1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2011, 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.
220 -- The legality rule only applies to scalar types, even though the
221 -- current AI mentions all subtypes.
223 procedure Check_Array_Or_Scalar_Type;
224 -- Common procedure used by First, Last, Range attribute to check
225 -- that the prefix is a constrained array or scalar type, or a name
226 -- of an array object, and that an argument appears only if appropriate
227 -- (i.e. only in the array case).
229 procedure Check_Array_Type;
230 -- Common semantic checks for all array attributes. Checks that the
231 -- prefix is a constrained array type or the name of an array object.
232 -- The error message for non-arrays is specialized appropriately.
234 procedure Check_Asm_Attribute;
235 -- Common semantic checks for Asm_Input and Asm_Output attributes
237 procedure Check_Component;
238 -- Common processing for Bit_Position, First_Bit, Last_Bit, and
239 -- Position. Checks prefix is an appropriate selected component.
241 procedure Check_Decimal_Fixed_Point_Type;
242 -- Check that prefix of attribute N is a decimal fixed-point type
244 procedure Check_Dereference;
245 -- If the prefix of attribute is an object of an access type, then
246 -- introduce an explicit dereference, and adjust P_Type accordingly.
248 procedure Check_Discrete_Type;
249 -- Verify that prefix of attribute N is a discrete type
252 -- Check that no attribute arguments are present
254 procedure Check_Either_E0_Or_E1;
255 -- Check that there are zero or one attribute arguments present
258 -- Check that exactly one attribute argument is present
261 -- Check that two attribute arguments are present
263 procedure Check_Enum_Image;
264 -- If the prefix type is an enumeration type, set all its literals
265 -- as referenced, since the image function could possibly end up
266 -- referencing any of the literals indirectly. Same for Enum_Val.
268 procedure Check_Fixed_Point_Type;
269 -- Verify that prefix of attribute N is a fixed type
271 procedure Check_Fixed_Point_Type_0;
272 -- Verify that prefix of attribute N is a fixed type and that
273 -- no attribute expressions are present
275 procedure Check_Floating_Point_Type;
276 -- Verify that prefix of attribute N is a float type
278 procedure Check_Floating_Point_Type_0;
279 -- Verify that prefix of attribute N is a float type and that
280 -- no attribute expressions are present
282 procedure Check_Floating_Point_Type_1;
283 -- Verify that prefix of attribute N is a float type and that
284 -- exactly one attribute expression is present
286 procedure Check_Floating_Point_Type_2;
287 -- Verify that prefix of attribute N is a float type and that
288 -- two attribute expressions are present
290 procedure Legal_Formal_Attribute;
291 -- Common processing for attributes Definite and Has_Discriminants.
292 -- Checks that prefix is generic indefinite formal type.
294 procedure Check_SPARK_Restriction_On_Attribute;
295 -- Issue an error in formal mode because attribute N is allowed
297 procedure Check_Integer_Type;
298 -- Verify that prefix of attribute N is an integer type
300 procedure Check_Modular_Integer_Type;
301 -- Verify that prefix of attribute N is a modular integer type
303 procedure Check_Not_CPP_Type;
304 -- Check that P (the prefix of the attribute) is not an CPP type
305 -- for which no Ada predefined primitive is available.
307 procedure Check_Not_Incomplete_Type;
308 -- Check that P (the prefix of the attribute) is not an incomplete
309 -- type or a private type for which no full view has been given.
311 procedure Check_Object_Reference (P : Node_Id);
312 -- Check that P (the prefix of the attribute) is an object reference
314 procedure Check_Program_Unit;
315 -- Verify that prefix of attribute N is a program unit
317 procedure Check_Real_Type;
318 -- Verify that prefix of attribute N is fixed or float type
320 procedure Check_Scalar_Type;
321 -- Verify that prefix of attribute N is a scalar type
323 procedure Check_Standard_Prefix;
324 -- Verify that prefix of attribute N is package Standard
326 procedure Check_Stream_Attribute (Nam : TSS_Name_Type);
327 -- Validity checking for stream attribute. Nam is the TSS name of the
328 -- corresponding possible defined attribute function (e.g. for the
329 -- Read attribute, Nam will be TSS_Stream_Read).
331 procedure Check_PolyORB_Attribute;
332 -- Validity checking for PolyORB/DSA attribute
334 procedure Check_Task_Prefix;
335 -- Verify that prefix of attribute N is a task or task type
337 procedure Check_Type;
338 -- Verify that the prefix of attribute N is a type
340 procedure Check_Unit_Name (Nod : Node_Id);
341 -- Check that Nod is of the form of a library unit name, i.e that
342 -- it is an identifier, or a selected component whose prefix is
343 -- itself of the form of a library unit name. Note that this is
344 -- quite different from Check_Program_Unit, since it only checks
345 -- the syntactic form of the name, not the semantic identity. This
346 -- is because it is used with attributes (Elab_Body, Elab_Spec,
347 -- UET_Address and Elaborated) which can refer to non-visible unit.
349 procedure Error_Attr (Msg : String; Error_Node : Node_Id);
350 pragma No_Return (Error_Attr);
351 procedure Error_Attr;
352 pragma No_Return (Error_Attr);
353 -- Posts error using Error_Msg_N at given node, sets type of attribute
354 -- node to Any_Type, and then raises Bad_Attribute to avoid any further
355 -- semantic processing. The message typically contains a % insertion
356 -- character which is replaced by the attribute name. The call with
357 -- no arguments is used when the caller has already generated the
358 -- required error messages.
360 procedure Error_Attr_P (Msg : String);
361 pragma No_Return (Error_Attr);
362 -- Like Error_Attr, but error is posted at the start of the prefix
364 procedure Standard_Attribute (Val : Int);
365 -- Used to process attributes whose prefix is package Standard which
366 -- yield values of type Universal_Integer. The attribute reference
367 -- node is rewritten with an integer literal of the given value.
369 procedure Unexpected_Argument (En : Node_Id);
370 -- Signal unexpected attribute argument (En is the argument)
372 procedure Validate_Non_Static_Attribute_Function_Call;
373 -- Called when processing an attribute that is a function call to a
374 -- non-static function, i.e. an attribute function that either takes
375 -- non-scalar arguments or returns a non-scalar result. Verifies that
376 -- such a call does not appear in a preelaborable context.
378 ------------------------------
379 -- Analyze_Access_Attribute --
380 ------------------------------
382 procedure Analyze_Access_Attribute is
383 Acc_Type : Entity_Id;
388 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id;
389 -- Build an access-to-object type whose designated type is DT,
390 -- and whose Ekind is appropriate to the attribute type. The
391 -- type that is constructed is returned as the result.
393 procedure Build_Access_Subprogram_Type (P : Node_Id);
394 -- Build an access to subprogram whose designated type is the type of
395 -- the prefix. If prefix is overloaded, so is the node itself. The
396 -- result is stored in Acc_Type.
398 function OK_Self_Reference return Boolean;
399 -- An access reference whose prefix is a type can legally appear
400 -- within an aggregate, where it is obtained by expansion of
401 -- a defaulted aggregate. The enclosing aggregate that contains
402 -- the self-referenced is flagged so that the self-reference can
403 -- be expanded into a reference to the target object (see exp_aggr).
405 ------------------------------
406 -- Build_Access_Object_Type --
407 ------------------------------
409 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id is
410 Typ : constant Entity_Id :=
412 (E_Access_Attribute_Type, Current_Scope, Loc, 'A');
414 Set_Etype (Typ, Typ);
416 Set_Associated_Node_For_Itype (Typ, N);
417 Set_Directly_Designated_Type (Typ, DT);
419 end Build_Access_Object_Type;
421 ----------------------------------
422 -- Build_Access_Subprogram_Type --
423 ----------------------------------
425 procedure Build_Access_Subprogram_Type (P : Node_Id) is
426 Index : Interp_Index;
429 procedure Check_Local_Access (E : Entity_Id);
430 -- Deal with possible access to local subprogram. If we have such
431 -- an access, we set a flag to kill all tracked values on any call
432 -- because this access value may be passed around, and any called
433 -- code might use it to access a local procedure which clobbers a
434 -- tracked value. If the scope is a loop or block, indicate that
435 -- value tracking is disabled for the enclosing subprogram.
437 function Get_Kind (E : Entity_Id) return Entity_Kind;
438 -- Distinguish between access to regular/protected subprograms
440 ------------------------
441 -- Check_Local_Access --
442 ------------------------
444 procedure Check_Local_Access (E : Entity_Id) is
446 if not Is_Library_Level_Entity (E) then
447 Set_Suppress_Value_Tracking_On_Call (Current_Scope);
448 Set_Suppress_Value_Tracking_On_Call
449 (Nearest_Dynamic_Scope (Current_Scope));
451 end Check_Local_Access;
457 function Get_Kind (E : Entity_Id) return Entity_Kind is
459 if Convention (E) = Convention_Protected then
460 return E_Access_Protected_Subprogram_Type;
462 return E_Access_Subprogram_Type;
466 -- Start of processing for Build_Access_Subprogram_Type
469 -- In the case of an access to subprogram, use the name of the
470 -- subprogram itself as the designated type. Type-checking in
471 -- this case compares the signatures of the designated types.
473 -- Note: This fragment of the tree is temporarily malformed
474 -- because the correct tree requires an E_Subprogram_Type entity
475 -- as the designated type. In most cases this designated type is
476 -- later overridden by the semantics with the type imposed by the
477 -- context during the resolution phase. In the specific case of
478 -- the expression Address!(Prim'Unrestricted_Access), used to
479 -- initialize slots of dispatch tables, this work will be done by
480 -- the expander (see Exp_Aggr).
482 -- The reason to temporarily add this kind of node to the tree
483 -- instead of a proper E_Subprogram_Type itype, is the following:
484 -- in case of errors found in the source file we report better
485 -- error messages. For example, instead of generating the
488 -- "expected access to subprogram with profile
489 -- defined at line X"
491 -- we currently generate:
493 -- "expected access to function Z defined at line X"
495 Set_Etype (N, Any_Type);
497 if not Is_Overloaded (P) then
498 Check_Local_Access (Entity (P));
500 if not Is_Intrinsic_Subprogram (Entity (P)) then
501 Acc_Type := Create_Itype (Get_Kind (Entity (P)), N);
502 Set_Is_Public (Acc_Type, False);
503 Set_Etype (Acc_Type, Acc_Type);
504 Set_Convention (Acc_Type, Convention (Entity (P)));
505 Set_Directly_Designated_Type (Acc_Type, Entity (P));
506 Set_Etype (N, Acc_Type);
507 Freeze_Before (N, Acc_Type);
511 Get_First_Interp (P, Index, It);
512 while Present (It.Nam) loop
513 Check_Local_Access (It.Nam);
515 if not Is_Intrinsic_Subprogram (It.Nam) then
516 Acc_Type := Create_Itype (Get_Kind (It.Nam), N);
517 Set_Is_Public (Acc_Type, False);
518 Set_Etype (Acc_Type, Acc_Type);
519 Set_Convention (Acc_Type, Convention (It.Nam));
520 Set_Directly_Designated_Type (Acc_Type, It.Nam);
521 Add_One_Interp (N, Acc_Type, Acc_Type);
522 Freeze_Before (N, Acc_Type);
525 Get_Next_Interp (Index, It);
529 -- Cannot be applied to intrinsic. Looking at the tests above,
530 -- the only way Etype (N) can still be set to Any_Type is if
531 -- Is_Intrinsic_Subprogram was True for some referenced entity.
533 if Etype (N) = Any_Type then
534 Error_Attr_P ("prefix of % attribute cannot be intrinsic");
536 end Build_Access_Subprogram_Type;
538 ----------------------
539 -- OK_Self_Reference --
540 ----------------------
542 function OK_Self_Reference return Boolean is
549 (Nkind (Par) = N_Component_Association
550 or else Nkind (Par) in N_Subexpr)
552 if Nkind_In (Par, N_Aggregate, N_Extension_Aggregate) then
553 if Etype (Par) = Typ then
554 Set_Has_Self_Reference (Par);
562 -- No enclosing aggregate, or not a self-reference
565 end OK_Self_Reference;
567 -- Start of processing for Analyze_Access_Attribute
570 Check_SPARK_Restriction_On_Attribute;
573 if Nkind (P) = N_Character_Literal then
575 ("prefix of % attribute cannot be enumeration literal");
578 -- Case of access to subprogram
580 if Is_Entity_Name (P)
581 and then Is_Overloadable (Entity (P))
583 if Has_Pragma_Inline_Always (Entity (P)) then
585 ("prefix of % attribute cannot be Inline_Always subprogram");
588 if Aname = Name_Unchecked_Access then
589 Error_Attr ("attribute% cannot be applied to a subprogram", P);
592 -- Issue an error if the prefix denotes an eliminated subprogram
594 Check_For_Eliminated_Subprogram (P, Entity (P));
596 -- Check for obsolescent subprogram reference
598 Check_Obsolescent_2005_Entity (Entity (P), P);
600 -- Build the appropriate subprogram type
602 Build_Access_Subprogram_Type (P);
604 -- For unrestricted access, kill current values, since this
605 -- attribute allows a reference to a local subprogram that
606 -- could modify local variables to be passed out of scope
608 if Aname = Name_Unrestricted_Access then
610 -- Do not kill values on nodes initializing dispatch tables
611 -- slots. The construct Prim_Ptr!(Prim'Unrestricted_Access)
612 -- is currently generated by the expander only for this
613 -- purpose. Done to keep the quality of warnings currently
614 -- generated by the compiler (otherwise any declaration of
615 -- a tagged type cleans constant indications from its scope).
617 if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
618 and then (Etype (Parent (N)) = RTE (RE_Prim_Ptr)
620 Etype (Parent (N)) = RTE (RE_Size_Ptr))
621 and then Is_Dispatching_Operation
622 (Directly_Designated_Type (Etype (N)))
632 -- Component is an operation of a protected type
634 elsif Nkind (P) = N_Selected_Component
635 and then Is_Overloadable (Entity (Selector_Name (P)))
637 if Ekind (Entity (Selector_Name (P))) = E_Entry then
638 Error_Attr_P ("prefix of % attribute must be subprogram");
641 Build_Access_Subprogram_Type (Selector_Name (P));
645 -- Deal with incorrect reference to a type, but note that some
646 -- accesses are allowed: references to the current type instance,
647 -- or in Ada 2005 self-referential pointer in a default-initialized
650 if Is_Entity_Name (P) then
653 -- The reference may appear in an aggregate that has been expanded
654 -- into a loop. Locate scope of type definition, if any.
656 Scop := Current_Scope;
657 while Ekind (Scop) = E_Loop loop
658 Scop := Scope (Scop);
661 if Is_Type (Typ) then
663 -- OK if we are within the scope of a limited type
664 -- let's mark the component as having per object constraint
666 if Is_Anonymous_Tagged_Base (Scop, Typ) then
674 Q : Node_Id := Parent (N);
678 and then Nkind (Q) /= N_Component_Declaration
684 Set_Has_Per_Object_Constraint
685 (Defining_Identifier (Q), True);
689 if Nkind (P) = N_Expanded_Name then
691 ("current instance prefix must be a direct name", P);
694 -- If a current instance attribute appears in a component
695 -- constraint it must appear alone; other contexts (spec-
696 -- expressions, within a task body) are not subject to this
699 if not In_Spec_Expression
700 and then not Has_Completion (Scop)
702 Nkind_In (Parent (N), N_Discriminant_Association,
703 N_Index_Or_Discriminant_Constraint)
706 ("current instance attribute must appear alone", N);
709 if Is_CPP_Class (Root_Type (Typ)) then
711 ("?current instance unsupported for derivations of "
712 & "'C'P'P types", N);
715 -- OK if we are in initialization procedure for the type
716 -- in question, in which case the reference to the type
717 -- is rewritten as a reference to the current object.
719 elsif Ekind (Scop) = E_Procedure
720 and then Is_Init_Proc (Scop)
721 and then Etype (First_Formal (Scop)) = Typ
724 Make_Attribute_Reference (Loc,
725 Prefix => Make_Identifier (Loc, Name_uInit),
726 Attribute_Name => Name_Unrestricted_Access));
730 -- OK if a task type, this test needs sharpening up ???
732 elsif Is_Task_Type (Typ) then
735 -- OK if self-reference in an aggregate in Ada 2005, and
736 -- the reference comes from a copied default expression.
738 -- Note that we check legality of self-reference even if the
739 -- expression comes from source, e.g. when a single component
740 -- association in an aggregate has a box association.
742 elsif Ada_Version >= Ada_2005
743 and then OK_Self_Reference
747 -- OK if reference to current instance of a protected object
749 elsif Is_Protected_Self_Reference (P) then
752 -- Otherwise we have an error case
755 Error_Attr ("% attribute cannot be applied to type", P);
761 -- If we fall through, we have a normal access to object case.
762 -- Unrestricted_Access is legal wherever an allocator would be
763 -- legal, so its Etype is set to E_Allocator. The expected type
764 -- of the other attributes is a general access type, and therefore
765 -- we label them with E_Access_Attribute_Type.
767 if not Is_Overloaded (P) then
768 Acc_Type := Build_Access_Object_Type (P_Type);
769 Set_Etype (N, Acc_Type);
772 Index : Interp_Index;
775 Set_Etype (N, Any_Type);
776 Get_First_Interp (P, Index, It);
777 while Present (It.Typ) loop
778 Acc_Type := Build_Access_Object_Type (It.Typ);
779 Add_One_Interp (N, Acc_Type, Acc_Type);
780 Get_Next_Interp (Index, It);
785 -- Special cases when we can find a prefix that is an entity name
794 if Is_Entity_Name (PP) then
797 -- If we have an access to an object, and the attribute
798 -- comes from source, then set the object as potentially
799 -- source modified. We do this because the resulting access
800 -- pointer can be used to modify the variable, and we might
801 -- not detect this, leading to some junk warnings.
803 Set_Never_Set_In_Source (Ent, False);
805 -- Mark entity as address taken, and kill current values
807 Set_Address_Taken (Ent);
808 Kill_Current_Values (Ent);
811 elsif Nkind_In (PP, N_Selected_Component,
822 -- Check for aliased view unless unrestricted case. We allow a
823 -- nonaliased prefix when within an instance because the prefix may
824 -- have been a tagged formal object, which is defined to be aliased
825 -- even when the actual might not be (other instance cases will have
826 -- been caught in the generic). Similarly, within an inlined body we
827 -- know that the attribute is legal in the original subprogram, and
828 -- therefore legal in the expansion.
830 if Aname /= Name_Unrestricted_Access
831 and then not Is_Aliased_View (P)
832 and then not In_Instance
833 and then not In_Inlined_Body
835 Error_Attr_P ("prefix of % attribute must be aliased");
837 end Analyze_Access_Attribute;
839 ---------------------------------
840 -- Bad_Attribute_For_Predicate --
841 ---------------------------------
843 procedure Bad_Attribute_For_Predicate is
845 if Is_Scalar_Type (P_Type)
846 and then Comes_From_Source (N)
848 Error_Msg_Name_1 := Aname;
849 Bad_Predicated_Subtype_Use
850 ("type& has predicates, attribute % not allowed", N, P_Type);
852 end Bad_Attribute_For_Predicate;
854 --------------------------------
855 -- Check_Array_Or_Scalar_Type --
856 --------------------------------
858 procedure Check_Array_Or_Scalar_Type is
862 -- Dimension number for array attributes
865 -- Case of string literal or string literal subtype. These cases
866 -- cannot arise from legal Ada code, but the expander is allowed
867 -- to generate them. They require special handling because string
868 -- literal subtypes do not have standard bounds (the whole idea
869 -- of these subtypes is to avoid having to generate the bounds)
871 if Ekind (P_Type) = E_String_Literal_Subtype then
872 Set_Etype (N, Etype (First_Index (P_Base_Type)));
877 elsif Is_Scalar_Type (P_Type) then
881 Error_Attr ("invalid argument in % attribute", E1);
883 Set_Etype (N, P_Base_Type);
887 -- The following is a special test to allow 'First to apply to
888 -- private scalar types if the attribute comes from generated
889 -- code. This occurs in the case of Normalize_Scalars code.
891 elsif Is_Private_Type (P_Type)
892 and then Present (Full_View (P_Type))
893 and then Is_Scalar_Type (Full_View (P_Type))
894 and then not Comes_From_Source (N)
896 Set_Etype (N, Implementation_Base_Type (P_Type));
898 -- Array types other than string literal subtypes handled above
903 -- We know prefix is an array type, or the name of an array
904 -- object, and that the expression, if present, is static
905 -- and within the range of the dimensions of the type.
907 pragma Assert (Is_Array_Type (P_Type));
908 Index := First_Index (P_Base_Type);
912 -- First dimension assumed
914 Set_Etype (N, Base_Type (Etype (Index)));
917 D := UI_To_Int (Intval (E1));
919 for J in 1 .. D - 1 loop
923 Set_Etype (N, Base_Type (Etype (Index)));
924 Set_Etype (E1, Standard_Integer);
927 end Check_Array_Or_Scalar_Type;
929 ----------------------
930 -- Check_Array_Type --
931 ----------------------
933 procedure Check_Array_Type is
935 -- Dimension number for array attributes
938 -- If the type is a string literal type, then this must be generated
939 -- internally, and no further check is required on its legality.
941 if Ekind (P_Type) = E_String_Literal_Subtype then
944 -- If the type is a composite, it is an illegal aggregate, no point
947 elsif P_Type = Any_Composite then
951 -- Normal case of array type or subtype
953 Check_Either_E0_Or_E1;
956 if Is_Array_Type (P_Type) then
957 if not Is_Constrained (P_Type)
958 and then Is_Entity_Name (P)
959 and then Is_Type (Entity (P))
961 -- Note: we do not call Error_Attr here, since we prefer to
962 -- continue, using the relevant index type of the array,
963 -- even though it is unconstrained. This gives better error
964 -- recovery behavior.
966 Error_Msg_Name_1 := Aname;
968 ("prefix for % attribute must be constrained array", P);
971 D := Number_Dimensions (P_Type);
974 if Is_Private_Type (P_Type) then
975 Error_Attr_P ("prefix for % attribute may not be private type");
977 elsif Is_Access_Type (P_Type)
978 and then Is_Array_Type (Designated_Type (P_Type))
979 and then Is_Entity_Name (P)
980 and then Is_Type (Entity (P))
982 Error_Attr_P ("prefix of % attribute cannot be access type");
984 elsif Attr_Id = Attribute_First
986 Attr_Id = Attribute_Last
988 Error_Attr ("invalid prefix for % attribute", P);
991 Error_Attr_P ("prefix for % attribute must be array");
996 Resolve (E1, Any_Integer);
997 Set_Etype (E1, Standard_Integer);
999 if not Is_Static_Expression (E1)
1000 or else Raises_Constraint_Error (E1)
1002 Flag_Non_Static_Expr
1003 ("expression for dimension must be static!", E1);
1006 elsif UI_To_Int (Expr_Value (E1)) > D
1007 or else UI_To_Int (Expr_Value (E1)) < 1
1009 Error_Attr ("invalid dimension number for array type", E1);
1013 if (Style_Check and Style_Check_Array_Attribute_Index)
1014 and then Comes_From_Source (N)
1016 Style.Check_Array_Attribute_Index (N, E1, D);
1018 end Check_Array_Type;
1020 -------------------------
1021 -- Check_Asm_Attribute --
1022 -------------------------
1024 procedure Check_Asm_Attribute is
1029 -- Check first argument is static string expression
1031 Analyze_And_Resolve (E1, Standard_String);
1033 if Etype (E1) = Any_Type then
1036 elsif not Is_OK_Static_Expression (E1) then
1037 Flag_Non_Static_Expr
1038 ("constraint argument must be static string expression!", E1);
1042 -- Check second argument is right type
1044 Analyze_And_Resolve (E2, Entity (P));
1046 -- Note: that is all we need to do, we don't need to check
1047 -- that it appears in a correct context. The Ada type system
1048 -- will do that for us.
1050 end Check_Asm_Attribute;
1052 ---------------------
1053 -- Check_Component --
1054 ---------------------
1056 procedure Check_Component is
1060 if Nkind (P) /= N_Selected_Component
1062 (Ekind (Entity (Selector_Name (P))) /= E_Component
1064 Ekind (Entity (Selector_Name (P))) /= E_Discriminant)
1066 Error_Attr_P ("prefix for % attribute must be selected component");
1068 end Check_Component;
1070 ------------------------------------
1071 -- Check_Decimal_Fixed_Point_Type --
1072 ------------------------------------
1074 procedure Check_Decimal_Fixed_Point_Type is
1078 if not Is_Decimal_Fixed_Point_Type (P_Type) then
1079 Error_Attr_P ("prefix of % attribute must be decimal type");
1081 end Check_Decimal_Fixed_Point_Type;
1083 -----------------------
1084 -- Check_Dereference --
1085 -----------------------
1087 procedure Check_Dereference is
1090 -- Case of a subtype mark
1092 if Is_Entity_Name (P)
1093 and then Is_Type (Entity (P))
1098 -- Case of an expression
1102 if Is_Access_Type (P_Type) then
1104 -- If there is an implicit dereference, then we must freeze
1105 -- the designated type of the access type, since the type of
1106 -- the referenced array is this type (see AI95-00106).
1108 -- As done elsewhere, freezing must not happen when pre-analyzing
1109 -- a pre- or postcondition or a default value for an object or
1110 -- for a formal parameter.
1112 if not In_Spec_Expression then
1113 Freeze_Before (N, Designated_Type (P_Type));
1117 Make_Explicit_Dereference (Sloc (P),
1118 Prefix => Relocate_Node (P)));
1120 Analyze_And_Resolve (P);
1121 P_Type := Etype (P);
1123 if P_Type = Any_Type then
1124 raise Bad_Attribute;
1127 P_Base_Type := Base_Type (P_Type);
1129 end Check_Dereference;
1131 -------------------------
1132 -- Check_Discrete_Type --
1133 -------------------------
1135 procedure Check_Discrete_Type is
1139 if not Is_Discrete_Type (P_Type) then
1140 Error_Attr_P ("prefix of % attribute must be discrete type");
1142 end Check_Discrete_Type;
1148 procedure Check_E0 is
1150 if Present (E1) then
1151 Unexpected_Argument (E1);
1159 procedure Check_E1 is
1161 Check_Either_E0_Or_E1;
1165 -- Special-case attributes that are functions and that appear as
1166 -- the prefix of another attribute. Error is posted on parent.
1168 if Nkind (Parent (N)) = N_Attribute_Reference
1169 and then (Attribute_Name (Parent (N)) = Name_Address
1171 Attribute_Name (Parent (N)) = Name_Code_Address
1173 Attribute_Name (Parent (N)) = Name_Access)
1175 Error_Msg_Name_1 := Attribute_Name (Parent (N));
1176 Error_Msg_N ("illegal prefix for % attribute", Parent (N));
1177 Set_Etype (Parent (N), Any_Type);
1178 Set_Entity (Parent (N), Any_Type);
1179 raise Bad_Attribute;
1182 Error_Attr ("missing argument for % attribute", N);
1191 procedure Check_E2 is
1194 Error_Attr ("missing arguments for % attribute (2 required)", N);
1196 Error_Attr ("missing argument for % attribute (2 required)", N);
1200 ---------------------------
1201 -- Check_Either_E0_Or_E1 --
1202 ---------------------------
1204 procedure Check_Either_E0_Or_E1 is
1206 if Present (E2) then
1207 Unexpected_Argument (E2);
1209 end Check_Either_E0_Or_E1;
1211 ----------------------
1212 -- Check_Enum_Image --
1213 ----------------------
1215 procedure Check_Enum_Image is
1218 if Is_Enumeration_Type (P_Base_Type) then
1219 Lit := First_Literal (P_Base_Type);
1220 while Present (Lit) loop
1221 Set_Referenced (Lit);
1225 end Check_Enum_Image;
1227 ----------------------------
1228 -- Check_Fixed_Point_Type --
1229 ----------------------------
1231 procedure Check_Fixed_Point_Type is
1235 if not Is_Fixed_Point_Type (P_Type) then
1236 Error_Attr_P ("prefix of % attribute must be fixed point type");
1238 end Check_Fixed_Point_Type;
1240 ------------------------------
1241 -- Check_Fixed_Point_Type_0 --
1242 ------------------------------
1244 procedure Check_Fixed_Point_Type_0 is
1246 Check_Fixed_Point_Type;
1248 end Check_Fixed_Point_Type_0;
1250 -------------------------------
1251 -- Check_Floating_Point_Type --
1252 -------------------------------
1254 procedure Check_Floating_Point_Type is
1258 if not Is_Floating_Point_Type (P_Type) then
1259 Error_Attr_P ("prefix of % attribute must be float type");
1261 end Check_Floating_Point_Type;
1263 ---------------------------------
1264 -- Check_Floating_Point_Type_0 --
1265 ---------------------------------
1267 procedure Check_Floating_Point_Type_0 is
1269 Check_Floating_Point_Type;
1271 end Check_Floating_Point_Type_0;
1273 ---------------------------------
1274 -- Check_Floating_Point_Type_1 --
1275 ---------------------------------
1277 procedure Check_Floating_Point_Type_1 is
1279 Check_Floating_Point_Type;
1281 end Check_Floating_Point_Type_1;
1283 ---------------------------------
1284 -- Check_Floating_Point_Type_2 --
1285 ---------------------------------
1287 procedure Check_Floating_Point_Type_2 is
1289 Check_Floating_Point_Type;
1291 end Check_Floating_Point_Type_2;
1293 ------------------------
1294 -- Check_Integer_Type --
1295 ------------------------
1297 procedure Check_Integer_Type is
1301 if not Is_Integer_Type (P_Type) then
1302 Error_Attr_P ("prefix of % attribute must be integer type");
1304 end Check_Integer_Type;
1306 --------------------------------
1307 -- Check_Modular_Integer_Type --
1308 --------------------------------
1310 procedure Check_Modular_Integer_Type is
1314 if not Is_Modular_Integer_Type (P_Type) then
1316 ("prefix of % attribute must be modular integer type");
1318 end Check_Modular_Integer_Type;
1320 ------------------------
1321 -- Check_Not_CPP_Type --
1322 ------------------------
1324 procedure Check_Not_CPP_Type is
1326 if Is_Tagged_Type (Etype (P))
1327 and then Convention (Etype (P)) = Convention_CPP
1328 and then Is_CPP_Class (Root_Type (Etype (P)))
1331 ("invalid use of % attribute with 'C'P'P tagged type");
1333 end Check_Not_CPP_Type;
1335 -------------------------------
1336 -- Check_Not_Incomplete_Type --
1337 -------------------------------
1339 procedure Check_Not_Incomplete_Type is
1344 -- Ada 2005 (AI-50217, AI-326): If the prefix is an explicit
1345 -- dereference we have to check wrong uses of incomplete types
1346 -- (other wrong uses are checked at their freezing point).
1348 -- Example 1: Limited-with
1350 -- limited with Pkg;
1352 -- type Acc is access Pkg.T;
1354 -- S : Integer := X.all'Size; -- ERROR
1357 -- Example 2: Tagged incomplete
1359 -- type T is tagged;
1360 -- type Acc is access all T;
1362 -- S : constant Integer := X.all'Size; -- ERROR
1363 -- procedure Q (Obj : Integer := X.all'Alignment); -- ERROR
1365 if Ada_Version >= Ada_2005
1366 and then Nkind (P) = N_Explicit_Dereference
1369 while Nkind (E) = N_Explicit_Dereference loop
1375 if From_With_Type (Typ) then
1377 ("prefix of % attribute cannot be an incomplete type");
1380 if Is_Access_Type (Typ) then
1381 Typ := Directly_Designated_Type (Typ);
1384 if Is_Class_Wide_Type (Typ) then
1385 Typ := Root_Type (Typ);
1388 -- A legal use of a shadow entity occurs only when the unit
1389 -- where the non-limited view resides is imported via a regular
1390 -- with clause in the current body. Such references to shadow
1391 -- entities may occur in subprogram formals.
1393 if Is_Incomplete_Type (Typ)
1394 and then From_With_Type (Typ)
1395 and then Present (Non_Limited_View (Typ))
1396 and then Is_Legal_Shadow_Entity_In_Body (Typ)
1398 Typ := Non_Limited_View (Typ);
1401 if Ekind (Typ) = E_Incomplete_Type
1402 and then No (Full_View (Typ))
1405 ("prefix of % attribute cannot be an incomplete type");
1410 if not Is_Entity_Name (P)
1411 or else not Is_Type (Entity (P))
1412 or else In_Spec_Expression
1416 Check_Fully_Declared (P_Type, P);
1418 end Check_Not_Incomplete_Type;
1420 ----------------------------
1421 -- Check_Object_Reference --
1422 ----------------------------
1424 procedure Check_Object_Reference (P : Node_Id) is
1428 -- If we need an object, and we have a prefix that is the name of
1429 -- a function entity, convert it into a function call.
1431 if Is_Entity_Name (P)
1432 and then Ekind (Entity (P)) = E_Function
1434 Rtyp := Etype (Entity (P));
1437 Make_Function_Call (Sloc (P),
1438 Name => Relocate_Node (P)));
1440 Analyze_And_Resolve (P, Rtyp);
1442 -- Otherwise we must have an object reference
1444 elsif not Is_Object_Reference (P) then
1445 Error_Attr_P ("prefix of % attribute must be object");
1447 end Check_Object_Reference;
1449 ----------------------------
1450 -- Check_PolyORB_Attribute --
1451 ----------------------------
1453 procedure Check_PolyORB_Attribute is
1455 Validate_Non_Static_Attribute_Function_Call;
1460 if Get_PCS_Name /= Name_PolyORB_DSA then
1462 ("attribute% requires the 'Poly'O'R'B 'P'C'S", N);
1464 end Check_PolyORB_Attribute;
1466 ------------------------
1467 -- Check_Program_Unit --
1468 ------------------------
1470 procedure Check_Program_Unit is
1472 if Is_Entity_Name (P) then
1474 K : constant Entity_Kind := Ekind (Entity (P));
1475 T : constant Entity_Id := Etype (Entity (P));
1478 if K in Subprogram_Kind
1479 or else K in Task_Kind
1480 or else K in Protected_Kind
1481 or else K = E_Package
1482 or else K in Generic_Unit_Kind
1483 or else (K = E_Variable
1487 Is_Protected_Type (T)))
1494 Error_Attr_P ("prefix of % attribute must be program unit");
1495 end Check_Program_Unit;
1497 ---------------------
1498 -- Check_Real_Type --
1499 ---------------------
1501 procedure Check_Real_Type is
1505 if not Is_Real_Type (P_Type) then
1506 Error_Attr_P ("prefix of % attribute must be real type");
1508 end Check_Real_Type;
1510 -----------------------
1511 -- Check_Scalar_Type --
1512 -----------------------
1514 procedure Check_Scalar_Type is
1518 if not Is_Scalar_Type (P_Type) then
1519 Error_Attr_P ("prefix of % attribute must be scalar type");
1521 end Check_Scalar_Type;
1523 ------------------------------------------
1524 -- Check_SPARK_Restriction_On_Attribute --
1525 ------------------------------------------
1527 procedure Check_SPARK_Restriction_On_Attribute is
1529 Error_Msg_Name_1 := Aname;
1530 Check_SPARK_Restriction ("attribute % is not allowed", P);
1531 end Check_SPARK_Restriction_On_Attribute;
1533 ---------------------------
1534 -- Check_Standard_Prefix --
1535 ---------------------------
1537 procedure Check_Standard_Prefix is
1541 if Nkind (P) /= N_Identifier
1542 or else Chars (P) /= Name_Standard
1544 Error_Attr ("only allowed prefix for % attribute is Standard", P);
1546 end Check_Standard_Prefix;
1548 ----------------------------
1549 -- Check_Stream_Attribute --
1550 ----------------------------
1552 procedure Check_Stream_Attribute (Nam : TSS_Name_Type) is
1556 In_Shared_Var_Procs : Boolean;
1557 -- True when compiling the body of System.Shared_Storage.
1558 -- Shared_Var_Procs. For this runtime package (always compiled in
1559 -- GNAT mode), we allow stream attributes references for limited
1560 -- types for the case where shared passive objects are implemented
1561 -- using stream attributes, which is the default in GNAT's persistent
1562 -- storage implementation.
1565 Validate_Non_Static_Attribute_Function_Call;
1567 -- With the exception of 'Input, Stream attributes are procedures,
1568 -- and can only appear at the position of procedure calls. We check
1569 -- for this here, before they are rewritten, to give a more precise
1572 if Nam = TSS_Stream_Input then
1575 elsif Is_List_Member (N)
1576 and then not Nkind_In (Parent (N), N_Procedure_Call_Statement,
1583 ("invalid context for attribute%, which is a procedure", N);
1587 Btyp := Implementation_Base_Type (P_Type);
1589 -- Stream attributes not allowed on limited types unless the
1590 -- attribute reference was generated by the expander (in which
1591 -- case the underlying type will be used, as described in Sinfo),
1592 -- or the attribute was specified explicitly for the type itself
1593 -- or one of its ancestors (taking visibility rules into account if
1594 -- in Ada 2005 mode), or a pragma Stream_Convert applies to Btyp
1595 -- (with no visibility restriction).
1598 Gen_Body : constant Node_Id := Enclosing_Generic_Body (N);
1600 if Present (Gen_Body) then
1601 In_Shared_Var_Procs :=
1602 Is_RTE (Corresponding_Spec (Gen_Body), RE_Shared_Var_Procs);
1604 In_Shared_Var_Procs := False;
1608 if (Comes_From_Source (N)
1609 and then not (In_Shared_Var_Procs or In_Instance))
1610 and then not Stream_Attribute_Available (P_Type, Nam)
1611 and then not Has_Rep_Pragma (Btyp, Name_Stream_Convert)
1613 Error_Msg_Name_1 := Aname;
1615 if Is_Limited_Type (P_Type) then
1617 ("limited type& has no% attribute", P, P_Type);
1618 Explain_Limited_Type (P_Type, P);
1621 ("attribute% for type& is not available", P, P_Type);
1625 -- Check restriction violations
1627 -- First check the No_Streams restriction, which prohibits the use
1628 -- of explicit stream attributes in the source program. We do not
1629 -- prevent the occurrence of stream attributes in generated code,
1630 -- for instance those generated implicitly for dispatching purposes.
1632 if Comes_From_Source (N) then
1633 Check_Restriction (No_Streams, P);
1636 -- AI05-0057: if restriction No_Default_Stream_Attributes is active,
1637 -- it is illegal to use a predefined elementary type stream attribute
1638 -- either by itself, or more importantly as part of the attribute
1639 -- subprogram for a composite type.
1641 if Restriction_Active (No_Default_Stream_Attributes) then
1646 if Nam = TSS_Stream_Input
1648 Nam = TSS_Stream_Read
1651 Type_Without_Stream_Operation (P_Type, TSS_Stream_Read);
1654 Type_Without_Stream_Operation (P_Type, TSS_Stream_Write);
1658 Check_Restriction (No_Default_Stream_Attributes, N);
1661 ("missing user-defined Stream Read or Write for type&",
1663 if not Is_Elementary_Type (P_Type) then
1665 ("\which is a component of type&", N, P_Type);
1671 -- Check special case of Exception_Id and Exception_Occurrence which
1672 -- are not allowed for restriction No_Exception_Registration.
1674 if Restriction_Check_Required (No_Exception_Registration)
1675 and then (Is_RTE (P_Type, RE_Exception_Id)
1677 Is_RTE (P_Type, RE_Exception_Occurrence))
1679 Check_Restriction (No_Exception_Registration, P);
1682 -- Here we must check that the first argument is an access type
1683 -- that is compatible with Ada.Streams.Root_Stream_Type'Class.
1685 Analyze_And_Resolve (E1);
1688 -- Note: the double call to Root_Type here is needed because the
1689 -- root type of a class-wide type is the corresponding type (e.g.
1690 -- X for X'Class, and we really want to go to the root.)
1692 if not Is_Access_Type (Etyp)
1693 or else Root_Type (Root_Type (Designated_Type (Etyp))) /=
1694 RTE (RE_Root_Stream_Type)
1697 ("expected access to Ada.Streams.Root_Stream_Type''Class", E1);
1700 -- Check that the second argument is of the right type if there is
1701 -- one (the Input attribute has only one argument so this is skipped)
1703 if Present (E2) then
1706 if Nam = TSS_Stream_Read
1707 and then not Is_OK_Variable_For_Out_Formal (E2)
1710 ("second argument of % attribute must be a variable", E2);
1713 Resolve (E2, P_Type);
1717 end Check_Stream_Attribute;
1719 -----------------------
1720 -- Check_Task_Prefix --
1721 -----------------------
1723 procedure Check_Task_Prefix is
1727 -- Ada 2005 (AI-345): Attribute 'Terminated can be applied to
1728 -- task interface class-wide types.
1730 if Is_Task_Type (Etype (P))
1731 or else (Is_Access_Type (Etype (P))
1732 and then Is_Task_Type (Designated_Type (Etype (P))))
1733 or else (Ada_Version >= Ada_2005
1734 and then Ekind (Etype (P)) = E_Class_Wide_Type
1735 and then Is_Interface (Etype (P))
1736 and then Is_Task_Interface (Etype (P)))
1741 if Ada_Version >= Ada_2005 then
1743 ("prefix of % attribute must be a task or a task " &
1744 "interface class-wide object");
1747 Error_Attr_P ("prefix of % attribute must be a task");
1750 end Check_Task_Prefix;
1756 -- The possibilities are an entity name denoting a type, or an
1757 -- attribute reference that denotes a type (Base or Class). If
1758 -- the type is incomplete, replace it with its full view.
1760 procedure Check_Type is
1762 if not Is_Entity_Name (P)
1763 or else not Is_Type (Entity (P))
1765 Error_Attr_P ("prefix of % attribute must be a type");
1767 elsif Is_Protected_Self_Reference (P) then
1769 ("prefix of % attribute denotes current instance "
1770 & "(RM 9.4(21/2))");
1772 elsif Ekind (Entity (P)) = E_Incomplete_Type
1773 and then Present (Full_View (Entity (P)))
1775 P_Type := Full_View (Entity (P));
1776 Set_Entity (P, P_Type);
1780 ---------------------
1781 -- Check_Unit_Name --
1782 ---------------------
1784 procedure Check_Unit_Name (Nod : Node_Id) is
1786 if Nkind (Nod) = N_Identifier then
1789 elsif Nkind_In (Nod, N_Selected_Component, N_Expanded_Name) then
1790 Check_Unit_Name (Prefix (Nod));
1792 if Nkind (Selector_Name (Nod)) = N_Identifier then
1797 Error_Attr ("argument for % attribute must be unit name", P);
1798 end Check_Unit_Name;
1804 procedure Error_Attr is
1806 Set_Etype (N, Any_Type);
1807 Set_Entity (N, Any_Type);
1808 raise Bad_Attribute;
1811 procedure Error_Attr (Msg : String; Error_Node : Node_Id) is
1813 Error_Msg_Name_1 := Aname;
1814 Error_Msg_N (Msg, Error_Node);
1822 procedure Error_Attr_P (Msg : String) is
1824 Error_Msg_Name_1 := Aname;
1825 Error_Msg_F (Msg, P);
1829 ----------------------------
1830 -- Legal_Formal_Attribute --
1831 ----------------------------
1833 procedure Legal_Formal_Attribute is
1837 if not Is_Entity_Name (P)
1838 or else not Is_Type (Entity (P))
1840 Error_Attr_P ("prefix of % attribute must be generic type");
1842 elsif Is_Generic_Actual_Type (Entity (P))
1844 or else In_Inlined_Body
1848 elsif Is_Generic_Type (Entity (P)) then
1849 if not Is_Indefinite_Subtype (Entity (P)) then
1851 ("prefix of % attribute must be indefinite generic type");
1856 ("prefix of % attribute must be indefinite generic type");
1859 Set_Etype (N, Standard_Boolean);
1860 end Legal_Formal_Attribute;
1862 ------------------------
1863 -- Standard_Attribute --
1864 ------------------------
1866 procedure Standard_Attribute (Val : Int) is
1868 Check_Standard_Prefix;
1869 Rewrite (N, Make_Integer_Literal (Loc, Val));
1871 end Standard_Attribute;
1873 -------------------------
1874 -- Unexpected Argument --
1875 -------------------------
1877 procedure Unexpected_Argument (En : Node_Id) is
1879 Error_Attr ("unexpected argument for % attribute", En);
1880 end Unexpected_Argument;
1882 -------------------------------------------------
1883 -- Validate_Non_Static_Attribute_Function_Call --
1884 -------------------------------------------------
1886 -- This function should be moved to Sem_Dist ???
1888 procedure Validate_Non_Static_Attribute_Function_Call is
1890 if In_Preelaborated_Unit
1891 and then not In_Subprogram_Or_Concurrent_Unit
1893 Flag_Non_Static_Expr
1894 ("non-static function call in preelaborated unit!", N);
1896 end Validate_Non_Static_Attribute_Function_Call;
1898 -- Start of processing for Analyze_Attribute
1901 -- Immediate return if unrecognized attribute (already diagnosed
1902 -- by parser, so there is nothing more that we need to do)
1904 if not Is_Attribute_Name (Aname) then
1905 raise Bad_Attribute;
1908 -- Deal with Ada 83 issues
1910 if Comes_From_Source (N) then
1911 if not Attribute_83 (Attr_Id) then
1912 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1913 Error_Msg_Name_1 := Aname;
1914 Error_Msg_N ("(Ada 83) attribute% is not standard?", N);
1917 if Attribute_Impl_Def (Attr_Id) then
1918 Check_Restriction (No_Implementation_Attributes, N);
1923 -- Deal with Ada 2005 attributes that are
1925 if Attribute_05 (Attr_Id) and then Ada_Version < Ada_2005 then
1926 Check_Restriction (No_Implementation_Attributes, N);
1929 -- Remote access to subprogram type access attribute reference needs
1930 -- unanalyzed copy for tree transformation. The analyzed copy is used
1931 -- for its semantic information (whether prefix is a remote subprogram
1932 -- name), the unanalyzed copy is used to construct new subtree rooted
1933 -- with N_Aggregate which represents a fat pointer aggregate.
1935 if Aname = Name_Access then
1936 Discard_Node (Copy_Separate_Tree (N));
1939 -- Analyze prefix and exit if error in analysis. If the prefix is an
1940 -- incomplete type, use full view if available. Note that there are
1941 -- some attributes for which we do not analyze the prefix, since the
1942 -- prefix is not a normal name, or else needs special handling.
1944 if Aname /= Name_Elab_Body
1946 Aname /= Name_Elab_Spec
1948 Aname /= Name_Elab_Subp_Body
1950 Aname /= Name_UET_Address
1952 Aname /= Name_Enabled
1957 P_Type := Etype (P);
1959 if Is_Entity_Name (P)
1960 and then Present (Entity (P))
1961 and then Is_Type (Entity (P))
1963 if Ekind (Entity (P)) = E_Incomplete_Type then
1964 P_Type := Get_Full_View (P_Type);
1965 Set_Entity (P, P_Type);
1966 Set_Etype (P, P_Type);
1968 elsif Entity (P) = Current_Scope
1969 and then Is_Record_Type (Entity (P))
1971 -- Use of current instance within the type. Verify that if the
1972 -- attribute appears within a constraint, it yields an access
1973 -- type, other uses are illegal.
1981 and then Nkind (Parent (Par)) /= N_Component_Definition
1983 Par := Parent (Par);
1987 and then Nkind (Par) = N_Subtype_Indication
1989 if Attr_Id /= Attribute_Access
1990 and then Attr_Id /= Attribute_Unchecked_Access
1991 and then Attr_Id /= Attribute_Unrestricted_Access
1994 ("in a constraint the current instance can only"
1995 & " be used with an access attribute", N);
2002 if P_Type = Any_Type then
2003 raise Bad_Attribute;
2006 P_Base_Type := Base_Type (P_Type);
2009 -- Analyze expressions that may be present, exiting if an error occurs
2016 E1 := First (Exprs);
2019 -- Check for missing/bad expression (result of previous error)
2021 if No (E1) or else Etype (E1) = Any_Type then
2022 raise Bad_Attribute;
2027 if Present (E2) then
2030 if Etype (E2) = Any_Type then
2031 raise Bad_Attribute;
2034 if Present (Next (E2)) then
2035 Unexpected_Argument (Next (E2));
2040 -- Ada 2005 (AI-345): Ensure that the compiler gives exactly the current
2041 -- output compiling in Ada 95 mode for the case of ambiguous prefixes.
2043 if Ada_Version < Ada_2005
2044 and then Is_Overloaded (P)
2045 and then Aname /= Name_Access
2046 and then Aname /= Name_Address
2047 and then Aname /= Name_Code_Address
2048 and then Aname /= Name_Count
2049 and then Aname /= Name_Result
2050 and then Aname /= Name_Unchecked_Access
2052 Error_Attr ("ambiguous prefix for % attribute", P);
2054 elsif Ada_Version >= Ada_2005
2055 and then Is_Overloaded (P)
2056 and then Aname /= Name_Access
2057 and then Aname /= Name_Address
2058 and then Aname /= Name_Code_Address
2059 and then Aname /= Name_Result
2060 and then Aname /= Name_Unchecked_Access
2062 -- Ada 2005 (AI-345): Since protected and task types have primitive
2063 -- entry wrappers, the attributes Count, Caller and AST_Entry require
2066 if Ada_Version >= Ada_2005
2067 and then (Aname = Name_Count
2068 or else Aname = Name_Caller
2069 or else Aname = Name_AST_Entry)
2072 Count : Natural := 0;
2077 Get_First_Interp (P, I, It);
2078 while Present (It.Nam) loop
2079 if Comes_From_Source (It.Nam) then
2085 Get_Next_Interp (I, It);
2089 Error_Attr ("ambiguous prefix for % attribute", P);
2091 Set_Is_Overloaded (P, False);
2096 Error_Attr ("ambiguous prefix for % attribute", P);
2100 -- In SPARK, attributes of private types are only allowed if the full
2101 -- type declaration is visible.
2103 if Is_Entity_Name (P)
2104 and then Present (Entity (P)) -- needed in some cases
2105 and then Is_Type (Entity (P))
2106 and then Is_Private_Type (P_Type)
2107 and then not In_Open_Scopes (Scope (P_Type))
2108 and then not In_Spec_Expression
2110 Check_SPARK_Restriction ("invisible attribute of type", N);
2113 -- Remaining processing depends on attribute
2117 -- Attributes related to Ada2012 iterators. Attribute specifications
2118 -- exist for these, but they cannot be queried.
2120 when Attribute_Constant_Indexing |
2121 Attribute_Default_Iterator |
2122 Attribute_Implicit_Dereference |
2123 Attribute_Iterator_Element |
2124 Attribute_Variable_Indexing =>
2125 Error_Msg_N ("illegal attribute", N);
2131 when Attribute_Abort_Signal =>
2132 Check_Standard_Prefix;
2133 Rewrite (N, New_Reference_To (Stand.Abort_Signal, Loc));
2140 when Attribute_Access =>
2141 Analyze_Access_Attribute;
2147 when Attribute_Address =>
2150 -- Check for some junk cases, where we have to allow the address
2151 -- attribute but it does not make much sense, so at least for now
2152 -- just replace with Null_Address.
2154 -- We also do this if the prefix is a reference to the AST_Entry
2155 -- attribute. If expansion is active, the attribute will be
2156 -- replaced by a function call, and address will work fine and
2157 -- get the proper value, but if expansion is not active, then
2158 -- the check here allows proper semantic analysis of the reference.
2160 -- An Address attribute created by expansion is legal even when it
2161 -- applies to other entity-denoting expressions.
2163 if Is_Protected_Self_Reference (P) then
2165 -- Address attribute on a protected object self reference is legal
2169 elsif Is_Entity_Name (P) then
2171 Ent : constant Entity_Id := Entity (P);
2174 if Is_Subprogram (Ent) then
2175 Set_Address_Taken (Ent);
2176 Kill_Current_Values (Ent);
2178 -- An Address attribute is accepted when generated by the
2179 -- compiler for dispatching operation, and an error is
2180 -- issued once the subprogram is frozen (to avoid confusing
2181 -- errors about implicit uses of Address in the dispatch
2182 -- table initialization).
2184 if Has_Pragma_Inline_Always (Entity (P))
2185 and then Comes_From_Source (P)
2188 ("prefix of % attribute cannot be Inline_Always" &
2191 -- It is illegal to apply 'Address to an intrinsic
2192 -- subprogram. This is now formalized in AI05-0095.
2193 -- In an instance, an attempt to obtain 'Address of an
2194 -- intrinsic subprogram (e.g the renaming of a predefined
2195 -- operator that is an actual) raises Program_Error.
2197 elsif Convention (Ent) = Convention_Intrinsic then
2200 Make_Raise_Program_Error (Loc,
2201 Reason => PE_Address_Of_Intrinsic));
2205 ("cannot take Address of intrinsic subprogram", N);
2208 -- Issue an error if prefix denotes an eliminated subprogram
2211 Check_For_Eliminated_Subprogram (P, Ent);
2214 elsif Is_Object (Ent)
2215 or else Ekind (Ent) = E_Label
2217 Set_Address_Taken (Ent);
2219 -- If we have an address of an object, and the attribute
2220 -- comes from source, then set the object as potentially
2221 -- source modified. We do this because the resulting address
2222 -- can potentially be used to modify the variable and we
2223 -- might not detect this, leading to some junk warnings.
2225 Set_Never_Set_In_Source (Ent, False);
2227 elsif (Is_Concurrent_Type (Etype (Ent))
2228 and then Etype (Ent) = Base_Type (Ent))
2229 or else Ekind (Ent) = E_Package
2230 or else Is_Generic_Unit (Ent)
2233 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
2236 Error_Attr ("invalid prefix for % attribute", P);
2240 elsif Nkind (P) = N_Attribute_Reference
2241 and then Attribute_Name (P) = Name_AST_Entry
2244 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
2246 elsif Is_Object_Reference (P) then
2249 elsif Nkind (P) = N_Selected_Component
2250 and then Is_Subprogram (Entity (Selector_Name (P)))
2254 -- What exactly are we allowing here ??? and is this properly
2255 -- documented in the sinfo documentation for this node ???
2257 elsif not Comes_From_Source (N) then
2261 Error_Attr ("invalid prefix for % attribute", P);
2264 Set_Etype (N, RTE (RE_Address));
2270 when Attribute_Address_Size =>
2271 Standard_Attribute (System_Address_Size);
2277 when Attribute_Adjacent =>
2278 Check_Floating_Point_Type_2;
2279 Set_Etype (N, P_Base_Type);
2280 Resolve (E1, P_Base_Type);
2281 Resolve (E2, P_Base_Type);
2287 when Attribute_Aft =>
2288 Check_Fixed_Point_Type_0;
2289 Set_Etype (N, Universal_Integer);
2295 when Attribute_Alignment =>
2297 -- Don't we need more checking here, cf Size ???
2300 Check_Not_Incomplete_Type;
2302 Set_Etype (N, Universal_Integer);
2308 when Attribute_Asm_Input =>
2309 Check_Asm_Attribute;
2311 -- The back-end may need to take the address of E2
2313 if Is_Entity_Name (E2) then
2314 Set_Address_Taken (Entity (E2));
2317 Set_Etype (N, RTE (RE_Asm_Input_Operand));
2323 when Attribute_Asm_Output =>
2324 Check_Asm_Attribute;
2326 if Etype (E2) = Any_Type then
2329 elsif Aname = Name_Asm_Output then
2330 if not Is_Variable (E2) then
2332 ("second argument for Asm_Output is not variable", E2);
2336 Note_Possible_Modification (E2, Sure => True);
2338 -- The back-end may need to take the address of E2
2340 if Is_Entity_Name (E2) then
2341 Set_Address_Taken (Entity (E2));
2344 Set_Etype (N, RTE (RE_Asm_Output_Operand));
2350 when Attribute_AST_Entry => AST_Entry : declare
2356 -- Indicates if entry family index is present. Note the coding
2357 -- here handles the entry family case, but in fact it cannot be
2358 -- executed currently, because pragma AST_Entry does not permit
2359 -- the specification of an entry family.
2361 procedure Bad_AST_Entry;
2362 -- Signal a bad AST_Entry pragma
2364 function OK_Entry (E : Entity_Id) return Boolean;
2365 -- Checks that E is of an appropriate entity kind for an entry
2366 -- (i.e. E_Entry if Index is False, or E_Entry_Family if Index
2367 -- is set True for the entry family case). In the True case,
2368 -- makes sure that Is_AST_Entry is set on the entry.
2374 procedure Bad_AST_Entry is
2376 Error_Attr_P ("prefix for % attribute must be task entry");
2383 function OK_Entry (E : Entity_Id) return Boolean is
2388 Result := (Ekind (E) = E_Entry_Family);
2390 Result := (Ekind (E) = E_Entry);
2394 if not Is_AST_Entry (E) then
2395 Error_Msg_Name_2 := Aname;
2396 Error_Attr ("% attribute requires previous % pragma", P);
2403 -- Start of processing for AST_Entry
2409 -- Deal with entry family case
2411 if Nkind (P) = N_Indexed_Component then
2419 Ptyp := Etype (Pref);
2421 if Ptyp = Any_Type or else Error_Posted (Pref) then
2425 -- If the prefix is a selected component whose prefix is of an
2426 -- access type, then introduce an explicit dereference.
2427 -- ??? Could we reuse Check_Dereference here?
2429 if Nkind (Pref) = N_Selected_Component
2430 and then Is_Access_Type (Ptyp)
2433 Make_Explicit_Dereference (Sloc (Pref),
2434 Relocate_Node (Pref)));
2435 Analyze_And_Resolve (Pref, Designated_Type (Ptyp));
2438 -- Prefix can be of the form a.b, where a is a task object
2439 -- and b is one of the entries of the corresponding task type.
2441 if Nkind (Pref) = N_Selected_Component
2442 and then OK_Entry (Entity (Selector_Name (Pref)))
2443 and then Is_Object_Reference (Prefix (Pref))
2444 and then Is_Task_Type (Etype (Prefix (Pref)))
2448 -- Otherwise the prefix must be an entry of a containing task,
2449 -- or of a variable of the enclosing task type.
2452 if Nkind_In (Pref, N_Identifier, N_Expanded_Name) then
2453 Ent := Entity (Pref);
2455 if not OK_Entry (Ent)
2456 or else not In_Open_Scopes (Scope (Ent))
2466 Set_Etype (N, RTE (RE_AST_Handler));
2473 -- Note: when the base attribute appears in the context of a subtype
2474 -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by
2475 -- the following circuit.
2477 when Attribute_Base => Base : declare
2485 if Ada_Version >= Ada_95
2486 and then not Is_Scalar_Type (Typ)
2487 and then not Is_Generic_Type (Typ)
2489 Error_Attr_P ("prefix of Base attribute must be scalar type");
2491 elsif Sloc (Typ) = Standard_Location
2492 and then Base_Type (Typ) = Typ
2493 and then Warn_On_Redundant_Constructs
2495 Error_Msg_NE -- CODEFIX
2496 ("?redundant attribute, & is its own base type", N, Typ);
2499 if Nkind (Parent (N)) /= N_Attribute_Reference then
2500 Error_Msg_Name_1 := Aname;
2501 Check_SPARK_Restriction
2502 ("attribute% is only allowed as prefix of another attribute", P);
2505 Set_Etype (N, Base_Type (Entity (P)));
2506 Set_Entity (N, Base_Type (Entity (P)));
2507 Rewrite (N, New_Reference_To (Entity (N), Loc));
2515 when Attribute_Bit => Bit :
2519 if not Is_Object_Reference (P) then
2520 Error_Attr_P ("prefix for % attribute must be object");
2522 -- What about the access object cases ???
2528 Set_Etype (N, Universal_Integer);
2535 when Attribute_Bit_Order => Bit_Order :
2540 if not Is_Record_Type (P_Type) then
2541 Error_Attr_P ("prefix of % attribute must be record type");
2544 if Bytes_Big_Endian xor Reverse_Bit_Order (P_Type) then
2546 New_Occurrence_Of (RTE (RE_High_Order_First), Loc));
2549 New_Occurrence_Of (RTE (RE_Low_Order_First), Loc));
2552 Set_Etype (N, RTE (RE_Bit_Order));
2555 -- Reset incorrect indication of staticness
2557 Set_Is_Static_Expression (N, False);
2564 -- Note: in generated code, we can have a Bit_Position attribute
2565 -- applied to a (naked) record component (i.e. the prefix is an
2566 -- identifier that references an E_Component or E_Discriminant
2567 -- entity directly, and this is interpreted as expected by Gigi.
2568 -- The following code will not tolerate such usage, but when the
2569 -- expander creates this special case, it marks it as analyzed
2570 -- immediately and sets an appropriate type.
2572 when Attribute_Bit_Position =>
2573 if Comes_From_Source (N) then
2577 Set_Etype (N, Universal_Integer);
2583 when Attribute_Body_Version =>
2586 Set_Etype (N, RTE (RE_Version_String));
2592 when Attribute_Callable =>
2594 Set_Etype (N, Standard_Boolean);
2601 when Attribute_Caller => Caller : declare
2608 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
2611 if not Is_Entry (Ent) then
2612 Error_Attr ("invalid entry name", N);
2616 Error_Attr ("invalid entry name", N);
2620 for J in reverse 0 .. Scope_Stack.Last loop
2621 S := Scope_Stack.Table (J).Entity;
2623 if S = Scope (Ent) then
2624 Error_Attr ("Caller must appear in matching accept or body", N);
2630 Set_Etype (N, RTE (RO_AT_Task_Id));
2637 when Attribute_Ceiling =>
2638 Check_Floating_Point_Type_1;
2639 Set_Etype (N, P_Base_Type);
2640 Resolve (E1, P_Base_Type);
2646 when Attribute_Class =>
2647 Check_Restriction (No_Dispatch, N);
2651 -- Applying Class to untagged incomplete type is obsolescent in Ada
2652 -- 2005. Note that we can't test Is_Tagged_Type here on P_Type, since
2653 -- this flag gets set by Find_Type in this situation.
2655 if Restriction_Check_Required (No_Obsolescent_Features)
2656 and then Ada_Version >= Ada_2005
2657 and then Ekind (P_Type) = E_Incomplete_Type
2660 DN : constant Node_Id := Declaration_Node (P_Type);
2662 if Nkind (DN) = N_Incomplete_Type_Declaration
2663 and then not Tagged_Present (DN)
2665 Check_Restriction (No_Obsolescent_Features, P);
2674 when Attribute_Code_Address =>
2677 if Nkind (P) = N_Attribute_Reference
2678 and then (Attribute_Name (P) = Name_Elab_Body
2680 Attribute_Name (P) = Name_Elab_Spec)
2684 elsif not Is_Entity_Name (P)
2685 or else (Ekind (Entity (P)) /= E_Function
2687 Ekind (Entity (P)) /= E_Procedure)
2689 Error_Attr ("invalid prefix for % attribute", P);
2690 Set_Address_Taken (Entity (P));
2692 -- Issue an error if the prefix denotes an eliminated subprogram
2695 Check_For_Eliminated_Subprogram (P, Entity (P));
2698 Set_Etype (N, RTE (RE_Address));
2700 ----------------------
2701 -- Compiler_Version --
2702 ----------------------
2704 when Attribute_Compiler_Version =>
2706 Check_Standard_Prefix;
2707 Rewrite (N, Make_String_Literal (Loc, "GNAT " & Gnat_Version_String));
2708 Analyze_And_Resolve (N, Standard_String);
2710 --------------------
2711 -- Component_Size --
2712 --------------------
2714 when Attribute_Component_Size =>
2716 Set_Etype (N, Universal_Integer);
2718 -- Note: unlike other array attributes, unconstrained arrays are OK
2720 if Is_Array_Type (P_Type) and then not Is_Constrained (P_Type) then
2730 when Attribute_Compose =>
2731 Check_Floating_Point_Type_2;
2732 Set_Etype (N, P_Base_Type);
2733 Resolve (E1, P_Base_Type);
2734 Resolve (E2, Any_Integer);
2740 when Attribute_Constrained =>
2742 Set_Etype (N, Standard_Boolean);
2744 -- Case from RM J.4(2) of constrained applied to private type
2746 if Is_Entity_Name (P) and then Is_Type (Entity (P)) then
2747 Check_Restriction (No_Obsolescent_Features, P);
2749 if Warn_On_Obsolescent_Feature then
2751 ("constrained for private type is an " &
2752 "obsolescent feature (RM J.4)?", N);
2755 -- If we are within an instance, the attribute must be legal
2756 -- because it was valid in the generic unit. Ditto if this is
2757 -- an inlining of a function declared in an instance.
2760 or else In_Inlined_Body
2764 -- For sure OK if we have a real private type itself, but must
2765 -- be completed, cannot apply Constrained to incomplete type.
2767 elsif Is_Private_Type (Entity (P)) then
2769 -- Note: this is one of the Annex J features that does not
2770 -- generate a warning from -gnatwj, since in fact it seems
2771 -- very useful, and is used in the GNAT runtime.
2773 Check_Not_Incomplete_Type;
2777 -- Normal (non-obsolescent case) of application to object of
2778 -- a discriminated type.
2781 Check_Object_Reference (P);
2783 -- If N does not come from source, then we allow the
2784 -- the attribute prefix to be of a private type whose
2785 -- full type has discriminants. This occurs in cases
2786 -- involving expanded calls to stream attributes.
2788 if not Comes_From_Source (N) then
2789 P_Type := Underlying_Type (P_Type);
2792 -- Must have discriminants or be an access type designating
2793 -- a type with discriminants. If it is a classwide type is ???
2794 -- has unknown discriminants.
2796 if Has_Discriminants (P_Type)
2797 or else Has_Unknown_Discriminants (P_Type)
2799 (Is_Access_Type (P_Type)
2800 and then Has_Discriminants (Designated_Type (P_Type)))
2804 -- Also allow an object of a generic type if extensions allowed
2805 -- and allow this for any type at all.
2807 elsif (Is_Generic_Type (P_Type)
2808 or else Is_Generic_Actual_Type (P_Type))
2809 and then Extensions_Allowed
2815 -- Fall through if bad prefix
2818 ("prefix of % attribute must be object of discriminated type");
2824 when Attribute_Copy_Sign =>
2825 Check_Floating_Point_Type_2;
2826 Set_Etype (N, P_Base_Type);
2827 Resolve (E1, P_Base_Type);
2828 Resolve (E2, P_Base_Type);
2834 when Attribute_Count => Count :
2843 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
2846 if Ekind (Ent) /= E_Entry then
2847 Error_Attr ("invalid entry name", N);
2850 elsif Nkind (P) = N_Indexed_Component then
2851 if not Is_Entity_Name (Prefix (P))
2852 or else No (Entity (Prefix (P)))
2853 or else Ekind (Entity (Prefix (P))) /= E_Entry_Family
2855 if Nkind (Prefix (P)) = N_Selected_Component
2856 and then Present (Entity (Selector_Name (Prefix (P))))
2857 and then Ekind (Entity (Selector_Name (Prefix (P)))) =
2861 ("attribute % must apply to entry of current task", P);
2864 Error_Attr ("invalid entry family name", P);
2869 Ent := Entity (Prefix (P));
2872 elsif Nkind (P) = N_Selected_Component
2873 and then Present (Entity (Selector_Name (P)))
2874 and then Ekind (Entity (Selector_Name (P))) = E_Entry
2877 ("attribute % must apply to entry of current task", P);
2880 Error_Attr ("invalid entry name", N);
2884 for J in reverse 0 .. Scope_Stack.Last loop
2885 S := Scope_Stack.Table (J).Entity;
2887 if S = Scope (Ent) then
2888 if Nkind (P) = N_Expanded_Name then
2889 Tsk := Entity (Prefix (P));
2891 -- The prefix denotes either the task type, or else a
2892 -- single task whose task type is being analyzed.
2897 or else (not Is_Type (Tsk)
2898 and then Etype (Tsk) = S
2899 and then not (Comes_From_Source (S)))
2904 ("Attribute % must apply to entry of current task", N);
2910 elsif Ekind (Scope (Ent)) in Task_Kind
2912 not Ekind_In (S, E_Loop, E_Block, E_Entry, E_Entry_Family)
2914 Error_Attr ("Attribute % cannot appear in inner unit", N);
2916 elsif Ekind (Scope (Ent)) = E_Protected_Type
2917 and then not Has_Completion (Scope (Ent))
2919 Error_Attr ("attribute % can only be used inside body", N);
2923 if Is_Overloaded (P) then
2925 Index : Interp_Index;
2929 Get_First_Interp (P, Index, It);
2931 while Present (It.Nam) loop
2932 if It.Nam = Ent then
2935 -- Ada 2005 (AI-345): Do not consider primitive entry
2936 -- wrappers generated for task or protected types.
2938 elsif Ada_Version >= Ada_2005
2939 and then not Comes_From_Source (It.Nam)
2944 Error_Attr ("ambiguous entry name", N);
2947 Get_Next_Interp (Index, It);
2952 Set_Etype (N, Universal_Integer);
2955 -----------------------
2956 -- Default_Bit_Order --
2957 -----------------------
2959 when Attribute_Default_Bit_Order => Default_Bit_Order :
2961 Check_Standard_Prefix;
2963 if Bytes_Big_Endian then
2965 Make_Integer_Literal (Loc, False_Value));
2968 Make_Integer_Literal (Loc, True_Value));
2971 Set_Etype (N, Universal_Integer);
2972 Set_Is_Static_Expression (N);
2973 end Default_Bit_Order;
2979 when Attribute_Definite =>
2980 Legal_Formal_Attribute;
2986 when Attribute_Delta =>
2987 Check_Fixed_Point_Type_0;
2988 Set_Etype (N, Universal_Real);
2994 when Attribute_Denorm =>
2995 Check_Floating_Point_Type_0;
2996 Set_Etype (N, Standard_Boolean);
3002 when Attribute_Digits =>
3006 if not Is_Floating_Point_Type (P_Type)
3007 and then not Is_Decimal_Fixed_Point_Type (P_Type)
3010 ("prefix of % attribute must be float or decimal type");
3013 Set_Etype (N, Universal_Integer);
3019 -- Also handles processing for Elab_Spec and Elab_Subp_Body
3021 when Attribute_Elab_Body |
3022 Attribute_Elab_Spec |
3023 Attribute_Elab_Subp_Body =>
3026 Check_Unit_Name (P);
3027 Set_Etype (N, Standard_Void_Type);
3029 -- We have to manually call the expander in this case to get
3030 -- the necessary expansion (normally attributes that return
3031 -- entities are not expanded).
3039 -- Shares processing with Elab_Body
3045 when Attribute_Elaborated =>
3047 Check_Unit_Name (P);
3048 Set_Etype (N, Standard_Boolean);
3054 when Attribute_Emax =>
3055 Check_Floating_Point_Type_0;
3056 Set_Etype (N, Universal_Integer);
3062 when Attribute_Enabled =>
3063 Check_Either_E0_Or_E1;
3065 if Present (E1) then
3066 if not Is_Entity_Name (E1) or else No (Entity (E1)) then
3067 Error_Msg_N ("entity name expected for Enabled attribute", E1);
3072 if Nkind (P) /= N_Identifier then
3073 Error_Msg_N ("identifier expected (check name)", P);
3074 elsif Get_Check_Id (Chars (P)) = No_Check_Id then
3075 Error_Msg_N ("& is not a recognized check name", P);
3078 Set_Etype (N, Standard_Boolean);
3084 when Attribute_Enum_Rep => Enum_Rep : declare
3086 if Present (E1) then
3088 Check_Discrete_Type;
3089 Resolve (E1, P_Base_Type);
3092 if not Is_Entity_Name (P)
3093 or else (not Is_Object (Entity (P))
3095 Ekind (Entity (P)) /= E_Enumeration_Literal)
3098 ("prefix of % attribute must be " &
3099 "discrete type/object or enum literal");
3103 Set_Etype (N, Universal_Integer);
3110 when Attribute_Enum_Val => Enum_Val : begin
3114 if not Is_Enumeration_Type (P_Type) then
3115 Error_Attr_P ("prefix of % attribute must be enumeration type");
3118 -- If the enumeration type has a standard representation, the effect
3119 -- is the same as 'Val, so rewrite the attribute as a 'Val.
3121 if not Has_Non_Standard_Rep (P_Base_Type) then
3123 Make_Attribute_Reference (Loc,
3124 Prefix => Relocate_Node (Prefix (N)),
3125 Attribute_Name => Name_Val,
3126 Expressions => New_List (Relocate_Node (E1))));
3127 Analyze_And_Resolve (N, P_Base_Type);
3129 -- Non-standard representation case (enumeration with holes)
3133 Resolve (E1, Any_Integer);
3134 Set_Etype (N, P_Base_Type);
3142 when Attribute_Epsilon =>
3143 Check_Floating_Point_Type_0;
3144 Set_Etype (N, Universal_Real);
3150 when Attribute_Exponent =>
3151 Check_Floating_Point_Type_1;
3152 Set_Etype (N, Universal_Integer);
3153 Resolve (E1, P_Base_Type);
3159 when Attribute_External_Tag =>
3163 Set_Etype (N, Standard_String);
3165 if not Is_Tagged_Type (P_Type) then
3166 Error_Attr_P ("prefix of % attribute must be tagged");
3173 when Attribute_Fast_Math =>
3174 Check_Standard_Prefix;
3176 if Opt.Fast_Math then
3177 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
3179 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
3186 when Attribute_First =>
3187 Check_Array_Or_Scalar_Type;
3188 Bad_Attribute_For_Predicate;
3194 when Attribute_First_Bit =>
3196 Set_Etype (N, Universal_Integer);
3202 when Attribute_Fixed_Value =>
3204 Check_Fixed_Point_Type;
3205 Resolve (E1, Any_Integer);
3206 Set_Etype (N, P_Base_Type);
3212 when Attribute_Floor =>
3213 Check_Floating_Point_Type_1;
3214 Set_Etype (N, P_Base_Type);
3215 Resolve (E1, P_Base_Type);
3221 when Attribute_Fore =>
3222 Check_Fixed_Point_Type_0;
3223 Set_Etype (N, Universal_Integer);
3229 when Attribute_Fraction =>
3230 Check_Floating_Point_Type_1;
3231 Set_Etype (N, P_Base_Type);
3232 Resolve (E1, P_Base_Type);
3238 when Attribute_From_Any =>
3240 Check_PolyORB_Attribute;
3241 Set_Etype (N, P_Base_Type);
3243 -----------------------
3244 -- Has_Access_Values --
3245 -----------------------
3247 when Attribute_Has_Access_Values =>
3250 Set_Etype (N, Standard_Boolean);
3252 -----------------------
3253 -- Has_Tagged_Values --
3254 -----------------------
3256 when Attribute_Has_Tagged_Values =>
3259 Set_Etype (N, Standard_Boolean);
3261 -----------------------
3262 -- Has_Discriminants --
3263 -----------------------
3265 when Attribute_Has_Discriminants =>
3266 Legal_Formal_Attribute;
3272 when Attribute_Identity =>
3276 if Etype (P) = Standard_Exception_Type then
3277 Set_Etype (N, RTE (RE_Exception_Id));
3279 -- Ada 2005 (AI-345): Attribute 'Identity may be applied to
3280 -- task interface class-wide types.
3282 elsif Is_Task_Type (Etype (P))
3283 or else (Is_Access_Type (Etype (P))
3284 and then Is_Task_Type (Designated_Type (Etype (P))))
3285 or else (Ada_Version >= Ada_2005
3286 and then Ekind (Etype (P)) = E_Class_Wide_Type
3287 and then Is_Interface (Etype (P))
3288 and then Is_Task_Interface (Etype (P)))
3291 Set_Etype (N, RTE (RO_AT_Task_Id));
3294 if Ada_Version >= Ada_2005 then
3296 ("prefix of % attribute must be an exception, a " &
3297 "task or a task interface class-wide object");
3300 ("prefix of % attribute must be a task or an exception");
3308 when Attribute_Image => Image :
3310 Check_SPARK_Restriction_On_Attribute;
3312 Set_Etype (N, Standard_String);
3314 if Is_Real_Type (P_Type) then
3315 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3316 Error_Msg_Name_1 := Aname;
3318 ("(Ada 83) % attribute not allowed for real types", N);
3322 if Is_Enumeration_Type (P_Type) then
3323 Check_Restriction (No_Enumeration_Maps, N);
3327 Resolve (E1, P_Base_Type);
3329 Validate_Non_Static_Attribute_Function_Call;
3336 when Attribute_Img => Img :
3339 Set_Etype (N, Standard_String);
3341 if not Is_Scalar_Type (P_Type)
3342 or else (Is_Entity_Name (P) and then Is_Type (Entity (P)))
3345 ("prefix of % attribute must be scalar object name");
3355 when Attribute_Input =>
3357 Check_Stream_Attribute (TSS_Stream_Input);
3358 Set_Etype (N, P_Base_Type);
3364 when Attribute_Integer_Value =>
3367 Resolve (E1, Any_Fixed);
3369 -- Signal an error if argument type is not a specific fixed-point
3370 -- subtype. An error has been signalled already if the argument
3371 -- was not of a fixed-point type.
3373 if Etype (E1) = Any_Fixed and then not Error_Posted (E1) then
3374 Error_Attr ("argument of % must be of a fixed-point type", E1);
3377 Set_Etype (N, P_Base_Type);
3383 when Attribute_Invalid_Value =>
3386 Set_Etype (N, P_Base_Type);
3387 Invalid_Value_Used := True;
3393 when Attribute_Large =>
3396 Set_Etype (N, Universal_Real);
3402 when Attribute_Last =>
3403 Check_Array_Or_Scalar_Type;
3404 Bad_Attribute_For_Predicate;
3410 when Attribute_Last_Bit =>
3412 Set_Etype (N, Universal_Integer);
3418 when Attribute_Leading_Part =>
3419 Check_Floating_Point_Type_2;
3420 Set_Etype (N, P_Base_Type);
3421 Resolve (E1, P_Base_Type);
3422 Resolve (E2, Any_Integer);
3428 when Attribute_Length =>
3430 Set_Etype (N, Universal_Integer);
3436 when Attribute_Machine =>
3437 Check_Floating_Point_Type_1;
3438 Set_Etype (N, P_Base_Type);
3439 Resolve (E1, P_Base_Type);
3445 when Attribute_Machine_Emax =>
3446 Check_Floating_Point_Type_0;
3447 Set_Etype (N, Universal_Integer);
3453 when Attribute_Machine_Emin =>
3454 Check_Floating_Point_Type_0;
3455 Set_Etype (N, Universal_Integer);
3457 ----------------------
3458 -- Machine_Mantissa --
3459 ----------------------
3461 when Attribute_Machine_Mantissa =>
3462 Check_Floating_Point_Type_0;
3463 Set_Etype (N, Universal_Integer);
3465 -----------------------
3466 -- Machine_Overflows --
3467 -----------------------
3469 when Attribute_Machine_Overflows =>
3472 Set_Etype (N, Standard_Boolean);
3478 when Attribute_Machine_Radix =>
3481 Set_Etype (N, Universal_Integer);
3483 ----------------------
3484 -- Machine_Rounding --
3485 ----------------------
3487 when Attribute_Machine_Rounding =>
3488 Check_Floating_Point_Type_1;
3489 Set_Etype (N, P_Base_Type);
3490 Resolve (E1, P_Base_Type);
3492 --------------------
3493 -- Machine_Rounds --
3494 --------------------
3496 when Attribute_Machine_Rounds =>
3499 Set_Etype (N, Standard_Boolean);
3505 when Attribute_Machine_Size =>
3508 Check_Not_Incomplete_Type;
3509 Set_Etype (N, Universal_Integer);
3515 when Attribute_Mantissa =>
3518 Set_Etype (N, Universal_Integer);
3524 when Attribute_Max =>
3527 Resolve (E1, P_Base_Type);
3528 Resolve (E2, P_Base_Type);
3529 Set_Etype (N, P_Base_Type);
3531 ----------------------------------
3532 -- Max_Alignment_For_Allocation --
3533 -- Max_Size_In_Storage_Elements --
3534 ----------------------------------
3536 when Attribute_Max_Alignment_For_Allocation |
3537 Attribute_Max_Size_In_Storage_Elements =>
3540 Check_Not_Incomplete_Type;
3541 Set_Etype (N, Universal_Integer);
3543 -----------------------
3544 -- Maximum_Alignment --
3545 -----------------------
3547 when Attribute_Maximum_Alignment =>
3548 Standard_Attribute (Ttypes.Maximum_Alignment);
3550 --------------------
3551 -- Mechanism_Code --
3552 --------------------
3554 when Attribute_Mechanism_Code =>
3555 if not Is_Entity_Name (P)
3556 or else not Is_Subprogram (Entity (P))
3558 Error_Attr_P ("prefix of % attribute must be subprogram");
3561 Check_Either_E0_Or_E1;
3563 if Present (E1) then
3564 Resolve (E1, Any_Integer);
3565 Set_Etype (E1, Standard_Integer);
3567 if not Is_Static_Expression (E1) then
3568 Flag_Non_Static_Expr
3569 ("expression for parameter number must be static!", E1);
3572 elsif UI_To_Int (Intval (E1)) > Number_Formals (Entity (P))
3573 or else UI_To_Int (Intval (E1)) < 0
3575 Error_Attr ("invalid parameter number for % attribute", E1);
3579 Set_Etype (N, Universal_Integer);
3585 when Attribute_Min =>
3588 Resolve (E1, P_Base_Type);
3589 Resolve (E2, P_Base_Type);
3590 Set_Etype (N, P_Base_Type);
3596 when Attribute_Mod =>
3598 -- Note: this attribute is only allowed in Ada 2005 mode, but
3599 -- we do not need to test that here, since Mod is only recognized
3600 -- as an attribute name in Ada 2005 mode during the parse.
3603 Check_Modular_Integer_Type;
3604 Resolve (E1, Any_Integer);
3605 Set_Etype (N, P_Base_Type);
3611 when Attribute_Model =>
3612 Check_Floating_Point_Type_1;
3613 Set_Etype (N, P_Base_Type);
3614 Resolve (E1, P_Base_Type);
3620 when Attribute_Model_Emin =>
3621 Check_Floating_Point_Type_0;
3622 Set_Etype (N, Universal_Integer);
3628 when Attribute_Model_Epsilon =>
3629 Check_Floating_Point_Type_0;
3630 Set_Etype (N, Universal_Real);
3632 --------------------
3633 -- Model_Mantissa --
3634 --------------------
3636 when Attribute_Model_Mantissa =>
3637 Check_Floating_Point_Type_0;
3638 Set_Etype (N, Universal_Integer);
3644 when Attribute_Model_Small =>
3645 Check_Floating_Point_Type_0;
3646 Set_Etype (N, Universal_Real);
3652 when Attribute_Modulus =>
3654 Check_Modular_Integer_Type;
3655 Set_Etype (N, Universal_Integer);
3657 --------------------
3658 -- Null_Parameter --
3659 --------------------
3661 when Attribute_Null_Parameter => Null_Parameter : declare
3662 Parnt : constant Node_Id := Parent (N);
3663 GParnt : constant Node_Id := Parent (Parnt);
3665 procedure Bad_Null_Parameter (Msg : String);
3666 -- Used if bad Null parameter attribute node is found. Issues
3667 -- given error message, and also sets the type to Any_Type to
3668 -- avoid blowups later on from dealing with a junk node.
3670 procedure Must_Be_Imported (Proc_Ent : Entity_Id);
3671 -- Called to check that Proc_Ent is imported subprogram
3673 ------------------------
3674 -- Bad_Null_Parameter --
3675 ------------------------
3677 procedure Bad_Null_Parameter (Msg : String) is
3679 Error_Msg_N (Msg, N);
3680 Set_Etype (N, Any_Type);
3681 end Bad_Null_Parameter;
3683 ----------------------
3684 -- Must_Be_Imported --
3685 ----------------------
3687 procedure Must_Be_Imported (Proc_Ent : Entity_Id) is
3688 Pent : constant Entity_Id := Ultimate_Alias (Proc_Ent);
3691 -- Ignore check if procedure not frozen yet (we will get
3692 -- another chance when the default parameter is reanalyzed)
3694 if not Is_Frozen (Pent) then
3697 elsif not Is_Imported (Pent) then
3699 ("Null_Parameter can only be used with imported subprogram");
3704 end Must_Be_Imported;
3706 -- Start of processing for Null_Parameter
3711 Set_Etype (N, P_Type);
3713 -- Case of attribute used as default expression
3715 if Nkind (Parnt) = N_Parameter_Specification then
3716 Must_Be_Imported (Defining_Entity (GParnt));
3718 -- Case of attribute used as actual for subprogram (positional)
3720 elsif Nkind_In (Parnt, N_Procedure_Call_Statement,
3722 and then Is_Entity_Name (Name (Parnt))
3724 Must_Be_Imported (Entity (Name (Parnt)));
3726 -- Case of attribute used as actual for subprogram (named)
3728 elsif Nkind (Parnt) = N_Parameter_Association
3729 and then Nkind_In (GParnt, N_Procedure_Call_Statement,
3731 and then Is_Entity_Name (Name (GParnt))
3733 Must_Be_Imported (Entity (Name (GParnt)));
3735 -- Not an allowed case
3739 ("Null_Parameter must be actual or default parameter");
3747 when Attribute_Object_Size =>
3750 Check_Not_Incomplete_Type;
3751 Set_Etype (N, Universal_Integer);
3757 when Attribute_Old =>
3759 -- The attribute reference is a primary. If expressions follow, the
3760 -- attribute reference is an indexable object, so rewrite the node
3763 if Present (E1) then
3765 Make_Indexed_Component (Loc,
3767 Make_Attribute_Reference (Loc,
3768 Prefix => Relocate_Node (Prefix (N)),
3769 Attribute_Name => Name_Old),
3770 Expressions => Expressions (N)));
3778 -- Prefix has not been analyzed yet, and its full analysis will take
3779 -- place during expansion (see below).
3781 Preanalyze_And_Resolve (P);
3782 P_Type := Etype (P);
3783 Set_Etype (N, P_Type);
3785 if No (Current_Subprogram) then
3786 Error_Attr ("attribute % can only appear within subprogram", N);
3789 if Is_Limited_Type (P_Type) then
3790 Error_Attr ("attribute % cannot apply to limited objects", P);
3793 if Is_Entity_Name (P)
3794 and then Is_Constant_Object (Entity (P))
3797 ("?attribute Old applied to constant has no effect", P);
3800 -- Check that the expression does not refer to local entities
3802 Check_Local : declare
3803 Subp : Entity_Id := Current_Subprogram;
3805 function Process (N : Node_Id) return Traverse_Result;
3806 -- Check that N does not contain references to local variables or
3807 -- other local entities of Subp.
3813 function Process (N : Node_Id) return Traverse_Result is
3815 if Is_Entity_Name (N)
3816 and then Present (Entity (N))
3817 and then not Is_Formal (Entity (N))
3818 and then Enclosing_Subprogram (Entity (N)) = Subp
3820 Error_Msg_Node_1 := Entity (N);
3822 ("attribute % cannot refer to local variable&", N);
3828 procedure Check_No_Local is new Traverse_Proc;
3830 -- Start of processing for Check_Local
3835 if In_Parameter_Specification (P) then
3837 -- We have additional restrictions on using 'Old in parameter
3840 if Present (Enclosing_Subprogram (Current_Subprogram)) then
3842 -- Check that there is no reference to the enclosing
3843 -- subprogram local variables. Otherwise, we might end up
3844 -- being called from the enclosing subprogram and thus using
3845 -- 'Old on a local variable which is not defined at entry
3848 Subp := Enclosing_Subprogram (Current_Subprogram);
3852 -- We must prevent default expression of library-level
3853 -- subprogram from using 'Old, as the subprogram may be
3854 -- used in elaboration code for which there is no enclosing
3858 ("attribute % can only appear within subprogram", N);
3863 -- The attribute appears within a pre/postcondition, but refers to
3864 -- an entity in the enclosing subprogram. If it is a component of a
3865 -- formal its expansion might generate actual subtypes that may be
3866 -- referenced in an inner context, and which must be elaborated
3867 -- within the subprogram itself. As a result we create a declaration
3868 -- for it and insert it at the start of the enclosing subprogram
3869 -- This is properly an expansion activity but it has to be performed
3870 -- now to prevent out-of-order issues.
3872 if Nkind (P) = N_Selected_Component
3873 and then Has_Discriminants (Etype (Prefix (P)))
3875 P_Type := Base_Type (P_Type);
3876 Set_Etype (N, P_Type);
3877 Set_Etype (P, P_Type);
3881 ----------------------
3882 -- Overlaps_Storage --
3883 ----------------------
3885 when Attribute_Overlaps_Storage =>
3888 -- Both arguments must be objects of any type
3890 Analyze_And_Resolve (P);
3891 Analyze_And_Resolve (E1);
3892 Check_Object_Reference (P);
3893 Check_Object_Reference (E1);
3894 Set_Etype (N, Standard_Boolean);
3900 when Attribute_Output =>
3902 Check_Stream_Attribute (TSS_Stream_Output);
3903 Set_Etype (N, Standard_Void_Type);
3904 Resolve (N, Standard_Void_Type);
3910 when Attribute_Partition_ID => Partition_Id :
3914 if P_Type /= Any_Type then
3915 if not Is_Library_Level_Entity (Entity (P)) then
3917 ("prefix of % attribute must be library-level entity");
3919 -- The defining entity of prefix should not be declared inside a
3920 -- Pure unit. RM E.1(8). Is_Pure was set during declaration.
3922 elsif Is_Entity_Name (P)
3923 and then Is_Pure (Entity (P))
3925 Error_Attr_P ("prefix of% attribute must not be declared pure");
3929 Set_Etype (N, Universal_Integer);
3932 -------------------------
3933 -- Passed_By_Reference --
3934 -------------------------
3936 when Attribute_Passed_By_Reference =>
3939 Set_Etype (N, Standard_Boolean);
3945 when Attribute_Pool_Address =>
3947 Set_Etype (N, RTE (RE_Address));
3953 when Attribute_Pos =>
3954 Check_Discrete_Type;
3957 if Is_Boolean_Type (P_Type) then
3958 Error_Msg_Name_1 := Aname;
3959 Error_Msg_Name_2 := Chars (P_Type);
3960 Check_SPARK_Restriction
3961 ("attribute% is not allowed for type%", P);
3964 Resolve (E1, P_Base_Type);
3965 Set_Etype (N, Universal_Integer);
3971 when Attribute_Position =>
3973 Set_Etype (N, Universal_Integer);
3979 when Attribute_Pred =>
3983 if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then
3984 Error_Msg_Name_1 := Aname;
3985 Error_Msg_Name_2 := Chars (P_Type);
3986 Check_SPARK_Restriction
3987 ("attribute% is not allowed for type%", P);
3990 Resolve (E1, P_Base_Type);
3991 Set_Etype (N, P_Base_Type);
3993 -- Nothing to do for real type case
3995 if Is_Real_Type (P_Type) then
3998 -- If not modular type, test for overflow check required
4001 if not Is_Modular_Integer_Type (P_Type)
4002 and then not Range_Checks_Suppressed (P_Base_Type)
4004 Enable_Range_Check (E1);
4012 -- Ada 2005 (AI-327): Dynamic ceiling priorities
4014 when Attribute_Priority =>
4015 if Ada_Version < Ada_2005 then
4016 Error_Attr ("% attribute is allowed only in Ada 2005 mode", P);
4021 -- The prefix must be a protected object (AARM D.5.2 (2/2))
4025 if Is_Protected_Type (Etype (P))
4026 or else (Is_Access_Type (Etype (P))
4027 and then Is_Protected_Type (Designated_Type (Etype (P))))
4029 Resolve (P, Etype (P));
4031 Error_Attr_P ("prefix of % attribute must be a protected object");
4034 Set_Etype (N, Standard_Integer);
4036 -- Must be called from within a protected procedure or entry of the
4037 -- protected object.
4044 while S /= Etype (P)
4045 and then S /= Standard_Standard
4050 if S = Standard_Standard then
4051 Error_Attr ("the attribute % is only allowed inside protected "
4056 Validate_Non_Static_Attribute_Function_Call;
4062 when Attribute_Range =>
4063 Check_Array_Or_Scalar_Type;
4064 Bad_Attribute_For_Predicate;
4066 if Ada_Version = Ada_83
4067 and then Is_Scalar_Type (P_Type)
4068 and then Comes_From_Source (N)
4071 ("(Ada 83) % attribute not allowed for scalar type", P);
4078 when Attribute_Result => Result : declare
4080 -- The enclosing scope, excluding loops for quantified expressions
4083 -- During analysis, CS is the postcondition subprogram and PS the
4084 -- source subprogram to which the postcondition applies. During
4085 -- pre-analysis, CS is the scope of the subprogram declaration.
4088 -- During pre-analysis, Prag is the enclosing pragma node if any
4091 -- Find enclosing scopes, excluding loops
4093 CS := Current_Scope;
4094 while Ekind (CS) = E_Loop loop
4100 -- If the enclosing subprogram is always inlined, the enclosing
4101 -- postcondition will not be propagated to the expanded call.
4103 if not In_Spec_Expression
4104 and then Has_Pragma_Inline_Always (PS)
4105 and then Warn_On_Redundant_Constructs
4108 ("postconditions on inlined functions not enforced?", N);
4111 -- If we are in the scope of a function and in Spec_Expression mode,
4112 -- this is likely the prescan of the postcondition pragma, and we
4113 -- just set the proper type. If there is an error it will be caught
4114 -- when the real Analyze call is done.
4116 if Ekind (CS) = E_Function
4117 and then In_Spec_Expression
4121 if Chars (CS) /= Chars (P) then
4122 Error_Msg_Name_1 := Name_Result;
4125 ("incorrect prefix for % attribute, expected &", P, CS);
4129 -- Check in postcondition of function
4132 while not Nkind_In (Prag, N_Pragma,
4133 N_Function_Specification,
4136 Prag := Parent (Prag);
4139 if Nkind (Prag) /= N_Pragma then
4141 ("% attribute can only appear in postcondition of function",
4144 elsif Get_Pragma_Id (Prag) = Pragma_Test_Case then
4146 Arg_Ens : constant Node_Id :=
4147 Get_Ensures_From_Test_Case_Pragma (Prag);
4152 while Arg /= Prag and Arg /= Arg_Ens loop
4153 Arg := Parent (Arg);
4156 if Arg /= Arg_Ens then
4157 Error_Attr ("% attribute misplaced inside Test_Case", P);
4161 elsif Get_Pragma_Id (Prag) /= Pragma_Postcondition then
4163 ("% attribute can only appear in postcondition of function",
4167 -- The attribute reference is a primary. If expressions follow,
4168 -- the attribute reference is really an indexable object, so
4169 -- rewrite and analyze as an indexed component.
4171 if Present (E1) then
4173 Make_Indexed_Component (Loc,
4175 Make_Attribute_Reference (Loc,
4176 Prefix => Relocate_Node (Prefix (N)),
4177 Attribute_Name => Name_Result),
4178 Expressions => Expressions (N)));
4183 Set_Etype (N, Etype (CS));
4185 -- If several functions with that name are visible,
4186 -- the intended one is the current scope.
4188 if Is_Overloaded (P) then
4190 Set_Is_Overloaded (P, False);
4193 -- Body case, where we must be inside a generated _Postcondition
4194 -- procedure, and the prefix must be on the scope stack, or else
4195 -- the attribute use is definitely misplaced. The condition itself
4196 -- may have generated transient scopes, and is not necessarily the
4200 while Present (CS) and then CS /= Standard_Standard loop
4201 if Chars (CS) = Name_uPostconditions then
4210 if Chars (CS) = Name_uPostconditions
4211 and then Ekind (PS) = E_Function
4215 if Nkind_In (P, N_Identifier, N_Operator_Symbol)
4216 and then Chars (P) = Chars (PS)
4220 -- Within an instance, the prefix designates the local renaming
4221 -- of the original generic.
4223 elsif Is_Entity_Name (P)
4224 and then Ekind (Entity (P)) = E_Function
4225 and then Present (Alias (Entity (P)))
4226 and then Chars (Alias (Entity (P))) = Chars (PS)
4232 ("incorrect prefix for % attribute, expected &", P, PS);
4236 Rewrite (N, Make_Identifier (Sloc (N), Name_uResult));
4237 Analyze_And_Resolve (N, Etype (PS));
4241 ("% attribute can only appear in postcondition of function",
4251 when Attribute_Range_Length =>
4253 Check_Discrete_Type;
4254 Set_Etype (N, Universal_Integer);
4260 when Attribute_Read =>
4262 Check_Stream_Attribute (TSS_Stream_Read);
4263 Set_Etype (N, Standard_Void_Type);
4264 Resolve (N, Standard_Void_Type);
4265 Note_Possible_Modification (E2, Sure => True);
4271 when Attribute_Ref =>
4275 if Nkind (P) /= N_Expanded_Name
4276 or else not Is_RTE (P_Type, RE_Address)
4278 Error_Attr_P ("prefix of % attribute must be System.Address");
4281 Analyze_And_Resolve (E1, Any_Integer);
4282 Set_Etype (N, RTE (RE_Address));
4288 when Attribute_Remainder =>
4289 Check_Floating_Point_Type_2;
4290 Set_Etype (N, P_Base_Type);
4291 Resolve (E1, P_Base_Type);
4292 Resolve (E2, P_Base_Type);
4298 when Attribute_Round =>
4300 Check_Decimal_Fixed_Point_Type;
4301 Set_Etype (N, P_Base_Type);
4303 -- Because the context is universal_real (3.5.10(12)) it is a legal
4304 -- context for a universal fixed expression. This is the only
4305 -- attribute whose functional description involves U_R.
4307 if Etype (E1) = Universal_Fixed then
4309 Conv : constant Node_Id := Make_Type_Conversion (Loc,
4310 Subtype_Mark => New_Occurrence_Of (Universal_Real, Loc),
4311 Expression => Relocate_Node (E1));
4319 Resolve (E1, Any_Real);
4325 when Attribute_Rounding =>
4326 Check_Floating_Point_Type_1;
4327 Set_Etype (N, P_Base_Type);
4328 Resolve (E1, P_Base_Type);
4334 when Attribute_Safe_Emax =>
4335 Check_Floating_Point_Type_0;
4336 Set_Etype (N, Universal_Integer);
4342 when Attribute_Safe_First =>
4343 Check_Floating_Point_Type_0;
4344 Set_Etype (N, Universal_Real);
4350 when Attribute_Safe_Large =>
4353 Set_Etype (N, Universal_Real);
4359 when Attribute_Safe_Last =>
4360 Check_Floating_Point_Type_0;
4361 Set_Etype (N, Universal_Real);
4367 when Attribute_Safe_Small =>
4370 Set_Etype (N, Universal_Real);
4376 when Attribute_Same_Storage =>
4379 -- The arguments must be objects of any type
4381 Analyze_And_Resolve (P);
4382 Analyze_And_Resolve (E1);
4383 Check_Object_Reference (P);
4384 Check_Object_Reference (E1);
4385 Set_Etype (N, Standard_Boolean);
4391 when Attribute_Scale =>
4393 Check_Decimal_Fixed_Point_Type;
4394 Set_Etype (N, Universal_Integer);
4400 when Attribute_Scaling =>
4401 Check_Floating_Point_Type_2;
4402 Set_Etype (N, P_Base_Type);
4403 Resolve (E1, P_Base_Type);
4409 when Attribute_Signed_Zeros =>
4410 Check_Floating_Point_Type_0;
4411 Set_Etype (N, Standard_Boolean);
4417 when Attribute_Size | Attribute_VADS_Size => Size :
4421 -- If prefix is parameterless function call, rewrite and resolve
4424 if Is_Entity_Name (P)
4425 and then Ekind (Entity (P)) = E_Function
4429 -- Similar processing for a protected function call
4431 elsif Nkind (P) = N_Selected_Component
4432 and then Ekind (Entity (Selector_Name (P))) = E_Function
4437 if Is_Object_Reference (P) then
4438 Check_Object_Reference (P);
4440 elsif Is_Entity_Name (P)
4441 and then (Is_Type (Entity (P))
4442 or else Ekind (Entity (P)) = E_Enumeration_Literal)
4446 elsif Nkind (P) = N_Type_Conversion
4447 and then not Comes_From_Source (P)
4452 Error_Attr_P ("invalid prefix for % attribute");
4455 Check_Not_Incomplete_Type;
4457 Set_Etype (N, Universal_Integer);
4464 when Attribute_Small =>
4467 Set_Etype (N, Universal_Real);
4473 when Attribute_Storage_Pool => Storage_Pool :
4477 if Is_Access_Type (P_Type) then
4478 if Ekind (P_Type) = E_Access_Subprogram_Type then
4480 ("cannot use % attribute for access-to-subprogram type");
4483 -- Set appropriate entity
4485 if Present (Associated_Storage_Pool (Root_Type (P_Type))) then
4486 Set_Entity (N, Associated_Storage_Pool (Root_Type (P_Type)));
4488 Set_Entity (N, RTE (RE_Global_Pool_Object));
4491 Set_Etype (N, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
4493 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4494 -- Storage_Pool since this attribute is not defined for such
4495 -- types (RM E.2.3(22)).
4497 Validate_Remote_Access_To_Class_Wide_Type (N);
4500 Error_Attr_P ("prefix of % attribute must be access type");
4508 when Attribute_Storage_Size => Storage_Size :
4512 if Is_Task_Type (P_Type) then
4513 Set_Etype (N, Universal_Integer);
4515 -- Use with tasks is an obsolescent feature
4517 Check_Restriction (No_Obsolescent_Features, P);
4519 elsif Is_Access_Type (P_Type) then
4520 if Ekind (P_Type) = E_Access_Subprogram_Type then
4522 ("cannot use % attribute for access-to-subprogram type");
4525 if Is_Entity_Name (P)
4526 and then Is_Type (Entity (P))
4529 Set_Etype (N, Universal_Integer);
4531 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4532 -- Storage_Size since this attribute is not defined for
4533 -- such types (RM E.2.3(22)).
4535 Validate_Remote_Access_To_Class_Wide_Type (N);
4537 -- The prefix is allowed to be an implicit dereference
4538 -- of an access value designating a task.
4542 Set_Etype (N, Universal_Integer);
4546 Error_Attr_P ("prefix of % attribute must be access or task type");
4554 when Attribute_Storage_Unit =>
4555 Standard_Attribute (Ttypes.System_Storage_Unit);
4561 when Attribute_Stream_Size =>
4565 if Is_Entity_Name (P)
4566 and then Is_Elementary_Type (Entity (P))
4568 Set_Etype (N, Universal_Integer);
4570 Error_Attr_P ("invalid prefix for % attribute");
4577 when Attribute_Stub_Type =>
4581 if Is_Remote_Access_To_Class_Wide_Type (P_Type) then
4583 New_Occurrence_Of (Corresponding_Stub_Type (P_Type), Loc));
4586 ("prefix of% attribute must be remote access to classwide");
4593 when Attribute_Succ =>
4597 if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then
4598 Error_Msg_Name_1 := Aname;
4599 Error_Msg_Name_2 := Chars (P_Type);
4600 Check_SPARK_Restriction
4601 ("attribute% is not allowed for type%", P);
4604 Resolve (E1, P_Base_Type);
4605 Set_Etype (N, P_Base_Type);
4607 -- Nothing to do for real type case
4609 if Is_Real_Type (P_Type) then
4612 -- If not modular type, test for overflow check required
4615 if not Is_Modular_Integer_Type (P_Type)
4616 and then not Range_Checks_Suppressed (P_Base_Type)
4618 Enable_Range_Check (E1);
4622 --------------------------------
4623 -- System_Allocator_Alignment --
4624 --------------------------------
4626 when Attribute_System_Allocator_Alignment =>
4627 Standard_Attribute (Ttypes.System_Allocator_Alignment);
4633 when Attribute_Tag => Tag :
4638 if not Is_Tagged_Type (P_Type) then
4639 Error_Attr_P ("prefix of % attribute must be tagged");
4641 -- Next test does not apply to generated code
4642 -- why not, and what does the illegal reference mean???
4644 elsif Is_Object_Reference (P)
4645 and then not Is_Class_Wide_Type (P_Type)
4646 and then Comes_From_Source (N)
4649 ("% attribute can only be applied to objects " &
4650 "of class - wide type");
4653 -- The prefix cannot be an incomplete type. However, references
4654 -- to 'Tag can be generated when expanding interface conversions,
4655 -- and this is legal.
4657 if Comes_From_Source (N) then
4658 Check_Not_Incomplete_Type;
4661 -- Set appropriate type
4663 Set_Etype (N, RTE (RE_Tag));
4670 when Attribute_Target_Name => Target_Name : declare
4671 TN : constant String := Sdefault.Target_Name.all;
4675 Check_Standard_Prefix;
4679 if TN (TL) = '/' or else TN (TL) = '\' then
4684 Make_String_Literal (Loc,
4685 Strval => TN (TN'First .. TL)));
4686 Analyze_And_Resolve (N, Standard_String);
4693 when Attribute_Terminated =>
4695 Set_Etype (N, Standard_Boolean);
4702 when Attribute_To_Address =>
4706 if Nkind (P) /= N_Identifier
4707 or else Chars (P) /= Name_System
4709 Error_Attr_P ("prefix of % attribute must be System");
4712 Generate_Reference (RTE (RE_Address), P);
4713 Analyze_And_Resolve (E1, Any_Integer);
4714 Set_Etype (N, RTE (RE_Address));
4720 when Attribute_To_Any =>
4722 Check_PolyORB_Attribute;
4723 Set_Etype (N, RTE (RE_Any));
4729 when Attribute_Truncation =>
4730 Check_Floating_Point_Type_1;
4731 Resolve (E1, P_Base_Type);
4732 Set_Etype (N, P_Base_Type);
4738 when Attribute_Type_Class =>
4741 Check_Not_Incomplete_Type;
4742 Set_Etype (N, RTE (RE_Type_Class));
4748 when Attribute_TypeCode =>
4750 Check_PolyORB_Attribute;
4751 Set_Etype (N, RTE (RE_TypeCode));
4757 when Attribute_Type_Key =>
4761 -- This processing belongs in Eval_Attribute ???
4764 function Type_Key return String_Id;
4765 -- A very preliminary implementation. For now, a signature
4766 -- consists of only the type name. This is clearly incomplete
4767 -- (e.g., adding a new field to a record type should change the
4768 -- type's Type_Key attribute).
4774 function Type_Key return String_Id is
4775 Full_Name : constant String_Id :=
4776 Fully_Qualified_Name_String (Entity (P));
4779 -- Copy all characters in Full_Name but the trailing NUL
4782 for J in 1 .. String_Length (Full_Name) - 1 loop
4783 Store_String_Char (Get_String_Char (Full_Name, Int (J)));
4786 Store_String_Chars ("'Type_Key");
4791 Rewrite (N, Make_String_Literal (Loc, Type_Key));
4794 Analyze_And_Resolve (N, Standard_String);
4800 when Attribute_UET_Address =>
4802 Check_Unit_Name (P);
4803 Set_Etype (N, RTE (RE_Address));
4805 -----------------------
4806 -- Unbiased_Rounding --
4807 -----------------------
4809 when Attribute_Unbiased_Rounding =>
4810 Check_Floating_Point_Type_1;
4811 Set_Etype (N, P_Base_Type);
4812 Resolve (E1, P_Base_Type);
4814 ----------------------
4815 -- Unchecked_Access --
4816 ----------------------
4818 when Attribute_Unchecked_Access =>
4819 if Comes_From_Source (N) then
4820 Check_Restriction (No_Unchecked_Access, N);
4823 Analyze_Access_Attribute;
4825 -------------------------
4826 -- Unconstrained_Array --
4827 -------------------------
4829 when Attribute_Unconstrained_Array =>
4832 Check_Not_Incomplete_Type;
4833 Set_Etype (N, Standard_Boolean);
4835 ------------------------------
4836 -- Universal_Literal_String --
4837 ------------------------------
4839 -- This is a GNAT specific attribute whose prefix must be a named
4840 -- number where the expression is either a single numeric literal,
4841 -- or a numeric literal immediately preceded by a minus sign. The
4842 -- result is equivalent to a string literal containing the text of
4843 -- the literal as it appeared in the source program with a possible
4844 -- leading minus sign.
4846 when Attribute_Universal_Literal_String => Universal_Literal_String :
4850 if not Is_Entity_Name (P)
4851 or else Ekind (Entity (P)) not in Named_Kind
4853 Error_Attr_P ("prefix for % attribute must be named number");
4860 Src : Source_Buffer_Ptr;
4863 Expr := Original_Node (Expression (Parent (Entity (P))));
4865 if Nkind (Expr) = N_Op_Minus then
4867 Expr := Original_Node (Right_Opnd (Expr));
4872 if not Nkind_In (Expr, N_Integer_Literal, N_Real_Literal) then
4874 ("named number for % attribute must be simple literal", N);
4877 -- Build string literal corresponding to source literal text
4882 Store_String_Char (Get_Char_Code ('-'));
4886 Src := Source_Text (Get_Source_File_Index (S));
4888 while Src (S) /= ';' and then Src (S) /= ' ' loop
4889 Store_String_Char (Get_Char_Code (Src (S)));
4893 -- Now we rewrite the attribute with the string literal
4896 Make_String_Literal (Loc, End_String));
4900 end Universal_Literal_String;
4902 -------------------------
4903 -- Unrestricted_Access --
4904 -------------------------
4906 -- This is a GNAT specific attribute which is like Access except that
4907 -- all scope checks and checks for aliased views are omitted.
4909 when Attribute_Unrestricted_Access =>
4910 if Comes_From_Source (N) then
4911 Check_Restriction (No_Unchecked_Access, N);
4914 if Is_Entity_Name (P) then
4915 Set_Address_Taken (Entity (P));
4918 Analyze_Access_Attribute;
4924 when Attribute_Val => Val : declare
4927 Check_Discrete_Type;
4929 if Is_Boolean_Type (P_Type) then
4930 Error_Msg_Name_1 := Aname;
4931 Error_Msg_Name_2 := Chars (P_Type);
4932 Check_SPARK_Restriction
4933 ("attribute% is not allowed for type%", P);
4936 Resolve (E1, Any_Integer);
4937 Set_Etype (N, P_Base_Type);
4939 -- Note, we need a range check in general, but we wait for the
4940 -- Resolve call to do this, since we want to let Eval_Attribute
4941 -- have a chance to find an static illegality first!
4948 when Attribute_Valid =>
4951 -- Ignore check for object if we have a 'Valid reference generated
4952 -- by the expanded code, since in some cases valid checks can occur
4953 -- on items that are names, but are not objects (e.g. attributes).
4955 if Comes_From_Source (N) then
4956 Check_Object_Reference (P);
4959 if not Is_Scalar_Type (P_Type) then
4960 Error_Attr_P ("object for % attribute must be of scalar type");
4963 Set_Etype (N, Standard_Boolean);
4969 when Attribute_Value => Value :
4971 Check_SPARK_Restriction_On_Attribute;
4975 -- Case of enumeration type
4977 if Is_Enumeration_Type (P_Type) then
4978 Check_Restriction (No_Enumeration_Maps, N);
4980 -- Mark all enumeration literals as referenced, since the use of
4981 -- the Value attribute can implicitly reference any of the
4982 -- literals of the enumeration base type.
4985 Ent : Entity_Id := First_Literal (P_Base_Type);
4987 while Present (Ent) loop
4988 Set_Referenced (Ent);
4994 -- Set Etype before resolving expression because expansion of
4995 -- expression may require enclosing type. Note that the type
4996 -- returned by 'Value is the base type of the prefix type.
4998 Set_Etype (N, P_Base_Type);
4999 Validate_Non_Static_Attribute_Function_Call;
5006 when Attribute_Value_Size =>
5009 Check_Not_Incomplete_Type;
5010 Set_Etype (N, Universal_Integer);
5016 when Attribute_Version =>
5019 Set_Etype (N, RTE (RE_Version_String));
5025 when Attribute_Wchar_T_Size =>
5026 Standard_Attribute (Interfaces_Wchar_T_Size);
5032 when Attribute_Wide_Image => Wide_Image :
5034 Check_SPARK_Restriction_On_Attribute;
5036 Set_Etype (N, Standard_Wide_String);
5038 Resolve (E1, P_Base_Type);
5039 Validate_Non_Static_Attribute_Function_Call;
5042 ---------------------
5043 -- Wide_Wide_Image --
5044 ---------------------
5046 when Attribute_Wide_Wide_Image => Wide_Wide_Image :
5049 Set_Etype (N, Standard_Wide_Wide_String);
5051 Resolve (E1, P_Base_Type);
5052 Validate_Non_Static_Attribute_Function_Call;
5053 end Wide_Wide_Image;
5059 when Attribute_Wide_Value => Wide_Value :
5061 Check_SPARK_Restriction_On_Attribute;
5065 -- Set Etype before resolving expression because expansion
5066 -- of expression may require enclosing type.
5068 Set_Etype (N, P_Type);
5069 Validate_Non_Static_Attribute_Function_Call;
5072 ---------------------
5073 -- Wide_Wide_Value --
5074 ---------------------
5076 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
5081 -- Set Etype before resolving expression because expansion
5082 -- of expression may require enclosing type.
5084 Set_Etype (N, P_Type);
5085 Validate_Non_Static_Attribute_Function_Call;
5086 end Wide_Wide_Value;
5088 ---------------------
5089 -- Wide_Wide_Width --
5090 ---------------------
5092 when Attribute_Wide_Wide_Width =>
5095 Set_Etype (N, Universal_Integer);
5101 when Attribute_Wide_Width =>
5102 Check_SPARK_Restriction_On_Attribute;
5105 Set_Etype (N, Universal_Integer);
5111 when Attribute_Width =>
5112 Check_SPARK_Restriction_On_Attribute;
5115 Set_Etype (N, Universal_Integer);
5121 when Attribute_Word_Size =>
5122 Standard_Attribute (System_Word_Size);
5128 when Attribute_Write =>
5130 Check_Stream_Attribute (TSS_Stream_Write);
5131 Set_Etype (N, Standard_Void_Type);
5132 Resolve (N, Standard_Void_Type);
5136 -- All errors raise Bad_Attribute, so that we get out before any further
5137 -- damage occurs when an error is detected (for example, if we check for
5138 -- one attribute expression, and the check succeeds, we want to be able
5139 -- to proceed securely assuming that an expression is in fact present.
5141 -- Note: we set the attribute analyzed in this case to prevent any
5142 -- attempt at reanalysis which could generate spurious error msgs.
5145 when Bad_Attribute =>
5147 Set_Etype (N, Any_Type);
5149 end Analyze_Attribute;
5151 --------------------
5152 -- Eval_Attribute --
5153 --------------------
5155 procedure Eval_Attribute (N : Node_Id) is
5156 Loc : constant Source_Ptr := Sloc (N);
5157 Aname : constant Name_Id := Attribute_Name (N);
5158 Id : constant Attribute_Id := Get_Attribute_Id (Aname);
5159 P : constant Node_Id := Prefix (N);
5161 C_Type : constant Entity_Id := Etype (N);
5162 -- The type imposed by the context
5165 -- First expression, or Empty if none
5168 -- Second expression, or Empty if none
5170 P_Entity : Entity_Id;
5171 -- Entity denoted by prefix
5174 -- The type of the prefix
5176 P_Base_Type : Entity_Id;
5177 -- The base type of the prefix type
5179 P_Root_Type : Entity_Id;
5180 -- The root type of the prefix type
5183 -- True if the result is Static. This is set by the general processing
5184 -- to true if the prefix is static, and all expressions are static. It
5185 -- can be reset as processing continues for particular attributes
5187 Lo_Bound, Hi_Bound : Node_Id;
5188 -- Expressions for low and high bounds of type or array index referenced
5189 -- by First, Last, or Length attribute for array, set by Set_Bounds.
5192 -- Constraint error node used if we have an attribute reference has
5193 -- an argument that raises a constraint error. In this case we replace
5194 -- the attribute with a raise constraint_error node. This is important
5195 -- processing, since otherwise gigi might see an attribute which it is
5196 -- unprepared to deal with.
5198 procedure Check_Concurrent_Discriminant (Bound : Node_Id);
5199 -- If Bound is a reference to a discriminant of a task or protected type
5200 -- occurring within the object's body, rewrite attribute reference into
5201 -- a reference to the corresponding discriminal. Use for the expansion
5202 -- of checks against bounds of entry family index subtypes.
5204 procedure Check_Expressions;
5205 -- In case where the attribute is not foldable, the expressions, if
5206 -- any, of the attribute, are in a non-static context. This procedure
5207 -- performs the required additional checks.
5209 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean;
5210 -- Determines if the given type has compile time known bounds. Note
5211 -- that we enter the case statement even in cases where the prefix
5212 -- type does NOT have known bounds, so it is important to guard any
5213 -- attempt to evaluate both bounds with a call to this function.
5215 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint);
5216 -- This procedure is called when the attribute N has a non-static
5217 -- but compile time known value given by Val. It includes the
5218 -- necessary checks for out of range values.
5220 function Fore_Value return Nat;
5221 -- Computes the Fore value for the current attribute prefix, which is
5222 -- known to be a static fixed-point type. Used by Fore and Width.
5224 function Mantissa return Uint;
5225 -- Returns the Mantissa value for the prefix type
5227 procedure Set_Bounds;
5228 -- Used for First, Last and Length attributes applied to an array or
5229 -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low
5230 -- and high bound expressions for the index referenced by the attribute
5231 -- designator (i.e. the first index if no expression is present, and
5232 -- the N'th index if the value N is present as an expression). Also
5233 -- used for First and Last of scalar types. Static is reset to False
5234 -- if the type or index type is not statically constrained.
5236 function Statically_Denotes_Entity (N : Node_Id) return Boolean;
5237 -- Verify that the prefix of a potentially static array attribute
5238 -- satisfies the conditions of 4.9 (14).
5240 -----------------------------------
5241 -- Check_Concurrent_Discriminant --
5242 -----------------------------------
5244 procedure Check_Concurrent_Discriminant (Bound : Node_Id) is
5246 -- The concurrent (task or protected) type
5249 if Nkind (Bound) = N_Identifier
5250 and then Ekind (Entity (Bound)) = E_Discriminant
5251 and then Is_Concurrent_Record_Type (Scope (Entity (Bound)))
5253 Tsk := Corresponding_Concurrent_Type (Scope (Entity (Bound)));
5255 if In_Open_Scopes (Tsk) and then Has_Completion (Tsk) then
5257 -- Find discriminant of original concurrent type, and use
5258 -- its current discriminal, which is the renaming within
5259 -- the task/protected body.
5263 (Find_Body_Discriminal (Entity (Bound)), Loc));
5266 end Check_Concurrent_Discriminant;
5268 -----------------------
5269 -- Check_Expressions --
5270 -----------------------
5272 procedure Check_Expressions is
5276 while Present (E) loop
5277 Check_Non_Static_Context (E);
5280 end Check_Expressions;
5282 ----------------------------------
5283 -- Compile_Time_Known_Attribute --
5284 ----------------------------------
5286 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint) is
5287 T : constant Entity_Id := Etype (N);
5290 Fold_Uint (N, Val, False);
5292 -- Check that result is in bounds of the type if it is static
5294 if Is_In_Range (N, T, Assume_Valid => False) then
5297 elsif Is_Out_Of_Range (N, T) then
5298 Apply_Compile_Time_Constraint_Error
5299 (N, "value not in range of}?", CE_Range_Check_Failed);
5301 elsif not Range_Checks_Suppressed (T) then
5302 Enable_Range_Check (N);
5305 Set_Do_Range_Check (N, False);
5307 end Compile_Time_Known_Attribute;
5309 -------------------------------
5310 -- Compile_Time_Known_Bounds --
5311 -------------------------------
5313 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean is
5316 Compile_Time_Known_Value (Type_Low_Bound (Typ))
5318 Compile_Time_Known_Value (Type_High_Bound (Typ));
5319 end Compile_Time_Known_Bounds;
5325 -- Note that the Fore calculation is based on the actual values
5326 -- of the bounds, and does not take into account possible rounding.
5328 function Fore_Value return Nat is
5329 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
5330 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
5331 Small : constant Ureal := Small_Value (P_Type);
5332 Lo_Real : constant Ureal := Lo * Small;
5333 Hi_Real : constant Ureal := Hi * Small;
5338 -- Bounds are given in terms of small units, so first compute
5339 -- proper values as reals.
5341 T := UR_Max (abs Lo_Real, abs Hi_Real);
5344 -- Loop to compute proper value if more than one digit required
5346 while T >= Ureal_10 loop
5358 -- Table of mantissa values accessed by function Computed using
5361 -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1)
5363 -- where D is T'Digits (RM83 3.5.7)
5365 Mantissa_Value : constant array (Nat range 1 .. 40) of Nat := (
5407 function Mantissa return Uint is
5410 UI_From_Int (Mantissa_Value (UI_To_Int (Digits_Value (P_Type))));
5417 procedure Set_Bounds is
5423 -- For a string literal subtype, we have to construct the bounds.
5424 -- Valid Ada code never applies attributes to string literals, but
5425 -- it is convenient to allow the expander to generate attribute
5426 -- references of this type (e.g. First and Last applied to a string
5429 -- Note that the whole point of the E_String_Literal_Subtype is to
5430 -- avoid this construction of bounds, but the cases in which we
5431 -- have to materialize them are rare enough that we don't worry!
5433 -- The low bound is simply the low bound of the base type. The
5434 -- high bound is computed from the length of the string and this
5437 if Ekind (P_Type) = E_String_Literal_Subtype then
5438 Ityp := Etype (First_Index (Base_Type (P_Type)));
5439 Lo_Bound := Type_Low_Bound (Ityp);
5442 Make_Integer_Literal (Sloc (P),
5444 Expr_Value (Lo_Bound) + String_Literal_Length (P_Type) - 1);
5446 Set_Parent (Hi_Bound, P);
5447 Analyze_And_Resolve (Hi_Bound, Etype (Lo_Bound));
5450 -- For non-array case, just get bounds of scalar type
5452 elsif Is_Scalar_Type (P_Type) then
5455 -- For a fixed-point type, we must freeze to get the attributes
5456 -- of the fixed-point type set now so we can reference them.
5458 if Is_Fixed_Point_Type (P_Type)
5459 and then not Is_Frozen (Base_Type (P_Type))
5460 and then Compile_Time_Known_Value (Type_Low_Bound (P_Type))
5461 and then Compile_Time_Known_Value (Type_High_Bound (P_Type))
5463 Freeze_Fixed_Point_Type (Base_Type (P_Type));
5466 -- For array case, get type of proper index
5472 Ndim := UI_To_Int (Expr_Value (E1));
5475 Indx := First_Index (P_Type);
5476 for J in 1 .. Ndim - 1 loop
5480 -- If no index type, get out (some other error occurred, and
5481 -- we don't have enough information to complete the job!)
5489 Ityp := Etype (Indx);
5492 -- A discrete range in an index constraint is allowed to be a
5493 -- subtype indication. This is syntactically a pain, but should
5494 -- not propagate to the entity for the corresponding index subtype.
5495 -- After checking that the subtype indication is legal, the range
5496 -- of the subtype indication should be transfered to the entity.
5497 -- The attributes for the bounds should remain the simple retrievals
5498 -- that they are now.
5500 Lo_Bound := Type_Low_Bound (Ityp);
5501 Hi_Bound := Type_High_Bound (Ityp);
5503 if not Is_Static_Subtype (Ityp) then
5508 -------------------------------
5509 -- Statically_Denotes_Entity --
5510 -------------------------------
5512 function Statically_Denotes_Entity (N : Node_Id) return Boolean is
5516 if not Is_Entity_Name (N) then
5523 Nkind (Parent (E)) /= N_Object_Renaming_Declaration
5524 or else Statically_Denotes_Entity (Renamed_Object (E));
5525 end Statically_Denotes_Entity;
5527 -- Start of processing for Eval_Attribute
5530 -- No folding in spec expression that comes from source where the prefix
5531 -- is an unfrozen entity. This avoids premature folding in cases like:
5533 -- procedure DefExprAnal is
5534 -- type R is new Integer;
5535 -- procedure P (Arg : Integer := R'Size);
5536 -- for R'Size use 64;
5537 -- procedure P (Arg : Integer := R'Size) is
5539 -- Put_Line (Arg'Img);
5545 -- which should print 64 rather than 32. The exclusion of non-source
5546 -- constructs from this test comes from some internal usage in packed
5547 -- arrays, which otherwise fails, could use more analysis perhaps???
5549 -- We do however go ahead with generic actual types, otherwise we get
5550 -- some regressions, probably these types should be frozen anyway???
5552 if In_Spec_Expression
5553 and then Comes_From_Source (N)
5554 and then not (Is_Entity_Name (P)
5556 (Is_Frozen (Entity (P))
5557 or else (Is_Type (Entity (P))
5559 Is_Generic_Actual_Type (Entity (P)))))
5564 -- Acquire first two expressions (at the moment, no attributes take more
5565 -- than two expressions in any case).
5567 if Present (Expressions (N)) then
5568 E1 := First (Expressions (N));
5575 -- Special processing for Enabled attribute. This attribute has a very
5576 -- special prefix, and the easiest way to avoid lots of special checks
5577 -- to protect this special prefix from causing trouble is to deal with
5578 -- this attribute immediately and be done with it.
5580 if Id = Attribute_Enabled then
5582 -- We skip evaluation if the expander is not active. This is not just
5583 -- an optimization. It is of key importance that we not rewrite the
5584 -- attribute in a generic template, since we want to pick up the
5585 -- setting of the check in the instance, and testing expander active
5586 -- is as easy way of doing this as any.
5588 if Expander_Active then
5590 C : constant Check_Id := Get_Check_Id (Chars (P));
5595 if C in Predefined_Check_Id then
5596 R := Scope_Suppress (C);
5598 R := Is_Check_Suppressed (Empty, C);
5602 R := Is_Check_Suppressed (Entity (E1), C);
5606 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
5608 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
5616 -- Special processing for cases where the prefix is an object. For
5617 -- this purpose, a string literal counts as an object (attributes
5618 -- of string literals can only appear in generated code).
5620 if Is_Object_Reference (P) or else Nkind (P) = N_String_Literal then
5622 -- For Component_Size, the prefix is an array object, and we apply
5623 -- the attribute to the type of the object. This is allowed for
5624 -- both unconstrained and constrained arrays, since the bounds
5625 -- have no influence on the value of this attribute.
5627 if Id = Attribute_Component_Size then
5628 P_Entity := Etype (P);
5630 -- For First and Last, the prefix is an array object, and we apply
5631 -- the attribute to the type of the array, but we need a constrained
5632 -- type for this, so we use the actual subtype if available.
5634 elsif Id = Attribute_First
5638 Id = Attribute_Length
5641 AS : constant Entity_Id := Get_Actual_Subtype_If_Available (P);
5644 if Present (AS) and then Is_Constrained (AS) then
5647 -- If we have an unconstrained type we cannot fold
5655 -- For Size, give size of object if available, otherwise we
5656 -- cannot fold Size.
5658 elsif Id = Attribute_Size then
5659 if Is_Entity_Name (P)
5660 and then Known_Esize (Entity (P))
5662 Compile_Time_Known_Attribute (N, Esize (Entity (P)));
5670 -- For Alignment, give size of object if available, otherwise we
5671 -- cannot fold Alignment.
5673 elsif Id = Attribute_Alignment then
5674 if Is_Entity_Name (P)
5675 and then Known_Alignment (Entity (P))
5677 Fold_Uint (N, Alignment (Entity (P)), False);
5685 -- No other attributes for objects are folded
5692 -- Cases where P is not an object. Cannot do anything if P is
5693 -- not the name of an entity.
5695 elsif not Is_Entity_Name (P) then
5699 -- Otherwise get prefix entity
5702 P_Entity := Entity (P);
5705 -- At this stage P_Entity is the entity to which the attribute
5706 -- is to be applied. This is usually simply the entity of the
5707 -- prefix, except in some cases of attributes for objects, where
5708 -- as described above, we apply the attribute to the object type.
5710 -- First foldable possibility is a scalar or array type (RM 4.9(7))
5711 -- that is not generic (generic types are eliminated by RM 4.9(25)).
5712 -- Note we allow non-static non-generic types at this stage as further
5715 if Is_Type (P_Entity)
5716 and then (Is_Scalar_Type (P_Entity) or Is_Array_Type (P_Entity))
5717 and then (not Is_Generic_Type (P_Entity))
5721 -- Second foldable possibility is an array object (RM 4.9(8))
5723 elsif (Ekind (P_Entity) = E_Variable
5725 Ekind (P_Entity) = E_Constant)
5726 and then Is_Array_Type (Etype (P_Entity))
5727 and then (not Is_Generic_Type (Etype (P_Entity)))
5729 P_Type := Etype (P_Entity);
5731 -- If the entity is an array constant with an unconstrained nominal
5732 -- subtype then get the type from the initial value. If the value has
5733 -- been expanded into assignments, there is no expression and the
5734 -- attribute reference remains dynamic.
5736 -- We could do better here and retrieve the type ???
5738 if Ekind (P_Entity) = E_Constant
5739 and then not Is_Constrained (P_Type)
5741 if No (Constant_Value (P_Entity)) then
5744 P_Type := Etype (Constant_Value (P_Entity));
5748 -- Definite must be folded if the prefix is not a generic type,
5749 -- that is to say if we are within an instantiation. Same processing
5750 -- applies to the GNAT attributes Has_Discriminants, Type_Class,
5751 -- Has_Tagged_Value, and Unconstrained_Array.
5753 elsif (Id = Attribute_Definite
5755 Id = Attribute_Has_Access_Values
5757 Id = Attribute_Has_Discriminants
5759 Id = Attribute_Has_Tagged_Values
5761 Id = Attribute_Type_Class
5763 Id = Attribute_Unconstrained_Array
5765 Id = Attribute_Max_Alignment_For_Allocation)
5766 and then not Is_Generic_Type (P_Entity)
5770 -- We can fold 'Size applied to a type if the size is known (as happens
5771 -- for a size from an attribute definition clause). At this stage, this
5772 -- can happen only for types (e.g. record types) for which the size is
5773 -- always non-static. We exclude generic types from consideration (since
5774 -- they have bogus sizes set within templates).
5776 elsif Id = Attribute_Size
5777 and then Is_Type (P_Entity)
5778 and then (not Is_Generic_Type (P_Entity))
5779 and then Known_Static_RM_Size (P_Entity)
5781 Compile_Time_Known_Attribute (N, RM_Size (P_Entity));
5784 -- We can fold 'Alignment applied to a type if the alignment is known
5785 -- (as happens for an alignment from an attribute definition clause).
5786 -- At this stage, this can happen only for types (e.g. record
5787 -- types) for which the size is always non-static. We exclude
5788 -- generic types from consideration (since they have bogus
5789 -- sizes set within templates).
5791 elsif Id = Attribute_Alignment
5792 and then Is_Type (P_Entity)
5793 and then (not Is_Generic_Type (P_Entity))
5794 and then Known_Alignment (P_Entity)
5796 Compile_Time_Known_Attribute (N, Alignment (P_Entity));
5799 -- If this is an access attribute that is known to fail accessibility
5800 -- check, rewrite accordingly.
5802 elsif Attribute_Name (N) = Name_Access
5803 and then Raises_Constraint_Error (N)
5806 Make_Raise_Program_Error (Loc,
5807 Reason => PE_Accessibility_Check_Failed));
5808 Set_Etype (N, C_Type);
5811 -- No other cases are foldable (they certainly aren't static, and at
5812 -- the moment we don't try to fold any cases other than these three).
5819 -- If either attribute or the prefix is Any_Type, then propagate
5820 -- Any_Type to the result and don't do anything else at all.
5822 if P_Type = Any_Type
5823 or else (Present (E1) and then Etype (E1) = Any_Type)
5824 or else (Present (E2) and then Etype (E2) = Any_Type)
5826 Set_Etype (N, Any_Type);
5830 -- Scalar subtype case. We have not yet enforced the static requirement
5831 -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases
5832 -- of non-static attribute references (e.g. S'Digits for a non-static
5833 -- floating-point type, which we can compute at compile time).
5835 -- Note: this folding of non-static attributes is not simply a case of
5836 -- optimization. For many of the attributes affected, Gigi cannot handle
5837 -- the attribute and depends on the front end having folded them away.
5839 -- Note: although we don't require staticness at this stage, we do set
5840 -- the Static variable to record the staticness, for easy reference by
5841 -- those attributes where it matters (e.g. Succ and Pred), and also to
5842 -- be used to ensure that non-static folded things are not marked as
5843 -- being static (a check that is done right at the end).
5845 P_Root_Type := Root_Type (P_Type);
5846 P_Base_Type := Base_Type (P_Type);
5848 -- If the root type or base type is generic, then we cannot fold. This
5849 -- test is needed because subtypes of generic types are not always
5850 -- marked as being generic themselves (which seems odd???)
5852 if Is_Generic_Type (P_Root_Type)
5853 or else Is_Generic_Type (P_Base_Type)
5858 if Is_Scalar_Type (P_Type) then
5859 Static := Is_OK_Static_Subtype (P_Type);
5861 -- Array case. We enforce the constrained requirement of (RM 4.9(7-8))
5862 -- since we can't do anything with unconstrained arrays. In addition,
5863 -- only the First, Last and Length attributes are possibly static.
5865 -- Definite, Has_Access_Values, Has_Discriminants, Has_Tagged_Values,
5866 -- Type_Class, and Unconstrained_Array are again exceptions, because
5867 -- they apply as well to unconstrained types.
5869 -- In addition Component_Size is an exception since it is possibly
5870 -- foldable, even though it is never static, and it does apply to
5871 -- unconstrained arrays. Furthermore, it is essential to fold this
5872 -- in the packed case, since otherwise the value will be incorrect.
5874 elsif Id = Attribute_Definite
5876 Id = Attribute_Has_Access_Values
5878 Id = Attribute_Has_Discriminants
5880 Id = Attribute_Has_Tagged_Values
5882 Id = Attribute_Type_Class
5884 Id = Attribute_Unconstrained_Array
5886 Id = Attribute_Component_Size
5890 elsif Id /= Attribute_Max_Alignment_For_Allocation then
5891 if not Is_Constrained (P_Type)
5892 or else (Id /= Attribute_First and then
5893 Id /= Attribute_Last and then
5894 Id /= Attribute_Length)
5900 -- The rules in (RM 4.9(7,8)) require a static array, but as in the
5901 -- scalar case, we hold off on enforcing staticness, since there are
5902 -- cases which we can fold at compile time even though they are not
5903 -- static (e.g. 'Length applied to a static index, even though other
5904 -- non-static indexes make the array type non-static). This is only
5905 -- an optimization, but it falls out essentially free, so why not.
5906 -- Again we compute the variable Static for easy reference later
5907 -- (note that no array attributes are static in Ada 83).
5909 -- We also need to set Static properly for subsequent legality checks
5910 -- which might otherwise accept non-static constants in contexts
5911 -- where they are not legal.
5913 Static := Ada_Version >= Ada_95
5914 and then Statically_Denotes_Entity (P);
5920 N := First_Index (P_Type);
5922 -- The expression is static if the array type is constrained
5923 -- by given bounds, and not by an initial expression. Constant
5924 -- strings are static in any case.
5926 if Root_Type (P_Type) /= Standard_String then
5928 Static and then not Is_Constr_Subt_For_U_Nominal (P_Type);
5931 while Present (N) loop
5932 Static := Static and then Is_Static_Subtype (Etype (N));
5934 -- If however the index type is generic, or derived from
5935 -- one, attributes cannot be folded.
5937 if Is_Generic_Type (Root_Type (Etype (N)))
5938 and then Id /= Attribute_Component_Size
5948 -- Check any expressions that are present. Note that these expressions,
5949 -- depending on the particular attribute type, are either part of the
5950 -- attribute designator, or they are arguments in a case where the
5951 -- attribute reference returns a function. In the latter case, the
5952 -- rule in (RM 4.9(22)) applies and in particular requires the type
5953 -- of the expressions to be scalar in order for the attribute to be
5954 -- considered to be static.
5961 while Present (E) loop
5963 -- If expression is not static, then the attribute reference
5964 -- result certainly cannot be static.
5966 if not Is_Static_Expression (E) then
5970 -- If the result is not known at compile time, or is not of
5971 -- a scalar type, then the result is definitely not static,
5972 -- so we can quit now.
5974 if not Compile_Time_Known_Value (E)
5975 or else not Is_Scalar_Type (Etype (E))
5977 -- An odd special case, if this is a Pos attribute, this
5978 -- is where we need to apply a range check since it does
5979 -- not get done anywhere else.
5981 if Id = Attribute_Pos then
5982 if Is_Integer_Type (Etype (E)) then
5983 Apply_Range_Check (E, Etype (N));
5990 -- If the expression raises a constraint error, then so does
5991 -- the attribute reference. We keep going in this case because
5992 -- we are still interested in whether the attribute reference
5993 -- is static even if it is not static.
5995 elsif Raises_Constraint_Error (E) then
5996 Set_Raises_Constraint_Error (N);
6002 if Raises_Constraint_Error (Prefix (N)) then
6007 -- Deal with the case of a static attribute reference that raises
6008 -- constraint error. The Raises_Constraint_Error flag will already
6009 -- have been set, and the Static flag shows whether the attribute
6010 -- reference is static. In any case we certainly can't fold such an
6011 -- attribute reference.
6013 -- Note that the rewriting of the attribute node with the constraint
6014 -- error node is essential in this case, because otherwise Gigi might
6015 -- blow up on one of the attributes it never expects to see.
6017 -- The constraint_error node must have the type imposed by the context,
6018 -- to avoid spurious errors in the enclosing expression.
6020 if Raises_Constraint_Error (N) then
6022 Make_Raise_Constraint_Error (Sloc (N),
6023 Reason => CE_Range_Check_Failed);
6024 Set_Etype (CE_Node, Etype (N));
6025 Set_Raises_Constraint_Error (CE_Node);
6027 Rewrite (N, Relocate_Node (CE_Node));
6028 Set_Is_Static_Expression (N, Static);
6032 -- At this point we have a potentially foldable attribute reference.
6033 -- If Static is set, then the attribute reference definitely obeys
6034 -- the requirements in (RM 4.9(7,8,22)), and it definitely can be
6035 -- folded. If Static is not set, then the attribute may or may not
6036 -- be foldable, and the individual attribute processing routines
6037 -- test Static as required in cases where it makes a difference.
6039 -- In the case where Static is not set, we do know that all the
6040 -- expressions present are at least known at compile time (we assumed
6041 -- above that if this was not the case, then there was no hope of static
6042 -- evaluation). However, we did not require that the bounds of the
6043 -- prefix type be compile time known, let alone static). That's because
6044 -- there are many attributes that can be computed at compile time on
6045 -- non-static subtypes, even though such references are not static
6050 -- Attributes related to Ada2012 iterators (placeholder ???)
6052 when Attribute_Constant_Indexing => null;
6053 when Attribute_Default_Iterator => null;
6054 when Attribute_Implicit_Dereference => null;
6055 when Attribute_Iterator_Element => null;
6056 when Attribute_Variable_Indexing => null;
6062 when Attribute_Adjacent =>
6065 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6071 when Attribute_Aft =>
6072 Fold_Uint (N, Aft_Value (P_Type), True);
6078 when Attribute_Alignment => Alignment_Block : declare
6079 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6082 -- Fold if alignment is set and not otherwise
6084 if Known_Alignment (P_TypeA) then
6085 Fold_Uint (N, Alignment (P_TypeA), Is_Discrete_Type (P_TypeA));
6087 end Alignment_Block;
6093 -- Can only be folded in No_Ast_Handler case
6095 when Attribute_AST_Entry =>
6096 if not Is_AST_Entry (P_Entity) then
6098 New_Occurrence_Of (RTE (RE_No_AST_Handler), Loc));
6107 -- Bit can never be folded
6109 when Attribute_Bit =>
6116 -- Body_version can never be static
6118 when Attribute_Body_Version =>
6125 when Attribute_Ceiling =>
6127 Eval_Fat.Ceiling (P_Root_Type, Expr_Value_R (E1)), Static);
6129 --------------------
6130 -- Component_Size --
6131 --------------------
6133 when Attribute_Component_Size =>
6134 if Known_Static_Component_Size (P_Type) then
6135 Fold_Uint (N, Component_Size (P_Type), False);
6142 when Attribute_Compose =>
6145 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)),
6152 -- Constrained is never folded for now, there may be cases that
6153 -- could be handled at compile time. To be looked at later.
6155 when Attribute_Constrained =>
6162 when Attribute_Copy_Sign =>
6165 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6171 when Attribute_Definite =>
6172 Rewrite (N, New_Occurrence_Of (
6173 Boolean_Literals (not Is_Indefinite_Subtype (P_Entity)), Loc));
6174 Analyze_And_Resolve (N, Standard_Boolean);
6180 when Attribute_Delta =>
6181 Fold_Ureal (N, Delta_Value (P_Type), True);
6187 when Attribute_Denorm =>
6189 (N, UI_From_Int (Boolean'Pos (Denorm_On_Target)), True);
6195 when Attribute_Digits =>
6196 Fold_Uint (N, Digits_Value (P_Type), True);
6202 when Attribute_Emax =>
6204 -- Ada 83 attribute is defined as (RM83 3.5.8)
6206 -- T'Emax = 4 * T'Mantissa
6208 Fold_Uint (N, 4 * Mantissa, True);
6214 when Attribute_Enum_Rep =>
6216 -- For an enumeration type with a non-standard representation use
6217 -- the Enumeration_Rep field of the proper constant. Note that this
6218 -- will not work for types Character/Wide_[Wide-]Character, since no
6219 -- real entities are created for the enumeration literals, but that
6220 -- does not matter since these two types do not have non-standard
6221 -- representations anyway.
6223 if Is_Enumeration_Type (P_Type)
6224 and then Has_Non_Standard_Rep (P_Type)
6226 Fold_Uint (N, Enumeration_Rep (Expr_Value_E (E1)), Static);
6228 -- For enumeration types with standard representations and all
6229 -- other cases (i.e. all integer and modular types), Enum_Rep
6230 -- is equivalent to Pos.
6233 Fold_Uint (N, Expr_Value (E1), Static);
6240 when Attribute_Enum_Val => Enum_Val : declare
6244 -- We have something like Enum_Type'Enum_Val (23), so search for a
6245 -- corresponding value in the list of Enum_Rep values for the type.
6247 Lit := First_Literal (P_Base_Type);
6249 if Enumeration_Rep (Lit) = Expr_Value (E1) then
6250 Fold_Uint (N, Enumeration_Pos (Lit), Static);
6257 Apply_Compile_Time_Constraint_Error
6258 (N, "no representation value matches",
6259 CE_Range_Check_Failed,
6260 Warn => not Static);
6270 when Attribute_Epsilon =>
6272 -- Ada 83 attribute is defined as (RM83 3.5.8)
6274 -- T'Epsilon = 2.0**(1 - T'Mantissa)
6276 Fold_Ureal (N, Ureal_2 ** (1 - Mantissa), True);
6282 when Attribute_Exponent =>
6284 Eval_Fat.Exponent (P_Root_Type, Expr_Value_R (E1)), Static);
6290 when Attribute_First => First_Attr :
6294 if Compile_Time_Known_Value (Lo_Bound) then
6295 if Is_Real_Type (P_Type) then
6296 Fold_Ureal (N, Expr_Value_R (Lo_Bound), Static);
6298 Fold_Uint (N, Expr_Value (Lo_Bound), Static);
6302 Check_Concurrent_Discriminant (Lo_Bound);
6310 when Attribute_Fixed_Value =>
6317 when Attribute_Floor =>
6319 Eval_Fat.Floor (P_Root_Type, Expr_Value_R (E1)), Static);
6325 when Attribute_Fore =>
6326 if Compile_Time_Known_Bounds (P_Type) then
6327 Fold_Uint (N, UI_From_Int (Fore_Value), Static);
6334 when Attribute_Fraction =>
6336 Eval_Fat.Fraction (P_Root_Type, Expr_Value_R (E1)), Static);
6338 -----------------------
6339 -- Has_Access_Values --
6340 -----------------------
6342 when Attribute_Has_Access_Values =>
6343 Rewrite (N, New_Occurrence_Of
6344 (Boolean_Literals (Has_Access_Values (P_Root_Type)), Loc));
6345 Analyze_And_Resolve (N, Standard_Boolean);
6347 -----------------------
6348 -- Has_Discriminants --
6349 -----------------------
6351 when Attribute_Has_Discriminants =>
6352 Rewrite (N, New_Occurrence_Of (
6353 Boolean_Literals (Has_Discriminants (P_Entity)), Loc));
6354 Analyze_And_Resolve (N, Standard_Boolean);
6356 -----------------------
6357 -- Has_Tagged_Values --
6358 -----------------------
6360 when Attribute_Has_Tagged_Values =>
6361 Rewrite (N, New_Occurrence_Of
6362 (Boolean_Literals (Has_Tagged_Component (P_Root_Type)), Loc));
6363 Analyze_And_Resolve (N, Standard_Boolean);
6369 when Attribute_Identity =>
6376 -- Image is a scalar attribute, but is never static, because it is
6377 -- not a static function (having a non-scalar argument (RM 4.9(22))
6378 -- However, we can constant-fold the image of an enumeration literal
6379 -- if names are available.
6381 when Attribute_Image =>
6382 if Is_Entity_Name (E1)
6383 and then Ekind (Entity (E1)) = E_Enumeration_Literal
6384 and then not Discard_Names (First_Subtype (Etype (E1)))
6385 and then not Global_Discard_Names
6388 Lit : constant Entity_Id := Entity (E1);
6392 Get_Unqualified_Decoded_Name_String (Chars (Lit));
6393 Set_Casing (All_Upper_Case);
6394 Store_String_Chars (Name_Buffer (1 .. Name_Len));
6396 Rewrite (N, Make_String_Literal (Loc, Strval => Str));
6397 Analyze_And_Resolve (N, Standard_String);
6398 Set_Is_Static_Expression (N, False);
6406 -- Img is a scalar attribute, but is never static, because it is
6407 -- not a static function (having a non-scalar argument (RM 4.9(22))
6409 when Attribute_Img =>
6416 -- We never try to fold Integer_Value (though perhaps we could???)
6418 when Attribute_Integer_Value =>
6425 -- Invalid_Value is a scalar attribute that is never static, because
6426 -- the value is by design out of range.
6428 when Attribute_Invalid_Value =>
6435 when Attribute_Large =>
6437 -- For fixed-point, we use the identity:
6439 -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small
6441 if Is_Fixed_Point_Type (P_Type) then
6443 Make_Op_Multiply (Loc,
6445 Make_Op_Subtract (Loc,
6449 Make_Real_Literal (Loc, Ureal_2),
6451 Make_Attribute_Reference (Loc,
6453 Attribute_Name => Name_Mantissa)),
6454 Right_Opnd => Make_Real_Literal (Loc, Ureal_1)),
6457 Make_Real_Literal (Loc, Small_Value (Entity (P)))));
6459 Analyze_And_Resolve (N, C_Type);
6461 -- Floating-point (Ada 83 compatibility)
6464 -- Ada 83 attribute is defined as (RM83 3.5.8)
6466 -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa))
6470 -- T'Emax = 4 * T'Mantissa
6473 Ureal_2 ** (4 * Mantissa) * (Ureal_1 - Ureal_2 ** (-Mantissa)),
6481 when Attribute_Last => Last :
6485 if Compile_Time_Known_Value (Hi_Bound) then
6486 if Is_Real_Type (P_Type) then
6487 Fold_Ureal (N, Expr_Value_R (Hi_Bound), Static);
6489 Fold_Uint (N, Expr_Value (Hi_Bound), Static);
6493 Check_Concurrent_Discriminant (Hi_Bound);
6501 when Attribute_Leading_Part =>
6503 Eval_Fat.Leading_Part
6504 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
6510 when Attribute_Length => Length : declare
6514 -- If any index type is a formal type, or derived from one, the
6515 -- bounds are not static. Treating them as static can produce
6516 -- spurious warnings or improper constant folding.
6518 Ind := First_Index (P_Type);
6519 while Present (Ind) loop
6520 if Is_Generic_Type (Root_Type (Etype (Ind))) then
6529 -- For two compile time values, we can compute length
6531 if Compile_Time_Known_Value (Lo_Bound)
6532 and then Compile_Time_Known_Value (Hi_Bound)
6535 UI_Max (0, 1 + (Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound))),
6539 -- One more case is where Hi_Bound and Lo_Bound are compile-time
6540 -- comparable, and we can figure out the difference between them.
6543 Diff : aliased Uint;
6547 Compile_Time_Compare
6548 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
6551 Fold_Uint (N, Uint_1, False);
6554 Fold_Uint (N, Uint_0, False);
6557 if Diff /= No_Uint then
6558 Fold_Uint (N, Diff + 1, False);
6571 when Attribute_Machine =>
6574 (P_Root_Type, Expr_Value_R (E1), Eval_Fat.Round, N),
6581 when Attribute_Machine_Emax =>
6582 Fold_Uint (N, Machine_Emax_Value (P_Type), Static);
6588 when Attribute_Machine_Emin =>
6589 Fold_Uint (N, Machine_Emin_Value (P_Type), Static);
6591 ----------------------
6592 -- Machine_Mantissa --
6593 ----------------------
6595 when Attribute_Machine_Mantissa =>
6596 Fold_Uint (N, Machine_Mantissa_Value (P_Type), Static);
6598 -----------------------
6599 -- Machine_Overflows --
6600 -----------------------
6602 when Attribute_Machine_Overflows =>
6604 -- Always true for fixed-point
6606 if Is_Fixed_Point_Type (P_Type) then
6607 Fold_Uint (N, True_Value, True);
6609 -- Floating point case
6613 UI_From_Int (Boolean'Pos (Machine_Overflows_On_Target)),
6621 when Attribute_Machine_Radix =>
6622 if Is_Fixed_Point_Type (P_Type) then
6623 if Is_Decimal_Fixed_Point_Type (P_Type)
6624 and then Machine_Radix_10 (P_Type)
6626 Fold_Uint (N, Uint_10, True);
6628 Fold_Uint (N, Uint_2, True);
6631 -- All floating-point type always have radix 2
6634 Fold_Uint (N, Uint_2, True);
6637 ----------------------
6638 -- Machine_Rounding --
6639 ----------------------
6641 -- Note: for the folding case, it is fine to treat Machine_Rounding
6642 -- exactly the same way as Rounding, since this is one of the allowed
6643 -- behaviors, and performance is not an issue here. It might be a bit
6644 -- better to give the same result as it would give at run time, even
6645 -- though the non-determinism is certainly permitted.
6647 when Attribute_Machine_Rounding =>
6649 Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static);
6651 --------------------
6652 -- Machine_Rounds --
6653 --------------------
6655 when Attribute_Machine_Rounds =>
6657 -- Always False for fixed-point
6659 if Is_Fixed_Point_Type (P_Type) then
6660 Fold_Uint (N, False_Value, True);
6662 -- Else yield proper floating-point result
6666 (N, UI_From_Int (Boolean'Pos (Machine_Rounds_On_Target)), True);
6673 -- Note: Machine_Size is identical to Object_Size
6675 when Attribute_Machine_Size => Machine_Size : declare
6676 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6679 if Known_Esize (P_TypeA) then
6680 Fold_Uint (N, Esize (P_TypeA), True);
6688 when Attribute_Mantissa =>
6690 -- Fixed-point mantissa
6692 if Is_Fixed_Point_Type (P_Type) then
6694 -- Compile time foldable case
6696 if Compile_Time_Known_Value (Type_Low_Bound (P_Type))
6698 Compile_Time_Known_Value (Type_High_Bound (P_Type))
6700 -- The calculation of the obsolete Ada 83 attribute Mantissa
6701 -- is annoying, because of AI00143, quoted here:
6703 -- !question 84-01-10
6705 -- Consider the model numbers for F:
6707 -- type F is delta 1.0 range -7.0 .. 8.0;
6709 -- The wording requires that F'MANTISSA be the SMALLEST
6710 -- integer number for which each bound of the specified
6711 -- range is either a model number or lies at most small
6712 -- distant from a model number. This means F'MANTISSA
6713 -- is required to be 3 since the range -7.0 .. 7.0 fits
6714 -- in 3 signed bits, and 8 is "at most" 1.0 from a model
6715 -- number, namely, 7. Is this analysis correct? Note that
6716 -- this implies the upper bound of the range is not
6717 -- represented as a model number.
6719 -- !response 84-03-17
6721 -- The analysis is correct. The upper and lower bounds for
6722 -- a fixed point type can lie outside the range of model
6733 LBound := Expr_Value_R (Type_Low_Bound (P_Type));
6734 UBound := Expr_Value_R (Type_High_Bound (P_Type));
6735 Bound := UR_Max (UR_Abs (LBound), UR_Abs (UBound));
6736 Max_Man := UR_Trunc (Bound / Small_Value (P_Type));
6738 -- If the Bound is exactly a model number, i.e. a multiple
6739 -- of Small, then we back it off by one to get the integer
6740 -- value that must be representable.
6742 if Small_Value (P_Type) * Max_Man = Bound then
6743 Max_Man := Max_Man - 1;
6746 -- Now find corresponding size = Mantissa value
6749 while 2 ** Siz < Max_Man loop
6753 Fold_Uint (N, Siz, True);
6757 -- The case of dynamic bounds cannot be evaluated at compile
6758 -- time. Instead we use a runtime routine (see Exp_Attr).
6763 -- Floating-point Mantissa
6766 Fold_Uint (N, Mantissa, True);
6773 when Attribute_Max => Max :
6775 if Is_Real_Type (P_Type) then
6777 (N, UR_Max (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6779 Fold_Uint (N, UI_Max (Expr_Value (E1), Expr_Value (E2)), Static);
6783 ----------------------------------
6784 -- Max_Alignment_For_Allocation --
6785 ----------------------------------
6787 -- Max_Alignment_For_Allocation is usually the Alignment. However,
6788 -- arrays are allocated with dope, so we need to take into account both
6789 -- the alignment of the array, which comes from the component alignment,
6790 -- and the alignment of the dope. Also, if the alignment is unknown, we
6791 -- use the max (it's OK to be pessimistic).
6793 when Attribute_Max_Alignment_For_Allocation =>
6795 A : Uint := UI_From_Int (Ttypes.Maximum_Alignment);
6797 if Known_Alignment (P_Type) and then
6798 (not Is_Array_Type (P_Type) or else Alignment (P_Type) > A)
6800 A := Alignment (P_Type);
6803 Fold_Uint (N, A, Static);
6806 ----------------------------------
6807 -- Max_Size_In_Storage_Elements --
6808 ----------------------------------
6810 -- Max_Size_In_Storage_Elements is simply the Size rounded up to a
6811 -- Storage_Unit boundary. We can fold any cases for which the size
6812 -- is known by the front end.
6814 when Attribute_Max_Size_In_Storage_Elements =>
6815 if Known_Esize (P_Type) then
6817 (Esize (P_Type) + System_Storage_Unit - 1) /
6818 System_Storage_Unit,
6822 --------------------
6823 -- Mechanism_Code --
6824 --------------------
6826 when Attribute_Mechanism_Code =>
6830 Mech : Mechanism_Type;
6834 Mech := Mechanism (P_Entity);
6837 Val := UI_To_Int (Expr_Value (E1));
6839 Formal := First_Formal (P_Entity);
6840 for J in 1 .. Val - 1 loop
6841 Next_Formal (Formal);
6843 Mech := Mechanism (Formal);
6847 Fold_Uint (N, UI_From_Int (Int (-Mech)), True);
6855 when Attribute_Min => Min :
6857 if Is_Real_Type (P_Type) then
6859 (N, UR_Min (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6862 (N, UI_Min (Expr_Value (E1), Expr_Value (E2)), Static);
6870 when Attribute_Mod =>
6872 (N, UI_Mod (Expr_Value (E1), Modulus (P_Base_Type)), Static);
6878 when Attribute_Model =>
6880 Eval_Fat.Model (P_Root_Type, Expr_Value_R (E1)), Static);
6886 when Attribute_Model_Emin =>
6887 Fold_Uint (N, Model_Emin_Value (P_Base_Type), Static);
6893 when Attribute_Model_Epsilon =>
6894 Fold_Ureal (N, Model_Epsilon_Value (P_Base_Type), Static);
6896 --------------------
6897 -- Model_Mantissa --
6898 --------------------
6900 when Attribute_Model_Mantissa =>
6901 Fold_Uint (N, Model_Mantissa_Value (P_Base_Type), Static);
6907 when Attribute_Model_Small =>
6908 Fold_Ureal (N, Model_Small_Value (P_Base_Type), Static);
6914 when Attribute_Modulus =>
6915 Fold_Uint (N, Modulus (P_Type), True);
6917 --------------------
6918 -- Null_Parameter --
6919 --------------------
6921 -- Cannot fold, we know the value sort of, but the whole point is
6922 -- that there is no way to talk about this imaginary value except
6923 -- by using the attribute, so we leave it the way it is.
6925 when Attribute_Null_Parameter =>
6932 -- The Object_Size attribute for a type returns the Esize of the
6933 -- type and can be folded if this value is known.
6935 when Attribute_Object_Size => Object_Size : declare
6936 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6939 if Known_Esize (P_TypeA) then
6940 Fold_Uint (N, Esize (P_TypeA), True);
6944 ----------------------
6945 -- Overlaps_Storage --
6946 ----------------------
6948 when Attribute_Overlaps_Storage =>
6951 -------------------------
6952 -- Passed_By_Reference --
6953 -------------------------
6955 -- Scalar types are never passed by reference
6957 when Attribute_Passed_By_Reference =>
6958 Fold_Uint (N, False_Value, True);
6964 when Attribute_Pos =>
6965 Fold_Uint (N, Expr_Value (E1), True);
6971 when Attribute_Pred => Pred :
6973 -- Floating-point case
6975 if Is_Floating_Point_Type (P_Type) then
6977 Eval_Fat.Pred (P_Root_Type, Expr_Value_R (E1)), Static);
6981 elsif Is_Fixed_Point_Type (P_Type) then
6983 Expr_Value_R (E1) - Small_Value (P_Type), True);
6985 -- Modular integer case (wraps)
6987 elsif Is_Modular_Integer_Type (P_Type) then
6988 Fold_Uint (N, (Expr_Value (E1) - 1) mod Modulus (P_Type), Static);
6990 -- Other scalar cases
6993 pragma Assert (Is_Scalar_Type (P_Type));
6995 if Is_Enumeration_Type (P_Type)
6996 and then Expr_Value (E1) =
6997 Expr_Value (Type_Low_Bound (P_Base_Type))
6999 Apply_Compile_Time_Constraint_Error
7000 (N, "Pred of `&''First`",
7001 CE_Overflow_Check_Failed,
7003 Warn => not Static);
7009 Fold_Uint (N, Expr_Value (E1) - 1, Static);
7017 -- No processing required, because by this stage, Range has been
7018 -- replaced by First .. Last, so this branch can never be taken.
7020 when Attribute_Range =>
7021 raise Program_Error;
7027 when Attribute_Range_Length =>
7030 -- Can fold if both bounds are compile time known
7032 if Compile_Time_Known_Value (Hi_Bound)
7033 and then Compile_Time_Known_Value (Lo_Bound)
7037 (0, Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound) + 1),
7041 -- One more case is where Hi_Bound and Lo_Bound are compile-time
7042 -- comparable, and we can figure out the difference between them.
7045 Diff : aliased Uint;
7049 Compile_Time_Compare
7050 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
7053 Fold_Uint (N, Uint_1, False);
7056 Fold_Uint (N, Uint_0, False);
7059 if Diff /= No_Uint then
7060 Fold_Uint (N, Diff + 1, False);
7072 when Attribute_Ref =>
7073 Fold_Uint (N, Expr_Value (E1), True);
7079 when Attribute_Remainder => Remainder : declare
7080 X : constant Ureal := Expr_Value_R (E1);
7081 Y : constant Ureal := Expr_Value_R (E2);
7084 if UR_Is_Zero (Y) then
7085 Apply_Compile_Time_Constraint_Error
7086 (N, "division by zero in Remainder",
7087 CE_Overflow_Check_Failed,
7088 Warn => not Static);
7094 Fold_Ureal (N, Eval_Fat.Remainder (P_Root_Type, X, Y), Static);
7101 when Attribute_Round => Round :
7107 -- First we get the (exact result) in units of small
7109 Sr := Expr_Value_R (E1) / Small_Value (C_Type);
7111 -- Now round that exactly to an integer
7113 Si := UR_To_Uint (Sr);
7115 -- Finally the result is obtained by converting back to real
7117 Fold_Ureal (N, Si * Small_Value (C_Type), Static);
7124 when Attribute_Rounding =>
7126 Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static);
7132 when Attribute_Safe_Emax =>
7133 Fold_Uint (N, Safe_Emax_Value (P_Type), Static);
7139 when Attribute_Safe_First =>
7140 Fold_Ureal (N, Safe_First_Value (P_Type), Static);
7146 when Attribute_Safe_Large =>
7147 if Is_Fixed_Point_Type (P_Type) then
7149 (N, Expr_Value_R (Type_High_Bound (P_Base_Type)), Static);
7151 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
7158 when Attribute_Safe_Last =>
7159 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
7165 when Attribute_Safe_Small =>
7167 -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant
7168 -- for fixed-point, since is the same as Small, but we implement
7169 -- it for backwards compatibility.
7171 if Is_Fixed_Point_Type (P_Type) then
7172 Fold_Ureal (N, Small_Value (P_Type), Static);
7174 -- Ada 83 Safe_Small for floating-point cases
7177 Fold_Ureal (N, Model_Small_Value (P_Type), Static);
7184 when Attribute_Same_Storage =>
7191 when Attribute_Scale =>
7192 Fold_Uint (N, Scale_Value (P_Type), True);
7198 when Attribute_Scaling =>
7201 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
7207 when Attribute_Signed_Zeros =>
7209 (N, UI_From_Int (Boolean'Pos (Signed_Zeros_On_Target)), Static);
7215 -- Size attribute returns the RM size. All scalar types can be folded,
7216 -- as well as any types for which the size is known by the front end,
7217 -- including any type for which a size attribute is specified.
7219 when Attribute_Size | Attribute_VADS_Size => Size : declare
7220 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
7223 if RM_Size (P_TypeA) /= Uint_0 then
7227 if Id = Attribute_VADS_Size or else Use_VADS_Size then
7229 S : constant Node_Id := Size_Clause (P_TypeA);
7232 -- If a size clause applies, then use the size from it.
7233 -- This is one of the rare cases where we can use the
7234 -- Size_Clause field for a subtype when Has_Size_Clause
7235 -- is False. Consider:
7237 -- type x is range 1 .. 64;
7238 -- for x'size use 12;
7239 -- subtype y is x range 0 .. 3;
7241 -- Here y has a size clause inherited from x, but normally
7242 -- it does not apply, and y'size is 2. However, y'VADS_Size
7243 -- is indeed 12 and not 2.
7246 and then Is_OK_Static_Expression (Expression (S))
7248 Fold_Uint (N, Expr_Value (Expression (S)), True);
7250 -- If no size is specified, then we simply use the object
7251 -- size in the VADS_Size case (e.g. Natural'Size is equal
7252 -- to Integer'Size, not one less).
7255 Fold_Uint (N, Esize (P_TypeA), True);
7259 -- Normal case (Size) in which case we want the RM_Size
7264 Static and then Is_Discrete_Type (P_TypeA));
7273 when Attribute_Small =>
7275 -- The floating-point case is present only for Ada 83 compatibility.
7276 -- Note that strictly this is an illegal addition, since we are
7277 -- extending an Ada 95 defined attribute, but we anticipate an
7278 -- ARG ruling that will permit this.
7280 if Is_Floating_Point_Type (P_Type) then
7282 -- Ada 83 attribute is defined as (RM83 3.5.8)
7284 -- T'Small = 2.0**(-T'Emax - 1)
7288 -- T'Emax = 4 * T'Mantissa
7290 Fold_Ureal (N, Ureal_2 ** ((-(4 * Mantissa)) - 1), Static);
7292 -- Normal Ada 95 fixed-point case
7295 Fold_Ureal (N, Small_Value (P_Type), True);
7302 when Attribute_Stream_Size =>
7309 when Attribute_Succ => Succ :
7311 -- Floating-point case
7313 if Is_Floating_Point_Type (P_Type) then
7315 Eval_Fat.Succ (P_Root_Type, Expr_Value_R (E1)), Static);
7319 elsif Is_Fixed_Point_Type (P_Type) then
7321 Expr_Value_R (E1) + Small_Value (P_Type), Static);
7323 -- Modular integer case (wraps)
7325 elsif Is_Modular_Integer_Type (P_Type) then
7326 Fold_Uint (N, (Expr_Value (E1) + 1) mod Modulus (P_Type), Static);
7328 -- Other scalar cases
7331 pragma Assert (Is_Scalar_Type (P_Type));
7333 if Is_Enumeration_Type (P_Type)
7334 and then Expr_Value (E1) =
7335 Expr_Value (Type_High_Bound (P_Base_Type))
7337 Apply_Compile_Time_Constraint_Error
7338 (N, "Succ of `&''Last`",
7339 CE_Overflow_Check_Failed,
7341 Warn => not Static);
7346 Fold_Uint (N, Expr_Value (E1) + 1, Static);
7355 when Attribute_Truncation =>
7357 Eval_Fat.Truncation (P_Root_Type, Expr_Value_R (E1)), Static);
7363 when Attribute_Type_Class => Type_Class : declare
7364 Typ : constant Entity_Id := Underlying_Type (P_Base_Type);
7368 if Is_Descendent_Of_Address (Typ) then
7369 Id := RE_Type_Class_Address;
7371 elsif Is_Enumeration_Type (Typ) then
7372 Id := RE_Type_Class_Enumeration;
7374 elsif Is_Integer_Type (Typ) then
7375 Id := RE_Type_Class_Integer;
7377 elsif Is_Fixed_Point_Type (Typ) then
7378 Id := RE_Type_Class_Fixed_Point;
7380 elsif Is_Floating_Point_Type (Typ) then
7381 Id := RE_Type_Class_Floating_Point;
7383 elsif Is_Array_Type (Typ) then
7384 Id := RE_Type_Class_Array;
7386 elsif Is_Record_Type (Typ) then
7387 Id := RE_Type_Class_Record;
7389 elsif Is_Access_Type (Typ) then
7390 Id := RE_Type_Class_Access;
7392 elsif Is_Enumeration_Type (Typ) then
7393 Id := RE_Type_Class_Enumeration;
7395 elsif Is_Task_Type (Typ) then
7396 Id := RE_Type_Class_Task;
7398 -- We treat protected types like task types. It would make more
7399 -- sense to have another enumeration value, but after all the
7400 -- whole point of this feature is to be exactly DEC compatible,
7401 -- and changing the type Type_Class would not meet this requirement.
7403 elsif Is_Protected_Type (Typ) then
7404 Id := RE_Type_Class_Task;
7406 -- Not clear if there are any other possibilities, but if there
7407 -- are, then we will treat them as the address case.
7410 Id := RE_Type_Class_Address;
7413 Rewrite (N, New_Occurrence_Of (RTE (Id), Loc));
7416 -----------------------
7417 -- Unbiased_Rounding --
7418 -----------------------
7420 when Attribute_Unbiased_Rounding =>
7422 Eval_Fat.Unbiased_Rounding (P_Root_Type, Expr_Value_R (E1)),
7425 -------------------------
7426 -- Unconstrained_Array --
7427 -------------------------
7429 when Attribute_Unconstrained_Array => Unconstrained_Array : declare
7430 Typ : constant Entity_Id := Underlying_Type (P_Type);
7433 Rewrite (N, New_Occurrence_Of (
7435 Is_Array_Type (P_Type)
7436 and then not Is_Constrained (Typ)), Loc));
7438 -- Analyze and resolve as boolean, note that this attribute is
7439 -- a static attribute in GNAT.
7441 Analyze_And_Resolve (N, Standard_Boolean);
7443 end Unconstrained_Array;
7449 -- Processing is shared with Size
7455 when Attribute_Val => Val :
7457 if Expr_Value (E1) < Expr_Value (Type_Low_Bound (P_Base_Type))
7459 Expr_Value (E1) > Expr_Value (Type_High_Bound (P_Base_Type))
7461 Apply_Compile_Time_Constraint_Error
7462 (N, "Val expression out of range",
7463 CE_Range_Check_Failed,
7464 Warn => not Static);
7470 Fold_Uint (N, Expr_Value (E1), Static);
7478 -- The Value_Size attribute for a type returns the RM size of the
7479 -- type. This an always be folded for scalar types, and can also
7480 -- be folded for non-scalar types if the size is set.
7482 when Attribute_Value_Size => Value_Size : declare
7483 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
7485 if RM_Size (P_TypeA) /= Uint_0 then
7486 Fold_Uint (N, RM_Size (P_TypeA), True);
7494 -- Version can never be static
7496 when Attribute_Version =>
7503 -- Wide_Image is a scalar attribute, but is never static, because it
7504 -- is not a static function (having a non-scalar argument (RM 4.9(22))
7506 when Attribute_Wide_Image =>
7509 ---------------------
7510 -- Wide_Wide_Image --
7511 ---------------------
7513 -- Wide_Wide_Image is a scalar attribute but is never static, because it
7514 -- is not a static function (having a non-scalar argument (RM 4.9(22)).
7516 when Attribute_Wide_Wide_Image =>
7519 ---------------------
7520 -- Wide_Wide_Width --
7521 ---------------------
7523 -- Processing for Wide_Wide_Width is combined with Width
7529 -- Processing for Wide_Width is combined with Width
7535 -- This processing also handles the case of Wide_[Wide_]Width
7537 when Attribute_Width |
7538 Attribute_Wide_Width |
7539 Attribute_Wide_Wide_Width => Width :
7541 if Compile_Time_Known_Bounds (P_Type) then
7543 -- Floating-point types
7545 if Is_Floating_Point_Type (P_Type) then
7547 -- Width is zero for a null range (RM 3.5 (38))
7549 if Expr_Value_R (Type_High_Bound (P_Type)) <
7550 Expr_Value_R (Type_Low_Bound (P_Type))
7552 Fold_Uint (N, Uint_0, True);
7555 -- For floating-point, we have +N.dddE+nnn where length
7556 -- of ddd is determined by type'Digits - 1, but is one
7557 -- if Digits is one (RM 3.5 (33)).
7559 -- nnn is set to 2 for Short_Float and Float (32 bit
7560 -- floats), and 3 for Long_Float and Long_Long_Float.
7561 -- For machines where Long_Long_Float is the IEEE
7562 -- extended precision type, the exponent takes 4 digits.
7566 Int'Max (2, UI_To_Int (Digits_Value (P_Type)));
7569 if Esize (P_Type) <= 32 then
7571 elsif Esize (P_Type) = 64 then
7577 Fold_Uint (N, UI_From_Int (Len), True);
7581 -- Fixed-point types
7583 elsif Is_Fixed_Point_Type (P_Type) then
7585 -- Width is zero for a null range (RM 3.5 (38))
7587 if Expr_Value (Type_High_Bound (P_Type)) <
7588 Expr_Value (Type_Low_Bound (P_Type))
7590 Fold_Uint (N, Uint_0, True);
7592 -- The non-null case depends on the specific real type
7595 -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34))
7598 (N, UI_From_Int (Fore_Value + 1) + Aft_Value (P_Type),
7606 R : constant Entity_Id := Root_Type (P_Type);
7607 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
7608 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
7621 -- Width for types derived from Standard.Character
7622 -- and Standard.Wide_[Wide_]Character.
7624 elsif Is_Standard_Character_Type (P_Type) then
7627 -- Set W larger if needed
7629 for J in UI_To_Int (Lo) .. UI_To_Int (Hi) loop
7631 -- All wide characters look like Hex_hhhhhhhh
7635 -- No need to compute this more than once!
7640 C := Character'Val (J);
7642 -- Test for all cases where Character'Image
7643 -- yields an image that is longer than three
7644 -- characters. First the cases of Reserved_xxx
7645 -- names (length = 12).
7648 when Reserved_128 | Reserved_129 |
7649 Reserved_132 | Reserved_153
7652 when BS | HT | LF | VT | FF | CR |
7653 SO | SI | EM | FS | GS | RS |
7654 US | RI | MW | ST | PM
7657 when NUL | SOH | STX | ETX | EOT |
7658 ENQ | ACK | BEL | DLE | DC1 |
7659 DC2 | DC3 | DC4 | NAK | SYN |
7660 ETB | CAN | SUB | ESC | DEL |
7661 BPH | NBH | NEL | SSA | ESA |
7662 HTS | HTJ | VTS | PLD | PLU |
7663 SS2 | SS3 | DCS | PU1 | PU2 |
7664 STS | CCH | SPA | EPA | SOS |
7665 SCI | CSI | OSC | APC
7668 when Space .. Tilde |
7669 No_Break_Space .. LC_Y_Diaeresis
7671 -- Special case of soft hyphen in Ada 2005
7673 if C = Character'Val (16#AD#)
7674 and then Ada_Version >= Ada_2005
7682 W := Int'Max (W, Wt);
7686 -- Width for types derived from Standard.Boolean
7688 elsif R = Standard_Boolean then
7695 -- Width for integer types
7697 elsif Is_Integer_Type (P_Type) then
7698 T := UI_Max (abs Lo, abs Hi);
7706 -- Only remaining possibility is user declared enum type
7709 pragma Assert (Is_Enumeration_Type (P_Type));
7712 L := First_Literal (P_Type);
7714 while Present (L) loop
7716 -- Only pay attention to in range characters
7718 if Lo <= Enumeration_Pos (L)
7719 and then Enumeration_Pos (L) <= Hi
7721 -- For Width case, use decoded name
7723 if Id = Attribute_Width then
7724 Get_Decoded_Name_String (Chars (L));
7725 Wt := Nat (Name_Len);
7727 -- For Wide_[Wide_]Width, use encoded name, and
7728 -- then adjust for the encoding.
7731 Get_Name_String (Chars (L));
7733 -- Character literals are always of length 3
7735 if Name_Buffer (1) = 'Q' then
7738 -- Otherwise loop to adjust for upper/wide chars
7741 Wt := Nat (Name_Len);
7743 for J in 1 .. Name_Len loop
7744 if Name_Buffer (J) = 'U' then
7746 elsif Name_Buffer (J) = 'W' then
7753 W := Int'Max (W, Wt);
7760 Fold_Uint (N, UI_From_Int (W), True);
7766 -- The following attributes denote functions that cannot be folded
7768 when Attribute_From_Any |
7770 Attribute_TypeCode =>
7773 -- The following attributes can never be folded, and furthermore we
7774 -- should not even have entered the case statement for any of these.
7775 -- Note that in some cases, the values have already been folded as
7776 -- a result of the processing in Analyze_Attribute.
7778 when Attribute_Abort_Signal |
7781 Attribute_Address_Size |
7782 Attribute_Asm_Input |
7783 Attribute_Asm_Output |
7785 Attribute_Bit_Order |
7786 Attribute_Bit_Position |
7787 Attribute_Callable |
7790 Attribute_Code_Address |
7791 Attribute_Compiler_Version |
7793 Attribute_Default_Bit_Order |
7794 Attribute_Elaborated |
7795 Attribute_Elab_Body |
7796 Attribute_Elab_Spec |
7797 Attribute_Elab_Subp_Body |
7799 Attribute_External_Tag |
7800 Attribute_Fast_Math |
7801 Attribute_First_Bit |
7803 Attribute_Last_Bit |
7804 Attribute_Maximum_Alignment |
7807 Attribute_Partition_ID |
7808 Attribute_Pool_Address |
7809 Attribute_Position |
7810 Attribute_Priority |
7813 Attribute_Storage_Pool |
7814 Attribute_Storage_Size |
7815 Attribute_Storage_Unit |
7816 Attribute_Stub_Type |
7817 Attribute_System_Allocator_Alignment |
7819 Attribute_Target_Name |
7820 Attribute_Terminated |
7821 Attribute_To_Address |
7822 Attribute_Type_Key |
7823 Attribute_UET_Address |
7824 Attribute_Unchecked_Access |
7825 Attribute_Universal_Literal_String |
7826 Attribute_Unrestricted_Access |
7829 Attribute_Wchar_T_Size |
7830 Attribute_Wide_Value |
7831 Attribute_Wide_Wide_Value |
7832 Attribute_Word_Size |
7835 raise Program_Error;
7838 -- At the end of the case, one more check. If we did a static evaluation
7839 -- so that the result is now a literal, then set Is_Static_Expression
7840 -- in the constant only if the prefix type is a static subtype. For
7841 -- non-static subtypes, the folding is still OK, but not static.
7843 -- An exception is the GNAT attribute Constrained_Array which is
7844 -- defined to be a static attribute in all cases.
7846 if Nkind_In (N, N_Integer_Literal,
7848 N_Character_Literal,
7850 or else (Is_Entity_Name (N)
7851 and then Ekind (Entity (N)) = E_Enumeration_Literal)
7853 Set_Is_Static_Expression (N, Static);
7855 -- If this is still an attribute reference, then it has not been folded
7856 -- and that means that its expressions are in a non-static context.
7858 elsif Nkind (N) = N_Attribute_Reference then
7861 -- Note: the else case not covered here are odd cases where the
7862 -- processing has transformed the attribute into something other
7863 -- than a constant. Nothing more to do in such cases.
7870 ------------------------------
7871 -- Is_Anonymous_Tagged_Base --
7872 ------------------------------
7874 function Is_Anonymous_Tagged_Base
7881 Anon = Current_Scope
7882 and then Is_Itype (Anon)
7883 and then Associated_Node_For_Itype (Anon) = Parent (Typ);
7884 end Is_Anonymous_Tagged_Base;
7886 --------------------------------
7887 -- Name_Implies_Lvalue_Prefix --
7888 --------------------------------
7890 function Name_Implies_Lvalue_Prefix (Nam : Name_Id) return Boolean is
7891 pragma Assert (Is_Attribute_Name (Nam));
7893 return Attribute_Name_Implies_Lvalue_Prefix (Get_Attribute_Id (Nam));
7894 end Name_Implies_Lvalue_Prefix;
7896 -----------------------
7897 -- Resolve_Attribute --
7898 -----------------------
7900 procedure Resolve_Attribute (N : Node_Id; Typ : Entity_Id) is
7901 Loc : constant Source_Ptr := Sloc (N);
7902 P : constant Node_Id := Prefix (N);
7903 Aname : constant Name_Id := Attribute_Name (N);
7904 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
7905 Btyp : constant Entity_Id := Base_Type (Typ);
7906 Des_Btyp : Entity_Id;
7907 Index : Interp_Index;
7909 Nom_Subt : Entity_Id;
7911 procedure Accessibility_Message;
7912 -- Error, or warning within an instance, if the static accessibility
7913 -- rules of 3.10.2 are violated.
7915 ---------------------------
7916 -- Accessibility_Message --
7917 ---------------------------
7919 procedure Accessibility_Message is
7920 Indic : Node_Id := Parent (Parent (N));
7923 -- In an instance, this is a runtime check, but one we
7924 -- know will fail, so generate an appropriate warning.
7926 if In_Instance_Body then
7927 Error_Msg_F ("?non-local pointer cannot point to local object", P);
7929 ("\?Program_Error will be raised at run time", P);
7931 Make_Raise_Program_Error (Loc,
7932 Reason => PE_Accessibility_Check_Failed));
7937 Error_Msg_F ("non-local pointer cannot point to local object", P);
7939 -- Check for case where we have a missing access definition
7941 if Is_Record_Type (Current_Scope)
7943 Nkind_In (Parent (N), N_Discriminant_Association,
7944 N_Index_Or_Discriminant_Constraint)
7946 Indic := Parent (Parent (N));
7947 while Present (Indic)
7948 and then Nkind (Indic) /= N_Subtype_Indication
7950 Indic := Parent (Indic);
7953 if Present (Indic) then
7955 ("\use an access definition for" &
7956 " the access discriminant of&",
7957 N, Entity (Subtype_Mark (Indic)));
7961 end Accessibility_Message;
7963 -- Start of processing for Resolve_Attribute
7966 -- If error during analysis, no point in continuing, except for array
7967 -- types, where we get better recovery by using unconstrained indexes
7968 -- than nothing at all (see Check_Array_Type).
7971 and then Attr_Id /= Attribute_First
7972 and then Attr_Id /= Attribute_Last
7973 and then Attr_Id /= Attribute_Length
7974 and then Attr_Id /= Attribute_Range
7979 -- If attribute was universal type, reset to actual type
7981 if Etype (N) = Universal_Integer
7982 or else Etype (N) = Universal_Real
7987 -- Remaining processing depends on attribute
7995 -- For access attributes, if the prefix denotes an entity, it is
7996 -- interpreted as a name, never as a call. It may be overloaded,
7997 -- in which case resolution uses the profile of the context type.
7998 -- Otherwise prefix must be resolved.
8000 when Attribute_Access
8001 | Attribute_Unchecked_Access
8002 | Attribute_Unrestricted_Access =>
8006 if Is_Variable (P) then
8007 Note_Possible_Modification (P, Sure => False);
8010 -- The following comes from a query by Adam Beneschan, concerning
8011 -- improper use of universal_access in equality tests involving
8012 -- anonymous access types. Another good reason for 'Ref, but
8013 -- for now disable the test, which breaks several filed tests.
8015 if Ekind (Typ) = E_Anonymous_Access_Type
8016 and then Nkind_In (Parent (N), N_Op_Eq, N_Op_Ne)
8019 Error_Msg_N ("need unique type to resolve 'Access", N);
8020 Error_Msg_N ("\qualify attribute with some access type", N);
8023 if Is_Entity_Name (P) then
8024 if Is_Overloaded (P) then
8025 Get_First_Interp (P, Index, It);
8026 while Present (It.Nam) loop
8027 if Type_Conformant (Designated_Type (Typ), It.Nam) then
8028 Set_Entity (P, It.Nam);
8030 -- The prefix is definitely NOT overloaded anymore at
8031 -- this point, so we reset the Is_Overloaded flag to
8032 -- avoid any confusion when reanalyzing the node.
8034 Set_Is_Overloaded (P, False);
8035 Set_Is_Overloaded (N, False);
8036 Generate_Reference (Entity (P), P);
8040 Get_Next_Interp (Index, It);
8043 -- If Prefix is a subprogram name, it is frozen by this
8046 -- If it is a type, there is nothing to resolve.
8047 -- If it is an object, complete its resolution.
8049 elsif Is_Overloadable (Entity (P)) then
8051 -- Avoid insertion of freeze actions in spec expression mode
8053 if not In_Spec_Expression then
8054 Freeze_Before (N, Entity (P));
8057 elsif Is_Type (Entity (P)) then
8063 Error_Msg_Name_1 := Aname;
8065 if not Is_Entity_Name (P) then
8068 elsif Is_Overloadable (Entity (P))
8069 and then Is_Abstract_Subprogram (Entity (P))
8071 Error_Msg_F ("prefix of % attribute cannot be abstract", P);
8072 Set_Etype (N, Any_Type);
8074 elsif Convention (Entity (P)) = Convention_Intrinsic then
8075 if Ekind (Entity (P)) = E_Enumeration_Literal then
8077 ("prefix of % attribute cannot be enumeration literal",
8081 ("prefix of % attribute cannot be intrinsic", P);
8084 Set_Etype (N, Any_Type);
8087 -- Assignments, return statements, components of aggregates,
8088 -- generic instantiations will require convention checks if
8089 -- the type is an access to subprogram. Given that there will
8090 -- also be accessibility checks on those, this is where the
8091 -- checks can eventually be centralized ???
8093 if Ekind_In (Btyp, E_Access_Subprogram_Type,
8094 E_Anonymous_Access_Subprogram_Type,
8095 E_Access_Protected_Subprogram_Type,
8096 E_Anonymous_Access_Protected_Subprogram_Type)
8098 -- Deal with convention mismatch
8100 if Convention (Designated_Type (Btyp)) /=
8101 Convention (Entity (P))
8104 ("subprogram & has wrong convention", P, Entity (P));
8106 ("\does not match convention of access type &",
8109 if not Has_Convention_Pragma (Btyp) then
8111 ("\probable missing pragma Convention for &",
8116 Check_Subtype_Conformant
8117 (New_Id => Entity (P),
8118 Old_Id => Designated_Type (Btyp),
8122 if Attr_Id = Attribute_Unchecked_Access then
8123 Error_Msg_Name_1 := Aname;
8125 ("attribute% cannot be applied to a subprogram", P);
8127 elsif Aname = Name_Unrestricted_Access then
8128 null; -- Nothing to check
8130 -- Check the static accessibility rule of 3.10.2(32).
8131 -- This rule also applies within the private part of an
8132 -- instantiation. This rule does not apply to anonymous
8133 -- access-to-subprogram types in access parameters.
8135 elsif Attr_Id = Attribute_Access
8136 and then not In_Instance_Body
8138 (Ekind (Btyp) = E_Access_Subprogram_Type
8139 or else Is_Local_Anonymous_Access (Btyp))
8141 and then Subprogram_Access_Level (Entity (P)) >
8142 Type_Access_Level (Btyp)
8145 ("subprogram must not be deeper than access type", P);
8147 -- Check the restriction of 3.10.2(32) that disallows the
8148 -- access attribute within a generic body when the ultimate
8149 -- ancestor of the type of the attribute is declared outside
8150 -- of the generic unit and the subprogram is declared within
8151 -- that generic unit. This includes any such attribute that
8152 -- occurs within the body of a generic unit that is a child
8153 -- of the generic unit where the subprogram is declared.
8155 -- The rule also prohibits applying the attribute when the
8156 -- access type is a generic formal access type (since the
8157 -- level of the actual type is not known). This restriction
8158 -- does not apply when the attribute type is an anonymous
8159 -- access-to-subprogram type. Note that this check was
8160 -- revised by AI-229, because the originally Ada 95 rule
8161 -- was too lax. The original rule only applied when the
8162 -- subprogram was declared within the body of the generic,
8163 -- which allowed the possibility of dangling references).
8164 -- The rule was also too strict in some case, in that it
8165 -- didn't permit the access to be declared in the generic
8166 -- spec, whereas the revised rule does (as long as it's not
8169 -- There are a couple of subtleties of the test for applying
8170 -- the check that are worth noting. First, we only apply it
8171 -- when the levels of the subprogram and access type are the
8172 -- same (the case where the subprogram is statically deeper
8173 -- was applied above, and the case where the type is deeper
8174 -- is always safe). Second, we want the check to apply
8175 -- within nested generic bodies and generic child unit
8176 -- bodies, but not to apply to an attribute that appears in
8177 -- the generic unit's specification. This is done by testing
8178 -- that the attribute's innermost enclosing generic body is
8179 -- not the same as the innermost generic body enclosing the
8180 -- generic unit where the subprogram is declared (we don't
8181 -- want the check to apply when the access attribute is in
8182 -- the spec and there's some other generic body enclosing
8183 -- generic). Finally, there's no point applying the check
8184 -- when within an instance, because any violations will have
8185 -- been caught by the compilation of the generic unit.
8187 -- Note that we relax this check in CodePeer mode for
8188 -- compatibility with legacy code, since CodePeer is an
8189 -- Ada source code analyzer, not a strict compiler.
8190 -- ??? Note that a better approach would be to have a
8191 -- separate switch to relax this rule, and enable this
8192 -- switch in CodePeer mode.
8194 elsif Attr_Id = Attribute_Access
8195 and then not CodePeer_Mode
8196 and then not In_Instance
8197 and then Present (Enclosing_Generic_Unit (Entity (P)))
8198 and then Present (Enclosing_Generic_Body (N))
8199 and then Enclosing_Generic_Body (N) /=
8200 Enclosing_Generic_Body
8201 (Enclosing_Generic_Unit (Entity (P)))
8202 and then Subprogram_Access_Level (Entity (P)) =
8203 Type_Access_Level (Btyp)
8204 and then Ekind (Btyp) /=
8205 E_Anonymous_Access_Subprogram_Type
8206 and then Ekind (Btyp) /=
8207 E_Anonymous_Access_Protected_Subprogram_Type
8209 -- The attribute type's ultimate ancestor must be
8210 -- declared within the same generic unit as the
8211 -- subprogram is declared. The error message is
8212 -- specialized to say "ancestor" for the case where the
8213 -- access type is not its own ancestor, since saying
8214 -- simply "access type" would be very confusing.
8216 if Enclosing_Generic_Unit (Entity (P)) /=
8217 Enclosing_Generic_Unit (Root_Type (Btyp))
8220 ("''Access attribute not allowed in generic body",
8223 if Root_Type (Btyp) = Btyp then
8226 "access type & is declared outside " &
8227 "generic unit (RM 3.10.2(32))", N, Btyp);
8230 ("\because ancestor of " &
8231 "access type & is declared outside " &
8232 "generic unit (RM 3.10.2(32))", N, Btyp);
8236 ("\move ''Access to private part, or " &
8237 "(Ada 2005) use anonymous access type instead of &",
8240 -- If the ultimate ancestor of the attribute's type is
8241 -- a formal type, then the attribute is illegal because
8242 -- the actual type might be declared at a higher level.
8243 -- The error message is specialized to say "ancestor"
8244 -- for the case where the access type is not its own
8245 -- ancestor, since saying simply "access type" would be
8248 elsif Is_Generic_Type (Root_Type (Btyp)) then
8249 if Root_Type (Btyp) = Btyp then
8251 ("access type must not be a generic formal type",
8255 ("ancestor access type must not be a generic " &
8262 -- If this is a renaming, an inherited operation, or a
8263 -- subprogram instance, use the original entity. This may make
8264 -- the node type-inconsistent, so this transformation can only
8265 -- be done if the node will not be reanalyzed. In particular,
8266 -- if it is within a default expression, the transformation
8267 -- must be delayed until the default subprogram is created for
8268 -- it, when the enclosing subprogram is frozen.
8270 if Is_Entity_Name (P)
8271 and then Is_Overloadable (Entity (P))
8272 and then Present (Alias (Entity (P)))
8273 and then Expander_Active
8276 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
8279 elsif Nkind (P) = N_Selected_Component
8280 and then Is_Overloadable (Entity (Selector_Name (P)))
8282 -- Protected operation. If operation is overloaded, must
8283 -- disambiguate. Prefix that denotes protected object itself
8284 -- is resolved with its own type.
8286 if Attr_Id = Attribute_Unchecked_Access then
8287 Error_Msg_Name_1 := Aname;
8289 ("attribute% cannot be applied to protected operation", P);
8292 Resolve (Prefix (P));
8293 Generate_Reference (Entity (Selector_Name (P)), P);
8295 elsif Is_Overloaded (P) then
8297 -- Use the designated type of the context to disambiguate
8298 -- Note that this was not strictly conformant to Ada 95,
8299 -- but was the implementation adopted by most Ada 95 compilers.
8300 -- The use of the context type to resolve an Access attribute
8301 -- reference is now mandated in AI-235 for Ada 2005.
8304 Index : Interp_Index;
8308 Get_First_Interp (P, Index, It);
8309 while Present (It.Typ) loop
8310 if Covers (Designated_Type (Typ), It.Typ) then
8311 Resolve (P, It.Typ);
8315 Get_Next_Interp (Index, It);
8322 -- X'Access is illegal if X denotes a constant and the access type
8323 -- is access-to-variable. Same for 'Unchecked_Access. The rule
8324 -- does not apply to 'Unrestricted_Access. If the reference is a
8325 -- default-initialized aggregate component for a self-referential
8326 -- type the reference is legal.
8328 if not (Ekind (Btyp) = E_Access_Subprogram_Type
8329 or else Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type
8330 or else (Is_Record_Type (Btyp)
8332 Present (Corresponding_Remote_Type (Btyp)))
8333 or else Ekind (Btyp) = E_Access_Protected_Subprogram_Type
8334 or else Ekind (Btyp)
8335 = E_Anonymous_Access_Protected_Subprogram_Type
8336 or else Is_Access_Constant (Btyp)
8337 or else Is_Variable (P)
8338 or else Attr_Id = Attribute_Unrestricted_Access)
8340 if Is_Entity_Name (P)
8341 and then Is_Type (Entity (P))
8343 -- Legality of a self-reference through an access
8344 -- attribute has been verified in Analyze_Access_Attribute.
8348 elsif Comes_From_Source (N) then
8349 Error_Msg_F ("access-to-variable designates constant", P);
8353 Des_Btyp := Designated_Type (Btyp);
8355 if Ada_Version >= Ada_2005
8356 and then Is_Incomplete_Type (Des_Btyp)
8358 -- Ada 2005 (AI-412): If the (sub)type is a limited view of an
8359 -- imported entity, and the non-limited view is visible, make
8360 -- use of it. If it is an incomplete subtype, use the base type
8363 if From_With_Type (Des_Btyp)
8364 and then Present (Non_Limited_View (Des_Btyp))
8366 Des_Btyp := Non_Limited_View (Des_Btyp);
8368 elsif Ekind (Des_Btyp) = E_Incomplete_Subtype then
8369 Des_Btyp := Etype (Des_Btyp);
8373 if (Attr_Id = Attribute_Access
8375 Attr_Id = Attribute_Unchecked_Access)
8376 and then (Ekind (Btyp) = E_General_Access_Type
8377 or else Ekind (Btyp) = E_Anonymous_Access_Type)
8379 -- Ada 2005 (AI-230): Check the accessibility of anonymous
8380 -- access types for stand-alone objects, record and array
8381 -- components, and return objects. For a component definition
8382 -- the level is the same of the enclosing composite type.
8384 if Ada_Version >= Ada_2005
8385 and then (Is_Local_Anonymous_Access (Btyp)
8387 -- Handle cases where Btyp is the
8388 -- anonymous access type of an Ada 2012
8389 -- stand-alone object.
8391 or else Nkind (Associated_Node_For_Itype (Btyp)) =
8392 N_Object_Declaration)
8393 and then Object_Access_Level (P)
8394 > Deepest_Type_Access_Level (Btyp)
8395 and then Attr_Id = Attribute_Access
8397 -- In an instance, this is a runtime check, but one we
8398 -- know will fail, so generate an appropriate warning.
8400 if In_Instance_Body then
8402 ("?non-local pointer cannot point to local object", P);
8404 ("\?Program_Error will be raised at run time", P);
8406 Make_Raise_Program_Error (Loc,
8407 Reason => PE_Accessibility_Check_Failed));
8412 ("non-local pointer cannot point to local object", P);
8416 if Is_Dependent_Component_Of_Mutable_Object (P) then
8418 ("illegal attribute for discriminant-dependent component",
8422 -- Check static matching rule of 3.10.2(27). Nominal subtype
8423 -- of the prefix must statically match the designated type.
8425 Nom_Subt := Etype (P);
8427 if Is_Constr_Subt_For_U_Nominal (Nom_Subt) then
8428 Nom_Subt := Base_Type (Nom_Subt);
8431 if Is_Tagged_Type (Designated_Type (Typ)) then
8433 -- If the attribute is in the context of an access
8434 -- parameter, then the prefix is allowed to be of the
8435 -- class-wide type (by AI-127).
8437 if Ekind (Typ) = E_Anonymous_Access_Type then
8438 if not Covers (Designated_Type (Typ), Nom_Subt)
8439 and then not Covers (Nom_Subt, Designated_Type (Typ))
8445 Desig := Designated_Type (Typ);
8447 if Is_Class_Wide_Type (Desig) then
8448 Desig := Etype (Desig);
8451 if Is_Anonymous_Tagged_Base (Nom_Subt, Desig) then
8456 ("type of prefix: & not compatible",
8459 ("\with &, the expected designated type",
8460 P, Designated_Type (Typ));
8465 elsif not Covers (Designated_Type (Typ), Nom_Subt)
8467 (not Is_Class_Wide_Type (Designated_Type (Typ))
8468 and then Is_Class_Wide_Type (Nom_Subt))
8471 ("type of prefix: & is not covered", P, Nom_Subt);
8473 ("\by &, the expected designated type" &
8474 " (RM 3.10.2 (27))", P, Designated_Type (Typ));
8477 if Is_Class_Wide_Type (Designated_Type (Typ))
8478 and then Has_Discriminants (Etype (Designated_Type (Typ)))
8479 and then Is_Constrained (Etype (Designated_Type (Typ)))
8480 and then Designated_Type (Typ) /= Nom_Subt
8482 Apply_Discriminant_Check
8483 (N, Etype (Designated_Type (Typ)));
8486 -- Ada 2005 (AI-363): Require static matching when designated
8487 -- type has discriminants and a constrained partial view, since
8488 -- in general objects of such types are mutable, so we can't
8489 -- allow the access value to designate a constrained object
8490 -- (because access values must be assumed to designate mutable
8491 -- objects when designated type does not impose a constraint).
8493 elsif Subtypes_Statically_Match (Des_Btyp, Nom_Subt) then
8496 elsif Has_Discriminants (Designated_Type (Typ))
8497 and then not Is_Constrained (Des_Btyp)
8499 (Ada_Version < Ada_2005
8501 not Has_Constrained_Partial_View
8502 (Designated_Type (Base_Type (Typ))))
8508 ("object subtype must statically match "
8509 & "designated subtype", P);
8511 if Is_Entity_Name (P)
8512 and then Is_Array_Type (Designated_Type (Typ))
8515 D : constant Node_Id := Declaration_Node (Entity (P));
8518 Error_Msg_N ("aliased object has explicit bounds?",
8520 Error_Msg_N ("\declare without bounds"
8521 & " (and with explicit initialization)?", D);
8522 Error_Msg_N ("\for use with unconstrained access?", D);
8527 -- Check the static accessibility rule of 3.10.2(28).
8528 -- Note that this check is not performed for the
8529 -- case of an anonymous access type, since the access
8530 -- attribute is always legal in such a context.
8532 if Attr_Id /= Attribute_Unchecked_Access
8533 and then Object_Access_Level (P) > Type_Access_Level (Btyp)
8534 and then Ekind (Btyp) = E_General_Access_Type
8536 Accessibility_Message;
8541 if Ekind_In (Btyp, E_Access_Protected_Subprogram_Type,
8542 E_Anonymous_Access_Protected_Subprogram_Type)
8544 if Is_Entity_Name (P)
8545 and then not Is_Protected_Type (Scope (Entity (P)))
8547 Error_Msg_F ("context requires a protected subprogram", P);
8549 -- Check accessibility of protected object against that of the
8550 -- access type, but only on user code, because the expander
8551 -- creates access references for handlers. If the context is an
8552 -- anonymous_access_to_protected, there are no accessibility
8553 -- checks either. Omit check entirely for Unrestricted_Access.
8555 elsif Object_Access_Level (P) > Type_Access_Level (Btyp)
8556 and then Comes_From_Source (N)
8557 and then Ekind (Btyp) = E_Access_Protected_Subprogram_Type
8558 and then Attr_Id /= Attribute_Unrestricted_Access
8560 Accessibility_Message;
8564 elsif Ekind_In (Btyp, E_Access_Subprogram_Type,
8565 E_Anonymous_Access_Subprogram_Type)
8566 and then Ekind (Etype (N)) = E_Access_Protected_Subprogram_Type
8568 Error_Msg_F ("context requires a non-protected subprogram", P);
8571 -- The context cannot be a pool-specific type, but this is a
8572 -- legality rule, not a resolution rule, so it must be checked
8573 -- separately, after possibly disambiguation (see AI-245).
8575 if Ekind (Btyp) = E_Access_Type
8576 and then Attr_Id /= Attribute_Unrestricted_Access
8578 Wrong_Type (N, Typ);
8581 -- The context may be a constrained access type (however ill-
8582 -- advised such subtypes might be) so in order to generate a
8583 -- constraint check when needed set the type of the attribute
8584 -- reference to the base type of the context.
8586 Set_Etype (N, Btyp);
8588 -- Check for incorrect atomic/volatile reference (RM C.6(12))
8590 if Attr_Id /= Attribute_Unrestricted_Access then
8591 if Is_Atomic_Object (P)
8592 and then not Is_Atomic (Designated_Type (Typ))
8595 ("access to atomic object cannot yield access-to-" &
8596 "non-atomic type", P);
8598 elsif Is_Volatile_Object (P)
8599 and then not Is_Volatile (Designated_Type (Typ))
8602 ("access to volatile object cannot yield access-to-" &
8603 "non-volatile type", P);
8607 if Is_Entity_Name (P) then
8608 Set_Address_Taken (Entity (P));
8610 end Access_Attribute;
8616 -- Deal with resolving the type for Address attribute, overloading
8617 -- is not permitted here, since there is no context to resolve it.
8619 when Attribute_Address | Attribute_Code_Address =>
8620 Address_Attribute : begin
8622 -- To be safe, assume that if the address of a variable is taken,
8623 -- it may be modified via this address, so note modification.
8625 if Is_Variable (P) then
8626 Note_Possible_Modification (P, Sure => False);
8629 if Nkind (P) in N_Subexpr
8630 and then Is_Overloaded (P)
8632 Get_First_Interp (P, Index, It);
8633 Get_Next_Interp (Index, It);
8635 if Present (It.Nam) then
8636 Error_Msg_Name_1 := Aname;
8638 ("prefix of % attribute cannot be overloaded", P);
8642 if not Is_Entity_Name (P)
8643 or else not Is_Overloadable (Entity (P))
8645 if not Is_Task_Type (Etype (P))
8646 or else Nkind (P) = N_Explicit_Dereference
8652 -- If this is the name of a derived subprogram, or that of a
8653 -- generic actual, the address is that of the original entity.
8655 if Is_Entity_Name (P)
8656 and then Is_Overloadable (Entity (P))
8657 and then Present (Alias (Entity (P)))
8660 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
8663 if Is_Entity_Name (P) then
8664 Set_Address_Taken (Entity (P));
8667 if Nkind (P) = N_Slice then
8669 -- Arr (X .. Y)'address is identical to Arr (X)'address,
8670 -- even if the array is packed and the slice itself is not
8671 -- addressable. Transform the prefix into an indexed component.
8673 -- Note that the transformation is safe only if we know that
8674 -- the slice is non-null. That is because a null slice can have
8675 -- an out of bounds index value.
8677 -- Right now, gigi blows up if given 'Address on a slice as a
8678 -- result of some incorrect freeze nodes generated by the front
8679 -- end, and this covers up that bug in one case, but the bug is
8680 -- likely still there in the cases not handled by this code ???
8682 -- It's not clear what 'Address *should* return for a null
8683 -- slice with out of bounds indexes, this might be worth an ARG
8686 -- One approach would be to do a length check unconditionally,
8687 -- and then do the transformation below unconditionally, but
8688 -- analyze with checks off, avoiding the problem of the out of
8689 -- bounds index. This approach would interpret the address of
8690 -- an out of bounds null slice as being the address where the
8691 -- array element would be if there was one, which is probably
8692 -- as reasonable an interpretation as any ???
8695 Loc : constant Source_Ptr := Sloc (P);
8696 D : constant Node_Id := Discrete_Range (P);
8700 if Is_Entity_Name (D)
8703 (Type_Low_Bound (Entity (D)),
8704 Type_High_Bound (Entity (D)))
8707 Make_Attribute_Reference (Loc,
8708 Prefix => (New_Occurrence_Of (Entity (D), Loc)),
8709 Attribute_Name => Name_First);
8711 elsif Nkind (D) = N_Range
8712 and then Not_Null_Range (Low_Bound (D), High_Bound (D))
8714 Lo := Low_Bound (D);
8720 if Present (Lo) then
8722 Make_Indexed_Component (Loc,
8723 Prefix => Relocate_Node (Prefix (P)),
8724 Expressions => New_List (Lo)));
8726 Analyze_And_Resolve (P);
8730 end Address_Attribute;
8736 -- Prefix of the AST_Entry attribute is an entry name which must
8737 -- not be resolved, since this is definitely not an entry call.
8739 when Attribute_AST_Entry =>
8746 -- Prefix of Body_Version attribute can be a subprogram name which
8747 -- must not be resolved, since this is not a call.
8749 when Attribute_Body_Version =>
8756 -- Prefix of Caller attribute is an entry name which must not
8757 -- be resolved, since this is definitely not an entry call.
8759 when Attribute_Caller =>
8766 -- Shares processing with Address attribute
8772 -- If the prefix of the Count attribute is an entry name it must not
8773 -- be resolved, since this is definitely not an entry call. However,
8774 -- if it is an element of an entry family, the index itself may
8775 -- have to be resolved because it can be a general expression.
8777 when Attribute_Count =>
8778 if Nkind (P) = N_Indexed_Component
8779 and then Is_Entity_Name (Prefix (P))
8782 Indx : constant Node_Id := First (Expressions (P));
8783 Fam : constant Entity_Id := Entity (Prefix (P));
8785 Resolve (Indx, Entry_Index_Type (Fam));
8786 Apply_Range_Check (Indx, Entry_Index_Type (Fam));
8794 -- Prefix of the Elaborated attribute is a subprogram name which
8795 -- must not be resolved, since this is definitely not a call. Note
8796 -- that it is a library unit, so it cannot be overloaded here.
8798 when Attribute_Elaborated =>
8805 -- Prefix of Enabled attribute is a check name, which must be treated
8806 -- specially and not touched by Resolve.
8808 when Attribute_Enabled =>
8811 --------------------
8812 -- Mechanism_Code --
8813 --------------------
8815 -- Prefix of the Mechanism_Code attribute is a function name
8816 -- which must not be resolved. Should we check for overloaded ???
8818 when Attribute_Mechanism_Code =>
8825 -- Most processing is done in sem_dist, after determining the
8826 -- context type. Node is rewritten as a conversion to a runtime call.
8828 when Attribute_Partition_ID =>
8829 Process_Partition_Id (N);
8836 when Attribute_Pool_Address =>
8843 -- We replace the Range attribute node with a range expression whose
8844 -- bounds are the 'First and 'Last attributes applied to the same
8845 -- prefix. The reason that we do this transformation here instead of
8846 -- in the expander is that it simplifies other parts of the semantic
8847 -- analysis which assume that the Range has been replaced; thus it
8848 -- must be done even when in semantic-only mode (note that the RM
8849 -- specifically mentions this equivalence, we take care that the
8850 -- prefix is only evaluated once).
8852 when Attribute_Range => Range_Attribute :
8858 if not Is_Entity_Name (P)
8859 or else not Is_Type (Entity (P))
8865 Make_Attribute_Reference (Loc,
8867 Duplicate_Subexpr (P, Name_Req => True),
8868 Attribute_Name => Name_Last,
8869 Expressions => Expressions (N));
8872 Make_Attribute_Reference (Loc,
8874 Attribute_Name => Name_First,
8875 Expressions => Expressions (N));
8877 -- If the original was marked as Must_Not_Freeze (see code
8878 -- in Sem_Ch3.Make_Index), then make sure the rewriting
8879 -- does not freeze either.
8881 if Must_Not_Freeze (N) then
8882 Set_Must_Not_Freeze (HB);
8883 Set_Must_Not_Freeze (LB);
8884 Set_Must_Not_Freeze (Prefix (HB));
8885 Set_Must_Not_Freeze (Prefix (LB));
8888 if Raises_Constraint_Error (Prefix (N)) then
8890 -- Preserve Sloc of prefix in the new bounds, so that
8891 -- the posted warning can be removed if we are within
8892 -- unreachable code.
8894 Set_Sloc (LB, Sloc (Prefix (N)));
8895 Set_Sloc (HB, Sloc (Prefix (N)));
8898 Rewrite (N, Make_Range (Loc, LB, HB));
8899 Analyze_And_Resolve (N, Typ);
8901 -- Ensure that the expanded range does not have side effects
8903 Force_Evaluation (LB);
8904 Force_Evaluation (HB);
8906 -- Normally after resolving attribute nodes, Eval_Attribute
8907 -- is called to do any possible static evaluation of the node.
8908 -- However, here since the Range attribute has just been
8909 -- transformed into a range expression it is no longer an
8910 -- attribute node and therefore the call needs to be avoided
8911 -- and is accomplished by simply returning from the procedure.
8914 end Range_Attribute;
8920 -- We will only come here during the prescan of a spec expression
8921 -- containing a Result attribute. In that case the proper Etype has
8922 -- already been set, and nothing more needs to be done here.
8924 when Attribute_Result =>
8931 -- Prefix must not be resolved in this case, since it is not a
8932 -- real entity reference. No action of any kind is require!
8934 when Attribute_UET_Address =>
8937 ----------------------
8938 -- Unchecked_Access --
8939 ----------------------
8941 -- Processing is shared with Access
8943 -------------------------
8944 -- Unrestricted_Access --
8945 -------------------------
8947 -- Processing is shared with Access
8953 -- Apply range check. Note that we did not do this during the
8954 -- analysis phase, since we wanted Eval_Attribute to have a
8955 -- chance at finding an illegal out of range value.
8957 when Attribute_Val =>
8959 -- Note that we do our own Eval_Attribute call here rather than
8960 -- use the common one, because we need to do processing after
8961 -- the call, as per above comment.
8965 -- Eval_Attribute may replace the node with a raise CE, or
8966 -- fold it to a constant. Obviously we only apply a scalar
8967 -- range check if this did not happen!
8969 if Nkind (N) = N_Attribute_Reference
8970 and then Attribute_Name (N) = Name_Val
8972 Apply_Scalar_Range_Check (First (Expressions (N)), Btyp);
8981 -- Prefix of Version attribute can be a subprogram name which
8982 -- must not be resolved, since this is not a call.
8984 when Attribute_Version =>
8987 ----------------------
8988 -- Other Attributes --
8989 ----------------------
8991 -- For other attributes, resolve prefix unless it is a type. If
8992 -- the attribute reference itself is a type name ('Base and 'Class)
8993 -- then this is only legal within a task or protected record.
8996 if not Is_Entity_Name (P)
8997 or else not Is_Type (Entity (P))
9002 -- If the attribute reference itself is a type name ('Base,
9003 -- 'Class) then this is only legal within a task or protected
9004 -- record. What is this all about ???
9006 if Is_Entity_Name (N)
9007 and then Is_Type (Entity (N))
9009 if Is_Concurrent_Type (Entity (N))
9010 and then In_Open_Scopes (Entity (P))
9015 ("invalid use of subtype name in expression or call", N);
9019 -- For attributes whose argument may be a string, complete
9020 -- resolution of argument now. This avoids premature expansion
9021 -- (and the creation of transient scopes) before the attribute
9022 -- reference is resolved.
9025 when Attribute_Value =>
9026 Resolve (First (Expressions (N)), Standard_String);
9028 when Attribute_Wide_Value =>
9029 Resolve (First (Expressions (N)), Standard_Wide_String);
9031 when Attribute_Wide_Wide_Value =>
9032 Resolve (First (Expressions (N)), Standard_Wide_Wide_String);
9034 when others => null;
9037 -- If the prefix of the attribute is a class-wide type then it
9038 -- will be expanded into a dispatching call to a predefined
9039 -- primitive. Therefore we must check for potential violation
9040 -- of such restriction.
9042 if Is_Class_Wide_Type (Etype (P)) then
9043 Check_Restriction (No_Dispatching_Calls, N);
9047 -- Normally the Freezing is done by Resolve but sometimes the Prefix
9048 -- is not resolved, in which case the freezing must be done now.
9050 Freeze_Expression (P);
9052 -- Finally perform static evaluation on the attribute reference
9055 end Resolve_Attribute;
9057 --------------------------------
9058 -- Stream_Attribute_Available --
9059 --------------------------------
9061 function Stream_Attribute_Available
9063 Nam : TSS_Name_Type;
9064 Partial_View : Node_Id := Empty) return Boolean
9066 Etyp : Entity_Id := Typ;
9068 -- Start of processing for Stream_Attribute_Available
9071 -- We need some comments in this body ???
9073 if Has_Stream_Attribute_Definition (Typ, Nam) then
9077 if Is_Class_Wide_Type (Typ) then
9078 return not Is_Limited_Type (Typ)
9079 or else Stream_Attribute_Available (Etype (Typ), Nam);
9082 if Nam = TSS_Stream_Input
9083 and then Is_Abstract_Type (Typ)
9084 and then not Is_Class_Wide_Type (Typ)
9089 if not (Is_Limited_Type (Typ)
9090 or else (Present (Partial_View)
9091 and then Is_Limited_Type (Partial_View)))
9096 -- In Ada 2005, Input can invoke Read, and Output can invoke Write
9098 if Nam = TSS_Stream_Input
9099 and then Ada_Version >= Ada_2005
9100 and then Stream_Attribute_Available (Etyp, TSS_Stream_Read)
9104 elsif Nam = TSS_Stream_Output
9105 and then Ada_Version >= Ada_2005
9106 and then Stream_Attribute_Available (Etyp, TSS_Stream_Write)
9111 -- Case of Read and Write: check for attribute definition clause that
9112 -- applies to an ancestor type.
9114 while Etype (Etyp) /= Etyp loop
9115 Etyp := Etype (Etyp);
9117 if Has_Stream_Attribute_Definition (Etyp, Nam) then
9122 if Ada_Version < Ada_2005 then
9124 -- In Ada 95 mode, also consider a non-visible definition
9127 Btyp : constant Entity_Id := Implementation_Base_Type (Typ);
9130 and then Stream_Attribute_Available
9131 (Btyp, Nam, Partial_View => Typ);
9136 end Stream_Attribute_Available;