1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Ada.Characters.Latin_1; use Ada.Characters.Latin_1;
28 with Atree; use Atree;
29 with Casing; use Casing;
30 with Checks; use Checks;
31 with Einfo; use Einfo;
32 with Errout; use Errout;
34 with Exp_Dist; use Exp_Dist;
35 with Exp_Util; use Exp_Util;
36 with Expander; use Expander;
37 with Freeze; use Freeze;
38 with Gnatvsn; use Gnatvsn;
39 with Itypes; use Itypes;
41 with Lib.Xref; use Lib.Xref;
42 with Nlists; use Nlists;
43 with Nmake; use Nmake;
45 with Restrict; use Restrict;
46 with Rident; use Rident;
47 with Rtsfind; use Rtsfind;
48 with Sdefault; use Sdefault;
50 with Sem_Aux; use Sem_Aux;
51 with Sem_Cat; use Sem_Cat;
52 with Sem_Ch6; use Sem_Ch6;
53 with Sem_Ch8; use Sem_Ch8;
54 with Sem_Ch10; use Sem_Ch10;
55 with Sem_Dist; use Sem_Dist;
56 with Sem_Elim; use Sem_Elim;
57 with Sem_Eval; use Sem_Eval;
58 with Sem_Res; use Sem_Res;
59 with Sem_Type; use Sem_Type;
60 with Sem_Util; use Sem_Util;
61 with Stand; use Stand;
62 with Sinfo; use Sinfo;
63 with Sinput; use Sinput;
64 with Stringt; use Stringt;
66 with Stylesw; use Stylesw;
67 with Targparm; use Targparm;
68 with Ttypes; use Ttypes;
69 with Tbuild; use Tbuild;
70 with Uintp; use Uintp;
71 with Urealp; use Urealp;
73 package body Sem_Attr is
75 True_Value : constant Uint := Uint_1;
76 False_Value : constant Uint := Uint_0;
77 -- Synonyms to be used when these constants are used as Boolean values
79 Bad_Attribute : exception;
80 -- Exception raised if an error is detected during attribute processing,
81 -- used so that we can abandon the processing so we don't run into
82 -- trouble with cascaded errors.
84 -- The following array is the list of attributes defined in the Ada 83 RM
85 -- that are not included in Ada 95, but still get recognized in GNAT.
87 Attribute_83 : constant Attribute_Class_Array := Attribute_Class_Array'(
93 Attribute_Constrained |
100 Attribute_First_Bit |
106 Attribute_Leading_Part |
108 Attribute_Machine_Emax |
109 Attribute_Machine_Emin |
110 Attribute_Machine_Mantissa |
111 Attribute_Machine_Overflows |
112 Attribute_Machine_Radix |
113 Attribute_Machine_Rounds |
119 Attribute_Safe_Emax |
120 Attribute_Safe_Large |
121 Attribute_Safe_Small |
124 Attribute_Storage_Size |
126 Attribute_Terminated |
129 Attribute_Width => True,
132 -- The following array is the list of attributes defined in the Ada 2005
133 -- RM which are not defined in Ada 95. These are recognized in Ada 95 mode,
134 -- but in Ada 95 they are considered to be implementation defined.
136 Attribute_05 : constant Attribute_Class_Array := Attribute_Class_Array'(
137 Attribute_Machine_Rounding |
140 Attribute_Stream_Size |
141 Attribute_Wide_Wide_Width => True,
144 -- The following array contains all attributes that imply a modification
145 -- of their prefixes or result in an access value. Such prefixes can be
146 -- considered as lvalues.
148 Attribute_Name_Implies_Lvalue_Prefix : constant Attribute_Class_Array :=
149 Attribute_Class_Array'(
154 Attribute_Unchecked_Access |
155 Attribute_Unrestricted_Access => True,
158 -----------------------
159 -- Local_Subprograms --
160 -----------------------
162 procedure Eval_Attribute (N : Node_Id);
163 -- Performs compile time evaluation of attributes where possible, leaving
164 -- the Is_Static_Expression/Raises_Constraint_Error flags appropriately
165 -- set, and replacing the node with a literal node if the value can be
166 -- computed at compile time. All static attribute references are folded,
167 -- as well as a number of cases of non-static attributes that can always
168 -- be computed at compile time (e.g. floating-point model attributes that
169 -- are applied to non-static subtypes). Of course in such cases, the
170 -- Is_Static_Expression flag will not be set on the resulting literal.
171 -- Note that the only required action of this procedure is to catch the
172 -- static expression cases as described in the RM. Folding of other cases
173 -- is done where convenient, but some additional non-static folding is in
174 -- N_Expand_Attribute_Reference in cases where this is more convenient.
176 function Is_Anonymous_Tagged_Base
180 -- For derived tagged types that constrain parent discriminants we build
181 -- an anonymous unconstrained base type. We need to recognize the relation
182 -- between the two when analyzing an access attribute for a constrained
183 -- component, before the full declaration for Typ has been analyzed, and
184 -- where therefore the prefix of the attribute does not match the enclosing
187 -----------------------
188 -- Analyze_Attribute --
189 -----------------------
191 procedure Analyze_Attribute (N : Node_Id) is
192 Loc : constant Source_Ptr := Sloc (N);
193 Aname : constant Name_Id := Attribute_Name (N);
194 P : constant Node_Id := Prefix (N);
195 Exprs : constant List_Id := Expressions (N);
196 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
201 -- Type of prefix after analysis
203 P_Base_Type : Entity_Id;
204 -- Base type of prefix after analysis
206 -----------------------
207 -- Local Subprograms --
208 -----------------------
210 procedure Analyze_Access_Attribute;
211 -- Used for Access, Unchecked_Access, Unrestricted_Access attributes.
212 -- Internally, Id distinguishes which of the three cases is involved.
214 procedure Bad_Attribute_For_Predicate;
215 -- Output error message for use of a predicate (First, Last, Range) not
216 -- allowed with a type that has predicates. If the type is a generic
217 -- actual, then the message is a warning, and we generate code to raise
218 -- program error with an appropriate reason. No error message is given
219 -- for internally generated uses of the attributes.
221 procedure Check_Array_Or_Scalar_Type;
222 -- Common procedure used by First, Last, Range attribute to check
223 -- that the prefix is a constrained array or scalar type, or a name
224 -- of an array object, and that an argument appears only if appropriate
225 -- (i.e. only in the array case).
227 procedure Check_Array_Type;
228 -- Common semantic checks for all array attributes. Checks that the
229 -- prefix is a constrained array type or the name of an array object.
230 -- The error message for non-arrays is specialized appropriately.
232 procedure Check_Asm_Attribute;
233 -- Common semantic checks for Asm_Input and Asm_Output attributes
235 procedure Check_Component;
236 -- Common processing for Bit_Position, First_Bit, Last_Bit, and
237 -- Position. Checks prefix is an appropriate selected component.
239 procedure Check_Decimal_Fixed_Point_Type;
240 -- Check that prefix of attribute N is a decimal fixed-point type
242 procedure Check_Dereference;
243 -- If the prefix of attribute is an object of an access type, then
244 -- introduce an explicit dereference, and adjust P_Type accordingly.
246 procedure Check_Discrete_Type;
247 -- Verify that prefix of attribute N is a discrete type
250 -- Check that no attribute arguments are present
252 procedure Check_Either_E0_Or_E1;
253 -- Check that there are zero or one attribute arguments present
256 -- Check that exactly one attribute argument is present
259 -- Check that two attribute arguments are present
261 procedure Check_Enum_Image;
262 -- If the prefix type is an enumeration type, set all its literals
263 -- as referenced, since the image function could possibly end up
264 -- referencing any of the literals indirectly. Same for Enum_Val.
266 procedure Check_Fixed_Point_Type;
267 -- Verify that prefix of attribute N is a fixed type
269 procedure Check_Fixed_Point_Type_0;
270 -- Verify that prefix of attribute N is a fixed type and that
271 -- no attribute expressions are present
273 procedure Check_Floating_Point_Type;
274 -- Verify that prefix of attribute N is a float type
276 procedure Check_Floating_Point_Type_0;
277 -- Verify that prefix of attribute N is a float type and that
278 -- no attribute expressions are present
280 procedure Check_Floating_Point_Type_1;
281 -- Verify that prefix of attribute N is a float type and that
282 -- exactly one attribute expression is present
284 procedure Check_Floating_Point_Type_2;
285 -- Verify that prefix of attribute N is a float type and that
286 -- two attribute expressions are present
288 procedure Legal_Formal_Attribute;
289 -- Common processing for attributes Definite and Has_Discriminants.
290 -- Checks that prefix is generic indefinite formal type.
292 procedure Check_Integer_Type;
293 -- Verify that prefix of attribute N is an integer type
295 procedure Check_Library_Unit;
296 -- Verify that prefix of attribute N is a library unit
298 procedure Check_Modular_Integer_Type;
299 -- Verify that prefix of attribute N is a modular integer type
301 procedure Check_Not_CPP_Type;
302 -- Check that P (the prefix of the attribute) is not an CPP type
303 -- for which no Ada predefined primitive is available.
305 procedure Check_Not_Incomplete_Type;
306 -- Check that P (the prefix of the attribute) is not an incomplete
307 -- type or a private type for which no full view has been given.
309 procedure Check_Object_Reference (P : Node_Id);
310 -- Check that P (the prefix of the attribute) is an object reference
312 procedure Check_Program_Unit;
313 -- Verify that prefix of attribute N is a program unit
315 procedure Check_Real_Type;
316 -- Verify that prefix of attribute N is fixed or float type
318 procedure Check_Scalar_Type;
319 -- Verify that prefix of attribute N is a scalar type
321 procedure Check_Standard_Prefix;
322 -- Verify that prefix of attribute N is package Standard
324 procedure Check_Stream_Attribute (Nam : TSS_Name_Type);
325 -- Validity checking for stream attribute. Nam is the TSS name of the
326 -- corresponding possible defined attribute function (e.g. for the
327 -- Read attribute, Nam will be TSS_Stream_Read).
329 procedure Check_PolyORB_Attribute;
330 -- Validity checking for PolyORB/DSA attribute
332 procedure Check_Task_Prefix;
333 -- Verify that prefix of attribute N is a task or task type
335 procedure Check_Type;
336 -- Verify that the prefix of attribute N is a type
338 procedure Check_Unit_Name (Nod : Node_Id);
339 -- Check that Nod is of the form of a library unit name, i.e that
340 -- it is an identifier, or a selected component whose prefix is
341 -- itself of the form of a library unit name. Note that this is
342 -- quite different from Check_Program_Unit, since it only checks
343 -- the syntactic form of the name, not the semantic identity. This
344 -- is because it is used with attributes (Elab_Body, Elab_Spec, and
345 -- UET_Address) which can refer to non-visible unit.
347 procedure Error_Attr (Msg : String; Error_Node : Node_Id);
348 pragma No_Return (Error_Attr);
349 procedure Error_Attr;
350 pragma No_Return (Error_Attr);
351 -- Posts error using Error_Msg_N at given node, sets type of attribute
352 -- node to Any_Type, and then raises Bad_Attribute to avoid any further
353 -- semantic processing. The message typically contains a % insertion
354 -- character which is replaced by the attribute name. The call with
355 -- no arguments is used when the caller has already generated the
356 -- required error messages.
358 procedure Error_Attr_P (Msg : String);
359 pragma No_Return (Error_Attr);
360 -- Like Error_Attr, but error is posted at the start of the prefix
362 procedure Standard_Attribute (Val : Int);
363 -- Used to process attributes whose prefix is package Standard which
364 -- yield values of type Universal_Integer. The attribute reference
365 -- node is rewritten with an integer literal of the given value.
367 procedure Unexpected_Argument (En : Node_Id);
368 -- Signal unexpected attribute argument (En is the argument)
370 procedure Validate_Non_Static_Attribute_Function_Call;
371 -- Called when processing an attribute that is a function call to a
372 -- non-static function, i.e. an attribute function that either takes
373 -- non-scalar arguments or returns a non-scalar result. Verifies that
374 -- such a call does not appear in a preelaborable context.
376 ------------------------------
377 -- Analyze_Access_Attribute --
378 ------------------------------
380 procedure Analyze_Access_Attribute is
381 Acc_Type : Entity_Id;
386 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id;
387 -- Build an access-to-object type whose designated type is DT,
388 -- and whose Ekind is appropriate to the attribute type. The
389 -- type that is constructed is returned as the result.
391 procedure Build_Access_Subprogram_Type (P : Node_Id);
392 -- Build an access to subprogram whose designated type is the type of
393 -- the prefix. If prefix is overloaded, so is the node itself. The
394 -- result is stored in Acc_Type.
396 function OK_Self_Reference return Boolean;
397 -- An access reference whose prefix is a type can legally appear
398 -- within an aggregate, where it is obtained by expansion of
399 -- a defaulted aggregate. The enclosing aggregate that contains
400 -- the self-referenced is flagged so that the self-reference can
401 -- be expanded into a reference to the target object (see exp_aggr).
403 ------------------------------
404 -- Build_Access_Object_Type --
405 ------------------------------
407 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id is
408 Typ : constant Entity_Id :=
410 (E_Access_Attribute_Type, Current_Scope, Loc, 'A');
412 Set_Etype (Typ, Typ);
414 Set_Associated_Node_For_Itype (Typ, N);
415 Set_Directly_Designated_Type (Typ, DT);
417 end Build_Access_Object_Type;
419 ----------------------------------
420 -- Build_Access_Subprogram_Type --
421 ----------------------------------
423 procedure Build_Access_Subprogram_Type (P : Node_Id) is
424 Index : Interp_Index;
427 procedure Check_Local_Access (E : Entity_Id);
428 -- Deal with possible access to local subprogram. If we have such
429 -- an access, we set a flag to kill all tracked values on any call
430 -- because this access value may be passed around, and any called
431 -- code might use it to access a local procedure which clobbers a
432 -- tracked value. If the scope is a loop or block, indicate that
433 -- value tracking is disabled for the enclosing subprogram.
435 function Get_Kind (E : Entity_Id) return Entity_Kind;
436 -- Distinguish between access to regular/protected subprograms
438 ------------------------
439 -- Check_Local_Access --
440 ------------------------
442 procedure Check_Local_Access (E : Entity_Id) is
444 if not Is_Library_Level_Entity (E) then
445 Set_Suppress_Value_Tracking_On_Call (Current_Scope);
446 Set_Suppress_Value_Tracking_On_Call
447 (Nearest_Dynamic_Scope (Current_Scope));
449 end Check_Local_Access;
455 function Get_Kind (E : Entity_Id) return Entity_Kind is
457 if Convention (E) = Convention_Protected then
458 return E_Access_Protected_Subprogram_Type;
460 return E_Access_Subprogram_Type;
464 -- Start of processing for Build_Access_Subprogram_Type
467 -- In the case of an access to subprogram, use the name of the
468 -- subprogram itself as the designated type. Type-checking in
469 -- this case compares the signatures of the designated types.
471 -- Note: This fragment of the tree is temporarily malformed
472 -- because the correct tree requires an E_Subprogram_Type entity
473 -- as the designated type. In most cases this designated type is
474 -- later overridden by the semantics with the type imposed by the
475 -- context during the resolution phase. In the specific case of
476 -- the expression Address!(Prim'Unrestricted_Access), used to
477 -- initialize slots of dispatch tables, this work will be done by
478 -- the expander (see Exp_Aggr).
480 -- The reason to temporarily add this kind of node to the tree
481 -- instead of a proper E_Subprogram_Type itype, is the following:
482 -- in case of errors found in the source file we report better
483 -- error messages. For example, instead of generating the
486 -- "expected access to subprogram with profile
487 -- defined at line X"
489 -- we currently generate:
491 -- "expected access to function Z defined at line X"
493 Set_Etype (N, Any_Type);
495 if not Is_Overloaded (P) then
496 Check_Local_Access (Entity (P));
498 if not Is_Intrinsic_Subprogram (Entity (P)) then
499 Acc_Type := Create_Itype (Get_Kind (Entity (P)), N);
500 Set_Is_Public (Acc_Type, False);
501 Set_Etype (Acc_Type, Acc_Type);
502 Set_Convention (Acc_Type, Convention (Entity (P)));
503 Set_Directly_Designated_Type (Acc_Type, Entity (P));
504 Set_Etype (N, Acc_Type);
505 Freeze_Before (N, Acc_Type);
509 Get_First_Interp (P, Index, It);
510 while Present (It.Nam) loop
511 Check_Local_Access (It.Nam);
513 if not Is_Intrinsic_Subprogram (It.Nam) then
514 Acc_Type := Create_Itype (Get_Kind (It.Nam), N);
515 Set_Is_Public (Acc_Type, False);
516 Set_Etype (Acc_Type, Acc_Type);
517 Set_Convention (Acc_Type, Convention (It.Nam));
518 Set_Directly_Designated_Type (Acc_Type, It.Nam);
519 Add_One_Interp (N, Acc_Type, Acc_Type);
520 Freeze_Before (N, Acc_Type);
523 Get_Next_Interp (Index, It);
527 -- Cannot be applied to intrinsic. Looking at the tests above,
528 -- the only way Etype (N) can still be set to Any_Type is if
529 -- Is_Intrinsic_Subprogram was True for some referenced entity.
531 if Etype (N) = Any_Type then
532 Error_Attr_P ("prefix of % attribute cannot be intrinsic");
534 end Build_Access_Subprogram_Type;
536 ----------------------
537 -- OK_Self_Reference --
538 ----------------------
540 function OK_Self_Reference return Boolean is
547 (Nkind (Par) = N_Component_Association
548 or else Nkind (Par) in N_Subexpr)
550 if Nkind_In (Par, N_Aggregate, N_Extension_Aggregate) then
551 if Etype (Par) = Typ then
552 Set_Has_Self_Reference (Par);
560 -- No enclosing aggregate, or not a self-reference
563 end OK_Self_Reference;
565 -- Start of processing for Analyze_Access_Attribute
570 if Nkind (P) = N_Character_Literal then
572 ("prefix of % attribute cannot be enumeration literal");
575 -- Case of access to subprogram
577 if Is_Entity_Name (P)
578 and then Is_Overloadable (Entity (P))
580 if Has_Pragma_Inline_Always (Entity (P)) then
582 ("prefix of % attribute cannot be Inline_Always subprogram");
585 if Aname = Name_Unchecked_Access then
586 Error_Attr ("attribute% cannot be applied to a subprogram", P);
589 -- Issue an error if the prefix denotes an eliminated subprogram
591 Check_For_Eliminated_Subprogram (P, Entity (P));
593 -- Check for obsolescent subprogram reference
595 Check_Obsolescent_2005_Entity (Entity (P), P);
597 -- Build the appropriate subprogram type
599 Build_Access_Subprogram_Type (P);
601 -- For unrestricted access, kill current values, since this
602 -- attribute allows a reference to a local subprogram that
603 -- could modify local variables to be passed out of scope
605 if Aname = Name_Unrestricted_Access then
607 -- Do not kill values on nodes initializing dispatch tables
608 -- slots. The construct Prim_Ptr!(Prim'Unrestricted_Access)
609 -- is currently generated by the expander only for this
610 -- purpose. Done to keep the quality of warnings currently
611 -- generated by the compiler (otherwise any declaration of
612 -- a tagged type cleans constant indications from its scope).
614 if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
615 and then (Etype (Parent (N)) = RTE (RE_Prim_Ptr)
617 Etype (Parent (N)) = RTE (RE_Size_Ptr))
618 and then Is_Dispatching_Operation
619 (Directly_Designated_Type (Etype (N)))
629 -- Component is an operation of a protected type
631 elsif Nkind (P) = N_Selected_Component
632 and then Is_Overloadable (Entity (Selector_Name (P)))
634 if Ekind (Entity (Selector_Name (P))) = E_Entry then
635 Error_Attr_P ("prefix of % attribute must be subprogram");
638 Build_Access_Subprogram_Type (Selector_Name (P));
642 -- Deal with incorrect reference to a type, but note that some
643 -- accesses are allowed: references to the current type instance,
644 -- or in Ada 2005 self-referential pointer in a default-initialized
647 if Is_Entity_Name (P) then
650 -- The reference may appear in an aggregate that has been expanded
651 -- into a loop. Locate scope of type definition, if any.
653 Scop := Current_Scope;
654 while Ekind (Scop) = E_Loop loop
655 Scop := Scope (Scop);
658 if Is_Type (Typ) then
660 -- OK if we are within the scope of a limited type
661 -- let's mark the component as having per object constraint
663 if Is_Anonymous_Tagged_Base (Scop, Typ) then
671 Q : Node_Id := Parent (N);
675 and then Nkind (Q) /= N_Component_Declaration
681 Set_Has_Per_Object_Constraint
682 (Defining_Identifier (Q), True);
686 if Nkind (P) = N_Expanded_Name then
688 ("current instance prefix must be a direct name", P);
691 -- If a current instance attribute appears in a component
692 -- constraint it must appear alone; other contexts (spec-
693 -- expressions, within a task body) are not subject to this
696 if not In_Spec_Expression
697 and then not Has_Completion (Scop)
699 Nkind_In (Parent (N), N_Discriminant_Association,
700 N_Index_Or_Discriminant_Constraint)
703 ("current instance attribute must appear alone", N);
706 if Is_CPP_Class (Root_Type (Typ)) then
708 ("?current instance unsupported for derivations of "
709 & "'C'P'P types", N);
712 -- OK if we are in initialization procedure for the type
713 -- in question, in which case the reference to the type
714 -- is rewritten as a reference to the current object.
716 elsif Ekind (Scop) = E_Procedure
717 and then Is_Init_Proc (Scop)
718 and then Etype (First_Formal (Scop)) = Typ
721 Make_Attribute_Reference (Loc,
722 Prefix => Make_Identifier (Loc, Name_uInit),
723 Attribute_Name => Name_Unrestricted_Access));
727 -- OK if a task type, this test needs sharpening up ???
729 elsif Is_Task_Type (Typ) then
732 -- OK if self-reference in an aggregate in Ada 2005, and
733 -- the reference comes from a copied default expression.
735 -- Note that we check legality of self-reference even if the
736 -- expression comes from source, e.g. when a single component
737 -- association in an aggregate has a box association.
739 elsif Ada_Version >= Ada_2005
740 and then OK_Self_Reference
744 -- OK if reference to current instance of a protected object
746 elsif Is_Protected_Self_Reference (P) then
749 -- Otherwise we have an error case
752 Error_Attr ("% attribute cannot be applied to type", P);
758 -- If we fall through, we have a normal access to object case.
759 -- Unrestricted_Access is legal wherever an allocator would be
760 -- legal, so its Etype is set to E_Allocator. The expected type
761 -- of the other attributes is a general access type, and therefore
762 -- we label them with E_Access_Attribute_Type.
764 if not Is_Overloaded (P) then
765 Acc_Type := Build_Access_Object_Type (P_Type);
766 Set_Etype (N, Acc_Type);
769 Index : Interp_Index;
772 Set_Etype (N, Any_Type);
773 Get_First_Interp (P, Index, It);
774 while Present (It.Typ) loop
775 Acc_Type := Build_Access_Object_Type (It.Typ);
776 Add_One_Interp (N, Acc_Type, Acc_Type);
777 Get_Next_Interp (Index, It);
782 -- Special cases when we can find a prefix that is an entity name
791 if Is_Entity_Name (PP) then
794 -- If we have an access to an object, and the attribute
795 -- comes from source, then set the object as potentially
796 -- source modified. We do this because the resulting access
797 -- pointer can be used to modify the variable, and we might
798 -- not detect this, leading to some junk warnings.
800 Set_Never_Set_In_Source (Ent, False);
802 -- Mark entity as address taken, and kill current values
804 Set_Address_Taken (Ent);
805 Kill_Current_Values (Ent);
808 elsif Nkind_In (PP, N_Selected_Component,
819 -- Check for aliased view unless unrestricted case. We allow a
820 -- nonaliased prefix when within an instance because the prefix may
821 -- have been a tagged formal object, which is defined to be aliased
822 -- even when the actual might not be (other instance cases will have
823 -- been caught in the generic). Similarly, within an inlined body we
824 -- know that the attribute is legal in the original subprogram, and
825 -- therefore legal in the expansion.
827 if Aname /= Name_Unrestricted_Access
828 and then not Is_Aliased_View (P)
829 and then not In_Instance
830 and then not In_Inlined_Body
832 Error_Attr_P ("prefix of % attribute must be aliased");
834 end Analyze_Access_Attribute;
836 ---------------------------------
837 -- Bad_Attribute_For_Predicate --
838 ---------------------------------
840 procedure Bad_Attribute_For_Predicate is
842 if Comes_From_Source (N) then
843 Error_Msg_Name_1 := Aname;
844 Bad_Predicated_Subtype_Use
845 ("type& has predicates, attribute % not allowed", N, P_Type);
847 end Bad_Attribute_For_Predicate;
849 --------------------------------
850 -- Check_Array_Or_Scalar_Type --
851 --------------------------------
853 procedure Check_Array_Or_Scalar_Type is
857 -- Dimension number for array attributes
860 -- Case of string literal or string literal subtype. These cases
861 -- cannot arise from legal Ada code, but the expander is allowed
862 -- to generate them. They require special handling because string
863 -- literal subtypes do not have standard bounds (the whole idea
864 -- of these subtypes is to avoid having to generate the bounds)
866 if Ekind (P_Type) = E_String_Literal_Subtype then
867 Set_Etype (N, Etype (First_Index (P_Base_Type)));
872 elsif Is_Scalar_Type (P_Type) then
876 Error_Attr ("invalid argument in % attribute", E1);
878 Set_Etype (N, P_Base_Type);
882 -- The following is a special test to allow 'First to apply to
883 -- private scalar types if the attribute comes from generated
884 -- code. This occurs in the case of Normalize_Scalars code.
886 elsif Is_Private_Type (P_Type)
887 and then Present (Full_View (P_Type))
888 and then Is_Scalar_Type (Full_View (P_Type))
889 and then not Comes_From_Source (N)
891 Set_Etype (N, Implementation_Base_Type (P_Type));
893 -- Array types other than string literal subtypes handled above
898 -- We know prefix is an array type, or the name of an array
899 -- object, and that the expression, if present, is static
900 -- and within the range of the dimensions of the type.
902 pragma Assert (Is_Array_Type (P_Type));
903 Index := First_Index (P_Base_Type);
907 -- First dimension assumed
909 Set_Etype (N, Base_Type (Etype (Index)));
912 D := UI_To_Int (Intval (E1));
914 for J in 1 .. D - 1 loop
918 Set_Etype (N, Base_Type (Etype (Index)));
919 Set_Etype (E1, Standard_Integer);
922 end Check_Array_Or_Scalar_Type;
924 ----------------------
925 -- Check_Array_Type --
926 ----------------------
928 procedure Check_Array_Type is
930 -- Dimension number for array attributes
933 -- If the type is a string literal type, then this must be generated
934 -- internally, and no further check is required on its legality.
936 if Ekind (P_Type) = E_String_Literal_Subtype then
939 -- If the type is a composite, it is an illegal aggregate, no point
942 elsif P_Type = Any_Composite then
946 -- Normal case of array type or subtype
948 Check_Either_E0_Or_E1;
951 if Is_Array_Type (P_Type) then
952 if not Is_Constrained (P_Type)
953 and then Is_Entity_Name (P)
954 and then Is_Type (Entity (P))
956 -- Note: we do not call Error_Attr here, since we prefer to
957 -- continue, using the relevant index type of the array,
958 -- even though it is unconstrained. This gives better error
959 -- recovery behavior.
961 Error_Msg_Name_1 := Aname;
963 ("prefix for % attribute must be constrained array", P);
966 D := Number_Dimensions (P_Type);
969 if Is_Private_Type (P_Type) then
970 Error_Attr_P ("prefix for % attribute may not be private type");
972 elsif Is_Access_Type (P_Type)
973 and then Is_Array_Type (Designated_Type (P_Type))
974 and then Is_Entity_Name (P)
975 and then Is_Type (Entity (P))
977 Error_Attr_P ("prefix of % attribute cannot be access type");
979 elsif Attr_Id = Attribute_First
981 Attr_Id = Attribute_Last
983 Error_Attr ("invalid prefix for % attribute", P);
986 Error_Attr_P ("prefix for % attribute must be array");
991 Resolve (E1, Any_Integer);
992 Set_Etype (E1, Standard_Integer);
994 if not Is_Static_Expression (E1)
995 or else Raises_Constraint_Error (E1)
998 ("expression for dimension must be static!", E1);
1001 elsif UI_To_Int (Expr_Value (E1)) > D
1002 or else UI_To_Int (Expr_Value (E1)) < 1
1004 Error_Attr ("invalid dimension number for array type", E1);
1008 if (Style_Check and Style_Check_Array_Attribute_Index)
1009 and then Comes_From_Source (N)
1011 Style.Check_Array_Attribute_Index (N, E1, D);
1013 end Check_Array_Type;
1015 -------------------------
1016 -- Check_Asm_Attribute --
1017 -------------------------
1019 procedure Check_Asm_Attribute is
1024 -- Check first argument is static string expression
1026 Analyze_And_Resolve (E1, Standard_String);
1028 if Etype (E1) = Any_Type then
1031 elsif not Is_OK_Static_Expression (E1) then
1032 Flag_Non_Static_Expr
1033 ("constraint argument must be static string expression!", E1);
1037 -- Check second argument is right type
1039 Analyze_And_Resolve (E2, Entity (P));
1041 -- Note: that is all we need to do, we don't need to check
1042 -- that it appears in a correct context. The Ada type system
1043 -- will do that for us.
1045 end Check_Asm_Attribute;
1047 ---------------------
1048 -- Check_Component --
1049 ---------------------
1051 procedure Check_Component is
1055 if Nkind (P) /= N_Selected_Component
1057 (Ekind (Entity (Selector_Name (P))) /= E_Component
1059 Ekind (Entity (Selector_Name (P))) /= E_Discriminant)
1061 Error_Attr_P ("prefix for % attribute must be selected component");
1063 end Check_Component;
1065 ------------------------------------
1066 -- Check_Decimal_Fixed_Point_Type --
1067 ------------------------------------
1069 procedure Check_Decimal_Fixed_Point_Type is
1073 if not Is_Decimal_Fixed_Point_Type (P_Type) then
1074 Error_Attr_P ("prefix of % attribute must be decimal type");
1076 end Check_Decimal_Fixed_Point_Type;
1078 -----------------------
1079 -- Check_Dereference --
1080 -----------------------
1082 procedure Check_Dereference is
1085 -- Case of a subtype mark
1087 if Is_Entity_Name (P)
1088 and then Is_Type (Entity (P))
1093 -- Case of an expression
1097 if Is_Access_Type (P_Type) then
1099 -- If there is an implicit dereference, then we must freeze
1100 -- the designated type of the access type, since the type of
1101 -- the referenced array is this type (see AI95-00106).
1103 -- As done elsewhere, freezing must not happen when pre-analyzing
1104 -- a pre- or postcondition or a default value for an object or
1105 -- for a formal parameter.
1107 if not In_Spec_Expression then
1108 Freeze_Before (N, Designated_Type (P_Type));
1112 Make_Explicit_Dereference (Sloc (P),
1113 Prefix => Relocate_Node (P)));
1115 Analyze_And_Resolve (P);
1116 P_Type := Etype (P);
1118 if P_Type = Any_Type then
1119 raise Bad_Attribute;
1122 P_Base_Type := Base_Type (P_Type);
1124 end Check_Dereference;
1126 -------------------------
1127 -- Check_Discrete_Type --
1128 -------------------------
1130 procedure Check_Discrete_Type is
1134 if not Is_Discrete_Type (P_Type) then
1135 Error_Attr_P ("prefix of % attribute must be discrete type");
1137 end Check_Discrete_Type;
1143 procedure Check_E0 is
1145 if Present (E1) then
1146 Unexpected_Argument (E1);
1154 procedure Check_E1 is
1156 Check_Either_E0_Or_E1;
1160 -- Special-case attributes that are functions and that appear as
1161 -- the prefix of another attribute. Error is posted on parent.
1163 if Nkind (Parent (N)) = N_Attribute_Reference
1164 and then (Attribute_Name (Parent (N)) = Name_Address
1166 Attribute_Name (Parent (N)) = Name_Code_Address
1168 Attribute_Name (Parent (N)) = Name_Access)
1170 Error_Msg_Name_1 := Attribute_Name (Parent (N));
1171 Error_Msg_N ("illegal prefix for % attribute", Parent (N));
1172 Set_Etype (Parent (N), Any_Type);
1173 Set_Entity (Parent (N), Any_Type);
1174 raise Bad_Attribute;
1177 Error_Attr ("missing argument for % attribute", N);
1186 procedure Check_E2 is
1189 Error_Attr ("missing arguments for % attribute (2 required)", N);
1191 Error_Attr ("missing argument for % attribute (2 required)", N);
1195 ---------------------------
1196 -- Check_Either_E0_Or_E1 --
1197 ---------------------------
1199 procedure Check_Either_E0_Or_E1 is
1201 if Present (E2) then
1202 Unexpected_Argument (E2);
1204 end Check_Either_E0_Or_E1;
1206 ----------------------
1207 -- Check_Enum_Image --
1208 ----------------------
1210 procedure Check_Enum_Image is
1213 if Is_Enumeration_Type (P_Base_Type) then
1214 Lit := First_Literal (P_Base_Type);
1215 while Present (Lit) loop
1216 Set_Referenced (Lit);
1220 end Check_Enum_Image;
1222 ----------------------------
1223 -- Check_Fixed_Point_Type --
1224 ----------------------------
1226 procedure Check_Fixed_Point_Type is
1230 if not Is_Fixed_Point_Type (P_Type) then
1231 Error_Attr_P ("prefix of % attribute must be fixed point type");
1233 end Check_Fixed_Point_Type;
1235 ------------------------------
1236 -- Check_Fixed_Point_Type_0 --
1237 ------------------------------
1239 procedure Check_Fixed_Point_Type_0 is
1241 Check_Fixed_Point_Type;
1243 end Check_Fixed_Point_Type_0;
1245 -------------------------------
1246 -- Check_Floating_Point_Type --
1247 -------------------------------
1249 procedure Check_Floating_Point_Type is
1253 if not Is_Floating_Point_Type (P_Type) then
1254 Error_Attr_P ("prefix of % attribute must be float type");
1256 end Check_Floating_Point_Type;
1258 ---------------------------------
1259 -- Check_Floating_Point_Type_0 --
1260 ---------------------------------
1262 procedure Check_Floating_Point_Type_0 is
1264 Check_Floating_Point_Type;
1266 end Check_Floating_Point_Type_0;
1268 ---------------------------------
1269 -- Check_Floating_Point_Type_1 --
1270 ---------------------------------
1272 procedure Check_Floating_Point_Type_1 is
1274 Check_Floating_Point_Type;
1276 end Check_Floating_Point_Type_1;
1278 ---------------------------------
1279 -- Check_Floating_Point_Type_2 --
1280 ---------------------------------
1282 procedure Check_Floating_Point_Type_2 is
1284 Check_Floating_Point_Type;
1286 end Check_Floating_Point_Type_2;
1288 ------------------------
1289 -- Check_Integer_Type --
1290 ------------------------
1292 procedure Check_Integer_Type is
1296 if not Is_Integer_Type (P_Type) then
1297 Error_Attr_P ("prefix of % attribute must be integer type");
1299 end Check_Integer_Type;
1301 ------------------------
1302 -- Check_Library_Unit --
1303 ------------------------
1305 procedure Check_Library_Unit is
1307 if not Is_Compilation_Unit (Entity (P)) then
1308 Error_Attr_P ("prefix of % attribute must be library unit");
1310 end Check_Library_Unit;
1312 --------------------------------
1313 -- Check_Modular_Integer_Type --
1314 --------------------------------
1316 procedure Check_Modular_Integer_Type is
1320 if not Is_Modular_Integer_Type (P_Type) then
1322 ("prefix of % attribute must be modular integer type");
1324 end Check_Modular_Integer_Type;
1326 ------------------------
1327 -- Check_Not_CPP_Type --
1328 ------------------------
1330 procedure Check_Not_CPP_Type is
1332 if Is_Tagged_Type (Etype (P))
1333 and then Convention (Etype (P)) = Convention_CPP
1334 and then Is_CPP_Class (Root_Type (Etype (P)))
1337 ("invalid use of % attribute with 'C'P'P tagged type");
1339 end Check_Not_CPP_Type;
1341 -------------------------------
1342 -- Check_Not_Incomplete_Type --
1343 -------------------------------
1345 procedure Check_Not_Incomplete_Type is
1350 -- Ada 2005 (AI-50217, AI-326): If the prefix is an explicit
1351 -- dereference we have to check wrong uses of incomplete types
1352 -- (other wrong uses are checked at their freezing point).
1354 -- Example 1: Limited-with
1356 -- limited with Pkg;
1358 -- type Acc is access Pkg.T;
1360 -- S : Integer := X.all'Size; -- ERROR
1363 -- Example 2: Tagged incomplete
1365 -- type T is tagged;
1366 -- type Acc is access all T;
1368 -- S : constant Integer := X.all'Size; -- ERROR
1369 -- procedure Q (Obj : Integer := X.all'Alignment); -- ERROR
1371 if Ada_Version >= Ada_2005
1372 and then Nkind (P) = N_Explicit_Dereference
1375 while Nkind (E) = N_Explicit_Dereference loop
1381 if From_With_Type (Typ) then
1383 ("prefix of % attribute cannot be an incomplete type");
1386 if Is_Access_Type (Typ) then
1387 Typ := Directly_Designated_Type (Typ);
1390 if Is_Class_Wide_Type (Typ) then
1391 Typ := Root_Type (Typ);
1394 -- A legal use of a shadow entity occurs only when the unit
1395 -- where the non-limited view resides is imported via a regular
1396 -- with clause in the current body. Such references to shadow
1397 -- entities may occur in subprogram formals.
1399 if Is_Incomplete_Type (Typ)
1400 and then From_With_Type (Typ)
1401 and then Present (Non_Limited_View (Typ))
1402 and then Is_Legal_Shadow_Entity_In_Body (Typ)
1404 Typ := Non_Limited_View (Typ);
1407 if Ekind (Typ) = E_Incomplete_Type
1408 and then No (Full_View (Typ))
1411 ("prefix of % attribute cannot be an incomplete type");
1416 if not Is_Entity_Name (P)
1417 or else not Is_Type (Entity (P))
1418 or else In_Spec_Expression
1422 Check_Fully_Declared (P_Type, P);
1424 end Check_Not_Incomplete_Type;
1426 ----------------------------
1427 -- Check_Object_Reference --
1428 ----------------------------
1430 procedure Check_Object_Reference (P : Node_Id) is
1434 -- If we need an object, and we have a prefix that is the name of
1435 -- a function entity, convert it into a function call.
1437 if Is_Entity_Name (P)
1438 and then Ekind (Entity (P)) = E_Function
1440 Rtyp := Etype (Entity (P));
1443 Make_Function_Call (Sloc (P),
1444 Name => Relocate_Node (P)));
1446 Analyze_And_Resolve (P, Rtyp);
1448 -- Otherwise we must have an object reference
1450 elsif not Is_Object_Reference (P) then
1451 Error_Attr_P ("prefix of % attribute must be object");
1453 end Check_Object_Reference;
1455 ----------------------------
1456 -- Check_PolyORB_Attribute --
1457 ----------------------------
1459 procedure Check_PolyORB_Attribute is
1461 Validate_Non_Static_Attribute_Function_Call;
1466 if Get_PCS_Name /= Name_PolyORB_DSA then
1468 ("attribute% requires the 'Poly'O'R'B 'P'C'S", N);
1470 end Check_PolyORB_Attribute;
1472 ------------------------
1473 -- Check_Program_Unit --
1474 ------------------------
1476 procedure Check_Program_Unit is
1478 if Is_Entity_Name (P) then
1480 K : constant Entity_Kind := Ekind (Entity (P));
1481 T : constant Entity_Id := Etype (Entity (P));
1484 if K in Subprogram_Kind
1485 or else K in Task_Kind
1486 or else K in Protected_Kind
1487 or else K = E_Package
1488 or else K in Generic_Unit_Kind
1489 or else (K = E_Variable
1493 Is_Protected_Type (T)))
1500 Error_Attr_P ("prefix of % attribute must be program unit");
1501 end Check_Program_Unit;
1503 ---------------------
1504 -- Check_Real_Type --
1505 ---------------------
1507 procedure Check_Real_Type is
1511 if not Is_Real_Type (P_Type) then
1512 Error_Attr_P ("prefix of % attribute must be real type");
1514 end Check_Real_Type;
1516 -----------------------
1517 -- Check_Scalar_Type --
1518 -----------------------
1520 procedure Check_Scalar_Type is
1524 if not Is_Scalar_Type (P_Type) then
1525 Error_Attr_P ("prefix of % attribute must be scalar type");
1527 end Check_Scalar_Type;
1529 ---------------------------
1530 -- Check_Standard_Prefix --
1531 ---------------------------
1533 procedure Check_Standard_Prefix is
1537 if Nkind (P) /= N_Identifier
1538 or else Chars (P) /= Name_Standard
1540 Error_Attr ("only allowed prefix for % attribute is Standard", P);
1542 end Check_Standard_Prefix;
1544 ----------------------------
1545 -- Check_Stream_Attribute --
1546 ----------------------------
1548 procedure Check_Stream_Attribute (Nam : TSS_Name_Type) is
1552 In_Shared_Var_Procs : Boolean;
1553 -- True when compiling the body of System.Shared_Storage.
1554 -- Shared_Var_Procs. For this runtime package (always compiled in
1555 -- GNAT mode), we allow stream attributes references for limited
1556 -- types for the case where shared passive objects are implemented
1557 -- using stream attributes, which is the default in GNAT's persistent
1558 -- storage implementation.
1561 Validate_Non_Static_Attribute_Function_Call;
1563 -- With the exception of 'Input, Stream attributes are procedures,
1564 -- and can only appear at the position of procedure calls. We check
1565 -- for this here, before they are rewritten, to give a more precise
1568 if Nam = TSS_Stream_Input then
1571 elsif Is_List_Member (N)
1572 and then not Nkind_In (Parent (N), N_Procedure_Call_Statement,
1579 ("invalid context for attribute%, which is a procedure", N);
1583 Btyp := Implementation_Base_Type (P_Type);
1585 -- Stream attributes not allowed on limited types unless the
1586 -- attribute reference was generated by the expander (in which
1587 -- case the underlying type will be used, as described in Sinfo),
1588 -- or the attribute was specified explicitly for the type itself
1589 -- or one of its ancestors (taking visibility rules into account if
1590 -- in Ada 2005 mode), or a pragma Stream_Convert applies to Btyp
1591 -- (with no visibility restriction).
1594 Gen_Body : constant Node_Id := Enclosing_Generic_Body (N);
1596 if Present (Gen_Body) then
1597 In_Shared_Var_Procs :=
1598 Is_RTE (Corresponding_Spec (Gen_Body), RE_Shared_Var_Procs);
1600 In_Shared_Var_Procs := False;
1604 if (Comes_From_Source (N)
1605 and then not (In_Shared_Var_Procs or In_Instance))
1606 and then not Stream_Attribute_Available (P_Type, Nam)
1607 and then not Has_Rep_Pragma (Btyp, Name_Stream_Convert)
1609 Error_Msg_Name_1 := Aname;
1611 if Is_Limited_Type (P_Type) then
1613 ("limited type& has no% attribute", P, P_Type);
1614 Explain_Limited_Type (P_Type, P);
1617 ("attribute% for type& is not available", P, P_Type);
1621 -- Check restriction violations
1623 -- First check the No_Streams restriction, which prohibits the use
1624 -- of explicit stream attributes in the source program. We do not
1625 -- prevent the occurrence of stream attributes in generated code,
1626 -- for instance those generated implicitly for dispatching purposes.
1628 if Comes_From_Source (N) then
1629 Check_Restriction (No_Streams, P);
1632 -- Check special case of Exception_Id and Exception_Occurrence which
1633 -- are not allowed for restriction No_Exception_Registration.
1635 if Is_RTE (P_Type, RE_Exception_Id)
1637 Is_RTE (P_Type, RE_Exception_Occurrence)
1639 Check_Restriction (No_Exception_Registration, P);
1642 -- Here we must check that the first argument is an access type
1643 -- that is compatible with Ada.Streams.Root_Stream_Type'Class.
1645 Analyze_And_Resolve (E1);
1648 -- Note: the double call to Root_Type here is needed because the
1649 -- root type of a class-wide type is the corresponding type (e.g.
1650 -- X for X'Class, and we really want to go to the root.)
1652 if not Is_Access_Type (Etyp)
1653 or else Root_Type (Root_Type (Designated_Type (Etyp))) /=
1654 RTE (RE_Root_Stream_Type)
1657 ("expected access to Ada.Streams.Root_Stream_Type''Class", E1);
1660 -- Check that the second argument is of the right type if there is
1661 -- one (the Input attribute has only one argument so this is skipped)
1663 if Present (E2) then
1666 if Nam = TSS_Stream_Read
1667 and then not Is_OK_Variable_For_Out_Formal (E2)
1670 ("second argument of % attribute must be a variable", E2);
1673 Resolve (E2, P_Type);
1677 end Check_Stream_Attribute;
1679 -----------------------
1680 -- Check_Task_Prefix --
1681 -----------------------
1683 procedure Check_Task_Prefix is
1687 -- Ada 2005 (AI-345): Attribute 'Terminated can be applied to
1688 -- task interface class-wide types.
1690 if Is_Task_Type (Etype (P))
1691 or else (Is_Access_Type (Etype (P))
1692 and then Is_Task_Type (Designated_Type (Etype (P))))
1693 or else (Ada_Version >= Ada_2005
1694 and then Ekind (Etype (P)) = E_Class_Wide_Type
1695 and then Is_Interface (Etype (P))
1696 and then Is_Task_Interface (Etype (P)))
1701 if Ada_Version >= Ada_2005 then
1703 ("prefix of % attribute must be a task or a task " &
1704 "interface class-wide object");
1707 Error_Attr_P ("prefix of % attribute must be a task");
1710 end Check_Task_Prefix;
1716 -- The possibilities are an entity name denoting a type, or an
1717 -- attribute reference that denotes a type (Base or Class). If
1718 -- the type is incomplete, replace it with its full view.
1720 procedure Check_Type is
1722 if not Is_Entity_Name (P)
1723 or else not Is_Type (Entity (P))
1725 Error_Attr_P ("prefix of % attribute must be a type");
1727 elsif Is_Protected_Self_Reference (P) then
1729 ("prefix of % attribute denotes current instance "
1730 & "(RM 9.4(21/2))");
1732 elsif Ekind (Entity (P)) = E_Incomplete_Type
1733 and then Present (Full_View (Entity (P)))
1735 P_Type := Full_View (Entity (P));
1736 Set_Entity (P, P_Type);
1740 ---------------------
1741 -- Check_Unit_Name --
1742 ---------------------
1744 procedure Check_Unit_Name (Nod : Node_Id) is
1746 if Nkind (Nod) = N_Identifier then
1749 elsif Nkind (Nod) = N_Selected_Component then
1750 Check_Unit_Name (Prefix (Nod));
1752 if Nkind (Selector_Name (Nod)) = N_Identifier then
1757 Error_Attr ("argument for % attribute must be unit name", P);
1758 end Check_Unit_Name;
1764 procedure Error_Attr is
1766 Set_Etype (N, Any_Type);
1767 Set_Entity (N, Any_Type);
1768 raise Bad_Attribute;
1771 procedure Error_Attr (Msg : String; Error_Node : Node_Id) is
1773 Error_Msg_Name_1 := Aname;
1774 Error_Msg_N (Msg, Error_Node);
1782 procedure Error_Attr_P (Msg : String) is
1784 Error_Msg_Name_1 := Aname;
1785 Error_Msg_F (Msg, P);
1789 ----------------------------
1790 -- Legal_Formal_Attribute --
1791 ----------------------------
1793 procedure Legal_Formal_Attribute is
1797 if not Is_Entity_Name (P)
1798 or else not Is_Type (Entity (P))
1800 Error_Attr_P ("prefix of % attribute must be generic type");
1802 elsif Is_Generic_Actual_Type (Entity (P))
1804 or else In_Inlined_Body
1808 elsif Is_Generic_Type (Entity (P)) then
1809 if not Is_Indefinite_Subtype (Entity (P)) then
1811 ("prefix of % attribute must be indefinite generic type");
1816 ("prefix of % attribute must be indefinite generic type");
1819 Set_Etype (N, Standard_Boolean);
1820 end Legal_Formal_Attribute;
1822 ------------------------
1823 -- Standard_Attribute --
1824 ------------------------
1826 procedure Standard_Attribute (Val : Int) is
1828 Check_Standard_Prefix;
1829 Rewrite (N, Make_Integer_Literal (Loc, Val));
1831 end Standard_Attribute;
1833 -------------------------
1834 -- Unexpected Argument --
1835 -------------------------
1837 procedure Unexpected_Argument (En : Node_Id) is
1839 Error_Attr ("unexpected argument for % attribute", En);
1840 end Unexpected_Argument;
1842 -------------------------------------------------
1843 -- Validate_Non_Static_Attribute_Function_Call --
1844 -------------------------------------------------
1846 -- This function should be moved to Sem_Dist ???
1848 procedure Validate_Non_Static_Attribute_Function_Call is
1850 if In_Preelaborated_Unit
1851 and then not In_Subprogram_Or_Concurrent_Unit
1853 Flag_Non_Static_Expr
1854 ("non-static function call in preelaborated unit!", N);
1856 end Validate_Non_Static_Attribute_Function_Call;
1858 -----------------------------------------------
1859 -- Start of Processing for Analyze_Attribute --
1860 -----------------------------------------------
1863 -- Immediate return if unrecognized attribute (already diagnosed
1864 -- by parser, so there is nothing more that we need to do)
1866 if not Is_Attribute_Name (Aname) then
1867 raise Bad_Attribute;
1870 -- Deal with Ada 83 issues
1872 if Comes_From_Source (N) then
1873 if not Attribute_83 (Attr_Id) then
1874 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1875 Error_Msg_Name_1 := Aname;
1876 Error_Msg_N ("(Ada 83) attribute% is not standard?", N);
1879 if Attribute_Impl_Def (Attr_Id) then
1880 Check_Restriction (No_Implementation_Attributes, N);
1885 -- Deal with Ada 2005 issues
1887 if Attribute_05 (Attr_Id) and then Ada_Version <= Ada_95 then
1888 Check_Restriction (No_Implementation_Attributes, N);
1891 -- Remote access to subprogram type access attribute reference needs
1892 -- unanalyzed copy for tree transformation. The analyzed copy is used
1893 -- for its semantic information (whether prefix is a remote subprogram
1894 -- name), the unanalyzed copy is used to construct new subtree rooted
1895 -- with N_Aggregate which represents a fat pointer aggregate.
1897 if Aname = Name_Access then
1898 Discard_Node (Copy_Separate_Tree (N));
1901 -- Analyze prefix and exit if error in analysis. If the prefix is an
1902 -- incomplete type, use full view if available. Note that there are
1903 -- some attributes for which we do not analyze the prefix, since the
1904 -- prefix is not a normal name.
1906 if Aname /= Name_Elab_Body
1908 Aname /= Name_Elab_Spec
1910 Aname /= Name_UET_Address
1912 Aname /= Name_Enabled
1915 P_Type := Etype (P);
1917 if Is_Entity_Name (P)
1918 and then Present (Entity (P))
1919 and then Is_Type (Entity (P))
1921 if Ekind (Entity (P)) = E_Incomplete_Type then
1922 P_Type := Get_Full_View (P_Type);
1923 Set_Entity (P, P_Type);
1924 Set_Etype (P, P_Type);
1926 elsif Entity (P) = Current_Scope
1927 and then Is_Record_Type (Entity (P))
1929 -- Use of current instance within the type. Verify that if the
1930 -- attribute appears within a constraint, it yields an access
1931 -- type, other uses are illegal.
1939 and then Nkind (Parent (Par)) /= N_Component_Definition
1941 Par := Parent (Par);
1945 and then Nkind (Par) = N_Subtype_Indication
1947 if Attr_Id /= Attribute_Access
1948 and then Attr_Id /= Attribute_Unchecked_Access
1949 and then Attr_Id /= Attribute_Unrestricted_Access
1952 ("in a constraint the current instance can only"
1953 & " be used with an access attribute", N);
1960 if P_Type = Any_Type then
1961 raise Bad_Attribute;
1964 P_Base_Type := Base_Type (P_Type);
1967 -- Analyze expressions that may be present, exiting if an error occurs
1974 E1 := First (Exprs);
1977 -- Check for missing/bad expression (result of previous error)
1979 if No (E1) or else Etype (E1) = Any_Type then
1980 raise Bad_Attribute;
1985 if Present (E2) then
1988 if Etype (E2) = Any_Type then
1989 raise Bad_Attribute;
1992 if Present (Next (E2)) then
1993 Unexpected_Argument (Next (E2));
1998 -- Ada 2005 (AI-345): Ensure that the compiler gives exactly the current
1999 -- output compiling in Ada 95 mode for the case of ambiguous prefixes.
2001 if Ada_Version < Ada_2005
2002 and then Is_Overloaded (P)
2003 and then Aname /= Name_Access
2004 and then Aname /= Name_Address
2005 and then Aname /= Name_Code_Address
2006 and then Aname /= Name_Count
2007 and then Aname /= Name_Result
2008 and then Aname /= Name_Unchecked_Access
2010 Error_Attr ("ambiguous prefix for % attribute", P);
2012 elsif Ada_Version >= Ada_2005
2013 and then Is_Overloaded (P)
2014 and then Aname /= Name_Access
2015 and then Aname /= Name_Address
2016 and then Aname /= Name_Code_Address
2017 and then Aname /= Name_Result
2018 and then Aname /= Name_Unchecked_Access
2020 -- Ada 2005 (AI-345): Since protected and task types have primitive
2021 -- entry wrappers, the attributes Count, Caller and AST_Entry require
2024 if Ada_Version >= Ada_2005
2025 and then (Aname = Name_Count
2026 or else Aname = Name_Caller
2027 or else Aname = Name_AST_Entry)
2030 Count : Natural := 0;
2035 Get_First_Interp (P, I, It);
2036 while Present (It.Nam) loop
2037 if Comes_From_Source (It.Nam) then
2043 Get_Next_Interp (I, It);
2047 Error_Attr ("ambiguous prefix for % attribute", P);
2049 Set_Is_Overloaded (P, False);
2054 Error_Attr ("ambiguous prefix for % attribute", P);
2058 -- In SPARK or ALFA, attributes of private types are only allowed if
2059 -- the full type declaration is visible
2061 if Formal_Verification_Mode
2062 and then Is_Entity_Name (P)
2063 and then Is_Type (Entity (P))
2064 and then Is_Private_Type (P_Type)
2065 and then not In_Open_Scopes (Scope (P_Type))
2066 and then not In_Spec_Expression
2069 ("invisible attribute of}", N, First_Subtype (P_Type));
2072 -- Remaining processing depends on attribute
2080 when Attribute_Abort_Signal =>
2081 Check_Standard_Prefix;
2082 Rewrite (N, New_Reference_To (Stand.Abort_Signal, Loc));
2089 when Attribute_Access =>
2090 Analyze_Access_Attribute;
2096 when Attribute_Address =>
2099 -- Check for some junk cases, where we have to allow the address
2100 -- attribute but it does not make much sense, so at least for now
2101 -- just replace with Null_Address.
2103 -- We also do this if the prefix is a reference to the AST_Entry
2104 -- attribute. If expansion is active, the attribute will be
2105 -- replaced by a function call, and address will work fine and
2106 -- get the proper value, but if expansion is not active, then
2107 -- the check here allows proper semantic analysis of the reference.
2109 -- An Address attribute created by expansion is legal even when it
2110 -- applies to other entity-denoting expressions.
2112 if Is_Protected_Self_Reference (P) then
2114 -- Address attribute on a protected object self reference is legal
2118 elsif Is_Entity_Name (P) then
2120 Ent : constant Entity_Id := Entity (P);
2123 if Is_Subprogram (Ent) then
2124 Set_Address_Taken (Ent);
2125 Kill_Current_Values (Ent);
2127 -- An Address attribute is accepted when generated by the
2128 -- compiler for dispatching operation, and an error is
2129 -- issued once the subprogram is frozen (to avoid confusing
2130 -- errors about implicit uses of Address in the dispatch
2131 -- table initialization).
2133 if Has_Pragma_Inline_Always (Entity (P))
2134 and then Comes_From_Source (P)
2137 ("prefix of % attribute cannot be Inline_Always" &
2140 -- It is illegal to apply 'Address to an intrinsic
2141 -- subprogram. This is now formalized in AI05-0095.
2142 -- In an instance, an attempt to obtain 'Address of an
2143 -- intrinsic subprogram (e.g the renaming of a predefined
2144 -- operator that is an actual) raises Program_Error.
2146 elsif Convention (Ent) = Convention_Intrinsic then
2149 Make_Raise_Program_Error (Loc,
2150 Reason => PE_Address_Of_Intrinsic));
2154 ("cannot take Address of intrinsic subprogram", N);
2157 -- Issue an error if prefix denotes an eliminated subprogram
2160 Check_For_Eliminated_Subprogram (P, Ent);
2163 elsif Is_Object (Ent)
2164 or else Ekind (Ent) = E_Label
2166 Set_Address_Taken (Ent);
2168 -- If we have an address of an object, and the attribute
2169 -- comes from source, then set the object as potentially
2170 -- source modified. We do this because the resulting address
2171 -- can potentially be used to modify the variable and we
2172 -- might not detect this, leading to some junk warnings.
2174 Set_Never_Set_In_Source (Ent, False);
2176 elsif (Is_Concurrent_Type (Etype (Ent))
2177 and then Etype (Ent) = Base_Type (Ent))
2178 or else Ekind (Ent) = E_Package
2179 or else Is_Generic_Unit (Ent)
2182 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
2185 Error_Attr ("invalid prefix for % attribute", P);
2189 elsif Nkind (P) = N_Attribute_Reference
2190 and then Attribute_Name (P) = Name_AST_Entry
2193 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
2195 elsif Is_Object_Reference (P) then
2198 elsif Nkind (P) = N_Selected_Component
2199 and then Is_Subprogram (Entity (Selector_Name (P)))
2203 -- What exactly are we allowing here ??? and is this properly
2204 -- documented in the sinfo documentation for this node ???
2206 elsif not Comes_From_Source (N) then
2210 Error_Attr ("invalid prefix for % attribute", P);
2213 Set_Etype (N, RTE (RE_Address));
2219 when Attribute_Address_Size =>
2220 Standard_Attribute (System_Address_Size);
2226 when Attribute_Adjacent =>
2227 Check_Floating_Point_Type_2;
2228 Set_Etype (N, P_Base_Type);
2229 Resolve (E1, P_Base_Type);
2230 Resolve (E2, P_Base_Type);
2236 when Attribute_Aft =>
2237 Check_Fixed_Point_Type_0;
2238 Set_Etype (N, Universal_Integer);
2244 when Attribute_Alignment =>
2246 -- Don't we need more checking here, cf Size ???
2249 Check_Not_Incomplete_Type;
2251 Set_Etype (N, Universal_Integer);
2257 when Attribute_Asm_Input =>
2258 Check_Asm_Attribute;
2260 -- The back-end may need to take the address of E2
2262 if Is_Entity_Name (E2) then
2263 Set_Address_Taken (Entity (E2));
2266 Set_Etype (N, RTE (RE_Asm_Input_Operand));
2272 when Attribute_Asm_Output =>
2273 Check_Asm_Attribute;
2275 if Etype (E2) = Any_Type then
2278 elsif Aname = Name_Asm_Output then
2279 if not Is_Variable (E2) then
2281 ("second argument for Asm_Output is not variable", E2);
2285 Note_Possible_Modification (E2, Sure => True);
2287 -- The back-end may need to take the address of E2
2289 if Is_Entity_Name (E2) then
2290 Set_Address_Taken (Entity (E2));
2293 Set_Etype (N, RTE (RE_Asm_Output_Operand));
2299 when Attribute_AST_Entry => AST_Entry : declare
2305 -- Indicates if entry family index is present. Note the coding
2306 -- here handles the entry family case, but in fact it cannot be
2307 -- executed currently, because pragma AST_Entry does not permit
2308 -- the specification of an entry family.
2310 procedure Bad_AST_Entry;
2311 -- Signal a bad AST_Entry pragma
2313 function OK_Entry (E : Entity_Id) return Boolean;
2314 -- Checks that E is of an appropriate entity kind for an entry
2315 -- (i.e. E_Entry if Index is False, or E_Entry_Family if Index
2316 -- is set True for the entry family case). In the True case,
2317 -- makes sure that Is_AST_Entry is set on the entry.
2323 procedure Bad_AST_Entry is
2325 Error_Attr_P ("prefix for % attribute must be task entry");
2332 function OK_Entry (E : Entity_Id) return Boolean is
2337 Result := (Ekind (E) = E_Entry_Family);
2339 Result := (Ekind (E) = E_Entry);
2343 if not Is_AST_Entry (E) then
2344 Error_Msg_Name_2 := Aname;
2345 Error_Attr ("% attribute requires previous % pragma", P);
2352 -- Start of processing for AST_Entry
2358 -- Deal with entry family case
2360 if Nkind (P) = N_Indexed_Component then
2368 Ptyp := Etype (Pref);
2370 if Ptyp = Any_Type or else Error_Posted (Pref) then
2374 -- If the prefix is a selected component whose prefix is of an
2375 -- access type, then introduce an explicit dereference.
2376 -- ??? Could we reuse Check_Dereference here?
2378 if Nkind (Pref) = N_Selected_Component
2379 and then Is_Access_Type (Ptyp)
2382 Make_Explicit_Dereference (Sloc (Pref),
2383 Relocate_Node (Pref)));
2384 Analyze_And_Resolve (Pref, Designated_Type (Ptyp));
2387 -- Prefix can be of the form a.b, where a is a task object
2388 -- and b is one of the entries of the corresponding task type.
2390 if Nkind (Pref) = N_Selected_Component
2391 and then OK_Entry (Entity (Selector_Name (Pref)))
2392 and then Is_Object_Reference (Prefix (Pref))
2393 and then Is_Task_Type (Etype (Prefix (Pref)))
2397 -- Otherwise the prefix must be an entry of a containing task,
2398 -- or of a variable of the enclosing task type.
2401 if Nkind_In (Pref, N_Identifier, N_Expanded_Name) then
2402 Ent := Entity (Pref);
2404 if not OK_Entry (Ent)
2405 or else not In_Open_Scopes (Scope (Ent))
2415 Set_Etype (N, RTE (RE_AST_Handler));
2422 -- Note: when the base attribute appears in the context of a subtype
2423 -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by
2424 -- the following circuit.
2426 when Attribute_Base => Base : declare
2434 if Ada_Version >= Ada_95
2435 and then not Is_Scalar_Type (Typ)
2436 and then not Is_Generic_Type (Typ)
2438 Error_Attr_P ("prefix of Base attribute must be scalar type");
2440 elsif Sloc (Typ) = Standard_Location
2441 and then Base_Type (Typ) = Typ
2442 and then Warn_On_Redundant_Constructs
2444 Error_Msg_NE -- CODEFIX
2445 ("?redundant attribute, & is its own base type", N, Typ);
2448 Set_Etype (N, Base_Type (Entity (P)));
2449 Set_Entity (N, Base_Type (Entity (P)));
2450 Rewrite (N, New_Reference_To (Entity (N), Loc));
2458 when Attribute_Bit => Bit :
2462 if not Is_Object_Reference (P) then
2463 Error_Attr_P ("prefix for % attribute must be object");
2465 -- What about the access object cases ???
2471 Set_Etype (N, Universal_Integer);
2478 when Attribute_Bit_Order => Bit_Order :
2483 if not Is_Record_Type (P_Type) then
2484 Error_Attr_P ("prefix of % attribute must be record type");
2487 if Bytes_Big_Endian xor Reverse_Bit_Order (P_Type) then
2489 New_Occurrence_Of (RTE (RE_High_Order_First), Loc));
2492 New_Occurrence_Of (RTE (RE_Low_Order_First), Loc));
2495 Set_Etype (N, RTE (RE_Bit_Order));
2498 -- Reset incorrect indication of staticness
2500 Set_Is_Static_Expression (N, False);
2507 -- Note: in generated code, we can have a Bit_Position attribute
2508 -- applied to a (naked) record component (i.e. the prefix is an
2509 -- identifier that references an E_Component or E_Discriminant
2510 -- entity directly, and this is interpreted as expected by Gigi.
2511 -- The following code will not tolerate such usage, but when the
2512 -- expander creates this special case, it marks it as analyzed
2513 -- immediately and sets an appropriate type.
2515 when Attribute_Bit_Position =>
2516 if Comes_From_Source (N) then
2520 Set_Etype (N, Universal_Integer);
2526 when Attribute_Body_Version =>
2529 Set_Etype (N, RTE (RE_Version_String));
2535 when Attribute_Callable =>
2537 Set_Etype (N, Standard_Boolean);
2544 when Attribute_Caller => Caller : declare
2551 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
2554 if not Is_Entry (Ent) then
2555 Error_Attr ("invalid entry name", N);
2559 Error_Attr ("invalid entry name", N);
2563 for J in reverse 0 .. Scope_Stack.Last loop
2564 S := Scope_Stack.Table (J).Entity;
2566 if S = Scope (Ent) then
2567 Error_Attr ("Caller must appear in matching accept or body", N);
2573 Set_Etype (N, RTE (RO_AT_Task_Id));
2580 when Attribute_Ceiling =>
2581 Check_Floating_Point_Type_1;
2582 Set_Etype (N, P_Base_Type);
2583 Resolve (E1, P_Base_Type);
2589 when Attribute_Class =>
2590 Check_Restriction (No_Dispatch, N);
2594 -- Applying Class to untagged incomplete type is obsolescent in Ada
2595 -- 2005. Note that we can't test Is_Tagged_Type here on P_Type, since
2596 -- this flag gets set by Find_Type in this situation.
2598 if Restriction_Check_Required (No_Obsolescent_Features)
2599 and then Ada_Version >= Ada_2005
2600 and then Ekind (P_Type) = E_Incomplete_Type
2603 DN : constant Node_Id := Declaration_Node (P_Type);
2605 if Nkind (DN) = N_Incomplete_Type_Declaration
2606 and then not Tagged_Present (DN)
2608 Check_Restriction (No_Obsolescent_Features, P);
2617 when Attribute_Code_Address =>
2620 if Nkind (P) = N_Attribute_Reference
2621 and then (Attribute_Name (P) = Name_Elab_Body
2623 Attribute_Name (P) = Name_Elab_Spec)
2627 elsif not Is_Entity_Name (P)
2628 or else (Ekind (Entity (P)) /= E_Function
2630 Ekind (Entity (P)) /= E_Procedure)
2632 Error_Attr ("invalid prefix for % attribute", P);
2633 Set_Address_Taken (Entity (P));
2635 -- Issue an error if the prefix denotes an eliminated subprogram
2638 Check_For_Eliminated_Subprogram (P, Entity (P));
2641 Set_Etype (N, RTE (RE_Address));
2643 ----------------------
2644 -- Compiler_Version --
2645 ----------------------
2647 when Attribute_Compiler_Version =>
2649 Check_Standard_Prefix;
2650 Rewrite (N, Make_String_Literal (Loc, "GNAT " & Gnat_Version_String));
2651 Analyze_And_Resolve (N, Standard_String);
2653 --------------------
2654 -- Component_Size --
2655 --------------------
2657 when Attribute_Component_Size =>
2659 Set_Etype (N, Universal_Integer);
2661 -- Note: unlike other array attributes, unconstrained arrays are OK
2663 if Is_Array_Type (P_Type) and then not Is_Constrained (P_Type) then
2673 when Attribute_Compose =>
2674 Check_Floating_Point_Type_2;
2675 Set_Etype (N, P_Base_Type);
2676 Resolve (E1, P_Base_Type);
2677 Resolve (E2, Any_Integer);
2683 when Attribute_Constrained =>
2685 Set_Etype (N, Standard_Boolean);
2687 -- Case from RM J.4(2) of constrained applied to private type
2689 if Is_Entity_Name (P) and then Is_Type (Entity (P)) then
2690 Check_Restriction (No_Obsolescent_Features, P);
2692 if Warn_On_Obsolescent_Feature then
2694 ("constrained for private type is an " &
2695 "obsolescent feature (RM J.4)?", N);
2698 -- If we are within an instance, the attribute must be legal
2699 -- because it was valid in the generic unit. Ditto if this is
2700 -- an inlining of a function declared in an instance.
2703 or else In_Inlined_Body
2707 -- For sure OK if we have a real private type itself, but must
2708 -- be completed, cannot apply Constrained to incomplete type.
2710 elsif Is_Private_Type (Entity (P)) then
2712 -- Note: this is one of the Annex J features that does not
2713 -- generate a warning from -gnatwj, since in fact it seems
2714 -- very useful, and is used in the GNAT runtime.
2716 Check_Not_Incomplete_Type;
2720 -- Normal (non-obsolescent case) of application to object of
2721 -- a discriminated type.
2724 Check_Object_Reference (P);
2726 -- If N does not come from source, then we allow the
2727 -- the attribute prefix to be of a private type whose
2728 -- full type has discriminants. This occurs in cases
2729 -- involving expanded calls to stream attributes.
2731 if not Comes_From_Source (N) then
2732 P_Type := Underlying_Type (P_Type);
2735 -- Must have discriminants or be an access type designating
2736 -- a type with discriminants. If it is a classwide type is ???
2737 -- has unknown discriminants.
2739 if Has_Discriminants (P_Type)
2740 or else Has_Unknown_Discriminants (P_Type)
2742 (Is_Access_Type (P_Type)
2743 and then Has_Discriminants (Designated_Type (P_Type)))
2747 -- Also allow an object of a generic type if extensions allowed
2748 -- and allow this for any type at all.
2750 elsif (Is_Generic_Type (P_Type)
2751 or else Is_Generic_Actual_Type (P_Type))
2752 and then Extensions_Allowed
2758 -- Fall through if bad prefix
2761 ("prefix of % attribute must be object of discriminated type");
2767 when Attribute_Copy_Sign =>
2768 Check_Floating_Point_Type_2;
2769 Set_Etype (N, P_Base_Type);
2770 Resolve (E1, P_Base_Type);
2771 Resolve (E2, P_Base_Type);
2777 when Attribute_Count => Count :
2786 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
2789 if Ekind (Ent) /= E_Entry then
2790 Error_Attr ("invalid entry name", N);
2793 elsif Nkind (P) = N_Indexed_Component then
2794 if not Is_Entity_Name (Prefix (P))
2795 or else No (Entity (Prefix (P)))
2796 or else Ekind (Entity (Prefix (P))) /= E_Entry_Family
2798 if Nkind (Prefix (P)) = N_Selected_Component
2799 and then Present (Entity (Selector_Name (Prefix (P))))
2800 and then Ekind (Entity (Selector_Name (Prefix (P)))) =
2804 ("attribute % must apply to entry of current task", P);
2807 Error_Attr ("invalid entry family name", P);
2812 Ent := Entity (Prefix (P));
2815 elsif Nkind (P) = N_Selected_Component
2816 and then Present (Entity (Selector_Name (P)))
2817 and then Ekind (Entity (Selector_Name (P))) = E_Entry
2820 ("attribute % must apply to entry of current task", P);
2823 Error_Attr ("invalid entry name", N);
2827 for J in reverse 0 .. Scope_Stack.Last loop
2828 S := Scope_Stack.Table (J).Entity;
2830 if S = Scope (Ent) then
2831 if Nkind (P) = N_Expanded_Name then
2832 Tsk := Entity (Prefix (P));
2834 -- The prefix denotes either the task type, or else a
2835 -- single task whose task type is being analyzed.
2840 or else (not Is_Type (Tsk)
2841 and then Etype (Tsk) = S
2842 and then not (Comes_From_Source (S)))
2847 ("Attribute % must apply to entry of current task", N);
2853 elsif Ekind (Scope (Ent)) in Task_Kind
2855 not Ekind_In (S, E_Loop, E_Block, E_Entry, E_Entry_Family)
2857 Error_Attr ("Attribute % cannot appear in inner unit", N);
2859 elsif Ekind (Scope (Ent)) = E_Protected_Type
2860 and then not Has_Completion (Scope (Ent))
2862 Error_Attr ("attribute % can only be used inside body", N);
2866 if Is_Overloaded (P) then
2868 Index : Interp_Index;
2872 Get_First_Interp (P, Index, It);
2874 while Present (It.Nam) loop
2875 if It.Nam = Ent then
2878 -- Ada 2005 (AI-345): Do not consider primitive entry
2879 -- wrappers generated for task or protected types.
2881 elsif Ada_Version >= Ada_2005
2882 and then not Comes_From_Source (It.Nam)
2887 Error_Attr ("ambiguous entry name", N);
2890 Get_Next_Interp (Index, It);
2895 Set_Etype (N, Universal_Integer);
2898 -----------------------
2899 -- Default_Bit_Order --
2900 -----------------------
2902 when Attribute_Default_Bit_Order => Default_Bit_Order :
2904 Check_Standard_Prefix;
2906 if Bytes_Big_Endian then
2908 Make_Integer_Literal (Loc, False_Value));
2911 Make_Integer_Literal (Loc, True_Value));
2914 Set_Etype (N, Universal_Integer);
2915 Set_Is_Static_Expression (N);
2916 end Default_Bit_Order;
2922 when Attribute_Definite =>
2923 Legal_Formal_Attribute;
2929 when Attribute_Delta =>
2930 Check_Fixed_Point_Type_0;
2931 Set_Etype (N, Universal_Real);
2937 when Attribute_Denorm =>
2938 Check_Floating_Point_Type_0;
2939 Set_Etype (N, Standard_Boolean);
2945 when Attribute_Digits =>
2949 if not Is_Floating_Point_Type (P_Type)
2950 and then not Is_Decimal_Fixed_Point_Type (P_Type)
2953 ("prefix of % attribute must be float or decimal type");
2956 Set_Etype (N, Universal_Integer);
2962 -- Also handles processing for Elab_Spec
2964 when Attribute_Elab_Body | Attribute_Elab_Spec =>
2966 Check_Unit_Name (P);
2967 Set_Etype (N, Standard_Void_Type);
2969 -- We have to manually call the expander in this case to get
2970 -- the necessary expansion (normally attributes that return
2971 -- entities are not expanded).
2979 -- Shares processing with Elab_Body
2985 when Attribute_Elaborated =>
2988 Set_Etype (N, Standard_Boolean);
2994 when Attribute_Emax =>
2995 Check_Floating_Point_Type_0;
2996 Set_Etype (N, Universal_Integer);
3002 when Attribute_Enabled =>
3003 Check_Either_E0_Or_E1;
3005 if Present (E1) then
3006 if not Is_Entity_Name (E1) or else No (Entity (E1)) then
3007 Error_Msg_N ("entity name expected for Enabled attribute", E1);
3012 if Nkind (P) /= N_Identifier then
3013 Error_Msg_N ("identifier expected (check name)", P);
3014 elsif Get_Check_Id (Chars (P)) = No_Check_Id then
3015 Error_Msg_N ("& is not a recognized check name", P);
3018 Set_Etype (N, Standard_Boolean);
3024 when Attribute_Enum_Rep => Enum_Rep : declare
3026 if Present (E1) then
3028 Check_Discrete_Type;
3029 Resolve (E1, P_Base_Type);
3032 if not Is_Entity_Name (P)
3033 or else (not Is_Object (Entity (P))
3035 Ekind (Entity (P)) /= E_Enumeration_Literal)
3038 ("prefix of % attribute must be " &
3039 "discrete type/object or enum literal");
3043 Set_Etype (N, Universal_Integer);
3050 when Attribute_Enum_Val => Enum_Val : begin
3054 if not Is_Enumeration_Type (P_Type) then
3055 Error_Attr_P ("prefix of % attribute must be enumeration type");
3058 -- If the enumeration type has a standard representation, the effect
3059 -- is the same as 'Val, so rewrite the attribute as a 'Val.
3061 if not Has_Non_Standard_Rep (P_Base_Type) then
3063 Make_Attribute_Reference (Loc,
3064 Prefix => Relocate_Node (Prefix (N)),
3065 Attribute_Name => Name_Val,
3066 Expressions => New_List (Relocate_Node (E1))));
3067 Analyze_And_Resolve (N, P_Base_Type);
3069 -- Non-standard representation case (enumeration with holes)
3073 Resolve (E1, Any_Integer);
3074 Set_Etype (N, P_Base_Type);
3082 when Attribute_Epsilon =>
3083 Check_Floating_Point_Type_0;
3084 Set_Etype (N, Universal_Real);
3090 when Attribute_Exponent =>
3091 Check_Floating_Point_Type_1;
3092 Set_Etype (N, Universal_Integer);
3093 Resolve (E1, P_Base_Type);
3099 when Attribute_External_Tag =>
3103 Set_Etype (N, Standard_String);
3105 if not Is_Tagged_Type (P_Type) then
3106 Error_Attr_P ("prefix of % attribute must be tagged");
3113 when Attribute_Fast_Math =>
3114 Check_Standard_Prefix;
3116 if Opt.Fast_Math then
3117 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
3119 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
3126 when Attribute_First =>
3127 Check_Array_Or_Scalar_Type;
3128 Bad_Attribute_For_Predicate;
3134 when Attribute_First_Bit =>
3136 Set_Etype (N, Universal_Integer);
3142 when Attribute_Fixed_Value =>
3144 Check_Fixed_Point_Type;
3145 Resolve (E1, Any_Integer);
3146 Set_Etype (N, P_Base_Type);
3152 when Attribute_Floor =>
3153 Check_Floating_Point_Type_1;
3154 Set_Etype (N, P_Base_Type);
3155 Resolve (E1, P_Base_Type);
3161 when Attribute_Fore =>
3162 Check_Fixed_Point_Type_0;
3163 Set_Etype (N, Universal_Integer);
3169 when Attribute_Fraction =>
3170 Check_Floating_Point_Type_1;
3171 Set_Etype (N, P_Base_Type);
3172 Resolve (E1, P_Base_Type);
3178 when Attribute_From_Any =>
3180 Check_PolyORB_Attribute;
3181 Set_Etype (N, P_Base_Type);
3183 -----------------------
3184 -- Has_Access_Values --
3185 -----------------------
3187 when Attribute_Has_Access_Values =>
3190 Set_Etype (N, Standard_Boolean);
3192 -----------------------
3193 -- Has_Tagged_Values --
3194 -----------------------
3196 when Attribute_Has_Tagged_Values =>
3199 Set_Etype (N, Standard_Boolean);
3201 -----------------------
3202 -- Has_Discriminants --
3203 -----------------------
3205 when Attribute_Has_Discriminants =>
3206 Legal_Formal_Attribute;
3212 when Attribute_Identity =>
3216 if Etype (P) = Standard_Exception_Type then
3217 Set_Etype (N, RTE (RE_Exception_Id));
3219 -- Ada 2005 (AI-345): Attribute 'Identity may be applied to
3220 -- task interface class-wide types.
3222 elsif Is_Task_Type (Etype (P))
3223 or else (Is_Access_Type (Etype (P))
3224 and then Is_Task_Type (Designated_Type (Etype (P))))
3225 or else (Ada_Version >= Ada_2005
3226 and then Ekind (Etype (P)) = E_Class_Wide_Type
3227 and then Is_Interface (Etype (P))
3228 and then Is_Task_Interface (Etype (P)))
3231 Set_Etype (N, RTE (RO_AT_Task_Id));
3234 if Ada_Version >= Ada_2005 then
3236 ("prefix of % attribute must be an exception, a " &
3237 "task or a task interface class-wide object");
3240 ("prefix of % attribute must be a task or an exception");
3248 when Attribute_Image => Image :
3250 Set_Etype (N, Standard_String);
3253 if Is_Real_Type (P_Type) then
3254 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3255 Error_Msg_Name_1 := Aname;
3257 ("(Ada 83) % attribute not allowed for real types", N);
3261 if Is_Enumeration_Type (P_Type) then
3262 Check_Restriction (No_Enumeration_Maps, N);
3266 Resolve (E1, P_Base_Type);
3268 Validate_Non_Static_Attribute_Function_Call;
3275 when Attribute_Img => Img :
3278 Set_Etype (N, Standard_String);
3280 if not Is_Scalar_Type (P_Type)
3281 or else (Is_Entity_Name (P) and then Is_Type (Entity (P)))
3284 ("prefix of % attribute must be scalar object name");
3294 when Attribute_Input =>
3296 Check_Stream_Attribute (TSS_Stream_Input);
3297 Set_Etype (N, P_Base_Type);
3303 when Attribute_Integer_Value =>
3306 Resolve (E1, Any_Fixed);
3308 -- Signal an error if argument type is not a specific fixed-point
3309 -- subtype. An error has been signalled already if the argument
3310 -- was not of a fixed-point type.
3312 if Etype (E1) = Any_Fixed and then not Error_Posted (E1) then
3313 Error_Attr ("argument of % must be of a fixed-point type", E1);
3316 Set_Etype (N, P_Base_Type);
3322 when Attribute_Invalid_Value =>
3325 Set_Etype (N, P_Base_Type);
3326 Invalid_Value_Used := True;
3332 when Attribute_Large =>
3335 Set_Etype (N, Universal_Real);
3341 when Attribute_Last =>
3342 Check_Array_Or_Scalar_Type;
3343 Bad_Attribute_For_Predicate;
3349 when Attribute_Last_Bit =>
3351 Set_Etype (N, Universal_Integer);
3357 when Attribute_Leading_Part =>
3358 Check_Floating_Point_Type_2;
3359 Set_Etype (N, P_Base_Type);
3360 Resolve (E1, P_Base_Type);
3361 Resolve (E2, Any_Integer);
3367 when Attribute_Length =>
3369 Set_Etype (N, Universal_Integer);
3375 when Attribute_Machine =>
3376 Check_Floating_Point_Type_1;
3377 Set_Etype (N, P_Base_Type);
3378 Resolve (E1, P_Base_Type);
3384 when Attribute_Machine_Emax =>
3385 Check_Floating_Point_Type_0;
3386 Set_Etype (N, Universal_Integer);
3392 when Attribute_Machine_Emin =>
3393 Check_Floating_Point_Type_0;
3394 Set_Etype (N, Universal_Integer);
3396 ----------------------
3397 -- Machine_Mantissa --
3398 ----------------------
3400 when Attribute_Machine_Mantissa =>
3401 Check_Floating_Point_Type_0;
3402 Set_Etype (N, Universal_Integer);
3404 -----------------------
3405 -- Machine_Overflows --
3406 -----------------------
3408 when Attribute_Machine_Overflows =>
3411 Set_Etype (N, Standard_Boolean);
3417 when Attribute_Machine_Radix =>
3420 Set_Etype (N, Universal_Integer);
3422 ----------------------
3423 -- Machine_Rounding --
3424 ----------------------
3426 when Attribute_Machine_Rounding =>
3427 Check_Floating_Point_Type_1;
3428 Set_Etype (N, P_Base_Type);
3429 Resolve (E1, P_Base_Type);
3431 --------------------
3432 -- Machine_Rounds --
3433 --------------------
3435 when Attribute_Machine_Rounds =>
3438 Set_Etype (N, Standard_Boolean);
3444 when Attribute_Machine_Size =>
3447 Check_Not_Incomplete_Type;
3448 Set_Etype (N, Universal_Integer);
3454 when Attribute_Mantissa =>
3457 Set_Etype (N, Universal_Integer);
3463 when Attribute_Max =>
3466 Resolve (E1, P_Base_Type);
3467 Resolve (E2, P_Base_Type);
3468 Set_Etype (N, P_Base_Type);
3470 ----------------------------------
3471 -- Max_Alignment_For_Allocation --
3472 -- Max_Size_In_Storage_Elements --
3473 ----------------------------------
3475 when Attribute_Max_Alignment_For_Allocation |
3476 Attribute_Max_Size_In_Storage_Elements =>
3479 Check_Not_Incomplete_Type;
3480 Set_Etype (N, Universal_Integer);
3482 -----------------------
3483 -- Maximum_Alignment --
3484 -----------------------
3486 when Attribute_Maximum_Alignment =>
3487 Standard_Attribute (Ttypes.Maximum_Alignment);
3489 --------------------
3490 -- Mechanism_Code --
3491 --------------------
3493 when Attribute_Mechanism_Code =>
3494 if not Is_Entity_Name (P)
3495 or else not Is_Subprogram (Entity (P))
3497 Error_Attr_P ("prefix of % attribute must be subprogram");
3500 Check_Either_E0_Or_E1;
3502 if Present (E1) then
3503 Resolve (E1, Any_Integer);
3504 Set_Etype (E1, Standard_Integer);
3506 if not Is_Static_Expression (E1) then
3507 Flag_Non_Static_Expr
3508 ("expression for parameter number must be static!", E1);
3511 elsif UI_To_Int (Intval (E1)) > Number_Formals (Entity (P))
3512 or else UI_To_Int (Intval (E1)) < 0
3514 Error_Attr ("invalid parameter number for % attribute", E1);
3518 Set_Etype (N, Universal_Integer);
3524 when Attribute_Min =>
3527 Resolve (E1, P_Base_Type);
3528 Resolve (E2, P_Base_Type);
3529 Set_Etype (N, P_Base_Type);
3535 when Attribute_Mod =>
3537 -- Note: this attribute is only allowed in Ada 2005 mode, but
3538 -- we do not need to test that here, since Mod is only recognized
3539 -- as an attribute name in Ada 2005 mode during the parse.
3542 Check_Modular_Integer_Type;
3543 Resolve (E1, Any_Integer);
3544 Set_Etype (N, P_Base_Type);
3550 when Attribute_Model =>
3551 Check_Floating_Point_Type_1;
3552 Set_Etype (N, P_Base_Type);
3553 Resolve (E1, P_Base_Type);
3559 when Attribute_Model_Emin =>
3560 Check_Floating_Point_Type_0;
3561 Set_Etype (N, Universal_Integer);
3567 when Attribute_Model_Epsilon =>
3568 Check_Floating_Point_Type_0;
3569 Set_Etype (N, Universal_Real);
3571 --------------------
3572 -- Model_Mantissa --
3573 --------------------
3575 when Attribute_Model_Mantissa =>
3576 Check_Floating_Point_Type_0;
3577 Set_Etype (N, Universal_Integer);
3583 when Attribute_Model_Small =>
3584 Check_Floating_Point_Type_0;
3585 Set_Etype (N, Universal_Real);
3591 when Attribute_Modulus =>
3593 Check_Modular_Integer_Type;
3594 Set_Etype (N, Universal_Integer);
3596 --------------------
3597 -- Null_Parameter --
3598 --------------------
3600 when Attribute_Null_Parameter => Null_Parameter : declare
3601 Parnt : constant Node_Id := Parent (N);
3602 GParnt : constant Node_Id := Parent (Parnt);
3604 procedure Bad_Null_Parameter (Msg : String);
3605 -- Used if bad Null parameter attribute node is found. Issues
3606 -- given error message, and also sets the type to Any_Type to
3607 -- avoid blowups later on from dealing with a junk node.
3609 procedure Must_Be_Imported (Proc_Ent : Entity_Id);
3610 -- Called to check that Proc_Ent is imported subprogram
3612 ------------------------
3613 -- Bad_Null_Parameter --
3614 ------------------------
3616 procedure Bad_Null_Parameter (Msg : String) is
3618 Error_Msg_N (Msg, N);
3619 Set_Etype (N, Any_Type);
3620 end Bad_Null_Parameter;
3622 ----------------------
3623 -- Must_Be_Imported --
3624 ----------------------
3626 procedure Must_Be_Imported (Proc_Ent : Entity_Id) is
3627 Pent : constant Entity_Id := Ultimate_Alias (Proc_Ent);
3630 -- Ignore check if procedure not frozen yet (we will get
3631 -- another chance when the default parameter is reanalyzed)
3633 if not Is_Frozen (Pent) then
3636 elsif not Is_Imported (Pent) then
3638 ("Null_Parameter can only be used with imported subprogram");
3643 end Must_Be_Imported;
3645 -- Start of processing for Null_Parameter
3650 Set_Etype (N, P_Type);
3652 -- Case of attribute used as default expression
3654 if Nkind (Parnt) = N_Parameter_Specification then
3655 Must_Be_Imported (Defining_Entity (GParnt));
3657 -- Case of attribute used as actual for subprogram (positional)
3659 elsif Nkind_In (Parnt, N_Procedure_Call_Statement,
3661 and then Is_Entity_Name (Name (Parnt))
3663 Must_Be_Imported (Entity (Name (Parnt)));
3665 -- Case of attribute used as actual for subprogram (named)
3667 elsif Nkind (Parnt) = N_Parameter_Association
3668 and then Nkind_In (GParnt, N_Procedure_Call_Statement,
3670 and then Is_Entity_Name (Name (GParnt))
3672 Must_Be_Imported (Entity (Name (GParnt)));
3674 -- Not an allowed case
3678 ("Null_Parameter must be actual or default parameter");
3686 when Attribute_Object_Size =>
3689 Check_Not_Incomplete_Type;
3690 Set_Etype (N, Universal_Integer);
3696 when Attribute_Old =>
3698 -- The attribute reference is a primary. If expressions follow, the
3699 -- attribute reference is an indexable object, so rewrite the node
3702 if Present (E1) then
3704 Make_Indexed_Component (Loc,
3706 Make_Attribute_Reference (Loc,
3707 Prefix => Relocate_Node (Prefix (N)),
3708 Attribute_Name => Name_Old),
3709 Expressions => Expressions (N)));
3716 Set_Etype (N, P_Type);
3718 if No (Current_Subprogram) then
3719 Error_Attr ("attribute % can only appear within subprogram", N);
3722 if Is_Limited_Type (P_Type) then
3723 Error_Attr ("attribute % cannot apply to limited objects", P);
3726 if Is_Entity_Name (P)
3727 and then Is_Constant_Object (Entity (P))
3730 ("?attribute Old applied to constant has no effect", P);
3733 -- Check that the expression does not refer to local entities
3735 Check_Local : declare
3736 Subp : Entity_Id := Current_Subprogram;
3738 function Process (N : Node_Id) return Traverse_Result;
3739 -- Check that N does not contain references to local variables or
3740 -- other local entities of Subp.
3746 function Process (N : Node_Id) return Traverse_Result is
3748 if Is_Entity_Name (N)
3749 and then Present (Entity (N))
3750 and then not Is_Formal (Entity (N))
3751 and then Enclosing_Subprogram (Entity (N)) = Subp
3753 Error_Msg_Node_1 := Entity (N);
3755 ("attribute % cannot refer to local variable&", N);
3761 procedure Check_No_Local is new Traverse_Proc;
3763 -- Start of processing for Check_Local
3768 if In_Parameter_Specification (P) then
3770 -- We have additional restrictions on using 'Old in parameter
3773 if Present (Enclosing_Subprogram (Current_Subprogram)) then
3775 -- Check that there is no reference to the enclosing
3776 -- subprogram local variables. Otherwise, we might end up
3777 -- being called from the enclosing subprogram and thus using
3778 -- 'Old on a local variable which is not defined at entry
3781 Subp := Enclosing_Subprogram (Current_Subprogram);
3785 -- We must prevent default expression of library-level
3786 -- subprogram from using 'Old, as the subprogram may be
3787 -- used in elaboration code for which there is no enclosing
3791 ("attribute % can only appear within subprogram", N);
3800 when Attribute_Output =>
3802 Check_Stream_Attribute (TSS_Stream_Output);
3803 Set_Etype (N, Standard_Void_Type);
3804 Resolve (N, Standard_Void_Type);
3810 when Attribute_Partition_ID => Partition_Id :
3814 if P_Type /= Any_Type then
3815 if not Is_Library_Level_Entity (Entity (P)) then
3817 ("prefix of % attribute must be library-level entity");
3819 -- The defining entity of prefix should not be declared inside a
3820 -- Pure unit. RM E.1(8). Is_Pure was set during declaration.
3822 elsif Is_Entity_Name (P)
3823 and then Is_Pure (Entity (P))
3825 Error_Attr_P ("prefix of% attribute must not be declared pure");
3829 Set_Etype (N, Universal_Integer);
3832 -------------------------
3833 -- Passed_By_Reference --
3834 -------------------------
3836 when Attribute_Passed_By_Reference =>
3839 Set_Etype (N, Standard_Boolean);
3845 when Attribute_Pool_Address =>
3847 Set_Etype (N, RTE (RE_Address));
3853 when Attribute_Pos =>
3854 Check_Discrete_Type;
3856 Resolve (E1, P_Base_Type);
3857 Set_Etype (N, Universal_Integer);
3863 when Attribute_Position =>
3865 Set_Etype (N, Universal_Integer);
3871 when Attribute_Pred =>
3874 Resolve (E1, P_Base_Type);
3875 Set_Etype (N, P_Base_Type);
3877 -- Nothing to do for real type case
3879 if Is_Real_Type (P_Type) then
3882 -- If not modular type, test for overflow check required
3885 if not Is_Modular_Integer_Type (P_Type)
3886 and then not Range_Checks_Suppressed (P_Base_Type)
3888 Enable_Range_Check (E1);
3896 -- Ada 2005 (AI-327): Dynamic ceiling priorities
3898 when Attribute_Priority =>
3899 if Ada_Version < Ada_2005 then
3900 Error_Attr ("% attribute is allowed only in Ada 2005 mode", P);
3905 -- The prefix must be a protected object (AARM D.5.2 (2/2))
3909 if Is_Protected_Type (Etype (P))
3910 or else (Is_Access_Type (Etype (P))
3911 and then Is_Protected_Type (Designated_Type (Etype (P))))
3913 Resolve (P, Etype (P));
3915 Error_Attr_P ("prefix of % attribute must be a protected object");
3918 Set_Etype (N, Standard_Integer);
3920 -- Must be called from within a protected procedure or entry of the
3921 -- protected object.
3928 while S /= Etype (P)
3929 and then S /= Standard_Standard
3934 if S = Standard_Standard then
3935 Error_Attr ("the attribute % is only allowed inside protected "
3940 Validate_Non_Static_Attribute_Function_Call;
3946 when Attribute_Range =>
3947 Check_Array_Or_Scalar_Type;
3948 Bad_Attribute_For_Predicate;
3950 if Ada_Version = Ada_83
3951 and then Is_Scalar_Type (P_Type)
3952 and then Comes_From_Source (N)
3955 ("(Ada 83) % attribute not allowed for scalar type", P);
3962 when Attribute_Result => Result : declare
3964 -- The enclosing scope, excluding loops for quantified expressions
3967 -- During analysis, CS is the postcondition subprogram and PS the
3968 -- source subprogram to which the postcondition applies. During
3969 -- pre-analysis, CS is the scope of the subprogram declaration.
3972 -- Find enclosing scopes, excluding loops
3974 CS := Current_Scope;
3975 while Ekind (CS) = E_Loop loop
3981 -- If the enclosing subprogram is always inlined, the enclosing
3982 -- postcondition will not be propagated to the expanded call.
3984 if not In_Spec_Expression
3985 and then Has_Pragma_Inline_Always (PS)
3986 and then Warn_On_Redundant_Constructs
3989 ("postconditions on inlined functions not enforced?", N);
3992 -- If we are in the scope of a function and in Spec_Expression mode,
3993 -- this is likely the prescan of the postcondition pragma, and we
3994 -- just set the proper type. If there is an error it will be caught
3995 -- when the real Analyze call is done.
3997 if Ekind (CS) = E_Function
3998 and then In_Spec_Expression
4002 if Chars (CS) /= Chars (P) then
4004 ("incorrect prefix for % attribute, expected &", P, CS);
4008 Set_Etype (N, Etype (CS));
4010 -- If several functions with that name are visible,
4011 -- the intended one is the current scope.
4013 if Is_Overloaded (P) then
4015 Set_Is_Overloaded (P, False);
4018 -- Body case, where we must be inside a generated _Postcondition
4019 -- procedure, and the prefix must be on the scope stack, or else
4020 -- the attribute use is definitely misplaced. The condition itself
4021 -- may have generated transient scopes, and is not necessarily the
4025 while Present (CS) and then CS /= Standard_Standard loop
4026 if Chars (CS) = Name_uPostconditions then
4035 if Chars (CS) = Name_uPostconditions
4036 and then Ekind (PS) = E_Function
4040 if Nkind_In (P, N_Identifier, N_Operator_Symbol)
4041 and then Chars (P) = Chars (PS)
4045 -- Within an instance, the prefix designates the local renaming
4046 -- of the original generic.
4048 elsif Is_Entity_Name (P)
4049 and then Ekind (Entity (P)) = E_Function
4050 and then Present (Alias (Entity (P)))
4051 and then Chars (Alias (Entity (P))) = Chars (PS)
4057 ("incorrect prefix for % attribute, expected &", P, PS);
4061 Rewrite (N, Make_Identifier (Sloc (N), Name_uResult));
4062 Analyze_And_Resolve (N, Etype (PS));
4066 ("% attribute can only appear" &
4067 " in function Postcondition pragma", P);
4076 when Attribute_Range_Length =>
4078 Check_Discrete_Type;
4079 Set_Etype (N, Universal_Integer);
4085 when Attribute_Read =>
4087 Check_Stream_Attribute (TSS_Stream_Read);
4088 Set_Etype (N, Standard_Void_Type);
4089 Resolve (N, Standard_Void_Type);
4090 Note_Possible_Modification (E2, Sure => True);
4096 when Attribute_Ref =>
4100 if Nkind (P) /= N_Expanded_Name
4101 or else not Is_RTE (P_Type, RE_Address)
4103 Error_Attr_P ("prefix of % attribute must be System.Address");
4106 Analyze_And_Resolve (E1, Any_Integer);
4107 Set_Etype (N, RTE (RE_Address));
4113 when Attribute_Remainder =>
4114 Check_Floating_Point_Type_2;
4115 Set_Etype (N, P_Base_Type);
4116 Resolve (E1, P_Base_Type);
4117 Resolve (E2, P_Base_Type);
4123 when Attribute_Round =>
4125 Check_Decimal_Fixed_Point_Type;
4126 Set_Etype (N, P_Base_Type);
4128 -- Because the context is universal_real (3.5.10(12)) it is a legal
4129 -- context for a universal fixed expression. This is the only
4130 -- attribute whose functional description involves U_R.
4132 if Etype (E1) = Universal_Fixed then
4134 Conv : constant Node_Id := Make_Type_Conversion (Loc,
4135 Subtype_Mark => New_Occurrence_Of (Universal_Real, Loc),
4136 Expression => Relocate_Node (E1));
4144 Resolve (E1, Any_Real);
4150 when Attribute_Rounding =>
4151 Check_Floating_Point_Type_1;
4152 Set_Etype (N, P_Base_Type);
4153 Resolve (E1, P_Base_Type);
4159 when Attribute_Safe_Emax =>
4160 Check_Floating_Point_Type_0;
4161 Set_Etype (N, Universal_Integer);
4167 when Attribute_Safe_First =>
4168 Check_Floating_Point_Type_0;
4169 Set_Etype (N, Universal_Real);
4175 when Attribute_Safe_Large =>
4178 Set_Etype (N, Universal_Real);
4184 when Attribute_Safe_Last =>
4185 Check_Floating_Point_Type_0;
4186 Set_Etype (N, Universal_Real);
4192 when Attribute_Safe_Small =>
4195 Set_Etype (N, Universal_Real);
4201 when Attribute_Scale =>
4203 Check_Decimal_Fixed_Point_Type;
4204 Set_Etype (N, Universal_Integer);
4210 when Attribute_Scaling =>
4211 Check_Floating_Point_Type_2;
4212 Set_Etype (N, P_Base_Type);
4213 Resolve (E1, P_Base_Type);
4219 when Attribute_Signed_Zeros =>
4220 Check_Floating_Point_Type_0;
4221 Set_Etype (N, Standard_Boolean);
4227 when Attribute_Size | Attribute_VADS_Size => Size :
4231 -- If prefix is parameterless function call, rewrite and resolve
4234 if Is_Entity_Name (P)
4235 and then Ekind (Entity (P)) = E_Function
4239 -- Similar processing for a protected function call
4241 elsif Nkind (P) = N_Selected_Component
4242 and then Ekind (Entity (Selector_Name (P))) = E_Function
4247 if Is_Object_Reference (P) then
4248 Check_Object_Reference (P);
4250 elsif Is_Entity_Name (P)
4251 and then (Is_Type (Entity (P))
4252 or else Ekind (Entity (P)) = E_Enumeration_Literal)
4256 elsif Nkind (P) = N_Type_Conversion
4257 and then not Comes_From_Source (P)
4262 Error_Attr_P ("invalid prefix for % attribute");
4265 Check_Not_Incomplete_Type;
4267 Set_Etype (N, Universal_Integer);
4274 when Attribute_Small =>
4277 Set_Etype (N, Universal_Real);
4283 when Attribute_Storage_Pool => Storage_Pool :
4287 if Is_Access_Type (P_Type) then
4288 if Ekind (P_Type) = E_Access_Subprogram_Type then
4290 ("cannot use % attribute for access-to-subprogram type");
4293 -- Set appropriate entity
4295 if Present (Associated_Storage_Pool (Root_Type (P_Type))) then
4296 Set_Entity (N, Associated_Storage_Pool (Root_Type (P_Type)));
4298 Set_Entity (N, RTE (RE_Global_Pool_Object));
4301 Set_Etype (N, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
4303 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4304 -- Storage_Pool since this attribute is not defined for such
4305 -- types (RM E.2.3(22)).
4307 Validate_Remote_Access_To_Class_Wide_Type (N);
4310 Error_Attr_P ("prefix of % attribute must be access type");
4318 when Attribute_Storage_Size => Storage_Size :
4322 if Is_Task_Type (P_Type) then
4323 Set_Etype (N, Universal_Integer);
4325 -- Use with tasks is an obsolescent feature
4327 Check_Restriction (No_Obsolescent_Features, P);
4329 elsif Is_Access_Type (P_Type) then
4330 if Ekind (P_Type) = E_Access_Subprogram_Type then
4332 ("cannot use % attribute for access-to-subprogram type");
4335 if Is_Entity_Name (P)
4336 and then Is_Type (Entity (P))
4339 Set_Etype (N, Universal_Integer);
4341 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4342 -- Storage_Size since this attribute is not defined for
4343 -- such types (RM E.2.3(22)).
4345 Validate_Remote_Access_To_Class_Wide_Type (N);
4347 -- The prefix is allowed to be an implicit dereference
4348 -- of an access value designating a task.
4352 Set_Etype (N, Universal_Integer);
4356 Error_Attr_P ("prefix of % attribute must be access or task type");
4364 when Attribute_Storage_Unit =>
4365 Standard_Attribute (Ttypes.System_Storage_Unit);
4371 when Attribute_Stream_Size =>
4375 if Is_Entity_Name (P)
4376 and then Is_Elementary_Type (Entity (P))
4378 Set_Etype (N, Universal_Integer);
4380 Error_Attr_P ("invalid prefix for % attribute");
4387 when Attribute_Stub_Type =>
4391 if Is_Remote_Access_To_Class_Wide_Type (P_Type) then
4393 New_Occurrence_Of (Corresponding_Stub_Type (P_Type), Loc));
4396 ("prefix of% attribute must be remote access to classwide");
4403 when Attribute_Succ =>
4406 Resolve (E1, P_Base_Type);
4407 Set_Etype (N, P_Base_Type);
4409 -- Nothing to do for real type case
4411 if Is_Real_Type (P_Type) then
4414 -- If not modular type, test for overflow check required
4417 if not Is_Modular_Integer_Type (P_Type)
4418 and then not Range_Checks_Suppressed (P_Base_Type)
4420 Enable_Range_Check (E1);
4428 when Attribute_Tag => Tag :
4433 if not Is_Tagged_Type (P_Type) then
4434 Error_Attr_P ("prefix of % attribute must be tagged");
4436 -- Next test does not apply to generated code
4437 -- why not, and what does the illegal reference mean???
4439 elsif Is_Object_Reference (P)
4440 and then not Is_Class_Wide_Type (P_Type)
4441 and then Comes_From_Source (N)
4444 ("% attribute can only be applied to objects " &
4445 "of class - wide type");
4448 -- The prefix cannot be an incomplete type. However, references
4449 -- to 'Tag can be generated when expanding interface conversions,
4450 -- and this is legal.
4452 if Comes_From_Source (N) then
4453 Check_Not_Incomplete_Type;
4456 -- Set appropriate type
4458 Set_Etype (N, RTE (RE_Tag));
4465 when Attribute_Target_Name => Target_Name : declare
4466 TN : constant String := Sdefault.Target_Name.all;
4470 Check_Standard_Prefix;
4474 if TN (TL) = '/' or else TN (TL) = '\' then
4479 Make_String_Literal (Loc,
4480 Strval => TN (TN'First .. TL)));
4481 Analyze_And_Resolve (N, Standard_String);
4488 when Attribute_Terminated =>
4490 Set_Etype (N, Standard_Boolean);
4497 when Attribute_To_Address =>
4501 if Nkind (P) /= N_Identifier
4502 or else Chars (P) /= Name_System
4504 Error_Attr_P ("prefix of % attribute must be System");
4507 Generate_Reference (RTE (RE_Address), P);
4508 Analyze_And_Resolve (E1, Any_Integer);
4509 Set_Etype (N, RTE (RE_Address));
4515 when Attribute_To_Any =>
4517 Check_PolyORB_Attribute;
4518 Set_Etype (N, RTE (RE_Any));
4524 when Attribute_Truncation =>
4525 Check_Floating_Point_Type_1;
4526 Resolve (E1, P_Base_Type);
4527 Set_Etype (N, P_Base_Type);
4533 when Attribute_Type_Class =>
4536 Check_Not_Incomplete_Type;
4537 Set_Etype (N, RTE (RE_Type_Class));
4543 when Attribute_TypeCode =>
4545 Check_PolyORB_Attribute;
4546 Set_Etype (N, RTE (RE_TypeCode));
4552 when Attribute_Type_Key =>
4556 -- This processing belongs in Eval_Attribute ???
4559 function Type_Key return String_Id;
4560 -- A very preliminary implementation. For now, a signature
4561 -- consists of only the type name. This is clearly incomplete
4562 -- (e.g., adding a new field to a record type should change the
4563 -- type's Type_Key attribute).
4569 function Type_Key return String_Id is
4570 Full_Name : constant String_Id :=
4571 Fully_Qualified_Name_String (Entity (P));
4574 -- Copy all characters in Full_Name but the trailing NUL
4577 for J in 1 .. String_Length (Full_Name) - 1 loop
4578 Store_String_Char (Get_String_Char (Full_Name, Int (J)));
4581 Store_String_Chars ("'Type_Key");
4586 Rewrite (N, Make_String_Literal (Loc, Type_Key));
4589 Analyze_And_Resolve (N, Standard_String);
4595 when Attribute_UET_Address =>
4597 Check_Unit_Name (P);
4598 Set_Etype (N, RTE (RE_Address));
4600 -----------------------
4601 -- Unbiased_Rounding --
4602 -----------------------
4604 when Attribute_Unbiased_Rounding =>
4605 Check_Floating_Point_Type_1;
4606 Set_Etype (N, P_Base_Type);
4607 Resolve (E1, P_Base_Type);
4609 ----------------------
4610 -- Unchecked_Access --
4611 ----------------------
4613 when Attribute_Unchecked_Access =>
4614 if Comes_From_Source (N) then
4615 Check_Restriction (No_Unchecked_Access, N);
4618 Analyze_Access_Attribute;
4620 -------------------------
4621 -- Unconstrained_Array --
4622 -------------------------
4624 when Attribute_Unconstrained_Array =>
4627 Check_Not_Incomplete_Type;
4628 Set_Etype (N, Standard_Boolean);
4630 ------------------------------
4631 -- Universal_Literal_String --
4632 ------------------------------
4634 -- This is a GNAT specific attribute whose prefix must be a named
4635 -- number where the expression is either a single numeric literal,
4636 -- or a numeric literal immediately preceded by a minus sign. The
4637 -- result is equivalent to a string literal containing the text of
4638 -- the literal as it appeared in the source program with a possible
4639 -- leading minus sign.
4641 when Attribute_Universal_Literal_String => Universal_Literal_String :
4645 if not Is_Entity_Name (P)
4646 or else Ekind (Entity (P)) not in Named_Kind
4648 Error_Attr_P ("prefix for % attribute must be named number");
4655 Src : Source_Buffer_Ptr;
4658 Expr := Original_Node (Expression (Parent (Entity (P))));
4660 if Nkind (Expr) = N_Op_Minus then
4662 Expr := Original_Node (Right_Opnd (Expr));
4667 if not Nkind_In (Expr, N_Integer_Literal, N_Real_Literal) then
4669 ("named number for % attribute must be simple literal", N);
4672 -- Build string literal corresponding to source literal text
4677 Store_String_Char (Get_Char_Code ('-'));
4681 Src := Source_Text (Get_Source_File_Index (S));
4683 while Src (S) /= ';' and then Src (S) /= ' ' loop
4684 Store_String_Char (Get_Char_Code (Src (S)));
4688 -- Now we rewrite the attribute with the string literal
4691 Make_String_Literal (Loc, End_String));
4695 end Universal_Literal_String;
4697 -------------------------
4698 -- Unrestricted_Access --
4699 -------------------------
4701 -- This is a GNAT specific attribute which is like Access except that
4702 -- all scope checks and checks for aliased views are omitted.
4704 when Attribute_Unrestricted_Access =>
4705 if Comes_From_Source (N) then
4706 Check_Restriction (No_Unchecked_Access, N);
4709 if Is_Entity_Name (P) then
4710 Set_Address_Taken (Entity (P));
4713 Analyze_Access_Attribute;
4719 when Attribute_Val => Val : declare
4722 Check_Discrete_Type;
4723 Resolve (E1, Any_Integer);
4724 Set_Etype (N, P_Base_Type);
4726 -- Note, we need a range check in general, but we wait for the
4727 -- Resolve call to do this, since we want to let Eval_Attribute
4728 -- have a chance to find an static illegality first!
4735 when Attribute_Valid =>
4738 -- Ignore check for object if we have a 'Valid reference generated
4739 -- by the expanded code, since in some cases valid checks can occur
4740 -- on items that are names, but are not objects (e.g. attributes).
4742 if Comes_From_Source (N) then
4743 Check_Object_Reference (P);
4746 if not Is_Scalar_Type (P_Type) then
4747 Error_Attr_P ("object for % attribute must be of scalar type");
4750 Set_Etype (N, Standard_Boolean);
4756 when Attribute_Value => Value :
4761 -- Case of enumeration type
4763 if Is_Enumeration_Type (P_Type) then
4764 Check_Restriction (No_Enumeration_Maps, N);
4766 -- Mark all enumeration literals as referenced, since the use of
4767 -- the Value attribute can implicitly reference any of the
4768 -- literals of the enumeration base type.
4771 Ent : Entity_Id := First_Literal (P_Base_Type);
4773 while Present (Ent) loop
4774 Set_Referenced (Ent);
4780 -- Set Etype before resolving expression because expansion of
4781 -- expression may require enclosing type. Note that the type
4782 -- returned by 'Value is the base type of the prefix type.
4784 Set_Etype (N, P_Base_Type);
4785 Validate_Non_Static_Attribute_Function_Call;
4792 when Attribute_Value_Size =>
4795 Check_Not_Incomplete_Type;
4796 Set_Etype (N, Universal_Integer);
4802 when Attribute_Version =>
4805 Set_Etype (N, RTE (RE_Version_String));
4811 when Attribute_Wchar_T_Size =>
4812 Standard_Attribute (Interfaces_Wchar_T_Size);
4818 when Attribute_Wide_Image => Wide_Image :
4821 Set_Etype (N, Standard_Wide_String);
4823 Resolve (E1, P_Base_Type);
4824 Validate_Non_Static_Attribute_Function_Call;
4827 ---------------------
4828 -- Wide_Wide_Image --
4829 ---------------------
4831 when Attribute_Wide_Wide_Image => Wide_Wide_Image :
4834 Set_Etype (N, Standard_Wide_Wide_String);
4836 Resolve (E1, P_Base_Type);
4837 Validate_Non_Static_Attribute_Function_Call;
4838 end Wide_Wide_Image;
4844 when Attribute_Wide_Value => Wide_Value :
4849 -- Set Etype before resolving expression because expansion
4850 -- of expression may require enclosing type.
4852 Set_Etype (N, P_Type);
4853 Validate_Non_Static_Attribute_Function_Call;
4856 ---------------------
4857 -- Wide_Wide_Value --
4858 ---------------------
4860 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
4865 -- Set Etype before resolving expression because expansion
4866 -- of expression may require enclosing type.
4868 Set_Etype (N, P_Type);
4869 Validate_Non_Static_Attribute_Function_Call;
4870 end Wide_Wide_Value;
4872 ---------------------
4873 -- Wide_Wide_Width --
4874 ---------------------
4876 when Attribute_Wide_Wide_Width =>
4879 Set_Etype (N, Universal_Integer);
4885 when Attribute_Wide_Width =>
4888 Set_Etype (N, Universal_Integer);
4894 when Attribute_Width =>
4897 Set_Etype (N, Universal_Integer);
4903 when Attribute_Word_Size =>
4904 Standard_Attribute (System_Word_Size);
4910 when Attribute_Write =>
4912 Check_Stream_Attribute (TSS_Stream_Write);
4913 Set_Etype (N, Standard_Void_Type);
4914 Resolve (N, Standard_Void_Type);
4918 -- All errors raise Bad_Attribute, so that we get out before any further
4919 -- damage occurs when an error is detected (for example, if we check for
4920 -- one attribute expression, and the check succeeds, we want to be able
4921 -- to proceed securely assuming that an expression is in fact present.
4923 -- Note: we set the attribute analyzed in this case to prevent any
4924 -- attempt at reanalysis which could generate spurious error msgs.
4927 when Bad_Attribute =>
4929 Set_Etype (N, Any_Type);
4931 end Analyze_Attribute;
4933 --------------------
4934 -- Eval_Attribute --
4935 --------------------
4937 procedure Eval_Attribute (N : Node_Id) is
4938 Loc : constant Source_Ptr := Sloc (N);
4939 Aname : constant Name_Id := Attribute_Name (N);
4940 Id : constant Attribute_Id := Get_Attribute_Id (Aname);
4941 P : constant Node_Id := Prefix (N);
4943 C_Type : constant Entity_Id := Etype (N);
4944 -- The type imposed by the context
4947 -- First expression, or Empty if none
4950 -- Second expression, or Empty if none
4952 P_Entity : Entity_Id;
4953 -- Entity denoted by prefix
4956 -- The type of the prefix
4958 P_Base_Type : Entity_Id;
4959 -- The base type of the prefix type
4961 P_Root_Type : Entity_Id;
4962 -- The root type of the prefix type
4965 -- True if the result is Static. This is set by the general processing
4966 -- to true if the prefix is static, and all expressions are static. It
4967 -- can be reset as processing continues for particular attributes
4969 Lo_Bound, Hi_Bound : Node_Id;
4970 -- Expressions for low and high bounds of type or array index referenced
4971 -- by First, Last, or Length attribute for array, set by Set_Bounds.
4974 -- Constraint error node used if we have an attribute reference has
4975 -- an argument that raises a constraint error. In this case we replace
4976 -- the attribute with a raise constraint_error node. This is important
4977 -- processing, since otherwise gigi might see an attribute which it is
4978 -- unprepared to deal with.
4980 procedure Check_Concurrent_Discriminant (Bound : Node_Id);
4981 -- If Bound is a reference to a discriminant of a task or protected type
4982 -- occurring within the object's body, rewrite attribute reference into
4983 -- a reference to the corresponding discriminal. Use for the expansion
4984 -- of checks against bounds of entry family index subtypes.
4986 procedure Check_Expressions;
4987 -- In case where the attribute is not foldable, the expressions, if
4988 -- any, of the attribute, are in a non-static context. This procedure
4989 -- performs the required additional checks.
4991 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean;
4992 -- Determines if the given type has compile time known bounds. Note
4993 -- that we enter the case statement even in cases where the prefix
4994 -- type does NOT have known bounds, so it is important to guard any
4995 -- attempt to evaluate both bounds with a call to this function.
4997 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint);
4998 -- This procedure is called when the attribute N has a non-static
4999 -- but compile time known value given by Val. It includes the
5000 -- necessary checks for out of range values.
5002 function Fore_Value return Nat;
5003 -- Computes the Fore value for the current attribute prefix, which is
5004 -- known to be a static fixed-point type. Used by Fore and Width.
5006 function Mantissa return Uint;
5007 -- Returns the Mantissa value for the prefix type
5009 procedure Set_Bounds;
5010 -- Used for First, Last and Length attributes applied to an array or
5011 -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low
5012 -- and high bound expressions for the index referenced by the attribute
5013 -- designator (i.e. the first index if no expression is present, and
5014 -- the N'th index if the value N is present as an expression). Also
5015 -- used for First and Last of scalar types. Static is reset to False
5016 -- if the type or index type is not statically constrained.
5018 function Statically_Denotes_Entity (N : Node_Id) return Boolean;
5019 -- Verify that the prefix of a potentially static array attribute
5020 -- satisfies the conditions of 4.9 (14).
5022 -----------------------------------
5023 -- Check_Concurrent_Discriminant --
5024 -----------------------------------
5026 procedure Check_Concurrent_Discriminant (Bound : Node_Id) is
5028 -- The concurrent (task or protected) type
5031 if Nkind (Bound) = N_Identifier
5032 and then Ekind (Entity (Bound)) = E_Discriminant
5033 and then Is_Concurrent_Record_Type (Scope (Entity (Bound)))
5035 Tsk := Corresponding_Concurrent_Type (Scope (Entity (Bound)));
5037 if In_Open_Scopes (Tsk) and then Has_Completion (Tsk) then
5039 -- Find discriminant of original concurrent type, and use
5040 -- its current discriminal, which is the renaming within
5041 -- the task/protected body.
5045 (Find_Body_Discriminal (Entity (Bound)), Loc));
5048 end Check_Concurrent_Discriminant;
5050 -----------------------
5051 -- Check_Expressions --
5052 -----------------------
5054 procedure Check_Expressions is
5058 while Present (E) loop
5059 Check_Non_Static_Context (E);
5062 end Check_Expressions;
5064 ----------------------------------
5065 -- Compile_Time_Known_Attribute --
5066 ----------------------------------
5068 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint) is
5069 T : constant Entity_Id := Etype (N);
5072 Fold_Uint (N, Val, False);
5074 -- Check that result is in bounds of the type if it is static
5076 if Is_In_Range (N, T, Assume_Valid => False) then
5079 elsif Is_Out_Of_Range (N, T) then
5080 Apply_Compile_Time_Constraint_Error
5081 (N, "value not in range of}?", CE_Range_Check_Failed);
5083 elsif not Range_Checks_Suppressed (T) then
5084 Enable_Range_Check (N);
5087 Set_Do_Range_Check (N, False);
5089 end Compile_Time_Known_Attribute;
5091 -------------------------------
5092 -- Compile_Time_Known_Bounds --
5093 -------------------------------
5095 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean is
5098 Compile_Time_Known_Value (Type_Low_Bound (Typ))
5100 Compile_Time_Known_Value (Type_High_Bound (Typ));
5101 end Compile_Time_Known_Bounds;
5107 -- Note that the Fore calculation is based on the actual values
5108 -- of the bounds, and does not take into account possible rounding.
5110 function Fore_Value return Nat is
5111 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
5112 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
5113 Small : constant Ureal := Small_Value (P_Type);
5114 Lo_Real : constant Ureal := Lo * Small;
5115 Hi_Real : constant Ureal := Hi * Small;
5120 -- Bounds are given in terms of small units, so first compute
5121 -- proper values as reals.
5123 T := UR_Max (abs Lo_Real, abs Hi_Real);
5126 -- Loop to compute proper value if more than one digit required
5128 while T >= Ureal_10 loop
5140 -- Table of mantissa values accessed by function Computed using
5143 -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1)
5145 -- where D is T'Digits (RM83 3.5.7)
5147 Mantissa_Value : constant array (Nat range 1 .. 40) of Nat := (
5189 function Mantissa return Uint is
5192 UI_From_Int (Mantissa_Value (UI_To_Int (Digits_Value (P_Type))));
5199 procedure Set_Bounds is
5205 -- For a string literal subtype, we have to construct the bounds.
5206 -- Valid Ada code never applies attributes to string literals, but
5207 -- it is convenient to allow the expander to generate attribute
5208 -- references of this type (e.g. First and Last applied to a string
5211 -- Note that the whole point of the E_String_Literal_Subtype is to
5212 -- avoid this construction of bounds, but the cases in which we
5213 -- have to materialize them are rare enough that we don't worry!
5215 -- The low bound is simply the low bound of the base type. The
5216 -- high bound is computed from the length of the string and this
5219 if Ekind (P_Type) = E_String_Literal_Subtype then
5220 Ityp := Etype (First_Index (Base_Type (P_Type)));
5221 Lo_Bound := Type_Low_Bound (Ityp);
5224 Make_Integer_Literal (Sloc (P),
5226 Expr_Value (Lo_Bound) + String_Literal_Length (P_Type) - 1);
5228 Set_Parent (Hi_Bound, P);
5229 Analyze_And_Resolve (Hi_Bound, Etype (Lo_Bound));
5232 -- For non-array case, just get bounds of scalar type
5234 elsif Is_Scalar_Type (P_Type) then
5237 -- For a fixed-point type, we must freeze to get the attributes
5238 -- of the fixed-point type set now so we can reference them.
5240 if Is_Fixed_Point_Type (P_Type)
5241 and then not Is_Frozen (Base_Type (P_Type))
5242 and then Compile_Time_Known_Value (Type_Low_Bound (P_Type))
5243 and then Compile_Time_Known_Value (Type_High_Bound (P_Type))
5245 Freeze_Fixed_Point_Type (Base_Type (P_Type));
5248 -- For array case, get type of proper index
5254 Ndim := UI_To_Int (Expr_Value (E1));
5257 Indx := First_Index (P_Type);
5258 for J in 1 .. Ndim - 1 loop
5262 -- If no index type, get out (some other error occurred, and
5263 -- we don't have enough information to complete the job!)
5271 Ityp := Etype (Indx);
5274 -- A discrete range in an index constraint is allowed to be a
5275 -- subtype indication. This is syntactically a pain, but should
5276 -- not propagate to the entity for the corresponding index subtype.
5277 -- After checking that the subtype indication is legal, the range
5278 -- of the subtype indication should be transfered to the entity.
5279 -- The attributes for the bounds should remain the simple retrievals
5280 -- that they are now.
5282 Lo_Bound := Type_Low_Bound (Ityp);
5283 Hi_Bound := Type_High_Bound (Ityp);
5285 if not Is_Static_Subtype (Ityp) then
5290 -------------------------------
5291 -- Statically_Denotes_Entity --
5292 -------------------------------
5294 function Statically_Denotes_Entity (N : Node_Id) return Boolean is
5298 if not Is_Entity_Name (N) then
5305 Nkind (Parent (E)) /= N_Object_Renaming_Declaration
5306 or else Statically_Denotes_Entity (Renamed_Object (E));
5307 end Statically_Denotes_Entity;
5309 -- Start of processing for Eval_Attribute
5312 -- No folding in spec expression that comes from source where the prefix
5313 -- is an unfrozen entity. This avoids premature folding in cases like:
5315 -- procedure DefExprAnal is
5316 -- type R is new Integer;
5317 -- procedure P (Arg : Integer := R'Size);
5318 -- for R'Size use 64;
5319 -- procedure P (Arg : Integer := R'Size) is
5321 -- Put_Line (Arg'Img);
5327 -- which should print 64 rather than 32. The exclusion of non-source
5328 -- constructs from this test comes from some internal usage in packed
5329 -- arrays, which otherwise fails, could use more analysis perhaps???
5331 -- We do however go ahead with generic actual types, otherwise we get
5332 -- some regressions, probably these types should be frozen anyway???
5334 if In_Spec_Expression
5335 and then Comes_From_Source (N)
5336 and then not (Is_Entity_Name (P)
5338 (Is_Frozen (Entity (P))
5339 or else (Is_Type (Entity (P))
5341 Is_Generic_Actual_Type (Entity (P)))))
5346 -- Acquire first two expressions (at the moment, no attributes take more
5347 -- than two expressions in any case).
5349 if Present (Expressions (N)) then
5350 E1 := First (Expressions (N));
5357 -- Special processing for Enabled attribute. This attribute has a very
5358 -- special prefix, and the easiest way to avoid lots of special checks
5359 -- to protect this special prefix from causing trouble is to deal with
5360 -- this attribute immediately and be done with it.
5362 if Id = Attribute_Enabled then
5364 -- We skip evaluation if the expander is not active. This is not just
5365 -- an optimization. It is of key importance that we not rewrite the
5366 -- attribute in a generic template, since we want to pick up the
5367 -- setting of the check in the instance, and testing expander active
5368 -- is as easy way of doing this as any.
5370 if Expander_Active then
5372 C : constant Check_Id := Get_Check_Id (Chars (P));
5377 if C in Predefined_Check_Id then
5378 R := Scope_Suppress (C);
5380 R := Is_Check_Suppressed (Empty, C);
5384 R := Is_Check_Suppressed (Entity (E1), C);
5388 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
5390 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
5398 -- Special processing for cases where the prefix is an object. For
5399 -- this purpose, a string literal counts as an object (attributes
5400 -- of string literals can only appear in generated code).
5402 if Is_Object_Reference (P) or else Nkind (P) = N_String_Literal then
5404 -- For Component_Size, the prefix is an array object, and we apply
5405 -- the attribute to the type of the object. This is allowed for
5406 -- both unconstrained and constrained arrays, since the bounds
5407 -- have no influence on the value of this attribute.
5409 if Id = Attribute_Component_Size then
5410 P_Entity := Etype (P);
5412 -- For First and Last, the prefix is an array object, and we apply
5413 -- the attribute to the type of the array, but we need a constrained
5414 -- type for this, so we use the actual subtype if available.
5416 elsif Id = Attribute_First
5420 Id = Attribute_Length
5423 AS : constant Entity_Id := Get_Actual_Subtype_If_Available (P);
5426 if Present (AS) and then Is_Constrained (AS) then
5429 -- If we have an unconstrained type we cannot fold
5437 -- For Size, give size of object if available, otherwise we
5438 -- cannot fold Size.
5440 elsif Id = Attribute_Size then
5441 if Is_Entity_Name (P)
5442 and then Known_Esize (Entity (P))
5444 Compile_Time_Known_Attribute (N, Esize (Entity (P)));
5452 -- For Alignment, give size of object if available, otherwise we
5453 -- cannot fold Alignment.
5455 elsif Id = Attribute_Alignment then
5456 if Is_Entity_Name (P)
5457 and then Known_Alignment (Entity (P))
5459 Fold_Uint (N, Alignment (Entity (P)), False);
5467 -- No other attributes for objects are folded
5474 -- Cases where P is not an object. Cannot do anything if P is
5475 -- not the name of an entity.
5477 elsif not Is_Entity_Name (P) then
5481 -- Otherwise get prefix entity
5484 P_Entity := Entity (P);
5487 -- At this stage P_Entity is the entity to which the attribute
5488 -- is to be applied. This is usually simply the entity of the
5489 -- prefix, except in some cases of attributes for objects, where
5490 -- as described above, we apply the attribute to the object type.
5492 -- First foldable possibility is a scalar or array type (RM 4.9(7))
5493 -- that is not generic (generic types are eliminated by RM 4.9(25)).
5494 -- Note we allow non-static non-generic types at this stage as further
5497 if Is_Type (P_Entity)
5498 and then (Is_Scalar_Type (P_Entity) or Is_Array_Type (P_Entity))
5499 and then (not Is_Generic_Type (P_Entity))
5503 -- Second foldable possibility is an array object (RM 4.9(8))
5505 elsif (Ekind (P_Entity) = E_Variable
5507 Ekind (P_Entity) = E_Constant)
5508 and then Is_Array_Type (Etype (P_Entity))
5509 and then (not Is_Generic_Type (Etype (P_Entity)))
5511 P_Type := Etype (P_Entity);
5513 -- If the entity is an array constant with an unconstrained nominal
5514 -- subtype then get the type from the initial value. If the value has
5515 -- been expanded into assignments, there is no expression and the
5516 -- attribute reference remains dynamic.
5518 -- We could do better here and retrieve the type ???
5520 if Ekind (P_Entity) = E_Constant
5521 and then not Is_Constrained (P_Type)
5523 if No (Constant_Value (P_Entity)) then
5526 P_Type := Etype (Constant_Value (P_Entity));
5530 -- Definite must be folded if the prefix is not a generic type,
5531 -- that is to say if we are within an instantiation. Same processing
5532 -- applies to the GNAT attributes Has_Discriminants, Type_Class,
5533 -- Has_Tagged_Value, and Unconstrained_Array.
5535 elsif (Id = Attribute_Definite
5537 Id = Attribute_Has_Access_Values
5539 Id = Attribute_Has_Discriminants
5541 Id = Attribute_Has_Tagged_Values
5543 Id = Attribute_Type_Class
5545 Id = Attribute_Unconstrained_Array
5547 Id = Attribute_Max_Alignment_For_Allocation)
5548 and then not Is_Generic_Type (P_Entity)
5552 -- We can fold 'Size applied to a type if the size is known (as happens
5553 -- for a size from an attribute definition clause). At this stage, this
5554 -- can happen only for types (e.g. record types) for which the size is
5555 -- always non-static. We exclude generic types from consideration (since
5556 -- they have bogus sizes set within templates).
5558 elsif Id = Attribute_Size
5559 and then Is_Type (P_Entity)
5560 and then (not Is_Generic_Type (P_Entity))
5561 and then Known_Static_RM_Size (P_Entity)
5563 Compile_Time_Known_Attribute (N, RM_Size (P_Entity));
5566 -- We can fold 'Alignment applied to a type if the alignment is known
5567 -- (as happens for an alignment from an attribute definition clause).
5568 -- At this stage, this can happen only for types (e.g. record
5569 -- types) for which the size is always non-static. We exclude
5570 -- generic types from consideration (since they have bogus
5571 -- sizes set within templates).
5573 elsif Id = Attribute_Alignment
5574 and then Is_Type (P_Entity)
5575 and then (not Is_Generic_Type (P_Entity))
5576 and then Known_Alignment (P_Entity)
5578 Compile_Time_Known_Attribute (N, Alignment (P_Entity));
5581 -- If this is an access attribute that is known to fail accessibility
5582 -- check, rewrite accordingly.
5584 elsif Attribute_Name (N) = Name_Access
5585 and then Raises_Constraint_Error (N)
5588 Make_Raise_Program_Error (Loc,
5589 Reason => PE_Accessibility_Check_Failed));
5590 Set_Etype (N, C_Type);
5593 -- No other cases are foldable (they certainly aren't static, and at
5594 -- the moment we don't try to fold any cases other than these three).
5601 -- If either attribute or the prefix is Any_Type, then propagate
5602 -- Any_Type to the result and don't do anything else at all.
5604 if P_Type = Any_Type
5605 or else (Present (E1) and then Etype (E1) = Any_Type)
5606 or else (Present (E2) and then Etype (E2) = Any_Type)
5608 Set_Etype (N, Any_Type);
5612 -- Scalar subtype case. We have not yet enforced the static requirement
5613 -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases
5614 -- of non-static attribute references (e.g. S'Digits for a non-static
5615 -- floating-point type, which we can compute at compile time).
5617 -- Note: this folding of non-static attributes is not simply a case of
5618 -- optimization. For many of the attributes affected, Gigi cannot handle
5619 -- the attribute and depends on the front end having folded them away.
5621 -- Note: although we don't require staticness at this stage, we do set
5622 -- the Static variable to record the staticness, for easy reference by
5623 -- those attributes where it matters (e.g. Succ and Pred), and also to
5624 -- be used to ensure that non-static folded things are not marked as
5625 -- being static (a check that is done right at the end).
5627 P_Root_Type := Root_Type (P_Type);
5628 P_Base_Type := Base_Type (P_Type);
5630 -- If the root type or base type is generic, then we cannot fold. This
5631 -- test is needed because subtypes of generic types are not always
5632 -- marked as being generic themselves (which seems odd???)
5634 if Is_Generic_Type (P_Root_Type)
5635 or else Is_Generic_Type (P_Base_Type)
5640 if Is_Scalar_Type (P_Type) then
5641 Static := Is_OK_Static_Subtype (P_Type);
5643 -- Array case. We enforce the constrained requirement of (RM 4.9(7-8))
5644 -- since we can't do anything with unconstrained arrays. In addition,
5645 -- only the First, Last and Length attributes are possibly static.
5647 -- Definite, Has_Access_Values, Has_Discriminants, Has_Tagged_Values,
5648 -- Type_Class, and Unconstrained_Array are again exceptions, because
5649 -- they apply as well to unconstrained types.
5651 -- In addition Component_Size is an exception since it is possibly
5652 -- foldable, even though it is never static, and it does apply to
5653 -- unconstrained arrays. Furthermore, it is essential to fold this
5654 -- in the packed case, since otherwise the value will be incorrect.
5656 elsif Id = Attribute_Definite
5658 Id = Attribute_Has_Access_Values
5660 Id = Attribute_Has_Discriminants
5662 Id = Attribute_Has_Tagged_Values
5664 Id = Attribute_Type_Class
5666 Id = Attribute_Unconstrained_Array
5668 Id = Attribute_Component_Size
5672 elsif Id /= Attribute_Max_Alignment_For_Allocation then
5673 if not Is_Constrained (P_Type)
5674 or else (Id /= Attribute_First and then
5675 Id /= Attribute_Last and then
5676 Id /= Attribute_Length)
5682 -- The rules in (RM 4.9(7,8)) require a static array, but as in the
5683 -- scalar case, we hold off on enforcing staticness, since there are
5684 -- cases which we can fold at compile time even though they are not
5685 -- static (e.g. 'Length applied to a static index, even though other
5686 -- non-static indexes make the array type non-static). This is only
5687 -- an optimization, but it falls out essentially free, so why not.
5688 -- Again we compute the variable Static for easy reference later
5689 -- (note that no array attributes are static in Ada 83).
5691 -- We also need to set Static properly for subsequent legality checks
5692 -- which might otherwise accept non-static constants in contexts
5693 -- where they are not legal.
5695 Static := Ada_Version >= Ada_95
5696 and then Statically_Denotes_Entity (P);
5702 N := First_Index (P_Type);
5704 -- The expression is static if the array type is constrained
5705 -- by given bounds, and not by an initial expression. Constant
5706 -- strings are static in any case.
5708 if Root_Type (P_Type) /= Standard_String then
5710 Static and then not Is_Constr_Subt_For_U_Nominal (P_Type);
5713 while Present (N) loop
5714 Static := Static and then Is_Static_Subtype (Etype (N));
5716 -- If however the index type is generic, or derived from
5717 -- one, attributes cannot be folded.
5719 if Is_Generic_Type (Root_Type (Etype (N)))
5720 and then Id /= Attribute_Component_Size
5730 -- Check any expressions that are present. Note that these expressions,
5731 -- depending on the particular attribute type, are either part of the
5732 -- attribute designator, or they are arguments in a case where the
5733 -- attribute reference returns a function. In the latter case, the
5734 -- rule in (RM 4.9(22)) applies and in particular requires the type
5735 -- of the expressions to be scalar in order for the attribute to be
5736 -- considered to be static.
5743 while Present (E) loop
5745 -- If expression is not static, then the attribute reference
5746 -- result certainly cannot be static.
5748 if not Is_Static_Expression (E) then
5752 -- If the result is not known at compile time, or is not of
5753 -- a scalar type, then the result is definitely not static,
5754 -- so we can quit now.
5756 if not Compile_Time_Known_Value (E)
5757 or else not Is_Scalar_Type (Etype (E))
5759 -- An odd special case, if this is a Pos attribute, this
5760 -- is where we need to apply a range check since it does
5761 -- not get done anywhere else.
5763 if Id = Attribute_Pos then
5764 if Is_Integer_Type (Etype (E)) then
5765 Apply_Range_Check (E, Etype (N));
5772 -- If the expression raises a constraint error, then so does
5773 -- the attribute reference. We keep going in this case because
5774 -- we are still interested in whether the attribute reference
5775 -- is static even if it is not static.
5777 elsif Raises_Constraint_Error (E) then
5778 Set_Raises_Constraint_Error (N);
5784 if Raises_Constraint_Error (Prefix (N)) then
5789 -- Deal with the case of a static attribute reference that raises
5790 -- constraint error. The Raises_Constraint_Error flag will already
5791 -- have been set, and the Static flag shows whether the attribute
5792 -- reference is static. In any case we certainly can't fold such an
5793 -- attribute reference.
5795 -- Note that the rewriting of the attribute node with the constraint
5796 -- error node is essential in this case, because otherwise Gigi might
5797 -- blow up on one of the attributes it never expects to see.
5799 -- The constraint_error node must have the type imposed by the context,
5800 -- to avoid spurious errors in the enclosing expression.
5802 if Raises_Constraint_Error (N) then
5804 Make_Raise_Constraint_Error (Sloc (N),
5805 Reason => CE_Range_Check_Failed);
5806 Set_Etype (CE_Node, Etype (N));
5807 Set_Raises_Constraint_Error (CE_Node);
5809 Rewrite (N, Relocate_Node (CE_Node));
5810 Set_Is_Static_Expression (N, Static);
5814 -- At this point we have a potentially foldable attribute reference.
5815 -- If Static is set, then the attribute reference definitely obeys
5816 -- the requirements in (RM 4.9(7,8,22)), and it definitely can be
5817 -- folded. If Static is not set, then the attribute may or may not
5818 -- be foldable, and the individual attribute processing routines
5819 -- test Static as required in cases where it makes a difference.
5821 -- In the case where Static is not set, we do know that all the
5822 -- expressions present are at least known at compile time (we
5823 -- assumed above that if this was not the case, then there was
5824 -- no hope of static evaluation). However, we did not require
5825 -- that the bounds of the prefix type be compile time known,
5826 -- let alone static). That's because there are many attributes
5827 -- that can be computed at compile time on non-static subtypes,
5828 -- even though such references are not static expressions.
5836 when Attribute_Adjacent =>
5839 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
5845 when Attribute_Aft =>
5846 Fold_Uint (N, Aft_Value (P_Type), True);
5852 when Attribute_Alignment => Alignment_Block : declare
5853 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
5856 -- Fold if alignment is set and not otherwise
5858 if Known_Alignment (P_TypeA) then
5859 Fold_Uint (N, Alignment (P_TypeA), Is_Discrete_Type (P_TypeA));
5861 end Alignment_Block;
5867 -- Can only be folded in No_Ast_Handler case
5869 when Attribute_AST_Entry =>
5870 if not Is_AST_Entry (P_Entity) then
5872 New_Occurrence_Of (RTE (RE_No_AST_Handler), Loc));
5881 -- Bit can never be folded
5883 when Attribute_Bit =>
5890 -- Body_version can never be static
5892 when Attribute_Body_Version =>
5899 when Attribute_Ceiling =>
5901 Eval_Fat.Ceiling (P_Root_Type, Expr_Value_R (E1)), Static);
5903 --------------------
5904 -- Component_Size --
5905 --------------------
5907 when Attribute_Component_Size =>
5908 if Known_Static_Component_Size (P_Type) then
5909 Fold_Uint (N, Component_Size (P_Type), False);
5916 when Attribute_Compose =>
5919 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)),
5926 -- Constrained is never folded for now, there may be cases that
5927 -- could be handled at compile time. To be looked at later.
5929 when Attribute_Constrained =>
5936 when Attribute_Copy_Sign =>
5939 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
5945 when Attribute_Delta =>
5946 Fold_Ureal (N, Delta_Value (P_Type), True);
5952 when Attribute_Definite =>
5953 Rewrite (N, New_Occurrence_Of (
5954 Boolean_Literals (not Is_Indefinite_Subtype (P_Entity)), Loc));
5955 Analyze_And_Resolve (N, Standard_Boolean);
5961 when Attribute_Denorm =>
5963 (N, UI_From_Int (Boolean'Pos (Denorm_On_Target)), True);
5969 when Attribute_Digits =>
5970 Fold_Uint (N, Digits_Value (P_Type), True);
5976 when Attribute_Emax =>
5978 -- Ada 83 attribute is defined as (RM83 3.5.8)
5980 -- T'Emax = 4 * T'Mantissa
5982 Fold_Uint (N, 4 * Mantissa, True);
5988 when Attribute_Enum_Rep =>
5990 -- For an enumeration type with a non-standard representation use
5991 -- the Enumeration_Rep field of the proper constant. Note that this
5992 -- will not work for types Character/Wide_[Wide-]Character, since no
5993 -- real entities are created for the enumeration literals, but that
5994 -- does not matter since these two types do not have non-standard
5995 -- representations anyway.
5997 if Is_Enumeration_Type (P_Type)
5998 and then Has_Non_Standard_Rep (P_Type)
6000 Fold_Uint (N, Enumeration_Rep (Expr_Value_E (E1)), Static);
6002 -- For enumeration types with standard representations and all
6003 -- other cases (i.e. all integer and modular types), Enum_Rep
6004 -- is equivalent to Pos.
6007 Fold_Uint (N, Expr_Value (E1), Static);
6014 when Attribute_Enum_Val => Enum_Val : declare
6018 -- We have something like Enum_Type'Enum_Val (23), so search for a
6019 -- corresponding value in the list of Enum_Rep values for the type.
6021 Lit := First_Literal (P_Base_Type);
6023 if Enumeration_Rep (Lit) = Expr_Value (E1) then
6024 Fold_Uint (N, Enumeration_Pos (Lit), Static);
6031 Apply_Compile_Time_Constraint_Error
6032 (N, "no representation value matches",
6033 CE_Range_Check_Failed,
6034 Warn => not Static);
6044 when Attribute_Epsilon =>
6046 -- Ada 83 attribute is defined as (RM83 3.5.8)
6048 -- T'Epsilon = 2.0**(1 - T'Mantissa)
6050 Fold_Ureal (N, Ureal_2 ** (1 - Mantissa), True);
6056 when Attribute_Exponent =>
6058 Eval_Fat.Exponent (P_Root_Type, Expr_Value_R (E1)), Static);
6064 when Attribute_First => First_Attr :
6068 if Compile_Time_Known_Value (Lo_Bound) then
6069 if Is_Real_Type (P_Type) then
6070 Fold_Ureal (N, Expr_Value_R (Lo_Bound), Static);
6072 Fold_Uint (N, Expr_Value (Lo_Bound), Static);
6076 Check_Concurrent_Discriminant (Lo_Bound);
6084 when Attribute_Fixed_Value =>
6091 when Attribute_Floor =>
6093 Eval_Fat.Floor (P_Root_Type, Expr_Value_R (E1)), Static);
6099 when Attribute_Fore =>
6100 if Compile_Time_Known_Bounds (P_Type) then
6101 Fold_Uint (N, UI_From_Int (Fore_Value), Static);
6108 when Attribute_Fraction =>
6110 Eval_Fat.Fraction (P_Root_Type, Expr_Value_R (E1)), Static);
6112 -----------------------
6113 -- Has_Access_Values --
6114 -----------------------
6116 when Attribute_Has_Access_Values =>
6117 Rewrite (N, New_Occurrence_Of
6118 (Boolean_Literals (Has_Access_Values (P_Root_Type)), Loc));
6119 Analyze_And_Resolve (N, Standard_Boolean);
6121 -----------------------
6122 -- Has_Discriminants --
6123 -----------------------
6125 when Attribute_Has_Discriminants =>
6126 Rewrite (N, New_Occurrence_Of (
6127 Boolean_Literals (Has_Discriminants (P_Entity)), Loc));
6128 Analyze_And_Resolve (N, Standard_Boolean);
6130 -----------------------
6131 -- Has_Tagged_Values --
6132 -----------------------
6134 when Attribute_Has_Tagged_Values =>
6135 Rewrite (N, New_Occurrence_Of
6136 (Boolean_Literals (Has_Tagged_Component (P_Root_Type)), Loc));
6137 Analyze_And_Resolve (N, Standard_Boolean);
6143 when Attribute_Identity =>
6150 -- Image is a scalar attribute, but is never static, because it is
6151 -- not a static function (having a non-scalar argument (RM 4.9(22))
6152 -- However, we can constant-fold the image of an enumeration literal
6153 -- if names are available.
6155 when Attribute_Image =>
6156 if Is_Entity_Name (E1)
6157 and then Ekind (Entity (E1)) = E_Enumeration_Literal
6158 and then not Discard_Names (First_Subtype (Etype (E1)))
6159 and then not Global_Discard_Names
6162 Lit : constant Entity_Id := Entity (E1);
6166 Get_Unqualified_Decoded_Name_String (Chars (Lit));
6167 Set_Casing (All_Upper_Case);
6168 Store_String_Chars (Name_Buffer (1 .. Name_Len));
6170 Rewrite (N, Make_String_Literal (Loc, Strval => Str));
6171 Analyze_And_Resolve (N, Standard_String);
6172 Set_Is_Static_Expression (N, False);
6180 -- Img is a scalar attribute, but is never static, because it is
6181 -- not a static function (having a non-scalar argument (RM 4.9(22))
6183 when Attribute_Img =>
6190 -- We never try to fold Integer_Value (though perhaps we could???)
6192 when Attribute_Integer_Value =>
6199 -- Invalid_Value is a scalar attribute that is never static, because
6200 -- the value is by design out of range.
6202 when Attribute_Invalid_Value =>
6209 when Attribute_Large =>
6211 -- For fixed-point, we use the identity:
6213 -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small
6215 if Is_Fixed_Point_Type (P_Type) then
6217 Make_Op_Multiply (Loc,
6219 Make_Op_Subtract (Loc,
6223 Make_Real_Literal (Loc, Ureal_2),
6225 Make_Attribute_Reference (Loc,
6227 Attribute_Name => Name_Mantissa)),
6228 Right_Opnd => Make_Real_Literal (Loc, Ureal_1)),
6231 Make_Real_Literal (Loc, Small_Value (Entity (P)))));
6233 Analyze_And_Resolve (N, C_Type);
6235 -- Floating-point (Ada 83 compatibility)
6238 -- Ada 83 attribute is defined as (RM83 3.5.8)
6240 -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa))
6244 -- T'Emax = 4 * T'Mantissa
6247 Ureal_2 ** (4 * Mantissa) * (Ureal_1 - Ureal_2 ** (-Mantissa)),
6255 when Attribute_Last => Last :
6259 if Compile_Time_Known_Value (Hi_Bound) then
6260 if Is_Real_Type (P_Type) then
6261 Fold_Ureal (N, Expr_Value_R (Hi_Bound), Static);
6263 Fold_Uint (N, Expr_Value (Hi_Bound), Static);
6267 Check_Concurrent_Discriminant (Hi_Bound);
6275 when Attribute_Leading_Part =>
6277 Eval_Fat.Leading_Part
6278 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
6284 when Attribute_Length => Length : declare
6288 -- If any index type is a formal type, or derived from one, the
6289 -- bounds are not static. Treating them as static can produce
6290 -- spurious warnings or improper constant folding.
6292 Ind := First_Index (P_Type);
6293 while Present (Ind) loop
6294 if Is_Generic_Type (Root_Type (Etype (Ind))) then
6303 -- For two compile time values, we can compute length
6305 if Compile_Time_Known_Value (Lo_Bound)
6306 and then Compile_Time_Known_Value (Hi_Bound)
6309 UI_Max (0, 1 + (Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound))),
6313 -- One more case is where Hi_Bound and Lo_Bound are compile-time
6314 -- comparable, and we can figure out the difference between them.
6317 Diff : aliased Uint;
6321 Compile_Time_Compare
6322 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
6325 Fold_Uint (N, Uint_1, False);
6328 Fold_Uint (N, Uint_0, False);
6331 if Diff /= No_Uint then
6332 Fold_Uint (N, Diff + 1, False);
6345 when Attribute_Machine =>
6348 (P_Root_Type, Expr_Value_R (E1), Eval_Fat.Round, N),
6355 when Attribute_Machine_Emax =>
6356 Fold_Uint (N, Machine_Emax_Value (P_Type), Static);
6362 when Attribute_Machine_Emin =>
6363 Fold_Uint (N, Machine_Emin_Value (P_Type), Static);
6365 ----------------------
6366 -- Machine_Mantissa --
6367 ----------------------
6369 when Attribute_Machine_Mantissa =>
6370 Fold_Uint (N, Machine_Mantissa_Value (P_Type), Static);
6372 -----------------------
6373 -- Machine_Overflows --
6374 -----------------------
6376 when Attribute_Machine_Overflows =>
6378 -- Always true for fixed-point
6380 if Is_Fixed_Point_Type (P_Type) then
6381 Fold_Uint (N, True_Value, True);
6383 -- Floating point case
6387 UI_From_Int (Boolean'Pos (Machine_Overflows_On_Target)),
6395 when Attribute_Machine_Radix =>
6396 if Is_Fixed_Point_Type (P_Type) then
6397 if Is_Decimal_Fixed_Point_Type (P_Type)
6398 and then Machine_Radix_10 (P_Type)
6400 Fold_Uint (N, Uint_10, True);
6402 Fold_Uint (N, Uint_2, True);
6405 -- All floating-point type always have radix 2
6408 Fold_Uint (N, Uint_2, True);
6411 ----------------------
6412 -- Machine_Rounding --
6413 ----------------------
6415 -- Note: for the folding case, it is fine to treat Machine_Rounding
6416 -- exactly the same way as Rounding, since this is one of the allowed
6417 -- behaviors, and performance is not an issue here. It might be a bit
6418 -- better to give the same result as it would give at run time, even
6419 -- though the non-determinism is certainly permitted.
6421 when Attribute_Machine_Rounding =>
6423 Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static);
6425 --------------------
6426 -- Machine_Rounds --
6427 --------------------
6429 when Attribute_Machine_Rounds =>
6431 -- Always False for fixed-point
6433 if Is_Fixed_Point_Type (P_Type) then
6434 Fold_Uint (N, False_Value, True);
6436 -- Else yield proper floating-point result
6440 (N, UI_From_Int (Boolean'Pos (Machine_Rounds_On_Target)), True);
6447 -- Note: Machine_Size is identical to Object_Size
6449 when Attribute_Machine_Size => Machine_Size : declare
6450 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6453 if Known_Esize (P_TypeA) then
6454 Fold_Uint (N, Esize (P_TypeA), True);
6462 when Attribute_Mantissa =>
6464 -- Fixed-point mantissa
6466 if Is_Fixed_Point_Type (P_Type) then
6468 -- Compile time foldable case
6470 if Compile_Time_Known_Value (Type_Low_Bound (P_Type))
6472 Compile_Time_Known_Value (Type_High_Bound (P_Type))
6474 -- The calculation of the obsolete Ada 83 attribute Mantissa
6475 -- is annoying, because of AI00143, quoted here:
6477 -- !question 84-01-10
6479 -- Consider the model numbers for F:
6481 -- type F is delta 1.0 range -7.0 .. 8.0;
6483 -- The wording requires that F'MANTISSA be the SMALLEST
6484 -- integer number for which each bound of the specified
6485 -- range is either a model number or lies at most small
6486 -- distant from a model number. This means F'MANTISSA
6487 -- is required to be 3 since the range -7.0 .. 7.0 fits
6488 -- in 3 signed bits, and 8 is "at most" 1.0 from a model
6489 -- number, namely, 7. Is this analysis correct? Note that
6490 -- this implies the upper bound of the range is not
6491 -- represented as a model number.
6493 -- !response 84-03-17
6495 -- The analysis is correct. The upper and lower bounds for
6496 -- a fixed point type can lie outside the range of model
6507 LBound := Expr_Value_R (Type_Low_Bound (P_Type));
6508 UBound := Expr_Value_R (Type_High_Bound (P_Type));
6509 Bound := UR_Max (UR_Abs (LBound), UR_Abs (UBound));
6510 Max_Man := UR_Trunc (Bound / Small_Value (P_Type));
6512 -- If the Bound is exactly a model number, i.e. a multiple
6513 -- of Small, then we back it off by one to get the integer
6514 -- value that must be representable.
6516 if Small_Value (P_Type) * Max_Man = Bound then
6517 Max_Man := Max_Man - 1;
6520 -- Now find corresponding size = Mantissa value
6523 while 2 ** Siz < Max_Man loop
6527 Fold_Uint (N, Siz, True);
6531 -- The case of dynamic bounds cannot be evaluated at compile
6532 -- time. Instead we use a runtime routine (see Exp_Attr).
6537 -- Floating-point Mantissa
6540 Fold_Uint (N, Mantissa, True);
6547 when Attribute_Max => Max :
6549 if Is_Real_Type (P_Type) then
6551 (N, UR_Max (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6553 Fold_Uint (N, UI_Max (Expr_Value (E1), Expr_Value (E2)), Static);
6557 ----------------------------------
6558 -- Max_Alignment_For_Allocation --
6559 ----------------------------------
6561 -- Max_Alignment_For_Allocation is usually the Alignment. However,
6562 -- arrays are allocated with dope, so we need to take into account both
6563 -- the alignment of the array, which comes from the component alignment,
6564 -- and the alignment of the dope. Also, if the alignment is unknown, we
6565 -- use the max (it's OK to be pessimistic).
6567 when Attribute_Max_Alignment_For_Allocation =>
6569 A : Uint := UI_From_Int (Ttypes.Maximum_Alignment);
6571 if Known_Alignment (P_Type) and then
6572 (not Is_Array_Type (P_Type) or else Alignment (P_Type) > A)
6574 A := Alignment (P_Type);
6577 Fold_Uint (N, A, Static);
6580 ----------------------------------
6581 -- Max_Size_In_Storage_Elements --
6582 ----------------------------------
6584 -- Max_Size_In_Storage_Elements is simply the Size rounded up to a
6585 -- Storage_Unit boundary. We can fold any cases for which the size
6586 -- is known by the front end.
6588 when Attribute_Max_Size_In_Storage_Elements =>
6589 if Known_Esize (P_Type) then
6591 (Esize (P_Type) + System_Storage_Unit - 1) /
6592 System_Storage_Unit,
6596 --------------------
6597 -- Mechanism_Code --
6598 --------------------
6600 when Attribute_Mechanism_Code =>
6604 Mech : Mechanism_Type;
6608 Mech := Mechanism (P_Entity);
6611 Val := UI_To_Int (Expr_Value (E1));
6613 Formal := First_Formal (P_Entity);
6614 for J in 1 .. Val - 1 loop
6615 Next_Formal (Formal);
6617 Mech := Mechanism (Formal);
6621 Fold_Uint (N, UI_From_Int (Int (-Mech)), True);
6629 when Attribute_Min => Min :
6631 if Is_Real_Type (P_Type) then
6633 (N, UR_Min (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6636 (N, UI_Min (Expr_Value (E1), Expr_Value (E2)), Static);
6644 when Attribute_Mod =>
6646 (N, UI_Mod (Expr_Value (E1), Modulus (P_Base_Type)), Static);
6652 when Attribute_Model =>
6654 Eval_Fat.Model (P_Root_Type, Expr_Value_R (E1)), Static);
6660 when Attribute_Model_Emin =>
6661 Fold_Uint (N, Model_Emin_Value (P_Base_Type), Static);
6667 when Attribute_Model_Epsilon =>
6668 Fold_Ureal (N, Model_Epsilon_Value (P_Base_Type), Static);
6670 --------------------
6671 -- Model_Mantissa --
6672 --------------------
6674 when Attribute_Model_Mantissa =>
6675 Fold_Uint (N, Model_Mantissa_Value (P_Base_Type), Static);
6681 when Attribute_Model_Small =>
6682 Fold_Ureal (N, Model_Small_Value (P_Base_Type), Static);
6688 when Attribute_Modulus =>
6689 Fold_Uint (N, Modulus (P_Type), True);
6691 --------------------
6692 -- Null_Parameter --
6693 --------------------
6695 -- Cannot fold, we know the value sort of, but the whole point is
6696 -- that there is no way to talk about this imaginary value except
6697 -- by using the attribute, so we leave it the way it is.
6699 when Attribute_Null_Parameter =>
6706 -- The Object_Size attribute for a type returns the Esize of the
6707 -- type and can be folded if this value is known.
6709 when Attribute_Object_Size => Object_Size : declare
6710 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6713 if Known_Esize (P_TypeA) then
6714 Fold_Uint (N, Esize (P_TypeA), True);
6718 -------------------------
6719 -- Passed_By_Reference --
6720 -------------------------
6722 -- Scalar types are never passed by reference
6724 when Attribute_Passed_By_Reference =>
6725 Fold_Uint (N, False_Value, True);
6731 when Attribute_Pos =>
6732 Fold_Uint (N, Expr_Value (E1), True);
6738 when Attribute_Pred => Pred :
6740 -- Floating-point case
6742 if Is_Floating_Point_Type (P_Type) then
6744 Eval_Fat.Pred (P_Root_Type, Expr_Value_R (E1)), Static);
6748 elsif Is_Fixed_Point_Type (P_Type) then
6750 Expr_Value_R (E1) - Small_Value (P_Type), True);
6752 -- Modular integer case (wraps)
6754 elsif Is_Modular_Integer_Type (P_Type) then
6755 Fold_Uint (N, (Expr_Value (E1) - 1) mod Modulus (P_Type), Static);
6757 -- Other scalar cases
6760 pragma Assert (Is_Scalar_Type (P_Type));
6762 if Is_Enumeration_Type (P_Type)
6763 and then Expr_Value (E1) =
6764 Expr_Value (Type_Low_Bound (P_Base_Type))
6766 Apply_Compile_Time_Constraint_Error
6767 (N, "Pred of `&''First`",
6768 CE_Overflow_Check_Failed,
6770 Warn => not Static);
6776 Fold_Uint (N, Expr_Value (E1) - 1, Static);
6784 -- No processing required, because by this stage, Range has been
6785 -- replaced by First .. Last, so this branch can never be taken.
6787 when Attribute_Range =>
6788 raise Program_Error;
6794 when Attribute_Range_Length =>
6797 -- Can fold if both bounds are compile time known
6799 if Compile_Time_Known_Value (Hi_Bound)
6800 and then Compile_Time_Known_Value (Lo_Bound)
6804 (0, Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound) + 1),
6808 -- One more case is where Hi_Bound and Lo_Bound are compile-time
6809 -- comparable, and we can figure out the difference between them.
6812 Diff : aliased Uint;
6816 Compile_Time_Compare
6817 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
6820 Fold_Uint (N, Uint_1, False);
6823 Fold_Uint (N, Uint_0, False);
6826 if Diff /= No_Uint then
6827 Fold_Uint (N, Diff + 1, False);
6839 when Attribute_Ref =>
6840 Fold_Uint (N, Expr_Value (E1), True);
6846 when Attribute_Remainder => Remainder : declare
6847 X : constant Ureal := Expr_Value_R (E1);
6848 Y : constant Ureal := Expr_Value_R (E2);
6851 if UR_Is_Zero (Y) then
6852 Apply_Compile_Time_Constraint_Error
6853 (N, "division by zero in Remainder",
6854 CE_Overflow_Check_Failed,
6855 Warn => not Static);
6861 Fold_Ureal (N, Eval_Fat.Remainder (P_Root_Type, X, Y), Static);
6868 when Attribute_Round => Round :
6874 -- First we get the (exact result) in units of small
6876 Sr := Expr_Value_R (E1) / Small_Value (C_Type);
6878 -- Now round that exactly to an integer
6880 Si := UR_To_Uint (Sr);
6882 -- Finally the result is obtained by converting back to real
6884 Fold_Ureal (N, Si * Small_Value (C_Type), Static);
6891 when Attribute_Rounding =>
6893 Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static);
6899 when Attribute_Safe_Emax =>
6900 Fold_Uint (N, Safe_Emax_Value (P_Type), Static);
6906 when Attribute_Safe_First =>
6907 Fold_Ureal (N, Safe_First_Value (P_Type), Static);
6913 when Attribute_Safe_Large =>
6914 if Is_Fixed_Point_Type (P_Type) then
6916 (N, Expr_Value_R (Type_High_Bound (P_Base_Type)), Static);
6918 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
6925 when Attribute_Safe_Last =>
6926 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
6932 when Attribute_Safe_Small =>
6934 -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant
6935 -- for fixed-point, since is the same as Small, but we implement
6936 -- it for backwards compatibility.
6938 if Is_Fixed_Point_Type (P_Type) then
6939 Fold_Ureal (N, Small_Value (P_Type), Static);
6941 -- Ada 83 Safe_Small for floating-point cases
6944 Fold_Ureal (N, Model_Small_Value (P_Type), Static);
6951 when Attribute_Scale =>
6952 Fold_Uint (N, Scale_Value (P_Type), True);
6958 when Attribute_Scaling =>
6961 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
6967 when Attribute_Signed_Zeros =>
6969 (N, UI_From_Int (Boolean'Pos (Signed_Zeros_On_Target)), Static);
6975 -- Size attribute returns the RM size. All scalar types can be folded,
6976 -- as well as any types for which the size is known by the front end,
6977 -- including any type for which a size attribute is specified.
6979 when Attribute_Size | Attribute_VADS_Size => Size : declare
6980 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6983 if RM_Size (P_TypeA) /= Uint_0 then
6987 if Id = Attribute_VADS_Size or else Use_VADS_Size then
6989 S : constant Node_Id := Size_Clause (P_TypeA);
6992 -- If a size clause applies, then use the size from it.
6993 -- This is one of the rare cases where we can use the
6994 -- Size_Clause field for a subtype when Has_Size_Clause
6995 -- is False. Consider:
6997 -- type x is range 1 .. 64;
6998 -- for x'size use 12;
6999 -- subtype y is x range 0 .. 3;
7001 -- Here y has a size clause inherited from x, but normally
7002 -- it does not apply, and y'size is 2. However, y'VADS_Size
7003 -- is indeed 12 and not 2.
7006 and then Is_OK_Static_Expression (Expression (S))
7008 Fold_Uint (N, Expr_Value (Expression (S)), True);
7010 -- If no size is specified, then we simply use the object
7011 -- size in the VADS_Size case (e.g. Natural'Size is equal
7012 -- to Integer'Size, not one less).
7015 Fold_Uint (N, Esize (P_TypeA), True);
7019 -- Normal case (Size) in which case we want the RM_Size
7024 Static and then Is_Discrete_Type (P_TypeA));
7033 when Attribute_Small =>
7035 -- The floating-point case is present only for Ada 83 compatibility.
7036 -- Note that strictly this is an illegal addition, since we are
7037 -- extending an Ada 95 defined attribute, but we anticipate an
7038 -- ARG ruling that will permit this.
7040 if Is_Floating_Point_Type (P_Type) then
7042 -- Ada 83 attribute is defined as (RM83 3.5.8)
7044 -- T'Small = 2.0**(-T'Emax - 1)
7048 -- T'Emax = 4 * T'Mantissa
7050 Fold_Ureal (N, Ureal_2 ** ((-(4 * Mantissa)) - 1), Static);
7052 -- Normal Ada 95 fixed-point case
7055 Fold_Ureal (N, Small_Value (P_Type), True);
7062 when Attribute_Stream_Size =>
7069 when Attribute_Succ => Succ :
7071 -- Floating-point case
7073 if Is_Floating_Point_Type (P_Type) then
7075 Eval_Fat.Succ (P_Root_Type, Expr_Value_R (E1)), Static);
7079 elsif Is_Fixed_Point_Type (P_Type) then
7081 Expr_Value_R (E1) + Small_Value (P_Type), Static);
7083 -- Modular integer case (wraps)
7085 elsif Is_Modular_Integer_Type (P_Type) then
7086 Fold_Uint (N, (Expr_Value (E1) + 1) mod Modulus (P_Type), Static);
7088 -- Other scalar cases
7091 pragma Assert (Is_Scalar_Type (P_Type));
7093 if Is_Enumeration_Type (P_Type)
7094 and then Expr_Value (E1) =
7095 Expr_Value (Type_High_Bound (P_Base_Type))
7097 Apply_Compile_Time_Constraint_Error
7098 (N, "Succ of `&''Last`",
7099 CE_Overflow_Check_Failed,
7101 Warn => not Static);
7106 Fold_Uint (N, Expr_Value (E1) + 1, Static);
7115 when Attribute_Truncation =>
7117 Eval_Fat.Truncation (P_Root_Type, Expr_Value_R (E1)), Static);
7123 when Attribute_Type_Class => Type_Class : declare
7124 Typ : constant Entity_Id := Underlying_Type (P_Base_Type);
7128 if Is_Descendent_Of_Address (Typ) then
7129 Id := RE_Type_Class_Address;
7131 elsif Is_Enumeration_Type (Typ) then
7132 Id := RE_Type_Class_Enumeration;
7134 elsif Is_Integer_Type (Typ) then
7135 Id := RE_Type_Class_Integer;
7137 elsif Is_Fixed_Point_Type (Typ) then
7138 Id := RE_Type_Class_Fixed_Point;
7140 elsif Is_Floating_Point_Type (Typ) then
7141 Id := RE_Type_Class_Floating_Point;
7143 elsif Is_Array_Type (Typ) then
7144 Id := RE_Type_Class_Array;
7146 elsif Is_Record_Type (Typ) then
7147 Id := RE_Type_Class_Record;
7149 elsif Is_Access_Type (Typ) then
7150 Id := RE_Type_Class_Access;
7152 elsif Is_Enumeration_Type (Typ) then
7153 Id := RE_Type_Class_Enumeration;
7155 elsif Is_Task_Type (Typ) then
7156 Id := RE_Type_Class_Task;
7158 -- We treat protected types like task types. It would make more
7159 -- sense to have another enumeration value, but after all the
7160 -- whole point of this feature is to be exactly DEC compatible,
7161 -- and changing the type Type_Class would not meet this requirement.
7163 elsif Is_Protected_Type (Typ) then
7164 Id := RE_Type_Class_Task;
7166 -- Not clear if there are any other possibilities, but if there
7167 -- are, then we will treat them as the address case.
7170 Id := RE_Type_Class_Address;
7173 Rewrite (N, New_Occurrence_Of (RTE (Id), Loc));
7176 -----------------------
7177 -- Unbiased_Rounding --
7178 -----------------------
7180 when Attribute_Unbiased_Rounding =>
7182 Eval_Fat.Unbiased_Rounding (P_Root_Type, Expr_Value_R (E1)),
7185 -------------------------
7186 -- Unconstrained_Array --
7187 -------------------------
7189 when Attribute_Unconstrained_Array => Unconstrained_Array : declare
7190 Typ : constant Entity_Id := Underlying_Type (P_Type);
7193 Rewrite (N, New_Occurrence_Of (
7195 Is_Array_Type (P_Type)
7196 and then not Is_Constrained (Typ)), Loc));
7198 -- Analyze and resolve as boolean, note that this attribute is
7199 -- a static attribute in GNAT.
7201 Analyze_And_Resolve (N, Standard_Boolean);
7203 end Unconstrained_Array;
7209 -- Processing is shared with Size
7215 when Attribute_Val => Val :
7217 if Expr_Value (E1) < Expr_Value (Type_Low_Bound (P_Base_Type))
7219 Expr_Value (E1) > Expr_Value (Type_High_Bound (P_Base_Type))
7221 Apply_Compile_Time_Constraint_Error
7222 (N, "Val expression out of range",
7223 CE_Range_Check_Failed,
7224 Warn => not Static);
7230 Fold_Uint (N, Expr_Value (E1), Static);
7238 -- The Value_Size attribute for a type returns the RM size of the
7239 -- type. This an always be folded for scalar types, and can also
7240 -- be folded for non-scalar types if the size is set.
7242 when Attribute_Value_Size => Value_Size : declare
7243 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
7245 if RM_Size (P_TypeA) /= Uint_0 then
7246 Fold_Uint (N, RM_Size (P_TypeA), True);
7254 -- Version can never be static
7256 when Attribute_Version =>
7263 -- Wide_Image is a scalar attribute, but is never static, because it
7264 -- is not a static function (having a non-scalar argument (RM 4.9(22))
7266 when Attribute_Wide_Image =>
7269 ---------------------
7270 -- Wide_Wide_Image --
7271 ---------------------
7273 -- Wide_Wide_Image is a scalar attribute but is never static, because it
7274 -- is not a static function (having a non-scalar argument (RM 4.9(22)).
7276 when Attribute_Wide_Wide_Image =>
7279 ---------------------
7280 -- Wide_Wide_Width --
7281 ---------------------
7283 -- Processing for Wide_Wide_Width is combined with Width
7289 -- Processing for Wide_Width is combined with Width
7295 -- This processing also handles the case of Wide_[Wide_]Width
7297 when Attribute_Width |
7298 Attribute_Wide_Width |
7299 Attribute_Wide_Wide_Width => Width :
7301 if Compile_Time_Known_Bounds (P_Type) then
7303 -- Floating-point types
7305 if Is_Floating_Point_Type (P_Type) then
7307 -- Width is zero for a null range (RM 3.5 (38))
7309 if Expr_Value_R (Type_High_Bound (P_Type)) <
7310 Expr_Value_R (Type_Low_Bound (P_Type))
7312 Fold_Uint (N, Uint_0, True);
7315 -- For floating-point, we have +N.dddE+nnn where length
7316 -- of ddd is determined by type'Digits - 1, but is one
7317 -- if Digits is one (RM 3.5 (33)).
7319 -- nnn is set to 2 for Short_Float and Float (32 bit
7320 -- floats), and 3 for Long_Float and Long_Long_Float.
7321 -- For machines where Long_Long_Float is the IEEE
7322 -- extended precision type, the exponent takes 4 digits.
7326 Int'Max (2, UI_To_Int (Digits_Value (P_Type)));
7329 if Esize (P_Type) <= 32 then
7331 elsif Esize (P_Type) = 64 then
7337 Fold_Uint (N, UI_From_Int (Len), True);
7341 -- Fixed-point types
7343 elsif Is_Fixed_Point_Type (P_Type) then
7345 -- Width is zero for a null range (RM 3.5 (38))
7347 if Expr_Value (Type_High_Bound (P_Type)) <
7348 Expr_Value (Type_Low_Bound (P_Type))
7350 Fold_Uint (N, Uint_0, True);
7352 -- The non-null case depends on the specific real type
7355 -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34))
7358 (N, UI_From_Int (Fore_Value + 1) + Aft_Value (P_Type),
7366 R : constant Entity_Id := Root_Type (P_Type);
7367 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
7368 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
7381 -- Width for types derived from Standard.Character
7382 -- and Standard.Wide_[Wide_]Character.
7384 elsif Is_Standard_Character_Type (P_Type) then
7387 -- Set W larger if needed
7389 for J in UI_To_Int (Lo) .. UI_To_Int (Hi) loop
7391 -- All wide characters look like Hex_hhhhhhhh
7395 -- No need to compute this more than once!
7400 C := Character'Val (J);
7402 -- Test for all cases where Character'Image
7403 -- yields an image that is longer than three
7404 -- characters. First the cases of Reserved_xxx
7405 -- names (length = 12).
7408 when Reserved_128 | Reserved_129 |
7409 Reserved_132 | Reserved_153
7412 when BS | HT | LF | VT | FF | CR |
7413 SO | SI | EM | FS | GS | RS |
7414 US | RI | MW | ST | PM
7417 when NUL | SOH | STX | ETX | EOT |
7418 ENQ | ACK | BEL | DLE | DC1 |
7419 DC2 | DC3 | DC4 | NAK | SYN |
7420 ETB | CAN | SUB | ESC | DEL |
7421 BPH | NBH | NEL | SSA | ESA |
7422 HTS | HTJ | VTS | PLD | PLU |
7423 SS2 | SS3 | DCS | PU1 | PU2 |
7424 STS | CCH | SPA | EPA | SOS |
7425 SCI | CSI | OSC | APC
7428 when Space .. Tilde |
7429 No_Break_Space .. LC_Y_Diaeresis
7431 -- Special case of soft hyphen in Ada 2005
7433 if C = Character'Val (16#AD#)
7434 and then Ada_Version >= Ada_2005
7442 W := Int'Max (W, Wt);
7446 -- Width for types derived from Standard.Boolean
7448 elsif R = Standard_Boolean then
7455 -- Width for integer types
7457 elsif Is_Integer_Type (P_Type) then
7458 T := UI_Max (abs Lo, abs Hi);
7466 -- Only remaining possibility is user declared enum type
7469 pragma Assert (Is_Enumeration_Type (P_Type));
7472 L := First_Literal (P_Type);
7474 while Present (L) loop
7476 -- Only pay attention to in range characters
7478 if Lo <= Enumeration_Pos (L)
7479 and then Enumeration_Pos (L) <= Hi
7481 -- For Width case, use decoded name
7483 if Id = Attribute_Width then
7484 Get_Decoded_Name_String (Chars (L));
7485 Wt := Nat (Name_Len);
7487 -- For Wide_[Wide_]Width, use encoded name, and
7488 -- then adjust for the encoding.
7491 Get_Name_String (Chars (L));
7493 -- Character literals are always of length 3
7495 if Name_Buffer (1) = 'Q' then
7498 -- Otherwise loop to adjust for upper/wide chars
7501 Wt := Nat (Name_Len);
7503 for J in 1 .. Name_Len loop
7504 if Name_Buffer (J) = 'U' then
7506 elsif Name_Buffer (J) = 'W' then
7513 W := Int'Max (W, Wt);
7520 Fold_Uint (N, UI_From_Int (W), True);
7526 -- The following attributes denote functions that cannot be folded
7528 when Attribute_From_Any |
7530 Attribute_TypeCode =>
7533 -- The following attributes can never be folded, and furthermore we
7534 -- should not even have entered the case statement for any of these.
7535 -- Note that in some cases, the values have already been folded as
7536 -- a result of the processing in Analyze_Attribute.
7538 when Attribute_Abort_Signal |
7541 Attribute_Address_Size |
7542 Attribute_Asm_Input |
7543 Attribute_Asm_Output |
7545 Attribute_Bit_Order |
7546 Attribute_Bit_Position |
7547 Attribute_Callable |
7550 Attribute_Code_Address |
7551 Attribute_Compiler_Version |
7553 Attribute_Default_Bit_Order |
7554 Attribute_Elaborated |
7555 Attribute_Elab_Body |
7556 Attribute_Elab_Spec |
7558 Attribute_External_Tag |
7559 Attribute_Fast_Math |
7560 Attribute_First_Bit |
7562 Attribute_Last_Bit |
7563 Attribute_Maximum_Alignment |
7566 Attribute_Partition_ID |
7567 Attribute_Pool_Address |
7568 Attribute_Position |
7569 Attribute_Priority |
7572 Attribute_Storage_Pool |
7573 Attribute_Storage_Size |
7574 Attribute_Storage_Unit |
7575 Attribute_Stub_Type |
7577 Attribute_Target_Name |
7578 Attribute_Terminated |
7579 Attribute_To_Address |
7580 Attribute_Type_Key |
7581 Attribute_UET_Address |
7582 Attribute_Unchecked_Access |
7583 Attribute_Universal_Literal_String |
7584 Attribute_Unrestricted_Access |
7587 Attribute_Wchar_T_Size |
7588 Attribute_Wide_Value |
7589 Attribute_Wide_Wide_Value |
7590 Attribute_Word_Size |
7593 raise Program_Error;
7596 -- At the end of the case, one more check. If we did a static evaluation
7597 -- so that the result is now a literal, then set Is_Static_Expression
7598 -- in the constant only if the prefix type is a static subtype. For
7599 -- non-static subtypes, the folding is still OK, but not static.
7601 -- An exception is the GNAT attribute Constrained_Array which is
7602 -- defined to be a static attribute in all cases.
7604 if Nkind_In (N, N_Integer_Literal,
7606 N_Character_Literal,
7608 or else (Is_Entity_Name (N)
7609 and then Ekind (Entity (N)) = E_Enumeration_Literal)
7611 Set_Is_Static_Expression (N, Static);
7613 -- If this is still an attribute reference, then it has not been folded
7614 -- and that means that its expressions are in a non-static context.
7616 elsif Nkind (N) = N_Attribute_Reference then
7619 -- Note: the else case not covered here are odd cases where the
7620 -- processing has transformed the attribute into something other
7621 -- than a constant. Nothing more to do in such cases.
7628 ------------------------------
7629 -- Is_Anonymous_Tagged_Base --
7630 ------------------------------
7632 function Is_Anonymous_Tagged_Base
7639 Anon = Current_Scope
7640 and then Is_Itype (Anon)
7641 and then Associated_Node_For_Itype (Anon) = Parent (Typ);
7642 end Is_Anonymous_Tagged_Base;
7644 --------------------------------
7645 -- Name_Implies_Lvalue_Prefix --
7646 --------------------------------
7648 function Name_Implies_Lvalue_Prefix (Nam : Name_Id) return Boolean is
7649 pragma Assert (Is_Attribute_Name (Nam));
7651 return Attribute_Name_Implies_Lvalue_Prefix (Get_Attribute_Id (Nam));
7652 end Name_Implies_Lvalue_Prefix;
7654 -----------------------
7655 -- Resolve_Attribute --
7656 -----------------------
7658 procedure Resolve_Attribute (N : Node_Id; Typ : Entity_Id) is
7659 Loc : constant Source_Ptr := Sloc (N);
7660 P : constant Node_Id := Prefix (N);
7661 Aname : constant Name_Id := Attribute_Name (N);
7662 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
7663 Btyp : constant Entity_Id := Base_Type (Typ);
7664 Des_Btyp : Entity_Id;
7665 Index : Interp_Index;
7667 Nom_Subt : Entity_Id;
7669 procedure Accessibility_Message;
7670 -- Error, or warning within an instance, if the static accessibility
7671 -- rules of 3.10.2 are violated.
7673 ---------------------------
7674 -- Accessibility_Message --
7675 ---------------------------
7677 procedure Accessibility_Message is
7678 Indic : Node_Id := Parent (Parent (N));
7681 -- In an instance, this is a runtime check, but one we
7682 -- know will fail, so generate an appropriate warning.
7684 if In_Instance_Body then
7685 Error_Msg_F ("?non-local pointer cannot point to local object", P);
7687 ("\?Program_Error will be raised at run time", P);
7689 Make_Raise_Program_Error (Loc,
7690 Reason => PE_Accessibility_Check_Failed));
7695 Error_Msg_F ("non-local pointer cannot point to local object", P);
7697 -- Check for case where we have a missing access definition
7699 if Is_Record_Type (Current_Scope)
7701 Nkind_In (Parent (N), N_Discriminant_Association,
7702 N_Index_Or_Discriminant_Constraint)
7704 Indic := Parent (Parent (N));
7705 while Present (Indic)
7706 and then Nkind (Indic) /= N_Subtype_Indication
7708 Indic := Parent (Indic);
7711 if Present (Indic) then
7713 ("\use an access definition for" &
7714 " the access discriminant of&",
7715 N, Entity (Subtype_Mark (Indic)));
7719 end Accessibility_Message;
7721 -- Start of processing for Resolve_Attribute
7724 -- If error during analysis, no point in continuing, except for array
7725 -- types, where we get better recovery by using unconstrained indexes
7726 -- than nothing at all (see Check_Array_Type).
7729 and then Attr_Id /= Attribute_First
7730 and then Attr_Id /= Attribute_Last
7731 and then Attr_Id /= Attribute_Length
7732 and then Attr_Id /= Attribute_Range
7737 -- If attribute was universal type, reset to actual type
7739 if Etype (N) = Universal_Integer
7740 or else Etype (N) = Universal_Real
7745 -- Remaining processing depends on attribute
7753 -- For access attributes, if the prefix denotes an entity, it is
7754 -- interpreted as a name, never as a call. It may be overloaded,
7755 -- in which case resolution uses the profile of the context type.
7756 -- Otherwise prefix must be resolved.
7758 when Attribute_Access
7759 | Attribute_Unchecked_Access
7760 | Attribute_Unrestricted_Access =>
7764 if Is_Variable (P) then
7765 Note_Possible_Modification (P, Sure => False);
7768 -- The following comes from a query by Adam Beneschan, concerning
7769 -- improper use of universal_access in equality tests involving
7770 -- anonymous access types. Another good reason for 'Ref, but
7771 -- for now disable the test, which breaks several filed tests.
7773 if Ekind (Typ) = E_Anonymous_Access_Type
7774 and then Nkind_In (Parent (N), N_Op_Eq, N_Op_Ne)
7777 Error_Msg_N ("need unique type to resolve 'Access", N);
7778 Error_Msg_N ("\qualify attribute with some access type", N);
7781 if Is_Entity_Name (P) then
7782 if Is_Overloaded (P) then
7783 Get_First_Interp (P, Index, It);
7784 while Present (It.Nam) loop
7785 if Type_Conformant (Designated_Type (Typ), It.Nam) then
7786 Set_Entity (P, It.Nam);
7788 -- The prefix is definitely NOT overloaded anymore at
7789 -- this point, so we reset the Is_Overloaded flag to
7790 -- avoid any confusion when reanalyzing the node.
7792 Set_Is_Overloaded (P, False);
7793 Set_Is_Overloaded (N, False);
7794 Generate_Reference (Entity (P), P);
7798 Get_Next_Interp (Index, It);
7801 -- If Prefix is a subprogram name, it is frozen by this
7804 -- If it is a type, there is nothing to resolve.
7805 -- If it is an object, complete its resolution.
7807 elsif Is_Overloadable (Entity (P)) then
7809 -- Avoid insertion of freeze actions in spec expression mode
7811 if not In_Spec_Expression then
7812 Freeze_Before (N, Entity (P));
7815 elsif Is_Type (Entity (P)) then
7821 Error_Msg_Name_1 := Aname;
7823 if not Is_Entity_Name (P) then
7826 elsif Is_Overloadable (Entity (P))
7827 and then Is_Abstract_Subprogram (Entity (P))
7829 Error_Msg_F ("prefix of % attribute cannot be abstract", P);
7830 Set_Etype (N, Any_Type);
7832 elsif Convention (Entity (P)) = Convention_Intrinsic then
7833 if Ekind (Entity (P)) = E_Enumeration_Literal then
7835 ("prefix of % attribute cannot be enumeration literal",
7839 ("prefix of % attribute cannot be intrinsic", P);
7842 Set_Etype (N, Any_Type);
7845 -- Assignments, return statements, components of aggregates,
7846 -- generic instantiations will require convention checks if
7847 -- the type is an access to subprogram. Given that there will
7848 -- also be accessibility checks on those, this is where the
7849 -- checks can eventually be centralized ???
7851 if Ekind_In (Btyp, E_Access_Subprogram_Type,
7852 E_Anonymous_Access_Subprogram_Type,
7853 E_Access_Protected_Subprogram_Type,
7854 E_Anonymous_Access_Protected_Subprogram_Type)
7856 -- Deal with convention mismatch
7858 if Convention (Designated_Type (Btyp)) /=
7859 Convention (Entity (P))
7862 ("subprogram & has wrong convention", P, Entity (P));
7864 ("\does not match convention of access type &",
7867 if not Has_Convention_Pragma (Btyp) then
7869 ("\probable missing pragma Convention for &",
7874 Check_Subtype_Conformant
7875 (New_Id => Entity (P),
7876 Old_Id => Designated_Type (Btyp),
7880 if Attr_Id = Attribute_Unchecked_Access then
7881 Error_Msg_Name_1 := Aname;
7883 ("attribute% cannot be applied to a subprogram", P);
7885 elsif Aname = Name_Unrestricted_Access then
7886 null; -- Nothing to check
7888 -- Check the static accessibility rule of 3.10.2(32).
7889 -- This rule also applies within the private part of an
7890 -- instantiation. This rule does not apply to anonymous
7891 -- access-to-subprogram types in access parameters.
7893 elsif Attr_Id = Attribute_Access
7894 and then not In_Instance_Body
7896 (Ekind (Btyp) = E_Access_Subprogram_Type
7897 or else Is_Local_Anonymous_Access (Btyp))
7899 and then Subprogram_Access_Level (Entity (P)) >
7900 Type_Access_Level (Btyp)
7903 ("subprogram must not be deeper than access type", P);
7905 -- Check the restriction of 3.10.2(32) that disallows the
7906 -- access attribute within a generic body when the ultimate
7907 -- ancestor of the type of the attribute is declared outside
7908 -- of the generic unit and the subprogram is declared within
7909 -- that generic unit. This includes any such attribute that
7910 -- occurs within the body of a generic unit that is a child
7911 -- of the generic unit where the subprogram is declared.
7913 -- The rule also prohibits applying the attribute when the
7914 -- access type is a generic formal access type (since the
7915 -- level of the actual type is not known). This restriction
7916 -- does not apply when the attribute type is an anonymous
7917 -- access-to-subprogram type. Note that this check was
7918 -- revised by AI-229, because the originally Ada 95 rule
7919 -- was too lax. The original rule only applied when the
7920 -- subprogram was declared within the body of the generic,
7921 -- which allowed the possibility of dangling references).
7922 -- The rule was also too strict in some case, in that it
7923 -- didn't permit the access to be declared in the generic
7924 -- spec, whereas the revised rule does (as long as it's not
7927 -- There are a couple of subtleties of the test for applying
7928 -- the check that are worth noting. First, we only apply it
7929 -- when the levels of the subprogram and access type are the
7930 -- same (the case where the subprogram is statically deeper
7931 -- was applied above, and the case where the type is deeper
7932 -- is always safe). Second, we want the check to apply
7933 -- within nested generic bodies and generic child unit
7934 -- bodies, but not to apply to an attribute that appears in
7935 -- the generic unit's specification. This is done by testing
7936 -- that the attribute's innermost enclosing generic body is
7937 -- not the same as the innermost generic body enclosing the
7938 -- generic unit where the subprogram is declared (we don't
7939 -- want the check to apply when the access attribute is in
7940 -- the spec and there's some other generic body enclosing
7941 -- generic). Finally, there's no point applying the check
7942 -- when within an instance, because any violations will have
7943 -- been caught by the compilation of the generic unit.
7945 -- Note that we relax this check in CodePeer mode for
7946 -- compatibility with legacy code, since CodePeer is an
7947 -- Ada source code analyzer, not a strict compiler.
7948 -- ??? Note that a better approach would be to have a
7949 -- separate switch to relax this rule, and enable this
7950 -- switch in CodePeer mode.
7952 elsif Attr_Id = Attribute_Access
7953 and then not CodePeer_Mode
7954 and then not In_Instance
7955 and then Present (Enclosing_Generic_Unit (Entity (P)))
7956 and then Present (Enclosing_Generic_Body (N))
7957 and then Enclosing_Generic_Body (N) /=
7958 Enclosing_Generic_Body
7959 (Enclosing_Generic_Unit (Entity (P)))
7960 and then Subprogram_Access_Level (Entity (P)) =
7961 Type_Access_Level (Btyp)
7962 and then Ekind (Btyp) /=
7963 E_Anonymous_Access_Subprogram_Type
7964 and then Ekind (Btyp) /=
7965 E_Anonymous_Access_Protected_Subprogram_Type
7967 -- The attribute type's ultimate ancestor must be
7968 -- declared within the same generic unit as the
7969 -- subprogram is declared. The error message is
7970 -- specialized to say "ancestor" for the case where the
7971 -- access type is not its own ancestor, since saying
7972 -- simply "access type" would be very confusing.
7974 if Enclosing_Generic_Unit (Entity (P)) /=
7975 Enclosing_Generic_Unit (Root_Type (Btyp))
7978 ("''Access attribute not allowed in generic body",
7981 if Root_Type (Btyp) = Btyp then
7984 "access type & is declared outside " &
7985 "generic unit (RM 3.10.2(32))", N, Btyp);
7988 ("\because ancestor of " &
7989 "access type & is declared outside " &
7990 "generic unit (RM 3.10.2(32))", N, Btyp);
7994 ("\move ''Access to private part, or " &
7995 "(Ada 2005) use anonymous access type instead of &",
7998 -- If the ultimate ancestor of the attribute's type is
7999 -- a formal type, then the attribute is illegal because
8000 -- the actual type might be declared at a higher level.
8001 -- The error message is specialized to say "ancestor"
8002 -- for the case where the access type is not its own
8003 -- ancestor, since saying simply "access type" would be
8006 elsif Is_Generic_Type (Root_Type (Btyp)) then
8007 if Root_Type (Btyp) = Btyp then
8009 ("access type must not be a generic formal type",
8013 ("ancestor access type must not be a generic " &
8020 -- If this is a renaming, an inherited operation, or a
8021 -- subprogram instance, use the original entity. This may make
8022 -- the node type-inconsistent, so this transformation can only
8023 -- be done if the node will not be reanalyzed. In particular,
8024 -- if it is within a default expression, the transformation
8025 -- must be delayed until the default subprogram is created for
8026 -- it, when the enclosing subprogram is frozen.
8028 if Is_Entity_Name (P)
8029 and then Is_Overloadable (Entity (P))
8030 and then Present (Alias (Entity (P)))
8031 and then Expander_Active
8034 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
8037 elsif Nkind (P) = N_Selected_Component
8038 and then Is_Overloadable (Entity (Selector_Name (P)))
8040 -- Protected operation. If operation is overloaded, must
8041 -- disambiguate. Prefix that denotes protected object itself
8042 -- is resolved with its own type.
8044 if Attr_Id = Attribute_Unchecked_Access then
8045 Error_Msg_Name_1 := Aname;
8047 ("attribute% cannot be applied to protected operation", P);
8050 Resolve (Prefix (P));
8051 Generate_Reference (Entity (Selector_Name (P)), P);
8053 elsif Is_Overloaded (P) then
8055 -- Use the designated type of the context to disambiguate
8056 -- Note that this was not strictly conformant to Ada 95,
8057 -- but was the implementation adopted by most Ada 95 compilers.
8058 -- The use of the context type to resolve an Access attribute
8059 -- reference is now mandated in AI-235 for Ada 2005.
8062 Index : Interp_Index;
8066 Get_First_Interp (P, Index, It);
8067 while Present (It.Typ) loop
8068 if Covers (Designated_Type (Typ), It.Typ) then
8069 Resolve (P, It.Typ);
8073 Get_Next_Interp (Index, It);
8080 -- X'Access is illegal if X denotes a constant and the access type
8081 -- is access-to-variable. Same for 'Unchecked_Access. The rule
8082 -- does not apply to 'Unrestricted_Access. If the reference is a
8083 -- default-initialized aggregate component for a self-referential
8084 -- type the reference is legal.
8086 if not (Ekind (Btyp) = E_Access_Subprogram_Type
8087 or else Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type
8088 or else (Is_Record_Type (Btyp)
8090 Present (Corresponding_Remote_Type (Btyp)))
8091 or else Ekind (Btyp) = E_Access_Protected_Subprogram_Type
8092 or else Ekind (Btyp)
8093 = E_Anonymous_Access_Protected_Subprogram_Type
8094 or else Is_Access_Constant (Btyp)
8095 or else Is_Variable (P)
8096 or else Attr_Id = Attribute_Unrestricted_Access)
8098 if Is_Entity_Name (P)
8099 and then Is_Type (Entity (P))
8101 -- Legality of a self-reference through an access
8102 -- attribute has been verified in Analyze_Access_Attribute.
8106 elsif Comes_From_Source (N) then
8107 Error_Msg_F ("access-to-variable designates constant", P);
8111 Des_Btyp := Designated_Type (Btyp);
8113 if Ada_Version >= Ada_2005
8114 and then Is_Incomplete_Type (Des_Btyp)
8116 -- Ada 2005 (AI-412): If the (sub)type is a limited view of an
8117 -- imported entity, and the non-limited view is visible, make
8118 -- use of it. If it is an incomplete subtype, use the base type
8121 if From_With_Type (Des_Btyp)
8122 and then Present (Non_Limited_View (Des_Btyp))
8124 Des_Btyp := Non_Limited_View (Des_Btyp);
8126 elsif Ekind (Des_Btyp) = E_Incomplete_Subtype then
8127 Des_Btyp := Etype (Des_Btyp);
8131 if (Attr_Id = Attribute_Access
8133 Attr_Id = Attribute_Unchecked_Access)
8134 and then (Ekind (Btyp) = E_General_Access_Type
8135 or else Ekind (Btyp) = E_Anonymous_Access_Type)
8137 -- Ada 2005 (AI-230): Check the accessibility of anonymous
8138 -- access types for stand-alone objects, record and array
8139 -- components, and return objects. For a component definition
8140 -- the level is the same of the enclosing composite type.
8142 if Ada_Version >= Ada_2005
8143 and then Is_Local_Anonymous_Access (Btyp)
8144 and then Object_Access_Level (P) > Type_Access_Level (Btyp)
8145 and then Attr_Id = Attribute_Access
8147 -- In an instance, this is a runtime check, but one we
8148 -- know will fail, so generate an appropriate warning.
8150 if In_Instance_Body then
8152 ("?non-local pointer cannot point to local object", P);
8154 ("\?Program_Error will be raised at run time", P);
8156 Make_Raise_Program_Error (Loc,
8157 Reason => PE_Accessibility_Check_Failed));
8162 ("non-local pointer cannot point to local object", P);
8166 if Is_Dependent_Component_Of_Mutable_Object (P) then
8168 ("illegal attribute for discriminant-dependent component",
8172 -- Check static matching rule of 3.10.2(27). Nominal subtype
8173 -- of the prefix must statically match the designated type.
8175 Nom_Subt := Etype (P);
8177 if Is_Constr_Subt_For_U_Nominal (Nom_Subt) then
8178 Nom_Subt := Base_Type (Nom_Subt);
8181 if Is_Tagged_Type (Designated_Type (Typ)) then
8183 -- If the attribute is in the context of an access
8184 -- parameter, then the prefix is allowed to be of the
8185 -- class-wide type (by AI-127).
8187 if Ekind (Typ) = E_Anonymous_Access_Type then
8188 if not Covers (Designated_Type (Typ), Nom_Subt)
8189 and then not Covers (Nom_Subt, Designated_Type (Typ))
8195 Desig := Designated_Type (Typ);
8197 if Is_Class_Wide_Type (Desig) then
8198 Desig := Etype (Desig);
8201 if Is_Anonymous_Tagged_Base (Nom_Subt, Desig) then
8206 ("type of prefix: & not compatible",
8209 ("\with &, the expected designated type",
8210 P, Designated_Type (Typ));
8215 elsif not Covers (Designated_Type (Typ), Nom_Subt)
8217 (not Is_Class_Wide_Type (Designated_Type (Typ))
8218 and then Is_Class_Wide_Type (Nom_Subt))
8221 ("type of prefix: & is not covered", P, Nom_Subt);
8223 ("\by &, the expected designated type" &
8224 " (RM 3.10.2 (27))", P, Designated_Type (Typ));
8227 if Is_Class_Wide_Type (Designated_Type (Typ))
8228 and then Has_Discriminants (Etype (Designated_Type (Typ)))
8229 and then Is_Constrained (Etype (Designated_Type (Typ)))
8230 and then Designated_Type (Typ) /= Nom_Subt
8232 Apply_Discriminant_Check
8233 (N, Etype (Designated_Type (Typ)));
8236 -- Ada 2005 (AI-363): Require static matching when designated
8237 -- type has discriminants and a constrained partial view, since
8238 -- in general objects of such types are mutable, so we can't
8239 -- allow the access value to designate a constrained object
8240 -- (because access values must be assumed to designate mutable
8241 -- objects when designated type does not impose a constraint).
8243 elsif Subtypes_Statically_Match (Des_Btyp, Nom_Subt) then
8246 elsif Has_Discriminants (Designated_Type (Typ))
8247 and then not Is_Constrained (Des_Btyp)
8249 (Ada_Version < Ada_2005
8251 not Has_Constrained_Partial_View
8252 (Designated_Type (Base_Type (Typ))))
8258 ("object subtype must statically match "
8259 & "designated subtype", P);
8261 if Is_Entity_Name (P)
8262 and then Is_Array_Type (Designated_Type (Typ))
8265 D : constant Node_Id := Declaration_Node (Entity (P));
8268 Error_Msg_N ("aliased object has explicit bounds?",
8270 Error_Msg_N ("\declare without bounds"
8271 & " (and with explicit initialization)?", D);
8272 Error_Msg_N ("\for use with unconstrained access?", D);
8277 -- Check the static accessibility rule of 3.10.2(28).
8278 -- Note that this check is not performed for the
8279 -- case of an anonymous access type, since the access
8280 -- attribute is always legal in such a context.
8282 if Attr_Id /= Attribute_Unchecked_Access
8283 and then Object_Access_Level (P) > Type_Access_Level (Btyp)
8284 and then Ekind (Btyp) = E_General_Access_Type
8286 Accessibility_Message;
8291 if Ekind_In (Btyp, E_Access_Protected_Subprogram_Type,
8292 E_Anonymous_Access_Protected_Subprogram_Type)
8294 if Is_Entity_Name (P)
8295 and then not Is_Protected_Type (Scope (Entity (P)))
8297 Error_Msg_F ("context requires a protected subprogram", P);
8299 -- Check accessibility of protected object against that of the
8300 -- access type, but only on user code, because the expander
8301 -- creates access references for handlers. If the context is an
8302 -- anonymous_access_to_protected, there are no accessibility
8303 -- checks either. Omit check entirely for Unrestricted_Access.
8305 elsif Object_Access_Level (P) > Type_Access_Level (Btyp)
8306 and then Comes_From_Source (N)
8307 and then Ekind (Btyp) = E_Access_Protected_Subprogram_Type
8308 and then Attr_Id /= Attribute_Unrestricted_Access
8310 Accessibility_Message;
8314 elsif Ekind_In (Btyp, E_Access_Subprogram_Type,
8315 E_Anonymous_Access_Subprogram_Type)
8316 and then Ekind (Etype (N)) = E_Access_Protected_Subprogram_Type
8318 Error_Msg_F ("context requires a non-protected subprogram", P);
8321 -- The context cannot be a pool-specific type, but this is a
8322 -- legality rule, not a resolution rule, so it must be checked
8323 -- separately, after possibly disambiguation (see AI-245).
8325 if Ekind (Btyp) = E_Access_Type
8326 and then Attr_Id /= Attribute_Unrestricted_Access
8328 Wrong_Type (N, Typ);
8331 -- The context may be a constrained access type (however ill-
8332 -- advised such subtypes might be) so in order to generate a
8333 -- constraint check when needed set the type of the attribute
8334 -- reference to the base type of the context.
8336 Set_Etype (N, Btyp);
8338 -- Check for incorrect atomic/volatile reference (RM C.6(12))
8340 if Attr_Id /= Attribute_Unrestricted_Access then
8341 if Is_Atomic_Object (P)
8342 and then not Is_Atomic (Designated_Type (Typ))
8345 ("access to atomic object cannot yield access-to-" &
8346 "non-atomic type", P);
8348 elsif Is_Volatile_Object (P)
8349 and then not Is_Volatile (Designated_Type (Typ))
8352 ("access to volatile object cannot yield access-to-" &
8353 "non-volatile type", P);
8357 if Is_Entity_Name (P) then
8358 Set_Address_Taken (Entity (P));
8360 end Access_Attribute;
8366 -- Deal with resolving the type for Address attribute, overloading
8367 -- is not permitted here, since there is no context to resolve it.
8369 when Attribute_Address | Attribute_Code_Address =>
8370 Address_Attribute : begin
8372 -- To be safe, assume that if the address of a variable is taken,
8373 -- it may be modified via this address, so note modification.
8375 if Is_Variable (P) then
8376 Note_Possible_Modification (P, Sure => False);
8379 if Nkind (P) in N_Subexpr
8380 and then Is_Overloaded (P)
8382 Get_First_Interp (P, Index, It);
8383 Get_Next_Interp (Index, It);
8385 if Present (It.Nam) then
8386 Error_Msg_Name_1 := Aname;
8388 ("prefix of % attribute cannot be overloaded", P);
8392 if not Is_Entity_Name (P)
8393 or else not Is_Overloadable (Entity (P))
8395 if not Is_Task_Type (Etype (P))
8396 or else Nkind (P) = N_Explicit_Dereference
8402 -- If this is the name of a derived subprogram, or that of a
8403 -- generic actual, the address is that of the original entity.
8405 if Is_Entity_Name (P)
8406 and then Is_Overloadable (Entity (P))
8407 and then Present (Alias (Entity (P)))
8410 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
8413 if Is_Entity_Name (P) then
8414 Set_Address_Taken (Entity (P));
8417 if Nkind (P) = N_Slice then
8419 -- Arr (X .. Y)'address is identical to Arr (X)'address,
8420 -- even if the array is packed and the slice itself is not
8421 -- addressable. Transform the prefix into an indexed component.
8423 -- Note that the transformation is safe only if we know that
8424 -- the slice is non-null. That is because a null slice can have
8425 -- an out of bounds index value.
8427 -- Right now, gigi blows up if given 'Address on a slice as a
8428 -- result of some incorrect freeze nodes generated by the front
8429 -- end, and this covers up that bug in one case, but the bug is
8430 -- likely still there in the cases not handled by this code ???
8432 -- It's not clear what 'Address *should* return for a null
8433 -- slice with out of bounds indexes, this might be worth an ARG
8436 -- One approach would be to do a length check unconditionally,
8437 -- and then do the transformation below unconditionally, but
8438 -- analyze with checks off, avoiding the problem of the out of
8439 -- bounds index. This approach would interpret the address of
8440 -- an out of bounds null slice as being the address where the
8441 -- array element would be if there was one, which is probably
8442 -- as reasonable an interpretation as any ???
8445 Loc : constant Source_Ptr := Sloc (P);
8446 D : constant Node_Id := Discrete_Range (P);
8450 if Is_Entity_Name (D)
8453 (Type_Low_Bound (Entity (D)),
8454 Type_High_Bound (Entity (D)))
8457 Make_Attribute_Reference (Loc,
8458 Prefix => (New_Occurrence_Of (Entity (D), Loc)),
8459 Attribute_Name => Name_First);
8461 elsif Nkind (D) = N_Range
8462 and then Not_Null_Range (Low_Bound (D), High_Bound (D))
8464 Lo := Low_Bound (D);
8470 if Present (Lo) then
8472 Make_Indexed_Component (Loc,
8473 Prefix => Relocate_Node (Prefix (P)),
8474 Expressions => New_List (Lo)));
8476 Analyze_And_Resolve (P);
8480 end Address_Attribute;
8486 -- Prefix of the AST_Entry attribute is an entry name which must
8487 -- not be resolved, since this is definitely not an entry call.
8489 when Attribute_AST_Entry =>
8496 -- Prefix of Body_Version attribute can be a subprogram name which
8497 -- must not be resolved, since this is not a call.
8499 when Attribute_Body_Version =>
8506 -- Prefix of Caller attribute is an entry name which must not
8507 -- be resolved, since this is definitely not an entry call.
8509 when Attribute_Caller =>
8516 -- Shares processing with Address attribute
8522 -- If the prefix of the Count attribute is an entry name it must not
8523 -- be resolved, since this is definitely not an entry call. However,
8524 -- if it is an element of an entry family, the index itself may
8525 -- have to be resolved because it can be a general expression.
8527 when Attribute_Count =>
8528 if Nkind (P) = N_Indexed_Component
8529 and then Is_Entity_Name (Prefix (P))
8532 Indx : constant Node_Id := First (Expressions (P));
8533 Fam : constant Entity_Id := Entity (Prefix (P));
8535 Resolve (Indx, Entry_Index_Type (Fam));
8536 Apply_Range_Check (Indx, Entry_Index_Type (Fam));
8544 -- Prefix of the Elaborated attribute is a subprogram name which
8545 -- must not be resolved, since this is definitely not a call. Note
8546 -- that it is a library unit, so it cannot be overloaded here.
8548 when Attribute_Elaborated =>
8555 -- Prefix of Enabled attribute is a check name, which must be treated
8556 -- specially and not touched by Resolve.
8558 when Attribute_Enabled =>
8561 --------------------
8562 -- Mechanism_Code --
8563 --------------------
8565 -- Prefix of the Mechanism_Code attribute is a function name
8566 -- which must not be resolved. Should we check for overloaded ???
8568 when Attribute_Mechanism_Code =>
8575 -- Most processing is done in sem_dist, after determining the
8576 -- context type. Node is rewritten as a conversion to a runtime call.
8578 when Attribute_Partition_ID =>
8579 Process_Partition_Id (N);
8586 when Attribute_Pool_Address =>
8593 -- We replace the Range attribute node with a range expression whose
8594 -- bounds are the 'First and 'Last attributes applied to the same
8595 -- prefix. The reason that we do this transformation here instead of
8596 -- in the expander is that it simplifies other parts of the semantic
8597 -- analysis which assume that the Range has been replaced; thus it
8598 -- must be done even when in semantic-only mode (note that the RM
8599 -- specifically mentions this equivalence, we take care that the
8600 -- prefix is only evaluated once).
8602 when Attribute_Range => Range_Attribute :
8608 if not Is_Entity_Name (P)
8609 or else not Is_Type (Entity (P))
8615 Make_Attribute_Reference (Loc,
8617 Duplicate_Subexpr (P, Name_Req => True),
8618 Attribute_Name => Name_Last,
8619 Expressions => Expressions (N));
8622 Make_Attribute_Reference (Loc,
8624 Attribute_Name => Name_First,
8625 Expressions => Expressions (N));
8627 -- If the original was marked as Must_Not_Freeze (see code
8628 -- in Sem_Ch3.Make_Index), then make sure the rewriting
8629 -- does not freeze either.
8631 if Must_Not_Freeze (N) then
8632 Set_Must_Not_Freeze (HB);
8633 Set_Must_Not_Freeze (LB);
8634 Set_Must_Not_Freeze (Prefix (HB));
8635 Set_Must_Not_Freeze (Prefix (LB));
8638 if Raises_Constraint_Error (Prefix (N)) then
8640 -- Preserve Sloc of prefix in the new bounds, so that
8641 -- the posted warning can be removed if we are within
8642 -- unreachable code.
8644 Set_Sloc (LB, Sloc (Prefix (N)));
8645 Set_Sloc (HB, Sloc (Prefix (N)));
8648 Rewrite (N, Make_Range (Loc, LB, HB));
8649 Analyze_And_Resolve (N, Typ);
8651 -- Ensure that the expanded range does not have side effects
8653 Force_Evaluation (LB);
8654 Force_Evaluation (HB);
8656 -- Normally after resolving attribute nodes, Eval_Attribute
8657 -- is called to do any possible static evaluation of the node.
8658 -- However, here since the Range attribute has just been
8659 -- transformed into a range expression it is no longer an
8660 -- attribute node and therefore the call needs to be avoided
8661 -- and is accomplished by simply returning from the procedure.
8664 end Range_Attribute;
8670 -- We will only come here during the prescan of a spec expression
8671 -- containing a Result attribute. In that case the proper Etype has
8672 -- already been set, and nothing more needs to be done here.
8674 when Attribute_Result =>
8681 -- Prefix must not be resolved in this case, since it is not a
8682 -- real entity reference. No action of any kind is require!
8684 when Attribute_UET_Address =>
8687 ----------------------
8688 -- Unchecked_Access --
8689 ----------------------
8691 -- Processing is shared with Access
8693 -------------------------
8694 -- Unrestricted_Access --
8695 -------------------------
8697 -- Processing is shared with Access
8703 -- Apply range check. Note that we did not do this during the
8704 -- analysis phase, since we wanted Eval_Attribute to have a
8705 -- chance at finding an illegal out of range value.
8707 when Attribute_Val =>
8709 -- Note that we do our own Eval_Attribute call here rather than
8710 -- use the common one, because we need to do processing after
8711 -- the call, as per above comment.
8715 -- Eval_Attribute may replace the node with a raise CE, or
8716 -- fold it to a constant. Obviously we only apply a scalar
8717 -- range check if this did not happen!
8719 if Nkind (N) = N_Attribute_Reference
8720 and then Attribute_Name (N) = Name_Val
8722 Apply_Scalar_Range_Check (First (Expressions (N)), Btyp);
8731 -- Prefix of Version attribute can be a subprogram name which
8732 -- must not be resolved, since this is not a call.
8734 when Attribute_Version =>
8737 ----------------------
8738 -- Other Attributes --
8739 ----------------------
8741 -- For other attributes, resolve prefix unless it is a type. If
8742 -- the attribute reference itself is a type name ('Base and 'Class)
8743 -- then this is only legal within a task or protected record.
8746 if not Is_Entity_Name (P)
8747 or else not Is_Type (Entity (P))
8752 -- If the attribute reference itself is a type name ('Base,
8753 -- 'Class) then this is only legal within a task or protected
8754 -- record. What is this all about ???
8756 if Is_Entity_Name (N)
8757 and then Is_Type (Entity (N))
8759 if Is_Concurrent_Type (Entity (N))
8760 and then In_Open_Scopes (Entity (P))
8765 ("invalid use of subtype name in expression or call", N);
8769 -- For attributes whose argument may be a string, complete
8770 -- resolution of argument now. This avoids premature expansion
8771 -- (and the creation of transient scopes) before the attribute
8772 -- reference is resolved.
8775 when Attribute_Value =>
8776 Resolve (First (Expressions (N)), Standard_String);
8778 when Attribute_Wide_Value =>
8779 Resolve (First (Expressions (N)), Standard_Wide_String);
8781 when Attribute_Wide_Wide_Value =>
8782 Resolve (First (Expressions (N)), Standard_Wide_Wide_String);
8784 when others => null;
8787 -- If the prefix of the attribute is a class-wide type then it
8788 -- will be expanded into a dispatching call to a predefined
8789 -- primitive. Therefore we must check for potential violation
8790 -- of such restriction.
8792 if Is_Class_Wide_Type (Etype (P)) then
8793 Check_Restriction (No_Dispatching_Calls, N);
8797 -- Normally the Freezing is done by Resolve but sometimes the Prefix
8798 -- is not resolved, in which case the freezing must be done now.
8800 Freeze_Expression (P);
8802 -- Finally perform static evaluation on the attribute reference
8805 end Resolve_Attribute;
8807 --------------------------------
8808 -- Stream_Attribute_Available --
8809 --------------------------------
8811 function Stream_Attribute_Available
8813 Nam : TSS_Name_Type;
8814 Partial_View : Node_Id := Empty) return Boolean
8816 Etyp : Entity_Id := Typ;
8818 -- Start of processing for Stream_Attribute_Available
8821 -- We need some comments in this body ???
8823 if Has_Stream_Attribute_Definition (Typ, Nam) then
8827 if Is_Class_Wide_Type (Typ) then
8828 return not Is_Limited_Type (Typ)
8829 or else Stream_Attribute_Available (Etype (Typ), Nam);
8832 if Nam = TSS_Stream_Input
8833 and then Is_Abstract_Type (Typ)
8834 and then not Is_Class_Wide_Type (Typ)
8839 if not (Is_Limited_Type (Typ)
8840 or else (Present (Partial_View)
8841 and then Is_Limited_Type (Partial_View)))
8846 -- In Ada 2005, Input can invoke Read, and Output can invoke Write
8848 if Nam = TSS_Stream_Input
8849 and then Ada_Version >= Ada_2005
8850 and then Stream_Attribute_Available (Etyp, TSS_Stream_Read)
8854 elsif Nam = TSS_Stream_Output
8855 and then Ada_Version >= Ada_2005
8856 and then Stream_Attribute_Available (Etyp, TSS_Stream_Write)
8861 -- Case of Read and Write: check for attribute definition clause that
8862 -- applies to an ancestor type.
8864 while Etype (Etyp) /= Etyp loop
8865 Etyp := Etype (Etyp);
8867 if Has_Stream_Attribute_Definition (Etyp, Nam) then
8872 if Ada_Version < Ada_2005 then
8874 -- In Ada 95 mode, also consider a non-visible definition
8877 Btyp : constant Entity_Id := Implementation_Base_Type (Typ);
8880 and then Stream_Attribute_Available
8881 (Btyp, Nam, Partial_View => Typ);
8886 end Stream_Attribute_Available;