);
2680 elsif RM_Size (U_Ent) > Size then
2681 Error_Msg_Uint_1 := RM_Size (U_Ent);
2683 ("stream size for elementary type must be a"
2684 & " power of 2 and at least ^", N);
2687 Set_Has_Stream_Size_Clause (U_Ent);
2690 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
2698 -- Value_Size attribute definition clause
2700 when Attribute_Value_Size => Value_Size : declare
2701 Size : constant Uint := Static_Integer (Expr);
2705 if not Is_Type (U_Ent) then
2706 Error_Msg_N ("Value_Size cannot be given for &", Nam);
2708 elsif Duplicate_Clause then
2711 elsif Is_Array_Type (U_Ent)
2712 and then not Is_Constrained (U_Ent)
2715 ("Value_Size cannot be given for unconstrained array", Nam);
2718 if Is_Elementary_Type (U_Ent) then
2719 Check_Size (Expr, U_Ent, Size, Biased);
2720 Set_Biased (U_Ent, N, "value size clause", Biased);
2723 Set_RM_Size (U_Ent, Size);
2731 when Attribute_Write =>
2732 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
2733 Set_Has_Specified_Stream_Write (Ent);
2735 -- All other attributes cannot be set
2739 ("attribute& cannot be set with definition clause", N);
2742 -- The test for the type being frozen must be performed after any
2743 -- expression the clause has been analyzed since the expression itself
2744 -- might cause freezing that makes the clause illegal.
2746 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
2749 end Analyze_Attribute_Definition_Clause;
2751 ----------------------------
2752 -- Analyze_Code_Statement --
2753 ----------------------------
2755 procedure Analyze_Code_Statement (N : Node_Id) is
2756 HSS : constant Node_Id := Parent (N);
2757 SBody : constant Node_Id := Parent (HSS);
2758 Subp : constant Entity_Id := Current_Scope;
2765 -- Analyze and check we get right type, note that this implements the
2766 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
2767 -- is the only way that Asm_Insn could possibly be visible.
2769 Analyze_And_Resolve (Expression (N));
2771 if Etype (Expression (N)) = Any_Type then
2773 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
2774 Error_Msg_N ("incorrect type for code statement", N);
2778 Check_Code_Statement (N);
2780 -- Make sure we appear in the handled statement sequence of a
2781 -- subprogram (RM 13.8(3)).
2783 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2784 or else Nkind (SBody) /= N_Subprogram_Body
2787 ("code statement can only appear in body of subprogram", N);
2791 -- Do remaining checks (RM 13.8(3)) if not already done
2793 if not Is_Machine_Code_Subprogram (Subp) then
2794 Set_Is_Machine_Code_Subprogram (Subp);
2796 -- No exception handlers allowed
2798 if Present (Exception_Handlers (HSS)) then
2800 ("exception handlers not permitted in machine code subprogram",
2801 First (Exception_Handlers (HSS)));
2804 -- No declarations other than use clauses and pragmas (we allow
2805 -- certain internally generated declarations as well).
2807 Decl := First (Declarations (SBody));
2808 while Present (Decl) loop
2809 DeclO := Original_Node (Decl);
2810 if Comes_From_Source (DeclO)
2811 and not Nkind_In (DeclO, N_Pragma,
2812 N_Use_Package_Clause,
2814 N_Implicit_Label_Declaration)
2817 ("this declaration not allowed in machine code subprogram",
2824 -- No statements other than code statements, pragmas, and labels.
2825 -- Again we allow certain internally generated statements.
2827 Stmt := First (Statements (HSS));
2828 while Present (Stmt) loop
2829 StmtO := Original_Node (Stmt);
2830 if Comes_From_Source (StmtO)
2831 and then not Nkind_In (StmtO, N_Pragma,
2836 ("this statement is not allowed in machine code subprogram",
2843 end Analyze_Code_Statement;
2845 -----------------------------------------------
2846 -- Analyze_Enumeration_Representation_Clause --
2847 -----------------------------------------------
2849 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2850 Ident : constant Node_Id := Identifier (N);
2851 Aggr : constant Node_Id := Array_Aggregate (N);
2852 Enumtype : Entity_Id;
2859 Err : Boolean := False;
2860 -- Set True to avoid cascade errors and crashes on incorrect source code
2862 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2863 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2864 -- Allowed range of universal integer (= allowed range of enum lit vals)
2868 -- Minimum and maximum values of entries
2871 -- Pointer to node for literal providing max value
2874 if Ignore_Rep_Clauses then
2878 -- First some basic error checks
2881 Enumtype := Entity (Ident);
2883 if Enumtype = Any_Type
2884 or else Rep_Item_Too_Early (Enumtype, N)
2888 Enumtype := Underlying_Type (Enumtype);
2891 if not Is_Enumeration_Type (Enumtype) then
2893 ("enumeration type required, found}",
2894 Ident, First_Subtype (Enumtype));
2898 -- Ignore rep clause on generic actual type. This will already have
2899 -- been flagged on the template as an error, and this is the safest
2900 -- way to ensure we don't get a junk cascaded message in the instance.
2902 if Is_Generic_Actual_Type (Enumtype) then
2905 -- Type must be in current scope
2907 elsif Scope (Enumtype) /= Current_Scope then
2908 Error_Msg_N ("type must be declared in this scope", Ident);
2911 -- Type must be a first subtype
2913 elsif not Is_First_Subtype (Enumtype) then
2914 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2917 -- Ignore duplicate rep clause
2919 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2920 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2923 -- Don't allow rep clause for standard [wide_[wide_]]character
2925 elsif Is_Standard_Character_Type (Enumtype) then
2926 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2929 -- Check that the expression is a proper aggregate (no parentheses)
2931 elsif Paren_Count (Aggr) /= 0 then
2933 ("extra parentheses surrounding aggregate not allowed",
2937 -- All tests passed, so set rep clause in place
2940 Set_Has_Enumeration_Rep_Clause (Enumtype);
2941 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2944 -- Now we process the aggregate. Note that we don't use the normal
2945 -- aggregate code for this purpose, because we don't want any of the
2946 -- normal expansion activities, and a number of special semantic
2947 -- rules apply (including the component type being any integer type)
2949 Elit := First_Literal (Enumtype);
2951 -- First the positional entries if any
2953 if Present (Expressions (Aggr)) then
2954 Expr := First (Expressions (Aggr));
2955 while Present (Expr) loop
2957 Error_Msg_N ("too many entries in aggregate", Expr);
2961 Val := Static_Integer (Expr);
2963 -- Err signals that we found some incorrect entries processing
2964 -- the list. The final checks for completeness and ordering are
2965 -- skipped in this case.
2967 if Val = No_Uint then
2969 elsif Val < Lo or else Hi < Val then
2970 Error_Msg_N ("value outside permitted range", Expr);
2974 Set_Enumeration_Rep (Elit, Val);
2975 Set_Enumeration_Rep_Expr (Elit, Expr);
2981 -- Now process the named entries if present
2983 if Present (Component_Associations (Aggr)) then
2984 Assoc := First (Component_Associations (Aggr));
2985 while Present (Assoc) loop
2986 Choice := First (Choices (Assoc));
2988 if Present (Next (Choice)) then
2990 ("multiple choice not allowed here", Next (Choice));
2994 if Nkind (Choice) = N_Others_Choice then
2995 Error_Msg_N ("others choice not allowed here", Choice);
2998 elsif Nkind (Choice) = N_Range then
3000 -- ??? should allow zero/one element range here
3002 Error_Msg_N ("range not allowed here", Choice);
3006 Analyze_And_Resolve (Choice, Enumtype);
3008 if Error_Posted (Choice) then
3013 if Is_Entity_Name (Choice)
3014 and then Is_Type (Entity (Choice))
3016 Error_Msg_N ("subtype name not allowed here", Choice);
3019 -- ??? should allow static subtype with zero/one entry
3021 elsif Etype (Choice) = Base_Type (Enumtype) then
3022 if not Is_Static_Expression (Choice) then
3023 Flag_Non_Static_Expr
3024 ("non-static expression used for choice!", Choice);
3028 Elit := Expr_Value_E (Choice);
3030 if Present (Enumeration_Rep_Expr (Elit)) then
3032 Sloc (Enumeration_Rep_Expr (Elit));
3034 ("representation for& previously given#",
3039 Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
3041 Expr := Expression (Assoc);
3042 Val := Static_Integer (Expr);
3044 if Val = No_Uint then
3047 elsif Val < Lo or else Hi < Val then
3048 Error_Msg_N ("value outside permitted range", Expr);
3052 Set_Enumeration_Rep (Elit, Val);
3062 -- Aggregate is fully processed. Now we check that a full set of
3063 -- representations was given, and that they are in range and in order.
3064 -- These checks are only done if no other errors occurred.
3070 Elit := First_Literal (Enumtype);
3071 while Present (Elit) loop
3072 if No (Enumeration_Rep_Expr (Elit)) then
3073 Error_Msg_NE ("missing representation for&!", N, Elit);
3076 Val := Enumeration_Rep (Elit);
3078 if Min = No_Uint then
3082 if Val /= No_Uint then
3083 if Max /= No_Uint and then Val <= Max then
3085 ("enumeration value for& not ordered!",
3086 Enumeration_Rep_Expr (Elit), Elit);
3089 Max_Node := Enumeration_Rep_Expr (Elit);
3093 -- If there is at least one literal whose representation is not
3094 -- equal to the Pos value, then note that this enumeration type
3095 -- has a non-standard representation.
3097 if Val /= Enumeration_Pos (Elit) then
3098 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
3105 -- Now set proper size information
3108 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
3111 if Has_Size_Clause (Enumtype) then
3113 -- All OK, if size is OK now
3115 if RM_Size (Enumtype) >= Minsize then
3119 -- Try if we can get by with biasing
3122 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
3124 -- Error message if even biasing does not work
3126 if RM_Size (Enumtype) < Minsize then
3127 Error_Msg_Uint_1 := RM_Size (Enumtype);
3128 Error_Msg_Uint_2 := Max;
3130 ("previously given size (^) is too small "
3131 & "for this value (^)", Max_Node);
3133 -- If biasing worked, indicate that we now have biased rep
3137 (Enumtype, Size_Clause (Enumtype), "size clause");
3142 Set_RM_Size (Enumtype, Minsize);
3143 Set_Enum_Esize (Enumtype);
3146 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
3147 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
3148 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
3152 -- We repeat the too late test in case it froze itself!
3154 if Rep_Item_Too_Late (Enumtype, N) then
3157 end Analyze_Enumeration_Representation_Clause;
3159 ----------------------------
3160 -- Analyze_Free_Statement --
3161 ----------------------------
3163 procedure Analyze_Free_Statement (N : Node_Id) is
3165 Analyze (Expression (N));
3166 end Analyze_Free_Statement;
3168 ---------------------------
3169 -- Analyze_Freeze_Entity --
3170 ---------------------------
3172 procedure Analyze_Freeze_Entity (N : Node_Id) is
3173 E : constant Entity_Id := Entity (N);
3176 -- Remember that we are processing a freezing entity. Required to
3177 -- ensure correct decoration of internal entities associated with
3178 -- interfaces (see New_Overloaded_Entity).
3180 Inside_Freezing_Actions := Inside_Freezing_Actions + 1;
3182 -- For tagged types covering interfaces add internal entities that link
3183 -- the primitives of the interfaces with the primitives that cover them.
3184 -- Note: These entities were originally generated only when generating
3185 -- code because their main purpose was to provide support to initialize
3186 -- the secondary dispatch tables. They are now generated also when
3187 -- compiling with no code generation to provide ASIS the relationship
3188 -- between interface primitives and tagged type primitives. They are
3189 -- also used to locate primitives covering interfaces when processing
3190 -- generics (see Derive_Subprograms).
3192 if Ada_Version >= Ada_2005
3193 and then Ekind (E) = E_Record_Type
3194 and then Is_Tagged_Type (E)
3195 and then not Is_Interface (E)
3196 and then Has_Interfaces (E)
3198 -- This would be a good common place to call the routine that checks
3199 -- overriding of interface primitives (and thus factorize calls to
3200 -- Check_Abstract_Overriding located at different contexts in the
3201 -- compiler). However, this is not possible because it causes
3202 -- spurious errors in case of late overriding.
3204 Add_Internal_Interface_Entities (E);
3209 if Ekind (E) = E_Record_Type
3210 and then Is_CPP_Class (E)
3211 and then Is_Tagged_Type (E)
3212 and then Tagged_Type_Expansion
3213 and then Expander_Active
3215 if CPP_Num_Prims (E) = 0 then
3217 -- If the CPP type has user defined components then it must import
3218 -- primitives from C++. This is required because if the C++ class
3219 -- has no primitives then the C++ compiler does not added the _tag
3220 -- component to the type.
3222 pragma Assert (Chars (First_Entity (E)) = Name_uTag);
3224 if First_Entity (E) /= Last_Entity (E) then
3226 ("?'C'P'P type must import at least one primitive from C++",
3231 -- Check that all its primitives are abstract or imported from C++.
3232 -- Check also availability of the C++ constructor.
3235 Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
3237 Error_Reported : Boolean := False;
3241 Elmt := First_Elmt (Primitive_Operations (E));
3242 while Present (Elmt) loop
3243 Prim := Node (Elmt);
3245 if Comes_From_Source (Prim) then
3246 if Is_Abstract_Subprogram (Prim) then
3249 elsif not Is_Imported (Prim)
3250 or else Convention (Prim) /= Convention_CPP
3253 ("?primitives of 'C'P'P types must be imported from C++"
3254 & " or abstract", Prim);
3256 elsif not Has_Constructors
3257 and then not Error_Reported
3259 Error_Msg_Name_1 := Chars (E);
3261 ("?'C'P'P constructor required for type %", Prim);
3262 Error_Reported := True;
3271 Inside_Freezing_Actions := Inside_Freezing_Actions - 1;
3273 -- If we have a type with predicates, build predicate function
3275 if Is_Type (E) and then Has_Predicates (E) then
3276 Build_Predicate_Function (E, N);
3279 -- If type has delayed aspects, this is where we do the preanalysis at
3280 -- the freeze point, as part of the consistent visibility check. Note
3281 -- that this must be done after calling Build_Predicate_Function or
3282 -- Build_Invariant_Procedure since these subprograms fix occurrences of
3283 -- the subtype name in the saved expression so that they will not cause
3284 -- trouble in the preanalysis.
3286 if Has_Delayed_Aspects (E) then
3291 -- Look for aspect specification entries for this entity
3293 Ritem := First_Rep_Item (E);
3294 while Present (Ritem) loop
3295 if Nkind (Ritem) = N_Aspect_Specification
3296 and then Entity (Ritem) = E
3297 and then Is_Delayed_Aspect (Ritem)
3299 Check_Aspect_At_Freeze_Point (Ritem);
3302 Next_Rep_Item (Ritem);
3306 end Analyze_Freeze_Entity;
3308 ------------------------------------------
3309 -- Analyze_Record_Representation_Clause --
3310 ------------------------------------------
3312 -- Note: we check as much as we can here, but we can't do any checks
3313 -- based on the position values (e.g. overlap checks) until freeze time
3314 -- because especially in Ada 2005 (machine scalar mode), the processing
3315 -- for non-standard bit order can substantially change the positions.
3316 -- See procedure Check_Record_Representation_Clause (called from Freeze)
3317 -- for the remainder of this processing.
3319 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
3320 Ident : constant Node_Id := Identifier (N);
3325 Hbit : Uint := Uint_0;
3329 Rectype : Entity_Id;
3331 CR_Pragma : Node_Id := Empty;
3332 -- Points to N_Pragma node if Complete_Representation pragma present
3335 if Ignore_Rep_Clauses then
3340 Rectype := Entity (Ident);
3342 if Rectype = Any_Type
3343 or else Rep_Item_Too_Early (Rectype, N)
3347 Rectype := Underlying_Type (Rectype);
3350 -- First some basic error checks
3352 if not Is_Record_Type (Rectype) then
3354 ("record type required, found}", Ident, First_Subtype (Rectype));
3357 elsif Scope (Rectype) /= Current_Scope then
3358 Error_Msg_N ("type must be declared in this scope", N);
3361 elsif not Is_First_Subtype (Rectype) then
3362 Error_Msg_N ("cannot give record rep clause for subtype", N);
3365 elsif Has_Record_Rep_Clause (Rectype) then
3366 Error_Msg_N ("duplicate record rep clause ignored", N);
3369 elsif Rep_Item_Too_Late (Rectype, N) then
3373 if Present (Mod_Clause (N)) then
3375 Loc : constant Source_Ptr := Sloc (N);
3376 M : constant Node_Id := Mod_Clause (N);
3377 P : constant List_Id := Pragmas_Before (M);
3381 pragma Warnings (Off, Mod_Val);
3384 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
3386 if Warn_On_Obsolescent_Feature then
3388 ("mod clause is an obsolescent feature (RM J.8)?", N);
3390 ("\use alignment attribute definition clause instead?", N);
3397 -- In ASIS_Mode mode, expansion is disabled, but we must convert
3398 -- the Mod clause into an alignment clause anyway, so that the
3399 -- back-end can compute and back-annotate properly the size and
3400 -- alignment of types that may include this record.
3402 -- This seems dubious, this destroys the source tree in a manner
3403 -- not detectable by ASIS ???
3405 if Operating_Mode = Check_Semantics
3409 Make_Attribute_Definition_Clause (Loc,
3410 Name => New_Reference_To (Base_Type (Rectype), Loc),
3411 Chars => Name_Alignment,
3412 Expression => Relocate_Node (Expression (M)));
3414 Set_From_At_Mod (AtM_Nod);
3415 Insert_After (N, AtM_Nod);
3416 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
3417 Set_Mod_Clause (N, Empty);
3420 -- Get the alignment value to perform error checking
3422 Mod_Val := Get_Alignment_Value (Expression (M));
3427 -- For untagged types, clear any existing component clauses for the
3428 -- type. If the type is derived, this is what allows us to override
3429 -- a rep clause for the parent. For type extensions, the representation
3430 -- of the inherited components is inherited, so we want to keep previous
3431 -- component clauses for completeness.
3433 if not Is_Tagged_Type (Rectype) then
3434 Comp := First_Component_Or_Discriminant (Rectype);
3435 while Present (Comp) loop
3436 Set_Component_Clause (Comp, Empty);
3437 Next_Component_Or_Discriminant (Comp);
3441 -- All done if no component clauses
3443 CC := First (Component_Clauses (N));
3449 -- A representation like this applies to the base type
3451 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
3452 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
3453 Set_Has_Specified_Layout (Base_Type (Rectype));
3455 -- Process the component clauses
3457 while Present (CC) loop
3461 if Nkind (CC) = N_Pragma then
3464 -- The only pragma of interest is Complete_Representation
3466 if Pragma_Name (CC) = Name_Complete_Representation then
3470 -- Processing for real component clause
3473 Posit := Static_Integer (Position (CC));
3474 Fbit := Static_Integer (First_Bit (CC));
3475 Lbit := Static_Integer (Last_Bit (CC));
3478 and then Fbit /= No_Uint
3479 and then Lbit /= No_Uint
3483 ("position cannot be negative", Position (CC));
3487 ("first bit cannot be negative", First_Bit (CC));
3489 -- The Last_Bit specified in a component clause must not be
3490 -- less than the First_Bit minus one (RM-13.5.1(10)).
3492 elsif Lbit < Fbit - 1 then
3494 ("last bit cannot be less than first bit minus one",
3497 -- Values look OK, so find the corresponding record component
3498 -- Even though the syntax allows an attribute reference for
3499 -- implementation-defined components, GNAT does not allow the
3500 -- tag to get an explicit position.
3502 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
3503 if Attribute_Name (Component_Name (CC)) = Name_Tag then
3504 Error_Msg_N ("position of tag cannot be specified", CC);
3506 Error_Msg_N ("illegal component name", CC);
3510 Comp := First_Entity (Rectype);
3511 while Present (Comp) loop
3512 exit when Chars (Comp) = Chars (Component_Name (CC));
3518 -- Maybe component of base type that is absent from
3519 -- statically constrained first subtype.
3521 Comp := First_Entity (Base_Type (Rectype));
3522 while Present (Comp) loop
3523 exit when Chars (Comp) = Chars (Component_Name (CC));
3530 ("component clause is for non-existent field", CC);
3532 -- Ada 2012 (AI05-0026): Any name that denotes a
3533 -- discriminant of an object of an unchecked union type
3534 -- shall not occur within a record_representation_clause.
3536 -- The general restriction of using record rep clauses on
3537 -- Unchecked_Union types has now been lifted. Since it is
3538 -- possible to introduce a record rep clause which mentions
3539 -- the discriminant of an Unchecked_Union in non-Ada 2012
3540 -- code, this check is applied to all versions of the
3543 elsif Ekind (Comp) = E_Discriminant
3544 and then Is_Unchecked_Union (Rectype)
3547 ("cannot reference discriminant of Unchecked_Union",
3548 Component_Name (CC));
3550 elsif Present (Component_Clause (Comp)) then
3552 -- Diagnose duplicate rep clause, or check consistency
3553 -- if this is an inherited component. In a double fault,
3554 -- there may be a duplicate inconsistent clause for an
3555 -- inherited component.
3557 if Scope (Original_Record_Component (Comp)) = Rectype
3558 or else Parent (Component_Clause (Comp)) = N
3560 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
3561 Error_Msg_N ("component clause previously given#", CC);
3565 Rep1 : constant Node_Id := Component_Clause (Comp);
3567 if Intval (Position (Rep1)) /=
3568 Intval (Position (CC))
3569 or else Intval (First_Bit (Rep1)) /=
3570 Intval (First_Bit (CC))
3571 or else Intval (Last_Bit (Rep1)) /=
3572 Intval (Last_Bit (CC))
3574 Error_Msg_N ("component clause inconsistent "
3575 & "with representation of ancestor", CC);
3576 elsif Warn_On_Redundant_Constructs then
3577 Error_Msg_N ("?redundant component clause "
3578 & "for inherited component!", CC);
3583 -- Normal case where this is the first component clause we
3584 -- have seen for this entity, so set it up properly.
3587 -- Make reference for field in record rep clause and set
3588 -- appropriate entity field in the field identifier.
3591 (Comp, Component_Name (CC), Set_Ref => False);
3592 Set_Entity (Component_Name (CC), Comp);
3594 -- Update Fbit and Lbit to the actual bit number
3596 Fbit := Fbit + UI_From_Int (SSU) * Posit;
3597 Lbit := Lbit + UI_From_Int (SSU) * Posit;
3599 if Has_Size_Clause (Rectype)
3600 and then RM_Size (Rectype) <= Lbit
3603 ("bit number out of range of specified size",
3606 Set_Component_Clause (Comp, CC);
3607 Set_Component_Bit_Offset (Comp, Fbit);
3608 Set_Esize (Comp, 1 + (Lbit - Fbit));
3609 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
3610 Set_Normalized_Position (Comp, Fbit / SSU);
3612 if Warn_On_Overridden_Size
3613 and then Has_Size_Clause (Etype (Comp))
3614 and then RM_Size (Etype (Comp)) /= Esize (Comp)
3617 ("?component size overrides size clause for&",
3618 Component_Name (CC), Etype (Comp));
3621 -- This information is also set in the corresponding
3622 -- component of the base type, found by accessing the
3623 -- Original_Record_Component link if it is present.
3625 Ocomp := Original_Record_Component (Comp);
3632 (Component_Name (CC),
3638 (Comp, First_Node (CC), "component clause", Biased);
3640 if Present (Ocomp) then
3641 Set_Component_Clause (Ocomp, CC);
3642 Set_Component_Bit_Offset (Ocomp, Fbit);
3643 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
3644 Set_Normalized_Position (Ocomp, Fbit / SSU);
3645 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
3647 Set_Normalized_Position_Max
3648 (Ocomp, Normalized_Position (Ocomp));
3650 -- Note: we don't use Set_Biased here, because we
3651 -- already gave a warning above if needed, and we
3652 -- would get a duplicate for the same name here.
3654 Set_Has_Biased_Representation
3655 (Ocomp, Has_Biased_Representation (Comp));
3658 if Esize (Comp) < 0 then
3659 Error_Msg_N ("component size is negative", CC);
3670 -- Check missing components if Complete_Representation pragma appeared
3672 if Present (CR_Pragma) then
3673 Comp := First_Component_Or_Discriminant (Rectype);
3674 while Present (Comp) loop
3675 if No (Component_Clause (Comp)) then
3677 ("missing component clause for &", CR_Pragma, Comp);
3680 Next_Component_Or_Discriminant (Comp);
3683 -- If no Complete_Representation pragma, warn if missing components
3685 elsif Warn_On_Unrepped_Components then
3687 Num_Repped_Components : Nat := 0;
3688 Num_Unrepped_Components : Nat := 0;
3691 -- First count number of repped and unrepped components
3693 Comp := First_Component_Or_Discriminant (Rectype);
3694 while Present (Comp) loop
3695 if Present (Component_Clause (Comp)) then
3696 Num_Repped_Components := Num_Repped_Components + 1;
3698 Num_Unrepped_Components := Num_Unrepped_Components + 1;
3701 Next_Component_Or_Discriminant (Comp);
3704 -- We are only interested in the case where there is at least one
3705 -- unrepped component, and at least half the components have rep
3706 -- clauses. We figure that if less than half have them, then the
3707 -- partial rep clause is really intentional. If the component
3708 -- type has no underlying type set at this point (as for a generic
3709 -- formal type), we don't know enough to give a warning on the
3712 if Num_Unrepped_Components > 0
3713 and then Num_Unrepped_Components < Num_Repped_Components
3715 Comp := First_Component_Or_Discriminant (Rectype);
3716 while Present (Comp) loop
3717 if No (Component_Clause (Comp))
3718 and then Comes_From_Source (Comp)
3719 and then Present (Underlying_Type (Etype (Comp)))
3720 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
3721 or else Size_Known_At_Compile_Time
3722 (Underlying_Type (Etype (Comp))))
3723 and then not Has_Warnings_Off (Rectype)
3725 Error_Msg_Sloc := Sloc (Comp);
3727 ("?no component clause given for & declared #",
3731 Next_Component_Or_Discriminant (Comp);
3736 end Analyze_Record_Representation_Clause;
3738 -------------------------------
3739 -- Build_Invariant_Procedure --
3740 -------------------------------
3742 -- The procedure that is constructed here has the form
3744 -- procedure typInvariant (Ixxx : typ) is
3746 -- pragma Check (Invariant, exp, "failed invariant from xxx");
3747 -- pragma Check (Invariant, exp, "failed invariant from xxx");
3749 -- pragma Check (Invariant, exp, "failed inherited invariant from xxx");
3751 -- end typInvariant;
3753 procedure Build_Invariant_Procedure (Typ : Entity_Id; N : Node_Id) is
3754 Loc : constant Source_Ptr := Sloc (Typ);
3761 Visible_Decls : constant List_Id := Visible_Declarations (N);
3762 Private_Decls : constant List_Id := Private_Declarations (N);
3764 procedure Add_Invariants (T : Entity_Id; Inherit : Boolean);
3765 -- Appends statements to Stmts for any invariants in the rep item chain
3766 -- of the given type. If Inherit is False, then we only process entries
3767 -- on the chain for the type Typ. If Inherit is True, then we ignore any
3768 -- Invariant aspects, but we process all Invariant'Class aspects, adding
3769 -- "inherited" to the exception message and generating an informational
3770 -- message about the inheritance of an invariant.
3772 Object_Name : constant Name_Id := New_Internal_Name ('I');
3773 -- Name for argument of invariant procedure
3775 Object_Entity : constant Node_Id :=
3776 Make_Defining_Identifier (Loc, Object_Name);
3777 -- The procedure declaration entity for the argument
3779 --------------------
3780 -- Add_Invariants --
3781 --------------------
3783 procedure Add_Invariants (T : Entity_Id; Inherit : Boolean) is
3793 procedure Replace_Type_Reference (N : Node_Id);
3794 -- Replace a single occurrence N of the subtype name with a reference
3795 -- to the formal of the predicate function. N can be an identifier
3796 -- referencing the subtype, or a selected component, representing an
3797 -- appropriately qualified occurrence of the subtype name.
3799 procedure Replace_Type_References is
3800 new Replace_Type_References_Generic (Replace_Type_Reference);
3801 -- Traverse an expression replacing all occurrences of the subtype
3802 -- name with appropriate references to the object that is the formal
3803 -- parameter of the predicate function. Note that we must ensure
3804 -- that the type and entity information is properly set in the
3805 -- replacement node, since we will do a Preanalyze call of this
3806 -- expression without proper visibility of the procedure argument.
3808 ----------------------------
3809 -- Replace_Type_Reference --
3810 ----------------------------
3812 procedure Replace_Type_Reference (N : Node_Id) is
3814 -- Invariant'Class, replace with T'Class (obj)
3816 if Class_Present (Ritem) then
3818 Make_Type_Conversion (Loc,
3820 Make_Attribute_Reference (Loc,
3821 Prefix => New_Occurrence_Of (T, Loc),
3822 Attribute_Name => Name_Class),
3823 Expression => Make_Identifier (Loc, Object_Name)));
3825 Set_Entity (Expression (N), Object_Entity);
3826 Set_Etype (Expression (N), Typ);
3828 -- Invariant, replace with obj
3831 Rewrite (N, Make_Identifier (Loc, Object_Name));
3832 Set_Entity (N, Object_Entity);
3835 end Replace_Type_Reference;
3837 -- Start of processing for Add_Invariants
3840 Ritem := First_Rep_Item (T);
3841 while Present (Ritem) loop
3842 if Nkind (Ritem) = N_Pragma
3843 and then Pragma_Name (Ritem) = Name_Invariant
3845 Arg1 := First (Pragma_Argument_Associations (Ritem));
3846 Arg2 := Next (Arg1);
3847 Arg3 := Next (Arg2);
3849 Arg1 := Get_Pragma_Arg (Arg1);
3850 Arg2 := Get_Pragma_Arg (Arg2);
3852 -- For Inherit case, ignore Invariant, process only Class case
3855 if not Class_Present (Ritem) then
3859 -- For Inherit false, process only item for right type
3862 if Entity (Arg1) /= Typ then
3868 Stmts := Empty_List;
3871 Exp := New_Copy_Tree (Arg2);
3874 -- We need to replace any occurrences of the name of the type
3875 -- with references to the object, converted to type'Class in
3876 -- the case of Invariant'Class aspects.
3878 Replace_Type_References (Exp, Chars (T));
3880 -- If this invariant comes from an aspect, find the aspect
3881 -- specification, and replace the saved expression because
3882 -- we need the subtype references replaced for the calls to
3883 -- Preanalyze_Spec_Expressin in Check_Aspect_At_Freeze_Point
3884 -- and Check_Aspect_At_End_Of_Declarations.
3886 if From_Aspect_Specification (Ritem) then
3891 -- Loop to find corresponding aspect, note that this
3892 -- must be present given the pragma is marked delayed.
3894 Aitem := Next_Rep_Item (Ritem);
3895 while Present (Aitem) loop
3896 if Nkind (Aitem) = N_Aspect_Specification
3897 and then Aspect_Rep_Item (Aitem) = Ritem
3900 (Identifier (Aitem), New_Copy_Tree (Exp));
3904 Aitem := Next_Rep_Item (Aitem);
3909 -- Now we need to preanalyze the expression to properly capture
3910 -- the visibility in the visible part. The expression will not
3911 -- be analyzed for real until the body is analyzed, but that is
3912 -- at the end of the private part and has the wrong visibility.
3914 Set_Parent (Exp, N);
3915 Preanalyze_Spec_Expression (Exp, Standard_Boolean);
3917 -- Build first two arguments for Check pragma
3920 Make_Pragma_Argument_Association (Loc,
3921 Expression => Make_Identifier (Loc, Name_Invariant)),
3922 Make_Pragma_Argument_Association (Loc, Expression => Exp));
3924 -- Add message if present in Invariant pragma
3926 if Present (Arg3) then
3927 Str := Strval (Get_Pragma_Arg (Arg3));
3929 -- If inherited case, and message starts "failed invariant",
3930 -- change it to be "failed inherited invariant".
3933 String_To_Name_Buffer (Str);
3935 if Name_Buffer (1 .. 16) = "failed invariant" then
3936 Insert_Str_In_Name_Buffer ("inherited ", 8);
3937 Str := String_From_Name_Buffer;
3942 Make_Pragma_Argument_Association (Loc,
3943 Expression => Make_String_Literal (Loc, Str)));
3946 -- Add Check pragma to list of statements
3950 Pragma_Identifier =>
3951 Make_Identifier (Loc, Name_Check),
3952 Pragma_Argument_Associations => Assoc));
3954 -- If Inherited case and option enabled, output info msg. Note
3955 -- that we know this is a case of Invariant'Class.
3957 if Inherit and Opt.List_Inherited_Aspects then
3958 Error_Msg_Sloc := Sloc (Ritem);
3960 ("?info: & inherits `Invariant''Class` aspect from #",
3966 Next_Rep_Item (Ritem);
3970 -- Start of processing for Build_Invariant_Procedure
3976 Set_Etype (Object_Entity, Typ);
3978 -- Add invariants for the current type
3980 Add_Invariants (Typ, Inherit => False);
3982 -- Add invariants for parent types
3985 Current_Typ : Entity_Id;
3986 Parent_Typ : Entity_Id;
3991 Parent_Typ := Etype (Current_Typ);
3993 if Is_Private_Type (Parent_Typ)
3994 and then Present (Full_View (Base_Type (Parent_Typ)))
3996 Parent_Typ := Full_View (Base_Type (Parent_Typ));
3999 exit when Parent_Typ = Current_Typ;
4001 Current_Typ := Parent_Typ;
4002 Add_Invariants (Current_Typ, Inherit => True);
4006 -- Build the procedure if we generated at least one Check pragma
4008 if Stmts /= No_List then
4010 -- Build procedure declaration
4013 Make_Defining_Identifier (Loc,
4014 Chars => New_External_Name (Chars (Typ), "Invariant"));
4015 Set_Has_Invariants (SId);
4016 Set_Invariant_Procedure (Typ, SId);
4019 Make_Procedure_Specification (Loc,
4020 Defining_Unit_Name => SId,
4021 Parameter_Specifications => New_List (
4022 Make_Parameter_Specification (Loc,
4023 Defining_Identifier => Object_Entity,
4024 Parameter_Type => New_Occurrence_Of (Typ, Loc))));
4026 PDecl := Make_Subprogram_Declaration (Loc, Specification => Spec);
4028 -- Build procedure body
4031 Make_Defining_Identifier (Loc,
4032 Chars => New_External_Name (Chars (Typ), "Invariant"));
4035 Make_Procedure_Specification (Loc,
4036 Defining_Unit_Name => SId,
4037 Parameter_Specifications => New_List (
4038 Make_Parameter_Specification (Loc,
4039 Defining_Identifier =>
4040 Make_Defining_Identifier (Loc, Object_Name),
4041 Parameter_Type => New_Occurrence_Of (Typ, Loc))));
4044 Make_Subprogram_Body (Loc,
4045 Specification => Spec,
4046 Declarations => Empty_List,
4047 Handled_Statement_Sequence =>
4048 Make_Handled_Sequence_Of_Statements (Loc,
4049 Statements => Stmts));
4051 -- Insert procedure declaration and spec at the appropriate points.
4052 -- Skip this if there are no private declarations (that's an error
4053 -- that will be diagnosed elsewhere, and there is no point in having
4054 -- an invariant procedure set if the full declaration is missing).
4056 if Present (Private_Decls) then
4058 -- The spec goes at the end of visible declarations, but they have
4059 -- already been analyzed, so we need to explicitly do the analyze.
4061 Append_To (Visible_Decls, PDecl);
4064 -- The body goes at the end of the private declarations, which we
4065 -- have not analyzed yet, so we do not need to perform an explicit
4066 -- analyze call. We skip this if there are no private declarations
4067 -- (this is an error that will be caught elsewhere);
4069 Append_To (Private_Decls, PBody);
4072 end Build_Invariant_Procedure;
4074 ------------------------------
4075 -- Build_Predicate_Function --
4076 ------------------------------
4078 -- The procedure that is constructed here has the form
4080 -- function typPredicate (Ixxx : typ) return Boolean is
4083 -- exp1 and then exp2 and then ...
4084 -- and then typ1Predicate (typ1 (Ixxx))
4085 -- and then typ2Predicate (typ2 (Ixxx))
4087 -- end typPredicate;
4089 -- Here exp1, and exp2 are expressions from Predicate pragmas. Note that
4090 -- this is the point at which these expressions get analyzed, providing the
4091 -- required delay, and typ1, typ2, are entities from which predicates are
4092 -- inherited. Note that we do NOT generate Check pragmas, that's because we
4093 -- use this function even if checks are off, e.g. for membership tests.
4095 procedure Build_Predicate_Function (Typ : Entity_Id; N : Node_Id) is
4096 Loc : constant Source_Ptr := Sloc (Typ);
4103 -- This is the expression for the return statement in the function. It
4104 -- is build by connecting the component predicates with AND THEN.
4106 procedure Add_Call (T : Entity_Id);
4107 -- Includes a call to the predicate function for type T in Expr if T
4108 -- has predicates and Predicate_Function (T) is non-empty.
4110 procedure Add_Predicates;
4111 -- Appends expressions for any Predicate pragmas in the rep item chain
4112 -- Typ to Expr. Note that we look only at items for this exact entity.
4113 -- Inheritance of predicates for the parent type is done by calling the
4114 -- Predicate_Function of the parent type, using Add_Call above.
4116 Object_Name : constant Name_Id := New_Internal_Name ('I');
4117 -- Name for argument of Predicate procedure
4119 Object_Entity : constant Entity_Id :=
4120 Make_Defining_Identifier (Loc, Object_Name);
4121 -- The entity for the spec entity for the argument
4123 Dynamic_Predicate_Present : Boolean := False;
4124 -- Set True if a dynamic predicate is present, results in the entire
4125 -- predicate being considered dynamic even if it looks static
4127 Static_Predicate_Present : Node_Id := Empty;
4128 -- Set to N_Pragma node for a static predicate if one is encountered.
4134 procedure Add_Call (T : Entity_Id) is
4138 if Present (T) and then Present (Predicate_Function (T)) then
4139 Set_Has_Predicates (Typ);
4141 -- Build the call to the predicate function of T
4145 (T, Convert_To (T, Make_Identifier (Loc, Object_Name)));
4147 -- Add call to evolving expression, using AND THEN if needed
4154 Left_Opnd => Relocate_Node (Expr),
4158 -- Output info message on inheritance if required. Note we do not
4159 -- give this information for generic actual types, since it is
4160 -- unwelcome noise in that case in instantiations. We also
4161 -- generally suppress the message in instantiations, and also
4162 -- if it involves internal names.
4164 if Opt.List_Inherited_Aspects
4165 and then not Is_Generic_Actual_Type (Typ)
4166 and then Instantiation_Depth (Sloc (Typ)) = 0
4167 and then not Is_Internal_Name (Chars (T))
4168 and then not Is_Internal_Name (Chars (Typ))
4170 Error_Msg_Sloc := Sloc (Predicate_Function (T));
4171 Error_Msg_Node_2 := T;
4172 Error_Msg_N ("?info: & inherits predicate from & #", Typ);
4177 --------------------
4178 -- Add_Predicates --
4179 --------------------
4181 procedure Add_Predicates is
4186 procedure Replace_Type_Reference (N : Node_Id);
4187 -- Replace a single occurrence N of the subtype name with a reference
4188 -- to the formal of the predicate function. N can be an identifier
4189 -- referencing the subtype, or a selected component, representing an
4190 -- appropriately qualified occurrence of the subtype name.
4192 procedure Replace_Type_References is
4193 new Replace_Type_References_Generic (Replace_Type_Reference);
4194 -- Traverse an expression changing every occurrence of an identifier
4195 -- whose name matches the name of the subtype with a reference to
4196 -- the formal parameter of the predicate function.
4198 ----------------------------
4199 -- Replace_Type_Reference --
4200 ----------------------------
4202 procedure Replace_Type_Reference (N : Node_Id) is
4204 Rewrite (N, Make_Identifier (Loc, Object_Name));
4205 Set_Entity (N, Object_Entity);
4207 end Replace_Type_Reference;
4209 -- Start of processing for Add_Predicates
4212 Ritem := First_Rep_Item (Typ);
4213 while Present (Ritem) loop
4214 if Nkind (Ritem) = N_Pragma
4215 and then Pragma_Name (Ritem) = Name_Predicate
4217 if From_Dynamic_Predicate (Ritem) then
4218 Dynamic_Predicate_Present := True;
4219 elsif From_Static_Predicate (Ritem) then
4220 Static_Predicate_Present := Ritem;
4223 -- Acquire arguments
4225 Arg1 := First (Pragma_Argument_Associations (Ritem));
4226 Arg2 := Next (Arg1);
4228 Arg1 := Get_Pragma_Arg (Arg1);
4229 Arg2 := Get_Pragma_Arg (Arg2);
4231 -- See if this predicate pragma is for the current type or for
4232 -- its full view. A predicate on a private completion is placed
4233 -- on the partial view beause this is the visible entity that
4236 if Entity (Arg1) = Typ
4237 or else Full_View (Entity (Arg1)) = Typ
4240 -- We have a match, this entry is for our subtype
4242 -- We need to replace any occurrences of the name of the
4243 -- type with references to the object.
4245 Replace_Type_References (Arg2, Chars (Typ));
4247 -- If this predicate comes from an aspect, find the aspect
4248 -- specification, and replace the saved expression because
4249 -- we need the subtype references replaced for the calls to
4250 -- Preanalyze_Spec_Expressin in Check_Aspect_At_Freeze_Point
4251 -- and Check_Aspect_At_End_Of_Declarations.
4253 if From_Aspect_Specification (Ritem) then
4258 -- Loop to find corresponding aspect, note that this
4259 -- must be present given the pragma is marked delayed.
4261 Aitem := Next_Rep_Item (Ritem);
4263 if Nkind (Aitem) = N_Aspect_Specification
4264 and then Aspect_Rep_Item (Aitem) = Ritem
4267 (Identifier (Aitem), New_Copy_Tree (Arg2));
4271 Aitem := Next_Rep_Item (Aitem);
4276 -- Now we can add the expression
4279 Expr := Relocate_Node (Arg2);
4281 -- There already was a predicate, so add to it
4286 Left_Opnd => Relocate_Node (Expr),
4287 Right_Opnd => Relocate_Node (Arg2));
4292 Next_Rep_Item (Ritem);
4296 -- Start of processing for Build_Predicate_Function
4299 -- Initialize for construction of statement list
4303 -- Return if already built or if type does not have predicates
4305 if not Has_Predicates (Typ)
4306 or else Present (Predicate_Function (Typ))
4311 -- Add Predicates for the current type
4315 -- Add predicates for ancestor if present
4318 Atyp : constant Entity_Id := Nearest_Ancestor (Typ);
4320 if Present (Atyp) then
4325 -- If we have predicates, build the function
4327 if Present (Expr) then
4329 -- Build function declaration
4331 pragma Assert (Has_Predicates (Typ));
4333 Make_Defining_Identifier (Loc,
4334 Chars => New_External_Name (Chars (Typ), "Predicate"));
4335 Set_Has_Predicates (SId);
4336 Set_Predicate_Function (Typ, SId);
4339 Make_Function_Specification (Loc,
4340 Defining_Unit_Name => SId,
4341 Parameter_Specifications => New_List (
4342 Make_Parameter_Specification (Loc,
4343 Defining_Identifier => Object_Entity,
4344 Parameter_Type => New_Occurrence_Of (Typ, Loc))),
4345 Result_Definition =>
4346 New_Occurrence_Of (Standard_Boolean, Loc));
4348 FDecl := Make_Subprogram_Declaration (Loc, Specification => Spec);
4350 -- Build function body
4353 Make_Defining_Identifier (Loc,
4354 Chars => New_External_Name (Chars (Typ), "Predicate"));
4357 Make_Function_Specification (Loc,
4358 Defining_Unit_Name => SId,
4359 Parameter_Specifications => New_List (
4360 Make_Parameter_Specification (Loc,
4361 Defining_Identifier =>
4362 Make_Defining_Identifier (Loc, Object_Name),
4364 New_Occurrence_Of (Typ, Loc))),
4365 Result_Definition =>
4366 New_Occurrence_Of (Standard_Boolean, Loc));
4369 Make_Subprogram_Body (Loc,
4370 Specification => Spec,
4371 Declarations => Empty_List,
4372 Handled_Statement_Sequence =>
4373 Make_Handled_Sequence_Of_Statements (Loc,
4374 Statements => New_List (
4375 Make_Simple_Return_Statement (Loc,
4376 Expression => Expr))));
4378 -- Insert declaration before freeze node and body after
4380 Insert_Before_And_Analyze (N, FDecl);
4381 Insert_After_And_Analyze (N, FBody);
4383 -- Deal with static predicate case
4385 if Ekind_In (Typ, E_Enumeration_Subtype,
4386 E_Modular_Integer_Subtype,
4387 E_Signed_Integer_Subtype)
4388 and then Is_Static_Subtype (Typ)
4389 and then not Dynamic_Predicate_Present
4391 Build_Static_Predicate (Typ, Expr, Object_Name);
4393 if Present (Static_Predicate_Present)
4394 and No (Static_Predicate (Typ))
4397 ("expression does not have required form for "
4398 & "static predicate",
4399 Next (First (Pragma_Argument_Associations
4400 (Static_Predicate_Present))));
4404 end Build_Predicate_Function;
4406 ----------------------------
4407 -- Build_Static_Predicate --
4408 ----------------------------
4410 procedure Build_Static_Predicate
4415 Loc : constant Source_Ptr := Sloc (Expr);
4417 Non_Static : exception;
4418 -- Raised if something non-static is found
4420 Btyp : constant Entity_Id := Base_Type (Typ);
4422 BLo : constant Uint := Expr_Value (Type_Low_Bound (Btyp));
4423 BHi : constant Uint := Expr_Value (Type_High_Bound (Btyp));
4424 -- Low bound and high bound value of base type of Typ
4426 TLo : constant Uint := Expr_Value (Type_Low_Bound (Typ));
4427 THi : constant Uint := Expr_Value (Type_High_Bound (Typ));
4428 -- Low bound and high bound values of static subtype Typ
4433 -- One entry in a Rlist value, a single REnt (range entry) value
4434 -- denotes one range from Lo to Hi. To represent a single value
4435 -- range Lo = Hi = value.
4437 type RList is array (Nat range <>) of REnt;
4438 -- A list of ranges. The ranges are sorted in increasing order,
4439 -- and are disjoint (there is a gap of at least one value between
4440 -- each range in the table). A value is in the set of ranges in
4441 -- Rlist if it lies within one of these ranges
4443 False_Range : constant RList :=
4444 RList'(1 .. 0 => REnt'(No_Uint, No_Uint));
4445 -- An empty set of ranges represents a range list that can never be
4446 -- satisfied, since there are no ranges in which the value could lie,
4447 -- so it does not lie in any of them. False_Range is a canonical value
4448 -- for this empty set, but general processing should test for an Rlist
4449 -- with length zero (see Is_False predicate), since other null ranges
4450 -- may appear which must be treated as False.
4452 True_Range : constant RList := RList'(1 => REnt'(BLo, BHi));
4453 -- Range representing True, value must be in the base range
4455 function "and" (Left, Right : RList) return RList;
4456 -- And's together two range lists, returning a range list. This is
4457 -- a set intersection operation.
4459 function "or" (Left, Right : RList) return RList;
4460 -- Or's together two range lists, returning a range list. This is a
4461 -- set union operation.
4463 function "not" (Right : RList) return RList;
4464 -- Returns complement of a given range list, i.e. a range list
4465 -- representing all the values in TLo .. THi that are not in the
4466 -- input operand Right.
4468 function Build_Val (V : Uint) return Node_Id;
4469 -- Return an analyzed N_Identifier node referencing this value, suitable
4470 -- for use as an entry in the Static_Predicate list. This node is typed
4471 -- with the base type.
4473 function Build_Range (Lo, Hi : Uint) return Node_Id;
4474 -- Return an analyzed N_Range node referencing this range, suitable
4475 -- for use as an entry in the Static_Predicate list. This node is typed
4476 -- with the base type.
4478 function Get_RList (Exp : Node_Id) return RList;
4479 -- This is a recursive routine that converts the given expression into
4480 -- a list of ranges, suitable for use in building the static predicate.
4482 function Is_False (R : RList) return Boolean;
4483 pragma Inline (Is_False);
4484 -- Returns True if the given range list is empty, and thus represents
4485 -- a False list of ranges that can never be satisfied.
4487 function Is_True (R : RList) return Boolean;
4488 -- Returns True if R trivially represents the True predicate by having
4489 -- a single range from BLo to BHi.
4491 function Is_Type_Ref (N : Node_Id) return Boolean;
4492 pragma Inline (Is_Type_Ref);
4493 -- Returns if True if N is a reference to the type for the predicate in
4494 -- the expression (i.e. if it is an identifier whose Chars field matches
4495 -- the Nam given in the call).
4497 function Lo_Val (N : Node_Id) return Uint;
4498 -- Given static expression or static range from a Static_Predicate list,
4499 -- gets expression value or low bound of range.
4501 function Hi_Val (N : Node_Id) return Uint;
4502 -- Given static expression or static range from a Static_Predicate list,
4503 -- gets expression value of high bound of range.
4505 function Membership_Entry (N : Node_Id) return RList;
4506 -- Given a single membership entry (range, value, or subtype), returns
4507 -- the corresponding range list. Raises Static_Error if not static.
4509 function Membership_Entries (N : Node_Id) return RList;
4510 -- Given an element on an alternatives list of a membership operation,
4511 -- returns the range list corresponding to this entry and all following
4512 -- entries (i.e. returns the "or" of this list of values).
4514 function Stat_Pred (Typ : Entity_Id) return RList;
4515 -- Given a type, if it has a static predicate, then return the predicate
4516 -- as a range list, otherwise raise Non_Static.
4522 function "and" (Left, Right : RList) return RList is
4524 -- First range of result
4526 SLeft : Nat := Left'First;
4527 -- Start of rest of left entries
4529 SRight : Nat := Right'First;
4530 -- Start of rest of right entries
4533 -- If either range is True, return the other
4535 if Is_True (Left) then
4537 elsif Is_True (Right) then
4541 -- If either range is False, return False
4543 if Is_False (Left) or else Is_False (Right) then
4547 -- Loop to remove entries at start that are disjoint, and thus
4548 -- just get discarded from the result entirely.
4551 -- If no operands left in either operand, result is false
4553 if SLeft > Left'Last or else SRight > Right'Last then
4556 -- Discard first left operand entry if disjoint with right
4558 elsif Left (SLeft).Hi < Right (SRight).Lo then
4561 -- Discard first right operand entry if disjoint with left
4563 elsif Right (SRight).Hi < Left (SLeft).Lo then
4564 SRight := SRight + 1;
4566 -- Otherwise we have an overlapping entry
4573 -- Now we have two non-null operands, and first entries overlap.
4574 -- The first entry in the result will be the overlapping part of
4575 -- these two entries.
4577 FEnt := REnt'(Lo => UI_Max (Left (SLeft).Lo, Right (SRight).Lo),
4578 Hi => UI_Min (Left (SLeft).Hi, Right (SRight).Hi));
4580 -- Now we can remove the entry that ended at a lower value, since
4581 -- its contribution is entirely contained in Fent.
4583 if Left (SLeft).Hi <= Right (SRight).Hi then
4586 SRight := SRight + 1;
4589 -- Compute result by concatenating this first entry with the "and"
4590 -- of the remaining parts of the left and right operands. Note that
4591 -- if either of these is empty, "and" will yield empty, so that we
4592 -- will end up with just Fent, which is what we want in that case.
4595 FEnt & (Left (SLeft .. Left'Last) and Right (SRight .. Right'Last));
4602 function "not" (Right : RList) return RList is
4604 -- Return True if False range
4606 if Is_False (Right) then
4610 -- Return False if True range
4612 if Is_True (Right) then
4616 -- Here if not trivial case
4619 Result : RList (1 .. Right'Length + 1);
4620 -- May need one more entry for gap at beginning and end
4623 -- Number of entries stored in Result
4628 if Right (Right'First).Lo > TLo then
4630 Result (Count) := REnt'(TLo, Right (Right'First).Lo - 1);
4633 -- Gaps between ranges
4635 for J in Right'First .. Right'Last - 1 loop
4638 REnt'(Right (J).Hi + 1, Right (J + 1).Lo - 1);
4643 if Right (Right'Last).Hi < THi then
4645 Result (Count) := REnt'(Right (Right'Last).Hi + 1, THi);
4648 return Result (1 .. Count);
4656 function "or" (Left, Right : RList) return RList is
4658 -- First range of result
4660 SLeft : Nat := Left'First;
4661 -- Start of rest of left entries
4663 SRight : Nat := Right'First;
4664 -- Start of rest of right entries
4667 -- If either range is True, return True
4669 if Is_True (Left) or else Is_True (Right) then
4673 -- If either range is False (empty), return the other
4675 if Is_False (Left) then
4677 elsif Is_False (Right) then
4681 -- Initialize result first entry from left or right operand
4682 -- depending on which starts with the lower range.
4684 if Left (SLeft).Lo < Right (SRight).Lo then
4685 FEnt := Left (SLeft);
4688 FEnt := Right (SRight);
4689 SRight := SRight + 1;
4692 -- This loop eats ranges from left and right operands that
4693 -- are contiguous with the first range we are gathering.
4696 -- Eat first entry in left operand if contiguous or
4697 -- overlapped by gathered first operand of result.
4699 if SLeft <= Left'Last
4700 and then Left (SLeft).Lo <= FEnt.Hi + 1
4702 FEnt.Hi := UI_Max (FEnt.Hi, Left (SLeft).Hi);
4705 -- Eat first entry in right operand if contiguous or
4706 -- overlapped by gathered right operand of result.
4708 elsif SRight <= Right'Last
4709 and then Right (SRight).Lo <= FEnt.Hi + 1
4711 FEnt.Hi := UI_Max (FEnt.Hi, Right (SRight).Hi);
4712 SRight := SRight + 1;
4714 -- All done if no more entries to eat!
4721 -- Obtain result as the first entry we just computed, concatenated
4722 -- to the "or" of the remaining results (if one operand is empty,
4723 -- this will just concatenate with the other
4726 FEnt & (Left (SLeft .. Left'Last) or Right (SRight .. Right'Last));
4733 function Build_Range (Lo, Hi : Uint) return Node_Id is
4737 return Build_Val (Hi);
4741 Low_Bound => Build_Val (Lo),
4742 High_Bound => Build_Val (Hi));
4743 Set_Etype (Result, Btyp);
4744 Set_Analyzed (Result);
4753 function Build_Val (V : Uint) return Node_Id is
4757 if Is_Enumeration_Type (Typ) then
4758 Result := Get_Enum_Lit_From_Pos (Typ, V, Loc);
4760 Result := Make_Integer_Literal (Loc, V);
4763 Set_Etype (Result, Btyp);
4764 Set_Is_Static_Expression (Result);
4765 Set_Analyzed (Result);
4773 function Get_RList (Exp : Node_Id) return RList is
4778 -- Static expression can only be true or false
4780 if Is_OK_Static_Expression (Exp) then
4784 if Expr_Value (Exp) = 0 then
4791 -- Otherwise test node type
4799 when N_Op_And | N_And_Then =>
4800 return Get_RList (Left_Opnd (Exp))
4802 Get_RList (Right_Opnd (Exp));
4806 when N_Op_Or | N_Or_Else =>
4807 return Get_RList (Left_Opnd (Exp))
4809 Get_RList (Right_Opnd (Exp));
4814 return not Get_RList (Right_Opnd (Exp));
4816 -- Comparisons of type with static value
4818 when N_Op_Compare =>
4819 -- Type is left operand
4821 if Is_Type_Ref (Left_Opnd (Exp))
4822 and then Is_OK_Static_Expression (Right_Opnd (Exp))
4824 Val := Expr_Value (Right_Opnd (Exp));
4826 -- Typ is right operand
4828 elsif Is_Type_Ref (Right_Opnd (Exp))
4829 and then Is_OK_Static_Expression (Left_Opnd (Exp))
4831 Val := Expr_Value (Left_Opnd (Exp));
4833 -- Invert sense of comparison
4836 when N_Op_Gt => Op := N_Op_Lt;
4837 when N_Op_Lt => Op := N_Op_Gt;
4838 when N_Op_Ge => Op := N_Op_Le;
4839 when N_Op_Le => Op := N_Op_Ge;
4840 when others => null;
4843 -- Other cases are non-static
4849 -- Construct range according to comparison operation
4853 return RList'(1 => REnt'(Val, Val));
4856 return RList'(1 => REnt'(Val, BHi));
4859 return RList'(1 => REnt'(Val + 1, BHi));
4862 return RList'(1 => REnt'(BLo, Val));
4865 return RList'(1 => REnt'(BLo, Val - 1));
4868 return RList'(REnt'(BLo, Val - 1),
4869 REnt'(Val + 1, BHi));
4872 raise Program_Error;
4878 if not Is_Type_Ref (Left_Opnd (Exp)) then
4882 if Present (Right_Opnd (Exp)) then
4883 return Membership_Entry (Right_Opnd (Exp));
4885 return Membership_Entries (First (Alternatives (Exp)));
4888 -- Negative membership (NOT IN)
4891 if not Is_Type_Ref (Left_Opnd (Exp)) then
4895 if Present (Right_Opnd (Exp)) then
4896 return not Membership_Entry (Right_Opnd (Exp));
4898 return not Membership_Entries (First (Alternatives (Exp)));
4901 -- Function call, may be call to static predicate
4903 when N_Function_Call =>
4904 if Is_Entity_Name (Name (Exp)) then
4906 Ent : constant Entity_Id := Entity (Name (Exp));
4908 if Has_Predicates (Ent) then
4909 return Stat_Pred (Etype (First_Formal (Ent)));
4914 -- Other function call cases are non-static
4918 -- Qualified expression, dig out the expression
4920 when N_Qualified_Expression =>
4921 return Get_RList (Expression (Exp));
4926 return (Get_RList (Left_Opnd (Exp))
4927 and not Get_RList (Right_Opnd (Exp)))
4928 or (Get_RList (Right_Opnd (Exp))
4929 and not Get_RList (Left_Opnd (Exp)));
4931 -- Any other node type is non-static
4942 function Hi_Val (N : Node_Id) return Uint is
4944 if Is_Static_Expression (N) then
4945 return Expr_Value (N);
4947 pragma Assert (Nkind (N) = N_Range);
4948 return Expr_Value (High_Bound (N));
4956 function Is_False (R : RList) return Boolean is
4958 return R'Length = 0;
4965 function Is_True (R : RList) return Boolean is
4968 and then R (R'First).Lo = BLo
4969 and then R (R'First).Hi = BHi;
4976 function Is_Type_Ref (N : Node_Id) return Boolean is
4978 return Nkind (N) = N_Identifier and then Chars (N) = Nam;
4985 function Lo_Val (N : Node_Id) return Uint is
4987 if Is_Static_Expression (N) then
4988 return Expr_Value (N);
4990 pragma Assert (Nkind (N) = N_Range);
4991 return Expr_Value (Low_Bound (N));
4995 ------------------------
4996 -- Membership_Entries --
4997 ------------------------
4999 function Membership_Entries (N : Node_Id) return RList is
5001 if No (Next (N)) then
5002 return Membership_Entry (N);
5004 return Membership_Entry (N) or Membership_Entries (Next (N));
5006 end Membership_Entries;
5008 ----------------------
5009 -- Membership_Entry --
5010 ----------------------
5012 function Membership_Entry (N : Node_Id) return RList is
5020 if Nkind (N) = N_Range then
5021 if not Is_Static_Expression (Low_Bound (N))
5023 not Is_Static_Expression (High_Bound (N))
5027 SLo := Expr_Value (Low_Bound (N));
5028 SHi := Expr_Value (High_Bound (N));
5029 return RList'(1 => REnt'(SLo, SHi));
5032 -- Static expression case
5034 elsif Is_Static_Expression (N) then
5035 Val := Expr_Value (N);
5036 return RList'(1 => REnt'(Val, Val));
5038 -- Identifier (other than static expression) case
5040 else pragma Assert (Nkind (N) = N_Identifier);
5044 if Is_Type (Entity (N)) then
5046 -- If type has predicates, process them
5048 if Has_Predicates (Entity (N)) then
5049 return Stat_Pred (Entity (N));
5051 -- For static subtype without predicates, get range
5053 elsif Is_Static_Subtype (Entity (N)) then
5054 SLo := Expr_Value (Type_Low_Bound (Entity (N)));
5055 SHi := Expr_Value (Type_High_Bound (Entity (N)));
5056 return RList'(1 => REnt'(SLo, SHi));
5058 -- Any other type makes us non-static
5064 -- Any other kind of identifier in predicate (e.g. a non-static
5065 -- expression value) means this is not a static predicate.
5071 end Membership_Entry;
5077 function Stat_Pred (Typ : Entity_Id) return RList is
5079 -- Not static if type does not have static predicates
5081 if not Has_Predicates (Typ)
5082 or else No (Static_Predicate (Typ))
5087 -- Otherwise we convert the predicate list to a range list
5090 Result : RList (1 .. List_Length (Static_Predicate (Typ)));
5094 P := First (Static_Predicate (Typ));
5095 for J in Result'Range loop
5096 Result (J) := REnt'(Lo_Val (P), Hi_Val (P));
5104 -- Start of processing for Build_Static_Predicate
5107 -- Now analyze the expression to see if it is a static predicate
5110 Ranges : constant RList := Get_RList (Expr);
5111 -- Range list from expression if it is static
5116 -- Convert range list into a form for the static predicate. In the
5117 -- Ranges array, we just have raw ranges, these must be converted
5118 -- to properly typed and analyzed static expressions or range nodes.
5120 -- Note: here we limit ranges to the ranges of the subtype, so that
5121 -- a predicate is always false for values outside the subtype. That
5122 -- seems fine, such values are invalid anyway, and considering them
5123 -- to fail the predicate seems allowed and friendly, and furthermore
5124 -- simplifies processing for case statements and loops.
5128 for J in Ranges'Range loop
5130 Lo : Uint := Ranges (J).Lo;
5131 Hi : Uint := Ranges (J).Hi;
5134 -- Ignore completely out of range entry
5136 if Hi < TLo or else Lo > THi then
5139 -- Otherwise process entry
5142 -- Adjust out of range value to subtype range
5152 -- Convert range into required form
5155 Append_To (Plist, Build_Val (Lo));
5157 Append_To (Plist, Build_Range (Lo, Hi));
5163 -- Processing was successful and all entries were static, so now we
5164 -- can store the result as the predicate list.
5166 Set_Static_Predicate (Typ, Plist);
5168 -- The processing for static predicates put the expression into
5169 -- canonical form as a series of ranges. It also eliminated
5170 -- duplicates and collapsed and combined ranges. We might as well
5171 -- replace the alternatives list of the right operand of the
5172 -- membership test with the static predicate list, which will
5173 -- usually be more efficient.
5176 New_Alts : constant List_Id := New_List;
5181 Old_Node := First (Plist);
5182 while Present (Old_Node) loop
5183 New_Node := New_Copy (Old_Node);
5185 if Nkind (New_Node) = N_Range then
5186 Set_Low_Bound (New_Node, New_Copy (Low_Bound (Old_Node)));
5187 Set_High_Bound (New_Node, New_Copy (High_Bound (Old_Node)));
5190 Append_To (New_Alts, New_Node);
5194 -- If empty list, replace by False
5196 if Is_Empty_List (New_Alts) then
5197 Rewrite (Expr, New_Occurrence_Of (Standard_False, Loc));
5199 -- Else replace by set membership test
5204 Left_Opnd => Make_Identifier (Loc, Nam),
5205 Right_Opnd => Empty,
5206 Alternatives => New_Alts));
5208 -- Resolve new expression in function context
5210 Install_Formals (Predicate_Function (Typ));
5211 Push_Scope (Predicate_Function (Typ));
5212 Analyze_And_Resolve (Expr, Standard_Boolean);
5218 -- If non-static, return doing nothing
5223 end Build_Static_Predicate;
5225 -----------------------------------------
5226 -- Check_Aspect_At_End_Of_Declarations --
5227 -----------------------------------------
5229 procedure Check_Aspect_At_End_Of_Declarations (ASN : Node_Id) is
5230 Ent : constant Entity_Id := Entity (ASN);
5231 Ident : constant Node_Id := Identifier (ASN);
5233 Freeze_Expr : constant Node_Id := Expression (ASN);
5234 -- Preanalyzed expression from call to Check_Aspect_At_Freeze_Point
5236 End_Decl_Expr : constant Node_Id := Entity (Ident);
5237 -- Expression to be analyzed at end of declarations
5239 T : constant Entity_Id := Etype (Freeze_Expr);
5240 -- Type required for preanalyze call
5242 A_Id : constant Aspect_Id := Get_Aspect_Id (Chars (Ident));
5245 -- Set False if error
5247 -- On entry to this procedure, Entity (Ident) contains a copy of the
5248 -- original expression from the aspect, saved for this purpose, and
5249 -- but Expression (Ident) is a preanalyzed copy of the expression,
5250 -- preanalyzed just after the freeze point.
5253 -- Case of stream attributes, just have to compare entities
5255 if A_Id = Aspect_Input or else
5256 A_Id = Aspect_Output or else
5257 A_Id = Aspect_Read or else
5260 Analyze (End_Decl_Expr);
5261 Err := Entity (End_Decl_Expr) /= Entity (Freeze_Expr);
5266 Preanalyze_Spec_Expression (End_Decl_Expr, T);
5267 Err := not Fully_Conformant_Expressions (End_Decl_Expr, Freeze_Expr);
5270 -- Output error message if error
5274 ("visibility of aspect for& changes after freeze point",
5277 ("?info: & is frozen here, aspects evaluated at this point",
5278 Freeze_Node (Ent), Ent);
5280 end Check_Aspect_At_End_Of_Declarations;
5282 ----------------------------------
5283 -- Check_Aspect_At_Freeze_Point --
5284 ----------------------------------
5286 procedure Check_Aspect_At_Freeze_Point (ASN : Node_Id) is
5287 Ident : constant Node_Id := Identifier (ASN);
5288 -- Identifier (use Entity field to save expression)
5291 -- Type required for preanalyze call
5293 A_Id : constant Aspect_Id := Get_Aspect_Id (Chars (Ident));
5296 -- On entry to this procedure, Entity (Ident) contains a copy of the
5297 -- original expression from the aspect, saved for this purpose.
5299 -- On exit from this procedure Entity (Ident) is unchanged, still
5300 -- containing that copy, but Expression (Ident) is a preanalyzed copy
5301 -- of the expression, preanalyzed just after the freeze point.
5303 -- Make a copy of the expression to be preanalyed
5305 Set_Expression (ASN, New_Copy_Tree (Entity (Ident)));
5307 -- Find type for preanalyze call
5311 -- No_Aspect should be impossible
5314 raise Program_Error;
5316 -- Library unit aspects should be impossible (never delayed)
5318 when Library_Unit_Aspects =>
5319 raise Program_Error;
5321 -- Aspects taking an optional boolean argument. Should be impossible
5322 -- since these are never delayed.
5324 when Boolean_Aspects =>
5325 raise Program_Error;
5327 -- Default_Value is resolved with the type entity in question
5329 when Aspect_Default_Value =>
5332 -- Default_Component_Value is resolved with the component type
5334 when Aspect_Default_Component_Value =>
5335 T := Component_Type (Entity (ASN));
5337 -- Aspects corresponding to attribute definition clauses
5339 when Aspect_Address =>
5340 T := RTE (RE_Address);
5342 when Aspect_Bit_Order =>
5343 T := RTE (RE_Bit_Order);
5345 when Aspect_External_Tag =>
5346 T := Standard_String;
5348 when Aspect_Storage_Pool =>
5349 T := Class_Wide_Type (RTE (RE_Root_Storage_Pool));
5353 Aspect_Component_Size |
5354 Aspect_Machine_Radix |
5355 Aspect_Object_Size |
5357 Aspect_Storage_Size |
5358 Aspect_Stream_Size |
5359 Aspect_Value_Size =>
5362 -- Stream attribute. Special case, the expression is just an entity
5363 -- that does not need any resolution, so just analyze.
5369 Analyze (Expression (ASN));
5372 -- Suppress/Unsupress/Warnings should never be delayed
5374 when Aspect_Suppress |
5377 raise Program_Error;
5379 -- Pre/Post/Invariant/Predicate take boolean expressions
5381 when Aspect_Dynamic_Predicate |
5384 Aspect_Precondition |
5386 Aspect_Postcondition |
5388 Aspect_Static_Predicate |
5389 Aspect_Type_Invariant =>
5390 T := Standard_Boolean;
5393 -- Do the preanalyze call
5395 Preanalyze_Spec_Expression (Expression (ASN), T);
5396 end Check_Aspect_At_Freeze_Point;
5398 -----------------------------------
5399 -- Check_Constant_Address_Clause --
5400 -----------------------------------
5402 procedure Check_Constant_Address_Clause
5406 procedure Check_At_Constant_Address (Nod : Node_Id);
5407 -- Checks that the given node N represents a name whose 'Address is
5408 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
5409 -- address value is the same at the point of declaration of U_Ent and at
5410 -- the time of elaboration of the address clause.
5412 procedure Check_Expr_Constants (Nod : Node_Id);
5413 -- Checks that Nod meets the requirements for a constant address clause
5414 -- in the sense of the enclosing procedure.
5416 procedure Check_List_Constants (Lst : List_Id);
5417 -- Check that all elements of list Lst meet the requirements for a
5418 -- constant address clause in the sense of the enclosing procedure.
5420 -------------------------------
5421 -- Check_At_Constant_Address --
5422 -------------------------------
5424 procedure Check_At_Constant_Address (Nod : Node_Id) is
5426 if Is_Entity_Name (Nod) then
5427 if Present (Address_Clause (Entity ((Nod)))) then
5429 ("invalid address clause for initialized object &!",
5432 ("address for& cannot" &
5433 " depend on another address clause! (RM 13.1(22))!",
5436 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
5437 and then Sloc (U_Ent) < Sloc (Entity (Nod))
5440 ("invalid address clause for initialized object &!",
5442 Error_Msg_Node_2 := U_Ent;
5444 ("\& must be defined before & (RM 13.1(22))!",
5448 elsif Nkind (Nod) = N_Selected_Component then
5450 T : constant Entity_Id := Etype (Prefix (Nod));
5453 if (Is_Record_Type (T)
5454 and then Has_Discriminants (T))
5457 and then Is_Record_Type (Designated_Type (T))
5458 and then Has_Discriminants (Designated_Type (T)))
5461 ("invalid address clause for initialized object &!",
5464 ("\address cannot depend on component" &
5465 " of discriminated record (RM 13.1(22))!",
5468 Check_At_Constant_Address (Prefix (Nod));
5472 elsif Nkind (Nod) = N_Indexed_Component then
5473 Check_At_Constant_Address (Prefix (Nod));
5474 Check_List_Constants (Expressions (Nod));
5477 Check_Expr_Constants (Nod);
5479 end Check_At_Constant_Address;
5481 --------------------------
5482 -- Check_Expr_Constants --
5483 --------------------------
5485 procedure Check_Expr_Constants (Nod : Node_Id) is
5486 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
5487 Ent : Entity_Id := Empty;
5490 if Nkind (Nod) in N_Has_Etype
5491 and then Etype (Nod) = Any_Type
5497 when N_Empty | N_Error =>
5500 when N_Identifier | N_Expanded_Name =>
5501 Ent := Entity (Nod);
5503 -- We need to look at the original node if it is different
5504 -- from the node, since we may have rewritten things and
5505 -- substituted an identifier representing the rewrite.
5507 if Original_Node (Nod) /= Nod then
5508 Check_Expr_Constants (Original_Node (Nod));
5510 -- If the node is an object declaration without initial
5511 -- value, some code has been expanded, and the expression
5512 -- is not constant, even if the constituents might be
5513 -- acceptable, as in A'Address + offset.
5515 if Ekind (Ent) = E_Variable
5517 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
5519 No (Expression (Declaration_Node (Ent)))
5522 ("invalid address clause for initialized object &!",
5525 -- If entity is constant, it may be the result of expanding
5526 -- a check. We must verify that its declaration appears
5527 -- before the object in question, else we also reject the
5530 elsif Ekind (Ent) = E_Constant
5531 and then In_Same_Source_Unit (Ent, U_Ent)
5532 and then Sloc (Ent) > Loc_U_Ent
5535 ("invalid address clause for initialized object &!",
5542 -- Otherwise look at the identifier and see if it is OK
5544 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
5545 or else Is_Type (Ent)
5550 Ekind (Ent) = E_Constant
5552 Ekind (Ent) = E_In_Parameter
5554 -- This is the case where we must have Ent defined before
5555 -- U_Ent. Clearly if they are in different units this
5556 -- requirement is met since the unit containing Ent is
5557 -- already processed.
5559 if not In_Same_Source_Unit (Ent, U_Ent) then
5562 -- Otherwise location of Ent must be before the location
5563 -- of U_Ent, that's what prior defined means.
5565 elsif Sloc (Ent) < Loc_U_Ent then
5570 ("invalid address clause for initialized object &!",
5572 Error_Msg_Node_2 := U_Ent;
5574 ("\& must be defined before & (RM 13.1(22))!",
5578 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
5579 Check_Expr_Constants (Original_Node (Nod));
5583 ("invalid address clause for initialized object &!",
5586 if Comes_From_Source (Ent) then
5588 ("\reference to variable& not allowed"
5589 & " (RM 13.1(22))!", Nod, Ent);
5592 ("non-static expression not allowed"
5593 & " (RM 13.1(22))!", Nod);
5597 when N_Integer_Literal =>
5599 -- If this is a rewritten unchecked conversion, in a system
5600 -- where Address is an integer type, always use the base type
5601 -- for a literal value. This is user-friendly and prevents
5602 -- order-of-elaboration issues with instances of unchecked
5605 if Nkind (Original_Node (Nod)) = N_Function_Call then
5606 Set_Etype (Nod, Base_Type (Etype (Nod)));
5609 when N_Real_Literal |
5611 N_Character_Literal =>
5615 Check_Expr_Constants (Low_Bound (Nod));
5616 Check_Expr_Constants (High_Bound (Nod));
5618 when N_Explicit_Dereference =>
5619 Check_Expr_Constants (Prefix (Nod));
5621 when N_Indexed_Component =>
5622 Check_Expr_Constants (Prefix (Nod));
5623 Check_List_Constants (Expressions (Nod));
5626 Check_Expr_Constants (Prefix (Nod));
5627 Check_Expr_Constants (Discrete_Range (Nod));
5629 when N_Selected_Component =>
5630 Check_Expr_Constants (Prefix (Nod));
5632 when N_Attribute_Reference =>
5633 if Attribute_Name (Nod) = Name_Address
5635 Attribute_Name (Nod) = Name_Access
5637 Attribute_Name (Nod) = Name_Unchecked_Access
5639 Attribute_Name (Nod) = Name_Unrestricted_Access
5641 Check_At_Constant_Address (Prefix (Nod));
5644 Check_Expr_Constants (Prefix (Nod));
5645 Check_List_Constants (Expressions (Nod));
5649 Check_List_Constants (Component_Associations (Nod));
5650 Check_List_Constants (Expressions (Nod));
5652 when N_Component_Association =>
5653 Check_Expr_Constants (Expression (Nod));
5655 when N_Extension_Aggregate =>
5656 Check_Expr_Constants (Ancestor_Part (Nod));
5657 Check_List_Constants (Component_Associations (Nod));
5658 Check_List_Constants (Expressions (Nod));
5663 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
5664 Check_Expr_Constants (Left_Opnd (Nod));
5665 Check_Expr_Constants (Right_Opnd (Nod));
5668 Check_Expr_Constants (Right_Opnd (Nod));
5670 when N_Type_Conversion |
5671 N_Qualified_Expression |
5673 Check_Expr_Constants (Expression (Nod));
5675 when N_Unchecked_Type_Conversion =>
5676 Check_Expr_Constants (Expression (Nod));
5678 -- If this is a rewritten unchecked conversion, subtypes in
5679 -- this node are those created within the instance. To avoid
5680 -- order of elaboration issues, replace them with their base
5681 -- types. Note that address clauses can cause order of
5682 -- elaboration problems because they are elaborated by the
5683 -- back-end at the point of definition, and may mention
5684 -- entities declared in between (as long as everything is
5685 -- static). It is user-friendly to allow unchecked conversions
5688 if Nkind (Original_Node (Nod)) = N_Function_Call then
5689 Set_Etype (Expression (Nod),
5690 Base_Type (Etype (Expression (Nod))));
5691 Set_Etype (Nod, Base_Type (Etype (Nod)));
5694 when N_Function_Call =>
5695 if not Is_Pure (Entity (Name (Nod))) then
5697 ("invalid address clause for initialized object &!",
5701 ("\function & is not pure (RM 13.1(22))!",
5702 Nod, Entity (Name (Nod)));
5705 Check_List_Constants (Parameter_Associations (Nod));
5708 when N_Parameter_Association =>
5709 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
5713 ("invalid address clause for initialized object &!",
5716 ("\must be constant defined before& (RM 13.1(22))!",
5719 end Check_Expr_Constants;
5721 --------------------------
5722 -- Check_List_Constants --
5723 --------------------------
5725 procedure Check_List_Constants (Lst : List_Id) is
5729 if Present (Lst) then
5730 Nod1 := First (Lst);
5731 while Present (Nod1) loop
5732 Check_Expr_Constants (Nod1);
5736 end Check_List_Constants;
5738 -- Start of processing for Check_Constant_Address_Clause
5741 -- If rep_clauses are to be ignored, no need for legality checks. In
5742 -- particular, no need to pester user about rep clauses that violate
5743 -- the rule on constant addresses, given that these clauses will be
5744 -- removed by Freeze before they reach the back end.
5746 if not Ignore_Rep_Clauses then
5747 Check_Expr_Constants (Expr);
5749 end Check_Constant_Address_Clause;
5751 ----------------------------------------
5752 -- Check_Record_Representation_Clause --
5753 ----------------------------------------
5755 procedure Check_Record_Representation_Clause (N : Node_Id) is
5756 Loc : constant Source_Ptr := Sloc (N);
5757 Ident : constant Node_Id := Identifier (N);
5758 Rectype : Entity_Id;
5763 Hbit : Uint := Uint_0;
5767 Max_Bit_So_Far : Uint;
5768 -- Records the maximum bit position so far. If all field positions
5769 -- are monotonically increasing, then we can skip the circuit for
5770 -- checking for overlap, since no overlap is possible.
5772 Tagged_Parent : Entity_Id := Empty;
5773 -- This is set in the case of a derived tagged type for which we have
5774 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
5775 -- positioned by record representation clauses). In this case we must
5776 -- check for overlap between components of this tagged type, and the
5777 -- components of its parent. Tagged_Parent will point to this parent
5778 -- type. For all other cases Tagged_Parent is left set to Empty.
5780 Parent_Last_Bit : Uint;
5781 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
5782 -- last bit position for any field in the parent type. We only need to
5783 -- check overlap for fields starting below this point.
5785 Overlap_Check_Required : Boolean;
5786 -- Used to keep track of whether or not an overlap check is required
5788 Overlap_Detected : Boolean := False;
5789 -- Set True if an overlap is detected
5791 Ccount : Natural := 0;
5792 -- Number of component clauses in record rep clause
5794 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
5795 -- Given two entities for record components or discriminants, checks
5796 -- if they have overlapping component clauses and issues errors if so.
5798 procedure Find_Component;
5799 -- Finds component entity corresponding to current component clause (in
5800 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
5801 -- start/stop bits for the field. If there is no matching component or
5802 -- if the matching component does not have a component clause, then
5803 -- that's an error and Comp is set to Empty, but no error message is
5804 -- issued, since the message was already given. Comp is also set to
5805 -- Empty if the current "component clause" is in fact a pragma.
5807 -----------------------------
5808 -- Check_Component_Overlap --
5809 -----------------------------
5811 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
5812 CC1 : constant Node_Id := Component_Clause (C1_Ent);
5813 CC2 : constant Node_Id := Component_Clause (C2_Ent);
5816 if Present (CC1) and then Present (CC2) then
5818 -- Exclude odd case where we have two tag fields in the same
5819 -- record, both at location zero. This seems a bit strange, but
5820 -- it seems to happen in some circumstances, perhaps on an error.
5822 if Chars (C1_Ent) = Name_uTag
5824 Chars (C2_Ent) = Name_uTag
5829 -- Here we check if the two fields overlap
5832 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
5833 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
5834 E1 : constant Uint := S1 + Esize (C1_Ent);
5835 E2 : constant Uint := S2 + Esize (C2_Ent);
5838 if E2 <= S1 or else E1 <= S2 then
5841 Error_Msg_Node_2 := Component_Name (CC2);
5842 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
5843 Error_Msg_Node_1 := Component_Name (CC1);
5845 ("component& overlaps & #", Component_Name (CC1));
5846 Overlap_Detected := True;
5850 end Check_Component_Overlap;
5852 --------------------
5853 -- Find_Component --
5854 --------------------
5856 procedure Find_Component is
5858 procedure Search_Component (R : Entity_Id);
5859 -- Search components of R for a match. If found, Comp is set.
5861 ----------------------
5862 -- Search_Component --
5863 ----------------------
5865 procedure Search_Component (R : Entity_Id) is
5867 Comp := First_Component_Or_Discriminant (R);
5868 while Present (Comp) loop
5870 -- Ignore error of attribute name for component name (we
5871 -- already gave an error message for this, so no need to
5874 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
5877 exit when Chars (Comp) = Chars (Component_Name (CC));
5880 Next_Component_Or_Discriminant (Comp);
5882 end Search_Component;
5884 -- Start of processing for Find_Component
5887 -- Return with Comp set to Empty if we have a pragma
5889 if Nkind (CC) = N_Pragma then
5894 -- Search current record for matching component
5896 Search_Component (Rectype);
5898 -- If not found, maybe component of base type that is absent from
5899 -- statically constrained first subtype.
5902 Search_Component (Base_Type (Rectype));
5905 -- If no component, or the component does not reference the component
5906 -- clause in question, then there was some previous error for which
5907 -- we already gave a message, so just return with Comp Empty.
5910 or else Component_Clause (Comp) /= CC
5914 -- Normal case where we have a component clause
5917 Fbit := Component_Bit_Offset (Comp);
5918 Lbit := Fbit + Esize (Comp) - 1;
5922 -- Start of processing for Check_Record_Representation_Clause
5926 Rectype := Entity (Ident);
5928 if Rectype = Any_Type then
5931 Rectype := Underlying_Type (Rectype);
5934 -- See if we have a fully repped derived tagged type
5937 PS : constant Entity_Id := Parent_Subtype (Rectype);
5940 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
5941 Tagged_Parent := PS;
5943 -- Find maximum bit of any component of the parent type
5945 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
5946 Pcomp := First_Entity (Tagged_Parent);
5947 while Present (Pcomp) loop
5948 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
5949 if Component_Bit_Offset (Pcomp) /= No_Uint
5950 and then Known_Static_Esize (Pcomp)
5955 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
5958 Next_Entity (Pcomp);
5964 -- All done if no component clauses
5966 CC := First (Component_Clauses (N));
5972 -- If a tag is present, then create a component clause that places it
5973 -- at the start of the record (otherwise gigi may place it after other
5974 -- fields that have rep clauses).
5976 Fent := First_Entity (Rectype);
5978 if Nkind (Fent) = N_Defining_Identifier
5979 and then Chars (Fent) = Name_uTag
5981 Set_Component_Bit_Offset (Fent, Uint_0);
5982 Set_Normalized_Position (Fent, Uint_0);
5983 Set_Normalized_First_Bit (Fent, Uint_0);
5984 Set_Normalized_Position_Max (Fent, Uint_0);
5985 Init_Esize (Fent, System_Address_Size);
5987 Set_Component_Clause (Fent,
5988 Make_Component_Clause (Loc,
5989 Component_Name => Make_Identifier (Loc, Name_uTag),
5991 Position => Make_Integer_Literal (Loc, Uint_0),
5992 First_Bit => Make_Integer_Literal (Loc, Uint_0),
5994 Make_Integer_Literal (Loc,
5995 UI_From_Int (System_Address_Size))));
5997 Ccount := Ccount + 1;
6000 Max_Bit_So_Far := Uint_Minus_1;
6001 Overlap_Check_Required := False;
6003 -- Process the component clauses
6005 while Present (CC) loop
6008 if Present (Comp) then
6009 Ccount := Ccount + 1;
6011 -- We need a full overlap check if record positions non-monotonic
6013 if Fbit <= Max_Bit_So_Far then
6014 Overlap_Check_Required := True;
6017 Max_Bit_So_Far := Lbit;
6019 -- Check bit position out of range of specified size
6021 if Has_Size_Clause (Rectype)
6022 and then RM_Size (Rectype) <= Lbit
6025 ("bit number out of range of specified size",
6028 -- Check for overlap with tag field
6031 if Is_Tagged_Type (Rectype)
6032 and then Fbit < System_Address_Size
6035 ("component overlaps tag field of&",
6036 Component_Name (CC), Rectype);
6037 Overlap_Detected := True;
6045 -- Check parent overlap if component might overlap parent field
6047 if Present (Tagged_Parent)
6048 and then Fbit <= Parent_Last_Bit
6050 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
6051 while Present (Pcomp) loop
6052 if not Is_Tag (Pcomp)
6053 and then Chars (Pcomp) /= Name_uParent
6055 Check_Component_Overlap (Comp, Pcomp);
6058 Next_Component_Or_Discriminant (Pcomp);
6066 -- Now that we have processed all the component clauses, check for
6067 -- overlap. We have to leave this till last, since the components can
6068 -- appear in any arbitrary order in the representation clause.
6070 -- We do not need this check if all specified ranges were monotonic,
6071 -- as recorded by Overlap_Check_Required being False at this stage.
6073 -- This first section checks if there are any overlapping entries at
6074 -- all. It does this by sorting all entries and then seeing if there are
6075 -- any overlaps. If there are none, then that is decisive, but if there
6076 -- are overlaps, they may still be OK (they may result from fields in
6077 -- different variants).
6079 if Overlap_Check_Required then
6080 Overlap_Check1 : declare
6082 OC_Fbit : array (0 .. Ccount) of Uint;
6083 -- First-bit values for component clauses, the value is the offset
6084 -- of the first bit of the field from start of record. The zero
6085 -- entry is for use in sorting.
6087 OC_Lbit : array (0 .. Ccount) of Uint;
6088 -- Last-bit values for component clauses, the value is the offset
6089 -- of the last bit of the field from start of record. The zero
6090 -- entry is for use in sorting.
6092 OC_Count : Natural := 0;
6093 -- Count of entries in OC_Fbit and OC_Lbit
6095 function OC_Lt (Op1, Op2 : Natural) return Boolean;
6096 -- Compare routine for Sort
6098 procedure OC_Move (From : Natural; To : Natural);
6099 -- Move routine for Sort
6101 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
6107 function OC_Lt (Op1, Op2 : Natural) return Boolean is
6109 return OC_Fbit (Op1) < OC_Fbit (Op2);
6116 procedure OC_Move (From : Natural; To : Natural) is
6118 OC_Fbit (To) := OC_Fbit (From);
6119 OC_Lbit (To) := OC_Lbit (From);
6122 -- Start of processing for Overlap_Check
6125 CC := First (Component_Clauses (N));
6126 while Present (CC) loop
6128 -- Exclude component clause already marked in error
6130 if not Error_Posted (CC) then
6133 if Present (Comp) then
6134 OC_Count := OC_Count + 1;
6135 OC_Fbit (OC_Count) := Fbit;
6136 OC_Lbit (OC_Count) := Lbit;
6143 Sorting.Sort (OC_Count);
6145 Overlap_Check_Required := False;
6146 for J in 1 .. OC_Count - 1 loop
6147 if OC_Lbit (J) >= OC_Fbit (J + 1) then
6148 Overlap_Check_Required := True;
6155 -- If Overlap_Check_Required is still True, then we have to do the full
6156 -- scale overlap check, since we have at least two fields that do
6157 -- overlap, and we need to know if that is OK since they are in
6158 -- different variant, or whether we have a definite problem.
6160 if Overlap_Check_Required then
6161 Overlap_Check2 : declare
6162 C1_Ent, C2_Ent : Entity_Id;
6163 -- Entities of components being checked for overlap
6166 -- Component_List node whose Component_Items are being checked
6169 -- Component declaration for component being checked
6172 C1_Ent := First_Entity (Base_Type (Rectype));
6174 -- Loop through all components in record. For each component check
6175 -- for overlap with any of the preceding elements on the component
6176 -- list containing the component and also, if the component is in
6177 -- a variant, check against components outside the case structure.
6178 -- This latter test is repeated recursively up the variant tree.
6180 Main_Component_Loop : while Present (C1_Ent) loop
6181 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
6182 goto Continue_Main_Component_Loop;
6185 -- Skip overlap check if entity has no declaration node. This
6186 -- happens with discriminants in constrained derived types.
6187 -- Possibly we are missing some checks as a result, but that
6188 -- does not seem terribly serious.
6190 if No (Declaration_Node (C1_Ent)) then
6191 goto Continue_Main_Component_Loop;
6194 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
6196 -- Loop through component lists that need checking. Check the
6197 -- current component list and all lists in variants above us.
6199 Component_List_Loop : loop
6201 -- If derived type definition, go to full declaration
6202 -- If at outer level, check discriminants if there are any.
6204 if Nkind (Clist) = N_Derived_Type_Definition then
6205 Clist := Parent (Clist);
6208 -- Outer level of record definition, check discriminants
6210 if Nkind_In (Clist, N_Full_Type_Declaration,
6211 N_Private_Type_Declaration)
6213 if Has_Discriminants (Defining_Identifier (Clist)) then
6215 First_Discriminant (Defining_Identifier (Clist));
6216 while Present (C2_Ent) loop
6217 exit when C1_Ent = C2_Ent;
6218 Check_Component_Overlap (C1_Ent, C2_Ent);
6219 Next_Discriminant (C2_Ent);
6223 -- Record extension case
6225 elsif Nkind (Clist) = N_Derived_Type_Definition then
6228 -- Otherwise check one component list
6231 Citem := First (Component_Items (Clist));
6232 while Present (Citem) loop
6233 if Nkind (Citem) = N_Component_Declaration then
6234 C2_Ent := Defining_Identifier (Citem);
6235 exit when C1_Ent = C2_Ent;
6236 Check_Component_Overlap (C1_Ent, C2_Ent);
6243 -- Check for variants above us (the parent of the Clist can
6244 -- be a variant, in which case its parent is a variant part,
6245 -- and the parent of the variant part is a component list
6246 -- whose components must all be checked against the current
6247 -- component for overlap).
6249 if Nkind (Parent (Clist)) = N_Variant then
6250 Clist := Parent (Parent (Parent (Clist)));
6252 -- Check for possible discriminant part in record, this
6253 -- is treated essentially as another level in the
6254 -- recursion. For this case the parent of the component
6255 -- list is the record definition, and its parent is the
6256 -- full type declaration containing the discriminant
6259 elsif Nkind (Parent (Clist)) = N_Record_Definition then
6260 Clist := Parent (Parent ((Clist)));
6262 -- If neither of these two cases, we are at the top of
6266 exit Component_List_Loop;
6268 end loop Component_List_Loop;
6270 <<Continue_Main_Component_Loop>>
6271 Next_Entity (C1_Ent);
6273 end loop Main_Component_Loop;
6277 -- The following circuit deals with warning on record holes (gaps). We
6278 -- skip this check if overlap was detected, since it makes sense for the
6279 -- programmer to fix this illegality before worrying about warnings.
6281 if not Overlap_Detected and Warn_On_Record_Holes then
6282 Record_Hole_Check : declare
6283 Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype));
6284 -- Full declaration of record type
6286 procedure Check_Component_List
6290 -- Check component list CL for holes. The starting bit should be
6291 -- Sbit. which is zero for the main record component list and set
6292 -- appropriately for recursive calls for variants. DS is set to
6293 -- a list of discriminant specifications to be included in the
6294 -- consideration of components. It is No_List if none to consider.
6296 --------------------------
6297 -- Check_Component_List --
6298 --------------------------
6300 procedure Check_Component_List
6308 Compl := Integer (List_Length (Component_Items (CL)));
6310 if DS /= No_List then
6311 Compl := Compl + Integer (List_Length (DS));
6315 Comps : array (Natural range 0 .. Compl) of Entity_Id;
6316 -- Gather components (zero entry is for sort routine)
6318 Ncomps : Natural := 0;
6319 -- Number of entries stored in Comps (starting at Comps (1))
6322 -- One component item or discriminant specification
6325 -- Starting bit for next component
6333 function Lt (Op1, Op2 : Natural) return Boolean;
6334 -- Compare routine for Sort
6336 procedure Move (From : Natural; To : Natural);
6337 -- Move routine for Sort
6339 package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
6345 function Lt (Op1, Op2 : Natural) return Boolean is
6347 return Component_Bit_Offset (Comps (Op1))
6349 Component_Bit_Offset (Comps (Op2));
6356 procedure Move (From : Natural; To : Natural) is
6358 Comps (To) := Comps (From);
6362 -- Gather discriminants into Comp
6364 if DS /= No_List then
6365 Citem := First (DS);
6366 while Present (Citem) loop
6367 if Nkind (Citem) = N_Discriminant_Specification then
6369 Ent : constant Entity_Id :=
6370 Defining_Identifier (Citem);
6372 if Ekind (Ent) = E_Discriminant then
6373 Ncomps := Ncomps + 1;
6374 Comps (Ncomps) := Ent;
6383 -- Gather component entities into Comp
6385 Citem := First (Component_Items (CL));
6386 while Present (Citem) loop
6387 if Nkind (Citem) = N_Component_Declaration then
6388 Ncomps := Ncomps + 1;
6389 Comps (Ncomps) := Defining_Identifier (Citem);
6395 -- Now sort the component entities based on the first bit.
6396 -- Note we already know there are no overlapping components.
6398 Sorting.Sort (Ncomps);
6400 -- Loop through entries checking for holes
6403 for J in 1 .. Ncomps loop
6405 Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
6407 if Error_Msg_Uint_1 > 0 then
6409 ("?^-bit gap before component&",
6410 Component_Name (Component_Clause (CEnt)), CEnt);
6413 Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
6416 -- Process variant parts recursively if present
6418 if Present (Variant_Part (CL)) then
6419 Variant := First (Variants (Variant_Part (CL)));
6420 while Present (Variant) loop
6421 Check_Component_List
6422 (Component_List (Variant), Nbit, No_List);
6427 end Check_Component_List;
6429 -- Start of processing for Record_Hole_Check
6436 if Is_Tagged_Type (Rectype) then
6437 Sbit := UI_From_Int (System_Address_Size);
6442 if Nkind (Decl) = N_Full_Type_Declaration
6443 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
6445 Check_Component_List
6446 (Component_List (Type_Definition (Decl)),
6448 Discriminant_Specifications (Decl));
6451 end Record_Hole_Check;
6454 -- For records that have component clauses for all components, and whose
6455 -- size is less than or equal to 32, we need to know the size in the
6456 -- front end to activate possible packed array processing where the
6457 -- component type is a record.
6459 -- At this stage Hbit + 1 represents the first unused bit from all the
6460 -- component clauses processed, so if the component clauses are
6461 -- complete, then this is the length of the record.
6463 -- For records longer than System.Storage_Unit, and for those where not
6464 -- all components have component clauses, the back end determines the
6465 -- length (it may for example be appropriate to round up the size
6466 -- to some convenient boundary, based on alignment considerations, etc).
6468 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
6470 -- Nothing to do if at least one component has no component clause
6472 Comp := First_Component_Or_Discriminant (Rectype);
6473 while Present (Comp) loop
6474 exit when No (Component_Clause (Comp));
6475 Next_Component_Or_Discriminant (Comp);
6478 -- If we fall out of loop, all components have component clauses
6479 -- and so we can set the size to the maximum value.
6482 Set_RM_Size (Rectype, Hbit + 1);
6485 end Check_Record_Representation_Clause;
6491 procedure Check_Size
6495 Biased : out Boolean)
6497 UT : constant Entity_Id := Underlying_Type (T);
6503 -- Dismiss cases for generic types or types with previous errors
6506 or else UT = Any_Type
6507 or else Is_Generic_Type (UT)
6508 or else Is_Generic_Type (Root_Type (UT))
6512 -- Check case of bit packed array
6514 elsif Is_Array_Type (UT)
6515 and then Known_Static_Component_Size (UT)
6516 and then Is_Bit_Packed_Array (UT)
6524 Asiz := Component_Size (UT);
6525 Indx := First_Index (UT);
6527 Ityp := Etype (Indx);
6529 -- If non-static bound, then we are not in the business of
6530 -- trying to check the length, and indeed an error will be
6531 -- issued elsewhere, since sizes of non-static array types
6532 -- cannot be set implicitly or explicitly.
6534 if not Is_Static_Subtype (Ityp) then
6538 -- Otherwise accumulate next dimension
6540 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
6541 Expr_Value (Type_Low_Bound (Ityp)) +
6545 exit when No (Indx);
6551 Error_Msg_Uint_1 := Asiz;
6553 ("size for& too small, minimum allowed is ^", N, T);
6554 Set_Esize (T, Asiz);
6555 Set_RM_Size (T, Asiz);
6559 -- All other composite types are ignored
6561 elsif Is_Composite_Type (UT) then
6564 -- For fixed-point types, don't check minimum if type is not frozen,
6565 -- since we don't know all the characteristics of the type that can
6566 -- affect the size (e.g. a specified small) till freeze time.
6568 elsif Is_Fixed_Point_Type (UT)
6569 and then not Is_Frozen (UT)
6573 -- Cases for which a minimum check is required
6576 -- Ignore if specified size is correct for the type
6578 if Known_Esize (UT) and then Siz = Esize (UT) then
6582 -- Otherwise get minimum size
6584 M := UI_From_Int (Minimum_Size (UT));
6588 -- Size is less than minimum size, but one possibility remains
6589 -- that we can manage with the new size if we bias the type.
6591 M := UI_From_Int (Minimum_Size (UT, Biased => True));
6594 Error_Msg_Uint_1 := M;
6596 ("size for& too small, minimum allowed is ^", N, T);
6606 -------------------------
6607 -- Get_Alignment_Value --
6608 -------------------------
6610 function Get_Alignment_Value (Expr : Node_Id) return Uint is
6611 Align : constant Uint := Static_Integer (Expr);
6614 if Align = No_Uint then
6617 elsif Align <= 0 then
6618 Error_Msg_N ("alignment value must be positive", Expr);
6622 for J in Int range 0 .. 64 loop
6624 M : constant Uint := Uint_2 ** J;
6627 exit when M = Align;
6631 ("alignment value must be power of 2", Expr);
6639 end Get_Alignment_Value;
6645 procedure Initialize is
6647 Address_Clause_Checks.Init;
6648 Independence_Checks.Init;
6649 Unchecked_Conversions.Init;
6652 -------------------------
6653 -- Is_Operational_Item --
6654 -------------------------
6656 function Is_Operational_Item (N : Node_Id) return Boolean is
6658 if Nkind (N) /= N_Attribute_Definition_Clause then
6662 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
6664 return Id = Attribute_Input
6665 or else Id = Attribute_Output
6666 or else Id = Attribute_Read
6667 or else Id = Attribute_Write
6668 or else Id = Attribute_External_Tag;
6671 end Is_Operational_Item;
6677 function Minimum_Size
6679 Biased : Boolean := False) return Nat
6681 Lo : Uint := No_Uint;
6682 Hi : Uint := No_Uint;
6683 LoR : Ureal := No_Ureal;
6684 HiR : Ureal := No_Ureal;
6685 LoSet : Boolean := False;
6686 HiSet : Boolean := False;
6690 R_Typ : constant Entity_Id := Root_Type (T);
6693 -- If bad type, return 0
6695 if T = Any_Type then
6698 -- For generic types, just return zero. There cannot be any legitimate
6699 -- need to know such a size, but this routine may be called with a
6700 -- generic type as part of normal processing.
6702 elsif Is_Generic_Type (R_Typ)
6703 or else R_Typ = Any_Type
6707 -- Access types. Normally an access type cannot have a size smaller
6708 -- than the size of System.Address. The exception is on VMS, where
6709 -- we have short and long addresses, and it is possible for an access
6710 -- type to have a short address size (and thus be less than the size
6711 -- of System.Address itself). We simply skip the check for VMS, and
6712 -- leave it to the back end to do the check.
6714 elsif Is_Access_Type (T) then
6715 if OpenVMS_On_Target then
6718 return System_Address_Size;
6721 -- Floating-point types
6723 elsif Is_Floating_Point_Type (T) then
6724 return UI_To_Int (Esize (R_Typ));
6728 elsif Is_Discrete_Type (T) then
6730 -- The following loop is looking for the nearest compile time known
6731 -- bounds following the ancestor subtype chain. The idea is to find
6732 -- the most restrictive known bounds information.
6736 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
6741 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
6742 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
6749 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
6750 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
6756 Ancest := Ancestor_Subtype (Ancest);
6759 Ancest := Base_Type (T);
6761 if Is_Generic_Type (Ancest) then
6767 -- Fixed-point types. We can't simply use Expr_Value to get the
6768 -- Corresponding_Integer_Value values of the bounds, since these do not
6769 -- get set till the type is frozen, and this routine can be called
6770 -- before the type is frozen. Similarly the test for bounds being static
6771 -- needs to include the case where we have unanalyzed real literals for
6774 elsif Is_Fixed_Point_Type (T) then
6776 -- The following loop is looking for the nearest compile time known
6777 -- bounds following the ancestor subtype chain. The idea is to find
6778 -- the most restrictive known bounds information.
6782 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
6786 -- Note: In the following two tests for LoSet and HiSet, it may
6787 -- seem redundant to test for N_Real_Literal here since normally
6788 -- one would assume that the test for the value being known at
6789 -- compile time includes this case. However, there is a glitch.
6790 -- If the real literal comes from folding a non-static expression,
6791 -- then we don't consider any non- static expression to be known
6792 -- at compile time if we are in configurable run time mode (needed
6793 -- in some cases to give a clearer definition of what is and what
6794 -- is not accepted). So the test is indeed needed. Without it, we
6795 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
6798 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
6799 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
6801 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
6808 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
6809 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
6811 HiR := Expr_Value_R (Type_High_Bound (Ancest));
6817 Ancest := Ancestor_Subtype (Ancest);
6820 Ancest := Base_Type (T);
6822 if Is_Generic_Type (Ancest) then
6828 Lo := UR_To_Uint (LoR / Small_Value (T));
6829 Hi := UR_To_Uint (HiR / Small_Value (T));
6831 -- No other types allowed
6834 raise Program_Error;
6837 -- Fall through with Hi and Lo set. Deal with biased case
6840 and then not Is_Fixed_Point_Type (T)
6841 and then not (Is_Enumeration_Type (T)
6842 and then Has_Non_Standard_Rep (T)))
6843 or else Has_Biased_Representation (T)
6849 -- Signed case. Note that we consider types like range 1 .. -1 to be
6850 -- signed for the purpose of computing the size, since the bounds have
6851 -- to be accommodated in the base type.
6853 if Lo < 0 or else Hi < 0 then
6857 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
6858 -- Note that we accommodate the case where the bounds cross. This
6859 -- can happen either because of the way the bounds are declared
6860 -- or because of the algorithm in Freeze_Fixed_Point_Type.
6874 -- If both bounds are positive, make sure that both are represen-
6875 -- table in the case where the bounds are crossed. This can happen
6876 -- either because of the way the bounds are declared, or because of
6877 -- the algorithm in Freeze_Fixed_Point_Type.
6883 -- S = size, (can accommodate 0 .. (2**size - 1))
6886 while Hi >= Uint_2 ** S loop
6894 ---------------------------
6895 -- New_Stream_Subprogram --
6896 ---------------------------
6898 procedure New_Stream_Subprogram
6902 Nam : TSS_Name_Type)
6904 Loc : constant Source_Ptr := Sloc (N);
6905 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
6906 Subp_Id : Entity_Id;
6907 Subp_Decl : Node_Id;
6911 Defer_Declaration : constant Boolean :=
6912 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
6913 -- For a tagged type, there is a declaration for each stream attribute
6914 -- at the freeze point, and we must generate only a completion of this
6915 -- declaration. We do the same for private types, because the full view
6916 -- might be tagged. Otherwise we generate a declaration at the point of
6917 -- the attribute definition clause.
6919 function Build_Spec return Node_Id;
6920 -- Used for declaration and renaming declaration, so that this is
6921 -- treated as a renaming_as_body.
6927 function Build_Spec return Node_Id is
6928 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
6931 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
6934 Subp_Id := Make_Defining_Identifier (Loc, Sname);
6936 -- S : access Root_Stream_Type'Class
6938 Formals := New_List (
6939 Make_Parameter_Specification (Loc,
6940 Defining_Identifier =>
6941 Make_Defining_Identifier (Loc, Name_S),
6943 Make_Access_Definition (Loc,
6946 Designated_Type (Etype (F)), Loc))));
6948 if Nam = TSS_Stream_Input then
6949 Spec := Make_Function_Specification (Loc,
6950 Defining_Unit_Name => Subp_Id,
6951 Parameter_Specifications => Formals,
6952 Result_Definition => T_Ref);
6957 Make_Parameter_Specification (Loc,
6958 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
6959 Out_Present => Out_P,
6960 Parameter_Type => T_Ref));
6963 Make_Procedure_Specification (Loc,
6964 Defining_Unit_Name => Subp_Id,
6965 Parameter_Specifications => Formals);
6971 -- Start of processing for New_Stream_Subprogram
6974 F := First_Formal (Subp);
6976 if Ekind (Subp) = E_Procedure then
6977 Etyp := Etype (Next_Formal (F));
6979 Etyp := Etype (Subp);
6982 -- Prepare subprogram declaration and insert it as an action on the
6983 -- clause node. The visibility for this entity is used to test for
6984 -- visibility of the attribute definition clause (in the sense of
6985 -- 8.3(23) as amended by AI-195).
6987 if not Defer_Declaration then
6989 Make_Subprogram_Declaration (Loc,
6990 Specification => Build_Spec);
6992 -- For a tagged type, there is always a visible declaration for each
6993 -- stream TSS (it is a predefined primitive operation), and the
6994 -- completion of this declaration occurs at the freeze point, which is
6995 -- not always visible at places where the attribute definition clause is
6996 -- visible. So, we create a dummy entity here for the purpose of
6997 -- tracking the visibility of the attribute definition clause itself.
7001 Make_Defining_Identifier (Loc, New_External_Name (Sname, 'V'));
7003 Make_Object_Declaration (Loc,
7004 Defining_Identifier => Subp_Id,
7005 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
7008 Insert_Action (N, Subp_Decl);
7009 Set_Entity (N, Subp_Id);
7012 Make_Subprogram_Renaming_Declaration (Loc,
7013 Specification => Build_Spec,
7014 Name => New_Reference_To (Subp, Loc));
7016 if Defer_Declaration then
7017 Set_TSS (Base_Type (Ent), Subp_Id);
7019 Insert_Action (N, Subp_Decl);
7020 Copy_TSS (Subp_Id, Base_Type (Ent));
7022 end New_Stream_Subprogram;
7024 ------------------------
7025 -- Rep_Item_Too_Early --
7026 ------------------------
7028 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
7030 -- Cannot apply non-operational rep items to generic types
7032 if Is_Operational_Item (N) then
7036 and then Is_Generic_Type (Root_Type (T))
7038 Error_Msg_N ("representation item not allowed for generic type", N);
7042 -- Otherwise check for incomplete type
7044 if Is_Incomplete_Or_Private_Type (T)
7045 and then No (Underlying_Type (T))
7047 (Nkind (N) /= N_Pragma
7048 or else Get_Pragma_Id (N) /= Pragma_Import)
7051 ("representation item must be after full type declaration", N);
7054 -- If the type has incomplete components, a representation clause is
7055 -- illegal but stream attributes and Convention pragmas are correct.
7057 elsif Has_Private_Component (T) then
7058 if Nkind (N) = N_Pragma then
7062 ("representation item must appear after type is fully defined",
7069 end Rep_Item_Too_Early;
7071 -----------------------
7072 -- Rep_Item_Too_Late --
7073 -----------------------
7075 function Rep_Item_Too_Late
7078 FOnly : Boolean := False) return Boolean
7081 Parent_Type : Entity_Id;
7084 -- Output the too late message. Note that this is not considered a
7085 -- serious error, since the effect is simply that we ignore the
7086 -- representation clause in this case.
7092 procedure Too_Late is
7094 Error_Msg_N ("|representation item appears too late!", N);
7097 -- Start of processing for Rep_Item_Too_Late
7100 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
7101 -- types, which may be frozen if they appear in a representation clause
7102 -- for a local type.
7105 and then not From_With_Type (T)
7108 S := First_Subtype (T);
7110 if Present (Freeze_Node (S)) then
7112 ("?no more representation items for }", Freeze_Node (S), S);
7117 -- Check for case of non-tagged derived type whose parent either has
7118 -- primitive operations, or is a by reference type (RM 13.1(10)).
7122 and then Is_Derived_Type (T)
7123 and then not Is_Tagged_Type (T)
7125 Parent_Type := Etype (Base_Type (T));
7127 if Has_Primitive_Operations (Parent_Type) then
7130 ("primitive operations already defined for&!", N, Parent_Type);
7133 elsif Is_By_Reference_Type (Parent_Type) then
7136 ("parent type & is a by reference type!", N, Parent_Type);
7141 -- No error, link item into head of chain of rep items for the entity,
7142 -- but avoid chaining if we have an overloadable entity, and the pragma
7143 -- is one that can apply to multiple overloaded entities.
7145 if Is_Overloadable (T)
7146 and then Nkind (N) = N_Pragma
7149 Pname : constant Name_Id := Pragma_Name (N);
7151 if Pname = Name_Convention or else
7152 Pname = Name_Import or else
7153 Pname = Name_Export or else
7154 Pname = Name_External or else
7155 Pname = Name_Interface
7162 Record_Rep_Item (T, N);
7164 end Rep_Item_Too_Late;
7166 -------------------------------------
7167 -- Replace_Type_References_Generic --
7168 -------------------------------------
7170 procedure Replace_Type_References_Generic (N : Node_Id; TName : Name_Id) is
7172 function Replace_Node (N : Node_Id) return Traverse_Result;
7173 -- Processes a single node in the traversal procedure below, checking
7174 -- if node N should be replaced, and if so, doing the replacement.
7176 procedure Replace_Type_Refs is new Traverse_Proc (Replace_Node);
7177 -- This instantiation provides the body of Replace_Type_References
7183 function Replace_Node (N : Node_Id) return Traverse_Result is
7188 -- Case of identifier
7190 if Nkind (N) = N_Identifier then
7192 -- If not the type name, all done with this node
7194 if Chars (N) /= TName then
7197 -- Otherwise do the replacement and we are done with this node
7200 Replace_Type_Reference (N);
7204 -- Case of selected component (which is what a qualification
7205 -- looks like in the unanalyzed tree, which is what we have.
7207 elsif Nkind (N) = N_Selected_Component then
7209 -- If selector name is not our type, keeping going (we might
7210 -- still have an occurrence of the type in the prefix).
7212 if Nkind (Selector_Name (N)) /= N_Identifier
7213 or else Chars (Selector_Name (N)) /= TName
7217 -- Selector name is our type, check qualification
7220 -- Loop through scopes and prefixes, doing comparison
7225 -- Continue if no more scopes or scope with no name
7227 if No (S) or else Nkind (S) not in N_Has_Chars then
7231 -- Do replace if prefix is an identifier matching the
7232 -- scope that we are currently looking at.
7234 if Nkind (P) = N_Identifier
7235 and then Chars (P) = Chars (S)
7237 Replace_Type_Reference (N);
7241 -- Go check scope above us if prefix is itself of the
7242 -- form of a selected component, whose selector matches
7243 -- the scope we are currently looking at.
7245 if Nkind (P) = N_Selected_Component
7246 and then Nkind (Selector_Name (P)) = N_Identifier
7247 and then Chars (Selector_Name (P)) = Chars (S)
7252 -- For anything else, we don't have a match, so keep on
7253 -- going, there are still some weird cases where we may
7254 -- still have a replacement within the prefix.
7262 -- Continue for any other node kind
7270 Replace_Type_Refs (N);
7271 end Replace_Type_References_Generic;
7273 -------------------------
7274 -- Same_Representation --
7275 -------------------------
7277 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
7278 T1 : constant Entity_Id := Underlying_Type (Typ1);
7279 T2 : constant Entity_Id := Underlying_Type (Typ2);
7282 -- A quick check, if base types are the same, then we definitely have
7283 -- the same representation, because the subtype specific representation
7284 -- attributes (Size and Alignment) do not affect representation from
7285 -- the point of view of this test.
7287 if Base_Type (T1) = Base_Type (T2) then
7290 elsif Is_Private_Type (Base_Type (T2))
7291 and then Base_Type (T1) = Full_View (Base_Type (T2))
7296 -- Tagged types never have differing representations
7298 if Is_Tagged_Type (T1) then
7302 -- Representations are definitely different if conventions differ
7304 if Convention (T1) /= Convention (T2) then
7308 -- Representations are different if component alignments differ
7310 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
7312 (Is_Record_Type (T2) or else Is_Array_Type (T2))
7313 and then Component_Alignment (T1) /= Component_Alignment (T2)
7318 -- For arrays, the only real issue is component size. If we know the
7319 -- component size for both arrays, and it is the same, then that's
7320 -- good enough to know we don't have a change of representation.
7322 if Is_Array_Type (T1) then
7323 if Known_Component_Size (T1)
7324 and then Known_Component_Size (T2)
7325 and then Component_Size (T1) = Component_Size (T2)
7327 if VM_Target = No_VM then
7330 -- In VM targets the representation of arrays with aliased
7331 -- components differs from arrays with non-aliased components
7334 return Has_Aliased_Components (Base_Type (T1))
7336 Has_Aliased_Components (Base_Type (T2));
7341 -- Types definitely have same representation if neither has non-standard
7342 -- representation since default representations are always consistent.
7343 -- If only one has non-standard representation, and the other does not,
7344 -- then we consider that they do not have the same representation. They
7345 -- might, but there is no way of telling early enough.
7347 if Has_Non_Standard_Rep (T1) then
7348 if not Has_Non_Standard_Rep (T2) then
7352 return not Has_Non_Standard_Rep (T2);
7355 -- Here the two types both have non-standard representation, and we need
7356 -- to determine if they have the same non-standard representation.
7358 -- For arrays, we simply need to test if the component sizes are the
7359 -- same. Pragma Pack is reflected in modified component sizes, so this
7360 -- check also deals with pragma Pack.
7362 if Is_Array_Type (T1) then
7363 return Component_Size (T1) = Component_Size (T2);
7365 -- Tagged types always have the same representation, because it is not
7366 -- possible to specify different representations for common fields.
7368 elsif Is_Tagged_Type (T1) then
7371 -- Case of record types
7373 elsif Is_Record_Type (T1) then
7375 -- Packed status must conform
7377 if Is_Packed (T1) /= Is_Packed (T2) then
7380 -- Otherwise we must check components. Typ2 maybe a constrained
7381 -- subtype with fewer components, so we compare the components
7382 -- of the base types.
7385 Record_Case : declare
7386 CD1, CD2 : Entity_Id;
7388 function Same_Rep return Boolean;
7389 -- CD1 and CD2 are either components or discriminants. This
7390 -- function tests whether the two have the same representation
7396 function Same_Rep return Boolean is
7398 if No (Component_Clause (CD1)) then
7399 return No (Component_Clause (CD2));
7403 Present (Component_Clause (CD2))
7405 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
7407 Esize (CD1) = Esize (CD2);
7411 -- Start of processing for Record_Case
7414 if Has_Discriminants (T1) then
7415 CD1 := First_Discriminant (T1);
7416 CD2 := First_Discriminant (T2);
7418 -- The number of discriminants may be different if the
7419 -- derived type has fewer (constrained by values). The
7420 -- invisible discriminants retain the representation of
7421 -- the original, so the discrepancy does not per se
7422 -- indicate a different representation.
7425 and then Present (CD2)
7427 if not Same_Rep then
7430 Next_Discriminant (CD1);
7431 Next_Discriminant (CD2);
7436 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
7437 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
7439 while Present (CD1) loop
7440 if not Same_Rep then
7443 Next_Component (CD1);
7444 Next_Component (CD2);
7452 -- For enumeration types, we must check each literal to see if the
7453 -- representation is the same. Note that we do not permit enumeration
7454 -- representation clauses for Character and Wide_Character, so these
7455 -- cases were already dealt with.
7457 elsif Is_Enumeration_Type (T1) then
7458 Enumeration_Case : declare
7462 L1 := First_Literal (T1);
7463 L2 := First_Literal (T2);
7465 while Present (L1) loop
7466 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
7476 end Enumeration_Case;
7478 -- Any other types have the same representation for these purposes
7483 end Same_Representation;
7489 procedure Set_Biased
7493 Biased : Boolean := True)
7497 Set_Has_Biased_Representation (E);
7499 if Warn_On_Biased_Representation then
7501 ("?" & Msg & " forces biased representation for&", N, E);
7506 --------------------
7507 -- Set_Enum_Esize --
7508 --------------------
7510 procedure Set_Enum_Esize (T : Entity_Id) is
7518 -- Find the minimum standard size (8,16,32,64) that fits
7520 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
7521 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
7524 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
7525 Sz := Standard_Character_Size; -- May be > 8 on some targets
7527 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
7530 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
7533 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
7538 if Hi < Uint_2**08 then
7539 Sz := Standard_Character_Size; -- May be > 8 on some targets
7541 elsif Hi < Uint_2**16 then
7544 elsif Hi < Uint_2**32 then
7547 else pragma Assert (Hi < Uint_2**63);
7552 -- That minimum is the proper size unless we have a foreign convention
7553 -- and the size required is 32 or less, in which case we bump the size
7554 -- up to 32. This is required for C and C++ and seems reasonable for
7555 -- all other foreign conventions.
7557 if Has_Foreign_Convention (T)
7558 and then Esize (T) < Standard_Integer_Size
7560 Init_Esize (T, Standard_Integer_Size);
7566 ------------------------------
7567 -- Validate_Address_Clauses --
7568 ------------------------------
7570 procedure Validate_Address_Clauses is
7572 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
7574 ACCR : Address_Clause_Check_Record
7575 renames Address_Clause_Checks.Table (J);
7586 -- Skip processing of this entry if warning already posted
7588 if not Address_Warning_Posted (ACCR.N) then
7590 Expr := Original_Node (Expression (ACCR.N));
7594 X_Alignment := Alignment (ACCR.X);
7595 Y_Alignment := Alignment (ACCR.Y);
7597 -- Similarly obtain sizes
7599 X_Size := Esize (ACCR.X);
7600 Y_Size := Esize (ACCR.Y);
7602 -- Check for large object overlaying smaller one
7605 and then X_Size > Uint_0
7606 and then X_Size > Y_Size
7609 ("?& overlays smaller object", ACCR.N, ACCR.X);
7611 ("\?program execution may be erroneous", ACCR.N);
7612 Error_Msg_Uint_1 := X_Size;
7614 ("\?size of & is ^", ACCR.N, ACCR.X);
7615 Error_Msg_Uint_1 := Y_Size;
7617 ("\?size of & is ^", ACCR.N, ACCR.Y);
7619 -- Check for inadequate alignment, both of the base object
7620 -- and of the offset, if any.
7622 -- Note: we do not check the alignment if we gave a size
7623 -- warning, since it would likely be redundant.
7625 elsif Y_Alignment /= Uint_0
7626 and then (Y_Alignment < X_Alignment
7629 Nkind (Expr) = N_Attribute_Reference
7631 Attribute_Name (Expr) = Name_Address
7633 Has_Compatible_Alignment
7634 (ACCR.X, Prefix (Expr))
7635 /= Known_Compatible))
7638 ("?specified address for& may be inconsistent "
7642 ("\?program execution may be erroneous (RM 13.3(27))",
7644 Error_Msg_Uint_1 := X_Alignment;
7646 ("\?alignment of & is ^",
7648 Error_Msg_Uint_1 := Y_Alignment;
7650 ("\?alignment of & is ^",
7652 if Y_Alignment >= X_Alignment then
7654 ("\?but offset is not multiple of alignment",
7661 end Validate_Address_Clauses;
7663 ---------------------------
7664 -- Validate_Independence --
7665 ---------------------------
7667 procedure Validate_Independence is
7668 SU : constant Uint := UI_From_Int (System_Storage_Unit);
7676 procedure Check_Array_Type (Atyp : Entity_Id);
7677 -- Checks if the array type Atyp has independent components, and
7678 -- if not, outputs an appropriate set of error messages.
7680 procedure No_Independence;
7681 -- Output message that independence cannot be guaranteed
7683 function OK_Component (C : Entity_Id) return Boolean;
7684 -- Checks one component to see if it is independently accessible, and
7685 -- if so yields True, otherwise yields False if independent access
7686 -- cannot be guaranteed. This is a conservative routine, it only
7687 -- returns True if it knows for sure, it returns False if it knows
7688 -- there is a problem, or it cannot be sure there is no problem.
7690 procedure Reason_Bad_Component (C : Entity_Id);
7691 -- Outputs continuation message if a reason can be determined for
7692 -- the component C being bad.
7694 ----------------------
7695 -- Check_Array_Type --
7696 ----------------------
7698 procedure Check_Array_Type (Atyp : Entity_Id) is
7699 Ctyp : constant Entity_Id := Component_Type (Atyp);
7702 -- OK if no alignment clause, no pack, and no component size
7704 if not Has_Component_Size_Clause (Atyp)
7705 and then not Has_Alignment_Clause (Atyp)
7706 and then not Is_Packed (Atyp)
7711 -- Check actual component size
7713 if not Known_Component_Size (Atyp)
7714 or else not (Addressable (Component_Size (Atyp))
7715 and then Component_Size (Atyp) < 64)
7716 or else Component_Size (Atyp) mod Esize (Ctyp) /= 0
7720 -- Bad component size, check reason
7722 if Has_Component_Size_Clause (Atyp) then
7724 Get_Attribute_Definition_Clause
7725 (Atyp, Attribute_Component_Size);
7728 Error_Msg_Sloc := Sloc (P);
7729 Error_Msg_N ("\because of Component_Size clause#", N);
7734 if Is_Packed (Atyp) then
7735 P := Get_Rep_Pragma (Atyp, Name_Pack);
7738 Error_Msg_Sloc := Sloc (P);
7739 Error_Msg_N ("\because of pragma Pack#", N);
7744 -- No reason found, just return
7749 -- Array type is OK independence-wise
7752 end Check_Array_Type;
7754 ---------------------
7755 -- No_Independence --
7756 ---------------------
7758 procedure No_Independence is
7760 if Pragma_Name (N) = Name_Independent then
7762 ("independence cannot be guaranteed for&", N, E);
7765 ("independent components cannot be guaranteed for&", N, E);
7767 end No_Independence;
7773 function OK_Component (C : Entity_Id) return Boolean is
7774 Rec : constant Entity_Id := Scope (C);
7775 Ctyp : constant Entity_Id := Etype (C);
7778 -- OK if no component clause, no Pack, and no alignment clause
7780 if No (Component_Clause (C))
7781 and then not Is_Packed (Rec)
7782 and then not Has_Alignment_Clause (Rec)
7787 -- Here we look at the actual component layout. A component is
7788 -- addressable if its size is a multiple of the Esize of the
7789 -- component type, and its starting position in the record has
7790 -- appropriate alignment, and the record itself has appropriate
7791 -- alignment to guarantee the component alignment.
7793 -- Make sure sizes are static, always assume the worst for any
7794 -- cases where we cannot check static values.
7796 if not (Known_Static_Esize (C)
7797 and then Known_Static_Esize (Ctyp))
7802 -- Size of component must be addressable or greater than 64 bits
7803 -- and a multiple of bytes.
7805 if not Addressable (Esize (C))
7806 and then Esize (C) < Uint_64
7811 -- Check size is proper multiple
7813 if Esize (C) mod Esize (Ctyp) /= 0 then
7817 -- Check alignment of component is OK
7819 if not Known_Component_Bit_Offset (C)
7820 or else Component_Bit_Offset (C) < Uint_0
7821 or else Component_Bit_Offset (C) mod Esize (Ctyp) /= 0
7826 -- Check alignment of record type is OK
7828 if not Known_Alignment (Rec)
7829 or else (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
7834 -- All tests passed, component is addressable
7839 --------------------------
7840 -- Reason_Bad_Component --
7841 --------------------------
7843 procedure Reason_Bad_Component (C : Entity_Id) is
7844 Rec : constant Entity_Id := Scope (C);
7845 Ctyp : constant Entity_Id := Etype (C);
7848 -- If component clause present assume that's the problem
7850 if Present (Component_Clause (C)) then
7851 Error_Msg_Sloc := Sloc (Component_Clause (C));
7852 Error_Msg_N ("\because of Component_Clause#", N);
7856 -- If pragma Pack clause present, assume that's the problem
7858 if Is_Packed (Rec) then
7859 P := Get_Rep_Pragma (Rec, Name_Pack);
7862 Error_Msg_Sloc := Sloc (P);
7863 Error_Msg_N ("\because of pragma Pack#", N);
7868 -- See if record has bad alignment clause
7870 if Has_Alignment_Clause (Rec)
7871 and then Known_Alignment (Rec)
7872 and then (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
7874 P := Get_Attribute_Definition_Clause (Rec, Attribute_Alignment);
7877 Error_Msg_Sloc := Sloc (P);
7878 Error_Msg_N ("\because of Alignment clause#", N);
7882 -- Couldn't find a reason, so return without a message
7885 end Reason_Bad_Component;
7887 -- Start of processing for Validate_Independence
7890 for J in Independence_Checks.First .. Independence_Checks.Last loop
7891 N := Independence_Checks.Table (J).N;
7892 E := Independence_Checks.Table (J).E;
7893 IC := Pragma_Name (N) = Name_Independent_Components;
7895 -- Deal with component case
7897 if Ekind (E) = E_Discriminant or else Ekind (E) = E_Component then
7898 if not OK_Component (E) then
7900 Reason_Bad_Component (E);
7905 -- Deal with record with Independent_Components
7907 if IC and then Is_Record_Type (E) then
7908 Comp := First_Component_Or_Discriminant (E);
7909 while Present (Comp) loop
7910 if not OK_Component (Comp) then
7912 Reason_Bad_Component (Comp);
7916 Next_Component_Or_Discriminant (Comp);
7920 -- Deal with address clause case
7922 if Is_Object (E) then
7923 Addr := Address_Clause (E);
7925 if Present (Addr) then
7927 Error_Msg_Sloc := Sloc (Addr);
7928 Error_Msg_N ("\because of Address clause#", N);
7933 -- Deal with independent components for array type
7935 if IC and then Is_Array_Type (E) then
7936 Check_Array_Type (E);
7939 -- Deal with independent components for array object
7941 if IC and then Is_Object (E) and then Is_Array_Type (Etype (E)) then
7942 Check_Array_Type (Etype (E));
7947 end Validate_Independence;
7949 -----------------------------------
7950 -- Validate_Unchecked_Conversion --
7951 -----------------------------------
7953 procedure Validate_Unchecked_Conversion
7955 Act_Unit : Entity_Id)
7962 -- Obtain source and target types. Note that we call Ancestor_Subtype
7963 -- here because the processing for generic instantiation always makes
7964 -- subtypes, and we want the original frozen actual types.
7966 -- If we are dealing with private types, then do the check on their
7967 -- fully declared counterparts if the full declarations have been
7968 -- encountered (they don't have to be visible, but they must exist!)
7970 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
7972 if Is_Private_Type (Source)
7973 and then Present (Underlying_Type (Source))
7975 Source := Underlying_Type (Source);
7978 Target := Ancestor_Subtype (Etype (Act_Unit));
7980 -- If either type is generic, the instantiation happens within a generic
7981 -- unit, and there is nothing to check. The proper check
7982 -- will happen when the enclosing generic is instantiated.
7984 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
7988 if Is_Private_Type (Target)
7989 and then Present (Underlying_Type (Target))
7991 Target := Underlying_Type (Target);
7994 -- Source may be unconstrained array, but not target
7996 if Is_Array_Type (Target)
7997 and then not Is_Constrained (Target)
8000 ("unchecked conversion to unconstrained array not allowed", N);
8004 -- Warn if conversion between two different convention pointers
8006 if Is_Access_Type (Target)
8007 and then Is_Access_Type (Source)
8008 and then Convention (Target) /= Convention (Source)
8009 and then Warn_On_Unchecked_Conversion
8011 -- Give warnings for subprogram pointers only on most targets. The
8012 -- exception is VMS, where data pointers can have different lengths
8013 -- depending on the pointer convention.
8015 if Is_Access_Subprogram_Type (Target)
8016 or else Is_Access_Subprogram_Type (Source)
8017 or else OpenVMS_On_Target
8020 ("?conversion between pointers with different conventions!", N);
8024 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
8025 -- warning when compiling GNAT-related sources.
8027 if Warn_On_Unchecked_Conversion
8028 and then not In_Predefined_Unit (N)
8029 and then RTU_Loaded (Ada_Calendar)
8031 (Chars (Source) = Name_Time
8033 Chars (Target) = Name_Time)
8035 -- If Ada.Calendar is loaded and the name of one of the operands is
8036 -- Time, there is a good chance that this is Ada.Calendar.Time.
8039 Calendar_Time : constant Entity_Id :=
8040 Full_View (RTE (RO_CA_Time));
8042 pragma Assert (Present (Calendar_Time));
8044 if Source = Calendar_Time
8045 or else Target = Calendar_Time
8048 ("?representation of 'Time values may change between " &
8049 "'G'N'A'T versions", N);
8054 -- Make entry in unchecked conversion table for later processing by
8055 -- Validate_Unchecked_Conversions, which will check sizes and alignments
8056 -- (using values set by the back-end where possible). This is only done
8057 -- if the appropriate warning is active.
8059 if Warn_On_Unchecked_Conversion then
8060 Unchecked_Conversions.Append
8061 (New_Val => UC_Entry'
8066 -- If both sizes are known statically now, then back end annotation
8067 -- is not required to do a proper check but if either size is not
8068 -- known statically, then we need the annotation.
8070 if Known_Static_RM_Size (Source)
8071 and then Known_Static_RM_Size (Target)
8075 Back_Annotate_Rep_Info := True;
8079 -- If unchecked conversion to access type, and access type is declared
8080 -- in the same unit as the unchecked conversion, then set the
8081 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
8084 if Is_Access_Type (Target) and then
8085 In_Same_Source_Unit (Target, N)
8087 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
8090 -- Generate N_Validate_Unchecked_Conversion node for back end in
8091 -- case the back end needs to perform special validation checks.
8093 -- Shouldn't this be in Exp_Ch13, since the check only gets done
8094 -- if we have full expansion and the back end is called ???
8097 Make_Validate_Unchecked_Conversion (Sloc (N));
8098 Set_Source_Type (Vnode, Source);
8099 Set_Target_Type (Vnode, Target);
8101 -- If the unchecked conversion node is in a list, just insert before it.
8102 -- If not we have some strange case, not worth bothering about.
8104 if Is_List_Member (N) then
8105 Insert_After (N, Vnode);
8107 end Validate_Unchecked_Conversion;
8109 ------------------------------------
8110 -- Validate_Unchecked_Conversions --
8111 ------------------------------------
8113 procedure Validate_Unchecked_Conversions is
8115 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
8117 T : UC_Entry renames Unchecked_Conversions.Table (N);
8119 Eloc : constant Source_Ptr := T.Eloc;
8120 Source : constant Entity_Id := T.Source;
8121 Target : constant Entity_Id := T.Target;
8127 -- This validation check, which warns if we have unequal sizes for
8128 -- unchecked conversion, and thus potentially implementation
8129 -- dependent semantics, is one of the few occasions on which we
8130 -- use the official RM size instead of Esize. See description in
8131 -- Einfo "Handling of Type'Size Values" for details.
8133 if Serious_Errors_Detected = 0
8134 and then Known_Static_RM_Size (Source)
8135 and then Known_Static_RM_Size (Target)
8137 -- Don't do the check if warnings off for either type, note the
8138 -- deliberate use of OR here instead of OR ELSE to get the flag
8139 -- Warnings_Off_Used set for both types if appropriate.
8141 and then not (Has_Warnings_Off (Source)
8143 Has_Warnings_Off (Target))
8145 Source_Siz := RM_Size (Source);
8146 Target_Siz := RM_Size (Target);
8148 if Source_Siz /= Target_Siz then
8150 ("?types for unchecked conversion have different sizes!",
8153 if All_Errors_Mode then
8154 Error_Msg_Name_1 := Chars (Source);
8155 Error_Msg_Uint_1 := Source_Siz;
8156 Error_Msg_Name_2 := Chars (Target);
8157 Error_Msg_Uint_2 := Target_Siz;
8158 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
8160 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
8162 if Is_Discrete_Type (Source)
8163 and then Is_Discrete_Type (Target)
8165 if Source_Siz > Target_Siz then
8167 ("\?^ high order bits of source will be ignored!",
8170 elsif Is_Unsigned_Type (Source) then
8172 ("\?source will be extended with ^ high order " &
8173 "zero bits?!", Eloc);
8177 ("\?source will be extended with ^ high order " &
8182 elsif Source_Siz < Target_Siz then
8183 if Is_Discrete_Type (Target) then
8184 if Bytes_Big_Endian then
8186 ("\?target value will include ^ undefined " &
8191 ("\?target value will include ^ undefined " &
8198 ("\?^ trailing bits of target value will be " &
8199 "undefined!", Eloc);
8202 else pragma Assert (Source_Siz > Target_Siz);
8204 ("\?^ trailing bits of source will be ignored!",
8211 -- If both types are access types, we need to check the alignment.
8212 -- If the alignment of both is specified, we can do it here.
8214 if Serious_Errors_Detected = 0
8215 and then Ekind (Source) in Access_Kind
8216 and then Ekind (Target) in Access_Kind
8217 and then Target_Strict_Alignment
8218 and then Present (Designated_Type (Source))
8219 and then Present (Designated_Type (Target))
8222 D_Source : constant Entity_Id := Designated_Type (Source);
8223 D_Target : constant Entity_Id := Designated_Type (Target);
8226 if Known_Alignment (D_Source)
8227 and then Known_Alignment (D_Target)
8230 Source_Align : constant Uint := Alignment (D_Source);
8231 Target_Align : constant Uint := Alignment (D_Target);
8234 if Source_Align < Target_Align
8235 and then not Is_Tagged_Type (D_Source)
8237 -- Suppress warning if warnings suppressed on either
8238 -- type or either designated type. Note the use of
8239 -- OR here instead of OR ELSE. That is intentional,
8240 -- we would like to set flag Warnings_Off_Used in
8241 -- all types for which warnings are suppressed.
8243 and then not (Has_Warnings_Off (D_Source)
8245 Has_Warnings_Off (D_Target)
8247 Has_Warnings_Off (Source)
8249 Has_Warnings_Off (Target))
8251 Error_Msg_Uint_1 := Target_Align;
8252 Error_Msg_Uint_2 := Source_Align;
8253 Error_Msg_Node_1 := D_Target;
8254 Error_Msg_Node_2 := D_Source;
8256 ("?alignment of & (^) is stricter than " &
8257 "alignment of & (^)!", Eloc);
8259 ("\?resulting access value may have invalid " &
8260 "alignment!", Eloc);
8268 end Validate_Unchecked_Conversions;
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