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;
64 with GNAT.Heap_Sort_G;
66 package body Sem_Ch13 is
68 SSU : constant Pos := System_Storage_Unit;
69 -- Convenient short hand for commonly used constant
71 -----------------------
72 -- Local Subprograms --
73 -----------------------
75 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id);
76 -- This routine is called after setting the Esize of type entity Typ.
77 -- The purpose is to deal with the situation where an alignment has been
78 -- inherited from a derived type that is no longer appropriate for the
79 -- new Esize value. In this case, we reset the Alignment to unknown.
81 procedure Build_Predicate_Function (Typ : Entity_Id; N : Node_Id);
82 -- If Typ has predicates (indicated by Has_Predicates being set for Typ,
83 -- then either there are pragma Invariant entries on the rep chain for the
84 -- type (note that Predicate aspects are converted to pragma Predicate), or
85 -- there are inherited aspects from a parent type, or ancestor subtypes.
86 -- This procedure builds the spec and body for the Predicate function that
87 -- tests these predicates. N is the freeze node for the type. The spec of
88 -- the function is inserted before the freeze node, and the body of the
89 -- function is inserted after the freeze node.
91 procedure Build_Static_Predicate
95 -- Given a predicated type Typ, where Typ is a discrete static subtype,
96 -- whose predicate expression is Expr, tests if Expr is a static predicate,
97 -- and if so, builds the predicate range list. Nam is the name of the one
98 -- argument to the predicate function. Occurrences of the type name in the
99 -- predicate expression have been replaced by identifier references to this
100 -- name, which is unique, so any identifier with Chars matching Nam must be
101 -- a reference to the type. If the predicate is non-static, this procedure
102 -- returns doing nothing. If the predicate is static, then the predicate
103 -- list is stored in Static_Predicate (Typ), and the Expr is rewritten as
104 -- a canonicalized membership operation.
106 function Get_Alignment_Value (Expr : Node_Id) return Uint;
107 -- Given the expression for an alignment value, returns the corresponding
108 -- Uint value. If the value is inappropriate, then error messages are
109 -- posted as required, and a value of No_Uint is returned.
111 function Is_Operational_Item (N : Node_Id) return Boolean;
112 -- A specification for a stream attribute is allowed before the full type
113 -- is declared, as explained in AI-00137 and the corrigendum. Attributes
114 -- that do not specify a representation characteristic are operational
117 procedure New_Stream_Subprogram
121 Nam : TSS_Name_Type);
122 -- Create a subprogram renaming of a given stream attribute to the
123 -- designated subprogram and then in the tagged case, provide this as a
124 -- primitive operation, or in the non-tagged case make an appropriate TSS
125 -- entry. This is more properly an expansion activity than just semantics,
126 -- but the presence of user-defined stream functions for limited types is a
127 -- legality check, which is why this takes place here rather than in
128 -- exp_ch13, where it was previously. Nam indicates the name of the TSS
129 -- function to be generated.
131 -- To avoid elaboration anomalies with freeze nodes, for untagged types
132 -- we generate both a subprogram declaration and a subprogram renaming
133 -- declaration, so that the attribute specification is handled as a
134 -- renaming_as_body. For tagged types, the specification is one of the
138 with procedure Replace_Type_Reference (N : Node_Id);
139 procedure Replace_Type_References_Generic (N : Node_Id; TName : Name_Id);
140 -- This is used to scan an expression for a predicate or invariant aspect
141 -- replacing occurrences of the name TName (the name of the subtype to
142 -- which the aspect applies) with appropriate references to the parameter
143 -- of the predicate function or invariant procedure. The procedure passed
144 -- as a generic parameter does the actual replacement of node N, which is
145 -- either a simple direct reference to TName, or a selected component that
146 -- represents an appropriately qualified occurrence of TName.
152 Biased : Boolean := True);
153 -- If Biased is True, sets Has_Biased_Representation flag for E, and
154 -- outputs a warning message at node N if Warn_On_Biased_Representation is
155 -- is True. This warning inserts the string Msg to describe the construct
158 ----------------------------------------------
159 -- Table for Validate_Unchecked_Conversions --
160 ----------------------------------------------
162 -- The following table collects unchecked conversions for validation.
163 -- Entries are made by Validate_Unchecked_Conversion and then the
164 -- call to Validate_Unchecked_Conversions does the actual error
165 -- checking and posting of warnings. The reason for this delayed
166 -- processing is to take advantage of back-annotations of size and
167 -- alignment values performed by the back end.
169 -- Note: the reason we store a Source_Ptr value instead of a Node_Id
170 -- is that by the time Validate_Unchecked_Conversions is called, Sprint
171 -- will already have modified all Sloc values if the -gnatD option is set.
173 type UC_Entry is record
174 Eloc : Source_Ptr; -- node used for posting warnings
175 Source : Entity_Id; -- source type for unchecked conversion
176 Target : Entity_Id; -- target type for unchecked conversion
179 package Unchecked_Conversions is new Table.Table (
180 Table_Component_Type => UC_Entry,
181 Table_Index_Type => Int,
182 Table_Low_Bound => 1,
184 Table_Increment => 200,
185 Table_Name => "Unchecked_Conversions");
187 ----------------------------------------
188 -- Table for Validate_Address_Clauses --
189 ----------------------------------------
191 -- If an address clause has the form
193 -- for X'Address use Expr
195 -- where Expr is of the form Y'Address or recursively is a reference
196 -- to a constant of either of these forms, and X and Y are entities of
197 -- objects, then if Y has a smaller alignment than X, that merits a
198 -- warning about possible bad alignment. The following table collects
199 -- address clauses of this kind. We put these in a table so that they
200 -- can be checked after the back end has completed annotation of the
201 -- alignments of objects, since we can catch more cases that way.
203 type Address_Clause_Check_Record is record
205 -- The address clause
208 -- The entity of the object overlaying Y
211 -- The entity of the object being overlaid
214 -- Whether the address is offset within Y
217 package Address_Clause_Checks is new Table.Table (
218 Table_Component_Type => Address_Clause_Check_Record,
219 Table_Index_Type => Int,
220 Table_Low_Bound => 1,
222 Table_Increment => 200,
223 Table_Name => "Address_Clause_Checks");
225 -----------------------------------------
226 -- Adjust_Record_For_Reverse_Bit_Order --
227 -----------------------------------------
229 procedure Adjust_Record_For_Reverse_Bit_Order (R : Entity_Id) is
234 -- Processing depends on version of Ada
236 -- For Ada 95, we just renumber bits within a storage unit. We do the
237 -- same for Ada 83 mode, since we recognize pragma Bit_Order in Ada 83,
238 -- and are free to add this extension.
240 if Ada_Version < Ada_2005 then
241 Comp := First_Component_Or_Discriminant (R);
242 while Present (Comp) loop
243 CC := Component_Clause (Comp);
245 -- If component clause is present, then deal with the non-default
246 -- bit order case for Ada 95 mode.
248 -- We only do this processing for the base type, and in fact that
249 -- is important, since otherwise if there are record subtypes, we
250 -- could reverse the bits once for each subtype, which is wrong.
253 and then Ekind (R) = E_Record_Type
256 CFB : constant Uint := Component_Bit_Offset (Comp);
257 CSZ : constant Uint := Esize (Comp);
258 CLC : constant Node_Id := Component_Clause (Comp);
259 Pos : constant Node_Id := Position (CLC);
260 FB : constant Node_Id := First_Bit (CLC);
262 Storage_Unit_Offset : constant Uint :=
263 CFB / System_Storage_Unit;
265 Start_Bit : constant Uint :=
266 CFB mod System_Storage_Unit;
269 -- Cases where field goes over storage unit boundary
271 if Start_Bit + CSZ > System_Storage_Unit then
273 -- Allow multi-byte field but generate warning
275 if Start_Bit mod System_Storage_Unit = 0
276 and then CSZ mod System_Storage_Unit = 0
279 ("multi-byte field specified with non-standard"
280 & " Bit_Order?", CLC);
282 if Bytes_Big_Endian then
284 ("bytes are not reversed "
285 & "(component is big-endian)?", CLC);
288 ("bytes are not reversed "
289 & "(component is little-endian)?", CLC);
292 -- Do not allow non-contiguous field
296 ("attempt to specify non-contiguous field "
297 & "not permitted", CLC);
299 ("\caused by non-standard Bit_Order "
302 ("\consider possibility of using "
303 & "Ada 2005 mode here", CLC);
306 -- Case where field fits in one storage unit
309 -- Give warning if suspicious component clause
311 if Intval (FB) >= System_Storage_Unit
312 and then Warn_On_Reverse_Bit_Order
315 ("?Bit_Order clause does not affect " &
316 "byte ordering", Pos);
318 Intval (Pos) + Intval (FB) /
321 ("?position normalized to ^ before bit " &
322 "order interpreted", Pos);
325 -- Here is where we fix up the Component_Bit_Offset value
326 -- to account for the reverse bit order. Some examples of
327 -- what needs to be done are:
329 -- First_Bit .. Last_Bit Component_Bit_Offset
341 -- The rule is that the first bit is is obtained by
342 -- subtracting the old ending bit from storage_unit - 1.
344 Set_Component_Bit_Offset
346 (Storage_Unit_Offset * System_Storage_Unit) +
347 (System_Storage_Unit - 1) -
348 (Start_Bit + CSZ - 1));
350 Set_Normalized_First_Bit
352 Component_Bit_Offset (Comp) mod
353 System_Storage_Unit);
358 Next_Component_Or_Discriminant (Comp);
361 -- For Ada 2005, we do machine scalar processing, as fully described In
362 -- AI-133. This involves gathering all components which start at the
363 -- same byte offset and processing them together. Same approach is still
364 -- valid in later versions including Ada 2012.
368 Max_Machine_Scalar_Size : constant Uint :=
370 (Standard_Long_Long_Integer_Size);
371 -- We use this as the maximum machine scalar size
374 SSU : constant Uint := UI_From_Int (System_Storage_Unit);
377 -- This first loop through components does two things. First it
378 -- deals with the case of components with component clauses whose
379 -- length is greater than the maximum machine scalar size (either
380 -- accepting them or rejecting as needed). Second, it counts the
381 -- number of components with component clauses whose length does
382 -- not exceed this maximum for later processing.
385 Comp := First_Component_Or_Discriminant (R);
386 while Present (Comp) loop
387 CC := Component_Clause (Comp);
391 Fbit : constant Uint :=
392 Static_Integer (First_Bit (CC));
393 Lbit : constant Uint :=
394 Static_Integer (Last_Bit (CC));
397 -- Case of component with last bit >= max machine scalar
399 if Lbit >= Max_Machine_Scalar_Size then
401 -- This is allowed only if first bit is zero, and
402 -- last bit + 1 is a multiple of storage unit size.
404 if Fbit = 0 and then (Lbit + 1) mod SSU = 0 then
406 -- This is the case to give a warning if enabled
408 if Warn_On_Reverse_Bit_Order then
410 ("multi-byte field specified with "
411 & " non-standard Bit_Order?", CC);
413 if Bytes_Big_Endian then
415 ("\bytes are not reversed "
416 & "(component is big-endian)?", CC);
419 ("\bytes are not reversed "
420 & "(component is little-endian)?", CC);
424 -- Give error message for RM 13.4.1(10) violation
428 ("machine scalar rules not followed for&",
429 First_Bit (CC), Comp);
431 Error_Msg_Uint_1 := Lbit;
432 Error_Msg_Uint_2 := Max_Machine_Scalar_Size;
434 ("\last bit (^) exceeds maximum machine "
438 if (Lbit + 1) mod SSU /= 0 then
439 Error_Msg_Uint_1 := SSU;
441 ("\and is not a multiple of Storage_Unit (^) "
442 & "('R'M 13.4.1(10))",
446 Error_Msg_Uint_1 := Fbit;
448 ("\and first bit (^) is non-zero "
449 & "('R'M 13.4.1(10))",
454 -- OK case of machine scalar related component clause,
455 -- For now, just count them.
458 Num_CC := Num_CC + 1;
463 Next_Component_Or_Discriminant (Comp);
466 -- We need to sort the component clauses on the basis of the
467 -- Position values in the clause, so we can group clauses with
468 -- the same Position. together to determine the relevant machine
472 Comps : array (0 .. Num_CC) of Entity_Id;
473 -- Array to collect component and discriminant entities. The
474 -- data starts at index 1, the 0'th entry is for the sort
477 function CP_Lt (Op1, Op2 : Natural) return Boolean;
478 -- Compare routine for Sort
480 procedure CP_Move (From : Natural; To : Natural);
481 -- Move routine for Sort
483 package Sorting is new GNAT.Heap_Sort_G (CP_Move, CP_Lt);
487 -- Start and stop positions in the component list of the set of
488 -- components with the same starting position (that constitute
489 -- components in a single machine scalar).
492 -- Maximum last bit value of any component in this set
495 -- Corresponding machine scalar size
501 function CP_Lt (Op1, Op2 : Natural) return Boolean is
503 return Position (Component_Clause (Comps (Op1))) <
504 Position (Component_Clause (Comps (Op2)));
511 procedure CP_Move (From : Natural; To : Natural) is
513 Comps (To) := Comps (From);
516 -- Start of processing for Sort_CC
519 -- Collect the machine scalar relevant component clauses
522 Comp := First_Component_Or_Discriminant (R);
523 while Present (Comp) loop
525 CC : constant Node_Id := Component_Clause (Comp);
528 -- Collect only component clauses whose last bit is less
529 -- than machine scalar size. Any component clause whose
530 -- last bit exceeds this value does not take part in
531 -- machine scalar layout considerations. The test for
532 -- Error_Posted makes sure we exclude component clauses
533 -- for which we already posted an error.
536 and then not Error_Posted (Last_Bit (CC))
537 and then Static_Integer (Last_Bit (CC)) <
538 Max_Machine_Scalar_Size
540 Num_CC := Num_CC + 1;
541 Comps (Num_CC) := Comp;
545 Next_Component_Or_Discriminant (Comp);
548 -- Sort by ascending position number
550 Sorting.Sort (Num_CC);
552 -- We now have all the components whose size does not exceed
553 -- the max machine scalar value, sorted by starting position.
554 -- In this loop we gather groups of clauses starting at the
555 -- same position, to process them in accordance with AI-133.
558 while Stop < Num_CC loop
563 (Last_Bit (Component_Clause (Comps (Start))));
564 while Stop < Num_CC loop
566 (Position (Component_Clause (Comps (Stop + 1)))) =
568 (Position (Component_Clause (Comps (Stop))))
576 (Component_Clause (Comps (Stop)))));
582 -- Now we have a group of component clauses from Start to
583 -- Stop whose positions are identical, and MaxL is the
584 -- maximum last bit value of any of these components.
586 -- We need to determine the corresponding machine scalar
587 -- size. This loop assumes that machine scalar sizes are
588 -- even, and that each possible machine scalar has twice
589 -- as many bits as the next smaller one.
591 MSS := Max_Machine_Scalar_Size;
593 and then (MSS / 2) >= SSU
594 and then (MSS / 2) > MaxL
599 -- Here is where we fix up the Component_Bit_Offset value
600 -- to account for the reverse bit order. Some examples of
601 -- what needs to be done for the case of a machine scalar
604 -- First_Bit .. Last_Bit Component_Bit_Offset
616 -- The rule is that the first bit is obtained by subtracting
617 -- the old ending bit from machine scalar size - 1.
619 for C in Start .. Stop loop
621 Comp : constant Entity_Id := Comps (C);
622 CC : constant Node_Id :=
623 Component_Clause (Comp);
624 LB : constant Uint :=
625 Static_Integer (Last_Bit (CC));
626 NFB : constant Uint := MSS - Uint_1 - LB;
627 NLB : constant Uint := NFB + Esize (Comp) - 1;
628 Pos : constant Uint :=
629 Static_Integer (Position (CC));
632 if Warn_On_Reverse_Bit_Order then
633 Error_Msg_Uint_1 := MSS;
635 ("info: reverse bit order in machine " &
636 "scalar of length^?", First_Bit (CC));
637 Error_Msg_Uint_1 := NFB;
638 Error_Msg_Uint_2 := NLB;
640 if Bytes_Big_Endian then
642 ("?\info: big-endian range for "
643 & "component & is ^ .. ^",
644 First_Bit (CC), Comp);
647 ("?\info: little-endian range "
648 & "for component & is ^ .. ^",
649 First_Bit (CC), Comp);
653 Set_Component_Bit_Offset (Comp, Pos * SSU + NFB);
654 Set_Normalized_First_Bit (Comp, NFB mod SSU);
661 end Adjust_Record_For_Reverse_Bit_Order;
663 --------------------------------------
664 -- Alignment_Check_For_Esize_Change --
665 --------------------------------------
667 procedure Alignment_Check_For_Esize_Change (Typ : Entity_Id) is
669 -- If the alignment is known, and not set by a rep clause, and is
670 -- inconsistent with the size being set, then reset it to unknown,
671 -- we assume in this case that the size overrides the inherited
672 -- alignment, and that the alignment must be recomputed.
674 if Known_Alignment (Typ)
675 and then not Has_Alignment_Clause (Typ)
676 and then Esize (Typ) mod (Alignment (Typ) * SSU) /= 0
678 Init_Alignment (Typ);
680 end Alignment_Check_For_Esize_Change;
682 -----------------------------------
683 -- Analyze_Aspect_Specifications --
684 -----------------------------------
686 procedure Analyze_Aspect_Specifications
695 Ins_Node : Node_Id := N;
696 -- Insert pragmas (except Pre/Post/Invariant/Predicate) after this node
698 -- The general processing involves building an attribute definition
699 -- clause or a pragma node that corresponds to the access type. Then
700 -- one of two things happens:
702 -- If we are required to delay the evaluation of this aspect to the
703 -- freeze point, we attach the corresponding pragma/attribute definition
704 -- clause to the aspect specification node, which is then placed in the
705 -- Rep Item chain. In this case we mark the entity by setting the flag
706 -- Has_Delayed_Aspects and we evaluate the rep item at the freeze point.
708 -- If no delay is required, we just insert the pragma or attribute
709 -- after the declaration, and it will get processed by the normal
710 -- circuit. The From_Aspect_Specification flag is set on the pragma
711 -- or attribute definition node in either case to activate special
712 -- processing (e.g. not traversing the list of homonyms for inline).
714 Delay_Required : Boolean;
715 -- Set True if delay is required
718 -- Return if no aspects
724 -- Loop through aspects
727 while Present (Aspect) loop
729 Loc : constant Source_Ptr := Sloc (Aspect);
730 Id : constant Node_Id := Identifier (Aspect);
731 Expr : constant Node_Id := Expression (Aspect);
732 Nam : constant Name_Id := Chars (Id);
733 A_Id : constant Aspect_Id := Get_Aspect_Id (Nam);
736 Eloc : Source_Ptr := Sloc (Expr);
737 -- Source location of expression, modified when we split PPC's
740 -- Skip aspect if already analyzed (not clear if this is needed)
742 if Analyzed (Aspect) then
746 Set_Analyzed (Aspect);
747 Set_Entity (Aspect, E);
748 Ent := New_Occurrence_Of (E, Sloc (Id));
750 -- Check for duplicate aspect. Note that the Comes_From_Source
751 -- test allows duplicate Pre/Post's that we generate internally
752 -- to escape being flagged here.
755 while Anod /= Aspect loop
756 if Nam = Chars (Identifier (Anod))
757 and then Comes_From_Source (Aspect)
759 Error_Msg_Name_1 := Nam;
760 Error_Msg_Sloc := Sloc (Anod);
762 -- Case of same aspect specified twice
764 if Class_Present (Anod) = Class_Present (Aspect) then
765 if not Class_Present (Anod) then
767 ("aspect% for & previously given#",
771 ("aspect `%''Class` for & previously given#",
775 -- Case of Pre and Pre'Class both specified
777 elsif Nam = Name_Pre then
778 if Class_Present (Aspect) then
780 ("aspect `Pre''Class` for & is not allowed here",
783 ("\since aspect `Pre` previously given#",
788 ("aspect `Pre` for & is not allowed here",
791 ("\since aspect `Pre''Class` previously given#",
802 -- Copy expression for later processing by the procedures
803 -- Check_Aspect_At_[Freeze_Point | End_Of_Declarations]
805 Set_Entity (Id, New_Copy_Tree (Expr));
807 -- Processing based on specific aspect
811 -- No_Aspect should be impossible
816 -- Aspects taking an optional boolean argument. For all of
817 -- these we just create a matching pragma and insert it. When
818 -- the aspect is processed to insert the pragma, the expression
819 -- is analyzed, setting Cancel_Aspect if the value is False.
821 when Boolean_Aspects =>
822 Set_Is_Boolean_Aspect (Aspect);
824 -- Build corresponding pragma node
828 Pragma_Argument_Associations => New_List (Ent),
830 Make_Identifier (Sloc (Id), Chars (Id)));
832 -- No delay required if no expression (nothing to delay!)
835 Delay_Required := False;
837 -- Expression is present, delay is required. Note that
838 -- even if the expression is "True", some idiot might
839 -- define True as False before the freeze point!
842 Delay_Required := True;
843 Set_Is_Delayed_Aspect (Aspect);
846 -- Aspects corresponding to attribute definition clauses
848 when Aspect_Address |
851 Aspect_Component_Size |
852 Aspect_External_Tag |
854 Aspect_Machine_Radix |
859 Aspect_Storage_Pool |
860 Aspect_Storage_Size |
865 -- Construct the attribute definition clause
868 Make_Attribute_Definition_Clause (Loc,
871 Expression => Relocate_Node (Expr));
873 -- A delay is required except in the common case where
874 -- the expression is a literal, in which case it is fine
875 -- to take care of it right away.
877 if Nkind_In (Expr, N_Integer_Literal, N_String_Literal) then
878 Delay_Required := False;
880 Delay_Required := True;
881 Set_Is_Delayed_Aspect (Aspect);
884 -- Aspects corresponding to pragmas with two arguments, where
885 -- the first argument is a local name referring to the entity,
886 -- and the second argument is the aspect definition expression.
888 when Aspect_Suppress |
891 -- Construct the pragma
895 Pragma_Argument_Associations => New_List (
896 New_Occurrence_Of (E, Eloc),
897 Relocate_Node (Expr)),
899 Make_Identifier (Sloc (Id), Chars (Id)));
901 -- We don't have to play the delay game here, since the only
902 -- values are check names which don't get analyzed anyway.
904 Delay_Required := False;
906 -- Aspects corresponding to pragmas with two arguments, where
907 -- the second argument is a local name referring to the entity,
908 -- and the first argument is the aspect definition expression.
910 when Aspect_Warnings =>
912 -- Construct the pragma
916 Pragma_Argument_Associations => New_List (
917 Relocate_Node (Expr),
918 New_Occurrence_Of (E, Eloc)),
920 Make_Identifier (Sloc (Id), Chars (Id)),
921 Class_Present => Class_Present (Aspect));
923 -- We don't have to play the delay game here, since the only
924 -- values are ON/OFF which don't get analyzed anyway.
926 Delay_Required := False;
928 -- Aspects Pre/Post generate Precondition/Postcondition pragmas
929 -- with a first argument that is the expression, and a second
930 -- argument that is an informative message if the test fails.
931 -- This is inserted right after the declaration, to get the
932 -- required pragma placement. The processing for the pragmas
933 -- takes care of the required delay.
935 when Aspect_Pre | Aspect_Post => declare
939 if A_Id = Aspect_Pre then
940 Pname := Name_Precondition;
942 Pname := Name_Postcondition;
945 -- If the expressions is of the form A and then B, then
946 -- we generate separate Pre/Post aspects for the separate
947 -- clauses. Since we allow multiple pragmas, there is no
948 -- problem in allowing multiple Pre/Post aspects internally.
950 -- We do not do this for Pre'Class, since we have to put
951 -- these conditions together in a complex OR expression
953 if Pname = Name_Postcondition
954 or else not Class_Present (Aspect)
956 while Nkind (Expr) = N_And_Then loop
957 Insert_After (Aspect,
958 Make_Aspect_Specification (Sloc (Right_Opnd (Expr)),
959 Identifier => Identifier (Aspect),
960 Expression => Relocate_Node (Right_Opnd (Expr)),
961 Class_Present => Class_Present (Aspect),
963 Rewrite (Expr, Relocate_Node (Left_Opnd (Expr)));
968 -- Build the precondition/postcondition pragma
973 Make_Identifier (Sloc (Id), Pname),
974 Class_Present => Class_Present (Aspect),
975 Split_PPC => Split_PPC (Aspect),
976 Pragma_Argument_Associations => New_List (
977 Make_Pragma_Argument_Association (Eloc,
979 Expression => Relocate_Node (Expr))));
981 -- Add message unless exception messages are suppressed
983 if not Opt.Exception_Locations_Suppressed then
984 Append_To (Pragma_Argument_Associations (Aitem),
985 Make_Pragma_Argument_Association (Eloc,
986 Chars => Name_Message,
988 Make_String_Literal (Eloc,
990 & Get_Name_String (Pname)
992 & Build_Location_String (Eloc))));
995 Set_From_Aspect_Specification (Aitem, True);
996 Set_Is_Delayed_Aspect (Aspect);
998 -- For Pre/Post cases, insert immediately after the entity
999 -- declaration, since that is the required pragma placement.
1000 -- Note that for these aspects, we do not have to worry
1001 -- about delay issues, since the pragmas themselves deal
1002 -- with delay of visibility for the expression analysis.
1004 -- If the entity is a library-level subprogram, the pre/
1005 -- postconditions must be treated as late pragmas.
1007 if Nkind (Parent (N)) = N_Compilation_Unit then
1008 Add_Global_Declaration (Aitem);
1010 Insert_After (N, Aitem);
1016 -- Invariant aspects generate a corresponding pragma with a
1017 -- first argument that is the entity, a second argument that is
1018 -- the expression and a third argument that is an appropriate
1019 -- message. This is inserted right after the declaration, to
1020 -- get the required pragma placement. The pragma processing
1021 -- takes care of the required delay.
1023 when Aspect_Invariant =>
1025 -- Construct the pragma
1029 Pragma_Argument_Associations =>
1030 New_List (Ent, Relocate_Node (Expr)),
1031 Class_Present => Class_Present (Aspect),
1032 Pragma_Identifier =>
1033 Make_Identifier (Sloc (Id), Name_Invariant));
1035 -- Add message unless exception messages are suppressed
1037 if not Opt.Exception_Locations_Suppressed then
1038 Append_To (Pragma_Argument_Associations (Aitem),
1039 Make_Pragma_Argument_Association (Eloc,
1040 Chars => Name_Message,
1042 Make_String_Literal (Eloc,
1043 Strval => "failed invariant from "
1044 & Build_Location_String (Eloc))));
1047 Set_From_Aspect_Specification (Aitem, True);
1048 Set_Is_Delayed_Aspect (Aspect);
1050 -- For Invariant case, insert immediately after the entity
1051 -- declaration. We do not have to worry about delay issues
1052 -- since the pragma processing takes care of this.
1054 Insert_After (N, Aitem);
1057 -- Predicate aspects generate a corresponding pragma with a
1058 -- first argument that is the entity, and the second argument
1059 -- is the expression.
1061 when Aspect_Dynamic_Predicate |
1063 Aspect_Static_Predicate =>
1065 -- Construct the pragma (always a pragma Predicate, with
1066 -- flags recording whether
1070 Pragma_Argument_Associations =>
1071 New_List (Ent, Relocate_Node (Expr)),
1072 Class_Present => Class_Present (Aspect),
1073 Pragma_Identifier =>
1074 Make_Identifier (Sloc (Id), Name_Predicate));
1076 Set_From_Aspect_Specification (Aitem, True);
1078 -- Set special flags for dynamic/static cases
1080 if A_Id = Aspect_Dynamic_Predicate then
1081 Set_From_Dynamic_Predicate (Aitem);
1082 elsif A_Id = Aspect_Static_Predicate then
1083 Set_From_Static_Predicate (Aitem);
1086 -- Make sure we have a freeze node (it might otherwise be
1087 -- missing in cases like subtype X is Y, and we would not
1088 -- have a place to build the predicate function).
1090 Set_Has_Predicates (E);
1091 Ensure_Freeze_Node (E);
1092 Set_Is_Delayed_Aspect (Aspect);
1093 Delay_Required := True;
1096 Set_From_Aspect_Specification (Aitem, True);
1098 -- If a delay is required, we delay the freeze (not much point in
1099 -- delaying the aspect if we don't delay the freeze!). The pragma
1100 -- or clause is then attached to the aspect specification which
1101 -- is placed in the rep item list.
1103 if Delay_Required then
1104 Ensure_Freeze_Node (E);
1105 Set_Is_Delayed_Aspect (Aitem);
1106 Set_Has_Delayed_Aspects (E);
1107 Set_Aspect_Rep_Item (Aspect, Aitem);
1108 Record_Rep_Item (E, Aspect);
1110 -- If no delay required, insert the pragma/clause in the tree
1113 -- For Pre/Post cases, insert immediately after the entity
1114 -- declaration, since that is the required pragma placement.
1116 if A_Id = Aspect_Pre or else A_Id = Aspect_Post then
1117 Insert_After (N, Aitem);
1119 -- For all other cases, insert in sequence
1122 Insert_After (Ins_Node, Aitem);
1131 end Analyze_Aspect_Specifications;
1133 -----------------------
1134 -- Analyze_At_Clause --
1135 -----------------------
1137 -- An at clause is replaced by the corresponding Address attribute
1138 -- definition clause that is the preferred approach in Ada 95.
1140 procedure Analyze_At_Clause (N : Node_Id) is
1141 CS : constant Boolean := Comes_From_Source (N);
1144 -- This is an obsolescent feature
1146 Check_Restriction (No_Obsolescent_Features, N);
1148 if Warn_On_Obsolescent_Feature then
1150 ("at clause is an obsolescent feature (RM J.7(2))?", N);
1152 ("\use address attribute definition clause instead?", N);
1155 -- Rewrite as address clause
1158 Make_Attribute_Definition_Clause (Sloc (N),
1159 Name => Identifier (N),
1160 Chars => Name_Address,
1161 Expression => Expression (N)));
1163 -- We preserve Comes_From_Source, since logically the clause still
1164 -- comes from the source program even though it is changed in form.
1166 Set_Comes_From_Source (N, CS);
1168 -- Analyze rewritten clause
1170 Analyze_Attribute_Definition_Clause (N);
1171 end Analyze_At_Clause;
1173 -----------------------------------------
1174 -- Analyze_Attribute_Definition_Clause --
1175 -----------------------------------------
1177 procedure Analyze_Attribute_Definition_Clause (N : Node_Id) is
1178 Loc : constant Source_Ptr := Sloc (N);
1179 Nam : constant Node_Id := Name (N);
1180 Attr : constant Name_Id := Chars (N);
1181 Expr : constant Node_Id := Expression (N);
1182 Id : constant Attribute_Id := Get_Attribute_Id (Attr);
1186 FOnly : Boolean := False;
1187 -- Reset to True for subtype specific attribute (Alignment, Size)
1188 -- and for stream attributes, i.e. those cases where in the call
1189 -- to Rep_Item_Too_Late, FOnly is set True so that only the freezing
1190 -- rules are checked. Note that the case of stream attributes is not
1191 -- clear from the RM, but see AI95-00137. Also, the RM seems to
1192 -- disallow Storage_Size for derived task types, but that is also
1193 -- clearly unintentional.
1195 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type);
1196 -- Common processing for 'Read, 'Write, 'Input and 'Output attribute
1197 -- definition clauses.
1199 function Duplicate_Clause return Boolean;
1200 -- This routine checks if the aspect for U_Ent being given by attribute
1201 -- definition clause N is for an aspect that has already been specified,
1202 -- and if so gives an error message. If there is a duplicate, True is
1203 -- returned, otherwise if there is no error, False is returned.
1205 -----------------------------------
1206 -- Analyze_Stream_TSS_Definition --
1207 -----------------------------------
1209 procedure Analyze_Stream_TSS_Definition (TSS_Nam : TSS_Name_Type) is
1210 Subp : Entity_Id := Empty;
1215 Is_Read : constant Boolean := (TSS_Nam = TSS_Stream_Read);
1217 function Has_Good_Profile (Subp : Entity_Id) return Boolean;
1218 -- Return true if the entity is a subprogram with an appropriate
1219 -- profile for the attribute being defined.
1221 ----------------------
1222 -- Has_Good_Profile --
1223 ----------------------
1225 function Has_Good_Profile (Subp : Entity_Id) return Boolean is
1227 Is_Function : constant Boolean := (TSS_Nam = TSS_Stream_Input);
1228 Expected_Ekind : constant array (Boolean) of Entity_Kind :=
1229 (False => E_Procedure, True => E_Function);
1233 if Ekind (Subp) /= Expected_Ekind (Is_Function) then
1237 F := First_Formal (Subp);
1240 or else Ekind (Etype (F)) /= E_Anonymous_Access_Type
1241 or else Designated_Type (Etype (F)) /=
1242 Class_Wide_Type (RTE (RE_Root_Stream_Type))
1247 if not Is_Function then
1251 Expected_Mode : constant array (Boolean) of Entity_Kind :=
1252 (False => E_In_Parameter,
1253 True => E_Out_Parameter);
1255 if Parameter_Mode (F) /= Expected_Mode (Is_Read) then
1263 Typ := Etype (Subp);
1266 return Base_Type (Typ) = Base_Type (Ent)
1267 and then No (Next_Formal (F));
1268 end Has_Good_Profile;
1270 -- Start of processing for Analyze_Stream_TSS_Definition
1275 if not Is_Type (U_Ent) then
1276 Error_Msg_N ("local name must be a subtype", Nam);
1280 Pnam := TSS (Base_Type (U_Ent), TSS_Nam);
1282 -- If Pnam is present, it can be either inherited from an ancestor
1283 -- type (in which case it is legal to redefine it for this type), or
1284 -- be a previous definition of the attribute for the same type (in
1285 -- which case it is illegal).
1287 -- In the first case, it will have been analyzed already, and we
1288 -- can check that its profile does not match the expected profile
1289 -- for a stream attribute of U_Ent. In the second case, either Pnam
1290 -- has been analyzed (and has the expected profile), or it has not
1291 -- been analyzed yet (case of a type that has not been frozen yet
1292 -- and for which the stream attribute has been set using Set_TSS).
1295 and then (No (First_Entity (Pnam)) or else Has_Good_Profile (Pnam))
1297 Error_Msg_Sloc := Sloc (Pnam);
1298 Error_Msg_Name_1 := Attr;
1299 Error_Msg_N ("% attribute already defined #", Nam);
1305 if Is_Entity_Name (Expr) then
1306 if not Is_Overloaded (Expr) then
1307 if Has_Good_Profile (Entity (Expr)) then
1308 Subp := Entity (Expr);
1312 Get_First_Interp (Expr, I, It);
1313 while Present (It.Nam) loop
1314 if Has_Good_Profile (It.Nam) then
1319 Get_Next_Interp (I, It);
1324 if Present (Subp) then
1325 if Is_Abstract_Subprogram (Subp) then
1326 Error_Msg_N ("stream subprogram must not be abstract", Expr);
1330 Set_Entity (Expr, Subp);
1331 Set_Etype (Expr, Etype (Subp));
1333 New_Stream_Subprogram (N, U_Ent, Subp, TSS_Nam);
1336 Error_Msg_Name_1 := Attr;
1337 Error_Msg_N ("incorrect expression for% attribute", Expr);
1339 end Analyze_Stream_TSS_Definition;
1341 ----------------------
1342 -- Duplicate_Clause --
1343 ----------------------
1345 function Duplicate_Clause return Boolean is
1349 -- Nothing to do if this attribute definition clause comes from
1350 -- an aspect specification, since we could not be duplicating an
1351 -- explicit clause, and we dealt with the case of duplicated aspects
1352 -- in Analyze_Aspect_Specifications.
1354 if From_Aspect_Specification (N) then
1358 -- Otherwise current clause may duplicate previous clause or a
1359 -- previously given aspect specification for the same aspect.
1361 A := Get_Rep_Item_For_Entity (U_Ent, Chars (N));
1364 if Entity (A) = U_Ent then
1365 Error_Msg_Name_1 := Chars (N);
1366 Error_Msg_Sloc := Sloc (A);
1367 Error_Msg_NE ("aspect% for & previously given#", N, U_Ent);
1373 end Duplicate_Clause;
1375 -- Start of processing for Analyze_Attribute_Definition_Clause
1378 -- Process Ignore_Rep_Clauses option
1380 if Ignore_Rep_Clauses then
1383 -- The following should be ignored. They do not affect legality
1384 -- and may be target dependent. The basic idea of -gnatI is to
1385 -- ignore any rep clauses that may be target dependent but do not
1386 -- affect legality (except possibly to be rejected because they
1387 -- are incompatible with the compilation target).
1389 when Attribute_Alignment |
1390 Attribute_Bit_Order |
1391 Attribute_Component_Size |
1392 Attribute_Machine_Radix |
1393 Attribute_Object_Size |
1396 Attribute_Stream_Size |
1397 Attribute_Value_Size =>
1399 Rewrite (N, Make_Null_Statement (Sloc (N)));
1402 -- The following should not be ignored, because in the first place
1403 -- they are reasonably portable, and should not cause problems in
1404 -- compiling code from another target, and also they do affect
1405 -- legality, e.g. failing to provide a stream attribute for a
1406 -- type may make a program illegal.
1408 when Attribute_External_Tag |
1412 Attribute_Storage_Pool |
1413 Attribute_Storage_Size |
1417 -- Other cases are errors ("attribute& cannot be set with
1418 -- definition clause"), which will be caught below.
1426 Ent := Entity (Nam);
1428 if Rep_Item_Too_Early (Ent, N) then
1432 -- Rep clause applies to full view of incomplete type or private type if
1433 -- we have one (if not, this is a premature use of the type). However,
1434 -- certain semantic checks need to be done on the specified entity (i.e.
1435 -- the private view), so we save it in Ent.
1437 if Is_Private_Type (Ent)
1438 and then Is_Derived_Type (Ent)
1439 and then not Is_Tagged_Type (Ent)
1440 and then No (Full_View (Ent))
1442 -- If this is a private type whose completion is a derivation from
1443 -- another private type, there is no full view, and the attribute
1444 -- belongs to the type itself, not its underlying parent.
1448 elsif Ekind (Ent) = E_Incomplete_Type then
1450 -- The attribute applies to the full view, set the entity of the
1451 -- attribute definition accordingly.
1453 Ent := Underlying_Type (Ent);
1455 Set_Entity (Nam, Ent);
1458 U_Ent := Underlying_Type (Ent);
1461 -- Complete other routine error checks
1463 if Etype (Nam) = Any_Type then
1466 elsif Scope (Ent) /= Current_Scope then
1467 Error_Msg_N ("entity must be declared in this scope", Nam);
1470 elsif No (U_Ent) then
1473 elsif Is_Type (U_Ent)
1474 and then not Is_First_Subtype (U_Ent)
1475 and then Id /= Attribute_Object_Size
1476 and then Id /= Attribute_Value_Size
1477 and then not From_At_Mod (N)
1479 Error_Msg_N ("cannot specify attribute for subtype", Nam);
1483 Set_Entity (N, U_Ent);
1485 -- Switch on particular attribute
1493 -- Address attribute definition clause
1495 when Attribute_Address => Address : begin
1497 -- A little error check, catch for X'Address use X'Address;
1499 if Nkind (Nam) = N_Identifier
1500 and then Nkind (Expr) = N_Attribute_Reference
1501 and then Attribute_Name (Expr) = Name_Address
1502 and then Nkind (Prefix (Expr)) = N_Identifier
1503 and then Chars (Nam) = Chars (Prefix (Expr))
1506 ("address for & is self-referencing", Prefix (Expr), Ent);
1510 -- Not that special case, carry on with analysis of expression
1512 Analyze_And_Resolve (Expr, RTE (RE_Address));
1514 -- Even when ignoring rep clauses we need to indicate that the
1515 -- entity has an address clause and thus it is legal to declare
1518 if Ignore_Rep_Clauses then
1519 if Ekind_In (U_Ent, E_Variable, E_Constant) then
1520 Record_Rep_Item (U_Ent, N);
1526 if Duplicate_Clause then
1529 -- Case of address clause for subprogram
1531 elsif Is_Subprogram (U_Ent) then
1532 if Has_Homonym (U_Ent) then
1534 ("address clause cannot be given " &
1535 "for overloaded subprogram",
1540 -- For subprograms, all address clauses are permitted, and we
1541 -- mark the subprogram as having a deferred freeze so that Gigi
1542 -- will not elaborate it too soon.
1544 -- Above needs more comments, what is too soon about???
1546 Set_Has_Delayed_Freeze (U_Ent);
1548 -- Case of address clause for entry
1550 elsif Ekind (U_Ent) = E_Entry then
1551 if Nkind (Parent (N)) = N_Task_Body then
1553 ("entry address must be specified in task spec", Nam);
1557 -- For entries, we require a constant address
1559 Check_Constant_Address_Clause (Expr, U_Ent);
1561 -- Special checks for task types
1563 if Is_Task_Type (Scope (U_Ent))
1564 and then Comes_From_Source (Scope (U_Ent))
1567 ("?entry address declared for entry in task type", N);
1569 ("\?only one task can be declared of this type", N);
1572 -- Entry address clauses are obsolescent
1574 Check_Restriction (No_Obsolescent_Features, N);
1576 if Warn_On_Obsolescent_Feature then
1578 ("attaching interrupt to task entry is an " &
1579 "obsolescent feature (RM J.7.1)?", N);
1581 ("\use interrupt procedure instead?", N);
1584 -- Case of an address clause for a controlled object which we
1585 -- consider to be erroneous.
1587 elsif Is_Controlled (Etype (U_Ent))
1588 or else Has_Controlled_Component (Etype (U_Ent))
1591 ("?controlled object& must not be overlaid", Nam, U_Ent);
1593 ("\?Program_Error will be raised at run time", Nam);
1594 Insert_Action (Declaration_Node (U_Ent),
1595 Make_Raise_Program_Error (Loc,
1596 Reason => PE_Overlaid_Controlled_Object));
1599 -- Case of address clause for a (non-controlled) object
1602 Ekind (U_Ent) = E_Variable
1604 Ekind (U_Ent) = E_Constant
1607 Expr : constant Node_Id := Expression (N);
1612 -- Exported variables cannot have an address clause, because
1613 -- this cancels the effect of the pragma Export.
1615 if Is_Exported (U_Ent) then
1617 ("cannot export object with address clause", Nam);
1621 Find_Overlaid_Entity (N, O_Ent, Off);
1623 -- Overlaying controlled objects is erroneous
1626 and then (Has_Controlled_Component (Etype (O_Ent))
1627 or else Is_Controlled (Etype (O_Ent)))
1630 ("?cannot overlay with controlled object", Expr);
1632 ("\?Program_Error will be raised at run time", Expr);
1633 Insert_Action (Declaration_Node (U_Ent),
1634 Make_Raise_Program_Error (Loc,
1635 Reason => PE_Overlaid_Controlled_Object));
1638 elsif Present (O_Ent)
1639 and then Ekind (U_Ent) = E_Constant
1640 and then not Is_Constant_Object (O_Ent)
1642 Error_Msg_N ("constant overlays a variable?", Expr);
1644 elsif Present (Renamed_Object (U_Ent)) then
1646 ("address clause not allowed"
1647 & " for a renaming declaration (RM 13.1(6))", Nam);
1650 -- Imported variables can have an address clause, but then
1651 -- the import is pretty meaningless except to suppress
1652 -- initializations, so we do not need such variables to
1653 -- be statically allocated (and in fact it causes trouble
1654 -- if the address clause is a local value).
1656 elsif Is_Imported (U_Ent) then
1657 Set_Is_Statically_Allocated (U_Ent, False);
1660 -- We mark a possible modification of a variable with an
1661 -- address clause, since it is likely aliasing is occurring.
1663 Note_Possible_Modification (Nam, Sure => False);
1665 -- Here we are checking for explicit overlap of one variable
1666 -- by another, and if we find this then mark the overlapped
1667 -- variable as also being volatile to prevent unwanted
1668 -- optimizations. This is a significant pessimization so
1669 -- avoid it when there is an offset, i.e. when the object
1670 -- is composite; they cannot be optimized easily anyway.
1673 and then Is_Object (O_Ent)
1676 Set_Treat_As_Volatile (O_Ent);
1679 -- Legality checks on the address clause for initialized
1680 -- objects is deferred until the freeze point, because
1681 -- a subsequent pragma might indicate that the object is
1682 -- imported and thus not initialized.
1684 Set_Has_Delayed_Freeze (U_Ent);
1686 -- If an initialization call has been generated for this
1687 -- object, it needs to be deferred to after the freeze node
1688 -- we have just now added, otherwise GIGI will see a
1689 -- reference to the variable (as actual to the IP call)
1690 -- before its definition.
1693 Init_Call : constant Node_Id := Find_Init_Call (U_Ent, N);
1695 if Present (Init_Call) then
1697 Append_Freeze_Action (U_Ent, Init_Call);
1701 if Is_Exported (U_Ent) then
1703 ("& cannot be exported if an address clause is given",
1706 ("\define and export a variable " &
1707 "that holds its address instead",
1711 -- Entity has delayed freeze, so we will generate an
1712 -- alignment check at the freeze point unless suppressed.
1714 if not Range_Checks_Suppressed (U_Ent)
1715 and then not Alignment_Checks_Suppressed (U_Ent)
1717 Set_Check_Address_Alignment (N);
1720 -- Kill the size check code, since we are not allocating
1721 -- the variable, it is somewhere else.
1723 Kill_Size_Check_Code (U_Ent);
1725 -- If the address clause is of the form:
1727 -- for Y'Address use X'Address
1731 -- Const : constant Address := X'Address;
1733 -- for Y'Address use Const;
1735 -- then we make an entry in the table for checking the size
1736 -- and alignment of the overlaying variable. We defer this
1737 -- check till after code generation to take full advantage
1738 -- of the annotation done by the back end. This entry is
1739 -- only made if the address clause comes from source.
1740 -- If the entity has a generic type, the check will be
1741 -- performed in the instance if the actual type justifies
1742 -- it, and we do not insert the clause in the table to
1743 -- prevent spurious warnings.
1745 if Address_Clause_Overlay_Warnings
1746 and then Comes_From_Source (N)
1747 and then Present (O_Ent)
1748 and then Is_Object (O_Ent)
1750 if not Is_Generic_Type (Etype (U_Ent)) then
1751 Address_Clause_Checks.Append ((N, U_Ent, O_Ent, Off));
1754 -- If variable overlays a constant view, and we are
1755 -- warning on overlays, then mark the variable as
1756 -- overlaying a constant (we will give warnings later
1757 -- if this variable is assigned).
1759 if Is_Constant_Object (O_Ent)
1760 and then Ekind (U_Ent) = E_Variable
1762 Set_Overlays_Constant (U_Ent);
1767 -- Not a valid entity for an address clause
1770 Error_Msg_N ("address cannot be given for &", Nam);
1778 -- Alignment attribute definition clause
1780 when Attribute_Alignment => Alignment : declare
1781 Align : constant Uint := Get_Alignment_Value (Expr);
1786 if not Is_Type (U_Ent)
1787 and then Ekind (U_Ent) /= E_Variable
1788 and then Ekind (U_Ent) /= E_Constant
1790 Error_Msg_N ("alignment cannot be given for &", Nam);
1792 elsif Duplicate_Clause then
1795 elsif Align /= No_Uint then
1796 Set_Has_Alignment_Clause (U_Ent);
1797 Set_Alignment (U_Ent, Align);
1799 -- For an array type, U_Ent is the first subtype. In that case,
1800 -- also set the alignment of the anonymous base type so that
1801 -- other subtypes (such as the itypes for aggregates of the
1802 -- type) also receive the expected alignment.
1804 if Is_Array_Type (U_Ent) then
1805 Set_Alignment (Base_Type (U_Ent), Align);
1814 -- Bit_Order attribute definition clause
1816 when Attribute_Bit_Order => Bit_Order : declare
1818 if not Is_Record_Type (U_Ent) then
1820 ("Bit_Order can only be defined for record type", Nam);
1822 elsif Duplicate_Clause then
1826 Analyze_And_Resolve (Expr, RTE (RE_Bit_Order));
1828 if Etype (Expr) = Any_Type then
1831 elsif not Is_Static_Expression (Expr) then
1832 Flag_Non_Static_Expr
1833 ("Bit_Order requires static expression!", Expr);
1836 if (Expr_Value (Expr) = 0) /= Bytes_Big_Endian then
1837 Set_Reverse_Bit_Order (U_Ent, True);
1843 --------------------
1844 -- Component_Size --
1845 --------------------
1847 -- Component_Size attribute definition clause
1849 when Attribute_Component_Size => Component_Size_Case : declare
1850 Csize : constant Uint := Static_Integer (Expr);
1854 New_Ctyp : Entity_Id;
1858 if not Is_Array_Type (U_Ent) then
1859 Error_Msg_N ("component size requires array type", Nam);
1863 Btype := Base_Type (U_Ent);
1864 Ctyp := Component_Type (Btype);
1866 if Duplicate_Clause then
1869 elsif Rep_Item_Too_Early (Btype, N) then
1872 elsif Csize /= No_Uint then
1873 Check_Size (Expr, Ctyp, Csize, Biased);
1875 -- For the biased case, build a declaration for a subtype that
1876 -- will be used to represent the biased subtype that reflects
1877 -- the biased representation of components. We need the subtype
1878 -- to get proper conversions on referencing elements of the
1879 -- array. Note: component size clauses are ignored in VM mode.
1881 if VM_Target = No_VM then
1884 Make_Defining_Identifier (Loc,
1886 New_External_Name (Chars (U_Ent), 'C', 0, 'T'));
1889 Make_Subtype_Declaration (Loc,
1890 Defining_Identifier => New_Ctyp,
1891 Subtype_Indication =>
1892 New_Occurrence_Of (Component_Type (Btype), Loc));
1894 Set_Parent (Decl, N);
1895 Analyze (Decl, Suppress => All_Checks);
1897 Set_Has_Delayed_Freeze (New_Ctyp, False);
1898 Set_Esize (New_Ctyp, Csize);
1899 Set_RM_Size (New_Ctyp, Csize);
1900 Init_Alignment (New_Ctyp);
1901 Set_Is_Itype (New_Ctyp, True);
1902 Set_Associated_Node_For_Itype (New_Ctyp, U_Ent);
1904 Set_Component_Type (Btype, New_Ctyp);
1905 Set_Biased (New_Ctyp, N, "component size clause");
1908 Set_Component_Size (Btype, Csize);
1910 -- For VM case, we ignore component size clauses
1913 -- Give a warning unless we are in GNAT mode, in which case
1914 -- the warning is suppressed since it is not useful.
1916 if not GNAT_Mode then
1918 ("?component size ignored in this configuration", N);
1922 -- Deal with warning on overridden size
1924 if Warn_On_Overridden_Size
1925 and then Has_Size_Clause (Ctyp)
1926 and then RM_Size (Ctyp) /= Csize
1929 ("?component size overrides size clause for&",
1933 Set_Has_Component_Size_Clause (Btype, True);
1934 Set_Has_Non_Standard_Rep (Btype, True);
1936 end Component_Size_Case;
1942 when Attribute_External_Tag => External_Tag :
1944 if not Is_Tagged_Type (U_Ent) then
1945 Error_Msg_N ("should be a tagged type", Nam);
1948 if Duplicate_Clause then
1952 Analyze_And_Resolve (Expr, Standard_String);
1954 if not Is_Static_Expression (Expr) then
1955 Flag_Non_Static_Expr
1956 ("static string required for tag name!", Nam);
1959 if VM_Target = No_VM then
1960 Set_Has_External_Tag_Rep_Clause (U_Ent);
1962 Error_Msg_Name_1 := Attr;
1964 ("% attribute unsupported in this configuration", Nam);
1967 if not Is_Library_Level_Entity (U_Ent) then
1969 ("?non-unique external tag supplied for &", N, U_Ent);
1971 ("?\same external tag applies to all subprogram calls", N);
1973 ("?\corresponding internal tag cannot be obtained", N);
1982 when Attribute_Input =>
1983 Analyze_Stream_TSS_Definition (TSS_Stream_Input);
1984 Set_Has_Specified_Stream_Input (Ent);
1990 -- Machine radix attribute definition clause
1992 when Attribute_Machine_Radix => Machine_Radix : declare
1993 Radix : constant Uint := Static_Integer (Expr);
1996 if not Is_Decimal_Fixed_Point_Type (U_Ent) then
1997 Error_Msg_N ("decimal fixed-point type expected for &", Nam);
1999 elsif Duplicate_Clause then
2002 elsif Radix /= No_Uint then
2003 Set_Has_Machine_Radix_Clause (U_Ent);
2004 Set_Has_Non_Standard_Rep (Base_Type (U_Ent));
2008 elsif Radix = 10 then
2009 Set_Machine_Radix_10 (U_Ent);
2011 Error_Msg_N ("machine radix value must be 2 or 10", Expr);
2020 -- Object_Size attribute definition clause
2022 when Attribute_Object_Size => Object_Size : declare
2023 Size : constant Uint := Static_Integer (Expr);
2026 pragma Warnings (Off, Biased);
2029 if not Is_Type (U_Ent) then
2030 Error_Msg_N ("Object_Size cannot be given for &", Nam);
2032 elsif Duplicate_Clause then
2036 Check_Size (Expr, U_Ent, Size, Biased);
2044 UI_Mod (Size, 64) /= 0
2047 ("Object_Size must be 8, 16, 32, or multiple of 64",
2051 Set_Esize (U_Ent, Size);
2052 Set_Has_Object_Size_Clause (U_Ent);
2053 Alignment_Check_For_Esize_Change (U_Ent);
2061 when Attribute_Output =>
2062 Analyze_Stream_TSS_Definition (TSS_Stream_Output);
2063 Set_Has_Specified_Stream_Output (Ent);
2069 when Attribute_Read =>
2070 Analyze_Stream_TSS_Definition (TSS_Stream_Read);
2071 Set_Has_Specified_Stream_Read (Ent);
2077 -- Size attribute definition clause
2079 when Attribute_Size => Size : declare
2080 Size : constant Uint := Static_Integer (Expr);
2087 if Duplicate_Clause then
2090 elsif not Is_Type (U_Ent)
2091 and then Ekind (U_Ent) /= E_Variable
2092 and then Ekind (U_Ent) /= E_Constant
2094 Error_Msg_N ("size cannot be given for &", Nam);
2096 elsif Is_Array_Type (U_Ent)
2097 and then not Is_Constrained (U_Ent)
2100 ("size cannot be given for unconstrained array", Nam);
2102 elsif Size /= No_Uint then
2104 if VM_Target /= No_VM and then not GNAT_Mode then
2106 -- Size clause is not handled properly on VM targets.
2107 -- Display a warning unless we are in GNAT mode, in which
2108 -- case this is useless.
2111 ("?size clauses are ignored in this configuration", N);
2114 if Is_Type (U_Ent) then
2117 Etyp := Etype (U_Ent);
2120 -- Check size, note that Gigi is in charge of checking that the
2121 -- size of an array or record type is OK. Also we do not check
2122 -- the size in the ordinary fixed-point case, since it is too
2123 -- early to do so (there may be subsequent small clause that
2124 -- affects the size). We can check the size if a small clause
2125 -- has already been given.
2127 if not Is_Ordinary_Fixed_Point_Type (U_Ent)
2128 or else Has_Small_Clause (U_Ent)
2130 Check_Size (Expr, Etyp, Size, Biased);
2131 Set_Biased (U_Ent, N, "size clause", Biased);
2134 -- For types set RM_Size and Esize if possible
2136 if Is_Type (U_Ent) then
2137 Set_RM_Size (U_Ent, Size);
2139 -- For scalar types, increase Object_Size to power of 2, but
2140 -- not less than a storage unit in any case (i.e., normally
2141 -- this means it will be byte addressable).
2143 if Is_Scalar_Type (U_Ent) then
2144 if Size <= System_Storage_Unit then
2145 Init_Esize (U_Ent, System_Storage_Unit);
2146 elsif Size <= 16 then
2147 Init_Esize (U_Ent, 16);
2148 elsif Size <= 32 then
2149 Init_Esize (U_Ent, 32);
2151 Set_Esize (U_Ent, (Size + 63) / 64 * 64);
2154 -- For all other types, object size = value size. The
2155 -- backend will adjust as needed.
2158 Set_Esize (U_Ent, Size);
2161 Alignment_Check_For_Esize_Change (U_Ent);
2163 -- For objects, set Esize only
2166 if Is_Elementary_Type (Etyp) then
2167 if Size /= System_Storage_Unit
2169 Size /= System_Storage_Unit * 2
2171 Size /= System_Storage_Unit * 4
2173 Size /= System_Storage_Unit * 8
2175 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
2176 Error_Msg_Uint_2 := Error_Msg_Uint_1 * 8;
2178 ("size for primitive object must be a power of 2"
2179 & " in the range ^-^", N);
2183 Set_Esize (U_Ent, Size);
2186 Set_Has_Size_Clause (U_Ent);
2194 -- Small attribute definition clause
2196 when Attribute_Small => Small : declare
2197 Implicit_Base : constant Entity_Id := Base_Type (U_Ent);
2201 Analyze_And_Resolve (Expr, Any_Real);
2203 if Etype (Expr) = Any_Type then
2206 elsif not Is_Static_Expression (Expr) then
2207 Flag_Non_Static_Expr
2208 ("small requires static expression!", Expr);
2212 Small := Expr_Value_R (Expr);
2214 if Small <= Ureal_0 then
2215 Error_Msg_N ("small value must be greater than zero", Expr);
2221 if not Is_Ordinary_Fixed_Point_Type (U_Ent) then
2223 ("small requires an ordinary fixed point type", Nam);
2225 elsif Has_Small_Clause (U_Ent) then
2226 Error_Msg_N ("small already given for &", Nam);
2228 elsif Small > Delta_Value (U_Ent) then
2230 ("small value must not be greater then delta value", Nam);
2233 Set_Small_Value (U_Ent, Small);
2234 Set_Small_Value (Implicit_Base, Small);
2235 Set_Has_Small_Clause (U_Ent);
2236 Set_Has_Small_Clause (Implicit_Base);
2237 Set_Has_Non_Standard_Rep (Implicit_Base);
2245 -- Storage_Pool attribute definition clause
2247 when Attribute_Storage_Pool => Storage_Pool : declare
2252 if Ekind (U_Ent) = E_Access_Subprogram_Type then
2254 ("storage pool cannot be given for access-to-subprogram type",
2259 Ekind_In (U_Ent, E_Access_Type, E_General_Access_Type)
2262 ("storage pool can only be given for access types", Nam);
2265 elsif Is_Derived_Type (U_Ent) then
2267 ("storage pool cannot be given for a derived access type",
2270 elsif Duplicate_Clause then
2273 elsif Present (Associated_Storage_Pool (U_Ent)) then
2274 Error_Msg_N ("storage pool already given for &", Nam);
2279 (Expr, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
2281 if not Denotes_Variable (Expr) then
2282 Error_Msg_N ("storage pool must be a variable", Expr);
2286 if Nkind (Expr) = N_Type_Conversion then
2287 T := Etype (Expression (Expr));
2292 -- The Stack_Bounded_Pool is used internally for implementing
2293 -- access types with a Storage_Size. Since it only work
2294 -- properly when used on one specific type, we need to check
2295 -- that it is not hijacked improperly:
2296 -- type T is access Integer;
2297 -- for T'Storage_Size use n;
2298 -- type Q is access Float;
2299 -- for Q'Storage_Size use T'Storage_Size; -- incorrect
2301 if RTE_Available (RE_Stack_Bounded_Pool)
2302 and then Base_Type (T) = RTE (RE_Stack_Bounded_Pool)
2304 Error_Msg_N ("non-shareable internal Pool", Expr);
2308 -- If the argument is a name that is not an entity name, then
2309 -- we construct a renaming operation to define an entity of
2310 -- type storage pool.
2312 if not Is_Entity_Name (Expr)
2313 and then Is_Object_Reference (Expr)
2315 Pool := Make_Temporary (Loc, 'P', Expr);
2318 Rnode : constant Node_Id :=
2319 Make_Object_Renaming_Declaration (Loc,
2320 Defining_Identifier => Pool,
2322 New_Occurrence_Of (Etype (Expr), Loc),
2326 Insert_Before (N, Rnode);
2328 Set_Associated_Storage_Pool (U_Ent, Pool);
2331 elsif Is_Entity_Name (Expr) then
2332 Pool := Entity (Expr);
2334 -- If pool is a renamed object, get original one. This can
2335 -- happen with an explicit renaming, and within instances.
2337 while Present (Renamed_Object (Pool))
2338 and then Is_Entity_Name (Renamed_Object (Pool))
2340 Pool := Entity (Renamed_Object (Pool));
2343 if Present (Renamed_Object (Pool))
2344 and then Nkind (Renamed_Object (Pool)) = N_Type_Conversion
2345 and then Is_Entity_Name (Expression (Renamed_Object (Pool)))
2347 Pool := Entity (Expression (Renamed_Object (Pool)));
2350 Set_Associated_Storage_Pool (U_Ent, Pool);
2352 elsif Nkind (Expr) = N_Type_Conversion
2353 and then Is_Entity_Name (Expression (Expr))
2354 and then Nkind (Original_Node (Expr)) = N_Attribute_Reference
2356 Pool := Entity (Expression (Expr));
2357 Set_Associated_Storage_Pool (U_Ent, Pool);
2360 Error_Msg_N ("incorrect reference to a Storage Pool", Expr);
2369 -- Storage_Size attribute definition clause
2371 when Attribute_Storage_Size => Storage_Size : declare
2372 Btype : constant Entity_Id := Base_Type (U_Ent);
2376 if Is_Task_Type (U_Ent) then
2377 Check_Restriction (No_Obsolescent_Features, N);
2379 if Warn_On_Obsolescent_Feature then
2381 ("storage size clause for task is an " &
2382 "obsolescent feature (RM J.9)?", N);
2383 Error_Msg_N ("\use Storage_Size pragma instead?", N);
2389 if not Is_Access_Type (U_Ent)
2390 and then Ekind (U_Ent) /= E_Task_Type
2392 Error_Msg_N ("storage size cannot be given for &", Nam);
2394 elsif Is_Access_Type (U_Ent) and Is_Derived_Type (U_Ent) then
2396 ("storage size cannot be given for a derived access type",
2399 elsif Duplicate_Clause then
2403 Analyze_And_Resolve (Expr, Any_Integer);
2405 if Is_Access_Type (U_Ent) then
2406 if Present (Associated_Storage_Pool (U_Ent)) then
2407 Error_Msg_N ("storage pool already given for &", Nam);
2411 if Is_OK_Static_Expression (Expr)
2412 and then Expr_Value (Expr) = 0
2414 Set_No_Pool_Assigned (Btype);
2417 else -- Is_Task_Type (U_Ent)
2418 Sprag := Get_Rep_Pragma (Btype, Name_Storage_Size);
2420 if Present (Sprag) then
2421 Error_Msg_Sloc := Sloc (Sprag);
2423 ("Storage_Size already specified#", Nam);
2428 Set_Has_Storage_Size_Clause (Btype);
2436 when Attribute_Stream_Size => Stream_Size : declare
2437 Size : constant Uint := Static_Integer (Expr);
2440 if Ada_Version <= Ada_95 then
2441 Check_Restriction (No_Implementation_Attributes, N);
2444 if Duplicate_Clause then
2447 elsif Is_Elementary_Type (U_Ent) then
2448 if Size /= System_Storage_Unit
2450 Size /= System_Storage_Unit * 2
2452 Size /= System_Storage_Unit * 4
2454 Size /= System_Storage_Unit * 8
2456 Error_Msg_Uint_1 := UI_From_Int (System_Storage_Unit);
2458 ("stream size for elementary type must be a"
2459 & " power of 2 and at least ^", N);
2461 elsif RM_Size (U_Ent) > Size then
2462 Error_Msg_Uint_1 := RM_Size (U_Ent);
2464 ("stream size for elementary type must be a"
2465 & " power of 2 and at least ^", N);
2468 Set_Has_Stream_Size_Clause (U_Ent);
2471 Error_Msg_N ("Stream_Size cannot be given for &", Nam);
2479 -- Value_Size attribute definition clause
2481 when Attribute_Value_Size => Value_Size : declare
2482 Size : constant Uint := Static_Integer (Expr);
2486 if not Is_Type (U_Ent) then
2487 Error_Msg_N ("Value_Size cannot be given for &", Nam);
2489 elsif Duplicate_Clause then
2492 elsif Is_Array_Type (U_Ent)
2493 and then not Is_Constrained (U_Ent)
2496 ("Value_Size cannot be given for unconstrained array", Nam);
2499 if Is_Elementary_Type (U_Ent) then
2500 Check_Size (Expr, U_Ent, Size, Biased);
2501 Set_Biased (U_Ent, N, "value size clause", Biased);
2504 Set_RM_Size (U_Ent, Size);
2512 when Attribute_Write =>
2513 Analyze_Stream_TSS_Definition (TSS_Stream_Write);
2514 Set_Has_Specified_Stream_Write (Ent);
2516 -- All other attributes cannot be set
2520 ("attribute& cannot be set with definition clause", N);
2523 -- The test for the type being frozen must be performed after
2524 -- any expression the clause has been analyzed since the expression
2525 -- itself might cause freezing that makes the clause illegal.
2527 if Rep_Item_Too_Late (U_Ent, N, FOnly) then
2530 end Analyze_Attribute_Definition_Clause;
2532 ----------------------------
2533 -- Analyze_Code_Statement --
2534 ----------------------------
2536 procedure Analyze_Code_Statement (N : Node_Id) is
2537 HSS : constant Node_Id := Parent (N);
2538 SBody : constant Node_Id := Parent (HSS);
2539 Subp : constant Entity_Id := Current_Scope;
2546 -- Analyze and check we get right type, note that this implements the
2547 -- requirement (RM 13.8(1)) that Machine_Code be with'ed, since that
2548 -- is the only way that Asm_Insn could possibly be visible.
2550 Analyze_And_Resolve (Expression (N));
2552 if Etype (Expression (N)) = Any_Type then
2554 elsif Etype (Expression (N)) /= RTE (RE_Asm_Insn) then
2555 Error_Msg_N ("incorrect type for code statement", N);
2559 Check_Code_Statement (N);
2561 -- Make sure we appear in the handled statement sequence of a
2562 -- subprogram (RM 13.8(3)).
2564 if Nkind (HSS) /= N_Handled_Sequence_Of_Statements
2565 or else Nkind (SBody) /= N_Subprogram_Body
2568 ("code statement can only appear in body of subprogram", N);
2572 -- Do remaining checks (RM 13.8(3)) if not already done
2574 if not Is_Machine_Code_Subprogram (Subp) then
2575 Set_Is_Machine_Code_Subprogram (Subp);
2577 -- No exception handlers allowed
2579 if Present (Exception_Handlers (HSS)) then
2581 ("exception handlers not permitted in machine code subprogram",
2582 First (Exception_Handlers (HSS)));
2585 -- No declarations other than use clauses and pragmas (we allow
2586 -- certain internally generated declarations as well).
2588 Decl := First (Declarations (SBody));
2589 while Present (Decl) loop
2590 DeclO := Original_Node (Decl);
2591 if Comes_From_Source (DeclO)
2592 and not Nkind_In (DeclO, N_Pragma,
2593 N_Use_Package_Clause,
2595 N_Implicit_Label_Declaration)
2598 ("this declaration not allowed in machine code subprogram",
2605 -- No statements other than code statements, pragmas, and labels.
2606 -- Again we allow certain internally generated statements.
2608 Stmt := First (Statements (HSS));
2609 while Present (Stmt) loop
2610 StmtO := Original_Node (Stmt);
2611 if Comes_From_Source (StmtO)
2612 and then not Nkind_In (StmtO, N_Pragma,
2617 ("this statement is not allowed in machine code subprogram",
2624 end Analyze_Code_Statement;
2626 -----------------------------------------------
2627 -- Analyze_Enumeration_Representation_Clause --
2628 -----------------------------------------------
2630 procedure Analyze_Enumeration_Representation_Clause (N : Node_Id) is
2631 Ident : constant Node_Id := Identifier (N);
2632 Aggr : constant Node_Id := Array_Aggregate (N);
2633 Enumtype : Entity_Id;
2639 Err : Boolean := False;
2641 Lo : constant Uint := Expr_Value (Type_Low_Bound (Universal_Integer));
2642 Hi : constant Uint := Expr_Value (Type_High_Bound (Universal_Integer));
2643 -- Allowed range of universal integer (= allowed range of enum lit vals)
2647 -- Minimum and maximum values of entries
2650 -- Pointer to node for literal providing max value
2653 if Ignore_Rep_Clauses then
2657 -- First some basic error checks
2660 Enumtype := Entity (Ident);
2662 if Enumtype = Any_Type
2663 or else Rep_Item_Too_Early (Enumtype, N)
2667 Enumtype := Underlying_Type (Enumtype);
2670 if not Is_Enumeration_Type (Enumtype) then
2672 ("enumeration type required, found}",
2673 Ident, First_Subtype (Enumtype));
2677 -- Ignore rep clause on generic actual type. This will already have
2678 -- been flagged on the template as an error, and this is the safest
2679 -- way to ensure we don't get a junk cascaded message in the instance.
2681 if Is_Generic_Actual_Type (Enumtype) then
2684 -- Type must be in current scope
2686 elsif Scope (Enumtype) /= Current_Scope then
2687 Error_Msg_N ("type must be declared in this scope", Ident);
2690 -- Type must be a first subtype
2692 elsif not Is_First_Subtype (Enumtype) then
2693 Error_Msg_N ("cannot give enumeration rep clause for subtype", N);
2696 -- Ignore duplicate rep clause
2698 elsif Has_Enumeration_Rep_Clause (Enumtype) then
2699 Error_Msg_N ("duplicate enumeration rep clause ignored", N);
2702 -- Don't allow rep clause for standard [wide_[wide_]]character
2704 elsif Is_Standard_Character_Type (Enumtype) then
2705 Error_Msg_N ("enumeration rep clause not allowed for this type", N);
2708 -- Check that the expression is a proper aggregate (no parentheses)
2710 elsif Paren_Count (Aggr) /= 0 then
2712 ("extra parentheses surrounding aggregate not allowed",
2716 -- All tests passed, so set rep clause in place
2719 Set_Has_Enumeration_Rep_Clause (Enumtype);
2720 Set_Has_Enumeration_Rep_Clause (Base_Type (Enumtype));
2723 -- Now we process the aggregate. Note that we don't use the normal
2724 -- aggregate code for this purpose, because we don't want any of the
2725 -- normal expansion activities, and a number of special semantic
2726 -- rules apply (including the component type being any integer type)
2728 Elit := First_Literal (Enumtype);
2730 -- First the positional entries if any
2732 if Present (Expressions (Aggr)) then
2733 Expr := First (Expressions (Aggr));
2734 while Present (Expr) loop
2736 Error_Msg_N ("too many entries in aggregate", Expr);
2740 Val := Static_Integer (Expr);
2742 -- Err signals that we found some incorrect entries processing
2743 -- the list. The final checks for completeness and ordering are
2744 -- skipped in this case.
2746 if Val = No_Uint then
2748 elsif Val < Lo or else Hi < Val then
2749 Error_Msg_N ("value outside permitted range", Expr);
2753 Set_Enumeration_Rep (Elit, Val);
2754 Set_Enumeration_Rep_Expr (Elit, Expr);
2760 -- Now process the named entries if present
2762 if Present (Component_Associations (Aggr)) then
2763 Assoc := First (Component_Associations (Aggr));
2764 while Present (Assoc) loop
2765 Choice := First (Choices (Assoc));
2767 if Present (Next (Choice)) then
2769 ("multiple choice not allowed here", Next (Choice));
2773 if Nkind (Choice) = N_Others_Choice then
2774 Error_Msg_N ("others choice not allowed here", Choice);
2777 elsif Nkind (Choice) = N_Range then
2778 -- ??? should allow zero/one element range here
2779 Error_Msg_N ("range not allowed here", Choice);
2783 Analyze_And_Resolve (Choice, Enumtype);
2785 if Is_Entity_Name (Choice)
2786 and then Is_Type (Entity (Choice))
2788 Error_Msg_N ("subtype name not allowed here", Choice);
2790 -- ??? should allow static subtype with zero/one entry
2792 elsif Etype (Choice) = Base_Type (Enumtype) then
2793 if not Is_Static_Expression (Choice) then
2794 Flag_Non_Static_Expr
2795 ("non-static expression used for choice!", Choice);
2799 Elit := Expr_Value_E (Choice);
2801 if Present (Enumeration_Rep_Expr (Elit)) then
2802 Error_Msg_Sloc := Sloc (Enumeration_Rep_Expr (Elit));
2804 ("representation for& previously given#",
2809 Set_Enumeration_Rep_Expr (Elit, Expression (Assoc));
2811 Expr := Expression (Assoc);
2812 Val := Static_Integer (Expr);
2814 if Val = No_Uint then
2817 elsif Val < Lo or else Hi < Val then
2818 Error_Msg_N ("value outside permitted range", Expr);
2822 Set_Enumeration_Rep (Elit, Val);
2831 -- Aggregate is fully processed. Now we check that a full set of
2832 -- representations was given, and that they are in range and in order.
2833 -- These checks are only done if no other errors occurred.
2839 Elit := First_Literal (Enumtype);
2840 while Present (Elit) loop
2841 if No (Enumeration_Rep_Expr (Elit)) then
2842 Error_Msg_NE ("missing representation for&!", N, Elit);
2845 Val := Enumeration_Rep (Elit);
2847 if Min = No_Uint then
2851 if Val /= No_Uint then
2852 if Max /= No_Uint and then Val <= Max then
2854 ("enumeration value for& not ordered!",
2855 Enumeration_Rep_Expr (Elit), Elit);
2858 Max_Node := Enumeration_Rep_Expr (Elit);
2862 -- If there is at least one literal whose representation is not
2863 -- equal to the Pos value, then note that this enumeration type
2864 -- has a non-standard representation.
2866 if Val /= Enumeration_Pos (Elit) then
2867 Set_Has_Non_Standard_Rep (Base_Type (Enumtype));
2874 -- Now set proper size information
2877 Minsize : Uint := UI_From_Int (Minimum_Size (Enumtype));
2880 if Has_Size_Clause (Enumtype) then
2882 -- All OK, if size is OK now
2884 if RM_Size (Enumtype) >= Minsize then
2888 -- Try if we can get by with biasing
2891 UI_From_Int (Minimum_Size (Enumtype, Biased => True));
2893 -- Error message if even biasing does not work
2895 if RM_Size (Enumtype) < Minsize then
2896 Error_Msg_Uint_1 := RM_Size (Enumtype);
2897 Error_Msg_Uint_2 := Max;
2899 ("previously given size (^) is too small "
2900 & "for this value (^)", Max_Node);
2902 -- If biasing worked, indicate that we now have biased rep
2906 (Enumtype, Size_Clause (Enumtype), "size clause");
2911 Set_RM_Size (Enumtype, Minsize);
2912 Set_Enum_Esize (Enumtype);
2915 Set_RM_Size (Base_Type (Enumtype), RM_Size (Enumtype));
2916 Set_Esize (Base_Type (Enumtype), Esize (Enumtype));
2917 Set_Alignment (Base_Type (Enumtype), Alignment (Enumtype));
2921 -- We repeat the too late test in case it froze itself!
2923 if Rep_Item_Too_Late (Enumtype, N) then
2926 end Analyze_Enumeration_Representation_Clause;
2928 ----------------------------
2929 -- Analyze_Free_Statement --
2930 ----------------------------
2932 procedure Analyze_Free_Statement (N : Node_Id) is
2934 Analyze (Expression (N));
2935 end Analyze_Free_Statement;
2937 ---------------------------
2938 -- Analyze_Freeze_Entity --
2939 ---------------------------
2941 procedure Analyze_Freeze_Entity (N : Node_Id) is
2942 E : constant Entity_Id := Entity (N);
2945 -- Remember that we are processing a freezing entity. Required to
2946 -- ensure correct decoration of internal entities associated with
2947 -- interfaces (see New_Overloaded_Entity).
2949 Inside_Freezing_Actions := Inside_Freezing_Actions + 1;
2951 -- For tagged types covering interfaces add internal entities that link
2952 -- the primitives of the interfaces with the primitives that cover them.
2953 -- Note: These entities were originally generated only when generating
2954 -- code because their main purpose was to provide support to initialize
2955 -- the secondary dispatch tables. They are now generated also when
2956 -- compiling with no code generation to provide ASIS the relationship
2957 -- between interface primitives and tagged type primitives. They are
2958 -- also used to locate primitives covering interfaces when processing
2959 -- generics (see Derive_Subprograms).
2961 if Ada_Version >= Ada_2005
2962 and then Ekind (E) = E_Record_Type
2963 and then Is_Tagged_Type (E)
2964 and then not Is_Interface (E)
2965 and then Has_Interfaces (E)
2967 -- This would be a good common place to call the routine that checks
2968 -- overriding of interface primitives (and thus factorize calls to
2969 -- Check_Abstract_Overriding located at different contexts in the
2970 -- compiler). However, this is not possible because it causes
2971 -- spurious errors in case of late overriding.
2973 Add_Internal_Interface_Entities (E);
2978 if Ekind (E) = E_Record_Type
2979 and then Is_CPP_Class (E)
2980 and then Is_Tagged_Type (E)
2981 and then Tagged_Type_Expansion
2982 and then Expander_Active
2984 if CPP_Num_Prims (E) = 0 then
2986 -- If the CPP type has user defined components then it must import
2987 -- primitives from C++. This is required because if the C++ class
2988 -- has no primitives then the C++ compiler does not added the _tag
2989 -- component to the type.
2991 pragma Assert (Chars (First_Entity (E)) = Name_uTag);
2993 if First_Entity (E) /= Last_Entity (E) then
2995 ("?'C'P'P type must import at least one primitive from C++",
3000 -- Check that all its primitives are abstract or imported from C++.
3001 -- Check also availability of the C++ constructor.
3004 Has_Constructors : constant Boolean := Has_CPP_Constructors (E);
3006 Error_Reported : Boolean := False;
3010 Elmt := First_Elmt (Primitive_Operations (E));
3011 while Present (Elmt) loop
3012 Prim := Node (Elmt);
3014 if Comes_From_Source (Prim) then
3015 if Is_Abstract_Subprogram (Prim) then
3018 elsif not Is_Imported (Prim)
3019 or else Convention (Prim) /= Convention_CPP
3022 ("?primitives of 'C'P'P types must be imported from C++"
3023 & " or abstract", Prim);
3025 elsif not Has_Constructors
3026 and then not Error_Reported
3028 Error_Msg_Name_1 := Chars (E);
3030 ("?'C'P'P constructor required for type %", Prim);
3031 Error_Reported := True;
3040 Inside_Freezing_Actions := Inside_Freezing_Actions - 1;
3042 -- If we have a type with predicates, build predicate function
3044 if Is_Type (E) and then Has_Predicates (E) then
3045 Build_Predicate_Function (E, N);
3048 -- If type has delayed aspects, this is where we do the preanalysis
3049 -- at the freeze point, as part of the consistent visibility check.
3050 -- Note that this must be done after calling Build_Predicate_Function,
3051 -- since that call marks occurrences of the subtype name in the saved
3052 -- expression so that they will not cause trouble in the preanalysis.
3054 if Has_Delayed_Aspects (E) then
3059 -- Look for aspect specification entries for this entity
3061 Ritem := First_Rep_Item (E);
3062 while Present (Ritem) loop
3063 if Nkind (Ritem) = N_Aspect_Specification
3064 and then Entity (Ritem) = E
3065 and then Is_Delayed_Aspect (Ritem)
3067 Check_Aspect_At_Freeze_Point (Ritem);
3070 Next_Rep_Item (Ritem);
3074 end Analyze_Freeze_Entity;
3076 ------------------------------------------
3077 -- Analyze_Record_Representation_Clause --
3078 ------------------------------------------
3080 -- Note: we check as much as we can here, but we can't do any checks
3081 -- based on the position values (e.g. overlap checks) until freeze time
3082 -- because especially in Ada 2005 (machine scalar mode), the processing
3083 -- for non-standard bit order can substantially change the positions.
3084 -- See procedure Check_Record_Representation_Clause (called from Freeze)
3085 -- for the remainder of this processing.
3087 procedure Analyze_Record_Representation_Clause (N : Node_Id) is
3088 Ident : constant Node_Id := Identifier (N);
3093 Hbit : Uint := Uint_0;
3097 Rectype : Entity_Id;
3099 CR_Pragma : Node_Id := Empty;
3100 -- Points to N_Pragma node if Complete_Representation pragma present
3103 if Ignore_Rep_Clauses then
3108 Rectype := Entity (Ident);
3110 if Rectype = Any_Type
3111 or else Rep_Item_Too_Early (Rectype, N)
3115 Rectype := Underlying_Type (Rectype);
3118 -- First some basic error checks
3120 if not Is_Record_Type (Rectype) then
3122 ("record type required, found}", Ident, First_Subtype (Rectype));
3125 elsif Scope (Rectype) /= Current_Scope then
3126 Error_Msg_N ("type must be declared in this scope", N);
3129 elsif not Is_First_Subtype (Rectype) then
3130 Error_Msg_N ("cannot give record rep clause for subtype", N);
3133 elsif Has_Record_Rep_Clause (Rectype) then
3134 Error_Msg_N ("duplicate record rep clause ignored", N);
3137 elsif Rep_Item_Too_Late (Rectype, N) then
3141 if Present (Mod_Clause (N)) then
3143 Loc : constant Source_Ptr := Sloc (N);
3144 M : constant Node_Id := Mod_Clause (N);
3145 P : constant List_Id := Pragmas_Before (M);
3149 pragma Warnings (Off, Mod_Val);
3152 Check_Restriction (No_Obsolescent_Features, Mod_Clause (N));
3154 if Warn_On_Obsolescent_Feature then
3156 ("mod clause is an obsolescent feature (RM J.8)?", N);
3158 ("\use alignment attribute definition clause instead?", N);
3165 -- In ASIS_Mode mode, expansion is disabled, but we must convert
3166 -- the Mod clause into an alignment clause anyway, so that the
3167 -- back-end can compute and back-annotate properly the size and
3168 -- alignment of types that may include this record.
3170 -- This seems dubious, this destroys the source tree in a manner
3171 -- not detectable by ASIS ???
3173 if Operating_Mode = Check_Semantics
3177 Make_Attribute_Definition_Clause (Loc,
3178 Name => New_Reference_To (Base_Type (Rectype), Loc),
3179 Chars => Name_Alignment,
3180 Expression => Relocate_Node (Expression (M)));
3182 Set_From_At_Mod (AtM_Nod);
3183 Insert_After (N, AtM_Nod);
3184 Mod_Val := Get_Alignment_Value (Expression (AtM_Nod));
3185 Set_Mod_Clause (N, Empty);
3188 -- Get the alignment value to perform error checking
3190 Mod_Val := Get_Alignment_Value (Expression (M));
3195 -- For untagged types, clear any existing component clauses for the
3196 -- type. If the type is derived, this is what allows us to override
3197 -- a rep clause for the parent. For type extensions, the representation
3198 -- of the inherited components is inherited, so we want to keep previous
3199 -- component clauses for completeness.
3201 if not Is_Tagged_Type (Rectype) then
3202 Comp := First_Component_Or_Discriminant (Rectype);
3203 while Present (Comp) loop
3204 Set_Component_Clause (Comp, Empty);
3205 Next_Component_Or_Discriminant (Comp);
3209 -- All done if no component clauses
3211 CC := First (Component_Clauses (N));
3217 -- A representation like this applies to the base type
3219 Set_Has_Record_Rep_Clause (Base_Type (Rectype));
3220 Set_Has_Non_Standard_Rep (Base_Type (Rectype));
3221 Set_Has_Specified_Layout (Base_Type (Rectype));
3223 -- Process the component clauses
3225 while Present (CC) loop
3229 if Nkind (CC) = N_Pragma then
3232 -- The only pragma of interest is Complete_Representation
3234 if Pragma_Name (CC) = Name_Complete_Representation then
3238 -- Processing for real component clause
3241 Posit := Static_Integer (Position (CC));
3242 Fbit := Static_Integer (First_Bit (CC));
3243 Lbit := Static_Integer (Last_Bit (CC));
3246 and then Fbit /= No_Uint
3247 and then Lbit /= No_Uint
3251 ("position cannot be negative", Position (CC));
3255 ("first bit cannot be negative", First_Bit (CC));
3257 -- The Last_Bit specified in a component clause must not be
3258 -- less than the First_Bit minus one (RM-13.5.1(10)).
3260 elsif Lbit < Fbit - 1 then
3262 ("last bit cannot be less than first bit minus one",
3265 -- Values look OK, so find the corresponding record component
3266 -- Even though the syntax allows an attribute reference for
3267 -- implementation-defined components, GNAT does not allow the
3268 -- tag to get an explicit position.
3270 elsif Nkind (Component_Name (CC)) = N_Attribute_Reference then
3271 if Attribute_Name (Component_Name (CC)) = Name_Tag then
3272 Error_Msg_N ("position of tag cannot be specified", CC);
3274 Error_Msg_N ("illegal component name", CC);
3278 Comp := First_Entity (Rectype);
3279 while Present (Comp) loop
3280 exit when Chars (Comp) = Chars (Component_Name (CC));
3286 -- Maybe component of base type that is absent from
3287 -- statically constrained first subtype.
3289 Comp := First_Entity (Base_Type (Rectype));
3290 while Present (Comp) loop
3291 exit when Chars (Comp) = Chars (Component_Name (CC));
3298 ("component clause is for non-existent field", CC);
3300 -- Ada 2012 (AI05-0026): Any name that denotes a
3301 -- discriminant of an object of an unchecked union type
3302 -- shall not occur within a record_representation_clause.
3304 -- The general restriction of using record rep clauses on
3305 -- Unchecked_Union types has now been lifted. Since it is
3306 -- possible to introduce a record rep clause which mentions
3307 -- the discriminant of an Unchecked_Union in non-Ada 2012
3308 -- code, this check is applied to all versions of the
3311 elsif Ekind (Comp) = E_Discriminant
3312 and then Is_Unchecked_Union (Rectype)
3315 ("cannot reference discriminant of Unchecked_Union",
3316 Component_Name (CC));
3318 elsif Present (Component_Clause (Comp)) then
3320 -- Diagnose duplicate rep clause, or check consistency
3321 -- if this is an inherited component. In a double fault,
3322 -- there may be a duplicate inconsistent clause for an
3323 -- inherited component.
3325 if Scope (Original_Record_Component (Comp)) = Rectype
3326 or else Parent (Component_Clause (Comp)) = N
3328 Error_Msg_Sloc := Sloc (Component_Clause (Comp));
3329 Error_Msg_N ("component clause previously given#", CC);
3333 Rep1 : constant Node_Id := Component_Clause (Comp);
3335 if Intval (Position (Rep1)) /=
3336 Intval (Position (CC))
3337 or else Intval (First_Bit (Rep1)) /=
3338 Intval (First_Bit (CC))
3339 or else Intval (Last_Bit (Rep1)) /=
3340 Intval (Last_Bit (CC))
3342 Error_Msg_N ("component clause inconsistent "
3343 & "with representation of ancestor", CC);
3344 elsif Warn_On_Redundant_Constructs then
3345 Error_Msg_N ("?redundant component clause "
3346 & "for inherited component!", CC);
3351 -- Normal case where this is the first component clause we
3352 -- have seen for this entity, so set it up properly.
3355 -- Make reference for field in record rep clause and set
3356 -- appropriate entity field in the field identifier.
3359 (Comp, Component_Name (CC), Set_Ref => False);
3360 Set_Entity (Component_Name (CC), Comp);
3362 -- Update Fbit and Lbit to the actual bit number
3364 Fbit := Fbit + UI_From_Int (SSU) * Posit;
3365 Lbit := Lbit + UI_From_Int (SSU) * Posit;
3367 if Has_Size_Clause (Rectype)
3368 and then Esize (Rectype) <= Lbit
3371 ("bit number out of range of specified size",
3374 Set_Component_Clause (Comp, CC);
3375 Set_Component_Bit_Offset (Comp, Fbit);
3376 Set_Esize (Comp, 1 + (Lbit - Fbit));
3377 Set_Normalized_First_Bit (Comp, Fbit mod SSU);
3378 Set_Normalized_Position (Comp, Fbit / SSU);
3380 if Warn_On_Overridden_Size
3381 and then Has_Size_Clause (Etype (Comp))
3382 and then RM_Size (Etype (Comp)) /= Esize (Comp)
3385 ("?component size overrides size clause for&",
3386 Component_Name (CC), Etype (Comp));
3389 -- This information is also set in the corresponding
3390 -- component of the base type, found by accessing the
3391 -- Original_Record_Component link if it is present.
3393 Ocomp := Original_Record_Component (Comp);
3400 (Component_Name (CC),
3406 (Comp, First_Node (CC), "component clause", Biased);
3408 if Present (Ocomp) then
3409 Set_Component_Clause (Ocomp, CC);
3410 Set_Component_Bit_Offset (Ocomp, Fbit);
3411 Set_Normalized_First_Bit (Ocomp, Fbit mod SSU);
3412 Set_Normalized_Position (Ocomp, Fbit / SSU);
3413 Set_Esize (Ocomp, 1 + (Lbit - Fbit));
3415 Set_Normalized_Position_Max
3416 (Ocomp, Normalized_Position (Ocomp));
3418 -- Note: we don't use Set_Biased here, because we
3419 -- already gave a warning above if needed, and we
3420 -- would get a duplicate for the same name here.
3422 Set_Has_Biased_Representation
3423 (Ocomp, Has_Biased_Representation (Comp));
3426 if Esize (Comp) < 0 then
3427 Error_Msg_N ("component size is negative", CC);
3438 -- Check missing components if Complete_Representation pragma appeared
3440 if Present (CR_Pragma) then
3441 Comp := First_Component_Or_Discriminant (Rectype);
3442 while Present (Comp) loop
3443 if No (Component_Clause (Comp)) then
3445 ("missing component clause for &", CR_Pragma, Comp);
3448 Next_Component_Or_Discriminant (Comp);
3451 -- If no Complete_Representation pragma, warn if missing components
3453 elsif Warn_On_Unrepped_Components then
3455 Num_Repped_Components : Nat := 0;
3456 Num_Unrepped_Components : Nat := 0;
3459 -- First count number of repped and unrepped components
3461 Comp := First_Component_Or_Discriminant (Rectype);
3462 while Present (Comp) loop
3463 if Present (Component_Clause (Comp)) then
3464 Num_Repped_Components := Num_Repped_Components + 1;
3466 Num_Unrepped_Components := Num_Unrepped_Components + 1;
3469 Next_Component_Or_Discriminant (Comp);
3472 -- We are only interested in the case where there is at least one
3473 -- unrepped component, and at least half the components have rep
3474 -- clauses. We figure that if less than half have them, then the
3475 -- partial rep clause is really intentional. If the component
3476 -- type has no underlying type set at this point (as for a generic
3477 -- formal type), we don't know enough to give a warning on the
3480 if Num_Unrepped_Components > 0
3481 and then Num_Unrepped_Components < Num_Repped_Components
3483 Comp := First_Component_Or_Discriminant (Rectype);
3484 while Present (Comp) loop
3485 if No (Component_Clause (Comp))
3486 and then Comes_From_Source (Comp)
3487 and then Present (Underlying_Type (Etype (Comp)))
3488 and then (Is_Scalar_Type (Underlying_Type (Etype (Comp)))
3489 or else Size_Known_At_Compile_Time
3490 (Underlying_Type (Etype (Comp))))
3491 and then not Has_Warnings_Off (Rectype)
3493 Error_Msg_Sloc := Sloc (Comp);
3495 ("?no component clause given for & declared #",
3499 Next_Component_Or_Discriminant (Comp);
3504 end Analyze_Record_Representation_Clause;
3506 -------------------------------
3507 -- Build_Invariant_Procedure --
3508 -------------------------------
3510 -- The procedure that is constructed here has the form
3512 -- procedure typInvariant (Ixxx : typ) is
3514 -- pragma Check (Invariant, exp, "failed invariant from xxx");
3515 -- pragma Check (Invariant, exp, "failed invariant from xxx");
3517 -- pragma Check (Invariant, exp, "failed inherited invariant from xxx");
3519 -- end typInvariant;
3521 procedure Build_Invariant_Procedure (Typ : Entity_Id; N : Node_Id) is
3522 Loc : constant Source_Ptr := Sloc (Typ);
3529 Visible_Decls : constant List_Id := Visible_Declarations (N);
3530 Private_Decls : constant List_Id := Private_Declarations (N);
3532 procedure Add_Invariants (T : Entity_Id; Inherit : Boolean);
3533 -- Appends statements to Stmts for any invariants in the rep item chain
3534 -- of the given type. If Inherit is False, then we only process entries
3535 -- on the chain for the type Typ. If Inherit is True, then we ignore any
3536 -- Invariant aspects, but we process all Invariant'Class aspects, adding
3537 -- "inherited" to the exception message and generating an informational
3538 -- message about the inheritance of an invariant.
3540 Object_Name : constant Name_Id := New_Internal_Name ('I');
3541 -- Name for argument of invariant procedure
3543 Object_Entity : constant Node_Id :=
3544 Make_Defining_Identifier (Loc, Object_Name);
3545 -- The procedure declaration entity for the argument
3547 --------------------
3548 -- Add_Invariants --
3549 --------------------
3551 procedure Add_Invariants (T : Entity_Id; Inherit : Boolean) is
3561 procedure Replace_Type_Reference (N : Node_Id);
3562 -- Replace a single occurrence N of the subtype name with a reference
3563 -- to the formal of the predicate function. N can be an identifier
3564 -- referencing the subtype, or a selected component, representing an
3565 -- appropriately qualified occurrence of the subtype name.
3567 procedure Replace_Type_References is
3568 new Replace_Type_References_Generic (Replace_Type_Reference);
3569 -- Traverse an expression replacing all occurrences of the subtype
3570 -- name with appropriate references to the object that is the formal
3571 -- parameter of the predicate function. Note that we must ensure
3572 -- that the type and entity information is properly set in the
3573 -- replacement node, since we will do a Preanalyze call of this
3574 -- expression without proper visibility of the procedure argument.
3576 ----------------------------
3577 -- Replace_Type_Reference --
3578 ----------------------------
3580 procedure Replace_Type_Reference (N : Node_Id) is
3582 -- Invariant'Class, replace with T'Class (obj)
3584 if Class_Present (Ritem) then
3586 Make_Type_Conversion (Loc,
3588 Make_Attribute_Reference (Loc,
3589 Prefix => New_Occurrence_Of (T, Loc),
3590 Attribute_Name => Name_Class),
3591 Expression => Make_Identifier (Loc, Object_Name)));
3593 Set_Entity (Expression (N), Object_Entity);
3594 Set_Etype (Expression (N), Typ);
3596 -- Invariant, replace with obj
3599 Rewrite (N, Make_Identifier (Loc, Object_Name));
3600 Set_Entity (N, Object_Entity);
3603 end Replace_Type_Reference;
3605 -- Start of processing for Add_Invariants
3608 Ritem := First_Rep_Item (T);
3609 while Present (Ritem) loop
3610 if Nkind (Ritem) = N_Pragma
3611 and then Pragma_Name (Ritem) = Name_Invariant
3613 Arg1 := First (Pragma_Argument_Associations (Ritem));
3614 Arg2 := Next (Arg1);
3615 Arg3 := Next (Arg2);
3617 Arg1 := Get_Pragma_Arg (Arg1);
3618 Arg2 := Get_Pragma_Arg (Arg2);
3620 -- For Inherit case, ignore Invariant, process only Class case
3623 if not Class_Present (Ritem) then
3627 -- For Inherit false, process only item for right type
3630 if Entity (Arg1) /= Typ then
3636 Stmts := Empty_List;
3639 Exp := New_Copy_Tree (Arg2);
3642 -- We need to replace any occurrences of the name of the type
3643 -- with references to the object, converted to type'Class in
3644 -- the case of Invariant'Class aspects.
3646 Replace_Type_References (Exp, Chars (T));
3648 -- If this invariant comes from an aspect, find the aspect
3649 -- specification, and replace the saved expression because
3650 -- we need the subtype references replaced for the calls to
3651 -- Preanalyze_Spec_Expressin in Check_Aspect_At_Freeze_Point
3652 -- and Check_Aspect_At_End_Of_Declarations.
3654 if From_Aspect_Specification (Ritem) then
3659 -- Loop to find corresponding aspect, note that this
3660 -- must be present given the pragma is marked delayed.
3662 Aitem := Next_Rep_Item (Ritem);
3663 while Present (Aitem) loop
3664 if Nkind (Aitem) = N_Aspect_Specification
3665 and then Aspect_Rep_Item (Aitem) = Ritem
3668 (Identifier (Aitem), New_Copy_Tree (Exp));
3672 Aitem := Next_Rep_Item (Aitem);
3677 -- Now we need to preanalyze the expression to properly capture
3678 -- the visibility in the visible part. The expression will not
3679 -- be analyzed for real until the body is analyzed, but that is
3680 -- at the end of the private part and has the wrong visibility.
3682 Set_Parent (Exp, N);
3683 Preanalyze_Spec_Expression (Exp, Standard_Boolean);
3685 -- Build first two arguments for Check pragma
3688 Make_Pragma_Argument_Association (Loc,
3689 Expression => Make_Identifier (Loc, Name_Invariant)),
3690 Make_Pragma_Argument_Association (Loc, Expression => Exp));
3692 -- Add message if present in Invariant pragma
3694 if Present (Arg3) then
3695 Str := Strval (Get_Pragma_Arg (Arg3));
3697 -- If inherited case, and message starts "failed invariant",
3698 -- change it to be "failed inherited invariant".
3701 String_To_Name_Buffer (Str);
3703 if Name_Buffer (1 .. 16) = "failed invariant" then
3704 Insert_Str_In_Name_Buffer ("inherited ", 8);
3705 Str := String_From_Name_Buffer;
3710 Make_Pragma_Argument_Association (Loc,
3711 Expression => Make_String_Literal (Loc, Str)));
3714 -- Add Check pragma to list of statements
3718 Pragma_Identifier =>
3719 Make_Identifier (Loc, Name_Check),
3720 Pragma_Argument_Associations => Assoc));
3722 -- If Inherited case and option enabled, output info msg. Note
3723 -- that we know this is a case of Invariant'Class.
3725 if Inherit and Opt.List_Inherited_Aspects then
3726 Error_Msg_Sloc := Sloc (Ritem);
3728 ("?info: & inherits `Invariant''Class` aspect from #",
3734 Next_Rep_Item (Ritem);
3738 -- Start of processing for Build_Invariant_Procedure
3744 Set_Etype (Object_Entity, Typ);
3746 -- Add invariants for the current type
3748 Add_Invariants (Typ, Inherit => False);
3750 -- Add invariants for parent types
3753 Current_Typ : Entity_Id;
3754 Parent_Typ : Entity_Id;
3759 Parent_Typ := Etype (Current_Typ);
3761 if Is_Private_Type (Parent_Typ)
3762 and then Present (Full_View (Base_Type (Parent_Typ)))
3764 Parent_Typ := Full_View (Base_Type (Parent_Typ));
3767 exit when Parent_Typ = Current_Typ;
3769 Current_Typ := Parent_Typ;
3770 Add_Invariants (Current_Typ, Inherit => True);
3774 -- Build the procedure if we generated at least one Check pragma
3776 if Stmts /= No_List then
3778 -- Build procedure declaration
3781 Make_Defining_Identifier (Loc,
3782 Chars => New_External_Name (Chars (Typ), "Invariant"));
3783 Set_Has_Invariants (SId);
3784 Set_Invariant_Procedure (Typ, SId);
3787 Make_Procedure_Specification (Loc,
3788 Defining_Unit_Name => SId,
3789 Parameter_Specifications => New_List (
3790 Make_Parameter_Specification (Loc,
3791 Defining_Identifier => Object_Entity,
3792 Parameter_Type => New_Occurrence_Of (Typ, Loc))));
3794 PDecl := Make_Subprogram_Declaration (Loc, Specification => Spec);
3796 -- Build procedure body
3799 Make_Defining_Identifier (Loc,
3800 Chars => New_External_Name (Chars (Typ), "Invariant"));
3803 Make_Procedure_Specification (Loc,
3804 Defining_Unit_Name => SId,
3805 Parameter_Specifications => New_List (
3806 Make_Parameter_Specification (Loc,
3807 Defining_Identifier =>
3808 Make_Defining_Identifier (Loc, Object_Name),
3809 Parameter_Type => New_Occurrence_Of (Typ, Loc))));
3812 Make_Subprogram_Body (Loc,
3813 Specification => Spec,
3814 Declarations => Empty_List,
3815 Handled_Statement_Sequence =>
3816 Make_Handled_Sequence_Of_Statements (Loc,
3817 Statements => Stmts));
3819 -- Insert procedure declaration and spec at the appropriate points.
3820 -- Skip this if there are no private declarations (that's an error
3821 -- that will be diagnosed elsewhere, and there is no point in having
3822 -- an invariant procedure set if the full declaration is missing).
3824 if Present (Private_Decls) then
3826 -- The spec goes at the end of visible declarations, but they have
3827 -- already been analyzed, so we need to explicitly do the analyze.
3829 Append_To (Visible_Decls, PDecl);
3832 -- The body goes at the end of the private declarations, which we
3833 -- have not analyzed yet, so we do not need to perform an explicit
3834 -- analyze call. We skip this if there are no private declarations
3835 -- (this is an error that will be caught elsewhere);
3837 Append_To (Private_Decls, PBody);
3840 end Build_Invariant_Procedure;
3842 ------------------------------
3843 -- Build_Predicate_Function --
3844 ------------------------------
3846 -- The procedure that is constructed here has the form
3848 -- function typPredicate (Ixxx : typ) return Boolean is
3851 -- exp1 and then exp2 and then ...
3852 -- and then typ1Predicate (typ1 (Ixxx))
3853 -- and then typ2Predicate (typ2 (Ixxx))
3855 -- end typPredicate;
3857 -- Here exp1, and exp2 are expressions from Predicate pragmas. Note that
3858 -- this is the point at which these expressions get analyzed, providing the
3859 -- required delay, and typ1, typ2, are entities from which predicates are
3860 -- inherited. Note that we do NOT generate Check pragmas, that's because we
3861 -- use this function even if checks are off, e.g. for membership tests.
3863 procedure Build_Predicate_Function (Typ : Entity_Id; N : Node_Id) is
3864 Loc : constant Source_Ptr := Sloc (Typ);
3871 -- This is the expression for the return statement in the function. It
3872 -- is build by connecting the component predicates with AND THEN.
3874 procedure Add_Call (T : Entity_Id);
3875 -- Includes a call to the predicate function for type T in Expr if T
3876 -- has predicates and Predicate_Function (T) is non-empty.
3878 procedure Add_Predicates;
3879 -- Appends expressions for any Predicate pragmas in the rep item chain
3880 -- Typ to Expr. Note that we look only at items for this exact entity.
3881 -- Inheritance of predicates for the parent type is done by calling the
3882 -- Predicate_Function of the parent type, using Add_Call above.
3884 Object_Name : constant Name_Id := New_Internal_Name ('I');
3885 -- Name for argument of Predicate procedure
3887 Object_Entity : constant Entity_Id :=
3888 Make_Defining_Identifier (Loc, Object_Name);
3889 -- The entity for the spec entity for the argument
3891 Dynamic_Predicate_Present : Boolean := False;
3892 -- Set True if a dynamic predicate is present, results in the entire
3893 -- predicate being considered dynamic even if it looks static
3895 Static_Predicate_Present : Node_Id := Empty;
3896 -- Set to N_Pragma node for a static predicate if one is encountered.
3902 procedure Add_Call (T : Entity_Id) is
3906 if Present (T) and then Present (Predicate_Function (T)) then
3907 Set_Has_Predicates (Typ);
3909 -- Build the call to the predicate function of T
3913 (T, Convert_To (T, Make_Identifier (Loc, Object_Name)));
3915 -- Add call to evolving expression, using AND THEN if needed
3922 Left_Opnd => Relocate_Node (Expr),
3926 -- Output info message on inheritance if required. Note we do not
3927 -- give this information for generic actual types, since it is
3928 -- unwelcome noise in that case in instantiations. We also
3929 -- generally suppress the message in instantiations, and also
3930 -- if it involves internal names.
3932 if Opt.List_Inherited_Aspects
3933 and then not Is_Generic_Actual_Type (Typ)
3934 and then Instantiation_Depth (Sloc (Typ)) = 0
3935 and then not Is_Internal_Name (Chars (T))
3936 and then not Is_Internal_Name (Chars (Typ))
3938 Error_Msg_Sloc := Sloc (Predicate_Function (T));
3939 Error_Msg_Node_2 := T;
3940 Error_Msg_N ("?info: & inherits predicate from & #", Typ);
3945 --------------------
3946 -- Add_Predicates --
3947 --------------------
3949 procedure Add_Predicates is
3954 procedure Replace_Type_Reference (N : Node_Id);
3955 -- Replace a single occurrence N of the subtype name with a reference
3956 -- to the formal of the predicate function. N can be an identifier
3957 -- referencing the subtype, or a selected component, representing an
3958 -- appropriately qualified occurrence of the subtype name.
3960 procedure Replace_Type_References is
3961 new Replace_Type_References_Generic (Replace_Type_Reference);
3962 -- Traverse an expression changing every occurrence of an identifier
3963 -- whose name matches the name of the subtype with a reference to
3964 -- the formal parameter of the predicate function.
3966 ----------------------------
3967 -- Replace_Type_Reference --
3968 ----------------------------
3970 procedure Replace_Type_Reference (N : Node_Id) is
3972 Rewrite (N, Make_Identifier (Loc, Object_Name));
3973 Set_Entity (N, Object_Entity);
3975 end Replace_Type_Reference;
3977 -- Start of processing for Add_Predicates
3980 Ritem := First_Rep_Item (Typ);
3981 while Present (Ritem) loop
3982 if Nkind (Ritem) = N_Pragma
3983 and then Pragma_Name (Ritem) = Name_Predicate
3985 if From_Dynamic_Predicate (Ritem) then
3986 Dynamic_Predicate_Present := True;
3987 elsif From_Static_Predicate (Ritem) then
3988 Static_Predicate_Present := Ritem;
3991 -- Acquire arguments
3993 Arg1 := First (Pragma_Argument_Associations (Ritem));
3994 Arg2 := Next (Arg1);
3996 Arg1 := Get_Pragma_Arg (Arg1);
3997 Arg2 := Get_Pragma_Arg (Arg2);
3999 -- See if this predicate pragma is for the current type
4001 if Entity (Arg1) = Typ then
4003 -- We have a match, this entry is for our subtype
4005 -- We need to replace any occurrences of the name of the
4006 -- type with references to the object.
4008 Replace_Type_References (Arg2, Chars (Typ));
4010 -- If this predicate comes from an aspect, find the aspect
4011 -- specification, and replace the saved expression because
4012 -- we need the subtype references replaced for the calls to
4013 -- Preanalyze_Spec_Expressin in Check_Aspect_At_Freeze_Point
4014 -- and Check_Aspect_At_End_Of_Declarations.
4016 if From_Aspect_Specification (Ritem) then
4021 -- Loop to find corresponding aspect, note that this
4022 -- must be present given the pragma is marked delayed.
4024 Aitem := Next_Rep_Item (Ritem);
4026 if Nkind (Aitem) = N_Aspect_Specification
4027 and then Aspect_Rep_Item (Aitem) = Ritem
4030 (Identifier (Aitem), New_Copy_Tree (Arg2));
4034 Aitem := Next_Rep_Item (Aitem);
4039 -- Now we can add the expression
4042 Expr := Relocate_Node (Arg2);
4044 -- There already was a predicate, so add to it
4049 Left_Opnd => Relocate_Node (Expr),
4050 Right_Opnd => Relocate_Node (Arg2));
4055 Next_Rep_Item (Ritem);
4059 -- Start of processing for Build_Predicate_Function
4062 -- Initialize for construction of statement list
4066 -- Return if already built or if type does not have predicates
4068 if not Has_Predicates (Typ)
4069 or else Present (Predicate_Function (Typ))
4074 -- Add Predicates for the current type
4078 -- Add predicates for ancestor if present
4081 Atyp : constant Entity_Id := Nearest_Ancestor (Typ);
4083 if Present (Atyp) then
4088 -- If we have predicates, build the function
4090 if Present (Expr) then
4092 -- Build function declaration
4094 pragma Assert (Has_Predicates (Typ));
4096 Make_Defining_Identifier (Loc,
4097 Chars => New_External_Name (Chars (Typ), "Predicate"));
4098 Set_Has_Predicates (SId);
4099 Set_Predicate_Function (Typ, SId);
4102 Make_Function_Specification (Loc,
4103 Defining_Unit_Name => SId,
4104 Parameter_Specifications => New_List (
4105 Make_Parameter_Specification (Loc,
4106 Defining_Identifier => Object_Entity,
4107 Parameter_Type => New_Occurrence_Of (Typ, Loc))),
4108 Result_Definition =>
4109 New_Occurrence_Of (Standard_Boolean, Loc));
4111 FDecl := Make_Subprogram_Declaration (Loc, Specification => Spec);
4113 -- Build function body
4116 Make_Defining_Identifier (Loc,
4117 Chars => New_External_Name (Chars (Typ), "Predicate"));
4120 Make_Function_Specification (Loc,
4121 Defining_Unit_Name => SId,
4122 Parameter_Specifications => New_List (
4123 Make_Parameter_Specification (Loc,
4124 Defining_Identifier =>
4125 Make_Defining_Identifier (Loc, Object_Name),
4127 New_Occurrence_Of (Typ, Loc))),
4128 Result_Definition =>
4129 New_Occurrence_Of (Standard_Boolean, Loc));
4132 Make_Subprogram_Body (Loc,
4133 Specification => Spec,
4134 Declarations => Empty_List,
4135 Handled_Statement_Sequence =>
4136 Make_Handled_Sequence_Of_Statements (Loc,
4137 Statements => New_List (
4138 Make_Simple_Return_Statement (Loc,
4139 Expression => Expr))));
4141 -- Insert declaration before freeze node and body after
4143 Insert_Before_And_Analyze (N, FDecl);
4144 Insert_After_And_Analyze (N, FBody);
4146 -- Deal with static predicate case
4148 if Ekind_In (Typ, E_Enumeration_Subtype,
4149 E_Modular_Integer_Subtype,
4150 E_Signed_Integer_Subtype)
4151 and then Is_Static_Subtype (Typ)
4152 and then not Dynamic_Predicate_Present
4154 Build_Static_Predicate (Typ, Expr, Object_Name);
4156 if Present (Static_Predicate_Present)
4157 and No (Static_Predicate (Typ))
4160 ("expression does not have required form for "
4161 & "static predicate",
4162 Next (First (Pragma_Argument_Associations
4163 (Static_Predicate_Present))));
4167 end Build_Predicate_Function;
4169 ----------------------------
4170 -- Build_Static_Predicate --
4171 ----------------------------
4173 procedure Build_Static_Predicate
4178 Loc : constant Source_Ptr := Sloc (Expr);
4180 Non_Static : exception;
4181 -- Raised if something non-static is found
4183 Btyp : constant Entity_Id := Base_Type (Typ);
4185 BLo : constant Uint := Expr_Value (Type_Low_Bound (Btyp));
4186 BHi : constant Uint := Expr_Value (Type_High_Bound (Btyp));
4187 -- Low bound and high bound value of base type of Typ
4189 TLo : constant Uint := Expr_Value (Type_Low_Bound (Typ));
4190 THi : constant Uint := Expr_Value (Type_High_Bound (Typ));
4191 -- Low bound and high bound values of static subtype Typ
4196 -- One entry in a Rlist value, a single REnt (range entry) value
4197 -- denotes one range from Lo to Hi. To represent a single value
4198 -- range Lo = Hi = value.
4200 type RList is array (Nat range <>) of REnt;
4201 -- A list of ranges. The ranges are sorted in increasing order,
4202 -- and are disjoint (there is a gap of at least one value between
4203 -- each range in the table). A value is in the set of ranges in
4204 -- Rlist if it lies within one of these ranges
4206 False_Range : constant RList :=
4207 RList'(1 .. 0 => REnt'(No_Uint, No_Uint));
4208 -- An empty set of ranges represents a range list that can never be
4209 -- satisfied, since there are no ranges in which the value could lie,
4210 -- so it does not lie in any of them. False_Range is a canonical value
4211 -- for this empty set, but general processing should test for an Rlist
4212 -- with length zero (see Is_False predicate), since other null ranges
4213 -- may appear which must be treated as False.
4215 True_Range : constant RList := RList'(1 => REnt'(BLo, BHi));
4216 -- Range representing True, value must be in the base range
4218 function "and" (Left, Right : RList) return RList;
4219 -- And's together two range lists, returning a range list. This is
4220 -- a set intersection operation.
4222 function "or" (Left, Right : RList) return RList;
4223 -- Or's together two range lists, returning a range list. This is a
4224 -- set union operation.
4226 function "not" (Right : RList) return RList;
4227 -- Returns complement of a given range list, i.e. a range list
4228 -- representing all the values in TLo .. THi that are not in the
4229 -- input operand Right.
4231 function Build_Val (V : Uint) return Node_Id;
4232 -- Return an analyzed N_Identifier node referencing this value, suitable
4233 -- for use as an entry in the Static_Predicate list. This node is typed
4234 -- with the base type.
4236 function Build_Range (Lo, Hi : Uint) return Node_Id;
4237 -- Return an analyzed N_Range node referencing this range, suitable
4238 -- for use as an entry in the Static_Predicate list. This node is typed
4239 -- with the base type.
4241 function Get_RList (Exp : Node_Id) return RList;
4242 -- This is a recursive routine that converts the given expression into
4243 -- a list of ranges, suitable for use in building the static predicate.
4245 function Is_False (R : RList) return Boolean;
4246 pragma Inline (Is_False);
4247 -- Returns True if the given range list is empty, and thus represents
4248 -- a False list of ranges that can never be satisfied.
4250 function Is_True (R : RList) return Boolean;
4251 -- Returns True if R trivially represents the True predicate by having
4252 -- a single range from BLo to BHi.
4254 function Is_Type_Ref (N : Node_Id) return Boolean;
4255 pragma Inline (Is_Type_Ref);
4256 -- Returns if True if N is a reference to the type for the predicate in
4257 -- the expression (i.e. if it is an identifier whose Chars field matches
4258 -- the Nam given in the call).
4260 function Lo_Val (N : Node_Id) return Uint;
4261 -- Given static expression or static range from a Static_Predicate list,
4262 -- gets expression value or low bound of range.
4264 function Hi_Val (N : Node_Id) return Uint;
4265 -- Given static expression or static range from a Static_Predicate list,
4266 -- gets expression value of high bound of range.
4268 function Membership_Entry (N : Node_Id) return RList;
4269 -- Given a single membership entry (range, value, or subtype), returns
4270 -- the corresponding range list. Raises Static_Error if not static.
4272 function Membership_Entries (N : Node_Id) return RList;
4273 -- Given an element on an alternatives list of a membership operation,
4274 -- returns the range list corresponding to this entry and all following
4275 -- entries (i.e. returns the "or" of this list of values).
4277 function Stat_Pred (Typ : Entity_Id) return RList;
4278 -- Given a type, if it has a static predicate, then return the predicate
4279 -- as a range list, otherwise raise Non_Static.
4285 function "and" (Left, Right : RList) return RList is
4287 -- First range of result
4289 SLeft : Nat := Left'First;
4290 -- Start of rest of left entries
4292 SRight : Nat := Right'First;
4293 -- Start of rest of right entries
4296 -- If either range is True, return the other
4298 if Is_True (Left) then
4300 elsif Is_True (Right) then
4304 -- If either range is False, return False
4306 if Is_False (Left) or else Is_False (Right) then
4310 -- Loop to remove entries at start that are disjoint, and thus
4311 -- just get discarded from the result entirely.
4314 -- If no operands left in either operand, result is false
4316 if SLeft > Left'Last or else SRight > Right'Last then
4319 -- Discard first left operand entry if disjoint with right
4321 elsif Left (SLeft).Hi < Right (SRight).Lo then
4324 -- Discard first right operand entry if disjoint with left
4326 elsif Right (SRight).Hi < Left (SLeft).Lo then
4327 SRight := SRight + 1;
4329 -- Otherwise we have an overlapping entry
4336 -- Now we have two non-null operands, and first entries overlap.
4337 -- The first entry in the result will be the overlapping part of
4338 -- these two entries.
4340 FEnt := REnt'(Lo => UI_Max (Left (SLeft).Lo, Right (SRight).Lo),
4341 Hi => UI_Min (Left (SLeft).Hi, Right (SRight).Hi));
4343 -- Now we can remove the entry that ended at a lower value, since
4344 -- its contribution is entirely contained in Fent.
4346 if Left (SLeft).Hi <= Right (SRight).Hi then
4349 SRight := SRight + 1;
4352 -- Compute result by concatenating this first entry with the "and"
4353 -- of the remaining parts of the left and right operands. Note that
4354 -- if either of these is empty, "and" will yield empty, so that we
4355 -- will end up with just Fent, which is what we want in that case.
4358 FEnt & (Left (SLeft .. Left'Last) and Right (SRight .. Right'Last));
4365 function "not" (Right : RList) return RList is
4367 -- Return True if False range
4369 if Is_False (Right) then
4373 -- Return False if True range
4375 if Is_True (Right) then
4379 -- Here if not trivial case
4382 Result : RList (1 .. Right'Length + 1);
4383 -- May need one more entry for gap at beginning and end
4386 -- Number of entries stored in Result
4391 if Right (Right'First).Lo > TLo then
4393 Result (Count) := REnt'(TLo, Right (Right'First).Lo - 1);
4396 -- Gaps between ranges
4398 for J in Right'First .. Right'Last - 1 loop
4401 REnt'(Right (J).Hi + 1, Right (J + 1).Lo - 1);
4406 if Right (Right'Last).Hi < THi then
4408 Result (Count) := REnt'(Right (Right'Last).Hi + 1, THi);
4411 return Result (1 .. Count);
4419 function "or" (Left, Right : RList) return RList is
4421 -- First range of result
4423 SLeft : Nat := Left'First;
4424 -- Start of rest of left entries
4426 SRight : Nat := Right'First;
4427 -- Start of rest of right entries
4430 -- If either range is True, return True
4432 if Is_True (Left) or else Is_True (Right) then
4436 -- If either range is False (empty), return the other
4438 if Is_False (Left) then
4440 elsif Is_False (Right) then
4444 -- Initialize result first entry from left or right operand
4445 -- depending on which starts with the lower range.
4447 if Left (SLeft).Lo < Right (SRight).Lo then
4448 FEnt := Left (SLeft);
4451 FEnt := Right (SRight);
4452 SRight := SRight + 1;
4455 -- This loop eats ranges from left and right operands that
4456 -- are contiguous with the first range we are gathering.
4459 -- Eat first entry in left operand if contiguous or
4460 -- overlapped by gathered first operand of result.
4462 if SLeft <= Left'Last
4463 and then Left (SLeft).Lo <= FEnt.Hi + 1
4465 FEnt.Hi := UI_Max (FEnt.Hi, Left (SLeft).Hi);
4468 -- Eat first entry in right operand if contiguous or
4469 -- overlapped by gathered right operand of result.
4471 elsif SRight <= Right'Last
4472 and then Right (SRight).Lo <= FEnt.Hi + 1
4474 FEnt.Hi := UI_Max (FEnt.Hi, Right (SRight).Hi);
4475 SRight := SRight + 1;
4477 -- All done if no more entries to eat!
4484 -- Obtain result as the first entry we just computed, concatenated
4485 -- to the "or" of the remaining results (if one operand is empty,
4486 -- this will just concatenate with the other
4489 FEnt & (Left (SLeft .. Left'Last) or Right (SRight .. Right'Last));
4496 function Build_Range (Lo, Hi : Uint) return Node_Id is
4500 return Build_Val (Hi);
4504 Low_Bound => Build_Val (Lo),
4505 High_Bound => Build_Val (Hi));
4506 Set_Etype (Result, Btyp);
4507 Set_Analyzed (Result);
4516 function Build_Val (V : Uint) return Node_Id is
4520 if Is_Enumeration_Type (Typ) then
4521 Result := Get_Enum_Lit_From_Pos (Typ, V, Loc);
4523 Result := Make_Integer_Literal (Loc, V);
4526 Set_Etype (Result, Btyp);
4527 Set_Is_Static_Expression (Result);
4528 Set_Analyzed (Result);
4536 function Get_RList (Exp : Node_Id) return RList is
4541 -- Static expression can only be true or false
4543 if Is_OK_Static_Expression (Exp) then
4547 if Expr_Value (Exp) = 0 then
4554 -- Otherwise test node type
4562 when N_Op_And | N_And_Then =>
4563 return Get_RList (Left_Opnd (Exp))
4565 Get_RList (Right_Opnd (Exp));
4569 when N_Op_Or | N_Or_Else =>
4570 return Get_RList (Left_Opnd (Exp))
4572 Get_RList (Right_Opnd (Exp));
4577 return not Get_RList (Right_Opnd (Exp));
4579 -- Comparisons of type with static value
4581 when N_Op_Compare =>
4582 -- Type is left operand
4584 if Is_Type_Ref (Left_Opnd (Exp))
4585 and then Is_OK_Static_Expression (Right_Opnd (Exp))
4587 Val := Expr_Value (Right_Opnd (Exp));
4589 -- Typ is right operand
4591 elsif Is_Type_Ref (Right_Opnd (Exp))
4592 and then Is_OK_Static_Expression (Left_Opnd (Exp))
4594 Val := Expr_Value (Left_Opnd (Exp));
4596 -- Invert sense of comparison
4599 when N_Op_Gt => Op := N_Op_Lt;
4600 when N_Op_Lt => Op := N_Op_Gt;
4601 when N_Op_Ge => Op := N_Op_Le;
4602 when N_Op_Le => Op := N_Op_Ge;
4603 when others => null;
4606 -- Other cases are non-static
4612 -- Construct range according to comparison operation
4616 return RList'(1 => REnt'(Val, Val));
4619 return RList'(1 => REnt'(Val, BHi));
4622 return RList'(1 => REnt'(Val + 1, BHi));
4625 return RList'(1 => REnt'(BLo, Val));
4628 return RList'(1 => REnt'(BLo, Val - 1));
4631 return RList'(REnt'(BLo, Val - 1),
4632 REnt'(Val + 1, BHi));
4635 raise Program_Error;
4641 if not Is_Type_Ref (Left_Opnd (Exp)) then
4645 if Present (Right_Opnd (Exp)) then
4646 return Membership_Entry (Right_Opnd (Exp));
4648 return Membership_Entries (First (Alternatives (Exp)));
4651 -- Negative membership (NOT IN)
4654 if not Is_Type_Ref (Left_Opnd (Exp)) then
4658 if Present (Right_Opnd (Exp)) then
4659 return not Membership_Entry (Right_Opnd (Exp));
4661 return not Membership_Entries (First (Alternatives (Exp)));
4664 -- Function call, may be call to static predicate
4666 when N_Function_Call =>
4667 if Is_Entity_Name (Name (Exp)) then
4669 Ent : constant Entity_Id := Entity (Name (Exp));
4671 if Has_Predicates (Ent) then
4672 return Stat_Pred (Etype (First_Formal (Ent)));
4677 -- Other function call cases are non-static
4681 -- Qualified expression, dig out the expression
4683 when N_Qualified_Expression =>
4684 return Get_RList (Expression (Exp));
4689 return (Get_RList (Left_Opnd (Exp))
4690 and not Get_RList (Right_Opnd (Exp)))
4691 or (Get_RList (Right_Opnd (Exp))
4692 and not Get_RList (Left_Opnd (Exp)));
4694 -- Any other node type is non-static
4705 function Hi_Val (N : Node_Id) return Uint is
4707 if Is_Static_Expression (N) then
4708 return Expr_Value (N);
4710 pragma Assert (Nkind (N) = N_Range);
4711 return Expr_Value (High_Bound (N));
4719 function Is_False (R : RList) return Boolean is
4721 return R'Length = 0;
4728 function Is_True (R : RList) return Boolean is
4731 and then R (R'First).Lo = BLo
4732 and then R (R'First).Hi = BHi;
4739 function Is_Type_Ref (N : Node_Id) return Boolean is
4741 return Nkind (N) = N_Identifier and then Chars (N) = Nam;
4748 function Lo_Val (N : Node_Id) return Uint is
4750 if Is_Static_Expression (N) then
4751 return Expr_Value (N);
4753 pragma Assert (Nkind (N) = N_Range);
4754 return Expr_Value (Low_Bound (N));
4758 ------------------------
4759 -- Membership_Entries --
4760 ------------------------
4762 function Membership_Entries (N : Node_Id) return RList is
4764 if No (Next (N)) then
4765 return Membership_Entry (N);
4767 return Membership_Entry (N) or Membership_Entries (Next (N));
4769 end Membership_Entries;
4771 ----------------------
4772 -- Membership_Entry --
4773 ----------------------
4775 function Membership_Entry (N : Node_Id) return RList is
4783 if Nkind (N) = N_Range then
4784 if not Is_Static_Expression (Low_Bound (N))
4786 not Is_Static_Expression (High_Bound (N))
4790 SLo := Expr_Value (Low_Bound (N));
4791 SHi := Expr_Value (High_Bound (N));
4792 return RList'(1 => REnt'(SLo, SHi));
4795 -- Static expression case
4797 elsif Is_Static_Expression (N) then
4798 Val := Expr_Value (N);
4799 return RList'(1 => REnt'(Val, Val));
4801 -- Identifier (other than static expression) case
4803 else pragma Assert (Nkind (N) = N_Identifier);
4807 if Is_Type (Entity (N)) then
4809 -- If type has predicates, process them
4811 if Has_Predicates (Entity (N)) then
4812 return Stat_Pred (Entity (N));
4814 -- For static subtype without predicates, get range
4816 elsif Is_Static_Subtype (Entity (N)) then
4817 SLo := Expr_Value (Type_Low_Bound (Entity (N)));
4818 SHi := Expr_Value (Type_High_Bound (Entity (N)));
4819 return RList'(1 => REnt'(SLo, SHi));
4821 -- Any other type makes us non-static
4827 -- Any other kind of identifier in predicate (e.g. a non-static
4828 -- expression value) means this is not a static predicate.
4834 end Membership_Entry;
4840 function Stat_Pred (Typ : Entity_Id) return RList is
4842 -- Not static if type does not have static predicates
4844 if not Has_Predicates (Typ)
4845 or else No (Static_Predicate (Typ))
4850 -- Otherwise we convert the predicate list to a range list
4853 Result : RList (1 .. List_Length (Static_Predicate (Typ)));
4857 P := First (Static_Predicate (Typ));
4858 for J in Result'Range loop
4859 Result (J) := REnt'(Lo_Val (P), Hi_Val (P));
4867 -- Start of processing for Build_Static_Predicate
4870 -- Now analyze the expression to see if it is a static predicate
4873 Ranges : constant RList := Get_RList (Expr);
4874 -- Range list from expression if it is static
4879 -- Convert range list into a form for the static predicate. In the
4880 -- Ranges array, we just have raw ranges, these must be converted
4881 -- to properly typed and analyzed static expressions or range nodes.
4883 -- Note: here we limit ranges to the ranges of the subtype, so that
4884 -- a predicate is always false for values outside the subtype. That
4885 -- seems fine, such values are invalid anyway, and considering them
4886 -- to fail the predicate seems allowed and friendly, and furthermore
4887 -- simplifies processing for case statements and loops.
4891 for J in Ranges'Range loop
4893 Lo : Uint := Ranges (J).Lo;
4894 Hi : Uint := Ranges (J).Hi;
4897 -- Ignore completely out of range entry
4899 if Hi < TLo or else Lo > THi then
4902 -- Otherwise process entry
4905 -- Adjust out of range value to subtype range
4915 -- Convert range into required form
4918 Append_To (Plist, Build_Val (Lo));
4920 Append_To (Plist, Build_Range (Lo, Hi));
4926 -- Processing was successful and all entries were static, so now we
4927 -- can store the result as the predicate list.
4929 Set_Static_Predicate (Typ, Plist);
4931 -- The processing for static predicates put the expression into
4932 -- canonical form as a series of ranges. It also eliminated
4933 -- duplicates and collapsed and combined ranges. We might as well
4934 -- replace the alternatives list of the right operand of the
4935 -- membership test with the static predicate list, which will
4936 -- usually be more efficient.
4939 New_Alts : constant List_Id := New_List;
4944 Old_Node := First (Plist);
4945 while Present (Old_Node) loop
4946 New_Node := New_Copy (Old_Node);
4948 if Nkind (New_Node) = N_Range then
4949 Set_Low_Bound (New_Node, New_Copy (Low_Bound (Old_Node)));
4950 Set_High_Bound (New_Node, New_Copy (High_Bound (Old_Node)));
4953 Append_To (New_Alts, New_Node);
4957 -- If empty list, replace by False
4959 if Is_Empty_List (New_Alts) then
4960 Rewrite (Expr, New_Occurrence_Of (Standard_False, Loc));
4962 -- Else replace by set membership test
4967 Left_Opnd => Make_Identifier (Loc, Nam),
4968 Right_Opnd => Empty,
4969 Alternatives => New_Alts));
4971 -- Resolve new expression in function context
4973 Install_Formals (Predicate_Function (Typ));
4974 Push_Scope (Predicate_Function (Typ));
4975 Analyze_And_Resolve (Expr, Standard_Boolean);
4981 -- If non-static, return doing nothing
4986 end Build_Static_Predicate;
4988 -----------------------------------------
4989 -- Check_Aspect_At_End_Of_Declarations --
4990 -----------------------------------------
4992 procedure Check_Aspect_At_End_Of_Declarations (ASN : Node_Id) is
4993 Ent : constant Entity_Id := Entity (ASN);
4994 Ident : constant Node_Id := Identifier (ASN);
4996 Freeze_Expr : constant Node_Id := Expression (ASN);
4997 -- Preanalyzed expression from call to Check_Aspect_At_Freeze_Point
4999 End_Decl_Expr : constant Node_Id := Entity (Ident);
5000 -- Expression to be analyzed at end of declarations
5002 T : constant Entity_Id := Etype (Freeze_Expr);
5003 -- Type required for preanalyze call
5005 A_Id : constant Aspect_Id := Get_Aspect_Id (Chars (Ident));
5008 -- Set False if error
5010 -- On entry to this procedure, Entity (Ident) contains a copy of the
5011 -- original expression from the aspect, saved for this purpose, and
5012 -- but Expression (Ident) is a preanalyzed copy of the expression,
5013 -- preanalyzed just after the freeze point.
5016 -- Case of stream attributes, just have to compare entities
5018 if A_Id = Aspect_Input or else
5019 A_Id = Aspect_Output or else
5020 A_Id = Aspect_Read or else
5023 Analyze (End_Decl_Expr);
5024 Err := Entity (End_Decl_Expr) /= Entity (Freeze_Expr);
5029 Preanalyze_Spec_Expression (End_Decl_Expr, T);
5030 Err := not Fully_Conformant_Expressions (End_Decl_Expr, Freeze_Expr);
5033 -- Output error message if error
5037 ("visibility of aspect for& changes after freeze point",
5040 ("?info: & is frozen here, aspects evaluated at this point",
5041 Freeze_Node (Ent), Ent);
5043 end Check_Aspect_At_End_Of_Declarations;
5045 ----------------------------------
5046 -- Check_Aspect_At_Freeze_Point --
5047 ----------------------------------
5049 procedure Check_Aspect_At_Freeze_Point (ASN : Node_Id) is
5050 Ident : constant Node_Id := Identifier (ASN);
5051 -- Identifier (use Entity field to save expression)
5054 -- Type required for preanalyze call
5056 A_Id : constant Aspect_Id := Get_Aspect_Id (Chars (Ident));
5059 -- On entry to this procedure, Entity (Ident) contains a copy of the
5060 -- original expression from the aspect, saved for this purpose.
5062 -- On exit from this procedure Entity (Ident) is unchanged, still
5063 -- containing that copy, but Expression (Ident) is a preanalyzed copy
5064 -- of the expression, preanalyzed just after the freeze point.
5066 -- Make a copy of the expression to be preanalyed
5068 Set_Expression (ASN, New_Copy_Tree (Entity (Ident)));
5070 -- Find type for preanalyze call
5074 -- No_Aspect should be impossible
5077 raise Program_Error;
5079 -- Aspects taking an optional boolean argument. Note that we will
5080 -- never be called with an empty expression, because such aspects
5081 -- never need to be delayed anyway.
5083 when Boolean_Aspects =>
5084 pragma Assert (Present (Expression (ASN)));
5085 T := Standard_Boolean;
5087 -- Aspects corresponding to attribute definition clauses
5089 when Aspect_Address =>
5090 T := RTE (RE_Address);
5092 when Aspect_Bit_Order =>
5093 T := RTE (RE_Bit_Order);
5095 when Aspect_External_Tag =>
5096 T := Standard_String;
5098 when Aspect_Storage_Pool =>
5099 T := Class_Wide_Type (RTE (RE_Root_Storage_Pool));
5103 Aspect_Component_Size |
5104 Aspect_Machine_Radix |
5105 Aspect_Object_Size |
5107 Aspect_Storage_Size |
5108 Aspect_Stream_Size |
5109 Aspect_Value_Size =>
5112 -- Stream attribute. Special case, the expression is just an entity
5113 -- that does not need any resolution, so just analyze.
5119 Analyze (Expression (ASN));
5122 -- Suppress/Unsupress/Warnings should never be delayed
5124 when Aspect_Suppress |
5127 raise Program_Error;
5129 -- Pre/Post/Invariant/Predicate take boolean expressions
5131 when Aspect_Dynamic_Predicate |
5136 Aspect_Static_Predicate =>
5137 T := Standard_Boolean;
5140 -- Do the preanalyze call
5142 Preanalyze_Spec_Expression (Expression (ASN), T);
5143 end Check_Aspect_At_Freeze_Point;
5145 -----------------------------------
5146 -- Check_Constant_Address_Clause --
5147 -----------------------------------
5149 procedure Check_Constant_Address_Clause
5153 procedure Check_At_Constant_Address (Nod : Node_Id);
5154 -- Checks that the given node N represents a name whose 'Address is
5155 -- constant (in the same sense as OK_Constant_Address_Clause, i.e. the
5156 -- address value is the same at the point of declaration of U_Ent and at
5157 -- the time of elaboration of the address clause.
5159 procedure Check_Expr_Constants (Nod : Node_Id);
5160 -- Checks that Nod meets the requirements for a constant address clause
5161 -- in the sense of the enclosing procedure.
5163 procedure Check_List_Constants (Lst : List_Id);
5164 -- Check that all elements of list Lst meet the requirements for a
5165 -- constant address clause in the sense of the enclosing procedure.
5167 -------------------------------
5168 -- Check_At_Constant_Address --
5169 -------------------------------
5171 procedure Check_At_Constant_Address (Nod : Node_Id) is
5173 if Is_Entity_Name (Nod) then
5174 if Present (Address_Clause (Entity ((Nod)))) then
5176 ("invalid address clause for initialized object &!",
5179 ("address for& cannot" &
5180 " depend on another address clause! (RM 13.1(22))!",
5183 elsif In_Same_Source_Unit (Entity (Nod), U_Ent)
5184 and then Sloc (U_Ent) < Sloc (Entity (Nod))
5187 ("invalid address clause for initialized object &!",
5189 Error_Msg_Node_2 := U_Ent;
5191 ("\& must be defined before & (RM 13.1(22))!",
5195 elsif Nkind (Nod) = N_Selected_Component then
5197 T : constant Entity_Id := Etype (Prefix (Nod));
5200 if (Is_Record_Type (T)
5201 and then Has_Discriminants (T))
5204 and then Is_Record_Type (Designated_Type (T))
5205 and then Has_Discriminants (Designated_Type (T)))
5208 ("invalid address clause for initialized object &!",
5211 ("\address cannot depend on component" &
5212 " of discriminated record (RM 13.1(22))!",
5215 Check_At_Constant_Address (Prefix (Nod));
5219 elsif Nkind (Nod) = N_Indexed_Component then
5220 Check_At_Constant_Address (Prefix (Nod));
5221 Check_List_Constants (Expressions (Nod));
5224 Check_Expr_Constants (Nod);
5226 end Check_At_Constant_Address;
5228 --------------------------
5229 -- Check_Expr_Constants --
5230 --------------------------
5232 procedure Check_Expr_Constants (Nod : Node_Id) is
5233 Loc_U_Ent : constant Source_Ptr := Sloc (U_Ent);
5234 Ent : Entity_Id := Empty;
5237 if Nkind (Nod) in N_Has_Etype
5238 and then Etype (Nod) = Any_Type
5244 when N_Empty | N_Error =>
5247 when N_Identifier | N_Expanded_Name =>
5248 Ent := Entity (Nod);
5250 -- We need to look at the original node if it is different
5251 -- from the node, since we may have rewritten things and
5252 -- substituted an identifier representing the rewrite.
5254 if Original_Node (Nod) /= Nod then
5255 Check_Expr_Constants (Original_Node (Nod));
5257 -- If the node is an object declaration without initial
5258 -- value, some code has been expanded, and the expression
5259 -- is not constant, even if the constituents might be
5260 -- acceptable, as in A'Address + offset.
5262 if Ekind (Ent) = E_Variable
5264 Nkind (Declaration_Node (Ent)) = N_Object_Declaration
5266 No (Expression (Declaration_Node (Ent)))
5269 ("invalid address clause for initialized object &!",
5272 -- If entity is constant, it may be the result of expanding
5273 -- a check. We must verify that its declaration appears
5274 -- before the object in question, else we also reject the
5277 elsif Ekind (Ent) = E_Constant
5278 and then In_Same_Source_Unit (Ent, U_Ent)
5279 and then Sloc (Ent) > Loc_U_Ent
5282 ("invalid address clause for initialized object &!",
5289 -- Otherwise look at the identifier and see if it is OK
5291 if Ekind_In (Ent, E_Named_Integer, E_Named_Real)
5292 or else Is_Type (Ent)
5297 Ekind (Ent) = E_Constant
5299 Ekind (Ent) = E_In_Parameter
5301 -- This is the case where we must have Ent defined before
5302 -- U_Ent. Clearly if they are in different units this
5303 -- requirement is met since the unit containing Ent is
5304 -- already processed.
5306 if not In_Same_Source_Unit (Ent, U_Ent) then
5309 -- Otherwise location of Ent must be before the location
5310 -- of U_Ent, that's what prior defined means.
5312 elsif Sloc (Ent) < Loc_U_Ent then
5317 ("invalid address clause for initialized object &!",
5319 Error_Msg_Node_2 := U_Ent;
5321 ("\& must be defined before & (RM 13.1(22))!",
5325 elsif Nkind (Original_Node (Nod)) = N_Function_Call then
5326 Check_Expr_Constants (Original_Node (Nod));
5330 ("invalid address clause for initialized object &!",
5333 if Comes_From_Source (Ent) then
5335 ("\reference to variable& not allowed"
5336 & " (RM 13.1(22))!", Nod, Ent);
5339 ("non-static expression not allowed"
5340 & " (RM 13.1(22))!", Nod);
5344 when N_Integer_Literal =>
5346 -- If this is a rewritten unchecked conversion, in a system
5347 -- where Address is an integer type, always use the base type
5348 -- for a literal value. This is user-friendly and prevents
5349 -- order-of-elaboration issues with instances of unchecked
5352 if Nkind (Original_Node (Nod)) = N_Function_Call then
5353 Set_Etype (Nod, Base_Type (Etype (Nod)));
5356 when N_Real_Literal |
5358 N_Character_Literal =>
5362 Check_Expr_Constants (Low_Bound (Nod));
5363 Check_Expr_Constants (High_Bound (Nod));
5365 when N_Explicit_Dereference =>
5366 Check_Expr_Constants (Prefix (Nod));
5368 when N_Indexed_Component =>
5369 Check_Expr_Constants (Prefix (Nod));
5370 Check_List_Constants (Expressions (Nod));
5373 Check_Expr_Constants (Prefix (Nod));
5374 Check_Expr_Constants (Discrete_Range (Nod));
5376 when N_Selected_Component =>
5377 Check_Expr_Constants (Prefix (Nod));
5379 when N_Attribute_Reference =>
5380 if Attribute_Name (Nod) = Name_Address
5382 Attribute_Name (Nod) = Name_Access
5384 Attribute_Name (Nod) = Name_Unchecked_Access
5386 Attribute_Name (Nod) = Name_Unrestricted_Access
5388 Check_At_Constant_Address (Prefix (Nod));
5391 Check_Expr_Constants (Prefix (Nod));
5392 Check_List_Constants (Expressions (Nod));
5396 Check_List_Constants (Component_Associations (Nod));
5397 Check_List_Constants (Expressions (Nod));
5399 when N_Component_Association =>
5400 Check_Expr_Constants (Expression (Nod));
5402 when N_Extension_Aggregate =>
5403 Check_Expr_Constants (Ancestor_Part (Nod));
5404 Check_List_Constants (Component_Associations (Nod));
5405 Check_List_Constants (Expressions (Nod));
5410 when N_Binary_Op | N_Short_Circuit | N_Membership_Test =>
5411 Check_Expr_Constants (Left_Opnd (Nod));
5412 Check_Expr_Constants (Right_Opnd (Nod));
5415 Check_Expr_Constants (Right_Opnd (Nod));
5417 when N_Type_Conversion |
5418 N_Qualified_Expression |
5420 Check_Expr_Constants (Expression (Nod));
5422 when N_Unchecked_Type_Conversion =>
5423 Check_Expr_Constants (Expression (Nod));
5425 -- If this is a rewritten unchecked conversion, subtypes in
5426 -- this node are those created within the instance. To avoid
5427 -- order of elaboration issues, replace them with their base
5428 -- types. Note that address clauses can cause order of
5429 -- elaboration problems because they are elaborated by the
5430 -- back-end at the point of definition, and may mention
5431 -- entities declared in between (as long as everything is
5432 -- static). It is user-friendly to allow unchecked conversions
5435 if Nkind (Original_Node (Nod)) = N_Function_Call then
5436 Set_Etype (Expression (Nod),
5437 Base_Type (Etype (Expression (Nod))));
5438 Set_Etype (Nod, Base_Type (Etype (Nod)));
5441 when N_Function_Call =>
5442 if not Is_Pure (Entity (Name (Nod))) then
5444 ("invalid address clause for initialized object &!",
5448 ("\function & is not pure (RM 13.1(22))!",
5449 Nod, Entity (Name (Nod)));
5452 Check_List_Constants (Parameter_Associations (Nod));
5455 when N_Parameter_Association =>
5456 Check_Expr_Constants (Explicit_Actual_Parameter (Nod));
5460 ("invalid address clause for initialized object &!",
5463 ("\must be constant defined before& (RM 13.1(22))!",
5466 end Check_Expr_Constants;
5468 --------------------------
5469 -- Check_List_Constants --
5470 --------------------------
5472 procedure Check_List_Constants (Lst : List_Id) is
5476 if Present (Lst) then
5477 Nod1 := First (Lst);
5478 while Present (Nod1) loop
5479 Check_Expr_Constants (Nod1);
5483 end Check_List_Constants;
5485 -- Start of processing for Check_Constant_Address_Clause
5488 -- If rep_clauses are to be ignored, no need for legality checks. In
5489 -- particular, no need to pester user about rep clauses that violate
5490 -- the rule on constant addresses, given that these clauses will be
5491 -- removed by Freeze before they reach the back end.
5493 if not Ignore_Rep_Clauses then
5494 Check_Expr_Constants (Expr);
5496 end Check_Constant_Address_Clause;
5498 ----------------------------------------
5499 -- Check_Record_Representation_Clause --
5500 ----------------------------------------
5502 procedure Check_Record_Representation_Clause (N : Node_Id) is
5503 Loc : constant Source_Ptr := Sloc (N);
5504 Ident : constant Node_Id := Identifier (N);
5505 Rectype : Entity_Id;
5510 Hbit : Uint := Uint_0;
5514 Max_Bit_So_Far : Uint;
5515 -- Records the maximum bit position so far. If all field positions
5516 -- are monotonically increasing, then we can skip the circuit for
5517 -- checking for overlap, since no overlap is possible.
5519 Tagged_Parent : Entity_Id := Empty;
5520 -- This is set in the case of a derived tagged type for which we have
5521 -- Is_Fully_Repped_Tagged_Type True (indicating that all components are
5522 -- positioned by record representation clauses). In this case we must
5523 -- check for overlap between components of this tagged type, and the
5524 -- components of its parent. Tagged_Parent will point to this parent
5525 -- type. For all other cases Tagged_Parent is left set to Empty.
5527 Parent_Last_Bit : Uint;
5528 -- Relevant only if Tagged_Parent is set, Parent_Last_Bit indicates the
5529 -- last bit position for any field in the parent type. We only need to
5530 -- check overlap for fields starting below this point.
5532 Overlap_Check_Required : Boolean;
5533 -- Used to keep track of whether or not an overlap check is required
5535 Overlap_Detected : Boolean := False;
5536 -- Set True if an overlap is detected
5538 Ccount : Natural := 0;
5539 -- Number of component clauses in record rep clause
5541 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id);
5542 -- Given two entities for record components or discriminants, checks
5543 -- if they have overlapping component clauses and issues errors if so.
5545 procedure Find_Component;
5546 -- Finds component entity corresponding to current component clause (in
5547 -- CC), and sets Comp to the entity, and Fbit/Lbit to the zero origin
5548 -- start/stop bits for the field. If there is no matching component or
5549 -- if the matching component does not have a component clause, then
5550 -- that's an error and Comp is set to Empty, but no error message is
5551 -- issued, since the message was already given. Comp is also set to
5552 -- Empty if the current "component clause" is in fact a pragma.
5554 -----------------------------
5555 -- Check_Component_Overlap --
5556 -----------------------------
5558 procedure Check_Component_Overlap (C1_Ent, C2_Ent : Entity_Id) is
5559 CC1 : constant Node_Id := Component_Clause (C1_Ent);
5560 CC2 : constant Node_Id := Component_Clause (C2_Ent);
5563 if Present (CC1) and then Present (CC2) then
5565 -- Exclude odd case where we have two tag fields in the same
5566 -- record, both at location zero. This seems a bit strange, but
5567 -- it seems to happen in some circumstances, perhaps on an error.
5569 if Chars (C1_Ent) = Name_uTag
5571 Chars (C2_Ent) = Name_uTag
5576 -- Here we check if the two fields overlap
5579 S1 : constant Uint := Component_Bit_Offset (C1_Ent);
5580 S2 : constant Uint := Component_Bit_Offset (C2_Ent);
5581 E1 : constant Uint := S1 + Esize (C1_Ent);
5582 E2 : constant Uint := S2 + Esize (C2_Ent);
5585 if E2 <= S1 or else E1 <= S2 then
5588 Error_Msg_Node_2 := Component_Name (CC2);
5589 Error_Msg_Sloc := Sloc (Error_Msg_Node_2);
5590 Error_Msg_Node_1 := Component_Name (CC1);
5592 ("component& overlaps & #", Component_Name (CC1));
5593 Overlap_Detected := True;
5597 end Check_Component_Overlap;
5599 --------------------
5600 -- Find_Component --
5601 --------------------
5603 procedure Find_Component is
5605 procedure Search_Component (R : Entity_Id);
5606 -- Search components of R for a match. If found, Comp is set.
5608 ----------------------
5609 -- Search_Component --
5610 ----------------------
5612 procedure Search_Component (R : Entity_Id) is
5614 Comp := First_Component_Or_Discriminant (R);
5615 while Present (Comp) loop
5617 -- Ignore error of attribute name for component name (we
5618 -- already gave an error message for this, so no need to
5621 if Nkind (Component_Name (CC)) = N_Attribute_Reference then
5624 exit when Chars (Comp) = Chars (Component_Name (CC));
5627 Next_Component_Or_Discriminant (Comp);
5629 end Search_Component;
5631 -- Start of processing for Find_Component
5634 -- Return with Comp set to Empty if we have a pragma
5636 if Nkind (CC) = N_Pragma then
5641 -- Search current record for matching component
5643 Search_Component (Rectype);
5645 -- If not found, maybe component of base type that is absent from
5646 -- statically constrained first subtype.
5649 Search_Component (Base_Type (Rectype));
5652 -- If no component, or the component does not reference the component
5653 -- clause in question, then there was some previous error for which
5654 -- we already gave a message, so just return with Comp Empty.
5657 or else Component_Clause (Comp) /= CC
5661 -- Normal case where we have a component clause
5664 Fbit := Component_Bit_Offset (Comp);
5665 Lbit := Fbit + Esize (Comp) - 1;
5669 -- Start of processing for Check_Record_Representation_Clause
5673 Rectype := Entity (Ident);
5675 if Rectype = Any_Type then
5678 Rectype := Underlying_Type (Rectype);
5681 -- See if we have a fully repped derived tagged type
5684 PS : constant Entity_Id := Parent_Subtype (Rectype);
5687 if Present (PS) and then Is_Fully_Repped_Tagged_Type (PS) then
5688 Tagged_Parent := PS;
5690 -- Find maximum bit of any component of the parent type
5692 Parent_Last_Bit := UI_From_Int (System_Address_Size - 1);
5693 Pcomp := First_Entity (Tagged_Parent);
5694 while Present (Pcomp) loop
5695 if Ekind_In (Pcomp, E_Discriminant, E_Component) then
5696 if Component_Bit_Offset (Pcomp) /= No_Uint
5697 and then Known_Static_Esize (Pcomp)
5702 Component_Bit_Offset (Pcomp) + Esize (Pcomp) - 1);
5705 Next_Entity (Pcomp);
5711 -- All done if no component clauses
5713 CC := First (Component_Clauses (N));
5719 -- If a tag is present, then create a component clause that places it
5720 -- at the start of the record (otherwise gigi may place it after other
5721 -- fields that have rep clauses).
5723 Fent := First_Entity (Rectype);
5725 if Nkind (Fent) = N_Defining_Identifier
5726 and then Chars (Fent) = Name_uTag
5728 Set_Component_Bit_Offset (Fent, Uint_0);
5729 Set_Normalized_Position (Fent, Uint_0);
5730 Set_Normalized_First_Bit (Fent, Uint_0);
5731 Set_Normalized_Position_Max (Fent, Uint_0);
5732 Init_Esize (Fent, System_Address_Size);
5734 Set_Component_Clause (Fent,
5735 Make_Component_Clause (Loc,
5736 Component_Name => Make_Identifier (Loc, Name_uTag),
5738 Position => Make_Integer_Literal (Loc, Uint_0),
5739 First_Bit => Make_Integer_Literal (Loc, Uint_0),
5741 Make_Integer_Literal (Loc,
5742 UI_From_Int (System_Address_Size))));
5744 Ccount := Ccount + 1;
5747 Max_Bit_So_Far := Uint_Minus_1;
5748 Overlap_Check_Required := False;
5750 -- Process the component clauses
5752 while Present (CC) loop
5755 if Present (Comp) then
5756 Ccount := Ccount + 1;
5758 -- We need a full overlap check if record positions non-monotonic
5760 if Fbit <= Max_Bit_So_Far then
5761 Overlap_Check_Required := True;
5764 Max_Bit_So_Far := Lbit;
5766 -- Check bit position out of range of specified size
5768 if Has_Size_Clause (Rectype)
5769 and then Esize (Rectype) <= Lbit
5772 ("bit number out of range of specified size",
5775 -- Check for overlap with tag field
5778 if Is_Tagged_Type (Rectype)
5779 and then Fbit < System_Address_Size
5782 ("component overlaps tag field of&",
5783 Component_Name (CC), Rectype);
5784 Overlap_Detected := True;
5792 -- Check parent overlap if component might overlap parent field
5794 if Present (Tagged_Parent)
5795 and then Fbit <= Parent_Last_Bit
5797 Pcomp := First_Component_Or_Discriminant (Tagged_Parent);
5798 while Present (Pcomp) loop
5799 if not Is_Tag (Pcomp)
5800 and then Chars (Pcomp) /= Name_uParent
5802 Check_Component_Overlap (Comp, Pcomp);
5805 Next_Component_Or_Discriminant (Pcomp);
5813 -- Now that we have processed all the component clauses, check for
5814 -- overlap. We have to leave this till last, since the components can
5815 -- appear in any arbitrary order in the representation clause.
5817 -- We do not need this check if all specified ranges were monotonic,
5818 -- as recorded by Overlap_Check_Required being False at this stage.
5820 -- This first section checks if there are any overlapping entries at
5821 -- all. It does this by sorting all entries and then seeing if there are
5822 -- any overlaps. If there are none, then that is decisive, but if there
5823 -- are overlaps, they may still be OK (they may result from fields in
5824 -- different variants).
5826 if Overlap_Check_Required then
5827 Overlap_Check1 : declare
5829 OC_Fbit : array (0 .. Ccount) of Uint;
5830 -- First-bit values for component clauses, the value is the offset
5831 -- of the first bit of the field from start of record. The zero
5832 -- entry is for use in sorting.
5834 OC_Lbit : array (0 .. Ccount) of Uint;
5835 -- Last-bit values for component clauses, the value is the offset
5836 -- of the last bit of the field from start of record. The zero
5837 -- entry is for use in sorting.
5839 OC_Count : Natural := 0;
5840 -- Count of entries in OC_Fbit and OC_Lbit
5842 function OC_Lt (Op1, Op2 : Natural) return Boolean;
5843 -- Compare routine for Sort
5845 procedure OC_Move (From : Natural; To : Natural);
5846 -- Move routine for Sort
5848 package Sorting is new GNAT.Heap_Sort_G (OC_Move, OC_Lt);
5854 function OC_Lt (Op1, Op2 : Natural) return Boolean is
5856 return OC_Fbit (Op1) < OC_Fbit (Op2);
5863 procedure OC_Move (From : Natural; To : Natural) is
5865 OC_Fbit (To) := OC_Fbit (From);
5866 OC_Lbit (To) := OC_Lbit (From);
5869 -- Start of processing for Overlap_Check
5872 CC := First (Component_Clauses (N));
5873 while Present (CC) loop
5875 -- Exclude component clause already marked in error
5877 if not Error_Posted (CC) then
5880 if Present (Comp) then
5881 OC_Count := OC_Count + 1;
5882 OC_Fbit (OC_Count) := Fbit;
5883 OC_Lbit (OC_Count) := Lbit;
5890 Sorting.Sort (OC_Count);
5892 Overlap_Check_Required := False;
5893 for J in 1 .. OC_Count - 1 loop
5894 if OC_Lbit (J) >= OC_Fbit (J + 1) then
5895 Overlap_Check_Required := True;
5902 -- If Overlap_Check_Required is still True, then we have to do the full
5903 -- scale overlap check, since we have at least two fields that do
5904 -- overlap, and we need to know if that is OK since they are in
5905 -- different variant, or whether we have a definite problem.
5907 if Overlap_Check_Required then
5908 Overlap_Check2 : declare
5909 C1_Ent, C2_Ent : Entity_Id;
5910 -- Entities of components being checked for overlap
5913 -- Component_List node whose Component_Items are being checked
5916 -- Component declaration for component being checked
5919 C1_Ent := First_Entity (Base_Type (Rectype));
5921 -- Loop through all components in record. For each component check
5922 -- for overlap with any of the preceding elements on the component
5923 -- list containing the component and also, if the component is in
5924 -- a variant, check against components outside the case structure.
5925 -- This latter test is repeated recursively up the variant tree.
5927 Main_Component_Loop : while Present (C1_Ent) loop
5928 if not Ekind_In (C1_Ent, E_Component, E_Discriminant) then
5929 goto Continue_Main_Component_Loop;
5932 -- Skip overlap check if entity has no declaration node. This
5933 -- happens with discriminants in constrained derived types.
5934 -- Possibly we are missing some checks as a result, but that
5935 -- does not seem terribly serious.
5937 if No (Declaration_Node (C1_Ent)) then
5938 goto Continue_Main_Component_Loop;
5941 Clist := Parent (List_Containing (Declaration_Node (C1_Ent)));
5943 -- Loop through component lists that need checking. Check the
5944 -- current component list and all lists in variants above us.
5946 Component_List_Loop : loop
5948 -- If derived type definition, go to full declaration
5949 -- If at outer level, check discriminants if there are any.
5951 if Nkind (Clist) = N_Derived_Type_Definition then
5952 Clist := Parent (Clist);
5955 -- Outer level of record definition, check discriminants
5957 if Nkind_In (Clist, N_Full_Type_Declaration,
5958 N_Private_Type_Declaration)
5960 if Has_Discriminants (Defining_Identifier (Clist)) then
5962 First_Discriminant (Defining_Identifier (Clist));
5963 while Present (C2_Ent) loop
5964 exit when C1_Ent = C2_Ent;
5965 Check_Component_Overlap (C1_Ent, C2_Ent);
5966 Next_Discriminant (C2_Ent);
5970 -- Record extension case
5972 elsif Nkind (Clist) = N_Derived_Type_Definition then
5975 -- Otherwise check one component list
5978 Citem := First (Component_Items (Clist));
5979 while Present (Citem) loop
5980 if Nkind (Citem) = N_Component_Declaration then
5981 C2_Ent := Defining_Identifier (Citem);
5982 exit when C1_Ent = C2_Ent;
5983 Check_Component_Overlap (C1_Ent, C2_Ent);
5990 -- Check for variants above us (the parent of the Clist can
5991 -- be a variant, in which case its parent is a variant part,
5992 -- and the parent of the variant part is a component list
5993 -- whose components must all be checked against the current
5994 -- component for overlap).
5996 if Nkind (Parent (Clist)) = N_Variant then
5997 Clist := Parent (Parent (Parent (Clist)));
5999 -- Check for possible discriminant part in record, this
6000 -- is treated essentially as another level in the
6001 -- recursion. For this case the parent of the component
6002 -- list is the record definition, and its parent is the
6003 -- full type declaration containing the discriminant
6006 elsif Nkind (Parent (Clist)) = N_Record_Definition then
6007 Clist := Parent (Parent ((Clist)));
6009 -- If neither of these two cases, we are at the top of
6013 exit Component_List_Loop;
6015 end loop Component_List_Loop;
6017 <<Continue_Main_Component_Loop>>
6018 Next_Entity (C1_Ent);
6020 end loop Main_Component_Loop;
6024 -- The following circuit deals with warning on record holes (gaps). We
6025 -- skip this check if overlap was detected, since it makes sense for the
6026 -- programmer to fix this illegality before worrying about warnings.
6028 if not Overlap_Detected and Warn_On_Record_Holes then
6029 Record_Hole_Check : declare
6030 Decl : constant Node_Id := Declaration_Node (Base_Type (Rectype));
6031 -- Full declaration of record type
6033 procedure Check_Component_List
6037 -- Check component list CL for holes. The starting bit should be
6038 -- Sbit. which is zero for the main record component list and set
6039 -- appropriately for recursive calls for variants. DS is set to
6040 -- a list of discriminant specifications to be included in the
6041 -- consideration of components. It is No_List if none to consider.
6043 --------------------------
6044 -- Check_Component_List --
6045 --------------------------
6047 procedure Check_Component_List
6055 Compl := Integer (List_Length (Component_Items (CL)));
6057 if DS /= No_List then
6058 Compl := Compl + Integer (List_Length (DS));
6062 Comps : array (Natural range 0 .. Compl) of Entity_Id;
6063 -- Gather components (zero entry is for sort routine)
6065 Ncomps : Natural := 0;
6066 -- Number of entries stored in Comps (starting at Comps (1))
6069 -- One component item or discriminant specification
6072 -- Starting bit for next component
6080 function Lt (Op1, Op2 : Natural) return Boolean;
6081 -- Compare routine for Sort
6083 procedure Move (From : Natural; To : Natural);
6084 -- Move routine for Sort
6086 package Sorting is new GNAT.Heap_Sort_G (Move, Lt);
6092 function Lt (Op1, Op2 : Natural) return Boolean is
6094 return Component_Bit_Offset (Comps (Op1))
6096 Component_Bit_Offset (Comps (Op2));
6103 procedure Move (From : Natural; To : Natural) is
6105 Comps (To) := Comps (From);
6109 -- Gather discriminants into Comp
6111 if DS /= No_List then
6112 Citem := First (DS);
6113 while Present (Citem) loop
6114 if Nkind (Citem) = N_Discriminant_Specification then
6116 Ent : constant Entity_Id :=
6117 Defining_Identifier (Citem);
6119 if Ekind (Ent) = E_Discriminant then
6120 Ncomps := Ncomps + 1;
6121 Comps (Ncomps) := Ent;
6130 -- Gather component entities into Comp
6132 Citem := First (Component_Items (CL));
6133 while Present (Citem) loop
6134 if Nkind (Citem) = N_Component_Declaration then
6135 Ncomps := Ncomps + 1;
6136 Comps (Ncomps) := Defining_Identifier (Citem);
6142 -- Now sort the component entities based on the first bit.
6143 -- Note we already know there are no overlapping components.
6145 Sorting.Sort (Ncomps);
6147 -- Loop through entries checking for holes
6150 for J in 1 .. Ncomps loop
6152 Error_Msg_Uint_1 := Component_Bit_Offset (CEnt) - Nbit;
6154 if Error_Msg_Uint_1 > 0 then
6156 ("?^-bit gap before component&",
6157 Component_Name (Component_Clause (CEnt)), CEnt);
6160 Nbit := Component_Bit_Offset (CEnt) + Esize (CEnt);
6163 -- Process variant parts recursively if present
6165 if Present (Variant_Part (CL)) then
6166 Variant := First (Variants (Variant_Part (CL)));
6167 while Present (Variant) loop
6168 Check_Component_List
6169 (Component_List (Variant), Nbit, No_List);
6174 end Check_Component_List;
6176 -- Start of processing for Record_Hole_Check
6183 if Is_Tagged_Type (Rectype) then
6184 Sbit := UI_From_Int (System_Address_Size);
6189 if Nkind (Decl) = N_Full_Type_Declaration
6190 and then Nkind (Type_Definition (Decl)) = N_Record_Definition
6192 Check_Component_List
6193 (Component_List (Type_Definition (Decl)),
6195 Discriminant_Specifications (Decl));
6198 end Record_Hole_Check;
6201 -- For records that have component clauses for all components, and whose
6202 -- size is less than or equal to 32, we need to know the size in the
6203 -- front end to activate possible packed array processing where the
6204 -- component type is a record.
6206 -- At this stage Hbit + 1 represents the first unused bit from all the
6207 -- component clauses processed, so if the component clauses are
6208 -- complete, then this is the length of the record.
6210 -- For records longer than System.Storage_Unit, and for those where not
6211 -- all components have component clauses, the back end determines the
6212 -- length (it may for example be appropriate to round up the size
6213 -- to some convenient boundary, based on alignment considerations, etc).
6215 if Unknown_RM_Size (Rectype) and then Hbit + 1 <= 32 then
6217 -- Nothing to do if at least one component has no component clause
6219 Comp := First_Component_Or_Discriminant (Rectype);
6220 while Present (Comp) loop
6221 exit when No (Component_Clause (Comp));
6222 Next_Component_Or_Discriminant (Comp);
6225 -- If we fall out of loop, all components have component clauses
6226 -- and so we can set the size to the maximum value.
6229 Set_RM_Size (Rectype, Hbit + 1);
6232 end Check_Record_Representation_Clause;
6238 procedure Check_Size
6242 Biased : out Boolean)
6244 UT : constant Entity_Id := Underlying_Type (T);
6250 -- Dismiss cases for generic types or types with previous errors
6253 or else UT = Any_Type
6254 or else Is_Generic_Type (UT)
6255 or else Is_Generic_Type (Root_Type (UT))
6259 -- Check case of bit packed array
6261 elsif Is_Array_Type (UT)
6262 and then Known_Static_Component_Size (UT)
6263 and then Is_Bit_Packed_Array (UT)
6271 Asiz := Component_Size (UT);
6272 Indx := First_Index (UT);
6274 Ityp := Etype (Indx);
6276 -- If non-static bound, then we are not in the business of
6277 -- trying to check the length, and indeed an error will be
6278 -- issued elsewhere, since sizes of non-static array types
6279 -- cannot be set implicitly or explicitly.
6281 if not Is_Static_Subtype (Ityp) then
6285 -- Otherwise accumulate next dimension
6287 Asiz := Asiz * (Expr_Value (Type_High_Bound (Ityp)) -
6288 Expr_Value (Type_Low_Bound (Ityp)) +
6292 exit when No (Indx);
6298 Error_Msg_Uint_1 := Asiz;
6300 ("size for& too small, minimum allowed is ^", N, T);
6301 Set_Esize (T, Asiz);
6302 Set_RM_Size (T, Asiz);
6306 -- All other composite types are ignored
6308 elsif Is_Composite_Type (UT) then
6311 -- For fixed-point types, don't check minimum if type is not frozen,
6312 -- since we don't know all the characteristics of the type that can
6313 -- affect the size (e.g. a specified small) till freeze time.
6315 elsif Is_Fixed_Point_Type (UT)
6316 and then not Is_Frozen (UT)
6320 -- Cases for which a minimum check is required
6323 -- Ignore if specified size is correct for the type
6325 if Known_Esize (UT) and then Siz = Esize (UT) then
6329 -- Otherwise get minimum size
6331 M := UI_From_Int (Minimum_Size (UT));
6335 -- Size is less than minimum size, but one possibility remains
6336 -- that we can manage with the new size if we bias the type.
6338 M := UI_From_Int (Minimum_Size (UT, Biased => True));
6341 Error_Msg_Uint_1 := M;
6343 ("size for& too small, minimum allowed is ^", N, T);
6353 -------------------------
6354 -- Get_Alignment_Value --
6355 -------------------------
6357 function Get_Alignment_Value (Expr : Node_Id) return Uint is
6358 Align : constant Uint := Static_Integer (Expr);
6361 if Align = No_Uint then
6364 elsif Align <= 0 then
6365 Error_Msg_N ("alignment value must be positive", Expr);
6369 for J in Int range 0 .. 64 loop
6371 M : constant Uint := Uint_2 ** J;
6374 exit when M = Align;
6378 ("alignment value must be power of 2", Expr);
6386 end Get_Alignment_Value;
6392 procedure Initialize is
6394 Address_Clause_Checks.Init;
6395 Independence_Checks.Init;
6396 Unchecked_Conversions.Init;
6399 -------------------------
6400 -- Is_Operational_Item --
6401 -------------------------
6403 function Is_Operational_Item (N : Node_Id) return Boolean is
6405 if Nkind (N) /= N_Attribute_Definition_Clause then
6409 Id : constant Attribute_Id := Get_Attribute_Id (Chars (N));
6411 return Id = Attribute_Input
6412 or else Id = Attribute_Output
6413 or else Id = Attribute_Read
6414 or else Id = Attribute_Write
6415 or else Id = Attribute_External_Tag;
6418 end Is_Operational_Item;
6424 function Minimum_Size
6426 Biased : Boolean := False) return Nat
6428 Lo : Uint := No_Uint;
6429 Hi : Uint := No_Uint;
6430 LoR : Ureal := No_Ureal;
6431 HiR : Ureal := No_Ureal;
6432 LoSet : Boolean := False;
6433 HiSet : Boolean := False;
6437 R_Typ : constant Entity_Id := Root_Type (T);
6440 -- If bad type, return 0
6442 if T = Any_Type then
6445 -- For generic types, just return zero. There cannot be any legitimate
6446 -- need to know such a size, but this routine may be called with a
6447 -- generic type as part of normal processing.
6449 elsif Is_Generic_Type (R_Typ)
6450 or else R_Typ = Any_Type
6454 -- Access types. Normally an access type cannot have a size smaller
6455 -- than the size of System.Address. The exception is on VMS, where
6456 -- we have short and long addresses, and it is possible for an access
6457 -- type to have a short address size (and thus be less than the size
6458 -- of System.Address itself). We simply skip the check for VMS, and
6459 -- leave it to the back end to do the check.
6461 elsif Is_Access_Type (T) then
6462 if OpenVMS_On_Target then
6465 return System_Address_Size;
6468 -- Floating-point types
6470 elsif Is_Floating_Point_Type (T) then
6471 return UI_To_Int (Esize (R_Typ));
6475 elsif Is_Discrete_Type (T) then
6477 -- The following loop is looking for the nearest compile time known
6478 -- bounds following the ancestor subtype chain. The idea is to find
6479 -- the most restrictive known bounds information.
6483 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
6488 if Compile_Time_Known_Value (Type_Low_Bound (Ancest)) then
6489 Lo := Expr_Rep_Value (Type_Low_Bound (Ancest));
6496 if Compile_Time_Known_Value (Type_High_Bound (Ancest)) then
6497 Hi := Expr_Rep_Value (Type_High_Bound (Ancest));
6503 Ancest := Ancestor_Subtype (Ancest);
6506 Ancest := Base_Type (T);
6508 if Is_Generic_Type (Ancest) then
6514 -- Fixed-point types. We can't simply use Expr_Value to get the
6515 -- Corresponding_Integer_Value values of the bounds, since these do not
6516 -- get set till the type is frozen, and this routine can be called
6517 -- before the type is frozen. Similarly the test for bounds being static
6518 -- needs to include the case where we have unanalyzed real literals for
6521 elsif Is_Fixed_Point_Type (T) then
6523 -- The following loop is looking for the nearest compile time known
6524 -- bounds following the ancestor subtype chain. The idea is to find
6525 -- the most restrictive known bounds information.
6529 if Ancest = Any_Type or else Etype (Ancest) = Any_Type then
6533 -- Note: In the following two tests for LoSet and HiSet, it may
6534 -- seem redundant to test for N_Real_Literal here since normally
6535 -- one would assume that the test for the value being known at
6536 -- compile time includes this case. However, there is a glitch.
6537 -- If the real literal comes from folding a non-static expression,
6538 -- then we don't consider any non- static expression to be known
6539 -- at compile time if we are in configurable run time mode (needed
6540 -- in some cases to give a clearer definition of what is and what
6541 -- is not accepted). So the test is indeed needed. Without it, we
6542 -- would set neither Lo_Set nor Hi_Set and get an infinite loop.
6545 if Nkind (Type_Low_Bound (Ancest)) = N_Real_Literal
6546 or else Compile_Time_Known_Value (Type_Low_Bound (Ancest))
6548 LoR := Expr_Value_R (Type_Low_Bound (Ancest));
6555 if Nkind (Type_High_Bound (Ancest)) = N_Real_Literal
6556 or else Compile_Time_Known_Value (Type_High_Bound (Ancest))
6558 HiR := Expr_Value_R (Type_High_Bound (Ancest));
6564 Ancest := Ancestor_Subtype (Ancest);
6567 Ancest := Base_Type (T);
6569 if Is_Generic_Type (Ancest) then
6575 Lo := UR_To_Uint (LoR / Small_Value (T));
6576 Hi := UR_To_Uint (HiR / Small_Value (T));
6578 -- No other types allowed
6581 raise Program_Error;
6584 -- Fall through with Hi and Lo set. Deal with biased case
6587 and then not Is_Fixed_Point_Type (T)
6588 and then not (Is_Enumeration_Type (T)
6589 and then Has_Non_Standard_Rep (T)))
6590 or else Has_Biased_Representation (T)
6596 -- Signed case. Note that we consider types like range 1 .. -1 to be
6597 -- signed for the purpose of computing the size, since the bounds have
6598 -- to be accommodated in the base type.
6600 if Lo < 0 or else Hi < 0 then
6604 -- S = size, B = 2 ** (size - 1) (can accommodate -B .. +(B - 1))
6605 -- Note that we accommodate the case where the bounds cross. This
6606 -- can happen either because of the way the bounds are declared
6607 -- or because of the algorithm in Freeze_Fixed_Point_Type.
6621 -- If both bounds are positive, make sure that both are represen-
6622 -- table in the case where the bounds are crossed. This can happen
6623 -- either because of the way the bounds are declared, or because of
6624 -- the algorithm in Freeze_Fixed_Point_Type.
6630 -- S = size, (can accommodate 0 .. (2**size - 1))
6633 while Hi >= Uint_2 ** S loop
6641 ---------------------------
6642 -- New_Stream_Subprogram --
6643 ---------------------------
6645 procedure New_Stream_Subprogram
6649 Nam : TSS_Name_Type)
6651 Loc : constant Source_Ptr := Sloc (N);
6652 Sname : constant Name_Id := Make_TSS_Name (Base_Type (Ent), Nam);
6653 Subp_Id : Entity_Id;
6654 Subp_Decl : Node_Id;
6658 Defer_Declaration : constant Boolean :=
6659 Is_Tagged_Type (Ent) or else Is_Private_Type (Ent);
6660 -- For a tagged type, there is a declaration for each stream attribute
6661 -- at the freeze point, and we must generate only a completion of this
6662 -- declaration. We do the same for private types, because the full view
6663 -- might be tagged. Otherwise we generate a declaration at the point of
6664 -- the attribute definition clause.
6666 function Build_Spec return Node_Id;
6667 -- Used for declaration and renaming declaration, so that this is
6668 -- treated as a renaming_as_body.
6674 function Build_Spec return Node_Id is
6675 Out_P : constant Boolean := (Nam = TSS_Stream_Read);
6678 T_Ref : constant Node_Id := New_Reference_To (Etyp, Loc);
6681 Subp_Id := Make_Defining_Identifier (Loc, Sname);
6683 -- S : access Root_Stream_Type'Class
6685 Formals := New_List (
6686 Make_Parameter_Specification (Loc,
6687 Defining_Identifier =>
6688 Make_Defining_Identifier (Loc, Name_S),
6690 Make_Access_Definition (Loc,
6693 Designated_Type (Etype (F)), Loc))));
6695 if Nam = TSS_Stream_Input then
6696 Spec := Make_Function_Specification (Loc,
6697 Defining_Unit_Name => Subp_Id,
6698 Parameter_Specifications => Formals,
6699 Result_Definition => T_Ref);
6704 Make_Parameter_Specification (Loc,
6705 Defining_Identifier => Make_Defining_Identifier (Loc, Name_V),
6706 Out_Present => Out_P,
6707 Parameter_Type => T_Ref));
6710 Make_Procedure_Specification (Loc,
6711 Defining_Unit_Name => Subp_Id,
6712 Parameter_Specifications => Formals);
6718 -- Start of processing for New_Stream_Subprogram
6721 F := First_Formal (Subp);
6723 if Ekind (Subp) = E_Procedure then
6724 Etyp := Etype (Next_Formal (F));
6726 Etyp := Etype (Subp);
6729 -- Prepare subprogram declaration and insert it as an action on the
6730 -- clause node. The visibility for this entity is used to test for
6731 -- visibility of the attribute definition clause (in the sense of
6732 -- 8.3(23) as amended by AI-195).
6734 if not Defer_Declaration then
6736 Make_Subprogram_Declaration (Loc,
6737 Specification => Build_Spec);
6739 -- For a tagged type, there is always a visible declaration for each
6740 -- stream TSS (it is a predefined primitive operation), and the
6741 -- completion of this declaration occurs at the freeze point, which is
6742 -- not always visible at places where the attribute definition clause is
6743 -- visible. So, we create a dummy entity here for the purpose of
6744 -- tracking the visibility of the attribute definition clause itself.
6748 Make_Defining_Identifier (Loc, New_External_Name (Sname, 'V'));
6750 Make_Object_Declaration (Loc,
6751 Defining_Identifier => Subp_Id,
6752 Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc));
6755 Insert_Action (N, Subp_Decl);
6756 Set_Entity (N, Subp_Id);
6759 Make_Subprogram_Renaming_Declaration (Loc,
6760 Specification => Build_Spec,
6761 Name => New_Reference_To (Subp, Loc));
6763 if Defer_Declaration then
6764 Set_TSS (Base_Type (Ent), Subp_Id);
6766 Insert_Action (N, Subp_Decl);
6767 Copy_TSS (Subp_Id, Base_Type (Ent));
6769 end New_Stream_Subprogram;
6771 ------------------------
6772 -- Rep_Item_Too_Early --
6773 ------------------------
6775 function Rep_Item_Too_Early (T : Entity_Id; N : Node_Id) return Boolean is
6777 -- Cannot apply non-operational rep items to generic types
6779 if Is_Operational_Item (N) then
6783 and then Is_Generic_Type (Root_Type (T))
6785 Error_Msg_N ("representation item not allowed for generic type", N);
6789 -- Otherwise check for incomplete type
6791 if Is_Incomplete_Or_Private_Type (T)
6792 and then No (Underlying_Type (T))
6795 ("representation item must be after full type declaration", N);
6798 -- If the type has incomplete components, a representation clause is
6799 -- illegal but stream attributes and Convention pragmas are correct.
6801 elsif Has_Private_Component (T) then
6802 if Nkind (N) = N_Pragma then
6806 ("representation item must appear after type is fully defined",
6813 end Rep_Item_Too_Early;
6815 -----------------------
6816 -- Rep_Item_Too_Late --
6817 -----------------------
6819 function Rep_Item_Too_Late
6822 FOnly : Boolean := False) return Boolean
6825 Parent_Type : Entity_Id;
6828 -- Output the too late message. Note that this is not considered a
6829 -- serious error, since the effect is simply that we ignore the
6830 -- representation clause in this case.
6836 procedure Too_Late is
6838 Error_Msg_N ("|representation item appears too late!", N);
6841 -- Start of processing for Rep_Item_Too_Late
6844 -- First make sure entity is not frozen (RM 13.1(9)). Exclude imported
6845 -- types, which may be frozen if they appear in a representation clause
6846 -- for a local type.
6849 and then not From_With_Type (T)
6852 S := First_Subtype (T);
6854 if Present (Freeze_Node (S)) then
6856 ("?no more representation items for }", Freeze_Node (S), S);
6861 -- Check for case of non-tagged derived type whose parent either has
6862 -- primitive operations, or is a by reference type (RM 13.1(10)).
6866 and then Is_Derived_Type (T)
6867 and then not Is_Tagged_Type (T)
6869 Parent_Type := Etype (Base_Type (T));
6871 if Has_Primitive_Operations (Parent_Type) then
6874 ("primitive operations already defined for&!", N, Parent_Type);
6877 elsif Is_By_Reference_Type (Parent_Type) then
6880 ("parent type & is a by reference type!", N, Parent_Type);
6885 -- No error, link item into head of chain of rep items for the entity,
6886 -- but avoid chaining if we have an overloadable entity, and the pragma
6887 -- is one that can apply to multiple overloaded entities.
6889 if Is_Overloadable (T)
6890 and then Nkind (N) = N_Pragma
6893 Pname : constant Name_Id := Pragma_Name (N);
6895 if Pname = Name_Convention or else
6896 Pname = Name_Import or else
6897 Pname = Name_Export or else
6898 Pname = Name_External or else
6899 Pname = Name_Interface
6906 Record_Rep_Item (T, N);
6908 end Rep_Item_Too_Late;
6910 -------------------------------------
6911 -- Replace_Type_References_Generic --
6912 -------------------------------------
6914 procedure Replace_Type_References_Generic (N : Node_Id; TName : Name_Id) is
6916 function Replace_Node (N : Node_Id) return Traverse_Result;
6917 -- Processes a single node in the traversal procedure below, checking
6918 -- if node N should be replaced, and if so, doing the replacement.
6920 procedure Replace_Type_Refs is new Traverse_Proc (Replace_Node);
6921 -- This instantiation provides the body of Replace_Type_References
6927 function Replace_Node (N : Node_Id) return Traverse_Result is
6932 -- Case of identifier
6934 if Nkind (N) = N_Identifier then
6936 -- If not the type name, all done with this node
6938 if Chars (N) /= TName then
6941 -- Otherwise do the replacement and we are done with this node
6944 Replace_Type_Reference (N);
6948 -- Case of selected component (which is what a qualification
6949 -- looks like in the unanalyzed tree, which is what we have.
6951 elsif Nkind (N) = N_Selected_Component then
6953 -- If selector name is not our type, keeping going (we might
6954 -- still have an occurrence of the type in the prefix).
6956 if Nkind (Selector_Name (N)) /= N_Identifier
6957 or else Chars (Selector_Name (N)) /= TName
6961 -- Selector name is our type, check qualification
6964 -- Loop through scopes and prefixes, doing comparison
6969 -- Continue if no more scopes or scope with no name
6971 if No (S) or else Nkind (S) not in N_Has_Chars then
6975 -- Do replace if prefix is an identifier matching the
6976 -- scope that we are currently looking at.
6978 if Nkind (P) = N_Identifier
6979 and then Chars (P) = Chars (S)
6981 Replace_Type_Reference (N);
6985 -- Go check scope above us if prefix is itself of the
6986 -- form of a selected component, whose selector matches
6987 -- the scope we are currently looking at.
6989 if Nkind (P) = N_Selected_Component
6990 and then Nkind (Selector_Name (P)) = N_Identifier
6991 and then Chars (Selector_Name (P)) = Chars (S)
6996 -- For anything else, we don't have a match, so keep on
6997 -- going, there are still some weird cases where we may
6998 -- still have a replacement within the prefix.
7006 -- Continue for any other node kind
7014 Replace_Type_Refs (N);
7015 end Replace_Type_References_Generic;
7017 -------------------------
7018 -- Same_Representation --
7019 -------------------------
7021 function Same_Representation (Typ1, Typ2 : Entity_Id) return Boolean is
7022 T1 : constant Entity_Id := Underlying_Type (Typ1);
7023 T2 : constant Entity_Id := Underlying_Type (Typ2);
7026 -- A quick check, if base types are the same, then we definitely have
7027 -- the same representation, because the subtype specific representation
7028 -- attributes (Size and Alignment) do not affect representation from
7029 -- the point of view of this test.
7031 if Base_Type (T1) = Base_Type (T2) then
7034 elsif Is_Private_Type (Base_Type (T2))
7035 and then Base_Type (T1) = Full_View (Base_Type (T2))
7040 -- Tagged types never have differing representations
7042 if Is_Tagged_Type (T1) then
7046 -- Representations are definitely different if conventions differ
7048 if Convention (T1) /= Convention (T2) then
7052 -- Representations are different if component alignments differ
7054 if (Is_Record_Type (T1) or else Is_Array_Type (T1))
7056 (Is_Record_Type (T2) or else Is_Array_Type (T2))
7057 and then Component_Alignment (T1) /= Component_Alignment (T2)
7062 -- For arrays, the only real issue is component size. If we know the
7063 -- component size for both arrays, and it is the same, then that's
7064 -- good enough to know we don't have a change of representation.
7066 if Is_Array_Type (T1) then
7067 if Known_Component_Size (T1)
7068 and then Known_Component_Size (T2)
7069 and then Component_Size (T1) = Component_Size (T2)
7075 -- Types definitely have same representation if neither has non-standard
7076 -- representation since default representations are always consistent.
7077 -- If only one has non-standard representation, and the other does not,
7078 -- then we consider that they do not have the same representation. They
7079 -- might, but there is no way of telling early enough.
7081 if Has_Non_Standard_Rep (T1) then
7082 if not Has_Non_Standard_Rep (T2) then
7086 return not Has_Non_Standard_Rep (T2);
7089 -- Here the two types both have non-standard representation, and we need
7090 -- to determine if they have the same non-standard representation.
7092 -- For arrays, we simply need to test if the component sizes are the
7093 -- same. Pragma Pack is reflected in modified component sizes, so this
7094 -- check also deals with pragma Pack.
7096 if Is_Array_Type (T1) then
7097 return Component_Size (T1) = Component_Size (T2);
7099 -- Tagged types always have the same representation, because it is not
7100 -- possible to specify different representations for common fields.
7102 elsif Is_Tagged_Type (T1) then
7105 -- Case of record types
7107 elsif Is_Record_Type (T1) then
7109 -- Packed status must conform
7111 if Is_Packed (T1) /= Is_Packed (T2) then
7114 -- Otherwise we must check components. Typ2 maybe a constrained
7115 -- subtype with fewer components, so we compare the components
7116 -- of the base types.
7119 Record_Case : declare
7120 CD1, CD2 : Entity_Id;
7122 function Same_Rep return Boolean;
7123 -- CD1 and CD2 are either components or discriminants. This
7124 -- function tests whether the two have the same representation
7130 function Same_Rep return Boolean is
7132 if No (Component_Clause (CD1)) then
7133 return No (Component_Clause (CD2));
7137 Present (Component_Clause (CD2))
7139 Component_Bit_Offset (CD1) = Component_Bit_Offset (CD2)
7141 Esize (CD1) = Esize (CD2);
7145 -- Start of processing for Record_Case
7148 if Has_Discriminants (T1) then
7149 CD1 := First_Discriminant (T1);
7150 CD2 := First_Discriminant (T2);
7152 -- The number of discriminants may be different if the
7153 -- derived type has fewer (constrained by values). The
7154 -- invisible discriminants retain the representation of
7155 -- the original, so the discrepancy does not per se
7156 -- indicate a different representation.
7159 and then Present (CD2)
7161 if not Same_Rep then
7164 Next_Discriminant (CD1);
7165 Next_Discriminant (CD2);
7170 CD1 := First_Component (Underlying_Type (Base_Type (T1)));
7171 CD2 := First_Component (Underlying_Type (Base_Type (T2)));
7173 while Present (CD1) loop
7174 if not Same_Rep then
7177 Next_Component (CD1);
7178 Next_Component (CD2);
7186 -- For enumeration types, we must check each literal to see if the
7187 -- representation is the same. Note that we do not permit enumeration
7188 -- representation clauses for Character and Wide_Character, so these
7189 -- cases were already dealt with.
7191 elsif Is_Enumeration_Type (T1) then
7192 Enumeration_Case : declare
7196 L1 := First_Literal (T1);
7197 L2 := First_Literal (T2);
7199 while Present (L1) loop
7200 if Enumeration_Rep (L1) /= Enumeration_Rep (L2) then
7210 end Enumeration_Case;
7212 -- Any other types have the same representation for these purposes
7217 end Same_Representation;
7223 procedure Set_Biased
7227 Biased : Boolean := True)
7231 Set_Has_Biased_Representation (E);
7233 if Warn_On_Biased_Representation then
7235 ("?" & Msg & " forces biased representation for&", N, E);
7240 --------------------
7241 -- Set_Enum_Esize --
7242 --------------------
7244 procedure Set_Enum_Esize (T : Entity_Id) is
7252 -- Find the minimum standard size (8,16,32,64) that fits
7254 Lo := Enumeration_Rep (Entity (Type_Low_Bound (T)));
7255 Hi := Enumeration_Rep (Entity (Type_High_Bound (T)));
7258 if Lo >= -Uint_2**07 and then Hi < Uint_2**07 then
7259 Sz := Standard_Character_Size; -- May be > 8 on some targets
7261 elsif Lo >= -Uint_2**15 and then Hi < Uint_2**15 then
7264 elsif Lo >= -Uint_2**31 and then Hi < Uint_2**31 then
7267 else pragma Assert (Lo >= -Uint_2**63 and then Hi < Uint_2**63);
7272 if Hi < Uint_2**08 then
7273 Sz := Standard_Character_Size; -- May be > 8 on some targets
7275 elsif Hi < Uint_2**16 then
7278 elsif Hi < Uint_2**32 then
7281 else pragma Assert (Hi < Uint_2**63);
7286 -- That minimum is the proper size unless we have a foreign convention
7287 -- and the size required is 32 or less, in which case we bump the size
7288 -- up to 32. This is required for C and C++ and seems reasonable for
7289 -- all other foreign conventions.
7291 if Has_Foreign_Convention (T)
7292 and then Esize (T) < Standard_Integer_Size
7294 Init_Esize (T, Standard_Integer_Size);
7300 ------------------------------
7301 -- Validate_Address_Clauses --
7302 ------------------------------
7304 procedure Validate_Address_Clauses is
7306 for J in Address_Clause_Checks.First .. Address_Clause_Checks.Last loop
7308 ACCR : Address_Clause_Check_Record
7309 renames Address_Clause_Checks.Table (J);
7320 -- Skip processing of this entry if warning already posted
7322 if not Address_Warning_Posted (ACCR.N) then
7324 Expr := Original_Node (Expression (ACCR.N));
7328 X_Alignment := Alignment (ACCR.X);
7329 Y_Alignment := Alignment (ACCR.Y);
7331 -- Similarly obtain sizes
7333 X_Size := Esize (ACCR.X);
7334 Y_Size := Esize (ACCR.Y);
7336 -- Check for large object overlaying smaller one
7339 and then X_Size > Uint_0
7340 and then X_Size > Y_Size
7343 ("?& overlays smaller object", ACCR.N, ACCR.X);
7345 ("\?program execution may be erroneous", ACCR.N);
7346 Error_Msg_Uint_1 := X_Size;
7348 ("\?size of & is ^", ACCR.N, ACCR.X);
7349 Error_Msg_Uint_1 := Y_Size;
7351 ("\?size of & is ^", ACCR.N, ACCR.Y);
7353 -- Check for inadequate alignment, both of the base object
7354 -- and of the offset, if any.
7356 -- Note: we do not check the alignment if we gave a size
7357 -- warning, since it would likely be redundant.
7359 elsif Y_Alignment /= Uint_0
7360 and then (Y_Alignment < X_Alignment
7363 Nkind (Expr) = N_Attribute_Reference
7365 Attribute_Name (Expr) = Name_Address
7367 Has_Compatible_Alignment
7368 (ACCR.X, Prefix (Expr))
7369 /= Known_Compatible))
7372 ("?specified address for& may be inconsistent "
7376 ("\?program execution may be erroneous (RM 13.3(27))",
7378 Error_Msg_Uint_1 := X_Alignment;
7380 ("\?alignment of & is ^",
7382 Error_Msg_Uint_1 := Y_Alignment;
7384 ("\?alignment of & is ^",
7386 if Y_Alignment >= X_Alignment then
7388 ("\?but offset is not multiple of alignment",
7395 end Validate_Address_Clauses;
7397 ---------------------------
7398 -- Validate_Independence --
7399 ---------------------------
7401 procedure Validate_Independence is
7402 SU : constant Uint := UI_From_Int (System_Storage_Unit);
7410 procedure Check_Array_Type (Atyp : Entity_Id);
7411 -- Checks if the array type Atyp has independent components, and
7412 -- if not, outputs an appropriate set of error messages.
7414 procedure No_Independence;
7415 -- Output message that independence cannot be guaranteed
7417 function OK_Component (C : Entity_Id) return Boolean;
7418 -- Checks one component to see if it is independently accessible, and
7419 -- if so yields True, otherwise yields False if independent access
7420 -- cannot be guaranteed. This is a conservative routine, it only
7421 -- returns True if it knows for sure, it returns False if it knows
7422 -- there is a problem, or it cannot be sure there is no problem.
7424 procedure Reason_Bad_Component (C : Entity_Id);
7425 -- Outputs continuation message if a reason can be determined for
7426 -- the component C being bad.
7428 ----------------------
7429 -- Check_Array_Type --
7430 ----------------------
7432 procedure Check_Array_Type (Atyp : Entity_Id) is
7433 Ctyp : constant Entity_Id := Component_Type (Atyp);
7436 -- OK if no alignment clause, no pack, and no component size
7438 if not Has_Component_Size_Clause (Atyp)
7439 and then not Has_Alignment_Clause (Atyp)
7440 and then not Is_Packed (Atyp)
7445 -- Check actual component size
7447 if not Known_Component_Size (Atyp)
7448 or else not (Addressable (Component_Size (Atyp))
7449 and then Component_Size (Atyp) < 64)
7450 or else Component_Size (Atyp) mod Esize (Ctyp) /= 0
7454 -- Bad component size, check reason
7456 if Has_Component_Size_Clause (Atyp) then
7458 Get_Attribute_Definition_Clause
7459 (Atyp, Attribute_Component_Size);
7462 Error_Msg_Sloc := Sloc (P);
7463 Error_Msg_N ("\because of Component_Size clause#", N);
7468 if Is_Packed (Atyp) then
7469 P := Get_Rep_Pragma (Atyp, Name_Pack);
7472 Error_Msg_Sloc := Sloc (P);
7473 Error_Msg_N ("\because of pragma Pack#", N);
7478 -- No reason found, just return
7483 -- Array type is OK independence-wise
7486 end Check_Array_Type;
7488 ---------------------
7489 -- No_Independence --
7490 ---------------------
7492 procedure No_Independence is
7494 if Pragma_Name (N) = Name_Independent then
7496 ("independence cannot be guaranteed for&", N, E);
7499 ("independent components cannot be guaranteed for&", N, E);
7501 end No_Independence;
7507 function OK_Component (C : Entity_Id) return Boolean is
7508 Rec : constant Entity_Id := Scope (C);
7509 Ctyp : constant Entity_Id := Etype (C);
7512 -- OK if no component clause, no Pack, and no alignment clause
7514 if No (Component_Clause (C))
7515 and then not Is_Packed (Rec)
7516 and then not Has_Alignment_Clause (Rec)
7521 -- Here we look at the actual component layout. A component is
7522 -- addressable if its size is a multiple of the Esize of the
7523 -- component type, and its starting position in the record has
7524 -- appropriate alignment, and the record itself has appropriate
7525 -- alignment to guarantee the component alignment.
7527 -- Make sure sizes are static, always assume the worst for any
7528 -- cases where we cannot check static values.
7530 if not (Known_Static_Esize (C)
7531 and then Known_Static_Esize (Ctyp))
7536 -- Size of component must be addressable or greater than 64 bits
7537 -- and a multiple of bytes.
7539 if not Addressable (Esize (C))
7540 and then Esize (C) < Uint_64
7545 -- Check size is proper multiple
7547 if Esize (C) mod Esize (Ctyp) /= 0 then
7551 -- Check alignment of component is OK
7553 if not Known_Component_Bit_Offset (C)
7554 or else Component_Bit_Offset (C) < Uint_0
7555 or else Component_Bit_Offset (C) mod Esize (Ctyp) /= 0
7560 -- Check alignment of record type is OK
7562 if not Known_Alignment (Rec)
7563 or else (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
7568 -- All tests passed, component is addressable
7573 --------------------------
7574 -- Reason_Bad_Component --
7575 --------------------------
7577 procedure Reason_Bad_Component (C : Entity_Id) is
7578 Rec : constant Entity_Id := Scope (C);
7579 Ctyp : constant Entity_Id := Etype (C);
7582 -- If component clause present assume that's the problem
7584 if Present (Component_Clause (C)) then
7585 Error_Msg_Sloc := Sloc (Component_Clause (C));
7586 Error_Msg_N ("\because of Component_Clause#", N);
7590 -- If pragma Pack clause present, assume that's the problem
7592 if Is_Packed (Rec) then
7593 P := Get_Rep_Pragma (Rec, Name_Pack);
7596 Error_Msg_Sloc := Sloc (P);
7597 Error_Msg_N ("\because of pragma Pack#", N);
7602 -- See if record has bad alignment clause
7604 if Has_Alignment_Clause (Rec)
7605 and then Known_Alignment (Rec)
7606 and then (Alignment (Rec) * SU) mod Esize (Ctyp) /= 0
7608 P := Get_Attribute_Definition_Clause (Rec, Attribute_Alignment);
7611 Error_Msg_Sloc := Sloc (P);
7612 Error_Msg_N ("\because of Alignment clause#", N);
7616 -- Couldn't find a reason, so return without a message
7619 end Reason_Bad_Component;
7621 -- Start of processing for Validate_Independence
7624 for J in Independence_Checks.First .. Independence_Checks.Last loop
7625 N := Independence_Checks.Table (J).N;
7626 E := Independence_Checks.Table (J).E;
7627 IC := Pragma_Name (N) = Name_Independent_Components;
7629 -- Deal with component case
7631 if Ekind (E) = E_Discriminant or else Ekind (E) = E_Component then
7632 if not OK_Component (E) then
7634 Reason_Bad_Component (E);
7639 -- Deal with record with Independent_Components
7641 if IC and then Is_Record_Type (E) then
7642 Comp := First_Component_Or_Discriminant (E);
7643 while Present (Comp) loop
7644 if not OK_Component (Comp) then
7646 Reason_Bad_Component (Comp);
7650 Next_Component_Or_Discriminant (Comp);
7654 -- Deal with address clause case
7656 if Is_Object (E) then
7657 Addr := Address_Clause (E);
7659 if Present (Addr) then
7661 Error_Msg_Sloc := Sloc (Addr);
7662 Error_Msg_N ("\because of Address clause#", N);
7667 -- Deal with independent components for array type
7669 if IC and then Is_Array_Type (E) then
7670 Check_Array_Type (E);
7673 -- Deal with independent components for array object
7675 if IC and then Is_Object (E) and then Is_Array_Type (Etype (E)) then
7676 Check_Array_Type (Etype (E));
7681 end Validate_Independence;
7683 -----------------------------------
7684 -- Validate_Unchecked_Conversion --
7685 -----------------------------------
7687 procedure Validate_Unchecked_Conversion
7689 Act_Unit : Entity_Id)
7696 -- Obtain source and target types. Note that we call Ancestor_Subtype
7697 -- here because the processing for generic instantiation always makes
7698 -- subtypes, and we want the original frozen actual types.
7700 -- If we are dealing with private types, then do the check on their
7701 -- fully declared counterparts if the full declarations have been
7702 -- encountered (they don't have to be visible, but they must exist!)
7704 Source := Ancestor_Subtype (Etype (First_Formal (Act_Unit)));
7706 if Is_Private_Type (Source)
7707 and then Present (Underlying_Type (Source))
7709 Source := Underlying_Type (Source);
7712 Target := Ancestor_Subtype (Etype (Act_Unit));
7714 -- If either type is generic, the instantiation happens within a generic
7715 -- unit, and there is nothing to check. The proper check
7716 -- will happen when the enclosing generic is instantiated.
7718 if Is_Generic_Type (Source) or else Is_Generic_Type (Target) then
7722 if Is_Private_Type (Target)
7723 and then Present (Underlying_Type (Target))
7725 Target := Underlying_Type (Target);
7728 -- Source may be unconstrained array, but not target
7730 if Is_Array_Type (Target)
7731 and then not Is_Constrained (Target)
7734 ("unchecked conversion to unconstrained array not allowed", N);
7738 -- Warn if conversion between two different convention pointers
7740 if Is_Access_Type (Target)
7741 and then Is_Access_Type (Source)
7742 and then Convention (Target) /= Convention (Source)
7743 and then Warn_On_Unchecked_Conversion
7745 -- Give warnings for subprogram pointers only on most targets. The
7746 -- exception is VMS, where data pointers can have different lengths
7747 -- depending on the pointer convention.
7749 if Is_Access_Subprogram_Type (Target)
7750 or else Is_Access_Subprogram_Type (Source)
7751 or else OpenVMS_On_Target
7754 ("?conversion between pointers with different conventions!", N);
7758 -- Warn if one of the operands is Ada.Calendar.Time. Do not emit a
7759 -- warning when compiling GNAT-related sources.
7761 if Warn_On_Unchecked_Conversion
7762 and then not In_Predefined_Unit (N)
7763 and then RTU_Loaded (Ada_Calendar)
7765 (Chars (Source) = Name_Time
7767 Chars (Target) = Name_Time)
7769 -- If Ada.Calendar is loaded and the name of one of the operands is
7770 -- Time, there is a good chance that this is Ada.Calendar.Time.
7773 Calendar_Time : constant Entity_Id :=
7774 Full_View (RTE (RO_CA_Time));
7776 pragma Assert (Present (Calendar_Time));
7778 if Source = Calendar_Time
7779 or else Target = Calendar_Time
7782 ("?representation of 'Time values may change between " &
7783 "'G'N'A'T versions", N);
7788 -- Make entry in unchecked conversion table for later processing by
7789 -- Validate_Unchecked_Conversions, which will check sizes and alignments
7790 -- (using values set by the back-end where possible). This is only done
7791 -- if the appropriate warning is active.
7793 if Warn_On_Unchecked_Conversion then
7794 Unchecked_Conversions.Append
7795 (New_Val => UC_Entry'
7800 -- If both sizes are known statically now, then back end annotation
7801 -- is not required to do a proper check but if either size is not
7802 -- known statically, then we need the annotation.
7804 if Known_Static_RM_Size (Source)
7805 and then Known_Static_RM_Size (Target)
7809 Back_Annotate_Rep_Info := True;
7813 -- If unchecked conversion to access type, and access type is declared
7814 -- in the same unit as the unchecked conversion, then set the
7815 -- No_Strict_Aliasing flag (no strict aliasing is implicit in this
7818 if Is_Access_Type (Target) and then
7819 In_Same_Source_Unit (Target, N)
7821 Set_No_Strict_Aliasing (Implementation_Base_Type (Target));
7824 -- Generate N_Validate_Unchecked_Conversion node for back end in
7825 -- case the back end needs to perform special validation checks.
7827 -- Shouldn't this be in Exp_Ch13, since the check only gets done
7828 -- if we have full expansion and the back end is called ???
7831 Make_Validate_Unchecked_Conversion (Sloc (N));
7832 Set_Source_Type (Vnode, Source);
7833 Set_Target_Type (Vnode, Target);
7835 -- If the unchecked conversion node is in a list, just insert before it.
7836 -- If not we have some strange case, not worth bothering about.
7838 if Is_List_Member (N) then
7839 Insert_After (N, Vnode);
7841 end Validate_Unchecked_Conversion;
7843 ------------------------------------
7844 -- Validate_Unchecked_Conversions --
7845 ------------------------------------
7847 procedure Validate_Unchecked_Conversions is
7849 for N in Unchecked_Conversions.First .. Unchecked_Conversions.Last loop
7851 T : UC_Entry renames Unchecked_Conversions.Table (N);
7853 Eloc : constant Source_Ptr := T.Eloc;
7854 Source : constant Entity_Id := T.Source;
7855 Target : constant Entity_Id := T.Target;
7861 -- This validation check, which warns if we have unequal sizes for
7862 -- unchecked conversion, and thus potentially implementation
7863 -- dependent semantics, is one of the few occasions on which we
7864 -- use the official RM size instead of Esize. See description in
7865 -- Einfo "Handling of Type'Size Values" for details.
7867 if Serious_Errors_Detected = 0
7868 and then Known_Static_RM_Size (Source)
7869 and then Known_Static_RM_Size (Target)
7871 -- Don't do the check if warnings off for either type, note the
7872 -- deliberate use of OR here instead of OR ELSE to get the flag
7873 -- Warnings_Off_Used set for both types if appropriate.
7875 and then not (Has_Warnings_Off (Source)
7877 Has_Warnings_Off (Target))
7879 Source_Siz := RM_Size (Source);
7880 Target_Siz := RM_Size (Target);
7882 if Source_Siz /= Target_Siz then
7884 ("?types for unchecked conversion have different sizes!",
7887 if All_Errors_Mode then
7888 Error_Msg_Name_1 := Chars (Source);
7889 Error_Msg_Uint_1 := Source_Siz;
7890 Error_Msg_Name_2 := Chars (Target);
7891 Error_Msg_Uint_2 := Target_Siz;
7892 Error_Msg ("\size of % is ^, size of % is ^?", Eloc);
7894 Error_Msg_Uint_1 := UI_Abs (Source_Siz - Target_Siz);
7896 if Is_Discrete_Type (Source)
7897 and then Is_Discrete_Type (Target)
7899 if Source_Siz > Target_Siz then
7901 ("\?^ high order bits of source will be ignored!",
7904 elsif Is_Unsigned_Type (Source) then
7906 ("\?source will be extended with ^ high order " &
7907 "zero bits?!", Eloc);
7911 ("\?source will be extended with ^ high order " &
7916 elsif Source_Siz < Target_Siz then
7917 if Is_Discrete_Type (Target) then
7918 if Bytes_Big_Endian then
7920 ("\?target value will include ^ undefined " &
7925 ("\?target value will include ^ undefined " &
7932 ("\?^ trailing bits of target value will be " &
7933 "undefined!", Eloc);
7936 else pragma Assert (Source_Siz > Target_Siz);
7938 ("\?^ trailing bits of source will be ignored!",
7945 -- If both types are access types, we need to check the alignment.
7946 -- If the alignment of both is specified, we can do it here.
7948 if Serious_Errors_Detected = 0
7949 and then Ekind (Source) in Access_Kind
7950 and then Ekind (Target) in Access_Kind
7951 and then Target_Strict_Alignment
7952 and then Present (Designated_Type (Source))
7953 and then Present (Designated_Type (Target))
7956 D_Source : constant Entity_Id := Designated_Type (Source);
7957 D_Target : constant Entity_Id := Designated_Type (Target);
7960 if Known_Alignment (D_Source)
7961 and then Known_Alignment (D_Target)
7964 Source_Align : constant Uint := Alignment (D_Source);
7965 Target_Align : constant Uint := Alignment (D_Target);
7968 if Source_Align < Target_Align
7969 and then not Is_Tagged_Type (D_Source)
7971 -- Suppress warning if warnings suppressed on either
7972 -- type or either designated type. Note the use of
7973 -- OR here instead of OR ELSE. That is intentional,
7974 -- we would like to set flag Warnings_Off_Used in
7975 -- all types for which warnings are suppressed.
7977 and then not (Has_Warnings_Off (D_Source)
7979 Has_Warnings_Off (D_Target)
7981 Has_Warnings_Off (Source)
7983 Has_Warnings_Off (Target))
7985 Error_Msg_Uint_1 := Target_Align;
7986 Error_Msg_Uint_2 := Source_Align;
7987 Error_Msg_Node_1 := D_Target;
7988 Error_Msg_Node_2 := D_Source;
7990 ("?alignment of & (^) is stricter than " &
7991 "alignment of & (^)!", Eloc);
7993 ("\?resulting access value may have invalid " &
7994 "alignment!", Eloc);
8002 end Validate_Unchecked_Conversions;
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