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.
267 -- Set the flag only if the reference is in the main code unit. Same
268 -- restriction when resolving 'Value; otherwise an improperly set
269 -- reference when analyzing an inlined body will lose a proper warning
270 -- on a useless with_clause.
272 procedure Check_Fixed_Point_Type;
273 -- Verify that prefix of attribute N is a fixed type
275 procedure Check_Fixed_Point_Type_0;
276 -- Verify that prefix of attribute N is a fixed type and that
277 -- no attribute expressions are present
279 procedure Check_Floating_Point_Type;
280 -- Verify that prefix of attribute N is a float type
282 procedure Check_Floating_Point_Type_0;
283 -- Verify that prefix of attribute N is a float type and that
284 -- no attribute expressions are present
286 procedure Check_Floating_Point_Type_1;
287 -- Verify that prefix of attribute N is a float type and that
288 -- exactly one attribute expression is present
290 procedure Check_Floating_Point_Type_2;
291 -- Verify that prefix of attribute N is a float type and that
292 -- two attribute expressions are present
294 procedure Legal_Formal_Attribute;
295 -- Common processing for attributes Definite and Has_Discriminants.
296 -- Checks that prefix is generic indefinite formal type.
298 procedure Check_SPARK_Restriction_On_Attribute;
299 -- Issue an error in formal mode because attribute N is allowed
301 procedure Check_Integer_Type;
302 -- Verify that prefix of attribute N is an integer type
304 procedure Check_Modular_Integer_Type;
305 -- Verify that prefix of attribute N is a modular integer type
307 procedure Check_Not_CPP_Type;
308 -- Check that P (the prefix of the attribute) is not an CPP type
309 -- for which no Ada predefined primitive is available.
311 procedure Check_Not_Incomplete_Type;
312 -- Check that P (the prefix of the attribute) is not an incomplete
313 -- type or a private type for which no full view has been given.
315 procedure Check_Object_Reference (P : Node_Id);
316 -- Check that P (the prefix of the attribute) is an object reference
318 procedure Check_Program_Unit;
319 -- Verify that prefix of attribute N is a program unit
321 procedure Check_Real_Type;
322 -- Verify that prefix of attribute N is fixed or float type
324 procedure Check_Scalar_Type;
325 -- Verify that prefix of attribute N is a scalar type
327 procedure Check_Standard_Prefix;
328 -- Verify that prefix of attribute N is package Standard
330 procedure Check_Stream_Attribute (Nam : TSS_Name_Type);
331 -- Validity checking for stream attribute. Nam is the TSS name of the
332 -- corresponding possible defined attribute function (e.g. for the
333 -- Read attribute, Nam will be TSS_Stream_Read).
335 procedure Check_PolyORB_Attribute;
336 -- Validity checking for PolyORB/DSA attribute
338 procedure Check_Task_Prefix;
339 -- Verify that prefix of attribute N is a task or task type
341 procedure Check_Type;
342 -- Verify that the prefix of attribute N is a type
344 procedure Check_Unit_Name (Nod : Node_Id);
345 -- Check that Nod is of the form of a library unit name, i.e that
346 -- it is an identifier, or a selected component whose prefix is
347 -- itself of the form of a library unit name. Note that this is
348 -- quite different from Check_Program_Unit, since it only checks
349 -- the syntactic form of the name, not the semantic identity. This
350 -- is because it is used with attributes (Elab_Body, Elab_Spec,
351 -- UET_Address and Elaborated) which can refer to non-visible unit.
353 procedure Error_Attr (Msg : String; Error_Node : Node_Id);
354 pragma No_Return (Error_Attr);
355 procedure Error_Attr;
356 pragma No_Return (Error_Attr);
357 -- Posts error using Error_Msg_N at given node, sets type of attribute
358 -- node to Any_Type, and then raises Bad_Attribute to avoid any further
359 -- semantic processing. The message typically contains a % insertion
360 -- character which is replaced by the attribute name. The call with
361 -- no arguments is used when the caller has already generated the
362 -- required error messages.
364 procedure Error_Attr_P (Msg : String);
365 pragma No_Return (Error_Attr);
366 -- Like Error_Attr, but error is posted at the start of the prefix
368 procedure Standard_Attribute (Val : Int);
369 -- Used to process attributes whose prefix is package Standard which
370 -- yield values of type Universal_Integer. The attribute reference
371 -- node is rewritten with an integer literal of the given value.
373 procedure Unexpected_Argument (En : Node_Id);
374 -- Signal unexpected attribute argument (En is the argument)
376 procedure Validate_Non_Static_Attribute_Function_Call;
377 -- Called when processing an attribute that is a function call to a
378 -- non-static function, i.e. an attribute function that either takes
379 -- non-scalar arguments or returns a non-scalar result. Verifies that
380 -- such a call does not appear in a preelaborable context.
382 ------------------------------
383 -- Analyze_Access_Attribute --
384 ------------------------------
386 procedure Analyze_Access_Attribute is
387 Acc_Type : Entity_Id;
392 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id;
393 -- Build an access-to-object type whose designated type is DT,
394 -- and whose Ekind is appropriate to the attribute type. The
395 -- type that is constructed is returned as the result.
397 procedure Build_Access_Subprogram_Type (P : Node_Id);
398 -- Build an access to subprogram whose designated type is the type of
399 -- the prefix. If prefix is overloaded, so is the node itself. The
400 -- result is stored in Acc_Type.
402 function OK_Self_Reference return Boolean;
403 -- An access reference whose prefix is a type can legally appear
404 -- within an aggregate, where it is obtained by expansion of
405 -- a defaulted aggregate. The enclosing aggregate that contains
406 -- the self-referenced is flagged so that the self-reference can
407 -- be expanded into a reference to the target object (see exp_aggr).
409 ------------------------------
410 -- Build_Access_Object_Type --
411 ------------------------------
413 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id is
414 Typ : constant Entity_Id :=
416 (E_Access_Attribute_Type, Current_Scope, Loc, 'A');
418 Set_Etype (Typ, Typ);
420 Set_Associated_Node_For_Itype (Typ, N);
421 Set_Directly_Designated_Type (Typ, DT);
423 end Build_Access_Object_Type;
425 ----------------------------------
426 -- Build_Access_Subprogram_Type --
427 ----------------------------------
429 procedure Build_Access_Subprogram_Type (P : Node_Id) is
430 Index : Interp_Index;
433 procedure Check_Local_Access (E : Entity_Id);
434 -- Deal with possible access to local subprogram. If we have such
435 -- an access, we set a flag to kill all tracked values on any call
436 -- because this access value may be passed around, and any called
437 -- code might use it to access a local procedure which clobbers a
438 -- tracked value. If the scope is a loop or block, indicate that
439 -- value tracking is disabled for the enclosing subprogram.
441 function Get_Kind (E : Entity_Id) return Entity_Kind;
442 -- Distinguish between access to regular/protected subprograms
444 ------------------------
445 -- Check_Local_Access --
446 ------------------------
448 procedure Check_Local_Access (E : Entity_Id) is
450 if not Is_Library_Level_Entity (E) then
451 Set_Suppress_Value_Tracking_On_Call (Current_Scope);
452 Set_Suppress_Value_Tracking_On_Call
453 (Nearest_Dynamic_Scope (Current_Scope));
455 end Check_Local_Access;
461 function Get_Kind (E : Entity_Id) return Entity_Kind is
463 if Convention (E) = Convention_Protected then
464 return E_Access_Protected_Subprogram_Type;
466 return E_Access_Subprogram_Type;
470 -- Start of processing for Build_Access_Subprogram_Type
473 -- In the case of an access to subprogram, use the name of the
474 -- subprogram itself as the designated type. Type-checking in
475 -- this case compares the signatures of the designated types.
477 -- Note: This fragment of the tree is temporarily malformed
478 -- because the correct tree requires an E_Subprogram_Type entity
479 -- as the designated type. In most cases this designated type is
480 -- later overridden by the semantics with the type imposed by the
481 -- context during the resolution phase. In the specific case of
482 -- the expression Address!(Prim'Unrestricted_Access), used to
483 -- initialize slots of dispatch tables, this work will be done by
484 -- the expander (see Exp_Aggr).
486 -- The reason to temporarily add this kind of node to the tree
487 -- instead of a proper E_Subprogram_Type itype, is the following:
488 -- in case of errors found in the source file we report better
489 -- error messages. For example, instead of generating the
492 -- "expected access to subprogram with profile
493 -- defined at line X"
495 -- we currently generate:
497 -- "expected access to function Z defined at line X"
499 Set_Etype (N, Any_Type);
501 if not Is_Overloaded (P) then
502 Check_Local_Access (Entity (P));
504 if not Is_Intrinsic_Subprogram (Entity (P)) then
505 Acc_Type := Create_Itype (Get_Kind (Entity (P)), N);
506 Set_Is_Public (Acc_Type, False);
507 Set_Etype (Acc_Type, Acc_Type);
508 Set_Convention (Acc_Type, Convention (Entity (P)));
509 Set_Directly_Designated_Type (Acc_Type, Entity (P));
510 Set_Etype (N, Acc_Type);
511 Freeze_Before (N, Acc_Type);
515 Get_First_Interp (P, Index, It);
516 while Present (It.Nam) loop
517 Check_Local_Access (It.Nam);
519 if not Is_Intrinsic_Subprogram (It.Nam) then
520 Acc_Type := Create_Itype (Get_Kind (It.Nam), N);
521 Set_Is_Public (Acc_Type, False);
522 Set_Etype (Acc_Type, Acc_Type);
523 Set_Convention (Acc_Type, Convention (It.Nam));
524 Set_Directly_Designated_Type (Acc_Type, It.Nam);
525 Add_One_Interp (N, Acc_Type, Acc_Type);
526 Freeze_Before (N, Acc_Type);
529 Get_Next_Interp (Index, It);
533 -- Cannot be applied to intrinsic. Looking at the tests above,
534 -- the only way Etype (N) can still be set to Any_Type is if
535 -- Is_Intrinsic_Subprogram was True for some referenced entity.
537 if Etype (N) = Any_Type then
538 Error_Attr_P ("prefix of % attribute cannot be intrinsic");
540 end Build_Access_Subprogram_Type;
542 ----------------------
543 -- OK_Self_Reference --
544 ----------------------
546 function OK_Self_Reference return Boolean is
553 (Nkind (Par) = N_Component_Association
554 or else Nkind (Par) in N_Subexpr)
556 if Nkind_In (Par, N_Aggregate, N_Extension_Aggregate) then
557 if Etype (Par) = Typ then
558 Set_Has_Self_Reference (Par);
566 -- No enclosing aggregate, or not a self-reference
569 end OK_Self_Reference;
571 -- Start of processing for Analyze_Access_Attribute
574 Check_SPARK_Restriction_On_Attribute;
577 if Nkind (P) = N_Character_Literal then
579 ("prefix of % attribute cannot be enumeration literal");
582 -- Case of access to subprogram
584 if Is_Entity_Name (P)
585 and then Is_Overloadable (Entity (P))
587 if Has_Pragma_Inline_Always (Entity (P)) then
589 ("prefix of % attribute cannot be Inline_Always subprogram");
592 if Aname = Name_Unchecked_Access then
593 Error_Attr ("attribute% cannot be applied to a subprogram", P);
596 -- Issue an error if the prefix denotes an eliminated subprogram
598 Check_For_Eliminated_Subprogram (P, Entity (P));
600 -- Check for obsolescent subprogram reference
602 Check_Obsolescent_2005_Entity (Entity (P), P);
604 -- Build the appropriate subprogram type
606 Build_Access_Subprogram_Type (P);
608 -- For P'Access or P'Unrestricted_Access, where P is a nested
609 -- subprogram, we might be passing P to another subprogram (but we
610 -- don't check that here), which might call P. P could modify
611 -- local variables, so we need to kill current values. It is
612 -- important not to do this for library-level subprograms, because
613 -- Kill_Current_Values is very inefficient in the case of library
614 -- level packages with lots of tagged types.
616 if Is_Library_Level_Entity (Entity (Prefix (N))) then
619 -- Do not kill values on nodes initializing dispatch tables
620 -- slots. The construct Prim_Ptr!(Prim'Unrestricted_Access)
621 -- is currently generated by the expander only for this
622 -- purpose. Done to keep the quality of warnings currently
623 -- generated by the compiler (otherwise any declaration of
624 -- a tagged type cleans constant indications from its scope).
626 elsif Nkind (Parent (N)) = N_Unchecked_Type_Conversion
627 and then (Etype (Parent (N)) = RTE (RE_Prim_Ptr)
629 Etype (Parent (N)) = RTE (RE_Size_Ptr))
630 and then Is_Dispatching_Operation
631 (Directly_Designated_Type (Etype (N)))
641 -- Component is an operation of a protected type
643 elsif Nkind (P) = N_Selected_Component
644 and then Is_Overloadable (Entity (Selector_Name (P)))
646 if Ekind (Entity (Selector_Name (P))) = E_Entry then
647 Error_Attr_P ("prefix of % attribute must be subprogram");
650 Build_Access_Subprogram_Type (Selector_Name (P));
654 -- Deal with incorrect reference to a type, but note that some
655 -- accesses are allowed: references to the current type instance,
656 -- or in Ada 2005 self-referential pointer in a default-initialized
659 if Is_Entity_Name (P) then
662 -- The reference may appear in an aggregate that has been expanded
663 -- into a loop. Locate scope of type definition, if any.
665 Scop := Current_Scope;
666 while Ekind (Scop) = E_Loop loop
667 Scop := Scope (Scop);
670 if Is_Type (Typ) then
672 -- OK if we are within the scope of a limited type
673 -- let's mark the component as having per object constraint
675 if Is_Anonymous_Tagged_Base (Scop, Typ) then
683 Q : Node_Id := Parent (N);
687 and then Nkind (Q) /= N_Component_Declaration
693 Set_Has_Per_Object_Constraint
694 (Defining_Identifier (Q), True);
698 if Nkind (P) = N_Expanded_Name then
700 ("current instance prefix must be a direct name", P);
703 -- If a current instance attribute appears in a component
704 -- constraint it must appear alone; other contexts (spec-
705 -- expressions, within a task body) are not subject to this
708 if not In_Spec_Expression
709 and then not Has_Completion (Scop)
711 Nkind_In (Parent (N), N_Discriminant_Association,
712 N_Index_Or_Discriminant_Constraint)
715 ("current instance attribute must appear alone", N);
718 if Is_CPP_Class (Root_Type (Typ)) then
720 ("?current instance unsupported for derivations of "
721 & "'C'P'P types", N);
724 -- OK if we are in initialization procedure for the type
725 -- in question, in which case the reference to the type
726 -- is rewritten as a reference to the current object.
728 elsif Ekind (Scop) = E_Procedure
729 and then Is_Init_Proc (Scop)
730 and then Etype (First_Formal (Scop)) = Typ
733 Make_Attribute_Reference (Loc,
734 Prefix => Make_Identifier (Loc, Name_uInit),
735 Attribute_Name => Name_Unrestricted_Access));
739 -- OK if a task type, this test needs sharpening up ???
741 elsif Is_Task_Type (Typ) then
744 -- OK if self-reference in an aggregate in Ada 2005, and
745 -- the reference comes from a copied default expression.
747 -- Note that we check legality of self-reference even if the
748 -- expression comes from source, e.g. when a single component
749 -- association in an aggregate has a box association.
751 elsif Ada_Version >= Ada_2005
752 and then OK_Self_Reference
756 -- OK if reference to current instance of a protected object
758 elsif Is_Protected_Self_Reference (P) then
761 -- Otherwise we have an error case
764 Error_Attr ("% attribute cannot be applied to type", P);
770 -- If we fall through, we have a normal access to object case.
771 -- Unrestricted_Access is legal wherever an allocator would be
772 -- legal, so its Etype is set to E_Allocator. The expected type
773 -- of the other attributes is a general access type, and therefore
774 -- we label them with E_Access_Attribute_Type.
776 if not Is_Overloaded (P) then
777 Acc_Type := Build_Access_Object_Type (P_Type);
778 Set_Etype (N, Acc_Type);
781 Index : Interp_Index;
784 Set_Etype (N, Any_Type);
785 Get_First_Interp (P, Index, It);
786 while Present (It.Typ) loop
787 Acc_Type := Build_Access_Object_Type (It.Typ);
788 Add_One_Interp (N, Acc_Type, Acc_Type);
789 Get_Next_Interp (Index, It);
794 -- Special cases when we can find a prefix that is an entity name
803 if Is_Entity_Name (PP) then
806 -- If we have an access to an object, and the attribute
807 -- comes from source, then set the object as potentially
808 -- source modified. We do this because the resulting access
809 -- pointer can be used to modify the variable, and we might
810 -- not detect this, leading to some junk warnings.
812 Set_Never_Set_In_Source (Ent, False);
814 -- Mark entity as address taken, and kill current values
816 Set_Address_Taken (Ent);
817 Kill_Current_Values (Ent);
820 elsif Nkind_In (PP, N_Selected_Component,
831 -- Check for aliased view unless unrestricted case. We allow a
832 -- nonaliased prefix when within an instance because the prefix may
833 -- have been a tagged formal object, which is defined to be aliased
834 -- even when the actual might not be (other instance cases will have
835 -- been caught in the generic). Similarly, within an inlined body we
836 -- know that the attribute is legal in the original subprogram, and
837 -- therefore legal in the expansion.
839 if Aname /= Name_Unrestricted_Access
840 and then not Is_Aliased_View (P)
841 and then not In_Instance
842 and then not In_Inlined_Body
844 Error_Attr_P ("prefix of % attribute must be aliased");
845 Check_No_Implicit_Aliasing (P);
847 end Analyze_Access_Attribute;
849 ---------------------------------
850 -- Bad_Attribute_For_Predicate --
851 ---------------------------------
853 procedure Bad_Attribute_For_Predicate is
855 if Is_Scalar_Type (P_Type)
856 and then Comes_From_Source (N)
858 Error_Msg_Name_1 := Aname;
859 Bad_Predicated_Subtype_Use
860 ("type& has predicates, attribute % not allowed", N, P_Type);
862 end Bad_Attribute_For_Predicate;
864 --------------------------------
865 -- Check_Array_Or_Scalar_Type --
866 --------------------------------
868 procedure Check_Array_Or_Scalar_Type is
872 -- Dimension number for array attributes
875 -- Case of string literal or string literal subtype. These cases
876 -- cannot arise from legal Ada code, but the expander is allowed
877 -- to generate them. They require special handling because string
878 -- literal subtypes do not have standard bounds (the whole idea
879 -- of these subtypes is to avoid having to generate the bounds)
881 if Ekind (P_Type) = E_String_Literal_Subtype then
882 Set_Etype (N, Etype (First_Index (P_Base_Type)));
887 elsif Is_Scalar_Type (P_Type) then
891 Error_Attr ("invalid argument in % attribute", E1);
893 Set_Etype (N, P_Base_Type);
897 -- The following is a special test to allow 'First to apply to
898 -- private scalar types if the attribute comes from generated
899 -- code. This occurs in the case of Normalize_Scalars code.
901 elsif Is_Private_Type (P_Type)
902 and then Present (Full_View (P_Type))
903 and then Is_Scalar_Type (Full_View (P_Type))
904 and then not Comes_From_Source (N)
906 Set_Etype (N, Implementation_Base_Type (P_Type));
908 -- Array types other than string literal subtypes handled above
913 -- We know prefix is an array type, or the name of an array
914 -- object, and that the expression, if present, is static
915 -- and within the range of the dimensions of the type.
917 pragma Assert (Is_Array_Type (P_Type));
918 Index := First_Index (P_Base_Type);
922 -- First dimension assumed
924 Set_Etype (N, Base_Type (Etype (Index)));
927 D := UI_To_Int (Intval (E1));
929 for J in 1 .. D - 1 loop
933 Set_Etype (N, Base_Type (Etype (Index)));
934 Set_Etype (E1, Standard_Integer);
937 end Check_Array_Or_Scalar_Type;
939 ----------------------
940 -- Check_Array_Type --
941 ----------------------
943 procedure Check_Array_Type is
945 -- Dimension number for array attributes
948 -- If the type is a string literal type, then this must be generated
949 -- internally, and no further check is required on its legality.
951 if Ekind (P_Type) = E_String_Literal_Subtype then
954 -- If the type is a composite, it is an illegal aggregate, no point
957 elsif P_Type = Any_Composite then
961 -- Normal case of array type or subtype
963 Check_Either_E0_Or_E1;
966 if Is_Array_Type (P_Type) then
967 if not Is_Constrained (P_Type)
968 and then Is_Entity_Name (P)
969 and then Is_Type (Entity (P))
971 -- Note: we do not call Error_Attr here, since we prefer to
972 -- continue, using the relevant index type of the array,
973 -- even though it is unconstrained. This gives better error
974 -- recovery behavior.
976 Error_Msg_Name_1 := Aname;
978 ("prefix for % attribute must be constrained array", P);
981 D := Number_Dimensions (P_Type);
984 if Is_Private_Type (P_Type) then
985 Error_Attr_P ("prefix for % attribute may not be private type");
987 elsif Is_Access_Type (P_Type)
988 and then Is_Array_Type (Designated_Type (P_Type))
989 and then Is_Entity_Name (P)
990 and then Is_Type (Entity (P))
992 Error_Attr_P ("prefix of % attribute cannot be access type");
994 elsif Attr_Id = Attribute_First
996 Attr_Id = Attribute_Last
998 Error_Attr ("invalid prefix for % attribute", P);
1001 Error_Attr_P ("prefix for % attribute must be array");
1005 if Present (E1) then
1006 Resolve (E1, Any_Integer);
1007 Set_Etype (E1, Standard_Integer);
1009 if not Is_Static_Expression (E1)
1010 or else Raises_Constraint_Error (E1)
1012 Flag_Non_Static_Expr
1013 ("expression for dimension must be static!", E1);
1016 elsif UI_To_Int (Expr_Value (E1)) > D
1017 or else UI_To_Int (Expr_Value (E1)) < 1
1019 Error_Attr ("invalid dimension number for array type", E1);
1023 if (Style_Check and Style_Check_Array_Attribute_Index)
1024 and then Comes_From_Source (N)
1026 Style.Check_Array_Attribute_Index (N, E1, D);
1028 end Check_Array_Type;
1030 -------------------------
1031 -- Check_Asm_Attribute --
1032 -------------------------
1034 procedure Check_Asm_Attribute is
1039 -- Check first argument is static string expression
1041 Analyze_And_Resolve (E1, Standard_String);
1043 if Etype (E1) = Any_Type then
1046 elsif not Is_OK_Static_Expression (E1) then
1047 Flag_Non_Static_Expr
1048 ("constraint argument must be static string expression!", E1);
1052 -- Check second argument is right type
1054 Analyze_And_Resolve (E2, Entity (P));
1056 -- Note: that is all we need to do, we don't need to check
1057 -- that it appears in a correct context. The Ada type system
1058 -- will do that for us.
1060 end Check_Asm_Attribute;
1062 ---------------------
1063 -- Check_Component --
1064 ---------------------
1066 procedure Check_Component is
1070 if Nkind (P) /= N_Selected_Component
1072 (Ekind (Entity (Selector_Name (P))) /= E_Component
1074 Ekind (Entity (Selector_Name (P))) /= E_Discriminant)
1076 Error_Attr_P ("prefix for % attribute must be selected component");
1078 end Check_Component;
1080 ------------------------------------
1081 -- Check_Decimal_Fixed_Point_Type --
1082 ------------------------------------
1084 procedure Check_Decimal_Fixed_Point_Type is
1088 if not Is_Decimal_Fixed_Point_Type (P_Type) then
1089 Error_Attr_P ("prefix of % attribute must be decimal type");
1091 end Check_Decimal_Fixed_Point_Type;
1093 -----------------------
1094 -- Check_Dereference --
1095 -----------------------
1097 procedure Check_Dereference is
1100 -- Case of a subtype mark
1102 if Is_Entity_Name (P)
1103 and then Is_Type (Entity (P))
1108 -- Case of an expression
1112 if Is_Access_Type (P_Type) then
1114 -- If there is an implicit dereference, then we must freeze
1115 -- the designated type of the access type, since the type of
1116 -- the referenced array is this type (see AI95-00106).
1118 -- As done elsewhere, freezing must not happen when pre-analyzing
1119 -- a pre- or postcondition or a default value for an object or
1120 -- for a formal parameter.
1122 if not In_Spec_Expression then
1123 Freeze_Before (N, Designated_Type (P_Type));
1127 Make_Explicit_Dereference (Sloc (P),
1128 Prefix => Relocate_Node (P)));
1130 Analyze_And_Resolve (P);
1131 P_Type := Etype (P);
1133 if P_Type = Any_Type then
1134 raise Bad_Attribute;
1137 P_Base_Type := Base_Type (P_Type);
1139 end Check_Dereference;
1141 -------------------------
1142 -- Check_Discrete_Type --
1143 -------------------------
1145 procedure Check_Discrete_Type is
1149 if not Is_Discrete_Type (P_Type) then
1150 Error_Attr_P ("prefix of % attribute must be discrete type");
1152 end Check_Discrete_Type;
1158 procedure Check_E0 is
1160 if Present (E1) then
1161 Unexpected_Argument (E1);
1169 procedure Check_E1 is
1171 Check_Either_E0_Or_E1;
1175 -- Special-case attributes that are functions and that appear as
1176 -- the prefix of another attribute. Error is posted on parent.
1178 if Nkind (Parent (N)) = N_Attribute_Reference
1179 and then (Attribute_Name (Parent (N)) = Name_Address
1181 Attribute_Name (Parent (N)) = Name_Code_Address
1183 Attribute_Name (Parent (N)) = Name_Access)
1185 Error_Msg_Name_1 := Attribute_Name (Parent (N));
1186 Error_Msg_N ("illegal prefix for % attribute", Parent (N));
1187 Set_Etype (Parent (N), Any_Type);
1188 Set_Entity (Parent (N), Any_Type);
1189 raise Bad_Attribute;
1192 Error_Attr ("missing argument for % attribute", N);
1201 procedure Check_E2 is
1204 Error_Attr ("missing arguments for % attribute (2 required)", N);
1206 Error_Attr ("missing argument for % attribute (2 required)", N);
1210 ---------------------------
1211 -- Check_Either_E0_Or_E1 --
1212 ---------------------------
1214 procedure Check_Either_E0_Or_E1 is
1216 if Present (E2) then
1217 Unexpected_Argument (E2);
1219 end Check_Either_E0_Or_E1;
1221 ----------------------
1222 -- Check_Enum_Image --
1223 ----------------------
1225 procedure Check_Enum_Image is
1229 -- When an enumeration type appears in an attribute reference, all
1230 -- literals of the type are marked as referenced. This must only be
1231 -- done if the attribute reference appears in the current source.
1232 -- Otherwise the information on references may differ between a
1233 -- normal compilation and one that performs inlining.
1235 if Is_Enumeration_Type (P_Base_Type)
1236 and then In_Extended_Main_Code_Unit (N)
1238 Lit := First_Literal (P_Base_Type);
1239 while Present (Lit) loop
1240 Set_Referenced (Lit);
1244 end Check_Enum_Image;
1246 ----------------------------
1247 -- Check_Fixed_Point_Type --
1248 ----------------------------
1250 procedure Check_Fixed_Point_Type is
1254 if not Is_Fixed_Point_Type (P_Type) then
1255 Error_Attr_P ("prefix of % attribute must be fixed point type");
1257 end Check_Fixed_Point_Type;
1259 ------------------------------
1260 -- Check_Fixed_Point_Type_0 --
1261 ------------------------------
1263 procedure Check_Fixed_Point_Type_0 is
1265 Check_Fixed_Point_Type;
1267 end Check_Fixed_Point_Type_0;
1269 -------------------------------
1270 -- Check_Floating_Point_Type --
1271 -------------------------------
1273 procedure Check_Floating_Point_Type is
1277 if not Is_Floating_Point_Type (P_Type) then
1278 Error_Attr_P ("prefix of % attribute must be float type");
1280 end Check_Floating_Point_Type;
1282 ---------------------------------
1283 -- Check_Floating_Point_Type_0 --
1284 ---------------------------------
1286 procedure Check_Floating_Point_Type_0 is
1288 Check_Floating_Point_Type;
1290 end Check_Floating_Point_Type_0;
1292 ---------------------------------
1293 -- Check_Floating_Point_Type_1 --
1294 ---------------------------------
1296 procedure Check_Floating_Point_Type_1 is
1298 Check_Floating_Point_Type;
1300 end Check_Floating_Point_Type_1;
1302 ---------------------------------
1303 -- Check_Floating_Point_Type_2 --
1304 ---------------------------------
1306 procedure Check_Floating_Point_Type_2 is
1308 Check_Floating_Point_Type;
1310 end Check_Floating_Point_Type_2;
1312 ------------------------
1313 -- Check_Integer_Type --
1314 ------------------------
1316 procedure Check_Integer_Type is
1320 if not Is_Integer_Type (P_Type) then
1321 Error_Attr_P ("prefix of % attribute must be integer type");
1323 end Check_Integer_Type;
1325 --------------------------------
1326 -- Check_Modular_Integer_Type --
1327 --------------------------------
1329 procedure Check_Modular_Integer_Type is
1333 if not Is_Modular_Integer_Type (P_Type) then
1335 ("prefix of % attribute must be modular integer type");
1337 end Check_Modular_Integer_Type;
1339 ------------------------
1340 -- Check_Not_CPP_Type --
1341 ------------------------
1343 procedure Check_Not_CPP_Type is
1345 if Is_Tagged_Type (Etype (P))
1346 and then Convention (Etype (P)) = Convention_CPP
1347 and then Is_CPP_Class (Root_Type (Etype (P)))
1350 ("invalid use of % attribute with 'C'P'P tagged type");
1352 end Check_Not_CPP_Type;
1354 -------------------------------
1355 -- Check_Not_Incomplete_Type --
1356 -------------------------------
1358 procedure Check_Not_Incomplete_Type is
1363 -- Ada 2005 (AI-50217, AI-326): If the prefix is an explicit
1364 -- dereference we have to check wrong uses of incomplete types
1365 -- (other wrong uses are checked at their freezing point).
1367 -- Example 1: Limited-with
1369 -- limited with Pkg;
1371 -- type Acc is access Pkg.T;
1373 -- S : Integer := X.all'Size; -- ERROR
1376 -- Example 2: Tagged incomplete
1378 -- type T is tagged;
1379 -- type Acc is access all T;
1381 -- S : constant Integer := X.all'Size; -- ERROR
1382 -- procedure Q (Obj : Integer := X.all'Alignment); -- ERROR
1384 if Ada_Version >= Ada_2005
1385 and then Nkind (P) = N_Explicit_Dereference
1388 while Nkind (E) = N_Explicit_Dereference loop
1394 if From_With_Type (Typ) then
1396 ("prefix of % attribute cannot be an incomplete type");
1399 if Is_Access_Type (Typ) then
1400 Typ := Directly_Designated_Type (Typ);
1403 if Is_Class_Wide_Type (Typ) then
1404 Typ := Root_Type (Typ);
1407 -- A legal use of a shadow entity occurs only when the unit
1408 -- where the non-limited view resides is imported via a regular
1409 -- with clause in the current body. Such references to shadow
1410 -- entities may occur in subprogram formals.
1412 if Is_Incomplete_Type (Typ)
1413 and then From_With_Type (Typ)
1414 and then Present (Non_Limited_View (Typ))
1415 and then Is_Legal_Shadow_Entity_In_Body (Typ)
1417 Typ := Non_Limited_View (Typ);
1420 if Ekind (Typ) = E_Incomplete_Type
1421 and then No (Full_View (Typ))
1424 ("prefix of % attribute cannot be an incomplete type");
1429 if not Is_Entity_Name (P)
1430 or else not Is_Type (Entity (P))
1431 or else In_Spec_Expression
1435 Check_Fully_Declared (P_Type, P);
1437 end Check_Not_Incomplete_Type;
1439 ----------------------------
1440 -- Check_Object_Reference --
1441 ----------------------------
1443 procedure Check_Object_Reference (P : Node_Id) is
1447 -- If we need an object, and we have a prefix that is the name of
1448 -- a function entity, convert it into a function call.
1450 if Is_Entity_Name (P)
1451 and then Ekind (Entity (P)) = E_Function
1453 Rtyp := Etype (Entity (P));
1456 Make_Function_Call (Sloc (P),
1457 Name => Relocate_Node (P)));
1459 Analyze_And_Resolve (P, Rtyp);
1461 -- Otherwise we must have an object reference
1463 elsif not Is_Object_Reference (P) then
1464 Error_Attr_P ("prefix of % attribute must be object");
1466 end Check_Object_Reference;
1468 ----------------------------
1469 -- Check_PolyORB_Attribute --
1470 ----------------------------
1472 procedure Check_PolyORB_Attribute is
1474 Validate_Non_Static_Attribute_Function_Call;
1479 if Get_PCS_Name /= Name_PolyORB_DSA then
1481 ("attribute% requires the 'Poly'O'R'B 'P'C'S", N);
1483 end Check_PolyORB_Attribute;
1485 ------------------------
1486 -- Check_Program_Unit --
1487 ------------------------
1489 procedure Check_Program_Unit is
1491 if Is_Entity_Name (P) then
1493 K : constant Entity_Kind := Ekind (Entity (P));
1494 T : constant Entity_Id := Etype (Entity (P));
1497 if K in Subprogram_Kind
1498 or else K in Task_Kind
1499 or else K in Protected_Kind
1500 or else K = E_Package
1501 or else K in Generic_Unit_Kind
1502 or else (K = E_Variable
1506 Is_Protected_Type (T)))
1513 Error_Attr_P ("prefix of % attribute must be program unit");
1514 end Check_Program_Unit;
1516 ---------------------
1517 -- Check_Real_Type --
1518 ---------------------
1520 procedure Check_Real_Type is
1524 if not Is_Real_Type (P_Type) then
1525 Error_Attr_P ("prefix of % attribute must be real type");
1527 end Check_Real_Type;
1529 -----------------------
1530 -- Check_Scalar_Type --
1531 -----------------------
1533 procedure Check_Scalar_Type is
1537 if not Is_Scalar_Type (P_Type) then
1538 Error_Attr_P ("prefix of % attribute must be scalar type");
1540 end Check_Scalar_Type;
1542 ------------------------------------------
1543 -- Check_SPARK_Restriction_On_Attribute --
1544 ------------------------------------------
1546 procedure Check_SPARK_Restriction_On_Attribute is
1548 Error_Msg_Name_1 := Aname;
1549 Check_SPARK_Restriction ("attribute % is not allowed", P);
1550 end Check_SPARK_Restriction_On_Attribute;
1552 ---------------------------
1553 -- Check_Standard_Prefix --
1554 ---------------------------
1556 procedure Check_Standard_Prefix is
1560 if Nkind (P) /= N_Identifier
1561 or else Chars (P) /= Name_Standard
1563 Error_Attr ("only allowed prefix for % attribute is Standard", P);
1565 end Check_Standard_Prefix;
1567 ----------------------------
1568 -- Check_Stream_Attribute --
1569 ----------------------------
1571 procedure Check_Stream_Attribute (Nam : TSS_Name_Type) is
1575 In_Shared_Var_Procs : Boolean;
1576 -- True when compiling the body of System.Shared_Storage.
1577 -- Shared_Var_Procs. For this runtime package (always compiled in
1578 -- GNAT mode), we allow stream attributes references for limited
1579 -- types for the case where shared passive objects are implemented
1580 -- using stream attributes, which is the default in GNAT's persistent
1581 -- storage implementation.
1584 Validate_Non_Static_Attribute_Function_Call;
1586 -- With the exception of 'Input, Stream attributes are procedures,
1587 -- and can only appear at the position of procedure calls. We check
1588 -- for this here, before they are rewritten, to give a more precise
1591 if Nam = TSS_Stream_Input then
1594 elsif Is_List_Member (N)
1595 and then not Nkind_In (Parent (N), N_Procedure_Call_Statement,
1602 ("invalid context for attribute%, which is a procedure", N);
1606 Btyp := Implementation_Base_Type (P_Type);
1608 -- Stream attributes not allowed on limited types unless the
1609 -- attribute reference was generated by the expander (in which
1610 -- case the underlying type will be used, as described in Sinfo),
1611 -- or the attribute was specified explicitly for the type itself
1612 -- or one of its ancestors (taking visibility rules into account if
1613 -- in Ada 2005 mode), or a pragma Stream_Convert applies to Btyp
1614 -- (with no visibility restriction).
1617 Gen_Body : constant Node_Id := Enclosing_Generic_Body (N);
1619 if Present (Gen_Body) then
1620 In_Shared_Var_Procs :=
1621 Is_RTE (Corresponding_Spec (Gen_Body), RE_Shared_Var_Procs);
1623 In_Shared_Var_Procs := False;
1627 if (Comes_From_Source (N)
1628 and then not (In_Shared_Var_Procs or In_Instance))
1629 and then not Stream_Attribute_Available (P_Type, Nam)
1630 and then not Has_Rep_Pragma (Btyp, Name_Stream_Convert)
1632 Error_Msg_Name_1 := Aname;
1634 if Is_Limited_Type (P_Type) then
1636 ("limited type& has no% attribute", P, P_Type);
1637 Explain_Limited_Type (P_Type, P);
1640 ("attribute% for type& is not available", P, P_Type);
1644 -- Check restriction violations
1646 -- First check the No_Streams restriction, which prohibits the use
1647 -- of explicit stream attributes in the source program. We do not
1648 -- prevent the occurrence of stream attributes in generated code,
1649 -- for instance those generated implicitly for dispatching purposes.
1651 if Comes_From_Source (N) then
1652 Check_Restriction (No_Streams, P);
1655 -- AI05-0057: if restriction No_Default_Stream_Attributes is active,
1656 -- it is illegal to use a predefined elementary type stream attribute
1657 -- either by itself, or more importantly as part of the attribute
1658 -- subprogram for a composite type.
1660 if Restriction_Active (No_Default_Stream_Attributes) then
1665 if Nam = TSS_Stream_Input
1667 Nam = TSS_Stream_Read
1670 Type_Without_Stream_Operation (P_Type, TSS_Stream_Read);
1673 Type_Without_Stream_Operation (P_Type, TSS_Stream_Write);
1677 Check_Restriction (No_Default_Stream_Attributes, N);
1680 ("missing user-defined Stream Read or Write for type&",
1682 if not Is_Elementary_Type (P_Type) then
1684 ("\which is a component of type&", N, P_Type);
1690 -- Check special case of Exception_Id and Exception_Occurrence which
1691 -- are not allowed for restriction No_Exception_Registration.
1693 if Restriction_Check_Required (No_Exception_Registration)
1694 and then (Is_RTE (P_Type, RE_Exception_Id)
1696 Is_RTE (P_Type, RE_Exception_Occurrence))
1698 Check_Restriction (No_Exception_Registration, P);
1701 -- Here we must check that the first argument is an access type
1702 -- that is compatible with Ada.Streams.Root_Stream_Type'Class.
1704 Analyze_And_Resolve (E1);
1707 -- Note: the double call to Root_Type here is needed because the
1708 -- root type of a class-wide type is the corresponding type (e.g.
1709 -- X for X'Class, and we really want to go to the root.)
1711 if not Is_Access_Type (Etyp)
1712 or else Root_Type (Root_Type (Designated_Type (Etyp))) /=
1713 RTE (RE_Root_Stream_Type)
1716 ("expected access to Ada.Streams.Root_Stream_Type''Class", E1);
1719 -- Check that the second argument is of the right type if there is
1720 -- one (the Input attribute has only one argument so this is skipped)
1722 if Present (E2) then
1725 if Nam = TSS_Stream_Read
1726 and then not Is_OK_Variable_For_Out_Formal (E2)
1729 ("second argument of % attribute must be a variable", E2);
1732 Resolve (E2, P_Type);
1736 end Check_Stream_Attribute;
1738 -----------------------
1739 -- Check_Task_Prefix --
1740 -----------------------
1742 procedure Check_Task_Prefix is
1746 -- Ada 2005 (AI-345): Attribute 'Terminated can be applied to
1747 -- task interface class-wide types.
1749 if Is_Task_Type (Etype (P))
1750 or else (Is_Access_Type (Etype (P))
1751 and then Is_Task_Type (Designated_Type (Etype (P))))
1752 or else (Ada_Version >= Ada_2005
1753 and then Ekind (Etype (P)) = E_Class_Wide_Type
1754 and then Is_Interface (Etype (P))
1755 and then Is_Task_Interface (Etype (P)))
1760 if Ada_Version >= Ada_2005 then
1762 ("prefix of % attribute must be a task or a task " &
1763 "interface class-wide object");
1766 Error_Attr_P ("prefix of % attribute must be a task");
1769 end Check_Task_Prefix;
1775 -- The possibilities are an entity name denoting a type, or an
1776 -- attribute reference that denotes a type (Base or Class). If
1777 -- the type is incomplete, replace it with its full view.
1779 procedure Check_Type is
1781 if not Is_Entity_Name (P)
1782 or else not Is_Type (Entity (P))
1784 Error_Attr_P ("prefix of % attribute must be a type");
1786 elsif Is_Protected_Self_Reference (P) then
1788 ("prefix of % attribute denotes current instance "
1789 & "(RM 9.4(21/2))");
1791 elsif Ekind (Entity (P)) = E_Incomplete_Type
1792 and then Present (Full_View (Entity (P)))
1794 P_Type := Full_View (Entity (P));
1795 Set_Entity (P, P_Type);
1799 ---------------------
1800 -- Check_Unit_Name --
1801 ---------------------
1803 procedure Check_Unit_Name (Nod : Node_Id) is
1805 if Nkind (Nod) = N_Identifier then
1808 elsif Nkind_In (Nod, N_Selected_Component, N_Expanded_Name) then
1809 Check_Unit_Name (Prefix (Nod));
1811 if Nkind (Selector_Name (Nod)) = N_Identifier then
1816 Error_Attr ("argument for % attribute must be unit name", P);
1817 end Check_Unit_Name;
1823 procedure Error_Attr is
1825 Set_Etype (N, Any_Type);
1826 Set_Entity (N, Any_Type);
1827 raise Bad_Attribute;
1830 procedure Error_Attr (Msg : String; Error_Node : Node_Id) is
1832 Error_Msg_Name_1 := Aname;
1833 Error_Msg_N (Msg, Error_Node);
1841 procedure Error_Attr_P (Msg : String) is
1843 Error_Msg_Name_1 := Aname;
1844 Error_Msg_F (Msg, P);
1848 ----------------------------
1849 -- Legal_Formal_Attribute --
1850 ----------------------------
1852 procedure Legal_Formal_Attribute is
1856 if not Is_Entity_Name (P)
1857 or else not Is_Type (Entity (P))
1859 Error_Attr_P ("prefix of % attribute must be generic type");
1861 elsif Is_Generic_Actual_Type (Entity (P))
1863 or else In_Inlined_Body
1867 elsif Is_Generic_Type (Entity (P)) then
1868 if not Is_Indefinite_Subtype (Entity (P)) then
1870 ("prefix of % attribute must be indefinite generic type");
1875 ("prefix of % attribute must be indefinite generic type");
1878 Set_Etype (N, Standard_Boolean);
1879 end Legal_Formal_Attribute;
1881 ------------------------
1882 -- Standard_Attribute --
1883 ------------------------
1885 procedure Standard_Attribute (Val : Int) is
1887 Check_Standard_Prefix;
1888 Rewrite (N, Make_Integer_Literal (Loc, Val));
1890 end Standard_Attribute;
1892 -------------------------
1893 -- Unexpected Argument --
1894 -------------------------
1896 procedure Unexpected_Argument (En : Node_Id) is
1898 Error_Attr ("unexpected argument for % attribute", En);
1899 end Unexpected_Argument;
1901 -------------------------------------------------
1902 -- Validate_Non_Static_Attribute_Function_Call --
1903 -------------------------------------------------
1905 -- This function should be moved to Sem_Dist ???
1907 procedure Validate_Non_Static_Attribute_Function_Call is
1909 if In_Preelaborated_Unit
1910 and then not In_Subprogram_Or_Concurrent_Unit
1912 Flag_Non_Static_Expr
1913 ("non-static function call in preelaborated unit!", N);
1915 end Validate_Non_Static_Attribute_Function_Call;
1917 -- Start of processing for Analyze_Attribute
1920 -- Immediate return if unrecognized attribute (already diagnosed
1921 -- by parser, so there is nothing more that we need to do)
1923 if not Is_Attribute_Name (Aname) then
1924 raise Bad_Attribute;
1927 -- Deal with Ada 83 issues
1929 if Comes_From_Source (N) then
1930 if not Attribute_83 (Attr_Id) then
1931 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
1932 Error_Msg_Name_1 := Aname;
1933 Error_Msg_N ("(Ada 83) attribute% is not standard?", N);
1936 if Attribute_Impl_Def (Attr_Id) then
1937 Check_Restriction (No_Implementation_Attributes, N);
1942 -- Deal with Ada 2005 attributes that are
1944 if Attribute_05 (Attr_Id) and then Ada_Version < Ada_2005 then
1945 Check_Restriction (No_Implementation_Attributes, N);
1948 -- Remote access to subprogram type access attribute reference needs
1949 -- unanalyzed copy for tree transformation. The analyzed copy is used
1950 -- for its semantic information (whether prefix is a remote subprogram
1951 -- name), the unanalyzed copy is used to construct new subtree rooted
1952 -- with N_Aggregate which represents a fat pointer aggregate.
1954 if Aname = Name_Access then
1955 Discard_Node (Copy_Separate_Tree (N));
1958 -- Analyze prefix and exit if error in analysis. If the prefix is an
1959 -- incomplete type, use full view if available. Note that there are
1960 -- some attributes for which we do not analyze the prefix, since the
1961 -- prefix is not a normal name, or else needs special handling.
1963 if Aname /= Name_Elab_Body
1965 Aname /= Name_Elab_Spec
1967 Aname /= Name_Elab_Subp_Body
1969 Aname /= Name_UET_Address
1971 Aname /= Name_Enabled
1976 P_Type := Etype (P);
1978 if Is_Entity_Name (P)
1979 and then Present (Entity (P))
1980 and then Is_Type (Entity (P))
1982 if Ekind (Entity (P)) = E_Incomplete_Type then
1983 P_Type := Get_Full_View (P_Type);
1984 Set_Entity (P, P_Type);
1985 Set_Etype (P, P_Type);
1987 elsif Entity (P) = Current_Scope
1988 and then Is_Record_Type (Entity (P))
1990 -- Use of current instance within the type. Verify that if the
1991 -- attribute appears within a constraint, it yields an access
1992 -- type, other uses are illegal.
2000 and then Nkind (Parent (Par)) /= N_Component_Definition
2002 Par := Parent (Par);
2006 and then Nkind (Par) = N_Subtype_Indication
2008 if Attr_Id /= Attribute_Access
2009 and then Attr_Id /= Attribute_Unchecked_Access
2010 and then Attr_Id /= Attribute_Unrestricted_Access
2013 ("in a constraint the current instance can only"
2014 & " be used with an access attribute", N);
2021 if P_Type = Any_Type then
2022 raise Bad_Attribute;
2025 P_Base_Type := Base_Type (P_Type);
2028 -- Analyze expressions that may be present, exiting if an error occurs
2035 E1 := First (Exprs);
2038 -- Check for missing/bad expression (result of previous error)
2040 if No (E1) or else Etype (E1) = Any_Type then
2041 raise Bad_Attribute;
2046 if Present (E2) then
2049 if Etype (E2) = Any_Type then
2050 raise Bad_Attribute;
2053 if Present (Next (E2)) then
2054 Unexpected_Argument (Next (E2));
2059 -- Ada 2005 (AI-345): Ensure that the compiler gives exactly the current
2060 -- output compiling in Ada 95 mode for the case of ambiguous prefixes.
2062 if Ada_Version < Ada_2005
2063 and then Is_Overloaded (P)
2064 and then Aname /= Name_Access
2065 and then Aname /= Name_Address
2066 and then Aname /= Name_Code_Address
2067 and then Aname /= Name_Count
2068 and then Aname /= Name_Result
2069 and then Aname /= Name_Unchecked_Access
2071 Error_Attr ("ambiguous prefix for % attribute", P);
2073 elsif Ada_Version >= Ada_2005
2074 and then Is_Overloaded (P)
2075 and then Aname /= Name_Access
2076 and then Aname /= Name_Address
2077 and then Aname /= Name_Code_Address
2078 and then Aname /= Name_Result
2079 and then Aname /= Name_Unchecked_Access
2081 -- Ada 2005 (AI-345): Since protected and task types have primitive
2082 -- entry wrappers, the attributes Count, Caller and AST_Entry require
2085 if Ada_Version >= Ada_2005
2086 and then (Aname = Name_Count
2087 or else Aname = Name_Caller
2088 or else Aname = Name_AST_Entry)
2091 Count : Natural := 0;
2096 Get_First_Interp (P, I, It);
2097 while Present (It.Nam) loop
2098 if Comes_From_Source (It.Nam) then
2104 Get_Next_Interp (I, It);
2108 Error_Attr ("ambiguous prefix for % attribute", P);
2110 Set_Is_Overloaded (P, False);
2115 Error_Attr ("ambiguous prefix for % attribute", P);
2119 -- In SPARK, attributes of private types are only allowed if the full
2120 -- type declaration is visible.
2122 if Is_Entity_Name (P)
2123 and then Present (Entity (P)) -- needed in some cases
2124 and then Is_Type (Entity (P))
2125 and then Is_Private_Type (P_Type)
2126 and then not In_Open_Scopes (Scope (P_Type))
2127 and then not In_Spec_Expression
2129 Check_SPARK_Restriction ("invisible attribute of type", N);
2132 -- Remaining processing depends on attribute
2136 -- Attributes related to Ada 2012 iterators. Attribute specifications
2137 -- exist for these, but they cannot be queried.
2139 when Attribute_Constant_Indexing |
2140 Attribute_Default_Iterator |
2141 Attribute_Implicit_Dereference |
2142 Attribute_Iterator_Element |
2143 Attribute_Variable_Indexing =>
2144 Error_Msg_N ("illegal attribute", N);
2150 when Attribute_Abort_Signal =>
2151 Check_Standard_Prefix;
2152 Rewrite (N, New_Reference_To (Stand.Abort_Signal, Loc));
2159 when Attribute_Access =>
2160 Analyze_Access_Attribute;
2166 when Attribute_Address =>
2169 -- Check for some junk cases, where we have to allow the address
2170 -- attribute but it does not make much sense, so at least for now
2171 -- just replace with Null_Address.
2173 -- We also do this if the prefix is a reference to the AST_Entry
2174 -- attribute. If expansion is active, the attribute will be
2175 -- replaced by a function call, and address will work fine and
2176 -- get the proper value, but if expansion is not active, then
2177 -- the check here allows proper semantic analysis of the reference.
2179 -- An Address attribute created by expansion is legal even when it
2180 -- applies to other entity-denoting expressions.
2182 if Is_Protected_Self_Reference (P) then
2184 -- Address attribute on a protected object self reference is legal
2188 elsif Is_Entity_Name (P) then
2190 Ent : constant Entity_Id := Entity (P);
2193 if Is_Subprogram (Ent) then
2194 Set_Address_Taken (Ent);
2195 Kill_Current_Values (Ent);
2197 -- An Address attribute is accepted when generated by the
2198 -- compiler for dispatching operation, and an error is
2199 -- issued once the subprogram is frozen (to avoid confusing
2200 -- errors about implicit uses of Address in the dispatch
2201 -- table initialization).
2203 if Has_Pragma_Inline_Always (Entity (P))
2204 and then Comes_From_Source (P)
2207 ("prefix of % attribute cannot be Inline_Always" &
2210 -- It is illegal to apply 'Address to an intrinsic
2211 -- subprogram. This is now formalized in AI05-0095.
2212 -- In an instance, an attempt to obtain 'Address of an
2213 -- intrinsic subprogram (e.g the renaming of a predefined
2214 -- operator that is an actual) raises Program_Error.
2216 elsif Convention (Ent) = Convention_Intrinsic then
2219 Make_Raise_Program_Error (Loc,
2220 Reason => PE_Address_Of_Intrinsic));
2224 ("cannot take Address of intrinsic subprogram", N);
2227 -- Issue an error if prefix denotes an eliminated subprogram
2230 Check_For_Eliminated_Subprogram (P, Ent);
2233 elsif Is_Object (Ent)
2234 or else Ekind (Ent) = E_Label
2236 Set_Address_Taken (Ent);
2238 -- Deal with No_Implicit_Aliasing restriction
2240 if Restriction_Check_Required (No_Implicit_Aliasing) then
2241 if not Is_Aliased_View (P) then
2242 Check_Restriction (No_Implicit_Aliasing, P);
2244 Check_No_Implicit_Aliasing (P);
2248 -- If we have an address of an object, and the attribute
2249 -- comes from source, then set the object as potentially
2250 -- source modified. We do this because the resulting address
2251 -- can potentially be used to modify the variable and we
2252 -- might not detect this, leading to some junk warnings.
2254 Set_Never_Set_In_Source (Ent, False);
2256 elsif (Is_Concurrent_Type (Etype (Ent))
2257 and then Etype (Ent) = Base_Type (Ent))
2258 or else Ekind (Ent) = E_Package
2259 or else Is_Generic_Unit (Ent)
2262 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
2265 Error_Attr ("invalid prefix for % attribute", P);
2269 elsif Nkind (P) = N_Attribute_Reference
2270 and then Attribute_Name (P) = Name_AST_Entry
2273 New_Occurrence_Of (RTE (RE_Null_Address), Sloc (N)));
2275 elsif Is_Object_Reference (P) then
2278 elsif Nkind (P) = N_Selected_Component
2279 and then Is_Subprogram (Entity (Selector_Name (P)))
2283 -- What exactly are we allowing here ??? and is this properly
2284 -- documented in the sinfo documentation for this node ???
2286 elsif not Comes_From_Source (N) then
2290 Error_Attr ("invalid prefix for % attribute", P);
2293 Set_Etype (N, RTE (RE_Address));
2299 when Attribute_Address_Size =>
2300 Standard_Attribute (System_Address_Size);
2306 when Attribute_Adjacent =>
2307 Check_Floating_Point_Type_2;
2308 Set_Etype (N, P_Base_Type);
2309 Resolve (E1, P_Base_Type);
2310 Resolve (E2, P_Base_Type);
2316 when Attribute_Aft =>
2317 Check_Fixed_Point_Type_0;
2318 Set_Etype (N, Universal_Integer);
2324 when Attribute_Alignment =>
2326 -- Don't we need more checking here, cf Size ???
2329 Check_Not_Incomplete_Type;
2331 Set_Etype (N, Universal_Integer);
2337 when Attribute_Asm_Input =>
2338 Check_Asm_Attribute;
2340 -- The back-end may need to take the address of E2
2342 if Is_Entity_Name (E2) then
2343 Set_Address_Taken (Entity (E2));
2346 Set_Etype (N, RTE (RE_Asm_Input_Operand));
2352 when Attribute_Asm_Output =>
2353 Check_Asm_Attribute;
2355 if Etype (E2) = Any_Type then
2358 elsif Aname = Name_Asm_Output then
2359 if not Is_Variable (E2) then
2361 ("second argument for Asm_Output is not variable", E2);
2365 Note_Possible_Modification (E2, Sure => True);
2367 -- The back-end may need to take the address of E2
2369 if Is_Entity_Name (E2) then
2370 Set_Address_Taken (Entity (E2));
2373 Set_Etype (N, RTE (RE_Asm_Output_Operand));
2379 when Attribute_AST_Entry => AST_Entry : declare
2385 -- Indicates if entry family index is present. Note the coding
2386 -- here handles the entry family case, but in fact it cannot be
2387 -- executed currently, because pragma AST_Entry does not permit
2388 -- the specification of an entry family.
2390 procedure Bad_AST_Entry;
2391 -- Signal a bad AST_Entry pragma
2393 function OK_Entry (E : Entity_Id) return Boolean;
2394 -- Checks that E is of an appropriate entity kind for an entry
2395 -- (i.e. E_Entry if Index is False, or E_Entry_Family if Index
2396 -- is set True for the entry family case). In the True case,
2397 -- makes sure that Is_AST_Entry is set on the entry.
2403 procedure Bad_AST_Entry is
2405 Error_Attr_P ("prefix for % attribute must be task entry");
2412 function OK_Entry (E : Entity_Id) return Boolean is
2417 Result := (Ekind (E) = E_Entry_Family);
2419 Result := (Ekind (E) = E_Entry);
2423 if not Is_AST_Entry (E) then
2424 Error_Msg_Name_2 := Aname;
2425 Error_Attr ("% attribute requires previous % pragma", P);
2432 -- Start of processing for AST_Entry
2438 -- Deal with entry family case
2440 if Nkind (P) = N_Indexed_Component then
2448 Ptyp := Etype (Pref);
2450 if Ptyp = Any_Type or else Error_Posted (Pref) then
2454 -- If the prefix is a selected component whose prefix is of an
2455 -- access type, then introduce an explicit dereference.
2456 -- ??? Could we reuse Check_Dereference here?
2458 if Nkind (Pref) = N_Selected_Component
2459 and then Is_Access_Type (Ptyp)
2462 Make_Explicit_Dereference (Sloc (Pref),
2463 Relocate_Node (Pref)));
2464 Analyze_And_Resolve (Pref, Designated_Type (Ptyp));
2467 -- Prefix can be of the form a.b, where a is a task object
2468 -- and b is one of the entries of the corresponding task type.
2470 if Nkind (Pref) = N_Selected_Component
2471 and then OK_Entry (Entity (Selector_Name (Pref)))
2472 and then Is_Object_Reference (Prefix (Pref))
2473 and then Is_Task_Type (Etype (Prefix (Pref)))
2477 -- Otherwise the prefix must be an entry of a containing task,
2478 -- or of a variable of the enclosing task type.
2481 if Nkind_In (Pref, N_Identifier, N_Expanded_Name) then
2482 Ent := Entity (Pref);
2484 if not OK_Entry (Ent)
2485 or else not In_Open_Scopes (Scope (Ent))
2495 Set_Etype (N, RTE (RE_AST_Handler));
2502 -- Note: when the base attribute appears in the context of a subtype
2503 -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by
2504 -- the following circuit.
2506 when Attribute_Base => Base : declare
2514 if Ada_Version >= Ada_95
2515 and then not Is_Scalar_Type (Typ)
2516 and then not Is_Generic_Type (Typ)
2518 Error_Attr_P ("prefix of Base attribute must be scalar type");
2520 elsif Sloc (Typ) = Standard_Location
2521 and then Base_Type (Typ) = Typ
2522 and then Warn_On_Redundant_Constructs
2524 Error_Msg_NE -- CODEFIX
2525 ("?redundant attribute, & is its own base type", N, Typ);
2528 if Nkind (Parent (N)) /= N_Attribute_Reference then
2529 Error_Msg_Name_1 := Aname;
2530 Check_SPARK_Restriction
2531 ("attribute% is only allowed as prefix of another attribute", P);
2534 Set_Etype (N, Base_Type (Entity (P)));
2535 Set_Entity (N, Base_Type (Entity (P)));
2536 Rewrite (N, New_Reference_To (Entity (N), Loc));
2544 when Attribute_Bit => Bit :
2548 if not Is_Object_Reference (P) then
2549 Error_Attr_P ("prefix for % attribute must be object");
2551 -- What about the access object cases ???
2557 Set_Etype (N, Universal_Integer);
2564 when Attribute_Bit_Order => Bit_Order :
2569 if not Is_Record_Type (P_Type) then
2570 Error_Attr_P ("prefix of % attribute must be record type");
2573 if Bytes_Big_Endian xor Reverse_Bit_Order (P_Type) then
2575 New_Occurrence_Of (RTE (RE_High_Order_First), Loc));
2578 New_Occurrence_Of (RTE (RE_Low_Order_First), Loc));
2581 Set_Etype (N, RTE (RE_Bit_Order));
2584 -- Reset incorrect indication of staticness
2586 Set_Is_Static_Expression (N, False);
2593 -- Note: in generated code, we can have a Bit_Position attribute
2594 -- applied to a (naked) record component (i.e. the prefix is an
2595 -- identifier that references an E_Component or E_Discriminant
2596 -- entity directly, and this is interpreted as expected by Gigi.
2597 -- The following code will not tolerate such usage, but when the
2598 -- expander creates this special case, it marks it as analyzed
2599 -- immediately and sets an appropriate type.
2601 when Attribute_Bit_Position =>
2602 if Comes_From_Source (N) then
2606 Set_Etype (N, Universal_Integer);
2612 when Attribute_Body_Version =>
2615 Set_Etype (N, RTE (RE_Version_String));
2621 when Attribute_Callable =>
2623 Set_Etype (N, Standard_Boolean);
2630 when Attribute_Caller => Caller : declare
2637 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
2640 if not Is_Entry (Ent) then
2641 Error_Attr ("invalid entry name", N);
2645 Error_Attr ("invalid entry name", N);
2649 for J in reverse 0 .. Scope_Stack.Last loop
2650 S := Scope_Stack.Table (J).Entity;
2652 if S = Scope (Ent) then
2653 Error_Attr ("Caller must appear in matching accept or body", N);
2659 Set_Etype (N, RTE (RO_AT_Task_Id));
2666 when Attribute_Ceiling =>
2667 Check_Floating_Point_Type_1;
2668 Set_Etype (N, P_Base_Type);
2669 Resolve (E1, P_Base_Type);
2675 when Attribute_Class =>
2676 Check_Restriction (No_Dispatch, N);
2680 -- Applying Class to untagged incomplete type is obsolescent in Ada
2681 -- 2005. Note that we can't test Is_Tagged_Type here on P_Type, since
2682 -- this flag gets set by Find_Type in this situation.
2684 if Restriction_Check_Required (No_Obsolescent_Features)
2685 and then Ada_Version >= Ada_2005
2686 and then Ekind (P_Type) = E_Incomplete_Type
2689 DN : constant Node_Id := Declaration_Node (P_Type);
2691 if Nkind (DN) = N_Incomplete_Type_Declaration
2692 and then not Tagged_Present (DN)
2694 Check_Restriction (No_Obsolescent_Features, P);
2703 when Attribute_Code_Address =>
2706 if Nkind (P) = N_Attribute_Reference
2707 and then (Attribute_Name (P) = Name_Elab_Body
2709 Attribute_Name (P) = Name_Elab_Spec)
2713 elsif not Is_Entity_Name (P)
2714 or else (Ekind (Entity (P)) /= E_Function
2716 Ekind (Entity (P)) /= E_Procedure)
2718 Error_Attr ("invalid prefix for % attribute", P);
2719 Set_Address_Taken (Entity (P));
2721 -- Issue an error if the prefix denotes an eliminated subprogram
2724 Check_For_Eliminated_Subprogram (P, Entity (P));
2727 Set_Etype (N, RTE (RE_Address));
2729 ----------------------
2730 -- Compiler_Version --
2731 ----------------------
2733 when Attribute_Compiler_Version =>
2735 Check_Standard_Prefix;
2736 Rewrite (N, Make_String_Literal (Loc, "GNAT " & Gnat_Version_String));
2737 Analyze_And_Resolve (N, Standard_String);
2739 --------------------
2740 -- Component_Size --
2741 --------------------
2743 when Attribute_Component_Size =>
2745 Set_Etype (N, Universal_Integer);
2747 -- Note: unlike other array attributes, unconstrained arrays are OK
2749 if Is_Array_Type (P_Type) and then not Is_Constrained (P_Type) then
2759 when Attribute_Compose =>
2760 Check_Floating_Point_Type_2;
2761 Set_Etype (N, P_Base_Type);
2762 Resolve (E1, P_Base_Type);
2763 Resolve (E2, Any_Integer);
2769 when Attribute_Constrained =>
2771 Set_Etype (N, Standard_Boolean);
2773 -- Case from RM J.4(2) of constrained applied to private type
2775 if Is_Entity_Name (P) and then Is_Type (Entity (P)) then
2776 Check_Restriction (No_Obsolescent_Features, P);
2778 if Warn_On_Obsolescent_Feature then
2780 ("constrained for private type is an " &
2781 "obsolescent feature (RM J.4)?", N);
2784 -- If we are within an instance, the attribute must be legal
2785 -- because it was valid in the generic unit. Ditto if this is
2786 -- an inlining of a function declared in an instance.
2789 or else In_Inlined_Body
2793 -- For sure OK if we have a real private type itself, but must
2794 -- be completed, cannot apply Constrained to incomplete type.
2796 elsif Is_Private_Type (Entity (P)) then
2798 -- Note: this is one of the Annex J features that does not
2799 -- generate a warning from -gnatwj, since in fact it seems
2800 -- very useful, and is used in the GNAT runtime.
2802 Check_Not_Incomplete_Type;
2806 -- Normal (non-obsolescent case) of application to object of
2807 -- a discriminated type.
2810 Check_Object_Reference (P);
2812 -- If N does not come from source, then we allow the
2813 -- the attribute prefix to be of a private type whose
2814 -- full type has discriminants. This occurs in cases
2815 -- involving expanded calls to stream attributes.
2817 if not Comes_From_Source (N) then
2818 P_Type := Underlying_Type (P_Type);
2821 -- Must have discriminants or be an access type designating
2822 -- a type with discriminants. If it is a classwide type is ???
2823 -- has unknown discriminants.
2825 if Has_Discriminants (P_Type)
2826 or else Has_Unknown_Discriminants (P_Type)
2828 (Is_Access_Type (P_Type)
2829 and then Has_Discriminants (Designated_Type (P_Type)))
2833 -- Also allow an object of a generic type if extensions allowed
2834 -- and allow this for any type at all.
2836 elsif (Is_Generic_Type (P_Type)
2837 or else Is_Generic_Actual_Type (P_Type))
2838 and then Extensions_Allowed
2844 -- Fall through if bad prefix
2847 ("prefix of % attribute must be object of discriminated type");
2853 when Attribute_Copy_Sign =>
2854 Check_Floating_Point_Type_2;
2855 Set_Etype (N, P_Base_Type);
2856 Resolve (E1, P_Base_Type);
2857 Resolve (E2, P_Base_Type);
2863 when Attribute_Count => Count :
2872 if Nkind_In (P, N_Identifier, N_Expanded_Name) then
2875 if Ekind (Ent) /= E_Entry then
2876 Error_Attr ("invalid entry name", N);
2879 elsif Nkind (P) = N_Indexed_Component then
2880 if not Is_Entity_Name (Prefix (P))
2881 or else No (Entity (Prefix (P)))
2882 or else Ekind (Entity (Prefix (P))) /= E_Entry_Family
2884 if Nkind (Prefix (P)) = N_Selected_Component
2885 and then Present (Entity (Selector_Name (Prefix (P))))
2886 and then Ekind (Entity (Selector_Name (Prefix (P)))) =
2890 ("attribute % must apply to entry of current task", P);
2893 Error_Attr ("invalid entry family name", P);
2898 Ent := Entity (Prefix (P));
2901 elsif Nkind (P) = N_Selected_Component
2902 and then Present (Entity (Selector_Name (P)))
2903 and then Ekind (Entity (Selector_Name (P))) = E_Entry
2906 ("attribute % must apply to entry of current task", P);
2909 Error_Attr ("invalid entry name", N);
2913 for J in reverse 0 .. Scope_Stack.Last loop
2914 S := Scope_Stack.Table (J).Entity;
2916 if S = Scope (Ent) then
2917 if Nkind (P) = N_Expanded_Name then
2918 Tsk := Entity (Prefix (P));
2920 -- The prefix denotes either the task type, or else a
2921 -- single task whose task type is being analyzed.
2926 or else (not Is_Type (Tsk)
2927 and then Etype (Tsk) = S
2928 and then not (Comes_From_Source (S)))
2933 ("Attribute % must apply to entry of current task", N);
2939 elsif Ekind (Scope (Ent)) in Task_Kind
2941 not Ekind_In (S, E_Loop, E_Block, E_Entry, E_Entry_Family)
2943 Error_Attr ("Attribute % cannot appear in inner unit", N);
2945 elsif Ekind (Scope (Ent)) = E_Protected_Type
2946 and then not Has_Completion (Scope (Ent))
2948 Error_Attr ("attribute % can only be used inside body", N);
2952 if Is_Overloaded (P) then
2954 Index : Interp_Index;
2958 Get_First_Interp (P, Index, It);
2960 while Present (It.Nam) loop
2961 if It.Nam = Ent then
2964 -- Ada 2005 (AI-345): Do not consider primitive entry
2965 -- wrappers generated for task or protected types.
2967 elsif Ada_Version >= Ada_2005
2968 and then not Comes_From_Source (It.Nam)
2973 Error_Attr ("ambiguous entry name", N);
2976 Get_Next_Interp (Index, It);
2981 Set_Etype (N, Universal_Integer);
2984 -----------------------
2985 -- Default_Bit_Order --
2986 -----------------------
2988 when Attribute_Default_Bit_Order => Default_Bit_Order :
2990 Check_Standard_Prefix;
2992 if Bytes_Big_Endian then
2994 Make_Integer_Literal (Loc, False_Value));
2997 Make_Integer_Literal (Loc, True_Value));
3000 Set_Etype (N, Universal_Integer);
3001 Set_Is_Static_Expression (N);
3002 end Default_Bit_Order;
3008 when Attribute_Definite =>
3009 Legal_Formal_Attribute;
3015 when Attribute_Delta =>
3016 Check_Fixed_Point_Type_0;
3017 Set_Etype (N, Universal_Real);
3023 when Attribute_Denorm =>
3024 Check_Floating_Point_Type_0;
3025 Set_Etype (N, Standard_Boolean);
3027 ---------------------
3028 -- Descriptor_Size --
3029 ---------------------
3031 when Attribute_Descriptor_Size =>
3034 if not Is_Entity_Name (P)
3035 or else not Is_Type (Entity (P))
3037 Error_Attr_P ("prefix of attribute % must denote a type");
3040 Set_Etype (N, Universal_Integer);
3046 when Attribute_Digits =>
3050 if not Is_Floating_Point_Type (P_Type)
3051 and then not Is_Decimal_Fixed_Point_Type (P_Type)
3054 ("prefix of % attribute must be float or decimal type");
3057 Set_Etype (N, Universal_Integer);
3063 -- Also handles processing for Elab_Spec and Elab_Subp_Body
3065 when Attribute_Elab_Body |
3066 Attribute_Elab_Spec |
3067 Attribute_Elab_Subp_Body =>
3070 Check_Unit_Name (P);
3071 Set_Etype (N, Standard_Void_Type);
3073 -- We have to manually call the expander in this case to get
3074 -- the necessary expansion (normally attributes that return
3075 -- entities are not expanded).
3083 -- Shares processing with Elab_Body
3089 when Attribute_Elaborated =>
3091 Check_Unit_Name (P);
3092 Set_Etype (N, Standard_Boolean);
3098 when Attribute_Emax =>
3099 Check_Floating_Point_Type_0;
3100 Set_Etype (N, Universal_Integer);
3106 when Attribute_Enabled =>
3107 Check_Either_E0_Or_E1;
3109 if Present (E1) then
3110 if not Is_Entity_Name (E1) or else No (Entity (E1)) then
3111 Error_Msg_N ("entity name expected for Enabled attribute", E1);
3116 if Nkind (P) /= N_Identifier then
3117 Error_Msg_N ("identifier expected (check name)", P);
3118 elsif Get_Check_Id (Chars (P)) = No_Check_Id then
3119 Error_Msg_N ("& is not a recognized check name", P);
3122 Set_Etype (N, Standard_Boolean);
3128 when Attribute_Enum_Rep => Enum_Rep : declare
3130 if Present (E1) then
3132 Check_Discrete_Type;
3133 Resolve (E1, P_Base_Type);
3136 if not Is_Entity_Name (P)
3137 or else (not Is_Object (Entity (P))
3139 Ekind (Entity (P)) /= E_Enumeration_Literal)
3142 ("prefix of % attribute must be " &
3143 "discrete type/object or enum literal");
3147 Set_Etype (N, Universal_Integer);
3154 when Attribute_Enum_Val => Enum_Val : begin
3158 if not Is_Enumeration_Type (P_Type) then
3159 Error_Attr_P ("prefix of % attribute must be enumeration type");
3162 -- If the enumeration type has a standard representation, the effect
3163 -- is the same as 'Val, so rewrite the attribute as a 'Val.
3165 if not Has_Non_Standard_Rep (P_Base_Type) then
3167 Make_Attribute_Reference (Loc,
3168 Prefix => Relocate_Node (Prefix (N)),
3169 Attribute_Name => Name_Val,
3170 Expressions => New_List (Relocate_Node (E1))));
3171 Analyze_And_Resolve (N, P_Base_Type);
3173 -- Non-standard representation case (enumeration with holes)
3177 Resolve (E1, Any_Integer);
3178 Set_Etype (N, P_Base_Type);
3186 when Attribute_Epsilon =>
3187 Check_Floating_Point_Type_0;
3188 Set_Etype (N, Universal_Real);
3194 when Attribute_Exponent =>
3195 Check_Floating_Point_Type_1;
3196 Set_Etype (N, Universal_Integer);
3197 Resolve (E1, P_Base_Type);
3203 when Attribute_External_Tag =>
3207 Set_Etype (N, Standard_String);
3209 if not Is_Tagged_Type (P_Type) then
3210 Error_Attr_P ("prefix of % attribute must be tagged");
3217 when Attribute_Fast_Math =>
3218 Check_Standard_Prefix;
3220 if Opt.Fast_Math then
3221 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
3223 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
3230 when Attribute_First =>
3231 Check_Array_Or_Scalar_Type;
3232 Bad_Attribute_For_Predicate;
3238 when Attribute_First_Bit =>
3240 Set_Etype (N, Universal_Integer);
3246 when Attribute_Fixed_Value =>
3248 Check_Fixed_Point_Type;
3249 Resolve (E1, Any_Integer);
3250 Set_Etype (N, P_Base_Type);
3256 when Attribute_Floor =>
3257 Check_Floating_Point_Type_1;
3258 Set_Etype (N, P_Base_Type);
3259 Resolve (E1, P_Base_Type);
3265 when Attribute_Fore =>
3266 Check_Fixed_Point_Type_0;
3267 Set_Etype (N, Universal_Integer);
3273 when Attribute_Fraction =>
3274 Check_Floating_Point_Type_1;
3275 Set_Etype (N, P_Base_Type);
3276 Resolve (E1, P_Base_Type);
3282 when Attribute_From_Any =>
3284 Check_PolyORB_Attribute;
3285 Set_Etype (N, P_Base_Type);
3287 -----------------------
3288 -- Has_Access_Values --
3289 -----------------------
3291 when Attribute_Has_Access_Values =>
3294 Set_Etype (N, Standard_Boolean);
3296 -----------------------
3297 -- Has_Tagged_Values --
3298 -----------------------
3300 when Attribute_Has_Tagged_Values =>
3303 Set_Etype (N, Standard_Boolean);
3305 -----------------------
3306 -- Has_Discriminants --
3307 -----------------------
3309 when Attribute_Has_Discriminants =>
3310 Legal_Formal_Attribute;
3316 when Attribute_Identity =>
3320 if Etype (P) = Standard_Exception_Type then
3321 Set_Etype (N, RTE (RE_Exception_Id));
3323 -- Ada 2005 (AI-345): Attribute 'Identity may be applied to
3324 -- task interface class-wide types.
3326 elsif Is_Task_Type (Etype (P))
3327 or else (Is_Access_Type (Etype (P))
3328 and then Is_Task_Type (Designated_Type (Etype (P))))
3329 or else (Ada_Version >= Ada_2005
3330 and then Ekind (Etype (P)) = E_Class_Wide_Type
3331 and then Is_Interface (Etype (P))
3332 and then Is_Task_Interface (Etype (P)))
3335 Set_Etype (N, RTE (RO_AT_Task_Id));
3338 if Ada_Version >= Ada_2005 then
3340 ("prefix of % attribute must be an exception, a " &
3341 "task or a task interface class-wide object");
3344 ("prefix of % attribute must be a task or an exception");
3352 when Attribute_Image => Image :
3354 Check_SPARK_Restriction_On_Attribute;
3356 Set_Etype (N, Standard_String);
3358 if Is_Real_Type (P_Type) then
3359 if Ada_Version = Ada_83 and then Comes_From_Source (N) then
3360 Error_Msg_Name_1 := Aname;
3362 ("(Ada 83) % attribute not allowed for real types", N);
3366 if Is_Enumeration_Type (P_Type) then
3367 Check_Restriction (No_Enumeration_Maps, N);
3371 Resolve (E1, P_Base_Type);
3373 Validate_Non_Static_Attribute_Function_Call;
3380 when Attribute_Img => Img :
3383 Set_Etype (N, Standard_String);
3385 if not Is_Scalar_Type (P_Type)
3386 or else (Is_Entity_Name (P) and then Is_Type (Entity (P)))
3389 ("prefix of % attribute must be scalar object name");
3399 when Attribute_Input =>
3401 Check_Stream_Attribute (TSS_Stream_Input);
3402 Set_Etype (N, P_Base_Type);
3408 when Attribute_Integer_Value =>
3411 Resolve (E1, Any_Fixed);
3413 -- Signal an error if argument type is not a specific fixed-point
3414 -- subtype. An error has been signalled already if the argument
3415 -- was not of a fixed-point type.
3417 if Etype (E1) = Any_Fixed and then not Error_Posted (E1) then
3418 Error_Attr ("argument of % must be of a fixed-point type", E1);
3421 Set_Etype (N, P_Base_Type);
3427 when Attribute_Invalid_Value =>
3430 Set_Etype (N, P_Base_Type);
3431 Invalid_Value_Used := True;
3437 when Attribute_Large =>
3440 Set_Etype (N, Universal_Real);
3446 when Attribute_Last =>
3447 Check_Array_Or_Scalar_Type;
3448 Bad_Attribute_For_Predicate;
3454 when Attribute_Last_Bit =>
3456 Set_Etype (N, Universal_Integer);
3462 when Attribute_Leading_Part =>
3463 Check_Floating_Point_Type_2;
3464 Set_Etype (N, P_Base_Type);
3465 Resolve (E1, P_Base_Type);
3466 Resolve (E2, Any_Integer);
3472 when Attribute_Length =>
3474 Set_Etype (N, Universal_Integer);
3480 when Attribute_Machine =>
3481 Check_Floating_Point_Type_1;
3482 Set_Etype (N, P_Base_Type);
3483 Resolve (E1, P_Base_Type);
3489 when Attribute_Machine_Emax =>
3490 Check_Floating_Point_Type_0;
3491 Set_Etype (N, Universal_Integer);
3497 when Attribute_Machine_Emin =>
3498 Check_Floating_Point_Type_0;
3499 Set_Etype (N, Universal_Integer);
3501 ----------------------
3502 -- Machine_Mantissa --
3503 ----------------------
3505 when Attribute_Machine_Mantissa =>
3506 Check_Floating_Point_Type_0;
3507 Set_Etype (N, Universal_Integer);
3509 -----------------------
3510 -- Machine_Overflows --
3511 -----------------------
3513 when Attribute_Machine_Overflows =>
3516 Set_Etype (N, Standard_Boolean);
3522 when Attribute_Machine_Radix =>
3525 Set_Etype (N, Universal_Integer);
3527 ----------------------
3528 -- Machine_Rounding --
3529 ----------------------
3531 when Attribute_Machine_Rounding =>
3532 Check_Floating_Point_Type_1;
3533 Set_Etype (N, P_Base_Type);
3534 Resolve (E1, P_Base_Type);
3536 --------------------
3537 -- Machine_Rounds --
3538 --------------------
3540 when Attribute_Machine_Rounds =>
3543 Set_Etype (N, Standard_Boolean);
3549 when Attribute_Machine_Size =>
3552 Check_Not_Incomplete_Type;
3553 Set_Etype (N, Universal_Integer);
3559 when Attribute_Mantissa =>
3562 Set_Etype (N, Universal_Integer);
3568 when Attribute_Max =>
3571 Resolve (E1, P_Base_Type);
3572 Resolve (E2, P_Base_Type);
3573 Set_Etype (N, P_Base_Type);
3575 ----------------------------------
3576 -- Max_Alignment_For_Allocation --
3577 -- Max_Size_In_Storage_Elements --
3578 ----------------------------------
3580 when Attribute_Max_Alignment_For_Allocation |
3581 Attribute_Max_Size_In_Storage_Elements =>
3584 Check_Not_Incomplete_Type;
3585 Set_Etype (N, Universal_Integer);
3587 -----------------------
3588 -- Maximum_Alignment --
3589 -----------------------
3591 when Attribute_Maximum_Alignment =>
3592 Standard_Attribute (Ttypes.Maximum_Alignment);
3594 --------------------
3595 -- Mechanism_Code --
3596 --------------------
3598 when Attribute_Mechanism_Code =>
3599 if not Is_Entity_Name (P)
3600 or else not Is_Subprogram (Entity (P))
3602 Error_Attr_P ("prefix of % attribute must be subprogram");
3605 Check_Either_E0_Or_E1;
3607 if Present (E1) then
3608 Resolve (E1, Any_Integer);
3609 Set_Etype (E1, Standard_Integer);
3611 if not Is_Static_Expression (E1) then
3612 Flag_Non_Static_Expr
3613 ("expression for parameter number must be static!", E1);
3616 elsif UI_To_Int (Intval (E1)) > Number_Formals (Entity (P))
3617 or else UI_To_Int (Intval (E1)) < 0
3619 Error_Attr ("invalid parameter number for % attribute", E1);
3623 Set_Etype (N, Universal_Integer);
3629 when Attribute_Min =>
3632 Resolve (E1, P_Base_Type);
3633 Resolve (E2, P_Base_Type);
3634 Set_Etype (N, P_Base_Type);
3640 when Attribute_Mod =>
3642 -- Note: this attribute is only allowed in Ada 2005 mode, but
3643 -- we do not need to test that here, since Mod is only recognized
3644 -- as an attribute name in Ada 2005 mode during the parse.
3647 Check_Modular_Integer_Type;
3648 Resolve (E1, Any_Integer);
3649 Set_Etype (N, P_Base_Type);
3655 when Attribute_Model =>
3656 Check_Floating_Point_Type_1;
3657 Set_Etype (N, P_Base_Type);
3658 Resolve (E1, P_Base_Type);
3664 when Attribute_Model_Emin =>
3665 Check_Floating_Point_Type_0;
3666 Set_Etype (N, Universal_Integer);
3672 when Attribute_Model_Epsilon =>
3673 Check_Floating_Point_Type_0;
3674 Set_Etype (N, Universal_Real);
3676 --------------------
3677 -- Model_Mantissa --
3678 --------------------
3680 when Attribute_Model_Mantissa =>
3681 Check_Floating_Point_Type_0;
3682 Set_Etype (N, Universal_Integer);
3688 when Attribute_Model_Small =>
3689 Check_Floating_Point_Type_0;
3690 Set_Etype (N, Universal_Real);
3696 when Attribute_Modulus =>
3698 Check_Modular_Integer_Type;
3699 Set_Etype (N, Universal_Integer);
3701 --------------------
3702 -- Null_Parameter --
3703 --------------------
3705 when Attribute_Null_Parameter => Null_Parameter : declare
3706 Parnt : constant Node_Id := Parent (N);
3707 GParnt : constant Node_Id := Parent (Parnt);
3709 procedure Bad_Null_Parameter (Msg : String);
3710 -- Used if bad Null parameter attribute node is found. Issues
3711 -- given error message, and also sets the type to Any_Type to
3712 -- avoid blowups later on from dealing with a junk node.
3714 procedure Must_Be_Imported (Proc_Ent : Entity_Id);
3715 -- Called to check that Proc_Ent is imported subprogram
3717 ------------------------
3718 -- Bad_Null_Parameter --
3719 ------------------------
3721 procedure Bad_Null_Parameter (Msg : String) is
3723 Error_Msg_N (Msg, N);
3724 Set_Etype (N, Any_Type);
3725 end Bad_Null_Parameter;
3727 ----------------------
3728 -- Must_Be_Imported --
3729 ----------------------
3731 procedure Must_Be_Imported (Proc_Ent : Entity_Id) is
3732 Pent : constant Entity_Id := Ultimate_Alias (Proc_Ent);
3735 -- Ignore check if procedure not frozen yet (we will get
3736 -- another chance when the default parameter is reanalyzed)
3738 if not Is_Frozen (Pent) then
3741 elsif not Is_Imported (Pent) then
3743 ("Null_Parameter can only be used with imported subprogram");
3748 end Must_Be_Imported;
3750 -- Start of processing for Null_Parameter
3755 Set_Etype (N, P_Type);
3757 -- Case of attribute used as default expression
3759 if Nkind (Parnt) = N_Parameter_Specification then
3760 Must_Be_Imported (Defining_Entity (GParnt));
3762 -- Case of attribute used as actual for subprogram (positional)
3764 elsif Nkind_In (Parnt, N_Procedure_Call_Statement,
3766 and then Is_Entity_Name (Name (Parnt))
3768 Must_Be_Imported (Entity (Name (Parnt)));
3770 -- Case of attribute used as actual for subprogram (named)
3772 elsif Nkind (Parnt) = N_Parameter_Association
3773 and then Nkind_In (GParnt, N_Procedure_Call_Statement,
3775 and then Is_Entity_Name (Name (GParnt))
3777 Must_Be_Imported (Entity (Name (GParnt)));
3779 -- Not an allowed case
3783 ("Null_Parameter must be actual or default parameter");
3791 when Attribute_Object_Size =>
3794 Check_Not_Incomplete_Type;
3795 Set_Etype (N, Universal_Integer);
3801 when Attribute_Old =>
3803 -- The attribute reference is a primary. If expressions follow, the
3804 -- attribute reference is an indexable object, so rewrite the node
3807 if Present (E1) then
3809 Make_Indexed_Component (Loc,
3811 Make_Attribute_Reference (Loc,
3812 Prefix => Relocate_Node (Prefix (N)),
3813 Attribute_Name => Name_Old),
3814 Expressions => Expressions (N)));
3822 -- Prefix has not been analyzed yet, and its full analysis will take
3823 -- place during expansion (see below).
3825 Preanalyze_And_Resolve (P);
3826 P_Type := Etype (P);
3827 Set_Etype (N, P_Type);
3829 if No (Current_Subprogram) then
3830 Error_Attr ("attribute % can only appear within subprogram", N);
3833 if Is_Limited_Type (P_Type) then
3834 Error_Attr ("attribute % cannot apply to limited objects", P);
3837 if Is_Entity_Name (P)
3838 and then Is_Constant_Object (Entity (P))
3841 ("?attribute Old applied to constant has no effect", P);
3844 -- Check that the expression does not refer to local entities
3846 Check_Local : declare
3847 Subp : Entity_Id := Current_Subprogram;
3849 function Process (N : Node_Id) return Traverse_Result;
3850 -- Check that N does not contain references to local variables or
3851 -- other local entities of Subp.
3857 function Process (N : Node_Id) return Traverse_Result is
3859 if Is_Entity_Name (N)
3860 and then Present (Entity (N))
3861 and then not Is_Formal (Entity (N))
3862 and then Enclosing_Subprogram (Entity (N)) = Subp
3864 Error_Msg_Node_1 := Entity (N);
3866 ("attribute % cannot refer to local variable&", N);
3872 procedure Check_No_Local is new Traverse_Proc;
3874 -- Start of processing for Check_Local
3879 if In_Parameter_Specification (P) then
3881 -- We have additional restrictions on using 'Old in parameter
3884 if Present (Enclosing_Subprogram (Current_Subprogram)) then
3886 -- Check that there is no reference to the enclosing
3887 -- subprogram local variables. Otherwise, we might end up
3888 -- being called from the enclosing subprogram and thus using
3889 -- 'Old on a local variable which is not defined at entry
3892 Subp := Enclosing_Subprogram (Current_Subprogram);
3896 -- We must prevent default expression of library-level
3897 -- subprogram from using 'Old, as the subprogram may be
3898 -- used in elaboration code for which there is no enclosing
3902 ("attribute % can only appear within subprogram", N);
3907 -- The attribute appears within a pre/postcondition, but refers to
3908 -- an entity in the enclosing subprogram. If it is a component of a
3909 -- formal its expansion might generate actual subtypes that may be
3910 -- referenced in an inner context, and which must be elaborated
3911 -- within the subprogram itself. As a result we create a declaration
3912 -- for it and insert it at the start of the enclosing subprogram
3913 -- This is properly an expansion activity but it has to be performed
3914 -- now to prevent out-of-order issues.
3916 if Nkind (P) = N_Selected_Component
3917 and then Has_Discriminants (Etype (Prefix (P)))
3919 P_Type := Base_Type (P_Type);
3920 Set_Etype (N, P_Type);
3921 Set_Etype (P, P_Type);
3925 ----------------------
3926 -- Overlaps_Storage --
3927 ----------------------
3929 when Attribute_Overlaps_Storage =>
3930 if Ada_Version < Ada_2012 then
3932 ("attribute Overlaps_Storage is an Ada 2012 feature", N);
3934 ("\unit must be compiled with -gnat2012 switch", N);
3938 -- Both arguments must be objects of any type
3940 Analyze_And_Resolve (P);
3941 Analyze_And_Resolve (E1);
3942 Check_Object_Reference (P);
3943 Check_Object_Reference (E1);
3944 Set_Etype (N, Standard_Boolean);
3950 when Attribute_Output =>
3952 Check_Stream_Attribute (TSS_Stream_Output);
3953 Set_Etype (N, Standard_Void_Type);
3954 Resolve (N, Standard_Void_Type);
3960 when Attribute_Partition_ID => Partition_Id :
3964 if P_Type /= Any_Type then
3965 if not Is_Library_Level_Entity (Entity (P)) then
3967 ("prefix of % attribute must be library-level entity");
3969 -- The defining entity of prefix should not be declared inside a
3970 -- Pure unit. RM E.1(8). Is_Pure was set during declaration.
3972 elsif Is_Entity_Name (P)
3973 and then Is_Pure (Entity (P))
3975 Error_Attr_P ("prefix of% attribute must not be declared pure");
3979 Set_Etype (N, Universal_Integer);
3982 -------------------------
3983 -- Passed_By_Reference --
3984 -------------------------
3986 when Attribute_Passed_By_Reference =>
3989 Set_Etype (N, Standard_Boolean);
3995 when Attribute_Pool_Address =>
3997 Set_Etype (N, RTE (RE_Address));
4003 when Attribute_Pos =>
4004 Check_Discrete_Type;
4007 if Is_Boolean_Type (P_Type) then
4008 Error_Msg_Name_1 := Aname;
4009 Error_Msg_Name_2 := Chars (P_Type);
4010 Check_SPARK_Restriction
4011 ("attribute% is not allowed for type%", P);
4014 Resolve (E1, P_Base_Type);
4015 Set_Etype (N, Universal_Integer);
4021 when Attribute_Position =>
4023 Set_Etype (N, Universal_Integer);
4029 when Attribute_Pred =>
4033 if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then
4034 Error_Msg_Name_1 := Aname;
4035 Error_Msg_Name_2 := Chars (P_Type);
4036 Check_SPARK_Restriction
4037 ("attribute% is not allowed for type%", P);
4040 Resolve (E1, P_Base_Type);
4041 Set_Etype (N, P_Base_Type);
4043 -- Nothing to do for real type case
4045 if Is_Real_Type (P_Type) then
4048 -- If not modular type, test for overflow check required
4051 if not Is_Modular_Integer_Type (P_Type)
4052 and then not Range_Checks_Suppressed (P_Base_Type)
4054 Enable_Range_Check (E1);
4062 -- Ada 2005 (AI-327): Dynamic ceiling priorities
4064 when Attribute_Priority =>
4065 if Ada_Version < Ada_2005 then
4066 Error_Attr ("% attribute is allowed only in Ada 2005 mode", P);
4071 -- The prefix must be a protected object (AARM D.5.2 (2/2))
4075 if Is_Protected_Type (Etype (P))
4076 or else (Is_Access_Type (Etype (P))
4077 and then Is_Protected_Type (Designated_Type (Etype (P))))
4079 Resolve (P, Etype (P));
4081 Error_Attr_P ("prefix of % attribute must be a protected object");
4084 Set_Etype (N, Standard_Integer);
4086 -- Must be called from within a protected procedure or entry of the
4087 -- protected object.
4094 while S /= Etype (P)
4095 and then S /= Standard_Standard
4100 if S = Standard_Standard then
4101 Error_Attr ("the attribute % is only allowed inside protected "
4106 Validate_Non_Static_Attribute_Function_Call;
4112 when Attribute_Range =>
4113 Check_Array_Or_Scalar_Type;
4114 Bad_Attribute_For_Predicate;
4116 if Ada_Version = Ada_83
4117 and then Is_Scalar_Type (P_Type)
4118 and then Comes_From_Source (N)
4121 ("(Ada 83) % attribute not allowed for scalar type", P);
4128 when Attribute_Result => Result : declare
4130 -- The enclosing scope, excluding loops for quantified expressions
4133 -- During analysis, CS is the postcondition subprogram and PS the
4134 -- source subprogram to which the postcondition applies. During
4135 -- pre-analysis, CS is the scope of the subprogram declaration.
4138 -- During pre-analysis, Prag is the enclosing pragma node if any
4141 -- Find enclosing scopes, excluding loops
4143 CS := Current_Scope;
4144 while Ekind (CS) = E_Loop loop
4150 -- If the enclosing subprogram is always inlined, the enclosing
4151 -- postcondition will not be propagated to the expanded call.
4153 if not In_Spec_Expression
4154 and then Has_Pragma_Inline_Always (PS)
4155 and then Warn_On_Redundant_Constructs
4158 ("postconditions on inlined functions not enforced?", N);
4161 -- If we are in the scope of a function and in Spec_Expression mode,
4162 -- this is likely the prescan of the postcondition pragma, and we
4163 -- just set the proper type. If there is an error it will be caught
4164 -- when the real Analyze call is done.
4166 if Ekind (CS) = E_Function
4167 and then In_Spec_Expression
4171 if Chars (CS) /= Chars (P) then
4172 Error_Msg_Name_1 := Name_Result;
4175 ("incorrect prefix for % attribute, expected &", P, CS);
4179 -- Check in postcondition of function
4182 while not Nkind_In (Prag, N_Pragma,
4183 N_Function_Specification,
4186 Prag := Parent (Prag);
4189 if Nkind (Prag) /= N_Pragma then
4191 ("% attribute can only appear in postcondition of function",
4194 elsif Get_Pragma_Id (Prag) = Pragma_Test_Case then
4196 Arg_Ens : constant Node_Id :=
4197 Get_Ensures_From_Test_Case_Pragma (Prag);
4202 while Arg /= Prag and Arg /= Arg_Ens loop
4203 Arg := Parent (Arg);
4206 if Arg /= Arg_Ens then
4207 Error_Attr ("% attribute misplaced inside Test_Case", P);
4211 elsif Get_Pragma_Id (Prag) /= Pragma_Postcondition then
4213 ("% attribute can only appear in postcondition of function",
4217 -- The attribute reference is a primary. If expressions follow,
4218 -- the attribute reference is really an indexable object, so
4219 -- rewrite and analyze as an indexed component.
4221 if Present (E1) then
4223 Make_Indexed_Component (Loc,
4225 Make_Attribute_Reference (Loc,
4226 Prefix => Relocate_Node (Prefix (N)),
4227 Attribute_Name => Name_Result),
4228 Expressions => Expressions (N)));
4233 Set_Etype (N, Etype (CS));
4235 -- If several functions with that name are visible,
4236 -- the intended one is the current scope.
4238 if Is_Overloaded (P) then
4240 Set_Is_Overloaded (P, False);
4243 -- Body case, where we must be inside a generated _Postcondition
4244 -- procedure, and the prefix must be on the scope stack, or else
4245 -- the attribute use is definitely misplaced. The condition itself
4246 -- may have generated transient scopes, and is not necessarily the
4250 while Present (CS) and then CS /= Standard_Standard loop
4251 if Chars (CS) = Name_uPostconditions then
4260 if Chars (CS) = Name_uPostconditions
4261 and then Ekind (PS) = E_Function
4265 if Nkind_In (P, N_Identifier, N_Operator_Symbol)
4266 and then Chars (P) = Chars (PS)
4270 -- Within an instance, the prefix designates the local renaming
4271 -- of the original generic.
4273 elsif Is_Entity_Name (P)
4274 and then Ekind (Entity (P)) = E_Function
4275 and then Present (Alias (Entity (P)))
4276 and then Chars (Alias (Entity (P))) = Chars (PS)
4282 ("incorrect prefix for % attribute, expected &", P, PS);
4286 Rewrite (N, Make_Identifier (Sloc (N), Name_uResult));
4287 Analyze_And_Resolve (N, Etype (PS));
4291 ("% attribute can only appear in postcondition of function",
4301 when Attribute_Range_Length =>
4303 Check_Discrete_Type;
4304 Set_Etype (N, Universal_Integer);
4310 when Attribute_Read =>
4312 Check_Stream_Attribute (TSS_Stream_Read);
4313 Set_Etype (N, Standard_Void_Type);
4314 Resolve (N, Standard_Void_Type);
4315 Note_Possible_Modification (E2, Sure => True);
4321 when Attribute_Ref =>
4325 if Nkind (P) /= N_Expanded_Name
4326 or else not Is_RTE (P_Type, RE_Address)
4328 Error_Attr_P ("prefix of % attribute must be System.Address");
4331 Analyze_And_Resolve (E1, Any_Integer);
4332 Set_Etype (N, RTE (RE_Address));
4338 when Attribute_Remainder =>
4339 Check_Floating_Point_Type_2;
4340 Set_Etype (N, P_Base_Type);
4341 Resolve (E1, P_Base_Type);
4342 Resolve (E2, P_Base_Type);
4348 when Attribute_Round =>
4350 Check_Decimal_Fixed_Point_Type;
4351 Set_Etype (N, P_Base_Type);
4353 -- Because the context is universal_real (3.5.10(12)) it is a legal
4354 -- context for a universal fixed expression. This is the only
4355 -- attribute whose functional description involves U_R.
4357 if Etype (E1) = Universal_Fixed then
4359 Conv : constant Node_Id := Make_Type_Conversion (Loc,
4360 Subtype_Mark => New_Occurrence_Of (Universal_Real, Loc),
4361 Expression => Relocate_Node (E1));
4369 Resolve (E1, Any_Real);
4375 when Attribute_Rounding =>
4376 Check_Floating_Point_Type_1;
4377 Set_Etype (N, P_Base_Type);
4378 Resolve (E1, P_Base_Type);
4384 when Attribute_Safe_Emax =>
4385 Check_Floating_Point_Type_0;
4386 Set_Etype (N, Universal_Integer);
4392 when Attribute_Safe_First =>
4393 Check_Floating_Point_Type_0;
4394 Set_Etype (N, Universal_Real);
4400 when Attribute_Safe_Large =>
4403 Set_Etype (N, Universal_Real);
4409 when Attribute_Safe_Last =>
4410 Check_Floating_Point_Type_0;
4411 Set_Etype (N, Universal_Real);
4417 when Attribute_Safe_Small =>
4420 Set_Etype (N, Universal_Real);
4426 when Attribute_Same_Storage =>
4427 if Ada_Version < Ada_2012 then
4429 ("attribute Same_Storage is an Ada 2012 feature", N);
4431 ("\unit must be compiled with -gnat2012 switch", N);
4436 -- The arguments must be objects of any type
4438 Analyze_And_Resolve (P);
4439 Analyze_And_Resolve (E1);
4440 Check_Object_Reference (P);
4441 Check_Object_Reference (E1);
4442 Set_Etype (N, Standard_Boolean);
4448 when Attribute_Scale =>
4450 Check_Decimal_Fixed_Point_Type;
4451 Set_Etype (N, Universal_Integer);
4457 when Attribute_Scaling =>
4458 Check_Floating_Point_Type_2;
4459 Set_Etype (N, P_Base_Type);
4460 Resolve (E1, P_Base_Type);
4466 when Attribute_Signed_Zeros =>
4467 Check_Floating_Point_Type_0;
4468 Set_Etype (N, Standard_Boolean);
4474 when Attribute_Size | Attribute_VADS_Size => Size :
4478 -- If prefix is parameterless function call, rewrite and resolve
4481 if Is_Entity_Name (P)
4482 and then Ekind (Entity (P)) = E_Function
4486 -- Similar processing for a protected function call
4488 elsif Nkind (P) = N_Selected_Component
4489 and then Ekind (Entity (Selector_Name (P))) = E_Function
4494 if Is_Object_Reference (P) then
4495 Check_Object_Reference (P);
4497 elsif Is_Entity_Name (P)
4498 and then (Is_Type (Entity (P))
4499 or else Ekind (Entity (P)) = E_Enumeration_Literal)
4503 elsif Nkind (P) = N_Type_Conversion
4504 and then not Comes_From_Source (P)
4509 Error_Attr_P ("invalid prefix for % attribute");
4512 Check_Not_Incomplete_Type;
4514 Set_Etype (N, Universal_Integer);
4521 when Attribute_Small =>
4524 Set_Etype (N, Universal_Real);
4530 when Attribute_Storage_Pool => Storage_Pool :
4534 if Is_Access_Type (P_Type) then
4535 if Ekind (P_Type) = E_Access_Subprogram_Type then
4537 ("cannot use % attribute for access-to-subprogram type");
4540 -- Set appropriate entity
4542 if Present (Associated_Storage_Pool (Root_Type (P_Type))) then
4543 Set_Entity (N, Associated_Storage_Pool (Root_Type (P_Type)));
4545 Set_Entity (N, RTE (RE_Global_Pool_Object));
4548 Set_Etype (N, Class_Wide_Type (RTE (RE_Root_Storage_Pool)));
4550 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4551 -- Storage_Pool since this attribute is not defined for such
4552 -- types (RM E.2.3(22)).
4554 Validate_Remote_Access_To_Class_Wide_Type (N);
4557 Error_Attr_P ("prefix of % attribute must be access type");
4565 when Attribute_Storage_Size => Storage_Size :
4569 if Is_Task_Type (P_Type) then
4570 Set_Etype (N, Universal_Integer);
4572 -- Use with tasks is an obsolescent feature
4574 Check_Restriction (No_Obsolescent_Features, P);
4576 elsif Is_Access_Type (P_Type) then
4577 if Ekind (P_Type) = E_Access_Subprogram_Type then
4579 ("cannot use % attribute for access-to-subprogram type");
4582 if Is_Entity_Name (P)
4583 and then Is_Type (Entity (P))
4586 Set_Etype (N, Universal_Integer);
4588 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4589 -- Storage_Size since this attribute is not defined for
4590 -- such types (RM E.2.3(22)).
4592 Validate_Remote_Access_To_Class_Wide_Type (N);
4594 -- The prefix is allowed to be an implicit dereference
4595 -- of an access value designating a task.
4599 Set_Etype (N, Universal_Integer);
4603 Error_Attr_P ("prefix of % attribute must be access or task type");
4611 when Attribute_Storage_Unit =>
4612 Standard_Attribute (Ttypes.System_Storage_Unit);
4618 when Attribute_Stream_Size =>
4622 if Is_Entity_Name (P)
4623 and then Is_Elementary_Type (Entity (P))
4625 Set_Etype (N, Universal_Integer);
4627 Error_Attr_P ("invalid prefix for % attribute");
4634 when Attribute_Stub_Type =>
4638 if Is_Remote_Access_To_Class_Wide_Type (P_Type) then
4640 New_Occurrence_Of (Corresponding_Stub_Type (P_Type), Loc));
4643 ("prefix of% attribute must be remote access to classwide");
4650 when Attribute_Succ =>
4654 if Is_Real_Type (P_Type) or else Is_Boolean_Type (P_Type) then
4655 Error_Msg_Name_1 := Aname;
4656 Error_Msg_Name_2 := Chars (P_Type);
4657 Check_SPARK_Restriction
4658 ("attribute% is not allowed for type%", P);
4661 Resolve (E1, P_Base_Type);
4662 Set_Etype (N, P_Base_Type);
4664 -- Nothing to do for real type case
4666 if Is_Real_Type (P_Type) then
4669 -- If not modular type, test for overflow check required
4672 if not Is_Modular_Integer_Type (P_Type)
4673 and then not Range_Checks_Suppressed (P_Base_Type)
4675 Enable_Range_Check (E1);
4679 --------------------------------
4680 -- System_Allocator_Alignment --
4681 --------------------------------
4683 when Attribute_System_Allocator_Alignment =>
4684 Standard_Attribute (Ttypes.System_Allocator_Alignment);
4690 when Attribute_Tag => Tag :
4695 if not Is_Tagged_Type (P_Type) then
4696 Error_Attr_P ("prefix of % attribute must be tagged");
4698 -- Next test does not apply to generated code
4699 -- why not, and what does the illegal reference mean???
4701 elsif Is_Object_Reference (P)
4702 and then not Is_Class_Wide_Type (P_Type)
4703 and then Comes_From_Source (N)
4706 ("% attribute can only be applied to objects " &
4707 "of class - wide type");
4710 -- The prefix cannot be an incomplete type. However, references
4711 -- to 'Tag can be generated when expanding interface conversions,
4712 -- and this is legal.
4714 if Comes_From_Source (N) then
4715 Check_Not_Incomplete_Type;
4718 -- Set appropriate type
4720 Set_Etype (N, RTE (RE_Tag));
4727 when Attribute_Target_Name => Target_Name : declare
4728 TN : constant String := Sdefault.Target_Name.all;
4732 Check_Standard_Prefix;
4736 if TN (TL) = '/' or else TN (TL) = '\' then
4741 Make_String_Literal (Loc,
4742 Strval => TN (TN'First .. TL)));
4743 Analyze_And_Resolve (N, Standard_String);
4750 when Attribute_Terminated =>
4752 Set_Etype (N, Standard_Boolean);
4759 when Attribute_To_Address =>
4763 if Nkind (P) /= N_Identifier
4764 or else Chars (P) /= Name_System
4766 Error_Attr_P ("prefix of % attribute must be System");
4769 Generate_Reference (RTE (RE_Address), P);
4770 Analyze_And_Resolve (E1, Any_Integer);
4771 Set_Etype (N, RTE (RE_Address));
4777 when Attribute_To_Any =>
4779 Check_PolyORB_Attribute;
4780 Set_Etype (N, RTE (RE_Any));
4786 when Attribute_Truncation =>
4787 Check_Floating_Point_Type_1;
4788 Resolve (E1, P_Base_Type);
4789 Set_Etype (N, P_Base_Type);
4795 when Attribute_Type_Class =>
4798 Check_Not_Incomplete_Type;
4799 Set_Etype (N, RTE (RE_Type_Class));
4805 when Attribute_TypeCode =>
4807 Check_PolyORB_Attribute;
4808 Set_Etype (N, RTE (RE_TypeCode));
4814 when Attribute_Type_Key =>
4818 -- This processing belongs in Eval_Attribute ???
4821 function Type_Key return String_Id;
4822 -- A very preliminary implementation. For now, a signature
4823 -- consists of only the type name. This is clearly incomplete
4824 -- (e.g., adding a new field to a record type should change the
4825 -- type's Type_Key attribute).
4831 function Type_Key return String_Id is
4832 Full_Name : constant String_Id :=
4833 Fully_Qualified_Name_String (Entity (P));
4836 -- Copy all characters in Full_Name but the trailing NUL
4839 for J in 1 .. String_Length (Full_Name) - 1 loop
4840 Store_String_Char (Get_String_Char (Full_Name, Int (J)));
4843 Store_String_Chars ("'Type_Key");
4848 Rewrite (N, Make_String_Literal (Loc, Type_Key));
4851 Analyze_And_Resolve (N, Standard_String);
4857 when Attribute_UET_Address =>
4859 Check_Unit_Name (P);
4860 Set_Etype (N, RTE (RE_Address));
4862 -----------------------
4863 -- Unbiased_Rounding --
4864 -----------------------
4866 when Attribute_Unbiased_Rounding =>
4867 Check_Floating_Point_Type_1;
4868 Set_Etype (N, P_Base_Type);
4869 Resolve (E1, P_Base_Type);
4871 ----------------------
4872 -- Unchecked_Access --
4873 ----------------------
4875 when Attribute_Unchecked_Access =>
4876 if Comes_From_Source (N) then
4877 Check_Restriction (No_Unchecked_Access, N);
4880 Analyze_Access_Attribute;
4882 -------------------------
4883 -- Unconstrained_Array --
4884 -------------------------
4886 when Attribute_Unconstrained_Array =>
4889 Check_Not_Incomplete_Type;
4890 Set_Etype (N, Standard_Boolean);
4892 ------------------------------
4893 -- Universal_Literal_String --
4894 ------------------------------
4896 -- This is a GNAT specific attribute whose prefix must be a named
4897 -- number where the expression is either a single numeric literal,
4898 -- or a numeric literal immediately preceded by a minus sign. The
4899 -- result is equivalent to a string literal containing the text of
4900 -- the literal as it appeared in the source program with a possible
4901 -- leading minus sign.
4903 when Attribute_Universal_Literal_String => Universal_Literal_String :
4907 if not Is_Entity_Name (P)
4908 or else Ekind (Entity (P)) not in Named_Kind
4910 Error_Attr_P ("prefix for % attribute must be named number");
4917 Src : Source_Buffer_Ptr;
4920 Expr := Original_Node (Expression (Parent (Entity (P))));
4922 if Nkind (Expr) = N_Op_Minus then
4924 Expr := Original_Node (Right_Opnd (Expr));
4929 if not Nkind_In (Expr, N_Integer_Literal, N_Real_Literal) then
4931 ("named number for % attribute must be simple literal", N);
4934 -- Build string literal corresponding to source literal text
4939 Store_String_Char (Get_Char_Code ('-'));
4943 Src := Source_Text (Get_Source_File_Index (S));
4945 while Src (S) /= ';' and then Src (S) /= ' ' loop
4946 Store_String_Char (Get_Char_Code (Src (S)));
4950 -- Now we rewrite the attribute with the string literal
4953 Make_String_Literal (Loc, End_String));
4957 end Universal_Literal_String;
4959 -------------------------
4960 -- Unrestricted_Access --
4961 -------------------------
4963 -- This is a GNAT specific attribute which is like Access except that
4964 -- all scope checks and checks for aliased views are omitted.
4966 when Attribute_Unrestricted_Access =>
4968 -- If from source, deal with relevant restrictions
4970 if Comes_From_Source (N) then
4971 Check_Restriction (No_Unchecked_Access, N);
4973 if Nkind (P) in N_Has_Entity
4974 and then Present (Entity (P))
4975 and then Is_Object (Entity (P))
4977 Check_Restriction (No_Implicit_Aliasing, N);
4981 if Is_Entity_Name (P) then
4982 Set_Address_Taken (Entity (P));
4985 Analyze_Access_Attribute;
4991 when Attribute_Val => Val : declare
4994 Check_Discrete_Type;
4996 if Is_Boolean_Type (P_Type) then
4997 Error_Msg_Name_1 := Aname;
4998 Error_Msg_Name_2 := Chars (P_Type);
4999 Check_SPARK_Restriction
5000 ("attribute% is not allowed for type%", P);
5003 Resolve (E1, Any_Integer);
5004 Set_Etype (N, P_Base_Type);
5006 -- Note, we need a range check in general, but we wait for the
5007 -- Resolve call to do this, since we want to let Eval_Attribute
5008 -- have a chance to find an static illegality first!
5015 when Attribute_Valid =>
5018 -- Ignore check for object if we have a 'Valid reference generated
5019 -- by the expanded code, since in some cases valid checks can occur
5020 -- on items that are names, but are not objects (e.g. attributes).
5022 if Comes_From_Source (N) then
5023 Check_Object_Reference (P);
5026 if not Is_Scalar_Type (P_Type) then
5027 Error_Attr_P ("object for % attribute must be of scalar type");
5030 Set_Etype (N, Standard_Boolean);
5036 when Attribute_Value => Value :
5038 Check_SPARK_Restriction_On_Attribute;
5042 -- Case of enumeration type
5044 -- When an enumeration type appears in an attribute reference, all
5045 -- literals of the type are marked as referenced. This must only be
5046 -- done if the attribute reference appears in the current source.
5047 -- Otherwise the information on references may differ between a
5048 -- normal compilation and one that performs inlining.
5050 if Is_Enumeration_Type (P_Type)
5051 and then In_Extended_Main_Code_Unit (N)
5053 Check_Restriction (No_Enumeration_Maps, N);
5055 -- Mark all enumeration literals as referenced, since the use of
5056 -- the Value attribute can implicitly reference any of the
5057 -- literals of the enumeration base type.
5060 Ent : Entity_Id := First_Literal (P_Base_Type);
5062 while Present (Ent) loop
5063 Set_Referenced (Ent);
5069 -- Set Etype before resolving expression because expansion of
5070 -- expression may require enclosing type. Note that the type
5071 -- returned by 'Value is the base type of the prefix type.
5073 Set_Etype (N, P_Base_Type);
5074 Validate_Non_Static_Attribute_Function_Call;
5081 when Attribute_Value_Size =>
5084 Check_Not_Incomplete_Type;
5085 Set_Etype (N, Universal_Integer);
5091 when Attribute_Version =>
5094 Set_Etype (N, RTE (RE_Version_String));
5100 when Attribute_Wchar_T_Size =>
5101 Standard_Attribute (Interfaces_Wchar_T_Size);
5107 when Attribute_Wide_Image => Wide_Image :
5109 Check_SPARK_Restriction_On_Attribute;
5111 Set_Etype (N, Standard_Wide_String);
5113 Resolve (E1, P_Base_Type);
5114 Validate_Non_Static_Attribute_Function_Call;
5117 ---------------------
5118 -- Wide_Wide_Image --
5119 ---------------------
5121 when Attribute_Wide_Wide_Image => Wide_Wide_Image :
5124 Set_Etype (N, Standard_Wide_Wide_String);
5126 Resolve (E1, P_Base_Type);
5127 Validate_Non_Static_Attribute_Function_Call;
5128 end Wide_Wide_Image;
5134 when Attribute_Wide_Value => Wide_Value :
5136 Check_SPARK_Restriction_On_Attribute;
5140 -- Set Etype before resolving expression because expansion
5141 -- of expression may require enclosing type.
5143 Set_Etype (N, P_Type);
5144 Validate_Non_Static_Attribute_Function_Call;
5147 ---------------------
5148 -- Wide_Wide_Value --
5149 ---------------------
5151 when Attribute_Wide_Wide_Value => Wide_Wide_Value :
5156 -- Set Etype before resolving expression because expansion
5157 -- of expression may require enclosing type.
5159 Set_Etype (N, P_Type);
5160 Validate_Non_Static_Attribute_Function_Call;
5161 end Wide_Wide_Value;
5163 ---------------------
5164 -- Wide_Wide_Width --
5165 ---------------------
5167 when Attribute_Wide_Wide_Width =>
5170 Set_Etype (N, Universal_Integer);
5176 when Attribute_Wide_Width =>
5177 Check_SPARK_Restriction_On_Attribute;
5180 Set_Etype (N, Universal_Integer);
5186 when Attribute_Width =>
5187 Check_SPARK_Restriction_On_Attribute;
5190 Set_Etype (N, Universal_Integer);
5196 when Attribute_Word_Size =>
5197 Standard_Attribute (System_Word_Size);
5203 when Attribute_Write =>
5205 Check_Stream_Attribute (TSS_Stream_Write);
5206 Set_Etype (N, Standard_Void_Type);
5207 Resolve (N, Standard_Void_Type);
5211 -- All errors raise Bad_Attribute, so that we get out before any further
5212 -- damage occurs when an error is detected (for example, if we check for
5213 -- one attribute expression, and the check succeeds, we want to be able
5214 -- to proceed securely assuming that an expression is in fact present.
5216 -- Note: we set the attribute analyzed in this case to prevent any
5217 -- attempt at reanalysis which could generate spurious error msgs.
5220 when Bad_Attribute =>
5222 Set_Etype (N, Any_Type);
5224 end Analyze_Attribute;
5226 --------------------
5227 -- Eval_Attribute --
5228 --------------------
5230 procedure Eval_Attribute (N : Node_Id) is
5231 Loc : constant Source_Ptr := Sloc (N);
5232 Aname : constant Name_Id := Attribute_Name (N);
5233 Id : constant Attribute_Id := Get_Attribute_Id (Aname);
5234 P : constant Node_Id := Prefix (N);
5236 C_Type : constant Entity_Id := Etype (N);
5237 -- The type imposed by the context
5240 -- First expression, or Empty if none
5243 -- Second expression, or Empty if none
5245 P_Entity : Entity_Id;
5246 -- Entity denoted by prefix
5249 -- The type of the prefix
5251 P_Base_Type : Entity_Id;
5252 -- The base type of the prefix type
5254 P_Root_Type : Entity_Id;
5255 -- The root type of the prefix type
5258 -- True if the result is Static. This is set by the general processing
5259 -- to true if the prefix is static, and all expressions are static. It
5260 -- can be reset as processing continues for particular attributes
5262 Lo_Bound, Hi_Bound : Node_Id;
5263 -- Expressions for low and high bounds of type or array index referenced
5264 -- by First, Last, or Length attribute for array, set by Set_Bounds.
5267 -- Constraint error node used if we have an attribute reference has
5268 -- an argument that raises a constraint error. In this case we replace
5269 -- the attribute with a raise constraint_error node. This is important
5270 -- processing, since otherwise gigi might see an attribute which it is
5271 -- unprepared to deal with.
5273 procedure Check_Concurrent_Discriminant (Bound : Node_Id);
5274 -- If Bound is a reference to a discriminant of a task or protected type
5275 -- occurring within the object's body, rewrite attribute reference into
5276 -- a reference to the corresponding discriminal. Use for the expansion
5277 -- of checks against bounds of entry family index subtypes.
5279 procedure Check_Expressions;
5280 -- In case where the attribute is not foldable, the expressions, if
5281 -- any, of the attribute, are in a non-static context. This procedure
5282 -- performs the required additional checks.
5284 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean;
5285 -- Determines if the given type has compile time known bounds. Note
5286 -- that we enter the case statement even in cases where the prefix
5287 -- type does NOT have known bounds, so it is important to guard any
5288 -- attempt to evaluate both bounds with a call to this function.
5290 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint);
5291 -- This procedure is called when the attribute N has a non-static
5292 -- but compile time known value given by Val. It includes the
5293 -- necessary checks for out of range values.
5295 function Fore_Value return Nat;
5296 -- Computes the Fore value for the current attribute prefix, which is
5297 -- known to be a static fixed-point type. Used by Fore and Width.
5299 function Is_VAX_Float (Typ : Entity_Id) return Boolean;
5300 -- Determine whether Typ denotes a VAX floating point type
5302 function Mantissa return Uint;
5303 -- Returns the Mantissa value for the prefix type
5305 procedure Set_Bounds;
5306 -- Used for First, Last and Length attributes applied to an array or
5307 -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low
5308 -- and high bound expressions for the index referenced by the attribute
5309 -- designator (i.e. the first index if no expression is present, and
5310 -- the N'th index if the value N is present as an expression). Also
5311 -- used for First and Last of scalar types. Static is reset to False
5312 -- if the type or index type is not statically constrained.
5314 function Statically_Denotes_Entity (N : Node_Id) return Boolean;
5315 -- Verify that the prefix of a potentially static array attribute
5316 -- satisfies the conditions of 4.9 (14).
5318 -----------------------------------
5319 -- Check_Concurrent_Discriminant --
5320 -----------------------------------
5322 procedure Check_Concurrent_Discriminant (Bound : Node_Id) is
5324 -- The concurrent (task or protected) type
5327 if Nkind (Bound) = N_Identifier
5328 and then Ekind (Entity (Bound)) = E_Discriminant
5329 and then Is_Concurrent_Record_Type (Scope (Entity (Bound)))
5331 Tsk := Corresponding_Concurrent_Type (Scope (Entity (Bound)));
5333 if In_Open_Scopes (Tsk) and then Has_Completion (Tsk) then
5335 -- Find discriminant of original concurrent type, and use
5336 -- its current discriminal, which is the renaming within
5337 -- the task/protected body.
5341 (Find_Body_Discriminal (Entity (Bound)), Loc));
5344 end Check_Concurrent_Discriminant;
5346 -----------------------
5347 -- Check_Expressions --
5348 -----------------------
5350 procedure Check_Expressions is
5354 while Present (E) loop
5355 Check_Non_Static_Context (E);
5358 end Check_Expressions;
5360 ----------------------------------
5361 -- Compile_Time_Known_Attribute --
5362 ----------------------------------
5364 procedure Compile_Time_Known_Attribute (N : Node_Id; Val : Uint) is
5365 T : constant Entity_Id := Etype (N);
5368 Fold_Uint (N, Val, False);
5370 -- Check that result is in bounds of the type if it is static
5372 if Is_In_Range (N, T, Assume_Valid => False) then
5375 elsif Is_Out_Of_Range (N, T) then
5376 Apply_Compile_Time_Constraint_Error
5377 (N, "value not in range of}?", CE_Range_Check_Failed);
5379 elsif not Range_Checks_Suppressed (T) then
5380 Enable_Range_Check (N);
5383 Set_Do_Range_Check (N, False);
5385 end Compile_Time_Known_Attribute;
5387 -------------------------------
5388 -- Compile_Time_Known_Bounds --
5389 -------------------------------
5391 function Compile_Time_Known_Bounds (Typ : Entity_Id) return Boolean is
5394 Compile_Time_Known_Value (Type_Low_Bound (Typ))
5396 Compile_Time_Known_Value (Type_High_Bound (Typ));
5397 end Compile_Time_Known_Bounds;
5403 -- Note that the Fore calculation is based on the actual values
5404 -- of the bounds, and does not take into account possible rounding.
5406 function Fore_Value return Nat is
5407 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
5408 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
5409 Small : constant Ureal := Small_Value (P_Type);
5410 Lo_Real : constant Ureal := Lo * Small;
5411 Hi_Real : constant Ureal := Hi * Small;
5416 -- Bounds are given in terms of small units, so first compute
5417 -- proper values as reals.
5419 T := UR_Max (abs Lo_Real, abs Hi_Real);
5422 -- Loop to compute proper value if more than one digit required
5424 while T >= Ureal_10 loop
5436 function Is_VAX_Float (Typ : Entity_Id) return Boolean is
5439 Is_Floating_Point_Type (Typ)
5442 or else Float_Rep (Typ) = VAX_Native);
5449 -- Table of mantissa values accessed by function Computed using
5452 -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1)
5454 -- where D is T'Digits (RM83 3.5.7)
5456 Mantissa_Value : constant array (Nat range 1 .. 40) of Nat := (
5498 function Mantissa return Uint is
5501 UI_From_Int (Mantissa_Value (UI_To_Int (Digits_Value (P_Type))));
5508 procedure Set_Bounds is
5514 -- For a string literal subtype, we have to construct the bounds.
5515 -- Valid Ada code never applies attributes to string literals, but
5516 -- it is convenient to allow the expander to generate attribute
5517 -- references of this type (e.g. First and Last applied to a string
5520 -- Note that the whole point of the E_String_Literal_Subtype is to
5521 -- avoid this construction of bounds, but the cases in which we
5522 -- have to materialize them are rare enough that we don't worry!
5524 -- The low bound is simply the low bound of the base type. The
5525 -- high bound is computed from the length of the string and this
5528 if Ekind (P_Type) = E_String_Literal_Subtype then
5529 Ityp := Etype (First_Index (Base_Type (P_Type)));
5530 Lo_Bound := Type_Low_Bound (Ityp);
5533 Make_Integer_Literal (Sloc (P),
5535 Expr_Value (Lo_Bound) + String_Literal_Length (P_Type) - 1);
5537 Set_Parent (Hi_Bound, P);
5538 Analyze_And_Resolve (Hi_Bound, Etype (Lo_Bound));
5541 -- For non-array case, just get bounds of scalar type
5543 elsif Is_Scalar_Type (P_Type) then
5546 -- For a fixed-point type, we must freeze to get the attributes
5547 -- of the fixed-point type set now so we can reference them.
5549 if Is_Fixed_Point_Type (P_Type)
5550 and then not Is_Frozen (Base_Type (P_Type))
5551 and then Compile_Time_Known_Value (Type_Low_Bound (P_Type))
5552 and then Compile_Time_Known_Value (Type_High_Bound (P_Type))
5554 Freeze_Fixed_Point_Type (Base_Type (P_Type));
5557 -- For array case, get type of proper index
5563 Ndim := UI_To_Int (Expr_Value (E1));
5566 Indx := First_Index (P_Type);
5567 for J in 1 .. Ndim - 1 loop
5571 -- If no index type, get out (some other error occurred, and
5572 -- we don't have enough information to complete the job!)
5580 Ityp := Etype (Indx);
5583 -- A discrete range in an index constraint is allowed to be a
5584 -- subtype indication. This is syntactically a pain, but should
5585 -- not propagate to the entity for the corresponding index subtype.
5586 -- After checking that the subtype indication is legal, the range
5587 -- of the subtype indication should be transfered to the entity.
5588 -- The attributes for the bounds should remain the simple retrievals
5589 -- that they are now.
5591 Lo_Bound := Type_Low_Bound (Ityp);
5592 Hi_Bound := Type_High_Bound (Ityp);
5594 if not Is_Static_Subtype (Ityp) then
5599 -------------------------------
5600 -- Statically_Denotes_Entity --
5601 -------------------------------
5603 function Statically_Denotes_Entity (N : Node_Id) return Boolean is
5607 if not Is_Entity_Name (N) then
5614 Nkind (Parent (E)) /= N_Object_Renaming_Declaration
5615 or else Statically_Denotes_Entity (Renamed_Object (E));
5616 end Statically_Denotes_Entity;
5618 -- Start of processing for Eval_Attribute
5621 -- No folding in spec expression that comes from source where the prefix
5622 -- is an unfrozen entity. This avoids premature folding in cases like:
5624 -- procedure DefExprAnal is
5625 -- type R is new Integer;
5626 -- procedure P (Arg : Integer := R'Size);
5627 -- for R'Size use 64;
5628 -- procedure P (Arg : Integer := R'Size) is
5630 -- Put_Line (Arg'Img);
5636 -- which should print 64 rather than 32. The exclusion of non-source
5637 -- constructs from this test comes from some internal usage in packed
5638 -- arrays, which otherwise fails, could use more analysis perhaps???
5640 -- We do however go ahead with generic actual types, otherwise we get
5641 -- some regressions, probably these types should be frozen anyway???
5643 if In_Spec_Expression
5644 and then Comes_From_Source (N)
5645 and then not (Is_Entity_Name (P)
5647 (Is_Frozen (Entity (P))
5648 or else (Is_Type (Entity (P))
5650 Is_Generic_Actual_Type (Entity (P)))))
5655 -- Acquire first two expressions (at the moment, no attributes take more
5656 -- than two expressions in any case).
5658 if Present (Expressions (N)) then
5659 E1 := First (Expressions (N));
5666 -- Special processing for Enabled attribute. This attribute has a very
5667 -- special prefix, and the easiest way to avoid lots of special checks
5668 -- to protect this special prefix from causing trouble is to deal with
5669 -- this attribute immediately and be done with it.
5671 if Id = Attribute_Enabled then
5673 -- We skip evaluation if the expander is not active. This is not just
5674 -- an optimization. It is of key importance that we not rewrite the
5675 -- attribute in a generic template, since we want to pick up the
5676 -- setting of the check in the instance, and testing expander active
5677 -- is as easy way of doing this as any.
5679 if Expander_Active then
5681 C : constant Check_Id := Get_Check_Id (Chars (P));
5686 if C in Predefined_Check_Id then
5687 R := Scope_Suppress (C);
5689 R := Is_Check_Suppressed (Empty, C);
5693 R := Is_Check_Suppressed (Entity (E1), C);
5697 Rewrite (N, New_Occurrence_Of (Standard_False, Loc));
5699 Rewrite (N, New_Occurrence_Of (Standard_True, Loc));
5707 -- Special processing for cases where the prefix is an object. For
5708 -- this purpose, a string literal counts as an object (attributes
5709 -- of string literals can only appear in generated code).
5711 if Is_Object_Reference (P) or else Nkind (P) = N_String_Literal then
5713 -- For Component_Size, the prefix is an array object, and we apply
5714 -- the attribute to the type of the object. This is allowed for
5715 -- both unconstrained and constrained arrays, since the bounds
5716 -- have no influence on the value of this attribute.
5718 if Id = Attribute_Component_Size then
5719 P_Entity := Etype (P);
5721 -- For First and Last, the prefix is an array object, and we apply
5722 -- the attribute to the type of the array, but we need a constrained
5723 -- type for this, so we use the actual subtype if available.
5725 elsif Id = Attribute_First
5729 Id = Attribute_Length
5732 AS : constant Entity_Id := Get_Actual_Subtype_If_Available (P);
5735 if Present (AS) and then Is_Constrained (AS) then
5738 -- If we have an unconstrained type we cannot fold
5746 -- For Size, give size of object if available, otherwise we
5747 -- cannot fold Size.
5749 elsif Id = Attribute_Size then
5750 if Is_Entity_Name (P)
5751 and then Known_Esize (Entity (P))
5753 Compile_Time_Known_Attribute (N, Esize (Entity (P)));
5761 -- For Alignment, give size of object if available, otherwise we
5762 -- cannot fold Alignment.
5764 elsif Id = Attribute_Alignment then
5765 if Is_Entity_Name (P)
5766 and then Known_Alignment (Entity (P))
5768 Fold_Uint (N, Alignment (Entity (P)), False);
5776 -- No other attributes for objects are folded
5783 -- Cases where P is not an object. Cannot do anything if P is
5784 -- not the name of an entity.
5786 elsif not Is_Entity_Name (P) then
5790 -- Otherwise get prefix entity
5793 P_Entity := Entity (P);
5796 -- At this stage P_Entity is the entity to which the attribute
5797 -- is to be applied. This is usually simply the entity of the
5798 -- prefix, except in some cases of attributes for objects, where
5799 -- as described above, we apply the attribute to the object type.
5801 -- First foldable possibility is a scalar or array type (RM 4.9(7))
5802 -- that is not generic (generic types are eliminated by RM 4.9(25)).
5803 -- Note we allow non-static non-generic types at this stage as further
5806 if Is_Type (P_Entity)
5807 and then (Is_Scalar_Type (P_Entity) or Is_Array_Type (P_Entity))
5808 and then (not Is_Generic_Type (P_Entity))
5812 -- Second foldable possibility is an array object (RM 4.9(8))
5814 elsif (Ekind (P_Entity) = E_Variable
5816 Ekind (P_Entity) = E_Constant)
5817 and then Is_Array_Type (Etype (P_Entity))
5818 and then (not Is_Generic_Type (Etype (P_Entity)))
5820 P_Type := Etype (P_Entity);
5822 -- If the entity is an array constant with an unconstrained nominal
5823 -- subtype then get the type from the initial value. If the value has
5824 -- been expanded into assignments, there is no expression and the
5825 -- attribute reference remains dynamic.
5827 -- We could do better here and retrieve the type ???
5829 if Ekind (P_Entity) = E_Constant
5830 and then not Is_Constrained (P_Type)
5832 if No (Constant_Value (P_Entity)) then
5835 P_Type := Etype (Constant_Value (P_Entity));
5839 -- Definite must be folded if the prefix is not a generic type,
5840 -- that is to say if we are within an instantiation. Same processing
5841 -- applies to the GNAT attributes Has_Discriminants, Type_Class,
5842 -- Has_Tagged_Value, and Unconstrained_Array.
5844 elsif (Id = Attribute_Definite
5846 Id = Attribute_Has_Access_Values
5848 Id = Attribute_Has_Discriminants
5850 Id = Attribute_Has_Tagged_Values
5852 Id = Attribute_Type_Class
5854 Id = Attribute_Unconstrained_Array
5856 Id = Attribute_Max_Alignment_For_Allocation)
5857 and then not Is_Generic_Type (P_Entity)
5861 -- We can fold 'Size applied to a type if the size is known (as happens
5862 -- for a size from an attribute definition clause). At this stage, this
5863 -- can happen only for types (e.g. record types) for which the size is
5864 -- always non-static. We exclude generic types from consideration (since
5865 -- they have bogus sizes set within templates).
5867 elsif Id = Attribute_Size
5868 and then Is_Type (P_Entity)
5869 and then (not Is_Generic_Type (P_Entity))
5870 and then Known_Static_RM_Size (P_Entity)
5872 Compile_Time_Known_Attribute (N, RM_Size (P_Entity));
5875 -- We can fold 'Alignment applied to a type if the alignment is known
5876 -- (as happens for an alignment from an attribute definition clause).
5877 -- At this stage, this can happen only for types (e.g. record
5878 -- types) for which the size is always non-static. We exclude
5879 -- generic types from consideration (since they have bogus
5880 -- sizes set within templates).
5882 elsif Id = Attribute_Alignment
5883 and then Is_Type (P_Entity)
5884 and then (not Is_Generic_Type (P_Entity))
5885 and then Known_Alignment (P_Entity)
5887 Compile_Time_Known_Attribute (N, Alignment (P_Entity));
5890 -- If this is an access attribute that is known to fail accessibility
5891 -- check, rewrite accordingly.
5893 elsif Attribute_Name (N) = Name_Access
5894 and then Raises_Constraint_Error (N)
5897 Make_Raise_Program_Error (Loc,
5898 Reason => PE_Accessibility_Check_Failed));
5899 Set_Etype (N, C_Type);
5902 -- No other cases are foldable (they certainly aren't static, and at
5903 -- the moment we don't try to fold any cases other than these three).
5910 -- If either attribute or the prefix is Any_Type, then propagate
5911 -- Any_Type to the result and don't do anything else at all.
5913 if P_Type = Any_Type
5914 or else (Present (E1) and then Etype (E1) = Any_Type)
5915 or else (Present (E2) and then Etype (E2) = Any_Type)
5917 Set_Etype (N, Any_Type);
5921 -- Scalar subtype case. We have not yet enforced the static requirement
5922 -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases
5923 -- of non-static attribute references (e.g. S'Digits for a non-static
5924 -- floating-point type, which we can compute at compile time).
5926 -- Note: this folding of non-static attributes is not simply a case of
5927 -- optimization. For many of the attributes affected, Gigi cannot handle
5928 -- the attribute and depends on the front end having folded them away.
5930 -- Note: although we don't require staticness at this stage, we do set
5931 -- the Static variable to record the staticness, for easy reference by
5932 -- those attributes where it matters (e.g. Succ and Pred), and also to
5933 -- be used to ensure that non-static folded things are not marked as
5934 -- being static (a check that is done right at the end).
5936 P_Root_Type := Root_Type (P_Type);
5937 P_Base_Type := Base_Type (P_Type);
5939 -- If the root type or base type is generic, then we cannot fold. This
5940 -- test is needed because subtypes of generic types are not always
5941 -- marked as being generic themselves (which seems odd???)
5943 if Is_Generic_Type (P_Root_Type)
5944 or else Is_Generic_Type (P_Base_Type)
5949 if Is_Scalar_Type (P_Type) then
5950 Static := Is_OK_Static_Subtype (P_Type);
5952 -- Array case. We enforce the constrained requirement of (RM 4.9(7-8))
5953 -- since we can't do anything with unconstrained arrays. In addition,
5954 -- only the First, Last and Length attributes are possibly static.
5956 -- Definite, Has_Access_Values, Has_Discriminants, Has_Tagged_Values,
5957 -- Type_Class, and Unconstrained_Array are again exceptions, because
5958 -- they apply as well to unconstrained types.
5960 -- In addition Component_Size is an exception since it is possibly
5961 -- foldable, even though it is never static, and it does apply to
5962 -- unconstrained arrays. Furthermore, it is essential to fold this
5963 -- in the packed case, since otherwise the value will be incorrect.
5965 elsif Id = Attribute_Definite
5967 Id = Attribute_Has_Access_Values
5969 Id = Attribute_Has_Discriminants
5971 Id = Attribute_Has_Tagged_Values
5973 Id = Attribute_Type_Class
5975 Id = Attribute_Unconstrained_Array
5977 Id = Attribute_Component_Size
5981 elsif Id /= Attribute_Max_Alignment_For_Allocation then
5982 if not Is_Constrained (P_Type)
5983 or else (Id /= Attribute_First and then
5984 Id /= Attribute_Last and then
5985 Id /= Attribute_Length)
5991 -- The rules in (RM 4.9(7,8)) require a static array, but as in the
5992 -- scalar case, we hold off on enforcing staticness, since there are
5993 -- cases which we can fold at compile time even though they are not
5994 -- static (e.g. 'Length applied to a static index, even though other
5995 -- non-static indexes make the array type non-static). This is only
5996 -- an optimization, but it falls out essentially free, so why not.
5997 -- Again we compute the variable Static for easy reference later
5998 -- (note that no array attributes are static in Ada 83).
6000 -- We also need to set Static properly for subsequent legality checks
6001 -- which might otherwise accept non-static constants in contexts
6002 -- where they are not legal.
6004 Static := Ada_Version >= Ada_95
6005 and then Statically_Denotes_Entity (P);
6011 N := First_Index (P_Type);
6013 -- The expression is static if the array type is constrained
6014 -- by given bounds, and not by an initial expression. Constant
6015 -- strings are static in any case.
6017 if Root_Type (P_Type) /= Standard_String then
6019 Static and then not Is_Constr_Subt_For_U_Nominal (P_Type);
6022 while Present (N) loop
6023 Static := Static and then Is_Static_Subtype (Etype (N));
6025 -- If however the index type is generic, or derived from
6026 -- one, attributes cannot be folded.
6028 if Is_Generic_Type (Root_Type (Etype (N)))
6029 and then Id /= Attribute_Component_Size
6039 -- Check any expressions that are present. Note that these expressions,
6040 -- depending on the particular attribute type, are either part of the
6041 -- attribute designator, or they are arguments in a case where the
6042 -- attribute reference returns a function. In the latter case, the
6043 -- rule in (RM 4.9(22)) applies and in particular requires the type
6044 -- of the expressions to be scalar in order for the attribute to be
6045 -- considered to be static.
6052 while Present (E) loop
6054 -- If expression is not static, then the attribute reference
6055 -- result certainly cannot be static.
6057 if not Is_Static_Expression (E) then
6061 -- If the result is not known at compile time, or is not of
6062 -- a scalar type, then the result is definitely not static,
6063 -- so we can quit now.
6065 if not Compile_Time_Known_Value (E)
6066 or else not Is_Scalar_Type (Etype (E))
6068 -- An odd special case, if this is a Pos attribute, this
6069 -- is where we need to apply a range check since it does
6070 -- not get done anywhere else.
6072 if Id = Attribute_Pos then
6073 if Is_Integer_Type (Etype (E)) then
6074 Apply_Range_Check (E, Etype (N));
6081 -- If the expression raises a constraint error, then so does
6082 -- the attribute reference. We keep going in this case because
6083 -- we are still interested in whether the attribute reference
6084 -- is static even if it is not static.
6086 elsif Raises_Constraint_Error (E) then
6087 Set_Raises_Constraint_Error (N);
6093 if Raises_Constraint_Error (Prefix (N)) then
6098 -- Deal with the case of a static attribute reference that raises
6099 -- constraint error. The Raises_Constraint_Error flag will already
6100 -- have been set, and the Static flag shows whether the attribute
6101 -- reference is static. In any case we certainly can't fold such an
6102 -- attribute reference.
6104 -- Note that the rewriting of the attribute node with the constraint
6105 -- error node is essential in this case, because otherwise Gigi might
6106 -- blow up on one of the attributes it never expects to see.
6108 -- The constraint_error node must have the type imposed by the context,
6109 -- to avoid spurious errors in the enclosing expression.
6111 if Raises_Constraint_Error (N) then
6113 Make_Raise_Constraint_Error (Sloc (N),
6114 Reason => CE_Range_Check_Failed);
6115 Set_Etype (CE_Node, Etype (N));
6116 Set_Raises_Constraint_Error (CE_Node);
6118 Rewrite (N, Relocate_Node (CE_Node));
6119 Set_Is_Static_Expression (N, Static);
6123 -- At this point we have a potentially foldable attribute reference.
6124 -- If Static is set, then the attribute reference definitely obeys
6125 -- the requirements in (RM 4.9(7,8,22)), and it definitely can be
6126 -- folded. If Static is not set, then the attribute may or may not
6127 -- be foldable, and the individual attribute processing routines
6128 -- test Static as required in cases where it makes a difference.
6130 -- In the case where Static is not set, we do know that all the
6131 -- expressions present are at least known at compile time (we assumed
6132 -- above that if this was not the case, then there was no hope of static
6133 -- evaluation). However, we did not require that the bounds of the
6134 -- prefix type be compile time known, let alone static). That's because
6135 -- there are many attributes that can be computed at compile time on
6136 -- non-static subtypes, even though such references are not static
6141 -- Attributes related to Ada 2012 iterators (placeholder ???)
6143 when Attribute_Constant_Indexing => null;
6144 when Attribute_Default_Iterator => null;
6145 when Attribute_Implicit_Dereference => null;
6146 when Attribute_Iterator_Element => null;
6147 when Attribute_Variable_Indexing => null;
6153 when Attribute_Adjacent =>
6156 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6162 when Attribute_Aft =>
6163 Fold_Uint (N, Aft_Value (P_Type), True);
6169 when Attribute_Alignment => Alignment_Block : declare
6170 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6173 -- Fold if alignment is set and not otherwise
6175 if Known_Alignment (P_TypeA) then
6176 Fold_Uint (N, Alignment (P_TypeA), Is_Discrete_Type (P_TypeA));
6178 end Alignment_Block;
6184 -- Can only be folded in No_Ast_Handler case
6186 when Attribute_AST_Entry =>
6187 if not Is_AST_Entry (P_Entity) then
6189 New_Occurrence_Of (RTE (RE_No_AST_Handler), Loc));
6198 -- Bit can never be folded
6200 when Attribute_Bit =>
6207 -- Body_version can never be static
6209 when Attribute_Body_Version =>
6216 when Attribute_Ceiling =>
6218 Eval_Fat.Ceiling (P_Root_Type, Expr_Value_R (E1)), Static);
6220 --------------------
6221 -- Component_Size --
6222 --------------------
6224 when Attribute_Component_Size =>
6225 if Known_Static_Component_Size (P_Type) then
6226 Fold_Uint (N, Component_Size (P_Type), False);
6233 when Attribute_Compose =>
6236 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)),
6243 -- Constrained is never folded for now, there may be cases that
6244 -- could be handled at compile time. To be looked at later.
6246 when Attribute_Constrained =>
6253 when Attribute_Copy_Sign =>
6256 (P_Root_Type, Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6262 when Attribute_Definite =>
6263 Rewrite (N, New_Occurrence_Of (
6264 Boolean_Literals (not Is_Indefinite_Subtype (P_Entity)), Loc));
6265 Analyze_And_Resolve (N, Standard_Boolean);
6271 when Attribute_Delta =>
6272 Fold_Ureal (N, Delta_Value (P_Type), True);
6278 when Attribute_Denorm =>
6280 (N, UI_From_Int (Boolean'Pos (Denorm_On_Target)), True);
6282 ---------------------
6283 -- Descriptor_Size --
6284 ---------------------
6286 when Attribute_Descriptor_Size =>
6293 when Attribute_Digits =>
6294 Fold_Uint (N, Digits_Value (P_Type), True);
6300 when Attribute_Emax =>
6302 -- Ada 83 attribute is defined as (RM83 3.5.8)
6304 -- T'Emax = 4 * T'Mantissa
6306 Fold_Uint (N, 4 * Mantissa, True);
6312 when Attribute_Enum_Rep =>
6314 -- For an enumeration type with a non-standard representation use
6315 -- the Enumeration_Rep field of the proper constant. Note that this
6316 -- will not work for types Character/Wide_[Wide-]Character, since no
6317 -- real entities are created for the enumeration literals, but that
6318 -- does not matter since these two types do not have non-standard
6319 -- representations anyway.
6321 if Is_Enumeration_Type (P_Type)
6322 and then Has_Non_Standard_Rep (P_Type)
6324 Fold_Uint (N, Enumeration_Rep (Expr_Value_E (E1)), Static);
6326 -- For enumeration types with standard representations and all
6327 -- other cases (i.e. all integer and modular types), Enum_Rep
6328 -- is equivalent to Pos.
6331 Fold_Uint (N, Expr_Value (E1), Static);
6338 when Attribute_Enum_Val => Enum_Val : declare
6342 -- We have something like Enum_Type'Enum_Val (23), so search for a
6343 -- corresponding value in the list of Enum_Rep values for the type.
6345 Lit := First_Literal (P_Base_Type);
6347 if Enumeration_Rep (Lit) = Expr_Value (E1) then
6348 Fold_Uint (N, Enumeration_Pos (Lit), Static);
6355 Apply_Compile_Time_Constraint_Error
6356 (N, "no representation value matches",
6357 CE_Range_Check_Failed,
6358 Warn => not Static);
6368 when Attribute_Epsilon =>
6370 -- Ada 83 attribute is defined as (RM83 3.5.8)
6372 -- T'Epsilon = 2.0**(1 - T'Mantissa)
6374 Fold_Ureal (N, Ureal_2 ** (1 - Mantissa), True);
6380 when Attribute_Exponent =>
6382 Eval_Fat.Exponent (P_Root_Type, Expr_Value_R (E1)), Static);
6388 when Attribute_First => First_Attr :
6392 if Compile_Time_Known_Value (Lo_Bound) then
6393 if Is_Real_Type (P_Type) then
6394 Fold_Ureal (N, Expr_Value_R (Lo_Bound), Static);
6396 Fold_Uint (N, Expr_Value (Lo_Bound), Static);
6399 -- Replace VAX Float_Type'First with a reference to the temporary
6400 -- which represents the low bound of the type. This transformation
6401 -- is needed since the back end cannot evaluate 'First on VAX.
6403 elsif Is_VAX_Float (P_Type)
6404 and then Nkind (Lo_Bound) = N_Identifier
6406 Rewrite (N, New_Reference_To (Entity (Lo_Bound), Sloc (N)));
6410 Check_Concurrent_Discriminant (Lo_Bound);
6418 when Attribute_Fixed_Value =>
6425 when Attribute_Floor =>
6427 Eval_Fat.Floor (P_Root_Type, Expr_Value_R (E1)), Static);
6433 when Attribute_Fore =>
6434 if Compile_Time_Known_Bounds (P_Type) then
6435 Fold_Uint (N, UI_From_Int (Fore_Value), Static);
6442 when Attribute_Fraction =>
6444 Eval_Fat.Fraction (P_Root_Type, Expr_Value_R (E1)), Static);
6446 -----------------------
6447 -- Has_Access_Values --
6448 -----------------------
6450 when Attribute_Has_Access_Values =>
6451 Rewrite (N, New_Occurrence_Of
6452 (Boolean_Literals (Has_Access_Values (P_Root_Type)), Loc));
6453 Analyze_And_Resolve (N, Standard_Boolean);
6455 -----------------------
6456 -- Has_Discriminants --
6457 -----------------------
6459 when Attribute_Has_Discriminants =>
6460 Rewrite (N, New_Occurrence_Of (
6461 Boolean_Literals (Has_Discriminants (P_Entity)), Loc));
6462 Analyze_And_Resolve (N, Standard_Boolean);
6464 -----------------------
6465 -- Has_Tagged_Values --
6466 -----------------------
6468 when Attribute_Has_Tagged_Values =>
6469 Rewrite (N, New_Occurrence_Of
6470 (Boolean_Literals (Has_Tagged_Component (P_Root_Type)), Loc));
6471 Analyze_And_Resolve (N, Standard_Boolean);
6477 when Attribute_Identity =>
6484 -- Image is a scalar attribute, but is never static, because it is
6485 -- not a static function (having a non-scalar argument (RM 4.9(22))
6486 -- However, we can constant-fold the image of an enumeration literal
6487 -- if names are available.
6489 when Attribute_Image =>
6490 if Is_Entity_Name (E1)
6491 and then Ekind (Entity (E1)) = E_Enumeration_Literal
6492 and then not Discard_Names (First_Subtype (Etype (E1)))
6493 and then not Global_Discard_Names
6496 Lit : constant Entity_Id := Entity (E1);
6500 Get_Unqualified_Decoded_Name_String (Chars (Lit));
6501 Set_Casing (All_Upper_Case);
6502 Store_String_Chars (Name_Buffer (1 .. Name_Len));
6504 Rewrite (N, Make_String_Literal (Loc, Strval => Str));
6505 Analyze_And_Resolve (N, Standard_String);
6506 Set_Is_Static_Expression (N, False);
6514 -- Img is a scalar attribute, but is never static, because it is
6515 -- not a static function (having a non-scalar argument (RM 4.9(22))
6517 when Attribute_Img =>
6524 -- We never try to fold Integer_Value (though perhaps we could???)
6526 when Attribute_Integer_Value =>
6533 -- Invalid_Value is a scalar attribute that is never static, because
6534 -- the value is by design out of range.
6536 when Attribute_Invalid_Value =>
6543 when Attribute_Large =>
6545 -- For fixed-point, we use the identity:
6547 -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small
6549 if Is_Fixed_Point_Type (P_Type) then
6551 Make_Op_Multiply (Loc,
6553 Make_Op_Subtract (Loc,
6557 Make_Real_Literal (Loc, Ureal_2),
6559 Make_Attribute_Reference (Loc,
6561 Attribute_Name => Name_Mantissa)),
6562 Right_Opnd => Make_Real_Literal (Loc, Ureal_1)),
6565 Make_Real_Literal (Loc, Small_Value (Entity (P)))));
6567 Analyze_And_Resolve (N, C_Type);
6569 -- Floating-point (Ada 83 compatibility)
6572 -- Ada 83 attribute is defined as (RM83 3.5.8)
6574 -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa))
6578 -- T'Emax = 4 * T'Mantissa
6581 Ureal_2 ** (4 * Mantissa) * (Ureal_1 - Ureal_2 ** (-Mantissa)),
6589 when Attribute_Last => Last :
6593 if Compile_Time_Known_Value (Hi_Bound) then
6594 if Is_Real_Type (P_Type) then
6595 Fold_Ureal (N, Expr_Value_R (Hi_Bound), Static);
6597 Fold_Uint (N, Expr_Value (Hi_Bound), Static);
6600 -- Replace VAX Float_Type'Last with a reference to the temporary
6601 -- which represents the high bound of the type. This transformation
6602 -- is needed since the back end cannot evaluate 'Last on VAX.
6604 elsif Is_VAX_Float (P_Type)
6605 and then Nkind (Hi_Bound) = N_Identifier
6607 Rewrite (N, New_Reference_To (Entity (Hi_Bound), Sloc (N)));
6611 Check_Concurrent_Discriminant (Hi_Bound);
6619 when Attribute_Leading_Part =>
6621 Eval_Fat.Leading_Part
6622 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
6628 when Attribute_Length => Length : declare
6632 -- If any index type is a formal type, or derived from one, the
6633 -- bounds are not static. Treating them as static can produce
6634 -- spurious warnings or improper constant folding.
6636 Ind := First_Index (P_Type);
6637 while Present (Ind) loop
6638 if Is_Generic_Type (Root_Type (Etype (Ind))) then
6647 -- For two compile time values, we can compute length
6649 if Compile_Time_Known_Value (Lo_Bound)
6650 and then Compile_Time_Known_Value (Hi_Bound)
6653 UI_Max (0, 1 + (Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound))),
6657 -- One more case is where Hi_Bound and Lo_Bound are compile-time
6658 -- comparable, and we can figure out the difference between them.
6661 Diff : aliased Uint;
6665 Compile_Time_Compare
6666 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
6669 Fold_Uint (N, Uint_1, False);
6672 Fold_Uint (N, Uint_0, False);
6675 if Diff /= No_Uint then
6676 Fold_Uint (N, Diff + 1, False);
6689 when Attribute_Machine =>
6692 (P_Root_Type, Expr_Value_R (E1), Eval_Fat.Round, N),
6699 when Attribute_Machine_Emax =>
6700 Fold_Uint (N, Machine_Emax_Value (P_Type), Static);
6706 when Attribute_Machine_Emin =>
6707 Fold_Uint (N, Machine_Emin_Value (P_Type), Static);
6709 ----------------------
6710 -- Machine_Mantissa --
6711 ----------------------
6713 when Attribute_Machine_Mantissa =>
6714 Fold_Uint (N, Machine_Mantissa_Value (P_Type), Static);
6716 -----------------------
6717 -- Machine_Overflows --
6718 -----------------------
6720 when Attribute_Machine_Overflows =>
6722 -- Always true for fixed-point
6724 if Is_Fixed_Point_Type (P_Type) then
6725 Fold_Uint (N, True_Value, True);
6727 -- Floating point case
6731 UI_From_Int (Boolean'Pos (Machine_Overflows_On_Target)),
6739 when Attribute_Machine_Radix =>
6740 if Is_Fixed_Point_Type (P_Type) then
6741 if Is_Decimal_Fixed_Point_Type (P_Type)
6742 and then Machine_Radix_10 (P_Type)
6744 Fold_Uint (N, Uint_10, True);
6746 Fold_Uint (N, Uint_2, True);
6749 -- All floating-point type always have radix 2
6752 Fold_Uint (N, Uint_2, True);
6755 ----------------------
6756 -- Machine_Rounding --
6757 ----------------------
6759 -- Note: for the folding case, it is fine to treat Machine_Rounding
6760 -- exactly the same way as Rounding, since this is one of the allowed
6761 -- behaviors, and performance is not an issue here. It might be a bit
6762 -- better to give the same result as it would give at run time, even
6763 -- though the non-determinism is certainly permitted.
6765 when Attribute_Machine_Rounding =>
6767 Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static);
6769 --------------------
6770 -- Machine_Rounds --
6771 --------------------
6773 when Attribute_Machine_Rounds =>
6775 -- Always False for fixed-point
6777 if Is_Fixed_Point_Type (P_Type) then
6778 Fold_Uint (N, False_Value, True);
6780 -- Else yield proper floating-point result
6784 (N, UI_From_Int (Boolean'Pos (Machine_Rounds_On_Target)), True);
6791 -- Note: Machine_Size is identical to Object_Size
6793 when Attribute_Machine_Size => Machine_Size : declare
6794 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
6797 if Known_Esize (P_TypeA) then
6798 Fold_Uint (N, Esize (P_TypeA), True);
6806 when Attribute_Mantissa =>
6808 -- Fixed-point mantissa
6810 if Is_Fixed_Point_Type (P_Type) then
6812 -- Compile time foldable case
6814 if Compile_Time_Known_Value (Type_Low_Bound (P_Type))
6816 Compile_Time_Known_Value (Type_High_Bound (P_Type))
6818 -- The calculation of the obsolete Ada 83 attribute Mantissa
6819 -- is annoying, because of AI00143, quoted here:
6821 -- !question 84-01-10
6823 -- Consider the model numbers for F:
6825 -- type F is delta 1.0 range -7.0 .. 8.0;
6827 -- The wording requires that F'MANTISSA be the SMALLEST
6828 -- integer number for which each bound of the specified
6829 -- range is either a model number or lies at most small
6830 -- distant from a model number. This means F'MANTISSA
6831 -- is required to be 3 since the range -7.0 .. 7.0 fits
6832 -- in 3 signed bits, and 8 is "at most" 1.0 from a model
6833 -- number, namely, 7. Is this analysis correct? Note that
6834 -- this implies the upper bound of the range is not
6835 -- represented as a model number.
6837 -- !response 84-03-17
6839 -- The analysis is correct. The upper and lower bounds for
6840 -- a fixed point type can lie outside the range of model
6851 LBound := Expr_Value_R (Type_Low_Bound (P_Type));
6852 UBound := Expr_Value_R (Type_High_Bound (P_Type));
6853 Bound := UR_Max (UR_Abs (LBound), UR_Abs (UBound));
6854 Max_Man := UR_Trunc (Bound / Small_Value (P_Type));
6856 -- If the Bound is exactly a model number, i.e. a multiple
6857 -- of Small, then we back it off by one to get the integer
6858 -- value that must be representable.
6860 if Small_Value (P_Type) * Max_Man = Bound then
6861 Max_Man := Max_Man - 1;
6864 -- Now find corresponding size = Mantissa value
6867 while 2 ** Siz < Max_Man loop
6871 Fold_Uint (N, Siz, True);
6875 -- The case of dynamic bounds cannot be evaluated at compile
6876 -- time. Instead we use a runtime routine (see Exp_Attr).
6881 -- Floating-point Mantissa
6884 Fold_Uint (N, Mantissa, True);
6891 when Attribute_Max => Max :
6893 if Is_Real_Type (P_Type) then
6895 (N, UR_Max (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6897 Fold_Uint (N, UI_Max (Expr_Value (E1), Expr_Value (E2)), Static);
6901 ----------------------------------
6902 -- Max_Alignment_For_Allocation --
6903 ----------------------------------
6905 -- Max_Alignment_For_Allocation is usually the Alignment. However,
6906 -- arrays are allocated with dope, so we need to take into account both
6907 -- the alignment of the array, which comes from the component alignment,
6908 -- and the alignment of the dope. Also, if the alignment is unknown, we
6909 -- use the max (it's OK to be pessimistic).
6911 when Attribute_Max_Alignment_For_Allocation =>
6913 A : Uint := UI_From_Int (Ttypes.Maximum_Alignment);
6915 if Known_Alignment (P_Type) and then
6916 (not Is_Array_Type (P_Type) or else Alignment (P_Type) > A)
6918 A := Alignment (P_Type);
6921 Fold_Uint (N, A, Static);
6924 ----------------------------------
6925 -- Max_Size_In_Storage_Elements --
6926 ----------------------------------
6928 -- Max_Size_In_Storage_Elements is simply the Size rounded up to a
6929 -- Storage_Unit boundary. We can fold any cases for which the size
6930 -- is known by the front end.
6932 when Attribute_Max_Size_In_Storage_Elements =>
6933 if Known_Esize (P_Type) then
6935 (Esize (P_Type) + System_Storage_Unit - 1) /
6936 System_Storage_Unit,
6940 --------------------
6941 -- Mechanism_Code --
6942 --------------------
6944 when Attribute_Mechanism_Code =>
6948 Mech : Mechanism_Type;
6952 Mech := Mechanism (P_Entity);
6955 Val := UI_To_Int (Expr_Value (E1));
6957 Formal := First_Formal (P_Entity);
6958 for J in 1 .. Val - 1 loop
6959 Next_Formal (Formal);
6961 Mech := Mechanism (Formal);
6965 Fold_Uint (N, UI_From_Int (Int (-Mech)), True);
6973 when Attribute_Min => Min :
6975 if Is_Real_Type (P_Type) then
6977 (N, UR_Min (Expr_Value_R (E1), Expr_Value_R (E2)), Static);
6980 (N, UI_Min (Expr_Value (E1), Expr_Value (E2)), Static);
6988 when Attribute_Mod =>
6990 (N, UI_Mod (Expr_Value (E1), Modulus (P_Base_Type)), Static);
6996 when Attribute_Model =>
6998 Eval_Fat.Model (P_Root_Type, Expr_Value_R (E1)), Static);
7004 when Attribute_Model_Emin =>
7005 Fold_Uint (N, Model_Emin_Value (P_Base_Type), Static);
7011 when Attribute_Model_Epsilon =>
7012 Fold_Ureal (N, Model_Epsilon_Value (P_Base_Type), Static);
7014 --------------------
7015 -- Model_Mantissa --
7016 --------------------
7018 when Attribute_Model_Mantissa =>
7019 Fold_Uint (N, Model_Mantissa_Value (P_Base_Type), Static);
7025 when Attribute_Model_Small =>
7026 Fold_Ureal (N, Model_Small_Value (P_Base_Type), Static);
7032 when Attribute_Modulus =>
7033 Fold_Uint (N, Modulus (P_Type), True);
7035 --------------------
7036 -- Null_Parameter --
7037 --------------------
7039 -- Cannot fold, we know the value sort of, but the whole point is
7040 -- that there is no way to talk about this imaginary value except
7041 -- by using the attribute, so we leave it the way it is.
7043 when Attribute_Null_Parameter =>
7050 -- The Object_Size attribute for a type returns the Esize of the
7051 -- type and can be folded if this value is known.
7053 when Attribute_Object_Size => Object_Size : declare
7054 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
7057 if Known_Esize (P_TypeA) then
7058 Fold_Uint (N, Esize (P_TypeA), True);
7062 ----------------------
7063 -- Overlaps_Storage --
7064 ----------------------
7066 when Attribute_Overlaps_Storage =>
7069 -------------------------
7070 -- Passed_By_Reference --
7071 -------------------------
7073 -- Scalar types are never passed by reference
7075 when Attribute_Passed_By_Reference =>
7076 Fold_Uint (N, False_Value, True);
7082 when Attribute_Pos =>
7083 Fold_Uint (N, Expr_Value (E1), True);
7089 when Attribute_Pred => Pred :
7091 -- Floating-point case
7093 if Is_Floating_Point_Type (P_Type) then
7095 Eval_Fat.Pred (P_Root_Type, Expr_Value_R (E1)), Static);
7099 elsif Is_Fixed_Point_Type (P_Type) then
7101 Expr_Value_R (E1) - Small_Value (P_Type), True);
7103 -- Modular integer case (wraps)
7105 elsif Is_Modular_Integer_Type (P_Type) then
7106 Fold_Uint (N, (Expr_Value (E1) - 1) mod Modulus (P_Type), Static);
7108 -- Other scalar cases
7111 pragma Assert (Is_Scalar_Type (P_Type));
7113 if Is_Enumeration_Type (P_Type)
7114 and then Expr_Value (E1) =
7115 Expr_Value (Type_Low_Bound (P_Base_Type))
7117 Apply_Compile_Time_Constraint_Error
7118 (N, "Pred of `&''First`",
7119 CE_Overflow_Check_Failed,
7121 Warn => not Static);
7127 Fold_Uint (N, Expr_Value (E1) - 1, Static);
7135 -- No processing required, because by this stage, Range has been
7136 -- replaced by First .. Last, so this branch can never be taken.
7138 when Attribute_Range =>
7139 raise Program_Error;
7145 when Attribute_Range_Length =>
7148 -- Can fold if both bounds are compile time known
7150 if Compile_Time_Known_Value (Hi_Bound)
7151 and then Compile_Time_Known_Value (Lo_Bound)
7155 (0, Expr_Value (Hi_Bound) - Expr_Value (Lo_Bound) + 1),
7159 -- One more case is where Hi_Bound and Lo_Bound are compile-time
7160 -- comparable, and we can figure out the difference between them.
7163 Diff : aliased Uint;
7167 Compile_Time_Compare
7168 (Lo_Bound, Hi_Bound, Diff'Access, Assume_Valid => False)
7171 Fold_Uint (N, Uint_1, False);
7174 Fold_Uint (N, Uint_0, False);
7177 if Diff /= No_Uint then
7178 Fold_Uint (N, Diff + 1, False);
7190 when Attribute_Ref =>
7191 Fold_Uint (N, Expr_Value (E1), True);
7197 when Attribute_Remainder => Remainder : declare
7198 X : constant Ureal := Expr_Value_R (E1);
7199 Y : constant Ureal := Expr_Value_R (E2);
7202 if UR_Is_Zero (Y) then
7203 Apply_Compile_Time_Constraint_Error
7204 (N, "division by zero in Remainder",
7205 CE_Overflow_Check_Failed,
7206 Warn => not Static);
7212 Fold_Ureal (N, Eval_Fat.Remainder (P_Root_Type, X, Y), Static);
7219 when Attribute_Round => Round :
7225 -- First we get the (exact result) in units of small
7227 Sr := Expr_Value_R (E1) / Small_Value (C_Type);
7229 -- Now round that exactly to an integer
7231 Si := UR_To_Uint (Sr);
7233 -- Finally the result is obtained by converting back to real
7235 Fold_Ureal (N, Si * Small_Value (C_Type), Static);
7242 when Attribute_Rounding =>
7244 Eval_Fat.Rounding (P_Root_Type, Expr_Value_R (E1)), Static);
7250 when Attribute_Safe_Emax =>
7251 Fold_Uint (N, Safe_Emax_Value (P_Type), Static);
7257 when Attribute_Safe_First =>
7258 Fold_Ureal (N, Safe_First_Value (P_Type), Static);
7264 when Attribute_Safe_Large =>
7265 if Is_Fixed_Point_Type (P_Type) then
7267 (N, Expr_Value_R (Type_High_Bound (P_Base_Type)), Static);
7269 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
7276 when Attribute_Safe_Last =>
7277 Fold_Ureal (N, Safe_Last_Value (P_Type), Static);
7283 when Attribute_Safe_Small =>
7285 -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant
7286 -- for fixed-point, since is the same as Small, but we implement
7287 -- it for backwards compatibility.
7289 if Is_Fixed_Point_Type (P_Type) then
7290 Fold_Ureal (N, Small_Value (P_Type), Static);
7292 -- Ada 83 Safe_Small for floating-point cases
7295 Fold_Ureal (N, Model_Small_Value (P_Type), Static);
7302 when Attribute_Same_Storage =>
7309 when Attribute_Scale =>
7310 Fold_Uint (N, Scale_Value (P_Type), True);
7316 when Attribute_Scaling =>
7319 (P_Root_Type, Expr_Value_R (E1), Expr_Value (E2)), Static);
7325 when Attribute_Signed_Zeros =>
7327 (N, UI_From_Int (Boolean'Pos (Signed_Zeros_On_Target)), Static);
7333 -- Size attribute returns the RM size. All scalar types can be folded,
7334 -- as well as any types for which the size is known by the front end,
7335 -- including any type for which a size attribute is specified.
7337 when Attribute_Size | Attribute_VADS_Size => Size : declare
7338 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
7341 if RM_Size (P_TypeA) /= Uint_0 then
7345 if Id = Attribute_VADS_Size or else Use_VADS_Size then
7347 S : constant Node_Id := Size_Clause (P_TypeA);
7350 -- If a size clause applies, then use the size from it.
7351 -- This is one of the rare cases where we can use the
7352 -- Size_Clause field for a subtype when Has_Size_Clause
7353 -- is False. Consider:
7355 -- type x is range 1 .. 64;
7356 -- for x'size use 12;
7357 -- subtype y is x range 0 .. 3;
7359 -- Here y has a size clause inherited from x, but normally
7360 -- it does not apply, and y'size is 2. However, y'VADS_Size
7361 -- is indeed 12 and not 2.
7364 and then Is_OK_Static_Expression (Expression (S))
7366 Fold_Uint (N, Expr_Value (Expression (S)), True);
7368 -- If no size is specified, then we simply use the object
7369 -- size in the VADS_Size case (e.g. Natural'Size is equal
7370 -- to Integer'Size, not one less).
7373 Fold_Uint (N, Esize (P_TypeA), True);
7377 -- Normal case (Size) in which case we want the RM_Size
7382 Static and then Is_Discrete_Type (P_TypeA));
7391 when Attribute_Small =>
7393 -- The floating-point case is present only for Ada 83 compatibility.
7394 -- Note that strictly this is an illegal addition, since we are
7395 -- extending an Ada 95 defined attribute, but we anticipate an
7396 -- ARG ruling that will permit this.
7398 if Is_Floating_Point_Type (P_Type) then
7400 -- Ada 83 attribute is defined as (RM83 3.5.8)
7402 -- T'Small = 2.0**(-T'Emax - 1)
7406 -- T'Emax = 4 * T'Mantissa
7408 Fold_Ureal (N, Ureal_2 ** ((-(4 * Mantissa)) - 1), Static);
7410 -- Normal Ada 95 fixed-point case
7413 Fold_Ureal (N, Small_Value (P_Type), True);
7420 when Attribute_Stream_Size =>
7427 when Attribute_Succ => Succ :
7429 -- Floating-point case
7431 if Is_Floating_Point_Type (P_Type) then
7433 Eval_Fat.Succ (P_Root_Type, Expr_Value_R (E1)), Static);
7437 elsif Is_Fixed_Point_Type (P_Type) then
7439 Expr_Value_R (E1) + Small_Value (P_Type), Static);
7441 -- Modular integer case (wraps)
7443 elsif Is_Modular_Integer_Type (P_Type) then
7444 Fold_Uint (N, (Expr_Value (E1) + 1) mod Modulus (P_Type), Static);
7446 -- Other scalar cases
7449 pragma Assert (Is_Scalar_Type (P_Type));
7451 if Is_Enumeration_Type (P_Type)
7452 and then Expr_Value (E1) =
7453 Expr_Value (Type_High_Bound (P_Base_Type))
7455 Apply_Compile_Time_Constraint_Error
7456 (N, "Succ of `&''Last`",
7457 CE_Overflow_Check_Failed,
7459 Warn => not Static);
7464 Fold_Uint (N, Expr_Value (E1) + 1, Static);
7473 when Attribute_Truncation =>
7475 Eval_Fat.Truncation (P_Root_Type, Expr_Value_R (E1)), Static);
7481 when Attribute_Type_Class => Type_Class : declare
7482 Typ : constant Entity_Id := Underlying_Type (P_Base_Type);
7486 if Is_Descendent_Of_Address (Typ) then
7487 Id := RE_Type_Class_Address;
7489 elsif Is_Enumeration_Type (Typ) then
7490 Id := RE_Type_Class_Enumeration;
7492 elsif Is_Integer_Type (Typ) then
7493 Id := RE_Type_Class_Integer;
7495 elsif Is_Fixed_Point_Type (Typ) then
7496 Id := RE_Type_Class_Fixed_Point;
7498 elsif Is_Floating_Point_Type (Typ) then
7499 Id := RE_Type_Class_Floating_Point;
7501 elsif Is_Array_Type (Typ) then
7502 Id := RE_Type_Class_Array;
7504 elsif Is_Record_Type (Typ) then
7505 Id := RE_Type_Class_Record;
7507 elsif Is_Access_Type (Typ) then
7508 Id := RE_Type_Class_Access;
7510 elsif Is_Enumeration_Type (Typ) then
7511 Id := RE_Type_Class_Enumeration;
7513 elsif Is_Task_Type (Typ) then
7514 Id := RE_Type_Class_Task;
7516 -- We treat protected types like task types. It would make more
7517 -- sense to have another enumeration value, but after all the
7518 -- whole point of this feature is to be exactly DEC compatible,
7519 -- and changing the type Type_Class would not meet this requirement.
7521 elsif Is_Protected_Type (Typ) then
7522 Id := RE_Type_Class_Task;
7524 -- Not clear if there are any other possibilities, but if there
7525 -- are, then we will treat them as the address case.
7528 Id := RE_Type_Class_Address;
7531 Rewrite (N, New_Occurrence_Of (RTE (Id), Loc));
7534 -----------------------
7535 -- Unbiased_Rounding --
7536 -----------------------
7538 when Attribute_Unbiased_Rounding =>
7540 Eval_Fat.Unbiased_Rounding (P_Root_Type, Expr_Value_R (E1)),
7543 -------------------------
7544 -- Unconstrained_Array --
7545 -------------------------
7547 when Attribute_Unconstrained_Array => Unconstrained_Array : declare
7548 Typ : constant Entity_Id := Underlying_Type (P_Type);
7551 Rewrite (N, New_Occurrence_Of (
7553 Is_Array_Type (P_Type)
7554 and then not Is_Constrained (Typ)), Loc));
7556 -- Analyze and resolve as boolean, note that this attribute is
7557 -- a static attribute in GNAT.
7559 Analyze_And_Resolve (N, Standard_Boolean);
7561 end Unconstrained_Array;
7567 -- Processing is shared with Size
7573 when Attribute_Val => Val :
7575 if Expr_Value (E1) < Expr_Value (Type_Low_Bound (P_Base_Type))
7577 Expr_Value (E1) > Expr_Value (Type_High_Bound (P_Base_Type))
7579 Apply_Compile_Time_Constraint_Error
7580 (N, "Val expression out of range",
7581 CE_Range_Check_Failed,
7582 Warn => not Static);
7588 Fold_Uint (N, Expr_Value (E1), Static);
7596 -- The Value_Size attribute for a type returns the RM size of the
7597 -- type. This an always be folded for scalar types, and can also
7598 -- be folded for non-scalar types if the size is set.
7600 when Attribute_Value_Size => Value_Size : declare
7601 P_TypeA : constant Entity_Id := Underlying_Type (P_Type);
7603 if RM_Size (P_TypeA) /= Uint_0 then
7604 Fold_Uint (N, RM_Size (P_TypeA), True);
7612 -- Version can never be static
7614 when Attribute_Version =>
7621 -- Wide_Image is a scalar attribute, but is never static, because it
7622 -- is not a static function (having a non-scalar argument (RM 4.9(22))
7624 when Attribute_Wide_Image =>
7627 ---------------------
7628 -- Wide_Wide_Image --
7629 ---------------------
7631 -- Wide_Wide_Image is a scalar attribute but is never static, because it
7632 -- is not a static function (having a non-scalar argument (RM 4.9(22)).
7634 when Attribute_Wide_Wide_Image =>
7637 ---------------------
7638 -- Wide_Wide_Width --
7639 ---------------------
7641 -- Processing for Wide_Wide_Width is combined with Width
7647 -- Processing for Wide_Width is combined with Width
7653 -- This processing also handles the case of Wide_[Wide_]Width
7655 when Attribute_Width |
7656 Attribute_Wide_Width |
7657 Attribute_Wide_Wide_Width => Width :
7659 if Compile_Time_Known_Bounds (P_Type) then
7661 -- Floating-point types
7663 if Is_Floating_Point_Type (P_Type) then
7665 -- Width is zero for a null range (RM 3.5 (38))
7667 if Expr_Value_R (Type_High_Bound (P_Type)) <
7668 Expr_Value_R (Type_Low_Bound (P_Type))
7670 Fold_Uint (N, Uint_0, True);
7673 -- For floating-point, we have +N.dddE+nnn where length
7674 -- of ddd is determined by type'Digits - 1, but is one
7675 -- if Digits is one (RM 3.5 (33)).
7677 -- nnn is set to 2 for Short_Float and Float (32 bit
7678 -- floats), and 3 for Long_Float and Long_Long_Float.
7679 -- For machines where Long_Long_Float is the IEEE
7680 -- extended precision type, the exponent takes 4 digits.
7684 Int'Max (2, UI_To_Int (Digits_Value (P_Type)));
7687 if Esize (P_Type) <= 32 then
7689 elsif Esize (P_Type) = 64 then
7695 Fold_Uint (N, UI_From_Int (Len), True);
7699 -- Fixed-point types
7701 elsif Is_Fixed_Point_Type (P_Type) then
7703 -- Width is zero for a null range (RM 3.5 (38))
7705 if Expr_Value (Type_High_Bound (P_Type)) <
7706 Expr_Value (Type_Low_Bound (P_Type))
7708 Fold_Uint (N, Uint_0, True);
7710 -- The non-null case depends on the specific real type
7713 -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34))
7716 (N, UI_From_Int (Fore_Value + 1) + Aft_Value (P_Type),
7724 R : constant Entity_Id := Root_Type (P_Type);
7725 Lo : constant Uint := Expr_Value (Type_Low_Bound (P_Type));
7726 Hi : constant Uint := Expr_Value (Type_High_Bound (P_Type));
7739 -- Width for types derived from Standard.Character
7740 -- and Standard.Wide_[Wide_]Character.
7742 elsif Is_Standard_Character_Type (P_Type) then
7745 -- Set W larger if needed
7747 for J in UI_To_Int (Lo) .. UI_To_Int (Hi) loop
7749 -- All wide characters look like Hex_hhhhhhhh
7753 -- No need to compute this more than once!
7758 C := Character'Val (J);
7760 -- Test for all cases where Character'Image
7761 -- yields an image that is longer than three
7762 -- characters. First the cases of Reserved_xxx
7763 -- names (length = 12).
7766 when Reserved_128 | Reserved_129 |
7767 Reserved_132 | Reserved_153
7770 when BS | HT | LF | VT | FF | CR |
7771 SO | SI | EM | FS | GS | RS |
7772 US | RI | MW | ST | PM
7775 when NUL | SOH | STX | ETX | EOT |
7776 ENQ | ACK | BEL | DLE | DC1 |
7777 DC2 | DC3 | DC4 | NAK | SYN |
7778 ETB | CAN | SUB | ESC | DEL |
7779 BPH | NBH | NEL | SSA | ESA |
7780 HTS | HTJ | VTS | PLD | PLU |
7781 SS2 | SS3 | DCS | PU1 | PU2 |
7782 STS | CCH | SPA | EPA | SOS |
7783 SCI | CSI | OSC | APC
7786 when Space .. Tilde |
7787 No_Break_Space .. LC_Y_Diaeresis
7789 -- Special case of soft hyphen in Ada 2005
7791 if C = Character'Val (16#AD#)
7792 and then Ada_Version >= Ada_2005
7800 W := Int'Max (W, Wt);
7804 -- Width for types derived from Standard.Boolean
7806 elsif R = Standard_Boolean then
7813 -- Width for integer types
7815 elsif Is_Integer_Type (P_Type) then
7816 T := UI_Max (abs Lo, abs Hi);
7824 -- User declared enum type with discard names
7826 elsif Discard_Names (R) then
7828 -- If range is null, result is zero, that has already
7829 -- been dealt with, so what we need is the power of ten
7830 -- that accomodates the Pos of the largest value, which
7831 -- is the high bound of the range + one for the space.
7840 -- Only remaining possibility is user declared enum type
7841 -- with normal case of Discard_Names not active.
7844 pragma Assert (Is_Enumeration_Type (P_Type));
7847 L := First_Literal (P_Type);
7848 while Present (L) loop
7850 -- Only pay attention to in range characters
7852 if Lo <= Enumeration_Pos (L)
7853 and then Enumeration_Pos (L) <= Hi
7855 -- For Width case, use decoded name
7857 if Id = Attribute_Width then
7858 Get_Decoded_Name_String (Chars (L));
7859 Wt := Nat (Name_Len);
7861 -- For Wide_[Wide_]Width, use encoded name, and
7862 -- then adjust for the encoding.
7865 Get_Name_String (Chars (L));
7867 -- Character literals are always of length 3
7869 if Name_Buffer (1) = 'Q' then
7872 -- Otherwise loop to adjust for upper/wide chars
7875 Wt := Nat (Name_Len);
7877 for J in 1 .. Name_Len loop
7878 if Name_Buffer (J) = 'U' then
7880 elsif Name_Buffer (J) = 'W' then
7887 W := Int'Max (W, Wt);
7894 Fold_Uint (N, UI_From_Int (W), True);
7900 -- The following attributes denote functions that cannot be folded
7902 when Attribute_From_Any |
7904 Attribute_TypeCode =>
7907 -- The following attributes can never be folded, and furthermore we
7908 -- should not even have entered the case statement for any of these.
7909 -- Note that in some cases, the values have already been folded as
7910 -- a result of the processing in Analyze_Attribute.
7912 when Attribute_Abort_Signal |
7915 Attribute_Address_Size |
7916 Attribute_Asm_Input |
7917 Attribute_Asm_Output |
7919 Attribute_Bit_Order |
7920 Attribute_Bit_Position |
7921 Attribute_Callable |
7924 Attribute_Code_Address |
7925 Attribute_Compiler_Version |
7927 Attribute_Default_Bit_Order |
7928 Attribute_Elaborated |
7929 Attribute_Elab_Body |
7930 Attribute_Elab_Spec |
7931 Attribute_Elab_Subp_Body |
7933 Attribute_External_Tag |
7934 Attribute_Fast_Math |
7935 Attribute_First_Bit |
7937 Attribute_Last_Bit |
7938 Attribute_Maximum_Alignment |
7941 Attribute_Partition_ID |
7942 Attribute_Pool_Address |
7943 Attribute_Position |
7944 Attribute_Priority |
7947 Attribute_Storage_Pool |
7948 Attribute_Storage_Size |
7949 Attribute_Storage_Unit |
7950 Attribute_Stub_Type |
7951 Attribute_System_Allocator_Alignment |
7953 Attribute_Target_Name |
7954 Attribute_Terminated |
7955 Attribute_To_Address |
7956 Attribute_Type_Key |
7957 Attribute_UET_Address |
7958 Attribute_Unchecked_Access |
7959 Attribute_Universal_Literal_String |
7960 Attribute_Unrestricted_Access |
7963 Attribute_Wchar_T_Size |
7964 Attribute_Wide_Value |
7965 Attribute_Wide_Wide_Value |
7966 Attribute_Word_Size |
7969 raise Program_Error;
7972 -- At the end of the case, one more check. If we did a static evaluation
7973 -- so that the result is now a literal, then set Is_Static_Expression
7974 -- in the constant only if the prefix type is a static subtype. For
7975 -- non-static subtypes, the folding is still OK, but not static.
7977 -- An exception is the GNAT attribute Constrained_Array which is
7978 -- defined to be a static attribute in all cases.
7980 if Nkind_In (N, N_Integer_Literal,
7982 N_Character_Literal,
7984 or else (Is_Entity_Name (N)
7985 and then Ekind (Entity (N)) = E_Enumeration_Literal)
7987 Set_Is_Static_Expression (N, Static);
7989 -- If this is still an attribute reference, then it has not been folded
7990 -- and that means that its expressions are in a non-static context.
7992 elsif Nkind (N) = N_Attribute_Reference then
7995 -- Note: the else case not covered here are odd cases where the
7996 -- processing has transformed the attribute into something other
7997 -- than a constant. Nothing more to do in such cases.
8004 ------------------------------
8005 -- Is_Anonymous_Tagged_Base --
8006 ------------------------------
8008 function Is_Anonymous_Tagged_Base
8015 Anon = Current_Scope
8016 and then Is_Itype (Anon)
8017 and then Associated_Node_For_Itype (Anon) = Parent (Typ);
8018 end Is_Anonymous_Tagged_Base;
8020 --------------------------------
8021 -- Name_Implies_Lvalue_Prefix --
8022 --------------------------------
8024 function Name_Implies_Lvalue_Prefix (Nam : Name_Id) return Boolean is
8025 pragma Assert (Is_Attribute_Name (Nam));
8027 return Attribute_Name_Implies_Lvalue_Prefix (Get_Attribute_Id (Nam));
8028 end Name_Implies_Lvalue_Prefix;
8030 -----------------------
8031 -- Resolve_Attribute --
8032 -----------------------
8034 procedure Resolve_Attribute (N : Node_Id; Typ : Entity_Id) is
8035 Loc : constant Source_Ptr := Sloc (N);
8036 P : constant Node_Id := Prefix (N);
8037 Aname : constant Name_Id := Attribute_Name (N);
8038 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
8039 Btyp : constant Entity_Id := Base_Type (Typ);
8040 Des_Btyp : Entity_Id;
8041 Index : Interp_Index;
8043 Nom_Subt : Entity_Id;
8045 procedure Accessibility_Message;
8046 -- Error, or warning within an instance, if the static accessibility
8047 -- rules of 3.10.2 are violated.
8049 ---------------------------
8050 -- Accessibility_Message --
8051 ---------------------------
8053 procedure Accessibility_Message is
8054 Indic : Node_Id := Parent (Parent (N));
8057 -- In an instance, this is a runtime check, but one we
8058 -- know will fail, so generate an appropriate warning.
8060 if In_Instance_Body then
8061 Error_Msg_F ("?non-local pointer cannot point to local object", P);
8063 ("\?Program_Error will be raised at run time", P);
8065 Make_Raise_Program_Error (Loc,
8066 Reason => PE_Accessibility_Check_Failed));
8071 Error_Msg_F ("non-local pointer cannot point to local object", P);
8073 -- Check for case where we have a missing access definition
8075 if Is_Record_Type (Current_Scope)
8077 Nkind_In (Parent (N), N_Discriminant_Association,
8078 N_Index_Or_Discriminant_Constraint)
8080 Indic := Parent (Parent (N));
8081 while Present (Indic)
8082 and then Nkind (Indic) /= N_Subtype_Indication
8084 Indic := Parent (Indic);
8087 if Present (Indic) then
8089 ("\use an access definition for" &
8090 " the access discriminant of&",
8091 N, Entity (Subtype_Mark (Indic)));
8095 end Accessibility_Message;
8097 -- Start of processing for Resolve_Attribute
8100 -- If error during analysis, no point in continuing, except for array
8101 -- types, where we get better recovery by using unconstrained indexes
8102 -- than nothing at all (see Check_Array_Type).
8105 and then Attr_Id /= Attribute_First
8106 and then Attr_Id /= Attribute_Last
8107 and then Attr_Id /= Attribute_Length
8108 and then Attr_Id /= Attribute_Range
8113 -- If attribute was universal type, reset to actual type
8115 if Etype (N) = Universal_Integer
8116 or else Etype (N) = Universal_Real
8121 -- Remaining processing depends on attribute
8129 -- For access attributes, if the prefix denotes an entity, it is
8130 -- interpreted as a name, never as a call. It may be overloaded,
8131 -- in which case resolution uses the profile of the context type.
8132 -- Otherwise prefix must be resolved.
8134 when Attribute_Access
8135 | Attribute_Unchecked_Access
8136 | Attribute_Unrestricted_Access =>
8140 if Is_Variable (P) then
8141 Note_Possible_Modification (P, Sure => False);
8144 -- The following comes from a query by Adam Beneschan, concerning
8145 -- improper use of universal_access in equality tests involving
8146 -- anonymous access types. Another good reason for 'Ref, but
8147 -- for now disable the test, which breaks several filed tests.
8149 if Ekind (Typ) = E_Anonymous_Access_Type
8150 and then Nkind_In (Parent (N), N_Op_Eq, N_Op_Ne)
8153 Error_Msg_N ("need unique type to resolve 'Access", N);
8154 Error_Msg_N ("\qualify attribute with some access type", N);
8157 if Is_Entity_Name (P) then
8158 if Is_Overloaded (P) then
8159 Get_First_Interp (P, Index, It);
8160 while Present (It.Nam) loop
8161 if Type_Conformant (Designated_Type (Typ), It.Nam) then
8162 Set_Entity (P, It.Nam);
8164 -- The prefix is definitely NOT overloaded anymore at
8165 -- this point, so we reset the Is_Overloaded flag to
8166 -- avoid any confusion when reanalyzing the node.
8168 Set_Is_Overloaded (P, False);
8169 Set_Is_Overloaded (N, False);
8170 Generate_Reference (Entity (P), P);
8174 Get_Next_Interp (Index, It);
8177 -- If Prefix is a subprogram name, it is frozen by this
8180 -- If it is a type, there is nothing to resolve.
8181 -- If it is an object, complete its resolution.
8183 elsif Is_Overloadable (Entity (P)) then
8185 -- Avoid insertion of freeze actions in spec expression mode
8187 if not In_Spec_Expression then
8188 Freeze_Before (N, Entity (P));
8191 elsif Is_Type (Entity (P)) then
8197 Error_Msg_Name_1 := Aname;
8199 if not Is_Entity_Name (P) then
8202 elsif Is_Overloadable (Entity (P))
8203 and then Is_Abstract_Subprogram (Entity (P))
8205 Error_Msg_F ("prefix of % attribute cannot be abstract", P);
8206 Set_Etype (N, Any_Type);
8208 elsif Convention (Entity (P)) = Convention_Intrinsic then
8209 if Ekind (Entity (P)) = E_Enumeration_Literal then
8211 ("prefix of % attribute cannot be enumeration literal",
8215 ("prefix of % attribute cannot be intrinsic", P);
8218 Set_Etype (N, Any_Type);
8221 -- Assignments, return statements, components of aggregates,
8222 -- generic instantiations will require convention checks if
8223 -- the type is an access to subprogram. Given that there will
8224 -- also be accessibility checks on those, this is where the
8225 -- checks can eventually be centralized ???
8227 if Ekind_In (Btyp, E_Access_Subprogram_Type,
8228 E_Anonymous_Access_Subprogram_Type,
8229 E_Access_Protected_Subprogram_Type,
8230 E_Anonymous_Access_Protected_Subprogram_Type)
8232 -- Deal with convention mismatch
8234 if Convention (Designated_Type (Btyp)) /=
8235 Convention (Entity (P))
8238 ("subprogram & has wrong convention", P, Entity (P));
8240 ("\does not match convention of access type &",
8243 if not Has_Convention_Pragma (Btyp) then
8245 ("\probable missing pragma Convention for &",
8250 Check_Subtype_Conformant
8251 (New_Id => Entity (P),
8252 Old_Id => Designated_Type (Btyp),
8256 if Attr_Id = Attribute_Unchecked_Access then
8257 Error_Msg_Name_1 := Aname;
8259 ("attribute% cannot be applied to a subprogram", P);
8261 elsif Aname = Name_Unrestricted_Access then
8262 null; -- Nothing to check
8264 -- Check the static accessibility rule of 3.10.2(32).
8265 -- This rule also applies within the private part of an
8266 -- instantiation. This rule does not apply to anonymous
8267 -- access-to-subprogram types in access parameters.
8269 elsif Attr_Id = Attribute_Access
8270 and then not In_Instance_Body
8272 (Ekind (Btyp) = E_Access_Subprogram_Type
8273 or else Is_Local_Anonymous_Access (Btyp))
8275 and then Subprogram_Access_Level (Entity (P)) >
8276 Type_Access_Level (Btyp)
8279 ("subprogram must not be deeper than access type", P);
8281 -- Check the restriction of 3.10.2(32) that disallows the
8282 -- access attribute within a generic body when the ultimate
8283 -- ancestor of the type of the attribute is declared outside
8284 -- of the generic unit and the subprogram is declared within
8285 -- that generic unit. This includes any such attribute that
8286 -- occurs within the body of a generic unit that is a child
8287 -- of the generic unit where the subprogram is declared.
8289 -- The rule also prohibits applying the attribute when the
8290 -- access type is a generic formal access type (since the
8291 -- level of the actual type is not known). This restriction
8292 -- does not apply when the attribute type is an anonymous
8293 -- access-to-subprogram type. Note that this check was
8294 -- revised by AI-229, because the originally Ada 95 rule
8295 -- was too lax. The original rule only applied when the
8296 -- subprogram was declared within the body of the generic,
8297 -- which allowed the possibility of dangling references).
8298 -- The rule was also too strict in some case, in that it
8299 -- didn't permit the access to be declared in the generic
8300 -- spec, whereas the revised rule does (as long as it's not
8303 -- There are a couple of subtleties of the test for applying
8304 -- the check that are worth noting. First, we only apply it
8305 -- when the levels of the subprogram and access type are the
8306 -- same (the case where the subprogram is statically deeper
8307 -- was applied above, and the case where the type is deeper
8308 -- is always safe). Second, we want the check to apply
8309 -- within nested generic bodies and generic child unit
8310 -- bodies, but not to apply to an attribute that appears in
8311 -- the generic unit's specification. This is done by testing
8312 -- that the attribute's innermost enclosing generic body is
8313 -- not the same as the innermost generic body enclosing the
8314 -- generic unit where the subprogram is declared (we don't
8315 -- want the check to apply when the access attribute is in
8316 -- the spec and there's some other generic body enclosing
8317 -- generic). Finally, there's no point applying the check
8318 -- when within an instance, because any violations will have
8319 -- been caught by the compilation of the generic unit.
8321 -- Note that we relax this check in CodePeer mode for
8322 -- compatibility with legacy code, since CodePeer is an
8323 -- Ada source code analyzer, not a strict compiler.
8324 -- ??? Note that a better approach would be to have a
8325 -- separate switch to relax this rule, and enable this
8326 -- switch in CodePeer mode.
8328 elsif Attr_Id = Attribute_Access
8329 and then not CodePeer_Mode
8330 and then not In_Instance
8331 and then Present (Enclosing_Generic_Unit (Entity (P)))
8332 and then Present (Enclosing_Generic_Body (N))
8333 and then Enclosing_Generic_Body (N) /=
8334 Enclosing_Generic_Body
8335 (Enclosing_Generic_Unit (Entity (P)))
8336 and then Subprogram_Access_Level (Entity (P)) =
8337 Type_Access_Level (Btyp)
8338 and then Ekind (Btyp) /=
8339 E_Anonymous_Access_Subprogram_Type
8340 and then Ekind (Btyp) /=
8341 E_Anonymous_Access_Protected_Subprogram_Type
8343 -- The attribute type's ultimate ancestor must be
8344 -- declared within the same generic unit as the
8345 -- subprogram is declared. The error message is
8346 -- specialized to say "ancestor" for the case where the
8347 -- access type is not its own ancestor, since saying
8348 -- simply "access type" would be very confusing.
8350 if Enclosing_Generic_Unit (Entity (P)) /=
8351 Enclosing_Generic_Unit (Root_Type (Btyp))
8354 ("''Access attribute not allowed in generic body",
8357 if Root_Type (Btyp) = Btyp then
8360 "access type & is declared outside " &
8361 "generic unit (RM 3.10.2(32))", N, Btyp);
8364 ("\because ancestor of " &
8365 "access type & is declared outside " &
8366 "generic unit (RM 3.10.2(32))", N, Btyp);
8370 ("\move ''Access to private part, or " &
8371 "(Ada 2005) use anonymous access type instead of &",
8374 -- If the ultimate ancestor of the attribute's type is
8375 -- a formal type, then the attribute is illegal because
8376 -- the actual type might be declared at a higher level.
8377 -- The error message is specialized to say "ancestor"
8378 -- for the case where the access type is not its own
8379 -- ancestor, since saying simply "access type" would be
8382 elsif Is_Generic_Type (Root_Type (Btyp)) then
8383 if Root_Type (Btyp) = Btyp then
8385 ("access type must not be a generic formal type",
8389 ("ancestor access type must not be a generic " &
8396 -- If this is a renaming, an inherited operation, or a
8397 -- subprogram instance, use the original entity. This may make
8398 -- the node type-inconsistent, so this transformation can only
8399 -- be done if the node will not be reanalyzed. In particular,
8400 -- if it is within a default expression, the transformation
8401 -- must be delayed until the default subprogram is created for
8402 -- it, when the enclosing subprogram is frozen.
8404 if Is_Entity_Name (P)
8405 and then Is_Overloadable (Entity (P))
8406 and then Present (Alias (Entity (P)))
8407 and then Expander_Active
8410 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
8413 elsif Nkind (P) = N_Selected_Component
8414 and then Is_Overloadable (Entity (Selector_Name (P)))
8416 -- Protected operation. If operation is overloaded, must
8417 -- disambiguate. Prefix that denotes protected object itself
8418 -- is resolved with its own type.
8420 if Attr_Id = Attribute_Unchecked_Access then
8421 Error_Msg_Name_1 := Aname;
8423 ("attribute% cannot be applied to protected operation", P);
8426 Resolve (Prefix (P));
8427 Generate_Reference (Entity (Selector_Name (P)), P);
8429 elsif Is_Overloaded (P) then
8431 -- Use the designated type of the context to disambiguate
8432 -- Note that this was not strictly conformant to Ada 95,
8433 -- but was the implementation adopted by most Ada 95 compilers.
8434 -- The use of the context type to resolve an Access attribute
8435 -- reference is now mandated in AI-235 for Ada 2005.
8438 Index : Interp_Index;
8442 Get_First_Interp (P, Index, It);
8443 while Present (It.Typ) loop
8444 if Covers (Designated_Type (Typ), It.Typ) then
8445 Resolve (P, It.Typ);
8449 Get_Next_Interp (Index, It);
8456 -- X'Access is illegal if X denotes a constant and the access type
8457 -- is access-to-variable. Same for 'Unchecked_Access. The rule
8458 -- does not apply to 'Unrestricted_Access. If the reference is a
8459 -- default-initialized aggregate component for a self-referential
8460 -- type the reference is legal.
8462 if not (Ekind (Btyp) = E_Access_Subprogram_Type
8463 or else Ekind (Btyp) = E_Anonymous_Access_Subprogram_Type
8464 or else (Is_Record_Type (Btyp)
8466 Present (Corresponding_Remote_Type (Btyp)))
8467 or else Ekind (Btyp) = E_Access_Protected_Subprogram_Type
8468 or else Ekind (Btyp)
8469 = E_Anonymous_Access_Protected_Subprogram_Type
8470 or else Is_Access_Constant (Btyp)
8471 or else Is_Variable (P)
8472 or else Attr_Id = Attribute_Unrestricted_Access)
8474 if Is_Entity_Name (P)
8475 and then Is_Type (Entity (P))
8477 -- Legality of a self-reference through an access
8478 -- attribute has been verified in Analyze_Access_Attribute.
8482 elsif Comes_From_Source (N) then
8483 Error_Msg_F ("access-to-variable designates constant", P);
8487 Des_Btyp := Designated_Type (Btyp);
8489 if Ada_Version >= Ada_2005
8490 and then Is_Incomplete_Type (Des_Btyp)
8492 -- Ada 2005 (AI-412): If the (sub)type is a limited view of an
8493 -- imported entity, and the non-limited view is visible, make
8494 -- use of it. If it is an incomplete subtype, use the base type
8497 if From_With_Type (Des_Btyp)
8498 and then Present (Non_Limited_View (Des_Btyp))
8500 Des_Btyp := Non_Limited_View (Des_Btyp);
8502 elsif Ekind (Des_Btyp) = E_Incomplete_Subtype then
8503 Des_Btyp := Etype (Des_Btyp);
8507 if (Attr_Id = Attribute_Access
8509 Attr_Id = Attribute_Unchecked_Access)
8510 and then (Ekind (Btyp) = E_General_Access_Type
8511 or else Ekind (Btyp) = E_Anonymous_Access_Type)
8513 -- Ada 2005 (AI-230): Check the accessibility of anonymous
8514 -- access types for stand-alone objects, record and array
8515 -- components, and return objects. For a component definition
8516 -- the level is the same of the enclosing composite type.
8518 if Ada_Version >= Ada_2005
8519 and then (Is_Local_Anonymous_Access (Btyp)
8521 -- Handle cases where Btyp is the
8522 -- anonymous access type of an Ada 2012
8523 -- stand-alone object.
8525 or else Nkind (Associated_Node_For_Itype (Btyp)) =
8526 N_Object_Declaration)
8527 and then Object_Access_Level (P)
8528 > Deepest_Type_Access_Level (Btyp)
8529 and then Attr_Id = Attribute_Access
8531 -- In an instance, this is a runtime check, but one we
8532 -- know will fail, so generate an appropriate warning.
8534 if In_Instance_Body then
8536 ("?non-local pointer cannot point to local object", P);
8538 ("\?Program_Error will be raised at run time", P);
8540 Make_Raise_Program_Error (Loc,
8541 Reason => PE_Accessibility_Check_Failed));
8546 ("non-local pointer cannot point to local object", P);
8550 if Is_Dependent_Component_Of_Mutable_Object (P) then
8552 ("illegal attribute for discriminant-dependent component",
8556 -- Check static matching rule of 3.10.2(27). Nominal subtype
8557 -- of the prefix must statically match the designated type.
8559 Nom_Subt := Etype (P);
8561 if Is_Constr_Subt_For_U_Nominal (Nom_Subt) then
8562 Nom_Subt := Base_Type (Nom_Subt);
8565 if Is_Tagged_Type (Designated_Type (Typ)) then
8567 -- If the attribute is in the context of an access
8568 -- parameter, then the prefix is allowed to be of the
8569 -- class-wide type (by AI-127).
8571 if Ekind (Typ) = E_Anonymous_Access_Type then
8572 if not Covers (Designated_Type (Typ), Nom_Subt)
8573 and then not Covers (Nom_Subt, Designated_Type (Typ))
8579 Desig := Designated_Type (Typ);
8581 if Is_Class_Wide_Type (Desig) then
8582 Desig := Etype (Desig);
8585 if Is_Anonymous_Tagged_Base (Nom_Subt, Desig) then
8590 ("type of prefix: & not compatible",
8593 ("\with &, the expected designated type",
8594 P, Designated_Type (Typ));
8599 elsif not Covers (Designated_Type (Typ), Nom_Subt)
8601 (not Is_Class_Wide_Type (Designated_Type (Typ))
8602 and then Is_Class_Wide_Type (Nom_Subt))
8605 ("type of prefix: & is not covered", P, Nom_Subt);
8607 ("\by &, the expected designated type" &
8608 " (RM 3.10.2 (27))", P, Designated_Type (Typ));
8611 if Is_Class_Wide_Type (Designated_Type (Typ))
8612 and then Has_Discriminants (Etype (Designated_Type (Typ)))
8613 and then Is_Constrained (Etype (Designated_Type (Typ)))
8614 and then Designated_Type (Typ) /= Nom_Subt
8616 Apply_Discriminant_Check
8617 (N, Etype (Designated_Type (Typ)));
8620 -- Ada 2005 (AI-363): Require static matching when designated
8621 -- type has discriminants and a constrained partial view, since
8622 -- in general objects of such types are mutable, so we can't
8623 -- allow the access value to designate a constrained object
8624 -- (because access values must be assumed to designate mutable
8625 -- objects when designated type does not impose a constraint).
8627 elsif Subtypes_Statically_Match (Des_Btyp, Nom_Subt) then
8630 elsif Has_Discriminants (Designated_Type (Typ))
8631 and then not Is_Constrained (Des_Btyp)
8633 (Ada_Version < Ada_2005
8635 not Effectively_Has_Constrained_Partial_View
8636 (Typ => Designated_Type (Base_Type (Typ)),
8637 Scop => Current_Scope))
8643 ("object subtype must statically match "
8644 & "designated subtype", P);
8646 if Is_Entity_Name (P)
8647 and then Is_Array_Type (Designated_Type (Typ))
8650 D : constant Node_Id := Declaration_Node (Entity (P));
8652 Error_Msg_N ("aliased object has explicit bounds?",
8654 Error_Msg_N ("\declare without bounds"
8655 & " (and with explicit initialization)?", D);
8656 Error_Msg_N ("\for use with unconstrained access?", D);
8661 -- Check the static accessibility rule of 3.10.2(28). Note that
8662 -- this check is not performed for the case of an anonymous
8663 -- access type, since the access attribute is always legal
8664 -- in such a context.
8666 if Attr_Id /= Attribute_Unchecked_Access
8668 Object_Access_Level (P) > Deepest_Type_Access_Level (Btyp)
8669 and then Ekind (Btyp) = E_General_Access_Type
8671 Accessibility_Message;
8676 if Ekind_In (Btyp, E_Access_Protected_Subprogram_Type,
8677 E_Anonymous_Access_Protected_Subprogram_Type)
8679 if Is_Entity_Name (P)
8680 and then not Is_Protected_Type (Scope (Entity (P)))
8682 Error_Msg_F ("context requires a protected subprogram", P);
8684 -- Check accessibility of protected object against that of the
8685 -- access type, but only on user code, because the expander
8686 -- creates access references for handlers. If the context is an
8687 -- anonymous_access_to_protected, there are no accessibility
8688 -- checks either. Omit check entirely for Unrestricted_Access.
8690 elsif Object_Access_Level (P) > Deepest_Type_Access_Level (Btyp)
8691 and then Comes_From_Source (N)
8692 and then Ekind (Btyp) = E_Access_Protected_Subprogram_Type
8693 and then Attr_Id /= Attribute_Unrestricted_Access
8695 Accessibility_Message;
8699 elsif Ekind_In (Btyp, E_Access_Subprogram_Type,
8700 E_Anonymous_Access_Subprogram_Type)
8701 and then Ekind (Etype (N)) = E_Access_Protected_Subprogram_Type
8703 Error_Msg_F ("context requires a non-protected subprogram", P);
8706 -- The context cannot be a pool-specific type, but this is a
8707 -- legality rule, not a resolution rule, so it must be checked
8708 -- separately, after possibly disambiguation (see AI-245).
8710 if Ekind (Btyp) = E_Access_Type
8711 and then Attr_Id /= Attribute_Unrestricted_Access
8713 Wrong_Type (N, Typ);
8716 -- The context may be a constrained access type (however ill-
8717 -- advised such subtypes might be) so in order to generate a
8718 -- constraint check when needed set the type of the attribute
8719 -- reference to the base type of the context.
8721 Set_Etype (N, Btyp);
8723 -- Check for incorrect atomic/volatile reference (RM C.6(12))
8725 if Attr_Id /= Attribute_Unrestricted_Access then
8726 if Is_Atomic_Object (P)
8727 and then not Is_Atomic (Designated_Type (Typ))
8730 ("access to atomic object cannot yield access-to-" &
8731 "non-atomic type", P);
8733 elsif Is_Volatile_Object (P)
8734 and then not Is_Volatile (Designated_Type (Typ))
8737 ("access to volatile object cannot yield access-to-" &
8738 "non-volatile type", P);
8742 if Is_Entity_Name (P) then
8743 Set_Address_Taken (Entity (P));
8745 end Access_Attribute;
8751 -- Deal with resolving the type for Address attribute, overloading
8752 -- is not permitted here, since there is no context to resolve it.
8754 when Attribute_Address | Attribute_Code_Address =>
8755 Address_Attribute : begin
8757 -- To be safe, assume that if the address of a variable is taken,
8758 -- it may be modified via this address, so note modification.
8760 if Is_Variable (P) then
8761 Note_Possible_Modification (P, Sure => False);
8764 if Nkind (P) in N_Subexpr
8765 and then Is_Overloaded (P)
8767 Get_First_Interp (P, Index, It);
8768 Get_Next_Interp (Index, It);
8770 if Present (It.Nam) then
8771 Error_Msg_Name_1 := Aname;
8773 ("prefix of % attribute cannot be overloaded", P);
8777 if not Is_Entity_Name (P)
8778 or else not Is_Overloadable (Entity (P))
8780 if not Is_Task_Type (Etype (P))
8781 or else Nkind (P) = N_Explicit_Dereference
8787 -- If this is the name of a derived subprogram, or that of a
8788 -- generic actual, the address is that of the original entity.
8790 if Is_Entity_Name (P)
8791 and then Is_Overloadable (Entity (P))
8792 and then Present (Alias (Entity (P)))
8795 New_Occurrence_Of (Alias (Entity (P)), Sloc (P)));
8798 if Is_Entity_Name (P) then
8799 Set_Address_Taken (Entity (P));
8802 if Nkind (P) = N_Slice then
8804 -- Arr (X .. Y)'address is identical to Arr (X)'address,
8805 -- even if the array is packed and the slice itself is not
8806 -- addressable. Transform the prefix into an indexed component.
8808 -- Note that the transformation is safe only if we know that
8809 -- the slice is non-null. That is because a null slice can have
8810 -- an out of bounds index value.
8812 -- Right now, gigi blows up if given 'Address on a slice as a
8813 -- result of some incorrect freeze nodes generated by the front
8814 -- end, and this covers up that bug in one case, but the bug is
8815 -- likely still there in the cases not handled by this code ???
8817 -- It's not clear what 'Address *should* return for a null
8818 -- slice with out of bounds indexes, this might be worth an ARG
8821 -- One approach would be to do a length check unconditionally,
8822 -- and then do the transformation below unconditionally, but
8823 -- analyze with checks off, avoiding the problem of the out of
8824 -- bounds index. This approach would interpret the address of
8825 -- an out of bounds null slice as being the address where the
8826 -- array element would be if there was one, which is probably
8827 -- as reasonable an interpretation as any ???
8830 Loc : constant Source_Ptr := Sloc (P);
8831 D : constant Node_Id := Discrete_Range (P);
8835 if Is_Entity_Name (D)
8838 (Type_Low_Bound (Entity (D)),
8839 Type_High_Bound (Entity (D)))
8842 Make_Attribute_Reference (Loc,
8843 Prefix => (New_Occurrence_Of (Entity (D), Loc)),
8844 Attribute_Name => Name_First);
8846 elsif Nkind (D) = N_Range
8847 and then Not_Null_Range (Low_Bound (D), High_Bound (D))
8849 Lo := Low_Bound (D);
8855 if Present (Lo) then
8857 Make_Indexed_Component (Loc,
8858 Prefix => Relocate_Node (Prefix (P)),
8859 Expressions => New_List (Lo)));
8861 Analyze_And_Resolve (P);
8865 end Address_Attribute;
8871 -- Prefix of the AST_Entry attribute is an entry name which must
8872 -- not be resolved, since this is definitely not an entry call.
8874 when Attribute_AST_Entry =>
8881 -- Prefix of Body_Version attribute can be a subprogram name which
8882 -- must not be resolved, since this is not a call.
8884 when Attribute_Body_Version =>
8891 -- Prefix of Caller attribute is an entry name which must not
8892 -- be resolved, since this is definitely not an entry call.
8894 when Attribute_Caller =>
8901 -- Shares processing with Address attribute
8907 -- If the prefix of the Count attribute is an entry name it must not
8908 -- be resolved, since this is definitely not an entry call. However,
8909 -- if it is an element of an entry family, the index itself may
8910 -- have to be resolved because it can be a general expression.
8912 when Attribute_Count =>
8913 if Nkind (P) = N_Indexed_Component
8914 and then Is_Entity_Name (Prefix (P))
8917 Indx : constant Node_Id := First (Expressions (P));
8918 Fam : constant Entity_Id := Entity (Prefix (P));
8920 Resolve (Indx, Entry_Index_Type (Fam));
8921 Apply_Range_Check (Indx, Entry_Index_Type (Fam));
8929 -- Prefix of the Elaborated attribute is a subprogram name which
8930 -- must not be resolved, since this is definitely not a call. Note
8931 -- that it is a library unit, so it cannot be overloaded here.
8933 when Attribute_Elaborated =>
8940 -- Prefix of Enabled attribute is a check name, which must be treated
8941 -- specially and not touched by Resolve.
8943 when Attribute_Enabled =>
8946 --------------------
8947 -- Mechanism_Code --
8948 --------------------
8950 -- Prefix of the Mechanism_Code attribute is a function name
8951 -- which must not be resolved. Should we check for overloaded ???
8953 when Attribute_Mechanism_Code =>
8960 -- Most processing is done in sem_dist, after determining the
8961 -- context type. Node is rewritten as a conversion to a runtime call.
8963 when Attribute_Partition_ID =>
8964 Process_Partition_Id (N);
8971 when Attribute_Pool_Address =>
8978 -- We replace the Range attribute node with a range expression whose
8979 -- bounds are the 'First and 'Last attributes applied to the same
8980 -- prefix. The reason that we do this transformation here instead of
8981 -- in the expander is that it simplifies other parts of the semantic
8982 -- analysis which assume that the Range has been replaced; thus it
8983 -- must be done even when in semantic-only mode (note that the RM
8984 -- specifically mentions this equivalence, we take care that the
8985 -- prefix is only evaluated once).
8987 when Attribute_Range => Range_Attribute :
8994 if not Is_Entity_Name (P)
8995 or else not Is_Type (Entity (P))
9000 Dims := Expressions (N);
9003 Make_Attribute_Reference (Loc,
9005 Duplicate_Subexpr (P, Name_Req => True),
9006 Attribute_Name => Name_Last,
9007 Expressions => Dims);
9010 Make_Attribute_Reference (Loc,
9012 Attribute_Name => Name_First,
9013 Expressions => (Dims));
9015 -- Do not share the dimension indicator, if present. Even
9016 -- though it is a static constant, its source location
9017 -- may be modified when printing expanded code and node
9018 -- sharing will lead to chaos in Sprint.
9020 if Present (Dims) then
9021 Set_Expressions (LB,
9022 New_List (New_Copy_Tree (First (Dims))));
9025 -- If the original was marked as Must_Not_Freeze (see code
9026 -- in Sem_Ch3.Make_Index), then make sure the rewriting
9027 -- does not freeze either.
9029 if Must_Not_Freeze (N) then
9030 Set_Must_Not_Freeze (HB);
9031 Set_Must_Not_Freeze (LB);
9032 Set_Must_Not_Freeze (Prefix (HB));
9033 Set_Must_Not_Freeze (Prefix (LB));
9036 if Raises_Constraint_Error (Prefix (N)) then
9038 -- Preserve Sloc of prefix in the new bounds, so that
9039 -- the posted warning can be removed if we are within
9040 -- unreachable code.
9042 Set_Sloc (LB, Sloc (Prefix (N)));
9043 Set_Sloc (HB, Sloc (Prefix (N)));
9046 Rewrite (N, Make_Range (Loc, LB, HB));
9047 Analyze_And_Resolve (N, Typ);
9049 -- Ensure that the expanded range does not have side effects
9051 Force_Evaluation (LB);
9052 Force_Evaluation (HB);
9054 -- Normally after resolving attribute nodes, Eval_Attribute
9055 -- is called to do any possible static evaluation of the node.
9056 -- However, here since the Range attribute has just been
9057 -- transformed into a range expression it is no longer an
9058 -- attribute node and therefore the call needs to be avoided
9059 -- and is accomplished by simply returning from the procedure.
9062 end Range_Attribute;
9068 -- We will only come here during the prescan of a spec expression
9069 -- containing a Result attribute. In that case the proper Etype has
9070 -- already been set, and nothing more needs to be done here.
9072 when Attribute_Result =>
9079 -- Prefix must not be resolved in this case, since it is not a
9080 -- real entity reference. No action of any kind is require!
9082 when Attribute_UET_Address =>
9085 ----------------------
9086 -- Unchecked_Access --
9087 ----------------------
9089 -- Processing is shared with Access
9091 -------------------------
9092 -- Unrestricted_Access --
9093 -------------------------
9095 -- Processing is shared with Access
9101 -- Apply range check. Note that we did not do this during the
9102 -- analysis phase, since we wanted Eval_Attribute to have a
9103 -- chance at finding an illegal out of range value.
9105 when Attribute_Val =>
9107 -- Note that we do our own Eval_Attribute call here rather than
9108 -- use the common one, because we need to do processing after
9109 -- the call, as per above comment.
9113 -- Eval_Attribute may replace the node with a raise CE, or
9114 -- fold it to a constant. Obviously we only apply a scalar
9115 -- range check if this did not happen!
9117 if Nkind (N) = N_Attribute_Reference
9118 and then Attribute_Name (N) = Name_Val
9120 Apply_Scalar_Range_Check (First (Expressions (N)), Btyp);
9129 -- Prefix of Version attribute can be a subprogram name which
9130 -- must not be resolved, since this is not a call.
9132 when Attribute_Version =>
9135 ----------------------
9136 -- Other Attributes --
9137 ----------------------
9139 -- For other attributes, resolve prefix unless it is a type. If
9140 -- the attribute reference itself is a type name ('Base and 'Class)
9141 -- then this is only legal within a task or protected record.
9144 if not Is_Entity_Name (P)
9145 or else not Is_Type (Entity (P))
9150 -- If the attribute reference itself is a type name ('Base,
9151 -- 'Class) then this is only legal within a task or protected
9152 -- record. What is this all about ???
9154 if Is_Entity_Name (N)
9155 and then Is_Type (Entity (N))
9157 if Is_Concurrent_Type (Entity (N))
9158 and then In_Open_Scopes (Entity (P))
9163 ("invalid use of subtype name in expression or call", N);
9167 -- For attributes whose argument may be a string, complete
9168 -- resolution of argument now. This avoids premature expansion
9169 -- (and the creation of transient scopes) before the attribute
9170 -- reference is resolved.
9173 when Attribute_Value =>
9174 Resolve (First (Expressions (N)), Standard_String);
9176 when Attribute_Wide_Value =>
9177 Resolve (First (Expressions (N)), Standard_Wide_String);
9179 when Attribute_Wide_Wide_Value =>
9180 Resolve (First (Expressions (N)), Standard_Wide_Wide_String);
9182 when others => null;
9185 -- If the prefix of the attribute is a class-wide type then it
9186 -- will be expanded into a dispatching call to a predefined
9187 -- primitive. Therefore we must check for potential violation
9188 -- of such restriction.
9190 if Is_Class_Wide_Type (Etype (P)) then
9191 Check_Restriction (No_Dispatching_Calls, N);
9195 -- Normally the Freezing is done by Resolve but sometimes the Prefix
9196 -- is not resolved, in which case the freezing must be done now.
9198 Freeze_Expression (P);
9200 -- Finally perform static evaluation on the attribute reference
9203 end Resolve_Attribute;
9205 --------------------------------
9206 -- Stream_Attribute_Available --
9207 --------------------------------
9209 function Stream_Attribute_Available
9211 Nam : TSS_Name_Type;
9212 Partial_View : Node_Id := Empty) return Boolean
9214 Etyp : Entity_Id := Typ;
9216 -- Start of processing for Stream_Attribute_Available
9219 -- We need some comments in this body ???
9221 if Has_Stream_Attribute_Definition (Typ, Nam) then
9225 if Is_Class_Wide_Type (Typ) then
9226 return not Is_Limited_Type (Typ)
9227 or else Stream_Attribute_Available (Etype (Typ), Nam);
9230 if Nam = TSS_Stream_Input
9231 and then Is_Abstract_Type (Typ)
9232 and then not Is_Class_Wide_Type (Typ)
9237 if not (Is_Limited_Type (Typ)
9238 or else (Present (Partial_View)
9239 and then Is_Limited_Type (Partial_View)))
9244 -- In Ada 2005, Input can invoke Read, and Output can invoke Write
9246 if Nam = TSS_Stream_Input
9247 and then Ada_Version >= Ada_2005
9248 and then Stream_Attribute_Available (Etyp, TSS_Stream_Read)
9252 elsif Nam = TSS_Stream_Output
9253 and then Ada_Version >= Ada_2005
9254 and then Stream_Attribute_Available (Etyp, TSS_Stream_Write)
9259 -- Case of Read and Write: check for attribute definition clause that
9260 -- applies to an ancestor type.
9262 while Etype (Etyp) /= Etyp loop
9263 Etyp := Etype (Etyp);
9265 if Has_Stream_Attribute_Definition (Etyp, Nam) then
9270 if Ada_Version < Ada_2005 then
9272 -- In Ada 95 mode, also consider a non-visible definition
9275 Btyp : constant Entity_Id := Implementation_Base_Type (Typ);
9278 and then Stream_Attribute_Available
9279 (Btyp, Nam, Partial_View => Typ);
9284 end Stream_Attribute_Available;