1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2005, 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 2, 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 COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
25 ------------------------------------------------------------------------------
27 with Ada.Characters.Latin_1; use Ada.Characters.Latin_1;
29 with Atree; use Atree;
30 with Checks; use Checks;
31 with Einfo; use Einfo;
32 with Errout; use Errout;
34 with Exp_Tss; use Exp_Tss;
35 with Exp_Util; use Exp_Util;
36 with Expander; use Expander;
37 with Freeze; use Freeze;
39 with Lib.Xref; use Lib.Xref;
40 with Namet; use Namet;
41 with Nlists; use Nlists;
42 with Nmake; use Nmake;
44 with Restrict; use Restrict;
45 with Rident; use Rident;
46 with Rtsfind; use Rtsfind;
47 with Sdefault; use Sdefault;
49 with Sem_Cat; use Sem_Cat;
50 with Sem_Ch6; use Sem_Ch6;
51 with Sem_Ch8; use Sem_Ch8;
52 with Sem_Dist; use Sem_Dist;
53 with Sem_Eval; use Sem_Eval;
54 with Sem_Res; use Sem_Res;
55 with Sem_Type; use Sem_Type;
56 with Sem_Util; use Sem_Util;
57 with Stand; use Stand;
58 with Sinfo; use Sinfo;
59 with Sinput; use Sinput;
60 with Snames; use Snames;
62 with Stringt; use Stringt;
63 with Targparm; use Targparm;
64 with Ttypes; use Ttypes;
65 with Ttypef; use Ttypef;
66 with Tbuild; use Tbuild;
67 with Uintp; use Uintp;
68 with Urealp; use Urealp;
69 with Widechar; use Widechar;
71 package body Sem_Attr is
73 True_Value : constant Uint := Uint_1;
74 False_Value : constant Uint := Uint_0;
75 -- Synonyms to be used when these constants are used as Boolean values
77 Bad_Attribute : exception;
78 -- Exception raised if an error is detected during attribute processing,
79 -- used so that we can abandon the processing so we don't run into
80 -- trouble with cascaded errors.
82 -- The following array is the list of attributes defined in the Ada 83 RM
84 Attribute_83 : constant Attribute_Class_Array := Attribute_Class_Array'(
90 Attribute_Constrained |
103 Attribute_Leading_Part |
105 Attribute_Machine_Emax |
106 Attribute_Machine_Emin |
107 Attribute_Machine_Mantissa |
108 Attribute_Machine_Overflows |
109 Attribute_Machine_Radix |
110 Attribute_Machine_Rounds |
116 Attribute_Safe_Emax |
117 Attribute_Safe_Large |
118 Attribute_Safe_Small |
121 Attribute_Storage_Size |
123 Attribute_Terminated |
126 Attribute_Width => True,
129 -----------------------
130 -- Local_Subprograms --
131 -----------------------
133 procedure Eval_Attribute (N : Node_Id);
134 -- Performs compile time evaluation of attributes where possible, leaving
135 -- the Is_Static_Expression/Raises_Constraint_Error flags appropriately
136 -- set, and replacing the node with a literal node if the value can be
137 -- computed at compile time. All static attribute references are folded,
138 -- as well as a number of cases of non-static attributes that can always
139 -- be computed at compile time (e.g. floating-point model attributes that
140 -- are applied to non-static subtypes). Of course in such cases, the
141 -- Is_Static_Expression flag will not be set on the resulting literal.
142 -- Note that the only required action of this procedure is to catch the
143 -- static expression cases as described in the RM. Folding of other cases
144 -- is done where convenient, but some additional non-static folding is in
145 -- N_Expand_Attribute_Reference in cases where this is more convenient.
147 function Is_Anonymous_Tagged_Base
151 -- For derived tagged types that constrain parent discriminants we build
152 -- an anonymous unconstrained base type. We need to recognize the relation
153 -- between the two when analyzing an access attribute for a constrained
154 -- component, before the full declaration for Typ has been analyzed, and
155 -- where therefore the prefix of the attribute does not match the enclosing
158 -----------------------
159 -- Analyze_Attribute --
160 -----------------------
162 procedure Analyze_Attribute (N : Node_Id) is
163 Loc : constant Source_Ptr := Sloc (N);
164 Aname : constant Name_Id := Attribute_Name (N);
165 P : constant Node_Id := Prefix (N);
166 Exprs : constant List_Id := Expressions (N);
167 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
172 -- Type of prefix after analysis
174 P_Base_Type : Entity_Id;
175 -- Base type of prefix after analysis
177 -----------------------
178 -- Local Subprograms --
179 -----------------------
181 procedure Analyze_Access_Attribute;
182 -- Used for Access, Unchecked_Access, Unrestricted_Access attributes.
183 -- Internally, Id distinguishes which of the three cases is involved.
185 procedure Check_Array_Or_Scalar_Type;
186 -- Common procedure used by First, Last, Range attribute to check
187 -- that the prefix is a constrained array or scalar type, or a name
188 -- of an array object, and that an argument appears only if appropriate
189 -- (i.e. only in the array case).
191 procedure Check_Array_Type;
192 -- Common semantic checks for all array attributes. Checks that the
193 -- prefix is a constrained array type or the name of an array object.
194 -- The error message for non-arrays is specialized appropriately.
196 procedure Check_Asm_Attribute;
197 -- Common semantic checks for Asm_Input and Asm_Output attributes
199 procedure Check_Component;
200 -- Common processing for Bit_Position, First_Bit, Last_Bit, and
201 -- Position. Checks prefix is an appropriate selected component.
203 procedure Check_Decimal_Fixed_Point_Type;
204 -- Check that prefix of attribute N is a decimal fixed-point type
206 procedure Check_Dereference;
207 -- If the prefix of attribute is an object of an access type, then
208 -- introduce an explicit deference, and adjust P_Type accordingly.
210 procedure Check_Discrete_Type;
211 -- Verify that prefix of attribute N is a discrete type
214 -- Check that no attribute arguments are present
216 procedure Check_Either_E0_Or_E1;
217 -- Check that there are zero or one attribute arguments present
220 -- Check that exactly one attribute argument is present
223 -- Check that two attribute arguments are present
225 procedure Check_Enum_Image;
226 -- If the prefix type is an enumeration type, set all its literals
227 -- as referenced, since the image function could possibly end up
228 -- referencing any of the literals indirectly.
230 procedure Check_Fixed_Point_Type;
231 -- Verify that prefix of attribute N is a fixed type
233 procedure Check_Fixed_Point_Type_0;
234 -- Verify that prefix of attribute N is a fixed type and that
235 -- no attribute expressions are present
237 procedure Check_Floating_Point_Type;
238 -- Verify that prefix of attribute N is a float type
240 procedure Check_Floating_Point_Type_0;
241 -- Verify that prefix of attribute N is a float type and that
242 -- no attribute expressions are present
244 procedure Check_Floating_Point_Type_1;
245 -- Verify that prefix of attribute N is a float type and that
246 -- exactly one attribute expression is present
248 procedure Check_Floating_Point_Type_2;
249 -- Verify that prefix of attribute N is a float type and that
250 -- two attribute expressions are present
252 procedure Legal_Formal_Attribute;
253 -- Common processing for attributes Definite, Has_Access_Values,
254 -- and Has_Discriminants
256 procedure Check_Integer_Type;
257 -- Verify that prefix of attribute N is an integer type
259 procedure Check_Library_Unit;
260 -- Verify that prefix of attribute N is a library unit
262 procedure Check_Modular_Integer_Type;
263 -- Verify that prefix of attribute N is a modular integer type
265 procedure Check_Not_Incomplete_Type;
266 -- Check that P (the prefix of the attribute) is not an incomplete
267 -- type or a private type for which no full view has been given.
269 procedure Check_Object_Reference (P : Node_Id);
270 -- Check that P (the prefix of the attribute) is an object reference
272 procedure Check_Program_Unit;
273 -- Verify that prefix of attribute N is a program unit
275 procedure Check_Real_Type;
276 -- Verify that prefix of attribute N is fixed or float type
278 procedure Check_Scalar_Type;
279 -- Verify that prefix of attribute N is a scalar type
281 procedure Check_Standard_Prefix;
282 -- Verify that prefix of attribute N is package Standard
284 procedure Check_Stream_Attribute (Nam : TSS_Name_Type);
285 -- Validity checking for stream attribute. Nam is the TSS name of the
286 -- corresponding possible defined attribute function (e.g. for the
287 -- Read attribute, Nam will be TSS_Stream_Read).
289 procedure Check_Task_Prefix;
290 -- Verify that prefix of attribute N is a task or task type
292 procedure Check_Type;
293 -- Verify that the prefix of attribute N is a type
295 procedure Check_Unit_Name (Nod : Node_Id);
296 -- Check that Nod is of the form of a library unit name, i.e that
297 -- it is an identifier, or a selected component whose prefix is
298 -- itself of the form of a library unit name. Note that this is
299 -- quite different from Check_Program_Unit, since it only checks
300 -- the syntactic form of the name, not the semantic identity. This
301 -- is because it is used with attributes (Elab_Body, Elab_Spec, and
302 -- UET_Address) which can refer to non-visible unit.
304 procedure Error_Attr (Msg : String; Error_Node : Node_Id);
305 pragma No_Return (Error_Attr);
306 procedure Error_Attr;
307 pragma No_Return (Error_Attr);
308 -- Posts error using Error_Msg_N at given node, sets type of attribute
309 -- node to Any_Type, and then raises Bad_Attribute to avoid any further
310 -- semantic processing. The message typically contains a % insertion
311 -- character which is replaced by the attribute name. The call with
312 -- no arguments is used when the caller has already generated the
313 -- required error messages.
315 procedure Standard_Attribute (Val : Int);
316 -- Used to process attributes whose prefix is package Standard which
317 -- yield values of type Universal_Integer. The attribute reference
318 -- node is rewritten with an integer literal of the given value.
320 procedure Unexpected_Argument (En : Node_Id);
321 -- Signal unexpected attribute argument (En is the argument)
323 procedure Validate_Non_Static_Attribute_Function_Call;
324 -- Called when processing an attribute that is a function call to a
325 -- non-static function, i.e. an attribute function that either takes
326 -- non-scalar arguments or returns a non-scalar result. Verifies that
327 -- such a call does not appear in a preelaborable context.
329 ------------------------------
330 -- Analyze_Access_Attribute --
331 ------------------------------
333 procedure Analyze_Access_Attribute is
334 Acc_Type : Entity_Id;
339 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id;
340 -- Build an access-to-object type whose designated type is DT,
341 -- and whose Ekind is appropriate to the attribute type. The
342 -- type that is constructed is returned as the result.
344 procedure Build_Access_Subprogram_Type (P : Node_Id);
345 -- Build an access to subprogram whose designated type is
346 -- the type of the prefix. If prefix is overloaded, so it the
347 -- node itself. The result is stored in Acc_Type.
349 ------------------------------
350 -- Build_Access_Object_Type --
351 ------------------------------
353 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id is
357 if Aname = Name_Unrestricted_Access then
360 (E_Allocator_Type, Current_Scope, Loc, 'A');
364 (E_Access_Attribute_Type, Current_Scope, Loc, 'A');
367 Set_Etype (Typ, Typ);
368 Init_Size_Align (Typ);
370 Set_Associated_Node_For_Itype (Typ, N);
371 Set_Directly_Designated_Type (Typ, DT);
373 end Build_Access_Object_Type;
375 ----------------------------------
376 -- Build_Access_Subprogram_Type --
377 ----------------------------------
379 procedure Build_Access_Subprogram_Type (P : Node_Id) is
380 Index : Interp_Index;
383 function Get_Kind (E : Entity_Id) return Entity_Kind;
384 -- Distinguish between access to regular and protected
391 function Get_Kind (E : Entity_Id) return Entity_Kind is
393 if Convention (E) = Convention_Protected then
394 return E_Access_Protected_Subprogram_Type;
396 return E_Access_Subprogram_Type;
400 -- Start of processing for Build_Access_Subprogram_Type
403 -- In the case of an access to subprogram, use the name of the
404 -- subprogram itself as the designated type. Type-checking in
405 -- this case compares the signatures of the designated types.
407 if not Is_Overloaded (P) then
410 (Get_Kind (Entity (P)), Current_Scope, Loc, 'A');
411 Set_Etype (Acc_Type, Acc_Type);
412 Set_Directly_Designated_Type (Acc_Type, Entity (P));
413 Set_Etype (N, Acc_Type);
416 Get_First_Interp (P, Index, It);
417 Set_Etype (N, Any_Type);
419 while Present (It.Nam) loop
420 if not Is_Intrinsic_Subprogram (It.Nam) then
423 (Get_Kind (It.Nam), Current_Scope, Loc, 'A');
424 Set_Etype (Acc_Type, Acc_Type);
425 Set_Directly_Designated_Type (Acc_Type, It.Nam);
426 Add_One_Interp (N, Acc_Type, Acc_Type);
429 Get_Next_Interp (Index, It);
432 if Etype (N) = Any_Type then
433 Error_Attr ("prefix of % attribute cannot be intrinsic", P);
436 end Build_Access_Subprogram_Type;
438 -- Start of processing for Analyze_Access_Attribute
443 if Nkind (P) = N_Character_Literal then
445 ("prefix of % attribute cannot be enumeration literal", P);
448 -- Case of access to subprogram
450 if Is_Entity_Name (P)
451 and then Is_Overloadable (Entity (P))
453 -- Not allowed for nested subprograms if No_Implicit_Dynamic_Code
454 -- restriction set (since in general a trampoline is required).
456 if not Is_Library_Level_Entity (Entity (P)) then
457 Check_Restriction (No_Implicit_Dynamic_Code, P);
460 -- Build the appropriate subprogram type
462 Build_Access_Subprogram_Type (P);
464 -- For unrestricted access, kill current values, since this
465 -- attribute allows a reference to a local subprogram that
466 -- could modify local variables to be passed out of scope
468 if Aname = Name_Unrestricted_Access then
474 -- Component is an operation of a protected type
476 elsif Nkind (P) = N_Selected_Component
477 and then Is_Overloadable (Entity (Selector_Name (P)))
479 if Ekind (Entity (Selector_Name (P))) = E_Entry then
480 Error_Attr ("prefix of % attribute must be subprogram", P);
483 Build_Access_Subprogram_Type (Selector_Name (P));
487 -- Deal with incorrect reference to a type, but note that some
488 -- accesses are allowed (references to the current type instance).
490 if Is_Entity_Name (P) then
491 Scop := Current_Scope;
494 if Is_Type (Typ) then
496 -- OK if we are within the scope of a limited type
497 -- let's mark the component as having per object constraint
499 if Is_Anonymous_Tagged_Base (Scop, Typ) then
507 Q : Node_Id := Parent (N);
511 and then Nkind (Q) /= N_Component_Declaration
516 Set_Has_Per_Object_Constraint (
517 Defining_Identifier (Q), True);
521 if Nkind (P) = N_Expanded_Name then
523 ("current instance prefix must be a direct name", P);
526 -- If a current instance attribute appears within a
527 -- a component constraint it must appear alone; other
528 -- contexts (default expressions, within a task body)
529 -- are not subject to this restriction.
531 if not In_Default_Expression
532 and then not Has_Completion (Scop)
534 Nkind (Parent (N)) /= N_Discriminant_Association
536 Nkind (Parent (N)) /= N_Index_Or_Discriminant_Constraint
539 ("current instance attribute must appear alone", N);
542 -- OK if we are in initialization procedure for the type
543 -- in question, in which case the reference to the type
544 -- is rewritten as a reference to the current object.
546 elsif Ekind (Scop) = E_Procedure
547 and then Is_Init_Proc (Scop)
548 and then Etype (First_Formal (Scop)) = Typ
551 Make_Attribute_Reference (Loc,
552 Prefix => Make_Identifier (Loc, Name_uInit),
553 Attribute_Name => Name_Unrestricted_Access));
557 -- OK if a task type, this test needs sharpening up ???
559 elsif Is_Task_Type (Typ) then
562 -- Otherwise we have an error case
565 Error_Attr ("% attribute cannot be applied to type", P);
571 -- If we fall through, we have a normal access to object case.
572 -- Unrestricted_Access is legal wherever an allocator would be
573 -- legal, so its Etype is set to E_Allocator. The expected type
574 -- of the other attributes is a general access type, and therefore
575 -- we label them with E_Access_Attribute_Type.
577 if not Is_Overloaded (P) then
578 Acc_Type := Build_Access_Object_Type (P_Type);
579 Set_Etype (N, Acc_Type);
582 Index : Interp_Index;
586 Set_Etype (N, Any_Type);
587 Get_First_Interp (P, Index, It);
589 while Present (It.Typ) loop
590 Acc_Type := Build_Access_Object_Type (It.Typ);
591 Add_One_Interp (N, Acc_Type, Acc_Type);
592 Get_Next_Interp (Index, It);
597 -- If we have an access to an object, and the attribute comes
598 -- from source, then set the object as potentially source modified.
599 -- We do this because the resulting access pointer can be used to
600 -- modify the variable, and we might not detect this, leading to
601 -- some junk warnings.
603 if Is_Entity_Name (P) then
604 Set_Never_Set_In_Source (Entity (P), False);
607 -- Check for aliased view unless unrestricted case. We allow
608 -- a nonaliased prefix when within an instance because the
609 -- prefix may have been a tagged formal object, which is
610 -- defined to be aliased even when the actual might not be
611 -- (other instance cases will have been caught in the generic).
612 -- Similarly, within an inlined body we know that the attribute
613 -- is legal in the original subprogram, and therefore legal in
616 if Aname /= Name_Unrestricted_Access
617 and then not Is_Aliased_View (P)
618 and then not In_Instance
619 and then not In_Inlined_Body
621 Error_Attr ("prefix of % attribute must be aliased", P);
623 end Analyze_Access_Attribute;
625 --------------------------------
626 -- Check_Array_Or_Scalar_Type --
627 --------------------------------
629 procedure Check_Array_Or_Scalar_Type is
633 -- Dimension number for array attributes.
636 -- Case of string literal or string literal subtype. These cases
637 -- cannot arise from legal Ada code, but the expander is allowed
638 -- to generate them. They require special handling because string
639 -- literal subtypes do not have standard bounds (the whole idea
640 -- of these subtypes is to avoid having to generate the bounds)
642 if Ekind (P_Type) = E_String_Literal_Subtype then
643 Set_Etype (N, Etype (First_Index (P_Base_Type)));
648 elsif Is_Scalar_Type (P_Type) then
652 Error_Attr ("invalid argument in % attribute", E1);
654 Set_Etype (N, P_Base_Type);
658 -- The following is a special test to allow 'First to apply to
659 -- private scalar types if the attribute comes from generated
660 -- code. This occurs in the case of Normalize_Scalars code.
662 elsif Is_Private_Type (P_Type)
663 and then Present (Full_View (P_Type))
664 and then Is_Scalar_Type (Full_View (P_Type))
665 and then not Comes_From_Source (N)
667 Set_Etype (N, Implementation_Base_Type (P_Type));
669 -- Array types other than string literal subtypes handled above
674 -- We know prefix is an array type, or the name of an array
675 -- object, and that the expression, if present, is static
676 -- and within the range of the dimensions of the type.
678 pragma Assert (Is_Array_Type (P_Type));
679 Index := First_Index (P_Base_Type);
683 -- First dimension assumed
685 Set_Etype (N, Base_Type (Etype (Index)));
688 D := UI_To_Int (Intval (E1));
690 for J in 1 .. D - 1 loop
694 Set_Etype (N, Base_Type (Etype (Index)));
695 Set_Etype (E1, Standard_Integer);
698 end Check_Array_Or_Scalar_Type;
700 ----------------------
701 -- Check_Array_Type --
702 ----------------------
704 procedure Check_Array_Type is
706 -- Dimension number for array attributes.
709 -- If the type is a string literal type, then this must be generated
710 -- internally, and no further check is required on its legality.
712 if Ekind (P_Type) = E_String_Literal_Subtype then
715 -- If the type is a composite, it is an illegal aggregate, no point
718 elsif P_Type = Any_Composite then
722 -- Normal case of array type or subtype
724 Check_Either_E0_Or_E1;
727 if Is_Array_Type (P_Type) then
728 if not Is_Constrained (P_Type)
729 and then Is_Entity_Name (P)
730 and then Is_Type (Entity (P))
732 -- Note: we do not call Error_Attr here, since we prefer to
733 -- continue, using the relevant index type of the array,
734 -- even though it is unconstrained. This gives better error
735 -- recovery behavior.
737 Error_Msg_Name_1 := Aname;
739 ("prefix for % attribute must be constrained array", P);
742 D := Number_Dimensions (P_Type);
745 if Is_Private_Type (P_Type) then
747 ("prefix for % attribute may not be private type", P);
749 elsif Is_Access_Type (P_Type)
750 and then Is_Array_Type (Designated_Type (P_Type))
751 and then Is_Entity_Name (P)
752 and then Is_Type (Entity (P))
754 Error_Attr ("prefix of % attribute cannot be access type", P);
756 elsif Attr_Id = Attribute_First
758 Attr_Id = Attribute_Last
760 Error_Attr ("invalid prefix for % attribute", P);
763 Error_Attr ("prefix for % attribute must be array", P);
768 Resolve (E1, Any_Integer);
769 Set_Etype (E1, Standard_Integer);
771 if not Is_Static_Expression (E1)
772 or else Raises_Constraint_Error (E1)
775 ("expression for dimension must be static!", E1);
778 elsif UI_To_Int (Expr_Value (E1)) > D
779 or else UI_To_Int (Expr_Value (E1)) < 1
781 Error_Attr ("invalid dimension number for array type", E1);
784 end Check_Array_Type;
786 -------------------------
787 -- Check_Asm_Attribute --
788 -------------------------
790 procedure Check_Asm_Attribute is
795 -- Check first argument is static string expression
797 Analyze_And_Resolve (E1, Standard_String);
799 if Etype (E1) = Any_Type then
802 elsif not Is_OK_Static_Expression (E1) then
804 ("constraint argument must be static string expression!", E1);
808 -- Check second argument is right type
810 Analyze_And_Resolve (E2, Entity (P));
812 -- Note: that is all we need to do, we don't need to check
813 -- that it appears in a correct context. The Ada type system
814 -- will do that for us.
816 end Check_Asm_Attribute;
818 ---------------------
819 -- Check_Component --
820 ---------------------
822 procedure Check_Component is
826 if Nkind (P) /= N_Selected_Component
828 (Ekind (Entity (Selector_Name (P))) /= E_Component
830 Ekind (Entity (Selector_Name (P))) /= E_Discriminant)
833 ("prefix for % attribute must be selected component", P);
837 ------------------------------------
838 -- Check_Decimal_Fixed_Point_Type --
839 ------------------------------------
841 procedure Check_Decimal_Fixed_Point_Type is
845 if not Is_Decimal_Fixed_Point_Type (P_Type) then
847 ("prefix of % attribute must be decimal type", P);
849 end Check_Decimal_Fixed_Point_Type;
851 -----------------------
852 -- Check_Dereference --
853 -----------------------
855 procedure Check_Dereference is
858 -- Case of a subtype mark
860 if Is_Entity_Name (P)
861 and then Is_Type (Entity (P))
866 -- Case of an expression
870 if Is_Access_Type (P_Type) then
872 -- If there is an implicit dereference, then we must freeze
873 -- the designated type of the access type, since the type of
874 -- the referenced array is this type (see AI95-00106).
876 Freeze_Before (N, Designated_Type (P_Type));
879 Make_Explicit_Dereference (Sloc (P),
880 Prefix => Relocate_Node (P)));
882 Analyze_And_Resolve (P);
885 if P_Type = Any_Type then
889 P_Base_Type := Base_Type (P_Type);
891 end Check_Dereference;
893 -------------------------
894 -- Check_Discrete_Type --
895 -------------------------
897 procedure Check_Discrete_Type is
901 if not Is_Discrete_Type (P_Type) then
902 Error_Attr ("prefix of % attribute must be discrete type", P);
904 end Check_Discrete_Type;
910 procedure Check_E0 is
913 Unexpected_Argument (E1);
921 procedure Check_E1 is
923 Check_Either_E0_Or_E1;
927 -- Special-case attributes that are functions and that appear as
928 -- the prefix of another attribute. Error is posted on parent.
930 if Nkind (Parent (N)) = N_Attribute_Reference
931 and then (Attribute_Name (Parent (N)) = Name_Address
933 Attribute_Name (Parent (N)) = Name_Code_Address
935 Attribute_Name (Parent (N)) = Name_Access)
937 Error_Msg_Name_1 := Attribute_Name (Parent (N));
938 Error_Msg_N ("illegal prefix for % attribute", Parent (N));
939 Set_Etype (Parent (N), Any_Type);
940 Set_Entity (Parent (N), Any_Type);
944 Error_Attr ("missing argument for % attribute", N);
953 procedure Check_E2 is
956 Error_Attr ("missing arguments for % attribute (2 required)", N);
958 Error_Attr ("missing argument for % attribute (2 required)", N);
962 ---------------------------
963 -- Check_Either_E0_Or_E1 --
964 ---------------------------
966 procedure Check_Either_E0_Or_E1 is
969 Unexpected_Argument (E2);
971 end Check_Either_E0_Or_E1;
973 ----------------------
974 -- Check_Enum_Image --
975 ----------------------
977 procedure Check_Enum_Image is
981 if Is_Enumeration_Type (P_Base_Type) then
982 Lit := First_Literal (P_Base_Type);
983 while Present (Lit) loop
984 Set_Referenced (Lit);
988 end Check_Enum_Image;
990 ----------------------------
991 -- Check_Fixed_Point_Type --
992 ----------------------------
994 procedure Check_Fixed_Point_Type is
998 if not Is_Fixed_Point_Type (P_Type) then
999 Error_Attr ("prefix of % attribute must be fixed point type", P);
1001 end Check_Fixed_Point_Type;
1003 ------------------------------
1004 -- Check_Fixed_Point_Type_0 --
1005 ------------------------------
1007 procedure Check_Fixed_Point_Type_0 is
1009 Check_Fixed_Point_Type;
1011 end Check_Fixed_Point_Type_0;
1013 -------------------------------
1014 -- Check_Floating_Point_Type --
1015 -------------------------------
1017 procedure Check_Floating_Point_Type is
1021 if not Is_Floating_Point_Type (P_Type) then
1022 Error_Attr ("prefix of % attribute must be float type", P);
1024 end Check_Floating_Point_Type;
1026 ---------------------------------
1027 -- Check_Floating_Point_Type_0 --
1028 ---------------------------------
1030 procedure Check_Floating_Point_Type_0 is
1032 Check_Floating_Point_Type;
1034 end Check_Floating_Point_Type_0;
1036 ---------------------------------
1037 -- Check_Floating_Point_Type_1 --
1038 ---------------------------------
1040 procedure Check_Floating_Point_Type_1 is
1042 Check_Floating_Point_Type;
1044 end Check_Floating_Point_Type_1;
1046 ---------------------------------
1047 -- Check_Floating_Point_Type_2 --
1048 ---------------------------------
1050 procedure Check_Floating_Point_Type_2 is
1052 Check_Floating_Point_Type;
1054 end Check_Floating_Point_Type_2;
1056 ------------------------
1057 -- Check_Integer_Type --
1058 ------------------------
1060 procedure Check_Integer_Type is
1064 if not Is_Integer_Type (P_Type) then
1065 Error_Attr ("prefix of % attribute must be integer type", P);
1067 end Check_Integer_Type;
1069 ------------------------
1070 -- Check_Library_Unit --
1071 ------------------------
1073 procedure Check_Library_Unit is
1075 if not Is_Compilation_Unit (Entity (P)) then
1076 Error_Attr ("prefix of % attribute must be library unit", P);
1078 end Check_Library_Unit;
1080 --------------------------------
1081 -- Check_Modular_Integer_Type --
1082 --------------------------------
1084 procedure Check_Modular_Integer_Type is
1088 if not Is_Modular_Integer_Type (P_Type) then
1090 ("prefix of % attribute must be modular integer type", P);
1092 end Check_Modular_Integer_Type;
1094 -------------------------------
1095 -- Check_Not_Incomplete_Type --
1096 -------------------------------
1098 procedure Check_Not_Incomplete_Type is
1100 if not Is_Entity_Name (P)
1101 or else not Is_Type (Entity (P))
1102 or else In_Default_Expression
1107 Check_Fully_Declared (P_Type, P);
1109 end Check_Not_Incomplete_Type;
1111 ----------------------------
1112 -- Check_Object_Reference --
1113 ----------------------------
1115 procedure Check_Object_Reference (P : Node_Id) is
1119 -- If we need an object, and we have a prefix that is the name of
1120 -- a function entity, convert it into a function call.
1122 if Is_Entity_Name (P)
1123 and then Ekind (Entity (P)) = E_Function
1125 Rtyp := Etype (Entity (P));
1128 Make_Function_Call (Sloc (P),
1129 Name => Relocate_Node (P)));
1131 Analyze_And_Resolve (P, Rtyp);
1133 -- Otherwise we must have an object reference
1135 elsif not Is_Object_Reference (P) then
1136 Error_Attr ("prefix of % attribute must be object", P);
1138 end Check_Object_Reference;
1140 ------------------------
1141 -- Check_Program_Unit --
1142 ------------------------
1144 procedure Check_Program_Unit is
1146 if Is_Entity_Name (P) then
1148 K : constant Entity_Kind := Ekind (Entity (P));
1149 T : constant Entity_Id := Etype (Entity (P));
1152 if K in Subprogram_Kind
1153 or else K in Task_Kind
1154 or else K in Protected_Kind
1155 or else K = E_Package
1156 or else K in Generic_Unit_Kind
1157 or else (K = E_Variable
1161 Is_Protected_Type (T)))
1168 Error_Attr ("prefix of % attribute must be program unit", P);
1169 end Check_Program_Unit;
1171 ---------------------
1172 -- Check_Real_Type --
1173 ---------------------
1175 procedure Check_Real_Type is
1179 if not Is_Real_Type (P_Type) then
1180 Error_Attr ("prefix of % attribute must be real type", P);
1182 end Check_Real_Type;
1184 -----------------------
1185 -- Check_Scalar_Type --
1186 -----------------------
1188 procedure Check_Scalar_Type is
1192 if not Is_Scalar_Type (P_Type) then
1193 Error_Attr ("prefix of % attribute must be scalar type", P);
1195 end Check_Scalar_Type;
1197 ---------------------------
1198 -- Check_Standard_Prefix --
1199 ---------------------------
1201 procedure Check_Standard_Prefix is
1205 if Nkind (P) /= N_Identifier
1206 or else Chars (P) /= Name_Standard
1208 Error_Attr ("only allowed prefix for % attribute is Standard", P);
1211 end Check_Standard_Prefix;
1213 ----------------------------
1214 -- Check_Stream_Attribute --
1215 ----------------------------
1217 procedure Check_Stream_Attribute (Nam : TSS_Name_Type) is
1222 Validate_Non_Static_Attribute_Function_Call;
1224 -- With the exception of 'Input, Stream attributes are procedures,
1225 -- and can only appear at the position of procedure calls. We check
1226 -- for this here, before they are rewritten, to give a more precise
1229 if Nam = TSS_Stream_Input then
1232 elsif Is_List_Member (N)
1233 and then Nkind (Parent (N)) /= N_Procedure_Call_Statement
1234 and then Nkind (Parent (N)) /= N_Aggregate
1240 ("invalid context for attribute%, which is a procedure", N);
1244 Btyp := Implementation_Base_Type (P_Type);
1246 -- Stream attributes not allowed on limited types unless the
1247 -- attribute reference was generated by the expander (in which
1248 -- case the underlying type will be used, as described in Sinfo),
1249 -- or the attribute was specified explicitly for the type itself
1250 -- or one of its ancestors.
1252 if Is_Limited_Type (P_Type)
1253 and then Comes_From_Source (N)
1254 and then not Present (Find_Inherited_TSS (Btyp, Nam))
1255 and then not Has_Rep_Pragma (Btyp, Name_Stream_Convert)
1257 Error_Msg_Name_1 := Aname;
1259 ("limited type& has no% attribute", P, Btyp);
1260 Explain_Limited_Type (P_Type, P);
1263 -- Check for violation of restriction No_Stream_Attributes
1265 if Is_RTE (P_Type, RE_Exception_Id)
1267 Is_RTE (P_Type, RE_Exception_Occurrence)
1269 Check_Restriction (No_Exception_Registration, P);
1272 -- Here we must check that the first argument is an access type
1273 -- that is compatible with Ada.Streams.Root_Stream_Type'Class.
1275 Analyze_And_Resolve (E1);
1278 -- Note: the double call to Root_Type here is needed because the
1279 -- root type of a class-wide type is the corresponding type (e.g.
1280 -- X for X'Class, and we really want to go to the root.
1282 if not Is_Access_Type (Etyp)
1283 or else Root_Type (Root_Type (Designated_Type (Etyp))) /=
1284 RTE (RE_Root_Stream_Type)
1287 ("expected access to Ada.Streams.Root_Stream_Type''Class", E1);
1290 -- Check that the second argument is of the right type if there is
1291 -- one (the Input attribute has only one argument so this is skipped)
1293 if Present (E2) then
1296 if Nam = TSS_Stream_Read
1297 and then not Is_OK_Variable_For_Out_Formal (E2)
1300 ("second argument of % attribute must be a variable", E2);
1303 Resolve (E2, P_Type);
1305 end Check_Stream_Attribute;
1307 -----------------------
1308 -- Check_Task_Prefix --
1309 -----------------------
1311 procedure Check_Task_Prefix is
1315 if Is_Task_Type (Etype (P))
1316 or else (Is_Access_Type (Etype (P))
1317 and then Is_Task_Type (Designated_Type (Etype (P))))
1321 Error_Attr ("prefix of % attribute must be a task", P);
1323 end Check_Task_Prefix;
1329 -- The possibilities are an entity name denoting a type, or an
1330 -- attribute reference that denotes a type (Base or Class). If
1331 -- the type is incomplete, replace it with its full view.
1333 procedure Check_Type is
1335 if not Is_Entity_Name (P)
1336 or else not Is_Type (Entity (P))
1338 Error_Attr ("prefix of % attribute must be a type", P);
1340 elsif Ekind (Entity (P)) = E_Incomplete_Type
1341 and then Present (Full_View (Entity (P)))
1343 P_Type := Full_View (Entity (P));
1344 Set_Entity (P, P_Type);
1348 ---------------------
1349 -- Check_Unit_Name --
1350 ---------------------
1352 procedure Check_Unit_Name (Nod : Node_Id) is
1354 if Nkind (Nod) = N_Identifier then
1357 elsif Nkind (Nod) = N_Selected_Component then
1358 Check_Unit_Name (Prefix (Nod));
1360 if Nkind (Selector_Name (Nod)) = N_Identifier then
1365 Error_Attr ("argument for % attribute must be unit name", P);
1366 end Check_Unit_Name;
1372 procedure Error_Attr is
1374 Set_Etype (N, Any_Type);
1375 Set_Entity (N, Any_Type);
1376 raise Bad_Attribute;
1379 procedure Error_Attr (Msg : String; Error_Node : Node_Id) is
1381 Error_Msg_Name_1 := Aname;
1382 Error_Msg_N (Msg, Error_Node);
1386 ----------------------------
1387 -- Legal_Formal_Attribute --
1388 ----------------------------
1390 procedure Legal_Formal_Attribute is
1394 if not Is_Entity_Name (P)
1395 or else not Is_Type (Entity (P))
1397 Error_Attr ("prefix of % attribute must be generic type", N);
1399 elsif Is_Generic_Actual_Type (Entity (P))
1401 or else In_Inlined_Body
1405 elsif Is_Generic_Type (Entity (P)) then
1406 if not Is_Indefinite_Subtype (Entity (P)) then
1408 ("prefix of % attribute must be indefinite generic type", N);
1413 ("prefix of % attribute must be indefinite generic type", N);
1416 Set_Etype (N, Standard_Boolean);
1417 end Legal_Formal_Attribute;
1419 ------------------------
1420 -- Standard_Attribute --
1421 ------------------------
1423 procedure Standard_Attribute (Val : Int) is
1425 Check_Standard_Prefix;
1427 -- First a special check (more like a kludge really). For GNAT5
1428 -- on Windows, the alignments in GCC are severely mixed up. In
1429 -- particular, we have a situation where the maximum alignment
1430 -- that GCC thinks is possible is greater than the guaranteed
1431 -- alignment at run-time. That causes many problems. As a partial
1432 -- cure for this situation, we force a value of 4 for the maximum
1433 -- alignment attribute on this target. This still does not solve
1434 -- all problems, but it helps.
1436 -- A further (even more horrible) dimension to this kludge is now
1437 -- installed. There are two uses for Maximum_Alignment, one is to
1438 -- determine the maximum guaranteed alignment, that's the one we
1439 -- want the kludge to yield as 4. The other use is to maximally
1440 -- align objects, we can't use 4 here, since for example, long
1441 -- long integer has an alignment of 8, so we will get errors.
1443 -- It is of course impossible to determine which use the programmer
1444 -- has in mind, but an approximation for now is to disconnect the
1445 -- kludge if the attribute appears in an alignment clause.
1447 -- To be removed if GCC ever gets its act together here ???
1449 Alignment_Kludge : declare
1452 function On_X86 return Boolean;
1453 -- Determine if target is x86 (ia32), return True if so
1459 function On_X86 return Boolean is
1460 T : constant String := Sdefault.Target_Name.all;
1463 -- There is no clean way to check this. That's not surprising,
1464 -- the front end should not be doing this kind of test ???. The
1465 -- way we do it is test for either "86" or "pentium" being in
1466 -- the string for the target name. However, we need to exclude
1467 -- x86_64 for this check.
1469 for J in T'First .. T'Last - 1 loop
1470 if (T (J .. J + 1) = "86"
1473 or else T (J + 2 .. J + 4) /= "_64"))
1474 or else (J <= T'Last - 6
1475 and then T (J .. J + 6) = "pentium")
1485 if Aname = Name_Maximum_Alignment and then On_X86 then
1488 while Nkind (P) in N_Subexpr loop
1492 if Nkind (P) /= N_Attribute_Definition_Clause
1493 or else Chars (P) /= Name_Alignment
1495 Rewrite (N, Make_Integer_Literal (Loc, 4));
1500 end Alignment_Kludge;
1502 -- Normally we get the value from gcc ???
1504 Rewrite (N, Make_Integer_Literal (Loc, Val));
1506 end Standard_Attribute;
1508 -------------------------
1509 -- Unexpected Argument --
1510 -------------------------
1512 procedure Unexpected_Argument (En : Node_Id) is
1514 Error_Attr ("unexpected argument for % attribute", En);
1515 end Unexpected_Argument;
1517 -------------------------------------------------
1518 -- Validate_Non_Static_Attribute_Function_Call --
1519 -------------------------------------------------
1521 -- This function should be moved to Sem_Dist ???
1523 procedure Validate_Non_Static_Attribute_Function_Call is
1525 if In_Preelaborated_Unit
1526 and then not In_Subprogram_Or_Concurrent_Unit
1528 Flag_Non_Static_Expr
1529 ("non-static function call in preelaborated unit!", N);
1531 end Validate_Non_Static_Attribute_Function_Call;
1533 -----------------------------------------------
1534 -- Start of Processing for Analyze_Attribute --
1535 -----------------------------------------------
1538 -- Immediate return if unrecognized attribute (already diagnosed
1539 -- by parser, so there is nothing more that we need to do)
1541 if not Is_Attribute_Name (Aname) then
1542 raise Bad_Attribute;
1545 -- Deal with Ada 83 and Features issues
1547 if Comes_From_Source (N) then
1548 if not Attribute_83 (Attr_Id) then
1549 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1550 Error_Msg_Name_1 := Aname;
1551 Error_Msg_N ("(Ada 83) attribute% is not standard?", N);
1554 if Attribute_Impl_Def (Attr_Id) then
1555 Check_Restriction (No_Implementation_Attributes, N);
1560 -- Remote access to subprogram type access attribute reference needs
1561 -- unanalyzed copy for tree transformation. The analyzed copy is used
1562 -- for its semantic information (whether prefix is a remote subprogram
1563 -- name), the unanalyzed copy is used to construct new subtree rooted
1564 -- with N_Aggregate which represents a fat pointer aggregate.
1566 if Aname = Name_Access then
1567 Discard_Node (Copy_Separate_Tree (N));
1570 -- Analyze prefix and exit if error in analysis. If the prefix is an
1571 -- incomplete type, use full view if available. A special case is
1572 -- that we never analyze the prefix of an Elab_Body or Elab_Spec
1573 -- or UET_Address attribute.
1575 if Aname /= Name_Elab_Body
1577 Aname /= Name_Elab_Spec
1579 Aname /= Name_UET_Address
1582 P_Type := Etype (P);
1584 if Is_Entity_Name (P)
1585 and then Present (Entity (P))
1586 and then Is_Type (Entity (P))
1587 and then Ekind (Entity (P)) = E_Incomplete_Type
1589 P_Type := Get_Full_View (P_Type);
1590 Set_Entity (P, P_Type);
1591 Set_Etype (P, P_Type);
1594 if P_Type = Any_Type then
1595 raise Bad_Attribute;
1598 P_Base_Type := Base_Type (P_Type);
1601 -- Analyze expressions that may be present, exiting if an error occurs
1608 E1 := First (Exprs);
1611 -- Check for missing or bad expression (result of previous error)
1613 if No (E1) or else Etype (E1) = Any_Type then
1614 raise Bad_Attribute;
1619 if Present (E2) then
1622 if Etype (E2) = Any_Type then
1623 raise Bad_Attribute;
1626 if Present (Next (E2)) then
1627 Unexpected_Argument (Next (E2));
1632 if Is_Overloaded (P)
1633 and then Aname /= Name_Access
1634 and then Aname /= Name_Address
1635 and then Aname /= Name_Code_Address
1636 and then Aname /= Name_Count
1637 and then Aname /= Name_Unchecked_Access
1639 Error_Attr ("ambiguous prefix for % attribute", P);
1642 -- Remaining processing depends on attribute
1650 when Attribute_Abort_Signal =>
1651 Check_Standard_Prefix;
1653 New_Reference_To (Stand.Abort_Signal, Loc));
1660 when Attribute_Access =>
1661 Analyze_Access_Attribute;
1667 when Attribute_Address =>
1670 -- Check for some junk cases, where we have to allow the address
1671 -- attribute but it does not make much sense, so at least for now
1672 -- just replace with Null_Address.
1674 -- We also do this if the prefix is a reference to the AST_Entry
1675 -- attribute. If expansion is active, the attribute will be
1676 -- replaced by a function call, and address will work fine and
1677 -- get the proper value, but if expansion is not active, then
1678 -- the check here allows proper semantic analysis of the reference.
1680 -- An Address attribute created by expansion is legal even when it
1681 -- applies to other entity-denoting expressions.
1683 if Is_Entity_Name (P) then
1685 Ent : constant Entity_Id := Entity (P);
1688 if Is_Subprogram (Ent) then
1689 if not Is_Library_Level_Entity (Ent) then
1690 Check_Restriction (No_Implicit_Dynamic_Code, P);
1693 Set_Address_Taken (Ent);
1695 elsif Is_Object (Ent)
1696 or else Ekind (Ent) = E_Label
1698 Set_Address_Taken (Ent);
1700 -- If we have an address of an object, and the attribute
1701 -- comes from source, then set the object as potentially
1702 -- source modified. We do this because the resulting address
1703 -- can potentially be used to modify the variable and we
1704 -- might not detect this, leading to some junk warnings.
1706 Set_Never_Set_In_Source (Ent, False);
1708 elsif (Is_Concurrent_Type (Etype (Ent))
1709 and then Etype (Ent) = Base_Type (Ent))
1710 or else Ekind (Ent) = E_Package
1711 or else Is_Generic_Unit (Ent)
1714 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
1717 Error_Attr ("invalid prefix for % attribute", P);
1721 elsif Nkind (P) = N_Attribute_Reference
1722 and then Attribute_Name (P) = Name_AST_Entry
1725 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
1727 elsif Is_Object_Reference (P) then
1730 elsif Nkind (P) = N_Selected_Component
1731 and then Is_Subprogram (Entity (Selector_Name (P)))
1735 -- What exactly are we allowing here ??? and is this properly
1736 -- documented in the sinfo documentation for this node ???
1738 elsif not Comes_From_Source (N) then
1742 Error_Attr ("invalid prefix for % attribute", P);
1745 Set_Etype (N, RTE (RE_Address));
1751 when Attribute_Address_Size =>
1752 Standard_Attribute (System_Address_Size);
1758 when Attribute_Adjacent =>
1759 Check_Floating_Point_Type_2;
1760 Set_Etype (N, P_Base_Type);
1761 Resolve (E1, P_Base_Type);
1762 Resolve (E2, P_Base_Type);
1768 when Attribute_Aft =>
1769 Check_Fixed_Point_Type_0;
1770 Set_Etype (N, Universal_Integer);
1776 when Attribute_Alignment =>
1778 -- Don't we need more checking here, cf Size ???
1781 Check_Not_Incomplete_Type;
1782 Set_Etype (N, Universal_Integer);
1788 when Attribute_Asm_Input =>
1789 Check_Asm_Attribute;
1790 Set_Etype (N, RTE (RE_Asm_Input_Operand));
1796 when Attribute_Asm_Output =>
1797 Check_Asm_Attribute;
1799 if Etype (E2) = Any_Type then
1802 elsif Aname = Name_Asm_Output then
1803 if not Is_Variable (E2) then
1805 ("second argument for Asm_Output is not variable", E2);
1809 Note_Possible_Modification (E2);
1810 Set_Etype (N, RTE (RE_Asm_Output_Operand));
1816 when Attribute_AST_Entry => AST_Entry : declare
1822 -- Indicates if entry family index is present. Note the coding
1823 -- here handles the entry family case, but in fact it cannot be
1824 -- executed currently, because pragma AST_Entry does not permit
1825 -- the specification of an entry family.
1827 procedure Bad_AST_Entry;
1828 -- Signal a bad AST_Entry pragma
1830 function OK_Entry (E : Entity_Id) return Boolean;
1831 -- Checks that E is of an appropriate entity kind for an entry
1832 -- (i.e. E_Entry if Index is False, or E_Entry_Family if Index
1833 -- is set True for the entry family case). In the True case,
1834 -- makes sure that Is_AST_Entry is set on the entry.
1836 procedure Bad_AST_Entry is
1838 Error_Attr ("prefix for % attribute must be task entry", P);
1841 function OK_Entry (E : Entity_Id) return Boolean is
1846 Result := (Ekind (E) = E_Entry_Family);
1848 Result := (Ekind (E) = E_Entry);
1852 if not Is_AST_Entry (E) then
1853 Error_Msg_Name_2 := Aname;
1855 ("% attribute requires previous % pragma", P);
1862 -- Start of processing for AST_Entry
1868 -- Deal with entry family case
1870 if Nkind (P) = N_Indexed_Component then
1878 Ptyp := Etype (Pref);
1880 if Ptyp = Any_Type or else Error_Posted (Pref) then
1884 -- If the prefix is a selected component whose prefix is of an
1885 -- access type, then introduce an explicit dereference.
1886 -- ??? Could we reuse Check_Dereference here?
1888 if Nkind (Pref) = N_Selected_Component
1889 and then Is_Access_Type (Ptyp)
1892 Make_Explicit_Dereference (Sloc (Pref),
1893 Relocate_Node (Pref)));
1894 Analyze_And_Resolve (Pref, Designated_Type (Ptyp));
1897 -- Prefix can be of the form a.b, where a is a task object
1898 -- and b is one of the entries of the corresponding task type.
1900 if Nkind (Pref) = N_Selected_Component
1901 and then OK_Entry (Entity (Selector_Name (Pref)))
1902 and then Is_Object_Reference (Prefix (Pref))
1903 and then Is_Task_Type (Etype (Prefix (Pref)))
1907 -- Otherwise the prefix must be an entry of a containing task,
1908 -- or of a variable of the enclosing task type.
1911 if Nkind (Pref) = N_Identifier
1912 or else Nkind (Pref) = N_Expanded_Name
1914 Ent := Entity (Pref);
1916 if not OK_Entry (Ent)
1917 or else not In_Open_Scopes (Scope (Ent))
1927 Set_Etype (N, RTE (RE_AST_Handler));
1934 -- Note: when the base attribute appears in the context of a subtype
1935 -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by
1936 -- the following circuit.
1938 when Attribute_Base => Base : declare
1942 Check_Either_E0_Or_E1;
1946 if Ada_Version >= Ada_95
1947 and then not Is_Scalar_Type (Typ)
1948 and then not Is_Generic_Type (Typ)
1950 Error_Msg_N ("prefix of Base attribute must be scalar type", N);
1952 elsif Sloc (Typ) = Standard_Location
1953 and then Base_Type (Typ) = Typ
1954 and then Warn_On_Redundant_Constructs
1957 ("?redudant attribute, & is its own base type", N, Typ);
1960 Set_Etype (N, Base_Type (Entity (P)));
1962 -- If we have an expression present, then really this is a conversion
1963 -- and the tree must be reformed. Note that this is one of the cases
1964 -- in which we do a replace rather than a rewrite, because the
1965 -- original tree is junk.
1967 if Present (E1) then
1969 Make_Type_Conversion (Loc,
1971 Make_Attribute_Reference (Loc,
1972 Prefix => Prefix (N),
1973 Attribute_Name => Name_Base),
1974 Expression => Relocate_Node (E1)));
1976 -- E1 may be overloaded, and its interpretations preserved.
1978 Save_Interps (E1, Expression (N));
1981 -- For other cases, set the proper type as the entity of the
1982 -- attribute reference, and then rewrite the node to be an
1983 -- occurrence of the referenced base type. This way, no one
1984 -- else in the compiler has to worry about the base attribute.
1987 Set_Entity (N, Base_Type (Entity (P)));
1989 New_Reference_To (Entity (N), Loc));
1998 when Attribute_Bit => Bit :
2002 if not Is_Object_Reference (P) then
2003 Error_Attr ("prefix for % attribute must be object", P);
2005 -- What about the access object cases ???
2011 Set_Etype (N, Universal_Integer);
2018 when Attribute_Bit_Order => Bit_Order :
2023 if not Is_Record_Type (P_Type) then
2024 Error_Attr ("prefix of % attribute must be record type", P);
2027 if Bytes_Big_Endian xor Reverse_Bit_Order (P_Type) then
2029 New_Occurrence_Of (RTE (RE_High_Order_First), Loc));
2032 New_Occurrence_Of (RTE (RE_Low_Order_First), Loc));
2035 Set_Etype (N, RTE (RE_Bit_Order));
2038 -- Reset incorrect indication of staticness
2040 Set_Is_Static_Expression (N, False);
2047 -- Note: in generated code, we can have a Bit_Position attribute
2048 -- applied to a (naked) record component (i.e. the prefix is an
2049 -- identifier that references an E_Component or E_Discriminant
2050 -- entity directly, and this is interpreted as expected by Gigi.
2051 -- The following code will not tolerate such usage, but when the
2052 -- expander creates this special case, it marks it as analyzed
2053 -- immediately and sets an appropriate type.
2055 when Attribute_Bit_Position =>
2057 if Comes_From_Source (N) then
2061 Set_Etype (N, Universal_Integer);
2067 when Attribute_Body_Version =>
2070 Set_Etype (N, RTE (RE_Version_String));
2076 when Attribute_Callable =>
2078 Set_Etype (N, Standard_Boolean);
2085 when Attribute_Caller => Caller : declare
2092 if Nkind (P) = N_Identifier
2093 or else Nkind (P) = N_Expanded_Name
2097 if not Is_Entry (Ent) then
2098 Error_Attr ("invalid entry name", N);
2102 Error_Attr ("invalid entry name", N);
2106 for J in reverse 0 .. Scope_Stack.Last loop
2107 S := Scope_Stack.Table (J).Entity;
2109 if S = Scope (Ent) then
2110 Error_Attr ("Caller must appear in matching accept or body", N);
2116 Set_Etype (N, RTE (RO_AT_Task_Id));
2123 when Attribute_Ceiling =>
2124 Check_Floating_Point_Type_1;
2125 Set_Etype (N, P_Base_Type);
2126 Resolve (E1, P_Base_Type);
2132 when Attribute_Class => Class : declare
2134 Check_Restriction (No_Dispatch, N);
2135 Check_Either_E0_Or_E1;
2137 -- If we have an expression present, then really this is a conversion
2138 -- and the tree must be reformed into a proper conversion. This is a
2139 -- Replace rather than a Rewrite, because the original tree is junk.
2140 -- If expression is overloaded, propagate interpretations to new one.
2142 if Present (E1) then
2144 Make_Type_Conversion (Loc,
2146 Make_Attribute_Reference (Loc,
2147 Prefix => Prefix (N),
2148 Attribute_Name => Name_Class),
2149 Expression => Relocate_Node (E1)));
2151 Save_Interps (E1, Expression (N));
2154 -- Otherwise we just need to find the proper type
2166 when Attribute_Code_Address =>
2169 if Nkind (P) = N_Attribute_Reference
2170 and then (Attribute_Name (P) = Name_Elab_Body
2172 Attribute_Name (P) = Name_Elab_Spec)
2176 elsif not Is_Entity_Name (P)
2177 or else (Ekind (Entity (P)) /= E_Function
2179 Ekind (Entity (P)) /= E_Procedure)
2181 Error_Attr ("invalid prefix for % attribute", P);
2182 Set_Address_Taken (Entity (P));
2185 Set_Etype (N, RTE (RE_Address));
2187 --------------------
2188 -- Component_Size --
2189 --------------------
2191 when Attribute_Component_Size =>
2193 Set_Etype (N, Universal_Integer);
2195 -- Note: unlike other array attributes, unconstrained arrays are OK
2197 if Is_Array_Type (P_Type) and then not Is_Constrained (P_Type) then
2207 when Attribute_Compose =>
2208 Check_Floating_Point_Type_2;
2209 Set_Etype (N, P_Base_Type);
2210 Resolve (E1, P_Base_Type);
2211 Resolve (E2, Any_Integer);
2217 when Attribute_Constrained =>
2219 Set_Etype (N, Standard_Boolean);
2221 -- Case from RM J.4(2) of constrained applied to private type
2223 if Is_Entity_Name (P) and then Is_Type (Entity (P)) then
2224 Check_Restriction (No_Obsolescent_Features, N);
2226 if Warn_On_Obsolescent_Feature then
2228 ("constrained for private type is an " &
2229 "obsolescent feature ('R'M 'J.4)?", N);
2232 -- If we are within an instance, the attribute must be legal
2233 -- because it was valid in the generic unit. Ditto if this is
2234 -- an inlining of a function declared in an instance.
2237 or else In_Inlined_Body
2241 -- For sure OK if we have a real private type itself, but must
2242 -- be completed, cannot apply Constrained to incomplete type.
2244 elsif Is_Private_Type (Entity (P)) then
2246 -- Note: this is one of the Annex J features that does not
2247 -- generate a warning from -gnatwj, since in fact it seems
2248 -- very useful, and is used in the GNAT runtime.
2250 Check_Not_Incomplete_Type;
2254 -- Normal (non-obsolescent case) of application to object of
2255 -- a discriminated type.
2258 Check_Object_Reference (P);
2260 -- If N does not come from source, then we allow the
2261 -- the attribute prefix to be of a private type whose
2262 -- full type has discriminants. This occurs in cases
2263 -- involving expanded calls to stream attributes.
2265 if not Comes_From_Source (N) then
2266 P_Type := Underlying_Type (P_Type);
2269 -- Must have discriminants or be an access type designating
2270 -- a type with discriminants. If it is a classwide type is
2271 -- has unknown discriminants.
2273 if Has_Discriminants (P_Type)
2274 or else Has_Unknown_Discriminants (P_Type)
2276 (Is_Access_Type (P_Type)
2277 and then Has_Discriminants (Designated_Type (P_Type)))
2281 -- Also allow an object of a generic type if extensions allowed
2282 -- and allow this for any type at all.
2284 elsif (Is_Generic_Type (P_Type)
2285 or else Is_Generic_Actual_Type (P_Type))
2286 and then Extensions_Allowed
2292 -- Fall through if bad prefix
2295 ("prefix of % attribute must be object of discriminated type", P);
2301 when Attribute_Copy_Sign =>
2302 Check_Floating_Point_Type_2;
2303 Set_Etype (N, P_Base_Type);
2304 Resolve (E1, P_Base_Type);
2305 Resolve (E2, P_Base_Type);
2311 when Attribute_Count => Count :
2320 if Nkind (P) = N_Identifier
2321 or else Nkind (P) = N_Expanded_Name
2325 if Ekind (Ent) /= E_Entry then
2326 Error_Attr ("invalid entry name", N);
2329 elsif Nkind (P) = N_Indexed_Component then
2330 if not Is_Entity_Name (Prefix (P))
2331 or else No (Entity (Prefix (P)))
2332 or else Ekind (Entity (Prefix (P))) /= E_Entry_Family
2334 if Nkind (Prefix (P)) = N_Selected_Component
2335 and then Present (Entity (Selector_Name (Prefix (P))))
2336 and then Ekind (Entity (Selector_Name (Prefix (P)))) =
2340 ("attribute % must apply to entry of current task", P);
2343 Error_Attr ("invalid entry family name", P);
2348 Ent := Entity (Prefix (P));
2351 elsif Nkind (P) = N_Selected_Component
2352 and then Present (Entity (Selector_Name (P)))
2353 and then Ekind (Entity (Selector_Name (P))) = E_Entry
2356 ("attribute % must apply to entry of current task", P);
2359 Error_Attr ("invalid entry name", N);
2363 for J in reverse 0 .. Scope_Stack.Last loop
2364 S := Scope_Stack.Table (J).Entity;
2366 if S = Scope (Ent) then
2367 if Nkind (P) = N_Expanded_Name then
2368 Tsk := Entity (Prefix (P));
2370 -- The prefix denotes either the task type, or else a
2371 -- single task whose task type is being analyzed.
2376 or else (not Is_Type (Tsk)
2377 and then Etype (Tsk) = S
2378 and then not (Comes_From_Source (S)))
2383 ("Attribute % must apply to entry of current task", N);
2389 elsif Ekind (Scope (Ent)) in Task_Kind
2390 and then Ekind (S) /= E_Loop
2391 and then Ekind (S) /= E_Block
2392 and then Ekind (S) /= E_Entry
2393 and then Ekind (S) /= E_Entry_Family
2395 Error_Attr ("Attribute % cannot appear in inner unit", N);
2397 elsif Ekind (Scope (Ent)) = E_Protected_Type
2398 and then not Has_Completion (Scope (Ent))
2400 Error_Attr ("attribute % can only be used inside body", N);
2404 if Is_Overloaded (P) then
2406 Index : Interp_Index;
2410 Get_First_Interp (P, Index, It);
2412 while Present (It.Nam) loop
2413 if It.Nam = Ent then
2417 Error_Attr ("ambiguous entry name", N);
2420 Get_Next_Interp (Index, It);
2425 Set_Etype (N, Universal_Integer);
2428 -----------------------
2429 -- Default_Bit_Order --
2430 -----------------------
2432 when Attribute_Default_Bit_Order => Default_Bit_Order :
2434 Check_Standard_Prefix;
2437 if Bytes_Big_Endian then
2439 Make_Integer_Literal (Loc, False_Value));
2442 Make_Integer_Literal (Loc, True_Value));
2445 Set_Etype (N, Universal_Integer);
2446 Set_Is_Static_Expression (N);
2447 end Default_Bit_Order;
2453 when Attribute_Definite =>
2454 Legal_Formal_Attribute;
2460 when Attribute_Delta =>
2461 Check_Fixed_Point_Type_0;
2462 Set_Etype (N, Universal_Real);
2468 when Attribute_Denorm =>
2469 Check_Floating_Point_Type_0;
2470 Set_Etype (N, Standard_Boolean);
2476 when Attribute_Digits =>
2480 if not Is_Floating_Point_Type (P_Type)
2481 and then not Is_Decimal_Fixed_Point_Type (P_Type)
2484 ("prefix of % attribute must be float or decimal type", P);
2487 Set_Etype (N, Universal_Integer);
2493 -- Also handles processing for Elab_Spec
2495 when Attribute_Elab_Body | Attribute_Elab_Spec =>
2497 Check_Unit_Name (P);
2498 Set_Etype (N, Standard_Void_Type);
2500 -- We have to manually call the expander in this case to get
2501 -- the necessary expansion (normally attributes that return
2502 -- entities are not expanded).
2510 -- Shares processing with Elab_Body
2516 when Attribute_Elaborated =>
2519 Set_Etype (N, Standard_Boolean);
2525 when Attribute_Emax =>
2526 Check_Floating_Point_Type_0;
2527 Set_Etype (N, Universal_Integer);
2533 when Attribute_Enum_Rep => Enum_Rep : declare
2535 if Present (E1) then
2537 Check_Discrete_Type;
2538 Resolve (E1, P_Base_Type);
2541 if not Is_Entity_Name (P)
2542 or else (not Is_Object (Entity (P))
2544 Ekind (Entity (P)) /= E_Enumeration_Literal)
2547 ("prefix of %attribute must be " &
2548 "discrete type/object or enum literal", P);
2552 Set_Etype (N, Universal_Integer);
2559 when Attribute_Epsilon =>
2560 Check_Floating_Point_Type_0;
2561 Set_Etype (N, Universal_Real);
2567 when Attribute_Exponent =>
2568 Check_Floating_Point_Type_1;
2569 Set_Etype (N, Universal_Integer);
2570 Resolve (E1, P_Base_Type);
2576 when Attribute_External_Tag =>
2580 Set_Etype (N, Standard_String);
2582 if not Is_Tagged_Type (P_Type) then
2583 Error_Attr ("prefix of % attribute must be tagged", P);
2590 when Attribute_First =>
2591 Check_Array_Or_Scalar_Type;
2597 when Attribute_First_Bit =>
2599 Set_Etype (N, Universal_Integer);
2605 when Attribute_Fixed_Value =>
2607 Check_Fixed_Point_Type;
2608 Resolve (E1, Any_Integer);
2609 Set_Etype (N, P_Base_Type);
2615 when Attribute_Floor =>
2616 Check_Floating_Point_Type_1;
2617 Set_Etype (N, P_Base_Type);
2618 Resolve (E1, P_Base_Type);
2624 when Attribute_Fore =>
2625 Check_Fixed_Point_Type_0;
2626 Set_Etype (N, Universal_Integer);
2632 when Attribute_Fraction =>
2633 Check_Floating_Point_Type_1;
2634 Set_Etype (N, P_Base_Type);
2635 Resolve (E1, P_Base_Type);
2637 -----------------------
2638 -- Has_Access_Values --
2639 -----------------------
2641 when Attribute_Has_Access_Values =>
2644 Set_Etype (N, Standard_Boolean);
2646 -----------------------
2647 -- Has_Discriminants --
2648 -----------------------
2650 when Attribute_Has_Discriminants =>
2651 Legal_Formal_Attribute;
2657 when Attribute_Identity =>
2661 if Etype (P) = Standard_Exception_Type then
2662 Set_Etype (N, RTE (RE_Exception_Id));
2664 elsif Is_Task_Type (Etype (P))
2665 or else (Is_Access_Type (Etype (P))
2666 and then Is_Task_Type (Designated_Type (Etype (P))))
2669 Set_Etype (N, RTE (RO_AT_Task_Id));
2672 Error_Attr ("prefix of % attribute must be a task or an "
2680 when Attribute_Image => Image :
2682 Set_Etype (N, Standard_String);
2685 if Is_Real_Type (P_Type) then
2686 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
2687 Error_Msg_Name_1 := Aname;
2689 ("(Ada 83) % attribute not allowed for real types", N);
2693 if Is_Enumeration_Type (P_Type) then
2694 Check_Restriction (No_Enumeration_Maps, N);
2698 Resolve (E1, P_Base_Type);
2700 Validate_Non_Static_Attribute_Function_Call;
2707 when Attribute_Img => Img :
2709 Set_Etype (N, Standard_String);
2711 if not Is_Scalar_Type (P_Type)
2712 or else (Is_Entity_Name (P) and then Is_Type (Entity (P)))
2715 ("prefix of % attribute must be scalar object name", N);
2725 when Attribute_Input =>
2727 Check_Stream_Attribute (TSS_Stream_Input);
2728 Set_Etype (N, P_Base_Type);
2734 when Attribute_Integer_Value =>
2737 Resolve (E1, Any_Fixed);
2738 Set_Etype (N, P_Base_Type);
2744 when Attribute_Large =>
2747 Set_Etype (N, Universal_Real);
2753 when Attribute_Last =>
2754 Check_Array_Or_Scalar_Type;
2760 when Attribute_Last_Bit =>
2762 Set_Etype (N, Universal_Integer);
2768 when Attribute_Leading_Part =>
2769 Check_Floating_Point_Type_2;
2770 Set_Etype (N, P_Base_Type);
2771 Resolve (E1, P_Base_Type);
2772 Resolve (E2, Any_Integer);
2778 when Attribute_Length =>
2780 Set_Etype (N, Universal_Integer);
2786 when Attribute_Machine =>
2787 Check_Floating_Point_Type_1;
2788 Set_Etype (N, P_Base_Type);
2789 Resolve (E1, P_Base_Type);
2795 when Attribute_Machine_Emax =>
2796 Check_Floating_Point_Type_0;
2797 Set_Etype (N, Universal_Integer);
2803 when Attribute_Machine_Emin =>
2804 Check_Floating_Point_Type_0;
2805 Set_Etype (N, Universal_Integer);
2807 ----------------------
2808 -- Machine_Mantissa --
2809 ----------------------
2811 when Attribute_Machine_Mantissa =>
2812 Check_Floating_Point_Type_0;
2813 Set_Etype (N, Universal_Integer);
2815 -----------------------
2816 -- Machine_Overflows --
2817 -----------------------
2819 when Attribute_Machine_Overflows =>
2822 Set_Etype (N, Standard_Boolean);
2828 when Attribute_Machine_Radix =>
2831 Set_Etype (N, Universal_Integer);
2833 --------------------
2834 -- Machine_Rounds --
2835 --------------------
2837 when Attribute_Machine_Rounds =>
2840 Set_Etype (N, Standard_Boolean);
2846 when Attribute_Machine_Size =>
2849 Check_Not_Incomplete_Type;
2850 Set_Etype (N, Universal_Integer);
2856 when Attribute_Mantissa =>
2859 Set_Etype (N, Universal_Integer);
2865 when Attribute_Max =>
2868 Resolve (E1, P_Base_Type);
2869 Resolve (E2, P_Base_Type);
2870 Set_Etype (N, P_Base_Type);
2872 ----------------------------------
2873 -- Max_Size_In_Storage_Elements --
2874 ----------------------------------
2876 when Attribute_Max_Size_In_Storage_Elements =>
2879 Check_Not_Incomplete_Type;
2880 Set_Etype (N, Universal_Integer);
2882 -----------------------
2883 -- Maximum_Alignment --
2884 -----------------------
2886 when Attribute_Maximum_Alignment =>
2887 Standard_Attribute (Ttypes.Maximum_Alignment);
2889 --------------------
2890 -- Mechanism_Code --
2891 --------------------
2893 when Attribute_Mechanism_Code =>
2894 if not Is_Entity_Name (P)
2895 or else not Is_Subprogram (Entity (P))
2897 Error_Attr ("prefix of % attribute must be subprogram", P);
2900 Check_Either_E0_Or_E1;
2902 if Present (E1) then
2903 Resolve (E1, Any_Integer);
2904 Set_Etype (E1, Standard_Integer);
2906 if not Is_Static_Expression (E1) then
2907 Flag_Non_Static_Expr
2908 ("expression for parameter number must be static!", E1);
2911 elsif UI_To_Int (Intval (E1)) > Number_Formals (Entity (P))
2912 or else UI_To_Int (Intval (E1)) < 0
2914 Error_Attr ("invalid parameter number for %attribute", E1);
2918 Set_Etype (N, Universal_Integer);
2924 when Attribute_Min =>
2927 Resolve (E1, P_Base_Type);
2928 Resolve (E2, P_Base_Type);
2929 Set_Etype (N, P_Base_Type);
2935 when Attribute_Mod =>
2937 -- Note: this attribute is only allowed in Ada 2005 mode, but
2938 -- we do not need to test that here, since Mod is only recognized
2939 -- as an attribute name in Ada 2005 mode during the parse.
2942 Check_Modular_Integer_Type;
2943 Resolve (E1, Any_Integer);
2944 Set_Etype (N, P_Base_Type);
2950 when Attribute_Model =>
2951 Check_Floating_Point_Type_1;
2952 Set_Etype (N, P_Base_Type);
2953 Resolve (E1, P_Base_Type);
2959 when Attribute_Model_Emin =>
2960 Check_Floating_Point_Type_0;
2961 Set_Etype (N, Universal_Integer);
2967 when Attribute_Model_Epsilon =>
2968 Check_Floating_Point_Type_0;
2969 Set_Etype (N, Universal_Real);
2971 --------------------
2972 -- Model_Mantissa --
2973 --------------------
2975 when Attribute_Model_Mantissa =>
2976 Check_Floating_Point_Type_0;
2977 Set_Etype (N, Universal_Integer);
2983 when Attribute_Model_Small =>
2984 Check_Floating_Point_Type_0;
2985 Set_Etype (N, Universal_Real);
2991 when Attribute_Modulus =>
2993 Check_Modular_Integer_Type;
2994 Set_Etype (N, Universal_Integer);
2996 --------------------
2997 -- Null_Parameter --
2998 --------------------
3000 when Attribute_Null_Parameter => Null_Parameter : declare
3001 Parnt : constant Node_Id := Parent (N);
3002 GParnt : constant Node_Id := Parent (Parnt);
3004 procedure Bad_Null_Parameter (Msg : String);
3005 -- Used if bad Null parameter attribute node is found. Issues
3006 -- given error message, and also sets the type to Any_Type to
3007 -- avoid blowups later on from dealing with a junk node.
3009 procedure Must_Be_Imported (Proc_Ent : Entity_Id);
3010 -- Called to check that Proc_Ent is imported subprogram
3012 ------------------------
3013 -- Bad_Null_Parameter --
3014 ------------------------
3016 procedure Bad_Null_Parameter (Msg : String) is
3018 Error_Msg_N (Msg, N);
3019 Set_Etype (N, Any_Type);
3020 end Bad_Null_Parameter;
3022 ----------------------
3023 -- Must_Be_Imported --
3024 ----------------------
3026 procedure Must_Be_Imported (Proc_Ent : Entity_Id) is
3027 Pent : Entity_Id := Proc_Ent;
3030 while Present (Alias (Pent)) loop
3031 Pent := Alias (Pent);
3034 -- Ignore check if procedure not frozen yet (we will get
3035 -- another chance when the default parameter is reanalyzed)
3037 if not Is_Frozen (Pent) then
3040 elsif not Is_Imported (Pent) then
3042 ("Null_Parameter can only be used with imported subprogram");
3047 end Must_Be_Imported;
3049 -- Start of processing for Null_Parameter
3054 Set_Etype (N, P_Type);
3056 -- Case of attribute used as default expression
3058 if Nkind (Parnt) = N_Parameter_Specification then
3059 Must_Be_Imported (Defining_Entity (GParnt));
3061 -- Case of attribute used as actual for subprogram (positional)
3063 elsif (Nkind (Parnt) = N_Procedure_Call_Statement
3065 Nkind (Parnt) = N_Function_Call)
3066 and then Is_Entity_Name (Name (Parnt))
3068 Must_Be_Imported (Entity (Name (Parnt)));
3070 -- Case of attribute used as actual for subprogram (named)
3072 elsif Nkind (Parnt) = N_Parameter_Association
3073 and then (Nkind (GParnt) = N_Procedure_Call_Statement
3075 Nkind (GParnt) = N_Function_Call)
3076 and then Is_Entity_Name (Name (GParnt))
3078 Must_Be_Imported (Entity (Name (GParnt)));
3080 -- Not an allowed case
3084 ("Null_Parameter must be actual or default parameter");
3093 when Attribute_Object_Size =>
3096 Check_Not_Incomplete_Type;
3097 Set_Etype (N, Universal_Integer);
3103 when Attribute_Output =>
3105 Check_Stream_Attribute (TSS_Stream_Output);
3106 Set_Etype (N, Standard_Void_Type);
3107 Resolve (N, Standard_Void_Type);
3113 when Attribute_Partition_ID =>
3116 if P_Type /= Any_Type then
3117 if not Is_Library_Level_Entity (Entity (P)) then
3119 ("prefix of % attribute must be library-level entity", P);
3121 -- The defining entity of prefix should not be declared inside
3122 -- a Pure unit. RM E.1(8).
3123 -- The Is_Pure flag has been set during declaration.
3125 elsif Is_Entity_Name (P)
3126 and then Is_Pure (Entity (P))
3129 ("prefix of % attribute must not be declared pure", P);
3133 Set_Etype (N, Universal_Integer);
3135 -------------------------
3136 -- Passed_By_Reference --
3137 -------------------------
3139 when Attribute_Passed_By_Reference =>
3142 Set_Etype (N, Standard_Boolean);
3148 when Attribute_Pool_Address =>
3150 Set_Etype (N, RTE (RE_Address));
3156 when Attribute_Pos =>
3157 Check_Discrete_Type;
3159 Resolve (E1, P_Base_Type);
3160 Set_Etype (N, Universal_Integer);
3166 when Attribute_Position =>
3168 Set_Etype (N, Universal_Integer);
3174 when Attribute_Pred =>
3177 Resolve (E1, P_Base_Type);
3178 Set_Etype (N, P_Base_Type);
3180 -- Nothing to do for real type case
3182 if Is_Real_Type (P_Type) then
3185 -- If not modular type, test for overflow check required
3188 if not Is_Modular_Integer_Type (P_Type)
3189 and then not Range_Checks_Suppressed (P_Base_Type)
3191 Enable_Range_Check (E1);
3199 when Attribute_Range =>
3200 Check_Array_Or_Scalar_Type;
3202 if Ada_Version = Ada_83
3203 and then Is_Scalar_Type (P_Type)
3204 and then Comes_From_Source (N)
3207 ("(Ada 83) % attribute not allowed for scalar type", P);
3214 when Attribute_Range_Length =>
3215 Check_Discrete_Type;
3216 Set_Etype (N, Universal_Integer);
3222 when Attribute_Read =>
3224 Check_Stream_Attribute (TSS_Stream_Read);
3225 Set_Etype (N, Standard_Void_Type);
3226 Resolve (N, Standard_Void_Type);
3227 Note_Possible_Modification (E2);
3233 when Attribute_Remainder =>
3234 Check_Floating_Point_Type_2;
3235 Set_Etype (N, P_Base_Type);
3236 Resolve (E1, P_Base_Type);
3237 Resolve (E2, P_Base_Type);
3243 when Attribute_Round =>
3245 Check_Decimal_Fixed_Point_Type;
3246 Set_Etype (N, P_Base_Type);
3248 -- Because the context is universal_real (3.5.10(12)) it is a legal
3249 -- context for a universal fixed expression. This is the only
3250 -- attribute whose functional description involves U_R.
3252 if Etype (E1) = Universal_Fixed then
3254 Conv : constant Node_Id := Make_Type_Conversion (Loc,
3255 Subtype_Mark => New_Occurrence_Of (Universal_Real, Loc),
3256 Expression => Relocate_Node (E1));
3264 Resolve (E1, Any_Real);
3270 when Attribute_Rounding =>
3271 Check_Floating_Point_Type_1;
3272 Set_Etype (N, P_Base_Type);
3273 Resolve (E1, P_Base_Type);
3279 when Attribute_Safe_Emax =>
3280 Check_Floating_Point_Type_0;
3281 Set_Etype (N, Universal_Integer);
3287 when Attribute_Safe_First =>
3288 Check_Floating_Point_Type_0;
3289 Set_Etype (N, Universal_Real);
3295 when Attribute_Safe_Large =>
3298 Set_Etype (N, Universal_Real);
3304 when Attribute_Safe_Last =>
3305 Check_Floating_Point_Type_0;
3306 Set_Etype (N, Universal_Real);
3312 when Attribute_Safe_Small =>
3315 Set_Etype (N, Universal_Real);
3321 when Attribute_Scale =>
3323 Check_Decimal_Fixed_Point_Type;
3324 Set_Etype (N, Universal_Integer);
3330 when Attribute_Scaling =>
3331 Check_Floating_Point_Type_2;
3332 Set_Etype (N, P_Base_Type);
3333 Resolve (E1, P_Base_Type);
3339 when Attribute_Signed_Zeros =>
3340 Check_Floating_Point_Type_0;
3341 Set_Etype (N, Standard_Boolean);
3347 when Attribute_Size | Attribute_VADS_Size =>
3350 -- If prefix is parameterless function call, rewrite and resolve
3353 if Is_Entity_Name (P)
3354 and then Ekind (Entity (P)) = E_Function
3358 -- Similar processing for a protected function call
3360 elsif Nkind (P) = N_Selected_Component
3361 and then Ekind (Entity (Selector_Name (P))) = E_Function
3366 if Is_Object_Reference (P) then
3367 Check_Object_Reference (P);
3369 elsif Is_Entity_Name (P)
3370 and then Is_Type (Entity (P))
3374 elsif Nkind (P) = N_Type_Conversion
3375 and then not Comes_From_Source (P)
3380 Error_Attr ("invalid prefix for % attribute", P);
3383 Check_Not_Incomplete_Type;
3384 Set_Etype (N, Universal_Integer);
3390 when Attribute_Small =>
3393 Set_Etype (N, Universal_Real);
3399 when Attribute_Storage_Pool =>
3400 if Is_Access_Type (P_Type) then
3403 -- Set appropriate entity
3405 if Present (Associated_Storage_Pool (Root_Type (P_Type))) then
3406 Set_Entity (N, Associated_Storage_Pool (Root_Type (P_Type)));
3408 Set_Entity (N, RTE (RE_Global_Pool_Object));
3411 Set_Etype (N, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
3413 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
3414 -- Storage_Pool since this attribute is not defined for such
3415 -- types (RM E.2.3(22)).
3417 Validate_Remote_Access_To_Class_Wide_Type (N);
3420 Error_Attr ("prefix of % attribute must be access type", P);
3427 when Attribute_Storage_Size =>
3429 if Is_Task_Type (P_Type) then
3431 Set_Etype (N, Universal_Integer);
3433 elsif Is_Access_Type (P_Type) then
3434 if Is_Entity_Name (P)
3435 and then Is_Type (Entity (P))
3439 Set_Etype (N, Universal_Integer);
3441 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
3442 -- Storage_Size since this attribute is not defined for
3443 -- such types (RM E.2.3(22)).
3445 Validate_Remote_Access_To_Class_Wide_Type (N);
3447 -- The prefix is allowed to be an implicit dereference
3448 -- of an access value designating a task.
3453 Set_Etype (N, Universal_Integer);
3458 ("prefix of % attribute must be access or task type", P);
3465 when Attribute_Storage_Unit =>
3466 Standard_Attribute (Ttypes.System_Storage_Unit);
3472 when Attribute_Stream_Size =>
3476 if Is_Entity_Name (P)
3477 and then Is_Elementary_Type (Entity (P))
3479 Set_Etype (N, Universal_Integer);
3481 Error_Attr ("invalid prefix for % attribute", P);
3488 when Attribute_Succ =>
3491 Resolve (E1, P_Base_Type);
3492 Set_Etype (N, P_Base_Type);
3494 -- Nothing to do for real type case
3496 if Is_Real_Type (P_Type) then
3499 -- If not modular type, test for overflow check required.
3502 if not Is_Modular_Integer_Type (P_Type)
3503 and then not Range_Checks_Suppressed (P_Base_Type)
3505 Enable_Range_Check (E1);
3513 when Attribute_Tag =>
3517 if not Is_Tagged_Type (P_Type) then
3518 Error_Attr ("prefix of % attribute must be tagged", P);
3520 -- Next test does not apply to generated code
3521 -- why not, and what does the illegal reference mean???
3523 elsif Is_Object_Reference (P)
3524 and then not Is_Class_Wide_Type (P_Type)
3525 and then Comes_From_Source (N)
3528 ("% attribute can only be applied to objects of class-wide type",
3532 Set_Etype (N, RTE (RE_Tag));
3538 when Attribute_Target_Name => Target_Name : declare
3539 TN : constant String := Sdefault.Target_Name.all;
3543 Check_Standard_Prefix;
3548 if TN (TL) = '/' or else TN (TL) = '\' then
3553 Make_String_Literal (Loc,
3554 Strval => TN (TN'First .. TL)));
3555 Analyze_And_Resolve (N, Standard_String);
3562 when Attribute_Terminated =>
3564 Set_Etype (N, Standard_Boolean);
3571 when Attribute_To_Address =>
3575 if Nkind (P) /= N_Identifier
3576 or else Chars (P) /= Name_System
3578 Error_Attr ("prefix of %attribute must be System", P);
3581 Generate_Reference (RTE (RE_Address), P);
3582 Analyze_And_Resolve (E1, Any_Integer);
3583 Set_Etype (N, RTE (RE_Address));
3589 when Attribute_Truncation =>
3590 Check_Floating_Point_Type_1;
3591 Resolve (E1, P_Base_Type);
3592 Set_Etype (N, P_Base_Type);
3598 when Attribute_Type_Class =>
3601 Check_Not_Incomplete_Type;
3602 Set_Etype (N, RTE (RE_Type_Class));
3608 when Attribute_UET_Address =>
3610 Check_Unit_Name (P);
3611 Set_Etype (N, RTE (RE_Address));
3613 -----------------------
3614 -- Unbiased_Rounding --
3615 -----------------------
3617 when Attribute_Unbiased_Rounding =>
3618 Check_Floating_Point_Type_1;
3619 Set_Etype (N, P_Base_Type);
3620 Resolve (E1, P_Base_Type);
3622 ----------------------
3623 -- Unchecked_Access --
3624 ----------------------
3626 when Attribute_Unchecked_Access =>
3627 if Comes_From_Source (N) then
3628 Check_Restriction (No_Unchecked_Access, N);
3631 Analyze_Access_Attribute;
3633 -------------------------
3634 -- Unconstrained_Array --
3635 -------------------------
3637 when Attribute_Unconstrained_Array =>
3640 Check_Not_Incomplete_Type;
3641 Set_Etype (N, Standard_Boolean);
3643 ------------------------------
3644 -- Universal_Literal_String --
3645 ------------------------------
3647 -- This is a GNAT specific attribute whose prefix must be a named
3648 -- number where the expression is either a single numeric literal,
3649 -- or a numeric literal immediately preceded by a minus sign. The
3650 -- result is equivalent to a string literal containing the text of
3651 -- the literal as it appeared in the source program with a possible
3652 -- leading minus sign.
3654 when Attribute_Universal_Literal_String => Universal_Literal_String :
3658 if not Is_Entity_Name (P)
3659 or else Ekind (Entity (P)) not in Named_Kind
3661 Error_Attr ("prefix for % attribute must be named number", P);
3668 Src : Source_Buffer_Ptr;
3671 Expr := Original_Node (Expression (Parent (Entity (P))));
3673 if Nkind (Expr) = N_Op_Minus then
3675 Expr := Original_Node (Right_Opnd (Expr));
3680 if Nkind (Expr) /= N_Integer_Literal
3681 and then Nkind (Expr) /= N_Real_Literal
3684 ("named number for % attribute must be simple literal", N);
3687 -- Build string literal corresponding to source literal text
3692 Store_String_Char (Get_Char_Code ('-'));
3696 Src := Source_Text (Get_Source_File_Index (S));
3698 while Src (S) /= ';' and then Src (S) /= ' ' loop
3699 Store_String_Char (Get_Char_Code (Src (S)));
3703 -- Now we rewrite the attribute with the string literal
3706 Make_String_Literal (Loc, End_String));
3710 end Universal_Literal_String;
3712 -------------------------
3713 -- Unrestricted_Access --
3714 -------------------------
3716 -- This is a GNAT specific attribute which is like Access except that
3717 -- all scope checks and checks for aliased views are omitted.
3719 when Attribute_Unrestricted_Access =>
3720 if Comes_From_Source (N) then
3721 Check_Restriction (No_Unchecked_Access, N);
3724 if Is_Entity_Name (P) then
3725 Set_Address_Taken (Entity (P));
3728 Analyze_Access_Attribute;
3734 when Attribute_Val => Val : declare
3737 Check_Discrete_Type;
3738 Resolve (E1, Any_Integer);
3739 Set_Etype (N, P_Base_Type);
3741 -- Note, we need a range check in general, but we wait for the
3742 -- Resolve call to do this, since we want to let Eval_Attribute
3743 -- have a chance to find an static illegality first!
3750 when Attribute_Valid =>
3753 -- Ignore check for object if we have a 'Valid reference generated
3754 -- by the expanded code, since in some cases valid checks can occur
3755 -- on items that are names, but are not objects (e.g. attributes).
3757 if Comes_From_Source (N) then
3758 Check_Object_Reference (P);
3761 if not Is_Scalar_Type (P_Type) then
3762 Error_Attr ("object for % attribute must be of scalar type", P);
3765 Set_Etype (N, Standard_Boolean);
3771 when Attribute_Value => Value :
3776 if Is_Enumeration_Type (P_Type) then
3777 Check_Restriction (No_Enumeration_Maps, N);
3780 -- Set Etype before resolving expression because expansion of
3781 -- expression may require enclosing type. Note that the type
3782 -- returned by 'Value is the base type of the prefix type.
3784 Set_Etype (N, P_Base_Type);
3785 Validate_Non_Static_Attribute_Function_Call;
3792 when Attribute_Value_Size =>
3795 Check_Not_Incomplete_Type;
3796 Set_Etype (N, Universal_Integer);
3802 when Attribute_Version =>
3805 Set_Etype (N, RTE (RE_Version_String));
3811 when Attribute_Wchar_T_Size =>
3812 Standard_Attribute (Interfaces_Wchar_T_Size);
3818 when Attribute_Wide_Image => Wide_Image :
3821 Set_Etype (N, Standard_Wide_String);
3823 Resolve (E1, P_Base_Type);
3824 Validate_Non_Static_Attribute_Function_Call;
3827 ---------------------
3828 -- Wide_Wide_Image --
3829 ---------------------
3831 when Attribute_Wide_Wide_Image => Wide_Wide_Image :
3834 Set_Etype (N, Standard_Wide_Wide_String);
3836 Resolve (E1, P_Base_Type);
3837 Validate_Non_Static_Attribute_Function_Call;
3838 end Wide_Wide_Image;
3844 when Attribute_Wide_Value => Wide_Value :
3849 -- Set Etype before resolving expression because expansion
3850 -- of expression may require enclosing type.
3852 Set_Etype (N, P_Type);
3853 Validate_Non_Static_Attribute_Function_Call;
3856 ---------------------
3857 -- Wide_Wide_Value --
3858 ---------------------
3860 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
3865 -- Set Etype before resolving expression because expansion
3866 -- of expression may require enclosing type.
3868 Set_Etype (N, P_Type);
3869 Validate_Non_Static_Attribute_Function_Call;
3870 end Wide_Wide_Value;
3872 ---------------------
3873 -- Wide_Wide_Width --
3874 ---------------------
3876 when Attribute_Wide_Wide_Width =>
3879 Set_Etype (N, Universal_Integer);
3885 when Attribute_Wide_Width =>
3888 Set_Etype (N, Universal_Integer);
3894 when Attribute_Width =>
3897 Set_Etype (N, Universal_Integer);
3903 when Attribute_Word_Size =>
3904 Standard_Attribute (System_Word_Size);
3910 when Attribute_Write =>
3912 Check_Stream_Attribute (TSS_Stream_Write);
3913 Set_Etype (N, Standard_Void_Type);
3914 Resolve (N, Standard_Void_Type);
3918 -- All errors raise Bad_Attribute, so that we get out before any further
3919 -- damage occurs when an error is detected (for example, if we check for
3920 -- one attribute expression, and the check succeeds, we want to be able
3921 -- to proceed securely assuming that an expression is in fact present.
3923 -- Note: we set the attribute analyzed in this case to prevent any
3924 -- attempt at reanalysis which could generate spurious error msgs.
3927 when Bad_Attribute =>
3929 Set_Etype (N, Any_Type);
3931 end Analyze_Attribute;
3933 --------------------
3934 -- Eval_Attribute --
3935 --------------------
3937 procedure Eval_Attribute (N : Node_Id) is
3938 Loc : constant Source_Ptr := Sloc (N);
3939 Aname : constant Name_Id := Attribute_Name (N);
3940 Id : constant Attribute_Id := Get_Attribute_Id (Aname);
3941 P : constant Node_Id := Prefix (N);
3943 C_Type : constant Entity_Id := Etype (N);
3944 -- The type imposed by the context.
3947 -- First expression, or Empty if none
3950 -- Second expression, or Empty if none
3952 P_Entity : Entity_Id;
3953 -- Entity denoted by prefix
3956 -- The type of the prefix
3958 P_Base_Type : Entity_Id;
3959 -- The base type of the prefix type
3961 P_Root_Type : Entity_Id;
3962 -- The root type of the prefix type
3965 -- True if the result is Static. This is set by the general processing
3966 -- to true if the prefix is static, and all expressions are static. It
3967 -- can be reset as processing continues for particular attributes
3969 Lo_Bound, Hi_Bound : Node_Id;
3970 -- Expressions for low and high bounds of type or array index referenced
3971 -- by First, Last, or Length attribute for array, set by Set_Bounds.
3974 -- Constraint error node used if we have an attribute reference has
3975 -- an argument that raises a constraint error. In this case we replace
3976 -- the attribute with a raise constraint_error node. This is important
3977 -- processing, since otherwise gigi might see an attribute which it is
3978 -- unprepared to deal with.
3980 function Aft_Value return Nat;
3981 -- Computes Aft value for current attribute prefix (used by Aft itself
3982 -- and also by Width for computing the Width of a fixed point type).
3984 procedure Check_Expressions;
3985 -- In case where the attribute is not foldable, the expressions, if
3986 -- any, of the attribute, are in a non-static context. This procedure
3987 -- performs the required additional checks.
3989 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean;
3990 -- Determines if the given type has compile time known bounds. Note
3991 -- that we enter the case statement even in cases where the prefix
3992 -- type does NOT have known bounds, so it is important to guard any
3993 -- attempt to evaluate both bounds with a call to this function.
3995 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint);
3996 -- This procedure is called when the attribute N has a non-static
3997 -- but compile time known value given by Val. It includes the
3998 -- necessary checks for out of range values.
4000 procedure Float_Attribute_Universal_Integer
4009 -- This procedure evaluates a float attribute with no arguments that
4010 -- returns a universal integer result. The parameters give the values
4011 -- for the possible floating-point root types. See ttypef for details.
4012 -- The prefix type is a float type (and is thus not a generic type).
4014 procedure Float_Attribute_Universal_Real
4015 (IEEES_Val : String;
4022 AAMPL_Val : String);
4023 -- This procedure evaluates a float attribute with no arguments that
4024 -- returns a universal real result. The parameters give the values
4025 -- required for the possible floating-point root types in string
4026 -- format as real literals with a possible leading minus sign.
4027 -- The prefix type is a float type (and is thus not a generic type).
4029 function Fore_Value return Nat;
4030 -- Computes the Fore value for the current attribute prefix, which is
4031 -- known to be a static fixed-point type. Used by Fore and Width.
4033 function Mantissa return Uint;
4034 -- Returns the Mantissa value for the prefix type
4036 procedure Set_Bounds;
4037 -- Used for First, Last and Length attributes applied to an array or
4038 -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low
4039 -- and high bound expressions for the index referenced by the attribute
4040 -- designator (i.e. the first index if no expression is present, and
4041 -- the N'th index if the value N is present as an expression). Also
4042 -- used for First and Last of scalar types. Static is reset to False
4043 -- if the type or index type is not statically constrained.
4049 function Aft_Value return Nat is
4055 Delta_Val := Delta_Value (P_Type);
4057 while Delta_Val < Ureal_Tenth loop
4058 Delta_Val := Delta_Val * Ureal_10;
4059 Result := Result + 1;
4065 -----------------------
4066 -- Check_Expressions --
4067 -----------------------
4069 procedure Check_Expressions is
4073 while Present (E) loop
4074 Check_Non_Static_Context (E);
4077 end Check_Expressions;
4079 ----------------------------------
4080 -- Compile_Time_Known_Attribute --
4081 ----------------------------------
4083 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint) is
4084 T : constant Entity_Id := Etype (N);
4087 Fold_Uint (N, Val, False);
4089 -- Check that result is in bounds of the type if it is static
4091 if Is_In_Range (N, T) then
4094 elsif Is_Out_Of_Range (N, T) then
4095 Apply_Compile_Time_Constraint_Error
4096 (N, "value not in range of}?", CE_Range_Check_Failed);
4098 elsif not Range_Checks_Suppressed (T) then
4099 Enable_Range_Check (N);
4102 Set_Do_Range_Check (N, False);
4104 end Compile_Time_Known_Attribute;
4106 -------------------------------
4107 -- Compile_Time_Known_Bounds --
4108 -------------------------------
4110 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean is
4113 Compile_Time_Known_Value (Type_Low_Bound (Typ))
4115 Compile_Time_Known_Value (Type_High_Bound (Typ));
4116 end Compile_Time_Known_Bounds;
4118 ---------------------------------------
4119 -- Float_Attribute_Universal_Integer --
4120 ---------------------------------------
4122 procedure Float_Attribute_Universal_Integer
4133 Digs : constant Nat := UI_To_Int (Digits_Value (P_Base_Type));
4136 if Vax_Float (P_Base_Type) then
4137 if Digs = VAXFF_Digits then
4139 elsif Digs = VAXDF_Digits then
4141 else pragma Assert (Digs = VAXGF_Digits);
4145 elsif Is_AAMP_Float (P_Base_Type) then
4146 if Digs = AAMPS_Digits then
4148 else pragma Assert (Digs = AAMPL_Digits);
4153 if Digs = IEEES_Digits then
4155 elsif Digs = IEEEL_Digits then
4157 else pragma Assert (Digs = IEEEX_Digits);
4162 Fold_Uint (N, UI_From_Int (Val), True);
4163 end Float_Attribute_Universal_Integer;
4165 ------------------------------------
4166 -- Float_Attribute_Universal_Real --
4167 ------------------------------------
4169 procedure Float_Attribute_Universal_Real
4170 (IEEES_Val : String;
4180 Digs : constant Nat := UI_To_Int (Digits_Value (P_Base_Type));
4183 if Vax_Float (P_Base_Type) then
4184 if Digs = VAXFF_Digits then
4185 Val := Real_Convert (VAXFF_Val);
4186 elsif Digs = VAXDF_Digits then
4187 Val := Real_Convert (VAXDF_Val);
4188 else pragma Assert (Digs = VAXGF_Digits);
4189 Val := Real_Convert (VAXGF_Val);
4192 elsif Is_AAMP_Float (P_Base_Type) then
4193 if Digs = AAMPS_Digits then
4194 Val := Real_Convert (AAMPS_Val);
4195 else pragma Assert (Digs = AAMPL_Digits);
4196 Val := Real_Convert (AAMPL_Val);
4200 if Digs = IEEES_Digits then
4201 Val := Real_Convert (IEEES_Val);
4202 elsif Digs = IEEEL_Digits then
4203 Val := Real_Convert (IEEEL_Val);
4204 else pragma Assert (Digs = IEEEX_Digits);
4205 Val := Real_Convert (IEEEX_Val);
4209 Set_Sloc (Val, Loc);
4211 Set_Is_Static_Expression (N, Static);
4212 Analyze_And_Resolve (N, C_Type);
4213 end Float_Attribute_Universal_Real;
4219 -- Note that the Fore calculation is based on the actual values
4220 -- of the bounds, and does not take into account possible rounding.
4222 function Fore_Value return Nat is
4223 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
4224 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
4225 Small : constant Ureal := Small_Value (P_Type);
4226 Lo_Real : constant Ureal := Lo * Small;
4227 Hi_Real : constant Ureal := Hi * Small;
4232 -- Bounds are given in terms of small units, so first compute
4233 -- proper values as reals.
4235 T := UR_Max (abs Lo_Real, abs Hi_Real);
4238 -- Loop to compute proper value if more than one digit required
4240 while T >= Ureal_10 loop
4252 -- Table of mantissa values accessed by function Computed using
4255 -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1)
4257 -- where D is T'Digits (RM83 3.5.7)
4259 Mantissa_Value : constant array (Nat range 1 .. 40) of Nat := (
4301 function Mantissa return Uint is
4304 UI_From_Int (Mantissa_Value (UI_To_Int (Digits_Value (P_Type))));
4311 procedure Set_Bounds is
4317 -- For a string literal subtype, we have to construct the bounds.
4318 -- Valid Ada code never applies attributes to string literals, but
4319 -- it is convenient to allow the expander to generate attribute
4320 -- references of this type (e.g. First and Last applied to a string
4323 -- Note that the whole point of the E_String_Literal_Subtype is to
4324 -- avoid this construction of bounds, but the cases in which we
4325 -- have to materialize them are rare enough that we don't worry!
4327 -- The low bound is simply the low bound of the base type. The
4328 -- high bound is computed from the length of the string and this
4331 if Ekind (P_Type) = E_String_Literal_Subtype then
4332 Ityp := Etype (First_Index (Base_Type (P_Type)));
4333 Lo_Bound := Type_Low_Bound (Ityp);
4336 Make_Integer_Literal (Sloc (P),
4338 Expr_Value (Lo_Bound) + String_Literal_Length (P_Type) - 1);
4340 Set_Parent (Hi_Bound, P);
4341 Analyze_And_Resolve (Hi_Bound, Etype (Lo_Bound));
4344 -- For non-array case, just get bounds of scalar type
4346 elsif Is_Scalar_Type (P_Type) then
4349 -- For a fixed-point type, we must freeze to get the attributes
4350 -- of the fixed-point type set now so we can reference them.
4352 if Is_Fixed_Point_Type (P_Type)
4353 and then not Is_Frozen (Base_Type (P_Type))
4354 and then Compile_Time_Known_Value (Type_Low_Bound (P_Type))
4355 and then Compile_Time_Known_Value (Type_High_Bound (P_Type))
4357 Freeze_Fixed_Point_Type (Base_Type (P_Type));
4360 -- For array case, get type of proper index
4366 Ndim := UI_To_Int (Expr_Value (E1));
4369 Indx := First_Index (P_Type);
4370 for J in 1 .. Ndim - 1 loop
4374 -- If no index type, get out (some other error occurred, and
4375 -- we don't have enough information to complete the job!)
4383 Ityp := Etype (Indx);
4386 -- A discrete range in an index constraint is allowed to be a
4387 -- subtype indication. This is syntactically a pain, but should
4388 -- not propagate to the entity for the corresponding index subtype.
4389 -- After checking that the subtype indication is legal, the range
4390 -- of the subtype indication should be transfered to the entity.
4391 -- The attributes for the bounds should remain the simple retrievals
4392 -- that they are now.
4394 Lo_Bound := Type_Low_Bound (Ityp);
4395 Hi_Bound := Type_High_Bound (Ityp);
4397 if not Is_Static_Subtype (Ityp) then
4402 -- Start of processing for Eval_Attribute
4405 -- Acquire first two expressions (at the moment, no attributes
4406 -- take more than two expressions in any case).
4408 if Present (Expressions (N)) then
4409 E1 := First (Expressions (N));
4416 -- Special processing for cases where the prefix is an object. For
4417 -- this purpose, a string literal counts as an object (attributes
4418 -- of string literals can only appear in generated code).
4420 if Is_Object_Reference (P) or else Nkind (P) = N_String_Literal then
4422 -- For Component_Size, the prefix is an array object, and we apply
4423 -- the attribute to the type of the object. This is allowed for
4424 -- both unconstrained and constrained arrays, since the bounds
4425 -- have no influence on the value of this attribute.
4427 if Id = Attribute_Component_Size then
4428 P_Entity := Etype (P);
4430 -- For First and Last, the prefix is an array object, and we apply
4431 -- the attribute to the type of the array, but we need a constrained
4432 -- type for this, so we use the actual subtype if available.
4434 elsif Id = Attribute_First
4438 Id = Attribute_Length
4441 AS : constant Entity_Id := Get_Actual_Subtype_If_Available (P);
4444 if Present (AS) and then Is_Constrained (AS) then
4447 -- If we have an unconstrained type, cannot fold
4455 -- For Size, give size of object if available, otherwise we
4456 -- cannot fold Size.
4458 elsif Id = Attribute_Size then
4459 if Is_Entity_Name (P)
4460 and then Known_Esize (Entity (P))
4462 Compile_Time_Known_Attribute (N, Esize (Entity (P)));
4470 -- For Alignment, give size of object if available, otherwise we
4471 -- cannot fold Alignment.
4473 elsif Id = Attribute_Alignment then
4474 if Is_Entity_Name (P)
4475 and then Known_Alignment (Entity (P))
4477 Fold_Uint (N, Alignment (Entity (P)), False);
4485 -- No other attributes for objects are folded
4492 -- Cases where P is not an object. Cannot do anything if P is
4493 -- not the name of an entity.
4495 elsif not Is_Entity_Name (P) then
4499 -- Otherwise get prefix entity
4502 P_Entity := Entity (P);
4505 -- At this stage P_Entity is the entity to which the attribute
4506 -- is to be applied. This is usually simply the entity of the
4507 -- prefix, except in some cases of attributes for objects, where
4508 -- as described above, we apply the attribute to the object type.
4510 -- First foldable possibility is a scalar or array type (RM 4.9(7))
4511 -- that is not generic (generic types are eliminated by RM 4.9(25)).
4512 -- Note we allow non-static non-generic types at this stage as further
4515 if Is_Type (P_Entity)
4516 and then (Is_Scalar_Type (P_Entity) or Is_Array_Type (P_Entity))
4517 and then (not Is_Generic_Type (P_Entity))
4521 -- Second foldable possibility is an array object (RM 4.9(8))
4523 elsif (Ekind (P_Entity) = E_Variable
4525 Ekind (P_Entity) = E_Constant)
4526 and then Is_Array_Type (Etype (P_Entity))
4527 and then (not Is_Generic_Type (Etype (P_Entity)))
4529 P_Type := Etype (P_Entity);
4531 -- If the entity is an array constant with an unconstrained
4532 -- nominal subtype then get the type from the initial value.
4533 -- If the value has been expanded into assignments, the expression
4534 -- is not present and the attribute reference remains dynamic.
4535 -- We could do better here and retrieve the type ???
4537 if Ekind (P_Entity) = E_Constant
4538 and then not Is_Constrained (P_Type)
4540 if No (Constant_Value (P_Entity)) then
4543 P_Type := Etype (Constant_Value (P_Entity));
4547 -- Definite must be folded if the prefix is not a generic type,
4548 -- that is to say if we are within an instantiation. Same processing
4549 -- applies to the GNAT attributes Has_Discriminants, Type_Class,
4550 -- and Unconstrained_Array.
4552 elsif (Id = Attribute_Definite
4554 Id = Attribute_Has_Access_Values
4556 Id = Attribute_Has_Discriminants
4558 Id = Attribute_Type_Class
4560 Id = Attribute_Unconstrained_Array)
4561 and then not Is_Generic_Type (P_Entity)
4565 -- We can fold 'Size applied to a type if the size is known
4566 -- (as happens for a size from an attribute definition clause).
4567 -- At this stage, this can happen only for types (e.g. record
4568 -- types) for which the size is always non-static. We exclude
4569 -- generic types from consideration (since they have bogus
4570 -- sizes set within templates).
4572 elsif Id = Attribute_Size
4573 and then Is_Type (P_Entity)
4574 and then (not Is_Generic_Type (P_Entity))
4575 and then Known_Static_RM_Size (P_Entity)
4577 Compile_Time_Known_Attribute (N, RM_Size (P_Entity));
4580 -- We can fold 'Alignment applied to a type if the alignment is known
4581 -- (as happens for an alignment from an attribute definition clause).
4582 -- At this stage, this can happen only for types (e.g. record
4583 -- types) for which the size is always non-static. We exclude
4584 -- generic types from consideration (since they have bogus
4585 -- sizes set within templates).
4587 elsif Id = Attribute_Alignment
4588 and then Is_Type (P_Entity)
4589 and then (not Is_Generic_Type (P_Entity))
4590 and then Known_Alignment (P_Entity)
4592 Compile_Time_Known_Attribute (N, Alignment (P_Entity));
4595 -- If this is an access attribute that is known to fail accessibility
4596 -- check, rewrite accordingly.
4598 elsif Attribute_Name (N) = Name_Access
4599 and then Raises_Constraint_Error (N)
4602 Make_Raise_Program_Error (Loc,
4603 Reason => PE_Accessibility_Check_Failed));
4604 Set_Etype (N, C_Type);
4607 -- No other cases are foldable (they certainly aren't static, and at
4608 -- the moment we don't try to fold any cases other than these three).
4615 -- If either attribute or the prefix is Any_Type, then propagate
4616 -- Any_Type to the result and don't do anything else at all.
4618 if P_Type = Any_Type
4619 or else (Present (E1) and then Etype (E1) = Any_Type)
4620 or else (Present (E2) and then Etype (E2) = Any_Type)
4622 Set_Etype (N, Any_Type);
4626 -- Scalar subtype case. We have not yet enforced the static requirement
4627 -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases
4628 -- of non-static attribute references (e.g. S'Digits for a non-static
4629 -- floating-point type, which we can compute at compile time).
4631 -- Note: this folding of non-static attributes is not simply a case of
4632 -- optimization. For many of the attributes affected, Gigi cannot handle
4633 -- the attribute and depends on the front end having folded them away.
4635 -- Note: although we don't require staticness at this stage, we do set
4636 -- the Static variable to record the staticness, for easy reference by
4637 -- those attributes where it matters (e.g. Succ and Pred), and also to
4638 -- be used to ensure that non-static folded things are not marked as
4639 -- being static (a check that is done right at the end).
4641 P_Root_Type := Root_Type (P_Type);
4642 P_Base_Type := Base_Type (P_Type);
4644 -- If the root type or base type is generic, then we cannot fold. This
4645 -- test is needed because subtypes of generic types are not always
4646 -- marked as being generic themselves (which seems odd???)
4648 if Is_Generic_Type (P_Root_Type)
4649 or else Is_Generic_Type (P_Base_Type)
4654 if Is_Scalar_Type (P_Type) then
4655 Static := Is_OK_Static_Subtype (P_Type);
4657 -- Array case. We enforce the constrained requirement of (RM 4.9(7-8))
4658 -- since we can't do anything with unconstrained arrays. In addition,
4659 -- only the First, Last and Length attributes are possibly static.
4660 -- In addition Component_Size is possibly foldable, even though it
4661 -- can never be static.
4663 -- Definite, Has_Access_Values, Has_Discriminants, Type_Class, and
4664 -- Unconstrained_Array are again exceptions, because they apply as
4665 -- well to unconstrained types.
4667 elsif Id = Attribute_Definite
4669 Id = Attribute_Has_Access_Values
4671 Id = Attribute_Has_Discriminants
4673 Id = Attribute_Type_Class
4675 Id = Attribute_Unconstrained_Array
4680 if not Is_Constrained (P_Type)
4681 or else (Id /= Attribute_Component_Size and then
4682 Id /= Attribute_First and then
4683 Id /= Attribute_Last and then
4684 Id /= Attribute_Length)
4690 -- The rules in (RM 4.9(7,8)) require a static array, but as in the
4691 -- scalar case, we hold off on enforcing staticness, since there are
4692 -- cases which we can fold at compile time even though they are not
4693 -- static (e.g. 'Length applied to a static index, even though other
4694 -- non-static indexes make the array type non-static). This is only
4695 -- an optimization, but it falls out essentially free, so why not.
4696 -- Again we compute the variable Static for easy reference later
4697 -- (note that no array attributes are static in Ada 83).
4699 Static := Ada_Version >= Ada_95;
4705 N := First_Index (P_Type);
4706 while Present (N) loop
4707 Static := Static and then Is_Static_Subtype (Etype (N));
4709 -- If however the index type is generic, attributes cannot
4712 if Is_Generic_Type (Etype (N))
4713 and then Id /= Attribute_Component_Size
4723 -- Check any expressions that are present. Note that these expressions,
4724 -- depending on the particular attribute type, are either part of the
4725 -- attribute designator, or they are arguments in a case where the
4726 -- attribute reference returns a function. In the latter case, the
4727 -- rule in (RM 4.9(22)) applies and in particular requires the type
4728 -- of the expressions to be scalar in order for the attribute to be
4729 -- considered to be static.
4736 while Present (E) loop
4738 -- If expression is not static, then the attribute reference
4739 -- result certainly cannot be static.
4741 if not Is_Static_Expression (E) then
4745 -- If the result is not known at compile time, or is not of
4746 -- a scalar type, then the result is definitely not static,
4747 -- so we can quit now.
4749 if not Compile_Time_Known_Value (E)
4750 or else not Is_Scalar_Type (Etype (E))
4752 -- An odd special case, if this is a Pos attribute, this
4753 -- is where we need to apply a range check since it does
4754 -- not get done anywhere else.
4756 if Id = Attribute_Pos then
4757 if Is_Integer_Type (Etype (E)) then
4758 Apply_Range_Check (E, Etype (N));
4765 -- If the expression raises a constraint error, then so does
4766 -- the attribute reference. We keep going in this case because
4767 -- we are still interested in whether the attribute reference
4768 -- is static even if it is not static.
4770 elsif Raises_Constraint_Error (E) then
4771 Set_Raises_Constraint_Error (N);
4777 if Raises_Constraint_Error (Prefix (N)) then
4782 -- Deal with the case of a static attribute reference that raises
4783 -- constraint error. The Raises_Constraint_Error flag will already
4784 -- have been set, and the Static flag shows whether the attribute
4785 -- reference is static. In any case we certainly can't fold such an
4786 -- attribute reference.
4788 -- Note that the rewriting of the attribute node with the constraint
4789 -- error node is essential in this case, because otherwise Gigi might
4790 -- blow up on one of the attributes it never expects to see.
4792 -- The constraint_error node must have the type imposed by the context,
4793 -- to avoid spurious errors in the enclosing expression.
4795 if Raises_Constraint_Error (N) then
4797 Make_Raise_Constraint_Error (Sloc (N),
4798 Reason => CE_Range_Check_Failed);
4799 Set_Etype (CE_Node, Etype (N));
4800 Set_Raises_Constraint_Error (CE_Node);
4802 Rewrite (N, Relocate_Node (CE_Node));
4803 Set_Is_Static_Expression (N, Static);
4807 -- At this point we have a potentially foldable attribute reference.
4808 -- If Static is set, then the attribute reference definitely obeys
4809 -- the requirements in (RM 4.9(7,8,22)), and it definitely can be
4810 -- folded. If Static is not set, then the attribute may or may not
4811 -- be foldable, and the individual attribute processing routines
4812 -- test Static as required in cases where it makes a difference.
4814 -- In the case where Static is not set, we do know that all the
4815 -- expressions present are at least known at compile time (we
4816 -- assumed above that if this was not the case, then there was
4817 -- no hope of static evaluation). However, we did not require
4818 -- that the bounds of the prefix type be compile time known,
4819 -- let alone static). That's because there are many attributes
4820 -- that can be computed at compile time on non-static subtypes,
4821 -- even though such references are not static expressions.
4829 when Attribute_Adjacent =>
4832 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
4838 when Attribute_Aft =>
4839 Fold_Uint (N, UI_From_Int (Aft_Value), True);
4845 when Attribute_Alignment => Alignment_Block : declare
4846 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
4849 -- Fold if alignment is set and not otherwise
4851 if Known_Alignment (P_TypeA) then
4852 Fold_Uint (N, Alignment (P_TypeA), Is_Discrete_Type (P_TypeA));
4854 end Alignment_Block;
4860 -- Can only be folded in No_Ast_Handler case
4862 when Attribute_AST_Entry =>
4863 if not Is_AST_Entry (P_Entity) then
4865 New_Occurrence_Of (RTE (RE_No_AST_Handler), Loc));
4874 -- Bit can never be folded
4876 when Attribute_Bit =>
4883 -- Body_version can never be static
4885 when Attribute_Body_Version =>
4892 when Attribute_Ceiling =>
4894 Eval_Fat.Ceiling (P_Root_Type, Expr_Value_R (E1)), Static);
4896 --------------------
4897 -- Component_Size --
4898 --------------------
4900 when Attribute_Component_Size =>
4901 if Known_Static_Component_Size (P_Type) then
4902 Fold_Uint (N, Component_Size (P_Type), False);
4909 when Attribute_Compose =>
4912 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)),
4919 -- Constrained is never folded for now, there may be cases that
4920 -- could be handled at compile time. to be looked at later.
4922 when Attribute_Constrained =>
4929 when Attribute_Copy_Sign =>
4932 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
4938 when Attribute_Delta =>
4939 Fold_Ureal (N, Delta_Value (P_Type), True);
4945 when Attribute_Definite =>
4946 Rewrite (N, New_Occurrence_Of (
4947 Boolean_Literals (not Is_Indefinite_Subtype (P_Entity)), Loc));
4948 Analyze_And_Resolve (N, Standard_Boolean);
4954 when Attribute_Denorm =>
4956 (N, UI_From_Int (Boolean'Pos (Denorm_On_Target)), True);
4962 when Attribute_Digits =>
4963 Fold_Uint (N, Digits_Value (P_Type), True);
4969 when Attribute_Emax =>
4971 -- Ada 83 attribute is defined as (RM83 3.5.8)
4973 -- T'Emax = 4 * T'Mantissa
4975 Fold_Uint (N, 4 * Mantissa, True);
4981 when Attribute_Enum_Rep =>
4983 -- For an enumeration type with a non-standard representation use
4984 -- the Enumeration_Rep field of the proper constant. Note that this
4985 -- will not work for types Character/Wide_[Wide-]Character, since no
4986 -- real entities are created for the enumeration literals, but that
4987 -- does not matter since these two types do not have non-standard
4988 -- representations anyway.
4990 if Is_Enumeration_Type (P_Type)
4991 and then Has_Non_Standard_Rep (P_Type)
4993 Fold_Uint (N, Enumeration_Rep (Expr_Value_E (E1)), Static);
4995 -- For enumeration types with standard representations and all
4996 -- other cases (i.e. all integer and modular types), Enum_Rep
4997 -- is equivalent to Pos.
5000 Fold_Uint (N, Expr_Value (E1), Static);
5007 when Attribute_Epsilon =>
5009 -- Ada 83 attribute is defined as (RM83 3.5.8)
5011 -- T'Epsilon = 2.0**(1 - T'Mantissa)
5013 Fold_Ureal (N, Ureal_2 ** (1 - Mantissa), True);
5019 when Attribute_Exponent =>
5021 Eval_Fat.Exponent (P_Root_Type, Expr_Value_R (E1)), Static);
5027 when Attribute_First => First_Attr :
5031 if Compile_Time_Known_Value (Lo_Bound) then
5032 if Is_Real_Type (P_Type) then
5033 Fold_Ureal (N, Expr_Value_R (Lo_Bound), Static);
5035 Fold_Uint (N, Expr_Value (Lo_Bound), Static);
5044 when Attribute_Fixed_Value =>
5051 when Attribute_Floor =>
5053 Eval_Fat.Floor (P_Root_Type, Expr_Value_R (E1)), Static);
5059 when Attribute_Fore =>
5060 if Compile_Time_Known_Bounds (P_Type) then
5061 Fold_Uint (N, UI_From_Int (Fore_Value), Static);
5068 when Attribute_Fraction =>
5070 Eval_Fat.Fraction (P_Root_Type, Expr_Value_R (E1)), Static);
5072 -----------------------
5073 -- Has_Access_Values --
5074 -----------------------
5076 when Attribute_Has_Access_Values =>
5077 Rewrite (N, New_Occurrence_Of
5078 (Boolean_Literals (Has_Access_Values (P_Root_Type)), Loc));
5079 Analyze_And_Resolve (N, Standard_Boolean);
5081 -----------------------
5082 -- Has_Discriminants --
5083 -----------------------
5085 when Attribute_Has_Discriminants =>
5086 Rewrite (N, New_Occurrence_Of (
5087 Boolean_Literals (Has_Discriminants (P_Entity)), Loc));
5088 Analyze_And_Resolve (N, Standard_Boolean);
5094 when Attribute_Identity =>
5101 -- Image is a scalar attribute, but is never static, because it is
5102 -- not a static function (having a non-scalar argument (RM 4.9(22))
5104 when Attribute_Image =>
5111 -- Img is a scalar attribute, but is never static, because it is
5112 -- not a static function (having a non-scalar argument (RM 4.9(22))
5114 when Attribute_Img =>
5121 when Attribute_Integer_Value =>
5128 when Attribute_Large =>
5130 -- For fixed-point, we use the identity:
5132 -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small
5134 if Is_Fixed_Point_Type (P_Type) then
5136 Make_Op_Multiply (Loc,
5138 Make_Op_Subtract (Loc,
5142 Make_Real_Literal (Loc, Ureal_2),
5144 Make_Attribute_Reference (Loc,
5146 Attribute_Name => Name_Mantissa)),
5147 Right_Opnd => Make_Real_Literal (Loc, Ureal_1)),
5150 Make_Real_Literal (Loc, Small_Value (Entity (P)))));
5152 Analyze_And_Resolve (N, C_Type);
5154 -- Floating-point (Ada 83 compatibility)
5157 -- Ada 83 attribute is defined as (RM83 3.5.8)
5159 -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa))
5163 -- T'Emax = 4 * T'Mantissa
5166 Ureal_2 ** (4 * Mantissa) * (Ureal_1 - Ureal_2 ** (-Mantissa)),
5174 when Attribute_Last => Last :
5178 if Compile_Time_Known_Value (Hi_Bound) then
5179 if Is_Real_Type (P_Type) then
5180 Fold_Ureal (N, Expr_Value_R (Hi_Bound), Static);
5182 Fold_Uint (N, Expr_Value (Hi_Bound), Static);
5191 when Attribute_Leading_Part =>
5193 Eval_Fat.Leading_Part
5194 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
5200 when Attribute_Length => Length : declare
5204 -- In the case of a generic index type, the bounds may
5205 -- appear static but the computation is not meaningful,
5206 -- and may generate a spurious warning.
5208 Ind := First_Index (P_Type);
5210 while Present (Ind) loop
5211 if Is_Generic_Type (Etype (Ind)) then
5220 if Compile_Time_Known_Value (Lo_Bound)
5221 and then Compile_Time_Known_Value (Hi_Bound)
5224 UI_Max (0, 1 + (Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound))),
5233 when Attribute_Machine =>
5236 (P_Root_Type, Expr_Value_R (E1), Eval_Fat.Round, N),
5243 when Attribute_Machine_Emax =>
5244 Float_Attribute_Universal_Integer (
5252 AAMPL_Machine_Emax);
5258 when Attribute_Machine_Emin =>
5259 Float_Attribute_Universal_Integer (
5267 AAMPL_Machine_Emin);
5269 ----------------------
5270 -- Machine_Mantissa --
5271 ----------------------
5273 when Attribute_Machine_Mantissa =>
5274 Float_Attribute_Universal_Integer (
5275 IEEES_Machine_Mantissa,
5276 IEEEL_Machine_Mantissa,
5277 IEEEX_Machine_Mantissa,
5278 VAXFF_Machine_Mantissa,
5279 VAXDF_Machine_Mantissa,
5280 VAXGF_Machine_Mantissa,
5281 AAMPS_Machine_Mantissa,
5282 AAMPL_Machine_Mantissa);
5284 -----------------------
5285 -- Machine_Overflows --
5286 -----------------------
5288 when Attribute_Machine_Overflows =>
5290 -- Always true for fixed-point
5292 if Is_Fixed_Point_Type (P_Type) then
5293 Fold_Uint (N, True_Value, True);
5295 -- Floating point case
5299 UI_From_Int (Boolean'Pos (Machine_Overflows_On_Target)),
5307 when Attribute_Machine_Radix =>
5308 if Is_Fixed_Point_Type (P_Type) then
5309 if Is_Decimal_Fixed_Point_Type (P_Type)
5310 and then Machine_Radix_10 (P_Type)
5312 Fold_Uint (N, Uint_10, True);
5314 Fold_Uint (N, Uint_2, True);
5317 -- All floating-point type always have radix 2
5320 Fold_Uint (N, Uint_2, True);
5323 --------------------
5324 -- Machine_Rounds --
5325 --------------------
5327 when Attribute_Machine_Rounds =>
5329 -- Always False for fixed-point
5331 if Is_Fixed_Point_Type (P_Type) then
5332 Fold_Uint (N, False_Value, True);
5334 -- Else yield proper floating-point result
5338 (N, UI_From_Int (Boolean'Pos (Machine_Rounds_On_Target)), True);
5345 -- Note: Machine_Size is identical to Object_Size
5347 when Attribute_Machine_Size => Machine_Size : declare
5348 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
5351 if Known_Esize (P_TypeA) then
5352 Fold_Uint (N, Esize (P_TypeA), True);
5360 when Attribute_Mantissa =>
5362 -- Fixed-point mantissa
5364 if Is_Fixed_Point_Type (P_Type) then
5366 -- Compile time foldable case
5368 if Compile_Time_Known_Value (Type_Low_Bound (P_Type))
5370 Compile_Time_Known_Value (Type_High_Bound (P_Type))
5372 -- The calculation of the obsolete Ada 83 attribute Mantissa
5373 -- is annoying, because of AI00143, quoted here:
5375 -- !question 84-01-10
5377 -- Consider the model numbers for F:
5379 -- type F is delta 1.0 range -7.0 .. 8.0;
5381 -- The wording requires that F'MANTISSA be the SMALLEST
5382 -- integer number for which each bound of the specified
5383 -- range is either a model number or lies at most small
5384 -- distant from a model number. This means F'MANTISSA
5385 -- is required to be 3 since the range -7.0 .. 7.0 fits
5386 -- in 3 signed bits, and 8 is "at most" 1.0 from a model
5387 -- number, namely, 7. Is this analysis correct? Note that
5388 -- this implies the upper bound of the range is not
5389 -- represented as a model number.
5391 -- !response 84-03-17
5393 -- The analysis is correct. The upper and lower bounds for
5394 -- a fixed point type can lie outside the range of model
5405 LBound := Expr_Value_R (Type_Low_Bound (P_Type));
5406 UBound := Expr_Value_R (Type_High_Bound (P_Type));
5407 Bound := UR_Max (UR_Abs (LBound), UR_Abs (UBound));
5408 Max_Man := UR_Trunc (Bound / Small_Value (P_Type));
5410 -- If the Bound is exactly a model number, i.e. a multiple
5411 -- of Small, then we back it off by one to get the integer
5412 -- value that must be representable.
5414 if Small_Value (P_Type) * Max_Man = Bound then
5415 Max_Man := Max_Man - 1;
5418 -- Now find corresponding size = Mantissa value
5421 while 2 ** Siz < Max_Man loop
5425 Fold_Uint (N, Siz, True);
5429 -- The case of dynamic bounds cannot be evaluated at compile
5430 -- time. Instead we use a runtime routine (see Exp_Attr).
5435 -- Floating-point Mantissa
5438 Fold_Uint (N, Mantissa, True);
5445 when Attribute_Max => Max :
5447 if Is_Real_Type (P_Type) then
5449 (N, UR_Max (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
5451 Fold_Uint (N, UI_Max (Expr_Value (E1), Expr_Value (E2)), Static);
5455 ----------------------------------
5456 -- Max_Size_In_Storage_Elements --
5457 ----------------------------------
5459 -- Max_Size_In_Storage_Elements is simply the Size rounded up to a
5460 -- Storage_Unit boundary. We can fold any cases for which the size
5461 -- is known by the front end.
5463 when Attribute_Max_Size_In_Storage_Elements =>
5464 if Known_Esize (P_Type) then
5466 (Esize (P_Type) + System_Storage_Unit - 1) /
5467 System_Storage_Unit,
5471 --------------------
5472 -- Mechanism_Code --
5473 --------------------
5475 when Attribute_Mechanism_Code =>
5479 Mech : Mechanism_Type;
5483 Mech := Mechanism (P_Entity);
5486 Val := UI_To_Int (Expr_Value (E1));
5488 Formal := First_Formal (P_Entity);
5489 for J in 1 .. Val - 1 loop
5490 Next_Formal (Formal);
5492 Mech := Mechanism (Formal);
5496 Fold_Uint (N, UI_From_Int (Int (-Mech)), True);
5504 when Attribute_Min => Min :
5506 if Is_Real_Type (P_Type) then
5508 (N, UR_Min (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
5511 (N, UI_Min (Expr_Value (E1), Expr_Value (E2)), Static);
5519 when Attribute_Mod =>
5521 (N, UI_Mod (Expr_Value (E1), Modulus (P_Base_Type)), Static);
5527 when Attribute_Model =>
5529 Eval_Fat.Model (P_Root_Type, Expr_Value_R (E1)), Static);
5535 when Attribute_Model_Emin =>
5536 Float_Attribute_Universal_Integer (
5550 when Attribute_Model_Epsilon =>
5551 Float_Attribute_Universal_Real (
5552 IEEES_Model_Epsilon'Universal_Literal_String,
5553 IEEEL_Model_Epsilon'Universal_Literal_String,
5554 IEEEX_Model_Epsilon'Universal_Literal_String,
5555 VAXFF_Model_Epsilon'Universal_Literal_String,
5556 VAXDF_Model_Epsilon'Universal_Literal_String,
5557 VAXGF_Model_Epsilon'Universal_Literal_String,
5558 AAMPS_Model_Epsilon'Universal_Literal_String,
5559 AAMPL_Model_Epsilon'Universal_Literal_String);
5561 --------------------
5562 -- Model_Mantissa --
5563 --------------------
5565 when Attribute_Model_Mantissa =>
5566 Float_Attribute_Universal_Integer (
5567 IEEES_Model_Mantissa,
5568 IEEEL_Model_Mantissa,
5569 IEEEX_Model_Mantissa,
5570 VAXFF_Model_Mantissa,
5571 VAXDF_Model_Mantissa,
5572 VAXGF_Model_Mantissa,
5573 AAMPS_Model_Mantissa,
5574 AAMPL_Model_Mantissa);
5580 when Attribute_Model_Small =>
5581 Float_Attribute_Universal_Real (
5582 IEEES_Model_Small'Universal_Literal_String,
5583 IEEEL_Model_Small'Universal_Literal_String,
5584 IEEEX_Model_Small'Universal_Literal_String,
5585 VAXFF_Model_Small'Universal_Literal_String,
5586 VAXDF_Model_Small'Universal_Literal_String,
5587 VAXGF_Model_Small'Universal_Literal_String,
5588 AAMPS_Model_Small'Universal_Literal_String,
5589 AAMPL_Model_Small'Universal_Literal_String);
5595 when Attribute_Modulus =>
5596 Fold_Uint (N, Modulus (P_Type), True);
5598 --------------------
5599 -- Null_Parameter --
5600 --------------------
5602 -- Cannot fold, we know the value sort of, but the whole point is
5603 -- that there is no way to talk about this imaginary value except
5604 -- by using the attribute, so we leave it the way it is.
5606 when Attribute_Null_Parameter =>
5613 -- The Object_Size attribute for a type returns the Esize of the
5614 -- type and can be folded if this value is known.
5616 when Attribute_Object_Size => Object_Size : declare
5617 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
5620 if Known_Esize (P_TypeA) then
5621 Fold_Uint (N, Esize (P_TypeA), True);
5625 -------------------------
5626 -- Passed_By_Reference --
5627 -------------------------
5629 -- Scalar types are never passed by reference
5631 when Attribute_Passed_By_Reference =>
5632 Fold_Uint (N, False_Value, True);
5638 when Attribute_Pos =>
5639 Fold_Uint (N, Expr_Value (E1), True);
5645 when Attribute_Pred => Pred :
5647 -- Floating-point case
5649 if Is_Floating_Point_Type (P_Type) then
5651 Eval_Fat.Pred (P_Root_Type, Expr_Value_R (E1)), Static);
5655 elsif Is_Fixed_Point_Type (P_Type) then
5657 Expr_Value_R (E1) - Small_Value (P_Type), True);
5659 -- Modular integer case (wraps)
5661 elsif Is_Modular_Integer_Type (P_Type) then
5662 Fold_Uint (N, (Expr_Value (E1) - 1) mod Modulus (P_Type), Static);
5664 -- Other scalar cases
5667 pragma Assert (Is_Scalar_Type (P_Type));
5669 if Is_Enumeration_Type (P_Type)
5670 and then Expr_Value (E1) =
5671 Expr_Value (Type_Low_Bound (P_Base_Type))
5673 Apply_Compile_Time_Constraint_Error
5674 (N, "Pred of `&''First`",
5675 CE_Overflow_Check_Failed,
5677 Warn => not Static);
5683 Fold_Uint (N, Expr_Value (E1) - 1, Static);
5691 -- No processing required, because by this stage, Range has been
5692 -- replaced by First .. Last, so this branch can never be taken.
5694 when Attribute_Range =>
5695 raise Program_Error;
5701 when Attribute_Range_Length =>
5704 if Compile_Time_Known_Value (Hi_Bound)
5705 and then Compile_Time_Known_Value (Lo_Bound)
5709 (0, Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound) + 1),
5717 when Attribute_Remainder => Remainder : declare
5718 X : constant Ureal := Expr_Value_R (E1);
5719 Y : constant Ureal := Expr_Value_R (E2);
5722 if UR_Is_Zero (Y) then
5723 Apply_Compile_Time_Constraint_Error
5724 (N, "division by zero in Remainder",
5725 CE_Overflow_Check_Failed,
5726 Warn => not Static);
5732 Fold_Ureal (N, Eval_Fat.Remainder (P_Root_Type, X, Y), Static);
5739 when Attribute_Round => Round :
5745 -- First we get the (exact result) in units of small
5747 Sr := Expr_Value_R (E1) / Small_Value (C_Type);
5749 -- Now round that exactly to an integer
5751 Si := UR_To_Uint (Sr);
5753 -- Finally the result is obtained by converting back to real
5755 Fold_Ureal (N, Si * Small_Value (C_Type), Static);
5762 when Attribute_Rounding =>
5764 Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static);
5770 when Attribute_Safe_Emax =>
5771 Float_Attribute_Universal_Integer (
5785 when Attribute_Safe_First =>
5786 Float_Attribute_Universal_Real (
5787 IEEES_Safe_First'Universal_Literal_String,
5788 IEEEL_Safe_First'Universal_Literal_String,
5789 IEEEX_Safe_First'Universal_Literal_String,
5790 VAXFF_Safe_First'Universal_Literal_String,
5791 VAXDF_Safe_First'Universal_Literal_String,
5792 VAXGF_Safe_First'Universal_Literal_String,
5793 AAMPS_Safe_First'Universal_Literal_String,
5794 AAMPL_Safe_First'Universal_Literal_String);
5800 when Attribute_Safe_Large =>
5801 if Is_Fixed_Point_Type (P_Type) then
5803 (N, Expr_Value_R (Type_High_Bound (P_Base_Type)), Static);
5805 Float_Attribute_Universal_Real (
5806 IEEES_Safe_Large'Universal_Literal_String,
5807 IEEEL_Safe_Large'Universal_Literal_String,
5808 IEEEX_Safe_Large'Universal_Literal_String,
5809 VAXFF_Safe_Large'Universal_Literal_String,
5810 VAXDF_Safe_Large'Universal_Literal_String,
5811 VAXGF_Safe_Large'Universal_Literal_String,
5812 AAMPS_Safe_Large'Universal_Literal_String,
5813 AAMPL_Safe_Large'Universal_Literal_String);
5820 when Attribute_Safe_Last =>
5821 Float_Attribute_Universal_Real (
5822 IEEES_Safe_Last'Universal_Literal_String,
5823 IEEEL_Safe_Last'Universal_Literal_String,
5824 IEEEX_Safe_Last'Universal_Literal_String,
5825 VAXFF_Safe_Last'Universal_Literal_String,
5826 VAXDF_Safe_Last'Universal_Literal_String,
5827 VAXGF_Safe_Last'Universal_Literal_String,
5828 AAMPS_Safe_Last'Universal_Literal_String,
5829 AAMPL_Safe_Last'Universal_Literal_String);
5835 when Attribute_Safe_Small =>
5837 -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant
5838 -- for fixed-point, since is the same as Small, but we implement
5839 -- it for backwards compatibility.
5841 if Is_Fixed_Point_Type (P_Type) then
5842 Fold_Ureal (N, Small_Value (P_Type), Static);
5844 -- Ada 83 Safe_Small for floating-point cases
5847 Float_Attribute_Universal_Real (
5848 IEEES_Safe_Small'Universal_Literal_String,
5849 IEEEL_Safe_Small'Universal_Literal_String,
5850 IEEEX_Safe_Small'Universal_Literal_String,
5851 VAXFF_Safe_Small'Universal_Literal_String,
5852 VAXDF_Safe_Small'Universal_Literal_String,
5853 VAXGF_Safe_Small'Universal_Literal_String,
5854 AAMPS_Safe_Small'Universal_Literal_String,
5855 AAMPL_Safe_Small'Universal_Literal_String);
5862 when Attribute_Scale =>
5863 Fold_Uint (N, Scale_Value (P_Type), True);
5869 when Attribute_Scaling =>
5872 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
5878 when Attribute_Signed_Zeros =>
5880 (N, UI_From_Int (Boolean'Pos (Signed_Zeros_On_Target)), Static);
5886 -- Size attribute returns the RM size. All scalar types can be folded,
5887 -- as well as any types for which the size is known by the front end,
5888 -- including any type for which a size attribute is specified.
5890 when Attribute_Size | Attribute_VADS_Size => Size : declare
5891 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
5894 if RM_Size (P_TypeA) /= Uint_0 then
5898 if Id = Attribute_VADS_Size or else Use_VADS_Size then
5900 S : constant Node_Id := Size_Clause (P_TypeA);
5903 -- If a size clause applies, then use the size from it.
5904 -- This is one of the rare cases where we can use the
5905 -- Size_Clause field for a subtype when Has_Size_Clause
5906 -- is False. Consider:
5908 -- type x is range 1 .. 64;
5909 -- for x'size use 12;
5910 -- subtype y is x range 0 .. 3;
5912 -- Here y has a size clause inherited from x, but normally
5913 -- it does not apply, and y'size is 2. However, y'VADS_Size
5914 -- is indeed 12 and not 2.
5917 and then Is_OK_Static_Expression (Expression (S))
5919 Fold_Uint (N, Expr_Value (Expression (S)), True);
5921 -- If no size is specified, then we simply use the object
5922 -- size in the VADS_Size case (e.g. Natural'Size is equal
5923 -- to Integer'Size, not one less).
5926 Fold_Uint (N, Esize (P_TypeA), True);
5930 -- Normal case (Size) in which case we want the RM_Size
5935 Static and then Is_Discrete_Type (P_TypeA));
5944 when Attribute_Small =>
5946 -- The floating-point case is present only for Ada 83 compatability.
5947 -- Note that strictly this is an illegal addition, since we are
5948 -- extending an Ada 95 defined attribute, but we anticipate an
5949 -- ARG ruling that will permit this.
5951 if Is_Floating_Point_Type (P_Type) then
5953 -- Ada 83 attribute is defined as (RM83 3.5.8)
5955 -- T'Small = 2.0**(-T'Emax - 1)
5959 -- T'Emax = 4 * T'Mantissa
5961 Fold_Ureal (N, Ureal_2 ** ((-(4 * Mantissa)) - 1), Static);
5963 -- Normal Ada 95 fixed-point case
5966 Fold_Ureal (N, Small_Value (P_Type), True);
5973 when Attribute_Stream_Size =>
5980 when Attribute_Succ => Succ :
5982 -- Floating-point case
5984 if Is_Floating_Point_Type (P_Type) then
5986 Eval_Fat.Succ (P_Root_Type, Expr_Value_R (E1)), Static);
5990 elsif Is_Fixed_Point_Type (P_Type) then
5992 Expr_Value_R (E1) + Small_Value (P_Type), Static);
5994 -- Modular integer case (wraps)
5996 elsif Is_Modular_Integer_Type (P_Type) then
5997 Fold_Uint (N, (Expr_Value (E1) + 1) mod Modulus (P_Type), Static);
5999 -- Other scalar cases
6002 pragma Assert (Is_Scalar_Type (P_Type));
6004 if Is_Enumeration_Type (P_Type)
6005 and then Expr_Value (E1) =
6006 Expr_Value (Type_High_Bound (P_Base_Type))
6008 Apply_Compile_Time_Constraint_Error
6009 (N, "Succ of `&''Last`",
6010 CE_Overflow_Check_Failed,
6012 Warn => not Static);
6017 Fold_Uint (N, Expr_Value (E1) + 1, Static);
6026 when Attribute_Truncation =>
6028 Eval_Fat.Truncation (P_Root_Type, Expr_Value_R (E1)), Static);
6034 when Attribute_Type_Class => Type_Class : declare
6035 Typ : constant Entity_Id := Underlying_Type (P_Base_Type);
6039 if Is_Descendent_Of_Address (Typ) then
6040 Id := RE_Type_Class_Address;
6042 elsif Is_Enumeration_Type (Typ) then
6043 Id := RE_Type_Class_Enumeration;
6045 elsif Is_Integer_Type (Typ) then
6046 Id := RE_Type_Class_Integer;
6048 elsif Is_Fixed_Point_Type (Typ) then
6049 Id := RE_Type_Class_Fixed_Point;
6051 elsif Is_Floating_Point_Type (Typ) then
6052 Id := RE_Type_Class_Floating_Point;
6054 elsif Is_Array_Type (Typ) then
6055 Id := RE_Type_Class_Array;
6057 elsif Is_Record_Type (Typ) then
6058 Id := RE_Type_Class_Record;
6060 elsif Is_Access_Type (Typ) then
6061 Id := RE_Type_Class_Access;
6063 elsif Is_Enumeration_Type (Typ) then
6064 Id := RE_Type_Class_Enumeration;
6066 elsif Is_Task_Type (Typ) then
6067 Id := RE_Type_Class_Task;
6069 -- We treat protected types like task types. It would make more
6070 -- sense to have another enumeration value, but after all the
6071 -- whole point of this feature is to be exactly DEC compatible,
6072 -- and changing the type Type_Clas would not meet this requirement.
6074 elsif Is_Protected_Type (Typ) then
6075 Id := RE_Type_Class_Task;
6077 -- Not clear if there are any other possibilities, but if there
6078 -- are, then we will treat them as the address case.
6081 Id := RE_Type_Class_Address;
6084 Rewrite (N, New_Occurrence_Of (RTE (Id), Loc));
6088 -----------------------
6089 -- Unbiased_Rounding --
6090 -----------------------
6092 when Attribute_Unbiased_Rounding =>
6094 Eval_Fat.Unbiased_Rounding (P_Root_Type, Expr_Value_R (E1)),
6097 -------------------------
6098 -- Unconstrained_Array --
6099 -------------------------
6101 when Attribute_Unconstrained_Array => Unconstrained_Array : declare
6102 Typ : constant Entity_Id := Underlying_Type (P_Type);
6105 Rewrite (N, New_Occurrence_Of (
6107 Is_Array_Type (P_Type)
6108 and then not Is_Constrained (Typ)), Loc));
6110 -- Analyze and resolve as boolean, note that this attribute is
6111 -- a static attribute in GNAT.
6113 Analyze_And_Resolve (N, Standard_Boolean);
6115 end Unconstrained_Array;
6121 -- Processing is shared with Size
6127 when Attribute_Val => Val :
6129 if Expr_Value (E1) < Expr_Value (Type_Low_Bound (P_Base_Type))
6131 Expr_Value (E1) > Expr_Value (Type_High_Bound (P_Base_Type))
6133 Apply_Compile_Time_Constraint_Error
6134 (N, "Val expression out of range",
6135 CE_Range_Check_Failed,
6136 Warn => not Static);
6142 Fold_Uint (N, Expr_Value (E1), Static);
6150 -- The Value_Size attribute for a type returns the RM size of the
6151 -- type. This an always be folded for scalar types, and can also
6152 -- be folded for non-scalar types if the size is set.
6154 when Attribute_Value_Size => Value_Size : declare
6155 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6158 if RM_Size (P_TypeA) /= Uint_0 then
6159 Fold_Uint (N, RM_Size (P_TypeA), True);
6168 -- Version can never be static
6170 when Attribute_Version =>
6177 -- Wide_Image is a scalar attribute, but is never static, because it
6178 -- is not a static function (having a non-scalar argument (RM 4.9(22))
6180 when Attribute_Wide_Image =>
6183 ---------------------
6184 -- Wide_Wide_Image --
6185 ---------------------
6187 -- Wide_Wide_Image is a scalar attribute but is never static, because it
6188 -- is not a static function (having a non-scalar argument (RM 4.9(22)).
6190 when Attribute_Wide_Wide_Image =>
6193 ---------------------
6194 -- Wide_Wide_Width --
6195 ---------------------
6197 -- Processing for Wide_Wide_Width is combined with Width
6203 -- Processing for Wide_Width is combined with Width
6209 -- This processing also handles the case of Wide_[Wide_]Width
6211 when Attribute_Width |
6212 Attribute_Wide_Width |
6213 Attribute_Wide_Wide_Width => Width :
6215 if Compile_Time_Known_Bounds (P_Type) then
6217 -- Floating-point types
6219 if Is_Floating_Point_Type (P_Type) then
6221 -- Width is zero for a null range (RM 3.5 (38))
6223 if Expr_Value_R (Type_High_Bound (P_Type)) <
6224 Expr_Value_R (Type_Low_Bound (P_Type))
6226 Fold_Uint (N, Uint_0, True);
6229 -- For floating-point, we have +N.dddE+nnn where length
6230 -- of ddd is determined by type'Digits - 1, but is one
6231 -- if Digits is one (RM 3.5 (33)).
6233 -- nnn is set to 2 for Short_Float and Float (32 bit
6234 -- floats), and 3 for Long_Float and Long_Long_Float.
6235 -- This is not quite right, but is good enough.
6239 Int'Max (2, UI_To_Int (Digits_Value (P_Type)));
6242 if Esize (P_Type) <= 32 then
6248 Fold_Uint (N, UI_From_Int (Len), True);
6252 -- Fixed-point types
6254 elsif Is_Fixed_Point_Type (P_Type) then
6256 -- Width is zero for a null range (RM 3.5 (38))
6258 if Expr_Value (Type_High_Bound (P_Type)) <
6259 Expr_Value (Type_Low_Bound (P_Type))
6261 Fold_Uint (N, Uint_0, True);
6263 -- The non-null case depends on the specific real type
6266 -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34))
6269 (N, UI_From_Int (Fore_Value + 1 + Aft_Value), True);
6276 R : constant Entity_Id := Root_Type (P_Type);
6277 Lo : constant Uint :=
6278 Expr_Value (Type_Low_Bound (P_Type));
6279 Hi : constant Uint :=
6280 Expr_Value (Type_High_Bound (P_Type));
6293 -- Width for types derived from Standard.Character
6294 -- and Standard.Wide_[Wide_]Character.
6296 elsif R = Standard_Character
6297 or else R = Standard_Wide_Character
6298 or else R = Standard_Wide_Wide_Character
6302 -- Set W larger if needed
6304 for J in UI_To_Int (Lo) .. UI_To_Int (Hi) loop
6306 -- Assume all wide-character escape sequences are
6307 -- same length, so we can quit when we reach one.
6309 -- Is this right for UTF-8?
6312 if Id = Attribute_Wide_Width then
6313 W := Int'Max (W, 3);
6316 W := Int'Max (W, Length_Wide);
6321 C := Character'Val (J);
6323 -- Test for all cases where Character'Image
6324 -- yields an image that is longer than three
6325 -- characters. First the cases of Reserved_xxx
6326 -- names (length = 12).
6329 when Reserved_128 | Reserved_129 |
6330 Reserved_132 | Reserved_153
6334 when BS | HT | LF | VT | FF | CR |
6335 SO | SI | EM | FS | GS | RS |
6336 US | RI | MW | ST | PM
6340 when NUL | SOH | STX | ETX | EOT |
6341 ENQ | ACK | BEL | DLE | DC1 |
6342 DC2 | DC3 | DC4 | NAK | SYN |
6343 ETB | CAN | SUB | ESC | DEL |
6344 BPH | NBH | NEL | SSA | ESA |
6345 HTS | HTJ | VTS | PLD | PLU |
6346 SS2 | SS3 | DCS | PU1 | PU2 |
6347 STS | CCH | SPA | EPA | SOS |
6348 SCI | CSI | OSC | APC
6352 when Space .. Tilde |
6353 No_Break_Space .. LC_Y_Diaeresis
6358 W := Int'Max (W, Wt);
6362 -- Width for types derived from Standard.Boolean
6364 elsif R = Standard_Boolean then
6371 -- Width for integer types
6373 elsif Is_Integer_Type (P_Type) then
6374 T := UI_Max (abs Lo, abs Hi);
6382 -- Only remaining possibility is user declared enum type
6385 pragma Assert (Is_Enumeration_Type (P_Type));
6388 L := First_Literal (P_Type);
6390 while Present (L) loop
6392 -- Only pay attention to in range characters
6394 if Lo <= Enumeration_Pos (L)
6395 and then Enumeration_Pos (L) <= Hi
6397 -- For Width case, use decoded name
6399 if Id = Attribute_Width then
6400 Get_Decoded_Name_String (Chars (L));
6401 Wt := Nat (Name_Len);
6403 -- For Wide_[Wide_]Width, use encoded name, and
6404 -- then adjust for the encoding.
6407 Get_Name_String (Chars (L));
6409 -- Character literals are always of length 3
6411 if Name_Buffer (1) = 'Q' then
6414 -- Otherwise loop to adjust for upper/wide chars
6417 Wt := Nat (Name_Len);
6419 for J in 1 .. Name_Len loop
6420 if Name_Buffer (J) = 'U' then
6422 elsif Name_Buffer (J) = 'W' then
6429 W := Int'Max (W, Wt);
6436 Fold_Uint (N, UI_From_Int (W), True);
6442 -- The following attributes can never be folded, and furthermore we
6443 -- should not even have entered the case statement for any of these.
6444 -- Note that in some cases, the values have already been folded as
6445 -- a result of the processing in Analyze_Attribute.
6447 when Attribute_Abort_Signal |
6450 Attribute_Address_Size |
6451 Attribute_Asm_Input |
6452 Attribute_Asm_Output |
6454 Attribute_Bit_Order |
6455 Attribute_Bit_Position |
6456 Attribute_Callable |
6459 Attribute_Code_Address |
6461 Attribute_Default_Bit_Order |
6462 Attribute_Elaborated |
6463 Attribute_Elab_Body |
6464 Attribute_Elab_Spec |
6465 Attribute_External_Tag |
6466 Attribute_First_Bit |
6468 Attribute_Last_Bit |
6469 Attribute_Maximum_Alignment |
6471 Attribute_Partition_ID |
6472 Attribute_Pool_Address |
6473 Attribute_Position |
6475 Attribute_Storage_Pool |
6476 Attribute_Storage_Size |
6477 Attribute_Storage_Unit |
6479 Attribute_Target_Name |
6480 Attribute_Terminated |
6481 Attribute_To_Address |
6482 Attribute_UET_Address |
6483 Attribute_Unchecked_Access |
6484 Attribute_Universal_Literal_String |
6485 Attribute_Unrestricted_Access |
6488 Attribute_Wchar_T_Size |
6489 Attribute_Wide_Value |
6490 Attribute_Wide_Wide_Value |
6491 Attribute_Word_Size |
6494 raise Program_Error;
6497 -- At the end of the case, one more check. If we did a static evaluation
6498 -- so that the result is now a literal, then set Is_Static_Expression
6499 -- in the constant only if the prefix type is a static subtype. For
6500 -- non-static subtypes, the folding is still OK, but not static.
6502 -- An exception is the GNAT attribute Constrained_Array which is
6503 -- defined to be a static attribute in all cases.
6505 if Nkind (N) = N_Integer_Literal
6506 or else Nkind (N) = N_Real_Literal
6507 or else Nkind (N) = N_Character_Literal
6508 or else Nkind (N) = N_String_Literal
6509 or else (Is_Entity_Name (N)
6510 and then Ekind (Entity (N)) = E_Enumeration_Literal)
6512 Set_Is_Static_Expression (N, Static);
6514 -- If this is still an attribute reference, then it has not been folded
6515 -- and that means that its expressions are in a non-static context.
6517 elsif Nkind (N) = N_Attribute_Reference then
6520 -- Note: the else case not covered here are odd cases where the
6521 -- processing has transformed the attribute into something other
6522 -- than a constant. Nothing more to do in such cases.
6530 ------------------------------
6531 -- Is_Anonymous_Tagged_Base --
6532 ------------------------------
6534 function Is_Anonymous_Tagged_Base
6541 Anon = Current_Scope
6542 and then Is_Itype (Anon)
6543 and then Associated_Node_For_Itype (Anon) = Parent (Typ);
6544 end Is_Anonymous_Tagged_Base;
6546 -----------------------
6547 -- Resolve_Attribute --
6548 -----------------------
6550 procedure Resolve_Attribute (N : Node_Id; Typ : Entity_Id) is
6551 Loc : constant Source_Ptr := Sloc (N);
6552 P : constant Node_Id := Prefix (N);
6553 Aname : constant Name_Id := Attribute_Name (N);
6554 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
6555 Btyp : constant Entity_Id := Base_Type (Typ);
6556 Index : Interp_Index;
6558 Nom_Subt : Entity_Id;
6560 procedure Accessibility_Message;
6561 -- Error, or warning within an instance, if the static accessibility
6562 -- rules of 3.10.2 are violated.
6564 ---------------------------
6565 -- Accessibility_Message --
6566 ---------------------------
6568 procedure Accessibility_Message is
6569 Indic : Node_Id := Parent (Parent (N));
6572 -- In an instance, this is a runtime check, but one we
6573 -- know will fail, so generate an appropriate warning.
6575 if In_Instance_Body then
6577 ("?non-local pointer cannot point to local object", P);
6579 ("?Program_Error will be raised at run time", P);
6581 Make_Raise_Program_Error (Loc,
6582 Reason => PE_Accessibility_Check_Failed));
6588 ("non-local pointer cannot point to local object", P);
6590 -- Check for case where we have a missing access definition
6592 if Is_Record_Type (Current_Scope)
6594 (Nkind (Parent (N)) = N_Discriminant_Association
6596 Nkind (Parent (N)) = N_Index_Or_Discriminant_Constraint)
6598 Indic := Parent (Parent (N));
6599 while Present (Indic)
6600 and then Nkind (Indic) /= N_Subtype_Indication
6602 Indic := Parent (Indic);
6605 if Present (Indic) then
6607 ("\use an access definition for" &
6608 " the access discriminant of&", N,
6609 Entity (Subtype_Mark (Indic)));
6613 end Accessibility_Message;
6615 -- Start of processing for Resolve_Attribute
6618 -- If error during analysis, no point in continuing, except for
6619 -- array types, where we get better recovery by using unconstrained
6620 -- indices than nothing at all (see Check_Array_Type).
6623 and then Attr_Id /= Attribute_First
6624 and then Attr_Id /= Attribute_Last
6625 and then Attr_Id /= Attribute_Length
6626 and then Attr_Id /= Attribute_Range
6631 -- If attribute was universal type, reset to actual type
6633 if Etype (N) = Universal_Integer
6634 or else Etype (N) = Universal_Real
6639 -- Remaining processing depends on attribute
6647 -- For access attributes, if the prefix denotes an entity, it is
6648 -- interpreted as a name, never as a call. It may be overloaded,
6649 -- in which case resolution uses the profile of the context type.
6650 -- Otherwise prefix must be resolved.
6652 when Attribute_Access
6653 | Attribute_Unchecked_Access
6654 | Attribute_Unrestricted_Access =>
6656 if Is_Variable (P) then
6657 Note_Possible_Modification (P);
6660 if Is_Entity_Name (P) then
6661 if Is_Overloaded (P) then
6662 Get_First_Interp (P, Index, It);
6664 while Present (It.Nam) loop
6666 if Type_Conformant (Designated_Type (Typ), It.Nam) then
6667 Set_Entity (P, It.Nam);
6669 -- The prefix is definitely NOT overloaded anymore
6670 -- at this point, so we reset the Is_Overloaded
6671 -- flag to avoid any confusion when reanalyzing
6674 Set_Is_Overloaded (P, False);
6675 Generate_Reference (Entity (P), P);
6679 Get_Next_Interp (Index, It);
6682 -- If it is a subprogram name or a type, there is nothing
6685 elsif not Is_Overloadable (Entity (P))
6686 and then not Is_Type (Entity (P))
6691 Error_Msg_Name_1 := Aname;
6693 if not Is_Entity_Name (P) then
6696 elsif Is_Abstract (Entity (P))
6697 and then Is_Overloadable (Entity (P))
6699 Error_Msg_N ("prefix of % attribute cannot be abstract", P);
6700 Set_Etype (N, Any_Type);
6702 elsif Convention (Entity (P)) = Convention_Intrinsic then
6703 if Ekind (Entity (P)) = E_Enumeration_Literal then
6705 ("prefix of % attribute cannot be enumeration literal",
6709 ("prefix of % attribute cannot be intrinsic", P);
6712 Set_Etype (N, Any_Type);
6714 elsif Is_Thread_Body (Entity (P)) then
6716 ("prefix of % attribute cannot be a thread body", P);
6719 -- Assignments, return statements, components of aggregates,
6720 -- generic instantiations will require convention checks if
6721 -- the type is an access to subprogram. Given that there will
6722 -- also be accessibility checks on those, this is where the
6723 -- checks can eventually be centralized ???
6725 if Ekind (Btyp) = E_Access_Subprogram_Type
6727 Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type
6729 Ekind (Btyp) = E_Anonymous_Access_Protected_Subprogram_Type
6731 if Convention (Btyp) /= Convention (Entity (P)) then
6733 ("subprogram has invalid convention for context", P);
6736 Check_Subtype_Conformant
6737 (New_Id => Entity (P),
6738 Old_Id => Designated_Type (Btyp),
6742 if Attr_Id = Attribute_Unchecked_Access then
6743 Error_Msg_Name_1 := Aname;
6745 ("attribute% cannot be applied to a subprogram", P);
6747 elsif Aname = Name_Unrestricted_Access then
6748 null; -- Nothing to check
6750 -- Check the static accessibility rule of 3.10.2(32)
6751 -- In an instance body, if subprogram and type are both
6752 -- local, other rules prevent dangling references, and no
6753 -- warning is needed.
6755 elsif Attr_Id = Attribute_Access
6756 and then Subprogram_Access_Level (Entity (P)) >
6757 Type_Access_Level (Btyp)
6758 and then Ekind (Btyp) /=
6759 E_Anonymous_Access_Subprogram_Type
6760 and then Ekind (Btyp) /=
6761 E_Anonymous_Access_Protected_Subprogram_Type
6763 if not In_Instance_Body then
6765 ("subprogram must not be deeper than access type",
6768 elsif Scope (Entity (P)) /= Scope (Btyp) then
6770 ("subprogram must not be deeper than access type?",
6773 ("Constraint_Error will be raised ?", P);
6774 Set_Raises_Constraint_Error (N);
6777 -- Check the restriction of 3.10.2(32) that disallows
6778 -- the type of the access attribute to be declared
6779 -- outside a generic body when the subprogram is declared
6780 -- within that generic body.
6782 -- Ada2005: If the expected type is for an access
6783 -- parameter, this clause does not apply.
6785 elsif Present (Enclosing_Generic_Body (Entity (P)))
6786 and then Enclosing_Generic_Body (Entity (P)) /=
6787 Enclosing_Generic_Body (Btyp)
6789 Ekind (Btyp) /= E_Anonymous_Access_Subprogram_Type
6792 ("access type must not be outside generic body", P);
6796 -- If this is a renaming, an inherited operation, or a
6797 -- subprogram instance, use the original entity.
6799 if Is_Entity_Name (P)
6800 and then Is_Overloadable (Entity (P))
6801 and then Present (Alias (Entity (P)))
6804 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
6807 elsif Nkind (P) = N_Selected_Component
6808 and then Is_Overloadable (Entity (Selector_Name (P)))
6810 -- Protected operation. If operation is overloaded, must
6811 -- disambiguate. Prefix that denotes protected object itself
6812 -- is resolved with its own type.
6814 if Attr_Id = Attribute_Unchecked_Access then
6815 Error_Msg_Name_1 := Aname;
6817 ("attribute% cannot be applied to protected operation", P);
6820 Resolve (Prefix (P));
6821 Generate_Reference (Entity (Selector_Name (P)), P);
6823 elsif Is_Overloaded (P) then
6825 -- Use the designated type of the context to disambiguate
6826 -- Note that this was not strictly conformant to Ada 95,
6827 -- but was the implementation adopted by most Ada 95 compilers.
6828 -- The use of the context type to resolve an Access attribute
6829 -- reference is now mandated in AI-235 for Ada 2005.
6832 Index : Interp_Index;
6836 Get_First_Interp (P, Index, It);
6837 while Present (It.Typ) loop
6838 if Covers (Designated_Type (Typ), It.Typ) then
6839 Resolve (P, It.Typ);
6843 Get_Next_Interp (Index, It);
6850 -- X'Access is illegal if X denotes a constant and the access
6851 -- type is access-to-variable. Same for 'Unchecked_Access.
6852 -- The rule does not apply to 'Unrestricted_Access.
6854 if not (Ekind (Btyp) = E_Access_Subprogram_Type
6855 or else Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type
6856 or else (Is_Record_Type (Btyp) and then
6857 Present (Corresponding_Remote_Type (Btyp)))
6858 or else Ekind (Btyp) = E_Access_Protected_Subprogram_Type
6859 or else Ekind (Btyp)
6860 = E_Anonymous_Access_Protected_Subprogram_Type
6861 or else Is_Access_Constant (Btyp)
6862 or else Is_Variable (P)
6863 or else Attr_Id = Attribute_Unrestricted_Access)
6865 if Comes_From_Source (N) then
6866 Error_Msg_N ("access-to-variable designates constant", P);
6870 if (Attr_Id = Attribute_Access
6872 Attr_Id = Attribute_Unchecked_Access)
6873 and then (Ekind (Btyp) = E_General_Access_Type
6874 or else Ekind (Btyp) = E_Anonymous_Access_Type)
6876 -- Ada 2005 (AI-230): Check the accessibility of anonymous
6877 -- access types in record and array components. For a
6878 -- component definition the level is the same of the
6879 -- enclosing composite type.
6881 if Ada_Version >= Ada_05
6882 and then Ekind (Btyp) = E_Anonymous_Access_Type
6883 and then (Is_Array_Type (Scope (Btyp))
6884 or else Ekind (Scope (Btyp)) = E_Record_Type)
6885 and then Object_Access_Level (P) > Type_Access_Level (Btyp)
6887 -- In an instance, this is a runtime check, but one we
6888 -- know will fail, so generate an appropriate warning.
6890 if In_Instance_Body then
6892 ("?non-local pointer cannot point to local object", P);
6894 ("?Program_Error will be raised at run time", P);
6896 Make_Raise_Program_Error (Loc,
6897 Reason => PE_Accessibility_Check_Failed));
6901 ("non-local pointer cannot point to local object", P);
6905 if Is_Dependent_Component_Of_Mutable_Object (P) then
6907 ("illegal attribute for discriminant-dependent component",
6911 -- Check the static matching rule of 3.10.2(27). The
6912 -- nominal subtype of the prefix must statically
6913 -- match the designated type.
6915 Nom_Subt := Etype (P);
6917 if Is_Constr_Subt_For_U_Nominal (Nom_Subt) then
6918 Nom_Subt := Etype (Nom_Subt);
6921 if Is_Tagged_Type (Designated_Type (Typ)) then
6923 -- If the attribute is in the context of an access
6924 -- parameter, then the prefix is allowed to be of
6925 -- the class-wide type (by AI-127).
6927 if Ekind (Typ) = E_Anonymous_Access_Type then
6928 if not Covers (Designated_Type (Typ), Nom_Subt)
6929 and then not Covers (Nom_Subt, Designated_Type (Typ))
6935 Desig := Designated_Type (Typ);
6937 if Is_Class_Wide_Type (Desig) then
6938 Desig := Etype (Desig);
6941 if Is_Anonymous_Tagged_Base (Nom_Subt, Desig) then
6946 ("type of prefix: & not compatible",
6949 ("\with &, the expected designated type",
6950 P, Designated_Type (Typ));
6955 elsif not Covers (Designated_Type (Typ), Nom_Subt)
6957 (not Is_Class_Wide_Type (Designated_Type (Typ))
6958 and then Is_Class_Wide_Type (Nom_Subt))
6961 ("type of prefix: & is not covered", P, Nom_Subt);
6963 ("\by &, the expected designated type" &
6964 " ('R'M 3.10.2 (27))", P, Designated_Type (Typ));
6967 if Is_Class_Wide_Type (Designated_Type (Typ))
6968 and then Has_Discriminants (Etype (Designated_Type (Typ)))
6969 and then Is_Constrained (Etype (Designated_Type (Typ)))
6970 and then Designated_Type (Typ) /= Nom_Subt
6972 Apply_Discriminant_Check
6973 (N, Etype (Designated_Type (Typ)));
6976 elsif not Subtypes_Statically_Match
6977 (Designated_Type (Base_Type (Typ)), Nom_Subt)
6979 not (Has_Discriminants (Designated_Type (Typ))
6982 (Designated_Type (Base_Type (Typ))))
6985 ("object subtype must statically match "
6986 & "designated subtype", P);
6988 if Is_Entity_Name (P)
6989 and then Is_Array_Type (Designated_Type (Typ))
6993 D : constant Node_Id := Declaration_Node (Entity (P));
6996 Error_Msg_N ("aliased object has explicit bounds?",
6998 Error_Msg_N ("\declare without bounds"
6999 & " (and with explicit initialization)?", D);
7000 Error_Msg_N ("\for use with unconstrained access?", D);
7005 -- Check the static accessibility rule of 3.10.2(28).
7006 -- Note that this check is not performed for the
7007 -- case of an anonymous access type, since the access
7008 -- attribute is always legal in such a context.
7010 if Attr_Id /= Attribute_Unchecked_Access
7011 and then Object_Access_Level (P) > Type_Access_Level (Btyp)
7012 and then Ekind (Btyp) = E_General_Access_Type
7014 Accessibility_Message;
7019 if Ekind (Btyp) = E_Access_Protected_Subprogram_Type
7021 Ekind (Btyp) = E_Anonymous_Access_Protected_Subprogram_Type
7023 if Is_Entity_Name (P)
7024 and then not Is_Protected_Type (Scope (Entity (P)))
7026 Error_Msg_N ("context requires a protected subprogram", P);
7028 -- Check accessibility of protected object against that
7029 -- of the access type, but only on user code, because
7030 -- the expander creates access references for handlers.
7031 -- If the context is an anonymous_access_to_protected,
7032 -- there are no accessibility checks either.
7034 elsif Object_Access_Level (P) > Type_Access_Level (Btyp)
7035 and then Comes_From_Source (N)
7036 and then Ekind (Btyp) = E_Access_Protected_Subprogram_Type
7037 and then No (Original_Access_Type (Typ))
7039 Accessibility_Message;
7043 elsif (Ekind (Btyp) = E_Access_Subprogram_Type
7045 Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type)
7046 and then Ekind (Etype (N)) = E_Access_Protected_Subprogram_Type
7048 Error_Msg_N ("context requires a non-protected subprogram", P);
7051 -- The context cannot be a pool-specific type, but this is a
7052 -- legality rule, not a resolution rule, so it must be checked
7053 -- separately, after possibly disambiguation (see AI-245).
7055 if Ekind (Btyp) = E_Access_Type
7056 and then Attr_Id /= Attribute_Unrestricted_Access
7058 Wrong_Type (N, Typ);
7063 -- Check for incorrect atomic/volatile reference (RM C.6(12))
7065 if Attr_Id /= Attribute_Unrestricted_Access then
7066 if Is_Atomic_Object (P)
7067 and then not Is_Atomic (Designated_Type (Typ))
7070 ("access to atomic object cannot yield access-to-" &
7071 "non-atomic type", P);
7073 elsif Is_Volatile_Object (P)
7074 and then not Is_Volatile (Designated_Type (Typ))
7077 ("access to volatile object cannot yield access-to-" &
7078 "non-volatile type", P);
7086 -- Deal with resolving the type for Address attribute, overloading
7087 -- is not permitted here, since there is no context to resolve it.
7089 when Attribute_Address | Attribute_Code_Address =>
7091 -- To be safe, assume that if the address of a variable is taken,
7092 -- it may be modified via this address, so note modification.
7094 if Is_Variable (P) then
7095 Note_Possible_Modification (P);
7098 if Nkind (P) in N_Subexpr
7099 and then Is_Overloaded (P)
7101 Get_First_Interp (P, Index, It);
7102 Get_Next_Interp (Index, It);
7104 if Present (It.Nam) then
7105 Error_Msg_Name_1 := Aname;
7107 ("prefix of % attribute cannot be overloaded", N);
7112 if not Is_Entity_Name (P)
7113 or else not Is_Overloadable (Entity (P))
7115 if not Is_Task_Type (Etype (P))
7116 or else Nkind (P) = N_Explicit_Dereference
7122 -- If this is the name of a derived subprogram, or that of a
7123 -- generic actual, the address is that of the original entity.
7125 if Is_Entity_Name (P)
7126 and then Is_Overloadable (Entity (P))
7127 and then Present (Alias (Entity (P)))
7130 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
7137 -- Prefix of the AST_Entry attribute is an entry name which must
7138 -- not be resolved, since this is definitely not an entry call.
7140 when Attribute_AST_Entry =>
7147 -- Prefix of Body_Version attribute can be a subprogram name which
7148 -- must not be resolved, since this is not a call.
7150 when Attribute_Body_Version =>
7157 -- Prefix of Caller attribute is an entry name which must not
7158 -- be resolved, since this is definitely not an entry call.
7160 when Attribute_Caller =>
7167 -- Shares processing with Address attribute
7173 -- If the prefix of the Count attribute is an entry name it must not
7174 -- be resolved, since this is definitely not an entry call. However,
7175 -- if it is an element of an entry family, the index itself may
7176 -- have to be resolved because it can be a general expression.
7178 when Attribute_Count =>
7179 if Nkind (P) = N_Indexed_Component
7180 and then Is_Entity_Name (Prefix (P))
7183 Indx : constant Node_Id := First (Expressions (P));
7184 Fam : constant Entity_Id := Entity (Prefix (P));
7186 Resolve (Indx, Entry_Index_Type (Fam));
7187 Apply_Range_Check (Indx, Entry_Index_Type (Fam));
7195 -- Prefix of the Elaborated attribute is a subprogram name which
7196 -- must not be resolved, since this is definitely not a call. Note
7197 -- that it is a library unit, so it cannot be overloaded here.
7199 when Attribute_Elaborated =>
7202 --------------------
7203 -- Mechanism_Code --
7204 --------------------
7206 -- Prefix of the Mechanism_Code attribute is a function name
7207 -- which must not be resolved. Should we check for overloaded ???
7209 when Attribute_Mechanism_Code =>
7216 -- Most processing is done in sem_dist, after determining the
7217 -- context type. Node is rewritten as a conversion to a runtime call.
7219 when Attribute_Partition_ID =>
7220 Process_Partition_Id (N);
7223 when Attribute_Pool_Address =>
7230 -- We replace the Range attribute node with a range expression
7231 -- whose bounds are the 'First and 'Last attributes applied to the
7232 -- same prefix. The reason that we do this transformation here
7233 -- instead of in the expander is that it simplifies other parts of
7234 -- the semantic analysis which assume that the Range has been
7235 -- replaced; thus it must be done even when in semantic-only mode
7236 -- (note that the RM specifically mentions this equivalence, we
7237 -- take care that the prefix is only evaluated once).
7239 when Attribute_Range => Range_Attribute :
7244 function Check_Discriminated_Prival
7247 -- The range of a private component constrained by a
7248 -- discriminant is rewritten to make the discriminant
7249 -- explicit. This solves some complex visibility problems
7250 -- related to the use of privals.
7252 --------------------------------
7253 -- Check_Discriminated_Prival --
7254 --------------------------------
7256 function Check_Discriminated_Prival
7261 if Is_Entity_Name (N)
7262 and then Ekind (Entity (N)) = E_In_Parameter
7263 and then not Within_Init_Proc
7265 return Make_Identifier (Sloc (N), Chars (Entity (N)));
7267 return Duplicate_Subexpr (N);
7269 end Check_Discriminated_Prival;
7271 -- Start of processing for Range_Attribute
7274 if not Is_Entity_Name (P)
7275 or else not Is_Type (Entity (P))
7280 -- Check whether prefix is (renaming of) private component
7281 -- of protected type.
7283 if Is_Entity_Name (P)
7284 and then Comes_From_Source (N)
7285 and then Is_Array_Type (Etype (P))
7286 and then Number_Dimensions (Etype (P)) = 1
7287 and then (Ekind (Scope (Entity (P))) = E_Protected_Type
7289 Ekind (Scope (Scope (Entity (P)))) =
7293 Check_Discriminated_Prival
7294 (Type_Low_Bound (Etype (First_Index (Etype (P)))));
7297 Check_Discriminated_Prival
7298 (Type_High_Bound (Etype (First_Index (Etype (P)))));
7302 Make_Attribute_Reference (Loc,
7303 Prefix => Duplicate_Subexpr (P),
7304 Attribute_Name => Name_Last,
7305 Expressions => Expressions (N));
7308 Make_Attribute_Reference (Loc,
7310 Attribute_Name => Name_First,
7311 Expressions => Expressions (N));
7314 -- If the original was marked as Must_Not_Freeze (see code
7315 -- in Sem_Ch3.Make_Index), then make sure the rewriting
7316 -- does not freeze either.
7318 if Must_Not_Freeze (N) then
7319 Set_Must_Not_Freeze (HB);
7320 Set_Must_Not_Freeze (LB);
7321 Set_Must_Not_Freeze (Prefix (HB));
7322 Set_Must_Not_Freeze (Prefix (LB));
7325 if Raises_Constraint_Error (Prefix (N)) then
7327 -- Preserve Sloc of prefix in the new bounds, so that
7328 -- the posted warning can be removed if we are within
7329 -- unreachable code.
7331 Set_Sloc (LB, Sloc (Prefix (N)));
7332 Set_Sloc (HB, Sloc (Prefix (N)));
7335 Rewrite (N, Make_Range (Loc, LB, HB));
7336 Analyze_And_Resolve (N, Typ);
7338 -- Normally after resolving attribute nodes, Eval_Attribute
7339 -- is called to do any possible static evaluation of the node.
7340 -- However, here since the Range attribute has just been
7341 -- transformed into a range expression it is no longer an
7342 -- attribute node and therefore the call needs to be avoided
7343 -- and is accomplished by simply returning from the procedure.
7346 end Range_Attribute;
7352 -- Prefix must not be resolved in this case, since it is not a
7353 -- real entity reference. No action of any kind is require!
7355 when Attribute_UET_Address =>
7358 ----------------------
7359 -- Unchecked_Access --
7360 ----------------------
7362 -- Processing is shared with Access
7364 -------------------------
7365 -- Unrestricted_Access --
7366 -------------------------
7368 -- Processing is shared with Access
7374 -- Apply range check. Note that we did not do this during the
7375 -- analysis phase, since we wanted Eval_Attribute to have a
7376 -- chance at finding an illegal out of range value.
7378 when Attribute_Val =>
7380 -- Note that we do our own Eval_Attribute call here rather than
7381 -- use the common one, because we need to do processing after
7382 -- the call, as per above comment.
7386 -- Eval_Attribute may replace the node with a raise CE, or
7387 -- fold it to a constant. Obviously we only apply a scalar
7388 -- range check if this did not happen!
7390 if Nkind (N) = N_Attribute_Reference
7391 and then Attribute_Name (N) = Name_Val
7393 Apply_Scalar_Range_Check (First (Expressions (N)), Btyp);
7402 -- Prefix of Version attribute can be a subprogram name which
7403 -- must not be resolved, since this is not a call.
7405 when Attribute_Version =>
7408 ----------------------
7409 -- Other Attributes --
7410 ----------------------
7412 -- For other attributes, resolve prefix unless it is a type. If
7413 -- the attribute reference itself is a type name ('Base and 'Class)
7414 -- then this is only legal within a task or protected record.
7417 if not Is_Entity_Name (P)
7418 or else not Is_Type (Entity (P))
7423 -- If the attribute reference itself is a type name ('Base,
7424 -- 'Class) then this is only legal within a task or protected
7425 -- record. What is this all about ???
7427 if Is_Entity_Name (N)
7428 and then Is_Type (Entity (N))
7430 if Is_Concurrent_Type (Entity (N))
7431 and then In_Open_Scopes (Entity (P))
7436 ("invalid use of subtype name in expression or call", N);
7440 -- For attributes whose argument may be a string, complete
7441 -- resolution of argument now. This avoids premature expansion
7442 -- (and the creation of transient scopes) before the attribute
7443 -- reference is resolved.
7446 when Attribute_Value =>
7447 Resolve (First (Expressions (N)), Standard_String);
7449 when Attribute_Wide_Value =>
7450 Resolve (First (Expressions (N)), Standard_Wide_String);
7452 when Attribute_Wide_Wide_Value =>
7453 Resolve (First (Expressions (N)), Standard_Wide_Wide_String);
7455 when others => null;
7459 -- Normally the Freezing is done by Resolve but sometimes the Prefix
7460 -- is not resolved, in which case the freezing must be done now.
7462 Freeze_Expression (P);
7464 -- Finally perform static evaluation on the attribute reference
7467 end Resolve_Attribute;