1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
9 -- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING3. If not, go to --
19 -- http://www.gnu.org/licenses for a complete copy of the license. --
21 -- GNAT was originally developed by the GNAT team at New York University. --
22 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 ------------------------------------------------------------------------------
26 with Ada
.Characters
.Latin_1
; use Ada
.Characters
.Latin_1
;
28 with Atree
; use Atree
;
29 with Casing
; use Casing
;
30 with Checks
; use Checks
;
31 with Einfo
; use Einfo
;
32 with Errout
; use Errout
;
34 with Exp_Dist
; use Exp_Dist
;
35 with Exp_Util
; use Exp_Util
;
36 with Expander
; use Expander
;
37 with Freeze
; use Freeze
;
38 with Gnatvsn
; use Gnatvsn
;
39 with Itypes
; use Itypes
;
41 with Lib
.Xref
; use Lib
.Xref
;
42 with Nlists
; use Nlists
;
43 with Nmake
; use Nmake
;
45 with Restrict
; use Restrict
;
46 with Rident
; use Rident
;
47 with Rtsfind
; use Rtsfind
;
48 with Sdefault
; use Sdefault
;
50 with Sem_Aux
; use Sem_Aux
;
51 with Sem_Cat
; use Sem_Cat
;
52 with Sem_Ch6
; use Sem_Ch6
;
53 with Sem_Ch8
; use Sem_Ch8
;
54 with Sem_Ch10
; use Sem_Ch10
;
55 with Sem_Dist
; use Sem_Dist
;
56 with Sem_Elim
; use Sem_Elim
;
57 with Sem_Eval
; use Sem_Eval
;
58 with Sem_Res
; use Sem_Res
;
59 with Sem_Type
; use Sem_Type
;
60 with Sem_Util
; use Sem_Util
;
61 with Stand
; use Stand
;
62 with Sinfo
; use Sinfo
;
63 with Sinput
; use Sinput
;
64 with Stringt
; use Stringt
;
66 with Stylesw
; use Stylesw
;
67 with Targparm
; use Targparm
;
68 with Ttypes
; use Ttypes
;
69 with Tbuild
; use Tbuild
;
70 with Uintp
; use Uintp
;
71 with Urealp
; use Urealp
;
73 package body Sem_Attr
is
75 True_Value
: constant Uint
:= Uint_1
;
76 False_Value
: constant Uint
:= Uint_0
;
77 -- Synonyms to be used when these constants are used as Boolean values
79 Bad_Attribute
: exception;
80 -- Exception raised if an error is detected during attribute processing,
81 -- used so that we can abandon the processing so we don't run into
82 -- trouble with cascaded errors.
84 -- The following array is the list of attributes defined in the Ada 83 RM
85 -- that are not included in Ada 95, but still get recognized in GNAT.
87 Attribute_83
: constant Attribute_Class_Array
:= Attribute_Class_Array
'(
93 Attribute_Constrained |
100 Attribute_First_Bit |
106 Attribute_Leading_Part |
108 Attribute_Machine_Emax |
109 Attribute_Machine_Emin |
110 Attribute_Machine_Mantissa |
111 Attribute_Machine_Overflows |
112 Attribute_Machine_Radix |
113 Attribute_Machine_Rounds |
119 Attribute_Safe_Emax |
120 Attribute_Safe_Large |
121 Attribute_Safe_Small |
124 Attribute_Storage_Size |
126 Attribute_Terminated |
129 Attribute_Width => True,
132 -- The following array is the list of attributes defined in the Ada 2005
133 -- RM which are not defined in Ada 95. These are recognized in Ada 95 mode,
134 -- but in Ada 95 they are considered to be implementation defined.
136 Attribute_05 : constant Attribute_Class_Array := Attribute_Class_Array'(
137 Attribute_Machine_Rounding |
140 Attribute_Stream_Size |
141 Attribute_Wide_Wide_Width
=> True,
144 -- The following array contains all attributes that imply a modification
145 -- of their prefixes or result in an access value. Such prefixes can be
146 -- considered as lvalues.
148 Attribute_Name_Implies_Lvalue_Prefix
: constant Attribute_Class_Array
:=
149 Attribute_Class_Array
'(
154 Attribute_Unchecked_Access |
155 Attribute_Unrestricted_Access => True,
158 -----------------------
159 -- Local_Subprograms --
160 -----------------------
162 procedure Eval_Attribute (N : Node_Id);
163 -- Performs compile time evaluation of attributes where possible, leaving
164 -- the Is_Static_Expression/Raises_Constraint_Error flags appropriately
165 -- set, and replacing the node with a literal node if the value can be
166 -- computed at compile time. All static attribute references are folded,
167 -- as well as a number of cases of non-static attributes that can always
168 -- be computed at compile time (e.g. floating-point model attributes that
169 -- are applied to non-static subtypes). Of course in such cases, the
170 -- Is_Static_Expression flag will not be set on the resulting literal.
171 -- Note that the only required action of this procedure is to catch the
172 -- static expression cases as described in the RM. Folding of other cases
173 -- is done where convenient, but some additional non-static folding is in
174 -- N_Expand_Attribute_Reference in cases where this is more convenient.
176 function Is_Anonymous_Tagged_Base
180 -- For derived tagged types that constrain parent discriminants we build
181 -- an anonymous unconstrained base type. We need to recognize the relation
182 -- between the two when analyzing an access attribute for a constrained
183 -- component, before the full declaration for Typ has been analyzed, and
184 -- where therefore the prefix of the attribute does not match the enclosing
187 -----------------------
188 -- Analyze_Attribute --
189 -----------------------
191 procedure Analyze_Attribute (N : Node_Id) is
192 Loc : constant Source_Ptr := Sloc (N);
193 Aname : constant Name_Id := Attribute_Name (N);
194 P : constant Node_Id := Prefix (N);
195 Exprs : constant List_Id := Expressions (N);
196 Attr_Id : constant Attribute_Id := Get_Attribute_Id (Aname);
201 -- Type of prefix after analysis
203 P_Base_Type : Entity_Id;
204 -- Base type of prefix after analysis
206 -----------------------
207 -- Local Subprograms --
208 -----------------------
210 procedure Analyze_Access_Attribute;
211 -- Used for Access, Unchecked_Access, Unrestricted_Access attributes.
212 -- Internally, Id distinguishes which of the three cases is involved.
214 procedure Bad_Attribute_For_Predicate;
215 -- Output error message for use of a predicate (First, Last, Range) not
216 -- allowed with a type that has predicates. If the type is a generic
217 -- actual, then the message is a warning, and we generate code to raise
218 -- program error with an appropriate reason. No error message is given
219 -- for internally generated uses of the attributes.
221 procedure Check_Array_Or_Scalar_Type;
222 -- Common procedure used by First, Last, Range attribute to check
223 -- that the prefix is a constrained array or scalar type, or a name
224 -- of an array object, and that an argument appears only if appropriate
225 -- (i.e. only in the array case).
227 procedure Check_Array_Type;
228 -- Common semantic checks for all array attributes. Checks that the
229 -- prefix is a constrained array type or the name of an array object.
230 -- The error message for non-arrays is specialized appropriately.
232 procedure Check_Asm_Attribute;
233 -- Common semantic checks for Asm_Input and Asm_Output attributes
235 procedure Check_Component;
236 -- Common processing for Bit_Position, First_Bit, Last_Bit, and
237 -- Position. Checks prefix is an appropriate selected component.
239 procedure Check_Decimal_Fixed_Point_Type;
240 -- Check that prefix of attribute N is a decimal fixed-point type
242 procedure Check_Dereference;
243 -- If the prefix of attribute is an object of an access type, then
244 -- introduce an explicit dereference, and adjust P_Type accordingly.
246 procedure Check_Discrete_Type;
247 -- Verify that prefix of attribute N is a discrete type
250 -- Check that no attribute arguments are present
252 procedure Check_Either_E0_Or_E1;
253 -- Check that there are zero or one attribute arguments present
256 -- Check that exactly one attribute argument is present
259 -- Check that two attribute arguments are present
261 procedure Check_Enum_Image;
262 -- If the prefix type is an enumeration type, set all its literals
263 -- as referenced, since the image function could possibly end up
264 -- referencing any of the literals indirectly. Same for Enum_Val.
266 procedure Check_Fixed_Point_Type;
267 -- Verify that prefix of attribute N is a fixed type
269 procedure Check_Fixed_Point_Type_0;
270 -- Verify that prefix of attribute N is a fixed type and that
271 -- no attribute expressions are present
273 procedure Check_Floating_Point_Type;
274 -- Verify that prefix of attribute N is a float type
276 procedure Check_Floating_Point_Type_0;
277 -- Verify that prefix of attribute N is a float type and that
278 -- no attribute expressions are present
280 procedure Check_Floating_Point_Type_1;
281 -- Verify that prefix of attribute N is a float type and that
282 -- exactly one attribute expression is present
284 procedure Check_Floating_Point_Type_2;
285 -- Verify that prefix of attribute N is a float type and that
286 -- two attribute expressions are present
288 procedure Legal_Formal_Attribute;
289 -- Common processing for attributes Definite and Has_Discriminants.
290 -- Checks that prefix is generic indefinite formal type.
292 procedure Check_Integer_Type;
293 -- Verify that prefix of attribute N is an integer type
295 procedure Check_Library_Unit;
296 -- Verify that prefix of attribute N is a library unit
298 procedure Check_Modular_Integer_Type;
299 -- Verify that prefix of attribute N is a modular integer type
301 procedure Check_Not_CPP_Type;
302 -- Check that P (the prefix of the attribute) is not an CPP type
303 -- for which no Ada predefined primitive is available.
305 procedure Check_Not_Incomplete_Type;
306 -- Check that P (the prefix of the attribute) is not an incomplete
307 -- type or a private type for which no full view has been given.
309 procedure Check_Object_Reference (P : Node_Id);
310 -- Check that P (the prefix of the attribute) is an object reference
312 procedure Check_Program_Unit;
313 -- Verify that prefix of attribute N is a program unit
315 procedure Check_Real_Type;
316 -- Verify that prefix of attribute N is fixed or float type
318 procedure Check_Scalar_Type;
319 -- Verify that prefix of attribute N is a scalar type
321 procedure Check_Standard_Prefix;
322 -- Verify that prefix of attribute N is package Standard
324 procedure Check_Stream_Attribute (Nam : TSS_Name_Type);
325 -- Validity checking for stream attribute. Nam is the TSS name of the
326 -- corresponding possible defined attribute function (e.g. for the
327 -- Read attribute, Nam will be TSS_Stream_Read).
329 procedure Check_PolyORB_Attribute;
330 -- Validity checking for PolyORB/DSA attribute
332 procedure Check_Task_Prefix;
333 -- Verify that prefix of attribute N is a task or task type
335 procedure Check_Type;
336 -- Verify that the prefix of attribute N is a type
338 procedure Check_Unit_Name (Nod : Node_Id);
339 -- Check that Nod is of the form of a library unit name, i.e that
340 -- it is an identifier, or a selected component whose prefix is
341 -- itself of the form of a library unit name. Note that this is
342 -- quite different from Check_Program_Unit, since it only checks
343 -- the syntactic form of the name, not the semantic identity. This
344 -- is because it is used with attributes (Elab_Body, Elab_Spec, and
345 -- UET_Address) which can refer to non-visible unit.
347 procedure Error_Attr (Msg : String; Error_Node : Node_Id);
348 pragma No_Return (Error_Attr);
349 procedure Error_Attr;
350 pragma No_Return (Error_Attr);
351 -- Posts error using Error_Msg_N at given node, sets type of attribute
352 -- node to Any_Type, and then raises Bad_Attribute to avoid any further
353 -- semantic processing. The message typically contains a % insertion
354 -- character which is replaced by the attribute name. The call with
355 -- no arguments is used when the caller has already generated the
356 -- required error messages.
358 procedure Error_Attr_P (Msg : String);
359 pragma No_Return (Error_Attr);
360 -- Like Error_Attr, but error is posted at the start of the prefix
362 procedure Standard_Attribute (Val : Int);
363 -- Used to process attributes whose prefix is package Standard which
364 -- yield values of type Universal_Integer. The attribute reference
365 -- node is rewritten with an integer literal of the given value.
367 procedure Unexpected_Argument (En : Node_Id);
368 -- Signal unexpected attribute argument (En is the argument)
370 procedure Validate_Non_Static_Attribute_Function_Call;
371 -- Called when processing an attribute that is a function call to a
372 -- non-static function, i.e. an attribute function that either takes
373 -- non-scalar arguments or returns a non-scalar result. Verifies that
374 -- such a call does not appear in a preelaborable context.
376 ------------------------------
377 -- Analyze_Access_Attribute --
378 ------------------------------
380 procedure Analyze_Access_Attribute is
381 Acc_Type : Entity_Id;
386 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id;
387 -- Build an access-to-object type whose designated type is DT,
388 -- and whose Ekind is appropriate to the attribute type. The
389 -- type that is constructed is returned as the result.
391 procedure Build_Access_Subprogram_Type (P : Node_Id);
392 -- Build an access to subprogram whose designated type is the type of
393 -- the prefix. If prefix is overloaded, so is the node itself. The
394 -- result is stored in Acc_Type.
396 function OK_Self_Reference return Boolean;
397 -- An access reference whose prefix is a type can legally appear
398 -- within an aggregate, where it is obtained by expansion of
399 -- a defaulted aggregate. The enclosing aggregate that contains
400 -- the self-referenced is flagged so that the self-reference can
401 -- be expanded into a reference to the target object (see exp_aggr).
403 ------------------------------
404 -- Build_Access_Object_Type --
405 ------------------------------
407 function Build_Access_Object_Type (DT : Entity_Id) return Entity_Id is
408 Typ : constant Entity_Id :=
410 (E_Access_Attribute_Type, Current_Scope, Loc, 'A
');
412 Set_Etype (Typ, Typ);
414 Set_Associated_Node_For_Itype (Typ, N);
415 Set_Directly_Designated_Type (Typ, DT);
417 end Build_Access_Object_Type;
419 ----------------------------------
420 -- Build_Access_Subprogram_Type --
421 ----------------------------------
423 procedure Build_Access_Subprogram_Type (P : Node_Id) is
424 Index : Interp_Index;
427 procedure Check_Local_Access (E : Entity_Id);
428 -- Deal with possible access to local subprogram. If we have such
429 -- an access, we set a flag to kill all tracked values on any call
430 -- because this access value may be passed around, and any called
431 -- code might use it to access a local procedure which clobbers a
432 -- tracked value. If the scope is a loop or block, indicate that
433 -- value tracking is disabled for the enclosing subprogram.
435 function Get_Kind (E : Entity_Id) return Entity_Kind;
436 -- Distinguish between access to regular/protected subprograms
438 ------------------------
439 -- Check_Local_Access --
440 ------------------------
442 procedure Check_Local_Access (E : Entity_Id) is
444 if not Is_Library_Level_Entity (E) then
445 Set_Suppress_Value_Tracking_On_Call (Current_Scope);
446 Set_Suppress_Value_Tracking_On_Call
447 (Nearest_Dynamic_Scope (Current_Scope));
449 end Check_Local_Access;
455 function Get_Kind (E : Entity_Id) return Entity_Kind is
457 if Convention (E) = Convention_Protected then
458 return E_Access_Protected_Subprogram_Type;
460 return E_Access_Subprogram_Type;
464 -- Start of processing for Build_Access_Subprogram_Type
467 -- In the case of an access to subprogram, use the name of the
468 -- subprogram itself as the designated type. Type-checking in
469 -- this case compares the signatures of the designated types.
471 -- Note: This fragment of the tree is temporarily malformed
472 -- because the correct tree requires an E_Subprogram_Type entity
473 -- as the designated type. In most cases this designated type is
474 -- later overridden by the semantics with the type imposed by the
475 -- context during the resolution phase. In the specific case of
476 -- the expression Address!(Prim'Unrestricted_Access), used to
477 -- initialize slots of dispatch tables, this work will be done by
478 -- the expander (see Exp_Aggr).
480 -- The reason to temporarily add this kind of node to the tree
481 -- instead of a proper E_Subprogram_Type itype, is the following:
482 -- in case of errors found in the source file we report better
483 -- error messages. For example, instead of generating the
486 -- "expected access to subprogram with profile
487 -- defined at line X"
489 -- we currently generate:
491 -- "expected access to function Z defined at line X"
493 Set_Etype (N, Any_Type);
495 if not Is_Overloaded (P) then
496 Check_Local_Access (Entity (P));
498 if not Is_Intrinsic_Subprogram (Entity (P)) then
499 Acc_Type := Create_Itype (Get_Kind (Entity (P)), N);
500 Set_Is_Public (Acc_Type, False);
501 Set_Etype (Acc_Type, Acc_Type);
502 Set_Convention (Acc_Type, Convention (Entity (P)));
503 Set_Directly_Designated_Type (Acc_Type, Entity (P));
504 Set_Etype (N, Acc_Type);
505 Freeze_Before (N, Acc_Type);
509 Get_First_Interp (P, Index, It);
510 while Present (It.Nam) loop
511 Check_Local_Access (It.Nam);
513 if not Is_Intrinsic_Subprogram (It.Nam) then
514 Acc_Type := Create_Itype (Get_Kind (It.Nam), N);
515 Set_Is_Public (Acc_Type, False);
516 Set_Etype (Acc_Type, Acc_Type);
517 Set_Convention (Acc_Type, Convention (It.Nam));
518 Set_Directly_Designated_Type (Acc_Type, It.Nam);
519 Add_One_Interp (N, Acc_Type, Acc_Type);
520 Freeze_Before (N, Acc_Type);
523 Get_Next_Interp (Index, It);
527 -- Cannot be applied to intrinsic. Looking at the tests above,
528 -- the only way Etype (N) can still be set to Any_Type is if
529 -- Is_Intrinsic_Subprogram was True for some referenced entity.
531 if Etype (N) = Any_Type then
532 Error_Attr_P ("prefix of % attribute cannot be intrinsic");
534 end Build_Access_Subprogram_Type;
536 ----------------------
537 -- OK_Self_Reference --
538 ----------------------
540 function OK_Self_Reference return Boolean is
547 (Nkind (Par) = N_Component_Association
548 or else Nkind (Par) in N_Subexpr)
550 if Nkind_In (Par, N_Aggregate, N_Extension_Aggregate) then
551 if Etype (Par) = Typ then
552 Set_Has_Self_Reference (Par);
560 -- No enclosing aggregate, or not a self-reference
563 end OK_Self_Reference;
565 -- Start of processing for Analyze_Access_Attribute
570 if Nkind (P) = N_Character_Literal then
572 ("prefix of % attribute cannot be enumeration literal");
575 -- Case of access to subprogram
577 if Is_Entity_Name (P)
578 and then Is_Overloadable (Entity (P))
580 if Has_Pragma_Inline_Always (Entity (P)) then
582 ("prefix of % attribute cannot be Inline_Always subprogram");
585 if Aname = Name_Unchecked_Access then
586 Error_Attr ("attribute% cannot be applied to a subprogram", P);
589 -- Issue an error if the prefix denotes an eliminated subprogram
591 Check_For_Eliminated_Subprogram (P, Entity (P));
593 -- Check for obsolescent subprogram reference
595 Check_Obsolescent_2005_Entity (Entity (P), P);
597 -- Build the appropriate subprogram type
599 Build_Access_Subprogram_Type (P);
601 -- For unrestricted access, kill current values, since this
602 -- attribute allows a reference to a local subprogram that
603 -- could modify local variables to be passed out of scope
605 if Aname = Name_Unrestricted_Access then
607 -- Do not kill values on nodes initializing dispatch tables
608 -- slots. The construct Prim_Ptr!(Prim'Unrestricted_Access)
609 -- is currently generated by the expander only for this
610 -- purpose. Done to keep the quality of warnings currently
611 -- generated by the compiler (otherwise any declaration of
612 -- a tagged type cleans constant indications from its scope).
614 if Nkind (Parent (N)) = N_Unchecked_Type_Conversion
615 and then (Etype (Parent (N)) = RTE (RE_Prim_Ptr)
617 Etype (Parent (N)) = RTE (RE_Size_Ptr))
618 and then Is_Dispatching_Operation
619 (Directly_Designated_Type (Etype (N)))
629 -- Component is an operation of a protected type
631 elsif Nkind (P) = N_Selected_Component
632 and then Is_Overloadable (Entity (Selector_Name (P)))
634 if Ekind (Entity (Selector_Name (P))) = E_Entry then
635 Error_Attr_P ("prefix of % attribute must be subprogram");
638 Build_Access_Subprogram_Type (Selector_Name (P));
642 -- Deal with incorrect reference to a type, but note that some
643 -- accesses are allowed: references to the current type instance,
644 -- or in Ada 2005 self-referential pointer in a default-initialized
647 if Is_Entity_Name (P) then
650 -- The reference may appear in an aggregate that has been expanded
651 -- into a loop. Locate scope of type definition, if any.
653 Scop := Current_Scope;
654 while Ekind (Scop) = E_Loop loop
655 Scop := Scope (Scop);
658 if Is_Type (Typ) then
660 -- OK if we are within the scope of a limited type
661 -- let's mark the component as having per object constraint
663 if Is_Anonymous_Tagged_Base (Scop, Typ) then
671 Q : Node_Id := Parent (N);
675 and then Nkind (Q) /= N_Component_Declaration
681 Set_Has_Per_Object_Constraint
682 (Defining_Identifier (Q), True);
686 if Nkind (P) = N_Expanded_Name then
688 ("current instance prefix must be a direct name", P);
691 -- If a current instance attribute appears in a component
692 -- constraint it must appear alone; other contexts (spec-
693 -- expressions, within a task body) are not subject to this
696 if not In_Spec_Expression
697 and then not Has_Completion (Scop)
699 Nkind_In (Parent (N), N_Discriminant_Association,
700 N_Index_Or_Discriminant_Constraint)
703 ("current instance attribute must appear alone", N);
706 if Is_CPP_Class (Root_Type (Typ)) then
708 ("?current instance unsupported for derivations of "
709 & "'C
'P'P types", N);
712 -- OK if we are in initialization procedure for the type
713 -- in question, in which case the reference to the type
714 -- is rewritten as a reference to the current object.
716 elsif Ekind (Scop) = E_Procedure
717 and then Is_Init_Proc (Scop)
718 and then Etype (First_Formal (Scop)) = Typ
721 Make_Attribute_Reference (Loc,
722 Prefix => Make_Identifier (Loc, Name_uInit),
723 Attribute_Name => Name_Unrestricted_Access));
727 -- OK if a task type, this test needs sharpening up ???
729 elsif Is_Task_Type (Typ) then
732 -- OK if self-reference in an aggregate in Ada 2005, and
733 -- the reference comes from a copied default expression.
735 -- Note that we check legality of self-reference even if the
736 -- expression comes from source, e.g. when a single component
737 -- association in an aggregate has a box association.
739 elsif Ada_Version >= Ada_2005
740 and then OK_Self_Reference
744 -- OK if reference to current instance of a protected object
746 elsif Is_Protected_Self_Reference (P) then
749 -- Otherwise we have an error case
752 Error_Attr ("% attribute cannot be applied to type", P);
758 -- If we fall through, we have a normal access to object case.
759 -- Unrestricted_Access is legal wherever an allocator would be
760 -- legal, so its Etype is set to E_Allocator. The expected type
761 -- of the other attributes is a general access type, and therefore
762 -- we label them with E_Access_Attribute_Type.
764 if not Is_Overloaded (P) then
765 Acc_Type := Build_Access_Object_Type (P_Type);
766 Set_Etype (N, Acc_Type);
769 Index : Interp_Index;
772 Set_Etype (N, Any_Type);
773 Get_First_Interp (P, Index, It);
774 while Present (It.Typ) loop
775 Acc_Type := Build_Access_Object_Type (It.Typ);
776 Add_One_Interp (N, Acc_Type, Acc_Type);
777 Get_Next_Interp (Index, It);
782 -- Special cases when we can find a prefix that is an entity name
791 if Is_Entity_Name (PP) then
794 -- If we have an access to an object, and the attribute
795 -- comes from source, then set the object as potentially
796 -- source modified. We do this because the resulting access
797 -- pointer can be used to modify the variable, and we might
798 -- not detect this, leading to some junk warnings.
800 Set_Never_Set_In_Source (Ent, False);
802 -- Mark entity as address taken, and kill current values
804 Set_Address_Taken (Ent);
805 Kill_Current_Values (Ent);
808 elsif Nkind_In (PP, N_Selected_Component,
819 -- Check for aliased view unless unrestricted case. We allow a
820 -- nonaliased prefix when within an instance because the prefix may
821 -- have been a tagged formal object, which is defined to be aliased
822 -- even when the actual might not be (other instance cases will have
823 -- been caught in the generic). Similarly, within an inlined body we
824 -- know that the attribute is legal in the original subprogram, and
825 -- therefore legal in the expansion.
827 if Aname /= Name_Unrestricted_Access
828 and then not Is_Aliased_View (P)
829 and then not In_Instance
830 and then not In_Inlined_Body
832 Error_Attr_P ("prefix of % attribute must be aliased");
834 end Analyze_Access_Attribute;
836 ---------------------------------
837 -- Bad_Attribute_For_Predicate --
838 ---------------------------------
840 procedure Bad_Attribute_For_Predicate is
842 if Comes_From_Source (N) then
843 Error_Msg_Name_1 := Aname;
844 Bad_Predicated_Subtype_Use
845 ("type& has predicates, attribute % not allowed", N, P_Type);
847 end Bad_Attribute_For_Predicate;
849 --------------------------------
850 -- Check_Array_Or_Scalar_Type --
851 --------------------------------
853 procedure Check_Array_Or_Scalar_Type is
857 -- Dimension number for array attributes
860 -- Case of string literal or string literal subtype. These cases
861 -- cannot arise from legal Ada code, but the expander is allowed
862 -- to generate them. They require special handling because string
863 -- literal subtypes do not have standard bounds (the whole idea
864 -- of these subtypes is to avoid having to generate the bounds)
866 if Ekind (P_Type) = E_String_Literal_Subtype then
867 Set_Etype (N, Etype (First_Index (P_Base_Type)));
872 elsif Is_Scalar_Type (P_Type) then
876 Error_Attr ("invalid argument in % attribute", E1);
878 Set_Etype (N, P_Base_Type);
882 -- The following is a special test to allow 'First to apply to
883 -- private scalar types if the attribute comes from generated
884 -- code. This occurs in the case of Normalize_Scalars code.
886 elsif Is_Private_Type
(P_Type
)
887 and then Present
(Full_View
(P_Type
))
888 and then Is_Scalar_Type
(Full_View
(P_Type
))
889 and then not Comes_From_Source
(N
)
891 Set_Etype
(N
, Implementation_Base_Type
(P_Type
));
893 -- Array types other than string literal subtypes handled above
898 -- We know prefix is an array type, or the name of an array
899 -- object, and that the expression, if present, is static
900 -- and within the range of the dimensions of the type.
902 pragma Assert
(Is_Array_Type
(P_Type
));
903 Index
:= First_Index
(P_Base_Type
);
907 -- First dimension assumed
909 Set_Etype
(N
, Base_Type
(Etype
(Index
)));
912 D
:= UI_To_Int
(Intval
(E1
));
914 for J
in 1 .. D
- 1 loop
918 Set_Etype
(N
, Base_Type
(Etype
(Index
)));
919 Set_Etype
(E1
, Standard_Integer
);
922 end Check_Array_Or_Scalar_Type
;
924 ----------------------
925 -- Check_Array_Type --
926 ----------------------
928 procedure Check_Array_Type
is
930 -- Dimension number for array attributes
933 -- If the type is a string literal type, then this must be generated
934 -- internally, and no further check is required on its legality.
936 if Ekind
(P_Type
) = E_String_Literal_Subtype
then
939 -- If the type is a composite, it is an illegal aggregate, no point
942 elsif P_Type
= Any_Composite
then
946 -- Normal case of array type or subtype
948 Check_Either_E0_Or_E1
;
951 if Is_Array_Type
(P_Type
) then
952 if not Is_Constrained
(P_Type
)
953 and then Is_Entity_Name
(P
)
954 and then Is_Type
(Entity
(P
))
956 -- Note: we do not call Error_Attr here, since we prefer to
957 -- continue, using the relevant index type of the array,
958 -- even though it is unconstrained. This gives better error
959 -- recovery behavior.
961 Error_Msg_Name_1
:= Aname
;
963 ("prefix for % attribute must be constrained array", P
);
966 D
:= Number_Dimensions
(P_Type
);
969 if Is_Private_Type
(P_Type
) then
970 Error_Attr_P
("prefix for % attribute may not be private type");
972 elsif Is_Access_Type
(P_Type
)
973 and then Is_Array_Type
(Designated_Type
(P_Type
))
974 and then Is_Entity_Name
(P
)
975 and then Is_Type
(Entity
(P
))
977 Error_Attr_P
("prefix of % attribute cannot be access type");
979 elsif Attr_Id
= Attribute_First
981 Attr_Id
= Attribute_Last
983 Error_Attr
("invalid prefix for % attribute", P
);
986 Error_Attr_P
("prefix for % attribute must be array");
991 Resolve
(E1
, Any_Integer
);
992 Set_Etype
(E1
, Standard_Integer
);
994 if not Is_Static_Expression
(E1
)
995 or else Raises_Constraint_Error
(E1
)
998 ("expression for dimension must be static!", E1
);
1001 elsif UI_To_Int
(Expr_Value
(E1
)) > D
1002 or else UI_To_Int
(Expr_Value
(E1
)) < 1
1004 Error_Attr
("invalid dimension number for array type", E1
);
1008 if (Style_Check
and Style_Check_Array_Attribute_Index
)
1009 and then Comes_From_Source
(N
)
1011 Style
.Check_Array_Attribute_Index
(N
, E1
, D
);
1013 end Check_Array_Type
;
1015 -------------------------
1016 -- Check_Asm_Attribute --
1017 -------------------------
1019 procedure Check_Asm_Attribute
is
1024 -- Check first argument is static string expression
1026 Analyze_And_Resolve
(E1
, Standard_String
);
1028 if Etype
(E1
) = Any_Type
then
1031 elsif not Is_OK_Static_Expression
(E1
) then
1032 Flag_Non_Static_Expr
1033 ("constraint argument must be static string expression!", E1
);
1037 -- Check second argument is right type
1039 Analyze_And_Resolve
(E2
, Entity
(P
));
1041 -- Note: that is all we need to do, we don't need to check
1042 -- that it appears in a correct context. The Ada type system
1043 -- will do that for us.
1045 end Check_Asm_Attribute
;
1047 ---------------------
1048 -- Check_Component --
1049 ---------------------
1051 procedure Check_Component
is
1055 if Nkind
(P
) /= N_Selected_Component
1057 (Ekind
(Entity
(Selector_Name
(P
))) /= E_Component
1059 Ekind
(Entity
(Selector_Name
(P
))) /= E_Discriminant
)
1061 Error_Attr_P
("prefix for % attribute must be selected component");
1063 end Check_Component
;
1065 ------------------------------------
1066 -- Check_Decimal_Fixed_Point_Type --
1067 ------------------------------------
1069 procedure Check_Decimal_Fixed_Point_Type
is
1073 if not Is_Decimal_Fixed_Point_Type
(P_Type
) then
1074 Error_Attr_P
("prefix of % attribute must be decimal type");
1076 end Check_Decimal_Fixed_Point_Type
;
1078 -----------------------
1079 -- Check_Dereference --
1080 -----------------------
1082 procedure Check_Dereference
is
1085 -- Case of a subtype mark
1087 if Is_Entity_Name
(P
)
1088 and then Is_Type
(Entity
(P
))
1093 -- Case of an expression
1097 if Is_Access_Type
(P_Type
) then
1099 -- If there is an implicit dereference, then we must freeze
1100 -- the designated type of the access type, since the type of
1101 -- the referenced array is this type (see AI95-00106).
1103 -- As done elsewhere, freezing must not happen when pre-analyzing
1104 -- a pre- or postcondition or a default value for an object or
1105 -- for a formal parameter.
1107 if not In_Spec_Expression
then
1108 Freeze_Before
(N
, Designated_Type
(P_Type
));
1112 Make_Explicit_Dereference
(Sloc
(P
),
1113 Prefix
=> Relocate_Node
(P
)));
1115 Analyze_And_Resolve
(P
);
1116 P_Type
:= Etype
(P
);
1118 if P_Type
= Any_Type
then
1119 raise Bad_Attribute
;
1122 P_Base_Type
:= Base_Type
(P_Type
);
1124 end Check_Dereference
;
1126 -------------------------
1127 -- Check_Discrete_Type --
1128 -------------------------
1130 procedure Check_Discrete_Type
is
1134 if not Is_Discrete_Type
(P_Type
) then
1135 Error_Attr_P
("prefix of % attribute must be discrete type");
1137 end Check_Discrete_Type
;
1143 procedure Check_E0
is
1145 if Present
(E1
) then
1146 Unexpected_Argument
(E1
);
1154 procedure Check_E1
is
1156 Check_Either_E0_Or_E1
;
1160 -- Special-case attributes that are functions and that appear as
1161 -- the prefix of another attribute. Error is posted on parent.
1163 if Nkind
(Parent
(N
)) = N_Attribute_Reference
1164 and then (Attribute_Name
(Parent
(N
)) = Name_Address
1166 Attribute_Name
(Parent
(N
)) = Name_Code_Address
1168 Attribute_Name
(Parent
(N
)) = Name_Access
)
1170 Error_Msg_Name_1
:= Attribute_Name
(Parent
(N
));
1171 Error_Msg_N
("illegal prefix for % attribute", Parent
(N
));
1172 Set_Etype
(Parent
(N
), Any_Type
);
1173 Set_Entity
(Parent
(N
), Any_Type
);
1174 raise Bad_Attribute
;
1177 Error_Attr
("missing argument for % attribute", N
);
1186 procedure Check_E2
is
1189 Error_Attr
("missing arguments for % attribute (2 required)", N
);
1191 Error_Attr
("missing argument for % attribute (2 required)", N
);
1195 ---------------------------
1196 -- Check_Either_E0_Or_E1 --
1197 ---------------------------
1199 procedure Check_Either_E0_Or_E1
is
1201 if Present
(E2
) then
1202 Unexpected_Argument
(E2
);
1204 end Check_Either_E0_Or_E1
;
1206 ----------------------
1207 -- Check_Enum_Image --
1208 ----------------------
1210 procedure Check_Enum_Image
is
1213 if Is_Enumeration_Type
(P_Base_Type
) then
1214 Lit
:= First_Literal
(P_Base_Type
);
1215 while Present
(Lit
) loop
1216 Set_Referenced
(Lit
);
1220 end Check_Enum_Image
;
1222 ----------------------------
1223 -- Check_Fixed_Point_Type --
1224 ----------------------------
1226 procedure Check_Fixed_Point_Type
is
1230 if not Is_Fixed_Point_Type
(P_Type
) then
1231 Error_Attr_P
("prefix of % attribute must be fixed point type");
1233 end Check_Fixed_Point_Type
;
1235 ------------------------------
1236 -- Check_Fixed_Point_Type_0 --
1237 ------------------------------
1239 procedure Check_Fixed_Point_Type_0
is
1241 Check_Fixed_Point_Type
;
1243 end Check_Fixed_Point_Type_0
;
1245 -------------------------------
1246 -- Check_Floating_Point_Type --
1247 -------------------------------
1249 procedure Check_Floating_Point_Type
is
1253 if not Is_Floating_Point_Type
(P_Type
) then
1254 Error_Attr_P
("prefix of % attribute must be float type");
1256 end Check_Floating_Point_Type
;
1258 ---------------------------------
1259 -- Check_Floating_Point_Type_0 --
1260 ---------------------------------
1262 procedure Check_Floating_Point_Type_0
is
1264 Check_Floating_Point_Type
;
1266 end Check_Floating_Point_Type_0
;
1268 ---------------------------------
1269 -- Check_Floating_Point_Type_1 --
1270 ---------------------------------
1272 procedure Check_Floating_Point_Type_1
is
1274 Check_Floating_Point_Type
;
1276 end Check_Floating_Point_Type_1
;
1278 ---------------------------------
1279 -- Check_Floating_Point_Type_2 --
1280 ---------------------------------
1282 procedure Check_Floating_Point_Type_2
is
1284 Check_Floating_Point_Type
;
1286 end Check_Floating_Point_Type_2
;
1288 ------------------------
1289 -- Check_Integer_Type --
1290 ------------------------
1292 procedure Check_Integer_Type
is
1296 if not Is_Integer_Type
(P_Type
) then
1297 Error_Attr_P
("prefix of % attribute must be integer type");
1299 end Check_Integer_Type
;
1301 ------------------------
1302 -- Check_Library_Unit --
1303 ------------------------
1305 procedure Check_Library_Unit
is
1307 if not Is_Compilation_Unit
(Entity
(P
)) then
1308 Error_Attr_P
("prefix of % attribute must be library unit");
1310 end Check_Library_Unit
;
1312 --------------------------------
1313 -- Check_Modular_Integer_Type --
1314 --------------------------------
1316 procedure Check_Modular_Integer_Type
is
1320 if not Is_Modular_Integer_Type
(P_Type
) then
1322 ("prefix of % attribute must be modular integer type");
1324 end Check_Modular_Integer_Type
;
1326 ------------------------
1327 -- Check_Not_CPP_Type --
1328 ------------------------
1330 procedure Check_Not_CPP_Type
is
1332 if Is_Tagged_Type
(Etype
(P
))
1333 and then Convention
(Etype
(P
)) = Convention_CPP
1334 and then Is_CPP_Class
(Root_Type
(Etype
(P
)))
1337 ("invalid use of % attribute with 'C'P'P tagged type");
1339 end Check_Not_CPP_Type
;
1341 -------------------------------
1342 -- Check_Not_Incomplete_Type --
1343 -------------------------------
1345 procedure Check_Not_Incomplete_Type
is
1350 -- Ada 2005 (AI-50217, AI-326): If the prefix is an explicit
1351 -- dereference we have to check wrong uses of incomplete types
1352 -- (other wrong uses are checked at their freezing point).
1354 -- Example 1: Limited-with
1356 -- limited with Pkg;
1358 -- type Acc is access Pkg.T;
1360 -- S : Integer := X.all'Size; -- ERROR
1363 -- Example 2: Tagged incomplete
1365 -- type T is tagged;
1366 -- type Acc is access all T;
1368 -- S : constant Integer := X.all'Size; -- ERROR
1369 -- procedure Q (Obj : Integer := X.all'Alignment); -- ERROR
1371 if Ada_Version
>= Ada_2005
1372 and then Nkind
(P
) = N_Explicit_Dereference
1375 while Nkind
(E
) = N_Explicit_Dereference
loop
1381 if From_With_Type
(Typ
) then
1383 ("prefix of % attribute cannot be an incomplete type");
1386 if Is_Access_Type
(Typ
) then
1387 Typ
:= Directly_Designated_Type
(Typ
);
1390 if Is_Class_Wide_Type
(Typ
) then
1391 Typ
:= Root_Type
(Typ
);
1394 -- A legal use of a shadow entity occurs only when the unit
1395 -- where the non-limited view resides is imported via a regular
1396 -- with clause in the current body. Such references to shadow
1397 -- entities may occur in subprogram formals.
1399 if Is_Incomplete_Type
(Typ
)
1400 and then From_With_Type
(Typ
)
1401 and then Present
(Non_Limited_View
(Typ
))
1402 and then Is_Legal_Shadow_Entity_In_Body
(Typ
)
1404 Typ
:= Non_Limited_View
(Typ
);
1407 if Ekind
(Typ
) = E_Incomplete_Type
1408 and then No
(Full_View
(Typ
))
1411 ("prefix of % attribute cannot be an incomplete type");
1416 if not Is_Entity_Name
(P
)
1417 or else not Is_Type
(Entity
(P
))
1418 or else In_Spec_Expression
1422 Check_Fully_Declared
(P_Type
, P
);
1424 end Check_Not_Incomplete_Type
;
1426 ----------------------------
1427 -- Check_Object_Reference --
1428 ----------------------------
1430 procedure Check_Object_Reference
(P
: Node_Id
) is
1434 -- If we need an object, and we have a prefix that is the name of
1435 -- a function entity, convert it into a function call.
1437 if Is_Entity_Name
(P
)
1438 and then Ekind
(Entity
(P
)) = E_Function
1440 Rtyp
:= Etype
(Entity
(P
));
1443 Make_Function_Call
(Sloc
(P
),
1444 Name
=> Relocate_Node
(P
)));
1446 Analyze_And_Resolve
(P
, Rtyp
);
1448 -- Otherwise we must have an object reference
1450 elsif not Is_Object_Reference
(P
) then
1451 Error_Attr_P
("prefix of % attribute must be object");
1453 end Check_Object_Reference
;
1455 ----------------------------
1456 -- Check_PolyORB_Attribute --
1457 ----------------------------
1459 procedure Check_PolyORB_Attribute
is
1461 Validate_Non_Static_Attribute_Function_Call
;
1466 if Get_PCS_Name
/= Name_PolyORB_DSA
then
1468 ("attribute% requires the 'Poly'O'R'B 'P'C'S", N
);
1470 end Check_PolyORB_Attribute
;
1472 ------------------------
1473 -- Check_Program_Unit --
1474 ------------------------
1476 procedure Check_Program_Unit
is
1478 if Is_Entity_Name
(P
) then
1480 K
: constant Entity_Kind
:= Ekind
(Entity
(P
));
1481 T
: constant Entity_Id
:= Etype
(Entity
(P
));
1484 if K
in Subprogram_Kind
1485 or else K
in Task_Kind
1486 or else K
in Protected_Kind
1487 or else K
= E_Package
1488 or else K
in Generic_Unit_Kind
1489 or else (K
= E_Variable
1493 Is_Protected_Type
(T
)))
1500 Error_Attr_P
("prefix of % attribute must be program unit");
1501 end Check_Program_Unit
;
1503 ---------------------
1504 -- Check_Real_Type --
1505 ---------------------
1507 procedure Check_Real_Type
is
1511 if not Is_Real_Type
(P_Type
) then
1512 Error_Attr_P
("prefix of % attribute must be real type");
1514 end Check_Real_Type
;
1516 -----------------------
1517 -- Check_Scalar_Type --
1518 -----------------------
1520 procedure Check_Scalar_Type
is
1524 if not Is_Scalar_Type
(P_Type
) then
1525 Error_Attr_P
("prefix of % attribute must be scalar type");
1527 end Check_Scalar_Type
;
1529 ---------------------------
1530 -- Check_Standard_Prefix --
1531 ---------------------------
1533 procedure Check_Standard_Prefix
is
1537 if Nkind
(P
) /= N_Identifier
1538 or else Chars
(P
) /= Name_Standard
1540 Error_Attr
("only allowed prefix for % attribute is Standard", P
);
1542 end Check_Standard_Prefix
;
1544 ----------------------------
1545 -- Check_Stream_Attribute --
1546 ----------------------------
1548 procedure Check_Stream_Attribute
(Nam
: TSS_Name_Type
) is
1552 In_Shared_Var_Procs
: Boolean;
1553 -- True when compiling the body of System.Shared_Storage.
1554 -- Shared_Var_Procs. For this runtime package (always compiled in
1555 -- GNAT mode), we allow stream attributes references for limited
1556 -- types for the case where shared passive objects are implemented
1557 -- using stream attributes, which is the default in GNAT's persistent
1558 -- storage implementation.
1561 Validate_Non_Static_Attribute_Function_Call
;
1563 -- With the exception of 'Input, Stream attributes are procedures,
1564 -- and can only appear at the position of procedure calls. We check
1565 -- for this here, before they are rewritten, to give a more precise
1568 if Nam
= TSS_Stream_Input
then
1571 elsif Is_List_Member
(N
)
1572 and then not Nkind_In
(Parent
(N
), N_Procedure_Call_Statement
,
1579 ("invalid context for attribute%, which is a procedure", N
);
1583 Btyp
:= Implementation_Base_Type
(P_Type
);
1585 -- Stream attributes not allowed on limited types unless the
1586 -- attribute reference was generated by the expander (in which
1587 -- case the underlying type will be used, as described in Sinfo),
1588 -- or the attribute was specified explicitly for the type itself
1589 -- or one of its ancestors (taking visibility rules into account if
1590 -- in Ada 2005 mode), or a pragma Stream_Convert applies to Btyp
1591 -- (with no visibility restriction).
1594 Gen_Body
: constant Node_Id
:= Enclosing_Generic_Body
(N
);
1596 if Present
(Gen_Body
) then
1597 In_Shared_Var_Procs
:=
1598 Is_RTE
(Corresponding_Spec
(Gen_Body
), RE_Shared_Var_Procs
);
1600 In_Shared_Var_Procs
:= False;
1604 if (Comes_From_Source
(N
)
1605 and then not (In_Shared_Var_Procs
or In_Instance
))
1606 and then not Stream_Attribute_Available
(P_Type
, Nam
)
1607 and then not Has_Rep_Pragma
(Btyp
, Name_Stream_Convert
)
1609 Error_Msg_Name_1
:= Aname
;
1611 if Is_Limited_Type
(P_Type
) then
1613 ("limited type& has no% attribute", P
, P_Type
);
1614 Explain_Limited_Type
(P_Type
, P
);
1617 ("attribute% for type& is not available", P
, P_Type
);
1621 -- Check restriction violations
1623 -- First check the No_Streams restriction, which prohibits the use
1624 -- of explicit stream attributes in the source program. We do not
1625 -- prevent the occurrence of stream attributes in generated code,
1626 -- for instance those generated implicitly for dispatching purposes.
1628 if Comes_From_Source
(N
) then
1629 Check_Restriction
(No_Streams
, P
);
1632 -- Check special case of Exception_Id and Exception_Occurrence which
1633 -- are not allowed for restriction No_Exception_Registration.
1635 if Is_RTE
(P_Type
, RE_Exception_Id
)
1637 Is_RTE
(P_Type
, RE_Exception_Occurrence
)
1639 Check_Restriction
(No_Exception_Registration
, P
);
1642 -- Here we must check that the first argument is an access type
1643 -- that is compatible with Ada.Streams.Root_Stream_Type'Class.
1645 Analyze_And_Resolve
(E1
);
1648 -- Note: the double call to Root_Type here is needed because the
1649 -- root type of a class-wide type is the corresponding type (e.g.
1650 -- X for X'Class, and we really want to go to the root.)
1652 if not Is_Access_Type
(Etyp
)
1653 or else Root_Type
(Root_Type
(Designated_Type
(Etyp
))) /=
1654 RTE
(RE_Root_Stream_Type
)
1657 ("expected access to Ada.Streams.Root_Stream_Type''Class", E1
);
1660 -- Check that the second argument is of the right type if there is
1661 -- one (the Input attribute has only one argument so this is skipped)
1663 if Present
(E2
) then
1666 if Nam
= TSS_Stream_Read
1667 and then not Is_OK_Variable_For_Out_Formal
(E2
)
1670 ("second argument of % attribute must be a variable", E2
);
1673 Resolve
(E2
, P_Type
);
1677 end Check_Stream_Attribute
;
1679 -----------------------
1680 -- Check_Task_Prefix --
1681 -----------------------
1683 procedure Check_Task_Prefix
is
1687 -- Ada 2005 (AI-345): Attribute 'Terminated can be applied to
1688 -- task interface class-wide types.
1690 if Is_Task_Type
(Etype
(P
))
1691 or else (Is_Access_Type
(Etype
(P
))
1692 and then Is_Task_Type
(Designated_Type
(Etype
(P
))))
1693 or else (Ada_Version
>= Ada_2005
1694 and then Ekind
(Etype
(P
)) = E_Class_Wide_Type
1695 and then Is_Interface
(Etype
(P
))
1696 and then Is_Task_Interface
(Etype
(P
)))
1701 if Ada_Version
>= Ada_2005
then
1703 ("prefix of % attribute must be a task or a task " &
1704 "interface class-wide object");
1707 Error_Attr_P
("prefix of % attribute must be a task");
1710 end Check_Task_Prefix
;
1716 -- The possibilities are an entity name denoting a type, or an
1717 -- attribute reference that denotes a type (Base or Class). If
1718 -- the type is incomplete, replace it with its full view.
1720 procedure Check_Type
is
1722 if not Is_Entity_Name
(P
)
1723 or else not Is_Type
(Entity
(P
))
1725 Error_Attr_P
("prefix of % attribute must be a type");
1727 elsif Is_Protected_Self_Reference
(P
) then
1729 ("prefix of % attribute denotes current instance "
1730 & "(RM 9.4(21/2))");
1732 elsif Ekind
(Entity
(P
)) = E_Incomplete_Type
1733 and then Present
(Full_View
(Entity
(P
)))
1735 P_Type
:= Full_View
(Entity
(P
));
1736 Set_Entity
(P
, P_Type
);
1740 ---------------------
1741 -- Check_Unit_Name --
1742 ---------------------
1744 procedure Check_Unit_Name
(Nod
: Node_Id
) is
1746 if Nkind
(Nod
) = N_Identifier
then
1749 elsif Nkind
(Nod
) = N_Selected_Component
then
1750 Check_Unit_Name
(Prefix
(Nod
));
1752 if Nkind
(Selector_Name
(Nod
)) = N_Identifier
then
1757 Error_Attr
("argument for % attribute must be unit name", P
);
1758 end Check_Unit_Name
;
1764 procedure Error_Attr
is
1766 Set_Etype
(N
, Any_Type
);
1767 Set_Entity
(N
, Any_Type
);
1768 raise Bad_Attribute
;
1771 procedure Error_Attr
(Msg
: String; Error_Node
: Node_Id
) is
1773 Error_Msg_Name_1
:= Aname
;
1774 Error_Msg_N
(Msg
, Error_Node
);
1782 procedure Error_Attr_P
(Msg
: String) is
1784 Error_Msg_Name_1
:= Aname
;
1785 Error_Msg_F
(Msg
, P
);
1789 ----------------------------
1790 -- Legal_Formal_Attribute --
1791 ----------------------------
1793 procedure Legal_Formal_Attribute
is
1797 if not Is_Entity_Name
(P
)
1798 or else not Is_Type
(Entity
(P
))
1800 Error_Attr_P
("prefix of % attribute must be generic type");
1802 elsif Is_Generic_Actual_Type
(Entity
(P
))
1804 or else In_Inlined_Body
1808 elsif Is_Generic_Type
(Entity
(P
)) then
1809 if not Is_Indefinite_Subtype
(Entity
(P
)) then
1811 ("prefix of % attribute must be indefinite generic type");
1816 ("prefix of % attribute must be indefinite generic type");
1819 Set_Etype
(N
, Standard_Boolean
);
1820 end Legal_Formal_Attribute
;
1822 ------------------------
1823 -- Standard_Attribute --
1824 ------------------------
1826 procedure Standard_Attribute
(Val
: Int
) is
1828 Check_Standard_Prefix
;
1829 Rewrite
(N
, Make_Integer_Literal
(Loc
, Val
));
1831 end Standard_Attribute
;
1833 -------------------------
1834 -- Unexpected Argument --
1835 -------------------------
1837 procedure Unexpected_Argument
(En
: Node_Id
) is
1839 Error_Attr
("unexpected argument for % attribute", En
);
1840 end Unexpected_Argument
;
1842 -------------------------------------------------
1843 -- Validate_Non_Static_Attribute_Function_Call --
1844 -------------------------------------------------
1846 -- This function should be moved to Sem_Dist ???
1848 procedure Validate_Non_Static_Attribute_Function_Call
is
1850 if In_Preelaborated_Unit
1851 and then not In_Subprogram_Or_Concurrent_Unit
1853 Flag_Non_Static_Expr
1854 ("non-static function call in preelaborated unit!", N
);
1856 end Validate_Non_Static_Attribute_Function_Call
;
1858 -----------------------------------------------
1859 -- Start of Processing for Analyze_Attribute --
1860 -----------------------------------------------
1863 -- Immediate return if unrecognized attribute (already diagnosed
1864 -- by parser, so there is nothing more that we need to do)
1866 if not Is_Attribute_Name
(Aname
) then
1867 raise Bad_Attribute
;
1870 -- Deal with Ada 83 issues
1872 if Comes_From_Source
(N
) then
1873 if not Attribute_83
(Attr_Id
) then
1874 if Ada_Version
= Ada_83
and then Comes_From_Source
(N
) then
1875 Error_Msg_Name_1
:= Aname
;
1876 Error_Msg_N
("(Ada 83) attribute% is not standard?", N
);
1879 if Attribute_Impl_Def
(Attr_Id
) then
1880 Check_Restriction
(No_Implementation_Attributes
, N
);
1885 -- Deal with Ada 2005 issues
1887 if Attribute_05
(Attr_Id
) and then Ada_Version
<= Ada_95
then
1888 Check_Restriction
(No_Implementation_Attributes
, N
);
1891 -- Remote access to subprogram type access attribute reference needs
1892 -- unanalyzed copy for tree transformation. The analyzed copy is used
1893 -- for its semantic information (whether prefix is a remote subprogram
1894 -- name), the unanalyzed copy is used to construct new subtree rooted
1895 -- with N_Aggregate which represents a fat pointer aggregate.
1897 if Aname
= Name_Access
then
1898 Discard_Node
(Copy_Separate_Tree
(N
));
1901 -- Analyze prefix and exit if error in analysis. If the prefix is an
1902 -- incomplete type, use full view if available. Note that there are
1903 -- some attributes for which we do not analyze the prefix, since the
1904 -- prefix is not a normal name.
1906 if Aname
/= Name_Elab_Body
1908 Aname
/= Name_Elab_Spec
1910 Aname
/= Name_UET_Address
1912 Aname
/= Name_Enabled
1915 P_Type
:= Etype
(P
);
1917 if Is_Entity_Name
(P
)
1918 and then Present
(Entity
(P
))
1919 and then Is_Type
(Entity
(P
))
1921 if Ekind
(Entity
(P
)) = E_Incomplete_Type
then
1922 P_Type
:= Get_Full_View
(P_Type
);
1923 Set_Entity
(P
, P_Type
);
1924 Set_Etype
(P
, P_Type
);
1926 elsif Entity
(P
) = Current_Scope
1927 and then Is_Record_Type
(Entity
(P
))
1929 -- Use of current instance within the type. Verify that if the
1930 -- attribute appears within a constraint, it yields an access
1931 -- type, other uses are illegal.
1939 and then Nkind
(Parent
(Par
)) /= N_Component_Definition
1941 Par
:= Parent
(Par
);
1945 and then Nkind
(Par
) = N_Subtype_Indication
1947 if Attr_Id
/= Attribute_Access
1948 and then Attr_Id
/= Attribute_Unchecked_Access
1949 and then Attr_Id
/= Attribute_Unrestricted_Access
1952 ("in a constraint the current instance can only"
1953 & " be used with an access attribute", N
);
1960 if P_Type
= Any_Type
then
1961 raise Bad_Attribute
;
1964 P_Base_Type
:= Base_Type
(P_Type
);
1967 -- Analyze expressions that may be present, exiting if an error occurs
1974 E1
:= First
(Exprs
);
1977 -- Check for missing/bad expression (result of previous error)
1979 if No
(E1
) or else Etype
(E1
) = Any_Type
then
1980 raise Bad_Attribute
;
1985 if Present
(E2
) then
1988 if Etype
(E2
) = Any_Type
then
1989 raise Bad_Attribute
;
1992 if Present
(Next
(E2
)) then
1993 Unexpected_Argument
(Next
(E2
));
1998 -- Ada 2005 (AI-345): Ensure that the compiler gives exactly the current
1999 -- output compiling in Ada 95 mode for the case of ambiguous prefixes.
2001 if Ada_Version
< Ada_2005
2002 and then Is_Overloaded
(P
)
2003 and then Aname
/= Name_Access
2004 and then Aname
/= Name_Address
2005 and then Aname
/= Name_Code_Address
2006 and then Aname
/= Name_Count
2007 and then Aname
/= Name_Result
2008 and then Aname
/= Name_Unchecked_Access
2010 Error_Attr
("ambiguous prefix for % attribute", P
);
2012 elsif Ada_Version
>= Ada_2005
2013 and then Is_Overloaded
(P
)
2014 and then Aname
/= Name_Access
2015 and then Aname
/= Name_Address
2016 and then Aname
/= Name_Code_Address
2017 and then Aname
/= Name_Result
2018 and then Aname
/= Name_Unchecked_Access
2020 -- Ada 2005 (AI-345): Since protected and task types have primitive
2021 -- entry wrappers, the attributes Count, Caller and AST_Entry require
2024 if Ada_Version
>= Ada_2005
2025 and then (Aname
= Name_Count
2026 or else Aname
= Name_Caller
2027 or else Aname
= Name_AST_Entry
)
2030 Count
: Natural := 0;
2035 Get_First_Interp
(P
, I
, It
);
2036 while Present
(It
.Nam
) loop
2037 if Comes_From_Source
(It
.Nam
) then
2043 Get_Next_Interp
(I
, It
);
2047 Error_Attr
("ambiguous prefix for % attribute", P
);
2049 Set_Is_Overloaded
(P
, False);
2054 Error_Attr
("ambiguous prefix for % attribute", P
);
2058 -- Remaining processing depends on attribute
2066 when Attribute_Abort_Signal
=>
2067 Check_Standard_Prefix
;
2069 New_Reference_To
(Stand
.Abort_Signal
, Loc
));
2076 when Attribute_Access
=>
2077 Analyze_Access_Attribute
;
2083 when Attribute_Address
=>
2086 -- Check for some junk cases, where we have to allow the address
2087 -- attribute but it does not make much sense, so at least for now
2088 -- just replace with Null_Address.
2090 -- We also do this if the prefix is a reference to the AST_Entry
2091 -- attribute. If expansion is active, the attribute will be
2092 -- replaced by a function call, and address will work fine and
2093 -- get the proper value, but if expansion is not active, then
2094 -- the check here allows proper semantic analysis of the reference.
2096 -- An Address attribute created by expansion is legal even when it
2097 -- applies to other entity-denoting expressions.
2099 if Is_Protected_Self_Reference
(P
) then
2101 -- Address attribute on a protected object self reference is legal
2105 elsif Is_Entity_Name
(P
) then
2107 Ent
: constant Entity_Id
:= Entity
(P
);
2110 if Is_Subprogram
(Ent
) then
2111 Set_Address_Taken
(Ent
);
2112 Kill_Current_Values
(Ent
);
2114 -- An Address attribute is accepted when generated by the
2115 -- compiler for dispatching operation, and an error is
2116 -- issued once the subprogram is frozen (to avoid confusing
2117 -- errors about implicit uses of Address in the dispatch
2118 -- table initialization).
2120 if Has_Pragma_Inline_Always
(Entity
(P
))
2121 and then Comes_From_Source
(P
)
2124 ("prefix of % attribute cannot be Inline_Always" &
2127 -- It is illegal to apply 'Address to an intrinsic
2128 -- subprogram. This is now formalized in AI05-0095.
2129 -- In an instance, an attempt to obtain 'Address of an
2130 -- intrinsic subprogram (e.g the renaming of a predefined
2131 -- operator that is an actual) raises Program_Error.
2133 elsif Convention
(Ent
) = Convention_Intrinsic
then
2136 Make_Raise_Program_Error
(Loc
,
2137 Reason
=> PE_Address_Of_Intrinsic
));
2141 ("cannot take Address of intrinsic subprogram", N
);
2144 -- Issue an error if prefix denotes an eliminated subprogram
2147 Check_For_Eliminated_Subprogram
(P
, Ent
);
2150 elsif Is_Object
(Ent
)
2151 or else Ekind
(Ent
) = E_Label
2153 Set_Address_Taken
(Ent
);
2155 -- If we have an address of an object, and the attribute
2156 -- comes from source, then set the object as potentially
2157 -- source modified. We do this because the resulting address
2158 -- can potentially be used to modify the variable and we
2159 -- might not detect this, leading to some junk warnings.
2161 Set_Never_Set_In_Source
(Ent
, False);
2163 elsif (Is_Concurrent_Type
(Etype
(Ent
))
2164 and then Etype
(Ent
) = Base_Type
(Ent
))
2165 or else Ekind
(Ent
) = E_Package
2166 or else Is_Generic_Unit
(Ent
)
2169 New_Occurrence_Of
(RTE
(RE_Null_Address
), Sloc
(N
)));
2172 Error_Attr
("invalid prefix for % attribute", P
);
2176 elsif Nkind
(P
) = N_Attribute_Reference
2177 and then Attribute_Name
(P
) = Name_AST_Entry
2180 New_Occurrence_Of
(RTE
(RE_Null_Address
), Sloc
(N
)));
2182 elsif Is_Object_Reference
(P
) then
2185 elsif Nkind
(P
) = N_Selected_Component
2186 and then Is_Subprogram
(Entity
(Selector_Name
(P
)))
2190 -- What exactly are we allowing here ??? and is this properly
2191 -- documented in the sinfo documentation for this node ???
2193 elsif not Comes_From_Source
(N
) then
2197 Error_Attr
("invalid prefix for % attribute", P
);
2200 Set_Etype
(N
, RTE
(RE_Address
));
2206 when Attribute_Address_Size
=>
2207 Standard_Attribute
(System_Address_Size
);
2213 when Attribute_Adjacent
=>
2214 Check_Floating_Point_Type_2
;
2215 Set_Etype
(N
, P_Base_Type
);
2216 Resolve
(E1
, P_Base_Type
);
2217 Resolve
(E2
, P_Base_Type
);
2223 when Attribute_Aft
=>
2224 Check_Fixed_Point_Type_0
;
2225 Set_Etype
(N
, Universal_Integer
);
2231 when Attribute_Alignment
=>
2233 -- Don't we need more checking here, cf Size ???
2236 Check_Not_Incomplete_Type
;
2238 Set_Etype
(N
, Universal_Integer
);
2244 when Attribute_Asm_Input
=>
2245 Check_Asm_Attribute
;
2246 Set_Etype
(N
, RTE
(RE_Asm_Input_Operand
));
2252 when Attribute_Asm_Output
=>
2253 Check_Asm_Attribute
;
2255 if Etype
(E2
) = Any_Type
then
2258 elsif Aname
= Name_Asm_Output
then
2259 if not Is_Variable
(E2
) then
2261 ("second argument for Asm_Output is not variable", E2
);
2265 Note_Possible_Modification
(E2
, Sure
=> True);
2266 Set_Etype
(N
, RTE
(RE_Asm_Output_Operand
));
2272 when Attribute_AST_Entry
=> AST_Entry
: declare
2278 -- Indicates if entry family index is present. Note the coding
2279 -- here handles the entry family case, but in fact it cannot be
2280 -- executed currently, because pragma AST_Entry does not permit
2281 -- the specification of an entry family.
2283 procedure Bad_AST_Entry
;
2284 -- Signal a bad AST_Entry pragma
2286 function OK_Entry
(E
: Entity_Id
) return Boolean;
2287 -- Checks that E is of an appropriate entity kind for an entry
2288 -- (i.e. E_Entry if Index is False, or E_Entry_Family if Index
2289 -- is set True for the entry family case). In the True case,
2290 -- makes sure that Is_AST_Entry is set on the entry.
2296 procedure Bad_AST_Entry
is
2298 Error_Attr_P
("prefix for % attribute must be task entry");
2305 function OK_Entry
(E
: Entity_Id
) return Boolean is
2310 Result
:= (Ekind
(E
) = E_Entry_Family
);
2312 Result
:= (Ekind
(E
) = E_Entry
);
2316 if not Is_AST_Entry
(E
) then
2317 Error_Msg_Name_2
:= Aname
;
2318 Error_Attr
("% attribute requires previous % pragma", P
);
2325 -- Start of processing for AST_Entry
2331 -- Deal with entry family case
2333 if Nkind
(P
) = N_Indexed_Component
then
2341 Ptyp
:= Etype
(Pref
);
2343 if Ptyp
= Any_Type
or else Error_Posted
(Pref
) then
2347 -- If the prefix is a selected component whose prefix is of an
2348 -- access type, then introduce an explicit dereference.
2349 -- ??? Could we reuse Check_Dereference here?
2351 if Nkind
(Pref
) = N_Selected_Component
2352 and then Is_Access_Type
(Ptyp
)
2355 Make_Explicit_Dereference
(Sloc
(Pref
),
2356 Relocate_Node
(Pref
)));
2357 Analyze_And_Resolve
(Pref
, Designated_Type
(Ptyp
));
2360 -- Prefix can be of the form a.b, where a is a task object
2361 -- and b is one of the entries of the corresponding task type.
2363 if Nkind
(Pref
) = N_Selected_Component
2364 and then OK_Entry
(Entity
(Selector_Name
(Pref
)))
2365 and then Is_Object_Reference
(Prefix
(Pref
))
2366 and then Is_Task_Type
(Etype
(Prefix
(Pref
)))
2370 -- Otherwise the prefix must be an entry of a containing task,
2371 -- or of a variable of the enclosing task type.
2374 if Nkind_In
(Pref
, N_Identifier
, N_Expanded_Name
) then
2375 Ent
:= Entity
(Pref
);
2377 if not OK_Entry
(Ent
)
2378 or else not In_Open_Scopes
(Scope
(Ent
))
2388 Set_Etype
(N
, RTE
(RE_AST_Handler
));
2395 -- Note: when the base attribute appears in the context of a subtype
2396 -- mark, the analysis is done by Sem_Ch8.Find_Type, rather than by
2397 -- the following circuit.
2399 when Attribute_Base
=> Base
: declare
2407 if Ada_Version
>= Ada_95
2408 and then not Is_Scalar_Type
(Typ
)
2409 and then not Is_Generic_Type
(Typ
)
2411 Error_Attr_P
("prefix of Base attribute must be scalar type");
2413 elsif Sloc
(Typ
) = Standard_Location
2414 and then Base_Type
(Typ
) = Typ
2415 and then Warn_On_Redundant_Constructs
2417 Error_Msg_NE
-- CODEFIX
2418 ("?redundant attribute, & is its own base type", N
, Typ
);
2421 Set_Etype
(N
, Base_Type
(Entity
(P
)));
2422 Set_Entity
(N
, Base_Type
(Entity
(P
)));
2423 Rewrite
(N
, New_Reference_To
(Entity
(N
), Loc
));
2431 when Attribute_Bit
=> Bit
:
2435 if not Is_Object_Reference
(P
) then
2436 Error_Attr_P
("prefix for % attribute must be object");
2438 -- What about the access object cases ???
2444 Set_Etype
(N
, Universal_Integer
);
2451 when Attribute_Bit_Order
=> Bit_Order
:
2456 if not Is_Record_Type
(P_Type
) then
2457 Error_Attr_P
("prefix of % attribute must be record type");
2460 if Bytes_Big_Endian
xor Reverse_Bit_Order
(P_Type
) then
2462 New_Occurrence_Of
(RTE
(RE_High_Order_First
), Loc
));
2465 New_Occurrence_Of
(RTE
(RE_Low_Order_First
), Loc
));
2468 Set_Etype
(N
, RTE
(RE_Bit_Order
));
2471 -- Reset incorrect indication of staticness
2473 Set_Is_Static_Expression
(N
, False);
2480 -- Note: in generated code, we can have a Bit_Position attribute
2481 -- applied to a (naked) record component (i.e. the prefix is an
2482 -- identifier that references an E_Component or E_Discriminant
2483 -- entity directly, and this is interpreted as expected by Gigi.
2484 -- The following code will not tolerate such usage, but when the
2485 -- expander creates this special case, it marks it as analyzed
2486 -- immediately and sets an appropriate type.
2488 when Attribute_Bit_Position
=>
2489 if Comes_From_Source
(N
) then
2493 Set_Etype
(N
, Universal_Integer
);
2499 when Attribute_Body_Version
=>
2502 Set_Etype
(N
, RTE
(RE_Version_String
));
2508 when Attribute_Callable
=>
2510 Set_Etype
(N
, Standard_Boolean
);
2517 when Attribute_Caller
=> Caller
: declare
2524 if Nkind_In
(P
, N_Identifier
, N_Expanded_Name
) then
2527 if not Is_Entry
(Ent
) then
2528 Error_Attr
("invalid entry name", N
);
2532 Error_Attr
("invalid entry name", N
);
2536 for J
in reverse 0 .. Scope_Stack
.Last
loop
2537 S
:= Scope_Stack
.Table
(J
).Entity
;
2539 if S
= Scope
(Ent
) then
2540 Error_Attr
("Caller must appear in matching accept or body", N
);
2546 Set_Etype
(N
, RTE
(RO_AT_Task_Id
));
2553 when Attribute_Ceiling
=>
2554 Check_Floating_Point_Type_1
;
2555 Set_Etype
(N
, P_Base_Type
);
2556 Resolve
(E1
, P_Base_Type
);
2562 when Attribute_Class
=>
2563 Check_Restriction
(No_Dispatch
, N
);
2567 -- Applying Class to untagged incomplete type is obsolescent in Ada
2568 -- 2005. Note that we can't test Is_Tagged_Type here on P_Type, since
2569 -- this flag gets set by Find_Type in this situation.
2571 if Restriction_Check_Required
(No_Obsolescent_Features
)
2572 and then Ada_Version
>= Ada_2005
2573 and then Ekind
(P_Type
) = E_Incomplete_Type
2576 DN
: constant Node_Id
:= Declaration_Node
(P_Type
);
2578 if Nkind
(DN
) = N_Incomplete_Type_Declaration
2579 and then not Tagged_Present
(DN
)
2581 Check_Restriction
(No_Obsolescent_Features
, P
);
2590 when Attribute_Code_Address
=>
2593 if Nkind
(P
) = N_Attribute_Reference
2594 and then (Attribute_Name
(P
) = Name_Elab_Body
2596 Attribute_Name
(P
) = Name_Elab_Spec
)
2600 elsif not Is_Entity_Name
(P
)
2601 or else (Ekind
(Entity
(P
)) /= E_Function
2603 Ekind
(Entity
(P
)) /= E_Procedure
)
2605 Error_Attr
("invalid prefix for % attribute", P
);
2606 Set_Address_Taken
(Entity
(P
));
2608 -- Issue an error if the prefix denotes an eliminated subprogram
2611 Check_For_Eliminated_Subprogram
(P
, Entity
(P
));
2614 Set_Etype
(N
, RTE
(RE_Address
));
2616 ----------------------
2617 -- Compiler_Version --
2618 ----------------------
2620 when Attribute_Compiler_Version
=>
2622 Check_Standard_Prefix
;
2623 Rewrite
(N
, Make_String_Literal
(Loc
, "GNAT " & Gnat_Version_String
));
2624 Analyze_And_Resolve
(N
, Standard_String
);
2626 --------------------
2627 -- Component_Size --
2628 --------------------
2630 when Attribute_Component_Size
=>
2632 Set_Etype
(N
, Universal_Integer
);
2634 -- Note: unlike other array attributes, unconstrained arrays are OK
2636 if Is_Array_Type
(P_Type
) and then not Is_Constrained
(P_Type
) then
2646 when Attribute_Compose
=>
2647 Check_Floating_Point_Type_2
;
2648 Set_Etype
(N
, P_Base_Type
);
2649 Resolve
(E1
, P_Base_Type
);
2650 Resolve
(E2
, Any_Integer
);
2656 when Attribute_Constrained
=>
2658 Set_Etype
(N
, Standard_Boolean
);
2660 -- Case from RM J.4(2) of constrained applied to private type
2662 if Is_Entity_Name
(P
) and then Is_Type
(Entity
(P
)) then
2663 Check_Restriction
(No_Obsolescent_Features
, P
);
2665 if Warn_On_Obsolescent_Feature
then
2667 ("constrained for private type is an " &
2668 "obsolescent feature (RM J.4)?", N
);
2671 -- If we are within an instance, the attribute must be legal
2672 -- because it was valid in the generic unit. Ditto if this is
2673 -- an inlining of a function declared in an instance.
2676 or else In_Inlined_Body
2680 -- For sure OK if we have a real private type itself, but must
2681 -- be completed, cannot apply Constrained to incomplete type.
2683 elsif Is_Private_Type
(Entity
(P
)) then
2685 -- Note: this is one of the Annex J features that does not
2686 -- generate a warning from -gnatwj, since in fact it seems
2687 -- very useful, and is used in the GNAT runtime.
2689 Check_Not_Incomplete_Type
;
2693 -- Normal (non-obsolescent case) of application to object of
2694 -- a discriminated type.
2697 Check_Object_Reference
(P
);
2699 -- If N does not come from source, then we allow the
2700 -- the attribute prefix to be of a private type whose
2701 -- full type has discriminants. This occurs in cases
2702 -- involving expanded calls to stream attributes.
2704 if not Comes_From_Source
(N
) then
2705 P_Type
:= Underlying_Type
(P_Type
);
2708 -- Must have discriminants or be an access type designating
2709 -- a type with discriminants. If it is a classwide type is ???
2710 -- has unknown discriminants.
2712 if Has_Discriminants
(P_Type
)
2713 or else Has_Unknown_Discriminants
(P_Type
)
2715 (Is_Access_Type
(P_Type
)
2716 and then Has_Discriminants
(Designated_Type
(P_Type
)))
2720 -- Also allow an object of a generic type if extensions allowed
2721 -- and allow this for any type at all.
2723 elsif (Is_Generic_Type
(P_Type
)
2724 or else Is_Generic_Actual_Type
(P_Type
))
2725 and then Extensions_Allowed
2731 -- Fall through if bad prefix
2734 ("prefix of % attribute must be object of discriminated type");
2740 when Attribute_Copy_Sign
=>
2741 Check_Floating_Point_Type_2
;
2742 Set_Etype
(N
, P_Base_Type
);
2743 Resolve
(E1
, P_Base_Type
);
2744 Resolve
(E2
, P_Base_Type
);
2750 when Attribute_Count
=> Count
:
2759 if Nkind_In
(P
, N_Identifier
, N_Expanded_Name
) then
2762 if Ekind
(Ent
) /= E_Entry
then
2763 Error_Attr
("invalid entry name", N
);
2766 elsif Nkind
(P
) = N_Indexed_Component
then
2767 if not Is_Entity_Name
(Prefix
(P
))
2768 or else No
(Entity
(Prefix
(P
)))
2769 or else Ekind
(Entity
(Prefix
(P
))) /= E_Entry_Family
2771 if Nkind
(Prefix
(P
)) = N_Selected_Component
2772 and then Present
(Entity
(Selector_Name
(Prefix
(P
))))
2773 and then Ekind
(Entity
(Selector_Name
(Prefix
(P
)))) =
2777 ("attribute % must apply to entry of current task", P
);
2780 Error_Attr
("invalid entry family name", P
);
2785 Ent
:= Entity
(Prefix
(P
));
2788 elsif Nkind
(P
) = N_Selected_Component
2789 and then Present
(Entity
(Selector_Name
(P
)))
2790 and then Ekind
(Entity
(Selector_Name
(P
))) = E_Entry
2793 ("attribute % must apply to entry of current task", P
);
2796 Error_Attr
("invalid entry name", N
);
2800 for J
in reverse 0 .. Scope_Stack
.Last
loop
2801 S
:= Scope_Stack
.Table
(J
).Entity
;
2803 if S
= Scope
(Ent
) then
2804 if Nkind
(P
) = N_Expanded_Name
then
2805 Tsk
:= Entity
(Prefix
(P
));
2807 -- The prefix denotes either the task type, or else a
2808 -- single task whose task type is being analyzed.
2813 or else (not Is_Type
(Tsk
)
2814 and then Etype
(Tsk
) = S
2815 and then not (Comes_From_Source
(S
)))
2820 ("Attribute % must apply to entry of current task", N
);
2826 elsif Ekind
(Scope
(Ent
)) in Task_Kind
2828 not Ekind_In
(S
, E_Loop
, E_Block
, E_Entry
, E_Entry_Family
)
2830 Error_Attr
("Attribute % cannot appear in inner unit", N
);
2832 elsif Ekind
(Scope
(Ent
)) = E_Protected_Type
2833 and then not Has_Completion
(Scope
(Ent
))
2835 Error_Attr
("attribute % can only be used inside body", N
);
2839 if Is_Overloaded
(P
) then
2841 Index
: Interp_Index
;
2845 Get_First_Interp
(P
, Index
, It
);
2847 while Present
(It
.Nam
) loop
2848 if It
.Nam
= Ent
then
2851 -- Ada 2005 (AI-345): Do not consider primitive entry
2852 -- wrappers generated for task or protected types.
2854 elsif Ada_Version
>= Ada_2005
2855 and then not Comes_From_Source
(It
.Nam
)
2860 Error_Attr
("ambiguous entry name", N
);
2863 Get_Next_Interp
(Index
, It
);
2868 Set_Etype
(N
, Universal_Integer
);
2871 -----------------------
2872 -- Default_Bit_Order --
2873 -----------------------
2875 when Attribute_Default_Bit_Order
=> Default_Bit_Order
:
2877 Check_Standard_Prefix
;
2879 if Bytes_Big_Endian
then
2881 Make_Integer_Literal
(Loc
, False_Value
));
2884 Make_Integer_Literal
(Loc
, True_Value
));
2887 Set_Etype
(N
, Universal_Integer
);
2888 Set_Is_Static_Expression
(N
);
2889 end Default_Bit_Order
;
2895 when Attribute_Definite
=>
2896 Legal_Formal_Attribute
;
2902 when Attribute_Delta
=>
2903 Check_Fixed_Point_Type_0
;
2904 Set_Etype
(N
, Universal_Real
);
2910 when Attribute_Denorm
=>
2911 Check_Floating_Point_Type_0
;
2912 Set_Etype
(N
, Standard_Boolean
);
2918 when Attribute_Digits
=>
2922 if not Is_Floating_Point_Type
(P_Type
)
2923 and then not Is_Decimal_Fixed_Point_Type
(P_Type
)
2926 ("prefix of % attribute must be float or decimal type");
2929 Set_Etype
(N
, Universal_Integer
);
2935 -- Also handles processing for Elab_Spec
2937 when Attribute_Elab_Body | Attribute_Elab_Spec
=>
2939 Check_Unit_Name
(P
);
2940 Set_Etype
(N
, Standard_Void_Type
);
2942 -- We have to manually call the expander in this case to get
2943 -- the necessary expansion (normally attributes that return
2944 -- entities are not expanded).
2952 -- Shares processing with Elab_Body
2958 when Attribute_Elaborated
=>
2961 Set_Etype
(N
, Standard_Boolean
);
2967 when Attribute_Emax
=>
2968 Check_Floating_Point_Type_0
;
2969 Set_Etype
(N
, Universal_Integer
);
2975 when Attribute_Enabled
=>
2976 Check_Either_E0_Or_E1
;
2978 if Present
(E1
) then
2979 if not Is_Entity_Name
(E1
) or else No
(Entity
(E1
)) then
2980 Error_Msg_N
("entity name expected for Enabled attribute", E1
);
2985 if Nkind
(P
) /= N_Identifier
then
2986 Error_Msg_N
("identifier expected (check name)", P
);
2987 elsif Get_Check_Id
(Chars
(P
)) = No_Check_Id
then
2988 Error_Msg_N
("& is not a recognized check name", P
);
2991 Set_Etype
(N
, Standard_Boolean
);
2997 when Attribute_Enum_Rep
=> Enum_Rep
: declare
2999 if Present
(E1
) then
3001 Check_Discrete_Type
;
3002 Resolve
(E1
, P_Base_Type
);
3005 if not Is_Entity_Name
(P
)
3006 or else (not Is_Object
(Entity
(P
))
3008 Ekind
(Entity
(P
)) /= E_Enumeration_Literal
)
3011 ("prefix of % attribute must be " &
3012 "discrete type/object or enum literal");
3016 Set_Etype
(N
, Universal_Integer
);
3023 when Attribute_Enum_Val
=> Enum_Val
: begin
3027 if not Is_Enumeration_Type
(P_Type
) then
3028 Error_Attr_P
("prefix of % attribute must be enumeration type");
3031 -- If the enumeration type has a standard representation, the effect
3032 -- is the same as 'Val, so rewrite the attribute as a 'Val.
3034 if not Has_Non_Standard_Rep
(P_Base_Type
) then
3036 Make_Attribute_Reference
(Loc
,
3037 Prefix
=> Relocate_Node
(Prefix
(N
)),
3038 Attribute_Name
=> Name_Val
,
3039 Expressions
=> New_List
(Relocate_Node
(E1
))));
3040 Analyze_And_Resolve
(N
, P_Base_Type
);
3042 -- Non-standard representation case (enumeration with holes)
3046 Resolve
(E1
, Any_Integer
);
3047 Set_Etype
(N
, P_Base_Type
);
3055 when Attribute_Epsilon
=>
3056 Check_Floating_Point_Type_0
;
3057 Set_Etype
(N
, Universal_Real
);
3063 when Attribute_Exponent
=>
3064 Check_Floating_Point_Type_1
;
3065 Set_Etype
(N
, Universal_Integer
);
3066 Resolve
(E1
, P_Base_Type
);
3072 when Attribute_External_Tag
=>
3076 Set_Etype
(N
, Standard_String
);
3078 if not Is_Tagged_Type
(P_Type
) then
3079 Error_Attr_P
("prefix of % attribute must be tagged");
3086 when Attribute_Fast_Math
=>
3087 Check_Standard_Prefix
;
3089 if Opt
.Fast_Math
then
3090 Rewrite
(N
, New_Occurrence_Of
(Standard_True
, Loc
));
3092 Rewrite
(N
, New_Occurrence_Of
(Standard_False
, Loc
));
3099 when Attribute_First
=>
3100 Check_Array_Or_Scalar_Type
;
3101 Bad_Attribute_For_Predicate
;
3107 when Attribute_First_Bit
=>
3109 Set_Etype
(N
, Universal_Integer
);
3115 when Attribute_Fixed_Value
=>
3117 Check_Fixed_Point_Type
;
3118 Resolve
(E1
, Any_Integer
);
3119 Set_Etype
(N
, P_Base_Type
);
3125 when Attribute_Floor
=>
3126 Check_Floating_Point_Type_1
;
3127 Set_Etype
(N
, P_Base_Type
);
3128 Resolve
(E1
, P_Base_Type
);
3134 when Attribute_Fore
=>
3135 Check_Fixed_Point_Type_0
;
3136 Set_Etype
(N
, Universal_Integer
);
3142 when Attribute_Fraction
=>
3143 Check_Floating_Point_Type_1
;
3144 Set_Etype
(N
, P_Base_Type
);
3145 Resolve
(E1
, P_Base_Type
);
3151 when Attribute_From_Any
=>
3153 Check_PolyORB_Attribute
;
3154 Set_Etype
(N
, P_Base_Type
);
3156 -----------------------
3157 -- Has_Access_Values --
3158 -----------------------
3160 when Attribute_Has_Access_Values
=>
3163 Set_Etype
(N
, Standard_Boolean
);
3165 -----------------------
3166 -- Has_Tagged_Values --
3167 -----------------------
3169 when Attribute_Has_Tagged_Values
=>
3172 Set_Etype
(N
, Standard_Boolean
);
3174 -----------------------
3175 -- Has_Discriminants --
3176 -----------------------
3178 when Attribute_Has_Discriminants
=>
3179 Legal_Formal_Attribute
;
3185 when Attribute_Identity
=>
3189 if Etype
(P
) = Standard_Exception_Type
then
3190 Set_Etype
(N
, RTE
(RE_Exception_Id
));
3192 -- Ada 2005 (AI-345): Attribute 'Identity may be applied to
3193 -- task interface class-wide types.
3195 elsif Is_Task_Type
(Etype
(P
))
3196 or else (Is_Access_Type
(Etype
(P
))
3197 and then Is_Task_Type
(Designated_Type
(Etype
(P
))))
3198 or else (Ada_Version
>= Ada_2005
3199 and then Ekind
(Etype
(P
)) = E_Class_Wide_Type
3200 and then Is_Interface
(Etype
(P
))
3201 and then Is_Task_Interface
(Etype
(P
)))
3204 Set_Etype
(N
, RTE
(RO_AT_Task_Id
));
3207 if Ada_Version
>= Ada_2005
then
3209 ("prefix of % attribute must be an exception, a " &
3210 "task or a task interface class-wide object");
3213 ("prefix of % attribute must be a task or an exception");
3221 when Attribute_Image
=> Image
:
3223 Set_Etype
(N
, Standard_String
);
3226 if Is_Real_Type
(P_Type
) then
3227 if Ada_Version
= Ada_83
and then Comes_From_Source
(N
) then
3228 Error_Msg_Name_1
:= Aname
;
3230 ("(Ada 83) % attribute not allowed for real types", N
);
3234 if Is_Enumeration_Type
(P_Type
) then
3235 Check_Restriction
(No_Enumeration_Maps
, N
);
3239 Resolve
(E1
, P_Base_Type
);
3241 Validate_Non_Static_Attribute_Function_Call
;
3248 when Attribute_Img
=> Img
:
3251 Set_Etype
(N
, Standard_String
);
3253 if not Is_Scalar_Type
(P_Type
)
3254 or else (Is_Entity_Name
(P
) and then Is_Type
(Entity
(P
)))
3257 ("prefix of % attribute must be scalar object name");
3267 when Attribute_Input
=>
3269 Check_Stream_Attribute
(TSS_Stream_Input
);
3270 Set_Etype
(N
, P_Base_Type
);
3276 when Attribute_Integer_Value
=>
3279 Resolve
(E1
, Any_Fixed
);
3281 -- Signal an error if argument type is not a specific fixed-point
3282 -- subtype. An error has been signalled already if the argument
3283 -- was not of a fixed-point type.
3285 if Etype
(E1
) = Any_Fixed
and then not Error_Posted
(E1
) then
3286 Error_Attr
("argument of % must be of a fixed-point type", E1
);
3289 Set_Etype
(N
, P_Base_Type
);
3295 when Attribute_Invalid_Value
=>
3298 Set_Etype
(N
, P_Base_Type
);
3299 Invalid_Value_Used
:= True;
3305 when Attribute_Large
=>
3308 Set_Etype
(N
, Universal_Real
);
3314 when Attribute_Last
=>
3315 Check_Array_Or_Scalar_Type
;
3316 Bad_Attribute_For_Predicate
;
3322 when Attribute_Last_Bit
=>
3324 Set_Etype
(N
, Universal_Integer
);
3330 when Attribute_Leading_Part
=>
3331 Check_Floating_Point_Type_2
;
3332 Set_Etype
(N
, P_Base_Type
);
3333 Resolve
(E1
, P_Base_Type
);
3334 Resolve
(E2
, Any_Integer
);
3340 when Attribute_Length
=>
3342 Set_Etype
(N
, Universal_Integer
);
3348 when Attribute_Machine
=>
3349 Check_Floating_Point_Type_1
;
3350 Set_Etype
(N
, P_Base_Type
);
3351 Resolve
(E1
, P_Base_Type
);
3357 when Attribute_Machine_Emax
=>
3358 Check_Floating_Point_Type_0
;
3359 Set_Etype
(N
, Universal_Integer
);
3365 when Attribute_Machine_Emin
=>
3366 Check_Floating_Point_Type_0
;
3367 Set_Etype
(N
, Universal_Integer
);
3369 ----------------------
3370 -- Machine_Mantissa --
3371 ----------------------
3373 when Attribute_Machine_Mantissa
=>
3374 Check_Floating_Point_Type_0
;
3375 Set_Etype
(N
, Universal_Integer
);
3377 -----------------------
3378 -- Machine_Overflows --
3379 -----------------------
3381 when Attribute_Machine_Overflows
=>
3384 Set_Etype
(N
, Standard_Boolean
);
3390 when Attribute_Machine_Radix
=>
3393 Set_Etype
(N
, Universal_Integer
);
3395 ----------------------
3396 -- Machine_Rounding --
3397 ----------------------
3399 when Attribute_Machine_Rounding
=>
3400 Check_Floating_Point_Type_1
;
3401 Set_Etype
(N
, P_Base_Type
);
3402 Resolve
(E1
, P_Base_Type
);
3404 --------------------
3405 -- Machine_Rounds --
3406 --------------------
3408 when Attribute_Machine_Rounds
=>
3411 Set_Etype
(N
, Standard_Boolean
);
3417 when Attribute_Machine_Size
=>
3420 Check_Not_Incomplete_Type
;
3421 Set_Etype
(N
, Universal_Integer
);
3427 when Attribute_Mantissa
=>
3430 Set_Etype
(N
, Universal_Integer
);
3436 when Attribute_Max
=>
3439 Resolve
(E1
, P_Base_Type
);
3440 Resolve
(E2
, P_Base_Type
);
3441 Set_Etype
(N
, P_Base_Type
);
3443 ----------------------------------
3444 -- Max_Alignment_For_Allocation --
3445 -- Max_Size_In_Storage_Elements --
3446 ----------------------------------
3448 when Attribute_Max_Alignment_For_Allocation |
3449 Attribute_Max_Size_In_Storage_Elements
=>
3452 Check_Not_Incomplete_Type
;
3453 Set_Etype
(N
, Universal_Integer
);
3455 -----------------------
3456 -- Maximum_Alignment --
3457 -----------------------
3459 when Attribute_Maximum_Alignment
=>
3460 Standard_Attribute
(Ttypes
.Maximum_Alignment
);
3462 --------------------
3463 -- Mechanism_Code --
3464 --------------------
3466 when Attribute_Mechanism_Code
=>
3467 if not Is_Entity_Name
(P
)
3468 or else not Is_Subprogram
(Entity
(P
))
3470 Error_Attr_P
("prefix of % attribute must be subprogram");
3473 Check_Either_E0_Or_E1
;
3475 if Present
(E1
) then
3476 Resolve
(E1
, Any_Integer
);
3477 Set_Etype
(E1
, Standard_Integer
);
3479 if not Is_Static_Expression
(E1
) then
3480 Flag_Non_Static_Expr
3481 ("expression for parameter number must be static!", E1
);
3484 elsif UI_To_Int
(Intval
(E1
)) > Number_Formals
(Entity
(P
))
3485 or else UI_To_Int
(Intval
(E1
)) < 0
3487 Error_Attr
("invalid parameter number for % attribute", E1
);
3491 Set_Etype
(N
, Universal_Integer
);
3497 when Attribute_Min
=>
3500 Resolve
(E1
, P_Base_Type
);
3501 Resolve
(E2
, P_Base_Type
);
3502 Set_Etype
(N
, P_Base_Type
);
3508 when Attribute_Mod
=>
3510 -- Note: this attribute is only allowed in Ada 2005 mode, but
3511 -- we do not need to test that here, since Mod is only recognized
3512 -- as an attribute name in Ada 2005 mode during the parse.
3515 Check_Modular_Integer_Type
;
3516 Resolve
(E1
, Any_Integer
);
3517 Set_Etype
(N
, P_Base_Type
);
3523 when Attribute_Model
=>
3524 Check_Floating_Point_Type_1
;
3525 Set_Etype
(N
, P_Base_Type
);
3526 Resolve
(E1
, P_Base_Type
);
3532 when Attribute_Model_Emin
=>
3533 Check_Floating_Point_Type_0
;
3534 Set_Etype
(N
, Universal_Integer
);
3540 when Attribute_Model_Epsilon
=>
3541 Check_Floating_Point_Type_0
;
3542 Set_Etype
(N
, Universal_Real
);
3544 --------------------
3545 -- Model_Mantissa --
3546 --------------------
3548 when Attribute_Model_Mantissa
=>
3549 Check_Floating_Point_Type_0
;
3550 Set_Etype
(N
, Universal_Integer
);
3556 when Attribute_Model_Small
=>
3557 Check_Floating_Point_Type_0
;
3558 Set_Etype
(N
, Universal_Real
);
3564 when Attribute_Modulus
=>
3566 Check_Modular_Integer_Type
;
3567 Set_Etype
(N
, Universal_Integer
);
3569 --------------------
3570 -- Null_Parameter --
3571 --------------------
3573 when Attribute_Null_Parameter
=> Null_Parameter
: declare
3574 Parnt
: constant Node_Id
:= Parent
(N
);
3575 GParnt
: constant Node_Id
:= Parent
(Parnt
);
3577 procedure Bad_Null_Parameter
(Msg
: String);
3578 -- Used if bad Null parameter attribute node is found. Issues
3579 -- given error message, and also sets the type to Any_Type to
3580 -- avoid blowups later on from dealing with a junk node.
3582 procedure Must_Be_Imported
(Proc_Ent
: Entity_Id
);
3583 -- Called to check that Proc_Ent is imported subprogram
3585 ------------------------
3586 -- Bad_Null_Parameter --
3587 ------------------------
3589 procedure Bad_Null_Parameter
(Msg
: String) is
3591 Error_Msg_N
(Msg
, N
);
3592 Set_Etype
(N
, Any_Type
);
3593 end Bad_Null_Parameter
;
3595 ----------------------
3596 -- Must_Be_Imported --
3597 ----------------------
3599 procedure Must_Be_Imported
(Proc_Ent
: Entity_Id
) is
3600 Pent
: constant Entity_Id
:= Ultimate_Alias
(Proc_Ent
);
3603 -- Ignore check if procedure not frozen yet (we will get
3604 -- another chance when the default parameter is reanalyzed)
3606 if not Is_Frozen
(Pent
) then
3609 elsif not Is_Imported
(Pent
) then
3611 ("Null_Parameter can only be used with imported subprogram");
3616 end Must_Be_Imported
;
3618 -- Start of processing for Null_Parameter
3623 Set_Etype
(N
, P_Type
);
3625 -- Case of attribute used as default expression
3627 if Nkind
(Parnt
) = N_Parameter_Specification
then
3628 Must_Be_Imported
(Defining_Entity
(GParnt
));
3630 -- Case of attribute used as actual for subprogram (positional)
3632 elsif Nkind_In
(Parnt
, N_Procedure_Call_Statement
,
3634 and then Is_Entity_Name
(Name
(Parnt
))
3636 Must_Be_Imported
(Entity
(Name
(Parnt
)));
3638 -- Case of attribute used as actual for subprogram (named)
3640 elsif Nkind
(Parnt
) = N_Parameter_Association
3641 and then Nkind_In
(GParnt
, N_Procedure_Call_Statement
,
3643 and then Is_Entity_Name
(Name
(GParnt
))
3645 Must_Be_Imported
(Entity
(Name
(GParnt
)));
3647 -- Not an allowed case
3651 ("Null_Parameter must be actual or default parameter");
3659 when Attribute_Object_Size
=>
3662 Check_Not_Incomplete_Type
;
3663 Set_Etype
(N
, Universal_Integer
);
3669 when Attribute_Old
=>
3671 -- The attribute reference is a primary. If expressions follow, the
3672 -- attribute reference is an indexable object, so rewrite the node
3675 if Present
(E1
) then
3677 Make_Indexed_Component
(Loc
,
3679 Make_Attribute_Reference
(Loc
,
3680 Prefix
=> Relocate_Node
(Prefix
(N
)),
3681 Attribute_Name
=> Name_Old
),
3682 Expressions
=> Expressions
(N
)));
3689 Set_Etype
(N
, P_Type
);
3691 if No
(Current_Subprogram
) then
3692 Error_Attr
("attribute % can only appear within subprogram", N
);
3695 if Is_Limited_Type
(P_Type
) then
3696 Error_Attr
("attribute % cannot apply to limited objects", P
);
3699 if Is_Entity_Name
(P
)
3700 and then Is_Constant_Object
(Entity
(P
))
3703 ("?attribute Old applied to constant has no effect", P
);
3706 -- Check that the expression does not refer to local entities
3708 Check_Local
: declare
3709 Subp
: Entity_Id
:= Current_Subprogram
;
3711 function Process
(N
: Node_Id
) return Traverse_Result
;
3712 -- Check that N does not contain references to local variables or
3713 -- other local entities of Subp.
3719 function Process
(N
: Node_Id
) return Traverse_Result
is
3721 if Is_Entity_Name
(N
)
3722 and then Present
(Entity
(N
))
3723 and then not Is_Formal
(Entity
(N
))
3724 and then Enclosing_Subprogram
(Entity
(N
)) = Subp
3726 Error_Msg_Node_1
:= Entity
(N
);
3728 ("attribute % cannot refer to local variable&", N
);
3734 procedure Check_No_Local
is new Traverse_Proc
;
3736 -- Start of processing for Check_Local
3741 if In_Parameter_Specification
(P
) then
3743 -- We have additional restrictions on using 'Old in parameter
3746 if Present
(Enclosing_Subprogram
(Current_Subprogram
)) then
3748 -- Check that there is no reference to the enclosing
3749 -- subprogram local variables. Otherwise, we might end up
3750 -- being called from the enclosing subprogram and thus using
3751 -- 'Old on a local variable which is not defined at entry
3754 Subp
:= Enclosing_Subprogram
(Current_Subprogram
);
3758 -- We must prevent default expression of library-level
3759 -- subprogram from using 'Old, as the subprogram may be
3760 -- used in elaboration code for which there is no enclosing
3764 ("attribute % can only appear within subprogram", N
);
3773 when Attribute_Output
=>
3775 Check_Stream_Attribute
(TSS_Stream_Output
);
3776 Set_Etype
(N
, Standard_Void_Type
);
3777 Resolve
(N
, Standard_Void_Type
);
3783 when Attribute_Partition_ID
=> Partition_Id
:
3787 if P_Type
/= Any_Type
then
3788 if not Is_Library_Level_Entity
(Entity
(P
)) then
3790 ("prefix of % attribute must be library-level entity");
3792 -- The defining entity of prefix should not be declared inside a
3793 -- Pure unit. RM E.1(8). Is_Pure was set during declaration.
3795 elsif Is_Entity_Name
(P
)
3796 and then Is_Pure
(Entity
(P
))
3798 Error_Attr_P
("prefix of% attribute must not be declared pure");
3802 Set_Etype
(N
, Universal_Integer
);
3805 -------------------------
3806 -- Passed_By_Reference --
3807 -------------------------
3809 when Attribute_Passed_By_Reference
=>
3812 Set_Etype
(N
, Standard_Boolean
);
3818 when Attribute_Pool_Address
=>
3820 Set_Etype
(N
, RTE
(RE_Address
));
3826 when Attribute_Pos
=>
3827 Check_Discrete_Type
;
3829 Resolve
(E1
, P_Base_Type
);
3830 Set_Etype
(N
, Universal_Integer
);
3836 when Attribute_Position
=>
3838 Set_Etype
(N
, Universal_Integer
);
3844 when Attribute_Pred
=>
3847 Resolve
(E1
, P_Base_Type
);
3848 Set_Etype
(N
, P_Base_Type
);
3850 -- Nothing to do for real type case
3852 if Is_Real_Type
(P_Type
) then
3855 -- If not modular type, test for overflow check required
3858 if not Is_Modular_Integer_Type
(P_Type
)
3859 and then not Range_Checks_Suppressed
(P_Base_Type
)
3861 Enable_Range_Check
(E1
);
3869 -- Ada 2005 (AI-327): Dynamic ceiling priorities
3871 when Attribute_Priority
=>
3872 if Ada_Version
< Ada_2005
then
3873 Error_Attr
("% attribute is allowed only in Ada 2005 mode", P
);
3878 -- The prefix must be a protected object (AARM D.5.2 (2/2))
3882 if Is_Protected_Type
(Etype
(P
))
3883 or else (Is_Access_Type
(Etype
(P
))
3884 and then Is_Protected_Type
(Designated_Type
(Etype
(P
))))
3886 Resolve
(P
, Etype
(P
));
3888 Error_Attr_P
("prefix of % attribute must be a protected object");
3891 Set_Etype
(N
, Standard_Integer
);
3893 -- Must be called from within a protected procedure or entry of the
3894 -- protected object.
3901 while S
/= Etype
(P
)
3902 and then S
/= Standard_Standard
3907 if S
= Standard_Standard
then
3908 Error_Attr
("the attribute % is only allowed inside protected "
3913 Validate_Non_Static_Attribute_Function_Call
;
3919 when Attribute_Range
=>
3920 Check_Array_Or_Scalar_Type
;
3921 Bad_Attribute_For_Predicate
;
3923 if Ada_Version
= Ada_83
3924 and then Is_Scalar_Type
(P_Type
)
3925 and then Comes_From_Source
(N
)
3928 ("(Ada 83) % attribute not allowed for scalar type", P
);
3935 when Attribute_Result
=> Result
: declare
3936 CS
: Entity_Id
:= Current_Scope
;
3937 PS
: Entity_Id
:= Scope
(CS
);
3940 -- If the enclosing subprogram is always inlined, the enclosing
3941 -- postcondition will not be propagated to the expanded call.
3943 if Has_Pragma_Inline_Always
(PS
)
3944 and then Warn_On_Redundant_Constructs
3947 ("postconditions on inlined functions not enforced?", N
);
3950 -- If we are in the scope of a function and in Spec_Expression mode,
3951 -- this is likely the prescan of the postcondition pragma, and we
3952 -- just set the proper type. If there is an error it will be caught
3953 -- when the real Analyze call is done.
3955 if Ekind
(CS
) = E_Function
3956 and then In_Spec_Expression
3960 if Chars
(CS
) /= Chars
(P
) then
3962 ("incorrect prefix for % attribute, expected &", P
, CS
);
3966 Set_Etype
(N
, Etype
(CS
));
3968 -- If several functions with that name are visible,
3969 -- the intended one is the current scope.
3971 if Is_Overloaded
(P
) then
3973 Set_Is_Overloaded
(P
, False);
3976 -- Body case, where we must be inside a generated _Postcondition
3977 -- procedure, and the prefix must be on the scope stack, or else
3978 -- the attribute use is definitely misplaced. The condition itself
3979 -- may have generated transient scopes, and is not necessarily the
3984 and then CS
/= Standard_Standard
3986 if Chars
(CS
) = Name_uPostconditions
then
3995 if Chars
(CS
) = Name_uPostconditions
3996 and then Ekind
(PS
) = E_Function
4000 if Nkind_In
(P
, N_Identifier
, N_Operator_Symbol
)
4001 and then Chars
(P
) = Chars
(PS
)
4005 -- Within an instance, the prefix designates the local renaming
4006 -- of the original generic.
4008 elsif Is_Entity_Name
(P
)
4009 and then Ekind
(Entity
(P
)) = E_Function
4010 and then Present
(Alias
(Entity
(P
)))
4011 and then Chars
(Alias
(Entity
(P
))) = Chars
(PS
)
4017 ("incorrect prefix for % attribute, expected &", P
, PS
);
4021 Rewrite
(N
, Make_Identifier
(Sloc
(N
), Name_uResult
));
4022 Analyze_And_Resolve
(N
, Etype
(PS
));
4026 ("% attribute can only appear" &
4027 " in function Postcondition pragma", P
);
4036 when Attribute_Range_Length
=>
4038 Check_Discrete_Type
;
4039 Set_Etype
(N
, Universal_Integer
);
4045 when Attribute_Read
=>
4047 Check_Stream_Attribute
(TSS_Stream_Read
);
4048 Set_Etype
(N
, Standard_Void_Type
);
4049 Resolve
(N
, Standard_Void_Type
);
4050 Note_Possible_Modification
(E2
, Sure
=> True);
4056 when Attribute_Ref
=>
4060 if Nkind
(P
) /= N_Expanded_Name
4061 or else not Is_RTE
(P_Type
, RE_Address
)
4063 Error_Attr_P
("prefix of % attribute must be System.Address");
4066 Analyze_And_Resolve
(E1
, Any_Integer
);
4067 Set_Etype
(N
, RTE
(RE_Address
));
4073 when Attribute_Remainder
=>
4074 Check_Floating_Point_Type_2
;
4075 Set_Etype
(N
, P_Base_Type
);
4076 Resolve
(E1
, P_Base_Type
);
4077 Resolve
(E2
, P_Base_Type
);
4083 when Attribute_Round
=>
4085 Check_Decimal_Fixed_Point_Type
;
4086 Set_Etype
(N
, P_Base_Type
);
4088 -- Because the context is universal_real (3.5.10(12)) it is a legal
4089 -- context for a universal fixed expression. This is the only
4090 -- attribute whose functional description involves U_R.
4092 if Etype
(E1
) = Universal_Fixed
then
4094 Conv
: constant Node_Id
:= Make_Type_Conversion
(Loc
,
4095 Subtype_Mark
=> New_Occurrence_Of
(Universal_Real
, Loc
),
4096 Expression
=> Relocate_Node
(E1
));
4104 Resolve
(E1
, Any_Real
);
4110 when Attribute_Rounding
=>
4111 Check_Floating_Point_Type_1
;
4112 Set_Etype
(N
, P_Base_Type
);
4113 Resolve
(E1
, P_Base_Type
);
4119 when Attribute_Safe_Emax
=>
4120 Check_Floating_Point_Type_0
;
4121 Set_Etype
(N
, Universal_Integer
);
4127 when Attribute_Safe_First
=>
4128 Check_Floating_Point_Type_0
;
4129 Set_Etype
(N
, Universal_Real
);
4135 when Attribute_Safe_Large
=>
4138 Set_Etype
(N
, Universal_Real
);
4144 when Attribute_Safe_Last
=>
4145 Check_Floating_Point_Type_0
;
4146 Set_Etype
(N
, Universal_Real
);
4152 when Attribute_Safe_Small
=>
4155 Set_Etype
(N
, Universal_Real
);
4161 when Attribute_Scale
=>
4163 Check_Decimal_Fixed_Point_Type
;
4164 Set_Etype
(N
, Universal_Integer
);
4170 when Attribute_Scaling
=>
4171 Check_Floating_Point_Type_2
;
4172 Set_Etype
(N
, P_Base_Type
);
4173 Resolve
(E1
, P_Base_Type
);
4179 when Attribute_Signed_Zeros
=>
4180 Check_Floating_Point_Type_0
;
4181 Set_Etype
(N
, Standard_Boolean
);
4187 when Attribute_Size | Attribute_VADS_Size
=> Size
:
4191 -- If prefix is parameterless function call, rewrite and resolve
4194 if Is_Entity_Name
(P
)
4195 and then Ekind
(Entity
(P
)) = E_Function
4199 -- Similar processing for a protected function call
4201 elsif Nkind
(P
) = N_Selected_Component
4202 and then Ekind
(Entity
(Selector_Name
(P
))) = E_Function
4207 if Is_Object_Reference
(P
) then
4208 Check_Object_Reference
(P
);
4210 elsif Is_Entity_Name
(P
)
4211 and then (Is_Type
(Entity
(P
))
4212 or else Ekind
(Entity
(P
)) = E_Enumeration_Literal
)
4216 elsif Nkind
(P
) = N_Type_Conversion
4217 and then not Comes_From_Source
(P
)
4222 Error_Attr_P
("invalid prefix for % attribute");
4225 Check_Not_Incomplete_Type
;
4227 Set_Etype
(N
, Universal_Integer
);
4234 when Attribute_Small
=>
4237 Set_Etype
(N
, Universal_Real
);
4243 when Attribute_Storage_Pool
=> Storage_Pool
:
4247 if Is_Access_Type
(P_Type
) then
4248 if Ekind
(P_Type
) = E_Access_Subprogram_Type
then
4250 ("cannot use % attribute for access-to-subprogram type");
4253 -- Set appropriate entity
4255 if Present
(Associated_Storage_Pool
(Root_Type
(P_Type
))) then
4256 Set_Entity
(N
, Associated_Storage_Pool
(Root_Type
(P_Type
)));
4258 Set_Entity
(N
, RTE
(RE_Global_Pool_Object
));
4261 Set_Etype
(N
, Class_Wide_Type
(RTE
(RE_Root_Storage_Pool
)));
4263 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4264 -- Storage_Pool since this attribute is not defined for such
4265 -- types (RM E.2.3(22)).
4267 Validate_Remote_Access_To_Class_Wide_Type
(N
);
4270 Error_Attr_P
("prefix of % attribute must be access type");
4278 when Attribute_Storage_Size
=> Storage_Size
:
4282 if Is_Task_Type
(P_Type
) then
4283 Set_Etype
(N
, Universal_Integer
);
4285 -- Use with tasks is an obsolescent feature
4287 Check_Restriction
(No_Obsolescent_Features
, P
);
4289 elsif Is_Access_Type
(P_Type
) then
4290 if Ekind
(P_Type
) = E_Access_Subprogram_Type
then
4292 ("cannot use % attribute for access-to-subprogram type");
4295 if Is_Entity_Name
(P
)
4296 and then Is_Type
(Entity
(P
))
4299 Set_Etype
(N
, Universal_Integer
);
4301 -- Validate_Remote_Access_To_Class_Wide_Type for attribute
4302 -- Storage_Size since this attribute is not defined for
4303 -- such types (RM E.2.3(22)).
4305 Validate_Remote_Access_To_Class_Wide_Type
(N
);
4307 -- The prefix is allowed to be an implicit dereference
4308 -- of an access value designating a task.
4312 Set_Etype
(N
, Universal_Integer
);
4316 Error_Attr_P
("prefix of % attribute must be access or task type");
4324 when Attribute_Storage_Unit
=>
4325 Standard_Attribute
(Ttypes
.System_Storage_Unit
);
4331 when Attribute_Stream_Size
=>
4335 if Is_Entity_Name
(P
)
4336 and then Is_Elementary_Type
(Entity
(P
))
4338 Set_Etype
(N
, Universal_Integer
);
4340 Error_Attr_P
("invalid prefix for % attribute");
4347 when Attribute_Stub_Type
=>
4351 if Is_Remote_Access_To_Class_Wide_Type
(P_Type
) then
4353 New_Occurrence_Of
(Corresponding_Stub_Type
(P_Type
), Loc
));
4356 ("prefix of% attribute must be remote access to classwide");
4363 when Attribute_Succ
=>
4366 Resolve
(E1
, P_Base_Type
);
4367 Set_Etype
(N
, P_Base_Type
);
4369 -- Nothing to do for real type case
4371 if Is_Real_Type
(P_Type
) then
4374 -- If not modular type, test for overflow check required
4377 if not Is_Modular_Integer_Type
(P_Type
)
4378 and then not Range_Checks_Suppressed
(P_Base_Type
)
4380 Enable_Range_Check
(E1
);
4388 when Attribute_Tag
=> Tag
:
4393 if not Is_Tagged_Type
(P_Type
) then
4394 Error_Attr_P
("prefix of % attribute must be tagged");
4396 -- Next test does not apply to generated code
4397 -- why not, and what does the illegal reference mean???
4399 elsif Is_Object_Reference
(P
)
4400 and then not Is_Class_Wide_Type
(P_Type
)
4401 and then Comes_From_Source
(N
)
4404 ("% attribute can only be applied to objects " &
4405 "of class - wide type");
4408 -- The prefix cannot be an incomplete type. However, references
4409 -- to 'Tag can be generated when expanding interface conversions,
4410 -- and this is legal.
4412 if Comes_From_Source
(N
) then
4413 Check_Not_Incomplete_Type
;
4416 -- Set appropriate type
4418 Set_Etype
(N
, RTE
(RE_Tag
));
4425 when Attribute_Target_Name
=> Target_Name
: declare
4426 TN
: constant String := Sdefault
.Target_Name
.all;
4430 Check_Standard_Prefix
;
4434 if TN
(TL
) = '/' or else TN
(TL
) = '\' then
4439 Make_String_Literal
(Loc
,
4440 Strval
=> TN
(TN
'First .. TL
)));
4441 Analyze_And_Resolve
(N
, Standard_String
);
4448 when Attribute_Terminated
=>
4450 Set_Etype
(N
, Standard_Boolean
);
4457 when Attribute_To_Address
=>
4461 if Nkind
(P
) /= N_Identifier
4462 or else Chars
(P
) /= Name_System
4464 Error_Attr_P
("prefix of % attribute must be System");
4467 Generate_Reference
(RTE
(RE_Address
), P
);
4468 Analyze_And_Resolve
(E1
, Any_Integer
);
4469 Set_Etype
(N
, RTE
(RE_Address
));
4475 when Attribute_To_Any
=>
4477 Check_PolyORB_Attribute
;
4478 Set_Etype
(N
, RTE
(RE_Any
));
4484 when Attribute_Truncation
=>
4485 Check_Floating_Point_Type_1
;
4486 Resolve
(E1
, P_Base_Type
);
4487 Set_Etype
(N
, P_Base_Type
);
4493 when Attribute_Type_Class
=>
4496 Check_Not_Incomplete_Type
;
4497 Set_Etype
(N
, RTE
(RE_Type_Class
));
4503 when Attribute_TypeCode
=>
4505 Check_PolyORB_Attribute
;
4506 Set_Etype
(N
, RTE
(RE_TypeCode
));
4512 when Attribute_Type_Key
=>
4516 -- This processing belongs in Eval_Attribute ???
4519 function Type_Key
return String_Id
;
4520 -- A very preliminary implementation. For now, a signature
4521 -- consists of only the type name. This is clearly incomplete
4522 -- (e.g., adding a new field to a record type should change the
4523 -- type's Type_Key attribute).
4529 function Type_Key
return String_Id
is
4530 Full_Name
: constant String_Id
:=
4531 Fully_Qualified_Name_String
(Entity
(P
));
4534 -- Copy all characters in Full_Name but the trailing NUL
4537 for J
in 1 .. String_Length
(Full_Name
) - 1 loop
4538 Store_String_Char
(Get_String_Char
(Full_Name
, Int
(J
)));
4541 Store_String_Chars
("'Type_Key");
4546 Rewrite
(N
, Make_String_Literal
(Loc
, Type_Key
));
4549 Analyze_And_Resolve
(N
, Standard_String
);
4555 when Attribute_UET_Address
=>
4557 Check_Unit_Name
(P
);
4558 Set_Etype
(N
, RTE
(RE_Address
));
4560 -----------------------
4561 -- Unbiased_Rounding --
4562 -----------------------
4564 when Attribute_Unbiased_Rounding
=>
4565 Check_Floating_Point_Type_1
;
4566 Set_Etype
(N
, P_Base_Type
);
4567 Resolve
(E1
, P_Base_Type
);
4569 ----------------------
4570 -- Unchecked_Access --
4571 ----------------------
4573 when Attribute_Unchecked_Access
=>
4574 if Comes_From_Source
(N
) then
4575 Check_Restriction
(No_Unchecked_Access
, N
);
4578 Analyze_Access_Attribute
;
4580 -------------------------
4581 -- Unconstrained_Array --
4582 -------------------------
4584 when Attribute_Unconstrained_Array
=>
4587 Check_Not_Incomplete_Type
;
4588 Set_Etype
(N
, Standard_Boolean
);
4590 ------------------------------
4591 -- Universal_Literal_String --
4592 ------------------------------
4594 -- This is a GNAT specific attribute whose prefix must be a named
4595 -- number where the expression is either a single numeric literal,
4596 -- or a numeric literal immediately preceded by a minus sign. The
4597 -- result is equivalent to a string literal containing the text of
4598 -- the literal as it appeared in the source program with a possible
4599 -- leading minus sign.
4601 when Attribute_Universal_Literal_String
=> Universal_Literal_String
:
4605 if not Is_Entity_Name
(P
)
4606 or else Ekind
(Entity
(P
)) not in Named_Kind
4608 Error_Attr_P
("prefix for % attribute must be named number");
4615 Src
: Source_Buffer_Ptr
;
4618 Expr
:= Original_Node
(Expression
(Parent
(Entity
(P
))));
4620 if Nkind
(Expr
) = N_Op_Minus
then
4622 Expr
:= Original_Node
(Right_Opnd
(Expr
));
4627 if not Nkind_In
(Expr
, N_Integer_Literal
, N_Real_Literal
) then
4629 ("named number for % attribute must be simple literal", N
);
4632 -- Build string literal corresponding to source literal text
4637 Store_String_Char
(Get_Char_Code
('-'));
4641 Src
:= Source_Text
(Get_Source_File_Index
(S
));
4643 while Src
(S
) /= ';' and then Src
(S
) /= ' ' loop
4644 Store_String_Char
(Get_Char_Code
(Src
(S
)));
4648 -- Now we rewrite the attribute with the string literal
4651 Make_String_Literal
(Loc
, End_String
));
4655 end Universal_Literal_String
;
4657 -------------------------
4658 -- Unrestricted_Access --
4659 -------------------------
4661 -- This is a GNAT specific attribute which is like Access except that
4662 -- all scope checks and checks for aliased views are omitted.
4664 when Attribute_Unrestricted_Access
=>
4665 if Comes_From_Source
(N
) then
4666 Check_Restriction
(No_Unchecked_Access
, N
);
4669 if Is_Entity_Name
(P
) then
4670 Set_Address_Taken
(Entity
(P
));
4673 Analyze_Access_Attribute
;
4679 when Attribute_Val
=> Val
: declare
4682 Check_Discrete_Type
;
4683 Resolve
(E1
, Any_Integer
);
4684 Set_Etype
(N
, P_Base_Type
);
4686 -- Note, we need a range check in general, but we wait for the
4687 -- Resolve call to do this, since we want to let Eval_Attribute
4688 -- have a chance to find an static illegality first!
4695 when Attribute_Valid
=>
4698 -- Ignore check for object if we have a 'Valid reference generated
4699 -- by the expanded code, since in some cases valid checks can occur
4700 -- on items that are names, but are not objects (e.g. attributes).
4702 if Comes_From_Source
(N
) then
4703 Check_Object_Reference
(P
);
4706 if not Is_Scalar_Type
(P_Type
) then
4707 Error_Attr_P
("object for % attribute must be of scalar type");
4710 Set_Etype
(N
, Standard_Boolean
);
4716 when Attribute_Value
=> Value
:
4721 -- Case of enumeration type
4723 if Is_Enumeration_Type
(P_Type
) then
4724 Check_Restriction
(No_Enumeration_Maps
, N
);
4726 -- Mark all enumeration literals as referenced, since the use of
4727 -- the Value attribute can implicitly reference any of the
4728 -- literals of the enumeration base type.
4731 Ent
: Entity_Id
:= First_Literal
(P_Base_Type
);
4733 while Present
(Ent
) loop
4734 Set_Referenced
(Ent
);
4740 -- Set Etype before resolving expression because expansion of
4741 -- expression may require enclosing type. Note that the type
4742 -- returned by 'Value is the base type of the prefix type.
4744 Set_Etype
(N
, P_Base_Type
);
4745 Validate_Non_Static_Attribute_Function_Call
;
4752 when Attribute_Value_Size
=>
4755 Check_Not_Incomplete_Type
;
4756 Set_Etype
(N
, Universal_Integer
);
4762 when Attribute_Version
=>
4765 Set_Etype
(N
, RTE
(RE_Version_String
));
4771 when Attribute_Wchar_T_Size
=>
4772 Standard_Attribute
(Interfaces_Wchar_T_Size
);
4778 when Attribute_Wide_Image
=> Wide_Image
:
4781 Set_Etype
(N
, Standard_Wide_String
);
4783 Resolve
(E1
, P_Base_Type
);
4784 Validate_Non_Static_Attribute_Function_Call
;
4787 ---------------------
4788 -- Wide_Wide_Image --
4789 ---------------------
4791 when Attribute_Wide_Wide_Image
=> Wide_Wide_Image
:
4794 Set_Etype
(N
, Standard_Wide_Wide_String
);
4796 Resolve
(E1
, P_Base_Type
);
4797 Validate_Non_Static_Attribute_Function_Call
;
4798 end Wide_Wide_Image
;
4804 when Attribute_Wide_Value
=> Wide_Value
:
4809 -- Set Etype before resolving expression because expansion
4810 -- of expression may require enclosing type.
4812 Set_Etype
(N
, P_Type
);
4813 Validate_Non_Static_Attribute_Function_Call
;
4816 ---------------------
4817 -- Wide_Wide_Value --
4818 ---------------------
4820 when Attribute_Wide_Wide_Value
=> Wide_Wide_Value
:
4825 -- Set Etype before resolving expression because expansion
4826 -- of expression may require enclosing type.
4828 Set_Etype
(N
, P_Type
);
4829 Validate_Non_Static_Attribute_Function_Call
;
4830 end Wide_Wide_Value
;
4832 ---------------------
4833 -- Wide_Wide_Width --
4834 ---------------------
4836 when Attribute_Wide_Wide_Width
=>
4839 Set_Etype
(N
, Universal_Integer
);
4845 when Attribute_Wide_Width
=>
4848 Set_Etype
(N
, Universal_Integer
);
4854 when Attribute_Width
=>
4857 Set_Etype
(N
, Universal_Integer
);
4863 when Attribute_Word_Size
=>
4864 Standard_Attribute
(System_Word_Size
);
4870 when Attribute_Write
=>
4872 Check_Stream_Attribute
(TSS_Stream_Write
);
4873 Set_Etype
(N
, Standard_Void_Type
);
4874 Resolve
(N
, Standard_Void_Type
);
4878 -- All errors raise Bad_Attribute, so that we get out before any further
4879 -- damage occurs when an error is detected (for example, if we check for
4880 -- one attribute expression, and the check succeeds, we want to be able
4881 -- to proceed securely assuming that an expression is in fact present.
4883 -- Note: we set the attribute analyzed in this case to prevent any
4884 -- attempt at reanalysis which could generate spurious error msgs.
4887 when Bad_Attribute
=>
4889 Set_Etype
(N
, Any_Type
);
4891 end Analyze_Attribute
;
4893 --------------------
4894 -- Eval_Attribute --
4895 --------------------
4897 procedure Eval_Attribute
(N
: Node_Id
) is
4898 Loc
: constant Source_Ptr
:= Sloc
(N
);
4899 Aname
: constant Name_Id
:= Attribute_Name
(N
);
4900 Id
: constant Attribute_Id
:= Get_Attribute_Id
(Aname
);
4901 P
: constant Node_Id
:= Prefix
(N
);
4903 C_Type
: constant Entity_Id
:= Etype
(N
);
4904 -- The type imposed by the context
4907 -- First expression, or Empty if none
4910 -- Second expression, or Empty if none
4912 P_Entity
: Entity_Id
;
4913 -- Entity denoted by prefix
4916 -- The type of the prefix
4918 P_Base_Type
: Entity_Id
;
4919 -- The base type of the prefix type
4921 P_Root_Type
: Entity_Id
;
4922 -- The root type of the prefix type
4925 -- True if the result is Static. This is set by the general processing
4926 -- to true if the prefix is static, and all expressions are static. It
4927 -- can be reset as processing continues for particular attributes
4929 Lo_Bound
, Hi_Bound
: Node_Id
;
4930 -- Expressions for low and high bounds of type or array index referenced
4931 -- by First, Last, or Length attribute for array, set by Set_Bounds.
4934 -- Constraint error node used if we have an attribute reference has
4935 -- an argument that raises a constraint error. In this case we replace
4936 -- the attribute with a raise constraint_error node. This is important
4937 -- processing, since otherwise gigi might see an attribute which it is
4938 -- unprepared to deal with.
4940 procedure Check_Concurrent_Discriminant
(Bound
: Node_Id
);
4941 -- If Bound is a reference to a discriminant of a task or protected type
4942 -- occurring within the object's body, rewrite attribute reference into
4943 -- a reference to the corresponding discriminal. Use for the expansion
4944 -- of checks against bounds of entry family index subtypes.
4946 procedure Check_Expressions
;
4947 -- In case where the attribute is not foldable, the expressions, if
4948 -- any, of the attribute, are in a non-static context. This procedure
4949 -- performs the required additional checks.
4951 function Compile_Time_Known_Bounds
(Typ
: Entity_Id
) return Boolean;
4952 -- Determines if the given type has compile time known bounds. Note
4953 -- that we enter the case statement even in cases where the prefix
4954 -- type does NOT have known bounds, so it is important to guard any
4955 -- attempt to evaluate both bounds with a call to this function.
4957 procedure Compile_Time_Known_Attribute
(N
: Node_Id
; Val
: Uint
);
4958 -- This procedure is called when the attribute N has a non-static
4959 -- but compile time known value given by Val. It includes the
4960 -- necessary checks for out of range values.
4962 function Fore_Value
return Nat
;
4963 -- Computes the Fore value for the current attribute prefix, which is
4964 -- known to be a static fixed-point type. Used by Fore and Width.
4966 function Mantissa
return Uint
;
4967 -- Returns the Mantissa value for the prefix type
4969 procedure Set_Bounds
;
4970 -- Used for First, Last and Length attributes applied to an array or
4971 -- array subtype. Sets the variables Lo_Bound and Hi_Bound to the low
4972 -- and high bound expressions for the index referenced by the attribute
4973 -- designator (i.e. the first index if no expression is present, and
4974 -- the N'th index if the value N is present as an expression). Also
4975 -- used for First and Last of scalar types. Static is reset to False
4976 -- if the type or index type is not statically constrained.
4978 function Statically_Denotes_Entity
(N
: Node_Id
) return Boolean;
4979 -- Verify that the prefix of a potentially static array attribute
4980 -- satisfies the conditions of 4.9 (14).
4982 -----------------------------------
4983 -- Check_Concurrent_Discriminant --
4984 -----------------------------------
4986 procedure Check_Concurrent_Discriminant
(Bound
: Node_Id
) is
4988 -- The concurrent (task or protected) type
4991 if Nkind
(Bound
) = N_Identifier
4992 and then Ekind
(Entity
(Bound
)) = E_Discriminant
4993 and then Is_Concurrent_Record_Type
(Scope
(Entity
(Bound
)))
4995 Tsk
:= Corresponding_Concurrent_Type
(Scope
(Entity
(Bound
)));
4997 if In_Open_Scopes
(Tsk
) and then Has_Completion
(Tsk
) then
4999 -- Find discriminant of original concurrent type, and use
5000 -- its current discriminal, which is the renaming within
5001 -- the task/protected body.
5005 (Find_Body_Discriminal
(Entity
(Bound
)), Loc
));
5008 end Check_Concurrent_Discriminant
;
5010 -----------------------
5011 -- Check_Expressions --
5012 -----------------------
5014 procedure Check_Expressions
is
5018 while Present
(E
) loop
5019 Check_Non_Static_Context
(E
);
5022 end Check_Expressions
;
5024 ----------------------------------
5025 -- Compile_Time_Known_Attribute --
5026 ----------------------------------
5028 procedure Compile_Time_Known_Attribute
(N
: Node_Id
; Val
: Uint
) is
5029 T
: constant Entity_Id
:= Etype
(N
);
5032 Fold_Uint
(N
, Val
, False);
5034 -- Check that result is in bounds of the type if it is static
5036 if Is_In_Range
(N
, T
, Assume_Valid
=> False) then
5039 elsif Is_Out_Of_Range
(N
, T
) then
5040 Apply_Compile_Time_Constraint_Error
5041 (N
, "value not in range of}?", CE_Range_Check_Failed
);
5043 elsif not Range_Checks_Suppressed
(T
) then
5044 Enable_Range_Check
(N
);
5047 Set_Do_Range_Check
(N
, False);
5049 end Compile_Time_Known_Attribute
;
5051 -------------------------------
5052 -- Compile_Time_Known_Bounds --
5053 -------------------------------
5055 function Compile_Time_Known_Bounds
(Typ
: Entity_Id
) return Boolean is
5058 Compile_Time_Known_Value
(Type_Low_Bound
(Typ
))
5060 Compile_Time_Known_Value
(Type_High_Bound
(Typ
));
5061 end Compile_Time_Known_Bounds
;
5067 -- Note that the Fore calculation is based on the actual values
5068 -- of the bounds, and does not take into account possible rounding.
5070 function Fore_Value
return Nat
is
5071 Lo
: constant Uint
:= Expr_Value
(Type_Low_Bound
(P_Type
));
5072 Hi
: constant Uint
:= Expr_Value
(Type_High_Bound
(P_Type
));
5073 Small
: constant Ureal
:= Small_Value
(P_Type
);
5074 Lo_Real
: constant Ureal
:= Lo
* Small
;
5075 Hi_Real
: constant Ureal
:= Hi
* Small
;
5080 -- Bounds are given in terms of small units, so first compute
5081 -- proper values as reals.
5083 T
:= UR_Max
(abs Lo_Real
, abs Hi_Real
);
5086 -- Loop to compute proper value if more than one digit required
5088 while T
>= Ureal_10
loop
5100 -- Table of mantissa values accessed by function Computed using
5103 -- T'Mantissa = integer next above (D * log(10)/log(2)) + 1)
5105 -- where D is T'Digits (RM83 3.5.7)
5107 Mantissa_Value
: constant array (Nat
range 1 .. 40) of Nat
:= (
5149 function Mantissa
return Uint
is
5152 UI_From_Int
(Mantissa_Value
(UI_To_Int
(Digits_Value
(P_Type
))));
5159 procedure Set_Bounds
is
5165 -- For a string literal subtype, we have to construct the bounds.
5166 -- Valid Ada code never applies attributes to string literals, but
5167 -- it is convenient to allow the expander to generate attribute
5168 -- references of this type (e.g. First and Last applied to a string
5171 -- Note that the whole point of the E_String_Literal_Subtype is to
5172 -- avoid this construction of bounds, but the cases in which we
5173 -- have to materialize them are rare enough that we don't worry!
5175 -- The low bound is simply the low bound of the base type. The
5176 -- high bound is computed from the length of the string and this
5179 if Ekind
(P_Type
) = E_String_Literal_Subtype
then
5180 Ityp
:= Etype
(First_Index
(Base_Type
(P_Type
)));
5181 Lo_Bound
:= Type_Low_Bound
(Ityp
);
5184 Make_Integer_Literal
(Sloc
(P
),
5186 Expr_Value
(Lo_Bound
) + String_Literal_Length
(P_Type
) - 1);
5188 Set_Parent
(Hi_Bound
, P
);
5189 Analyze_And_Resolve
(Hi_Bound
, Etype
(Lo_Bound
));
5192 -- For non-array case, just get bounds of scalar type
5194 elsif Is_Scalar_Type
(P_Type
) then
5197 -- For a fixed-point type, we must freeze to get the attributes
5198 -- of the fixed-point type set now so we can reference them.
5200 if Is_Fixed_Point_Type
(P_Type
)
5201 and then not Is_Frozen
(Base_Type
(P_Type
))
5202 and then Compile_Time_Known_Value
(Type_Low_Bound
(P_Type
))
5203 and then Compile_Time_Known_Value
(Type_High_Bound
(P_Type
))
5205 Freeze_Fixed_Point_Type
(Base_Type
(P_Type
));
5208 -- For array case, get type of proper index
5214 Ndim
:= UI_To_Int
(Expr_Value
(E1
));
5217 Indx
:= First_Index
(P_Type
);
5218 for J
in 1 .. Ndim
- 1 loop
5222 -- If no index type, get out (some other error occurred, and
5223 -- we don't have enough information to complete the job!)
5231 Ityp
:= Etype
(Indx
);
5234 -- A discrete range in an index constraint is allowed to be a
5235 -- subtype indication. This is syntactically a pain, but should
5236 -- not propagate to the entity for the corresponding index subtype.
5237 -- After checking that the subtype indication is legal, the range
5238 -- of the subtype indication should be transfered to the entity.
5239 -- The attributes for the bounds should remain the simple retrievals
5240 -- that they are now.
5242 Lo_Bound
:= Type_Low_Bound
(Ityp
);
5243 Hi_Bound
:= Type_High_Bound
(Ityp
);
5245 if not Is_Static_Subtype
(Ityp
) then
5250 -------------------------------
5251 -- Statically_Denotes_Entity --
5252 -------------------------------
5254 function Statically_Denotes_Entity
(N
: Node_Id
) return Boolean is
5258 if not Is_Entity_Name
(N
) then
5265 Nkind
(Parent
(E
)) /= N_Object_Renaming_Declaration
5266 or else Statically_Denotes_Entity
(Renamed_Object
(E
));
5267 end Statically_Denotes_Entity
;
5269 -- Start of processing for Eval_Attribute
5272 -- No folding in spec expression that comes from source where the prefix
5273 -- is an unfrozen entity. This avoids premature folding in cases like:
5275 -- procedure DefExprAnal is
5276 -- type R is new Integer;
5277 -- procedure P (Arg : Integer := R'Size);
5278 -- for R'Size use 64;
5279 -- procedure P (Arg : Integer := R'Size) is
5281 -- Put_Line (Arg'Img);
5287 -- which should print 64 rather than 32. The exclusion of non-source
5288 -- constructs from this test comes from some internal usage in packed
5289 -- arrays, which otherwise fails, could use more analysis perhaps???
5291 -- We do however go ahead with generic actual types, otherwise we get
5292 -- some regressions, probably these types should be frozen anyway???
5294 if In_Spec_Expression
5295 and then Comes_From_Source
(N
)
5296 and then not (Is_Entity_Name
(P
)
5298 (Is_Frozen
(Entity
(P
))
5299 or else (Is_Type
(Entity
(P
))
5301 Is_Generic_Actual_Type
(Entity
(P
)))))
5306 -- Acquire first two expressions (at the moment, no attributes take more
5307 -- than two expressions in any case).
5309 if Present
(Expressions
(N
)) then
5310 E1
:= First
(Expressions
(N
));
5317 -- Special processing for Enabled attribute. This attribute has a very
5318 -- special prefix, and the easiest way to avoid lots of special checks
5319 -- to protect this special prefix from causing trouble is to deal with
5320 -- this attribute immediately and be done with it.
5322 if Id
= Attribute_Enabled
then
5324 -- We skip evaluation if the expander is not active. This is not just
5325 -- an optimization. It is of key importance that we not rewrite the
5326 -- attribute in a generic template, since we want to pick up the
5327 -- setting of the check in the instance, and testing expander active
5328 -- is as easy way of doing this as any.
5330 if Expander_Active
then
5332 C
: constant Check_Id
:= Get_Check_Id
(Chars
(P
));
5337 if C
in Predefined_Check_Id
then
5338 R
:= Scope_Suppress
(C
);
5340 R
:= Is_Check_Suppressed
(Empty
, C
);
5344 R
:= Is_Check_Suppressed
(Entity
(E1
), C
);
5348 Rewrite
(N
, New_Occurrence_Of
(Standard_False
, Loc
));
5350 Rewrite
(N
, New_Occurrence_Of
(Standard_True
, Loc
));
5358 -- Special processing for cases where the prefix is an object. For
5359 -- this purpose, a string literal counts as an object (attributes
5360 -- of string literals can only appear in generated code).
5362 if Is_Object_Reference
(P
) or else Nkind
(P
) = N_String_Literal
then
5364 -- For Component_Size, the prefix is an array object, and we apply
5365 -- the attribute to the type of the object. This is allowed for
5366 -- both unconstrained and constrained arrays, since the bounds
5367 -- have no influence on the value of this attribute.
5369 if Id
= Attribute_Component_Size
then
5370 P_Entity
:= Etype
(P
);
5372 -- For First and Last, the prefix is an array object, and we apply
5373 -- the attribute to the type of the array, but we need a constrained
5374 -- type for this, so we use the actual subtype if available.
5376 elsif Id
= Attribute_First
5380 Id
= Attribute_Length
5383 AS
: constant Entity_Id
:= Get_Actual_Subtype_If_Available
(P
);
5386 if Present
(AS
) and then Is_Constrained
(AS
) then
5389 -- If we have an unconstrained type we cannot fold
5397 -- For Size, give size of object if available, otherwise we
5398 -- cannot fold Size.
5400 elsif Id
= Attribute_Size
then
5401 if Is_Entity_Name
(P
)
5402 and then Known_Esize
(Entity
(P
))
5404 Compile_Time_Known_Attribute
(N
, Esize
(Entity
(P
)));
5412 -- For Alignment, give size of object if available, otherwise we
5413 -- cannot fold Alignment.
5415 elsif Id
= Attribute_Alignment
then
5416 if Is_Entity_Name
(P
)
5417 and then Known_Alignment
(Entity
(P
))
5419 Fold_Uint
(N
, Alignment
(Entity
(P
)), False);
5427 -- No other attributes for objects are folded
5434 -- Cases where P is not an object. Cannot do anything if P is
5435 -- not the name of an entity.
5437 elsif not Is_Entity_Name
(P
) then
5441 -- Otherwise get prefix entity
5444 P_Entity
:= Entity
(P
);
5447 -- At this stage P_Entity is the entity to which the attribute
5448 -- is to be applied. This is usually simply the entity of the
5449 -- prefix, except in some cases of attributes for objects, where
5450 -- as described above, we apply the attribute to the object type.
5452 -- First foldable possibility is a scalar or array type (RM 4.9(7))
5453 -- that is not generic (generic types are eliminated by RM 4.9(25)).
5454 -- Note we allow non-static non-generic types at this stage as further
5457 if Is_Type
(P_Entity
)
5458 and then (Is_Scalar_Type
(P_Entity
) or Is_Array_Type
(P_Entity
))
5459 and then (not Is_Generic_Type
(P_Entity
))
5463 -- Second foldable possibility is an array object (RM 4.9(8))
5465 elsif (Ekind
(P_Entity
) = E_Variable
5467 Ekind
(P_Entity
) = E_Constant
)
5468 and then Is_Array_Type
(Etype
(P_Entity
))
5469 and then (not Is_Generic_Type
(Etype
(P_Entity
)))
5471 P_Type
:= Etype
(P_Entity
);
5473 -- If the entity is an array constant with an unconstrained nominal
5474 -- subtype then get the type from the initial value. If the value has
5475 -- been expanded into assignments, there is no expression and the
5476 -- attribute reference remains dynamic.
5478 -- We could do better here and retrieve the type ???
5480 if Ekind
(P_Entity
) = E_Constant
5481 and then not Is_Constrained
(P_Type
)
5483 if No
(Constant_Value
(P_Entity
)) then
5486 P_Type
:= Etype
(Constant_Value
(P_Entity
));
5490 -- Definite must be folded if the prefix is not a generic type,
5491 -- that is to say if we are within an instantiation. Same processing
5492 -- applies to the GNAT attributes Has_Discriminants, Type_Class,
5493 -- Has_Tagged_Value, and Unconstrained_Array.
5495 elsif (Id
= Attribute_Definite
5497 Id
= Attribute_Has_Access_Values
5499 Id
= Attribute_Has_Discriminants
5501 Id
= Attribute_Has_Tagged_Values
5503 Id
= Attribute_Type_Class
5505 Id
= Attribute_Unconstrained_Array
5507 Id
= Attribute_Max_Alignment_For_Allocation
)
5508 and then not Is_Generic_Type
(P_Entity
)
5512 -- We can fold 'Size applied to a type if the size is known (as happens
5513 -- for a size from an attribute definition clause). At this stage, this
5514 -- can happen only for types (e.g. record types) for which the size is
5515 -- always non-static. We exclude generic types from consideration (since
5516 -- they have bogus sizes set within templates).
5518 elsif Id
= Attribute_Size
5519 and then Is_Type
(P_Entity
)
5520 and then (not Is_Generic_Type
(P_Entity
))
5521 and then Known_Static_RM_Size
(P_Entity
)
5523 Compile_Time_Known_Attribute
(N
, RM_Size
(P_Entity
));
5526 -- We can fold 'Alignment applied to a type if the alignment is known
5527 -- (as happens for an alignment from an attribute definition clause).
5528 -- At this stage, this can happen only for types (e.g. record
5529 -- types) for which the size is always non-static. We exclude
5530 -- generic types from consideration (since they have bogus
5531 -- sizes set within templates).
5533 elsif Id
= Attribute_Alignment
5534 and then Is_Type
(P_Entity
)
5535 and then (not Is_Generic_Type
(P_Entity
))
5536 and then Known_Alignment
(P_Entity
)
5538 Compile_Time_Known_Attribute
(N
, Alignment
(P_Entity
));
5541 -- If this is an access attribute that is known to fail accessibility
5542 -- check, rewrite accordingly.
5544 elsif Attribute_Name
(N
) = Name_Access
5545 and then Raises_Constraint_Error
(N
)
5548 Make_Raise_Program_Error
(Loc
,
5549 Reason
=> PE_Accessibility_Check_Failed
));
5550 Set_Etype
(N
, C_Type
);
5553 -- No other cases are foldable (they certainly aren't static, and at
5554 -- the moment we don't try to fold any cases other than these three).
5561 -- If either attribute or the prefix is Any_Type, then propagate
5562 -- Any_Type to the result and don't do anything else at all.
5564 if P_Type
= Any_Type
5565 or else (Present
(E1
) and then Etype
(E1
) = Any_Type
)
5566 or else (Present
(E2
) and then Etype
(E2
) = Any_Type
)
5568 Set_Etype
(N
, Any_Type
);
5572 -- Scalar subtype case. We have not yet enforced the static requirement
5573 -- of (RM 4.9(7)) and we don't intend to just yet, since there are cases
5574 -- of non-static attribute references (e.g. S'Digits for a non-static
5575 -- floating-point type, which we can compute at compile time).
5577 -- Note: this folding of non-static attributes is not simply a case of
5578 -- optimization. For many of the attributes affected, Gigi cannot handle
5579 -- the attribute and depends on the front end having folded them away.
5581 -- Note: although we don't require staticness at this stage, we do set
5582 -- the Static variable to record the staticness, for easy reference by
5583 -- those attributes where it matters (e.g. Succ and Pred), and also to
5584 -- be used to ensure that non-static folded things are not marked as
5585 -- being static (a check that is done right at the end).
5587 P_Root_Type
:= Root_Type
(P_Type
);
5588 P_Base_Type
:= Base_Type
(P_Type
);
5590 -- If the root type or base type is generic, then we cannot fold. This
5591 -- test is needed because subtypes of generic types are not always
5592 -- marked as being generic themselves (which seems odd???)
5594 if Is_Generic_Type
(P_Root_Type
)
5595 or else Is_Generic_Type
(P_Base_Type
)
5600 if Is_Scalar_Type
(P_Type
) then
5601 Static
:= Is_OK_Static_Subtype
(P_Type
);
5603 -- Array case. We enforce the constrained requirement of (RM 4.9(7-8))
5604 -- since we can't do anything with unconstrained arrays. In addition,
5605 -- only the First, Last and Length attributes are possibly static.
5607 -- Definite, Has_Access_Values, Has_Discriminants, Has_Tagged_Values,
5608 -- Type_Class, and Unconstrained_Array are again exceptions, because
5609 -- they apply as well to unconstrained types.
5611 -- In addition Component_Size is an exception since it is possibly
5612 -- foldable, even though it is never static, and it does apply to
5613 -- unconstrained arrays. Furthermore, it is essential to fold this
5614 -- in the packed case, since otherwise the value will be incorrect.
5616 elsif Id
= Attribute_Definite
5618 Id
= Attribute_Has_Access_Values
5620 Id
= Attribute_Has_Discriminants
5622 Id
= Attribute_Has_Tagged_Values
5624 Id
= Attribute_Type_Class
5626 Id
= Attribute_Unconstrained_Array
5628 Id
= Attribute_Component_Size
5632 elsif Id
/= Attribute_Max_Alignment_For_Allocation
then
5633 if not Is_Constrained
(P_Type
)
5634 or else (Id
/= Attribute_First
and then
5635 Id
/= Attribute_Last
and then
5636 Id
/= Attribute_Length
)
5642 -- The rules in (RM 4.9(7,8)) require a static array, but as in the
5643 -- scalar case, we hold off on enforcing staticness, since there are
5644 -- cases which we can fold at compile time even though they are not
5645 -- static (e.g. 'Length applied to a static index, even though other
5646 -- non-static indexes make the array type non-static). This is only
5647 -- an optimization, but it falls out essentially free, so why not.
5648 -- Again we compute the variable Static for easy reference later
5649 -- (note that no array attributes are static in Ada 83).
5651 -- We also need to set Static properly for subsequent legality checks
5652 -- which might otherwise accept non-static constants in contexts
5653 -- where they are not legal.
5655 Static
:= Ada_Version
>= Ada_95
5656 and then Statically_Denotes_Entity
(P
);
5662 N
:= First_Index
(P_Type
);
5664 -- The expression is static if the array type is constrained
5665 -- by given bounds, and not by an initial expression. Constant
5666 -- strings are static in any case.
5668 if Root_Type
(P_Type
) /= Standard_String
then
5670 Static
and then not Is_Constr_Subt_For_U_Nominal
(P_Type
);
5673 while Present
(N
) loop
5674 Static
:= Static
and then Is_Static_Subtype
(Etype
(N
));
5676 -- If however the index type is generic, or derived from
5677 -- one, attributes cannot be folded.
5679 if Is_Generic_Type
(Root_Type
(Etype
(N
)))
5680 and then Id
/= Attribute_Component_Size
5690 -- Check any expressions that are present. Note that these expressions,
5691 -- depending on the particular attribute type, are either part of the
5692 -- attribute designator, or they are arguments in a case where the
5693 -- attribute reference returns a function. In the latter case, the
5694 -- rule in (RM 4.9(22)) applies and in particular requires the type
5695 -- of the expressions to be scalar in order for the attribute to be
5696 -- considered to be static.
5703 while Present
(E
) loop
5705 -- If expression is not static, then the attribute reference
5706 -- result certainly cannot be static.
5708 if not Is_Static_Expression
(E
) then
5712 -- If the result is not known at compile time, or is not of
5713 -- a scalar type, then the result is definitely not static,
5714 -- so we can quit now.
5716 if not Compile_Time_Known_Value
(E
)
5717 or else not Is_Scalar_Type
(Etype
(E
))
5719 -- An odd special case, if this is a Pos attribute, this
5720 -- is where we need to apply a range check since it does
5721 -- not get done anywhere else.
5723 if Id
= Attribute_Pos
then
5724 if Is_Integer_Type
(Etype
(E
)) then
5725 Apply_Range_Check
(E
, Etype
(N
));
5732 -- If the expression raises a constraint error, then so does
5733 -- the attribute reference. We keep going in this case because
5734 -- we are still interested in whether the attribute reference
5735 -- is static even if it is not static.
5737 elsif Raises_Constraint_Error
(E
) then
5738 Set_Raises_Constraint_Error
(N
);
5744 if Raises_Constraint_Error
(Prefix
(N
)) then
5749 -- Deal with the case of a static attribute reference that raises
5750 -- constraint error. The Raises_Constraint_Error flag will already
5751 -- have been set, and the Static flag shows whether the attribute
5752 -- reference is static. In any case we certainly can't fold such an
5753 -- attribute reference.
5755 -- Note that the rewriting of the attribute node with the constraint
5756 -- error node is essential in this case, because otherwise Gigi might
5757 -- blow up on one of the attributes it never expects to see.
5759 -- The constraint_error node must have the type imposed by the context,
5760 -- to avoid spurious errors in the enclosing expression.
5762 if Raises_Constraint_Error
(N
) then
5764 Make_Raise_Constraint_Error
(Sloc
(N
),
5765 Reason
=> CE_Range_Check_Failed
);
5766 Set_Etype
(CE_Node
, Etype
(N
));
5767 Set_Raises_Constraint_Error
(CE_Node
);
5769 Rewrite
(N
, Relocate_Node
(CE_Node
));
5770 Set_Is_Static_Expression
(N
, Static
);
5774 -- At this point we have a potentially foldable attribute reference.
5775 -- If Static is set, then the attribute reference definitely obeys
5776 -- the requirements in (RM 4.9(7,8,22)), and it definitely can be
5777 -- folded. If Static is not set, then the attribute may or may not
5778 -- be foldable, and the individual attribute processing routines
5779 -- test Static as required in cases where it makes a difference.
5781 -- In the case where Static is not set, we do know that all the
5782 -- expressions present are at least known at compile time (we
5783 -- assumed above that if this was not the case, then there was
5784 -- no hope of static evaluation). However, we did not require
5785 -- that the bounds of the prefix type be compile time known,
5786 -- let alone static). That's because there are many attributes
5787 -- that can be computed at compile time on non-static subtypes,
5788 -- even though such references are not static expressions.
5796 when Attribute_Adjacent
=>
5799 (P_Root_Type
, Expr_Value_R
(E1
), Expr_Value_R
(E2
)), Static
);
5805 when Attribute_Aft
=>
5806 Fold_Uint
(N
, Aft_Value
(P_Type
), True);
5812 when Attribute_Alignment
=> Alignment_Block
: declare
5813 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
5816 -- Fold if alignment is set and not otherwise
5818 if Known_Alignment
(P_TypeA
) then
5819 Fold_Uint
(N
, Alignment
(P_TypeA
), Is_Discrete_Type
(P_TypeA
));
5821 end Alignment_Block
;
5827 -- Can only be folded in No_Ast_Handler case
5829 when Attribute_AST_Entry
=>
5830 if not Is_AST_Entry
(P_Entity
) then
5832 New_Occurrence_Of
(RTE
(RE_No_AST_Handler
), Loc
));
5841 -- Bit can never be folded
5843 when Attribute_Bit
=>
5850 -- Body_version can never be static
5852 when Attribute_Body_Version
=>
5859 when Attribute_Ceiling
=>
5861 Eval_Fat
.Ceiling
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
5863 --------------------
5864 -- Component_Size --
5865 --------------------
5867 when Attribute_Component_Size
=>
5868 if Known_Static_Component_Size
(P_Type
) then
5869 Fold_Uint
(N
, Component_Size
(P_Type
), False);
5876 when Attribute_Compose
=>
5879 (P_Root_Type
, Expr_Value_R
(E1
), Expr_Value
(E2
)),
5886 -- Constrained is never folded for now, there may be cases that
5887 -- could be handled at compile time. To be looked at later.
5889 when Attribute_Constrained
=>
5896 when Attribute_Copy_Sign
=>
5899 (P_Root_Type
, Expr_Value_R
(E1
), Expr_Value_R
(E2
)), Static
);
5905 when Attribute_Delta
=>
5906 Fold_Ureal
(N
, Delta_Value
(P_Type
), True);
5912 when Attribute_Definite
=>
5913 Rewrite
(N
, New_Occurrence_Of
(
5914 Boolean_Literals
(not Is_Indefinite_Subtype
(P_Entity
)), Loc
));
5915 Analyze_And_Resolve
(N
, Standard_Boolean
);
5921 when Attribute_Denorm
=>
5923 (N
, UI_From_Int
(Boolean'Pos (Denorm_On_Target
)), True);
5929 when Attribute_Digits
=>
5930 Fold_Uint
(N
, Digits_Value
(P_Type
), True);
5936 when Attribute_Emax
=>
5938 -- Ada 83 attribute is defined as (RM83 3.5.8)
5940 -- T'Emax = 4 * T'Mantissa
5942 Fold_Uint
(N
, 4 * Mantissa
, True);
5948 when Attribute_Enum_Rep
=>
5950 -- For an enumeration type with a non-standard representation use
5951 -- the Enumeration_Rep field of the proper constant. Note that this
5952 -- will not work for types Character/Wide_[Wide-]Character, since no
5953 -- real entities are created for the enumeration literals, but that
5954 -- does not matter since these two types do not have non-standard
5955 -- representations anyway.
5957 if Is_Enumeration_Type
(P_Type
)
5958 and then Has_Non_Standard_Rep
(P_Type
)
5960 Fold_Uint
(N
, Enumeration_Rep
(Expr_Value_E
(E1
)), Static
);
5962 -- For enumeration types with standard representations and all
5963 -- other cases (i.e. all integer and modular types), Enum_Rep
5964 -- is equivalent to Pos.
5967 Fold_Uint
(N
, Expr_Value
(E1
), Static
);
5974 when Attribute_Enum_Val
=> Enum_Val
: declare
5978 -- We have something like Enum_Type'Enum_Val (23), so search for a
5979 -- corresponding value in the list of Enum_Rep values for the type.
5981 Lit
:= First_Literal
(P_Base_Type
);
5983 if Enumeration_Rep
(Lit
) = Expr_Value
(E1
) then
5984 Fold_Uint
(N
, Enumeration_Pos
(Lit
), Static
);
5991 Apply_Compile_Time_Constraint_Error
5992 (N
, "no representation value matches",
5993 CE_Range_Check_Failed
,
5994 Warn
=> not Static
);
6004 when Attribute_Epsilon
=>
6006 -- Ada 83 attribute is defined as (RM83 3.5.8)
6008 -- T'Epsilon = 2.0**(1 - T'Mantissa)
6010 Fold_Ureal
(N
, Ureal_2
** (1 - Mantissa
), True);
6016 when Attribute_Exponent
=>
6018 Eval_Fat
.Exponent
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
6024 when Attribute_First
=> First_Attr
:
6028 if Compile_Time_Known_Value
(Lo_Bound
) then
6029 if Is_Real_Type
(P_Type
) then
6030 Fold_Ureal
(N
, Expr_Value_R
(Lo_Bound
), Static
);
6032 Fold_Uint
(N
, Expr_Value
(Lo_Bound
), Static
);
6036 Check_Concurrent_Discriminant
(Lo_Bound
);
6044 when Attribute_Fixed_Value
=>
6051 when Attribute_Floor
=>
6053 Eval_Fat
.Floor
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
6059 when Attribute_Fore
=>
6060 if Compile_Time_Known_Bounds
(P_Type
) then
6061 Fold_Uint
(N
, UI_From_Int
(Fore_Value
), Static
);
6068 when Attribute_Fraction
=>
6070 Eval_Fat
.Fraction
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
6072 -----------------------
6073 -- Has_Access_Values --
6074 -----------------------
6076 when Attribute_Has_Access_Values
=>
6077 Rewrite
(N
, New_Occurrence_Of
6078 (Boolean_Literals
(Has_Access_Values
(P_Root_Type
)), Loc
));
6079 Analyze_And_Resolve
(N
, Standard_Boolean
);
6081 -----------------------
6082 -- Has_Discriminants --
6083 -----------------------
6085 when Attribute_Has_Discriminants
=>
6086 Rewrite
(N
, New_Occurrence_Of
(
6087 Boolean_Literals
(Has_Discriminants
(P_Entity
)), Loc
));
6088 Analyze_And_Resolve
(N
, Standard_Boolean
);
6090 -----------------------
6091 -- Has_Tagged_Values --
6092 -----------------------
6094 when Attribute_Has_Tagged_Values
=>
6095 Rewrite
(N
, New_Occurrence_Of
6096 (Boolean_Literals
(Has_Tagged_Component
(P_Root_Type
)), Loc
));
6097 Analyze_And_Resolve
(N
, Standard_Boolean
);
6103 when Attribute_Identity
=>
6110 -- Image is a scalar attribute, but is never static, because it is
6111 -- not a static function (having a non-scalar argument (RM 4.9(22))
6112 -- However, we can constant-fold the image of an enumeration literal
6113 -- if names are available.
6115 when Attribute_Image
=>
6116 if Is_Entity_Name
(E1
)
6117 and then Ekind
(Entity
(E1
)) = E_Enumeration_Literal
6118 and then not Discard_Names
(First_Subtype
(Etype
(E1
)))
6119 and then not Global_Discard_Names
6122 Lit
: constant Entity_Id
:= Entity
(E1
);
6126 Get_Unqualified_Decoded_Name_String
(Chars
(Lit
));
6127 Set_Casing
(All_Upper_Case
);
6128 Store_String_Chars
(Name_Buffer
(1 .. Name_Len
));
6130 Rewrite
(N
, Make_String_Literal
(Loc
, Strval
=> Str
));
6131 Analyze_And_Resolve
(N
, Standard_String
);
6132 Set_Is_Static_Expression
(N
, False);
6140 -- Img is a scalar attribute, but is never static, because it is
6141 -- not a static function (having a non-scalar argument (RM 4.9(22))
6143 when Attribute_Img
=>
6150 -- We never try to fold Integer_Value (though perhaps we could???)
6152 when Attribute_Integer_Value
=>
6159 -- Invalid_Value is a scalar attribute that is never static, because
6160 -- the value is by design out of range.
6162 when Attribute_Invalid_Value
=>
6169 when Attribute_Large
=>
6171 -- For fixed-point, we use the identity:
6173 -- T'Large = (2.0**T'Mantissa - 1.0) * T'Small
6175 if Is_Fixed_Point_Type
(P_Type
) then
6177 Make_Op_Multiply
(Loc
,
6179 Make_Op_Subtract
(Loc
,
6183 Make_Real_Literal
(Loc
, Ureal_2
),
6185 Make_Attribute_Reference
(Loc
,
6187 Attribute_Name
=> Name_Mantissa
)),
6188 Right_Opnd
=> Make_Real_Literal
(Loc
, Ureal_1
)),
6191 Make_Real_Literal
(Loc
, Small_Value
(Entity
(P
)))));
6193 Analyze_And_Resolve
(N
, C_Type
);
6195 -- Floating-point (Ada 83 compatibility)
6198 -- Ada 83 attribute is defined as (RM83 3.5.8)
6200 -- T'Large = 2.0**T'Emax * (1.0 - 2.0**(-T'Mantissa))
6204 -- T'Emax = 4 * T'Mantissa
6207 Ureal_2
** (4 * Mantissa
) * (Ureal_1
- Ureal_2
** (-Mantissa
)),
6215 when Attribute_Last
=> Last
:
6219 if Compile_Time_Known_Value
(Hi_Bound
) then
6220 if Is_Real_Type
(P_Type
) then
6221 Fold_Ureal
(N
, Expr_Value_R
(Hi_Bound
), Static
);
6223 Fold_Uint
(N
, Expr_Value
(Hi_Bound
), Static
);
6227 Check_Concurrent_Discriminant
(Hi_Bound
);
6235 when Attribute_Leading_Part
=>
6237 Eval_Fat
.Leading_Part
6238 (P_Root_Type
, Expr_Value_R
(E1
), Expr_Value
(E2
)), Static
);
6244 when Attribute_Length
=> Length
: declare
6248 -- If any index type is a formal type, or derived from one, the
6249 -- bounds are not static. Treating them as static can produce
6250 -- spurious warnings or improper constant folding.
6252 Ind
:= First_Index
(P_Type
);
6253 while Present
(Ind
) loop
6254 if Is_Generic_Type
(Root_Type
(Etype
(Ind
))) then
6263 -- For two compile time values, we can compute length
6265 if Compile_Time_Known_Value
(Lo_Bound
)
6266 and then Compile_Time_Known_Value
(Hi_Bound
)
6269 UI_Max
(0, 1 + (Expr_Value
(Hi_Bound
) - Expr_Value
(Lo_Bound
))),
6273 -- One more case is where Hi_Bound and Lo_Bound are compile-time
6274 -- comparable, and we can figure out the difference between them.
6277 Diff
: aliased Uint
;
6281 Compile_Time_Compare
6282 (Lo_Bound
, Hi_Bound
, Diff
'Access, Assume_Valid
=> False)
6285 Fold_Uint
(N
, Uint_1
, False);
6288 Fold_Uint
(N
, Uint_0
, False);
6291 if Diff
/= No_Uint
then
6292 Fold_Uint
(N
, Diff
+ 1, False);
6305 when Attribute_Machine
=>
6308 (P_Root_Type
, Expr_Value_R
(E1
), Eval_Fat
.Round
, N
),
6315 when Attribute_Machine_Emax
=>
6316 Fold_Uint
(N
, Machine_Emax_Value
(P_Type
), Static
);
6322 when Attribute_Machine_Emin
=>
6323 Fold_Uint
(N
, Machine_Emin_Value
(P_Type
), Static
);
6325 ----------------------
6326 -- Machine_Mantissa --
6327 ----------------------
6329 when Attribute_Machine_Mantissa
=>
6330 Fold_Uint
(N
, Machine_Mantissa_Value
(P_Type
), Static
);
6332 -----------------------
6333 -- Machine_Overflows --
6334 -----------------------
6336 when Attribute_Machine_Overflows
=>
6338 -- Always true for fixed-point
6340 if Is_Fixed_Point_Type
(P_Type
) then
6341 Fold_Uint
(N
, True_Value
, True);
6343 -- Floating point case
6347 UI_From_Int
(Boolean'Pos (Machine_Overflows_On_Target
)),
6355 when Attribute_Machine_Radix
=>
6356 if Is_Fixed_Point_Type
(P_Type
) then
6357 if Is_Decimal_Fixed_Point_Type
(P_Type
)
6358 and then Machine_Radix_10
(P_Type
)
6360 Fold_Uint
(N
, Uint_10
, True);
6362 Fold_Uint
(N
, Uint_2
, True);
6365 -- All floating-point type always have radix 2
6368 Fold_Uint
(N
, Uint_2
, True);
6371 ----------------------
6372 -- Machine_Rounding --
6373 ----------------------
6375 -- Note: for the folding case, it is fine to treat Machine_Rounding
6376 -- exactly the same way as Rounding, since this is one of the allowed
6377 -- behaviors, and performance is not an issue here. It might be a bit
6378 -- better to give the same result as it would give at run time, even
6379 -- though the non-determinism is certainly permitted.
6381 when Attribute_Machine_Rounding
=>
6383 Eval_Fat
.Rounding
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
6385 --------------------
6386 -- Machine_Rounds --
6387 --------------------
6389 when Attribute_Machine_Rounds
=>
6391 -- Always False for fixed-point
6393 if Is_Fixed_Point_Type
(P_Type
) then
6394 Fold_Uint
(N
, False_Value
, True);
6396 -- Else yield proper floating-point result
6400 (N
, UI_From_Int
(Boolean'Pos (Machine_Rounds_On_Target
)), True);
6407 -- Note: Machine_Size is identical to Object_Size
6409 when Attribute_Machine_Size
=> Machine_Size
: declare
6410 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
6413 if Known_Esize
(P_TypeA
) then
6414 Fold_Uint
(N
, Esize
(P_TypeA
), True);
6422 when Attribute_Mantissa
=>
6424 -- Fixed-point mantissa
6426 if Is_Fixed_Point_Type
(P_Type
) then
6428 -- Compile time foldable case
6430 if Compile_Time_Known_Value
(Type_Low_Bound
(P_Type
))
6432 Compile_Time_Known_Value
(Type_High_Bound
(P_Type
))
6434 -- The calculation of the obsolete Ada 83 attribute Mantissa
6435 -- is annoying, because of AI00143, quoted here:
6437 -- !question 84-01-10
6439 -- Consider the model numbers for F:
6441 -- type F is delta 1.0 range -7.0 .. 8.0;
6443 -- The wording requires that F'MANTISSA be the SMALLEST
6444 -- integer number for which each bound of the specified
6445 -- range is either a model number or lies at most small
6446 -- distant from a model number. This means F'MANTISSA
6447 -- is required to be 3 since the range -7.0 .. 7.0 fits
6448 -- in 3 signed bits, and 8 is "at most" 1.0 from a model
6449 -- number, namely, 7. Is this analysis correct? Note that
6450 -- this implies the upper bound of the range is not
6451 -- represented as a model number.
6453 -- !response 84-03-17
6455 -- The analysis is correct. The upper and lower bounds for
6456 -- a fixed point type can lie outside the range of model
6467 LBound
:= Expr_Value_R
(Type_Low_Bound
(P_Type
));
6468 UBound
:= Expr_Value_R
(Type_High_Bound
(P_Type
));
6469 Bound
:= UR_Max
(UR_Abs
(LBound
), UR_Abs
(UBound
));
6470 Max_Man
:= UR_Trunc
(Bound
/ Small_Value
(P_Type
));
6472 -- If the Bound is exactly a model number, i.e. a multiple
6473 -- of Small, then we back it off by one to get the integer
6474 -- value that must be representable.
6476 if Small_Value
(P_Type
) * Max_Man
= Bound
then
6477 Max_Man
:= Max_Man
- 1;
6480 -- Now find corresponding size = Mantissa value
6483 while 2 ** Siz
< Max_Man
loop
6487 Fold_Uint
(N
, Siz
, True);
6491 -- The case of dynamic bounds cannot be evaluated at compile
6492 -- time. Instead we use a runtime routine (see Exp_Attr).
6497 -- Floating-point Mantissa
6500 Fold_Uint
(N
, Mantissa
, True);
6507 when Attribute_Max
=> Max
:
6509 if Is_Real_Type
(P_Type
) then
6511 (N
, UR_Max
(Expr_Value_R
(E1
), Expr_Value_R
(E2
)), Static
);
6513 Fold_Uint
(N
, UI_Max
(Expr_Value
(E1
), Expr_Value
(E2
)), Static
);
6517 ----------------------------------
6518 -- Max_Alignment_For_Allocation --
6519 ----------------------------------
6521 -- Max_Alignment_For_Allocation is usually the Alignment. However,
6522 -- arrays are allocated with dope, so we need to take into account both
6523 -- the alignment of the array, which comes from the component alignment,
6524 -- and the alignment of the dope. Also, if the alignment is unknown, we
6525 -- use the max (it's OK to be pessimistic).
6527 when Attribute_Max_Alignment_For_Allocation
=>
6529 A
: Uint
:= UI_From_Int
(Ttypes
.Maximum_Alignment
);
6531 if Known_Alignment
(P_Type
) and then
6532 (not Is_Array_Type
(P_Type
) or else Alignment
(P_Type
) > A
)
6534 A
:= Alignment
(P_Type
);
6537 Fold_Uint
(N
, A
, Static
);
6540 ----------------------------------
6541 -- Max_Size_In_Storage_Elements --
6542 ----------------------------------
6544 -- Max_Size_In_Storage_Elements is simply the Size rounded up to a
6545 -- Storage_Unit boundary. We can fold any cases for which the size
6546 -- is known by the front end.
6548 when Attribute_Max_Size_In_Storage_Elements
=>
6549 if Known_Esize
(P_Type
) then
6551 (Esize
(P_Type
) + System_Storage_Unit
- 1) /
6552 System_Storage_Unit
,
6556 --------------------
6557 -- Mechanism_Code --
6558 --------------------
6560 when Attribute_Mechanism_Code
=>
6564 Mech
: Mechanism_Type
;
6568 Mech
:= Mechanism
(P_Entity
);
6571 Val
:= UI_To_Int
(Expr_Value
(E1
));
6573 Formal
:= First_Formal
(P_Entity
);
6574 for J
in 1 .. Val
- 1 loop
6575 Next_Formal
(Formal
);
6577 Mech
:= Mechanism
(Formal
);
6581 Fold_Uint
(N
, UI_From_Int
(Int
(-Mech
)), True);
6589 when Attribute_Min
=> Min
:
6591 if Is_Real_Type
(P_Type
) then
6593 (N
, UR_Min
(Expr_Value_R
(E1
), Expr_Value_R
(E2
)), Static
);
6596 (N
, UI_Min
(Expr_Value
(E1
), Expr_Value
(E2
)), Static
);
6604 when Attribute_Mod
=>
6606 (N
, UI_Mod
(Expr_Value
(E1
), Modulus
(P_Base_Type
)), Static
);
6612 when Attribute_Model
=>
6614 Eval_Fat
.Model
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
6620 when Attribute_Model_Emin
=>
6621 Fold_Uint
(N
, Model_Emin_Value
(P_Base_Type
), Static
);
6627 when Attribute_Model_Epsilon
=>
6628 Fold_Ureal
(N
, Model_Epsilon_Value
(P_Base_Type
), Static
);
6630 --------------------
6631 -- Model_Mantissa --
6632 --------------------
6634 when Attribute_Model_Mantissa
=>
6635 Fold_Uint
(N
, Model_Mantissa_Value
(P_Base_Type
), Static
);
6641 when Attribute_Model_Small
=>
6642 Fold_Ureal
(N
, Model_Small_Value
(P_Base_Type
), Static
);
6648 when Attribute_Modulus
=>
6649 Fold_Uint
(N
, Modulus
(P_Type
), True);
6651 --------------------
6652 -- Null_Parameter --
6653 --------------------
6655 -- Cannot fold, we know the value sort of, but the whole point is
6656 -- that there is no way to talk about this imaginary value except
6657 -- by using the attribute, so we leave it the way it is.
6659 when Attribute_Null_Parameter
=>
6666 -- The Object_Size attribute for a type returns the Esize of the
6667 -- type and can be folded if this value is known.
6669 when Attribute_Object_Size
=> Object_Size
: declare
6670 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
6673 if Known_Esize
(P_TypeA
) then
6674 Fold_Uint
(N
, Esize
(P_TypeA
), True);
6678 -------------------------
6679 -- Passed_By_Reference --
6680 -------------------------
6682 -- Scalar types are never passed by reference
6684 when Attribute_Passed_By_Reference
=>
6685 Fold_Uint
(N
, False_Value
, True);
6691 when Attribute_Pos
=>
6692 Fold_Uint
(N
, Expr_Value
(E1
), True);
6698 when Attribute_Pred
=> Pred
:
6700 -- Floating-point case
6702 if Is_Floating_Point_Type
(P_Type
) then
6704 Eval_Fat
.Pred
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
6708 elsif Is_Fixed_Point_Type
(P_Type
) then
6710 Expr_Value_R
(E1
) - Small_Value
(P_Type
), True);
6712 -- Modular integer case (wraps)
6714 elsif Is_Modular_Integer_Type
(P_Type
) then
6715 Fold_Uint
(N
, (Expr_Value
(E1
) - 1) mod Modulus
(P_Type
), Static
);
6717 -- Other scalar cases
6720 pragma Assert
(Is_Scalar_Type
(P_Type
));
6722 if Is_Enumeration_Type
(P_Type
)
6723 and then Expr_Value
(E1
) =
6724 Expr_Value
(Type_Low_Bound
(P_Base_Type
))
6726 Apply_Compile_Time_Constraint_Error
6727 (N
, "Pred of `&''First`",
6728 CE_Overflow_Check_Failed
,
6730 Warn
=> not Static
);
6736 Fold_Uint
(N
, Expr_Value
(E1
) - 1, Static
);
6744 -- No processing required, because by this stage, Range has been
6745 -- replaced by First .. Last, so this branch can never be taken.
6747 when Attribute_Range
=>
6748 raise Program_Error
;
6754 when Attribute_Range_Length
=>
6757 -- Can fold if both bounds are compile time known
6759 if Compile_Time_Known_Value
(Hi_Bound
)
6760 and then Compile_Time_Known_Value
(Lo_Bound
)
6764 (0, Expr_Value
(Hi_Bound
) - Expr_Value
(Lo_Bound
) + 1),
6768 -- One more case is where Hi_Bound and Lo_Bound are compile-time
6769 -- comparable, and we can figure out the difference between them.
6772 Diff
: aliased Uint
;
6776 Compile_Time_Compare
6777 (Lo_Bound
, Hi_Bound
, Diff
'Access, Assume_Valid
=> False)
6780 Fold_Uint
(N
, Uint_1
, False);
6783 Fold_Uint
(N
, Uint_0
, False);
6786 if Diff
/= No_Uint
then
6787 Fold_Uint
(N
, Diff
+ 1, False);
6799 when Attribute_Ref
=>
6800 Fold_Uint
(N
, Expr_Value
(E1
), True);
6806 when Attribute_Remainder
=> Remainder
: declare
6807 X
: constant Ureal
:= Expr_Value_R
(E1
);
6808 Y
: constant Ureal
:= Expr_Value_R
(E2
);
6811 if UR_Is_Zero
(Y
) then
6812 Apply_Compile_Time_Constraint_Error
6813 (N
, "division by zero in Remainder",
6814 CE_Overflow_Check_Failed
,
6815 Warn
=> not Static
);
6821 Fold_Ureal
(N
, Eval_Fat
.Remainder
(P_Root_Type
, X
, Y
), Static
);
6828 when Attribute_Round
=> Round
:
6834 -- First we get the (exact result) in units of small
6836 Sr
:= Expr_Value_R
(E1
) / Small_Value
(C_Type
);
6838 -- Now round that exactly to an integer
6840 Si
:= UR_To_Uint
(Sr
);
6842 -- Finally the result is obtained by converting back to real
6844 Fold_Ureal
(N
, Si
* Small_Value
(C_Type
), Static
);
6851 when Attribute_Rounding
=>
6853 Eval_Fat
.Rounding
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
6859 when Attribute_Safe_Emax
=>
6860 Fold_Uint
(N
, Safe_Emax_Value
(P_Type
), Static
);
6866 when Attribute_Safe_First
=>
6867 Fold_Ureal
(N
, Safe_First_Value
(P_Type
), Static
);
6873 when Attribute_Safe_Large
=>
6874 if Is_Fixed_Point_Type
(P_Type
) then
6876 (N
, Expr_Value_R
(Type_High_Bound
(P_Base_Type
)), Static
);
6878 Fold_Ureal
(N
, Safe_Last_Value
(P_Type
), Static
);
6885 when Attribute_Safe_Last
=>
6886 Fold_Ureal
(N
, Safe_Last_Value
(P_Type
), Static
);
6892 when Attribute_Safe_Small
=>
6894 -- In Ada 95, the old Ada 83 attribute Safe_Small is redundant
6895 -- for fixed-point, since is the same as Small, but we implement
6896 -- it for backwards compatibility.
6898 if Is_Fixed_Point_Type
(P_Type
) then
6899 Fold_Ureal
(N
, Small_Value
(P_Type
), Static
);
6901 -- Ada 83 Safe_Small for floating-point cases
6904 Fold_Ureal
(N
, Model_Small_Value
(P_Type
), Static
);
6911 when Attribute_Scale
=>
6912 Fold_Uint
(N
, Scale_Value
(P_Type
), True);
6918 when Attribute_Scaling
=>
6921 (P_Root_Type
, Expr_Value_R
(E1
), Expr_Value
(E2
)), Static
);
6927 when Attribute_Signed_Zeros
=>
6929 (N
, UI_From_Int
(Boolean'Pos (Signed_Zeros_On_Target
)), Static
);
6935 -- Size attribute returns the RM size. All scalar types can be folded,
6936 -- as well as any types for which the size is known by the front end,
6937 -- including any type for which a size attribute is specified.
6939 when Attribute_Size | Attribute_VADS_Size
=> Size
: declare
6940 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
6943 if RM_Size
(P_TypeA
) /= Uint_0
then
6947 if Id
= Attribute_VADS_Size
or else Use_VADS_Size
then
6949 S
: constant Node_Id
:= Size_Clause
(P_TypeA
);
6952 -- If a size clause applies, then use the size from it.
6953 -- This is one of the rare cases where we can use the
6954 -- Size_Clause field for a subtype when Has_Size_Clause
6955 -- is False. Consider:
6957 -- type x is range 1 .. 64;
6958 -- for x'size use 12;
6959 -- subtype y is x range 0 .. 3;
6961 -- Here y has a size clause inherited from x, but normally
6962 -- it does not apply, and y'size is 2. However, y'VADS_Size
6963 -- is indeed 12 and not 2.
6966 and then Is_OK_Static_Expression
(Expression
(S
))
6968 Fold_Uint
(N
, Expr_Value
(Expression
(S
)), True);
6970 -- If no size is specified, then we simply use the object
6971 -- size in the VADS_Size case (e.g. Natural'Size is equal
6972 -- to Integer'Size, not one less).
6975 Fold_Uint
(N
, Esize
(P_TypeA
), True);
6979 -- Normal case (Size) in which case we want the RM_Size
6984 Static
and then Is_Discrete_Type
(P_TypeA
));
6993 when Attribute_Small
=>
6995 -- The floating-point case is present only for Ada 83 compatibility.
6996 -- Note that strictly this is an illegal addition, since we are
6997 -- extending an Ada 95 defined attribute, but we anticipate an
6998 -- ARG ruling that will permit this.
7000 if Is_Floating_Point_Type
(P_Type
) then
7002 -- Ada 83 attribute is defined as (RM83 3.5.8)
7004 -- T'Small = 2.0**(-T'Emax - 1)
7008 -- T'Emax = 4 * T'Mantissa
7010 Fold_Ureal
(N
, Ureal_2
** ((-(4 * Mantissa
)) - 1), Static
);
7012 -- Normal Ada 95 fixed-point case
7015 Fold_Ureal
(N
, Small_Value
(P_Type
), True);
7022 when Attribute_Stream_Size
=>
7029 when Attribute_Succ
=> Succ
:
7031 -- Floating-point case
7033 if Is_Floating_Point_Type
(P_Type
) then
7035 Eval_Fat
.Succ
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
7039 elsif Is_Fixed_Point_Type
(P_Type
) then
7041 Expr_Value_R
(E1
) + Small_Value
(P_Type
), Static
);
7043 -- Modular integer case (wraps)
7045 elsif Is_Modular_Integer_Type
(P_Type
) then
7046 Fold_Uint
(N
, (Expr_Value
(E1
) + 1) mod Modulus
(P_Type
), Static
);
7048 -- Other scalar cases
7051 pragma Assert
(Is_Scalar_Type
(P_Type
));
7053 if Is_Enumeration_Type
(P_Type
)
7054 and then Expr_Value
(E1
) =
7055 Expr_Value
(Type_High_Bound
(P_Base_Type
))
7057 Apply_Compile_Time_Constraint_Error
7058 (N
, "Succ of `&''Last`",
7059 CE_Overflow_Check_Failed
,
7061 Warn
=> not Static
);
7066 Fold_Uint
(N
, Expr_Value
(E1
) + 1, Static
);
7075 when Attribute_Truncation
=>
7077 Eval_Fat
.Truncation
(P_Root_Type
, Expr_Value_R
(E1
)), Static
);
7083 when Attribute_Type_Class
=> Type_Class
: declare
7084 Typ
: constant Entity_Id
:= Underlying_Type
(P_Base_Type
);
7088 if Is_Descendent_Of_Address
(Typ
) then
7089 Id
:= RE_Type_Class_Address
;
7091 elsif Is_Enumeration_Type
(Typ
) then
7092 Id
:= RE_Type_Class_Enumeration
;
7094 elsif Is_Integer_Type
(Typ
) then
7095 Id
:= RE_Type_Class_Integer
;
7097 elsif Is_Fixed_Point_Type
(Typ
) then
7098 Id
:= RE_Type_Class_Fixed_Point
;
7100 elsif Is_Floating_Point_Type
(Typ
) then
7101 Id
:= RE_Type_Class_Floating_Point
;
7103 elsif Is_Array_Type
(Typ
) then
7104 Id
:= RE_Type_Class_Array
;
7106 elsif Is_Record_Type
(Typ
) then
7107 Id
:= RE_Type_Class_Record
;
7109 elsif Is_Access_Type
(Typ
) then
7110 Id
:= RE_Type_Class_Access
;
7112 elsif Is_Enumeration_Type
(Typ
) then
7113 Id
:= RE_Type_Class_Enumeration
;
7115 elsif Is_Task_Type
(Typ
) then
7116 Id
:= RE_Type_Class_Task
;
7118 -- We treat protected types like task types. It would make more
7119 -- sense to have another enumeration value, but after all the
7120 -- whole point of this feature is to be exactly DEC compatible,
7121 -- and changing the type Type_Class would not meet this requirement.
7123 elsif Is_Protected_Type
(Typ
) then
7124 Id
:= RE_Type_Class_Task
;
7126 -- Not clear if there are any other possibilities, but if there
7127 -- are, then we will treat them as the address case.
7130 Id
:= RE_Type_Class_Address
;
7133 Rewrite
(N
, New_Occurrence_Of
(RTE
(Id
), Loc
));
7136 -----------------------
7137 -- Unbiased_Rounding --
7138 -----------------------
7140 when Attribute_Unbiased_Rounding
=>
7142 Eval_Fat
.Unbiased_Rounding
(P_Root_Type
, Expr_Value_R
(E1
)),
7145 -------------------------
7146 -- Unconstrained_Array --
7147 -------------------------
7149 when Attribute_Unconstrained_Array
=> Unconstrained_Array
: declare
7150 Typ
: constant Entity_Id
:= Underlying_Type
(P_Type
);
7153 Rewrite
(N
, New_Occurrence_Of
(
7155 Is_Array_Type
(P_Type
)
7156 and then not Is_Constrained
(Typ
)), Loc
));
7158 -- Analyze and resolve as boolean, note that this attribute is
7159 -- a static attribute in GNAT.
7161 Analyze_And_Resolve
(N
, Standard_Boolean
);
7163 end Unconstrained_Array
;
7169 -- Processing is shared with Size
7175 when Attribute_Val
=> Val
:
7177 if Expr_Value
(E1
) < Expr_Value
(Type_Low_Bound
(P_Base_Type
))
7179 Expr_Value
(E1
) > Expr_Value
(Type_High_Bound
(P_Base_Type
))
7181 Apply_Compile_Time_Constraint_Error
7182 (N
, "Val expression out of range",
7183 CE_Range_Check_Failed
,
7184 Warn
=> not Static
);
7190 Fold_Uint
(N
, Expr_Value
(E1
), Static
);
7198 -- The Value_Size attribute for a type returns the RM size of the
7199 -- type. This an always be folded for scalar types, and can also
7200 -- be folded for non-scalar types if the size is set.
7202 when Attribute_Value_Size
=> Value_Size
: declare
7203 P_TypeA
: constant Entity_Id
:= Underlying_Type
(P_Type
);
7205 if RM_Size
(P_TypeA
) /= Uint_0
then
7206 Fold_Uint
(N
, RM_Size
(P_TypeA
), True);
7214 -- Version can never be static
7216 when Attribute_Version
=>
7223 -- Wide_Image is a scalar attribute, but is never static, because it
7224 -- is not a static function (having a non-scalar argument (RM 4.9(22))
7226 when Attribute_Wide_Image
=>
7229 ---------------------
7230 -- Wide_Wide_Image --
7231 ---------------------
7233 -- Wide_Wide_Image is a scalar attribute but is never static, because it
7234 -- is not a static function (having a non-scalar argument (RM 4.9(22)).
7236 when Attribute_Wide_Wide_Image
=>
7239 ---------------------
7240 -- Wide_Wide_Width --
7241 ---------------------
7243 -- Processing for Wide_Wide_Width is combined with Width
7249 -- Processing for Wide_Width is combined with Width
7255 -- This processing also handles the case of Wide_[Wide_]Width
7257 when Attribute_Width |
7258 Attribute_Wide_Width |
7259 Attribute_Wide_Wide_Width
=> Width
:
7261 if Compile_Time_Known_Bounds
(P_Type
) then
7263 -- Floating-point types
7265 if Is_Floating_Point_Type
(P_Type
) then
7267 -- Width is zero for a null range (RM 3.5 (38))
7269 if Expr_Value_R
(Type_High_Bound
(P_Type
)) <
7270 Expr_Value_R
(Type_Low_Bound
(P_Type
))
7272 Fold_Uint
(N
, Uint_0
, True);
7275 -- For floating-point, we have +N.dddE+nnn where length
7276 -- of ddd is determined by type'Digits - 1, but is one
7277 -- if Digits is one (RM 3.5 (33)).
7279 -- nnn is set to 2 for Short_Float and Float (32 bit
7280 -- floats), and 3 for Long_Float and Long_Long_Float.
7281 -- For machines where Long_Long_Float is the IEEE
7282 -- extended precision type, the exponent takes 4 digits.
7286 Int
'Max (2, UI_To_Int
(Digits_Value
(P_Type
)));
7289 if Esize
(P_Type
) <= 32 then
7291 elsif Esize
(P_Type
) = 64 then
7297 Fold_Uint
(N
, UI_From_Int
(Len
), True);
7301 -- Fixed-point types
7303 elsif Is_Fixed_Point_Type
(P_Type
) then
7305 -- Width is zero for a null range (RM 3.5 (38))
7307 if Expr_Value
(Type_High_Bound
(P_Type
)) <
7308 Expr_Value
(Type_Low_Bound
(P_Type
))
7310 Fold_Uint
(N
, Uint_0
, True);
7312 -- The non-null case depends on the specific real type
7315 -- For fixed-point type width is Fore + 1 + Aft (RM 3.5(34))
7318 (N
, UI_From_Int
(Fore_Value
+ 1) + Aft_Value
(P_Type
),
7326 R
: constant Entity_Id
:= Root_Type
(P_Type
);
7327 Lo
: constant Uint
:= Expr_Value
(Type_Low_Bound
(P_Type
));
7328 Hi
: constant Uint
:= Expr_Value
(Type_High_Bound
(P_Type
));
7341 -- Width for types derived from Standard.Character
7342 -- and Standard.Wide_[Wide_]Character.
7344 elsif Is_Standard_Character_Type
(P_Type
) then
7347 -- Set W larger if needed
7349 for J
in UI_To_Int
(Lo
) .. UI_To_Int
(Hi
) loop
7351 -- All wide characters look like Hex_hhhhhhhh
7355 -- No need to compute this more than once!
7360 C
:= Character'Val (J
);
7362 -- Test for all cases where Character'Image
7363 -- yields an image that is longer than three
7364 -- characters. First the cases of Reserved_xxx
7365 -- names (length = 12).
7368 when Reserved_128 | Reserved_129 |
7369 Reserved_132 | Reserved_153
7372 when BS | HT | LF | VT | FF | CR |
7373 SO | SI | EM | FS | GS | RS |
7374 US | RI | MW | ST | PM
7377 when NUL | SOH | STX | ETX | EOT |
7378 ENQ | ACK | BEL | DLE | DC1 |
7379 DC2 | DC3 | DC4 | NAK | SYN |
7380 ETB | CAN | SUB | ESC | DEL |
7381 BPH | NBH | NEL | SSA | ESA |
7382 HTS | HTJ | VTS | PLD | PLU |
7383 SS2 | SS3 | DCS | PU1 | PU2 |
7384 STS | CCH | SPA | EPA | SOS |
7385 SCI | CSI | OSC | APC
7388 when Space
.. Tilde |
7389 No_Break_Space
.. LC_Y_Diaeresis
7391 -- Special case of soft hyphen in Ada 2005
7393 if C
= Character'Val (16#AD#
)
7394 and then Ada_Version
>= Ada_2005
7402 W
:= Int
'Max (W
, Wt
);
7406 -- Width for types derived from Standard.Boolean
7408 elsif R
= Standard_Boolean
then
7415 -- Width for integer types
7417 elsif Is_Integer_Type
(P_Type
) then
7418 T
:= UI_Max
(abs Lo
, abs Hi
);
7426 -- Only remaining possibility is user declared enum type
7429 pragma Assert
(Is_Enumeration_Type
(P_Type
));
7432 L
:= First_Literal
(P_Type
);
7434 while Present
(L
) loop
7436 -- Only pay attention to in range characters
7438 if Lo
<= Enumeration_Pos
(L
)
7439 and then Enumeration_Pos
(L
) <= Hi
7441 -- For Width case, use decoded name
7443 if Id
= Attribute_Width
then
7444 Get_Decoded_Name_String
(Chars
(L
));
7445 Wt
:= Nat
(Name_Len
);
7447 -- For Wide_[Wide_]Width, use encoded name, and
7448 -- then adjust for the encoding.
7451 Get_Name_String
(Chars
(L
));
7453 -- Character literals are always of length 3
7455 if Name_Buffer
(1) = 'Q' then
7458 -- Otherwise loop to adjust for upper/wide chars
7461 Wt
:= Nat
(Name_Len
);
7463 for J
in 1 .. Name_Len
loop
7464 if Name_Buffer
(J
) = 'U' then
7466 elsif Name_Buffer
(J
) = 'W' then
7473 W
:= Int
'Max (W
, Wt
);
7480 Fold_Uint
(N
, UI_From_Int
(W
), True);
7486 -- The following attributes denote functions that cannot be folded
7488 when Attribute_From_Any |
7490 Attribute_TypeCode
=>
7493 -- The following attributes can never be folded, and furthermore we
7494 -- should not even have entered the case statement for any of these.
7495 -- Note that in some cases, the values have already been folded as
7496 -- a result of the processing in Analyze_Attribute.
7498 when Attribute_Abort_Signal |
7501 Attribute_Address_Size |
7502 Attribute_Asm_Input |
7503 Attribute_Asm_Output |
7505 Attribute_Bit_Order |
7506 Attribute_Bit_Position |
7507 Attribute_Callable |
7510 Attribute_Code_Address |
7511 Attribute_Compiler_Version |
7513 Attribute_Default_Bit_Order |
7514 Attribute_Elaborated |
7515 Attribute_Elab_Body |
7516 Attribute_Elab_Spec |
7518 Attribute_External_Tag |
7519 Attribute_Fast_Math |
7520 Attribute_First_Bit |
7522 Attribute_Last_Bit |
7523 Attribute_Maximum_Alignment |
7526 Attribute_Partition_ID |
7527 Attribute_Pool_Address |
7528 Attribute_Position |
7529 Attribute_Priority |
7532 Attribute_Storage_Pool |
7533 Attribute_Storage_Size |
7534 Attribute_Storage_Unit |
7535 Attribute_Stub_Type |
7537 Attribute_Target_Name |
7538 Attribute_Terminated |
7539 Attribute_To_Address |
7540 Attribute_Type_Key |
7541 Attribute_UET_Address |
7542 Attribute_Unchecked_Access |
7543 Attribute_Universal_Literal_String |
7544 Attribute_Unrestricted_Access |
7547 Attribute_Wchar_T_Size |
7548 Attribute_Wide_Value |
7549 Attribute_Wide_Wide_Value |
7550 Attribute_Word_Size |
7553 raise Program_Error
;
7556 -- At the end of the case, one more check. If we did a static evaluation
7557 -- so that the result is now a literal, then set Is_Static_Expression
7558 -- in the constant only if the prefix type is a static subtype. For
7559 -- non-static subtypes, the folding is still OK, but not static.
7561 -- An exception is the GNAT attribute Constrained_Array which is
7562 -- defined to be a static attribute in all cases.
7564 if Nkind_In
(N
, N_Integer_Literal
,
7566 N_Character_Literal
,
7568 or else (Is_Entity_Name
(N
)
7569 and then Ekind
(Entity
(N
)) = E_Enumeration_Literal
)
7571 Set_Is_Static_Expression
(N
, Static
);
7573 -- If this is still an attribute reference, then it has not been folded
7574 -- and that means that its expressions are in a non-static context.
7576 elsif Nkind
(N
) = N_Attribute_Reference
then
7579 -- Note: the else case not covered here are odd cases where the
7580 -- processing has transformed the attribute into something other
7581 -- than a constant. Nothing more to do in such cases.
7588 ------------------------------
7589 -- Is_Anonymous_Tagged_Base --
7590 ------------------------------
7592 function Is_Anonymous_Tagged_Base
7599 Anon
= Current_Scope
7600 and then Is_Itype
(Anon
)
7601 and then Associated_Node_For_Itype
(Anon
) = Parent
(Typ
);
7602 end Is_Anonymous_Tagged_Base
;
7604 --------------------------------
7605 -- Name_Implies_Lvalue_Prefix --
7606 --------------------------------
7608 function Name_Implies_Lvalue_Prefix
(Nam
: Name_Id
) return Boolean is
7609 pragma Assert
(Is_Attribute_Name
(Nam
));
7611 return Attribute_Name_Implies_Lvalue_Prefix
(Get_Attribute_Id
(Nam
));
7612 end Name_Implies_Lvalue_Prefix
;
7614 -----------------------
7615 -- Resolve_Attribute --
7616 -----------------------
7618 procedure Resolve_Attribute
(N
: Node_Id
; Typ
: Entity_Id
) is
7619 Loc
: constant Source_Ptr
:= Sloc
(N
);
7620 P
: constant Node_Id
:= Prefix
(N
);
7621 Aname
: constant Name_Id
:= Attribute_Name
(N
);
7622 Attr_Id
: constant Attribute_Id
:= Get_Attribute_Id
(Aname
);
7623 Btyp
: constant Entity_Id
:= Base_Type
(Typ
);
7624 Des_Btyp
: Entity_Id
;
7625 Index
: Interp_Index
;
7627 Nom_Subt
: Entity_Id
;
7629 procedure Accessibility_Message
;
7630 -- Error, or warning within an instance, if the static accessibility
7631 -- rules of 3.10.2 are violated.
7633 ---------------------------
7634 -- Accessibility_Message --
7635 ---------------------------
7637 procedure Accessibility_Message
is
7638 Indic
: Node_Id
:= Parent
(Parent
(N
));
7641 -- In an instance, this is a runtime check, but one we
7642 -- know will fail, so generate an appropriate warning.
7644 if In_Instance_Body
then
7645 Error_Msg_F
("?non-local pointer cannot point to local object", P
);
7647 ("\?Program_Error will be raised at run time", P
);
7649 Make_Raise_Program_Error
(Loc
,
7650 Reason
=> PE_Accessibility_Check_Failed
));
7655 Error_Msg_F
("non-local pointer cannot point to local object", P
);
7657 -- Check for case where we have a missing access definition
7659 if Is_Record_Type
(Current_Scope
)
7661 Nkind_In
(Parent
(N
), N_Discriminant_Association
,
7662 N_Index_Or_Discriminant_Constraint
)
7664 Indic
:= Parent
(Parent
(N
));
7665 while Present
(Indic
)
7666 and then Nkind
(Indic
) /= N_Subtype_Indication
7668 Indic
:= Parent
(Indic
);
7671 if Present
(Indic
) then
7673 ("\use an access definition for" &
7674 " the access discriminant of&",
7675 N
, Entity
(Subtype_Mark
(Indic
)));
7679 end Accessibility_Message
;
7681 -- Start of processing for Resolve_Attribute
7684 -- If error during analysis, no point in continuing, except for array
7685 -- types, where we get better recovery by using unconstrained indexes
7686 -- than nothing at all (see Check_Array_Type).
7689 and then Attr_Id
/= Attribute_First
7690 and then Attr_Id
/= Attribute_Last
7691 and then Attr_Id
/= Attribute_Length
7692 and then Attr_Id
/= Attribute_Range
7697 -- If attribute was universal type, reset to actual type
7699 if Etype
(N
) = Universal_Integer
7700 or else Etype
(N
) = Universal_Real
7705 -- Remaining processing depends on attribute
7713 -- For access attributes, if the prefix denotes an entity, it is
7714 -- interpreted as a name, never as a call. It may be overloaded,
7715 -- in which case resolution uses the profile of the context type.
7716 -- Otherwise prefix must be resolved.
7718 when Attribute_Access
7719 | Attribute_Unchecked_Access
7720 | Attribute_Unrestricted_Access
=>
7724 if Is_Variable
(P
) then
7725 Note_Possible_Modification
(P
, Sure
=> False);
7728 -- The following comes from a query by Adam Beneschan, concerning
7729 -- improper use of universal_access in equality tests involving
7730 -- anonymous access types. Another good reason for 'Ref, but
7731 -- for now disable the test, which breaks several filed tests.
7733 if Ekind
(Typ
) = E_Anonymous_Access_Type
7734 and then Nkind_In
(Parent
(N
), N_Op_Eq
, N_Op_Ne
)
7737 Error_Msg_N
("need unique type to resolve 'Access", N
);
7738 Error_Msg_N
("\qualify attribute with some access type", N
);
7741 if Is_Entity_Name
(P
) then
7742 if Is_Overloaded
(P
) then
7743 Get_First_Interp
(P
, Index
, It
);
7744 while Present
(It
.Nam
) loop
7745 if Type_Conformant
(Designated_Type
(Typ
), It
.Nam
) then
7746 Set_Entity
(P
, It
.Nam
);
7748 -- The prefix is definitely NOT overloaded anymore at
7749 -- this point, so we reset the Is_Overloaded flag to
7750 -- avoid any confusion when reanalyzing the node.
7752 Set_Is_Overloaded
(P
, False);
7753 Set_Is_Overloaded
(N
, False);
7754 Generate_Reference
(Entity
(P
), P
);
7758 Get_Next_Interp
(Index
, It
);
7761 -- If Prefix is a subprogram name, it is frozen by this
7764 -- If it is a type, there is nothing to resolve.
7765 -- If it is an object, complete its resolution.
7767 elsif Is_Overloadable
(Entity
(P
)) then
7769 -- Avoid insertion of freeze actions in spec expression mode
7771 if not In_Spec_Expression
then
7772 Freeze_Before
(N
, Entity
(P
));
7775 elsif Is_Type
(Entity
(P
)) then
7781 Error_Msg_Name_1
:= Aname
;
7783 if not Is_Entity_Name
(P
) then
7786 elsif Is_Overloadable
(Entity
(P
))
7787 and then Is_Abstract_Subprogram
(Entity
(P
))
7789 Error_Msg_F
("prefix of % attribute cannot be abstract", P
);
7790 Set_Etype
(N
, Any_Type
);
7792 elsif Convention
(Entity
(P
)) = Convention_Intrinsic
then
7793 if Ekind
(Entity
(P
)) = E_Enumeration_Literal
then
7795 ("prefix of % attribute cannot be enumeration literal",
7799 ("prefix of % attribute cannot be intrinsic", P
);
7802 Set_Etype
(N
, Any_Type
);
7805 -- Assignments, return statements, components of aggregates,
7806 -- generic instantiations will require convention checks if
7807 -- the type is an access to subprogram. Given that there will
7808 -- also be accessibility checks on those, this is where the
7809 -- checks can eventually be centralized ???
7811 if Ekind_In
(Btyp
, E_Access_Subprogram_Type
,
7812 E_Anonymous_Access_Subprogram_Type
,
7813 E_Anonymous_Access_Protected_Subprogram_Type
)
7815 -- Deal with convention mismatch
7817 if Convention
(Btyp
) /= Convention
(Entity
(P
)) then
7819 ("subprogram & has wrong convention", P
, Entity
(P
));
7822 ("\does not match convention of access type &",
7825 if not Has_Convention_Pragma
(Btyp
) then
7827 ("\probable missing pragma Convention for &",
7832 Check_Subtype_Conformant
7833 (New_Id
=> Entity
(P
),
7834 Old_Id
=> Designated_Type
(Btyp
),
7838 if Attr_Id
= Attribute_Unchecked_Access
then
7839 Error_Msg_Name_1
:= Aname
;
7841 ("attribute% cannot be applied to a subprogram", P
);
7843 elsif Aname
= Name_Unrestricted_Access
then
7844 null; -- Nothing to check
7846 -- Check the static accessibility rule of 3.10.2(32).
7847 -- This rule also applies within the private part of an
7848 -- instantiation. This rule does not apply to anonymous
7849 -- access-to-subprogram types in access parameters.
7851 elsif Attr_Id
= Attribute_Access
7852 and then not In_Instance_Body
7854 (Ekind
(Btyp
) = E_Access_Subprogram_Type
7855 or else Is_Local_Anonymous_Access
(Btyp
))
7857 and then Subprogram_Access_Level
(Entity
(P
)) >
7858 Type_Access_Level
(Btyp
)
7861 ("subprogram must not be deeper than access type", P
);
7863 -- Check the restriction of 3.10.2(32) that disallows the
7864 -- access attribute within a generic body when the ultimate
7865 -- ancestor of the type of the attribute is declared outside
7866 -- of the generic unit and the subprogram is declared within
7867 -- that generic unit. This includes any such attribute that
7868 -- occurs within the body of a generic unit that is a child
7869 -- of the generic unit where the subprogram is declared.
7871 -- The rule also prohibits applying the attribute when the
7872 -- access type is a generic formal access type (since the
7873 -- level of the actual type is not known). This restriction
7874 -- does not apply when the attribute type is an anonymous
7875 -- access-to-subprogram type. Note that this check was
7876 -- revised by AI-229, because the originally Ada 95 rule
7877 -- was too lax. The original rule only applied when the
7878 -- subprogram was declared within the body of the generic,
7879 -- which allowed the possibility of dangling references).
7880 -- The rule was also too strict in some case, in that it
7881 -- didn't permit the access to be declared in the generic
7882 -- spec, whereas the revised rule does (as long as it's not
7885 -- There are a couple of subtleties of the test for applying
7886 -- the check that are worth noting. First, we only apply it
7887 -- when the levels of the subprogram and access type are the
7888 -- same (the case where the subprogram is statically deeper
7889 -- was applied above, and the case where the type is deeper
7890 -- is always safe). Second, we want the check to apply
7891 -- within nested generic bodies and generic child unit
7892 -- bodies, but not to apply to an attribute that appears in
7893 -- the generic unit's specification. This is done by testing
7894 -- that the attribute's innermost enclosing generic body is
7895 -- not the same as the innermost generic body enclosing the
7896 -- generic unit where the subprogram is declared (we don't
7897 -- want the check to apply when the access attribute is in
7898 -- the spec and there's some other generic body enclosing
7899 -- generic). Finally, there's no point applying the check
7900 -- when within an instance, because any violations will have
7901 -- been caught by the compilation of the generic unit.
7903 -- Note that we relax this check in CodePeer mode for
7904 -- compatibility with legacy code, since CodePeer is an
7905 -- Ada source code analyzer, not a strict compiler.
7906 -- ??? Note that a better approach would be to have a
7907 -- separate switch to relax this rule, and enable this
7908 -- switch in CodePeer mode.
7910 elsif Attr_Id
= Attribute_Access
7911 and then not CodePeer_Mode
7912 and then not In_Instance
7913 and then Present
(Enclosing_Generic_Unit
(Entity
(P
)))
7914 and then Present
(Enclosing_Generic_Body
(N
))
7915 and then Enclosing_Generic_Body
(N
) /=
7916 Enclosing_Generic_Body
7917 (Enclosing_Generic_Unit
(Entity
(P
)))
7918 and then Subprogram_Access_Level
(Entity
(P
)) =
7919 Type_Access_Level
(Btyp
)
7920 and then Ekind
(Btyp
) /=
7921 E_Anonymous_Access_Subprogram_Type
7922 and then Ekind
(Btyp
) /=
7923 E_Anonymous_Access_Protected_Subprogram_Type
7925 -- The attribute type's ultimate ancestor must be
7926 -- declared within the same generic unit as the
7927 -- subprogram is declared. The error message is
7928 -- specialized to say "ancestor" for the case where the
7929 -- access type is not its own ancestor, since saying
7930 -- simply "access type" would be very confusing.
7932 if Enclosing_Generic_Unit
(Entity
(P
)) /=
7933 Enclosing_Generic_Unit
(Root_Type
(Btyp
))
7936 ("''Access attribute not allowed in generic body",
7939 if Root_Type
(Btyp
) = Btyp
then
7942 "access type & is declared outside " &
7943 "generic unit (RM 3.10.2(32))", N
, Btyp
);
7946 ("\because ancestor of " &
7947 "access type & is declared outside " &
7948 "generic unit (RM 3.10.2(32))", N
, Btyp
);
7952 ("\move ''Access to private part, or " &
7953 "(Ada 2005) use anonymous access type instead of &",
7956 -- If the ultimate ancestor of the attribute's type is
7957 -- a formal type, then the attribute is illegal because
7958 -- the actual type might be declared at a higher level.
7959 -- The error message is specialized to say "ancestor"
7960 -- for the case where the access type is not its own
7961 -- ancestor, since saying simply "access type" would be
7964 elsif Is_Generic_Type
(Root_Type
(Btyp
)) then
7965 if Root_Type
(Btyp
) = Btyp
then
7967 ("access type must not be a generic formal type",
7971 ("ancestor access type must not be a generic " &
7978 -- If this is a renaming, an inherited operation, or a
7979 -- subprogram instance, use the original entity. This may make
7980 -- the node type-inconsistent, so this transformation can only
7981 -- be done if the node will not be reanalyzed. In particular,
7982 -- if it is within a default expression, the transformation
7983 -- must be delayed until the default subprogram is created for
7984 -- it, when the enclosing subprogram is frozen.
7986 if Is_Entity_Name
(P
)
7987 and then Is_Overloadable
(Entity
(P
))
7988 and then Present
(Alias
(Entity
(P
)))
7989 and then Expander_Active
7992 New_Occurrence_Of
(Alias
(Entity
(P
)), Sloc
(P
)));
7995 elsif Nkind
(P
) = N_Selected_Component
7996 and then Is_Overloadable
(Entity
(Selector_Name
(P
)))
7998 -- Protected operation. If operation is overloaded, must
7999 -- disambiguate. Prefix that denotes protected object itself
8000 -- is resolved with its own type.
8002 if Attr_Id
= Attribute_Unchecked_Access
then
8003 Error_Msg_Name_1
:= Aname
;
8005 ("attribute% cannot be applied to protected operation", P
);
8008 Resolve
(Prefix
(P
));
8009 Generate_Reference
(Entity
(Selector_Name
(P
)), P
);
8011 elsif Is_Overloaded
(P
) then
8013 -- Use the designated type of the context to disambiguate
8014 -- Note that this was not strictly conformant to Ada 95,
8015 -- but was the implementation adopted by most Ada 95 compilers.
8016 -- The use of the context type to resolve an Access attribute
8017 -- reference is now mandated in AI-235 for Ada 2005.
8020 Index
: Interp_Index
;
8024 Get_First_Interp
(P
, Index
, It
);
8025 while Present
(It
.Typ
) loop
8026 if Covers
(Designated_Type
(Typ
), It
.Typ
) then
8027 Resolve
(P
, It
.Typ
);
8031 Get_Next_Interp
(Index
, It
);
8038 -- X'Access is illegal if X denotes a constant and the access type
8039 -- is access-to-variable. Same for 'Unchecked_Access. The rule
8040 -- does not apply to 'Unrestricted_Access. If the reference is a
8041 -- default-initialized aggregate component for a self-referential
8042 -- type the reference is legal.
8044 if not (Ekind
(Btyp
) = E_Access_Subprogram_Type
8045 or else Ekind
(Btyp
) = E_Anonymous_Access_Subprogram_Type
8046 or else (Is_Record_Type
(Btyp
)
8048 Present
(Corresponding_Remote_Type
(Btyp
)))
8049 or else Ekind
(Btyp
) = E_Access_Protected_Subprogram_Type
8050 or else Ekind
(Btyp
)
8051 = E_Anonymous_Access_Protected_Subprogram_Type
8052 or else Is_Access_Constant
(Btyp
)
8053 or else Is_Variable
(P
)
8054 or else Attr_Id
= Attribute_Unrestricted_Access
)
8056 if Is_Entity_Name
(P
)
8057 and then Is_Type
(Entity
(P
))
8059 -- Legality of a self-reference through an access
8060 -- attribute has been verified in Analyze_Access_Attribute.
8064 elsif Comes_From_Source
(N
) then
8065 Error_Msg_F
("access-to-variable designates constant", P
);
8069 Des_Btyp
:= Designated_Type
(Btyp
);
8071 if Ada_Version
>= Ada_2005
8072 and then Is_Incomplete_Type
(Des_Btyp
)
8074 -- Ada 2005 (AI-412): If the (sub)type is a limited view of an
8075 -- imported entity, and the non-limited view is visible, make
8076 -- use of it. If it is an incomplete subtype, use the base type
8079 if From_With_Type
(Des_Btyp
)
8080 and then Present
(Non_Limited_View
(Des_Btyp
))
8082 Des_Btyp
:= Non_Limited_View
(Des_Btyp
);
8084 elsif Ekind
(Des_Btyp
) = E_Incomplete_Subtype
then
8085 Des_Btyp
:= Etype
(Des_Btyp
);
8089 if (Attr_Id
= Attribute_Access
8091 Attr_Id
= Attribute_Unchecked_Access
)
8092 and then (Ekind
(Btyp
) = E_General_Access_Type
8093 or else Ekind
(Btyp
) = E_Anonymous_Access_Type
)
8095 -- Ada 2005 (AI-230): Check the accessibility of anonymous
8096 -- access types for stand-alone objects, record and array
8097 -- components, and return objects. For a component definition
8098 -- the level is the same of the enclosing composite type.
8100 if Ada_Version
>= Ada_2005
8101 and then Is_Local_Anonymous_Access
(Btyp
)
8102 and then Object_Access_Level
(P
) > Type_Access_Level
(Btyp
)
8103 and then Attr_Id
= Attribute_Access
8105 -- In an instance, this is a runtime check, but one we
8106 -- know will fail, so generate an appropriate warning.
8108 if In_Instance_Body
then
8110 ("?non-local pointer cannot point to local object", P
);
8112 ("\?Program_Error will be raised at run time", P
);
8114 Make_Raise_Program_Error
(Loc
,
8115 Reason
=> PE_Accessibility_Check_Failed
));
8120 ("non-local pointer cannot point to local object", P
);
8124 if Is_Dependent_Component_Of_Mutable_Object
(P
) then
8126 ("illegal attribute for discriminant-dependent component",
8130 -- Check static matching rule of 3.10.2(27). Nominal subtype
8131 -- of the prefix must statically match the designated type.
8133 Nom_Subt
:= Etype
(P
);
8135 if Is_Constr_Subt_For_U_Nominal
(Nom_Subt
) then
8136 Nom_Subt
:= Base_Type
(Nom_Subt
);
8139 if Is_Tagged_Type
(Designated_Type
(Typ
)) then
8141 -- If the attribute is in the context of an access
8142 -- parameter, then the prefix is allowed to be of the
8143 -- class-wide type (by AI-127).
8145 if Ekind
(Typ
) = E_Anonymous_Access_Type
then
8146 if not Covers
(Designated_Type
(Typ
), Nom_Subt
)
8147 and then not Covers
(Nom_Subt
, Designated_Type
(Typ
))
8153 Desig
:= Designated_Type
(Typ
);
8155 if Is_Class_Wide_Type
(Desig
) then
8156 Desig
:= Etype
(Desig
);
8159 if Is_Anonymous_Tagged_Base
(Nom_Subt
, Desig
) then
8164 ("type of prefix: & not compatible",
8167 ("\with &, the expected designated type",
8168 P
, Designated_Type
(Typ
));
8173 elsif not Covers
(Designated_Type
(Typ
), Nom_Subt
)
8175 (not Is_Class_Wide_Type
(Designated_Type
(Typ
))
8176 and then Is_Class_Wide_Type
(Nom_Subt
))
8179 ("type of prefix: & is not covered", P
, Nom_Subt
);
8181 ("\by &, the expected designated type" &
8182 " (RM 3.10.2 (27))", P
, Designated_Type
(Typ
));
8185 if Is_Class_Wide_Type
(Designated_Type
(Typ
))
8186 and then Has_Discriminants
(Etype
(Designated_Type
(Typ
)))
8187 and then Is_Constrained
(Etype
(Designated_Type
(Typ
)))
8188 and then Designated_Type
(Typ
) /= Nom_Subt
8190 Apply_Discriminant_Check
8191 (N
, Etype
(Designated_Type
(Typ
)));
8194 -- Ada 2005 (AI-363): Require static matching when designated
8195 -- type has discriminants and a constrained partial view, since
8196 -- in general objects of such types are mutable, so we can't
8197 -- allow the access value to designate a constrained object
8198 -- (because access values must be assumed to designate mutable
8199 -- objects when designated type does not impose a constraint).
8201 elsif Subtypes_Statically_Match
(Des_Btyp
, Nom_Subt
) then
8204 elsif Has_Discriminants
(Designated_Type
(Typ
))
8205 and then not Is_Constrained
(Des_Btyp
)
8207 (Ada_Version
< Ada_2005
8209 not Has_Constrained_Partial_View
8210 (Designated_Type
(Base_Type
(Typ
))))
8216 ("object subtype must statically match "
8217 & "designated subtype", P
);
8219 if Is_Entity_Name
(P
)
8220 and then Is_Array_Type
(Designated_Type
(Typ
))
8223 D
: constant Node_Id
:= Declaration_Node
(Entity
(P
));
8226 Error_Msg_N
("aliased object has explicit bounds?",
8228 Error_Msg_N
("\declare without bounds"
8229 & " (and with explicit initialization)?", D
);
8230 Error_Msg_N
("\for use with unconstrained access?", D
);
8235 -- Check the static accessibility rule of 3.10.2(28).
8236 -- Note that this check is not performed for the
8237 -- case of an anonymous access type, since the access
8238 -- attribute is always legal in such a context.
8240 if Attr_Id
/= Attribute_Unchecked_Access
8241 and then Object_Access_Level
(P
) > Type_Access_Level
(Btyp
)
8242 and then Ekind
(Btyp
) = E_General_Access_Type
8244 Accessibility_Message
;
8249 if Ekind_In
(Btyp
, E_Access_Protected_Subprogram_Type
,
8250 E_Anonymous_Access_Protected_Subprogram_Type
)
8252 if Is_Entity_Name
(P
)
8253 and then not Is_Protected_Type
(Scope
(Entity
(P
)))
8255 Error_Msg_F
("context requires a protected subprogram", P
);
8257 -- Check accessibility of protected object against that of the
8258 -- access type, but only on user code, because the expander
8259 -- creates access references for handlers. If the context is an
8260 -- anonymous_access_to_protected, there are no accessibility
8261 -- checks either. Omit check entirely for Unrestricted_Access.
8263 elsif Object_Access_Level
(P
) > Type_Access_Level
(Btyp
)
8264 and then Comes_From_Source
(N
)
8265 and then Ekind
(Btyp
) = E_Access_Protected_Subprogram_Type
8266 and then Attr_Id
/= Attribute_Unrestricted_Access
8268 Accessibility_Message
;
8272 elsif Ekind_In
(Btyp
, E_Access_Subprogram_Type
,
8273 E_Anonymous_Access_Subprogram_Type
)
8274 and then Ekind
(Etype
(N
)) = E_Access_Protected_Subprogram_Type
8276 Error_Msg_F
("context requires a non-protected subprogram", P
);
8279 -- The context cannot be a pool-specific type, but this is a
8280 -- legality rule, not a resolution rule, so it must be checked
8281 -- separately, after possibly disambiguation (see AI-245).
8283 if Ekind
(Btyp
) = E_Access_Type
8284 and then Attr_Id
/= Attribute_Unrestricted_Access
8286 Wrong_Type
(N
, Typ
);
8289 -- The context may be a constrained access type (however ill-
8290 -- advised such subtypes might be) so in order to generate a
8291 -- constraint check when needed set the type of the attribute
8292 -- reference to the base type of the context.
8294 Set_Etype
(N
, Btyp
);
8296 -- Check for incorrect atomic/volatile reference (RM C.6(12))
8298 if Attr_Id
/= Attribute_Unrestricted_Access
then
8299 if Is_Atomic_Object
(P
)
8300 and then not Is_Atomic
(Designated_Type
(Typ
))
8303 ("access to atomic object cannot yield access-to-" &
8304 "non-atomic type", P
);
8306 elsif Is_Volatile_Object
(P
)
8307 and then not Is_Volatile
(Designated_Type
(Typ
))
8310 ("access to volatile object cannot yield access-to-" &
8311 "non-volatile type", P
);
8315 if Is_Entity_Name
(P
) then
8316 Set_Address_Taken
(Entity
(P
));
8318 end Access_Attribute
;
8324 -- Deal with resolving the type for Address attribute, overloading
8325 -- is not permitted here, since there is no context to resolve it.
8327 when Attribute_Address | Attribute_Code_Address
=>
8328 Address_Attribute
: begin
8330 -- To be safe, assume that if the address of a variable is taken,
8331 -- it may be modified via this address, so note modification.
8333 if Is_Variable
(P
) then
8334 Note_Possible_Modification
(P
, Sure
=> False);
8337 if Nkind
(P
) in N_Subexpr
8338 and then Is_Overloaded
(P
)
8340 Get_First_Interp
(P
, Index
, It
);
8341 Get_Next_Interp
(Index
, It
);
8343 if Present
(It
.Nam
) then
8344 Error_Msg_Name_1
:= Aname
;
8346 ("prefix of % attribute cannot be overloaded", P
);
8350 if not Is_Entity_Name
(P
)
8351 or else not Is_Overloadable
(Entity
(P
))
8353 if not Is_Task_Type
(Etype
(P
))
8354 or else Nkind
(P
) = N_Explicit_Dereference
8360 -- If this is the name of a derived subprogram, or that of a
8361 -- generic actual, the address is that of the original entity.
8363 if Is_Entity_Name
(P
)
8364 and then Is_Overloadable
(Entity
(P
))
8365 and then Present
(Alias
(Entity
(P
)))
8368 New_Occurrence_Of
(Alias
(Entity
(P
)), Sloc
(P
)));
8371 if Is_Entity_Name
(P
) then
8372 Set_Address_Taken
(Entity
(P
));
8375 if Nkind
(P
) = N_Slice
then
8377 -- Arr (X .. Y)'address is identical to Arr (X)'address,
8378 -- even if the array is packed and the slice itself is not
8379 -- addressable. Transform the prefix into an indexed component.
8381 -- Note that the transformation is safe only if we know that
8382 -- the slice is non-null. That is because a null slice can have
8383 -- an out of bounds index value.
8385 -- Right now, gigi blows up if given 'Address on a slice as a
8386 -- result of some incorrect freeze nodes generated by the front
8387 -- end, and this covers up that bug in one case, but the bug is
8388 -- likely still there in the cases not handled by this code ???
8390 -- It's not clear what 'Address *should* return for a null
8391 -- slice with out of bounds indexes, this might be worth an ARG
8394 -- One approach would be to do a length check unconditionally,
8395 -- and then do the transformation below unconditionally, but
8396 -- analyze with checks off, avoiding the problem of the out of
8397 -- bounds index. This approach would interpret the address of
8398 -- an out of bounds null slice as being the address where the
8399 -- array element would be if there was one, which is probably
8400 -- as reasonable an interpretation as any ???
8403 Loc
: constant Source_Ptr
:= Sloc
(P
);
8404 D
: constant Node_Id
:= Discrete_Range
(P
);
8408 if Is_Entity_Name
(D
)
8411 (Type_Low_Bound
(Entity
(D
)),
8412 Type_High_Bound
(Entity
(D
)))
8415 Make_Attribute_Reference
(Loc
,
8416 Prefix
=> (New_Occurrence_Of
(Entity
(D
), Loc
)),
8417 Attribute_Name
=> Name_First
);
8419 elsif Nkind
(D
) = N_Range
8420 and then Not_Null_Range
(Low_Bound
(D
), High_Bound
(D
))
8422 Lo
:= Low_Bound
(D
);
8428 if Present
(Lo
) then
8430 Make_Indexed_Component
(Loc
,
8431 Prefix
=> Relocate_Node
(Prefix
(P
)),
8432 Expressions
=> New_List
(Lo
)));
8434 Analyze_And_Resolve
(P
);
8438 end Address_Attribute
;
8444 -- Prefix of the AST_Entry attribute is an entry name which must
8445 -- not be resolved, since this is definitely not an entry call.
8447 when Attribute_AST_Entry
=>
8454 -- Prefix of Body_Version attribute can be a subprogram name which
8455 -- must not be resolved, since this is not a call.
8457 when Attribute_Body_Version
=>
8464 -- Prefix of Caller attribute is an entry name which must not
8465 -- be resolved, since this is definitely not an entry call.
8467 when Attribute_Caller
=>
8474 -- Shares processing with Address attribute
8480 -- If the prefix of the Count attribute is an entry name it must not
8481 -- be resolved, since this is definitely not an entry call. However,
8482 -- if it is an element of an entry family, the index itself may
8483 -- have to be resolved because it can be a general expression.
8485 when Attribute_Count
=>
8486 if Nkind
(P
) = N_Indexed_Component
8487 and then Is_Entity_Name
(Prefix
(P
))
8490 Indx
: constant Node_Id
:= First
(Expressions
(P
));
8491 Fam
: constant Entity_Id
:= Entity
(Prefix
(P
));
8493 Resolve
(Indx
, Entry_Index_Type
(Fam
));
8494 Apply_Range_Check
(Indx
, Entry_Index_Type
(Fam
));
8502 -- Prefix of the Elaborated attribute is a subprogram name which
8503 -- must not be resolved, since this is definitely not a call. Note
8504 -- that it is a library unit, so it cannot be overloaded here.
8506 when Attribute_Elaborated
=>
8513 -- Prefix of Enabled attribute is a check name, which must be treated
8514 -- specially and not touched by Resolve.
8516 when Attribute_Enabled
=>
8519 --------------------
8520 -- Mechanism_Code --
8521 --------------------
8523 -- Prefix of the Mechanism_Code attribute is a function name
8524 -- which must not be resolved. Should we check for overloaded ???
8526 when Attribute_Mechanism_Code
=>
8533 -- Most processing is done in sem_dist, after determining the
8534 -- context type. Node is rewritten as a conversion to a runtime call.
8536 when Attribute_Partition_ID
=>
8537 Process_Partition_Id
(N
);
8544 when Attribute_Pool_Address
=>
8551 -- We replace the Range attribute node with a range expression whose
8552 -- bounds are the 'First and 'Last attributes applied to the same
8553 -- prefix. The reason that we do this transformation here instead of
8554 -- in the expander is that it simplifies other parts of the semantic
8555 -- analysis which assume that the Range has been replaced; thus it
8556 -- must be done even when in semantic-only mode (note that the RM
8557 -- specifically mentions this equivalence, we take care that the
8558 -- prefix is only evaluated once).
8560 when Attribute_Range
=> Range_Attribute
:
8566 if not Is_Entity_Name
(P
)
8567 or else not Is_Type
(Entity
(P
))
8573 Make_Attribute_Reference
(Loc
,
8575 Duplicate_Subexpr
(P
, Name_Req
=> True),
8576 Attribute_Name
=> Name_Last
,
8577 Expressions
=> Expressions
(N
));
8580 Make_Attribute_Reference
(Loc
,
8582 Attribute_Name
=> Name_First
,
8583 Expressions
=> Expressions
(N
));
8585 -- If the original was marked as Must_Not_Freeze (see code
8586 -- in Sem_Ch3.Make_Index), then make sure the rewriting
8587 -- does not freeze either.
8589 if Must_Not_Freeze
(N
) then
8590 Set_Must_Not_Freeze
(HB
);
8591 Set_Must_Not_Freeze
(LB
);
8592 Set_Must_Not_Freeze
(Prefix
(HB
));
8593 Set_Must_Not_Freeze
(Prefix
(LB
));
8596 if Raises_Constraint_Error
(Prefix
(N
)) then
8598 -- Preserve Sloc of prefix in the new bounds, so that
8599 -- the posted warning can be removed if we are within
8600 -- unreachable code.
8602 Set_Sloc
(LB
, Sloc
(Prefix
(N
)));
8603 Set_Sloc
(HB
, Sloc
(Prefix
(N
)));
8606 Rewrite
(N
, Make_Range
(Loc
, LB
, HB
));
8607 Analyze_And_Resolve
(N
, Typ
);
8609 -- Ensure that the expanded range does not have side effects
8611 Force_Evaluation
(LB
);
8612 Force_Evaluation
(HB
);
8614 -- Normally after resolving attribute nodes, Eval_Attribute
8615 -- is called to do any possible static evaluation of the node.
8616 -- However, here since the Range attribute has just been
8617 -- transformed into a range expression it is no longer an
8618 -- attribute node and therefore the call needs to be avoided
8619 -- and is accomplished by simply returning from the procedure.
8622 end Range_Attribute
;
8628 -- We will only come here during the prescan of a spec expression
8629 -- containing a Result attribute. In that case the proper Etype has
8630 -- already been set, and nothing more needs to be done here.
8632 when Attribute_Result
=>
8639 -- Prefix must not be resolved in this case, since it is not a
8640 -- real entity reference. No action of any kind is require!
8642 when Attribute_UET_Address
=>
8645 ----------------------
8646 -- Unchecked_Access --
8647 ----------------------
8649 -- Processing is shared with Access
8651 -------------------------
8652 -- Unrestricted_Access --
8653 -------------------------
8655 -- Processing is shared with Access
8661 -- Apply range check. Note that we did not do this during the
8662 -- analysis phase, since we wanted Eval_Attribute to have a
8663 -- chance at finding an illegal out of range value.
8665 when Attribute_Val
=>
8667 -- Note that we do our own Eval_Attribute call here rather than
8668 -- use the common one, because we need to do processing after
8669 -- the call, as per above comment.
8673 -- Eval_Attribute may replace the node with a raise CE, or
8674 -- fold it to a constant. Obviously we only apply a scalar
8675 -- range check if this did not happen!
8677 if Nkind
(N
) = N_Attribute_Reference
8678 and then Attribute_Name
(N
) = Name_Val
8680 Apply_Scalar_Range_Check
(First
(Expressions
(N
)), Btyp
);
8689 -- Prefix of Version attribute can be a subprogram name which
8690 -- must not be resolved, since this is not a call.
8692 when Attribute_Version
=>
8695 ----------------------
8696 -- Other Attributes --
8697 ----------------------
8699 -- For other attributes, resolve prefix unless it is a type. If
8700 -- the attribute reference itself is a type name ('Base and 'Class)
8701 -- then this is only legal within a task or protected record.
8704 if not Is_Entity_Name
(P
)
8705 or else not Is_Type
(Entity
(P
))
8710 -- If the attribute reference itself is a type name ('Base,
8711 -- 'Class) then this is only legal within a task or protected
8712 -- record. What is this all about ???
8714 if Is_Entity_Name
(N
)
8715 and then Is_Type
(Entity
(N
))
8717 if Is_Concurrent_Type
(Entity
(N
))
8718 and then In_Open_Scopes
(Entity
(P
))
8723 ("invalid use of subtype name in expression or call", N
);
8727 -- For attributes whose argument may be a string, complete
8728 -- resolution of argument now. This avoids premature expansion
8729 -- (and the creation of transient scopes) before the attribute
8730 -- reference is resolved.
8733 when Attribute_Value
=>
8734 Resolve
(First
(Expressions
(N
)), Standard_String
);
8736 when Attribute_Wide_Value
=>
8737 Resolve
(First
(Expressions
(N
)), Standard_Wide_String
);
8739 when Attribute_Wide_Wide_Value
=>
8740 Resolve
(First
(Expressions
(N
)), Standard_Wide_Wide_String
);
8742 when others => null;
8745 -- If the prefix of the attribute is a class-wide type then it
8746 -- will be expanded into a dispatching call to a predefined
8747 -- primitive. Therefore we must check for potential violation
8748 -- of such restriction.
8750 if Is_Class_Wide_Type
(Etype
(P
)) then
8751 Check_Restriction
(No_Dispatching_Calls
, N
);
8755 -- Normally the Freezing is done by Resolve but sometimes the Prefix
8756 -- is not resolved, in which case the freezing must be done now.
8758 Freeze_Expression
(P
);
8760 -- Finally perform static evaluation on the attribute reference
8763 end Resolve_Attribute
;
8765 --------------------------------
8766 -- Stream_Attribute_Available --
8767 --------------------------------
8769 function Stream_Attribute_Available
8771 Nam
: TSS_Name_Type
;
8772 Partial_View
: Node_Id
:= Empty
) return Boolean
8774 Etyp
: Entity_Id
:= Typ
;
8776 -- Start of processing for Stream_Attribute_Available
8779 -- We need some comments in this body ???
8781 if Has_Stream_Attribute_Definition
(Typ
, Nam
) then
8785 if Is_Class_Wide_Type
(Typ
) then
8786 return not Is_Limited_Type
(Typ
)
8787 or else Stream_Attribute_Available
(Etype
(Typ
), Nam
);
8790 if Nam
= TSS_Stream_Input
8791 and then Is_Abstract_Type
(Typ
)
8792 and then not Is_Class_Wide_Type
(Typ
)
8797 if not (Is_Limited_Type
(Typ
)
8798 or else (Present
(Partial_View
)
8799 and then Is_Limited_Type
(Partial_View
)))
8804 -- In Ada 2005, Input can invoke Read, and Output can invoke Write
8806 if Nam
= TSS_Stream_Input
8807 and then Ada_Version
>= Ada_2005
8808 and then Stream_Attribute_Available
(Etyp
, TSS_Stream_Read
)
8812 elsif Nam
= TSS_Stream_Output
8813 and then Ada_Version
>= Ada_2005
8814 and then Stream_Attribute_Available
(Etyp
, TSS_Stream_Write
)
8819 -- Case of Read and Write: check for attribute definition clause that
8820 -- applies to an ancestor type.
8822 while Etype
(Etyp
) /= Etyp
loop
8823 Etyp
:= Etype
(Etyp
);
8825 if Has_Stream_Attribute_Definition
(Etyp
, Nam
) then
8830 if Ada_Version
< Ada_2005
then
8832 -- In Ada 95 mode, also consider a non-visible definition
8835 Btyp
: constant Entity_Id
:= Implementation_Base_Type
(Typ
);
8838 and then Stream_Attribute_Available
8839 (Btyp
, Nam
, Partial_View
=> Typ
);
8844 end Stream_Attribute_Available
;