1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Aspects; use Aspects;
27 with Atree; use Atree;
28 with Checks; use Checks;
29 with Einfo; use Einfo;
30 with Elists; use Elists;
31 with Errout; use Errout;
32 with Exp_Disp; use Exp_Disp;
33 with Exp_Tss; use Exp_Tss;
34 with Exp_Util; use Exp_Util;
36 with Lib.Xref; use Lib.Xref;
37 with Namet; use Namet;
38 with Nlists; use Nlists;
39 with Nmake; use Nmake;
41 with Restrict; use Restrict;
42 with Rident; use Rident;
43 with Rtsfind; use Rtsfind;
45 with Sem_Aux; use Sem_Aux;
46 with Sem_Ch3; use Sem_Ch3;
47 with Sem_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 (^) "
443 & "('R'M 13.4.1(10))",
447 Error_Msg_Uint_1 := Fbit;
449 ("\and first bit (^) is non-zero "
450 & "('R'M 13.4.1(10))",
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 access type. Then
699 -- one 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#",
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 -- Construct the pragma
1170 Pragma_Argument_Associations =>
1171 New_List (Ent, Relocate_Node (Expr)),
1172 Class_Present => Class_Present (Aspect),
1173 Pragma_Identifier =>
1174 Make_Identifier (Sloc (Id), Name_Invariant));
1176 -- Add message unless exception messages are suppressed
1178 if not Opt.Exception_Locations_Suppressed then
1179 Append_To (Pragma_Argument_Associations (Aitem),
1180 Make_Pragma_Argument_Association (Eloc,
1181 Chars => Name_Message,
1183 Make_String_Literal (Eloc,
1184 Strval => "failed invariant from "
1185 & Build_Location_String (Eloc))));
1188 Set_From_Aspect_Specification (Aitem, True);
1189 Set_Is_Delayed_Aspect (Aspect);
1191 -- For Invariant case, insert immediately after the entity
1192 -- declaration. We do not have to worry about delay issues
1193 -- since the pragma processing takes care of this.
1195 Insert_After (N, Aitem);
1198 -- Predicate aspects generate a corresponding pragma with a
1199 -- first argument that is the entity, and the second argument
1200 -- is the expression.
1202 when Aspect_Dynamic_Predicate |
1204 Aspect_Static_Predicate =>
1206 -- Construct the pragma (always a pragma Predicate, with
1207 -- flags recording whether
1211 Pragma_Argument_Associations =>
1212 New_List (Ent, Relocate_Node (Expr)),
1213 Class_Present => Class_Present (Aspect),
1214 Pragma_Identifier =>
1215 Make_Identifier (Sloc (Id), Name_Predicate));
1217 Set_From_Aspect_Specification (Aitem, True);
1219 -- Set special flags for dynamic/static cases
1221 if A_Id = Aspect_Dynamic_Predicate then
1222 Set_From_Dynamic_Predicate (Aitem);
1223 elsif A_Id = Aspect_Static_Predicate then
1224 Set_From_Static_Predicate (Aitem);
1227 -- Make sure we have a freeze node (it might otherwise be
1228 -- missing in cases like subtype X is Y, and we would not
1229 -- have a place to build the predicate function).
1231 Set_Has_Predicates (E);
1232 Ensure_Freeze_Node (E);
1233 Set_Is_Delayed_Aspect (Aspect);
1234 Delay_Required := True;
1237 -- If a delay is required, we delay the freeze (not much point in
1238 -- delaying the aspect if we don't delay the freeze!). The pragma
1239 -- or attribute clause if there is one is then attached to the
1240 -- aspect specification which is placed in the rep item list.
1242 if Delay_Required then
1243 if Present (Aitem) then
1244 Set_From_Aspect_Specification (Aitem, True);
1245 Set_Is_Delayed_Aspect (Aitem);
1246 Set_Aspect_Rep_Item (Aspect, Aitem);
1249 Ensure_Freeze_Node (E);
1250 Set_Has_Delayed_Aspects (E);
1251 Record_Rep_Item (E, Aspect);
1253 -- If no delay required, insert the pragma/clause in the tree
1256 Set_From_Aspect_Specification (Aitem, True);
1258 -- If this is a compilation unit, we will put the pragma in
1259 -- the Pragmas_After list of the N_Compilation_Unit_Aux node.
1261 if Nkind (Parent (Ins_Node)) = N_Compilation_Unit then
1263 Aux : constant Node_Id :=
1264 Aux_Decls_Node (Parent (Ins_Node));
1267 pragma Assert (Nkind (Aux) = N_Compilation_Unit_Aux);
1269 if No (Pragmas_After (Aux)) then
1270 Set_Pragmas_After (Aux, Empty_List);
1273 -- For Pre_Post put at start of list, otherwise at end
1275 if A_Id in Pre_Post_Aspects then
1276 Prepend (Aitem, Pragmas_After (Aux));
1278 Append (Aitem, Pragmas_After (Aux));
1282 -- Here if not compilation unit case
1285 -- For Pre/Post cases, insert immediately after the entity
1286 -- declaration, since that is the required pragma placement.
1288 if A_Id in Pre_Post_Aspects then
1289 Insert_After (N, Aitem);
1291 -- For all other cases, insert in sequence
1294 Insert_After (Ins_Node, Aitem);
1303 end loop Aspect_Loop;
1304 end Analyze_Aspect_Specifications;
1306 -----------------------
1307 -- Analyze_At_Clause --
1308 -----------------------
1310 -- An at clause is replaced by the corresponding Address attribute
1311 -- definition clause that is the preferred approach in Ada 95.
1313 procedure Analyze_At_Clause (N : Node_Id) is
1314 CS : constant Boolean := Comes_From_Source (N);
1317 -- This is an obsolescent feature
1319 Check_Restriction (No_Obsolescent_Features, N);
1321 if Warn_On_Obsolescent_Feature then
1323 ("at clause is an obsolescent feature (RM J.7(2))?", N);
1325 ("\use address attribute definition clause instead?", N);
1328 -- Rewrite as address clause
1331 Make_Attribute_Definition_Clause (Sloc (N),
1332 Name => Identifier (N),
1333 Chars => Name_Address,
1334 Expression => Expression (N)));
1336 -- We preserve Comes_From_Source, since logically the clause still
1337 -- comes from the source program even though it is changed in form.
1339 Set_Comes_From_Source (N, CS);
1341 -- Analyze rewritten clause
1343 Analyze_Attribute_Definition_Clause (N);
1344 end Analyze_At_Clause;
1346 -----------------------------------------
1347 -- Analyze_Attribute_Definition_Clause --
1348 -----------------------------------------
1350 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
1351 Loc : constant Source_Ptr := Sloc (N);
1352 Nam : constant Node_Id := Name (N);
1353 Attr : constant Name_Id := Chars (N);
1354 Expr : constant Node_Id := Expression (N);
1355 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
1358 -- The entity of Nam after it is analyzed. In the case of an incomplete
1359 -- type, this is the underlying type.
1362 -- The underlying entity to which the attribute applies. Generally this
1363 -- is the Underlying_Type of Ent, except in the case where the clause
1364 -- applies to full view of incomplete type or private type in which case
1365 -- U_Ent is just a copy of Ent.
1367 FOnly : Boolean := False;
1368 -- Reset to True for subtype specific attribute (Alignment, Size)
1369 -- and for stream attributes, i.e. those cases where in the call
1370 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
1371 -- rules are checked. Note that the case of stream attributes is not
1372 -- clear from the RM, but see AI95-00137. Also, the RM seems to
1373 -- disallow Storage_Size for derived task types, but that is also
1374 -- clearly unintentional.
1376 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
1377 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
1378 -- definition clauses.
1380 function Duplicate_Clause return Boolean;
1381 -- This routine checks if the aspect for U_Ent being given by attribute
1382 -- definition clause N is for an aspect that has already been specified,
1383 -- and if so gives an error message. If there is a duplicate, True is
1384 -- returned, otherwise if there is no error, False is returned.
1386 -----------------------------------
1387 -- Analyze_Stream_TSS_Definition --
1388 -----------------------------------
1390 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
1391 Subp : Entity_Id := Empty;
1396 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
1397 -- True for Read attribute, false for other attributes
1399 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
1400 -- Return true if the entity is a subprogram with an appropriate
1401 -- profile for the attribute being defined.
1403 ----------------------
1404 -- Has_Good_Profile --
1405 ----------------------
1407 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
1409 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
1410 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
1411 (False => E_Procedure, True => E_Function);
1415 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
1419 F := First_Formal (Subp);
1422 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
1423 or else Designated_Type (Etype (F)) /=
1424 Class_Wide_Type (RTE (RE_Root_Stream_Type))
1429 if not Is_Function then
1433 Expected_Mode : constant array (Boolean) of Entity_Kind :=
1434 (False => E_In_Parameter,
1435 True => E_Out_Parameter);
1437 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
1445 Typ := Etype (Subp);
1448 return Base_Type (Typ) = Base_Type (Ent)
1449 and then No (Next_Formal (F));
1450 end Has_Good_Profile;
1452 -- Start of processing for Analyze_Stream_TSS_Definition
1457 if not Is_Type (U_Ent) then
1458 Error_Msg_N ("local name must be a subtype", Nam);
1462 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
1464 -- If Pnam is present, it can be either inherited from an ancestor
1465 -- type (in which case it is legal to redefine it for this type), or
1466 -- be a previous definition of the attribute for the same type (in
1467 -- which case it is illegal).
1469 -- In the first case, it will have been analyzed already, and we
1470 -- can check that its profile does not match the expected profile
1471 -- for a stream attribute of U_Ent. In the second case, either Pnam
1472 -- has been analyzed (and has the expected profile), or it has not
1473 -- been analyzed yet (case of a type that has not been frozen yet
1474 -- and for which the stream attribute has been set using Set_TSS).
1477 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
1479 Error_Msg_Sloc := Sloc (Pnam);
1480 Error_Msg_Name_1 := Attr;
1481 Error_Msg_N ("% attribute already defined #", Nam);
1487 if Is_Entity_Name (Expr) then
1488 if not Is_Overloaded (Expr) then
1489 if Has_Good_Profile (Entity (Expr)) then
1490 Subp := Entity (Expr);
1494 Get_First_Interp (Expr, I, It);
1495 while Present (It.Nam) loop
1496 if Has_Good_Profile (It.Nam) then
1501 Get_Next_Interp (I, It);
1506 if Present (Subp) then
1507 if Is_Abstract_Subprogram (Subp) then
1508 Error_Msg_N ("stream subprogram must not be abstract", Expr);
1512 Set_Entity (Expr, Subp);
1513 Set_Etype (Expr, Etype (Subp));
1515 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
1518 Error_Msg_Name_1 := Attr;
1519 Error_Msg_N ("incorrect expression for% attribute", Expr);
1521 end Analyze_Stream_TSS_Definition;
1523 ----------------------
1524 -- Duplicate_Clause --
1525 ----------------------
1527 function Duplicate_Clause return Boolean is
1531 -- Nothing to do if this attribute definition clause comes from
1532 -- an aspect specification, since we could not be duplicating an
1533 -- explicit clause, and we dealt with the case of duplicated aspects
1534 -- in Analyze_Aspect_Specifications.
1536 if From_Aspect_Specification (N) then
1540 -- Otherwise current clause may duplicate previous clause or a
1541 -- previously given aspect specification for the same aspect.
1543 A := Get_Rep_Item_For_Entity (U_Ent, Chars (N));
1546 if Entity (A) = U_Ent then
1547 Error_Msg_Name_1 := Chars (N);
1548 Error_Msg_Sloc := Sloc (A);
1549 Error_Msg_NE ("aspect% for & previously given#", N, U_Ent);
1555 end Duplicate_Clause;
1557 -- Start of processing for Analyze_Attribute_Definition_Clause
1560 -- The following code is a defense against recursion. Not clear that
1561 -- this can happen legitimately, but perhaps some error situations
1562 -- can cause it, and we did see this recursion during testing.
1564 if Analyzed (N) then
1567 Set_Analyzed (N, True);
1570 -- Process Ignore_Rep_Clauses option (we also ignore rep clauses in
1571 -- CodePeer mode, since they are not relevant in that context).
1573 if Ignore_Rep_Clauses or CodePeer_Mode then
1576 -- The following should be ignored. They do not affect legality
1577 -- and may be target dependent. The basic idea of -gnatI is to
1578 -- ignore any rep clauses that may be target dependent but do not
1579 -- affect legality (except possibly to be rejected because they
1580 -- are incompatible with the compilation target).
1582 when Attribute_Alignment |
1583 Attribute_Bit_Order |
1584 Attribute_Component_Size |
1585 Attribute_Machine_Radix |
1586 Attribute_Object_Size |
1588 Attribute_Stream_Size |
1589 Attribute_Value_Size =>
1590 Rewrite (N, Make_Null_Statement (Sloc (N)));
1593 -- We do not want too ignore 'Small in CodePeer_Mode, since it
1594 -- has an impact on the exact computations performed.
1596 -- Perhaps 'Small should also not be ignored by
1597 -- Ignore_Rep_Clauses ???
1599 when Attribute_Small =>
1600 if Ignore_Rep_Clauses then
1601 Rewrite (N, Make_Null_Statement (Sloc (N)));
1605 -- The following should not be ignored, because in the first place
1606 -- they are reasonably portable, and should not cause problems in
1607 -- compiling code from another target, and also they do affect
1608 -- legality, e.g. failing to provide a stream attribute for a
1609 -- type may make a program illegal.
1611 when Attribute_External_Tag |
1615 Attribute_Storage_Pool |
1616 Attribute_Storage_Size |
1620 -- Other cases are errors ("attribute& cannot be set with
1621 -- definition clause"), which will be caught below.
1629 Ent := Entity (Nam);
1631 if Rep_Item_Too_Early (Ent, N) then
1635 -- Rep clause applies to full view of incomplete type or private type if
1636 -- we have one (if not, this is a premature use of the type). However,
1637 -- certain semantic checks need to be done on the specified entity (i.e.
1638 -- the private view), so we save it in Ent.
1640 if Is_Private_Type (Ent)
1641 and then Is_Derived_Type (Ent)
1642 and then not Is_Tagged_Type (Ent)
1643 and then No (Full_View (Ent))
1645 -- If this is a private type whose completion is a derivation from
1646 -- another private type, there is no full view, and the attribute
1647 -- belongs to the type itself, not its underlying parent.
1651 elsif Ekind (Ent) = E_Incomplete_Type then
1653 -- The attribute applies to the full view, set the entity of the
1654 -- attribute definition accordingly.
1656 Ent := Underlying_Type (Ent);
1658 Set_Entity (Nam, Ent);
1661 U_Ent := Underlying_Type (Ent);
1664 -- Complete other routine error checks
1666 if Etype (Nam) = Any_Type then
1669 elsif Scope (Ent) /= Current_Scope then
1670 Error_Msg_N ("entity must be declared in this scope", Nam);
1673 elsif No (U_Ent) then
1676 elsif Is_Type (U_Ent)
1677 and then not Is_First_Subtype (U_Ent)
1678 and then Id /= Attribute_Object_Size
1679 and then Id /= Attribute_Value_Size
1680 and then not From_At_Mod (N)
1682 Error_Msg_N ("cannot specify attribute for subtype", Nam);
1686 Set_Entity (N, U_Ent);
1688 -- Switch on particular attribute
1696 -- Address attribute definition clause
1698 when Attribute_Address => Address : begin
1700 -- A little error check, catch for X'Address use X'Address;
1702 if Nkind (Nam) = N_Identifier
1703 and then Nkind (Expr) = N_Attribute_Reference
1704 and then Attribute_Name (Expr) = Name_Address
1705 and then Nkind (Prefix (Expr)) = N_Identifier
1706 and then Chars (Nam) = Chars (Prefix (Expr))
1709 ("address for & is self-referencing", Prefix (Expr), Ent);
1713 -- Not that special case, carry on with analysis of expression
1715 Analyze_And_Resolve (Expr, RTE (RE_Address));
1717 -- Even when ignoring rep clauses we need to indicate that the
1718 -- entity has an address clause and thus it is legal to declare
1721 if Ignore_Rep_Clauses then
1722 if Ekind_In (U_Ent, E_Variable, E_Constant) then
1723 Record_Rep_Item (U_Ent, N);
1729 if Duplicate_Clause then
1732 -- Case of address clause for subprogram
1734 elsif Is_Subprogram (U_Ent) then
1735 if Has_Homonym (U_Ent) then
1737 ("address clause cannot be given " &
1738 "for overloaded subprogram",
1743 -- For subprograms, all address clauses are permitted, and we
1744 -- mark the subprogram as having a deferred freeze so that Gigi
1745 -- will not elaborate it too soon.
1747 -- Above needs more comments, what is too soon about???
1749 Set_Has_Delayed_Freeze (U_Ent);
1751 -- Case of address clause for entry
1753 elsif Ekind (U_Ent) = E_Entry then
1754 if Nkind (Parent (N)) = N_Task_Body then
1756 ("entry address must be specified in task spec", Nam);
1760 -- For entries, we require a constant address
1762 Check_Constant_Address_Clause (Expr, U_Ent);
1764 -- Special checks for task types
1766 if Is_Task_Type (Scope (U_Ent))
1767 and then Comes_From_Source (Scope (U_Ent))
1770 ("?entry address declared for entry in task type", N);
1772 ("\?only one task can be declared of this type", N);
1775 -- Entry address clauses are obsolescent
1777 Check_Restriction (No_Obsolescent_Features, N);
1779 if Warn_On_Obsolescent_Feature then
1781 ("attaching interrupt to task entry is an " &
1782 "obsolescent feature (RM J.7.1)?", N);
1784 ("\use interrupt procedure instead?", N);
1787 -- Case of an address clause for a controlled object which we
1788 -- consider to be erroneous.
1790 elsif Is_Controlled (Etype (U_Ent))
1791 or else Has_Controlled_Component (Etype (U_Ent))
1794 ("?controlled object& must not be overlaid", Nam, U_Ent);
1796 ("\?Program_Error will be raised at run time", Nam);
1797 Insert_Action (Declaration_Node (U_Ent),
1798 Make_Raise_Program_Error (Loc,
1799 Reason => PE_Overlaid_Controlled_Object));
1802 -- Case of address clause for a (non-controlled) object
1805 Ekind (U_Ent) = E_Variable
1807 Ekind (U_Ent) = E_Constant
1810 Expr : constant Node_Id := Expression (N);
1815 -- Exported variables cannot have an address clause, because
1816 -- this cancels the effect of the pragma Export.
1818 if Is_Exported (U_Ent) then
1820 ("cannot export object with address clause", Nam);
1824 Find_Overlaid_Entity (N, O_Ent, Off);
1826 -- Overlaying controlled objects is erroneous
1829 and then (Has_Controlled_Component (Etype (O_Ent))
1830 or else Is_Controlled (Etype (O_Ent)))
1833 ("?cannot overlay with controlled object", Expr);
1835 ("\?Program_Error will be raised at run time", Expr);
1836 Insert_Action (Declaration_Node (U_Ent),
1837 Make_Raise_Program_Error (Loc,
1838 Reason => PE_Overlaid_Controlled_Object));
1841 elsif Present (O_Ent)
1842 and then Ekind (U_Ent) = E_Constant
1843 and then not Is_Constant_Object (O_Ent)
1845 Error_Msg_N ("constant overlays a variable?", Expr);
1847 elsif Present (Renamed_Object (U_Ent)) then
1849 ("address clause not allowed"
1850 & " for a renaming declaration (RM 13.1(6))", Nam);
1853 -- Imported variables can have an address clause, but then
1854 -- the import is pretty meaningless except to suppress
1855 -- initializations, so we do not need such variables to
1856 -- be statically allocated (and in fact it causes trouble
1857 -- if the address clause is a local value).
1859 elsif Is_Imported (U_Ent) then
1860 Set_Is_Statically_Allocated (U_Ent, False);
1863 -- We mark a possible modification of a variable with an
1864 -- address clause, since it is likely aliasing is occurring.
1866 Note_Possible_Modification (Nam, Sure => False);
1868 -- Here we are checking for explicit overlap of one variable
1869 -- by another, and if we find this then mark the overlapped
1870 -- variable as also being volatile to prevent unwanted
1871 -- optimizations. This is a significant pessimization so
1872 -- avoid it when there is an offset, i.e. when the object
1873 -- is composite; they cannot be optimized easily anyway.
1876 and then Is_Object (O_Ent)
1879 Set_Treat_As_Volatile (O_Ent);
1882 -- Legality checks on the address clause for initialized
1883 -- objects is deferred until the freeze point, because
1884 -- a subsequent pragma might indicate that the object is
1885 -- imported and thus not initialized.
1887 Set_Has_Delayed_Freeze (U_Ent);
1889 -- If an initialization call has been generated for this
1890 -- object, it needs to be deferred to after the freeze node
1891 -- we have just now added, otherwise GIGI will see a
1892 -- reference to the variable (as actual to the IP call)
1893 -- before its definition.
1896 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1898 if Present (Init_Call) then
1900 Append_Freeze_Action (U_Ent, Init_Call);
1904 if Is_Exported (U_Ent) then
1906 ("& cannot be exported if an address clause is given",
1909 ("\define and export a variable " &
1910 "that holds its address instead",
1914 -- Entity has delayed freeze, so we will generate an
1915 -- alignment check at the freeze point unless suppressed.
1917 if not Range_Checks_Suppressed (U_Ent)
1918 and then not Alignment_Checks_Suppressed (U_Ent)
1920 Set_Check_Address_Alignment (N);
1923 -- Kill the size check code, since we are not allocating
1924 -- the variable, it is somewhere else.
1926 Kill_Size_Check_Code (U_Ent);
1928 -- If the address clause is of the form:
1930 -- for Y'Address use X'Address
1934 -- Const : constant Address := X'Address;
1936 -- for Y'Address use Const;
1938 -- then we make an entry in the table for checking the size
1939 -- and alignment of the overlaying variable. We defer this
1940 -- check till after code generation to take full advantage
1941 -- of the annotation done by the back end. This entry is
1942 -- only made if the address clause comes from source.
1944 -- If the entity has a generic type, the check will be
1945 -- performed in the instance if the actual type justifies
1946 -- it, and we do not insert the clause in the table to
1947 -- prevent spurious warnings.
1949 if Address_Clause_Overlay_Warnings
1950 and then Comes_From_Source (N)
1951 and then Present (O_Ent)
1952 and then Is_Object (O_Ent)
1954 if not Is_Generic_Type (Etype (U_Ent)) then
1955 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1958 -- If variable overlays a constant view, and we are
1959 -- warning on overlays, then mark the variable as
1960 -- overlaying a constant (we will give warnings later
1961 -- if this variable is assigned).
1963 if Is_Constant_Object (O_Ent)
1964 and then Ekind (U_Ent) = E_Variable
1966 Set_Overlays_Constant (U_Ent);
1971 -- Not a valid entity for an address clause
1974 Error_Msg_N ("address cannot be given for &", Nam);
1982 -- Alignment attribute definition clause
1984 when Attribute_Alignment => Alignment : declare
1985 Align : constant Uint := Get_Alignment_Value (Expr);
1990 if not Is_Type (U_Ent)
1991 and then Ekind (U_Ent) /= E_Variable
1992 and then Ekind (U_Ent) /= E_Constant
1994 Error_Msg_N ("alignment cannot be given for &", Nam);
1996 elsif Duplicate_Clause then
1999 elsif Align /= No_Uint then
2000 Set_Has_Alignment_Clause (U_Ent);
2001 Set_Alignment (U_Ent, Align);
2003 -- For an array type, U_Ent is the first subtype. In that case,
2004 -- also set the alignment of the anonymous base type so that
2005 -- other subtypes (such as the itypes for aggregates of the
2006 -- type) also receive the expected alignment.
2008 if Is_Array_Type (U_Ent) then
2009 Set_Alignment (Base_Type (U_Ent), Align);
2018 -- Bit_Order attribute definition clause
2020 when Attribute_Bit_Order => Bit_Order : declare
2022 if not Is_Record_Type (U_Ent) then
2024 ("Bit_Order can only be defined for record type", Nam);
2026 elsif Duplicate_Clause then
2030 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
2032 if Etype (Expr) = Any_Type then
2035 elsif not Is_Static_Expression (Expr) then
2036 Flag_Non_Static_Expr
2037 ("Bit_Order requires static expression!", Expr);
2040 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
2041 Set_Reverse_Bit_Order (U_Ent, True);
2047 --------------------
2048 -- Component_Size --
2049 --------------------
2051 -- Component_Size attribute definition clause
2053 when Attribute_Component_Size => Component_Size_Case : declare
2054 Csize : constant Uint := Static_Integer (Expr);
2058 New_Ctyp : Entity_Id;
2062 if not Is_Array_Type (U_Ent) then
2063 Error_Msg_N ("component size requires array type", Nam);
2067 Btype := Base_Type (U_Ent);
2068 Ctyp := Component_Type (Btype);
2070 if Duplicate_Clause then
2073 elsif Rep_Item_Too_Early (Btype, N) then
2076 elsif Csize /= No_Uint then
2077 Check_Size (Expr, Ctyp, Csize, Biased);
2079 -- For the biased case, build a declaration for a subtype that
2080 -- will be used to represent the biased subtype that reflects
2081 -- the biased representation of components. We need the subtype
2082 -- to get proper conversions on referencing elements of the
2083 -- array. Note: component size clauses are ignored in VM mode.
2085 if VM_Target = No_VM then
2088 Make_Defining_Identifier (Loc,
2090 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
2093 Make_Subtype_Declaration (Loc,
2094 Defining_Identifier => New_Ctyp,
2095 Subtype_Indication =>
2096 New_Occurrence_Of (Component_Type (Btype), Loc));
2098 Set_Parent (Decl, N);
2099 Analyze (Decl, Suppress => All_Checks);
2101 Set_Has_Delayed_Freeze (New_Ctyp, False);
2102 Set_Esize (New_Ctyp, Csize);
2103 Set_RM_Size (New_Ctyp, Csize);
2104 Init_Alignment (New_Ctyp);
2105 Set_Is_Itype (New_Ctyp, True);
2106 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
2108 Set_Component_Type (Btype, New_Ctyp);
2109 Set_Biased (New_Ctyp, N, "component size clause");
2112 Set_Component_Size (Btype, Csize);
2114 -- For VM case, we ignore component size clauses
2117 -- Give a warning unless we are in GNAT mode, in which case
2118 -- the warning is suppressed since it is not useful.
2120 if not GNAT_Mode then
2122 ("?component size ignored in this configuration", N);
2126 -- Deal with warning on overridden size
2128 if Warn_On_Overridden_Size
2129 and then Has_Size_Clause (Ctyp)
2130 and then RM_Size (Ctyp) /= Csize
2133 ("?component size overrides size clause for&",
2137 Set_Has_Component_Size_Clause (Btype, True);
2138 Set_Has_Non_Standard_Rep (Btype, True);
2140 end Component_Size_Case;
2146 when Attribute_External_Tag => External_Tag :
2148 if not Is_Tagged_Type (U_Ent) then
2149 Error_Msg_N ("should be a tagged type", Nam);
2152 if Duplicate_Clause then
2156 Analyze_And_Resolve (Expr, Standard_String);
2158 if not Is_Static_Expression (Expr) then
2159 Flag_Non_Static_Expr
2160 ("static string required for tag name!", Nam);
2163 if VM_Target = No_VM then
2164 Set_Has_External_Tag_Rep_Clause (U_Ent);
2166 Error_Msg_Name_1 := Attr;
2168 ("% attribute unsupported in this configuration", Nam);
2171 if not Is_Library_Level_Entity (U_Ent) then
2173 ("?non-unique external tag supplied for &", N, U_Ent);
2175 ("?\same external tag applies to all subprogram calls", N);
2177 ("?\corresponding internal tag cannot be obtained", N);
2186 when Attribute_Input =>
2187 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
2188 Set_Has_Specified_Stream_Input (Ent);
2194 -- Machine radix attribute definition clause
2196 when Attribute_Machine_Radix => Machine_Radix : declare
2197 Radix : constant Uint := Static_Integer (Expr);
2200 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
2201 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
2203 elsif Duplicate_Clause then
2206 elsif Radix /= No_Uint then
2207 Set_Has_Machine_Radix_Clause (U_Ent);
2208 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
2212 elsif Radix = 10 then
2213 Set_Machine_Radix_10 (U_Ent);
2215 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
2224 -- Object_Size attribute definition clause
2226 when Attribute_Object_Size => Object_Size : declare
2227 Size : constant Uint := Static_Integer (Expr);
2230 pragma Warnings (Off, Biased);
2233 if not Is_Type (U_Ent) then
2234 Error_Msg_N ("Object_Size cannot be given for &", Nam);
2236 elsif Duplicate_Clause then
2240 Check_Size (Expr, U_Ent, Size, Biased);
2248 UI_Mod (Size, 64) /= 0
2251 ("Object_Size must be 8, 16, 32, or multiple of 64",
2255 Set_Esize (U_Ent, Size);
2256 Set_Has_Object_Size_Clause (U_Ent);
2257 Alignment_Check_For_Esize_Change (U_Ent);
2265 when Attribute_Output =>
2266 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
2267 Set_Has_Specified_Stream_Output (Ent);
2273 when Attribute_Read =>
2274 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
2275 Set_Has_Specified_Stream_Read (Ent);
2281 -- Size attribute definition clause
2283 when Attribute_Size => Size : declare
2284 Size : constant Uint := Static_Integer (Expr);
2291 if Duplicate_Clause then
2294 elsif not Is_Type (U_Ent)
2295 and then Ekind (U_Ent) /= E_Variable
2296 and then Ekind (U_Ent) /= E_Constant
2298 Error_Msg_N ("size cannot be given for &", Nam);
2300 elsif Is_Array_Type (U_Ent)
2301 and then not Is_Constrained (U_Ent)
2304 ("size cannot be given for unconstrained array", Nam);
2306 elsif Size /= No_Uint then
2307 if VM_Target /= No_VM and then not GNAT_Mode then
2309 -- Size clause is not handled properly on VM targets.
2310 -- Display a warning unless we are in GNAT mode, in which
2311 -- case this is useless.
2314 ("?size clauses are ignored in this configuration", N);
2317 if Is_Type (U_Ent) then
2320 Etyp := Etype (U_Ent);
2323 -- Check size, note that Gigi is in charge of checking that the
2324 -- size of an array or record type is OK. Also we do not check
2325 -- the size in the ordinary fixed-point case, since it is too
2326 -- early to do so (there may be subsequent small clause that
2327 -- affects the size). We can check the size if a small clause
2328 -- has already been given.
2330 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
2331 or else Has_Small_Clause (U_Ent)
2333 Check_Size (Expr, Etyp, Size, Biased);
2334 Set_Biased (U_Ent, N, "size clause", Biased);
2337 -- For types set RM_Size and Esize if possible
2339 if Is_Type (U_Ent) then
2340 Set_RM_Size (U_Ent, Size);
2342 -- For scalar types, increase Object_Size to power of 2, but
2343 -- not less than a storage unit in any case (i.e., normally
2344 -- this means it will be byte addressable).
2346 if Is_Scalar_Type (U_Ent) then
2347 if Size <= System_Storage_Unit then
2348 Init_Esize (U_Ent, System_Storage_Unit);
2349 elsif Size <= 16 then
2350 Init_Esize (U_Ent, 16);
2351 elsif Size <= 32 then
2352 Init_Esize (U_Ent, 32);
2354 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
2357 -- For all other types, object size = value size. The
2358 -- backend will adjust as needed.
2361 Set_Esize (U_Ent, Size);
2364 Alignment_Check_For_Esize_Change (U_Ent);
2366 -- For objects, set Esize only
2369 if Is_Elementary_Type (Etyp) then
2370 if Size /= System_Storage_Unit
2372 Size /= System_Storage_Unit * 2
2374 Size /= System_Storage_Unit * 4
2376 Size /= System_Storage_Unit * 8
2378 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
2379 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
2381 ("size for primitive object must be a power of 2"
2382 & " in the range ^-^", N);
2386 Set_Esize (U_Ent, Size);
2389 Set_Has_Size_Clause (U_Ent);
2397 -- Small attribute definition clause
2399 when Attribute_Small => Small : declare
2400 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
2404 Analyze_And_Resolve (Expr, Any_Real);
2406 if Etype (Expr) = Any_Type then
2409 elsif not Is_Static_Expression (Expr) then
2410 Flag_Non_Static_Expr
2411 ("small requires static expression!", Expr);
2415 Small := Expr_Value_R (Expr);
2417 if Small <= Ureal_0 then
2418 Error_Msg_N ("small value must be greater than zero", Expr);
2424 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
2426 ("small requires an ordinary fixed point type", Nam);
2428 elsif Has_Small_Clause (U_Ent) then
2429 Error_Msg_N ("small already given for &", Nam);
2431 elsif Small > Delta_Value (U_Ent) then
2433 ("small value must not be greater then delta value", Nam);
2436 Set_Small_Value (U_Ent, Small);
2437 Set_Small_Value (Implicit_Base, Small);
2438 Set_Has_Small_Clause (U_Ent);
2439 Set_Has_Small_Clause (Implicit_Base);
2440 Set_Has_Non_Standard_Rep (Implicit_Base);
2448 -- Storage_Pool attribute definition clause
2450 when Attribute_Storage_Pool => Storage_Pool : declare
2455 if Ekind (U_Ent) = E_Access_Subprogram_Type then
2457 ("storage pool cannot be given for access-to-subprogram type",
2462 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
2465 ("storage pool can only be given for access types", Nam);
2468 elsif Is_Derived_Type (U_Ent) then
2470 ("storage pool cannot be given for a derived access type",
2473 elsif Duplicate_Clause then
2476 elsif Present (Associated_Storage_Pool (U_Ent)) then
2477 Error_Msg_N ("storage pool already given for &", Nam);
2482 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
2484 if not Denotes_Variable (Expr) then
2485 Error_Msg_N ("storage pool must be a variable", Expr);
2489 if Nkind (Expr) = N_Type_Conversion then
2490 T := Etype (Expression (Expr));
2495 -- The Stack_Bounded_Pool is used internally for implementing
2496 -- access types with a Storage_Size. Since it only work properly
2497 -- when used on one specific type, we need to check that it is not
2498 -- hijacked improperly:
2500 -- type T is access Integer;
2501 -- for T'Storage_Size use n;
2502 -- type Q is access Float;
2503 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
2505 if RTE_Available (RE_Stack_Bounded_Pool)
2506 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
2508 Error_Msg_N ("non-shareable internal Pool", Expr);
2512 -- If the argument is a name that is not an entity name, then
2513 -- we construct a renaming operation to define an entity of
2514 -- type storage pool.
2516 if not Is_Entity_Name (Expr)
2517 and then Is_Object_Reference (Expr)
2519 Pool := Make_Temporary (Loc, 'P', Expr);
2522 Rnode : constant Node_Id :=
2523 Make_Object_Renaming_Declaration (Loc,
2524 Defining_Identifier => Pool,
2526 New_Occurrence_Of (Etype (Expr), Loc),
2530 Insert_Before (N, Rnode);
2532 Set_Associated_Storage_Pool (U_Ent, Pool);
2535 elsif Is_Entity_Name (Expr) then
2536 Pool := Entity (Expr);
2538 -- If pool is a renamed object, get original one. This can
2539 -- happen with an explicit renaming, and within instances.
2541 while Present (Renamed_Object (Pool))
2542 and then Is_Entity_Name (Renamed_Object (Pool))
2544 Pool := Entity (Renamed_Object (Pool));
2547 if Present (Renamed_Object (Pool))
2548 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
2549 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
2551 Pool := Entity (Expression (Renamed_Object (Pool)));
2554 Set_Associated_Storage_Pool (U_Ent, Pool);
2556 elsif Nkind (Expr) = N_Type_Conversion
2557 and then Is_Entity_Name (Expression (Expr))
2558 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
2560 Pool := Entity (Expression (Expr));
2561 Set_Associated_Storage_Pool (U_Ent, Pool);
2564 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
2573 -- Storage_Size attribute definition clause
2575 when Attribute_Storage_Size => Storage_Size : declare
2576 Btype : constant Entity_Id := Base_Type (U_Ent);
2580 if Is_Task_Type (U_Ent) then
2581 Check_Restriction (No_Obsolescent_Features, N);
2583 if Warn_On_Obsolescent_Feature then
2585 ("storage size clause for task is an " &
2586 "obsolescent feature (RM J.9)?", N);
2587 Error_Msg_N ("\use Storage_Size pragma instead?", N);
2593 if not Is_Access_Type (U_Ent)
2594 and then Ekind (U_Ent) /= E_Task_Type
2596 Error_Msg_N ("storage size cannot be given for &", Nam);
2598 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
2600 ("storage size cannot be given for a derived access type",
2603 elsif Duplicate_Clause then
2607 Analyze_And_Resolve (Expr, Any_Integer);
2609 if Is_Access_Type (U_Ent) then
2610 if Present (Associated_Storage_Pool (U_Ent)) then
2611 Error_Msg_N ("storage pool already given for &", Nam);
2615 if Is_OK_Static_Expression (Expr)
2616 and then Expr_Value (Expr) = 0
2618 Set_No_Pool_Assigned (Btype);
2621 else -- Is_Task_Type (U_Ent)
2622 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
2624 if Present (Sprag) then
2625 Error_Msg_Sloc := Sloc (Sprag);
2627 ("Storage_Size already specified#", Nam);
2632 Set_Has_Storage_Size_Clause (Btype);
2640 when Attribute_Stream_Size => Stream_Size : declare
2641 Size : constant Uint := Static_Integer (Expr);
2644 if Ada_Version <= Ada_95 then
2645 Check_Restriction (No_Implementation_Attributes, N);
2648 if Duplicate_Clause then
2651 elsif Is_Elementary_Type (U_Ent) then
2652 if Size /= System_Storage_Unit
2654 Size /= System_Storage_Unit * 2
2656 Size /= System_Storage_Unit * 4
2658 Size /= System_Storage_Unit * 8
2660 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
2662 ("stream size for elementary type must be a"
2663 & " power of 2 and at least ^", N);
2665 elsif RM_Size (U_Ent) > Size then
2666 Error_Msg_Uint_1 := RM_Size (U_Ent);
2668 ("stream size for elementary type must be a"
2669 & " power of 2 and at least ^", N);
2672 Set_Has_Stream_Size_Clause (U_Ent);
2675 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
2683 -- Value_Size attribute definition clause
2685 when Attribute_Value_Size => Value_Size : declare
2686 Size : constant Uint := Static_Integer (Expr);
2690 if not Is_Type (U_Ent) then
2691 Error_Msg_N ("Value_Size cannot be given for &", Nam);
2693 elsif Duplicate_Clause then
2696 elsif Is_Array_Type (U_Ent)
2697 and then not Is_Constrained (U_Ent)
2700 ("Value_Size cannot be given for unconstrained array", Nam);
2703 if Is_Elementary_Type (U_Ent) then
2704 Check_Size (Expr, U_Ent, Size, Biased);
2705 Set_Biased (U_Ent, N, "value size clause", Biased);
2708 Set_RM_Size (U_Ent, Size);
2716 when Attribute_Write =>
2717 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
2718 Set_Has_Specified_Stream_Write (Ent);
2720 -- All other attributes cannot be set
2724 ("attribute& cannot be set with definition clause", N);
2727 -- The test for the type being frozen must be performed after any
2728 -- expression the clause has been analyzed since the expression itself
2729 -- might cause freezing that makes the clause illegal.
2731 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
2734 end Analyze_Attribute_Definition_Clause;
2736 ----------------------------
2737 -- Analyze_Code_Statement --
2738 ----------------------------
2740 procedure Analyze_Code_Statement (N : Node_Id) is
2741 HSS : constant Node_Id := Parent (N);
2742 SBody : constant Node_Id := Parent (HSS);
2743 Subp : constant Entity_Id := Current_Scope;
2750 -- Analyze and check we get right type, note that this implements the
2751 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
2752 -- is the only way that Asm_Insn could possibly be visible.
2754 Analyze_And_Resolve (Expression (N));
2756 if Etype (Expression (N)) = Any_Type then
2758 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
2759 Error_Msg_N ("incorrect type for code statement", N);
2763 Check_Code_Statement (N);
2765 -- Make sure we appear in the handled statement sequence of a
2766 -- subprogram (RM 13.8(3)).
2768 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2769 or else Nkind (SBody) /= N_Subprogram_Body
2772 ("code statement can only appear in body of subprogram", N);
2776 -- Do remaining checks (RM 13.8(3)) if not already done
2778 if not Is_Machine_Code_Subprogram (Subp) then
2779 Set_Is_Machine_Code_Subprogram (Subp);
2781 -- No exception handlers allowed
2783 if Present (Exception_Handlers (HSS)) then
2785 ("exception handlers not permitted in machine code subprogram",
2786 First (Exception_Handlers (HSS)));
2789 -- No declarations other than use clauses and pragmas (we allow
2790 -- certain internally generated declarations as well).
2792 Decl := First (Declarations (SBody));
2793 while Present (Decl) loop
2794 DeclO := Original_Node (Decl);
2795 if Comes_From_Source (DeclO)
2796 and not Nkind_In (DeclO, N_Pragma,
2797 N_Use_Package_Clause,
2799 N_Implicit_Label_Declaration)
2802 ("this declaration not allowed in machine code subprogram",
2809 -- No statements other than code statements, pragmas, and labels.
2810 -- Again we allow certain internally generated statements.
2812 Stmt := First (Statements (HSS));
2813 while Present (Stmt) loop
2814 StmtO := Original_Node (Stmt);
2815 if Comes_From_Source (StmtO)
2816 and then not Nkind_In (StmtO, N_Pragma,
2821 ("this statement is not allowed in machine code subprogram",
2828 end Analyze_Code_Statement;
2830 -----------------------------------------------
2831 -- Analyze_Enumeration_Representation_Clause --
2832 -----------------------------------------------
2834 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2835 Ident : constant Node_Id := Identifier (N);
2836 Aggr : constant Node_Id := Array_Aggregate (N);
2837 Enumtype : Entity_Id;
2843 Err : Boolean := False;
2845 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2846 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2847 -- Allowed range of universal integer (= allowed range of enum lit vals)
2851 -- Minimum and maximum values of entries
2854 -- Pointer to node for literal providing max value
2857 if Ignore_Rep_Clauses then
2861 -- First some basic error checks
2864 Enumtype := Entity (Ident);
2866 if Enumtype = Any_Type
2867 or else Rep_Item_Too_Early (Enumtype, N)
2871 Enumtype := Underlying_Type (Enumtype);
2874 if not Is_Enumeration_Type (Enumtype) then
2876 ("enumeration type required, found}",
2877 Ident, First_Subtype (Enumtype));
2881 -- Ignore rep clause on generic actual type. This will already have
2882 -- been flagged on the template as an error, and this is the safest
2883 -- way to ensure we don't get a junk cascaded message in the instance.
2885 if Is_Generic_Actual_Type (Enumtype) then
2888 -- Type must be in current scope
2890 elsif Scope (Enumtype) /= Current_Scope then
2891 Error_Msg_N ("type must be declared in this scope", Ident);
2894 -- Type must be a first subtype
2896 elsif not Is_First_Subtype (Enumtype) then
2897 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2900 -- Ignore duplicate rep clause
2902 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2903 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2906 -- Don't allow rep clause for standard [wide_[wide_]]character
2908 elsif Is_Standard_Character_Type (Enumtype) then
2909 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2912 -- Check that the expression is a proper aggregate (no parentheses)
2914 elsif Paren_Count (Aggr) /= 0 then
2916 ("extra parentheses surrounding aggregate not allowed",
2920 -- All tests passed, so set rep clause in place
2923 Set_Has_Enumeration_Rep_Clause (Enumtype);
2924 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2927 -- Now we process the aggregate. Note that we don't use the normal
2928 -- aggregate code for this purpose, because we don't want any of the
2929 -- normal expansion activities, and a number of special semantic
2930 -- rules apply (including the component type being any integer type)
2932 Elit := First_Literal (Enumtype);
2934 -- First the positional entries if any
2936 if Present (Expressions (Aggr)) then
2937 Expr := First (Expressions (Aggr));
2938 while Present (Expr) loop
2940 Error_Msg_N ("too many entries in aggregate", Expr);
2944 Val := Static_Integer (Expr);
2946 -- Err signals that we found some incorrect entries processing
2947 -- the list. The final checks for completeness and ordering are
2948 -- skipped in this case.
2950 if Val = No_Uint then
2952 elsif Val < Lo or else Hi < Val then
2953 Error_Msg_N ("value outside permitted range", Expr);
2957 Set_Enumeration_Rep (Elit, Val);
2958 Set_Enumeration_Rep_Expr (Elit, Expr);
2964 -- Now process the named entries if present
2966 if Present (Component_Associations (Aggr)) then
2967 Assoc := First (Component_Associations (Aggr));
2968 while Present (Assoc) loop
2969 Choice := First (Choices (Assoc));
2971 if Present (Next (Choice)) then
2973 ("multiple choice not allowed here", Next (Choice));
2977 if Nkind (Choice) = N_Others_Choice then
2978 Error_Msg_N ("others choice not allowed here", Choice);
2981 elsif Nkind (Choice) = N_Range then
2982 -- ??? should allow zero/one element range here
2983 Error_Msg_N ("range not allowed here", Choice);
2987 Analyze_And_Resolve (Choice, Enumtype);
2989 if Is_Entity_Name (Choice)
2990 and then Is_Type (Entity (Choice))
2992 Error_Msg_N ("subtype name not allowed here", Choice);
2994 -- ??? should allow static subtype with zero/one entry
2996 elsif Etype (Choice) = Base_Type (Enumtype) then
2997 if not Is_Static_Expression (Choice) then
2998 Flag_Non_Static_Expr
2999 ("non-static expression used for choice!", Choice);
3003 Elit := Expr_Value_E (Choice);
3005 if Present (Enumeration_Rep_Expr (Elit)) then
3006 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
3008 ("representation for& previously given#",
3013 Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
3015 Expr := Expression (Assoc);
3016 Val := Static_Integer (Expr);
3018 if Val = No_Uint then
3021 elsif Val < Lo or else Hi < Val then
3022 Error_Msg_N ("value outside permitted range", Expr);
3026 Set_Enumeration_Rep (Elit, Val);
3035 -- Aggregate is fully processed. Now we check that a full set of
3036 -- representations was given, and that they are in range and in order.
3037 -- These checks are only done if no other errors occurred.
3043 Elit := First_Literal (Enumtype);
3044 while Present (Elit) loop
3045 if No (Enumeration_Rep_Expr (Elit)) then
3046 Error_Msg_NE ("missing representation for&!", N, Elit);
3049 Val := Enumeration_Rep (Elit);
3051 if Min = No_Uint then
3055 if Val /= No_Uint then
3056 if Max /= No_Uint and then Val <= Max then
3058 ("enumeration value for& not ordered!",
3059 Enumeration_Rep_Expr (Elit), Elit);
3062 Max_Node := Enumeration_Rep_Expr (Elit);
3066 -- If there is at least one literal whose representation is not
3067 -- equal to the Pos value, then note that this enumeration type
3068 -- has a non-standard representation.
3070 if Val /= Enumeration_Pos (Elit) then
3071 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
3078 -- Now set proper size information
3081 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
3084 if Has_Size_Clause (Enumtype) then
3086 -- All OK, if size is OK now
3088 if RM_Size (Enumtype) >= Minsize then
3092 -- Try if we can get by with biasing
3095 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
3097 -- Error message if even biasing does not work
3099 if RM_Size (Enumtype) < Minsize then
3100 Error_Msg_Uint_1 := RM_Size (Enumtype);
3101 Error_Msg_Uint_2 := Max;
3103 ("previously given size (^) is too small "
3104 & "for this value (^)", Max_Node);
3106 -- If biasing worked, indicate that we now have biased rep
3110 (Enumtype, Size_Clause (Enumtype), "size clause");
3115 Set_RM_Size (Enumtype, Minsize);
3116 Set_Enum_Esize (Enumtype);
3119 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
3120 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
3121 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
3125 -- We repeat the too late test in case it froze itself!
3127 if Rep_Item_Too_Late (Enumtype, N) then
3130 end Analyze_Enumeration_Representation_Clause;
3132 ----------------------------
3133 -- Analyze_Free_Statement --
3134 ----------------------------
3136 procedure Analyze_Free_Statement (N : Node_Id) is
3138 Analyze (Expression (N));
3139 end Analyze_Free_Statement;
3141 ---------------------------
3142 -- Analyze_Freeze_Entity --
3143 ---------------------------
3145 procedure Analyze_Freeze_Entity (N : Node_Id) is
3146 E : constant Entity_Id := Entity (N);
3149 -- Remember that we are processing a freezing entity. Required to
3150 -- ensure correct decoration of internal entities associated with
3151 -- interfaces (see New_Overloaded_Entity).
3153 Inside_Freezing_Actions := Inside_Freezing_Actions + 1;
3155 -- For tagged types covering interfaces add internal entities that link
3156 -- the primitives of the interfaces with the primitives that cover them.
3157 -- Note: These entities were originally generated only when generating
3158 -- code because their main purpose was to provide support to initialize
3159 -- the secondary dispatch tables. They are now generated also when
3160 -- compiling with no code generation to provide ASIS the relationship
3161 -- between interface primitives and tagged type primitives. They are
3162 -- also used to locate primitives covering interfaces when processing
3163 -- generics (see Derive_Subprograms).
3165 if Ada_Version >= Ada_2005
3166 and then Ekind (E) = E_Record_Type
3167 and then Is_Tagged_Type (E)
3168 and then not Is_Interface (E)
3169 and then Has_Interfaces (E)
3171 -- This would be a good common place to call the routine that checks
3172 -- overriding of interface primitives (and thus factorize calls to
3173 -- Check_Abstract_Overriding located at different contexts in the
3174 -- compiler). However, this is not possible because it causes
3175 -- spurious errors in case of late overriding.
3177 Add_Internal_Interface_Entities (E);
3182 if Ekind (E) = E_Record_Type
3183 and then Is_CPP_Class (E)
3184 and then Is_Tagged_Type (E)
3185 and then Tagged_Type_Expansion
3186 and then Expander_Active
3188 if CPP_Num_Prims (E) = 0 then
3190 -- If the CPP type has user defined components then it must import
3191 -- primitives from C++. This is required because if the C++ class
3192 -- has no primitives then the C++ compiler does not added the _tag
3193 -- component to the type.
3195 pragma Assert (Chars (First_Entity (E)) = Name_uTag);
3197 if First_Entity (E) /= Last_Entity (E) then
3199 ("?'C'P'P type must import at least one primitive from C++",
3204 -- Check that all its primitives are abstract or imported from C++.
3205 -- Check also availability of the C++ constructor.
3208 Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
3210 Error_Reported : Boolean := False;
3214 Elmt := First_Elmt (Primitive_Operations (E));
3215 while Present (Elmt) loop
3216 Prim := Node (Elmt);
3218 if Comes_From_Source (Prim) then
3219 if Is_Abstract_Subprogram (Prim) then
3222 elsif not Is_Imported (Prim)
3223 or else Convention (Prim) /= Convention_CPP
3226 ("?primitives of 'C'P'P types must be imported from C++"
3227 & " or abstract", Prim);
3229 elsif not Has_Constructors
3230 and then not Error_Reported
3232 Error_Msg_Name_1 := Chars (E);
3234 ("?'C'P'P constructor required for type %", Prim);
3235 Error_Reported := True;
3244 Inside_Freezing_Actions := Inside_Freezing_Actions - 1;
3246 -- If we have a type with predicates, build predicate function
3248 if Is_Type (E) and then Has_Predicates (E) then
3249 Build_Predicate_Function (E, N);
3252 -- If type has delayed aspects, this is where we do the preanalysis at
3253 -- the freeze point, as part of the consistent visibility check. Note
3254 -- that this must be done after calling Build_Predicate_Function or
3255 -- Build_Invariant_Procedure since these subprograms fix occurrences of
3256 -- the subtype name in the saved expression so that they will not cause
3257 -- trouble in the preanalysis.
3259 if Has_Delayed_Aspects (E) then
3264 -- Look for aspect specification entries for this entity
3266 Ritem := First_Rep_Item (E);
3267 while Present (Ritem) loop
3268 if Nkind (Ritem) = N_Aspect_Specification
3269 and then Entity (Ritem) = E
3270 and then Is_Delayed_Aspect (Ritem)
3272 Check_Aspect_At_Freeze_Point (Ritem);
3275 Next_Rep_Item (Ritem);
3279 end Analyze_Freeze_Entity;
3281 ------------------------------------------
3282 -- Analyze_Record_Representation_Clause --
3283 ------------------------------------------
3285 -- Note: we check as much as we can here, but we can't do any checks
3286 -- based on the position values (e.g. overlap checks) until freeze time
3287 -- because especially in Ada 2005 (machine scalar mode), the processing
3288 -- for non-standard bit order can substantially change the positions.
3289 -- See procedure Check_Record_Representation_Clause (called from Freeze)
3290 -- for the remainder of this processing.
3292 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
3293 Ident : constant Node_Id := Identifier (N);
3298 Hbit : Uint := Uint_0;
3302 Rectype : Entity_Id;
3304 CR_Pragma : Node_Id := Empty;
3305 -- Points to N_Pragma node if Complete_Representation pragma present
3308 if Ignore_Rep_Clauses then
3313 Rectype := Entity (Ident);
3315 if Rectype = Any_Type
3316 or else Rep_Item_Too_Early (Rectype, N)
3320 Rectype := Underlying_Type (Rectype);
3323 -- First some basic error checks
3325 if not Is_Record_Type (Rectype) then
3327 ("record type required, found}", Ident, First_Subtype (Rectype));
3330 elsif Scope (Rectype) /= Current_Scope then
3331 Error_Msg_N ("type must be declared in this scope", N);
3334 elsif not Is_First_Subtype (Rectype) then
3335 Error_Msg_N ("cannot give record rep clause for subtype", N);
3338 elsif Has_Record_Rep_Clause (Rectype) then
3339 Error_Msg_N ("duplicate record rep clause ignored", N);
3342 elsif Rep_Item_Too_Late (Rectype, N) then
3346 if Present (Mod_Clause (N)) then
3348 Loc : constant Source_Ptr := Sloc (N);
3349 M : constant Node_Id := Mod_Clause (N);
3350 P : constant List_Id := Pragmas_Before (M);
3354 pragma Warnings (Off, Mod_Val);
3357 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
3359 if Warn_On_Obsolescent_Feature then
3361 ("mod clause is an obsolescent feature (RM J.8)?", N);
3363 ("\use alignment attribute definition clause instead?", N);
3370 -- In ASIS_Mode mode, expansion is disabled, but we must convert
3371 -- the Mod clause into an alignment clause anyway, so that the
3372 -- back-end can compute and back-annotate properly the size and
3373 -- alignment of types that may include this record.
3375 -- This seems dubious, this destroys the source tree in a manner
3376 -- not detectable by ASIS ???
3378 if Operating_Mode = Check_Semantics
3382 Make_Attribute_Definition_Clause (Loc,
3383 Name => New_Reference_To (Base_Type (Rectype), Loc),
3384 Chars => Name_Alignment,
3385 Expression => Relocate_Node (Expression (M)));
3387 Set_From_At_Mod (AtM_Nod);
3388 Insert_After (N, AtM_Nod);
3389 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
3390 Set_Mod_Clause (N, Empty);
3393 -- Get the alignment value to perform error checking
3395 Mod_Val := Get_Alignment_Value (Expression (M));
3400 -- For untagged types, clear any existing component clauses for the
3401 -- type. If the type is derived, this is what allows us to override
3402 -- a rep clause for the parent. For type extensions, the representation
3403 -- of the inherited components is inherited, so we want to keep previous
3404 -- component clauses for completeness.
3406 if not Is_Tagged_Type (Rectype) then
3407 Comp := First_Component_Or_Discriminant (Rectype);
3408 while Present (Comp) loop
3409 Set_Component_Clause (Comp, Empty);
3410 Next_Component_Or_Discriminant (Comp);
3414 -- All done if no component clauses
3416 CC := First (Component_Clauses (N));
3422 -- A representation like this applies to the base type
3424 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
3425 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
3426 Set_Has_Specified_Layout (Base_Type (Rectype));
3428 -- Process the component clauses
3430 while Present (CC) loop
3434 if Nkind (CC) = N_Pragma then
3437 -- The only pragma of interest is Complete_Representation
3439 if Pragma_Name (CC) = Name_Complete_Representation then
3443 -- Processing for real component clause
3446 Posit := Static_Integer (Position (CC));
3447 Fbit := Static_Integer (First_Bit (CC));
3448 Lbit := Static_Integer (Last_Bit (CC));
3451 and then Fbit /= No_Uint
3452 and then Lbit /= No_Uint
3456 ("position cannot be negative", Position (CC));
3460 ("first bit cannot be negative", First_Bit (CC));
3462 -- The Last_Bit specified in a component clause must not be
3463 -- less than the First_Bit minus one (RM-13.5.1(10)).
3465 elsif Lbit < Fbit - 1 then
3467 ("last bit cannot be less than first bit minus one",
3470 -- Values look OK, so find the corresponding record component
3471 -- Even though the syntax allows an attribute reference for
3472 -- implementation-defined components, GNAT does not allow the
3473 -- tag to get an explicit position.
3475 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
3476 if Attribute_Name (Component_Name (CC)) = Name_Tag then
3477 Error_Msg_N ("position of tag cannot be specified", CC);
3479 Error_Msg_N ("illegal component name", CC);
3483 Comp := First_Entity (Rectype);
3484 while Present (Comp) loop
3485 exit when Chars (Comp) = Chars (Component_Name (CC));
3491 -- Maybe component of base type that is absent from
3492 -- statically constrained first subtype.
3494 Comp := First_Entity (Base_Type (Rectype));
3495 while Present (Comp) loop
3496 exit when Chars (Comp) = Chars (Component_Name (CC));
3503 ("component clause is for non-existent field", CC);
3505 -- Ada 2012 (AI05-0026): Any name that denotes a
3506 -- discriminant of an object of an unchecked union type
3507 -- shall not occur within a record_representation_clause.
3509 -- The general restriction of using record rep clauses on
3510 -- Unchecked_Union types has now been lifted. Since it is
3511 -- possible to introduce a record rep clause which mentions
3512 -- the discriminant of an Unchecked_Union in non-Ada 2012
3513 -- code, this check is applied to all versions of the
3516 elsif Ekind (Comp) = E_Discriminant
3517 and then Is_Unchecked_Union (Rectype)
3520 ("cannot reference discriminant of Unchecked_Union",
3521 Component_Name (CC));
3523 elsif Present (Component_Clause (Comp)) then
3525 -- Diagnose duplicate rep clause, or check consistency
3526 -- if this is an inherited component. In a double fault,
3527 -- there may be a duplicate inconsistent clause for an
3528 -- inherited component.
3530 if Scope (Original_Record_Component (Comp)) = Rectype
3531 or else Parent (Component_Clause (Comp)) = N
3533 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
3534 Error_Msg_N ("component clause previously given#", CC);
3538 Rep1 : constant Node_Id := Component_Clause (Comp);
3540 if Intval (Position (Rep1)) /=
3541 Intval (Position (CC))
3542 or else Intval (First_Bit (Rep1)) /=
3543 Intval (First_Bit (CC))
3544 or else Intval (Last_Bit (Rep1)) /=
3545 Intval (Last_Bit (CC))
3547 Error_Msg_N ("component clause inconsistent "
3548 & "with representation of ancestor", CC);
3549 elsif Warn_On_Redundant_Constructs then
3550 Error_Msg_N ("?redundant component clause "
3551 & "for inherited component!", CC);
3556 -- Normal case where this is the first component clause we
3557 -- have seen for this entity, so set it up properly.
3560 -- Make reference for field in record rep clause and set
3561 -- appropriate entity field in the field identifier.
3564 (Comp, Component_Name (CC), Set_Ref => False);
3565 Set_Entity (Component_Name (CC), Comp);
3567 -- Update Fbit and Lbit to the actual bit number
3569 Fbit := Fbit + UI_From_Int (SSU) * Posit;
3570 Lbit := Lbit + UI_From_Int (SSU) * Posit;
3572 if Has_Size_Clause (Rectype)
3573 and then Esize (Rectype) <= Lbit
3576 ("bit number out of range of specified size",
3579 Set_Component_Clause (Comp, CC);
3580 Set_Component_Bit_Offset (Comp, Fbit);
3581 Set_Esize (Comp, 1 + (Lbit - Fbit));
3582 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
3583 Set_Normalized_Position (Comp, Fbit / SSU);
3585 if Warn_On_Overridden_Size
3586 and then Has_Size_Clause (Etype (Comp))
3587 and then RM_Size (Etype (Comp)) /= Esize (Comp)
3590 ("?component size overrides size clause for&",
3591 Component_Name (CC), Etype (Comp));
3594 -- This information is also set in the corresponding
3595 -- component of the base type, found by accessing the
3596 -- Original_Record_Component link if it is present.
3598 Ocomp := Original_Record_Component (Comp);
3605 (Component_Name (CC),
3611 (Comp, First_Node (CC), "component clause", Biased);
3613 if Present (Ocomp) then
3614 Set_Component_Clause (Ocomp, CC);
3615 Set_Component_Bit_Offset (Ocomp, Fbit);
3616 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
3617 Set_Normalized_Position (Ocomp, Fbit / SSU);
3618 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
3620 Set_Normalized_Position_Max
3621 (Ocomp, Normalized_Position (Ocomp));
3623 -- Note: we don't use Set_Biased here, because we
3624 -- already gave a warning above if needed, and we
3625 -- would get a duplicate for the same name here.
3627 Set_Has_Biased_Representation
3628 (Ocomp, Has_Biased_Representation (Comp));
3631 if Esize (Comp) < 0 then
3632 Error_Msg_N ("component size is negative", CC);
3643 -- Check missing components if Complete_Representation pragma appeared
3645 if Present (CR_Pragma) then
3646 Comp := First_Component_Or_Discriminant (Rectype);
3647 while Present (Comp) loop
3648 if No (Component_Clause (Comp)) then
3650 ("missing component clause for &", CR_Pragma, Comp);
3653 Next_Component_Or_Discriminant (Comp);
3656 -- If no Complete_Representation pragma, warn if missing components
3658 elsif Warn_On_Unrepped_Components then
3660 Num_Repped_Components : Nat := 0;
3661 Num_Unrepped_Components : Nat := 0;
3664 -- First count number of repped and unrepped components
3666 Comp := First_Component_Or_Discriminant (Rectype);
3667 while Present (Comp) loop
3668 if Present (Component_Clause (Comp)) then
3669 Num_Repped_Components := Num_Repped_Components + 1;
3671 Num_Unrepped_Components := Num_Unrepped_Components + 1;
3674 Next_Component_Or_Discriminant (Comp);
3677 -- We are only interested in the case where there is at least one
3678 -- unrepped component, and at least half the components have rep
3679 -- clauses. We figure that if less than half have them, then the
3680 -- partial rep clause is really intentional. If the component
3681 -- type has no underlying type set at this point (as for a generic
3682 -- formal type), we don't know enough to give a warning on the
3685 if Num_Unrepped_Components > 0
3686 and then Num_Unrepped_Components < Num_Repped_Components
3688 Comp := First_Component_Or_Discriminant (Rectype);
3689 while Present (Comp) loop
3690 if No (Component_Clause (Comp))
3691 and then Comes_From_Source (Comp)
3692 and then Present (Underlying_Type (Etype (Comp)))
3693 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
3694 or else Size_Known_At_Compile_Time
3695 (Underlying_Type (Etype (Comp))))
3696 and then not Has_Warnings_Off (Rectype)
3698 Error_Msg_Sloc := Sloc (Comp);
3700 ("?no component clause given for & declared #",
3704 Next_Component_Or_Discriminant (Comp);
3709 end Analyze_Record_Representation_Clause;
3711 -------------------------------
3712 -- Build_Invariant_Procedure --
3713 -------------------------------
3715 -- The procedure that is constructed here has the form
3717 -- procedure typInvariant (Ixxx : typ) is
3719 -- pragma Check (Invariant, exp, "failed invariant from xxx");
3720 -- pragma Check (Invariant, exp, "failed invariant from xxx");
3722 -- pragma Check (Invariant, exp, "failed inherited invariant from xxx");
3724 -- end typInvariant;
3726 procedure Build_Invariant_Procedure (Typ : Entity_Id; N : Node_Id) is
3727 Loc : constant Source_Ptr := Sloc (Typ);
3734 Visible_Decls : constant List_Id := Visible_Declarations (N);
3735 Private_Decls : constant List_Id := Private_Declarations (N);
3737 procedure Add_Invariants (T : Entity_Id; Inherit : Boolean);
3738 -- Appends statements to Stmts for any invariants in the rep item chain
3739 -- of the given type. If Inherit is False, then we only process entries
3740 -- on the chain for the type Typ. If Inherit is True, then we ignore any
3741 -- Invariant aspects, but we process all Invariant'Class aspects, adding
3742 -- "inherited" to the exception message and generating an informational
3743 -- message about the inheritance of an invariant.
3745 Object_Name : constant Name_Id := New_Internal_Name ('I');
3746 -- Name for argument of invariant procedure
3748 Object_Entity : constant Node_Id :=
3749 Make_Defining_Identifier (Loc, Object_Name);
3750 -- The procedure declaration entity for the argument
3752 --------------------
3753 -- Add_Invariants --
3754 --------------------
3756 procedure Add_Invariants (T : Entity_Id; Inherit : Boolean) is
3766 procedure Replace_Type_Reference (N : Node_Id);
3767 -- Replace a single occurrence N of the subtype name with a reference
3768 -- to the formal of the predicate function. N can be an identifier
3769 -- referencing the subtype, or a selected component, representing an
3770 -- appropriately qualified occurrence of the subtype name.
3772 procedure Replace_Type_References is
3773 new Replace_Type_References_Generic (Replace_Type_Reference);
3774 -- Traverse an expression replacing all occurrences of the subtype
3775 -- name with appropriate references to the object that is the formal
3776 -- parameter of the predicate function. Note that we must ensure
3777 -- that the type and entity information is properly set in the
3778 -- replacement node, since we will do a Preanalyze call of this
3779 -- expression without proper visibility of the procedure argument.
3781 ----------------------------
3782 -- Replace_Type_Reference --
3783 ----------------------------
3785 procedure Replace_Type_Reference (N : Node_Id) is
3787 -- Invariant'Class, replace with T'Class (obj)
3789 if Class_Present (Ritem) then
3791 Make_Type_Conversion (Loc,
3793 Make_Attribute_Reference (Loc,
3794 Prefix => New_Occurrence_Of (T, Loc),
3795 Attribute_Name => Name_Class),
3796 Expression => Make_Identifier (Loc, Object_Name)));
3798 Set_Entity (Expression (N), Object_Entity);
3799 Set_Etype (Expression (N), Typ);
3801 -- Invariant, replace with obj
3804 Rewrite (N, Make_Identifier (Loc, Object_Name));
3805 Set_Entity (N, Object_Entity);
3808 end Replace_Type_Reference;
3810 -- Start of processing for Add_Invariants
3813 Ritem := First_Rep_Item (T);
3814 while Present (Ritem) loop
3815 if Nkind (Ritem) = N_Pragma
3816 and then Pragma_Name (Ritem) = Name_Invariant
3818 Arg1 := First (Pragma_Argument_Associations (Ritem));
3819 Arg2 := Next (Arg1);
3820 Arg3 := Next (Arg2);
3822 Arg1 := Get_Pragma_Arg (Arg1);
3823 Arg2 := Get_Pragma_Arg (Arg2);
3825 -- For Inherit case, ignore Invariant, process only Class case
3828 if not Class_Present (Ritem) then
3832 -- For Inherit false, process only item for right type
3835 if Entity (Arg1) /= Typ then
3841 Stmts := Empty_List;
3844 Exp := New_Copy_Tree (Arg2);
3847 -- We need to replace any occurrences of the name of the type
3848 -- with references to the object, converted to type'Class in
3849 -- the case of Invariant'Class aspects.
3851 Replace_Type_References (Exp, Chars (T));
3853 -- If this invariant comes from an aspect, find the aspect
3854 -- specification, and replace the saved expression because
3855 -- we need the subtype references replaced for the calls to
3856 -- Preanalyze_Spec_Expressin in Check_Aspect_At_Freeze_Point
3857 -- and Check_Aspect_At_End_Of_Declarations.
3859 if From_Aspect_Specification (Ritem) then
3864 -- Loop to find corresponding aspect, note that this
3865 -- must be present given the pragma is marked delayed.
3867 Aitem := Next_Rep_Item (Ritem);
3868 while Present (Aitem) loop
3869 if Nkind (Aitem) = N_Aspect_Specification
3870 and then Aspect_Rep_Item (Aitem) = Ritem
3873 (Identifier (Aitem), New_Copy_Tree (Exp));
3877 Aitem := Next_Rep_Item (Aitem);
3882 -- Now we need to preanalyze the expression to properly capture
3883 -- the visibility in the visible part. The expression will not
3884 -- be analyzed for real until the body is analyzed, but that is
3885 -- at the end of the private part and has the wrong visibility.
3887 Set_Parent (Exp, N);
3888 Preanalyze_Spec_Expression (Exp, Standard_Boolean);
3890 -- Build first two arguments for Check pragma
3893 Make_Pragma_Argument_Association (Loc,
3894 Expression => Make_Identifier (Loc, Name_Invariant)),
3895 Make_Pragma_Argument_Association (Loc, Expression => Exp));
3897 -- Add message if present in Invariant pragma
3899 if Present (Arg3) then
3900 Str := Strval (Get_Pragma_Arg (Arg3));
3902 -- If inherited case, and message starts "failed invariant",
3903 -- change it to be "failed inherited invariant".
3906 String_To_Name_Buffer (Str);
3908 if Name_Buffer (1 .. 16) = "failed invariant" then
3909 Insert_Str_In_Name_Buffer ("inherited ", 8);
3910 Str := String_From_Name_Buffer;
3915 Make_Pragma_Argument_Association (Loc,
3916 Expression => Make_String_Literal (Loc, Str)));
3919 -- Add Check pragma to list of statements
3923 Pragma_Identifier =>
3924 Make_Identifier (Loc, Name_Check),
3925 Pragma_Argument_Associations => Assoc));
3927 -- If Inherited case and option enabled, output info msg. Note
3928 -- that we know this is a case of Invariant'Class.
3930 if Inherit and Opt.List_Inherited_Aspects then
3931 Error_Msg_Sloc := Sloc (Ritem);
3933 ("?info: & inherits `Invariant''Class` aspect from #",
3939 Next_Rep_Item (Ritem);
3943 -- Start of processing for Build_Invariant_Procedure
3949 Set_Etype (Object_Entity, Typ);
3951 -- Add invariants for the current type
3953 Add_Invariants (Typ, Inherit => False);
3955 -- Add invariants for parent types
3958 Current_Typ : Entity_Id;
3959 Parent_Typ : Entity_Id;
3964 Parent_Typ := Etype (Current_Typ);
3966 if Is_Private_Type (Parent_Typ)
3967 and then Present (Full_View (Base_Type (Parent_Typ)))
3969 Parent_Typ := Full_View (Base_Type (Parent_Typ));
3972 exit when Parent_Typ = Current_Typ;
3974 Current_Typ := Parent_Typ;
3975 Add_Invariants (Current_Typ, Inherit => True);
3979 -- Build the procedure if we generated at least one Check pragma
3981 if Stmts /= No_List then
3983 -- Build procedure declaration
3986 Make_Defining_Identifier (Loc,
3987 Chars => New_External_Name (Chars (Typ), "Invariant"));
3988 Set_Has_Invariants (SId);
3989 Set_Invariant_Procedure (Typ, SId);
3992 Make_Procedure_Specification (Loc,
3993 Defining_Unit_Name => SId,
3994 Parameter_Specifications => New_List (
3995 Make_Parameter_Specification (Loc,
3996 Defining_Identifier => Object_Entity,
3997 Parameter_Type => New_Occurrence_Of (Typ, Loc))));
3999 PDecl := Make_Subprogram_Declaration (Loc, Specification => Spec);
4001 -- Build procedure body
4004 Make_Defining_Identifier (Loc,
4005 Chars => New_External_Name (Chars (Typ), "Invariant"));
4008 Make_Procedure_Specification (Loc,
4009 Defining_Unit_Name => SId,
4010 Parameter_Specifications => New_List (
4011 Make_Parameter_Specification (Loc,
4012 Defining_Identifier =>
4013 Make_Defining_Identifier (Loc, Object_Name),
4014 Parameter_Type => New_Occurrence_Of (Typ, Loc))));
4017 Make_Subprogram_Body (Loc,
4018 Specification => Spec,
4019 Declarations => Empty_List,
4020 Handled_Statement_Sequence =>
4021 Make_Handled_Sequence_Of_Statements (Loc,
4022 Statements => Stmts));
4024 -- Insert procedure declaration and spec at the appropriate points.
4025 -- Skip this if there are no private declarations (that's an error
4026 -- that will be diagnosed elsewhere, and there is no point in having
4027 -- an invariant procedure set if the full declaration is missing).
4029 if Present (Private_Decls) then
4031 -- The spec goes at the end of visible declarations, but they have
4032 -- already been analyzed, so we need to explicitly do the analyze.
4034 Append_To (Visible_Decls, PDecl);
4037 -- The body goes at the end of the private declarations, which we
4038 -- have not analyzed yet, so we do not need to perform an explicit
4039 -- analyze call. We skip this if there are no private declarations
4040 -- (this is an error that will be caught elsewhere);
4042 Append_To (Private_Decls, PBody);
4045 end Build_Invariant_Procedure;
4047 ------------------------------
4048 -- Build_Predicate_Function --
4049 ------------------------------
4051 -- The procedure that is constructed here has the form
4053 -- function typPredicate (Ixxx : typ) return Boolean is
4056 -- exp1 and then exp2 and then ...
4057 -- and then typ1Predicate (typ1 (Ixxx))
4058 -- and then typ2Predicate (typ2 (Ixxx))
4060 -- end typPredicate;
4062 -- Here exp1, and exp2 are expressions from Predicate pragmas. Note that
4063 -- this is the point at which these expressions get analyzed, providing the
4064 -- required delay, and typ1, typ2, are entities from which predicates are
4065 -- inherited. Note that we do NOT generate Check pragmas, that's because we
4066 -- use this function even if checks are off, e.g. for membership tests.
4068 procedure Build_Predicate_Function (Typ : Entity_Id; N : Node_Id) is
4069 Loc : constant Source_Ptr := Sloc (Typ);
4076 -- This is the expression for the return statement in the function. It
4077 -- is build by connecting the component predicates with AND THEN.
4079 procedure Add_Call (T : Entity_Id);
4080 -- Includes a call to the predicate function for type T in Expr if T
4081 -- has predicates and Predicate_Function (T) is non-empty.
4083 procedure Add_Predicates;
4084 -- Appends expressions for any Predicate pragmas in the rep item chain
4085 -- Typ to Expr. Note that we look only at items for this exact entity.
4086 -- Inheritance of predicates for the parent type is done by calling the
4087 -- Predicate_Function of the parent type, using Add_Call above.
4089 Object_Name : constant Name_Id := New_Internal_Name ('I');
4090 -- Name for argument of Predicate procedure
4092 Object_Entity : constant Entity_Id :=
4093 Make_Defining_Identifier (Loc, Object_Name);
4094 -- The entity for the spec entity for the argument
4096 Dynamic_Predicate_Present : Boolean := False;
4097 -- Set True if a dynamic predicate is present, results in the entire
4098 -- predicate being considered dynamic even if it looks static
4100 Static_Predicate_Present : Node_Id := Empty;
4101 -- Set to N_Pragma node for a static predicate if one is encountered.
4107 procedure Add_Call (T : Entity_Id) is
4111 if Present (T) and then Present (Predicate_Function (T)) then
4112 Set_Has_Predicates (Typ);
4114 -- Build the call to the predicate function of T
4118 (T, Convert_To (T, Make_Identifier (Loc, Object_Name)));
4120 -- Add call to evolving expression, using AND THEN if needed
4127 Left_Opnd => Relocate_Node (Expr),
4131 -- Output info message on inheritance if required. Note we do not
4132 -- give this information for generic actual types, since it is
4133 -- unwelcome noise in that case in instantiations. We also
4134 -- generally suppress the message in instantiations, and also
4135 -- if it involves internal names.
4137 if Opt.List_Inherited_Aspects
4138 and then not Is_Generic_Actual_Type (Typ)
4139 and then Instantiation_Depth (Sloc (Typ)) = 0
4140 and then not Is_Internal_Name (Chars (T))
4141 and then not Is_Internal_Name (Chars (Typ))
4143 Error_Msg_Sloc := Sloc (Predicate_Function (T));
4144 Error_Msg_Node_2 := T;
4145 Error_Msg_N ("?info: & inherits predicate from & #", Typ);
4150 --------------------
4151 -- Add_Predicates --
4152 --------------------
4154 procedure Add_Predicates is
4159 procedure Replace_Type_Reference (N : Node_Id);
4160 -- Replace a single occurrence N of the subtype name with a reference
4161 -- to the formal of the predicate function. N can be an identifier
4162 -- referencing the subtype, or a selected component, representing an
4163 -- appropriately qualified occurrence of the subtype name.
4165 procedure Replace_Type_References is
4166 new Replace_Type_References_Generic (Replace_Type_Reference);
4167 -- Traverse an expression changing every occurrence of an identifier
4168 -- whose name matches the name of the subtype with a reference to
4169 -- the formal parameter of the predicate function.
4171 ----------------------------
4172 -- Replace_Type_Reference --
4173 ----------------------------
4175 procedure Replace_Type_Reference (N : Node_Id) is
4177 Rewrite (N, Make_Identifier (Loc, Object_Name));
4178 Set_Entity (N, Object_Entity);
4180 end Replace_Type_Reference;
4182 -- Start of processing for Add_Predicates
4185 Ritem := First_Rep_Item (Typ);
4186 while Present (Ritem) loop
4187 if Nkind (Ritem) = N_Pragma
4188 and then Pragma_Name (Ritem) = Name_Predicate
4190 if From_Dynamic_Predicate (Ritem) then
4191 Dynamic_Predicate_Present := True;
4192 elsif From_Static_Predicate (Ritem) then
4193 Static_Predicate_Present := Ritem;
4196 -- Acquire arguments
4198 Arg1 := First (Pragma_Argument_Associations (Ritem));
4199 Arg2 := Next (Arg1);
4201 Arg1 := Get_Pragma_Arg (Arg1);
4202 Arg2 := Get_Pragma_Arg (Arg2);
4204 -- See if this predicate pragma is for the current type
4206 if Entity (Arg1) = Typ then
4208 -- We have a match, this entry is for our subtype
4210 -- We need to replace any occurrences of the name of the
4211 -- type with references to the object.
4213 Replace_Type_References (Arg2, Chars (Typ));
4215 -- If this predicate comes from an aspect, find the aspect
4216 -- specification, and replace the saved expression because
4217 -- we need the subtype references replaced for the calls to
4218 -- Preanalyze_Spec_Expressin in Check_Aspect_At_Freeze_Point
4219 -- and Check_Aspect_At_End_Of_Declarations.
4221 if From_Aspect_Specification (Ritem) then
4226 -- Loop to find corresponding aspect, note that this
4227 -- must be present given the pragma is marked delayed.
4229 Aitem := Next_Rep_Item (Ritem);
4231 if Nkind (Aitem) = N_Aspect_Specification
4232 and then Aspect_Rep_Item (Aitem) = Ritem
4235 (Identifier (Aitem), New_Copy_Tree (Arg2));
4239 Aitem := Next_Rep_Item (Aitem);
4244 -- Now we can add the expression
4247 Expr := Relocate_Node (Arg2);
4249 -- There already was a predicate, so add to it
4254 Left_Opnd => Relocate_Node (Expr),
4255 Right_Opnd => Relocate_Node (Arg2));
4260 Next_Rep_Item (Ritem);
4264 -- Start of processing for Build_Predicate_Function
4267 -- Initialize for construction of statement list
4271 -- Return if already built or if type does not have predicates
4273 if not Has_Predicates (Typ)
4274 or else Present (Predicate_Function (Typ))
4279 -- Add Predicates for the current type
4283 -- Add predicates for ancestor if present
4286 Atyp : constant Entity_Id := Nearest_Ancestor (Typ);
4288 if Present (Atyp) then
4293 -- If we have predicates, build the function
4295 if Present (Expr) then
4297 -- Build function declaration
4299 pragma Assert (Has_Predicates (Typ));
4301 Make_Defining_Identifier (Loc,
4302 Chars => New_External_Name (Chars (Typ), "Predicate"));
4303 Set_Has_Predicates (SId);
4304 Set_Predicate_Function (Typ, SId);
4307 Make_Function_Specification (Loc,
4308 Defining_Unit_Name => SId,
4309 Parameter_Specifications => New_List (
4310 Make_Parameter_Specification (Loc,
4311 Defining_Identifier => Object_Entity,
4312 Parameter_Type => New_Occurrence_Of (Typ, Loc))),
4313 Result_Definition =>
4314 New_Occurrence_Of (Standard_Boolean, Loc));
4316 FDecl := Make_Subprogram_Declaration (Loc, Specification => Spec);
4318 -- Build function body
4321 Make_Defining_Identifier (Loc,
4322 Chars => New_External_Name (Chars (Typ), "Predicate"));
4325 Make_Function_Specification (Loc,
4326 Defining_Unit_Name => SId,
4327 Parameter_Specifications => New_List (
4328 Make_Parameter_Specification (Loc,
4329 Defining_Identifier =>
4330 Make_Defining_Identifier (Loc, Object_Name),
4332 New_Occurrence_Of (Typ, Loc))),
4333 Result_Definition =>
4334 New_Occurrence_Of (Standard_Boolean, Loc));
4337 Make_Subprogram_Body (Loc,
4338 Specification => Spec,
4339 Declarations => Empty_List,
4340 Handled_Statement_Sequence =>
4341 Make_Handled_Sequence_Of_Statements (Loc,
4342 Statements => New_List (
4343 Make_Simple_Return_Statement (Loc,
4344 Expression => Expr))));
4346 -- Insert declaration before freeze node and body after
4348 Insert_Before_And_Analyze (N, FDecl);
4349 Insert_After_And_Analyze (N, FBody);
4351 -- Deal with static predicate case
4353 if Ekind_In (Typ, E_Enumeration_Subtype,
4354 E_Modular_Integer_Subtype,
4355 E_Signed_Integer_Subtype)
4356 and then Is_Static_Subtype (Typ)
4357 and then not Dynamic_Predicate_Present
4359 Build_Static_Predicate (Typ, Expr, Object_Name);
4361 if Present (Static_Predicate_Present)
4362 and No (Static_Predicate (Typ))
4365 ("expression does not have required form for "
4366 & "static predicate",
4367 Next (First (Pragma_Argument_Associations
4368 (Static_Predicate_Present))));
4372 end Build_Predicate_Function;
4374 ----------------------------
4375 -- Build_Static_Predicate --
4376 ----------------------------
4378 procedure Build_Static_Predicate
4383 Loc : constant Source_Ptr := Sloc (Expr);
4385 Non_Static : exception;
4386 -- Raised if something non-static is found
4388 Btyp : constant Entity_Id := Base_Type (Typ);
4390 BLo : constant Uint := Expr_Value (Type_Low_Bound (Btyp));
4391 BHi : constant Uint := Expr_Value (Type_High_Bound (Btyp));
4392 -- Low bound and high bound value of base type of Typ
4394 TLo : constant Uint := Expr_Value (Type_Low_Bound (Typ));
4395 THi : constant Uint := Expr_Value (Type_High_Bound (Typ));
4396 -- Low bound and high bound values of static subtype Typ
4401 -- One entry in a Rlist value, a single REnt (range entry) value
4402 -- denotes one range from Lo to Hi. To represent a single value
4403 -- range Lo = Hi = value.
4405 type RList is array (Nat range <>) of REnt;
4406 -- A list of ranges. The ranges are sorted in increasing order,
4407 -- and are disjoint (there is a gap of at least one value between
4408 -- each range in the table). A value is in the set of ranges in
4409 -- Rlist if it lies within one of these ranges
4411 False_Range : constant RList :=
4412 RList'(1 .. 0 => REnt'(No_Uint, No_Uint));
4413 -- An empty set of ranges represents a range list that can never be
4414 -- satisfied, since there are no ranges in which the value could lie,
4415 -- so it does not lie in any of them. False_Range is a canonical value
4416 -- for this empty set, but general processing should test for an Rlist
4417 -- with length zero (see Is_False predicate), since other null ranges
4418 -- may appear which must be treated as False.
4420 True_Range : constant RList := RList'(1 => REnt'(BLo, BHi));
4421 -- Range representing True, value must be in the base range
4423 function "and" (Left, Right : RList) return RList;
4424 -- And's together two range lists, returning a range list. This is
4425 -- a set intersection operation.
4427 function "or" (Left, Right : RList) return RList;
4428 -- Or's together two range lists, returning a range list. This is a
4429 -- set union operation.
4431 function "not" (Right : RList) return RList;
4432 -- Returns complement of a given range list, i.e. a range list
4433 -- representing all the values in TLo .. THi that are not in the
4434 -- input operand Right.
4436 function Build_Val (V : Uint) return Node_Id;
4437 -- Return an analyzed N_Identifier node referencing this value, suitable
4438 -- for use as an entry in the Static_Predicate list. This node is typed
4439 -- with the base type.
4441 function Build_Range (Lo, Hi : Uint) return Node_Id;
4442 -- Return an analyzed N_Range node referencing this range, suitable
4443 -- for use as an entry in the Static_Predicate list. This node is typed
4444 -- with the base type.
4446 function Get_RList (Exp : Node_Id) return RList;
4447 -- This is a recursive routine that converts the given expression into
4448 -- a list of ranges, suitable for use in building the static predicate.
4450 function Is_False (R : RList) return Boolean;
4451 pragma Inline (Is_False);
4452 -- Returns True if the given range list is empty, and thus represents
4453 -- a False list of ranges that can never be satisfied.
4455 function Is_True (R : RList) return Boolean;
4456 -- Returns True if R trivially represents the True predicate by having
4457 -- a single range from BLo to BHi.
4459 function Is_Type_Ref (N : Node_Id) return Boolean;
4460 pragma Inline (Is_Type_Ref);
4461 -- Returns if True if N is a reference to the type for the predicate in
4462 -- the expression (i.e. if it is an identifier whose Chars field matches
4463 -- the Nam given in the call).
4465 function Lo_Val (N : Node_Id) return Uint;
4466 -- Given static expression or static range from a Static_Predicate list,
4467 -- gets expression value or low bound of range.
4469 function Hi_Val (N : Node_Id) return Uint;
4470 -- Given static expression or static range from a Static_Predicate list,
4471 -- gets expression value of high bound of range.
4473 function Membership_Entry (N : Node_Id) return RList;
4474 -- Given a single membership entry (range, value, or subtype), returns
4475 -- the corresponding range list. Raises Static_Error if not static.
4477 function Membership_Entries (N : Node_Id) return RList;
4478 -- Given an element on an alternatives list of a membership operation,
4479 -- returns the range list corresponding to this entry and all following
4480 -- entries (i.e. returns the "or" of this list of values).
4482 function Stat_Pred (Typ : Entity_Id) return RList;
4483 -- Given a type, if it has a static predicate, then return the predicate
4484 -- as a range list, otherwise raise Non_Static.
4490 function "and" (Left, Right : RList) return RList is
4492 -- First range of result
4494 SLeft : Nat := Left'First;
4495 -- Start of rest of left entries
4497 SRight : Nat := Right'First;
4498 -- Start of rest of right entries
4501 -- If either range is True, return the other
4503 if Is_True (Left) then
4505 elsif Is_True (Right) then
4509 -- If either range is False, return False
4511 if Is_False (Left) or else Is_False (Right) then
4515 -- Loop to remove entries at start that are disjoint, and thus
4516 -- just get discarded from the result entirely.
4519 -- If no operands left in either operand, result is false
4521 if SLeft > Left'Last or else SRight > Right'Last then
4524 -- Discard first left operand entry if disjoint with right
4526 elsif Left (SLeft).Hi < Right (SRight).Lo then
4529 -- Discard first right operand entry if disjoint with left
4531 elsif Right (SRight).Hi < Left (SLeft).Lo then
4532 SRight := SRight + 1;
4534 -- Otherwise we have an overlapping entry
4541 -- Now we have two non-null operands, and first entries overlap.
4542 -- The first entry in the result will be the overlapping part of
4543 -- these two entries.
4545 FEnt := REnt'(Lo => UI_Max (Left (SLeft).Lo, Right (SRight).Lo),
4546 Hi => UI_Min (Left (SLeft).Hi, Right (SRight).Hi));
4548 -- Now we can remove the entry that ended at a lower value, since
4549 -- its contribution is entirely contained in Fent.
4551 if Left (SLeft).Hi <= Right (SRight).Hi then
4554 SRight := SRight + 1;
4557 -- Compute result by concatenating this first entry with the "and"
4558 -- of the remaining parts of the left and right operands. Note that
4559 -- if either of these is empty, "and" will yield empty, so that we
4560 -- will end up with just Fent, which is what we want in that case.
4563 FEnt & (Left (SLeft .. Left'Last) and Right (SRight .. Right'Last));
4570 function "not" (Right : RList) return RList is
4572 -- Return True if False range
4574 if Is_False (Right) then
4578 -- Return False if True range
4580 if Is_True (Right) then
4584 -- Here if not trivial case
4587 Result : RList (1 .. Right'Length + 1);
4588 -- May need one more entry for gap at beginning and end
4591 -- Number of entries stored in Result
4596 if Right (Right'First).Lo > TLo then
4598 Result (Count) := REnt'(TLo, Right (Right'First).Lo - 1);
4601 -- Gaps between ranges
4603 for J in Right'First .. Right'Last - 1 loop
4606 REnt'(Right (J).Hi + 1, Right (J + 1).Lo - 1);
4611 if Right (Right'Last).Hi < THi then
4613 Result (Count) := REnt'(Right (Right'Last).Hi + 1, THi);
4616 return Result (1 .. Count);
4624 function "or" (Left, Right : RList) return RList is
4626 -- First range of result
4628 SLeft : Nat := Left'First;
4629 -- Start of rest of left entries
4631 SRight : Nat := Right'First;
4632 -- Start of rest of right entries
4635 -- If either range is True, return True
4637 if Is_True (Left) or else Is_True (Right) then
4641 -- If either range is False (empty), return the other
4643 if Is_False (Left) then
4645 elsif Is_False (Right) then
4649 -- Initialize result first entry from left or right operand
4650 -- depending on which starts with the lower range.
4652 if Left (SLeft).Lo < Right (SRight).Lo then
4653 FEnt := Left (SLeft);
4656 FEnt := Right (SRight);
4657 SRight := SRight + 1;
4660 -- This loop eats ranges from left and right operands that
4661 -- are contiguous with the first range we are gathering.
4664 -- Eat first entry in left operand if contiguous or
4665 -- overlapped by gathered first operand of result.
4667 if SLeft <= Left'Last
4668 and then Left (SLeft).Lo <= FEnt.Hi + 1
4670 FEnt.Hi := UI_Max (FEnt.Hi, Left (SLeft).Hi);
4673 -- Eat first entry in right operand if contiguous or
4674 -- overlapped by gathered right operand of result.
4676 elsif SRight <= Right'Last
4677 and then Right (SRight).Lo <= FEnt.Hi + 1
4679 FEnt.Hi := UI_Max (FEnt.Hi, Right (SRight).Hi);
4680 SRight := SRight + 1;
4682 -- All done if no more entries to eat!
4689 -- Obtain result as the first entry we just computed, concatenated
4690 -- to the "or" of the remaining results (if one operand is empty,
4691 -- this will just concatenate with the other
4694 FEnt & (Left (SLeft .. Left'Last) or Right (SRight .. Right'Last));
4701 function Build_Range (Lo, Hi : Uint) return Node_Id is
4705 return Build_Val (Hi);
4709 Low_Bound => Build_Val (Lo),
4710 High_Bound => Build_Val (Hi));
4711 Set_Etype (Result, Btyp);
4712 Set_Analyzed (Result);
4721 function Build_Val (V : Uint) return Node_Id is
4725 if Is_Enumeration_Type (Typ) then
4726 Result := Get_Enum_Lit_From_Pos (Typ, V, Loc);
4728 Result := Make_Integer_Literal (Loc, V);
4731 Set_Etype (Result, Btyp);
4732 Set_Is_Static_Expression (Result);
4733 Set_Analyzed (Result);
4741 function Get_RList (Exp : Node_Id) return RList is
4746 -- Static expression can only be true or false
4748 if Is_OK_Static_Expression (Exp) then
4752 if Expr_Value (Exp) = 0 then
4759 -- Otherwise test node type
4767 when N_Op_And | N_And_Then =>
4768 return Get_RList (Left_Opnd (Exp))
4770 Get_RList (Right_Opnd (Exp));
4774 when N_Op_Or | N_Or_Else =>
4775 return Get_RList (Left_Opnd (Exp))
4777 Get_RList (Right_Opnd (Exp));
4782 return not Get_RList (Right_Opnd (Exp));
4784 -- Comparisons of type with static value
4786 when N_Op_Compare =>
4787 -- Type is left operand
4789 if Is_Type_Ref (Left_Opnd (Exp))
4790 and then Is_OK_Static_Expression (Right_Opnd (Exp))
4792 Val := Expr_Value (Right_Opnd (Exp));
4794 -- Typ is right operand
4796 elsif Is_Type_Ref (Right_Opnd (Exp))
4797 and then Is_OK_Static_Expression (Left_Opnd (Exp))
4799 Val := Expr_Value (Left_Opnd (Exp));
4801 -- Invert sense of comparison
4804 when N_Op_Gt => Op := N_Op_Lt;
4805 when N_Op_Lt => Op := N_Op_Gt;
4806 when N_Op_Ge => Op := N_Op_Le;
4807 when N_Op_Le => Op := N_Op_Ge;
4808 when others => null;
4811 -- Other cases are non-static
4817 -- Construct range according to comparison operation
4821 return RList'(1 => REnt'(Val, Val));
4824 return RList'(1 => REnt'(Val, BHi));
4827 return RList'(1 => REnt'(Val + 1, BHi));
4830 return RList'(1 => REnt'(BLo, Val));
4833 return RList'(1 => REnt'(BLo, Val - 1));
4836 return RList'(REnt'(BLo, Val - 1),
4837 REnt'(Val + 1, BHi));
4840 raise Program_Error;
4846 if not Is_Type_Ref (Left_Opnd (Exp)) then
4850 if Present (Right_Opnd (Exp)) then
4851 return Membership_Entry (Right_Opnd (Exp));
4853 return Membership_Entries (First (Alternatives (Exp)));
4856 -- Negative membership (NOT IN)
4859 if not Is_Type_Ref (Left_Opnd (Exp)) then
4863 if Present (Right_Opnd (Exp)) then
4864 return not Membership_Entry (Right_Opnd (Exp));
4866 return not Membership_Entries (First (Alternatives (Exp)));
4869 -- Function call, may be call to static predicate
4871 when N_Function_Call =>
4872 if Is_Entity_Name (Name (Exp)) then
4874 Ent : constant Entity_Id := Entity (Name (Exp));
4876 if Has_Predicates (Ent) then
4877 return Stat_Pred (Etype (First_Formal (Ent)));
4882 -- Other function call cases are non-static
4886 -- Qualified expression, dig out the expression
4888 when N_Qualified_Expression =>
4889 return Get_RList (Expression (Exp));
4894 return (Get_RList (Left_Opnd (Exp))
4895 and not Get_RList (Right_Opnd (Exp)))
4896 or (Get_RList (Right_Opnd (Exp))
4897 and not Get_RList (Left_Opnd (Exp)));
4899 -- Any other node type is non-static
4910 function Hi_Val (N : Node_Id) return Uint is
4912 if Is_Static_Expression (N) then
4913 return Expr_Value (N);
4915 pragma Assert (Nkind (N) = N_Range);
4916 return Expr_Value (High_Bound (N));
4924 function Is_False (R : RList) return Boolean is
4926 return R'Length = 0;
4933 function Is_True (R : RList) return Boolean is
4936 and then R (R'First).Lo = BLo
4937 and then R (R'First).Hi = BHi;
4944 function Is_Type_Ref (N : Node_Id) return Boolean is
4946 return Nkind (N) = N_Identifier and then Chars (N) = Nam;
4953 function Lo_Val (N : Node_Id) return Uint is
4955 if Is_Static_Expression (N) then
4956 return Expr_Value (N);
4958 pragma Assert (Nkind (N) = N_Range);
4959 return Expr_Value (Low_Bound (N));
4963 ------------------------
4964 -- Membership_Entries --
4965 ------------------------
4967 function Membership_Entries (N : Node_Id) return RList is
4969 if No (Next (N)) then
4970 return Membership_Entry (N);
4972 return Membership_Entry (N) or Membership_Entries (Next (N));
4974 end Membership_Entries;
4976 ----------------------
4977 -- Membership_Entry --
4978 ----------------------
4980 function Membership_Entry (N : Node_Id) return RList is
4988 if Nkind (N) = N_Range then
4989 if not Is_Static_Expression (Low_Bound (N))
4991 not Is_Static_Expression (High_Bound (N))
4995 SLo := Expr_Value (Low_Bound (N));
4996 SHi := Expr_Value (High_Bound (N));
4997 return RList'(1 => REnt'(SLo, SHi));
5000 -- Static expression case
5002 elsif Is_Static_Expression (N) then
5003 Val := Expr_Value (N);
5004 return RList'(1 => REnt'(Val, Val));
5006 -- Identifier (other than static expression) case
5008 else pragma Assert (Nkind (N) = N_Identifier);
5012 if Is_Type (Entity (N)) then
5014 -- If type has predicates, process them
5016 if Has_Predicates (Entity (N)) then
5017 return Stat_Pred (Entity (N));
5019 -- For static subtype without predicates, get range
5021 elsif Is_Static_Subtype (Entity (N)) then
5022 SLo := Expr_Value (Type_Low_Bound (Entity (N)));
5023 SHi := Expr_Value (Type_High_Bound (Entity (N)));
5024 return RList'(1 => REnt'(SLo, SHi));
5026 -- Any other type makes us non-static
5032 -- Any other kind of identifier in predicate (e.g. a non-static
5033 -- expression value) means this is not a static predicate.
5039 end Membership_Entry;
5045 function Stat_Pred (Typ : Entity_Id) return RList is
5047 -- Not static if type does not have static predicates
5049 if not Has_Predicates (Typ)
5050 or else No (Static_Predicate (Typ))
5055 -- Otherwise we convert the predicate list to a range list
5058 Result : RList (1 .. List_Length (Static_Predicate (Typ)));
5062 P := First (Static_Predicate (Typ));
5063 for J in Result'Range loop
5064 Result (J) := REnt'(Lo_Val (P), Hi_Val (P));
5072 -- Start of processing for Build_Static_Predicate
5075 -- Now analyze the expression to see if it is a static predicate
5078 Ranges : constant RList := Get_RList (Expr);
5079 -- Range list from expression if it is static
5084 -- Convert range list into a form for the static predicate. In the
5085 -- Ranges array, we just have raw ranges, these must be converted
5086 -- to properly typed and analyzed static expressions or range nodes.
5088 -- Note: here we limit ranges to the ranges of the subtype, so that
5089 -- a predicate is always false for values outside the subtype. That
5090 -- seems fine, such values are invalid anyway, and considering them
5091 -- to fail the predicate seems allowed and friendly, and furthermore
5092 -- simplifies processing for case statements and loops.
5096 for J in Ranges'Range loop
5098 Lo : Uint := Ranges (J).Lo;
5099 Hi : Uint := Ranges (J).Hi;
5102 -- Ignore completely out of range entry
5104 if Hi < TLo or else Lo > THi then
5107 -- Otherwise process entry
5110 -- Adjust out of range value to subtype range
5120 -- Convert range into required form
5123 Append_To (Plist, Build_Val (Lo));
5125 Append_To (Plist, Build_Range (Lo, Hi));
5131 -- Processing was successful and all entries were static, so now we
5132 -- can store the result as the predicate list.
5134 Set_Static_Predicate (Typ, Plist);
5136 -- The processing for static predicates put the expression into
5137 -- canonical form as a series of ranges. It also eliminated
5138 -- duplicates and collapsed and combined ranges. We might as well
5139 -- replace the alternatives list of the right operand of the
5140 -- membership test with the static predicate list, which will
5141 -- usually be more efficient.
5144 New_Alts : constant List_Id := New_List;
5149 Old_Node := First (Plist);
5150 while Present (Old_Node) loop
5151 New_Node := New_Copy (Old_Node);
5153 if Nkind (New_Node) = N_Range then
5154 Set_Low_Bound (New_Node, New_Copy (Low_Bound (Old_Node)));
5155 Set_High_Bound (New_Node, New_Copy (High_Bound (Old_Node)));
5158 Append_To (New_Alts, New_Node);
5162 -- If empty list, replace by False
5164 if Is_Empty_List (New_Alts) then
5165 Rewrite (Expr, New_Occurrence_Of (Standard_False, Loc));
5167 -- Else replace by set membership test
5172 Left_Opnd => Make_Identifier (Loc, Nam),
5173 Right_Opnd => Empty,
5174 Alternatives => New_Alts));
5176 -- Resolve new expression in function context
5178 Install_Formals (Predicate_Function (Typ));
5179 Push_Scope (Predicate_Function (Typ));
5180 Analyze_And_Resolve (Expr, Standard_Boolean);
5186 -- If non-static, return doing nothing
5191 end Build_Static_Predicate;
5193 -----------------------------------------
5194 -- Check_Aspect_At_End_Of_Declarations --
5195 -----------------------------------------
5197 procedure Check_Aspect_At_End_Of_Declarations (ASN : Node_Id) is
5198 Ent : constant Entity_Id := Entity (ASN);
5199 Ident : constant Node_Id := Identifier (ASN);
5201 Freeze_Expr : constant Node_Id := Expression (ASN);
5202 -- Preanalyzed expression from call to Check_Aspect_At_Freeze_Point
5204 End_Decl_Expr : constant Node_Id := Entity (Ident);
5205 -- Expression to be analyzed at end of declarations
5207 T : constant Entity_Id := Etype (Freeze_Expr);
5208 -- Type required for preanalyze call
5210 A_Id : constant Aspect_Id := Get_Aspect_Id (Chars (Ident));
5213 -- Set False if error
5215 -- On entry to this procedure, Entity (Ident) contains a copy of the
5216 -- original expression from the aspect, saved for this purpose, and
5217 -- but Expression (Ident) is a preanalyzed copy of the expression,
5218 -- preanalyzed just after the freeze point.
5221 -- Case of stream attributes, just have to compare entities
5223 if A_Id = Aspect_Input or else
5224 A_Id = Aspect_Output or else
5225 A_Id = Aspect_Read or else
5228 Analyze (End_Decl_Expr);
5229 Err := Entity (End_Decl_Expr) /= Entity (Freeze_Expr);
5234 Preanalyze_Spec_Expression (End_Decl_Expr, T);
5235 Err := not Fully_Conformant_Expressions (End_Decl_Expr, Freeze_Expr);
5238 -- Output error message if error
5242 ("visibility of aspect for& changes after freeze point",
5245 ("?info: & is frozen here, aspects evaluated at this point",
5246 Freeze_Node (Ent), Ent);
5248 end Check_Aspect_At_End_Of_Declarations;
5250 ----------------------------------
5251 -- Check_Aspect_At_Freeze_Point --
5252 ----------------------------------
5254 procedure Check_Aspect_At_Freeze_Point (ASN : Node_Id) is
5255 Ident : constant Node_Id := Identifier (ASN);
5256 -- Identifier (use Entity field to save expression)
5259 -- Type required for preanalyze call
5261 A_Id : constant Aspect_Id := Get_Aspect_Id (Chars (Ident));
5264 -- On entry to this procedure, Entity (Ident) contains a copy of the
5265 -- original expression from the aspect, saved for this purpose.
5267 -- On exit from this procedure Entity (Ident) is unchanged, still
5268 -- containing that copy, but Expression (Ident) is a preanalyzed copy
5269 -- of the expression, preanalyzed just after the freeze point.
5271 -- Make a copy of the expression to be preanalyed
5273 Set_Expression (ASN, New_Copy_Tree (Entity (Ident)));
5275 -- Find type for preanalyze call
5279 -- No_Aspect should be impossible
5282 raise Program_Error;
5284 -- Library unit aspects should be impossible (never delayed)
5286 when Library_Unit_Aspects =>
5287 raise Program_Error;
5289 -- Aspects taking an optional boolean argument. Should be impossible
5290 -- since these are never delayed.
5292 when Boolean_Aspects =>
5293 raise Program_Error;
5295 -- Default_Value is resolved with the type entity in question
5297 when Aspect_Default_Value =>
5300 -- Default_Component_Value is resolved with the component type
5302 when Aspect_Default_Component_Value =>
5303 T := Component_Type (Entity (ASN));
5305 -- Aspects corresponding to attribute definition clauses
5307 when Aspect_Address =>
5308 T := RTE (RE_Address);
5310 when Aspect_Bit_Order =>
5311 T := RTE (RE_Bit_Order);
5313 when Aspect_External_Tag =>
5314 T := Standard_String;
5316 when Aspect_Storage_Pool =>
5317 T := Class_Wide_Type (RTE (RE_Root_Storage_Pool));
5321 Aspect_Component_Size |
5322 Aspect_Machine_Radix |
5323 Aspect_Object_Size |
5325 Aspect_Storage_Size |
5326 Aspect_Stream_Size |
5327 Aspect_Value_Size =>
5330 -- Stream attribute. Special case, the expression is just an entity
5331 -- that does not need any resolution, so just analyze.
5337 Analyze (Expression (ASN));
5340 -- Suppress/Unsupress/Warnings should never be delayed
5342 when Aspect_Suppress |
5345 raise Program_Error;
5347 -- Pre/Post/Invariant/Predicate take boolean expressions
5349 when Aspect_Dynamic_Predicate |
5352 Aspect_Precondition |
5354 Aspect_Postcondition |
5356 Aspect_Static_Predicate |
5357 Aspect_Type_Invariant =>
5358 T := Standard_Boolean;
5361 -- Do the preanalyze call
5363 Preanalyze_Spec_Expression (Expression (ASN), T);
5364 end Check_Aspect_At_Freeze_Point;
5366 -----------------------------------
5367 -- Check_Constant_Address_Clause --
5368 -----------------------------------
5370 procedure Check_Constant_Address_Clause
5374 procedure Check_At_Constant_Address (Nod : Node_Id);
5375 -- Checks that the given node N represents a name whose 'Address is
5376 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
5377 -- address value is the same at the point of declaration of U_Ent and at
5378 -- the time of elaboration of the address clause.
5380 procedure Check_Expr_Constants (Nod : Node_Id);
5381 -- Checks that Nod meets the requirements for a constant address clause
5382 -- in the sense of the enclosing procedure.
5384 procedure Check_List_Constants (Lst : List_Id);
5385 -- Check that all elements of list Lst meet the requirements for a
5386 -- constant address clause in the sense of the enclosing procedure.
5388 -------------------------------
5389 -- Check_At_Constant_Address --
5390 -------------------------------
5392 procedure Check_At_Constant_Address (Nod : Node_Id) is
5394 if Is_Entity_Name (Nod) then
5395 if Present (Address_Clause (Entity ((Nod)))) then
5397 ("invalid address clause for initialized object &!",
5400 ("address for& cannot" &
5401 " depend on another address clause! (RM 13.1(22))!",
5404 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
5405 and then Sloc (U_Ent) < Sloc (Entity (Nod))
5408 ("invalid address clause for initialized object &!",
5410 Error_Msg_Node_2 := U_Ent;
5412 ("\& must be defined before & (RM 13.1(22))!",
5416 elsif Nkind (Nod) = N_Selected_Component then
5418 T : constant Entity_Id := Etype (Prefix (Nod));
5421 if (Is_Record_Type (T)
5422 and then Has_Discriminants (T))
5425 and then Is_Record_Type (Designated_Type (T))
5426 and then Has_Discriminants (Designated_Type (T)))
5429 ("invalid address clause for initialized object &!",
5432 ("\address cannot depend on component" &
5433 " of discriminated record (RM 13.1(22))!",
5436 Check_At_Constant_Address (Prefix (Nod));
5440 elsif Nkind (Nod) = N_Indexed_Component then
5441 Check_At_Constant_Address (Prefix (Nod));
5442 Check_List_Constants (Expressions (Nod));
5445 Check_Expr_Constants (Nod);
5447 end Check_At_Constant_Address;
5449 --------------------------
5450 -- Check_Expr_Constants --
5451 --------------------------
5453 procedure Check_Expr_Constants (Nod : Node_Id) is
5454 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
5455 Ent : Entity_Id := Empty;
5458 if Nkind (Nod) in N_Has_Etype
5459 and then Etype (Nod) = Any_Type
5465 when N_Empty | N_Error =>
5468 when N_Identifier | N_Expanded_Name =>
5469 Ent := Entity (Nod);
5471 -- We need to look at the original node if it is different
5472 -- from the node, since we may have rewritten things and
5473 -- substituted an identifier representing the rewrite.
5475 if Original_Node (Nod) /= Nod then
5476 Check_Expr_Constants (Original_Node (Nod));
5478 -- If the node is an object declaration without initial
5479 -- value, some code has been expanded, and the expression
5480 -- is not constant, even if the constituents might be
5481 -- acceptable, as in A'Address + offset.
5483 if Ekind (Ent) = E_Variable
5485 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
5487 No (Expression (Declaration_Node (Ent)))
5490 ("invalid address clause for initialized object &!",
5493 -- If entity is constant, it may be the result of expanding
5494 -- a check. We must verify that its declaration appears
5495 -- before the object in question, else we also reject the
5498 elsif Ekind (Ent) = E_Constant
5499 and then In_Same_Source_Unit (Ent, U_Ent)
5500 and then Sloc (Ent) > Loc_U_Ent
5503 ("invalid address clause for initialized object &!",
5510 -- Otherwise look at the identifier and see if it is OK
5512 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
5513 or else Is_Type (Ent)
5518 Ekind (Ent) = E_Constant
5520 Ekind (Ent) = E_In_Parameter
5522 -- This is the case where we must have Ent defined before
5523 -- U_Ent. Clearly if they are in different units this
5524 -- requirement is met since the unit containing Ent is
5525 -- already processed.
5527 if not In_Same_Source_Unit (Ent, U_Ent) then
5530 -- Otherwise location of Ent must be before the location
5531 -- of U_Ent, that's what prior defined means.
5533 elsif Sloc (Ent) < Loc_U_Ent then
5538 ("invalid address clause for initialized object &!",
5540 Error_Msg_Node_2 := U_Ent;
5542 ("\& must be defined before & (RM 13.1(22))!",
5546 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
5547 Check_Expr_Constants (Original_Node (Nod));
5551 ("invalid address clause for initialized object &!",
5554 if Comes_From_Source (Ent) then
5556 ("\reference to variable& not allowed"
5557 & " (RM 13.1(22))!", Nod, Ent);
5560 ("non-static expression not allowed"
5561 & " (RM 13.1(22))!", Nod);
5565 when N_Integer_Literal =>
5567 -- If this is a rewritten unchecked conversion, in a system
5568 -- where Address is an integer type, always use the base type
5569 -- for a literal value. This is user-friendly and prevents
5570 -- order-of-elaboration issues with instances of unchecked
5573 if Nkind (Original_Node (Nod)) = N_Function_Call then
5574 Set_Etype (Nod, Base_Type (Etype (Nod)));
5577 when N_Real_Literal |
5579 N_Character_Literal =>
5583 Check_Expr_Constants (Low_Bound (Nod));
5584 Check_Expr_Constants (High_Bound (Nod));
5586 when N_Explicit_Dereference =>
5587 Check_Expr_Constants (Prefix (Nod));
5589 when N_Indexed_Component =>
5590 Check_Expr_Constants (Prefix (Nod));
5591 Check_List_Constants (Expressions (Nod));
5594 Check_Expr_Constants (Prefix (Nod));
5595 Check_Expr_Constants (Discrete_Range (Nod));
5597 when N_Selected_Component =>
5598 Check_Expr_Constants (Prefix (Nod));
5600 when N_Attribute_Reference =>
5601 if Attribute_Name (Nod) = Name_Address
5603 Attribute_Name (Nod) = Name_Access
5605 Attribute_Name (Nod) = Name_Unchecked_Access
5607 Attribute_Name (Nod) = Name_Unrestricted_Access
5609 Check_At_Constant_Address (Prefix (Nod));
5612 Check_Expr_Constants (Prefix (Nod));
5613 Check_List_Constants (Expressions (Nod));
5617 Check_List_Constants (Component_Associations (Nod));
5618 Check_List_Constants (Expressions (Nod));
5620 when N_Component_Association =>
5621 Check_Expr_Constants (Expression (Nod));
5623 when N_Extension_Aggregate =>
5624 Check_Expr_Constants (Ancestor_Part (Nod));
5625 Check_List_Constants (Component_Associations (Nod));
5626 Check_List_Constants (Expressions (Nod));
5631 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
5632 Check_Expr_Constants (Left_Opnd (Nod));
5633 Check_Expr_Constants (Right_Opnd (Nod));
5636 Check_Expr_Constants (Right_Opnd (Nod));
5638 when N_Type_Conversion |
5639 N_Qualified_Expression |
5641 Check_Expr_Constants (Expression (Nod));
5643 when N_Unchecked_Type_Conversion =>
5644 Check_Expr_Constants (Expression (Nod));
5646 -- If this is a rewritten unchecked conversion, subtypes in
5647 -- this node are those created within the instance. To avoid
5648 -- order of elaboration issues, replace them with their base
5649 -- types. Note that address clauses can cause order of
5650 -- elaboration problems because they are elaborated by the
5651 -- back-end at the point of definition, and may mention
5652 -- entities declared in between (as long as everything is
5653 -- static). It is user-friendly to allow unchecked conversions
5656 if Nkind (Original_Node (Nod)) = N_Function_Call then
5657 Set_Etype (Expression (Nod),
5658 Base_Type (Etype (Expression (Nod))));
5659 Set_Etype (Nod, Base_Type (Etype (Nod)));
5662 when N_Function_Call =>
5663 if not Is_Pure (Entity (Name (Nod))) then
5665 ("invalid address clause for initialized object &!",
5669 ("\function & is not pure (RM 13.1(22))!",
5670 Nod, Entity (Name (Nod)));
5673 Check_List_Constants (Parameter_Associations (Nod));
5676 when N_Parameter_Association =>
5677 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
5681 ("invalid address clause for initialized object &!",
5684 ("\must be constant defined before& (RM 13.1(22))!",
5687 end Check_Expr_Constants;
5689 --------------------------
5690 -- Check_List_Constants --
5691 --------------------------
5693 procedure Check_List_Constants (Lst : List_Id) is
5697 if Present (Lst) then
5698 Nod1 := First (Lst);
5699 while Present (Nod1) loop
5700 Check_Expr_Constants (Nod1);
5704 end Check_List_Constants;
5706 -- Start of processing for Check_Constant_Address_Clause
5709 -- If rep_clauses are to be ignored, no need for legality checks. In
5710 -- particular, no need to pester user about rep clauses that violate
5711 -- the rule on constant addresses, given that these clauses will be
5712 -- removed by Freeze before they reach the back end.
5714 if not Ignore_Rep_Clauses then
5715 Check_Expr_Constants (Expr);
5717 end Check_Constant_Address_Clause;
5719 ----------------------------------------
5720 -- Check_Record_Representation_Clause --
5721 ----------------------------------------
5723 procedure Check_Record_Representation_Clause (N : Node_Id) is
5724 Loc : constant Source_Ptr := Sloc (N);
5725 Ident : constant Node_Id := Identifier (N);
5726 Rectype : Entity_Id;
5731 Hbit : Uint := Uint_0;
5735 Max_Bit_So_Far : Uint;
5736 -- Records the maximum bit position so far. If all field positions
5737 -- are monotonically increasing, then we can skip the circuit for
5738 -- checking for overlap, since no overlap is possible.
5740 Tagged_Parent : Entity_Id := Empty;
5741 -- This is set in the case of a derived tagged type for which we have
5742 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
5743 -- positioned by record representation clauses). In this case we must
5744 -- check for overlap between components of this tagged type, and the
5745 -- components of its parent. Tagged_Parent will point to this parent
5746 -- type. For all other cases Tagged_Parent is left set to Empty.
5748 Parent_Last_Bit : Uint;
5749 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
5750 -- last bit position for any field in the parent type. We only need to
5751 -- check overlap for fields starting below this point.
5753 Overlap_Check_Required : Boolean;
5754 -- Used to keep track of whether or not an overlap check is required
5756 Overlap_Detected : Boolean := False;
5757 -- Set True if an overlap is detected
5759 Ccount : Natural := 0;
5760 -- Number of component clauses in record rep clause
5762 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
5763 -- Given two entities for record components or discriminants, checks
5764 -- if they have overlapping component clauses and issues errors if so.
5766 procedure Find_Component;
5767 -- Finds component entity corresponding to current component clause (in
5768 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
5769 -- start/stop bits for the field. If there is no matching component or
5770 -- if the matching component does not have a component clause, then
5771 -- that's an error and Comp is set to Empty, but no error message is
5772 -- issued, since the message was already given. Comp is also set to
5773 -- Empty if the current "component clause" is in fact a pragma.
5775 -----------------------------
5776 -- Check_Component_Overlap --
5777 -----------------------------
5779 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
5780 CC1 : constant Node_Id := Component_Clause (C1_Ent);
5781 CC2 : constant Node_Id := Component_Clause (C2_Ent);
5784 if Present (CC1) and then Present (CC2) then
5786 -- Exclude odd case where we have two tag fields in the same
5787 -- record, both at location zero. This seems a bit strange, but
5788 -- it seems to happen in some circumstances, perhaps on an error.
5790 if Chars (C1_Ent) = Name_uTag
5792 Chars (C2_Ent) = Name_uTag
5797 -- Here we check if the two fields overlap
5800 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
5801 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
5802 E1 : constant Uint := S1 + Esize (C1_Ent);
5803 E2 : constant Uint := S2 + Esize (C2_Ent);
5806 if E2 <= S1 or else E1 <= S2 then
5809 Error_Msg_Node_2 := Component_Name (CC2);
5810 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
5811 Error_Msg_Node_1 := Component_Name (CC1);
5813 ("component& overlaps & #", Component_Name (CC1));
5814 Overlap_Detected := True;
5818 end Check_Component_Overlap;
5820 --------------------
5821 -- Find_Component --
5822 --------------------
5824 procedure Find_Component is
5826 procedure Search_Component (R : Entity_Id);
5827 -- Search components of R for a match. If found, Comp is set.
5829 ----------------------
5830 -- Search_Component --
5831 ----------------------
5833 procedure Search_Component (R : Entity_Id) is
5835 Comp := First_Component_Or_Discriminant (R);
5836 while Present (Comp) loop
5838 -- Ignore error of attribute name for component name (we
5839 -- already gave an error message for this, so no need to
5842 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
5845 exit when Chars (Comp) = Chars (Component_Name (CC));
5848 Next_Component_Or_Discriminant (Comp);
5850 end Search_Component;
5852 -- Start of processing for Find_Component
5855 -- Return with Comp set to Empty if we have a pragma
5857 if Nkind (CC) = N_Pragma then
5862 -- Search current record for matching component
5864 Search_Component (Rectype);
5866 -- If not found, maybe component of base type that is absent from
5867 -- statically constrained first subtype.
5870 Search_Component (Base_Type (Rectype));
5873 -- If no component, or the component does not reference the component
5874 -- clause in question, then there was some previous error for which
5875 -- we already gave a message, so just return with Comp Empty.
5878 or else Component_Clause (Comp) /= CC
5882 -- Normal case where we have a component clause
5885 Fbit := Component_Bit_Offset (Comp);
5886 Lbit := Fbit + Esize (Comp) - 1;
5890 -- Start of processing for Check_Record_Representation_Clause
5894 Rectype := Entity (Ident);
5896 if Rectype = Any_Type then
5899 Rectype := Underlying_Type (Rectype);
5902 -- See if we have a fully repped derived tagged type
5905 PS : constant Entity_Id := Parent_Subtype (Rectype);
5908 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
5909 Tagged_Parent := PS;
5911 -- Find maximum bit of any component of the parent type
5913 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
5914 Pcomp := First_Entity (Tagged_Parent);
5915 while Present (Pcomp) loop
5916 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
5917 if Component_Bit_Offset (Pcomp) /= No_Uint
5918 and then Known_Static_Esize (Pcomp)
5923 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
5926 Next_Entity (Pcomp);
5932 -- All done if no component clauses
5934 CC := First (Component_Clauses (N));
5940 -- If a tag is present, then create a component clause that places it
5941 -- at the start of the record (otherwise gigi may place it after other
5942 -- fields that have rep clauses).
5944 Fent := First_Entity (Rectype);
5946 if Nkind (Fent) = N_Defining_Identifier
5947 and then Chars (Fent) = Name_uTag
5949 Set_Component_Bit_Offset (Fent, Uint_0);
5950 Set_Normalized_Position (Fent, Uint_0);
5951 Set_Normalized_First_Bit (Fent, Uint_0);
5952 Set_Normalized_Position_Max (Fent, Uint_0);
5953 Init_Esize (Fent, System_Address_Size);
5955 Set_Component_Clause (Fent,
5956 Make_Component_Clause (Loc,
5957 Component_Name => Make_Identifier (Loc, Name_uTag),
5959 Position => Make_Integer_Literal (Loc, Uint_0),
5960 First_Bit => Make_Integer_Literal (Loc, Uint_0),
5962 Make_Integer_Literal (Loc,
5963 UI_From_Int (System_Address_Size))));
5965 Ccount := Ccount + 1;
5968 Max_Bit_So_Far := Uint_Minus_1;
5969 Overlap_Check_Required := False;
5971 -- Process the component clauses
5973 while Present (CC) loop
5976 if Present (Comp) then
5977 Ccount := Ccount + 1;
5979 -- We need a full overlap check if record positions non-monotonic
5981 if Fbit <= Max_Bit_So_Far then
5982 Overlap_Check_Required := True;
5985 Max_Bit_So_Far := Lbit;
5987 -- Check bit position out of range of specified size
5989 if Has_Size_Clause (Rectype)
5990 and then Esize (Rectype) <= Lbit
5993 ("bit number out of range of specified size",
5996 -- Check for overlap with tag field
5999 if Is_Tagged_Type (Rectype)
6000 and then Fbit < System_Address_Size
6003 ("component overlaps tag field of&",
6004 Component_Name (CC), Rectype);
6005 Overlap_Detected := True;
6013 -- Check parent overlap if component might overlap parent field
6015 if Present (Tagged_Parent)
6016 and then Fbit <= Parent_Last_Bit
6018 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
6019 while Present (Pcomp) loop
6020 if not Is_Tag (Pcomp)
6021 and then Chars (Pcomp) /= Name_uParent
6023 Check_Component_Overlap (Comp, Pcomp);
6026 Next_Component_Or_Discriminant (Pcomp);
6034 -- Now that we have processed all the component clauses, check for
6035 -- overlap. We have to leave this till last, since the components can
6036 -- appear in any arbitrary order in the representation clause.
6038 -- We do not need this check if all specified ranges were monotonic,
6039 -- as recorded by Overlap_Check_Required being False at this stage.
6041 -- This first section checks if there are any overlapping entries at
6042 -- all. It does this by sorting all entries and then seeing if there are
6043 -- any overlaps. If there are none, then that is decisive, but if there
6044 -- are overlaps, they may still be OK (they may result from fields in
6045 -- different variants).
6047 if Overlap_Check_Required then
6048 Overlap_Check1 : declare
6050 OC_Fbit : array (0 .. Ccount) of Uint;
6051 -- First-bit values for component clauses, the value is the offset
6052 -- of the first bit of the field from start of record. The zero
6053 -- entry is for use in sorting.
6055 OC_Lbit : array (0 .. Ccount) of Uint;
6056 -- Last-bit values for component clauses, the value is the offset
6057 -- of the last bit of the field from start of record. The zero
6058 -- entry is for use in sorting.
6060 OC_Count : Natural := 0;
6061 -- Count of entries in OC_Fbit and OC_Lbit
6063 function OC_Lt (Op1, Op2 : Natural) return Boolean;
6064 -- Compare routine for Sort
6066 procedure OC_Move (From : Natural; To : Natural);
6067 -- Move routine for Sort
6069 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
6075 function OC_Lt (Op1, Op2 : Natural) return Boolean is
6077 return OC_Fbit (Op1) < OC_Fbit (Op2);
6084 procedure OC_Move (From : Natural; To : Natural) is
6086 OC_Fbit (To) := OC_Fbit (From);
6087 OC_Lbit (To) := OC_Lbit (From);
6090 -- Start of processing for Overlap_Check
6093 CC := First (Component_Clauses (N));
6094 while Present (CC) loop
6096 -- Exclude component clause already marked in error
6098 if not Error_Posted (CC) then
6101 if Present (Comp) then
6102 OC_Count := OC_Count + 1;
6103 OC_Fbit (OC_Count) := Fbit;
6104 OC_Lbit (OC_Count) := Lbit;
6111 Sorting.Sort (OC_Count);
6113 Overlap_Check_Required := False;
6114 for J in 1 .. OC_Count - 1 loop
6115 if OC_Lbit (J) >= OC_Fbit (J + 1) then
6116 Overlap_Check_Required := True;
6123 -- If Overlap_Check_Required is still True, then we have to do the full
6124 -- scale overlap check, since we have at least two fields that do
6125 -- overlap, and we need to know if that is OK since they are in
6126 -- different variant, or whether we have a definite problem.
6128 if Overlap_Check_Required then
6129 Overlap_Check2 : declare
6130 C1_Ent, C2_Ent : Entity_Id;
6131 -- Entities of components being checked for overlap
6134 -- Component_List node whose Component_Items are being checked
6137 -- Component declaration for component being checked
6140 C1_Ent := First_Entity (Base_Type (Rectype));
6142 -- Loop through all components in record. For each component check
6143 -- for overlap with any of the preceding elements on the component
6144 -- list containing the component and also, if the component is in
6145 -- a variant, check against components outside the case structure.
6146 -- This latter test is repeated recursively up the variant tree.
6148 Main_Component_Loop : while Present (C1_Ent) loop
6149 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
6150 goto Continue_Main_Component_Loop;
6153 -- Skip overlap check if entity has no declaration node. This
6154 -- happens with discriminants in constrained derived types.
6155 -- Possibly we are missing some checks as a result, but that
6156 -- does not seem terribly serious.
6158 if No (Declaration_Node (C1_Ent)) then
6159 goto Continue_Main_Component_Loop;
6162 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
6164 -- Loop through component lists that need checking. Check the
6165 -- current component list and all lists in variants above us.
6167 Component_List_Loop : loop
6169 -- If derived type definition, go to full declaration
6170 -- If at outer level, check discriminants if there are any.
6172 if Nkind (Clist) = N_Derived_Type_Definition then
6173 Clist := Parent (Clist);
6176 -- Outer level of record definition, check discriminants
6178 if Nkind_In (Clist, N_Full_Type_Declaration,
6179 N_Private_Type_Declaration)
6181 if Has_Discriminants (Defining_Identifier (Clist)) then
6183 First_Discriminant (Defining_Identifier (Clist));
6184 while Present (C2_Ent) loop
6185 exit when C1_Ent = C2_Ent;
6186 Check_Component_Overlap (C1_Ent, C2_Ent);
6187 Next_Discriminant (C2_Ent);
6191 -- Record extension case
6193 elsif Nkind (Clist) = N_Derived_Type_Definition then
6196 -- Otherwise check one component list
6199 Citem := First (Component_Items (Clist));
6200 while Present (Citem) loop
6201 if Nkind (Citem) = N_Component_Declaration then
6202 C2_Ent := Defining_Identifier (Citem);
6203 exit when C1_Ent = C2_Ent;
6204 Check_Component_Overlap (C1_Ent, C2_Ent);
6211 -- Check for variants above us (the parent of the Clist can
6212 -- be a variant, in which case its parent is a variant part,
6213 -- and the parent of the variant part is a component list
6214 -- whose components must all be checked against the current
6215 -- component for overlap).
6217 if Nkind (Parent (Clist)) = N_Variant then
6218 Clist := Parent (Parent (Parent (Clist)));
6220 -- Check for possible discriminant part in record, this
6221 -- is treated essentially as another level in the
6222 -- recursion. For this case the parent of the component
6223 -- list is the record definition, and its parent is the
6224 -- full type declaration containing the discriminant
6227 elsif Nkind (Parent (Clist)) = N_Record_Definition then
6228 Clist := Parent (Parent ((Clist)));
6230 -- If neither of these two cases, we are at the top of
6234 exit Component_List_Loop;
6236 end loop Component_List_Loop;
6238 <<Continue_Main_Component_Loop>>
6239 Next_Entity (C1_Ent);
6241 end loop Main_Component_Loop;
6245 -- The following circuit deals with warning on record holes (gaps). We
6246 -- skip this check if overlap was detected, since it makes sense for the
6247 -- programmer to fix this illegality before worrying about warnings.
6249 if not Overlap_Detected and Warn_On_Record_Holes then
6250 Record_Hole_Check : declare
6251 Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype));
6252 -- Full declaration of record type
6254 procedure Check_Component_List
6258 -- Check component list CL for holes. The starting bit should be
6259 -- Sbit. which is zero for the main record component list and set
6260 -- appropriately for recursive calls for variants. DS is set to
6261 -- a list of discriminant specifications to be included in the
6262 -- consideration of components. It is No_List if none to consider.
6264 --------------------------
6265 -- Check_Component_List --
6266 --------------------------
6268 procedure Check_Component_List
6276 Compl := Integer (List_Length (Component_Items (CL)));
6278 if DS /= No_List then
6279 Compl := Compl + Integer (List_Length (DS));
6283 Comps : array (Natural range 0 .. Compl) of Entity_Id;
6284 -- Gather components (zero entry is for sort routine)
6286 Ncomps : Natural := 0;
6287 -- Number of entries stored in Comps (starting at Comps (1))
6290 -- One component item or discriminant specification
6293 -- Starting bit for next component
6301 function Lt (Op1, Op2 : Natural) return Boolean;
6302 -- Compare routine for Sort
6304 procedure Move (From : Natural; To : Natural);
6305 -- Move routine for Sort
6307 package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
6313 function Lt (Op1, Op2 : Natural) return Boolean is
6315 return Component_Bit_Offset (Comps (Op1))
6317 Component_Bit_Offset (Comps (Op2));
6324 procedure Move (From : Natural; To : Natural) is
6326 Comps (To) := Comps (From);
6330 -- Gather discriminants into Comp
6332 if DS /= No_List then
6333 Citem := First (DS);
6334 while Present (Citem) loop
6335 if Nkind (Citem) = N_Discriminant_Specification then
6337 Ent : constant Entity_Id :=
6338 Defining_Identifier (Citem);
6340 if Ekind (Ent) = E_Discriminant then
6341 Ncomps := Ncomps + 1;
6342 Comps (Ncomps) := Ent;
6351 -- Gather component entities into Comp
6353 Citem := First (Component_Items (CL));
6354 while Present (Citem) loop
6355 if Nkind (Citem) = N_Component_Declaration then
6356 Ncomps := Ncomps + 1;
6357 Comps (Ncomps) := Defining_Identifier (Citem);
6363 -- Now sort the component entities based on the first bit.
6364 -- Note we already know there are no overlapping components.
6366 Sorting.Sort (Ncomps);
6368 -- Loop through entries checking for holes
6371 for J in 1 .. Ncomps loop
6373 Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
6375 if Error_Msg_Uint_1 > 0 then
6377 ("?^-bit gap before component&",
6378 Component_Name (Component_Clause (CEnt)), CEnt);
6381 Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
6384 -- Process variant parts recursively if present
6386 if Present (Variant_Part (CL)) then
6387 Variant := First (Variants (Variant_Part (CL)));
6388 while Present (Variant) loop
6389 Check_Component_List
6390 (Component_List (Variant), Nbit, No_List);
6395 end Check_Component_List;
6397 -- Start of processing for Record_Hole_Check
6404 if Is_Tagged_Type (Rectype) then
6405 Sbit := UI_From_Int (System_Address_Size);
6410 if Nkind (Decl) = N_Full_Type_Declaration
6411 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
6413 Check_Component_List
6414 (Component_List (Type_Definition (Decl)),
6416 Discriminant_Specifications (Decl));
6419 end Record_Hole_Check;
6422 -- For records that have component clauses for all components, and whose
6423 -- size is less than or equal to 32, we need to know the size in the
6424 -- front end to activate possible packed array processing where the
6425 -- component type is a record.
6427 -- At this stage Hbit + 1 represents the first unused bit from all the
6428 -- component clauses processed, so if the component clauses are
6429 -- complete, then this is the length of the record.
6431 -- For records longer than System.Storage_Unit, and for those where not
6432 -- all components have component clauses, the back end determines the
6433 -- length (it may for example be appropriate to round up the size
6434 -- to some convenient boundary, based on alignment considerations, etc).
6436 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
6438 -- Nothing to do if at least one component has no component clause
6440 Comp := First_Component_Or_Discriminant (Rectype);
6441 while Present (Comp) loop
6442 exit when No (Component_Clause (Comp));
6443 Next_Component_Or_Discriminant (Comp);
6446 -- If we fall out of loop, all components have component clauses
6447 -- and so we can set the size to the maximum value.
6450 Set_RM_Size (Rectype, Hbit + 1);
6453 end Check_Record_Representation_Clause;
6459 procedure Check_Size
6463 Biased : out Boolean)
6465 UT : constant Entity_Id := Underlying_Type (T);
6471 -- Dismiss cases for generic types or types with previous errors
6474 or else UT = Any_Type
6475 or else Is_Generic_Type (UT)
6476 or else Is_Generic_Type (Root_Type (UT))
6480 -- Check case of bit packed array
6482 elsif Is_Array_Type (UT)
6483 and then Known_Static_Component_Size (UT)
6484 and then Is_Bit_Packed_Array (UT)
6492 Asiz := Component_Size (UT);
6493 Indx := First_Index (UT);
6495 Ityp := Etype (Indx);
6497 -- If non-static bound, then we are not in the business of
6498 -- trying to check the length, and indeed an error will be
6499 -- issued elsewhere, since sizes of non-static array types
6500 -- cannot be set implicitly or explicitly.
6502 if not Is_Static_Subtype (Ityp) then
6506 -- Otherwise accumulate next dimension
6508 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
6509 Expr_Value (Type_Low_Bound (Ityp)) +
6513 exit when No (Indx);
6519 Error_Msg_Uint_1 := Asiz;
6521 ("size for& too small, minimum allowed is ^", N, T);
6522 Set_Esize (T, Asiz);
6523 Set_RM_Size (T, Asiz);
6527 -- All other composite types are ignored
6529 elsif Is_Composite_Type (UT) then
6532 -- For fixed-point types, don't check minimum if type is not frozen,
6533 -- since we don't know all the characteristics of the type that can
6534 -- affect the size (e.g. a specified small) till freeze time.
6536 elsif Is_Fixed_Point_Type (UT)
6537 and then not Is_Frozen (UT)
6541 -- Cases for which a minimum check is required
6544 -- Ignore if specified size is correct for the type
6546 if Known_Esize (UT) and then Siz = Esize (UT) then
6550 -- Otherwise get minimum size
6552 M := UI_From_Int (Minimum_Size (UT));
6556 -- Size is less than minimum size, but one possibility remains
6557 -- that we can manage with the new size if we bias the type.
6559 M := UI_From_Int (Minimum_Size (UT, Biased => True));
6562 Error_Msg_Uint_1 := M;
6564 ("size for& too small, minimum allowed is ^", N, T);
6574 -------------------------
6575 -- Get_Alignment_Value --
6576 -------------------------
6578 function Get_Alignment_Value (Expr : Node_Id) return Uint is
6579 Align : constant Uint := Static_Integer (Expr);
6582 if Align = No_Uint then
6585 elsif Align <= 0 then
6586 Error_Msg_N ("alignment value must be positive", Expr);
6590 for J in Int range 0 .. 64 loop
6592 M : constant Uint := Uint_2 ** J;
6595 exit when M = Align;
6599 ("alignment value must be power of 2", Expr);
6607 end Get_Alignment_Value;
6613 procedure Initialize is
6615 Address_Clause_Checks.Init;
6616 Independence_Checks.Init;
6617 Unchecked_Conversions.Init;
6620 -------------------------
6621 -- Is_Operational_Item --
6622 -------------------------
6624 function Is_Operational_Item (N : Node_Id) return Boolean is
6626 if Nkind (N) /= N_Attribute_Definition_Clause then
6630 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
6632 return Id = Attribute_Input
6633 or else Id = Attribute_Output
6634 or else Id = Attribute_Read
6635 or else Id = Attribute_Write
6636 or else Id = Attribute_External_Tag;
6639 end Is_Operational_Item;
6645 function Minimum_Size
6647 Biased : Boolean := False) return Nat
6649 Lo : Uint := No_Uint;
6650 Hi : Uint := No_Uint;
6651 LoR : Ureal := No_Ureal;
6652 HiR : Ureal := No_Ureal;
6653 LoSet : Boolean := False;
6654 HiSet : Boolean := False;
6658 R_Typ : constant Entity_Id := Root_Type (T);
6661 -- If bad type, return 0
6663 if T = Any_Type then
6666 -- For generic types, just return zero. There cannot be any legitimate
6667 -- need to know such a size, but this routine may be called with a
6668 -- generic type as part of normal processing.
6670 elsif Is_Generic_Type (R_Typ)
6671 or else R_Typ = Any_Type
6675 -- Access types. Normally an access type cannot have a size smaller
6676 -- than the size of System.Address. The exception is on VMS, where
6677 -- we have short and long addresses, and it is possible for an access
6678 -- type to have a short address size (and thus be less than the size
6679 -- of System.Address itself). We simply skip the check for VMS, and
6680 -- leave it to the back end to do the check.
6682 elsif Is_Access_Type (T) then
6683 if OpenVMS_On_Target then
6686 return System_Address_Size;
6689 -- Floating-point types
6691 elsif Is_Floating_Point_Type (T) then
6692 return UI_To_Int (Esize (R_Typ));
6696 elsif Is_Discrete_Type (T) then
6698 -- The following loop is looking for the nearest compile time known
6699 -- bounds following the ancestor subtype chain. The idea is to find
6700 -- the most restrictive known bounds information.
6704 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
6709 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
6710 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
6717 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
6718 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
6724 Ancest := Ancestor_Subtype (Ancest);
6727 Ancest := Base_Type (T);
6729 if Is_Generic_Type (Ancest) then
6735 -- Fixed-point types. We can't simply use Expr_Value to get the
6736 -- Corresponding_Integer_Value values of the bounds, since these do not
6737 -- get set till the type is frozen, and this routine can be called
6738 -- before the type is frozen. Similarly the test for bounds being static
6739 -- needs to include the case where we have unanalyzed real literals for
6742 elsif Is_Fixed_Point_Type (T) then
6744 -- The following loop is looking for the nearest compile time known
6745 -- bounds following the ancestor subtype chain. The idea is to find
6746 -- the most restrictive known bounds information.
6750 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
6754 -- Note: In the following two tests for LoSet and HiSet, it may
6755 -- seem redundant to test for N_Real_Literal here since normally
6756 -- one would assume that the test for the value being known at
6757 -- compile time includes this case. However, there is a glitch.
6758 -- If the real literal comes from folding a non-static expression,
6759 -- then we don't consider any non- static expression to be known
6760 -- at compile time if we are in configurable run time mode (needed
6761 -- in some cases to give a clearer definition of what is and what
6762 -- is not accepted). So the test is indeed needed. Without it, we
6763 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
6766 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
6767 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
6769 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
6776 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
6777 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
6779 HiR := Expr_Value_R (Type_High_Bound (Ancest));
6785 Ancest := Ancestor_Subtype (Ancest);
6788 Ancest := Base_Type (T);
6790 if Is_Generic_Type (Ancest) then
6796 Lo := UR_To_Uint (LoR / Small_Value (T));
6797 Hi := UR_To_Uint (HiR / Small_Value (T));
6799 -- No other types allowed
6802 raise Program_Error;
6805 -- Fall through with Hi and Lo set. Deal with biased case
6808 and then not Is_Fixed_Point_Type (T)
6809 and then not (Is_Enumeration_Type (T)
6810 and then Has_Non_Standard_Rep (T)))
6811 or else Has_Biased_Representation (T)
6817 -- Signed case. Note that we consider types like range 1 .. -1 to be
6818 -- signed for the purpose of computing the size, since the bounds have
6819 -- to be accommodated in the base type.
6821 if Lo < 0 or else Hi < 0 then
6825 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
6826 -- Note that we accommodate the case where the bounds cross. This
6827 -- can happen either because of the way the bounds are declared
6828 -- or because of the algorithm in Freeze_Fixed_Point_Type.
6842 -- If both bounds are positive, make sure that both are represen-
6843 -- table in the case where the bounds are crossed. This can happen
6844 -- either because of the way the bounds are declared, or because of
6845 -- the algorithm in Freeze_Fixed_Point_Type.
6851 -- S = size, (can accommodate 0 .. (2**size - 1))
6854 while Hi >= Uint_2 ** S loop
6862 ---------------------------
6863 -- New_Stream_Subprogram --
6864 ---------------------------
6866 procedure New_Stream_Subprogram
6870 Nam : TSS_Name_Type)
6872 Loc : constant Source_Ptr := Sloc (N);
6873 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
6874 Subp_Id : Entity_Id;
6875 Subp_Decl : Node_Id;
6879 Defer_Declaration : constant Boolean :=
6880 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
6881 -- For a tagged type, there is a declaration for each stream attribute
6882 -- at the freeze point, and we must generate only a completion of this
6883 -- declaration. We do the same for private types, because the full view
6884 -- might be tagged. Otherwise we generate a declaration at the point of
6885 -- the attribute definition clause.
6887 function Build_Spec return Node_Id;
6888 -- Used for declaration and renaming declaration, so that this is
6889 -- treated as a renaming_as_body.
6895 function Build_Spec return Node_Id is
6896 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
6899 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
6902 Subp_Id := Make_Defining_Identifier (Loc, Sname);
6904 -- S : access Root_Stream_Type'Class
6906 Formals := New_List (
6907 Make_Parameter_Specification (Loc,
6908 Defining_Identifier =>
6909 Make_Defining_Identifier (Loc, Name_S),
6911 Make_Access_Definition (Loc,
6914 Designated_Type (Etype (F)), Loc))));
6916 if Nam = TSS_Stream_Input then
6917 Spec := Make_Function_Specification (Loc,
6918 Defining_Unit_Name => Subp_Id,
6919 Parameter_Specifications => Formals,
6920 Result_Definition => T_Ref);
6925 Make_Parameter_Specification (Loc,
6926 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
6927 Out_Present => Out_P,
6928 Parameter_Type => T_Ref));
6931 Make_Procedure_Specification (Loc,
6932 Defining_Unit_Name => Subp_Id,
6933 Parameter_Specifications => Formals);
6939 -- Start of processing for New_Stream_Subprogram
6942 F := First_Formal (Subp);
6944 if Ekind (Subp) = E_Procedure then
6945 Etyp := Etype (Next_Formal (F));
6947 Etyp := Etype (Subp);
6950 -- Prepare subprogram declaration and insert it as an action on the
6951 -- clause node. The visibility for this entity is used to test for
6952 -- visibility of the attribute definition clause (in the sense of
6953 -- 8.3(23) as amended by AI-195).
6955 if not Defer_Declaration then
6957 Make_Subprogram_Declaration (Loc,
6958 Specification => Build_Spec);
6960 -- For a tagged type, there is always a visible declaration for each
6961 -- stream TSS (it is a predefined primitive operation), and the
6962 -- completion of this declaration occurs at the freeze point, which is
6963 -- not always visible at places where the attribute definition clause is
6964 -- visible. So, we create a dummy entity here for the purpose of
6965 -- tracking the visibility of the attribute definition clause itself.
6969 Make_Defining_Identifier (Loc, New_External_Name (Sname, 'V'));
6971 Make_Object_Declaration (Loc,
6972 Defining_Identifier => Subp_Id,
6973 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
6976 Insert_Action (N, Subp_Decl);
6977 Set_Entity (N, Subp_Id);
6980 Make_Subprogram_Renaming_Declaration (Loc,
6981 Specification => Build_Spec,
6982 Name => New_Reference_To (Subp, Loc));
6984 if Defer_Declaration then
6985 Set_TSS (Base_Type (Ent), Subp_Id);
6987 Insert_Action (N, Subp_Decl);
6988 Copy_TSS (Subp_Id, Base_Type (Ent));
6990 end New_Stream_Subprogram;
6992 ------------------------
6993 -- Rep_Item_Too_Early --
6994 ------------------------
6996 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
6998 -- Cannot apply non-operational rep items to generic types
7000 if Is_Operational_Item (N) then
7004 and then Is_Generic_Type (Root_Type (T))
7006 Error_Msg_N ("representation item not allowed for generic type", N);
7010 -- Otherwise check for incomplete type
7012 if Is_Incomplete_Or_Private_Type (T)
7013 and then No (Underlying_Type (T))
7015 (Nkind (N) /= N_Pragma
7016 or else Get_Pragma_Id (N) /= Pragma_Import)
7019 ("representation item must be after full type declaration", N);
7022 -- If the type has incomplete components, a representation clause is
7023 -- illegal but stream attributes and Convention pragmas are correct.
7025 elsif Has_Private_Component (T) then
7026 if Nkind (N) = N_Pragma then
7030 ("representation item must appear after type is fully defined",
7037 end Rep_Item_Too_Early;
7039 -----------------------
7040 -- Rep_Item_Too_Late --
7041 -----------------------
7043 function Rep_Item_Too_Late
7046 FOnly : Boolean := False) return Boolean
7049 Parent_Type : Entity_Id;
7052 -- Output the too late message. Note that this is not considered a
7053 -- serious error, since the effect is simply that we ignore the
7054 -- representation clause in this case.
7060 procedure Too_Late is
7062 Error_Msg_N ("|representation item appears too late!", N);
7065 -- Start of processing for Rep_Item_Too_Late
7068 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
7069 -- types, which may be frozen if they appear in a representation clause
7070 -- for a local type.
7073 and then not From_With_Type (T)
7076 S := First_Subtype (T);
7078 if Present (Freeze_Node (S)) then
7080 ("?no more representation items for }", Freeze_Node (S), S);
7085 -- Check for case of non-tagged derived type whose parent either has
7086 -- primitive operations, or is a by reference type (RM 13.1(10)).
7090 and then Is_Derived_Type (T)
7091 and then not Is_Tagged_Type (T)
7093 Parent_Type := Etype (Base_Type (T));
7095 if Has_Primitive_Operations (Parent_Type) then
7098 ("primitive operations already defined for&!", N, Parent_Type);
7101 elsif Is_By_Reference_Type (Parent_Type) then
7104 ("parent type & is a by reference type!", N, Parent_Type);
7109 -- No error, link item into head of chain of rep items for the entity,
7110 -- but avoid chaining if we have an overloadable entity, and the pragma
7111 -- is one that can apply to multiple overloaded entities.
7113 if Is_Overloadable (T)
7114 and then Nkind (N) = N_Pragma
7117 Pname : constant Name_Id := Pragma_Name (N);
7119 if Pname = Name_Convention or else
7120 Pname = Name_Import or else
7121 Pname = Name_Export or else
7122 Pname = Name_External or else
7123 Pname = Name_Interface
7130 Record_Rep_Item (T, N);
7132 end Rep_Item_Too_Late;
7134 -------------------------------------
7135 -- Replace_Type_References_Generic --
7136 -------------------------------------
7138 procedure Replace_Type_References_Generic (N : Node_Id; TName : Name_Id) is
7140 function Replace_Node (N : Node_Id) return Traverse_Result;
7141 -- Processes a single node in the traversal procedure below, checking
7142 -- if node N should be replaced, and if so, doing the replacement.
7144 procedure Replace_Type_Refs is new Traverse_Proc (Replace_Node);
7145 -- This instantiation provides the body of Replace_Type_References
7151 function Replace_Node (N : Node_Id) return Traverse_Result is
7156 -- Case of identifier
7158 if Nkind (N) = N_Identifier then
7160 -- If not the type name, all done with this node
7162 if Chars (N) /= TName then
7165 -- Otherwise do the replacement and we are done with this node
7168 Replace_Type_Reference (N);
7172 -- Case of selected component (which is what a qualification
7173 -- looks like in the unanalyzed tree, which is what we have.
7175 elsif Nkind (N) = N_Selected_Component then
7177 -- If selector name is not our type, keeping going (we might
7178 -- still have an occurrence of the type in the prefix).
7180 if Nkind (Selector_Name (N)) /= N_Identifier
7181 or else Chars (Selector_Name (N)) /= TName
7185 -- Selector name is our type, check qualification
7188 -- Loop through scopes and prefixes, doing comparison
7193 -- Continue if no more scopes or scope with no name
7195 if No (S) or else Nkind (S) not in N_Has_Chars then
7199 -- Do replace if prefix is an identifier matching the
7200 -- scope that we are currently looking at.
7202 if Nkind (P) = N_Identifier
7203 and then Chars (P) = Chars (S)
7205 Replace_Type_Reference (N);
7209 -- Go check scope above us if prefix is itself of the
7210 -- form of a selected component, whose selector matches
7211 -- the scope we are currently looking at.
7213 if Nkind (P) = N_Selected_Component
7214 and then Nkind (Selector_Name (P)) = N_Identifier
7215 and then Chars (Selector_Name (P)) = Chars (S)
7220 -- For anything else, we don't have a match, so keep on
7221 -- going, there are still some weird cases where we may
7222 -- still have a replacement within the prefix.
7230 -- Continue for any other node kind
7238 Replace_Type_Refs (N);
7239 end Replace_Type_References_Generic;
7241 -------------------------
7242 -- Same_Representation --
7243 -------------------------
7245 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
7246 T1 : constant Entity_Id := Underlying_Type (Typ1);
7247 T2 : constant Entity_Id := Underlying_Type (Typ2);
7250 -- A quick check, if base types are the same, then we definitely have
7251 -- the same representation, because the subtype specific representation
7252 -- attributes (Size and Alignment) do not affect representation from
7253 -- the point of view of this test.
7255 if Base_Type (T1) = Base_Type (T2) then
7258 elsif Is_Private_Type (Base_Type (T2))
7259 and then Base_Type (T1) = Full_View (Base_Type (T2))
7264 -- Tagged types never have differing representations
7266 if Is_Tagged_Type (T1) then
7270 -- Representations are definitely different if conventions differ
7272 if Convention (T1) /= Convention (T2) then
7276 -- Representations are different if component alignments differ
7278 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
7280 (Is_Record_Type (T2) or else Is_Array_Type (T2))
7281 and then Component_Alignment (T1) /= Component_Alignment (T2)
7286 -- For arrays, the only real issue is component size. If we know the
7287 -- component size for both arrays, and it is the same, then that's
7288 -- good enough to know we don't have a change of representation.
7290 if Is_Array_Type (T1) then
7291 if Known_Component_Size (T1)
7292 and then Known_Component_Size (T2)
7293 and then Component_Size (T1) = Component_Size (T2)
7299 -- Types definitely have same representation if neither has non-standard
7300 -- representation since default representations are always consistent.
7301 -- If only one has non-standard representation, and the other does not,
7302 -- then we consider that they do not have the same representation. They
7303 -- might, but there is no way of telling early enough.
7305 if Has_Non_Standard_Rep (T1) then
7306 if not Has_Non_Standard_Rep (T2) then
7310 return not Has_Non_Standard_Rep (T2);
7313 -- Here the two types both have non-standard representation, and we need
7314 -- to determine if they have the same non-standard representation.
7316 -- For arrays, we simply need to test if the component sizes are the
7317 -- same. Pragma Pack is reflected in modified component sizes, so this
7318 -- check also deals with pragma Pack.
7320 if Is_Array_Type (T1) then
7321 return Component_Size (T1) = Component_Size (T2);
7323 -- Tagged types always have the same representation, because it is not
7324 -- possible to specify different representations for common fields.
7326 elsif Is_Tagged_Type (T1) then
7329 -- Case of record types
7331 elsif Is_Record_Type (T1) then
7333 -- Packed status must conform
7335 if Is_Packed (T1) /= Is_Packed (T2) then
7338 -- Otherwise we must check components. Typ2 maybe a constrained
7339 -- subtype with fewer components, so we compare the components
7340 -- of the base types.
7343 Record_Case : declare
7344 CD1, CD2 : Entity_Id;
7346 function Same_Rep return Boolean;
7347 -- CD1 and CD2 are either components or discriminants. This
7348 -- function tests whether the two have the same representation
7354 function Same_Rep return Boolean is
7356 if No (Component_Clause (CD1)) then
7357 return No (Component_Clause (CD2));
7361 Present (Component_Clause (CD2))
7363 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
7365 Esize (CD1) = Esize (CD2);
7369 -- Start of processing for Record_Case
7372 if Has_Discriminants (T1) then
7373 CD1 := First_Discriminant (T1);
7374 CD2 := First_Discriminant (T2);
7376 -- The number of discriminants may be different if the
7377 -- derived type has fewer (constrained by values). The
7378 -- invisible discriminants retain the representation of
7379 -- the original, so the discrepancy does not per se
7380 -- indicate a different representation.
7383 and then Present (CD2)
7385 if not Same_Rep then
7388 Next_Discriminant (CD1);
7389 Next_Discriminant (CD2);
7394 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
7395 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
7397 while Present (CD1) loop
7398 if not Same_Rep then
7401 Next_Component (CD1);
7402 Next_Component (CD2);
7410 -- For enumeration types, we must check each literal to see if the
7411 -- representation is the same. Note that we do not permit enumeration
7412 -- representation clauses for Character and Wide_Character, so these
7413 -- cases were already dealt with.
7415 elsif Is_Enumeration_Type (T1) then
7416 Enumeration_Case : declare
7420 L1 := First_Literal (T1);
7421 L2 := First_Literal (T2);
7423 while Present (L1) loop
7424 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
7434 end Enumeration_Case;
7436 -- Any other types have the same representation for these purposes
7441 end Same_Representation;
7447 procedure Set_Biased
7451 Biased : Boolean := True)
7455 Set_Has_Biased_Representation (E);
7457 if Warn_On_Biased_Representation then
7459 ("?" & Msg & " forces biased representation for&", N, E);
7464 --------------------
7465 -- Set_Enum_Esize --
7466 --------------------
7468 procedure Set_Enum_Esize (T : Entity_Id) is
7476 -- Find the minimum standard size (8,16,32,64) that fits
7478 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
7479 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
7482 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
7483 Sz := Standard_Character_Size; -- May be > 8 on some targets
7485 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
7488 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
7491 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
7496 if Hi < Uint_2**08 then
7497 Sz := Standard_Character_Size; -- May be > 8 on some targets
7499 elsif Hi < Uint_2**16 then
7502 elsif Hi < Uint_2**32 then
7505 else pragma Assert (Hi < Uint_2**63);
7510 -- That minimum is the proper size unless we have a foreign convention
7511 -- and the size required is 32 or less, in which case we bump the size
7512 -- up to 32. This is required for C and C++ and seems reasonable for
7513 -- all other foreign conventions.
7515 if Has_Foreign_Convention (T)
7516 and then Esize (T) < Standard_Integer_Size
7518 Init_Esize (T, Standard_Integer_Size);
7524 ------------------------------
7525 -- Validate_Address_Clauses --
7526 ------------------------------
7528 procedure Validate_Address_Clauses is
7530 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
7532 ACCR : Address_Clause_Check_Record
7533 renames Address_Clause_Checks.Table (J);
7544 -- Skip processing of this entry if warning already posted
7546 if not Address_Warning_Posted (ACCR.N) then
7548 Expr := Original_Node (Expression (ACCR.N));
7552 X_Alignment := Alignment (ACCR.X);
7553 Y_Alignment := Alignment (ACCR.Y);
7555 -- Similarly obtain sizes
7557 X_Size := Esize (ACCR.X);
7558 Y_Size := Esize (ACCR.Y);
7560 -- Check for large object overlaying smaller one
7563 and then X_Size > Uint_0
7564 and then X_Size > Y_Size
7567 ("?& overlays smaller object", ACCR.N, ACCR.X);
7569 ("\?program execution may be erroneous", ACCR.N);
7570 Error_Msg_Uint_1 := X_Size;
7572 ("\?size of & is ^", ACCR.N, ACCR.X);
7573 Error_Msg_Uint_1 := Y_Size;
7575 ("\?size of & is ^", ACCR.N, ACCR.Y);
7577 -- Check for inadequate alignment, both of the base object
7578 -- and of the offset, if any.
7580 -- Note: we do not check the alignment if we gave a size
7581 -- warning, since it would likely be redundant.
7583 elsif Y_Alignment /= Uint_0
7584 and then (Y_Alignment < X_Alignment
7587 Nkind (Expr) = N_Attribute_Reference
7589 Attribute_Name (Expr) = Name_Address
7591 Has_Compatible_Alignment
7592 (ACCR.X, Prefix (Expr))
7593 /= Known_Compatible))
7596 ("?specified address for& may be inconsistent "
7600 ("\?program execution may be erroneous (RM 13.3(27))",
7602 Error_Msg_Uint_1 := X_Alignment;
7604 ("\?alignment of & is ^",
7606 Error_Msg_Uint_1 := Y_Alignment;
7608 ("\?alignment of & is ^",
7610 if Y_Alignment >= X_Alignment then
7612 ("\?but offset is not multiple of alignment",
7619 end Validate_Address_Clauses;
7621 ---------------------------
7622 -- Validate_Independence --
7623 ---------------------------
7625 procedure Validate_Independence is
7626 SU : constant Uint := UI_From_Int (System_Storage_Unit);
7634 procedure Check_Array_Type (Atyp : Entity_Id);
7635 -- Checks if the array type Atyp has independent components, and
7636 -- if not, outputs an appropriate set of error messages.
7638 procedure No_Independence;
7639 -- Output message that independence cannot be guaranteed
7641 function OK_Component (C : Entity_Id) return Boolean;
7642 -- Checks one component to see if it is independently accessible, and
7643 -- if so yields True, otherwise yields False if independent access
7644 -- cannot be guaranteed. This is a conservative routine, it only
7645 -- returns True if it knows for sure, it returns False if it knows
7646 -- there is a problem, or it cannot be sure there is no problem.
7648 procedure Reason_Bad_Component (C : Entity_Id);
7649 -- Outputs continuation message if a reason can be determined for
7650 -- the component C being bad.
7652 ----------------------
7653 -- Check_Array_Type --
7654 ----------------------
7656 procedure Check_Array_Type (Atyp : Entity_Id) is
7657 Ctyp : constant Entity_Id := Component_Type (Atyp);
7660 -- OK if no alignment clause, no pack, and no component size
7662 if not Has_Component_Size_Clause (Atyp)
7663 and then not Has_Alignment_Clause (Atyp)
7664 and then not Is_Packed (Atyp)
7669 -- Check actual component size
7671 if not Known_Component_Size (Atyp)
7672 or else not (Addressable (Component_Size (Atyp))
7673 and then Component_Size (Atyp) < 64)
7674 or else Component_Size (Atyp) mod Esize (Ctyp) /= 0
7678 -- Bad component size, check reason
7680 if Has_Component_Size_Clause (Atyp) then
7682 Get_Attribute_Definition_Clause
7683 (Atyp, Attribute_Component_Size);
7686 Error_Msg_Sloc := Sloc (P);
7687 Error_Msg_N ("\because of Component_Size clause#", N);
7692 if Is_Packed (Atyp) then
7693 P := Get_Rep_Pragma (Atyp, Name_Pack);
7696 Error_Msg_Sloc := Sloc (P);
7697 Error_Msg_N ("\because of pragma Pack#", N);
7702 -- No reason found, just return
7707 -- Array type is OK independence-wise
7710 end Check_Array_Type;
7712 ---------------------
7713 -- No_Independence --
7714 ---------------------
7716 procedure No_Independence is
7718 if Pragma_Name (N) = Name_Independent then
7720 ("independence cannot be guaranteed for&", N, E);
7723 ("independent components cannot be guaranteed for&", N, E);
7725 end No_Independence;
7731 function OK_Component (C : Entity_Id) return Boolean is
7732 Rec : constant Entity_Id := Scope (C);
7733 Ctyp : constant Entity_Id := Etype (C);
7736 -- OK if no component clause, no Pack, and no alignment clause
7738 if No (Component_Clause (C))
7739 and then not Is_Packed (Rec)
7740 and then not Has_Alignment_Clause (Rec)
7745 -- Here we look at the actual component layout. A component is
7746 -- addressable if its size is a multiple of the Esize of the
7747 -- component type, and its starting position in the record has
7748 -- appropriate alignment, and the record itself has appropriate
7749 -- alignment to guarantee the component alignment.
7751 -- Make sure sizes are static, always assume the worst for any
7752 -- cases where we cannot check static values.
7754 if not (Known_Static_Esize (C)
7755 and then Known_Static_Esize (Ctyp))
7760 -- Size of component must be addressable or greater than 64 bits
7761 -- and a multiple of bytes.
7763 if not Addressable (Esize (C))
7764 and then Esize (C) < Uint_64
7769 -- Check size is proper multiple
7771 if Esize (C) mod Esize (Ctyp) /= 0 then
7775 -- Check alignment of component is OK
7777 if not Known_Component_Bit_Offset (C)
7778 or else Component_Bit_Offset (C) < Uint_0
7779 or else Component_Bit_Offset (C) mod Esize (Ctyp) /= 0
7784 -- Check alignment of record type is OK
7786 if not Known_Alignment (Rec)
7787 or else (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
7792 -- All tests passed, component is addressable
7797 --------------------------
7798 -- Reason_Bad_Component --
7799 --------------------------
7801 procedure Reason_Bad_Component (C : Entity_Id) is
7802 Rec : constant Entity_Id := Scope (C);
7803 Ctyp : constant Entity_Id := Etype (C);
7806 -- If component clause present assume that's the problem
7808 if Present (Component_Clause (C)) then
7809 Error_Msg_Sloc := Sloc (Component_Clause (C));
7810 Error_Msg_N ("\because of Component_Clause#", N);
7814 -- If pragma Pack clause present, assume that's the problem
7816 if Is_Packed (Rec) then
7817 P := Get_Rep_Pragma (Rec, Name_Pack);
7820 Error_Msg_Sloc := Sloc (P);
7821 Error_Msg_N ("\because of pragma Pack#", N);
7826 -- See if record has bad alignment clause
7828 if Has_Alignment_Clause (Rec)
7829 and then Known_Alignment (Rec)
7830 and then (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
7832 P := Get_Attribute_Definition_Clause (Rec, Attribute_Alignment);
7835 Error_Msg_Sloc := Sloc (P);
7836 Error_Msg_N ("\because of Alignment clause#", N);
7840 -- Couldn't find a reason, so return without a message
7843 end Reason_Bad_Component;
7845 -- Start of processing for Validate_Independence
7848 for J in Independence_Checks.First .. Independence_Checks.Last loop
7849 N := Independence_Checks.Table (J).N;
7850 E := Independence_Checks.Table (J).E;
7851 IC := Pragma_Name (N) = Name_Independent_Components;
7853 -- Deal with component case
7855 if Ekind (E) = E_Discriminant or else Ekind (E) = E_Component then
7856 if not OK_Component (E) then
7858 Reason_Bad_Component (E);
7863 -- Deal with record with Independent_Components
7865 if IC and then Is_Record_Type (E) then
7866 Comp := First_Component_Or_Discriminant (E);
7867 while Present (Comp) loop
7868 if not OK_Component (Comp) then
7870 Reason_Bad_Component (Comp);
7874 Next_Component_Or_Discriminant (Comp);
7878 -- Deal with address clause case
7880 if Is_Object (E) then
7881 Addr := Address_Clause (E);
7883 if Present (Addr) then
7885 Error_Msg_Sloc := Sloc (Addr);
7886 Error_Msg_N ("\because of Address clause#", N);
7891 -- Deal with independent components for array type
7893 if IC and then Is_Array_Type (E) then
7894 Check_Array_Type (E);
7897 -- Deal with independent components for array object
7899 if IC and then Is_Object (E) and then Is_Array_Type (Etype (E)) then
7900 Check_Array_Type (Etype (E));
7905 end Validate_Independence;
7907 -----------------------------------
7908 -- Validate_Unchecked_Conversion --
7909 -----------------------------------
7911 procedure Validate_Unchecked_Conversion
7913 Act_Unit : Entity_Id)
7920 -- Obtain source and target types. Note that we call Ancestor_Subtype
7921 -- here because the processing for generic instantiation always makes
7922 -- subtypes, and we want the original frozen actual types.
7924 -- If we are dealing with private types, then do the check on their
7925 -- fully declared counterparts if the full declarations have been
7926 -- encountered (they don't have to be visible, but they must exist!)
7928 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
7930 if Is_Private_Type (Source)
7931 and then Present (Underlying_Type (Source))
7933 Source := Underlying_Type (Source);
7936 Target := Ancestor_Subtype (Etype (Act_Unit));
7938 -- If either type is generic, the instantiation happens within a generic
7939 -- unit, and there is nothing to check. The proper check
7940 -- will happen when the enclosing generic is instantiated.
7942 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
7946 if Is_Private_Type (Target)
7947 and then Present (Underlying_Type (Target))
7949 Target := Underlying_Type (Target);
7952 -- Source may be unconstrained array, but not target
7954 if Is_Array_Type (Target)
7955 and then not Is_Constrained (Target)
7958 ("unchecked conversion to unconstrained array not allowed", N);
7962 -- Warn if conversion between two different convention pointers
7964 if Is_Access_Type (Target)
7965 and then Is_Access_Type (Source)
7966 and then Convention (Target) /= Convention (Source)
7967 and then Warn_On_Unchecked_Conversion
7969 -- Give warnings for subprogram pointers only on most targets. The
7970 -- exception is VMS, where data pointers can have different lengths
7971 -- depending on the pointer convention.
7973 if Is_Access_Subprogram_Type (Target)
7974 or else Is_Access_Subprogram_Type (Source)
7975 or else OpenVMS_On_Target
7978 ("?conversion between pointers with different conventions!", N);
7982 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
7983 -- warning when compiling GNAT-related sources.
7985 if Warn_On_Unchecked_Conversion
7986 and then not In_Predefined_Unit (N)
7987 and then RTU_Loaded (Ada_Calendar)
7989 (Chars (Source) = Name_Time
7991 Chars (Target) = Name_Time)
7993 -- If Ada.Calendar is loaded and the name of one of the operands is
7994 -- Time, there is a good chance that this is Ada.Calendar.Time.
7997 Calendar_Time : constant Entity_Id :=
7998 Full_View (RTE (RO_CA_Time));
8000 pragma Assert (Present (Calendar_Time));
8002 if Source = Calendar_Time
8003 or else Target = Calendar_Time
8006 ("?representation of 'Time values may change between " &
8007 "'G'N'A'T versions", N);
8012 -- Make entry in unchecked conversion table for later processing by
8013 -- Validate_Unchecked_Conversions, which will check sizes and alignments
8014 -- (using values set by the back-end where possible). This is only done
8015 -- if the appropriate warning is active.
8017 if Warn_On_Unchecked_Conversion then
8018 Unchecked_Conversions.Append
8019 (New_Val => UC_Entry'
8024 -- If both sizes are known statically now, then back end annotation
8025 -- is not required to do a proper check but if either size is not
8026 -- known statically, then we need the annotation.
8028 if Known_Static_RM_Size (Source)
8029 and then Known_Static_RM_Size (Target)
8033 Back_Annotate_Rep_Info := True;
8037 -- If unchecked conversion to access type, and access type is declared
8038 -- in the same unit as the unchecked conversion, then set the
8039 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
8042 if Is_Access_Type (Target) and then
8043 In_Same_Source_Unit (Target, N)
8045 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
8048 -- Generate N_Validate_Unchecked_Conversion node for back end in
8049 -- case the back end needs to perform special validation checks.
8051 -- Shouldn't this be in Exp_Ch13, since the check only gets done
8052 -- if we have full expansion and the back end is called ???
8055 Make_Validate_Unchecked_Conversion (Sloc (N));
8056 Set_Source_Type (Vnode, Source);
8057 Set_Target_Type (Vnode, Target);
8059 -- If the unchecked conversion node is in a list, just insert before it.
8060 -- If not we have some strange case, not worth bothering about.
8062 if Is_List_Member (N) then
8063 Insert_After (N, Vnode);
8065 end Validate_Unchecked_Conversion;
8067 ------------------------------------
8068 -- Validate_Unchecked_Conversions --
8069 ------------------------------------
8071 procedure Validate_Unchecked_Conversions is
8073 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
8075 T : UC_Entry renames Unchecked_Conversions.Table (N);
8077 Eloc : constant Source_Ptr := T.Eloc;
8078 Source : constant Entity_Id := T.Source;
8079 Target : constant Entity_Id := T.Target;
8085 -- This validation check, which warns if we have unequal sizes for
8086 -- unchecked conversion, and thus potentially implementation
8087 -- dependent semantics, is one of the few occasions on which we
8088 -- use the official RM size instead of Esize. See description in
8089 -- Einfo "Handling of Type'Size Values" for details.
8091 if Serious_Errors_Detected = 0
8092 and then Known_Static_RM_Size (Source)
8093 and then Known_Static_RM_Size (Target)
8095 -- Don't do the check if warnings off for either type, note the
8096 -- deliberate use of OR here instead of OR ELSE to get the flag
8097 -- Warnings_Off_Used set for both types if appropriate.
8099 and then not (Has_Warnings_Off (Source)
8101 Has_Warnings_Off (Target))
8103 Source_Siz := RM_Size (Source);
8104 Target_Siz := RM_Size (Target);
8106 if Source_Siz /= Target_Siz then
8108 ("?types for unchecked conversion have different sizes!",
8111 if All_Errors_Mode then
8112 Error_Msg_Name_1 := Chars (Source);
8113 Error_Msg_Uint_1 := Source_Siz;
8114 Error_Msg_Name_2 := Chars (Target);
8115 Error_Msg_Uint_2 := Target_Siz;
8116 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
8118 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
8120 if Is_Discrete_Type (Source)
8121 and then Is_Discrete_Type (Target)
8123 if Source_Siz > Target_Siz then
8125 ("\?^ high order bits of source will be ignored!",
8128 elsif Is_Unsigned_Type (Source) then
8130 ("\?source will be extended with ^ high order " &
8131 "zero bits?!", Eloc);
8135 ("\?source will be extended with ^ high order " &
8140 elsif Source_Siz < Target_Siz then
8141 if Is_Discrete_Type (Target) then
8142 if Bytes_Big_Endian then
8144 ("\?target value will include ^ undefined " &
8149 ("\?target value will include ^ undefined " &
8156 ("\?^ trailing bits of target value will be " &
8157 "undefined!", Eloc);
8160 else pragma Assert (Source_Siz > Target_Siz);
8162 ("\?^ trailing bits of source will be ignored!",
8169 -- If both types are access types, we need to check the alignment.
8170 -- If the alignment of both is specified, we can do it here.
8172 if Serious_Errors_Detected = 0
8173 and then Ekind (Source) in Access_Kind
8174 and then Ekind (Target) in Access_Kind
8175 and then Target_Strict_Alignment
8176 and then Present (Designated_Type (Source))
8177 and then Present (Designated_Type (Target))
8180 D_Source : constant Entity_Id := Designated_Type (Source);
8181 D_Target : constant Entity_Id := Designated_Type (Target);
8184 if Known_Alignment (D_Source)
8185 and then Known_Alignment (D_Target)
8188 Source_Align : constant Uint := Alignment (D_Source);
8189 Target_Align : constant Uint := Alignment (D_Target);
8192 if Source_Align < Target_Align
8193 and then not Is_Tagged_Type (D_Source)
8195 -- Suppress warning if warnings suppressed on either
8196 -- type or either designated type. Note the use of
8197 -- OR here instead of OR ELSE. That is intentional,
8198 -- we would like to set flag Warnings_Off_Used in
8199 -- all types for which warnings are suppressed.
8201 and then not (Has_Warnings_Off (D_Source)
8203 Has_Warnings_Off (D_Target)
8205 Has_Warnings_Off (Source)
8207 Has_Warnings_Off (Target))
8209 Error_Msg_Uint_1 := Target_Align;
8210 Error_Msg_Uint_2 := Source_Align;
8211 Error_Msg_Node_1 := D_Target;
8212 Error_Msg_Node_2 := D_Source;
8214 ("?alignment of & (^) is stricter than " &
8215 "alignment of & (^)!", Eloc);
8217 ("\?resulting access value may have invalid " &
8218 "alignment!", Eloc);
8226 end Validate_Unchecked_Conversions;
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