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_Formal_Restriction_On_Attribute;
293 -- Issue an error in formal mode because attribute N is allowed
295 procedure Check_Integer_Type;
296 -- Verify that prefix of attribute N is an integer type
298 procedure Check_Library_Unit;
299 -- Verify that prefix of attribute N is a library unit
301 procedure Check_Modular_Integer_Type;
302 -- Verify that prefix of attribute N is a modular integer type
304 procedure Check_Not_CPP_Type;
305 -- Check that P (the prefix of the attribute) is not an CPP type
306 -- for which no Ada predefined primitive is available.
308 procedure Check_Not_Incomplete_Type;
309 -- Check that P (the prefix of the attribute) is not an incomplete
310 -- type or a private type for which no full view has been given.
312 procedure Check_Object_Reference (P : Node_Id);
313 -- Check that P (the prefix of the attribute) is an object reference
315 procedure Check_Program_Unit;
316 -- Verify that prefix of attribute N is a program unit
318 procedure Check_Real_Type;
319 -- Verify that prefix of attribute N is fixed or float type
321 procedure Check_Scalar_Type;
322 -- Verify that prefix of attribute N is a scalar type
324 procedure Check_Standard_Prefix;
325 -- Verify that prefix of attribute N is package Standard
327 procedure Check_Stream_Attribute (Nam : TSS_Name_Type);
328 -- Validity checking for stream attribute. Nam is the TSS name of the
329 -- corresponding possible defined attribute function (e.g. for the
330 -- Read attribute, Nam will be TSS_Stream_Read).
332 procedure Check_PolyORB_Attribute;
333 -- Validity checking for PolyORB/DSA attribute
335 procedure Check_Task_Prefix;
336 -- Verify that prefix of attribute N is a task or task type
338 procedure Check_Type;
339 -- Verify that the prefix of attribute N is a type
341 procedure Check_Unit_Name (Nod : Node_Id);
342 -- Check that Nod is of the form of a library unit name, i.e that
343 -- it is an identifier, or a selected component whose prefix is
344 -- itself of the form of a library unit name. Note that this is
345 -- quite different from Check_Program_Unit, since it only checks
346 -- the syntactic form of the name, not the semantic identity. This
347 -- is because it is used with attributes (Elab_Body, Elab_Spec, and
348 -- UET_Address) which can refer to non-visible unit.
350 procedure Error_Attr (Msg : String; Error_Node : Node_Id);
351 pragma No_Return (Error_Attr);
352 procedure Error_Attr;
353 pragma No_Return (Error_Attr);
354 -- Posts error using Error_Msg_N at given node, sets type of attribute
355 -- node to Any_Type, and then raises Bad_Attribute to avoid any further
356 -- semantic processing. The message typically contains a % insertion
357 -- character which is replaced by the attribute name. The call with
358 -- no arguments is used when the caller has already generated the
359 -- required error messages.
361 procedure Error_Attr_P (Msg : String);
362 pragma No_Return (Error_Attr);
363 -- Like Error_Attr, but error is posted at the start of the prefix
365 procedure Standard_Attribute (Val : Int);
366 -- Used to process attributes whose prefix is package Standard which
367 -- yield values of type Universal_Integer. The attribute reference
368 -- node is rewritten with an integer literal of the given value.
370 procedure Unexpected_Argument (En : Node_Id);
371 -- Signal unexpected attribute argument (En is the argument)
373 procedure Validate_Non_Static_Attribute_Function_Call;
374 -- Called when processing an attribute that is a function call to a
375 -- non-static function, i.e. an attribute function that either takes
376 -- non-scalar arguments or returns a non-scalar result. Verifies that
377 -- such a call does not appear in a preelaborable context.
379 ------------------------------
380 -- Analyze_Access_Attribute --
381 ------------------------------
383 procedure Analyze_Access_Attribute is
384 Acc_Type : Entity_Id;
389 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id;
390 -- Build an access-to-object type whose designated type is DT,
391 -- and whose Ekind is appropriate to the attribute type. The
392 -- type that is constructed is returned as the result.
394 procedure Build_Access_Subprogram_Type (P : Node_Id);
395 -- Build an access to subprogram whose designated type is the type of
396 -- the prefix. If prefix is overloaded, so is the node itself. The
397 -- result is stored in Acc_Type.
399 function OK_Self_Reference return Boolean;
400 -- An access reference whose prefix is a type can legally appear
401 -- within an aggregate, where it is obtained by expansion of
402 -- a defaulted aggregate. The enclosing aggregate that contains
403 -- the self-referenced is flagged so that the self-reference can
404 -- be expanded into a reference to the target object (see exp_aggr).
406 ------------------------------
407 -- Build_Access_Object_Type --
408 ------------------------------
410 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id is
411 Typ : constant Entity_Id :=
413 (E_Access_Attribute_Type, Current_Scope, Loc, 'A');
415 Set_Etype (Typ, Typ);
417 Set_Associated_Node_For_Itype (Typ, N);
418 Set_Directly_Designated_Type (Typ, DT);
420 end Build_Access_Object_Type;
422 ----------------------------------
423 -- Build_Access_Subprogram_Type --
424 ----------------------------------
426 procedure Build_Access_Subprogram_Type (P : Node_Id) is
427 Index : Interp_Index;
430 procedure Check_Local_Access (E : Entity_Id);
431 -- Deal with possible access to local subprogram. If we have such
432 -- an access, we set a flag to kill all tracked values on any call
433 -- because this access value may be passed around, and any called
434 -- code might use it to access a local procedure which clobbers a
435 -- tracked value. If the scope is a loop or block, indicate that
436 -- value tracking is disabled for the enclosing subprogram.
438 function Get_Kind (E : Entity_Id) return Entity_Kind;
439 -- Distinguish between access to regular/protected subprograms
441 ------------------------
442 -- Check_Local_Access --
443 ------------------------
445 procedure Check_Local_Access (E : Entity_Id) is
447 if not Is_Library_Level_Entity (E) then
448 Set_Suppress_Value_Tracking_On_Call (Current_Scope);
449 Set_Suppress_Value_Tracking_On_Call
450 (Nearest_Dynamic_Scope (Current_Scope));
452 end Check_Local_Access;
458 function Get_Kind (E : Entity_Id) return Entity_Kind is
460 if Convention (E) = Convention_Protected then
461 return E_Access_Protected_Subprogram_Type;
463 return E_Access_Subprogram_Type;
467 -- Start of processing for Build_Access_Subprogram_Type
470 -- In the case of an access to subprogram, use the name of the
471 -- subprogram itself as the designated type. Type-checking in
472 -- this case compares the signatures of the designated types.
474 -- Note: This fragment of the tree is temporarily malformed
475 -- because the correct tree requires an E_Subprogram_Type entity
476 -- as the designated type. In most cases this designated type is
477 -- later overridden by the semantics with the type imposed by the
478 -- context during the resolution phase. In the specific case of
479 -- the expression Address!(Prim'Unrestricted_Access), used to
480 -- initialize slots of dispatch tables, this work will be done by
481 -- the expander (see Exp_Aggr).
483 -- The reason to temporarily add this kind of node to the tree
484 -- instead of a proper E_Subprogram_Type itype, is the following:
485 -- in case of errors found in the source file we report better
486 -- error messages. For example, instead of generating the
489 -- "expected access to subprogram with profile
490 -- defined at line X"
492 -- we currently generate:
494 -- "expected access to function Z defined at line X"
496 Set_Etype (N, Any_Type);
498 if not Is_Overloaded (P) then
499 Check_Local_Access (Entity (P));
501 if not Is_Intrinsic_Subprogram (Entity (P)) then
502 Acc_Type := Create_Itype (Get_Kind (Entity (P)), N);
503 Set_Is_Public (Acc_Type, False);
504 Set_Etype (Acc_Type, Acc_Type);
505 Set_Convention (Acc_Type, Convention (Entity (P)));
506 Set_Directly_Designated_Type (Acc_Type, Entity (P));
507 Set_Etype (N, Acc_Type);
508 Freeze_Before (N, Acc_Type);
512 Get_First_Interp (P, Index, It);
513 while Present (It.Nam) loop
514 Check_Local_Access (It.Nam);
516 if not Is_Intrinsic_Subprogram (It.Nam) then
517 Acc_Type := Create_Itype (Get_Kind (It.Nam), N);
518 Set_Is_Public (Acc_Type, False);
519 Set_Etype (Acc_Type, Acc_Type);
520 Set_Convention (Acc_Type, Convention (It.Nam));
521 Set_Directly_Designated_Type (Acc_Type, It.Nam);
522 Add_One_Interp (N, Acc_Type, Acc_Type);
523 Freeze_Before (N, Acc_Type);
526 Get_Next_Interp (Index, It);
530 -- Cannot be applied to intrinsic. Looking at the tests above,
531 -- the only way Etype (N) can still be set to Any_Type is if
532 -- Is_Intrinsic_Subprogram was True for some referenced entity.
534 if Etype (N) = Any_Type then
535 Error_Attr_P ("prefix of % attribute cannot be intrinsic");
537 end Build_Access_Subprogram_Type;
539 ----------------------
540 -- OK_Self_Reference --
541 ----------------------
543 function OK_Self_Reference return Boolean is
550 (Nkind (Par) = N_Component_Association
551 or else Nkind (Par) in N_Subexpr)
553 if Nkind_In (Par, N_Aggregate, N_Extension_Aggregate) then
554 if Etype (Par) = Typ then
555 Set_Has_Self_Reference (Par);
563 -- No enclosing aggregate, or not a self-reference
566 end OK_Self_Reference;
568 -- Start of processing for Analyze_Access_Attribute
571 Check_Formal_Restriction_On_Attribute;
574 if Nkind (P) = N_Character_Literal then
576 ("prefix of % attribute cannot be enumeration literal");
579 -- Case of access to subprogram
581 if Is_Entity_Name (P)
582 and then Is_Overloadable (Entity (P))
584 if Has_Pragma_Inline_Always (Entity (P)) then
586 ("prefix of % attribute cannot be Inline_Always subprogram");
589 if Aname = Name_Unchecked_Access then
590 Error_Attr ("attribute% cannot be applied to a subprogram", P);
593 -- Issue an error if the prefix denotes an eliminated subprogram
595 Check_For_Eliminated_Subprogram (P, Entity (P));
597 -- Check for obsolescent subprogram reference
599 Check_Obsolescent_2005_Entity (Entity (P), P);
601 -- Build the appropriate subprogram type
603 Build_Access_Subprogram_Type (P);
605 -- For unrestricted access, kill current values, since this
606 -- attribute allows a reference to a local subprogram that
607 -- could modify local variables to be passed out of scope
609 if Aname = Name_Unrestricted_Access then
611 -- Do not kill values on nodes initializing dispatch tables
612 -- slots. The construct Prim_Ptr!(Prim'Unrestricted_Access)
613 -- is currently generated by the expander only for this
614 -- purpose. Done to keep the quality of warnings currently
615 -- generated by the compiler (otherwise any declaration of
616 -- a tagged type cleans constant indications from its scope).
618 if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
619 and then (Etype (Parent (N)) = RTE (RE_Prim_Ptr)
621 Etype (Parent (N)) = RTE (RE_Size_Ptr))
622 and then Is_Dispatching_Operation
623 (Directly_Designated_Type (Etype (N)))
633 -- Component is an operation of a protected type
635 elsif Nkind (P) = N_Selected_Component
636 and then Is_Overloadable (Entity (Selector_Name (P)))
638 if Ekind (Entity (Selector_Name (P))) = E_Entry then
639 Error_Attr_P ("prefix of % attribute must be subprogram");
642 Build_Access_Subprogram_Type (Selector_Name (P));
646 -- Deal with incorrect reference to a type, but note that some
647 -- accesses are allowed: references to the current type instance,
648 -- or in Ada 2005 self-referential pointer in a default-initialized
651 if Is_Entity_Name (P) then
654 -- The reference may appear in an aggregate that has been expanded
655 -- into a loop. Locate scope of type definition, if any.
657 Scop := Current_Scope;
658 while Ekind (Scop) = E_Loop loop
659 Scop := Scope (Scop);
662 if Is_Type (Typ) then
664 -- OK if we are within the scope of a limited type
665 -- let's mark the component as having per object constraint
667 if Is_Anonymous_Tagged_Base (Scop, Typ) then
675 Q : Node_Id := Parent (N);
679 and then Nkind (Q) /= N_Component_Declaration
685 Set_Has_Per_Object_Constraint
686 (Defining_Identifier (Q), True);
690 if Nkind (P) = N_Expanded_Name then
692 ("current instance prefix must be a direct name", P);
695 -- If a current instance attribute appears in a component
696 -- constraint it must appear alone; other contexts (spec-
697 -- expressions, within a task body) are not subject to this
700 if not In_Spec_Expression
701 and then not Has_Completion (Scop)
703 Nkind_In (Parent (N), N_Discriminant_Association,
704 N_Index_Or_Discriminant_Constraint)
707 ("current instance attribute must appear alone", N);
710 if Is_CPP_Class (Root_Type (Typ)) then
712 ("?current instance unsupported for derivations of "
713 & "'C'P'P types", N);
716 -- OK if we are in initialization procedure for the type
717 -- in question, in which case the reference to the type
718 -- is rewritten as a reference to the current object.
720 elsif Ekind (Scop) = E_Procedure
721 and then Is_Init_Proc (Scop)
722 and then Etype (First_Formal (Scop)) = Typ
725 Make_Attribute_Reference (Loc,
726 Prefix => Make_Identifier (Loc, Name_uInit),
727 Attribute_Name => Name_Unrestricted_Access));
731 -- OK if a task type, this test needs sharpening up ???
733 elsif Is_Task_Type (Typ) then
736 -- OK if self-reference in an aggregate in Ada 2005, and
737 -- the reference comes from a copied default expression.
739 -- Note that we check legality of self-reference even if the
740 -- expression comes from source, e.g. when a single component
741 -- association in an aggregate has a box association.
743 elsif Ada_Version >= Ada_2005
744 and then OK_Self_Reference
748 -- OK if reference to current instance of a protected object
750 elsif Is_Protected_Self_Reference (P) then
753 -- Otherwise we have an error case
756 Error_Attr ("% attribute cannot be applied to type", P);
762 -- If we fall through, we have a normal access to object case.
763 -- Unrestricted_Access is legal wherever an allocator would be
764 -- legal, so its Etype is set to E_Allocator. The expected type
765 -- of the other attributes is a general access type, and therefore
766 -- we label them with E_Access_Attribute_Type.
768 if not Is_Overloaded (P) then
769 Acc_Type := Build_Access_Object_Type (P_Type);
770 Set_Etype (N, Acc_Type);
773 Index : Interp_Index;
776 Set_Etype (N, Any_Type);
777 Get_First_Interp (P, Index, It);
778 while Present (It.Typ) loop
779 Acc_Type := Build_Access_Object_Type (It.Typ);
780 Add_One_Interp (N, Acc_Type, Acc_Type);
781 Get_Next_Interp (Index, It);
786 -- Special cases when we can find a prefix that is an entity name
795 if Is_Entity_Name (PP) then
798 -- If we have an access to an object, and the attribute
799 -- comes from source, then set the object as potentially
800 -- source modified. We do this because the resulting access
801 -- pointer can be used to modify the variable, and we might
802 -- not detect this, leading to some junk warnings.
804 Set_Never_Set_In_Source (Ent, False);
806 -- Mark entity as address taken, and kill current values
808 Set_Address_Taken (Ent);
809 Kill_Current_Values (Ent);
812 elsif Nkind_In (PP, N_Selected_Component,
823 -- Check for aliased view unless unrestricted case. We allow a
824 -- nonaliased prefix when within an instance because the prefix may
825 -- have been a tagged formal object, which is defined to be aliased
826 -- even when the actual might not be (other instance cases will have
827 -- been caught in the generic). Similarly, within an inlined body we
828 -- know that the attribute is legal in the original subprogram, and
829 -- therefore legal in the expansion.
831 if Aname /= Name_Unrestricted_Access
832 and then not Is_Aliased_View (P)
833 and then not In_Instance
834 and then not In_Inlined_Body
836 Error_Attr_P ("prefix of % attribute must be aliased");
838 end Analyze_Access_Attribute;
840 ---------------------------------
841 -- Bad_Attribute_For_Predicate --
842 ---------------------------------
844 procedure Bad_Attribute_For_Predicate is
846 if Comes_From_Source (N) then
847 Error_Msg_Name_1 := Aname;
848 Bad_Predicated_Subtype_Use
849 ("type& has predicates, attribute % not allowed", N, P_Type);
851 end Bad_Attribute_For_Predicate;
853 --------------------------------
854 -- Check_Array_Or_Scalar_Type --
855 --------------------------------
857 procedure Check_Array_Or_Scalar_Type is
861 -- Dimension number for array attributes
864 -- Case of string literal or string literal subtype. These cases
865 -- cannot arise from legal Ada code, but the expander is allowed
866 -- to generate them. They require special handling because string
867 -- literal subtypes do not have standard bounds (the whole idea
868 -- of these subtypes is to avoid having to generate the bounds)
870 if Ekind (P_Type) = E_String_Literal_Subtype then
871 Set_Etype (N, Etype (First_Index (P_Base_Type)));
876 elsif Is_Scalar_Type (P_Type) then
880 Error_Attr ("invalid argument in % attribute", E1);
882 Set_Etype (N, P_Base_Type);
886 -- The following is a special test to allow 'First to apply to
887 -- private scalar types if the attribute comes from generated
888 -- code. This occurs in the case of Normalize_Scalars code.
890 elsif Is_Private_Type (P_Type)
891 and then Present (Full_View (P_Type))
892 and then Is_Scalar_Type (Full_View (P_Type))
893 and then not Comes_From_Source (N)
895 Set_Etype (N, Implementation_Base_Type (P_Type));
897 -- Array types other than string literal subtypes handled above
902 -- We know prefix is an array type, or the name of an array
903 -- object, and that the expression, if present, is static
904 -- and within the range of the dimensions of the type.
906 pragma Assert (Is_Array_Type (P_Type));
907 Index := First_Index (P_Base_Type);
911 -- First dimension assumed
913 Set_Etype (N, Base_Type (Etype (Index)));
916 D := UI_To_Int (Intval (E1));
918 for J in 1 .. D - 1 loop
922 Set_Etype (N, Base_Type (Etype (Index)));
923 Set_Etype (E1, Standard_Integer);
926 end Check_Array_Or_Scalar_Type;
928 ----------------------
929 -- Check_Array_Type --
930 ----------------------
932 procedure Check_Array_Type is
934 -- Dimension number for array attributes
937 -- If the type is a string literal type, then this must be generated
938 -- internally, and no further check is required on its legality.
940 if Ekind (P_Type) = E_String_Literal_Subtype then
943 -- If the type is a composite, it is an illegal aggregate, no point
946 elsif P_Type = Any_Composite then
950 -- Normal case of array type or subtype
952 Check_Either_E0_Or_E1;
955 if Is_Array_Type (P_Type) then
956 if not Is_Constrained (P_Type)
957 and then Is_Entity_Name (P)
958 and then Is_Type (Entity (P))
960 -- Note: we do not call Error_Attr here, since we prefer to
961 -- continue, using the relevant index type of the array,
962 -- even though it is unconstrained. This gives better error
963 -- recovery behavior.
965 Error_Msg_Name_1 := Aname;
967 ("prefix for % attribute must be constrained array", P);
970 D := Number_Dimensions (P_Type);
973 if Is_Private_Type (P_Type) then
974 Error_Attr_P ("prefix for % attribute may not be private type");
976 elsif Is_Access_Type (P_Type)
977 and then Is_Array_Type (Designated_Type (P_Type))
978 and then Is_Entity_Name (P)
979 and then Is_Type (Entity (P))
981 Error_Attr_P ("prefix of % attribute cannot be access type");
983 elsif Attr_Id = Attribute_First
985 Attr_Id = Attribute_Last
987 Error_Attr ("invalid prefix for % attribute", P);
990 Error_Attr_P ("prefix for % attribute must be array");
995 Resolve (E1, Any_Integer);
996 Set_Etype (E1, Standard_Integer);
998 if not Is_Static_Expression (E1)
999 or else Raises_Constraint_Error (E1)
1001 Flag_Non_Static_Expr
1002 ("expression for dimension must be static!", E1);
1005 elsif UI_To_Int (Expr_Value (E1)) > D
1006 or else UI_To_Int (Expr_Value (E1)) < 1
1008 Error_Attr ("invalid dimension number for array type", E1);
1012 if (Style_Check and Style_Check_Array_Attribute_Index)
1013 and then Comes_From_Source (N)
1015 Style.Check_Array_Attribute_Index (N, E1, D);
1017 end Check_Array_Type;
1019 -------------------------
1020 -- Check_Asm_Attribute --
1021 -------------------------
1023 procedure Check_Asm_Attribute is
1028 -- Check first argument is static string expression
1030 Analyze_And_Resolve (E1, Standard_String);
1032 if Etype (E1) = Any_Type then
1035 elsif not Is_OK_Static_Expression (E1) then
1036 Flag_Non_Static_Expr
1037 ("constraint argument must be static string expression!", E1);
1041 -- Check second argument is right type
1043 Analyze_And_Resolve (E2, Entity (P));
1045 -- Note: that is all we need to do, we don't need to check
1046 -- that it appears in a correct context. The Ada type system
1047 -- will do that for us.
1049 end Check_Asm_Attribute;
1051 ---------------------
1052 -- Check_Component --
1053 ---------------------
1055 procedure Check_Component is
1059 if Nkind (P) /= N_Selected_Component
1061 (Ekind (Entity (Selector_Name (P))) /= E_Component
1063 Ekind (Entity (Selector_Name (P))) /= E_Discriminant)
1065 Error_Attr_P ("prefix for % attribute must be selected component");
1067 end Check_Component;
1069 ------------------------------------
1070 -- Check_Decimal_Fixed_Point_Type --
1071 ------------------------------------
1073 procedure Check_Decimal_Fixed_Point_Type is
1077 if not Is_Decimal_Fixed_Point_Type (P_Type) then
1078 Error_Attr_P ("prefix of % attribute must be decimal type");
1080 end Check_Decimal_Fixed_Point_Type;
1082 -----------------------
1083 -- Check_Dereference --
1084 -----------------------
1086 procedure Check_Dereference is
1089 -- Case of a subtype mark
1091 if Is_Entity_Name (P)
1092 and then Is_Type (Entity (P))
1097 -- Case of an expression
1101 if Is_Access_Type (P_Type) then
1103 -- If there is an implicit dereference, then we must freeze
1104 -- the designated type of the access type, since the type of
1105 -- the referenced array is this type (see AI95-00106).
1107 -- As done elsewhere, freezing must not happen when pre-analyzing
1108 -- a pre- or postcondition or a default value for an object or
1109 -- for a formal parameter.
1111 if not In_Spec_Expression then
1112 Freeze_Before (N, Designated_Type (P_Type));
1116 Make_Explicit_Dereference (Sloc (P),
1117 Prefix => Relocate_Node (P)));
1119 Analyze_And_Resolve (P);
1120 P_Type := Etype (P);
1122 if P_Type = Any_Type then
1123 raise Bad_Attribute;
1126 P_Base_Type := Base_Type (P_Type);
1128 end Check_Dereference;
1130 -------------------------
1131 -- Check_Discrete_Type --
1132 -------------------------
1134 procedure Check_Discrete_Type is
1138 if not Is_Discrete_Type (P_Type) then
1139 Error_Attr_P ("prefix of % attribute must be discrete type");
1141 end Check_Discrete_Type;
1147 procedure Check_E0 is
1149 if Present (E1) then
1150 Unexpected_Argument (E1);
1158 procedure Check_E1 is
1160 Check_Either_E0_Or_E1;
1164 -- Special-case attributes that are functions and that appear as
1165 -- the prefix of another attribute. Error is posted on parent.
1167 if Nkind (Parent (N)) = N_Attribute_Reference
1168 and then (Attribute_Name (Parent (N)) = Name_Address
1170 Attribute_Name (Parent (N)) = Name_Code_Address
1172 Attribute_Name (Parent (N)) = Name_Access)
1174 Error_Msg_Name_1 := Attribute_Name (Parent (N));
1175 Error_Msg_N ("illegal prefix for % attribute", Parent (N));
1176 Set_Etype (Parent (N), Any_Type);
1177 Set_Entity (Parent (N), Any_Type);
1178 raise Bad_Attribute;
1181 Error_Attr ("missing argument for % attribute", N);
1190 procedure Check_E2 is
1193 Error_Attr ("missing arguments for % attribute (2 required)", N);
1195 Error_Attr ("missing argument for % attribute (2 required)", N);
1199 ---------------------------
1200 -- Check_Either_E0_Or_E1 --
1201 ---------------------------
1203 procedure Check_Either_E0_Or_E1 is
1205 if Present (E2) then
1206 Unexpected_Argument (E2);
1208 end Check_Either_E0_Or_E1;
1210 ----------------------
1211 -- Check_Enum_Image --
1212 ----------------------
1214 procedure Check_Enum_Image is
1217 if Is_Enumeration_Type (P_Base_Type) then
1218 Lit := First_Literal (P_Base_Type);
1219 while Present (Lit) loop
1220 Set_Referenced (Lit);
1224 end Check_Enum_Image;
1226 ----------------------------
1227 -- Check_Fixed_Point_Type --
1228 ----------------------------
1230 procedure Check_Fixed_Point_Type is
1234 if not Is_Fixed_Point_Type (P_Type) then
1235 Error_Attr_P ("prefix of % attribute must be fixed point type");
1237 end Check_Fixed_Point_Type;
1239 ------------------------------
1240 -- Check_Fixed_Point_Type_0 --
1241 ------------------------------
1243 procedure Check_Fixed_Point_Type_0 is
1245 Check_Fixed_Point_Type;
1247 end Check_Fixed_Point_Type_0;
1249 -------------------------------
1250 -- Check_Floating_Point_Type --
1251 -------------------------------
1253 procedure Check_Floating_Point_Type is
1257 if not Is_Floating_Point_Type (P_Type) then
1258 Error_Attr_P ("prefix of % attribute must be float type");
1260 end Check_Floating_Point_Type;
1262 ---------------------------------
1263 -- Check_Floating_Point_Type_0 --
1264 ---------------------------------
1266 procedure Check_Floating_Point_Type_0 is
1268 Check_Floating_Point_Type;
1270 end Check_Floating_Point_Type_0;
1272 ---------------------------------
1273 -- Check_Floating_Point_Type_1 --
1274 ---------------------------------
1276 procedure Check_Floating_Point_Type_1 is
1278 Check_Floating_Point_Type;
1280 end Check_Floating_Point_Type_1;
1282 ---------------------------------
1283 -- Check_Floating_Point_Type_2 --
1284 ---------------------------------
1286 procedure Check_Floating_Point_Type_2 is
1288 Check_Floating_Point_Type;
1290 end Check_Floating_Point_Type_2;
1292 -------------------------------------------
1293 -- Check_Formal_Restriction_On_Attribute --
1294 -------------------------------------------
1296 procedure Check_Formal_Restriction_On_Attribute is
1298 Error_Msg_Name_1 := Aname;
1299 Check_Formal_Restriction ("attribute % is not allowed", P);
1300 end Check_Formal_Restriction_On_Attribute;
1302 ------------------------
1303 -- Check_Integer_Type --
1304 ------------------------
1306 procedure Check_Integer_Type is
1310 if not Is_Integer_Type (P_Type) then
1311 Error_Attr_P ("prefix of % attribute must be integer type");
1313 end Check_Integer_Type;
1315 ------------------------
1316 -- Check_Library_Unit --
1317 ------------------------
1319 procedure Check_Library_Unit is
1321 if not Is_Compilation_Unit (Entity (P)) then
1322 Error_Attr_P ("prefix of % attribute must be library unit");
1324 end Check_Library_Unit;
1326 --------------------------------
1327 -- Check_Modular_Integer_Type --
1328 --------------------------------
1330 procedure Check_Modular_Integer_Type is
1334 if not Is_Modular_Integer_Type (P_Type) then
1336 ("prefix of % attribute must be modular integer type");
1338 end Check_Modular_Integer_Type;
1340 ------------------------
1341 -- Check_Not_CPP_Type --
1342 ------------------------
1344 procedure Check_Not_CPP_Type is
1346 if Is_Tagged_Type (Etype (P))
1347 and then Convention (Etype (P)) = Convention_CPP
1348 and then Is_CPP_Class (Root_Type (Etype (P)))
1351 ("invalid use of % attribute with 'C'P'P tagged type");
1353 end Check_Not_CPP_Type;
1355 -------------------------------
1356 -- Check_Not_Incomplete_Type --
1357 -------------------------------
1359 procedure Check_Not_Incomplete_Type is
1364 -- Ada 2005 (AI-50217, AI-326): If the prefix is an explicit
1365 -- dereference we have to check wrong uses of incomplete types
1366 -- (other wrong uses are checked at their freezing point).
1368 -- Example 1: Limited-with
1370 -- limited with Pkg;
1372 -- type Acc is access Pkg.T;
1374 -- S : Integer := X.all'Size; -- ERROR
1377 -- Example 2: Tagged incomplete
1379 -- type T is tagged;
1380 -- type Acc is access all T;
1382 -- S : constant Integer := X.all'Size; -- ERROR
1383 -- procedure Q (Obj : Integer := X.all'Alignment); -- ERROR
1385 if Ada_Version >= Ada_2005
1386 and then Nkind (P) = N_Explicit_Dereference
1389 while Nkind (E) = N_Explicit_Dereference loop
1395 if From_With_Type (Typ) then
1397 ("prefix of % attribute cannot be an incomplete type");
1400 if Is_Access_Type (Typ) then
1401 Typ := Directly_Designated_Type (Typ);
1404 if Is_Class_Wide_Type (Typ) then
1405 Typ := Root_Type (Typ);
1408 -- A legal use of a shadow entity occurs only when the unit
1409 -- where the non-limited view resides is imported via a regular
1410 -- with clause in the current body. Such references to shadow
1411 -- entities may occur in subprogram formals.
1413 if Is_Incomplete_Type (Typ)
1414 and then From_With_Type (Typ)
1415 and then Present (Non_Limited_View (Typ))
1416 and then Is_Legal_Shadow_Entity_In_Body (Typ)
1418 Typ := Non_Limited_View (Typ);
1421 if Ekind (Typ) = E_Incomplete_Type
1422 and then No (Full_View (Typ))
1425 ("prefix of % attribute cannot be an incomplete type");
1430 if not Is_Entity_Name (P)
1431 or else not Is_Type (Entity (P))
1432 or else In_Spec_Expression
1436 Check_Fully_Declared (P_Type, P);
1438 end Check_Not_Incomplete_Type;
1440 ----------------------------
1441 -- Check_Object_Reference --
1442 ----------------------------
1444 procedure Check_Object_Reference (P : Node_Id) is
1448 -- If we need an object, and we have a prefix that is the name of
1449 -- a function entity, convert it into a function call.
1451 if Is_Entity_Name (P)
1452 and then Ekind (Entity (P)) = E_Function
1454 Rtyp := Etype (Entity (P));
1457 Make_Function_Call (Sloc (P),
1458 Name => Relocate_Node (P)));
1460 Analyze_And_Resolve (P, Rtyp);
1462 -- Otherwise we must have an object reference
1464 elsif not Is_Object_Reference (P) then
1465 Error_Attr_P ("prefix of % attribute must be object");
1467 end Check_Object_Reference;
1469 ----------------------------
1470 -- Check_PolyORB_Attribute --
1471 ----------------------------
1473 procedure Check_PolyORB_Attribute is
1475 Validate_Non_Static_Attribute_Function_Call;
1480 if Get_PCS_Name /= Name_PolyORB_DSA then
1482 ("attribute% requires the 'Poly'O'R'B 'P'C'S", N);
1484 end Check_PolyORB_Attribute;
1486 ------------------------
1487 -- Check_Program_Unit --
1488 ------------------------
1490 procedure Check_Program_Unit is
1492 if Is_Entity_Name (P) then
1494 K : constant Entity_Kind := Ekind (Entity (P));
1495 T : constant Entity_Id := Etype (Entity (P));
1498 if K in Subprogram_Kind
1499 or else K in Task_Kind
1500 or else K in Protected_Kind
1501 or else K = E_Package
1502 or else K in Generic_Unit_Kind
1503 or else (K = E_Variable
1507 Is_Protected_Type (T)))
1514 Error_Attr_P ("prefix of % attribute must be program unit");
1515 end Check_Program_Unit;
1517 ---------------------
1518 -- Check_Real_Type --
1519 ---------------------
1521 procedure Check_Real_Type is
1525 if not Is_Real_Type (P_Type) then
1526 Error_Attr_P ("prefix of % attribute must be real type");
1528 end Check_Real_Type;
1530 -----------------------
1531 -- Check_Scalar_Type --
1532 -----------------------
1534 procedure Check_Scalar_Type is
1538 if not Is_Scalar_Type (P_Type) then
1539 Error_Attr_P ("prefix of % attribute must be scalar type");
1541 end Check_Scalar_Type;
1543 ---------------------------
1544 -- Check_Standard_Prefix --
1545 ---------------------------
1547 procedure Check_Standard_Prefix is
1551 if Nkind (P) /= N_Identifier
1552 or else Chars (P) /= Name_Standard
1554 Error_Attr ("only allowed prefix for % attribute is Standard", P);
1556 end Check_Standard_Prefix;
1558 ----------------------------
1559 -- Check_Stream_Attribute --
1560 ----------------------------
1562 procedure Check_Stream_Attribute (Nam : TSS_Name_Type) is
1566 In_Shared_Var_Procs : Boolean;
1567 -- True when compiling the body of System.Shared_Storage.
1568 -- Shared_Var_Procs. For this runtime package (always compiled in
1569 -- GNAT mode), we allow stream attributes references for limited
1570 -- types for the case where shared passive objects are implemented
1571 -- using stream attributes, which is the default in GNAT's persistent
1572 -- storage implementation.
1575 Validate_Non_Static_Attribute_Function_Call;
1577 -- With the exception of 'Input, Stream attributes are procedures,
1578 -- and can only appear at the position of procedure calls. We check
1579 -- for this here, before they are rewritten, to give a more precise
1582 if Nam = TSS_Stream_Input then
1585 elsif Is_List_Member (N)
1586 and then not Nkind_In (Parent (N), N_Procedure_Call_Statement,
1593 ("invalid context for attribute%, which is a procedure", N);
1597 Btyp := Implementation_Base_Type (P_Type);
1599 -- Stream attributes not allowed on limited types unless the
1600 -- attribute reference was generated by the expander (in which
1601 -- case the underlying type will be used, as described in Sinfo),
1602 -- or the attribute was specified explicitly for the type itself
1603 -- or one of its ancestors (taking visibility rules into account if
1604 -- in Ada 2005 mode), or a pragma Stream_Convert applies to Btyp
1605 -- (with no visibility restriction).
1608 Gen_Body : constant Node_Id := Enclosing_Generic_Body (N);
1610 if Present (Gen_Body) then
1611 In_Shared_Var_Procs :=
1612 Is_RTE (Corresponding_Spec (Gen_Body), RE_Shared_Var_Procs);
1614 In_Shared_Var_Procs := False;
1618 if (Comes_From_Source (N)
1619 and then not (In_Shared_Var_Procs or In_Instance))
1620 and then not Stream_Attribute_Available (P_Type, Nam)
1621 and then not Has_Rep_Pragma (Btyp, Name_Stream_Convert)
1623 Error_Msg_Name_1 := Aname;
1625 if Is_Limited_Type (P_Type) then
1627 ("limited type& has no% attribute", P, P_Type);
1628 Explain_Limited_Type (P_Type, P);
1631 ("attribute% for type& is not available", P, P_Type);
1635 -- Check restriction violations
1637 -- First check the No_Streams restriction, which prohibits the use
1638 -- of explicit stream attributes in the source program. We do not
1639 -- prevent the occurrence of stream attributes in generated code,
1640 -- for instance those generated implicitly for dispatching purposes.
1642 if Comes_From_Source (N) then
1643 Check_Restriction (No_Streams, P);
1646 -- Check special case of Exception_Id and Exception_Occurrence which
1647 -- are not allowed for restriction No_Exception_Registration.
1649 if Restriction_Check_Required (No_Exception_Registration)
1650 and then (Is_RTE (P_Type, RE_Exception_Id)
1652 Is_RTE (P_Type, RE_Exception_Occurrence))
1654 Check_Restriction (No_Exception_Registration, P);
1657 -- Here we must check that the first argument is an access type
1658 -- that is compatible with Ada.Streams.Root_Stream_Type'Class.
1660 Analyze_And_Resolve (E1);
1663 -- Note: the double call to Root_Type here is needed because the
1664 -- root type of a class-wide type is the corresponding type (e.g.
1665 -- X for X'Class, and we really want to go to the root.)
1667 if not Is_Access_Type (Etyp)
1668 or else Root_Type (Root_Type (Designated_Type (Etyp))) /=
1669 RTE (RE_Root_Stream_Type)
1672 ("expected access to Ada.Streams.Root_Stream_Type''Class", E1);
1675 -- Check that the second argument is of the right type if there is
1676 -- one (the Input attribute has only one argument so this is skipped)
1678 if Present (E2) then
1681 if Nam = TSS_Stream_Read
1682 and then not Is_OK_Variable_For_Out_Formal (E2)
1685 ("second argument of % attribute must be a variable", E2);
1688 Resolve (E2, P_Type);
1692 end Check_Stream_Attribute;
1694 -----------------------
1695 -- Check_Task_Prefix --
1696 -----------------------
1698 procedure Check_Task_Prefix is
1702 -- Ada 2005 (AI-345): Attribute 'Terminated can be applied to
1703 -- task interface class-wide types.
1705 if Is_Task_Type (Etype (P))
1706 or else (Is_Access_Type (Etype (P))
1707 and then Is_Task_Type (Designated_Type (Etype (P))))
1708 or else (Ada_Version >= Ada_2005
1709 and then Ekind (Etype (P)) = E_Class_Wide_Type
1710 and then Is_Interface (Etype (P))
1711 and then Is_Task_Interface (Etype (P)))
1716 if Ada_Version >= Ada_2005 then
1718 ("prefix of % attribute must be a task or a task " &
1719 "interface class-wide object");
1722 Error_Attr_P ("prefix of % attribute must be a task");
1725 end Check_Task_Prefix;
1731 -- The possibilities are an entity name denoting a type, or an
1732 -- attribute reference that denotes a type (Base or Class). If
1733 -- the type is incomplete, replace it with its full view.
1735 procedure Check_Type is
1737 if not Is_Entity_Name (P)
1738 or else not Is_Type (Entity (P))
1740 Error_Attr_P ("prefix of % attribute must be a type");
1742 elsif Is_Protected_Self_Reference (P) then
1744 ("prefix of % attribute denotes current instance "
1745 & "(RM 9.4(21/2))");
1747 elsif Ekind (Entity (P)) = E_Incomplete_Type
1748 and then Present (Full_View (Entity (P)))
1750 P_Type := Full_View (Entity (P));
1751 Set_Entity (P, P_Type);
1755 ---------------------
1756 -- Check_Unit_Name --
1757 ---------------------
1759 procedure Check_Unit_Name (Nod : Node_Id) is
1761 if Nkind (Nod) = N_Identifier then
1764 elsif Nkind (Nod) = N_Selected_Component then
1765 Check_Unit_Name (Prefix (Nod));
1767 if Nkind (Selector_Name (Nod)) = N_Identifier then
1772 Error_Attr ("argument for % attribute must be unit name", P);
1773 end Check_Unit_Name;
1779 procedure Error_Attr is
1781 Set_Etype (N, Any_Type);
1782 Set_Entity (N, Any_Type);
1783 raise Bad_Attribute;
1786 procedure Error_Attr (Msg : String; Error_Node : Node_Id) is
1788 Error_Msg_Name_1 := Aname;
1789 Error_Msg_N (Msg, Error_Node);
1797 procedure Error_Attr_P (Msg : String) is
1799 Error_Msg_Name_1 := Aname;
1800 Error_Msg_F (Msg, P);
1804 ----------------------------
1805 -- Legal_Formal_Attribute --
1806 ----------------------------
1808 procedure Legal_Formal_Attribute is
1812 if not Is_Entity_Name (P)
1813 or else not Is_Type (Entity (P))
1815 Error_Attr_P ("prefix of % attribute must be generic type");
1817 elsif Is_Generic_Actual_Type (Entity (P))
1819 or else In_Inlined_Body
1823 elsif Is_Generic_Type (Entity (P)) then
1824 if not Is_Indefinite_Subtype (Entity (P)) then
1826 ("prefix of % attribute must be indefinite generic type");
1831 ("prefix of % attribute must be indefinite generic type");
1834 Set_Etype (N, Standard_Boolean);
1835 end Legal_Formal_Attribute;
1837 ------------------------
1838 -- Standard_Attribute --
1839 ------------------------
1841 procedure Standard_Attribute (Val : Int) is
1843 Check_Standard_Prefix;
1844 Rewrite (N, Make_Integer_Literal (Loc, Val));
1846 end Standard_Attribute;
1848 -------------------------
1849 -- Unexpected Argument --
1850 -------------------------
1852 procedure Unexpected_Argument (En : Node_Id) is
1854 Error_Attr ("unexpected argument for % attribute", En);
1855 end Unexpected_Argument;
1857 -------------------------------------------------
1858 -- Validate_Non_Static_Attribute_Function_Call --
1859 -------------------------------------------------
1861 -- This function should be moved to Sem_Dist ???
1863 procedure Validate_Non_Static_Attribute_Function_Call is
1865 if In_Preelaborated_Unit
1866 and then not In_Subprogram_Or_Concurrent_Unit
1868 Flag_Non_Static_Expr
1869 ("non-static function call in preelaborated unit!", N);
1871 end Validate_Non_Static_Attribute_Function_Call;
1873 -----------------------------------------------
1874 -- Start of Processing for Analyze_Attribute --
1875 -----------------------------------------------
1878 -- Immediate return if unrecognized attribute (already diagnosed
1879 -- by parser, so there is nothing more that we need to do)
1881 if not Is_Attribute_Name (Aname) then
1882 raise Bad_Attribute;
1885 -- Deal with Ada 83 issues
1887 if Comes_From_Source (N) then
1888 if not Attribute_83 (Attr_Id) then
1889 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1890 Error_Msg_Name_1 := Aname;
1891 Error_Msg_N ("(Ada 83) attribute% is not standard?", N);
1894 if Attribute_Impl_Def (Attr_Id) then
1895 Check_Restriction (No_Implementation_Attributes, N);
1900 -- Deal with Ada 2005 issues
1902 if Attribute_05 (Attr_Id) and then Ada_Version <= Ada_95 then
1903 Check_Restriction (No_Implementation_Attributes, N);
1906 -- Remote access to subprogram type access attribute reference needs
1907 -- unanalyzed copy for tree transformation. The analyzed copy is used
1908 -- for its semantic information (whether prefix is a remote subprogram
1909 -- name), the unanalyzed copy is used to construct new subtree rooted
1910 -- with N_Aggregate which represents a fat pointer aggregate.
1912 if Aname = Name_Access then
1913 Discard_Node (Copy_Separate_Tree (N));
1916 -- Analyze prefix and exit if error in analysis. If the prefix is an
1917 -- incomplete type, use full view if available. Note that there are
1918 -- some attributes for which we do not analyze the prefix, since the
1919 -- prefix is not a normal name.
1921 if Aname /= Name_Elab_Body
1923 Aname /= Name_Elab_Spec
1925 Aname /= Name_UET_Address
1927 Aname /= Name_Enabled
1930 P_Type := Etype (P);
1932 if Is_Entity_Name (P)
1933 and then Present (Entity (P))
1934 and then Is_Type (Entity (P))
1936 if Ekind (Entity (P)) = E_Incomplete_Type then
1937 P_Type := Get_Full_View (P_Type);
1938 Set_Entity (P, P_Type);
1939 Set_Etype (P, P_Type);
1941 elsif Entity (P) = Current_Scope
1942 and then Is_Record_Type (Entity (P))
1944 -- Use of current instance within the type. Verify that if the
1945 -- attribute appears within a constraint, it yields an access
1946 -- type, other uses are illegal.
1954 and then Nkind (Parent (Par)) /= N_Component_Definition
1956 Par := Parent (Par);
1960 and then Nkind (Par) = N_Subtype_Indication
1962 if Attr_Id /= Attribute_Access
1963 and then Attr_Id /= Attribute_Unchecked_Access
1964 and then Attr_Id /= Attribute_Unrestricted_Access
1967 ("in a constraint the current instance can only"
1968 & " be used with an access attribute", N);
1975 if P_Type = Any_Type then
1976 raise Bad_Attribute;
1979 P_Base_Type := Base_Type (P_Type);
1982 -- Analyze expressions that may be present, exiting if an error occurs
1989 E1 := First (Exprs);
1992 -- Check for missing/bad expression (result of previous error)
1994 if No (E1) or else Etype (E1) = Any_Type then
1995 raise Bad_Attribute;
2000 if Present (E2) then
2003 if Etype (E2) = Any_Type then
2004 raise Bad_Attribute;
2007 if Present (Next (E2)) then
2008 Unexpected_Argument (Next (E2));
2013 -- Ada 2005 (AI-345): Ensure that the compiler gives exactly the current
2014 -- output compiling in Ada 95 mode for the case of ambiguous prefixes.
2016 if Ada_Version < Ada_2005
2017 and then Is_Overloaded (P)
2018 and then Aname /= Name_Access
2019 and then Aname /= Name_Address
2020 and then Aname /= Name_Code_Address
2021 and then Aname /= Name_Count
2022 and then Aname /= Name_Result
2023 and then Aname /= Name_Unchecked_Access
2025 Error_Attr ("ambiguous prefix for % attribute", P);
2027 elsif Ada_Version >= Ada_2005
2028 and then Is_Overloaded (P)
2029 and then Aname /= Name_Access
2030 and then Aname /= Name_Address
2031 and then Aname /= Name_Code_Address
2032 and then Aname /= Name_Result
2033 and then Aname /= Name_Unchecked_Access
2035 -- Ada 2005 (AI-345): Since protected and task types have primitive
2036 -- entry wrappers, the attributes Count, Caller and AST_Entry require
2039 if Ada_Version >= Ada_2005
2040 and then (Aname = Name_Count
2041 or else Aname = Name_Caller
2042 or else Aname = Name_AST_Entry)
2045 Count : Natural := 0;
2050 Get_First_Interp (P, I, It);
2051 while Present (It.Nam) loop
2052 if Comes_From_Source (It.Nam) then
2058 Get_Next_Interp (I, It);
2062 Error_Attr ("ambiguous prefix for % attribute", P);
2064 Set_Is_Overloaded (P, False);
2069 Error_Attr ("ambiguous prefix for % attribute", P);
2073 -- In SPARK or ALFA, attributes of private types are only allowed if
2074 -- the full type declaration is visible.
2076 if Formal_Verification_Mode
2077 and then Comes_From_Source (Original_Node (N))
2078 and then Is_Entity_Name (P)
2079 and then Is_Type (Entity (P))
2080 and then Is_Private_Type (P_Type)
2081 and then not In_Open_Scopes (Scope (P_Type))
2082 and then not In_Spec_Expression
2085 ("|~~invisible attribute of}", N, First_Subtype (P_Type));
2088 -- Remaining processing depends on attribute
2096 when Attribute_Abort_Signal =>
2097 Check_Standard_Prefix;
2098 Rewrite (N, New_Reference_To (Stand.Abort_Signal, Loc));
2105 when Attribute_Access =>
2106 Analyze_Access_Attribute;
2112 when Attribute_Address =>
2115 -- Check for some junk cases, where we have to allow the address
2116 -- attribute but it does not make much sense, so at least for now
2117 -- just replace with Null_Address.
2119 -- We also do this if the prefix is a reference to the AST_Entry
2120 -- attribute. If expansion is active, the attribute will be
2121 -- replaced by a function call, and address will work fine and
2122 -- get the proper value, but if expansion is not active, then
2123 -- the check here allows proper semantic analysis of the reference.
2125 -- An Address attribute created by expansion is legal even when it
2126 -- applies to other entity-denoting expressions.
2128 if Is_Protected_Self_Reference (P) then
2130 -- Address attribute on a protected object self reference is legal
2134 elsif Is_Entity_Name (P) then
2136 Ent : constant Entity_Id := Entity (P);
2139 if Is_Subprogram (Ent) then
2140 Set_Address_Taken (Ent);
2141 Kill_Current_Values (Ent);
2143 -- An Address attribute is accepted when generated by the
2144 -- compiler for dispatching operation, and an error is
2145 -- issued once the subprogram is frozen (to avoid confusing
2146 -- errors about implicit uses of Address in the dispatch
2147 -- table initialization).
2149 if Has_Pragma_Inline_Always (Entity (P))
2150 and then Comes_From_Source (P)
2153 ("prefix of % attribute cannot be Inline_Always" &
2156 -- It is illegal to apply 'Address to an intrinsic
2157 -- subprogram. This is now formalized in AI05-0095.
2158 -- In an instance, an attempt to obtain 'Address of an
2159 -- intrinsic subprogram (e.g the renaming of a predefined
2160 -- operator that is an actual) raises Program_Error.
2162 elsif Convention (Ent) = Convention_Intrinsic then
2165 Make_Raise_Program_Error (Loc,
2166 Reason => PE_Address_Of_Intrinsic));
2170 ("cannot take Address of intrinsic subprogram", N);
2173 -- Issue an error if prefix denotes an eliminated subprogram
2176 Check_For_Eliminated_Subprogram (P, Ent);
2179 elsif Is_Object (Ent)
2180 or else Ekind (Ent) = E_Label
2182 Set_Address_Taken (Ent);
2184 -- If we have an address of an object, and the attribute
2185 -- comes from source, then set the object as potentially
2186 -- source modified. We do this because the resulting address
2187 -- can potentially be used to modify the variable and we
2188 -- might not detect this, leading to some junk warnings.
2190 Set_Never_Set_In_Source (Ent, False);
2192 elsif (Is_Concurrent_Type (Etype (Ent))
2193 and then Etype (Ent) = Base_Type (Ent))
2194 or else Ekind (Ent) = E_Package
2195 or else Is_Generic_Unit (Ent)
2198 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
2201 Error_Attr ("invalid prefix for % attribute", P);
2205 elsif Nkind (P) = N_Attribute_Reference
2206 and then Attribute_Name (P) = Name_AST_Entry
2209 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
2211 elsif Is_Object_Reference (P) then
2214 elsif Nkind (P) = N_Selected_Component
2215 and then Is_Subprogram (Entity (Selector_Name (P)))
2219 -- What exactly are we allowing here ??? and is this properly
2220 -- documented in the sinfo documentation for this node ???
2222 elsif not Comes_From_Source (N) then
2226 Error_Attr ("invalid prefix for % attribute", P);
2229 Set_Etype (N, RTE (RE_Address));
2235 when Attribute_Address_Size =>
2236 Standard_Attribute (System_Address_Size);
2242 when Attribute_Adjacent =>
2243 Check_Floating_Point_Type_2;
2244 Set_Etype (N, P_Base_Type);
2245 Resolve (E1, P_Base_Type);
2246 Resolve (E2, P_Base_Type);
2252 when Attribute_Aft =>
2253 Check_Fixed_Point_Type_0;
2254 Set_Etype (N, Universal_Integer);
2260 when Attribute_Alignment =>
2262 -- Don't we need more checking here, cf Size ???
2265 Check_Not_Incomplete_Type;
2267 Set_Etype (N, Universal_Integer);
2273 when Attribute_Asm_Input =>
2274 Check_Asm_Attribute;
2276 -- The back-end may need to take the address of E2
2278 if Is_Entity_Name (E2) then
2279 Set_Address_Taken (Entity (E2));
2282 Set_Etype (N, RTE (RE_Asm_Input_Operand));
2288 when Attribute_Asm_Output =>
2289 Check_Asm_Attribute;
2291 if Etype (E2) = Any_Type then
2294 elsif Aname = Name_Asm_Output then
2295 if not Is_Variable (E2) then
2297 ("second argument for Asm_Output is not variable", E2);
2301 Note_Possible_Modification (E2, Sure => True);
2303 -- The back-end may need to take the address of E2
2305 if Is_Entity_Name (E2) then
2306 Set_Address_Taken (Entity (E2));
2309 Set_Etype (N, RTE (RE_Asm_Output_Operand));
2315 when Attribute_AST_Entry => AST_Entry : declare
2321 -- Indicates if entry family index is present. Note the coding
2322 -- here handles the entry family case, but in fact it cannot be
2323 -- executed currently, because pragma AST_Entry does not permit
2324 -- the specification of an entry family.
2326 procedure Bad_AST_Entry;
2327 -- Signal a bad AST_Entry pragma
2329 function OK_Entry (E : Entity_Id) return Boolean;
2330 -- Checks that E is of an appropriate entity kind for an entry
2331 -- (i.e. E_Entry if Index is False, or E_Entry_Family if Index
2332 -- is set True for the entry family case). In the True case,
2333 -- makes sure that Is_AST_Entry is set on the entry.
2339 procedure Bad_AST_Entry is
2341 Error_Attr_P ("prefix for % attribute must be task entry");
2348 function OK_Entry (E : Entity_Id) return Boolean is
2353 Result := (Ekind (E) = E_Entry_Family);
2355 Result := (Ekind (E) = E_Entry);
2359 if not Is_AST_Entry (E) then
2360 Error_Msg_Name_2 := Aname;
2361 Error_Attr ("% attribute requires previous % pragma", P);
2368 -- Start of processing for AST_Entry
2374 -- Deal with entry family case
2376 if Nkind (P) = N_Indexed_Component then
2384 Ptyp := Etype (Pref);
2386 if Ptyp = Any_Type or else Error_Posted (Pref) then
2390 -- If the prefix is a selected component whose prefix is of an
2391 -- access type, then introduce an explicit dereference.
2392 -- ??? Could we reuse Check_Dereference here?
2394 if Nkind (Pref) = N_Selected_Component
2395 and then Is_Access_Type (Ptyp)
2398 Make_Explicit_Dereference (Sloc (Pref),
2399 Relocate_Node (Pref)));
2400 Analyze_And_Resolve (Pref, Designated_Type (Ptyp));
2403 -- Prefix can be of the form a.b, where a is a task object
2404 -- and b is one of the entries of the corresponding task type.
2406 if Nkind (Pref) = N_Selected_Component
2407 and then OK_Entry (Entity (Selector_Name (Pref)))
2408 and then Is_Object_Reference (Prefix (Pref))
2409 and then Is_Task_Type (Etype (Prefix (Pref)))
2413 -- Otherwise the prefix must be an entry of a containing task,
2414 -- or of a variable of the enclosing task type.
2417 if Nkind_In (Pref, N_Identifier, N_Expanded_Name) then
2418 Ent := Entity (Pref);
2420 if not OK_Entry (Ent)
2421 or else not In_Open_Scopes (Scope (Ent))
2431 Set_Etype (N, RTE (RE_AST_Handler));
2438 -- Note: when the base attribute appears in the context of a subtype
2439 -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by
2440 -- the following circuit.
2442 when Attribute_Base => Base : declare
2450 if Ada_Version >= Ada_95
2451 and then not Is_Scalar_Type (Typ)
2452 and then not Is_Generic_Type (Typ)
2454 Error_Attr_P ("prefix of Base attribute must be scalar type");
2456 elsif Sloc (Typ) = Standard_Location
2457 and then Base_Type (Typ) = Typ
2458 and then Warn_On_Redundant_Constructs
2460 Error_Msg_NE -- CODEFIX
2461 ("?redundant attribute, & is its own base type", N, Typ);
2464 if Nkind (Parent (N)) /= N_Attribute_Reference then
2465 Error_Msg_Name_1 := Aname;
2466 Check_Formal_Restriction
2467 ("attribute% is only allowed as prefix of another attribute", P);
2470 Set_Etype (N, Base_Type (Entity (P)));
2471 Set_Entity (N, Base_Type (Entity (P)));
2472 Rewrite (N, New_Reference_To (Entity (N), Loc));
2480 when Attribute_Bit => Bit :
2484 if not Is_Object_Reference (P) then
2485 Error_Attr_P ("prefix for % attribute must be object");
2487 -- What about the access object cases ???
2493 Set_Etype (N, Universal_Integer);
2500 when Attribute_Bit_Order => Bit_Order :
2505 if not Is_Record_Type (P_Type) then
2506 Error_Attr_P ("prefix of % attribute must be record type");
2509 if Bytes_Big_Endian xor Reverse_Bit_Order (P_Type) then
2511 New_Occurrence_Of (RTE (RE_High_Order_First), Loc));
2514 New_Occurrence_Of (RTE (RE_Low_Order_First), Loc));
2517 Set_Etype (N, RTE (RE_Bit_Order));
2520 -- Reset incorrect indication of staticness
2522 Set_Is_Static_Expression (N, False);
2529 -- Note: in generated code, we can have a Bit_Position attribute
2530 -- applied to a (naked) record component (i.e. the prefix is an
2531 -- identifier that references an E_Component or E_Discriminant
2532 -- entity directly, and this is interpreted as expected by Gigi.
2533 -- The following code will not tolerate such usage, but when the
2534 -- expander creates this special case, it marks it as analyzed
2535 -- immediately and sets an appropriate type.
2537 when Attribute_Bit_Position =>
2538 if Comes_From_Source (N) then
2542 Set_Etype (N, Universal_Integer);
2548 when Attribute_Body_Version =>
2551 Set_Etype (N, RTE (RE_Version_String));
2557 when Attribute_Callable =>
2559 Set_Etype (N, Standard_Boolean);
2566 when Attribute_Caller => Caller : declare
2573 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
2576 if not Is_Entry (Ent) then
2577 Error_Attr ("invalid entry name", N);
2581 Error_Attr ("invalid entry name", N);
2585 for J in reverse 0 .. Scope_Stack.Last loop
2586 S := Scope_Stack.Table (J).Entity;
2588 if S = Scope (Ent) then
2589 Error_Attr ("Caller must appear in matching accept or body", N);
2595 Set_Etype (N, RTE (RO_AT_Task_Id));
2602 when Attribute_Ceiling =>
2603 Check_Floating_Point_Type_1;
2604 Set_Etype (N, P_Base_Type);
2605 Resolve (E1, P_Base_Type);
2611 when Attribute_Class =>
2612 Check_Restriction (No_Dispatch, N);
2616 -- Applying Class to untagged incomplete type is obsolescent in Ada
2617 -- 2005. Note that we can't test Is_Tagged_Type here on P_Type, since
2618 -- this flag gets set by Find_Type in this situation.
2620 if Restriction_Check_Required (No_Obsolescent_Features)
2621 and then Ada_Version >= Ada_2005
2622 and then Ekind (P_Type) = E_Incomplete_Type
2625 DN : constant Node_Id := Declaration_Node (P_Type);
2627 if Nkind (DN) = N_Incomplete_Type_Declaration
2628 and then not Tagged_Present (DN)
2630 Check_Restriction (No_Obsolescent_Features, P);
2639 when Attribute_Code_Address =>
2642 if Nkind (P) = N_Attribute_Reference
2643 and then (Attribute_Name (P) = Name_Elab_Body
2645 Attribute_Name (P) = Name_Elab_Spec)
2649 elsif not Is_Entity_Name (P)
2650 or else (Ekind (Entity (P)) /= E_Function
2652 Ekind (Entity (P)) /= E_Procedure)
2654 Error_Attr ("invalid prefix for % attribute", P);
2655 Set_Address_Taken (Entity (P));
2657 -- Issue an error if the prefix denotes an eliminated subprogram
2660 Check_For_Eliminated_Subprogram (P, Entity (P));
2663 Set_Etype (N, RTE (RE_Address));
2665 ----------------------
2666 -- Compiler_Version --
2667 ----------------------
2669 when Attribute_Compiler_Version =>
2671 Check_Standard_Prefix;
2672 Rewrite (N, Make_String_Literal (Loc, "GNAT " & Gnat_Version_String));
2673 Analyze_And_Resolve (N, Standard_String);
2675 --------------------
2676 -- Component_Size --
2677 --------------------
2679 when Attribute_Component_Size =>
2681 Set_Etype (N, Universal_Integer);
2683 -- Note: unlike other array attributes, unconstrained arrays are OK
2685 if Is_Array_Type (P_Type) and then not Is_Constrained (P_Type) then
2695 when Attribute_Compose =>
2696 Check_Floating_Point_Type_2;
2697 Set_Etype (N, P_Base_Type);
2698 Resolve (E1, P_Base_Type);
2699 Resolve (E2, Any_Integer);
2705 when Attribute_Constrained =>
2707 Set_Etype (N, Standard_Boolean);
2709 -- Case from RM J.4(2) of constrained applied to private type
2711 if Is_Entity_Name (P) and then Is_Type (Entity (P)) then
2712 Check_Restriction (No_Obsolescent_Features, P);
2714 if Warn_On_Obsolescent_Feature then
2716 ("constrained for private type is an " &
2717 "obsolescent feature (RM J.4)?", N);
2720 -- If we are within an instance, the attribute must be legal
2721 -- because it was valid in the generic unit. Ditto if this is
2722 -- an inlining of a function declared in an instance.
2725 or else In_Inlined_Body
2729 -- For sure OK if we have a real private type itself, but must
2730 -- be completed, cannot apply Constrained to incomplete type.
2732 elsif Is_Private_Type (Entity (P)) then
2734 -- Note: this is one of the Annex J features that does not
2735 -- generate a warning from -gnatwj, since in fact it seems
2736 -- very useful, and is used in the GNAT runtime.
2738 Check_Not_Incomplete_Type;
2742 -- Normal (non-obsolescent case) of application to object of
2743 -- a discriminated type.
2746 Check_Object_Reference (P);
2748 -- If N does not come from source, then we allow the
2749 -- the attribute prefix to be of a private type whose
2750 -- full type has discriminants. This occurs in cases
2751 -- involving expanded calls to stream attributes.
2753 if not Comes_From_Source (N) then
2754 P_Type := Underlying_Type (P_Type);
2757 -- Must have discriminants or be an access type designating
2758 -- a type with discriminants. If it is a classwide type is ???
2759 -- has unknown discriminants.
2761 if Has_Discriminants (P_Type)
2762 or else Has_Unknown_Discriminants (P_Type)
2764 (Is_Access_Type (P_Type)
2765 and then Has_Discriminants (Designated_Type (P_Type)))
2769 -- Also allow an object of a generic type if extensions allowed
2770 -- and allow this for any type at all.
2772 elsif (Is_Generic_Type (P_Type)
2773 or else Is_Generic_Actual_Type (P_Type))
2774 and then Extensions_Allowed
2780 -- Fall through if bad prefix
2783 ("prefix of % attribute must be object of discriminated type");
2789 when Attribute_Copy_Sign =>
2790 Check_Floating_Point_Type_2;
2791 Set_Etype (N, P_Base_Type);
2792 Resolve (E1, P_Base_Type);
2793 Resolve (E2, P_Base_Type);
2799 when Attribute_Count => Count :
2808 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
2811 if Ekind (Ent) /= E_Entry then
2812 Error_Attr ("invalid entry name", N);
2815 elsif Nkind (P) = N_Indexed_Component then
2816 if not Is_Entity_Name (Prefix (P))
2817 or else No (Entity (Prefix (P)))
2818 or else Ekind (Entity (Prefix (P))) /= E_Entry_Family
2820 if Nkind (Prefix (P)) = N_Selected_Component
2821 and then Present (Entity (Selector_Name (Prefix (P))))
2822 and then Ekind (Entity (Selector_Name (Prefix (P)))) =
2826 ("attribute % must apply to entry of current task", P);
2829 Error_Attr ("invalid entry family name", P);
2834 Ent := Entity (Prefix (P));
2837 elsif Nkind (P) = N_Selected_Component
2838 and then Present (Entity (Selector_Name (P)))
2839 and then Ekind (Entity (Selector_Name (P))) = E_Entry
2842 ("attribute % must apply to entry of current task", P);
2845 Error_Attr ("invalid entry name", N);
2849 for J in reverse 0 .. Scope_Stack.Last loop
2850 S := Scope_Stack.Table (J).Entity;
2852 if S = Scope (Ent) then
2853 if Nkind (P) = N_Expanded_Name then
2854 Tsk := Entity (Prefix (P));
2856 -- The prefix denotes either the task type, or else a
2857 -- single task whose task type is being analyzed.
2862 or else (not Is_Type (Tsk)
2863 and then Etype (Tsk) = S
2864 and then not (Comes_From_Source (S)))
2869 ("Attribute % must apply to entry of current task", N);
2875 elsif Ekind (Scope (Ent)) in Task_Kind
2877 not Ekind_In (S, E_Loop, E_Block, E_Entry, E_Entry_Family)
2879 Error_Attr ("Attribute % cannot appear in inner unit", N);
2881 elsif Ekind (Scope (Ent)) = E_Protected_Type
2882 and then not Has_Completion (Scope (Ent))
2884 Error_Attr ("attribute % can only be used inside body", N);
2888 if Is_Overloaded (P) then
2890 Index : Interp_Index;
2894 Get_First_Interp (P, Index, It);
2896 while Present (It.Nam) loop
2897 if It.Nam = Ent then
2900 -- Ada 2005 (AI-345): Do not consider primitive entry
2901 -- wrappers generated for task or protected types.
2903 elsif Ada_Version >= Ada_2005
2904 and then not Comes_From_Source (It.Nam)
2909 Error_Attr ("ambiguous entry name", N);
2912 Get_Next_Interp (Index, It);
2917 Set_Etype (N, Universal_Integer);
2920 -----------------------
2921 -- Default_Bit_Order --
2922 -----------------------
2924 when Attribute_Default_Bit_Order => Default_Bit_Order :
2926 Check_Standard_Prefix;
2928 if Bytes_Big_Endian then
2930 Make_Integer_Literal (Loc, False_Value));
2933 Make_Integer_Literal (Loc, True_Value));
2936 Set_Etype (N, Universal_Integer);
2937 Set_Is_Static_Expression (N);
2938 end Default_Bit_Order;
2944 when Attribute_Definite =>
2945 Legal_Formal_Attribute;
2951 when Attribute_Delta =>
2952 Check_Fixed_Point_Type_0;
2953 Set_Etype (N, Universal_Real);
2959 when Attribute_Denorm =>
2960 Check_Floating_Point_Type_0;
2961 Set_Etype (N, Standard_Boolean);
2967 when Attribute_Digits =>
2971 if not Is_Floating_Point_Type (P_Type)
2972 and then not Is_Decimal_Fixed_Point_Type (P_Type)
2975 ("prefix of % attribute must be float or decimal type");
2978 Set_Etype (N, Universal_Integer);
2984 -- Also handles processing for Elab_Spec
2986 when Attribute_Elab_Body | Attribute_Elab_Spec =>
2988 Check_Unit_Name (P);
2989 Set_Etype (N, Standard_Void_Type);
2991 -- We have to manually call the expander in this case to get
2992 -- the necessary expansion (normally attributes that return
2993 -- entities are not expanded).
3001 -- Shares processing with Elab_Body
3007 when Attribute_Elaborated =>
3010 Set_Etype (N, Standard_Boolean);
3016 when Attribute_Emax =>
3017 Check_Floating_Point_Type_0;
3018 Set_Etype (N, Universal_Integer);
3024 when Attribute_Enabled =>
3025 Check_Either_E0_Or_E1;
3027 if Present (E1) then
3028 if not Is_Entity_Name (E1) or else No (Entity (E1)) then
3029 Error_Msg_N ("entity name expected for Enabled attribute", E1);
3034 if Nkind (P) /= N_Identifier then
3035 Error_Msg_N ("identifier expected (check name)", P);
3036 elsif Get_Check_Id (Chars (P)) = No_Check_Id then
3037 Error_Msg_N ("& is not a recognized check name", P);
3040 Set_Etype (N, Standard_Boolean);
3046 when Attribute_Enum_Rep => Enum_Rep : declare
3048 if Present (E1) then
3050 Check_Discrete_Type;
3051 Resolve (E1, P_Base_Type);
3054 if not Is_Entity_Name (P)
3055 or else (not Is_Object (Entity (P))
3057 Ekind (Entity (P)) /= E_Enumeration_Literal)
3060 ("prefix of % attribute must be " &
3061 "discrete type/object or enum literal");
3065 Set_Etype (N, Universal_Integer);
3072 when Attribute_Enum_Val => Enum_Val : begin
3076 if not Is_Enumeration_Type (P_Type) then
3077 Error_Attr_P ("prefix of % attribute must be enumeration type");
3080 -- If the enumeration type has a standard representation, the effect
3081 -- is the same as 'Val, so rewrite the attribute as a 'Val.
3083 if not Has_Non_Standard_Rep (P_Base_Type) then
3085 Make_Attribute_Reference (Loc,
3086 Prefix => Relocate_Node (Prefix (N)),
3087 Attribute_Name => Name_Val,
3088 Expressions => New_List (Relocate_Node (E1))));
3089 Analyze_And_Resolve (N, P_Base_Type);
3091 -- Non-standard representation case (enumeration with holes)
3095 Resolve (E1, Any_Integer);
3096 Set_Etype (N, P_Base_Type);
3104 when Attribute_Epsilon =>
3105 Check_Floating_Point_Type_0;
3106 Set_Etype (N, Universal_Real);
3112 when Attribute_Exponent =>
3113 Check_Floating_Point_Type_1;
3114 Set_Etype (N, Universal_Integer);
3115 Resolve (E1, P_Base_Type);
3121 when Attribute_External_Tag =>
3125 Set_Etype (N, Standard_String);
3127 if not Is_Tagged_Type (P_Type) then
3128 Error_Attr_P ("prefix of % attribute must be tagged");
3135 when Attribute_Fast_Math =>
3136 Check_Standard_Prefix;
3138 if Opt.Fast_Math then
3139 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
3141 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
3148 when Attribute_First =>
3149 Check_Array_Or_Scalar_Type;
3150 Bad_Attribute_For_Predicate;
3156 when Attribute_First_Bit =>
3158 Set_Etype (N, Universal_Integer);
3164 when Attribute_Fixed_Value =>
3166 Check_Fixed_Point_Type;
3167 Resolve (E1, Any_Integer);
3168 Set_Etype (N, P_Base_Type);
3174 when Attribute_Floor =>
3175 Check_Floating_Point_Type_1;
3176 Set_Etype (N, P_Base_Type);
3177 Resolve (E1, P_Base_Type);
3183 when Attribute_Fore =>
3184 Check_Fixed_Point_Type_0;
3185 Set_Etype (N, Universal_Integer);
3191 when Attribute_Fraction =>
3192 Check_Floating_Point_Type_1;
3193 Set_Etype (N, P_Base_Type);
3194 Resolve (E1, P_Base_Type);
3200 when Attribute_From_Any =>
3202 Check_PolyORB_Attribute;
3203 Set_Etype (N, P_Base_Type);
3205 -----------------------
3206 -- Has_Access_Values --
3207 -----------------------
3209 when Attribute_Has_Access_Values =>
3212 Set_Etype (N, Standard_Boolean);
3214 -----------------------
3215 -- Has_Tagged_Values --
3216 -----------------------
3218 when Attribute_Has_Tagged_Values =>
3221 Set_Etype (N, Standard_Boolean);
3223 -----------------------
3224 -- Has_Discriminants --
3225 -----------------------
3227 when Attribute_Has_Discriminants =>
3228 Legal_Formal_Attribute;
3234 when Attribute_Identity =>
3238 if Etype (P) = Standard_Exception_Type then
3239 Set_Etype (N, RTE (RE_Exception_Id));
3241 -- Ada 2005 (AI-345): Attribute 'Identity may be applied to
3242 -- task interface class-wide types.
3244 elsif Is_Task_Type (Etype (P))
3245 or else (Is_Access_Type (Etype (P))
3246 and then Is_Task_Type (Designated_Type (Etype (P))))
3247 or else (Ada_Version >= Ada_2005
3248 and then Ekind (Etype (P)) = E_Class_Wide_Type
3249 and then Is_Interface (Etype (P))
3250 and then Is_Task_Interface (Etype (P)))
3253 Set_Etype (N, RTE (RO_AT_Task_Id));
3256 if Ada_Version >= Ada_2005 then
3258 ("prefix of % attribute must be an exception, a " &
3259 "task or a task interface class-wide object");
3262 ("prefix of % attribute must be a task or an exception");
3270 when Attribute_Image => Image :
3272 Check_Formal_Restriction_On_Attribute;
3274 Set_Etype (N, Standard_String);
3276 if Is_Real_Type (P_Type) then
3277 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3278 Error_Msg_Name_1 := Aname;
3280 ("(Ada 83) % attribute not allowed for real types", N);
3284 if Is_Enumeration_Type (P_Type) then
3285 Check_Restriction (No_Enumeration_Maps, N);
3289 Resolve (E1, P_Base_Type);
3291 Validate_Non_Static_Attribute_Function_Call;
3298 when Attribute_Img => Img :
3301 Set_Etype (N, Standard_String);
3303 if not Is_Scalar_Type (P_Type)
3304 or else (Is_Entity_Name (P) and then Is_Type (Entity (P)))
3307 ("prefix of % attribute must be scalar object name");
3317 when Attribute_Input =>
3319 Check_Stream_Attribute (TSS_Stream_Input);
3320 Set_Etype (N, P_Base_Type);
3326 when Attribute_Integer_Value =>
3329 Resolve (E1, Any_Fixed);
3331 -- Signal an error if argument type is not a specific fixed-point
3332 -- subtype. An error has been signalled already if the argument
3333 -- was not of a fixed-point type.
3335 if Etype (E1) = Any_Fixed and then not Error_Posted (E1) then
3336 Error_Attr ("argument of % must be of a fixed-point type", E1);
3339 Set_Etype (N, P_Base_Type);
3345 when Attribute_Invalid_Value =>
3348 Set_Etype (N, P_Base_Type);
3349 Invalid_Value_Used := True;
3355 when Attribute_Large =>
3358 Set_Etype (N, Universal_Real);
3364 when Attribute_Last =>
3365 Check_Array_Or_Scalar_Type;
3366 Bad_Attribute_For_Predicate;
3372 when Attribute_Last_Bit =>
3374 Set_Etype (N, Universal_Integer);
3380 when Attribute_Leading_Part =>
3381 Check_Floating_Point_Type_2;
3382 Set_Etype (N, P_Base_Type);
3383 Resolve (E1, P_Base_Type);
3384 Resolve (E2, Any_Integer);
3390 when Attribute_Length =>
3392 Set_Etype (N, Universal_Integer);
3398 when Attribute_Machine =>
3399 Check_Floating_Point_Type_1;
3400 Set_Etype (N, P_Base_Type);
3401 Resolve (E1, P_Base_Type);
3407 when Attribute_Machine_Emax =>
3408 Check_Floating_Point_Type_0;
3409 Set_Etype (N, Universal_Integer);
3415 when Attribute_Machine_Emin =>
3416 Check_Floating_Point_Type_0;
3417 Set_Etype (N, Universal_Integer);
3419 ----------------------
3420 -- Machine_Mantissa --
3421 ----------------------
3423 when Attribute_Machine_Mantissa =>
3424 Check_Floating_Point_Type_0;
3425 Set_Etype (N, Universal_Integer);
3427 -----------------------
3428 -- Machine_Overflows --
3429 -----------------------
3431 when Attribute_Machine_Overflows =>
3434 Set_Etype (N, Standard_Boolean);
3440 when Attribute_Machine_Radix =>
3443 Set_Etype (N, Universal_Integer);
3445 ----------------------
3446 -- Machine_Rounding --
3447 ----------------------
3449 when Attribute_Machine_Rounding =>
3450 Check_Floating_Point_Type_1;
3451 Set_Etype (N, P_Base_Type);
3452 Resolve (E1, P_Base_Type);
3454 --------------------
3455 -- Machine_Rounds --
3456 --------------------
3458 when Attribute_Machine_Rounds =>
3461 Set_Etype (N, Standard_Boolean);
3467 when Attribute_Machine_Size =>
3470 Check_Not_Incomplete_Type;
3471 Set_Etype (N, Universal_Integer);
3477 when Attribute_Mantissa =>
3480 Set_Etype (N, Universal_Integer);
3486 when Attribute_Max =>
3489 Resolve (E1, P_Base_Type);
3490 Resolve (E2, P_Base_Type);
3491 Set_Etype (N, P_Base_Type);
3493 ----------------------------------
3494 -- Max_Alignment_For_Allocation --
3495 -- Max_Size_In_Storage_Elements --
3496 ----------------------------------
3498 when Attribute_Max_Alignment_For_Allocation |
3499 Attribute_Max_Size_In_Storage_Elements =>
3502 Check_Not_Incomplete_Type;
3503 Set_Etype (N, Universal_Integer);
3505 -----------------------
3506 -- Maximum_Alignment --
3507 -----------------------
3509 when Attribute_Maximum_Alignment =>
3510 Standard_Attribute (Ttypes.Maximum_Alignment);
3512 --------------------
3513 -- Mechanism_Code --
3514 --------------------
3516 when Attribute_Mechanism_Code =>
3517 if not Is_Entity_Name (P)
3518 or else not Is_Subprogram (Entity (P))
3520 Error_Attr_P ("prefix of % attribute must be subprogram");
3523 Check_Either_E0_Or_E1;
3525 if Present (E1) then
3526 Resolve (E1, Any_Integer);
3527 Set_Etype (E1, Standard_Integer);
3529 if not Is_Static_Expression (E1) then
3530 Flag_Non_Static_Expr
3531 ("expression for parameter number must be static!", E1);
3534 elsif UI_To_Int (Intval (E1)) > Number_Formals (Entity (P))
3535 or else UI_To_Int (Intval (E1)) < 0
3537 Error_Attr ("invalid parameter number for % attribute", E1);
3541 Set_Etype (N, Universal_Integer);
3547 when Attribute_Min =>
3550 Resolve (E1, P_Base_Type);
3551 Resolve (E2, P_Base_Type);
3552 Set_Etype (N, P_Base_Type);
3558 when Attribute_Mod =>
3560 -- Note: this attribute is only allowed in Ada 2005 mode, but
3561 -- we do not need to test that here, since Mod is only recognized
3562 -- as an attribute name in Ada 2005 mode during the parse.
3565 Check_Modular_Integer_Type;
3566 Resolve (E1, Any_Integer);
3567 Set_Etype (N, P_Base_Type);
3573 when Attribute_Model =>
3574 Check_Floating_Point_Type_1;
3575 Set_Etype (N, P_Base_Type);
3576 Resolve (E1, P_Base_Type);
3582 when Attribute_Model_Emin =>
3583 Check_Floating_Point_Type_0;
3584 Set_Etype (N, Universal_Integer);
3590 when Attribute_Model_Epsilon =>
3591 Check_Floating_Point_Type_0;
3592 Set_Etype (N, Universal_Real);
3594 --------------------
3595 -- Model_Mantissa --
3596 --------------------
3598 when Attribute_Model_Mantissa =>
3599 Check_Floating_Point_Type_0;
3600 Set_Etype (N, Universal_Integer);
3606 when Attribute_Model_Small =>
3607 Check_Floating_Point_Type_0;
3608 Set_Etype (N, Universal_Real);
3614 when Attribute_Modulus =>
3616 Check_Modular_Integer_Type;
3617 Set_Etype (N, Universal_Integer);
3619 --------------------
3620 -- Null_Parameter --
3621 --------------------
3623 when Attribute_Null_Parameter => Null_Parameter : declare
3624 Parnt : constant Node_Id := Parent (N);
3625 GParnt : constant Node_Id := Parent (Parnt);
3627 procedure Bad_Null_Parameter (Msg : String);
3628 -- Used if bad Null parameter attribute node is found. Issues
3629 -- given error message, and also sets the type to Any_Type to
3630 -- avoid blowups later on from dealing with a junk node.
3632 procedure Must_Be_Imported (Proc_Ent : Entity_Id);
3633 -- Called to check that Proc_Ent is imported subprogram
3635 ------------------------
3636 -- Bad_Null_Parameter --
3637 ------------------------
3639 procedure Bad_Null_Parameter (Msg : String) is
3641 Error_Msg_N (Msg, N);
3642 Set_Etype (N, Any_Type);
3643 end Bad_Null_Parameter;
3645 ----------------------
3646 -- Must_Be_Imported --
3647 ----------------------
3649 procedure Must_Be_Imported (Proc_Ent : Entity_Id) is
3650 Pent : constant Entity_Id := Ultimate_Alias (Proc_Ent);
3653 -- Ignore check if procedure not frozen yet (we will get
3654 -- another chance when the default parameter is reanalyzed)
3656 if not Is_Frozen (Pent) then
3659 elsif not Is_Imported (Pent) then
3661 ("Null_Parameter can only be used with imported subprogram");
3666 end Must_Be_Imported;
3668 -- Start of processing for Null_Parameter
3673 Set_Etype (N, P_Type);
3675 -- Case of attribute used as default expression
3677 if Nkind (Parnt) = N_Parameter_Specification then
3678 Must_Be_Imported (Defining_Entity (GParnt));
3680 -- Case of attribute used as actual for subprogram (positional)
3682 elsif Nkind_In (Parnt, N_Procedure_Call_Statement,
3684 and then Is_Entity_Name (Name (Parnt))
3686 Must_Be_Imported (Entity (Name (Parnt)));
3688 -- Case of attribute used as actual for subprogram (named)
3690 elsif Nkind (Parnt) = N_Parameter_Association
3691 and then Nkind_In (GParnt, N_Procedure_Call_Statement,
3693 and then Is_Entity_Name (Name (GParnt))
3695 Must_Be_Imported (Entity (Name (GParnt)));
3697 -- Not an allowed case
3701 ("Null_Parameter must be actual or default parameter");
3709 when Attribute_Object_Size =>
3712 Check_Not_Incomplete_Type;
3713 Set_Etype (N, Universal_Integer);
3719 when Attribute_Old =>
3721 -- The attribute reference is a primary. If expressions follow, the
3722 -- attribute reference is an indexable object, so rewrite the node
3725 if Present (E1) then
3727 Make_Indexed_Component (Loc,
3729 Make_Attribute_Reference (Loc,
3730 Prefix => Relocate_Node (Prefix (N)),
3731 Attribute_Name => Name_Old),
3732 Expressions => Expressions (N)));
3739 Set_Etype (N, P_Type);
3741 if No (Current_Subprogram) then
3742 Error_Attr ("attribute % can only appear within subprogram", N);
3745 if Is_Limited_Type (P_Type) then
3746 Error_Attr ("attribute % cannot apply to limited objects", P);
3749 if Is_Entity_Name (P)
3750 and then Is_Constant_Object (Entity (P))
3753 ("?attribute Old applied to constant has no effect", P);
3756 -- Check that the expression does not refer to local entities
3758 Check_Local : declare
3759 Subp : Entity_Id := Current_Subprogram;
3761 function Process (N : Node_Id) return Traverse_Result;
3762 -- Check that N does not contain references to local variables or
3763 -- other local entities of Subp.
3769 function Process (N : Node_Id) return Traverse_Result is
3771 if Is_Entity_Name (N)
3772 and then Present (Entity (N))
3773 and then not Is_Formal (Entity (N))
3774 and then Enclosing_Subprogram (Entity (N)) = Subp
3776 Error_Msg_Node_1 := Entity (N);
3778 ("attribute % cannot refer to local variable&", N);
3784 procedure Check_No_Local is new Traverse_Proc;
3786 -- Start of processing for Check_Local
3791 if In_Parameter_Specification (P) then
3793 -- We have additional restrictions on using 'Old in parameter
3796 if Present (Enclosing_Subprogram (Current_Subprogram)) then
3798 -- Check that there is no reference to the enclosing
3799 -- subprogram local variables. Otherwise, we might end up
3800 -- being called from the enclosing subprogram and thus using
3801 -- 'Old on a local variable which is not defined at entry
3804 Subp := Enclosing_Subprogram (Current_Subprogram);
3808 -- We must prevent default expression of library-level
3809 -- subprogram from using 'Old, as the subprogram may be
3810 -- used in elaboration code for which there is no enclosing
3814 ("attribute % can only appear within subprogram", N);
3823 when Attribute_Output =>
3825 Check_Stream_Attribute (TSS_Stream_Output);
3826 Set_Etype (N, Standard_Void_Type);
3827 Resolve (N, Standard_Void_Type);
3833 when Attribute_Partition_ID => Partition_Id :
3837 if P_Type /= Any_Type then
3838 if not Is_Library_Level_Entity (Entity (P)) then
3840 ("prefix of % attribute must be library-level entity");
3842 -- The defining entity of prefix should not be declared inside a
3843 -- Pure unit. RM E.1(8). Is_Pure was set during declaration.
3845 elsif Is_Entity_Name (P)
3846 and then Is_Pure (Entity (P))
3848 Error_Attr_P ("prefix of% attribute must not be declared pure");
3852 Set_Etype (N, Universal_Integer);
3855 -------------------------
3856 -- Passed_By_Reference --
3857 -------------------------
3859 when Attribute_Passed_By_Reference =>
3862 Set_Etype (N, Standard_Boolean);
3868 when Attribute_Pool_Address =>
3870 Set_Etype (N, RTE (RE_Address));
3876 when Attribute_Pos =>
3877 Check_Discrete_Type;
3880 if Is_Boolean_Type (P_Type) then
3881 Error_Msg_Name_1 := Aname;
3882 Error_Msg_Name_2 := Chars (P_Type);
3883 Check_Formal_Restriction
3884 ("attribute% is not allowed for type%", P);
3887 Resolve (E1, P_Base_Type);
3888 Set_Etype (N, Universal_Integer);
3894 when Attribute_Position =>
3896 Set_Etype (N, Universal_Integer);
3902 when Attribute_Pred =>
3906 if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then
3907 Error_Msg_Name_1 := Aname;
3908 Error_Msg_Name_2 := Chars (P_Type);
3909 Check_Formal_Restriction
3910 ("attribute% is not allowed for type%", P);
3913 Resolve (E1, P_Base_Type);
3914 Set_Etype (N, P_Base_Type);
3916 -- Nothing to do for real type case
3918 if Is_Real_Type (P_Type) then
3921 -- If not modular type, test for overflow check required
3924 if not Is_Modular_Integer_Type (P_Type)
3925 and then not Range_Checks_Suppressed (P_Base_Type)
3927 Enable_Range_Check (E1);
3935 -- Ada 2005 (AI-327): Dynamic ceiling priorities
3937 when Attribute_Priority =>
3938 if Ada_Version < Ada_2005 then
3939 Error_Attr ("% attribute is allowed only in Ada 2005 mode", P);
3944 -- The prefix must be a protected object (AARM D.5.2 (2/2))
3948 if Is_Protected_Type (Etype (P))
3949 or else (Is_Access_Type (Etype (P))
3950 and then Is_Protected_Type (Designated_Type (Etype (P))))
3952 Resolve (P, Etype (P));
3954 Error_Attr_P ("prefix of % attribute must be a protected object");
3957 Set_Etype (N, Standard_Integer);
3959 -- Must be called from within a protected procedure or entry of the
3960 -- protected object.
3967 while S /= Etype (P)
3968 and then S /= Standard_Standard
3973 if S = Standard_Standard then
3974 Error_Attr ("the attribute % is only allowed inside protected "
3979 Validate_Non_Static_Attribute_Function_Call;
3985 when Attribute_Range =>
3986 Check_Array_Or_Scalar_Type;
3987 Bad_Attribute_For_Predicate;
3989 if Ada_Version = Ada_83
3990 and then Is_Scalar_Type (P_Type)
3991 and then Comes_From_Source (N)
3994 ("(Ada 83) % attribute not allowed for scalar type", P);
4001 when Attribute_Result => Result : declare
4003 -- The enclosing scope, excluding loops for quantified expressions
4006 -- During analysis, CS is the postcondition subprogram and PS the
4007 -- source subprogram to which the postcondition applies. During
4008 -- pre-analysis, CS is the scope of the subprogram declaration.
4011 -- Find enclosing scopes, excluding loops
4013 CS := Current_Scope;
4014 while Ekind (CS) = E_Loop loop
4020 -- If the enclosing subprogram is always inlined, the enclosing
4021 -- postcondition will not be propagated to the expanded call.
4023 if not In_Spec_Expression
4024 and then Has_Pragma_Inline_Always (PS)
4025 and then Warn_On_Redundant_Constructs
4028 ("postconditions on inlined functions not enforced?", N);
4031 -- If we are in the scope of a function and in Spec_Expression mode,
4032 -- this is likely the prescan of the postcondition pragma, and we
4033 -- just set the proper type. If there is an error it will be caught
4034 -- when the real Analyze call is done.
4036 if Ekind (CS) = E_Function
4037 and then In_Spec_Expression
4041 if Chars (CS) /= Chars (P) then
4042 Error_Msg_Name_1 := Name_Result;
4045 ("incorrect prefix for % attribute, expected &", P, CS);
4049 Set_Etype (N, Etype (CS));
4051 -- If several functions with that name are visible,
4052 -- the intended one is the current scope.
4054 if Is_Overloaded (P) then
4056 Set_Is_Overloaded (P, False);
4059 -- Body case, where we must be inside a generated _Postcondition
4060 -- procedure, and the prefix must be on the scope stack, or else
4061 -- the attribute use is definitely misplaced. The condition itself
4062 -- may have generated transient scopes, and is not necessarily the
4066 while Present (CS) and then CS /= Standard_Standard loop
4067 if Chars (CS) = Name_uPostconditions then
4076 if Chars (CS) = Name_uPostconditions
4077 and then Ekind (PS) = E_Function
4081 if Nkind_In (P, N_Identifier, N_Operator_Symbol)
4082 and then Chars (P) = Chars (PS)
4086 -- Within an instance, the prefix designates the local renaming
4087 -- of the original generic.
4089 elsif Is_Entity_Name (P)
4090 and then Ekind (Entity (P)) = E_Function
4091 and then Present (Alias (Entity (P)))
4092 and then Chars (Alias (Entity (P))) = Chars (PS)
4098 ("incorrect prefix for % attribute, expected &", P, PS);
4102 Rewrite (N, Make_Identifier (Sloc (N), Name_uResult));
4103 Analyze_And_Resolve (N, Etype (PS));
4107 ("% attribute can only appear" &
4108 " in function Postcondition pragma", P);
4117 when Attribute_Range_Length =>
4119 Check_Discrete_Type;
4120 Set_Etype (N, Universal_Integer);
4126 when Attribute_Read =>
4128 Check_Stream_Attribute (TSS_Stream_Read);
4129 Set_Etype (N, Standard_Void_Type);
4130 Resolve (N, Standard_Void_Type);
4131 Note_Possible_Modification (E2, Sure => True);
4137 when Attribute_Ref =>
4141 if Nkind (P) /= N_Expanded_Name
4142 or else not Is_RTE (P_Type, RE_Address)
4144 Error_Attr_P ("prefix of % attribute must be System.Address");
4147 Analyze_And_Resolve (E1, Any_Integer);
4148 Set_Etype (N, RTE (RE_Address));
4154 when Attribute_Remainder =>
4155 Check_Floating_Point_Type_2;
4156 Set_Etype (N, P_Base_Type);
4157 Resolve (E1, P_Base_Type);
4158 Resolve (E2, P_Base_Type);
4164 when Attribute_Round =>
4166 Check_Decimal_Fixed_Point_Type;
4167 Set_Etype (N, P_Base_Type);
4169 -- Because the context is universal_real (3.5.10(12)) it is a legal
4170 -- context for a universal fixed expression. This is the only
4171 -- attribute whose functional description involves U_R.
4173 if Etype (E1) = Universal_Fixed then
4175 Conv : constant Node_Id := Make_Type_Conversion (Loc,
4176 Subtype_Mark => New_Occurrence_Of (Universal_Real, Loc),
4177 Expression => Relocate_Node (E1));
4185 Resolve (E1, Any_Real);
4191 when Attribute_Rounding =>
4192 Check_Floating_Point_Type_1;
4193 Set_Etype (N, P_Base_Type);
4194 Resolve (E1, P_Base_Type);
4200 when Attribute_Safe_Emax =>
4201 Check_Floating_Point_Type_0;
4202 Set_Etype (N, Universal_Integer);
4208 when Attribute_Safe_First =>
4209 Check_Floating_Point_Type_0;
4210 Set_Etype (N, Universal_Real);
4216 when Attribute_Safe_Large =>
4219 Set_Etype (N, Universal_Real);
4225 when Attribute_Safe_Last =>
4226 Check_Floating_Point_Type_0;
4227 Set_Etype (N, Universal_Real);
4233 when Attribute_Safe_Small =>
4236 Set_Etype (N, Universal_Real);
4242 when Attribute_Scale =>
4244 Check_Decimal_Fixed_Point_Type;
4245 Set_Etype (N, Universal_Integer);
4251 when Attribute_Scaling =>
4252 Check_Floating_Point_Type_2;
4253 Set_Etype (N, P_Base_Type);
4254 Resolve (E1, P_Base_Type);
4260 when Attribute_Signed_Zeros =>
4261 Check_Floating_Point_Type_0;
4262 Set_Etype (N, Standard_Boolean);
4268 when Attribute_Size | Attribute_VADS_Size => Size :
4272 -- If prefix is parameterless function call, rewrite and resolve
4275 if Is_Entity_Name (P)
4276 and then Ekind (Entity (P)) = E_Function
4280 -- Similar processing for a protected function call
4282 elsif Nkind (P) = N_Selected_Component
4283 and then Ekind (Entity (Selector_Name (P))) = E_Function
4288 if Is_Object_Reference (P) then
4289 Check_Object_Reference (P);
4291 elsif Is_Entity_Name (P)
4292 and then (Is_Type (Entity (P))
4293 or else Ekind (Entity (P)) = E_Enumeration_Literal)
4297 elsif Nkind (P) = N_Type_Conversion
4298 and then not Comes_From_Source (P)
4303 Error_Attr_P ("invalid prefix for % attribute");
4306 Check_Not_Incomplete_Type;
4308 Set_Etype (N, Universal_Integer);
4315 when Attribute_Small =>
4318 Set_Etype (N, Universal_Real);
4324 when Attribute_Storage_Pool => Storage_Pool :
4328 if Is_Access_Type (P_Type) then
4329 if Ekind (P_Type) = E_Access_Subprogram_Type then
4331 ("cannot use % attribute for access-to-subprogram type");
4334 -- Set appropriate entity
4336 if Present (Associated_Storage_Pool (Root_Type (P_Type))) then
4337 Set_Entity (N, Associated_Storage_Pool (Root_Type (P_Type)));
4339 Set_Entity (N, RTE (RE_Global_Pool_Object));
4342 Set_Etype (N, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
4344 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4345 -- Storage_Pool since this attribute is not defined for such
4346 -- types (RM E.2.3(22)).
4348 Validate_Remote_Access_To_Class_Wide_Type (N);
4351 Error_Attr_P ("prefix of % attribute must be access type");
4359 when Attribute_Storage_Size => Storage_Size :
4363 if Is_Task_Type (P_Type) then
4364 Set_Etype (N, Universal_Integer);
4366 -- Use with tasks is an obsolescent feature
4368 Check_Restriction (No_Obsolescent_Features, P);
4370 elsif Is_Access_Type (P_Type) then
4371 if Ekind (P_Type) = E_Access_Subprogram_Type then
4373 ("cannot use % attribute for access-to-subprogram type");
4376 if Is_Entity_Name (P)
4377 and then Is_Type (Entity (P))
4380 Set_Etype (N, Universal_Integer);
4382 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4383 -- Storage_Size since this attribute is not defined for
4384 -- such types (RM E.2.3(22)).
4386 Validate_Remote_Access_To_Class_Wide_Type (N);
4388 -- The prefix is allowed to be an implicit dereference
4389 -- of an access value designating a task.
4393 Set_Etype (N, Universal_Integer);
4397 Error_Attr_P ("prefix of % attribute must be access or task type");
4405 when Attribute_Storage_Unit =>
4406 Standard_Attribute (Ttypes.System_Storage_Unit);
4412 when Attribute_Stream_Size =>
4416 if Is_Entity_Name (P)
4417 and then Is_Elementary_Type (Entity (P))
4419 Set_Etype (N, Universal_Integer);
4421 Error_Attr_P ("invalid prefix for % attribute");
4428 when Attribute_Stub_Type =>
4432 if Is_Remote_Access_To_Class_Wide_Type (P_Type) then
4434 New_Occurrence_Of (Corresponding_Stub_Type (P_Type), Loc));
4437 ("prefix of% attribute must be remote access to classwide");
4444 when Attribute_Succ =>
4448 if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then
4449 Error_Msg_Name_1 := Aname;
4450 Error_Msg_Name_2 := Chars (P_Type);
4451 Check_Formal_Restriction
4452 ("attribute% is not allowed for type%", P);
4455 Resolve (E1, P_Base_Type);
4456 Set_Etype (N, P_Base_Type);
4458 -- Nothing to do for real type case
4460 if Is_Real_Type (P_Type) then
4463 -- If not modular type, test for overflow check required
4466 if not Is_Modular_Integer_Type (P_Type)
4467 and then not Range_Checks_Suppressed (P_Base_Type)
4469 Enable_Range_Check (E1);
4477 when Attribute_Tag => Tag :
4482 if not Is_Tagged_Type (P_Type) then
4483 Error_Attr_P ("prefix of % attribute must be tagged");
4485 -- Next test does not apply to generated code
4486 -- why not, and what does the illegal reference mean???
4488 elsif Is_Object_Reference (P)
4489 and then not Is_Class_Wide_Type (P_Type)
4490 and then Comes_From_Source (N)
4493 ("% attribute can only be applied to objects " &
4494 "of class - wide type");
4497 -- The prefix cannot be an incomplete type. However, references
4498 -- to 'Tag can be generated when expanding interface conversions,
4499 -- and this is legal.
4501 if Comes_From_Source (N) then
4502 Check_Not_Incomplete_Type;
4505 -- Set appropriate type
4507 Set_Etype (N, RTE (RE_Tag));
4514 when Attribute_Target_Name => Target_Name : declare
4515 TN : constant String := Sdefault.Target_Name.all;
4519 Check_Standard_Prefix;
4523 if TN (TL) = '/' or else TN (TL) = '\' then
4528 Make_String_Literal (Loc,
4529 Strval => TN (TN'First .. TL)));
4530 Analyze_And_Resolve (N, Standard_String);
4537 when Attribute_Terminated =>
4539 Set_Etype (N, Standard_Boolean);
4546 when Attribute_To_Address =>
4550 if Nkind (P) /= N_Identifier
4551 or else Chars (P) /= Name_System
4553 Error_Attr_P ("prefix of % attribute must be System");
4556 Generate_Reference (RTE (RE_Address), P);
4557 Analyze_And_Resolve (E1, Any_Integer);
4558 Set_Etype (N, RTE (RE_Address));
4564 when Attribute_To_Any =>
4566 Check_PolyORB_Attribute;
4567 Set_Etype (N, RTE (RE_Any));
4573 when Attribute_Truncation =>
4574 Check_Floating_Point_Type_1;
4575 Resolve (E1, P_Base_Type);
4576 Set_Etype (N, P_Base_Type);
4582 when Attribute_Type_Class =>
4585 Check_Not_Incomplete_Type;
4586 Set_Etype (N, RTE (RE_Type_Class));
4592 when Attribute_TypeCode =>
4594 Check_PolyORB_Attribute;
4595 Set_Etype (N, RTE (RE_TypeCode));
4601 when Attribute_Type_Key =>
4605 -- This processing belongs in Eval_Attribute ???
4608 function Type_Key return String_Id;
4609 -- A very preliminary implementation. For now, a signature
4610 -- consists of only the type name. This is clearly incomplete
4611 -- (e.g., adding a new field to a record type should change the
4612 -- type's Type_Key attribute).
4618 function Type_Key return String_Id is
4619 Full_Name : constant String_Id :=
4620 Fully_Qualified_Name_String (Entity (P));
4623 -- Copy all characters in Full_Name but the trailing NUL
4626 for J in 1 .. String_Length (Full_Name) - 1 loop
4627 Store_String_Char (Get_String_Char (Full_Name, Int (J)));
4630 Store_String_Chars ("'Type_Key");
4635 Rewrite (N, Make_String_Literal (Loc, Type_Key));
4638 Analyze_And_Resolve (N, Standard_String);
4644 when Attribute_UET_Address =>
4646 Check_Unit_Name (P);
4647 Set_Etype (N, RTE (RE_Address));
4649 -----------------------
4650 -- Unbiased_Rounding --
4651 -----------------------
4653 when Attribute_Unbiased_Rounding =>
4654 Check_Floating_Point_Type_1;
4655 Set_Etype (N, P_Base_Type);
4656 Resolve (E1, P_Base_Type);
4658 ----------------------
4659 -- Unchecked_Access --
4660 ----------------------
4662 when Attribute_Unchecked_Access =>
4663 if Comes_From_Source (N) then
4664 Check_Restriction (No_Unchecked_Access, N);
4667 Analyze_Access_Attribute;
4669 -------------------------
4670 -- Unconstrained_Array --
4671 -------------------------
4673 when Attribute_Unconstrained_Array =>
4676 Check_Not_Incomplete_Type;
4677 Set_Etype (N, Standard_Boolean);
4679 ------------------------------
4680 -- Universal_Literal_String --
4681 ------------------------------
4683 -- This is a GNAT specific attribute whose prefix must be a named
4684 -- number where the expression is either a single numeric literal,
4685 -- or a numeric literal immediately preceded by a minus sign. The
4686 -- result is equivalent to a string literal containing the text of
4687 -- the literal as it appeared in the source program with a possible
4688 -- leading minus sign.
4690 when Attribute_Universal_Literal_String => Universal_Literal_String :
4694 if not Is_Entity_Name (P)
4695 or else Ekind (Entity (P)) not in Named_Kind
4697 Error_Attr_P ("prefix for % attribute must be named number");
4704 Src : Source_Buffer_Ptr;
4707 Expr := Original_Node (Expression (Parent (Entity (P))));
4709 if Nkind (Expr) = N_Op_Minus then
4711 Expr := Original_Node (Right_Opnd (Expr));
4716 if not Nkind_In (Expr, N_Integer_Literal, N_Real_Literal) then
4718 ("named number for % attribute must be simple literal", N);
4721 -- Build string literal corresponding to source literal text
4726 Store_String_Char (Get_Char_Code ('-'));
4730 Src := Source_Text (Get_Source_File_Index (S));
4732 while Src (S) /= ';' and then Src (S) /= ' ' loop
4733 Store_String_Char (Get_Char_Code (Src (S)));
4737 -- Now we rewrite the attribute with the string literal
4740 Make_String_Literal (Loc, End_String));
4744 end Universal_Literal_String;
4746 -------------------------
4747 -- Unrestricted_Access --
4748 -------------------------
4750 -- This is a GNAT specific attribute which is like Access except that
4751 -- all scope checks and checks for aliased views are omitted.
4753 when Attribute_Unrestricted_Access =>
4754 if Comes_From_Source (N) then
4755 Check_Restriction (No_Unchecked_Access, N);
4758 if Is_Entity_Name (P) then
4759 Set_Address_Taken (Entity (P));
4762 Analyze_Access_Attribute;
4768 when Attribute_Val => Val : declare
4771 Check_Discrete_Type;
4773 if Is_Boolean_Type (P_Type) then
4774 Error_Msg_Name_1 := Aname;
4775 Error_Msg_Name_2 := Chars (P_Type);
4776 Check_Formal_Restriction
4777 ("attribute% is not allowed for type%", P);
4780 Resolve (E1, Any_Integer);
4781 Set_Etype (N, P_Base_Type);
4783 -- Note, we need a range check in general, but we wait for the
4784 -- Resolve call to do this, since we want to let Eval_Attribute
4785 -- have a chance to find an static illegality first!
4792 when Attribute_Valid =>
4795 -- Ignore check for object if we have a 'Valid reference generated
4796 -- by the expanded code, since in some cases valid checks can occur
4797 -- on items that are names, but are not objects (e.g. attributes).
4799 if Comes_From_Source (N) then
4800 Check_Object_Reference (P);
4803 if not Is_Scalar_Type (P_Type) then
4804 Error_Attr_P ("object for % attribute must be of scalar type");
4807 Set_Etype (N, Standard_Boolean);
4813 when Attribute_Value => Value :
4815 Check_Formal_Restriction_On_Attribute;
4819 -- Case of enumeration type
4821 if Is_Enumeration_Type (P_Type) then
4822 Check_Restriction (No_Enumeration_Maps, N);
4824 -- Mark all enumeration literals as referenced, since the use of
4825 -- the Value attribute can implicitly reference any of the
4826 -- literals of the enumeration base type.
4829 Ent : Entity_Id := First_Literal (P_Base_Type);
4831 while Present (Ent) loop
4832 Set_Referenced (Ent);
4838 -- Set Etype before resolving expression because expansion of
4839 -- expression may require enclosing type. Note that the type
4840 -- returned by 'Value is the base type of the prefix type.
4842 Set_Etype (N, P_Base_Type);
4843 Validate_Non_Static_Attribute_Function_Call;
4850 when Attribute_Value_Size =>
4853 Check_Not_Incomplete_Type;
4854 Set_Etype (N, Universal_Integer);
4860 when Attribute_Version =>
4863 Set_Etype (N, RTE (RE_Version_String));
4869 when Attribute_Wchar_T_Size =>
4870 Standard_Attribute (Interfaces_Wchar_T_Size);
4876 when Attribute_Wide_Image => Wide_Image :
4878 Check_Formal_Restriction_On_Attribute;
4880 Set_Etype (N, Standard_Wide_String);
4882 Resolve (E1, P_Base_Type);
4883 Validate_Non_Static_Attribute_Function_Call;
4886 ---------------------
4887 -- Wide_Wide_Image --
4888 ---------------------
4890 when Attribute_Wide_Wide_Image => Wide_Wide_Image :
4893 Set_Etype (N, Standard_Wide_Wide_String);
4895 Resolve (E1, P_Base_Type);
4896 Validate_Non_Static_Attribute_Function_Call;
4897 end Wide_Wide_Image;
4903 when Attribute_Wide_Value => Wide_Value :
4905 Check_Formal_Restriction_On_Attribute;
4909 -- Set Etype before resolving expression because expansion
4910 -- of expression may require enclosing type.
4912 Set_Etype (N, P_Type);
4913 Validate_Non_Static_Attribute_Function_Call;
4916 ---------------------
4917 -- Wide_Wide_Value --
4918 ---------------------
4920 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
4925 -- Set Etype before resolving expression because expansion
4926 -- of expression may require enclosing type.
4928 Set_Etype (N, P_Type);
4929 Validate_Non_Static_Attribute_Function_Call;
4930 end Wide_Wide_Value;
4932 ---------------------
4933 -- Wide_Wide_Width --
4934 ---------------------
4936 when Attribute_Wide_Wide_Width =>
4939 Set_Etype (N, Universal_Integer);
4945 when Attribute_Wide_Width =>
4946 Check_Formal_Restriction_On_Attribute;
4949 Set_Etype (N, Universal_Integer);
4955 when Attribute_Width =>
4956 Check_Formal_Restriction_On_Attribute;
4959 Set_Etype (N, Universal_Integer);
4965 when Attribute_Word_Size =>
4966 Standard_Attribute (System_Word_Size);
4972 when Attribute_Write =>
4974 Check_Stream_Attribute (TSS_Stream_Write);
4975 Set_Etype (N, Standard_Void_Type);
4976 Resolve (N, Standard_Void_Type);
4980 -- All errors raise Bad_Attribute, so that we get out before any further
4981 -- damage occurs when an error is detected (for example, if we check for
4982 -- one attribute expression, and the check succeeds, we want to be able
4983 -- to proceed securely assuming that an expression is in fact present.
4985 -- Note: we set the attribute analyzed in this case to prevent any
4986 -- attempt at reanalysis which could generate spurious error msgs.
4989 when Bad_Attribute =>
4991 Set_Etype (N, Any_Type);
4993 end Analyze_Attribute;
4995 --------------------
4996 -- Eval_Attribute --
4997 --------------------
4999 procedure Eval_Attribute (N : Node_Id) is
5000 Loc : constant Source_Ptr := Sloc (N);
5001 Aname : constant Name_Id := Attribute_Name (N);
5002 Id : constant Attribute_Id := Get_Attribute_Id (Aname);
5003 P : constant Node_Id := Prefix (N);
5005 C_Type : constant Entity_Id := Etype (N);
5006 -- The type imposed by the context
5009 -- First expression, or Empty if none
5012 -- Second expression, or Empty if none
5014 P_Entity : Entity_Id;
5015 -- Entity denoted by prefix
5018 -- The type of the prefix
5020 P_Base_Type : Entity_Id;
5021 -- The base type of the prefix type
5023 P_Root_Type : Entity_Id;
5024 -- The root type of the prefix type
5027 -- True if the result is Static. This is set by the general processing
5028 -- to true if the prefix is static, and all expressions are static. It
5029 -- can be reset as processing continues for particular attributes
5031 Lo_Bound, Hi_Bound : Node_Id;
5032 -- Expressions for low and high bounds of type or array index referenced
5033 -- by First, Last, or Length attribute for array, set by Set_Bounds.
5036 -- Constraint error node used if we have an attribute reference has
5037 -- an argument that raises a constraint error. In this case we replace
5038 -- the attribute with a raise constraint_error node. This is important
5039 -- processing, since otherwise gigi might see an attribute which it is
5040 -- unprepared to deal with.
5042 procedure Check_Concurrent_Discriminant (Bound : Node_Id);
5043 -- If Bound is a reference to a discriminant of a task or protected type
5044 -- occurring within the object's body, rewrite attribute reference into
5045 -- a reference to the corresponding discriminal. Use for the expansion
5046 -- of checks against bounds of entry family index subtypes.
5048 procedure Check_Expressions;
5049 -- In case where the attribute is not foldable, the expressions, if
5050 -- any, of the attribute, are in a non-static context. This procedure
5051 -- performs the required additional checks.
5053 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean;
5054 -- Determines if the given type has compile time known bounds. Note
5055 -- that we enter the case statement even in cases where the prefix
5056 -- type does NOT have known bounds, so it is important to guard any
5057 -- attempt to evaluate both bounds with a call to this function.
5059 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint);
5060 -- This procedure is called when the attribute N has a non-static
5061 -- but compile time known value given by Val. It includes the
5062 -- necessary checks for out of range values.
5064 function Fore_Value return Nat;
5065 -- Computes the Fore value for the current attribute prefix, which is
5066 -- known to be a static fixed-point type. Used by Fore and Width.
5068 function Mantissa return Uint;
5069 -- Returns the Mantissa value for the prefix type
5071 procedure Set_Bounds;
5072 -- Used for First, Last and Length attributes applied to an array or
5073 -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low
5074 -- and high bound expressions for the index referenced by the attribute
5075 -- designator (i.e. the first index if no expression is present, and
5076 -- the N'th index if the value N is present as an expression). Also
5077 -- used for First and Last of scalar types. Static is reset to False
5078 -- if the type or index type is not statically constrained.
5080 function Statically_Denotes_Entity (N : Node_Id) return Boolean;
5081 -- Verify that the prefix of a potentially static array attribute
5082 -- satisfies the conditions of 4.9 (14).
5084 -----------------------------------
5085 -- Check_Concurrent_Discriminant --
5086 -----------------------------------
5088 procedure Check_Concurrent_Discriminant (Bound : Node_Id) is
5090 -- The concurrent (task or protected) type
5093 if Nkind (Bound) = N_Identifier
5094 and then Ekind (Entity (Bound)) = E_Discriminant
5095 and then Is_Concurrent_Record_Type (Scope (Entity (Bound)))
5097 Tsk := Corresponding_Concurrent_Type (Scope (Entity (Bound)));
5099 if In_Open_Scopes (Tsk) and then Has_Completion (Tsk) then
5101 -- Find discriminant of original concurrent type, and use
5102 -- its current discriminal, which is the renaming within
5103 -- the task/protected body.
5107 (Find_Body_Discriminal (Entity (Bound)), Loc));
5110 end Check_Concurrent_Discriminant;
5112 -----------------------
5113 -- Check_Expressions --
5114 -----------------------
5116 procedure Check_Expressions is
5120 while Present (E) loop
5121 Check_Non_Static_Context (E);
5124 end Check_Expressions;
5126 ----------------------------------
5127 -- Compile_Time_Known_Attribute --
5128 ----------------------------------
5130 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint) is
5131 T : constant Entity_Id := Etype (N);
5134 Fold_Uint (N, Val, False);
5136 -- Check that result is in bounds of the type if it is static
5138 if Is_In_Range (N, T, Assume_Valid => False) then
5141 elsif Is_Out_Of_Range (N, T) then
5142 Apply_Compile_Time_Constraint_Error
5143 (N, "value not in range of}?", CE_Range_Check_Failed);
5145 elsif not Range_Checks_Suppressed (T) then
5146 Enable_Range_Check (N);
5149 Set_Do_Range_Check (N, False);
5151 end Compile_Time_Known_Attribute;
5153 -------------------------------
5154 -- Compile_Time_Known_Bounds --
5155 -------------------------------
5157 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean is
5160 Compile_Time_Known_Value (Type_Low_Bound (Typ))
5162 Compile_Time_Known_Value (Type_High_Bound (Typ));
5163 end Compile_Time_Known_Bounds;
5169 -- Note that the Fore calculation is based on the actual values
5170 -- of the bounds, and does not take into account possible rounding.
5172 function Fore_Value return Nat is
5173 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
5174 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
5175 Small : constant Ureal := Small_Value (P_Type);
5176 Lo_Real : constant Ureal := Lo * Small;
5177 Hi_Real : constant Ureal := Hi * Small;
5182 -- Bounds are given in terms of small units, so first compute
5183 -- proper values as reals.
5185 T := UR_Max (abs Lo_Real, abs Hi_Real);
5188 -- Loop to compute proper value if more than one digit required
5190 while T >= Ureal_10 loop
5202 -- Table of mantissa values accessed by function Computed using
5205 -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1)
5207 -- where D is T'Digits (RM83 3.5.7)
5209 Mantissa_Value : constant array (Nat range 1 .. 40) of Nat := (
5251 function Mantissa return Uint is
5254 UI_From_Int (Mantissa_Value (UI_To_Int (Digits_Value (P_Type))));
5261 procedure Set_Bounds is
5267 -- For a string literal subtype, we have to construct the bounds.
5268 -- Valid Ada code never applies attributes to string literals, but
5269 -- it is convenient to allow the expander to generate attribute
5270 -- references of this type (e.g. First and Last applied to a string
5273 -- Note that the whole point of the E_String_Literal_Subtype is to
5274 -- avoid this construction of bounds, but the cases in which we
5275 -- have to materialize them are rare enough that we don't worry!
5277 -- The low bound is simply the low bound of the base type. The
5278 -- high bound is computed from the length of the string and this
5281 if Ekind (P_Type) = E_String_Literal_Subtype then
5282 Ityp := Etype (First_Index (Base_Type (P_Type)));
5283 Lo_Bound := Type_Low_Bound (Ityp);
5286 Make_Integer_Literal (Sloc (P),
5288 Expr_Value (Lo_Bound) + String_Literal_Length (P_Type) - 1);
5290 Set_Parent (Hi_Bound, P);
5291 Analyze_And_Resolve (Hi_Bound, Etype (Lo_Bound));
5294 -- For non-array case, just get bounds of scalar type
5296 elsif Is_Scalar_Type (P_Type) then
5299 -- For a fixed-point type, we must freeze to get the attributes
5300 -- of the fixed-point type set now so we can reference them.
5302 if Is_Fixed_Point_Type (P_Type)
5303 and then not Is_Frozen (Base_Type (P_Type))
5304 and then Compile_Time_Known_Value (Type_Low_Bound (P_Type))
5305 and then Compile_Time_Known_Value (Type_High_Bound (P_Type))
5307 Freeze_Fixed_Point_Type (Base_Type (P_Type));
5310 -- For array case, get type of proper index
5316 Ndim := UI_To_Int (Expr_Value (E1));
5319 Indx := First_Index (P_Type);
5320 for J in 1 .. Ndim - 1 loop
5324 -- If no index type, get out (some other error occurred, and
5325 -- we don't have enough information to complete the job!)
5333 Ityp := Etype (Indx);
5336 -- A discrete range in an index constraint is allowed to be a
5337 -- subtype indication. This is syntactically a pain, but should
5338 -- not propagate to the entity for the corresponding index subtype.
5339 -- After checking that the subtype indication is legal, the range
5340 -- of the subtype indication should be transfered to the entity.
5341 -- The attributes for the bounds should remain the simple retrievals
5342 -- that they are now.
5344 Lo_Bound := Type_Low_Bound (Ityp);
5345 Hi_Bound := Type_High_Bound (Ityp);
5347 if not Is_Static_Subtype (Ityp) then
5352 -------------------------------
5353 -- Statically_Denotes_Entity --
5354 -------------------------------
5356 function Statically_Denotes_Entity (N : Node_Id) return Boolean is
5360 if not Is_Entity_Name (N) then
5367 Nkind (Parent (E)) /= N_Object_Renaming_Declaration
5368 or else Statically_Denotes_Entity (Renamed_Object (E));
5369 end Statically_Denotes_Entity;
5371 -- Start of processing for Eval_Attribute
5374 -- No folding in spec expression that comes from source where the prefix
5375 -- is an unfrozen entity. This avoids premature folding in cases like:
5377 -- procedure DefExprAnal is
5378 -- type R is new Integer;
5379 -- procedure P (Arg : Integer := R'Size);
5380 -- for R'Size use 64;
5381 -- procedure P (Arg : Integer := R'Size) is
5383 -- Put_Line (Arg'Img);
5389 -- which should print 64 rather than 32. The exclusion of non-source
5390 -- constructs from this test comes from some internal usage in packed
5391 -- arrays, which otherwise fails, could use more analysis perhaps???
5393 -- We do however go ahead with generic actual types, otherwise we get
5394 -- some regressions, probably these types should be frozen anyway???
5396 if In_Spec_Expression
5397 and then Comes_From_Source (N)
5398 and then not (Is_Entity_Name (P)
5400 (Is_Frozen (Entity (P))
5401 or else (Is_Type (Entity (P))
5403 Is_Generic_Actual_Type (Entity (P)))))
5408 -- Acquire first two expressions (at the moment, no attributes take more
5409 -- than two expressions in any case).
5411 if Present (Expressions (N)) then
5412 E1 := First (Expressions (N));
5419 -- Special processing for Enabled attribute. This attribute has a very
5420 -- special prefix, and the easiest way to avoid lots of special checks
5421 -- to protect this special prefix from causing trouble is to deal with
5422 -- this attribute immediately and be done with it.
5424 if Id = Attribute_Enabled then
5426 -- We skip evaluation if the expander is not active. This is not just
5427 -- an optimization. It is of key importance that we not rewrite the
5428 -- attribute in a generic template, since we want to pick up the
5429 -- setting of the check in the instance, and testing expander active
5430 -- is as easy way of doing this as any.
5432 if Expander_Active then
5434 C : constant Check_Id := Get_Check_Id (Chars (P));
5439 if C in Predefined_Check_Id then
5440 R := Scope_Suppress (C);
5442 R := Is_Check_Suppressed (Empty, C);
5446 R := Is_Check_Suppressed (Entity (E1), C);
5450 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
5452 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
5460 -- Special processing for cases where the prefix is an object. For
5461 -- this purpose, a string literal counts as an object (attributes
5462 -- of string literals can only appear in generated code).
5464 if Is_Object_Reference (P) or else Nkind (P) = N_String_Literal then
5466 -- For Component_Size, the prefix is an array object, and we apply
5467 -- the attribute to the type of the object. This is allowed for
5468 -- both unconstrained and constrained arrays, since the bounds
5469 -- have no influence on the value of this attribute.
5471 if Id = Attribute_Component_Size then
5472 P_Entity := Etype (P);
5474 -- For First and Last, the prefix is an array object, and we apply
5475 -- the attribute to the type of the array, but we need a constrained
5476 -- type for this, so we use the actual subtype if available.
5478 elsif Id = Attribute_First
5482 Id = Attribute_Length
5485 AS : constant Entity_Id := Get_Actual_Subtype_If_Available (P);
5488 if Present (AS) and then Is_Constrained (AS) then
5491 -- If we have an unconstrained type we cannot fold
5499 -- For Size, give size of object if available, otherwise we
5500 -- cannot fold Size.
5502 elsif Id = Attribute_Size then
5503 if Is_Entity_Name (P)
5504 and then Known_Esize (Entity (P))
5506 Compile_Time_Known_Attribute (N, Esize (Entity (P)));
5514 -- For Alignment, give size of object if available, otherwise we
5515 -- cannot fold Alignment.
5517 elsif Id = Attribute_Alignment then
5518 if Is_Entity_Name (P)
5519 and then Known_Alignment (Entity (P))
5521 Fold_Uint (N, Alignment (Entity (P)), False);
5529 -- No other attributes for objects are folded
5536 -- Cases where P is not an object. Cannot do anything if P is
5537 -- not the name of an entity.
5539 elsif not Is_Entity_Name (P) then
5543 -- Otherwise get prefix entity
5546 P_Entity := Entity (P);
5549 -- At this stage P_Entity is the entity to which the attribute
5550 -- is to be applied. This is usually simply the entity of the
5551 -- prefix, except in some cases of attributes for objects, where
5552 -- as described above, we apply the attribute to the object type.
5554 -- First foldable possibility is a scalar or array type (RM 4.9(7))
5555 -- that is not generic (generic types are eliminated by RM 4.9(25)).
5556 -- Note we allow non-static non-generic types at this stage as further
5559 if Is_Type (P_Entity)
5560 and then (Is_Scalar_Type (P_Entity) or Is_Array_Type (P_Entity))
5561 and then (not Is_Generic_Type (P_Entity))
5565 -- Second foldable possibility is an array object (RM 4.9(8))
5567 elsif (Ekind (P_Entity) = E_Variable
5569 Ekind (P_Entity) = E_Constant)
5570 and then Is_Array_Type (Etype (P_Entity))
5571 and then (not Is_Generic_Type (Etype (P_Entity)))
5573 P_Type := Etype (P_Entity);
5575 -- If the entity is an array constant with an unconstrained nominal
5576 -- subtype then get the type from the initial value. If the value has
5577 -- been expanded into assignments, there is no expression and the
5578 -- attribute reference remains dynamic.
5580 -- We could do better here and retrieve the type ???
5582 if Ekind (P_Entity) = E_Constant
5583 and then not Is_Constrained (P_Type)
5585 if No (Constant_Value (P_Entity)) then
5588 P_Type := Etype (Constant_Value (P_Entity));
5592 -- Definite must be folded if the prefix is not a generic type,
5593 -- that is to say if we are within an instantiation. Same processing
5594 -- applies to the GNAT attributes Has_Discriminants, Type_Class,
5595 -- Has_Tagged_Value, and Unconstrained_Array.
5597 elsif (Id = Attribute_Definite
5599 Id = Attribute_Has_Access_Values
5601 Id = Attribute_Has_Discriminants
5603 Id = Attribute_Has_Tagged_Values
5605 Id = Attribute_Type_Class
5607 Id = Attribute_Unconstrained_Array
5609 Id = Attribute_Max_Alignment_For_Allocation)
5610 and then not Is_Generic_Type (P_Entity)
5614 -- We can fold 'Size applied to a type if the size is known (as happens
5615 -- for a size from an attribute definition clause). At this stage, this
5616 -- can happen only for types (e.g. record types) for which the size is
5617 -- always non-static. We exclude generic types from consideration (since
5618 -- they have bogus sizes set within templates).
5620 elsif Id = Attribute_Size
5621 and then Is_Type (P_Entity)
5622 and then (not Is_Generic_Type (P_Entity))
5623 and then Known_Static_RM_Size (P_Entity)
5625 Compile_Time_Known_Attribute (N, RM_Size (P_Entity));
5628 -- We can fold 'Alignment applied to a type if the alignment is known
5629 -- (as happens for an alignment from an attribute definition clause).
5630 -- At this stage, this can happen only for types (e.g. record
5631 -- types) for which the size is always non-static. We exclude
5632 -- generic types from consideration (since they have bogus
5633 -- sizes set within templates).
5635 elsif Id = Attribute_Alignment
5636 and then Is_Type (P_Entity)
5637 and then (not Is_Generic_Type (P_Entity))
5638 and then Known_Alignment (P_Entity)
5640 Compile_Time_Known_Attribute (N, Alignment (P_Entity));
5643 -- If this is an access attribute that is known to fail accessibility
5644 -- check, rewrite accordingly.
5646 elsif Attribute_Name (N) = Name_Access
5647 and then Raises_Constraint_Error (N)
5650 Make_Raise_Program_Error (Loc,
5651 Reason => PE_Accessibility_Check_Failed));
5652 Set_Etype (N, C_Type);
5655 -- No other cases are foldable (they certainly aren't static, and at
5656 -- the moment we don't try to fold any cases other than these three).
5663 -- If either attribute or the prefix is Any_Type, then propagate
5664 -- Any_Type to the result and don't do anything else at all.
5666 if P_Type = Any_Type
5667 or else (Present (E1) and then Etype (E1) = Any_Type)
5668 or else (Present (E2) and then Etype (E2) = Any_Type)
5670 Set_Etype (N, Any_Type);
5674 -- Scalar subtype case. We have not yet enforced the static requirement
5675 -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases
5676 -- of non-static attribute references (e.g. S'Digits for a non-static
5677 -- floating-point type, which we can compute at compile time).
5679 -- Note: this folding of non-static attributes is not simply a case of
5680 -- optimization. For many of the attributes affected, Gigi cannot handle
5681 -- the attribute and depends on the front end having folded them away.
5683 -- Note: although we don't require staticness at this stage, we do set
5684 -- the Static variable to record the staticness, for easy reference by
5685 -- those attributes where it matters (e.g. Succ and Pred), and also to
5686 -- be used to ensure that non-static folded things are not marked as
5687 -- being static (a check that is done right at the end).
5689 P_Root_Type := Root_Type (P_Type);
5690 P_Base_Type := Base_Type (P_Type);
5692 -- If the root type or base type is generic, then we cannot fold. This
5693 -- test is needed because subtypes of generic types are not always
5694 -- marked as being generic themselves (which seems odd???)
5696 if Is_Generic_Type (P_Root_Type)
5697 or else Is_Generic_Type (P_Base_Type)
5702 if Is_Scalar_Type (P_Type) then
5703 Static := Is_OK_Static_Subtype (P_Type);
5705 -- Array case. We enforce the constrained requirement of (RM 4.9(7-8))
5706 -- since we can't do anything with unconstrained arrays. In addition,
5707 -- only the First, Last and Length attributes are possibly static.
5709 -- Definite, Has_Access_Values, Has_Discriminants, Has_Tagged_Values,
5710 -- Type_Class, and Unconstrained_Array are again exceptions, because
5711 -- they apply as well to unconstrained types.
5713 -- In addition Component_Size is an exception since it is possibly
5714 -- foldable, even though it is never static, and it does apply to
5715 -- unconstrained arrays. Furthermore, it is essential to fold this
5716 -- in the packed case, since otherwise the value will be incorrect.
5718 elsif Id = Attribute_Definite
5720 Id = Attribute_Has_Access_Values
5722 Id = Attribute_Has_Discriminants
5724 Id = Attribute_Has_Tagged_Values
5726 Id = Attribute_Type_Class
5728 Id = Attribute_Unconstrained_Array
5730 Id = Attribute_Component_Size
5734 elsif Id /= Attribute_Max_Alignment_For_Allocation then
5735 if not Is_Constrained (P_Type)
5736 or else (Id /= Attribute_First and then
5737 Id /= Attribute_Last and then
5738 Id /= Attribute_Length)
5744 -- The rules in (RM 4.9(7,8)) require a static array, but as in the
5745 -- scalar case, we hold off on enforcing staticness, since there are
5746 -- cases which we can fold at compile time even though they are not
5747 -- static (e.g. 'Length applied to a static index, even though other
5748 -- non-static indexes make the array type non-static). This is only
5749 -- an optimization, but it falls out essentially free, so why not.
5750 -- Again we compute the variable Static for easy reference later
5751 -- (note that no array attributes are static in Ada 83).
5753 -- We also need to set Static properly for subsequent legality checks
5754 -- which might otherwise accept non-static constants in contexts
5755 -- where they are not legal.
5757 Static := Ada_Version >= Ada_95
5758 and then Statically_Denotes_Entity (P);
5764 N := First_Index (P_Type);
5766 -- The expression is static if the array type is constrained
5767 -- by given bounds, and not by an initial expression. Constant
5768 -- strings are static in any case.
5770 if Root_Type (P_Type) /= Standard_String then
5772 Static and then not Is_Constr_Subt_For_U_Nominal (P_Type);
5775 while Present (N) loop
5776 Static := Static and then Is_Static_Subtype (Etype (N));
5778 -- If however the index type is generic, or derived from
5779 -- one, attributes cannot be folded.
5781 if Is_Generic_Type (Root_Type (Etype (N)))
5782 and then Id /= Attribute_Component_Size
5792 -- Check any expressions that are present. Note that these expressions,
5793 -- depending on the particular attribute type, are either part of the
5794 -- attribute designator, or they are arguments in a case where the
5795 -- attribute reference returns a function. In the latter case, the
5796 -- rule in (RM 4.9(22)) applies and in particular requires the type
5797 -- of the expressions to be scalar in order for the attribute to be
5798 -- considered to be static.
5805 while Present (E) loop
5807 -- If expression is not static, then the attribute reference
5808 -- result certainly cannot be static.
5810 if not Is_Static_Expression (E) then
5814 -- If the result is not known at compile time, or is not of
5815 -- a scalar type, then the result is definitely not static,
5816 -- so we can quit now.
5818 if not Compile_Time_Known_Value (E)
5819 or else not Is_Scalar_Type (Etype (E))
5821 -- An odd special case, if this is a Pos attribute, this
5822 -- is where we need to apply a range check since it does
5823 -- not get done anywhere else.
5825 if Id = Attribute_Pos then
5826 if Is_Integer_Type (Etype (E)) then
5827 Apply_Range_Check (E, Etype (N));
5834 -- If the expression raises a constraint error, then so does
5835 -- the attribute reference. We keep going in this case because
5836 -- we are still interested in whether the attribute reference
5837 -- is static even if it is not static.
5839 elsif Raises_Constraint_Error (E) then
5840 Set_Raises_Constraint_Error (N);
5846 if Raises_Constraint_Error (Prefix (N)) then
5851 -- Deal with the case of a static attribute reference that raises
5852 -- constraint error. The Raises_Constraint_Error flag will already
5853 -- have been set, and the Static flag shows whether the attribute
5854 -- reference is static. In any case we certainly can't fold such an
5855 -- attribute reference.
5857 -- Note that the rewriting of the attribute node with the constraint
5858 -- error node is essential in this case, because otherwise Gigi might
5859 -- blow up on one of the attributes it never expects to see.
5861 -- The constraint_error node must have the type imposed by the context,
5862 -- to avoid spurious errors in the enclosing expression.
5864 if Raises_Constraint_Error (N) then
5866 Make_Raise_Constraint_Error (Sloc (N),
5867 Reason => CE_Range_Check_Failed);
5868 Set_Etype (CE_Node, Etype (N));
5869 Set_Raises_Constraint_Error (CE_Node);
5871 Rewrite (N, Relocate_Node (CE_Node));
5872 Set_Is_Static_Expression (N, Static);
5876 -- At this point we have a potentially foldable attribute reference.
5877 -- If Static is set, then the attribute reference definitely obeys
5878 -- the requirements in (RM 4.9(7,8,22)), and it definitely can be
5879 -- folded. If Static is not set, then the attribute may or may not
5880 -- be foldable, and the individual attribute processing routines
5881 -- test Static as required in cases where it makes a difference.
5883 -- In the case where Static is not set, we do know that all the
5884 -- expressions present are at least known at compile time (we
5885 -- assumed above that if this was not the case, then there was
5886 -- no hope of static evaluation). However, we did not require
5887 -- that the bounds of the prefix type be compile time known,
5888 -- let alone static). That's because there are many attributes
5889 -- that can be computed at compile time on non-static subtypes,
5890 -- even though such references are not static expressions.
5898 when Attribute_Adjacent =>
5901 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
5907 when Attribute_Aft =>
5908 Fold_Uint (N, Aft_Value (P_Type), True);
5914 when Attribute_Alignment => Alignment_Block : declare
5915 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
5918 -- Fold if alignment is set and not otherwise
5920 if Known_Alignment (P_TypeA) then
5921 Fold_Uint (N, Alignment (P_TypeA), Is_Discrete_Type (P_TypeA));
5923 end Alignment_Block;
5929 -- Can only be folded in No_Ast_Handler case
5931 when Attribute_AST_Entry =>
5932 if not Is_AST_Entry (P_Entity) then
5934 New_Occurrence_Of (RTE (RE_No_AST_Handler), Loc));
5943 -- Bit can never be folded
5945 when Attribute_Bit =>
5952 -- Body_version can never be static
5954 when Attribute_Body_Version =>
5961 when Attribute_Ceiling =>
5963 Eval_Fat.Ceiling (P_Root_Type, Expr_Value_R (E1)), Static);
5965 --------------------
5966 -- Component_Size --
5967 --------------------
5969 when Attribute_Component_Size =>
5970 if Known_Static_Component_Size (P_Type) then
5971 Fold_Uint (N, Component_Size (P_Type), False);
5978 when Attribute_Compose =>
5981 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)),
5988 -- Constrained is never folded for now, there may be cases that
5989 -- could be handled at compile time. To be looked at later.
5991 when Attribute_Constrained =>
5998 when Attribute_Copy_Sign =>
6001 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6007 when Attribute_Delta =>
6008 Fold_Ureal (N, Delta_Value (P_Type), True);
6014 when Attribute_Definite =>
6015 Rewrite (N, New_Occurrence_Of (
6016 Boolean_Literals (not Is_Indefinite_Subtype (P_Entity)), Loc));
6017 Analyze_And_Resolve (N, Standard_Boolean);
6023 when Attribute_Denorm =>
6025 (N, UI_From_Int (Boolean'Pos (Denorm_On_Target)), True);
6031 when Attribute_Digits =>
6032 Fold_Uint (N, Digits_Value (P_Type), True);
6038 when Attribute_Emax =>
6040 -- Ada 83 attribute is defined as (RM83 3.5.8)
6042 -- T'Emax = 4 * T'Mantissa
6044 Fold_Uint (N, 4 * Mantissa, True);
6050 when Attribute_Enum_Rep =>
6052 -- For an enumeration type with a non-standard representation use
6053 -- the Enumeration_Rep field of the proper constant. Note that this
6054 -- will not work for types Character/Wide_[Wide-]Character, since no
6055 -- real entities are created for the enumeration literals, but that
6056 -- does not matter since these two types do not have non-standard
6057 -- representations anyway.
6059 if Is_Enumeration_Type (P_Type)
6060 and then Has_Non_Standard_Rep (P_Type)
6062 Fold_Uint (N, Enumeration_Rep (Expr_Value_E (E1)), Static);
6064 -- For enumeration types with standard representations and all
6065 -- other cases (i.e. all integer and modular types), Enum_Rep
6066 -- is equivalent to Pos.
6069 Fold_Uint (N, Expr_Value (E1), Static);
6076 when Attribute_Enum_Val => Enum_Val : declare
6080 -- We have something like Enum_Type'Enum_Val (23), so search for a
6081 -- corresponding value in the list of Enum_Rep values for the type.
6083 Lit := First_Literal (P_Base_Type);
6085 if Enumeration_Rep (Lit) = Expr_Value (E1) then
6086 Fold_Uint (N, Enumeration_Pos (Lit), Static);
6093 Apply_Compile_Time_Constraint_Error
6094 (N, "no representation value matches",
6095 CE_Range_Check_Failed,
6096 Warn => not Static);
6106 when Attribute_Epsilon =>
6108 -- Ada 83 attribute is defined as (RM83 3.5.8)
6110 -- T'Epsilon = 2.0**(1 - T'Mantissa)
6112 Fold_Ureal (N, Ureal_2 ** (1 - Mantissa), True);
6118 when Attribute_Exponent =>
6120 Eval_Fat.Exponent (P_Root_Type, Expr_Value_R (E1)), Static);
6126 when Attribute_First => First_Attr :
6130 if Compile_Time_Known_Value (Lo_Bound) then
6131 if Is_Real_Type (P_Type) then
6132 Fold_Ureal (N, Expr_Value_R (Lo_Bound), Static);
6134 Fold_Uint (N, Expr_Value (Lo_Bound), Static);
6138 Check_Concurrent_Discriminant (Lo_Bound);
6146 when Attribute_Fixed_Value =>
6153 when Attribute_Floor =>
6155 Eval_Fat.Floor (P_Root_Type, Expr_Value_R (E1)), Static);
6161 when Attribute_Fore =>
6162 if Compile_Time_Known_Bounds (P_Type) then
6163 Fold_Uint (N, UI_From_Int (Fore_Value), Static);
6170 when Attribute_Fraction =>
6172 Eval_Fat.Fraction (P_Root_Type, Expr_Value_R (E1)), Static);
6174 -----------------------
6175 -- Has_Access_Values --
6176 -----------------------
6178 when Attribute_Has_Access_Values =>
6179 Rewrite (N, New_Occurrence_Of
6180 (Boolean_Literals (Has_Access_Values (P_Root_Type)), Loc));
6181 Analyze_And_Resolve (N, Standard_Boolean);
6183 -----------------------
6184 -- Has_Discriminants --
6185 -----------------------
6187 when Attribute_Has_Discriminants =>
6188 Rewrite (N, New_Occurrence_Of (
6189 Boolean_Literals (Has_Discriminants (P_Entity)), Loc));
6190 Analyze_And_Resolve (N, Standard_Boolean);
6192 -----------------------
6193 -- Has_Tagged_Values --
6194 -----------------------
6196 when Attribute_Has_Tagged_Values =>
6197 Rewrite (N, New_Occurrence_Of
6198 (Boolean_Literals (Has_Tagged_Component (P_Root_Type)), Loc));
6199 Analyze_And_Resolve (N, Standard_Boolean);
6205 when Attribute_Identity =>
6212 -- Image is a scalar attribute, but is never static, because it is
6213 -- not a static function (having a non-scalar argument (RM 4.9(22))
6214 -- However, we can constant-fold the image of an enumeration literal
6215 -- if names are available.
6217 when Attribute_Image =>
6218 if Is_Entity_Name (E1)
6219 and then Ekind (Entity (E1)) = E_Enumeration_Literal
6220 and then not Discard_Names (First_Subtype (Etype (E1)))
6221 and then not Global_Discard_Names
6224 Lit : constant Entity_Id := Entity (E1);
6228 Get_Unqualified_Decoded_Name_String (Chars (Lit));
6229 Set_Casing (All_Upper_Case);
6230 Store_String_Chars (Name_Buffer (1 .. Name_Len));
6232 Rewrite (N, Make_String_Literal (Loc, Strval => Str));
6233 Analyze_And_Resolve (N, Standard_String);
6234 Set_Is_Static_Expression (N, False);
6242 -- Img is a scalar attribute, but is never static, because it is
6243 -- not a static function (having a non-scalar argument (RM 4.9(22))
6245 when Attribute_Img =>
6252 -- We never try to fold Integer_Value (though perhaps we could???)
6254 when Attribute_Integer_Value =>
6261 -- Invalid_Value is a scalar attribute that is never static, because
6262 -- the value is by design out of range.
6264 when Attribute_Invalid_Value =>
6271 when Attribute_Large =>
6273 -- For fixed-point, we use the identity:
6275 -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small
6277 if Is_Fixed_Point_Type (P_Type) then
6279 Make_Op_Multiply (Loc,
6281 Make_Op_Subtract (Loc,
6285 Make_Real_Literal (Loc, Ureal_2),
6287 Make_Attribute_Reference (Loc,
6289 Attribute_Name => Name_Mantissa)),
6290 Right_Opnd => Make_Real_Literal (Loc, Ureal_1)),
6293 Make_Real_Literal (Loc, Small_Value (Entity (P)))));
6295 Analyze_And_Resolve (N, C_Type);
6297 -- Floating-point (Ada 83 compatibility)
6300 -- Ada 83 attribute is defined as (RM83 3.5.8)
6302 -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa))
6306 -- T'Emax = 4 * T'Mantissa
6309 Ureal_2 ** (4 * Mantissa) * (Ureal_1 - Ureal_2 ** (-Mantissa)),
6317 when Attribute_Last => Last :
6321 if Compile_Time_Known_Value (Hi_Bound) then
6322 if Is_Real_Type (P_Type) then
6323 Fold_Ureal (N, Expr_Value_R (Hi_Bound), Static);
6325 Fold_Uint (N, Expr_Value (Hi_Bound), Static);
6329 Check_Concurrent_Discriminant (Hi_Bound);
6337 when Attribute_Leading_Part =>
6339 Eval_Fat.Leading_Part
6340 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
6346 when Attribute_Length => Length : declare
6350 -- If any index type is a formal type, or derived from one, the
6351 -- bounds are not static. Treating them as static can produce
6352 -- spurious warnings or improper constant folding.
6354 Ind := First_Index (P_Type);
6355 while Present (Ind) loop
6356 if Is_Generic_Type (Root_Type (Etype (Ind))) then
6365 -- For two compile time values, we can compute length
6367 if Compile_Time_Known_Value (Lo_Bound)
6368 and then Compile_Time_Known_Value (Hi_Bound)
6371 UI_Max (0, 1 + (Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound))),
6375 -- One more case is where Hi_Bound and Lo_Bound are compile-time
6376 -- comparable, and we can figure out the difference between them.
6379 Diff : aliased Uint;
6383 Compile_Time_Compare
6384 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
6387 Fold_Uint (N, Uint_1, False);
6390 Fold_Uint (N, Uint_0, False);
6393 if Diff /= No_Uint then
6394 Fold_Uint (N, Diff + 1, False);
6407 when Attribute_Machine =>
6410 (P_Root_Type, Expr_Value_R (E1), Eval_Fat.Round, N),
6417 when Attribute_Machine_Emax =>
6418 Fold_Uint (N, Machine_Emax_Value (P_Type), Static);
6424 when Attribute_Machine_Emin =>
6425 Fold_Uint (N, Machine_Emin_Value (P_Type), Static);
6427 ----------------------
6428 -- Machine_Mantissa --
6429 ----------------------
6431 when Attribute_Machine_Mantissa =>
6432 Fold_Uint (N, Machine_Mantissa_Value (P_Type), Static);
6434 -----------------------
6435 -- Machine_Overflows --
6436 -----------------------
6438 when Attribute_Machine_Overflows =>
6440 -- Always true for fixed-point
6442 if Is_Fixed_Point_Type (P_Type) then
6443 Fold_Uint (N, True_Value, True);
6445 -- Floating point case
6449 UI_From_Int (Boolean'Pos (Machine_Overflows_On_Target)),
6457 when Attribute_Machine_Radix =>
6458 if Is_Fixed_Point_Type (P_Type) then
6459 if Is_Decimal_Fixed_Point_Type (P_Type)
6460 and then Machine_Radix_10 (P_Type)
6462 Fold_Uint (N, Uint_10, True);
6464 Fold_Uint (N, Uint_2, True);
6467 -- All floating-point type always have radix 2
6470 Fold_Uint (N, Uint_2, True);
6473 ----------------------
6474 -- Machine_Rounding --
6475 ----------------------
6477 -- Note: for the folding case, it is fine to treat Machine_Rounding
6478 -- exactly the same way as Rounding, since this is one of the allowed
6479 -- behaviors, and performance is not an issue here. It might be a bit
6480 -- better to give the same result as it would give at run time, even
6481 -- though the non-determinism is certainly permitted.
6483 when Attribute_Machine_Rounding =>
6485 Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static);
6487 --------------------
6488 -- Machine_Rounds --
6489 --------------------
6491 when Attribute_Machine_Rounds =>
6493 -- Always False for fixed-point
6495 if Is_Fixed_Point_Type (P_Type) then
6496 Fold_Uint (N, False_Value, True);
6498 -- Else yield proper floating-point result
6502 (N, UI_From_Int (Boolean'Pos (Machine_Rounds_On_Target)), True);
6509 -- Note: Machine_Size is identical to Object_Size
6511 when Attribute_Machine_Size => Machine_Size : declare
6512 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6515 if Known_Esize (P_TypeA) then
6516 Fold_Uint (N, Esize (P_TypeA), True);
6524 when Attribute_Mantissa =>
6526 -- Fixed-point mantissa
6528 if Is_Fixed_Point_Type (P_Type) then
6530 -- Compile time foldable case
6532 if Compile_Time_Known_Value (Type_Low_Bound (P_Type))
6534 Compile_Time_Known_Value (Type_High_Bound (P_Type))
6536 -- The calculation of the obsolete Ada 83 attribute Mantissa
6537 -- is annoying, because of AI00143, quoted here:
6539 -- !question 84-01-10
6541 -- Consider the model numbers for F:
6543 -- type F is delta 1.0 range -7.0 .. 8.0;
6545 -- The wording requires that F'MANTISSA be the SMALLEST
6546 -- integer number for which each bound of the specified
6547 -- range is either a model number or lies at most small
6548 -- distant from a model number. This means F'MANTISSA
6549 -- is required to be 3 since the range -7.0 .. 7.0 fits
6550 -- in 3 signed bits, and 8 is "at most" 1.0 from a model
6551 -- number, namely, 7. Is this analysis correct? Note that
6552 -- this implies the upper bound of the range is not
6553 -- represented as a model number.
6555 -- !response 84-03-17
6557 -- The analysis is correct. The upper and lower bounds for
6558 -- a fixed point type can lie outside the range of model
6569 LBound := Expr_Value_R (Type_Low_Bound (P_Type));
6570 UBound := Expr_Value_R (Type_High_Bound (P_Type));
6571 Bound := UR_Max (UR_Abs (LBound), UR_Abs (UBound));
6572 Max_Man := UR_Trunc (Bound / Small_Value (P_Type));
6574 -- If the Bound is exactly a model number, i.e. a multiple
6575 -- of Small, then we back it off by one to get the integer
6576 -- value that must be representable.
6578 if Small_Value (P_Type) * Max_Man = Bound then
6579 Max_Man := Max_Man - 1;
6582 -- Now find corresponding size = Mantissa value
6585 while 2 ** Siz < Max_Man loop
6589 Fold_Uint (N, Siz, True);
6593 -- The case of dynamic bounds cannot be evaluated at compile
6594 -- time. Instead we use a runtime routine (see Exp_Attr).
6599 -- Floating-point Mantissa
6602 Fold_Uint (N, Mantissa, True);
6609 when Attribute_Max => Max :
6611 if Is_Real_Type (P_Type) then
6613 (N, UR_Max (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6615 Fold_Uint (N, UI_Max (Expr_Value (E1), Expr_Value (E2)), Static);
6619 ----------------------------------
6620 -- Max_Alignment_For_Allocation --
6621 ----------------------------------
6623 -- Max_Alignment_For_Allocation is usually the Alignment. However,
6624 -- arrays are allocated with dope, so we need to take into account both
6625 -- the alignment of the array, which comes from the component alignment,
6626 -- and the alignment of the dope. Also, if the alignment is unknown, we
6627 -- use the max (it's OK to be pessimistic).
6629 when Attribute_Max_Alignment_For_Allocation =>
6631 A : Uint := UI_From_Int (Ttypes.Maximum_Alignment);
6633 if Known_Alignment (P_Type) and then
6634 (not Is_Array_Type (P_Type) or else Alignment (P_Type) > A)
6636 A := Alignment (P_Type);
6639 Fold_Uint (N, A, Static);
6642 ----------------------------------
6643 -- Max_Size_In_Storage_Elements --
6644 ----------------------------------
6646 -- Max_Size_In_Storage_Elements is simply the Size rounded up to a
6647 -- Storage_Unit boundary. We can fold any cases for which the size
6648 -- is known by the front end.
6650 when Attribute_Max_Size_In_Storage_Elements =>
6651 if Known_Esize (P_Type) then
6653 (Esize (P_Type) + System_Storage_Unit - 1) /
6654 System_Storage_Unit,
6658 --------------------
6659 -- Mechanism_Code --
6660 --------------------
6662 when Attribute_Mechanism_Code =>
6666 Mech : Mechanism_Type;
6670 Mech := Mechanism (P_Entity);
6673 Val := UI_To_Int (Expr_Value (E1));
6675 Formal := First_Formal (P_Entity);
6676 for J in 1 .. Val - 1 loop
6677 Next_Formal (Formal);
6679 Mech := Mechanism (Formal);
6683 Fold_Uint (N, UI_From_Int (Int (-Mech)), True);
6691 when Attribute_Min => Min :
6693 if Is_Real_Type (P_Type) then
6695 (N, UR_Min (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6698 (N, UI_Min (Expr_Value (E1), Expr_Value (E2)), Static);
6706 when Attribute_Mod =>
6708 (N, UI_Mod (Expr_Value (E1), Modulus (P_Base_Type)), Static);
6714 when Attribute_Model =>
6716 Eval_Fat.Model (P_Root_Type, Expr_Value_R (E1)), Static);
6722 when Attribute_Model_Emin =>
6723 Fold_Uint (N, Model_Emin_Value (P_Base_Type), Static);
6729 when Attribute_Model_Epsilon =>
6730 Fold_Ureal (N, Model_Epsilon_Value (P_Base_Type), Static);
6732 --------------------
6733 -- Model_Mantissa --
6734 --------------------
6736 when Attribute_Model_Mantissa =>
6737 Fold_Uint (N, Model_Mantissa_Value (P_Base_Type), Static);
6743 when Attribute_Model_Small =>
6744 Fold_Ureal (N, Model_Small_Value (P_Base_Type), Static);
6750 when Attribute_Modulus =>
6751 Fold_Uint (N, Modulus (P_Type), True);
6753 --------------------
6754 -- Null_Parameter --
6755 --------------------
6757 -- Cannot fold, we know the value sort of, but the whole point is
6758 -- that there is no way to talk about this imaginary value except
6759 -- by using the attribute, so we leave it the way it is.
6761 when Attribute_Null_Parameter =>
6768 -- The Object_Size attribute for a type returns the Esize of the
6769 -- type and can be folded if this value is known.
6771 when Attribute_Object_Size => Object_Size : declare
6772 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6775 if Known_Esize (P_TypeA) then
6776 Fold_Uint (N, Esize (P_TypeA), True);
6780 -------------------------
6781 -- Passed_By_Reference --
6782 -------------------------
6784 -- Scalar types are never passed by reference
6786 when Attribute_Passed_By_Reference =>
6787 Fold_Uint (N, False_Value, True);
6793 when Attribute_Pos =>
6794 Fold_Uint (N, Expr_Value (E1), True);
6800 when Attribute_Pred => Pred :
6802 -- Floating-point case
6804 if Is_Floating_Point_Type (P_Type) then
6806 Eval_Fat.Pred (P_Root_Type, Expr_Value_R (E1)), Static);
6810 elsif Is_Fixed_Point_Type (P_Type) then
6812 Expr_Value_R (E1) - Small_Value (P_Type), True);
6814 -- Modular integer case (wraps)
6816 elsif Is_Modular_Integer_Type (P_Type) then
6817 Fold_Uint (N, (Expr_Value (E1) - 1) mod Modulus (P_Type), Static);
6819 -- Other scalar cases
6822 pragma Assert (Is_Scalar_Type (P_Type));
6824 if Is_Enumeration_Type (P_Type)
6825 and then Expr_Value (E1) =
6826 Expr_Value (Type_Low_Bound (P_Base_Type))
6828 Apply_Compile_Time_Constraint_Error
6829 (N, "Pred of `&''First`",
6830 CE_Overflow_Check_Failed,
6832 Warn => not Static);
6838 Fold_Uint (N, Expr_Value (E1) - 1, Static);
6846 -- No processing required, because by this stage, Range has been
6847 -- replaced by First .. Last, so this branch can never be taken.
6849 when Attribute_Range =>
6850 raise Program_Error;
6856 when Attribute_Range_Length =>
6859 -- Can fold if both bounds are compile time known
6861 if Compile_Time_Known_Value (Hi_Bound)
6862 and then Compile_Time_Known_Value (Lo_Bound)
6866 (0, Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound) + 1),
6870 -- One more case is where Hi_Bound and Lo_Bound are compile-time
6871 -- comparable, and we can figure out the difference between them.
6874 Diff : aliased Uint;
6878 Compile_Time_Compare
6879 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
6882 Fold_Uint (N, Uint_1, False);
6885 Fold_Uint (N, Uint_0, False);
6888 if Diff /= No_Uint then
6889 Fold_Uint (N, Diff + 1, False);
6901 when Attribute_Ref =>
6902 Fold_Uint (N, Expr_Value (E1), True);
6908 when Attribute_Remainder => Remainder : declare
6909 X : constant Ureal := Expr_Value_R (E1);
6910 Y : constant Ureal := Expr_Value_R (E2);
6913 if UR_Is_Zero (Y) then
6914 Apply_Compile_Time_Constraint_Error
6915 (N, "division by zero in Remainder",
6916 CE_Overflow_Check_Failed,
6917 Warn => not Static);
6923 Fold_Ureal (N, Eval_Fat.Remainder (P_Root_Type, X, Y), Static);
6930 when Attribute_Round => Round :
6936 -- First we get the (exact result) in units of small
6938 Sr := Expr_Value_R (E1) / Small_Value (C_Type);
6940 -- Now round that exactly to an integer
6942 Si := UR_To_Uint (Sr);
6944 -- Finally the result is obtained by converting back to real
6946 Fold_Ureal (N, Si * Small_Value (C_Type), Static);
6953 when Attribute_Rounding =>
6955 Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static);
6961 when Attribute_Safe_Emax =>
6962 Fold_Uint (N, Safe_Emax_Value (P_Type), Static);
6968 when Attribute_Safe_First =>
6969 Fold_Ureal (N, Safe_First_Value (P_Type), Static);
6975 when Attribute_Safe_Large =>
6976 if Is_Fixed_Point_Type (P_Type) then
6978 (N, Expr_Value_R (Type_High_Bound (P_Base_Type)), Static);
6980 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
6987 when Attribute_Safe_Last =>
6988 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
6994 when Attribute_Safe_Small =>
6996 -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant
6997 -- for fixed-point, since is the same as Small, but we implement
6998 -- it for backwards compatibility.
7000 if Is_Fixed_Point_Type (P_Type) then
7001 Fold_Ureal (N, Small_Value (P_Type), Static);
7003 -- Ada 83 Safe_Small for floating-point cases
7006 Fold_Ureal (N, Model_Small_Value (P_Type), Static);
7013 when Attribute_Scale =>
7014 Fold_Uint (N, Scale_Value (P_Type), True);
7020 when Attribute_Scaling =>
7023 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
7029 when Attribute_Signed_Zeros =>
7031 (N, UI_From_Int (Boolean'Pos (Signed_Zeros_On_Target)), Static);
7037 -- Size attribute returns the RM size. All scalar types can be folded,
7038 -- as well as any types for which the size is known by the front end,
7039 -- including any type for which a size attribute is specified.
7041 when Attribute_Size | Attribute_VADS_Size => Size : declare
7042 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
7045 if RM_Size (P_TypeA) /= Uint_0 then
7049 if Id = Attribute_VADS_Size or else Use_VADS_Size then
7051 S : constant Node_Id := Size_Clause (P_TypeA);
7054 -- If a size clause applies, then use the size from it.
7055 -- This is one of the rare cases where we can use the
7056 -- Size_Clause field for a subtype when Has_Size_Clause
7057 -- is False. Consider:
7059 -- type x is range 1 .. 64;
7060 -- for x'size use 12;
7061 -- subtype y is x range 0 .. 3;
7063 -- Here y has a size clause inherited from x, but normally
7064 -- it does not apply, and y'size is 2. However, y'VADS_Size
7065 -- is indeed 12 and not 2.
7068 and then Is_OK_Static_Expression (Expression (S))
7070 Fold_Uint (N, Expr_Value (Expression (S)), True);
7072 -- If no size is specified, then we simply use the object
7073 -- size in the VADS_Size case (e.g. Natural'Size is equal
7074 -- to Integer'Size, not one less).
7077 Fold_Uint (N, Esize (P_TypeA), True);
7081 -- Normal case (Size) in which case we want the RM_Size
7086 Static and then Is_Discrete_Type (P_TypeA));
7095 when Attribute_Small =>
7097 -- The floating-point case is present only for Ada 83 compatibility.
7098 -- Note that strictly this is an illegal addition, since we are
7099 -- extending an Ada 95 defined attribute, but we anticipate an
7100 -- ARG ruling that will permit this.
7102 if Is_Floating_Point_Type (P_Type) then
7104 -- Ada 83 attribute is defined as (RM83 3.5.8)
7106 -- T'Small = 2.0**(-T'Emax - 1)
7110 -- T'Emax = 4 * T'Mantissa
7112 Fold_Ureal (N, Ureal_2 ** ((-(4 * Mantissa)) - 1), Static);
7114 -- Normal Ada 95 fixed-point case
7117 Fold_Ureal (N, Small_Value (P_Type), True);
7124 when Attribute_Stream_Size =>
7131 when Attribute_Succ => Succ :
7133 -- Floating-point case
7135 if Is_Floating_Point_Type (P_Type) then
7137 Eval_Fat.Succ (P_Root_Type, Expr_Value_R (E1)), Static);
7141 elsif Is_Fixed_Point_Type (P_Type) then
7143 Expr_Value_R (E1) + Small_Value (P_Type), Static);
7145 -- Modular integer case (wraps)
7147 elsif Is_Modular_Integer_Type (P_Type) then
7148 Fold_Uint (N, (Expr_Value (E1) + 1) mod Modulus (P_Type), Static);
7150 -- Other scalar cases
7153 pragma Assert (Is_Scalar_Type (P_Type));
7155 if Is_Enumeration_Type (P_Type)
7156 and then Expr_Value (E1) =
7157 Expr_Value (Type_High_Bound (P_Base_Type))
7159 Apply_Compile_Time_Constraint_Error
7160 (N, "Succ of `&''Last`",
7161 CE_Overflow_Check_Failed,
7163 Warn => not Static);
7168 Fold_Uint (N, Expr_Value (E1) + 1, Static);
7177 when Attribute_Truncation =>
7179 Eval_Fat.Truncation (P_Root_Type, Expr_Value_R (E1)), Static);
7185 when Attribute_Type_Class => Type_Class : declare
7186 Typ : constant Entity_Id := Underlying_Type (P_Base_Type);
7190 if Is_Descendent_Of_Address (Typ) then
7191 Id := RE_Type_Class_Address;
7193 elsif Is_Enumeration_Type (Typ) then
7194 Id := RE_Type_Class_Enumeration;
7196 elsif Is_Integer_Type (Typ) then
7197 Id := RE_Type_Class_Integer;
7199 elsif Is_Fixed_Point_Type (Typ) then
7200 Id := RE_Type_Class_Fixed_Point;
7202 elsif Is_Floating_Point_Type (Typ) then
7203 Id := RE_Type_Class_Floating_Point;
7205 elsif Is_Array_Type (Typ) then
7206 Id := RE_Type_Class_Array;
7208 elsif Is_Record_Type (Typ) then
7209 Id := RE_Type_Class_Record;
7211 elsif Is_Access_Type (Typ) then
7212 Id := RE_Type_Class_Access;
7214 elsif Is_Enumeration_Type (Typ) then
7215 Id := RE_Type_Class_Enumeration;
7217 elsif Is_Task_Type (Typ) then
7218 Id := RE_Type_Class_Task;
7220 -- We treat protected types like task types. It would make more
7221 -- sense to have another enumeration value, but after all the
7222 -- whole point of this feature is to be exactly DEC compatible,
7223 -- and changing the type Type_Class would not meet this requirement.
7225 elsif Is_Protected_Type (Typ) then
7226 Id := RE_Type_Class_Task;
7228 -- Not clear if there are any other possibilities, but if there
7229 -- are, then we will treat them as the address case.
7232 Id := RE_Type_Class_Address;
7235 Rewrite (N, New_Occurrence_Of (RTE (Id), Loc));
7238 -----------------------
7239 -- Unbiased_Rounding --
7240 -----------------------
7242 when Attribute_Unbiased_Rounding =>
7244 Eval_Fat.Unbiased_Rounding (P_Root_Type, Expr_Value_R (E1)),
7247 -------------------------
7248 -- Unconstrained_Array --
7249 -------------------------
7251 when Attribute_Unconstrained_Array => Unconstrained_Array : declare
7252 Typ : constant Entity_Id := Underlying_Type (P_Type);
7255 Rewrite (N, New_Occurrence_Of (
7257 Is_Array_Type (P_Type)
7258 and then not Is_Constrained (Typ)), Loc));
7260 -- Analyze and resolve as boolean, note that this attribute is
7261 -- a static attribute in GNAT.
7263 Analyze_And_Resolve (N, Standard_Boolean);
7265 end Unconstrained_Array;
7271 -- Processing is shared with Size
7277 when Attribute_Val => Val :
7279 if Expr_Value (E1) < Expr_Value (Type_Low_Bound (P_Base_Type))
7281 Expr_Value (E1) > Expr_Value (Type_High_Bound (P_Base_Type))
7283 Apply_Compile_Time_Constraint_Error
7284 (N, "Val expression out of range",
7285 CE_Range_Check_Failed,
7286 Warn => not Static);
7292 Fold_Uint (N, Expr_Value (E1), Static);
7300 -- The Value_Size attribute for a type returns the RM size of the
7301 -- type. This an always be folded for scalar types, and can also
7302 -- be folded for non-scalar types if the size is set.
7304 when Attribute_Value_Size => Value_Size : declare
7305 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
7307 if RM_Size (P_TypeA) /= Uint_0 then
7308 Fold_Uint (N, RM_Size (P_TypeA), True);
7316 -- Version can never be static
7318 when Attribute_Version =>
7325 -- Wide_Image is a scalar attribute, but is never static, because it
7326 -- is not a static function (having a non-scalar argument (RM 4.9(22))
7328 when Attribute_Wide_Image =>
7331 ---------------------
7332 -- Wide_Wide_Image --
7333 ---------------------
7335 -- Wide_Wide_Image is a scalar attribute but is never static, because it
7336 -- is not a static function (having a non-scalar argument (RM 4.9(22)).
7338 when Attribute_Wide_Wide_Image =>
7341 ---------------------
7342 -- Wide_Wide_Width --
7343 ---------------------
7345 -- Processing for Wide_Wide_Width is combined with Width
7351 -- Processing for Wide_Width is combined with Width
7357 -- This processing also handles the case of Wide_[Wide_]Width
7359 when Attribute_Width |
7360 Attribute_Wide_Width |
7361 Attribute_Wide_Wide_Width => Width :
7363 if Compile_Time_Known_Bounds (P_Type) then
7365 -- Floating-point types
7367 if Is_Floating_Point_Type (P_Type) then
7369 -- Width is zero for a null range (RM 3.5 (38))
7371 if Expr_Value_R (Type_High_Bound (P_Type)) <
7372 Expr_Value_R (Type_Low_Bound (P_Type))
7374 Fold_Uint (N, Uint_0, True);
7377 -- For floating-point, we have +N.dddE+nnn where length
7378 -- of ddd is determined by type'Digits - 1, but is one
7379 -- if Digits is one (RM 3.5 (33)).
7381 -- nnn is set to 2 for Short_Float and Float (32 bit
7382 -- floats), and 3 for Long_Float and Long_Long_Float.
7383 -- For machines where Long_Long_Float is the IEEE
7384 -- extended precision type, the exponent takes 4 digits.
7388 Int'Max (2, UI_To_Int (Digits_Value (P_Type)));
7391 if Esize (P_Type) <= 32 then
7393 elsif Esize (P_Type) = 64 then
7399 Fold_Uint (N, UI_From_Int (Len), True);
7403 -- Fixed-point types
7405 elsif Is_Fixed_Point_Type (P_Type) then
7407 -- Width is zero for a null range (RM 3.5 (38))
7409 if Expr_Value (Type_High_Bound (P_Type)) <
7410 Expr_Value (Type_Low_Bound (P_Type))
7412 Fold_Uint (N, Uint_0, True);
7414 -- The non-null case depends on the specific real type
7417 -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34))
7420 (N, UI_From_Int (Fore_Value + 1) + Aft_Value (P_Type),
7428 R : constant Entity_Id := Root_Type (P_Type);
7429 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
7430 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
7443 -- Width for types derived from Standard.Character
7444 -- and Standard.Wide_[Wide_]Character.
7446 elsif Is_Standard_Character_Type (P_Type) then
7449 -- Set W larger if needed
7451 for J in UI_To_Int (Lo) .. UI_To_Int (Hi) loop
7453 -- All wide characters look like Hex_hhhhhhhh
7457 -- No need to compute this more than once!
7462 C := Character'Val (J);
7464 -- Test for all cases where Character'Image
7465 -- yields an image that is longer than three
7466 -- characters. First the cases of Reserved_xxx
7467 -- names (length = 12).
7470 when Reserved_128 | Reserved_129 |
7471 Reserved_132 | Reserved_153
7474 when BS | HT | LF | VT | FF | CR |
7475 SO | SI | EM | FS | GS | RS |
7476 US | RI | MW | ST | PM
7479 when NUL | SOH | STX | ETX | EOT |
7480 ENQ | ACK | BEL | DLE | DC1 |
7481 DC2 | DC3 | DC4 | NAK | SYN |
7482 ETB | CAN | SUB | ESC | DEL |
7483 BPH | NBH | NEL | SSA | ESA |
7484 HTS | HTJ | VTS | PLD | PLU |
7485 SS2 | SS3 | DCS | PU1 | PU2 |
7486 STS | CCH | SPA | EPA | SOS |
7487 SCI | CSI | OSC | APC
7490 when Space .. Tilde |
7491 No_Break_Space .. LC_Y_Diaeresis
7493 -- Special case of soft hyphen in Ada 2005
7495 if C = Character'Val (16#AD#)
7496 and then Ada_Version >= Ada_2005
7504 W := Int'Max (W, Wt);
7508 -- Width for types derived from Standard.Boolean
7510 elsif R = Standard_Boolean then
7517 -- Width for integer types
7519 elsif Is_Integer_Type (P_Type) then
7520 T := UI_Max (abs Lo, abs Hi);
7528 -- Only remaining possibility is user declared enum type
7531 pragma Assert (Is_Enumeration_Type (P_Type));
7534 L := First_Literal (P_Type);
7536 while Present (L) loop
7538 -- Only pay attention to in range characters
7540 if Lo <= Enumeration_Pos (L)
7541 and then Enumeration_Pos (L) <= Hi
7543 -- For Width case, use decoded name
7545 if Id = Attribute_Width then
7546 Get_Decoded_Name_String (Chars (L));
7547 Wt := Nat (Name_Len);
7549 -- For Wide_[Wide_]Width, use encoded name, and
7550 -- then adjust for the encoding.
7553 Get_Name_String (Chars (L));
7555 -- Character literals are always of length 3
7557 if Name_Buffer (1) = 'Q' then
7560 -- Otherwise loop to adjust for upper/wide chars
7563 Wt := Nat (Name_Len);
7565 for J in 1 .. Name_Len loop
7566 if Name_Buffer (J) = 'U' then
7568 elsif Name_Buffer (J) = 'W' then
7575 W := Int'Max (W, Wt);
7582 Fold_Uint (N, UI_From_Int (W), True);
7588 -- The following attributes denote functions that cannot be folded
7590 when Attribute_From_Any |
7592 Attribute_TypeCode =>
7595 -- The following attributes can never be folded, and furthermore we
7596 -- should not even have entered the case statement for any of these.
7597 -- Note that in some cases, the values have already been folded as
7598 -- a result of the processing in Analyze_Attribute.
7600 when Attribute_Abort_Signal |
7603 Attribute_Address_Size |
7604 Attribute_Asm_Input |
7605 Attribute_Asm_Output |
7607 Attribute_Bit_Order |
7608 Attribute_Bit_Position |
7609 Attribute_Callable |
7612 Attribute_Code_Address |
7613 Attribute_Compiler_Version |
7615 Attribute_Default_Bit_Order |
7616 Attribute_Elaborated |
7617 Attribute_Elab_Body |
7618 Attribute_Elab_Spec |
7620 Attribute_External_Tag |
7621 Attribute_Fast_Math |
7622 Attribute_First_Bit |
7624 Attribute_Last_Bit |
7625 Attribute_Maximum_Alignment |
7628 Attribute_Partition_ID |
7629 Attribute_Pool_Address |
7630 Attribute_Position |
7631 Attribute_Priority |
7634 Attribute_Storage_Pool |
7635 Attribute_Storage_Size |
7636 Attribute_Storage_Unit |
7637 Attribute_Stub_Type |
7639 Attribute_Target_Name |
7640 Attribute_Terminated |
7641 Attribute_To_Address |
7642 Attribute_Type_Key |
7643 Attribute_UET_Address |
7644 Attribute_Unchecked_Access |
7645 Attribute_Universal_Literal_String |
7646 Attribute_Unrestricted_Access |
7649 Attribute_Wchar_T_Size |
7650 Attribute_Wide_Value |
7651 Attribute_Wide_Wide_Value |
7652 Attribute_Word_Size |
7655 raise Program_Error;
7658 -- At the end of the case, one more check. If we did a static evaluation
7659 -- so that the result is now a literal, then set Is_Static_Expression
7660 -- in the constant only if the prefix type is a static subtype. For
7661 -- non-static subtypes, the folding is still OK, but not static.
7663 -- An exception is the GNAT attribute Constrained_Array which is
7664 -- defined to be a static attribute in all cases.
7666 if Nkind_In (N, N_Integer_Literal,
7668 N_Character_Literal,
7670 or else (Is_Entity_Name (N)
7671 and then Ekind (Entity (N)) = E_Enumeration_Literal)
7673 Set_Is_Static_Expression (N, Static);
7675 -- If this is still an attribute reference, then it has not been folded
7676 -- and that means that its expressions are in a non-static context.
7678 elsif Nkind (N) = N_Attribute_Reference then
7681 -- Note: the else case not covered here are odd cases where the
7682 -- processing has transformed the attribute into something other
7683 -- than a constant. Nothing more to do in such cases.
7690 ------------------------------
7691 -- Is_Anonymous_Tagged_Base --
7692 ------------------------------
7694 function Is_Anonymous_Tagged_Base
7701 Anon = Current_Scope
7702 and then Is_Itype (Anon)
7703 and then Associated_Node_For_Itype (Anon) = Parent (Typ);
7704 end Is_Anonymous_Tagged_Base;
7706 --------------------------------
7707 -- Name_Implies_Lvalue_Prefix --
7708 --------------------------------
7710 function Name_Implies_Lvalue_Prefix (Nam : Name_Id) return Boolean is
7711 pragma Assert (Is_Attribute_Name (Nam));
7713 return Attribute_Name_Implies_Lvalue_Prefix (Get_Attribute_Id (Nam));
7714 end Name_Implies_Lvalue_Prefix;
7716 -----------------------
7717 -- Resolve_Attribute --
7718 -----------------------
7720 procedure Resolve_Attribute (N : Node_Id; Typ : Entity_Id) is
7721 Loc : constant Source_Ptr := Sloc (N);
7722 P : constant Node_Id := Prefix (N);
7723 Aname : constant Name_Id := Attribute_Name (N);
7724 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
7725 Btyp : constant Entity_Id := Base_Type (Typ);
7726 Des_Btyp : Entity_Id;
7727 Index : Interp_Index;
7729 Nom_Subt : Entity_Id;
7731 procedure Accessibility_Message;
7732 -- Error, or warning within an instance, if the static accessibility
7733 -- rules of 3.10.2 are violated.
7735 ---------------------------
7736 -- Accessibility_Message --
7737 ---------------------------
7739 procedure Accessibility_Message is
7740 Indic : Node_Id := Parent (Parent (N));
7743 -- In an instance, this is a runtime check, but one we
7744 -- know will fail, so generate an appropriate warning.
7746 if In_Instance_Body then
7747 Error_Msg_F ("?non-local pointer cannot point to local object", P);
7749 ("\?Program_Error will be raised at run time", P);
7751 Make_Raise_Program_Error (Loc,
7752 Reason => PE_Accessibility_Check_Failed));
7757 Error_Msg_F ("non-local pointer cannot point to local object", P);
7759 -- Check for case where we have a missing access definition
7761 if Is_Record_Type (Current_Scope)
7763 Nkind_In (Parent (N), N_Discriminant_Association,
7764 N_Index_Or_Discriminant_Constraint)
7766 Indic := Parent (Parent (N));
7767 while Present (Indic)
7768 and then Nkind (Indic) /= N_Subtype_Indication
7770 Indic := Parent (Indic);
7773 if Present (Indic) then
7775 ("\use an access definition for" &
7776 " the access discriminant of&",
7777 N, Entity (Subtype_Mark (Indic)));
7781 end Accessibility_Message;
7783 -- Start of processing for Resolve_Attribute
7786 -- If error during analysis, no point in continuing, except for array
7787 -- types, where we get better recovery by using unconstrained indexes
7788 -- than nothing at all (see Check_Array_Type).
7791 and then Attr_Id /= Attribute_First
7792 and then Attr_Id /= Attribute_Last
7793 and then Attr_Id /= Attribute_Length
7794 and then Attr_Id /= Attribute_Range
7799 -- If attribute was universal type, reset to actual type
7801 if Etype (N) = Universal_Integer
7802 or else Etype (N) = Universal_Real
7807 -- Remaining processing depends on attribute
7815 -- For access attributes, if the prefix denotes an entity, it is
7816 -- interpreted as a name, never as a call. It may be overloaded,
7817 -- in which case resolution uses the profile of the context type.
7818 -- Otherwise prefix must be resolved.
7820 when Attribute_Access
7821 | Attribute_Unchecked_Access
7822 | Attribute_Unrestricted_Access =>
7826 if Is_Variable (P) then
7827 Note_Possible_Modification (P, Sure => False);
7830 -- The following comes from a query by Adam Beneschan, concerning
7831 -- improper use of universal_access in equality tests involving
7832 -- anonymous access types. Another good reason for 'Ref, but
7833 -- for now disable the test, which breaks several filed tests.
7835 if Ekind (Typ) = E_Anonymous_Access_Type
7836 and then Nkind_In (Parent (N), N_Op_Eq, N_Op_Ne)
7839 Error_Msg_N ("need unique type to resolve 'Access", N);
7840 Error_Msg_N ("\qualify attribute with some access type", N);
7843 if Is_Entity_Name (P) then
7844 if Is_Overloaded (P) then
7845 Get_First_Interp (P, Index, It);
7846 while Present (It.Nam) loop
7847 if Type_Conformant (Designated_Type (Typ), It.Nam) then
7848 Set_Entity (P, It.Nam);
7850 -- The prefix is definitely NOT overloaded anymore at
7851 -- this point, so we reset the Is_Overloaded flag to
7852 -- avoid any confusion when reanalyzing the node.
7854 Set_Is_Overloaded (P, False);
7855 Set_Is_Overloaded (N, False);
7856 Generate_Reference (Entity (P), P);
7860 Get_Next_Interp (Index, It);
7863 -- If Prefix is a subprogram name, it is frozen by this
7866 -- If it is a type, there is nothing to resolve.
7867 -- If it is an object, complete its resolution.
7869 elsif Is_Overloadable (Entity (P)) then
7871 -- Avoid insertion of freeze actions in spec expression mode
7873 if not In_Spec_Expression then
7874 Freeze_Before (N, Entity (P));
7877 elsif Is_Type (Entity (P)) then
7883 Error_Msg_Name_1 := Aname;
7885 if not Is_Entity_Name (P) then
7888 elsif Is_Overloadable (Entity (P))
7889 and then Is_Abstract_Subprogram (Entity (P))
7891 Error_Msg_F ("prefix of % attribute cannot be abstract", P);
7892 Set_Etype (N, Any_Type);
7894 elsif Convention (Entity (P)) = Convention_Intrinsic then
7895 if Ekind (Entity (P)) = E_Enumeration_Literal then
7897 ("prefix of % attribute cannot be enumeration literal",
7901 ("prefix of % attribute cannot be intrinsic", P);
7904 Set_Etype (N, Any_Type);
7907 -- Assignments, return statements, components of aggregates,
7908 -- generic instantiations will require convention checks if
7909 -- the type is an access to subprogram. Given that there will
7910 -- also be accessibility checks on those, this is where the
7911 -- checks can eventually be centralized ???
7913 if Ekind_In (Btyp, E_Access_Subprogram_Type,
7914 E_Anonymous_Access_Subprogram_Type,
7915 E_Access_Protected_Subprogram_Type,
7916 E_Anonymous_Access_Protected_Subprogram_Type)
7918 -- Deal with convention mismatch
7920 if Convention (Designated_Type (Btyp)) /=
7921 Convention (Entity (P))
7924 ("subprogram & has wrong convention", P, Entity (P));
7926 ("\does not match convention of access type &",
7929 if not Has_Convention_Pragma (Btyp) then
7931 ("\probable missing pragma Convention for &",
7936 Check_Subtype_Conformant
7937 (New_Id => Entity (P),
7938 Old_Id => Designated_Type (Btyp),
7942 if Attr_Id = Attribute_Unchecked_Access then
7943 Error_Msg_Name_1 := Aname;
7945 ("attribute% cannot be applied to a subprogram", P);
7947 elsif Aname = Name_Unrestricted_Access then
7948 null; -- Nothing to check
7950 -- Check the static accessibility rule of 3.10.2(32).
7951 -- This rule also applies within the private part of an
7952 -- instantiation. This rule does not apply to anonymous
7953 -- access-to-subprogram types in access parameters.
7955 elsif Attr_Id = Attribute_Access
7956 and then not In_Instance_Body
7958 (Ekind (Btyp) = E_Access_Subprogram_Type
7959 or else Is_Local_Anonymous_Access (Btyp))
7961 and then Subprogram_Access_Level (Entity (P)) >
7962 Type_Access_Level (Btyp)
7965 ("subprogram must not be deeper than access type", P);
7967 -- Check the restriction of 3.10.2(32) that disallows the
7968 -- access attribute within a generic body when the ultimate
7969 -- ancestor of the type of the attribute is declared outside
7970 -- of the generic unit and the subprogram is declared within
7971 -- that generic unit. This includes any such attribute that
7972 -- occurs within the body of a generic unit that is a child
7973 -- of the generic unit where the subprogram is declared.
7975 -- The rule also prohibits applying the attribute when the
7976 -- access type is a generic formal access type (since the
7977 -- level of the actual type is not known). This restriction
7978 -- does not apply when the attribute type is an anonymous
7979 -- access-to-subprogram type. Note that this check was
7980 -- revised by AI-229, because the originally Ada 95 rule
7981 -- was too lax. The original rule only applied when the
7982 -- subprogram was declared within the body of the generic,
7983 -- which allowed the possibility of dangling references).
7984 -- The rule was also too strict in some case, in that it
7985 -- didn't permit the access to be declared in the generic
7986 -- spec, whereas the revised rule does (as long as it's not
7989 -- There are a couple of subtleties of the test for applying
7990 -- the check that are worth noting. First, we only apply it
7991 -- when the levels of the subprogram and access type are the
7992 -- same (the case where the subprogram is statically deeper
7993 -- was applied above, and the case where the type is deeper
7994 -- is always safe). Second, we want the check to apply
7995 -- within nested generic bodies and generic child unit
7996 -- bodies, but not to apply to an attribute that appears in
7997 -- the generic unit's specification. This is done by testing
7998 -- that the attribute's innermost enclosing generic body is
7999 -- not the same as the innermost generic body enclosing the
8000 -- generic unit where the subprogram is declared (we don't
8001 -- want the check to apply when the access attribute is in
8002 -- the spec and there's some other generic body enclosing
8003 -- generic). Finally, there's no point applying the check
8004 -- when within an instance, because any violations will have
8005 -- been caught by the compilation of the generic unit.
8007 -- Note that we relax this check in CodePeer mode for
8008 -- compatibility with legacy code, since CodePeer is an
8009 -- Ada source code analyzer, not a strict compiler.
8010 -- ??? Note that a better approach would be to have a
8011 -- separate switch to relax this rule, and enable this
8012 -- switch in CodePeer mode.
8014 elsif Attr_Id = Attribute_Access
8015 and then not CodePeer_Mode
8016 and then not In_Instance
8017 and then Present (Enclosing_Generic_Unit (Entity (P)))
8018 and then Present (Enclosing_Generic_Body (N))
8019 and then Enclosing_Generic_Body (N) /=
8020 Enclosing_Generic_Body
8021 (Enclosing_Generic_Unit (Entity (P)))
8022 and then Subprogram_Access_Level (Entity (P)) =
8023 Type_Access_Level (Btyp)
8024 and then Ekind (Btyp) /=
8025 E_Anonymous_Access_Subprogram_Type
8026 and then Ekind (Btyp) /=
8027 E_Anonymous_Access_Protected_Subprogram_Type
8029 -- The attribute type's ultimate ancestor must be
8030 -- declared within the same generic unit as the
8031 -- subprogram is declared. The error message is
8032 -- specialized to say "ancestor" for the case where the
8033 -- access type is not its own ancestor, since saying
8034 -- simply "access type" would be very confusing.
8036 if Enclosing_Generic_Unit (Entity (P)) /=
8037 Enclosing_Generic_Unit (Root_Type (Btyp))
8040 ("''Access attribute not allowed in generic body",
8043 if Root_Type (Btyp) = Btyp then
8046 "access type & is declared outside " &
8047 "generic unit (RM 3.10.2(32))", N, Btyp);
8050 ("\because ancestor of " &
8051 "access type & is declared outside " &
8052 "generic unit (RM 3.10.2(32))", N, Btyp);
8056 ("\move ''Access to private part, or " &
8057 "(Ada 2005) use anonymous access type instead of &",
8060 -- If the ultimate ancestor of the attribute's type is
8061 -- a formal type, then the attribute is illegal because
8062 -- the actual type might be declared at a higher level.
8063 -- The error message is specialized to say "ancestor"
8064 -- for the case where the access type is not its own
8065 -- ancestor, since saying simply "access type" would be
8068 elsif Is_Generic_Type (Root_Type (Btyp)) then
8069 if Root_Type (Btyp) = Btyp then
8071 ("access type must not be a generic formal type",
8075 ("ancestor access type must not be a generic " &
8082 -- If this is a renaming, an inherited operation, or a
8083 -- subprogram instance, use the original entity. This may make
8084 -- the node type-inconsistent, so this transformation can only
8085 -- be done if the node will not be reanalyzed. In particular,
8086 -- if it is within a default expression, the transformation
8087 -- must be delayed until the default subprogram is created for
8088 -- it, when the enclosing subprogram is frozen.
8090 if Is_Entity_Name (P)
8091 and then Is_Overloadable (Entity (P))
8092 and then Present (Alias (Entity (P)))
8093 and then Expander_Active
8096 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
8099 elsif Nkind (P) = N_Selected_Component
8100 and then Is_Overloadable (Entity (Selector_Name (P)))
8102 -- Protected operation. If operation is overloaded, must
8103 -- disambiguate. Prefix that denotes protected object itself
8104 -- is resolved with its own type.
8106 if Attr_Id = Attribute_Unchecked_Access then
8107 Error_Msg_Name_1 := Aname;
8109 ("attribute% cannot be applied to protected operation", P);
8112 Resolve (Prefix (P));
8113 Generate_Reference (Entity (Selector_Name (P)), P);
8115 elsif Is_Overloaded (P) then
8117 -- Use the designated type of the context to disambiguate
8118 -- Note that this was not strictly conformant to Ada 95,
8119 -- but was the implementation adopted by most Ada 95 compilers.
8120 -- The use of the context type to resolve an Access attribute
8121 -- reference is now mandated in AI-235 for Ada 2005.
8124 Index : Interp_Index;
8128 Get_First_Interp (P, Index, It);
8129 while Present (It.Typ) loop
8130 if Covers (Designated_Type (Typ), It.Typ) then
8131 Resolve (P, It.Typ);
8135 Get_Next_Interp (Index, It);
8142 -- X'Access is illegal if X denotes a constant and the access type
8143 -- is access-to-variable. Same for 'Unchecked_Access. The rule
8144 -- does not apply to 'Unrestricted_Access. If the reference is a
8145 -- default-initialized aggregate component for a self-referential
8146 -- type the reference is legal.
8148 if not (Ekind (Btyp) = E_Access_Subprogram_Type
8149 or else Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type
8150 or else (Is_Record_Type (Btyp)
8152 Present (Corresponding_Remote_Type (Btyp)))
8153 or else Ekind (Btyp) = E_Access_Protected_Subprogram_Type
8154 or else Ekind (Btyp)
8155 = E_Anonymous_Access_Protected_Subprogram_Type
8156 or else Is_Access_Constant (Btyp)
8157 or else Is_Variable (P)
8158 or else Attr_Id = Attribute_Unrestricted_Access)
8160 if Is_Entity_Name (P)
8161 and then Is_Type (Entity (P))
8163 -- Legality of a self-reference through an access
8164 -- attribute has been verified in Analyze_Access_Attribute.
8168 elsif Comes_From_Source (N) then
8169 Error_Msg_F ("access-to-variable designates constant", P);
8173 Des_Btyp := Designated_Type (Btyp);
8175 if Ada_Version >= Ada_2005
8176 and then Is_Incomplete_Type (Des_Btyp)
8178 -- Ada 2005 (AI-412): If the (sub)type is a limited view of an
8179 -- imported entity, and the non-limited view is visible, make
8180 -- use of it. If it is an incomplete subtype, use the base type
8183 if From_With_Type (Des_Btyp)
8184 and then Present (Non_Limited_View (Des_Btyp))
8186 Des_Btyp := Non_Limited_View (Des_Btyp);
8188 elsif Ekind (Des_Btyp) = E_Incomplete_Subtype then
8189 Des_Btyp := Etype (Des_Btyp);
8193 if (Attr_Id = Attribute_Access
8195 Attr_Id = Attribute_Unchecked_Access)
8196 and then (Ekind (Btyp) = E_General_Access_Type
8197 or else Ekind (Btyp) = E_Anonymous_Access_Type)
8199 -- Ada 2005 (AI-230): Check the accessibility of anonymous
8200 -- access types for stand-alone objects, record and array
8201 -- components, and return objects. For a component definition
8202 -- the level is the same of the enclosing composite type.
8204 if Ada_Version >= Ada_2005
8205 and then Is_Local_Anonymous_Access (Btyp)
8206 and then Object_Access_Level (P) > Type_Access_Level (Btyp)
8207 and then Attr_Id = Attribute_Access
8209 -- In an instance, this is a runtime check, but one we
8210 -- know will fail, so generate an appropriate warning.
8212 if In_Instance_Body then
8214 ("?non-local pointer cannot point to local object", P);
8216 ("\?Program_Error will be raised at run time", P);
8218 Make_Raise_Program_Error (Loc,
8219 Reason => PE_Accessibility_Check_Failed));
8224 ("non-local pointer cannot point to local object", P);
8228 if Is_Dependent_Component_Of_Mutable_Object (P) then
8230 ("illegal attribute for discriminant-dependent component",
8234 -- Check static matching rule of 3.10.2(27). Nominal subtype
8235 -- of the prefix must statically match the designated type.
8237 Nom_Subt := Etype (P);
8239 if Is_Constr_Subt_For_U_Nominal (Nom_Subt) then
8240 Nom_Subt := Base_Type (Nom_Subt);
8243 if Is_Tagged_Type (Designated_Type (Typ)) then
8245 -- If the attribute is in the context of an access
8246 -- parameter, then the prefix is allowed to be of the
8247 -- class-wide type (by AI-127).
8249 if Ekind (Typ) = E_Anonymous_Access_Type then
8250 if not Covers (Designated_Type (Typ), Nom_Subt)
8251 and then not Covers (Nom_Subt, Designated_Type (Typ))
8257 Desig := Designated_Type (Typ);
8259 if Is_Class_Wide_Type (Desig) then
8260 Desig := Etype (Desig);
8263 if Is_Anonymous_Tagged_Base (Nom_Subt, Desig) then
8268 ("type of prefix: & not compatible",
8271 ("\with &, the expected designated type",
8272 P, Designated_Type (Typ));
8277 elsif not Covers (Designated_Type (Typ), Nom_Subt)
8279 (not Is_Class_Wide_Type (Designated_Type (Typ))
8280 and then Is_Class_Wide_Type (Nom_Subt))
8283 ("type of prefix: & is not covered", P, Nom_Subt);
8285 ("\by &, the expected designated type" &
8286 " (RM 3.10.2 (27))", P, Designated_Type (Typ));
8289 if Is_Class_Wide_Type (Designated_Type (Typ))
8290 and then Has_Discriminants (Etype (Designated_Type (Typ)))
8291 and then Is_Constrained (Etype (Designated_Type (Typ)))
8292 and then Designated_Type (Typ) /= Nom_Subt
8294 Apply_Discriminant_Check
8295 (N, Etype (Designated_Type (Typ)));
8298 -- Ada 2005 (AI-363): Require static matching when designated
8299 -- type has discriminants and a constrained partial view, since
8300 -- in general objects of such types are mutable, so we can't
8301 -- allow the access value to designate a constrained object
8302 -- (because access values must be assumed to designate mutable
8303 -- objects when designated type does not impose a constraint).
8305 elsif Subtypes_Statically_Match (Des_Btyp, Nom_Subt) then
8308 elsif Has_Discriminants (Designated_Type (Typ))
8309 and then not Is_Constrained (Des_Btyp)
8311 (Ada_Version < Ada_2005
8313 not Has_Constrained_Partial_View
8314 (Designated_Type (Base_Type (Typ))))
8320 ("object subtype must statically match "
8321 & "designated subtype", P);
8323 if Is_Entity_Name (P)
8324 and then Is_Array_Type (Designated_Type (Typ))
8327 D : constant Node_Id := Declaration_Node (Entity (P));
8330 Error_Msg_N ("aliased object has explicit bounds?",
8332 Error_Msg_N ("\declare without bounds"
8333 & " (and with explicit initialization)?", D);
8334 Error_Msg_N ("\for use with unconstrained access?", D);
8339 -- Check the static accessibility rule of 3.10.2(28).
8340 -- Note that this check is not performed for the
8341 -- case of an anonymous access type, since the access
8342 -- attribute is always legal in such a context.
8344 if Attr_Id /= Attribute_Unchecked_Access
8345 and then Object_Access_Level (P) > Type_Access_Level (Btyp)
8346 and then Ekind (Btyp) = E_General_Access_Type
8348 Accessibility_Message;
8353 if Ekind_In (Btyp, E_Access_Protected_Subprogram_Type,
8354 E_Anonymous_Access_Protected_Subprogram_Type)
8356 if Is_Entity_Name (P)
8357 and then not Is_Protected_Type (Scope (Entity (P)))
8359 Error_Msg_F ("context requires a protected subprogram", P);
8361 -- Check accessibility of protected object against that of the
8362 -- access type, but only on user code, because the expander
8363 -- creates access references for handlers. If the context is an
8364 -- anonymous_access_to_protected, there are no accessibility
8365 -- checks either. Omit check entirely for Unrestricted_Access.
8367 elsif Object_Access_Level (P) > Type_Access_Level (Btyp)
8368 and then Comes_From_Source (N)
8369 and then Ekind (Btyp) = E_Access_Protected_Subprogram_Type
8370 and then Attr_Id /= Attribute_Unrestricted_Access
8372 Accessibility_Message;
8376 elsif Ekind_In (Btyp, E_Access_Subprogram_Type,
8377 E_Anonymous_Access_Subprogram_Type)
8378 and then Ekind (Etype (N)) = E_Access_Protected_Subprogram_Type
8380 Error_Msg_F ("context requires a non-protected subprogram", P);
8383 -- The context cannot be a pool-specific type, but this is a
8384 -- legality rule, not a resolution rule, so it must be checked
8385 -- separately, after possibly disambiguation (see AI-245).
8387 if Ekind (Btyp) = E_Access_Type
8388 and then Attr_Id /= Attribute_Unrestricted_Access
8390 Wrong_Type (N, Typ);
8393 -- The context may be a constrained access type (however ill-
8394 -- advised such subtypes might be) so in order to generate a
8395 -- constraint check when needed set the type of the attribute
8396 -- reference to the base type of the context.
8398 Set_Etype (N, Btyp);
8400 -- Check for incorrect atomic/volatile reference (RM C.6(12))
8402 if Attr_Id /= Attribute_Unrestricted_Access then
8403 if Is_Atomic_Object (P)
8404 and then not Is_Atomic (Designated_Type (Typ))
8407 ("access to atomic object cannot yield access-to-" &
8408 "non-atomic type", P);
8410 elsif Is_Volatile_Object (P)
8411 and then not Is_Volatile (Designated_Type (Typ))
8414 ("access to volatile object cannot yield access-to-" &
8415 "non-volatile type", P);
8419 if Is_Entity_Name (P) then
8420 Set_Address_Taken (Entity (P));
8422 end Access_Attribute;
8428 -- Deal with resolving the type for Address attribute, overloading
8429 -- is not permitted here, since there is no context to resolve it.
8431 when Attribute_Address | Attribute_Code_Address =>
8432 Address_Attribute : begin
8434 -- To be safe, assume that if the address of a variable is taken,
8435 -- it may be modified via this address, so note modification.
8437 if Is_Variable (P) then
8438 Note_Possible_Modification (P, Sure => False);
8441 if Nkind (P) in N_Subexpr
8442 and then Is_Overloaded (P)
8444 Get_First_Interp (P, Index, It);
8445 Get_Next_Interp (Index, It);
8447 if Present (It.Nam) then
8448 Error_Msg_Name_1 := Aname;
8450 ("prefix of % attribute cannot be overloaded", P);
8454 if not Is_Entity_Name (P)
8455 or else not Is_Overloadable (Entity (P))
8457 if not Is_Task_Type (Etype (P))
8458 or else Nkind (P) = N_Explicit_Dereference
8464 -- If this is the name of a derived subprogram, or that of a
8465 -- generic actual, the address is that of the original entity.
8467 if Is_Entity_Name (P)
8468 and then Is_Overloadable (Entity (P))
8469 and then Present (Alias (Entity (P)))
8472 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
8475 if Is_Entity_Name (P) then
8476 Set_Address_Taken (Entity (P));
8479 if Nkind (P) = N_Slice then
8481 -- Arr (X .. Y)'address is identical to Arr (X)'address,
8482 -- even if the array is packed and the slice itself is not
8483 -- addressable. Transform the prefix into an indexed component.
8485 -- Note that the transformation is safe only if we know that
8486 -- the slice is non-null. That is because a null slice can have
8487 -- an out of bounds index value.
8489 -- Right now, gigi blows up if given 'Address on a slice as a
8490 -- result of some incorrect freeze nodes generated by the front
8491 -- end, and this covers up that bug in one case, but the bug is
8492 -- likely still there in the cases not handled by this code ???
8494 -- It's not clear what 'Address *should* return for a null
8495 -- slice with out of bounds indexes, this might be worth an ARG
8498 -- One approach would be to do a length check unconditionally,
8499 -- and then do the transformation below unconditionally, but
8500 -- analyze with checks off, avoiding the problem of the out of
8501 -- bounds index. This approach would interpret the address of
8502 -- an out of bounds null slice as being the address where the
8503 -- array element would be if there was one, which is probably
8504 -- as reasonable an interpretation as any ???
8507 Loc : constant Source_Ptr := Sloc (P);
8508 D : constant Node_Id := Discrete_Range (P);
8512 if Is_Entity_Name (D)
8515 (Type_Low_Bound (Entity (D)),
8516 Type_High_Bound (Entity (D)))
8519 Make_Attribute_Reference (Loc,
8520 Prefix => (New_Occurrence_Of (Entity (D), Loc)),
8521 Attribute_Name => Name_First);
8523 elsif Nkind (D) = N_Range
8524 and then Not_Null_Range (Low_Bound (D), High_Bound (D))
8526 Lo := Low_Bound (D);
8532 if Present (Lo) then
8534 Make_Indexed_Component (Loc,
8535 Prefix => Relocate_Node (Prefix (P)),
8536 Expressions => New_List (Lo)));
8538 Analyze_And_Resolve (P);
8542 end Address_Attribute;
8548 -- Prefix of the AST_Entry attribute is an entry name which must
8549 -- not be resolved, since this is definitely not an entry call.
8551 when Attribute_AST_Entry =>
8558 -- Prefix of Body_Version attribute can be a subprogram name which
8559 -- must not be resolved, since this is not a call.
8561 when Attribute_Body_Version =>
8568 -- Prefix of Caller attribute is an entry name which must not
8569 -- be resolved, since this is definitely not an entry call.
8571 when Attribute_Caller =>
8578 -- Shares processing with Address attribute
8584 -- If the prefix of the Count attribute is an entry name it must not
8585 -- be resolved, since this is definitely not an entry call. However,
8586 -- if it is an element of an entry family, the index itself may
8587 -- have to be resolved because it can be a general expression.
8589 when Attribute_Count =>
8590 if Nkind (P) = N_Indexed_Component
8591 and then Is_Entity_Name (Prefix (P))
8594 Indx : constant Node_Id := First (Expressions (P));
8595 Fam : constant Entity_Id := Entity (Prefix (P));
8597 Resolve (Indx, Entry_Index_Type (Fam));
8598 Apply_Range_Check (Indx, Entry_Index_Type (Fam));
8606 -- Prefix of the Elaborated attribute is a subprogram name which
8607 -- must not be resolved, since this is definitely not a call. Note
8608 -- that it is a library unit, so it cannot be overloaded here.
8610 when Attribute_Elaborated =>
8617 -- Prefix of Enabled attribute is a check name, which must be treated
8618 -- specially and not touched by Resolve.
8620 when Attribute_Enabled =>
8623 --------------------
8624 -- Mechanism_Code --
8625 --------------------
8627 -- Prefix of the Mechanism_Code attribute is a function name
8628 -- which must not be resolved. Should we check for overloaded ???
8630 when Attribute_Mechanism_Code =>
8637 -- Most processing is done in sem_dist, after determining the
8638 -- context type. Node is rewritten as a conversion to a runtime call.
8640 when Attribute_Partition_ID =>
8641 Process_Partition_Id (N);
8648 when Attribute_Pool_Address =>
8655 -- We replace the Range attribute node with a range expression whose
8656 -- bounds are the 'First and 'Last attributes applied to the same
8657 -- prefix. The reason that we do this transformation here instead of
8658 -- in the expander is that it simplifies other parts of the semantic
8659 -- analysis which assume that the Range has been replaced; thus it
8660 -- must be done even when in semantic-only mode (note that the RM
8661 -- specifically mentions this equivalence, we take care that the
8662 -- prefix is only evaluated once).
8664 when Attribute_Range => Range_Attribute :
8670 if not Is_Entity_Name (P)
8671 or else not Is_Type (Entity (P))
8677 Make_Attribute_Reference (Loc,
8679 Duplicate_Subexpr (P, Name_Req => True),
8680 Attribute_Name => Name_Last,
8681 Expressions => Expressions (N));
8684 Make_Attribute_Reference (Loc,
8686 Attribute_Name => Name_First,
8687 Expressions => Expressions (N));
8689 -- If the original was marked as Must_Not_Freeze (see code
8690 -- in Sem_Ch3.Make_Index), then make sure the rewriting
8691 -- does not freeze either.
8693 if Must_Not_Freeze (N) then
8694 Set_Must_Not_Freeze (HB);
8695 Set_Must_Not_Freeze (LB);
8696 Set_Must_Not_Freeze (Prefix (HB));
8697 Set_Must_Not_Freeze (Prefix (LB));
8700 if Raises_Constraint_Error (Prefix (N)) then
8702 -- Preserve Sloc of prefix in the new bounds, so that
8703 -- the posted warning can be removed if we are within
8704 -- unreachable code.
8706 Set_Sloc (LB, Sloc (Prefix (N)));
8707 Set_Sloc (HB, Sloc (Prefix (N)));
8710 Rewrite (N, Make_Range (Loc, LB, HB));
8711 Analyze_And_Resolve (N, Typ);
8713 -- Ensure that the expanded range does not have side effects
8715 Force_Evaluation (LB);
8716 Force_Evaluation (HB);
8718 -- Normally after resolving attribute nodes, Eval_Attribute
8719 -- is called to do any possible static evaluation of the node.
8720 -- However, here since the Range attribute has just been
8721 -- transformed into a range expression it is no longer an
8722 -- attribute node and therefore the call needs to be avoided
8723 -- and is accomplished by simply returning from the procedure.
8726 end Range_Attribute;
8732 -- We will only come here during the prescan of a spec expression
8733 -- containing a Result attribute. In that case the proper Etype has
8734 -- already been set, and nothing more needs to be done here.
8736 when Attribute_Result =>
8743 -- Prefix must not be resolved in this case, since it is not a
8744 -- real entity reference. No action of any kind is require!
8746 when Attribute_UET_Address =>
8749 ----------------------
8750 -- Unchecked_Access --
8751 ----------------------
8753 -- Processing is shared with Access
8755 -------------------------
8756 -- Unrestricted_Access --
8757 -------------------------
8759 -- Processing is shared with Access
8765 -- Apply range check. Note that we did not do this during the
8766 -- analysis phase, since we wanted Eval_Attribute to have a
8767 -- chance at finding an illegal out of range value.
8769 when Attribute_Val =>
8771 -- Note that we do our own Eval_Attribute call here rather than
8772 -- use the common one, because we need to do processing after
8773 -- the call, as per above comment.
8777 -- Eval_Attribute may replace the node with a raise CE, or
8778 -- fold it to a constant. Obviously we only apply a scalar
8779 -- range check if this did not happen!
8781 if Nkind (N) = N_Attribute_Reference
8782 and then Attribute_Name (N) = Name_Val
8784 Apply_Scalar_Range_Check (First (Expressions (N)), Btyp);
8793 -- Prefix of Version attribute can be a subprogram name which
8794 -- must not be resolved, since this is not a call.
8796 when Attribute_Version =>
8799 ----------------------
8800 -- Other Attributes --
8801 ----------------------
8803 -- For other attributes, resolve prefix unless it is a type. If
8804 -- the attribute reference itself is a type name ('Base and 'Class)
8805 -- then this is only legal within a task or protected record.
8808 if not Is_Entity_Name (P)
8809 or else not Is_Type (Entity (P))
8814 -- If the attribute reference itself is a type name ('Base,
8815 -- 'Class) then this is only legal within a task or protected
8816 -- record. What is this all about ???
8818 if Is_Entity_Name (N)
8819 and then Is_Type (Entity (N))
8821 if Is_Concurrent_Type (Entity (N))
8822 and then In_Open_Scopes (Entity (P))
8827 ("invalid use of subtype name in expression or call", N);
8831 -- For attributes whose argument may be a string, complete
8832 -- resolution of argument now. This avoids premature expansion
8833 -- (and the creation of transient scopes) before the attribute
8834 -- reference is resolved.
8837 when Attribute_Value =>
8838 Resolve (First (Expressions (N)), Standard_String);
8840 when Attribute_Wide_Value =>
8841 Resolve (First (Expressions (N)), Standard_Wide_String);
8843 when Attribute_Wide_Wide_Value =>
8844 Resolve (First (Expressions (N)), Standard_Wide_Wide_String);
8846 when others => null;
8849 -- If the prefix of the attribute is a class-wide type then it
8850 -- will be expanded into a dispatching call to a predefined
8851 -- primitive. Therefore we must check for potential violation
8852 -- of such restriction.
8854 if Is_Class_Wide_Type (Etype (P)) then
8855 Check_Restriction (No_Dispatching_Calls, N);
8859 -- Normally the Freezing is done by Resolve but sometimes the Prefix
8860 -- is not resolved, in which case the freezing must be done now.
8862 Freeze_Expression (P);
8864 -- Finally perform static evaluation on the attribute reference
8867 end Resolve_Attribute;
8869 --------------------------------
8870 -- Stream_Attribute_Available --
8871 --------------------------------
8873 function Stream_Attribute_Available
8875 Nam : TSS_Name_Type;
8876 Partial_View : Node_Id := Empty) return Boolean
8878 Etyp : Entity_Id := Typ;
8880 -- Start of processing for Stream_Attribute_Available
8883 -- We need some comments in this body ???
8885 if Has_Stream_Attribute_Definition (Typ, Nam) then
8889 if Is_Class_Wide_Type (Typ) then
8890 return not Is_Limited_Type (Typ)
8891 or else Stream_Attribute_Available (Etype (Typ), Nam);
8894 if Nam = TSS_Stream_Input
8895 and then Is_Abstract_Type (Typ)
8896 and then not Is_Class_Wide_Type (Typ)
8901 if not (Is_Limited_Type (Typ)
8902 or else (Present (Partial_View)
8903 and then Is_Limited_Type (Partial_View)))
8908 -- In Ada 2005, Input can invoke Read, and Output can invoke Write
8910 if Nam = TSS_Stream_Input
8911 and then Ada_Version >= Ada_2005
8912 and then Stream_Attribute_Available (Etyp, TSS_Stream_Read)
8916 elsif Nam = TSS_Stream_Output
8917 and then Ada_Version >= Ada_2005
8918 and then Stream_Attribute_Available (Etyp, TSS_Stream_Write)
8923 -- Case of Read and Write: check for attribute definition clause that
8924 -- applies to an ancestor type.
8926 while Etype (Etyp) /= Etyp loop
8927 Etyp := Etype (Etyp);
8929 if Has_Stream_Attribute_Definition (Etyp, Nam) then
8934 if Ada_Version < Ada_2005 then
8936 -- In Ada 95 mode, also consider a non-visible definition
8939 Btyp : constant Entity_Id := Implementation_Base_Type (Typ);
8942 and then Stream_Attribute_Available
8943 (Btyp, Nam, Partial_View => Typ);
8948 end Stream_Attribute_Available;